A full-automatic metering and calibration system for surface rockwell hardness blocks

Abstract

The application discloses a kind of surface Rockwell hardness block full-automatic metering calibration systems, comprising: support, for installing driving system A, driving system B, work platform and connecting rod;Work platform is used to place the surface Rockwell hardness block of being calibrated;Connecting rod, upper end connects displacement measuring sensor, grating displacement measuring system and measuring pressure head, lower end connects weight tray;Weight tray is used to support standard weight;Multiple standard weights are supported in support and slide up and down;Weight selection rod is equipped with multiple weight selection card holders, and is connected with driving system B drive;Driving system A is used to lift or lower weight tray;Computer is used to set hardness calibration point, and control the movement of driving system, collect the displacement value measured by displacement measuring sensor, grating displacement measuring, and the displacement value of two combinations calculates hardness indication error.The application realizes the automatic metering calibration of surface Rockwell hardness block.

Description

Technical Field

[0001] This invention belongs to the field of hardness block metrology and calibration, and in particular, it is a fully automatic metrology and calibration system for surface Rockwell hardness blocks. Background Technology

[0002] Surface Rockwell hardness testing is widely used in industrial production, scientific research, national defense, and domestic and international trade, including automobiles, tractors, aircraft, instruments, and bearings. Surface Rockwell hardness is one of the important indicators of the mechanical properties of metallic materials and product quality. It is a crucial means of checking product quality, determining appropriate processing techniques, and improving economic efficiency.

[0003] Most domestically produced Rockwell hardness testers are open-loop systems with weight loading. Although the structure is simple, the loading force can cause large fluctuations, which affects the loading accuracy.

[0004] Rockwell hardness testers were developed earlier abroad, and there are many manufacturers producing them. Foreign Rockwell hardness testers mainly use a closed-loop control system, with a motor-driven loading mechanism, eliminating the fluctuations caused by weights and hydraulic pressure. However, these hardness testers still require manual weight selection, cannot achieve automatic calibration during the measurement process, and are relatively expensive. Summary of the Invention

[0005] The purpose of this invention is to provide a fully automated metrological calibration system for surface Rockwell hardness blocks to solve the current metrological calibration problem of surface Rockwell hardness blocks.

[0006] The technical solution to achieve the purpose of this invention is as follows:

[0007] A fully automated metrological calibration system for surface Rockwell hardness blocks includes:

[0008] The bracket is used to mount drive system A, drive system B, work platform, and connecting rods.

[0009] The working platform, located below the measuring indenter, is used to place the Rockwell hardness block on the surface to be inspected;

[0010] The connecting rod connects to the displacement measurement sensor, the grating displacement measurement system and the measuring pressure head at the upper end, and to the weight tray at the lower end, allowing it to slide relative to the working platform.

[0011] Weight tray, used to support standard weights;

[0012] Multiple sets of standard weights slide up and down within the support frame;

[0013] The weight selection rod has multiple weight selection trays along its height. These multiple weight selection trays are staggered circumferentially and can rotate to the lower end of the standard weights at different positions under the drive of the drive system B, so as to complete the selection and loading of different numbers of standard weights.

[0014] Drive system A is used to raise or lower the weight tray to realize the loading and separation of the measuring indenter on the Rockwell hardness block of the surface being tested, realize the switching of the detection state, and is equipped with a force sensor to display the detection state through the display value, which includes the initial test force loading state, the main test force loading state, the main test force unloading state, and the initial test force unloading state in sequence.

[0015] The computer is used to set the hardness calibration point, control the movement of drive system A and drive system B, collect the displacement values ​​measured by the displacement measurement sensor and the grating displacement measurement, and calculate the hardness indication error by combining the displacement values ​​of the two.

[0016] The significant advantages of this invention compared to existing technologies are:

[0017] This invention enables automatic metrological calibration of surface Rockwell hardness blocks; it solves the problem of precise loading and unloading of initial and main test forces during metrological calibration, ensuring that the maximum permissible error of the initial and main test forces meets technical specifications; by combining displacement optical measurement and sensor measurement, it solves the problem of low measurement accuracy of standard hardness testers, achieving accurate measurement of indentation depth and improving the reliability of measurement results. The calibration process is simple, and the high measurement accuracy greatly improves the efficiency of metrological calibration. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a fully automated surface Rockwell hardness measurement and calibration device.

[0019] Figure 2 This is a schematic diagram of a fully automated surface Rockwell hardness measurement and calibration device. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0021] Combination Figure 1 This embodiment of a fully automatic metrological calibration system for surface Rockwell hardness blocks includes a computer 1, a high-precision displacement measurement sensor 2, a grating displacement measurement system 3, a spring 4, a connecting rod 5, a measuring indenter 6, a working platform 7, a weight tray 8, a force sensor 9, a worm gear screw 10, a weight selection rod 11, a servo motor A 12, a servo motor B 13, an adjustable foot cup 14, an electrical box 15, a bracket 16, standard weights 17, and a weight selection tray 18.

[0022] The computer 1 and electrical box 15 are both mounted on the bracket 16. The computer 1 can set test parameters and control the operation of the servo motors through the electrical box 15. Servo motors A 12 and B 13 are both fixed on the bracket 16. The high-precision displacement measurement sensor 2 and the grating displacement measurement system 3 are connected to the computer 1 via data communication lines. The high-precision displacement measurement sensor 2 and the grating displacement measurement system 3 are mounted on the connecting rod 5 via a fixed connecting bracket. The upper end of the spring 4 is fixed on the connecting rod 5 and sleeved on the outside of the measuring pressure head 6. In its natural state, the lower end protrudes from the measuring pressure head 6 to buffer the measuring pressure head during testing. The measuring pressure head 6 is mounted on the connecting rod 5 through a threaded hole. The working platform 7 is fixed on the bracket 16 and located below the measuring pressure head 6, and is used to place the Rockwell hardness block of the surface to be calibrated. 19; The connecting rod 5 can slide up and down along the working platform 7; The weight tray 8 is connected to the lower end of the connecting rod 5; The force sensor 9 is connected to the nut of the turbine screw 10 and is located below the weight tray 8; A sliding rod is fixed inside the bracket 16, and multiple sets of standard weights 17 are connected in series on the sliding rod and the connecting rod 5, which can move up and down along the sliding rod and the connecting rod 5, but cannot fall off; The weight tray 8 is located at the bottom of the multiple sets of standard weights 17 to support the standard weights 17; The servo motor A12 is connected to the turbine screw 10. In the initial state, the force sensor 9 is in contact with the weight tray 8, which lifts the connecting rod 5, so that the measuring pressure head 6 is in an elevated state. The weight selection lever 11 is connected to the servo motor B13. Multiple weight selection trays 18 are arranged circumferentially staggered along the height. The rotation of the servo motor B13 drives the weight selection lever 11 to rotate, allowing the weight selection trays 18 at different positions to be rotated to the corresponding standard weights 17 at different height levels for weight selection. Gaps are provided between the standard weights 17 to facilitate the insertion of the weight selection trays 18. The standard weights 17 on the weight selection trays 18 are supported and do not participate in the loading process. The bottom of the support 16 is equipped with multiple adjustable feet 14 for leveling.

[0023] During metrological calibration, the Rockwell hardness block 19 on the surface to be calibrated is placed on the work platform 7, such as... Figure 2 As shown. According to the metrological calibration requirements for surface Rockwell hardness blocks, the hardness calibration points m1, m2...m... need to be... n Measurements are performed. For example, when measuring hardness calibration point m1, the type of Rockwell hardness block 19 on the surface to be calibrated is first input into computer 1. The computer automatically calculates the magnitude of the test force F and uses servo motor B13 to drive the weight selection lever 11 to rotate, moving the weight selection tray 18 to the corresponding position. This allows the selection of the corresponding number of standard weights 17. The standard weights 17 on the corresponding tray 18 are lifted but do not participate in the loading test. The hardness calibration point m1 is set on computer 1, and the rotation of servo motor A12 is controlled.

[0024] For example, the Rockwell hardness blocks of type 19 that are being tested include 15N, 30N, 45N, 15T, 30T, and 45T. If it is type 15N, the required test force is 150N; for type 30N, the test force is 300N; and for type 45N, the test force is 450N.

[0025] Simultaneously, the measurement system uses the number of pulse signals n to control the rotation of the servo motor A12, which drives the worm screw 10 to rotate clockwise, thereby causing the weight tray 8 to move downwards. The measuring indenter 6 slowly presses onto the surface of the Rockwell hardness block 19 being inspected. When the number of pulse signals reaches n, the servo motor A12 stops rotating and remains for (10-20) seconds. At this time, the force sensor 9 displays a force value of FF. 初 This state represents the initial test force loading state. At this time, computer 1 collects the displacement measurement value x1 from the grating displacement measurement system 3 and the measurement value y1 from the high-precision displacement measurement sensor 2 via the data communication line. The maximum permissible error between the two measurement methods is k1. If |x1-y1|≤k1, then the displacement measurement value at this time is... If |x1-y1|>k1, then discard the measurement result and repeat the measurement. 初 It is a constant with a value of 30N.

[0026] Subsequently, the measurement system continues to control the servo motor A12 to rotate using the number of pulse signals m, which drives the worm screw 10 to rotate clockwise, thereby causing the weight tray 8 to continue to move downwards, and the measuring indenter 6 to continue to press slowly on the surface of the Rockwell hardness block 19 being inspected; when the number of pulse signals reaches m, the servo motor A12 stops rotating and remains for 15 seconds. At this time, the weight tray 8 is completely separated from the force sensor 9, and the force sensor 9 displays a value of 0. This state is the main test force loading state.

[0027] Next, the measurement system continues to control the servo motor A12 to rotate using the number of pulse signals u, driving the worm screw 10 to rotate counterclockwise, thereby moving the weight tray 8 upwards, and the measuring indenter 6 continues to slowly move away from the surface of the Rockwell hardness block 19 being inspected; when the number of pulse signals reaches u, the servo motor A12 stops rotating and remains for (10~20) seconds, at which time the force sensor 9 displays a force value of F. 主， This state is the main test force unloading state. At this time, computer 1 collects the displacement measurement value x2 from grating displacement measurement system 3 and the measurement value y2 from high-precision displacement measurement sensor 2 via data communication line. The maximum permissible error of the two measurement results is k2. If |x2-y2|≤k2, then the displacement measurement value at this time is... If |x2-y2|>k2, then discard the measurement result and repeat the measurement.

[0028] Finally, the measurement system continues to control the servo motor A12 to rotate using the pulse signal quantity v, driving the worm screw 10 to rotate counterclockwise, thereby causing the weight tray 8 to continue moving upwards, and the measuring indenter 6 to continue slowly leaving the surface of the Rockwell hardness block 19 being inspected. When the pulse signal quantity reaches v, the servo motor A12 stops rotating and the device returns to its initial position. At this time, the force sensor 9 displays a force value of F, which is the initial test force unloading state. The computer automatically calculates the corresponding hardness value. (h is a constant: the value is 100), the hardness indication error is d1 = j1 - m1;

[0029] The remaining hardness calibration point indication errors d2, d3...d were completed using the same method. n The method combines displacement optical measurement with sensor measurement, which has the characteristics of high measurement accuracy and simple algorithm, and meets the requirements of tachometer calibration.

Claims

1. A fully automated metrological calibration system for surface Rockwell hardness blocks, characterized in that, include: The bracket is used to mount drive system A, drive system B, work platform, and connecting rods. The working platform, located below the measuring indenter, is used to place the Rockwell hardness block on the surface to be inspected; The connecting rod connects to the displacement measurement sensor, the grating displacement measurement system and the measuring pressure head at the upper end, and to the weight tray at the lower end, allowing it to slide relative to the working platform. Weight tray, used to support standard weights; Multiple sets of standard weights slide up and down within the support frame; The weight selection rod has multiple weight selection trays along its height. These multiple weight selection trays are staggered circumferentially and can rotate to the lower end of the standard weights at different positions under the drive of the drive system B, so as to complete the selection and loading of different numbers of standard weights. Drive system A is used to raise or lower the weight tray to realize the loading and separation of the measuring indenter on the Rockwell hardness block of the surface being tested, realize the switching of the detection state, and is equipped with a force sensor to display the detection state through the display value, which includes the initial test force loading state, the main test force loading state, the main test force unloading state, and the initial test force unloading state in sequence. The computer is used to set the hardness calibration point, control the movement of drive system A and drive system B, collect the displacement values ​​measured by the displacement measurement sensor and the grating displacement measurement, and calculate the hardness indication error by combining the displacement values ​​of the two. The process by which the computer calculates the error in the hardness indication is as follows: Based on the type of Rockwell hardness block on the surface being tested, the magnitude of the test force is calculated, and the drive system B is controlled to rotate the weight selection rod to rotate the standard weight. Set hardness calibration points, control drive system A to move the weight tray and perform tests on the initial test force loading state, the main test force loading state, the main test force unloading state and the initial test force unloading state; Under the initial test force loading state, the displacement measurement value at this time is obtained based on the displacement values ​​of both. Under the condition of unloading the main test force, the displacement measurement value at this time is obtained based on the displacement values ​​of the two. The hardness value is obtained by combining the displacement measurements under the initial test force loading state and the main test force unloading state, and the hardness value is compared with the hardness calibration point value to obtain the hardness indication error. The hardness indication error is: d1 = j1 - m1; Where m1 is the hardness calibration point value; h is a constant; j1 is the measured hardness value: z2 and z1 are the displacement measurements under the main test force unloading state and the initial test force loading state, respectively: x2 and y2 are the displacement measurements of the grating displacement measurement system and the displacement measurement sensor under the main test force unloading state, respectively, satisfying: |x2-y2|≤k2, where k2 is the maximum permissible error of the two measurements at this time; x1 and y1 are the displacement measurements of the grating displacement measurement system and the displacement measurement sensor under the initial test force loading state, respectively, satisfying |x1-y1|≤k1, where k1 is the maximum permissible error of the two measurements at this time.

2. The fully automatic metrological calibration system for surface Rockwell hardness blocks according to claim 1, characterized in that, The drive system A includes a servo motor A and a turbine lead screw; the servo motor A is connected to the turbine lead screw, and the force sensor is connected to the nut of the turbine lead screw.

3. The fully automatic metrological calibration system for surface Rockwell hardness blocks according to claim 2, characterized in that, The number of pulse signals is used to control the rotation of servo motor A, which drives the worm screw to rotate, thereby moving the weight tray.

4. The fully automatic metrological calibration system for surface Rockwell hardness blocks according to claim 1, characterized in that, The drive system B includes a servo motor B, which is connected to a weight selection lever.

5. The fully automatic metrological calibration system for surface Rockwell hardness blocks according to claim 1, characterized in that, The support base is equipped with multiple adjustable feet for leveling.

6. The fully automatic metrological calibration system for surface Rockwell hardness blocks according to claim 1, characterized in that, A spring is provided on the outside of the measuring pressure head, and the upper end of the spring is fixed to the connecting rod.

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