A tightening mechanism for a gas meter nut tightening device

Abstract

The present application relates to a kind of tightening mechanism for gas meter nut tightening equipment, belong to gas meter assembly accessory technical field, including connecting plate, main positioning plate, servo tightening host, sliding seat and U type tightening head;Servo host output shaft passes through the sliding seat of built-in linear bearing and connects tightening head, connecting plate integrates laser displacement sensor and lifting type code scanning gun;Servo host outside is provided with the guiding mechanism of buffer spring, the inside of tightening head is provided with the anti-skid tightening protruding block that can be embedded in nut groove;The present application uses sliding seat guide to promote the coaxial degree of output shaft, buffer spring realizes down pressure floating protection, U type opening structure promotes workpiece alignment fault tolerance, concave-convex meshing structure prevents tightening slip, integrated code scanning and height detection function, assembly precision is high, maintenance is convenient, it is suitable for ultrasonic wave gas meter valve and UMU terminal post nut automatic locking operation.

Description

Technical Field

[0001] This invention belongs to the technical field of automated assembly tooling and accessories for gas meters, specifically relating to a tightening mechanism for a gas meter nut tightening device. Background Technology

[0002] When assembling the ultrasonic gas meter housing, it is necessary to tighten the studs and nuts at the valve and UMU terminal positions. The existing tightening mechanism has many defects: 1. The tightening sleeve has a closed structure, which requires extremely high coaxiality of the nut. After the workpiece is pre-fitted with the nut, it is difficult to align and the threads are easily damaged by impact. 2. The output shaft lacks a sliding guide structure, which can easily lead to eccentricity during long-term lifting and rotating operation, resulting in unstable torque transmission and issues such as nut slippage and stripping. 3. The tightening head has no cushioning structure, and the rigid impact of the tightening head on the thin-walled housing of the gas meter can easily cause housing deformation and coating scratches. 4. The tightening head and nut rely solely on the contact of their outer walls to transmit torque, resulting in low force and easy slippage, and the torque does not meet the process standards; 5. The scanning component and tightening mechanism are not integrated into a single design. The scanning device is placed separately, occupying equipment space and posing a high risk of motion interference. 6. Without a matching height detection component, the assembly height of the nut and stud cannot be detected simultaneously after tightening, and can only be checked manually by sampling, resulting in many missed defects.

[0003] Therefore, improvements are needed to address the aforementioned technical issues. Summary of the Invention

[0004] To address the shortcomings of existing gas meter tightening mechanisms, such as poor alignment tolerance, lack of guiding buffer, easy slippage during tightening, limited functionality, and inconvenient disassembly and maintenance, this invention provides a tightening mechanism for gas meter nut tightening equipment. The mechanism utilizes a linear bearing built into the sliding seat to guide and limit the output shaft, coupled with a buffer spring to achieve downward floating compensation. A U-shaped open tightening head with a torque protrusion enhances alignment tolerance and torque transmission capability. An integrated barcode scanner and laser displacement sensor simultaneously complete barcode scanning, tightening, and height detection, improving assembly accuracy and equipment integration.

[0005] To achieve the above objectives, the technical solution adopted by this invention is as follows: a tightening mechanism for a gas meter nut tightening device, comprising a connecting plate, a main unit positioning plate, a servo tightening main unit, a sliding seat, and a tightening head; the main unit positioning plate is fixedly mounted on the connecting plate, the servo tightening main unit is fixedly mounted on the main unit positioning plate, and a servo main unit output shaft is provided at the bottom of the servo tightening main unit, which passes through the sliding seat and is rigidly connected to the tightening head; a laser displacement sensor is mounted on the side of the connecting plate, which is used to synchronously detect the height of the stud and nut relative to the reference height of the gas meter housing; with the above solution, the sliding seat passes through the servo main unit output shaft, forming a stable radial guide for the output shaft, and the coaxiality is high during the lifting and rotating process, avoiding the tightening head from deviating and hitting the threads; the connecting plate integrates a laser displacement sensor, and after tightening, the height of the stud and nut can be synchronously detected without additional moving modules, simplifying the overall movement structure; the overall modular structure allows for overall disassembly and assembly into the equipment movement module, facilitating independent replacement and maintenance.

[0006] As a preferred embodiment of the present invention, the tightening head is a U-shaped structure with the opening facing downwards. The tightening head includes a tightening body, and two sets of tightening blocks are symmetrically arranged at the bottom of the tightening body. A tightening port for the nut to be inserted is formed between the two sets of tightening blocks. The U-shaped opening structure does not require high-precision coaxial alignment. The nut can be directly engaged when the workpiece is pre-fitted with a nut, and the loading and unloading error tolerance is high. The tightening blocks on both sides surround the outer wall of the nut, so the force is uniform and the torque transmission is stable.

[0007] As a preferred embodiment of the present invention, the inner side of the tightening block is provided with a tightening groove surface that fits the outer wall of the nut, and a tightening protrusion is integrally formed on the inner side of the tightening groove surface; a groove matching the tightening protrusion is opened on the top of the nut, and the tightening protrusion is embedded in the groove to transmit circumferential torque; the tightening protrusion is embedded in the groove on the top of the nut, and the circumferential torque is transmitted by the concave-convex cooperation, which avoids the tightening block from slipping and spinning freely with the outer wall of the nut, ensures that the servo set torque is fully applied to the nut, and eliminates floating lock failure.

[0008] As a preferred embodiment of the present invention, the servo tightening host is equipped with a guide mechanism on its outer side. The guide mechanism includes a guide cylinder and a buffer spring. The drive shaft of the guide cylinder is connected to one end of the buffer spring, and the other end of the buffer spring abuts against the mounting seat. The mounting seat is fixed to the connecting plate and located below the positioning plate of the host. The guide cylinder and the buffer spring form a floating buffer structure. When the tightening head is pressed down, the spring is compressed to absorb the positioning tolerance of the workpiece, avoiding rigid impact that could damage the gas meter housing and threads, and buffering to protect the workpiece.

[0009] In a preferred embodiment of the present invention, a support plate is vertically fixed in the middle of the connecting plate, and a lifting drive cylinder is fixed on the support plate. The output shaft of the lifting drive cylinder is connected to the barcode scanning mounting plate, and a barcode scanner is fixedly mounted on the barcode scanning mounting plate. The lifting cylinder independently drives the barcode scanner to rise and fall. When scanning, the scanner descends to identify the QR code, and when tightening, it rises to avoid the movement path of the tightening head, without structural interference. The barcode scanning mechanism and the tightening mechanism are integrated into one unit, reducing the number of equipment parts and saving frame layout space.

[0010] As a preferred embodiment of the present invention, a linear bearing is embedded inside the sliding seat, and the output shaft of the servo host passes through the linear bearing. The linear bearing provides radial limiting and guidance for the output shaft of the servo host. The linear bearing built into the sliding seat reduces the frictional resistance of the servo output shaft during lifting and rotation, making it less prone to wear during long-term operation. At the same time, it limits the radial offset of the output shaft and improves the tightening repeatability and positioning accuracy.

[0011] As a preferred embodiment of the present invention, the buffer spring is a compression spring, which is sleeved on the outside of the servo tightening host. When the tightening head presses down to lock the nut, the buffer spring is compressed to achieve floating compensation. The buffer spring is sleeved on the outside of the servo host, so the force is uniform and the downward buffer stroke is stable. It is suitable for gas meter housings of different heights and specifications, and has stronger versatility.

[0012] As a preferred embodiment of the present invention, a reinforcing rib is provided between the main unit positioning plate and the connecting plate, and the two ends of the reinforcing rib are welded and fixed to the main unit positioning plate and the connecting plate respectively, thereby improving the installation rigidity of the servo tightening main unit; the addition of the reinforcing rib to the main unit positioning plate improves the installation structure rigidity of the servo tightening main unit, ensuring that the main unit does not shake during high torque tightening operations and ensuring stable torque output.

[0013] As a preferred embodiment of the present invention, the surface of the tightening protrusion is covered with a wear-resistant and anti-slip rubber layer. The rubber layer increases the friction with the inner wall of the nut groove and prevents slippage and free rotation during tightening. The outer layer of the tightening protrusion is covered with a rubber anti-slip layer, which increases the friction with the inner wall of the nut groove and further prevents slippage. At the same time, it buffers the hard metal contact and reduces scratches on the nut surface.

[0014] As a preferred embodiment of the present invention, the barcode scanning mounting plate and the output shaft of the lifting drive cylinder are detachably threaded, allowing the barcode scanner to be disassembled and replaced separately, making disassembly and maintenance convenient; since the barcode scanning mounting plate and the cylinder output shaft are detachably threaded, the barcode scanner can be replaced or repaired separately without disassembling the entire tightening mechanism, reducing equipment maintenance time.

[0015] The beneficial effects of this invention are: This invention employs a sliding seat guide to improve the coaxiality of the output shaft, a buffer spring to achieve downward floating protection, a U-shaped opening structure to improve the workpiece alignment tolerance, a concave-convex meshing structure to prevent slippage during tightening, and an integrated barcode scanning and height detection function. It features high assembly accuracy, convenient maintenance, and is suitable for automated locking operations of ultrasonic gas meter valves and UMU terminal nuts. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the tightening mechanism of the present invention; Figure 2 This is a schematic diagram (a) of the assembly of the tightening mechanism and the nut of the present invention; Figure 3 This is a schematic diagram (II) of the assembly of the tightening mechanism and the nut of the present invention; Figure 4 This is a schematic diagram (III) of the assembly of the tightening mechanism and the nut of the present invention; Explanation of reference numerals in the attached drawings: Nut 3, Tightening mechanism 4, Laser displacement sensor 10, Connecting plate 40, Main unit positioning plate 41, Servo tightening main unit 42, Sliding seat 43, Servo main unit output shaft 44, Tightening head 45, Tightening body 45-1, Tightening block 45-2, Tightening port 45-3, Tightening groove surface 45-4, Tightening block 45-5, Guide mechanism 46, Guide cylinder 47, Buffer spring 48, Mounting seat 49, Gas meter housing 100, Groove 301, Support plate 401, Lifting drive cylinder 402, Barcode scanning mounting plate 403, Barcode scanner 404. Detailed Implementation

[0017] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] This embodiment discloses a gas meter nut tightening mechanism, which is a modular independent assembly unit. The whole assembly is mounted on a three-axis motion module slide, and can complete the lateral, longitudinal, and lifting displacement with the motion module. It works with the clamping and flipping fixture below to complete the scanning, nut servo locking, and assembly height detection processes.

[0020] Specifically, refer to Figures 1-4 As shown, the connecting plate 40 serves as the overall load-bearing base of this mechanism. It is integrally formed from thickened bent steel plate, and the plate surface is divided into a main unit installation area, a barcode scanning mechanism installation area, and a sensor installation area. The back of the connecting plate 40 has pre-drilled module connection screw holes, allowing it to be locked onto the three-axis motion slide of the equipment. A main unit positioning plate 41 is welded to the upper front of the connecting plate 40. Multiple triangular reinforcing ribs are welded between the main unit positioning plate 41 and the connecting plate 40. The two ends of the reinforcing ribs are respectively attached to the surfaces of the main unit positioning plate 41 and the connecting plate 40 and fully welded for fixation, significantly improving the load-bearing rigidity of the main unit positioning plate 41 and offsetting the vibration deformation caused by the large torque of the servo tightening. A support plate 401 is vertically welded to the middle of the connecting plate 40. A laser displacement sensor 10 is locked to the right side wall of the connecting plate 40 via a bracket. The detection probe of the laser displacement sensor 10 points vertically downwards, facing the gas meter housing 100 assembly station below, and is used to synchronously collect data on the height of the studs and nuts relative to the housing reference.

[0021] The servo tightening host 42 is vertically suspended and fixed in the center mounting hole of the host positioning plate 41. The power output end of the servo tightening host 42 faces downward, and the servo host output shaft 44 extends vertically from the bottom of the host. The mounting base 49 is bolted to the lower surface of the host positioning plate 41. The mounting base 49 has a center hole, and a sliding seat 43 is vertically fixed in the hole. A linear bearing is interference-fitted into the sliding seat 43. The servo host output shaft 44 passes through the linear inner hole from top to bottom. The linear bearing provides omnidirectional radial limit for the servo host output shaft 44, restricting radial displacement during the lifting and rotation of the output shaft and reducing sliding friction resistance.

[0022] The bottom of the servo host output shaft 44 is threaded with an external thread, and the threaded section is tightened to fix the tightening head 45, so as to realize the rigid synchronous transmission between the output shaft and the tightening head 45.

[0023] A guide mechanism 46 is arranged around the outside of the servo tightening host 42. The guide mechanism 46 includes a guide cylinder 47 and a buffer spring 48. The guide cylinder 47 is vertically bolted to the mounting base 49. The guide cylinder 47 is driven by a downward-facing extension shaft. The lower end of the drive shaft is connected to the upper end of the buffer spring 48. The buffer spring 48 is a cylindrical compression spring and is fitted as a whole around the servo tightening host 42 and the outside of the sliding seat 43. The lower end of the buffer spring 48 abuts against the lower flange surface of the sliding seat 43. When the tightening mechanism is pressed down as a whole, the buffer spring 48 is compressed and shrinks. The vertical floating compensation is achieved by the spring deformation, which absorbs the small dimensional errors in the workpiece positioning and avoids the tightening head 45 rigidly impacting the nut 3 and the gas meter housing 100, causing scratches and thread damage.

[0024] The tightening head 45 is an integral U-shaped machined part with an opening facing downwards, including a tightening body 45-1; the top of the tightening body 45-1 has a threaded hole, which is locked with the bottom thread of the servo host output shaft 44; two sets of tightening blocks 45-2 extend symmetrically from the bottom of the tightening body 45-1, and the two sets of tightening blocks 45-2 form a hollow tightening port 45-3, and the nut 3 can be vertically inserted into the tightening port 45-3 from below.

[0025] Each tightening block 45-2 has an arc-shaped tightening groove surface 45-4 machined on its inner side, and the arc-shaped contour completely fits the outer hexagonal outer wall of the nut 3; a tightening protrusion 45-5 is integrally raised in the middle of the tightening groove surface 45-4, and the outer surface of the tightening protrusion 45-5 is completely covered with a layer of wear-resistant and anti-slip rubber; a groove 301 matching the tightening protrusion 45-5 is opened on the upper end face of the gas meter matching nut 3, and after the tightening head 45 is pressed down, the tightening protrusion 45-5 is embedded into the top groove 301 of the nut 3. The concave and convex meshing structure transmits circumferential torque, and the rubber layer increases the friction of the contact surface, preventing the tightening head 45 from slipping and spinning freely with the outer wall of the nut 3 during the tightening process, and ensuring that the standard torque of 18~20 kgf.cm is completely applied to the thread section.

[0026] A support plate 401 is vertically fixed in the middle of the connecting plate 40. The lifting drive cylinder 402 is vertically locked in the front of the support plate 401. The piston rod of the lifting drive cylinder 402 is arranged downward. The bottom end of the output shaft of the lifting drive cylinder 402 is threaded and detachably threaded to the center threaded hole of the barcode mounting plate 403. The barcode mounting plate 403 and the barcode scanner 404 can be unscrewed and replaced separately without disassembling the entire mechanism. The barcode mounting plate 403 is horizontally fixed to the barcode scanner 404 by locking screws. The lens of the barcode scanner 404 is vertically downward.

[0027] The lifting drive cylinder 402 can drive the barcode scanning mounting plate 403 and the barcode scanner 404 to move vertically in sync: during the barcode scanning process, the cylinder piston rod extends and the barcode scanner 404 descends to approach the surface of the gas meter housing 100 to read the QR code; during the tightening operation, the cylinder retracts and the barcode scanner 404 rises to avoid the downward movement path of the tightening head 45, thus eliminating motion interference.

[0028] In this embodiment, the tightening mechanism works as follows: Standby relocation stage: The three-axis motion module drives the entire tightening mechanism to move to the preset scanning point above the tooling. The piston rod of the lifting drive cylinder 402 extends, and the barcode scanner 404 descends to scan the QR code on the surface of the gas meter housing 100, completing the binding and storage of single product information. After scanning, the lifting drive cylinder 402 retracts, and the barcode scanner 404 rises to avoid the obstacle.

[0029] During the downward alignment stage: the motion module drives the entire mechanism to feed downwards, and the U-shaped tightening head 45 fits the nut 3 pre-positioned on the outside of the stud 6 from bottom to top. The nut 3 enters the tightening port 45-3, and the tightening protrusion 45-5 is embedded in the groove 301 on the top of the nut 3. During the downward pressing process, the buffer spring 48 is compressed, and the spring floating amount is used to compensate for the tooling positioning deviation and avoid hard contact and squeezing of the workpiece.

[0030] Servo tightening stage: The servo tightening host 42 receives the torque signal from the PLC and starts. The output shaft 44 of the servo host rotates synchronously and outputs the set locking torque to the nut 3 through the tightening body 45-1, tightening block 45-2, and tightening protrusion 45-5. The linear bearing inside the sliding seat 43 constrains the output shaft 44 of the servo host to keep it rotating vertically and coaxially without radial wobble. The system collects the torque value in real time. After the process standard is reached, the servo tightening host 42 immediately brakes and stops rotating.

[0031] Lifting and testing phase: The three-axis module drives the entire tightening mechanism to lift slightly, so that the tightening head 45 is disengaged from the nut 3; the module makes a slight lateral adjustment to position so that the laser displacement sensor 10 on the side of the connecting plate 40 is aligned with the assembly point, and simultaneously collects two sets of data: the end face of the stud and the upper end of the nut relative to the reference height of the gas meter housing 100, completes the OK / NG dimension judgment and uploads it to the backend server.

[0032] Reset cycle stage: After all processes are completed, the three-axis motion module drives the entire tightening mechanism to reset to the initial safe avoidance position, waiting for the next gas meter housing 100 processing cycle.

[0033] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention; therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0034] Although this document frequently uses reference numerals from the figures, such as nut 3, tightening mechanism 4, laser displacement sensor 10, connecting plate 40, main unit positioning plate 41, servo tightening main unit 42, sliding seat 43, servo main unit output shaft 44, tightening head 45, tightening body 45-1, tightening block 45-2, tightening port 45-3, tightening groove surface 45-4, tightening block 45-5, guide mechanism 46, guide cylinder 47, buffer spring 48, mounting base 49, gas meter housing 100, groove 301, support plate 401, lifting drive cylinder 402, barcode scanning mounting plate 403, and barcode scanner 404, the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. A tightening mechanism for a gas meter nut tightening device, characterized in that, The system includes a connecting plate (40), a main unit positioning plate (41), a servo tightening main unit (42), a sliding seat (43), and a tightening head (45). The main unit positioning plate (41) is fixed on the connecting plate (40), and the servo tightening main unit (42) is fixedly installed on the main unit positioning plate (41). The bottom of the servo tightening main unit (42) is provided with a servo main unit output shaft (44), which passes through the sliding seat (43) and is rigidly connected to the tightening head (45). A laser displacement sensor (10) is mounted on the side of the connecting plate (40). The laser displacement sensor (10) is used to synchronously detect the height of the stud and nut relative to the gas meter housing reference height.

2. The tightening mechanism for a gas meter nut tightening device according to claim 1, characterized in that, The tightening head (45) is a U-shaped structure with the opening facing downwards. The tightening head (45) includes a tightening body (45-1). Two sets of tightening blocks (45-2) are symmetrically arranged at the bottom of the tightening body (45-1). A tightening port (45-3) for the nut (3) to be inserted is formed between the two sets of tightening blocks (45-2).

3. The tightening mechanism for a gas meter nut tightening device according to claim 2, characterized in that, The inner side of the tightening block (45-2) is provided with a tightening groove surface (45-4) that fits the outer wall of the nut (3), and the inner side of the tightening groove surface (45-4) is integrally formed with a tightening protrusion (45-5); the top of the nut (3) is provided with a groove (301) that matches the tightening protrusion (45-5), and the tightening protrusion (45-5) is embedded in the groove (301) to transmit circumferential torque.

4. The tightening mechanism for a gas meter nut tightening device according to claim 1, characterized in that, The servo tightening host (42) is equipped with a guide mechanism (46) on the outside. The guide mechanism (46) includes a guide cylinder (47) and a buffer spring (48). The drive shaft of the guide cylinder (47) is connected to one end of the buffer spring (48), and the other end of the buffer spring (48) abuts against the mounting seat (49). The mounting seat (49) is fixed to the connecting plate (40) and located below the host positioning plate (41).

5. The tightening mechanism for a gas meter nut tightening device according to claim 1, characterized in that, A support plate (401) is vertically fixed in the middle of the connecting plate (40), and a lifting drive cylinder (402) is fixed on the support plate (401). The output shaft of the lifting drive cylinder (402) is connected to the barcode scanning mounting plate (403), and a barcode scanner (404) is fixedly mounted on the barcode scanning mounting plate (403).

6. The tightening mechanism for a gas meter nut tightening device according to claim 1, characterized in that, The sliding seat (43) is fitted with a linear bearing, and the servo host output shaft (44) passes through the linear bearing.

7. The tightening mechanism for a gas meter nut tightening device according to claim 4, characterized in that, The buffer spring (48) is a compression spring, and the buffer spring (48) is fitted on the outside of the servo tightening host (42).

8. The tightening mechanism for a gas meter nut tightening device according to claim 1, characterized in that, A reinforcing rib is provided between the main unit positioning plate (41) and the connecting plate (40), and the two ends of the reinforcing rib are welded and fixed to the main unit positioning plate (41) and the connecting plate (40) respectively.

9. The tightening mechanism for a gas meter nut tightening device according to claim 3, characterized in that, The surface of the tightening protrusion (45-5) is covered with a wear-resistant and anti-slip rubber layer.

10. The tightening mechanism for a gas meter nut tightening device according to claim 5, characterized in that, The barcode scanning mounting plate (403) and the output shaft of the lifting drive cylinder (402) are connected by a detachable thread.

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