JP5027064B2 - Weft insertion method in jet loom - Google Patents

Description

The present invention relates to a weft Inserting method in a jet loom in which the weft emitted from the main nozzle weft insertion is weft insertion by pulling by the air jet of the auxiliary nozzle weft insertion.

  In a jet loom in which wefts injected from a weft insertion main nozzle are pulled by air injection from an auxiliary nozzle for weft insertion, it is desired to perform stable weft insertion and reduce air consumption. The techniques disclosed in Patent Documents 1 to 6 are techniques for achieving stable weft insertion or reducing air consumption.

Patent Document 1 discloses a technique for improving the shape of the injection hole of the auxiliary nozzle for weft insertion.
Patent Document 2 discloses a technique for switching the injection pressure of the main nozzle for weft insertion to a low pressure when the tip of the weft is pulled by the injection fluid from the first auxiliary nozzle for weft insertion or thereafter. ing.

Patent Document 3 discloses a technique for controlling the injection period and the injection timing of the main nozzle for weft insertion and the auxiliary nozzle for weft insertion in real time.
Patent Document 4 discloses a technique related to the shape of the weft guide hole formed in the deformed rod and the arrangement of the auxiliary nozzle for weft insertion.

Patent Document 5 discloses a technique for giving moderate weft to a weft between a contact-type or nip-type weft pulling device and a main nozzle for weft insertion.
Patent Document 6 discloses a technique for lowering the injection pressure of the main nozzle for weft insertion by a constant pressure from the injection pressure of the auxiliary nozzle for weft insertion.

As disclosed in Patent Documents 2 and 6, the technique of setting the injection pressure of the main weft insertion nozzle to be lower than the injection pressure of the auxiliary auxiliary nozzle for nozzle insertion contributes to stable weft insertion.
Japanese Patent Laid-Open No. 3-97939 Japanese Patent Laid-Open No. 6-123041 JP-A-6-257034 JP-A-8-74143 Japanese Patent Laid-Open No. 8-113850 Japanese Patent Laid-Open No. 11-12891

  The inventor of the present application investigated changes in weft insertion characteristics when the weft supply speed by the main weft insertion nozzle and the weft conveyance speed by the auxiliary weft insertion nozzle were changed. The graph in FIG. 13 shows the results of investigating the change in the weft insertion characteristics. The horizontal axis on the upper side represents the injection pressure of the auxiliary nozzle for weft insertion, and the vertical axis on the right side represents the injection pressure of the main nozzle for weft insertion. The left vertical axis represents the weft insertion speed (flying speed of the weft), and the lower horizontal axis represents the air consumption. Black dots in the graph indicate measured data.

  A waveform V in the graph of FIG. 12 indicates an injection pressure waveform of the weft insertion auxiliary nozzle. With respect to the present ideal setting of the weft supply speed by the main nozzle for weft insertion and the weft conveyance speed by the auxiliary nozzle for weft insertion (black point N1 in the graph of FIG. 13), the injection pressure of the main nozzle for weft insertion is By increasing the weft supply capacity and lowering the injection pressure of the auxiliary nozzle for weft insertion (for example, the black point N2 in the graph of FIG. 13) to suppress the weft conveyance capacity, weft insertion is performed with increased weft looseness. . FIG. 13 shows that the average weft insertion speed does not change from the current ideal setting if the weft feeding capacity is suppressed while increasing the weft supply capacity with respect to the current ideal setting. It brings the knowledge that consumption can be reduced from the current level.

  When weft insertion is performed by increasing the looseness of the weft, the injection pressure of the auxiliary nozzle for weft insertion is set lower than the current ideal setting, so that the air flow in the weft guide passage is reduced. The average speed is about the same as the weft transport speed. In this situation, the inventor of the present application has found that the amount of bending of the tip of the weft Y that is injected from the main nozzle 14 for weft insertion and being conveyed in the weft guide passage as shown in FIG. It was. A significant increase in the amount of bending of the weft tip portion results in a delay in the arrival time of the weft tip to the weft insertion end (weave end), and a weft insertion error tends to occur.

  An object of the present invention is to further reduce the air consumption while stabilizing the weft insertion.

The invention of claim 1 is directed to a weft insertion method in a jet loom in which wefts injected from a main nozzle for weft insertion are pulled by air injection of an auxiliary nozzle for weft insertion and are inserted. The injection pressure during the air injection period of the auxiliary nozzle for weft insertion is switched from the high pressure state in the first half to the low pressure state in the second half, and the air injection flow velocity in the high pressure state is the average air flow velocity in the weft guide passage with respect to the weft conveyance speed. The rate of increase is greater than the weft transport speed in the range of 10% to 20%, the air injection flow rate in the low pressure state is smaller than the weft transport speed, and 40% to 60% of the air pressure in the high pressure state. The speed corresponding to the air pressure .

  In the first half of the weft insertion auxiliary nozzle during the air injection period, the weft tip is exposed to a high injection pressure and straightened, so that stable weft insertion is performed. In the second half of the air injection period, since the injection pressure of the weft insertion auxiliary nozzle is lowered, the air consumption is reduced.

In addition, such setting of the air injection flow rate improves the flying posture of the weft tip and further reduces the air consumption.

  The present invention has an excellent effect that the air consumption can be further reduced while stabilizing the weft insertion.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 2A, reference numeral 11 denotes a winding type weft length measuring storage device, and the weft Y is wound around the yarn winding surface 111 by the rotation of the yarn winding tube 110. Unwinding and unwinding of the weft thread from the bobbin winding surface 111 is controlled by the protruding and retracting operation of the locking pin 121 of the electromagnetic solenoid 12. Excitation demagnetization of the electromagnetic solenoid 12 is performed by command control of the control computer C, and the control computer C controls the excitation demagnetization of the electromagnetic solenoid 12 based on the weft unwinding detection information from the weft unwinding detector 13. The weft unwinding detector 13 detects the unwinding of the wound yarn on the thread winding surface 111.

  As shown in FIG. 1A, the weft insertion auxiliary nozzle group 15 attached to the sley 36 injects air into the weft guide passage 371 of the deformation rod 37 on the sley 36. FIG. 1B shows a weft insertion auxiliary nozzle group 15. The weft insertion auxiliary nozzle group 15 injects air from the injection hole 38.

  As shown in FIG. 2A, in this embodiment, a plurality of groups of weft insertion auxiliary nozzle groups 15 to 18 (8 groups in this embodiment, but only four groups are shown) are used. The weft Y drawn and ejected from the yarn winding surface 111 by the injection action of the insertion main nozzle 14 is inherited by the relay air injection of the plurality of auxiliary insertion groups 15, 16, 17, and 18 for weft insertion. Hereinafter, all the weft insertion auxiliary nozzle groups will be referred to as weft insertion auxiliary nozzle groups 15 to 18.

  When the weft insertion is performed satisfactorily, the weft Y is detected by the weft detector 19 within a predetermined machine base rotation angle range. The weft presence / absence detection signal from the weft detector 19 is input to the control computer C, and the control computer C selects either continuation or stop of the loom operation based on the weft presence / absence detection signal.

  The weft insertion main nozzle 14 is connected to the air supply tank 29 via the supply path 32 and the electromagnetic on-off valve 20. The weft insertion auxiliary nozzle groups 15 to 18 are connected to an air supply tank 30 as a first air supply source via a supply path 33 and electromagnetic open / close valves 21, 22, 23 and 24. The weft insertion auxiliary nozzle groups 15 to 18 include a part of the supply path 33, a supply path 34 that joins the supply path 33, a check valve 35 on the supply path 34, and electromagnetic on-off valves 25, 26, 27, 28. Is connected to an air supply tank 31 as a second air supply source.

  The electromagnetic on-off valves 21 to 24 supply air from the air supply tank 30 to the weft insertion auxiliary nozzle groups 15 to 18 and supply air from the air supply tank 30 to the weft insertion auxiliary nozzle groups 15 to 18. It is the 1st switching valve switched to the stop state which stops.

  The electromagnetic on-off valves 25 to 27 supply air from the air supply tank 31 to the weft insertion auxiliary nozzle groups 15 to 18 and supply air from the air supply tank 31 to the weft insertion auxiliary nozzle groups 15 to 18. It is the 2nd switching valve switched to the stop state which stops.

  Open / close control of each of the electromagnetic open / close valves 20 to 28 is performed according to a command from the control computer C. The control computer C controls the opening / closing of the electromagnetic on-off valves 20 to 28 based on the loom rotation angle detection information obtained from the rotary encoder 42 for detecting the loom rotation angle.

  Each air supply tank 29, 30, 31 is connected to a source pressure tank (not shown) via a pressure control valve 43, 44, 45. The pressure control valve 43 is for adjusting the pressure of the air supply tank 29. The pressure control valve 44 is for adjusting the pressure of the air supply tank 30, and the pressure control valve 45 is for adjusting the pressure of the air supply tank 31. The pressure of the air supply tank 30 is higher than the pressure of the air supply tank 31.

  FIG. 3 is a timing chart showing the injection pressure waveforms in the weft insertion main nozzle 14 and the weft insertion auxiliary nozzle groups 15-18. The horizontal axis represents time T, and the vertical axis represents the tip arrival position (weft insertion position) of the weft thread inserted. The horizontal axis is obtained by replacing a part of the angular range of one rotation of the loom (range of crank angle 360 °) with time display.

  A curve M represents the injection pressure waveform of the main nozzle 14 for weft insertion, and the curves E1, E2, E3, E4, E5, E6, E7, and E8 represent the injection pressure waveforms of the auxiliary nozzle groups 15 to 18 for weft insertion. . The timing α represents the timing at which the wound yarn on the thread winding surface 111 starts to be released from the locking action of the locking pin 121, and the timing β is related to the weft drawn from the thread winding surface 111 by the locking pin 121. Indicates the timing to stop. Line D shows an example of the flying state of the weft Y. Hereinafter, the curves E1 to E8 are referred to as injection pressure waveforms E1 to E8.

  The air injection in one group (for example, the weft insertion auxiliary nozzle group 15) of the weft insertion auxiliary nozzle groups 15 to 18 will be described. T in FIG. 3 represents the excitation period of the electromagnetic on-off valve 21, that is, the air injection period in the weft insertion auxiliary nozzle group 15.

  The control computer C excites the electromagnetic on-off valve 21 shortly before the tip of the weft Y passes through the weft insertion auxiliary nozzle group 15. The electromagnetic on-off valve 21 is excited to be opened, the air in the air supply tank 30 is supplied to the weft insertion auxiliary nozzle group 15, and the weft insertion auxiliary nozzle group 15 injects air at the pressure of the air supply tank 30. Start. The injection pressure in the weft insertion auxiliary nozzle group 15 is highest when the tip of the weft Y passes through the position of the weft insertion auxiliary nozzle group 15.

  F shown in FIG. 2A indicates the travel path of the weft Y. L1 is the weft insertion auxiliary nozzle group 15A, 15B, 15C, 15D constituting the weft insertion auxiliary nozzle group 15, and the tip of the weft Y is in the injection directing region (indicated by arrow R1) of the weft insertion auxiliary nozzle 15A. Indicates the weft insertion position expected to reach. L2 is an injection directing region (an arrow R2) of a weft insertion auxiliary nozzle 15D farthest from the weft insertion main nozzle 14 among the weft insertion auxiliary nozzles 15A, 15B, 15C, 15D constituting the weft insertion auxiliary nozzle group 15. Shows the weft insertion position where the tip of the weft Y is expected to reach.

  A waveform W in the graph of FIG. 2B represents an injection pressure waveform in the auxiliary nozzle group 15 for weft insertion. γ is a timing at which the tip of the weft Y is expected to reach the weft insertion position L1, and δ is a timing at which the tip of the weft Y is expected to reach the weft insertion position L2. The injection pressure in the weft insertion auxiliary nozzle group 15 becomes the pressure of the air supply tank 30 from timing γ to timing δ.

  After the leading end of the weft Y passes the position of the weft insertion auxiliary nozzle group 15, that is, after the leading end of the weft Y passes the weft insertion position L2, the control computer C demagnetizes the electromagnetic on-off valve 21 and The on-off valve 25 is excited. That is, the control computer C demagnetizes the electromagnetic on-off valve 21 and synchronizes with the electromagnetic on-off valve 25 in accordance with the expected passage timing at which the tip of the weft Y is expected to pass through the injection directing region R2 of the weft insertion auxiliary nozzle group 15. Is excited. The electromagnetic on-off valve 21 is demagnetized to be in a closed state, and the electromagnetic on-off valve 25 is excited to be in an open state. When the electromagnetic on-off valve 21 is closed, the injection pressure in the weft insertion auxiliary nozzle group 15 gradually decreases, and when the injection pressure in the weft insertion auxiliary nozzle group 15 falls below the pressure of the air supply tank 31, The stop valve 35 opens. Thus, the air in the air supply tank 31 is supplied to the weft insertion auxiliary nozzle group 15 via the electromagnetic on-off valve 25, and the weft insertion auxiliary nozzle group 15 injects air with the pressure of the air supply tank 31.

  When the air injection period T has elapsed since the excitation of the electromagnetic opening / closing valve 21, the control computer C demagnetizes the electromagnetic opening / closing valve 25. The electromagnetic on-off valve 25 is demagnetized and closed, air supply from the air supply tank 31 to the weft insertion auxiliary nozzle group 15 is stopped, and air injection in the weft insertion auxiliary nozzle group 15 is stopped.

The same air injection is performed for the other weft insertion auxiliary nozzle groups 16 to 18 within the air injection period of each weft insertion auxiliary nozzle group 16 to 18.
The control computer C controls the electromagnetic open / close valves 21 to 24 and the electromagnetic open / close valves 25 to 25 so that the injection pressure during the air injection period in the weft insertion auxiliary nozzle groups 15 to 18 is switched from the high pressure state of the first half to the low pressure state of the second half. 28 is a control means for controlling the switching state with 28.

  The waveform portions E11, E21, E31, E41, E51, E61, E71, and E81 of the injection pressure waveforms E1 to E8 are inserted when the electromagnetic on-off valves 21 to 24 are open, that is, the air in the air supply tank 30 is inserted. This represents the injection pressure when being supplied to the auxiliary nozzle groups 15 to 18. Waveform portions E12, E22, E32, E42, E52, E62, E72, and E82 of the injection pressure waveforms E1 to E8 are when the solenoid on-off valves 25 to 28 are open, that is, the air in the air supply tank 31 is inserted. This represents the injection pressure when being supplied to the auxiliary nozzle groups 15 to 18. The injection pressure during the air injection period (only the air injection period T of the weft insertion auxiliary nozzle group 15 is shown in the figure) in the weft insertion auxiliary nozzle groups 15 to 18 is in two stages from the first half high pressure state to the second half low pressure state. Switch to. The injection pressure waveforms E1, E2, E3, and E4 are two-stage injection pressure waveforms that consist of the first half high pressure injection and the second half low pressure injection.

  The weft insertion auxiliary nozzle groups 15 to 18 perform two-stage injection pressure relay injection indicated by injection pressure waveforms E1 to E8 in accordance with the flying position of the tip of the weft Y, and are injected from the main insertion nozzle 14 for weft insertion. The weft Y is pulled toward the weft insertion end by the relay injection at the two-stage injection pressure.

  The period of the high pressure injection in the first half varies depending on the number of auxiliary nozzles for weft insertion (four in this embodiment) connected per electromagnetic valve. That is, the smaller the number of auxiliary nozzles for weft insertion connected per electromagnetic valve, the shorter the high-pressure injection period. The higher the number of auxiliary nozzles for weft insertion connected per electromagnetic valve, the higher the pressure. The injection period becomes longer.

In the first embodiment, the following effects can be obtained.
(1) When the injection pressure of the main nozzle 14 for weft insertion is increased to increase the weft supply capacity, the weft Y is loosened as shown in FIG. However, according to the air injection in which the injection pressure during the air injection period T in the auxiliary nozzle groups 15 to 18 for weft insertion is switched in two stages from the high pressure state in the first half to the low pressure state in the second half, the tip of the weft Y is It is exposed to the high injection pressure which is the pressure of the supply tank 30, and is straightened as shown in FIG. In the latter half of the air injection period T, the injection pressure of the weft insertion auxiliary nozzle groups 15 to 18 is set to a low injection pressure that is the pressure of the air supply tank 31 lower than the pressure of the air supply tank 30. Therefore, stable weft insertion is performed and air consumption is reduced.

  (2) The pressure in the high pressure injection of the weft insertion auxiliary nozzle groups 15 to 18, that is, the air pressure in the air supply tank 30 is set so that the average air flow rate in the weft guide passage 371 is higher than the weft transport speed. There is a need.

  FIG. 4 is a graph showing the relationship between the increase rate of the average air flow velocity in the weft guide passage 371 and the air consumption with respect to the weft conveyance speed, and the relationship between the increase rate and the bending frequency of 90 ° or more of the front end portion of the weft yarn. It is. The horizontal axis represents the increase rate, the left vertical axis represents the bending frequency, and the right vertical axis represents the air consumption. A line Se indicates a change in air consumption, and a line Ke indicates a bending frequency. The straight line So indicates the current level of air consumption, and the straight line Ko indicates the current level of bending frequency.

  According to the graph of FIG. 4, when the increase rate is in the range of 10% to 20%, the flying posture of the tip of the weft is good. Even if the rate of increase is higher than this range, the bending frequency of the tip of the weft is hardly changed, and the amount of air consumption increases.

  On the other hand, if the pressure in the low pressure injection of the auxiliary nozzle groups 15 to 18 for weft insertion, that is, the air pressure in the air supply tank 31, is set in the range of 40% to 60% of the air pressure in the air supply tank 30, the air consumption amount Stable weft insertion can be performed while reducing the above. When the temperature is lower than this range, the flying stability of the weft Y gradually deteriorates. When the temperature is higher than this range, the reduction rate of the air consumption is reduced.

  Thus, the setting of the air injection flow rate in which the air injection flow rate in the high pressure state is made faster than the speed of the front end of the weft Y and the air injection flow rate in the low pressure state is made slower than the speed of the front end of the weft Y is The flying posture of the tip of the weft is improved, and the air consumption can be reduced.

Next, a second embodiment of FIGS. 6 to 10 will be described. The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
As shown in FIG. 6, in the second embodiment, a sub-chamber former 39 for pressure accumulation is used instead of the air supply tank 31 and the electromagnetic on-off valves 25 to 28 in the first embodiment. The sub chamber forming device 39 is connected to the supply path 33.

  As shown in FIG. 7, the sub chamber forming device 39 includes a sub chamber 391 and an air entrance / exit passage 40, and the sub chamber 391 is located downstream of the electromagnetic on-off valves 21 to 24 via the air entrance / exit passage 40. It is connected to the supply path 33 between the on-off valves 21 to 24 and the weft insertion auxiliary nozzle groups 15 to 18. The air access path 40 has a throttling function. In this embodiment, the passage cross-sectional area of the air access path 40 is set to 0.5 times the total cross-sectional area of the injection hole 38 of the group of auxiliary nozzle groups for weft insertion connected to one electromagnetic on-off valve. Has been. Further, in the present embodiment, the volume of the sub chamber 391 is set to be twice the volume of the entire supply path connected to a group of auxiliary nozzle groups for weft insertion connected to one electromagnetic on-off valve.

  The connection edge 401 of the air inlet / outlet path 40 with respect to the sub chamber 391 is arc-shaped chamfered, and the connection edge 402 of the air inlet / outlet path 40 with respect to the supply path 33 is arc-shaped chamfered.

The air injection in one group (for example, the weft insertion auxiliary nozzle group 15) of the weft insertion auxiliary nozzle groups 15 to 18 will be described.
Shortly before the tip of the weft Y passes through the weft insertion auxiliary nozzle group 15, the control computer C excites the electromagnetic on-off valve 21. The electromagnetic on-off valve 21 is excited to be opened, the air in the air supply tank 30 is supplied to the weft insertion auxiliary nozzle group 15, and the weft insertion auxiliary nozzle group 15 injects air at the pressure of the air supply tank 30. Start. The air in the air supply tank 30 is also supplied to the sub chamber 391 via the air access path 40, and the pressure in the sub chamber 391 increases.

  After the tip of the weft Y passes the position of the weft insertion auxiliary nozzle group 15, the control computer C demagnetizes the electromagnetic on-off valve 21. The electromagnetic on-off valve 21 is demagnetized and closed. When the electromagnetic on-off valve 21 is closed, the injection pressure in the weft insertion auxiliary nozzle group 15 gradually decreases. At the same time, the air in the sub chamber 391 is supplied to the weft insertion auxiliary nozzle group 15 via the air inlet / outlet path 40, and the pressure in the sub chamber 391 begins to gradually decrease. While the injection pressure of the weft insertion auxiliary nozzle group 15 is decreasing, the weft insertion auxiliary nozzle group 15 is in a pressure balance stage where the injection pressure of the weft insertion auxiliary nozzle group 15 becomes substantially the same as the pressure of the sub chamber 391. The injection pressure at is maintained at a substantially constant pressure for a while.

Thereafter, the air remaining in the sub chamber 391 is injected from the weft insertion auxiliary nozzle group 15, the air pressure in the sub chamber 391 is lowered, and the air injection from the weft insertion auxiliary nozzle group 15 ends.
The control computer C in the second embodiment is a control means for switching and controlling the electromagnetic on-off valves 21 to 24 from the supply state to the stop state during the air injection period in the weft insertion auxiliary nozzle groups 15 to 18.

  A waveform Po in the graph of FIG. 8 indicates an injection pressure waveform in the weft insertion auxiliary nozzle group 15, and a waveform Q in the graph of FIG. 8 indicates an air pressure waveform in the sub chamber 391. As is apparent from the graph of FIG. 8, the rise time of the injection pressure in the weft insertion auxiliary nozzle group 15 is almost the same as that of the conventional apparatus (see FIG. 12), and the injection rise time does not increase. On the other hand, the injection pressure drop time in the weft insertion auxiliary nozzle group 15 is about twice as long as that of the conventional apparatus (see FIG. 12) due to the provision of the sub chamber 391.

  The same air injection is performed on the other weft insertion auxiliary nozzle groups 16-18. The weft insertion auxiliary nozzle groups 15 to 18 perform the relay injection of the two-stage injection pressure indicated by the injection pressure waveform Po in accordance with the flying position of the tip of the weft Y and are injected from the main insertion nozzle 14. Y is pulled to the weft insertion end side by the relay injection at the two-stage injection pressure.

In the second embodiment, the following effects can be obtained.
(3) The injection pressure waveform in the weft insertion auxiliary nozzle groups 15 to 18 is a two-stage injection pressure waveform by providing the sub chamber 391, and the weft insertion is kept stable as in the case of the first embodiment. Above, air consumption can be greatly reduced.

  (4) A curve G in the graph of FIG. 9 indicates a cross-sectional area ratio obtained by dividing the passage cross-sectional area in the air in / out path 40 by the total cross-sectional area of the injection hole 38 in one group of the weft insertion auxiliary nozzle groups 15 to 18 And the relationship between the good and bad of the generation state of the two-stage injection pressure waveform. The horizontal axis indicates the cross-sectional area ratio obtained by dividing the passage cross-sectional area in the air inlet / outlet path 40 by the total cross-sectional area of the injection hole 38, and the vertical axis indicates whether the generation state of the two-stage injection pressure waveform is good or bad. Waveforms P1, P2, and P3 in the graph show examples of injection pressure waveforms in the weft insertion auxiliary nozzle groups 15 to 18 when the cross-sectional area ratio is g1, g2, and g3.

  When the cross-sectional area ratio is less than 10%, almost no two-stage injection pressure waveform is generated, and the injection pressure waveforms in the weft insertion auxiliary nozzle groups 15 to 18 are almost the same as when the sub chamber 391 is not provided. When the cross-sectional area ratio exceeds 100%, the rise time of the injection pressure in the weft insertion auxiliary nozzle groups 15 to 18 is significantly increased, and appropriate weft insertion cannot be performed. Therefore, if the cross-sectional area ratio is set in the range of 10% to 100%, it is possible to appropriately generate a two-stage injection pressure waveform that can significantly reduce air consumption while ensuring stable weft insertion.

  (5) A curve H in the graph of FIG. 10 indicates a volume ratio obtained by dividing the volume in the sub chamber 391 by the total volume of the supply path in one of the auxiliary nozzle groups 15 to 18 for weft insertion, and the two-stage injection pressure. The relationship between the waveform generation status and the quality is shown. The horizontal axis shows the volume ratio obtained by dividing the volume of the sub chamber 391 by the total volume of the supply path, and the vertical axis shows the quality of the two-stage injection pressure waveform generation. Waveforms P4, P5, and P6 in the graph show examples of injection pressure waveforms in the weft insertion auxiliary nozzle groups 15 to 18 when the cross-sectional area ratio is h1, h2, and h3.

  When the volume ratio is less than 30%, almost no two-stage injection pressure waveform is generated, and the injection pressure waveforms in the weft insertion auxiliary nozzle groups 15 to 18 are almost the same as the case where the sub chamber 391 is not provided. When the cross-sectional area ratio exceeds 350%, the pressure value on the high-pressure side becomes significantly low, and appropriate weft insertion cannot be performed. In addition, each air injection period in the weft insertion auxiliary nozzle groups 15 to 18 becomes longer than the required weft insertion period, and the effect of reducing the air consumption is reduced.

Therefore, if the volume ratio is set in the range of 30% to 350%, it is possible to generate a two-stage injection pressure waveform that can significantly reduce air consumption while ensuring stable weft insertion.
(6) The configuration in which the connection edges 401 and 402 of the air inlet / outlet path 40 are chamfered in an arc shape reduces separation of the air flow at the connection edges 401 and 402 and suppresses pressure loss.

  (7) The number of electromagnetic on-off valves, pressure control valves, and air supply tanks is halved compared to the case of the first embodiment, and the check valve is not required, so the initial cost can be greatly reduced. it can.

In the present invention, the following embodiments are also possible.
As shown in FIG. 11, the variable throttle mechanism 41 may be provided in the air inlet / outlet path connecting the sub chamber 391 and the supply path 33. In this way, the value of the low pressure injection pressure in the two-stage injection pressure waveform can be easily changed.

O You may employ | adopt the subchamber forming device 39 which can change the volume of a subchamber. In this way, the low pressure injection pressure drop time in the weft insertion auxiliary nozzle can be easily changed.
In the first embodiment, the flying position (the weft insertion) of the weft tip is based on the wound unwinding detection information obtained by the weft unwinding detector 13 that detects the unwinding of the wound yarn on the thread winding surface 111. Position), and the opening / closing timing of the electromagnetic on / off valves 21 to 24 and the electromagnetic on / off valves 25 to 28 may be controlled based on the result of the grasp.

  In the second embodiment, based on the wound unwinding detection information obtained by the weft unwinding detector 13 that detects the unwinding of the wound yarn on the thread winding surface 111, the flying position of the weft tip (weft insertion) Position), and the opening / closing timing of the electromagnetic on-off valves 21 to 24 may be controlled based on the grasping result.

The technical idea that can be grasped from the above-described embodiment will be described below together with the effects thereof.
[1] The increase rate of the average air flow velocity in the weft guide passage with respect to the weft conveyance speed is in the range of 10% to 20%, and the pressure in the low pressure injection is in the range of 40% to 60% of the pressure in the high pressure injection. The

  Stable weft insertion can be performed while reducing air consumption.

1 shows a first embodiment, (a) is a perspective view of a weft insertion device. (B) is a figure of the auxiliary nozzle group for weft insertion. (A) is a schematic diagram of a weft insertion device. (B) is a graph which shows the injection pressure waveform in the auxiliary nozzle group for weft insertion. The timing chart which shows relay injection. The graph which shows the relationship between the increase rate of the air injection flow velocity with respect to the weft speed, air consumption, and the bending frequency of the front-end | tip part of a weft. The figure which shows the flying state of a weft. The schematic diagram of the weft insertion apparatus which shows 2nd Embodiment. The principal part sectional side view which shows the subchamber former 39. FIG. The graph which shows the injection pressure waveform in the auxiliary nozzle group for weft insertion, and the pressure change in the subchamber 391. The graph which shows the relationship between the cross-sectional area ratio which divided the passage cross-sectional area in an air in / out path | route by the total cross-sectional area of the injection hole in 1 group of the auxiliary nozzle group for weft insertion, and the quality of the production | generation state of a two-step injection pressure waveform. The graph which shows the relationship between the volume ratio which divided | segmented the volume in a subchamber with the total volume of the supply path | route in 1 group of the auxiliary nozzle group for weft insertion, and the quality of the production | generation state of a two-step injection pressure waveform. The principal part schematic diagram which shows another embodiment. The graph which shows the conventional air injection pressure waveform in the auxiliary nozzle for weft insertion. The graph which shows the investigation result investigated about the change of the weft insertion characteristic when the weft supply speed by the main nozzle for weft insertion and the weft conveyance speed by the auxiliary nozzle for weft insertion were changed. The figure which shows the bending of the weft front-end | tip part.

Explanation of symbols

  14 ... Main nozzle for weft insertion. 15-18 ... Weft insertion auxiliary nozzle group as auxiliary nozzles for weft insertion. 15A, 15B, 15C, 15D ... Weft insertion auxiliary nozzles. 30: An air supply tank as a first air supply source. 31: An air supply tank as a second air supply source. 21-24 ... Electromagnetic on-off valves as first switching valves. 25 to 28: Electromagnetic on-off valves as second switching valves. 38 ... injection hole. 39: Sub chamber forming device. 391 ... Sub-chamber. 40: Air access route. C: Control computer as control means. Y ... Weft. T: Air injection period.

Claims (1)

In the weft insertion method in the jet loom where the weft injected from the main nozzle for weft insertion is pulled by the air injection of the auxiliary nozzle for weft insertion,
Switching the injection pressure during the air injection period in the weft insertion auxiliary nozzle from the high pressure state of the first half to the low pressure state of the second half ,
The air injection flow rate in the high pressure state is greater than the weft conveyance speed in a range where the increase rate of the average air flow rate in the weft guide passage with respect to the weft conveyance speed is 10% to 20%, and the air injection flow rate in the low pressure state is A weft insertion method in a jet loom that is lower than the weft conveying speed and has a speed corresponding to an air pressure of 40% to 60% of the air pressure in the high pressure state .

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