Full-automatic metering and checking system for surface Rockwell hardness blocks

Abstract

The invention discloses a surface Rockwell hardness block full-automatic metering and checking system which comprises a support used for installing a driving system A, a driving system B, a working platform and a connecting rod. The working platform is used for placing a surface Rockwell hardness block to be calibrated; the upper end of the connecting rod is connected with the displacement measuring sensor, the grating displacement measuring system and the measuring pressure head, and the lower end is connected with the weight tray; the weight tray is used for supporting a standard weight; the plurality of groups of standard weights are supported in the bracket in an up-and-down sliding manner; the weight selection rod is provided with a plurality of weight selection clamping supports and is in driving connection with the driving system B; the driving system A is used for lifting or lowering the weight tray; and the computer is used for setting a hardness calibration point, controlling the movement of the driving system, collecting displacement values measured by the displacement measurement sensor and the grating displacement measurement sensor, and calculating a hardness indication error by combining the displacement values of the displacement measurement sensor and the grating displacement measurement sensor. According to the invention, automatic metering calibration of the surface Rockwell hardness block is realized.

Description

Technical Field

[0001] The invention belongs to the field of hardness block metrology and calibration, in particular to a full-automatic metrology and calibration system for a surface Rockwell hardness block. Background Art

[0002] The surface Rockwell hardness test is widely used in industrial production, scientific experiments, national defense construction, and domestic and foreign trade such as automobiles, tractors, aircraft, instruments, and bearings. The surface Rockwell hardness is one of the important indicators of the mechanical properties of metal materials and product quality. The surface Rockwell hardness test is an important means to check product quality, determine reasonable processing technology, and improve economic benefits.

[0003] Most of the Rockwell hardness testers produced domestically are open-loop systems with weight loading. Although the structure is simple, the loading force will bring about large fluctuations and affect the loading accuracy.

[0004] The development of foreign Rockwell hardness testers was earlier, and there are many manufacturers producing hardness testers. Foreign Rockwell hardness testers mainly adopt closed-loop control, a system where the motor generates power for loading, eliminating the fluctuation of loading caused by weights, hydraulic pressure, etc. However, this type of hardness tester still requires manual selection of weights, cannot achieve automatic measurement and calibration during the measurement process, and is relatively expensive. Summary of the invention

[0005] The purpose of the present invention is to provide a fully automatic measurement and calibration system for a superficial Rockwell hardness block, so as to solve the current measurement and calibration problem of a superficial Rockwell hardness block.

[0006] The technical solution to achieve the purpose of the present invention is:

[0007] A fully automatic measurement and calibration system for surface Rockwell hardness blocks, comprising:

[0008] Bracket, used for installing drive system A, drive system B, working platform and connecting rod;

[0009] The working platform is located below the measuring indenter and is used to place the Rockwell hardness block of the surface to be calibrated;

[0010] A connecting rod, the upper end of which is connected to a displacement measurement sensor, a grating displacement measurement system and a measuring pressure head, and the lower end of which is connected to a weight tray, capable of sliding relatively to the working platform;

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

[0012] Multiple sets of standard weights are supported in the bracket by sliding up and down;

[0013] The weight selection rod is provided with a plurality of weight selection brackets along the height, and the plurality of weight selection brackets are arranged staggered along the circumferential direction, and can be driven by the drive system B to rotate to the lower end of the standard weights at different positions to complete the selection and loading of different quantities of standard weights;

[0014] The driving system A is used to lift or lower the weight tray, realize the loading and separation of the Rockwell hardness block of the calibrated surface by the measuring pressure head, 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 the drive system A and the 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] Compared with the prior art, the present invention has the following significant advantages:

[0017] The present invention realizes automatic metrological calibration of surface Rockwell hardness block; solves the precise loading and unloading of initial test force and main test force in metrological calibration process, ensures that the maximum allowable error of initial test force and main test force meets the technical index requirements; adopts the method of combining displacement optical measurement with sensor measurement, solves the problem of low measurement accuracy of standard hardness tester, realizes accurate measurement of indentation depth, and improves the reliability of measurement results. The calibration process is simple, and the high measurement accuracy greatly improves the efficiency of metrological calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the fully automatic measurement and calibration device for surface Rockwell hardness.

[0019] Figure 2 This is a schematic diagram of the measurement of the fully automatic measurement and calibration device for surface Rockwell hardness. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0021] Combination Figure 1 The present invention provides a fully automatic measurement and calibration system for a surface Rockwell hardness block, comprising 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 pressure head 6, a working platform 7, a weight tray 8, a force sensor 9, a worm 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, a standard weight 17, and a weight selection tray 18;

[0022] The computer 1 and the electrical box 15 are both arranged on the bracket 16. The computer 1 can set the test parameters and control the operation of the servo motor through the electrical box 15. The servo motor A 12 and the servo motor B 13 are both fixed on the bracket 16. The high-precision displacement measurement sensor 2 and the grating displacement measurement system 3 are respectively connected to the computer 1 through data communication lines; the high-precision displacement measurement sensor 2 and the grating displacement measurement system 3 are installed on the connecting rod 5 through a fixed connecting frame; the upper end of the spring 4 is fixed on the connecting rod 5 and is sleeved on the outside of the measuring pressure head 6. In the natural state, the lower end protrudes from the measuring pressure head 6, which is used to buffer the measuring pressure head during testing; the measuring pressure head 6 is installed on the connecting rod 5 through a threaded hole; the working platform 7 is fixed on the bracket 16 and is 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 worm screw 10 and is located below the weight tray 8; a sliding rod is fixed in the bracket 16, and multiple groups of standard weights 17 are connected in series on the sliding rod and the connecting rod 5, and 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 groups of standard weights 17 to support the standard weights 17, and the servo motor A12 is connected to the worm screw 10. In the initial state, the force sensor 9 contacts the weight tray 8 to lift the connecting rod 5, so that the measuring pressure head 6 is in a raised state. The weight selection rod 11 is connected to the servo motor B13, and multiple weight selection trays 18 are arranged along the height. The multiple weight selection trays 18 are staggered along the circumferential direction. The rotation of the servo motor B13 drives the weight selection rod 11 to rotate, and the weight selection trays 18 at different positions can be rotated to the standard weights 17 corresponding to different height layers to select the weights. There are gaps 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 lifted up and do not participate in loading. The bottom of the bracket 16 is provided with multiple adjustable foot cups 14 for leveling.

[0023] During metrological calibration, the Rockwell hardness block 19 of the surface to be calibrated is placed on the working platform 7. Figure 2 According to the requirements for the calibration of the surface Rockwell hardness block, the hardness calibration point m 1 、m 2 ...m n For example, the hardness calibration point m 1 During measurement, the type of Rockwell hardness block 19 of the calibrated surface is first input into computer 1, the magnitude of the test force F is automatically calculated, and the servo motor B13 is used to drive the weight selection rod 11 to rotate so that the weight selection card holder 18 moves to the corresponding position, thereby realizing the selection of the corresponding number of standard weights 17. The standard weights 17 on the corresponding card holder 18 are lifted and do not participate in the loading test. Set the hardness calibration point m on computer 1 1, and controls the rotation of servo motor A12.

[0024] For example, the types of 19 calibrated surface Rockwell hardness blocks include 15N, 30N, 45N, 15T, 30T, and 45T. If it is the 15N type, the required test force is 150N, the 30N test force is 300N, and the 45N test force is 450N.

[0025] At the same time, the measuring system uses the number of pulse signals n to control the servo motor A12 to rotate and drive the worm screw 10 to rotate clockwise, thereby moving the weight tray 8 downward, and the measuring pressure head 6 slowly presses on the surface of the Rockwell hardness block 19 to be calibrated; when the number of pulse signals reaches n, the servo motor A12 stops rotating and keeps rotating for (10-20) seconds, at which time the force sensor 9 displays a force value of FF 初 This state is the initial test force loading state; at this time, the computer 1 collects the displacement measurement values ​​x and x of the grating displacement measurement system 3 through the data communication line. 1 , high-precision displacement measurement sensor 2 measurement value y 1 The maximum allowable error of the measurement results of the two methods is k1. If |x 1 -y 1 |≤k1, then the displacement measurement value is If |x 1 -y 1 |>k1, then discard the measurement result and re-measure. 初 is a constant, and its magnitude is 30N.

[0026] Subsequently, the measuring system uses the number of pulse signals m to continue to control the rotation of the servo motor A12 to drive the worm screw 10 to rotate clockwise, thereby causing the weight tray 8 to continue to move downward, and the measuring pressure head 6 continues to slowly press on the surface of the Rockwell hardness block 19 to be calibrated; when the number of pulse signals reaches m, the servo motor A12 stops rotating and keeps for 15 seconds, at which time the weight tray 8 is completely separated from the force sensor 9, and the value displayed by the force sensor 9 is 0, which is the main test force loading state;

[0027] Then, the measuring system uses the number of pulse signals u to continue to control the servo motor A12 to rotate and drive the worm screw 10 to rotate counterclockwise, thereby moving the weight tray 8 upward, and the measuring pressure head 6 continues to slowly leave the surface of the Rockwell hardness block 19 to be calibrated; when the number of pulse signals reaches u, the servo motor A12 stops rotating and keeps rotating 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, the computer 1 collects the displacement measurement value x of the grating displacement measurement system 3 through the data communication line 2 , high-precision displacement measurement sensor 2 measurement value y 2The maximum allowable error of the measurement results of the two methods is k2. If |x 2 -y 2 |≤k2, then the displacement measurement value is If |x 2 -y 2 |>k2, the measurement result is discarded and the measurement is repeated.

[0028] Finally, the measuring system uses the pulse signal number v to continue to control the servo motor A12 to rotate and drive the worm screw 10 to rotate counterclockwise, so that the weight tray 8 continues to move upward, and the measuring pressure head 6 continues to slowly leave the surface of the Rockwell hardness block 19 to be calibrated; when the pulse signal number reaches v, the servo motor A12 stops rotating and returns to the initial position. At this time, the force sensor 9 displays the force value 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), hardness indication error d 1 =j 1 -m 1 ;

[0029] The same method is used to complete the remaining hardness calibration point indication error d 2 ,d 3 ...d n This method combines displacement optical measurement with sensor measurement and has the characteristics of high measurement accuracy and simple algorithm to meet the requirements of tachometer measurement and calibration.

Claims

1. A fully automatic measurement and calibration system for surface Rockwell hardness blocks, characterized in that: include: Bracket, used for installing drive system A, drive system B, working platform and connecting rod; The working platform is located below the measuring indenter and is used to place the Rockwell hardness block of the surface to be calibrated; A connecting rod, the upper end of which is connected to a displacement measurement sensor, a grating displacement measurement system and a measuring pressure head, and the lower end of which is connected to a weight tray, capable of sliding relatively to the working platform; Weight tray, used to support standard weights; Multiple sets of standard weights are supported in the bracket by sliding up and down; The weight selection rod is provided with a plurality of weight selection brackets along the height, and the plurality of weight selection brackets are arranged staggered along the circumferential direction, and can be driven by the drive system B to rotate to the lower end of the standard weights at different positions to complete the selection and loading of different quantities of standard weights; The driving system A is used to lift or lower the weight tray, realize the loading and separation of the Rockwell hardness block of the calibrated surface by the measuring pressure head, 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 the drive system A and the 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.

2. The fully automatic measurement and calibration system for surface Rockwell hardness blocks according to claim 1 is characterized in that: The process of calculating the hardness indication error by the computer is as follows: According to the type of Rockwell hardness block of the surface to be calibrated, the test force is calculated, and the drive system B is controlled to drive the weight selection rod to rotate to rotate the standard weight; Set the hardness calibration point, control the drive system A to drive the weight tray to move, and perform tests in 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 the initial test force loading state, the displacement measurement value at this time is obtained according to the displacement values ​​of the two; In the state of unloading the main test force, the displacement measurement value at this time is obtained according to the displacement values ​​of the two; The hardness value is obtained by combining the displacement measurement values ​​in 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.

3. The fully automatic measurement and calibration system for surface Rockwell hardness blocks according to claim 2 is characterized in that: The hardness indication error is: d1=j1-m1; Where m1 is the hardness calibration point value; h is a constant; j1 is the hardness measurement value: z2 and z1 are the displacement measurement values ​​in the main test force unloading state and the initial test force loading state respectively: x2 and y2 are the displacement measurement values ​​of the grating displacement measurement system and the displacement measurement sensor when the main test force is unloaded, respectively, satisfying: |x2-y2|≤k2, k2 is the maximum allowable error of the two measurement values ​​at this time; x1 and y1 are the displacement measurement values ​​of the grating displacement measurement system and the displacement measurement sensor when the initial test force is loaded, respectively; satisfying |x1-y1|≤k1, k1 is the maximum allowable error of the two measurement values ​​at this time.

4. The fully automatic measurement and calibration system for surface Rockwell hardness blocks according to claim 1 is characterized in that: The driving system A comprises a servo motor A and a worm screw; the servo motor A is connected to the worm screw, and the force sensor is connected to the nut of the worm screw.

5. The fully automatic measurement and calibration system for surface Rockwell hardness blocks according to claim 4 is characterized in that: The number of pulse signals is used to control the rotation of servo motor A to drive the turbine screw to rotate, thereby moving the weight tray.

6. The fully automatic measurement and calibration system for surface Rockwell hardness blocks according to claim 1 is characterized in that: The driving system B comprises a servo motor B, which is connected to a weight selection rod.

7. The fully automatic measurement and calibration system for surface Rockwell hardness blocks according to claim 1 is characterized in that: A plurality of adjustable foot cups are arranged at the bottom of the bracket for leveling.

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

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