KR102383042B1 - An axial alignment compensation thread fastener - Google Patents

Abstract

The present invention relates to an axis-compensated thread fastener. The axis-compensated thread fastener comprises: a normal screw portion having a plurality of normal threads formed on a screw column having a front end and a rear end; and a lead screw portion having at least one lead thread formed between the front end of the screw column and the plurality of normal threads and having an outer diameter smaller than or equal to the pitch diameter of the normal threads. The at least one lead thread has a lead thread profile including: a rear end straight portion having a rear end slope having an angle; a front end straight portion having a front end slope less than the rear end slope; and a central curved portion formed as a gently curved surface contacting the front end straight portion. The axis-compensated thread fastener allows the axis to be compensated for by being fastened to a mating female screw even when the axis is not correctly aligned with that of the mating female screw. Therefore, the axis can be properly compensated for even for screws with a narrow pitch.

Description

An axial alignment compensation thread fastener}

The present invention relates to an axis correction screw fastener that enables normal fastening while correcting the misaligned axis line even when the axis line of the part to be fastened is slightly misaligned.

BACKGROUND ART Screw fasteners such as bolts, screws, and nuts are essential fastening parts in assembly industries such as automobiles, electronics, and chemicals. In general, in order to fasten a part to a frame, a female screw is formed in the frame, and a fastening hole is formed in the component, and then fastened using a male screw fastener such as a bolt or screw.

At this time, when the male screw is not aligned in a straight line with the female screw of the frame and slightly shifted, there is a problem in that the male screw is not accurately fastened to the female screw. In order to solve this problem, the invention relates to a screw fastener that automatically corrects the axis line even when the holes of the part and the female screw are not accurately aligned. Threading Fastener" patent was presented.

US Patent No. 5,836,731 adopts a complex lead screw profile of a transitional curved profile in the shape of a lead screw thread, so there is a problem in that it is difficult to design and process the forming die (die). In addition, there is a problem that the function of the axis line correction is not sufficiently exhibited when the pitch of the thread becomes small.

Prior Document 1: U.S. Patent No. 5,836,731 (Jan. 17, 1998)

Accordingly, an object of the present invention is to provide an axis correction screw fastener that can be efficiently manufactured and can be properly axially corrected even in a screw with a narrow pitch.

In order to achieve the above technical object, an embodiment of the present invention provides an axis correction screw fastener, comprising: a top screw portion having a plurality of normal screws formed on a screw column having a front end and a rear end; and a lead screw portion formed between the front end portion of the screw column and the plurality of normal screw threads, and having at least one lead screw thread, wherein the lead screw thread has a rear end slope having a rear end slope of a predetermined angle, the rear end slope It provides an axis correction screw fastener, characterized in that it has a lead screw profile including a front inclined surface having a smaller tip inclination, and a central curved portion comprising a gently curved surface in contact with the rear inclined surface and the tip inclined surface.

In one embodiment of the present invention, the central curved portion may be formed to have a single radius of curvature.

In one embodiment of the present invention, the center of the radius of curvature of the central curved portion may be offset toward the front end rather than the point where the extension line of the rear end inclined surface and the extension line of the front end inclined surface meet each other.

In one embodiment of the present invention, a non-threaded cylindrical portion may be provided between at least one lead screw thread of the screw column and the tip portion.

In one embodiment of the present invention, the outer diameter of the non-threaded cylindrical portion may be smaller than the inner diameter of the thread of the other female screw to be fastened. This non-threaded cylindrical part passes through the thread of the other female screw without resistance when fastening.

In one embodiment of the present invention, a tip tapered portion may be formed between the non-thread cylindrical portion and the tip portion.

In one embodiment of the present invention, at least one of the lead screw growth portion on the tip side of the lead screw thread, the outer diameter of the lead screw thread within a 1/4 screw rotation angle from the non-thread cylindrical portion to gradually complete growth. there is.

In one embodiment of the present invention, the tip slope may be in the range of 40 degrees to 50 degrees. If the tip slope is smaller than the slope of the rear end by 40 to 50 degrees, it is easy to climb over the thread of the other female screw. Usually, the slope of the rear end is about 60 degrees.

In one embodiment of the present invention, the tip tapered portion may be formed in a round or straight shape.

In one embodiment of the present invention, the lead screw portion may be formed to have an outer diameter of the lead screw that is smaller than or equal to a pitch diameter of the normal screw.

The axis correction screw fastener according to the present invention having the above configuration has a simple lead screw thread shape, so it is easy to design and process the die, so it is possible to manufacture efficiently. It provides the effect that axis correction can be performed properly even with a narrow screw.

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a side view of an axis correction screw fastener according to a first embodiment of the present invention.
Figure 2 is a front view of the axis correction screw fastener according to the first embodiment of the present invention viewed from the tip side. (front view according to View “A”)
3 is a side view of an axis correction screw fastener according to a second embodiment of the present invention.
4 is a side view of an axis correction screw fastener according to a third embodiment of the present invention.
5 is a side view of an axis correction screw fastener according to a fourth embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in several different forms, and thus is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is "connected" with another part, this includes not only the case where it is "directly connected" but also the case where it is "indirectly connected" with another member interposed therebetween. . In addition, when a part "includes" a certain component, this means that other components may be further provided without excluding other components unless otherwise stated.

In the present invention, the upper and lower parts mean positioned above or below the target member, and do not necessarily mean positioned at the upper or lower part with respect to the direction of gravity.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The features and advantages of the present invention will become more apparent from the description of the preferred embodiments based on the accompanying drawings.

1 is a side view of an axis correction screw fastener according to a first embodiment of the present invention.

In assembly industries such as automobiles, electronics, chemicals, steel, and devices, all holes between parts to be fastened are not always aligned. There may be cases in which the axis lines are not aligned due to the assembly tolerance between the holes of the normally assembled parts.

In this case, if the axis correction screw fastener 100 of the present invention is used, the screw is fastened with a strong coupling force by correcting the axis line between the parts.

The axis correction screw fastener 100 according to the first embodiment of the present invention includes a screw column 60 and a screw head portion 50 .

The axis correction screw fastening tool 100 includes a front end 1 and a rear end 2, and the front end 1 is inserted into the hole of the opposite female screw to start the fastening. A screw head portion 50 is formed at the rear end 2 , and a rotation torque is received from the fastening tool through the screw head portion 50 .

When the screw head 50 of the present invention axis correction screw fastener 100 is inserted into a fastening tool such as a hexagon wrench, screwdriver, electric screwdriver, or air driver, and the rotation torque of the tool is transmitted, the present invention axis correction male screw (100) ) is fastened to the opposite female thread.

In the screw column 60 of the axis correction screw fastener 100 according to the first embodiment of the present invention, a plurality of normal screw threads 10, at least one lead screw thread 20, and a non-thread cylindrical part 30 from the rear end side. And a tip tapered portion 40 is formed.

The tip tapered part 40 is adjacent to the tip part 1 , and the top screw thread 10 on the rearmost side of the plurality of top threads 10 is adjacent to the screw head part 50 . The tip tapered portion 40 may have a round (R) or straight shape. In Example 1, a round is appropriately formed.

The screw shape of the normal normal screw thread 10 is manufactured according to the standard standard. The screw thread has an osseous diameter and a pedicle diameter in a cylindrical screw body. In addition, the screw thread has two sidewalls of about 60 degrees, and the top portion of the screw thread has a certain round (R) and forms an appropriate round in the valley as well.

On the other hand, at least one lead screw thread 20 formed on the screw column part 60 of the screw fastener 100 according to the first embodiment of the present invention is formed of three lead threads in the case of FIG. 1 , the present invention is not limited to the number of lead threads 20 . The plurality of lead screw threads 20 form a lead screw part, and the plurality of top screw threads 10 form a top screw part.

Since the pitches of the top screw thread 10 and the lead screw thread 20 are almost the same, the distance entering in the tip direction by one rotation of the screw is the same for the top screw thread 10 and the lead screw thread 20 .

The plurality of lead screws 20 formed in the axis correction screw fastener 100 according to the first embodiment of the present invention have a different screw profile from that of the normal screw thread 10 . In particular, the angles of the side walls at which the threads are formed are different. The pitch corresponding to the distance between the thread and the thread is almost the same.

The outer diameter D2 of the lead screw thread 20 formed in the axis correction screw fastener 100 according to the first embodiment of the present invention is smaller than the outer diameter D1 of the normal screw thread 10 . The outer diameter D2 of the lead screw thread 20 formed in the screw fastener 100 according to the first embodiment of the present invention is equal to or smaller than the pitch diameter Dp of the normal screw thread 10 . In the enlarged view of FIG. 1 , the outer diameter D2 of the lead screw thread 20 is the same as the pitch diameter Dp of the normal screw thread 10 as an example.

Therefore, even if the hole of the female screw to be fastened with the axis correction screwing tool 100 of the present invention is not completely aligned, the lead screw thread 20 forcibly rides over the female screw thread forming the inner diameter of the opposite female screw, so that the fastening is not possible. is done

The inclination of the rear end of the lead thread 20 of the screw fastener 100 capable of axis correction according to the first embodiment of the present invention (Fig. 1 enlarged view “a”) is the same as or similar to the normal 60 It is inside and outside the figure, and the tip slope (Fig. 1 enlarged view “b”) is made of 45 degrees smaller than the rear tip slope (60 degrees).

The thread profile 20p of the lead thread 20 of the screw fastener 100 capable of axial correction according to the first embodiment of the present invention is a rear end inclined surface 20b having a rear end inclination, and a front inclined surface 20a having a leading end inclination. ) and a central curved portion 20c having a gentle curved surface in contact with the rear slope and the tip slope.

As a preferred embodiment of the present invention, the central curved portion 20c is a curved portion forming the peak of the lead screw thread 20, and includes an arc, an ellipse, or a curved surface having a changing radius of curvature with a constant radius of curvature R.

In addition, a certain amount of offset is formed between the point where the extension line of the rear end straight part 20a and the extension line of the front end straight part 20b meet and the center point of the central curved part 20c by a constant radius of curvature R.

That is, the central point of the central curved portion 20c is located on the tip portion 1 side by an offset amount rather than the point where the extension line of the rear end straight portion 20a and the extension line of the front end straight portion 20b meet.

Since the central curved portion 20c of the present invention has a profile formed by a straight line and an arc or a straight line and a tangent to a gently curved portion, rather than a conventional profile forming an arbitrary transitional curve, the lead screw portion 20 design and Die processing is easy.

In addition, since the tip slope (b) is smaller than the slope (a) of the rear end, when the lead screw thread 20 is inserted into the female screw of the other party, it is easy to ride over the thread of the female screw of the other party.

In addition, when designing the lead thread profile, if the outer diameter (D2) of the lead thread (20) is smaller than the outer diameter (D1) of the normal thread (10) and smaller than the pitch diameter (Dp) of the normal thread (10), axis correction is performed effect is further maximized.

In this way, by setting the tip slope (b) of the lead screw thread (20) to be smaller than the rear end slope (a), the axis correction screw fastener 100 of the present invention is strongly applied to the hole of the female screw while applying strong pressure using a fastening tool. When the fastening is made, the lead screw thread 20 passes over the inner diameter of the screw thread of the counterpart female screw, and in the end, the normal screw thread 10 is strongly fastened with the counterpart female screw.

An inequality relationship of D1 > D2 > D3 is established between the outer diameter D1 of the top screw thread 10 , the outer diameter D2 of the lead screw thread 20 , and the outer diameter D3 of the non-threaded cylindrical portion 30 . On the other hand, if the pitch diameter of the normal thread 10 is Dp, the relationship of D1 > Dp ≥ D2 > D3 is also established.

In addition, it is preferable that the outer diameter (D3) of the non-thread cylindrical part 30 is smaller than the inner diameter (mountain diameter) of the other female screw. Accordingly, the non-thread cylindrical portion 30 is inserted into the opposite female screw without resistance and leads to fastening.

On the other hand, the lead screw 20 formed on the most distal side of the lead screw thread 20 starts from the non-threaded cylindrical portion 30 where the screw is not formed and gradually increases in an area of about 90 degrees or less (a quarter screw rotation area). As the outer diameter is increased, the lead screw thread 20 is fully grown. A lead screw growth start portion 21 , a lead screw growth transition portion 22 , and a lead screw growth completion portion 23 are sequentially provided on the most distal side of the lead screw thread 20 . From the start of such a lead screw thread 20, the completion of the lead screw thread growth is completed within about 90 degrees (1/4 turn).

The lead screw growth start portion 21, the lead screw growth transition portion 22 and the lead screw growth completion portion 23 on the tip side of the lead screw thread 20 are collectively referred to as the lead screw growth portion 24.

Figure 2 is a front view of the axis correction screw fastener 100 according to the first embodiment of the present invention viewed from the tip side. (front view according to View “A”)

The inside of the first concentric circle of the present invention axis correction screw fastener 100 corresponds to the tip portion 1 of the screw. The second concentric circle corresponds to the non-thread cylindrical portion 30 , and the space between the first concentric circle and the second concentric circle corresponds to the tip tapered portion 40 .

The third concentric circle corresponds to the lead thread 20 and the fourth concentric circle corresponds to the normal thread 10 .

On the other hand, the non-circular curved surface between the second concentric circle and the third concentric circle in the fourth quadrant of the concentric circle consists of a lead screw growth start part 21 , a lead screw growth transition part 22 and a lead screw growth completion part 23 . The lead screw growth part 24 is expressed.

On the other hand, similarly, the connecting portion of the third concentric circle and the fourth concentric circle indicated in the fourth quadrant of the concentric circle shows the connecting portion 26 in which the lead screw 20 grows into the normal screw 10 . At an angle slightly more than 90 degrees in the drawing, the lead screw 20 is completed to grow into a normal screw 10 . The present invention is not limited to the rotation angle of the screw when growing from the lead screw portion 20 to the top screw portion 10 . It is possible to grow into a normal screw within 90 degrees or around 60 degrees.

Growing each screw in the quadrants of a concentric circle is just one example. Growth can be completed within any angle of rotation in any quadrant or location.

3 is a side view of the axis correction screw fastener 100 according to the second embodiment of the present invention.

The second embodiment of the present invention is different from the first embodiment in that the tip inclination b of the lead screw part 20 is 40 degrees, which is slightly smaller than the tip inclination of 45 degrees in the first embodiment.

The remaining components are the same as in the first embodiment. In the second embodiment of the present invention, as a result, the outer diameter of the lead screw portion 20 is slightly smaller than the outer diameter of the lead screw portion 20 of the first embodiment, which is more easily inserted into the opposite female screw portion and passes over the inner diameter of the opposite female screw portion. it is easy

4 is a side view of the axis correction screw fastener 100 according to the third embodiment of the present invention.

The third embodiment of the present invention has the first embodiment (45 degrees) and the second embodiment (40 degrees) in that the tip slope (b) of the lead screw part 20 is 50 degrees when compared with the first and second embodiments. ) is different from

The remaining components are the same as in the first and second embodiments. In the third embodiment of the present invention, as a result, the outer diameter of the lead screw portion 20 becomes larger than that of the first or second embodiment.

5 is a side view of the axis correction screw fastener 100 according to the fourth embodiment of the present invention.

In the fifth embodiment of the present invention, the shape of the tip tapered portion 40 is different from the first to third embodiments. The tip tapered portion 40 of the first to third embodiments is a tapered portion subjected to an appropriate rounding process, and the fifth embodiment corresponds to a straight tapered portion.

When the first to third examples of the present invention were applied to commonly used fastening bolts having a pitch of 4 to 15 millimeters, good results were obtained when the tip inclination of the lead screw thread was 40 to 50 degrees. However, in most of the fastening bolts, when the tip slope was 55 degrees or more or the tip slope was 35 degrees or less, negative results were derived in the axis correction function and the external diameter management of the lead thread.

The present invention is capable of various embodiments other than the above embodiments. Therefore, the present invention is not limited to the above embodiment.

The description of the present invention described above is for illustration, and those of ordinary skill in the art to which the present invention pertains can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention.

100: axis correction screw fastener
1: tip
2: rear end
10: normal thread
20: lead thread
20a: rear slope
20b: tip slope
20c: central curvature
20p : lead thread profile
21: lead screw growth start part
22: lead screw growth transition part
23: lead screw growth completed part
24: lead screw growth part
26: connection part
30: non-thread cylindrical part
40: tip tapered part
50: screw head
60: screw column
D1 : Outer diameter of normal thread
D2 : Lead thread outer diameter
D3 : Outside diameter of non-threaded cylindrical part
Dp : Pitch diameter of normal thread
R: radius of curvature of central arc
Offset: The amount of offset of the radius center of the central arc part

Claims (10)

In the axis correction screw fastener,
a top screw portion having a plurality of top screw threads formed on a screw column having a front end and a rear end; and
It is formed between the distal end of the screw column and the plurality of normal screws, and includes a lead screw portion having at least one lead screw thread,
The lead screw thread has a rear end slope having a rear end slope of a certain angle, a front slope surface having a tip slope smaller than the rear end slope, and a lead screw thread including a central curved portion comprising a gentle curved surface in contact with the rear slope surface and the tip slope surface have a profile,
The front end slope is made in a range of 40 to 50 degrees, the rear end slope is made to be the same as the inclination slope of the adjacent top screw thread, and the lead screw part is smaller than or equal to the pitch diameter of the top screw thread. It is made to have a threaded outer diameter,
The central curved portion is made to have a single radius of curvature, and the center of the radius of curvature of the central curved portion is offset toward the tip rather than the point where the extension line of the rear slope and the extension line of the tip slope meet each other. screw fastener.
delete delete According to claim 1,
An axis correction screw fastener, characterized in that a non-threaded cylindrical portion is provided between at least one lead screw thread of the screw column and the distal end portion.
5. The method of claim 4,
The outer diameter of the non-threaded cylindrical part is an axis correction screw fastener, characterized in that it is smaller than the inner diameter of the thread of the other female screw to be fastened.
5. The method of claim 4,
An axis correction screw fastener, characterized in that a tip tapered part is formed between the non-screw cylindrical part and the tip part.
7. The method of claim 6,
An axis correction screw fastener, characterized in that at least one of the lead screw threads has a lead screw growth part at which the outer diameter of the lead screw thread gradually grows within a 1/4 screw rotation angle from the non-thread cylindrical part.
delete 7. The method of claim 6,
The shaft line correction screw fastener, characterized in that the tip tapered portion is formed in a round or straight shape.
delete

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