JP2007092944A - Solenoid controlled pilot operated valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable us to easily perform maintenance working such as replacement of a spool by detaching and attaching an end block because the end block which is located on both ends of a spool of a valve body of a solenoid controlled pilot operated valve is made small and simplified and moreover, magnitude of the solenoid controlled pilot operated valve is made compact as it keeps fitted with the solenoid controlled valve. <P>SOLUTION: The solenoid controlled pilot operated valve provides a pair of end covers which is attached to the end face of a valve body and includes pilot oil chambers facing both ends in axial direction of the spool, respectively and a solenoid controlled valve block which is fitted to respective sides of the end covers and fitted with the solenoid controlled valve. It also forms an oil passage which connects the solenoid controlled valve and the pilot oil chambers to the solenoid controlled valve block and the end covers. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to an electromagnetic pilot switching valve that is switched by a pilot oil of an electromagnetic valve.

A known electromagnetic pilot switching valve that is switched by a solenoid valve has a pair of ends having a valve body slidably fitted with a spool for switching an oil passage and pilot oil chambers facing both axial end portions of the spool. A block and a solenoid valve that is attached to each of the pair of end blocks and that feeds and discharges pilot pressure oil corresponding to an electrical signal to the pilot oil chamber is provided. The spool is slid by the pilot pressure oil (see, for example, Patent Document 1).

As another form of the electromagnetic pilot switching valve, an electromagnetic valve is integrated in one end block and pilot pressure oil is connected to the other end block by a hydraulic hose (for example, see Patent Document 1).

The electromagnetic pilot switching valve is installed according to the number of hydraulic actuators operated by supplying and discharging hydraulic oil. In the case where a large number of electromagnetic pilot switching valves are installed, an appropriate number, for example, five is combined into one valve body to form a multiple valve.
JP 2001-289202 A (FIGS. 2 and 4)

The conventional electromagnetic pilot switching valve in the form as described above has the following problems to be solved.

(1) Large end block:
A pair of end blocks to which the solenoid valve is attached include a plurality of oil passages for the solenoid valve mounting portion and the pilot primary pressure to the solenoid valve, the pilot secondary pressure to the pilot oil chamber, and drain oil. ing. Therefore, the end block becomes large, and requires a lot of machining to form an oil passage and is expensive.

(2) Large installation space:
Since large end blocks are attached to both ends of the valve body, the electromagnetic pilot switching valve is long and large in the axial direction of the spool as a whole. Further, the hose pipe occupies a large space in the case where the solenoid valve is combined in one end block and the pilot oil is connected to the other end block by a hydraulic hose. Therefore, a large installation space is required when installing on a work machine or the like, and the installation may be restricted due to the frame structure of the work machine or the like. In addition, the end block itself needs to have a special shape so as not to interfere with surrounding structures.

(3) Maintenance is difficult:
When exchanging the spool fitted to the valve body or performing maintenance work with the spool removed, it is necessary to attach and detach a large and heavy end block, which makes the maintenance work difficult.

The present invention has been made in view of the above facts, and its technical problem is that the end blocks located at both ends of the spool of the valve body of the electromagnetic pilot switching valve are made small and simple, and the solenoid valve is attached. The size of the electromagnetic pilot switching valve is made compact, and maintenance work can be easily performed by attaching / detaching the end block such as replacement of the spool.

According to the present invention, as an electromagnetic pilot switching valve that solves the above technical problem, a valve body having a spool that is slidably fitted, and a pilot that is attached to an end surface of the valve body and faces both axial end portions of the spool. An oil passage comprising a pair of end covers having oil chambers and a solenoid valve block attached to each side of the end covers and having solenoid valves attached thereto, and connecting the solenoid valve and the pilot oil chamber to the solenoid valve block and the end cover An electromagnetic pilot switching valve is provided.

Preferably, the end cover includes a base portion in which an oil groove forming the oil passage is carved in a flat portion, and a cover portion attached to the flat portion via a seal member. Furthermore, the cover part is divided | segmented into the plate attached to this plane part, and the cover attached to this plate. The valve body includes a plurality of spools substantially parallel to each other, at least the bases of the end covers corresponding to the plurality of spools are integrally formed, and the respective electromagnetic valve blocks are integrally formed.

An electromagnetic pilot switching valve configured according to the present invention includes a pair of end covers having a pilot oil chamber on an end face of a valve body, and an electromagnetic valve block having an electromagnetic valve attached to a side thereof, An oil passage connecting the solenoid valve and the pilot oil chamber is formed in the solenoid valve block. Therefore, the end cover of the valve body is small and simple, and the size of the solenoid pilot switching valve in the spool axial direction with the solenoid valve attached can be reduced, and the end cover is small and simple. Maintenance work such as spool replacement with the end cover attached and detached can be easily performed.

Hereinafter, an electromagnetic pilot switching valve constructed in accordance with the present invention will be described in more detail with reference to the accompanying drawings illustrating preferred embodiments.

A description will be given with reference to FIG. An electromagnetic pilot switching valve denoted by reference numeral 2 has a valve body 6 having a spool 4 that is slidably fitted, and pilot oil chambers 8 that are attached to the end face of the valve body 6 and face both ends of the spool 4 in the axial direction. 9 and a pair of end covers 10, 11 and solenoid valve blocks 12, 12 attached to the side portions of the end covers 10, 11, respectively, to which solenoid valves S1 and S2 are respectively attached. The solenoid valve block 12 and the end covers 10 and 11 are formed with oil passages P connecting the solenoid valves S1 and S2 and the pilot oil chambers 8 and 9, respectively.

One end cover 10 has a large space for the pilot oil chamber 8 to accommodate a spring 14 for holding the spool 4 in a neutral position (the illustrated position) when the electromagnetic pilot switching valve 2 is not operated. ing.

The electromagnetic pilot switching valve 2 is switched as follows. When pilot pressure oil is supplied from one solenoid valve S1 to the pilot oil chamber 8 of one end cover 10, the spool 4 responds to the pressure of the pilot pressure oil against the force of the spring 14 (compressing the spring 14). 1 and the hydraulic oil in the pump oil passage 16 flows into one actuator oil passage 18a. At this time, the pilot oil chamber 9 of the other end cover 11 is connected to the drain via the connected electromagnetic valve block 12. The other actuator oil passage 18b is connected to the tank oil passage.

In order to switch the spool 4 to the other (upper side in FIG. 1), pilot pressure oil is supplied from the electromagnetic valve S2 to the pilot oil chamber 9. In any direction, when the supply of pilot pressure oil is stopped, the spool 4 is returned to the neutral position (the position shown in the figure) by the force of the spring 14.

A description will be given with reference to FIGS. The electromagnetic pilot switching valve 2 in this embodiment is formed as a five-unit valve in which five (4a to 4e) spools 4 are provided on the valve body 6 substantially in parallel.

The end cover 10 includes a base portion 10a in which an oil groove P1 forming an oil passage P is carved in a flat surface portion F, and a cover portion 10c attached to the flat surface portion F via a rubber packing 10b which is a seal member.

The cover portion 10c is further divided into a plate 10e attached to the flat surface portion F and a cover 10f attached to the plate 10e.

The other end cover 11 is substantially the same as the end cover 10 except that the spring 14 is not installed and the cover portion 10d is formed small.

The end covers 10 and 11 corresponding to the five spools 4 are formed by integrating five substantially the same ones. When five are integrated, at least only the base portion 10a may be integrated, and the cover portions 10c and 10d may be separated.

The base portion 10a is formed by forming a flat plate having a required thickness into a shape that matches the contour of the end face of the valve body 6, and forms part of the pilot oil chambers 8 and 9 of each of the five spools 4. A round hole 20 and two bolt holes 22 for attaching two end covers 10 (11) near the round hole 20 to the valve body 6 are provided. A solenoid valve block mounting surface 24 is formed on the side of the flat plate.

The plate 10e and the cover 10f of the cover portion 10c are attached to the valve body 6 by two hexagon socket bolts 34 together with the plate 10e and the cover 10f base portion 10a with an O-ring seal 33 interposed therebetween.

The solenoid valve block 12 to which the five solenoid valves S1 (S2) are attached is formed in a rectangular parallelepiped shape, and includes a drill hole P2 that forms an oil passage P connected to the oil groove P1 of the base portion 10a from each solenoid valve attachment hole 12a. . Since the solenoid valve block 12 is used for mounting only the solenoid valve S1 (S2), it can be formed smaller than the end cover 10 (11). The solenoid valve block 12 is attached to the attachment surface 24 of the base portion 10a via the packing 26.

Description will be made with reference to FIG. 5 together with FIGS. The oil groove P1, which is the oil passage P of the base portion 10a, does not interfere with each other between the solenoid valve block mounting surface 24 and each of the five round hole portions 20, and with the bolt hole 22 and the other round hole portions 20. It is arranged like printed wiring on an electronic board so as not to interfere. The oil groove P1 has a substantially rectangular cross section. The base 10a may be formed by casting as a whole including an oil groove P1 by an appropriate casting such as aluminum die casting.

The cover portion 10c includes a concave portion 28 that accommodates the rubber packing 10b on the surface facing the flat portion F of the base portion 10a.

The operation of the electromagnetic pilot switching valve 2 as described above will be described.

The electromagnetic pilot switching valve 2 includes a pair of end covers 10 and 11 having pilot oil chambers 8 and 9 on the end surface of the valve body 6, and an electromagnetic valve block 12 to which the electromagnetic valve S 1 or S 2 is attached on the side. Oil passages P connecting the solenoid valves S1 and S2 and the pilot oil chambers 8 and 9 are formed in the attachment, end covers 10 and 11 and the solenoid valve block 12, respectively. Therefore, the end covers 10 and 11 of the valve body 6 are small and simple, and the size of the solenoid pilot switching valve 2 in the spool axis direction with the solenoid valves S1 and S2 attached is reduced and the end cover 10 11 have a simple structure, it is possible to easily replace the spool 4 or perform maintenance work with the spool 4 removed. In particular, since the electromagnetic valve block 12 can be reduced in size, space can be secured, parts can be shared, and costs can be reduced.

The oil groove P1 formed in the base portion 10a of the end cover 10 (11) is exposed to the outside, so that a complicated curve can be formed, and interference with the mounting bolt hole 22 is caused like printed wiring on the electronic board. The oil path P1 can be routed according to the electromagnetic valve block 12 which is avoided and minimized. Therefore, the electromagnetic valve block 12 can be installed in a place where there is no interference with other devices and maintenance is easy. Furthermore, since the base 10a is plate-shaped, it can be manufactured by aluminum die casting or casting, and the cost can be reduced.

Furthermore, by dividing the end cover 10 (11) into the plate 10e and the cover 10f, it can be set for each spool 4a to 4e and can be miniaturized.

The present invention has been described in detail based on the embodiments. However, the present invention is not limited to the above-described embodiments, and various modifications or corrections can be made within the scope of the present invention, for example, as described below. Is.

In this embodiment, the sheet-like rubber packing 10b is provided between the flat surface portion F of the base portion 10a and the cover portion 10c. However, as shown in FIG. 5, the packing grooves 30 are formed on both sides along the oil groove P1. However, a string-like rubber packing 32 may be buried here.

In this embodiment, the electromagnetic pilot selector valve 2 is formed as a five-unit valve having five spools 4. However, the electromagnetic pilot selector valve does not have to be a five-unit valve, and may be five or more or less. Needless to say, it is good.

In this embodiment, one end of the pair of end covers 10, 11 of the electromagnetic pilot switching valve 2 is not provided with a spring 14, but the electromagnetic pilot switching valve is spring-loaded on both of the pair of end covers. May be installed.

1 is a cross-sectional view of an electromagnetic pilot switching valve constructed in accordance with the present invention. FIG. 2 is a cross-sectional view showing a reduced size as viewed in the direction of arrows AA in FIG. 1. Sectional drawing seen in the BB arrow direction of FIG. The figure which showed a part of end cover seeing in the CC arrow direction of FIG. FIG. 4 is an enlarged cross-sectional view as viewed in the direction of arrows DD in FIG. 3. Sectional drawing which showed other embodiment of the part shown in FIG.

Explanation of symbols

2: Solenoid pilot switching valve 4: Spool 6: Valve body 8, 9: Pilot oil chamber 10, 11: End cover 10a: Base portion 10c, 10d: Cover portion 12: Solenoid valve block S1, S2: Solenoid valve P: Oil passage P1: Oil groove

Claims (4)

A valve body having a spool that is slidably fitted;
A pair of end covers having pilot oil chambers attached to the end faces of the valve body and facing the respective axial ends of the spool;
A solenoid valve block attached to each side of the end cover and attached with a solenoid valve;
An electromagnetic pilot switching valve characterized in that an oil passage connecting the electromagnetic valve and the pilot oil chamber is formed in the electromagnetic valve block and the end cover. The end cover
A base portion engraved with an oil groove forming the oil passage in a plane portion;
The electromagnetic pilot switching valve according to claim 1, further comprising a cover portion attached to the flat portion via a seal member. The cover is
A plate attached to the flat portion;
Divided into covers that are attached to this plate,
The electromagnetic pilot switching valve according to claim 2. A valve body is provided with a plurality of the spools substantially in parallel;
At least a base portion of each end cover corresponding to a plurality of spools is integrally formed,
Each solenoid valve block is integrally formed,
The electromagnetic pilot switching valve according to claim 2 or 3, wherein

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