JP2002147425A - Full thread bolt and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bolt capable of surely fastening even a thin member, and performing a tight fastening with an opponent member, similar to such as a wet preventing bolt and a masking bolt for female screw protection. SOLUTION: An incomplete thread 5A of an end 51A of an under head screw part 5 of a head 2 of the bolt 1 is made to be minimum, and a knotting part 14A is formed contiguous to the end 51A. Accordingly, a nut 8 threadedly engaged to the under head of the bolt 1 is guided to immediately before or to be in close contact with the under head of the head 2 of the bolt 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which when a nut is completely screwed, a gap between the nut under the head of the bolt and the nut is zero.
It relates to a full thread bolt having a pitch of 0.5.

[0002]

2. Description of the Related Art In order to fasten a member thinner than one pitch of a screw portion with a bolt and a nut, it is necessary to provide a screw portion of a shaft portion just below a head neck. Until it must be processed with a rolling die. Further, when the nut is completely screwed into the bolt, the gap between the nut under the head of the bolt and the nut becomes zero, and a bolt (for example, a plug bolt for preventing leakage, a masking bolt for protecting a female screw, etc.) which is tightly fastened to a member is manufactured. in case of,
It is necessary to form a tying portion by cutting in advance to just below the neck of the bolt head, and then to form a threaded portion by threading with a rolling die.

[0003]

However, when a rolling die is used to machine a bolt just below the neck of the bolt, the bolt head may interfere with the rolling die and chip the die. In addition, in the case of a rolled die in which the thread is cut into a taper to prevent chipping, the thread is machined so that the gap between the bottom of the head and the end of the thread on the shaft is 0.5 pitch or less. It was generally impossible to do so. Further, forming a threaded portion by rolling after forming a tie portion by cutting in advance has a problem that it takes time and cost as much as the cutting process is inserted.

[0004]

According to the present invention, as a means for solving the above-mentioned conventional problems, a screw portion is provided on a head (2) and a peripheral surface.
(5) at the end of the screw head (51A) under the head (2) and the neck (5A) to provide a full screw bolt (1) with a minimum incomplete screw (5A). Is what you do. The incomplete thread portion (5A) of the screw terminal portion (51A) is in the range of 50 ° to 180 °, and when the nut (8) is completely screwed, the head (2)
It is desirable that the gap S between the nut and the nut (8) is within 0.5 pitch. Further, the head (2) under the neck and the screw terminal (51
Between A), it is desirable that a connecting portion (14A) having the same diameter as the thread root diameter d is formed continuously with the screw end portion (51A), and the incomplete thread of the screw end portion (51A) is formed. Part (5A) is 50 °
~ 180 ° and the width of the tie (14A) is 3m
m, and when the nut (8) is completely screwed, the gap S between the head (2) and the nut (8) is desirably 0 to 0.5 pitch. The bolt (1) is provided with a thread part forming oblique groove (11) on the rolling surface (10), and the thread part forming oblique groove is provided.
The shaft of the bolt body (1A) consisting of the head (2A) and the shaft (3A) is formed by a rolling die (9) that minimizes the formation of incomplete thread at the end (11A) of (11). Manufactured by rolling threaded part (5) into part (3A). In addition, the bolt (1) is
(10) is provided with an inclined groove (11) for forming a thread portion, the incomplete thread portion forming portion at the terminal end (11A) of the inclined groove (11) for forming a thread portion is minimized, and the pre-processing taper is formed. Forming part (13) and a connecting part forming part (14) having the same diameter as the thread root diameter d continuously provided at the end part (11A) of the thread part forming oblique groove (11). dice
(9) Bolt body consisting of head (2A) and shaft (3A)
It is manufactured by rolling a screw portion (5) and a tie portion (14A) on a shaft portion (3A) of (1A).

[0005]

[Operation] Since the bolt (1) of the present invention minimizes the incomplete thread part (5A) at the screw terminal part (51A) under the head (2) and neck, the thread sharply rises to a complete thread, In this case, the thread root diameter d is such that the nut (8) screwed to the bolt (1) can be guided to the end of the imperfect thread (5A). Further, the head (2) under the neck and the screw terminal (51
If a connecting portion (14A) having the same diameter as the thread root diameter d is continuously formed between the screw end portions (51A) between the bolts (1)
When the nut (8) is completely screwed into the
A) guides the nut (8) so that the clearance S between the head (2) and the neck of the bolt (1) and the nut (8) can be 0 to 0.5 pitch.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. The present invention will be described with reference to an embodiment shown in FIGS. 1 to 7. The bolt (1) shown in FIG.
A shaft (3), and a shaft (3) protruding from a tip of the shaft (3).
The guide boss (4) has a smaller diameter than that of the guide boss (4) .A thread (5) is provided on the peripheral surface of the shaft (3), and a guide screw groove (4) is provided on the peripheral surface of the guide boss (4). 6) is provided. Further, the end surface of the guide boss (4) is a concave curved surface (7).

[0007] In the screw (5) of the shaft (3), the head
(2) The divergence angle θ of the imperfect thread portion (5A) of the screw terminal portion (51A) under the neck is minimized in the range of 50 ° to 180 °.
In the present embodiment, θ is set to 90 ° as shown in FIG.

When the nut (8) is screwed into the bolt (1), the guide boss (4) having the guide screw groove (6) is
Straighten the nut (8) of (1) with respect to the slant,
Prevent seizure. The thread root diameter d of the incompletely threaded portion (5A) is such that the nut (8) can be guided to the terminal end (51A) of the incompletely threaded portion (5A). As shown in FIG. 3, when the nut (8) is completely screwed, the nut (8) is located just below the neck of the head (2) of the bolt (1). In this case, the clearance S between the bottom of the head (2) of the bolt (1) and the nut (8) is equal to the pitch of the threaded portion (5).
It becomes 0.2 mm to 0.4 mm within 5 (0.5 pitch).

To manufacture the bolt (1), FIGS.
Use the rolling dies (9) shown in (1). The die (9) is composed of a fixed die (9A) and a moving die (9B), and each die (9A,
The thread forming surface (10) of 9B) has a thread groove forming groove (1
1), a large number of the dies (9A, 9B) are provided above the dies (9A, 9B) as shown in FIGS. 5 (a) and 6 (a).
9B) is tapered from the upper front end to the upper rear end. As shown in FIG. 7, the terminal end (11A) of each inclined groove (11) at the upper end of the die (9A, 9B) is a minimum incomplete thread forming portion. The width W of the dies (9A, 9B) is 20 mm in this embodiment.

The dies (9A, 9B) are arranged with their rolling surfaces (10) facing each other, and as shown in FIGS. 4 and 5 (a) and (b), the bolt body (1A) and the dies (9 9A, 9B), the bolt body (1A) must be
The movable die (9B) is supplied from the side having the larger taper between (9A, 9B) and is moved in the direction of the arrow to the position shown in FIGS. In this case, the head (2A) of the bolt body (1A)
A gap S between the lower part of the neck and the upper edge of the die (9) is provided at 0.2 mm to 0.4 mm within 0.5 pitch.
The interference between the head (2A) of A) and the dice (9) is prevented.

The end of the thread (5) of the shaft (3) of the bolt (1) is raised from the position shown by the arrow a in FIG.
The incomplete thread portion (5A) of (A) is rolled by the minimum incomplete thread portion forming portion which is the end portion (11A) of the inclined groove (11) of the die (9), and the incomplete thread portion (5A) is formed. ) Is 50 ° -18
The range is 0 °. As described above, FIG.
At the position shown in (b), a screw (5) is rolled on the shaft (3A) of the bolt body (1A) to produce the bolt (1).

FIGS. 8 to 13 show another embodiment.
In the present embodiment, in comparison with the embodiment shown in FIGS. 1 to 7, a bolt (1) having the same diameter as the thread root diameter d is provided between the head (2) under the neck and the screw terminal (51A). Connection part (14A) is screw end
(51A).

As shown in FIG. 9, a nut is attached to the bolt (1).
When (8) is completely screwed, the nut (8) is
The head of (1) is located just before or close to the neck of (2). In this case, the gap S between the bottom of the head (2) of the bolt (1) and the nut (8) is within 0 to 0.5 (0.5 pitch) of the pitch of the threaded portion (5). 0 mm to 0.8 mm.

In order to manufacture the bolt (1), a rolling die (9) shown in FIGS. 10 to 13 is used. The dice (9)
Fig. 1 shows the rolling die (9) shown in Figs.
As shown in (a) and (b), from the upper front end to the upper rear end of the dies (9A, 9B), up to about one-third of the dies (9A, 9B) are closer to the upper front end, and about two-thirds of the tying portion (14A) are used. A pre-formed tapered portion forming portion (13) having twice the width is formed, and FIG.
As shown in (b), a joining portion forming portion (14) is formed in a portion of the dice (9A, 9B) from the upper front end to the upper rear end, which is closer to the upper front end than about one-third. As shown in FIG. 13, the connecting portion forming portion (14) is provided continuously to the end portion (11A) of the thread groove forming oblique groove (11).

When the bolt (1) is manufactured, the dies (9A, 9B) are arranged with the rolling surface (10) facing the same as in the previous embodiment, and FIGS. 10 and 11 (a). As shown in (b) and (b), the bolt body (1A) is supplied between the dies (9A and 9B), and the movable die (9B) is moved in the direction of the arrow in FIGS.
Move to the position shown in (b). At this time, the die (9
(A, 9B), the pre-work taper portion (13A) is formed in the bolt body (1A) by the pre-work taper portion forming portion (13). The head (2A) can be released from under the neck toward the shank (3A), and subsequently the tying part (14) is continuously formed by the tying part forming part (14).
(A) is formed, so that when the end (11A) of the inclined groove (11) forms the screw end (51A) of the incomplete thread (5A), it absorbs the excess thickness generated during the formation. This causes the thread to rise sharply to a complete thread.

FIG. 14 shows still another embodiment of the present invention.
This embodiment differs from the embodiment shown in FIGS.
From the middle to the tip of the bolt shaft (3), screw body
(51), and a threaded part under the neck (52) from under the neck of the head (2)
Is provided. And the end portion (5
The screw thread rises sharply while minimizing the incomplete thread part (52A) of 21A), and the washer (12) fitted under the neck of the head (2) is the end of the thread part under the neck (52). The washer (12) is prevented from falling off by preventing it from digging into the part (521A).

FIG. 15 shows still another embodiment of the present invention. In this embodiment, as compared with the embodiment shown in FIGS. 8 to 13, the bolt shaft (3) is provided with a screw main body (51) from the middle to the tip, so that the head (2) is under the neck. From below is provided a screw portion (52) under the neck. The screw thread rises rapidly with the incomplete thread part (52A) of the end part (521A) of the thread part under the neck (52) as a minimum, and a washer fitted under the neck of the head part (2). (12)
Does not bite into the terminal end (521A) of the screw portion (52) under the neck to prevent the washer (12) from falling off.

As shown in FIG. 16, in the conventional bolt (1), an incomplete screw portion at the end portion (531A) of the screw portion under the neck (53) is used.
If (53A) is not the minimum and the thread is gently rising, the washer (12) is more likely to bite into the terminal end (531A) of the threaded portion under the neck (53).

In the above embodiment, when the bolt (1) is manufactured, if the rolling position of the bolt body (1A) with respect to the rolling dies (9A, 9B) is adjusted up and down, the bolt head (2) and the neck The gap S between the nut and the nut (8) can be adjusted. When manufacturing bolts (1) that securely fasten thin members, it is desirable to roll the product under the minimum clearance conditions that can prevent damage to the bolt head (2) and chipping of the die. . If the nut (8) is chamfered at the inner peripheral end, when the bolt (1) is completely screwed into the nut (8), the chamfered portion is bolted to the nut (8). The gap S between the bolt head (2) neck and the nut (8) can be reduced to zero by preventing interference with the nut (8). Since the bolt (1) can be tightly fastened to the member, it can be used, for example, as a bolt for preventing leakage or a bolt for protecting a female screw.

In addition to the above embodiment, the guide boss of the bolt (1) is not essential, and the head may have a hexagonal shape or a round shape, or may have a flange at the lower part of the head. Alternatively, the bolt (1) may be screwed into a female screw hole provided in a part other than the nut.

[0021]

According to the present invention, the incomplete thread portion at the screw terminal portion below the neck of the bolt head is minimized, and the tie portion is formed continuously at the screw terminal portion. The nut to be screwed into the bolt has a diameter that is guided to the end of the incompletely threaded portion of the bolt and the tying portion. Between 0 and 0.5 pitch. Therefore, in the present invention, even a thin member can be securely fastened. Further, since the bolt can be tightly fastened to the member, it can be used as, for example, a bolt for preventing leakage or a bolt for protecting a female screw. Further, in the present invention, the screw thread is rapidly raised to the complete screw thread by minimizing the incomplete screw portion at the screw end portion, so that the washer fitted to the bolt can also be securely prevented from falling off. .

[Brief description of the drawings]

 1 to 7 show one embodiment of the present invention.

FIG. 1 is a side view of a bolt.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a side view of the bolt in a nut screwed state.

FIG. 4 is a plan view of a rolling die rolling surface.

FIG. 5 (a) Rolling start state plan view (b) Rolling start state front view

FIG. 6 (a) Rolling finished state plan view (b) Rolling finished state front view

FIG. 7 is a detailed view of an inclined groove end portion.

FIG. 8 is a side view of a bolt according to another embodiment.

FIG. 9 is a side view of a bolt in a nut screwed state according to another embodiment.

FIG. 10 is a plan view of a rolling die rolling surface of another embodiment.

FIG. 11 (a) Rolling start state plan view in another embodiment (b) Rolling start state front view in another embodiment

12A is a plan view of a finished rolling state in another embodiment. FIG. 12B is a front view of a finished rolling state in another embodiment.

FIG. 13 is a detailed view of an end portion of an oblique groove according to another embodiment.

FIG. 14 is a side view of a bolt according to still another embodiment.

FIG. 15 is a side view of a bolt according to still another embodiment.

FIG. 16 is a side view of a conventional end portion of a screw portion under a neck.

[Explanation of symbols]

 1 Bolt 1A Bolt base 2,2A Head 3,3A Shaft 5 Screw 5A, 52A Incomplete thread 51A, 521A Screw end 8 Nut 9 Rolling die 10 Rolling surface 11 Bevel groove 11A (End of groove) 12 Washer 13 Pre-formed taper portion 13A Pre-processed tapered portion 14 Tie-in portion 14A Tie-in portion 52 Thread under neck 53 Thread under neck of conventional bolt 53A Incomplete bolt of conventional bolt Threaded part 531A Termination of threaded part under neck of conventional bolt

Claims (6)

[Claims] An all-threaded bolt comprising a head and a shaft having a threaded portion on a peripheral surface, wherein an incomplete threaded portion is minimized at a screw terminal portion under the head neck. 2. The incomplete thread portion of said screw terminal portion has an angle of 50 ° or less.
When the nut is completely screwed in the range of 180 °,
The bolt according to claim 1, wherein a gap between the head and the nut is within 0.5 pitch. 3. The full screw bolt according to claim 1, wherein a connecting portion having the same diameter as the thread root diameter is formed between the lower part of the head neck and the screw terminal portion so as to be continuous with the screw terminal portion. 4. The incomplete thread portion of said screw terminal portion has an angle of 50 ° or more.
4. The range of 180 °, the width of the tying portion is 3 mm or less, and the gap between the head and the nut is 0 to 0.5 pitch when the nut is completely screwed. 5. Full thread bolt 5. A head having a thread forming diagonal groove provided on a rolled surface, wherein the incomplete thread part forming part at the terminal end of the thread forming diagonal groove is minimized. 3. The method according to claim 1, wherein a thread portion is rolled on a shaft portion of the bolt body composed of a bolt and a shaft portion. 6. The thread forming surface is provided with a thread forming diagonal groove, the incomplete thread forming part at the terminal end of the thread forming diagonal groove is minimized, and a pre-process taper part forming part is formed. A shaft part of a bolt body composed of a head and a shaft part by a rolling die provided with a tie part forming part having the same diameter as the thread root diameter continuously at the end of the thread part forming oblique groove. 5. The method for manufacturing a full screw bolt according to claim 3, wherein the threaded portion and the tie portion are rolled.