JP2001263516A - Relief valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a relief valve from chattering and sounding. SOLUTION: This relief valve is characterized that an O-ring 5 formed of an elastic body is provided in a valve seat 4 enabling to close a relief hole 3 by receiving a relief ball 2 sprung by a relief spring 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relief valve attached to a hydraulic pressure or a lubrication path of a transmission case of a mobile agricultural machine, a lubrication oil path of an engine, or the like.

[0002]

2. Description of the Related Art In a mode in which a relief ball made of a steel ball is used as a relief valve provided in a hydraulic circuit, a valve seat for receiving the relief ball is made of metal integrally formed with the cylinder of the interior of the relief ball. Abnormal noise is generated by the impact when the relief ball comes into contact with the valve seat.

[0003]

SUMMARY OF THE INVENTION The present invention reduces the occurrence of abnormal noise and chattering due to a relief valve.

[0004]

According to the first aspect of the present invention, an O-ring made of an elastic material is provided on a valve seat 4 capable of receiving a relief ball 2 repelled by a relief spring 1 and closing a relief hole 3. 5 is provided for the relief valve.

According to a second aspect of the present invention, a relief spring 1 is provided.
A check valve 9 is provided on a hydraulic side of an oil hole 8 of a cylinder 7 for actuating a relief piston 6 which is repelled by the pressure relief valve 6. According to the third aspect of the present invention, the oil hole 8 and the relief hole 3 of the cylinder 7 for operating the relief piston 6 repelled by the relief spring 1 are provided.
The relief valve is characterized in that a small hole 10 for letting a small amount of oil escape is provided between the relief valve.

According to a fourth aspect of the present invention, a relief spring 1 is provided.
A relief valve is provided on a side of an oil hole 8 of a cylinder 7 for operating a relief piston 6 resiliently provided with a relief spring 11 for resiliently relieving the relief piston 6 so as to oppose the relief spring 1. And

According to a fifth aspect of the present invention, an oil hole 8 of a cylinder head 12 press-fitted into a cylinder 7 and a piston head 1 of a relief piston 6 housed in the cylinder 7 are provided.
The relief valve is characterized in that the small holes 14 are shifted from each other.

[0008]

According to the first aspect of the present invention, the relief ball 2 is repelled by the O-ring 5 of the valve seat 4 by the relief spring 1, and the oil in the hydraulic circuit is discharged to the outside through the relief hole 3. When the oil pressure in the hydraulic circuit becomes higher than the resilience of the relief spring 1, the relief ball 2 is pushed open from the O-ring 5 and the oil is released from the relief hole 3 and the O-ring. 5 is discharged to the outside through the gap.
For this reason, the relief ball 2 does not directly contact the valve seat 4, is received by the elasticity of the O-ring 5, is buffered, and does not generate a collision sound. Moreover, the structure is simple, and the relief ball can be prevented from being damaged.

According to the second aspect of the present invention, the relief piston 6 is pressed toward the oil hole 8 by the relief spring 1,
In the state where the relief hole is closed, the check ball 9 is freely movable on the hydraulic side of the oil hole 8, but when the hydraulic pressure of the hydraulic circuit rises and becomes higher than the elastic force of the relief spring 1, , The relief piston 6 is pushed open,
The oil is discharged from the oil hole 8 to the outside through the relief hole pushed and opened by the relief piston 6. When the oil passes through the oil hole 8, the oil ball 8 is closed by the check ball 9, so that the oil leaks out, so that the oil leaks out and the occurrence of chattering can be prevented.

According to the third aspect of the present invention, when the relief piston 6 is pushed toward the oil hole 8 by the relief spring 1, the relief circuit 3 and the small hole 10 of the cylinder 7 are changed from the closed state to the hydraulic circuit. When the relief piston 6 is pressed against the relief spring 1 due to the increase in hydraulic pressure of
First, a small hole 10 is opened to discharge a small amount of oil to the outside.
As a result, an increase in the oil pressure can be absorbed and reduced. further,
When the hydraulic pressure is greatly increased or decreased, the relief piston 6 is pressed to open the relief hole 3 so that the small holes 10 and the relief hole 3 allow the oil to flow out or close to the outside. Oil pressure can be kept constant. For this reason, the operation of the relief piston 6 can be performed slowly.

According to the fourth aspect of the present invention, the relief piston 6 of the cylinder 7 has the buffer spring 11 acting against the relief spring 1, so that the relief piston 6 is actuated by an increase in hydraulic pressure. By tuning press,
The relief hole can be smoothly opened, and the push-back operation in which the relief piston 6 is pushed back by the relief spring 1 as the hydraulic pressure decreases is buffered by the action of the buffer spring 11, so that the relief piston 6 can be prevented.

According to the fifth aspect of the present invention, the oil flowing into the cylinder 7 from the oil hole 8 of the cylinder head 12 is supplied to the small hole 14 of the piston head 13 disposed at a position different from the oil hole 8. The oil is discharged to the outside through the oil passage, so that resistance is given to the oil discharge, and the operation of the relief piston 6 can be relaxed to prevent chattering. Moreover,
Since the cylinder head 12 is press-fitted,
The formation of the oil hole 8 at a position different from the position of the small hole 14 of the piston head 13 can be easily performed.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention can be applied to a lubricating oil circuit such as an engine and a transmission case, a hydraulic circuit of a hydraulic working machine, and the like, with respect to a relief valve. The relief valve can be implemented in a hydraulic circuit or the like. The relief valve is a form in which the relief hole is opened and closed by being operated against the relief spring by raising and lowering the hydraulic pressure on the hydraulic circuit side, and includes a steel ball leaf ball form, a piston or plunger form, In any case, chattering and valve noise are eliminated.

Therefore, the first aspect of the present invention is characterized in that an O-ring made of an elastic body is provided on a valve seat capable of receiving a relief ball repelled by a relief spring and closing a relief hole. As a configuration of the relief valve, the relief ball is received by an O-ring to prevent the generation of a collision sound and the damage of the relief ball.

According to a second aspect of the present invention, there is provided a relief valve, wherein a check ball is provided on a hydraulic side of an oil hole of a cylinder for operating a relief piston repelled by a relief spring. The resistance of the check ball to the hydraulic pressure acting on the oil is applied to make the oil flow out gently, thereby preventing chattering.

According to a third aspect of the present invention, there is provided a relief having a small hole for releasing a small amount of oil between an oil hole and a relief hole of a cylinder for operating a relief piston repelled by a relief spring. As a configuration of the valve, a small amount of oil is discharged to the outside from the small hole of the cylinder, so that a sudden pressure change on the relief piston is reduced, and the operation of the relief piston is performed slowly.

According to a fourth aspect of the present invention, a buffer spring for springing the relief piston against the relief spring is provided on the oil hole side of the cylinder for operating the relief piston springed by the relief spring. The operation of the relief piston is buffered by a buffer spring to prevent chattering.

According to a fifth aspect of the present invention, an oil hole of a cylinder head press-fitted into a cylinder and a small hole of a piston head of a relief piston housed in the cylinder are displaced and formed. The relief valve has a configuration in which resistance of the outflow of oil is provided by the oil hole and the small hole, and the operation of the relief piston is relaxed.

[0019]

An embodiment of the present invention will be described with reference to the drawings. The first embodiment is described with reference to FIG.
The invention described in (1) appears. The second embodiment mainly includes
The third embodiment, which is described based on FIGS. 2 and 3 and in which the invention described in claim 2 appears, is mainly described based on FIG. 4 and in which the invention described in claim 3 appears. You. The fourth embodiment will be described mainly with reference to FIG. 5, and the invention of claim 4 appears. The fifth embodiment will be described mainly with reference to FIGS. 6 and 7, and the invention according to claim 5 is realized.

[0020]

Next, a first embodiment will be described with reference to FIG. A hydraulic circuit 16 for passing lubricating oil is formed in a part of the engine body 15, and the hydraulic circuit 16 receives hydraulic pressure from a hydraulic pump (not shown) to circulate the lubricating oil. A relief valve 17 is provided at a position relatively close to the hydraulic pump in the hydraulic circuit 16. The relief valve 17 is connected to, for example, a crankcase 18 in the engine body 15.
And the cylinder 7 is integrally formed, and the relief ball 2, the relief hole 3, the relief spring 1, the O-ring 5, the sleeve 19, and the like are arranged in the cylinder 7.

The oil hole 8 is provided in the head 20 of the cylinder 7.
And communicates with the hydraulic circuit 16. The valve seat 4 is formed in a conical shape on the cylinder 7 side of the oil hole 8 so that the relief ball 2 can be approached. O-ring 5 along the outer periphery of this valve seat 4
Is interposed between the cylinder head 20 and the upper edge of the sleeve 19 fitted on the inner periphery of the cylinder 7. The O-ring 5 is formed of an elastic body such as a rubber material, and can fit the relief ball 2 made of a steel ball.

As described above, the O-ring 5 and the sleeve 19 are fitted in the cylinder 7, and the relief ball 2 is fitted in the sleeve 19 and pressed by the relief spring 1. The lower ends of the sleeve 19 and the relief spring 1 are closed and fixed by a cap 21 fitted to the cylinder 7.

The relief hole 3 is formed over the upper end portion between the cylinder 7 and the sleeve 19, and communicates between the inside of the sleeve 19 and the inside of the crank chamber 18 on the outer periphery of the cylinder 7. When the relief ball 2 is pressed against the O-ring 5 by the pressure of the relief spring 1, the relief ball 2 closes the gap between the oil hole 8 and the relief hole 3, and the oil on the oil hole 8 side is relieved. It does not flow out of hole 3. However, when the oil pressure on the hydraulic circuit 16 side rises and becomes larger than the pressure of the relief spring 1, the relief ball is pushed down against the relief spring 1 and separates from the O-ring 5, so that the O-ring 5 and the relief ball The fluid is communicated to the relief hole 3 through the gap between the oil discharge port 2 and the oil discharge operation.

With such a configuration, the relief ball 2 moves up and down in the O-ring 5 due to the pressing force of the relief spring 1 and the fluctuation of the hydraulic pressure in the hydraulic circuit 16 to perform the relief operation. Therefore, the relief ball 2 does not directly collide with the valve seat 4. Also, chattering of the relief ball 2 can be prevented by receiving the elastic force of the O-ring 5.

Also, since the O-ring 5 is pressed and fixed to the cylinder head 20 side by the sleeve 19 in the cylinder 7, assembly and disassembly are easy, and the position of the O-ring 5 relative to the relief ball 2 is stabilized. Performance can be stabilized.

[0026]

Second Embodiment Differences from the above embodiment will be described mainly with reference to FIGS. 2 and 3, focusing on the second embodiment. Relief valve 17
The screw 22 of the upper end of the cylinder 7 is
It is configured to be screwed to the part and attached. A relief piston 6 is fitted into the cylinder 7 so as to be movable up and down, and is resiliently pushed toward the oil hole 8 by the relief spring 1 to form a piston. A ball chamber 23 communicating with an oil hole 8 formed in the valve seat 4 is formed at the upper end of the cylinder 7.
A check ball 9 made of a steel ball is movably accommodated in the ball chamber 23, and a C-shaped ring 24 is provided on an upper portion to regulate a play area of the check ball 9.

In this manner of mounting the cylinder 7, the upper end opening 25 of the ball chamber 23 communicates with the hydraulic circuit 16. When the oil from the hydraulic circuit 16 flows into the ball chamber 23, the check ball 9 is in a freely movable state, so that the relief piston 6 can be pressed through the oil hole 8 (FIG. 2). When the relief piston 6 is pushed down against the relief spring 1 due to an increase in the oil pressure, the relief hole 3 is opened as shown in FIG. 3 and the oil is discharged from the relief hole 3 into the external crank chamber 18. You.

At this time, the oil flow in the ball chamber 23 is maintained at a low speed by the throttle action in the relief hole 3 and the oil flow resistance by the check ball 9 on the oil hole 8. The change in the hydraulic pressure in the circuit 16 does not directly act on the relief piston 6, and chattering of the relief piston 6 can be prevented.

[0029]

Third Embodiment Next, the points different from the above example will be described mainly with reference to FIG. The valve seat 4 is
It is attached to the upper end of the cylinder 7 as a ring form. A small hole 10 is formed between the oil hole 8 formed in the valve seat 4 and the relief hole 3 formed in the lower part. The small holes 10 are smaller in diameter than the relief holes 3 and can discharge a small amount of oil. When the relief piston 6 is at the top dead center, the small hole 10 is also closed. However, when the relief piston 6 is slightly pushed by the increase in the hydraulic pressure in the hydraulic circuit 16, the small hole 10 is opened and a small amount of oil flows out.

When the oil pressure further increases from this state,
The relief hole 3 is also opened by the downward movement of the relief piston 6, and the oil is also discharged from the relief hole 3. When the oil pressure of the hydraulic circuit 16 rises above a certain level, a small amount of oil is constantly discharged from the small holes 10, so that a rapid change in oil pressure can be absorbed, and the relief piston 6 removes the valve seat 4 from the valve seat 4. Hitting is reduced.

[0031]

[Fourth Embodiment] Next, a fourth embodiment will be described mainly with reference to FIG. The cylinder 7 is fitted in a relief housing 26 integrally formed with the engine body 15 as a sleeve. The relief piston 6 in the cylinder 7 has the buffer spring 11 interposed in the oil chamber 27 between the cylinder head 12 and the piston head 13, and resiliently urges the relief piston 6 against the relief spring 1. This buffer spring 11 is set weaker than the relief spring 1.

When the hydraulic pressure of the hydraulic circuit 16 is below a certain level, the relief hole 3 is in a closed state. However, when the hydraulic pressure increases, the relief piston 6 is pushed down against the relief spring 1 and the relief hole 3 is turned off. Opened, relief action. Further, when the relief piston 6 is moved upward due to a decrease in the hydraulic pressure, the operation of the relief piston 6 is slowed down because the relief piston 6 is operated against the buffer spring 11, so that chattering can be prevented.

[0033]

Fifth Embodiment The differences from the above embodiment will be described mainly with reference to FIGS. 6 and 7, focusing on the fifth embodiment. First, in FIG. 6, the cylinder head 12 has a disk shape and an oil hole 8 formed in the center, and is press-fitted and fixed to the upper end of the cylinder 7. The small hole 14 of the piston head 13 of the relief piston 6 which is preliminarily provided in the cylinder 7 is formed as a small-diameter hole, and is arranged and formed at several locations on the outer peripheral portion where the oil hole 8 of the cylinder head 12 does not overlap. .

When the hydraulic pressure of the hydraulic circuit 16 is below a certain level, the piston head 13 pressed by the relief spring 1 adheres to the cylinder head 12 and no oil is drained from the small hole 14, but the hydraulic pressure increases. By relief piston 6
Is pressed down, a small hole 14 is opened and a small amount of oil is drained. Further, when the relief piston 6 is pushed down by the increase of the oil pressure to open the relief hole 3, the oil is also directly discharged from the relief hole 3 and the relief action is performed. Therefore, the operation of the relief piston 6 is slowed down by the drainage of the oil from the small holes 14, so that chattering can be prevented and the impact force on the cylinder head 12 can be reduced. Particularly at the position where the relief piston 6 is moved down near the top dead center, since the gap between the piston head 13 and the cylinder head 12 is narrow, the resistance of the oil flow flowing from the oil hole 8 toward the small hole 14 is reduced. Large, slow flow rate.

Next, FIG. 7 differs from the above example in that
The oil hole 8 of the cylinder head 12 is arranged at the outer periphery, and the small hole 14 of the piston head 13 is formed at the center.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a relief valve section according to a first embodiment of the present invention.

FIG. 2 is a side sectional view of a relief valve section showing a second embodiment.

FIG. 3 is a side sectional view showing the operation.

FIG. 4 is a side sectional view of a relief valve section showing a third embodiment.

FIG. 5 is a side sectional view of a relief valve section showing a fourth embodiment.

FIG. 6 is a side sectional view of a relief valve section showing a fifth embodiment.

FIG. 7 is a side sectional view and a plan view showing a partially different embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Relief spring 2 Relief ball 3 Relief hole 4 Relief seat 5 O-ring 6 Relief piston 7 Cylinder 8 Oil hole 9 Check ball 10 Small hole 11 Buffer spring 12 Cylinder head 13 Piston head 14 Small hole 17 Relief valve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akihiro Tamura 1st Toyocho Hachikura, Toyo-cho, Iyo-gun, Ehime Prefecture Iseki Agricultural Machinery Co., Ltd. Department F-term (reference) 3H059 AA04 AA08 BB12 BB37 CA17 CB13 CB15 CB17 CB23 CB24 CB27 CD04 CF01 CF09 EE01 FF03 FF13 3H066 AA04 AA06 BA02 BA32 BA34 EA01 EA05 EA12 EA21 EA22 EA23

Claims (5)

[Claims] A valve seat for receiving a relief ball repelled by a relief spring and closing a relief hole.
A relief valve provided with an O-ring 5 made of an elastic material. 2. A relief valve, wherein a check ball 9 is provided on a hydraulic side of an oil hole 8 of a cylinder 7 for actuating a relief piston 6 resiliently released by a relief spring 1. An oil hole (8) and a relief hole (3) of a cylinder (7) for operating a relief piston (6) repelled by a relief spring (1).
A relief hole for allowing a small amount of oil to escape therethrough. 4. A buffer spring 11 for resiliently relieving the relief piston 6 is provided on the side of the oil hole 8 of the cylinder 7 for operating the relief piston 6 resiliently resilient. A relief valve characterized by the following. 5. A cylinder head 1 press-fitted into a cylinder 7.
A relief valve characterized in that the second oil hole 8 and the small hole 14 of the piston head 13 of the relief piston 6 housed in the cylinder 7 are formed at different positions.