Brinell hardness tester with double objective lenses and single pressure head

Abstract

The utility model relates to a double-objective-lens single-pressure-head Brinell hardness tester which comprises a shell, a turntable housing is arranged at the inner top of the shell, and a rotatable three-function-position turret mechanism is arranged in the turntable housing. Through the design of the three-functional-position turret mechanism, the hardness tester can switch different measuring functions by rotating the turret under the condition that a workpiece is not moved, so that the flexibility and the efficiency of measurement are improved, the display screen is embedded in the laminated board, measurement results can be conveniently checked, parameters can be conveniently set, and the hardness tester is convenient to use. The observation end of the eyepiece mechanism extends to the outer side through the opening in the laminated board, so that a user can directly observe a measurement result, the design of the lifting spinning roller mechanism enables the user to adjust a measurement position according to needs, so that the accuracy of the measurement result is ensured, the design of double objective lenses enables the hardness tester to observe indentations under different magnification times, and the hardness tester is convenient to use. And due to the design of the single detection pressure head, the structure of the hardness tester is simplified, and the manufacturing cost is reduced.

Description

Technical Field

[0001] This utility model relates to the technical field of Brinell hardness testers, and in particular to a Brinell hardness tester with dual objectives and a single indenter. Background Technology

[0002] Hardness testing is a crucial part of materials science and engineering. It is used to assess a material's resistance to compressive deformation and is a key indicator for material quality control and performance evaluation. Traditional hardness testing methods, such as Brinell hardness testing, usually rely on manual operation and mechanical structures, which have problems such as complex operation, limited testing accuracy, and low testing efficiency. Traditional Brinell hardness testers usually have a single station and require manual replacement of test samples or test components, which not only increases the difficulty of operation but also limits the testing efficiency. Utility Model Content

[0003] In view of this, the purpose of this utility model is to provide a dual-objective single-indenter Brinell hardness tester with multiple measurement functions, simple operation, high measurement accuracy and low cost.

[0004] To achieve the above objectives, this utility model employs a dual-objective, single-indenter Brinell hardness tester, comprising a housing, a panel mounted on the front surface of the housing, a display screen embedded in the panel, a turntable cover on the inner top of the housing, a rotatable three-position turret mechanism within the turntable cover, an eyepiece mechanism on one side of the three-position turret mechanism, the observation end of the eyepiece mechanism extending to the outside of the panel through an opening in the panel, a main shaft mechanism within the housing connected to one end of the three-position turret mechanism, a lever mechanism on one side of the main shaft mechanism, and a lifting wheel mechanism at the inner bottom of the housing, the lifting wheel mechanism being located on the vertically opposite side of the three-position turret mechanism.

[0005] The advantages of the above structure are as follows: the three-function turret mechanism allows the hardness tester to switch between different measurement functions by rotating the turret without moving the workpiece, thereby improving the flexibility and efficiency of measurement; the display screen is embedded in the panel for easy viewing of measurement results and setting of parameters; the observation end of the eyepiece mechanism extends to the outside through the opening on the panel, allowing the user to directly observe the measurement results; the lifting wheel mechanism allows the user to adjust the measurement position as needed, thereby ensuring the accuracy of the measurement results; the dual objective lens design allows the hardness tester to observe the indentation at different magnifications, improving the accuracy and flexibility of measurement; and the single detection indenter design simplifies the structure of the hardness tester and reduces manufacturing costs.

[0006] This utility model is further configured as a lifting and rotating wheel mechanism, comprising a lead screw bushing installed at the bottom of the housing, a rotating wheel disposed on the lead screw bushing, a lead screw passing through the inner rings of the lead screw bushing and the rotating wheel, and a lead screw nut cooperating with the lead screw. A handle is rotatably engaged around the rotating wheel. The lifting and rotating wheel mechanism, through the cooperation of the lead screw bushing, the rotating wheel, the lead screw, and the lead screw nut, achieves precise adjustment of the lifting function. Users can rotate the handle to move the rotating wheel up and down on the lead screw, thereby precisely controlling the lifting height. The handle design, with its rotatable engagement around the rotating wheel, allows users to easily adjust the lifting height by rotating the handle, making operation simple and quick.

[0007] This utility model is further configured as a three-function turret mechanism including a support plate, a turret motor connection mechanism mounted on one end of the upper surface of the support plate, and a three-function turret assembly located below the support plate. The three-function turret assembly includes a turret, a central shaft assembly disposed within the turret, a first objective lens and a second objective lens respectively connected around the turret, and a detection indenter assembly. One end of the central shaft assembly is connected to the support plate, and the other end extends to the outside of the turntable cover through a central opening on the turret. The design of the turret motor connection mechanism enables the three-function turret mechanism to achieve automated rotation. The design of the three-function turret mechanism allows the hardness tester to quickly switch between objective lenses or detection indenters under different measurement requirements, thereby meeting the hardness measurement needs of various materials.

[0008] This utility model is further configured such that the detection pressure head assembly includes a linear motion ball bearing mounted on the turret and a detection pressure head rod passing through the inner ring of the linear motion ball bearing. A pressure head rod cap is fixed to the top of the detection pressure head rod, and a steel ball pressure head is inserted into and engaged at the end of the detection pressure head rod. A spring washer is provided between the linear motion ball bearing and the pressure head rod cap. The spring washer is respectively close to the upper part of the linear motion ball bearing and the lower part of the pressure head rod cap. A spring is installed between the spring washer. An adjustment ring is also fitted at the end of the detection pressure head rod located at the steel ball pressure head. The observation ends of the first and second objectives and the steel ball pressure head end of the detection pressure head assembly all extend outside the turntable cover. The indenter assembly achieves precise movement and positioning of the indenter during measurement through the cooperation of linear motion ball bearings and indenter rods. The spring washers and springs provide buffering and protection. When the steel ball indenter contacts the sample, the springs absorb part of the impact force, thus protecting the indenter and sample from damage. The adjustment ring allows users to adjust the position and height of the indenter as needed, adapting to different measurement requirements and sample types.

[0009] This invention further comprises a first objective lens and a second objective lens, each having a corresponding reflector assembly at one end of the support plate. The reflector assembly includes a lens cover and a reflector located at the lower end of the lens cover. The lens cover is connected to the turret via a first column. The reflector assembly effectively enhances light utilization. When light passes through the objective lens into the hardness meter, the reflector reflects some of the light, allowing it to pass through the objective lens again, thereby increasing the amount of light transmitted and improving the brightness and clarity of the measurement.

[0010] This utility model further comprises a turret motor connection mechanism including a turret motor connection plate mounted on one side of the upper surface of a support plate, and a motor bracket mounted on the turret motor connection plate. A turret motor is installed between the motor bracket and the turret motor connection plate, and a small pulley is connected to the motor shaft end of the turret motor. The turret motor connection mechanism mounts the turret motor on the support plate via the turret motor connection plate and the motor bracket, resulting in a more compact overall structure and saving space. The small pulley connected to the motor shaft end of the turret motor enables efficient transmission.

[0011] This invention further comprises an eyepiece mechanism including an eyepiece adjustment block mounted on the upper surface of a support plate on the opposite side, an eyepiece adjustment plate mounted on one side of the eyepiece adjustment block, an eyepiece block mounted on one side of the eyepiece adjustment plate, an eyepiece tube inserted into the eyepiece block, and an eyepiece extending into and engaging the end of the eyepiece tube. An auxiliary frame is mounted on the turret corresponding to the eyepiece tube, and a third objective lens is mounted on the auxiliary frame. Through the combination of the eyepiece adjustment block, eyepiece adjustment plate, eyepiece block, eyepiece tube, and eyepiece, the eyepiece mechanism achieves precise adjustment and magnification of the observed image, allowing the observer to adjust the position and focal length of the eyepiece as needed, thereby obtaining a clearer and more detailed image. The third objective lens mounted on the auxiliary frame further increases the system's magnification, enabling the observer to observe even finer details.

[0012] This invention further includes a Hall effect mounting block and a power supply mounting plate within the housing. The Hall effect mounting block is located on one side of the lever assembly and mounted on the inner wall of the housing. A Hall bracket is fixed to one end of the Hall effect mounting block, and an arc groove is formed on the Hall bracket. A Hall switch is installed in the arc groove, and the Hall switch is secured to the Hall bracket by a nut. The power supply mounting plate is mounted on the inner wall of the housing opposite the Hall effect mounting block. Through the design of the Hall effect mounting block, its Hall bracket, and the Hall switch, the system can sense the displacement or rotation state of the lever assembly and feed it back to the control system in the form of an electrical signal. This allows the hardness tester to monitor the movement state of the lever assembly in real time and accurately, thereby achieving precise control of the measurement process. The power supply mounting plate provides stable power support for the hardness tester, transmitting power signals to various components that require power, ensuring the normal operation of the hardness tester.

[0013] This invention further comprises photoelectric fixing plates and steel ball positioning plates mounted on the side walls of the support plate. The photoelectric fixing plates are equipped with photoelectric switches. The steel ball positioning plates have a steel ball positioning block at the end facing the turret, with a hole in which a steel ball is embedded. A positioning plate fixing block is also mounted on the steel ball positioning plate. The turret is further equipped with a positioning connecting block and a positioning pin. By adding the photoelectric fixing plates and photoelectric switches, combined with the positioning connecting block and positioning pin on the turret, a precise position feedback mechanism is provided for the turret. When the turret rotates to a designated position, the positioning pin accurately triggers the photoelectric switch, thereby ensuring the precise positioning of the turret during measurement or observation. The design of the steel ball positioning plates and steel ball positioning blocks, through the cooperation of the steel ball and the hole, achieves precise positioning of the steel ball, improving not only the positioning accuracy but also enhancing the positioning stability, enabling the turret to maintain an accurate position during rotation or movement.

[0014] This utility model is further configured with an upper cover plate, a rear cover plate, and side cover plates covering the housing. A three-pronged switch and a printer are respectively installed on the side cover plates, and feet are installed at the bottom of the housing. The upper cover plate, rear cover plate, and side cover plates provide complete external protection for the hardness tester. These covers not only prevent dust, moisture, and other external factors from entering the hardness tester, but also effectively prevent damage caused by accidental collisions. The three-pronged switch and printer installed on the side cover plates allow users to easily control the start and stop of the hardness tester and print measurement results, improving the ease of operation and facilitating maintenance and inspection. The feet ensure that the hardness tester can be placed stably on a level surface, avoiding shaking or tilting caused by uneven ground. Attached Figure Description

[0015] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model.

[0016] Figure 2 This is a schematic diagram of the internal structure of an embodiment of the present utility model.

[0017] Figure 3 This is an exploded view of the three-function turret mechanism according to an embodiment of the present invention.

[0018] Figure 4 This is an exploded schematic diagram of the detection pressure head assembly according to an embodiment of this utility model.

[0019] Figure 5 This is a schematic diagram of the reflector assembly on the turret according to an embodiment of the present invention.

[0020] Figure 6 This is a schematic diagram of the eyepiece mechanism and the third objective lens in an embodiment of the present invention.

[0021] Figure 7 This is an exploded view of the Hall mounting block and power mounting plate and housing according to an embodiment of this utility model.

[0022] Figure 8 This is a side view of the Hall switch mounting structure on the Hall mounting block according to an embodiment of the present invention.

[0023] Figure 9 This is an exploded view of the support plate and turret of an embodiment of this utility model.

[0024] Figure 10 This is an exploded view of the spindle mechanism according to an embodiment of the present invention.

[0025] Figure 11 This is a front view of the spindle mechanism according to an embodiment of the present invention.

[0026] Figure 12 This is a side view of the cooperation between the spindle mechanism and the lever mechanism in an embodiment of this utility model.

[0027] Figure 13 This is a three-dimensional schematic diagram of the lever mechanism according to an embodiment of the present utility model.

[0028] Figure 14 This is a three-dimensional schematic diagram of the shell according to an embodiment of the present utility model. Detailed Implementation

[0029] like Figures 1-14 As shown, an embodiment of this utility model provides a dual-objective single-indenter Brinell hardness tester, including a housing 1. The front surface of the housing 1 is equipped with a panel 2, and the panel 2 is embedded with a display screen 21. The inner top of the housing 1 is provided with a turntable cover 3. The turntable cover 3 is provided with a rotatable three-position turret mechanism 4. An eyepiece mechanism 5 is provided on one side of the three-position turret mechanism 4. The observation end of the eyepiece mechanism 5 extends to the outside of the panel 2 through an opening 22 on the panel 2. The housing 1 is provided with a spindle mechanism 6, which is connected to one end of the three-position turret mechanism 4. A lever mechanism 7 is provided on one side of the spindle mechanism 6. The inner bottom of the housing 1 is provided with a lifting wheel mechanism 8, which is located on the vertically opposite side of the three-position turret mechanism 4. The housing 1 is also covered with an upper cover plate 11, a rear cover plate 12, and a side cover plate 13. A three-pronged switch 131 and a printer 132 are respectively installed on the side cover plate 13. The bottom of the housing 1 is also equipped with four feet 14.

[0030] like Figure 2As shown, the lifting wheel mechanism 8 includes a lead screw bushing 81 installed at the bottom of the housing 1, a wheel 82 set on the lead screw bushing 81, a lead screw 83 that passes through the inner rings of the lead screw bushing 81 and the wheel 82 respectively, and a lead screw nut 84 that cooperates with the lead screw 83. A handle 85 is rotatably engaged around the wheel 82.

[0031] like Figure 3 As shown, the three-function turret mechanism 4 includes a support plate 41, a turret motor connection mechanism 42 mounted on one side of the upper surface of the support plate 41, and a three-function turret assembly 43 located below the support plate 41. The three-function turret assembly 43 includes a turret 45, a central shaft assembly 46 disposed within the turret 45, a first objective lens 47 and a second objective lens 48 respectively connected around the turret 45, and a detection pressure head assembly 49. One end of the central shaft assembly 46 is connected to the support plate 41, and the other end extends to the turntable cover 3 through a central opening 451 on the turret 45. The turret motor connection mechanism 42 includes a support plate 41 mounted on one side of the upper surface of the support plate 41. The turret motor connecting plate 421 and the motor bracket 422 mounted on the turret motor connecting plate 421 are connected together. The turret motor 423 is installed between the motor bracket 422 and the turret motor connecting plate 421. The motor shaft end of the turret motor 423 is connected to a small pulley 424. The small pulley 424 is connected to the driven pulley (not shown in the figure) on the turret 45 through a transmission belt (not shown in the figure) to form a transmission system. The central shaft assembly 46 only shows the central shaft itself in the figure. However, we can understand that in actual applications, the central shaft assembly 46 also includes necessary bearings, bushings, fasteners, etc., to ensure the smooth rotation and precise positioning of the central shaft.

[0032] like Figure 4 As shown, the detection pressure head assembly 49 includes a linear motion ball bearing 491 mounted on the turret 45 and a detection pressure head rod 492 passing through the inner ring of the linear motion ball bearing 491. A pressure head rod cap 493 is fixed to the top of the detection pressure head rod 492, and a steel ball pressure head 494 is inserted into and engaged at the end of the detection pressure head rod 492. Two spring washers 495 are provided between the linear motion ball bearing 491 and the pressure head rod cap 493. The two spring washers 495 are respectively close to the top of the linear motion ball bearing 491 and the bottom of the pressure head rod cap 493. A spring 496 is installed between the spring washers 495. An adjustment ring 497 is also fitted at one end of the detection pressure head rod 492 located at the steel ball pressure head 494. The observation ends of the first objective lens 47 and the second objective lens 48, as well as the steel ball pressure head end of the detection pressure head assembly 49, all extend out of the turntable cover 3.

[0033] like Figure 5As shown, the first objective lens 47 and the second objective lens 48 are each provided with a reflector assembly 44 at one end of the support plate 41. The reflector assembly 44 includes a lens cover 441 and a reflector 442 disposed at the lower end of the lens cover 441. The lens cover 441 and the turret 45 are connected by two first columns 443.

[0034] like Figure 6 As shown, the eyepiece mechanism 5 includes an eyepiece adjustment block 51 mounted on the upper surface of the support plate 41 on the opposite side, an eyepiece adjustment plate 52 mounted on one side of the eyepiece adjustment block 51, an eyepiece block 53 mounted on one side of the eyepiece adjustment plate 52, an eyepiece tube 54 inserted through the eyepiece block 53, and an eyepiece 55 extending into and snapped into the end of the eyepiece tube 54. The turret 45 is equipped with an auxiliary lens holder 452 corresponding to the eyepiece tube 55, and a third objective lens 453 is mounted on the auxiliary lens holder 452.

[0035] like Figures 7-8 As shown, the housing 1 also includes a Hall mounting block 15 and a power mounting plate 16. The Hall mounting block 15 is located on one side of the lever assembly 7 and is installed on the inner wall of the housing 1. One end of the Hall mounting block 15 is fixed with a Hall bracket 151. The Hall bracket 151 has two arc grooves, and each arc groove is provided with a Hall switch 152. The Hall switches 152 are snapped onto the Hall bracket 151 by two nuts 153. The power mounting plate 16 is installed on the inner wall of the housing 1 opposite to the Hall mounting block 15.

[0036] like Figure 9 As shown, photoelectric fixing plates 40 and steel ball positioning plates 50 are also installed on the side wall of the support plate 41. The photoelectric fixing plate 40 has a photoelectric switch 401 installed at one end corresponding to the turret 45. The steel ball positioning plate 50 has a steel ball positioning block 501 at the end facing the turret 45. The steel ball positioning block 501 has a hole with a steel ball 502 embedded in it. The upper and lower ends of the steel ball positioning plate 50 are also equipped with positioning plate fixing blocks 503 for fixing. The turret 45 is also equipped with three positioning connecting blocks 454 and a positioning pin 455.

[0037] like Figures 10-11As shown, the spindle mechanism 6 mainly consists of a spindle seat 61, a sensor 62, a spindle 63, a spindle bushing 65, and a spindle compression spring 66. The sensor 62 is installed at one end of the spindle seat 61, and the spindle 63 is fixed at the other end. The end of the sensor 62 extends into and engages with a pressure head support 64. The pressure head support 64 extends to the lower end through a reserved slot on the support plate 41. The other end of the spindle seat 61 is fitted with a spindle bushing 65 that is sleeved on the outer surface of the spindle 63 to reduce friction. Then, a spindle compression spring 66 is wound around the spindle bushing 65 to provide preload. A groove is opened at the end of the spindle 63 away from the spindle seat 61. A main tool pad 67 is placed in the groove, and a round tool tip 671 is placed on the main tool pad 67. The entire spindle mechanism 6 is encapsulated by the spindle seat 68 and the spindle cover 69, and is connected to the support plate 41 through the second column 60.

[0038] like Figures 12-13As shown, the lever mechanism 7 is located on one side of the main shaft mechanism 6 and mainly consists of key components such as a base plate 71, a stepper motor assembly 72, a lead screw assembly 73, and a lever assembly 74. A motor mounting plate 721 is securely mounted on the base plate 71, thereby fixing the stepper motor 722. The stepper motor 722 serves as the power source, and its motor shaft is cleverly connected to a pulley 723 for power transmission. The lead screw assembly 73 is built into the base plate 71, and its core components include a screw sleeve 731 and a lead screw 732. The screw sleeve 731 has an outer... The wall is fitted with a lower bearing, a middle spacer ring, and an upper round nut in sequence. These components work together to ensure the stability and precision of the structure. The lower end of the screw sleeve 731 is tightly engaged in the large pulley 733, working in conjunction with the large pulley to realize the transmission and conversion of power. The top of the lead screw 732 supports the lever assembly 74, which includes a connecting seat 741 and a rear lever 742. The rear lever 742 is mounted on the connecting seat 741, and the bearings 744 are engaged on both sides of the rear lever 742 through the lever shaft 743 to ensure the stability of the rear lever. To ensure the smoothness and precision of the lever mechanism 742 during operation, the rear lever 742 has a magnet seat 77 on the side facing the Hall switch 152. The magnet seat 77 has a magnet cap 78. The connecting seat 741 and the lead screw 732 are tightly connected via a connector 75, forming a stable whole and ensuring the stability and reliability of the lever mechanism 74. Furthermore, the rear lever 742 is equipped with an auxiliary lever assembly 76, which includes components such as a blade holder 761, a lever blade pad 762, and a lever blade tip 763. Both the inner top and bottom ends of the frame 761 are equipped with lever blade pads and lever blade tips. The lever blade pads are fitted with lever blade tips, forming a stable support structure. The rear lever 742 is placed on the lever blade tip at the inner bottom end of the blade pad frame 761. At the same time, an auxiliary lever 762 is also placed on the lever blade tip at the inner top end of the blade pad frame 761. The end of the auxiliary lever 762 is provided with a main shaft opening, which can just accommodate the top end of the main shaft 63, realizing a precise connection with the round blade tip 671 on the main shaft 63, thereby ensuring the efficient, stable and reliable operation of the lever mechanism 74.

[0039] The first objective lens 47 is a 1x objective lens, the second objective lens 48 is a 2x objective lens, and the third objective lens 453 is a 0.8x objective lens. The steel ball indenter 494 in the indenter assembly 49 can be 2.5mm in diameter, 5mm in diameter, or 10mm in diameter, and can be replaced through actual operation.

[0040] Of course, in addition to the above embodiments, this utility model may have other various embodiments. Without departing from the essential technical solution of this utility model, those skilled in the art can make various corresponding changes and modifications based on this utility model, and these changes or modifications are equivalent to the technical solution in this patent. Therefore, these corresponding changes and modifications should all fall within the protection scope of the appended claims of this utility model.

Claims

1. A double-objective, single-indenter Brinell hardness tester, characterized in that: The device includes a housing, a panel on the front surface of which is embedded with a display screen, a turntable cover on the inner top of the housing, a rotatable three-position turret mechanism inside the turntable cover, an eyepiece mechanism on one side of the three-position turret mechanism, the observation end of the eyepiece mechanism extending to the outside of the panel through an opening in the panel, a main shaft mechanism inside the housing connected to one end of the three-position turret mechanism, a lever mechanism on one side of the main shaft mechanism, and a lifting wheel mechanism on the inner bottom of the housing, located on the vertically opposite side of the three-position turret mechanism.

2. The Brinell hardness tester with dual objectives and a single indenter according to claim 1, characterized in that: The lifting wheel mechanism includes a lead screw bushing installed at the bottom of the housing, a wheel set on the lead screw bushing, a lead screw passing through the inner ring of the lead screw bushing and the wheel respectively, and a lead screw nut cooperating with the lead screw. A handle is rotatably engaged around the wheel.

3. The Brinell hardness tester with dual objectives and single indenter according to claim 1 or 2, characterized in that: The three-function turret mechanism includes a support plate, a turret motor connection mechanism mounted on one end of the upper surface of the support plate, and a three-function turret assembly located below the support plate. The three-function turret assembly includes a turret, a central shaft assembly located inside the turret, a first objective lens and a second objective lens respectively connected around the turret, and a detection pressure head assembly. One end of the central shaft assembly is connected to the support plate, and the other end extends to the outside of the turntable cover through a central opening on the turret.

4. The Brinell hardness tester with dual objectives and a single indenter according to claim 3, characterized in that: The detection pressure head assembly includes a linear motion ball bearing mounted on the turret and a detection pressure head rod passing through the inner ring of the linear motion ball bearing. A pressure head rod cap is fixed to the top of the detection pressure head rod, and a steel ball pressure head is inserted into and engaged at the end of the detection pressure head rod. A spring washer is provided between the linear motion ball bearing and the pressure head rod cap. The spring washer is respectively close to the upper part of the linear motion ball bearing and the lower part of the pressure head rod cap. A spring is installed between the spring washer. An adjustment ring is also fitted at the end of the detection pressure head rod located at the steel ball pressure head. The observation ends of the first and second objectives and the steel ball pressure head end of the detection pressure head assembly all extend outside the turntable cover.

5. The Brinell hardness tester with dual objectives and a single indenter according to claim 3, characterized in that: The first objective lens and the second objective lens are each provided with a reflector assembly at one end of the support plate. The reflector assembly includes a lens cover and a reflector disposed at the lower end of the lens cover. The lens cover is connected to the turret through a first column.

6. The Brinell hardness tester with dual objectives and a single indenter according to claim 3, characterized in that: The turret motor connection mechanism includes a turret motor connection plate mounted on one side of the upper surface of the support plate, a motor bracket mounted on the turret motor connection plate, a turret motor installed between the motor bracket and the turret motor connection plate, and a small pulley connected to the motor shaft end of the turret motor.

7. The Brinell hardness tester with dual objectives and single indenter according to claim 3, characterized in that: The eyepiece mechanism includes an eyepiece adjustment block mounted on the upper surface of the support plate on the opposite side, an eyepiece adjustment plate mounted on one side of the eyepiece adjustment block, an eyepiece block mounted on one side of the eyepiece adjustment plate, an eyepiece tube inserted through the eyepiece block, and an eyepiece extending into and snapped into the end of the eyepiece tube. The turret is equipped with an auxiliary lens frame corresponding to the eyepiece tube, and a third objective lens is mounted on the auxiliary lens frame.

8. The Brinell hardness tester with dual objectives and a single indenter according to claim 1, characterized in that: The housing also includes a Hall mounting block and a power mounting plate. The Hall mounting block is located on one side of the lever assembly and is installed on the inner wall of the housing. A Hall bracket is fixed to one end of the Hall mounting block. An arc groove is formed on the Hall bracket, and a Hall switch is installed in the arc groove. The Hall switch is snapped onto the Hall bracket by a nut. The power mounting plate is installed on the inner wall of the housing opposite to the Hall mounting block.

9. The Brinell hardness tester with dual objectives and a single indenter according to claim 3, characterized in that: The side wall of the support plate is also equipped with a photoelectric fixing plate and a steel ball positioning plate. The photoelectric fixing plate is equipped with a photoelectric switch. The steel ball positioning plate has a steel ball positioning block at the end facing the turret. The steel ball positioning block has a hole with a steel ball embedded in it. The steel ball positioning plate is also equipped with a positioning plate fixing block. The turret is also equipped with a positioning connecting block and a positioning pin.

10. The Brinell hardness tester with dual objectives and a single indenter according to claim 1, characterized in that: The housing is also covered with an upper cover plate, a rear cover plate, and side cover plates. A three-pronged switch and a printer are respectively installed on the side cover plates. The bottom of the housing is also equipped with feet.

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