JP2007512441A - Yarn control device for textile machines, especially for opening devices - Google Patents

Abstract

The invention relates to a thread control device for a textile machine, in particular, for a shedding device, with at least one thread guide body ( 31 ) which may be displaced in one displacement direction by means of a positive drive ( 35 ) and in the opposite direction by means of a non-positive, pneumnatic return device ( 36 ). Me return device ( 36 ) thus comprises a cylinder/piston unit ( 64,54 ), the cylinder chamber of which ( 52 ) is connected to a compressed gas source ( 60 ) by means of a valve ( 56 ). An improvement in control is achieved when the valve ( 56 ) comprises a first valve seat ( 72 ) connected to the cylinder chamber ( 52 ) and a second valve seat ( 76 ), between which a valve body ( 82 ), provided with at least one throttle point ( 80 ), may be displaced, pre-tensioned in the rest position by means of a spring ( 84 ) against the first valve seat ( 72 ), in which the throttle point ( 80 ) is ineffective and the valve body ( 82 ) blocks the communication with the compressed gas source ( 60 ) when the valve body ( 82 ) is in contact with the second valve seat ( 76 ).

Description

  The present invention relates to a yarn control device for a textile machine, particularly an opening device, according to the first stage of claim 1.

  Numerous yarn control devices for textile machines are known. The latest prior art according to WO 97/08373 discloses a yarn control device designed to comprise a drive device and a return device for a yarn guide member. The yarn guide member is in this case movable in one movement direction by a positively designed drive and in a reverse movement direction by a non-positive pneumatically designed return device.

  The pneumatic return device has a cylinder / piston assembly whose cylinder chamber is designed with an overpressure valve and with a check valve connected to a source of compressed gas. In this case, the gas pressure in the cylinder chamber is set according to the operating state of the textile machine. For example, in the slow speed stage, the gas pressure is kept lower than in the high speed stage so that the electric motor can supply the power necessary to overcome the load resulting from the compression of the cylinder chamber. In the high speed phase, the electric motor supplies sufficient power so that the gas pressure can be further increased to prevent the rollers on the cam disk of the positive drive from coming off. In addition, the cylinder chamber can be designed with a manually actuable pressure relief valve to minimize the resistance that occurs as a result of compression in the cylinder chamber when the textile machine is set up.

  The above solution has the disadvantage that the gas pressure in the cylinder chamber has to be adapted to the respective operating conditions. This requires a complex pressure control device to set the cylinder chamber gas pressure, which requires a pressure reducing valve and an open valve to operate each cylinder chamber. In addition, complicated electronic control of the valves is required to adapt the cylinder chamber pressure to the respective operating conditions.

  In order to lubricate the cylinder / piston assembly, oil droplets, for example from above, on the piston enter the cylinder chamber despite the permanent overpressure of the cylinder chamber due to hydrodynamic effects. Oil that accumulates in the cylinder chamber reduces the amount of air in the cylinder chamber to an indeterminate level, thus constantly disturbing the operation of the yarn control device because the compression pressure in the chamber becomes unpredictably high during operation. . In extreme cases where the majority of the cylinder chamber is filled with oil, the cylinder can no longer move and further operation of the textile machine will lead to considerable damage.

  Thus, in an improved embodiment of the pneumatic return device described in WO 97/08373, the valve is designed to allow oil separation in addition to the steady state requirements. In this case, the valve is operated at regular time intervals for several seconds so that the oil accumulated in the compression space flows out. During this operation (known as the care cycle), the rotational speed of the textile machine must be reduced in order to prevent the rollers from detaching from the eccentric of the positive drive. At slow speeds, the valves are similarly opened so that the pressure in the cylinder chamber does not rise much higher than the feed pressure. Thus, the required motor power is reduced, so that the main motor can rotate at a low rotational speed, thus allowing manual rotation of the handwheel without undue effort.

  The disadvantage of the above solution is the high cost for the electro / pneumatic actuation of the valve. Thus, the overall control of the pneumatic control of the yarn control device also has a number of components, such as check valves, overpressure valves, pressure reducing valves, and an electronic control unit that makes the system more prone to failure. Furthermore, the efficiency of the textile machine decreases as a result of repeatedly reducing the rotational speed of the motor every 15 minutes in order to discharge the lubricating oil. Furthermore, this reduction in the rotational speed of the motor can also adversely affect the weaving quality, for example a slight change in the width of the woven fabric produced.

  The object of the present invention is to improve a yarn control device of the kind indicated at the outset.

  The set object is achieved by the feature requirements of claim 1. The valve has a first valve seat connected to the cylinder chamber and has a second valve seat, between which has at least one throttle point and is pressed against the first valve seat by a spring When the valve member is movable and the valve member is in contact with the second valve seat, the throttle point does not operate, and the valve member cuts off the communication with the compressed gas source. It can operate in various operating states without being activated. In addition, there is no additional means by an independently operated valve without reducing the rotational speed, without reducing the maximum compression pressure in the cylinder chamber in partial load conditions, and without reducing the compression pressure to the feed pressure at fine speeds. Reliable oil separation is ensured.

  Advantageous improvements of the invention are described in claims 2 to 19.

  In principle, a very diverse embodiment is conceivable for a valve designed with two valve seats. The housing has two parts, one part having a first valve seat at one end and the other part being designed as a closure for the housing with a second valve seat and a flow duct. The improvement described in 3 is advantageous. Thus, the valve has the simplest possible structure, which allows for cost-effective production and simple assembly of the valve.

  The valve housing can in principle have various shapes, and the cylindrical design of the housing according to claim 4 is advantageous. This design allows for excellent guidance of the piston-like valve member within the housing. Furthermore, the piston-like valve member can be provided with a seal ring to seal the cylinder chamber to the outside. In the version according to claim 4, it is advantageous to design the throttle point as a throttle hole formed in the valve member. According to claim 5, it is also conceivable to design a valve member without a seal ring, in which case the gap between the valve member and the wall of the housing can serve as a throttle point.

  The valve can be arranged in a connection line between the cylinder chamber and the feed pressure chamber. However, a direct arrangement in the cylinder in the cylinder / piston assembly according to claim 6 is advantageous. Furthermore, according to claim 7, it is advantageous to arrange the valve at the lowest point of the cylinder. The valve can thus be in direct communication with the cylinder chamber, and the lubricant accumulated in the cylinder chamber can thus be routed through the valve and into the feed pressure chamber along a short path. Correspondingly, in claim 8 the valve closure is connected directly to the feed pressure chamber in order to minimize again the flow resistance and flow path of the spilled oil.

  The feed pressure chamber can in principle be of any desired design. 13. The feed pressure chamber is designed to have an oil separation outlet at its bottom, and a connection for compressed air is disposed on the side wall at a distance from the bottom of the feed pressure chamber. The design of is advantageous. This arrangement of the compressed air connection and oil separation outlet prevents oil accumulated in the feed pressure chamber from blocking the compressed air connection or flowing into the connection line of the compressed air connection. In principle, every return device can have a separate feed pressure chamber. However, according to claim 12, it is advantageous to connect a plurality of return devices to one feed pressure chamber. A simple configuration with only one connection for compressed air and only one oil separation outlet for multiple return devices is thereby possible.

  In principle, a great variety of designs of the pneumatic return device according to the invention can be envisaged. Claims 13 to 16 together with claims 5 and 6 describe a particularly simple design of the valve in which the valve is arranged at a point below the cylinder chamber of the cylinder / piston assembly. According to claim 13, the lower part of the cylinder can act as a housing for the valve. The valve space is advantageously defined by a cylinder inner surface, a closure for closing the cylinder chamber, and a valve member and can be directly connected to a compressed gas source via a connection arranged on the cylinder wall. According to claim 14, the first valve seat of the valve member can be formed on the annular stopper. According to claim 15, the second valve seat can be formed on the sleeve part of the closing part. When the valve member moves and hits the second valve seat, the communication with the compressed gas source in the cylinder chamber is cut off, and the throttle point of the valve member does not operate. Furthermore, according to claim 16, it is particularly advantageous to arrange the oil separation outlet directly in the closure.

  As soon as the pressure in the feed pressure chamber exceeds the switching pressure, the valve is activated. The switching pressure depends on both the pressure in the feed pressure chamber and the prestressing force of the spring. The refinements according to claims 17 and 18 are advantageous in that the prestressing force can be set externally, for example via screws.

  According to claim 19, the maximum compression pressure of the valve can be set by the flow cross section of the throttle point. If a higher compression pressure is required, the flow cross section at the throttle point is reduced. Due to the smaller throttling area, the communication between the cylinder chamber and the compressed gas source is interrupted early and thus a higher maximum compression pressure is achieved.

  According to the versions of claims 17 to 19, the switching pressure and the maximum compression pressure in the cylinder chamber can be set in a simple manner.

  In the following, an exemplary embodiment of the yarn control device of the present invention will be described in more detail for a needle type ribbon loom using the drawings.

  1 is equipped with a main drive shaft 4 for driving at least one weft thread needle 6 which will not be described in further detail, a heel 7, a fabric winding device 8, and a thread control device formed as a heel frame device 10. 1 shows a needle type ribbon loom having a machine base 2. The needle type ribbon loom has a warp beam stand 12 for supporting the warp yarn beam 14, from which warp yarn 16 is supplied to the heel frame device 10, and the heel frame device opens the warp yarn to form a shed 18. The weft supply device 20 supplies the weft thread 24 from the thread bobbin 22 to the weft thread needle 6, and the weft thread needle introduces the weft thread loop into the shed 18. In order to bind and secure the inserted weft loop, the continuous weft loop is tied by itself or via a further yarn feeding device 28 by means of a tack yarn 26 which is fed to a knitting needle not further shown here. Can do.

  FIG. 2 shows that a plurality of collar frames 30 with a thread guide member 31 are connected to a cam drive device 34 on the one hand via a positive drive device 35 and to a pneumatic return device 36 on the other hand by a connecting rod 32 in any case. The frame device 10 made to be shown is shown. The cam drive 34 has a pivot lever 38 that cooperates with the cam 42 of the camshaft 44 at a drive point 40. At the output point 46, the turning lever 38 is attached to the connecting rod 32 via a joint 48. The pivot axis defined by the joint 48 runs perpendicular to the plane in which the collar frame 30 extends. The distance A of the rotation lever 38 of the drive point 40 from each pivot shaft 50 is different between adjacent rotation levers, and the distance B from the fixed pivot shaft 50 to the output point 46 is also different. The frame is displaceable over a range of different sizes to form a shed that is continuously widened and again narrowed as inferred from FIG. The pneumatic return device 36 is formed by a cylinder chamber 52 in which a piston 54 connected to the connecting rod 32 is displaceable in order to reliably compress the piston at the operating frequency of the cam drive 34. The cylinder chamber 52 is connected to a valve 56. A feed pressure chamber 58 is disposed in front of the cylinder chamber and a compressed gas source 60 is connected through the feed pressure chamber to maintain the gas pressure in the cylinder chamber 52.

  3 and 4 show a more enlarged view of the pneumatic return device during the compression operation. 3 shows the piston 54 at the top dead center 66, and FIG. 4 shows the piston 54 at the bottom dead center 68 in the cylinder 64 after compression. The valve housing comprises two parts: a sleeve-like housing 70 having a first valve seat 72 formed at one end and connected to the cylinder chamber 52; and a closure 74 having a second valve seat 76 and a flow duct 78. . The flow duct is connected to the feed pressure chamber 58. A valve member 82 having a throttle point 80 is movably disposed between the valve seats.

  In the initial state shown in FIG. 3, the valve member 82 is pressed against the first valve seat 72 by the prestressing force of the spring 84, so that the cylinder chamber 52 and the feed pressure chamber 58 are connected to the throttle point 80 and the closing portion of the valve member 82. 74 are connected to each other via 74 passage ducts 78. When the inside of the cylinder chamber 52 is at a high pressure, the valve member 82 moves and hits the second valve seat 76, and the communication between the cylinder chamber 52 and the feed pressure chamber 58 is cut off as shown in FIG. In this position, the aperture point 80 does not operate.

  The compression / expansion operation of the cylinder / piston assembly is described below using FIGS. 3 and 4 with the graphs of FIGS. 7a, 7b, and 7c. In the graph, H represents the piston stroke of the cylinder / piston assembly where UT is the bottom dead center and OT is the top dead center, and PK represents the pressure of the gas in the cylinder chamber. PS represents the switching pressure required for the valve member to switch from the first valve seat to the second valve seat or from the second valve seat to the first valve seat. The switching pressure PS can be divided into a feed pressure PD of the compressed gas source and a corresponding pressure PF of the spring force. In this case, VZ indicates the position of the shut-off valve, and VO indicates the position of the valve communicating with the cylinder chamber via the throttle point.

  Initially, the piston 54 moves down the cylinder 64 from the top and simultaneously, in the first stage, pushes air back toward the feed pressure chamber 58 via the throttle point 80 formed in the piston-like valve member 82. . When the piston speed increases, the switching force generated by the cylinder chamber pressure PK on the valve member 82 overcomes the prestressing force of the spring 84 and the force on the valve member 82 generated by the feed pressure PD, and the valve member 82 becomes the second valve. The pressure difference (PK−PD) before and after the valve member 82 increases until the seat 76 is pressed. The throttle point 80 of the valve member 82 will then no longer operate. Therefore, when the piston 54 further moves toward the valve 56, the pressure PK of the cylinder chamber rapidly increases during the compression operation of the cylinder chamber 52, and reaches its maximum value at the bottom dead center UT. In the expansion phase, as soon as the spring force exceeds the force generated in the valve member 80 as a result of the pressure difference (PK-PD), the valve member 80 moves from the second valve seat to the first valve seat 76. At the end of the expansion phase corresponding to the top dead center 66 of the piston, a feed pressure PD is established in the cylinder chamber. Further, the oil accumulated in the cylinder chamber 52 can then flow out through the flow channel duct 78. During the next compression operation, the spilling oil is blown out by air that is forced away into the feed pressure chamber 58 and exits to an oil separation outlet 88 formed in the bottom 86 of the feed pressure chamber. A connection 90 for compressed air is disposed on the side wall 92 of the feed pressure chamber, thus preventing further backflow of oil.

  Figures 5 and 6 show a further enlarged design variant of the pneumatic return device during the compression operation. In this case, FIG. 5 again shows the piston 54 at top dead center 66, and FIG. 6 shows the piston 54 at bottom dead center 68 in the cylinder 64 after compression of the cylinder chamber 52. The valve 56a is again arranged directly at the lowest point of the cylinder 64. The cylinder wall in this case acts as a valve housing, and the valve space 94 is defined by the wall of the cylinder 64, the closing portion 74a for closing the cylinder 64, and the piston-like valve member 82a. A stopper 71 designed as a ring is disposed directly inside the cylinder 64 of the cylinder / piston assembly and serves as a first valve seat 72a for the piston-like valve member 82a. The latter is again pressed against the first valve seat 72 by the spring 84a with a prestressing force. The spring 84a is in this case supported by a closing part 74a which closes the cylinder and has an inner sleeve part 96 for guiding the spring 84a, and its free end serves as a second valve seat 76a for the valve member 82a. When the valve member comes into contact with the second valve seat 76a, the throttle point formed on the valve member 82a does not operate. Similarly, at this position, the connection 90a disposed in the cylinder for the compressed gas source 60 is blocked by the valve member 82a. The oil accumulated in the cylinder chamber 52 can flow out through the oil separation outlet 88a formed in the closing portion 74a.

  In the initial state shown in FIG. 5, since the valve member 82a is pressed against the first valve seat 72a by the prestressing force of the spring 84a, the cylinder chamber 52 is connected to the compressed gas source via the throttle point 80a of the valve member 82a. . When the inside of the cylinder chamber 52 is at a high pressure, the valve member 82a moves to abut against the second valve seat 76a and shuts off the connecting portion 90a provided on the cylinder wall as shown in FIG. The communication with the compressed gas source 60 is cut off. In this position, the aperture point 80a does not operate.

  At the end of the expansion phase, a feed pressure is established in the cylinder chamber 52. The oil accumulated in the cylinder chamber 52 then flows out into the valve space 94 through the throttle point 80a. During the next compression operation, the oil flowing out is ejected by the air that is pushed away into the valve space 94 and flows out to the oil separation outlet 88a formed in the bottom 98 of the closing part 74a. A connection 90a for compressed air is arranged in the cylinder wall 100 at a distance from the bottom of the closure, thus preventing further backflow of oil.

  7a, 7b, and 7c are shown for a fine speed of 800 revolutions per minute (FIG. 7a), a partial load of 1000 revolutions per minute (FIG. 7b), and a full load of 4000 revolutions per minute ( Fig. 7c shows the pressure and piston profile over two duty cycles of the return device according to the invention of Fig. 7c).

  For example, at a fine speed or operating speed of 800 revolutions per minute (FIG. 7a), continuous pressure compensation is performed through the throttle point of the valve member, so that the cylinder pressure PK communicates between the cylinder chamber and the compressed gas source. Since the switching pressure PS required for shut-off is reached, the pressure PK in the cylinder chamber is always on the order of the feed pressure PD. As a result, the motor load generated for pneumatic drive is low and the motor can be operated quietly, in particular the drive can be switched off and the thread control device can be moved manually, for example for setting and repair purposes.

  At a partial load of 1000 revolutions per minute (FIG. 7b), the cylinder chamber pressure PK reaches the required switching pressure PS during the cycle, and then the valve is disconnected from the compressed gas source and closed. Start compression in the cylinder chamber. The compression of the cylinder chamber reaches its maximum value at the bottom dead center UT. During the subsequent expansion, the cylinder chamber pressure PK again drops below the switching pressure PS. The cylinder chamber is then connected again to the compressed gas source and when the top dead center OT of the piston is reached, the feed pressure PD is established again in the cylinder chamber. The compression pressure in the cylinder chamber prevents the rollers from coming off the positive drive eccentrics at higher operating speeds.

  At the full load condition of 4000 times per minute, the required switching pressure PS is reached faster than at the lower operating speed (FIG. 7c). The compression is thus performed over a larger stroke, so that the maximum compression pressure reaches a higher value than at lower operating speeds. During the subsequent expansion, the required switching pressure PS is reached again, so that the valve regains communication with the compressed gas source in the cylinder chamber. Maximum compression pressure is a direct function of machine speed, in other words, at higher speeds, the maximum compression pressure also increases. This is advantageous for both the efficient operation of the machine and the satisfactory function of the positive drive.

  When the valve is opened every work cycle, the lubricating oil accumulated in the cylinder chamber is continuously discharged. Therefore, reliable continuous operation of the factory is possible without a maintenance cycle for removing the lubricating oil from the cylinder chamber. The valve tasks and requirements described above can be performed independently, in other words, without being activated externally. Sizing the spring force, throttle cross section, and valve member outer diameter or valve seat diameter provides an independent control function of the valve.

  Thus, the return device described herein for the yarn control device independently satisfies the most diverse requirements while at the same time having the lowest possible expense from a technical point of view. The return device can therefore be produced particularly cost-effectively and, due to its simple structure, is almost maintenance-free and does not fail during operation.

  The yarn control device according to the invention can also be used, for example, for individual yarn control for a jacquard loom and for introducing individual weft yarns in a weft device.

It is the side view which showed the needle type ribbon loom. It is the figure which showed the collar frame apparatus which has a pneumatic type return device seen in the direction orthogonal to the running direction of warp. It is the figure which expanded and showed the pneumatic return apparatus shown in FIG. 2 in detail in the basic position. It is the figure which showed the pneumatic return apparatus shown in FIG. 3 in the compression position. FIG. 6 is a more enlarged view of a further exemplary embodiment of a pneumatic return device. It is the figure which showed the pneumatic return apparatus shown in FIG. 5 in the compression position. It is the figure which showed the pressure at the time of fine speed and the profile of a piston of the pneumatic return device concerning the present invention. It is the figure which showed the pressure and the profile of the piston of the pneumatic return apparatus of a partial load state. It is the figure which showed the pressure and piston profile of the pneumatic return apparatus of a full load state.

Explanation of symbols

2 Machine 4 Main drive shaft 6 Weft thread needle 7 筬 8 Cloth take-up device 10 綜 絖 Frame device 12 Warp beam stand 14 Warp beam 16 Warp yarn 18 Reed 20 Yarn supply device 22 Yarn bobbin 24 Weft yarn 26 Tack yarn 28 Yarn supply device 30 綜 絖Frame 31 Thread guide member 32 Connecting rod 34 Cam drive device 35 Reliable drive device 36 Return device 38 Rotating lever 40 Drive point 42 Cam 44 Cam shaft 46 Output point 48 Joint 50 Pivot shaft 52 Cylinder chamber 54 Piston 56 Valve 56a Valve 58 Feed Pressure chamber 60 Compressed gas source 64 Cylinder 66 Top dead center 68 Bottom dead center 70 Housing 71 Stopper 72 First valve seat 72a First valve seat 74 Closed portion 74a Closed portion 76 Second valve seat 76a Second valve seat 78 Flow path Duct 80 Restriction point 80a Restriction point 82 Valve member 82a Valve member 84 Spring 84a Spring 86 Part 88 outlet 88a outlet 90 connecting section 90a connecting section 92 the wall 94 valve space 96 sleeve portion 98 bottom 100 wall

Claims (19)

  Comprising at least one thread guide member (31) movable in one direction of movement by a positively designed drive device (35) and in the opposite direction by a return device (36) designed in a non-reliable pneumatic manner; The apparatus comprises a cylinder / piston assembly (64, 54), the cylinder chamber (52) of said cylinder / piston assembly being connected to a compressed gas source (60) via a valve (56, 56a). In a yarn control device for a textile machine, particularly for an opening device, the valves (56, 56a) include a first valve seat (72, 72a) connected to the cylinder chamber (52) and a second valve seat (76). 76a), between which the valve member (82, 82a) with at least one throttle point (80, 80a) is movable, said valve member being in its basic position with a spring (84, 84a) ) When the first valve seat (72, 72a) is pressed and the valve member (82, 82a) is pressed against the second valve seat (76, 76a), the throttle point (80, 80a) Does not operate, and the valve member (82, 82a) blocks communication with the compressed gas source (60).   The yarn control device according to claim 1, wherein the valve has a housing (70), and a first valve seat (72) is formed at one end thereof.   3. The yarn control device according to claim 2, wherein the second valve seat (76) is formed in a closure (74) designed to have a flow duct (78).   4. The housing according to claim 2, wherein the housing is designed in a cylindrical shape, in which a piston-like valve member is guided in a sealed manner with respect to the wall of the housing. The yarn control device according to claim 1.   4. The yarn control device according to claim 2, wherein a gap between the valve member (82) of the valve (56) and the housing wall serves as a throttle point.   The yarn control device according to any one of claims 1 to 5, wherein the valve (56, 56a) is disposed in the cylinder chamber (52).   The yarn control device according to any one of claims 1 to 6, wherein the valve (56, 56a) is disposed at a lowest point of the cylinder (64).   The yarn control device according to any of the preceding claims, characterized in that the closure (74) of the valve (56) is connected directly to a feed pressure chamber (58).   9. The yarn control device according to claim 8, wherein the feed pressure chamber (58) has an oil separation outlet (88) for oil exiting the cylinder chamber (52).   10. The yarn control device according to claim 9, wherein the oil separation outlet (88) is arranged at the bottom (86) of the feed pressure chamber (58).   A connection (90) for compressed air is arranged on the side wall (92) of the feed pressure chamber at a distance from the bottom (86) of the feed pressure chamber (58). The yarn control device described in 1.   12. The yarn control device according to claim 8, wherein the feed pressure chamber (58) of at least one return device (36) serves as a feed pressure and oil spill device.   The yarn control device according to claim 1, wherein a lower part of the cylinder (64) serves as a valve housing and has a connection (90a) for the compressed gas source (60).   14. An annular stopper (71) is arranged inside the cylinder (64) and is designed as a first valve seat (72a) connected to the cylinder chamber (52). Yarn control device.   The cylinder (64) is closed by the closing part (74a), the closing part has a sleeve part (96), and the free end of the sleeve part serves as a second valve seat (76a). The yarn control device according to claim 14.   16. The yarn control device according to claim 15, wherein an oil separation outlet (88a) is arranged in the closing part (74a).   The yarn control device according to claim 1, characterized in that the switching pressure (PS) of the valve (56, 56a) can be set by a change in the prestressing force of the spring (84, 84a).   18. The yarn control device according to claim 17, wherein the prestressing force of the spring (84, 84a) can be set from the outside.   The yarn control device according to claim 1, characterized in that the maximum compression pressure (PK) of the cylinder chamber (52) can be set by the flow cross section of the throttle point (80, 80a).

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