JPH05287641A - Method for controlling jetting of nozzle in fluid jet type loom and its apparatus - Google Patents

Abstract

PURPOSE:To reduce defective picking caused by entarglement of weft yarn tips by normal jetting under a low pressure in a multicolored loom equipped with a normal low-pressure jetting function. CONSTITUTION:A main jetting circuit, the first always low-pressure jetting circuit and the second always low-pressure jetting circuit under a lower pressure than that of the first always low-pressure jetting circuit are connected through a circuit changeover mechanism to each of the main nozzles (N1) and (N2). The respective main nozzles are selectively connected to the main jetting circuit and the first always low-pressure jetting circuit in picking and to the second always low-pressure jetting circuit in nonpicking. Thereby, the main nozzle (N1) in a nonpicking state is made to carry out always low-pressure jetting under a lower pressure than that of the main nozzle (N2) in a picking state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant low-pressure injection control technique for a main nozzle in a non-weft insertion state in a multicolor loom having two or more main nozzles arranged in parallel and having a constant low-pressure injection function. It is a thing.

[0002]

2. Description of the Related Art In a loom having a low-pressure jetting function, low-pressure jetting is always performed from a main nozzle regardless of whether the loom is operated or stopped. With such constant low-pressure jetting, (1) it is possible to prevent the weft from slipping out of the main nozzle due to rocking of the reed, (2) the attitude of the weft before weft insertion can be stabilized, and weft insertion becomes stable, and ( 3) It is possible to prevent the weft from falling out of the main nozzle due to the bouncing back of the weft when the weft is cut.

[0003]

However, when the low-pressure jet is always performed in this way, the weft yarn in the main nozzle is stretched and protrudes from the nozzle outlet. Since the length of the weft yarn tip portion protruding in this way is quite large, in the case of a multi-color weaving machine, the weft yarn tip portions protruding from the adjacent main nozzles may become entangled with each other, resulting in weft insertion failure.

An object of the present invention is to reduce the weft insertion failure due to the entanglement of the weft end portion due to the constant low-pressure jet in the multi-color weaving machine having the constant low-pressure jet function.

[0005]

Therefore, in the present invention, the main injection circuit, the first constant low-pressure injection circuit, and the second constant low-pressure injection circuit having a lower pressure than the main injection circuit are connected to each main nozzle via a circuit switching mechanism. The main nozzles are connected to the main injection circuit and the first constant-pressure low-pressure injection circuit, and those that are not inserted are connected to the second constant-low-pressure injection circuit. The gist of the invention is that the main nozzle in the non-weft insertion state always performs low pressure injection at a lower pressure than the main nozzle in the weft insertion state. Here, "in the weft insertion state" is meant to include sub-H and a predetermined period before and after the main injection period for weft insertion.

[0006]

When the main nozzle is in the non-weft insertion state, the low pressure injection is always performed at a lower pressure than that of the normal constant low pressure injection, so that the protrusion of the weft yarn tip portion becomes small.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the injection mode of the main nozzle in the first example of the method of the present invention. This is a color weaving machine with two main nozzles N1 and N2.
The horizontal axis shows the crank angle of the loom. In the figure, MB indicates the main injection which is the injection for weft insertion. P0 is the main injection pressure, P1 is the first constant low pressure injection pressure and P2
Indicates the second constant low pressure injection pressure. Here, there is a relationship of P0>P1> P2 between these pressures.

In the first main nozzle N1, low pressure injection is always performed at the pressure P1 in the weft insertion cycle. In the meantime, in the second main nozzle N2 in the non-weft insertion cycle, the low pressure injection is always performed at the pressure P2 lower than this. After that, when the first main nozzle N1 enters the non-weft insertion cycle, the low pressure injection is always performed at the low pressure P2. Second time in the weft insertion cycle during this time
In the main nozzle N2, the low pressure injection is always performed at the pressure P1. That is, the main nozzle in the non-weft insertion state always performs low-pressure injection at a lower pressure than the main nozzle in the weft insertion state. In the case of the illustrated example, the switching of the low pressure injection pressure is always performed at a crank angle of 0 °.

FIG. 2 shows an injection mode of the main nozzle in another example of the method of the present invention. The injection mode is basically the same as that shown in FIG. 1, but in the previous embodiment, the switching of the low pressure injection pressure in both main nozzles is always performed at the same point (that is, crank angle 0 °). On the other hand, in this embodiment, the switching timing is shifted. This takes into account the prevention of nozzle omission due to the bouncing back when cutting the weft and the preceding injection for adjusting the weft posture before starting the weft insertion. That is, the weft-inserted weft is cut early in the next cycle. C in the figure indicates the time point when the weft is cut. At this time, in order to prevent the nozzle from missing due to the weft return, the constant low pressure injection at the higher pressure P1 is extended until after the weft cutting in the next weft inserting cycle. Further, the constant low-pressure injection at the higher pressure P1 for adjusting the weft posture before starting the weft insertion is sufficient for the preceding period sufficient for adjusting the weft posture, and no longer preceding period is required. Therefore, the lower pressure P
The continuous low-pressure injection in 2 is extended until a sufficient preceding period in the next weft insertion cycle. Considering these points, the switching point of the low pressure injection pressure is always determined.

The switching time may be shifted so that there is a period in which the low pressure P2 of both the low pressure injections of the main nozzles N1 and N2 is lower, but there is a period in which both are higher pressure P1. It is not preferable to shift as described above. This is because the main purpose of the present invention is to prevent the entanglement of the front end portion of the weft, and therefore entanglement occurs at the pressure P1, which is against this purpose.

FIG. 3 shows an example of the device of the present invention, in which the main injection circuit, the first constant low pressure injection circuit and the second constant low pressure injection circuit having a lower pressure than that are switched. It is connected to each main nozzle via a mechanism.

The main injection circuit has a regulator 10 connected to a pressure source PS, a tank 30, and an opening / closing valve 20. The first constant low-pressure injection circuit has a regulator 11 connected to a pressure source PS and an opening / closing valve 21.
The second constant low-pressure injection circuit has a regulator 12 connected to a pressure source PS and an opening / closing valve 22. The first and second constant low-pressure injection circuits are provided with check valves for preventing backflow of high-pressure fluid from the main injection circuit. The inner opening / closing valves 20, 21 and 22 constitute the circuit switching mechanism. The mode of switching is as described above. Each regulator 10, 11 and 1
2 output pressures P0, P1 and P2 are P0>
There is a relationship of P1> P2. Also regulators 11 and 1
2 may be replaced with a throttle valve.

However, it is not always necessary to provide two low pressure injection circuits for each main nozzle. That is, as shown in FIG. 4, it is also possible to provide pressure control valves 40a and 40b as one system for each main nozzle, and change the output pressure of these to P1 or P2 by an external signal S. This makes it possible to omit the on-off valves 21 and 22 for constant low-pressure injection. Of course, instead of the pressure control valve, a throttle control valve whose amount of throttle can be changed by an external signal may be used.

[0014]

EFFECTS OF THE INVENTION It is possible to prevent the entanglement of the weft yarn end portions and to prevent the weft yarn from missing. That is, the main nozzle in the non-weft insertion state is subjected to the constant low-pressure injection having a pressure lower than the normal constant low-pressure injection pressure that does not come off due to the rocking of the reed, so that the weft yarn nozzle omission can be reliably prevented. Moreover, since the protrusion of the weft tip portion from the main nozzle can be made small, it is possible to prevent the weft tip portions from being entangled with each other and also to save energy.

[Brief description of drawings]

FIG. 1 is a timing diagram showing an injection mode of a main nozzle in an example of the method of the present invention.

FIG. 2 is a timing diagram showing an injection mode of a main nozzle in another example of the method of the present invention.

FIG. 3 is a circuit configuration diagram showing an example of an apparatus of the present invention.

FIG. 4 is a circuit configuration diagram showing a part of another example of the device of the present invention.

[Explanation of symbols]

 10, 11, 12 Regulator 20, 21, 22 Open / close valve 30 Tank N1, N2 Main nozzle PS Pressure source MB Main injection C Weft cutting point P0, P1, P2 Injection pressure

Claims (2)

[Claims] 1. A multicolor loom having a constant low-pressure jetting function from a main nozzle, wherein a constant low-pressure jet of a main nozzle in a non-weft insertion state is performed at a lower pressure than a constant low-pressure jet of a main nozzle in a weft insertion state. A method for injecting a nozzle of a fluid injection type loom, comprising: 2. A multicolor loom having a constant low pressure jetting function from a main nozzle, wherein a main jetting circuit, a first constant low pressure jetting circuit, and a second constant low pressure jetting circuit having a lower pressure than the main jetting circuit form a circuit switching mechanism. The main nozzles are connected to each main nozzle via the main injection circuit and the first constant low pressure injection circuit when in the weft insertion state, and the second constant low pressure injection when the main nozzle is not in the weft insertion state. A nozzle injection device for a fluid injection type loom, which is selectively connected to a circuit.