JPH09291442A - Jetting of weft inserting nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for jetting of a weft inserting nozzle so as not to cause defects such as weft slack and kinky filling in a woven fabric by improving the jetting method of a weft inserting nozzle. SOLUTION: In a weft inserting apparatus 1 for carrying out weft inserting, a driving signal in a pulse line is outputted to solenoid valves 18 and 19 just before jetting of weft inserting nozzles 10 and 11 is completed. The solenoid valves 18 and 19 are opened and closed at each pulse and the pressure of at the output side of the solenoid valves 18 and 19 is reduced to gradually decrease jetting pressure of the weft inserting nozzles 10 and 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of gradually opening and closing an injection pressure of a weft insertion nozzle by opening and closing an electromagnetic valve for each pulse by a pulse train drive signal.

[0002]

2. Description of the Related Art In an air jet loom, a weft insertion nozzle continuously injects pressurized air over an injection period to insert a weft yarn into an opening. For this reason, the solenoid valve is driven on and off by the drive signal.

[0003]

However, when the drive signal is turned off and the solenoid valve is closed, the injection pressure of the weft insertion nozzle is instantly reduced and the weft feed force is also rapidly reduced. Therefore, in the case of a contractible weft yarn such as a twisted yarn, vibration is generated in the weft yarn, and the warp or looseness is likely to occur. As a result, the frequency of occurrence of weaving defects and poor weft insertion increases.

[0004]

OBJECTS OF THE INVENTION It is an object of the present invention to improve the method of jetting a weft insertion nozzle so that defects such as looseness and warp of a woven fabric do not occur.

[0005]

To achieve the above object, the present invention drives a solenoid valve provided between a pressure air source and a weft insertion nozzle to drive the pressure air from the pressure air source into the weft insertion nozzle. In the weft insertion device that injects the weft yarn into the warp yarn opening by jetting from the device, a drive signal of a pulse train is output to the solenoid valve immediately before the end of the injection of the weft insertion nozzle to open and close the solenoid valve for each pulse. , The output pressure of the solenoid valve is reduced to gradually reduce the injection pressure of the weft insertion nozzle, thereby solving the above problem.

In particular, the present invention changes the pulse train characteristic of the drive signal of the pulse train, that is, at least one of the pulse width and the pulse interval with the passage of time to reduce the pressure on the output side of the solenoid valve, thereby reducing the weft insertion nozzle. Of the solenoid valve without gradually changing the injection pressure of the pulse train or setting the amount of pressure decrease due to the pulse pause width of the pulse train drive signal larger than the amount of pressure increase in the pulse width, without changing the pulse train characteristics. The injection pressure of the weft insertion nozzle is gradually reduced by decreasing the output side pressure of the.

The weft insertion nozzles to be controlled are mainly main nozzles, but may be sub nozzles or main nozzles and sub nozzles. Further, the solenoid valve is usually a spring return type, which is opened when energized or de-energized, but may be of a type that is driven bidirectionally by an electromagnetic coil at a high speed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, FIG. 1 shows the relationship between a weft insertion device 1 and a weft insertion control device 2. In the weft insertion device 1, the weft yarn 3 is supplied from a yarn feeder 4, and is guided inside a rotary yarn guide 8 of a drum type length measuring and storing device 5, for example. When the rotating yarn guide 8 is rotated, the weft thread 3 locked by the locking pin 7 is wound around the drum 6 on the outer peripheral surface of the drum 6, and the length is measured for a length required for one pick weft insertion. , It will be stored until the time of putting katsuko. At the start of weft insertion, the solenoid 9
By retracting the locking pin 7 from the outer peripheral surface of the drum 6, the weft thread 3 in the length measurement storage state is unwound on the outer peripheral surface of the drum 6.

On the other hand, the main nozzle 10 serving as a weft insertion nozzle is located near the weft end on the weft insertion side, and the compressed air 1 is supplied over the injection period T1 from the start to the end of the weft insertion.
By jetting 2 toward the opening 15 of the warp thread 14, the weft thread 3 guided into the main nozzle 10 is inserted into the opening 15. At the same time, the plural groups of sub-nozzles 11 as weft insertion nozzles continuously pulse-inject the pressure air 13 over the flying period of the weft thread 3 as in this specific example, or, although not illustrated, the weft thread 3
The flying of the weft yarn 3 is urged by relay-injecting the pressure air 13 in a state of being synchronized with the flying velocity of.

Pressure air 12, 13 for this weft insertion
Are respectively supplied from pressure air sources 16 and 17 capable of pressure control, and the pressure air sources 16 and 17 and the main nozzle 10,
It is supplied by opening the solenoid valves 18 and 19 provided between the sub nozzle 11 and the sub nozzle 11. These solenoid valves 18 and 19 are controlled by the weft insertion control device 2.

The tip end of the weft thread 3 that has been wefted is detected by the detector 20 as a signal of arrival of the weft thread at, for example, the position of the weaving edge on the non-weft insertion side, and is sent to the weft insertion control device 2. After that, the weft thread 3 is struck by the reed 42 before weaving.

Next, FIG. 2 shows the construction of the weft insertion control device 2. The weft-insertion control device 2 is a part for executing the method of the present invention.
A drive control unit 21 that opens and closes the solenoid valves 18 and 19 based on pulse train drive signals Dm2, Ds1, and Ds2, and pressure commands P1 and P2 that control the pressure air sources 16 and 17 in response to changes in weft arrival. It is composed of the pressure command unit 22 which is sent to the means 23 and 24.

The drive control unit 21 includes an encoder 26 connected to a main shaft 25 of the loom, a signal of a rotation angle θ of the encoder 26, and an injection angle θs set by a setter 27.
Using the signals of θt and θe as input, the locking pin 7 and the solenoid valve 1
Unwinding timing signal Tp, injection timing signals Tvm1, Tvm2, Tvs1, Tvs necessary for controlling 8 and 19
A pulse width t1 and a pulse interval (pulse period) t2 signal as pulse characteristic data set by a timing controller 28 for generating 2 and injection timing signals Tvm2, Tvs1, Tvs2 and a pulse characteristic setting device 29, and a change in pulse train characteristic. The electromagnetic valve 18 is driven with the amount α as an input, the chopping controller 30 that generates pulse train drive signals Dm2, Ds1, and Ds2, the injection timing signal Tvm1 (drive signal Dm1) from the OR gate 33, and the pulse train drive signal Dm2 as inputs. Driver 31, and pulse train drive signals Ds1, Ds
2 is assembled by a driver 32 that drives the solenoid valve 19.

When the pulse width t1 is decreased by Δt1 for each pulse output or the pulse interval t2 is decreased or increased by Δt2 based on the change amount α of the pulse train characteristic, the change amount α is -Δt1, -Δt
It is given as 2 or + Δt2.

The pressure command unit 22 receives the weft yarn arrival signal from the detector 20 as an input and detects the weft yarn arrival timing θa on the rotation angle θ. The arrival detector 34 detects the weft yarn arrival timing θa and sets a reference signal. By comparing the arrival timing reference value θo set by the instrument 35,
A deviation calculator 36 for generating a deviation Δθ, a manipulated variable calculator 37 for calculating a pressure manipulated variable ΔP from the deviation Δθ, a pressure manipulated variable ΔP and an initial pressure value Po set by a setter 38 are compared, It is assembled by a pressure command device 39 that generates signals of pressure commands P1 and P2.

During weft insertion, the deviation calculator 36 compares the signal of the weft thread arrival timing θa from the arrival detector 34 with a preset reference value θo, and the rotation angle θ of the main shaft 25.
The deviation Δθ is obtained above and is output to the manipulated variable calculator 37. Here, the manipulated variable calculator 37 converts the manipulated variable ΔP of the pressure for eliminating the deviation Δθ and outputs it to the pressure command device 39. Therefore, the pressure command device 39 outputs the signals of the pressure commands P1 and P2 to the pressure control means 23 and 24 by inputting the manipulated variable ΔP of the pressure and the preset initial pressure value Po.

The signals of the pressure commands P1 and P2 change the maximum pressure of the pressure air sources 16 and 17 in a direction to eliminate the deviation Δθ. Specifically, the actual arrival of the weft is delayed,
When the deviation Δθ occurs, the pressure commands P1 and P2 are adjusted so as to increase the pressure, and when the weft thread arrives quickly and the deviation Δθ occurs, the pressure commands P1 and P2 lower the pressure. To be adjusted.

On the other hand, the timing controller 28 synchronizes with the rotation of the main shaft 28 to drive the locking pin 7 for the unlocking period corresponding to the weft insertion period, so as to drive the unlocking timing signal Tp over the unlocking period. At the same time, the signals required for opening and closing the solenoid valves 18 and 19 are generated during the injection period T1 of the main nozzle 10 and the sub nozzle 11.

That is, the timing controller 28
Outputs the continuous injection timing signal Tvm1 corresponding to the injection angle θs to the injection angle θt as the drive signal Dm1 during the constant pressure period T2 in the first half of the injection period T1, and gradually decreases the injection pressure just before the end of injection. Therefore, the injection timing signal Tv corresponding to the injection angle θt to the injection angle θe over the latter depressurization period T3.
In addition to outputting m2, in order to maintain the injection pressure constant during the constant pressure period T2 of the injection period T1 of the sub-nozzle 11, the injection timing signal Tvs1 is output, and the injection pressure is gradually decreased during the depressurization period T3 just before the end of injection. In order to cause it, the injection timing signal Tvs2 is output.

Therefore, the chopping controller 30 is
During the generation period of the injection timings Tvm1 and Tvs1 (constant pressure period T2), the continuous drive signal Dm1 and the drive signal Ds1 with invariable pulse characteristics are generated, and at the generation period of the injection timing signals Tvm2 and Tvs2 (pressure reduction period T3), The pulse characteristics (pulse width t1 or pulse interval t2, or pulse width t1 and pulse interval t2) of the pulse train drive signals Dm2 and Ds2 are set in the setter 29 by an instruction of the change amount α of the pulse train characteristics, and if necessary. Main shaft 2 while fetching pressure commands P1 and P2
By changing in synchronization with the rotation of 5, the drive signals Dm2 and Ds2 of appropriate pulse trains are output to the drivers 31 and 32 via the OR gate 33 or directly.

As a result, as shown in FIG. 3, the drive signal D
m1 is a continuous constant level output in the constant pressure period T2, and the drive signal Dm2 is the output of the pressure reduction period T.
3, the pulse width t1 and the pulse interval t2 are synchronized with the advance of the rotation angle θ by Δ for each pulse output.
The waveform is such that it decreases by t1 and Δt2. The pulse train drive signal Ds1 has a constant pulse width t1 and a constant pulse interval t2 in the constant pressure period T2, but the pulse train drive signal Ds2 has a pulse width t1 in the depressurization period T3.
And a waveform that reduces the pulse interval t2.
Each pulse width t1 in the depressurization period T3 is set to a sufficiently short time so that the pressure on the output side does not reach the initial pressure value Po even if the solenoid valve is opened by the pulse.

From the pressure command section 22, the pressure control means 2
Output a constant pressure command P (> Po) to 4 and
The pressure command P2 from the pressure command unit 22 based on the deviation Δθ is output only to the chopping controller 30, and the chopping controller 30 outputs the pulse train characteristic of the pulse train drive signal Ds1 so that the pressure on the output side of the solenoid valve 19 becomes P2. May be changed appropriately. Further, the pulse train drive signal Ds1 may be a continuous constant level signal like the drive signal Dm1.

The initial pulse characteristics (pulse width t1, pulse interval t2) in the pressure reduction period T3 are set in advance based on the initial pressure value Po and the pressure rising characteristics.

In this way, the solenoid valves 18 and 19 have continuous drive signals Dm1 and pulse train drive signals Dm2 and Dm.
Opening and closing are repeated in synchronization with s1 and Ds2. As a result,
The waveform of the injection pressure injected from the main nozzle 10 or the sub nozzle 11 is constant during the constant pressure period T2 as shown in FIG.
Since the period in which 9 is opened is gradually shortened and the amount of pressure increase is also small, the injection pressure is gradually reduced.

The pressure drop during the depressurization period T3 may be performed by keeping the pulse width t1 constant and gradually increasing the pulse interval t2 to increase the pressure drop amount, or by gradually decreasing the pulse width t1. However, it can also be realized by keeping the pulse interval t2 constant. Further, the control target may be only the main nozzle 10, and at this time, the sub-nozzle 11 continuously injects by continuously opening the solenoid valve 19, as in the conventional case,
Keep the pressure constant. Conversely, the control target may be only the sub nozzle 11.

Next, the concrete example of FIG.
Regarding the constant pressure period T2, the pulse train drive signal Dm1
To drive the solenoid valve 18 to perform pulsed injection from the main nozzle 10, and the change amount α in the depressurization period T3.
Is an example in which the pulse train characteristic of the pulse train drive signal Dm2 is changed to gradually reduce the injection pressure of the main nozzle 10. As a result, the injection form of the main nozzle 10 is
As shown in FIG. 5, the ejection form of the sub nozzle 11 is the same.

According to this specific example, the injection timing signal Tvm1 becomes an input to the chopping controller 30 and the constant pressure period T2 from the injection angle θs to the injection angle θt.
Then, the chopping controller 30 is caused to generate the pulse train drive signal Dm1. Therefore, the OR gate 33
Has been omitted.

In the above specific example, in order to gradually reduce the injection pressure of the main nozzle 10 and the sub nozzle 11 as the weft insertion nozzles, pulse train drive signals Dm2 and Dm are used.
The s2 pulse train characteristic is changed. However, as shown in FIG. 6, the decrease of the injection pressure in the pressure reduction period T3 is due to the pulse pause width t3 for the pulse train drive signals Dm2 and Ds2.
By setting the pressure decrease amount due to the pressure increase amount larger than the pressure increase amount at the pulse width t1, it can be realized without changing the pulse train characteristics. In other words, the amount of pressure drop during the period t3 when the solenoid valves 18 and 19 are closed is calculated as follows.
If it is set to be larger than the amount of increase in the pressure during the period t1 in which 8 and 19 are open, the pressure can be gradually decreased without changing the pulse train characteristics.

In the example of FIG. 7, the initial pressure value Po, the pressure reduction period T3, and the pulse train characteristics (pulse width t1, pulse interval t2) corresponding to the initial pressure value Po are stored in the storage device 40 and stored from the setter 41. This is an example in which the address (AD) is specified by the signal of the setting data S, the command data (DATA) of the pulse train characteristic corresponding to the address is read, and is output to the chopping controller 30. The address and the data are previously input to the storage device 40 by the data input device 43, the pattern calculator 44 and the like.

Further, in the example of FIGS. 8 and 9, for example, in order to perform finer high-speed intermittent supply of the compressed air in the depressurization period T3, in other words, in order to make the change range of the pressure smaller, Inserting nozzle, for example, main nozzle 1
0 and the pressure air source 16 between the two solenoid valves 18a, 18
b is installed in parallel, and the drive signal Dm2a as the output of the chopping controller 30 and the inversion circuit 4
In this example, the drive signal Dm2b inverted by 5 is alternately output to the drivers 31a and 31b of the solenoid valves 18a and 18b.

As a result, as shown in FIG. 10, the air supply cycle to the main nozzle 10 is two drive signals Dm.
2a and Dm2b are combined. Therefore, the pressure air 12 supplied to the main nozzle 10 is 2
Corresponding to the two drive signals Dm2a and Dm2b, they are supplied in a partially overlapped state as triangular wave shapes having different heights on the time axis.

Further, as shown in FIG. 11, the pulse width t1a and the pulse interval t2a of one drive signal Dm2a and the pulse width t2b and the pulse interval t of the other drive signal Dm2b.
When 2b are the same and the phases are different, the pressure air 12 supplied to the weft insertion nozzle (main nozzle 10) is
The products of the same size are alternately repeated, and they are supplied in a partially overlapped state.

When the pressurized air 12 is supplied to the main nozzle 10 by using the solenoid valve shown in FIGS. 8 to 10 or 11, one or both solenoid valves are continuously opened in the constant pressure period T2. The pulse train drive signals Dm2a and Dm2b may be output to the two solenoid valves in the depressurization period T3, and the pulse characteristics may be changed so that the pressure on the output side gradually decreases.

As in the above embodiment, the constant pressure period T2
Also in the above, the solenoid valve may be driven by the drive signal of the pulse train, or the output side pressure may be gradually reduced by keeping the pulse characteristics of the pulse train drive signal in the depressurization period T3 constant. .

The above-mentioned specific examples are provided with two solenoid valves 18.
This is an example in which a and 18b are provided in parallel, but for higher speed, three or more of these solenoid valves are provided in a parallel state and are alternately driven by using drive signals of three pulse trains having mutually different phases. You may do it.

[0036]

According to the present invention, a pulse train drive signal is output to the solenoid valve, the solenoid valve is opened and closed for each pulse, and the pressure on the output side of the solenoid valve is reduced immediately before the end of the injection of the weft insertion nozzle. Since the injection pressure of the weft insertion nozzle is gradually reduced, even with a contractible weft thread such as a twisted thread, vibration does not easily occur in the weft thread, and there is no chattering or looseness.
The frequency of weaving defects and weft insertion defects is reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a weft insertion device.

FIG. 2 is a block diagram of a weft insertion control device.

FIG. 3 is a time chart diagram showing changes in pressure air supplied to the weft insertion nozzle with respect to a drive signal of a pulse train.

FIG. 4 is a block diagram of another specific example of the weft insertion control device.

FIG. 5 is a time chart diagram showing changes in pressure of pressurized air supplied to a weft insertion nozzle with respect to a drive signal of a pulse train.

FIG. 6 is a time chart diagram showing changes in pressure air supplied to the weft insertion nozzle with respect to a drive signal of a pulse train.

FIG. 7 is a block diagram of a part of the weft insertion control device.

FIG. 8 is an explanatory diagram of an example in which solenoid valves are provided in parallel.

FIG. 9 is a block diagram of a drive portion for two solenoid valves.

FIG. 10 is an explanatory diagram of a supply cycle of the compressed air and a waveform of the compressed air with respect to a drive signal of two pulse trains.

FIG. 11 is an explanatory diagram of a supply cycle of pressure air and a waveform of pressure air for a drive signal of two pulse trains.

[Explanation of symbols]

 1 Weft insertion device 2 Weft insertion control device 3 Weft yarn 10 Main nozzle 11 Sub nozzle 12 Pressure air 13 Pressure air 14 Warp yarn 15 Opening 16 Pressure air source 17 Pressure air source 18 Solenoid valve 19 Solenoid valve 20 Detector 21 Drive control unit 22 Pressure command Department 28 Timing controller 30 Chopping controller

Claims (3)

[Claims] 1. A pressure air source (16, 1) at the time of weft insertion.
7) and the solenoid valve (18, 19) provided between the weft insertion nozzle (10, 11) are driven, and the pressure air source (1
6,17) Wefting device (6) for wetting the weft thread (3) into the opening (15) of the warp thread (14) by injecting pressurized air (12, 13) from the weft insertion nozzle (10, 11). In 1), a pulse train drive signal is output to the solenoid valve (18, 19) immediately before the end of the injection of the weft-in nozzle (10, 11), and the solenoid valve (18, 19) is opened and closed for each pulse. Valve (1
The method for injecting a wetting nozzle, characterized in that the injection pressure of the wetting nozzle (10, 11) is gradually reduced by decreasing the output side pressure of (8, 19). 2. The pulse train characteristic of the drive signal of the pulse train is changed with the passage of time.
The method for spraying the described weft insertion nozzle. 3. The pulse train characteristic is set so that the amount of decrease in pressure due to the pulse rest width of the pulse train drive signal is larger than the amount of increase in pressure in the pulse width, and the pulse train characteristic is constant. The method for spraying a weft insertion nozzle according to claim 1.