JPH0724219Y2 - Arm drive axis lock device for articulated robot - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a lock device for an arm drive shaft such as an upper arm or a forearm of an articulated lock. More specifically, when attaching or detaching a drive motor for driving each drive shaft , A device for locking the drive shaft.

B. Outline of the device For the arm drive axes of the articulated robot's upper arm, forearm, etc.,
A worm wheel was fitted close to a connecting portion with a drive motor for driving the drive shaft, and a lid body was provided that was fitted with the worm wheel, meshed with the worm wheel, and manually rotatable from outside the case. Every other time, by attaching the lid body instead of the regular lid and locking the drive shaft,
The drive motor can be safely attached / detached without attaching / detaching a fixing metal fitting for preventing movement of the upper arm or the forearm.

C. Prior Art FIGS. 3 and 4 are views showing a conventional example. FIG. 3 is a side view of an articulated robot, and FIG. 4 is a view showing a connecting portion between an upper arm or forearm drive shaft and a drive motor. FIG.

In FIG. 3, reference numeral 1 denotes an upper arm, which is rotatably attached to an upper end portion of a turning shaft 4 on a base 3 installed on a floor surface 2 about a turning shaft 5. Reference numeral 6 denotes a forearm, which is attached so as to be rotatable about a top rotation shaft 7 of the upper arm 1. Reference numeral 8 denotes an arm projecting from the swivel shaft 4, and a tip 9 of the arm 8 rotates a drive device 10 for the upper arm 1 and a drive device 11 for the forearm 6 provided in parallel with the drive device 10. It is movably supported. Reference numeral 12 denotes an arm whose one end rotates integrally with the upper arm 1 via a rotation shaft 5, and the other end of the arm 12 is attached to a ball nut 14 screwed to a drive shaft 13 using a ball screw.
It is rotatably connected via 15. Reference numeral 16 denotes an arm having one end rotatably attached to the rotating shaft 5, and the other end of the arm 16 is attached to a ball nut 18 screwed to a drive shaft 17 using a ball screw of the forearm drive device 11. It is rotatably connected via 19. Reference numeral 20 denotes a connecting rod, one end of which is pivotably connected to the shaft 19 and the other end of which is pivotally connected to a shaft 21 provided on the forearm 6,
Both ends of the connecting rod 20, that is, the distance between the shaft 19 and the shaft 21 is made equal to the distance between the rotating shafts 5 and 7 which are both ends of the upper arm 1, and both ends of the arm 16, that is, the rotating shaft 5. The distance between the shaft 19 and the rotary shaft 7 provided on the forearm 6 is equal to the distance between the shaft 21 and the shaft 21.

In FIG. 4, the drive shaft 13 of the drive device 10 for the upper arm 1 is attached to the case 23 via a ball bearing 22, and the drive motor attached to the case 23 via a shaft joint 24.
It is connected to 25. 26 is a brake, 27 is a position detector,
28 is a lid of the case 23. Further, the drive device 11 for the forearm 6
Since the drive unit of 1 is completely the same, the description is omitted.

Next, the operation of the upper arm and the forearm of the robot configured as described above will be described. When the drive motor 25 of the drive device 10 for the upper arm 1 is driven to rotate the drive shaft 13, the drive shaft 13 is rotated.
The arm 12 rotates around the rotating shaft 5 via a ball nut 14 and a shaft 15 that are screwed together with the upper arm 1 that rotates together with the arm 12 around the rotating shaft 5. Turn to.

When the upper arm 1 is rotated about the rotation axis 5, the forearm 6 moves to the side 5 of the parallelogram formed by the rotation axes 7 and 5, and the axes 19 and 21.
Since 19 is fixed and the other adjacent ones of the sides 5 and 7 are rotated around the rotary shaft 5, the parallel movement is performed around the rotary shaft 5.

When the drive shaft 17 of the drive device 11 for the forearm 6 is driven and rotated, the ball nut 18 screwed onto the drive shaft 17, the shaft
The arm 16 rotatably attached to the rotating shaft 5 via 19 is rotated around the rotating shaft 5, and the shaft 19 and the connecting rod 2
0, the forearm 6 is rotated around the rotation shaft 7 via the shaft 21 provided on the forearm 6.

Therefore, when the arm 16 is rotated around the rotating shaft 5, one side 7,5 of the parallelogram formed by the rotating shafts 7 and 5 and the shafts 19 and 21 is formed.
Since the other adjacent sides 5 and 19 are fixed to rotate around the rotation shaft 5, the forearm 6 rotates about the rotation shaft 7.

In the articulated robot described above, when removing the drive motor of the drive device 10 for the upper arm 1 or the drive device 11 for the forearm 6, as shown in FIG. 3, the relative displacement between the upper arm 1 and the connecting rod 20 is changed. The first fixing plate 29 is attached so that the arm 16 does not move, and the second fixing plate 30 is attached so that the arm 16 does not rotate around the rotation axis 5.
Was fixed so that would not move.

D. Problems to be solved by the device The articulated robot shown in Fig. 3 can maintain any posture, but it has a brake attached to the drive motor, and the brake comes off when driving and the brake when stopping. This is because it locks and locks the drive shaft. Therefore, when the drive motor is removed for maintenance or the like, the brake attached to the drive motor is also removed.
That is, when the drive motor 25 shown in FIG. 4 is removed, the brake 26 is also removed together with the motor 25, so that there is no brake for the drive shaft 13. As described in the previous section based on FIG. 3, the upper arm 1 is driven by the drive shaft 13 via the ball nut 14, and the forearm 6 is driven by the drive shaft 17 via the ball nut 18. Since the coefficient of friction between the ball nut and the ball screw, which is the drive shaft, is extremely small and smaller than the crease angle (tan) of the ball screw, the drive shaft 13 is The drive shaft 17 is extremely dangerous because the load applied to the ball nut 18 by the forearm 6 rotates when the drive motor with brake is removed.

Therefore, in order to prevent danger when removing the drive motor, first, as shown in FIG. 3, the posture of the articulated robot is controlled so that the upper arm 1 is kept perpendicular to the floor surface 2, and the forearm 6 is placed on the floor surface. After making a fine adjustment to a posture in which the fixing plates 29 and 30 can be attached in parallel with 2, the fixing plates 20 and 30 are attached and fixed so that the upper arm 1 and the forearm 6 do not move.

E. Means for Solving the Problem In an arm drive shaft such as an upper arm or a forearm, a worm wheel is fitted in proximity to a connecting portion with a drive motor for driving the drive shaft, meshes with the worm wheel, and forms a case. Prepare a lid with a worm that can be manually rotated from the outside.

F. Action When removing the upper arm or forearm drive motor, remove the regular lid provided on the drive unit, attach a separately prepared lid, and install it on the worm wheel fitted to the drive shaft and the lid. Mesh with the warmed worm.

G. Embodiment FIG. 1 is a partially cutaway side view showing an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line ii in FIG. In addition,
3 and 4, the same parts are designated by the same reference numerals and the description thereof will be omitted. Also, the drive device 10 for the upper arm 1 and the drive device for the forearm 6
Since 11 has the same structure, the drive device 10 for the upper arm 1 will be described below.

In FIG. 1, 31 is a worm wheel fitted to the drive shaft 13 in the vicinity of the drive motor 25, and 32 is a lid provided on the case 23. A worm 34 that meshes with the worm wheel 31 is rotatably attached to the lid body 32 via a bearing 33, and the worm 34 has a worm winding angle.
The worm 34 is prevented from being rotated by the worm wheel 31 by making it smaller than the division angle of the friction coefficient of the meshing portion between 31 and the worm 34. Also warm 34
The one end 35 that penetrates the bearing 33 has a rectangular cross section so that one end of a rotary handle (not shown) can be inserted and coupled through a through hole 36 formed in the case 23. Reference numeral 37 denotes an end lid, which is a commonly used lid, for example, the lid shown at 28 in FIG. 4 to prevent dust from entering in a normal state.

When removing the drive motor 25 for some reason such as maintenance and inspection, or the like, first remove the regular lid 28, attach the lid 32 instead, and after engaging the worm wheel 31 and the worm 34 with each other. The drive motor 25 is removed.

To attach the drive motor 25 to which the brake 26 is attached, first the drive motor 25 is attached, then the lid 32 is removed, and the regular lid 28 is attached to complete the work.

H. Effect of the invention Since the worm attached to the lid is not rotated by the worm wheel fitted to the drive shaft of the upper arm or the forearm, the upper motor or the forearm can be safely driven while keeping the arbitrary position. Can be removed and keep the upper arm perpendicular to the installation floor surface as in the conventional case and make fine adjustments by making the forearm parallel to the installation floor surface and make sure that the upper arm and forearm do not move. There is no need to install it.

Also, when the end cover is removed and one end of the rotary handle is inserted into the through hole provided in the case to connect with the uniaxial end that penetrates the bearing of the worm, rotate the worm and manually move the upper arm or forearm. Since it can be moved, it is easy to determine whether or not there is a cause on the drive motor side in the case of malfunction, and it is also possible to perform manual alignment or the like.

Further, if only the worm mounting portion is used as the lid, it is possible to remove and replace the shaft joint on the drive shaft shaft end side while keeping the worm wheel and the worm engaged with each other.

As described above, the present invention not only allows safe and easy attachment / detachment of the drive motor, but also manual adjustment,
It also has various practical effects in maintenance and inspection such as inspection and replacement of the shaft joint.

In the above embodiment, the case where the drive shaft is provided on both the upper arm drive shaft and the forearm drive shaft has been described, but it may be provided on only one drive shaft, and a regular lid and a lid body provided with a worm are used. Of course, the worm portion including the bearing may be detachably attached to the commonly used lid.

[Brief description of drawings]

FIG. 1 is a partially longitudinal side view showing an embodiment of the present invention, and FIG.
FIG. 1 is a sectional view taken along the line II in FIG. 1, FIGS. 3 and 4 are views showing a conventional example, and FIG. 3 is a side view of an articulated robot,
FIG. 4 is a partially longitudinal side view showing a connecting portion between the upper arm or forearm drive shaft and the drive motor. 13 …… upper arm drive shaft, 17 …… forearm drive shaft, 23 …… case,
24 …… Shaft joint, 25 …… Drive motor, 31 …… Worm wheel, 32 …… Lid, 34 …… Worm.

Claims (1)

[Scope of utility model registration request] 1. A worm wheel fitted in the arm drive shaft of an upper arm, a forearm, etc. of an articulated lock in the vicinity of a connecting portion with a drive motor for driving the drive shaft, and a worm wheel meshing with the worm wheel to form a case. An arm drive shaft lock device for an articulated robot, comprising: a lid provided with a worm that can be manually rotated from the outside.