JP2002039819A - Poppet valve type flow measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a poppet valve type flow measuring device with simple constitution, easy to work, and capable of accurately detecting a flow rate. SOLUTION: This device has a poppet valve 10 for communicating with or shutting out an inflow port and an outflow part by being inserted into a body causing 1 forming the inflow port 2 and the outflow port 3 coaxially as the inflow port, and movably so as to contact with or separate from a valve seat 4 installed between the inflow port and the outflow port. The device also has a spring 11 energizing the poppet valve in the valve closing direction; a pressure receiving part 14 energizing the poppet valve in the valve closing direction by the pressure of pressure oil of the outflow port; and a projecting restriction part 12 projecting from a valve body part 10a contacting with or separating from the valve seat to a position upstream than the inflow port, and also functioning as a pressure receiving part energizing the poppet valve in the valve opening direction by the pressure of pressure fluid of the inflow port. The outer surface of the restriction part is formed by connecting plural tapered concentric conical slopes gradually forming an acute angle toward the tip of the restriction part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a poppet valve type flowmeter, and more particularly to a poppet valve type flowmeter suitable for measuring the flow rate of pressurized oil flowing in a hydraulic pipeline in a hydraulic machine such as a construction machine. The present invention relates to a flow measurement device.

[0002]

2. Description of the Related Art As a case of measuring the flow rate of pressure oil, for example, in a hydraulic shovel, there is a case where negative flow rate control, which is one type of tilt amount control of a variable displacement hydraulic pump, is performed. In this method, a flow rate measuring device is disposed in a hydraulic circuit from a hydraulic pump to a tank via a center bypass type operation valve to a tank, the flow rate flowing through the circuit is measured, and the output is used for tilt control of the hydraulic pump. The flow rate measurement device uses a poppet valve or disc, and outputs a pressure corresponding to the flow rate generated by the poppet valve or disc, or a device that electrically detects the displacement of the poppet valve or disc and outputs the displacement signal. There is.

[0003] In this prior art, a pressure corresponding to the flow rate is output, and in order to obtain this pressure, a plurality of stages of fixed throttles arranged in series are provided.

<Japanese Patent Laid-Open No. 5-202904> In this conventional technique, a displacement of a poppet valve according to a flow rate is output, and the displacement is magnetically detected by a displacement sensor. In order to obtain this displacement, the throttle portion of the poppet valve is formed with a notch (notch).

[0005] Japanese Patent Application Laid-Open No. 8-43156 discloses a configuration in which a poppet valve displacement corresponding to a flow rate is output and the displacement is electrically detected by a displacement sensor. A tapered wall surface is provided on the casing pipe side, and a throttle portion is formed between the wall surface and the valve.

<Japanese Patent No. 2693792> This prior art also has a configuration in which a poppet valve displacement corresponding to a flow rate is output and the displacement is magnetically detected by a displacement sensor. A curved wall surface is provided on the casing flow path side, and a throttle portion is formed between the wall surface and the valve.

<Japanese Patent Publication No. 62-25881> In this prior art as well, the displacement of the poppet valve according to the flow rate is output, and the displacement is electrically detected by a displacement sensor. A tapered wall surface is provided on the casing pipe side, and a throttle portion is formed between the wall surface and the valve.

[0008]

In the prior art described in Japanese Patent Application Laid-Open No. 9-4568, since a fixed throttle is provided to obtain a pressure corresponding to the flow rate, the relationship between the flow rate and the pressure becomes non-linear. For this reason, especially in a region where the flow rate is large, the pressure change becomes large, and the output (pressure) characteristics with respect to the flow rate become unstable. Therefore, the flow rate cannot be detected accurately, and there is a problem that it is difficult to apply to the pump control.

In the prior art described in Japanese Patent Application Laid-Open No. 5-202904, the poppet valve restrictor has a notch structure in order to obtain a poppet valve displacement corresponding to the flow rate. And the displacement can be made linear. However, processing of the drawing portion is complicated, and processing of the notch portion to obtain a linear output characteristic is extremely difficult. In addition, the flow field of the pressure oil tends to change depending on the arrangement of the notch and the flow path depending on the device assembly, and the output characteristics become unstable due to the influence of the fluid force. Therefore, it is difficult to accurately detect the flow rate even with this conventional technique.

In the prior art described in Japanese Patent Application Laid-Open No. 8-43156, a throttle portion is formed between the tapered wall surface provided on the casing pipe side and the valve. Therefore, if the shape of the tapered wall surface can be appropriately formed. The relationship between flow rate and displacement can be made linear. However, it is difficult and troublesome to form a tapered surface in the casing pipe.

[0011] Japanese Patent No. 2693792 and Japanese Patent Publication No.
The conventional technique described in Japanese Patent Application Laid-Open No. 2-25881 also processes a curved shape or a tapered surface on the flow path side.
There is a problem similar to that of the '56 publication.

An object of the present invention is to provide a poppet valve type flow rate measuring device which has a relatively simple structure, is easy to process, and can detect a flow rate with high accuracy.

[0013]

(1) In order to achieve the above object, the present invention provides an inflow port and an outflow port formed in a main body casing, and coaxially with the inflow port in the main body casing. A poppet valve that is movably inserted so as to be in contact with and separate from a valve seat provided between the inflow port and the outflow port, and communicates and shuts off the inflow port and the outflow port; and the inflow port of the poppet valve A spring provided on the opposite side of the poppet valve to bias the poppet valve in the valve closing direction; and a spring provided on the same side of the poppet valve as the spring, and biasing the poppet valve in the valve closing direction by the pressure of the pressure oil at the outflow port. A pressure receiving portion, which is provided on the inflow port side of the poppet valve, protrudes from a valve body portion that comes into contact with and separates from the valve seat to an upstream side of the inflow port, and is provided by pressure of pressure oil of the inflow port. Previous A convex throttle portion that also functions as a pressure receiving portion that urges the poppet valve in the valve opening direction, wherein the convex throttle portion is located between the valve seat and the valve seat when the poppet valve opens. It has an outer surface shape that forms an annular passage that increases the opening area as the amount of displacement of the poppet valve increases, and the amount of displacement of the poppet valve or the pressure difference between the inflow port and the outflow port caused by the restricting portion causes the poppet valve to move. The flow rate shall be measured.

As described above, the pressure receiving portions are provided on the inflow port and the outflow port side with respect to the poppet valve, and the poppet valve is urged in the valve opening direction and the valve closing direction by the pressure of the respective pressure oils. By providing a convex restricting portion that also serves as a pressure receiving portion acting in the valve direction, by changing the opening area between the valve seat according to the displacement amount of the poppet valve by the outer surface shape of the convex restricting portion. Since the processing portion is on the poppet valve side, the configuration is relatively simple and the processing is easy. Further, by appropriately processing the outer shape of the convex throttle portion, the output (valve displacement or pressure difference) characteristic according to the flow rate has a stable approximate linear relationship, and the flow rate can be detected with high accuracy.

(2) In the above (1), preferably, the outer shape of the convex throttle portion is gradually concentric with the center axis of the valve body portion of the poppet valve toward the tip of the throttle portion. It is connected and formed by a plurality of tapered conical slopes having acute angles.

This further facilitates the processing of the outer shape of the drawn portion.

(3) In the above (1) or (2), preferably, further provided is a circular flange provided coaxially with the poppet valve at a position downstream of the valve body of the poppet valve.

As a result, the fluid that has passed through the throttle portion hits the collar portion to generate a force in the valve opening direction, so that the force (fluid force) in the valve closing direction in the axial direction generated when the fluid passes through the throttle portion is compensated, and the flow rate characteristic Stably obtain the linearity of
Further, the flow rate can be detected with higher accuracy.

(4) In the above (1) or (2), preferably, the outer shape of the convex constricted portion is such that the opening area of the annular passage is approximately 1% of the displacement of the poppet valve. / Square function.

As a result, the flow rate detection characteristic of the displacement amount of the poppet valve with respect to the flow rate of the poppet valve or the pressure difference between the inflow port and the outflow port caused by the restrictor has a substantially linear relationship.

(5) Further, in the above (1) or (2), preferably, the outer shape of the throttle portion is such that a displacement amount of the poppet valve with respect to a flow rate of the poppet valve or an inflow port generated by the throttle portion. The flow rate detection characteristic of the pressure difference between the outlet ports is formed so as to have a substantially linear relationship.

As a result, the output (valve displacement or pressure difference) characteristic according to the flow rate has a stable approximate linear relationship, and the flow rate can be detected accurately.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a poppet valve type flow rate measuring device according to a first embodiment of the present invention.

Referring to FIG. 1, a flow rate measuring apparatus according to the present embodiment includes a casing main body 1, a poppet valve 10 disposed in the casing main body 1, and a coaxial with the poppet valve 10 via a flange 5 on the casing main body 1. Fixedly installed in
A displacement sensor 30 for detecting the displacement of the poppet valve 10. A main fluid passage having an inflow port 2 and an outflow port 3 is provided in the casing 1, and the outflow port 3 is connected to a passage portion 3a perpendicular to the inflow port 2 and the inflow port 2 is opened and connected to the passage portion 3a. The valve seat 4 is formed in the opening of the inflow port 2 with respect to the annular port portion 3b. On the opposite side of the inflow port 2 across the annular port portion 3b, the inflow port 2
Cylinder hole 1 opening in annular port portion 3b coaxially with
The cylinder portion 16 of the poppet valve 10 is slidably fitted into the cylinder hole 1a, and the cylinder portion 16 is displaced so that the poppet valve 10 comes into contact with or separates from the valve seat 4 by sliding movement. Move to inflow port 2 and outflow port 3
Communication and shut-off between them.

FIG. 2 is an enlarged view of a poppet valve portion.

The poppet valve 10 is coaxial with and integral with the above-mentioned cylinder portion 16, and has a valve body portion 10a which comes into contact with and separates from the valve seat 4, and a convex shape which is coaxial and integral with the valve body portion 10a. A constriction portion 12 and a circular collar portion formed coaxially and integrally with the valve body portion 10a in an annular port portion 3b downstream of the valve body portion 10a so as to protrude in a direction perpendicular to the axis of the poppet valve 12. 13 is provided. Aperture unit 12
Has a tapered outer surface shape protruding from the valve body portion 10a to the upstream side of the inflow port 2.

The cylinder hole 1a is opposite to the annular port portion 3b, and has a flange 5 formed coaxially with the cylinder hole 1a.
In the mounting hole 18. The flange 5 has a positioning projection 5a, which is inserted into the hole 18 and is bolted to the casing body 1.

A hole 16a is formed in the cylinder portion 16 at the end face 14 opposite to the throttle portion 12.
A spring 11 for urging the poppet valve 10 in the valve closing direction and a mandrel 20 displaced together with the poppet valve 10 are arranged in the hole 18. The mandrel 20 has a base portion 20a and a shaft portion 20b.
a, and one end of the spring 11 is pressed against the bottom of the hole 16a, and the shaft 20b of the mandrel 20 is moved from the hole 16a to the hole 18a.
A sensing rod 31 of the displacement sensor 30 is screwed to an end thereof. The other end of the spring 11 is supported on the end surface of the positioning projection 5a of the flange 5.

The hole 16a and the cylinder portion 1 of the hole 18
6 between the end face 14 and the end face of the positioning protrusion 5a.
The back pressure chamber 6 is formed through a small hole 15a and a small hole 15b in the axial direction provided in the poppet valve 10 and concave portions 20c and 20d (described later) provided in the base 20a of the mandrel 20. The pressure oil of the outflow port 3 is guided to the back pressure chamber 6 by communicating with the annular port portion 3b, and the end face 14 of the cylinder portion 16 receives the pressure to urge the poppet valve 10 in the valve closing direction (leftward in the drawing) by the pressure. Functioning as a unit. On the other hand, the throttle portion 12 of the poppet valve 10 functions as a pressure receiving portion that receives the pressure of the pressure oil flowing through the inflow port 2 and urges the poppet valve 10 in the valve opening direction.

The details of the mandrel 20 are shown in FIG. Mandrel 20
Has a base 20a and a shaft 20b, a recess 20c is formed on an end surface of the base 20a, and a plurality (four in the illustrated example) of recesses 20d are formed on a peripheral surface of the base 20a. The small hole 15 communicates with the back pressure chamber 6 via the recesses 20c and 20d in a state where the end face of the base 20a is pressed against the bottom of the hole 16a. A displacement sensor 30 is provided on the shaft portion 20b.
Screw hole 20e for screwing the sensing rod 31
Are formed.

Returning to FIG. 2, the throttle portion 12 of the poppet valve 10 will be described.
The opening area of the annular passage formed between the valve element portion 10a and the valve seat 3 when the poppet valve 10 opens is approximately a function of the displacement of the poppet valve 10 to the half power. It has an outer surface shape, so that the flow rate detection characteristic of the displacement amount of the poppet valve 10 with respect to the flow rate of the poppet valve 10 or the pressure difference between the inflow port 2 and the inflow port 3 generated by the throttle portion 12 has a substantially linear relationship. It is configured.

The above-mentioned outer surface shape of the throttle portion 12 is connected by a plurality of tapered conical slopes which are concentric with the central axis of the valve body portion 10a of the poppet valve 10 and gradually become acute angles toward the tip of the throttle portion 12. Is formed.

FIG. 4 shows how to determine the outer shape of the throttle portion 12 of the poppet valve 10 and the flow rate detection characteristics of the poppet valve 10.
This will be described with reference to FIG.

The static balance of the poppet valve 10 is αΔP = k (x + x ₀ ) + F _f (1) where ΔP: differential pressure across the poppet valve restrictor 12 x: stroke of the poppet valve restrictor 12 (valve displacement) ) X ₀ : preset length of spring 11 α: area of pressure receiving portion of poppet valve 10 (pressure receiving area) k: spring constant F _f : steady fluid force (= ρQvcosφ) φ: jet angle v: flow velocity ρ: oil density poppet Q = cA (x) 絞 り (2ΔP / ρ) (2) where A (x): opening area c of poppet valve restrictor 12:
From the flow coefficient equations (1) and (2), ignoring the steady-state fluid force F _f , Q = c√ (2 / ρ) √ (k / α) A (x) √ (x) √ (1 + x ₀ / x ) = K _q A (x) √ (x) √ (1 + x ₀ / x) (3) where K _q : constant (= c√ (2 / ρ) · √ (k /
α)) Therefore, when the proportional relationship of Q = K _q · α · x (4) is given to the flow rate and the displacement of the poppet valve 10, the opening area A (x) of the poppet valve throttle unit 12 becomes When the preset force term and the fluid force term are neglected, the equation is expressed by the following equation (5), which is a function of the square (root) of the valve displacement x.

A (x) = α√ (x) / √ (1 + x ₀ / x) ≒ α√x = πdξ√x (5) where x≫x ₀ α: proportionality constant (= πdξ) d: poppet valve In the present embodiment, the opening area given as a function of the square of the valve displacement (root) is defined as the basic opening area, and this is used as the actual poppet valve 10 in the present embodiment. In order to obtain the shape of the throttle portion 12, the outer shape of the throttle portion 12 of the poppet valve 10 is
The tapered conical surface is formed in such a manner that the tapered conical surface is formed by a plurality of tapered conical slopes that are concentric with the valve center axis and have an acute angle gradually toward the distal end on the upstream side with respect to the position where the valve seat 4 is touched. Is related to the opening area based on the taper angle of Equation (5).

That is, the taper angle of the tapered conical surface is an angle formed with the center axis of the poppet valve 10, and when this is set to a half apex angle θ as shown in FIG. 4, the edge portion of the valve seat 4 and the poppet valve The aperture area of the stop formed by a tapered surface having a half-vertical angle θ of 10 is A (x) = πdsinθ · x (1− (x / d) sinθcosθ) ≒ πdsinθ · x (6) Since the basic opening area represented by the equation (5) is equal to the basic opening area, the poppet valve half apex angle θ is given by the following equation when the spring preset force is ignored. θ = sin ^-1 (ξ / √ (x + x ₀ )) ≒ sin ^-1 (ξ / √x) (7) Thereby, the half vertex angle θ with respect to the valve displacement x is determined, and based on this, the tapered conical surface becomes It can be formed, and the valve displacement can be proportional to the flow rate.

Then, the half vertex angle θ with respect to the valve displacement x is calculated by a plurality of different valve displacements x, and the tapered conical surface of the half vertex angle θ obtained by each of the valve displacements is connected to form the narrowed portion 12. , Each valve displacement x
Thus, a proportional relationship (linear relationship) between the valve displacement and the flow rate can be obtained.

In this case, in order to improve the accuracy of the linear relationship between the flow rate and the valve displacement, the first range of the equation (7) must be satisfied over the entire range of the valve displacement x.
It is preferable to calculate and determine the half vertex angle θ of the tapered conical surface using the equation, that is, θ = sin ⁻¹ (ξ / √ (x + x ₀ )). However, especially in the region where the valve displacement x is small, the relation of x が x ₀ hardly holds. Therefore, in the region where the valve displacement x is small, the half apex angle of the tapered conical surface is calculated by the first equation of the equation (7). θ is calculated, and in a region where the valve displacement x is large where the relationship of x≫x ₀ is remarkable, the second expression of the expression (7), that is, θ ≒ sin ⁻¹ (ξ / √)
The half vertex angle θ of the tapered conical surface may be calculated in x).

In FIG. 5, the half apex angle θ of the tapered conical surface is calculated by the first expression of the expression (7), and the outer surface shape of the throttle portion 12 of the poppet valve 10 is formed by connecting a plurality of tapered conical slopes. An example of the opening area set in the case of the above is shown. In this example, the valve seat diameter d = 0.8 (cm) and the opening area coefficient ξ = 0.25 (cm
^1/2 ), the thick line indicates the preset force of the spring 11, that is, the cracking pressure ΔPo (= kx _O / a) at which the throttle portion 12 of the poppet valve 10 starts opening is ΔPo =
0 (kgf / cm ² ), and the thin line is ΔP0 = 2 (kgf / cm ² ).
cm ² ). When ΔP0 = 2 (kgf / cm ² ) is set, that is, when a preset force is applied by the spring 11,
It can be seen that the opening area is reduced and compensated to compensate for the cracking pressure ΔPo.

FIG. 6 shows the flow rate characteristics in the setting of FIG. From this figure, it can be seen that by setting the opening area to compensate for the cracking pressure ΔPo, a characteristic is obtained in which the flow rate and the valve displacement have a linear relationship. FIG. 6 also shows the case where the opening area is not corrected and the basic opening area is compensated even if there is a cracking pressure. In this case, a linear relationship cannot be obtained. FIG. 6 also shows the differential pressure characteristics in the setting of FIG. Since the differential pressure and the valve displacement are originally in a linear relationship, the flow rate and the valve displacement are in a linear relationship. As a result, the flow rate and the differential pressure are also in a linear relationship.

As described above, according to the present embodiment, the output (valve displacement or pressure difference) characteristic according to the flow rate has a stable approximate linear relationship due to the outer surface shape of the throttle portion 12 of the poppet valve 10, and the flow rate can be accurately determined. Can be detected.

Further, the structure in which the collar portion 13 is connected to the throttle portion 12 generates an axial force in the valve opening direction due to the collision of the jet flow with the collar portion 13, thereby compensating the steady fluid force in the valve closing direction. Therefore, the linearity of the flow characteristic can be stably obtained.

Further, since the poppet valve 10 is simply provided with the convex throttle portion 12 in order to obtain a linear relationship between the flow rate and the valve displacement, the structure is simple and processing is easy. Since the shape is a shape formed by connecting a plurality of tapered conical surfaces, processing becomes easy.

The mandrel 20 of the poppet valve 10 is connected to the sensing mandrel 31 of the displacement sensor 30, and the sensing mandrel 31 is displaced via the mandrel 20 with the displacement movement of the poppet valve element 10. Can be measured.

Another embodiment of the present invention will be described with reference to FIG. In the present embodiment, a differential pressure is detected as an output for a flow rate. In the figure, components equivalent to those shown in FIG. 1 are denoted by the same reference numerals.

In this embodiment, the displacement sensor 30 shown in FIG.
The mandrel 30 is removed, and the plug 32 is mounted. A differential pressure sensor 40 for measuring a differential pressure is provided in the block 50,
The block 50 is joined to the casing body 1, and the passages 7 and 8 are formed in the casing body 1, the passages 51 and 52 are formed in the block 50, and the pressure of the inflow port 2 is introduced through the passages 51 and 7. Then, the pressure of the outflow port 3 is detected through the passage 52 and the passage 8.

As described with reference to FIG. 6, the flow rate and the differential pressure are also in a linear relationship.
The pressure difference corresponding to the flow rate generated by the zero throttle unit 12 is measured by the differential pressure sensor 40, and the flow rate can be detected with high accuracy.

Next, an application example of the poppet valve type flow rate measuring device of the present invention will be described with reference to FIG. (A) Bleed-off flow rate measuring device This is an example used as flow rate measurement related to pump tilt control.
For example, open center type control valves 60, 6
1, the poppet valve type flow rate measuring device A of the present invention is disposed at the most downstream of the center bypass throttle of the control valves 60 and 61, and measures the surplus flow rate of the discharge flow rate of the hydraulic pump 62. In accordance with the surplus flow rate, the controller 63 and the electromagnetic proportional pressure reducing valve 64 control the amount of pump tilt. (B) Pump discharge flow rate measuring apparatus The poppet valve type flow rate measuring apparatus B of the present invention is disposed in the discharge path of the hydraulic pump 62, and is used as a measuring apparatus of the actual discharge flow rate. Thereby, the pump operation status is grasped and a failure diagnosis is performed. For example, the actual operation state of the pump can be grasped by comparing the flow rate based on the amount of tilt indicated by the pump variable flow rate control, the horsepower control, and the like with the actual discharge flow rate. (C) Meter-in flow rate measuring device The poppet valve type flow measuring devices C1 and C2 of the present invention are arranged on the input lines of the control valves 60 and 61, and are used as a meter-in flow rate measuring device which is one of the flow rate measurement of the valve restrictor. Used. Thereby, the actuator 6
5, 66 speed control and the like are performed. For example, actuator speed according to lever command (equivalent meter-in flow rate)
Is compared with the actual meter-in flow rate to drive the actuator.

[0050]

According to the present invention, since the opening area is changed according to the amount of displacement and the flow rate is measured by the convex throttle provided in the poppet valve, the outer shape of the convex throttle is appropriately processed. Output (valve displacement or pressure difference) according to the flow rate
The characteristics have a stable approximate linear relationship, and the flow rate can be accurately detected. Further, since the processing portion is on the poppet valve side, the configuration is relatively simple and the processing is easy.

Further, according to the present invention, since the outer shape of the convex constricted portion is continuously formed by a plurality of tapered conical slopes, the processing of the outer shape of the constricted portion is further facilitated.

According to the present invention, since the poppet valve is provided with the circular flange and the fluid passing through the throttle hits the flange to generate a force in the valve opening direction, the shaft generated when the fluid passes through the throttle is generated. The force (fluid force) in the valve closing direction is compensated, the linearity of the flow characteristic can be stably obtained, and the flow can be detected with higher accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram showing a poppet valve type flow measurement device (displacement measurement type) according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the poppet valve type flow rate measuring device shown in FIG.

FIG. 3 is a view showing details of the mandrel shown in FIG. 1;
(A) is a front view, (b) is a side view, and (c) is a perspective view.

FIG. 4 is a diagram illustrating the relationship between the half-vertical angle θ, which is the taper angle of the tapered conical surface, the valve displacement, and the opening area.

FIG. 5 is a diagram illustrating an example of an opening area set by a throttle section of the poppet valve illustrated in FIG. 1;

FIG. 6 is a diagram illustrating an example of a flow rate characteristic obtained in the setting example of the opening area illustrated in FIG. 5;

FIG. 7 is a view showing a poppet valve type flow rate measuring device (differential pressure measuring type) according to a second embodiment of the present invention.

FIG. 8 is a diagram showing an application example of a poppet valve type flow rate measuring device obtained by the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 1a Cylinder hole 2 Inflow port 3 Outflow port 4 Valve seat 5 Flange 6 Back pressure chamber 7 Passage 8 Passage 10 Poppet valve 11 Spring 12 Restricted part 13 Collar 14 End part 15a, 15b Small hole 16 Cylinder part 20 Mandrel 30 Displacement sensor 31 Displacement sensor mandrel 32 Plug 40 Differential pressure sensor 50 Block 51 Passage 52 Passage

Claims (5)

[Claims] 1. An inflow port and an outflow port formed in a main body casing, and a valve seat provided between the inflow port and the outflow port coaxially with the inflow port in the main body casing. A poppet valve which is movably inserted and communicates and shuts off between the inflow port and the outflow port, and is provided on a side of the poppet valve opposite to the inflow port,
A spring for urging the poppet valve in the valve closing direction; a pressure receiving unit provided on the same side of the poppet valve as the spring, for urging the poppet valve in the valve closing direction by the pressure of the pressure oil at the outflow port; The poppet valve is provided on the inflow port side of the poppet valve, protrudes from the valve body portion that comes into contact with and separates from the valve seat to the upstream side of the inflow port, and opens the poppet valve in the valve opening direction by the pressure of the pressure oil in the inflow port. A convex throttle portion that also functions as a pressure receiving portion that urges the valve, the convex throttle portion has a displacement amount of the poppet valve between the poppet valve and the valve seat when the poppet valve opens. Measuring an amount of displacement of the poppet valve or a flow rate of the poppet valve based on a displacement amount of the poppet valve or a pressure difference between an inflow port and an outflow port caused by a throttle portion, the outer shape defining an annular passage that increases an opening area as the number increases. Especially Poppet and Bengata flow rate measuring device. 2. The poppet valve type flow rate measuring device according to claim 1, wherein an outer surface shape of said convex throttle portion is concentric with a center axis of a valve body portion of said poppet valve toward a tip of said throttle portion. A poppet valve type flow rate measuring device, which is formed continuously by a plurality of tapered conical slopes having gradually increasing acute angles. 3. The poppet valve type flow rate measuring device according to claim 1, further comprising a circular flange provided coaxially with said poppet valve at a position downstream of a valve body of said poppet valve. A poppet valve type flow measurement device characterized by the above-mentioned. 4. The poppet valve type flow rate measuring device according to claim 1, wherein an outer surface shape of the convex throttle portion is such that an opening area of the annular passage is approximately 1 / (displacement amount) of the poppet valve. A poppet valve type flow rate measuring device characterized by being formed so as to be a function of square. 5. The poppet valve type flow rate measuring device according to claim 1, wherein an outer surface of the throttle portion has a displacement amount of the poppet valve with respect to a flow rate of the poppet valve or an inflow port and an outflow port generated by the throttle portion. A poppet valve type flow rate measuring device, wherein a flow rate detection characteristic of a pressure difference between ports has a substantially linear relationship.