JPH05272033A - Method for injection through main nozzle in air jet loom - Google Patents

Abstract

PURPOSE:To prevent end breakage of weft and to reduce air consumption by suspending continuous low-pressure injection of air at least in a period of time from a point of time of meshing of weft with an engaging pin to a point of time of end breakage of weft. CONSTITUTION:A continuous low-pressure injection of air from a main nozzle is interrupted at least in a period of time from meshing of weft with an engaging pin to a point of time of end breakage of weft. End breakage resulting from return of twist of weft caused by exposure of weft in the main nozzle to continuous low-pressure injection of air in a state of the weft subjected to drafting force of weft inserting can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for injecting a main nozzle in an air jet room, and more particularly to an improvement in control technology for constant low pressure injection by a main nozzle.

[0002]

2. Description of the Related Art In addition to a main injection for weft insertion, a main nozzle of an air jet room constantly performs a fine injection called low pressure injection. By performing such constant low-pressure jetting, (I) threading can be performed while the loom is stopped without using a dedicated on-off valve, (II) weft removal from the main nozzle due to rocking of the reed. Preventable, (III)
The weft can be prevented from slipping out of the main nozzle due to the bouncing of the weft when cutting the weft, and (IV) the weft posture before weft insertion can be stabilized, and the weft insertion is stable.

[0003]

However, if constant low-pressure injection is adopted in this way, another problem arises.
After the main nozzle completes the main injection, the weft thread is engaged with the locking pin and restrained. After that, until the weft is cut, the weft in the main nozzle is constantly exposed to the low-pressure jet under the traction force of the weft inserted. Since the pulling force is acting during this time, the twist of the weft yarn is likely to return and eventually the yarn is broken.

However, after the weft has been cut by the cutter, the weft inside the main nozzle becomes free at the opening side of the main nozzle, and the pulling force from the weft inserted into the main nozzle does not act on it. After the traction force disappears in this manner, even if the yarn is constantly exposed to the low-pressure jet and some twist occurs, the yarn is hardly broken.

An object of the present invention is to provide an air jet loom in which low pressure injection is constantly performed from a main nozzle,
The purpose of this is to prevent yarn breakage due to untwisting during the period from the completion of the main injection to the cutting of the weft.

[0006]

Therefore, the gist of the present invention is to constantly interrupt the low-pressure injection at least during the period from the engagement of the weft and the engaging pin to the weft cutting.

[0007]

[Action]

The low-pressure jet does not always act on the weft while it is under the action of the traction force of the weft in which the weft is inserted.

【Example】

1 to 5, the horizontal axis represents the crank angle, P represents the time when the weft thread is engaged with the locking pin, and C represents the time point when the weft thread is cut. MB indicates main injection (main blow),
Further, CB indicates a cutting jet (cutting blow) for preventing the weft from falling out when the weft is cut. Also, the shaded portion in the figure indicates that the low-pressure injection is always interrupted.

FIG. 1 shows a first embodiment of the present invention, in which the low-pressure injection is interrupted at all times from a time point P when the weft thread engages with the locking pin to a weft cutting time point C.
This is because this period is a period in which the weft yarn in the main nozzle receives a strong traction force from the weft yarn in which the weft yarn is inserted.

FIG. 2 shows a second embodiment of the present invention, in which the low-pressure injection is interrupted for a period from the time when the main injection is completed to the time C when the weft is cut. This is the first
This is because the weft yarn in the main nozzle receives a large amount of traction force from the weft yarn inserted in the main nozzle during the period from the time point when the main injection is completed to the engagement time point P, though it is not as long as the time period in the embodiment.

FIG. 3 shows a third embodiment of the present invention, in which the low pressure injection is always interrupted during the period from the start of the main injection to the cutting of the weft. This is adopted from the viewpoint of energy saving because the low-pressure injection is always unnecessary from the start to the end of the main injection.

In the above embodiments, the loom not having the cutting and jetting function has been described. However, in the case of the loom having this function, as shown in FIG. Instead of "until weft cutting", it means "until the end of cutting injection". That is, the expression “up to weft cutting” in this invention is used in this concept.

FIG. 5 shows an example in which the control method shown in FIG. 4 is applied to a two-color weave using two wefts. For the selected weft yarn I or II, the low-pressure injection is interrupted at least for at least the period from the engagement point P to the weft cutting point C.

FIG. 6 shows an example of an apparatus for carrying out the method of the present invention, which is used in a two-color weaving machine having a cutting and jetting function. Pressure source PS and main nozzle N
Three types of circuits are configured between 1 and N2, and the main injection circuit has a regulator 21, a tank 23, and an opening / closing valve 22. The low-pressure injection circuit always has a regulator 11, an on-off valve 12, and a check valve 13.
In addition, the cutting injection circuit has a regulator 31 and an on-off valve 32.
And a check valve 14. Regulator 1
Throttle valves 1 and 31 may be used.

[0016]

The low-pressure jet does not always act on the weft while the weft in which the weft is inserted is under the action of traction force. Therefore, it is possible to effectively prevent the weft from being untwisted during this period, and eventually the weft to break. Since the low-pressure injection is constantly applied during the remaining period, the advantage of the low-pressure injection itself can be fully exerted. In addition, since the consumption of air can be reduced, energy can be saved accordingly.

[Brief description of drawings]

FIG. 1 is a timing diagram showing a constant low pressure injection control state in a first embodiment of the present invention.

FIG. 2 is a timing diagram showing a constant low pressure injection control state in the second embodiment of the present invention.

FIG. 3 is a timing diagram showing a constant low pressure injection control state in a third embodiment of the present invention.

FIG. 4 is a timing diagram showing a constant low-pressure injection control state when the third embodiment is carried out on a loom equipped with a cutting injection function.

FIG. 5 is a timing diagram showing a constant low-pressure injection control state when the control method of the third embodiment is applied to a two-color weave.

FIG. 6 is a circuit diagram showing an example of an apparatus for carrying out the method of the present invention.

[Explanation of symbols]

 PS Pressure source N Main nozzle 11 Regulator 12 Open / close valve

Claims (4)

[Claims] 1. An air jet which constantly interrupts low-pressure injection at least during a period from an engagement point between a weft thread and a locking pin to a weft cutting point in an air jet room in which low-pressure injection is always performed from a main nozzle. Main nozzle injection method in room. 2. The method according to claim 1, wherein the low-pressure jet is constantly interrupted during the period from the time when the weft thread is engaged with the locking pin to the time point when the weft thread is cut. 3. The low-pressure injection is interrupted for a period from the time when the main injection is completed to the time when the weft is cut.
The method described in. 4. The method according to claim 1, wherein the low-pressure injection is interrupted for a period from the start of the main injection to the time of cutting the weft.