JPS6144046Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a relief valve for an oil pump employed in vehicles and the like.

FIG. 1 shows a conventional relief valve.

The valve piston 2 is urged by a spring 5 in a direction to close the relief hole 4, and determines the operating set pressure of the relief valve.

At this time, when the pressure in the oil circuit (not shown) increases and the pressure in the passage 3 reaches the set pressure, the valve piston 2 opens the relief hole 4 and relieves some or all of the oil to the return side. At the same time, the pressure in the passage 3 drops rapidly, and the valve piston 2 suddenly moves in the direction of closing the relief hole 4 due to the biasing force of the spring 5, causing the valve piston 2 to collide with the body 1.

As described above, the relief valve has the disadvantage that the valve piston collides with the body due to movement following the pulsations generated within the oil circuit, causing abnormal noise.

The present invention aims to prevent the above drawbacks by suppressing the vibration of the relief valve.
The technical means devised to achieve the above purpose are:
When the relief hole is in a closed state, an oil damper chamber is formed between the passage and the relief hole by the body and the valve piston.

With the above means, collision of the valve piston with the body can be alleviated, and abnormal noise can be suppressed.

Next, an embodiment of the present invention will be described based on FIGS. 2 to 4.

Figure 2 shows the state when the relief valve 10 is installed.
Figure 3 shows the state immediately before the relief hole 14 is opened.
FIG. 4 shows a state in which the relief hole 14 is fully opened.

Valve piston 12 slidably within body 11
is provided, and the body 11 has a relief hole 14. Valve piston 12 is spring 1
5 in the direction of closing the relief hole 14 and determines the operating setting pressure. The other end of the spring 15 is supported by a retainer 16 and a snap spring 17.

Furthermore, a stepped small diameter portion 20 provided on the stepped inner circumferential wall 19 of the body 11 and the outer circumference of the valve piston 12
An oil damper chamber 13 is constituted by the above.

In FIG. 2, when the pressure in the oil circuit (not shown) increases and the pressure in the passage 18 increases, the valve piston 12 moves to the right in the figure. Along with this movement of the valve piston 12, the oil damper chamber 1
3 also increases, and when the state shown in FIG. 3 is reached, the volume of the oil damper chamber 13 is at its maximum.

When the oil pressure further increases, the relief hole 14 opens and relieves the oil to the return side.

At this time, if the pressure of the oil existing in the passage 18 is high, the opening degree of the relief hole 14 will be widened and the amount of oil to be relieved will also increase. Figure 4 shows the relief hole 1.
4 shows the fully opened state.

At the same time as the oil is relieved, the oil pressure in the passage 18 rapidly decreases, and the valve piston 12 rapidly tries to return to the state shown in FIG. 2 due to the biasing force of the spring 15. At this time, when the valve piston 12 returns to the state shown in FIG. 3, the oil damper chamber 13 is formed again and the oil damper chamber 13 becomes more effective. That is, the oil sealed in the oil damper chamber 13 alleviates the sudden return of the valve piston 12, thereby alleviating the collision of the valve piston 12 with the body 11.

Furthermore, since the return of the valve piston 12 is relaxed, there is a time delay in the return of the valve piston 12, and the pressure in the passage 18 increases before the valve piston 12 is completely returned (the state shown in FIG. 2). The piston 12 starts moving to the right again, suppressing the vibration of the valve piston 12, making it possible to avoid collision between the valve piston 12 and the body 11, and further reducing the occurrence of abnormal noise.

As described above, by creating an oil damper chamber between the passage and the relief hole, abnormal noise can be suppressed, and
Since the oil in the passage can be used as damper oil, there is no need to provide any other damper structure. Therefore, it is possible to perform damper action and pressure regulation control using only the body, valve piston, and spring.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a conventional oil pump relief valve, Figs. 2 to 4 are sectional views of the oil pump relief valve of the present invention, and Fig. 2 is a state in which the oil pump relief valve is installed. , 3rd
The figure shows the state immediately before the relief hole is opened, and FIG. 4 shows the state where the relief hole is fully opened. 11...Body, 12...Valve piston, 1
3...Oil damper chamber, 15...Spring.

Claims (1)

[Scope of utility model registration request] A passage provided in the body, a relief hole communicating with the passage, a valve piston that slides in the body to open and close the relief hole, and a spring housed in the body to bias the valve piston toward the passage. A relief valve for an oil pump comprising: an oil damper chamber formed by the body and the valve piston between the passage and the relief hole when the relief hole is in a closed state.