JP2552958Y2 - Pilot pressure operated control valve - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pilot pressure control valve which slides a spool inserted into a valve body with pilot pressure oil to switch the flow of pressure oil.

[0002]

2. Description of the Related Art As a pilot pressure operated control valve, for example, the one shown in FIG. 1 is known. That is, the spool 3 is slidably fitted into the spool hole 2 of the valve body 1, the spool 3 is held at a neutral position by a spring 5 provided in a spring case 4, and
The inside is a pilot pressure receiving chamber 6, and pilot pressure oil is supplied into the pilot pressure receiving chamber 6 to move the spool 3 against the spring 5 to set a pressure oil supply position. In such a pilot pressure operated control valve, air accumulates in the spring case 4 when the valve is assembled, and if used as it is, the responsiveness is reduced. Therefore, a slit 7 is formed at the end of the spool 3 so that the pilot pressure can be reduced during use. Pressure receiving chamber 6
When the pilot pressure oil is supplied through the pilot line 8 and the spool 3 is moved to the left, the pilot pressure receiving chamber 6 communicates with the tank port 9 through the slit 7, and together with the pilot pressure oil, the pilot pressure receiving chamber 6 Air to tank port 9
To be discharged to

[0003]

With such an air bleeding structure, when the pilot pressure control valve is installed so that the spool 3 is oriented vertically as shown in FIG. As a result, the air at the bottom wall corner 6a of the pilot pressure receiving chamber 6 of the spring case 4 remains without being exhausted, and the air cannot be completely removed. That is, the bottom wall 6b of the pilot pressure receiving chamber 6 of the spring case 4
Has a flat surface for supporting the spring 5, and a through-hole 11 communicating the pilot pressure introduction port 10 and the pilot pressure receiving chamber 6 is formed at a position deviated from the axial center of the spool 3. Air remains in the wall corner 6a.

Therefore, an object of the present invention is to provide a pilot-pressure-operated control valve capable of solving the above-mentioned problems.

[0005]

Means for Solving the Problems A through hole for communicating the pilot pressure introduction port of the spring case with the pilot pressure receiving chamber is provided.
A tapered slit with a width that is gradually increased from the pilot pressure introduction port side to the pilot pressure receiving chamber.

[0006]

[Operation] Even if the spool is installed vertically, the pilot pressure oil flows to the bottom wall corner, so the air in the pilot pressure receiving chamber can be completely exhausted.

[0007]

[Embodiment] An embodiment of the present invention will be described with reference to FIGS. The same members as those in the related art have the same reference numerals.
A through-hole 11 communicating the pilot pressure receiving chamber 6 of the spring case 4 with the pilot pressure introducing port 10 is formed in a tapered slit shape gradually widening from the pilot pressure introducing port 10 side toward the pilot pressure receiving chamber 6 so as to form a bottom wall corner 6.
a. Thus, even if the pilot pressure control valve is installed so that the spool 3 is vertically oriented as shown in FIG. 5, the pilot pressure oil flows through the bottom wall corner 6a. Air can be completely exhausted.

[0008]

The pilot pressure oil flowing into the pilot pressure introduction port 10 flows through the tapered slit-shaped through hole 11 to the bottom wall corner 6b of the pilot pressure receiving chamber 6, so that the spool 3 is oriented vertically. In this case, the air in the pilot pressure receiving chamber 6 can be completely discharged.

[Brief description of the drawings]

FIG. 1 is a sectional view of a conventional pilot pressure operated control valve.

FIG. 2 is an explanatory diagram of an air discharging operation.

FIG. 3 is a sectional view of the pilot pressure control valve of the present invention.

FIG. 4 is an enlarged view of a spring case portion.

FIG. 5 is a sectional view taken along line AA of FIG. 4;

[Explanation of symbols]

1 Valve body, 3 spool, 4 spring case, 5
Spring, 6 pilot pressure receiving chamber, 6a bottom wall corner, 7 slit, 10 pilot pressure introduction port, 1
1 through hole.

Claims (1)

(57) [Scope of request for utility model registration] 1. A spring 5 is provided in a spring case 4 attached to a valve body 1 to urge and hold a spool 3, and a pilot pressure oil is supplied to a pilot pressure receiving chamber 6 in the spring case 4 so that the spool 3 is supplied. In a pilot pressure operated control valve that moves against the spring 5, a through hole 11 that communicates the pilot pressure introduction port 10 of the spring case 4 with the pilot pressure receiving pressure 6 is provided in the pilot pressure introduction port 1
A pilot pressure-operated control valve having a tapered slit shape gradually widening from the 0 side toward a pilot pressure receiving chamber 6.