CN1754650B - Fastener device - Google Patents

Abstract

A thread-fastening device is provided, which has a clamp for holding an internal hexagonal bolt and can be freely installed and removed by engaging with a sleeve of the corresponding bolt size. By combining with an industrial robot, its operating range can be expanded. This fastening device can install and remove fastening units for fastening components, and can fasten multiple different types of fastening components using a single nut wrench. It includes: a first drive unit that causes the fastening unit to move linearly in the direction of its rotation axis; a clamp for holding the fastening component; and a second drive unit that drives the clamp.

Description

fastening device

technical field

The invention relates to a fastening device for fastening a fastening part, in particular to a fastening device capable of replacing a fastening unit.

Background technique

In the assembly line of industrial machinery, in order to automate various screw tightening operations of workpieces that are sequentially conveyed and have different shapes and tightening torques, a method that can be tightened with a single nut wrench has been proposed. Screw fastening device (for example, refer to Patent Document 1).

In Fig. 4, the screw fastening device 10 has a base 12, at the corner of the base 12, a longer upper guide rail 14a and side guide rails 14b are provided in a direction perpendicular to the drawing, and on the upper guide rail Between 14a and the side rail 14b, a long rack member 16 is provided in the arrow X direction.

An X-axis table 18 is supported on the upper guide rail 14a and the side guide rails 14b, and a first rotational drive source 20 such as a servo motor is fixed to the lower side of the X-axis table 18 . A pinion 24 is connected to a rotation shaft (not shown) of the first rotational drive source 20 via a gear train 22 , and the pinion 24 meshes with the rack member 16 . On the upper part of the X-axis table 18, a pair of guide rails 26a, 26b extending in the arrow Y direction intersecting with the arrow X direction are fixed, and a second rotational drive source 28 is provided between the guide rails 26a, 26b. A ball screw 30 is connected to the second rotational drive source 28 .

A Y-axis table 32 is placed on the guide rails 26a and 26b, and a nut member (not shown) screwed to the ball screw 30 is provided on the lower portion of the Y-axis table 32 . On this Y-axis table 32, a pair of long guide rails 34a, 34b and a ball screw 36 to which a third rotational drive source 38 is connected are provided in the vertical direction (arrow Z direction). A Z-axis table 40 is supported on the guide rails 34 a and 34 b, and the Z-axis table 40 is freely moved up and down by the rotation of the ball screw 36 .

On the Z-axis table 40, a nut runner unit 42 and a sleeve unit replacement device 46 are provided. The replacement device 46 is used to selectively and automatically attach and detach the fastening sleeve portion 44 a or 44 b and 44 c (not shown) accommodated in predetermined positions to the nut runner portion 42 .

A workpiece pressing jig 120 and a workpiece positioning confirmation sensor 122 are attached to the support frame, and a workpiece conveying device 124 is disposed below the workpiece pressing jig 120 and the workpiece positioning confirmation sensor 122 . The workpiece W is sequentially conveyed by the workpiece conveying device 124 while being placed on the pallet 126 .

Next, related operations will be described. The workpiece W is conveyed by the workpiece conveying device 124 in a state where a plurality of screws are provided in the previous process, and stops at a predetermined screw fastening position. Then, after the workpiece W is positioned and held at a predetermined position by the workpiece pressing jig 120 and the workpiece positioning confirmation sensor 122, the first to third rotational drive sources 20, 28, and 38 constituting the screw fastening device 10 are selectively driven.

When the first rotational drive source 20 is driven, the pinion 24 is rotated by the gear train 22 , and the X-axis table 18 is moved by the pinion 24 and the rack member 16 . Then, when the second rotational drive source 28 is driven, the ball screw 30 rotates, and the Y-axis table 32 moves in the arrow Y direction. In addition, when the third rotational drive source 38 is driven, the Z-axis table 40 moves in the arrow Z direction via the ball screw 36 . Thereby, a screw provided on the workpiece W can be fitted into an engaging hole provided in the sleeve part 44 a attached to the nut runner part 42 .

Therefore, when the rotation drive source 55 is driven to rotate the rotation shaft 56 of the nut runner part 42, the sleeve part 44a rotates. Therefore, the screws of the workpiece W are tightened, and when the tightening torque reaches a predetermined value or more, the drive of the rotary drive source 55 is stopped by a torque detector (not shown) or the like.

[Patent Document 1] Japanese Patent No. 2588677 (pages 2-5, Figure 3)

Since the existing screw fastening device does not have a screw holding mechanism, it is necessary to set the screw on the workpiece W in advance. In addition, since the reachable range of the sleeve part is narrow, only one side of the workpiece W can be fastened. In order to fasten the opposite side and upper surface, it is necessary to change the orientation of the workpiece W by some method. Therefore, the existing screw fastening The device operation efficiency is not good.

Contents of the invention

The present invention is proposed in view of these problems, and its purpose is to provide a threaded fastening device, which has the following characteristics: it has the function of holding the screw, and can freely attach and detach the fastening unit corresponding to the size of the bolt; Combining with a robot manipulator that can fasten in any position allows a wide range of work.

In order to solve the above-mentioned problems, the present invention is structured as follows.

According to the first aspect of the present invention, the fastening device has a nut wrench, a transmission shaft and a fastening unit, the transmission shaft is connected to the output shaft of the nut wrench, and the above fastening unit is driven by the nut wrench to rotate and fasten the fastening parts , and the above-mentioned fastening unit can be assembled and disassembled, and a plurality of different types of fastening parts can be fastened by a single above-mentioned nut wrench, and it is characterized in that it has: a sleeve, which is engaged with the transmission shaft, and is rotated from the transmission shaft Moment, can move linearly in the direction of the rotation axis relative to the transmission shaft; the first drive unit for linearly moving the sleeve in the direction of the rotation axis; the second drive unit; and the third drive unit for attaching and detaching the fastening unit, The fastening unit includes: a jig that is opened and closed by the second drive unit to hold and release the fastening member; a joint that engages with the sleeve; and a fastening head that rotates and linearly moves the sleeve. Passed to the fastening head through the above-mentioned joint.

A second aspect of the present invention is characterized in that the jig is constituted by two movable claws, and the fastening member is gripped by opening and closing of the movable claws.

A third aspect of the present invention is characterized in that the first driving means is an air cylinder.

A fourth aspect of the present invention is characterized in that the second driving means is an air cylinder.

A fifth aspect of the present invention is characterized in that the fastening member is a hexagon socket head cap bolt.

A sixth aspect of the present invention is characterized in that the fastening device according to any one of the first to fifth aspects is attached to an arm tip of an industrial robot.

The first to fifth aspects of the present invention can provide a fastening device that has a jig and can attach and detach a fastening unit, so that it can be applied to various types and sizes of bolts such as hexagon socket head bolts that are difficult to hold in position.

In addition, the sixth aspect can provide an industrial robot, wherein each fastening device is mounted on the front end of the arm of the industrial robot, so that the fastening work can be automated in a wide range of work, and only by modifying the fastening position The teaching points can be flexibly matched.

Description of drawings

Fig. 1 is a transverse sectional view and a longitudinal sectional view showing a fastening device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a joined state of the second bracket 221 and the second air cylinder 220 .

Fig. 3 is a cross-sectional view showing a detached tip tool.

Fig. 4 is a side view of a conventional fastening device.

Label description

201 nut wrench; 202 base; 203 supervisor;

204 drive shaft; 205 sleeve; 206 connector;

207 fastening head (bit); 208 fixture; 220 the second cylinder;

221 2nd bracket; 230 1st cylinder; 232 1st bracket;

233 slider; 235 bearing; 236 second sleeve;

237 steel ball; 238 the first casing; 239 steel ball;

304 connecting pipe; 305 fixture bracket; 306 rotating shaft;

307 connecting rod; 330 3rd cylinder; 331 3rd bracket;

335 front tool seat; 336 clearance slot

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Example 1)

1( a ) is a cross-sectional view of the fastening device, showing a state in which the first air cylinder 230 is driven to extend, the fastening head 207 (fastening unit) is moved toward the front end of the device, and the clamp 208 is opened. FIG. 1( b ) is a longitudinal sectional view of the fastening device, showing a state in which the first air cylinder 230 is driven to shrink, so that the fastening head 207 retreats and the clamp 208 is closed.

The fastening device has: a rotation and linear drive mechanism for a fastening head 207 for fastening a screw; an opening and closing mechanism for a jig 208 for holding a nut; and a loading and unloading mechanism at the front end of the device. Each structure will be described below.

First, the configuration of the rotation and linear drive mechanism of the fastening head 207 will be described. In the figure, 201 denotes a nut runner, which is fixed to a base 202 with unshown bolts, and the base 202 is attached to an arm tip (not shown) of an industrial robot having various degrees of freedom. 203 represents the main pipe, which is fixed on the base 202 . 204 represents a transmission shaft, which is connected to the output shaft of the nut wrench 201 and runs through the main pipe 203 coaxially. The transmission shaft 204 is engaged with a sleeve 205 to transmit rotational torque, and the sleeve 205 is formed of a polygonal column or a spline so as to slide axially and move linearly.

The sleeve 205 is joined to a slider 233 via a bearing 235 , and the slider 233 is fixed to a first bracket 232 passing through a slot provided on the outer circumference of the main tube 203 . The first bracket 232 is fixed to the piston rod extending from the first air cylinder 230 (first driving unit) fixed on the base 202, and the sleeve 205 can be rotated during the rotation by making the first air cylinder 230 stretch and expand. It is also possible to move linearly in the axial direction. In addition, the sleeve 205 has a polygonal section or a spline whose inner diameter fits the propeller shaft 204 at one end, and a cylindrical inner diameter whose other end fits with the joint 206 . A through hole for holding a steel ball 239 is formed on the outer circumference of the sleeve 205 at the portion fitted with the joint 206 . The cylindrical wall thickness of the through hole portion is smaller than the outer diameter of the steel ball 239 . Therefore, the steel ball 239 arranged in the through hole always protrudes on the inner or outer wall side of the cylinder. A circular groove having the same curvature as the outer diameter of the steel ball 239 is provided on the cylindrical outer circumference of the fitting portion of the joint 206 with the sleeve 205 , and the position of the circular groove is arranged to coincide with the above-mentioned through hole of the sleeve 205 . The depth of the circular groove is formed to be equal to the protrusion dimension of the steel ball 239 described above. In addition, the first bushing 238 is pushed toward the front end of the rotating shaft by a compression coil spring (not shown), and normally the restraining steel ball 239 protrudes toward the outer peripheral side. That is, the steel ball 239 protruding radially inward is accommodated in the circular groove of the sleeve 205 , whereby the joint 206 and the sleeve 205 are engaged. 207 denotes a fastening head for a fastening bolt (not shown), which is engaged on the sleeve 205 .

Next, the configuration of the opening and closing mechanism of the clip 208 will be described. In the figure, 335 represents a front-end tool seat, which is engaged on the main pipe 203 by means of the action of the steel ball 237 and the second sleeve 236 for use. In addition, a jig bracket 305 is fixed at the front end. 208 is a jig composed of two movable claws, and each movable claw can rotate around a rotation shaft 306 provided on the jig bracket 305 . The inside of the movable claw is formed in a cylindrical (pocket) shape so as not to interfere with the head of the hexagon socket head cap bolt when closing the jig 208 . 220 is a 2nd air cylinder (2nd drive unit), and it is fixed to the main pipe 203. 221 is a second bracket, and the piston rod of the second air cylinder 220 is engaged in a state of being caught in a notch provided in the second bracket 221, and is detachable. FIG. 2 is a plan view showing the joined state of the second bracket 221 and the second air cylinder 220 . As shown in the figure, the second bracket 221 and the second air cylinder 220 can be disengaged by rotating the piston rod around the rotation axis. 304 is a connecting pipe, which is fixed to the second bracket 221 . The connection pipe 304 is configured to be able to slide axially with respect to the main pipe 203 and to be able to move linearly. In addition, a set of link rods 307 are respectively rotatably joined to the front end of the connecting pipe 304, and the other end of the link rod 307 is rotatably joined to one end of the movable claw.

Finally, the structure of the attaching and detaching mechanism of the tip tool will be described. The device front end portion (hereinafter referred to as "tip tool") of the fastening device is detachable. Figure 3 shows the detached front-end tool.

In FIG. 1 , 330 is a third air cylinder (third drive unit), and a piston rod is joined to a third bracket 331 . 236 is a second sleeve, which is joined to the piston rod of the third air cylinder 330 via the third bracket 331 . That is, the second sleeve is linearly moved in the axial direction by the drive of the third air cylinder. 237 is a steel ball accommodated in the holding hole provided in the main pipe 203 . The movement of the second sleeve 236 in the axial direction prevents the held steel ball 237 from flying out toward the outer peripheral side. That is, when the second sleeve 236 is pushed down, the steel ball 237 is constrained to protrude radially inward. On the other hand, when the second sleeve 236 is pulled up, the steel ball 237 is in a free state and does not protrude radially inward. When the screw fastening operation is performed, the third air cylinder is extended to press the second bushing 236, so the steel ball 237 protrudes radially inward. Accordingly, the steel ball 237 is fitted into a circular groove provided in the tip tool holder 335 , and the tip tool holder 335 is joined to the main tube 203 .

The biggest difference between the present invention and Patent Document 1 is that it has a jig 208 for holding the screw.

Hereinafter, the operation of the fastening device of the present invention having the above-mentioned structure will be described. First, the rotation of the fastening head 207 and the operation of the linear drive mechanism will be described.

When the piston rod of the first air cylinder expands and contracts, the expansion and contraction motion is transmitted to the sleeve 205 through the first bracket 232 and the slider 233 . Then, the expansion and contraction action transmitted to the sleeve 205 is transmitted to the fastening head 207 through the joint 206 . On the other hand, when the output shaft of the nut wrench 201 rotates, the rotation is transmitted to the transmission shaft 204, and then to the fastening head 207 through the sleeve 205 and the joint 206, so that the screw held on the clamp 208 is rotated. That is, the tightening head expands and contracts in accordance with the expansion and contraction of the piston rod of the first cylinder, and the screw can be tightened with a desired torque by the nut wrench 201 .

Next, the operation of the opening and closing mechanism of the clamp 208 will be described.

First, when the piston rod of the second air cylinder 220 expands and contracts, the expansion and contraction motion is transmitted to the connecting pipe 304 through the second bracket 221 . Then, the expansion and contraction motion transmitted to the connection pipe 304 is transmitted to the movable claw through the link 307, so the movable claw rotates around the rotation shaft 306, and as a result, the clamp 208 is opened and closed. That is, the jig 208 performs an opening and closing operation in conjunction with the telescopic operation of the second air cylinder 220, so that the screw can be gripped and released.

Next, the fastening operation based on the combined operation of the above-mentioned rotation of the fastening head 207, linear drive, and opening and closing of the jig 208 will be described.

Tightening work is carried out in the following order.

(1) The jig 208 is opened by extending the piston rod of the second air cylinder 220 .

(2) Shrink the piston rod of the second air cylinder 220, close the clamp 208, and hold the screws arranged in advance by the feeder.

(3) Move the held screw to the screw insertion part of the workpiece. The fastening device of the present invention is mounted on the front end of the arm of the robot, so it can perform fastening work in a wider range than conventional ones.

(4) The piston rod of the first air cylinder 230 is extended, and the fastening head 207 is extended to the held screw.

(5) The jig 208 is opened by extending the piston rod of the second air cylinder 220 .

(6) Since the extension force of the first air cylinder 230 acts on the fastening head 207, the fastening head 207 advances while pressing the screw until the screw tip reaches the tap portion.

(7) Drive the nut wrench 201 to tighten the screw with a desired torque.

Finally, the separation operation of the front tool will be described.

The separation operation of the tip tool is performed in order.

(1) The first bushing 238 is pushed toward the front end of the rotation shaft by a compression coil spring (not shown), and if the first bushing 238 is pushed against the pressing force of the compression coil spring, The front end of the steel ball is pressed against the support frame (not shown), and the steel ball retreats into the clearance groove 336 of the sleeve 238, and the engagement of the joint 206 is released.

(2) The third air cylinder 330 is contracted, and the second sleeve 236 is lifted up, whereby the steel ball 237 loses its restraining force, and the engagement of the front end tool holder 335 is released.

(3) With the action of the robot, the fastening device (nut wrench side) is rotated around the rotation axis (arrow direction in FIG. 2 ), and the second cylinder piston rod is released from the second bracket 221, and the front end tool is completely separated.

In addition, regarding the installation of the tip tool, it is performed in the reverse order of the above procedure.

As described above, since it is possible to hold hexagon socket head bolts which are difficult to maintain in position, and to replace the fastening head by attaching and detaching the tip tool, it is possible to provide a fastening device independent of the type and size of the bolt. In addition, since the screw fastening device can be attached to the tip of the arm of the robot, it is possible to automate fastening work with a wide range of work.

By changing the shape of the grip portion of the jig 208 and the fastening head 207, it can be applied to all fastening members such as bolts.

Claims (6)

1. fastener, have nut spanner, power transmission shaft and fastening unit, above-mentioned power transmission shaft is connected on the output shaft of nut spanner, above-mentioned fastening unit drives rotation and fastening secure component by above-mentioned nut spanner, and above-mentioned fastening unit can load and unload, can utilize the fastening a plurality of different types of secure components of single above-mentioned nut spanner, it is characterized in that having:

Sleeve, it engages with described power transmission shaft, comes turning moment from the power transmission shaft transmission, can move as straight line in the rotating shaft direction with respect to power transmission shaft;

The 1st driver element that above-mentioned sleeve is moved as straight line in above-mentioned rotating shaft direction;

The 2nd driver element; And

Load and unload the 3rd driver element of above-mentioned fastening unit,

Above-mentioned fastening unit has:

Anchor clamps are controlled this anchor clamps on-off action and are discharged above-mentioned secure component by above-mentioned the 2nd driver element;

Joint, it engages with above-mentioned sleeve; And

Fastener head, the rotation of above-mentioned sleeve and straight line move through above-mentioned joint and pass to this fastener head.

2. fastener according to claim 1 is characterized in that, above-mentioned anchor clamps are made of two movable pawls, and control secure component by the on-off action of above-mentioned movable pawl.

3. fastener according to claim 1 is characterized in that the 1st driver element is a cylinder.

4. fastener according to claim 1 is characterized in that the 2nd driver element is a cylinder.

5. fastener according to claim 1 is characterized in that described secure component is a hexagon socket head cap screw.

6. an industrial robot is characterized in that,

This industrial robot is equipped with each described fastener in the claim 1 to 5 at the arm front end.

Images