Compression-torsion composite force transducer for robot screw locking machine

Abstract

The utility model discloses a pressure-torsion composite force transducer for a robot screw locking machine, which comprises an upper fixed end and a lower fixed end, four beam torque structures which are arranged along the circumference of the upper fixed end in an array manner are arranged between the upper fixed end and the lower fixed end, and a pressure measuring structure is fixedly arranged in the lower fixed end; a protective shell is further fixedly arranged between the upper fixing end and the lower fixing end and arranged on the outer sides of the four beam torque structures in a sleeving mode, and the height of the protective shell is six seventh of the distance from the bottom of the upper fixing end to the top of the lower fixing end. The device has the advantages that static torque and pressure measurement are combined, the stability is good, the service life is long, the cost is low, the use is simple, the installation is convenient and fast, and the device can be well matched with a servo motor.

Description

Technical Field

[0001] The utility model relates to the field of sensors, in particular to a compression-torsion composite force sensor used for a robot screw locking machine. Background Art

[0002] Traditional manual screw tightening products have low precision and rely on the experience of the screw tightener, which often results in substandard torque. Subsequently, screw tightening machines emerged, whose core control program is nothing more than an external dynamic torque testing system or an internal integrated static torque testing system. Although both measurement methods can effectively control the torque of the screw tightening, neither can actually control the amount of pressure applied to the screw. If the downward pressure of the tightening equipment is simply controlled by adjusting the displacement, this method will not be intelligent enough when using different types of screws or facing different working conditions. Secondly, the operating accuracy is insufficient, which can easily increase the product rejection rate.

[0003] Currently, many equipment manufacturers choose to use visual cameras to control the downward pressure of the robotic arm through big data algorithms. However, the main problem faced by this method is that the development cost is too high. Ordinary screw-locking robots simply cannot afford such a high cost. In addition, visual cameras can only vaguely control the position and cannot perceive the force value. Therefore, it is very necessary to add pressure value measurement and feedback at an appropriate cost on the basis of the original torque measurement. Utility Model Content

[0004] The purpose of the utility model is to provide a compression-torsion composite force sensor for a robot screw locking machine, which combines static torque and pressure measurement, has the advantages of good stability, long life, low cost, simple use, convenient installation, and can be well adapted to servo motors.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

[0006] A compression-torsion composite force sensor for a robotic screw-locking machine comprises an upper fixed end and a lower fixed end, wherein four beam torque structures are arranged in an array along the circumference of the upper fixed end between the upper and lower fixed ends, and a pressure measurement structure is fixed inside the lower fixed end;

[0007] A protective shell is also fixed between the upper fixed end and the lower fixed end. The protective shell is sleeved on the outside of the four beam torque structures. The height of the protective shell is six-sevenths of the distance from the bottom of the upper fixed end to the top of the lower fixed end.

[0008] The preferred options are as follows:

[0009] Preferably: the upper fixed end and the lower fixed end are both square blocks, the bottom of the upper fixed end is fixedly provided with a first annular mounting block, the top of the lower fixed end is fixedly provided with a second annular mounting block, the four beam torque structures are fixedly located between the first mounting block and the second mounting block, and the protective shell is fixedly sleeved on the outer wall of the second mounting block.

[0010] Preferably, each of the beam torque structures includes an elastic body and a first resistance strain sensor, each of the elastic bodies is a vertical rectangular block, and a first resistance strain sensor is fixedly provided on one side of the inner side of the upward fixed end of each of the elastic bodies.

[0011] Preferably, a circular groove is provided at the bottom of the lower fixed end, a plurality of second resistance strain sensors are arranged in an array on the inner top wall of the circular groove, and a circular cover is fixedly provided at the bottom of the lower fixed end.

[0012] Preferably, a first locking wire nut is fixedly provided on the front side of the protective housing, a first cable is provided in the first locking wire nut, and the first cable is electrically connected to the four first resistance strain sensors.

[0013] Preferably, a second locking wire nut is fixedly provided on the front side of the lower fixed end, a second cable is provided in the second locking wire nut, and the second cable is electrically connected to a plurality of second resistance strain sensors.

[0014] Preferably: the protective shell includes two semi-circular ring blocks, the lower end of each semi-circular ring block is provided with a plurality of circular through-holes in a circumferential array, the side wall array of the second mounting block is provided with a plurality of threaded holes corresponding to the plurality of circular through-holes, each of the circular through-holes is provided with a countersunk screw, and each of the countersunk screws is threadedly connected to its corresponding threaded hole.

[0015] Preferably, the inner diameter of the cover plate is nine-tenths of the inner diameter of the annular groove, a circular groove is provided at the bottom of the lower fixed end, the inner diameter of the groove is consistent with the inner diameter of the cover plate, and the cover plate is fixedly connected in the groove.

[0016] In summary, the present invention has the following beneficial effects:

[0017] 1. Through the setting of four torque measurement structures, it is possible to measure the real-time working torque of the tightening robot and provide feedback;

[0018] 2. Through the setting of the pressure measurement structure, it is possible to measure the real-time contact pressure of the tightening robot and provide feedback;

[0019] 3. The second mounting block and the protective housing can prevent the first resistance strain gauge sensor from being damaged by some harsh working conditions.

[0020] 4. Through the arrangement of the first locking wire nut and the second locking wire nut, the signals of the beam torque structure and the pressure measurement structure can be collected independently without interfering with each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 1 is a schematic diagram of the overall structure of the embodiment;

[0022] Figure 2 is an exploded view of an embodiment;

[0023] Figure 3 is a bottom side view of an exploded view of an embodiment.

[0024] In the figure, 1. upper fixed end; 2. lower fixed end; 3. beam torque structure; 4. pressure measurement structure; 5. protective shell; 111. first mounting block; 211. second mounting block; 212. cover plate; 213. countersunk screw; 311. elastomer; 312. first resistance strain sensor; 313. first locking wire nut; 314. first cable; 411. second resistance strain sensor; 412. second locking wire nut; 413. second cable. DETAILED DESCRIPTION

[0025] The present invention will be described in further detail below with reference to the accompanying drawings.

[0026] Identical components are denoted by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "upper," and "lower" used in the following description refer to directions in the accompanying drawings, and the terms "bottom," "top," "inner," and "outer" refer to directions toward or away from the geometric center of a particular component, respectively.

[0027] A compression-torsion composite force sensor for a robot screw-locking machine, such as Figure 1-3 As shown, it includes an upper fixed end 1 and a lower fixed end 2. Four beam torque structures 3 are arranged in an array along the circumference of the upper fixed end 1 between the upper fixed end 1 and the lower fixed end 2. A pressure measuring structure 4 is fixed inside the lower fixed end 2. The beam torque structure 3 is used to measure the real-time working torque of the leading robot and provide feedback. The pressure measuring structure 4 is used to measure the real-time working contact pressure of the tightening robot and provide feedback.

[0028] The upper fixed end 1 and the lower fixed end 2 are both square blocks, and mounting holes are provided at the four corners of the upper fixed end 1 and the lower fixed end 2, which are convenient for installing the compression-torsion composite force sensor on the robot screw locking machine. A first annular mounting block 111 is fixed to the bottom of the upper fixed end 1, and a second annular mounting block 211 is fixed to the top of the lower fixed end 2. The four beam torque structures 3 are fixed between the first mounting block 111 and the second mounting block 211. Each beam torque structure 3 includes an elastomer 311 and a first resistance strain sensor 312. Each elastomer 311 is a vertical rectangular block, which can facilitate the twisting of the elastomer 311. The first resistance strain sensor 312 is fixed on the side of each elastomer 311 facing the inside of the upper fixed end 1.

[0029] A protective housing 5 is also fixed between the upper and lower fixed ends 1 and 2. It is sleeved around the outside of the four beam torque structures 3 and fixedly mounted on the outer wall of the second mounting block 211. The height of the protective housing 5 is six-sevenths of the distance from the bottom of the upper fixed end 1 to the top of the lower fixed end 2. A first locking wire nut 313 is fixed to the front of the protective housing 5. A first cable 314 is installed within the first locking wire nut 313. The first cable 314 is electrically connected to the four first resistance strain gauge sensors 312.

[0030] A circular groove is formed at the bottom of the lower fixed end 2, and a plurality of second resistance strain sensors 411 are arranged in an array on the inner top wall of the circular groove. A circular cover plate 212 is fixedly provided at the bottom of the lower fixed end 2, and a second locking wire nut 412 is fixedly provided at the front side of the lower fixed end 2. A second cable 413 is provided within the second locking wire nut 412, and the second cable 413 is electrically connected to the plurality of second resistance strain sensors 411. The inner diameter of the cover plate 212 is nine-tenths of the inner diameter of the circular groove. A circular slot is formed at the bottom of the lower fixed end 2, and the inner diameter of the slot is consistent with the inner diameter of the cover plate 212. The cover plate 212 is fixedly engaged in the slot and is fixed to the interior of the slot by glue. The cover plate 212 can prevent damage to the second resistance strain sensors 411 due to some harsh working conditions.

[0031] The protective shell 5 includes two semi-circular blocks, and the lower end of each semi-circular block is provided with a plurality of circular through-holes in a circumferential array. The side wall array of the second mounting block 211 is provided with a plurality of threaded holes corresponding to the plurality of circular through-holes. Each circular through-hole is provided with a countersunk screw 213, and each countersunk screw 213 is threadedly connected to its corresponding threaded hole, which can facilitate the installation of the protective shell 5.

[0032] The first resistance strain sensor 312 and the second resistance strain sensor 411 are conversion elements. The first resistance strain sensor 312 is tightly fitted to the elastomer 311, and the second resistance strain sensor 411 is tightly fitted to the inner top wall of the annular groove of the lower fixed end 2 by high-temperature curing. When the first resistance strain sensor 312 and the second resistance strain sensor 411 are subjected to external force, deformation occurs internally. The first resistance strain sensor 312 and the second resistance strain sensor 411 then convert the deformation into a change in resistance value, thereby achieving the purpose of measuring the change in force value.

[0033] When the first resistance strain sensor 312 and the elastomer 311, the second resistance strain sensor 411 and the inner top wall of the annular groove of the lower fixed end 2 are cured at high temperature, the temperature of the curing box is adjusted to 165°C for 4.5 hours, so that the glue of the first resistance strain sensor 312 and the second resistance strain sensor 411 is completely squeezed out, and the first resistance strain sensor 312 and the elastomer 311, the second resistance strain sensor 411 and the inner top wall of the annular groove of the lower fixed end 2 are fully fitted.

[0034] In this embodiment, in conjunction with the amplifier circuit, the data transmission rate can reach 1ms, and the first resistance strain sensor 312 and the second resistance strain sensor 411 have high accuracy levels themselves, and can achieve measurement accuracy higher than 1% required by traditional tests.

[0035] Specific implementation process:

[0036] When the robot screw locking machine is working, the contact pressure is transmitted to the lower fixed end 2. At this time, the second resistance strain sensor 411 is deformed, and the measurement result is transmitted to the terminal through the amplifier circuit; when it tightens the screws, the working torque it generates is transmitted to the four elastic bodies 311. At this time, the elastic body 311 and the first resistance strain sensor 312 are deformed, and the measurement result is transmitted to the terminal through the amplifier circuit.

[0037] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A compression-torsion composite force sensor for a robot screw-locking machine, characterized by: It comprises an upper fixed end (1) and a lower fixed end (2), wherein four beam torque structures (3) are arranged in an array along the circumference of the upper fixed end (1) between the upper fixed end (1) and the lower fixed end (2), and a pressure measurement structure (4) is fixedly provided inside the lower fixed end (2); A protective shell (5) is fixedly provided between the upper fixed end (1) and the lower fixed end (2), and the protective shell (5) is sleeved on the outside of the four beam torque structures (3). The height of the protective shell (5) is six sevenths of the distance from the bottom of the upper fixed end (1) to the top of the lower fixed end (2).

2. The compression-torsion composite force sensor for a robot screw-locking machine according to claim 1, characterized in that: The upper fixed end (1) and the lower fixed end (2) are both square blocks; a first annular mounting block (111) is fixedly provided at the bottom of the upper fixed end (1); a second annular mounting block (211) is fixedly provided at the top of the lower fixed end (2); the four beam torque structures (3) are fixedly located between the first mounting block (111) and the second mounting block (211); and the protective shell (5) is fixedly sleeved on the outer wall of the second mounting block (211).

3. The compression-torsion composite force sensor for a robot screw-locking machine according to claim 2, characterized in that: Each beam torque structure (3) comprises an elastic body (311) and a first resistance strain sensor (312); each elastic body (311) is a vertical rectangular block; and the first resistance strain sensor (312) is fixedly provided on one side of each elastic body (311) facing the interior of the upward fixed end (1).

4. The compression-torsion composite force sensor for a robot screw-locking machine according to claim 2, characterized in that: A circular groove is provided at the bottom of the lower fixed end (2), a plurality of second resistance strain sensors (411) are arranged in an array on the inner top wall of the circular groove, and a circular cover plate (212) is fixedly provided at the bottom of the lower fixed end (2).

5. The compression-torsion composite force sensor for a robot screw-locking machine according to claim 3, characterized in that: A first locking wire nut (313) is fixedly provided on the front side of the protective housing (5), a first cable (314) is provided inside the first locking wire nut (313), and the first cable (314) is electrically connected to the four first resistance strain sensors (312).

6. The compression-torsion composite force sensor for a robot screw-locking machine according to claim 4, characterized in that: A second locking wire nut (412) is fixedly provided on the front side of the lower fixed end (2), a second cable (413) is provided inside the second locking wire nut (412), and the second cable (413) is electrically connected to a plurality of second resistance strain sensors (411).

7. The compression-torsion composite force sensor for a robot screw-locking machine according to claim 2, characterized in that: The protective housing (5) comprises two semi-circular ring blocks, the lower end of each semi-circular ring block is provided with a plurality of circular through holes in a circumferential array, the side wall array of the second mounting block (211) is provided with a plurality of threaded holes corresponding to the plurality of circular through holes, each of the circular through holes is provided with a countersunk screw (213), and each of the countersunk screws (213) is threadedly connected to its corresponding threaded hole.

8. The compression-torsion composite force sensor for a robot screw-locking machine according to claim 4, characterized in that: The inner diameter of the cover plate (212) is nine-tenths of the inner diameter of the annular groove; a circular-shaped slot is provided at the bottom of the lower fixed end (2); the inner diameter of the slot is consistent with the inner diameter of the cover plate (212); and the cover plate (212) is fixedly engaged in the slot.

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