JPH0691553A - Bolt fastening device - Google Patents

Abstract

PURPOSE:To provide a bolt fastening device by which a bolt supplied from a bolt feeder and the like can be fastened reliably while holding it in a proper position and work can be carried out even at a comparatively narrow place. CONSTITUTION:At least three gripping claws 11 to grip a head of a bolt 10 are supported pivotally on the opening tip of a barrel 2 so as to be capable of swinging in an inward and outward direction, and are energized inside by means of a spring, and a lock cylinder 13 is fitted around the outer periphery in the tip vicinity of the barrel so as to be slidable in a lengthwise direction. A holding part is arranged in the lock cylinder 13 so as to hold the respective gripping claws 11 in a lock condition from outside when the lock cylinder slides in the tail end direction of the barrel, and a piston rod of a fluid pressure cylinder 18 fixed to a main body frame 1 is connected to the lock cylinder 13 through a connecting member 19 and a bearing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bolt tightening device which is used by being connected to a bolt feeder or the like for supplying a bolt and which inserts the supplied bolt into a predetermined screw hole for tightening.

[0002]

2. Description of the Related Art As a bolt tightening device of this type, an impact wrench having a structure described in Japanese Utility Model Publication No. 58-45011 has been known.

In this impact wrench, a socket shaft is arranged in a cylinder shaft so as to be able to move forward and backward, a grip claw for gripping a bolt is provided at a tip end portion of the cylinder shaft, and a bolt supply passage is obliquely inclined above the cylinder shaft. And a bolt feeder is connected to the bolt supply passage through a pipe or the like.

In this impact wrench, the bolt fed from the bolt feeder is advanced from the bolt supply passage to the tip of the cylinder shaft, and while being held by the gripping claws, the socket shaft is moved forward to move the tip of the socket shaft. Fit it on the bolt head,
Tighten the bolts by rotating the socket shaft.

However, this conventional impact wrench is
When the bolt is supplied into the cylinder shaft, it obliquely enters the cylinder shaft from the bolt supply passage that is inclined and connected to the upper part, and changes its posture in the cylinder shaft in the axial direction, that is, horizontally. Due to the structure that advances to, it is easy for a bolt that obliquely enters the cylinder shaft to go to the tip of the cylinder shaft while keeping it obliquely.In that case, the bolt cannot enter the central hole of the grip claw and inside the cylinder shaft There was a problem that the bolt was easily clogged.

[0006] In particular, when a bolt with a washer, which is often used in an automatic assembly process or the like, is used in such an impact wrench, there is a problem that the washer is apt to be caught in the cylinder shaft and is more likely to be clogged.

Therefore, the applicant of the present invention has filed Japanese Patent Application Laid-Open No. 4-1765.
In Japanese Patent Laid-Open No. 72-72, a linear tubular barrel is rotatably supported by a body frame via a bearing, a driving motor is linked to the barrel, and a supply hose for supplying a bolt to a distal end of the barrel is provided. Three gripping claws for gripping the bolt head are rotatably supported at the tip of the barrel opening, and a lock tube is fitted on the outer circumference near the tip of the barrel so that it can slide in the longitudinal direction. When the lock cylinder slides in the direction of the tip of the barrel, a steel ball that presses the gripping claws inward is held rotatably on the gripping claws and fixed to the body frame. A bolt tightening device having a structure in which a piston rod of a fluid pressure cylinder is connected to a lock cylinder via a connecting member is proposed.

[0008]

However, this bolt tightening device has a structure in which the catcher for holding the screw portion of the bolt protruding from the tip of the barrel is connected to the connecting member via the parallelogram link. Since the parallelogram link is prone to malfunction, and the parallelogram link projects to the bottom of the main body, if the bolt installation location is narrow, this projection may interfere and make it unusable. was there.

The present invention has been made to solve the above-mentioned problems, and holds bolts supplied from a bolt feeder or the like at an appropriate position so that the bolts that are continuously supplied can be securely held without clogging. It is an object of the present invention to provide a bolt tightening device that can be tightened on a screw and can perform work even in a relatively narrow place.

[0010]

In order to achieve the above object, in the bolt tightening device of the present invention, a linear cylindrical barrel is rotatably supported by a body frame via a bearing, and the barrel is driven. Motor is linked, a supply hose for supplying a bolt is connected to the distal end of the barrel, and at least three gripping claws that grip the head of the bolt are swingable inward and outward at the opening end of the barrel. It is axially supported and urged inward by a spring, and a lock cylinder is externally fitted to the outer periphery near the tip of the barrel so as to be slidable in the longitudinal direction.
When the lock cylinder slides toward the distal end of the barrel, a holding portion is provided for holding each of the gripping claws in a locked state from the outside,
The piston rod of the fluid pressure cylinder fixed to the main body frame is connected to the lock cylinder via the connecting member and the bearing, and the lock cylinder has a plurality of holding claws to hold the screw part of the bolt supplied through the barrel. When the fluid pressure cylinder is pivotally supported inward and outward, and the fluid pressure cylinder pulls back its piston rod, the lock cylinder retracts to separate the holding claw from the bolt, and the holding part of the lock cylinder holds the grip claw. Configured to lock.

[0011]

In this bolt tightening device, when the fluid pressure cylinder is pushed out, the lock cylinder is located at the tip side and the gripping pawl can be opened against the spring force. Is in a state capable of holding the screw part of.

The bolt supplied through the supply hose is
The threaded portion enters the barrel, the threaded portion projects from the tip of the barrel and is supported by the holding claw, and the head of the bolt fits inside the gripping claw so as to push it open and is gripped there.

At this time, since the bolt passes through the barrel having a straight cylindrical shape, and the screw portion and the head are grasped as they are by the grasping pawl and the retaining pawl pivotally supported on the barrel tip, the posture of the bolt may be inclined. Securely held at the tip of the barrel without clogging.

Next, when the piston rod of the fluid pressure cylinder is pulled back, the lock cylinder retreats to a predetermined position on the barrel via the connecting member, whereby the holding claw of the lock cylinder separates from the bolt and the lock cylinder. The holding portion locks the gripping claws at the tip of the barrel from the outside to be in a gripping state, and the head of the bolt is locked by the gripping claws.

Then, the gripped bolt is aligned with the bolt tightening portion of the structure, the motor is started to rotationally drive the barrel, and the bolt is screwed and tightened.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of the bolt tightening device, FIG. 2 is a front view of the device, and FIGS. 3 and 4 are transverse sectional views thereof.

Reference numeral 1 denotes a main body frame. A front cover 1a is fixed to a front portion of the main body frame 1, a rear cover 1b is fixed to a rear portion of the main body frame 1, and a linear cylindrical barrel 2 is provided at an upper portion of the main body frame 1 with a ball bearing 3 It is horizontally supported rotatably via. A supply hose 4 of a bolt having a hose socket 4a at its tip is detachably connected to the end of the barrel 2. The inner diameters of the supply hose 4 and the barrel 2 are substantially the same,
The washer bolt 10 can be easily passed in the axial direction.

Further, a motor (air motor or electric motor) 6 is horizontally fixed to the lower side of the main body frame 1 through a bracket 5, and its rotation axis is a gear wheel 7, 8.
The barrel 2 is rotated by the rotation of the motor 6. When the operator grips and uses it, a handle part (not shown) is attached to the rear part of the bracket 5, and when it is used by attaching it to an assembly robot or the like, this device is fixed to the arm or the like via the bracket 5. It

The barrel 2 is formed as shown in FIG. 6, and three flat cutouts 2b into which a distal end portion 16a of a holding claw 16 described later slidably enters are formed in an intermediate outer peripheral portion thereof in the circumferential direction. Are formed at equal intervals in the axial direction. In addition, three slits 2a are axially formed at equal intervals in the circumferential direction at the tip of the barrel 2 that opens, and the bolts 10 are provided in each slit 2a.
A grip claw 11 for gripping the head is pivotally supported inward and outward via a shaft 12. The three grip claws 11 are about 1
The holding claws 11 are arranged at intervals of 20 degrees, and the recesses 11a into which the bolt heads are fitted are formed inside the tips of the gripping claws 11.
An inclined portion 11b is provided at the end of 1.

On the other hand, the steel ball 1 is placed in the groove behind the slit 2a.
4 and the coil spring 9 are arranged, the steel ball 14 contacts the inclined portion 11b of the grip claw 11, and the coil spring 9 pushes the steel ball 14, so that the grip claw 11 pushes its tip recess 11a inward. It is constantly urged to hold the gripped state.

Further, the guide cylinder 15 is fixed to the middle outer peripheral portion of the barrel 2 with screws, and the lock cylinder 13 is slidably fitted to the outer periphery of the barrel 2 near the tip end thereof by being guided by the guide cylinder 15. It The lock cylinder 13 is formed as shown in FIG. 5, and has three slits 13a on its outer peripheral portion.
Are formed in the axial direction at equal intervals in the circumferential direction, and each slit 1
A holding claw 16 for holding the threaded portion of the bolt 10 protruding from the tip of the barrel 2 and a washer is pivotally supported inward and outward by a shaft 17 in the inside 3a.

An end portion 16a of the holding claw 16 is formed so as to project inward, and the end portion 16a is slidably inserted into the flat notch 2b of the barrel 2. Therefore, when the lock cylinder 13 is retracted as shown in FIG. 7, the holding claws 16 enter the slits 13a, and as shown in FIG.
3 is moved forward, its end 16a is flat cutout 2b.
Is pushed by the end of the holding claw 16 and enters the front part of the barrel 2 to hold the screw part of the bolt 10 and the washer.

Further, as shown in FIG. 7, the inner tip portion of the lock tube 13 has a tubular shape that holds the holding claw 11 of the barrel 2 in contact with the holding claw 11 from the outer periphery when the lock tube 13 retracts. A holding portion 13b is provided.

On the other hand, the front cover 1 of the body frame 1
A fluid pressure cylinder 18 is fixed to the front part of a with its piston rod facing forward. The connecting member 19 is fixed to the tip of the piston rod of the fluid pressure cylinder 18.

The inner race of the ball bearing 20 is fixed to the outer periphery of the base of the lock cylinder 13, and the connecting member 19 is connected to the outer race of the ball bearing 20. Reference numeral 21 is a holder for the ball bearing 20, and 22 is a nut for mounting the holder 21. By connecting the connecting member 19 to the lock cylinder 13 via the ball bearing 20, the piston rod of the fluid pressure cylinder 18 allows the rotation of the lock cylinder 13 to move the lock cylinder 13 in the axial direction.

Next, the operation of the bolt tightening device having the above structure will be described.

In the bolt tightening device, the supply hose 4 is connected to a bolt feeder (not shown) or the like, and when the operator manually uses it, the handle part attached to the bracket 5 is used by grasping it, and an automatic robot or the like is used. When used in an assembling apparatus, the bracket 5 is fixed to an arm such as a robot for use.

As shown in FIG. 1, the fluid pressure cylinder 18 is pushed out, that is, the lock cylinder 13 is pushed out to the tip, and the end portions 16a of the three holding claws 16 are flat notched portions 2a.
The front end of the holding claw 16 enters the position where the screw portion and the washer portion of the bolt 10 can be held, that is, the front of the barrel 2 by being engaged with the end portion of the. In this state, a bolt supply signal is sent to the bolt feeder or the like, and one bolt (bolt with washer or the like) 10 is supplied.

Then, the bolt 10 enters the barrel 2 through the supply hose 4, the tip of the bolt 10 projects from the tip opening of the barrel 2, and the head of the bolt 10 has three gripping claws 11.
Is inserted so as to push open against the biasing force of the coil spring 9 and fits into the recess 11a, and the bolt 10 is stopped at the position where the screw part and the washer enter the inside of the holding claw 16 in front thereof.

At this time, the hexagonal bolt head is securely held by the recesses 11a of the three gripping claws 11. The head of the bolt 10 is gripped by the grip claw 11, and the threaded portion and the washer are held by the holding claw 16. Therefore, the bolt 10 does not come off from the tip position regardless of the posture of the bolt tightening device.

Next, the piston rod of the fluid pressure cylinder 18 is pulled back to operate.

Then, the lock cylinder 1 is connected through the connecting member 19.
3 receives this force, the lock cylinder 13 is retracted to the position shown in FIG. 7 while being guided by the guide cylinder 15. As a result, as shown in FIG. 7, the three holding claws 16 are pushed by the tip of the barrel 2 and return to the inside of the slit 13a, and the holding part 13b of the lock tube 13 is fitted to the outer peripheral position of the gripping claw 11 and the three holding claws 16 are held. The gripping claw 11 is locked by the lock cylinder 13 in the gripped state of the bolt 10.

Then, the gripped bolt 10 is aligned with the bolt tightening portion of the structure, and the motor 6 is started. As a result, the barrel 2 is rotated via the gears 7 and 8, and the grip claws 11
The bolt 10 gripped by is rotated and screwed and tightened. The tightening force of the bolt is controlled by the motor controller, and when the tightening torque set in advance is reached, the motor 6
Stops.

In that state, if the tightening device is pulled toward you,
When the grip claw 11 is disengaged from the head of the bolt 10 and the fluid pressure cylinder 18 is pushed out, the lock cylinder 13 advances, and the tightening device supplies a new bolt 10 as shown in FIG. Return to a state where you can receive it.

FIG. 8 shows another embodiment. In this embodiment, the fluid pressure cylinder 38 is arranged so as to be fitted onto the outer peripheral portion of the barrel 32.

That is, in this tightening device, the barrel 32 is formed to be slightly longer than the barrel 2, a longer guide cylinder 35 is fitted on the outer periphery of the barrel 32, and a cylindrical fluid pressure cylinder is provided on the outer peripheral portion of the guide cylinder 35. 38 is fixedly attached to the front cover 1a side of the main body frame 1. The fluid pressure cylinder 38 is formed by inserting a cylindrical piston rod 39 having a cylindrical piston portion 39a into a cylinder case 36 having a cylinder head 37, and the cylinder case 36 has a fluid supply port and a discharge port. The seal member is provided on the sliding portion of the piston rod and the cylinder case 36, the sliding portion of the cylinder head 37 and the guide cylinder, and the like.

Piston rod 39 of fluid pressure cylinder 38
Extends forward and the ball bearing 20 is provided on the outer periphery of the base of the lock cylinder 13.
The cylindrical connecting holder 41 is fixed via the connecting member 41, and the end of the connecting holder 41 is connected to the tip of the piston rod 39 via the connecting member 42. The structure of the gripping claw 11 attached to the tip of the barrel 32, the structure of the lock cylinder 13 pivotally supporting the holding claw 16, and the structure of rotating the barrel 32 by the motor 6 are the same as those in the above-described embodiment. The same reference numerals are used to omit the description. The operation is also the same as in the above embodiment.

In the bolt tightening device having such a structure, since the fluid pressure cylinder 38 is arranged in a cylindrical shape on the outer peripheral portion of the barrel 32, the protruding portion is smaller than in the case of using a normal fluid pressure cylinder. , It is possible to tighten bolts even in narrower areas.

In the above embodiment, 12 in the circumferential direction.
Although the three gripping claws 11 are arranged at an interval of 0 degree, it is possible to arrange the six gripping claws at an interval of 60 degrees to hold the head of the hexagon bolt.

[0041]

As described above, according to the bolt tightening device of the present invention, since the bolt is linearly fed into the linear cylindrical barrel from the feed hose connected to the end portion thereof, the bolt is It goes straight to the tip of the barrel, and there is no problem that the supplied bolt is clogged in the cylinder shaft as in the past. Further, since the head of the supplied bolt is gripped by at least three gripping claws and the screw claws and washers are held by the holding claws of the lock cylinder, the bolt can be moved in any posture by moving the bolt tightening device. It can be held in an appropriate holding position and screwed into a predetermined place and tightened.

Further, unlike the conventional case, since the parallelogram link and the like do not project to the lower side near the tip of the barrel, the space near the tip of the barrel is widened, and the bolt is screwed in even when the mounting location of the bolt is narrow. Easy tightening work

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a bolt tightening device showing an embodiment of the present invention.

FIG. 2 is a front view thereof.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along the line IV-IV in FIG.

FIG. 5 is a perspective view of a lock cylinder.

FIG. 6 is a perspective view of a barrel.

FIG. 7 is an enlarged sectional view of the bolt tightening device in a grip lock state.

FIG. 8 is a vertical sectional view of a bolt tightening device according to another embodiment.

[Explanation of symbols]

 1-body frame, 2-barrel, 3-bearing, 4-supply hose, 6-motor, 10-bolt, 11-holding claw, 13-lock tube, 16-holding claw, 18-fluid pressure cylinder, 19-connection Element.

Claims (2)

[Claims] 1. A linear cylindrical barrel is rotatably supported by a body frame via a bearing, a driving motor is linked to the barrel, and a supply for supplying a bolt to a distal end of the barrel. A hose is connected, and at the opening end of the barrel, at least three gripping claws that hold the head of the bolt are pivotally supported inward and outward, and are urged inward by a spring. A lock cylinder is externally fitted to the outer periphery of the lock sleeve so as to be slidable in the longitudinal direction, and when the lock cylinder slides in the distal end direction of the barrel, the holding cylinder holds the gripping claws in a locked state from the outside. A piston rod of the fluid pressure cylinder fixed to the body frame is connected to the lock cylinder via a connecting member and a bearing, and a plurality of holding claws are supplied to the lock cylinder through the barrel. Bolt thread When the fluid pressure cylinder pulls back its piston rod, the holding cylinder is separated from the bolt when the fluid pressure cylinder pulls back its piston rod, and the holding cylinder moves away from the bolt. A bolt tightening device configured to lock the holding state of the holding claw by a holding portion. 2. The bolt tightening device according to claim 1, wherein the fluid pressure cylinder and the piston rod thereof are formed in a tubular shape and arranged on the outer peripheral portion of the barrel.