JPS5831506B2 - Manufacturing method of spool in fluid control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a spool in a fluid control valve that controls fluid flow.

In a fluid control valve that discharges the fluid supplied to the valve body to the low pressure side when it is not in neutral, there is an axial hole that serves as a discharge passage for the fluid applied to the land of the spool that is slidably inserted into the valve body. It is installed through the.

Conventionally, this type of spool has been disclosed in Utility Model Application Publication No. 14992 of 1930.

The spool material is divided to make it easy to provide an axial hole in the land portion, and the divided spool materials are screwed together and manufactured integrally.

However, the joints tend to separate due to vibrations and shocks during the operation of the spool, and it is necessary to provide accurate centering between the spool materials, making it difficult to manufacture easily as machining for centering is troublesome. There were drawbacks such as not being able to do so.

The present invention aims to eliminate such drawbacks, and has as its technical object to easily manufacture a spool having a strong bond by melting and bonding spool materials.

Therefore, in the present invention, a plurality of axial holes are opened in one end surface of the cylindrical material and are arranged around the axis of the cylindrical material, and
One spool material is formed in which the bottoms of the plurality of axial holes are open and communicated with the outer peripheral surface of the cylindrical material, and one end surface of one spool material where the axial holes are open is butted against one end surface of another spool material. The technical means is to form an annular groove from the outer peripheral surface of the joined spool material by friction welding and provide a land portion through which multiple axial holes penetrate, and the bottom of the axial hole is connected to the outer peripheral surface of the cylindrical material. Since the axial hole is not in a sealed state during friction welding between the spool materials when the opening is communicated with the spool material, it is possible to easily manufacture a spool that is joined by melting and closing the opening of the axial hole and having a strong joint state. can.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 shows a fluid directional control valve using a spool according to the present invention, in which 1 is a valve body with annular grooves P, A, B inside.
, R, , R2 is bored, and a spool 3 is slidably inserted into the slide hole.

The neutral position of the spool 3 is set by springs 4A and 4B, and the rightward and leftward positions are controlled by an electromagnetic device 6A via pins 5A and 5B.
, 6B, respectively.

The spool 3 has 5@ land portions 7, 8A as shown in FIGS. 2 and 3.

9A, 9B and four annular grooves 10A between each land portion.
, IOB, IIA, and IIB, and land portions 8A and 8B.
There are annular grooves 10A and 11A and annular grooves 10B and 11.
A plurality of axial holes 12A, 1 that communicate with each other and serve as fluid passages.
2B, and a bottle 5A is provided at both ends of the spool.
, 5B.

4 and 5 show the spool 3 before formation, 3A.

3B is a spool material, and one end surface 14A of the cylindrical material.

14B, a plurality of axial holes 12A, 12B are arranged around the axis of the cylindrical material, and annular notches 15A, 15B are formed from the outer peripheral surface to communicate the bottoms of the axial holes with the outer peripheral surface. Form (・ru.

And the axial holes 12A of the spool materials 3A and 3B.

One end surface 14A, 14B where 12B is open is butted against each other, and the spool material is rotated relative to each other while applying an axial load to the spool material, and the end of each spool material is melted and joined by the frictional heat generated on the abutted end surface.The shaft is assembled by friction welding. After melting and closing the openings of the direction holes 12A and 12B as shown in FIG. 6 to firmly join the spool materials 3A and 3B,
As shown in FIG. 2, annular grooves 10A, IOB, 11A, and 11B are formed by machining from the outer peripheral surfaces of the spool materials 3A and 3B, communicating with both ends of the axial holes 12A and 12B. (Axial holes 12A, 12B between land portions 7 and 9A and between land portions 7 and 9B)
A land portion 8A that penetrates through the land portion 8A.

8B is provided.

Axial hole 12A when machining spool materials 3A and 3B
, 12B, etc., can be easily removed to the outside by blowing compressed air from the opening side of one end surface 14A, 14B and blowing it away from the annular notches 15A, 15B before friction welding. Furthermore, since the axial holes 12A and 12B are not sealed during friction welding, cracks caused by high pressure in the axial holes are prevented, and defects in the spool material are reduced.

The operation of the fluid direction control valve is such that when the spool 3 is in the neutral position shown in FIG.
, axial holes 12A, 12B, annular grooves 11A, 11B, flow to grooves R1, R2, and are discharged to the low pressure side, and grooves A, B are closed by land portions 8A, 8B.

When the spool 3 is moved to the right by the drive of the electromagnetic device 6A,
Fluid from groove P passes through annular groove 10A, axial hole 12A, and annular groove 11A to groove A, and fluid from groove B flows through annular groove 10.
B, axial hole 12B, and annular groove 11B to flow into groove R2, respectively.

Similarly, when the spool 3 is moved to the left by driving the electromagnetic device 6B, the fluid from the groove P flows to the groove B, and the fluid from the groove A flows to the groove R1.

Since the axial holes 12A and 12B are provided with a relatively large diameter, a large passage area for the fluid is obtained, and pressure loss of the control fluid due to the spool 3 can be reduced.

As described above, according to the present invention, the bottom of the axial hole opened in one end surface of the cylindrical material forming the spool material is opened and communicated with the outer peripheral surface of the cylindrical material, and the axial hole is sealed during friction welding between the spool materials. To avoid this, it is possible to create an axial hole in the spool material with only one end open to the outside, but compared to that, it prevents cracks in the spool material and reduces the occurrence of defective products. Moreover, since cracks are prevented, multiple axial holes can be easily formed around the axis of the spool material, and the small spool has an optimal passage area according to the control flow rate of the fluid control valve. It has unique effects such as the ability to obtain

[Brief explanation of the drawing]

The figure shows one embodiment of the present invention, and FIG. 1 is a partially sectional front view of a fluid control valve using a spool according to the present invention;
Figure 2 is an enlarged vertical cross-sectional view of the spool, and Figure 3 is the
Figure 4 is an enlarged longitudinal cross-sectional view of the spool material before friction welding, Figure 5 is a cross-sectional view taken along line ■-v in Figure 4, Figure 6 is the spool after friction welding. An enlarged longitudinal cross-sectional view of the material. 3...Spool, 3A, 3B...Spool material, 7.8A, 9A, 9B...Land portion, 10A. 10B, IIA, IIB... annular groove, 12A. 12B...Axial hole.

Claims (1)

[Claims] 1 A single spool in which a plurality of axial holes are opened at one end surface of a cylindrical material and are arranged around the axis of the cylindrical material, and the bottoms of the plurality of axial holes are opened and communicated with the outer peripheral surface of the cylindrical material. The materials are formed, and one end surface of one spool material where the axial hole opens is butted against one end surface of another spool material and joined by friction welding, and an annular groove is formed from the outer peripheral surface of the joined spool material. A method for manufacturing a spool in a fluid control valve, which is provided with a land portion through which a plurality of axial holes pass.