A lifting mechanism suitable for use with standard brinell or vickers hardness machines

Abstract

This invention provides a lifting mechanism suitable for standard Brinell or Vickers hardness tests, comprising a bottom mounting plate, a support column, a guide mounting plate, a screw jack, and a lifting tray assembly. The lifting tray assembly includes a tray and a main guide shaft. A receiving groove is provided at the bottom of the main guide shaft. The screw jack has an output screw, the top of which is connected to an adapter. The adapter abuts against the top wall of the receiving groove. A clearance groove is provided on the outer wall of the adapter near the output screw end. A set screw is also screwed onto the main guide shaft, with one end extending into the clearance groove. When the tray becomes stuck due to the main guide shaft, the screw jack descends, the adapter contacts the set screw, and as the adapter continues to descend, it pulls the main guide shaft downward, allowing the main guide shaft and the output screw to descend synchronously, preventing damage to the lifting mechanism and avoiding major safety accidents.

Description

Technical Field

[0001] This utility model relates to the field of hardness testing technology, and in particular to a lifting mechanism suitable for standard Brinell or Vickers hardness testing machines. Background Technology

[0002] Static weight hardness testers (such as standard Brinell or Vickers hardness testers) typically serve as metrological reference devices, providing traceability and transmission of measurement values. Their test force is usually generated directly from physical weights. During operation, a lifting mechanism is needed to smoothly raise and lower the physical weights to achieve the application of the test force and the switching of scales. Currently, the lifting mechanism of most standard Brinell or Vickers hardness testers consists of a motor, a reducer, a ball screw or trapezoidal screw, and an anti-rotation mechanism. The motor drives the reducer to rotate, which in turn drives the rotation of the screw and nut assembly. The screw is restricted by the anti-rotation mechanism, ultimately achieving linear motion of the screw.

[0003] For example, Chinese Patent Application No. CN202321423004.1 discloses a lifting mechanism with force measurement function suitable for a static weight hardness tester, including a crossbeam, a tray assembly, and a lifting system. The outer end of the crossbeam is mounted on the frame of the hardness tester, and a through shaft hole is opened in the center of the crossbeam. The tray assembly includes a tray, a force sensor, and a ball spline. The force sensor is located at the bottom of the tray and is fixed to the upper end of the spline shaft of the ball spline. The spline nut of the ball spline is fixedly installed at the upper end of the shaft hole. The lifting system includes a servo motor and a screw jack. The screw jack is installed at the lower end of the shaft hole. The servo motor drives the output screw of the screw jack to rise or fall in the shaft hole. When the output screw rises, it lifts the spline shaft of the ball spline.

[0004] This patent uses a motor-driven lifting mechanism to raise and lower the tray assembly. However, this mechanism has the following drawbacks: the spline shaft and the lead screw are in free contact, and when the lead screw moves downward, the spline shaft descends under its own weight. However, this mechanism lacks a safety protection mechanism. In actual operation, defects in the mechanical transmission system can obstruct the movement of the spline shaft: for example, the ball spline pair may experience lubrication failure due to long-term use, resulting in an abnormally increased frictional resistance between the spline shaft and the spline nut; or assembly precision deviations or component wear and deformation may cause the spline shaft to tilt and jam within the shaft hole. When such mechanical jamming occurs, the tray assembly remains stationary with the spline shaft, while the lead screw jack continues to descend.

[0005] Since the pallet assembly remains stationary, the lower limit switch cannot detect it, causing the lift to continue moving downwards. This can lead to damage to the lift, and in severe cases, even to the equipment tipping over, resulting in a major safety accident. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a lifting mechanism suitable for standard Brinell or Vickers hardness testers. In the event of mechanical jamming, the lifting mechanism can pull the main guide shaft downward to avoid damage to the lifting machine.

[0007] This utility model is implemented as follows:

[0008] This utility model provides a lifting mechanism suitable for standard Brinell or Vickers hardness testers, including a bottom mounting plate, a support column, a guide mounting plate, a screw jack, and a lifting tray assembly;

[0009] The screw jack is fixed to the top of the bottom mounting plate, and the guide mounting plate is fixed to the top of the base mounting plate by support columns;

[0010] The lifting pallet assembly includes a pallet and a main guide shaft installed at the bottom of the pallet;

[0011] The main guide shaft is slidably connected to the guide mounting plate, and the main guide shaft extends below the guide mounting plate. A receiving groove is provided at the bottom of the main guide shaft. The screw jack has an output screw. An adapter is connected to the top of the output screw. The adapter abuts against the top wall of the receiving groove. A clearance groove is provided on the outer wall of the adapter near the output screw end. The main guide shaft is also screwed with a set screw. The axis of the set screw is perpendicular to the axis of the main guide shaft. One end of the set screw extends into the clearance groove.

[0012] Furthermore, the lifting pallet assembly also includes three secondary guide shafts fixed to the bottom of the pallet. Centered on the main guide shaft, the three secondary guide shafts are arranged in a circular array around the main guide shaft, and all three secondary guide shafts are slidably connected to the guide mounting plate.

[0013] Furthermore, the lifting pallet assembly also includes a force sensor, which is installed at the center of the bottom of the pallet and fixed between the bottom of the pallet and the top of the main directional shaft.

[0014] Furthermore, the tray is also connected to a proximity switch contact plate, and a mounting bracket is provided on the top of the guide mounting plate. The mounting bracket is connected to two sets of proximity switches, which correspond to the upper limit position and the lower limit position of the tray, respectively.

[0015] Furthermore, the screw jack also includes a drive shaft connected to the drive assembly. The end of the drive shaft away from the drive assembly is connected to an encoder assembly via a coupling. The encoder assembly includes an encoder and a bracket fixed on the bottom mounting plate. The encoder is connected to the bracket and has a rotating shaft connected to the coupling.

[0016] The advantages of this utility model are:

[0017] 1. When the pallet becomes stuck due to the main guide shaft, the screw jack descends, the adapter contacts the set screw, and as the adapter continues to descend, it can pull the main guide shaft down, so that the positions of the main guide shaft and the output screw can descend synchronously, avoiding damage to the jack and causing a major safety accident.

[0018] 2. A force sensor is installed in the lifting tray assembly, which enables real-time monitoring of the force value. Especially when the weights are loaded in stages, the force sensor can measure the force value of each loading. By installing an encoder assembly at the end of the screw jack drive shaft, the position of the screw jack drive shaft can be detected in real time, improving the safety performance of the screw jack and increasing the level of automation. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a schematic diagram of a lifting mechanism structure applicable to a standard Brinell or Vickers hardness tester.

[0021] Figure 2 yes Figure 1 Cross-section of the structure shown Figure 1 .

[0022] Figure 3 yes Figure 2 Enlarged view of a portion of point A in the middle.

[0023] Figure 4 yes Figure 1 Cross-section of the structure shown Figure 2 .

[0024] Figure 5 yes Figure 4 Enlarged view of section B in the middle.

[0025] Figure 6 for Figure 1 Side view of the structure shown.

[0026] Figure 7 This is a schematic diagram of the encoder structure in this utility model.

[0027] Explanation of the labels in the diagram:

[0028] 1. Bottom mounting plate; 2. Support column; 3. Guide mounting plate; 4. Screw jack; 41. Output screw; 5. Lifting tray assembly; 51. Tray; 52. Main guide shaft; 521. Receiving groove; 53. Secondary guide shaft; 54. Force sensor; 55. Drive shaft; 6. Adapter; 61. Clearance groove; 7. Set screw; 8. Proximity switch contact plate; 9. Mounting bracket; 10. Proximity switch; 11. Encoder assembly; 111. Encoder; 1111. Rotating shaft; 112. Bracket; 12. Coupling; 13. Servo motor; 14. Worm gear reducer. Detailed Implementation

[0029] Please see Figures 1 to 7 This utility model provides a lifting mechanism suitable for standard Brinell or Vickers hardness testers, including a bottom mounting plate 1, a support column 2, a guide mounting plate 3, a screw jack 4, and a lifting tray assembly 5;

[0030] The screw jack 4 is fixed to the top of the bottom mounting plate 1, and the guide mounting plate 3 is fixed to the top of the bottom mounting plate by the support column 2;

[0031] The lifting pallet assembly 5 includes a pallet 51 and a main guide shaft 52 installed at the bottom of the pallet 51;

[0032] The main guide shaft 52 is slidably connected to the guide mounting plate 3, and the main guide shaft 52 extends below the guide mounting plate 3. A receiving groove 521 is provided at the bottom of the main guide shaft 52. The screw jack 4 has an output screw 41, which rises and falls along its axial direction. An adapter 6 is connected to the top of the output screw 41. The adapter 6 abuts against the top wall of the receiving groove 521. A clearance groove 61 is provided on the outer wall of the adapter 6 near the output screw 41. The clearance groove 61 makes the outer side of the adapter 6 form a stepped structure. The main guide shaft 52 is also spirally connected with a set screw 7. Three set screws 7 are arranged in a circular array on the main guide shaft 52. The axis of the set screw 7 is perpendicular to the axis of the main guide shaft 52. One end of the set screw 7 extends into the clearance groove 61. When the top of the adapter 6 contacts the top wall of the receiving groove 521, a gap of less than or equal to 6 mm is maintained between the top wall of the clearance groove 61 and the outer wall of the set screw 7. When the screw jack 4 descends, if the lifting tray assembly 5 does not jam, it can descend synchronously with the screw jack 4. If the lifting tray assembly 5 jams, the adapter 6 descends first when the screw jack 4 descends. When the adapter 6 descends to a predetermined distance (e.g., 6 mm), it contacts the set screw 7. As the adapter 6 continues to descend, it pulls the main guide shaft 52 downwards via the set screw 7, ensuring that the main guide shaft 52 and the screw jack 4 descend synchronously, preventing damage to the jack and a major safety accident.

[0033] Specifically, the lifting pallet assembly 5 also includes three secondary guide shafts 53 fixed to the bottom of the pallet 51. Centered on the main guide shaft 52, the three secondary guide shafts 53 are arranged in a circular array around the main guide shaft 52, and all three secondary guide shafts 53 are slidably connected to the guide mounting plate 3. In the prior art, a ball spline is used as the main guide shaft without other secondary guide shafts, resulting in limited load-bearing capacity and unsuitability for loads with large Brinell hardness scales. In this application, however, the use of one main guide shaft 52 and three secondary guide shafts 53 allows for greater load capacity and prevents the main guide shaft 52 from easily deforming.

[0034] Specifically, the lifting tray assembly 5 also includes a force sensor 54, which is installed at the center of the bottom of the tray 51 and fixed between the bottom of the tray 51 and the top of the main guide shaft 52. The force sensor 54 installed in the lifting tray assembly 5 enables real-time monitoring of the force value, especially during graded loading of weights, where the force sensor 54 can measure the force value of each loading.

[0035] Specifically, the tray 51 is also connected to a proximity switch contact plate 8, and a mounting bracket 9 is provided on the top of the guide mounting plate 3. The mounting bracket 9 is connected to two sets of proximity switches 10, which correspond to the upper limit position and the lower limit position of the tray 51, respectively. When the lifting tray assembly 5 rises to the upper limit position, the proximity switch contact plate 8 corresponds to the upper set of proximity switches 10, and at this time, the servo motor 13 stops operating. When the lifting tray assembly 5 descends to the lower limit position, the proximity switch contact plate 8 corresponds to the lower set of proximity switches 10, and at this time, the servo motor 13 stops operating.

[0036] Specifically, the screw jack 4 further includes a drive shaft 55 connected to the drive assembly. The end of the drive shaft 55 furthest from the drive assembly is connected to an encoder assembly 11 via a coupling 12. The encoder assembly 11 includes an encoder 111 and a bracket 112 fixed to the bottom mounting plate 1. The encoder 111 is connected to the bracket 112 and has a rotating shaft 1111 connected to the coupling 12. The drive assembly consists of a servo motor 13 and a worm gear reducer 14 connected to the servo motor 13. The drive shaft 55 is connected to the worm gear reducer 14 to drive the drive shaft 55 to rotate. The encoder assembly 11 can detect the position of the drive shaft 55 of the screw jack 4 in real time.

[0037] By incorporating a force sensor 54 and an encoder assembly 11, the safety performance of the screw jack 4 can be improved, and the automation level of the standard Brinell or Vickers hardness tester can be enhanced.

[0038] The advantages of this invention are as follows: When the pallet becomes stuck due to the main guide shaft, the screw jack descends, the adapter contacts the set screw, and as the adapter continues to descend, it pulls the main guide shaft downwards, allowing the main guide shaft and the output screw to descend synchronously, preventing damage to the jack and avoiding major safety accidents. A force sensor is installed in the lifting pallet assembly, enabling real-time monitoring of force values. Especially during graded loading of weights, the force sensor can measure the force value of each loading. By installing an encoder assembly at the end of the screw jack's drive shaft, the position of the drive shaft can be detected in real time, improving the safety performance of the screw jack and enhancing its automation level.

[0039] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A lifting mechanism suitable for use with a standard Brinell or Vickers hardness machine, characterised in that: It includes a bottom mounting plate, support columns, guide mounting plate, screw jack, and lifting tray assembly; The screw jack is fixed to the top of the bottom mounting plate, and the guide mounting plate is fixed to the top of the base mounting plate by support columns; The lifting pallet assembly includes a pallet and a main guide shaft installed at the bottom of the pallet; The main guide shaft is slidably connected to the guide mounting plate, and the main guide shaft extends below the guide mounting plate. A receiving groove is provided at the bottom of the main guide shaft. The screw jack has an output screw. An adapter is connected to the top of the output screw. The adapter abuts against the top wall of the receiving groove. A clearance groove is provided on the outer wall of the adapter near the output screw end. The main guide shaft is also screwed with a set screw. The axis of the set screw is perpendicular to the axis of the main guide shaft. One end of the set screw extends into the clearance groove.

2. A lifting mechanism suitable for standard Brinell or Vickers hardness testers as described in claim 1, characterized in that: The lifting pallet assembly also includes three secondary guide shafts fixed to the bottom of the pallet. Centered on the main guide shaft, the three secondary guide shafts are arranged in a circular array around the main guide shaft, and all three secondary guide shafts are slidably connected to the guide mounting plate.

3. A lifting mechanism suitable for standard Brinell or Vickers hardness testers as described in claim 1, characterized in that: The lifting pallet assembly also includes a force sensor, which is mounted at the center of the bottom of the pallet and fixed between the bottom of the pallet and the top of the main directional shaft.

4. A lifting mechanism suitable for standard Brinell or Vickers hardness testers as described in claim 1, characterized in that: The tray is also connected to a proximity switch contact plate. A mounting bracket is provided on the top of the guide mounting plate. The mounting bracket is connected to two sets of proximity switches, which correspond to the upper limit position and the lower limit position of the tray, respectively.

5. A lifting mechanism suitable for standard Brinell or Vickers hardness testers as described in claim 1, characterized in that: The screw jack also includes a drive shaft connected to the drive assembly. The end of the drive shaft away from the drive assembly is connected to an encoder assembly via a coupling. The encoder assembly includes an encoder and a bracket fixed on the bottom mounting plate. The encoder is connected to the bracket and has a rotating shaft connected to the coupling.

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