JP2012017767A - Shaft holding structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shaft holding structure that prevents a shaft below a vehicle body from falling in spite of shaft breakage and lowers a shaft position and a floor without increasing weight of the vehicle.SOLUTION: There is provided the shaft holding structure 31 for holding the shaft 10 including rotatable first and second shafts 12, 15 and a joint 14 having an outer member 21 and an inner member 23 when the shaft is broken. The shaft holding structure includes: a locking member 24 fixed to the outer member 21, which has a flange part 24c for surrounding the first shaft 12; a stopper member 25 fixed to the first shaft 12 positioned between the inner member 23 and the flange part 24c, which has an outer diameter larger than the inner diameter of the flange part 24c; and a reduced diameter part 12e formed on the first shaft 12 positioned between the stopper member 25 and the inner member 23, which has the smallest diameter of the first shaft 12 and the second shaft 15.

Description

  The present invention relates to a shaft holding structure mounted on a vehicle, and more particularly to a shaft holding structure for holding a broken shaft when a propeller shaft or a drive shaft is broken.

  Generally, in a vehicle such as an automobile, a shaft for transmitting a large driving force such as a propeller shaft or a drive shaft is provided at the lower part of the vehicle body. Although these shafts are designed with sufficient strength, the shafts were broken due to unforeseen circumstances, such as excessively large torque acting on the shafts for some reason or excessive bending force. In some cases, a shaft holding structure may be provided to prevent the broken shaft from interfering with other parts or falling off the road surface.

  Conventionally, as this type of shaft holding structure, a structure in which a guard is provided below the propeller shaft is known (see, for example, Patent Document 1). In this conventional shaft holding structure, for example, a U-shaped guard provided from the lower side of the propeller shaft or a ring-shaped guard provided so as to surround the periphery of the propeller shaft is fixed to the vehicle frame. Configured.

  By having such a configuration, the shaft holding structure described in Patent Document 1 supports the propeller shaft by a guard from below when the propeller shaft is broken, so that the propeller shaft is prevented from falling off. It was.

Japanese Utility Model Publication No. 49-148624

  However, in the conventional shaft holding structure as described above, since the guard is provided below the propeller shaft, it is necessary to secure a mounting space for providing the guard at the lower part of the vehicle body, and the guard. To prevent the ground from interfering with the ground, it is necessary to secure the minimum ground clearance below the guard, and the height of the propeller shaft is increased by the amount of the guard, which hinders the floor from being lowered. There was a problem.

  In order to solve such a problem, it has been considered to further increase the strength of the shaft without providing such a guard to reduce the possibility of the shaft breaking. However, in that case, the shaft diameter must be made larger than usual, and the shaft weight becomes heavier than necessary. Therefore, an increase in the weight is suppressed, and some kind of shaft holding structure is provided in case of shaft breakage. It was hoped that.

  The present invention has been made to solve the above-described conventional problems, and can prevent the shaft that transmits the driving force provided at the lower portion of the vehicle body from falling off even if it is broken, and can reduce the weight of the vehicle. An object of the present invention is to provide a shaft holding structure capable of lowering the position of the shaft and lowering the floor without reducing the height.

  In order to achieve the above object, the shaft holding structure according to the present invention includes (1) a rotatable first shaft, a rotatable second shaft, and the first shaft and the second shaft. A joint having an outer member fixed to the second shaft and integrally rotated, and an inner member fixed to the first shaft and integrally rotated together with the outer member; In a shaft holding structure for holding an integrally rotating shaft when broken, a locking member fixed to the outer member and having a flange portion surrounding the first shaft, and the inner member And is fixed to the first shaft positioned between the flange portion of the locking member and has an outer diameter larger than the minimum inner diameter of the flange portion. A topper member; and a reduced diameter portion formed on the first shaft located between the stopper member and the inner member and having the smallest diameter in the first shaft and the second shaft. Features.

With this configuration, during normal rotation of the shaft, the rotation of the first shaft is transmitted from the inner member to the second shaft through the outer member. As a result, the first shaft and the second shaft are integrally rotated via the joint. When an extremely excessive external force is applied to the shaft for some reason, the reduced diameter portion that is thinner and weaker than other portions of the shaft is broken. Since the reduced diameter portion is formed in the first shaft positioned between the stopper member and the inner member, the first shaft is likely to fall out of the joint when the first shaft is detached from the inner member. At this time, the stopper member of the first shaft is caught by the flange portion of the locking member fixed to the outer member, and the first shaft is prevented from falling off from the joint.
In addition, even when the shaft is broken, the first shaft is prevented from falling off the joint, so there is no need to increase the strength of the shaft to prevent the shaft from being broken as in the prior art. An increase in weight is avoided. Furthermore, since it is not necessary to provide a guard below the shaft as in the prior art, the mounting position of the shaft is lowered as compared with the case where a guard is provided, and the floor is lowered.

  ADVANTAGE OF THE INVENTION According to this invention, while the shaft which transmits the driving force provided in the lower part of the vehicle body should be broken, it can be prevented from falling off, and the shaft can be lowered and the floor can be lowered without increasing the weight of the vehicle. The floor can be lowered.

It is a side view of the propeller shaft concerning an embodiment of the invention. It is a figure which shows the joint which concerns on embodiment of this invention, (a) is a center longitudinal cross-sectional side view, (b) is sectional drawing cut | disconnected by the II-II line which abbreviate | omitted the dust cover in (a). . It is a disassembled perspective view of the joint which concerns on embodiment of this invention. It is a side view which shows the assembly procedure of the propeller shaft which concerns on embodiment of this invention, (a) is the state before an assembly, (b) is the state which assembled | attached the inner member to the front propeller shaft, (c) is the front propeller. The state which connected the shaft and the rear propeller shaft is each shown. It is a side view which shows the propeller shaft which concerns on embodiment of this invention, (a) shows the state which the propeller shaft expanded, (b) shows the state which the propeller shaft broke, respectively. It is an enlarged side view which shows the rear part of the front propeller shaft which concerns on embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the example which applied the holding structure of the shaft of this invention to the propeller shaft 10 of the motor vehicle is shown.

First, the configuration of the propeller shaft 10 will be described.
The propeller shaft 10 is provided in the lower part of the vehicle. This vehicle is composed of a large automobile, an ordinary automobile, and the like, and is composed of, for example, an ordinary automobile equipped with a laterally mounted four-cylinder gasoline engine.

  As shown in FIG. 1, the propeller shaft 10 includes a front side joint 11, a front propeller shaft 12 as a first shaft connected to the front side joint 11, and a front propeller shaft 12 that is rotatably and elastically supported. A center bearing 13, a joint 14 connected to the front propeller shaft 12, a rear propeller shaft 15 as a second shaft connected to the joint 14, and a rear side joint 16 connected to the rear propeller shaft 15. It is configured to include.

  The propeller shaft 10 connects the transfer and the rear differential mechanism, and transmits the rotation of the transfer to the rear differential mechanism at a constant speed. The front side joint 11 connects the front propeller shaft 12 and the transfer, and the rear side joint 16 connects the rear propeller shaft 15 and the rear differential mechanism. Since the entire configuration of the propeller shaft 10 is substantially the same as that of the conventional propeller shaft, the joint 14 will be described in detail here.

  As shown in FIGS. 2 to 4, the joint 14 is a tripod type constant velocity joint, and includes an outer member 21 fixed to the rear propeller shaft 15 and an inner side fixed to the front propeller shaft 12 with three rollers 22. It includes a member 23, a locking member 24 fixed to the outer member 21, a stopper member 25 fixed to the front propeller shaft 12, and a dust cover 26 fixed to the front propeller shaft 12 and the outer member 21. Has been.

  The outer member 21 is formed at the front end of the rear propeller shaft 15. The outer member 21 has a bottomed cylindrical shape, and includes a cup portion 21a, a roller guide portion 21b and a ridge portion 21c formed on the inner peripheral side, and a locking member attachment formed on the front end portion on the inner peripheral side. A groove 21d and a dust cover engaging groove 21e formed at the front end portion on the outer peripheral side are provided.

  The cup part 21a has an opening end part 21f. Further, the cup portion 21 a is formed so that the axis of the cup portion 21 a coincides with the axis of the rear propeller shaft 15.

  The roller guide portions 21b are formed at three locations, and are provided on the inner peripheral side of the cup portion 21a so as to extend in the axial direction at equal intervals in the circumferential direction (here, 120 ° intervals). A roller 22 is fitted to the roller guide portion 21b so as to be slidable and rotatable, and is guided so as to be rotatable in a direction parallel to the axis of the outer member 21.

  Further, the protrusions 21c are provided at three positions between the three roller guide portions 21b, protrude from the inner peripheral side of the outer member 21 inward in the radial direction, and are formed along the roller guide portions 21b. Has been. The ridges 21c support the rollers 22 so as to slide reliably along the roller guides 21b.

  The dust cover engaging groove 21e is formed in the vicinity of the opening end 21f on the outer peripheral side of the outer member 21. The dust cover engaging groove 21e is engaged with an engaging portion 26b of the large outer diameter portion 26a of the dust cover 26.

  The inner member 23 includes a roller 22, a spider 27 that holds the roller 22 and is fixed to the front propeller shaft 12, and a snap ring 28 that fixes the spider 27. The inner member 23 is fixed to the front propeller shaft 12 and is inserted into the outer member 21. Further, the inner member 23 is connected to the outer member 21 so as to be movable in the axial direction of the outer member 21 and to be swingable within a predetermined angle range. Thereby, even if the axial center of the inner member 23 and the front propeller shaft 12 is inclined relative to the axial center of the outer member 21, the rotation of the front propeller shaft 12 and the inner member 23 is applied to the outer member 21 at a constant speed. It is to be transmitted.

  The spider 27 includes an annular spider body 27a and three roller support shafts 27b. The spider body 27a includes a spherical outer peripheral portion 27c and spline internal teeth 27d formed so as to penetrate in the axial direction. The roller support shaft 27b has a cylindrical shape, protrudes radially outward from the outer peripheral portion 27c, and is integrally formed with the spider body 27a at equal intervals in the circumferential direction (here, at intervals of 120 degrees). These roller support shafts 27b support the roller 22 in a rotatable manner.

  Each roller 22 is attached to a needle bearing 29 supported by a roller support shaft 27b, and is provided to smoothly rotate around the roller support shaft 27b. Each roller 22 is fixed to the roller support shaft 27b by a roller snap ring 30 so as not to fall off.

  The front propeller shaft 12 includes a spline external tooth 12a formed at the rear end portion, a stopper member engagement groove 12b formed slightly on the front side thereof, and dust formed on the front side of the stopper member engagement groove 12b. A cover engagement groove 12c, a snap ring engagement groove 12d formed adjacent to the rear side of the spline outer teeth 12a, and a reduced diameter portion 12e formed adjacent to the front side of the spline outer teeth 12a. ing. The spline outer teeth 12 a are engaged with the spline inner teeth 27 d of the spider 27 so that the front propeller shaft 12 is connected to the spider 27. A snap ring 28 is attached to the snap ring engaging groove 12d to prevent the front propeller shaft 12 from coming out of the spider 27, and the spider 27 is positioned with respect to the front propeller shaft 12. . Further, the engagement portion 26d of the small outer diameter portion 26c of the dust cover 26 is engaged with the dust cover engagement groove 12c.

  As shown in an enlarged view in FIG. 6, the reduced diameter portion 12 e is formed of a short shaft-shaped portion having the smallest diameter in the propeller shaft 10 formed adjacent to the front side of the spline external teeth 12 a of the front propeller shaft 12. The rigidity of the reduced diameter portion 12e is the smallest among the propeller shafts 10 although a sufficient size as the propeller shaft 10 is secured. That is, the diameter D1 of the reduced diameter portion 12e is smaller than, for example, the shaft diameter D2 of the rear portion of the front propeller shaft 12 or the groove diameter D3 of the stopper member engaging groove 12b. For this reason, when an extremely excessive external force is applied to the propeller shaft 10, the reduced diameter portion 12e is broken.

  The locking member 24 includes a flat annular part 24a, a notch part 24b formed in a part of the annular part 24a, and protrudes from the annular part 24a toward the center in the radial direction and is equally spaced in the circumferential direction. And three flange portions 24c provided at intervals of 120 degrees here. The annular portion 24 a is fitted in the locking member mounting groove 21 d of the outer member 21. Each flange portion 24 c surrounds the front propeller shaft 12, and each tip thereof is provided immediately without contacting the front propeller shaft 12, and the minimum diameter formed by these tip portions is smaller than the outer diameter of the stopper member 25. It is made small (refer FIG.2 (b)). That is, the stopper member 25 cannot escape between the flange portions 24c and jump forward. The flange portion 24 c has a step shape that protrudes forward with respect to the outer member 21.

  Further, as shown in FIG. 2B, the locking member 24 is mounted so that the flange portion 24c matches the position of the protrusion 21c of the cup portion 21a when viewed from the front side. Thereby, since the roller guide part 21b is located in the space between flange parts 24c, it is prevented that the roller 22 interferes with the flange part 24c (refer Fig.5 (a)).

  As shown in FIG. 3, the stopper member 25 has an annular main body 25 a and a joint portion 25 b in which a part thereof is cut out. The mating portion 25b is expanded and attached to the stopper member engaging groove 12b of the front propeller shaft 12. That is, the stopper member 25 is fixed between the spider 27 fixed to the front propeller shaft 12 and the flange portion 24 c of the locking member 24. As described above, the stopper member 25 has an outer diameter larger than the minimum inner diameter of the flange portion 24c.

  Here, the shaft holding structure according to the present invention includes the locking member 24, the stopper member 25, and the reduced diameter portion 12e of the front propeller shaft 12 described above. When the shaft holding structure 31 causes an excessively large external force to act on the propeller shaft 10 and the reduced diameter portion 12e breaks, the stopper member 25 is caught on the flange portion 24c of the locking member 24, and the front propeller shaft 12 is connected to the joint. 14 is prevented from falling off.

  As shown in FIGS. 2 and 3, the dust cover 26 is made of an elastic material such as rubber, is formed to be stretchable, and has a convex shape formed on the inner peripheral surface of the large outer diameter portion 26a. The joint part 26b and the convex-shaped engaging part 26d formed in the internal peripheral surface of the small outer diameter part 26c are provided. The engaging portion 26b of the large outer diameter portion 26a is engaged with the dust cover engaging groove 21e of the outer member 21, and the engaging portion 26d of the small outer diameter portion 26c is engaged with the dust cover engaging groove 12c of the front propeller shaft 12. It is designed to engage. As shown in FIG. 2A, the engaging portions 26b and 26d of the dust cover 26 are fastened by fixing bands 34 and 35 from the outer peripheral side. The dust cover 26 is filled with lubricating oil such as grease that lubricates the outer member 21 and the inner member 23.

  As shown in FIG. 3, the snap ring 28 has an annular main body 28 a and a joint portion 28 b in which a part thereof is cut out. The mating portion 28b is expanded and attached to the snap ring engaging groove 12d of the front propeller shaft 12, and the spider 27 is positioned so as to prevent the spider 27 from coming out of the front propeller shaft 12 as described above.

  Next, a procedure for assembling the joint 14 of the propeller shaft 10 will be described.

  First, the engaging portion 26 d of the small outer diameter portion 26 c of the dust cover 26 is attached to the dust cover engaging groove 12 c of the front propeller shaft 12. Hereinafter, in FIG. 4 and FIG. 5, the display of the dust cover 26 is omitted. As shown in FIG. 4A, the stopper member 25 is fitted from the rear end portion of the front propeller shaft 12 and mounted in the stopper member engaging groove 12b. On the other hand, the needle bearing 29 and the roller 22 are attached to each roller support shaft 27 b of the spider 27 to form the inner member 23. Then, the inner member 23 is fitted from the rear end portion of the front propeller shaft 12, and the spline inner teeth 27 d of the spider 27 are engaged with the spline outer teeth 12 a of the front propeller shaft 12 and press-fitted.

  Then, as shown in FIG. 4B, the snap ring 28 is fitted from the rear end portion of the front propeller shaft 12 and mounted in the snap ring engaging groove 12d. Thereby, the inner member 23 is completely fixed to the front propeller shaft 12 without being displaced in the axial direction.

  As shown in FIG. 4C, the rear end portion of the front propeller shaft 12 to which the inner member 23 is attached is inserted into the cup portion 21 a of the outer member 21. When inserting, each roller 22 is guided to the roller guide portion 21b. After the insertion, the roller 22 is slidably supported by the roller guide portion 21b, so that the inner member 23 can move in the axial direction of the outer member 21 and can swing within a predetermined angular range. The outer member 21 is connected. Even if the axis of the inner member 23 and the front propeller shaft 12 is inclined relative to the axis of the outer member 21 and the rear propeller shaft 15, the rotation of the front propeller shaft 12 and the inner member 23 is constant. It is transmitted to the outer member 21 and the rear propeller shaft 15.

  Thereafter, the notch 24b of the locking member 24 is pushed out and fitted to the front propeller shaft 12 from the side. Then, the notched portion 24b of the locking member 24 is pressed and contracted to reduce the diameter of the annular portion 24a, inserted into the inner peripheral side of the cup portion 21a of the outer member 21, and fitted into the locking member mounting groove 21d of the outer member 21. Fit together. Then, the engaging portion 26 b of the large outer diameter portion 26 a of the dust cover 26 is engaged with the dust cover engaging groove 21 e of the outer member 21.

  Next, the operation of the joint 14 of the propeller shaft 10 and the shaft holding structure 31 will be described.

  When the propeller shaft 10 rotates, the driving force of the front propeller shaft 12 is transmitted from the roller guide portion 21 b of the outer member 21 to the rear propeller shaft 15 via the spider 27 and the roller 22 that are the inner members 23. Thereby, the front propeller shaft 12 and the rear propeller shaft 15 are integrally rotated. At this time, when a force in the expansion / contraction direction or the bending direction acts between the front propeller shaft 12 and the rear propeller shaft 15, the roller 22 is guided by the roller guide portion 21b and appropriately slid, so that the front propeller shaft 12 and the rear propeller shaft 12 The propeller shaft 15 is relatively expanded or contracted or bent.

  Here, as shown in FIG. 5A, when an external force is applied in a direction in which the front propeller shaft 12 and the rear propeller shaft 15 are separated from each other, the roller 22 is guided by the roller guide portion 21 b and the outer member 21. It moves to the vicinity of the open end 21f. At this time, the stopper member 25 reaches the opening end portion 21f of the outer member 21, but the stopper member 25 interferes with the flange portion 24c because the flange portion 24c of the locking member 24 has a step shape protruding forward. This is prevented.

  Further, as shown in FIG. 2 (b), the flange portion 24c of the locking member 24 is mounted so as to match the position of the protruding portion 21c of the cup portion 21a, and in the space between the flange portions 24c. Since the roller guide portion 21b is positioned, the roller 22 is prevented from interfering with the flange portion 24c even if the roller 22 slides to the vicinity of the opening end portion 21f (FIG. 5A).

  Furthermore, when an extremely excessive external force is applied to the propeller shaft 10 for some reason, the reduced diameter portion 12e that is thinner and weaker than other portions of the propeller shaft 10 is broken. As shown in FIG. 5B, since the reduced diameter portion 12e is formed between the stopper member 25 and the inner member 23, the front propeller shaft 12 is likely to fall off from the joint 14 by being detached from the inner member 23. become. At this time, the stopper member 25 of the front propeller shaft 12 is caught by the flange portion 24c of the locking member 24 fixed to the outer member 21, and the front propeller shaft 12 is prevented from dropping off from the joint 14.

  Thus, since the shaft holding structure 31 according to the present embodiment is configured as described above, the following effects can be obtained.

  That is, the shaft holding structure 31 according to the present embodiment is interposed between the rotatable front propeller shaft 12, the rotatable rear propeller shaft 15, the front propeller shaft 12 and the rear propeller shaft 15, And a joint 14 having an outer member 21 fixed to the rear propeller shaft 15 and integrally rotating, and an inner member 23 fixed to the front propeller shaft 12 and integrally rotated together with the outer member 21. In the shaft holding structure 31 for holding the rotating propeller shaft 10 at the time of breakage, the locking member 24 is fixed to the outer member 21 and has a flange portion 24c surrounding the front propeller shaft 12, and the inner member 23. And the flange 24c of the locking member 24 The stopper member 25 is fixed to the front propeller shaft 12 positioned between the stopper member 25 and the front propeller shaft 12 positioned between the stopper member 25 and the inner member 23. The stopper member 25 has an outer diameter larger than the minimum inner diameter of the flange portion 24c. The front propeller shaft 12 and the rear propeller shaft 15 are formed and the diameter-reduced portion 12e having the smallest diameter is provided.

  As a result, since it is not necessary to provide a guard below the propeller shaft 10 as in the prior art, the mounting position of the propeller shaft 10 is lowered as compared with the case where a guard is provided, and the floor is lowered. There is an effect that.

  In addition, when an excessively large external force is applied to the propeller shaft 10 for some reason, the reduced diameter portion 12e that is thinner and weaker than other portions breaks, and the front propeller shaft 12 attempts to fall off the joint 14. At this time, the stopper member 25 of the front propeller shaft 12 is caught by the flange portion 24c of the locking member 24 fixed to the outer member 21, and the front propeller shaft 12 is prevented from dropping off from the joint 14. As a result, there is an effect that the broken propeller shaft 10 is prevented from interfering with other surrounding parts or falling off the road surface.

In the shaft holding structure 31 according to the present embodiment, the case where the holding structure 31 is provided in the tripod type constant velocity joint has been described. However, in the shaft holding structure according to the present invention, it is provided in another constant velocity joint. May be.
For example, the holding structure may be provided in a Zepper type joint or a Barfield type joint constituted by a plurality of balls instead of the roller 22 in the tripod type constant velocity joint.

Further, in the shaft holding structure 31 according to the present embodiment, the case where the holding structure 31 is provided in the tripod type constant velocity joint in which the roller 22 can slide has been described. However, in the shaft holding structure according to the present invention, The tripod type constant velocity joint may be used.
For example, it is composed of three rollers each fitted to three support shafts, and three cylindrical grooves are formed on the inner peripheral side of the outer member, and each roller is rotatably supported by this cylindrical groove. The fixed type tripod type constant velocity joint that does not move in the axial direction may be used.

  Further, in the shaft holding structure 31 according to the present embodiment, the case where the propeller shaft 10 is provided with the holding structure 31 has been described. However, in the shaft holding structure according to the present invention, this shaft has at least one of left and right sides. The front drive shaft may be configured, or at least one of the left and right rear drive shafts may be configured.

  In the shaft holding structure 31 according to the present embodiment, the reduced diameter portion 12e is formed adjacent to the front side of the spline external teeth 12a of the front propeller shaft 12 and has a short shaft shape. In such a shaft holding structure, it is only necessary to be formed between the stopper member 25 and the inner member 23. For example, a propeller shaft is formed by forming a groove having a V-shaped or U-shaped cross section in a part of the portion. You may form a reduced diameter part so that it may become a site | part with the smallest diameter.

  As described above, the shaft holding structure according to the present invention has a structure in which the stopper member and the locking member are locked and the shaft is locked even if the shaft breaks when an excessively large external force is applied to the shaft for some reason. It can be prevented from falling off, and the mounting position of the shaft is lowered by not using a guard as in the prior art, and it is useful for all shaft holding structures that can realize a lower floor.

10 Propeller shaft 12 Front propeller shaft (first shaft)
12e Reduced diameter portion 14 Joint 15 Rear propeller shaft (second shaft)
21 Outer member 22 Roller 23 Inner member 24 Locking member 24c Flange part 25 Stopper member 31 Shaft holding structure

Claims (1)

A rotatable first shaft;
A rotatable second shaft;
An outer member that is interposed between the first shaft and the second shaft, is fixed to the second shaft and integrally rotates, and is fixed to the first shaft and rotates integrally with the outer member. A joint having an inner member that rotates together,
In the shaft holding structure for holding the shaft that rotates integrally with the shaft when broken,
A locking member fixed to the outer member and having a flange portion surrounding the first shaft;
A stopper member fixed to the first shaft located between the inner member and the flange portion of the locking member, and having an outer diameter larger than a minimum inner diameter of the flange portion;
A reduced diameter portion formed on the first shaft located between the stopper member and the inner member and having the smallest diameter in the first shaft and the second shaft;
A shaft holding structure comprising:

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