JPH04337169A - Spool type switching valve and manufacture of internal pipe used for spool type switching valve - Google Patents

Abstract

PURPOSE:To realize smooth slide of a spool without requiring work to high- precisely finish the peripheral surface of a spool hole by mounting a pipe, in the peripheral surface of which through-holes corresponding to a plurality of ports are formed, on the inner periphery of the spool hole. CONSTITUTION:In a spool type switching valve, a plurality of ports 4 are opened to a straight spool hole 2, formed in a body 1, and at intervals in the axial direction. A spool 8 fitted inside of the spool hole 2 is moved in the axial direction to switch the connection states of the ports 4. In this case, a spool 6 in the peripheral surface of which through-holes 7 corresponding to the respective ports are formed is engaged with the inner periphery of the spool hole 2. In manufacture of the pipe 6, lateral mold holes 13 are formed in positions, where the through-holes 7 of the pipe 6 are formed, in an engaging hole 12 of a mold 11. After a pipe material is engaged with the mold, the mold is placed in water, explosives 18 placed in separate positions are exploded, and through underwater propagation of an impact wave, holes are blown in the pipe from the inner peripheral side to form the through-holes 7.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention has a plurality of ports opened at intervals in the axial direction in a straight spool hole formed in a body, and a spool fitted in the spool hole is moved in the axial direction. The present invention relates to an improvement of a spool-type switching valve in which the connection state of each port is switched by using a spool-type switching valve, and a method of manufacturing an internal pipe used in the improved spool-type switching valve.

0002

[Prior art and problems to be solved by the invention] Conventionally,
The body of this type of spool-type switching valve, in which the spool hole and port are formed, is generally made of cast metal, and in order for the spool to slide smoothly within the spool hole, the inner peripheral surface of the spool hole must be raised. It is necessary to finish it with precision. Therefore, it takes time and effort to manufacture, leading to high costs.

0003

[Means for Solving the Problems] A spool-type switching valve according to the first aspect of the present invention has been completed in order to solve the above-mentioned problems. It has a structure in which a pipe with a through hole on its circumference is fitted.

[0004] A second invention also provides a method suitable for manufacturing the interior pipe used in the first invention, in which the pipe material is placed at a predetermined position on the inner peripheral surface of the fitting hole. The fitting hole is inserted into the fitting hole of the mold, which has a hole that is perpendicular to the axial direction of the fitting hole, and an explosive is installed at a position away from the pipe material, and the explosive and the mold are submerged. The explosive is detonated and the resulting shock wave is propagated underwater to act on the inner circumferential surface of the pipe material, and a hole is punched out from the inner circumferential side of the pipe material at a portion corresponding to the hole in the mold. The structure was designed to form.

[0005]

[Operations and Effects of the Invention] According to the spool type switching valve of the first invention, the spool slides inside the pipe fitted in the spool hole, so that the spool can be slid smoothly. . In other words, when manufacturing the body, the inner periphery of the spool hole can be simply processed, and then a pre-prepared pipe can be fitted into the body, eliminating the need for high-precision finishing of the spool hole, which was previously essential. Manufacturing is simplified and manufacturing costs can be reduced.

Furthermore, according to the pipe manufacturing method of the second invention, when the explosive is detonated, the shock waves generated thereby propagate through water and enter the inner circumferential side of the pipe material, causing damage to the inner circumferential surface of the pipe material. A large impact force is applied to the mold, and the part of the mold corresponding to the mold hole where the outer peripheral surface is not covered is punched out from the inside, thereby forming a through hole in the peripheral surface.

[0007] In the pipe manufactured by this method, since the peripheral surface of the pipe is punched from the inside, burrs are not formed on the inner peripheral surface on which the spool slides, and there is no need to perform post-processing on the inner surface.

In addition, as a conventional method similar to the method of the present invention, a mold is placed on the outside of the pipe material in the same way,
A known method is to insert an explosive directly into the hollow of a pipe material and use the explosive energy to punch out a hole.
The method of the present invention has a number of advantages over the above-mentioned conventional method because the explosive is placed at a position separated from the pipe material and the impact force is applied through underwater propagation. In other words, in the conventional method, when punching a large number of pipe materials at the same time, it is necessary to insert explosives into each pipe material, resulting in poor work efficiency. By arranging a plurality of pipe materials side by side with respect to a common explosive, it is possible to easily punch out a large number of pipe materials at the same time. Also, unlike when explosives are placed inside the pipe material, there are no restrictions on the inner diameter of the pipe to be processed. Furthermore, if the explosive power of the explosive is too strong, there is a risk of damaging the pipe material itself or the mold, which is difficult to control with conventional methods, but with the method of the present invention, the distance between the explosive and the pipe material By adjusting appropriately, the optimum impact force can be easily obtained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

First, a spool type switching valve according to the present invention will be explained with reference to FIGS. 1 and 2. Reference numeral 1 denotes a body made of cast metal, in which a straight spool hole 2 is formed, and a plurality of circumferential grooves 3 are bored at intervals in the axial direction on the inner circumferential surface of the body. At the same time, ports 4 communicating with each of the circumferential grooves 3 are opened on one side of the outer surface.

In the spool hole 2 of the body 1, as shown in FIG. 2, there is a metal pipe having a plurality of pairs of through holes 7 formed through its circumferential surface corresponding to each of the circumferential grooves 3 described above. 6 is fitted. A spool 8 is fitted into the pipe 6 so as to be freely slidable in the axial direction, and is reciprocated by the magnetic force of a solenoid (not shown) and the elasticity of a return spring 9.

When the spool 8 reciprocates, the connection state of each port 4 is switched through the through hole 7 of the pipe 6 and the circumferential groove 3 that matches it, but the spool 8 has a smooth surface. Since it slides inside the metal pipe 6 with low frictional resistance, smooth sliding is ensured.

As described above, by adopting the structure in which the metal pipe 6 is fitted into the spool hole 2, processing of the inner periphery of the spool hole 2, which conventionally required high-precision finishing, is now possible.
It requires simple processing and is easy to manufacture.

Next, an embodiment of the method for manufacturing the pipe 6 described above will be described with reference to FIGS. 3 to 5.

Reference numeral 11 denotes a mold, in which a vertical fitting hole 12 into which the pipe material 6a is fitted is formed, and the above-mentioned pipe is formed on the inner peripheral surface of the fitting hole 12. A horizontal mold hole 13 is formed corresponding to the position where the through hole 7 of No. 6 is formed. This mold 11 is mounted on a support stand 14, and a cover plate 16 is attached to the outer surface of the mold hole 13.

An explosive 18 connected to a detonator (not shown) is installed at a certain distance from the pipe material 6a directly above the mold 11, and the explosive 18 and the pipe material 6a are connected to a detonator (not shown).
The mold 11 fitted with the metal mold 11 is immersed in water stored in a water tank. Water does not enter the mold hole 13 of the mold 11 described above because its outer surface is covered with the cover plate 16.

When the explosive 18 is detonated, the resulting shock wave propagates through the water and enters the inner circumferential side of the pipe material 6a, causing a large impact force to act on the inner circumferential surface of the pipe material 6a. A portion of the outer peripheral surface corresponding to the mold hole 13 that is not covered is punched out from the inside, thereby forming a through hole 7 in the peripheral surface.

At this time, the punched cross section of the through hole 7 has a rounded inner edge as shown in FIG.
There is no formation of burrs that hinder the sliding of the spool 5, and no post-processing of the inner surface is required.

In this embodiment, the explosive 18 is installed at a position apart from the pipe material 6a, and the impact force is applied by underwater propagation. Therefore, for example, the explosive can be inserted directly into the pipe material 6a. Compared to the case of punching by punching, there is no restriction on the inner diameter of the pipe 6 to be processed. Further, by changing the distance between the explosive 18 and the pipe material 6a, the magnitude of the impact force acting on the inner peripheral surface of the pipe material 6a can be easily adjusted. Furthermore, by installing one elongated explosive and arranging a plurality of pipe materials 6a in a mold 11 below it, it is possible to punch out a large number of pipe materials 6a at the same time. .

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the first invention.

FIG. 2 is a partially cutaway perspective view of a pipe that fits inside.

FIG. 3 is a plan view of a manufacturing apparatus according to a second invention.

FIG. 4 is a sectional view thereof.

FIG. 5 is a partially enlarged sectional view showing a punched cross section of a pipe hole.

[Explanation of symbols]

Claims (2)

[Claims] Claim 1: A plurality of ports are opened at intervals in the axial direction in a straight spool hole formed in a body, and a spool fitted in the spool hole is moved in the axial direction to open each port. A spool type switching valve configured to switch a connection state, characterized in that a pipe having a transparent through hole corresponding to each of the ports is fitted on the inner periphery of the spool hole. . 2. A plurality of ports are opened at intervals in the axial direction in a straight spool hole formed in the body, and a spool fitted in the spool hole is moved in the axial direction to open each port. A method for manufacturing a pipe having through holes corresponding to the ports, which are fitted into the spool holes of a spool-type switching valve for switching the connection state, the pipe having through-holes corresponding to the ports, the pipe being made of a pipe material. The mold is fitted into the fitting hole of a mold having a hole perpendicular to the axial direction of the fitting hole at a predetermined position on the inner peripheral surface of the fitting hole, and at a position spaced apart from the pipe material. An explosive is installed, the explosive and the mold are placed in water, the explosive is detonated, the resulting shock wave is propagated underwater, and acts on the inner circumferential surface of the pipe material. A method for manufacturing an interior pipe for use in a spool-type switching valve, characterized in that the through hole is formed by punching out a portion of a mold from the inner peripheral side that corresponds to the mold hole.