JPH0337673B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a stop valve used to shut off fluid flow, and the present invention relates to a stop valve used to shut off the flow of fluid. This technology eliminates fluid leakage due to deformation of the seat or valve surface.

<Prior art> In general, the basic structure of a stop valve is that by tightening and rotating the handle, a propelling screw member is screwed against the valve body, and the thrust moves the valve body toward the valve closing side, thereby closing the valve. The face is configured to bring the valve seat into closing abutment.

In the conventional example, for example,
As described in the publication, the propelling screw member presses the valve body, which is biased toward the valve opening side by the valve opening spring, toward the valve closing side via the diaphragm.

<Problems to be Solved by the Invention> By the way, the stop valve of the above-mentioned conventional configuration has the following inconveniences when shutting off fluid.

B. The resistance force when tightening the handle when closing the valve changes as shown by curve X in Figure 2.

That is, the resistance force is at position A where the valve surface is fully open.
During the movement from the position B to the position B where it contacts the valve seat, the valve opening spring and the diaphragm are deformed by the deformation force, and the valve rises at a small value and at a gentle angle. After passing the valve seat abutting position B, the deforming force of the valve surface is also applied, and the valve rapidly moves upward, and then rises linearly at a steep angle.

In this case, the appropriate closing abutment force P of the valve surface is in the middle of a steep linear rise region. For this reason, when the operator turns the handle while feeling the handle, he or she cannot accurately sense whether the appropriate closing contact force P has been reached.

As a result, people often overtighten the valve for fear of leakage if it is not tightened enough, and the closing contact force on the valve surface becomes abnormally large.
The valve seat or valve surface is damaged prematurely.

(b) When the valve is closed, the propulsion screw member may begin to loosen due to vibration.

If it starts to loosen even a little, the valve body is biased toward the valve opening side by the reaction force from the valve seat, so the closing contact force on the valve face rapidly weakens, and as a result, the propulsion screw member The frictional fixing force also rapidly weakens, making it easier for the fluid to loosen and for fluid to leak.

C. While the valve is in the closed state, plastic deformation of the valve seat or valve surface progresses over time, albeit slowly, due to the closing contact force. This plastic deformation is
When the valve seat or the valve surface is made of a synthetic resin material, and when the valve closing period is longer, the amount of deformation becomes larger, and therefore the closing contact force of the valve surface decreases. When the plastic deformation progresses beyond a certain amount, the closing contact force of the valve surface becomes lower than the appropriate value, and fluid leakage occurs.

The present invention aims to make it possible to feel this as a response when the valve surface reaches an appropriate closing contact force during the valve closing operation, and to enable the propulsion screw member to receive vibrations while the valve is closed. The purpose is to prevent the valve from loosening, and to prevent the closing contact force from decreasing even if the valve seat or valve face undergoes plastic deformation due to the closing contact force while the valve is closed. do.

<Means for Solving the Problems> In order to achieve the above object, the present invention, in the above basic structure, closes and connects the valve face 14 to the valve seat 7a with an appropriate force, for example as shown in FIG. A valve closing thrust transmission system T extending from the propulsion screw member 3 to the valve body 12 is provided with a spring S for imparting an appropriate valve closing force.

<Function> The function of the above structure will be explained by exemplifying a stop valve provided with a metal diaphragm, as shown in FIGS. 1 and 2, for example.

The solid line in FIG. 1 shows the stop valve 1 in an open state. When the stop valve 1 is closed, the valve box 2
When the handle 4 is rotated so that the propulsion screw member 3 spirals downward, the lower end of the valve stem 26 first comes into contact with the diaphragm 17 (as shown by the two-dot chain line in the figure). Further, as you tighten the handle 4,
The valve body 12 is moved toward the valve seat 7a against the deformation resistance of the diaphragm 17 and the biasing force of the valve opening spring 16, and the valve surface 14 of the valve body 12 is brought into contact with the valve seat 7a (see FIG. (Illustrated with chain double-dashed line). When the handle 4 is further operated in this state, the valve surface 14 begins to be elastically deformed. When the deformation resistance of the valve surface 14 reaches a predetermined value or more, compression of the spring S for applying appropriate valve closing force is started. When this compression is completed, only elastic deformation of the valve surface 14 is allowed.

During the valve closing operation, the resistance force when the handle 4 is tightened changes as shown by a curve Y in FIG. 2.

That is, from position A where the valve surface is fully open to position C where compression of the appropriate valve closing force imparting spring S starts, the curve Y changes in the same way as the curve X of the conventional example. This curve Y rises at a gentle angle after exceeding the above-mentioned position C, and then rises in a straight line at a steep angle when it exceeds the position D where compression of the spring S for applying proper valve closing force is completed. going up.

<Example> Hereinafter, an example of the present invention will be described with reference to the drawings.

(First Embodiment) FIGS. 1 and 2 show a first embodiment. In Fig. 1, numeral 1 is an angle-type stop valve.
Reference numeral 2 is the valve box. A propulsion screw member 3 is provided which is screwed into this valve box 2, and this propulsion screw member 3
A handle 4 for operation is attached to the upper end.

The valve box 2 has a valve box main body 5 extending in the vertical direction.
and a lid member 6 that covers the upper opening of the valve box body 5. A cylindrical valve chamber 7 whose axis is vertically oriented is provided in the middle of the valve box body 5 in the vertical direction. The terminal end of the inlet hole 9 is opened in the center of the bottom wall of the valve chamber 7, and a valve seat 7a is formed along the edge of the opening. Further, the starting end of the outlet hole 10 is opened in the lower part of the peripheral wall of the valve chamber 7.

A cylindrical valve body 12 is fitted into the valve chamber 7 so as to be able to slide up and down, and an elastic disk 1 formed in an annular shape from fluororesin or the like is provided at the bottom of the valve body 12.
3 is fitted. A valve surface 14 is constituted by the lower surface of the disk 13, and this valve surface 14
can be pressed against the valve seat 7a via a valve-closing thrust transmission system T installed inside the valve box 2.

This valve-closing thrust transmission system T will be explained below.

A valve opening spring 16 is installed between the lower side of the valve chamber 7 and the upper part of the valve body 12, and the valve body 12 is urged in a direction away from the valve seat 7a via the valve opening spring 16. The valve chamber 7 is in contact with the upper surface of this valve body 12 and
A disk-shaped metal diaphragm 1 that airtightly partitions the
7 is provided. An annular projection 5a that supports this diaphragm 17 is formed on the valve box body 5, and the diaphragm 17 is pressed and fixed to this projection 5a via a forwardly raised lid member 6.

The lid member 6 includes a pressing ring 19 placed on the diaphragm 17, and a presser cylinder 20 that fits around the pressing ring 19 and presses it toward the diaphragm 17.
and a lid bolt 21 that fits onto the presser tube 20 and presses it toward the diaphragm 17. This lid bolt 21 is screwed into the upper inner circumferential surface of the valve box main body 5.

On the inner peripheral side of the presser cylinder 20 in the lid member 6,
The outer peripheral side of the propelling screw member 3 is screwed together, and the handle 4 is fitted into the upper end of the propelling screw member 3 so as to be relatively unrotatable. Further, a valve rod 26 which is an intermediate transmission member is inserted coaxially into the propulsion screw member 3, and the upper end of the valve rod 26 is supported by the upper end of the propulsion screw member 3 via a nut 28.

Further, a head portion 26a is formed at the lower part of the valve stem 26, and a pressing piece 22 is provided on the lower surface side of the head portion 26a.
9 is attached. The pressing piece 29 allows the radially central portion of the diaphragm 17 to be pressed downward.

An annular spring chamber 31 extending in the vertical direction is formed between the propulsion screw member 3 and the valve stem 26. Within this spring chamber 31, a plurality of disc springs 32 constituting the spring S for applying appropriate valve closing force are installed. It will be installed. This disc spring 3
2 urges the valve stem 26 downward with respect to the propelling screw member 3.

In the above configuration, when the valve is closed, when the handle 4 is rotated so that the propulsion screw member 3 spirals downward with respect to the valve box 2, the thrust force causes the propulsion screw member 3 to move through the disc spring 32, the valve stem 26, and the diaphragm 17. The valve body 12 is moved to the valve closing side, and the valve surface 14 is brought into contact with the valve seat 7a (as shown by the chain double-dashed line in FIG. 1). and,
When the handle 4 is further tightened and rotated, the disk 1
3 and the disc spring 32 are compressed, and the valve surface 14
is tightened to the valve seat 7a, thereby causing the valve seat 7
a is closed. Curve Y in Figure 2 is the handle 4
It shows the resistance force when tightening.

On the other hand, when opening the valve, contrary to the above, the valve box 2
When the handle 4 is rotated so that the propelling screw member 3 spirals upward, the valve body 12 is moved upward by the biasing force of the valve opening spring 16, and the valve seat 7
a is opened (shown by solid lines in FIG. 1).

FIG. 3 to FIG. 6 show other embodiments, and explanations will be given of configurations different from the first embodiment.

(Second Embodiment) FIGS. 3 and 4 show a second embodiment. In FIG. 3, reference numeral 36 denotes a presser cover formed in the shape of a cap nut, and the presser cover 36 and the press ring 19 constitute the cover member 6. That is, a press ring 19 that presses the diaphragm 17 against the protrusion 5a is fitted into the upper part of the valve box body 5, and the press ring 19 is held by the presser cover 36 screwed onto the upper outer periphery of the valve box body 5. It is pushed downward. This presser foot lid 3
The propulsion screw member 3 is screwed into the screw 6.

FIG. 4 shows a partial modification of this second embodiment. In this case, an O-ring 37 is provided in place of the diaphragm that partitions the valve chamber 7 in an airtight manner. That is, a circumferential groove 38 is formed in the upper part of the valve body 12, and an O-ring 37 is installed between the circumferential groove 38 and the circumferential wall of the valve chamber 7.

(Third Embodiment) FIG. 5 shows a third embodiment. in this case,
The diaphragm 17 is pressed against the projection 5a by the lower end of the lid bolt 21 screwed into the upper part of the valve body body 5. A propelling screw member 3 is screwed onto the lid bolt 21, and a pressing piece 29 is attached to the lower end of the propelling screw member 3.

On the other hand, a cylindrical spring chamber 31 that is open at the top is formed within the valve body 12 . This spring chamber 31
A plurality of disc springs 32 are mounted in the vertical direction, and a spring presser 41 that presses the disc springs 32 downward is fitted into the spring chamber 31. Above spring holder 4
The protruding end of 1 passes through the cover plate 42 and the diaphragm 1
It is in contact with the lower surface side of 7.

Then, the diaphragm 17 is
When moved downward, the spring presser 41 is pressed by the diaphragm 17, and the disc spring 32 is made compressible.

(Fourth Embodiment) FIG. 6 shows a fourth embodiment. in this case,
A propulsion screw member 3 is screwed into the valve body body 5, and the protruding end of the head portion 26a of the valve stem 26 is engaged with the upper portion of the propulsion screw member 3.

Further, a valve body 12 is fitted into the lower part of the propelling screw member 3 so as to be slidable up and down. Reference numeral 13 is a disk. A spring chamber 31 is formed between the propulsion screw member 3 and the valve body 12, and in this spring chamber 31, a pair of disc springs 32 constituting a spring S for applying an appropriate valve closing force is provided.
is installed.

Note that the reference numeral 45 is an O-ring and the reference numeral 46 is a gasket.

<Effects of the Invention> Since the present invention is configured and operates as described above, it has the following effects.

B. The resistance force when the handle is tightened during the valve closing operation changes, for example, as shown by the curve Y in FIG. 2.

That is, the resistance increases at a gentle angle from position C where compression of the appropriate valve closing force imparting spring starts to position D where compression is completed.
Beyond position D, it rises at a steep angle. Then, as the operator turns the handle, the resistance suddenly increases at the above-mentioned position D, so that the operator can feel that the valve surface has reached the appropriate closing contact force P.

(b) Even if the stop valve is subjected to vibrations during the valve closing state, the propulsion screw member can be firmly friction-fixed to the valve box side by the elastic repulsive force of the appropriate valve closing force imparting spring. Therefore, the propulsion screw member is prevented from loosening, and fluid leakage is prevented.

C. Even if the valve seat or valve face undergoes plastic deformation due to the closing contact force during the valve closing state, the elastic repulsion force of the spring that provides appropriate valve closing force will follow the amount of plastic deformation. The valve surface can be pressed toward the valve closing side. Therefore, the closing contact force of the valve surface is prevented from becoming lower than an appropriate value, and as a result, fluid leakage is more reliably prevented.

D. The spring for providing proper valve closing force made of a disc spring can secure a large energy density, so it can be compact while ensuring a strong elastic force, and the stop valve can be made compact.

In addition, the spring characteristics of disc springs can be easily changed by changing the number of layers or changing the direction of the layers, so spring mounting parts can be used commonly for stop valves of different models with different closing forces. can reduce production costs.

(e) Since the valve chamber can be sealed with a metal diaphragm that is a fixed sealing member, fluid leakage from the valve box can be prevented and it can be used for high pressure applications.

F. Since the appropriate valve closing force imparting spring is installed in the external space of the valve chamber, it is not affected by the volume of the valve chamber and can be used even in small valves.

G. Since the above spring is installed in the external space of the valve chamber and is prevented from coming into contact with the fluid used, good spring performance can be maintained for a long period of time.

H. Since the expansion and contraction stroke of multiple disc springs can be added to the short opening/closing lift of the metal diaphragm, the rotation angle of the handle can be increased by that stroke. As a result, the operating angle of the handle can be made closer to that of a non-diaphragm type stop valve, so that the operator does not have to feel uncomfortable.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, and Figures 1 and 2 are the first embodiment. Figure 1 is a longitudinal sectional view of the stop valve, and Figure 2 shows the resistance force when tightening the handle and the handle A diagram showing the relationship with the rotation angle, FIGS. 3 and 4 are the second embodiment, FIG. 3 is a diagram corresponding to FIG. 1, and FIG. 4 is a partial diagram showing a partial modification of FIG. 3. , FIG. 5 shows the third embodiment and corresponds to FIG. 1, and FIG. 6 shows the third embodiment.
The figure shows a fourth embodiment and corresponds to FIG. 1. 1... Stop valve, 2... Valve box, 3... Propulsion screw member, 4
...handle, 7a...valve seat, 12...valve body, 14...valve surface, 26...valve stem, 31...spring chamber, 32...disc spring,
S...appropriate valve closing force imparting spring, T...valve closing thrust transmission system.

Claims (1)

[Scope of Claims] 1. By tightening and rotating the handle 4 of the stop valve 1, the propelling screw member 3 is spirally advanced with respect to the valve box 2, and the thrust causes the valve inserted into the valve chamber 7 to In this stop valve, the valve body 12 is moved to the valve closing side and the valve surface 14 of the valve body 12 is brought into close contact with the valve seat 7a, in which the valve chamber 7 is hermetically divided by a metal diaphragm 17. At the same time, the valve opening spring 16
The propelling screw member 3 is placed on the opposite side of the valve chamber 7 across the diaphragm 17, and the intermediate transmission member 26 is applied to the propelling screw member 3.
is fitted inside the valve body 12 so as to be movable within a certain range in the opening/closing direction, and a plurality of disc springs 3 are disposed between these two members 3 and 26.
The intermediate transmission member 26 is pressed against the propulsion screw member 3 toward the diaphragm 17 by the elastic force of the spring S, and the handle 4 is tightened. The operating force is applied to the propulsion screw member 3.
From the appropriate valve closing force imparting spring S/intermediate transmission member 26/
A stop valve characterized in that the signal is transmitted to the valve body 12 via a diaphragm 17 in turn.