JPH0716006U - Fluid pressure equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a fluid pressure device capable of reducing sliding resistance while ensuring sealing performance at the time of piston sliding and at the stroke end. [Structure] Labyrinth seals 17 and 23 are formed on the outer peripheral surfaces of the first and second pistons 16 and 22, respectively, and first and second labyrinth seals 17 and 23 are formed at the ends of the first and second cylinder chambers 15 and 20, respectively.
The seal members 18, 24 made of an elastic body with which the pistons 16, 22 come into contact at the stroke end are provided. According to this fluid pressure device, the labyrinth seal 1 is used when sliding.
The seal action of the seal members 18, 24 abutting at the stroke end by the seal action of 7, 23
Also, the sealing property of the working fluid between both sides of the second pistons 16 and 22 can be always secured, and at the same time, the sliding resistance at the time of sliding can be significantly reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fluid pressure device, and more particularly to a technique effective for reducing the sliding resistance of a piston in the fluid pressure device.

[0002]

[Prior art]

 A fluid pressure device such as a solenoid valve has a structure in which a seal member is attached to the outer peripheral surface of the piston, and the outer peripheral surface of the piston and the inner peripheral surface of the cylinder chamber are sealed by the seal member. In a fluid pressure device with such a structure, the piston seal member may interfere with the high-speed operation of the piston due to the sliding resistance with which it slides on the inner peripheral surface of the cylinder chamber, sometimes affecting the operation. The wear of the seal member hinders its long life.

Therefore, as a technique for solving such a problem, for example, as disclosed in Japanese Utility Model Laid-Open No. 2-5602, a seal member which is slidably contacted with the inner peripheral surface of the cylinder chamber is provided on the outer peripheral surface. Not equipped with a piston and a seal member that is provided at the end of this cylinder chamber and that makes contact with the piston at the stroke end of the piston. The contact of the piston with the seal member causes the working fluid to flow between both sides of the piston. It is known to seal.

[0004]

[Problems to be solved by the device]

 According to this method, since there is no seal member on the outer peripheral surface of the piston, sliding resistance is reduced and wear of the seal member cannot occur. However, since no seal member is provided on the outer peripheral surface, mutual flow of the working fluid between both sides of the piston is blocked only when the seal member comes into contact at the stroke end, and the sealability during sliding is reduced. There was a problem.

Therefore, an object of the present invention is to provide a technique related to a fluid pressure device capable of reducing sliding resistance while ensuring sealing performance at the time of piston sliding and at the stroke end.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0007]

[Means for Solving the Problems]

 The outline of a typical one of the inventions disclosed in the present application will be briefly described as follows.

That is, the fluid pressure device of the present invention includes a piston having a labyrinth seal formed on an outer peripheral surface of the cylinder chamber, which is in sliding contact with the inner peripheral surface of the cylinder chamber, and a stroke provided on at least one end of the cylinder chamber. And a seal member with which the piston abuts at the end. The sliding action of the labyrinth seal during sliding and the contact of the piston with the seal member at the stroke end prevent the working fluid from flowing between the two sides of the piston. Has become.

[0009]

[Action]

 According to the fluid pressure device of the present invention, the mutual operation of the working fluid between the two sides of the piston is prevented by the sealing action of the labyrinth seal when sliding. Further, at the stroke end, the piston abuts against the seal member, and thus the mutual circulation of the working fluid is similarly blocked.

Therefore, not only at the stroke end of the piston but also at the time of sliding, it is possible to secure the sealing property of the working fluid between both sides of the piston, and the labyrinth seal causes the outer peripheral surface of the piston to move to the cylinder chamber. By using a seal material that has a small contact area even if it is not in contact with, or has contact with, sliding resistance during sliding can be reduced.

[0011]

【Example】

 Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a sectional view showing a fluid pressure device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a main part of the fluid pressure device.

First, the configuration of the fluid pressure device in this embodiment will be described.

The present embodiment relates to a switching valve as one of fluid pressure devices, and this switching valve is of a two-position switching system using an elastic body sealing system, and includes a main valve 1 and a pilot valve 2. , And the solenoid section 3 are coaxially connected to each other.

In the main valve 1, a shaft hole 5 is formed in the center of the main valve body 4, and an input port 6, a first and a second discharge port 7, 8, a first and a second port communicating with the shaft hole 5 Second output ports 9, 10 are formed. A spool-shaped main shaft 11 is provided in the shaft hole 5 so as to be displaceable in the axial direction. A small-diameter portion 11a and a large-diameter portion 11b are alternately formed on the main shaft 11, and a lip seal 12 as an elastic body seal is attached to the large-diameter portion 11b.

An annular valve seat portion 1a is formed on the inner peripheral surface of the shaft hole 5 of the main valve 1. The main shaft 11 is axially displaced and the lip seal 12 abuts on the valve seat portion 1a. , The input port 6, the first and second discharge ports 7 and 8, and the communication states of the first and second output ports 9 and 10 are switched so that the flow path of the working fluid is controlled. Has become.

The main pilot passage 13 opened at a position facing the input port 6 of the shaft hole 5 is branched into first and second auxiliary pilot passages 13a and 13b.

The first sub-pilot passage 13a extends leftward in the drawing and opens into the first cylinder chamber 15 inside the end cover 14. Inside the first cylinder chamber 15, there is slidably provided a first piston 16 for urging the main shaft 11 to move rightward in the drawing. As shown in FIG. 2, a labyrinth seal 17 made of, for example, a resin, having a finely pointed tip in the circumferential direction is provided on the outer circumferential surface of the first piston 16 which is in sliding contact with the inner circumferential surface of the first cylinder chamber 15. Has been formed. The labyrinth seal 17 prevents mutual flow of the working fluid between both sides of the first piston 16 during sliding. On the right end side of the first cylinder chamber 15, that is, on the stroke end side in the direction in which the first piston 16 applies a moving force to the main shaft 11, an elastic body with which the first piston 16 abuts is formed. A seal member 18 is mounted so that the seal member 18 prevents mutual flow of the working fluid between both sides of the first piston 16 at the stroke end.

The second sub pilot passage 13 b extends rightward in the drawing and opens in the pilot valve 2.

A second cylinder chamber 20 is formed on the left side of the pilot valve main body 19 provided in the pilot valve 2, and a pilot chamber 21 is formed on the right side thereof. A second piston 22 having a larger pressure receiving area than the first piston 16 is slidably provided in the second cylinder chamber 20, and the second piston 22 allows the second cylinder chamber 20 to move to the left side. It is partitioned into a cylinder chamber 20L and a right cylinder chamber 20R.

Here, a labyrinth seal 23 made of, for example, resin, having a shape similar to that of the first piston 16 is formed on the outer peripheral surface of the second piston 22, and the second piston 22 can be used when sliding. Mutual flow of the working fluid between both sides of 22 is prevented. Further, the second piston 22 also abuts on the left end side of the second cylinder chamber 20, that is, the stroke end side in the direction in which the second piston 22 applies the moving force to the main shaft 11, similarly to the above. A seal member 24 made of an elastic body is attached to prevent mutual flow of the working fluid between both sides of the second piston 22 in the stroke end.

The left cylinder chamber 20L communicates with the pilot discharge port 25, and the right cylinder chamber 20R also communicates with the pilot discharge port 25 via the first valve seat 26a. Is communicated with the pilot chamber 21 in the pilot valve 2 via the second valve seat 26b.

A communication passage 27 is formed between the right cylinder chamber 20 R and the pilot chamber 21, and a plunger pin 28 is provided in the communication passage 27. The flapper 29 is separated from the first valve seat 26a against the biasing force of the flapper spring 30 by the leftward movement of the plunger pin 28.

The solenoid portion 3 includes a fixed core 32 inside the bobbin 31, and a plunger 33 attracted to the fixed core 32 by magnetic force. The plunger 33 is projected into the pilot chamber 21 and the poppet 34 is attached to the tip end portion thereof. The urging force of the plunger spring 35 causes the poppet 34 to abut against the second valve seat 26b, so that the plunger 33 The tip end surface displaces the plunger pin 28 toward the flapper 29.

A solenoid coil 36 for generating a magnetic force on the fixed core 32 when energized is wound around the outer circumference of the bobbin 31, and the solenoid coil 36 is covered with a solenoid cover 37.

Next, the operation of the fluid pressure device of this embodiment will be described.

FIG. 1 shows a state in which the main shaft 11 is in the right switching position by the urging force of the first piston 16 by the working fluid. In this state, the space formed by the small diameter portion 11a of the main shaft 11 and the shaft hole 5 allows the input port 6 and the first output port 9 to communicate with each other, and the second output port 10 and the second output port 10 The discharge port 8 is connected.

From this state, when an electric current is passed through the solenoid coil 36 of the solenoid unit 3, a magnetic force is generated in the fixed core 32, and the magnetic force causes the plunger 33 to be attracted to the fixed core 32. The second valve seat 26b is opened by the separation of the poppet 34, and the pressing force of the plunger pin 28 to the flapper 29 side is released. As a result, the main shaft 11 is displaced to the left and the flow path of the working fluid is released. Can be switched.

Then, the flapper 29 closes the first valve seat 26a by the urging force of the flapper spring 30 to make the right side fluid chamber 20R airtight, and the auxiliary fluid pressure is supplied to the right side fluid chamber 20R in this airtight state by the communication passage 27. Supplied from Then, the supplied auxiliary fluid pressure displaces the second piston 22 leftward, and accordingly, the main shaft 11 is displaced leftward against the biasing force of the first piston 16 to the left switching position. Stop at.

In the left switching position, the first output port 9 and the first discharge port 7 communicate with each other through the space between the small diameter portion 11a of the main shaft 11 and the shaft hole 5, and the input port 6 and the first discharge port 7 communicate with each other. An operating state in which the two output ports 10 communicate with each other is obtained.

As described above, the first and second pistons 16 and 22 provided in the first and second cylinder chambers 15 and 20, respectively, depending on the displacement of the main shaft 11, slide leftward or rightward. However, as described above, labyrinth seals 17 and 23 are formed on the outer peripheral surfaces of the first and second pistons 16 and 22 in the circumferential direction thereof. Therefore, when the first and second pistons 16 and 22 slide, the labyrinth seals 17 and 23 seal the mutual action of the working fluid between the two sides of the first and second pistons 16 and 22. Will be blocked.

Further, on the right end side of the first cylinder chamber 15 and the left end side of the second cylinder chamber 20, there are mounted seal members 18 and 24 with which the first and second pistons 16 and 22 contact, respectively. Has been done. Therefore, at the stroke ends of the first and second pistons 16 and 22, the seal members 18 and 24 prevent mutual flow of the working fluid between both sides of the pistons 16 and 22, respectively.

That is, according to the fluid pressure device of this embodiment, the labyrinth seals 17 and 23 seal the seal members 18 at the stroke end when the first and second pistons 16 and 22 slide. , 24 prevent mutual flow of the working fluid, so that the sealing property of the working fluid between both sides of the first and second pistons 16 and 22 is always ensured.

Further, by adopting the labyrinth seals 17 and 23, the outer peripheral surfaces of the first and second pistons 16 and 22 are not in contact with or in contact with the first and second cylinder chambers 15 and 20. However, by using a resin material that has a small contact area and high sliding characteristics, the inner peripheral surface of the first and second cylinder chambers 15 and 20 at the time of sliding can be Also, it becomes possible to greatly reduce the sliding resistance generated by the outer peripheral surfaces of the second pistons 16 and 22.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, in the present embodiment, the switching valve as one of the fluid pressure devices has been described using the switching valve of 2 position 5 port type, but the invention is not limited to this, and the fluid pressure using a piston is not limited to this. As long as it is a device, it can be applied to various things.

Further, in this embodiment, the fluid pressure device in which the labyrinth seals 17 and 23 are formed on the outer peripheral surfaces of both the first and second pistons 16 and 22 has been described. In a pressure device, it is not necessary to form the labyrinth seals 17 and 23 on all pistons.

The shapes of the labyrinth seals 17 and 23 are not limited to those shown in FIG. 2 in this embodiment, and one side may be cut out as shown in FIG. 3, for example. Various shapes are conceivable such as a labyrinth seal 47 having a sharpened tip by means of, and a labyrinth seal 57 having a tip as a surface as shown in FIG. Further, although the material is resin in this embodiment, it goes without saying that the material may be other than resin.

Further, in the present embodiment, the seal members 18 and 24 are attached to the right end side of the first cylinder chamber 15 and the left end side of the second cylinder chamber 20, respectively. A seal member may be attached to the left end side of the first cylinder chamber 15 and the right end side of the second cylinder chamber 20.

The fluid pressure device is not limited to one that is operated by air pressure, and one that is operated by hydraulic pressure can also be used.

[0041]

[Effect of device]

 The effects obtained by the representative one of the inventions disclosed in the present application will be briefly described as follows.

(1) That is, according to the fluid pressure device of the present invention, the labyrinth seal is formed on the outer peripheral surface of the piston, and the piston is in contact with the end of the cylinder chamber at the stroke end of the piston. Is provided, the mutual action of the working fluid between the two sides of the piston is blocked by the sealing action of the labyrinth seal during sliding and by the abutment of the piston with the seal member at the stroke end. Will be stopped. Therefore, it is possible to secure the sealing property of the working fluid between the both sides of the piston not only at the stroke end of the piston but also at the time of sliding.

(2) At the same time, the labyrinth seal allows the outer peripheral surface of the piston to be in non-contact with the cylinder chamber, or even if it is in contact, the contact area is small and the sealing material with high sliding characteristics is used. The sliding resistance during sliding can be significantly reduced. Therefore, stable operation of the fluid pressure device can be obtained, and the operation speed can be increased.

(3) Further, since the piston seal made of an elastic body is not required, the number of parts of the fluid pressure device can be reduced and the cost can be reduced.

(4) At the same time, an elastic piston seal, which is significantly worn, is not required, so that the life of the fluid pressure device can be extended.

[Brief description of drawings]

FIG. 1 is a sectional view showing a fluid pressure device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a main part of the fluid pressure device.

FIG. 3 is a cross-sectional view showing a labyrinth seal according to another embodiment of the present invention.

FIG. 4 is a sectional view showing a labyrinth seal which is still another embodiment of the present invention.

[Explanation of symbols]

 1 Main valve 1a Valve seat 2 Pilot valve 3 Solenoid part 4 Main valve body 5 Shaft hole 6 Input port 7 First discharge port 8 Second discharge port 9 First output port 10 Second output port 11 Main shaft 11a Small diameter part 11b Large diameter part 12 Lip seal 13 Main pilot passage 13a First sub pilot passage 13b Second sub pilot passage 14 End cover 15 First cylinder chamber 16 First piston 17 Labyrinth seal 18 Seal member 19 Pilot valve Main body 20 Second cylinder chamber 20L Left side cylinder chamber 20R Right side cylinder chamber 21 Pilot chamber 22 Second piston 23 Labyrinth seal 24 Seal member 25 Pilot discharge port 26a First valve seat 26b Second valve seat 27 Communication passage 28 Plunger Pin 29 flapper 30 flapper ba 31 bobbin 32 fixed core 33 plunger 34 poppet 35 plunger spring 36 solenoid coil 37 solenoid cover 47 labyrinth seal 57 a labyrinth seal

Claims (2)

[Scope of utility model registration request] 1. A piston having a labyrinth seal formed on an outer peripheral surface of the cylinder chamber, the outer peripheral surface of which is in sliding contact with the inner peripheral surface of the cylinder chamber, and at least one end side of the cylinder chamber, the piston contacting at least one stroke end of the piston. And a sealing member in contact with each other, the sliding action of the labyrinth seal when sliding, the contact of the piston with the sealing member at the stroke end, the mutual flow of the working fluid between both sides of the piston, respectively. A fluid pressure device characterized by being blocked. 2. The fluid pressure device according to claim 1, wherein the labyrinth seal is made of resin.