Mechanical digital torque wrench

Abstract

The present invention discloses a mechanical digital display torque wrench, characterized in that it includes an elastic shaft assembly, a sleeve, and a guide sleeve. The elastic shaft assembly includes an elastic shaft and a strain gauge. The front end of the elastic shaft is rigidly connected to the wrench head. The rear end of the elastic shaft is inserted into the front end cavity of the sleeve and is hinged thereto via a pin. The guide sleeve is inserted into the sleeve and forms a clearance fit with the inner wall of the sleeve. A set of tripping mechanisms is installed in the guide sleeve. When the applied torque of the wrench reaches a set value, the tripping mechanism can cause the wrench to feel slippery and simultaneously strike the sleeve to emit a sound. The outer wall of the sleeve is equipped with an electronic component for torque setting, display, sound and light alarm, and control of the tripping mechanism. The present invention has the accuracy and torque setting, display, and sound and light alarm functions of a digital display torque wrench, as well as the slipping feel and sound alarm functions of a mechanical torque wrench, and has high working efficiency and high precision.

Description

Technical Field

[0001] The invention belongs to the technical field of torque wrenches and relates to a mechanical digital display fixed torque wrench. Background Art

[0002] Traditional mechanical click torque wrenches consist of a wrench head, a wrench rod assembly, a lever assembly, a main spring, a scale assembly, an adjustment bolt assembly, and an adjustment wheel or sliding lever handle. They detect torque acting on the wrench head using the lever balance principle. Adjusting the main spring compression with the adjustment wheel changes the torque wrench's output torque. This allows for torque pre-setting, a mechanical click alarm, a slipping feel, and a scale line display. However, due to the significant influence of the elastic main spring on this wrench's elastic element, its accuracy is low and it lacks a digital display. Traditional digital torque wrenches consist of a wrench head, an elastic shaft assembly, electronic components, and a battery. Torque is detected by measuring the voltage change of a strain gauge attached to the elastic shaft in direct proportion to the torque acting on the ratchet wheel of the wrench head. This allows for torque pre-setting, audible and visual alarms, and a digital display. However, these wrenches lack a mechanical slipping feel, are prone to overload, and require only slow force application, resulting in low efficiency. Therefore, it is necessary to propose an efficient and high-precision torque wrench that can ensure the accuracy and function of a digital torque wrench and the alarm and slip function of a mechanical torque wrench. Summary of the Invention

[0003] The purpose of the present invention is to overcome the defects of low precision of existing mechanical click torque wrenches and slow force application and low working efficiency of existing digital torque wrenches, and to provide a torque wrench with high working efficiency and high precision.

[0004] The technical solution to achieve the above-mentioned purpose is: a mechanical digital display torque wrench, characterized in that it includes an elastic shaft assembly, a sleeve and a guide sleeve, the elastic shaft assembly includes an elastic shaft and a strain gauge, the front end of the elastic shaft is rigidly connected to the wrench head, the rear end of the elastic shaft is inserted into the front end cavity of the sleeve and hinged with it through a pin shaft, the guide sleeve is inserted in the sleeve and forms a clearance fit with the inner wall of the sleeve, a set of tripping mechanism is installed in the guide sleeve, and when the applied torque of the wrench reaches a set value, the tripping mechanism can make the wrench feel slippery and simultaneously knock the sleeve to make a sound, and the outer wall of the sleeve is installed with electronic components for torque setting, display, sound and light alarm, and control of the tripping mechanism.

[0005] The tripping mechanism includes a lever, a knocking block, a disengagement block, a flip block, a telescopic electromagnet and an electromagnet cap. The lever, knocking block, disengagement block, flip block and telescopic electromagnet are hinged on the tube wall of the guide sleeve from the front end to the rear end through a pin shaft in sequence in the guide sleeve, and form a corresponding overlap form in which the front and rear parts of each component are overlapped in sequence. The front end of the lever is overlapped on the rear end of the elastic shaft, the electromagnet cap is sleeved on the core shaft of the telescopic electromagnet and abuts against the back of the flip block, and the telescopic electromagnet is electrically connected to the driving circuit of the electromagnet on the communication circuit board in the electronic component.

[0006] The working mechanism or principle of the present invention is:

[0007] When the wrench starts to load the bolt with torque until the torque setting value is reached, the rear end of the elastic shaft overlaps with the front end of the lever, and the rear lever, knock block, disengagement block, and flip block are rigidly overlapped in sequence. At this time, the acquisition circuit on the communication circuit board in the electronic component collects the strain output voltage on the elastic shaft and converts it into torque through the main control circuit board and displays it on the LCD screen.

[0008] When the loaded torque reaches the set value, the main control circuit board on the electronic component transmits the torque to the display and sends a switch signal to the drive circuit on the communication circuit board to drive the core shaft of the electromagnet to extend, pushing the flip block to rotate clockwise along its hinge pin. The rotation of the flip block drives the detachment block to rotate counterclockwise along its hinge pin. During the rotation process, the detachment block disengages from the overlap of the detachment block and the knocking block. At this time, under the action of the elastic shaft and lever, the knocking block rotates counterclockwise along its hinge pin and knocks on the pipe wall, emitting a "click" sound alarm. At the same time, when the detachment block and the knocking block are disengaged at the moment of the overlap, due to the loss of force at the rear end of the lever, the lever will rotate clockwise, and the wrench will produce a slippery feeling.

[0009] When the loading on the wrench stops, the telescopic electromagnet automatically retracts due to its own spring, and the disengagement block and the flip block automatically reset under the action of the spring at the corresponding position; at the same time, the knocking block also automatically resets under the action of the spring at the corresponding position.

[0010] The invention has the precision and torque setting, display and sound and light alarm functions of a digital torque wrench, as well as the slipping feel and sound alarm function of a mechanical torque wrench, and has high working efficiency and high assembly precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0012] Figure 2 It is a structural schematic diagram of the elastic shaft assembly in the present invention.

[0013] Figure 3 yes Figure 1Schematic diagram of the structure of the internal tripping mechanism of the guide sleeve.

[0014] Figure 4 yes Figure 1 Schematic diagram of the structure of the elastic shaft.

[0015] Figure 5a yes Figure 1 Schematic diagram of the front structure of the guide sleeve.

[0016] Figure 5b yes Figure 5a Bottom view of the guide sleeve shown.

[0017] Figure 5c yes Figure 5a Top view of the guide bushing shown.

[0018] Figure 6 It is a schematic structural diagram of the sleeve parts of the present invention.

[0019] Figure 7a yes Figure 1 Schematic diagram of the structure of the middle lever.

[0020] Figure 7b yes Figure 7a A perspective view of the lever shown.

[0021] Figure 8 yes Figure 1 Schematic diagram of the structure of the knock block.

[0022] Figure 9 yes Figure 8 A perspective view of the striking block shown.

[0023] Figure 10 yes Figure 1 Schematic diagram of the structure of the separation block.

[0024] Figure 11 yes Figure 10 A perspective view of the breakaway block is shown.

[0025] Figure 12 yes Figure 1 Schematic diagram of the flip block structure.

[0026] Figure 13 yes Figure 12 A perspective view of the flip block shown.

[0027] In the figure: 1. Elastic shaft assembly, 2. Sleeve, 2-1. Rectangular window, 2-2. Threaded through hole, 2-3. Countersunk hole, 2-4. Small hole, 2-5. Small hole, 2-6. Large hole, 4. Large rivet, 5. Small rivet, 6. Thin washer, 7. Thick washer, 8. Elastic shaft, 8-1. Docking hole, 8-2. Large rivet hole, 8-3. Flat surface, 8-4. Inclined surface, 9. Strain gauge, 10. Terminal block, 11. Compensating resistor, 12. Guide sleeve, 12-1. Short rectangular slot, 12-2. Long rectangular slot, 12-3, 12-4, 12-5, 12-6, 12-7. Pin hole, 12-8. Shallow countersunk hole, 12-9. Deep countersunk hole, 12-10. Shallow countersunk hole, 13. Lever, 13-1. Bushing through hole, 13-2. Arc surface, 13-3. Lower plane, 14. Knocking block, 14-1. Through hole, 14-2. Blind hole, 14-3. Inclined surface, 14-4. Knocking surface, 14-5. Plane, 14-6. Step, 15. Disengagement block, 15-1. Through hole, 15-2. Fan-shaped lower end surface, 15-3. Lower plane of the right end, 15-4. Limiting surface, 15-5. Spring hole, 16. Flip block, 16-1. Through hole, 16-2. Step, 16-3. Right end plane, 16-4. Right end plane, 17. Telescopic electromagnet, 18. Bushing, 19. Spring, 20. Pin, 21. Pin I, 22. Electromagnet cap, 23. Pin II, 24. Pin III. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings.

[0029] like Figure 1 As shown, the present invention includes an elastic shaft assembly 1, a sleeve 2 and a guide sleeve 12, and a set of tripping mechanisms installed in the guide sleeve 12.

[0030] like Figure 2 and Figure 4 As shown, the elastic shaft assembly 1 comprises an elastic shaft 8, a strain gauge 9, a terminal block 10, and a compensation resistor 11. The elastic shaft 8 is a stepped shaft. On the stepped surface at its far left end, or front end, there is a docking hole 8-1 for the wrench adapter. The right end of the stepped surface is a combination of two continuous symmetrical planes and a circular surface. On the second symmetrical plane, there is a large rivet hole 8-2. At its far right end, or tail end, there is a tapered shaft with an inclined plane 8-4. Two symmetrical planes 8-3 are located on the middle surface of the elastic shaft 8. The strain gauge 9, terminal block 10, and compensation resistor 11 are adhesively affixed to the two symmetrical planes 8-3 on the middle surface. The strain gauge 9 and compensation resistor 11 form a full-bridge circuit. The terminal block 10 is used for bridge assembly and for welding power input and signal output leads. The full-bridge circuit is used to detect changes in signal output voltage caused by changes in the force applied to the elastic shaft 8.

[0031] like Figure 6As shown, the sleeve 2 is a rectangular tube. It has a rectangular window 2-1 in the center, with four threaded holes 2-2 at the bottom for mounting electronic components. At the right end are four 90-degree countersunk holes 2-3 for mounting battery components. At the left end are two small holes 2-4 and 2-5, and one large hole 2-6. The two small holes are for large rivets 4 and small rivets 5, and the large hole 2-6 is a positioning hole for mounting the handle.

[0032] like Figure 5a 、 Figure 5b and Figure 5c As shown, the guide sleeve 12 is a rectangular block with five pin holes 12-3, 12-4, 12-5, 12-6 and 12-7 on its front side. A U-shaped groove is opened at the lower end of the left side of the side, and the right end of the U-shaped groove is a stepped through hole. Rectangular grooves 12-1 and 12-2 are opened at both ends of the right side of the side. The rectangular groove has two shallow countersunk holes 12-8 and 12-10 and a deep countersunk hole 12-9. Four wire grooves are opened at the four outer corners of the guide sleeve 12.

[0033] like Figure 1 、 Figure 3 and Figure 5a As shown, the guide sleeve 12 is inserted into the sleeve 2 and forms a small clearance fit with the inner wall of the sleeve 2. During the installation process, the spring 19 is compressed by the thin washer 6 and inserted into the shallow countersunk holes 12-8 and 12-10 of the guide sleeve 12, and the thick washer 7 is inserted into the hole 12-9 of the guide sleeve 12.

[0034] like Figure 1 As shown, the tripping mechanism includes a lever 13 , a knocking block 14 , a disengagement block 15 , a flip block 16 , a telescopic electromagnet 17 and an electromagnet cap 22 .

[0035] like Figure 7a and Figure 7b As shown, the lever 13 is a T-shaped flat block with a bushing through hole 13-1 near the left side; Figure 8 and Figure 9 As shown, the striking block 14 is also a T-shaped block, with a through hole 14-1 on the left side of the plane. At both ends of the through hole 14-1 are circular steps 14-6 for reducing friction during rotation. There is a platform at the lower left end and a blind hole 14-2 in the middle of the platform. Figure 10 and Figure 11 As shown, the disengagement block 15 is an L-shaped plate with an arc, a through hole 15-1 on the left side of the plate, and stepped surfaces at both ends of the hole for reducing friction during rotation. The lower part of the left side is a fan-shaped plate with a notch, and a blind hole 15-5 is provided on the upper plane of the plate; Figure 12 and Figure 13As shown, the flip block 16 is an L-shaped block, the upper left side of which is an arc, the center of the arc is a through hole 16-1, both ends of the hole have a step circle for reducing friction during rotation, and the lower left end is processed with a platform 16-4.

[0036] like Figure 3 、 Figure 7a and Figure 5a As shown, the bushing through hole 13-1 on the lever 13 is coaxially connected to the pin shaft hole 12-3 on the guide sleeve 12 through the bushing 18, and the lever 13 can rotate around the bushing; Figure 3 and Figure 8 As shown, the through hole 14-1 on the knocking block 14 is coaxially connected to the pin hole 12-4 on the guide sleeve 12 through the pin 20. The knocking block 14 can rotate around the pin 20. The inclined surface 14-3 on the upper left end of the knocking block 14 is in line contact with the lower plane 13-3 on the right end of the lever 13. The plane of the raised part of the right end of the knocking block 14 is the knocking surface 14-4. The spring 19 is installed in the blind hole 14-2;

[0037] like Figure 3 Figure 10 and Figure 11 As shown, the disengagement block 15 is coaxially connected to the pin hole 12-5 on the guide sleeve 12 through the pin shaft I 21. The fan-shaped lower end surface 15-2 of the disengagement block 15 is in line contact with the plane 14-5 of the right end of the knocking block 14. The limiting surface 15-4 at the right end of the disengagement block 15 is limited by the pin shaft II 23. The pin shaft II 23 is installed in the pin hole 12-6 of the guide sleeve 12. A spring 19 with calcium-based grease is installed in the hole 15-5 on the upper plane of the disengagement block 15. Figure 3 Figure 12 and Figure 13 As shown, the flip block 16 is coaxially connected to the pin hole 12-7 of the guide sleeve 12 through the through hole 16-1 via the pin III 24, and its left end platform 16-4 contacts the lower right end plane 15-3 of the disengagement block 15, and the right end plane 16-3 contacts the front end of the electromagnet cap 22; Figure 3 As shown, the telescopic electromagnet 17 is fixed in the U-shaped groove on the guide sleeve 12 with two cross screws and is electrically connected to the electromagnet drive circuit on the communication circuit board in the electronic component; the electromagnet cap 22 is a stepped shaft with a blind hole at the large end. The electromagnet cap 22 is sleeved on the core shaft of the telescopic electromagnet 17 through the blind hole and passes through the stepped through-hole of the guide sleeve 12.

[0038] like Figure 1 and Figure 4 As shown, the elastic shaft assembly 1 is inserted into the sleeve 2, the large rivet hole 8-2 on the elastic shaft 8 is coaxial with the small hole 2-4 in the sleeve 2, and is fixed with a large rivet 4. The elastic shaft assembly 1 can rotate around the rivet 4.

[0039] like Figure 1 、 Figure 3 and Figure 6 As shown, the inner hole of the bushing 18 is coaxially connected to the small hole 2-5 in the sleeve 2 and fixed with a small rivet 5; the arc surface 13-2 below the left end of the lever 13 overlaps the inclined plane 8-4 of the elastic shaft 8.

Claims

1. A mechanical digital display torque wrench, characterized by: The invention comprises an elastic shaft assembly, a sleeve and a guide sleeve, wherein the elastic shaft assembly comprises an elastic shaft and a strain gauge, the front end of the elastic shaft is rigidly connected to the wrench head, the rear end of the elastic shaft is inserted into the front end cavity of the sleeve and is hinged to the sleeve through a pin shaft, the guide sleeve is inserted into the sleeve and forms a clearance fit with the inner wall of the sleeve, a set of tripping mechanism is installed in the guide sleeve, and when the force torque of the wrench reaches the set value, the tripping mechanism can make the wrench feel slippery and knock the sleeve to make a sound at the same time, the outer wall of the sleeve is equipped with torque setting, display and sound and light alarm, and electronic components for controlling the tripping mechanism; the tripping mechanism comprises a lever, a knocking block, a disengagement block, a flip block, a telescopic electromagnet and an electromagnetic The iron cap, the lever, knocking block, disengagement block, flip block, and telescopic electromagnet are hinged on the tube wall of the guide sleeve from its front end to its rear end through the pin shaft in sequence, and the front and rear parts of each component are overlapped in sequence, and the front end head of the lever is overlapped on the rear end of the elastic shaft; the knocking block is a T-shaped block with a platform at the lower left end and a blind hole in the middle of the platform, and a spring is installed in the blind hole; the disengagement block is an L-plate with an arc, a blind hole on the upper plane of the plate, and a spring is installed in the blind hole; the electromagnet cap is mounted on the core shaft of the telescopic electromagnet and abuts against the back of the flip block, and the telescopic electromagnet is electrically connected to the driving circuit of the electromagnet on the communication circuit board in the electronic component.

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