JPH09280229A - Fastener - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent cracking and breakage of a thread bottom part of a bolt and a nut by providing a trapezoidal thread bottom part of the bolt and the nut, providing roundness at each corner, and providing a trapezoidal thread ridge part of the bolt and the nut. SOLUTION: This fastener is made by screwing a bolt 7 of the thread in which a bottom part 8a of a male screw 8 of a bolt 7 is trapezoidal, roundness 8c is provided on each corner, and a ridge part 8b of the male screw is trapezoidal, into a nut 9 in which a bottom part 10a of a female screw 10 is trapezoidal, roundness 10c is provided at each comer, and a ridge part 10b of the female screw is trapezoidal, and because the thread bottom part of the bolt 7 and the thread bottom part of the nut 9 are trapezoidal (with roundness at each corner), the fastener can withstand the vibration for a long time, and cracks of the thread bottom part of the bolt 7 and the nut 9 can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fastener for bolts and nuts for fixing industrial parts and members.

[0002]

2. Description of the Related Art A conventional bolt and nut are provided with a roundness C at the tip of a triangular thread root of the male thread G shown in FIG.
The tip of the triangle that is the ridge portion of the triangle is rounded at the tip of the triangular thread trough of the bolt B and the female thread H where the ridge portion D is provided by chamfering.
Of the fastener (FIG. 2 is an overall view of the bolt B and the nut A of FIG. 1 with the washer 4a added) capable of screwing with the nut A provided with the trapezoidal thread portion F. Products of various sizes were manufactured by a thread cutting rolling machine or a forging method.

[0003]

When the bolt B and the nut A, which are the fasteners of the prior art described above, are used in an aircraft, the thread trough portion C of the bolt B is cracked by the vibration of the aircraft and the bolt is cut. There is a problem in that a crack is formed along the thread root E of the nut A and the thread root of the nut is cracked.

The present invention is intended to solve such problems of the prior art, and an object of the present invention is to provide a fastener for preventing cracks, cracks, and cuts in thread troughs of bolts and nuts. Is what you are trying to do.

[0005]

In order to solve the above-mentioned problems, a fastener according to the present invention has trapezoidal thread roots of the bolt and nut and rounded corners, and also has a trapezoidal thread portion of the bolt and nut. Use

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Since the present invention has the above-mentioned means, since the thread troughs 8a of the bolt and the thread troughs 10a of the nut shown in FIGS. 14 and 15 are trapezoidal, the fastener of this thread is applied to the aircraft. When used Prevents cracks in screw troughs due to aircraft vibration.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an enlarged view of the engagement portion of a conventional bolt and nut, in which the thread trough C of the bolt B and the thread trough E of the nut A are rounded. FIG. 2 is a fastener for the threads of the bolt B and nut A of FIG.

FIG. 3 shows a bolt 2 having a trapezoidal trough portion 3a of an external thread 3 of a bolt 2 and rounded portions 3b at both corners thereof, and chamfering a triangular tip which is a ridge portion of the external thread. The valley portion of the female screw 5 is a portion to be screwed with a nut having a trapezoidal thread portion 5b in which a rounded portion 5a is provided at the tip of the triangular thread valley portion, and the thread angle is about 60 degrees in the conventional case. And (and including screws with a thread angle of 5 to 120 degrees), the trapezoidal root 3b of the male thread 3 and the trapezoidal portion of the thread 5b of the female thread 5 should also have an appropriate width. FIG. 4 shows a fastener of the threads of the bolt 2 and the nut 4 shown in FIG. 3 in which the threads (the male thread 3 and the female thread 5) have a height and can be engaged.

The tap shown in FIG. 5 of FIG. 6 is the tap 13 of the present invention having the shape of the thread of the bolt 2 shown in FIG. 3, and a threaded embodiment of the tap 13 will be explained. Use a drill (set the drill on the drilling machine and switch on the power supply) to make a hole that is slightly wider than the diameter of the cross screw 16, and then similarly drill on the strip plate 19 for the thread trough portion of the cross screw 16 ~ screw. Drill a hole in the width of the trough and cross screw 1
Set the tap 13 of the screwable size 6 on the tapping board, switch on the power supply and tap the hole of the strip 19 1
The female screw is cut with 3, and the washer 17 is fitted to the cross screw 16, inserted into the hole of the strip plate 18, and tightened to the female screw of the strip plate 19 with a cross screwdriver and fixed as shown in FIG.

The die shown in FIGS. 9 and 10 is the die 20 of the present invention having the shape of the thread of the nut 4 shown in FIG. 3. An example using the die 20 will be described. An alloy faucet semi-finished product will be described. 22 is attached to the rotary shaft side of the lathe, a bite and a drill are also attached at corresponding predetermined positions, and the die 20 is set at another predetermined position, and then the power source of the lathe is turned on to rotate the semi-finished product 22 of the faucet. The outside of the external thread of the faucet semi-finished product 22 is roughly cut with a bite (the hollow portion on the inner side is roughly cut with a drill), and then the external thread 22 is cut with a die 22 to finish as shown in FIGS. 12 and 13.

In FIG. 14, the trough portion 8a of the male screw 8 of the bolt 7 is trapezoidal, and rounded portions 8c are provided at both corners of the trough portion 8b.
With trapezoid and rounded corners 10c at both corners
0b is a trapezoidal nut 9 and the thread angle is about 60 degrees (and the thread angle is 5 degrees ~
(Including trapezoidal screws with a width of up to 120 degrees) Trapezoidal thread troughs 8a and trapezoidal thread crests 8b of the external thread 8 and the internal thread 9
The trapezoidal thread root 10a and the trapezoidal thread part 10b also have an appropriate width, and the thread (male thread 8 and female thread 10)
FIG. 15 shows a fastener of the screw threads of the bolt 7 and the nut 9 of FIG.

The tap 24 shown in FIGS. 16 and 17 is shown in FIG.
18 is a tap 24 of the present invention in the shape of the thread of the bolt 7, and a threading embodiment of the tap 24 will be described. A drill is set on an iron strip plate 29 shown in FIG. Insert a hole with a width slightly larger than the diameter of the cross screw 27, and similarly, drill a hole in the strip 30 with a width of the thread valley of the cross thread 27 to the thread valley part. The tap 24 is set on the tapping board, the power switch is turned on, the tap 24 is used to cut the female screw, and the cross screw 27 is fitted with the washer 28 and the hole of the strip 29 is inserted. Tighten the female screw with a cross screwdriver and fix it as shown in Fig. 19.

The die shown in FIGS. 20 and 21 is the die 31 of the present invention having the shape of the thread of the nut 9 shown in FIG.
Explaining an embodiment using a die 31, a semi-finished product 33 of an alloy faucet is attached to the rotary shaft side of a lathe, a bite and a drill are also attached at corresponding predetermined positions, and the die 31 is set at another predetermined position. After turning on the power of the lathe, the semi-finished product 33 of the faucet is rotated, and the outside of the male screw of the semi-finished product 33 of the faucet is roughly cut with a bite (the hollow part on the inner side is roughly cut), and then the male screw 34 with the die 31. Cut and finish as shown in FIGS. 23 and 24.

[0014]

Since the present invention is configured as described above, the following effects can be obtained.

Since the thread troughs 3a of the male thread 3 of the bolt 2 according to claim 1 are trapezoidal and rounded at both corners thereof, the thread troughs 3a of the bolt 2 are used when the present fastener is used in a machine tool or the like. Since it has a trapezoidal shape, it is possible to prevent cracks in the thread roots of the bolt 2 due to vibration. (And the tap 13 of claim 3 is a tool for finishing the internal thread of the nut 4 shown in FIG. 3, and the die 20 of claim 4 is the bolt 2 shown in FIG.
It is a tool for cutting male threads. )

The trough portion 8a of the male screw 8 of the bolt 7 of claim 2
Is trapezoidal and has rounded corners 8c at both corners.
The root 10a of the female screw 10 is trapezoidal and rounded at both corners 1
Since 0c is provided, when this fastener is used in an aircraft or bridge girder, the thread troughs 8a of the bolt 7 and the thread troughs of the nut 9 are trapezoidal due to vibration, so cracks in the thread troughs of the bolt 7 and the nut 9 are cracked. You can prevent it. (The tap 24 of claim 5 is a tool for finishing the internal thread of the nut 9 shown in FIG. 14, and the die 31 of claim 6 is a tool for finishing the external thread of the bolt 7 shown in FIG. 14.)

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a conventional screw engaging portion.

2 is a side view of the thread fastener of FIG. 1. FIG.

FIG. 3 is an enlarged cross-sectional view of a screw engaging portion used in the present invention.

4 is a side view of the thread fastener of FIG. 3. FIG.

FIG. 5 is a side view of the tap used in the present invention.

FIG. 6 is a front view of the tap shown in FIG.

FIG. 7 is a perspective view of performing work using the tap of the present invention shown in FIG.

FIG. 8 is a cross-sectional side view showing the completion of mounting the cross screw.

FIG. 9 is a cross-sectional view of a die used in the present invention.

FIG. 10 is a perspective view of the die of FIG.

FIG. 11 is a side view of a semi-finished faucet product.

FIG. 12 is a sectional side view in which a semi-finished faucet product is also thread-cut.

FIG. 13 is a view of the semi-finished product of the faucet of FIG. 12 as viewed from the back side.

FIG. 14 is an enlarged cross-sectional view of a screw engaging portion used in the present invention.

FIG. 15 is a side view of the thread fastener of FIG.

FIG. 16 is a side view of the tap used in the present invention.

FIG. 17 is a front view of the tap of FIG.

FIG. 18 is a perspective view of performing work using the tap of the present invention shown in FIG. 16.

FIG. 19 is a cross-sectional side view showing the completion of mounting the cross screw.

FIG. 20 is a sectional front view of a die used in the present invention.

FIG. 21 is a perspective view of the die of FIG. 20.

FIG. 22 is a side view of a semi-finished faucet product.

FIG. 23 is a sectional side view of the same semi-finished faucet which is thread-cut.

FIG. 24 is a view of the semi-finished product of the faucet of FIG. 23 as viewed from the back side.

[Explanation of symbols]

 1 Fasteners 2 Bolts 3 Male threads 3a Thread roots 3b Roundness 3c Thread ridges 4 Nuts 5 Female threads 5a Thread ridges 5b Thread ridges 6 Fastenings 7 Bolts 8 Male threads 8a Thread ridges 8b Thread ridges 8c Roundness 9 Nut 10 Female thread 10a Thread root 10b Thread ridge 10c Roundness 11 Washer 12 Washer 13 Tap body 14 Groove 15 Thread ridge 16 Cross screw 17 Washer 18 Strip plate 19 Strip plate 20 Dice body 21 Thread ridge 22 Faucet (semi-finished product) ) 23 screw thread portion 24 tap body 25 groove portion 26 screw thread portion 27 cross screw 28 washer 29 strip plate 30 strip plate 31 die body 32 screw thread portion 33 faucet (semi-finished product) 34 screw thread portion A nut B bolt C screw valley portion D Thread ridge E Thread ridge F Thread ridge G Male thread H Female thread K Washer

Claims (6)

[Claims] 1. A bolt 2 and a female screw in which a trough portion 3a of a male thread 3 of a bolt 2 is trapezoidal and rounded 3b is provided at both corners thereof, and a triangular tip which is a mountain portion of the male thread is chamfered to provide a mountain portion 3c. 5
A fastener which can be screwed with a nut 4 provided with a rounded portion 5a at the tip of a triangular threaded portion and a trapezoidal threaded portion 5b. 2. A trough portion 8a of a male thread 8 of a bolt 7 is trapezoidal, and rounded portions 8c are provided at both corners of the trough portion 8b. A fastener which is provided with rounded portions 10c at both corners thereof and can be screwed with a trapezoidal nut 10b of a female screw. 3. A tap in the form of a thread of the bolt 2 according to claim 1. 4. A die having a thread shape of the nut 4 according to claim 1. 5. A tap in the form of a thread of the bolt 7 according to claim 2. 6. A die having a thread shape of the nut 9 according to claim 2.