JPS5817910B2 - Disc spring control valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control valve using a disc spring that can instantaneously shut off fluid such as gas or liquid.

This type of control valve is used, for example, as an exhaust gas purification device for automobiles, particularly as a vacuum control valve.

FIG. 1 shows a control valve 40 using a conventional disc spring disclosed in Japanese Patent Application Laid-Open No. 46-685.
An example is shown in which a valve body A is interposed between an upper case 50 and a lower case 51, and this valve body A has a boss 5 in the center.
It consists of a membrane plate 53 with a protruding number 2 and a disc spring 54.

The non-internal space defined by the upper case 50 and the lower case 51 is divided by the valve body A into upper and lower chambers 55 and 56 in FIG.

The upper case 50 has a passage 57 as a control input/output port for introducing fluid into the chamber 55, and the lower case 51 has a passage 58 as a second input/output port for introducing fluid into the chamber 56, and a passage 57 as a control input/output port for introducing fluid into the chamber 56. A passage 59 serving as a first input/output port for discharging the water is provided.

In the control valve 40 shown in FIG. 1, the passage 59 is normally closed by the boss 52, and the passage 56
When fluid is introduced into the chambers 55 and 58 and the pressure difference between the pressure in the chamber 55 and the pressure in the chamber 56 reaches P, (valve opening start pressure difference), the valve body A starts to drive 7, and then the pressure difference increases. When P2 (reversal pressure difference: Pl<P2) is reached, the valve body A is completely reversed, the passage 59 is opened, and the fluid introduced from the passage 58 into the chamber 56 is guided from the passage 59 to the outside of the valve.

The fluid starts to be discharged and the pressure difference is P, (restored pressure difference: Pl>
P, ), the valve body A is reversed to its original state and the passage 5
9 is closed by boss 52, and thus fluid from passage 58 is shut off by valve 40.

In such a conventional control valve, the dimensions of each part of the upper case 50 and the lower case 51 are fixed to preset values, and the boss 52 of the valve body A and the valve seat 59A formed in the passage 59. In other words, the height of the valve seat 59A cannot be adjusted.

Therefore, 1. When used in various locations where the desired valve opening starting pressure difference is different, 2. When adjusting the valve opening starting pressure difference due to manufacturing variations in disc springs, 3. If it changes over time, make additional work on the case or adjust the height of the valve seat by adjusting the shims so that the flow rate characteristics of the control valve rise at the desired opening pressure difference. The adjustment was complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a control valve using a disc spring that can easily adjust the valve opening start pressure difference by making the height of the valve seat adjustable.

The present invention is characterized by comprising a pipe which is screwed into the valve case and whose tip protrudes into the valve chamber to serve as a first input/output port. Because there is.

By changing the amount of threading of the pipe, the height of the valve seat can be adjusted, and the pressure difference at which the valve opens can be easily adjusted.

In order to solve the technical problem of the present invention, the height of the valve seat may be adjustable by connecting it with a pipe joint, but in contrast, according to the present invention, the valve seat height can be adjusted by connecting the valve seat with a pipe joint. Since there is no need for pipe fittings to connect the valve seat parts, the number of parts is reduced, and compared to valve cases that can be disassembled and reassembled for maintenance and modification purposes, the pipes are attached to the valve case. The pipes are screwed together and are removable, so (1) the inside of the pipe can be cleaned without removing the pipe, (2) only the pipe can be replaced if the pipe is damaged, and (3) the pipe can be replaced. Pipes bent in various directions can be installed depending on the direction of the pipe, which has the effect of making piping work easier.

Embodiments of a control valve using a disc spring according to the present invention will be described below with reference to the drawings.

In FIGS. 2 and 3, the control valve 1 has a valve body A and a hollow valve case 2, and the valve body A is a thin plate-shaped disc as shown in FIGS. 4 and 5. It consists of a spring 20 and a seal member 22A made of, for example, rubber, which is attached to a circular hole 21 formed in the center of the disc spring 20 and closes the circular hole 21.

Here, the load-displacement characteristics of the disc spring 20 are
For example, the compressibility-compressive stress characteristics of the sealing member 22A may be set as the characteristics shown in FIG.
It can be configured as a custom order as shown in the figure.

In FIG. 6, the disc spring 20 is displaced from point a to an inflection point according to the load, and from the inflection point it is instantaneously displaced to point C, that is, reversed.
In the figure, the load Fo required for displacement from point a to the inflection point is shown as Fo, and the amount of displacement from point a to the inflection point is shown as Lomax.

The valve case 2 consists of valve chamber cases 2A and 2B, and the peripheral edge of the valve body A is supported on the inner walls of the fixed portions of these cases 2A and 2B via a seal member 22B.

This valve body A allows the valve case 2 to have valve chambers 7 and 8.
is defined, and the valve body A has a convex shape toward the valve chamber 8 at its central portion.

A pipe 13 is screwed coaxially with the valve body A in the center of the valve chamber case 2B forming the valve chamber 8, and the tip end 14 of the pipe 13 protrudes into the valve chamber 8 and connects to the first part of the valve. It serves as an input/output port, and is normally closed by the elastic force of the valve body A.

Further, a second input/output port 15 is formed in the valve chamber case 2B near its outer peripheral end.

On the other hand, a control input/output port 10 is formed coaxially with the valve body A in the two valve chamber furnaces, through which a fluid controlling the pressure in the valve chamber 7 can be introduced.

In the control valve 1 configured in this way, the height of the valve seat is adjusted by screwing in the pipe 13, thereby pushing the valve body A in its reverse direction and displacing the disc spring 20 and the seal member 22A, respectively. Therefore, the valve opening start pressure difference, in other words, the rising point of the flow rate characteristics can be set arbitrarily.The screwing amount of the pipe 13, the displacement amount of the disc spring 20 and the seal member 22A, and the following are as follows. Let us explain about flow rate customization.

Here, the amount of displacement of the seal member 22A when the pipe 13 is pushed toward the seal member 22A can be approximately determined as follows.

As shown in FIG. 8, the effective thickness of the seal member 22A is 4
1 The outer diameter of the pipe 13 is Dp, the inner diameter is Dp2, the pipe 13
The load that the sealing member 22A receives from FpN is the load F
If the amount of displacement of the seal member 22A in the pipe axis direction due to p is ε, then the compressive stress σp generated in the seal member 22A at that time can be expressed approximately.

If the seal member 22A is made of rubber having a compressibility-compressive stress characteristic relationship as shown in FIG. 7, the displacement ε of the seal member 22A is approximately as follows: A value of 1 in the shape factor σ0: can be expressed as the compressive stress of the seal member 22A when the seal member 22A is compressed by λ% of the effective thickness l.

On the other hand, the displacement of the disc spring 20 when a load Fp is applied to the seal member 22A can be determined from the load-displacement characteristic of the disc spring set in advance as shown in FIG.

Then, the pipe 13 is pushed in, and its tip 1
4 makes contact with the seal member 22Ay and the fluid is cut off as a reference point, and from that point, the pipe 13 is further pushed in, and the displacement of the seal member 22A at a certain pushing amount Di is determined by If the amount of displacement is Li, D is independent of the compressibility-compressive stress characteristics of the seal member 22A, the load-displacement characteristics of the disc spring 20, etc.
i2εi+Li' (3) Here,
εi>O and Li>”0 hold true.

Next, the pushing amount Di of the pipe 13 and the control valve 1
The flow rate characteristics, especially the rise characteristics, will be explained.

Now, assume that the load (pushing amount)-displacement customization of the disc spring 20 and the seal member 22A are shown by curves X and Y in FIG. 9, respectively.

In FIG. 9, when the pipe pushing amount is the maximum value Dmax, the valve body A is pressed with a load Fmax, and at that time, the disc spring 20 is displaced to Lmax, that is, just before the inflection point, and the sealing member 22A is moved by εmax. It is assumed to be displaced.

In addition, in FIG. 9, the displacement amount Lmax of the disc spring 20 is the displacement amount up to the inflection point shown in FIG. 6.

This value is slightly smaller than the load Fmax, and the load Fmax is also a slightly smaller value than the load Fo required to displace the force to the inflection point.

Here, the maximum value Dmax of the pushing amount is D max = e max + L max
(4).

Therefore, if the pipe 13 is pushed in from the reference point by the maximum value Dmax, the negative pressure introduced into the valve chamber 7 through the control input/output port 10 causes the disc spring 20 to become slightly smaller than the negative pressure corresponding to Fmax. When receiving a large negative pressure P3, the disc spring 20 instantaneously reverses beyond the inflection point, and therefore, as shown in FIG. becomes the maximum flow rate Qmax (Fig. 10 a-+b) from zero at once. Next, calculate the pipe pushing amount, (0<Dl<Dmax)
Then, the valve body A will be pressed by the load F1,
From FIG. 9, the disc spring 20 is displaced by Ll,
The seal member 22A is displaced by ε1.

Here, considering when the seal member 22A separates from the input/output port 14 and the flow rate rises, the negative pressure in the valve chamber 7 becomes negative pressure P2 which is greater than the negative pressure P1 corresponding to the load F1, and the disc spring 20 When the seal member 22A is displaced by the displacement amount ε4, the seal member 22A separates from the input/output port 14 and the flow rate starts to rise.

In other words, the negative pressure P2 is a negative pressure corresponding to the load F2 in FIG. 9, and when the negative pressure in the valve chamber 7 reaches P2, the seal member 22A starts to separate from the input/output port 14.
Outflow begins to rise from the negative pressure P2 (Fig. 10C),
After that, a flow rate characteristic that almost matches the displacement characteristic of the disk spring 20 is obtained, and when the negative pressure in the valve chamber 7 reaches P3, the disk spring 20 instantaneously reverses, so that the flow rate increases at once to the maximum flow rate Qmax.

When the pipe 13 is located at the reference point, that is, when the pushing amount is Di=O, as the negative pressure gradually increases, the displacement amount of the disc spring 20 also increases accordingly, so that the pipe 14 and the sealing member The distance to 22A gradually increases depending on the negative pressure.

Therefore, in this case, flow characteristics that substantially match the displacement characteristics of the disc spring 20 can be obtained.

(Fig. 10 e-+l)). Next, seal member 22A
Assuming that is a resin or hard rubber, for example in FIG. 9, if the load-displacement characteristic of the seal member 22A is set so that the displacement of the seal member 22A becomes almost zero even when a load Fmax is applied to the valve body A, then (3) The equation can be expressed as Di20+Li (3)', and a control valve in which the pushing amount Di of the pipe 13 and the displacement L1 of the disc spring 20 are approximately equal can be obtained.

In this case as well, the flow rate characteristics are similar to those explained in FIG.
(= L max ), the flow rate goes from zero to the maximum at once at the negative pressure P (Fig. 10 a-+l)), and when the pushing amount is 0 < Di < D max, the negative pressure reaches P2. Then, the input/output port 14 begins to open (Fig. 10C), and after the flow rate increases to point d under negative pressure P3, the disc spring 20 instantly reverses, and a custom flow rate can be obtained in which the flow rate becomes maximum at once. .

Furthermore, when Di is 20, the disc spring 20 is displaced in a custom-made manner as shown in FIG. 9 in response to an increase in negative pressure, so that a custom-made flow rate such as e-+b in FIG. 10 can be obtained.

On the other hand, by using relatively soft rubber as the sealing member 22A, for example in FIG. 9, the load-displacement of the disc spring 20 is adjusted so that even if a load Fmax is applied to the valve body A, the displacement of the disc spring 20 becomes almost zero. After setting the characteristics, equation (3) becomes Di−εi 〇
(3) It is possible to obtain a control valve in which the pushing amount Di of the pipe 13 and the displacement amount εi of the seal member 22A are approximately equal.

In this case as well, as explained above, the pushing amount D of the pipe 13
Depending on i, if Di = D max then point a-+b in Figure 10, if O<Di <Dmax7a' then point C→a-+b, if Di = 0 then point 6-+l)
Various flow rates can be custom made, such as:

In the control valve 1 configured in this way,
A desired valve seat height is obtained by the pipe 13, which makes it possible to push the valve body A in its reverse direction, and the compressibility of the seal member 22A - the displacement of the seal member 22A against a load such as compressive stress custom made etc. By adjusting the pushing amount of the pipe 13 according to the amount and the load-displacement characteristics of the disc spring 20, various flow characteristics can be set such that the flow rate rises at an arbitrary valve opening start pressure difference.

[Brief explanation of drawings]

Figure 1 is a sectional view showing a conventional control valve, Figure 2 is a sectional view showing a conventional control valve.
3 and 3 are cross-sectional views showing an embodiment of the control valve according to the present invention, FIGS. 4 and 5 are front views and side sectional views showing the valve body A, and FIG. 6 is a load on the disc spring 20. - Displacement characteristic curve diagram, Fig. 7 is a compression ratio-compressive stress custom curve diagram of the seal member 22A, Fig. 8 is a detailed diagram showing the contact state between the pipe 13 and the seal member 22A, and Fig. 9 is a disc spring 20 and a load (pipe pushing amount)-displacement characteristic curve diagram of the sealing member 22A, and FIG. 10 is a graph showing the flow rate %a of the control valve when the disc spring 20 and the sealing member 22A having the characteristics shown in FIG. 9 are used. be. 1... Control valve, 2... Valve case, 2A12B... Valve case, 1
0,14゜15... Input/output boat, A...
... Valve body, 20 ... Disc spring, 22
A... Seal member.

Claims (1)

[Claims] 1. A hollow valve case, and a disk spring having a sealing member approximately in the center and whose peripheral edge is supported within the valve case to partition the inside of the valve case into a first valve chamber and a second valve chamber. , a control input/output port communicated with the first valve chamber through which a fluid controlling the pressure of the first valve chamber flows in and out; and a control input/output port communicated with the second valve chamber and opened and closed by the seal member. a first input/output port and a second input/output port communicated with the second valve chamber, the disc spring is moved together with the seal member according to the pressure in the first valve chamber; The disc spring is reversed and the first
In the control valve using a disc spring, the disc spring is configured to open a fluid passage between an input/output port and a second input/output port, and the disc spring is screwed into the valve case, and its tip protrudes into the valve chamber. A control valve using a disc spring characterized by having a pipe serving as an input/output port.