CN209551773U - A robot joint variable stiffness module based on cam lever structure - Google Patents

Abstract

The joint of robot variation rigidity module based on cam-type lever construction that the utility model discloses a kind of, including importation, output par, c and stiffness tuning part.Stiffness tuning part includes pressure spring, cam-type lever and stiffness tuning fulcrum；Cam-type lever is rotated around stiffness tuning fulcrum, and one end and output par, c cooperation, the other end and pressure spring cooperate.Bearing is equipped between importation and output par, c to bear the non-torque load of entire module and make importation and output par, c can be with relative rotation.When the output par, c of variation rigidity module is by external transient load, load is absorbed by cam-type lever transmission to pressure spring, to reduce external impact, realize flexible drive output, while improving the robustness and operation stability of robot.This programme is compact-sized, at low cost and be integrated into a module, therefore conveniently applies in various interactive devices, especially in flexible machine person joint.This programme also has the advantages that easy to operate, easy implement.

Description

A robot joint variable stiffness module based on cam lever structure

technical field

The utility model relates to the field of robots, in particular to a robot joint variable stiffness module based on a cam-type lever structure.

Background technique

With the rapid development of modern industrial technology, the scope of application of robots has expanded dramatically, and human-machine collaboration has become increasingly close. With the continuous deepening of human-computer interaction, the working environment of the robot has become complex and has great uncertainty. It may collide with objects and people in the surrounding environment at any time, which poses a high challenge to the safety of the robot. Require. For example, the robot needs to dynamically adjust the joint stiffness and the active/passive flexibility of the robot joint according to the changes of the external environment and its own load. Therefore, it has become a technical difficulty in the field of collaborative robots to add a high-performance, compact variable stiffness mechanism to the joints of the collaborative robot to make the robot flexible. Therefore, there is an urgent need for a batch of superior variable stiffness modules to promote the continuous development of collaborative robots.

At the same time, the robot industry is developing rapidly, with large demand and long design cycle. Therefore, the modular design idea is more and more adopted in the field of robotics. By decomposing the common functions of the robot from the mechanism and control, multiple functional modules with independent functions are formed. Through reconstruction, the robot structure required for the application is composed. type. Thus, to a certain extent, the application cost of robots can be reduced, the speed of research and development can be accelerated, and the risk of research and development can be reduced.

In terms of variable stiffness, researchers at home and abroad have developed many variable stiffness mechanisms based on different principles. However, the existing variable stiffness design more or less has some shortcomings, such as large volume and weight, or low versatility, or small stiffness adjustment range. In this way, it is difficult to apply to robot joints with compact structure, light weight as possible, and large stiffness adjustment range.

Today's existing technology uses two pairs of compression springs and a cam structure to achieve variable stiffness. The cam passively changes the spring compression and the motor actively changes the spring compression to change the stiffness. However, there is no stiffness amplification structure, resulting in a small stiffness adjustment range, and the use of two pairs of compression springs also makes the volume of the variable stiffness rotating flexible joint larger.

Therefore, the prior art needs to be further improved and perfected.

Utility model content

The purpose of this utility model is to overcome the deficiencies of the prior art, and provide a robot joint variable robot based on a cam-type lever structure that can reduce the external impact of the robot joint, realize flexible drive output, and improve the robustness and operation stability of the robot. Stiffness module.

The purpose of this utility model is achieved through the following technical solutions:

A robot joint variable stiffness module based on a cam-type lever structure, the variable stiffness module mainly includes an input part, an output part, and a stiffness adjustment part. The output section is disposed within the input section. A bearing is provided between the input part and the output part to bear the non-torque load of the whole module and make the input part and the output part relatively rotatable.

Specifically, the input part includes a casing and a bearing ring of the casing. The housing bearing retaining ring is arranged on the housing and is fixedly connected with the housing. The housing is provided with guide grooves for constraining compression springs and constraining rigidity adjustment fulcrums. The guide groove is located at the bottom of the shell; the shell is provided with necessary installation holes and lightening structures.

Specifically, the output part includes an output disk and an output disk bearing retaining ring. The output disk is arranged in the output disk bearing retaining ring and concentrically arranged with the output disk bearing retaining ring. The bearing is arranged in the casing, its outer ring is fixedly connected with the casing bearing retaining ring, and its inner ring is connected with the output disk bearing retaining ring.

Specifically, the stiffness adjustment part includes a compression spring, a cam lever, a needle roller, a compression spring support, a compression spring mounting seat, a shaft sleeve, and a stiffness adjustment fulcrum. The rigidity adjustment fulcrum is fixed on the cam type lever. The cam-type lever is set in the shell and can rotate around the rigidity adjustment fulcrum, one end of which is connected with the output disk through the bushing, so that the output disk rotates with the cam-type lever when rotating, and the other end contacts the compression spring through the needle . The needle roller is installed in the pressure spring support, and its bottom is clamped in the guide groove, and can move linearly in the guide groove. The mounting base of the compression spring is fixed in the shell, one end of the compression spring is fixed on the mounting base of the compression spring, and the other end abuts against the mounting base of the compression spring, forcing the needle roller to bear against the cam lever. The compression spring and the needle roller are arranged in pairs on both sides of the cam-type lever and arranged symmetrically.

Furthermore, in order to facilitate the fine-tuning of the stiffness of the robot joints, the stiffness adjustment part of the present invention also includes a stiffness adjustment bolt and a slider. The slider is installed in a guide groove perpendicular to the axial direction of the compression spring, and is fixedly connected with the stiffness adjustment fulcrum. The stiffness adjusting bolts are respectively arranged at the front and rear ends of the slider, one end of the stiffness adjusting bolt is connected with the slider, and the other end passes through the casing and is threadedly connected with the casing.

As a preferred solution of the present utility model, in order to make the adjustment of the side stiffness module more linear and have a better effect, the two compression springs of the utility model are relatively arranged on the same axis, and the compression springs have the same compression in the initial position. quantity.

As a preferred solution of the utility model, in order to improve the fine-tuning effect of the stiffness, the stiffness adjusting bolt described in the utility model adopts a fine thread bolt, and its pitch is set to 0.5 millimeters.

As a preferred solution of the present utility model, in order to further limit the range of motion of the needle roller and the compression spring, so that the adjustment effect of the stiffness is better, the front end of the compression spring support in the utility model is set as a U-shaped structure to block the needle roller and Push the needle roller against the outer circumferential surface of the cam lever, and the rear end is provided with a depression and cooperates with the compression spring to limit the end of the compression spring.

Further, in order to prevent the stiffness adjusting bolt from protruding from the outer surface of the casing and affect the range of motion of the robot joint, the connection between the stiffness adjusting bolt and the casing of the utility model is provided with a pit for hiding the adjustment fulcrum; the pit The longitudinal section is rectangular.

The working process and principle of the utility model are: during actual work, the variable stiffness module provided by the utility model is mainly used in robot joints. The shell of the variable stiffness module is installed on the output end of the reducer of the robot joint through bolts, and the output disk is fixed with the next joint through bolts. When the robot is disturbed by the external environment or the load is suddenly loaded on the robot, the load will be transmitted to the compression spring through the output disk through the cam lever and the response to the load will become soft, thereby protecting the robot from being damaged and improving the operation of the robot stability etc. When the variable stiffness module works, the output part and the stiffness adjustment lever will deflect at a certain angle relative to the equilibrium position, resulting in an increase in the compression of one compression spring, and a decrease in the compression of the other compression spring. The force balances the external load. The utility model also has the advantages of simple structure, convenient operation and easy implementation.

Compared with the prior art, the utility model also has the following advantages:

(1) The robot joint variable stiffness module based on the cam-type lever structure provided by the utility model adopts the two-stage amplification effect of the cam-type lever and the output disc, so that it can output a large stiffness only by providing a small stiffness value against the spring value, so the overall size of the entire variable stiffness module can be reduced.

(2) The compression spring provided by the robot joint variable stiffness module based on the cam-type lever structure provided by the utility model can buffer the externally applied load, thereby reducing the external impact of the robot joint, realizing flexible drive output, and improving the robot's performance at the same time. robustness and operational stability.

(3) The robot joint variable stiffness module based on the cam-type lever structure provided by the utility model innovatively uses the cam-type lever structure, and the stiffness of the module can be changed only by changing the fulcrum position of the lever. Therefore, the number of parts of the variable stiffness mechanism can be greatly reduced, so that the structure is compact, the weight is light, and the stiffness adjustment range is large.

(4) The robot joint variable stiffness module based on the cam-type lever structure provided by the utility model adopts a modular design method, thereby reducing the application cost of the utility model to a certain extent and can be quickly applied to other equipment . For example, after cooperating with the traditional reducer output in the robot joint, the function of the series elastic driver can be realized.

(5) The variable stiffness module of the robot joint based on the cam-type lever structure provided by the utility model adjusts the fulcrum of the lever by using a fine-threaded bolt with a pitch of only 0.5 mm, which can not only ensure the fine-tuning of the stiffness but also use the fine-threaded thread The self-locking property ensures the invariance of the fulcrum position.

(6) The robot joint variable stiffness module based on the cam lever structure provided by the utility model changes the ratio of the resistance arm to the main force arm by changing the position of the fulcrum, so the stiffness value can be from zero to infinity.

Description of drawings

Fig. 1 is the overall structure schematic diagram of the robot joint variable stiffness module based on the cam type lever structure provided by the utility model;

2 is a schematic diagram of the internal structure of the robot joint variable stiffness module based on the cam-type lever structure provided by the present invention;

Fig. 3 is a schematic diagram of the local structure of the robot joint variable stiffness module based on the cam-type lever structure provided by the present invention.

Explanation of the labels in the above-mentioned accompanying drawings:

1-input part, 2-output part, 3-stiffness adjustment part, 4-bearing, 11-housing, 12-housing bearing ring, 21-output disc, 22-output disc bearing retaining ring, 31-cam lever, 32-axle sleeve, 33-needle roller, 34-stage compression spring support, 35-stage compression spring, 36-stage compression spring mounting seat, 37-stiffness adjustment bolt, 38-slider, 39-stiffness adjustment fulcrum.

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model more clear and definite, the utility model will be further described below with reference to the accompanying drawings and examples.

Example 1:

As shown in FIGS. 1 to 3 , this embodiment discloses a robot joint variable stiffness module based on a cam-type lever structure. The variable stiffness module mainly includes an input part 1 , an output part 2 , and a stiffness adjustment part 3 . The output part 2 is arranged in the input part 1 . A bearing 4 is provided between the input part 1 and the output part 2 to bear the non-torque load of the whole module and make the input part 1 and the output part 2 relatively rotatable.

Specifically, the input part 1 includes a housing 11 and a retaining ring 12 for housing bearings. The casing bearing retaining ring 12 is arranged on the casing 11 and is fixedly connected with the casing 11 . The housing 11 is provided with guide grooves for constraining the compression spring 35 and constraining the rigidity adjustment fulcrum 39 . The guide groove is located at the bottom of the casing 11; the casing 11 is provided with necessary mounting holes and lightening structures.

Specifically, the output part 2 includes an output disk 21 and an output disk bearing retaining ring 22 . The output disk 21 is arranged in the output disk bearing retaining ring 22 and concentrically arranged with the output disk bearing retaining ring 22 . The bearing 4 is arranged in the casing 11 , its outer ring is fixedly connected with the casing bearing retaining ring 12 , and its inner ring is connected with the output disk bearing retaining ring 22 .

Specifically, the stiffness adjustment part 3 includes a compression spring 35 , a cam lever 31 , a needle roller 33 , a compression spring support 34 , a compression spring installation seat 36 , a bushing 32 , and a stiffness adjustment fulcrum 39 . The stiffness adjustment fulcrum 39 is fixed on the cam lever 31 . The cam lever 31 is arranged in the casing 11 and can rotate around the rigidity adjustment fulcrum 39, one end of which is connected with the output disk 21 through the bushing 32, so that the output disk 21 rotates with the cam lever 31 while the other end passes through The needle roller 33 is in contact with the compression spring 35 . The needle roller 33 is installed in the compression spring support 34, and its bottom is clamped in the guide groove, and can move linearly in the guide groove. The compression spring mounting seat 36 is fixed in the casing 11, one end of the compression spring 35 is fixed on the compression spring mounting seat 36, and the other end abuts against the compression spring support 34, forcing the needle roller 33 against the cam lever 31 . The compression spring 35 and the needle roller 33 are arranged in pairs on both sides of the cam lever 31 and arranged symmetrically.

Further, in order to facilitate the fine-tuning of the stiffness of the robot joints, the stiffness adjustment part 3 of the present invention also includes a stiffness adjustment bolt 37 and a slider 38 . The slider 38 is installed in a guide groove perpendicular to the axial direction of the compression spring 35 and is fixedly connected with the stiffness adjustment fulcrum 39 . The stiffness adjusting bolts 37 are respectively arranged at the front and rear ends of the slider 38 , one end of the stiffness adjusting bolt 37 is connected with the slider 38 , and the other end passes through the casing 11 and is threadedly connected with the casing 11 .

As a preferred solution of the present utility model, in order to make the adjustment of the side stiffness module more linear and have a better effect, the two compression springs 35 of the utility model are relatively arranged on the same axis, and the compression springs 35 have the same the amount of compression.

As a preferred solution of the utility model, in order to improve the fine-tuning effect of the stiffness, the stiffness adjusting bolt 37 of the utility model adopts a fine thread bolt, and its pitch is set to 0.5 millimeters.

As a preferred solution of the utility model, in order to further limit the range of motion of the needle roller 33 and the compression spring 35, so that the adjustment effect of the stiffness is better, the front end of the compression spring support 34 in the utility model is set as a U-shaped structure to block Roll the needle 33 and push the needle 33 against the outer peripheral surface of the cam lever 31 , the rear end is provided with a depression and cooperates with the compression spring 35 to limit the end of the compression spring 35 .

Further, in order to prevent the stiffness adjusting bolt 37 from protruding from the outer surface of the casing 11 and affect the range of motion of the robot joints, the connection between the stiffness adjusting bolt 37 and the casing 11 of the present invention is provided with a pit for hiding the adjustment fulcrum; The longitudinal section of the pit is rectangular.

The working process and principle of the utility model are: during actual work, the variable stiffness module provided by the utility model is mainly used in robot joints. The casing 11 of the variable stiffness module is installed on the output end of the reducer of the robot joint through bolts, and the output disc 21 is fixed with the next joint through bolts. When the robot is disturbed by the external environment or the load is suddenly loaded on the robot, the load passes through the output plate 21 and the cam lever 31 to the compression spring 35, and the response to the load becomes soft, thereby protecting the robot from being damaged and improving stability of the robot, etc. When the variable stiffness module works, the output part 2 and the stiffness adjustment lever will deflect at a certain angle relative to the equilibrium position, resulting in an increase in the compression of one compression spring 35, and a decrease in the compression of the other compression spring 35. Through the compression spring The force generated between 35 balances the external load. The utility model also has the advantages of simple structure, convenient operation and easy implementation.

Example 2:

As shown in FIGS. 1 to 3 , this embodiment discloses a robot joint stiffness variable module based on a cam-type lever structure, including an input part 1 , an output part 2 and a stiffness adjustment part 3 . The stiffness adjustment part 3 includes a compression spring 35, a cam lever 31 and a stiffness adjustment fulcrum 39; When the external load is loaded on the output disk 21 of the variable stiffness module, it is transmitted to the compression spring 35 through the action of the cam lever 31. At this time, the compression spring is compressed under the action of the external force and the cam lever 31 is deflected by an angle. The output disk 21 is finally deflected due to the change of the angle of the cam lever 31 . This process is equivalent to when the variable stiffness module is subject to a certain torque load, especially some sudden loads, the compression spring 35 will produce a corresponding force to resist the sudden change of the load through the action of the variable stiffness module, so that the The response to the load becomes smoother. Under a certain external load, when the stiffness of the module is large, the deflection angle of the output disc 21 is small. On the contrary, when the stiffness of the module is small, the deflection angle of the output disk 21 will be large, and the corresponding load response effect will be good. It is precisely because of this process that the robustness and operational stability of the robot are improved, and the compliance of the robot joints is realized. A bearing 4 is provided between the input part 1 and the output part 2 to bear the non-torque load of the whole module and enable the input part 1 and the output part 2 to rotate relatively. The non-torque load is filtered out through the function of the bearing 4 to ensure that only the torque load is loaded into the joint with variable stiffness.

In the specific technical solution of the present utility model, the input part 1 includes a module casing 11 and a bearing retaining ring 12, and the casing 1 is provided with guide grooves for constraining the compression spring and the fulcrum for constraining the stiffness adjustment, and at the same time, the casing 1 is provided with Necessary installation holes and lightening structures. The compression spring 35 and the rigidity adjustment fulcrum 39 are limited to reciprocating motion on a straight line by the action of the guide groove. The output part 2 includes an output disc 21 and a bearing retaining ring 22 . The bearing 4 is respectively fixed on the housing 11 and the output disk 21 through the bearing retaining ring.

In the specific technical solution of the utility model, the two compression springs 35 are arranged oppositely on the same axis, and the compression springs 35 have the same compression amount in the initial position. By adopting the way that two compression springs are arranged oppositely and have the same compression amount so that the mechanism can automatically return to the peaceful point, compared with the solution of a single compression spring 35, the rigidity value will also be doubled. One end of stage clip 35 is fixed with mount 36, stage clip mount 36 is fixed on the casing 11 again to ensure the position of stage clip 35; The moving compression spring support 34 is provided with a needle roller 33 installation hole on the compression spring support 34 . The design of guide groove and needle roller used in this part fully compresses the space of the structure and ensures the compactness of the entire variable stiffness module.

In the specific technical solution of the present utility model, a shaft sleeve 32 is used at the position where one end of the cam lever 31 cooperates with the output part 2 , and a needle roller 33 is used at the position where the other end of the cam lever 31 cooperates with the compression spring 35 . One end of the lever is provided with a boss to cooperate with the hole of the output disk 21, and the friction is reduced through the shaft sleeve 32 in the middle; the cam at the other end is in contact with the needle roller 33 installed in the hole of the support 34. The design of the shaft sleeve is also a better design in this technical solution, which ensures smooth rotation between the output disk 21 and the boss provided on the cam lever 31, and also improves the carrying capacity.

In a specific technical solution of the present invention, the stiffness adjusting bolt 39 is installed on the slider 38 and its position can be adjusted manually. The slide block 38 is installed in the guide groove of the casing 11, and the position of the slide block 38 is adjusted and fixed by two fine thread bolts 37. By adopting fine thread bolts with a pitch of 0.5mm, the stiffness adjustment bolt 39 can only move 0.5mm when the adjustment bolt rotates one turn, which ensures the fine-tuning of the stiffness adjustment. Simultaneously, because the cooperation between the fine pitch threads has self-locking property, it can ensure that the stiffness adjusting bolt 39 does not change during operation.

Referring to Fig. 1 to Fig. 3, it needs to be further explained that, in actual work, this module is mainly used in robot joints. The casing 11 of the variable stiffness module is installed on the output end of the reducer of the robot joint through bolts, and the output disc 21 is fixed with the next joint through bolts. When the robot is disturbed by the external environment or the load is suddenly loaded on the robot, the load passes through the output plate 21 and the cam lever 31 to the compression spring 35, and the response to the load becomes soft, thereby protecting the robot from being damaged and improving stability of the robot, etc. When the variable stiffness module works, the output part 2 and the stiffness adjustment lever 31 will deflect at a certain angle relative to the equilibrium position, thereby causing the compression of one compression spring 35 to increase, and the compression of the other compression spring 35 to decrease. The active force generated between the springs 35 balances the external load.

It should be further explained that, in the technical solution of this embodiment, when the robot rigidity needs to be adjusted, the slider 38 can be adjusted to a proper position by rotating the two fine-threaded bolts 37 so that the module rigidity can reach its desired value. Then two fine thread bolts 37 are tightened to ensure that the position of the slide block 38 will not change.

When designing, it should be noted that the number of compression springs should not be limited to the two in the embodiment, other numbers are also feasible, considering making the structure as compact as possible, the two compression springs in the embodiment are more suitable , if it is necessary to increase the load, consider increasing the number of compression springs; in the stiffness adjustment method, the embodiment also considers making the structure as compact as possible and adopts the manual form, and it is completely possible to use electric when the size requirement is not very high. The form of stiffness adjustment.

It should be noted that the embodiment shown in Fig. 1 to Fig. 3 is only a preferred embodiment introduced by the utility model, and those skilled in the art can design more embodiments on the basis of this. The above description of the disclosed embodiments enables those skilled in the art to realize or use the utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to these embodiments shown herein, but the broadest scope consistent with the principles and novel features disclosed herein.

The above-mentioned embodiment is a preferred implementation mode of the present utility model, but the implementation mode of the present utility model is not limited by the above-mentioned embodiment, and any other changes, modifications and substitutions made without departing from the spirit and principle of the present utility model , combination, and simplification, all should be equivalent replacement methods, and are all included in the protection scope of the present utility model.

Claims (6)

1. a kind of joint of robot variation rigidity module based on cam-type lever construction, which is characterized in that including importation, defeated Part and stiffness tuning part out；The output par, c is arranged in importation；It is divided in the importation and output section Between be equipped with bearing, to bear the non-torque load of entire module, and make importation and output par, c can relative rotation；

The importation includes shell and shell end ring；The shell end ring setting is on the shell, solid with shell Fixed connection；Constraint pressure spring is equipped in the shell and constrains the guide groove of stiffness tuning fulcrum；The guide groove is located at outer casing bottom；Institute Shell is stated equipped with necessary installation hole location and mitigates structure；

The output par, c includes output panel and output panel end ring；The output panel is arranged in output panel end ring, It is arranged concentrically with output panel end ring；Inside the shell, outer ring is fixedly connected with shell end ring, interior for the bearing setting Circle is connect with output panel end ring；

The stiffness tuning part includes pressure spring, cam-type lever, needle roller, pressure spring support, pressure spring mounting base, axle sleeve, Yi Jigang Degree adjusts fulcrum；The stiffness tuning fixed pivot is on cam-type lever；Cam-type lever setting is inside the shell and can It is rotated around stiffness tuning fulcrum, one end is cooperatively connected by axle sleeve and output panel, makes output panel when rotating with cam-type thick stick Bar rotation, the other end are abutted by needle roller with pressure spring；The needle roller is mounted in pressure spring support, and bottom is fastened in guide groove, It can move along a straight line in guide groove；The pressure spring mounting base is fixed inside the shell, and one end of the pressure spring is fixed on pressure spring mounting base On, the other end is abutted with pressure spring support, and needle roller is forced to resist cam-type lever；The pressure spring and needle roller are arranged in pairs at cam-type Lever two sides, and be symmetrical arranged.

2. the joint of robot variation rigidity module according to claim 1 based on cam-type lever construction, which is characterized in that The stiffness tuning part further includes stiffness tuning bolt and sliding block；The sliding block is mounted on the guide groove axially vertical with pressure spring It is interior, and connect with stiffness tuning fixed pivot；The stiffness tuning bolt is separately positioned on the rear and front end of sliding block, stiffness tuning One end of bolt and sliding block are cooperatively connected, and the other end is pierced by shell, and connect with outer casing screw.

3. the joint of robot variation rigidity module according to claim 1 based on cam-type lever construction, which is characterized in that Two pressure springs are positioned opposite on the same axis, and the pressure spring decrement having the same in initial position.

4. the joint of robot variation rigidity module according to claim 2 based on cam-type lever construction, which is characterized in that The stiffness tuning bolt uses bolt of serration, and screw pitch is set as 0.5 millimeter.

5. the joint of robot variation rigidity module according to claim 1 based on cam-type lever construction, which is characterized in that The front end of the pressure spring support is set as U-shaped structure to block needle roller and needle roller is resisted to the outer circumference surface of cam-type lever, rear end Cooperate equipped with recess and with pressure spring with spacing compression spring end.

6. the joint of robot variation rigidity module according to claim 1 based on cam-type lever construction, which is characterized in that It is equipped at the stiffness tuning bolt and cage connection convenient for hiding the pit for adjusting fulcrum；The longitudinal section of the pit is square Shape.