JPH10288215A - Screw-locking method, screw-locking structure, and wrench - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform screw-locking without requiring any operation other than thread fastening, in a clamping tool using screw threads, like bolt and nut. SOLUTION: With a bolt 1 having a male screw 4, a crossed split groove 5 is formed on the tip side from a female screw threading part 4a at which a female screw 6 is positioned when an object to be clamped is clamped. On the other hand, a nut 2 having the female screw 6 is formed into a shape of box nut which surrounds the tip part of the bolt 1 when an object to be clamped is clamped, and forms a projection 8 on the inner bottom part. Thus, the projection 8 formed in the nut 2 cuts into the tip of the bolt 1 simply by performing thread fastening. The tip part of the bolt 1 is split and spread, and thus the screw threads of the bolt and the nut are brought into pressurecontact with each other to perform locking.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for preventing a fastener using a screw thread such as a bolt nut from being loosened by vibration or the like.

[0002]

2. Description of the Related Art The above technique is disclosed in Japanese Patent Laid-Open No. 7-286.
No. 61, Japanese Utility Model Laid-Open No. 6-12819, and the like.

[0003] In the former technique, a knurl is formed on the outer peripheral surface of a tip portion of a bolt member having a male screw, and after a screw is tightened,
The outer peripheral portion of the knurl in the nut member having an internal thread is compressed and deformed by a hydraulic press or a die, and a part of the nut member is cut into the knurl so that the knurl, that is, the bolt member does not rotate.

In the latter technique, a bolt is formed in a hollow shape to hold a pin, and a split groove is formed at the tip of the bolt, and the tip is expanded by driving the pin into the portion. In order to prevent the screw from turning in the loosening direction by expanding the tip of the bolt, the inclined surface is formed.

However, as seen in these techniques,
To prevent the screw from loosening, another operation is required after the screw is tightened. Therefore, quick work could not be expected, and there was an image that the work was troublesome. In addition, a separate tool other than screw tightening was required to perform locking. Further, the conventional locking technology cannot be removed once the locking has been performed.

[0006]

SUMMARY OF THE INVENTION Therefore, the main object of the present invention is to make it possible to automatically prevent loosening by a screw tightening operation.

[0007] The means for this is a method for preventing loosening of a screw in which the distal end side of a female screwed portion of a male screw is expanded to press the threads of the male screw and the female screw against each other. In the jig for rotating the nut, a projection was formed at a portion corresponding to the inner bottom portion of the cap nut shape, and the projection was pressed against the distal end of the male screw according to the rotation of the screw, and formed on the distal end side from the female screwed portion of the male screw. The method is characterized in that it is a method for preventing a screw from being loosened by making it bite into a split groove along the axial direction and expanding the distal end side of the male screw.

[0008] Further, there is provided a means for preventing loosening of a screw for expanding the distal end side of a female screw portion of a male screw to press the threads of the male screw and the female screw against each other. On the side, a split groove is formed along the length direction and divided into a plurality of portions, and the female screw is a portion corresponding to the inner bottom portion imaginary to the female screw of the cap nut, and is fastened by screwing the male screw and the female screw. It is characterized in that it is a screw locking structure in which a projection for making the bite is formed at a position where it bites into the split groove of the male screw when an object is tightened. Note that, in order to be able to remove even after tightening, the protrusion is formed so as to be separable from a nut having a female thread, and a fixing female screw having a prepared hole larger than at least the female screw is formed on the nut. It is good to be integrated.

Still another means is a structure for preventing loosening of a screw in which the distal end side of a female screw portion of a male screw is expanded to press the threads of the male screw and the female screw against each other, wherein the nut having the female screw is a cap nut. It is formed into a shape, and is an inner bottom portion of the shape, which taps from the tip of the male screw to a position where it abuts on the tip of the male screw when tightening an object to be fastened by screwing the male screw and the female screw. It is characterized by a screw loosening prevention structure in which a tapered projection having a thread is formed integrally.

[0010] Still another means is a wrench having a cylindrical fitting recess fitted into the nut, wherein a split groove along the axial direction is formed in the inner bottom of the fitting recess when the nut is rotated. The wrench is formed with a projection that cuts into the distal end portion of the male screw provided on the distal end side from the female screw threaded portion and pushes the split groove apart.

[0011] Still another means is a wrench having a cylindrical fitting recess fitted into the nut, wherein an inner bottom of the fitting recess has a split groove along the axial direction when the nut is rotated. It is a wrench that detachably holds a projection member having a thread for tapping on the outer peripheral surface, which bites into a distal end portion of a male screw having a distal end side from a female screw threaded portion and pushes out the split groove. I do.

[0012]

According to the above-described structure, the screw is prevented from being loosened only by an essential rotation operation. In other words, the protrusion is moved relative to the tip of the bolt with the rotation of the screw and bites into it. Therefore, no operation other than the operation of rotating the screw is required, and another tool is not required, so that the operation can be performed simply and quickly.

That is, in the configuration of the first aspect, the projection formed on the nut member or a jig such as a wrench for rotating the nut member relatively moves with the rotation of the screw and presses against the tip of the male screw. Then, the thread is cut into the groove of the bolt to expand the distal end side of the female screw portion of the male screw so that the threads of the male screw and the female screw are pressed against each other, and at least rotation is prevented in the loosening direction.

According to the second aspect of the present invention, with the rotation of the male screw or the female screw, the projection relatively moves and bites into the split groove formed in the male screw, and when the work is tightened, the protrusion largely enters the split groove of the male screw. By biting in, the distal end side of the female screw threaded portion is expanded. Then, the threads of the male screw and the female screw are pressed against each other, and at least the rotation is prevented in the loosening direction.

[0015] In the case of the third aspect of the present invention, the member having the female screw can be removed by turning and removing the projecting member after tightening the screw to prevent loosening. For this reason, a function that has not been provided in the past is added, and the range of application can be expanded even when the loosening is temporarily stopped. In addition, since the fixing of the protruding member is performed by using a fixing female screw having at least a prepared hole larger than the female screw, if the protruding member is removed, it can be used as a normal nut.

According to the fourth aspect of the present invention, with the rotation of the male screw or the female screw, the projection moves relative to the split groove formed in the male screw, and is threaded with a tapping thread when tightening the work. While digging. At this time, while the rate of advance in the axial direction due to rotation between the male screw and the female screw is constant, the distance traveled by the thread of the tapered projection gradually decreases, that is, the lead (screw of the screw) When making a round around the axis along the winding, there is a difference in the axial distance), so that the progress of the male screw and the female screw in the axial direction is hindered, and the mutual thread faces are pressed against each other. As a result, the rotation is stopped as if tightened by the lock nut and the tightening nut.

According to the fifth aspect of the present invention, simply by fitting the fitting recess into the nut and rotating, the protrusion moves relative to the tip of the male screw, bites into the groove of the male screw, and cuts the groove. Push and deform. As a result, the threads of the male screw and the female screw are pressed against each other, and at least the rotation is prevented in the loosening direction. To remove the nut, it is sufficient to rotate the nut in the loosening direction.

According to the construction of claim 6, the protrusion member is held by the inner bottom portion of the fitting recess and then the fitting recess is fitted to the nut and rotated. Relative movement, biting into the split groove of the male screw while cutting, pushing and expanding. As a result, the threads of the male screw and the female screw are pressed against each other, and at least the rotation is prevented in the loosening direction. When the wrench is removed, the protrusion remains at the tip of the male screw. To remove the nut, first remove the projection member, and then rotate the nut in the loosening direction.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. (First Embodiment) FIG. 1 is a perspective view of a bolt 1 and a nut 2 having a locking structure, and FIG. 2 is a side view showing the nut in cross section. The bolt 1 has an external thread 4 formed on the distal end side of the shaft portion 3, and a cross-shaped split groove 5 formed at the distal end portion along the axial direction with a predetermined length. The formation position is on the distal end side from the female screw threaded portion 4a of the male screw 4 and has a length necessary to enable the expansion deformation by a method described later. The female screw engagement portion 4a is a predetermined position where the female screw of the nut 2 is located when an object (not shown) is tightened by the bolt 1 and the nut 2.

The nut 2 is formed in a cap nut shape, and has the female screw 6 having a predetermined length on the opening side at the lower end. On the upper side of the female screw 6, an expansion space 7 having a larger diameter than that of the female screw is formed, and the upper end surface (the inner bottom of the nut 2) of the expansion space 7 faces the opening. Thus, a conical (tapered) projection 8 is integrally formed.

The projection 8 is provided with the male screw 4 when the object (not shown) is tightened by screwing the bolt 1 and the nut 2 together.
The position, the length, and the inclination angle are set appropriately so as to be able to press into the split groove 5 from the tip of the groove.

In the bolt 1 and the nut 2 configured as described above, the bolt 1 or the nut 2 can be prevented from loosening only by rotating the bolt 1 or the nut 2 in the tightening direction. That is, when the bolt 1 and the nut 2 are rotated, the male screw 4 and the female screw 6 are screwed together,
As shown in FIG. 3, by further applying rotation from this state, when an object (not shown) is tightened, it becomes as shown in FIGS. 4 and 5. In other words, male screw 4
Of the male screw 4 and the female screw 6
Are pressed against each other to prevent rotation at least in the loosening direction. In addition, since the twisting force due to the rotation also acts, the tip of the bolt 1 divided into a plurality of parts by forming the split groove 5 bites into the inner peripheral surface of the expanding space 7 while being twisted.
This provides a more powerful locking.

(Second Embodiment) In this embodiment, a nut 2 composed of a main body member 9 having a female thread and a projection member 10 having a projection 8 is used so that the projection 8 can be separated from the nut 2. Here is an example.

FIG. 6 is an exploded perspective view of the nut 2, and FIG. 7 is a sectional view of the disassembled state. On the upper side of the female screw 6 and the expansion space 7, a fixing female screw 11 having the same diameter as the above-mentioned female screw 6 and having a continuous thread by connecting a virtual line between the female screw 6 and the expansion space 7. And a circular step 12 having a larger diameter than the fixing female screw 11 is formed on the upper side.

The protruding member 10 has a fixing male screw 14 which is screwed to the fixing female screw 11 below a flange portion 13 which fits in the step portion 12, and has a conical (tapered) shape at the lower end surface. Are formed. Further, a cross-shaped notch 15 into which the tip of the driver fits is formed on the upper end surface. This is for attaching and detaching the projection member 10.

Screw tightening using the nut 2 configured as described above to prevent loosening only requires rotating the bolt 1 or the nut 2. As in the case of the first embodiment, loosening can be prevented (see FIG. 8).

When the nut 2 is used, the projection member 10 can be removed, so that the following effects are obtained.
That is, after tightening the screws to prevent loosening (the state of FIG. 8).
Then, if the projection member 10 is removed and the main body member 9 is strongly rotated in the loosening direction, the bolt 1 and the nut 2 can be removed. For this reason, the range of application can be expanded, for example, when the loosening is temporarily stopped.

The projecting member 10 has the same diameter as the female screw 6 and is fixed via a female screw 11 having a continuous thread when the space between the female screw 6 and the expansion space 7 is connected by a virtual line. Therefore, if the projection member 10 is removed in advance, it can be used sufficiently as a normal nut as shown in FIG. The same effect can be obtained even if the diameter of the fixing female screw 11 is larger than that of the female screw 6.

(Third Embodiment) In this embodiment, a female screw 6
The main body member 9 having the projections and the projection member 1 having the projections
An example is shown in which a separate nut 2 is used in which 0 is fitted by fitting.

That is, as shown in FIG. 10, an L-shaped engagement groove 16 cut from the upper end to the lower end is formed in two places on the outer peripheral surface of the main body member 9 having the same shape as a normal hexagon nut. An engagement projection 17 that engages with the L-shaped engagement groove 16 is formed on the inner peripheral surface of the projection member 10, which has a circular inner peripheral surface at its lower part that circumscribes the main body member 9. When the protrusion member 10 is fitted into the main body member 9 and the engagement protrusions 17 and 17 are slid into the engagement grooves 16 and rotated to the right, the engagement protrusions 17 and 17 become L-shaped engagement grooves 16. , 16 so that they cannot be separated when the protruding member 10 is rotated clockwise. Further, a hexagonal column-shaped head 18 is formed on the upper part of the projection member 10 so that the nut 2 can be rotated.

The screw tightening for preventing loosening using the nut 2 configured as described above is performed by fixing the fixing member 10 to the main body member 9.
After fitting and fixing, the bolt 1 or the nut 2 need only be rotated. As in the case of the first embodiment, loosening can be prevented (see FIG. 11).

(Fourth Embodiment) In this embodiment, an example is shown in which a nut 2 having a different locking principle is used. That is,
In the above embodiment, the split groove 5 at the tip of the bolt 1 is pushed out, the tip side of the female screw 4a of the male screw 4 is expanded, and the threads of the male screw 4 and the female screw 6 are pressed against each other and removed. In this embodiment, the protrusion 8 formed on the inner bottom of the nut 2 is cut into the tip of the bolt 1 while being threaded, and the difference in lead is used.
The locking is done.

FIG. 12 is an exploded view of the nut 2. As described above, a female screw 6 having a predetermined length is formed on the opening side, and a hexagonal fitting is formed on the inner bottom of the nut 2 in the form of a cap nut. A hole 19 is formed, and a hexagonal column-shaped head 20 corresponding to the hole 19 is formed in the upper part of the hole 19, and a conical (tapered) screw is formed in the lower part on the outer peripheral surface. The protruding member 10 on which the ridge 21 is formed is integrally formed by bonding with an adhesive or the like.

Screw tightening using the nut 2 configured as described above to prevent loosening is only required to rotate the bolt 1 or the nut 2. With the rotation of the screw, the projection 8 of the projection member 10 relatively moves with respect to the split groove 5 formed in the male screw, and when tightening an object (not shown), the tip 8 of the bolt 1 Biting while tapping with the tapping screw thread. At this time, the tip of the bolt 1 is urged in the expanding direction. Further, while the ratio of the rotation between the male screw 4 and the female screw 6 in the axial direction due to rotation is constant, the distance of the tapered protrusion 8 that advances by the thread is gradually shortened. When making a round around the axis along the helical winding, there is a difference in the axial direction), so that the axial progress between the male screw 4 and the female screw 6 is hindered, and the mutual thread surface becomes Crimp. This allows
The rotation is stopped as if it were tightened with a lock nut and a tightening nut.

Although it is not necessary to form the split groove 5 in the bolt 1, the rotation operation is smoother if at least only a hole for improving the biting is formed.

(Fifth Embodiment) In this embodiment, the nut 2
An example is shown in which loosening is stopped by a configuration provided on a jig (wrench 22) for rotating the tool. That is, this wrench 22
Is an inner bottom of a cylindrical fitting concave portion 23 fitted to the nut 2 as shown in FIG. 14, and when an object to be fastened (not shown) is tightened by screwing the nut 2, At the position where it bites into the split groove 5 formed at the front end of the first thread, a projection 8 that cuts into the front end of the male screw 4 and pushes out the split groove 5 is formed.

At the time of use, the nut 2 is screwed into the bolt 1 having the split groove 5 formed on the tip from the female screw threaded portion 4a of the male screw 4, and the fitting recess 23 is fitted into the nut 2 and tightened. By simply turning it, you can prevent loosening. That is, when the nut 2 is rotated, the projection 8 formed on the wrench 22 presses against the tip of the bolt 1 when the bolt 1 and the nut 2 tighten an object (not shown). Go into 5 and expand. Then, when an object (not shown) is tightened, the state becomes as shown in FIG. That is, the distal end of the male screw 4 expands in the fitting recess 23, and the threads of the male screw 4 and the female screw 6 are pressed against each other to prevent rotation at least in the loosening direction (see FIG. 16).

It is to be noted that the tip of the bolt 1 is
a may be set so that the tip of the bolt 1 does not protrude from the nut 2 during tightening. In this case, the state is as shown in FIG. 17 and the loosening can be stopped. There is an advantage that the material is not wasted, and the tip of the expanded bolt 1 is less likely to receive an external force, so that the bolt can be securely prevented from loosening.

(Sixth Embodiment) In this embodiment, too, the nut 2
An example is shown in which a locking jig (wrench 24) is provided on a jig (rotary wrench 24) to prevent loosening. That is, as shown in FIG. 18, the wrench 24 cuts the split groove 5 along the axial direction from the female screw threaded portion 4 a to the distal end of the male screw 4 provided on the distal end side during the rotation operation of the nut 2. A protruding member 10 that bites and pushes the split groove 5 is detachably held. The projection member 10 has a hexagonal head 2
5, a circular neck portion 26 is formed so as to be in contact with each other and aligned when arranged in a line, and a conical (tapered) projection 8 is formed below the neck portion 26. A thread 27 for tapping is formed on the surface.

The wrench 24 is provided with a handle 29 extending laterally from above a cylindrical fitting recess 28 fitted to the nut 2.
A large number of projection members 10 are urged by urging means 30 to be stored and held therein. In the handle 29, as shown in FIG. 19, a rail 31 is formed to receive under the neck 26 of the protruding member 10 so as to slide, and the head 25 is formed so as to be oriented at a constant direction. ing. Then, the rail 31 is not formed at a position corresponding to the center of the fitting concave portion 28 at the distal end portion, and the projection member 10 at the distal end portion is pulled downward while being held by the urging means 30. In this way, the wrench 24 is separated. When the leading projection member 10 is separated, the next projection member 1
0, and the next projecting member 10 and the urging means 30 are sequentially pushed.

In use, as in the case of the fifth embodiment, a nut 2 is screwed into a bolt 1 having a split groove 5 formed on the distal end side from a female screw threaded portion 4a of the male screw 4, and this nut 2 The loosening can be prevented only by rotating the fitting recess 23 in the direction of fitting and tightening. That is, when the nut 2 is rotated, when the bolt 1 and the nut 2 tighten a workpiece (not shown), the projection 8 formed on the wrench 22 is used.
Is pressed against the tip of the bolt 1, and by further rotation, bites into the split groove 5 while being cut by the thread 27 of the projection 8, thereby expanding. Then, when an object (not shown) is tightened, the state is as shown in FIG. And wrench 24
When the fitting recess 28 is removed from the nut, the projection member 10 is left at the tip of the bolt 1. As shown in FIG. 21, the distal end of the male screw 4 expands in the fitting recess 28, and the threads of the male screw 4 and the female screw 6 of the nut 2 are pressed against each other to prevent rotation at least in the loosening direction. You.

Since the screw thread 27 for tapping is formed on the projection 8 of the projection member 10 as described above, the projection member 10 is provided with the bolt 1 so that the male screw 4 is maintained in the expanded state.
Can be integrated into For this reason, the loosening prevention effect is ensured. Further, since a hexagonal head 26 is formed on the projecting member 10 so that a rotational force can be transmitted, the nut 2 can be removed by rotating and removing the projecting member 10.

The wrench 24 is used for the projection member 10 as described above.
May be fitted and held one by one, and the projecting member 10 may be attached each time the nut 2 is tightened. However, the operability is better with the above-described structure.

Also in this case, the tip of the bolt 1 may be set to the female screw thread 4a so that the tip of the bolt does not project from the nut 2 when tightened. In this case, the projecting member 10 (projection 8) is formed in a conical shape (tapered shape) as shown in FIG. 22, and a thread 27 for tapping is formed on the outer peripheral surface so that the whole is bitten. To The holding of the projection member 10 with respect to the wrench 24 is performed as follows.
For example, a concave portion 32 that fits into a cross-shaped or hexagonal column-shaped protrusion (not shown) formed on the inner bottom surface of the fitting concave portion 28 of the wrench 24 may be formed on the upper end surface of the projection member 10.

[Brief description of the drawings]

FIG. 1 is a perspective view of a bolt and a nut.

FIG. 2 is a partial cross-sectional side view.

FIG. 3 is a partial cross-sectional side view in an operating state.

FIG. 4 is a partial cross-sectional side view in an operating state.

FIG. 5 is a sectional view of the operating state.

FIG. 6 is a perspective view of the nut in a disassembled state.

FIG. 7 is a cross-sectional view of the disassembled state of the nut.

FIG. 8 is a partial cross-sectional side view in an operating state.

FIG. 9 is a partial cross-sectional side view of the operating state.

FIG. 10 is an exploded perspective view of a nut.

FIG. 11 is a partial cross-sectional side view of the operating state.

FIG. 12 is a sectional view showing a disassembled state of the nut.

FIG. 13 is a partial cross-sectional side view in an operating state.

FIG. 14 is a sectional view of a wrench.

FIG. 15 is a partial cross-sectional side view of the operating state.

FIG. 16 is a side view of the locking state.

FIG. 17 is a side view of the locking state.

FIG. 18 is a sectional view of a wrench.

FIG. 19 is a sectional view of a wrench.

FIG. 20 is a partial cross-sectional side view of the operating state.

FIG. 21 is a partial cross-sectional side view of the locking state.

FIG. 22 is a side view of the locking state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Bolt 2 ... Nut 4 ... Male screw 4a ... Female screw threaded part 5 ... Split groove 6 ... Female screw 8 ... Projection 9 ... Body member 10 ... Projection member 11 ... Female screw for fixing 14 ... Male screw 21 for fixing 21 ... Screw 22 ... Wrench 23 ... fitting recess 24 ... wrench 27 ... screw thread 28 ... fitting recess

Claims (6)

[Claims] 1. A method for preventing loosening of a screw in which a distal end side of a female screw portion of a male screw is expanded to press the threads of the male screw and the female screw against each other, wherein the nut having the female screw or the nut is rotated. In the jig to be formed, a projection is formed at a portion corresponding to the inner bottom portion of the cap nut shape, the projection is pressed against the tip of the male screw according to the rotation of the screw, and the projection is formed in the axial direction formed on the tip side from the female screw threaded portion of the male screw. A method to prevent loosening of the screw by cutting the male screw into the split groove 2. A loosening prevention structure for a screw in which a distal end of a female screw portion of a male screw is expanded to press the threads of the male screw and the female screw against each other. A split groove is formed along the length direction and divided into a plurality of portions, and the female screw is a portion corresponding to an inner bottom portion imaginary to the female screw of the cap nut, and the workpiece is tightened by screwing the male screw and the female screw. A screw locking structure in which a projection for making the bite is formed at a position where it bites into the split groove of the male screw when the screw is made. 3. The projection is formed so as to be separable from a nut having an internal thread, and is integrated via a fixing internal thread formed on the nut and having at least a pilot hole larger than the internal thread. The screw locking structure according to claim 2. 4. A loosening prevention structure for a screw, in which a distal end side of a female screw portion of a male screw is expanded to press the threads of the male screw and the female screw together, wherein the nut having the female screw is formed in a cap nut shape. A tapping screw thread which cuts in from the tip of the male screw at the inner bottom portion of the shape and which comes into contact with the tip of the male screw when tightening the workpiece by screwing the male screw and the female screw. Screw loosening structure with integrated tapered projections. 5. A wrench having a cylindrical fitting recess fitted to a nut, wherein a female groove is threadedly engaged with an inner bottom portion of the fitting recess in an axial direction during rotation of the nut. A wrench formed with a projection that cuts into the distal end of a male screw provided on the distal end side from the part and pushes out the split groove. 6. A wrench having a cylindrical fitting recess fitted into a nut, wherein a female groove is threadedly engaged with an inner bottom of the fitting recess along an axial direction during rotation of the nut. A wrench for detachably holding a protruding member having a thread for tapping on an outer peripheral surface, which bites into a distal end portion of a male screw provided on a distal side from a portion and pushes the split groove.