JPS59201731A - Screw fastening device - Google Patents

Abstract

PURPOSE:To prevent transmission of the screw driving torque to the support arm, in a screw fastening device using robot, by furnishing a damping member at the coupling part for the robot arm with the fastening device. CONSTITUTION:A robot arm 1 is located on a base 19. A member 9 is fitted coaxially on the head 18 of a bolt-shaped rotary shaft 16, and the surfaces 23a, 23b of a fixed shaft 23 are pinched by a pair of pinch fingers 13, 13. A motor is started, and the body 5a is sunk for a certain specified amount while a rotary shaft 6 is rotated, to cause fitting of the head 18 in said member 9. A cramping plate 21 is put in contact with the work to be processed 22 to provide solid fastening. The torque generated at the rotational driving part 5 is scarcely transmitted to the arm 1 side owing to a damping member 4, being applied certainly to the engagement part 11 with said fixed shaft 23.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a tightening device for tightening and loosening screws.

[Technical background of the invention and its problems]

Recently, with the advancement of robot technology, screw tightening work by robots has become popular. The screw tightening work by this robot can rotate the screw by moving the screw rotation drive unit to an arbitrary position on the screw portion. Therefore, it has the advantage of being able to easily adapt to changes in the screw tightening locations. However, on the other hand, the robot arm has low rigidity and torque is directly applied to the arm when rotating the screw, causing problems such as mydriasis and poor positioning. Therefore, there has been a need for a tightening device that is not affected by the torque generated when the screw is driven to rotate.

[Purpose of the invention]

It is an object of the present invention to provide a tightening device that can reduce the

[Summary of the invention]

A rotation drive part and a retaining part are attached to the tip of the support arm via a buffer member, and the rotation is transmitted from the rotation drive part to the object to be tightened to tighten and loosen the object to be tightened with respect to the base body, and the rotation The rotational torque generated by the drive part is applied to the retaining part that engages with a part of the base body.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the tightening device of this embodiment, in which a mounting portion (2) is attached to the tip of a robot arm (1). This mounting part (2) has two substrates (31, (31), and a rotation drive part (5) connected to the top of the front surface of the number part (2). The drive unit (5) includes a main body (5a) that houses a motor (not shown), a rotating shaft (6) that is connected to the motor and hangs downward, and a lower end of the rotating shaft (6). An elevating body (7) that can be freely raised and lowered in the axial direction by means of a key and a keyway (not shown) and is connected such that rotation of the shaft is impossible.゛A fitted body (9) connected to the lower end and having a hexagonal recess (8), and a fitted body (9) wrapped around the rotating shaft (6) between the main body (5a) and the elevating body (7). On the other hand, a retaining part (11) is attached to the front lower part of the attaching part (2). Support plate (12
1, and an engaging body α (a) which is placed horizontally on this support plate σ and has two clamping fingers (l (to) and (I3) shown in FIG. 2).

The operation of the tightening device of this embodiment configured as described above will now be described. What is being tightened in FIG. 1 is the rotating shaft αe, which forms part of a frang device α for automatic machine tools. A male screw portion α is formed at the lower end of the rotating shaft αe, and a hexagonal head u81 is connected to the upper end. And the male thread part (17
) is bored in the base 01 and is screwed into the internal threaded portion (20). A clamp plate (21) is rotatably mounted on the rotating shaft aO so as to be locked directly above the workpiece (221) by a swing mechanism (not shown). has a cylindrical fixed shaft (fangs,
It is fixed coaxially with the rotating shaft 06) and removably, with rotation around the shaft being restrained by a convex portion (not shown). Then, the fixed shaft (23) is cut out on both sides at an axially symmetrical position,
Mutually parallel clamping surfaces (23a) and (23b) are formed. Thus, when the workpiece (22) is screwed by screwing the rotating shaft (L6) onto the base α9), first,
Based on the program stored in advance in the arithmetic control unit of the robot, the arm (1) is moved to the base (right above 11), the recess (8) position of the fitting body (9) and the rotation axis (IQ head 08) position. are positioned so that they are coaxial, and the clamping surfaces (23a), (23b) of the fixed shaft G!■ are clamped by the clamping fingers (13), (13).
Start the motor, lower the main body (5a) by a predetermined amount while rotating the rotating shaft (6), and attach the head (18) to the fitting body (9).
Fit 1. In this state, the rotating shaft (6) is biased downward by the compression coil spring 00). Thus, H
The rotating shaft (6) rotates with a constant rotational torque, and the male thread part (
t7) Screw into the female screw part (2) and attach it to the rotating shaft (6
) goes down. Accordingly, the clamp plate (2I) is hardly transmitted to the workpiece yaw arm (1) side, but is applied to the engaging portion I that engages with the fixed shaft (c). Therefore, even if the rigidity of the arm (1) is low, the screw tightening/loosening work can be performed reliably, and the arm (1) can be moved to any desired screw mounting position.

Note that the clamping fingers (131, (131) of the retaining part ([1) are
Opening/closing (φ structure may be used to open and close, and it may be possible to respond to changes in the dimensions of the object to be secured. In this case, the gripping fingers (1,
(It is more effective to add an elastic body such as rubber to the inner surface of 13+.Also, the center of the engaging body θ may be moved up and down along the support plate U.Furthermore, the above embodiment example In the above, the rotation drive part (5) and the engagement part (Ill) are attached to the tip of the arm +11 of the robot, but they may also be attached to the support arm of a dedicated screw tightening machine.餘H shintai 1v = last name Iku τ - phase 7 transfer Tomida takuhi seven atsuma → ≠ fee - Ki 呵 Furthermore, in the above embodiment, tightening is performed by rotating the bolt head. However, the present invention can also be applied to a device in which the tightening work is performed by rotating a nut with a nut runner.

〔Effect of the invention〕

In the tightening device of the present invention, the rotational torque generated when performing tightening work with the rotation ratio μ11 parts is not transmitted to the support arm side that supports the rotational drive section. Therefore, even if the rigidity of the support arm is low, the screw tightening and loosening work can be performed reliably, so the support arm can be easily moved, and the screw tightening and loosening work can be performed at any position, for example, even if the rigidity of the support arm is low. This can also be done with small robots.

[Brief explanation of the drawing]

FIG. 1 is a side view of a tightening device according to an embodiment of the present invention, and FIG. 2 is a top view of a retaining portion. Iron tip (1): arm (support arm), (4): buffer member. (5) Two-rotation drive part, (lυ: engaging part, αe: rotating shaft (clamped body), H: pace (base body). Agent: Patent attorney Kensuke Chika (and one other person)

Claims (1)

[Scope of Claims] A tightening device for tightening screws of a to-be-tightened body to a base body, which includes a movable support arm, a movable support arm attached to the support arm, and transmitting rotation to the to-be-tightened body to a rotary drive unit that tightens and loosens screws with respect to the base body; a retaining unit that is integrally connected to the rotary drive unit and engages with a portion of the base body; and the support arm and the n? 1. A tightening device comprising: a buffer member inserted between a rolling drive section and a buffer member.