JPH07167063A - Check valve for injection pump for fluid injection weaving machine - Google Patents

Abstract

PURPOSE:To provide a device which is constituted to minimize the occurrence of a reverse flow owing to an answer delay during opening and closing, reduce the occurrence of wear, and reduce the increase of a reverse flow amount when wear occurs. CONSTITUTION:By using a valve body 2 in the shape of a short cylinder the tip 21 of which is formed in a semispherical shape or the shape of a warhead, a valve body 2 is floatably fitted in the guide hole 11 of a case 1. The tip 21 of the valve body is positioned facing a trumpet-form valve seat 31 and a stopper 4 to regulate the stroke of the valve body 2. A fluid passage running from the valve seat 31 side of the case 1 to the back side thereof consists of a hole 22 with a bottom formed from the back of the valve body 2 and a radial hole 23 through which the hole with a bottom and the outer periphery on the tip side of the valve body 2 are interconnected. In a check valve, when a water impact in a reverse flow direction is exerted, a water impact pressure is collided with the bottom of the hole 22 with a bottom and the valve body 22 is accelerated in a closing direction, whereby the speed of the response of the valve body 2 during closing of a valve is extremely increased and the occurrence of a reverse flow is sharply reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a check valve used in an injection pump for supplying a weft insertion fluid to a weft insertion nozzle of a fluid injection loom.

[0002]

2. Description of the Related Art As an injection pump of a fluid injection loom, a piston pump is used as shown in FIG. The pump 6 has a piston 61 that reciprocates in synchronization with the rotation of the crank shaft of the loom, and has check valves 5a and 5b at the suction port 62 and the discharge port 63 of the pump 6, respectively.
When the piston 61 retracts, the check valve 5a on the suction side opens and the fluid flows into the cylinder 64 of the pump. When the piston 61 moves forward, the check valve 5a on the suction side closes and the check valve 5a on the discharge side reverses. The stop valve 5b opens, and the fluid pushed out from the cylinder 64 is supplied to the weft inserting nozzle 7. Since the rotational speed of the fluid injection loom is a high-speed rotation exceeding 1000 rpm, small and highly responsive valves are required as the check valves 5a and 5b.

Therefore, conventionally, a check valve having a spherical valve body has been used as a check valve of an injection pump of a fluid injection loom. FIG. 3 shows an example thereof, in which a case 52 is provided with a recess 52 for accommodating a spherical valve body 51, and several through holes 53, 54 connected to the recess 52 are provided. Has been. The bottom of the recess 52 is hemispherical, and the valve body 5
1 can move freely in the recess 52. On the side of the case 1 where the recess 52 is provided, the case lid 3 provided with a trumpet-shaped valve seat 31 that opens toward the valve body 51 is fixed. The flow path 32 connected to the center of the valve seat 31 is formed by the case lid 3
Penetrates through. Usually, the case 1 and the valve body 51 are made of metal, and the case lid 3 is made of synthetic resin.

The check valve having the above structure is attached to the suction port and the discharge port of the injection pump 6 with the case lid 3 on the inflow side.

When the fluid flows from the case lid 3 side, the valve body 51 is pushed toward the bottom side of the recess 52 by the fluid pressure,
A gap is opened between the valve body 51 and the valve seat 31, and the fluid flows from the case lid 3 side to the case 1 side through the gap. On the other hand, when fluid pressure is applied from the case 1 side, the valve body 51
Is pressed against the valve seat 31 to prevent the fluid from flowing from the case 1 side to the case lid 3 side.

[0006]

Although the check valve having such a conventional structure has an advantage that the structure is simple, the check valve has a large reverse flow rate when the valve is closed, especially when the valve body 51 is worn. There was a drawback that the flow rate was very high. That is, since the rotation speed of the fluid jet loom is very high, the check valve 5
Also repeats the opening / closing operation at high speed, but when fluid pressure is applied in the opposite direction, the time delay required for the valve element 51 to move and close the valve becomes relatively longer than the opening / closing cycle of the valve, Even when the valve is new, nearly 30% of the pump discharge amount flows back.

Further, since the valve body 51 can freely rotate in the recess 52, the valve body 51 rotates in the recess 52 due to the non-parallel flow around the valve body 51, and the valve body 51 is worn. The valve body 51 was distorted due to wear, and the reverse flow rate could reach 50% of the pump discharge rate.

According to the present invention, the response of the valve element at the time of opening and closing is quick, and therefore the reverse flow rate due to the operation delay of the valve element can be minimized, and the wear is small, and the reverse flow rate when worn is also increased. An object of the present invention is to obtain a check valve for a jet nozzle of a fluid jet loom that can be reduced.

[0009]

The check valve according to the present invention uses a short cylindrical valve body 2 having a hemispherical or warhead-shaped tip 21 (side abutting the valve seat 31) as a valve body. Disc 2
Is movably fitted in a guide hole 11 provided in the case 1. A case lid 3 provided with a trumpet-shaped valve seat 31 facing the tip 21 of the valve body is fixed to the case 1, and a stopper 4 for restricting a movement stroke of the valve body 2 is provided on the side opposite to the case lid of the case 1. Is provided.

Further, in the check valve of the present invention, the through hole 24 connecting from the valve seat 31 side of the case 1 to the opposite side is provided so as to connect the rear end of the valve body 2 and the outer circumference of the front end side.
That is, the fluid passage that flows from the valve seat 31 side of the case 1 to the rear side thereof has a bottomed hole 22 formed from the back of the valve body 2.
And a radial hole 23 connecting the bottomed hole and the outer periphery of the valve body 2 on the tip side.

[0011]

In the check valve having the structure of the present invention, when the fluid flows from the case lid 3 side, the fluid pressure causes the valve body 2 to move to the rear side, so that the valve seat 31 and the tip 21 of the valve body are separated from each other. There is a gap between them. The fluid passes through this gap, further passes through the radial hole 23 and the bottomed hole 22 provided in the valve body 2, and flows to the back of the valve body 2. On the other hand, when a fluid pressure is applied from the back side of the valve body 2, the fluid pressure causes the valve body 2 to move forward, and the tip end 21 thereof abuts the valve seat 31 to prevent the fluid from flowing backward.

As described above, since the loom rotates at a very high speed, the injection of the fluid for weft insertion is started and stopped abruptly, and at the time of the start and stop, the fluid pressure is momentarily increased by the water hammer action. Occurs. With the check valve of the conventional structure, the instantaneous pressure due to the water hammer action easily passed through the check valve, and this instantaneous pressure increase could not be effectively used for the opening / closing operation of the check valve. . On the other hand, in the check valve of the present invention, when a water hammer in the reverse direction acts,
The water hammer pressure collides with the bottom of the bottomed hole 22 provided in the valve body 2 (the tip side of the valve body), and the force accelerates the valve body 2 in the closing direction. The time delay of is extremely small, and the reverse flow rate when the opening / closing cycle of the valve is fast can be greatly reduced.

Further, in the check valve of the present invention, the movement of the valve element 2 is limited to the axial movement within the guide hole 11 and the free rotation around the axis thereof, so that the valve element 2 moves irregularly. Uneven wear, and the wear of the valve body 2 at the contact portion with the valve seat 31 is also uniform, so there is little wear even during long-term use, and the reverse flow rate when worn The increase can be small.

[0014]

1 is a sectional view showing an embodiment of a check valve according to the present invention. The case 1 has a short cylindrical shape with a diameter of 20 mm, and a guide hole 11 is provided in the center thereof, and a short cylindrical valve element 2 having a tip (case lid 3 side) 21 as a warhead is loosely fitted in the guide hole. It is equipped. A fitting step portion (inlay) 12 is provided on the case lid 3 side of the case 1, and the case lid 3
Is fixed in a state of being fitted and positioned in the fitting step portion. The case lid 3 is provided with a trumpet-shaped valve seat 31 facing the tip 21 of the valve body, and a flow path 32 passing through the axis of the valve seat 31 penetrates the case lid 3.

A stopper plate 4 is fixed to the case 1 on the side opposite to the case lid. The surface of the stopper plate 4 on the case 1 side is provided with a recess 41 that allows the rear end of the valve body 2 to enter, and the stroke of the valve body 2 is restricted by the depth of the recess 41. . A through hole 42 is provided in the axial center of the stopper plate 4, and a hole (bottomed hole) 22 with a bottom having the same diameter as that of the through hole 42 is formed.
Is drilled from the rear side in the center of the valve body 2. A plurality of radial holes 23, which connect the bottom side of the bottomed hole 22 and the outer circumference of the tip of the valve body, are provided with the central axis of the valve body 2 as the axis of symmetry.

The case 5 is attached to the valve 5 constructed as described above.
When the fluid flows in from the side, the fluid pressure pushes the valve body 2 toward the stopper plate 4 side, and the fluid forms a gap formed between the valve seat 31 and the tip 21 of the valve body and the radial hole 23. It flows through a through hole 24 formed with the bottomed hole 22.

On the other hand, when a momentary pressure rise acts on the stopper plate 4 side, this pressure is applied to the through hole 42 of the stopper plate.
And the water hammer force is applied to the bottom surface of the bottomed hole 22 through the bottomed hole 22 provided in the valve body. Therefore, the valve body 2 has the valve seat 31.
The valve 5 is closed by rapidly accelerating to the side and moving forward.

[0018]

As described above, the check valve for the injection pump of the fluid injection loom of the present invention utilizes the instantaneous pressure increase that occurs when the injection of the weft insertion jet flow at high speed in the fluid injection loom is stopped. Since the valve is closed rapidly, the reverse flow due to the delay in the operation of the valve body when the valve is closed can be minimized. Also, there is little wear due to use,
Moreover, since the increase in the reverse flow rate when worn is small, the life can be extended.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment.

FIG. 2 is a schematic diagram showing a use position of a check valve in an injection pump.

FIG. 3 is a sectional view showing an example of a conventional check valve.

[Explanation of symbols]

 2 Valve body 11 Guide hole 21 Tip 23 Radial hole 24 Through hole 31 Valve seat

Claims (1)

[Claims] 1. A tip (21) facing a trumpet-shaped valve seat (31).
A semi-cylindrical or warhead-shaped short cylindrical valve body (2) is fitted in a guide hole (11) provided in the case (1) so that it can move back and forth in the axial direction, and the valve body (2) moves. A stopper (4) that restricts the stroke is provided, and a fluid through hole (24) that connects from the valve seat (31) side to the opposite side is a bottomed hole that is drilled from the back of the valve body (2).
A check valve for an injection pump of a fluid injection loom, comprising: (22) and a radial hole (23) extending from the bottomed hole to the outer circumference of the tip end side of the valve body (2).