JPS61241584A - Valve apparatus - Google Patents

Abstract

PURPOSE:To obtain the superior sealing performance without damaging the surfaces of a valve piece and a valve seat by providing a limit for the advance of the valve piece and reducing the force applied onto the sealed surface. CONSTITUTION:In the opened valve state, the large diameter part 30 of a valve piece 28 departs from the shoulder surface 56, and the large diameter part 66 of a cylindrical member 62 is attached onto the bottom surface of a large- diameter hole part 68. When the logic valve is closed to cut off a liquid passage, an electromagnetic direction selector valve 54 is switched to the state shown in the right, and a pilot pressure chamber 42 is connected to a pump to supply a liquid pressure, and then the valve piece 28 is advanced, and the tapered surface 60 contacts with a tapered surface 70. Then, the valve piece 28 advances until the edge surface 55 contacts with the shoulder surface 56, retreating the coil cylindrical member 62 against the urging force of a compression spring 72, and in this state, sealing is performed by a valve seat 26 pressed onto the valve piece 28 by the liquid pressure on the port 24 side, and a flow passage is cut off.

Description

TECHNICAL FIELD The present invention relates to a valve device, and in particular to improving the durability of a valve seat and a sealing surface of a valve element seated on the valve seat.

A type of conventional technology valve device includes a housing with an internal liquid passage,
a valve seat provided with a first sealing surface and provided in the middle of the liquid passage; a valve that seats on the valve seat at a second sealing surface to block the liquid passage; and a second sealing surface of the valve. Some types include a hydraulic pressure chamber that applies hydraulic pressure to a pressure receiving surface facing in the opposite direction, and the opening/closing state can be changed in response to changes in the hydraulic pressure.

Problems to be Solved by the Invention Generally, in a valve device in which a valve element seats on a valve seat to shut off a liquid passage, the valve element and the valve seat are in linear contact in order to improve sealing performance. However, in hydraulic valve devices, the valve element is pressed against the valve seat by a strong force based on hydraulic pressure, so the sealing surface is likely to be damaged during repeated opening and closing, making it difficult to maintain good sealing performance over a long period of time. The problem is that it is difficult to maintain.

In order to solve this problem, Japanese Utility Model Publication No. 59-31968 discloses that in a valve device, the contact portion of the valve head against the valve seat is formed of a rubber-like elastic member, and the contact portion and the valve seat of the valve seat are in contact with each other. It is described that the angle between the seat surface and the seat surface can be changed, but as mentioned above, the force with which the valve element is pressed against the valve seat is strong, so the seat surface of the valve seat has to be widened, and the liquid flow There was a problem that the road area was reduced.

In the present invention, if an attempt is made to improve the sealing performance as described above, it becomes difficult to maintain the good sealing performance for a long period of time, and in order to solve such difficulties, the flow path area of the liquid is increased. This was done to solve the problem of decrease.

Means for Solving the Problems The present invention provides, for this purpose, a first contact surface and a second contact surface that abut each other and define the limit of movement of the valve element in the direction toward the valve seat, in a valve device having the above-mentioned configuration. Two corner faces are provided at positions away from the first sealing surface and the second sealing surface of the housing and the valve, respectively, and at least one of the first sealing surface and the second sealing surface is in contact with the two sealing surfaces. Afterwards, both abutting surfaces can be elastically retracted until they abut each other, and a limit is placed on the forward movement of the valve to reduce the force applied to the sealing surface.

Effects of the Invention As described above, in the valve device according to the present invention, the movement limit of the valve element is defined by the first and second contact surfaces, and the first seal surface and the second seal surface Because at least one of the valve elements is elastically retractable, the large force exerted on the valve element by hydraulic pressure is borne by the housing and not applied to the sealing surface. Therefore, the valve element and the valve seat are only pressed against each other with a force suitable for sealing. Good sealing performance can be obtained without the risk of damage, and there is no need to widen the sealing surface to obtain such good sealing performance, so if the liquid flow path area is small, You can get the effect that you don't have to worry about.

Furthermore, the impact when the valve element seats on the valve seat is alleviated by the receding of the sealing surface, resulting in less damage to the sealing surface.
The effect of improving the life of the valve element and valve seat can also be obtained.

EXAMPLE Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram showing a logic valve that is an embodiment of the present invention, and this logic valve is attached to a hydraulic device (not shown) to open and close a liquid passage in the device. In the figure, 10 is a cylindrical housing body with a bottom, and a sleeve 14 is fitted into the housing body 10 with a spacer 12 interposed between the housing body 10 and a plate 16 at the open end. Fixed by bolt 18,
A housing is configured. A boat 22 is formed in the side wall of the housing body 10 and is connected to the space inside the sleeve 14 through a pair of through holes 20 formed in the side wall of the sleeve 14, while a boat 22 is formed in the bottom wall to communicate directly with the space inside the sleeve 14. A communicating boat 24 is formed. This logic valve is used when the boat 22 is connected to a tank in the hydraulic device, and the boat 24 is connected to a pump passage through which pressure fluid from a pump flows.
2,24. Through hole 20. The space within the sleeve 14 constitutes a liquid passage.

A valve seat 26 and a stepped valve element 28 are disposed within the sleeve 14, and when the valve element 28 is seated on the valve seat 26, the liquid passage is blocked. sleeve 1
The inner peripheral surface of the sleeve 14 is formed into a stepped shape with a larger diameter on the side to which the plate 16 of the housing body 10 is fixed, and the valve element 28 is sealed with an O-ring 32 at its larger diameter portion 30 so that the sleeve 14 has a larger diameter. While being fitted into the diameter hole portion 34,
The small diameter portion 36 is sealed by an O-ring 38 and fitted into the small diameter hole 40 . As a result, a pilot pressure chamber 42 is formed between the large diameter portion 30 and the plate 16, and
An annular hydraulic chamber 44 is formed between the seals of rings 32 and 38, respectively. A liquid passage 48 is connected to the pilot pressure chamber 42 through a port 46 formed in the plate 16, while a through hole 49 formed in the sleeve 14 and a port 50 formed in the housing body 10 are connected to the liquid pressure chamber 44. A liquid passage 52 is connected thereto. The liquid passages 48 and 52 are connected to an electromagnetic directional switching valve 54 to which a pump passage and a tank passage are connected, and the switching valve 54 is switched so that a pump (not shown) (which may be the pump of the hydraulic system) to a pilot The valve element 28 is moved forward and backward by supplying hydraulic pressure to the pressure chamber 42 or the hydraulic pressure chamber 44.

That is, hydraulic pressure is supplied to the hydraulic pressure chamber 42, and the hydraulic pressure is applied to the pressure receiving surface of the valve element 28 (the end surface of the large diameter section 30 on the opposite side from the side from which the small diameter section 36 is extended). This allows the valve element 28 to move forward toward the valve seat 26, but this advancement of the valve element 28 causes the end surface 55 of the large diameter section 30 on the small diameter section 36 side to touch the shoulder surface of the housing body 10. 5
6. In this embodiment, the shoulder surface 56 and the end surface 55 function as a first contact surface and a second contact surface, respectively.

Furthermore, a protrusion 58 having a smaller diameter is provided on the end face of the smaller diameter portion 36 of the valve element 28 . The outer circumferential surface on the distal end side of the protrusion 58 is a tapered surface 60 whose diameter decreases at the distal end side.

Further, the valve seat 26 is provided on the opposite side of the small diameter hole 40 from the side communicating with the large diameter hole 34 . Valve seat 26
The cylindrical member 62 made of hard rubber is slidably fitted into the small diameter hole 40. This cylindrical member 62
is a stepped member, and its small diameter portion 64 is fitted into the small diameter hole 40, and its large diameter portion 66 is fitted into a large diameter hole 68 formed on the opening side of the small diameter hole 40. ing. A tapered surface 70 that substantially corresponds to the tapered surface 60 and has a slightly smaller taper than the tapered surface 60 is formed on the inner circumferential surface of the tip end of the small diameter portion 64, and the valve element 28 is connected to the valve seat 2.
6, the tapered surface 60 becomes the tapered surface 70.
and blocks the liquid passage. These tapered surfaces 60
The tapered surface 70 functions as a second sealing surface and a first sealing surface, respectively.

Further, the cylindrical member 62 is biased toward the valve element 28 by a compression coil spring 72 disposed between the cylindrical member 62 and the spacer 12 . The movement of the cylindrical member 62 due to the bias of the spring 72 is determined by the contact of the large diameter portion 66 with the shoulder surface of the large diameter hole 68, but this movement limit is determined by the large diameter portion 66. When the valve element 28 is moved toward the valve seat 26 while in contact with the bottom surface of the large diameter hole 68, the tapered surface 60 becomes a tapered surface before the end surface 55 of the large diameter portion 30 contacts the shoulder surface 56. 70. Note that 74 is a hole provided radially penetrating the boundary between the small diameter portion 64 and the large diameter portion 66, and this hole 74 provides a hole between the large diameter portion 66 and the bottom surface of the large diameter hole portion 68. The space 69 of the space 69 and the space inside the cylindrical member 62 are communicated with each other to allow the flow of liquid, so that when the cylindrical member 62 moves, the liquid in the space 69 can freely go in and out, and The pressure within this space 69 is always the same as the hydraulic pressure within the cylindrical member 62.

In the logic valve configured as described above, when the valve is open, the large diameter portion 30 of the valve element 28 is separated from the shoulder surface 56, while the large diameter portion 66 of the cylindrical member 62 is separated from the large diameter hole 68. It is in contact with the bottom. When closing this logic valve to cut off the liquid passage, the electromagnetic directional control valve 54 is switched to the state shown on the right, and the pilot pressure chamber 42 is connected to the pump to supply liquid pressure. is brought forward;
First, the tapered surface 60 contacts the tapered surface 70. after that,
The valve element 28 moves the cylindrical member 62 backward against the biasing force of the compression coil spring 72 while the end surface 55 is aligned with the shoulder surface 56.
In this state, the valve seat 26 is pressed against the valve element 28 by the hydraulic pressure on the port 24 side, creating a seal and blocking the liquid passage.

In this way, in the logic valve of this embodiment, the valve element 28
The movement of the large diameter section 30 is stopped when the large diameter section 30 comes into contact with the shoulder surface 56, so the large force, which is the product of the pilot pressure applied to the pressure receiving surface of the large diameter section 30 and the area of the large diameter section 30, is It is received by the end surface 55 of the section 30 and the shoulder surface 56 of the large diameter hole section 34, and excessive surface pressure is not applied to the tapered surfaces 60 and 70, which are sealing surfaces. Valve seat 2
The biasing force of a spring 72 and the hydraulic pressure on the boat 24 side are applied to the valve seat 26.
The valve is activated by a force that is the sum of the hydraulic pressure on the boat 24 side and the biasing force of the spring 72 applied to the projected area of the annular portion between the contact portion with the tapered surface 60 and the outer peripheral surface of the small diameter portion 64. child 28
It will only be forced on you. Therefore, the tapered surface 6
The surface pressure on the abutting surfaces between the valve seat and the valve element 70 is small, and unlike conventional methods, excessive surface pressure acts on the abutting surfaces or sealing surfaces between the valve seat and the valve element, causing damage to those surfaces. This problem does not occur, and good sealing performance is obtained because the sealing pressure on the sealing surface increases and decreases with the liquid pressure.

Further, since the cylindrical member 62 forming the valve seat 26 is made of rubber and is capable of retreating against the biasing force of the compression coil spring 72, the tapered surface 60 is in contact with the tapered surface 70. The impact at this time is alleviated by the elastic deformation and retreat of the cylindrical member 62 itself, and the protrusion 58 and the cylindrical member 62 are less likely to be damaged.

Furthermore, even if a fragile material such as ceramics is used as a corrosion-resistant, wear-resistant, or cavitation-resistant erosion material for the tapered surface 60, elastic deformation of the cylindrical member 62 forming the valve seat 26 and When the valve 28 is seated by retreating, etc., the (h impact) is alleviated, so the valve 2
8 will not be damaged by the impact when it is seated on the valve seat 26.

Note that the logic valve in the above embodiment opens and closes the liquid passage, but by providing an adjustable stopper behind the valve element and regulating the movement of the valve element, the opening degree of the valve can be adjusted. The present invention can also be applied to a type of logic valve that controls the flow rate of a liquid passage, and a type of logic valve that controls the pressure of a liquid passage by controlling the magnitude of pilot pressure applied to a valve element. Furthermore, in addition to pilot pressure type valves, the present invention can be applied to valve devices of a type in which hydraulic pressure is applied to a valve element in a direction to seat it on a valve seat.

For example, the present invention can be applied to a check valve as shown in FIG. In this check valve, a valve seat 80 is placed in a bottomed hole 78 formed in the housing body 76.
A bottomed cylindrical valve element 82 is slidably fitted therein, and the housing main body 76 is closed by the plate 84 to form a hydraulic chamber 86 between the housing body 76 and the valve element 82 . The valve element 82 is fitted with its opening side facing the hydraulic pressure chamber 86, and a communication hole 87 is formed in the bottom wall to communicate the space within the valve element 82 and the space within the bottomed hole 78. The liquid flows in and out of this communication hole 87, allowing movement of the valve element 82, and
The hydraulic pressure in both spaces is made equal. This valve element 82 is normally seated on the valve seat 80 by a compression coil spring 88 disposed between its bottom wall and a plate 84, and the boats 90 and 9 formed in the housing body 76 are normally seated on the valve seat 80.
It is biased in the direction of cutting off communication with 2. Also, Benko 8
2 has a stepped shape similar to the valve 28, and its large diameter portion 9
The end surface 96 of 4 is a shoulder surface 9 formed on the housing body 76.
The forward movement of the valve element 82 is regulated by contacting the valve element 8, and a tapered surface 100 is formed on the outer circumferential surface of the distal end portion.

On the other hand, the valve seat 80 is constituted by a cylindrical member 102 made of hard rubber, similar to the valve seat 26 of the previous embodiment, and has a slightly tapered surface on the inner peripheral surface on the side facing the valve element 82. A tapered surface 104 with a small taper is formed and is biased toward the valve element 82 by a compression coil spring 106. The movement of the cylindrical member 102 due to the bias of the spring 106 is caused by the movement of the large diameter portion 108 of the cylindrical member 102.
This movement limit is determined by the movement of the valve 8 when the large diameter portion 108 is in contact with the shoulder surface 110 formed on the housing body 76.
2 is moved toward the valve seat 80, the tapered surface 1
00 is determined to be in contact with the tapered surface 104.

In the check valve configured as above, when the hydraulic pressure on the boat 92 side becomes higher than that on the boat 90 side,
Due to the hydraulic pressure difference, the cylindrical member 102 pushes the spring 10
6 and the valve element 84 are moved back while compressing the springs 88, respectively, and the valve element 82 and the valve seat 80 are separated, allowing liquid to flow from the boat 92 side to the boat 90 side.

When the pressure on the boat 90 side is high and the pressure on the boat 92 side is low, liquid flows from the communication hole 87 into the space inside the valve 82 and the hydraulic pressure chamber 86, and the hydraulic pressure inside the hydraulic chamber 86 becomes high. 82 is advanced.

At this time, after the tapered surface 100 formed on the valve element 82 comes into contact with the tapered surface 104 formed on the cylindrical member 102,
The valve element 82 resists the biasing force of the compression coil spring 106 and moves the cylindrical member 102 backward while the end surface 96 is aligned with the shoulder surface 9.
The boat is moved forward until it comes into contact with the boats 90 and 92, thereby cutting off communication between the boats 90 and 92, thereby alleviating the impact. Also, Benko 8
2 is received by the shoulder surface 98, and the valve element 82 and the cylindrical member 102 are
Since the tapered surfaces 100 and 104 are only pressed by a force based on the hydraulic pressure, an excessive surface pressure is not applied to both tapered surfaces 100 and 104, and a good sealing function can be obtained.

In addition, in the above two embodiments, the cylindrical member 62.10
2 was supposed to be slidable, but the compression coil springs 72 and 106 were omitted, and the cylindrical member was
After the tapered surfaces 60, 100 and 70, 104 come into contact, the movement of the large diameter portions 30, 94 until they come into contact with the shoulder surfaces 56, 98 is absorbed by their own elastic deformation. It is also possible to use such a cylindrical member as a valve seat by fixing it to a seat provided on the sleeve 14 or the inner peripheral surface of the housing body 76.

Furthermore, an elastic body such as rubber is fixed to the tapered surface 60.100 of the valve element 28.82, and the valve element 28.8 after the tapered surfaces 60, 100 and 70, 104 come into contact with each other due to the bending of the elastic body.
It is also possible to allow the movement of the valve seat 2 and to use it in combination with the valve seats of some of the embodiments described above.

Although not illustrated in detail, the present invention can be implemented in various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a front sectional view showing a logic valve which is an embodiment of the present invention. FIG. 2 is a front sectional view showing a check valve according to another embodiment of the present invention. 26: Valve seat 28: Valve element 30: Large diameter part 42: Pyrosoto pressure chamber 55: End surface (second contact surface) 56: Shoulder surface (first contact surface) 60: Tapered surface (second seal surface) 62: Cylinder Shape member 70: Tapered surface (first sealing surface) 72: Compression coil spring 80: Valve seat 82: Valve element 86: Hydraulic pressure chamber 96: End surface 98: Shoulder surface 100: Tapered surface 102: Cylindrical member 104: Tapered surface 106: Compression coil spring

Claims (1)

[Scope of Claims] A housing having a liquid passage therein, a valve seat provided with a first sealing surface and provided in the middle of the liquid passage, and a second sealing surface seated on the valve seat to accommodate the liquid. A valve device including a valve that blocks a passage, and a hydraulic chamber that applies hydraulic pressure to a pressure receiving surface opposite to a second sealing surface of the valve, the valve device being in contact with each other to close the valve of the valve. A first abutting surface and a second abutting surface that define the limit of movement in the direction toward the seat are provided at positions separated from the first sealing surface and the second sealing surface of the housing and the valve element, respectively, and A valve device characterized in that at least one of the sealing surface and the second sealing surface is capable of elastically retracting after the two sealing surfaces come into contact until the two contacting surfaces come into contact with each other.