A force control sensor for a linear rotary actuator

Abstract

The utility model discloses a kind of force control sensors for linear rotary actuators, it is related to force control sensor technical field, including elastomer, elastomer has first deformation direction and second deformation direction, elastomer is equipped with first anti-overload structure and second anti-overload structure, first anti-overload structure is limited to elastomer along first deformation direction, second anti-overload structure is limited to elastomer along second deformation direction, elastomer can be prevented by second anti-overload structure upwards deformation, avoid elastomer and lead to the damage of sensor because of excessive upwards deformation, and, first anti-overload structure can avoid elastomer excessive downwards deformation, improve the overload resistance of elastomer.

Description

Technical Field

[0001] This utility model relates to the field of force control sensor technology, and in particular to a force control sensor for linear rotary actuators. Background Technology

[0002] With the deep penetration of automation technology into fields such as 3C product manufacturing, automotive electronic module integration, precision scientific research and testing, and medical device research and development, linear rotary actuators, with their combined functions of rotary tightening, linear pressing, precise clamping, and positioning, have become core execution components for achieving efficient and precise processes. The operating accuracy and reliability of such actuators are highly dependent on the performance of the matching force control sensors. In scenarios such as chip pin pressing, micro-metal part gripping, and laparoscopic instrument tissue clamping, sensors are required not only to accurately monitor micro-force values ​​of 50-350g, but also to cope with complex working conditions such as actuator lifting and collisions to avoid workpiece damage, equipment failure, and production capacity loss.

[0003] Currently, sensors used to monitor actuator force values ​​are generally a combination of strain gauge force sensors and unidirectional overload protection structures. The core component uses ordinary aluminum alloy as the elastomer substrate, with strain gauges attached to the surface of the elastomer to sense the push and pull force signals of the actuator. The force signals are processed by a simple analog amplification circuit and then output to the controller to realize an overload alarm function based on a fixed threshold. In terms of overload protection, a single-sided metal anti-overload frame is set below the elastomer. When the actuator grabs material that is too heavy, causing the pull force to exceed 600g, the elastomer deforms downward until it contacts the anti-overload frame, and the rigid metal contact blocks part of the overload force from being transmitted to the strain gauges.

[0004] However, in reverse conditions such as the actuator colliding with the equipment above or the workpiece being pushed up, no protective structure is set up. This will cause the linear rotary actuator to collide due to lifting and positioning errors, or the workpiece to jam and generate upward force. The elastic body has no rigid support and is prone to permanent damage due to excessive deformation. The current solution cannot block the transmission of overload force in time, which will not only cause the sensor to be scrapped, but may also cause the actuator output shaft to break and the motor to burn out, resulting in a significant increase in the downtime and maintenance time of the production line.

[0005] To address the above shortcomings, further improvements are needed to the sensor to mitigate the permanent deformation caused by the lack of an upper protective structure. Utility Model Content

[0006] This invention aims to overcome the problem of permanent deformation of sensors due to the lack of an upper protective structure, and provides a force control sensor for linear rotary actuators.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a force control sensor for a linear rotary actuator, comprising an elastic body having a first deformation direction and a second deformation direction, the elastic body being provided with a first overload protection structure and a second overload protection structure, the first overload protection structure defining the elastic body along the first deformation direction, and the second overload protection structure defining the elastic body along the second deformation direction.

[0008] As a further embodiment of this utility model: the first overload protection structure includes a limiting block, which is detachably installed on the lower side of the elastic body.

[0009] As a further embodiment of this utility model: the second overload protection structure includes a boss, the boss being located on the upper side of the elastomer, and the boss and the elastomer being integrally formed.

[0010] As a further embodiment of this utility model: the first overload protection structure includes two limiting blocks, one of which is located above the elastic body and the other of which is located below the elastic body; the second overload protection structure includes two bosses, one of which is located on the upper surface of the elastic body and the other of which is located on the lower surface of the elastic body.

[0011] As a further embodiment of this utility model: the protrusion is located at a portion of the end face of the elastic body, the remaining portion of the end face of the elastic body is the abutting surface, the limiting block is provided with an abutting block on the side near the elastic body, and the abutting block is in contact with the abutting surface on the end face near the elastic body.

[0012] As a further embodiment of this utility model: the elastic body includes a first elastic body and a second elastic body, and two deformation bodies are provided between the first elastic body and the second elastic body, and each of the two deformation bodies is symmetrically provided with two strain gauges.

[0013] As a further embodiment of this utility model: the deformable body is integrally formed with the first elastic body and the second elastic body, and a deformation groove is formed on the deformable body. One of the two strain gauges is located on one side of the inner wall of the deformation groove, and the other strain gauge is located on the other side of the inner wall of the deformation groove.

[0014] As a further embodiment of this utility model: a limiting structure is provided between the first elastic body and the second elastic body. The limiting structure includes a connecting block provided on one side of the first elastic body and a positioning block provided on one side of the second elastic body. The positioning block has a limiting groove for the connecting block to enter.

[0015] As a further embodiment of this utility model: the connecting block has a connecting part protruding on the side near the positioning block, the connecting part is in the shape of a "T", and the shape of the limiting groove is adapted to the connecting part.

[0016] As a further embodiment of this utility model: a movable gap is provided between the outer wall of the connecting part and the inner wall of the limiting groove, and the movable gap distance is 0.07-0.13mm.

[0017] Compared with the prior art, the beneficial effects of this technical solution are as follows: the second anti-overload structure can prevent the elastomer from deforming upward, avoiding damage to the sensor caused by excessive upward deformation of the elastomer; and the first anti-overload structure can prevent the elastomer from deforming excessively downward, improving the elastomer's overload resistance.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1.

[0021] Figure 2 This is a structural schematic diagram of Embodiment 2. Figure 1 ;

[0022] Figure 3 This is a structural schematic diagram of Embodiment 2. Figure 2 ;

[0023] Figure 4 This is a schematic diagram illustrating the disassembly effect of the limiting block in Embodiment 2.

[0024] Figure 5 This is a bottom view of the structure of Embodiment 2;

[0025] Figure 6 yes Figure 5 Schematic diagram of the cross section at point AA. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] Example 1

[0028] This embodiment discloses a force control sensor for a linear rotary actuator. Please refer to [link / reference]. Figure 1 A force control sensor for a linear rotary actuator includes an elastic body 1. The elastic body 1 has a first deformation direction and a second deformation direction. The elastic body 1 is provided with a first overload protection structure 2 and a second overload protection structure 3. The first overload protection structure 2 limits the elastic body 1 along the first deformation direction, and the second overload protection structure 3 limits the elastic body 1 along the second deformation direction. The second overload protection structure can prevent the elastic body from deforming upward, avoiding damage to the sensor caused by excessive upward deformation of the elastic body. Furthermore, the first overload protection structure can prevent the elastic body from deforming excessively downward, improving the overload resistance of the elastic body.

[0029] As a further embodiment of this utility model: the first overload protection structure 2 includes a limiting block 21, which is detachably installed on the lower side of the elastic body 1. The limiting block 21 is made of 45# steel and is detachably installed on the lower end face of the elastic body 1 by two M2 hexagon socket bolts. An initial gap of 0.1mm is reserved between the upper surface of the limiting block 21 and the lower surface of the elastic body 1. This gap can prevent the elastic body from making ineffective contact with the limiting block 21 during normal force control, and at the same time ensure that the protection is triggered quickly during overload.

[0030] As a further embodiment of this utility model: the second overload protection structure 3 includes a boss 31, which is located on the upper side of the elastic body 1. The boss 31 and the elastic body 1 are integrally formed. The boss 31 and the upper end face of the elastic body 1 are integrally formed and are evenly distributed at the four corners of the upper end face of the elastic body. The height of the boss 31 is 2.5mm. Its top end is reserved with an initial gap of 0.1mm from the lower surface of the output shaft flange of the linear rotary actuator. The gap accuracy is consistent with that of the first overload protection structure.

[0031] The specific overload prevention process is as follows:

[0032] When the linear rotary actuator generates a downward overload during operation, the elastic body 1 bends downward along the first deformation direction. As the deformation increases, the lower surface of the elastic body gradually approaches the limiting block 21. When the force reaches 750g, the lower surface of the elastic body is in complete contact with the upper surface of the limiting block 21. The limiting block blocks the overload force from being transmitted to the strain gauge inside the elastic body through rigid support, thus preventing the strain gauge from being overstretched and damaged.

[0033] When the linear rotary actuator generates an upward overload during operation, the elastic body 1 bends and deforms upward along the second deformation direction, and the top of the boss 31 contacts the lower surface of the actuator flange before the main body of the elastic body; when the force reaches 750g, the boss 31 completely offsets the upward overload force through the rigid support of the flange, preventing the elastic body from being bent and causing permanent deformation.

[0034] As a further embodiment of this utility model: the elastic body 1 includes a first elastic body 12 and a second elastic body 13. Two deformation bodies 14 are provided between the first elastic body 12 and the second elastic body 13. Each deformation body 14 is symmetrically provided with two strain gauges. When the first elastic body 12 and the second elastic body 13 start to move, they will drive the deformation body 14 to move at the end connected to it, thereby causing the deformation body 14 to deform as a whole. The deformation of the deformation body 14 will cause the resistance of the strain gauges to change, thereby achieving the effect of monitoring the force value.

[0035] As a further embodiment of this utility model: the deformable body 14 is integrally formed with the first elastic body 12 and the second elastic body 13. A deformation groove 141 is provided on the deformable body 14. One of the two strain gauges is located on one side of the inner wall of the deformation groove 141, and the other strain gauge is located on the other side of the inner wall of the deformation groove 14. The two deformable bodies have a total of 8 strain gauges to form a full-bridge measurement circuit. The surface of the strain gauges is coated with a 0.5mm thick epoxy resin protective layer to prevent resistance drift caused by dust and water vapor erosion.

[0036] As a further embodiment of this utility model: a limiting structure 15 is provided between the first elastic body 12 and the second elastic body 13. The limiting structure 15 includes a connecting block 151 on one side of the first elastic body 12 and a positioning block 152 on one side of the second elastic body 13. The positioning block 152 has a limiting groove 153 for the connecting block 151 to enter. When one of the first elastic body 12 and the second elastic body 13 moves, the outer wall of the positioning block will contact the inner wall of the limiting groove. When the outer wall of the positioning block contacts the inner wall of the limiting groove, a rigid contact will be formed, which can prevent the first elastic body or the second elastic body from continuing to move. This can prevent the first elastic body and the second elastic body from moving under excessive load and avoid permanent deformation of the entire elastic body 1.

[0037] As a further embodiment of this utility model: a connecting part 154 protrudes from the side of the connecting block 151 near the positioning block 152. The connecting part 154 is T-shaped. The shape of the limiting groove 153 is adapted to the connecting part 154. There is a movable gap between the outer wall of the connecting part 154 and the inner wall of the limiting groove 153. The movable gap distance is 0.07-0.13mm, preferably 0.1mm. The movable gap can ensure that the connecting part can move, allowing the deformable part to deform without invalid contact. The T-shaped connecting part can ensure that the connecting part can contact the inner wall of the limiting groove when moving along the first deformation direction and the second deformation direction, thereby ensuring the limiting effect between the connecting part and the limiting groove.

[0038] Example 2

[0039] The difference between this embodiment and Embodiment 1 is that the first overload protection structure 2 includes two limiting blocks 21, one of which is located above the elastic body 1 and the other limiting block 21 is located below the elastic body 1. The second overload protection structure 3 includes two bosses 31, one of which is located on the upper surface of the elastic body 1 and the other boss 31 is located on the lower surface of the elastic body 1. Both limiting blocks 21 are installed on the elastic body 1 by M2 bolts.

[0040] When the linear rotary actuator experiences a downward pull-overload during operation, the elastomer 1 bends downward along the first deformation direction. As the deformation increases, the lower surface of the elastomer gradually approaches the limiting block 21. When the force reaches 750g, the lower surface of the elastomer is in complete contact with the upper surface of the limiting block 21. The limiting block, through rigid support, blocks the transmission of overload force to the strain gauge inside the elastomer, preventing the strain gauge from being overstretched and damaged. At the same time, the boss can increase the thickness of the bottom of the elastomer, thereby improving the elastomer's overload resistance.

[0041] When the linear rotary actuator experiences an upward overload during operation, the elastomer 1 bends upward along the second deformation direction. The top of the boss 31 contacts the lower surface of the actuator flange before the main body of the elastomer. When the force reaches 750g, the boss 31 offsets the upward overload force through the rigid support of the flange. Furthermore, the upper surface of the elastomer contacts the lower surface of the limiting block 21, so that the limiting block blocks the transmission of the overload force to the strain gauge inside the elastomer through rigid support, thereby preventing the strain gauge from being overstretched and damaged, and preventing the elastomer from being bent and causing permanent deformation.

[0042] As a further embodiment of this utility model: the protrusion 31 is located at a portion of the end face of the elastic body 1, and the remaining portion of the end face of the elastic body 1 is the abutment surface 11. The limiting block 21 is provided with an abutment block 22 on the side near the elastic body 1. The abutment block 22 is in contact with the abutment surface 11 near the end face of the elastic body 1, which is used to enhance the coaxiality of the assembly between the limiting block and the elastic body and avoid the protection failure caused by the displacement of the limiting block.

[0043] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A force control sensor for a linear rotary actuator, characterized in that, The system includes an elastomer (1) having a first deformation direction and a second deformation direction. The elastomer (1) is provided with a first overload protection structure (2) and a second overload protection structure (3). The first overload protection structure (2) limits the elastomer (1) along the first deformation direction, and the second overload protection structure (3) limits the elastomer (1) along the second deformation direction.

2. The force control sensor for a linear rotary actuator according to claim 1, characterized in that, The first overload protection structure (2) includes a limiting block (21), which is detachably installed on the lower side of the elastomer (1).

3. The force control sensor for a linear rotary actuator according to claim 2, characterized in that, The second overload protection structure (3) includes a boss (31), which is located on the upper side of the elastomer (1) and is integrally formed with the elastomer (1).

4. The force control sensor for a linear rotary actuator according to claim 1, characterized in that, The first overload protection structure (2) includes two limiting blocks (21), one of which is located above the elastic body (1) and the other limiting block (21) is located below the elastic body (1). The second overload protection structure (3) includes two bosses (31), one of which is located on the upper surface of the elastic body (1) and the other boss (31) is located on the lower surface of the elastic body (1).

5. The force control sensor for a linear rotary actuator according to claim 4, characterized in that, The boss (31) is located at a part of the end face of the elastic body (1), and the remaining part of the end face of the elastic body (1) is the abutment surface (11). The limiting block (21) is provided with an abutment block (22) on the side near the elastic body (1). The abutment block (22) is in contact with the abutment surface (11) on the end face near the elastic body (1).

6. The force control sensor for a linear rotary actuator according to claim 1, characterized in that, The elastic body (1) includes a first elastic body (12) and a second elastic body (13), and two deformation bodies (14) are provided between the first elastic body (12) and the second elastic body (13), and each of the two deformation bodies (14) is symmetrically provided with two strain gauges.

7. The force control sensor for a linear rotary actuator according to claim 6, characterized in that, The deformable body (14) is integrally formed with the first elastic body (12) and the second elastic body (13). A deformation groove (141) is provided on the deformable body (14). One of the two strain gauges is located on one side of the inner wall of the deformation groove (141), and the other strain gauge is located on the other side of the inner wall of the deformation groove (141).

8. The force control sensor for a linear rotary actuator according to claim 6, characterized in that, A limiting structure (15) is provided between the first elastic body (12) and the second elastic body (13). The limiting structure (15) includes a connecting block (151) on one side of the first elastic body (12) and a positioning block (152) on one side of the second elastic body (13). The positioning block (152) has a limiting groove (153) for the connecting block (151) to enter.

9. The force control sensor for a linear rotary actuator according to claim 8, characterized in that, The connecting block (151) has a connecting part (154) protruding on one side near the positioning block (152). The connecting part (154) is T-shaped, and the shape of the limiting groove (153) is adapted to the connecting part (154).

10. The force control sensor for a linear rotary actuator according to claim 9, characterized in that, A movable gap is provided between the outer wall of the connecting part (154) and the inner wall of the limiting groove (153), and the movable gap distance is 0.07-0.13mm.

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