JP2016080046A - Constant velocity joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a constant velocity joint in which a compression load necessary for compression does not become abruptly large.SOLUTION: A constant velocity joint 1 which connects a front-side first shaft 111 and a rear-side second shaft 112 comprises: a cylindrical outer ring member 10 which is joined to the second shaft 112 at a rear side, and opened at a front side; an inner ring member 20 which moves in the outer ring member 10 in an axial direction; a stub shaft 30 which is connected to the first shaft 111 at a front side, and fixed to the inner ring member 20 at a rear side; a boot 40 which blocks a clearance between the outer ring member 10 and the stub shaft 30, is fixed to the stub shaft 30 at a front side, and elastically deformable; a cylindrical boot adapter 50 which is fixed to the outer ring member 10 at a rear side, and fixed with the boot 40 at a front side; and a cylindrical heavy-thickness ring 60 which is fit to the inside of the boot adapter 50, and thicker than the booth adapter 50.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a constant velocity joint.

  A rear-wheel drive vehicle or a four-wheel drive vehicle in which an internal combustion engine (power source) is mounted on the front side of the vehicle body and the rear wheels are driven by the power of the internal combustion engine includes a propulsion shaft (propeller shaft) at the lower center of the vehicle body. The power of the internal combustion engine (transmission) is transmitted to the rear wheels via the propulsion shaft. The propulsion shaft is divided by an appropriate length because the resonance point (resonance speed) needs to be set higher than the practical speed range. For example, when divided into two, the propulsion shaft includes a first shaft on the front side (one side), a second shaft on the rear side (the other side), and a constant velocity joint that connects the first shaft and the second shaft. It comprises and is comprised (refer patent document 1).

  By the way, in order to suppress the impact on the passengers when the vehicle collides forward, an easily deformable region (crushable zone) is provided between the internal combustion engine and the passenger compartment, and the collision energy is absorbed in this crushable zone. There is technology to do. In this case, if the propulsion shaft becomes a replacement rod, the backward movement of the internal combustion engine and the transmission is hindered. Therefore, the propulsion shaft is required to have a function of contracting when a certain load is applied in the axial direction.

  Here, for example, when the propulsion shaft includes a front first shaft, a rear second shaft, and a constant velocity joint that connects the first shaft and the second shaft, the contraction operation of the propulsion shaft will be described. The constant velocity joint includes, for example, a double offset type, an outer ring member that is open on the front side and joined to the second shaft on the rear side, an inner ring member that slides in the outer ring member in the axial direction, and a front side that is the first shaft. And a shaft member whose rear side is fixed to the inner ring member.

  When a backward load is applied to the propulsion shaft due to a frontal collision, the first shaft, the shaft member, and the inner ring member are moved backward together, and the inner ring member is attached to the cap provided on the bottom wall portion on the rear side of the outer ring member. bump into. Next, after breaking through the cap, the first shaft, the shaft member and the inner ring member are further retracted together.

  Next, the stopper piece for fixing the bearing that supports the shaft member abuts against the front end surface of the outer ring member after compressing the cylindrical boot adapter. The boot adapter is a metal cylindrical member for attaching the boot to the outer ring member. The boot is a rubber annular member that closes a gap formed between the front opening of the outer ring member and the shaft member.

JP 2005-147276 A

  Here, since the boot adapter is a thin cylindrical member, the rigidity in the axial direction is low, and the boot adapter is compressed and deformed with a relatively small compressive load. On the other hand, since the outer ring member is a thick cylindrical member, the rigidity in the axial direction is high and compression deformation is difficult. Therefore, when the stopper piece collides with the outer ring member in the contraction process of the propulsion shaft, the backward compressive load required to contract the propulsion shaft suddenly increases (see the comparative example in FIG. 8). In this case, the collision load is not absorbed during the contraction process of the propulsion shaft, and there is a possibility that an impact may act on the vehicle body and the occupant. In addition, the crushable zone may not be deformed as planned.

  Then, this invention makes it a subject to provide the constant velocity joint from which the compression load required for compression does not become large suddenly.

  As means for solving the problems, the present invention is a constant velocity joint that connects the first shaft on one side and the second shaft on the other side, and is coupled on the other side with the second shaft, A cylindrical outer ring member opened on one side, an inner ring member that moves in the axial direction within the outer ring member, a shaft member that is coupled to the first shaft on one side and the other side is fixed to the inner ring member; The gap between the outer ring member and the shaft member is closed, and one side is fixed to the shaft member, the boot is elastically deformable, the other side is fixed to the outer ring member, and the boot is fixed to one side. A constant velocity joint comprising: a cylindrical boot adapter; and a cylindrical thick cylindrical member that is fitted inside or outside the boot adapter and is thicker than the boot adapter.

  According to such a configuration, in the structure in which the boot adapter and the thick tube member are overlapped, the strength of the portion where the boot adapter and the thick tube member are overlapped (in the embodiment described later, the portion indicated by symbol P in FIG. 2). Is higher than the strength of the portion of the boot adapter only (in the embodiment described later, the portion of the symbol Q in FIG. 2).

  Thereby, when the structure in which the boot adapter and the thick tube member overlap is compressed by the front collision, generally, (1) only the boot adapter is compressed, and (2) the boot adapter and the thick tube member are then compressed. The overlapping part will be compressed. Therefore, the compression load required for compressing the constant velocity joint does not increase suddenly, but increases stepwise or gradually. Therefore, even when an external member that compresses the boot adapter or the like (in the embodiment described later, the stopper piece 127) collides with the outer ring member after compression of the boot adapter or the like at the time of a forward collision, the compressive load that acts on the constant velocity joint Will not grow suddenly.

  In the constant velocity joint, it is preferable that one or more slits extending in the axial direction are formed in the thick tube member.

  According to such a configuration, the strength in the axial direction of the thick tube member, that is, the strength required for compression (buckling) can be appropriately adjusted by one or more slits.

  In the constant velocity joint, it is preferable that the thick tube member is fitted inside the boot adapter.

  In the constant velocity joint, the thick tube member is preferably fitted to the outside of the boot adapter.

  Further, in the constant velocity joint, when the shaft member is rotatably supported outside via a bearing, a retaining member for retaining the bearing on the other side of the bearing is fixed to the shaft member and contracts. It is preferable that the retaining member contacts and compresses the boot adapter.

  In the constant velocity joint, preferably, on one side of the boot adapter, the shaft member includes a projecting portion projecting radially outward, and when contracted, the projecting portion contacts the boot adapter and compresses.

  According to the present invention, it is possible to provide a constant velocity joint in which a compression load required for compression does not increase suddenly.

It is a top view of the propulsion shaft concerning this embodiment. It is a top view of the constant velocity joint which concerns on this embodiment. It is a perspective view of the thick ring concerning this embodiment. It is a top view explaining the effect | action of the constant velocity joint which concerns on this embodiment, and has described the state which the inner ring member collided with the bottom wall part of the outer ring member. It is a top view explaining the effect | action of the constant velocity joint which concerns on this embodiment, and has described the state which the stub shaft collided with the cap and the cap fell. It is a top view explaining the effect | action of the constant velocity joint which concerns on this embodiment, and has described the state which the stopper piece collides with a boot adapter and the boot adapter is compressing. It is a top view explaining the effect | action of the constant velocity joint which concerns on this embodiment, and has described the state which collided with the outer ring member via the boot adapter which the stopper piece compressed. It is a graph which shows one effect of the constant velocity joint concerning this embodiment.

  An embodiment of the present invention will be described with reference to FIGS. 2 to 7, the bracket 126 of FIG. 1 is omitted.

≪Composition of propulsion shaft≫
A propulsion shaft 100 (propeller shaft) according to this embodiment is mounted on a front-engine front-drive (FF) -based four-wheel drive vehicle (vehicle). The propulsion shaft 100 is a shaft that transmits power output from a transmission (not shown) arranged on the front side of the vehicle to a final reduction gear (not shown) arranged on the rear side of the vehicle. It extends. The transmission shifts power from an internal combustion engine (prime mover) disposed on the front side of the vehicle.

  The propulsion shaft 100 has a two-piece structure (a two-part structure), and includes a first shaft 111 on the front side (first shaft on one side) and a second shaft 112 on the rear side (second shaft on the other side). A constant velocity joint 1 that connects the first shaft 111 and the second shaft 112, and an intermediate bearing unit 120 that rotatably supports the propulsion shaft 100 at an intermediate position. However, the number of pieces (number of divisions) is not limited to this, and may be appropriately changed to a three-piece structure (three-division structure) or the like.

The first shaft 111 is a cylindrical metal member. A front end portion of the first shaft 111 is connected to an output shaft (not shown) of the transmission via a first universal joint 211 (cross shaft joint or the like).
The second shaft 112 is a cylindrical metal member. The rear end portion of the second shaft 112 is connected to a drive pinion shaft (not shown) of the final reduction device via a second universal joint 212 (cross shaft joint or the like).

≪Configuration of constant velocity joint≫
The constant velocity joint 1 is a joint that connects (connects) the rear end portion of the first shaft 111 and the front end portion of the second shaft 112, and is configured as a double offset type in the present embodiment. However, it may be configured as a tripport type or the like.

  As shown in FIG. 2, the constant velocity joint 1 includes an outer ring member 10, an inner ring member 20 that slides in the outer ring member 10 in the axial direction, a stub shaft 30 (shaft member), a boot 40, and a boot adapter 50. And a thick ring 60.

<Outer ring member>
The outer ring member 10 (outer race) is a bottomed cylindrical member whose front side is open, and includes a peripheral wall portion 11, a bottom wall portion 12 formed on the rear side of the peripheral wall portion 11 and having a through hole 12a at the center. It is equipped with. The rear side (the other side) of the bottom wall portion 12 is joined (coupled) to the front end portion of the second shaft 112 by welding (friction welding or the like). As a result, the outer ring member 10 rotates integrally with the second shaft 112.

  A plurality of (eight) sliding grooves 13 extending in the axial direction and opening on the front side are formed on the inner peripheral surface of the peripheral wall portion 11. The plural (eight) sliding grooves 13 are arranged at equal intervals in the circumferential direction. Each sliding groove 13 is configured such that a ball 22 described later of the inner ring member 20 slides or rolls.

  A shallow bottomed cylindrical cap 14 is detachably attached to the through hole 12a of the bottom wall portion 12. When the stub shaft 30 is retracted during the front collision, the rear end of the stub shaft 30 collides with the cap 14 and the cap 14 falls back from the bottom wall portion 12 (see FIG. 5).

<Inner ring member>
The inner ring member 20 includes a cylindrical inner ring member main body 21 (inner race), a plurality (eight pieces) of balls 22 (sliders), and a cylindrical cage 23.

  The inner ring member main body 21 has a thick cylindrical shape, and has eight (a plurality of) ball grooves 21a that extend in the axial direction on the outer circumferential surface and are arranged at equal intervals in the circumferential direction. A part of the ball 22 on the radially inner side is in contact with the ball groove 21a.

  A spline hole 21 b is formed on the inner peripheral surface of the inner ring member main body 21, and the spline hole 21 b is spline-fitted with a spline shaft 33 a formed on the outer peripheral surface of the stub shaft 30. Thereby, the inner ring member main body 21 and the stub shaft 30 are prevented from rotating relative to each other in the circumferential direction.

  The inner ring member main body 21 is sandwiched between a stopper ring 24 such as a front C-shape and a stopper ring 25 such as a rear C-shape in the axial direction. Thereby, normally, the inner ring member main body 21 and the stub shaft 30 do not move relative to each other in the axial direction. The stopper ring 24 and the stopper ring 25 are respectively inserted into grooves formed in the outer peripheral surface of the stub shaft 30 and extending in the entire circumferential direction.

  The cage 23 is fixed to the inner ring member main body 21, and a plurality (eight) holding holes 23a are formed in the circumferential direction. Further, the outer peripheral surface of the cage 23 is formed in a spherical shape, so that the cage 23 does not come into contact with the outer ring member 10 even if the stub shaft 30 is bent with respect to the outer ring member 10.

  The ball 22 is held in the holding hole 23 a, and about 1/2 of the outer side in the radial direction is in spherical contact with the sliding groove 13. Thereby, the stub shaft 30 and the outer ring member 10 can be bent with the ball 22 as a node.

  As the ball 22 slides or rolls on the sliding groove 13, the inner ring member 20 and the outer ring member 10 can move relative to each other in the axial direction. Note that grease (lubricating oil) is sealed in the constant velocity joint 1 in order to prevent wear and seizure of the ball 22 and the sliding groove 13 due to sliding or the like.

<Stub shaft>
The stub shaft 30 is a solid or hollow rod-shaped member integrally formed, and includes a large diameter part 31, a medium diameter part 32, and a small diameter part 33 from the front side toward the rear side.

  The front side (one side) of the large-diameter portion 31 is joined (coupled) to the rear end portion of the first shaft 111 by welding (friction welding or the like). Thereby, the stub shaft 30 rotates integrally with the first shaft 111. Further, a ring-shaped flange portion 31 a that protrudes radially outward is formed on the front side of the large-diameter portion 31. At the time of a front collision, the flange portion 31a collides with an outer ring 124 described later (see FIG. 4), and the bracket 126 (see FIG. 1) moves rearward and falls off the vehicle body.

  The intermediate diameter portion 32 is a portion that is rotatably supported by the intermediate bearing unit 120, and a bearing 121 described later is intermediately fitted to the intermediate diameter portion 32. Further, an enlarged diameter portion 32 a that is enlarged in steps is formed on the front side of the intermediate diameter portion 32, and the enlarged diameter portion 32 a is in contact with the front side of the inner ring of the bearing 121.

  The small diameter portion 33 is designed to have a length that is approximately ½ of the entire stub shaft 30. Thereby, at the time of a forward collision, the stub shaft 30 is satisfactorily submerged in the outer ring member 10 and the constant velocity joint 1 is contracted. As described above, the inner ring member 20 is fixed to the rear side (the other side) of the small diameter portion 33.

<Boots>
The boot 40 is an annular member, and closes the gap between the front opening of the outer ring member 10 and the stub shaft 30, and (1) prevents the grease in the constant velocity joint 1 from flowing out to the outside, (2) A member that prevents intrusion of water, dust, muddy water, and the like into the constant velocity joint 1 from the outside.

  The boot 40 includes a rear boot large diameter portion 41, a front boot small diameter portion 42, and a boot bent portion 43. The boot large-diameter portion 41, the boot small-diameter portion 42, and the boot bending portion 43 are made of rubber (elastic body), are integrally formed, and are elastically deformable.

  The boot large-diameter portion 41 is fixed to the outer ring member 10 via a cylindrical boot adapter 50 (boot fitting).

  The boot small diameter part 42 has a smaller diameter than the boot large diameter part 41 and is fitted to the small diameter part 33 of the stub shaft 30. The boot small-diameter portion 42 is fastened by a boot band 44 from the outside in the radial direction, and the boot small-diameter portion 42 and the small-diameter portion 33 of the stub shaft 30 are in good contact.

  The boot bending portion 43 is formed between the front end of the boot large-diameter portion 41 and the front end of the boot small-diameter portion 42, has a horizontal U shape in a cross-sectional view, and is a bendable portion. Thereby, the boot large diameter part 41 and the boot small diameter part 42 can change a relative position freely in an axial direction and a radial direction.

<Boot adapter>
The boot adapter 50 is a cylindrical member for attaching the boot 40 to the outer ring member 10. The boot adapter 50 includes a cylindrical outer fitting portion 51, a ring-shaped portion 52 that extends radially inward from the front end of the outer fitting portion 51, and has a ring shape when viewed in the axial direction, and a radially inner end of the ring-shaped portion 52. A grip portion 53 extending forward from the head.

  The outer fitting portion 51 is a portion that is fitted and fixed to the front side of the outer ring member 10. An O-ring 71 (seal member) is provided between the outer fitting portion 51 and the outer ring member 10 to enhance the sealing performance.

The ring-shaped portion 52 sandwiches the flange portion 62 of the thick ring 60 with the outer ring member 10 in the axial direction. That is, the ring-shaped part 52 presses the flange part 62 against the outer ring member 10.
For example, if a rubber layer (elastic layer) that is elastically deformable is formed on the rear surface of the ring-shaped portion 52 and the space between the boot adapter 50 and the outer ring member 10 is sealed, the O-ring 71 is omitted. I'm going.

  The grip portion 53 is a portion that grips the boot large-diameter portion 41 of the boot 40. Specifically, the front end side (front side) of the grip portion 53 is folded back radially inward to form a folded portion 53a, and is gripped by inserting the boot large-diameter portion 41 into the folded portion 53a.

<Thick ring>
The thick ring 60 is a cylindrical metal member fitted inside the boot adapter 50. The thick ring 60 is formed thicker than the boot adapter 50, that is, the thickness of the plate material forming the thick ring 60 is larger than the thickness of the plate material forming the boot adapter 50. Specifically, for example, the thickness of the thick ring 60 (for example, 1.6 mm) is formed to be about twice the thickness of the boot adapter 50 (for example, 0.8 mm). The thick ring 60 and the boot adapter 50 are formed by performing a single metal plate, pressing, bending, drawing, or the like.

  The thick ring 60 includes a cylindrical part 61 having a cylindrical shape, and a flange part 62 extending in a radially outward direction from the rear end of the cylindrical part 61 and having a ring shape.

<Thick ring-cylindrical part>
The cylindrical portion 61 is a portion that fits inside the grip portion 53 and is press-fitted into the grip portion 53. However, the cylindrical part 61 may be joined (fixed) to the grip part 53 by welding or the like.

  The axial length of the cylindrical portion 61 is designed to be about ¼ of the axial length of the grip portion 53. Here, the cylindrical part 61 is thicker than the grip part 53 (boot adapter 50) as described above. Therefore, in the axial direction, the strength of the overlapping portion (symbol P) of the cylindrical portion 61 and the gripping portion 53 (load required for buckling of the cylindrical portion 61) is higher than the strength of the portion of the gripping portion 53 only (symbol Q). It has become.

  That is, “the load required for compressing only the grip portion 53 <the load required for compressing the overlapping portion of the cylindrical portion 61 and the grip portion 53”. Note that, in the axial direction, the strength of the overlapping portion (symbol P) of the cylindrical portion 61 and the grip portion 53 is set lower than the strength of the outer ring member 10.

  At the time of a forward collision, the portion (symbol Q) of only the gripping portion 53 is generally compressed, and then the overlapping portion (symbol P) of the cylindrical portion 61 and the gripping portion 53 is compressed and then collides with the outer ring member 10. become. In this case, the compressive load required for compressing the gripping portion 53 and the cylindrical portion 61 increases stepwise until it collides with the outer ring member 10 (see FIG. 8), so that the stopper piece 127 is applied to the outer ring member 10. At the time of collision, the compressive load acting on the propulsion shaft 100 is prevented from suddenly increasing.

<Thick ring-cylindrical part-slit>
A plurality of (here, four) slits 63 are formed in the cylindrical portion 61. However, the number of slits 63 is freely changeable. The plurality of slits 63 are arranged at equal intervals (here, 90 ° intervals) in the circumferential direction. The front side of each slit 63 is open to the outside.

  By forming the slit 63 in the cylindrical portion 61 in this way, the strength of the cylindrical portion 61 in the axial direction (the load required for buckling of the cylindrical portion 61) is adjusted. That is, as the number of slits 63 increases, the width of the slits 63 increases, and the number of the slits 63 increases, the strength of the cylindrical portion 61 in the axial direction decreases. In addition, the strength of the cylindrical portion 61 in the axial direction can be adjusted by changing the thickness and length of the cylindrical portion 61. Furthermore, the strength of the cylindrical portion 61 can be adjusted by forming ribs (convex portions) extending in the axial direction (front-rear direction) on the inner peripheral surface or the outer peripheral surface of the cylindrical portion 61.

<Thick ring-flange part>
As described above, the flange portion 62 is sandwiched between the ring-shaped portion 52 of the boot adapter 50 and the outer ring member 10 in the axial direction. Thereby, the thick ring 60 is fixed and positioned with respect to the outer ring member 10 in the circumferential direction and the axial direction.
For example, if a rubber layer (elastic layer) that can be elastically deformed is formed on the rear surface of the flange portion 62 and the outer ring member 10 is sealed, the O-ring 71 can be omitted.

<Intermediate bearing unit>
The intermediate bearing unit 120 is a unit that rotatably supports the propulsion shaft 100 at an intermediate position. The intermediate bearing unit 120 includes a bearing 121, an inner ring 122, a mount 123, an outer ring 124, a collar 125 (ring bracket), a bracket 126, and a stopper piece 127 (a retaining member). .

  The bearing 121 is constituted by a shielded radial ball bearing and is fitted on the medium diameter portion 32 of the stub shaft 30. The front side of the inner ring is in contact with the above-described enlarged diameter portion 32a, and the rear side of the inner ring is in contact with the stopper piece 127. Thus, the bearing 121 is fixed to the stub shaft 30 in the axial direction.

  The inner ring 122 is a cylindrical member that is externally fitted to the bearing 121. The front side of the inner ring 122 has a reduced diameter due to a step difference, and the reduced diameter part is in contact with the front side of the outer ring of the bearing 121. In front of the bearing 121, an oil seal 128 is provided between the enlarged diameter portion 32 a (stub shaft 30) and the inner ring 122. An oil seal 129 is provided behind the bearing 121 and between the cylindrical portion 127 a and the inner ring 122.

  The mount 123 (anti-vibration rubber) is an annular member integrally formed of rubber (elastic body), is provided between the inner ring 122 and the outer ring 124, and is vulcanized to the inner ring 122 and the outer ring 124. It is glued. Thereby, the vibration of the inner ring 122 (propulsion shaft 100) is absorbed and attenuated by the mount 123, and is difficult to be transmitted to the outer ring 124 (vehicle body).

  The outer ring 124 is a member having a cylindrical shape (annular shape) having a diameter larger than that of the inner ring 122, and is arranged at the same center at a predetermined interval on the radially outer side of the inner ring 122. A cylindrical collar 125 is fixed to the outside of the outer ring 124. A bracket 126 (see FIG. 1) having a substantially C shape when viewed in the axial direction is fixed to the outer side of the collar 125, and the bracket 126 is fixed to a lower portion of a vehicle body (outside) (not shown).

  The bracket 126 has a 1/2 cylindrical bracket body 126a fixed to the outer peripheral surface of the lower half of the collar 125, and extends outward from the respective ends (left end and right end) of the bracket body 126a in the vehicle width direction and is bolted to the vehicle body. A fastened portion 126b.

  Each fastened portion 126b is formed with a bolt hole 126c through which a bolt (not shown) is inserted. The front side of the bolt hole 126c is open to the outside. As a result, when a rearward load is applied to the bracket 126 at the time of a front collision, the bracket 126 moves rearward and easily falls off the bolt.

<Stopper piece>
The stopper piece 127 is a cylindrical member that is press-fitted and fixed to the middle diameter portion 32 on the rear side of the bearing 121 and prevents the bearing 121 from coming out backward. The stopper piece 127 includes a cylindrical cylindrical portion 127a that is externally fitted to the medium diameter portion 32, and a ring-shaped flange portion 127b (protruding portion) that protrudes radially outward from the rear end of the cylindrical portion 127a. .

  When the stub shaft 30 moves backward during a frontal collision, the flange portion 127b collides with the boot adapter 50 (see FIG. 6), and the boot adapter 50 is compressed. Further, the flange portion 127b collides (contacts) with the outer ring member 10 via the boot adapter 50 after compression (see FIG. 7).

≪Function and effect of constant velocity joint (propulsion shaft) ≫
According to such a constant velocity joint 1 (propulsion shaft 100), the following effects are obtained.
When the vehicle collides forward, the internal combustion engine and the transmission move backward, and a backward load is input to the first shaft 111. Thereby, the 1st axis | shaft 111, the stub shaft 30, and the inner ring member 20 are pushed back integrally. In addition, since the ball 22 of the inner ring member 20 rolls in the sliding groove 13, the outer ring member 10 and the second shaft 112 remain substantially at the current positions.

  Thereafter, when the retraction of the first shaft 111 and the like further proceeds, the cage 23 of the inner ring member 20 collides with the bottom wall portion 12 of the outer ring member 10 (see FIG. 4). When the stub shaft 30 is pushed rearward with the cage 23 of the inner ring member 20 colliding with the bottom wall portion 12, the front stopper ring 24 is distorted and falls off the stub shaft 30, and the stub shaft 30 and the first stub shaft 30. The shaft 111 is pushed further backward.

Thereafter, when the backward movement of the first shaft 111 and the like further proceeds, the rear end of the stub shaft 30 collides with the cap 14. As a result, the cap 14 falls off the bottom wall portion 12 (see FIG. 5).
The backward load required for the front stopper ring 24 to drop off and the backward load required for the cap 14 to drop off are very small (see FIG. 8).

  Thereafter, when the first shaft 111 and the like further retract, the flange portion 127b of the stopper piece 127 collides with the grip portion 53 of the boot adapter 50 (see FIG. 6). Then, the compression deformation of the grip portion 53 starts.

  Here, as described above, in the axial direction, the strength of only the grip portion 53 (symbol Q) is lower than the strength of the portion where the grip portion 53 and the cylindrical portion 61 of the thick ring 60 overlap (symbol P). Therefore, generally, after the portion (symbol Q) of only the grip portion 53 is compressed and deformed, the overlapping portion (reference P) is compressively deformed.

  Therefore, after the load required for compressing only the grip portion 53 (reference symbol Q) acts on the constant velocity joint 1 (propulsion shaft 100), the load required for compressing the overlapping portion (reference symbol P) is applied. It will work (see FIG. 8). The load required to compress the overlapping portion (reference P) is gradually increased as the stopper piece 127 (stub shaft 30) moves backward because the cylindrical portion 61 (thickness ring 60) is thicker. growing. That is, the compression load required for compression of the constant velocity joint 1 (propulsion shaft 100) does not suddenly increase.

  Thereafter, when the first shaft 111 and the like further retract, the grip portion 53 of the boot adapter 50 and the cylindrical portion 61 of the thick ring 60 are almost completely compressed and deformed and buckled, and the stopper piece 127 is gripped by compressive deformation. It collides with the outer ring member 10 via the portion 53 and the cylindrical portion 61. In this case, since the compressive load acting on the constant velocity joint 1 (propulsion shaft 100) is gradually increased, when the stopper piece 127 collides with the outer ring member 10, the backward load acting on the outer ring member 10 is suddenly increased. It will never grow.

  Thereby, when the stopper piece 127 collides with the outer ring member 10, a sudden impact does not act on the vehicle body and the occupant. That is, the load required for compression (buckling) of the constant velocity joint 1 (propulsion shaft 100) does not suddenly increase but gradually increases, and no sudden impact acts on the vehicle body and the occupant. Since the constant velocity joint 1 (propulsion shaft 100) is smoothly compressed, the crushable zone can be deformed as planned, and the impact (collision energy) due to the front collision can be absorbed well.

≪Modification≫
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to this, For example, you may change as follows.

  In the above-described embodiment, the configuration in which the thick ring 60 is fitted inside the boot adapter 50 is exemplified. However, for example, the thick ring 60 may be fitted outside the grip portion 53 of the boot adapter 50. Good. In this case, the thick ring 60 can be easily attached to the grip portion 53. In addition, a slit that penetrates the thick ring 60 in the axial direction is formed so that the diameter can be reduced, and the thick ring 60 is reduced in diameter by a band (not shown) so as to be in close contact with the outer peripheral surface of the grip portion 53. Also good. In addition, the thick ring 60 may be joined (fixed) to the grip portion 53 by welding or the like.

  In the above-described embodiment, as illustrated in FIG. 3, the configuration in which the slit 63 is formed only in the cylindrical portion 61 is illustrated. However, for example, the slit 63 penetrates the thick ring 60 in the axial direction and is thick. The ring 60 may have a C shape. In this case, if the thick ring 60 is configured to be fitted into the gripping portion 53 of the boot adapter 50 with the diameter slightly reduced, the thick ring 60 is brought into close contact with the gripping portion 53 by the spring force in the diameter increasing direction. And is well positioned in the circumferential and axial directions.

  In the embodiment described above, as shown in FIG. 1, the constant velocity joint connects the front first shaft 111 (the first shaft on one side) and the rear second shaft (the second shaft on the other side). However, for example, the propulsion shaft may be composed of one piece, and a constant velocity joint may be provided instead of the first universal joint 211 (or the second universal joint) in FIG. And this constant velocity joint is good also as a structure which connects the output shaft (1st axis | shaft on one side) and the propulsion shaft (2nd axis | shaft on the other side) of a transmission.

  In this case, (a) the front side (one side) of the stub shaft 30 is joined to the rear end of the output shaft, and the rear side (other side) of the outer ring member 10 is joined to the front end of the one-piece propulsion shaft. (B) The stub shaft 30 and the outer ring member 10 are arranged in the front-rear direction, and the front side (the other side) of the outer ring member 10 is joined (or splined) to the rear end of the output shaft. The rear side (one side) may be joined to the front end of the one-piece propulsion shaft. In this case, when the constant velocity joint is contracted, for example, a large-diameter flange portion (projecting portion) formed on the stub shaft 30 collides with the boot adapter 50.

  In addition, it is good also as a structure provided with a constant velocity joint instead of the 1st universal joint 211 (or 2nd universal joint 212) of FIG. In other words, the constant velocity joint may be configured to connect the output shaft (the first shaft on one side) of the transmission and the first shaft (the second shaft on the other side) of the two-piece propulsion shaft 100. Good.

  In the above-described embodiment, the configuration in which the stopper piece 127 (fixing member) fixed to the stub shaft 30 collides with the boot adapter 50 is exemplified. However, for example, the stub shaft 30 is radially outward on the front side of the boot adapter 50. It is good also as a structure which comprises the ring-shaped flange part (projection part) which protrudes in this, and this flange part collides with the boot adapter 50. FIG.

1 constant velocity joint 10 outer ring member 20 inner ring member 30 stub shaft (shaft member)
40 Boots 50 Boot adapter 60 Thick ring (thick tube member)
61 Cylindrical part 62 Flange part 63 Slit 100 Propulsion shaft 111 First axis (first axis on one side)
112 Second axis (first axis on the other side)
121 Bearing 127 Stopper piece (fixing member)

Claims (6)

A constant velocity joint connecting the first shaft on one side and the second shaft on the other side,
A cylindrical outer ring member coupled to the second shaft on the other side and having one side opened;
An inner ring member that moves in the axial direction within the outer ring member;
A shaft member coupled to the first shaft on one side and the other side fixed to the inner ring member;
A boot that closes a gap between the outer ring member and the shaft member, is fixed to the shaft member on one side, and is elastically deformable;
A cylindrical boot adapter having the other side fixed to the outer ring member and the boot fixed to one side;
A tubular thick tube member that fits inside or outside the boot adapter and is thicker than the boot adapter;
A constant velocity joint characterized by comprising: The constant velocity joint according to claim 1, wherein the thick cylindrical member is formed with one or more slits extending in an axial direction. The constant-velocity joint according to claim 1, wherein the thick tube member is fitted inside the boot adapter. The constant-velocity joint according to claim 1, wherein the thick tube member is fitted to the outside of the boot adapter. The shaft member is rotatably supported outside via a bearing,
A retaining member for retaining the bearing on the other side of the bearing is fixed to the shaft member,
The constant velocity joint according to any one of claims 1 to 4, wherein, when contracted, the retaining member contacts and compresses the boot adapter. On one side of the boot adapter, the shaft member includes a protruding portion that protrudes radially outward,
The constant velocity joint according to any one of claims 1 to 4, wherein, when contracted, the protrusion comes into contact with the boot adapter and compresses.

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