WO2015160173A1 - Screw coupling structure for preventing loosening and method for producing screw coupling structure for preventing loosening - Google Patents

Abstract

The present invention relates to a screw coupling structure for preventing loosening, and more specifically, to a screw coupling structure for preventing loosening between a screw and a coupling part, the screw coupling structure comprising: a screw part which has a predetermined length and is extended; and a coupling part which has a screw hole for inserting and coupling the screw part, wherein the screw part is made of a shape memory alloy, and the shape memory alloy has the properties of changing shape when external force is applied thereto at a temperature lower than a predetermined critical temperature, and being restored to the original shape when a higher temperature than the critical temperature is applied.

Description

Anti-loosening screw fastening structure and manufacturing method of anti-loosening screw fastening structure

The present invention relates to an anti-loosening screw fastening structure, and more particularly, to deform when an external force is applied at a low temperature lower than a predetermined threshold temperature, and to restore the deformation according to the application of a high temperature higher than the threshold temperature. It is directed to an anti-loosening screw fastening structure, which can be prevented from loosening.

The screw, one of the seven inventions of mankind, has the most serious problem of loosening with time due to external vibration and stress. In particular, since the screw used in the human body is difficult to retighten when loosened, a definite measure is required.

For example, such a screw is used, and as an example, the dental implant is configured as shown in FIG. 1. First, the media is placed on the gum bone, and the abutment and connecting screw are connected between them to raise the crown. This connection screw is sometimes loosened, causing various problems, such as the crown shaking. In the case of implants, it is known that the internal screws are loosened due to the tremendous loads and vibrations that are repeatedly applied when chewing food, and the electric toothbrush sometimes accelerates the screw loosening phenomenon.

As shown in Fig. 2, the general screw has a gap in the screw portion, so that screwing is possible. When an external stress occurs, a space is created at the junction of the thread, and the seat surface under the head of the screw is opened and released. In other words, the male thread should be elastically stretched in the longitudinal direction, but if the elastic tension is lost, the screw will be loosened. Normal metal has a steep force / displacement slope and elastic deformation is only 0.3-0.5% by tensile strength. Therefore, even if a slight movement is caused by the external force, the elastic force is greatly lowered, and as a result, the movement becomes easier and the screw is easily released. The most commonly used washers to prevent loosening of screws are also intended to increase this elasticity. But washers of ordinary metals also extend the unwinding time slightly, which does not solve the problem inherently.

The present invention has been made to solve the above-mentioned problems, and deforms when an external force is applied in a low temperature state lower than a predetermined threshold temperature, and has the property that the deformation is restored in accordance with the application of a high temperature higher than the threshold temperature, It is an object of the present invention to provide an anti-loosening screw fastening structure which is prevented from loosening.

In order to achieve the above object, the anti-loosening screw fastening structure according to the present invention, in the anti-loosening screw fastening structure for preventing loosening between the screw and the fastening portion, the screw portion having a predetermined length; And a fastening part having a screw hole to insert and fasten the screw part, wherein the screw part is formed of a shape memory alloy, wherein the shape memory alloy deforms when an external force is applied at a low temperature lower than a predetermined threshold temperature. The deformation is restored in accordance with the application of a high temperature higher than the critical temperature.

Preferably, the screw portion has a male screw formed on the outer surface, the fastening portion has a female screw formed on the inner surface of the screw hole, the screw portion is at least partially compressed or tensioned in the longitudinal direction at a lower temperature than the critical temperature processing And is heated to a temperature higher than the critical temperature in the state of being inserted into the fastening part, and is restored in the longitudinal direction so that a stress is applied between the male screw and the female screw.

Preferably, the screw portion is pressurized in the width direction at a low temperature state lower than the threshold temperature and compressed, and heated to a temperature higher than the threshold temperature in the state inserted into the fastening portion is stretched in the width direction, the screw portion Is configured to apply a stress in the width direction with respect to the screw hole.

Anti-loosening screw fastening structure according to an embodiment, the screw portion having a predetermined length and extending in the head portion; A fastening part having a screw hole to insert and fasten the screw part; And a washer disposed between the fastening portion and the head in a state where the screw portion is inserted into the fastening portion, wherein the screw portion has a male screw formed on an outer surface thereof, and the fastening portion has a female screw formed on an inner surface of the screw hole. The washer is composed of a shape memory alloy, and the shape memory alloy is deformed when an external force is applied at a low temperature lower than a predetermined threshold temperature, and the deformation is restored upon application of a high temperature higher than the threshold temperature. .

Preferably, the washer is compressed in the longitudinal direction at a lower temperature than the critical temperature, and is disposed between the fastening portion and the head while the screw portion is inserted into the fastening portion, and the fastening portion and the It is configured to be heated to a temperature higher than the threshold temperature in the state disposed between the heads and to recover in the longitudinal direction to apply stress between the male and female threads.

Preferably, the shape memory alloy contains a Ni—Ti alloy.

Preferably, the critical temperature has a range of 20 to 30 ° C.

The method of manufacturing the anti-loosening screw fastening structure according to the present invention includes a screw portion composed of a shape memory alloy which has a predetermined length and extends and is formed at a lower temperature lower than a predetermined threshold temperature to be restored as the strain is heated to a temperature higher than the threshold temperature. Providing a; Providing a fastening part having a screw hole into which the screw part is inserted; Machining the thread below a critical temperature; Inserting the screw portion into the screw hole to perform the fastening between the fastening portion and the screw portion; And recovering the screw portion by heating the screw portion to a temperature higher than the threshold temperature.

Advantageously, machining said threaded portion below said critical temperature comprises: tensioning or compressing said threaded portion at least partially in the longitudinal direction; And forming a male screw portion on the screw portion.

Preferably, the step of processing the screw portion below the critical temperature, comprising the step of compressing the screw portion in the width direction.

According to an embodiment of the present invention, a method of manufacturing a fastening screw fastening structure includes: providing a screw unit having a predetermined length and having a head at one end thereof; Providing a fastening part having a screw hole into which the screw part is inserted; Providing a washer made of a shape memory alloy that recovers as the strain formed at a lower temperature below a predetermined threshold temperature is heated to a temperature above the threshold temperature; And inserting the screw portion into the screw hole to perform the fastening between the fastening portion and the screw portion, wherein the washer is positioned between the head and the fastening portion.

Preferably, between the step of providing the washer and the step of placing the washer between the head and the fastening portion, the step of compressing in the longitudinal direction by compression processing below the critical temperature; wherein the washer is After the step of positioning between the head and the fastening portion, heating the washer to a temperature higher than the threshold temperature to restore the washer in the longitudinal direction.

Advantageously, providing the washer comprises: providing a coil comprised of a shape memory alloy; And cutting one side in the radial direction of the coil along a length direction to provide a plurality of ring-shaped washers.

According to the loosening screw fastening structure according to the present invention, since the screw portion or the washer is made of a shape memory alloy and processed at a low temperature, the high temperature is applied and restored in a state where the screw portion or the washer is fastened. It is made firm and unnecessary release can be prevented.

1 is a view showing an example of a dental implant according to the prior art.

2 is a view showing an example of screw loosening.

3 is a view showing a configuration process of the screw fastening structure for preventing loosening according to an embodiment of the present invention.

Figure 4 is a view showing the configuration of the screw fastening structure for preventing loosening according to an embodiment of the present invention.

5 is a view showing a configuration process of the anti-loosening screw fastening structure according to an embodiment of the present invention.

6 is a view showing a configuration process of the fastening preventing screw fastening structure according to an embodiment of the present invention.

7 is a view showing a configuration process of the fastening preventing screw fastening structure according to an embodiment of the present invention.

8 is a view showing a configuration process of the fastening preventing screw fastening structure according to an embodiment of the present invention.

9 is a view showing the deformation behavior of the shape memory alloy used in the anti-loosening screw fastening structure according to an embodiment of the present invention.

10 is a view showing the manufacture of a washer used in the screw fastening structure for preventing loosening according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. This embodiment is not intended to be limiting.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, "comprises" and / or "comprising" refers to the presence of one or more other components, steps, actions and / or members. Or does not exclude additions.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used in a sense that can be commonly understood by those skilled in the art. In addition, the terms defined in the commonly used dictionaries are not ideally or excessively interpreted unless they are specifically defined clearly.

1 is a view showing an example of a dental implant according to the prior art, Figure 2 is a view showing an example of screw loosening, Figure 3 is an anti-loosening screw fastening structure according to an embodiment of the present invention 4 is a view illustrating a configuration process, and FIG. 4 is a view illustrating a configuration process of an anti-loosening screw fastening structure according to an embodiment of the present invention, and FIG. 5 is a diagram of an anti-loosening screw fastening structure according to an embodiment of the present invention. 6 is a view showing a configuration process, Figure 6 is a view showing a configuration process of the anti-loosening screw fastening structure according to an embodiment of the present invention, Figure 7 is a loosening prevention screw fastening structure according to an embodiment of the present invention 8 is a view showing a configuration process, Figure 8 is a view showing a configuration process of the anti-loosening screw fastening structure according to an embodiment of the present invention, Figure 9 is a loosening prevention screw fastening structure according to an embodiment of the present invention Fig. 10 is a view showing the deformation behavior of the shape memory alloy used in Figs.

(A) to (e) shown in Figures 3 to 8 each show a configuration process of the anti-loosening screw fastening structure according to an embodiment of the present invention in order.

In order to achieve the above object, the anti-loosening screw fastening structure according to an embodiment of the present invention, in the anti-loosening screw fastening structure for preventing the loosening between the screw portion 100 and the fastening portion 200, a predetermined length Screw portion 100 extending with; And a fastening part 200 having a screw hole 210 so that the threaded part 100 is inserted and fastened, wherein the screw part 100 is formed of a shape memory alloy, and the shape memory alloy has a predetermined critical temperature. When the external force is applied at a lower temperature, the strain is deformed, and the deformation is restored in response to the application of a higher temperature than the critical temperature.

As shown in Figure 3, the anti-loosening screw fastening structure according to the present invention, the screw portion 100 having a predetermined length and extending; And a fastening part 200 having a screw hole 210 so that the screw part 100 is inserted into and fastened.

The screw part 100 includes a screw having a predetermined beam shape in which the male screw 120 is not formed, as shown in FIGS. 3 and 4, in addition to the general screw in which the male screw 120 is formed. No. The thread portion 100 has a predetermined length and extends.

The fastening part 200 is a predetermined nut or various fastening members. Any fastening part 200 may be applied to any member having a screw hole 210 in which the screw part 100 is inserted and fastened. In the screw hole 210 formed in the fastening part 200, in addition to the conventional screw hole 210 in which the female screw 220 is formed in the same manner as the screw part 100, a predetermined screw hole 100 may be inserted. It may be an insertion hole of, and the form is not limited.

The screw portion 100 is formed of a shape memory alloy, the shape memory alloy is deformed when an external force is applied in a low temperature state lower than a predetermined threshold temperature, the deformation is restored in accordance with the application of a high temperature higher than the threshold temperature Has the nature. That is, the threaded part 100 is deformed by applying an external force in a low temperature state lower than a predetermined threshold temperature, and then applies a temperature higher than the threshold temperature in a state where the threaded part 100 is inserted into the fastening part 200. Can be restored to its original state.

In this case, the deformation in the low temperature state, for example, may be compression in the width direction of the screw portion (100). That is, the screw part 100 is compressed in the width direction in a low temperature state lower than the threshold temperature, and in accordance with the application of a high temperature higher than the threshold temperature in the state inserted into the screw hole 210 of the fastening part 200. The screw portion 100 is restored to its original state in the width direction so that the screw portion 100 stresses the screw hole 210 in the width direction, and the screw portion 100 and the fastening portion 200 are in close contact with each other, and the screw portion 100 ) And a fastening between the fastening portion 200 can be achieved.

In this case, in the widthwise compression processing of the screw part 100, in addition to the method of directly compressing the screw part 100 in the width direction, a method of compressing the width by tensioning the screw part 100 in the longitudinal direction may be used. It is not limited to this. That is, the arrows shown in FIGS. 3 and 4 (b) indicate the compression and tension of the threaded portion 100, and the arrows in (e) indicate the tension upon recovery.

In Figs. 3 and 4, (a) to (e) show such a construction sequence, where (b) and (c) respectively indicate processing below the critical temperature, and (d) indicates below the critical temperature. (E) indicates that the threaded portion 100 is restored to its original state in a temperature atmosphere at or above a critical temperature, so that a bond between the threaded portion 100 and the fastening portion 200 is achieved.

For example, when the diameter of the screw hole 210 is x, and the diameter of the threaded portion 100 is x + a, the diameter of the screw hole 210 is slightly larger than the x, the screw portion 100 is Pressurized, or stretched, at a temperature below the critical temperature so as to have a width less than or equal to x. Thereafter, when the thread part 100 is inserted into the screw hole 210 and a temperature higher than a critical temperature is applied, the thread part 100 tries to return to the original diameter x + a, and the screw hole 210 Since the diameter of x, the screw portion 100 is applied a strong clamping force against the screw hole (210). That is, it has the effect of forcibly inserting a screw having a diameter of x + a into the screw hole 210 having a diameter of x, and thus has excellent bonding force.

On the other hand, this configuration can also be applied to the bonding of the predetermined disk 110 constituting a predetermined head on the upper portion of the screw portion 100 as shown in FIG. That is, after deforming the screw portion 100 at a low temperature, a predetermined disk 110 is inserted into the upper portion of the screw portion 100 before the high temperature is applied, and then a high temperature is applied between the disc 110 and the screw portion 100. Binding can be performed.

5 and 6 illustrate a fastening screw fastening structure and a manufacturing method thereof according to an embodiment of the present invention.

According to one example, the screw portion 100 has a male screw 120 formed on the outer surface, the fastening portion 200 has a female screw 220 formed on the inner surface of the screw hole 210, the screw portion 100 At least one portion is compressed or stretched in the longitudinal direction in a low temperature state lower than the threshold temperature, and is processed to be heated to a temperature higher than the threshold temperature in the inserted state in the fastening part 200 to recover in the longitudinal direction. The stress is applied between the male screw 120 and the female screw 220.

That is, as shown in FIGS. 5 and 6, the screw part 100 has a male screw 120, and the screw hole 210 has a female screw 220. At this time, the screw portion 100 is at least partially compressed or stretched in the longitudinal direction at a temperature lower than the threshold temperature, and is heated to a temperature higher than the threshold temperature in the inserted state in the fastening portion 200 to recover in the longitudinal direction. do. At this time, a longitudinal relative displacement between the male screw 120 formed in the screw part 100 and the female screw 220 formed in the screw hole 210 is achieved, and the close contact between the male screw 120 and the female screw 220 adjacent to the male screw 120 is achieved. Will be done. Accordingly, excellent bonding between the threaded portion 100 and the threaded hole 210 is achieved.

On the other hand, at this time, since it is sufficient to achieve close contact between the male screw 120 and the female screw 220 in the longitudinal relative displacement between the male screw 120 and the female screw 220, the screw portion 100 is compressed or tensioned in the longitudinal direction. 5 may be an entire length direction of the threaded portion 100 as shown in FIG. 5, or may be a portion as shown in FIG. 6, but is not limited thereto. Here, the dotted line portions of the threaded portion 100 of FIGS. 5 and 6 represent a state of being compressed or stretched in the longitudinal direction at a temperature lower than the critical temperature. That is, in FIG. 5 (b) to (d), the thread part 100 is compressed or stretched as a whole, and in FIG. 6 (d) to (e), the difference in which the upper part of the thread part 100 is partially compressed or tensioned is different. have.

Subsequently, when returning to a temperature higher than the critical temperature as shown in FIGS. 5 and 6 (f), the thread portion 100 is compressed and stretched in the longitudinal direction when it is restored in the longitudinal direction. 5 and 6 (f), the length is returned at a temperature higher than the critical temperature, the threaded portion 100 is shown as a solid line as a whole.

For example, when the thread part 100 is compressed or tensioned in the longitudinal direction as a whole, the interval between the male thread 120 formed in the thread part 100 is displaced so that a close contact with the female thread 220 part 100 can be achieved. When the screw part 100 is partially compressed or tensioned in the longitudinal direction, the male screw 120 formed on the screw part 100 may be displaced to achieve firm contact with the female screw 220 part 100.

The arrows shown in FIGS. 5B and 6D show the tension of the threaded portion 100, and the arrows shown in FIGS. 5E and 6F show the tension upon recovery.

In Figs. 5 and 6, (a) to (e) and (f) show such a structural sequence, where (b) and (c) of Fig. 5 respectively indicate processing under a critical temperature, and (d Denotes the insertion below the threshold temperature, and (e) indicates that the thread portion 100 is restored to its original state in a temperature atmosphere above the threshold temperature, so that the bond between the thread portion 100 and the fastening portion 200 is achieved. Here, in (b), the overall tension of the threaded portion 100 was made at or below the critical temperature. Therefore, in (e), the threaded portion 100 is hardened by restoring in the longitudinal direction.

In addition, (d) of FIG. 6 shows the process below a threshold temperature, (e) shows the insertion below a threshold temperature, (f) shows the thread part 100 returning to an original state in the temperature atmosphere above a threshold temperature. This shows that the binding between the threaded portion 100 and the fastening portion 200 has been achieved. Here, in (d), the partial tension of the upper portion of the threaded portion 100 is made below the critical temperature. Therefore, in (e), the threaded portion 100 is repaired in the longitudinal direction, thereby solidifying the binding.

According to this, the method of manufacturing the anti-loosening screw fastening structure according to the present invention is a shape memory, which has a predetermined length and is elongated and restored as a deformation formed at a lower temperature below a predetermined threshold temperature is heated to a temperature higher than the threshold temperature. Providing a screw part 100 formed of an alloy; Providing a fastening part 200 having a screw hole 210 into which the screw part 100 is inserted; Machining the threaded portion (100) below a critical temperature; Inserting the screw portion (100) into the screw hole (210) to perform the fastening between the fastening portion (200) and the screw portion (100); And recovering the threaded part 100 by heating the threaded part 100 to a temperature higher than the threshold temperature.

At this time, the step of processing the screw portion 100 below the critical temperature, the step of tensioning or compressing at least a portion of the screw portion 100 in the longitudinal direction; And forming a male screw portion 120 and a portion 100 in the screw portion 100. Alternatively, the step of processing the threaded portion 100 below a critical temperature may include compressing the threaded portion 100 in the width direction. That is, as described in the screw loosening prevention structure, the step of machining the screw portion 100 below the critical temperature, includes the step of deforming or compressing the screw portion 100, the deformation is After the screw portion 100 is fastened to the fastening portion 200 and restored by applying a high temperature of a critical temperature or more, thereby forming a solid binding force between the screw portion 100 and the fastening portion 200.

7 and 8 illustrate an anti-loosening screw fastening structure according to an embodiment of the present invention.

Anti-loosening screw fastening structure according to an embodiment of the present invention, the screw portion 100 having a predetermined length extending and having a head 130 on the top; A fastening part 200 having a screw hole 210 so that the screw part 100 is inserted and fastened; And a washer 300 disposed between the fastening part 200 and the head 130 in a state where the screw part 100 is inserted into the fastening part 200, wherein the screw part 100 is disposed on an outer surface thereof. Has a male screw 120 formed, the fastening portion 200 has a female screw 220 formed on the inner surface of the screw hole 210, the washer 300 is made of a shape memory alloy, the shape memory alloy is When the external force is applied in a low temperature state lower than a predetermined threshold temperature, the strain is deformed, and the deformation is restored according to the application of the high temperature higher than the threshold temperature.

In the threaded part 100 according to the present embodiment, a male screw 120 and a head 130 at a longitudinal end thereof are formed, and a female screw 220 is formed in the screw hole 210. In this embodiment, the screw portion 100 is made of a common metal, but a washer 300 made of a shape memory alloy is provided separately.

The washer 300 may have a configuration such as a kind of nut. That is, the screw part 100 may have a predetermined washer hole 310 through which the thread part 100 may pass. Accordingly, the screw part 100 is inserted into the screw hole 210 of the fastening part 200 through the washer 300, and when the screw part 100 is fully inserted, the washer 300 is the screw part. It is sandwiched between the head 130 and the fastening part 200 of the (100). On the other hand, this is a preferred embodiment, not limited to this, the washer 300 is any configuration as long as it has a configuration that can be sandwiched between the head 130 and the fastening portion 200 of the screw portion (100).

As the washer 300 is formed of a shape memory alloy, the washer 300 applies a stress due to elastic deformation to the head 130 and the fastening part 200 in the fastening process, thereby causing the screw part 100 and the fastening part ( Fastening between 200 can be made reliably.

At this time, as the head 130 of the screw unit 100 is firmly pressed against the upper part of the washer 300 and fastened strongly, the washer 300 may not need to be processed separately below a critical temperature. That is, as shown in FIG. 7C, the processing of the washer 300 is not performed at a critical temperature or less, and only by pressing the head 130 of the screw portion 100 strongly against the upper portion of the washer 300. The washer 300 may be deformed and returned so that a strong fastening may be performed between the screw part 100 and the fastening part 200.

The arrow shown in (c) of Figure 7 represents the pressure by the head 130 of the threaded portion 100 and the arrow of (d) represents the tension according to the recovery.

In Fig. 7, (a) to (d) show this configuration procedure. Here, (a) to (d) may all be made above the threshold temperature.

On the other hand, as shown in FIG. 8, according to one embodiment, preferably, the washer 300 is compressed in the longitudinal direction in a low temperature state lower than the critical temperature, and the screw portion 100 has the fastening portion 200. Disposed between the fastening part 200 and the head 130 in a state of being inserted into the fastening part 200 and heated to a temperature higher than the threshold temperature in a state disposed between the fastening part 200 and the head 130. Recovered in the longitudinal direction is configured to apply a stress between the male screw 120 and the female screw 220.

At this time, the washer 300 is sandwiched between the head 130 and the fastening part 200 in a compressed state at a low temperature below a threshold temperature, and then is restored to its original state by applying a high temperature above the threshold temperature. At this time, since the washer 300 is firmly sandwiched between the head 130 and the fastening part 200, the washer 300 is pushed between the head 130 and the fastening part 200 as the washer 300 recovers. . Accordingly, as shown in the above embodiment, the screw part 100 is minutely displaced, and the male screw 220 part 100 formed in the screw hole 210 has the male screw 120 part 100 formed in the screw part 100. Relative displacement with respect to) achieves close contact and bonding between the male screw 120 portion 100 and the female screw 220 portion 100.

According to the present embodiment, processing of the entirety of the male screw 120 part 100 is not required, and only a temperature application and processing for the washer 300 are required, thereby reducing processing cost and easily processing. have.

The arrow shown in FIG. 8 (b) represents the compression of the washer 300 and the arrow of (e) shows the tension upon recovery.

In Fig. 8, (a) to (e) indicate such a construction sequence, where (b) and (c) respectively indicate processing below the critical temperature, and (d) indicates insertion below the critical temperature. , (e) indicates that the threaded portion 100 is restored to its original state in a temperature atmosphere of a critical temperature or more, and the washer 300 pushes the threaded portion 100 and the fastening portion 200 between the threaded portion 100 and the fastening portion 200. Indicates that the bond is achieved.

According to the above process, the method of manufacturing a loosening screw fastening structure according to an embodiment of the present invention comprises the steps of: providing a screw portion 100 having a predetermined length and extending at one end; Providing a fastening part 200 having a screw hole 210 into which the screw part 100 is inserted; Providing a washer (300) made of a shape memory alloy which is restored as the strain formed at a lower temperature below a predetermined threshold temperature is heated to a temperature above the threshold temperature; Insert the screw part 100 into the screw hole 210 to perform the fastening between the fastening part 200 and the screw part 100, but the washer 300 is the head 130 and the fastening part 200 And positioned between).

Preferably, between preparing the washer 300 and positioning the washer 300 between the head 130 and the fastening part 200, the washer 300 is below the threshold temperature. Compressing and compressing in the longitudinal direction; It includes, and after the washer 300 is positioned between the head 130 and the fastening portion 200, by heating the washer 300 to a temperature higher than the threshold temperature to the washer 300 ) In the longitudinal direction.

The present invention is a method for forming the binding between the fastening portion 200 and the threaded portion 100 by using the washer 300 described above, to position the washer 300 between the head 130 of the threaded portion 100 There is a method, in addition, there is a method for processing the washer 300 below the critical temperature and is located between the fastening portion 200 and the head 130 of the threaded portion 100 and then applying a high temperature above the critical temperature to recover. Can be. By forming the fastening in this manner, the joint between the screw portion 100 and the fastening portion 200 is achieved.

In the method of manufacturing the loosening screw fastening structure according to the present invention, the critical temperature is 20? To 30? Therefore, the anti-loosening screw fastening structure manufactured according to the anti-loosening screw fastening structure manufacturing method according to the present invention can be used in the above-described implant and the like.

9 is a view showing the deformation behavior of the shape memory alloy used in the anti-loosening screw fastening structure according to an embodiment of the present invention.

Preferably, in the above-described embodiment, the shape memory alloy contains a Ni-Ti alloy. Such Ni-Ti alloys have a deformation tendency as shown in the drawing. That is, as shown in (a) of FIG. 9, deformation occurs easily at the temperature below the critical temperature according to the application of an external force, and when the deformation is solved, it has a permanent deformation state in which some deformation states remain. However, if a temperature above the critical temperature is added to the original state, this is called a shape memory effect, and a deformation of about 8% based on tensile or compression can be recovered.

On the other hand, the Ni-Ti alloy exhibits a shape memory effect and superelasticity in a temperature range of about 200 ° C. from a low temperature of liquid nitrogen, and an atomic ratio of Ni forms 44 to 55 atomic%, and the balance consists of Ti. It is an alloy. Meanwhile, in the composition, some components of about 10% or less of Ni and Ti may be substituted with Fe, Co, Cr, Al, Pd, or the like.

If the strain is at a temperature above the critical temperature, as shown in FIG. 9 (b), the stress initially increases linearly and rapidly according to the amount of deformation, as in general metals, and the stress remains constant even when the amount of deformation increases. Subsequently, when the strain is released slowly, the stress initially decreases and then becomes constant again. Finally, the stress decreases linearly like ordinary metal. It is called a super-elastic effect because it can have a large elasticity of about 8%.

Deformation below the critical temperature and then restraining it from returning to its original shape when heated above the critical temperature exerts a force to return. The present invention utilizes the properties of such Ni-Ti alloys.

Preferably, the critical temperature has a range of 20 ° C to 30 ° C. That is, after the threaded part 100 or the washer 300 according to the present invention is processed at 20 ° C. to 30 ° C. or lower, the thread part 100 or the washer 300 is restored to its original state at a temperature above the temperature. Accordingly, the screw loosening prevention structure according to the present invention can be applied to various body assistive devices implanted in the body. For example, in the case of an implant, the loosening of the screw becomes a problem. When the screw loosening prevention structure according to the present invention is applied to the screw structure applied to the implant, the body temperature when implanted into the body after processing at a temperature lower than the body temperature By returning to the original state by the exerting a strong bonding force, the screw loosening of the implant can be prevented. On the other hand, unnecessary recovery due to body temperature during the implantation process can be solved by cooling from time to time using cold water or the like.

On the other hand, the washer 300 may be manufactured by the following method.

First, a coil made of a Ni-Ti shape memory alloy is prepared as shown in FIG. Preferably, the coil has a narrow winding gap. Preferably, as shown in (a) of Figure 10 may have a configuration that is wound in contact with each other in the lateral direction. In addition, according to the inner diameter of the washer 300 to be manufactured may have a suitable inner diameter and wound form. In addition, the cross section of the line constituting the coil may have a rectangular shape as a whole. As a whole, the term “quadrate” includes all the deformed shapes, such as rounded corners or some curved surfaces, in addition to the exact quadrangle, and a quadrangular shape having four sides as a whole.

Next, the coil is cut. The coil is cut in the radial direction, but not all the ends of the diameter are cut, but only one side is cut to separate the cut coil into a ring shape. That is, by cutting the coil according to the cutting line shown by C-C in FIG. 10A, a ring washer 300 as in FIG. 10B is separated from the coil. On the other hand, since the cutting is made in the longitudinal direction of the coil, it is possible to configure the washer 300 by simple cutting without the need for complicated work.

In other words, by simply cutting the member formed in the coil shape in the longitudinal direction along the cutting plane in the radial direction, it is possible to simply manufacture the washer 300 used in the anti-loosening screw fastening structure according to the present invention.

That is, the preparing of the washer 300 may include preparing a coil made of a shape memory alloy; And cutting a plurality of ring-shaped washers 300 by cutting one side in a radial direction of the coil along a length direction. When the washer 300 is manufactured in this manner, since one washer is produced on one wheel of the coil, there is no waste of materials and mechanical processing may be reduced.

Although the preferred embodiments have been illustrated and described above, the invention is not limited to the specific embodiments described above, and does not depart from the gist of the invention as claimed in the claims. Various modifications may be made by the person having the above, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

Claims (14)

In the anti-loosening screw fastening structure for preventing loosening between the screw and the fastening portion, A thread portion extending with a predetermined length; And a fastening part having a screw hole to fasten the screw part to be inserted therein. The screw portion is made of a shape memory alloy, The shape memory alloy, The anti-loosening screw fastening structure having the property of deforming when an external force is applied in a low temperature state lower than a predetermined threshold temperature and recovering the deformation according to application of a high temperature higher than the critical temperature. The method of claim 1, The screw portion has a male screw formed on the outer surface, The fastening portion has a female screw formed on the inner surface of the screw hole, The screw portion, At least partially compressed or stretched in the longitudinal direction at a low temperature below the critical temperature, and then processed An anti-loosening screw fastening structure, wherein the screw is heated to a temperature higher than the critical temperature in the state of being inserted into the fastening part, and is restored in the longitudinal direction so that a stress is applied between the male and female screws. The method of claim 1, The screw portion, It is pressurized in the width direction in a low temperature state lower than the critical temperature and compressed. In the state inserted into the fastening portion is heated to a temperature higher than the critical temperature is tensioned in the width direction, An anti-loosening screw fastening structure, wherein the screw portion applies stress to the screw hole in the width direction. In the anti-loosening screw fastening structure for preventing loosening between the screw and the fastening portion, A thread portion having a predetermined length and extending and having a head thereon; A fastening part having a screw hole to insert and fasten the screw part; And a washer disposed between the fastening part and the head in a state where the screw part is inserted into the fastening part. The screw portion has a male screw formed on the outer surface, The fastening portion has a female screw formed on the inner surface of the screw hole, The washer consists of a shape memory alloy, The shape memory alloy, The anti-loosening screw fastening structure having the property of deforming when an external force is applied in a low temperature state lower than a predetermined threshold temperature and recovering the deformation according to application of a high temperature higher than the critical temperature. The method of claim 4, wherein The washer is, Compressed in the longitudinal direction at a lower temperature than the critical temperature, disposed between the fastening portion and the head in the state where the screw portion is inserted into the fastening portion, The anti-loosening screw fastening structure which is heated to a temperature higher than the critical temperature in the state disposed between the fastening portion and the head to recover in the longitudinal direction to apply a stress between the male screw and the female screw. The method according to claim 1 or 4, The shape memory alloy, Loosen screw fastening structure containing Ni-Ti alloy. The method according to claim 1 or 4, The critical temperature is 20 to 30 ° C anti-loosening screw structure. An implant structure having an anti-loosening screw fastening structure according to any one of claims 1 and 4. As a method of manufacturing an anti-loosening screw fastening structure, Providing a threaded portion of a shape memory alloy extending with a predetermined length and formed at a lower temperature below a predetermined threshold temperature and restored as the strain is heated to a temperature above the threshold temperature; Providing a fastening part having a screw hole into which the screw part is inserted; Machining the thread below a critical temperature; Inserting the screw portion into the screw hole to perform the fastening between the fastening portion and the screw portion; And recovering the threaded portion by heating the threaded portion to a temperature higher than the threshold temperature. The method of claim 9, The step of machining the screw portion below the critical temperature, Tensioning or compressing the thread at least partially in the longitudinal direction; And Forming a male screw portion to the screw portion; Anti-loosening screw fastening structure manufacturing method comprising a. The method of claim 9, The step of machining the screw portion below the critical temperature, Compressing the screw portion in the width direction; Anti-loosening screw fastening structure manufacturing method comprising a. As a method of manufacturing an anti-loosening screw fastening structure, Providing a threaded portion having a length and extending and having a head at one end; Providing a fastening part having a screw hole into which the screw part is inserted; Providing a washer made of a shape memory alloy which is restored as the strain formed at a lower temperature below a predetermined threshold temperature is heated to a temperature above the threshold temperature; Inserting the screw portion into the screw hole to perform the fastening between the fastening portion and the screw portion, wherein the washer is positioned between the head and the fastening portion; Anti-loosening screw fastening structure manufacturing method comprising a. The method of claim 12, Between providing the washer and positioning the washer between the head and the fastening portion, Compressing in the longitudinal direction by compression processing below the critical temperature; includes, After the washer is positioned between the head and the fastening portion, Restoring the washer in a longitudinal direction by heating the washer to a temperature higher than the critical temperature. The method of claim 12, Preparing the washer, Providing a coil composed of a shape memory alloy; And cutting a side in the radial direction of the coil in a length direction to provide a plurality of ring-shaped washers.

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