Sample fixing device of horizontal ball-rod type contact fatigue testing machine

Abstract

The utility model discloses a sample fixing device of a horizontal ball-rod type contact fatigue testing machine, and belongs to the technical field of material detection. One end of the base is inserted into a sample, and the other end of the base is clamped on a drill chuck of a testing machine; the pin radially penetrates through the base and the sample in a detachable manner; the limiting clamp is arranged on the outer side wall of the base and is matched with the pin; the sample is inserted into a counter bore formed in the end face of the base through the damping rubber ring, and through holes matched with the pins are formed in the base, the damping rubber ring and the sample in the radial direction. According to the utility model, the sample can be well fixed, the sample can be effectively kept stable in the high-speed rotation process of the sample, meanwhile, the initial amplitude of a contact fatigue test is greatly reduced, and the contact fatigue life of the sample is greatly prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of material testing, and particularly relates to a specimen fixing device for a horizontal ball-bar contact fatigue testing machine. Background Art

[0002] In the field of contact fatigue testing machines, the specimen rotating device is a crucial component. For example, a horizontal ball-bar contact fatigue testing machine disclosed in Chinese Patent Document CN111175159B uses a high-precision drill chuck to fix the specimen, and a ball device composed of two outer rings of conical bearings and multiple ball bearings is used to apply contact stress to the specimen. Although this drill chuck has high initial precision, there are some technical problems in the actual application process.

[0003] Firstly, in order to ensure that the specimen does not slip during high-speed rotation, a relatively large clamping force needs to be applied. However, this excessive clamping force will cause deformation and wear of the drill chuck during use. These deformation and wear problems will gradually reduce the precision of the drill chuck, resulting in the radial runout of the clamped specimen exceeding 0.02 mm. This radial runout not only affects the accuracy of the test data but also has a negative impact on the reliability of the test results.

[0004] Secondly, due to the deformation and wear of the chuck, the coaxiality of the rotation center in the contact area between the specimen and the ball bearings deteriorates. The reduction in coaxiality will cause the contact stress distribution on the specimen during operation to be uneven, thereby increasing the contact stress. This excessive contact stress will accelerate the fatigue damage of the specimen and further shorten the contact fatigue life of the specimen.

[0005] To solve the above problems, it is necessary to regularly replace the drill chuck and adjust the coaxiality of the contact area between the specimen and the ball bearings. This frequent replacement and adjustment not only increase the maintenance cost but also may affect the continuity of the test and the comparability of the data. Therefore, there is a need for a specimen fixing device for a horizontal ball-bar contact fatigue testing machine that can improve the contact fatigue life of the specimen and is convenient and fast to operate. Summary of the Utility Model

[0006] The purpose of the utility model is to provide a specimen fixing device for a horizontal ball-bar contact fatigue testing machine, which can achieve good fixation of the specimen, keep the specimen stable during high-speed rotation of the specimen, reduce the initial amplitude of the contact fatigue test, and improve the contact fatigue life of the specimen.

[0007] To achieve the above purpose, the technical solution adopted by the utility model is:

[0008] A specimen fixing device for a horizontal ball bar type contact fatigue testing machine, comprising a base with one end inserted into the specimen and the other end clamped on the drill chuck of the testing machine, a pin radially penetrating the base and the specimen in a detachable manner, and a limit fixture arranged on the outer side wall of the base and adapted to the pin; the specimen is inserted into a counterbore opened on the end face of the base through a shock-absorbing rubber ring, and the base, the shock-absorbing rubber ring and the specimen are all radially provided with through holes adapted to the pin.

[0009] A further improvement of the technical solution of the present utility model lies in that: the lower end of the pin is gradually reduced in diameter along its axial direction to form a frustum of a cone, and a card slot adapted to the limit fixture is opened along the circumferential direction of the frustum of the cone.

[0010] A further improvement of the technical solution of the present utility model lies in that: the limit fixture includes a pin shaft arranged on the outer side wall of the base and two clamping arms oppositely arranged and hinged through the pin shaft; the clamping arms include an arc-shaped clamping end adapted to the card slot of the pin and an operating end integrally formed with the arc-shaped clamping end and extending along the tangent direction of the arc-shaped clamping end, and the operating ends of the two clamping arms are connected through a return spring.

[0011] A further improvement of the technical solution of the present utility model lies in that: two arc-shaped chutes are symmetrically opened on the outer side wall of the base, and the operating ends of the two clamping arms are respectively slidably connected with the arc-shaped chutes through sliders.

[0012] A further improvement of the technical solution of the present utility model lies in that: the radian of the arc-shaped chute is adapted to the movement track of the clamping arm.

[0013] A further improvement of the technical solution of the present utility model lies in that: the card slot is arranged at the maximum diameter of the frustum of the cone.

[0014] Due to the adoption of the above technical solution, the technical progress achieved by the present utility model is:

[0015] The specimen fixing device of the horizontal ball bar type contact fatigue testing machine of the present utility model can achieve good fixation of the specimen, effectively keep the specimen stable during the high-speed rotation of the specimen, and at the same time, greatly reduce the initial amplitude of the contact fatigue test, and the contact fatigue life of the specimen is greatly improved.

[0016] This utility model adopts a base with one end inserted into the specimen and the other end clamped on the drill chuck of the testing machine, a pin that radially penetrates the base and the specimen in a detachable manner, and a limit fixture arranged on the outer side wall of the base and adapted to the pin; the specimen is inserted into a counterbore opened on the end face of the base through a shock-absorbing rubber ring, and the base, the shock-absorbing rubber ring, and the specimen are all radially provided with through holes adapted to the pin. Among them, the pin is used to position the specimen in the counterbore of the base and restrict and fix the pin through the limit fixture. When the base rotates driven by the drill chuck, the specimen also rotates accordingly; the limit fixture can effectively prevent the pin from detaching under the action of the rotational torque, avoiding damage to the specimen and unnecessary safety accidents; the counterbore can generate a uniform clamping force on the specimen through the shock-absorbing rubber ring. Compared with the clamping force of the drill chuck, it can be evenly distributed to the entire contact surface of the specimen through the shock-absorbing rubber ring, avoiding deformation or damage caused by excessive local pressure; the shock-absorbing rubber ring has good shock-absorbing performance, can absorb and reduce vibrations during the test, greatly reduces the initial amplitude of the contact fatigue test to a certain extent, and effectively improves the fatigue life of the specimen.

[0017] The pin adopted by this utility model cooperates with the limit fixture. Among them, the lower end of the pin gradually tapers along its axial direction to form a frustum of a cone, and the frustum of the cone is provided with a card slot adapted to the limit fixture along its circumferential direction; the limit fixture includes a pin shaft arranged on the outer side wall of the base and two clamping arms hinged through the pin shaft. The clamping arms include an arc-shaped clamping end adapted to the card slot of the pin and an operating end integrally formed with the arc-shaped clamping end and extending along the tangent direction of the arc-shaped clamping end. The operating ends of the two clamping arms are connected through a return spring, and two arc-shaped sliding grooves are symmetrically opened on the outer side wall of the base. The operating ends of the two clamping arms are respectively slidably connected to the arc-shaped sliding grooves through sliders. When the pin penetrates the base to fix the specimen in its counterbore, as the pin moves downward, its frustum of the cone gradually pushes open the two clamping arms of the limit fixture. At this time, the operating ends of the two clamping arms slide relatively away along the arc-shaped sliding grooves, the return spring is stretched, and the arc-shaped clamping ends of the two clamping arms open and are clamped in the card slot of the pin frustum, thereby achieving the purpose of fixing the pin to prevent the pin from slipping off, ensuring operation safety and avoiding damage to the specimen at the same time. Description of the Drawings

[0018] Figure 1 is a schematic structural diagram of the specimen fixing device of this utility model; s

[0019] Figure 2 is a schematic structural diagram of the limit fixture in the specimen fixing device of this utility model;

[0020] Figure 3 is a schematic structural diagram of the pin in the specimen fixing device of this utility model;

[0021] Among them, 1. Base, 1-1. Arc-shaped chute, 2. Pin, 2-1. Frustum, 2-2. Card slot, 3. Shock-absorbing rubber ring, 4. Specimen, 5. Limit fixture, 5-1. Pin shaft, 5-2. Clamping arm, 5-3. Return spring, 5-4. Slide block, 6. Ball device. Detailed implementation mode

[0022] The following further elaborates on the present utility model in conjunction with embodiments:

[0023] As Figures 1-3 shown, the present utility model provides a specimen fixing device for a horizontal bat-type contact fatigue testing machine, including a base 1, a pin 2, a shock-absorbing rubber ring 3, and a limit fixture 5. Among them, one end of the base 1 is clamped on the drill chuck of the testing machine, and the other end is inserted with a specimen 4. Specifically, the specimen 4 is inserted into a counterbore opened on the end face of the base 1 through the shock-absorbing rubber ring 3. The shock-absorbing rubber ring 3 is located in the counterbore of the base 1 and is adapted to it. The counterbore of the base 1 can generate a uniform clamping force on the specimen 4 through the shock-absorbing rubber ring 3. Compared with the clamping force of the drill chuck, it can be evenly distributed to the entire contact surface of the specimen 4 through the shock-absorbing rubber ring 3, avoiding deformation or damage caused by excessive local pressure. At the same time, the shock-absorbing rubber ring 3 has good shock-absorbing performance and can absorb and reduce vibrations during the test, greatly reducing the initial amplitude of the contact fatigue test to a certain extent and effectively improving the fatigue life of the specimen 4; after the specimen 4 is inserted into the base 1, the pin 2 radially penetrates the base 1 and the specimen 4 in a detachable manner. The base 1, the shock-absorbing rubber ring 3, and the specimen 4 are all radially provided with through holes adapted to the pin 2. If the specimen 4 itself has a radial through hole, it is necessary to ensure that the pin 2 selected is adapted to this through hole. Correspondingly, the through holes formed by drilling equipment on the base 1 and the shock-absorbing rubber ring 3 are also adapted to it. If the specimen 4 itself does not have a radial through hole, it is necessary to use drilling equipment to radially drill a hole at one end of it, and the through holes on the base 1, the shock-absorbing rubber ring 3, and the specimen 4 are all adapted; the pin 2 is used to position the specimen 4 in the counterbore of the base 1, and the limit fixture 5 is arranged on the outer side wall of the base 1 and is adapted to the pin 2. By restricting and fixing the pin 2 through the limit fixture 5, it can effectively prevent the pin 2 from disengaging under the action of the rotational torque, avoiding damage to the specimen 4 and unnecessary safety accidents. When the base 1 rotates driven by the drill chuck, the specimen 4 also rotates accordingly, so that the specimen 4 rotates in the ball device 6, and the ball device 6 applies contact stress to the specimen 4.

[0024] Specifically, the lower end of the pin 2 gradually tapers along its axial direction to form a frustum 2-1, and the frustum 2-1 is provided with a card slot 2-2 adapted to the limit fixture 5 along its circumferential direction. Preferably, the card slot 2-2 is arranged at the maximum diameter of the frustum 2-1. When the pin 2 radially penetrates from the upper opening of the through hole of the base 1 to its lower opening, the card slot 2-2 on the frustum 2-1 is just located outside the lower opening of the through hole of the base 1.

[0025] The limit fixture 5 includes a pin shaft 5-1, two clamping arms 5-2 and a return spring 5-3. The pin shaft 5-1 is arranged on the outer side wall of the base 1, and the pin shaft 5-1 is located on one side of the lower opening of the through hole of the base 1. The two clamping arms 5-2 are arranged oppositely and are hinged through the pin shaft 5-1. The clamping arm 5-2 includes an arc-shaped clamping end and an operating end. The arc-shaped clamping end is adapted to the clamping groove 2-2 of the pin 2. The operating end is integrally formed with the arc-shaped clamping end and extends along the tangent direction of the arc-shaped clamping end. The return spring 5-3 is arranged between the operating ends of the two clamping arms 5-2. When the return spring 5-3 is in the reset state, the distance between the arc-shaped clamping ends of the two clamping arms 5-2 is adapted to the minimum diameter of the frustum 2-1 of the pin 2. Correspondingly, two arc-shaped sliding grooves 1-1 are symmetrically formed on the outer side wall of the base 1. The operating ends of the two clamping arms 5-2 are respectively slidably connected with the arc-shaped sliding grooves 1-1 through sliders 5-4. The radian of the two arc-shaped sliding grooves 1-1 is adapted to the movement track of the two clamping arms 5-2.

[0026] When the pin 2 penetrates through the base 1 to fix the specimen 4 in its counterbore, as the pin 2 moves downward, the frustum cone 2-1 on the pin 2 gradually pushes open the two clamping arms 5-2 of the limit fixture 5 due to the structural advantage of its downward diameter reduction. At this time, the operating ends of the two clamping arms 5-2 slide relatively away along the arc-shaped sliding grooves 1-1, and the return spring 5-3 is stretched. The arc-shaped clamping ends of the two clamping arms 5-2 open and are clamped in the clamping groove 2-2 on the frustum cone 2-1, so as to achieve the purpose of fixing the pin 2 to prevent the pin 2 from slipping off, ensuring the operation safety and avoiding damage to the specimen at the same time; when the pin 2 needs to be taken out, by means of an external force, the operating ends of the two clamping arms 5-2 continue to slide relatively away along the arc-shaped sliding grooves 1-1, and the return spring 5-3 is further stretched, so that the arc-shaped clamping ends of the two clamping arms 5-2 open. After the pin 2 is taken out, the return spring 5-3 quickly resets, and the operating ends of the two clamping arms 5-2 slide relatively close along the arc-shaped sliding grooves 1-1, so that the arc-shaped clamping ends of the two clamping arms 5-2 return to their original positions.

[0027] It can be understood that the present utility model is described through some embodiments. Those skilled in the art know that without departing from the spirit and scope of the present utility model, various changes or equivalent replacements can be made to these features and embodiments. In addition, under the teaching of the present utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present utility model. Therefore, the present utility model is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the scope protected by the present utility model.

Claims

1. A specimen fixing device for a horizontal ball bar contact fatigue testing machine, characterized in that: It includes a base (1) with one end inserted into the specimen (4) and the other end clamped on the drill chuck of the testing machine, a pin (2) radially penetrating the base (1) and the specimen (4) in a detachable manner, and a limit fixture (5) arranged on the outer side wall of the base (1) and adapted to the pin (2); the specimen (4) is inserted into a counterbore formed on the end face of the base (1) through a shock-absorbing rubber ring (3), and through holes adapted to the pin (2) are radially formed on the base (1), the shock-absorbing rubber ring (3), and the specimen (4).

2. The sample fixing device of a horizontal ball-bar contact fatigue testing machine according to claim 1, characterized in that: The lower end of the pin (2) is gradually reduced in diameter along its axial direction to form a frustum (2-1), and a card slot (2-2) adapted to the limit fixture (5) is formed on the frustum (2-1) along its circumferential direction.

3. The sample fixing device of a horizontal ball bar contact fatigue testing machine according to claim 2, characterized in that: The limit fixture (5) includes a pin shaft (5-1) arranged on the outer side wall of the base (1) and two clamping arms (5-2) arranged oppositely and hinged through the pin shaft (5-1); each clamping arm (5-2) includes an arc-shaped clamping end adapted to the card slot (2-2) of the pin (2) and an operating end integrally formed with the arc-shaped clamping end and extending along the tangent direction of the arc-shaped clamping end, and the operating ends of the two clamping arms (5-2) are connected through a return spring (5-3).

4. The specimen fixing device of a horizontal ball-bar contact fatigue testing machine according to claim 3, characterized in that: Two arc-shaped sliding grooves (1-1) are symmetrically formed on the outer side wall of the base (1), and the operating ends of the two clamping arms (5-2) are respectively slidably connected to the arc-shaped sliding grooves (1-1) through sliders (5-4).

5. The specimen fixing device of a horizontal ball-bar contact fatigue testing machine according to claim 4, characterized in that: The radian of the arc-shaped sliding groove (1-1) is adapted to the movement track of the clamping arm (5-2).

6. The specimen fixing device of a horizontal ball-bar contact fatigue testing machine according to any one of claims 2-5, characterized in that: The card slot (2-2) is arranged at the position with the largest diameter of the frustum (2-1).

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