CN113696213B

CN113696213B - Mechanical arm

Info

Publication number: CN113696213B
Application number: CN202111120286.3A
Authority: CN
Inventors: 李家宝
Original assignee: Anhui University of Science and Technology
Current assignee: Anhui University of Science and Technology
Priority date: 2021-09-18
Filing date: 2021-09-18
Publication date: 2022-03-01
Anticipated expiration: 2041-09-18
Also published as: CN113696213A

Abstract

The invention discloses a manipulator, relates to the technical field of industrial automation, and aims to solve the problems that the existing manipulator can only grab objects in a single shape and is small in application range. The present invention provides a manipulator including: a machine base; m foldable mechanical arms fixed or hinged on the base, wherein each mechanical arm is formed by hinging N swing arm units end to end in series, and M and N are positive integers; the M mechanical arms form M fixed points or M hinged points on the base; the N swing arm units are hinged through at least N-1 hinge shafts, and a grabbing space is enclosed among the M mechanical arms; the driving mechanism comprises M driving mechanisms, each driving mechanism corresponds to one mechanical arm, and each driving mechanism comprises a steel belt and a driving unit. The invention adopts the driving mechanism to drive the steel belt to extend, and the articulated shaft of the mechanical arm is limited to bend the mechanical arm, so that the object can be grabbed, the objects with different shapes can be grabbed, and the application range of the mechanical arm for grabbing the objects is enlarged.

Description

Mechanical arm

Technical Field

The invention relates to the field of mechanical automation, in particular to a manipulator.

Background

Most of present manipulators can only grab objects in fixed shapes, if the manipulators grab objects in different types or grab objects in the same shape and different sizes, the manipulators can not be well adapted to the surfaces of the objects, so that different manipulators are needed to complete the grabbing process, the manufacturing cost is increased, and the application range is limited.

Disclosure of Invention

In view of this, the invention discloses a manipulator, which is used for solving the problem that the existing manipulator can only grab objects in a single shape and has a small application range.

In order to achieve the above object, the invention adopts the following technical scheme:

a first aspect of the present invention discloses a manipulator including: a machine base; m foldable mechanical arms fixed or hinged on the base, wherein each mechanical arm is formed by hinging N swing arm units end to end in series, N is more than or equal to 3, M is more than or equal to 2, and M and N are positive integers; m mechanical arms form M fixed points or M hinged points on the base; the N swing arm units are hinged through at least N-1 hinge shafts, and a grabbing space is enclosed among the M mechanical arms; the M driving mechanisms are corresponding to one mechanical arm, each driving mechanism comprises a steel belt and a driving unit, one end of each steel belt sequentially penetrates through the machine base and the N-1 swing arm units and is fixed on the swing arm unit, the distance between the mechanical arm and the fixed point is farthest, and the driving units drive the steel belts to extend, so that the mechanical arm bends towards the grabbing space.

Furthermore, each mechanical arm of the M mechanical arms comprises a root part and an end part, and a swing arm unit positioned at the root part of the mechanical arm is fixed or hinged on the base to form the fixed point or the hinged point; and when the mechanical arm is in a straightened state, the through grooves in the N-1 swing arm units are oppositely arranged.

Further, the swing arm unit with the through grooves is provided with idler wheels on two sides of the steel belt respectively, the idler wheels stretch into the through grooves, and the rotation direction of the idler wheels is the same as the stretching direction of the steel belt.

Further, a Jicun paper folding structure is fixedly connected between every two adjacent swing arm units, the Jicun paper folding structure is buckled on the steel belt, and when the two adjacent swing arm units are bent, the steel belt is kept attached to the Jicun paper folding structure.

Further, when the mechanical arm is in a straightening state, the steel belt in the through groove is arranged on the outer side of the hinge shaft.

Further, the cross section of the steel belt is arc-shaped, and one side of the concave surface of the steel belt faces the grabbing space.

Further, each of the driving units includes: the bracket is fixedly arranged on the base; the driven wheel is rotatably arranged on the bracket; a driving wheel; the driving wheel is rotatably arranged on the bracket and matched with the driven wheel, and the axis of the driving wheel is parallel to the axis of the driven wheel; the winch is rotatably arranged on the bracket, the steel belt is wound on the winch, the other end of the steel belt is fixed on the winch, one end of the steel belt penetrates through the space between the driven wheel and the driving wheel and penetrates out of the base, and the driven wheel and the driving wheel press the steel belt; the executing component is fixedly arranged on the bracket and is used for driving the driving wheel to rotate; the executing component drives the driving wheel to rotate to drive the steel belt to extend out of or retract from the base.

Furthermore, elongated grooves are formed in two sides of the support, the direction of the extension line of the centers of the driven wheel and the driving wheel is the same as the length direction of the elongated grooves, two ends of the driven wheel are rotatably arranged in the elongated grooves, adjusting bolts are connected to two sides of the support in a threaded manner, the length direction of the adjusting bolts is the same as the length direction of the elongated grooves, the end parts of the adjusting bolts are abutted against the end parts of the driven wheel, and the steel belt is tightly pressed between the driving wheel and the driven wheel.

Further, each of the driving units further includes: the outer ring of the volute spiral spring is fixedly connected with the support, the winch is provided with a winch shaft, the winch shaft is rotatably installed on the support, and the winch shaft is fixedly connected with the inner ring of the volute spiral spring.

Further, the outer surface of the driving wheel and the outer surface of the driven wheel are respectively matched with the surface shape of the steel belt on the side where the driving wheel and the driven wheel are respectively attached.

Has the advantages that: the invention adopts the driving mechanism to drive the steel belt to extend, the mechanical arm is bent due to the limitation of the articulated shaft of the mechanical arm, the object is grabbed, and the plurality of swing arm units can adapt to the shape of the surface of the object when being bent, particularly objects with convex edges or convex curved surfaces on the surface, thereby improving the adaptability of the mechanical arm, being capable of grabbing objects with different shapes and enlarging the application range of the mechanical arm for grabbing objects.

Drawings

The above and other objects, features and advantages of the present disclosure will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings. The drawings described below are merely exemplary embodiments of the present disclosure, and other drawings may be derived by those skilled in the art without inventive effort.

FIG. 1 is a schematic view showing the overall structure of a robot according to an embodiment of the present invention;

FIG. 2 illustrates a partial view of a robotic arm in an embodiment of the present invention;

FIG. 3 shows a cross-sectional view A-A of FIG. 2;

FIG. 4 shows a side view of a swing arm unit in an embodiment of the present invention;

FIG. 5 shows a front view of the drive mechanism in an embodiment of the invention;

FIG. 6 shows a left side view of FIG. 5;

fig. 7 shows an internal structural view of the drive mechanism in fig. 5.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the examples of the present invention and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, and "a" and "an" generally include at least two, but do not exclude at least one, unless the context clearly dictates otherwise.

It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a good or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such good or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a commodity or system that includes the element.

Most of present manipulators have a small application range, can only grab objects in a single shape, and if the objects in different types are grabbed, different manipulators are needed to complete the grabbing, so that the manufacturing cost is increased. The invention aims to provide a manipulator, which is used for solving the problem that the existing manipulator is single in application range. The multi-joint mechanical arm is driven by the steel belt to bend, so that the grabbing action of the mechanical arm is realized, and in the grabbing process, the multi-joint can be attached to the surface of an object to firmly grab the object, so that the flexibility and the adaptability of the mechanical arm for grabbing the object are improved.

To further illustrate the technical solution of the present invention, the following specific examples are provided with reference to fig. 1 to 7.

Example 1

In the present embodiment, there is provided a manipulator, as shown in fig. 1 to 3, including: a base 40; m foldable mechanical arms 10 fixed or hinged on the base 40, wherein each mechanical arm 10 is formed by hinging N swing arm units 11 in series end to end, N is more than or equal to 3, M is more than or equal to 2, and M and N are positive integers; the M mechanical arms 10 form M fixed points or M hinged points on the base; the N swing arm units 11 are hinged through at least N-1 hinge shafts, and a grabbing space is enclosed among the M mechanical arms 10; the M driving mechanisms 30 are arranged, each driving mechanism 30 corresponds to one mechanical arm 10, each driving mechanism 30 comprises a steel belt 20 and a driving unit, one end of each steel belt 20 sequentially penetrates through the machine base 40 and the N-1 swing arm units 11 and is fixed on the swing arm unit 11, which is farthest away from the fixed point, of the mechanical arm 10, and the driving unit drives the steel belt 20 to extend, so that the mechanical arm 10 bends towards the grabbing space c.

Each mechanical arm 10 of the M mechanical arms 10 comprises a root part and an end part, and a swing arm unit 11 positioned at the root part of the mechanical arm 10 is fixed or hinged on the base 40 to form the fixed point or the hinge point; any one of the swing arm units 11 at the end of the mechanical arm 10 and the N-1 swing arm units 11 between the machine base 40 is provided with a through groove for the steel belt 20 to pass through, and when the mechanical arm 10 is in a straightening state, the through grooves on the N-1 swing arm units 11 are oppositely arranged.

In a preferred embodiment of the present embodiment, M is 3 to 6.

Alternatively, each swing arm unit 11 has a rod-like structure.

As an embodiment of the present embodiment, the base 40 has a disk shape, and the swing arm units 11 at the root of the robot arm 10 are fixed or hinged to the base 40 and are uniformly arranged along the circumferential direction of the base 40.

The machine base 40 is provided with a groove for the steel strip 20 to pass through, the shape of the groove can be the same as the cross section of the steel strip 20, and the groove extends along the length direction of the mechanical arm 10.

The length direction of the robot arm 10 in this embodiment refers to the extending direction of the robot arm when the robot arm is in a straightened state.

In order to enable the mechanical arm 10 to be in a straightened state when the steel strip 20 is contracted, optionally, protrusions are arranged on two sides of any one of the swing arm units 11 between the root and the end of the mechanical arm 10, and when two adjacent swing arm units 11 rotate around the hinge shaft to enable the two protrusions to abut against each other, the two adjacent swing arm units 11 are in a 180 degree (straightened state).

Further, as shown in fig. 3 and 4, a through groove 111 for the steel belt 20 to pass through is provided in any one of the N-1 swing arm units 11 between the swing arm unit 11 at the end of the mechanical arm 10 and the base 40, when the mechanical arm 10 is in a straightened state, the through grooves 111 on the N-1 swing arm units are oppositely disposed, and the extending direction of the through groove 111 is the same as the length direction of the mechanical arm 10.

As shown in fig. 4, the through-groove 111 has the same shape as the cross-sectional shape of the steel strip 20, and is used for limiting the steel strip 20, shortening the bending length of the steel strip 20, and ensuring that the mechanical arm 10 has sufficient gripping force when the steel strip 20 is elongated.

Further, as shown in fig. 3 and 4, rollers 50 are respectively disposed on two sides of the steel belt 20 of the swing arm unit 11 having the through groove 111, the rollers 50 extend into the through groove 111, the rotation direction of the rollers 50 is the same as the stretching direction of the steel belt 20, and the rollers 50 are disposed to reduce the resistance of the steel belt 20 when the steel belt 20 stretches, so as to prevent the steel belt 20 from being stuck to cause the local bending of the mechanical arm 10 to be too large.

Preferably, the Jicun origami structure 60 is fixedly connected between two adjacent swing arm units 11, the Jicun origami structure 60 is buckled on the steel belt 20, when the two adjacent swing arm units 11 are bent, the steel belt 20 is kept attached to the Jicun origami structure 60, the Jicun origami structure 60 belongs to the prior art, and is made of an elastic material, when the two adjacent swing arm units 11 are bent, the mechanical arm 10 can be ensured to have certain rigidity, and meanwhile, when the two adjacent swing arm units 11 are bent at a large angle, the steel belt 20 is restrained and limited, so that the mechanical arm 10 is prevented from being locally bent too much and out of control. Alternatively, the jicun origami structure 60 may be U-shaped, defining a gap in which the steel band 20 is located.

Specifically, when the arm was in the state of straightening, be located logical inslot the steel band setting is in the outside of articulated shaft, when steel band 20 extended, made arm 10 inside side bend.

Further, the cross section of the steel strip 20 is circular arc, and the concave side of the steel strip 20 faces the grabbing space c.

As shown in fig. 5-7, each driving unit 30 includes a bracket 31, a driven wheel 32, a driving wheel 33, a winch 34 and an actuating member 35, wherein the bracket 31 is fixedly mounted on the machine base 40; the driven wheel 32 is rotatably mounted on the bracket 31; the driving wheel 33 is rotatably mounted on the bracket 31 and is matched with the driven wheel 32, and the axis of the driving wheel is parallel to the axis of the driven wheel 32; the winch 34 is rotatably mounted on the bracket 31, the steel belt 20 is wound on the winch 34, the other end of the steel belt 20 is fixed on the winch 34, one end of the steel belt 20 passes through the space between the driven wheel 32 and the driving wheel 33 and passes out of the base 40, and the driven wheel 32 and the driving wheel 33 press the steel belt 20; the actuating member 35 is fixedly mounted on the bracket 31, and is configured to drive the driving wheel 33 to rotate, in this embodiment, the actuating member 35 may be a motor; the actuating component 35 drives the driving wheel 33 to rotate so as to drive the steel belt 20 to extend or retract from the machine base 40.

In this embodiment, a tensioning structure may be further added to adjust the tensioning force between the driving wheel 33 and the driven wheel 32, specifically, two sides of the bracket 31 are provided with long grooves 311, the direction of the extension line of the centers of the driven wheel 32 and the driving wheel 33 is the same as the length direction of the long grooves 311, the driven wheel 32 is rotatably disposed in the long grooves 311, two sides of the bracket 31 are threadedly connected with adjusting bolts 312, the length direction of the adjusting bolts 312 is the same as the length direction of the long grooves 311, and the end of the adjusting bolts 312 abuts against the end of the driven wheel 32 to press the steel belt 20 between the driving wheel 33 and the driven wheel 32.

Further, each of the driving units 30 further includes: the outer ring of the scroll spring 36 is fixedly connected with the bracket 31, the winch 34 is provided with a winch shaft 341, the winch shaft 341 is rotatably installed on the bracket 31, and the winch shaft is fixedly connected with the inner ring of the scroll spring 36. Specifically, a spiral spring case 361 is fixedly installed on the bracket, an outer ring of the spiral spring 36 is fixed in the spiral spring case 361, and an inner ring of the spiral spring case 361 is fixed on the winch shaft 341.

When the actuating component 35 drives the driving wheel 33 to rotate, so that the steel belt 20 extends to bend the mechanical arm 10, the spiral spring 36 is tightened to generate torsional force on the winch shaft; when the manipulator is released after grabbing an object, the actuating mechanism stops driving the driving wheel 33, the winch shaft drives the steel belt 20 to wind under the driving of the torsional force of the volute spiral spring 36, so that the steel belt 20 is in the initial length, and the manipulator 10 is straightened to release the object.

Further, the outer circumferential surfaces of the driving wheel 33 and the driven wheel 32 are matched with the surface shapes of the steel belt 20 respectively attached to the driving wheel 33 and the driven wheel 32, so that the friction force of the driving wheel 33 and the driven wheel 32 on the steel belt 20 is increased.

Example 2

On the basis of embodiment 1, further, each swing arm unit 11 on each mechanical arm 10 faces towards one side of the grabbing space, a pressure sensor is arranged for detecting the grabbing force of the mechanical arm 10 for grabbing an object, a pressure signal detected by the pressure sensor is transmitted to a controller, the controller judges whether the grabbing force of the mechanical arm 10 reaches a preset threshold value or not through the detected pressure signal, when the grabbing force reaches the preset threshold value, the controller outputs a signal to control the execution part 35 (motor) to stop the output of the steel belt, so as to complete the grabbing of the object, and when the object is to be released, the motor drives the steel belt to contract, so that the mechanical arm is straightened. The motor is connected with a power supply through a relay, and the output end of the controller is electrically connected with the control end of the relay. In this embodiment, the controller may be a PLC controller or a single chip microcomputer.

Exemplary embodiments of the present disclosure are specifically illustrated and described above. It is to be understood that the present disclosure is not limited to the precise arrangements, instrumentalities, or instrumentalities described herein; on the contrary, the disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A manipulator, characterized by comprising:

a machine base;

m foldable mechanical arms fixed on the base, wherein each mechanical arm is formed by hinging N swing arm units in series end to end, N is more than or equal to 3, M is more than or equal to 2, and M and N are positive integers;

m mechanical arms form M fixed points on the base; the N swing arm units are hinged through at least N-1 hinge shafts, and a grabbing space is enclosed among the M mechanical arms;

the M driving mechanisms correspond to each mechanical arm, each driving mechanism comprises a steel belt and a driving unit, one end of each steel belt sequentially penetrates through the base and the N-1 swing arm units and is fixed on the swing arm unit of the mechanical arm, which is farthest away from the fixed point, and the driving units drive the steel belts to extend so that the mechanical arm is bent towards the grabbing space;

and when two adjacent swing arm units are bent, the steel belt is kept attached to the Jicun paper folding structure.

2. A manipulator according to claim 1, wherein each arm of the M arms comprises a root and an end, and the swing arm unit at the root of the arm is fixed to the base to form the fixed point; and when the mechanical arm is in a straightened state, the through grooves in the N-1 swing arm units are oppositely arranged.

3. A manipulator according to claim 2, wherein the arm swinging unit having the through-slots is provided with rollers on both sides of the steel strip, the rollers extending into the through-slots, and the rollers rotate in the same direction as the steel strip.

4. A manipulator according to claim 3, wherein the steel strips in the through slots are disposed outside the hinge axes when the manipulator is in the straightened state.

5. A manipulator according to claim 4, wherein the steel strip has a circular arc-shaped cross-section, the concave side of the steel strip facing the gripping space.

6. A manipulator according to any of claims 1 to 5, wherein each of the drive units comprises:

the bracket is fixedly arranged on the base;

the driven wheel is rotatably arranged on the bracket;

a driving wheel; the driving wheel is rotatably arranged on the bracket and matched with the driven wheel, and the axis of the driving wheel is parallel to the axis of the driven wheel;

the winch is rotatably arranged on the bracket, the steel belt is wound on the winch, the other end of the steel belt is fixed on the winch, one end of the steel belt penetrates through the space between the driven wheel and the driving wheel and penetrates out of the base, and the driven wheel and the driving wheel press the steel belt;

the executing component is fixedly arranged on the bracket and is used for driving the driving wheel to rotate;

the executing component drives the driving wheel to rotate to drive the steel belt to extend out of or retract from the base.

7. A manipulator according to claim 6, wherein elongated slots are formed in both sides of the support, the direction of the extension lines of the centers of the driven wheel and the driving wheel is the same as the length direction of the elongated slots, both ends of the driven wheel are rotatably disposed in the elongated slots, adjusting bolts are threadedly connected to both sides of the support, the length direction of the adjusting bolts is the same as the length direction of the elongated slots, and the ends of the adjusting bolts abut against the ends of the driven wheel to press the steel belt between the driving wheel and the driven wheel.

8. A manipulator according to claim 7, wherein each drive unit further comprises:

the outer ring of the volute spiral spring is fixedly connected with the support, the winch is provided with a winch shaft, the winch shaft is rotatably installed on the support, and the winch shaft is fixedly connected with the inner ring of the volute spiral spring.

9. A manipulator according to claim 8, wherein the outer surface of the driving wheel and the outer surface of the driven wheel conform to the shape of the steel strip on the respective sides to which they respectively abut.