Detection mechanism for thickness of o-ring of rivet nut

Abstract

This utility model relates to a mechanism for detecting the thickness of O-rings in rivet nuts, including a frame and a nut positioning fixture. A mounting base is installed on the surface of the frame, and a pneumatic cylinder is fixedly mounted on the top of the mounting base. The piston rod of the pneumatic cylinder passes through the bottom of the cylinder and into the mounting base, and is connected to a detection fixing plate via fasteners. A displacement sensor is installed on the upper end of the detection fixing plate. The lower end of the detection fixing plate elastically engages with a clamping assembly via an elastic element, enabling the clamping assembly to apply a pressing force to the O-ring and generate displacement as the force changes. This utility model applies a predetermined load to the O-ring by driving the detection plate and spring pressure tube with a cylinder, and uses the displacement sensor to collect the compression displacement value in real time. This not only accurately identifies whether the O-ring is assembled, but also precisely measures the compressed thickness of the O-ring, thereby achieving online quality control, significantly improving detection efficiency and reliability, and reducing production costs.

Description

Technical Field

[0001] This utility model relates to the field of sealing ring testing, specifically a mechanism for testing the thickness of O-rings in rivet nuts. Background Technology

[0002] In existing technologies, the combination of rivet nuts and O-rings is widely used in sealing and fastening applications in industries such as automotive and electronics. Typically, on the production line, O-rings are first fitted onto rivet nuts using mechanical equipment, and then a rivet gun is used to rivet the nuts, allowing the sheet metal and nut to fit tightly together with the O-ring to achieve a seal. While the quality and technology of domestic rivet nut and O-ring combination products are continuously improving, their production volume is also steadily increasing, and customers are placing increasingly stringent quality control requirements on the products.

[0003] However, existing assembly processes are prone to missing or poorly assembled O-rings during high-speed mass production, and it is difficult to monitor the actual compression thickness of the seals online, leading to increased risk of finished product leakage and high rework and scrap rates. Moreover, traditional manual or offline inspection methods are inefficient and slow to respond, failing to meet the closed-loop quality control requirements of modern production lines.

[0004] To address the aforementioned issues, this solution provides an automated inspection mechanism that integrates O-ring presence / absence detection and thickness measurement. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the existing technology, adapt to practical needs, and provide a mechanism for detecting the thickness of O-rings in rivet nuts. This addresses the current assembly process, which is prone to missing or poorly assembled O-rings during high-speed mass production. Furthermore, it is difficult to monitor the actual compression thickness of the sealing ring online, leading to increased risk of finished product leakage and high rework and scrap rates. In addition, traditional manual or offline detection methods are inefficient and slow to respond, failing to meet the closed-loop quality control requirements of modern production lines.

[0006] To achieve the purpose of this utility model, the technical solution adopted by this utility model is as follows: design a rivet nut O-ring thickness detection mechanism, including a frame and a nut positioning fixture. A mounting seat is installed on the surface of the frame. A pneumatic cylinder is fixedly installed on the top of the mounting seat. The piston rod of the pneumatic cylinder passes through the bottom of the cylinder and is installed in the mounting seat, and is connected to the detection fixing plate by fasteners.

[0007] A displacement sensor is installed on the upper end of the detection fixing plate;

[0008] The lower end of the detection fixing plate is elastically engaged with the clamping assembly through an elastic element, so that the clamping assembly can apply a pressing force to the O-ring and generate displacement as the force changes.

[0009] Preferably, the elastic element is a spring.

[0010] Preferably, the clamping assembly is a clamping tube.

[0011] Preferably, the nut positioning fixture includes a positioning seat, and a positioning pin is installed inside the positioning seat to constrain the position of the rivet nut.

[0012] Preferably, a rivet nut is fitted onto the top of the positioning pin, and an O-ring is fitted between the rivet nut and the positioning seat.

[0013] Preferably, the detection fixing plate is guided to the frame by a linear guide rail, and the slider of the linear guide rail is installed and fixed to the detection fixing plate to realize the linear reciprocating motion of the detection fixing plate along the cylinder piston rod axis.

[0014] Preferably, a center rod is installed at the top of the pressure tube, and a spring is sleeved on the outside of the center rod. When the cylinder piston rod drives the detection plate to move downward, the pressure tube applies pressure to the O-ring, and at the same time, the center rod drives the spring to compress and move upward. The displacement sensor collects the displacement and records the actual value.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] 1. This utility model applies a predetermined load to the O-ring by driving the detection plate and spring compression tube with a cylinder, and uses a displacement sensor to collect the compression displacement value in real time. It can not only accurately identify whether the O-ring is assembled, but also accurately measure the compression thickness of the O-ring, thereby realizing online quality control, greatly improving detection efficiency and reliability, and reducing production costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0018] Figure 2 This is a cross-sectional view of the present invention.

[0019] Figure 3 This is a schematic diagram of the mounting base structure of this utility model.

[0020] In the diagram: 1. Pneumatic cylinder; 2. Linear guide rail; 3. Displacement sensor; 4. Detection fixing plate; 5. Spring; 6. Pressure tube; 7. Nut positioning fixture; 8. Rivet nut; 9. O-ring; 10. Positioning seat; 11. Positioning pin; 12. Frame; 13. Mounting base. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0022] Example 1: Mechanism for detecting the thickness of O-rings in rivet nuts, see [link / reference] Figures 1 to 3The assembly includes a frame 12 and a nut positioning fixture 7. A mounting base 13 is mounted on the surface of the frame 12. A pneumatic cylinder 1 is fixedly mounted on the top of the mounting base 13. The piston rod of the pneumatic cylinder 1 passes through the bottom of the cylinder and is mounted on the mounting base 13. It is connected to the detection fixing plate 4 by fasteners. The lower end of the detection fixing plate 4 is elastically engaged with the pressure tube 6 by a spring 5, so that the pressing assembly can apply a pressing force to the O-ring 9 and move with the force.

[0023] Specifically, the rivet nut 8 and O-ring 9 assembly is held by a robotic arm and placed on a nut fixing fixture. Then, the pneumatic cylinder 1 is vented to make the piston rod move down from the mounting base 13 and drive the detection fixing plate 4 to move down through the connecting plate until the pressure tube 6 contacts and initially presses the O-ring 9. Since the spring 5 is extensible, the pressure tube 6 and its coaxial central rod move up with the pressing force.

[0024] It is worth noting that, see Figure 1 and Figure 2 The nut positioning fixture 7 includes a positioning seat 10, and a positioning pin 11 is installed inside the positioning seat 10 to constrain the position of the rivet nut 8. The rivet nut 8 and the O-ring 9 assembly are clamped by a robot and placed on the nut fixing fixture.

[0025] It is worth noting that, see Figure 1 and Figure 2 The top of the positioning pin 11 is fitted with a rivet nut 8, and an O-ring 9 is assembled between the rivet nut 8 and the positioning seat 10.

[0026] It is worth mentioning that, see Figure 1 The detection fixing plate 4 is guided to the frame 12 by the linear guide rail 2. The slider of the linear guide rail 2 is installed and fixed to the detection fixing plate 4 so as to realize the linear reciprocating motion of the detection fixing plate 4 along the cylinder piston rod axis.

[0027] It is worth emphasizing that, see Figure 1 A central rod is installed at the top of the pressure tube 6, and a spring 5 is sleeved on the outside of the central rod. When the cylinder piston rod drives the detection plate to move down, the pressure tube 6 applies pressure to the O-ring 9. At the same time, the central rod drives the spring 5 to compress and move upward. The displacement sensor 3 collects the displacement and records the actual value.

[0028] It is worth noting that, see Figure 1 A displacement sensor 3 is installed on the upper end of the detection fixing plate 4.

[0029] Specifically, displacement sensor 3 records the displacement value A corresponding to compression. After the above measurement is completed, the detection fixing plate 4 is reset and the O-ring 9 is removed. The pneumatic cylinder 1 is restarted. The output value B of displacement sensor 3 is recorded again in the state without O-ring 9. When the set good product displacement range M meets B < M < A, it is judged as qualified. If it does not meet the range, it is judged as defective (including missing O-ring 9 or mixed O-ring 9 of incorrect specifications). Finally, the judgment signal is received by the position sensor and the external sorting mechanism is triggered to discharge OK parts and NG parts respectively, realizing online quality control.

[0030] When using the rivet nut O-ring thickness detection mechanism, the rivet nut 8 and O-ring 9 assembly is held by a robotic arm and placed on the nut fixing fixture. Then, the pneumatic cylinder 1 is vented, causing the piston rod to descend from the mounting base 13 and move downward through the connecting plate to the detection fixing plate 4 until the pressure tube 6 contacts and initially presses the O-ring 9. Due to the extensibility of the spring 5, the pressure tube 6 and its coaxial central rod move upward with the pressing force. At this time, the displacement sensor 3 records the corresponding displacement value A after compression. After completing the above measurement, the detection fixing plate 4 is reset and the O-ring 9 is removed. The pneumatic cylinder 1 is restarted, and the output value B of the displacement sensor 3 is recorded again in the state without the O-ring 9. When the set good product displacement range M satisfies B < M < A, it is judged as qualified. If it does not meet the range, it is judged as defective (including missing O-ring 9 or mixed O-ring 9 of the wrong specification). Finally, the position sensor receives the judgment signal and triggers the external sorting mechanism to discharge OK and NG parts respectively, realizing online quality control.

[0031] In addition, all components designed in this utility model are general standard parts or components known to those skilled in the art. Their structure and principle can be learned by those skilled in the art through technical manuals or conventional experimental methods. Those skilled in the art can fully implement them, so there is no need to elaborate. The content protected by this utility model does not involve improvements to the internal structure and method.

Claims

1. A mechanism for detecting the thickness of an O-ring of a pull-rivet nut, comprising a rack (12) and a nut positioning tool (7), characterized in that, The frame (12) is mounted with a mounting base (13), and a pneumatic cylinder (1) is fixedly installed on the top of the mounting base (13). The piston rod of the pneumatic cylinder (1) passes through the bottom of the cylinder and is installed in the mounting base (13), and is connected to the detection fixing plate (4) by fasteners. A displacement sensor (3) is installed on the upper end of the detection fixing plate (4); The lower end of the detection fixing plate (4) is elastically engaged with the pressing assembly through an elastic element, so that the pressing assembly can apply a pressing force to the O-ring (9) and generate displacement as the force changes.

2. The rivet nut O-ring thickness detection mechanism according to claim 1, wherein The elastic element is a spring (5).

3. The rivet nut O-ring thickness detection mechanism according to claim 1, wherein The clamping assembly is a clamping tube (6).

4. The rivet nut O-ring thickness detection mechanism according to claim 1, wherein The nut positioning fixture (7) includes a positioning seat (10), and a positioning pin (11) is installed inside the positioning seat (10) to constrain the position of the rivet nut (8).

5. The rivet nut O-ring thickness detection mechanism according to claim 4, wherein The top of the positioning pin (11) is fitted with a rivet nut (8), and an O-ring (9) is fitted between the rivet nut (8) and the positioning seat (10).

6. The rivet nut O-ring thickness detection mechanism according to claim 1, wherein The detection fixing plate (4) is guided to the frame (12) by the linear guide rail (2). The slider of the linear guide rail (2) is installed and fixed to the detection fixing plate (4) so ​​as to realize the linear reciprocating motion of the detection fixing plate (4) along the cylinder piston rod axis.

7. The rivet nut O-ring thickness detection mechanism according to claim 3, wherein The pressure tube (6) is equipped with a central rod at the top, and a spring (5) is sleeved on the outside of the central rod. When the cylinder piston rod drives the detection plate to move down, the pressure tube (6) applies pressure to the O-ring (9), and at the same time, the central rod drives the spring (5) to compress and move upward. The displacement sensor (3) collects the displacement and records the actual value.

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