JPH04248084A - High pressure valve - Google Patents

Abstract

PURPOSE:To open and close a high pressure valve while using small pilot pressure by converting the linear motion of a piston moved by air pilot pressure into the swing motion of a power lever so that the motion of the piston may be transferred to a slider after boosted. CONSTITUTION:When air pilot pressure P is applied from an inlet hole 28 to a chamber 27, a piston 23 moves down. A power lever 33 is pushed by this moving down and swing around a fixed shaft 34, and the cam face of the fixed shaft 34 moves up a follower, that is, slider 24. This moving up power is boosted depending upon the lever ratio of the power lever 33 determined by the distance between the shaft 34 and a roller 35 and the distance (s) between the cam face 36 and the shaft 34. Therefore, such big power as being capable of opposing to a stacked coned disc spring 32 can be generated by small power only making the piston 23 move down resulting in the rise of a slider 24.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-pressure valve that can be opened and closed with a small pilot pressure.

0002

[Prior art and its problems] Conventionally, such high-pressure valves have, for example, a toggle mechanism or a fluid boosting mechanism interposed between a piston that moves in response to pilot pressure and a valve body that opens and closes a fluid passage. Known as a high pressure valve. However, the former has a large size due to the toggle mechanism, and the latter has a complicated structure due to the fluid passage, and furthermore, there are problems in that fluid sealing work and maintenance are difficult.

0003

OBJECTS OF THE INVENTION It is an object of the present invention to provide a high-pressure valve that is simple in structure, compact, and maintenance-free and that can be opened and closed with a small pilot pressure.

0004

[Summary of the Invention] The present invention was completed based on the idea of providing a mechanical boosting mechanism using a boosting lever between a piston and a slider that transmits the movement of the piston to a valve body. . The high-pressure valve of the present invention includes a piston that is movably fitted into a cylinder and moves by air pilot pressure, a valve body that opens and closes a fluid passage, a slider located between the piston and the valve body, and a slider that is located between the piston and the valve body. and a biasing means for biasing the slider to move in the direction of opening or closing the fluid passage, and converting the linear movement of the piston, which is moved by the air pilot pressure against the biasing means, into a swinging motion of the boost lever. The present invention is characterized in that it includes a mechanical boosting mechanism that mechanically boosts the movement of the piston by the swinging movement of the boosting lever and transmits the boosted force to the slider.

This mechanical boosting mechanism includes, for example, a boosting lever having one end pivoted to a fixed part of a cylinder and the other free end abutting a piston, and a boosting lever provided near the pivoting part of the boosting lever. In addition, it may include a cam mechanism that boosts and transmits the swinging motion of the boost lever to the slider. In its simplest form, this cam mechanism consists of a cam surface formed by changing the diameter around the lever's pivot point on the boost lever itself, and a follower provided on the slider side that contacts this cam surface. It can be composed of.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to illustrated embodiments. 1 and 2 show the present invention in a normally closed (N.C., Normal) state.
An example in which the present invention is applied to a high-pressure valve of the ly Close) type will be shown. The valve body 11 is formed with a fluid inlet passage 12 , an outlet passage 13 , and a connecting passage 14 connecting the inlet passage 12 and the outlet passage 13 . The upper end of the connection flow path 14 in FIG. This valve body 16 is biased in the valve opening direction by a weak compression spring 17. The upper end of the valve body 16 in FIG. 1 is in contact with the metal diaphragm 18. The metal diaphragm 18 closes a valve chamber 19 that communicates with the inlet passage 12, the outlet passage 13, and the connecting passage 14.

A cylinder 22 is fixed onto the valve body 11 via a connector 21 in the axial direction of the valve body 16. A piston 23 and a slider 24 are fitted into the cylinder 22 so as to be movable coaxially and independently of each other. That is, the piston 23 located at the upper part of the cylinder 22 has a guide rod 25 coaxially therewith, and the shaft hole formed in the slider 24 is slidably fitted into the guide rod 25. The upper end of the cylinder 22 is closed by a lid 26, and an air pilot chamber 27 is formed between the lid 26 and the piston 23. The lid body 26 is provided with an air pilot pressure introduction hole 28 .

A spring seat plate 30 is also provided inside the cylinder 22, and a laminated layer is provided between the spring seat plate 30 and the flange 31 of the slider 24 to bias the slider 24 toward the valve body 16. A disc spring 32 is inserted. The laminated disc spring 32 is strong enough to close off high pressure fluid;
Much stronger than compression spring 17. Therefore, the lower end of the slider 24 contacts the upper end of the valve body 16 with the metal diaphragm 18 in between, and presses the valve body 16 in the valve closing direction. In other words, valve body 1
6 is normally seated on the valve seat 15 and closes the fluid passage.

Between the piston 23 and the guide rod 25,
A mechanical boost mechanism using a boost lever 33 is provided. A pair of boost levers 33 are provided symmetrically with respect to the axial center of the guide rod 25. This boost lever 33 has a shape that avoids the guide rod 25 and slider 24 in order to make its length as long as possible within the space of the cylinder 22, and one end (the lower end in FIG. 1) is connected to the cylinder 22.
A roller 35 is provided at the other end (the same end) to contact the lower surface of the piston 23 . The boost lever 33 is formed with a cam surface 36 that changes its diameter (distance) around the fixed shaft 34.

On the other hand, the slider 24 has a follower 38 at the tip of its pair of radial arms 37, which abuts the cam surface 36 from above. The cam surface 36 has a shape that gradually increases the distances s(1) and s(2) from the fixed shaft 34 when the boost lever 33 swings downward around the fixed shaft 34 from the state shown in FIG. are doing.

The present high pressure valve having the above structure operates as follows. When the air pilot pressure P is supplied to the chamber 27 from the introduction hole 28, the piston 23 descends. When the piston 23 descends, the boost lever 33 is pushed by the lower surface of the piston 23 and swings around the fixed shaft 34, causing the cam surface 36 to move toward the follower 38,
In other words, push up the slider 24. This push-up force is boosted by the lever ratio of the boost lever 33 determined by (distance between the shaft 34 and roller 35/distance s of the cam surface 36 from the shaft 34), and therefore, the force exerted on the piston 23 is small. The descending force allows the slider 24 to be raised with a large force that resists the laminated disc spring 32. When the slider 24 rises, the fluid pressure in the connecting channel 14 and the compression spring 1
The force 7 causes the valve body 16 to separate from the valve seat 15, opening the fluid passage. When the supply of air pilot pressure to the air pilot chamber 27 is stopped and atmospheric pressure is introduced, the valve body 16 is seated on the valve seat 15 by the force of the laminated disc spring 32, and the flow path is closed.

The stroke given to the valve body 16 to open the flow path is usually around 1 mm, and therefore the amount of change in the diameter (distance) s of the cam surface 36 may be set accordingly. This means that the lever ratio can be easily made sufficiently large.

FIGS. 3 to 7 illustrate the present invention in a normally open (N.O.
．． , Normally Open) type high-pressure valve, and common components with the normally closed first embodiment shown in FIGS. 1 and 2 are given the same reference numerals. The main points that this embodiment differs from the first embodiment are: (1) slider 24A;
is biased in the direction of opening the valve body 16 by a compression spring 41 inserted between its own flange 40 and the connector 21; (2) a fulcrum support plate 42 is provided within the cylinder 22; A pair of boost levers 3 are attached to this fulcrum support plate 42.
3A fixed shaft 34A is provided; 1. The cam surface 36A formed on the boost lever 33A contacts the follower 38A of the slider 24 from above; 2. The piston 23.
A has a rolling diaphragm 43, and (2) the air pilot pressure introduction hole 28A is formed directly in the cylinder 22.

According to this embodiment, when the piston 23A is lowered by applying the air pilot pressure P to the chamber 27A, the booster lever 33A swings about the fixed shaft 34A, and as a result, the cam surface 36A The follower 38A is pressed and the slider 24A descends. This descending force is boosted by the lever ratio of the boost lever 33A, so
Even if the force applied to the piston 23 is small, it can be made strong enough to overcome the compression spring 41, and therefore the valve body 1
6 can be seated on the valve seat 15 to close the fluid passage. When the supply of air pilot pressure to the air pilot chamber 27A is cut off, the force of the compression spring 41 and the compression spring 17 causes the valve body 16 to separate from the valve seat 15, opening the flow path.

[0015]

Effects of the Invention: The high-pressure valve of the present invention converts the movement of a piston moved by air pilot pressure into the rocking motion of a boost lever, and mechanically doubles the movement of the piston by the rocking motion of the boost lever. Since the force is transmitted to the slider and moves the valve body in the valve opening direction or valve closing direction, the high pressure valve can be opened and closed with a small pilot pressure. In particular, a mechanical boosting mechanism using a boosting lever has a simple structure and can be miniaturized, and does not require liquid filling work or maintenance unlike a liquid booster, so costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view taken along line BB in FIG. 2, showing an embodiment in which the present invention is applied to a normally closed high-pressure valve.

FIG. 2 is a sectional view taken along line AA in FIG. 1;

FIG. 3 is a cross-sectional view taken along line E-E in FIG. 4, showing an embodiment in which the present invention is applied to a normally open type high-pressure valve.

FIG. 4 is a sectional view taken along line CC in FIG. 3;

FIG. 5 is a sectional view taken along line DD in FIG. 3;

6 is a plan view of the booster arm of the high pressure valve of FIG. 3; FIG.

7 is a plan view of the fulcrum support plate of the high pressure valve of FIG. 3; FIG.

[Explanation of symbols]

11 Valve body 12 Entrance passage 13 Exit passage 14 Connection flow path 15 Valve seat 16 Valve body 17 Compression spring 18 Metal diaphragm 22 Cylinder 23 23A Piston 24 24A Slider 27 Air pilot room 32 Laminated disk spring 33 33A Boost lever 34 34A Fixed axis 35 35A Roller 36 36A Cam surface 38 38A Follower 41 Compression spring

Claims (3)

[Claims] Claim 1: A piston movably fitted in a cylinder and moved by air pilot pressure; A valve body that opens and closes a fluid passage; A slider located between the piston and the valve body; The valve body and slider are connected to a fluid passageway. A biasing means for biasing movement in the opening or closing direction; and converting the linear movement of the piston, which moves by the air pilot pressure against the biasing means, into a swinging motion of the booster lever, and A high-pressure valve characterized by being equipped with a mechanical boosting mechanism that mechanically boosts the movement of a piston and transmits it to a slider. 2. In claim 1, the mechanical boosting mechanism comprises a boosting lever having one end pivoted to a fixed portion of the cylinder and the other free end abutting the piston, and a pivoting portion of the boosting lever. A high-pressure valve comprising a cam mechanism provided nearby that boosts and transmits the swinging motion of the boost lever to a slider. 3. In claim 2, the cam mechanism includes a cam surface formed on the booster lever itself by changing a diameter around the pivot portion of the lever, and a slider side in contact with the cam surface. A high pressure valve consisting of a follower and a follower.