Rockwell hardness tester testing mechanism

Abstract

The invention discloses a Rockwell hardness tester test mechanism which comprises a test force electric loading assembly installed in a vertical arm of a C-shaped machine body, a lifting ring of the test force electric loading assembly is connected with a loading rod, a screw rod section of the loading rod is matched with a transmission nut, the transmission nut is fixedly connected with a driven belt wheel, and the transmission nut and a driving belt wheel of a stepping motor are in transmission through a synchronous belt. The core lies in that the functions of rotation stopping, positioning, looseness preventing and the like are integrated, two rotation stopping schemes of a square column section and a square hole or a guiding key and a non-circular rotation stopping hole are adopted, and a spring gap eliminating structure, a photoelectric switch positioning structure, a thrust bearing supporting structure and a multiple looseness preventing structure are matched. The stepping motor is used for replacing a high-cost servo motor, the structure is simplified, energy consumption is reduced, the test force loading precision and stability are improved, disassembly, assembly and maintenance are convenient, and the device is suitable for multi-scene detection and existing equipment upgrading.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of Rockwell hardness tester, in particular to an integrated and high-precision Rockwell hardness tester test mechanism. BACKGROUND

[0002] The Rockwell hardness tester is a core equipment for metal material hardness detection. It determines the material hardness value by accurately applying test force (including initial test force and main test force) and measuring indentation depth, and is widely used in quality control fields such as mechanical processing and heat treatment. The test mechanism, as the core functional module of the Rockwell hardness tester, directly affects the accuracy of hardness measurement, operation efficiency and equipment stability in terms of structural design, integration level and control accuracy.

[0003] The test mechanism of the traditional Rockwell hardness tester is mostly designed in a decentralized manner: the test force loading relies on manual operation of the screw hand wheel, and the positioning, anti-loosening and buffering functions are realized by independent components, resulting in loose overall structure and complex assembly. For example, the applicant previously disclosed a "touch screen digital display Rockwell hardness tester" with the publication number CN110006768A, which realized overload protection and visual monitoring of initial test force loading through an electromagnetic brake and a displacement sensor, but still relied on manual operation of the screw hand wheel to load the initial test force, which was low in work efficiency and high in labor intensity. In addition, the decentralized component design easily leads to test force transmission lag, insufficient positioning accuracy, poor test stability and repeatability.

[0004] Some existing technologies attempt to use a servo motor to drive a gear or screw mechanism to realize automatic loading of the test force, which improves the loading efficiency and control accuracy. However, the servo motor needs to be matched with a high-precision drive system, which requires high power, resulting in a significant increase in equipment energy consumption and production cost, especially for small-scale detection scenarios, which is economically inefficient. At the same time, this type of solution still does not solve the problem of decentralized functions of the test mechanism. The positioning, anti-loosening and buffering functions lack collaborative design with the loading structure, and still have defects such as transmission gap, vibration interference and loose components, which affect the accuracy of hardness measurement and the reliability of long-term operation of the equipment.

[0005] Therefore, there is an urgent need for an integrated, low-cost, high-precision and stable Rockwell hardness tester test mechanism that integrates structure and function to systematically solve the pain points of traditional test mechanisms in terms of efficiency, cost, precision and maintenance. SUMMARY

[0006] To overcome the defects of the existing Rockwell hardness tester test mechanism or one of the defects, the present application provides an integrated and high-precision Rockwell hardness tester test mechanism, which integrates the functions of loading, positioning, anti-loosening, buffering and supporting through innovative integrated structure design, and balances efficiency, precision and economy.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A Rockwell hardness tester testing mechanism includes an electrically driven testing force loading assembly, which is installed inside the vertical arm of the C-shaped body of the Rockwell hardness tester. The assembly includes a lifting ring for the large lever end to enter. The upper end of the lifting ring is provided with a top head, and the lower end is connected to a loading rod. The middle section of the loading rod is a screw section threaded with a transmission nut. The transmission nut is fixedly connected to a driven pulley. The driven pulley is rotatably mounted on a fixed frame fixed to the C-shaped body. The fixed frame also has a stepper motor fixedly mounted on it. The output shaft of the stepper motor is fixedly connected to a driving pulley. The driving pulley and the driven pulley are connected by a synchronous belt drive. Unlike existing technologies, the following features are present: The lower end of the screw section is connected to a square column section, and the lower end of the square column section is connected to a cylindrical section. Two guide rods are fixed below the fixed frame on both sides of the cylindrical section. The lower ends of the guide rods are fixed to a fixed plate. A spring is sleeved on the cylindrical section and can pass through the fixed plate with a gap. The middle part of the guide rod is slidably fitted with upper and lower floating plates. The center of the upper and lower floating plates is opened with a square hole that is gap-fitted with the square column section. The upper surface of the upper and lower floating plates abuts against the interface between the screw section and the square column section. The two ends of the spring abut against the lower surface of the upper and lower floating plates and the upper surface of the fixed plate, respectively. A photoelectric switch is fixed on the fixed frame, and a sensing plate that cooperates with the photoelectric switch is fixed to the lower end of the loading rod; The driven pulley is mounted on a fixed frame via at least one thrust bearing; A keyway is provided on the transmission nut, the driven pulley is sleeved on the transmission nut and connected by a flat key, and a locking nut is screwed onto the transmission nut, the locking nut abutting against the driven pulley; a keyway is provided on the output shaft of the stepper motor, the driving pulley is sleeved on the output shaft and connected by a flat key, and a locking nut is screwed onto the output shaft of the stepper motor, the locking nut abutting against the driving pulley; At least one groove is provided on the edge of the locking nut. A loosening washer is fitted between the locking nut and the driven pulley or the driving pulley. The inner flange of the loosening washer is embedded in the keyway of the transmission nut or the output shaft, and the outer flange is embedded in the groove on the locking nut.

[0008] Furthermore, the rectangular outline of the square column segment is inscribed within the outer circle of the screw segment, and the circular outline of the cylindrical segment is tangentially connected to the rectangular outline of the square column segment.

[0009] Furthermore, when there are two thrust bearings, they are installed back-to-back.

[0010] Furthermore, the upper and lower ends of the lifting ring are screwed to the top head and the loading rod, respectively.

[0011] Another Rockwell hardness tester test mechanism, including test force electric loading assembly, the test force electric loading assembly is installed in the vertical arm of Rockwell hardness tester C-shaped fuselage, including the hanging ring for the large lever end to enter, the upper end of the hanging ring is provided with a top head, the lower end is connected with a loading rod, the middle part of the loading rod is a screw rod section and is threadedly connected with a transmission nut, the transmission nut is fixedly connected with a driven pulley, the driven pulley is rotatably arranged on a fixed frame fixedly connected with the C-shaped fuselage, and a stepping motor is also fixedly arranged on the fixed frame, the output shaft of the stepping motor is fixedly connected with a driving pulley, and the driving pulley and the driven pulley are connected through a synchronous belt transmission, which is different from the prior art: The lower end of the screw rod section is connected with a cylindrical section, the outer diameter of the cylindrical section is smaller than that of the screw rod section, and a protruding guide key is fixedly connected to the cylindrical section; a guide plate is fixedly connected below the fixed frame, a non-circular stop hole through which the cylindrical section and the guide key pass is formed in the guide plate, and an upper and lower floating plate and a spring are sleeved on the cylindrical section; the upper surface of the upper and lower floating plate abuts against the intersection surface of the screw rod section and the cylindrical section, and the two ends of the spring abut against the lower surface of the upper and lower floating plate and the upper surface of the guide plate respectively; A photoelectric switch is fixedly arranged on the fixed frame, and the lower end of the loading rod is fixedly connected with a sensing sheet matched with the photoelectric switch; The driven pulley is rotatably arranged on the fixed frame through at least one thrust bearing; A key groove is formed in the transmission nut, the driven pulley is sleeved outside the transmission nut and is connected through a flat key, and a locking nut is screwed on the transmission nut and tightly abuts against the driven pulley; a key groove is formed in the output shaft of the stepping motor, the driving pulley is sleeved on the output shaft and is connected through a flat key, and a locking nut is screwed on the output shaft and tightly abuts against the driving pulley; At least one embedding groove is formed in the edge of the locking nut, a relaxation washer is sleeved between the locking nut and the driven pulley or the driving pulley, the inner side of the relaxation washer is embedded into the key groove of the transmission nut or the output shaft, and the outer side is embedded into the embedding groove of the locking nut.

[0012] Further, the non-circular stop hole is a rectangular hole or a key groove-shaped hole, and the contour gap cooperates with the combined contour of the cylindrical section and the guide key.

[0013] Further, when the two thrust bearings are installed in a back-to-back manner.

[0014] Further, the upper and lower ends of the hanging ring are respectively screwed with the top head and the loading rod.

[0015] Compared with the prior art, the present application has the following beneficial technical effects: Integrated design enhances the overall performance of the testing mechanism: This invention integrates five major functions—test force loading, precise positioning, transmission anti-loosening, buffering and gap elimination, and axial support—into one unit, replacing the traditional decentralized design. It simplifies the internal structure of the Rockwell hardness tester, reduces assembly errors and component fit gaps, and makes test force transmission more direct, positioning more accurate, and operation more stable.

[0016] A low-cost drive solution adaptable to multiple application scenarios: Utilizing a stepper motor paired with synchronous belt drive replaces traditional high-power servo motors and complex gear drive systems, reducing the manufacturing cost and energy consumption of the drive module. The stepper motor's open-loop control logic is simple, eliminating the need for complex feedback components such as encoders. It is suitable for the "short-time loading + intermittent operation" conditions of Rockwell hardness testers, making it suitable for small-to-medium scale testing scenarios and batch applications in automated production lines, thus solving the problem of poor economic efficiency of existing servo motor solutions.

[0017] Multi-dimensional structural optimization ensures precision and stability: The anti-rotation structure uses a rigid constraint of "square column section + square hole" or "guide key + non-circular anti-rotation hole" to prevent the loading rod from rotating, ensuring that the threaded pair only transmits axial force and avoids free rotation; the backlash elimination buffer relies on the elastic preload of the spring to make the transmission components fit tightly, eliminate transmission backlash, absorb the impact force of the load, and reduce vibration interference; the transmission stability is achieved by the thrust bearing bearing the axial load, reducing the axial movement of the driven pulley and improving the smoothness of the transmission; multiple anti-loosening measures adopt a combination structure of flat key fit + lock nut + loosening washer to prevent the components from loosening under vibration environment and ensure the long-term connection stability.

[0018] Modular design and improved maintenance convenience: The lifting ring, top head, and loading rod adopt a screw connection design, and the fixing frame has a standardized installation interface, which facilitates the overall disassembly, assembly, debugging and maintenance of the testing mechanism; at the same time, it is compatible with the C-shaped body structure of different models of Rockwell hardness testers, supports the automated upgrade and transformation of existing equipment, and reduces maintenance costs and technical barriers.

[0019] In summary, this testing mechanism, through integrated design, innovative drive methods, and multi-dimensional structural optimization, solves the pain points of traditional testing mechanisms in terms of efficiency, cost, accuracy, and maintenance. It provides an economical, efficient, stable, and reliable core module solution for the automation and high-precision testing of Rockwell hardness testers. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention; Figure 2 yes Figure 1 Longitudinal sectional view; Figure 3 This is a schematic diagram of the loading rod in Example 1; Figure 4 This is a schematic diagram of the upper and lower floating plates in Example 1; Figure 5is a schematic diagram of the assembly structure of each part of the Rockwell hardness tester in Example 1; Figure 6 is a schematic diagram of the structure of Example 2 of the application; Figure 7 is a schematic diagram of the structure of Figure 6 is a cross-sectional view of Figure 8 is a schematic diagram of the structure of the loading rod in Example 2; Figure 9 is a schematic diagram of the structure of the guide plate in Example 2; Figure 10 is a schematic diagram of the assembly structure of each part of the Rockwell hardness tester in Example 2; In the figure: 1-C-shaped body; 5-test bench; 6-main shaft; 8-small lever; 9-large lever; 10-variable load device; 11-weight assembly; 15-emergency stop button; 19-press head; 100-test force electric loading assembly; 101-hanging ring; 102-top head; 103-loading rod; 1031-screw segment; 1032-square column segment; 1033-cylinder segment; 104-transmission nut; 105-fixing frame; 106-stepping motor; 107-driving pulley; 108-synchronous belt; 109-following pulley; 110-up and down floating plate; 1101-square hole; 111-guide rod; 112-fixing plate; 113-spring; 114-guide key; 115-induction sheet; 116-photoelectric switch; 117-guide plate; 1171-non-circular rotation-stopping hole; 118-thrust bearing; 119-locking nut; 120-loosening washer. DETAILED DESCRIPTION

[0021] The application will be further described below in conjunction with the drawings and specific embodiments.

[0022] In the description of the application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0023] In the description of the application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", and "connection" should be broadly understood, for example, can be fixedly connected, or can be detachably connected, or integrally connected; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium, or can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0024] Embodiment 1 As Figures 1-5 A Rockwell hardness tester test mechanism as shown in the figure, including test force electric loading assembly 100, the test force electric loading assembly 100 is installed in the vertical arm of Rockwell hardness tester C-shaped fuselage 1, including the hanging ring 101 for the end of the large lever 9 to enter, the upper end of the hanging ring 101 is provided with a top 102, the lower end is connected with a loading rod 103; the middle part of the loading rod 103 is a screw rod segment 1031 and is threadedly connected with a transmission nut 104, the transmission nut 104 is fixedly connected with a driven pulley 109, the driven pulley 109 is rotatably arranged on a fixed frame 105 fixedly connected with the C-shaped fuselage 1, the fixed frame 105 is also fixedly arranged with a stepping motor 106, the output shaft of the stepping motor 106 is fixedly connected with a driving pulley 107, the driving pulley 107 and the driven pulley 109 are drivingly connected through a synchronous belt 108.

[0025] The lower end of the screw rod segment 1031 is connected with a square column segment 1032, and the lower end of the square column segment 1032 is connected with a cylindrical segment 1033; two guide rods 111 located on both sides of the cylindrical segment 1033 are fixedly arranged below the fixed frame 105, the lower end of the guide rod 111 is fixedly connected with a fixed plate 112, the spring 113 is sleeved on the cylindrical segment 1033 and can pass through the fixed plate 112 in a gap; the middle part of the guide rod 111 is slidingly connected with an up-down floating plate 110, the center of the up-down floating plate 110 is provided with a square hole 1101 which is connected with the square column segment 1032 in a gap, the upper surface of the up-down floating plate 110 abuts against the intersection surface of the screw rod segment 1031 and the square column segment 1032, and the two ends of the spring 113 abut against the lower surface of the up-down floating plate 110 and the upper surface of the fixed plate 112 respectively.

[0026] The outer contour rectangle of the square column segment 1032 is inscribed in the outer circle of the screw rod segment 1031, and the outer contour circle of the cylindrical segment 1033 is tangent to the outer contour rectangle of the square column segment 1032.

[0027] The fixed frame 105 is fixedly arranged with a photoelectric switch 116, and the lower end of the loading rod 103 is fixedly connected with a sensing sheet 115 matched with the photoelectric switch 116.

[0028] The driven pulley 109 is rotatably arranged on the fixed frame 105 through two thrust bearings 118, and the two thrust bearings 118 are installed in a back-to-back manner.

[0029] The transmission nut 104 is provided with a key groove, the driven pulley 109 is sleeved on the transmission nut 104 and connected through a flat key, and the transmission nut 104 is screwed with a locking nut 119, and the locking nut 119 abuts against the driven pulley 109; the output shaft of the stepping motor 106 is provided with a key groove, the driving pulley 107 is sleeved on the output shaft and connected through a flat key, and the output shaft of the stepping motor 106 is screwed with a locking nut 119, and the locking nut 119 abuts against the driving pulley 107.

[0030] The locking nut 119 is provided with two symmetrical embedding grooves at the edge, the locking nut 119 is sleeved with a loose washer 120 between the driven pulley 109 or the driving pulley 107, the inner side of the loose washer 120 is embedded into the key groove of the transmission nut 104 or the output shaft, and the outer side is embedded into the embedding groove of the locking nut 119.

[0031] The upper and lower ends of the lifting ring 101 are respectively screwed with the top head 102 and the loading rod 103.

[0032] The working principle and working process of the embodiment 1 are as follows: I. Connection relationship of core components and transmission principle The core of the test mechanism of the embodiment is to drive the synchronous belt 108 transmission system through the stepping motor 106 to convert the rotary motion into the axial linear motion of the loading rod 103, and to realize the precise and stable loading of the test force by integrating the positioning, anti-loose and buffering functions. The key connection relationship of each component is as follows: Power input: the stepping motor 106 is fixed on the fixed frame 105, the output shaft is fixed with the driving pulley 107 through the combination structure of flat key + locking nut 119 + loose washer 120, and the power transmission is ensured without loosening.

[0033] Transmission link: the driving pulley 107 and the driven pulley 109 are transmitted through the synchronous belt 108, the driven pulley 109 is fixed with the transmission nut 104 through the flat key + locking nut 119 + loose washer 120, and a stable power transmission chain of “stepping motor 106→synchronous belt 108→driven pulley 109→transmission nut 104” is formed.

[0034] Linear motion conversion: the transmission nut 104 is screwed with the screw rod segment 1031 in the middle of the loading rod 103, the driven pulley 109 rotates to drive the transmission nut 104 to rotate, and the screw rod segment 1031 only moves axially due to the rotation constraint of the square column segment 1032 and the square hole 1101 (in accordance with the screw transmission principle: rotary motion→linear motion).

[0035] Buffering and clearance elimination: the pre-tightening force of spring 113 makes the upper and lower floating plates 110 always abut the intersection surface of screw rod segment 1031 and square column segment 1032, eliminating the transmission clearance of threaded pair and synchronous belt 108, and absorbing the impact force in the loading process.

[0036] Precise positioning: photoelectric switch 116 cooperates with inductive sheet 115 to detect the displacement position of loading rod 103 in real time, providing signal feedback for the start and stop of stepping motor 106.

[0037] Force transmission terminal: the hanging ring 101 at the lower end of loading rod 103 accommodates the end of large lever 9, the axial displacement of loading rod 103 is transmitted to large lever 9 through hanging ring 101 and top head 102, and then to pressure head 19 through small lever 8 and main shaft 6, realizing test force loading.

[0038] II. Stage-by-stage analysis of working process Initial state (unloaded): stepping motor 106 is not started, loading rod 103 is in the initial high position, and test force is not applied; transmission nut 104 and screw rod segment 1031 maintain the initial meshing state, spring 113 is in the pre-tightening state, and synchronous belt 108 is tensioned; the end of large lever 9 is located in the hanging ring 101 and does not bear axial force, and the pressure head 19 does not contact the measured workpiece (placed on the test bench 5).

[0039] Initial test force loading process Motor starting and transmission: the control system sends instructions, stepping motor 106 rotates clockwise, driving the driving pulley 107 to rotate, which drives the driven pulley 109 and transmission nut 104 to rotate synchronously through synchronous belt 108.

[0040] Loading rod moves down: when transmission nut 104 rotates, screw rod segment 1031 moves down due to the constraint of rotation stop, driving loading rod 103 to move downward along the axial direction.

[0041] Force transmission to large lever: loading rod 103 pushes the end of large lever 9 down through hanging ring 101 and top head 102, large lever 9 rotates around the fulcrum, and force is transmitted to pressure head 19 through small lever 8 and main shaft 6, realizing initial test force (such as 10Kgf) loading.

[0042] Position feedback and stop: when inductive sheet 115 moves with loading rod 103 to the detection position of photoelectric switch 116, photoelectric switch 116 sends a signal to the control system, stepping motor 106 stops rotating, and the initial test force is stably applied, and the pressure head 19 contacts the surface of the workpiece and produces an initial indentation.

[0043] Main test force loading process Adjustment of the load cell: According to the selected hardness scale (such as HRC, HRB), the loading force of the weight assembly 11 is adjusted by the load cell 10 (in the prior art, the weight assembly 11 is connected by a large lever 9, and in this embodiment, the test mechanism and the weight assembly 11 work together).

[0044] Secondary motor drive: The control system drives the stepper motor 106 to continue rotating clockwise, and the loading rod 103 moves further down. The force state of the large lever 9 is adjusted by the lifting ring 101 to achieve precise loading of the main test force (such as 60Kgf, 100Kgf).

[0045] Uninstallation process Reverse rotation of the motor: After the test is completed, the control system sends an unloading command, the stepper motor 106 rotates counterclockwise, the transmission nut 104 drives the screw section 1031 to move upward, the loading rod 103 is retracted, the lifting ring 101 is released from the pressure at the end of the large lever 9, and the test force is gradually unloaded.

[0046] Return to initial position: Loading rod 103 returns to its initial high position, pressure head 19 leaves the workpiece surface, sensing plate 115 and photoelectric switch 116 disengage from the detection state, and the test mechanism waits for the next test.

[0047] Example 2 like Figures 6-10 The Rockwell hardness tester mechanism shown differs from that in Example 1 in that: The lower end of the screw section 1031 is connected to the cylindrical section 1033. The outer diameter of the cylindrical section 1033 is smaller than that of the screw section 1031. A protruding guide key 114 is fixedly attached to the cylindrical section 1033. A guide plate 117 is fixedly attached below the fixing frame 105. A non-circular anti-rotation hole 1171 is provided on the guide plate 117 to allow the gap between the cylindrical section 1033 and the guide key 114 to pass through. The non-circular anti-rotation hole 1171 is a rectangular hole, and its outline is clearance-fitted with the combined outline of the cylindrical section 1033 and the guide key 114. Upper and lower floating plates 110 and springs 113 are sleeved on the cylindrical section 1033. The upper surface of the upper and lower floating plates 110 abuts against the interface between the screw section 1031 and the cylindrical section 1033. The two ends of the springs 113 abut against the lower surface of the upper and lower floating plates 110 and the upper surface of the guide plate 117, respectively.

[0048] The other structures of this embodiment 2 are the same as those of embodiment 1, including: a photoelectric switch 116 is fixed on the fixed frame 105, and a sensing plate 115 is fixed to the lower end of the loading rod 103; the driven pulley 109 is rotatably mounted on the fixed frame 105 through two back-to-back thrust bearings 118; the transmission nut 104 and the driven pulley 109, the output shaft of the stepper motor 106 and the driving pulley 107 are all fixed by a flat key + locking nut 119 + loosening washer 120; the upper and lower ends of the lifting ring 101 are screwed to the top head 102 and the loading rod 103 respectively.

[0049] The working principle of this embodiment 2 is basically the same as that of embodiment 1, and the core difference lies in the rotation-stopping and guiding structure: through the cooperation of the guide key 114 and the non-circular rotation-stopping hole 1171, the rotation of the loading rod 103 is prevented, and it is ensured that only axial force is transmitted by the threaded pair; the guide plate 117 provides a precise guide path for the loading rod 103, the pre-tightening force of the spring 113 makes the guide key 114 always fit the inner wall of the non-circular rotation-stopping hole 1171, eliminates the transmission gap, and improves the loading stability. Compared with the square column segment 1032 scheme of embodiment 1, the guide key 114 scheme of this embodiment is more flexible in processing technology and structural adaptability, and the number (single key or double key) of the guide key 114 and the shape of the non-circular rotation-stopping hole 1171 can be adjusted according to the load size and the installation space.

[0050] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A Rockwell hardness tester testing mechanism, comprising an electric loading assembly (100) for testing force, wherein the electric loading assembly (100) is installed in the vertical arm of the C-shaped body (1) of the Rockwell hardness tester, and includes a lifting ring (101) for the end of a large lever (9) to enter, wherein the upper end of the lifting ring (101) is provided with a top head (102) and the lower end is connected to a loading rod (103), wherein the middle part of the loading rod (103) is a screw section (1031) and is threaded for transmission. A nut (104) is fixedly connected to a driven pulley (109). The driven pulley (109) is rotatably mounted on a fixed frame (105) fixedly connected to the C-shaped body (1). The fixed frame (105) also has a stepper motor (106) fixedly mounted on it. The output shaft of the stepper motor (106) is fixedly connected to a driving pulley (107). The driving pulley (107) and the driven pulley (109) are connected by a synchronous belt (108). The characteristic of this device is that: The lower end of the screw section (1031) is connected to the square column section (1032), and the lower end of the square column section (1032) is connected to the cylindrical section (1033); two guide rods (111) are fixed below the fixing frame (105) on both sides of the cylindrical section (1033), and the lower end of the guide rods (111) is fixed to the fixing plate (112). A spring (113) is sleeved on the cylindrical section (1033) and can pass through the fixing plate (112) with a gap; The guide rod (111) is slidably fitted with the upper and lower floating plates (110) in the middle. The upper and lower floating plates (110) have a square hole (1101) in the center that is clearance fitted with the square column section (1032). The upper surface of the upper and lower floating plates (110) abuts against the interface between the screw section (1031) and the square column section (1032). The two ends of the spring (113) abut against the lower surface of the upper and lower floating plates (110) and the upper surface of the fixed plate (112) respectively. A photoelectric switch (116) is fixed on the fixed frame (105), and the lower end of the loading rod (103) is fixed to a sensing sheet (115) that cooperates with the photoelectric switch (116). The driven pulley (109) is rotatably mounted on the fixed frame (105) via at least one thrust bearing (118); A keyway is provided on the transmission nut (104), and the driven pulley (109) is sleeved on the transmission nut (104) and connected by a flat key. A locking nut (119) is screwed onto the transmission nut (104), and the locking nut (119) abuts against the driven pulley (109). A keyway is provided on the output shaft of the stepper motor (106), and the driving pulley (107) is sleeved on the output shaft and connected by a flat key. A locking nut (119) is screwed onto the output shaft of the stepper motor (106), and the locking nut (119) abuts against the driving pulley (107). At least one groove is provided on the edge of the locking nut (119). A loosening washer (120) is sleeved between the locking nut (119) and the driven pulley (109) or the driving pulley (107). The inner flange of the loosening washer (120) is embedded in the keyway of the transmission nut (104) or the output shaft, and the outer flange is embedded in the groove on the locking nut (119).

2. The Rockwell hardness tester testing mechanism according to claim 1, characterized in that, The rectangular outline of the square column segment (1032) is inscribed within the outer circle of the screw segment (1031), and the circular outline of the cylindrical segment (1033) is tangentially connected to the rectangular outline of the square column segment (1032).

3. The Rockwell hardness tester testing mechanism according to claim 1, characterized in that, When there are two thrust bearings (118), they are installed back to back.

4. The Rockwell hardness tester testing mechanism according to claim 1, characterized in that, The upper and lower ends of the lifting ring (101) are screwed to the top head (102) and the loading rod (103) respectively.

5. A Rockwell hardness tester testing mechanism, comprising an electric loading assembly (100) for testing force, wherein the electric loading assembly (100) is installed in the vertical arm of the C-shaped body (1) of the Rockwell hardness tester, and includes a lifting ring (101) for the end of a large lever (9) to enter, wherein the upper end of the lifting ring (101) is provided with a top head (102) and the lower end is connected to a loading rod (103), wherein the middle part of the loading rod (103) is a screw section (1031) and is threaded for transmission. A nut (104) is fixedly connected to a driven pulley (109). The driven pulley (109) is rotatably mounted on a fixed frame (105) fixedly connected to the C-shaped body (1). The fixed frame (105) also has a stepper motor (106) fixedly mounted on it. The output shaft of the stepper motor (106) is fixedly connected to a driving pulley (107). The driving pulley (107) and the driven pulley (109) are connected by a synchronous belt (108). The characteristic of this device is that: The lower end of the screw section (1031) is connected to the cylindrical section (1033). The outer diameter of the cylindrical section (1033) is smaller than that of the screw section (1031). A protruding guide key (114) is fixed on the cylindrical section (1033). A guide plate (117) is fixed below the fixing frame (105). A non-circular anti-rotation hole (1171) is opened on the guide plate (117) to allow the gap between the cylindrical section (1033) and the guide key (114) to pass through. Upper and lower floating plates (110) and springs (113) are sleeved on the cylindrical section (1033). The upper surface of the upper and lower floating plates (110) abuts against the interface between the screw section (1031) and the cylindrical section (1033). The two ends of the spring (113) abut against the lower surface of the upper and lower floating plates (110) and the upper surface of the guide plate (117), respectively. A photoelectric switch (116) is fixed on the fixed frame (105), and the lower end of the loading rod (103) is fixed to a sensing sheet (115) that cooperates with the photoelectric switch (116). The driven pulley (109) is rotatably mounted on the fixed frame (105) via at least one thrust bearing (118); A keyway is provided on the transmission nut (104), and the driven pulley (109) is sleeved on the transmission nut (104) and connected by a flat key. A locking nut (119) is screwed onto the transmission nut (104), and the locking nut (119) abuts against the driven pulley (109). A keyway is provided on the output shaft of the stepper motor (106), and the driving pulley (107) is sleeved on the output shaft and connected by a flat key. A locking nut (119) is screwed onto the output shaft of the stepper motor (106), and the locking nut (119) abuts against the driving pulley (107). At least one groove is provided on the edge of the locking nut (119). A loosening washer (120) is sleeved between the locking nut (119) and the driven pulley (109) or the driving pulley (107). The inner flange of the loosening washer (120) is embedded in the keyway of the transmission nut (104) or the output shaft, and the outer flange is embedded in the groove on the locking nut (119).

6. The Rockwell hardness tester testing mechanism according to claim 5, characterized in that, The non-circular anti-rotation hole (1171) is a rectangular hole or a keyway hole, and its outline is in clearance fit with the combined outline of the cylindrical section (1033) and the guide key (114).

7. The Rockwell hardness tester testing mechanism according to claim 5, characterized in that, When there are two thrust bearings (118), they are installed back to back.

8. The Rockwell hardness tester testing mechanism according to claim 5, characterized in that, The upper and lower ends of the lifting ring (101) are screwed to the top head (102) and the loading rod (103) respectively.

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