A torque motor current torque coefficient and magnetic stiffness measurement system and method

Abstract

The application belongs to the technical field of torque motor measurement, and discloses a torque motor current torque coefficient and magnetic stiffness measurement system, which comprises a base, a support frame, a horizontal moving frame, a pulley support, a force sensor and a displacement sensor, the base is provided with the support frame, the support frame is provided with the horizontal moving frame capable of moving horizontally relative to the support frame, the horizontal moving frame is provided with the pulley support at the top, the pulley support is provided with a pulley structure, one end of the pulley structure is provided with a load, and the other end of the pulley structure is connected with the armature end of the measured torque motor through the force sensor; the measured torque motor is placed on the base, and the displacement sensor is arranged on the base to measure the displacement of the measured torque motor. The system designed by the application is simple and reliable, the system and method can be used to measure the current torque coefficient and magnetic stiffness of various types of torque motors, and the system has good versatility.

Description

Technical Field

[0001] This invention belongs to the field of torque motor measurement technology, and relates to a parameter measurement system and method for torque motors, specifically a measurement system and method for the current torque coefficient and magnetic stiffness of a torque motor. Background Technology

[0002] The torque motor is a core component of an electro-hydraulic servo valve. It mainly consists of a magnetic circuit structure and an armature assembly. When current is input, the magnetic circuit structure generates an electromagnetic attraction at the air gap, causing the armature assembly to deflect under the electromagnetic torque, thereby controlling the pressure change in the lower oil circuit. In engineering calculations, the electromagnetic torque T... d It can be expressed as a function of the input current i and the armature rotation angle θ, i.e.

[0003] T d =k t i+k m θ

[0004] In the formula, kt is the current torque coefficient, Nm / A; km is the magnetic stiffness, Nm / rad.

[0005] Therefore, in order to understand the performance of a torque motor, it is necessary to measure and solve for the current torque coefficient kt and magnetic stiffness km of the torque motor.

[0006] Currently, there are no simple direct methods or means to measure the current torque coefficient kt and magnetic stiffness km of a torque motor. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a measurement system and method for the current torque coefficient and magnetic stiffness of a torque motor. This system can easily and quickly measure the current torque coefficient kt and magnetic stiffness km of a torque motor, has high measurement efficiency, can be used repeatedly, and is applicable to various torque motors.

[0008] The technical solution of the present invention is as follows:

[0009] A measurement system for the current torque coefficient and magnetic stiffness of a torque motor includes a base, a support frame, a horizontally movable frame, a pulley bracket, a force sensor, and a displacement sensor. The support frame is mounted on the base, and the horizontally movable frame, which can move horizontally relative to the support frame, is mounted on the support frame. The pulley bracket is mounted on the top of the horizontally movable frame, and a pulley structure is provided on the pulley bracket. One end of the pulley structure is equipped with a load, and the other end of the pulley structure is connected to the armature end of the torque motor under test through the force sensor. The torque motor under test is placed on the base, and the displacement sensor is located on the base to measure the displacement of the torque motor under test.

[0010] Furthermore, the other end of the pulley structure, the force sensor, and the armature end of the measured torque motor are all connected by a vertical straight line.

[0011] Furthermore, the base is a magnetically conductive base, and the displacement sensor is a laser displacement sensor, which is attached to the magnetically conductive base by an electromagnet.

[0012] Furthermore, the horizontal moving frame can be adjusted relative to the support frame in the X direction and locked with screws, and the support frame can be adjusted relative to the magnetic base in the Z direction and locked with screws; the adjustment in the X and Z directions is used to ensure that the rope at the lower end of the joint bearing is vertical.

[0013] Furthermore, it also includes a linear guide rail, which is mounted on the side of the horizontal moving frame. A force sensor is mounted on the linear guide rail and can move up and down relative to the horizontal moving frame along the linear guide rail.

[0014] Furthermore, it also includes armature extension plates. Two armature extension plates are respectively installed on the end faces of the armature at both ends of the torque motor being measured, and are fixed together with the armature. The armature extension plates are machined with clamping thread holes and triangular grooves. The armature extension plates provide force application points and displacement measurement points. A laser displacement sensor measures the displacement of one armature extension plate, and a pulley structure connects the other armature extension plate.

[0015] A method for measuring the current torque coefficient and magnetic stiffness of a torque motor, using a torque motor current torque coefficient and magnetic stiffness measurement system as described above, comprising:

[0016] Step 1: No current is applied to the torque motor. A load is selected to apply a vertical force to one end of the armature of the torque motor under test. The magnitude of the force is obtained by a force sensor, and the displacement of the torque motor is obtained by a displacement sensor. By changing the weight of the applied load, the force-displacement curve k1 is obtained.

[0017] Step 2: Fix the load, energize the torque motor, and measure the displacement of the torque motor using a displacement sensor to obtain the current-displacement curve k2.

[0018] Step 3: Calculate the current torque coefficient kt and magnetic stiffness km of the torque motor using the force-displacement curve k1 and the current-displacement curve k2.

[0019] Furthermore, specifically, the calculation formulas for the torque motor current torque coefficient kt and the torque motor magnetic stiffness km are as follows:

[0020]

[0021] k m =k a -k1L F L x (2)

[0022] In the formula, L FL is the distance from the point where the force is applied to the center of rotation of the armature. x k is the distance from the armature displacement measurement point to the armature rotation center, in meters. a The stiffness of the Bourdon tube is k, which is an internal structure of a torque motor. a The value is provided by the torque motor manufacturer.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. The system designed in this invention is simple and reliable. The system and method of this invention can measure the current torque coefficient and magnetic stiffness of various types of torque motors, and have good versatility.

[0025] 2. The system design of the present invention is stable, and the designed linear guide rail and other structures ensure the perpendicularity of the force applied to the armature of the torque motor.

[0026] 3. The armature extension piece designed in this invention makes measurement simpler and easier, and also makes the installation of the force application point easier. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this invention, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the measurement system for the torque motor current torque coefficient and magnetic stiffness of the present invention;

[0029] Figure 2 yes Figure 1 Side view;

[0030] Figure 3 This is a structural diagram of the torque motor to be measured according to the present invention;

[0031] Figure 4 This is a schematic diagram of the armature extension piece of the present invention;

[0032] Wherein: 1—magnetic base, 2—mounting seat, 3—support frame, 4—horizontal moving frame, 5—pulley positioning pin, 6—fixed pulley, 7—pulley bracket, 8—linear guide rail, 9—rope, 10—force sensor, 11—joint bearing, 12—torque motor under test, 13—laser displacement sensor, 14—upper magnetic conductor, 15—armature extension piece, 16—armature, 17—lower magnetic conductor. Detailed Implementation

[0033] This section describes embodiments of the present invention, used to explain and illustrate the technical solutions of the present invention. Unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0034] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating directions or positional relationships, are given in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or device referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include more than one of those features. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integrated connection; they can refer to a mechanical connection or a point connection; they can refer to a direct connection or a connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] A measurement system for the current torque coefficient and magnetic stiffness of a torque motor includes a base, a support frame 3, a horizontally movable frame 4, a pulley bracket 7, a force sensor 10, and a displacement sensor. The support frame 3 is mounted on the base, and the horizontally movable frame 4, which can move horizontally relative to the support frame 3, is mounted on the support frame 3. The pulley bracket 7 is mounted on the top of the horizontally movable frame 4, and the pulley bracket 7 is provided with a pulley structure. One end of the pulley structure is suspended from the load, and the other end of the pulley structure is connected to the armature end of the torque motor 12 under test through the force sensor 10. The torque motor 12 under test is placed on the base, and the displacement sensor is located on the base to measure the displacement of the torque motor 12 under test.

[0037] The other end of the pulley structure, the force sensor 10, and the armature end of the measured torque motor 12 are connected by a vertical straight line.

[0038] The base is a magnetic base 1, and the displacement sensor is a laser displacement sensor 13. The laser displacement sensor 13 is attached to the magnetic base 1 by an electromagnet.

[0039] The horizontal moving frame 4 can be adjusted relative to the support frame 3 in the X direction and locked with screws, and the support frame 3 can be adjusted relative to the magnetic base 1 in the Z direction and locked with screws; the adjustment in the X and Z directions is used to ensure that the rope at the lower end of the joint bearing is vertical.

[0040] It also includes a linear guide rail 8, which is mounted on the side of the horizontal moving frame 4. The force sensor 10 is mounted on the linear guide rail 8 and can move up and down relative to the horizontal moving frame 4 along the linear guide rail 8.

[0041] It also includes armature extension plates 15. Two armature extension plates 15 are respectively installed on the end faces of the armature at both ends of the torque motor 12 being measured, and are fixed together with the armature. The armature extension plates 15 are machined with clamping threaded holes and triangular grooves. The armature extension plates 15 provide force application points and displacement measurement points. The laser displacement sensor 13 measures the displacement of one armature extension plate 15, and the pulley structure connects the other armature extension plate 15.

[0042] A method for measuring the current torque coefficient and magnetic stiffness of a torque motor, using a torque motor current torque coefficient and magnetic stiffness measurement system as described above, comprising:

[0043] Step 1: No current is applied to the torque motor. A load is selected to apply a vertical force to one end of the armature of the torque motor under test. The magnitude of the force is obtained by a force sensor, and the displacement of the torque motor is obtained by a displacement sensor. By changing the weight of the applied load, the force-displacement curve k1 is obtained.

[0044] Step 2: Fix the load, energize the torque motor, and measure the displacement of the torque motor using a displacement sensor to obtain the current-displacement curve k2.

[0045] Step 3: Calculate the current torque coefficient kt and magnetic stiffness km of the torque motor using the force-displacement curve k1 and the current-displacement curve k2.

[0046] Specifically, the formulas for calculating the torque coefficient kt and the magnetic stiffness km of the torque motor are as follows:

[0047]

[0048] k m =k a -k1L F L x (2)

[0049] In the formula, L F L is the distance from the point where the force is applied to the center of rotation of the armature. x k is the distance from the armature displacement measurement point to the armature rotation center, in meters. aThe stiffness of the Bourdon tube is k, which is an internal structure of a torque motor. a The value is provided by the torque motor manufacturer.

[0050] The following is another embodiment of the present invention.

[0051] A measurement system and method for the torque coefficient and magnetic stiffness of a torque motor, comprising a measurement system and a measurement method; the measurement system comprises: a magnetic base 1, a mounting base 2, a support frame 3, a horizontal moving frame 4, a pulley positioning pin 5, a fixed pulley 6, a pulley bracket 7, a linear guide rail 8, a rope 9, a force sensor 10, a joint bearing 11, a torque motor under test 12, a laser displacement sensor 13, and an armature extension plate 15.

[0052] The magnetic base 1, mounting base 2, support frame 3, horizontal moving frame 4, and pulley bracket 7 are fastened together with screws. The torque motor 12 being measured is mounted on the mounting base 2 with screws. Two fixed pulleys 6 are mounted on the horizontal moving frame 4 with pulley positioning pins. The weight is connected to the force sensor 10 through a rope 9. A joint bearing is installed at the lower end of the force sensor 10. The laser displacement sensor 13 is attracted to the magnetic base 1 by an electromagnet.

[0053] The horizontal moving frame 4 can be adjusted relative to the support frame 3 in the X direction and locked with screws. The support frame 3 can be adjusted relative to the magnetic base 1 in the Z direction and locked with screws. The adjustment in the X and Z directions is used to ensure that the rope at the lower end of the joint bearing is vertical.

[0054] The armature extension plate 15 is installed on the end face of the armature of the torque motor 12 being measured and is fixed to the armature as a whole. The armature extension plate 15 is machined with clamping threaded holes and triangular grooves. The function of the armature extension plate is to provide the force application point and the displacement measurement point.

[0055] Force sensor 10 is mounted on linear guide rail 8, which is fixed to horizontal moving frame 4 by screws. Force sensor can only move up and down along linear guide rail, which improves the stability of measurement system.

[0056] The measurement method using the above system is as follows:

[0057] 1. When no current is applied to the torque motor, the weight applies force to one end of the armature of the torque motor 12 being measured through the rope. The magnitude of the applied force is obtained by the force sensor 10. The laser displacement sensor 10 detects and records the displacement of one end of the armature during the measurement process. By changing the applied force value, a force-displacement curve is obtained. The slope of the curve is recorded as k1, and the unit is N / μm.

[0058] 2. Given a fixed load, apply a series of current values ​​to the torque motor, measure the armature displacement in response, and obtain a current-displacement curve. The slope of the curve is denoted as k2, and the unit is A / μm.

[0059] 3. Torque coefficient k of torque motor current t And torque motor magnetic stiffness k m The calculation formulas are respectively

[0060]

[0061] k m =k a -k1L F L x (2)

[0062] In the formula, L F L is the distance from the point where the force is applied to the center of rotation of the armature, expressed in meters (m). x is the distance from the armature displacement measurement point to the armature rotation center, in meters; ka is the spring tube stiffness, in N·m / rad.

[0063] The above description of the embodiments is provided to enable those skilled in the art to understand and apply the present invention. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the embodiments described herein, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A system for measuring the current torque coefficient and magnetic stiffness of a torque motor, characterized in that, The system includes a base, a support frame (3), a horizontal moving frame (4), a pulley bracket (7), a force sensor (10), and a displacement sensor. The support frame (3) is mounted on the base, and the horizontal moving frame (4) is mounted on the support frame (3) and can move horizontally relative to the support frame (3). The pulley bracket (7) is mounted on the top of the horizontal moving frame (4), and the pulley bracket (7) is provided with a pulley structure. One end of the pulley structure is used to suspend the load, and the other end of the pulley structure is connected to the armature end of the torque motor (12) being measured through the force sensor (10). The torque motor (12) being measured... The displacement sensor is placed on the base to measure the displacement of the torque motor (12) under test; it also includes an armature extension plate (15), two armature extension plates (15) are respectively installed on the end faces of the armature at both ends of the torque motor (12) under test, and are fixed together with the armature. The armature extension plate (15) is machined with clamping thread holes and triangular grooves; the armature extension plate (15) provides the force application point and displacement measurement point, the laser displacement sensor (13) measures the displacement of one armature extension plate (15), and the pulley structure connects the other armature extension plate (15).

2. The measurement system for the current torque coefficient and magnetic stiffness of a torque motor according to claim 1, characterized in that, The other end of the pulley structure, the force sensor (10), and the armature end of the measured torque motor (12) are a vertical straight line.

3. The measurement system for the current torque coefficient and magnetic stiffness of a torque motor according to claim 2, characterized in that, The base is a magnetic base (1), and the displacement sensor is a laser displacement sensor (13). The laser displacement sensor (13) is attached to the magnetic base (1) by an electromagnet.

4. The measurement system for the current torque coefficient and magnetic stiffness of a torque motor according to claim 3, characterized in that, The horizontal moving frame (4) can be adjusted relative to the support frame (3) in the X direction and locked with screws. The support frame (3) can be adjusted relative to the magnetic base (1) in the Z direction and locked with screws. The force sensor (10) has a joint bearing (11) installed at its lower end. The adjustment in the X and Z directions is used to ensure that the rope at the lower end of the joint bearing is vertical.

5. The measurement system for the current torque coefficient and magnetic stiffness of a torque motor according to claim 4, characterized in that, It also includes a linear guide rail (8), which is mounted on the side of the horizontal moving frame (4), and a force sensor (10) is mounted on the linear guide rail (8) and can move up and down relative to the horizontal moving frame (4) along the linear guide rail (8).

6. A method for measuring the current torque coefficient and magnetic stiffness of a torque motor, using the measurement system for the current torque coefficient and magnetic stiffness of a torque motor as described in any one of claims 1-5, characterized in that, include: Step 1: No current is applied to the torque motor. A load is selected to apply a vertical force to one end of the armature of the torque motor under test. The magnitude of the force is obtained by a force sensor, and the displacement of the torque motor is obtained by a displacement sensor. By changing the weight of the applied load, the force-displacement curve k1 is obtained. Step 2: Fix the load, energize the torque motor, and measure the displacement of the torque motor using a displacement sensor to obtain the current-displacement curve k2. Step 3: Calculate the current torque coefficient k of the torque motor using the force-displacement curve k1 and the current-displacement curve k2. t and magnetic stiffness k m .

7. The method for measuring the current torque coefficient and magnetic stiffness of a torque motor according to claim 6, characterized in that, Torque motor current torque coefficient k t And torque motor magnetic stiffness k m The calculation methods are as follows: （1） （2） In the formula, L F L is the distance from the point where the force is applied to the center of rotation of the armature. x k is the distance from the armature displacement measurement point to the armature rotation center, in meters. a The stiffness of the Bourdon tube is k, which is an internal structure of a torque motor. a The value is provided by the torque motor manufacturer.

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