Spring machining parameter acquisition method for pneumatic actuator

Abstract

The invention relates to the technical field of actuators, in particular to a spring machining parameter acquisition method for a pneumatic actuator, which comprises the following steps of: measuring valve closing thrust required for closing a valve, and measuring the working length of the valve according to a valve opening and closing stroke; according to the spring pre-pressing length and the spring rigidity, theoretical valve closing thrust is obtained; calculating a difference value between the theoretical valve closing thrust and the valve closing thrust; if the difference value is not in the self-defined difference value range, adjusting the wire diameter of the spring and the intermediate diameter of the spring until the difference value is in the self-defined difference value range; if the difference value is within the self-defined difference value range, spring machining parameters are calculated according to the spring wire diameter and the spring pitch diameter, and the spring machining parameters comprise the spring wire diameter, the spring outer diameter, the spring free length and the total number of turns of the spring. The method is easy to operate and high in efficiency, the uncertainty of traditional experience machining can be simulated and replaced through calculation, and the working efficiency can be improved while the cost can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of actuators, and in particular to a method for obtaining spring processing parameters of a pneumatic actuator. Background Art

[0002] Pneumatic spring actuators, that is, the single-acting (spring return type) type of pneumatic actuators, work on the principle of using air pressure to drive the actuator to move, and when the air source is lost, the actuator is reset by the elastic force of the spring. Pneumatic spring actuators have the characteristics of simple structure, reliable use, and easy maintenance. They are widely used in the field of industrial automation, such as controlling the opening and closing of valves. In pneumatic spring actuators, the elastic force of the spring is the key to the reset action, and its design and selection have an important impact on the performance of the actuator.

[0003] Before processing the spring, the processing personnel can measure in advance the thrust required to close the valve controlled by the actuator, and measure the working length of the spring according to the size range of the actuator cylinder. However, other processing parameters of the spring, such as the spring outer diameter, spring free length and total number of spring coils, cannot be directly measured. The traditional approach is to test by setting up springs that do not meet the specifications based on experience, which is not only time-consuming and labor-intensive, but also results in high costs.

[0004] Therefore, a new technical solution is urgently needed to solve the above technical problems. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned problems of the prior art and provide a method for obtaining spring processing parameters for a pneumatic actuator, which is used to solve the technical problem that the prior art tests springs that do not meet the specifications based on experience, which is not only time-consuming and labor-intensive, but also causes high costs.

[0006] The above objectives are achieved through the following technical solutions:

[0007] A method for obtaining spring processing parameters for a pneumatic actuator, comprising:

[0008] Measure the valve closing thrust required to close the valve, and measure the valve working length according to the valve opening and closing stroke;

[0009] According to the spring preload length and spring stiffness, the theoretical valve closing thrust is obtained, where:

[0010] Spring preload length = spring preload ratio × valve working length

[0011] Spring stiffness = (shear modulus x spring wire diameter 4 ) / spring middle diameter 4

[0012] In the formula, the value of the spring pre-compression ratio when the valve working length is less than 50 mm is 1.5 to 2; the shear modulus is determined according to the spring material and is a known parameter; the spring wire diameter is obtained by measuring the outer diameter of the cross section of the metal material constituting the spring selected by the user, and is a known parameter with adjustable data; the spring middle diameter is customized according to the spatial range of the actuator cylinder body and is a known parameter with adjustable data;

[0013] Calculating the difference between the theoretical valve closing thrust and the valve closing thrust;

[0014] If the difference is not within the custom difference range, adjusting the spring wire diameter and the spring middle diameter until the difference is within the custom difference range;

[0015] If the difference is within the user-defined difference range, the spring processing parameters are calculated according to the spring wire diameter and the spring middle diameter, and the spring processing parameters include: spring wire diameter, spring outer diameter, spring free length and total number of spring coils.

[0016] Furthermore, the custom difference range is (-10, 10).

[0017] Furthermore, the outer diameter of the spring=spring wire diameter+spring middle diameter.

[0018] Furthermore, the free length of the spring = the working length of the spring + the pre-compression length of the spring, wherein:

[0019] Spring working length = spring length when valve is open + spring working length when valve is open;

[0020] In the formula, the length of the spring when the valve is opened = the length of the spring coils + the effective number of spring coils × the reserved gap of the spring coils, and the length of the spring coils = the spring wire diameter × the total number of spring coils.

[0021] Furthermore, the total number of spring turns=the effective number of spring turns+1.5, wherein the effective number of spring turns is set by user definition.

[0022] Furthermore, the reserved gap between the spring coils=5+enlarged spring gap / effective number of spring coils, wherein the enlarged spring gap is a custom parameter.

[0023] Furthermore, the spring gap is increased to 0.

[0024] The present invention provides a method for obtaining spring processing parameters for pneumatic actuators. By combining the easily directly measured data such as the specifications of the spring metal wire, the thrust required to push the valve, and the working length of the valve, with the calculation method provided by the present solution, the processing parameters of the spring that meet the requirements can be quickly obtained. The method is simple to operate and highly efficient. It can simulate and replace the uncertainty of traditional empirical processing through calculation, which can reduce costs while improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of a method for obtaining spring processing parameters of a pneumatic actuator according to the present invention. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below based on the accompanying drawings and embodiments. The described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] like Figure 1 As shown, the present invention provides a method for obtaining spring processing parameters for a pneumatic actuator, comprising:

[0028] Measure the valve closing thrust required to close the valve, and measure the valve working length according to the valve opening and closing stroke;

[0029] According to the spring preload length and spring stiffness, the theoretical valve closing thrust is obtained, where:

[0030] Spring preload length = spring preload ratio × valve working length

[0031] Spring stiffness = (shear modulus x spring wire diameter 4 ) / spring middle diameter 4

[0032] In the formula, the value of the spring pre-compression ratio when the valve working length is less than 50 mm is 1.5 to 2; the shear modulus is determined according to the spring material (shear modulus is one of the basic physical property parameters of the material, which is the ratio of shear stress to shear strain within the limit range of elastic deformation ratio under shear stress. It characterizes the ability of the material to resist shear strain. A large modulus indicates strong rigidity of the material), which is a known parameter; the spring wire diameter is obtained by measuring the outer diameter of the cross section of the metal material constituting the spring selected by the user, which is a known parameter with adjustable data; the spring middle diameter is customized according to the spatial range of the actuator cylinder, which is a known parameter with adjustable data;

[0033] Calculating the difference between the theoretical valve closing thrust and the valve closing thrust;

[0034] If the difference is not within the custom difference range, adjusting the spring wire diameter and the spring middle diameter until the difference is within the custom difference range;

[0035] If the difference is within the user-defined difference range, the spring processing parameters are calculated according to the spring wire diameter and the spring middle diameter, and the spring processing parameters include: spring wire diameter, spring outer diameter, spring free length and total number of spring coils.

[0036] Wherein, the outer diameter of the spring = the wire diameter of the spring + the middle diameter of the spring.

[0037] Wherein, the free length of the spring = the working length of the spring + the pre-loaded length of the spring, specifically:

[0038] Spring working length = spring length when valve is open + spring working length when valve is open;

[0039] In the formula, the length of the spring when the valve is opened = the length of the spring coils + the effective number of spring coils × the reserved gap of the spring coils, and the length of the spring coils = the spring wire diameter × the total number of spring coils.

[0040] The total number of spring turns = the effective number of spring turns + 1.5, wherein the effective number of spring turns is set by user definition.

[0041] Since the spring coils cannot fit completely, it will be bad for the spring, so a gap needs to be left between one coil and another coil of the spring, that is, the reserved gap of the spring coils; the reserved gap of the spring coils = 5 + spring gap increase / number of effective coils of the spring, where the spring gap increase is a custom parameter. The spring gap increase can be 0.

[0042] As a specific embodiment of this scheme, the valve closing thrust is set to 500N, the spring pre-compression ratio is 1.3, the valve working length is 45mm, the spring wire diameter is 6mm, the spring middle diameter is 66.65mm, the spring effective turns are 5, the gap is increased to 2.5, and the trimming modulus is 9850.

[0043] The calculated theoretical valve closing thrust = 507.6N;

[0044] The difference between the theoretical valve closing thrust and the valve closing thrust is calculated as follows: 507.6-500=7.6. Since 7.6 belongs to the custom difference range of (-10, 10), the above parameter settings meet the processing parameters of the spring to be processed.

[0045] The above description is only for illustrating the implementation mode of the present invention and is not intended to limit the present invention. For those skilled in the art, any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for obtaining spring processing parameters for a pneumatic actuator, characterized in that: include; Measure the valve closing thrust required to close the valve, and measure the valve working length according to the valve opening and closing stroke; According to the spring preload length and spring stiffness, the theoretical valve closing thrust is obtained, where: Spring preload length = spring preload ratio × valve working length Spring stiffness = (shear modulus x spring wire diameter 4 ) / spring middle diameter 4 In the formula, the value of the spring pre-compression ratio when the valve working length is less than 50 mm is 1.5 to 2; the shear modulus is determined according to the spring material and is a known parameter; the spring wire diameter is obtained by measuring the outer diameter of the cross section of the metal material constituting the spring selected by the user, and is a known parameter with adjustable data; the spring middle diameter is customized according to the spatial range of the actuator cylinder body and is a known parameter with adjustable data; Calculating the difference between the theoretical valve closing thrust and the valve closing thrust; If the difference is not within the custom difference range, adjusting the spring wire diameter and the spring middle diameter until the difference is within the custom difference range; If the difference is within the user-defined difference range, the spring processing parameters are calculated according to the spring wire diameter and the spring middle diameter, and the spring processing parameters include: spring wire diameter, spring outer diameter, spring free length and total number of spring coils.

2. A method for obtaining spring processing parameters for a pneumatic actuator according to claim 1, characterized in that: The custom difference value range is (-10, 10).

3. A method for obtaining spring processing parameters for a pneumatic actuator according to claim 1, characterized in that: The outer diameter of the spring = spring wire diameter + spring middle diameter.

4. A method for obtaining spring processing parameters for a pneumatic actuator according to claim 3, characterized in that: The free length of the spring = the working length of the spring + the pre-loaded length of the spring, where: Spring working length = spring length when valve is open + spring working length when valve is open; In the formula, the length of the spring when the valve is opened = the length of the spring coils + the effective number of spring coils × the reserved gap of the spring coils, and the length of the spring coils = the spring wire diameter × the total number of spring coils.

5. A method for obtaining spring processing parameters for a pneumatic actuator according to claim 4, characterized in that: The total number of coils of the spring = the effective number of coils of the spring + 1.5, wherein the effective number of coils of the spring is set by user definition.

6. A method for obtaining spring processing parameters for a pneumatic actuator according to claim 5, characterized in that: The reserved gap of the spring parallel coils=5+enlarged spring gap / effective number of spring coils, wherein the enlarged spring gap is a custom parameter.

7. A method for obtaining spring processing parameters for a pneumatic actuator according to claim 6, characterized in that: The spring gap is increased to 0.

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