Assembly method of torsion shear wrench

Abstract

The present invention relates to a torsion shear wrench which is compact in structure, easy to carry, and can realize one-time tightening and final tightening, and an assembly method thereof. The torsion shear wrench comprises: a power supply, a switch, a motor, a transmission mechanism, a speed change switching mechanism and an output mechanism. The motor drives the output mechanism through the transmission mechanism, and the switch is used to control the operation of the motor. The transmission mechanism comprises an intermediate shaft, a first gear, a second gear with a different number of teeth from the first gear, and a transmission shaft. The motor comprises a motor output shaft meshingly connected with a transmission gear on the intermediate shaft. The invention is characterized in that: the intermediate shaft is arranged in parallel with the transmission shaft, the speed change switching mechanism can selectively enable the transmission shaft to realize transmission connection with the intermediate shaft through the first gear or the second gear, and the transmission mechanism and the speed change switching mechanism are located in the same gear box.

Description

Technical Field

[0001] The invention relates to an electric tool, in particular to a torsion shear wrench for tightening high-strength bolts and an operating method thereof. Background Art

[0002] Torsion shear wrenches are mainly used in the steel structure installation industry, and are specially used to install high-strength bolts for steel structures. High-strength bolts can be divided into two types: torsion shear type and large hexagon type. The national standard torsion shear type high-strength bolts are M16, M20, M22, and M24, and the non-national standard torsion shear type bolts are M27 and M30. Generally, the tightening of torsion shear type high-strength bolts must go through two steps: initial tightening and final tightening, and each step requires strict torque requirements. In practice, when operators tighten torsion shear type high-strength bolts, they generally use an impact wrench or a fixed torque wrench to complete the initial tightening, and then use a torsion shear wrench to complete the final tightening. In actual operation environment, multiple bolts are required on the steel frame connection structure to form a bolt cluster. If the bolts are tightened one by one in sequence at one time, the problem of uneven tightening will occur. The correct operation method is to tighten each bolt of the bolt cluster once, that is, the initial tightening. When the tightening is completed once, all the bolts reach basically the same tightening torque, and then the bolts are finally tightened until the neck of the shear bolt is sheared off. Existing shear type electric wrenches can be divided into initial tightening shear type electric wrenches and final tightening shear type electric wrenches, which usually have only one transmission ratio output. The torque control range of existing initial tightening shear type wrenches is small and cannot cover the torque requirements of initial tightening and final tightening of high-strength bolts at the same time. The existing final tightening shear type electric wrenches do not control the torque and are based on the shearing of the neck of the shear type high-strength bolt, so they cannot be used for initial tightening of high-strength shear type bolts. Therefore, for the construction of torsion shear type high-strength bolts, an initial tightening torsion shear wrench is required, which can usually be replaced by an impact wrench or a fixed torque wrench, and a final tightening torsion shear wrench is also required. This increases the labor cost and the carrying burden of the construction workers, especially when working at heights, it is very inconvenient to carry two power tools.

[0003] Prior art

[0004] Patent Document 1: The Chinese patent authorization announcement number CN101053947B discloses a control method for an electric tightening machine for bolts and nuts. The control method of the electric tightening machine can be used to achieve: using a tightening machine to complete the first tightening and final tightening of shear-type bolts and nuts. However, the electric tightening machine is only suitable for tightening a special bolt with a shear washer, and the solution disclosed in the patent is only a control method, and does not disclose the mechanical structure of a tightening machine to complete the first tightening and final tightening. Moreover, since the difference between the first tightening torque and the final tightening torque required for the tightening of shear bolts and nuts is large, the final tightening torque is usually about twice the first tightening torque, which requires the output torque range of the electric tightening machine to be very large, but the existing torsion shear wrenches, including the solution disclosed in the patent, do not provide a good solution to solve this technical problem, that is, being able to output the first tightening torque and the final tightening torque at the same time.

[0005] Patent Document 2: U.S. Patent Grant Announcement No. US5816121 discloses a torsion shear wrench that can be powered by either a battery pack or an AC power supply. The torsion shear wrench can automatically switch between high speed and low torque and low speed and high torque, which can improve work efficiency and shorten the time to tighten a single bolt. In addition, the torsion shear wrench provided by the patent can increase the output speed when no load is applied and reduce the size of the switch. However, the torsion shear wrench lacks electronic torque detection and is not suitable for one-time tightening of torsion shear bolts. Summary of the invention

[0006] In view of this, the present invention provides an improved torsion shear wrench, a torsion shear wrench with an electronic torque control system capable of realizing high-speed and low-speed switching, and an assembly method thereof.

[0007] Compared with the existing torsion shear wrench, the torsion shear wrench of the present invention has a compact structure and low manufacturing cost, but has a larger output torque range, and can complete the primary tightening and final tightening of torsion shear type high-strength bolts by one machine.

[0008] To achieve the above purpose, the technical solution provided by the present invention is as follows:

[0009] A torsion shear wrench comprises: a power supply, a switch, a motor, a transmission mechanism, a speed change switching mechanism and an output mechanism, wherein the motor drives the output mechanism through the transmission mechanism, the switch is used to control the operation of the motor, the transmission mechanism comprises an intermediate shaft, a first gear, a second gear having a different number of teeth from the first gear and a transmission shaft, the motor comprises a motor output shaft meshingly connected with a transmission gear on the intermediate shaft, and is characterized in that: the intermediate shaft is arranged in parallel with the transmission shaft, the speed change switching mechanism can selectively enable the transmission shaft to achieve transmission connection with the intermediate shaft through the first gear or the second gear, and the transmission mechanism and the speed change switching mechanism are located in the same gear box.

[0010] A further improved solution is that the torsion shear wrench also includes an electronic torque control unit. In the single tightening mode, when the electronic torque control unit detects that the torque of the output mechanism reaches a preset value, the control unit cuts off the motor current.

[0011] A further improved solution is that the first gear and the second gear are respectively located on both sides of the transmission gear.

[0012] A further improved solution is that the axis of the motor output shaft is perpendicular to the axis of the intermediate shaft, and the transmission gear is a bevel gear.

[0013] A further improved solution is that the intermediate shaft is provided with a first tooth-shaped portion and a second tooth-shaped portion respectively meshing with the first gear and the second gear, and the diameter of the first tooth-shaped portion is greater than the diameter of the second tooth-shaped portion.

[0014] A further improved solution is that the speed change switching mechanism includes a paddle, which can drive a sleeve located on the transmission shaft to move, and the sleeve and the transmission shaft cannot rotate relative to each other.

[0015] A further improved solution is that two ends of the sleeve are provided with a flat structure or a spline structure, which can be selectively coupled to the flat structure or the spline structure of the first gear or the second gear.

[0016] The present invention also provides an assembly method for a torsion shear wrench, which is characterized by: first, the transmission shaft, the guide rod of the speed switching mechanism and the connecting plate of the gear box are connected and assembled; then the first gear, the sleeve, and the second gear are sequentially installed on the transmission shaft; the elastic element, the control plate B, the paddle, the control plate A, and the elastic element are sequentially inserted into the guide rod; then the housing of the gear box is connected to the connecting plate; finally, the intermediate shaft is installed in the gear box housing and passed through the transmission gear.

[0017] A further improved solution is that the paddle needs to be first inserted into the groove of the sleeve and then pass through the guide rod and the transmission shaft at the same time.

[0018] A further improved solution is that when connecting the gearbox housing and the connecting plate, in order to ensure the concentricity of the fourth bearing and the third bearing, a simulated intermediate shaft positioning connecting plate is first set in the gearbox housing; the outer circle of the simulated intermediate shaft is slightly larger than the outer circle of the intermediate shaft. After the gearbox housing and the connecting plate are assembled, the simulated intermediate shaft is taken out and then the intermediate shaft is installed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the whole electric torsion shear wrench of the present invention;

[0020] Figure 2is a cross-sectional view of the electric torsion shear wrench of the present invention;

[0021] Figure 3 It is a partial exploded view of the electric torsion shear wrench of the present invention;

[0022] Figure 4 The electric shear wrench gearbox of the present invention is assembled Figure 1 ;

[0023] Figure 5 The electric shear wrench gearbox of the present invention is assembled Figure 2 ;

[0024] Figure 6 The electric shear wrench gearbox of the present invention is assembled Figure 3 ;

[0025] Figure 7 The electric shear wrench gearbox of the present invention is assembled Figure 4 ;

[0026] Figure 8 The electric shear wrench gearbox of the present invention is assembled Figure 5 ;

[0027] Meaning of the reference symbols:

[0028] Motor; 2. Small bevel gear; 3. Transmission gear; 4. Intermediate shaft; 5. First gear; 6. Second gear;

[0029] Connecting plate; 8. Paddle; 9. Control plate A; 10. Eccentric protrusion; 11. Control plate B; 12. Elastic element B;

[0030] Guide rod; 14, sleeve; 15, transmission shaft; 16, first bearing; 17, fourth bearing

[0031] Fourth bearing inner hole; 18, receiving plate; 19, spiral retaining ring; 20, stop ring; 21, screw;

[0032] Internal gear ring; 23, clamping ring; 24, clamping ring; 25, gasket; 26, gasket; 27, elastic element A;

[0033] 1. gasket; 29. ​​retaining ring; 30. gasket; 31. gasket; 32. gasket; 33. second bearing;

[0034] 34. Simulated intermediate shaft; 35. Screw; 37. Third bearing; 38. Screw; 40. Knob;

[0035] 41. Electronic torque control unit; 41.1. Torque setting unit; 100. Gear box DETAILED DESCRIPTION

[0036] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0037] Reference Figures 1 to 3 The electric torsion shear wrench of the present invention shown in the figure comprises: a housing, a handle, a power supply, a switch, a motor 1, a gear box 100, a transmission mechanism, a speed change switching mechanism, an electronic torque control unit 41 and an output mechanism. The transmission mechanism and the speed change switching mechanism are located in the gear box 100, and the gear box 100 is composed of a gear box housing and a connecting plate 7.

[0038] The power source of the present invention can be a direct current power source, preferably a lithium battery pack, or an alternating current power source, and the motor 1 can be an electric motor or a pneumatic motor.

[0039] The transmission mechanism includes: a first bearing 16 , a transmission shaft 15 , a first gear 5 , a sleeve 14 , a second gear 6 , a second bearing 33 , an intermediate shaft 4 , a transmission gear 3 , a third bearing 37 and a fourth bearing 17 .

[0040] The transmission shaft 15 is rotatably fixed to the gear box 100 through the first bearing 16 and the second bearing 33. The sleeve 14 is slidably arranged on the transmission shaft 15. The diameter of the first gear 5 is smaller than that of the second gear 6. The first gear 5, the second gear 6 and the transmission shaft 15 can rotate relative to each other. The sleeve 14 cannot rotate relative to the transmission shaft 15. An annular groove is arranged on the outer side of the sleeve 14. Both sides of the sleeve 14 are arranged to form a flat structure or a spline structure that can be coupled and connected with the first gear 5 and the second gear 6. Of course, those skilled in the art can also think of using a polygonal structure to replace the flat structure to achieve the coupling connection between the sleeve 14 and the first or second gear.

[0041] The intermediate shaft 4 is arranged in parallel with the transmission shaft 15. The intermediate shaft 4 is provided with a first tooth-shaped portion 4.1 and a second tooth-shaped portion 4.2 which mesh with the first gear 5 and the second gear 6 respectively, and the diameter of the first tooth-shaped portion 4.1 is larger than the diameter of the second tooth-shaped portion 4.2. In another embodiment, the first and second tooth-shaped portions of the intermediate shaft 4 can also be replaced by a method of independent gears tightly connected to the intermediate shaft 4, or a flat method or a spline connection method. The intermediate shaft 4 is also provided with a transmission gear 3, which is flatly or splinedly connected to the intermediate shaft 4. Preferably, the first gear 5 and the second gear 6 on the transmission shaft 15 are located on the left and right sides of the transmission gear 3. Of course, it is also conceivable that the first gear 5 and the second gear 6 on the transmission shaft 15 are arranged on one side of the transmission gear 3. The two ends of the intermediate shaft 4 are rotatably fixed to the gear box 100 through the third bearing 37 and the fourth bearing 17.

[0042] The speed change switching mechanism includes: a knob 40, an eccentric protrusion 10, a paddle 8, a control plate A9, a control plate B11, a guide rod 13, and elastic elements A and B. The elastic element A27, the control plate A9, the paddle 8, the control plate B11, and the elastic element B12 are sequentially arranged along the guide rod 13, and the eccentric protrusion 10 is located between the control plate A9 and the control plate B11. The knob 40 is connected to the eccentric protrusion 10. The paddle 8 can be movably inserted into the groove of the sleeve 14.

[0043] The electric torsion shear wrench of the present invention has only two gears. In the second gear, the eccentric protrusion 10 abuts against the control plate A9, so that the control plate A9 moves to the left along the axis of the transmission shaft 15. At this time, the control plate B11 will prompt the paddle 8 to move to the left along the axis of the transmission shaft 15 under the action of the elastic element B12, so that the flat position of the sleeve 14 is coupled with the flat position of the first gear 5 to achieve high-speed and low-torque output; in the first gear, the eccentric protrusion 10 abuts against the control plate B11, so that the control plate B11 moves to the right along the axis of the transmission shaft 15. At this time, the control plate A9 prompts the paddle 8 to move to the right along the axis of the transmission shaft 15 under the action of the elastic element A27, and the coupling connection between the sleeve 14 and the first gear 5 is disconnected. At the same time, the flat position of the sleeve 14 is coupled with the flat position of the second gear 6. At this time, the meshing connection between the second gear 6 and the second tooth-shaped portion 4.2 drives the transmission shaft 15 to rotate through the sleeve 14 to achieve low-speed and high-torque output.

[0044] Of course, other structures of the speed switching mechanism may also be used. For example, in another embodiment, the speed switching mechanism includes: a knob 40, an eccentric protrusion 10 and a paddle 8. The paddle 8 abuts against the eccentric protrusion 10. When the knob 40 is rotated, the paddle 8 moves left and right under the action of the eccentric protrusion 10, thereby driving the sleeve 14 to slide along the transmission shaft 15 (not shown in the figure).

[0045] The axis of the motor output shaft is preferably arranged perpendicular to the axis of the intermediate shaft 4. A small bevel gear 2 is provided at the end of the output shaft of the motor 1 and meshes with a transmission gear 3 on the intermediate shaft 4. The transmission gear 3 is a bevel gear.

[0046] With this layout, the gearbox is made into an integrated type, which is beneficial to cost control and positioning accuracy control of key transmission components.

[0047] In another embodiment, the axis of the motor output shaft can also be arranged parallel to the axis of the intermediate shaft 4 , and a cylindrical gear is provided at the end of the motor output shaft, which is meshed and connected with the cylindrical transmission gear 3 on the intermediate shaft 4 .

[0048] The electronic torque control unit 41 of the electric torsion shear wrench detects the current value flowing through the motor 1. When the current value exceeds the preset value, it indicates that the torque reaches the preset value, and the power supply is cut off to stop the rotation of the motor 1. Specifically, during a tightening operation, the user first needs to set a torque value through the torque setting unit 41.1 of the electronic torque control unit 41. The torque setting unit is preferably a potentiometer. The change in the resistance value is transmitted to the control unit through the data conversion circuit, and is converted into a torque value after calculation. The torque setting is completed. When the user uses the torsion shear wrench to tighten the bolt once, the current detection element of the electronic torque control unit 41 continuously detects the current value of the motor, and transmits the changing current value to the control unit through the data conversion circuit, and converts it into a torque value. Once the detected torque value reaches the torque value set by the user, the control unit sends a control signal to cut off the power supply of the motor 1.

[0049] In another embodiment, the electronic torque control unit 41 can also realize torque control by detecting the torque of the inner gear ring of the output mechanism and judging whether the detected torque is greater than or equal to the preset torque value of the tool. Specifically, during a tightening operation, the user first needs to rotate the torque setting unit 41.1 to complete the torque setting. Secondly, the torque detection unit of the electronic torque control unit 41 detects the torque of the inner gear ring in the output mechanism through a sensor. The sensor is a torque sensor, such as a strain resistor. The inner gear ring will deform during a tightening operation. At this time, the strain resistor connected to the inner gear ring will also deform, resulting in a change in resistance value, which is transmitted to the control unit through a data conversion circuit and converted into a torque value. When the torque value reaches or exceeds the torque value set by the user, the control unit sends a control signal to cut off the power supply of the motor 1. In addition, other pressure sensors or photoelectric sensors can also be used to detect the output torque. During the final tightening, the electronic torque control unit 41 will not start working.

[0050] Because the gearbox housing is an integrated arrangement, the intermediate shaft 4 is inserted into the bearing hole of the third bearing 37 on one side of the gearbox 100. During the process, the transmission gear 3 is installed from the opening of the gearbox 100 and slid onto the intermediate shaft 4. Then the intermediate shaft 4 is slidably inserted into the fourth bearing 17 of the connecting plate 7.

[0051] Reference Figure 4 Assembly of the electric shear wrench shown Figure 1 First, press the transmission shaft 15 onto the first bearing 16; press the first bearing 16, the fourth bearing 17, and the guide rod 13 into the connecting plate 7 to form an assembly a.

[0052] Reference Figure 5 Assembly of the electric shear wrench shown Figure 2, the receiving plate 18, the spiral retaining ring 19, the stop ring 20 and the component a are sequentially installed in the inner gear ring 22, and then connected into one by the screws 21 to form the component b.

[0053] Reference Figure 6 Assembly of the electric shear wrench shown Figure 3 , insert the gasket 31, the second gear 6, the gasket 30, the collar 29, the sleeve 14, the gasket 32, the first gear 5, and the gasket 28 on the transmission shaft 15 of component b in sequence; set the collar 23 on the guide rod 13 of component b, and then insert the elastic element B12, the control plate B11, the gasket 25, the paddle 8, the gasket 26, the control plate A9, the elastic element A27, and the collar 24 in sequence. In the above assembly, the paddle 8 is required to be first inserted into the annular groove of the sleeve 14, and then inserted at the same time. Preferably, the inner gear ring 22 of component c should be placed downward to prevent the parts from falling out.

[0054] Reference Figure 7 Assembly of the electric shear wrench shown Figure 4 , the third bearing 37 is press-fitted in the gearbox 100, the simulated intermediate shaft 34 is assembled, the outer diameter 34.2 of the simulated intermediate shaft is slidably fitted with the corresponding bearing hole of the gearbox 100, and fixed by bolts 38; the outer diameter 34.1 of the simulated intermediate shaft is designed to be able to slide into the inner hole 17.1 of the fourth bearing, and is slightly larger than the outer diameter 4.3 of the intermediate shaft. Preferably, the outer diameter 4.3 of the intermediate shaft 4 is about 0.01mm smaller than the outer diameter 34.1 of the simulated intermediate shaft. In this way, the concentricity of the fourth bearing 17 and the third bearing 37 can be ensured. Sliding assembly c is installed into assembly d, and after fastening the connecting screws 35, assembly e is formed;

[0055] Reference Figure 8 Assembly of the electric shear wrench shown Figure 5 , take out the simulated intermediate shaft assembly from component e, then press-fit the third bearing 37 on the intermediate shaft 4, and slide it into the gear box. At the same time, the transmission gear 3 is installed from the opening 100.1 of the main reduction box and slides onto the intermediate shaft 4. Then the intermediate shaft 4 is inserted into the inner hole 17.1 of the fourth bearing; drive the end screw 38 to lock the intermediate shaft, and finally install the shift knob 40.

[0056] The present invention is not limited to the above specific implementations. Those skilled in the art can easily understand that there are many alternatives to the present invention without departing from the principle and scope of the present invention. The protection scope of the present invention shall be subject to the content of the claims.

Claims

1. A method for assembling a torsion shear wrench, the torsion shear wrench comprising: a power supply, a switch, a motor (1), a transmission mechanism, a speed change switching mechanism and an output mechanism, the motor (1) drives the output mechanism through the transmission mechanism, the switch is used to control the operation of the motor (1), the transmission mechanism comprises an intermediate shaft (4), a first gear (5), a second gear (6) having a different number of teeth from the first gear (5) and a transmission shaft (15), the motor (1) comprises a motor output shaft meshingly connected with a transmission gear (3) on the intermediate shaft (4), characterized in that : the intermediate shaft (4) is arranged in parallel with the transmission shaft (15); the speed change switching mechanism can selectively enable the transmission shaft (15) to achieve transmission connection with the intermediate shaft (4) through the first gear (5) or the second gear (6); the transmission mechanism and the speed change switching mechanism are located in the same gear box (100); It also includes an electronic torque control unit (41). In a single tightening mode, when the electronic torque control unit (41) detects that the torque of the output mechanism reaches a preset value, the electronic torque control unit (41) cuts off the current of the motor (1); The first gear (5) and the second gear (6) are respectively located on two sides of the transmission gear (3); The axis of the output shaft of the motor (1) is perpendicular to the axis of the intermediate shaft (4), and the transmission gear (3) is a bevel gear; The intermediate shaft (4) is provided with a first tooth-shaped portion and a second tooth-shaped portion respectively meshing with the first gear (5) and the second gear (6), and the diameter of the first tooth-shaped portion is greater than the diameter of the second tooth-shaped portion; The speed change switching mechanism comprises a paddle (8), the paddle (8) can drive a sleeve (14) located on the transmission shaft (15) to move, and the sleeve (14) and the transmission shaft (15) cannot rotate relative to each other; The sleeve (14) is provided with a flat structure or a spline structure at both ends, which can be selectively coupled to the flat structure or the spline structure of the first gear (5) or the second gear (6); The assembly method of the torsion shear wrench comprises the following steps: firstly, the transmission shaft (15), the guide rod (13) of the speed change switching mechanism and the connecting plate (7) of the gear box (100) are connected and assembled; then, the second gear (6), the sleeve (14) and the first gear (5) are sequentially installed on the transmission shaft (15); the elastic element B (12), the control plate B (11), the paddle (8), the control plate A (9) and the elastic element A (27) are sequentially inserted into the guide rod (13); then, the housing of the gear box is connected to the connecting plate (7); finally, the intermediate shaft (4) is installed in the housing of the gear box and passed through the transmission gear (3); The paddle (8) must first be inserted into the groove of the sleeve (14) and then pass through the guide rod (13) and the transmission shaft (15) at the same time; When the gearbox housing is connected to the connecting plate (7), a simulated intermediate shaft (34) is first arranged in the gearbox housing; the second outer circle (34.2) of the simulated intermediate shaft is slidably matched with the corresponding bearing hole of the gearbox (100) and fixed by bolts (38); the first outer circle (34.1) of the simulated intermediate shaft is designed to be able to slide into the inner hole (17.1) of the fourth bearing; the first outer circle (34.1) of the simulated intermediate shaft is slightly larger than the outer circle (4.3) of the intermediate shaft. After the gearbox housing and the connecting plate (7) are assembled, the simulated intermediate shaft is taken out and then the intermediate shaft (4) is installed.

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