JPS6332902B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for preventing weaving rows (particularly thin rows) at the time of start-up in a loom.

A conventional loom, in particular a warp delivery device, will be explained with reference to FIG. 1 (this figure also shows the device of the present invention). 1 is a warp beam, 2 is a warp, 3 is a back roller The warp yarns 2 pulled out from the warp beam 1 are guided by a warp roller 3, and then guided through heddles and reeds (not shown) to the fabric front.

The back roller 3 has its shaft portion 3a rotatably supported by one end portion of an easing lever 6 whose intermediate portion is fixed to a shaft 5 rotatably supported by a frame 4 of the loom. A pin 7 is protruded from the other end of the easing lever 6, and a support bracket 9 attached to one end of a tension spring 8 is pivotally connected to the pin 7. A support bracket 10 attached to the other end of the tension spring 8 has a tension lever 12 fixed thereto by fitting a square hole 12a into a square shaft of a torsion bar 11.
The tip of a threaded rod 14 rotatably pivoted to a pin 13 protruding from the support bracket 10 is passed through, and a nut 15 screwed onto the threaded rod 14 is engaged with a transparent window 10a formed in the support bracket 10. be. The tension lever 12 is rotatably connected to a piston rod 18 of a piston-type oil damper 17 by a pin 16, and the cylinder case 19 of the oil damper 17 is rotatably supported by a pin 20 protruding from the frame 4.

One end of a rod 22 is rotatably connected to a pin 21 protruding from the tension lever 12, and the other end of the rod 22 is connected to a gear lever 2 of a continuously variable transmission 23.
4 by a pin 25 so as to be rotatable. 22a is a length adjustment mechanism provided at both ends of the rod 22. The continuously variable transmission 23 changes its gear ratio depending on the rotational position of the gear lever 24 (H in the figure is the high speed side, L is the low speed side), and the input shaft (not shown) is connected to the drive motor of the loom. A gear 27 fixed to the output shaft 26 meshes with a gear 29 fixed to one end (outside of the frame 4) of a transmission shaft 28 rotatably supported by the frame 4. A gear (not shown) fixed to the other end (inside the frame 4) meshes with a gear 30 fixed to the side surface of the warp beam 1.

Thus, while visually checking the dial gauge 31 fixed to the frame 4 of the loom, the torsion bar 11
is rotated clockwise in the figure by an amount set according to the type of warp threads 2, etc., and then the tension lever 12 is fitted and fixed as described above to apply a counterclockwise moment to it. The easing lever 6 is biased clockwise via the tension spring 8, and tension is applied to the warp threads 2 via the back roller 3. Here, the tension fluctuation due to the opening and closing of the warp threads 2 is controlled by the easing lever 6 through the back roller 3.
However, it is damped by the tension spring 8 and the oil damper 17, so that the tension lever 12 hardly swings. As the winding diameter of the warp beam 1 decreases as weaving progresses, the delivery speed of the warp threads 2 decreases, the tension of the warp threads 2 increases, and the center line of the easing lever 6 is ) is rotated counterclockwise in the figure, so the tension lever 12 is rotated clockwise via the tension spring 8. As a result, the rod 22 is pushed up, the gear lever 24 of the continuously variable transmission 23 is rotated counterclockwise, the gear ratio (reduction ratio) is decreased, the rotational speed of the warp beam 1 is increased, and the warp threads 2 The tension is corrected.

However, with this type of warp feeding device, even when the loom is stopped during weaving, the stopped state continues until the loom is restarted, so the warp remains under the same tension as during weaving. When left unattended, yarns generally have viscoelasticity, so they may elongate slightly. When this kind of elongation occurs, the fabric moves toward the breast beam, which causes the problem that the first few picks become thin when restarted.

For this reason, in order to increase the tension by artificially compensating for the decrease in tension caused by the elongation of the warp threads during the stoppage, until the tension is recovered at the time of restarting, a predetermined period of time (1
The present applicant has proposed a weaving bar prevention device in which the output rod of an air cylinder is applied to an easing lever to apply special tension to the warp threads (Japanese Patent Application No. 1983). −
79632).

However, with this device, the acting force is removed all at once after a predetermined period of time has elapsed, which causes tension fluctuations, and if the quality of the warp yarns varies and they elongate more than normal, they may be removed for a predetermined period of time. There still remained the problem that the acting force was unwound before the tension returned to normal, resulting in thin steps.

As mentioned above, the purpose of the present invention is to effectively prevent weaving from collapsing at the time of start-up without causing tension fluctuations or being affected by variations in warp quality. and a special tension applying means capable of elastically applying special tension using air, and applying pressurized air to the special tension applying means during preparation for starting the loom or from the time of starting until a predetermined period of at least one revolution has elapsed after starting. A means for applying the tension, a means for gradually reducing the particularly applied tension by reducing the pressure of the pressurized air after the predetermined period has elapsed, and a means for adjusting the reduction of the pressure of the pressurized air. be.

An embodiment of the present invention will be described below based on the drawings.

In FIG. 1, an air cylinder 33 is fixed to a bracket 32 erected on a frame 4 as a special tension imparting means capable of elastically imparting a special tension to the warp yarns using pressurized air, and the output rod 3
An engaging body 35 fixed to the outer end of the easing lever 4 is opposed to the easing lever 6 so as to be able to come into contact therewith. The air cylinder 33 is supplied with pressurized air from a pipe 38 connected to a pressure supply source (not shown) via a pressure regulating valve 37 via an electromagnetic on-off valve 36.

Describing the detailed structure of this air cylinder 33 with reference to FIG. 2, a closing body 62 having an air vent hole 61 is fixed to the lower end of a cylinder case 60, and an output is output to a slide tube 63 attached to this closing body 62. The middle portion of the rod 34 is slidably inserted. A piston 64 is fixed to the inner end of the output rod 34, and the piston 64 is slidably inserted into the cylinder case 60. A compression spring 65 is interposed between the closing body 62 and the piston 64 to urge the piston 64 upward.

An electromagnetic on-off valve 3 is provided at the upper end of the cylinder case 60.
A closing body 66 that also serves as the body of the piston 6 is fixed, and an air chamber 67 is defined between the closing body 66 and the piston 64. The closure body 66 also includes an inlet hole 68 to which the pipe 38 is connected, and a valve chamber 70 communicating with the inlet hole 68 via a through hole 69.
A through hole 71 that communicates this valve chamber 70 and the air chamber 67
The valve chamber 70 side of the through hole 69 serves as a valve seat 72.

The valve body 73 of the electromagnetic on-off valve 36 has a plunger 74 that slidably passes through the closing body 66 and faces the valve chamber 70.
It is attached to the tip of the An electromagnetic solenoid 77 is disposed around the proximal end of the plunger 74 and an iron core 76 that faces the proximal end of the plunger 74 with a compression spring 75 interposed therebetween. A cover 78 is fixed to the iron core 76 with a nut 79.
80 is an air vent hole formed in the iron core 76.

Further, the closing body 66 is provided with means for gradually reducing the specially applied tension. That is, small-diameter discharge holes 81 and 82 are formed that branch from the middle of the through hole 71 and open to the outside, and a throttle valve seat 83 is formed between these. Reference numeral 84 denotes a throttle valve as a pressure reduction adjusting means, which is screwed onto the closing body 66, with its tip facing the throttle valve seat 83, and the amount of discharged air is adjusted by moving it forward and backward. 85 is a spring for preventing loosening. The throttle valve 84 adjusts the pressure in the valve chamber 70 to normal pressure in a period shorter than the period during which special tension is applied to the warp yarns after restarting the loom.

Next, the operating circuit of the electromagnetic on-off valve 36 will be explained with reference to FIG. Auxiliary equipment (blower, etc.) is installed in electric line A.
A normally open automatic return type push button switch 40 for starting, a normally closed contact 46a of a relay 46 to be described later, and a relay 41
are connected in series, and a normally open contact 41a of a relay 41 is connected in parallel to the switch 40. Normally open contact 4 of relay 41 is on circuit B.
1b, a normally closed contact 46b of a relay 46, a normally open automatic return type push button switch 42 for driving the main motor, and a relay 43 are connected in series, and a normally open contact 43a of a relay 43 is connected in parallel to the switch 42. It is connected. A normally open contact 41c of the relay 41, a normally closed contact 46c of the relay 46, an electromagnetic solenoid 77 of the electromagnetic on-off valve 36, and a normally closed contact 52 of an operating circuit 51, which will be described later, are connected in series to the electric circuit C.
A relay 46 and a normally closed contact 44 that opens when a stop circuit 45 (described later) is activated are connected in series to the electric line D. These electric circuits A, B, C, and D are connected in parallel to the power source E.
It is connected to the.

Reference numeral 47 is a rotating shaft that rotates once per rotation of the loom, and an operating piece 48 is fixed to it. Reference numeral 49 denotes a proximity switch, which is disposed close to the rotation path of the operating piece 48 and emits a pulse each time the operating piece 48 approaches. 50 is a counting circuit,
A preset number of pulses is applied to proximity switch 4.
9, it continues to output signals until a reset signal is input from a stop circuit 45, which will be described later. The output side of this counting circuit 50 is connected to an actuating circuit 51. Reference numeral 45 denotes a stop circuit, which is connected to a weft thread detector, a warp thread breakage detector, a selvage thread breakage detector, and a manual stop device (not shown), and is used to detect mispicks, warp thread breaks, and selp thread breaks, or to detect a manual stop device. When actuated, it operates to open the contact 44. This stop circuit 45 is connected to the reset terminal of the counting circuit 50.

Here, the electromagnetic on-off valve 36 and the switch 40 and relay 4 that form the operating circuit of the electromagnetic solenoid 77 are shown.
1. The proximity switch 49, the counting circuit 50, the operating circuit 51, etc. are operated for a predetermined period of at least one revolution after the start of the loom, from when the loom is preparing to start or when the loom is started (in this example, when the switch 40 is turned on during the start preparation) It constitutes a means for applying pressurized air to the air cylinder 33, which is the special tension applying means, until the period of time has elapsed.

Next, the action will be explained.

When the switch 40 is closed when restarting the loom, the relay 41 is energized and the relay contacts 41a, 41b, 41c including the self-holding contact 41a are activated.
is closed, the auxiliary equipment is activated, and the electromagnetic solenoid 77 of the electromagnetic on-off valve 36 is energized. Therefore, the valve body 73 is pulled up by the electromagnetic force, and pressurized air flows into the air chamber 67 via the inlet hole 68, the through hole 69, the valve chamber 70, and the through hole 71, and the piston 6
4. Therefore, push down the output rod 34. Incidentally, even during such air supply, some of the air flows through the exhaust hole 8.
1,82, but the amount of discharged air is extremely small and has no effect. As a result, the output rod 34 comes into contact with the easing lever 6 via the protruding engagement body 35 and rotates it clockwise. Therefore, Batcrawler 3
The tension applied to the warp yarns 2 through the warp yarns 2 is increased, the woven fabric returns to its proper position, and thin tiers are prevented.

Next, when switch 42 is closed, relay 43
is excited, the relay contact 43a is closed and self-retained, and the loom drive motor is activated.

This causes the loom to rotate, and each time the loom rotates, the action piece 48 switches the proximity switch 4.
9 emits a pulse, so if the set number of the counting circuit 50 is set to 4, an output signal will be transmitted from the counting circuit 50 after 4 rotations, that is, 4 picks.
This output signal activates the actuating circuit 51 and thereafter keeps the contact 52 open.

At this time, the electromagnetic solenoid 77 of the electromagnetic on-off valve 36 is demagnetized, so the valve body 73
5 is pushed down and comes into close contact with the valve seat 72, and the through hole 6
9 is closed and the supply of pressurized air is stopped. Therefore, after this, the pressurized air in the air chamber 67 flows through the through hole 7.
1 and continues to leak from the discharge holes 81 and 82, and the pressure gradually decreases, so the spring 6
5 causes the piston 64 and therefore the output rod 34
is pulled up, and the force exerted on the easing lever 6 by the engaging body 35 gradually decreases until it stops operating. From then on, the easing lever 6 operates normally. The time for the force decay can be set by adjusting the throttle valve 84.

Therefore, even after the predetermined working time has elapsed, the tension applying means continues to act for a while even though the applied tension is reduced, so even if the tension returns to normal even if it takes a few seconds to return to normal, it will not work. No steps occur, and since the applied tension is released slowly, no tension fluctuation occurs.

When a stop signal is sent from the stop circuit 45, the counting circuit 50 is reset, the contacts 44 are opened, the relay 46 is demagnetized, the relay contacts 46a, 46b, and 46c are opened, and the relays 41, 43's self-retention has been lifted,
Auxiliary equipment and loom drive motors are also stopped.

Incidentally, the tension may be increased by causing the engaging body to engage directly with the warp yarns, separately from the warp roller, using an actuator such as an air cylinder.
When an air cylinder is used as the actuator, there is an advantage that even if the easing lever swings due to opening and closing of the warp threads, the engaging body can sufficiently follow the swinging.

As explained above, the present invention uses pressurized air to elastically apply tension to the warp yarns from when preparing to start the loom or from the time of starting until a predetermined period of at least one revolution has passed after starting. The applied tension is released gradually after a predetermined period of time, and the release time can be adjusted, so it is effective without fluctuations in tension or affected by variations in warp quality. It can prevent weaving.

[Brief explanation of the drawing]

The drawings show an embodiment of the apparatus of the present invention; FIG. 1 is a side view of the main parts of a loom, FIG. 2 is an enlarged sectional view of an air cylinder, and FIG. 3 is an operating circuit diagram of an electromagnetic on-off valve. 1... Warp beam, 2... Warp, 3... Cross roller, 6... Easing lever, 8... Tension spring, 33... Air cylinder, 34
...output rod, 35...engaging body, 36...electromagnetic on-off valve, 67...air chamber, 81, 82...discharge hole, 84...throttle valve.

Claims (1)

[Claims] 1. In a loom in which the warp threads pulled out from the warp beam are guided to the weaving front while being applied with a predetermined tension by an elastically supported guide body, the warp threads are guided by using air pressurized with special tension on the warp threads. an extra tension imparting means that can be applied elastically; and means for applying pressurized air to the extra tension imparting means until a predetermined period of at least one rotation has elapsed from when the loom is preparing to start or when the loom has been started; A weaving stage of a loom, characterized in that it is provided with means for gradually reducing the specially applied tension by reducing the pressure of the pressurized air after the predetermined period has elapsed, and means for adjusting the pressure reduction of the pressurized air. Prevention device.