CN210105998U - Metering valve with displacement self-detection function based on capacitive sensor - Google Patents

Abstract

A metering valve with displacement self-detection function based on capacitive sensor, comprising: a valve, which is cylindrical as a whole, a platform surface is machined on its outer wall, and a valve oil outlet valve and a valve oil inlet valve port are arranged on the side wall surface; a valve bushing , the whole is cylindrical, the bushing is outside the valve, the valve bushing oil outlet valve and the valve bushing oil inlet valve port are respectively set corresponding to the valve oil outlet valve port and the valve oil inlet valve port; the valve is in the middle edge of the valve bushing. Axial sliding, by adjusting the relative position of the valve and the valve bushing, to control the overlapping area of the valve inlet valve port and the valve bushing inlet valve port, as well as the overlapping area of the valve outlet valve port and the valve bushing outlet valve port The valve bushing is provided with an opening corresponding to the platform surface; the moving pole plate is fixed on the platform surface and is parallel to the axis along the valve; the displacement detection module is correspondingly arranged on the outside of the moving pole plate, and the displacement detection module is used to connect with the moving pole The plates form a capacitor bank whose value is related to the absolute displacement of the valve.

Description

Metering valve with displacement self-detection function based on capacitive sensor

technical field

The utility model relates to the field of mechanical structures and their manufacture, in particular to a metering valve with displacement self-detection function based on capacitive sensors, which is used in pneumatic and hydraulic mechanical structures in aviation, aerospace and automated machinery.

Background technique

The metering valve plays the role of metering fuel to the engine in the aerospace control system. At present, the measurement principle is to make a groove on the side wall of the bushing, and convert the displacement of the valve into a feedback voltage signal through the angular displacement sensor connected by the gear-rack system or the linear displacement sensor connected at the rear end of the valve, so as to realize the adjustment of the fuel flow rate. measurement and feedback.

However, the valve and the position sensor of the traditional linear or rotary metering valve are opened independently, that is, the sensor is placed outside the metering valve. Although the stability is good, the weight and redundancy design have their limitations. The sensor has a large self-weight. The space occupation is also large, and its application has shown disadvantages in the face of the current control requirements of integration, miniaturization, and light weight.

The principle of capacitive displacement sensing has been developed in my country for many years and has been widely used, and its stability and accuracy have been effectively verified in practical applications. The capacitive displacement sensor is integrated into the metering valve, and the original split structure is turned into an integrated component, which ensures the various functions of the original split components, reduces the weight and space occupied by them, and improves the overall performance.

At present, capacitive displacement sensors, such as the metering valve with displacement self-detection function shown in Chinese patent ZL106762161, use capacitive grid displacement measurement technology to achieve the purpose of measuring the displacement of the metering valve, but its "fixed grid" structure is complex and the driving signal is complex , and the displacement is the displacement value relative to the current zero point (the position at power-on or the reset position manually set), the zero point will be lost in the event of lightning strike, power failure, etc. If the valve is displaced during this period, the upper The displacement measured during electrical reset cannot reflect the real displacement, that is, the measurement of absolute displacement cannot be realized, and there are hidden dangers. It is not suitable for occasions where absolute displacement needs to be measured and reliability requirements are high.

Utility model content

(1) Technical problems to be solved

Based on the above problems, the present utility model provides a metering valve with a displacement self-detection function based on a capacitive sensor, so as to alleviate the complex structure of the metering valve with the self-detection function in the prior art, the complex driving signal, and the easy interference in harsh environments. It is not suitable for technical problems such as the need to measure absolute displacement and high reliability requirements.

(2) Technical solutions

The utility model provides a metering valve with a displacement self-detection function based on a capacitive sensor, which is characterized by comprising: a valve (1), which is in the shape of a column as a whole, its outer wall surface is machined with a platform surface, and the side wall surface is provided with a valve oil outlet valve Port (101) and valve inlet valve port (102); valve bushing (2), the whole is cylindrical, the bushing is outside the valve (1), corresponding to the valve outlet (101) and the valve The oil inlet valve port (102) is respectively provided with a valve bushing oil outlet valve port (201) and a valve bushing oil inlet valve port (202); the valve (1) slides axially in the valve bushing (2) , By adjusting the relative position of the valve (1) and the valve bushing (2), the overlapping area of the valve inlet valve port (102) and the valve bushing inlet valve port (202), as well as the valve outlet valve port ( 101) and the size of the overlapping area of the valve bushing oil outlet valve port (201); the valve bushing (2) is provided with an opening corresponding to the platform surface; the moving pole plate (4) is fixed on the platform surface, parallel to the axis along the shutter (1); a displacement detection module (3), correspondingly arranged on the outer side of the movable pole plate (4), comprising: the displacement detection module (3) is used for forming with the movable pole plate (4) A capacitance group, the value of the capacitance group is related to the absolute displacement of the shutter (1).

In the embodiment of the present invention, the displacement detection module (3) includes: a first static electrode plate (301), and a second static electrode plate (302), which are along the edge of the first static electrode plate (301). The shutters (1) are axially adjacent and spaced apart and insulated from each other.

In the embodiment of the present invention, the width of the first static pole plate (301) and the second static pole plate (302) is not less than the width of the moving pole plate (4).

In the embodiment of the present invention, the moving pole plate (4) is obtained by machining, and the thickness is not less than 0.3 mm.

In the embodiment of the present utility model, the moving electrode plate (4) is obtained by a surface coating process, the thickness is less than 0.3 mm, and includes: an insulating layer (401), located on the platform surface; a reflector (402), located on the on the insulating layer (401).

In the embodiment of the present utility model, the width and/or thickness of the movable pole plate (4) changes according to the law of linear and/or sinusoidal function curve; (2) and the displacement detection module (3) are insulated from each other.

In the embodiment of the present invention, the preparation material of the insulating layer includes: any one of TiO2, Al2O3, SiO2, polyimide or a mixture thereof; the preparation material of the reflector (402) includes aluminum, gold, Any one of copper, silver, graphene or a mixture thereof.

In the embodiment of the present invention, the first static pole plate (301) and the second static pole plate (302) are located above the moving pole plate (4) but are not in direct contact with them, so as to form a capacitor group, The first static pole plate (301) and the moving pole plate (4) form a capacitor C1, the second static pole plate (302) and the moving pole plate (4) form a capacitor C2, and the first static pole plate (301) and the second static pole plate (301) and the second static pole plate (301) form a capacitor C2. A capacitor C3 is formed in the area facing the polar plate (302), and the integrated capacitance Cm between the first static electrode plate (301) and the second static electrode plate (302) is formed by the capacitor C1 and the capacitor C2 in series and then the capacitor C3 in parallel. The calculation formula is:

In the formula, Cr is the equivalent capacitance after the capacitors C1 and C2 are connected in series. By detecting the Cm signal output by the displacement detection module (3), the positional relationship between the valve (1) and the valve bushing (2) can be calculated.

In the embodiment of the present invention, the width and/or thickness of the moving pole plate (4) changes according to a linear law, and the comprehensive capacitance Cm between the first static pole plate 301 and the second static pole plate 302 is calculated as in formula (2 ):

Cm=kx+b(2);

In the formula, x is the relative moving distance between the shutter 1 and the shutter bushing 2; k is the parameter related to the system structure size and dielectric constant, and b is the initial value of Cm when x=0.

In the embodiment of the present utility model, the width and/or thickness of the moving pole plate (4) changes according to the law of the sine function curve, then the expression of the width of the moving pole plate 4 is:

为x＝0时对应的相位值，h₀为x＝0时动极板4的宽度值。当动极板4的结构确定时，A、ω、

及h₀均是确定的值；对于C1及C2，有如下计算公式：where x is the relative moving distance between the valve 1 and the valve bushing 2; h is the width of the moving pole plate 4 at the x position, A is the amplitude of the sine function, ω is the angular frequency,

is the corresponding phase value when x=0, h ₀ is the width value of the moving pole plate 4 when x=0. When the structure of the moving pole plate 4 is determined, A, ω,

and h ₀ are determined values; for C1 and C2, there are the following formulas:

定义动极板4最左端边界为位移的零点，x₁、x₂分别为位移发生时第一静极板301、第二静极板302左边沿的位置，第一静极板301、第二静极板302间距为dc，则有dc＝x₂-x₁-a，公式(5)转化为Cm与x₁的函数关系Cm(x₁)；活门1与活门衬套2的相对移动距离x与x₁是一致对应的关系，是由x₁减去一个固定的偏移量δ得到，由此建立了Cm与x的计算关系Cm(x+δ)。Among them, C represents the capacitance values of C1 and C2 when the relative moving distances of the valve 1 and the valve bushing 2 are different, S is the relative area of the first static pole plate 301, the second static pole plate 302 and the moving pole plate 4, ε is the dielectric constant of the medium between the first static pole plate 301, the second static pole plate 302 and the moving pole plate 4, d is the distance between the first static pole plate 301, the second static pole plate 302 and the moving pole plate 4, a is the width of the first static pole plate 301 and the second static pole plate 302,

Define the leftmost boundary of the moving pole plate 4 as the zero point of displacement, x ₁ and x ₂ are the positions of the left edge of the first static pole plate 301 and the second static pole plate 302 when the displacement occurs, respectively. The first static pole plate 301 and the second static pole plate 301 If the distance between the static pole plates 302 is dc, then there is dc=x ₂ -x ₁ -a, and formula (5) is converted into Cm(x ₁ ), a functional relationship between Cm and x ₁ ; the relative moving distance between the shutter 1 and the shutter bushing 2 The relationship between x and x ₁ is consistent and corresponding, which is obtained by subtracting a fixed offset δ from x ₁ , thereby establishing the calculation relationship Cm(x+δ) between Cm and x.

(3) Beneficial effects

It can be seen from the above technical solutions that the metering valve with displacement self-detection function based on the capacitive sensor of the present invention has at least one or a part of the following beneficial effects:

(1) The basic structure required by the capacitor is integrated into the structure of the metering valve assembly by using the principle of capacitance, and the integrated design of the structural member and the sensor is realized;

(2) Simple structure, light weight and small volume, suitable for mass production, especially suitable for occasions where absolute displacement needs to be detected, high reliability requirements, and small installation space.

Description of drawings

FIG. 1 is a schematic structural diagram of a metering shutter with a displacement self-detection function based on a capacitive sensor according to an embodiment of the present invention.

2 is a schematic structural diagram of a metering valve with a displacement self-detection function based on a capacitive sensor according to an embodiment of the present invention.

3 is a schematic structural diagram of a valve bushing of a metering valve with displacement self-detection function based on a capacitive sensor according to an embodiment of the present invention.

4 is a top view of a moving pole plate structure according to an embodiment of the present invention.

FIG. 5 is a top view of another structure of the movable electrode plate according to the embodiment of the present invention.

FIG. 6 is a schematic structural diagram of a displacement detection module according to an embodiment of the present invention.

FIG. 7 is a schematic diagram of the cooperation relationship between the displacement detection module and the movable electrode plate in the metering valve with the displacement self-detection function based on the capacitive sensor according to the embodiment of the present invention.

8 is a schematic diagram of the core components of the capacitance group composed of the moving plate and the displacement detection module in the metering valve with displacement self-detection function based on the capacitance sensor according to the embodiment of the present invention.

FIG. 9 is a schematic diagram of the electrical connection of the capacitor bank and its equivalent circuit principle according to the embodiment of the present invention.

FIG. 10 is a schematic diagram of the relationship between the output signal of the capacitor group formed by the movable electrode plate and the displacement detection module and the displacement of the shutter according to the embodiment of the present invention.

11 is a schematic structural diagram of a moving electrode plate obtained by a surface coating process according to an embodiment of the present invention.

[Description of the main components of the embodiment of the present utility model in the accompanying drawings]

1-valve; 101-valve oil outlet; 102-valve inlet valve;

2-valve bushing; 201-valve bushing outlet valve; 202-valve bushing inlet valve;

3-displacement detection module; 301-first static plate; 302-second static plate;

4-moving plate; 401-insulating layer, 402-reflector.

Detailed ways

The utility model provides a metering valve with displacement self-detection function based on capacitance sensor, which utilizes the principle of capacitance to integrate the basic structure required by capacitance into the metering valve assembly. Structurally, the integrated design of structural components and sensors is realized. Based on traditional precision manufacturing technology, combined with special processing technology, advanced preparation methods such as coating and spraying are used to integrate the moving electrode plate and displacement detection module in the metering valve assembly, so that it is firmly bonded to the base of the metering valve assembly, and it becomes a self-detection system with absolute displacement. The functional metering valve, even if the valve moves after power failure, the displacement signal will not be lost after power-on reset, which can reflect the real positional relationship between the valve and the valve bushing. It can be used in the working environment of fuel metering, with simple structure, light weight and small volume, suitable for mass production, especially suitable for occasions where absolute displacement needs to be detected, high reliability requirements, and small installation space.

In order to make the purpose, technical solutions and advantages of the present utility model more clearly understood, the present utility model will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

In an embodiment of the present utility model, a capacitive sensor-based metering valve with displacement self-detection function is provided. With reference to FIGS. 1 to 8 , the capacitive sensor-based metering valve with displacement self-detection function includes:

The valve 1, which is cylindrical as a whole, includes:

The valve outlet 101 is located on the side wall of the valve 1, and

The valve inlet valve port 102 is located on the side wall of the valve 1, and is arranged along the axis of the valve 1 with the valve outlet valve port 101;

The platform surface, which is parallel to the axis of the shutter 1 and perpendicular to the radial direction of the shutter 1, is processed from the outer wall surface of the shutter 1;

The valve bushing 2 is cylindrical as a whole, and the bushing is outside the valve 1, including:

The valve bushing oil outlet valve port 201 is located on the side wall of the valve bushing 2, and is set corresponding to the valve oil outlet valve port;

The valve bushing oil inlet valve port 202; is located on the side wall of the valve bushing 2, and is arranged with the valve bushing oil outlet valve port 201 along the axis of the valve bushing 2;

The shutter bushing 2 is provided with an opening corresponding to the position of the platform surface.

The valve 1 slides in the valve bushing 2 along the axial direction, and by adjusting the relative positions of the valve 1 and the valve bushing 2, the overlapping area of the valve inlet valve port 102 and the valve bushing inlet valve port 202 is controlled, and The size of the overlapping area of the valve oil outlet valve port 101 and the valve bushing oil outlet valve port 201 .

The movable pole plate 4 is fixed on the platform surface and is parallel to the axis along the shutter 1 .

The displacement detection module 3 is arranged on the shutter bushing 2 corresponding to the movable pole plate 4, and includes:

the first static plate 301, and

The second static electrode plate 302 is disposed adjacent to the first static electrode plate 301 at intervals and insulated from each other;

The width of the moving pole plate 4 is not greater than the width of the displacement detection module 3 .

The displacement detection module 3 is used to form a capacitance group with the movable electrode plate 4, and the absolute displacement of the shutter 1 is deduced by measuring the capacitance group value.

The moving pole plate 4 is obtained by machining a conductive material, and the thickness is greater than 0.3 mm;

The surface insulation treatment of the moving pole plate 4;

The movable pole plate 4 and the first static pole plate 301 and the second static pole plate 302 in the displacement detection module have their lengths along the axial direction of the shutter 1, and their widths are parallel to the platform surface and perpendicular to the axial direction of the shutter 1; The dimension extending along the vertical deck face is its thickness.

The first static pole plate 301 and the second static pole plate 302 have the same shape and size.

The width and/or thickness of the moving pole plate 4 change according to the function curve law such as linearity and/or sine;

The moving pole plate 4 is insulated from the shutter 1 , the shutter bushing 2 and the displacement detection module 3 .

As shown in FIGS. 7 to 9 , the first static pole plate 301 and the second static pole plate 302 are located outside the moving pole plate 4 but are not in direct contact with them, so they are opposite to each other, thus forming a capacitor group. The pole plate 301 and the moving pole plate 4 form a capacitor C1, the second static pole plate 302 and the moving pole plate 4 form a capacitor C2, and the area facing the first static pole plate 301 and the second static pole plate 302 forms a capacitor C3. The comprehensive capacitance Cm between the static pole plate 301 and the second static pole plate 302 can be considered to be formed by C1 and C2 in series and then in parallel with C3. Its electrical connection is shown in Figure 9, and the calculation formula (1) is:

In the formula, Cr is the equivalent capacitance of C1 and C2 in series.

As shown in FIG. 8 , when the medium remains unchanged, C3 is only related to the area facing the first static pole plate 301 and the second static pole plate 302 , which is a fixed value and has nothing to do with the moving pole plate 4 ; The width varies. C1 and C2 are related to the relative positional relationship between the movable pole plate 4, the first static pole plate 301 and the second static pole plate 302, that is, related to the relative position of the valve 1 and the valve bushing 2. When the valve 1 moves , C1 and C2 change linearly, and Cm also changes linearly, as shown in Figure 10.

When the movable electrode plate 4 is in the structural form shown in FIG. 4 , and one side thereof is a straight line, the comprehensive capacitance Cm between the first static electrode plate 301 and the second static electrode plate 302 is calculated as formula (2):

Cm=kx+b (2)

In the formula, x is the relative moving distance between the valve 1 and the valve bushing 2; k is a parameter related to the structure size and dielectric constant of the system. When the system is determined, this parameter is a determined value; b is the Cm when x=0. initial value.

When the moving pole plate 4 is in the structural form shown in FIG. 5, and one of its sides is an arc, the width expression of the moving pole plate 4 is:

为x＝0时对应的相位值，h₀为x＝0时动极板4的宽度值。当动极板4的结构确定时，A、ω、

及h₀均是确定的值。对于C1及C2，有如下计算公式：where x is the relative moving distance between the valve 1 and the valve bushing 2; h is the width of the moving pole plate 4 at the x position, A is the amplitude of the sine function, ω is the angular frequency,

is the corresponding phase value when x=0, h ₀ is the width value of the moving pole plate 4 when x=0. When the structure of the moving pole plate 4 is determined, A, ω,

and h ₀ are determined values. For C1 and C2, there are the following calculation formulas:

假定动极板4最左端边界为位移的零点，x₁、x₂分别为位移发生时第一静极板301、第二静极板302左边沿的位置，设第一静极板301、第二静极板302间距为dc，则有dc＝x₂-x₁-a，公式(5)转化为Cm与x₁的函数关系Cm(x₁)。显然活门1与活门衬套2的相对移动距离x与x₁是一致对应的关系，可由x₁减去一个固定的偏移量δ得到，如图7所示，由此建立了Cm与x的计算关系Cm(x+δ)。In the formula, C represents the capacitance values of C1 and C2 when the relative moving distances of the valve 1 and the valve bushing 2 are different, S is the relative area of the first static pole plate 301, the second static pole plate 302 and the moving pole plate 4, ε is the dielectric constant of the medium between the first static pole plate 301, the second static pole plate 302 and the moving pole plate 4, d is the distance between the first static pole plate 301, the second static pole plate 302 and the moving pole plate 4, a is the width of the first static pole plate 301 and the second static pole plate 302, and the value interval of t is x～x+a;

It is assumed that the leftmost boundary of the moving pole plate 4 is the zero point of displacement, and x ₁ and x ₂ are the positions of the left edges of the first static pole plate 301 and the second static pole plate 302 respectively when the displacement occurs. The distance between the two static electrode plates 302 is dc, then dc=x ₂ -x ₁ -a, and the formula (5) is converted into Cm(x ₁ ), which is a functional relationship between Cm and x ₁ . Obviously, the relative moving distance x of the valve 1 and the valve bushing 2 is consistent with x ₁ , which can be obtained by subtracting a fixed offset δ from x ₁ , as shown in Figure 7, thus establishing the relationship between Cm and x. Calculate the relation Cm(x+δ).

When the thickness of the moving pole plate (4) changes according to a linear or sine function, expressions similar to those of formula (2) and formula (5) will also be generated, which will not be repeated here.

By detecting the Cm signal output by the displacement detection module 3, the positional relationship between the valve 1 and the valve bushing 2 can be obtained through calculation. Obviously, the mapping relationship will always exist no matter whether the power is off or not. Even if the valve 1 moves after the power is off, the displacement signal will not be lost after the power-on reset, which can reflect the real positional relationship between the valve 1 and the valve bushing 2. .

In another embodiment of the present invention, as shown in FIG. 11 , the moving pole plate 4 is obtained by a surface coating process (such as magnetron sputtering, spraying, etc.), and the thickness is less than 0.3 mm. The moving pole plate 4 includes :

The insulating layer 401 is located on the platform surface, and the preparation materials include: TiO2, Al2O3, polyimide and other insulating materials;

The reflector 402 is located on the insulating layer 401, and the preparation materials include conductive materials such as aluminum, gold, copper, silver, and graphene;

The function of the composite moving electrode plate formed by the combination of the insulating layer 401 and the reflector 402 is equivalent to that of the moving electrode plate 4 .

The width of the reflector 402 is not greater than the width of the first static electrode plate 301 and the width of the second static electrode plate 302 , as shown in FIG. 6 . The first static electrode plate 301 and the second static electrode plate 302 are located above the reflector electrode 402 but not in direct contact, and are opposite to each other, forming a capacitor group, as shown in FIGS. 7 to 8 . The absolute displacement of the shutter 1 can be calculated by detecting the value of the capacitance group.

So far, the embodiments of the present invention have been described in detail with reference to the accompanying drawings. It should be noted that, in the accompanying drawings or the text of the description, the implementations that are not shown or described are in the form known to those of ordinary skill in the technical field, and are not described in detail. In addition, the above definitions of various elements and methods are not limited to various specific structures, shapes or manners mentioned in the embodiments, and those of ordinary skill in the art can simply modify or replace them.

Based on the above description, those skilled in the art should have a clear understanding of the metering valve with displacement self-detection function based on the capacitive sensor of the present invention.

To sum up, the present utility model provides a metering valve with displacement self-detection function based on capacitive sensor, which integrates the basic structure required by the capacitance on the structure of the metering valve assembly, and realizes the integrated design of the structural member and the sensor. In order to alleviate the technical problems of the self-detection function of the metering valve in the prior art, the structure is complex, the driving signal is complex, and it is easily interfered in harsh environments, and it is not suitable for the occasions that need to measure absolute displacement and have high reliability requirements.

It should also be noted that the directional terms mentioned in the embodiments, such as "up", "down", "front", "rear", "left", "right", etc., only refer to the directions of the drawings, not It is used to limit the protection scope of the present invention. Throughout the drawings, the same elements are denoted by the same or similar reference numbers. Conventional structures or constructions will be omitted when it may cause confusion in the understanding of the present invention.

Moreover, the shapes and sizes of the components in the figures do not reflect the actual size and proportion, but merely illustrate the contents of the embodiments of the present invention. Furthermore, in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Unless known to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained from the teachings of the present disclosure. Specifically, all numbers used in the specification and claims to indicate compositional contents, reaction conditions, etc., should be understood as being modified by the word "about" in all cases. In general, the meaning expressed is meant to include a change of ±10% in some embodiments, a change of ±5% in some embodiments, a change of ±1% in some embodiments, and a change of ±1% in some embodiments. Example ±0.5% variation.

Furthermore, the word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

The ordinal numbers such as "first", "second", "third", etc. used in the description and the claims are used to modify the corresponding elements, which themselves do not mean that the elements have any ordinal numbers, nor do they Representing the order of a certain element and another element, or the order in the manufacturing method, the use of these ordinal numbers is only used to clearly distinguish an element with a certain name from another element with the same name.

Furthermore, unless the steps are specifically described or must occur sequentially, the order of the above steps is not limited to those listed above, and may be varied or rearranged according to the desired design. And the above embodiments can be mixed and matched with each other or with other embodiments based on the consideration of design and reliability, that is, the technical features in different embodiments can be freely combined to form more embodiments.

Those skilled in the art will understand that the modules in the device in the embodiment can be adaptively changed and arranged in one or more devices different from the embodiment. The modules or units or components in the embodiments may be combined into one module or unit or component, and further they may be divided into multiple sub-modules or sub-units or sub-assemblies. All features disclosed in this specification (including accompanying claims, abstract and drawings) and any method so disclosed may be employed in any combination, unless at least some of such features and/or procedures or elements are mutually exclusive. All processes or units of equipment are combined. Each feature disclosed in this specification (including accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Also, in a unit claim enumerating several means, several of these means can be embodied by one and the same item of hardware.

Similarly, it will be appreciated that in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together into a single Examples, figures, or descriptions thereof. However, this method of disclosure should not be construed to reflect an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, disclosed aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description are hereby expressly incorporated into this Detailed Description, with each claim standing on its own as a separate embodiment of this invention.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention, and are not intended to limit the present invention. In the utility model, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims (9)

1. a metering valve with displacement self-detection function based on capacitive sensor, is characterized in that, comprises: The valve (1) is cylindrical as a whole, and its outer wall surface is machined with a platform surface, and the side wall surface is provided with a valve oil outlet valve port (101) and a valve oil inlet valve port (102); The valve bushing (2) has a cylindrical shape as a whole, the bushing is outside the valve (1), and corresponding to the valve oil outlet valve port (101) and the valve oil inlet valve port (102), a valve bushing outlet port (102) is respectively provided. Oil valve port (201) and valve bushing oil inlet valve port (202); The valve (1) slides axially in the valve bushing (2), and by adjusting the relative positions of the valve (1) and the valve bushing (2), the valve oil inlet valve port (102) and the valve bushing inlet are controlled. The size of the overlapping area of the oil valve port (202), and the size of the overlapping area of the valve oil outlet valve port (101) and the valve bushing oil outlet valve port (201); The shutter bushing (2) is provided with an opening corresponding to the platform surface; A moving pole plate (4), fixed on the platform surface, parallel to the axis along the shutter (1); A displacement detection module (3), correspondingly arranged on the outside of the moving pole plate (4), includes: The displacement detection module (3) is used to form a capacitance group with the movable electrode plate (4), and the capacitance group value is related to the absolute displacement of the shutter (1). 2. The metering valve with displacement self-detection function based on capacitive sensor according to claim 1, wherein the displacement detection module (3) comprises: a first static plate (301), and The second static electrode plate (302) and the first static electrode plate (301) are disposed adjacent to each other along the axial direction of the shutter (1) and are insulated from each other. 3. The metering valve with displacement self-detection function based on capacitive sensor according to claim 2, characterized in that the width of the first static electrode plate (301) and the second static electrode plate (302) is not less than the width of the moving plate The width of the plate (4). 4. The metering valve with displacement self-detection function based on capacitive sensor according to claim 1, characterized in that, the movable electrode plate (4) is obtained by machining, and the thickness is not less than 0.3mm. 5. The metering valve with displacement self-detection function based on capacitive sensor according to claim 1, characterized in that, the movable electrode plate (4) is obtained by a surface coating process, and the thickness is less than 0.3mm, comprising: an insulating layer (401), located on the platform surface; The reflector (402) is located on the insulating layer (401). 6. The metering valve with displacement self-detection function based on capacitive sensor according to claim 1, characterized in that, the width and/or thickness of the moving pole plate (4) change according to the law of linearity and/or sine function curve ; The movable pole plate (4) and the shutter (1), the shutter bushing (2) and the displacement detection module (3) are insulated from each other. 7. The metering valve with displacement self-detection function based on capacitive sensor according to any one of claims 2 or 3, characterized in that the first static electrode plate (301) and the second static electrode plate (302) Located above the moving pole plate (4) but not in direct contact with it, it is directly opposite to form a capacitor group, the first static pole plate (301) and the moving pole plate (4) form a capacitor C1, and the second static pole plate (302) A capacitor C2 is formed with the moving electrode plate (4), a capacitor C3 is formed on the area facing the first static electrode plate (301) and the second static electrode plate (302), and the first static electrode plate (301) and the second static electrode plate (301) The comprehensive capacitance Cm between (302) is formed by the capacitor C1 and the capacitor C2 in series and then the capacitor C3 in parallel. The calculation formula is:

In the formula, Cr is the equivalent capacitance after the capacitors C1 and C2 are connected in series. By detecting the Cm signal output by the displacement detection module (3), the positional relationship between the valve (1) and the valve bushing (2) can be calculated. 8. The metering valve with displacement self-detection function based on capacitive sensor according to claim 6, characterized in that, the width and/or thickness of the moving pole plate (4) change according to a linear law, and the first static pole plate The comprehensive capacitance Cm between (301) and the second static plate (302) is calculated as formula (2): Cm=kx+b(2); where x is the relative moving distance between the valve (1) and the valve bushing (2); k is a parameter related to the system structure size and dielectric constant, and b is the initial value of Cm when x=0. 9. The metering valve with displacement self-detection function based on capacitive sensor according to claim 6, characterized in that, the width and/or thickness of the moving pole plate (4) change according to the sine function curve law, then the moving pole The expression for the width of the plate (4) is:

where x is the relative moving distance between the valve (1) and the valve bushing (2); h is the width of the movable plate (4) at the x position, A is the amplitude of the sine function, ω is the angular frequency,

is the corresponding phase value when x=0, h ₀ is the width value of the moving pole plate (4) when x=0; when the structure of the moving pole plate (4) is determined, A, ω,

and h ₀ are determined values; for C1 and C2, there are the following formulas:

Among them, C represents the capacitance values of C1 and C2 when the relative moving distances of the valve (1) and the valve bushing (2) are different, and S is the first static plate (301), the second static plate (302) and the moving distance. The relative area of the pole plate (4), ε is the dielectric constant of the medium between the first static pole plate (301), the second static pole plate (302) and the moving pole plate (4), d is the first static pole plate ( 301), the distance between the second static pole plate (302) and the moving pole plate (4), a is the width of the first static pole plate (301) and the second static pole plate (302),

The leftmost boundary of the moving pole plate (4) is defined as the zero point of displacement, and x ₁ and x ₂ are the positions of the left edges of the first static pole plate (301) and the second static pole plate (302) when the displacement occurs, respectively. If the distance between the pole plate (301) and the second static pole plate (302) is dc, then there is dc=x ₂ -x ₁ -a, and formula (5) is converted into Cm(x ₁ ), a functional relationship between Cm and x ₁ ; (1) The relative movement distance x of the valve bushing (2) is consistent with x ₁ , which is obtained by subtracting a fixed offset δ from x ₁ , thus establishing the calculation relationship Cm between Cm and x. (x+δ).

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