CN220783942U

CN220783942U - Force sensor

Info

Publication number: CN220783942U
Application number: CN202321749567.XU
Authority: CN
Inventors: 申鹏林; 朱路生; 谷菲
Original assignee: Chengdu Kanop Robot Technology Co ltd
Current assignee: Chengdu Kanop Robot Technology Co ltd
Priority date: 2023-07-05
Filing date: 2023-07-05
Publication date: 2024-04-16
Anticipated expiration: 2033-07-05

Abstract

The application relates to a force sensor, comprising: the magnetic force sensing device comprises a force sensing elastic body, a split type magnetic encoder code disc, a split type magnetic encoder code head, a harmonic speed reducer and a torque motor, wherein the torque motor is connected with the harmonic speed reducer, the harmonic speed reducer is connected with the force sensing elastic body, the split type magnetic encoder code disc is arranged on the force sensing elastic body, and the split type magnetic encoder code disc is adhered to the force sensing elastic body and is opposite to the split type magnetic encoder code head. The force sensor that this application provided can solve the force sensor among the prior art because of the material is thinner after using a period, and intensity is insufficient, constantly produces deformation, and force sensor's measurement accuracy can constantly change, in the use of later stage, the problem of need constantly calibrating.

Description

Force sensor

Technical Field

The present application relates to the field of force sensors, and more particularly to a force sensor.

Background

The cooperative robot has the characteristics of light weight, friendliness, strong perceptibility, good man-machine cooperation, convenience in programming and the like. For the light weight treatment of the cooperative robot, the current mainstream scheme adopts aluminum alloy or carbon fiber materials, and weight is reduced by means of integrated design, scheme optimization and the like, so that the light weight is realized. Aiming at the requirement of sensing capability, the external force value is measured in the mode of measuring an elastomer through current feedback or integrating a torque sensor and a strain gauge in the market; for the design scheme of the collaborative robot encoder, the current main stream technical scheme is to adopt a single-circle absolute encoder with a battery or two single-circle absolute encoders, wherein one end of each single-circle absolute encoder is fixed on a motor rotor, and the other end of each single-circle absolute encoder is fixed on a harmonic reducer end. Meanwhile, the joint band brake of the cooperative robot generally adopts a bolt type or friction plate type braking scheme to brake the joint; and each joint of the cooperative robot is combined by a high-speed ratio harmonic reducer and a moment frameless motor, so that high torque performance is generated.

However, there are some disadvantages to the above-described cooperative robot joints:

1) When the torque is estimated through the current due to the relation of friction force, the dynamic parameters cannot be effectively estimated, so that the torque estimation lacks high-precision performance, particularly the small torque range estimation, and the fluctuation range of the estimation through the motor current is large, and the accuracy is lacking. The torque is measured by adopting a mode of sticking a strain gauge, so that the torque measurement precision is often changed after the service time is long because the structural strain part is fragile and the service life of the force sensor is not long.

2) The joint weight of the cooperative robot is relatively large, and the design of the joint is required to follow the light safety design rule, so that the integration level of the cooperative robot is very high.

3) The adoption of two single-turn absolute encoders has certain difficulties for the design of structure and light weight, in particular for the assembly and the layout of the related cables, which have great influence on the cost and the production.

Disclosure of Invention

To solve the above technical problems or at least partially solve the above technical problems, the present application provides a force sensor.

In a first aspect, the present application provides a force sensor comprising: the magnetic force sensing device comprises a force sensing elastic body, a split type magnetic encoder code disc, a split type magnetic encoder code head, a harmonic speed reducer and a torque motor, wherein the torque motor is connected with the harmonic speed reducer, the harmonic speed reducer is connected with the force sensing elastic body, the split type magnetic encoder code disc is arranged on the force sensing elastic body, and the split type magnetic encoder code disc is adhered to the force sensing elastic body and is opposite to the split type magnetic encoder code head.

Preferably, the method further comprises: the speed reducer fixing shell is fixed in the speed reducer fixing shell.

Preferably, the method further comprises: the device comprises a crossed roller bearing inner ring baffle ring and a crossed roller bearing outer ring baffle ring, wherein the crossed roller bearing outer ring baffle ring is connected with a reducer fixing shell, the crossed roller bearing inner ring baffle ring is connected with a force sensing elastic body, and the crossed roller bearing inner ring baffle ring is sleeved with the crossed roller bearing inner ring baffle ring.

Preferably, the method further comprises: the torque motor shell is connected with the speed reducer fixed shell, and the torque motor is arranged inside the torque motor shell.

Preferably, the method further comprises: the torque motor comprises a first deep groove ball bearing and a motor input shaft, wherein the motor input shaft is connected with an inner ring of the first deep groove ball bearing in a matched mode, a torque motor shell is connected with an outer ring of the first deep groove ball bearing in a matched mode, and the motor input shaft is connected with a harmonic speed reducer.

Preferably, the method further comprises: the brake fixing shell is connected with the torque motor shell, the power-off brake is arranged inside the brake fixing shell, the inner ring of the second deep groove ball bearing is connected with the brake fixing shell in a matched mode, and the outer ring of the second deep groove ball bearing is connected with the encoder moving disc flange in a matched mode.

Preferably, the method further comprises: the low-voltage servo motor comprises an encoder moving disc, an encoder static disc, a low-voltage servo driver, a cable fixing metal plate and a motor input shaft, wherein the encoder moving disc is connected with an encoder moving disc flange, the encoder moving disc flange is connected with the motor input shaft, the encoder static disc and the low-voltage servo driver are connected with a brake fixing shell, and the cable fixing metal plate is connected with the low-voltage servo driver.

Preferably, the method further comprises: and the stainless steel stud is connected with the low-voltage servo driver and the cable fixing sheet metal.

Preferably, the method further comprises: the novel motor comprises a third deep groove ball bearing, a bearing pressing disc and a wire passing cylinder, wherein an inner ring of the third deep groove ball bearing is connected with the wire passing cylinder in a matched mode, an outer ring of the third deep groove ball bearing is connected with a motor input shaft in a matched mode, an inner ring of the second deep groove ball bearing is connected with the bearing pressing disc in a matched mode, and the bearing pressing disc is connected with an encoder moving disc flange.

Preferably, the method further comprises: the device comprises a first crossed roller bearing and a second crossed roller bearing, wherein an inner ring of the first crossed roller bearing is connected with a force sensing elastic body in a matched mode, an outer ring of the first crossed roller bearing is connected with a speed reducer fixing shell in a matched mode, an inner ring of the second crossed roller bearing is connected with the force sensing elastic body in a matched mode and is fixed on the force sensing elastic body through an inner ring baffle ring of the crossed roller bearing, and an outer ring of the second crossed roller bearing is connected with the speed reducer fixing shell in a matched mode and is fixed on the speed reducer fixing shell through an outer ring baffle ring of the crossed roller bearing.

Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:

the force sensor that this application provided can solve the force sensor among the prior art because of the material is thinner after using a period, and intensity is insufficient, constantly produces deformation, and force sensor's measurement accuracy can constantly change, in the use of later stage, the problem of need constantly calibrating.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the utility model and together with the description, serve to explain the principles of the utility model.

In order to more clearly illustrate the embodiments of the utility model or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, and it will be obvious to a person skilled in the art that other drawings can be obtained from these drawings without inventive effort.

FIG. 1 is a schematic diagram of a force sensor provided in an embodiment of the present application;

FIG. 2 is a schematic cross-sectional view of a force sensor provided in an embodiment of the present application;

FIG. 3 is a schematic diagram of a force sensor provided in an embodiment of the present application;

FIG. 4 is a schematic diagram of a force sensor provided in an embodiment of the present application;

fig. 5 is a schematic diagram of a force sensor according to an embodiment of the present application.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present application based on the embodiments herein.

Fig. 1 is a schematic diagram of a force sensor according to an embodiment of the present application.

The inner ring baffle ring 1 of the crossed roller bearing is fixed on the force sensing elastic body 3 through screws, the outer ring baffle ring 2 of the crossed roller bearing is fixed on the fixed shell 6 of the speed reducer through screws, and the code wheel 4 of the split type magnetic encoder is adhered on the force sensing elastic body 3 through glue. The split magnetic encoder reading head 5 is fixed on the force sensing elastomer 3 through a screw, the harmonic speed reducer 7 is fixed on the speed reducer fixing housing 6, the force sensing elastomer 3 is matched with the inner ring of the first crossed roller bearing 23, the speed reducer fixing housing 6 is matched with the outer ring of the first crossed roller bearing 23, and the force sensing elastomer 3 rotates through the force transmitted by the harmonic speed reducer 7.

The torque motor housing 8 is fixed to the speed reducer fixing case 6, and the torque motor 10 is bonded to the torque motor housing 8. The motor input shaft 22 is fitted with the inner race of the first deep groove ball bearing 9, and the torque motor housing 8 is fitted with the outer race of the first deep groove ball bearing 9. The motor input shaft 22 is connected by screws to the wave generator of the harmonic reducer 7. The brake fixing case 11 is fixed to the torque motor case 8 by screws, and the power-off brake 21 is fixed to the brake fixing case 11. The inner ring and the outer ring of the second deep groove ball bearing 12 are respectively matched with the brake fixing shell 11 and the encoder moving disc flange 13.

The encoder movable disc 14 is fixed on the encoder movable disc flange 13, the encoder movable disc flange 13 is connected with the motor input shaft 22 through screws, the encoder static disc 15 is fixed on the brake fixing shell 11, the low-pressure servo driver 16 is fixed on the brake fixing shell 11 through a stainless steel stud 18, and the cable fixing sheet metal 17 is fixed on the low-pressure servo driver 16 through the stainless steel stud 18. The inner ring of the third deep groove ball bearing 19 is matched with the wire passing cylinder 25, and the outer ring is matched with the motor input shaft 22. The bearing pressing plate 20 is matched with the inner ring of the second deep groove ball bearing 12 and is fixed on the encoder moving plate flange 13 through screws.

The power-off brake 21 is fixed on the brake fixing shell 11, and is matched with the motor input shaft 22 to achieve a braking effect. The inner ring of the first crossed roller bearing 23 is matched with the force sensing elastic body 3, and the outer ring is matched with the speed reducer fixing shell 6 to play a role in supporting the force sensing elastic body 3. The inner ring of the second cross roller bearing 24 is matched with the force sensing elastic body 3, and is fixed on the force sensing elastic body 3 through the inner ring baffle ring 1 of the cross roller bearing, the outer ring is matched with the fixed shell 6 of the speed reducer, and is fixed on the fixed shell 6 of the speed reducer through the outer ring baffle ring 2 of the cross roller bearing.

The innovation point of the application is that the force sensor is innovatively designed, and all force sensors on the market adopt a mode of sticking strain gauges to measure torque and are used for a cooperative robot. However, the strain gauge needs to be attached with a thin enough material to be able to detect the deformation of the material by the strain gauge, thereby measuring the torque of the joint. This can create a problem in that after a period of use, the force sensor is deformed constantly due to the thin material, insufficient strength, and the measurement accuracy of the force sensor is changed constantly, and in a later use, calibration is required constantly. Ultimately resulting in damage to the force sensing due to plastic deformation of the material. In response to this problem, the present application provides a force sensor that fundamentally solves this problem.

One end of the force sensing elastic body 3 is fixed at the output end of the harmonic speed reducer 7, torque is generated through the torque motor 10, and amplified torque is output through the harmonic speed reducer 7. The split type magnetic encoder code wheel 4 is stuck on the force sensing elastomer 3, and 4 split type magnetic encoder read heads 5 are uniformly distributed and fixed on the force sensing elastomer 3, a shaft is arranged between the split type magnetic encoder code wheel 4 fixed by the force sensing elastomer 3 and the split type magnetic encoder read heads 5, a certain load is fixed at the left end of the force sensing elastomer 3, and when the torque motor 10 rotates, the split type magnetic encoder code wheel 4 and the split type magnetic encoder read heads 5 can have an error of middle torque due to the load and the output end of the harmonic reducer 7, and then the split type magnetic encoder read heads 5 can read out a certain difference. The force sensing elastomer 3 stiffness is calibrated earlier by comparing the team with 4 sets of encoder correspondence data. The bit value of the encoder is determined. The torque value generated by the harmonic speed reducer 7 can be calculated in real time through a certain conversion. Wherein the first and the second crossed roller bearings 23, 24 are designed to prevent the elastic body from being influenced by bending moment, thereby influencing the measurement of the torque value of the harmonic reducer 7 by the force sensing.

It should be noted that in this document, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

The foregoing is only a specific embodiment of the utility model to enable those skilled in the art to understand or practice the utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the utility model. Thus, the present utility model is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A force sensor, comprising: force sensing elastomer (3), split type magnetic encoder code wheel (4), split type magnetic encoder code wheel (5), harmonic speed reducer (7) and moment motor (10), wherein, moment motor (10) with harmonic speed reducer (7) are connected, harmonic speed reducer (7) with force sensing elastomer (3) are connected, split type magnetic encoder code wheel (5) arrange in on force sensing elastomer (3), split type magnetic encoder code wheel (4) paste in on force sensing elastomer (3), and with split type magnetic encoder code wheel (5) are relative.

2. The force sensor of claim 1, further comprising: and the harmonic speed reducer (7) is fixed in the speed reducer fixing shell (6).

3. The force sensor of claim 2, further comprising: the device comprises a crossed roller bearing inner ring baffle ring (1) and a crossed roller bearing outer ring baffle ring (2), wherein the crossed roller bearing outer ring baffle ring is connected with a speed reducer fixing shell (6), the crossed roller bearing inner ring baffle ring (1) is connected with a force sensing elastic body (3), and the crossed roller bearing inner ring baffle ring (1) is sleeved on the crossed roller bearing outer ring baffle ring (2).

4. The force sensor of claim 2, further comprising: the torque motor shell (8), torque motor shell (8) with speed reducer fixed shell (6) are connected, torque motor (10) set up in torque motor shell (8) are inside.

5. The force sensor of claim 4, further comprising: the motor comprises a first deep groove ball bearing (9) and a motor input shaft (22), wherein the motor input shaft (22) is connected with an inner ring of the first deep groove ball bearing (9) in a matched mode, a torque motor shell (8) is connected with an outer ring of the first deep groove ball bearing (9) in a matched mode, and the motor input shaft (22) is connected with the harmonic reducer (7).

6. The force sensor of claim 4, further comprising: the brake fixing device comprises a brake fixing shell (11), a second deep groove ball bearing (12), an encoder moving disc flange (13) and a power-losing brake (21), wherein the brake fixing shell (11) is connected with a torque motor shell (8), the power-losing brake (21) is arranged inside the brake fixing shell (11), an inner ring of the second deep groove ball bearing (12) is connected with the brake fixing shell (11) in a matched mode, and an outer ring of the second deep groove ball bearing (12) is connected with the encoder moving disc flange (13) in a matched mode.

7. The force sensor of claim 6, further comprising: encoder movable disc (14), encoder quiet dish (15), low pressure servo driver (16), cable fixed panel beating (17) and motor input shaft (22), wherein, encoder movable disc (14) with encoder movable disc flange (13) are connected, encoder movable disc flange (13) with motor input shaft (22) are connected, encoder quiet dish (15) with low pressure servo driver (16) with stopper fixed shell (11) are connected, cable fixed panel beating (17) with low pressure servo driver (16) are connected.

8. The force sensor of claim 7, further comprising: and the stainless steel stud (18), wherein the stainless steel stud (18) is connected with the low-voltage servo driver (16) and the cable fixing sheet metal (17).

9. The force sensor of claim 7, further comprising: the novel encoder comprises a third deep groove ball bearing (19), a bearing pressing disc (20) and a wire passing cylinder (25), wherein an inner ring of the third deep groove ball bearing (19) is connected with the wire passing cylinder (25) in a matched mode, an outer ring of the third deep groove ball bearing (19) is connected with a motor input shaft (22) in a matched mode, an inner ring of the second deep groove ball bearing (12) is connected with the bearing pressing disc (20) in a matched mode, and the bearing pressing disc (20) is connected with an encoder moving disc flange (13).

10. The force sensor of claim 3, further comprising: the device comprises a first crossed roller bearing (23) and a second crossed roller bearing (24), wherein an inner ring of the first crossed roller bearing (23) is connected with a force sensing elastic body (3) in a matched mode, an outer ring of the first crossed roller bearing (23) is connected with a speed reducer fixing shell (6) in a matched mode, an inner ring of the second crossed roller bearing (24) is connected with the force sensing elastic body (3) in a matched mode, the inner ring of the second crossed roller bearing is fixed on the force sensing elastic body (3) through a crossed roller bearing inner ring baffle ring (1), and an outer ring of the second crossed roller bearing (24) is connected with the speed reducer fixing shell (6) in a matched mode and is fixed on the speed reducer fixing shell (6) through a crossed roller bearing outer ring baffle ring (2).