JP3000974U - Fastening position display structure for fasteners - Google Patents

Abstract

(57) [Summary] [Purpose] For fasteners such as bolts and nuts, while displaying the rotation angle that ensures a predetermined tightening axial force when tightening from the temporarily tightened state to complete the tightening, Make sure there are no variations in the tightening amount. [Structure] A provisional tightening position display mark 38 and a fastening completion position display mark 39 are formed on the claw mounting portion 30 of the chuck arm, and the bolt 2 mounted on the chuck claw 26 is formed.
When the C-shaped ring 37 is fitted to the head portion 28B of 8, the chuck claw 26 is attached to the claw attachment portion 30 and the bolt 28 is tightened, the opening 36 of the C-shaped ring 37 is temporarily tightened at the temporary tightening position. It is configured such that a predetermined tightening axial force can be obtained when the bolt 28 is tightened from the position aligned with the position display mark 38 to the position where the opening 36 matches the fastening completed position display mark 39.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fastening position indicating structure when fastening fasteners such as bolts and nuts to a fastened object.

[0002]

[Prior art]

 When the object to be fastened is fastened with bolts or nuts, if loosening occurs due to vibration or other external force after this fastening, the predetermined tightening axial force will be lost and fastening failure will occur. Since it is difficult to determine the looseness of the nut, for example, in Japanese Utility Model Laid-Open No. 4-62409, the above looseness is eliminated by marking the bolt shaft portion, the nut surface, the washer, and the object to be fastened after fastening. A technique has been disclosed in which it is possible to make a visual judgment from the deviation of the mark.

[0003]

[Problems to be solved by the device]

 By the way, as described above, fastening with bolts and nuts is performed by rotating these bolts and nuts with a torque wrench or the like so as to obtain a predetermined tightening axial force, but the bolts and nuts were rotated with a constant tightening torque. However, it is not always possible to obtain the prescribed tightening axial force due to the presence of screws, seat dents, rust, or oil adhesion. There was a problem that the tightening axial force was not constant due to variations in the tightening rotation angle until the completion of tightening.

Therefore, an object of the present invention is to provide a fastening position display structure of a fastener that can easily indicate a tightening rotation angle from a state where a bolt or the like is temporarily tightened to a time when a predetermined tightening axial force is obtained.

[0005]

[Means for Solving the Problems]

 That is, the present invention is a structure for displaying a fastening position of a fastener that fastens an object to be fastened by screwing, and a fastening position indicating mark is completed at the periphery of the shaft hole formed in the fastener. A ring having a position indication mark at a predetermined angle and having elasticity that can be expanded / contracted in the diametrical direction on the fastener and a rotation angle indication mark for indicating the rotation angle position, has the rotation angle indication mark. It is characterized in that it is rotatably fitted so as to be positioned corresponding to the temporary tightening position display mark and the fastening completion position display mark.

[0006]

[Action]

 According to the above configuration, when the fastener is rotated and tightened and the fastener does not rotate due to the contact friction with the surface of the object to be fastened, the rotation angle display mark of the ring becomes the temporary fastening position display mark. Then, the fasteners can be tightened until the rotation angle display mark matches the tightening completion position display mark, and the tightening rotation angle from the temporarily tightened state to the completion of tightening is constant.

[0007]

【Example】

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

FIG. 1 and FIG. 2 show a multi-stage pressure forming machine 1 equipped with a material transfer chuck to which the present invention is applied. A plurality of machines (four in the figure) are arranged side by side on a machine base 2 at regular intervals. A die block 4 having dies 3 to 3 (see FIG. 2) is provided, a ram 5 is provided on the machine base 2 so as to face the die block 4, and the same number of punches as the dies 3 are provided on the front surface of the ram 5. 6 to 6 are provided. In that case, the rear end of the ram 5 is connected to the crank arm 8 of the crankshaft 7 through the rod 9, and the rotational force of the forging machine driving motor 10 is transmitted through the pulleys 11 and 12 and the belt 13 to the crankshaft. The ram 5 is moved back and forth once for each revolution of the crankshaft 7 by transmitting the force to the punches 7, and the punches 6 to 6 are moved forward and backward with respect to the dies 3 to 3 by the forward and backward movements. A predetermined forming operation of the material X (see FIG. 2) is performed in each forging station including the punch 6 and the punch 6.

On the other hand, the chuck block support frame 15 is attached to the base shaft 14 on the machine base described above, and the front end of the support frame 15 is placed on the die block 4, and the front end of the chuck block support frame 15 is mounted on the die block 4. A chuck block 16 is swingably supported in the direction in which the dies 3 to 3 are arranged side by side. Further, the rotation of the crankshaft 7 is taken out by the gears 17A, 17B, 17C, 17D and transmitted to the drive shaft 19 supported by the bracket 18 on the side portion of the machine base 2, and the rotational force is transmitted to the drive shaft 19. It is input to the chuck block 16 via a lever 21 by a cam 20 fixed to the drive shaft 19, whereby the chuck block 16 reciprocates in synchronization with the longitudinal movement of the ram 5, and the chuck block 16 is mounted on the chuck block 16. The material transfer chucks 22 to 22 are moved between the adjacent dies 3 and 3, and the material X projected from each die 3 to 3 by a knockout pin (not shown) is grasped and transferred.

The material transfer chucks 22 to 22 are attached to the front surface of the chuck block 16 at the same intervals as the dies 3 to 3, and are attached to the chuck opening / closing cam shaft 23 mounted on the machine base 2. The driving cams 24 to 24 of each chuck 22 are fixedly installed, and a rotational force is input to the chuck opening / closing cam shaft 23 from the bevel gears 17E and 17F provided on the driving shaft 19 via the transmission mechanism 25. By this, the chuck claws 26, 26 (see FIG. 3) of each material transfer chuck 22 are opened and closed in synchronization with the forward and backward movement of the ram 5, and the interference between the punch 6 and the chuck 22 when the ram 5 is advanced is avoided. It is designed to do.

By the way, in the forging machine 1, since the size and shape of the material to be grasped by the material transfer chuck 22 changes according to the size and shape of the product to be forged, the chuck claw 26 is replaced. Therefore, the chuck claw 26 is removably fastened to the chuck arm 27 by the bolt 28.

That is, as shown in FIGS. 3 to 5, the chuck arm 27 is attached to a support shaft 29 so as to be rotatable around the support shaft 29, and a claw attachment portion 30 at the tip of the chuck arm. A substantially U-shaped bolt insertion hole 31 is formed from the lower end to the upper side, and an engaging recess 32 (see FIG. 5) is formed on the back surface of the claw mounting portion 30, while the chuck claw 26 The bolt 28 is screwed into the screw hole 33 provided on the front surface of the upper end portion. Then, the upper end of the chuck claw 26 is fitted into the engaging recess 32 from below so that the shaft portion 28A of the bolt 28 can be inserted into the bolt insertion hole 31, and then the bolt 28 is screwed in to attach the chuck claw 26 to the claw mounting portion 30. Secure by attracting to.

In this case, in the present invention, a square hole 34 for engaging a wrench (not shown) is formed in the bolt head 28B, and a notch is formed in the lower outer peripheral corner of the bolt head 28B. A concave step portion 35 is formed, and a C-shaped ring 37 having an opening 36 is engaged with the concave step portion 35. The C-shaped ring 37 is a metal body or a resin body having elasticity capable of expanding and contracting in the diametrical direction. In the above engagement state, the C-ring 37 elastically fits into the concave step portion 35 and rotates integrally with the bolt head portion 28B. It is designed to do.

On the other hand, in the above-mentioned claw mounting portion 30, at the peripheral portion of the bolt insertion hole 31 and at the portion outside the bolt head portion 28B when the bolt 28 is fitted into the bolt insertion hole 31. The temporary tightening position display mark 38 (snag point or seating point) and the fastening completion position display mark 39 are provided at a predetermined rotation angle. The marks 38 and 39 are formed by applying a paint or engraving the nail mounting portion 30.

According to such a structure, when the bolt 28 is screwed from the state where the chuck claw 26 is fitted in the claw mounting portion 30, the socket wrench is inserted into the square hole 34 and the bolt 28 is rotated. The C-shaped ring 37 rotates integrally with the head portion 28B, the screwing proceeds, and the bolt head portion 28B comes into contact with the surface of the claw mounting portion 30. Due to the friction, the rotation of the bolt 28 is resisted and the bolt 28 is temporarily tightened. , The C-shaped ring 37 is expanded in diameter using the opening 36 and independently rotated with respect to the bolt head 28B, and the opening 36 is temporarily tightened. Tightening can be performed by aligning with the mark 38 and then by tightening the bolt 28 with a wrench until the opening 36 is aligned with the fastening completion position indicating mark 39.

Therefore, according to the above-described structure, when the bolt 28 is tightened from the temporarily tightened state with respect to the angle between the temporary tightening position display mark 38 and the fastening completion position display mark 39, a predetermined tightening axial force is generated. If you set it to the one that can be obtained, the prescribed tightening axial force can be obtained easily and reliably, and the tightening rotation angle from the temporary tightening state to the completion of tightening will be constant, so there will be variations in the tightening rotation angle. It will not occur. Further, in the fastening completed state, the fastening completion position display mark 39 and the opening 36 of the C-shaped ring 37 are aligned with each other. Therefore, even if the bolt 28 is loosened thereafter, this should be marked with the mark 39 and the opening. It can be easily visually detected from the positional deviation from the portion 36.

The mounting position of the C-shaped link 37 may be the position shown by the chain line in FIG. Further, the present invention can be applied to a fastening portion with a nut, and similarly to the case of the above bolt, a temporary fastening position display mark 38 and a fastening completion position display mark 39 are provided around the bolt through hole provided in the object to be fastened. After screwing the nut into the bolt passed through the bolt through hole and aligning the opening 36 of the C-shaped link 37 with the temporary tightening position display mark 38 in the temporarily tightened state, the opening 36 matches the fastening completion position display mark 39. Tighten

Further, according to the present invention, when the initial tightening torque is reached by applying a rotational force to the outer periphery of the C-shaped ring 37 due to the strength of the engagement between the C ring 37 and the bolts and nuts, the snag point (seating point) is rotated. It can also be applied to required bolts and nuts with a torque limiter. Further, the above C-shaped ring may be a complete annular elastic ring, in which case a rotation angle indicating mark corresponding to the opening 36 is formed on the elastic ring.

[0019]

[Effect of device]

 As is clear from the above description, according to the present invention, when the fastener is tightened and the fastener does not rotate due to contact friction with the surface of the object to be fastened, the rotation angle display mark of the ring is displayed. Fastening can be done by aligning with the temporary tightening position display mark and then tightening up to the angle where the rotation angle display mark matches the fastening completion position display mark, thereby obtaining the predetermined tightening axial force and completing the tightening from the temporary tightened state. Since there is no variation in the tightening rotation angle up to, the state can be easily checked visually even after tightening.

[Brief description of drawings]

FIG. 1 is a plan view of a multi-stage press forming machine to which the present invention is applied.

FIG. 2 is a front view of a die block portion of the press forming machine.

FIG. 3 is an enlarged view of a material transfer chuck of the press molding machine.

FIG. 4 is an enlarged view of a main part of FIG.

5 is a half cutaway view of FIG. 4. FIG.

[Explanation of symbols]

 26 Chuck Claw 27 Chuck Arm 28 Bolt 31 Bolt Insertion Hole 36 Opening 37 C-shaped Ring 38 Temporary Fastening Position Display Mark 39 Fastening Completion Position Display Mark

Claims (1)

[Scope of utility model registration request] 1. A fastening position indicating structure of a fastener for fastening an object to be fastened by screw connection, wherein a temporary fastening position display mark and a fastening completion position display are provided on a peripheral portion of a shaft hole formed in the fastener. The mark is provided at a predetermined angle, and a ring having diametrically expandable / contractible elasticity in the fastener and a rotation angle display mark for displaying the rotation angle position is provided, and the rotation angle display mark is temporarily tightened. A fastening position display structure of a fastener, which is rotatably fitted so as to be positioned corresponding to a position display mark and a fastening completion position display mark.