JP2010121695A - Bolt locking structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bolt locking structure with a constitution that can prevent an increase in manufacturing cost. <P>SOLUTION: The bolt locking structure is a bolt locking structure with a bolt 12 and a lock washer into which the bolt is inserted, and the lock washer is provided with a plurality of claws 1a in the direction of a physical object 9, a first lock washer 3 equipped with inserting holes having a shape except a circle formed as an inserting part of the bolt 12 and a plurality of claws 4a in the head part direction of the bolt 12, each claw 4a linking with the claw 1a of the first lock washer 3 to form a pair with the first lock washer 3, and a second lock washer 7 provided with a plurality of projections 5a for fixing to the physical object 9. Each claw 1a of the first lock washer 3 and each claw 4a of the second lock washer 7 are following sea direction to rotation in the direction fastening each bolt 12 and are inclined to head sea direction against rotation in the direction releasing the bolt. The bolt 12 is also characterized in that an engaging part 8 with a shape fitting to the through hole of the first lock washer 3 is provided on the head bottom surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a bolt locking structure, and more particularly to a bolt and a washer structure through which the bolt is inserted.

  Spring washers are well known as members that prevent unintentional loosening of fasteners such as bolts and small screws.

The spring washer is made of an annular material such as spring steel and has a notch in a part of the circumferential direction to make the whole a little twisted, thereby providing a step between the notches facing each other. It is.
By adopting such a shape, when the fastener such as a bolt is tightened, the stepped portion is pressed, and the shape restoring force due to elasticity acts on the screw surface of the bolt as a pressure for preventing the bolt from loosening. It has become.

  On the other hand, in recent years, a washer that prevents the bolt from loosening by preventing rotation of the bolt itself has been proposed (for example, “Patent Document 1”, etc.) in addition to the pressing action on the screw surface by the shape restoring force. .

  In Patent Document 1, for the purpose of fastening a bolt and a nut, a locking sawtooth that engages with a serrated engaging portion formed on one end surface in the axial direction of the nut is provided on one end surface in the thickness direction of the washer. The structure which provided the convex part engaged with the slit formed in the axial part of the volt | bolt in the part of the periphery of the volt | bolt insertion hole formed in the center part of the washer is disclosed.

  In this structure, the bolt and the washer are integrated with respect to the rotation direction by engaging the protrusion on the washer side with the slit on the bolt side, and the nut and the washer are integrated by the engagement of the sawtooth portion to loosen the bolt, In other words, the bolt is prevented from turning inadvertently.

  As a structure to prevent the bolt from loosening by the engagement relationship between both the bolt and the nut, a plurality of protrusions are provided near the periphery of the bolt insertion hole on one end surface in the axial direction of the nut, and the nut is screwed into the bolt. There is a configuration in which when the nut is tightened, the protrusion of the nut is caused to bite into the screw portion of the bolt (for example, “Patent Document 2”).

  The engaging part of the bolt head underside and the engaging hole of the washer to be inserted into the screw shaft part match each other and rotate integrally. Radiation teeth are formed on the entire outer peripheral edge of the washer. The cross-sectional shape is such that the hypotenuse tooth side in the bolt fastening direction is higher than the hypotenuse tooth in the direction opposite to the fastening direction, and the radiating tooth fitting that fits the radiating tooth on the seat surface of the object in contact with the washer A structure for preventing loosening of bolts or the like characterized by providing a joint is also proposed (see Patent Document 3).

In Patent Document 4, two or more legs are provided in the lower part of a cylindrical or umbrella-shaped washer, and these legs are compressed when pressed against an object to be tightened by tightening screws, and a restoring spring force is stored in an energy. In addition, a locking washer and screws have been proposed in which a fitting protrusion formed on the washer is fitted into a fitting receiving portion of a bolt or nut so that the bolt or nut is not loosened.
In addition, various types of locking structures including a washer rotation stop structure for an object and a bolt rotation stop structure for a washer have been proposed.

Japanese Patent Application Laid-Open No. 2003-120643 JP 11-315820 A Japanese Utility Model Publication No.59-96418 JP 2006-307963 A

  However, the loosening prevention structure disclosed in Patent Document 1 merely prevents the rotation of the bolt by establishing an engagement relationship between the washer side and the bolt side or the nut side. For this reason, it is necessary to provide not only the washer but also a saw-tooth-like engaging portion which is one of the engaging portions on the nut side facing the washer.

  In such a structure, it is necessary to mold a nut having a structure that can be engaged with a serrated engaging portion formed on the washer side, using a mold or the like. For this reason, there is a possibility that the number of parts for the engagement, the processing cost, and the part management cost will increase. Further, when the bolt is tightened, the nut moves at the same time.

  On the other hand, in the locking structure disclosed in Patent Document 2, the bolt cannot be rotated by utilizing the crushing of the protrusion, and therefore the nut cannot be reused. For this reason, after the bolt is loosened, the function of preventing the loosening is lost even if an attempt has been made to use the nut that has been used for the purpose of preventing the loosening again. Therefore, it is necessary to prepare a new nut. Further, a lot of nuts must be used, and the nuts must be molded with a mold or the like. Therefore, even in this structure, there is a risk that the parts management cost will be high.

  According to the locking structure described in Patent Document 3 and Patent Document 4, and other conventional locking structures such as bolts and nuts, the shape of the washer used in combination with the bolt and the bolt is complicated. In addition, the material is compression molded and cannot be manufactured unless it undergoes a complicated molding process, and it can be used only for special purposes that can be used at a high cost.

  An object of the present invention is to provide a structure in which a washer can be processed at low cost only by press working using a sheet metal, and the washer whose projecting part bites on an object does not rotate together with a bolt in view of the problems in the conventional fastening washer. Therefore, the bolt can be tightened without damaging the object, and the material elasticity of the washer and the direction of follow-up against rotation of the bolt are opposite to the rotation of the bolt in the loosening direction. Provided is a bolt loosening prevention structure that can prevent loosening of a bolt by a claw inclined in a wave direction, and can handle the bolt and the first washer substantially as one component, thereby enhancing the convenience of handling. There is.

  In order to achieve the above object, the present invention is a bolt loosening prevention structure including a bolt and a washer through which the bolt is inserted, and the washer includes a plurality of claws in the direction of the object, and is formed as a bolt insertion part. A first washer having an insertion hole of a shape other than a perfect circle and a plurality of claws in the bolt head direction, and these claws engage with the claws of the first washer and pair with the first washer A second washer having a plurality of protrusions to be fixed to the object, and the claws of the first washer and the claws of the second washer The rotation direction is the trailing wave direction, and the rotation of the bolt in the loosening direction is inclined in the opposite wave direction. The bolt can be fitted into the insertion hole of the first washer on the bottom of the head. The main feature is that a locking portion is provided.

The thickness (L1) of the first washer and the thickness (L) of the locking portion on the bolt side are preferably L1> L.
The plurality of claws provided on the first washer and the second washer are in a follow-up direction with respect to rotation of the bolt in the fastening direction, and are opposed to rotation in the loosening direction of the bolt. If it is inclined in the direction, the bolt can be mechanically resisted in the slack direction, and the first and second washers can be designed so that the claws engage with each other.
The first washer may be integrated with the bolt by press-fitting a locking portion of the bolt into the insertion hole.

According to the present invention, the object includes a plurality of claws, a first washer having an insertion hole having a shape other than a perfect circle formed as a bolt insertion portion, and a plurality of claws in the bolt head direction. A first washer and a second washer comprising a plurality of protrusions for engaging the claws of the first washer with the claws of the first washer and being fixed to the object. The plurality of claws are in a follow-up direction with respect to rotation in the bolt tightening direction, and are inclined in the opposite wave direction with respect to rotation in the loosening direction of the bolt. By providing the engaging portion having a shape that can be fitted into the insertion hole of the one washer, a structure for dynamically resisting the loosening of the bolt is provided, and the loosening of the bolt can be prevented.
In addition, the projection of the second washer is in close contact with the contact surface of the object and acts on the screw surface of the bolt using the shape restoring force generated by bending at least one of the first and second washers. Therefore, it is possible to increase the friction force on the screw surface and prevent loosening.

As a result, the configuration necessary for preventing loosening can be completed with only a washer and a bolt that are simply processed into a sheet metal, and the manufacturing cost can be reduced.
Since the washer is made of an elastic material, if the object is inflated and contracted due to temperature fluctuation in a state where the object is fastened, the curvature of the washer changes correspondingly to absorb the expansion and contraction, and the fastening force fluctuates. Less stable fastening force can be maintained.
Further, if the first washer is press-fitted into the bolt and substantially integrated, the first washer and the bolt can be handled as one component, and convenience in use can be enhanced.
Furthermore, the washer can be reused.

The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view showing a first washer 3, a second washer 7, and a bolt 12 constituting an embodiment of a bolt locking structure according to the present invention.

  As shown in FIG. 2, the first washer 3 is an annular member provided with four claws 1 a protruding to the bottom surface side by cutting and raising, and a bolt insertion hole 2 having a shape other than a circle at the center. The cross-sectional shape before fastening is made of an elastic material such as spring steel that is curved in a bow shape. The four claws 1 a are provided at equal intervals in the circumferential direction of the washer 3. As shown in FIG. 3, the second washer 7 is also formed with four claws 4a protruding to the upper surface side by cutting and raising, and a circular bolt insertion hole 6 at the center.

  As shown in FIG. 1, the four claws 1a of the first washer can be engaged with the four claws 4a of the second washer. As shown in FIG. 4 (a), the four claws 1a of the first washer 3 can rotate in the tightening direction of the bolt 12 if the first washer 3 rotates together with the bolt 12. The rotation direction is the trailing wave direction, and the rotation of the bolt 12 in the loosening direction is inclined so as to be the opposite wave direction. On the other hand, if the four claws 4 a of the second washer 7 rotate relative to the first washer 3, the tightening direction of the bolt 12 in the relative relationship with the claws 1 a of the first washer 3. The rotation direction is a trailing wave direction, and the rotation of the bolt 12 in the loosening direction is inclined so as to be the opposite wave direction. As a result, the claw 1a of the first washer 3 and the claw 4a of the second washer 7 are both oriented in a direction that mechanically prevents the bolt 12 from loosening when they are engaged with each other. Therefore, loosening of the bolt can be prevented.

  The bolt insertion hole 2 provided in the first washer 3 is formed in a shape other than a perfect circle as shown in FIG. 2, and the bolt insertion hole 2 has a bolt as shown in FIG. A locking portion 8 having a shape other than a perfect circle provided integrally with the bottom surface of the head can be fitted. In the illustrated embodiment, the bolt insertion hole 2 of the first washer 3 is formed in a square shape, and the bolt locking portion 8 is formed in a square shape that matches the shape of the bolt insertion hole 2 of the first washer 3. The first washer 3 is formed in a size that matches the size of the bolt insertion hole 2.

  As shown in FIG. 3, the second washer 7 is an annular member having a substantially rectangular outer shape, four corners 5 and a circular bolt insertion hole 6 in the center. FIG. 3A shows the back surface of the second washer 7, that is, the contact surface to the object. By bending each corner 5 of the second washer 7 in FIG. 3A in the direction of the object, a protrusion 5a that can bite into the object 9 is formed as shown in FIG. The diameter of the bolt insertion hole 6 is larger than the outer diameter of the bolt 12, and the bolt 12 can rotate relative to the second washer 7. Thereby, when the bolt 12 is fastened to the object, the second washer 7 joined to the object 9 does not rotate together with the bolt, so that the fastening object is not damaged. Moreover, since the protrusion 5a of the second washer 7 can be configured by simple bending by pressing, the entire second washer 7 can be created by pressing a sheet metal, and the cost can be reduced.

  FIG. 3B shows the surface of the second washer 7, that is, the surface facing the first washer 3. As shown in FIG. 1, the claw 4 a of the second washer 7 is configured to engage with the claw 1 a of the first washer 3. As shown in FIG. 4B, the four claws 4a of the second washer 7 are in the follow-up direction with respect to the rotation of the bolt 12 in the tightening direction, and the rotation of the bolt 12 in the loosening direction. On the other hand, it is inclined in the opposite wave direction.

In FIG. 1, the thickness (L1) of the first washer 3 and the thickness (L) of the locking portion 8 formed integrally with the lower surface of the head of the bolt 12 have a relationship of L1> L. Is set to
The reason for providing the thickness difference due to this relationship is to prevent the locking portion 8 from interfering with the contact surface until the second washer 7 is in close contact with the contact surface of the object 9. Thereby, the first washer 3 can be bent and deformed until the second washer 7 comes into close contact with the contact surface. The second washer 7 may or may not be elastic, but preferably has elasticity.

  Since the present embodiment is configured as described above, when the first washer 3 and the second washer 7 are placed on the contact surface of the object 9, the bolt 12 is inserted and screwed into the female screw of the object 9 and tightened. The bolt 12 can be rotated together with the first washer 3 by matching the shape with the insertion hole 2 of the first washer 3. As the bolt 12 is tightened, the first washer 3 rotates, and its claw 1a hits the claw 4a of the second washer 7. The direction of inclination of the claw 1a, 4a is the follow-up direction with respect to this rotational direction. Therefore, the claw 1a of the first washer 3 gets over the claw 4a of the second washer 7, and can be easily tightened. The member to which the bolt 12 is screwed may be a nut. That is, a nut is screwed into a bolt 12 that penetrates the first washer 4, the second washer 7, and the object 9 and is tightened. Also in this case, the loosening prevention structure including the first washer 3, the second washer 7, and the bolt 12 functions effectively.

When the bolt 12 is tightened, the first washer 3 whose cross-sectional shape has been bowed before the fastening is pushed by the head of the bolt 12 and its lower surface is in close contact with the upper surface of the second washer 7. Deforms and deforms. The four protrusions 5a of the second washer 7 bite into the object 9 when the second washer 7 is pressed toward the object, and the second washer 7 does not rotate.
When pressure is applied to the first washer 3 due to the difference in thickness between the bolt insertion hole 2 of the first washer 3 and the locking portion 8 of the bolt 12, the first washer comes into close contact with the second washer 7. 3 and the second washer 7 generate a shape restoring force, and a force in the direction of pushing the head in the axial direction against the bolt 12 acts on the bolt 12. As a result, the frictional force increases on the threaded surface of the bolt 12 and the loosening is prevented. In addition, the first washer 3 is made of an elastic material, and the cross-sectional shape before fastening is curved in a bow shape. Thus, the curvature of the first washer 3 is changed to absorb the expansion and contraction, and a stable fastening force can be maintained with little fluctuation of the fastening force. Similarly, the second washer 7 is preferably an elastic body.

  When the bolt 12 tries to rotate in the direction of loosening the fastening force, the first washer 3 also tries to rotate integrally with the bolt 12. The four claws 1a of the first washer 3 engage with the four claws 4a of the second washer 7 in the opposite wave direction, that is, the reverse eye direction with respect to the rotation in the direction in which the bolt 12 is loosened. The four protrusions 5a of the second washer 7 bite into the object and become a great resistance to the rotation of the bolt 12, and the bolt 12 is prevented from loosening. Thus, according to the illustrated embodiment, the bolt 12 has a high locking effect, and the bolt 12 cannot be easily loosened.

  If the engagement between the claws 1a and 4a of the first and second washers 3 and 7 can be released, the bolt 12 can be rotated in the loosening direction to release the fastening of the object. Therefore, a kind of spacer is inserted between the first and second washers 3 and 7 to disengage both claws 1a and 4a, or the claws 1a and 4a can get over in the direction of the opposite wave. To. Thus, if the fastening of the object by the bolt 12 can be released, the bolt 12 can be easily extracted from the object 9, and the first washer 3 and the second washer 7 are substantially Since it is restored to the state before fastening, it can be reused.

  In the embodiment as described above, it is only necessary to provide the locking portion 8 on the bolt 12 side, and it is not necessary to perform special processing such as slit processing on the screw portion, so that the processing cost can be reduced. Further, it is possible to obtain the locking effect by using only the bolt 12 and the washers 3 and 7, and there is no need for another member for preventing the washer from rotating. In this respect, the number of parts is reduced and the cost is reduced. Can be reduced.

Note that the bolt locking structure according to the present invention is not limited to the structure of the above-described embodiment, and various modifications can be made, whereby another effect can be obtained. Hereinafter, modified examples will be described.
The first washer 3 may be press-fitted with the locking portion 8 of the bolt 12 in the insertion hole 2 so that the first washer 3 is integrated with the bolt. Since the first washer 3 needs to be made of an elastic material different from the material of the bolt, the bolt 12 and the first washer 3 integrated with each other cannot be integrally formed by press molding or the like. However, if both are press-fitted as described above, the first washer 3 can be integrated with the bolt 12 while having elasticity. With such an integrated structure, the bolt 12 and the first washer 3 can be handled as an integrated part at the fastening site of the object, and convenience is improved. That is, it is not necessary to align the shape of the locking portion 8 of the bolt with the shape of the insertion hole 2 of the first washer 3. Further, it is not necessary to manage the bolt 12 and the first washer 3 individually.

  The shape of the insertion hole 2 of the first washer 3 is not limited to a square shape as in the illustrated embodiment, and the insertion hole 2 of the first washer 3 and the locking portion 8 of the bolt are fitted together. Therefore, it may be a shape that does not relatively rotate in the circumferential direction, and therefore any shape other than a perfect circle. For example, the shape may be a rectangle, a polygon, a D shape, an ellipse, a key shape, or the like.

  The number of claws 1a and 4a formed on the first and second washers 3 and 7 is arbitrary, and may be in at least two places, that is, a plurality of places. The number of the protrusions 5a of the second washer 7 is also arbitrary and may be at a plurality of locations.

  FIG. 5 shows the four claws 1a of the first washer 3 in the embodiment of the present invention. The claw la is raised obliquely with respect to the surface of the first washer 3 by being cut and bent by a press (so-called “cutting over”). Similarly, the claw 4a of the second washer 7 can be manufactured by cutting and bending with a press.

It is a side view showing a washer and a bolt in an embodiment of a bolt locking structure according to the present invention. It is a bottom view of the 1st washer in the above-mentioned example. The 2nd washer in the said Example is shown, (a) is a bottom view, (b) is a top view. The washer in the said Example is shown, (a) is a 1st washer, (b) is a side view which shows a 2nd washer. It is a perspective view which shows the nail | claw of the 1st washer in the said Example.

Explanation of symbols

1a first washer claw 2 first washer insertion hole 3 first washer 4a second washer claw 5 second washer corner 5a second washer protrusion 6 second washer insertion Hole 7 Second washer 8 Locking portion 9 Object 12 Bolt L Thickness of first washer L1 Thickness of second washer

Claims (4)

A bolt locking structure having a bolt and a washer through which the bolt is inserted,
The washer includes a plurality of claws in the direction of the object, and includes a first washer including an insertion hole having a shape other than a perfect circle formed as a bolt insertion portion,
A plurality of claws are provided in the head direction of the bolt, and these claws engage with the claws of the first washer to form a pair with the first washer and are provided with a plurality of protrusions for fixing to the object. And a second washer
The claws of the first washer and the claws of the second washer are in a follow-up direction with respect to rotation of the bolt in the tightening direction, and are opposed to rotation of the bolt in the loosening direction. Tilt in the direction,
The bolt is provided with a locking portion having a shape that can be fitted into the insertion hole of the first washer on the bottom surface of the head.   The relationship of L1> L is set between the thickness (L1) of the first washer and the thickness (L) of the locking portion on the bolt side that can be fitted to the insertion portion of the washer. The described bolt locking structure.   The bolt locking prevention structure according to claim 1, wherein the first washer is integrated with the bolt by press-fitting a locking portion of the bolt into the insertion hole.   2. The bolt locking structure according to claim 1, wherein at least one of the first washer and the second washer is made of a sheet metal having an elastic cross-sectional shape before being fastened in a bow shape.

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