WO1989011044A1

WO1989011044A1 - Locking screw

Info

Publication number: WO1989011044A1
Application number: PCT/JP1989/000456
Authority: WO
Inventors: Takuya Mikajiri
Original assignee: Takuya Mikajiri
Priority date: 1988-05-09
Filing date: 1989-05-01
Publication date: 1989-11-16

Abstract

When force acts on a conventional screw in a direction opposite to a mutual surface pressure direction due to vibration or the like after tightening is completed, mutual surface shifting occurs and a drop in restriction force against the surface shifting due to a drop in the mutual surface pressure occurs so that loosening of the screw is likely to occur. In the screw of the present invention, a projection is disposed at the valley portion of a female screw so that the force of displacement acts on the tip of the screw thread of a male screw in a male screw driving direction when the screw is driven. The screw of the present invention can be driven up to the intermediate stage of driving in the same way as the conventional screw and at the final stage, it is driven with a predetermined torque and the tip of the male screw is bent and deformed at the valley portion of the female screw, thereby preventing any play between the screw surfaces of the male and female screws. Since the projection which the tip of the male screw anchors engages is provided on the female screw, the loosening of the male screw can be prevented reliably. Once driving is completed, therefore, loosening can be restricted and even if it occurs, fall-off of the screw can be prevented.

Description

Specification

Set screw

〔Technical field〕

The present invention relates to a locking screw for preventing or reducing the occurrence of loosening in a screw and the continuation of the loosening.

(Background technology)

Fig. 10 shows the structure of a conventional general screw. In the figure, 1 is a male screw and 2 is a female screw. Generally, in the process of tightening the screws, almost no surface pressure is applied to the mutual screw surfaces of the male screw 1 and the female screw 2 as shown in Fig. 11A. Therefore, the surface pressure that restrains the surface movement of each other is not obtained, and the external thread 1 can move freely while rotating from the viewpoint of the female screw 2. At this time, if the male screw 1 in FIG. 11A moves in the direction of the arrow in the figure, the state shown in FIG. 11B is obtained. In this state, as shown in the figure, the upper surface of the male screw 1 is brought into close contact with the lower surface of the female screw 2 and a surface pressure is obtained between them. Further, by rotating the male screw 1 clockwise as viewed from the top in FIG. 10, the surface pressure per unit area increases, and as a result, the pressure increases the restraining force against the surface movement between each other. The tightening vat _Γ.

However, in the state shown in Fig. 11B, the external thread 1 receives the force to move in the direction of the arrow in the figure or the internal thread 2 moves in the direction opposite to the arrow due to some cause such as vibration. When the force is applied, the contact pressure between male screw 1 and female screw 2 decreases. Furthermore, when the male screw 1 is viewed from above in FIG. 10, the male screw 1 often rotates counterclockwise. Once this situation occurs, the mutual surface pressure per unit area decreases, even if the mutual surface movement is temporarily stopped. Therefore, when the movement is added again, the slack occurs, and as a result, • The effectiveness of the tightening is lost.

• This situation is used for fastening parts such as aircraft and automobiles.-If it occurs in bolts and nuts, it will lead to a big picture.

5 The present invention relates to a conventional screw, in which the mutual transfer and movement that occur when a force is applied by a vibration action or the like in the direction opposite to the mutual contact pressure after the completion of the tightening, and further decrease in the mutual contact pressure The purpose is to improve both the lowering and lowering of the restraining force on the surface movement due to the friction and to maintain the tightening force for a long time.

0 [Disclosure of the Invention]

-In order to achieve this object, a locking screw according to the present invention is a screw comprising a male screw and a female screw, wherein a screw is screwed into a valley portion of the female screw at the tip of the thread of the male screw at the time of attachment. Along the direction • It is characterized by the provision of a projection that acts on the deformation force.

5 By forming a wedge that is easy to deform in the direction of screw tightening at the tip of the screw thread of the male screw, the screw tip of the male screw contacts the root of the female screw with a relatively small tightening torque. Can be in contact.

* Instead of providing a projection at the root of the female screw in the locking screw, instead of providing a projection in the middle of the wedge portion, which comes into contact with the 0 female screw surface of the female screw prior to screw tightening. Is also good.

* Further, the second loosening set screw of the present invention is a screw comprising a male screw and a female screw, wherein a screw extends from a valley portion of a leading screw surface of the male screw to a middle part of the height of the male screw. A first screw surface that is parallel to the chevron and has a predetermined distance ♦, and a portion of the 5th thread from the first screw surface to the reference chevron of the screw thread is substantially perpendicular to the axis of the male screw. And a notch portion cut out from the reference angle is formed on the delay side screw surface of the male screw. As the female screw of this locking screw, a standard product can be used.However, a detent projection with which the male screw head engages when the male screw is tightened is formed on the delay screw surface near the root of the female screw. Things can be used.

Another set screw according to the present invention is a screw comprising a male screw and a female screw, wherein a predetermined portion of a thread from a valley of a leading screw surface of the male screw to a middle portion of the height of the male screw is parallel to a reference angle. A first threaded surface having a distance, a portion extending from the first threaded surface to the tip of the thread being a second threaded surface substantially perpendicular to the axis of the male screw, and a valley of the female screw; A loosening set screw having a detent projection formed on a nearby leading screw surface with which the male screw head engages when the front male screw is tightened can be provided.

Further, a recess is formed in the middle of the leading screw surface of the male screw, and a detent projection is formed in the middle of the leading screw surface of the female screw to engage the ω portion of the male screw when tightened. A detent protrusion with which the male screw head engages may be formed on a nearby delay side screw surface. .

Furthermore, the same effect can be obtained even if the relationship between the male screw and the female screw is reversed.

[Brief description of drawings]

1 and 2 are sectional views of the first embodiment of the present invention, FIGS. 2A and 2B are sectional views of the second embodiment of the present invention, FIGS. 3A and 3B Figures are cross-sectional views of a third embodiment of the present invention, Figs. 4A and 4B are cross-sectional views of a fourth embodiment of the present invention, and Figs. 6A and 6B are cross-sectional views of a sixth embodiment of the present invention. FIGS. 7A and 7B are cross-sectional views of a seventh embodiment of the present invention. FIGS. A and 8B are cross-sectional views of the eighth embodiment of the present invention, and FIGS. 9A and 9B are ninth embodiments of the present invention. FIG. 10 is a cross-sectional view showing the structure of a conventional screw, and FIGS. 11A and 11B are cross-sectional views for explaining the problem of the conventional screw.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be specifically described based on embodiments shown in the drawings. 1A and 1B show a first embodiment of the present invention. In the present embodiment, a bending projection 22 protruding from the female screw surface 21 is formed at a valley portion of the female screw 20. FIG. 1A shows a state before the completion of the tightening, and FIG. 1B shows a state after the completion of the tightening. In the present embodiment, before the tightening is completed, no surface pressure is generated on the opposing screw surfaces 11, 21 of the male screw 10 and the female screw 20, as shown in FIG. 1A. When the male screw 10 is tightened, the surface of the female screw surface 21 viewed from the male screw surface 11 rises while moving relatively as viewed from the male screw surface 11, and FIG. The mutual relationship changes to the figure. As a result, the male screw tip 11a receives a downward bending pressure, and the position of the male screw tip 11a moves as shown in FIG. 1B. By the action described above, at the position of the distal end portion 11a of the male screw in FIG. 1B, a downward surface pressure is applied from the male screw 10 side to the female screw 20 side, and the male screw 10 is downwardly viewed from the female screw 20. It is difficult to move. However, since the surface pressure from the bottom of the female screw 20 to the top of the female screw 20 as viewed from the male screw 10 can be obtained in the same manner as the conventional screw, the male screw 10 applies the same tightening completion surface pressure to the female screw 20 as the conventional one. It is the one that worked. Moreover, since the distal end 11a of the male screw 10 once bent is located at almost a right angle to the mutual surface pressure, it is very difficult to return to the state shown in FIG. 1A. Therefore, even if vibration is applied such that a downward force acts on the male screw 10, the downward surface pressure is inversely proportional to the surface pressure of the male screw surface 11 and the female screw surface 21, and attempts to hinder the mutual surface movement. Work. In addition, after the tightening is completed, Since a certain surface pressure is applied due to the deformation of the thread tip 11a, even if a temporary slight loosening occurs, it itself suppresses a sharp decrease in the tightening effect and suppresses mutual screw surface movement. Due to this effect, even if a slight surface movement occurs between the screws, unlike a conventional screw, a certain surface pressure is maintained between them. Can be obtained.

2A and 2B show a second embodiment of the present invention. In the present embodiment, the tip of the crest of the male screw 10 is formed with a notch 12 to form a thin wedge 13 so as to reduce the torque required for deformation of the male screw tip. FIG. 2A shows a state before the completion of the tightening, and FIG. 2B shows a state after the completion of the tightening. In this embodiment, when shifting from the state of FIG. 2A to the state of FIG. 2B, the portion of the male screw tip 13a receives a bending pressure below the bent portion 13b, and It will be pressed against the female screw surface with a smaller torque than in the case. Other functions and effects are the same as those of the first embodiment.

FIGS. 3A and 3B show a third embodiment of the present invention. In order to make it easy to bend the end of the male screw 10 when tightening, the bottom 23 of the valley of the female screw 20 is cut. It is formed in a trapezoidal shape instead of a triangular shape. Fig. 3 は shows the state before the tightening is completed, and Fig. 3B shows the state after the tightening is completed. Other configurations, operations, and effects are the same as in the first embodiment.

4A and 4B show a fourth embodiment of the present invention, in which a step is provided between the screw surface 11 of the male screw 10 and the male screw tip 11a, and the step is formed by a female screw surface. It is smaller than the step between the projection 21 and the projection 22. FIG. 4A shows a state before the completion of the tightening, and FIG. 4B shows a state after the completion of the tightening. Even with such a shape of the thread of the male screw 10, the same operation and effect as in the above-described embodiment can be obtained. FIGS. 5A and 5B show a fifth embodiment of the present invention, which differs from the first to fourth embodiments in the means of deformation of the thread tip in the tightening process. The wedge portion 13 of the male screw 10 itself has a projection 13c that causes deformation. After the final tightening is completed, the same effect as in the above embodiment is exerted. Fig. 5A shows the state before the tightening is completed, and Fig. 5 BIT shows the state after the tightening is completed.

The protrusions 22 or 13 c that cause deformation at the bottom of the valley of the female screw 20 with respect to the tip 11 a or the wedge 13 of the male screw 10 are different from those of the above embodiment in that the male screw 10 and the female screw 20 The same effect can be obtained even if the relationship is reversed. Further, both the male screw 10 and the female screw 20 may be provided with a structure that deforms the wedge portion 13 when the male screw 10 is tightened.

6A and 6B show a sixth embodiment of the present invention. Fig. 6A shows the state before the completion of the tightening, and Fig. 6B shows the state after the completion of the tightening.

In the present embodiment, the female screw 20 having the same thread and valley as the conventional one is used.

The male screw 10 is defined as a first screw surface 14a having a predetermined distance parallel to the reference angle A and extending from the root of the screw surface on the leading side of the male screw to an intermediate portion of the height of the male screw. The portion from the thread surface 14a of the male thread to the reference angle portion 15 of the thread is defined as a second thread surface 14b substantially perpendicular to the axis of the male screw, and the reference thread A It has a shape formed with a notch 12 which is notched.

In this embodiment, before the tightening is completed, as shown in FIG. 6A, no surface pressure is generated on the leading screw surfaces 15 and 21 of the male screw 10 and the female screw 20 which are opposed to each other. When the male screw 10 is tightened, the surface of the female screw surface 21 as viewed from the first screw surface 14a is relatively flat as viewed from the first screw surface 14a. As a result, the relationship rises from FIG. 6A to FIG. 6B. As a result, the position of the intersection a between the first screw surface 14 a and the second screw surface 14 b moves parallel to the axis of the male screw 10 to reach a ′, but the second screw surface 14 b The intersection b between the reference angle 15 and the reference angle 15 is dragged by the deformation of the second thread surface 14b to reach the position b '. As a result, the position of the distal end 13 a of the male screw 10 moves to a state of being pressed against the delay-side screw surface of the female screw 20. The notch portion 12 is formed to facilitate deformation when a portion at the tip of the second screw surface 14b is deformed.

By the action described above, at the position of the male screw tip 13a in FIG. 6B, a downward surface pressure is applied from the male screw 10 side to the female screw 20 side, and the male screw 10 is viewed from the female screw 20, It is difficult to move down. However, since the surface pressure from the bottom to the top of the female screw 20 as viewed from the male screw 10 is obtained in the same manner as the conventional screw, the male screw 10 applies the same tightening completion surface pressure to the female screw 20 as the conventional one. It is the one that worked. However, it is extremely difficult to return to the state shown in FIG. 6A since the tip 13a of the male screw 10 once bent is located almost at right angles to the mutual surface pressure. Therefore, even if vibration is applied so that a downward force acts on the male screw 10, the downward surface pressure does not affect the surface pressure of the first and second thread surfaces 14 a, 14 b and the female screw surface 21. It is inversely proportional and works to prevent plane movement between each other. Moreover, after the tightening is completed, a constant surface pressure is applied to the female screw 20 as viewed from the male screw 10 due to the deformation of the thread tip 13a, so even if a temporary slight loosening occurs, Reduces sudden tightening effect and prevents mutual screw surface movement. Due to this effect, even if slight surface movement occurs, unlike a conventional screw, a certain surface pressure is maintained between each other, so it does not lead to sudden loosening, and the continuity of the tightening effect Can get • Note that the relationship between the height X of the first screw surface 14a and the height Y of the second screw surface 14b is determined when the state shown in FIG. 6A shifts to the state shown in FIG. 6B. * Consider the thread angle so that the tip 13a is pressed against the female screw surface.

5 FIGS. 7A and 7B show a seventh embodiment of the present invention. In the present embodiment, a detent protrusion 22 is formed on the delay side screw surface near the root of the female screw 20 to engage with the male screw tip 13 a when the male screw 10 is tightened. The shape of the male screw 10 is the same as in the sixth embodiment.

* Fig. 7A shows the state before the tightening is completed, and Fig. 7B shows the state after the tightening is completed.

. In this embodiment, the state shown in FIG. 7A is changed to the state shown in FIG. 7B-immediately before, the thread tip 13 a of the male screw 10 is moved to the protrusion 22 of the female screw 20 * to deform the male screw 10. Prevent the return of the thread to its previous state. In the case of the first embodiment, the return-preventing action is performed solely by contacting the thread tip 13a of the male screw 10 with the valley surface of the female screw 20.5. -Therefore, machining of the thread of the male thread 10 required precision and was mistakenly machined. In this case, the leading end 13a of the male screw 10 does not generate a contact surface pressure against the screw surface of the female screw 20 on the delay side, so that the effect as a locking • may not be exhibited. In the second embodiment, in addition to simply preventing the zero displacement due to the contact effect, and providing the protrusion 22 for preventing the return of the screw thread *, even if there is some processing error, • The effect of preventing return is expected.

• FIGS. 8A and 8B show an eighth embodiment of the present invention. In this embodiment, the first threaded surface 14a, which is parallel to the reference angle and has a predetermined distance, from the root of the leading threaded surface of the external thread 10 to the middle of the height 25 of the external thread is used. , From the first thread surface 14a to the tip 13a of the thread • a portion is defined as a second thread surface 14b substantially perpendicular to the axis of the male screw 10; And a male screw is formed on a leading screw surface near a valley portion of the female screw 20 by forming a detent projection 24 to which the male screw tip 13a is sometimes engaged. Fig. 8A shows the state before the tightening is completed, and Fig. 8B shows the state before the tightening is completed.

• The status after completion is shown.

5: In this embodiment, the difference between the slope distances of the two threads • when the male screw 10 and the female screw 20 are deformed is used. In other words, the top of the male screw 10 has a straight bottom surface and a broken top surface • before tightening. However, when the tightening is completed, a downward force • is applied to the top of the male screw 10. As a result, the first threaded surface 14a and the second threaded surface 14b are straightened. At this time, the second screw-face 14 b is deformed to the position of a ′ ~ (: ′ on the female screw face 21. A '~

• Since the length of, c 'is equal to the length of a to c, the tip 13a of the male screw 10 moves over the protrusion 24 to the state shown in FIG. 8B. Once the condition shown in Fig. 8B is reached, even if the screw becomes loose i, the tip 13a of the male screw 10 cannot go over the protrusion 15 24, so the loosening will not progress further.

• It has an anti-loosening effect.

-FIGS. 9A and 9B show a ninth embodiment of the present invention. -In this embodiment, a recess 18 is formed in the middle of the leading screw surface of the male screw 10, and the detent engages with the recess 18 of the male screw 10 when tightening in the middle of the leading screw surface of the female screw 20. A projection 25 is formed, and a return stop projection 22 with which the male screw tip 13a is engaged is formed on the delay screw surface near the root of the female screw 20. Fig. 9A shows the state before the tightening is completed. ♦ Fig. 9B shows the state after the tightening is completed.

-This fourth embodiment is a combination of the configurations of the second and third embodiments, 5 and has two projections 18 and 22 on both the leading screw surface and the delay screw surface of the female screw 20. A heavy detent effect can be expected.

* Note that the relationship between male screw 10 and female screw 20 is Can obtain the same effect.

As described above, in the present invention, in the middle of the tightening, the screw can be tightened in the same manner as the conventional screw, and in the final stage, by tightening with a predetermined torque, the distal end of the male screw is It bends and deforms at the valleys, suppressing the play between the external thread and the internal thread. Also, by providing the female screw with a projection that locks the distal end of the male screw when the male screw is deformed, the return of the male screw can be reliably prevented. Therefore, once the tightening is completed, it is possible to suppress the loosening, and even if the loosening occurs once, it is possible to prevent further dropping of the screw. The same effect is obtained even if the relationship between the male screw and the female screw is reversed.

[Industrial applicability]

The locking screw according to the present invention can be used particularly in bolts and nuts used for fastening parts of aircraft, automobiles, and the like, in which falling off of the screw is a serious problem.

Claims

The scope of the claims

1. A screw comprising a male screw and a female screw, characterized in that a projection is provided at a valley portion of the female screw at the tip of the screw thread of the male screw at the time of screw tightening to apply a deforming force in the direction of tightening the male screw. And set screws.

2. The locking screw according to claim 1, wherein a wedge portion that is easily deformable in a screw tightening direction is formed at a tip of a thread of the male screw.

3. In a screw composed of a male screw and a female screw, a wedge portion that is easily deformable in the screw tightening direction is formed at the tip of the thread 0 of the male screw, and the female screw is formed in a middle portion of the wedge portion when the screw is tightened. A locking screw characterized by having a projection which comes into contact with the female screw surface of the screw member in advance.

'4. In the case of a screw consisting of a male screw and a female screw, the first thread that is parallel to the reference angle and has a predetermined distance from the valley of the 5 thread surface on the leading side of the male screw to the middle of the height of the male screw. A portion extending from the first thread surface to the reference angle of the thread is defined as a second thread surface substantially perpendicular to the axis of the male screw, and A locking screw characterized by forming a notch in the base angle. 0

5. A locking screw according to claim 4, wherein a detent projection is formed on the delay screw surface near the root of the female screw so that the male screw head engages when the male screw is tightened.

6. In a screw consisting of a male screw and a female screw, the first thread which is parallel to the reference angle and has a predetermined distance from the valley of the thread surface on the leading side of the male thread to the middle of the height of the male thread. A portion extending from the first thread surface to the tip of the thread is a second-thread surface substantially perpendicular to the axis of the male screw, and a lead near the root of the female screw is formed. On the side screw surface, A locking screw characterized by forming a detent projection with which the male screw head engages when the male screw is tightened.

7. A recess is formed in the middle of the leading screw surface of the male screw according to claim 4, and a stopper projection is formed in the middle of the leading screw surface of the female screw to which the recess of the male screw engages when tightened, and A locking screw, wherein a detent projection with which the male screw head engages is formed on the delay screw surface near the root of the female screw.

8. The locking screw according to any one of claims 1 to 7, wherein the relationship between the external thread and the internal thread is reversed.