Nut detection and positioning mechanism

Abstract

The utility model relates to the technical field of automobile production frock, especially a nut detection and positioning mechanism, including the telescopic component that can stretch out and draw back before and after, install and connect on the telescopic component and can with the telescopic component together telescopic intermediate connecting seat, still install and connect on the intermediate connecting seat have proximity switch and can trigger the trigger subassembly of proximity switch, proximity switch with trigger the subassembly can follow the telescopic of intermediate connecting seat together, high and safe.

Description

Technical Field

[0001] This utility model relates to the field of automotive manufacturing tooling technology, and in particular to a nut detection and positioning mechanism. Background Technology

[0002] On existing automotive production lines, workpieces with nuts installed are subject to inspection to ensure correct installation. Leakage detection devices are used to prevent issues such as incomplete welding of the nuts. These typically employ proximity switches for direct sensing, detecting the nut's location based on its sensing area and effective distance. If such a nut welding problem occurs during vehicle production, it will directly lead to the scrapping of the entire car body, making the reliability of the inspection crucial. Of course, many existing inspection devices already exist.

[0003] For example, Chinese Patent Application No. 201310283809.5 discloses a leak-proof detection device and method for a welding nut clamp, including an interference pin, a guide device, and a proximity switch. The interference pin is longitudinally retractable, used to contact the nut, and can be pressed downwards. The guide device is connected below the interference pin; the interference pin is connected above the guide device and can be driven downwards by the interference pin. The proximity switch includes a sensing device that can sense the downward-moving guide device. When an assembly with a welding nut is moved onto the clamp, the inner diameter of the nut contacts the positioning pin of the leak-proof detection device, causing the positioning pin to move downwards under force, driving the guide shaft downwards. After the proximity switch senses the guide shaft, the proximity switch indicator light illuminates, the clamp interlock device unlocks, and clamping and welding of the assembly can be performed. Conversely, if no nut is detected, the circuit interlocks, and operation is impossible.

[0004] For example, Chinese Patent Application No. 201520064259.2 discloses a leak-proof detection device for welding automotive nuts, comprising: a contact, the contact being frustum-shaped with a cross-sectional diameter matching that of the automotive nut; a telescopic shaft, cylindrical in shape, fixedly connected to the contact and a first piston; a cylinder, hollow cylindrical in shape, with a space inside to accommodate the axial movement of the first piston, a pair of first stops on the inner wall of the cylinder, and a pipe extending radially from the lower part of the cylinder, with a second piston disposed in the pipe; a base, having a groove to accommodate and fix the cylinder and the pipe; and a proximity switch, the sensor of which corresponds to the other end of the pipe and does not contact the second piston. The first piston, the second piston, the cylinder, and the pipe form a closed space.

[0005] The existing inspection devices all have fixed proximity switches, which are passive detection structures. The workpiece needs to be brought close for detection, so that the workpiece actively moves. This poses a lot of production risks during the workpiece movement process, and requires more workpiece movements to achieve the desired result, which also affects production efficiency. Utility Model Content

[0006] The purpose of this invention is to provide a highly efficient and safe nut detection and positioning mechanism.

[0007] The above-mentioned objective of this utility model is achieved through the following technical solution: a nut detection and positioning mechanism, comprising a telescopic component that can extend and retract back and forth, an intermediate connecting seat that is installed and connected to the telescopic component and can extend and retract together with the telescopic component, a proximity switch and a triggering component that can trigger the proximity switch are also installed and connected on the intermediate connecting seat, and the proximity switch and the triggering component can extend and retract together with the intermediate connecting seat.

[0008] As a preferred embodiment of this utility model, the intermediate connecting seat includes front and rear connecting sections extending forward and backward, and an upwardly extending upper connecting section integrally connected to the front and rear connecting sections. The front and rear connecting sections and the upper connecting section intersect to form an inverted T-shaped structure. The upper connecting section is opened from top to bottom to form an upper mounting channel for the proximity switch to be installed and connected. The front and rear connecting sections are opened from front to back to form a front mounting channel for the trigger component to be installed and connected.

[0009] As a preferred embodiment of this utility model, the proximity switch with the sensing head is inserted into the upper mounting channel, and the triggering component includes a fixed connecting sleeve that extends forward and backward and is inserted into the front mounting channel. A trigger terminal for triggering the sensing head is installed in the fixed connecting sleeve and can elastically extend and retract relative to the fixed connecting sleeve.

[0010] As a preferred embodiment of this invention, the trigger terminal is located in front of the sensing head, and the rear side of the front mounting channel is connected to the lower side of the upper mounting channel, with the two intersecting in an L-shape.

[0011] As a preferred embodiment of this utility model, an annular expansion sleeve is embedded in the upper mounting channel, the portion of the proximity switch with the sensing head passes through the inner ring of the expansion sleeve, and an expansion compression bolt that abuts against the outer wall of the expansion sleeve from the outside to the inside passes through the side wall of the upper connecting section.

[0012] As a preferred embodiment of this utility model, the fixed connecting sleeve is fixed in the front mounting channel, and a detection rod that can extend and retract relative to the fixed connecting sleeve is sleeved inside the fixed connecting sleeve. The detection rod includes a front detection column and a rear detection column that are integrally connected front and rear. The front detection column and the rear detection column are coaxial, and the diameter of the front detection column is larger than that of the rear detection column. A detection pin is fixed at the front end of the front detection column, and the trigger terminal is fixed at the rear end of the rear detection column.

[0013] As a preferred embodiment of this utility model, a front channel, a middle channel, and a rear channel are sequentially formed from front to back within the fixed connecting sleeve. The diameter of the front channel is larger than that of the middle channel, and the diameter of the middle channel is smaller than that of the rear channel. A buffer reset spring extending forward and backward is sleeved around the rear detection post. The buffer reset spring is located within the front channel. The outer diameter of the buffer reset spring is larger than that of the middle channel, and the inner diameter of the buffer reset spring is smaller than that of the front detection post. The front end of the buffer reset spring abuts against the annular step formed at the integral connection between the front and rear detection posts, and the rear end of the buffer reset spring abuts against the annular step formed at the connection point between the front and middle channels on the fixed connecting sleeve.

[0014] As a preferred embodiment of this utility model, a portion of the front detection post exists within the front channel and a portion extends forward out of the front channel, and the rear detection post is at least inserted into the front channel and the middle channel. The trigger terminal includes a connecting rod and a trigger head integrally connected at the front and rear. The connecting rod is fixed in the rear end portion of the rear detection post, and the diameter of the trigger head is larger than the diameter of the middle channel and can move back and forth in the rear channel.

[0015] As a preferred embodiment of this utility model, it further includes a front guide mounting block through which the fixed connecting sleeve passes and moves back and forth, a rear mounting block for mounting and fixing the telescopic component, and a positioning mounting block integrally connected between the left side or the right side of the front guide mounting block and the rear mounting block, wherein the positioning mounting block is provided with a positioning hole.

[0016] As a preferred embodiment of this utility model, the telescopic component is a cylinder or a hydraulic cylinder and includes a cylinder body and a piston rod. The cylinder body is fixed at the rear side of the rear mounting block and the piston rod passes forward through the rear mounting block. The front end of the piston rod is connected to the rear end of the front and rear connecting sections. A guide sleeve for the fixed connecting sleeve to pass through is embedded and fixed on the front guide mounting block.

[0017] The beneficial effects of this utility model are as follows: The detection mechanism of this application actively extends and retracts to perform active nut detection, reducing the detection path that workpieces on the production line must take in order to detect nuts, thus increasing efficiency; it reduces the energy consumption of moving large workpieces and can prevent some defective parts from falling off during the detection movement and colliding with the detection mechanism, thus providing better protection; moreover, it can also detect moving workpieces directly, and immediately retreat after detection, and can immediately provide feedback on the detection results, allowing the production line to promptly handle workpieces with improperly installed nuts or missing nuts, resulting in a greater improvement in efficiency. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the detection mechanism in the embodiment;

[0019] Figure 2 yes Figure 1 A schematic diagram of the three-dimensional structure from a frontal perspective;

[0020] Figure 3 yes Figure 1 A three-dimensional structural diagram after removing the three mounting blocks from the central structure;

[0021] Figure 4 yes Figure 3 A three-dimensional structural diagram from a rear view;

[0022] Figure 5 yes Figure 3 A three-dimensional structural diagram of the central structure after the guide bushing is removed;

[0023] Figure 6 yes Figure 3 A three-dimensional structural diagram after the intermediate connecting seat is removed from the central structure;

[0024] Figure 7 yes Figure 6 A three-dimensional structural diagram of the central structure after the guide bushing is removed;

[0025] Figure 8 yes Figure 5 A three-dimensional structural diagram of the intermediate connecting seat in the middle;

[0026] Figure 9 yes Figure 8 A schematic diagram of the three-dimensional structure from an upper perspective;

[0027] Figure 10 yes Figure 7 A three-dimensional structural diagram of the central structure after the fixed connecting sleeve is removed;

[0028] Figure 11 yes Figure 7 A cross-sectional view of the middle structure after being cut along a vertical plane passing through the axis of the fixed connecting sleeve;

[0029] Figure 12 yes Figure 7 A three-dimensional structural diagram of the fixed connecting sleeve in the middle;

[0030] Figure 13 yes Figure 12 A three-dimensional structural diagram from a rear view;

[0031] Figure 14 yes Figure 1 A cross-sectional view of the middle structure after being cut along a vertical plane passing through the axis of the fixed connecting sleeve. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the accompanying drawings.

[0033] This specific embodiment is merely an explanation of the present utility model and is not intended to limit the present utility model. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of the present utility model.

[0034] Examples, such as Figure 1-14 As shown, a nut detection and positioning mechanism includes a telescopic component that can extend and retract, and an intermediate connecting seat 1 installed on the telescopic component and extending and retracting together with it. A proximity switch 2 and a triggering component that can trigger the proximity switch 2 are also installed on the intermediate connecting seat 1. The proximity switch 2 and the triggering component can extend and retract together with the intermediate connecting seat 1. Through the design of the intermediate connecting seat 1, the proximity switch 2, the telescopic component, and the triggering component are connected together via a three-way connection. This allows the intermediate connecting seat 1 to extend and retract with the action of the telescopic component, enabling the proximity switch 2 and the triggering component to extend and retract together, forming an active detection method to check whether the nut on the workpiece is installed correctly or if any part is missing. This active method is more efficient and reliable.

[0035] Specifically, the intermediate connecting seat 1 includes front and rear connecting sections 11 extending forward and backward, and an upwardly extending upper connecting section 12 integrally connected to the front and rear connecting sections 11. The front and rear connecting sections 11 and the upper connecting section 12 intersect to form an inverted T-shaped structure. The upper connecting section 12 forms an upper mounting channel 120 from top to bottom for mounting the proximity switch 2. The front and rear connecting sections 11 form a front mounting channel 110 from front to back for mounting the trigger component. The intermediate connecting seat 1 provides a supporting mounting component for intermediate bearing and transition. The rear end of the front and rear connecting sections 11 is connected to the telescopic component, the upper middle part is connected to the proximity switch 2, and the front side is connected to the trigger component. This triangular structure has good stability and is the basic architecture of the entire detection structure. The intermediate connecting seat 1 is made of metal, such as steel, to ensure structural strength.

[0036] Furthermore, the portion of the proximity switch 2 with the sensing head 21 is inserted and installed into the upper mounting channel 120, with the sensing head 21 positioned at the lowest point of the proximity switch 2. The triggering assembly includes a front-to-back extending fixed connecting sleeve 3 inserted and installed into the front mounting channel 110. A trigger terminal 31, capable of elastic expansion and contraction relative to the fixed connecting sleeve 3, is installed within the fixed connecting sleeve 3 to trigger the sensing head 21. The outer wall of the rear portion of the fixed connecting sleeve 3 may have external threads, while the inner wall of the front mounting channel 110 may have internal threads. Thus, the front fixed connecting sleeve 3 is directly screwed into the front mounting channel 110 via the internal and external threads. Alternatively, other existing methods can be used for installation. The front fixed connecting sleeve 3 extends forward out of the front mounting channel 110. The trigger terminal 31 within it is used to trigger the sensing head 21, causing the proximity switch 2 to generate a corresponding signal. Specifically, when the telescopic component moves the intermediate connecting seat 1 forward, the proximity switch 2 and the trigger component move forward together. The trigger component approaches the workpiece being detected and enters the nut detection position. If a nut is present, the trigger terminal 31 in the trigger component will retract. The accuracy of the nut position is detected based on the degree of retraction. The displacement of the trigger terminal 31 causes the sensing head 21 to react, thereby generating the existing trigger signal of the proximity switch. Of course, if there is no nut, there is no corresponding feedback, and the proximity switch will issue a signal indicating that there is no nut. In this structure, the feedback is relatively timely and the accuracy is relatively reliable. The flexible structure also provides better protection.

[0037] Preferably, the trigger terminal 31 is located in front of the sensing head 21, and the rear side of the front mounting channel 110 is connected to the lower side of the upper mounting channel 120 and the two intersect in an L-shape. This arrangement provides sufficient space in the intermediate connecting seat 1 to arrange the sensing head 21 and the trigger terminal 31, and also has a reasonable position design. Since the trigger component performs detection on the front side and feeds back to the proximity switch in the middle position, while the rear side is the telescopic detection drive part, a complete detection chain is formed, which is very logical and practical.

[0038] Furthermore, an annular expansion sleeve z is embedded within the upper mounting channel 120. The sidewall of the expansion sleeve z has a conventional structure with an expansion slot that connects vertically. The upper mounting channel 120 is preferably cylindrical, and the original outer diameter of the expansion sleeve z is kept as consistent as possible with the hole diameter of the upper mounting channel 120. However, for actual assembly, the outer diameter of the expansion sleeve z will be slightly smaller than the hole diameter of the upper mounting channel 120 to facilitate insertion. The portion of the proximity switch 2 with the sensing head 21 passes through the inner ring of the expansion sleeve z. An expansion compression bolt z1, which abuts against the outer wall of the expansion sleeve z from the outside in, passes through the sidewall of the upper connecting section 12. The original inner diameter of the inner ring of the expansion sleeve z is larger than the outer diameter of the portion of the proximity switch 2 with the sensing head 21. This facilitates the insertion of the portion of the proximity switch 2 with the sensing head 21 into the inner ring of the expansion sleeve z. Then, the expansion compression bolt z1 passes radially through the sidewall of the upper connecting section 12 and presses inward, causing the expansion sleeve z to contract and thus tighten and fix the proximity switch 2. Of course, other methods can also be used for fixing.

[0039] Preferably, as mentioned above, the fixed connecting sleeve 3 is fixed within the front mounting channel 110, and a detection rod 4 that can elastically extend and retract relative to the fixed connecting sleeve 3 is sleeved inside the fixed connecting sleeve 3. The detection rod 4 includes a front detection post 41 and a rear detection post 42 integrally connected front and rear. The front detection post 41 and the rear detection post 42 are coaxial, and the diameter of the front detection post 41 is larger than that of the rear detection post 42. A detection pin 411 is fixed to the front end of the front detection post 41. The detection pin 411 adopts an existing pin. The sensor rod 4 is fixed to the front end of the front detection column 41 using existing methods. The rear end of the rear detection column 42 is fixed with the trigger terminal 31. With the above design, the initial detection rod 4 will move forward with the fixed connecting sleeve 3 for detection. When the detection pin 411 touches the nut, the detection rod 4 cannot move forward, but the fixed connecting sleeve 3 is still moving forward. Therefore, the detection rod 4 is pushed backward. Due to the corresponding elastic structure design, it will be elastically pushed backward and moved backward, thereby driving the trigger terminal 31 to move backward and approach the sensing head 21 to trigger the sensing. When the detection ends, the fixed connecting sleeve 3 retracts, the spring resets, and the detection rod 4 is pushed forward to the initial position to return to its original position and enter the next detection stage, and so on.

[0040] Furthermore, the fixed connecting sleeve 3 has a front channel 301, a middle channel 302, and a rear channel 303 that are interconnected from front to back. Preferably, the three are coaxial. The diameter of the front channel 301 is larger than that of the middle channel 302, and the diameter of the middle channel 302 is smaller than that of the rear channel 303. This forms a stepped structure, which facilitates the support and positioning of the internal mechanism. The rear detection post 42 is surrounded by a front-to-back extending buffer return spring 420. The buffer return spring 420 is located inside the front channel 301. The outer diameter of the buffer return spring 420 is larger than the diameter of the middle channel 302, and the inner diameter of the buffer return spring 420 is smaller than the diameter of the front detection post 41. These are all cylindrical structures. Through this size design, the front end of the buffer return spring 420 abuts against the annular step formed at the integral connection of the front detection post 41 and the rear detection post 42, and the rear end of the buffer return spring 420 abuts against the annular step formed at the connection of the fixed connecting sleeve 3 at the junction of the front channel 301 and the middle channel 302. In this way, the buffer return spring 420 can be limited and supported at both ends, and the elastic extension and retraction of the aforementioned detection rod 4 can be realized.

[0041] Preferably, a portion of the front detection post 41 exists within the front channel 301 and a portion extends forward from the front channel 301, with the diameter of the front detection post 41 matching the diameter of the front channel 301. The rear detection post 42 is inserted into at least the front channel 301 and the middle channel 302, with the trigger terminal 31 fixed at the rear end of the rear detection post 42. If the connection portion of the trigger terminal 31 enters the middle channel 302, the rear detection post 42 does not need to enter the rear channel 303. Alternatively, the rear detection post 42 can also enter the rear channel 303, which would facilitate the fixing and limiting of the trigger terminal 31. The diameter of the rear detection post 42 should be smaller than the diameter of the front channel 301, but can match the diameter of the middle channel 302, thus ensuring the stability of the process and facilitating the setting of the middle channel 302.

[0042] The trigger terminal 31 includes a connecting rod 311 and a trigger head 312 integrally connected at the front and rear. The connecting rod 311 is fixed in the rear end of the rear detection post 42. The trigger terminal 31 is made of metal to trigger the proximity switch. The entire structure can be a bolt structure. A screw hole can be opened at the rear end of the rear detection post 42, and the connecting rod 311 with external threads can be screwed into the screw hole for fixation. The trigger head 312 is a screw head with a diameter larger than the diameter of the middle channel 302. This allows the trigger head 312 to be confined in the rear channel 303, and the trigger head 312 directly interacts with the sensing head. That is, the diameter of the trigger head 312 is larger than the diameter of the middle channel 302 and can move back and forth in the rear channel 303. Of course, it can extend backward into the rear channel 303 to react with the sensing head 21, but it cannot enter the middle channel 302 first, thus achieving effective confinement.

[0043] The entire testing mechanism also includes a front guide mounting block 51 through which the fixed connecting sleeve 3 passes and moves back and forth, a rear mounting block 52 for mounting and fixing the telescopic component, and a positioning mounting block 53 integrally connected between the left or right sides of the front guide mounting block 51 and the rear mounting block 52. The positioning mounting block 53 has a positioning hole 530. These structural blocks can all be made of metal steel, which serves to strengthen the structure and guide it, and also to position and install the entire testing mechanism onto the corresponding tooling or frame.

[0044] Furthermore, the telescopic component is a cylinder or hydraulic cylinder and includes a cylinder body 61 and a piston rod 62. The cylinder body 61 is fixed to the rear side of the rear mounting block 52, and the piston rod 62 passes forward through the rear mounting block 52. The cylinder body 61 can be fixed to the rear side of the rear mounting block 52 by means of a pin or welding, or other existing methods. The rear mounting block 52 has corresponding front-to-back extending holes through which the piston rod 62 passes forward, facilitating front-to-back telescopic movement. The front end of the piston rod 62 is connected to the rear end of the front-to-back connecting section 11. The connection method can use existing fixing methods, ensuring that at least the front-to-back direction is fixed, and of course, the left-to-right and up-to-down directions are also locked as much as possible to ensure structural stability.

[0045] In addition, a guide sleeve 510 for the fixed connecting sleeve 3 to pass through is embedded and fixed on the front guide mounting block 51. The front guide mounting block 51 also has a corresponding through hole, into which the front and rear extending guide sleeve 510 is placed. The guide sleeve 510 can be fixed by means of a pin that cooperates with the front guide mounting block 51. The fixed connecting sleeve 3 passes through the guide sleeve 510. The guide sleeve 510 uses an existing bushing, which facilitates guidance and reduces friction during front and rear movement. Furthermore, some reinforcing plates or other structures can be fixed to the lower and horizontal sides of the aforementioned front guide mounting block 51, rear mounting block 52, and positioning mounting block 53 to improve structural strength.

[0046] With the above design, during testing, the piston rod 62 actively extends forward, driving the intermediate connecting seat 1, proximity switch 2, fixed connecting sleeve 3, detection rod 4, and detection pin 411 forward together. When the detection pin 411 touches the nut, the detection pin 411 and detection rod 4, due to their internal elastic structure, move backward relative to the fixed connecting sleeve 3 and intermediate connecting seat 1, thereby triggering terminal 31 to activate and the sensing head to send a signal, which can determine the installation status of the nut. Of course, the piston rod stroke is preset. If there is no feedback within the preset stroke, it indicates that there is no nut, and a corresponding signal is also sent. After the test ends, the piston rod retracts, all structures reset, and the test begins for the next workpiece.

[0047] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A nut detection and positioning mechanism, characterized in that, It includes a telescopic component that can extend and retract, an intermediate connecting seat (1) that is installed on the telescopic component and can extend and retract together with the telescopic component, a proximity switch (2) and a triggering component that can trigger the proximity switch (2) are also installed on the intermediate connecting seat (1), and the proximity switch (2) and the triggering component can extend and retract together with the intermediate connecting seat (1).

2. The nut detection and positioning mechanism according to claim 1, characterized in that, The intermediate connecting seat (1) includes a front and rear connecting section (11) extending forward and backward, and an upper connecting section (12) extending upward integrally connected to the front and rear connecting section (11). The front and rear connecting section (11) and the upper connecting section (12) intersect to form an inverted T-shaped structure. The upper connecting section (12) is opened from top to bottom to form an upper mounting channel (120) for the proximity switch (2) to be installed and connected. The front and rear connecting section (11) is opened from front to back to form a front mounting channel (110) for the trigger component to be installed and connected.

3. The nut detection and positioning mechanism according to claim 2, characterized in that, The proximity switch (2) with the sensing head (21) is inserted into the upper mounting channel (120). The triggering assembly includes a fixed connecting sleeve (3) that extends forward and backward and is inserted into the front mounting channel (110). The fixed connecting sleeve (3) is equipped with a trigger terminal (31) that can elastically extend and retract relative to the fixed connecting sleeve (3) to trigger the action of the sensing head (21).

4. The nut detection and positioning mechanism according to claim 3, characterized in that, The trigger terminal (31) is located in front of the sensing head (21), and the rear side of the front mounting channel (110) is connected to the lower side of the upper mounting channel (120) and the two intersect in an L-shape.

5. The nut detection and positioning mechanism according to claim 3, characterized in that, An annular expansion sleeve (z) is embedded in the upper mounting channel (120). The portion of the proximity switch (2) with the sensing head (21) passes through the inner ring of the expansion sleeve (z). An expansion compression bolt (z1) that abuts against the outer wall of the expansion sleeve (z) from the outside to the inside passes through the side wall of the upper connecting section (12).

6. The nut detection and positioning mechanism according to claim 3, characterized in that, The fixed connecting sleeve (3) is fixed inside the front mounting channel (110). The fixed connecting sleeve (3) is fitted with a detection rod (4) that can extend and retract relative to the fixed connecting sleeve (3). The detection rod (4) includes a front detection column (41) and a rear detection column (42) that are integrally connected. The front detection column (41) and the rear detection column (42) are coaxial and the diameter of the front detection column (41) is larger than the diameter of the rear detection column (42). The front end of the front detection column (41) is fixed with a detection pin (411), and the rear end of the rear detection column (42) is fixed with the trigger terminal (31).

7. The nut detection and positioning mechanism according to claim 6, characterized in that, The fixed connecting sleeve (3) has a front channel (301), a middle channel (302), and a rear channel (303) formed sequentially from front to back, which are interconnected. The diameter of the front channel (301) is larger than that of the middle channel (302), and the diameter of the middle channel (302) is smaller than that of the rear channel (303). A buffer return spring (420) extending from front to back is sleeved around the rear detection column (42). The buffer return spring (420) is located in the front channel (301). The outer diameter of the spring (420) is larger than the diameter of the middle channel (302), the inner diameter of the buffer reset spring (420) is smaller than the diameter of the front detection post (41), the front end of the buffer reset spring (420) abuts against the annular step formed at the integral connection of the front detection post (41) and the rear detection post (42), and the rear end of the buffer reset spring (420) abuts against the annular step formed at the connection of the fixed connecting sleeve (3) at the junction of the front channel (301) and the middle channel (302).

8. The nut detection and positioning mechanism according to claim 7, characterized in that, The front detection post (41) is partially located within the front channel (301) and partially extends forward out of the front channel (301). The rear detection post (42) is at least located in the front channel (301) and the middle channel (302). The trigger terminal (31) includes a connecting rod (311) and a trigger head (312) integrally connected at the front and rear. The connecting rod (311) is fixed in the rear end of the rear detection post (42). The diameter of the trigger head (312) is larger than the diameter of the middle channel (302) and can move back and forth in the rear channel (303).

9. A nut detection and positioning mechanism according to claim 6, characterized in that, It also includes a front guide mounting block (51) through which the fixed connecting sleeve (3) passes and moves back and forth, a rear mounting block (52) for mounting and fixing the telescopic component, and a positioning mounting block (53) integrally connected between the left side or the right side of the front guide mounting block (51) and the rear mounting block (52), wherein the positioning mounting block (53) is provided with a positioning hole (530).

10. A nut detection and positioning mechanism according to claim 9, characterized in that, The telescopic assembly is a cylinder or a hydraulic cylinder and includes a cylinder body (61) and a piston rod (62). The cylinder body (61) is fixed at the rear side of the rear mounting block (52) and the piston rod (62) passes forward through the rear mounting block (52). The front end of the piston rod (62) is connected to the rear end of the front and rear connecting section (11). A guide bushing (510) for the fixed connecting sleeve (3) to pass through is embedded and fixed on the front guide mounting block (51).

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