JP2009180289A - Bolt retaining structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable bolt retaining structure capable of locking a bolt with a simple operation. <P>SOLUTION: The bolt retaining structure includes hexagon head bolts 9, a flange section 3a of a differential case 3 which the shanks 9b of the hexagon head bolts penetrate and with which the heads 9a of the bolts are engaged and a ring gear 2 fixed to the flange section 3a of the differential case 3 by the hexagon head bolts 9. Recessed parts 3d into which the heads 9a of the hexagon head bolts 9 are sunk are formed in the flange section 3a of the differential case 3, and a resin 21 is filled in between the recessed part 3d and the head 9a of the hexagon head bolt sunk into the recessed part 3d. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bolt detent structure.

  For example, bolts used in places where variable loads and vibrations are easily applied, and places where they are easily affected by temperature changes, such as bolts used in vehicles such as automobiles, are provided with anti-rotation measures. The Conventionally, various methods have been proposed as a countermeasure against the rotation of the bolt. For example, as a method of mechanically fixing a bolt, a method of fixing the rotation of the bolt with a bent washer (for example, a washer with a tongue), a pin or the like is well known. Other well-known methods include mounting a washer with a strong spring force (spring washer) between the head of the bolt and the seating surface, or applying a locking agent to the screw thread of the bolt and fastening it after tightening. .

  For example, a bolt (for example, refer to Patent Document 1) used to fasten a ring gear to a differential case (hereinafter referred to as “difference case”) of an automobile is easily subjected to variable load and vibration, so that the bolt is loosened. A bent washer or the like is used as a preventive measure against dropping. In particular, the bolts that fasten the differential case and the ring gear are mounted on the circumference around the rotation axis of the differential case and the ring gear, so the amount of slip that occurs between the bolt head and its seating surface is closer to the outer diameter side. growing. If the difference in the amount of slip coincides with the rotational direction in which the bolt is loosened, the bolt tightening force gradually decreases, which may lead to loosening and dropping of the bolt. Therefore, also in this case, it is necessary to take a countermeasure against the rotation of the bolt.

In Patent Documents 2 to 6, the height adjustment bolt screwed into the floor panel is used as a detent measure for the height adjustment bolt (headless bolt) used in the floor panel support device in the building field. A technique is disclosed in which a height adjustment bolt is prevented from rotating by filling a resin in a gap between an upper end portion and a floor panel and curing the resin.
Japanese Patent Laying-Open No. 2005-42841 (FIG. 1, reference numeral 21) Japanese Utility Model Publication No. 5-66141 Japanese Patent Laid-Open No. 7-224516 JP 2005-299218 A JP 2003-129644 A JP 9-41634 A

  However, the method of fixing the rotation of the bolt with a bent washer, a pin or the like has a problem in that it requires a relatively large number of work steps. In addition, the method of applying the locking agent to the screw thread of the bolt and fixing it after tightening has a problem in terms of the reliability of the locking agent.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a bolt detent structure that can perform bolt locking with a simple operation and has high reliability.

  As means for solving the above-described problems, the bolt rotation prevention structure of the present invention is configured as follows. That is, the bolt detent structure according to the present invention includes a headed bolt, a first fastened object in which a shaft portion of the headed bolt is penetrated and the head of the bolt is engaged, and the headed bolt. And a second fastened object fastened to the first fastened object by a bolt. The first article to be fastened is formed with a recessed portion for immersing a part or all of the head of the headed bolt, and the head of the headed bolt inserted into the recessed portion and the recessed portion. Resin is filled between some or all.

  According to such a configuration, the head of the headed bolt is engaged with the inside of the resin, and the outside of the resin is engaged with the recessed portion, so that the head of the headed bolt is against the first object to be fastened. This prevents the head bolt from loosening and falling off. In addition, since the resin functions as a detent by engaging both the headed bolt and the depressed portion, the reliability as a detent is higher than the method of applying a locking agent to the screw thread of the bolt. In addition, after tightening the head bolt, there is an advantage that the bolt can be prevented from being rotated by a simple operation of filling the depressed portion with a fluid resin and curing the resin.

  Moreover, the rotation prevention structure of the volt | bolt of this invention may be comprised as follows. That is, in the bolt rotation prevention structure of the present invention, in the above-described configuration, the depressed portion has a removal prevention shape that prevents the resin from being removed from the head of the headed bolt in the axial direction of the bolt. It has become.

  For example, the said depression part shall have the side surface which mutually opposes, and those side surfaces incline so that it may mutually approach toward a shallow position from a deep position, and form the said removal prevention shape. Can do.

  According to this configuration, even when the resin is difficult to engage with the head of the headed bolt in the axial direction of the bolt, the resin can move in the axial direction of the headed bolt and be removed from the head. Is prevented. Thereby, the reliability as a detent of a bolt improves.

  The first fastened object is, for example, a differential case included in the vehicle, and the second fastened object is, for example, a ring gear fastened to the differential case by the headed bolt.

  According to the bolt detent structure according to the present invention, the head of the headed bolt is engaged with the inner side of the resin, and the outer side of the resin is engaged with the recessed portion. Therefore, it is possible to prevent the headed bolt from loosening and falling off.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a differential 1 (differential device) of a rear wheel drive type automobile to which a bolt detent structure according to the present invention is applied.

  The differential 1 mainly includes a ring gear 2, a differential case 3 (hereinafter referred to as “differential case 3”), a pair of pinion gears 4 and 5, a pair of side gears 6 and 7, and the like.

  In the differential 1, a bevel gear is used as the ring gear 2. The ring gear 2 is fastened to a flange portion 3 a formed on the outer periphery of the differential case 3 by a plurality of hexagon bolts 9 arranged at appropriate intervals in the rotational circumferential direction. The ring gear 2 is meshed with a drive pinion 10a at the end of the input shaft 10 connected to a propeller shaft (not shown). The input shaft 10 is rotatably supported via rolling bearings 12 and 12 in a differential carrier (not shown).

  The differential case 3 houses a pair of pinion gears 4 and 5 and a pair of side gears 6 and 7 inside thereof. The pair of pinion gears 4 is rotatably supported in the differential case 3 via a pinion shaft 15 extending in parallel with the radial direction of the ring gear 2. The pair of side gears 6 and 7 are rotatably supported on the inner diameter side of the boss portions 3 b and 3 b of the differential case 3 so as to have the same rotation axis as that of the ring gear 2. Each pinion gear 4, 5 is meshed with both side gears 6, 7. The differential case 3 is rotatably supported in a differential carrier (not shown) via rolling bearings 14 and 14.

  Splines 6a and 7a are formed in the inner diameter fitting portions of the side gears 6 and 7, and the inner ends of the drive shafts 20 and 20 are spline-fitted thereto.

  Next, the bolt detent structure according to the present invention will be described in detail. The bolt detent structure according to the present invention includes a hexagonal bolt 9, a differential case 3 (first fastened object) fastened by the hexagonal bolt 9, and a ring gear 2 (second fastened object).

  The hexagon bolt 9 is cited as an example of a headed bolt. Here, the headed bolt may have any head 9a that can be fixed in a non-rotatable manner by a cured resin 21 described later. Therefore, the head portion 9a is not limited to a hexagonal column, and may be, for example, a triangular column, a quadrangular column, an elliptical column, or the like.

  The flange portion 3a of the differential case 3 is formed with a plurality of through holes 3c at appropriate intervals on the circumference centered on the rotation axis. The shaft portions of the hexagon bolts 9 are respectively formed in the through holes 3c. 9b is penetrated, and the head portion 9a of the bolt 9 is engaged with the flange portion 3a in the axial direction. The male screw portion 9c of the shaft portion 9b of the hexagon bolt 9 is screwed into the female screw portion formed on the ring gear 2, and the hexagon bolt 9 is tightened with an appropriate torque.

  As shown in FIG. 3 which is an AA cross-sectional view of FIGS. 2 and 2, the flange portion 3 a of the differential case 3 is formed with a recessed portion 3 d into which the entire head portion 9 a of the hexagon bolt 9 is recessed. A resin 21 is filled and hardened between the depressed portion 3d and the head portion 9a of the hexagonal bolt 9 immersed therein. It is desirable that the resin 21 is filled without any gaps.

  For example, as shown in FIG. 2 and FIG. 3, the depressed portion 3 d includes opposite side surfaces 3 dA and 3 dA that extend in the radial direction of the differential case 3, a depressed bottom surface 3 dB that is also a seating surface of the head 9 a of the hexagon bolt 9, The inner diameter side surface 3dC, which is the side surface, is formed. The depressed portion 3d has a removal prevention shape that prevents the cured resin 21 from being removed from the head portion 9a of the hexagon bolt 9 in the axial direction of the bolt. The shape for preventing the recess 3d from coming off is formed by inclining both side surfaces 3dA and 3dA so as to approach each other from the deep position of the recess 3d toward the shallow position. Although the outer diameter side of the depressed portion 3d is open, even if the cured resin 21 tries to move to the outer diameter side of the differential case 3 (in the direction of arrow S in FIG. 2), the resin 21 Since it is latched by the head 9a, it does not pull out to the outer diameter side.

  Filling the depressed portion 3d with the resin 21 is performed, for example, by the following procedure. First, the ring gear 2 is disposed so as to overlap the flange portion 3a of the differential case 3 with the rotation axis aligned. At this time, the positions of the through hole 3c of the flange portion 3a of the differential case 3 and the female screw portion 2a of the ring gear 2 are also matched.

  Next, the hexagon bolt 9 is inserted into the through hole 3c of the flange portion 3a of the differential case 3, the male screw portion 9c of the hexagon bolt 9 is screwed into the female screw portion 2a of the ring gear 2, and tightened with an appropriate torque. The head 9a is immersed in the depression 3d.

  Then, a fluid resin is poured between the depressed portion 3d and the head 9a of the hexagon bolt 9 to cure the resin. The cured resin 21 forms a concave shape corresponding to the head portion 9a of the hexagon bolt 9 on the inner side, engages with the head portion 9a, and forms a shape corresponding to the shape of the recessed portion 3d on the outer side, Engages with side surfaces 3dA, 3dA, 3dC. As a result, the cured resin 21 functions as a detent for the hexagon bolt 9.

  The shape of the side portion (side surface) of the depressed portion 3d is not limited to the shape constituted by the side surfaces 3dA, 3dA, and 3dB as long as the cured resin 21 is engaged in the rotation direction of the hexagon bolt 9. .

  Further, as long as the cured resin functions as a detent for the hexagon bolt 9, the entire head portion 9a of the hexagon bolt 9 does not have to be recessed into the recessed portion 3d, and a part of the head portion 9a enters the recessed portion 3d. It may be a detent structure of an immersed bolt.

  Various resins can be used as the resin 21 filled between the head portion 9a of the hexagon bolt 9 and the depressed portion 3d. For example, an epoxy-based thermosetting resin excellent in heat resistance can be used. It is desirable to use a resin. Moreover, if a putty-like two-component mixed type is used, the above filling operation is easy to perform.

  Hereinafter, the operation of the above-described differential 1 will be described. Since the differential 1 is well-known except for the bolt detent structure, the operation of the differential itself will only be outlined.

  First, when the vehicle travels straight, rotational power is input to the input shaft 10. This rotational power is transmitted to the differential case 3 via the meshing portion between the drive pinion 10a and the ring gear 2, and the differential case 3 rotates. When the differential case 3 rotates, the pair of pinion gears 4 and 5 revolve, and the pair of side gears 6 and 7 engaged therewith are driven to rotate. As a result, the left and right drive shafts and the left and right rear wheels are driven at the same rotational speed.

  On the other hand, when the vehicle is traveling in a curve, a difference in rotational resistance occurs between the left and right rear wheels, so that the pair of pinion gears 4 and 5 rotate while revolving and mesh with the pair of side gears 6 and 6. 7 rotates differentially. As a result, rotational power having different rotational speeds is distributed to the left and right drive shafts and the left and right rear wheels.

  When the rotational power is transmitted from the input shaft 10 to the left and right rear wheels, the rotational power is transmitted to the ring gear 2 from the drive pinion 10a. Since the ring gear 2 and the flange portion 3 a of the differential case 3 are fastened by the hexagon bolt 9, basically, the rotational power of the ring gear 2 is caused by the frictional force between the ring gear 2 and the flange portion 3 a of the differential case 3. Although transmitted to the side, a part of the rotational power of the ring gear 2 acts as a shearing force on the shaft portion 9 b of the hexagon bolt 9. When the ring gear 2 slips relative to the flange portion 3a of the differential case 3 in the rotational direction, for example, when the ring gear 2 and the differential case 3 rotate in the arrow Z direction as shown in FIG. When the above slip occurs, the slip amount of the head portion 9a of the hexagon bolt 9 with respect to the depressed bottom surface 3dB (seat surface) of the differential case 3 rotates more than the slip amount on the rotation center side (indicated by the length of the arrow X). The amount of slip on the centrifugal side (indicated by the length of arrow Y) is greater. For this reason, a counterclockwise force is applied to the head portion 9a of the hexagon bolt 9, and the hexagon bolt 9 is loosened if the resin 21 is not filled. However, the head portion 9a of the hexagon bolt 9 is engaged with the inside of the cured resin 21, and the outer side of the resin 21 is engaged with the side surfaces 3dA, 3dA, 3dB of the depressed portion 3d. 9a does not rotate with respect to the flange portion 3a of the differential case 3, and the hexagon bolt 9 is reliably prevented from loosening and dropping off.

  Further, the resin 21 does not engage with the head 9a of the hexagon bolt 9 in the axial direction of the bolt 9, but since the recessed portion 3d has the above-described removal prevention shape, the resin 21 is the hexagon bolt. 9 is not removed from the head 9 a of the hexagon bolt 9 by moving in the axial direction of 9.

[Second Embodiment]
Hereinafter, a second embodiment of the present invention will be described. FIG. 4 and FIG. 5 are diagrams showing an embodiment in which the bolt detent structure according to the present invention is applied to a differential (differential device) of a front-wheel drive type automobile. In addition, the same code | symbol is attached | subjected about the structure similar to what was demonstrated in 1st Embodiment, and the description is abbreviate | omitted.

  The differential 1A is also mainly composed of a ring gear 2A, a differential case 3, a pair of pinion gears 4, 5, a pair of side gears 6, 7, and the like.

  In the differential 1A, a gear (for example, a helical gear) whose tooth tips extend in the centrifugal direction is used as the ring gear 2A. The ring gear 2A is fastened to a flange portion 3a formed on the outer periphery of the differential case 3 by a plurality of hexagon bolts 9 arranged at appropriate intervals in the rotational circumferential direction. The ring gear 2 is meshed with the final drive gear 13.

  Also in the present embodiment, the bolt detent structure according to the present invention includes the hexagon bolt 9, the differential case 3 (first fastened object) fastened by the hexagon bolt 9, and the ring gear 2 (second fastened object). ).

  A plurality of through holes 3c are also formed on the flange portion 3a on the outer periphery of the differential case 3 at appropriate intervals on the circumference centered on the rotation axis, and hexagon bolts 9 are respectively formed in the through holes 3c. The shaft portion 9b is penetrated, and the head portion 9a of the bolt 9 is engaged with the flange portion 3a in the axial direction. The male screw portion 9c of the shaft portion 9b of the hexagon bolt 9 is screwed into the female screw portion 2Aa formed on the ring gear 2, and the hexagon bolt 9 is tightened with an appropriate torque.

  As shown in FIG. 5, the flange portion 3 a of the differential case 3 is also formed with a depressed portion 3 d into which the entire head portion 9 a of the hexagon bolt 9 is recessed. Resin 21 is filled between the depressed portion 3d and the head portion 9a of the hexagon bolt 9 immersed therein.

  In the present embodiment as well, as in the first embodiment, the shape of the recess 3d is prevented from coming off so that both side surfaces 3dA and 3dA approach each other from the deep position of the recess 3d toward the shallow position. It is constituted by doing. In addition, as long as the cured resin 21 functions as a detent for the hexagon bolt 9, it is not necessary that the entire head portion 9 a of the hexagon bolt 9 is immersed in the depressed portion 3 d, and a part of the head portion 9 a is partially depressed. It may be a detent structure of the bolt that has been immersed.

  In addition, since the effect | action of the rotation prevention structure of the volt | bolt in this Embodiment is the same as that of 1st Embodiment, description is abbreviate | omitted.

  The present invention can be applied to an object in which two objects to be fastened are fastened by a head bolt.

It is a figure which shows the rear wheel drive type differential (differential device) etc. to which the detent | locking structure of the volt | bolt which concerns on this invention was applied. It is the perspective view which showed the differential case and ring gear to which the rotation prevention structure of the volt | bolt which concerns on this invention was applied. It is AA sectional drawing of FIG. It is a figure which shows the front wheel type differential (differential device) etc. to which the detent | locking structure of the volt | bolt which concerns on this invention was applied. It is BB sectional drawing of FIG.

Explanation of symbols

2 Ring gear (second object to be fastened)
3 Differential case, differential case (first fastened object)
3d depression 3dA side of depression 9 Hex bolt (head bolt)
9a Hex head head (head bolt head)
9b Shaft of hexagon bolt (shaft of head bolt)
21 resin

Claims (4)

A head bolt,
A first fastened object in which a shaft portion of the headed bolt is penetrated and a head portion of the bolt is engaged;
A second fastened object fastened to the first fastened object by the headed bolt;
A bolt detent structure comprising:
The first object to be fastened is formed with a depressed portion for immersing a part or all of the head of the head bolt.
A bolt rotation-preventing structure, wherein a resin is filled between the depressed portion and a part or all of a head of a headed bolt immersed in the depressed portion. In the bolt detent structure according to claim 1,
A bolt rotation-preventing structure, wherein the recessed portion has a removal prevention shape that prevents the resin from being removed from the head of the headed bolt in the axial direction of the bolt. In the bolt detent structure according to claim 2,
The depressed portion has opposite side surfaces, and the removal prevention shape is formed by tilting the side surfaces so as to approach each other from a deep position toward a shallow position. Bolt detent structure as a feature. In the bolt detent structure according to any one of claims 1 to 3,
The first fastened object is a differential case provided in the vehicle,
The second fastened object is a ring gear structure that is a ring gear fastened to the differential case by the headed bolt.

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