WO1998050615A1

WO1998050615A1 - Device for detecting the direction of a blow jet from a nozzle

Info

Publication number: WO1998050615A1
Application number: PCT/EP1998/002379
Authority: WO
Inventors: Joseph Verhulst
Original assignee: Picanol N.V.
Priority date: 1997-05-07
Filing date: 1998-04-22
Publication date: 1998-11-12
Also published as: BE1011146A3

Abstract

The invention relates to a device for detecting the direction (2) of a blow jet from a nozzle, wherein several essentially bar-shaped basically similar elements (11-14) are provided which are directed substantially perpendicular to the blow jet towards a common center (16). Said elements are kept at a distance to said center and can be moved against the elastic force of the blow jet. The direction of the blow jet coincides with the center (16) when all elements (11-14) are moved in the same way.

Description

Device for detecting the direction of a blow jet from a nozzle

The invention relates to a device for detecting the direction of a blow jet of a nozzle, in particular a nozzle of an air-jet weaving machine, with means to which the blow jet can be applied.

In a known device of the type mentioned at the beginning (JP-A 6-41846), the blowing jet of an auxiliary nozzle, a so-called relay nozzle, is directed onto a pressure-sensitive film which changes its color depending on the pressure. The auxiliary nozzle blows out a conical blow jet, which leads to a discolouration of the area of the film which is acted upon by the air jet. The blowing direction of the auxiliary nozzle is defined as the center of the conical air jet that leads to the center of the discolored area. In the known device, the blowing air jet emerging from the auxiliary nozzle is influenced by the film, so that the blowing direction detected by the device does not exactly match the actual blowing direction of the nozzle, ie the blowing direction without loading a film. The invention has for its object to provide a device of the type mentioned, with which the blowing direction can be detected more precisely.

This object is achieved in that several, essentially rod-shaped, at least approximately identical elements are provided, which are directed essentially transversely to the blowing jet to a common center, which are kept at a distance from the center and which are against the spring force of the blowing jet are deflectable.

The essentially rod-shaped elements have little influence on the blowing jet emerging from the nozzle, so that its direction is practically not changed. The blowing direction can thus be detected quickly and easily. The device can be made robust. Electronic or other display devices are not absolutely necessary to detect the blowing direction of a nozzle.

In an advantageous embodiment it is provided that the essentially rod-shaped elements are held on a common holder which has a free cross section which is larger than the cross section of the blown air jet. This results in a favorable design, in which the blowing direction of the nozzle is not influenced or only to a very small extent by the holder.

Four essentially rod-shaped elements arranged at angular intervals of 90 ° are preferably provided. Four rod-shaped elements arranged in this way are sufficient to check the blowing direction of the nozzle in two perpendicular directions and, if necessary, to adjust it.

In a preferred embodiment, the elements are designed as leaf springs. Such leaf springs allow a simple and particularly robust construction. It is also advantageously provided that the ends facing away from the center the leaf springs protrude from a ring that is clamped in the holder. This results in a particularly simple construction, which enables the leaf springs to be largely identical in design.

In a further embodiment of the invention, a pitot tube is provided in the center, which is preferably attached to the holder. In this way, the pressure of the blowing jet which is blown out of the nozzle, in particular the maximum pressure in the blowing direction, can be measured by means of a measuring device.

In a preferred embodiment of the invention, it is provided that the holder with the essentially rod-shaped elements is attached to a base which is provided with a receptacle for a nozzle holder, in which the nozzle is adjustable and fixable. This makes it possible not only to detect the blowing direction of the nozzle, but also to align the existing blowing direction to a required blowing direction in the event of any deviations. This makes it possible to set the nozzles exactly outside of the air-jet weaving machine relative to their nozzle holders, so that after installation in the air-jet weaving machine they have exactly a predetermined blowing direction.

Further features and advantages of the invention result from the following description of the exemplary embodiments shown in the drawings.

1 shows a device according to the invention for checking and setting the blowing direction of an auxiliary blowing nozzle, a so-called relay nozzle, in a perspective view,

2 is a view of a detail of the device of FIG. 1, 3 is a partially sectioned illustration of a detail of the device of FIG. 1 in the direction of arrow F3 of FIG. 1,

4 is a perspective view of a modified embodiment,

5 is a view similar to FIG. 2 of a detail of FIG. 4,

6 shows a section similar to FIG. 3 through a detail of a modified embodiment,

7 shows a section of a detail of a further modified embodiment, and

8 is a view in the direction of arrow F8 of FIG. 7.

The device 1 shown in FIG. 1 is used to check and adjust the blowing direction 2 of a nozzle 3 for an air-jet weaving machine, in the exemplary embodiment an auxiliary nozzle 3 or relay nozzle. The device 1 contains a base 4 to which a profile part 5 is attached. On the profile part 5, a nozzle holder 8 is attached, with which the auxiliary nozzle 3 is later attached to a sley of the air jet loom. The profile part 5 is provided with a slot 6, to which the nozzle holder 8 can be fastened by means of a fastening means 9 in a manner corresponding to that of a sley. The base 4 has a stop surface 7 for the nozzle holder 8. In a modified embodiment, the base 4 and the profile part 5 are formed in one piece. The design of the nozzle holder 8, the slot 6 and the fastening means 9 corresponds, for example, to the type described in US Pat. No. 5,020,574, so that reference is made to the description in this US Pat. The auxiliary nozzle 3 is set in the nozzle holder 8 as it is afterwards is required in the air jet weaving machine, ie to the blowing direction desired in the air jet weaving machine.

A holder 10 is attached to the base 4 and holds four essentially rod-shaped elements, which in the exemplary embodiment are designed as leaf springs 11, 12, 13, 14. The at least approximately identical leaf springs 11 to 14 lie essentially in a plane that runs essentially perpendicular to the desired direction of the blowing jet 2. The leaf springs 11 to 14 are directed radially to a center 16 and extend into the immediate vicinity of this center 16. The leaf springs 11 to 14 have the same length and maintain a relatively short distance from the center 16, but the leaf springs touch 11 to 14 in the area of the center 16 not. The leaf springs 11 to 14 are arranged at angular intervals of 90 °, so that in each case two leaf springs 11, 13 and 12, 14 are aligned in extension to one another, as long as no air jet is blown out of the auxiliary nozzle 3.

The holder 10 has two plate-shaped elements 17, 18 which have a circular opening 19 which is larger than the conical air jet which is blown from the auxiliary nozzle 3. The leaf springs 11 to 14 begin at the inner edge of the circular opening 19 and are clamped between the two plate-shaped elements 17, 18. They are directed to the center of the circular opening 19, which coincides with the center 16 in the exemplary embodiment. Instead of a circular opening 19, a rectangular or polygonal opening can also be provided. In a modified embodiment, only a plate-shaped element is provided, to which the leaf springs 11 to 14 are attached.

As can be seen from Fig. 2, the leaf springs 11 to 14 are provided in the region of the center 16 with pointed ends, so that they reach relatively close to the center 16 without each other to touch. The leaf springs 11 to 14 are integrally formed with a ring 20 which is attached to the bracket 10. The ring 20 is clamped between the two plate-shaped elements 17, 18. The clamping takes place by means of fastening means 21, which are shown in FIG. 3 and penetrate the bores 22 (FIG. 2) of the ring 20 and bores 23 of the plate-shaped elements 17, 18. The inner edge 24 of the ring 20 is concentric with the center 16.

The bracket 10 is adjustably attached to the base 4. The base 4 has a defined stop surface 26 which is aligned with the stop surface 7 on which the nozzle holder 8 rests. The stop surface 26 is aligned so that the plane of the holder 10 is at least approximately perpendicular to the required blowing direction 2 of the auxiliary nozzle. If necessary, it can be provided that the stop surface 26 is adjustable relative to the base 4. The bracket 10 is attached to the base 4 so that it is adjustable in the vertical and horizontal directions. The bracket

10 has a slot 25, which is penetrated by a fastening means 15, in particular a screw, which is screwed into the base 4. Before checking and adjusting auxiliary nozzles 3 by means of the device 1, the holder 10 is brought into a reference position, as will be explained later.

To check the blowing direction of an auxiliary nozzle 3, it is fastened with its nozzle holder 8 to the profile part 5 of the base 4, the nozzle holder 8 abutting the stop surface 7. A compressed air supply, not shown, i.e. a compressed air line is connected to the connecting element 27 of the auxiliary nozzle 3, so that a, for example, conical blow jet with a blowing direction is blown out of the auxiliary nozzle 3 in the direction of the leaf springs 11 to 14. The leaf springs give way under the influence of the force of the blowing jet

11 to 14 off, ie swivel in the blowing direction. If the blowing direction of the tested auxiliary nozzle 3 does not match the if the desired blowing direction 2 coincides, the leaf springs 11 to 14 are deformed differently, for example in accordance with the illustration in FIG. 3. Here, the leaf springs 11, 12 arranged at an angular distance of 90 ° have deformed more than the leaf springs 13 and 14 Point 28 cuts. The leaf springs, which are closer to the blowing direction 2, deflect further and are more bent than the leaf springs, which are further away from the blowing direction.

In order to set the blowing direction 2 of the auxiliary nozzle 3, the auxiliary nozzle 3 is first rotated in the nozzle holder 8 until the leaf springs 12, 14 opposite one another in the horizontal plane deform uniformly. The auxiliary nozzle 3 is then bent by means of plastic deformation until the essentially vertically oriented leaf springs 11 and 13 are also deformed in the same way. If necessary, these processes are repeated until all leaf springs 11 to 14 deflect to the same extent, i.e. are deformed to the same extent. In this case, the force of the blowing jet acts uniformly on all leaf springs 11 to 14, so that the blowing direction 2 of the auxiliary nozzle 3 runs exactly through the center 16. The auxiliary nozzle 3 is then fixed to the nozzle holder 8 by means of a fastening means 29. The auxiliary nozzle 3 is thus correctly adjusted with respect to its blowing direction 2 to the nozzle holder 8, so that the auxiliary nozzle 3, when it is attached to the sley of an air-jet weaving machine by means of its nozzle holder 8, has a defined blowing direction within the weaving machine.

Since the ends of the leaf spring 11 to 14 are close to each other in the immediate vicinity of the center 16, the difference between a deformation of a leaf spring and that of another leaf spring is clearly visible. This makes it possible also detect small deviations in the blowing direction of the auxiliary nozzle 3 from the desired blowing direction 2.

Since all leaf springs 11 to 14 are made in one piece with the ring 20, they are largely identical to one another. The force of the air jet thus leads to uniform deflection and deformation in all leaf springs 11 to 14 in accordance with the blowing direction. Since the leaf springs 11 to 14 are made in one piece with the ring 20, their spring stiffness is largely identical, so that the absolute spring stiffness of the leaf springs 11 to 14 does not necessarily have to be known for determining the blowing direction of an auxiliary nozzle. It is crucial that all leaf springs 11 to 14 have essentially the same stiffness.

In order to obtain a sufficient reading accuracy, which is dependent on the deformation of the leaf springs 11 to 14, the leaf springs 11 to 14 must deform sufficiently under the forces that occur, for example in the area of their tips, by about 10 mm from the plane of the holder 10 . At blowing pressures from 2 bar to 7 bar and when using auxiliary nozzles 3 which are common today in weaving machines, it has been shown that leaf springs 11 to 14 made of spring steel with a width of approximately 8 mm and a length of approximately 50 mm and a thickness of approximately 0 , 15 mm to 0.4 mm are sufficient. Of course, depending on the type of material of the leaf springs, the blowing pressure used and the auxiliary nozzles used and the distance from the auxiliary nozzle 3 to the leaf springs 11 to 14, deviations from these dimensions are possible.

In order to check and adjust the auxiliary nozzles 3 with regard to their blowing direction, the holder 10 with its leaf springs 11 to 14 must be brought into a reference position which corresponds to the desired blowing direction 2. For this purpose, a reference nozzle is used, ie an auxiliary nozzle 3 with a nozzle holder 8, from which it is known that the blowing direction device 2 is set correctly. The reference nozzle is then attached with its nozzle holder 8 on the profile part 5 to the stop surface 7 on the base 4. A compressed air supply, not shown, is connected to this reference nozzle so that an air jet with the correct blowing direction 2 flows out of the reference nozzle. Then the holder 10 is moved after loosening the fastener 15 on the stop surface 26 into a position in which all leaf springs 11 to 14 are deformed to the same extent by the force of the blow jet, so that the blowing direction 2 of the reference nozzle passes through the center 16. The bracket 10 is then fixed in this position on the base 4 with the aid of the fastening means 15.

The embodiment according to FIG. 4 corresponds in its basic structure and in its function to the embodiment according to FIGS. 1 to 3, so that reference is made to the preceding description insofar as the same reference symbols are used. In this exemplary embodiment, a pitot tube 30 is arranged in the center 16 of the leaf springs 11 to 14. This pitot tube 30 is held by means of a narrow holding bracket 31, which is fastened to the holder 10 of the leaf springs 11 to 14 on the side facing away from the auxiliary nozzle 3. Since the bracket 31 is relatively narrow and is arranged at a greater distance from the leaf springs 11 to 14, it influences the blowing direction 2 of the auxiliary nozzle 3 only slightly. The pitot tube 30 is connected to a measuring device (not shown), for example a pressure gauge or an electronic pressure transmitter, in order to determine the pressure of the blowing jet of the auxiliary nozzle 3. In this embodiment it is provided that the leaf springs 11 to 14 in their basic position, i.e. if no blowing jet is blown out of the auxiliary nozzle 3, something is bent out of the plane of the holder 10 away from the auxiliary nozzle.

In this embodiment, the leaf springs 11 to 14 are designed as shown in FIG. 5. they are provided with a plurality of openings 32 through which the compressed air blown out of the auxiliary nozzle 3 can flow. This offers the advantage that the blowing direction 2 of the auxiliary nozzle 3, even if it does not coincide with the center 16, is only slightly influenced by the leaf springs 11 to 14.

In the exemplary embodiment according to FIG. 6, damping elements 33 and 34 are arranged between the holder 10 and the leaf springs 11 to 14, which interact with the leaf springs 11 to 14 in order to dampen possible vibrations of the leaf springs 11 to 14. For the sake of illustration, only the leaf springs 11 and 13 with the associated damping elements 33, 34 are drawn. The leaf springs 12 and 14 are provided with damping elements in a corresponding manner. The damping elements 33, 34 are, for example, rubber elements which are provided with cutouts at one end and are held on the holder 10 by means of the fastening means 21. The other ends are provided with locking pins 36 which are locked in openings 35 in the leaf springs 11 to 14.

The use of damping elements 33, 34 is particularly advantageous if leaf springs 11 to 14 made of steel are used which have little internal damping. If the leaf springs 11 to 14 are made from a different material, for example from a plastic with sufficient damping properties, additional damping elements can be dispensed with without further ado. Leaf springs 11 to 14 made of spring steel, however, have the advantage that they have a high resistance to plastic deformation and creeping deformation and that they are inexpensive, so that they ensure a long service life.

The leaf springs 11 to 14 do not have to be designed absolutely the same. They only have to have essentially the same shape, so that they deform under the influence of the force of the blowing jet in essentially the same way, that is to say they evade in the same way. Of course you can more than four or even less than four leaf springs can be used. In order to be able to determine the blowing direction 2 with respect to two directions, at least three leaf springs arranged at an angle of 120 ° to one another are required, which likewise extend to the center. If only two leaf springs are used, the blowing direction can also be determined in two directions if, for example, it is provided that the holder with the leaf springs can be rotated about the center 16.

Even if the blowing direction 2 of the auxiliary nozzles 3 can be determined without a display device by means of the device 1 according to the invention, means can of course also be provided to show the deformation of the leaf springs 11 to 14 on a display device. For this purpose, strain gauges, for example, can be attached to the leaf springs 11 to 14, which are switched with an electrical or electronic measuring bridge in order to determine the deflection of the individual leaf springs 11 to 14. In addition, optical measuring devices or distance sensors can also be provided, for example a linear PX.

In the embodiment shown in FIGS. 7 and 8, the rod-shaped elements 37, 38, 39, 40 are rigid strips 41, 42, 43, 44, which are each held in the starting position by means of a spring 45, 46, 47, 48, i.e. in the position without a blast jet. The strips 41 to 44 are each mounted by means of a joint 49 on a shoulder 53 which is attached to a conical retaining ring 50, for example. Holding plates 51 are fastened to the holding ring 50. The springs 45 to 48 are each supported between a bar 41 to 44 and the holding plate 51. The retaining ring 50 is preferably mounted on the base 4 in an adjustable manner by means of an intermediate piece 52.

As can be seen in particular from FIG. 8, the strips 41 to 44 are not exactly aligned with the center 16, but rather are rather each offset from the center 16. The procedure corresponds to the embodiment according to FIGS. 1 to 6, the strips 41 to 44 evading under the influence of the force of the blowing jet of the auxiliary nozzle 3 in that the springs 45 to 48 deform elastically, so that the strips 41 to 44 deflect elastically .

The frusto-conical retaining ring 50 runs parallel to the conical air jet and preferably has a larger diameter. In a modified embodiment, a cage made of rods is provided instead of the frustoconical retaining ring 50, which are also arranged conically, for example.

The rigid strips 41 to 44, like the leaf springs 11 to 14, do not have to have a rectangular cross section. They can be designed as rigid or elastic rods or needles with a round, oval or other cross section.

The device can of course not only be used for setting auxiliary nozzles 3, but also for other nozzles, in particular for nozzles, such as are used in air-jet weaving machines. For example, it is also suitable for stretching nozzles of an air jet weaving machine.

The invention is not limited to the exemplary embodiments explained above, which can also be combined with one another if necessary. Protection is determined solely by the claims.

Claims

claims

1. Device (1) for detecting the direction of a blow jet of a nozzle (3), in particular a nozzle of an air jet weaving machine, with means which can be acted upon by the blow jet, characterized in that a plurality of essentially rod-shaped elements (11 to 14, at least approximately identical to one another) 41 to 44) are provided which are directed essentially transversely to the blowing jet to a common center (16), which are kept at a distance from the center and which can be deflected by the blowing jet against spring force.

2. Device according to claim 1, characterized in that the substantially rod-shaped elements (11 to 14, 41 to 44) are held on a common holder (10, 50) which has a free cross section which is larger than the cross section of the blowing jet is.

3. Apparatus according to claim 1 or 2, characterized in that four substantially rod-shaped elements (11 to 14, 41 to 44) arranged at angular intervals of 90 ° are provided.

4. Device according to one of claims 1 to 3, characterized in that the substantially rod-shaped elements

(11 to 14) are aligned radially to the common center (16).

5. Device according to one of claims 1 to 3, characterized in that the substantially rod-shaped elements

(41 to 44) are arranged offset next to the common center (16).

6. Device according to one of claims 1 to 5, characterized in that the substantially rod-shaped elements

(11 to 14, 41 to 44) are provided with recesses (32) extending essentially in the blowing direction (2).

7. Device according to one of claims 1 to 6, characterized in that the substantially rod-shaped elements

(11 to 14, 41 to 44) are provided with means (33, 34) for damping vibrations.

8. Device according to one of claims 1 to 7, characterized in that the elements are designed as leaf springs (11 to 14).

9. The device according to claim 8, characterized in that the ends of the leaf springs facing away from the center (16)

(11 to 14) protrude from a ring (20) which is clamped in the holder (10), which preferably has two plate-shaped elements (17, 18).

10. Device according to one of claims 1 to 7, characterized in that the substantially rod-shaped elements

(41 to 44) at their end facing away from the center (16) are pivotably mounted on the holder (50) and are supported by means of a spring (45 to 48).

11. Device according to one of claims 1 to 10, characterized in that a pitot tube (30) is provided in the center (16), which is preferably attached to the holder (10).

12. Device according to one of claims 1 to 11, characterized in that the holder (10, 50) with the substantially rod-shaped elements (11 to 14, 41 to 44) is arranged on a base (4) which has a receptacle (5, 6, 7) for a nozzle holder (8) is provided, in which the nozzle (3) is adjustable and fixable.