JPS62242113A - Locking elastic screw part and thread chaser thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention provides a method for preventing loosening of threaded components such as hexagonal bolts, hexagonal nut stud bolts, machine screws, and set screws. The present invention relates to a locking screw component characterized by having two screws, and a thread cutting tool therefor.

Conventional technology Conventionally, methods for preventing loosening of threaded parts include A> Mechanically fixing the bolt or nut, a, using a bending washer, and using a C0 grooved hexagonal nut using a lock wire. , Using a nut with teeth on the bearing surface of the nut e, Adding processing to the bolt or nut and screwing in a set screw B
〉 Maintaining the contact state between the threads after tightening a, Using a spring washer, Using a double nut C〉 Deforming the thread a, Providing a thin cylindrical part on a part of the nut and tightening Afterwards, this cylinder is deformed into an oval shape, etc., and the threads of the nut are caulked.C2: A nut that deforms during tightening is used.D>A combination with a soft material such as nylon fixed between the threads of the nut. E〉 There are many ways to do this, such as applying adhesive to the threads and then tightening them.

Problems to be Solved by the Invention By the way, with such conventional methods of preventing screws from loosening, for example, the method of using a bending washer in A> and a above cannot be used unless there is a place to bend the tongue. 〉,b
The method of using a lock wire is laborious, and the method of using a grooved hexagonal nut (A) and C requires adjustment to align the groove of the nut with the bottle hole of the bolt. The method of using a nut with teeth on the bearing surface of the nut shown in A> and d does not damage the contact surface of the other party when tightening, or the bolt or nut shown in A> and e may be modified to create a set screw. Both methods have quite a few drawbacks, such as the method of screwing in, which makes it difficult to reuse once disassembled.

When it comes to loosening of threaded parts, there are two types of looseness: when the bolt or nut, or both, loosen due to rotation, and when the bolt or nut loosens even though they do not rotate. Most of the methods for preventing loosening can be said to be the former method, that is, methods that prevent bolts, nuts, or both from rotating and loosening.

This invention is applicable not only to the former case, but also to the latter case, that is, when a bolt or nut loosens without rotating, for example, when the article being fastened (object to be fastened) is deformed or loses its elasticity. To propose a new threaded part and its thread cutting tool that will prevent the screw from loosening due to rotation of the bolt or nut.

Means to solve problems The present invention will be explained below based on the drawings.

In FIG. 1 showing a bolt (male thread) 1 represented by a male thread, the shaft portion of the bolt consists of a reference male thread portion 2 and a fully dependent male thread portion 3, and the outer diameter of the fully dependent male thread portion d2≦ Form a male thread that satisfies the following: outer diameter di of the standard fully male thread -2 x thread depth rl of the standard fully male thread, and pitch p2 of the dependent fully male thread <pitch pi of the standard fully male thread. That's what I do.

Now, as the actual dimension of the bolt 1, di = 10
mm, pi = l.

5" picture, rl = o, 8mm, p2 = 1.3mm
, d2-1O-2× 0.8=8.4m, then pi
-p2 = e 1.5-1.3 = o, 2mm, that is, 0.2M of the difference in pitch between two male screws with different pitches
This makes it possible to prevent screws from loosening.

Operation A in Figure 2 shows the state in which the bolt (male thread) 1 has tightened the object to be tightened 4, and the bolt (male thread) 1 is in a state where a load is applied to the standard fully male threaded portion 2 and the dependent fully male threaded portion 3. As shown in Fig. 3, which shows an enlarged view of the mountain, a compressive force acts in the direction of the arrow from the pitch difference += pt - pl of the male threaded portion 2.3.
The elastic deformation due to this compressive force is the elastic shrinkage δ of the standard male thread.
Accordingly, the threads of the male threaded portion 2.3 and the threads of the mating female thread 5a are pressed against each other to produce a detent effect, and the technical problem is solved.

In addition, A in Fig. 5 shows a state in which the nut-shaped female screw (6) has tightened the object to be tightened (4). As shown in Fig. 6, which is an enlarged view of the state, a tensile force acts in the direction of the arrow from the pitch difference between the female threads 7 and 8 = 93-94, and the elastic deformation due to this tensile force causes the elastic elongation of the reference male thread part. γ, the threads of the female threaded portion 7.8 and the threads of the mating male thread 5b are pressed together and become a detent;
In the case of the nut 6, the same effect as in the case of the bolt 1 is produced, and the technical problem is solved.

Examples Below, as examples of the present invention, bolts representing internal male threads and nuts representing internal threads of threaded parts will be described.

In Fig. 1, a bolt (male thread) 1 has a standard fully male thread arch e and another dependent fully male threaded portion 3, which is used when cutting threads with the head of the bolt fixed on a lathe. First, in order to thread the fully dependent male thread at pitch p2, determine the ratio between the rotational speed of the bolt, which is the material to be cut, and the feed rate of the blade attached to the lathe for thread cutting, and then cut the thread of the fully dependent male thread. In order to cut threads at pitch p2 and then continuously cut threads at pitch p1 on the standard fully threaded part, the ratio between the rotation speed of the bolt, which is the material to be cut, and the feed speed of the blade attached to the lathe that performs thread cutting. Then change the position of the tip of the blade for cutting the pitch p1 of the standard complete male thread to match the thread trough when thread cutting of the pitch p2 of the dependent complete male thread is completed, and then cut the standard complete male thread. The male thread part is threaded at pitch p1. Said p
Align the tip of the blade for thread cutting 1 with the valley of the thread when the thread cutting of p2 is completed, and then
Thread cutting 1 is performed when the bolt 1 inserts the object to be tightened 4 and is screwed into the combination female thread 5a in Fig. 2, opening 1. Outer diameter d2 ≦ Outer diameter di of the reference fully male threaded portion di -2 x Thread depth rl of the reference fully male threaded portion, so the female thread of the portion of the combination female thread 5a that corresponds to the reference fully male threaded portion 2 This means that it can pass through the thread without fitting into the thread, and then smoothly fit into the female thread of the portion corresponding to the dependent fully male threaded portion 3 of 5a.

If a thread is formed by thread cutting between the dependent complete male thread part 3 and the reference complete male thread part 2 using the above procedure, the outside of the dependent complete male thread part can be Diameter d2 ≦ Outer diameter di -2 of standard complete male thread
×Thread depth rl of the standard fully male threaded portion, and pitch p2 of the dependent fully male threaded portion<touch p1 of the standard fully male threaded portion,
However, when designing the actual bolt thread (1), the tightening force in (1) is too large, causing permanent deformation of the bolt (1) beyond its elastic limit. The dimensions of d1, d2, pl, and pl must be determined so that the difference in the outer diameter of the fully male threaded portion (outer diameter d1 of the reference fully male threaded portion - outer diameter d2 of the dependent fully male threaded portion) is too small. Also, care must be taken to ensure that the bolt 1 is not unable to be tightened because the pitch difference between the fully male threaded portions (reference pitch pt of the fully male threaded portion - pitch p2 of the dependent fully male threaded portion) is too large. There is.

Incidentally, the pitch pl of the reference fully male threaded portion and the pitch p2 of the dependent fully male threaded portion each include a reference pitch specified by the JIS thread standard or the like. This is to make it clear that thread cutting can be done with a commonly used lathe. In order to cut threads by using the reference pitch specified in the thread standard for one of the pitches p1 and pl and threading the other pitch with a dimension not specified in the thread standard, In order to cut threads at a pitch that is not specified in the screw standard, it is necessary to install a thread cutting device as an accessory device on the lathe.

At the opening in Fig. 2, the bolt 1 is engaged with the tip of the fully dependent male thread 3 or the front end of the female combination thread 5a.
How to determine the tightening allowance S is to ensure that the tightening force acting on the contact surface between the bearing surface of the head of the bolt 1 and the object to be tightened 4 is sufficient, and that the standard for preventing loosening described in 1 above is completely satisfied. Male thread part 2
It depends on whether the compressive force acting between the S
It is appropriate to determine the tightening force of the bolt 1, and if the tightening force of the bolt 1 is insufficient, it may be adjusted by inserting a washer between the bearing surface of the head of the bolt 1 and the object to be tightened 4. can.

Next, in Fig. 4, the nut (female thread) 6 has a standard fully female threaded portion 7 and another dependent fully female threaded portion 8, and this will be explained using an example in which only the female thread can be cut with a lathe. For example, first, in order to be able to thread the standard perfect female thread part with pitch p3, determine the ratio between the rotation speed of the nut 6, which is the material to be cut, and the feed rate of the blade attached to the lathe for thread cutting. The rotation speed of the nut 6, which is the material to be cut, and the feed rate of the blade attached to the lathe that performs the thread cutting are set so that thread cutting can be carried out at pitch p3 of the part, and then thread cutting of pitch p4 of the fully dependent male thread part can be performed continuously. and the position of the tip of the blade for cutting the thread of the dependent fully female threaded part p4 as a reference point of the fully female threaded part p3.
After thread cutting is made to match the valley of the thread when the thread cutting is completed, thread cutting of the subordinate complete female thread part is performed at pitch p4. After aligning the tip of the blade for threading p4 with the trough of the thread when threading p3 is finished, the threading of p4 is carried out when the nut 6 is When the object to be tightened 4 is inserted and screwed into the combination male thread 5b, the dependent complete female thread part 8 has the root diameter d4 of the dependent complete female thread ≦ the root diameter d3 of the standard complete female thread part d3-2 Since the thread depth of the reference fully female threaded portion is set to r3, it passes through the male thread of the part corresponding to the reference fully female threaded portion 7 of the combination male thread 5b without engaging with it, and then smoothly threads the thread 5b.
This means that it can be fitted with the male thread of the corresponding part of the fully dependent fully female threaded part 8.

If a thread is formed by cutting the standard fully female threaded portion 7 and the dependent fully female threaded portion 8 using the above procedure, the root diameter of the dependent fully female threaded portion d4≦the root diameter of the standard fully female threaded portion d3-2 X
The thread depth r3 of the standard fully female threaded part and the pitch p4 of the dependent fully female threaded part < the pitch p3 of the standard fully female threaded part are formed, but the actual nut <
When designing the female thread 6, the dimensions of d3, d4, p3, and p4 should be determined so that the tightening force of the nut 6 is too large and permanent deformation occurs in the nut 6 beyond its elastic limit. , Difference in the root diameter of the fully female threaded part (Reference root diameter d of the fully female threaded part)
3 - The root diameter d4 of the dependent fully female threaded part is too small, and the pitch of the standard fully female threaded part 3 - The pitch p4 of the dependent fully female threaded part is too large, Care must be taken to ensure that the nut 6 is not unable to be tightened.

Incidentally, the pitch p3 of the reference fully female threaded portion and the pitch p4 of the dependent fully female threaded portion each include a reference pitch specified by the JIS thread standard, etc. This is to make it clear that thread cutting can be performed using a lathe, which is generally widely used. Either the pitch p3 or p4 is a reference pitch specified in the screw standard, and
In order to thread the other pitch with a dimension that is not specified in the thread standard, or to cut a thread with a pitch that is not specified in the thread standard with either of the above-mentioned pitches p3 or p4, use the lathe. It is necessary to install a thread cutting device as an accessory device.

5), how to determine the tightening margin S of the nut 6 when the female thread end of the dependent fully female thread part 8 is engaged with the tip of the mating male thread of the combination male thread 5b.
The tightening force acting on the contact surface between the seat surface of the nut 6 and the object to be tightened 4 is sufficient, and the tightening force is sufficient between the reference fully female threaded portion 7 and the dependent fully female threaded portion 8 for preventing loosening of the nut 6. Although it depends on whether the applied tensile force is sufficient, it is appropriate to determine the above S by experience to some extent. Also, if the tightening force of the nut 6 is insufficient, the bearing surface of the nut 6 Adjustments can also be made by inserting a washer between the body 4 and the body 4 to be tightened.

Next, the thread cutting tools are a die for threading the male thread for the bolt (male thread) 1, and a tap for threading the female thread 5a to be combined with the bolt (male thread) 1.
6 is a tap for cutting a female thread, and a die for cutting a male thread 5b combined with 6 above, and these taps and dies are each one thread cutting tool with different thread diameters and pitches. It differs from the generally widely used tap and die only in that it has two screws.

Effects of the Invention Regarding the bolt (male thread) 1, which represents the male thread of an elastic threaded part, in Fig. 3, the difference between the pitch p1 of the standard fully male threaded portion and the pitch p2 of the dependent fully male threaded portion indicates that the bolt is fully screwed. A compressive force acts in the direction of the arrow between the male threaded part 2 and the fully dependent male threaded part 3, and the frictional resistance between the male threaded part 2.3 and the mating female thread 5a increases, and this compressive force When tightening the bolt 1 where elastic deformation occurs between the male threaded portions 2 and 3, the bolt 1 is tightened so that the frictional resistance is maximized with the subsequent elastic contraction δ of the threaded portion. It can be effective. In addition, from the state in which the bolt 1 has tightened the body 4 in Figure 2 A, the bolt 4 may be deformed or lose its elasticity, and the bolt 1 may become deformed or lose its elasticity.
A gap is created between the contact surface of the bearing surface of the bolt 1 and the object to be tightened 4, and even if the bolt rotates and loosens as seen in ordinary bolts, the bolt 1 does not loosen and exhibits a loosening prevention effect. The same effect can be expected for the nut screw (6), which is representative of the female thread of an elastic screw component that can be used, for the same reason as in the case of the bolt (1) screw.

[Brief explanation of drawings]

Figure 1 shows a bolt representing a male thread, Figure 2 shows the state in which the bolt is inserted into a mating female threaded part through a tightened body, and Figure 3 shows the second part of A) in Figure 2. This indicates the state of fit between one male threaded part and the mating female threaded part.
In Figure 1.2.3, the parts necessary for explanation are marked d1,
d2, rl, r2. pi, p2. Indicated by s. Fig. 4 shows a nut representing a female thread, Fig. 5 shows a cross-sectional view of the nut inserted into a mating male threaded portion of a mating member via a member to be tightened, and Fig. 6 shows a nut representative of a female thread. This shows the state of fit between the two female threaded parts of i) and the mating male threaded part of the mating mating part. Indicated by r4, p3, p4, and S. In the diagram, 1 is the bolt (male thread), 2 is the standard complete male thread percentage
3 is a subordinate complete male thread, 4 is a tightened object, 5a is a combination female thread, 5b is a combination male thread 26 is a nut (female thread),
7 is a reference fully female threaded portion, and 8 is a dependent fully female threaded portion. Leather Figure 1 A] Mouth) Figure 5 Figure 6

Claims (1)

[Claims] 1> In order to prevent the male thread <1> from loosening, the above <1> has two male thread parts: a reference complete male thread part <2> and a dependent complete male thread part <3>. The above <2> has an outer diameter <d1>, pitch <p1>, and thread depth <r1>, and the above <3>
are outer diameter <d2>, pitch <p2>, thread depth <r2>
, and when forming the male thread, the thread of the standard complete male thread part <2> is continuously formed from the thread of the dependent complete male thread part <3>, and the mating combination is When combined with the female thread <5a>, the subordinate complete male thread part <3> can be easily screwed in. Outer diameter of part <d1> - 2 x Thread depth of standard fully male threaded part <r1>, <B> Pitch of dependent fully male threaded part <p2>
<The pitch of the standard complete male thread part <p1>, the pitch of the threaded part <p1>, <p2> each includes the reference pitch specified in the thread standard, and the dependent complete male thread part <3>
The male thread <1> is composed of the mating female thread <5>.
When tightening is performed in combination with a> and tightening body <4>, a compressive force acts from the pitch difference between the pitch of the standard fully male threaded part <p1> and the pitch of the dependent fully male threaded part <p2>, The elastic deformation caused by this compressive force is accompanied by the elastic contraction of the threaded part <6> due to the tightening of the male thread <1>, which occurs between the reference fully male threaded part <2> and the subordinate fully threaded part <3>. A locking elastic screw part characterized in that the threads of the male thread parts <2>, <3> and the mating female thread part <5a> are crimped together to become a detent. 2> In order to prevent the female thread <6> from loosening, said <6> has two female threaded parts, a standard fully female threaded part <7> and a dependent fully female threaded part <8>, and said <7>> forms a female thread with root diameter <d3>, pitch <p3>, and thread depth <r3>, and <8> above forms a female thread with root diameter <d4>, pitch <p4>, and thread depth <r4>. However, when forming the female thread, the structure is such that the thread of the dependent fully female thread part <8> is formed continuously from the thread of the standard fully female thread part <7>, and the mating male thread of the mating part <5b> is formed. When combined with 〉, it is possible to easily screw in the dependent fully female threaded portion, and <C> Root diameter of dependent fully female threaded portion <d4> ≦ Root diameter of standard fully female threaded portion <d3> -2 x Thread depth of reference fully female threaded part <r3>, <d> Pitch of dependent fully female threaded part <p4>
<Pitch of standard complete female thread part <p3>, pitch of the threaded part <p3>, <p4> each includes the reference pitch specified in the thread standard, depending on fully female thread part <8>
The female thread <6> is composed of the mating male thread <5>.
When tightening is performed in combination with b> and the object to be tightened <4>, a tensile force acts from the pitch difference between the pitch of the standard fully female threaded part <p3> and the pitch of the dependent fully female threaded part <p4>. , the elastic deformation due to this tensile force occurs between the reference fully female threaded portion <7> and the dependent fully female threaded portion <8>, accompanied by elastic elongation <γ> of the threaded portion due to tightening of the female thread <6>, A locking elastic screw component characterized in that the threads of the female thread parts <7>, <8> and the mating male thread <5b> are crimped to form a detent. 3> A die and a tap as a thread cutting tool for the male thread <1> and the combination female thread <5a> of the locking elastic screw component described in claim 1. 4> A tap and die as a thread cutting tool for the female thread <6> and the combination male thread <5b> of the locking elastic screw component described in claim 2.