JPS6213155B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gripping device for an industrial robot. Although industrial robots have versatility up to the wrist, they lack the versatility of gripping tools, mainly fingers, and as a result, they are unable to respond to product diversification, and industrial robots lose their versatility. The current situation is that Various grippers have been tried for this purpose, but none have been able to provide versatility. In addition, attempts have been made to provide versatility, but many cylinders, electric motors, etc. as actuators and control devices to control them are required, and these are not suitable for practical use. The present invention has improved versatility by driving fingers with two joints using only one operating device, and by being able to use either two fingers or three fingers.

Generally, there are two methods of grasping with fingers: grasping by grasping the object from the periphery, and grasping by pinching it with the fingertips.
The present invention can be applied to any of them.

The invention will be explained by examples. FIG. 1 is an explanatory diagram of the present invention having one fixed finger and one movable finger.
The movable finger is composed of a fingertip 1 and a metacarpal 2. A shaft 3 is fixed to the base of the fingertip 1, and a pulley 4 is fixed to the shaft 3. Further, the shaft 3 is pivotally supported at the tip of the metahandle 2,
The fingertip 1 is rotatable around a shaft 3 at the tip of the metacarpal 2. A rotating shaft 8 is fixed to the base of the metacarpal 2, and is installed parallel to the shaft 3, and the palm 25
The metacarpal 2 is rotatably attached to one end of the palm 25, and the metacarpal 2 can rotate relative to the palm 25 about the rotation axis 8. The other end of the rotating shaft 8 is connected to an output shaft 31 of a differential gear mechanism 9, a pulley 7 is attached to the shaft 6, and the pulley 7 and the pulley 4 are connected by a transmission element 5 such as a belt or chain. , the rotation of the pulley 7 is transmitted to the pulley 4. It does not change the spirit of the present invention to use a link mechanism formed in a parallelogram instead of the rotation transmission mechanism composed of the pulleys 4 and 7 and transmission elements such as belts or chains. An input shaft 10 of the differential gear mechanism 9 is connected to a motor via a reduction gear (not shown).

The palm 25 is provided with a connecting member 24 that connects to the robot's wrist. A fixed finger 27 is fixed to the other end of the palm 25 so as to face the movable finger. A pin 42 provided at the tip of the metahandle 3 limits the opening of the fingertips, and a pin 43 provided at the upper end of the palm 25 limits the opening of the metahandle 3.

In FIG. 2, the fixed fingers in FIG. 1 are replaced with two fixed fingers, and the interval between the fixed fingers is made variable. 1st
The lower end of the palm with the movable fingers explained in the figure 2
1 accommodates fixed finger bases 18 and 19, and has a palm sinus 20 as a space. The base 18 of the fixed finger 11 and the base 19 of the fixed finger 12 slide within the palmar sinus 20 to make the distance between the fixed finger 11 and the fixed finger 12 variable.
The fixed finger bases 18 and 19 are provided with screw holes 16 and 17 in the direction of sliding of the fixed finger. The screw hole 16
and 17 are provided in a straight line, and pass through the adjustment rod 22, and the right-hand screw 14 is on the side of the screw hole 16, and the left-hand screw 15 is on the side of the screw hole 17. will be established. The adjustment rod 22 is rotated forward and backward by a handle or an electric motor (not shown) to adjust the distance between the fixed fingers 11 and 12.

FIG. 3 is a sectional view of the differential gear mechanism 9. The shaft 8 connected to the movable finger 2 becomes an output shaft 31, and the output shaft 31 is connected to a gear 33. The rotation shaft 7 of the pulley 6 becomes the output shaft 32, and the output shaft 32 becomes the gear 34.
The gears 34 and 33 have the same number of teeth and the same diameter. Output shafts 31 and 3 of the gears 33 and 34
2 is held by a member not shown so that it can rotate freely on the same line (this is referred to as a rotation line), and the pinion 35 and the pinion 36 mesh with the gears 33 and 34 at the same time. The small gears 35 and 36 have the same number of teeth, the same diameter, and are the same gears. Pinions 35 and 36 are connected to gears 33 and 3 by shafts 37 and 38.
4, the U-shaped member 41 can rotate freely.
It is attached to the upper side 39 and lower side 40 of. The pulley 6 is provided inside the U-shaped member, and the input shaft 10 is connected to the center of the U-shaped member 41. Due to the characteristics of the differential gear, the sum of the rotation angle of the output shaft 31 of the gear 33 and the rotation angle of the output shaft 32 of the gear 34 is equal to twice the rotation angle of the input shaft 10. Figures 1 and 2
The movable finger 2 and the fingertip 1 in the figure are in a position parallel to the fixed finger, or in a slightly open, linearly extended state, or in an open state.

When closed by grasping, it is sufficient to rotate the fixed finger 2 approximately 90 degrees from the open state, and the fingertip 1 rotates 180 degrees to 2.
It is sufficient to rotate the input shaft by 135°. The gripping operation can be performed within a range of rotation in which both sides 40 and 39 of the U-shaped member 41 connected to the input shaft 10 do not come into contact with the belt 5 placed on the pulley 6.

Moreover, it does not change the spirit of the present invention to appropriately select the ratio of the diameters of the pulley 6 and the pulley 4 to increase or decrease the rotation of the pulley 6 and to transmit the rotation to the pulley 4.
An electric motor (not shown) connected to the input shaft 10 is connected via a speed reducer and a torque limiter (not shown). It is also within the scope of the present invention to use a rotary DC solenoid instead of an electric motor, or to attach a pinion gear driven by a rod connected to the piston of the cylinder to the input shaft so that the input shaft can be rotated by the cylinder. It's not something to change.

The gripping motion will be explained with reference to FIG. Initially, the fingers are in an open position. The object to be grasped is placed between the fixed finger 27 and the movable finger. The input shaft 10 is rotated by an electric motor (not shown). Since neither the metahandle 2 nor the fingertips 1 are in contact with the object to be grasped, the output shafts 8 and 6 of the differential gear mechanism 9 simultaneously rotate in the same direction, and the metahandle 2 is connected to the output shaft 8. Rotate to close. At the same time, the shaft 6 rotates and the pulley 7
Since the rotation is transmitted to the pulley 4 via the belt 5, the fingertip 1 fixed to the pulley 4 rotates around the rotation axis 3 in a closed manner. Next, when the metahandle 2 comes into contact with the object to be grasped and the rotation of the metahandle 2 is hindered, due to the characteristics of the differential gear, the metahandle 2
Since the rotation of the output shaft 8 of the differential gear mechanism 9 is prevented, the output shaft 8 of the differential gear mechanism 9 does not rotate, and the rotation of the shaft 6 increases and continues to rotate, and the fingertip 1 rotates in the closing direction via the belt 5. When the fingertip 1 comes into contact with the object to be grasped and the object moves, and the force applied to the metahandle 2 decreases, rotation is again transmitted to the rotating shaft 8 by the differential gear mechanism 9, so that the metahandle 2 closes. Finger 27 rotates and fixes the object to be grasped
grasp from the surroundings using the metacarpal 2 and fingertips 1. If the fingertip 1 comes into contact with the object to be grasped first, the closing motion of the fingertip 1 will be hindered by the object to be grasped, and the output shaft 6 of the differential gear will slow down or stop its rotation, and the rotation of the shaft 8 will be accelerated. The closing motion of hand 2 continues at increased speed. The metahand 2 comes into contact with the object to be grasped, and the fingertips 1 and the metahand 2 press the object against the fixed finger, so that the object to be grasped is pressed against the fixed finger and the palm, so that the object to be grasped remains at a certain position. The movable fingers are kept in the same position and prevent the object from falling off. Attaching a jig suitable for the object to be grasped to the fixed finger does not change the spirit of the present invention.

When the fingertip 1 and the middle hand 2 come into pressure contact with the object to be grasped, the load on the input shaft 10 of the differential gear mechanism 9 becomes so large that rotation is stopped by a torque limiter (not shown) or an operating circuit of an electric motor.

The operation when releasing the grip will be described. The input shaft 10 of the differential gear mechanism 9 is rotated in the opposite direction by an electric motor. The two output shafts 6 and 8 of the differential gear mechanism rotate in the opposite direction to when gripping, and at the same time as the metahandle 2 is opened, the rotation of the pulley 6 is controlled by the belt 5.
is transmitted, and the fingertip 1 moves in the direction of opening. When the metahandle 2 comes into contact with the pin 43 and stops rotating, the rotating shaft 8 of the differential gear mechanism 9 stops rotating, and due to the characteristics of the differential gear, the fingertip 1 continues to open at an increased speed, The movable fingers come into contact with a pin 42 provided at the tip of the hand 2 and stop, and the movable fingers assume their initial open shape.

The operation shown in FIG. 2 will be explained. If the object to be gripped has a small diameter and is long, the fingertip 1 comes into contact with the fixed finger 27 and cannot be gripped using the method shown in FIG. Second
When the drive shaft 22 is rotated by a handle (not shown) or a motor, the screws 14 and 15 rotate in the same direction. 11 and 12
operate at equal distances from mutually close positions. Fixed finger bases 18 and 19 are palmar sinuses 20
The fixed fingers 11 and 12 are prevented from touching vertically and horizontally. When the metahandle 2 and the fingertip 1 are closed by an electric motor via the differential gear mechanism 9, the object to be grasped is thin, so the fingertip 1 fits between the fixed fingers 11 and 12, and the object to be grasped is moved between the fixed fingers 11 and 12. , the movable fingers 2, the palm 23, and part of the fingertips 1 can grip the object from the periphery. The gap between the fixed fingers 11 and 12 is adjusted in advance according to the object to be grasped before the gripping operation, and the gripping operation is performed after adjusting the gap between the fixed fingers.

Since the present invention uses a combination of fixed fingers, movable fingers, and fingertips to grasp the object, the fixed fingers and palm can always maintain the correct position and posture of the object to be grasped, and the movable fingers and fingertips can grasp the object. It is now possible to grasp changes in shape. The present invention greatly increases the versatility of the gripping operation, greatly contributing to the versatility of robots and automatic production systems for a variety of products.

[Brief explanation of the drawing]

Figure 1: An explanatory diagram of a gripping mechanism with one fixed finger and one movable finger. 1: fingertip, 2: metahandle, 3: shaft, 4: pulley,
5: Transmission element, 6: Shaft, 7: Pulley, 8: Rotating shaft, 9: Differential gear mechanism, 10: Input shaft, 24: Connection member, 25: Palm, 27: Fixed finger, 31: Output shaft, 42 , 43: Pin. Figure 2: An explanatory diagram of a grasping mechanism with two fixed fingers and a movable finger. 1: fingertip, 2: metahandle, 3: shaft, 4: pulley,
5: Transmission element, 6: Shaft, 7: Pulley, 8: Rotating shaft, 9: Differential gear mechanism, 10: Input shaft, 11,1
2: Fixed finger, 14, 15: Screw, 16, 17: Screw hole, 18, 19: Fixed finger base, 20: Palm sinus, 2
1: Lower end of palm, 22: Adjustment rod, 24: Connection member, 25: Palm, 27: Fixed finger, 31: Output shaft, 4
2,43: Pin. Figure 3: Cutaway diagram of the differential gear mechanism. 31, 32: Output shaft, 33, 34: Gear, 3
5, 36: Small gear, 37, 38: Shaft, 39: Upper side of U-shaped member, 40: Lower side of U-shaped member, 4
1: U-shaped member.

Claims (1)

[Claims] 1. A palm, one or more rod-shaped fixed fingers protruding perpendicularly to the palm at one end of the palm, or one or more rod-shaped fixed fingers arranged in parallel so that the interval can be adjusted, and the fixed fingers facing the fixed fingers. A movable finger consisting of a metacarpal that can be bent towards the metacarpal, a fingertip rotatably supported at the tip of the metacarpal and bent towards the metacarpal, and a rotation parallel to the palm that drives the metacarpal. a rotational axis parallel to the rotational axis of the metahandle, supported at the tip of the metahandle and fixed to the base of the fingertip;
A differential gear mechanism in which one output shaft is connected to the rotating shaft of the midhand and fixed to the palm, and a transmission element that transmits the rotation of the other output shaft of the differential gear mechanism to the rotating shaft that rotates the fingertips. and a rotary power source that drives the differential gear mechanism, and by being able to distribute rotation according to the load, it is possible to distribute the rotation according to the load, so that even after the fingertip or metahandle that first contacted the object to be grasped comes to rest, the grip remains intact. A grasping mechanism characterized by having a differential gear mechanism in which a fingertip or metahandle that does not come into contact with a grasped object continues to move and performs a grasping operation.