CN209551780U - Flexible wrist joint for robot and robot - Google Patents

Abstract

The utility model discloses a flexible wrist joint for a robot, which comprises: a shell, which is provided with a cavity inside, and is provided with a communication cavity for the input port of external air pressure or hydraulic equipment; an end cover, which is connected with the cavity of the shell The opening is fixedly connected, the end cover is provided with an opening groove, and the end cover is provided with a number of grooves on the side facing the cavity; the floating block forms a sealed cavity with the shell, which includes a collar and a movable body, and the collar is placed It is close to the inner wall of the shell in the cavity and is axially slidably connected with the shell. The inner wall of the collar is set in a spherical shape; one end of the movable body extends into the collar, and the end that extends into the collar matches the shape of the inner wall of the collar to form a spherical shape. The other end of the movable body protrudes from the end cover through the open slot and there is an active gap between the open slot and the movable body is provided with a number of thimbles matching with the groove, the inner diameter of the groove is larger than the outer diameter of the thimble, the utility model can Movement with multiple degrees of freedom.

Description

Flexible wrist joint for robot and robot

technical field

The utility model belongs to the field of robots, and more specifically relates to a flexible wrist joint for a robot.

Background technique

At present, the application of industrial robots is becoming more and more common, and the scope of application is becoming wider and wider. Due to its own structure, articulated industrial robots have relatively high repeatability and low positioning accuracy. This feature leads to limited application of industrial robots in the field of assembly and processing.

The existing solution is to use a high-precision six-dimensional force sensor as a transitional connection between the robot and the actuator. The six-dimensional force sensor can detect the forces in the three directions of x, y, and z and the torque around the three axes. The force and torque signals obtained by the sensor are fed back to the robot's control system, so that the robot can respond accordingly. However, this method has the following disadvantages: 1. The cost of the force sensor is relatively high, and the feedback control system is relatively complicated, which is not conducive to widespread promotion and application. 2. There is a time lag in the force feedback control system. After the collision occurs, the system will delay for a certain period of time to produce corresponding actions. However, when the control system responds, the workpiece may have been destroyed.

Another solution is to control the pressure of the cylinder on the workpiece through a single-axis cylinder and a servo valve, but this way is that the single-degree-of-freedom mechanism only works in one direction, and the six-degree-of-freedom robot used in industry has a degree of freedom of motion More often, the contact between the performing tool and the workpiece is multidimensional. To meet the demand, it is necessary to use multiple single-degree-of-freedom mechanisms in series, which reduces the stiffness of the system, increases the error, complicates the control, and increases the cost.

Utility model content

Aiming at the deficiencies of the prior art, the utility model provides a multi-degree-of-freedom movement, which solves the problem that the robot cannot move flexibly or the signal feedback is delayed during the assembly and processing process, resulting in collision damage to the workpiece.

In order to achieve the above object, the utility model provides the following technical solution: a flexible wrist joint for a robot, comprising:

The shell is provided with a cavity inside, and is provided with a communication cavity for the input port of external air pressure or hydraulic equipment;

The end cover is fixedly connected with the opening of the cavity of the shell, the end cover is provided with an opening groove, and the end cover is provided with a number of grooves on the side facing the inside of the cavity;

The floating block forms a sealed cavity with the shell, which includes a collar and a movable body, the collar is placed in the cavity, close to the inner wall of the shell and is axially slidably connected with the shell, and the inner wall of the collar is spherical;

One end of the movable body extends into the collar, and one end extending into the collar matches the shape of the inner wall of the collar to form a spherical shape. A plurality of thimbles matching the grooves are arranged on the movable body, and the inner diameter of the grooves is larger than the outer diameter of the thimbles.

Further, the groove is conical or spherical, and the end of the thimble is arc-shaped.

Further, a step is provided on the inner wall of the casing, the inner diameter of the side of the casing near the end cap is larger than the inner diameter of the other side, the collar is placed at a place with a larger inner diameter, and the input port is located at a place with a smaller inner diameter.

Further, the collar includes an upper ring and a lower ring, the upper ring and the lower ring are fixedly connected, and a sealing member is arranged between the upper ring and the lower ring.

Further, a quick-change connecting plate is detachably connected to the floating block.

Further, the other side of the housing corresponding to the end cover is provided with a flange for connecting with the mechanical arm.

Further, a quick-plug connector is provided at the input port of the housing.

A robot includes a flexible wrist joint for the robot.

Compared with the prior art, the beneficial effect of the utility model is that the floating block and the shell are movably connected, and a sealed cavity is formed between the two, and the sealed cavity can be inflated with gas or liquid and the pressure can be controlled externally, so that the working When the floating block is subjected to the combined action of external force and gas or liquid pressure, it will float accordingly under the cooperation of the thimble on the floating block, so that the corresponding point of balance force can be found. When the external force acting on the workpiece is greater than the pressure of the gas or liquid in the sealed cavity, the slider can move along the axis direction or deflect obliquely relative to the axis direction, so as to prevent excessive force from damaging the workpiece or the execution tool; when the external force is less than When there is gas or liquid pressure in the sealed chamber, the floating block can be reset under the cooperation and guidance of the thimble and the groove, so that the entire floating block is coaxial with the casing and the thimble is against the bottom of the groove; When the load exceeds the set load, it automatically avoids the action point of the workpiece and floats. It can move in the axial direction and in the circumferential direction, and can act at the same time, and then automatically reset.

Description of drawings

Fig. 1 is the three-dimensional structural diagram of the flexible wrist joint of robot of the present invention;

Fig. 2 is the sectional structural schematic diagram of the flexible wrist joint of robot of the present invention;

Fig. 3 is a state diagram when the slider moves axially in the utility model;

Fig. 4 is a state diagram of the utility model when the slider deflects relative to the axis.

Reference signs: 1. shell; 12. ladder; 2. floating block; 21. collar; 22. movable body; 3. end cover; 4. quick-change connecting plate; 71, thimble; 72, groove; 8, movable gap.

Detailed ways

The embodiment of the flexible wrist joint for the robot of the present invention will be further described with reference to Fig. 1 to Fig. 4 .

A flexible wrist joint for a robot, comprising:

The shell 1 is provided with a cavity inside, and is provided with a communication cavity for the input port of external air pressure or hydraulic equipment;

The end cover 3 is fixedly connected with the opening of the cavity of the shell 1, the end cover 3 is provided with an opening groove, and the end cover 3 is provided with a plurality of grooves 72 toward the inner side of the cavity;

The floating block 2 forms a sealed cavity 6 with the housing 1, which includes a collar 21 and a movable body 22. The collar 21 is placed in the cavity, close to the inner wall of the housing 1 and is axially slidably connected with the housing 1. The collar 21. The inner wall is set to be spherical;

One end of the movable body 22 extends into the collar 21, and one end of the inner wall of the collar 21 matches the shape of the inner wall of the collar 21 to form a spherical shape. A movable gap 8 is left, and the movable body 22 is provided with a plurality of thimbles 71 matching with grooves 72 , and the inner diameter of the grooves 72 is larger than the outer diameter of the thimbles 71 .

When in use, one end of the housing is connected to a mechanical arm, and the other end is connected to an execution tool (such as a gripper or a tool with a driving motor, etc.).

The spherical curvature of the movable body 22 and the collar 21 is the same, and the connection between the two is always in a sealed state.

As shown in Figure 2, gas or liquid is introduced into the sealed cavity 6 through the input port, so that the floating block 2 has a back pressure, and the pressure in the sealed cavity 6 (that is, the back pressure) is set by an external device. At this time, the entire floating The block 2 is pushed out of the housing, and the thimble 71 on the floating block 2 will extend into the bottom of the groove 72 on the end cover 3. The entire floating block 2 is in a positive posture, that is, the floating block 2 is coaxial with the shell 1, and the floating block 2 is in a positive position. 2. One end of the end cover 3 is extended to connect the execution tool, and the execution tool normally operates on the workpiece.

As shown in Figure 3, when working, if the axial force between the tool and the workpiece is greater than the back pressure, the floating block 2 will slide between the collar 21 and the housing to move towards the sealing chamber 6, The floating block 2 slides a distance a to the sealing cavity 6 as a whole, so as to avoid the execution tool or workpiece from being damaged by a rigid collision greater than its bearing capacity, and when the axial force between the execution tool and the workpiece is less than the back pressure, the entire floating block 2 It will be automatically reset, wherein the thimble 71 and the groove 72 will be aligned and guided to ensure that the slider 2 is coaxial with the housing 1 .

As shown in Figure 4, when working, if the radial force between the tool and the workpiece is greater than the back pressure at this time, the floating block 2 will rotate through the spherical cooperation between the movable body 22 and the collar 21, and the movable body 22 The deflection angle with the axis is b. At this time, the thimble 71 is always in the range of the groove 72 and does not come out. It can limit the range of deflection of the movable body 22. At the same time, the movable gap 8 between the movable body 22 and the end cover 3 is also The deflection of the movable body 22 provides protection. After the radial force between the execution tool and the workpiece is less than the pressed one, the back pressure squeezes the movable body 22 of the floating block 2, and the movable body 22 will cooperate with the thimble 71 and the groove 72. Alignment guide, so that the entire slider 2 resets and is coaxial with the housing 1 .

The actuating tool may also be squeezed axially and radially at the same time. At this time, the collar 21 slides, and the movable body 22 rotates at the same time. The two movements are independent of each other and will not be described here.

In this embodiment, the housing 1 includes a connection part for connecting with the mechanical arm and a sleeve part for matching with the slider 2. In this embodiment, the one-piece type is described, but it is not limited to this, and it can also be a split type. The firmware is linked together.

Wherein, the end cover 3 and the shell 1 can be fixed by fasteners, or can be fixed by threaded cooperation between the two.

The groove 72 preferred in this embodiment is conical or spherical, and the end of the thimble 71 is arc-shaped. Freely move in 72, but can't break away from the scope of groove 72.

The number of thimbles 71 is three, four or more. The length of the thimble 71 of the floating block 2 is slightly longer than the set axial displacement, and its top is spherical or ellipsoidal. When the floating block 2 is axially displaced, the thimble 71 of the floating block 2 The matching part with the groove 72 of the end cover 3 does not act as a restriction; when the floating block 2 swings around the center of the ball, the matching part acts as a restriction within a certain angle range. When the floating block 2 is subjected to external force, it usually makes the floating block 2 move axially and swing around the center of the ball at the same time. With the pressure input from the outside, the manipulator can make the multi-degree-of-freedom flexible movement with a certain resistance to realize the manual movement. Adaptive positioning of claws.

In this embodiment, the inner wall of the housing 1 is preferably provided with a step 12, the inner diameter of the side of the housing 1 near the end cover 3 is larger than the inner diameter of the other side, the collar 21 is placed at a place with a larger inner diameter, and the input port is located at the inner diameter In the smaller part, the step 12 can limit the range of movement of the collar 21, ensuring that the thimble 71 is always active within the range of the groove 72, and the corresponding step 12 of the shell 1 can be integrated, that is, two directly different spaces are produced during processing. cavities, or connected by fasteners in a split type.

In this embodiment, the preferred collar 21 includes an upper ring and a lower ring, the upper ring and the lower ring are fixedly connected, and a seal is provided between the upper ring and the lower ring to facilitate assembly with the movable body 22. In order to achieve sealing For the sealing of chamber 6, additional sealing components can be added at the required positions.

In this embodiment, the floating block 2 is preferably detachably connected with a quick-change connecting plate 4, and different quick-changing connecting plates 4 can be replaced according to the required execution tools, so that the whole robot can use different tools to work.

In this embodiment, preferably, the other side of the housing 1 corresponding to the end cover 3 is provided with a flange for connecting with the mechanical arm.

In this embodiment, the input port of the housing 1 is preferably provided with a quick-plug connector 5, which is plug-and-play and convenient for connection.

A robot utilizing the flexible wrist joint described above.

The above descriptions are only preferred implementations of the present utility model, and the protection scope of the present utility model is not limited to the above-mentioned embodiments, and all technical solutions under the idea of the present utility model all belong to the protection scope of the present utility model. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principle of the utility model should also be regarded as the protection scope of the utility model.

Claims (8)

1. A flexible wrist joint for a robot, characterized in that it comprises: The shell is provided with a cavity inside, and is provided with a communication cavity for the input port of external air pressure or hydraulic equipment; The end cover is fixedly connected with the opening of the cavity of the shell, the end cover is provided with an opening groove, and the end cover is provided with a number of grooves on the side facing the inside of the cavity; The floating block forms a sealed cavity with the shell, which includes a collar and a movable body, the collar is placed in the cavity, close to the inner wall of the shell and is axially slidably connected with the shell, and the inner wall of the collar is spherical; One end of the movable body extends into the collar, and one end extending into the collar matches the shape of the inner wall of the collar to form a spherical shape. A plurality of thimbles matching the grooves are arranged on the movable body, and the inner diameter of the grooves is larger than the outer diameter of the thimbles. 2 . The flexible wrist joint for robots according to claim 1 , wherein the groove is conical or spherical, and the end of the thimble is arc-shaped. 3 . 3. The flexible wrist joint for robots according to claim 1, characterized in that: the inner wall of the housing is provided with a step, the inner diameter of the side of the housing near the end cap is larger than the inner diameter of the other side, and the collar is placed Where the inner diameter is larger, the input port is located at a smaller inner diameter. 4. The flexible wrist joint for robots according to claim 2 or 3, characterized in that: the collar includes an upper ring and a lower ring, the upper ring and the lower ring are fixedly connected, and a ring is arranged between the upper ring and the lower ring There are seals. 5 . The flexible wrist joint for robots according to claim 4 , wherein a quick-change connecting plate is detachably connected to the floating block. 6 . The flexible wrist joint for a robot according to claim 5 , wherein the other side of the housing corresponding to the end cover is provided with a flange for connecting with the mechanical arm. 7 . 7 . The flexible wrist joint for a robot according to claim 6 , wherein a quick-plug connector is provided at the input port of the housing. 8 . 8. A robot, characterized in that it comprises the flexible wrist joint for a robot according to any one of claims 1-7.