JPH03206149A - Picking control unit in jet loom - Google Patents

Abstract

PURPOSE:To provide the title unit intended to make a pressure regulation through simple control, so designed that electromagnetically switching valves are put for pressure regulation between a original pressurized air source and pressurized air feed tanks to feed picking nozzles with pressurized air. CONSTITUTION:Electromagnetically switching valves V6 and V7 are put as pressure regulatory valves between an original pressurized air source 13 and pressurized air feed tanks 11, 12 to feed picking nozzles 2, 3, 4, 5, 6 with pressurized air. In this way, the pressure regulation during loom operation can be performed by a simple control, so called on-off control.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a weft insertion control device in a jet loom that inserts weft yarns by a jet stream from a weft insertion nozzle.

[Prior Art] This type of jet loom is disclosed in Japanese Patent Laid-Open Nos. 62-162050 and 63-92753.

Unexamined Japanese Patent Publication No. 1986 2-1. Japanese Patent No. 62050 discloses a device for diagnosing the causes of weft insertion errors, which makes it possible to ascertain the cause of weft insertion errors. Based on this understanding of the cause, the pressure is adjusted, for example, by manually operating a pressure regulator between a pressure air supply tank for supplying pressurized air to the weft insertion nozzle and a source of pressure air. However, with this, the weft cheese diameter changes during loom operation.
It is not possible to carry out weft insertion control that can cope with variations in the weft insertion situation depending on yarn unevenness or injection pressure fluctuations.

In Japanese Unexamined Patent Application Publication No. 63-92753, an automatic pressure regulating valve is interposed between the pressurized air supply tank and the main pressure air source,
The valve opening degree of the automatic pressure regulating valve is adjusted based on a comparison between the time when the inserted weft reaches the tip and the set weft tip arrival time. This makes it possible to perform weft insertion control by adjusting the pressure during operation of the loom.

[Problem to be solved by the invention] As an automatic pressure regulating valve, a combination structure of a diaphragm and a proportional solenoid or an electric motor is used.
Automatic pressure regulating valves with such a configuration are expensive and have low reliability.

SUMMARY OF THE INVENTION An object of the present invention is to provide a weft insertion control device that can reduce the cost of weft insertion control by adjusting pressure and avoid complication of weft insertion control.

[Means for Solving the Problems] Therefore, in the present invention, an electromagnetic switching valve for pressure adjustment is interposed between the pressure air supply tank that supplies pressure air to the weft insertion nozzle and the source pressure air source.

] The electromagnetic switching valve is subject to open time control or open/close frequency control; increasing the open time or opening/closing frequency will increase the pressure in the pressure air supply tank, and decreasing the opening time or opening/closing frequency will increase the pressure in the pressure air tank. The internal pressure decreases. Curve D in FIG.

As the frequency of opening and closing of the electromagnetic switching valve increases, the pressure inside the pressure air tank approaches the original pressure as shown by the curve Eo. Thereby, the pressure inside the pressure air supply tank can be maintained at a predetermined pressure. Such an electromagnetic switching valve is less expensive than a conventional automatic pressure regulating valve, and moreover, opening time and opening/closing frequency can be easily controlled.

[Embodiments] Hereinafter, embodiments embodying the present invention will be described based on the drawings.

[Embodiments] Hereinafter, embodiments embodying the present invention will be described based on the drawings.

3 is a winding type weft length measurement and storage device, in which the weft Y whose length has been measured and stored in the weft length measurement and storage device 1 is ejected from a main nozzle 2 for weft insertion, and is inserted through a plurality of auxiliary nozzle groups 3 for weft insertion.
, 4, 5.6 relay injection. If the weft insertion is successful, the weft is detected by the weft detector 7 within a predetermined loom rotation angle range, and the loom continues to operate.

If the weft detector 7 does not detect the presence of a weft within a predetermined loom rotation angle range, the loom operation is stopped.

The weft yarn is pulled out from the yarn winding surface 1a of the weft length measuring and storage device 1, unwound, and stopped by excitation and demagnetization of the electromagnetic solenoid 8 that drives the locking pin 8a.

Excitation/demagnetization control of the electromagnetic solenoid 8 is performed by commands from a control computer C, and the control computer C controls excitation/demagnetization of the electromagnetic solenoid 8 based on a detection signal from a rotary encoder 9. A weft yarn unwinding detector}0 consisting of a reflective photoelectric sensor is arranged near the yarn winding surface 1a, and the weft yarn Y pulled out from the yarn winding surface 1a and unwound is detected by the weft yarn unwinding detector 10. Ru.

Pressure air injection from the main nozzle 2 for weft insertion is controlled by opening and opening of a three-way electromagnetic switching valve V; pressurized air injection from the weft insertion auxiliary nozzle groups 3 to 6 is controlled by a three-way electromagnetic switching valve V2 + V3! Controlled by opening and closing of V4 +V5. The electromagnetic switching valve V1 is connected to the pressure air supply tank 11, and the electromagnetic switching valves V2 to V5 are connected to the pressure air supply tank l2. The opening/closing control of each electromagnetic switching valve Vl, V2 to V5 is performed by commands from the control computer C, and the control computer C commands the opening and closing of each electromagnetic switching valve Vl, V2 to V5 based on the υ signal from the low-return encoder 9. do.

Each pressurized air supply tank 11.12 is connected to the main pressure air source l3, and a three-way electromagnetic switching valve V s is connected between each pressure air supply tank 11.12 and the main pressure air source l3.
, V y are interposed.

Pressure air supply tank 11 from source pressure air source l3. , 12 is controlled by opening and closing electromagnetic switching valves Vs, V7, and air from the original pressure air source 13 is supplied to the pressure air supply tanks 11, 2 after being reduced in pressure. Further, pressure sensors 14, 15, 16 are attached to the pressure air supply tank 11.12 and the source pressure air source I3, and the pressure information obtained by each pressure sensor 14, 15, 16 is taken into the control computer C. .

The data memory C1 of the control computer C stores the target arrival time Tω when the tip of the inserted weft yarn Y reaches the installation position of the weft yarn detector 11, the allowable time difference ΔTω regarding the target arrival time Tω, the excitation/demagnetization timing of the electromagnetic solenoid 8, The opening/closing timing of each electromagnetic switching valve Vl+V2 to V5 is input and set by a manual setting device 7. In addition, in the data memory C+, the initial target pressure of each pressure air supply tank 11. This initial target pressure becomes the target pressure of the pressurized air supply tanks 11 and 12 when the loom starts operating.

The central processing unit CPU of the control computer C performs the weft insertion control shown in the flowchart of FIG. 3 based on these input data and the weft insertion control program input and set in the program memory C2.

When the weaving state is entered, the control computer C controls the weft insertion injection pressure in the main weft insertion nozzle 2 and the auxiliary weft insertion nozzles 3 to 6 in accordance with the weft insertion control program. The control computer C detects the detected pressure P from the pressure sensor 14 at a predetermined timing every time the machine rotates. 8. Pressure sensor 1
The detected pressure PIX from 5 and the detected pressure Pzx from pressure sensor 16 are sampled to obtain the detected pressure P. ．． and the target pressure P1 in the pressure air supply tank 1L (po.
P1), and detected pressure P. The difference (PO-P2) between X and the target pressure P2 in the pressure air supply tank 12 is calculated. Control computer C is calculated value (Paep+)
The duty ratio of the solenoid switching valve V6 is controlled according to the calculated value (POx P2), and the solenoid switching valve V
The opening and closing of 7 is controlled by the duty ratio.

The curve D1 in the graph of FIG. 3(a) is the difference (Pox
The curve D2 in the graph of FIG. 3(b) shows the electric signal curve applied to the electromagnetic switching valve V6 when the difference (Po− P+(〉0) is large). The electric signal curve applied to V6 is shown.The pulse widths of both electric signal curves D I and D2 are the same, and the constant time t in the electric signal curve D1 is shown.
The number of pulses per unit is smaller than the number of pulses per constant time t in the electrical signal curve D2. That is, the electromagnetic switching valve v6 is subject to opening/closing frequency control, and the control computer)? is the detected pressure P at the source pressure air source 13. Difference between target pressure P1 in pressure air supply tank l1 (Po.P
+) is large, the frequency of opening and closing of the electromagnetic switching valve V6 is reduced, and when the difference (Pa.P+) is small, the frequency of opening and closing of the electromagnetic switching valve V6 is increased. Difference (po.
If the difference (Plllxp+) is large, it means that the pressure of the original pressure air source 13 is high, and if the difference (Plllxp+) is small, it means that the pressure of the original pressure air source 13 is low. Therefore, the difference (P
o. If P+) is large, pressurized air supply tank 1
There is no need to speed up the pressure air supply to 1, and the difference (po
(2) When p+) is small, it is necessary to speed up the pressure air supply to the pressure air supply tank 11.

The curve E1 in the graph of FIG. 3(a') shows the pressure fluctuation of the pressure air supply tank 1l with respect to the electric signal curve D1, and the curve E2 in the graph of FIG. 3(b) shows the pressure fluctuation of the pressure air supply tank 1l with respect to the electric signal curve D1. 11 pressure fluctuations are shown.

The control computer C stores the target pressure P1 and the detected pressure P1 of the pressure air supply tank 1l. Calculate the difference (p+ -P?!) between lp+-p, . 1 and the allowable error ΔP1. IPI P+■1 is the allowable pressure difference ΔP1
If it is, the control computer C determines the weft tip arrival time Tω8 based on the weft tip arrival information from the weft detector 7, and calculates the average value <Tω,> of the predetermined weft insertion number unit regarding the weft tip arrival time Tωe. Calculated for each rotation of the machine.

Average value〈Tω. > and the set weft tip arrival time Tw
If 1Tω - <Tω,> 1 is less than the set allowable time difference ΔTω, the control computer C activates the pressure sensors 14, 1 while maintaining the target pressure P1 in the pressure air supply tank l1.
Perform pressure detection sampling according to 5.16.
If ITω1 <Tω,>1 exceeds the allowable time difference ΔTω, the control computer C instructs the target pressure to be changed in a direction that reduces the difference between the average value <Tω8> and the set weft tip arrival time Tw. That is, in the case of <Tω,>−Tω<0, the target pressure P1 is reduced, and <Tω>−Tw>0.
In this case, the target pressure P1 is increased. Then, the control computer C calculates (poAP+) based on the changed target pressure P1, controls the duty ratio according to (Po-P+), calculates (P+P+E), and calculates (P+P+E).
A comparison is made between PI PIf+ and the allowable pressure difference ΔP1.

If P+ P+xl exceeds the allowable pressure difference ΔP1,
The control computer C calculates (Pox-P1), calculates (P+ P+-), and calculates IP 1P +-1 until IP+ P+-l converges within the allowable pressure difference ΔP1.
Repeat the comparison between ip+p and allowable pressure difference ΔP1, and get ip+p
、． 1 converges within the allowable pressure difference △P1
Let us move on to a comparison between ω1〈Tω,〉1 and the allowable time difference Δt.

Such pressure control is similarly performed on the pressure air supply tank 12 side, and the electromagnetic switching valves Va and Vy for pressure control are cheaper than conventional proportional solenoid or electric motor type automatic pressure regulating valves. be. Furthermore, the control method is simple, such as opening/closing frequency control, and weft insertion control can be simplified.

It should be noted that fluctuations in the pressure in the air tank 11.12 are reflected in the injection pressure at the main weft insertion nozzle 2 and the auxiliary weft insertion nozzle groups 3 to 6 without much time delay, and the fluctuation in the timing at which the weft tip reaches the air tank 11.12 The pressure fluctuations detected by the pressure sensors 15 and 16 directly connected to the pressure sensors 15 and 16 are followed without much time delay. Therefore, there is a high probability that the difference between the weft tip arrival time detected during such pressure fluctuations and the set weft tip arrival time Tω does not fall within the allowable time difference ΔTω, leading to a detection error in the weft tip arrival time. In this embodiment, when the pressure fluctuates like this, that is, when the difference between the detected pressure Plx (1=1 or 2) and the target pressure P exceeds the allowable pressure difference ΔP1, the weft tip arrival time and the set weft tip arrival time No comparison with Tω is made, only a pressure comparison is performed. Therefore, the timing at which the weft tip reaches is not detected when the air pressure in the air tank 11. It never gets in.

Of course, it is also possible to perform pressure control that takes into account the detected information on the weft tip arrival time when the air pressure in the air tank 11 or 12 has not reached the target pressure. By doing so, it is possible to contribute to accurate pressure control.

Of course, the present invention is not limited to the above-mentioned embodiment, and for example, curve D3. As shown by D4, a pulse signal may be applied to the electromagnetic switching valves Vs, Vy once every fixed time t, and open time control may be performed instead of open/close frequency control. Curve D3
is selected when the difference between the target pressure of the pressure air supply tank 11.12 and the detected pressure of the original pressure air source 13 is large, and curve D is selected when the difference between the target pressure of the pressure air supply tank 11.12 and the detected pressure of the original pressure air source 13 Selected when the difference between the detected pressure and the detected pressure is small. Curve E3 is the pressure air supply tank 1 corresponding to curve D3.
1.12, curve E, is the pressure curve of the pressure air supply tank 11.12 corresponding to curve D,.

Furthermore, in the embodiment described above, the duty ratio control for opening/closing control of the electromagnetic switching valves Vs and Vy is performed by the pressure air supply tank 11.
．． Although this is carried out based only on the difference between the target pressure of No. 12 and the detected pressure of the main pressure air source 13, the pressure air supply tank It
, 12 or the pressure detected by the main pressure air source 13 may be taken into account.

In this way, the time required to bring the pressure in the pressure air supply tanks 11, 12 to the target pressure will be shorter than in the embodiment described above, making it possible to speed up the weft insertion control.

Furthermore, in the present invention, in order to perform pressure control by opening and closing the electromagnetic switching valves V6 and Vy, a pressure air supply tank 11.1 is provided.
An embodiment in which only the second detected pressure is used as a control element is also possible.

[Effects of the Invention] As detailed above, the present invention uses an electromagnetic switching valve as a pressure regulating valve between the pressure air supply tank that supplies pressure air to the weft insertion nozzle and the source of pressure air. The pressure can be adjusted during the operation of the loom by simple control, and this has the excellent effect of achieving cost-effective and good weft insertion control.

[Brief explanation of drawings]

1 to 3 show embodiments embodying the present invention;
The figure is a combination diagram of the weft insertion device and the block circuit.
Figures (a) and (b) are graphs showing the relationship between the electrical signal applied to the electromagnetic switching valve and the pressure of the pressure air supply tank.
Figure 3 is a flowchart for pressure control;
Figures (a) and (b) are graphs showing other examples of electric signals applied to the electromagnetic switching valve, and Figure 5 is a graph explaining the principle of the present invention. Weft insertion main nozzle 1, weft insertion auxiliary nozzle group 3,
4, 5, 6, pressure air supply tank 11, l2
, source pressure air source 13, electromagnetic switching valves V6 and V7.

Claims (1)

[Claims] 1. In a jet loom where weft threads are inserted by a jet stream from a weft insertion nozzle, an electromagnetic switching valve for pressure adjustment is installed between a pressure air supply tank that supplies pressurized air to the weft insertion nozzle and a source of pressure air. Weft insertion control device in the jet loom.