JPH07224830A - Self-lock bolt manufacturing equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] A manufacturing device that can roll a self-locking bolt that has a slit along the top of a screw thread with high precision and efficiency and that can improve product quality and yield. provide. [Structure] A first flat die that forms a multiple thread in the lead, and the same lead as the multiple thread is engaged with the thread grooves with a constant number of thread grooves to aggregate a plurality of thread threads to form a single thread thread. The second flat die described above is held on a common die holding table so that the relative position can be adjusted. The relative positions of the first flat die and the second flat die may be adjustable in one of the rolling direction and the direction orthogonal thereto, or may be adjusted in a plurality of directions at the same time. Further, at least one of them may be adjustable in the direction in which the bolt material is sandwiched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a slit formed along the top of a screw thread, and when screwed into a nut, the flank of the screw thread is compressed by the flank on the nut side to elastically deform toward the slit side. The present invention relates to a self-lock bolt manufacturing device having a lock function.

[0002]

2. Description of the Related Art A self-locking bolt having a slit formed along the crest of the thread of the bolt is known (Japanese Patent Publication No.
No. 58016). In this bolt, the flank on the nut side presses the flank on the bolt side toward the slit to elastically deform the bolt, and the restoring force of the elastically deformed bolt flank prevents the bolt from loosening.

Japanese Patent Publication No. 2-58016 has been proposed as a method of manufacturing this type of self-locking bolt. In this method, after rolling a two-thread screw, two ridges are assembled using a mold having the same lead as the two-thread screw and are rolled into one ridge.

FIG. 4 is a diagram showing a first rolled bolt and a die used therefor by this method, FIG. 5 is a diagram showing a second rolled bolt and a die used there, and FIG. 6 is a multiple thread screw. FIG. 7 is an enlarged view of the (double-threaded screw), FIG. 7 is an enlarged view of the manufacturing process, and FIG. 8 is an enlarged view showing a nut tightened state.

In FIG. 4A, reference numeral 10 is a bolt material, and a bolt head 14 is formed on a bolt shaft portion 12 by cold forging or the like. Reference numeral 16 is a flat die used for the first rolling, and has a double thread type screw portion 18 extending in the rolling direction (horizontal direction in FIG. 4B).

The double thread type screw portion 18 is formed by the bolt shaft portion 12.
Outer peripheral length A = 2πR (see FIG. 6, where R is the radius of the bolt shank 12), that is, the lead amount of the screw thread, that is, the lead L.
It is formed to have two threads inside. This two-thread screw has two threads in the lead L and is
The distance L and the outer peripheral length A have a relationship as shown in FIG. In FIG. 6, the even-numbered (or odd-numbered) screw grooves g1 are shown by solid lines, and the odd-numbered (or even-numbered) screw grooves g2 are shown by broken lines.

If the bolt shaft portion 12 is sandwiched between a pair of dies 16 and both dies 16 are moved in opposite directions while being pressed, as shown in FIG.
The double thread portion 20 is rolled.

A second rolling process is applied to the double thread portion 20 by a die 22 shown in FIG. 5 (B). The die 22 is formed with a single-thread screw-shaped portion 24 having the same lead as that of the double-thread screw-shaped portion 18 of the die 16 and having a double pitch. The single thread screw portion 24 has a sectional shape 24A indicated by an imaginary line in FIG.

By preparing a pair of dies 22 having the single thread type screw portion 24, stacking them on the double thread screw portion 20 and translating them in the opposite direction, the single thread portion 26 shown in FIG. Is built. That is, the ridge of the mold of the single thread screw part 24 is engaged with the even-numbered (or odd-numbered) thread groove g1 (or g2) of the double-threaded screw part 20 and pushes the thread groove g1 (or g2) deeply. open. Therefore, as shown in FIGS. 7 (A) and 7 (B), two screw threads m1 and m2 are gathered to form a single thread screw type portion 2
A single threaded portion 26 having a cross-sectional shape 24A of 4 is formed.

The single-thread screw portion 26 has a slit 28 in the thread groove g2, and elasticity is imparted to the respective portions m1 and m2 sandwiching the slit 28 by performing a predetermined heat treatment.
Note that, in FIG. 7B, the same reference numerals are given to corresponding portions in FIG. 7A.

Here, the cross-sectional shape 24A of the single thread screw portion 24 is shown.
That is, the shape of the thread of the single thread portion 26 is pressed by the flank 30A of the nut 30 with the nut 30 screwed in, as shown in FIG. That is, the single thread 26
The flank 26A is pressed by the flank 30A of the nut 30 and elastically deforms in the direction of narrowing the slit 28. Therefore, the flank 26A of the single threaded portion 26 presses the flank 30A of the nut 30 to generate frictional resistance, and the nut 30 is prevented from loosening.

Heretofore, the first rolling and the second rolling have heretofore been performed separately in two rolling steps. That is, the first rolling was performed using the first rolling flat die, and in the second rolling, the flat die was replaced with the second rolling die and the same work was performed twice separately.

In order to efficiently manufacture such a self-locking bolt, it has also been proposed to integrally form a first rolling flat die and a second rolling flat die (Japanese Patent Laid-Open No. 2000-242242). (See Sho 62-241613). That is, die blades for the first rolling and the second rolling are formed side by side in the rolling direction on one flat die, and the first rolling and the second rolling are continuously performed in one rolling step. It is a thing.

[0014]

2. Description of the Related Art In the method of exchanging the dies for the first rolling and the second rolling separately twice, not only the number of steps becomes two, but also the exchange of the flat dies is required. There was a problem that production efficiency was poor.

On the other hand, in actual rolling using a flat die, it is necessary to finely adjust the distance between the pair of flat dies that sandwich the bolt material. For example, such fine adjustment is necessary when the material or diameter of the bolt material is subtly changed or when the die is worn. When the distance between the first dies is changed in this way, the height of the ridge of the first rolled screw is also changed, so that it is necessary to delicately change the position of the subsequent second rolling die.

Therefore, the first rolling die and the second rolling die described above are used.
In the case where the rolling die and the rolling die are continuous and integrated, it is difficult to roll a thread having a desired shape with high accuracy, which may lead to deterioration of product quality and yield.

[0017]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to roll a self-locking bolt having a slit along the crest of a screw thread with high precision and efficiency, and improve product quality. It is an object of the present invention to provide a manufacturing apparatus capable of improving yield.

[0018]

According to the present invention, the object is to provide a lead in a manufacturing apparatus for rolling a self-locking bolt having a self-locking screw portion in which a slit is formed along the crest of a thread with a flat die. A first flat die for forming a multi-thread screw therein, and a thread having the same lead as the above-mentioned multi-thread screw, engaged with the thread grooves at a constant number of thread grooves to aggregate a plurality of thread threads into one thread thread. This is achieved by a device for manufacturing a self-locking bolt, characterized in that the two flat dies are held on a common die holding table so that their relative positions can be adjusted.

The relative positions of the first flat die and the second flat die may be adjustable in one of the rolling direction and the direction orthogonal thereto, or may be adjusted in a plurality of directions at the same time. . Further, at least one of them may be adjustable in the direction in which the bolt material is sandwiched.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a plan view showing an essential part of an embodiment of the present invention, and FIG. 2 is an exploded perspective view with a part thereof broken away. In these drawings, reference numeral 50 is a fixed-side die holding table,
It is fixed to a base not shown. Reference numeral 52 denotes a movable side die holding base, which horizontally moves in parallel to the fixed side die holding base 50.

Both the die holding bases 50 and 52 are standing portions 50a and 52a parallel to the moving direction of the movable side die holding base 52.
And horizontal portions 50b and 52b extending from the lower edges of the upstanding portions 50a and 52a in the directions opposite to each other. Positioning blocks 54 and 56 are mounted on the horizontal portions 50b and 52b. One end surface of each of the blocks 54 and 56 is in contact with the upright portions 50a and 52a.

Reference numerals 58 and 60 denote the first die and the second die on the fixed side.
It is a dice. These are rectangular parallelepipeds, one surface of which is in contact with the block 54, and the other surfaces 58a and 60a thereof slightly project from the horizontal portion 50b of the stationary die holding base 50. These surfaces 58a and 60a are respectively shown in FIG.
(B) and FIG. 5 (B), double thread screw type parts 18 and 1
A die blade having the same shape as that of the thread form 24 is formed.

A guide block 62 having a substantially triangular shape is fixed to one end of the block 54 so as to regulate the movement of the first die 58 in the horizontal direction (leftward in FIGS. 1 and 2).
The dies 58 and 60 are separately fixed by fixing claws 64 and 66. That is, on the upper surface of the block 54, from the lower surface of the horizontal portion 50b to the horizontal portion 50b and the block 5
Two bolts 68 and 70 project upward through 4 and the fixing claws 64 and 66 are inserted into these bolts 68 and 70, and are firmly fixed by nuts 72 and 74. Here, the tips of the fixing claws 64 and 66 extend to the upper surfaces of the dies 58 and 60, and press and fix the dies 58 and 60.

Similarly, the left side end of the movable block 56 is bent at a right angle, the corner is positioned at the inner corner of the right angle, and the second die 76 is located on the right side of the second die 76.
Is fixed. These first and second dice 78, 7
Reference numeral 6 is a pair with the first and second dies 58 and 60 on the fixed side. That is, one end surface of these is slightly projected from the horizontal portion 52b, and a die blade that is inclined in a direction opposite to the die blades of the dies 58 and 60 is cut on this surface.

These dies 76 and 78 are used for the fixing claw 8
It is fixed by 0 and 82. That is, these fixing claws 8
Nos. 0 and 82 are inserted from above into bolts 84 and 86 penetrating the block 56 from below the horizontal portion 52b, and nuts 88 and 9 are provided.
It is firmly fixed by 0. In this state, the fixing claw 80,
One end of 82 presses and fixes the upper surfaces of the dies 76 and 78.

In FIG. 1, reference numeral 92 is a bolt material supply passage provided adjacent to the fixed die holding base 50, and 94 is a bolt material extruding pin. As described with reference to FIG. 4, the bolt material 10 has the bolt shaft portion 12 and the bolt head 14, and the bolt material 10 is the first die in a state where the bolt head 14 is locked to the upper edge of the supply passage 92. It is sent to the vicinity of the corner of the rolling start side of 58 (left side in the figure).

At the start of rolling, the movable die holding table 52
Is on the left side of the position of FIG. 1, and the vicinity of the right corner of the first die 78 faces the vicinity of the left corner of the fixed-side first die 58. In this state, the bolt material extruding pin 94 extrudes the bolt material 10 between the dies 58 and 78.

When the movable side die holding base 52 moves to the right in the figure, the bolt material 10 is first moved to the first die 5.
The double threaded portion 20 shown in FIG.
Is rolled. If the movable side die holding base 52 moves further in the same direction, the second dice 60 and 78 are used to move the dice holding base 52 as shown in FIG.
The single thread screw portion 26 shown in (A) is rolled. Then, the completed bolt is discharged to the right end in the figure.

In order to adjust the relative positions of the dies 58 and 60, the nuts 72 and 74 are loosened slightly and the dies 58 and 60 are adjusted.
Should be moved. At this time, the gap 9 between the dies 58 and 60
When a gap adjusting shim (not shown) is sandwiched in 6, both dies 58, 60 can be formed by changing the thickness of the shim.
The relative position in the rolling direction of can be adjusted.

To adjust the relative positions of the dies 58 and 60 in the vertical direction, the thickness of the shim sandwiched between the dies 58 and 60 and the horizontal portion 50b of the holding table 50 may be changed. Again dice 5
In order to adjust the protruding amount of the die blades 8 and 60, the thickness of the shim sandwiched between these dies 58 and 60 and the rising portion 50a may be changed.

When the shim is used as described above, the relative positions of the dies 58 and 60 can be easily adjusted by changing the thickness of the shim. Also, the movable dies 76, 7
The relative position adjustment of No. 8 may be performed in exactly the same manner by the shims sandwiched in the gap 98 between the dies 76 and 78.

The relative positions of the dies 58, 60 and 76, 78 can be easily adjusted by using shims as described above, but the present invention is not limited to this. FIG. 3 is a partial perspective view showing another adjusting mechanism.

In FIG. 3, reference numerals 100 and 102 denote adjusting screws, which horizontally penetrate the second die 60 on the fixed side from the outside (right side), and the tip thereof abuts the side surface of the first die 58. . Therefore, by rotating these screws 100 and 102 from the outside with a screwdriver, the relative positions of the dies 58 and 60 in the rolling direction can be adjusted. Dice 5 as well
Needless to say, screws (not shown) may be provided to adjust the position of 8, 60 in the vertical direction or the protruding direction.

Although FIG. 3 shows only the fixed side, it goes without saying that the movable side can be similarly configured. In FIG. 3, the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals, and the description thereof will not be repeated. The above embodiment is the first
Since the double thread is formed by the rolling of No. 2, a bolt having one groove 28 (see FIG. 7B) at the top of the screw is made in the second rolling.

[0035]

As described above, according to the first aspect of the present invention, the relative positions of the first die and the second die can be adjusted. Therefore, a slight change in the material and diameter of the bolt material, Even if the dies are worn out, the relative position of each die is finely adjusted so that the self-locking bolt having the slits along the thread can always be rolled with high accuracy and efficiency. Therefore, the quality of the product is improved and the yield is improved.

Here, the first and second dies can be adjusted in relative position in the rolling direction (claim 2), but may be adjusted in other directions. For example, the bolt material may be adjusted in a direction orthogonal to the rolling direction without changing the interval in the sandwiching direction (claim 3), or may be adjustable in a direction facing the bolt material. The adjustment may be made in two or more directions among these three directions.

[Brief description of drawings]

FIG. 1 is a plan view showing a part of an embodiment of the present invention.

FIG. 2 is an exploded perspective view in which a part is also broken.

FIG. 3 is a perspective view showing another embodiment.

FIG. 4 is a view showing a bolt and a die by the first rolling in the conventional method.

FIG. 5 is a diagram showing a bolt and a die by the same second rolling.

[Figure 6] Similarly, a development view of a multi-thread (two-thread) screw

FIG. 7 is an enlarged view of the same manufacturing process.

FIG. 8 is a diagram showing a nut tightened state.

[Explanation of symbols]

 10 Bolt material 50, 52 Die holding base 58, 78 First die 60, 76 Second die 64, 66, 80, 82 Die fixing claw 96, 98 Gap between the shims for spacing

Claims (3)

[Claims] 1. A manufacturing apparatus for rolling a self-locking bolt having a self-locking screw portion in which a slit is formed along the crest of a screw thread with a flat die, wherein a multiple thread is formed in a lead. One flat die and a second flat die for engaging a plurality of thread grooves with the same lead as the above-mentioned multi-thread screw and assembling a plurality of thread threads into one thread thread are common. A device for manufacturing a self-locking bolt, which is held on a die holding table so that its relative position can be adjusted. 2. The apparatus for manufacturing a self-locking bolt according to claim 1, wherein the first flat die and the second flat die are held by a common die holding table such that their relative positions can be adjusted in the rolling direction. 3. The self-locking bolt according to claim 1, wherein the first flat die and the second flat die are held by a common die holding table so that their relative positions can be adjusted in a direction orthogonal to the rolling direction. apparatus.