JP3385747B2 - Threading device in jet loom - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a threading device in a jet loom which conveys a weft passed through a weft conveying nozzle by a jet action of the weft conveying nozzle. 2. Description of the Related Art As disclosed in Japanese Patent Application Laid-Open No. 3-185156, when a weft is passed through a weft carrying nozzle, the weft carrying nozzle is jetted to generate a suction air flow at an inlet thereof. The weft leading end is drawn into the weft conveying nozzle by the suction air flow. [0003] The weft conveying nozzle includes a cylindrical nozzle body, a thread guide inserted into the nozzle body, and an accelerating tube connected to the nozzle body. The insertion amount of the thread guide into the nozzle body is adjusted by changing the screwing position of the thread guide into the nozzle body. The needle-shaped tip of the thread guide enters the cylinder of the nozzle body, and compressed air is supplied from the side surface of the nozzle body to between the tip of the thread guide and the inner peripheral surface of the nozzle body. The compressed air supplied into the nozzle body travels to the accelerating tube along the outer peripheral surface of the thread guide tip. The air flow toward the acceleration tube along the outer peripheral surface of the thread guide tip generates a suction air flow at the entrance of the thread guide. [0004] In order to increase the suction force at the entrance of the thread guide, it is only necessary to make it difficult for the compressed air supplied into the nozzle body to enter the thread guide from the tip of the thread guide. . For this purpose, the passing cross-sectional area between the outer peripheral surface of the needle-shaped tip of the thread guide and the inner peripheral surface of the nozzle body may be reduced. However, if the passage cross section is reduced, the passage resistance increases, and the pressure loss with respect to the compressed air in the nozzle body increases. An increase in pressure loss in the nozzle body leads to a decrease in the weft driving force, and weft insertion errors increase in the weft insertion main nozzle for inserting the weft. [0005] It is an object of the present invention to provide a threading device which can reliably thread a weft conveying nozzle without lowering the weft driving force. [0006] In SUMMARY OF to the invention of claim 1 for the compression air and compressed air supply passage in the weft conveying nozzle
Equipped with a suction port that generates a suction flow by supplying air
A suction flow generator and a supply of compressed air to the suction flow generator;
It is interposed on the supply pipe,
A first switching valve that is switched to
Interposed on the suction pipe connected to the
The shut-off state and the communication state are linked with the first switching valve.
And a negative pressure generator having a second switching valve that is switched to a suction pipe, and a suction air flow from the compressed air supply passage toward the suction pipe is generated by the operation of the negative pressure generator. did. According to the first aspect of the present invention, the suction air flow is generated in the weft conveying nozzle by the operation of the negative pressure generating device. At least a part of the suction air flow is the air flowing in from the inlet of the weft conveying nozzle. If the suction force by the operation of the negative pressure generator is increased, the leading end of the weft is reliably drawn into the weft transport nozzle. Since the suction force due to the operation of the negative pressure generating device is not related to the weft driving force, both reliable weft threading and proper weft driving force are achieved. Also, the first cut
The switching valve is switched from the shut-off state to the communicating state
And the second switching valve is also switched from the shut-off state to the communicating state.
Be replaced. Therefore, the suction power of the suction flow generator is
Acts on the weft transfer nozzle through the pipe to enable threading
It becomes. The presence of the second switching valve indicates that the suction
Prevents air leakage from the pull pipe. FIG. 1 shows a first embodiment of the present invention.
A description will be given based on FIG. 1 is the weft conveying nozzle 1
The weft insertion main nozzle 1 ejects the weft Y into the warp shedding by the injection of the weft insertion main nozzle 1. 2 is an air supply tank for weft insertion. The air supply tank 2 is connected to a source pressure tank (not shown) via a pressure reducing valve 3. The pressure in the air supply tank 2 is regulated by a pressure reducing valve 3. Main nozzle 1 for weft insertion
Is connected to the air supply tank 2 via a supply pipe 4 and an electromagnetic switching valve 5. A breeze pipe 6 is connected to a supply pipe 4 between the electromagnetic on-off valve 5 and the weft insertion main nozzle 1. A check valve 7 and a pressure reducing valve 8 are interposed on the breeze pipe 6. The breeze pipe 6 is connected to the source pressure tank. The weft insertion main nozzle 1 includes a cylindrical nozzle body 9, a thread guide 10 screwed into the cylinder of the nozzle body 9, a lock nut 11 screwed to the thread guide 10, An acceleration tube 12 is connected to the body 9. The supply pipe 4 is connected to a supply port 9-1 on the side of the nozzle body 9. The compressed air supplied from the supply pipe 4 is supplied to the compressed air supply passage 13 between the inner peripheral surface of the nozzle body 9 and the outer peripheral surface of the thread guide 10.
Toward the acceleration tube 12. A suction port 9-2 is formed on the side of the nozzle body 9 corresponding to the vicinity of the tip 10-1 of the needle-shaped thread guide 10. The suction port 9-2 and the suction flow generator 14 are connected by a suction pipe 15. The suction flow generator 14 includes a nozzle portion 14-1 and a cylindrical diffuser 14-2. The nozzle portion 14-1 and the first switching valve 16 are connected by a supply pipe 17. The first switching valve 16 is manually switched between a shut-off state shown in FIG. 1 and a communication state shown in FIG. The first switching valve 16 is connected to the source pressure tank. A suction port 14-3 is formed on a side surface of the diffuser 14-2. The compressed air supplied to the nozzle 14-1 is injected from the outlet of the diffuser 14-2, and a negative pressure is generated at the suction port 14-3. The suction port 14-3 and the suction port 9-2 are connected by a suction pipe 15, and a second switching valve 18 is interposed on the suction pipe 15. The second switching valve 18 includes the pressure action chamber 1
8-1. The pressure action chamber 18-1 is connected to the supply pipe 17 via the pressure introduction pipe 19. When the compressed air is supplied to the pressure action chamber 18-1, the second switching valve 18 enters the communication state shown in FIG. When the compressed air in the pressure action chamber 18-1 is discharged, the second switching valve 18
Is in the cutoff state shown in FIG. To pass the weft yarn Y through the weft insertion main nozzle 1, the leading end of the weft yarn Y is brought close to the entrance 10-2 of the thread guide 10, and the first switching valve 16 is switched from the shut-off state to the communicating state. When the first switching valve 16 is switched from the shut-off state to the communicating state, compressed air is supplied to the suction flow generator 14, and a negative pressure is generated at the suction port 14-3. The compressed air is supplied to the pressure working chamber 18-1 via the supply pipe 17 and the pressure introducing pipe 19. By this pressure supply, the second switching valve 18 is switched from the shut-off state to the communicating state. That is, the second switching valve 18 is linked with the switching of the first switching valve 16 from the shut-off state to the communication state. The suction port 14-3 of the suction flow generator 14 communicates with the suction port 9-2 of the main nozzle 1 for weft insertion.
A suction flow toward 4 is generated. As a result, a suction flow is generated at the entrance 10-2 of the thread guide 10, and the leading end of the weft Y is drawn into the thread guide 10 by the suction flow. After inserting the leading end of the weft yarn Y such that the leading end of the weft yarn Y reaches the inside of the accelerating tube 12, the first switching valve 16 is switched from the communicating state to the blocking state. Then, the supply of the compressed air to the second switching valve 18 is stopped, and the second switching valve 18 is also switched from the communication state to the cutoff state. That is, the second switching valve 18 operates in conjunction with the operation of the first switching valve 16. And
A low-pressure air flow supplied from the breeze pipe 6 to the weft insertion main nozzle 1 passes the leading end of the weft Y through the acceleration tube 12.
In this way, threading to the weft insertion main nozzle 1 is performed. If the second switching valve 18 is in the shut-off state, the compressed air supplied to the compressed air supply passage 13 in the nozzle body 9 does not flow out through the suction port 9-2 to the outside, which hinders weft insertion. Never come. The compressed air supplied to the suction flow generator 14 is used exclusively for threading, and the weft insertion air supplied from the supply pipe 4 to the weft insertion main nozzle 1 is used exclusively for weft insertion. It has nothing to do with threading. The compressed air supply passage 1 between the outer peripheral surface of the needle-shaped tip 10-1 of the thread guide 10 and the inner peripheral surface of the nozzle body 9 in order to increase the suction force at the inlet 10-2 of the thread guide 10.
It is not necessary to make the cross-sectional area of 3 smaller. That is, the passing cross-sectional area can be set so as to provide a weft driving force for optimal weft insertion, and the threading to the weft insertion main nozzle 1 can be reliably performed. The main nozzle 1 for weft insertion from the supply pipe 4
Conventionally, when weft insertion air supplied to a thread guide is used for threading, increasing the length of the accelerating pipe increases the resistance of the pipeline, weakens the negative pressure at the entrance of the thread guide, and makes threading difficult. However, in this embodiment in which the weft insertion air supplied from the supply pipe 4 to the weft insertion main nozzle 1 is not related to threading, the acceleration tube 12 can be increased regardless of threading, and the weft driving force is increased. be able to. Conventionally, the mounting position of the thread guide 10 with respect to the nozzle body 9 is adjusted so that threading can be performed through the weft insertion main nozzle 1, and weft insertion air is injected from the weft insertion main nozzle 1. Therefore, it was necessary to check the state of negative pressure generation at the entrance 10-2 of the thread guide 10 using a dedicated device. However, in this embodiment, since the weft insertion air is not related to the threading, it is not necessary to adjust the mounting position of the thread guide 10 with respect to the nozzle body 9 for the threading. This device becomes unnecessary. Further, the structure using the suction flow generator 14 and the switching valves 16 and 18 has a simple mechanism and is inexpensive. Next, the embodiment of FIG. 3 will be described. The negative pressure generator of this embodiment includes a blower 20, a switching valve 21, and a suction pipe 22. Other configurations are the same as those of the first embodiment. If the blower 20 is operated while the switching valve 21 is in the communicating state, the entrance 10-2 of the thread guide 10
A suction flow is generated. The blower 20 generates a stronger suction flow than the suction flow generator 14, and threading is easy. As shown in FIG. 4, a limit switch 23 serving as a switch of the blower 20 may be attached to the switching valve 21, and the limit switch 23 may be turned on when the switching valve 21 is switched from the shut-off state to the communicating state. . This makes it easy to operate the blower 20 when the switching valve 21 is in the communicating state. A suction pipe 15 is connected to the supply pipe 4 between the weft insertion main nozzle 1 and the solenoid on-off valve 5,
The negative pressure of the suction flow generator 14 may be applied to the supply port 9-1. Next, the embodiment of FIG. 5 will be described. In this embodiment, a tandem nozzle 24 is installed behind the weft insertion main nozzle 1. The tandem nozzle 24 assists the conveyance of the weft Y inserted by the weft insertion main nozzle 1. The supply port 25-1 of the nozzle body 25 of the tandem nozzle 24 is connected to the air supply tank 2 via a supply pipe 26 and an electromagnetic valve 27. Nozzle body 2
The structure of the compressed air supply passage between the nozzle 5 and the thread guide 28 is the same as that of the main nozzle 1 for weft insertion. At the tip of the acceleration tube 29 of the tandem nozzle 24, a suction hollow ring 30 is fixed. The inner peripheral wall 30-1 of the hollow ring 30 is made of a permeable sintered metal.
The inner peripheral wall 30-1 is also a part of the acceleration tube 29. The hollow ring 30 is connected to a suction flow generator 33 via a suction pipe 31 and a second switching valve 32. The suction flow generator 33 is connected to a source pressure tank (not shown) via a supply pipe 34 and a first switching valve 35. The negative pressure generator for the weft insertion main nozzle 1 is the same as in the first embodiment. When the first switching valve 35 is brought into the communicating state, the second switching valve 32 is also brought into the communicating state, and the negative pressure generated at the suction port 33-1 of the suction flow generator 33 spreads into the hollow ring 30. Accordingly, a suction flow is generated from the inside of the acceleration tube 29 to the inside of the hollow ring 30 through the inner peripheral wall 30-1. Can be As shown in FIG. 6, an embodiment is also possible in which a shutter 36 is slidably mounted on the hollow ring 30 and the switching valve 37 is switched between a closed state and a communicating state by a sliding operation of the shutter 36. . The shutter 36 has an opening 36-1 formed therein. When the opening 36-1 is overlapped with the opening of the central hole of the hollow ring 30, the valve body 37-1 of the switching valve 37 is connected to the valve hole 37-. Block 2 If the shutter 36 is moved down, the entrance 36
The overlap between -1 and the opening of the central hole of the hollow ring 30 is released, and the central hole of the hollow ring 30 is closed by the shutter 36. Further, the shutter 36 pushes down the valve body 37-1, and the valve hole 37-2 opens. In this state, the negative pressure of the suction port 33-1 of the suction flow generator 33 spreads into the hollow ring 30, and a suction flow from the acceleration tube 29 to the inside of the hollow ring 30 is generated. Since the shutter 36 closes the opening of the central hole of the hollow ring 30, the suction force at the entrance 28-1 of the thread guide 28 is stronger than in the embodiment of FIG. The inventions other than those described in the claims which can be understood from the above embodiments will be described below together with their effects. (1) A threading device in a jet loom in which a compressed air supply passage in a weft conveying nozzle and a blower are connected by a suction pipe, and a switching valve is interposed on the suction pipe. Threading can be performed with a strong suction force. (2) The compressed air supply passage in the weft conveying nozzle and the blower are connected by a suction pipe, a switching valve is interposed on the suction pipe, and a switch for operating the blower when the switching valve is in a communicating state is provided. A threading device in a jet loom linked to a switching valve. The operation for threading becomes easy. As described above in detail, according to the first aspect of the present invention, the compressed air supply passage in the weft conveying nozzle and the negative pressure generator are connected by a suction pipe, and the operation of the negative pressure generator is performed. Since the suction air flow from the compressed air supply passage toward the suction pipe is generated, the threading to the weft conveying nozzle can be reliably performed without lowering the weft driving force. In addition, it can be switched between the cutoff state and the communication state
The second switching valve is linked to the first switching valve.
And the negative pressure of the suction flow generator was spread into the nozzle,
Reliable weft threading and proper weft threading with a simple and inexpensive configuration
All progress is achieved. [0030]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a first embodiment of the present invention. FIG. 2 is a sectional view showing a first switching valve in a communicating state. FIG. 3 is a sectional view showing another example. FIG. 4 is a cross-sectional view showing another example. FIG. 5 is a sectional view showing another example. FIG. 6 is a sectional view showing another example. [Description of Signs] 1 ... Main nozzle for weft insertion, which is a weft conveying nozzle, 1
3: compressed air supply passage, 14, 33: suction flow generator, 1
5, 22, 31 ... suction pipe, 16, 35 ... first switching valve, 18, 32 ... second switching valve.

Claims (1)

(57) in jet looms the Patent Claims 1. A weft passed through the weft conveying nozzle is carried by the injection action of the weft conveying nozzle, compressed air and the compressed air supply passage of the yarn transfer nozzle
Suction with suction port that generates suction flow by supply
Flow generator and a supply path for supplying compressed air to the suction flow generator.
Between the shut-off state and the communication state.
A first switching valve to be replaced and the suction port
Interposed on the suction pipe connected to the
Interlocked with the switching valve of No. 1 to turn off and on
A jet connected to a negative pressure generator having a second switchable valve by a suction pipe, and generating a suction air flow from the compressed air supply passage toward the suction pipe by operating the negative pressure generator. Threading device in the room.