JPH04228651A - Pressure control unit for weft inserting in jet loom - Google Patents

Abstract

PURPOSE:To enable automatic change of control factor values for control of injection pressure, e.g. the detected sampling number at a time when the end part of a weft yarn arrives, the range of variation of control pressure and the upper and lower limit values of allowable injection pressure at a stage of test weaving and a stage of final weaving. CONSTITUTION:Control factors for controlling injection pressure, e.g. the sampling number for unifying arrival time values of the end part of a weft yarn detected by a weft yarn detector 6, the range of variation of control pressure and the upper and lower limit values of allowable injection pressure are stored in a control computer (C2). When directing switch from a stage of test weaving to a stage of final weaving, control factors for final weaving are selected and a detected injection pressure value obtained by pressure gages 13 and 14 at a time of the above-mentioned switch is used as the standard injection pressure.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides a jet loom that inserts a weft yarn by the jetting action of a weft insertion nozzle and controls the jetting pressure in the weft insertion nozzle based on the detected information on when the weft yarn reaches the leading edge. This invention relates to a pressure control device for weft insertion.

0002

2. Description of the Related Art In a jet loom in which weft yarns are inserted by jetting pressurized air from a weft insertion nozzle, the insertion state of the weft yarns is greatly influenced by the pressure setting of the pressurized air. Even if the pressure suitable for the weft yarn is set at the trial weaving stage, the weft flying condition will fluctuate in the actual weaving stage due to the diameter of the weft cheese, unevenness of the weft, etc. It may not be possible to achieve this. Therefore, for example, in Japanese Patent Publication No. 64-3969, an electric pressure control valve is interposed on the pressure air supply path to the weft insertion nozzle, and information on the arrival time of the weft tip detected by a weft detector at the end of the weft insertion is provided. Electric control valves are driven and controlled based on the following.

0003

In drive control of the electric pressure control valve, control elements such as averaging of detected weft tip arrival timing, reference injection pressure, and control pressure change range are used. That is, in averaging the weft tip arrival times, a predetermined number of detected weft tip arrival times are sampled, and a predetermined control pressure change is performed within a predetermined pressure width centered on the reference injection pressure. The values of such control elements are different between the trial weaving stage and the weaving stage. For example, the control pressure change width is set large in the trial weaving stage to obtain the appropriate injection pressure quickly, but since the weft insertion condition is relatively stable in the weaving stage, the control pressure change width is set at the trial weaving stage. It is made smaller than. Furthermore, for the same reason, the pressure control range around the reference pressure is also narrower at the weaving stage than at the trial weaving stage. This pressure control range affects the controllability of the weft insertion state, and the appropriately narrower the injection pressure range, the better the controllability.

[0004] For these reasons, the values of the control elements for controlling the injection pressure in the trial weaving stage and the weaving stage are different.
When moving from the trial weaving stage to the weaving stage, the complexity of having to individually set the values of the control elements is unavoidable. An object of the present invention is to enable automatic switching of control element values for jet pressure control in the trial weaving stage and the weaving stage.

[0005]

[Means for Solving the Problems] In order to solve the problems, the first invention provides a weft tip arrival time detection means for detecting the weft tip arrival time, a pressure detection means for detecting the injection pressure in a weft inserting nozzle, and a detecting weft tip. In addition to storing control elements for injection pressure control in the trial weaving stage and control elements for injection pressure control in the weaving stage, such as the number of samples at the arrival time, the control pressure change width, or the upper and lower limits of allowable injection pressure, An injection pressure setting means for storing the detected injection pressure, an injection pressure adjustment means for adjusting the injection pressure according to a command from the injection pressure setting means, and switching for selecting one of the control elements in the trial weaving stage and the weaving stage. The means constitutes a pressure control device for weft insertion, and the injection pressure setting means is provided with a function of setting the detected pressure at the time of switching as a reference pressure.

[0006] In the second invention, the control element in the weaving stage is selected when a predetermined number of sampled weft tip arrival times in the trial weaving stage are within an allowable range and the degree of variation in the detected injection pressure is in a predetermined variation state. At the same time, the injection pressure setting means is provided with a function of setting the detected pressure at the time of this selection as a reference pressure.

[0007]

In the first invention, when the switching means selects the control element for the trial weaving stage, the injection pressure setting means controls the injection pressure adjusting means based on the control element for the trial weaving stage. When the switching means is operated to select a control element in the weaving stage, the injection pressure setting means adjusts and controls the injection pressure adjusting means based on the control element in the weaving stage. Further, the injection pressure setting means sets the injection pressure detected at the time of this switching operation as a reference pressure, and performs injection pressure control centered on this reference pressure.

[0008] In the second invention, when a predetermined number of sampled weft tip arrival timings are within an allowable range and the degree of fluctuation of the detected jet pressure reaches a predetermined fluctuation state, the jet pressure setting means controls the jet pressure in the weaving stage. will be automatically migrated.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the first invention will be described below with reference to FIGS. 1 to 5. Main nozzle for weft insertion 1
The weft yarn Y ejected from the weft inserting auxiliary nozzle group 2
, 3, 4, and 5, and if weft insertion is performed successfully, the weft yarn Y is detected by the weft yarn detector 6 within a predetermined machine rotation angle range. The weft presence/absence detection signal from the weft yarn detector 6 is input to the control computer C1, and the control computer C1 selects whether to continue or stop the operation of the loom based on the weft presence/absence detection signal.

The weft insertion pressure air injection in the weft insertion main nozzle 1 is controlled by opening and closing of the solenoid valve V1, and the weft insertion pressure air injection in the weft insertion auxiliary nozzle groups 2 to 5 is controlled by the solenoid valves V2, V3, and V4. , V5. The electromagnetic valve V1 is connected to the pressure air supply tank 7, and the electromagnetic valves V2 to V5 are connected to the pressure air supply tank 8. Each pressure air supply tank 7, 8 is connected to a main pressure tank 11 via an electric pressure control valve 9, 10.

[0011] The opening and closing control of each electromagnetic valve V1 to V5 is performed by a command from a control computer C1, and the control computer C1 controls the electromagnetic valves V1 to V5 based on a machine rotation angle detection signal from a rotary encoder 12.
commands to open and close. This command data is input and set in the data memory of the control computer C1, and the control computer C1 executes the weft insertion control command based on these data and the weft insertion control program input and set in the program memory.

Pressure detectors 13 and 14 are connected to the pressure air supply tanks 7 and 8, and pressure detection information from the pressure detectors 23 and 24 is input to the control computer C2. The control computer C2 performs feedback control of the pressure control valves 9 and 10 based on pressure information from the pressure detectors 13 and 14. The control computer C2 controls the pressure of the pressurized air supply tanks 7 and 8 based on the average value of the weft tip arrival timing of a predetermined number of times from the weft detector 6. An input device 15, a display device 16, and a mode changeover switch 17 are connected to the control computer C2. Data necessary for pressure control is inputted by the input device 15.

Screen G1 on the display device 16 in FIG.
indicates the value of the control element for controlling the injection pressure at the trial weaving stage. α1 represents the maximum value of the control pressure change range. This maximum change width α1 is used when the difference between the reference weft tip arrival time and the detected weft tip arrival time is β1 or more. γ1 is the number of samples of weft tip arrival times adopted for averaging the detected weft tip arrival times. Pm1 represents the initial pressure in the pressure air supply tank 7, and Ps1 represents the initial pressure in the pressure air supply tank 8. (Pm1 - ΔPm1) represents the lower limit of allowable injection pressure in the pressure air supply tank 7, and (Pm1 + ΔPm1)
Pm1) represents the upper limit. Similarly, (Ps1 - ΔPs
1) represents the lower limit of the allowable injection pressure in the pressure air supply tank 8, and (Ps1 +ΔPs1) represents the upper limit. These α1, β1, γ1, Pm1, ΔPm1, P
Control elements for injection pressure control such as s1 and ΔPs1 are employed in the trial weaving stage, and screen G1 represents the injection pressure adjustment mode in the trial weaving stage.

Screen G2 in FIG. 3 displays the detected weft tip arrival timing and the detected injection pressure. θ represents the detected weft tip timing, Pm2 represents the detected pressure in the pressurized air supply tank 7, and Ps2 represents the detected pressure in the pressurized air supply tank 8. Screen G2 in FIG. 4 is an operation mode screen that displays control elements in the weaving stage.

The flowchart in FIG. 5 is based on the screen G1 in FIG.
This represents a program for switching between the adjustment mode represented by screen G2 in FIG. 3, the detection mode represented by screen G2 in FIG. 4, and the operation mode represented by screen G3 in FIG.
executes injection pressure control in the trial weaving stage and the weaving stage according to this mode switching program. When the mode selector switch 17 is switched to the adjustment mode selection position, the control computer C2 displays the screen G1.
While selecting and setting the control elements above, screen G1
is output to the display device 16. When the activation signal is input, the control computer C2 switches from the adjustment mode screen G1 to the detection mode screen G2. Detection mode screen G2
In this case, the pressures of the pressure air supply tanks 7 and 8 controlled based on the control elements of the adjustment mode, that is, the injection pressure in the weft insertion main nozzle 1 and the injection pressure in the weft insertion main nozzle groups 2 to 5 are Pm2 and Ps2. The detected weft tip arrival time is sequentially displayed as θ. The control computer C2 controls the injection pressure in a direction to converge the detected weft tip arrival time θ to the reference weft tip arrival time, and in the early stage of the trial weaving stage, θ, Pm2, and Ps2 fluctuate in a direction that brings about a stable weft insertion state. To transition from the trial weaving stage to the weaving stage, switch the mode changeover switch 17 from the adjustment mode to the operation mode when the fluctuations in the detected values θ, Pm2, and Ps2 on the detection mode screen G2 have almost disappeared. carried out by By this switching operation, the detection mode screen G2 is switched to the driving mode screen G3, and the control elements α2, β2, γ2, Pm2 on the driving mode screen G3 are
, (Pm2 - ΔPm2 ), (Pm2 + ΔPm2
), Ps2, (Ps2 - ΔPs2 ), (Ps2
+ΔPs2) is selected and set. That is, the control element for the adjustment mode (for trial weaving) is automatically switched to the control element for the operation mode (for weaving) by the switching device of the mode changeover switch 17 from the adjustment mode to the operation mode. At this time, the reference injection pressure in the weft insertion main nozzle 1 and the reference injection pressure in the weft insertion auxiliary nozzle groups 2 to 5 are set based on the actual detected pressures Pm2 and Ps2 when the mode changeover switch 17 is switched. Such a simple switching operation of the mode switching switch 17 makes it extremely easy to switch and set the control elements for controlling the injection pressure, which greatly contributes to improving the operating rate of the jet loom, which is a high-speed loom.

Note that the control pressure change width α in the adjustment mode
1 is larger than the control pressure change width α2 in the operation mode, which is based on the appropriate reference pressure Pm2, Ps2.
This is to obtain the information quickly. Further, the difference β1 in the adjustment mode is smaller than the difference β2 in the operation mode. This is to find more accurate reference injection pressures Pm2 and Ps2. Furthermore, the number of samplings α1 in the adjustment mode is set to a much smaller value than the number of samplings α2 in the operation mode. This is also an appropriate injection pressure Pm2, Ps2
This is to quickly find out.

[0017] In the above embodiment, the number of samples and the differences β1 and β2 at the time of arrival at the weft tip are different between the adjustment mode and the operation mode, but an embodiment in which only one of them is different is also possible. It is. 7 and 8 are flowcharts showing a mode switching program for injection pressure control according to the second invention. In this case, the following algorithm is added to the mode switching program for injection pressure control of the previous embodiment. That is, when the reference pressure is changed and set in the operating mode, the operating mode is automatically switched to the adjustment mode. Furthermore, when the weft tip arrival timing is within the allowable range for a predetermined sampling number of consecutive times and the detected pressure is stable, the adjustment mode is automatically switched to the operation mode. Such automatic mode switching allows for a more accurate transition from the trial weaving stage to the weaving stage.

[0018]

Effects of the Invention As detailed above, in the first invention, the injection pressure setting means is given the function of selecting and setting control elements for injection pressure control by switching the changeover switch. The injection pressure control suitable for the trial weaving stage and the weaving stage can be performed with only the simple operation of switching, and the effect is that the trial weaving stage can be smoothly transitioned to the weaving stage without any complicated operations.

Further, in the second invention, when the weft tip arrival time of a certain number of samples in the trial weaving stage reaches a predetermined fluctuating state in which the weft tip arrival time is within the permissible range and there is almost no fluctuation in the detected injection pressure, the process starts from the trial weaving stage. Since the weaving stage is automatically shifted, an excellent effect is achieved in that the weaving stage can be accurately shifted to the weaving stage without any switching operation.

[Brief explanation of the drawing]

FIG. 1 is a combination diagram of a weft insertion device and a pressure control circuit.

FIG. 2 is a screen diagram showing an adjustment mode.

FIG. 3 is a screen diagram showing a detection mode.

FIG. 4 is a screen diagram showing operation modes.

FIG. 5 is a flowchart representing a mode switching program of the first invention.

FIG. 6 is a flowchart representing a mode switching program of the first invention.

FIG. 7 is a flowchart representing a mode switching program according to a second invention.

FIG. 8 is a flowchart representing a mode switching program according to the second invention.

[Explanation of symbols]

1 main nozzle for weft insertion, 2 auxiliary nozzle group for weft insertion, 6 weft detector as means for detecting time of weft tip arrival, 9, 10 electric pressure control valve as means for regulating injection pressure, 13, 14 pressure detector,
C2 Control computer as injection pressure setting means; 17 Mode changeover switch as switching means.

Claims (2)

[Claims] [Claim 1] A jet loom that inserts a weft by the jet action of a weft insertion nozzle and controls the jet pressure in the weft insertion nozzle based on information on the detected tip arrival time of the weft. a weft tip arrival time detection means for detecting the weft tip arrival time; a pressure detection means for detecting the injection pressure in the weft insertion nozzle; and a pressure detection means for detecting the injection pressure at the weft insertion nozzle; Injection pressure setting means stores control elements for injection pressure control in the trial weaving stage and control elements for injection pressure control in the weaving stage, and also stores detected injection pressure; It consists of an injection pressure adjusting means for adjusting the pressure, and a switching means for selecting one of the control elements in the trial weaving stage and the weaving stage, and the control element in either the trial weaving stage or the weaving stage is selected depending on the operation of the switching means. A pressure control device for weft insertion in a jet loom, wherein the injection pressure setting means is provided with a function of selecting one control element and setting the pressure detected during this operation as a reference pressure. [Claim 2] In a jet room that inserts the weft yarn by the jetting action of the weft insertion nozzle and controls the jetting pressure in the weft insertion nozzle based on information on the detected tip arrival time of the weft yarn, the weft tip arrival time is determined. A pressure detection means detects the injection pressure at the weft insertion nozzle, and a test method such as the number of samples for the detected weft tip arrival time, the control pressure change range, or the allowable upper and lower limits of the injection pressure. A control element for controlling the injection pressure in the weaving stage and an injection setting means for storing the control element for controlling the injection pressure in the weaving stage and the detected injection pressure, and an injection pressure setting means for storing the detected injection pressure; and a control element in the weaving stage when a predetermined number of sampled weft tip arrival times in the trial weaving stage are within the allowable range and the degree of fluctuation in the detected jet pressure reaches a predetermined fluctuation state. A pressure control device for weft insertion in a jet loom, wherein the jet loom is provided with a function of selecting the pressure detected at the time of selection and setting the detected pressure at the time of selection as a reference pressure.