JPH0338075B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention has a polygonal part at the tip of the bolt shaft.
This invention relates to a power torque wrench for shear bolts used to tighten or disassemble high-strength torque tension bolts formed in stages.

(Prior art) When tightening a bolt, there is a known method in which the polygonal part at the tip of the bolt breaks off from the notch part when the tightening force reaches a certain level as a means of checking whether the torque is applied correctly. There are, but
If the notch breaks, there is a problem that it cannot be retightened or redisassembled, so recently, as shown in Fig. 4, a notch 4a is provided in the middle of the polygonal part, and two stages of the polygonal parts 4 and 4' in the front and rear are formed. High-strength torque tension bolts have been developed.

Hitherto, known torque wrenches for tightening such bolts are disclosed in Japanese Patent Laid-Open No. 48-72796, Japanese Patent Publication No. 55-21674, and the like.

(Problem to be Solved by the Invention) However, conventional torque wrenches are not designed for bolts that have two polygonal sections, front and rear, and cannot be refastened or disassembled. After the notch breaks, the limit point of torque is not clear because there is no notch, and therefore the bolt has to be tightened by feel.

The present invention has been made in view of the above-mentioned problems of the conventional technology, and its purpose is to provide a high-strength torque tension bolt with a two-step polygonal portion at the tip of the bolt. By breaking the polygonal part of the first stage, it is possible to fasten with the appropriate torque, and after the fastening, the polygonal part of the second stage can be used to easily retighten and disassemble. The present invention aims to provide a power torque wrench for shear bolts which can be switched off and automatically stopped when the tightening torque reaches a predetermined value during retightening.

(Means for Solving the Problems) In order to achieve the above object, the power torque wrench for shear bolts according to the present invention has a nut fitting opening 2a at the tip so as to screw the nut 1 screwed onto the bolt 3 to be fastened. a socket body 2 having
In this socket body 2, the socket tube shaft 5 having a bolt fitting opening 5a at the tip is individually rotated so as to rotate the two stages of polygonal parts 4 and 4' formed at the shaft end of the bolt 3. The socket body 2 and the socket tube shaft 5 are provided so as to be supported concentrically inside and outside the wrench body 6, and the socket body 2 and the socket tube shaft 5 are driven to rotate in opposite directions by the reaction force of the motor 7 through the planetary gear mechanism 8. In this torque wrench, the socket body 2 is provided so as to be slidable back and forth in the axial direction via a spring 9 with respect to a wrench body 6 having a socket tube shaft 5 therein, and the rear end of the slidable socket body 2 is a pair of proximity switches 10,
11 is provided, and the other proximity switch 11 is provided on the corresponding fixed part on the side of the wrench body 6 so as to be adjustable in the rotational direction.
11 on the socket body 2 side.
When the wrench body 6 moves forward with respect to the socket body 2 when retightening the socket body 2, the opposing distance approaches and the tightening torque reaches a predetermined value, the switch is turned off. The tip 12a is set so that the bolt fitting opening 5 is located at the hollow shaft center of the socket tube shaft 5.
A freely slidable push-out rod 12, which faces the wrench body 6 and has a rear end 12b protruding from the wrench body 6, is installed therethrough.

Further, the extrusion rod 12 can be formed of a hollow tube and used as a paint spraying nozzle.

Furthermore, it is preferable that the proximity switch 11, which is fixed to the wrench body 6 side of the proximity switches, is provided on an adjustment sliding ring 18 that is rotatable in the rotational direction with respect to the wrench body 6.

(Example) The socket body 2 has a fitting opening 2a for the nut 1 at the tip.
Internal teeth 2b are formed on the inner surface of the cylindrical portion, and a planetary gear 8a meshes with the internal teeth 2b.

In the hollow interior of the socket body 2, the socket tube shaft 5 has a two-stage polygonal section 4 at the front end of the bolt end.
(or 4) has a fitting opening 5a into which it is fitted, and external teeth 5b that mesh with the planetary gear 8a are formed on the outer periphery of the tip.

This socket tube shaft 5 is fitted and held within the hollow portion of a hollow cylindrical drive shaft 13. A motor 7 is incorporated into a part of the main body 6, and gears 14, 15, 16, 1
The drive shaft 13 is rotatably driven through the shaft 7.

A sliding ring 18 whose moderation is adjusted in the rotational direction is fitted into the circumference of the wrench body 6, and one of the proximity switches 11 is attached to this. Recesses 21 in which moderating spheres 20 pressed by a spring 19 are fitted into the sliding ring body 18 and arranged at predetermined intervals on the outer periphery of the main body 6.
The positioning is performed by fitting it into the holder, and when changing the facing position, the holder can be adjusted as desired by forcibly rotating the holder. A scale 22 is provided on the outer peripheral surface of the sliding ring body 18 to facilitate minute adjustments.

A nozzle pipe 12 for spraying paint is attached to a socket pipe shaft 5.
The tip opening 12a is inserted into the hollow interior and the tip opening 12a is the insertion opening 5.
The rear end portion 12b protrudes from the rear end of the main body 6, is supported by a trigger type pusher 23, and is slid forward when the pusher 23 is pushed.

A paint socket 24 is provided on the rear upper surface of the wrench body 6, to which a paint container 25 is detachably connected and communicated with the nozzle pipe 12 through a pipe 26.

(Operation) Pass the bolt 3 through the fastener 27, temporarily tighten the nut 1, apply this torque wrench to it, fit the nut 1 into the socket body 2, and put the polygonal part 4' into the inner socket tube shaft 5. When the start switch 28 of the motor 7 is operated, the socket body 2 rotates in the direction of tightening the nut 1 via the planetary gear mechanism 8, and the inner socket tube shaft 5 rotates the bolt polygon 4' in the opposite direction. The force that causes it is transmitted. Therefore, when the tightening force reaches a predetermined value, the notch 4a between the front and rear polygonal portions 4, 4' is broken, so that the nut 1 can be attached to the bolt 3.
This means that it has been tightened to a predetermined torque. 1
When the polygonal part 4' of the first stage is broken, the separated polygonal part 4' of the first stage is pushed out by the pushing rod 12 and discharged to the outside. When this first step polygonal part 4' is screwed, the socket body 2 is in a position pushed forward with respect to the wrench body 6 by the spring 9, and therefore the two corresponding proximity switches 10 and 11 are in a large position. Since they are separated from each other by a large distance, they do not work even if they are rotated to face each other (Figure 3a).

If you want to further tighten the bolt 3 and nut 1 by using the second polygonal part 4 remaining on the threaded side of the bolt 3, press the wrench body 6 while the nut 1 is fitted into the socket body 2. , socket body 2
moves so as to compress the spring 9 and pull it backward with respect to the wrench body 6, so that the polygonal part 4 fits into the fitting opening 5a at the tip of the socket tube shaft 5. This movement of the socket body 2 causes the proximity switches 10 and 11 to move to the third position.
As shown in Figure b, they are in close proximity to each other, and in this state the socket body 2 is rotated and tightened.

During this re-tightening, since the second stage polygonal part 4 without a notch is fitted into the socket tube shaft 5, the socket tube shaft 5 is subjected to greater resistance in the reverse rotation direction than before, so it does not rotate. , it is in a stopped state.
In the case of this re-tightening, since there is no notch, if the bolt is screwed to the limit, the shear stress of the bolt will pass the yield point and enter the plastic limit region, but the proximity switches 10 and 11 located in the vicinity will cause the socket body 2 to rotate. When they reach a certain position, they come close to each other and face each other, and at that moment they switch off. Therefore, since the plasticity limit area is detected, if it is set in advance to an appropriate position, the switch can be turned off and stopped just before the plasticity limit area is detected. When the retightening is completed, the pressure is loosened, but at this time, the tip end 12a of the nozzle pipe 12 separates from the polygonal part 4, so paint is blown out and applied to the end face of the polygonal part 4.
Therefore, the bolts and nuts that have been retightened will be marked with this paint for future confirmation.

(Effects) As described above, the present invention provides the socket body 2 so as to be able to slide back and forth in the axial direction with respect to the socket tube shaft 5 via the spring 9, and also provides the socket body 2 at the rear end portion of the slidable socket body 2. One of the pair of proximity switches 10 and 11 is provided, and the other proximity switch 11 is provided at the corresponding fixed part on the side of the wrench body 6, and the switch on the socket body 2 side is connected to the socket body. The hollow shaft center portion of the socket tube shaft 5 is set so that it faces the fixed side switch every time the socket body 2 rotates once with the socket body 2, and the switch is turned off when the opposing distance approaches a predetermined value when the socket body 2 is pushed in. Since a slidable push-out rod 12 is installed through the bolt with its tip 12a facing the bolt fitting opening 5a and its rear end 12b protruding from the wrench body 6, a high-strength torque tension rod with a two-stage polygonal section provided at the tip of the bolt is created. After breaking the first stage bolt, you can easily and retighten the polygonal part of the second stage without a notch, and when retightening, you can determine the limit point of the tightening force in advance. It can be set using a proximity switch and tightened to the specified level safely and reliably.
Moreover, the end face of the polygonal part of the bolt that has been tightened can be sprayed with marking paint from a paint spray nozzle that also serves as an extrusion rod fitted into the hollow interior of the socket tube shaft, making it easy to tighten the bolt. This is convenient for later confirmation. Furthermore, the extrusion rod can extrude cut polygonal parts easily and reliably, and the structure is simple, durable, and can be implemented at low cost.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a side view of a torque wrench, with main parts shown in cross section. 2 is a sectional view taken along the line A--A in FIG. 1, FIGS. 3a and 3b are side views showing the working state of the contacts, and FIG. 4 is a side view of the torque tension bolt. 1... Nut, 2... Socket body, 3... Bolt, 4, 4'... Polygonal part, 5... Socket tube shaft,
6...Wrench body, 7...Motor, 8...Planetary gear mechanism, 9...Spring, 10, 11...Proximity switch, 12...Extrusion rod (nozzle pipe), 2a, 5a
...Insert entrance.

Claims (1)

[Scope of Claims] 1. A socket body 2 having a nut fitting opening 2a at its tip so that the nut 1 screwed onto the bolt 3 to be fastened can be rotated, and a socket body 2 having a nut fitting opening 2a at the tip thereof, and a socket body 2 provided at the shaft end of the bolt 3 in the socket body 2. The formed front and rear two-stage polygonal portion 4,
Bolt fitting opening 5a at the tip so as to rotate 4'
A socket tube shaft 5 with
In this torque wrench, the socket body 2 is rotated by a motor 7 through a planetary gear mechanism 8 in opposite directions by the reaction force thereof, and the socket body 2 is connected to a wrench body 6 having a socket tube shaft 5 inside by a spring 9. One of the pair of proximity switches 10 and 11 is provided at the rear end of the slidable socket body 2, and one of the proximity switches 10 and 11 is provided at the corresponding fixed part on the side of the wrench body 6. The other proximity switch 11 is provided, and both proximity switches 10,
11 on the socket body 2 side.
and the wrench body is moved forward relative to the socket body when re-tightening the socket body 2, and when the opposing interval approaches and the tightening torque reaches a predetermined value, the switch is turned off. and set the socket tube shaft 5 to
A power torque wrench for a shear bolt, characterized in that a slidable extrusion rod 12 is installed through a hollow shaft center portion of the shear bolt, with a tip 12a facing a bolt insertion opening 5a and a rear end 12b protruding from a wrench body 6. 2. The power torque wrench for shear bolts according to claim 1, wherein the extrusion rod 12 is formed of a hollow tube and serves as a nozzle for spraying paint. 3. The power torque wrench for shear bolts according to claim 1, wherein the proximity switch 11 fixed to the wrench body 6 side of the proximity switches is provided on an adjustment sliding ring 18 that is adjustable in the rotational direction.