JPS6131404B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic opening/closing valve used to reduce the amount of air consumed by an air micrometer when not measuring.

Recently, energy saving measures have been taken in all fields, but with air micrometers, the amount of air consumed when not measuring is 2 to 3 times that when measuring.
N/min, and the energy loss is extremely large.
For this reason, shutoff valves have been devised to reduce air consumption during non-measurement periods. This kind of valve is
It is used by being attached to the measurement head, and is opened during measurement to release compressed air for measurement, and shut off when not measuring to stop the release of compressed air.
Even though air consumption can be reduced by this, the operability is not satisfactory, and the weight of the measuring head increases, resulting in a significant decrease in workability during measurement.

The present invention has been made in view of the above, and by connecting a valve that cuts off the flow of compressed air between the main body of the air micrometer and the measuring head, it is possible to avoid an increase in the weight of the measuring head and to reduce the weight of the measuring head. The valve is automatically opened and closed based on changes in the back pressure of the measurement head during measurement and non-measurement, which reduces wasteful air consumption and eliminates the complexity of operations during measurement. That is.

Next, the principle of the automatic opening/closing valve for an air micrometer of the present invention will be explained based on FIG. 1, which illustrates the characteristics of a general-purpose air micrometer.

In Figure 1, curve A ₀ shows the output characteristics of the air micrometer, curve B ₀ shows the non-measuring characteristics of the measuring head, and curves B ₁ and B ₂ show the measuring characteristics of the measuring head when measuring different objects. It is something. The intersection point C ₀ between the characteristic curves A ₀ and B ₀ is the operating point in the non-measurement state, and the intersection points D 0 and _{E 0 between} the characteristic curve A ₀ and the characteristic curves B ₁ and B ₂ are the operating points in different measurement states. Note that the characteristic curves B ₁ and B ₂ show differences based on the width of the measurement tolerance, and therefore the characteristic curves for individual different objects to be measured fall approximately within the range surrounded by the above-mentioned curves B ₁ and B ₂ .

The principle of the present invention is that an air micrometer can be operated by installing an automatic opening/closing valve between the air micrometer body and the measuring head, which automatically opens and closes in response to increases and decreases in the back pressure of the measuring head. By modifying the output characteristic of the air micrometer when not measuring, change the output characteristic curve of the air micrometer from A ₀ to A ₂ , thereby moving the operating point from the intersection C ₀ to the intersection C ₁ . In addition to greatly reducing air consumption, the change in the output characteristic curve of the air micrometer during measurement, which is inevitable when installing the automatic on-off valve mentioned above, is reduced to a minute value, such as from curve A ₀ to curve A ₁ , making it possible to measure Move the operating point from the intersection D ₀ to the intersection D ₁ or from the intersection E ₀ to the intersection E ₁
The aim is to limit the changes to minute changes that have little effect on the measurements.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. In FIG. is the inlet 2 that lets compressed air flow in from the air micrometer body.
and an outlet 3 for supplying the compressed air to the measuring head. The inlet 2 and outlet 3 are communicated with each other by a main channel that is automatically opened only during measurement and a sub-channel that is always open. The main flow path is constituted by an inlet side flow path 4 communicating with the inlet 2, a first pressure chamber 5, and an outlet side flow path 6 communicating with the outlet 3. Further, the sub-channel is a first branched from the inlet-side channel 4 and equipped with a variable supply throttle 8.
The variable supply throttle 8 is configured to communicate with the outlet side flow path 6 via the bypass flow path 7 and the first pressure chamber 5, and the variable supply throttle 8 is connected to a valve seat 8 formed in the first bypass flow path 7.
The opening amount of a can be adjusted by a needle portion 9a of an adjustment screw 9 screwed into the body 1 from the outside.

The first pressure chamber 5 is formed on one side of a diaphragm valve body 11 that opens and closes a first valve seat 4a formed in the inlet side flow path 4, and a diaphragm valve body 11 formed on the other side of the valve body 11. The second pressure chamber 12 has a second pressure chamber 12 equipped with a fixed throttle 14.
A first exhaust flow path 15 that communicates with the inlet side flow path 4 through a bypass flow path 13 and is equipped with a variable exhaust throttle 16 and a second exhaust flow path 1 that is equipped with a fixed throttle 18.
A second valve seat 15a, which is opened and closed by a diaphragm valve element 11, is formed at the inlet of the first exhaust flow path 15. The variable throttle 16 in the first exhaust flow path 15 adjusts the opening amount of a valve seat 15a provided in the first exhaust flow path 15 using a needle portion 19a of an adjustment screw 19 screwed into the body 1 from the outside. configured to be possible. With the above configuration, compressed air flows through the second bypass passage 1 having the inlet 2 and the fixed throttle 14.
3 into the second pressure chamber 12, while the compressed air flows out into the atmosphere through the first and second exhaust flow paths 1.
5 and 17, the air spring increases the pressure in the second pressure chamber 12 to a certain level and urges the diaphragm valve body 11 toward the first valve seat 4a. It is formed. The biasing force of the air spring is maximum when the valve body 11 closes the second valve seat 15a, and is minimum when the second valve seat 15a is completely opened. 16. During measurement, the biasing force of the air spring is set to be small due to the force of the pressure in the first pressure chamber 5, which increases due to the back pressure of the measuring head, so that the valve body 11 opens the first valve seat 4a and the second valve seat 4a is opened. Close the valve seat 5a,
During non-measurement, the force is set to be larger than the force due to the pressure in the first pressure chamber 5, which decreases with the back pressure of the measurement head, so that the valve body 11 closes the first valve seat 4a and opens the second valve seat 15a. are doing.

To explain in more detail, diaphragm valve body 1
The pressure of the second pressure chamber 12 acting on the valve 14, that is, the valve closing force of the air spring against the first valve seat 4a, is
16, 18 and the opening degree of the valve seat 15a, and the valve opening force F against the first valve seat 4a based on the pressure of the first pressure chamber 5 acting on the valve body 11 is as follows: F=(S-a )P+aP _S ...(1) S: Effective area of diaphragm valve body 11 a: Effective area of first valve seat 4a P: Back pressure of measurement head P _S : Expressed as pressure at inlet 2, therefore, during measurement :F>(Opening of first valve seat 4a) When not measuring: F>(Closing of first valve seat 4a) The output characteristics are respectively represented by characteristic curve _A1 and characteristic curve _A2 in FIG.

Next, the operation of the automatic on-off valve for an air micrometer having the above structure will be explained.

When not measuring, the back pressure of the measurement head is small, so the valve opening force F due to the pressure in the first pressure chamber 5 is smaller than the valve closing force due to the pressure in the second pressure chamber 12, and therefore the diaphragm valve body 11 is pressed against the first valve seat. 4a and opens the second valve seat 15a. Therefore, the air supplied from the air micrometer main body to the inlet 2 flows through the inlet side flow path 4, the second bypass flow path 13, the second pressure chamber 12, and the first and second exhaust flow paths 15, 1.
7 to the atmosphere, forming an air spring in the second pressure chamber 12, and auxiliary flow paths, that is, the inlet side flow path 4, the first bypass flow path 7, the first pressure chamber 5, and the outlet side flow path 6. from the outlet 3 to the measuring head. Therefore, the amount of air supplied to the measuring head is limited by the variable supply restrictor 8 in the first bypass flow path 7 and becomes extremely small.

Furthermore, during measurement, for example, when the measuring head is inserted into a hole in the object to be measured whose inner diameter is to be measured, the pressure in the first pressure chamber 5 also increases as the back pressure of the measuring head increases, and the diaphragm valve Since the valve opening force F of the body 11 against the first valve seat 4a is greater than the valve closing force, the diaphragm valve body 11
a is opened and the second valve seat 15a is closed.
Therefore, when the valve body 11 closes the second valve seat 15a, the valve closing force against the first valve seat 4a is applied to the throttle 1 of the second bypass flow path 13 and the second exhaust flow path 17.
4 and 18, but this maximum value max is set smaller than the maximum value Fmcx of the valve closing force F, so the valve body 11 opens the first valve seat 4a and The state is maintained by closing the second valve seat 15A. Therefore, the air supplied to inlet 2 is
It flows out to the atmosphere through the inlet side flow path 4, the second bypass flow path 13, the second pressure chamber 12, and the second exhaust flow path 17, and forms an air spring in the second pressure chamber 12. It flows out from the outlet 3 through both channels. That is, the air flowing in from the inlet 2 is divided into two parts: one that passes through the inlet side flow path 4 as it is, and one that flows into the first bypass flow path 7, and then the air flows into the first bypass flow path 7 again.
They merge in the pressure chamber 5 and reach the outlet 3 from the outlet side flow path 6.

When the measuring head is brought into a non-measuring state by being pulled out of the hole of the object to be measured, the back pressure in the measuring head decreases, and accordingly, the pressure in the first pressure chamber 5, that is, the valve opening force F against the diaphragm valve body 11. decreases and becomes smaller than the valve closing force, so that the diaphragm valve body 11 opens the second valve seat 15a and closes the first valve seat 4a, returning to the state before measurement.

Next, as mentioned above, F> during measurement,
A design method for determining necessary specifications such that F> during non-measurement will be briefly described.

Regarding the air micrometer body, the automatic on-off valve for the air micrometer, and the measuring head, R _S : Internal resistance coefficient of the air micrometer body R _V : Resistance coefficient of the automatic on-off valve for the air micrometer R _H : Resistance of the measuring head Coefficient R _SO air micrometer outlet cut-off pressure Q: If air volume is the pressure P, P _S and P _SO based on the atmospheric pressure on the measurement head side, P = R _H Q ² ...(2) P _S = ( R _H + R _V ) Q ² ...(3) P _SO = (R _H + R _V + R _S ) Q ² ... (4) It can be approximated as , F=SR _H +aR _V /R _H +R _S +R _V・R _SO …(5
), and furthermore, the resistance coefficient R _V of the automatic on-off valve for air micrometer is given by the diaphragm valve body 1
Since it is determined by one stroke x and is inversely proportional to that stroke, the difference between R _V (x ₀ ) and the value given as the function r (x-x ₁ ) of (x-x ₀ ), that is, R _V It is expressed as (x)=R _V (x ₀ )−r(x−x ₀ ) (6).

FIG. 3 shows each of the above formulas as a calculation chart. The first quadrant shows =F, the second quadrant shows =F, the third quadrant shows equation (5), and the fourth quadrant shows equation (6).For these individual characteristics, see Figure 1. can be calculated individually. To explain this FIG. 4 in more detail, point a in the same figure corresponds to the operating point _C1 in FIG. Since the applied valve opening force F becomes larger than the valve closing force, an unbalance occurs between the two forces that follow the path shown by the broken line arrow, and as a result, the diaphragm valve body 11 fully opens the valve seat 4a, and at the same time The second valve seat 15a is stroked until it is fully opened and reaches point b. The point b corresponds to the operating points D ₁ and E ₁ of the object to be measured in FIG. On the other hand, if the measuring head is removed from the object to be measured and placed in a non-measuring state, an imbalance will occur between the valve opening force F and the valve closing force, which follow the path shown by the constant chain arrow from point b. As a result, the diaphragm valve body 11 strokes until it fully closes the first valve seat 4a and simultaneously fully opens the second valve seat, reaching point a. Therefore, necessary specifications can be determined based on FIG.

As described above, according to the automatic opening/closing valve for air micrometers of the present invention, it is possible to supply the amount of air necessary for measurement during measurement, and it is possible to significantly reduce air consumption when not measuring, so that it does not affect measurement. Moreover, since the automatic on-off valve is connected and installed between the air micrometer body and the measuring head, an increase in the weight of the measuring head is avoided, and the automatic on-off valve is Since the measuring head is automatically opened and closed based on feedback of changes in back pressure during measurement and non-measurement, operability is significantly improved.

Further, in the automatic on-off valve for an air micrometer of the present invention, the inlet side flow path is connected to the first pressure chamber by two flow paths: a flow path passing through the valve seat and a first bypass flow path having a restriction. By communicating with the outlet side flow path, the flow path can be switched by the valve body that opens and closes the valve seat, making it easy to configure the valve body and set the flow rate when not measuring. Since the two pressure chambers are separated, the valve body itself opens and closes the valve seat in response to changes in pressure in the pressure chamber, eliminating the need for any other mechanism to open and close the valve body. can be simplified and made cheaper. Moreover, the second valve acts as a spring that biases the valve body toward the first valve seat.
Since the air spring in the pressure chamber is used, the structure is simple and assembly is easy, and the pressure in the second pressure chamber, that is, the biasing force of the air spring, can be changed arbitrarily by adjusting the throttle. It has the advantage that it can be adapted to various air micrometers.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the principle of the present invention,
FIG. 2 is a sectional view of an embodiment of the present invention, and FIG. 3 is a diagram for determining the specifications of each part of the present invention. 2...Inlet, 3...Outlet, 4...Inlet side channel, 4a...
Valve seat, 5... First pressure chamber, 6... Outlet side flow path, 7... First bypass flow path, 8, 14, 16, 18... Throttle,
DESCRIPTION OF SYMBOLS 11...Valve body, 12...2nd pressure chamber, 13...2nd bypass flow path.

Claims (1)

[Claims] 1. A valve seat, which is equipped with an inlet for inflowing compressed air from the air micrometer body and an outlet for supplying the compressed air to the measurement head, with an inlet side flow path formed therein, and a valve body for opening and closing the valve seat. The outlet side is communicated with the outlet side flow path through a first pressure chamber partitioned on one side, and the outlet side is communicated with the outlet side through a first bypass flow path having a restriction branched from the inlet side flow path and the first pressure chamber. A second pressure chamber formed on the other surface of the valve body and a second pressure chamber formed on the other surface of the valve body and a second pressure chamber having a restriction are connected to the flow path.
An automatic opening/closing valve for an air micrometer, characterized in that the second pressure chamber is communicated with the atmosphere via a bypass flow path, and the second pressure chamber is communicated with the atmosphere through a restriction.