Pneumatic pressure arithmetic device

Abstract

To generate a pneumatic output with push-pull characteristics.SOLUTION: A pneumatic pressure arithmetic device comprises: a push port 321 which receives a supply pressure as input and outputs a push pressure; a pull port 331 which outputs a pull pressure; a first atmospheric pressure chamber 111 and a second atmospheric pressure chamber 112 into which atmospheric pressure is introduced; a first branch port 322 which connects the push port and the first atmospheric pressure chamber; a second branch port 332 which connects the pull port and the second atmospheric pressure chamber; a first pressure plate 121 provided in the first atmospheric pressure chamber so as to be capable of closing a first opening of the first branch port; a second pressure plate provided in the second atmospheric pressure chamber so as to be capable of closing a second opening 332F of the second branch port 122 and linked to the first pressure plate so as to move in a direction that closes the first opening and opens the second opening; a biasing member 23 which biases the second pressure plate to close the second opening; and a pressure chamber which applies input pressure to the first pressure plate in opposition to the biasing force.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a technique for outputting a push pressure proportional to an input pressure and a pull pressure inversely proportional to the input pressure.

Background Art

[0002] Conventionally, it has been possible to generate a pneumatic output having a push-pull characteristic by electric input using two electropneumatic transducers, but it is extremely costly and complicated adjustment is required to obtain complete inversion characteristics.

[0003] In addition, as a technique using pneumatic pressure by the inventor of the present application, a cylinder body having a pressure flange, a body having an accommodation chamber for accommodating the cylinder body, a first diaphragm attached to the rear end of the cylinder body to form a first pressure chamber in the accommodation chamber, a second diaphragm attached to the front end of the cylinder body to form a second pressure chamber in the accommodation chamber, and a nozzle formed in the body and communicating with the second pressure chamber and having an opening that functions as a flapper facing the pressure flange, and supplying compressed air to the first pressure chamber and the second pressure chamber to move the cylinder body to a position where the internal pressures of both are balanced, an actuator characterized by this is known (see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Generating a pneumatic output having a push-pull characteristic at a lower cost is one of the problems.

[0006] Embodiments of the present invention are made to solve the above-described problems, and an object thereof is to provide a technique for generating a pneumatic output having push-pull characteristics at a lower cost.

Means for Solving the Problems

[0007] In order to solve the above-described problems, a pneumatic arithmetic unit that outputs a push pressure proportional to an input pressure and a pull pressure inversely proportional to the input pressure, wherein a supply pressure is input and the push pressure is output. A push port that is an air flow path, a pull port that is an air flow path for inputting the supply pressure and outputting the pull pressure, a first atmospheric pressure chamber and a second atmospheric pressure chamber into which atmospheric pressure is introduced, and the push port A first branch port that is a branch air flow path that communicates the push port and the first atmospheric pressure chamber, a second branch port that is a branch air flow path that branches from the pull port and communicates the pull port and the second atmospheric pressure chamber, and the first A first pressure plate provided in the first atmospheric pressure chamber so as to be able to close a first opening on the first atmospheric pressure chamber side of the branch port, and a second opening on the second atmospheric pressure chamber side of the second branch port. A second pressure plate provided in the second atmospheric pressure chamber so as to be able to close the first pressure plate, and when the first pressure plate is moved in a direction to close the first opening, the second pressure plate is moved in a direction to open the second opening. A second pressure plate connected to the first pressure plate, a biasing member that biases the second pressure plate so as to close the second opening, and the input pressure is applied to the first pressure plate so as to resist the biasing force of the biasing member. And a pressure chamber provided.

Effects of the Invention

[0008] According to the embodiment of the present invention, it is possible to generate a pneumatic output having push-pull characteristics at a lower cost.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0011] (Overall Configuration of Pneumatic Arithmetic Unit) The overall configuration of the pneumatic arithmetic unit according to the present embodiment will be described. FIGS. 1 and 2 are a plan view and a front view showing the configuration of the pneumatic arithmetic unit according to the present embodiment, respectively. FIG. 3 is a sectional view taken along line A-A of FIG. 1. FIG. 4 is a pneumatic circuit diagram of the pneumatic arithmetic unit according to the present embodiment. Note that FIG. 2 shows the pneumatic arithmetic unit as viewed from the lower side in FIG. 1. Also, in FIGS. 1 and 2, the internal configuration is indicated by a dotted line.

[0012] As shown in FIGS. 1 to 4, the pneumatic arithmetic unit 1 according to the present embodiment includes a body 10, a cover plate 20, and a manifold base 30. Both the body 10 and the cover plate 20 are formed in a substantially cylindrical shape. The lower surface of the cover plate 20 is connected to the upper surface of the body 10, and the body 10 and the cover plate 20 connected to each other form a single substantially cylindrical shape as a whole. The manifold base 30 is formed in a substantially rectangular parallelepiped shape, and its upper surface is connected to the lower surface of the body 10 so that the longitudinal direction faces one direction in the radial direction of the body 10 and the cover plate 20 (the vertical direction in FIG. 1).

[0013] The body 10 is formed with a first atmospheric pressure chamber 111 that opens to the lower surface side, a second atmospheric pressure chamber 112 that opens to the upper surface side, and two flow paths that will be described in detail later. Inside the body 10, a first pressure plate 121, a second pressure plate 122, an input diaphragm 131, an output diaphragm 132, and a plurality of connecting rods 150 are provided. Also, each of the two flow paths opens at the upper and lower surfaces of the body 10, and a fixed orifice OR for reducing the gas flow rate is provided at each of these four openings.

[0014] The body 10 is formed with an atmospheric pressure port 19 that communicates the first atmospheric pressure chamber 111 and the second atmospheric pressure chamber 112 with the outside of the body 10. By this atmospheric pressure port 19, the pressure in the space defined by the first atmospheric pressure chamber 111 and the input diaphragm 131 (hereinafter, this space is simply referred to as the first atmospheric pressure chamber 111) and the pressure in the space defined by the second atmospheric pressure chamber 112 and the output diaphragm 132 (hereinafter, this space is simply referred to as the second atmospheric pressure chamber 112) become equal to the atmospheric pressure, that is, the atmospheric pressure outside the air pressure arithmetic unit 1.

[0015] The cover plate 20 is formed with a housing chamber 201 that opens to the lower surface side, two flow paths (one not shown), a push output hole 21, and a pull output hole 22. Inside the cover plate 20, a bias spring 23 and a third pressure plate 231 are provided. The cover plate 20 is assembled to the body 10 such that the opening of the housing chamber 201 overlaps the opening of the second atmospheric pressure chamber 112 and each of the two flow paths of the cover plate 20 communicates with the corresponding two flow paths of the body 10. The housing chamber 201 and the second atmospheric pressure chamber 112 are fluidly isolated from each other by the output diaphragm 132.

[0016] The manifold base 30 is formed with a pressure chamber 301 that opens to the upper surface side, three flow paths described later, a push input hole 31 that communicates the pressure chamber 301 with the outside of the manifold base 30, and two supply pressure holes 32 and 33 that communicate each of two of the three flow paths with the outside of the manifold base 30. The manifold base 30 is assembled to the body 10 such that the opening of the pressure chamber 301 overlaps the opening of the first atmospheric pressure chamber 111, and each of the two flow paths communicating with each of the two supply pressure holes 32 and 33 communicates with the two flow paths of the corresponding body 10. The pressure chamber 301 and the first atmospheric pressure chamber 111 are fluidly isolated by the input diaphragm 131. One of the three flow paths of the manifold base 30 is formed as a connection port 34 described later.

[0017] When the cover plate 20 and the manifold base 30 are assembled to the body 10, the flow paths formed in each of them are connected, and a push port 321 and a pull port 331 are formed in the pneumatic arithmetic unit 1. The push port 321 communicates the supply pressure hole 32 and the push output hole 21. The pull port 331 communicates the supply pressure hole 33 and the pull output hole 21. The connection port 34 fluidly connects the push port 321 and the pull port 331 in the manifold base 30. Note that a fixed orifice OR is provided between the cover plate 20 and the manifold base 30 at each of the push port 321 and the pull port 331 as described above. Thereby, the pressure of the push port 321 and the pressure of the pull port 331 can change independently of each other on the downstream side of the fixed orifice OR, that is, in the portion formed by the body 10 and the cover plate 20.

[0018] Inside the body 10, as additional flow paths, a first branch port 322 and a second branch port 332 are formed. The first branch port 322 branches from the push port 321 and communicates the first atmospheric pressure chamber 111 with the push port 321. The second branch port 332 branches from the pull port 331 and communicates the second atmospheric pressure chamber 112 with the pull port 331. The first branch port 322 opens in a closable manner by the first pressure plate 121 on the upper inner wall of the first atmospheric pressure chamber 111, and a nozzle flapper 322F having a perfect circular opening is provided at this opening. The second branch port 332 opens in a closable manner by the second pressure plate 122 on the lower inner wall of the second atmospheric pressure chamber 112, and a nozzle flapper 332F having a perfect circular opening is provided at this opening. Note that the opening area of the nozzle flapper 322F and the opening area of the nozzle flapper 332F are equal.

[0019] (Configuration of the member to be accommodated) The member to be accommodated according to the present embodiment, that is, each member accommodated in the first atmospheric pressure chamber, the second atmospheric pressure chamber, the pressure chamber, and the accommodation chamber will be described.

[0020] Both the input diaphragm 131 and the output diaphragm 132 are members formed in a substantially film shape. The input diaphragm 131 is provided so as to cover the entire opening of the first atmospheric pressure chamber 111, whereby the first atmospheric pressure chamber 111 and the pressure chamber 301 are isolated from each other. The output diaphragm 132 is provided so as to cover the entire opening of the second atmospheric pressure chamber 112, whereby the second atmospheric pressure chamber 112 and the accommodation chamber 201 are isolated from each other.

[0021] Both the first pressure plate 121 and the second pressure plate 122 are members formed in a substantially disk shape. The first pressure plate 121 is disposed in the first atmospheric pressure chamber 111 with the opening closed by the input diaphragm 131 in a state where one flat surface portion faces upward. The second pressure plate 122 is disposed in the second atmospheric pressure chamber 112 with the opening closed by the output diaphragm 132 in a state where one flat surface portion faces downward.

[0022] Each of the plurality of connecting rods 150 is a substantially rod-shaped member extending in one direction, and is movably provided in the body 10 in the vertical direction with its extending direction facing the vertical direction. Each of the plurality of connecting rods 150 has its lower end connected to the first pressure plate 121 and its upper end connected to the second pressure plate 122. Thereby, the first pressure plate 121 and the second pressure plate 122 are provided in the body 10 so as to be interlocked and movable only in the vertical direction.

[0023] The separation distance between the first pressure plate 121 and the second pressure plate 122, that is, the distance from the upper surface of the first pressure plate 121 to the lower surface of the second pressure plate 122, is larger than the distance from the lower end of the nozzle flapper 322F to the upper end of the nozzle flapper 332F. Thereby, when the first pressure plate 121 closes the nozzle flapper 322F, a gap is generated between the second pressure plate 122 and the nozzle flapper 332F. Similarly, when the second pressure plate 122 closes the nozzle flapper 332F, a gap is generated between the first pressure plate 121 and the nozzle flapper 322F.

[0024] The bias spring 23 is a biasing member that biases the third pressure plate 231 by an elastic force, and is configured as a compression spring in the present embodiment. The third pressure plate 231 has a substantially disk-shaped large-diameter portion having a large diameter and a substantially columnar small-diameter portion having a small diameter. The small-diameter portion is connected to a plane on one side of the large-diameter portion so as to be substantially concentric with the large-diameter portion. One end of the bias spring 23 is fixed to the upper inner wall of the accommodation chamber 201 so that the biasing force faces downward, and the other end of the bias spring 23 is fixed or abutted against the upper surface of the large-diameter portion of the third pressure plate 231. Further, the small-diameter portion of the third pressure plate 231 is inserted into the other end of the bias spring 23. The third pressure plate 231 presses the second pressure plate 122 downward via the output diaphragm 132 by being biased downward by the bias spring 21.

[0025] (Operation of the pneumatic arithmetic unit) The operation of the pneumatic arithmetic unit according to this embodiment will be described. FIGS. 5 to 7 are schematic diagrams showing a pneumatic arithmetic unit with a push input of zero, a pneumatic arithmetic unit with a push input equal to the push output, and a pneumatic arithmetic unit with a maximum push input, respectively.

[0026] The pneumatic arithmetic unit 1 is used by allowing air for control with a fluctuating pneumatic pressure to flow into the push input hole 31 and allowing air with a constant pneumatic pressure to flow into either one of the two supply pressure holes 32 and 33. In this embodiment, it is assumed that the supply pressure hole 33 is closed and the pneumatic arithmetic unit 1 is used by allowing air to flow in from the supply pressure hole 32.

[0027] The input pressure Pin of the air flowing in from the push input hole 31 (hereinafter referred to as the input pressure Pin) is applied to the first pressure plate 121 via the input diaphragm 131 that isolates the pressure chamber 301 and the first atmospheric pressure chamber 111. By adjusting this input pressure Pin, the separation distance G1 between the tip of the nozzle flapper 322F and the first pressure plate 121 and the separation distance G2 between the tip of the nozzle flapper 332F and the second pressure plate 122 are adjusted, and the pressure released from the nozzle flapper 322F to the first atmospheric pressure chamber 111 and the pressure released from the nozzle flapper 332F to the second atmospheric pressure chamber 112 are adjusted.

[0028] By adjusting the separation distances G1 and G2, the pneumatic pressure of the air flowing out from the push output hole 21 (hereinafter referred to as the push pressure Pout1) and the pneumatic pressure of the air flowing out from the pull output hole 22 (hereinafter referred to as the pull pressure Pout2) are adjusted. At this time, since the total distance between the separation distance G1 and the separation distance G2 is always constant, the pull pressure and the push pressure are inversely proportional. Also, since force balance is established, the push pressure Pout1 is equal to the input pressure Pin. Therefore, the push pressure Pout1 is proportional to the input pressure Pin, and the pull pressure Pout2 is inversely proportional to the input pressure Pin.

[0029] When the input pressure Pin is zero, the second pressure plate 122 is biased downward only by the reaction force Fsp of the bias spring 23, and the second pressure plate 122 contacts the nozzle flapper 332F. In this state, as shown in FIG. 5, since the separation distance G1 becomes maximum, the nozzle flapper 322F is in the fully open state, and since the separation distance G2 becomes zero, the nozzle flapper 332F is in the fully closed state.

[0030] When the opening area of the nozzle flapper 332F is S2, the force equilibrium equation regarding the reaction force Fsp is Fsp = Pout2 × S2. Here, S2 = πd2 × d2, and d2 is the radius of the opening of the nozzle flapper 332F.

[0031] When the input pressure Pin is medium, that is, when it is the pressure that is half of the maximum pressure, the push pressure Pout1 is adjusted to be equal to the input pressure Pin by force balance control. When the input pressure Pin is medium, as shown in FIG. 6, the separation distances G1 and G2 become equal, and both the nozzle flapper 322F and the nozzle flapper 332F are in the half-open state.

[0032] When the input pressure Pin is the maximum pressure, as shown in FIG. 7, since the separation distance G1 becomes zero, the nozzle flapper 322F is in the fully closed state, and since the separation distance G2 becomes maximum, the nozzle flapper 332F is in the fully open state.

[0033] As described above, according to the pneumatic pressure calculation device 1 according to the present embodiment, it is possible to generate a pneumatic pressure output having a push-pull characteristic at a lower cost as compared with the case where two electropneumatic transducers are used. Such a pneumatic pressure calculation device 1 can be used, for example, for position control of a metal diaphragm actuator.

[0034] In addition, in this embodiment, although the push port 321 and the pull port 331 are fluidly connected by the connection port 34, by blocking the connection port 34 to cut off the push port 321 and the pull port 331 and allowing different gases to flow into the supply pressure hole 32 and the supply pressure hole 33, the pneumatic arithmetic unit 1 can be used as a gas blender.

[0035] The embodiments of the present invention are presented as examples and are not intended to limit the scope of the invention. This novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0036] 1 Pneumatic arithmetic unit 23 Bias spring (biasing member) 111 First atmospheric pressure chamber 112 Second atmospheric pressure chamber 121 First pressure plate 122 Second pressure plate 321 Push port 322 First branch port 331 Pull port 331F Nozzle flapper (first opening) 332 Second branch port 332F Nozzle flapper (second opening)

Claims

1. A pneumatic computing device that outputs a push pressure proportional to an input pressure and a pull pressure inversely proportional to the input pressure, a push port that is an air flow path through which a supply pressure is input and that outputs the push pressure, a pull port that is an air flow path through which the supply pressure is input and that outputs the pull pressure, a first atmospheric pressure chamber and a second atmospheric pressure chamber into which atmospheric pressure is introduced, a first branch port that is an air flow path branching from the push port and communicating the push port with the first atmospheric pressure chamber, a second branch port that is an air flow path branching from the pull port and communicating the pull port with the second atmospheric pressure chamber, a first pressure plate provided in the first atmospheric pressure chamber so as to be able to close a first opening on the first atmospheric pressure chamber side of the first branch port, a second pressure plate provided in the second atmospheric pressure chamber so as to be able to close a second opening on the second atmospheric pressure chamber side of the second branch port, and connected to the first pressure plate so as to move in a direction to open the second opening when the first pressure plate is moved in a direction to close the first opening, a biasing member that biases the second pressure plate so as to close the second opening, and a pressure chamber provided so as to apply the input pressure to the first pressure plate so as to resist the biasing force of the biasing member The pneumatic computing device comprising.

2. The pneumatic computing device according to claim 1, wherein the supply pressure is input to the push port and the pull port from the same supply pressure hole.

3. The pneumatic computing device according to claim 1, wherein the supply pressure is input to the push port from a first supply pressure hole and the supply pressure is input to the pull port from a second supply pressure hole.

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