JPH04146244A - Method and device for measuring performance of reed for air-jet loom - Google Patents

Abstract

PURPOSE:To accurately and efficiently measure the picking performance of a reed by jetting air flows to plural measurement points at the same cross section-having positions of a picking guide way formed in the reed and detecting the rates of the flows to grasp the guide performance of the air flows. CONSTITUTION:When the picking performance of a reed for an air-jet loom is measured, plural air jet nozzles 5a-5e are bundled in a state capable of being inserted into the center of a weft-guiding way 4 formed among the reeds. The tips of air jets 6a-6e are bent so that the air jets 6a-6e are directed to respective measurement points 4a-4e of the reed having the same cross sections at the points 4a-4e, and simultaneously a flow course-switching device 8 is disposed between the respective nozzles 5a-5e and a compressed air-supplying source 7 so as to enable to successively switch the air jets 6a-6e each other.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to a method and apparatus for measuring the performance of a reed for an air jet loom (air jet loom).
A guideway (hereinafter referred to as ``tunnel'') is created by cutting out the leading edge of the feathers to guide the air jet.

This invention relates to a method and apparatus for measuring the quality of weft insertion performance of reeds that have been formed.

(Prior Art) In an air-jet loom, a large number of sub-nozzles are provided in addition to a main nozzle, and the air jets from these sub-nozzles urge the weft threads in the tunnel to make them fly. The air jet from the sub-nozzle is normally blown diagonally into the tunnel from the front and lower part of the tunnel, collides with the area from the top surface to the back surface of the tunnel, is reflected, and flows along the tunnel to transport the weft yarn. Therefore, by measuring what kind of air flow is generated in the tunnel by the air injected from the sub-nozzle, it is possible to measure the weft insertion performance of the reed for an air-injected loom.

The conventional method of measuring what kind of airflow is generated in the tunnel by the air jet of the sub-nozzle is
actually attach it to the loom, or attach it to the loom 3 and sub nozzle 2.
As shown in Fig. 8, the sub nozzle 2
Air is injected into the tunnel 4 from 1, and the center 6 of the air jet is the tunnel wall (the part from the top to the back)
A pitot tube 9 was placed close to the wall immediately after the point where the tunnel collided with the tunnel 4, and the flow velocity of the air inside the tunnel 4 was measured with this pitot tube.

(Problem to be Solved by the Invention) The wall surface of the tunnel 4 is connected to the upper edge 2 of the notch 2 provided in the reed feather 1.
a, the inner edge 2C, and the lower edge 2e (FIG. 5), and air naturally diffuses from the gaps between the feathers. The guiding performance of the airflow inside the tunnel 4 is as follows:
It can be said that it is determined by the rate at which the air jets colliding with the walls of the tunnel are reflected or diffused on the upper surface 4a, inner surface 4c, and lower surface 4e.

In order to guide the airflow along the tunnel, the edge surface of the notch 2 of each reed feather is inclined in a direction that narrows the airflow a flowing inside the tunnel (Fig. 6), and in some cases, the weft threads of the tunnel are In order to prevent it from flying out forward, the edge surface that becomes the back surface 4C of the tunnel is inclined in a direction that diffuses the air flow a (FIG. 7).

However, in the conventional measurement method, the flow velocity inside the tunnel is measured only at one point, so the top surface of the tunnel,
Even if the balance between reflection and diffusion of airflow changes on the back and bottom surfaces, it cannot be accurately detected, and therefore it has not been possible to accurately measure variations in the weft insertion performance of reeds.

In order to solve this problem, in the above measurements, we either placed many Pitot tubes in the tunnel, or moved one Pitot tube to each position in the tunnel, and measured the flow velocity distribution of the air flow in the tunnel in the measurement cross section. This method is being implemented in some areas. Although this method is considered to be able to measure the weft insertion performance of the reed more accurately than the method of measuring the flow velocity at only one point, it is still possible to measure the weft insertion performance of the reed at two points with approximately the same flow velocity distribution in the tunnel. The reeds sometimes showed completely different weft insertion performance, making it impossible to accurately determine the weft insertion performance of the reeds.

(Means for Solving the Problem) In the present invention, the above problem is solved by individually measuring the air flow guiding performance at a plurality of points 4a to 4e on the wall surface of the tunnel 4 in a certain measurement cross section. In the method of the present invention, the upper surface central portion 4a of the tunnel 4, the inner surface central portion 4C1, the lower surface central portion 4 are
e, air jets 6a to 6e are injected at a constant angle and speed to a plurality of measurement points on the wall surface forming the tunnel 4, such as the earthy corner 4b and the upper back corner 4d, and these air jets 6
Immediately after a to 6e collide with the wall surface of each measurement point 4a to 4e, and at a position as close as possible to the wall surface, each measurement point 4a to 4e is detected using a flow velocity detection sensor such as a pitot tube 9a to 9e. A method is adopted in which the flow velocity in the tunnel 4 in the vicinity is individually detected.

The actual measurement method is to sequentially move one sensor to a plurality of measurement points 4a to 4e, and sequentially deflect the direction of the air jet from the air injection nozzle to each measurement point 4a to 4e. It is possible to measure the flow velocity at each measurement point 4a to 4e using an air injection nozzle and one sensor.

However, this method has the disadvantage that measurement is time-consuming.

Therefore, as a more practical method, a plurality of air injection nozzles 5a to 5e are bundled and the direction of the air jets 6a to 6e is directed to each measurement point 4a to 4e.
This is installed on the upstream side of the tunnel 4, and a plurality of sensors 9a to 9e are prepared so that their tips are located close to the tunnel wall surface at each measurement point 4a to 4e, and these sensors are placed on the measurement cross section of the tunnel. There is a method in which air jets are installed immediately downstream, sequentially inject air jets from a plurality of air injection nozzles 5a to 5e, and the flow velocities of the corresponding sensors 9a to 9e at that time are measured.

(Function) According to the above-mentioned method of the present invention, it is possible to accurately measure the ratio of reflection and diffusion of airflow at each part of the wall surface around the tunnel 4, and the guide performance of the airflow at each part of the wall surface of the tunnel 4. If there is a difference, this is immediately detected as a difference in the measured values. Therefore, two reeds with the same measured values measured by the above method exhibit exactly the same weft insertion performance, and it is possible to accurately measure the sameness of the weft insertion performance. Of course, it is assumed that the two reeds to be compared in this case have the same cross-sectional shape of the tunnel 4, the thickness of the reed feathers I, and the same distance between the reed feathers 1.

The measurement of the pressure by the above method is carried out using a plurality of nozzles 5a to 5e having injection holes directed to each measurement point 4a to 4e on the wall surface of the tunnel 4, and an air supply source 7 to the plurality of nozzles 5a to 5e. By using a measuring device equipped with a switching means 8 that switches sequentially and flow velocity detection sensors 9a to 9e arranged so as to take positions close to each measurement point 4a to 4e, accurate and efficient measurement can be performed.

(Embodiment) Figures 1 to 4 show an embodiment of the present invention, in which 1 is a reed feather, 2 is a notch provided on the front edge of the reed feather, and 3 is a notch provided on the leading edge of the reed feather.
4 is a tunnel formed by a collection of notches 2, 4a is the top surface of the tunnel, 4c is the back surface, 4e is the bottom surface, 4b is the earthy corner of the tunnel, 4d is an earthy corner.

5a to 5e are nozzles with air injection holes at their tips,
Five independent nozzles are bundled so that they can be inserted into the center of the tunnel 4, and air jets 6a to 6e are applied to the top center 4a, bottom center 4e, earthy corner 4b, back center 4c, and earthy corner in the same cross section of the tunnel. The tip is bent so as to face the portion 4d. These nozzles 5a to 5e include
Pressurized air is supplied from an air supply source such as a blower 7, but
A flow path switching device 8 is provided between the supply source 7 and the nozzles 5a to 5e to supply pressurized air only to a selected one of the nozzles 5a to 5e.

9a to 9e are pitot tubes, and the tips of the five pitot tubes are arranged in advance according to the cross-sectional shape of the tunnel 4 at the top center 4a, bottom center 4e, and earthy corner 4b of the peripheral wall of the tunnel 4, respectively.
, are arranged as close as possible to the back center 4c and the earthy corner 4d. The positional relationship of the tips of the pitot tubes 9a to 9e is maintained by a holder 10 that holds the base of each pitot tube 9a to 9e at a position apart from the tunnel 4. Pitot tubes 9a to 9e
is connected to a differential pressure detector 12 via a flow path switch 11, and if the flow path switch 11 on the pitot tube side and the flow path switch 8 on the nozzle side are linked and switched. It's convenient.

During measurement, the flow path switching devices 8 and 11 are switched to supply air to a selected one of the nozzles 5a to 5e, and one of the pitot tubes 9a to 9e corresponding to the nozzle is connected to the differential pressure detector 12. Connecting. Then, the flow path switching devices 8 and 11 are sequentially switched to measure the flow velocity in the tunnel 4 at each measurement point 4a to 4e. The measured flow velocity values reflect the ratio of reflection and diffusion of the airflow on the wall surface at each measurement point in the tunnel, and where the reflectance is high, the airflow velocity is also high.

If a plurality of reeds manufactured to have the same weft insertion performance are measured using the above method, and the measured values of the flow velocity at each measurement point 4a to 4e on the tunnel wall surface are compared,
If the measured values are the same, the reeds will show the same weft insertion performance, and if the flow velocity at the measurement point is different even at one point, the weft insertion performance of the reeds will be different.

Therefore, after actually performing weft insertion with a reed that was designed to have a certain weft insertion performance and confirming its performance, the flow velocity distribution along the wall surface of the reed was measured using the method described above.
By checking the flow velocity distributions of the reeds manufactured afterward using the above measurements, it is possible to easily and accurately determine whether these reeds have the same weft insertion performance.

(Effects of the Invention) As explained above, according to the method of the present invention, it is possible to accurately determine whether or not the desired weft insertion performance has been obtained for each manufactured reed without carrying out a weft insertion test. can be measured. Further, by using the apparatus of the present invention, there is an effect that the method of the present invention can be easily carried out.

[Brief explanation of the drawing]

FIGS. 1 to 4 are diagrams showing an embodiment of the present invention,
1 is a perspective view of a main part showing a measurement state, FIG. 2 is a front view, FIG. 3 is a sectional view of section A in FIG. 2, and FIG. 4 is a sectional view of section B in FIG. 2. Figures 5 to 7 are views showing the cutout part of the reed feather, Figure 5 is a side view, Figure 6 is a sectional view of section C in Figure 5, and Figure 7 is a sectional view of section B in Figure 5. It is a diagram. FIG. 8 is a perspective view showing a conventional method. In the diagram, 3: Osa 4: Tunnel

Claims (2)

[Claims] (1) Air jets (6a
) to (6e) are individually injected, and immediately after these air jets collide with the wall surface of each measurement point (4a) to (4e), the flow velocity in the guide path (4) at a position close to the wall surface is individually measured. A method for measuring the performance of reeds for air injection looms, characterized by measuring the performance of reeds for air injection looms. (2) A plurality of air jet nozzles (5a) to (5e) are bundled and the direction of the air jets (6a) to (6e) is the same on the wall surface of the weft guide path (4) formed in the reed (3). Multiple measurement points (4a) to (4e) at the cross-sectional location
A group of nozzles facing toward the direction of the flow rate, and a plurality of flow velocity detection sensors (9a) to (9e) whose tips are positioned close to the wall surface of the guide path at each of the measurement points (4a) to (4e).
A performance measuring device for air injection looms.