JP4292142B2 - Flow control valve - Google Patents

Description

  The present invention relates to a flow rate control valve capable of precisely and arbitrarily adjusting a flow rate.

  Conventionally, a precision needle valve is known as a control valve capable of precisely controlling a minute flow rate of a fluid. As the needles used here, needles having 10 kinds of MAXCV values (CV values when the valve is fully opened) according to the flow range are prepared. It is also known to perform temperature compensation by appropriately selecting the material of the needle to change the difference in diameter (outer diameter) between the needle and the orifice portion according to the temperature change (see Patent Document 1).

Conventionally, there is known a throttle valve capable of arbitrarily adjusting the flow rate and having a wide adjustment range (see Patent Document 2). In this throttle valve, a female thread is formed on the inner peripheral surface of the fluid passage of the valve body, and a male screw is formed on a part of the outer peripheral surface of the resistor. The clearance between the two screws is used as a fluid passage. Is.
Japanese Utility Model Publication No. 52-52261 JP 2000-179748 A Co-authored by Kobayashi Kiyoshi and Iida Yoshihiro, “New Version Migration”, 11th edition, Asakura Shoten Co., Ltd., October 1997, p. 48

Here, the conventional precision needle valve has the following problems to be solved. That is, in the case of a needle valve that is not temperature compensated at all, the error per 1 ° C. of temperature change is about 0.4%. The error is improved only to about 0.3% per 1 ° C. by the temperature compensation.
In almost all applications, it is desirable that this error be small, and for temperature compensation, it is desirable to limit the error to at least 0.1% per degree C.
In addition, since the flow rate adjustment range of a commercially available needle valve is a relatively narrow flow rate range, the user must select a flow rate range suitable for the application from a variety of flow rate adjustment range products. If the prediction is wrong, it is necessary to purchase a different flow rate range again, which is inconvenient.

  The conventional throttle valve changes the effective opening area of the screw thread gap as a fluid passage to change the throttle opening, but does not compensate for changes in flow rate due to temperature changes.

  The present invention has been made in order to solve the above problems, and includes a flow rate control valve in which the flow rate change rate with respect to the rotation angle is constant at any position at multiple positions, and a flow rate control valve in which the flow rate does not change even if there is a temperature change. The purpose is to provide.

  As shown in FIG. 10A, the viscosity of the gas increases as the temperature rises, and the flow resistance of the gas increases. For this reason, the flow rate of the gas flowing through the fluid control valve decreases as the temperature rises.

  Further, as shown in FIG. 10B, the viscosity of the liquid decreases as the temperature rises, and the flow resistance of the liquid becomes small. For this reason, the flow rate of the liquid flowing through the fluid control valve increases as the temperature rises.

  In this way, the viscosity of the gas and the liquid has the opposite properties to the temperature change, but the flow control valve that does not change the flow rate even if there is a temperature change by appropriately performing the reverse correction operation. It is possible to obtain.

The present invention provides a throttle valve capable of adjusting the flow rate in a wide range and having a constant flow rate change with respect to the rotation angle of the operation shaft at any adjustment position. Also, the temperature dependence of the flow rate is eliminated by offsetting the decrease in the flow rate due to the increase in the fluid viscosity coefficient and the increase in the flow rate due to the decrease in the flow resistance of the fluid.

  In order to realize the present invention, a variable throttle when the fluid passage of the valve body is a triangular spiral groove whose depth gradually decreases will be described.

First, the flow rate Q when the fluid flows in a laminar flow state through the equilateral triangular channel is obtained.
The flow rate when the fluid flows in the circular channel 27 with the radius r shown in FIG. 7 is obtained by the Hagen-Poiseuille equation. This equation is expressed by the following equation (1).
Q = πr ⁴ Δp / 8 μL (1)
Here, Q is the flow rate of the fluid flowing through the circular tube, r is the radius of the circular tube, Δp is the pressure difference in the flow direction between the fluid at the inlet and the outlet of the circular tube, μ is the viscosity coefficient of the fluid, and L is the fluid's viscosity coefficient . The length of the pipe from the entrance to the exit.

The same calculation is performed when the fluid flows through the channel 28 having a regular triangular cross-sectional shape shown in FIG.
In this case, than the movement theory (see Non-Patent Document 1), and the height of the equilateral triangle that is h, this flow path is a circular tubular imaginary circle tube radius r _e of the formula (2) below It can be calculated as an equivalent of the flow path.
r _e = h / 3 (2)
As shown in FIG. 8, h is the height of the equilateral triangle (depth of the groove).

Substituting (2) into (1), the flow rate Q in the laminar flow state is obtained.
Q = πh ⁴ Δp / 648 μL (3)
Since the flow resistance R of the circular pipe with respect to the fluid flowing in the circular pipe is R = Δp / Q, when this is substituted into the expression (3), the following expression (4) is obtained.
R = 648 μL / πh ⁴ (4)

The flow resistance R when the fluid having the viscosity coefficient μ flows through the flow path 29 having a regular triangular cross section whose depth gradually decreases in the longitudinal direction as shown in FIG. 9 is obtained.
Consider a case where the depth h of the equilateral triangular groove decreases exponentially in the longitudinal direction.
The coordinate of the entrance of the flow path 29 is set to x = 0. When the x-axis is set parallel to the longitudinal direction of the flow path, the groove depth h (x) at the point x can be expressed by the following equation.
Here, a and b are arbitrary constants, and e is the base of the natural logarithm.
h (x) = ae ^-bx (5)

From the equations (4) and (5), the fluid resistance in a minute section in the longitudinal direction of the flow path 29 is
dR = 648 μ · dx / π (ae ^−bx ) ⁴ (6)
It can be expressed as. Therefore,
dR / dx = 648 μ · e ^4bx / πa ⁴ (7)

Looking at the longitudinal direction of the flow path 29, the flow resistance from the infinity in the negative direction to the position x is obtained by integrating the above equation,
R (x) = 162 μ · e ^4bx / πa ⁴ b (8)
The flow rate flowing through the equilateral triangular groove from infinity to the position x is expressed by the following equation.
Q (x) = πa ⁴ b · e ^−4bx · Δp / 162 μ (9)

This equation (9) is a calculation formula for obtaining the flow rate of a fluid when a fluid having a viscosity coefficient μ flows through a channel having a regular triangular cross section whose depth gradually decreases in the longitudinal direction and a total length of x. . From this equation, the relationship between the flow path length x and the fluid μ and the flow rate can be calculated.

The present invention can be realized by the following configurations.
[Configuration 1]
An operating shaft and a housing which are slidably fitted to each other in the axial direction;
And the spiral grooves forming a fluid passage on one of the sliding surfaces at least one of the operating shaft and the housing,
An operation shaft moving mechanism for moving the operation shaft in the axial direction with respect to the housing;
The flow rate resistance of the fluid flowing in the spiral groove is set so that the rate of change of the flow rate of the fluid passage with respect to the constant movement amount of the operation shaft is constant at an arbitrary position in the axial direction of the operation shaft. A flow control valve formed so as to decrease or increase exponentially along the length direction according to the Hagen-Poiseuille equation .

By forming the spiral groove so that the flow resistance of the fluid flowing through the fluid passage changes exponentially along the length direction, the flow rate can be adjusted in a wide range, and the operation axis is constant at any adjustment position. A throttle valve having a constant flow rate change with respect to the amount of movement can be obtained. The constant movement amount of the operation shaft is, for example, the amount of displacement of the rotation angle of the operation shaft when the operation shaft that is screwed and supported by the housing is rotated. The rate of change in flow rate with respect to a fixed number of revolutions of the operating shaft is constant and has a wide adjustment range at any position regardless of the strength of the throttle.
Therefore, it is not necessary to prepare various valves for dealing with a wide adjustment range, and the capacity selection work is considerably simple.
The fluid passage formed by the spiral groove refers to a fluid passage in a portion of the entire length of the spiral groove where the opening surface of the spiral groove is closed by the operation shaft or the contact surface of the housing. The spiral groove includes not only a constant pitch but also a non-constant pitch.

  The fluid passage formed by the spiral groove refers to a fluid passage in a portion of the entire length of the spiral groove in which the opening surface of the spiral groove is closed by the operation shaft or the contact surface of the housing. If the section (position) of the fluid passage is changed, the depth of the spiral groove changes, so that the flow resistance can be changed. The spiral groove includes not only a constant pitch but also a non-constant pitch.

[Configuration 2]
An auxiliary sleeve is provided between the operation shaft and the housing and is fixed to one of them and slides on the other. The auxiliary sleeve is in contact with a spiral groove provided on the operation shaft. The flow control valve according to the above configuration 1, wherein the portion extends into the space in the housing.

  The portion of the auxiliary sleeve that is in contact with the spiral groove provided on the operating shaft extends into the space in the housing, so that the fluid pressure applied to the outer peripheral surface of the extended portion is equal, Since the extension portion does not require mechanical strength, the wall thickness can be reduced. By reducing the thickness of the extended portion, the fitting accuracy with the operation shaft can be lowered.

[Configuration 3]
3. The flow rate control valve according to the above configuration 1 or 2, wherein the auxiliary sleeve and the operation shaft or the housing slidably contacting the auxiliary sleeve are made of the same material or a material having a close thermal expansion coefficient.

  When there is a radial gap between the auxiliary sleeve and the operating shaft or housing that is slidably in contact with the auxiliary sleeve due to temperature changes, fluid was generated in the radial direction in addition to the fluid passage in the spiral groove. The fluid can flow through the gap and the predetermined purpose cannot be achieved. Configuration 3 has an effect of preventing the occurrence of a radial gap due to such a temperature change.

[Configuration 4]
The operation shaft and the housing are fitted to each other, and the spiral groove is provided on each contact surface of the operation shaft and the housing, and is screwed together to form a fluid passage,
The flow rate of the fluid flowing through the fluid passages so that the rate of change in the flow rate of the fluid passage is constant with respect to a constant rotation angle of the operation shaft at an arbitrary position in the axial direction of the operation shaft. The flow rate control valve according to the first aspect, wherein the resistance is formed so as to decrease or increase exponentially along the length direction according to the Hagen-Poiseuille equation.

  By forming the spiral groove so that the flow resistance of the fluid flowing through the fluid passage changes exponentially along the length direction, the flow rate can be adjusted in a wide range, and the operation shaft can be rotated at any adjustment position. A throttle valve having a constant flow rate change with respect to the angle can be obtained.

  Hereinafter, embodiments of the present invention will be described in detail for each example.

FIG. 1 is a longitudinal sectional view showing a fluid regulating valve of the first embodiment.
In FIG. 1, the fluid regulating valve 10 according to the first embodiment moves in the axial direction with respect to the operating shaft 12, the auxiliary sleeve 18 fitted to the outer periphery of the operating shaft 12, and the operating shaft 12 and the auxiliary sleeve 18. And a housing 20 which can be fitted. A spiral groove 14 is formed on one of the outer peripheral surfaces of the auxiliary sleeve 18, and a seal portion 26 with an O-ring interposed is provided on the other.

  The operation shaft 12 is provided with a thread groove 13 and is screwed and supported at one end 20a of the housing 20, and the end 16 is positioned on the other end 20b side in the housing. A knob 15 is provided at one end of the operation shaft 12. By rotating the knob 15 forward or backward, the operation shaft 12 can be reciprocated in the axial direction with respect to the housing 20. Such a configuration is an operation shaft moving mechanism that moves the operation shaft 12 in the axial direction with respect to the housing 20. However, the operation shaft moving mechanism in the present invention is not limited to this, and although not shown, the operation shaft 12 is slidably supported with respect to the housing 20 and is operated by a reciprocating drive device such as a cylinder. A configuration in which the shaft 12 is reciprocated in the axial direction is also included.

  The opening opened in the other end 20 b of the housing 20 is one fluid inlet / outlet 22, and the opening opened in the side surface of the housing is the other fluid inlet / outlet 24. A part of the spiral groove 14 is closed by a reduced diameter portion 20c provided on the inner peripheral surface of the housing 20, and the remaining portion is exposed.

A fluid passage is formed through the spiral groove 14 between one fluid inlet / outlet 22 and the other fluid inlet / outlet 24 of the housing 20. Here, the fluid passage formed by the spiral groove 14 is a portion (X1) of the entire length of the spiral groove 14 where the opening surface of the spiral groove is closed by contact with the reduced diameter portion 20c of the housing 20. A fluid passage.
In this embodiment, the fluid flows in from one fluid inlet / outlet port 22 as indicated by an arrow, and flows out from the other fluid inlet / outlet port 24 via the spiral groove 14. This fluid flow may be reversed.

  When the operating shaft 12 is rotated while holding the knob 15, the auxiliary sleeve 18 is moved in the longitudinal direction together with the operating shaft 12 by the screw groove 13, and the outer surface of the spiral groove 14 is along the inner peripheral surface of the reduced diameter portion 20 c of the housing 20. It is designed to slide. When the operation shaft 12 is rotated, the auxiliary sleeve 18 may be rotated together, but may be moved in the longitudinal direction without rotating.

  The operation shaft 12 and the housing 20 are made of materials having different thermal expansion coefficients. The housing 20 and the auxiliary sleeve 18 are made of the same material or materials having similar thermal expansion coefficients. For example, when the operation shaft 12 is made of a metal material such as brass, the housing 20 and the auxiliary sleeve 18 are made of a plastic material such as nylon or fluororesin.

  As will be described later, the spiral groove 14 allows the flow of the fluid flowing through the fluid passage so that the rate of change in the flow rate of the fluid passage with respect to the constant movement amount of the operation shaft 12 is constant at an arbitrary position in the axial direction of the operation shaft 12. The flow resistance is formed so as to decrease or increase exponentially along the length direction. When the spiral groove 14 is configured in this manner, a flow rate can be adjusted in a wide range, and a throttle valve with a constant flow rate change with respect to the displacement amount of the rotation angle of the operation shaft can be obtained at any adjustment position.

  Further, the shape of the spiral groove 14 is such that the flow rate change amount due to the change in the section (position) of the fluid passage of the spiral groove 14 and the flow rate change amount due to the change in the fluid viscous resistance cancel each other due to the temperature change. Select Even if the length of the fluid passage in the spiral groove 14 remains constant, the flow resistance can be changed because the depth of the spiral groove 14 is changed by changing the section (position) that becomes the resistance element. In this case, the effect of eliminating the temperature dependence of the flow rate can be obtained. This effect will be described later.

Consider a case where the flow rate adjustment valve 10 configured as described above is configured as follows.
That is, the cross-sectional shape of the spiral groove 14 is a regular triangle whose depth gradually decreases exponentially along the longitudinal direction. The effective length in the axial direction of the operation shaft and the housing (effective for temperature compensation due to the difference in expansion coefficient) is set to 60 mm. Brass C3604BD is used for the operation shaft 12, and nylon 66 is used for the housing 20 and the auxiliary sleeve 18. The thermal expansion coefficient (thermal expansion coefficient) of brass C3604BD is 2 × 10 ⁻⁵ / ° C., and the thermal expansion coefficient of nylon 66 is 9 × 10 ⁻⁵ / ° C. Therefore, the difference in thermal expansion coefficient between the operating shaft 12 and the housing 20 is 7 × 10 ⁻⁵ / ° C.

The viscosity coefficient μ of air becomes 1.73 times as the temperature rises from 0 degrees Celsius to 100 degrees Celsius. From the above equation (9), when the viscosity coefficient increases 1.73 times, the flow rate decreases to 1.73.

  On the other hand, when the temperature rises from 0 degrees Celsius to 100 degrees Celsius, the relative displacement between the operation shaft 12 and the housing 20 at the fluid passage portion is 0.42 mm. At this time, the fluid passage length by the spiral groove 14 becomes relatively short. Note that the thermal expansion / contraction difference in the radial direction of the operating shaft 12 is not negligible compared to the thermal expansion / contraction difference in the longitudinal direction of the operating shaft, so that there is an auxiliary between the operating shaft 12 and the housing 20. A sleeve 18 is interposed.

  Therefore, the spiral groove 14 may be designed so that the flow rate of air flowing through the spiral groove 14 with a positional deviation of 0.42 mm increases by 1.73 times. From this ratio, it can be seen that the spiral groove 14 should be designed so that the flow rate becomes half when the length of the fluid passage is shortened by 0.5 mm in the longitudinal direction of the operation shaft 12. In other words, the structure of the spiral groove 14 should be designed so that the flow resistance is doubled when the operating shaft 12 is extended by 0.5 mm in the longitudinal direction.

If the diameter of the operation shaft 12 is 6 mm and the spiral pitch is 1 mm, the spiral groove 14 is a half circumference and the length is 9 mm at 0.5 mm.
That is, when the spiral groove 14 is designed so that the flow resistance is doubled when the length of the spiral groove 14 is increased by 9 mm, the above condition is satisfied.
Calculation of the depth h of the spiral groove 14 corresponding to the position on the operation shaft 12 may be performed using the above equation (9).

In the above formula, the flow resistance from minus infinity to zero should be equal to the flow resistance from zero to +9 mm.
e ^{4bx0.9 (cm)} = 2
b = 19.254
When Δp is 10 ⁵ Pa (pascal), the flow rate is designed to be 10 ⁻⁵ m ³ / sec (= 600 ml / min).
From equation (9)

^{πa 4 b × 10 5 / 162μ} = 10 -5
μ = 1.38 × 10 ⁻⁵ (m ² / s)
a ⁴ = 162 μ × 10 ⁻¹⁰ / πb
a = 4.38 × 10 ⁻⁴
h (x) = 4.38 × 10 ⁻⁴ e ^-19.254x

  When the operation shaft 12 is made of brass (C3604BD) and the housing is made of nylon 66 and the fluid control valve is made, the flow resistance is doubled when the operation shaft 12 is rotated by a half, and when the rotation is one rotation, the flow is doubled and doubled. If the shape and pitch of the spiral groove is designed to be 16 times as long as N rotations and 4 times as many as N times, a fluid control valve that eliminates the temperature dependence of the air flow resistance can be realized.

  The operation shaft 12 may be made of stainless steel, and the housing 20 and the auxiliary sleeve 18 may be made of tetrafluoroethylene resin. The thermal expansion coefficients of the auxiliary sleeve 18 and the housing 20 are selected to be larger than the thermal expansion coefficient of the operation shaft 12.

When gas flows through the spiral groove 14, the thermal expansion coefficients of the operating shaft 12 and the housing 20 and the shape of the spiral groove 14 of the auxiliary sleeve 18 are such that the gas viscosity coefficient increases and the flow rate decreases as the temperature rises. At the same time, the gas to be used is equal to the amount of increase in the flow rate of the gas in which the section of the fluid passage changes in the direction of decreasing the fluid resistance of the spiral groove 14 due to temperature change and the fluid resistance decreases and the flow rate increases. It is selected according to. When the liquid flows through the spiral groove 14, the viscosity is opposite to that of the gas and the temperature change. Therefore, the same operation can be performed by appropriately performing the reverse correction operation. Can do.

If the coefficient of thermal expansion of the operating shaft and the housing and the shape of the spiral groove are selected according to the fluid to be used, the temperature of the flow rate can be compensated without temperature dependence.
The temperature compensation of the flow rate uses the longitudinal displacement difference due to each thermal expansion of the housing and the operating shaft, but the part provided with the spiral groove, that is, the auxiliary sleeve and the cylindrical surface part in contact with the outer surface of the spiral groove, That is, the housing is preferably made of a material having the same thermal expansion coefficient.

  By doing so, it is possible to prevent the gap between the two from expanding in the radial direction and the flow rate to change greatly, or the gap from being excessively reduced in the radial direction to prevent the operation shaft from moving. When the spiral groove 14 has an equilateral triangular cross-section when viewed from the longitudinal section of the operation shaft 12 and the depth of the equilateral triangular groove decreases exponentially in the longitudinal direction, a design for obtaining a desired shape And easy to manufacture.

FIG. 2 is a longitudinal sectional view showing a fluid regulating valve of the second embodiment.
In FIG. 2, the fluid regulating valve 30 according to the second embodiment is provided with a spiral groove 33 in the reduced diameter portion 34 a on the inner circumference on one end side of the housing 34, and the outer circumference of the auxiliary sleeve 32 fitted on the outer circumference on the terminal end side of the operation shaft 31. The surface is reciprocated along the outer surface of the spiral groove 33. Other configurations are the same as those shown in FIG. In FIG. 2, reference numeral 35 denotes a knob, 36 denotes one fluid inlet / outlet, 38 denotes the other fluid inlet / outlet, and 39 denotes a seal portion.

  When the operating shaft 31 is rotated while holding the knob 35, the auxiliary sleeve 32 moves in the longitudinal direction together with the operating shaft 31 by the screw groove 37, and the outer surface of the spiral groove 33 extends along the inner peripheral surface of the reduced diameter portion 34 a of the housing 34. It is designed to slide. When the operation shaft 31 is rotated, the auxiliary sleeve 32 may be rotated together, but may be moved in the longitudinal direction without rotating.

When the gas flows through the spiral groove 33, the thermal expansion coefficient of the auxiliary sleeve 32 and the housing 34 is selected to be larger than the thermal expansion coefficient of the operation shaft 31, and the viscosity coefficient of the gas increases and the flow rate decreases as the temperature rises. Depending on the gas used, the operation shaft and the gas flow rate decrease amount are equal to the gas flow rate increase amount at which the fluid passage length decreases due to temperature changes and the fluid resistance decreases and the flow rate increases. Each thermal expansion coefficient of the housing and the shape of the spiral groove are selected. Even when the liquid flows through the spiral groove 33, the same operation can be performed by appropriately performing the reverse correction operation.

  Although the point from which Example 1 is provided with the spiral groove in the housing side is different, the same effect is acquired. The temperature dependence of the flow rate of the fluid used can be eliminated, and the temperature compensation of the flow rate can be performed.

FIG. 3 is a longitudinal sectional view showing the fluid regulating valve of the third embodiment.
In FIG. 3, the fluid regulating valve 40 according to the third embodiment includes an operation shaft 41, an auxiliary sleeve 42 fitted on the outer periphery of the operation shaft 41, and a housing 43 fitted on the operation shaft 41 and the auxiliary sleeve 42. And. A spiral groove 44 is formed on the outer peripheral surface of the auxiliary sleeve 42. A seal portion 46 with an O-ring interposed is provided on the outer periphery of the intermediate portion of the operation shaft 41.

  The operation shaft 41 is provided with a thread groove 47 and is screwed and supported to one end 43a of the housing 43, and has a terminal end 48 on the other end 43b side in the housing. A knob 45 is fixed to one end of the operation shaft 41. The opening opened in the other end 43 b of the housing 43 is one fluid inlet / outlet 48, and the opening opened in the side surface of the housing is the other fluid inlet / outlet 49. A part of the spiral groove 44 is closed by the reduced diameter portion 43c on the side surface of the housing 43, and the remaining portion is exposed.

  A fluid passage is formed through a spiral groove 44 between one fluid inlet / outlet 48 and the other fluid inlet / outlet 49 of the housing 43. In this embodiment, the fluid flows from one fluid inlet / outlet 48 as indicated by an arrow, and flows out from the other fluid inlet / outlet 49 via the spiral groove 44. This fluid flow may be reversed.

  When the operating shaft 41 is rotated while holding the knob 45, the auxiliary sleeve 42 is moved in the longitudinal direction together with the operating shaft 41 by the screw groove 47, and the outer surface of the spiral groove 44 is along the inner peripheral surface of the reduced diameter portion 43 c of the housing 43. It is designed to slide. When the operation shaft 41 is rotated, the auxiliary sleeve 42 may be rotated together, but may be moved in the longitudinal direction without rotating.

  The auxiliary sleeve 42 and the housing 43 are made of either brass or stainless steel, and the operation shaft 41 is made of either nylon 66 or ethylene tetrafluoride resin. The coefficient of thermal expansion of the shaft 41 is selected to be large.

When the gas flows through the spiral groove 44, the thermal expansion coefficients of the operation shaft 41 and the housing 43 and the shape of the spiral groove 44 are the same as the gas flow rate decrease amount in which the gas viscosity coefficient increases and the flow rate decreases as the temperature rises. The length of the fluid passage is reduced by a temperature change, the fluid resistance is lowered, and the flow rate increase amount of the gas is increased, so that the flow rate is increased according to the gas used. Even when the liquid flows through the spiral groove 44, the same operation can be performed by appropriately performing the reverse correction operation.

  The fluid regulating valve 40 of the third embodiment is different from the first embodiment in that the thermal expansion coefficient of the operation shaft 41 is selected to be larger than the thermal expansion coefficients of the auxiliary sleeve 42 and the housing 43, but the same effect is obtained. can get. The temperature dependency of the flow rate can be eliminated by eliminating the temperature dependency of the flow rate.

FIG. 4 is a longitudinal sectional view showing a fluid regulating valve of the fourth embodiment.
In FIG. 4, the fluid regulating valve 50 according to the fourth embodiment is provided with a spiral groove 51 in the reduced diameter portion 52 a on the side surface of the housing 52, and the outer peripheral surface of the auxiliary sleeve 54 fitted to the outer periphery on the terminal side of the operation shaft 53 It slides along the outer surface of the spiral groove 51. Other configurations are the same as those shown in FIG. In FIG. 4, 55 is a knob, 56 is one fluid inlet / outlet, 57 is the other fluid inlet / outlet, and 58 is a seal portion.

  When the operation shaft 53 is rotated while holding the knob 55, the auxiliary sleeve 54 is moved in the longitudinal direction together with the operation shaft 53 by the thread groove 54, and the outer surface of the spiral groove 51 is along the inner peripheral surface of the reduced diameter portion 52 a of the housing 52. It is designed to slide. When the operation shaft 53 is rotated, the auxiliary sleeve 54 may be rotated together, but may be moved in the longitudinal direction without rotating.

The auxiliary sleeve 54 and the housing 52 are made of either brass or stainless steel, and the operation shaft 53 is made of either nylon 66 or tetrafluoroethylene resin. When the gas flows through the spiral groove 51, the coefficient of thermal expansion of the operation shaft 53 and the housing 52 and the shape of the spiral groove 51 are the same as the gas flow rate decrease amount in which the gas viscosity coefficient increases and the flow rate decreases as the temperature rises. The length of the fluid passage is reduced by a temperature change, the fluid resistance is lowered, and the flow rate increase amount of the gas is increased, so that the flow rate is increased according to the gas used. Even when the liquid flows through the spiral groove 51, the same operation can be performed by appropriately performing the reverse correction operation.

  The third embodiment is different from the third embodiment in that the spiral groove 51 is provided on the housing 52 side, but the same effect can be obtained. The temperature dependency of the flow rate can be eliminated by eliminating the temperature dependency of the flow rate.

FIG. 5 is a longitudinal sectional view showing a fluid regulating valve of the fifth embodiment.
In FIG. 5, the fluid regulating valve 60 according to the fifth embodiment includes an operation shaft 62 in which a spiral groove 61 is formed on the outer peripheral surface on the end side, and press-fitted on the outer periphery on the end side of the operation shaft 62. And a housing 64 in which an auxiliary sleeve 63 that opens and closes is fixed to the inner periphery.

  The operation shaft 62 is provided with a thread groove 65 on the outer peripheral surface on the other end side, is screwed and supported on one end 64a of the housing 64, and has a terminal end on the other end 64b side in the housing. A seal portion 69 with an O-ring interposed is provided on the outer periphery of the intermediate portion of the operation shaft 62. A knob 66 is provided at the outer end of the operation shaft 62.

  An opening opened at the other end of the housing 64 is one fluid inlet / outlet 67, and an opening opened at the side of the housing is the other fluid inlet / outlet 68. A fluid passage is formed between the one fluid inlet / outlet 67 and the other fluid inlet / outlet 68 through a spiral groove 61 whose opening is partially closed by the auxiliary sleeve 63.

  In the auxiliary sleeve 63, a portion 63 a that is in contact with the spiral groove 61 provided in the operation shaft 62 extends into a space in the housing 64. A fluid pressure in the fluid passage of the spiral groove 61 is applied to the inner peripheral surface of the extension portion 63a, and a fluid having substantially the same pressure as the fluid pressure in the fluid passage of the spiral groove 61 is applied to the outer peripheral surface. The fluid pressure in the vicinity of the inlet / outlet 68 is applied. That is, since the same fluid pressure is applied to the outer peripheral surface of the extended portion 63a, it is not affected regardless of the magnitude of the fluid pressure. For this reason, the thickness of the auxiliary sleeve 63 can be reduced. Since the auxiliary sleeve 63 is thin, the degree of press-fitting with the operation shaft 62 provided with the spiral groove 61 can be increased. Compared with the case where the auxiliary sleeve 63 is thick, the fitting accuracy between the auxiliary sleeve 63 and the operation shaft 62 can be increased.

When the operating shaft 62 is rotated while holding the knob 45, a part of the spiral groove 61 exposed at the other fluid inlet / outlet 68 is moved in the longitudinal direction of the operating shaft 62.
The housing 64 is made of either nylon 66 or ethylene tetrafluoride resin, the operation shaft 62 and the auxiliary sleeve 63 are made of either brass or stainless steel, and the auxiliary sleeve 63 and the thermal expansion coefficient of the operation shaft 62 The housing 64 is selected to have a large coefficient of thermal expansion.

  When the gas flows through the spiral groove 61, the thermal expansion coefficients of the operation shaft 62 and the housing 64 and the shape of the spiral groove 61 are the same as the gas flow rate decrease amount in which the gas viscosity coefficient increases and the flow rate decreases as the temperature rises. The length of the fluid passage is relatively decreased by the temperature change, the fluid resistance is lowered, and the flow rate increase amount of the gas is increased so as to be equal to the gas flow increase amount. Even when the liquid flows through the spiral groove 61, the same operation can be performed by appropriately performing the reverse correction operation.

  If the coefficient of thermal expansion of the operating shaft and the housing and the shape of the spiral groove are selected according to the gas to be used, the flow rate does not depend on the temperature and the flow rate can be compensated.

FIG. 6 is a longitudinal sectional view showing a part of the fluid regulating valve of the sixth embodiment.
A fluid control valve 70 according to the sixth embodiment illustrated in FIG. 6 includes an operation shaft 71 and a housing 72 fitted to the operation shaft 71. Although the fluid regulating valve 70 is not shown as an overall configuration, it is basically the same as the configuration of the operating shaft and the housing fitted to the operating shaft in the embodiment shown in FIGS.

The fluid passage is formed by screwing into the contact surfaces of the operating shaft 71 and the housing 72 between the one fluid inlet / outlet 73 and the other fluid inlet / outlet 74, that is, the outer peripheral surface of the operating shaft 71 and the inner peripheral surface of the housing 72. Spiral grooves 75 and 76 are formed respectively.
Both spiral grooves 75 and 76 have a flow resistance of the fluid flowing through the fluid passage so that the rate of change of the fluid passage flow rate with respect to a constant rotation angle of the operation shaft is constant at an arbitrary position in the axial direction of the operation shaft. It is formed so as to decrease or increase exponentially along the length direction. For example, the flow rate is halved each time the operation shaft 71 is rotated once.

Such spiral grooves 75 and 76 are formed as follows, for example.
That is, a taper is provided on the outer peripheral surface of one end of the operation shaft 71, and a thread groove 75 is provided on the taper surface. On the other hand, a screw groove 76 that matches the screw groove of the operation shaft 71 is provided on the cylindrical inner peripheral surface of the housing 72. Next, the crest portion of the thread groove 75 of the operation shaft 71 is cut so as to satisfy the above-described conditions. The crest portion of the thread groove 75 of the operation shaft 71 is gradually cut deeper toward the tip of the operation shaft 71 as shown in the figure.

  With this configuration, it is possible to obtain a throttle valve in which the flow rate can be adjusted in a wide range and the flow rate change with respect to the rotation angle of the operation shaft 71 is constant at any adjustment position. That is, a valve having a wide adjustment range in which the ratio of the flow rate change with respect to the constant rotation speed of the operation shaft 71 is constant at any position of the throttle is obtained.

  In each of the above-described embodiments, temperature compensation is performed using a difference in thermal expansion between two types of materials having greatly different thermal expansion coefficients such as a combination of plastic and metal, but the present invention is not limited to this. In addition, the present invention includes a method using a bimetal that causes mechanical deformation due to temperature, a driving element of a liquid enclosure, and the like. The present invention can be suitably applied to a proportional valve, a direct acting valve, a damper, and the like that greatly adjust the fluid flow rate.

1 is a longitudinal sectional view showing a fluid control valve of Example 1. FIG. 6 is a longitudinal sectional view showing a fluid regulating valve of Example 2. FIG. 6 is a longitudinal sectional view showing a fluid regulating valve of Example 3. FIG. 6 is a longitudinal sectional view showing a fluid regulating valve of Embodiment 4. FIG. FIG. 10 is a longitudinal sectional view showing a fluid regulating valve of Example 5. FIG. 10 is a longitudinal sectional view showing a part of a fluid regulating valve of Example 6. It is explanatory drawing of the type | formula which calculates | requires the flow volume in case a fluid flows into the circular tubular flow path of radius r. It is explanatory drawing of the type | formula which calculates | requires the flow volume when a fluid flows into the flow path whose cross-sectional shape is a regular triangle. It is explanatory drawing of the type | formula which calculates | requires the flow resistance R when the fluid of viscosity coefficient ( mu) flows into the flow path of a regular triangle in cross-sectional shape. It is a diagram which shows the temperature change of the viscosity of gas and a liquid.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fluid control valve 12 Operating shaft 13 Screw groove 14 Spiral groove 15 Knob 16 Terminal 18 Auxiliary sleeve 20 Housing 22 One fluid inlet / outlet 24 The other fluid inlet / outlet 26 Seal part

Claims (4)

An operating shaft and a housing which are slidably fitted to each other in the axial direction;
A spiral groove that forms a fluid passage in the sliding surface of at least one of the operating shaft and the housing;
An operation shaft moving mechanism for moving the operation shaft in the axial direction with respect to the housing;
The spiral groove is formed so that the rate of change of the flow rate of the fluid passage with respect to a certain amount of movement of the operating shaft at a given position in the axial direction of the operating shaft is constant when expressed by an exponential slope. A flow control valve formed so that a flow resistance of a fluid flowing through a passage gradually decreases or increases exponentially obtained by the Hagen-Poiseuille equation along the length direction. An auxiliary sleeve is provided between the operation shaft and the housing and is fixed to one of them and slides on the other . The auxiliary sleeve is in contact with a spiral groove provided on the operation shaft. 2. A flow control valve according to claim 1, wherein a portion extends into a space in the housing. The flow control valve according to claim 1 or 2, wherein the auxiliary sleeve and the operating shaft or the housing slidably contacting the auxiliary sleeve are made of the same material or a material having a close thermal expansion coefficient. The operation shaft and the housing are fitted to each other, and the spiral groove is provided on each contact surface of the operation shaft and the housing, and is screwed together to form a fluid passage,
The spiral grooves are arranged so that the rate of change of the flow rate of the fluid passage with respect to a constant rotation angle of the operating shaft at an arbitrary position in the axial direction of the operating shaft is constant when expressed by an exponential slope. 2. The flow control valve according to claim 1, wherein the flow resistance of the fluid flowing in the fluid passage is formed so as to gradually decrease or increase exponentially obtained by the Hagen-Poiseuille equation along the length direction.

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