EP3165646A2

EP3165646A2 - Weft measurement device for loom

Info

Publication number: EP3165646A2
Application number: EP16196393.9A
Authority: EP
Inventors: Masataka Hamaguchi; Takahiro Inamura; Carsten Meder
Original assignee: Uster Technologies AG; Toyota Industries Corp
Current assignee: Uster Technologies AG; Toyota Industries Corp
Priority date: 2015-11-06
Filing date: 2016-10-28
Publication date: 2017-05-10
Anticipated expiration: 2036-10-28
Also published as: JP6374369B2; EP3165646A3; CN106929984A; CN106929984B; JP2017089026A; EP3165646B1; BR102016025391A2

Abstract

A weft measurement device for a loom is configured to measure a parameter of a weft yarn (Y) drawn from a yarn feeding unit (2) and weft-inserted by a weft inserting nozzle (8). The weft measurement device includes a weft sensor (30) including a weft measuring portion (34) and a weft guide unit (31) that guides the weft yarn (Y) to the weft measuring portion (34). The weft guide unit (31) includes a moving means (38) that moves the weft yarn (Y) to a non-measurement position that is separated from a measurement position in the weft measuring portion (34). The non-measurement position is set at a position separated sideways from a vertical plane (A) including the measurement position in the weft measuring portion (34).

Description

BACKGROUND OF THE INVENTION

The present invention relates to a weft measurement device for a loom that measures a parameter of a weft yarn fed to a loom for weft insertion.
For example, in an air-jet loom, a weft yarn is fed from a yarn feeding unit to a weft inserting nozzle. Even when the weft yarn is fed from the same yarn feeding bobbin, parameters of the weft yarn, such as the thickness or mass, change in long cycles.
Japanese National Phase Laid-Open Patent Publication No. 2014-522920 discloses an example of an air-jet loom including a yarn sensor located between a weft bobbin and a weft storing device to continuously measure parameters such as the mass, the diameter, and hairiness of the weft yarn or foreign matter included in the weft yarn. A controller calculates the optimal nozzle opening time, including the air efficiency, for an accelerating nozzle (weft inserting nozzle) and a relay nozzle (auxiliary nozzle) based on the parameters measured by the yarn sensor.
The yarn sensor includes a measurement region formed by a measurement slot that allows for the passage of a weft yarn. The measurement slot opens at the upper side. A support including a weft yarn guide is arranged on each of the two sides of the measurement slot in the direction the weft yarn travels. The weft yarn is held by the guides when passing through the measurement slot. The support of the guides is coupled to a moving means, which includes an air cylinder, and moved in the vertical direction when the air cylinder is actuated.
When the air cylinder is not actuated during operation of the air-jet loom, the guides are located at a lowered position to guide the weft yarn so that the weft yarn passes through the measurement slot of the yarn sensor. When the weft yarn passes through the measurement slot, the yarn sensor measures the parameters of the weft yarn. When the air cylinder is actuated, the support moves the guides toward the upper side. Thus, the weft yarn is separated from the measurement slot and passes a region located above the measurement slot. When the guides are moved to the upper side and the weft yarn is separated from the measurement slot, the yarn sensor performs a measurement without the weft yarn. This zero-balances the sensor. The zero balancing refers to a task in which a reference level for measuring the parameters of the weft yarn is reset. Thus, the zero balancing will hereinafter be referred to as the "reference level setting task."
A weft yarn drawn from a weft bobbin is held by a weft tensioner located in the vicinity of the weft bobbin. The weft tensioner includes two leaf springs that apply a predetermined tension to the weft yarn. When fly accumulates between the leaf springs or a holding force adjusting component of the weft tensioner, the force of the weft tensioner may decrease and the weft yarn may become loose.
In the yarn sensor, the weft yarn is lifted above the measurement slot by the guides when the reference level setting task is performed. Thus, when the weft yarn is loose, the weft yarn between the two guides droops into the measurement slot. The drooping weft yarn may be measured by the yarn sensor. When the drooping weft yarn is measured by the yarn sensor, the reference level setting task is hindered. When the reference level is set incorrectly, the measured data of the parameters of the weft yarn may include an error. This may result in the execution of inaccurate weft insertion control.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a weft measurement device for a loom that obviates reference level setting failures of a weft sensor that may be caused by a loose weft yarn when a parameter of the weft yarn is not to be measured.
One aspect of the present invention provides a weft measurement device for a loom. The weft measurement device measures a parameter of a weft yarn drawn from a yarn feeding unit and weft-inserted by a weft inserting nozzle. The weft measurement device includes a weft sensor including a weft measuring portion and a weft guide unit that guides the weft yarn to the weft measuring portion. The weft guide unit includes a moving means that moves the weft yarn to a non-measurement position that is separated from a measurement position in the weft measuring portion. The non-measurement position is set at a position separated sideways from a vertical plane including the measurement position in the weft measuring portion.
Said vertical plane is preferably defined by a longitudinal axis of the weft yarn in the measurement position and by a depth direction of a measurement slot included in the weft measuring portion.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic view showing an air-jet loom including a first embodiment of a weft measurement device.
Fig. 2 is a perspective view showing the weft measurement device.
Fig. 3 is a front view showing the weft measurement device.
Fig. 4 is a diagram showing a weft guiding portion located at a measurement position.
Fig. 5 is a diagram showing the weft guiding portion located at a non-measurement position.
Fig. 6 is a schematic view showing a weft guiding portion in a second embodiment.

EMBODIMENTS OF THE INVENTION

First Embodiment

A first embodiment of a weft measurement device for a loom will now be described with reference to Figs. 1 to 5. In this specification, the upper side as viewed in Fig. 1 is the upper side of an air-jet loom 1, and a weft yarn travels toward a downstream side from an upstream side. Fig. 1 shows the structure related to weft insertion of the air-jet loom 1.
A yarn feeding unit 2 is arranged on a bracket (not shown) fixed to a frame (not shown) or a floor surface (not shown) beside the air-jet loom 1. A weft tensioner 3, a weft measurement device 4, a weft length measuring and storing device 5, and a tandem nozzle 6 are sequentially arranged toward the downstream side of a weft yarn Y that is drawn from the yarn feeding unit 2. A weft inserting nozzle 8, a modified reed 10, which includes a weft guiding passage 9, and auxiliary nozzles 11 are arranged on a sley 7 at the downstream side of the tandem nozzle 6.
The yarn feeding unit 2 includes a weft bobbin around which the weft yarn Y is wound. The weft tensioner 3 includes two leaf springs located at opposite sides of the weft yarn Y. The weft yarn Y is held between the leaf springs by the pressure of the leaf springs. This applies tension to the weft yarn Y that is drawn toward the weft length measuring and storing device 5.
The weft length measuring and storing device 5 includes a rotary yarn guide 13, a weft locking pin 14, and a balloon sensor 15. The yarn guide 13 is configured to wind the weft yarn Y, which is drawn via the weft measurement device 4 (described below), around a still storage drum 12. The weft locking pin 14 is configured to lock the weft yarn Y wound around the storage drum 12. The balloon sensor 15 is configured to detect the amount of the weft yarn Y drawn out of the storage drum 12.
The weft locking pin 14 includes a drive unit formed by a solenoid. When the solenoid is activated, the weft locking pin 14 is projected toward the storage drum 12 to lock the weft yarn Y. When the solenoid is deactivated, the weft locking pin 14 is separated from the storage drum 12 to release the weft yarn Y. The balloon sensor 15 is formed by a photoelectric sensor. The balloon sensor 15 counts the ballooning frequency of the weft yarn Y drawn by the tandem nozzle 6 and the weft inserting nozzle 8 during weft insertion. When the balloon sensor 15 counts a set balloon frequency, the solenoid of the weft locking pin 14 is activated by an instruction signal from a controller 24 (described below). This locks the weft yarn Y.
The tandem nozzle 6 and the weft inserting nozzle 8 are configured to eject compressed air in order to draw the weft yarn Y from the storage drum 12 and insert the drawn weft yarn Y into the weft guiding passage 9 of the modified reed 10, which is located in a warp shed (not shown). The auxiliary nozzles 11 are configured to eject compressed air that carries the inserted weft yarn Y along the weft guiding passage 9.
A tandem air valve 16 connected to the tandem nozzle 6 and a main air valve 17 connected to the weft inserting nozzle 8 are connected to a common main air tank 18. The main air tank 18 is connected to a compressed air source (not shown) such as a compressor via a main regulator 19 by a pipe 20. The auxiliary nozzles 11 are connected to one of a group of auxiliary air valves 21. The auxiliary air valve 21 is connected to the pipe 20 via an auxiliary air tank 22 and an auxiliary regulator 23.
The weft locking pin 14 and the balloon sensor 15 of the weft length measuring and storing device 5, the tandem air valve 16, the main air valve 17, and the auxiliary air valve 21 are electrically connected to the controller 24 by wires 25, 26, 27, 28, and 29, respectively.
The controller 24 issues an instruction signal that opens the tandem air valve 16 and the main air valve 17 to eject compressed air from the tandem nozzle 6 and the weft inserting nozzle 8. When the weft locking pin 14 is operated to release the weft yarn Y, weft insertion is started. When weft insertion is started, the auxiliary air valve 21 opens and the auxiliary nozzles 11 eject compressed air. The weft yarn Y is fed through the weft guiding passage 9 by the compressed air ejected from the auxiliary nozzles 11.
When a set time elapses from when weft insertion is started, the controller 24 issues an instruction to close the tandem air valve 16 and the main air valve 17 and stop ejecting compressed air from the tandem nozzle 6 and the weft inserting nozzle 8. The balloon sensor 15 counts the ballooning frequency of the weft yarn Y drawn from the storage drum 12. When the balloon sensor 15 counts the set ballooning frequency, the controller 24 issues an instruction to actuate the weft locking pin 14 so that the weft locking pin 14 locks the weft yarn Y and terminates weft insertion. Further, the controller 24 issues an instruction to close the auxiliary air valve 21 and stop ejecting compressed air from the auxiliary nozzles 11.
The weft measurement device 4 is located between the weft tensioner 3 and the weft length measuring and storing device 5. As shown in Figs. 2 and 3, the weft measurement device 4 includes a weft sensor 30 and a weft guide unit 31. The weft sensor 30 includes a housing 32. One side of the housing 32 is cut in a U-shaped manner to form a weft measuring portion 34 including a measurement slot 33.
When the housing 32 is arranged between the weft tensioner 3 and the weft length measuring and storing device 5, the measurement slot 33 extends in the vertical direction toward the upper side of the air-jet loom 1 and opens toward the outside. This allows the weft yarn Y to be inserted into the measurement slot 33 from the upper side. A photoelectric sensor, a capacitive sensor and/or any other sensor are incorporated in the housing 32 to form the weft sensor 30. The weft sensor 30 is electrically connected to the controller 24 by a wire 35. The weft sensor 30 measures one or more parameters of the weft yarn Y inserted into the measurement slot 33 of the weft measuring portion 34, such as the thickness, mass, density, hairiness, and foreign matter. Then, the weft sensor 30 transmits the measured parameters to the controller 24.
The weft guide unit 31 includes weft guides 36 and 37 located at the two ends with respect to the travel direction of the weft yarn Y. The weft measuring portion 34 is located between the weft guides 36 and 37. The weft guide unit 31 also includes a moving means 38 for the weft guides 36 and 37 and a stopper 39 that restricts movement of the weft guides 36 and 37. The weft guide 36 is supported by a support arm 41 (refer to Fig. 3) and includes a U-shaped holding groove 40, which opens toward the upper side. The weft guide 37 is shaped in the same manner as the weft guide 36 and includes a U-shaped holding groove 42 and a support arm 43.
The moving means 38 includes a body 44 incorporating a rotary solenoid and is electrically connected to the controller 24 by a wire 45. The body 44 is fixed to a bracket 47 that is fastened to the housing 32 of the weft sensor 30 by bolts 46 (refer to Fig. 3). The basal ends of the support arms 41 and 43 of the weft guide unit 31 are fixed to the two ends of a rotation shaft 48, which project from the two opposite sides of the rotary solenoid.
Thus, when the controller 24 issues an instruction to rotate the rotary solenoid, the moving means 38 moves the weft yarn Y, which is held in the holding grooves 40 and 42 of the weft guides 36 and 37, in an arcuate manner between a measurement position (position shown by solid line in Fig. 3) and a non-measurement position (position shown by broken line in Fig. 3) that is separated from the measurement position.
The measurement position is set at a position that allows the weft sensor 30 to measure the parameters of the weft yarn Y in the measurement slot 33 of the weft measuring portion 34. Further, the measurement position is set on a vertical plane A in the measurement slot 33. The non-measurement position is set at a position separated from the vertical plane A that includes the measurement position. It is preferred that the arcuate movement path between the measurement position and the non-measurement position be set to minimize contact of the weft yarn Y with the wall surface of the measurement slot 33.
The stopper 39 is cylindrical and includes an outer circumferential surface around which an elastic member 49 is wound. The stopper 39 is fixed to the bracket 47 to project toward the support arm 41 of the weft guide unit 31. As shown in Fig. 3, the stopper 39 restricts rotation of the weft guide 36 toward the lower side from the measurement position shown by the solid line. The stopper 39 also restricts rotation of the weft guide 36 toward the upper side from the non-measurement position shown by the broken line.
The operation of the weft measurement device 4 will now be described with reference to Figs. 4 and 5.
During operation of the air-jet loom 1, the controller 24 issues an instruction to actuate the moving means 38 of the weft guide unit 31. This rotates the support arms 41 and 43 in the counterclockwise direction and moves the weft guides 36 and 37 to the measurement position as shown in Fig. 4. The support arms 41 and 43 stop at the measurement position. The weft yarn Y that is held in the holding grooves 40 and 42 of the weft guides 36 and 37 and inserted into the measurement slot 33 at the measurement position travels toward the weft length measuring and storing device 5.
As the weft yarn Y travels by the measurement position, the parameters of the weft yarn Y such as the thickness are continuously measured by the weft sensor 30. The measured parameters are transmitted from the weft sensor 30 to the controller 24, which stores the parameters. The measured parameters are each analyzed and used as control data for, for example, weft insertion control.
Before measuring the parameters of the weft yarn Y, the weft measurement device 4 performs a reference level setting task that sets a reference level used to measure the parameters. The reference level setting task is performed, for example, when operation of the air-jet loom 1 starts, when the air-jet loom 1 is restarted after being stopped for one reason or another, or for every certain number of operations performed by the air-jet loom 1.
When the reference level setting task is to be performed, the controller 24 issues an instruction that activates the moving means 38 during operation of the air-jet loom 1 to rotate the support arms 41 and 43 of the weft guide unit 31 in the clockwise direction as viewed in Fig. 5. The weft yarn Y is moved to the non-measurement position in an arcuate manner. Thus, the weft yarn Y is moved from the measurement position toward the upper side by distance D1 and removed from the measurement slot 33 of the weft measuring portion 34. Then, the weft yarn Y is moved sideways to the non-measurement position that is separated by distance D2 from the vertical plane A (refer to Fig. 3), which includes the measurement position in the measurement slot 33.
When the weft yarn Y is moved to the non-measurement position Y, the weft sensor 30 measures its sensitivity in the measurement slot 33, from which the weft yarn Y has been removed, and transmits the measured data to the controller 24. The controller 24 sets the reference level of the weft sensor 30 based on the measured data and uses the reference level of the weft sensor 30 to measure the parameters of the weft yarn Y.
If, for example, the holding force of the weft tensioner 3 decreases for one reason or another when the reference level setting task is performed with the weft yarn Y located at the non-measurement position, the tension applied to the weft yarn Y will decrease. The weight of the weft yarn Y may cause the weft yarn Y to droop as shown by weft yarn Y1 in a broken line. However, in the present embodiment, the weft yarn Y is moved to the non-measurement position that is separated sideways by distance D2 from a position located above the measurement slot 33 of the weft measuring portion 34. Thus, the drooping weft yarn Y1 does not droop into the weft measuring portion 34. Accordingly, a setting failure of the reference level does not occur when performing the reference level setting task that measures the sensitivity of the weft sensor 30.
In the present embodiment, when the weft guide unit 31 moves to the non-measurement position and shifts to a state in which the parameters of the weft yarn Y are not measured, even if the weft yarn Y loosens and droops, the weft yarn Y does not move into the weft measuring portion 34. Thus, the weft yarn Y does not interfere with the reference level setting task of the weft sensor 30. Further, since there is no need to take into account the influence of a loose weft yarn, the movement amount of the weft guide unit 31 may be minimized. Reduction in the movement amount of the weft guide unit 31 avoids increases in the tension applied to the weft yarn Y when bending the moving weft yarn Y. This obviates damage and/or breaking of the weft yarn Y.
Further, in the present embodiment, the weft yarn Y is moved in an arcuate manner between the measurement position and the non-measurement position. Thus, the time and amount of the movement between the measurement position and the non-measurement position is smaller than when moving the weft yarn Y separately in the vertical and sideway directions. In addition, the time for the reference level setting task of the parameters of the weft yarn Y may be shortened.
Additionally, the moving means 38 of the weft guide unit 31 is formed by the rotary solenoid. This reduces the size of the moving means 38 and facilitates control of the moving means 38 as compared with when using a servomotor. Further, since the activation time is short, less power is consumed.

Second Embodiment

Fig. 6 shows a second embodiment. In the second embodiment, like or same reference numerals are given to those components that are the same as the corresponding components of the first embodiment. Such components will not be described in detail. In the second embodiment, the weft yarn Y is moved straight between the measurement position and the non-measurement position. The weft sensor 30 of the weft measurement device 4 of the second embodiment has the same structure as that of the first embodiment. A weft guide unit 50 includes a weft guide 51 (only one side of weft measuring portion 34 is shown) and a moving means 52.
The weft guide 51 includes a U-shaped holding groove 53 that opens toward the upper side of the measurement slot 33. The moving means 52 includes an air cylinder 54 and a piston rod 55. The lower end of the weft guide 51 is fixed to an end of the piston rod 55. The weft guide unit 50, which includes the weft guide 51 and the air cylinder 54 and the piston rod 55 of the moving means 52, extends toward an end of the housing 32 inclined relative to the measurement slot 33, which extends in the vertical direction.
The controller 24 issues an instruction to the moving means 52 to activate the air cylinder 54. Activation of the moving means 52 projects the piston rod 55 and moves the weft guide 51 in a direction intersecting the measurement slot 33 between the measurement position shown by the solid line and the non-measurement position shown by the broken line. Thus, the weft yarn Y is moved from the measurement position of the weft yarn Y toward the upper side by distance D3 and removed from the measurement slot 33. Further, the weft yarn Y reaches the non-measurement position that is separated sideways by distance D4 from the vertical plane A including the measurement position.
In the second embodiment, the moving means 52 of the air cylinder 54 moves the weft guide 51 in a direction inclined relative to the measurement slot 33. This allows the non-measurement position of the weft yarn Y to be set at a position separated from above the measurement position. Accordingly, the same advantage as the first embodiment is obtained.
It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the present invention may be embodied in the following forms.

(1) In each of the first and second embodiments, the weft sensor 30 does not have to include the measurement slot 33. Instead, for example, one of the walls of the measurement slot 33 may be omitted at the measurement position, and the omitted portion may open toward the outside.
(2) In the first embodiment, the moving means 38 is not limited to a rotary solenoid and may be a different rotary drive means such as a servomotor.
(3) In the first and second embodiments, the reference level setting task may be performed when the air-jet loom 1 is stopped.
(4) In the second embodiment, a linking mechanism may be arranged between the piston rod 55 of the air cylinder 54 and the weft guide 51 so that the weft guide 51 is moved in an arcuate manner.
(5) In the first and second embodiments, the moving means 38 and the moving means 52 may use an actuator other than a rotary solenoid, a servomotor, and the air cylinder 54. Instead, for example, the movement in the vertical direction and the movement in the intersecting direction may be produced by different moving means.
(6) In the first and second embodiments, the weft measurement device 4 may be located at any position as long as the weft measurement device 4 is located between the yarn feeding unit 2 and the weft inserting nozzle 8 of the air-jet loom 1. Loosening of the weft yarn Y may be caused by reasons other than failure of the weft tensioner 3. Loosening of the weft yarn Y may also occur when the weft measurement device 4 is located at any position between the yarn feeding unit 2 and the weft inserting nozzle 8 of the air-jet loom 1. In the first and second embodiments, setting failures of the reference level of the weft sensor 30 are obviated that would be caused by a loose weft yarn between the yarn feeding unit 2 and the weft inserting nozzle 8 when the parameters of the weft yarn Y are not measured.
(7) The weft tensioner 3 does not have to be formed by leaf springs and may be formed by a tension applying means that includes an elastic body such as a coil spring or a rubber material.
(8) One or both of the weft tensioner 3 and the tandem nozzle 6 may be omitted.
(9) The weft measurement device 4 of the first and second embodiments may be used in various types of looms such as a water-jet loom, a rapier loom, and a gripper loom.

Claims

A weft measurement device for a loom, wherein the weft measurement device is configured to measure a parameter of a weft yarn (Y) drawn from a yarn feeding unit (2) and weft-inserted by a weft inserting nozzle (8), the weft measurement device comprising:
a weft sensor (30) including a weft measuring portion (34), and

a weft guide unit (31; 50) for guiding the weft yarn (Y) to the weft measuring portion (34),
characterized in that
the weft guide unit (31; 50) includes a moving means (38; 52) for moving the weft yarn (Y) to a non-measurement position that is separated from a measurement position in the weft measuring portion (34), and
the non-measurement position is set at a position separated sideways from a vertical plane (A) including the measurement position in the weft measuring portion (34).
The weft measurement device according to claim 1, wherein the moving means (38; 52) is configured to move a weft yarn (Y) in an arcuate manner between the measurement position and the non-measurement position.
The weft measurement device according to claim 1 or 2, wherein the moving means (38; 52) is formed by a rotary solenoid.
The weft measurement device according to any one of claims 1 to 3, further comprising a weft tensioner (3) located at a downstream side of the yarn feeding unit (2), wherein the weft measurement device is located between the weft tensioner (3) and a weft length measuring and storing device (5).