JPH0373405B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a hexagonal bolt tightening device that can grip hexagonal bolts of different sizes and screw them into screw holes as they are.

(Prior art) Conventionally, when parts are fastened using hexagonal bolts in automatic assembly work carried out by robots, etc., the hexagonal bolts are arranged in a parts feeder, etc., are grasped by a gripping device, and brought to the place where the screws are to be tightened. After dropping the hex bolt into the hole, fit the socket of the bolt runner into the hex head and tighten the bolt, or tighten the bolt temporarily by hand with the bolt runner automatically. A method was used to conclude the agreement.

However, in the above method, different work tools are used for setting the hexagonal bolt in the hole to be tightened and for tightening, which requires the use of multiple robots, which is expensive, and has the disadvantage of increasing the takt time. Ta. In particular, with the method of dropping a hexagonal bolt into a hole, the tightening direction was only upward, making it impossible to work from the side.

Furthermore, since the socket is fitted onto the head of the bolt for fastening, there is a problem in that it cannot accommodate hexagonal bolts of different sizes.

(Purpose) The purpose of the present invention is to provide an inexpensive device that can hold hexagonal bolts of different sizes with the same device, screw them into screw holes as they are, shorten the takt time of automatic assembly work by robots, etc., and tighten them in any direction. It is said that

(Structure) In order to achieve the above object, the present invention fixes a cam plate to the output shaft of a nut runner, fixes an elastic material to the inner surface of a collar fixed to the nut runner concentrically with the output shaft, and rotates it around the outer periphery of the cam plate. The boss part of the movably arranged base was fitted, and three swing pawl pins were fitted to the base at equal positions on a 120° circumference, and protruded from the middle part of the swing pawl. The pin is fitted into the cam groove of the cam plate so that the swing pawl can be opened and closed around the output shaft, and the swing pawl that presses and grips every other surface of hexagonal bolt heads of different sizes is elastic. It is characterized in that it rotates together with the rotating base while being braked by a material, and a hexagonal bolt is screwed into a screw hole. A detailed explanation will be given below based on examples. 1 A nut runner fixed to the working shaft of the robot, whose output shaft 2 has three degrees of freedom in the axial direction and in a plane perpendicular to the axial center depending on the robot's operation, and a disk-shaped cam plate 3 at the lower end. are fixed concentrically. A flange 4a of a collar 4 is fixed to a flange 1a on the lower surface of a nut runner 1, the collar 4 and an output shaft 2 are made concentric, and an elastic member 5 is fixed to the inner surface of the collar 4. 6 The upper boss portion 6 a of the base disposed on the outer periphery of the cam plate 3 fits into the elastic member 5 , is pivotally supported on the outer periphery of the cam plate 3 with a bearing 7 , and is attached to the lower flange 6 .
The shaft pins 8a of three swing pawls 8, which are arranged at equal positions on a 120° circumference, are rotatably fitted into the shaft pins b. Cam pin 8 protruding from the middle of each swing pawl 8
b fits into each cam groove 3a formed in the cam plate 3. The tip end portion 8c of each swing pawl 8 projects downward from the center hole of the lower flange 6b of the base 6.

Next, the effect will be explained. The movement of the robot positions the nut runner 1 coaxially with the hex bolt to be gripped. Next, Natsuto Runner 1
When the output shaft 2 of is rotated in the direction of the arrow in FIG. 3, the base 6 rotates relative to the cam plate 3 because the boss portion 6a is frictionally fitted to the elastic member 5 fixed to the collar 2. Since the cam pin 8b of the swing pawl 8 pivotally mounted on the base 6 is fitted into the cam groove 3a formed in the cam plate 3, the swing pawl 8 opens as shown by the solid line in FIG. Next, when the nut runner 1 is lowered and the output shaft 2 of the nut runner 1 is rotated in the opposite direction to the above-mentioned direction, the rocker 8 rotates in the closing direction as shown by the dashed line in FIG. Since the shaft pins 8a of the swinging claws 8 are arranged on the base 6 at equal intervals of 120°, the angles that the three swinging claws 8 make with each other are always
Since the angle is 60 degrees, it is equal to the angle formed by the adjacent surfaces of the heads 9a of the hexagonal bolts 9, and each swing pawl 8 allows hexagonal bolts 9 of different sizes to always align their centers within the range of its stroke. It can be grasped by hand. Next, the rotation of the output shaft 2 of the nut runner 1 is stopped and the nut runner is moved by the robot to the top of the screw hole where the nut runner is to be fastened. Next, the output shaft 2 of the nut runner 1 is rotated in the fastening direction and lowered in the axial direction. The degree of freedom in the rotational direction of the base 6 is restricted by the elastic member 5, but by applying a torque greater than the friction caused by the elastic member 5, the base 6 is rotated together with the swing pawl 8 that grips the hexagonal bolt 9. Therefore, the hexagonal bolt 9 can be continuously rotated in the direction of screwing it into the screw hole.

After fastening the hexagonal bolt 9 to the screw hole, the output shaft 2 of the nut runner 1 is rotated in the opposite direction, and the robot is moved to grasp the next hexagonal bolt. By repeating this operation, hexagonal bolts of different sizes can be gripped and fastened one after another into predetermined screw holes.

(Effects) According to the present invention, a cam plate is fixed to the output shaft of the nut runner, and an elastic material is fixed to the inner surface of the collar that is fixed to the nut runner concentrically with the output shaft, and is rotatably disposed around the outer periphery of the cam plate. Fit the boss part of the base, fit the three pins of the swing pawl to the base at equal positions on the 120° circumference, and connect the pins protruding from the middle part of the swing pawl to the front cam plate. is fitted into a cam groove of the cam groove, so that the swing pawl can be opened and closed around the output shaft,
The swinging pawl that presses and grips every other surface of hexagonal bolt heads of different sizes rotates with the rotating base while being braked by an elastic material, and screws the hexagonal bolt into the screw hole, so the same device can be used. Since the hexagonal bolts can be gripped and fastened, in automatic assembly work by robots, etc., the bolts can be transported and assembled by one robot, which increases the work speed and lowers the cost of the equipment.

Furthermore, since the bolt is held and tightened as it is, bolt tightening work can be performed in any direction. Moreover, since it can accommodate hexagonal bolts of different sizes, there is no need to change sockets etc. using ATC equipment, etc., and the center of the hexagonal orthogonal bolt is always the same, making robot teaching easier and creating a more flexible assembly system. be able to.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view of an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1... Nut runner, 2... Output shaft, 3...
Cam plate, 3a...Cam groove, 4...Color, 5...
Elastic member, 6... Base, 6a... Base boss portion, 6b... Base lower flange, 8... Rocking pawl, 8a... Rocking pawl shaft pin, 8b... Rocking pawl cam pin.

Claims (1)

[Claims] 1 Fix the cam plate to the output shaft of the nut runner,
An elastic material is fixed to the inner surface of the collar fixed to the nut runner concentrically with the output shaft, and the boss part of the base rotatably arranged around the outer periphery of the cam plate is fitted into the base.
Fit the pins of three swinging claws at equal positions on a 120° circumference, fit the pin protruding from the middle part of the swinging claw into the cam groove of the cam plate, and then The movable claw can be opened and closed around the output shaft, and the swinging claw, which presses and grips every other surface of hexagonal bolt heads of different sizes, rotates together with the rotating base while being braked by an elastic material, and the hexagonal bolt A hex bolt tightening device designed to screw into a screw hole.