A pull-rivet nut mounting mechanism

Abstract

The application discloses a pull-rivet-nut mounting mechanism which comprises a shell, the shell comprising an axially extending inner cavity; a rivet nose fixedly arranged at a first end of the shell, the side of the rivet nose facing the nut being attached to a flange part; a rotating mechanism comprising a shaft body and a guide sleeve; the shaft body being axially arranged through the inner cavity and the rivet nose, and the guide sleeve being axially arranged outside the shaft body; a traction mechanism arranged outside the rotating mechanism and in the inner cavity, so that the traction mechanism can reciprocate in the inner cavity in the axial direction under the driving of an external oil cylinder; wherein in the inner cavity, the traction mechanism comprises a first step, the rotating mechanism comprises a second step, and a spring is arranged between the first step and the second step. Through the structure of the application, the guide sleeve in the rotating mechanism can be extended outside the rivet nose, the nut and the rivet nose can be separated, and the adjustment of the angle of the nut can be realized accurately, quickly and at low cost.

Description

Technical Field

[0001] This invention relates to a rivet nut mounting mechanism, belonging to the field of fastener mounting technology. Background Technology

[0002] The description in this section provides only background information related to the disclosure of this invention and does not constitute prior art.

[0003] Rivet nuts, also known as rivet nuts or rivet caps, are fasteners used for thin metal sheets, thin tubes, and other materials. They require no tapping or welding, offering easy and secure installation. Rivet nuts are widely used in the automotive, aerospace, electronics, construction, machinery manufacturing, and furniture manufacturing industries. Especially in thin-walled riveting, sealing riveting, and single-sided riveting applications, rivet nuts provide a high-strength, easy-to-install and disassemble, and reusable connection solution. Installing rivet nuts typically requires a pneumatic or manual rivet nut installation mechanism. During installation, ensure the nut is perpendicular to the workpiece being riveted and check that the shaft of the rivet nut installation mechanism matches the nut's dimensions. When using a rivet nut installation mechanism, the nut is longitudinally compressed, creating a bulge deformation on its end surface, thereby clamping the riveted objects and achieving a secure riveting effect.

[0004] In existing rivet nut installation mechanisms, after picking up the nut, the rivet lugs used to abut the nut flange are tightly pressed together under the action of torque and friction, so the nut cannot be rotated again. However, in actual use, it is often necessary to adjust the angle of the nut. For example, the shank of a hexagonal nut needs to be aligned with the angle of the matching hole. The existing method is to rotate the entire rivet nut installation mechanism by using a robot or adding an auxiliary mechanism. However, the robot or the method of rotating the entire device has a large cumulative error, resulting in poor accuracy of the nut insertion hole, low efficiency, and easy deformation or scrapping of the hexagonal hole. The effect is not good, and an additional device is required to rotate the nut, which is costly and structurally complex.

[0005] Currently, there is no rivet nut installation mechanism that can solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a rivet nut mounting mechanism that can separate the nut from the rivet nose by having a guide sleeve in the rotating mechanism extend outward from the rivet nose, thereby enabling precise, fast, and low-cost adjustment of the nut angle.

[0007] To achieve the above objectives, the present invention discloses a rivet nut mounting mechanism for mounting a nut to a plate that matches the nut, wherein the nut includes a flange portion and a rod portion, and the rod portion includes an internal thread; comprising:

[0008] A housing, the housing including an axially extending inner cavity, the housing having a first end facing the nut, the housing having a second end away from the nut, wherein the first direction is a direction extending from the second end of the housing toward the first end, and the second direction is a direction extending from the first end of the housing toward the second end;

[0009] A rivet nose is fixedly disposed at the first end of the outer casing, and the side of the rivet nose facing the nut is fitted with the flange portion;

[0010] A rotating mechanism, comprising a shaft and a guide sleeve; the shaft passes axially through the inner cavity and the rivet nose, and at least a portion of the shaft extends outward toward the outside of the rivet nose in the first direction; the guide sleeve is sleeved and fixed to the outside of the shaft along the axial direction; before the rivet nose is engaged with the flange, the side of the guide sleeve facing the nut can engage with the flange.

[0011] A traction mechanism is sleeved on the outside of the rotating mechanism and disposed in the inner cavity. At least a portion of the outer wall of the traction mechanism matches the inner wall of the inner cavity, so that the traction mechanism can reciprocate along the axial direction in the inner cavity under the drive of an external hydraulic cylinder.

[0012] In the inner cavity, the traction mechanism includes a first step, and the rotation mechanism includes a second step. The first step and the second step are arranged opposite to each other, and a spring is provided between the first step and the second step. The two ends of the spring abut against the first step and the second step, respectively.

[0013] Furthermore, when the spring is in a relaxed state, at least a portion of the guide sleeve extends outward from the rivet nose toward the first direction side.

[0014] Furthermore, when the spring is in a compressed state, the side of the guide sleeve facing the nut can be flush with the side of the rivet nose facing the nut.

[0015] Furthermore, the shaft includes a mandrel, a first coupling, and a drive shaft. The mandrel is disposed on the side of the shaft facing the first direction, the drive shaft is disposed on the side of the shaft facing the second direction, the first coupling is disposed between the mandrel and the drive shaft, and both ends of the first coupling are respectively connected to the mandrel and the drive shaft for transmission.

[0016] Furthermore, the traction mechanism includes a spindle fastening nut, which is disposed on the side of the traction mechanism facing the first direction. The side of the spindle fastening nut facing the guide sleeve includes a first buckle, and the guide sleeve includes a second buckle that matches the first buckle. The first buckle and the second buckle are disposed opposite to each other.

[0017] Furthermore, the first buckle faces the side in the second direction, and the second buckle faces the side in the first direction.

[0018] Furthermore, the first step faces the first direction, and the second step faces the second direction.

[0019] Furthermore, the outer side of the rivet nose facing the second direction includes external threads, and the rivet nose facing the second direction passes through and is fixed in the inner cavity.

[0020] By employing the above technical solutions, the beneficial effects of the present invention are as follows:

[0021] 1. The rivet nut installation mechanism of the present invention can separate the flange of the nut from the rivet nose used to abut the flange during installation by means of a guide sleeve that can extend and retract axially on the rotating mechanism. This avoids the problem that the nut cannot rotate first due to excessive friction between the rivet nose and the flange. Thus, the nut can be rotated and adjusted without obstruction by the rotating mechanism before installation. Compared with the need to use a robotic arm or rotate the entire mechanism, the present invention has higher precision and lower cost.

[0022] 2. The top of the rivet nut mounting mechanism of the present invention includes a spring for abutting the guide sleeve, so that the spring can push the guide sleeve out before pressing, and the spring can be compressed when pressing to make the guide sleeve and the rivet nose flush, and the spring extends and automatically resets the guide sleeve after pressing. The above structure is simple and responsive, which can improve the installation efficiency. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a sectional view of a rivet nut mounting mechanism provided in the embodiments of this specification;

[0025] Figure 2This is a schematic diagram of the working scenario of a rivet nut mounting mechanism provided in the embodiments of this specification;

[0026] Figure 3 This is a schematic diagram of a rotary motor drive for a rivet nut mounting mechanism provided in the embodiments of this specification;

[0027] Figure 4 This is a side view of a rivet nut mounting mechanism provided in the embodiments of this specification;

[0028] In the diagram: 100, hexagonal nut; 1, outer casing; 2, rivet nose; 3, rotating mechanism; 31, shaft; 311, mandrel; 312, first coupling; 313, drive shaft; 314, second coupling; 315, auxiliary rangefinder; 32, guide sleeve; 321, second snap-fit; 33, second step; 4, traction mechanism; 41, first step; 42, mandrel fastening nut; 421, first snap-fit; 5, spring; 6, vision system; 7, rotating feeding mechanism; 8, rotating motor. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0030] In the description of this invention, it should be noted that the terms "upper," "middle," "lower," "inner," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The embodiments of this invention will now be described according to its overall structure.

[0031] Please see Figure 1 This embodiment provides a rivet nut mounting mechanism for mounting a nut to a plate that matches the nut. The nut includes a flange and a shank, the shank including an internal thread. The mechanism includes:

[0032] The housing 1 includes an axially extending inner cavity 11, the housing 1 has a first end facing the nut, and the housing 1 has a second end away from the nut, wherein the first direction is the direction extending from the second end of the housing 1 to the first end, and the second direction is the direction extending from the first end of the housing 1 to the second end; the rivet 2 is fixedly disposed at the first end of the housing 1, and the side of the rivet 2 facing the nut is in contact with the flange portion.

[0033] The rotating mechanism 3 includes a shaft 31 and a guide sleeve 32. The shaft 31 passes through the inner cavity 11 and the rivet nose 2 along the axial direction, and at least a portion of the shaft 31 extends to the outside of the rivet nose 2 in a first direction. The guide sleeve 32 is sleeved and fixed to the outside of the shaft 31 along the axial direction. Before the rivet nose 2 is fitted with the flange, the side of the guide sleeve 32 facing the nut can fit with the flange.

[0034] The traction mechanism 4 is sleeved on the outside of the rotating mechanism 3 and is located in the inner cavity. At least part of the outer wall of the traction mechanism 4 matches the inner wall of the inner cavity 11 so that the traction mechanism 4 can reciprocate along the axial direction in the inner cavity 11 under the drive of the external hydraulic cylinder.

[0035] In the inner cavity 11, the traction mechanism 4 includes a first step 41 and the rotation mechanism 3 includes a second step 33. The first step 41 and the second step 33 are arranged opposite to each other. A spring 5 is arranged between the first step 41 and the second step 33. The two ends of the spring 5 abut against the first step 41 and the second step 33 respectively.

[0036] Based on the above structure, please refer to Figure 1-2In use, the rotary feeding mechanism 7 can be used to initially position and clamp the nuts blown in by the vibratory plate. Then, the rotary feeding mechanism 7 rotates and moves the nut to directly below the rivet nut mounting mechanism in the first direction of this embodiment, and directly above the mounting plate. At this time, the shaft 31 of the rotary mechanism 3 aligns with the rod of the nut and moves towards the nut under the drive of an external servo motor (in another embodiment, the external servo motor can also drive the rotary feeding mechanism 7 to move towards the shaft 31, the principle is the same), and drives the shaft 31 to rotate, so that the external thread at one end of the shaft 31 is threadedly connected to the internal thread of the rod. Then, the rotary feeding mechanism 7 rotates away and performs the next cycle operation. At this time, the shaft 31 is threaded through and connected to the rod. Since a guide sleeve 32 is provided around the shaft 31, the shaft 31, in the second direction away from the nut, experiences a force from the spring 5 acting towards the nut in the first direction. Therefore, the guide sleeve 32, fixedly provided on the outside of the shaft 31, partially extends outward from the rivet nose 2 under the force of the spring 5. In other words, the side of the rivet nose 2 facing the first direction does not contact the flange of the nut at this time, and there is no frictional obstruction between the rivet nose 2 and the flange of the nut. The vision system 6 then intervenes, taking pictures to identify the direction of the nut and the angle of the hole on the plate to be fixed. Then, the offset angle of the nut relative to the hole is sent to the servo motor connected to the PLC system to drive the rivet nut mounting mechanism. This allows the servo motor to drive the shaft 31 directly and unobstructedly, rotating the nut and achieving angle adjustment. After the angle adjustment is completed, the servo motor drives the rotating mechanism to precisely insert the nut rod into the hole of the plate. One side of the guide sleeve 32 first presses against the flange, and the flange is placed on the plate with its side facing the plate. Then the servo motor continues to apply force towards the plate, and the spring is compressed until the rivet nose 2 is also completely attached to the flange. Under the force of the rivet nose 2, the flange is completely attached to the plate, thus realizing the conditions for the final riveting.

[0037] In the above process, this embodiment uses a guide sleeve 32 of the rotating mechanism 3. The shaft 31 has a spring 5 on one side in the second direction that can abut against it. This spring 5 provides force to the guide sleeve 32, which is located outside the shaft 31, towards the first direction. This ensures that before riveting, when the shaft 31 is initially threaded into the nut, only the side of the guide sleeve 32 facing the nut is attached to the flange of the nut. The force of the guide sleeve 32 against the flange comes from the relatively weak spring 5. Specifically, in this embodiment, the maximum axial force of the spring 5 is 20N. Therefore, in this case, since the flange does not contact the rivet nose 2, the shaft 31 and guide sleeve 32 can be directly rotated by an external servo motor to directly rotate the nut and adjust its angle. After adjustment, the servo motor can easily press the guide sleeve 32 and rivet nose 2 together towards the first direction and abut against the flange of the nut. In other words, the servo motor used to rotate the nut and adjust its angle is the same servo motor used to fix the shaft 31 to the nut and ultimately for riveting. This embodiment achieves nut angle adjustment based on the same power source, thus significantly reducing costs. Meanwhile, in existing technologies, nut angle adjustment often requires rotating the entire riveting nut mounting mechanism, necessitating additional motors. Furthermore, the aforementioned method of rotating the entire mechanism has significant errors and higher costs.

[0038] Furthermore, such as Figure 1As shown, in this embodiment, the spring 5 is a spring sleeve extending axially, and the surfaces of the first step 41 and the second step 33 that abut against the spring 5 are perpendicular to the extension direction of the spring 5. This makes the stretching and compression process of the spring 5 more linear, which helps to improve the stability of the guide sleeve 32 in the rotating mechanism 3. Simultaneously, when the spring 5 is in a relaxed state, at least a portion of the guide sleeve 32 extends outward from the rivet nose 2 in the first direction. Specifically, the guide sleeve 32 extends outward from the rivet nose 2, creating a sufficient gap between the flange of the nut and the rivet nose 2, so that the rivet nose 2 does not obstruct the rotation of the nut. Meanwhile, when the spring 5 is in a compressed state, the guide sleeve 32 facing the nut can be flush with the rivet nose 2 facing the nut. That is to say, after the nut is inserted into the hole and the flange facing the first direction is fully in contact with the plate, the rivet nose 2 can apply force to the flange and completely press the flange against the plate through the wall surface of the rivet nose 2 near the flange. At this time, the guide sleeve 32 retracts into the cavity 11 inside the rivet nose 2 under the abutment force of the flange. In this way, the guide sleeve 32 can not hinder the rivet nose 2 from pressing against the top side of the flange of the nut in the subsequent riveting process. At the same time, the guide sleeve 32 also has a certain abutment force on the side facing the flange during riveting, so as to make the riveting process more stable. The external side of the rivet nose 2 facing the second direction includes external threads. The rivet nose 2 is inserted and fixed in the inner cavity 11 on the side facing the second direction. As the contact point with the flange during the riveting process, the rivet nose 2 is a consumable part that is more easily worn. The setting of the threaded connection inside the outer shell 1 makes it easier to replace the rivet nose 2 during maintenance.

[0039] Furthermore, the shaft 31 includes a mandrel 311, a first coupling 312, and a drive shaft 313. The mandrel 311 is disposed on the side of the shaft 31 facing a first direction, and the drive shaft 313 is disposed on the side of the shaft 31 facing a second direction. The first coupling 312 is disposed between the mandrel 311 and the drive shaft 313, and both ends of the first coupling 312 are respectively connected to the mandrel 311 and the drive shaft 313 for transmission. In this embodiment, since the mandrel 311 is directly processed externally, it is a consumable component that has been damaged. The drive shaft 313, on the other hand, is only a force-transmitting structure, not directly exposed to the outside, and is not easily worn. By using the first coupling 312 to transmit force between the mandrel 311 and the drive shaft 313, it is possible for workers to quickly and easily replace the mandrel 311 from the outside after a certain period of use, thus improving the maintenance efficiency of the present invention.

[0040] Furthermore, the traction mechanism 4 includes a spindle fastening nut 42, which is disposed on the side of the traction mechanism 4 facing the first direction. The side of the spindle fastening nut 42 facing the guide sleeve 32 includes a first latch 421, and the guide sleeve 32 includes a second latch 321 that matches the first latch 421. The first latch 421 and the second latch 321 are disposed opposite to each other. For details, please refer to... Figure 1 The traction mechanism 4 can reciprocate between the first and second axial directions under the drive of the external hydraulic cylinder system. Through the abutment combination of the first latch 421 and the second latch 321, the second latch 321 can pull the first latch 421 towards the second direction (or the first direction, or completely fix it to achieve traction in both the first and second directions; in other embodiments, it can be freely set according to the traction direction requirements). This allows the mandrel fastening nut 42 to achieve axial traction of the entire shaft 31 by pulling the guide sleeve 32, facilitating the extension and retraction of the mandrel 311 towards the nut direction for further riveting work. At the same time, the first latch 421 faces towards the second direction, and the second latch 321 faces towards the first direction, so that the contact surface between the first latch 421 and the second latch 321 is larger, making the traction process of the mandrel fastening nut 42 on the guide sleeve 32 more stable.

[0041] In this embodiment, the first step 41 faces the first direction and the second step 33 faces the second direction. At the same time, the abutment of the first step 41 and the second step 33 is located on the side of the transmission shaft 313 in the second direction of the shaft 31. That is to say, the outer periphery of the shaft 31 and the first coupling 312 is provided with an annular second step 33, which makes the structure more space-saving and the structural strength higher.

[0042] Furthermore, such as Figure 3The diagram shown is a schematic of the rotary motor transmission in this embodiment. In this embodiment, a rotary motor 8 is provided at the second end of the principle nut to drive the transmission shaft 313 to rotate. The rotary motor 8 drives the transmission shaft 313 to rotate by driving the second coupling 314. The rotary motor 8 is directly and detachably connected to the second coupling 314 so that the rotary motor 8 or the transmission shaft 313 can be easily disassembled and maintained during later maintenance by disassembling the second coupling 314. Meanwhile, an auxiliary rangefinder 315 for reflecting external detection laser light is also fixedly installed between the second coupling 314 and the drive shaft 313. The auxiliary rangefinder 315 has a plate-like structure extending radially along the drive shaft 313, so that the auxiliary rangefinder 315 can reflect light emitted from an external laser rangefinder device located at a distance (which may be the second end away from the nut). This allows the external laser rangefinder device to detect the axial movement amplitude of the drive shaft 313 in real time by means of the light reflection from the auxiliary rangefinder 315 when the external cylinder drives the drive shaft 313 to reciprocate axially. This is because riveting is a riveting operation with very high precision requirements. Therefore, the detection and control of the riveting amplitude is crucial to the riveting effect. By integrating the auxiliary rangefinder 315 between the second coupling 314 and the drive shaft 313, the reflection of the detection light is conveniently achieved, which facilitates a further improvement in the integration of the rivet nut mounting mechanism in this embodiment.

[0043] In this embodiment, as Figure 4 As shown, the nut used for riveting is a standard-sized hexagonal nut 100, and the plate to be mounted includes a hexagonal hole structure that matches the circumferential dimension of the hexagonal nut 100. That is, in this embodiment, the rotary motor 8 can drive the hexagonal nut 100 to rotate with a precision sufficient to allow the hexagonal nut 100 to move within a range of at least 60 degrees, so that the circumferential dimension of the hexagonal nut 100 can be aligned with the hexagonal hole. Of course, in other embodiments, the nut to be mounted can be other irregularly shaped nuts, as long as the rotation compensation angle of the rotary motor 8 is accurate enough to allow the nut to spin and align with the angle of the hole on the plate.

[0044] Although different specific embodiments are mentioned in this application, this application is not limited to the situations described in industry standards or embodiments. Slightly modified implementations based on certain industry standards or custom methods or embodiments can also achieve the same, equivalent, or similar, or predictable, implementation effects as the above embodiments. Embodiments applying these modified or modified data acquisition, processing, output, and judgment methods still fall within the scope of optional implementations of this application.

[0045] Although this application has been described by way of examples, those skilled in the art will know that this application has many modifications and variations without departing from the spirit of this application, and it is intended that the appended embodiments include these modifications and variations without departing from this application.

Claims

1. A rivet nut mounting mechanism for mounting a nut to a plate that mates with the nut, wherein, The nut includes a flange portion and a shank portion, the shank portion including internal threads; characterized in that the rivet nut mounting mechanism includes: A housing, the housing including an axially extending inner cavity, the housing having a first end facing the nut, the housing having a second end away from the nut, wherein the first direction is a direction extending from the second end of the housing toward the first end, and the second direction is a direction extending from the first end of the housing toward the second end; A rivet nose is fixedly disposed at the first end of the outer casing, and the side of the rivet nose facing the nut is fitted with the flange portion; A rotating mechanism, comprising a shaft and a guide sleeve; the shaft passes axially through the inner cavity and the rivet nose, and at least a portion of the shaft extends outward toward the outside of the rivet nose in the first direction; the guide sleeve is sleeved and fixed to the outside of the shaft along the axial direction; before the rivet nose is engaged with the flange, the side of the guide sleeve facing the nut can engage with the flange. A traction mechanism is sleeved on the outside of the rotating mechanism and disposed in the inner cavity. At least a portion of the outer wall of the traction mechanism matches the inner wall of the inner cavity, so that the traction mechanism can reciprocate along the axial direction in the inner cavity under the drive of an external hydraulic cylinder. In the inner cavity, the traction mechanism includes a first step, and the rotation mechanism includes a second step. The first step and the second step are arranged opposite to each other, and a spring is arranged between the first step and the second step. The two ends of the spring abut against the first step and the second step, respectively. When the spring is in the relaxed state, at least a portion of the guide sleeve extends out of the rivet nose toward the first direction side; When the spring is in a compressed state, the side of the guide sleeve facing the nut can be flush with the side of the rivet nose facing the nut; The traction mechanism includes a spindle fastening nut, which is disposed on the side of the traction mechanism facing the first direction. The side of the spindle fastening nut facing the guide sleeve includes a first buckle, and the guide sleeve includes a second buckle that matches the first buckle. The first buckle and the second buckle are disposed opposite to each other.

2. The rivet nut mounting mechanism according to claim 1, characterized in that: The shaft includes a mandrel, a first coupling, and a drive shaft. The mandrel is disposed on the side of the shaft facing the first direction, and the drive shaft is disposed on the side of the shaft facing the second direction. The first coupling is disposed between the mandrel and the drive shaft, and both ends of the first coupling are respectively connected to the mandrel and the drive shaft for transmission.

3. The rivet nut mounting mechanism according to claim 1, characterized in that: The first buckle faces the side in the second direction, and the second buckle faces the side in the first direction.

4. The rivet nut mounting mechanism according to claim 1, characterized in that: The first step faces the first direction, and the second step faces the second direction.

5. The rivet nut mounting mechanism according to claim 1, characterized in that: The outer side of the rivet nose facing the second direction includes external threads, and the rivet nose facing the second direction passes through and is fixed in the inner cavity.

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