JPH07217753A - Low noise type pilot pressure drive passage switching valve - Google Patents

Abstract

PURPOSE:To reduce the noise generated in switching a passage by narrowing the pilot pressure intake port of a passage switching valve. CONSTITUTION:In the case where a passage mode is of fluid entrance/exit 5 4, pilot fluid flows from a pilot pressure intake port 6, shifting a spool 2 to the right, resulting in switching the current passage mode to 3 5. At this moment, the pilot fluid in the right side of the spool 2 is discharged from a pilot pressure intake port 7, but since the pilot pressure intake port 7 is narrowed, discharge resistance is generated, weakening the collision force of the spool 2 and a valve casing 1. Therefore, the noise generated in collision is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pilot pressure driven flow path switching valve for switching flow paths with low noise.

[0002]

2. Description of the Related Art A conventional pilot pressure drive flow path switching valve is shown in FIG. 01 is a valve box, 02 is a spool, 03, 04,
Reference numeral 05 is a fluid inlet / outlet, 06 and 07 are pilot pressure intake ports, and parallel holes are formed in the pilot pressure intake ports 06 and 07 for moving the spool 02.

[0003]

Since the conventional pilot pressure drive flow path switching valve is constructed as described above, the pilot pressure acts on the spool as it is, and the noise generated by the collision between the spool and the valve body is large. There was a problem.

[0004]

SUMMARY OF THE INVENTION The present invention has solved the above-mentioned problems of the prior art and is one in which the pilot pressure intake port of the flow path switching valve is narrowed as a tapered hole.

[0005]

In the pilot pressure drive flow path switching valve, when the spool is moved, the pilot fluid existing in the direction in which the spool is moving is discharged from the pilot pressure intake port. Since the pilot pressure intake port of the path switching valve is throttled when the spool moves, it serves as a resistance against the discharge of pilot fluid existing in the spool moving direction, and the collision force between the spool and the valve box weakens, and the spool and valve The noise generated in the collision with the box is reduced.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a flow path switching valve that realizes the system of FIG.

In FIG. 1, 1 is a valve box, 2 is a spool,
3, 4 and 5 are fluid inlet / outlet ports, and 6 and 7 are pilot pressure intake ports. The current channel is 5 → 4. Here, the pilot fluid flows in from the pilot pressure intake port 6,
The spool 2 moves to the right, switching the flow path from 3 to 5.

At this time, the pilot fluid on the right side of the spool 2 is discharged from the pilot pressure intake port 7,
Since the pilot pressure intake port 7 is narrowed, it serves as a discharge resistance, and the collision force between the spool 2 and the valve box 1 is weakened. Therefore, noise generated at the time of collision is also reduced.

[0009]

As described above, according to the present invention, since the pilot pressure intake port of the switching valve is tapered, it is possible to obtain the effect of reducing the noise generated when switching the flow paths.

[Brief description of drawings]

FIG. 1 is a sectional view of a flow path switching valve according to an embodiment of the present invention.

FIG. 2 is a schematic system diagram of a flow path switching valve.

FIG. 3 is a sectional view showing a conventional flow path switching valve.

[Explanation of symbols]

 1 Valve box 2 Spool 3, 4, 5 Fluid inlet / outlet 6,7 Pilot pressure inlet

Claims (1)

[Claims] 1. A low noise pilot pressure driven flow path switching valve, wherein in a system for switching the flow path of the flow path switching valve, a pilot pressure intake port of a valve box is narrowed.