A hardness tester indentation depth measuring device and a hardness tester using the same

Abstract

A hardness tester indentation depth measuring device and a hardness tester using the device belong to the technical field of hardness testing, overcome the problem that the existing technology indentation depth measurement adopts active device, the circuit structure is complex and the energy consumption is large, characterized in that a screw rod, a multi-contact top rod and a reset hair are installed in the inside of the measuring part shell, a permanent magnet is installed on the screw rod, a magnetic field angle sensing unit is installed on the first circuit board, the measuring part shell is installed on the raised part of the upper end of the pressure needle sleeve, the upper surface of the gland is in contact with the force handle, the axial convex bottom surface of the multi-contact top rod is in contact with the top surface of the pressure needle, the magnetic field angle sensing unit obtains the rotation angle of the screw rod according to the change of the magnetic force line angle, calculates the indentation depth according to the screw angle, and further calculates the hardness value, the beneficial effect is that the excitation end is a passive device permanent magnet, and high-frequency oscillation circuit is not needed to excite, so that the circuit structure is simple, more energy-saving and lower in cost.

Description

Technical Field

[0001] This utility model belongs to the field of hardness testing technology, and specifically relates to a hardness tester indentation depth measuring device and a hardness tester using the device. Background Technology

[0002] As early as April 17, 1929, American Rawebster filed a patent application for hardness testers, and in 1932 founded Webster Instrument, Inc. Hardness testers began to enter my country in the 1980s with the introduction of aluminum profile production lines.

[0003] In 2000, the applicant (formerly Shenyang Tianxing Measurement and Control Technology Research Institute) and the South China Product Quality Supervision and Inspection Center of China Nonferrous Metals Industry were responsible for drafting the "Standard for Webster Hardness Test Method of Aluminum Alloys"—the "Standard of the People's Republic of China Nonferrous Metals Industry" (YS / T 420-2000). According to records found at https: / / baike.baidu.com / item / regarding Webster hardness testers, the principle of the Webster hardness tester is to use a hard steel indenter of a specific shape, pressed into the sample surface under the action of a standard spring test force. The hardness of the material is determined by the depth of indentation, with 0.01 mm defined as one Webster hardness unit. In existing technology, the Webster hardness tester consists of three main components: a frame, a handle, and an indenter assembly. The indenter assembly includes the indenter, a load spring, an adjusting nut, an indenter sleeve, a reset button, a reset spring, and a dial indicator. When the handle is pressed down, the indenter assembly moves as a whole towards the anvil. The Webster hardness tester is a small, portable instrument. Its small size, light weight, and single-handed operation allow for quick, convenient, and non-destructive testing of material hardness. It eliminates the need for sampling and requires minimal operational skills, making it ideal for rapid hardness testing on production sites. However, the clamp-type Webster hardness tester used in the metal profile industry suffers from instability due to manual force application. In particular, current technology uses a dial to display the indentation depth, with the pointer rotating as the indenter's tip penetrates. Since the dial's readings can only be estimated, the measurement accuracy is poor.

[0004] Patent application CN201110419852.0 (authorization publication number CN102494964B) discloses an "electric Webster hardness tester." This invention includes a control system, a power actuator, and a probe device. The control system connects to and drives the power actuator, which in turn connects to and drives the probe device to perform contact pressure hardness testing on a workpiece placed on an anvil. The invention indicates that the display device can be a mechanical display or an electronic digital display, but does not specify the structure of the electronic digital display. Furthermore, the power actuator mainly includes a screw housed in a carriage. The lower end of the screw is connected to the power output shaft of a micro-motor via an eccentric shaft. The screw is hinged to the eccentric shaft via a slider and a connecting rod. The slider is threaded onto the screw. A fixed slider is provided at the lower end of the screw, and a connecting rod or wire rope is mounted on the fixed slider. This connecting rod or wire rope is connected to the power output shaft of the micro-motor via a through-spindle. Therefore, the invention has a complex structure and consumes a lot of energy. Moreover, the screw in the device is used to apply test force to the indenter and cannot be used to measure the depth of the indentation.

[0005] Patent application CN202410534672.4 (publication number CN118464687A) provides a "hardness tester and hardness measurement method". The hardness tester includes a force-applying component, an indenter, a test piece, a detector, and a detection circuit board. The force-applying component applies pressure to the indenter along a first direction. The first end of the indenter presses against the test piece, and the test piece is connected to the second end of the indenter. The detector is spaced apart from the test piece along the first direction and is used to detect the test piece. The detection circuit board is electrically connected to the detector and is used to calculate a first distance between the test piece and the detector based on the detector's detection information, and to calculate the hardness of the test piece based on the first distance. Further analysis of the specific embodiments in the invention specification reveals that the test piece is an eddy current sensing substrate, the detector is an eddy current sensor, and the detection circuit board includes a high-frequency oscillation circuit for generating a high-frequency alternating current. A high-frequency oscillation circuit generates a high-frequency alternating current, which is transmitted to an eddy current sensor. The eddy current sensor generates a high-frequency alternating electromagnetic field, which induces eddy currents in the eddy current sensing substrate and provides feedback to the eddy current sensor. The specification also indicates that the detected object can be a magnetic induction substrate, and the detector is a magnetic induction sensor. The detection circuit board includes a high-frequency oscillation circuit for generating the high-frequency alternating current. The magnetic induction sensor includes a magnetic induction coil. The high-frequency oscillation circuit generates a high-frequency alternating current, which is transmitted to the magnetic induction coil. The magnetic induction coil emits an alternating magnetic field, which, together with the magnetic induction substrate, forms a closed magnetic circuit. The closed magnetic circuit changes the alternating magnetic field. Due to the distance between the magnetic induction substrate and the magnetic induction coil, the magnetic reluctance of the magnetic circuit changes, resulting in a change in magnetic flux. The detection circuit calculates the distance between the magnetic induction substrate and the magnetic induction coil by measuring the magnetic flux and finding the corresponding curve of distance versus magnetic flux. Optionally, the magnetic induction substrate can be a magnetic metal material, such as iron or stainless steel. Both of the above-described embodiments illustrate that this invention is an active device, highly susceptible to temperature fluctuations and exhibiting relatively poor reliability. In practical applications, eddy current sensors or magnetic induction sensors have different temperature sensitivity coefficients when measuring different displacements. To achieve accurate measurement, this invention requires temperature compensation. Therefore, this invention obtains the temperature of the eddy current sensor or magnetic induction sensor through a temperature sensor, and then performs temperature compensation on the measured oscillation frequency based on the known temperature characteristic curve. To reduce the influence of the temperature sensor on the detector, the detector is surrounded by the temperature sensor, and an insulating thermally conductive material is connected between the temperature sensor and the detector. These technical measures are necessary for this invention, resulting in a relatively complex circuit structure and higher energy consumption. Utility Model Content

[0006] The problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a hardness tester indentation depth measuring device with simple circuit structure, passive components, no temperature influence, low energy consumption and high reliability.

[0007] The technical solution adopted by this utility model includes a pressure cap, a measuring part housing, and a first circuit board. The measuring part housing is a stepped cylinder in shape. Inside the measuring part housing, there is a spiral rod mounting hole parallel to the center line of the stepped cylinder and a multi-contact top rod mounting hole connected to the spiral rod mounting hole. A spiral rod is installed in the spiral rod mounting hole, and a multi-contact top rod is installed in the multi-contact top rod mounting hole. The multi-contact top rod has an axial protrusion at the bottom that contacts the top surface of the hardness tester indenter during use. The multi-contact top rod has a radial protrusion at the middle position. The upper right end of the radial protrusion of the top rod contacts and connects with the upper spiral surface of the spiral rod. A reset spring is also installed in the spiral rod mounting hole. A permanent magnet is installed on the spiral rod in the spiral rod mounting hole. A magnetic field angle sensing unit is installed on the first circuit board.

[0008] A top bearing is installed in the mounting hole of the screw rod. Both the measuring part housing and the top bearing are made of non-magnetic materials. Magnetic lines of force can pass through the measuring part housing and the top bearing and be sensed by the magnetic field angle sensing unit. When the permanent magnet rotates under the drive of the screw rod, the angle of the magnetic lines of force changes. The magnetic field angle sensing unit obtains the rotation angle of the screw rod based on the change in the angle of the magnetic lines of force. Then, based on the helix angle of the upper helical surface of the screw rod, it calculates the distance that the multi-contact push rod moves parallel to the vertical axis in the mounting hole of the multi-contact push rod. That is, it calculates the distance between the bottom surface of the indenter and the bottom surface of the indenter sleeve of the hardness tester based on the helix angle. This distance is the indentation depth. The hardness value is then calculated based on the indentation depth.

[0009] An energy-saving switch is also installed on the first circuit board. Inside the housing of the measuring part, there is a cylindrical through hole parallel to the center line of the stepped cylinder. An energy-saving switch push rod is installed in the cylindrical through hole. The lower end face of the energy-saving switch push rod abuts against the upper surface of the left end of the radial protrusion of the multi-contact push rod. The upper end face of the energy-saving switch push rod contacts the trigger button of the energy-saving switch.

[0010] A bottom bearing hole is provided at the bottom of the measuring part housing corresponding to the screw rod mounting hole, and a top bearing hole is provided on the top bearing. The top bearing hole is a blind hole, and the center lines of the top bearing hole and the bottom bearing hole are coaxial. The shaft at the top of the screw rod is installed in the top bearing hole, and the shaft at the bottom of the screw rod is installed in the bottom bearing hole.

[0011] The helix angle of the screw rod is 17°~25°.

[0012] The first end of the reset hairspring is mounted on the housing of the measuring section, and the second end of the reset hairspring is connected to the auger.

[0013] The screw rod mounting hole is a T-shaped hole with an open top end, and the multi-contact push rod mounting hole is a horizontal T-shaped hole with an open left and bottom end and a right side connected to the T-shaped screw rod mounting hole. The screw rod is installed in the T-shaped screw rod mounting hole with an open top end, and the multi-contact push rod is installed in the horizontal T-shaped multi-contact push rod mounting hole with an open left and bottom end and a right side connected to the T-shaped screw rod mounting hole.

[0014] A hardness tester using the indentation depth measuring device of this invention includes a support housing, a support base, an indenter sleeve, an indenter, a force-applying spring, a force-adjusting nut, a reset rod, a force-applying handle, and a second circuit board. A reset spring for the indenter sleeve is mounted on the reset rod. The support housing has a first support housing hole and a second support housing hole. A cylindrical indenter sleeve is installed in the first support housing hole, and a reset rod is installed in the second support housing hole. The top of the reset rod has a horizontal axis perpendicular to the second support housing hole, and the horizontal axis of the reset rod extends into a through hole on the indenter sleeve. The upper end of the indenter sleeve is raised slightly, and the measuring part housing is installed on the raised portion of the upper end of the indenter sleeve. The upper surface of the pressure cap contacts the force-applying handle. The bottom surface of the axially protruding top rod of the multi-contact top rod installed in the measuring part housing contacts and connects with the top surface of the indenter.

[0015] A central processing unit (CPU) is installed on the second circuit board. The magnetic field angle sensing unit and the energy-saving switch are electrically connected to the CPU. The CPU is also electrically connected to the charging and data interface, operation buttons, battery, display screen 4, and communication module. The communication module is wirelessly connected to the terminal host computer device. The CPU is used to process and calculate the hardness value. The magnetic field angle sensing unit is used to sense changes in the magnetic field angle, that is, to detect changes in the magnetic field direction of the external radially magnetized magnet through Hall elements and magnetoresistive elements. When the permanent magnet rotates, the magnetic field direction shifts relative to the Hall elements and magnetoresistive elements. The Hall elements generate a voltage difference due to the change in magnetic field strength (Hall effect), and the resistance value of the magnetoresistive element changes with the magnetic field direction (magnetoresistive effect). This is displayed on the display screen electrically connected to the CPU and transmitted to the terminal host computer device through the communication module. The energy-saving switch enables the CPU to be activated on the second circuit board during the measurement time. At other times, the circuits of the first and second circuit boards are in a low-power state. The operation buttons are used to send operation commands to the CPU, and the battery is used to provide power to the CPU. The charging and data interface is used to connect to an external power source to charge the CPU and battery and to transmit data.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] (1) The excitation end of this utility model is a passive permanent magnet, which does not require high-frequency oscillation circuit to excite. It is less affected by temperature drift and does not require external temperature sensor and compensation circuit. Therefore, the circuit structure is simple, more energy-efficient and lower in cost.

[0018] (2) The screw in this utility model is used to measure the depth of the indentation. Specifically, a magnetic field angle sensing unit and an energy-saving switch are installed on the first circuit board. The magnetic field angle sensing unit is located directly above the permanent magnet. This utility model cleverly utilizes the contact connection between the top surface of the indenter on the hardness tester and the bottom surface of the axial protrusion of the multi-contact push rod (smooth, frictionless contact) and the contact connection between the right end of the radial protrusion of the push rod and the upper spiral surface (frictional contact) to drive the screw rod to rotate. The rotating screw drives the permanent magnet to rotate. When the permanent magnet rotates under the drive of the screw, the angle of the magnetic field lines changes. The magnetic field angle sensing unit calculates the rotation angle of the screw based on the change in the angle of the magnetic field lines. Then, based on the helix angle of the upper helical surface of the screw, it calculates the distance that the multi-contact push rod moves parallel to the vertical axis within the multi-contact push rod mounting hole. That is, based on the helix angle, it calculates the distance between the bottom surface of the indenter and the bottom surface of the indenter sleeve of the hardness tester. This distance is the indentation depth. The hardness value is then calculated based on the indentation depth.

[0019] (3) The hardness tester using the indentation depth measuring device of this utility model has a first hole and a second hole on the support housing. A cylindrical indenter sleeve is installed in the first hole of the support housing, and a reset rod is installed in the second hole of the support housing. A reset spring for the indenter sleeve is installed on the reset rod. The top of the reset rod has a horizontal axis perpendicular to the second hole of the support housing. The horizontal axis of the reset rod extends into the through hole provided on the indenter sleeve. The upper end of the indenter sleeve is raised by a section. The measuring part housing is installed on the raised part of the upper end of the indenter sleeve. The upper surface of the pressure cap is in contact with the force application handle. The bottom surface of the axially protruding top rod of the multi-contact top rod installed in the measuring part housing is in contact with the top surface of the indenter. This makes the indentation depth measuring device of this utility model practically applicable. Moreover, the energy-saving switch enables the second circuit board to start the central processing unit during the measurement time. At other times, the circuits of the first circuit board and the second circuit board are in a low-energy state. Therefore, the hardness tester using the indentation depth measuring device of this utility model is more energy-efficient. Attached Figure Description

[0020] Figure 1 This is the front view of this utility model.

[0021] Figure 2 yes Figure 1 AA section view,

[0022] Figure 3 yes Figure 2 Stepped section view along BB,

[0023] Figure 4 yes Figure 3 A magnified view of part C.

[0024] Figure 5 This is a schematic diagram of the hardness tester using the indentation depth measuring device of this invention.

[0025] Figure 6 yes Figure 5 Top view,

[0026] Figure 7 yes Figure 5 A magnified view of a portion at point D.

[0027] Figure 8 This is the circuit schematic diagram of this utility model.

[0028] In the picture:

[0029] 1. Cap,

[0030] 2. Measuring unit housing,

[0031] 2-1. Helical rod mounting hole; 2-2. Multi-contact top rod mounting hole; 2-3. Cylindrical through hole;

[0032] 3. Frequent contact with the push rod,

[0033] 3-1. The push rod protrudes axially; 3-1-1. The bottom surface of the axial protrusion.

[0034] 3-2. Radial protrusion of the push rod; 3-2-1. Top of the right end of the radial protrusion; 3-2-2. Top of the left end of the radial protrusion.

[0035] 4. Screw rod,

[0036] 4-1. Spiral groove, 4-2. Upper spiral surface, 4-3. Lower spiral surface.

[0037] 5. Reset the hairspring.

[0038] 5-1. First end of the hairspring, 5-2. Second end of the hairspring,

[0039] 6.Permanent magnet,

[0040] 7. Magnetic field angle sensing unit,

[0041] 8. First circuit board,

[0042] 9. Energy-saving switch,

[0043] 10. Energy-saving switch top rod,

[0044] 11. Bottom bearing hole,

[0045] 12. Top bearing,

[0046] 13. Top bearing hole,

[0047] 14. Bottom cover,

[0048] 15. Second circuit board,

[0049] a. Spiral angle,

[0050] L1. Downward force

[0051] L2. Upward force.

[0052] N1. First torque,

[0053] N2. Second torque,

[0054] 16. Supporting the shell,

[0055] 16-1. First hole supporting the housing,

[0056] 16-2. Second hole for supporting the housing,

[0057] 17. Support base,

[0058] 18. Pressing needle sleeve,

[0059] 19. Pressing needle, 19-1. Bottom surface of pressing needle, 19-2. Top surface of pressing needle.

[0060] 20. Force-applying spring,

[0061] 21. Adjustable nut,

[0062] 22. Reset rod, 22-1. Reset rod horizontal axis,

[0063] 23. Force application handle,

[0064] 24. Test piece,

[0065] 25. Press needle sleeve return spring,

[0066] 100. Central Processing Unit (CPU)

[0067] 101. Charging and data interface,

[0068] 102. Operation buttons,

[0069] 103. Battery

[0070] 104. Display screen,

[0071] 105. Communication module,

[0072] 106. Terminal host computer equipment. Detailed Implementation Detailed Implementation Method 1

[0074] like Figure 1 — Figure 4 As shown, the technical solution adopted by this utility model includes a pressure cover 1, a lower cover 14, and a measuring part housing 2. The pressure cover 1 and the lower cover 14 are respectively connected to the measuring part housing 2 by screws. The measuring part housing 2 is a stepped cylinder in shape. Inside the measuring part housing 2, there is a spiral rod mounting hole 2-1 parallel to the center line of the stepped cylinder, a multi-contact top rod mounting hole 2-2 connected to the spiral rod mounting hole 2-1, and a cylindrical through hole 2-3.

[0075] Furthermore, the screw rod mounting hole 2-1 is a T-shaped hole with an open top, and the multi-contact top rod mounting hole 2-2 is a horizontal T-shaped hole with open left and lower ends and connected to the T-shaped screw rod mounting hole 2-1 on the right side.

[0076] A helical rod 4 is installed in the T-shaped helical rod mounting hole 2-1 with an opening at the upper end. The helical rod 4 can rotate within the T-shaped helical rod mounting hole 2-1. Furthermore, a bottom bearing hole 11 is provided in the measuring part housing 2 corresponding to the bottom of the T-shaped helical rod mounting hole 2-1, and a top bearing 12 is installed at the top of the T-shaped helical rod mounting hole 2-1. The top bearing hole 13 is a blind hole, and the center line of the top bearing hole 13 and the bottom bearing hole 11 are coaxial. The shaft at the top of the helical rod 4 is installed in the top bearing hole 13, and the shaft at the bottom of the helical rod 4 is installed in the bottom bearing hole 11. The helical rod 4 is provided with a helical groove 4-1, which contains an upper helical surface 4-2 and a lower helical surface 4-3. The helix angle α of the helical groove 4-1 is constant and is 17°–25°.

[0077] A multi-contact push rod 3 is installed in a horizontally T-shaped multi-contact push rod mounting hole 2-2, which is open at the left and lower ends and connected to the T-shaped spiral rod mounting hole 2-1 on the right side. The multi-contact push rod 3 can slide parallel along the vertical axis within the horizontally T-shaped multi-contact push rod mounting hole 2-2. Furthermore, the multi-contact push rod 3 has an axial protrusion 3-1 at the bottom and a radial protrusion 3-2 at the middle position. The bottom surface 3-1-1 of the axial protrusion 3-1 contacts the top surface of the indenter on the hardness tester during use (smooth, frictionless contact). The upper surface 3-2-1 of the right end of the radial protrusion 3-2 contacts the upper spiral surface 4-1-1 of the spiral rod 4 (frictional contact).

[0078] A reset hairspring 5 is also installed in the T-shaped screw rod mounting hole 2-1. The first end 5-1 of the reset hairspring 5 is installed on the measuring part housing 2, and the second end 5-2 of the reset hairspring 5 is connected to the screw rod 4. The reset hairspring 5 provides torque to the screw rod 4. When the torque acts on the upper helical surface 4-2, it generates a downward force L1. The upper right end 3-2-1 of the radial protrusion applies an upward force L2 to the upper helical surface 4-2. The downward force L1 and the upward force L2 are interaction forces, ensuring that the upper right end 3-2-1 of the radial protrusion is always in contact with the upper helical surface 4-1-1. When the multi-contact push rod 3 slides upward, The force applied to the upper spiral surface 4-1-1 by the right end of the radial protrusion 3-2-1 can be decomposed into an upward force L2 parallel to the axial direction and a first torque N1 perpendicular to the axial direction. The upward force L2 is borne by the top bearing 12, and the first torque N1 causes the spiral rod 4 to rotate. The reset spring 5 absorbs the first torque N1 as its own elastic force. When the multi-contact top rod 3 slides downward, the reset spring 5 releases its own elastic force and applies a second torque N2 and a downward force L1 to the spiral rod 4. Under the action of the second torque N2 and the downward force L1, the spiral rod 4 rotates and keeps the upper spiral surface 4-1-1 in contact with the right end of the radial protrusion 3-2-1.

[0079] A permanent magnet 6 is installed on the helical rod 4 in the T-shaped helical rod mounting hole 2-1. The magnetic field lines of the permanent magnet 6 are perpendicular to the axial direction of the helical rod 4.

[0080] A first circuit board 8 is installed inside the pressure cover 1. A magnetic field angle sensing unit 7 and an energy-saving switch 9 are installed on the first circuit board 8. The magnetic field angle sensing unit 7 is located directly above the permanent magnet 6 and there is a certain gap between them, so that the permanent magnet 6 and the magnetic field angle sensing unit 7 are in a non-contact state. The measuring part housing 2 and the top bearing 12 are both made of non-magnetic materials, and the magnetic lines of force can pass through the measuring part housing 2 and the top bearing 12 and be received by the magnetic field angle sensing unit 7. When the permanent magnet 6 rotates under the drive of the screw rod 4, the angle of the magnetic lines of force changes. The magnetic field angle sensing unit 7 calculates the rotation angle of the screw rod 4 based on the change in the angle of the magnetic lines of force, and then calculates the distance that the multi-contact top rod 3 moves parallel to the vertical axis in the horizontal T-shaped multi-contact top rod mounting hole 2-2 based on the helix angle. That is, the distance between the bottom surface of the indenter and the bottom surface of the indenter sleeve of the hardness tester is calculated based on the helix angle. This distance is the indentation depth, and the hardness value is then calculated based on the indentation depth.

[0081] An energy-saving switch rod 10 is installed in the cylindrical through hole 2-3. The energy-saving switch rod 10 can slide up and down along the vertical axis within the cylindrical through hole 2-3. The lower end face of the energy-saving switch rod 10 abuts against the upper surface 3-2-2 of the radial protrusion on the left side of the multi-contact rod 3. The energy-saving switch 9 is directly above the energy-saving switch rod 10. The upper end face of the energy-saving switch rod 10 contacts the trigger button of the energy-saving switch 9. When the multi-contact rod 3 slides upward, the upper surface 3-2-2 of the radial protrusion on the left side pushes the energy-saving switch rod 10 upward. The upper end face of the energy-saving switch rod 10 pushes the trigger button of the energy-saving switch 9 upward, thereby putting the first circuit 8 into the working state. Detailed Implementation Method 2

[0083] Figures 5-7 For hardness testers using the indentation depth measuring device of this utility model, such as... Figures 5-7As shown, the hardness tester using this invention includes a support housing 16. The support housing 16 has a first support housing hole 16-1 and a second support housing hole 16-2. The second support housing hole 16-2 is close to and parallel to the first support housing hole 16-1. A support base 17 is installed on the support housing 16, perpendicular to the first support housing hole 16-1. There is a certain gap between the support base 17 and the first support housing hole 16-1. A cylindrical indenter sleeve 18 is installed inside the first support housing hole 16-1. The second support housing hole 16-2 is a stepped hole. A reset rod 22 is installed inside the second support housing hole 16-2. A reset spring 25 for the indenter sleeve is installed on the reset rod 22. The top end of the reset rod 22 is perpendicular to the second hole. The reset rod horizontal axis 22-1 of 16-2 extends into the through hole provided on the pressure needle sleeve 18; a pressure needle 19 is installed inside the pressure needle sleeve 18, and the bottom surface 19-1 of the pressure needle 19 extends downward beyond the lower end face of the pressure needle sleeve 18; a force-applying spring 20 is fitted on the pressure needle 19, and an adjusting nut 21 is fitted on the upper end face of the force-applying spring 20 on the pressure needle 19, and the external thread of the adjusting nut 21 is engaged with the internal thread of the pressure needle sleeve 18; when the adjusting nut 21 is rotated, due to the characteristics of the thread, the adjusting nut 21 will move up and down axially inside the pressure needle sleeve 18, and the force applied to the pressure needle 19 is adjusted by compressing or releasing the force-applying spring 20; the top surface 19-2 of the pressure needle 19 passes upward through the through hole in the middle of the adjusting nut 21;The upper end of the pressure needle sleeve 18 is raised by a section compared to the pressure needle sleeve of the prior art for mounting this utility model. Specifically, this utility model is mounted on the raised portion of the upper end of the pressure needle sleeve 18 via the measuring housing 2. The upper surface of the pressure cap 1 contacts the force application handle 23. The bottom surface 3-1-1 of the axial protrusion 3-1 of the multi-contact push rod 3 installed in the measuring housing 2 contacts and connects with the pressure needle top surface 19-2 of the pressure needle 19 (smooth, frictionless contact). The operator pushes the pressure cap 1 downwards using the force application handle 23. The pressure cap 1 moves the measuring housing 2 and the pressure needle sleeve 18 downwards. The pressure needle bottom surface 19-1 of the pressure needle 19 first contacts the workpiece 24 and enters the workpiece 24 under the pressure of the force application spring 20. The workpiece 24 remains stationary under the support of the support base 17. The pressure needle bottom surface 19-1 of the pressure needle 19... -1 is resisted by the workpiece 24, generating a relative displacement opposite to the moving direction of the indenter sleeve 18. The top surface 19-2 of the indenter 19 pushes the bottom surface 3-1-1 of the axial protrusion 3-1 of the multi-contact push rod 3, generating a relative displacement opposite to the moving direction of the measuring housing 2. The torque generated by the multi-contact push rod 3 sliding upward in the second hole 16-2 of the housing causes the screw rod 4 to rotate. The permanent magnet 6 installed on the screw rod 4 rotates with the screw rod 4, and the magnetic lines of force of the permanent magnet 6 rotate with the permanent magnet 6. The magnetic field angle sensing unit detects and compares the absolute value of the angle of the magnetic lines of force. Based on the helix angle of the screw rod, the distance between the bottom surface 19-1 of the indenter and the full-scale reference surface is calculated (this distance is the distance between the bottom surface of the indenter and the bottom surface of the indenter sleeve of the hardness tester, which is the indentation depth). Based on this distance (indentation depth), the hardness value is then calculated.

[0084] The circuit principle of this utility model is as follows: Figure 8As shown, this utility model has a magnetic field angle sensing unit 7 and an energy-saving switch 9 on the first circuit board 8, and a central processing unit 100 on the second circuit board 15. The magnetic field angle sensing unit 7 and the energy-saving switch 9 are electrically connected to the central processing unit 100. The central processing unit 100 is also electrically connected to a charging and data interface 101, an operation button 102, a battery 103, a display screen 104, and a communication module 105. The communication module 105 is wirelessly connected to a terminal host computer device 106. The central processing unit 100 is used to process and calculate the hardness value, and the magnetic field angle sensing unit 7 is used to sense changes in the magnetic field angle, that is, to detect changes in the magnetic field direction of the external radially magnetized magnet through a Hall element and a magnetoresistive element. When the permanent magnet 6 rotates, the magnetic field direction relative to the Hall element changes. When the components and magnetoresistive elements shift, the Hall element generates a voltage difference due to the change in magnetic field strength (Hall effect), and the resistance value of the magnetoresistive element changes with the direction of the magnetic field (magnetoresistive effect). This is displayed on the display screen 104, which is electrically connected to the central processing unit 100, and simultaneously transmitted to the terminal host computer device 106 via the communication module 105. The energy-saving switch 9 enables the second circuit board 15 to start the central processing unit 100 within the measurement time. At other times, the circuits of the first circuit board 8 and the second circuit board 15 are in a low-energy consumption state. The operation button 102 is used to send operation commands to the central processing unit 100, and the battery 103 is used to provide power to the central processing unit 100. The charging and data interface 101 is used to connect an external power source to charge the central processing unit 100 and the battery 103 and to transmit data.

Claims

1. A hardness tester indentation depth measuring device comprising a gland (1), a measuring unit housing (2) and a first circuit board (8), characterized in that, The shape of the measuring part shell (2) is a stepped cylinder, and a spiral rod mounting hole (2-1) parallel to the center line of the stepped cylinder and a multi-contact ejector rod mounting hole (2-2) connected with the spiral rod mounting hole (2-1) are arranged in the inside of the measuring part shell (2); a spiral rod (4) is mounted in the spiral rod mounting hole (2-1), and a multi-contact ejector rod (3) is mounted in the multi-contact ejector rod mounting hole (2-2), the multi-contact ejector rod (3) is provided with an ejector rod axial protrusion (3-1) at the bottom, which is in contact with the top surface of the hardness tester pressure needle during use, and the multi-contact ejector rod (3) is provided with an ejector rod radial protrusion (3-2) at the middle position, the radial protrusion right end upper surface (3-2-1) of the ejector rod radial protrusion (3-2) is in contact with the upper spiral surface (4-1-1) of the spiral rod (4), a reset hair spring (5) is also mounted in the spiral rod mounting hole (2-1), a permanent magnet (6) is mounted on the spiral rod (4) in the spiral rod mounting hole (2-1), and a magnetic field angle sensing unit (7) is mounted on the first circuit board (8).

2. A hardness tester indentation depth measuring device according to claim 1, wherein, A top bearing (12) is mounted in the spiral rod mounting hole (2-1), and the measuring part shell (2) and the top bearing (12) are both non-magnetic conductive materials.

3. A hardness tester indentation depth measuring device according to claim 1, wherein, An energy-saving switch (9) is also mounted on the first circuit board (8), and a cylindrical through hole (2-3) parallel to the center line of the stepped cylinder is arranged in the inside of the measuring part shell (2), an energy-saving switch ejector rod (10) is mounted in the cylindrical through hole (2-3), the lower end surface of the energy-saving switch ejector rod (10) is in abutment with the radial protrusion left end upper surface (3-2-2) of the multi-contact ejector rod (3), and the upper end surface of the energy-saving switch ejector rod (10) is in contact with the trigger button of the energy-saving switch (9).

4. A hardness tester indentation depth measuring device according to claim 2, wherein A bottom bearing hole (11) corresponding to the bottom of the spiral rod mounting hole (2-1) is arranged in the measuring part shell (2), a top bearing hole (13) is arranged on the top bearing (12), the top bearing hole (13) is a blind hole, the center line of the top bearing hole (13) is coaxial with that of the bottom bearing hole (11), the shaft at the top of the spiral rod (4) is mounted in the top bearing hole (13), and the shaft at the bottom of the spiral rod (4) is mounted in the bottom bearing hole (11).

5. A hardness tester indentation depth measuring device according to claim 2, wherein, The helix angle (ɑ) of the spiral rod (4) is 17°-25°.

6. A hardness tester indentation depth measuring device according to claim 1, wherein The hair spring first end (5-1) of the reset hair spring (5) is mounted on the measuring part shell (2), and the hair spring second end (5-2) of the reset hair spring (5) is connected with the spiral rod (4).

7. A device for measuring the depth of indentation of a hardness tester according to claim 1, characterized in that The spiral rod mounting hole (2-1) is a positive T-shaped hole with an open upper end, the multi-contact ejector rod mounting hole (2-2) is a horizontal T-shaped hole with open left and lower ends and right side connected with the positive T-shaped spiral rod mounting hole (2-1), the spiral rod (4) is mounted in the positive T-shaped spiral rod mounting hole (2-1) with an open upper end, and the multi-contact ejector rod (3) is mounted in the horizontal T-shaped multi-contact ejector rod mounting hole (2-2) with open left and lower ends and right side connected with the positive T-shaped spiral rod mounting hole 8. A hardness tester using the indentation depth measuring device according to any one of claims 1 to 7, comprising a support housing (16), a support seat (17), a presser needle sleeve (18), a presser needle (19), a force applying spring (20), a force adjusting nut (21), a reset lever (22), a force applying handle (23), and a second circuit board (15), wherein a presser needle sleeve reset spring (25) is installed on the reset lever (22), characterized in that, The support shell (16) is provided with a support shell first hole (16-1) and a support shell second hole (16-2), a cylindrical pressure needle sleeve (18) is installed in the support shell first hole (16-1), and a reset rod (22) is installed in the support shell second hole (16-2), the top end of the reset rod (22) is provided with a reset rod transverse shaft (22-1) perpendicular to the support second hole (16-2), and the reset rod transverse shaft (22-1) extends into a through hole provided on the pressure needle sleeve (18); the upper end of the pressure needle sleeve (18) is increased by a length, the measuring part shell (2) is installed on the increased part of the upper end of the pressure needle sleeve (18), the upper surface of the pressure cover (1) is in contact with the force applying handle (23), and the bottom surface (3-1-1) of the top rod shaft protrusion (3-1) of the multi-contact top rod (3) installed in the measuring part shell (2) is in contact connection with the pressure needle top surface (19-2) of the pressure needle (19).

9. A durometer according to claim 8, wherein, The second circuit board (15) is provided with a central processing unit (100), the magnetic field angle sensing unit (7) and the energy-saving switch (9) are respectively electrically connected with the central processing unit (100), the central processing unit (100) is also respectively electrically connected with a charging and data interface (101), an operation button (102), a battery (103), a display screen (104) and a communication module (105), the communication module (105) is wirelessly connected with a terminal host computer device (106), wherein the central processing unit (100) is used for processing and calculating to obtain a hardness value, the magnetic field angle sensing unit (7) is used for sensing a magnetic field angle change, that is, a Hall element and a magnetic resistance element are used to detect a magnetic field direction change of an external radial magnetization magnet, when the permanent magnet (6) rotates, the magnetic field direction is offset relative to the Hall element and the magnetic resistance element, the Hall element generates a voltage difference (Hall effect) due to the change of the magnetic field strength, and the resistance value of the magnetic resistance element changes (magnetic resistance effect) with the change of the magnetic field direction, and the display screen (104) electrically connected with the central processing unit (100) is used for displaying, and the terminal host computer device (106) is used for transmitting through the communication module (105); the energy-saving switch (9) starts the central processing unit (100) in the measurement time, and the circuits of the first circuit board (8) and the second circuit board (15) are in a low-energy-consumption state at other times; the operation button (102) is used for sending an operation instruction to the central processing unit (100), and the battery (103) is used for providing electric energy for the central processing unit (100); and the charging and data interface (101) is used for accessing an external power supply to charge the central processing unit (100) and the battery (103) and transmit data.

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