JPS5922130Y2 - Yarn drop prevention device for weft jet nozzle - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a device for preventing yarn removal from a weft injection nozzle in an air injection loom.

In air injection looms, when weft insertion is completed, the first
As shown in the figure, first, air injection from the weft injection nozzle 2 is stopped, and the gripper 1 grips the weft Y.

Next, the weft threads inserted between the warp threads are beaten toward the fabric front by a reed (not shown).

As the reed moves forward, the upper and lower warps 3 and 4 also close, and the weft is gripped by the upper and lower warps at a timing before the reed reaches the woven fabric 6.

On the other hand, the other end of the weft thread is held by the gripper 1, so as the reed advances further, the weft thread is stretched, and when the reed reaches the weaving area, the weft thread between A-B-C is stretched. The tension becomes abnormally large.

The weft yarn in such a state is cut by the cutter 5 after weft beating is completed.

The cut weft yarn Y instantly collapses due to the abnormally high weft tension before cutting, so it shrinks rapidly, and due to its spring action, the tip of the weft Y may be pulled out of the injection nozzle 2, or even if it is not pulled out, its tip may be inside the injection nozzle 2. Situations that interfered with the next injection occurred frequently.

In order to avoid such drawbacks, conventional devices operate the weft injection nozzle at appropriate timings other than the weft insertion to inject auxiliary airflow with a low pressure that does not cause the yarn to come off. There is a method to prevent the weft thread from coming off from the jet nozzle.

As an example of implementing this method, as shown in FIG.
1, in addition to the convex part 111 (section PI) for performing normal weft insertion, a convex part 112 (section P2) which is one step lower than the convex part 111 for supplying auxiliary airflow may be formed.

8 is a known regulator for changing the injection pressure of the injection nozzle.

However, the method of providing the convex portion 112 on the Koni/Troll cam 11 is such that (1) when the type and thickness of the inserted weft changes, (2) when the weaving width, rotation speed, etc. I have to change the injection pressure of the nozzle,
If this injection pressure is changed, the injection pressure of the auxiliary airflow will also change, making it impossible to achieve the purpose of preventing weft slippage.

This is because the pressure of this auxiliary airflow is set to be as low as possible in order to save air and prevent the spun yarn from being cut (blown out) due to untwisting.

Therefore, each time the injection nozzle pressure is changed, it is necessary to replace a suitable cam with a different height of the convex part 112, which is not only complicated, but also requires a lot of work to find a cam with a suitable convex part 112. This causes a decrease in efficiency.

The purpose of this invention is to eliminate such drawbacks, and the gist of the invention is to provide a system in parallel with the main jetting circuit for weft insertion, which is weak when the cutter cuts the yarn connected to the edge of the fabric after weft insertion is completed. A second circuit is provided for injecting an auxiliary airflow of pressure, and each circuit has a regulator for setting the pressure of the injected airflow to a predetermined value independently and independently of the rotation speed of the loom, etc. This is what was installed.

This invention will be explained in more detail below with reference to embodiments shown in the accompanying drawings.

Components having similar structural functions to those in FIG. 2 are designated by the same reference numerals.

In FIG. 3, the weft jet nozzle 2 is connected to the regulator 8.
and a mechanical valve 7 for supplying the weft air flow.

The regulator 8 is used to set the injection pressure of the injection nozzle 2.

The mechanical valve 7 opens and the injection nozzle 2 communicates with the air tank 9 only when its arm 10 is pushed by a convex portion 111 of a cam 11 rotating in synchronization with the driving shaft of the loom.

The conduit 18 is for supplying auxiliary airflow, and has one end connected to the air tank 9 and the other end communicated with the conduit 17 at an appropriate position between the injection nozzle 2 and the mechanical valve 7.

The conduit 18 includes a regulator 12 for adjusting the pressure of the auxiliary airflow, a mechanical valve 13 for opening and closing the flow path of the conduit 18, and a check valve 16 for preventing backflow from the conduit 17.
Contains.

The mechanical valve 13 is installed by a control cam 15 so as to open only at appropriate times other than during weft insertion.

With this structure, the mechanical valve is opened during the weft insertion period, and airflow is supplied to the nozzle 2 through the conduit 17.

At this time, due to the presence of the check valve 16, air from the conduit 17 will not flow back through the conduit 18.

When it is time for the cutter to cut the weft yarn after weft insertion is completed, the mechanical valve 13 opens and an auxiliary airflow with a low pressure that does not cause the yarn to come off is supplied to the nozzle 2 through the conduit 18.

Therefore, it is possible to prevent the thread from coming off due to the spring action of the weft thread.

In this device, the type, roundness, etc. of the inserted weft, weaving width, rotation speed, etc. (weft insertion conditions) change, and even if the injection pressure of the weft injection nozzle is changed to correspond to this, the pressure of the auxiliary air flow will change. Even if the pressure of the auxiliary airflow is set to be suitable for the above-mentioned weft insertion conditions, it is possible to set the pressure to the required pressure independently and easily by simply adjusting the regulator 12, regardless of the injection pressure of the weft injection nozzle. I can do it.

As a result, it has the effect of significantly improving work efficiency.

Furthermore, although a case has been shown in which the conduit 17 for supplying weft airflow and the conduit 18 for supplying auxiliary airflow are connected to the same air tank 9, the side conduits may be connected to separate air tanks.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing the weft insertion state of the fluid jet loom;
The figure is an explanatory diagram showing that auxiliary airflow is provided by a cam,
FIG. 3 is an explanatory diagram showing an apparatus for implementing this invention. 1... Gripper, 2... Weft injection nozzle, 5...
Cutter, 7, 13... Mechanical valve, 8, 12...
... Regulator, 16... Check valve, 17... Conduit for supplying weft airflow, 18... Conduit for supplying auxiliary airflow.

Claims (2)

[Scope of utility model registration request] (1) In an air injection loom, a valve mechanism for setting the injection period for weft insertion and a regulator for setting the pressure for weft insertion are arranged in series between the weft injection nozzle and the air tank. a check valve that is parallel to the main circuit to prevent backflow from the main circuit, and a second valve mechanism that opens the circuit only before and after cutting the weft and sets the period. A device for preventing thread removal from a weft jet nozzle, which is provided with a sub-circuit in which a second regulator for setting the air flow pressure is arranged in series. (2) Utility model registration claim No. 1 (
A device for preventing thread removal from the weft jet nozzle described in item 1).