TWI440521B - Parallel mechanism and moveable linkage thereof - Google Patents

Description

Parallel mechanism and its translational branch

The invention relates to a parallel mechanism, in particular to a parallel mechanism for an industrial robot and a translational branch thereof.

In recent years, multi-degree-of-freedom parallel mechanisms have been widely used in industrial production, and are widely used in industrial robots to achieve multi-directional rapid motion. At present, the four-degree-of-freedom parallel mechanism is the most widely used. As shown in FIG. 1 , it is a schematic structural diagram of a conventional four-degree-of-freedom parallel mechanism 100 , which generally includes a static platform 11 , a movable platform 12 , and a rotating branch 11 and a three translational branch connecting the static platform 11 and the movable platform 12 . 15. The rotating branch 13 can realize independent rotational movement, and the three translational branches 15 can realize the translational movement of XYZ three-dimensionality. Each of the translational branches 15 includes a swinging control arm 151 and a four-bar linkage structure 152, and the swinging control arm 151 is movably coupled to the stationary platform 11. The four links of the four-link structure 152 are rotatably connected by a ball hinge 153, wherein the two oppositely disposed links are fixedly connected to the swing control arm 151 and the movable platform 12, respectively. During operation, the motor or other driver drives the swing control arm 151 to make a certain angle of the swing motion to drive the four-link structure 152 to open, translate, and rotate, thereby realizing the three-dimensional motion of the movable platform 12.

However, the links of the four-link structure 152 are rotatably connected by the ball hinge 153. Since the yaw angle of the ball hinge can be limited (generally within 25 degrees), the translation distance of the four-link structure 152 is limited. , resulting in the use of a four-link structure 152 The flexibility of the joint agency 100 is poor. Moreover, the ball hinge is not easy to process, the matching gap between the connecting rod and the ball hinge is difficult to control, and the assembly process is complicated, resulting in a high production cost of the parallel mechanism 100 using the four-link structure 152.

In view of the above, it is necessary to provide a parallel mechanism with high flexibility of movement and low production cost and its translational branch.

A translational branch for a parallel mechanism, comprising a swing control arm and a four-link structure rotatably coupled to the swing control arm, the four-link structure comprising a first connecting shaft, a second connecting shaft, a first connecting rod, and a first connecting rod a two-link, the swing control arm is rotatably coupled to the first connecting shaft, the four-link structure further comprising a four-connecting assembly, the ends of the first and second connecting rods and the ends of the first and second connecting shafts The portions overlap to form a quadrilateral, and are rotatably connected by the four connecting components, each connecting component includes a rotating shaft, a sleeve and a lock, and the two ends of the first connecting rod and the two ends of the second connecting rod respectively have an axis a hole, each sleeve is sleeved on the corresponding rotating shaft, and is inserted into the corresponding shaft hole together with the rotating shaft, and the rotating shaft passes through a corresponding first connecting shaft or second connecting shaft overlapping the end portion of the shaft hole And locked with the corresponding lock firmware.

A parallel mechanism for an industrial robot includes a static platform, a moving platform, a rotating branch, and the above-mentioned translational branch, and the rotating branch and the translational branch connect the static platform and the movable platform.

In the above parallel mechanism, the first and second links of the four-link structure overlap with the ends of the first and second connecting shafts and are rotationally coupled by the rotating shaft, and the first and second links are opposite to the first and second links. The range of rotation angle of the connecting shaft is large, so the translation distance of the translational branch is large, so that the working space of the parallel mechanism is large, and the movement flexibility is improved. Moreover, the four-bar linkage structure adopting the rotating shaft connection method is easy to manufacture and assemble, and the production cost is low.

200‧‧‧ parallel mechanism

10‧‧‧ Static platform

20‧‧‧moving platform

30‧‧‧Rotating branches

50‧‧‧ translational branch

51‧‧‧Swing control arm

511‧‧‧ pivotal department

512‧‧‧ swinging section

513‧‧‧ pivoting department

5131‧‧‧ pivot hole

52‧‧‧ four-bar linkage structure

521‧‧‧First connecting shaft

5211‧‧‧Rotary shaft

5212‧‧‧Transformation shaft

5213‧‧‧Flange

5214‧‧‧Threaded Department

5215‧‧‧ shaft hole

522‧‧‧Second connecting shaft

523‧‧‧first link

5231‧‧‧Connecting Department

5232‧‧‧Axis hole

524‧‧‧second link

525‧‧‧Connecting components

5251‧‧‧ shaft

5252‧‧‧ bushing

5253‧‧‧Locker

526‧‧‧ pivoting components

5261‧‧‧ sleeve

5262‧‧‧Friction gasket

5263‧‧‧Responsible parts

5265‧‧‧Locker

60‧‧‧ drive parts

Figure 1 is a schematic view showing the structure of a conventional four-degree-of-freedom parallel mechanism.

2 is a schematic plan view of a parallel mechanism in accordance with a preferred embodiment of the present invention.

3 is a perspective assembled view of a translational branch of a preferred embodiment of the present invention.

Figure 4 is an exploded perspective view of the translational branch of Figure 3.

The parallel mechanism of the present invention and its translational branch will be further described in detail below with reference to the accompanying drawings and preferred embodiments.

Referring to FIG. 2, the parallel mechanism 200 of the preferred embodiment of the present invention is a four-degree-of-freedom parallel mechanism, which includes a static platform 10, a moving platform 20, and a rotating platform 10 and a movable platform 20. Branch 50. The rotating branch 30 and the translational branch 50 are movably coupled to the stationary platform 10 by a drive member 60.

Referring to FIG. 3 and FIG. 4 simultaneously, each translational branch 50 includes a swing control arm 51 and a four-link structure 52. The four-link structure 52 includes a first connecting shaft 521, a second connecting shaft 522, a first connecting rod 523, a second connecting rod 524, a plurality of connecting assemblies 525, and two pivoting assemblies 526. The first connecting shaft 521 is rotatably connected to the swinging control arm 51, the second connecting shaft 522 is rotatably connected to the movable platform 20, and the first and second connecting rods 523 and 524 are respectively connected to the first and second connecting shafts 521 by the connecting component 525. 522 is rotated and connected.

The swing control arm 51 includes a pivot portion 511 and a swing portion 512. An end portion of the swinging portion 512 is formed with a substantially cylindrical pivot portion 513, and the pivot portion 513 defines a circular pivot hole 5131.

The first connecting shaft 521 includes a rotating shaft portion 5211 and a deforming shaft portion 5212 extending perpendicularly outward from both ends of the rotating shaft portion 5211. The joint of the rotating shaft portion 5211 and the two deforming shaft portions 5212 A flange 5213 and a threaded portion 5214 are formed respectively, and the end portions of the two deformed shaft portions 5212 respectively define a shaft hole 5215.

The structure of the second connecting shaft 522 is the same as that of the first connecting shaft 521.

The first connecting rod 523 is substantially elongated, and the first end portion, the second end portion and the middle portion are formed with a substantially cylindrical connecting portion 5231. The connecting portion 5231 defines a circular shaft hole 5232.

The second link 524 has the same structure as the first link 523.

Each connecting component 525 includes a rotating shaft 5251, a sleeve 5252 and a locking member 5253. The end of the rotating shaft 5251 is provided with a threaded portion (not shown) that can be locked with the locking member 5253. The outer diameter of the sleeve 5252 is slightly smaller than the radius of the shaft hole 5232. Therefore, the sleeve 5252 can be placed in the shaft hole 5232. .

Each pivoting assembly 526 includes a sleeve 5261, a friction pad 5262, a resisting member 5263, and a locking member 5265. The outer diameter of the sleeve 5261 is slightly smaller than the radius of the pivot hole 5131, so the sleeve 5261 can be placed in the pivot hole 5131.

Referring to FIG. 2 at the same time, during assembly, the pivoting portion 511 of the swinging control arm 51 is rotatably coupled to the driving member 60 disposed on the stationary platform 10, and the swinging portion 512 is rotatably coupled to the first connecting shaft 521. The sleeve 5261 is sleeved on the rotating shaft portion 5211 of the first connecting shaft 521. The first connecting shaft 521 is disposed through the pivoting portion 513 of the swinging control arm 51. The rotating shaft portion 5211 is located in the pivot hole 5131 together with the sleeve 5261. The flange 5213 is abutted on the side of the pivot hole 5131 to prevent the sleeve 5261 from coming out. The friction pad 5262 and the resisting member 5263 are sleeved on the threaded portion 5214 of the first connecting shaft 521, and the locking member 5265 is screwed on the threaded portion. The 5214 is pushed and pressed against the resisting member 5263 and the friction pad 5262 to increase the rotational stability of the first connecting shaft 521 relative to the swinging control arm 51.

Then, the first ends of the first and second links 523 and 524 are respectively rotatably connected to the two ends of the first connecting shaft 521. The sleeve 5252 is sleeved on the rotating shaft 5251. The rotating shaft 5251 sequentially passes through the shaft hole 5232 of the first connecting rod 523 and the shaft hole 5215 of the first connecting shaft 521 and is engaged with the locking member 5253. Thus, the first end of the first link 523 overlaps with one end of the first connecting shaft 521 and is rotatably connected by the connecting component 525. The first end of the second link 524 is rotatably coupled to the other end of the first connecting shaft 521 in the same manner.

Finally, the second connecting shaft 522 is rotatably connected to the moving platform 20 in the same manner as the first connecting shaft 521 and the swing control arm 51. The second ends of the first and second links 523 and 524 are respectively overlapped with the two ends of the second connecting shaft 522 and rotatably connected by the connecting member 525.

Further, the four-link structure 52 further includes a reinforcing rod 527, the two ends of which are respectively rotatably connected to the middle portions of the first and second links 523, 524 by the connecting assembly 525. The reinforcing rod 527 can increase the rigidity of the four-link structure 52, and can ensure that the four-link structure 52 is always in the same plane during motion, thereby improving the smoothness of the translational branch 50 in motion.

During operation, the rotating branch 30 can be rotated by a driving device such as a motor, and the swinging control arm 51 can be rotated by a certain angle with respect to the static platform 10 under the driving of a driving device such as a motor to drive the four companies. The rod structure 52 is closed, translated, and rotated, thereby realizing the translational movement of the translational branch 50 in the XYZ three-dimensional degree. Thus, the rotating branch 30 and the three translational branches 50 cooperate to drive the movable platform 20 to perform movements such as rotation, lifting, translation, and the like. The movable platform 20 can fix the working end of the industrial robot or the tool of the machine tool to complete tasks such as workpiece picking and placing, tool cutting and drilling in industrial production.

In the parallel mechanism 200 of the present invention, the rotation of the first and second links 523, 524 relative to the first and second connecting shafts 521, 522 is not restricted by the connecting component 525. The range of the moving angle is large (about 60 degrees), so the translation distance of the translational branch 50 is large, so that the working space of the parallel mechanism 200 is large, and the movement flexibility is improved. Moreover, the four-bar linkage structure 52 adopting the rotating shaft connection method is easy to manufacture and assemble, and the production cost is low.

In addition, the four-link structure 52 is provided with a reinforcing rod 527, which can increase the rigidity of the four-link structure 52 and improve the smoothness of the translational branch 50 in motion.

The sleeves 5261 are sleeved on the first and second connecting shafts 521 and 522, so that the matching gap between the first and second connecting shafts 521 and 522 and the swinging control arm 51 and the movable platform 20 is small, and the motion stability is improved. And can protect the first and second connecting shafts 521, 522 from being worn. The sleeve 5252 is sleeved on the rotating shaft 5251, and the matching gap between the first and second connecting rods 523 and 524 and the rotating shaft 5251 can be reduced, and the movement stability of the translational branch 50 can be improved to ensure the working precision of the industrial robot. It is also possible to protect the rotating shaft 5251 from wear, thereby extending the working life of the parallel mechanism 200.

In addition, the parallel mechanism 200 is not limited to a four-degree-of-freedom parallel mechanism, and may be other multi-degree-of-freedom parallel mechanisms. The sleeve 5261, the friction pad 5262, the abutment 5263, the sleeve 5252, and the reinforcing bar 527 may be omitted.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

50‧‧‧ translational branch

51‧‧‧Swing control arm

511‧‧‧ pivotal department

512‧‧‧ swinging department

513‧‧‧ pivoting department

5131‧‧‧ pivot hole

521‧‧‧First connecting shaft

5211‧‧‧Rotary shaft

5212‧‧‧Transformation shaft

5213‧‧‧Flange

5214‧‧‧Threaded Department

5215‧‧‧ shaft hole

522‧‧‧Second connecting shaft

523‧‧‧first link

5231‧‧‧Connecting Department

5232‧‧‧Axis hole

524‧‧‧second link

525‧‧‧Connecting components

5251‧‧‧ shaft

5252‧‧‧ bushing

5253‧‧‧Locker

526‧‧‧ pivoting components

5261‧‧‧ sleeve

5262‧‧‧Friction gasket

5263‧‧‧Responsible parts

5265‧‧‧Locker

Claims (11)

A translational branch for a parallel mechanism, comprising a swing control arm and a four-link structure rotatably coupled to the swing control arm, the four-link structure comprising a first connecting shaft, a second connecting shaft, a first connecting rod and a The two-link is improved in that the swing control arm is rotatably connected to the first connecting shaft, and the four-link structure further includes four connecting components, the ends of the first and second connecting rods are opposite to the first and second ends The ends of the connecting shaft are overlapped to form a quadrilateral, and are rotatably connected by the four connecting components, each connecting component comprises a rotating shaft, a sleeve and a lock, and the two ends of the first connecting rod and the two ends of the second connecting rod Each of the shaft sleeves is sleeved on the corresponding rotating shaft, and is disposed in the corresponding shaft hole together with the rotating shaft, and the rotating shaft passes through a corresponding first connecting shaft overlapping with the end portion of the shaft hole or The second connecting shaft is locked with the corresponding locking firmware. The translational branch of claim 1, wherein the four-link structure further comprises a reinforcing rod rotatably disposed between the first and second links. The translational branch of claim 1, wherein the swing control arm comprises a pivoting portion, the first connecting shaft comprising a rotating shaft portion, the rotating shaft portion rotatably passing the pivoting portion. The translational branch of the third aspect of the invention, wherein the four-link structure further comprises a sleeve sleeved on a rotating shaft portion of the first connecting shaft and located at the pivoting portion together with the rotating shaft portion Inside the department. The translational branch of claim 1, wherein the first and second links respectively have a first end and a second end, and the first ends of the first and second links are respectively The two ends of the first connecting shaft are overlapped and rotatably connected by the rotating shaft, and the second ends of the first and second connecting rods respectively overlap the two ends of the second connecting shaft and are rotatably connected by the rotating shaft. A parallel mechanism for an industrial robot, comprising a static platform, a moving platform, and a rotating branch and a translational branch connecting the static platform and the moving platform, the translational branch comprising a swinging control arm and The swing control arm is rotatably connected to the four-link structure, the four-link structure includes a first connecting shaft, a second connecting shaft, a first connecting rod and a second connecting rod, and the improvement is that the swinging control arm and the first The connecting shaft is rotatably connected, and the four-link structure further includes a four-connecting assembly, the ends of the first and second connecting rods overlapping with the ends of the first and second connecting shafts to form a quadrilateral, and by the four-connecting Each of the connecting components includes a rotating shaft, a sleeve and a lock, and the two ends of the first connecting rod and the two ends of the second connecting rod are respectively provided with shaft holes, and each of the sleeves is sleeved on the corresponding rotating shaft, And passing through the corresponding shaft hole together with the rotating shaft, and the rotating shaft passes through a corresponding first connecting shaft or second connecting shaft overlapping the end portion of the shaft hole, and is locked with the corresponding locking member. The parallel mechanism of claim 6, wherein the swing control arm is movably connected to the static platform; the second connecting shaft is rotatably coupled to the movable platform. The parallel mechanism of claim 7, wherein the four-link structure further comprises a sleeve sleeved on the first and second connecting shafts, and the first and second connecting shafts The swing control arm and the movable platform are worn together. The parallel mechanism of claim 6, wherein the four-link structure further comprises a reinforcing rod rotatably disposed between the first and second links. The parallel mechanism according to claim 6, wherein the swing control arm includes a pivoting portion, and the first connecting shaft includes a rotating shaft portion, and the rotating shaft portion rotatably penetrates the pivoting portion. The parallel mechanism of claim 6, wherein the first and second links respectively have a first end and a second end, and the first ends of the first and second links respectively The two ends of the first connecting shaft are overlapped and rotatably connected by the rotating shaft, and the second ends of the first and second connecting rods respectively overlap the two ends of the second connecting shaft and are rotatably connected by the rotating shaft.