JPH09257151A - Poppet valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a poppet valve which is easily manufactured, and in which the pressure override value corresponding to the circuit in which it is to be incorporated is easily regulated by forming a downstream chamber inside a cylinder member as well as by providing a passage hole in the cylinder member, communicating the downstream chamber with an outport. SOLUTION: When the pressure at an inport 2 is elevated exceeding the cranking pressure preset by means of a spring 8, a poppet 6 moves while compressing the spring 8, and opens a seat part 5. When the seat part 5 opens, the pressure oil flows from the inport 2 through the seat part 5 into a downstream chamber 10, and then through a passage hole 11 formed in a cylinder member 9 to an outport 3. Such flowing determines a pressure override value corresponding to the fluid force of the poppet. The flowing direction is varied depending on the location, size or shape of the passage hole 11 formed in the cylinder member 9. The force acting on the poppet depends not only on the flowing direction but also on the flow rate or flow velocity. In addition, it may be regulated by the shape of the poppet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a poppet valve having a poppet, which is used as a relief valve or the like.

[0002]

2. Description of the Related Art In a poppet valve that opens and closes communication between an import formed in a body and an outport with a poppet, the poppet is pressed against a seat portion by an elastic force of a spring. When the oil pressure on the import side exceeds the pressing force of this spring, the poppet moves,
The seat opens. At this time, a fluid force is generated by the flow flowing from the seat portion along the poppet. When the fluid force is generated, the poppet receives a force in the closing direction, which increases the valve resistance. This raises the circuit pressure and increases the pressure override value. The pressure override value is the difference between the pressure at which the poppet moves to start opening the valve (cracking pressure) and the total pressure that is the pressure when the rated flow rate is flown. It is often said that the smaller this value, the higher the efficiency of the circuit and the better the pressure override characteristic. In order to improve the pressure override characteristic, the invention of Japanese Utility Model Publication No. 2-9161 has been made. In the poppet valve of the present invention, the poppet is formed with a collar portion, and the collar portion is formed with an inverted taper surface. The fluid flowing from the poppet opening is made to collide with this reverse taper surface, the flow direction is changed, and the fluid force acting in the poppet opening direction is generated, so that the total force acting in the axial direction of the poppet is seen. If so, the force acting in the direction of closing the poppet is reduced.

[0003]

In such a poppet valve, since the shape of the poppet having the reverse taper surface is complicated and the processing accuracy is required, the manufacturing cost is high. Further, simply reducing the fluid force does not mean that a preferable pressure override characteristic is obtained, and depending on the circuit in which the poppet valve is installed, it may be preferable that the pressure increase even after the valve is opened. That is, since the required pressure override characteristic changes depending on each circuit configuration, it is desired that the pressure override characteristic can be easily adjusted. When adjusting the pressure override characteristic, in the conventional poppet valve described above, the shape of the flange portion of the poppet such as the angle of the reverse taper surface must be changed. Therefore, when adjusting the characteristics, it is necessary to process the collar portion having a complicated shape, which takes time and cost. Therefore, an object of the present invention is to provide a poppet valve which is easy to manufacture and whose pressure override value can be easily adjusted according to a circuit to be incorporated.

[0004]

The poppet valve of the present invention comprises a body, an import formed on the body,
Outports, a flow path communicating between these ports, a seat portion located in the middle of the flow path, a poppet axially movable in the flow path, and the poppet is pressed against the seat portion. In a poppet valve provided with a spring, the poppet has a disc-shaped brim portion perpendicular to the axial direction, a tubular member surrounding the poppet is provided on the downstream side of the seat portion, and the downstream chamber is provided inside the tubular member. Together with forming
The tubular member is provided with a flow path hole that connects the downstream chamber and the outport. A poppet valve like this
Since the shape of the collar is simple, it is easy to manufacture. Further, the flow of the fluid changes depending on the position and size of the flow path hole formed in the tubular member. Therefore, adjust the flow of fluid,
In order to adjust the direction and magnitude of the force that the poppet receives, the position, size, and shape of the flow passage hole may be adjusted. A second invention is characterized in that a proportional solenoid having a push rod for pressing the poppet against the spring is provided on the opposite side of the spring with the poppet of the poppet valve of the above invention as a boundary. The elastic force of the spring can be adjusted remotely by a proportional solenoid.

[0005]

1 and 2 show a present embodiment in which the present invention is applied to a relief valve. The import 2 and the out port 3 formed in the body 1 are formed, and the seat portion 5 is formed in the flow path 4 that connects the ports 2 and 3. The poppet 6 is provided with a poppet 6 for opening and closing the seat portion 5, and a spring 8 for pressing the poppet 6 against the seat portion 5. The poppet 6 is formed with a disc-shaped brim portion 7 which is perpendicular to the axial direction, and the poppet 6 is provided on the downstream side of the seat portion 5.
A tubular member 9 that surrounds the downstream port 10 is formed inside the tubular member 9, and a channel hole 11 that connects the downstream chamber 10 and the outport 3 is provided in the tubular member 9.
The spring 8 is provided with an adjuster 14 for adjusting elastic force, and a proportional solenoid 12 having a push rod 13 is provided on the opposite side of the adjuster 14. The push rod 13 is brought into contact with the end of the poppet 6 via the relay member 16. The reference numeral 15 in the figure
It shows a wave washer.

Next, the operation of this relief valve will be described.
When the pressure of the import 2 becomes high and the pressure exceeds the cracking pressure set by the spring 8, the poppet 6
Moves by pressing and contracting the spring 8 to open the seat portion 5. When the seat part 5 is opened, the pressure oil is
It passes through the seat portion 5, flows into the downstream chamber 10, and flows out from the flow path hole 11 formed in the tubular member 9 to the outport 3. The flow that flows from the import 2 side through the seat portion 5 into the downstream chamber 10 flows along the poppet 6 as indicated by an arrow a in FIG. As the angle between this flow and the axis of the poppet 6 becomes smaller, that is, as the direction of the flow approaches the direction parallel to the axis of the poppet 6, the fluid force in the direction in which the poppet 6 closes increases, From the upstream, the force b in the direction of opening the poppet 6 acts on the collar portion 7 due to the flow b colliding with the collar portion 7. As a result, the force acting in the direction of closing the poppet 6 decreases. Further, the flow c in the direction perpendicular to the axis, which collides with the collar portion 7 and changes the flow direction, does not generate a fluid force in the axial direction of the poppet 6.

The pressure override value due to the fluid force of the poppet 6 is determined by these flows. The flow direction is determined by the position of the flow path hole 11 formed in the tubular member 9,
It depends on the size and shape. The force acting on the poppet is not only determined by the flow direction, but is also affected by the flow rate and flow velocity. This flow can be adjusted by the position, size, and shape of the flow path hole 11.

The cracking pressure of the poppet valve is set by the spring 8. By operating the adjuster 14, the elastic force of the spring 8 is adjusted, and the force F1 by which the spring 8 presses the poppet 6 against the seat portion 5 is set. On the other hand, the push rod 13 is the proportional solenoid 1
A thrust force proportional to the current applied to 2 is generated, and this thrust force is designated as F2. The cracking pressure is determined by the force difference (F1−F2) (where F1> F2). F1
Is a value adjusted by the adjuster 14 directly connected to the spring 8, but F2 can be adjusted by the current value applied to the proportional solenoid 12. That is, the cracking pressure can be set remotely.

Further, generally, when the flow velocity of the pressure oil flowing into the downstream chamber is high, a negative pressure is likely to be generated on the downstream side of the collar portion 7.
When a negative pressure is generated in the downstream chamber 10, air bubbles are generated in the oil, or the poppet vibrates due to cavitation, which causes noise. However, in the poppet valve of the present invention, since the downstream chamber 10 is surrounded by the tubular member 9, the pressure therein becomes high, and the negative pressure hardly occurs. As a result, noise due to cavitation etc. was reduced.

[0010]

According to the poppet valve of the present invention, the collar portion formed on the poppet has a simple shape and is easy to process. Further, the tubular member forming the downstream chamber has a simple shape, and the cost of parts can be reduced. The pressure override characteristic of the poppet valve can be adjusted by changing the position, size, and shape of the flow passage hole formed in the tubular member, which facilitates the adjustment.
Furthermore, since the structure is such that negative pressure is unlikely to occur in the downstream chamber, noise due to cavitation etc. could be reduced. In the second aspect of the invention, the cracking pressure can be set by remote control using a proportional solenoid.

[Brief description of drawings]

FIG. 1 is a sectional view of the present embodiment.

FIG. 2 is a partially enlarged view of the present embodiment.

[Explanation of symbols]

 1 Body 2 Import 3 Outport 4 Flow Path 5 Seat 6 Poppet 7 Collar 8 Spring 9 Cylindrical Member 10 Downstream Chamber 11 Flow Hole 12 Proportional Solenoid 13 Push Rod

Claims (2)

[Claims] 1. A body, an import port and an out port formed in the body, a flow path connecting these ports, a seat portion located in the middle of the flow path, and an axial movement in the flow path. In a poppet valve equipped with a poppet that can be installed and a spring that presses the poppet against the seat portion, a disc-shaped brim portion that is perpendicular to the axial direction is formed on the poppet, and the poppet is provided on the downstream side of the seat portion. A poppet valve, characterized in that a surrounding cylindrical member is provided, a downstream chamber is formed inside the cylindrical member, and a flow passage hole that connects the downstream chamber and the outport is provided in the cylindrical member. 2. The poppet valve according to claim 1, wherein a proportional solenoid having a push rod for pressing the poppet against the spring is provided on the side opposite to the spring with the poppet as a boundary.