Electric automobile bolt tensile testing machine

Abstract

The application discloses an electric automobile bolt tensile testing machine, and relates to the technical field of mechanical property testing of electric automobile parts. The electric automobile bolt tensile testing machine comprises a base, a lower clamping device and an upper clamping device. The lower clamping device is used for positioning a nut and limiting rotation of the nut. The upper clamping device comprises a bolt mounting clamp used for clamping a bolt, a clamping structure used for clamping the bolt and aligning the bolt with the nut, and a rotating structure used for driving the bolt to rotate around an axis of the bolt. The clamping structure aligns the bolt with the nut before the bolt rotates. The rotating structure drives the bolt to rotate under the condition that the nut is limited to rotate, so that the bolt is screwed into the nut to realize automatic cooperation. After the bolt is screwed into the nut, the upper clamping device and the lower clamping device move axially relative to each other, axial tension is applied to the bolt and the nut, and a tensile test is conducted. The testing machine can improve clamping alignment accuracy and testing efficiency, and realizes automatic cooperation clamping and tensile testing.

Description

Technical Field

[0001] This invention relates to the field of mechanical performance testing technology for electric vehicle components, specifically to an electric vehicle bolt tensile strength testing machine. Background Technology

[0002] High-strength bolts are extensively used in the chassis, body, and power battery of electric vehicles. The tensile strength of these bolts directly affects the reliability and safety of the entire vehicle connection. Therefore, tensile tests on the bolts are necessary before assembly. Currently, semi-automatic testing machines are commonly used for bolt tensile testing: the operator first loads the bolt into the upper clamping device, places the matching nut into the lower clamping device and manually straightens it, then manually aligns the bolt with the nut end face and screws it in, before activating the loading mechanism to apply axial tensile force for testing.

[0003] The aforementioned semi-automatic testing machine has the following shortcomings in the clamping process: First, the alignment of the bolt and nut relies on visual inspection by the operator, resulting in unstable alignment accuracy. Forcing the bolt and nut to engage when there is a deviation between their axes can easily cause misalignment, skewing, and damage to the threads, leading to the failure of the test sample. Second, the nut tends to rotate with the bolt during the engagement process, requiring additional clamping or manual straightening, which is cumbersome and inefficient. Third, the machine involves a significant amount of manual intervention, resulting in poor clamping consistency, which directly affects the accuracy of the tensile strength test results. It also involves high labor intensity and is difficult to meet the requirements of batch testing.

[0004] Therefore, how to automatically align the bolt and nut, without the nut moving, and then reliably apply axial tensile force to complete the tensile test, is a problem urgently needing to be solved in this field. To this end, the present invention provides a tensile testing machine for electric vehicle bolts. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a tensile testing machine for electric vehicle bolts, which solves the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an electric vehicle bolt tensile strength testing machine, comprising a base, a lower clamp disposed on the base for positioning a nut and restricting the rotation of the nut; and an upper clamping device disposed opposite to the lower clamp for clamping bolts, wherein a lifting mounting plate is fixedly installed on the upper end face of the upper clamping device, and the lifting mounting plate is slidably installed on the lifting frame; The upper clamping device includes a bolt mounting clamp for clamping the bolt, a clamping structure for clamping the bolt and aligning the bolt with the nut, and a rotating structure for driving the bolt to rotate about its own axis; wherein, the clamping structure aligns the bolt with the nut before the bolt rotates, and the rotating structure drives the bolt to rotate while the lower clamp restricts the rotation of the nut, so that the bolt is screwed into the nut to achieve automatic engagement; the upper clamping device and the lower clamp move relative to each other axially after the bolt is screwed into the nut, applying axial tensile force to the bolt and the nut to conduct a tensile test; The upper clamping device also includes a flange whose upper end face is fixedly connected to the lifting mounting plate. A rotating structure is fixedly installed on the lower end face of the flange. A clamping shell is fixedly installed on the lower end face of the rotating structure. A clamping structure is installed inside the clamping shell. The clamping structure clamps a bolt mounting fixture.

[0007] As a preferred embodiment of the present invention, the clamping structure includes a central positioning block fixedly installed on the lower end face of the compression and release push rod. The central positioning block includes a positioning block body, a tapered positioning hole opened on the lower end face of the positioning block body, and compression springs fixedly installed on both sides of the positioning block body.

[0008] As a preferred embodiment of the present invention, the bolt mounting fixture includes a fixture mounting column, the upper end face of which is fixedly mounted with a taper, the taper cooperating with a tapered positioning hole to guide the bolt to be centered axially.

[0009] As a preferred embodiment of the present invention, the bolt mounting fixture further includes an anti-offset structure fixedly installed between the fixture mounting column and the bolt fixture body, and an anti-bolt rotation structure installed on both sides of the bolt mounting position. The anti-offset structure is used to limit the radial offset of the bolt relative to the bolt mounting fixture, and the anti-bolt rotation structure is used to limit the rotation of the bolt during the alignment process between the bolt and the nut, so as to avoid misalignment and screwing when the bolt is not aligned.

[0010] As a preferred embodiment of the present invention, the anti-bolt rotation structure includes an inner low-pressure rod and an outer low-pressure rod. The bolt mounting fixture is provided with a bolt mounting position, and an anti-rotation block is provided at the bolt mounting position. One end of the inner low-pressure rod is fixedly installed on one side of the anti-rotation block, and the outer low-pressure rod is sleeved on the outside of the inner low-pressure rod. A spring is also provided between the inner low-pressure rod and the outer low-pressure rod. The anti-bolt rotation structure is used to hold the bolt against it with low pressure from both sides, and the bolt anti-rotation block is used to prevent the bolt from rotating at the bolt installation position.

[0011] As a preferred embodiment of the present invention, the clamping structure includes a hydraulic rod and a clamping block. The hydraulic rod drives the clamping block to move radially along the bolt via a power slider, so as to clamp or release the bolt.

[0012] As a preferred embodiment of the present invention, the clamping block includes a clamping block body, a guide groove disposed on the clamping block body, and a clamping groove installed inside the clamping block body, wherein the clamping block is guided to slide by the guide groove.

[0013] As a preferred embodiment of the present invention, the rotating structure is connected to the bolt mounting fixture for driving the bolt mounting fixture and the bolt to rotate around the bolt's axis, and when the rotating structure drives the bolt to rotate, the clamping structure maintains the clamping of the bolt.

[0014] As a preferred embodiment of the present invention, the lower clamping includes a lower clamping body fixedly installed on the upper end face of the base and a lower bolt mounting fixture disposed on the lower clamping body. The lower bolt mounting fixture includes a bolt mounting bracket body fixedly installed on the upper end face of the tapered mounting column, an anti-rotation nut mounting position disposed at the center of the bolt mounting bracket body, and a bolt guide hole mounted on the upper end face of the anti-rotation nut mounting position. The anti-rotation nut mounting position is configured to have the same external contour as the bolt.

[0015] As a preferred embodiment of the present invention, it further includes a lifting frame and a lifting mounting plate. The lifting mounting plate is slidably disposed on the lifting frame. The upper clamping device is disposed on the lower end face of the lifting mounting plate. The lifting mounting plate drives the upper clamping device to move up and down along the lifting frame so that the bolt approaches the nut axially and is screwed into the nut. After the bolt is screwed into the nut, an axial tensile force is applied to the bolt and the nut.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention, by setting up lower and upper clamping devices, uses a clamping structure to center the bolt and nut before the bolt rotates. Then, with the nut restricted from rotation by the lower clamp, a rotating structure drives the bolt to rotate and screw into the nut, achieving automatic clamping. This avoids misalignment when the bolt is not aligned, thus improving clamping efficiency and reliability. Furthermore, by setting a centering positioning block with its tapered positioning hole and compression spring, the bolt receives tapered guidance and elastic floating support during alignment, which improves clamping accuracy and ensures the coaxiality of the loading axis during tensile testing.

[0017] 2. This invention, by setting the taper of the upper end face of the clamping mounting column to match the tapered positioning hole, allows the bolt to automatically align axially when approaching the nut, which helps ensure that the bolt axis and the nut axis are consistent during testing. Furthermore, by setting anti-offset and anti-bolt rotation structures, this invention restricts bolt offset and rotation during alignment, preventing misalignment and ensuring thread protection and the validity of the test sample. Finally, by setting the anti-rotation nut mounting position in the lower clamp, this invention restricts the nut to an anti-rotation position, preventing it from rotating during bolt engagement and loading, thus ensuring the accuracy of tensile force testing. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the electric vehicle bolt tensile strength testing machine of the present invention; Figure 2 This is a schematic diagram of the upper clamping device; Figure 3 This is a schematic cross-sectional view of the upper clamping device; Figure 4 This is a schematic diagram of the clamping structure; Figure 5 This is an exploded view of the clamping block and the centering positioning block; Figure 6 A schematic diagram of the bolt mounting fixture; Figure 7 A schematic diagram showing the structure for preventing bolt rotation and the bolt installation position; Figure 8 This is a schematic diagram of the lower clamping structure; Figure 9 This is a cross-sectional structural diagram of the bolt mounting fixture.

[0019] In the diagram: 1. Lifting frame; 2. Lifting mounting plate; 3. Upper clamping device; 31. Flange; 32. Clamping housing; 33. Bolt mounting fixture; 331. Fixture mounting column; 332. Taper; 333. Bolt fixture body; 334. Anti-offset structure; 335. Anti-bolt rotation structure; 3351. Inner low-pressure rod; 3352. Outer low-pressure rod; 336. Bolt installation position; 3361. Bolt anti-rotation block; 34. Clamping structure; 341. Sealing plate; 342. Hydraulic rod; 343. Piston seal; 344. Power slider; 345. Clamping block; 34 51. Guide groove; 3452. Clamping block body; 3453. Clamping groove; 346. Centering positioning block; 3461. Positioning block body; 3462. Tapered positioning hole; 3463. Compression spring; 347. Compression block; 348. Compression release push rod; 349. Sealing sleeve; 35. Rotating structure; 4. Lower clamp; 41. Lower clamping body; 42. Lower bolt mounting fixture; 421. Bolt mounting bracket body; 422. Anti-rotation nut mounting position; 423. Bolt guide hole; 424. Tapered mounting column; 425. Mounting column fixing structure; 5. Base; Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0021] like Figure 1 As shown, this embodiment provides a tensile strength testing machine for electric vehicle bolts, including a base 5, a lower clamp 4, and an upper clamping device 3. The base 5 is located at the bottom of the device and is used to support the lower clamp 4 and the upper clamping device 3. The lower clamp 4 is located on the base 5 and is used to position the nut and restrict its rotation; the upper clamping device 3 is arranged opposite to the lower clamp 4 and is used to clamp the bolt. A lifting mounting plate 2 is fixedly installed on its upper end face. The lifting mounting plate 2 is slidably installed on the lifting frame 1, so that the upper clamping device 3 can move up and down along the lifting frame 1 with the lifting mounting plate 2.

[0022] like Figure 2 , Figure 3As shown, the upper clamping device 3 includes a bolt mounting fixture 33 for clamping bolts, a clamping structure 34 for clamping bolts and aligning bolts with nuts, and a rotating structure 35 for driving bolts to rotate around their own axis. The upper clamping device 3 also includes a flange 31 whose upper end face is fixedly connected to the lifting mounting plate 2. The rotating structure 35 is fixedly installed on the lower end face of the flange 31. A clamping housing 32 is fixedly installed on the lower end face of the rotating structure 35. The clamping structure 34 is installed inside the clamping housing 32. The clamping structure 34 clamps the bolt mounting fixture 33, thereby connecting the lifting mounting plate 2, flange 31, rotating structure 35, clamping housing 32, clamping structure 34, and bolt mounting fixture 33 sequentially along the axial direction into a single unit.

[0023] The working principle of this embodiment is as follows: The nut is placed in the lower clamp 4, which positions and restricts the rotation of the nut; the bolt to be tested is installed in the bolt mounting fixture 33 of the upper clamping device 3; the clamping structure 34 is activated to clamp the bolt and align the bolt with the nut; after the bolt and nut are aligned, the rotating structure 35 drives the bolt to rotate around its own axis. Since the nut is restricted from rotating by the lower clamp 4, the bolt is screwed into the nut axially during the rotation, achieving automatic clamping; then the upper clamping device 3 moves along the lifting frame 1 with the lifting mounting plate 2, so that the bolt and nut are subjected to axial tension, completing the tensile test. Example

[0024] like Figure 4 , Figure 5 As shown, based on Embodiment 1, the clamping structure 34 includes a centering positioning block 346, which is fixedly installed on the lower end face of the compression release push rod 348. The centering positioning block 346 includes a positioning block body 3461, a tapered positioning hole 3462, and a compression spring 3463. The tapered positioning hole 3462 is opened on the lower end face of the positioning block body 3461, and the compression spring 3463 is fixedly installed on both sides of the positioning block body 3461. Before the bolt rotates, the tapered positioning hole 3462 accommodates the end of the bolt and guides the bolt to slide along the tapered surface, so that the bolt and nut are aligned; the compression spring 3463 provides elastic floating support for the positioning block body 3461, so that the bolt obtains flexible compensation when it contacts the tapered positioning hole 3462, which helps to avoid rigid impact damage to the threads.

[0025] like Figure 6 As shown, the bolt mounting fixture 33 includes a fixture mounting post 331 and a bolt fixture body 333. A taper 332 is fixedly mounted on the upper end face of the fixture mounting post 331. When the bolt approaches the nut along with the upper clamping device 3, the taper 332 engages with the tapered positioning hole 3462, guiding the bolt to be axially aligned, ensuring that the bolt axis is consistent with the nut axis during clamping and testing.

[0026] like Figure 6 , Figure 7As shown, the bolt mounting fixture 33 also includes an anti-offset structure 334 and an anti-bolt rotation structure 335. The anti-offset structure 334 is fixedly installed between the fixture mounting column 331 and the bolt fixture body 333, and is used to limit the radial offset of the bolt relative to the bolt mounting fixture 33, so that the bolt maintains a stable axial posture during conveying and centering. The anti-bolt rotation structure 335 is installed on both sides of the bolt mounting position 336, including an inner low-pressure rod 3351 and an outer low-pressure rod 3352, and a bolt anti-rotation block 3361 is provided at the bolt mounting position 336. One end of the inner low-pressure rod 3351 is fixedly installed on one side of the bolt anti-rotation block 3361, and the outer low-pressure rod 3352 is sleeved on the outside of the inner low-pressure rod 3351. A spring is also provided between the inner low-pressure rod 3351 and the outer low-pressure rod 3352. The anti-bolt rotation structure 335 holds the bolt against it with low pressure from both sides, and the bolt anti-rotation block 3361 prevents the bolt from rotating at the bolt installation position 336, thereby limiting the bolt rotation during the bolt alignment process and preventing misalignment and screwing when the bolt is not aligned. Example

[0027] like Figure 4 As shown, based on Embodiment 1, the clamping structure 34 includes a hydraulic rod 342, a power slider 344, and a clamping block 345. The hydraulic rod 342 is connected to the clamping block 345 via the power slider 344. When the hydraulic rod 342 extends or retracts, it drives the power slider 344 to move, thereby driving the clamping block 345 to move radially along the bolt to clamp or release the bolt. The clamping block 345 includes a clamping block body 3452, on which a guide groove 3451 is provided. A clamping groove 3453 is installed on the inner side of the clamping block body 3452. The clamping block 345 is guided and slidable through the guide groove 3451, and the clamping groove 3453 cooperates with the outer peripheral surface of the bolt to clamp the bolt. The clamping structure 34 is also provided with a sealing plate 341, a piston seal 343, and a sealing sleeve 349. The piston seal 343 is sleeved on the outer periphery of the piston of the hydraulic rod 342, the sealing sleeve 349 is located below the piston seal 343, and the sealing plate 341 is located below the sealing sleeve 349 to ensure the sealing of the moving parts of the hydraulic rod 342. The squeezing block 347 is located below the clamping block 345 to assist the clamping block 345 in completing the clamping and releasing actions.

[0028] like Figure 3 As shown, the rotating structure 35 is connected to the bolt mounting fixture 33 via a transmission connection. When the rotating structure 35 is in motion, it drives the bolt mounting fixture 33 and the bolt to rotate around the bolt axis. During the rotation, the clamping structure 34 maintains the clamping of the bolt, ensuring that the rotation is reliably transmitted to the bolt, so that the bolt is screwed into the nut axially to complete the automatic fitting and clamping. Subsequently, the lifting structure applies axial tension to conduct a tensile test. Example

[0029] like Figure 8 , Figure 9 As shown, based on Embodiment 1, the lower clamp 4 includes a lower clamp body 41 and a lower bolt mounting fixture 42 disposed on the lower clamp body 41. The lower clamp body 41 is fixedly mounted on the upper end face of the base 5. The lower bolt mounting fixture 42 includes a bolt mounting bracket body 421, an anti-rotation nut mounting position 422, and a bolt guide hole 423. The bolt mounting bracket body 421 is fixedly mounted on the upper end face of the tapered mounting post 424. The anti-rotation nut mounting position 422 is located at the center of the bolt mounting bracket body 421, and the bolt guide hole 423 is installed on the upper end face of the anti-rotation nut mounting position 422. The anti-rotation nut mounting position 422 is configured with the same external contour as the bolt to accommodate the nut and restrict its rotation. The bolt guide hole 423 is used to guide the bolt to enter the nut axially. The lower bolt mounting fixture 42 also has a mounting post fixing structure 425, which is used to fix the tapered mounting post 424 to the bolt mounting bracket body 421.

[0030] like Figure 1 As shown, the lifting frame 1 is fixedly installed on the upper surface of the base 5, the lifting mounting plate 2 is slidably mounted on the lifting frame 1, and the upper clamping device 3 is mounted on the lower surface of the lifting mounting plate 2. The lifting mounting plate 2 drives the upper clamping device 3 to move up and down along the lifting frame 1, so that the bolt approaches the nut axially and is screwed into the nut. After the bolt is screwed into the nut, an axial tensile force is applied to the bolt and the nut to complete the tensile test.

[0031] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A tensile strength testing machine for electric vehicle bolts, comprising a base (5), characterized in that: A lower clamp (4) is provided on the base (5) for positioning the nut and restricting the rotation of the nut; and an upper clamp (3) is provided opposite to the lower clamp (4) for clamping the bolt. A lifting mounting plate (2) is fixedly installed on the upper end face of the upper clamp (3), and the lifting mounting plate (2) is slidably installed on the lifting frame (1). The upper clamping device (3) includes a bolt mounting clamp (33) for clamping the bolt, a clamping structure (34) for clamping the bolt and aligning the bolt with the nut, and a rotating structure (35) for driving the bolt to rotate about its own axis; wherein, the clamping structure (34) aligns the bolt with the nut before the bolt rotates, and the rotating structure (35) drives the bolt to rotate while the lower clamp (4) restricts the rotation of the nut, so that the bolt is screwed into the nut to achieve automatic engagement, and the upper clamping device (3) and the lower clamp (4) move relative to each other along the axial direction after the bolt is screwed into the nut, applying axial tension to the bolt and the nut to conduct a tensile test; The upper clamping device (3) also includes a flange (31) whose upper end face is fixedly connected to the lifting mounting plate (2). A rotating structure (35) is fixedly installed on the lower end face of the flange (31). A clamping shell (32) is fixedly installed on the lower end face of the rotating structure (35). A clamping structure (34) is installed inside the clamping shell (32). The clamping structure (34) clamps a bolt mounting fixture (33).

2. The electric vehicle bolt tensile strength testing machine according to claim 1, characterized in that: The clamping structure (34) includes a centering positioning block (346) fixedly installed on the lower end face of the compression release push rod (348). The centering positioning block (346) includes a positioning block body (3461), a tapered positioning hole (3462) opened on the lower end face of the positioning block body (3461), and compression springs (3463) fixedly installed on both sides of the positioning block body (3461).

3. The electric vehicle bolt tensile strength testing machine according to claim 1, characterized in that: The bolt mounting fixture (33) includes a fixture mounting post (331), and a taper (332) is fixedly mounted on the upper end face of the fixture mounting post (331). The taper (332) cooperates with the tapered positioning hole (3462) to guide the bolt to be centered along the axial direction.

4. The electric vehicle bolt tensile strength testing machine according to claim 3, characterized in that: The bolt mounting fixture (33) further includes an anti-offset structure (334) fixedly installed between the fixture mounting post (331) and the bolt fixture body (333) and an anti-bolt rotation structure (335) installed on both sides of the bolt mounting position (336). The anti-offset structure (334) is used to limit the radial offset of the bolt relative to the bolt mounting fixture (33), and the anti-bolt rotation structure (335) is used to limit the rotation of the bolt during the alignment of the bolt and the nut, so as to avoid misalignment and screwing when the bolt is not aligned.

5. The electric vehicle bolt tensile strength testing machine according to claim 4, characterized in that: The anti-bolt rotation structure (335) includes an inner low-pressure rod (3351) and an outer low-pressure rod (3352). The bolt mounting fixture (33) is provided with a bolt mounting position (336). A bolt anti-rotation block (3361) is provided at the bolt mounting position (336). One end of the inner low-pressure rod (3351) is fixedly installed on one side of the bolt anti-rotation block (3361). The outer low-pressure rod (3352) is sleeved on the outside of the inner low-pressure rod (3351). A spring is also provided between the inner low-pressure rod (3351) and the outer low-pressure rod (3352). The anti-bolt rotation structure (335) is used to hold the bolt against the bolt with low pressure from both sides of the bolt, and the bolt anti-rotation block (3361) is used to prevent the bolt from rotating at the bolt installation position (336).

6. The electric vehicle bolt tensile strength testing machine according to claim 1, characterized in that: The clamping structure (34) includes a hydraulic rod (342) and a clamping block (345). The hydraulic rod (342) drives the clamping block (345) to move radially along the bolt via a power slider (344) to clamp or release the bolt.

7. The electric vehicle bolt tensile strength testing machine according to claim 6, characterized in that: The clamping block (345) includes a clamping block body (3452), a guide groove (3451) disposed on the clamping block body (3452), and a clamping groove (3453) installed on the inner side of the clamping block body (3452). The clamping block (345) slides guided by the guide groove (3451).

8. The electric vehicle bolt tensile strength testing machine according to claim 1, characterized in that: The rotating structure (35) is connected to the bolt mounting fixture (33) for driving the bolt mounting fixture (33) and the bolt to rotate around the axis of the bolt. When the rotating structure (35) drives the bolt to rotate, the clamping structure (34) maintains the clamping of the bolt.

9. The electric vehicle bolt tensile strength testing machine according to claim 1, characterized in that: The lower clamp (4) includes a lower clamp body (41) fixedly installed on the upper end face of the base (5) and a lower bolt mounting fixture (42) disposed on the lower clamp body (41). The lower bolt mounting fixture (42) includes a bolt mounting bracket body (421) fixedly installed on the upper end face of the tapered mounting column (424), an anti-rotation nut mounting position (422) disposed at the center of the bolt mounting bracket body (421), and a bolt guide hole (423) disposed on the upper end face of the anti-rotation nut mounting position (422). The anti-rotation nut mounting position (422) is configured to have the same external contour as the bolt.

10. A tensile strength testing machine for electric vehicle bolts according to claim 1, characterized in that: It also includes a lifting frame (1) and a lifting mounting plate (2). The lifting mounting plate (2) is slidably disposed on the lifting frame (1). The upper clamping device (3) is disposed on the lower end face of the lifting mounting plate (2). The lifting mounting plate (2) drives the upper clamping device (3) to move up and down along the lifting frame (1) so that the bolt approaches the nut axially and is screwed into the nut. After the bolt is screwed into the nut, an axial tensile force is applied to the bolt and the nut.

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