JPH0621676Y2 - Robot with built-in shock absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a robot with a built-in shock absorber that absorbs variations in height when a work is inserted or taken out by fingers.

(Prior Art) FIG. 2 shows a robot for vertically rotating a finger in an insert molding system in which a work is inserted into a mold and a resin is molded around the work. 1 is the robot arm,
Reference numeral 2 denotes a tool shaft at its tip, which is attached by a spline to be vertically movable by rotary holders 5 and 6 which are rotatably supported by bearings 3 and 4. Reference numeral 7 denotes a tool shaft vertical movement motor fixed to the arm 1, which is interlocked with a ball screw 8 arranged in parallel with the tool shaft 2 by pulleys 9 and 10 and a belt 11, and the rotary holder 6 is driven by a belt 12 from a drive source (not shown). The rotation is transmitted by the pulley 13. A nut 14 screwed into the ball screw 8 and a tool shaft 2 at the upper end of the bearing 1
A dog 19 is fixed to an intermediate lower surface of a connecting rod 18 that connects a member 17 rotatably and vertically mounted integrally with each other via 5, 16 and a descending end sensor 20 is fixed on the arm 1 below the dog 19. ing. Reference numeral 21 is a finger detachably attached to the lower end of the tool shaft 2.

When inserting a workpiece or taking out a product, there are variations in the height of each mold (lower die) and variations in the amount of the product injected by the molding machine. In order to solve this problem, a shock absorber as shown in FIG. 3 has been conventionally considered.

That is, the holder disc 22 is fixed to the lower end of the tool shaft 2, the holder disc 23 is fixed to the upper ends of the fingers 21, and the shafts 26 and 27 are inserted into the slide bearings 24 and 25 fixed to the holder disc 22. Is fixed to the holder disc 22, and springs 28 and 29 are mounted on the outer circumferences of the shafts 26 and 27 between the slide bearings 24 and 25 and the holder disc.

(Problems to be solved by the invention) By the way, in the above conventional technology, the fingers themselves have a complicated structure, and when one robot is used as a general-purpose machine, it is necessary to replace the fingers depending on the work. Although it is common, there is a problem in that it is necessary to design a finger in which a cushioning mechanism is incorporated each time, which is disadvantageous in cost.

(Means for Solving Problems) The present invention is intended to solve the above problems, and a cylinder that moves up and down integrally with the tool shaft between the tool shaft and the tool shaft drive shaft, and a tool shaft drive shaft. A shock absorber consisting of a piston that moves up and down as a unit is installed, and the stroke between the dog and the descending end sensor integrated with the piston is lengthened by a certain amount compared to the sliding stroke in the finger up and down direction, and the intake and exhaust ports are installed in the cylinder. It is characterized in that the pressure is changed and the buffering force is changed according to the type of the work.

Hereinafter, the embodiment shown in FIG. 1 will be described in detail.
In the robot shown in FIG. 2, the cylinder 30 is fixed on the support plate 17a protruding rearward from the member 17, and the piston 31 is mounted so that it can slide up and down.
2 of the support plate 17a is projected downward from the through hole 17b of the support plate 17a, and is projected forward from a nut 14 screwed into the ball screw 8.
4a and the dog 33 are formed in the lower end.
Reference numerals 34 and 35 are intake / exhaust ports of the cylinder 30.

When the finger 21 reaches the descending end, the dog 33 is separated from the descending end sensor 20 by a certain distance.

Next, the operation will be described. The piston 31 is constantly pressurized from the port 35 with a pressure that does not compress the work. Then, the nut 14 that operates the tool vertical movement motor 7 is lowered, and the support plate 14a, the piston rod 32, the piston 31, the cylinder 30, the support plate 17a, and the tool shaft 2 are integrally lowered, and the finger 21 is moved to the lower end position. Even after reaching and contacting the work, the tool vertical movement motor 7 is further operated, the nut 14, the support plate 14a, and the piston rod 32 are integrally lowered, and the piston 31 is lowered in the stopped cylinder 30 and the dog 33 Comes into contact with the descending end sensor 20, and the tool vertical movement motor 7 stops. Therefore, the variation of the lower end of the finger 21 can be absorbed by the stroke of the piston 31.

By adjusting the air pressure from the intake / exhaust ports 34, 35 to the cylinder 30, the pressing force of the piston 31 can be adjusted, and the cushioning force is adjusted according to the hardness of the work.

(Effect) According to the present invention, between the tool shaft and the tool shaft drive shaft, a cushioning device including a cylinder that moves up and down integrally with the tool shaft and a piston that moves up and down integrally with the tool shaft drive shaft is provided, and a finger is provided. The stroke between the dog integrated with the piston and the descending end sensor is set to a predetermined amount longer than the sliding stroke in the vertical movement direction, and the intake and exhaust ports are provided in the cylinder, and the pressure is changed to provide a cushioning force according to the type of work. Since it is designed to be variable, the pressure of the cylinder can be variably adjusted according to the hardness of the work, and it is possible to prevent the work from being crushed or causing improper insertion, and the work insertion and product removal. In this case, it is possible to correct variations in the height of the mold (lower die) and variations in the amount of product injection by the molding machine with a small and simple finger. Wear. Further, the impact when reaching the descending end is not directly transmitted to the ball screw, and the durability is excellent.

Further, by providing the shock absorber on the tool shaft, the weight of the tip of the robot arm can be reduced, the arm turning speed can be increased, and the stop position accuracy can be improved.

[Brief description of drawings]

FIG. 1 is a front view of a main part of an embodiment of the present invention, and FIG. 2 is a front view of a main part of a conventional robot before the present invention.
The figure is a cutaway front view of a conventional shock absorber. 1 ... Arm 2 ... Tool shaft 7 ... Tool vertical movement motor 8 ... Ball screw 14 ... Nut, 14a ... Support plate 17 ... Member, 17a ... Support plate 20 ... Falling end sensor 30 ... Cylinder 31 ... Piston 32 ... Piston rod 33 ... Dog

Claims (1)

[Scope of utility model registration request] 1. A shock absorber comprising a tool shaft and a cylinder that moves up and down integrally with the tool shaft and a piston that moves up and down integrally with the tool shaft drive shaft is provided between the tool shaft and the tool shaft drive shaft. The stroke between the dog, which is integrated with the piston, and the descending end sensor is set to be a specified amount longer than the sliding stroke, and the cylinder is equipped with intake / exhaust ports so that the pressure can be changed and the cushioning force can be varied according to the type of work. The robot with built-in shock absorber.