A device for automatically tightening multiple screws simultaneously

Abstract

The present invention discloses a device for automatically tightening multiple screws simultaneously, which is composed of a base plate and a vertical plate welded together; wherein the base plate is provided with a slider guide rail structure, a double-axis cylinder, a workpiece mounting plate, a cylinder, etc., the workpiece mounting plate is connected with the cylinder and the slider, and moves back and forth under the action of a control system; the vertical plate is welded with a pneumatic screwdriver fixing plate, a buffer plate assembly, a screwdriver guide assembly, a slider guide rail structure, etc., the buffer plate assembly and the screwdriver guide assembly are all connected to the slider, and are driven by the driving cylinder to ensure that they move up and down on the guide rail in the correct position, and under the action of the control system, multiple groups of screws are tightened simultaneously according to a certain torque through the control of on and off air; the problem of large discreteness of assembly torque due to different tightening sequences of connecting parts during the screw tightening process is solved, thereby improving assembly efficiency, and at the same time, there is no need to manually hold the pneumatic screwdriver, thereby reducing manual labor intensity.

Description

Technical Field

[0001] The invention relates to the technical field of automatic screw fastening fixtures, and in particular to a device for automatically fastening multiple screws simultaneously. Background Art

[0002] At present, in the process of screw installation, especially when there are multiple screws on a plane that need to be tightened, and the torque control of the screws needs to be more precise, such as the engine crankcase screws, the cylinder head and the cylinder head fastening screws, it is often used to tighten the screws one by one with a handheld pneumatic screwdriver. Since each screw is not tightened at the same time during the tightening process, the tightening torque is quite different, so it is necessary to use a torque wrench to tighten each screw again. At the same time, during the long operation process, the workers will cause damage to their hands for a long time. At the same time, the work efficiency is low and the labor intensity is high during manual operation. However, for some production line assembly processes, it is often necessary to install screws in a fixed position, and a device for automatically tightening multiple screws at the same time can be designed. Summary of the invention

[0003] In order to solve the problems raised in the above background technology, the present invention provides an automatic fastening device which can automatically fasten multiple screws simultaneously and achieve a constant torque.

[0004] The technical solution adopted by the present invention is a device for automatically tightening multiple screws simultaneously, comprising:

[0005] The bottom plate has a slider guide structure, a dual-axis cylinder, a workpiece mounting plate, a cylinder and other components. The workpiece mounting plate is connected to the cylinder and the slider. The workpiece is positioned and mounted on the workpiece mounting plate. The cylinder presses it and moves it back and forth under the control system.

[0006] The vertical plate is welded together, and there is a pneumatic screwdriver fixing plate and a slider guide structure on the vertical plate. The slider guide structure is fixed with a buffer plate assembly and a screwdriver guide assembly. The slider guide structure moves up and down on the guide rail A driven by the driving cylinder. Under the action of the control system, multiple sets of screws are tightened at a certain torque at the same time through the control of the on-off air.

[0007] The control system is composed of a solenoid valve, a PLC controller, a magnetic switch, etc., which controls the movement of the cylinder and the on and off of the fixed torque air screwdriver to achieve automatic control of the fastening device.

[0008] A fixed torque air screwdriver is fixed on the air screwdriver fixing plate, which is connected to the transmission shaft through a connecting column. When the tightening torque reaches the set torque, the air screwdriver stops automatically. In the next working cycle, the fixed torque air screwdriver needs to be reset before it can continue to work.

[0009] The buffer plate assembly consists of a slider fixing plate, a transmission shaft fixing plate, a transmission shaft support seat, a transmission shaft, a bearing A, a spring A, etc., which ensures the torque transmission of the transmission shaft through the transmission shaft connecting sleeve, the screwdriver connecting sleeve and the screwdriver head, and realizes buffering when the screwdriver head contacts the fastening screw. The tappet, spring B, connecting column, pin shaft and transmission shaft connecting sleeve inside the transmission shaft form the automatic reset mechanism of the fixed torque air screwdriver;

[0010] The screwdriver guide assembly is composed of a slider fixing plate A, a screwdriver fixing plate, a screwdriver positioning sleeve, and a bearing B, which ensures the correct positioning and transmission of the screwdriver during operation.

[0011] The positive effects of the present invention are as follows: the present invention drives the cylinder along the guide rail to drive the downward pressure type fixed torque wrench of the air screwdriver fixing plate, the automatic resetting mechanism of the buffer plate combination, and the screwdriver of the screwdriver guide combination to automatically tighten multiple screws at the same time, and combines the fixed torque function of the fixed torque air screwdriver to achieve consistency of tightening torque, improve assembly efficiency, and reduce labor intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic diagram showing an embodiment of the present invention;

[0013] Figure 2 is an assembly diagram showing a buffer plate assembly in an embodiment of the present invention;

[0014] Figure 3 is an assembly diagram showing a screwdriver guide assembly in an embodiment of the present invention;

[0015] Figure 4 The tightening torque values ​​of the conventional manual pneumatic screwdriver and the fixed-torque pneumatic screwdriver of the present invention are compared.

[0016] Description of the serial numbers in the attached drawings:

[0017] 1. Base plate; 2. Cylinder; 3. Workpiece mounting plate; 4. Vertical plate welding; 5. Guide rail A; 6. Screwdriver head; 7. Screwdriver guide assembly; 7a. Screwdriver fixing plate; 7b. Slider fixing plate A; 7c. Screw D; 7d. Bearing cover plate; 7e. Screwdriver positioning sleeve; 7f. Shaft retaining ring; 7g. Bearing B; 7h. Screw E; 8. Screwdriver connecting sleeve; 9. Connecting column A; 10. Screw A; 11. Buffer plate assembly; 11a. Slider fixing plate; 11b. Drive shaft fixing plate; 11c. Drive shaft support seat; 11d. Bushing; 11e. Spring Spring A; 11f. Transmission shaft; 11g. Transmission shaft connecting sleeve; 11h. Retaining ring; 11i. Pin shaft; 11j. Tappet; 11k. Spring B; 11l. Bearing A; 11m. Connecting column 11n. Screw F; 12. Connecting column B; 13. Air screw fixing plate; 14. Constant torque air screw; 15. Cylinder fixing plate; 16. Driving cylinder; 17. Screw B; 18. Connecting rod; 19. Screw C; 20. Cylindrical pin; 21. Slider; 22. Workpiece A; 23. Fastening screw; 24. Workpiece B; 25. Dual-axis cylinder; 26. Guide rail B DETAILED DESCRIPTION

[0018] The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0019] like Figure 1 to Figure 4 As shown, a device for automatically tightening multiple screws simultaneously is used, which finally realizes the connection between workpiece A 22 and workpiece B 24 through multiple tightening screws 23. The torque is controlled at 7±0.1Nm. In order to meet the torque requirement, the torque of the fixed torque air screw 14 must be controlled at 7Nm, and it will automatically stop after reaching 7Nm. In the next cycle, a mechanism is required to reset the fixed torque air screw 14. The implementation process will be introduced.

[0020] The invention comprises a base plate 1, on which there is a sliding mechanism composed of a slider 21 and a guide rail B 26, the slider 21 is connected to a workpiece mounting plate 3, the workpiece mounting plate 3 is connected to a double-axis cylinder 25, the workpiece B 24 is positioned and mounted on the workpiece mounting plate 3, the workpiece A 22 is connected to the workpiece B 24 by a fastening screw 23 to form a workpiece combination, the workpiece combination moves forward and backward on the base plate 1 driven by the double-axis cylinder 25, when the workpiece combination reaches the correct position driven by the double-axis cylinder 25, the cylinder 2 presses the workpiece combination to prepare for the next step of fastening, after fastening, the cylinder 2 is released, the double-axis cylinder 25 drives the workpiece combination to move backward, the workpiece combination is removed, and a working cycle is completed.

[0021] The vertical plate is welded 4, and there is a sliding mechanism composed of a slider 21 and a guide rail A 5 on the vertical plate welded 4. The buffer plate assembly 11 and the screwdriver guide assembly 7 are fixed to the sliding mechanism by screws C 19. The driving cylinder 16 is fixed to the cylinder fixing plate 15. The cylinder fixing plate 15 is fixed to the vertical plate welded 4 by the action of screws B 17. The driving cylinder 16 is connected to the air screwdriver fixing plate 13 through a connecting rod 18. The fixed torque air screwdriver 14 is fixed to the air screwdriver fixing plate 13. The air screwdriver fixing plate 13 and the buffer plate assembly 11 are connected by connecting columns B 12 under the tightening of screws A 10. The buffer plate assembly 11 and the screwdriver guide assembly 7 are connected by connecting columns A 9 under the tightening of screws A 10. The screwdriver connecting sleeve 8 is connected to the buffer plate assembly 11 through a cylindrical pin 20. The screwdriver head 6 is placed in the screwdriver positioning sleeve 8. Therefore, under the drive of the driving cylinder 16, the screwdriver is moved on the guide rail A 5 ensures the correct position and moves up and down. Under the action of the control system, the multiple fastening screws 23 are tightened at a certain torque at the same time by controlling the on and off of the air;

[0022] The buffer plate assembly 11 is composed of a slider fixing plate 11a, a transmission shaft fixing plate 11b, a transmission shaft support seat 11c, a sleeve 11d, a spring A 11e, a transmission shaft 11f, a transmission shaft connecting sleeve 11g, a retaining ring 11h, a pin 11i, a push column 11j, a spring B 11k, a bearing A11l, a connecting column 11m and a screw F 11n, wherein the slider fixing plate 11a is connected to the transmission shaft fixing plate 11b by a screw D 7c, the screw F 11n fixes the transmission shaft support seat 11c on the transmission shaft fixing plate 11b, the transmission shaft 11f is supported by two bearings A11l, the sleeve 11d locates the axial position of the two bearings A11l, and the retaining ring 11h limits the axial movement of the bearing A. The pin shaft 11i has an interference fit with the transmission shaft connecting sleeve 11g and a clearance fit with the groove on the transmission shaft 11f. During the downward movement of the sliding mechanism, the spring A 11e is compressed, and the transmission shaft connecting sleeve 11g slides upward in the groove of the transmission shaft 11f, pushing the push column 11j to move upward, the push column 11j pushes the spring B 11k to move upward, and the spring B 11k pushes the connecting column 11m to move upward. The connecting column 11m contacts the reset switch in the fixed torque air screwdriver 14, the switch is turned on, the fixed torque air screwdriver 14 starts, and drives the screwdriver head 6 to work.

[0023] The screwdriver guide assembly 7 is composed of a screwdriver fixing plate 7a, a slider fixing plate A 7b, a screw D 7c, a bearing cover plate 7d, a screwdriver positioning sleeve 7e, a shaft retaining ring 7f, a bearing B 7g, and a screw E 7h. The screw D 7c fixes the screwdriver fixing plate 7a to the slider fixing plate A 7b, the screw E 7h fixes the bearing cover plate 7d to the screwdriver fixing plate 7a, and the shaft retaining ring 7f fixes the bearing B 7g to the screwdriver positioning sleeve 7e. The screwdriver head 6 is positioned during the rotation process to ensure accuracy and reliability during the tightening process.

[0024] The control system is composed of a solenoid valve, a PLC controller, a magnetic switch, etc., which controls the movement of the cylinder and the on and off of the fixed torque air screwdriver to achieve automatic control of the fastening device.

[0025] The positive effects of the present invention: The present invention drives the fixed torque air screwdriver 14 on the air screwdriver fixing plate 13, the buffer plate assembly 11, and the screwdriver head 6 of the screwdriver guide assembly 7 to automatically tighten multiple screws at the same time by driving the air cylinder 16 along the guide rail A 5, and combines the fixed torque function of the fixed torque air screwdriver 14 to achieve the consistency of the tightening torque. By using the multi-screw automatic tightening device to transfer and assemble one by one with a conventional handheld air screwdriver, 10 components of workpiece A 22 and workpiece B 24 are assembled continuously, and torque tests are performed. The test data is as follows: Figure 4 From Figure 4 It can be seen that the torque values ​​of the workpiece combinations assembled using the device of the present invention all meet the requirement of 7±0.1Nm, with a pass rate of 100%, while the pass rate of assembly using conventional handheld assembly means is only 20%. The present invention meets the requirements of assembly quality; compared with conventional assembly that can only tighten one screw at a time, the assembly efficiency is improved by 100%; there is no need to manually hold the air screwdriver, which reduces labor intensity.

[0026] The best configuration for implementing the present invention has been disclosed through the above description, but the present invention is not limited thereto. That is, in the present invention, specific embodiments are mainly illustrated and described, but those skilled in the art may make various modifications to the above-described embodiments in terms of shape, quantity, and other detailed configurations without departing from the technical concept and purpose of the present invention.

[0027] Therefore, the descriptions limiting the shapes, quantities, etc. disclosed above are illustrative descriptions for easier understanding of the present invention, and do not limit the present invention. Therefore, the descriptions under the names of parts outside some or all of the limitations of these shapes, quantities, etc. are also included in the present invention.

Claims

1. A device for automatically tightening multiple screws simultaneously, characterized in that: A bottom plate (1) is provided with a slider guide structure (21, 26), a double-axis cylinder (25), a workpiece mounting plate (3), and a cylinder (2). The workpiece mounting plate (3) is connected to the double-axis cylinder (25) and the slider (21). The workpiece is positioned and mounted on the workpiece mounting plate (3). The cylinder (2) presses the workpiece and moves forward and backward under the control of the control system. A vertical plate is welded (4). A pneumatic screwdriver fixing plate (13) is provided on the vertical plate welded (4). A slider guide structure (21, 5) is provided. A buffer plate assembly (11) and a screwdriver guide assembly (7) are fixed on the slider guide structure. The slider guide structure moves up and down on the guide rail A (5) to ensure the correct position under the drive of the driving cylinder (16). Under the control of the control system, multiple groups of screws are tightened simultaneously according to a certain torque by controlling the on and off of air. A fixed torque pneumatic screwdriver (14) is fixed on the pneumatic screwdriver fixing plate (13). The pneumatic screwdriver is connected to the transmission shaft (11f) through a connecting column (11m). The tightening torque reaches the set torque. The air screwdriver automatically stops when the screwdriver is in the next working cycle, and the fixed torque air screwdriver (14) needs to be reset before it can continue to work; the buffer plate assembly (11) is composed of a slider fixing plate (11a), a transmission shaft fixing plate (11b), a transmission shaft support seat (11c), a transmission shaft (11f), a bearing A (11l), and a spring A (11e), ensuring that the transmission shaft (11f) transmits torque to the screwdriver head (6) through the transmission shaft connecting sleeve (11g) and the screwdriver connecting sleeve (8), and realizing buffering when the screwdriver head (6) contacts the fastening screw (23); the tappet (11j), spring B (11k), connecting column (11m), pin shaft (11i), and transmission shaft connecting sleeve (11g) inside the transmission shaft (11f) form an automatic reset mechanism of the fixed torque air screwdriver (14); the control system is composed of a solenoid valve, a PLC controller, and a magnetic switch, and controls the movement of the cylinder and the on and off of the fixed torque air screwdriver (14), thereby realizing automatic control of the fastening device.

2. The multi-screw automatic fastening device according to claim 1, characterized in that The screwdriver guide assembly (7) is composed of a slider fixing plate A (7b), a screwdriver fixing plate (7a), a screwdriver positioning sleeve (7e), and a bearing B (7g), and ensures that the screwdriver head (6) is correctly positioned during operation.

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