JP2009150492A - Structure for preventing loosening of screw - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a structure for preventing loosening of a screw allowing repetition of fastening and unscrewing without loosening of a screw even under severe use environment such as a change in temperature and vibration. <P>SOLUTION: A V-shape recess in cross section is formed throughout the whole circumference in the cylindrical shape section between the spiral groove section and head section of the screw 4. A screw insertion hole provided in a fastened member 2 is shaped in a figure continuously having an upper small diameter section and a lower large diameter section. A V-shape protrusion in cross section to be fitted in the recess is provided in the inner surface of a sectional ring-shape member 3 fitted in the lower large diameter section. The screw 4 is inserted through the screw insertion hole and the sectional ring-shape member, and screwed in a screw hole 1b provided in a fastening member 1, thereby fastening the fastened member 2 to the fastening member 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a loosening prevention structure for a screw for fastening members together.

  In severe usage environments such as temperature changes and vibrations, the screws that fasten the members may loosen, and the screws may be prevented from loosening. An example of such a conventional screw locking structure will be described with reference to FIGS. FIG. 6 is a sectional view showing an example of a conventional screw locking structure, and FIG. 7 is a side view showing members used in the screw locking structure.

  As shown in FIG. 6, the fastening member 8 is fastened to the fastening member 7 by screwing the screw 9 inserted through the screw insertion hole 8 a of the fastening member 8 into the screw hole 7 a of the fastening member 7. . As shown in FIG. 7, the screw 9 is applied with a locking agent in the locking agent application range 9a.

  After the fastening, when the locking agent is solidified, the screw 9 is bonded to the fastening member 7, and the screw 9 is prevented from coming loose. In some cases, a tapping screw is used as the screw 9, and in this case, the screw hole 7a of the fastening member 7 is a pilot hole.

  In the above-described conventional screw locking structure, the height of the application range of the locking agent (the height indicated by A in FIG. 7) varies, or the amount of the locking agent varies and the locking agent varies. There was a problem that the quality of the product was not constant, such as protruding.

  Also, if it is repeated that the fastening member is repeatedly fastened to or removed from the fastening member, it is inconvenient to prepare a locking agent each time, and it becomes impossible to remove the solid locking agent. There was also a problem that the number of wearing and removing was limited.

  In the structure disclosed in Japanese Utility Model Laid-Open No. 5-37420, the members are fastened with screws. A square groove is formed on the upper surface of the extrusion member 1 serving as a fastening member, and a screw hole 1d is provided in the square groove for mounting. The mounting part 2 is fastened to the pushing member 1 by screwing the screw 3 inserted into the screw insertion hole provided in the part 2 into the screw hole 1d.

In the structure in which the members are fastened with this screw, since the burr generated around the screw 3 is not sandwiched between the pushing member 1 and the mounting part 2, the pushing member 1 and the mounting part 2 are in close contact with each other. However, since the screw 3 is not loosened, the screw that fastens the members may be loosened under severe use environments such as temperature change and vibration.
Japanese Utility Model Publication No. 5-37420, abstract, FIG.

  The present invention has been made in view of the above points, and the object of the present invention is to repeatedly tighten and remove the screw without loosening even in a severe use environment such as temperature change and vibration. An object of the present invention is to provide an anti-loosening structure for screws.

  In the screw locking structure according to the present invention, a V-shaped concave section is formed over the entire circumference in a cylindrical portion between the spiral groove portion of the screw and the head portion, and the screw insertion hole provided in the member to be fastened has an upper small diameter. And a section V-shaped convex part that fits the V-shaped concave section on the inner surface of the partial ring-shaped member that fits into the lower large-diameter part, and the screw The fastening member is fastened to the fastening member by being inserted into the screw insertion hole and the partial ring-shaped member and screwed into the screw hole provided in the fastening member.

  Further, the screw locking structure according to the present invention is formed by forming a V-shaped recess in the cylindrical portion between the spiral groove portion of the screw and the head over the entire circumference, and the screw insertion hole provided in the fastening member. A non-circular recess is formed in the upper part, and the spiral groove of the screw is fitted into the inner surface of the cylindrical part of the stepped ring-shaped member in which a cylindrical part formed with a slit is formed on the head that fits the non-circular recess. Forming a spiral convex portion, and inserting the screw into the screw insertion hole and the stepped ring-shaped member and screwing the screw into a screw hole provided in the fastening member, thereby fastening the fastening member to the fastening member To do.

  In the screw locking structure, the non-circular portion is a hexagonal concave portion.

  Further, in the loosening prevention structure for each screw, the partial ring-shaped member or the stepped ring-shaped member is formed of a synthetic resin.

  According to the screw locking structure of the present invention, the screw can be repeatedly fastened and removed without being loosened even in a severe use environment such as temperature change and vibration.

  The best mode for carrying out the present invention will be described below with reference to examples.

  1 is a sectional view showing a screw locking structure according to Embodiment 1 of the present invention, FIG. 2 (a) is a side view showing members used in the screw locking structure, FIG. 2 (b) and FIG. (C) is a perspective view which shows each member used for the loosening prevention structure of the screw.

  As shown in FIG. 1, the screw 4 is inserted through the partial ring-shaped member 3, and the screw 4 inserted through the screw insertion hole formed by the large-diameter portion 2 a and the small-diameter portion 2 b of the fastening member 2 is inserted. The member to be fastened 2 is fastened to the fastening member 1 by screwing into a screw hole 1 b provided in the boss 1 a of the fastening member 1.

  As shown in detail in FIG. 2 (a), the screw 4 has a V-shaped concave portion 4c formed in the cylindrical shape portion 4c between the head portion 4b and the spiral groove portion 4a over the entire circumferential surface. . Further, as shown in detail in FIG. 2 (b), the synthetic resin partial ring-shaped member 3 has a shape in which a part of the ring shape is cut out, and a V-shaped convex portion 3a is formed on the inner surface. Has been. As shown in detail in FIG. 2C, the boss 1a of the fastening member 1 has a shape in which four ribs are formed on the outer periphery of the cylinder, and is a cross section taken along the line AA in FIG. Is the cross section shown in FIG.

  When the above-described screw 4 is inserted into the partial ring-shaped member 3 and the large-diameter portion 2a and the small-diameter portion 2b of the fastening member 2 are inserted and screwed into the screw hole 1b of the fastening member 1, When the member 2 approaches the fastening member 1, the partial ring-shaped member 3 is pushed up by the fastening member 1.

  The partial ring-shaped member 3 is elastically deformed and expanded while the V-shaped convex portion 3a of the partial ring-shaped member 3 is in contact with the cylindrical shape of the screw 4; Is screwed in to a suitable tightening torque, the V-shaped convex section 3a is fitted into the concave section 4c of the V-shaped section of the screw 4. This state is shown in FIG.

  The fastening state shown in FIG. 1 is a state in which the fastened member 2 is fastened to the fastening member 1 with an appropriate tightening torque. In this state, when the screw 4 is turned in the removing direction, the cross section V of the screw 4 is shown. The partial ring-shaped member 3 is elastically deformed by pushing the V-shaped convex part 3a of the cross-section of the partial ring-shaped member 3 with the letter-shaped concave part 4d, but this requires a large torque.

  Since the screw 4 does not turn easily as described above, the screw 4 is not loosened even in a severe use environment such as temperature change and vibration, and the screw 4 is not adhered. Can be repeated. As the material of the partial ring-shaped member, it is preferable to select a material that can be easily removed by tightening and has a sufficient elasticity to prevent loosening.

  3 is a sectional view showing a screw locking structure according to a second embodiment of the present invention, FIG. 4 is a perspective view showing a member of the screw locking structure, and FIG. 5 is another member of the screw locking structure. It is a perspective view which changes each and shows a state.

  As shown in FIG. 3, the screw 4 is inserted through the stepped ring-shaped member 6, and the screw 4 inserted through the screw insertion hole 5 c of the fastening member 5 is provided in the boss 1 a of the fastening member 1. The member to be fastened 5 is fastened to the fastening member 1 by being screwed into the screw hole 1b.

  The same screw 4 and fastening member 1 as in the first embodiment are used. However, the screw 4 is drawn with the outer diameters of the spiral groove portion 4a and the cylindrical portion 4c being greatly changed for the sake of simplicity of illustration, but these outer diameters are substantially equal.

  As shown in detail in FIG. 4, the screw member 5a has a shape in which a hexagonal recess 5b is formed in the upper part of the cylindrical hole 5c. As shown in detail in the perspective views of FIGS. 5A and 5B and the partially cutaway perspective view of FIG. 5C, the stepped ring-shaped member 6 made of synthetic resin has a hexagonal head 6a. The cylindrical part 6b which has a slit is connected to the lower surface of the cylindrical part 6b, and a helical convex part 6c that fits the helical groove 4a of the screw 4 is formed on the inner surface of the cylindrical part 6b.

  When the screw 4 described above is inserted into the stepped ring-shaped member 6 and further inserted into the screw insertion hole 5a of the fastening member 5 and screwed into the screw hole 1b of the fastening member 1, the screw 4 is initially spiraled. The groove 4 a is screwed into the screw hole 1 b of the fastening member 1, the fastened member 5 approaches the fastening member 1, and the stepped ring-shaped member 6 is pushed down by the head 4 b of the screw 4.

  Then, after the hexagonal head 6a of the stepped ring-shaped member 6 is fitted into the hexagonal recess 5b of the fastening member 5, the stepped ring-shaped member 6 rises with respect to the screw 4 and spirals. The convex portion 6 c is elastically deformed and rides on the cylindrical portion 4 c of the screw 4.

  Further, when the screw 4 is screwed in to an appropriate tightening torque, the spiral convex portion 6c is elastically deformed and fitted into the V-shaped concave portion 4c of the screw 4. This state is shown in FIG. The fastening state shown in FIG. 3 is a state where the fastened member 5 is fastened to the fastening member 1 with an appropriate fastening torque.

  In this state, when the screw 4 is turned in the direction to remove, the spiral convex portion 6c of the stepped ring-shaped member 6 is elastically deformed by the V-shaped concave portion 4c of the screw 4 and rides on the cylindrical portion 4c of the screw 4. However, a large torque is required for this purpose.

  Since the screw 4 does not turn easily as described above, the screw 4 is not loosened even in a severe use environment such as temperature change and vibration, and the screw 4 is not adhered. Can be repeated. The hexagonal head 6a of the stepped ring-shaped member 6 has a small outer diameter and transmits a large torque by the contact pressure of the outer surface, and is thus a shape suitable for a synthetic resin having a low strength.

  In this embodiment, it is only necessary to place the stepped ring-shaped member 6 on the member to be fastened 5 and screw the screw 4 in, so that the assembly is simplified.

It is sectional drawing which shows the locking structure of the screw which is Example 1 of this invention. FIG. 2A is a side view showing a member used in the locking structure for the screw, FIG. 2B is a perspective view showing another member used in the locking structure for the screw, and FIG. It is a perspective view which shows the other member used for the locking structure of the screw. It is sectional drawing which shows the locking structure of the screw which is Example 2 of this invention. It is a perspective view which shows the member of the locking structure of the screw. It is a perspective view which shows each state of the other member of the locking structure of the screw. It is sectional drawing which shows the example of the conventional screw locking prevention structure. It is a side view which shows the member used for the locking structure of the screw.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fastening member, 1a boss, 1b Screw hole 2 Fastened member, 2a Large diameter part, 2b Small diameter part 3 Partial ring-shaped member, 3a Cross-section V-shaped convex part 4 Screw, 4a Spiral groove part, 4b Head part, 4c Cylinder Shaped part, 4d Sectional V-shaped concave part 5 Fastened member, 5a Screw insertion hole, 5b Hexagonal concave part, 5c Cylindrical hole 6 Stepped ring-shaped member, 6a Hexagonal head, 6b Cylindrical part, 6c Spiral convex part 7 Fastening member, 7a Screw hole 8 Fastened member, 8a Screw insertion hole 9 Screw, 9a Loosening agent application range

Claims (4)

A V-shaped concave section is formed in the cylindrical portion between the spiral groove portion and the head of the screw over the entire circumference, and the screw insertion hole provided in the fastening member has a shape in which the upper small diameter portion and the lower large diameter portion are continuous. A V-shaped convex section that fits with the V-shaped concave section is provided on the inner surface of the partial ring-shaped member that fits into the lower large-diameter section, and the screw is inserted into the screw insertion hole and the partial ring-shaped member. A screw loosening prevention structure for fastening the member to be fastened to the fastening member by screwing into a screw hole provided in the fastening member. A recess having a V-shaped cross section is formed over the entire circumference in a cylindrical portion between the spiral groove portion of the screw and the head, and a non-circular recess is formed in an upper portion of a screw insertion hole provided in the fastening member. A spiral convex portion that fits into the spiral groove portion of the screw is formed on the inner surface of the cylindrical portion of the stepped ring-shaped member in which a cylindrical portion having a slit formed on the head portion that fits into the concave portion is formed, and the screw is A screw locking structure for fastening the member to be fastened to the fastening member by being inserted into the screw insertion hole and the stepped ring-shaped member and screwed into a screw hole provided in the fastening member. The screw locking structure according to claim 2, wherein the non-circular portion is a hexagonal recess. The screw locking structure according to any one of claims 1 to 3, wherein the partial ring-shaped member or the stepped ring-shaped member is formed of a synthetic resin.

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