JPH0276645A - Bolt fastening device - Google Patents

Abstract

PURPOSE:To have advance of bolt screwing in good performance even though the bolt is dislocated with respect to the bolt hole to a certain degree by allowing a resilient member to support a fastening means such as a nut runner, which rotates the bolt from below a work to be processed, and thereby providing a degree of freedom. CONSTITUTION:A piston rod 24 of a cylinder 22 is elongated to allow advancing of a nut runner 46 so as to locate a bolt fitted in a socket 82 right under the threaded hole in a work 92 to be processed, and another cylinder 34 is operated to retract a wedge 38 so as to provide proper response to a different type of work. Then a piston rod 52 of an elevating/sinking cylinder 50 is elongated to lift and nut runner 46 through a supporting rod 54 and a coupling part 48, followed by bolt insertion which can be performed without inclination because the socket 82 is supported resiliently by a spring 56, wherein eventual eccentricity to a certain degree can be offset by dislocation compensation to be given by deformation of a resilient ring 64, which shifts the nut runner 46 a little in the horizontal direction. Then rotation of a motor 44 is speed changed through a rotary shaft 66, drive shaft 70, driven shaft 74, gears 78, 80, and the socket 82 is rotated at a high speed, and when a specific torque is obtained, the motor 44 is stopped.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a bolt tightening device, and more particularly, it is capable of automatically and reliably tightening fastening members such as bolts from the underside of a workpiece. Moreover, the present invention relates to a bolt tightening device configured to be able to handle many types of workpieces.

[Background of the Invention] In recent years, automation of the assembly process of mechanical products has progressed, and work that previously relied on human power is now being performed without human intervention due to the development of various devices. The work of tightening bolts, etc. is no exception to this. For example, one example is the assembly of a torque converter in an automobile engine assembly process.

Generally, for a so-called vertical engine that is disposed parallel to the installation direction of a vehicle, a torque converter is assembled into the engine from above during assembly. However, in the case of a so-called horizontal engine installed in a direction perpendicular to the installation direction of the vehicle, the engine is reversed in the conveyor line, a torque converter is installed from above, and then the engine is reversed again to perform normal operation. A return to line assembly is underway. Therefore, the task of attaching a torque converter to a horizontally mounted engine is extremely complicated. Therefore, if it is possible to assemble the torque converter into the transverse engine from below, it is possible to omit at least the two steps of reversing the engine. In this case, the torque converter is set on the drive plate attached to the end of the engine's crankshaft, and screw holes are similarly drilled into the torque converter from below the holes drilled at equal intervals on the circumference of the drive plate. All you have to do is screw a bolt into it to integrate the two. However, in this assembly process, a worker must tighten each bolt from below using a ratchet wrench or a hand-held nut runner. Therefore, the work is complicated and requires a large number of personnel.

On the other hand, if you try to tighten such bolts in an automated process, you will have to accurately match the position of the bolt tightening device with the screw size of the engine and torque converter, and also adjust the position of the screw hole each time you tighten the bolt. It needs to change. However, in practice, it is difficult to accurately determine the location of the bolt tightening device and the thread size of the engine's torque converter, and as a result, the threads become galled when tightening the bolts, making it impossible to continue the work. There are concerns that.

[Object of the Invention] The present invention has been made in order to overcome the above-mentioned disadvantages, and the bolt position can be adjusted by supporting the tightening means such as a nut runner that rotates the bolt with an elastic member to give it a degree of freedom. It is an object of the present invention to provide a bolt tightening device that allows the bolt to be screwed in properly even if the bolt is slightly deviated from the position of the bolt hole.

[Means for Achieving the Object] In order to achieve the above object, the present invention provides a device for screwing a fastening member such as a bolt into a workpiece from below and tightening the workpiece, the device being connected to a first actuator. a main body that can move forward and backward in the horizontal direction; and a tightening means that is disposed in front of the main body and moves upward in the vertical direction under the driving action of a second actuator to tighten a bolt or the like against a workpiece. and a positioning adjustment means that can adjust the forward position of the tightening means to at least two positions.

[Embodiments] Next, preferred embodiments of the bolt tightening device according to the present invention will be described in detail with reference to the accompanying drawings.

1 and 2, reference numeral 10 designates a bolt tightening device according to the invention. This bolt tightening device 10 is installed on a pedestal 12, and is connected to a machine base 16 that is slidable along slide rails 14a and 14b laid on the base 12, and a flat cover 18 that is erected and fixed to this machine base 16. a main body part 19, a tightening mechanism part 20 disposed in front of the cover 18, and a feed cylinder 22 that moves these parts forward and backward.
including.

As shown in FIG. 2, the piston rod 24 of the feed cylinder 22 is connected to a connecting portion 28 of the cover 18 via a joint member 26. As shown in FIG. On the other hand, a work type switching cylinder 34 is supported at a predetermined position on the lower surface of the pedestal 12 by brackets 32a and 32b fixed to the mounting plate 30. This work type switching cylinder 34 is for adjusting the forward end position of the tightening mechanism 20, which is moved forward and backward by the feed cylinder 22, in accordance with the work.
A wedge 38 is attached to 6. In addition, the pedestal 12 includes
A displacement regulating member 40 is provided close to the wedge 38 of the work type switching cylinder 34. And machine 1
A stopper 42 is provided at the end of the wedge 3 of the displacement regulating member 40 or the work type switching cylinder 34.
8 comes into contact with the tip of this stopper 42 and the tightening mechanism part 2
Regulates the forward end position of 0.

Next, the tightening mechanism section 20 will be explained. This tightening mechanism section 20 includes a drive motor 44 as a rotational drive source, a nut runner 46 as a substantial tightening means in which a plurality of gears for transmitting the rotation of the drive motor 44 to a socket for rotating a bolt are stored. It includes a connecting portion 48 that is integral with the nut runner 46, and a lifting cylinder 50 that vertically displaces the nut runner 46 and the connecting portion w) 48. Lifting cylinder 5
A support rod 54 is connected to the piston rod 52 of No. 0 via a flange 53, and this support rod 54 is connected to the connecting portion 4.
The connecting portion 48 is supported through the elastic force of a balance spring 56 which is loosely fitted into the balance spring 8 and is wound around the lower end of the balance spring 56 and whose one end is seated on the flange 53. That is,
A play is provided so that the connecting portion 48 and the nut runner 46 can be vertically displaced with respect to the support rod 54. Further, as shown in FIG. 3, two guide rods 58 are inserted through the connecting portion 48, and an elastic ring 62 is inserted between each of the machine base 16, the upper plate 60, and the supporting end of the guide rod 5B.
．． 64 is interposed. These elastic rings62.64
As a result of the deformation, the guide rod 58 has play that allows it to be slightly displaced in the direction of the arrow, and therefore the connecting portion 48 and the nut runner 46 are allowed to be slightly displaced in the horizontal direction.

Next, the rotation shaft 66 of the drive motor 44 is connected to a drive shaft 70 via a joint 68. A spline 7 is provided at the tip of the drive shaft 7o so that the nut runner 46 can move up and down.
2 is engraved, and a nut runner 46 is attached to this spline 72.
The inner driven shaft 74 is coupled. A first gear 76 is fitted onto the driven shaft 74 . Further, the nut runner 46 includes a second gear 78 that meshes with the first gear 76 and a second gear 78 that meshes with the first gear 76 .
A third gear 80 meshing with the drive motor 8 is provided, and the rotation of the drive motor is changed to a high speed by the gear train consisting of the first gear 76, the second gear 78, and the third gear 80 (this embodiment 700 rpm), a configuration is adopted in which the speed is transmitted to the socket 82. Since the nut runner 46 tightens bolts from below the workpiece, the socket 82 is exposed at the upper end thereof. This socket 82 has a magnet 8 for holding the head of the bolt when it is fitted into the hexagonal hole of the socket 82.
4 is preferably buried.

The bolt tightening device according to the present invention is basically constructed as described above. Next, the bolt tightening device lO
As an application example, when assembling a torque converter as a workpiece to an engine, an automatic torque converter assembling system that automatically performs the work of tightening bolts from below will be schematically described below.

Referring to FIG. 4, reference numeral 90 indicates a torque converter assembly system. This torque converter automatic assembly system 90 includes a shuttle unit 94 that fixes a torque converter 92 as a workpiece in a reference direction, a manipulator 96 that grips the torque converter 92 on the shuttle unit 94, and a jig. Bolt installation in which bolts fed from a movable loader 102 as a means for transporting the torque converter 92 to the engine 100 on a pallet 98 and a supply pipe 104 from a parts feeder (not shown) are set in the bolt tightening device 10 according to the present invention. It is composed of a device 106 and the bolt tightening device 1o.

The shuttle unit 94 is configured to be able to move horizontally above the rail mount 108. Mobile loader 10
2 is configured to be movable on a beam 112 extending horizontally from a support 110 via a rail under the driving action of a travel cylinder 114.

Furthermore, the mobile loader 102 is equipped with an elevating cylinder 115 for elevating the manipulator 96, and the manipulator 96 is lowered under the driving action of the elevating cylinder 115, and the clamp arm 1 forming the manipulator 96 is
16a to 116C grip torque converter 92 on shuttle unit 94. In this case, the manipulator 96 is also provided with a phase matching device 118 for changing the position of the screw hole of the torque converter 92. It is equipped with a drive system consisting of a pulse motor rotating 120, a reduction gear, a clutch, etc.

As shown in FIG. 5, the bolt mounting device 106 includes a bolt receiver holder 122 that receives a bolt fed under the pressure of compressed air through the supply pipe 104 extending from the parts feeder. The bolt receiver holder 122 is provided with a pair of chucks 124a and 124b that can be opened and closed to hold the bolt therein. The bolt mounting device 106 also includes opening/closing rods 126a and 126b that abut the chucks 124a and 124b to open them;
A driver 128 is provided which descends at the same time as these opening/closing rods 126a and 126b to hold the bolt in the bolt holder holder 122 and to attach the bolt to the socket 82 of the nut runner 46 for the bolt tightening device 10 located below. ing. These opening/closing rods 126a.

126b and the driver 128 are movable up and down under the driving action of the cylinder 129.

The bolt tightening device according to the present invention and the torque converter automatic assembly system having this bolt tightening device as one component are basically constructed as described above, and the operation and effects thereof will be explained next. do.

First, in FIG. 4, the torque converter 9 mounted above
The shuttle unit 94 is moved on the rail mount 108 with the screw holes 2 aligned with the reference direction, and the torque converter 92 is positioned directly below the movable loader 102 shown in the figure. Therefore, the manipulator 96 is lowered by extending the piston rod (not shown) of the lifting cylinder 115 provided on the movable loader 102. Then, by operating this manipulator 96, the clamp arms 116a to 116C operate the torque converter 92.
to grasp. Thereafter, the manipulator 96 is raised under the driving action of the elevating cylinder 115, and the piston rod of the travel cylinder 114 is retracted so that the mobile loader 1
Engine 100 fixed on pallet jig 98
Move it to just above. At that position, lift cylinder 1 again.
15 piston rod is extended, and the clamp arm 11
The torque converter 92 is placed on the drive plate 130 of the engine 100 by lowering the manipulator 96 while holding the torque converter 92 at points 6a to 116C. At this time, torque converter 9
The screw holes drilled in the lower periphery of 2 and the holes drilled in the periphery of the drive plate 1300 match because the screw holes of the torque converter 92 are aligned in advance with the reference direction on the shuttle unit 94. Ru. At this time, gear 120 of phase matching device 118 meshes with starter gear 119 of torque converter 92 .

Then, the bolt is mounted on the bolt tightening device 10 by the bolt mounting device 106. That is, the bolt is fed into the bolt receiving holder 122 of the bolt mounting device 106 through the supply pipe 104 with its head directed downward. At this time, as shown in FIG. 5, chucks 124a, 1
24b is closed, and the bolt is inserted into this chuck 124a,
124b. In the bolt tightening device IO, it is assumed that in the initial state, the nut runner 46 is on standby with its socket 82 positioned directly below the bolt holder holder 122. In this state, cylinder 12
9, the opening/closing rods 126a, 126b right and the driver 128 are lowered. The driver 128 enters the bolt receiver holder 122 and holds the bolt therein. Eventually, the opening/closing rods 126a, 126b
The tips abut the chucks 124a, 124b, and the lower ends of the chucks 124a, 124b are rotated in a direction in which they are opened and expanded. Then, as the driver 128 descends, the bolt at the tip of the driver 128 is attached to the socket 82. FIG. 2 shows the bolt mounted in the socket 82 in this manner. In this case, the piston rod 24 of the feed cylinder 22 is extended to
The cover 18 and the nut runner 46 integral therewith are advanced on the two slide rails 14a and 14b, and the bolt fitted in the socket 82 is positioned directly below the screw hole position of the torque converter 92. As the cover 18 moves forward, the stopper 42 comes into contact with the wedge 38 of the work type switching cylinder 34, thereby positioning the bolt fitted in the socket 82. Note that if the model of the torque converter 92 is different, the work type switching cylinder 3
4 to retract the wedge 38. At this time, the stopper 4 is attached to the regulating member 40 whose mounting position is selected corresponding to the screw hole position of the torque converter of interest.
2 are in contact with each other, the bolt is positioned directly below the thread size of the torque converter. That is, it is possible to use one bolt tightening device 10 to handle these different types of workpieces.

Then, the tightening mechanism section 20 is driven to screw in the bolt. That is, the piston rod 52 of the lifting cylinder 50 is extended. The integral nut runner 46 is upwardly displaced along the guide rod 58 via the support rod 54 connected to the piston rod 52 and the connecting portion 48 . Then, a bolt that fits into the socket 82 at the tip of the nut runner 46 enters a hole provided at the periphery of the drive plate 130 of the engine 100. At this time, the balance spring 56 connects the connecting portion 48 and the nut runner 46.
Since the bolt is elastically supported, the bolt can be inserted smoothly without the inconvenience of the bolt being tilted due to an impact being applied to the bolt. Furthermore, even if the bolt is slightly eccentric from the hole in the drive plate 130, as long as the bolt is exposed to the hole, the elastic rings 62 and 64 interposed at both ends of the guide rod 58 in FIG. 4 will be deformed. Then, the nut runner 46 moves slightly in the horizontal direction, and the shift can be compensated for. In this case, the diameter of the hole in the drive plate should be slightly larger than the diameter of the bolt so that the bolt can easily enter.

Therefore, the drive motor 44 is driven. The rotation is transmitted from the rotary shaft 66 to the drive shaft 70 and the driven shaft 74, and is further shifted to high rotation by a gear train consisting of the first gear 76, second gear 78, and third gear 80, and the socket 82 is rotated at high speed. Rotate. As a result, the bolt that fits into the socket 82 is screwed into the screw hole of the torque converter 92. After the bolt is threaded into the screw hole and a predetermined tightening torque is obtained, the drive motor 44 is stopped. Then, contrary to the above, the piston rod 52 of the elevating cylinder 50 is moved back, and the nut runner 46 is retracted downward. Furthermore, feed cylinder 2
The second piston rod 24 is moved back, the tightening mechanism section 20 itself is moved back, and the position of the socket 82 of the nut runner 46 is returned to the initial position shown in FIG. At this position, the next bolt is installed in the socket 82 by repeating the operation of the bolt installation device 106 described above. At the same time, the starter gear 119 of the torque converter 92
Since the gear 120 of the phase matching device 118 is engaged with the gear 120, the torque converter 92 and the drive plate 130 are rotated by a predetermined angle by the phase matching device 118 to match the phase of the next screw hole position. Thereafter, the bolts are similarly tightened using the bolt tightening device °10.

By repeating the above operations, the work of attaching the torque converter 92 to the drive plate 130 of the engine 100 is automatically performed.

[Effects of the Invention] As described above, according to the present invention, a tightening means such as a nut runner equipped with a socket for rotating a bolt is elastically supported by a balance spring, and is provided with vertical play and is interposed in a guide rod. The horizontal play of the nut runner is ensured by the elastic ring body installed, so the bolt can be inserted smoothly into the screw hole of the workpiece.
Therefore, the effect of preventing the bolt from twisting can be obtained.

Although the present invention has been explained above by citing preferred embodiments, the present invention is not limited to these embodiments, and various improvements and changes in design can be made without departing from the gist of the present invention. Of course.

[Brief explanation of the drawing]

1 is a perspective view of a bolt tightening device according to the present invention, FIG. 2 is a sectional view of the bolt tightening device, and FIG. 3 is a sectional view taken along the line ■-■ of the bolt tightening device in FIG. Fig. 4 is a side view showing a schematic configuration of a torque converter assembly system that includes the bolt tightening device as a component, and Fig. 5 shows a bolt mounting device installed in the torque converter assembly system shown in Fig. 4. It is a perspective view showing the relative position of the bolt tightening device concerning the present invention. 10... Bolt tightening device 12... Frame 19
...Main body part 20...Tightening mechanism part 2
2...Feed cylinder 26...Joint member 3
4...Work type switching cylinder 38...Wedge 4
0... Displacement regulating member 42... Stopper 4
4... Drive motor 46... Nut runner 50... Lifting cylinder 56... Balance spring 58... Guide rod 62.64... Elastic ring 82... Socket 90... Torque converter automatic assembly Attached system 9
2... Torque converter 94... Shuttle unit 96... Manipulator 102... Mobile loader 104... Supply tube 106... Bolt mounting device

Claims (5)

[Claims] (1) A device for screwing in and tightening fastening members such as bolts from the underside of a workpiece, which includes a main body connected to a first actuator and movable horizontally, and a device disposed in front of the main body. a tightening means that is displaced vertically under the driving action of a second actuator to tighten a bolt or the like against a workpiece; and a positioner that allows the forward position of the tightening means to be adjusted to at least two positions. A bolt tightening device comprising: an adjustment means. (2) In the device according to claim 1, the tightening means is connected to the main body and the second actuator via an elastic member, and play is provided to allow slight deviation in the horizontal and vertical directions. A bolt tightening device featuring: (3) In the device according to claim 2, a coil spring is interposed in the connecting portion between the tightening means and the second actuator, and both support ends of the guide rod that guides the upward and downward displacement of the tightening means are deformable. A bolt tightening device characterized by being equipped with an elastic ring. (4) In the device according to claim 1, the tightening means has a socket at the tip of its upper surface into which the head of a bolt or the like fits;
A bolt tightening device comprising a nut runner that rotates the socket by changing the rotation speed of a rotary drive source at high speed using a gear train. (5) The bolt tightening device according to claim 1, wherein the positioning adjustment means comprises a cylinder that advances and retreats a wedge that engages with a stopper provided on the main body.