GB2427664A - Work machine with spring loaded brake used as a service brake - Google Patents
Work machine with spring loaded brake used as a service brake Download PDFInfo
- Publication number
- GB2427664A GB2427664A GB0609395A GB0609395A GB2427664A GB 2427664 A GB2427664 A GB 2427664A GB 0609395 A GB0609395 A GB 0609395A GB 0609395 A GB0609395 A GB 0609395A GB 2427664 A GB2427664 A GB 2427664A
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- United Kingdom
- Prior art keywords
- brake
- line
- valve
- spring
- work machine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
- B60T13/12—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid
- B60T13/22—Brakes applied by springs or weights and released hydraulically
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T15/00—Construction arrangement, or operation of valves incorporated in power brake systems and not covered by groups B60T11/00 or B60T13/00
- B60T15/02—Application and release valves
- B60T15/04—Driver's valves
- B60T15/041—Driver's valves controlling auxiliary pressure brakes, e.g. parking or emergency brakes
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- Engineering & Computer Science (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Braking Systems And Boosters (AREA)
Abstract
A work machine, such as a truck, has a spring loaded brake 2, e.g. a parking brake, which is engaged by a spring 5a, 5b and released when connected via a hydraulic circuit to a pump 15. When a service brake input device, e.g. pedal 25, is not activated, braking pressure in brake line 7 is determined by spring (21, fig 2) of brake valve 8. As the pedal 25 is pushed downwards it operates a pressure reducing valve 8a which reduces the pressure in line 7 thereby allowing the brake 2 to be engaged. By varying the position of the pedal 25 controls the brake 2 as a meterable service brake. A control valve 29a has a first, second and third switching positions (30a-30c), in the first position the brake 2 is used as a service brake, in the second position the brake 2 is used as a parking brake and in the third position the brake 2 is in a release state so that the truck may be towed.
Description
Work machine with a spring-loaded brake The invention relates to a work
machine, in particular an industrial truck, with a spring-loaded brake, which can be used as a parking brake, with a braking position and a release position, wherein the spring-loaded brake can be connected, for release, to a hydraulic pressure means source.
In mobile work machines configured as industrial trucks, a spring- loaded brake is provided, which is used as a parking brake. With the springloaded brake loaded in the braking position, the industrial truck can be held at a standstill on gradients or when the travelling mechanism is not activated.
During travel of the industrial truck, the spring-loaded brake is loaded into the release position. The spring-loaded brake is loaded here by a spring into the braking position and can be loaded into the release position by a braking pressure generated by a pressure means source counter to the force of the spring.
A generic work machine configured as an industrial truck, with a springloaded brake used as a parking brake is known from DE 197 52022 Al.
In the case of work machines of this type, a service brake is also required, with which a metered deceleration of the industrial truck can be achieved by an operator on actuation of a service brake input device. In the case of known work machines, apart from the spring-loaded brake, a separate service brake is provided for this purpose, for example a mechanical or hydraulic service brake, producing a high outlay for construction for the service brake.
The present invention is based on the object of providing a work machine of the type mentioned at the outset, which can be provided with a service brake with a low outlay for construction.
This object is achieved according to the invention in that the springloaded brake can be used as a service brake, wherein a brake valve generating a braking pressure is provided, which is in operative connection with a service brake input device, in particular a brake pedal and, on actuation of the service brake input device, can be loaded in the direction of a reduction in the braking pressure present at the springloaded brake.
According to the invention, the service brake is therefore formed by the spring-loaded brake forming the parking brake, wherein the brake valve, which generates the braking pressure to release the spring-loaded brake, is in operative connection with a service brake input device and reduces the braking pressure acting on the spring-loaded brake in the direction of the release position upon actuation of the service brake input device, so the spring-storage brake is loaded in the direction of the braking position.
Consequently, as a function of the actuation of the service brake input device via a reduction in the braking pressure loading the spring-loaded brake into the release position, a metered activation of the spring-loaded brake in the direction of the braking position is achieved, so the springloaded brake, in addition to the parking brake, can be used as a metered service brake, with which controlled declaration of the work machine by the operator is made possible. For the use of the parking brake as a service brake, only a corresponding brake valve is required for activation of the spring-loaded brake, so the service brake can be produced with a low outlay for construction.
According to a preferred embodiment of the invention, the parking valve is configured as a pressure reduction valve, in particular a three-way pressure reduction valve, which, on the input side, is connected to a braking pressure supply line that is connected to the conveying line of the pressure means source, and on the output side, is connected to a brake line, which is connected to a control pressure chamber of the spring-loaded brake acting in the direction of the release position. The braking pressure loading the spring-loaded brake into the release position can easily be generated with a pressure reduction valve of this type and the spring-loaded brake can be used as a service brake owing to a reduction in the braking pressure.
The pressure reduction valve can expediently be loaded by means of a spring in the direction of a switching position connecting the braking pressure supply line with the brake line and can be loaded by the braking pressure present in the brake line counter to the spring in the direction of a switching position connecting the brake line to a container line. The braking pressure loading the spring-loaded brake into the release position is easily generated with a three-way pressure reduction valve of this type.
Particular advantages are produced when the pressure reduction valve can be loaded as a function of the actuation of the service brake input device in the direction of the switching position connecting the brake line with the container line. As a result, the braking pressure acting on the spring-loaded brake into the release position can easily be reduced as a function of the actuation of the service brake input device by corresponding actuation of a control slide of the pressure reduction valve and therefore the parking brake can be loaded by a metered activation as a service brake in the direction of the braking position.
The pressure reduction valve can expediently be loaded here into the switching position connecting the brake line to the container line by means of a spring which is in operative connection with the service brake input device. On actuation of the service brake input device, the pressure reduction valve is loaded in the direction of the switching position connecting the brake line to the container line by corresponding loading of the spring, so the braking pressure can be reduced as a function of the actuation of the service brake input device and the spring-loaded brake can be used as a service brake.
Particular advantages are produced here when the spring can be loaded in the direction of an increase in the spring force as a function of the actuation of the service brake input device. A reduction in the braking pressure and therefore a loading of the spring-loaded brake into the braking position can thus be achieved with increasing actuation of the service brake input device and therefore with increasing biasing of the spring by corresponding loading of the pressure reduction valve.
The spring-loaded brake can easily be controlled if, according to a preferred development of the invention for directing the parking brake between the braking position and the release position of the springloaded brake, a control valve is provided.
According to one embodiment of the invention, the control valve is arranged in a branch line connecting the brake line to the container, the control valve having a first switching position, in which the branch line is closed off and has a second switching position in which the branch line is open. The spring-loaded brake can easily be controlled in the capacity as a parking brake with a control device of this type, wherein in the first switching position of the control valve, the spring-loaded brake is loaded into the release position and, in the second switching position of the control valve, the spring-loaded brake is loaded into the braking position.
To tow the work machine, the spring-loaded brake can easily be loaded into the release position when the control valve is arranged in a supply branch line leading from an additional pressure means source to the braking pressure supply line and has a third switching position, in which the supply branch line is open. In the third switching position of the control valve, a braking pressure loading the spring-loaded brake into the release position can therefore easily be generated in the braking pressure supply line via the additional pressure means source, for example a hand pump.
A stop valve opening in the direction of the braking pressure supply line, in particular a check valve, is expediently arranged here in the supply branch line downstream from the control valve.
The spring-loaded brake can easily be loaded into the release position to tow the work machine if, according to a further embodiment of the invention, the control valve is arranged in a branch line, which connects a pump pressure chamber, which is in operative connection with the service brake input device and is connected to the brake line, to the container, wherein the control valve has a first switching position, in which the branch line is open, and has a second switching position in which the branch line is closed off. In the second switching position of the control valve, a braking pressure can therefore be generated to release the spring-loaded brake, by means of an actuation of the service brake input device via the pump pressure chamber, wherein the service brake input device forms an additional pressure means source with the pump pressure chamber and therefore the spring-loaded brake can be loaded into the release position to tow the work machine without a separate additional pressure means source, with a low outlay for construction.
The control valve is expediently arranged in the brake line, the brake line being open in the first switching position and the brake line being closed off in the second switching position. Consequently it is easily made possible for the connection of the brake line to the brake valve to be closed off in the second switching position of the control valve and therefore a braking pressure to release the spring-loaded brake can be generated via the pump pressure chamber on actuation of the service brake input device.
The pump pressure chamber can easily be connected to the brake line when the pump pressure chamber is connected to the brake line by means of a supply branch line, a stop valve opening in the direction of the brake line, in particular a check valve, being arranged in the supply branch line.
Owing to the stop valve, a connection of the brake line to the pump pressure chamber is easily avoided here in the first switching position of the control valve.
A pressure limitation device is expediently associated with the supply branch line, whereby the braking pressure generated on actuation of the service brake input device in the supply branch line to release the spring- loaded brake, can easily be limited.
If the pump pressure chamber is connected to the container by means of a stop valve opening in the direction of the pump pressure chamber, in particular a check valve, the pump pressure chamber can easily be connected, in the second switching position of the control valve on actuation of the service brake input device, to the container to draw in pressure means.
A low outlay for construction for the pump pressure chamber and therefore for the additional pressure means source can be achieved if, according to a preferred embodiment of the invention, the pump pressure chamber is formed by a spring chamber of the pressure reduction valve, in which the spring, which is in operative connection with the service brake input device, is arranged.
The control valve is expediently configured as a mechanically actuable switching valve. Consequently, a reliable activation of the spring- loaded brake as a parking brake is possible, with it being possible to activate the spring-loaded brake in the capacity of a parking brake via the control valve and in the capacity of a service brake via the brake valve by separate actuation paths.
The spring-loaded brake according to the invention can be used as a service brake in work machines, for example industrial trucks, with an electric travelling mechanism.
In a work machine with a hydrostatic travelling mechanism, which has at least one hydro unit which can be adjusted with respect to the conveying volume, special advantages are produced if, according to a development of the invention, a control pressure line is connected to the braking pressure supply line, which control pressure line is guided to an actuator controlling the conveying volume of the hydro unit, a control valve device being arranged in the control pressure line. A control signal can thus be easily produced in the braking operation of the work machine, which limits the conveying volume of the hydro unit during overrun, for example during a downhill journey.
The control valve device is configured according to a preferred embodiment of the invention, as an adjustable pressure reduction valve, in particular an electrically adjustable pressure reduction valve. A control signal can thus be easily generated for loading the actuator of the hydro unit.
If a stop valve opening in the direction of the brake valve, in particular a check valve, is arranged in the braking pressure supply line, the spring- loaded brake can easily be secured against leakage.
According to an advantageous embodiment of the invention, a pressure means store is associated with the braking pressure supply line. The braking pressure loading the spring-loaded brake into the release position can easily be provided with a pressure means store, with energy- saving operation of the spring-loaded brake being achieved, in particular in the case of an industrial truck with an electric drive system.
Further advantages and details of the invention are described in more detail with the aid of the embodiments shown in the schematic figures, in which Figure 1 shows the connection diagram of an embodiment of a springloaded brake of an industrial truck; Figure 2 shows a cutout of Figure 1 in an enlarged view; Figure 3 shows a development of the invention in the view according to Figure 2; and Figure 4 shows a second development of the invention in a view according to Figure 2.
Figure 1 shows a hydraulic connection diagram of a work machine configured as an industrial truck. The industrial truck has a travelling mechanism formed by travelling motors 1 a, 1 b, for example hydro motors or electric motors, which are in drive connection with drive wheels, not shown, via a spring-loaded brake 2. The spring-loaded brake 2 comprises, for example, braking devices 3a, 3b, which are configured, for example, as multiple disc brakes, and associated with the travelling motors 1 a, 1 b and which can be loaded by means of an actuating device 4a, 4b between a release position and a braking position. The actuating device for 4a, 4b comprises an actuating piston, which can be loaded by a spring 5a, 5b in the direction of the braking position of the braking devices 3a, 3b. On the actuating piston there is also a control pressure chamber 6a, 6b which acts in the direction of the release position of the braking devices 3a, 3b and therefore counter to the spring 5a, 5b and which is connected to a brake line 7 carrying a braking pressure.
The brake line 7 is connected according to the invention on the output side to a brake valve 8 configured as a pressure reduction valve 8a, the brake valve being connected on the input side to a braking pressure supply line 9. The braking pressure supply line 9 is connected, with interposition of a pressure reduction valve 10, to a conveying branch line 11, which is connected to a conveying branch line 12 for the working hydraulics of the industrial truck to which hydraulics control valves, not shown, for controlling a lift drive, a tilting drive and at least one additional drive of the industrial truck, are connected. The conveying branch line 12 is connected, with interposition of a priority valve 13, to the conveying line 14 of a pressure means source 15 configured as a pump. The pressure means source 15 is in drive connection with a drive motor 16 configured as an electric motor or combustion engine and draws pressure means from a container 17. A hydraulic steering device of the industrial truck, not shown, can preferably be supplied with pressure means from the conveying line 14 via a conveying branch line 18 by means of the priority valve 13.
Arranged in the braking pressure supply line 9 guided from the pressure reduction valve 10 to the brake valve 8, is a stop valve 19 opening in the direction of the brake valve 8 and configured as a check valve.
Downstream from the stop valve 19, a pressure means store 2Ois connected to the braking pressure supply line 9.
The brake valve 8 which is connected on the input side to a braking pressure supply line 9 and, on the output side, connected to the brake line 7 and configured as a three-way pressure reduction valve 8a - as shown in Figure 2-is loaded by means of a spring 21 in the direction of a switching position connecting the braking pressure supply line 9 to the brake line 7. The pressure reduction valve 8a is loaded counter to the force of the spring 21 by the braking pressure present in the brake line 7 in the direction of a switching position connecting the brake line 7 to a container line 23 leading to the container 17. For this purpose, a control line 22 branches off from the brake line 7 which is guided to a corresponding control pressure chamber of the pressure reduction valve 8a counteracting the spring 21.
The pressure reduction valve 8a can be loaded in the direction of the switching position connecting the brake line 7 to the container line 23 as a function of the actuation of a service brake input device 25 configured as a brake pedal. For this purpose, a spring 26, which is arranged in a spring compartment is provided on the pressure reduction valve 8a and is in operative connection with the service brake input device 25 and loads the brake valve 8a counter to the spring 21 into the switching position connecting the brake line 7 to the container line 23. The spring compartment is connected here to the container line 23.
When the service brake input device 25 is not activated, the braking pressure present in the brake line 7 is determined by the spring 21 of the brake valve 8. With increasing actuation of the service brake input device 25, the spring 26 is loaded in the direction of an increase in the spring force, so the force of the spring 26 counteracting the spring 21 increases and therefore loads the pressure reduction valve 8a in the direction of the switching position connecting the brake line 7 to the container line 23 and therefore the braking pressure present at the spring-loaded brake 2 is reduced. As a function of the actuation of the service brake input device 25, the braking pressure present in the brake line 7 is reduced by means of the pressure reduction valve 8a, so the spring-loaded brake 2 is loaded in the direction of the braking position and can therefore be used as a meterable service brake.
To control the parking brake of the spring-loaded brake, a control valve 29a configured as a mechanically actuable switching valve is provided. The control valve 29a is arranged in a branch line 31 connecting the brake line 7 to the container line 23 and also further activates a supply branch line 32, which is guided from a separate additional pressure means source, not shown, for example a hand-operated pump, to the braking pressure supply line 9. In the supply branch line 32, downstream from the control valve 29a, a stop valve 33 is arranged which is configured, for example, as a check valve, and opens in the direction of the braking pressure supply line.
The control valve 29a has a first switching position 30a configured as a neutral position, in which the branch line 31 and the supply branch line 32 are closed off. In a second switching position 30b the branch line 31 is open. The supply branch line 32 is closed off in the second switching position. In a third switching position 30c, the supply branch line 32 is open and the branch line 31 closed off.
During normal operation of the industrial truck, the control valve 29a is located in the first switching position 30a. The spring-loaded brake 2 and therefore the parking brake are loaded into the release position via the braking pressure present in the brake line 7 and generated by the brake valve 8. On actuation of the service brake input device 25, with increasing actuation of the service brake input device 25, the braking pressure present in the brake line 7 can be reduced here by means of the brake valve 8 and therefore the spring-operated brake 2 can be used as a service brake for controlled deceleration of the industrial truck by a metered activation in the direction of the braking position.
To direct the spring-loaded parking brake 2 as a parking brake info the braking position, the control valve 29a is loaded into the second switching position 30b. The brake line 7 is connected to the container line 23 via the opened branch line 31, so the spring-loaded brake 2 is loaded by the springs 4a, 4b into the braking position. The spring-loaded brake 2 can therefore easily be controlled as a parking brake with the control valve 29a. The control valve 29a is provided as an actuation means for the use of the spring- loaded brake 2 as a parking brake. For the use of the spring-loaded brake 2 as a parking brake, the brake valve 8 actuated by the service brake input device 25 is used as an actuation member. Consequently, a parking brake and a meterable service brake can be implemented with the spring- loaded brake 2, with mutually independent actuation means being provided by the control valve 29a and the brake valve 8.
In order to be able to load the spring-loaded brake 2 into the release position to tow the industrial truck, the control valve 29a is loaded into the third switching position 30c. In the third switching position 30c of the control valve 29a, the supply branch line 32 is open, with it being possible to generate a braking pressure to load the spring-loaded brake 2 into the release position by actuation of the additional pressure means source. The storage element 20 can be loaded here by the additional pressure means source to a high pressure, as the pressure present in the storage element 20 and generated by the additional pressure means source is reduced via the brake valve 8 configured as a pressure reduction valve 8a to the braking pressure required to ventilate the spring-loaded brake 3.
To tow the industrial vehicle, the spring-loaded brake 2 can be loaded easily and with a low outlay for construction into the release position, by means of the control valve 29a.
Figure 3 shows a development of the invention. According to Figure 3, a control pressure line 35 branches from the braking pressure supply line 9 and is guided to an actuator, not shown, controlling the conveying volume of a hydro unit of a hydrostatic travelling mechanism of the industrial truck, for example an adjustment motor and/or and an adjustment pump. Arranged in the control pressure line is a control valve device 36 configured as an electric three-way pressure reduction valve 36a which can be activated, for example, by means of a proportional magnet 38, and is connected via a container branch line 37 to the container line 23. In the non-activated state, the control valve device 36 is in a position connecting the control pressure line 35 to the container branch line 37. On activation of the proportional magnet 38, the control valve device 36 is loaded counter to a spring 39 into a position connecting the control pressure line 35 to a braking pressure supply line 9. By a corresponding activation of the control valve device 36, a control pressure can be generated in the control pressure line 35 to limit the conveying volume of the hydro unit and therefore to limit the braking moment present in the hydrostatic travelling drive in an industrial truck with a hydrostatic travelling mechanism on deceleration of the vehicle in overrun.
Owing to the brake valve 8 and the control valve 29a, the spring- loaded brake 2 can easily be used and controlled with a low outlay for construction as a parking brake and as a brake valve 8. By corresponding actuation of the control valve 29a, the spring-loaded brake 2 can also be easily loaded by means of a separate additional pressure means source into the release position to tow the industrial truck.
Figure 4 shows a development of the invention, a control valve 29b configured as a mechanically actuable switching valve being provided, which is arranged in a branch line 40 and which connects a pump pressure chamber 41 which is in operative connection with the service brake input device 25, to the container. The pump pressure chamber 41 is formed here from the spring chamber, provided with the spring 26, of the brake valve 8 configured as a pressure reduction valve 8a, the branch line 40 being connected to the spring chamber and the container line 23. The control valve 29b is also arranged in the brake line 7. A supply branch line 42 is connected to the pump pressure chamber 41 and is connected to the brake line 7 downstream from the control valve 29b, a stop valve 43 which is open in the direction of the brake line 7 and configured as a check valve being arranged in the supply branch line 42. A pressure limitation device 44 configured as a pressure limitation valve is also associated with the supply branch line 42 and is arranged in a branch line 45, which is guided from the supply branch line 42 to the branch line 40 downstream from the control valve 40b. The pump pressure chamber 41 is further connected to the container by means of a stop valve 46 configured as a check valve and opening in the direction of the pump pressure chamber 41. The stop valve 46 is arranged here in a bypass line 47, which is connected to the branch line 40 bypassing the control valve 29b.
The control valve 29b has a first switching position 30d in which the branch line 40 and therefore the connection of the pump pressure chamber 41 to the container line 23 and the brake line 7 and therefore the connection of the brake valve 8 to the control pressure chamber 6a, 6b acting in the direction of the release position, of the actuating device 4a, 4b are open. In a second switching position 30e of the control valve 29b, the branch line 40 and the brake line 7 are closed off. In the second switching position 30e of the control valve 29b, the section of the brake line 7 connected to the control pressure chamber 6a, 6b is thus closed off and the section of the brake line 7 connected to the brake valve 8 is connected to the section of the branch line 40 connected to the container line 23.
During normal operation of the industrial truck, the control valve 29b is in the first switching position 30d. The spring-loaded brake 2 and therefore the parking brake are loaded into the release position via the braking pressure present in the brake line 7 generated by the brake valve 8. On actuation of the service brake input device 25, with increasing actuation of the service brake input device 25, the braking pressure present in the brake line 7 can be reduced here by means of the brake valve 8 and therefore the spring-loaded brake 2 can be used by means of metered activation in the direction of the braking position, as a service brake for controlled deceleration of the industrial truck. The pump pressure chamber 41 formed by the spring chamber is connected via the branch line 40 and the control valve 29b to the container 17.
To tow the industrial truck, the control valve 29b is loaded into the second switching 30e. In the second switching position 30e of the control valve 29b, the branch line 40 and the brake line 7 are closed off. On actuation of the actuation device 25, pressure means is drawn into the pump pressure chamber 41 from the container 17, via the stop valve 46 and conveyed into the supply branch line 42. A braking pressure to load the spring-loaded brake 2 into the release position can therefore be generated in the brake line 7 by actuation of the service brake input device 25, via the open stop valve 43. The braking pressure generated can be limited by means of the pressure limitation device 44.
The spring-loaded brake 2 can easily be used and with a low outlay for construction, as a parking brake and as a brake valve 8, owing to the brake valve 8 and the control valve 29b. By corresponding actuation of the control valve 29b, to tow the industrial truck, the spring-loaded brake 2 can also be loaded easily and with a low outlay for construction into therelease position by means of the additional pressure means source formed by the actuating device 25 and the pump pressure chamber 41 formed by the spring chamber of the brake valve 8.
Claims (21)
- Claims 1. A work machine, in particular an industrial truck, with aspring- loaded brake, which can be used as a parking brake with a braking position and a release position, wherein the spring-loaded brake can be connected, for release, to a hydraulic pressure means source, characterised in that the spring-loaded brake can be used as a service brake, a brake valve generating a braking pressure being provided, which is in operative connection with a service brake input device, in particular a brake pedal and, on actuation of the service brake input device, can be loaded in the direction of a reduction in the braking pressure present at the spring-loaded brake.
- 2. A work machine according to claim 1, characterised in that the brake valve is configured as a pressure reduction valve, in particular a threeway pressure reduction valve, which is connected, on the input side to, a braking pressure supply line connected to the conveying line of the pressure means source and, on the output side, is connected to a brake line, which is connected to a control pressure chamber of the springloaded brake acting in the direction of the release position.
- 3. A work machine according to claim 2, characterised in that the pressure reduction valve can be loaded by means of a spring in the direction of a switching position connecting the braking pressure supply line to the brake line and can be loaded by the braking pressure present in the brake line counter to the spring in the direction of a switching position connecting the brake line to a container line.
- 4. A work machine according to claim 2 or 3, characterised in that the pressure reduction valve can be loaded as a function of the actuation of the service brake input device in the direction of the switching position connecting the brake line to the container line.
- 5. A work machine according to any one of claims 2 to 4, characterised in that the pressure reduction valve can be loaded by means of a spring which is in operative connection with the service brake input device into the switching position connecting the brake line to the container line.
- 6. A work machine according to claim 5, characterised in that the spring can be loaded as a function of the actuation of the service brake input device in the direction of an increase in the spring force.
- 7. A work machine according to any one of claims] to 6, characterised in that a control valve is provided to control the parking brake between the braking position and the release position of the spring-loaded brake 2.
- 8. A work machine according to claim 7, characterised in that the control valve is arranged in a branch line connecting the brake line to the container, the control valve having a first switching position, in which the branch line is closed off, and has a second switching position, in which the branch line is open.
- 9. A work machine according to claim 8, characterised in that the control valve is arranged in a supply branch line leading from an additional pressure means source to the braking pressure supply line, and has a third switching position in which the supply branch line is open.
- 10. A work machine according to claim 9, characterised in that a stop valve opening in the direction of the braking pressure supply line, in particular a check valve, is arranged in the supply branch line downstream from the control valve.
- 11. A work machine according to claim 7, characterised in that the control valve is arranged in a branch line, which connects a pump pressure chamber which is in operative connection with the service brake input device and is connected to the brake line, to the container, the control valve having a first switching position in which the branch line is open and a second switching position, in which the branch line is closed off.
- 12. A work machine according to claim 11, characterised in that the control valve is arranged in the brake line, the brake line being open in the first switching position and the brake line being closed off in the second switching position.
- 13. A work machine according to claim 11 or 12, characterised in that the pump pressure chamber is connected by means of a supply branch line to the brake line, a stop valve opening in the direction of the brake line, in particular a check valve, being arranged in the supply branch line.
- 14. A work machine according to claim 13, characterised in that a pressure limitation device is associated with the supply branch line.
- 15. A work machine according to any one of claims 11 to 14, characterised in that the pump pressure chamber is connected to the container by means of a stop valve opening in the direction of the pump pressure chamber, in particular a check valve.
- 16. A work machine according to any one of claims 11 to 15, characterised in that the pump pressure chamber is formed by a spring chamber of the pressure reduction valve, in which the spring, which is in operative connection with the service brake input device, is arranged.
- 17. A work machine according to any one of claims 7 to 16, characterised in that the control valve is configured as a mechanically actuable switching valve.
- 18. A work machine according to any one of claims 1 to 17, wherein the work machine is provided with a hydrostatic travelling mechanism which has at least one hydro unit which can be adjusted with respect to the conveying volume, characterised in that a control pressure line is connected to the braking pressure supply line and is guided to an actuator controlling the conveying volume of the hydro unit, a control valve device being arranged in the control pressure line.
- 19. A work machine according to claim 18, characterised in that the control valve device is configured as an adjustable pressure reduction valve, in particular an electrically adjustable pressure reduction valve.
- 20. A work machine according to any one of claims 1 to 19, characterised in that a stop valve opening in the direction of the brake valve, in particular a check valve, is arranged in the braking pressure reduction supply line.
- 21. A work machine according to any one of claims 2 to 20, characterised in that a pressure means store is associated with the braking pressure supply line.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102005022553.5A DE102005022553B4 (en) | 2005-05-17 | 2005-05-17 | Working machine with a spring-loaded brake |
Publications (3)
Publication Number | Publication Date |
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GB0609395D0 GB0609395D0 (en) | 2006-06-21 |
GB2427664A true GB2427664A (en) | 2007-01-03 |
GB2427664B GB2427664B (en) | 2010-12-15 |
Family
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB0609395A Expired - Fee Related GB2427664B (en) | 2005-05-17 | 2006-05-12 | Work machine with spring loaded brake used as a service brake |
Country Status (2)
Country | Link |
---|---|
DE (1) | DE102005022553B4 (en) |
GB (1) | GB2427664B (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102791549A (en) * | 2010-05-20 | 2012-11-21 | 株式会社小松制作所 | Construction machine |
CN109969153A (en) * | 2017-12-28 | 2019-07-05 | 比亚迪股份有限公司 | A kind of truck hydraulic energy assisted braking system |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102007059437A1 (en) | 2007-01-11 | 2008-07-17 | Linde Material Handling Gmbh | Work machine, particularly ground conveyor, has spring-operated brake with actuating pressure area, where spring mechanism of parking brake function is arranged, and for operating brake function brake pressure is subjected |
DE102009031741B4 (en) | 2008-07-29 | 2022-01-05 | Linde Material Handling Gmbh | Mobile working machine with spring-loaded brake |
DE102009031743B4 (en) | 2008-07-29 | 2022-01-20 | Linde Material Handling Gmbh | Mobile work machine with a brake with two pressure chambers |
DE102014107075A1 (en) | 2014-05-20 | 2015-11-26 | Linde Material Handling Gmbh | Work machine with a hydrostatic drive and braking device |
IT202200002669A1 (en) * | 2022-02-15 | 2023-08-15 | Cnh Ind Italia Spa | SERVICE BRAKING SYSTEM |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4072360A (en) * | 1976-05-24 | 1978-02-07 | General Motors Corporation | Hydraulic pressure brake system with spring apply pressure release parking brake mode |
GB2076505A (en) * | 1980-05-23 | 1981-12-02 | Graham Hohn Mackay | Valve |
US5190357A (en) * | 1991-05-24 | 1993-03-02 | International Transquip Industries, Inc. | Air-actuated brake system for vehicles |
US5791750A (en) * | 1994-12-27 | 1998-08-11 | Mercedes-Benz Ag | Arrangement for preventing a vehicle from rolling away |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19752022A1 (en) * | 1997-11-24 | 1999-05-27 | Linde Ag | Industrial truck with electric drive for travel and clamping brake device |
DE19858472A1 (en) * | 1998-12-17 | 2000-06-21 | Fiat Om Carrelli Elevatori | Vehicle, in particular industrial truck, with a service brake and a storage brake |
-
2005
- 2005-05-17 DE DE102005022553.5A patent/DE102005022553B4/en not_active Expired - Fee Related
-
2006
- 2006-05-12 GB GB0609395A patent/GB2427664B/en not_active Expired - Fee Related
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4072360A (en) * | 1976-05-24 | 1978-02-07 | General Motors Corporation | Hydraulic pressure brake system with spring apply pressure release parking brake mode |
GB2076505A (en) * | 1980-05-23 | 1981-12-02 | Graham Hohn Mackay | Valve |
US5190357A (en) * | 1991-05-24 | 1993-03-02 | International Transquip Industries, Inc. | Air-actuated brake system for vehicles |
US5791750A (en) * | 1994-12-27 | 1998-08-11 | Mercedes-Benz Ag | Arrangement for preventing a vehicle from rolling away |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102791549A (en) * | 2010-05-20 | 2012-11-21 | 株式会社小松制作所 | Construction machine |
US8615992B2 (en) | 2010-05-20 | 2013-12-31 | Komatsu Ltd. | Construction machine |
CN102791549B (en) * | 2010-05-20 | 2014-04-16 | 株式会社小松制作所 | Construction machine |
CN109969153A (en) * | 2017-12-28 | 2019-07-05 | 比亚迪股份有限公司 | A kind of truck hydraulic energy assisted braking system |
CN109969153B (en) * | 2017-12-28 | 2020-06-19 | 比亚迪股份有限公司 | Hydraulic power-assisted braking system of forklift |
Also Published As
Publication number | Publication date |
---|---|
DE102005022553B4 (en) | 2017-06-08 |
GB0609395D0 (en) | 2006-06-21 |
GB2427664B (en) | 2010-12-15 |
DE102005022553A1 (en) | 2006-11-23 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 20210512 |