JP2015188943A - Torque limiter in constant torque electric screwdriver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque limiter in a constant torque electric screwdriver, as a torque limiter used for a constant torque electric screwdriver, which can easily and simply regulate or adjust a set torque (hysteresis torque) of a torque limiter in a required screw fastening work without disassembling the torque limiter.SOLUTION: A torque limiter comprising a drive-side rotor 10 and a driven-side rotor 20 and provided with cylindrical permanent magnets mutually magnetically coupled with the rotors, respectively, and a magnetic substance 24 disposed oppositely in the outer periphery is configured by detachably providing a cover member 26 made of a magnetic material so as to partially enclose the outer periphery of the magnetic substance.

Description

  The present invention relates to a constant torque electric screwdriver configured to transmit a drive of an electric motor or the like to a tool via a torque limiter and perform a screw tightening operation or the like. The present invention relates to a torque limiter in a constant torque electric screwdriver or the like that is configured such that the magnetic coupling portion of the torque limiter slips when it acts on, and the drive side is idled.

  By applying a torque limiter that can set the tightening torque or loosening torque of the screw tool with high accuracy, the applicant of the present application can assemble particularly small precision parts and connect weak parts such as plastic products. A torque-fixed screwdriver that can be easily and safely tightened or removed with a small screw with a low torque suitable for assembly has been proposed (see Patent Document 1).

  The torque fixed type driver described in Patent Document 1 houses a drive shaft rotatably inside an outer case, and a coil spring is tightly fitted on the outer periphery of the drive shaft, and is provided at both ends of the coil spring. The drive shaft is provided with a torque limiter that engages the outer case or a member fixed to the outer case, and the case serves as a gripping part casing, or the outer case is surrounded and fixed by the gripping part casing. It is composed of a configuration in which a driver bit is provided at the tip.

  Further, in the torque fixed type driver described in Patent Document 1, instead of the friction type torque limiter using the coil spring, a torque type limiter using a magnetic system using a permanent magnet is adopted, and the same as described above. A torque fixed type driver is also proposed. In this case, the torque limiter can be configured as a non-contact type, and a torque-fixed type driver that can perform more shockless torque setting can be obtained.

  In the case of the electric motor drive type torque fixed type driver, the drive output shaft of the electric motor can be detachably coupled to the closed rear end of the outer case or the gripping part casing so as to be rotationally driven. A first outer casing that surrounds and supports the electric motor and a second outer casing that surrounds the torque-fixed driver and rotatably supports the drive output shaft thereof can be attached to and detached from each other. Consists of connected configurations.

  The torque fixed type driver proposed in Patent Document 1 described above uses a torque limiter to set a required tightening torque that is set in advance when assembling small precision parts and connecting and assembling weak parts such as plastic products. The screw tool can be tightened properly and accurately as a manual screwdriver and an electric screwdriver.

  However, in the electric torque fixed type driver according to the above proposal, when the tightening torque becomes a set constant torque value in the screw tightening operation, the torque limiter rotates idly on the drive shaft side directly connected to the drive output shaft of the electric motor. However, the drive of the electric motor is continued as it is. Therefore, in this case, power consumption due to driving of the electric motor is not only wasted, but also time is wasted for shifting to the continuous screw tightening work, and the production efficiency in the assembling work of various parts is reduced. There is also a drawback that affects the reduction of manufacturing cost.

  Therefore, in order to solve the above-mentioned problems, the present inventor has connected the drive shaft side of the torque limiter to the output shaft of the electric motor, and the transmission rotation portion side of the torque limiter is used as a bit holder shaft for connecting the driver bit. In combination, the transmission rotation portion of the torque limiter and the bit holder shaft are rotatably held in the gripper casing, and a sensor sensing member such as a magnet is provided on a part of the outer periphery of the transmission rotation portion of the torque limiter, A sensor such as a Hall element is provided on the inner side surface of the gripper casing in correspondence with the sensor sensing member, and the rotational state of the transmission rotating portion of the torque limiter is monitored by the sensor using an intermittent detection signal from the sensor sensing member. Then, the rotation stop state of the transmission rotating part due to the operation of the torque limiter is determined by the presence or absence of the detection signal, Proposes a constant torque electric screwdriver that can realize a constant torque electric screwdriver that can immediately stop the driving of the electric motor based on this detection signal when detecting the rotation stop of the transmission rotating portion of the torque limiter (See Patent Document 2).

  In the constant torque electric screwdriver described in Patent Document 2, when the tightening torque reaches a set constant torque value in the screw tightening operation, the torque limiter idles on the drive shaft side directly connected to the drive output shaft of the electric motor. This state can be immediately detected by the sensor, and the driving of the electric motor can be stopped quickly. Therefore, the power consumption by driving the electric motor is properly performed, and the transition to the continuous screw tightening operation can be achieved quickly and smoothly. In addition, the production efficiency and the manufacturing cost in the assembling work of various parts are increased. It can contribute to the reduction of.

  Today, various electronic devices, medical devices, and other precision devices require the assembly of extremely small or minute precision parts, and screws that are tightened with precision screws with extremely small dimensions when assembling them. Tightening is essential. Therefore, the use of this type of constant torque electric screwdriver is optimal for such screw tightening operations.

  Therefore, when using this type of constant-torque electric screwdriver for screw tightening work with the precision screw as described above, the performance of the torque limiter may be deteriorated depending on the frequency of use, or the object to be tightened may be In the case of being fragile, it is required that the screw tightening torque value (hysteresis torque) preset in the torque limiter can be adjusted or adjusted as appropriate. However, in the conventional constant torque electric screwdriver, it is difficult to adjust or adjust the screw tightening torque value (hysteresis torque) set in the torque limiter at the work site.

  Conventionally, when assembling the torque limiter, as a technique for adjusting the set torque value (hysteresis torque), an inner magnet coupled to the internal rotational shaft of the torque limiter and an outer coupled to the external rotational shaft opposed thereto are used. A torque limiter configured to adjust a hysteresis torque (set torque value) as a torque limiter by variably setting a facing area between the inner magnet and the outer magnet in relation to a magnet, and a manufacturing method thereof It has been proposed (see Patent Document 3).

  That is, the torque limiter described in Patent Document 3 includes a first rotating shaft provided with a cylindrical permanent magnet (or semi-hard magnetic body) on the outer peripheral surface and a cylindrical semi-hard magnetic body (or on the inner peripheral surface). A second rotating shaft provided with a permanent magnet), and the first rotating shaft and the second rotating shaft so that the permanent magnet (or semi-hard magnetic body) and the semi-hard magnetic body (or permanent magnet) face each other. A torque limiter which arranges a rotating shaft and is integrated so as to be relatively rotatable, and transmits torque between the first rotating shaft and the second rotating shaft by a hysteresis torque acting between the permanent magnet and the semi-hard magnetic body. The position of the permanent magnet (or semi-hard magnetic body) on the outer peripheral surface of the first rotating shaft can be changed without changing the arrangement of the first rotating shaft and the second rotating shaft, or Change the arrangement of the first rotation axis and the second rotation axis Without changing the position of the semi-rigid magnetic body (or permanent magnet) on the inner peripheral surface of the second rotating shaft, or both of them can be changed, and the permanent magnet can be changed by changing the position. And the opposing area of the semi-hard magnetic material is changed, and the hysteresis torque can be adjusted.

JP-A-11-285985 JP 2008-183643 A JP-A-8-308209

  However, the invention described in Patent Document 3 relates to a torque limiter used in a paper feeding device and the like and a method for manufacturing the torque limiter, and can easily adjust the torque without changing the overall length of the structure, and has a simple structure. It is configured so that the productivity is good and the cost can be reduced. That is, the torque limiter described in Patent Document 3 configured as described above is intended for convenience in manufacturing the torque limiter.

  Therefore, when the torque limiter configured as described above is applied as, for example, the torque limiter of the constant torque electric screwdriver described above, the torque limiter incorporated in the electric screwdriver can easily and easily set torque, that is, hysteresis torque in the screw tightening operation. Is difficult to adjust. That is, when the torque limiter incorporated in the electric screwdriver needs to be adjusted with respect to the set torque (hysteresis torque) of the torque limiter due to, for example, a change in the object to be screwed, the torque limiter is removed from the electric screwdriver, Furthermore, it is necessary to disassemble the torque limiter.

  From such a point of view, the present inventor can easily and tolerably set the torque limiter torque value without performing a complicated work such as removing the torque limiter incorporated in the constant torque electric screwdriver from the electric screwdriver body and disassembling it. As a result of earnest study and trial production of means capable of adjusting (adjusting the hysteresis torque), the basic structure of the torque limiter is not changed at all, and the magnetic force is applied to the outer periphery of the torque limiter. It has been found that a preset set torque value (hysteresis torque) of a torque limiter can be variably adjusted easily and simply by detachably attaching a cover member made of material.

  That is, in the present invention, a driving-side rotating body and a driven-side rotating body are provided, and a cylindrical permanent magnet magnetically coupled to each of the rotating bodies and a magnetic body disposed opposite to the outer periphery thereof are provided. In this torque limiter, the permanent member that is magnetically coupled to each other by detachably providing a cover member made of a magnetic material so as to partially surround the outer periphery of the magnetic body. By changing the hysteresis torque between the magnet and the magnetic material facing the magnet, it is possible to variably adjust the preset torque value (hysteresis torque) of a preset torque limiter.

  In this case, the torque limiter is provided with a cylindrical permanent magnet on the outer peripheral surface of the cylindrical permanent magnet holding member having the drive shaft coupling portion, and communicates with the drive shaft coupling portion at one end of the permanent magnet holding member. A drive-side rotating body that is coupled in such a manner, and a cylindrical magnetic body that is disposed coaxially with the permanent magnet holding member and that is coupled to one end of the magnetic body. It can comprise from the driven side rotary body which has a driven shaft coupling | bond part. And the magnetic material formed in the cylindrical shape which has a cut | interruption in a longitudinal direction and has spring elasticity so that the outer periphery can be partially enclosed with respect to the outer peripheral part of the said cylindrical magnetic body of the said torque limiter By providing a cover member made of the above, it is possible to change the hysteresis torque between the permanent magnets magnetically coupled to each other and the magnetic material facing the permanent magnets.

  In this case, since the hysteresis torque of the torque limiter set in advance can be reduced in accordance with the area of the cover member that surrounds the outer peripheral portion of the magnetic body, the cover member has the magnetic body The adjustment of the hysteresis torque can be changed by providing a plurality of cover members appropriately changing the area surrounding the outer periphery of each of them and selectively using them.

  When the torque limiter configured as described above is used in a constant torque electric screwdriver, for example, the driving output of the electric motor is coupled to the driving shaft coupling portion of the driving side rotating body. In addition, a magnet as a pair of sensor sensing members is embedded symmetrically in the circumferential direction at equal intervals in the drive side rotator, and a tool is attached to the driven shaft coupling portion with respect to the driven side rotator. A constant torque electric screwdriver can be assembled by setting so that the driver bit is coupled.

  Further, this type of torque limiter is not limited to the constant torque electric driver described above, but can be used as a torque limiter in hand-held tools such as a driver driven manually or by other power. The tool is not limited to the driver bit, and various tools such as a screw tap and a drill for performing tapping can be used.

  Accordingly, an object of the present invention is to easily and easily adjust the torque limiter setting torque (hysteresis torque) in a required screw tightening operation as a torque limiter used for a constant torque electric screwdriver or the like without disassembling the torque limiter. Another object of the present invention is to provide a torque limiter in a constant torque electric screwdriver that can be adjusted.

  In order to achieve the above object, a torque limiter in a constant torque electric screwdriver or the like according to claim 1 of the present invention includes a driving side rotating body and a driven side rotating body, and is magnetically coupled to the rotating body. In a torque limiter comprising a cylindrical permanent magnet and a magnetic body disposed opposite to the outer periphery of the magnet, the outer periphery of the magnetic body is made of a magnetic material so as to partially surround the outer periphery. The cover member to be provided is detachably provided.

  A torque limiter in a constant torque electric screwdriver or the like according to claim 2 of the present invention is provided with a cylindrical permanent magnet on the outer peripheral surface of a cylindrical permanent magnet holding member having a drive shaft coupling portion and the permanent magnet holding member. A drive-side rotating body that is coupled to one end portion so as to communicate with the drive shaft coupling portion, and a cylindrical magnetic body that is disposed coaxially with the permanent magnet holding member and is arranged around the permanent magnet. And a driven-side rotating body that has a driven shaft coupling portion that is disposed so as to be coupled to each other and that is coupled to one end portion of the magnetic body, and has an outer circumference relative to the outer circumferential portion of the cylindrical magnetic body. A cover member made of a magnetic material formed in a cylindrical shape having a cut in the longitudinal direction and having spring elasticity is provided so as to be detachable.

  In the torque limiter in the constant torque electric screwdriver or the like according to claim 3 of the present invention, the cover member is provided with a plurality of cover members appropriately changing the area surrounding the outer peripheral portion of the magnetic body, and each is used selectively. It is configured as described above.

  A torque limiter in a constant torque electric screwdriver or the like according to claim 4 of the present invention is set so that a drive output shaft such as an electric motor is coupled to the drive shaft coupling portion of the drive side rotating body, and A magnet as a pair of sensor sensing members is symmetrically embedded in the drive side rotator at equal intervals in the circumferential direction, and required tools are provided at the driven shaft coupling portion with respect to the driven side rotator. It is set to be combined.

  The torque limiter in the constant torque electric screwdriver or the like according to claim 5 of the present invention is configured such that the drive output shaft and the driver bit of the electric motor can be attached to and detached from the drive shaft coupling portion and the driven shaft coupling portion of the torque limiter, respectively. It is coupled and accommodated in the gripper casing of the electric screwdriver so as to be freely rotatable, and a sensor comprising a hall element is disposed in the gripper casing corresponding to the sensor sensing member provided in the torque limiter, In the screw tightening operation, a state in which the driving side rotating body of the torque limiter idles and the driven side rotating body stops rotating is detected by the sensor, and the driving stop control of the electric motor is performed and detected by the sensor. When the torque limiter is activated, the load current or load voltage of the electric motor is detected. And a constant torque electric driver provided with a control device for generating a required alarm when the load current value or the load voltage value changes by a predetermined value compared with the initial value. To do.

  According to the torque limiter in the constant torque electric screwdriver or the like according to claim 1 of the present invention, by attaching and detaching the cover member made of a magnetic material to the magnetic body formed on the cylindrical outer peripheral portion of the torque limiter, The preset torque value (hysteresis torque) of the torque limiter set in advance can be adjusted variably easily and simply.

  According to a torque limiter in a constant torque electric screwdriver or the like according to claim 2 of the present invention, the cover member made of the magnetic material is formed into a cylindrical shape having a cut in the longitudinal direction and having spring elasticity. It is possible to variably adjust a preset torque value (hysteresis torque) of a torque limiter which is configured and configured in an easy and simple operation.

  According to the torque limiter of the constant torque electric screwdriver or the like according to claim 3 of the present invention, the adjustment of the set torque value (hysteresis torque) of the torque limiter can be variably set by the selective use of the cover member made of a magnetic material. it can.

  According to the torque limiter in the constant torque electric driver or the like according to claim 4 of the present invention, the electric motor and other drive output shafts are coupled to the driving side rotating body, and various tools are connected to the driven side rotating body. By combining the types, the torque limiter setting torque value (hysteresis torque) can be adjusted simply and easily and appropriately as required for the required screw tightening and other operations. .

  According to the torque limiter of the constant torque electric screwdriver or the like according to claim 5 of the present invention, the torque limiter setting torque value (hysteresis torque) can be obtained for a required screw tightening operation, particularly by configuring as a constant torque electric screwdriver. ) Can be easily and appropriately performed as needed.

1 shows an embodiment of a torque limiter according to the present invention, where (a) is an external perspective view seen from above, and (b) is an external perspective view seen from below. It is a longitudinal cross-sectional view which shows the internal structure of the torque limiter which concerns on this invention. It is a schematic structure explanatory drawing which shows the state which comprises the torque limiter which concerns on this invention as a constant torque electric driver. It is explanatory drawing which shows the structure of the constant torque electric screwdriver incorporating the torque limiter which concerns on this invention.

  Next, an embodiment of a torque limiter in a constant torque electric screwdriver or the like according to the present invention will be described in detail with reference to the accompanying drawings.

  FIGS. 1 and 2 show a typical embodiment of the torque limiter TL according to the present invention. FIGS. 1A and 1B are perspective views showing the appearance of the torque limiter TL. FIG. 2 is a longitudinal sectional view showing the internal structure of the torque limiter TL shown in FIG.

  1 and 2, the torque limiter TL of the present embodiment includes a driving side rotating body 10 and a driven side rotating body 20. The drive-side rotating body 10 is provided with a cylindrical permanent magnet 16 on the outer peripheral surface of a cylindrical permanent magnet holding member 14 having a drive shaft coupling portion 12 and at one end of the permanent magnet holding member 14 the drive. The shaft coupling portion 12 is configured to be coupled so as to communicate with each other. The driven-side rotating body 20 has a driven shaft coupling portion 22, is disposed coaxially with the permanent magnet holding member 12, and magnetically couples a cylindrical magnetic body 24 to the outer periphery of the permanent magnet 16. In this way, it is configured to be opposed to each other and coupled to one end of the magnetic body 24.

  In the torque limiter TL of the present embodiment configured as described above, the permanent magnet 16 rotates integrally via the permanent magnet holding member 14 by the rotational drive of the drive side rotating body 10. When rotating the drive-side rotator 10 in such a manner, the magnetic bodies 24 arranged so as to be magnetically coupled to the permanent magnets 16 are in a coupling relationship based on a hysteresis torque value set in advance. The driven rotary body 20 is rotationally driven integrally with the permanent magnet 16 via the magnetic body 24. Such a configuration is basically the same as that of a conventional torque limiter.

  Therefore, in the present invention, the outer peripheral portion of the cylindrical magnetic body 24 in the driven-side rotating body 20 has cuts 26a and 26b in the longitudinal direction so that the outer periphery can be partially surrounded. In addition, the cover member 26 made of a magnetic material formed in a cylindrical shape having spring elasticity is detachably provided.

  In this case, the outer periphery of the cylindrical magnetic body 24 in the driven-side rotating body 20 of the torque limiter TL has cuts 26a and 26b in the longitudinal direction so that the outer periphery can be partially surrounded. By providing the cover member 26 made of a magnetic material formed in a cylindrical shape having spring elasticity, the hysteresis torque between the permanent magnet 14 in the driving side rotating body 10 and the magnetic body 24 facing the permanent magnet 14 can be changed. it can.

  In this case, the cover member 26 of the torque limiter TL is provided with a plurality of cover members 26 that appropriately change the area surrounding the outer peripheral portion of the magnetic body 24, and each of the cover members 26 is selectively used. Adjustment of the set torque value (hysteresis torque) of TL can be set variably.

  Therefore, the torque limiter TL according to the present invention having the above-described configuration has an excellent function and effect that the preset hysteresis torque value can be easily and easily adjusted without disassembling the configuration. Can be obtained.

  Next, an example in which the torque limiter TL of the present embodiment having the above-described configuration is applied to a constant torque electric driver will be described.

  FIG. 3 is an explanatory diagram of a schematic configuration when the torque limiter according to the present embodiment is applied to a constant torque electric screwdriver or the like. That is, in FIG. 3, reference numeral 30 indicates a gripping part casing of the electric driver, and the gripping part casing 30 has an electric motor 32 and the torque limiter TL of this embodiment incorporated therein.

  That is, in FIG. 3, the drive output shaft 34 of the electric motor 32 is coupled to the drive shaft coupling portion 12 of the drive side rotating body 10 of the torque limiter TL. In this case, a pair of magnets 18 and 18 as sensor sensing members are embedded symmetrically in the circumferential direction of the drive side rotator 10 and correspond to these magnets 18 and 18 respectively. Hall elements 28 and 28 as sensors are arranged in the gripping part casing 30. Then, a tool (driver bit or the like) 36 is coupled to the driven shaft coupling portion 22 with respect to the driven side rotating body 20.

  FIG. 4 is an explanatory diagram showing a configuration in which the torque limiter TL having the above-described coupling configuration is assembled as a constant torque electric driver. That is, in this embodiment, the drive output shaft 34 of the electric motor 32 is coupled to the drive side rotating body 10 of the torque limiter TL, and the driver bit 36 as a tool is connected to the driven side rotation shaft 20 of the torque limiter TL. Are detachably coupled, and are configured to perform screw tightening based on a torque set value (hysteresis torque) defined by the torque limiter TL.

  In FIG. 4, reference numeral 38 is an operation switch provided on the grip casing 30 for manually turning on / off the electric motor 32, and reference numeral 40 is a control for driving and controlling the electric motor 32. Indicates the device. Therefore, in the present embodiment, the operation signal of the torque limiter TL detected by the sensors (Hall elements) 28, 28 provided in the grip casing 30 of the constant torque electric screwdriver is input to the control device 40 and this control is performed. The apparatus 40 is configured to determine the operating state of the torque limiter TL and perform drive stop control of the electric motor 32.

  In this embodiment, the torque limiter TL is directly connected to the drive output shaft 34 of the electric motor 32. For example, a speed reduction mechanism such as a planetary gear speed reduction mechanism is connected to the drive output shaft side of the electric motor 32. Thus, the output shaft of the speed reduction mechanism may be coupled to the drive side rotating body 10 of the torque limiter TL.

  Next, the torque control operation when the screw tightening operation is performed using the constant torque electric screwdriver having the above configuration will be described.

  When the constant torque electric screwdriver according to the present embodiment is connected to the power source via the control device 40 and the operation switch 38 is operated to be in the ON state, the electric motor 32 is energized and the drive output shaft 34 is rotated forward. The rotational driving force is transmitted to the driver bit 36 via the torque limiter TL, and the screw tightening operation can be performed.

  In most of the screw tightening steps from the start of the screw tightening operation to the completion of the screw tightening, the driven side rotating body 20 and the magnetic body 24 of the torque limiter TL rotate integrally with the rotation of the driver bit 36. Accordingly, in this case, signals obtained by continuously detecting the sensor sensing members (magnets) 18 and 18 provided on the driving side rotating body 10 in the sensors (Hall elements) 28 and 28 provided on the gripper casing 30. Based on the (pulse signal), the rotation state of the driven rotary body 20 and the driver bit 36 can be determined by the control device 40.

  Next, in the screw tightening process, the screw tightening torque obtained from the electric motor 32 is applied to the driver bit 36 via the torque limiter TL. In this case, when the load torque applied to the driver bit 36 generated when the screw is tightened exceeds a specified torque value (hysteresis torque) set in the torque limiter TL, the permanent magnets disposed opposite to each other built in the torque limiter TL. 14 and the magnetic body 24 slide (slip), the drive side rotating body 10, that is, the drive output shaft 34 of the electric motor 32 idles, and the rotation of the driven side rotating body 20 stops. Accordingly, in such a state, continuous detection of the sensor sensing members (magnets) 18 and 18 (generation of pulse signals) by the sensors (hall elements) 28 and 28 cannot be obtained. The stop state of the body 20 and the driver bit 36 can be determined by the control device 40.

  Thus, in the constant torque electric screwdriver of this embodiment, the screw tightening with the specified torque value (hysteresis torque) set by the torque limiter TL can be completed in the screw tightening operation described above. In this case, the control device 40 that detects and determines the stop state of the driver bit 36 is configured to cut off the power supply to the electric motor 32, so that the electric motor 32 is independent of the operation of the operation switch 38. Stop driving. Therefore, with the constant torque electric screwdriver of this embodiment described above, the screw tightening torque characteristics when performing the screw tightening work, the sensor detection signal for controlling the tightening torque, the electric motor drive power supply, and the time series change characteristics of the load current Can be easily obtained.

  Further, in the constant torque electric screwdriver of this embodiment, the load current at the time of completion of screw tightening, that is, the operation of the torque limiter TL is detected for the electric motor 32, so that the constant torque electric screwdriver can be used for a long time. When the load current value is confirmed to change more than a predetermined value from the initial detection, it can be predicted that the set torque value (hysteresis torque) fluctuates due to wear deterioration of the torque limiter TL. For example, if the load current value has decreased from the initial detection time, it is assumed that the set torque value of the torque limiter TL has decreased.

  Therefore, in the present invention, for example, the control device 40 is configured to detect the load current of the electric motor 32. Then, when the tightening of the screw is completed, that is, when the torque limiter TL is in operation, the load current is detected, and when the load current value is detected to be more than a predetermined change from the current value at the initial detection, a required alarm is generated. Set to By configuring in this way, a change in the set torque value (hysteresis torque) due to wear deterioration of the torque limiter TL is confirmed, and the outer peripheral portion of the cylindrical magnetic body 24 in the driven side rotating body 20 of the torque limiter TL. On the other hand, a cover member 26 made of a magnetic material formed in a cylindrical shape having a cut in the longitudinal direction and having spring elasticity so as to partially surround the outer periphery thereof is prepared. Is appropriately selected and mounted, and fluctuations in the set torque value (hysteresis torque) of the torque limiter TL can be corrected.

  Further, in the present invention, the load voltage of the electric motor 32 is configured to be detected, and in the same manner as described above, when the load voltage value is detected to be a predetermined change or more than the voltage value at the time of initial detection, It can also be set to generate the required alarm. Also in this case, in the same manner as described above, the torque limiter TL is checked for fluctuations in the set torque value (hysteresis torque) due to wear deterioration, etc. Variations in the TL set torque value (hysteresis torque) can be corrected.

  Furthermore, in the present invention, not only the variation of the set torque value (hysteresis torque) due to wear deterioration of the torque limiter TL described above, for example, when attaching a precision screw to a fragile material as an object to be tightened, It is necessary to adjust the set torque value (hysteresis torque). Even in such a case, the set torque value (hysteresis torque) of the torque limiter TL can be adjusted by appropriately selecting and mounting the cover member 26 as in the case described above.

  Although the preferred embodiment of the present invention has been described above, the torque limiter TL according to the present invention is driven by the drive-side rotating body 10 by manual or other power (such as air) other than the electric motor. Connect the output shaft, and connect various tools such as screw taps and drills for tapping to the driven side rotating body 20 to provide various manual or powered handsets other than the constant torque electric screwdriver. As a tool, it can be applied in a wide range.

  Further, in the present invention, the cover member is not limited to the configuration described in the above-described embodiment, and various modifications or aspects can be made with respect to the shape configuration and the mounting method to the torque limiter. In addition to other torque limiters, a one-way clutch or the like can be combined to enable the reverse rotation of the driven side rotating body so that screw removal and other operations can be simplified. Many design changes can be made within a range not to be performed.

DESCRIPTION OF SYMBOLS 10 Drive side rotary body 12 Drive shaft coupling | bond part 14 Permanent magnet holding member 16 Permanent magnet 18 Sensor sensing member (magnet)
20 driven side rotating body 22 driven shaft coupling part 24 magnetic body 26 cover members 26a, 26b cut 28 sensor (Hall element)
30 Electric screwdriver 32 Electric motor 34 Drive output shaft 36 Tool (driver bit)
38 Operation switch 40 Control device TL Torque limiter

In this case, the torque limiter is provided with a cylindrical permanent magnet on the outer peripheral surface of a cylindrical permanent magnet holding member having a drive shaft coupling portion, and is coupled to the drive shaft coupling portion adjacent to the permanent magnet holding member. A drive-side rotating body that is arranged so that the drive output shaft can be inserted therethrough, and a cylindrical magnetic body that is arranged coaxially with the permanent magnet holding member and that is arranged on the outer periphery of the permanent magnet, and the magnetic body And a driven-side rotating body having a driven shaft coupling portion that is coupled to one end portion. And the magnetic material formed in the cylindrical shape which has a cut | interruption in a longitudinal direction and has spring elasticity so that the outer periphery can be partially enclosed with respect to the outer peripheral part of the said cylindrical magnetic body of the said torque limiter By providing a cover member made of the above, it is possible to change the hysteresis torque between the permanent magnets magnetically coupled to each other and the magnetic material facing the permanent magnets.

When the torque limiter configured as described above is used in a constant torque electric driver, for example, the drive output shaft of the electric motor is inserted into the driving side rotating body to drive the permanent magnet holding member. It is set so as to be coupled with the shaft coupling portion, and a pair of magnets as sensor sensing members are symmetrically embedded in the drive-side rotator at equal intervals in the circumferential direction, with respect to the driven-side rotator. The constant torque electric screwdriver can be assembled by setting the screwdriver bit as a tool to be coupled to the driven shaft coupling portion.

A torque limiter in a constant torque electric screwdriver or the like according to claim 2 of the present invention is provided with a cylindrical permanent magnet on an outer peripheral surface of a cylindrical permanent magnet holding member having a drive shaft coupling portion, and the permanent magnet holding member. A drive-side rotating body that is disposed so that a drive output shaft such as an electric motor can be inserted so as to be coupled to the drive shaft coupling portion adjacent to the drive shaft coupling portion, and is disposed coaxially with the permanent magnet holding member. A cylindrical magnetic body is arranged on the outer periphery of the permanent magnet so as to be magnetically coupled to each other, and is composed of a driven side rotating body having a driven shaft coupling portion coupled to one end portion of the magnetic body, A cover member made of a magnetic material having a cut in the longitudinal direction and having a spring elasticity is attached to the outer periphery of the cylindrical magnetic body so as to partially surround the outer periphery. And characterized by providing freely.

A torque limiter in a constant torque electric screwdriver or the like according to claim 4 of the present invention is connected to a drive shaft coupling portion of a permanent magnet holding member through a drive output shaft of an electric motor or the like with respect to the drive side rotating body. And a magnet as a pair of sensor sensing members is embedded symmetrically in the circumferential direction at equal intervals in the drive side rotator, and the driven shaft with respect to the driven side rotator. It is characterized by setting so that a required tool may be combined with a connection part.

The torque limiter in the constant torque electric screwdriver or the like according to claim 5 of the present invention is configured such that the drive output shaft and the driver bit of the electric motor can be attached to and detached from the drive shaft coupling portion and the driven shaft coupling portion of the torque limiter, respectively. The driver is inserted and coupled , and is rotatably housed and disposed in a gripping part casing of an electric screwdriver, and a sensor comprising a Hall element is disposed in the gripping part casing in correspondence with a sensor sensing member provided in the torque limiter. In the screw tightening operation by the bit , the state in which the permanent magnet holding member coupled to the drive output shaft of the torque limiter idles and the driven side rotating body and the driving side rotating body stop rotating is detected by the sensor, and the electric motor Actuation of torque limiter detected by the sensor as well as driving stop control A control device that detects a load current or a load voltage of the electric motor and generates a required alarm when the load current value or the load voltage value changes by a predetermined value compared to the initial value is provided. It is characterized by comprising a torque electric screwdriver.

According to the torque limiter in the constant torque electric driver or the like according to claim 4 of the present invention, the electric motor and other drive output shafts are inserted into the drive side rotating body, and the drive shaft coupling portion of the permanent magnet holding member is In addition to coupling , various tools are coupled to the driven rotor, so that the torque limiter setting torque value (hysteresis torque) must be adjusted for the required screw tightening and other operations. Accordingly, it can be carried out simply and easily and appropriately.

1 and 2, the torque limiter TL of the present embodiment includes a driving side rotating body 10 and a driven side rotating body 20. For the drive-side rotating body 10 , a cylindrical permanent magnet 16 is provided on the outer peripheral surface of a cylindrical permanent magnet holding member 14 having a drive shaft coupling portion 12, and adjacent to the permanent magnet holding member 14 . The drive shaft coupling portion 12 is arranged so that drive output shafts, which will be described later, can be inserted so as to be coupled to each other . The driven-side rotating body 20 has a driven shaft coupling portion 22, is disposed coaxially with the permanent magnet holding member 12, and magnetically couples a cylindrical magnetic body 24 to the outer periphery of the permanent magnet 16. In this way, it is configured to be opposed to each other and coupled to one end of the magnetic body 24.

In the torque limiter TL of the present embodiment configured as described above, the permanent magnet 16 is moved via the drive shaft coupling portion 12 of the permanent magnet holding member 14 by the rotational drive of the drive output shaft inserted through the drive side rotating body 10. Rotates integrally. When the drive shaft coupling unit 12 is rotationally driven, the magnetic bodies 24 arranged so as to be magnetically coupled to the permanent magnets 16 are in a coupling relationship based on a hysteresis torque value set in advance. The driven rotary body 20 is rotationally driven integrally with the permanent magnet 16 via the magnetic body 24, and the drive rotary body 10 is also rotationally driven . Such a configuration is basically the same as that of a conventional torque limiter.

In this case, the outer periphery of the cylindrical magnetic body 24 in the driven-side rotating body 20 of the torque limiter TL has cuts 26a and 26b in the longitudinal direction so that the outer periphery can be partially surrounded. by providing the cover member 26 made of magnetic material formed into a cylindrical shape having spring elasticity, and the permanent magnet 14, it is possible to change the hysteresis torque between the magnetic body 24 opposed thereto.

That is, in FIG. 3, the drive output shaft 34 of the electric motor 32 is inserted into the drive-side rotating body 10 of the torque limiter TL and coupled to the drive shaft coupling portion 12 of the permanent magnet holding member 16 . In this case, a pair of magnets 18 and 18 as sensor sensing members are embedded symmetrically in the circumferential direction of the drive side rotator 10 and correspond to these magnets 18 and 18 respectively. Hall elements 28 and 28 as sensors are arranged in the gripping part casing 30. Then, a tool (driver bit or the like) 36 is coupled to the driven shaft coupling portion 22 with respect to the driven side rotating body 20.

In this embodiment, the torque limiter TL is directly connected to the drive output shaft 34 of the electric motor 32. For example, a speed reduction mechanism such as a planetary gear speed reduction mechanism is connected to the drive output shaft side of the electric motor 32. Thus, the output shaft of the speed reduction mechanism can be coupled to the drive shaft coupling portion 12 of the torque limiter TL.

Next, in the screw tightening process, the screw tightening torque obtained from the electric motor 32 is applied to the driver bit 36 via the torque limiter TL. In this case, when the load torque applied to the driver bit 36 generated when the screw is tightened exceeds a specified torque value (hysteresis torque) set in the torque limiter TL, the permanent magnets disposed opposite to each other built in the torque limiter TL. 14 and the magnetic body 24 slide (slip), the drive output shaft 34 of the electric motor 32 idles, and the rotation of the driven side rotating body 20 and the driving side rotating body 10 stops. Accordingly, in such a state, continuous detection of the sensor sensing members (magnets) 18 and 18 (generation of pulse signals) by the sensors (hall elements) 28 and 28 cannot be obtained. The stop state of the body 20 and the driver bit 36 can be determined by the control device 40.

Although the preferred embodiment of the present invention has been described above, the torque limiter TL according to the present invention drives the drive-side rotating body 10 manually or by other power (such as air) other than the electric motor. The shaft is inserted and configured to be coupled to the drive shaft coupling portion of the permanent magnet holding member, and various tools such as a screw tap and a drill for tapping are coupled to the driven side rotating body 20. However, it can be widely applied as various manual or powered hand-held tools other than the constant torque electric screwdriver.

Claims (5)

  A torque limiter comprising a drive-side rotator and a driven-side rotator, and provided with a cylindrical permanent magnet magnetically coupled to the rotator and a magnetic body disposed opposite to the outer periphery thereof. A torque limiter in a constant-torque electric screwdriver or the like, wherein a cover member made of a magnetic material is detachably provided so as to partially surround the outer periphery of the body.   A cylindrical permanent magnet is provided on the outer peripheral surface of a cylindrical permanent magnet holding member having a drive shaft coupling portion, and is coupled to one end of the permanent magnet holding member so as to communicate with the drive shaft coupling portion. A drive-side rotator is disposed coaxially with the permanent magnet holding member, and is arranged opposite to the outer periphery of the permanent magnet so as to be magnetically coupled to each other and coupled to one end of the magnetic body. A driven-side rotating body having a driven shaft coupling portion, and having a cut in the longitudinal direction so as to partially surround the outer periphery of the cylindrical magnetic body. A torque limiter in a constant torque electric screwdriver or the like, wherein a cover member made of a magnetic material formed in a cylindrical shape having spring elasticity is detachably provided.   3. The constant torque electric motor according to claim 1, wherein the cover member is configured to be provided with a plurality of cover members in which an area surrounding the outer peripheral portion of the magnetic body is appropriately changed and selectively used. 4. Torque limiter for drivers.   A setting is made so that a drive output shaft such as an electric motor is coupled to the drive shaft coupling portion with respect to the drive side rotator, and a pair of sensors are arranged at equal intervals in the circumferential direction inside the drive side rotator. 4. A magnet as a sensing member is embedded symmetrically, and a setting is made such that a required tool is connected to the driven shaft coupling portion of the driven rotating body. Torque limiter in the constant torque electric screwdriver described in 1. The drive output shaft and the driver bit of the electric motor are detachably and interchangeably coupled to the drive shaft coupling portion and the driven shaft coupling portion of the torque limiter, respectively, and are rotatably housed and arranged in the gripping portion casing of the electric driver. A sensor composed of a Hall element is arranged in the gripper casing in correspondence with a sensor sensing member provided in the torque limiter, and in the screw tightening operation by the driver bit, the driving side rotating body of the torque limiter is idled. The state where the driven-side rotating body stops rotating is detected by the sensor, and the drive stop control of the electric motor is performed, and the load current or the load voltage of the electric motor is detected when the torque limiter detected by the sensor is operated. The load current value or load voltage value changes by a predetermined value compared to the initial value. Case, the torque limiter in the constant torque electric screwdriver or the like according to any one of the four claims 1 formed by the constant torque electric screwdriver having a control device for generating the required alarm.

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