WO2010097969A1

WO2010097969A1 - Coupling structure of snap ring for vehicle

Info

Publication number: WO2010097969A1
Application number: PCT/JP2009/055492
Authority: WO
Inventors: 隆幸杉本
Original assignee: トヨタ自動車株式会社
Priority date: 2009-02-24
Filing date: 2009-03-19
Publication date: 2010-09-02
Also published as: JP2010196765A

Abstract

Provided is a coupling structure of a snap ring for a vehicle wherein the durability is enhanced by relaxing stress concentration on a snap ring fitting groove. As shown at E in Fig. 7, a coupling structure of a snap ring (120) has a gap entirely in the depth direction (direction of an arrow DP in Fig. 7) of an inner circumferential groove (128) between the side wall surface (138) thereof on the side receiving a thrust force F_TH in the direction of the central axis (C)and the side surface (140) of the snap ring (120) facing the side wall surface (138) when the thrust force F_TH acts on a bearing (112) on the rear wheel side at a pair of opening ends (136) of a transfer case (42) where the inner circumferential groove (128) is broken off so as to be opened in the circumferential direction. The gap is formed by reducing the thickness of the snap ring (120) or widening the lateral groove of the inner circumferential groove (128). Consequently, the thrust force F_THdoes not act directly on the side wall surface (138) at the opening end (136) because of the gap. Since stress concentration is relaxed at the opening end (136), durability of the transfer case (42) can be enhanced.

Description

Connecting structure of snap ring for vehicle

The present invention relates to a technique for improving the reliability of a connecting structure of a vehicle snap ring.

2. Description of the Related Art Conventionally, a connecting structure of a vehicle snap ring in which a bearing fitted in a fitting hole of a support member fixed to a vehicle body is fixed to the support member in a uniaxial direction by a snap ring is known. For example, the connection structure of the snap ring for vehicles disclosed by FIG. 5, FIG. 6 of patent document 1 is it. In the connection structure of the vehicle snap ring disclosed in Patent Document 1, the snap ring has a rectangular cross section as a whole, and an annular ring portion and the diameter of the ring portion protruding in the radial direction from the ring portion are enlarged. Alternatively, a pair of operation units for reducing the size is provided. Further, an annular inner circumferential groove is provided on the inner circumferential surface of the fitting hole, and an annular outer circumferential groove facing the annular inner circumferential groove is provided on the outer circumferential surface of the bearing. Then, in a state where the bearing is fitted in the fitting hole, the snap ring is fitted over both the annular inner circumferential groove and the annular outer circumferential groove, so that the bearing is uniaxially arranged with respect to the support member. It is fixed so as not to move.

In addition, in a state where the snap ring is attached to the support member, a part around the fitting hole is cut away so that the operation portion of the snap ring does not interfere with the support member. The annular inner circumferential groove is cut off at the cutout portion of the cutout and opens in the circumferential direction. That is, the support member has a pair of open end portions whose annular inner peripheral grooves are opened in the circumferential direction.

JP 2005-207571 A JP 2006-349162 A JP-A-9-220636

By the way, assuming that a thrust load is applied to the bearing in the uniaxial direction, in the support member, the side wall surface of the annular inner circumferential groove facing the thrust load receives the thrust load. become. In that case, since the side wall surface is interrupted at the opening end portion of the support member, stress concentration tends to occur at the opening end portion as compared with other portions.

However, although the snap ring has a thin thickness in the uniaxial direction at a part of the tip of the snap ring, it does not reach the full width in the radial direction. In the structure, the thrust load is received by the entire side wall surface including the opening end. Then, stress concentration occurs at the opening end of the support member, and the durability of the support member may be reduced. Such a problem is not yet known.

The present invention has been made against the background of the above circumstances, and the object of the present invention is to provide a connecting structure for a vehicle snap ring that improves stress by reducing stress concentration at the opening end. It is to provide.

In order to achieve the above object, the gist of the present invention includes (a) a fitting hole centered on one axis and an inner circumferential groove provided around the one axis on the inner circumferential surface of the fitting hole. With respect to the fixed member, the outer peripheral groove opposite to the inner peripheral groove is provided on the outer peripheral surface, and the fitting member inserted into the fitting hole is snapped into the inner peripheral groove and the outer peripheral groove, A vehicle snap ring coupling structure for fixing in the uniaxial direction, wherein (b) the annular inner circumferential groove is interrupted in a circumferential direction in which a part around the fitting hole of the fixing member is notched. In at least one of the pair of opening end portions of the fixing member opened in the case, when the pressing force in the uniaxial direction acts on the fitting member, the side wall surface of the inner peripheral groove on the side receiving the pressing force And the side surface of the snap ring facing the side wall surface During is to have a gap over the entire depth direction of the inner peripheral groove.

In this way, the pressing force does not act directly on the side wall surface on the side receiving the pressing force due to the gap on at least one of the opening end portions. Therefore, stress concentration is relaxed at the opening end portion, and the durability of the fixing member can be improved. And the reliability of the connection structure of this vehicle snap ring can be improved. In addition, by having the said clearance gap in both of a pair of said opening edge part, durability of the said fixing member can be improved further and the reliability of the connection structure of the said snap ring for vehicles can be improved.

Here, preferably, the thickness of the snap ring in the uniaxial direction is thinner than the other portions at the opening end. In this way, by configuring the snap ring so that the gap is generated, the durability of the fixing member is improved without requiring a change in the shape of the fixing member for generating the gap. Can be made.

Also preferably, the thickness of the snap ring in the uniaxial direction is continuously thinner than the other portions at the opening end. In this way, the snap ring avoids or suppresses stress concentration due to a change in the thickness of the snap ring, thereby suppressing a decrease in durability.

Also preferably, the groove width in the uniaxial direction of the inner circumferential groove is wider than the other portions at the opening end. If it does in this way, the shape of the inner peripheral groove is formed so that the gap is generated at the opening end thereof, and the fixing member is not required to change the shape of the snap ring for generating the gap. The durability of can be improved. Note that, at the opening end, the uniaxial thickness of the snap ring may be reduced and the uniaxial groove width of the inner circumferential groove may be increased. There is no problem.

Also preferably, the groove width in the uniaxial direction of the inner circumferential groove is continuously wider than the other portions at the opening end. If it does in this way, the stress concentration by the change of the said groove | channel width | variety is avoided thru | or suppressed at the opening edge part, and durability fall is suppressed.

Preferably, (a) the fixing member is a transfer case that distributes the driving force of the vehicle to a plurality of driving wheels, and (b) the fitting member is connected to the fixing member. An output shaft bearing that rotatably supports the output shaft about the one axis. In this way, the durability of the transfer can be improved against the uniaxial pressing force applied to the output shaft.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a skeleton diagram illustrating a configuration of a front and rear wheel drive vehicle based on a front engine rear wheel drive (FR) having a vehicle power transmission device to which the present invention is preferably applied. FIG. 2 is a schematic diagram of a transfer provided in the power transmission device of FIG. 1. It is sectional drawing which showed the inside of the transfer shown in FIG. 2 simply. It is the figure which expanded the IV section of FIG. FIG. 5 is a diagram showing a schematic shape of a snap ring for fixing a rear wheel side bearing in the axial direction with respect to the fitting hole of the transfer shown in FIG. 4 in a single state. FIG. 5 is an AA arrow view of the transfer case and the rear wheel side bearing as viewed in the direction of arrow A in FIG. 4. FIG. 7 is a view showing an inner peripheral groove and a snap ring of the transfer case at one of a pair of opening end portions of the transfer case of FIG. 3, that is, at a portion B shown in FIG. 6. FIG. 8 is a view for explaining another snap ring connection structure different from that corresponding to FIG. 7 in the portion B shown in FIG. 6.

Explanation of symbols

8: Vehicle 20l, 20r: Front wheel (drive wheel)
22: Transfer 30l, 30r: Rear wheel (drive wheel)
42: Transfer case (fixing member, case)
48: First output shaft (output shaft)
112: Rear wheel side bearing (fitting member, output shaft bearing)
120: Snap ring 124: Fitting hole 126: Inner peripheral surface 128: Inner peripheral groove 130: Outer peripheral surface 132: Outer peripheral groove 134: Notch 136: Open end 138: Side wall surface 140: Side surface C: Axle (uniaxial)
F _TH : Pressing force

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a skeleton diagram illustrating the configuration of a front and rear wheel drive vehicle based on a front engine rear wheel drive (FR) having a power transmission device 10 for a vehicle 8 to which the present invention is preferably applied. In FIG. 1, the driving force (torque) generated by the engine 12 that is the driving force source of the vehicle 8 is transmitted to the transfer 22 via the automatic transmission 14. The driving force transmitted to the transfer 22 is distributed to a front propeller shaft 23 that is a front wheel driving force transmission shaft and a rear propeller shaft 24 that is a rear wheel driving force transmission shaft. The driving force transmitted to the front propeller shaft 23 is transmitted to a pair of left and right front wheels 20l and 20r via a front wheel differential gear device (front differential) 16 and a pair of left and right front wheel axles 18l and 18r. . On the other hand, the driving force transmitted to the rear propeller shaft 24 is transmitted to the left and right pair of rear wheels 30l and 30r via the rear wheel differential gear device 26 and the left and right pair of rear wheel axles 28l and 28r. . That is, the transfer 22 distributes the driving force of the vehicle 8 to each of a plurality of driving wheels, that is, the front wheels 20 and the rear wheels 30. The power transmission device 10 includes an engine 12, an automatic transmission 14, a torque converter that is a power transmission mechanism (not shown) interposed between the engine 12 and the automatic transmission 14, a transfer 22, a front A propeller shaft 23, a front wheel differential gear device 16, a front wheel axle 18, a rear propeller shaft 24, a rear wheel differential gear device 26, and a rear wheel axle 28 are provided.

The engine 12 is, for example, an internal combustion engine such as a gasoline engine or a diesel engine that generates a driving force by combustion of fuel injected in a cylinder. The automatic transmission 14 is, for example, a stepped automatic transmission (automatic transmission) that outputs the rotation input from the engine 12 by decelerating or increasing the speed at a predetermined gear ratio γ. Any one of the first gear, the reverse gear, and the neutral is selectively established, and the speed conversion corresponding to each gear ratio γ is performed. The input shaft of the automatic transmission 14 is connected to the output shaft of the engine 12 via a torque converter (not shown).

FIG. 2 is a skeleton diagram of the transfer 22 of FIG. In FIG. 2, the axes of the input shaft 56, the first output shaft 48, the second output shaft 50, the first shift fork shaft 88, and the second shift fork shaft 92, which will be described later, are in a common plane. It is the expanded view shown. In FIG. 2, the transfer 22 includes a transfer case 42 as a non-rotating member connected to the vehicle rear side of the transmission case 40 of the automatic transmission 14. In addition, the transfer 22 is supported in the transfer case 42 so as to be rotatable around an axis C (one axis) and an auxiliary transmission 46 mainly composed of a single pinion type planetary gear unit 44 in the transfer case 42. A center that distributes driving force (torque) to the first output shaft 48 connected to the rear propeller shaft 24 and the second output shaft 50 connected to the front propeller shaft 23 while allowing the respective rotational differences. The differential (central differential) 52 and either of the two power transmission paths from the sub-transmission 46 to the center differential 52 are connected to each other, so that the low speed side gear stage or the high speed side gear stage is selected. An engagement clutch device 53 to be established; an operation that allows the rotational difference of the center differential 52, that is, a differential lock device 54 that locks the differential; Have a common axis on the C. The transfer 22 shifts the rotation of the input shaft 56 supported by the transfer case 42 so as to be rotatable about the axis C, and outputs from the first output shaft 48 and the second output shaft 50 in a differential state or a direct connection state, respectively. To do. The input shaft 56 is connected to the output shaft 58 of the automatic transmission 14 via a spline fitting joint or the like, and is driven to rotate by a driving force (torque) input from the engine 12 via the automatic transmission 14. It is what The axis C corresponds to one axis of the present invention, the transfer case 42 corresponds to the fixing member of the present invention, and the first output shaft 48 corresponds to the output shaft of the transfer of the present invention.

The planetary gear unit 44 is disposed so as to be non-rotatable around the axis C with respect to the outer peripheral surface of the input shaft 56, and is disposed substantially concentrically with the sun gear S1 and fixed to the vehicle body. A carrier CA1 that supports a ring gear R1 that is non-rotatably connected around a shaft center C to a transfer case 42 that is a fixed member, and a sun gear S1 and a plurality of pinion gears P1 that mesh with the ring gear R1 and that can revolve around the sun gear S1. And have. Therefore, the rotational speed of the sun gear S1 is constant with respect to the input shaft 56, and the rotational speed of the carrier CA1 is decelerated with respect to the input shaft 56. Further, in the sun gear S1, a clutch gear 60 as an asynchronous member of the synchronous mesh clutch 72 that is involved in the establishment of the high speed gear stage (high speed gear stage) in the mesh clutch device 53 has an axis C relative to the sun gear S1. It is fixed so that it cannot rotate around. In addition, in the carrier CA1, a clutch gear 62 as an asynchronous member of a later-described meshing clutch 74, which is involved in the establishment of the low-speed gear stage (low-speed gear stage) in the meshing clutch device 53, has an axial center with respect to the carrier CA1. It is fixed so that it cannot rotate around C.

The center differential 52 is a well-known Torsen-type differential gear limiting device, and includes a differential case 64 that is supported on the first output shaft so as to be rotatable around the axis C, and an axial center within the differential case 64. A ring gear R2 that is connected to the first output shaft 48 so as not to rotate about C, and is arranged substantially concentrically with respect to the ring gear R2, so that the first output shaft 48 can rotate relative to the first output shaft 48 about the axis C. A carrier CA2 that supports a sun gear S2 supported on the outer periphery of one output shaft 48 and a plurality of pinion gears P2 meshing with the sun gear S2 and the ring gear R2 so as to be capable of rotating and revolving around the sun gear S2, and connected to a differential case 64. And have. The sun gear S2 is connected to a first output gear 66 supported on the first output shaft 48 so as to be rotatable about the axis C, similarly to the sun gear S2. The first output gear 66 rotates with respect to the second output gear 68 connected to the second output shaft 50 so as not to rotate around the second output shaft 50. It is transmitted via a transmission belt 70 wound around the outer periphery of the belt. In such a center differential 52, when traveling straight, torque transmitted from the planetary gear unit 44 to the differential case 64 is transmitted to the first output shaft 48 and the second output shaft 50 via the ring gear R2 and the sun gear S2, respectively. Further, at the time of turning, a part of the torque inputted from the differential case 64 to the sun gear S2 is transmitted to the ring gear R2 via the carrier CA2 and the differential case 64, and the torque from the rear is more than the torque distribution at the time of straight traveling. The distribution is transmitted to the first output shaft 48 and the second output shaft 50, respectively.

The meshing clutch device 53 has a synchronous meshing clutch 72 for establishing a high speed side gear stage and a meshing clutch 74 for establishing a low speed side gear stage. The synchronous mesh clutch 72 includes a well-known so-called synchro mechanism, and is relatively non-rotatable around the axis C and is relatively movable in the direction of the axis C by, for example, spline fitting to the differential case 64. A cylindrical sleeve 76 provided on the inner peripheral surface of the sleeve 76, and an outer peripheral tooth meshing with an inner peripheral tooth of the inner peripheral surface of the sleeve 76 so as not to rotate around the axis C and to move relative to the axis C. The clutch gear 60 disposed between the planetary gear unit 44 and the differential case 64 and fixed to the sun gear S1 as described above, and when the rotation of the sleeve 76 and the clutch gear 60 is asynchronous, the clutch gear of the sleeve 76 And a synchronizer ring (synchronization ring) 78 for preventing movement in the 60 direction. In this embodiment, the sleeve 76 corresponds to a shift ring that is moved in the direction of the axis C by a shift actuator 86 described later. The meshing clutch 74 meshes with a sleeve 76 as the shift ring and an outer peripheral tooth 80 provided on an outer peripheral portion of the sleeve 76 so as not to be rotatable about the axis C and to be relatively movable in the direction of the axis C. It has an inner peripheral tooth and is arranged on the opposite side of the outer peripheral tooth 80 from the clutch gear 62 and has the clutch gear 62 fixed to the carrier CA1 as described above. In the meshing clutch device 53 configured as described above, the sleeve 76 slides in the direction of the axis C so as to mesh with the differential case 64 and mesh with the clutch gear 60, thereby establishing the high speed side gear stage. By sliding in the direction of the axis C, the low speed side gear stage is established by engaging with the clutch gear 62 while engaging with the differential case 64. At this time, the path through which the driving force is transmitted to the differential case 64 via the carrier CA1 and the clutch gear 62 corresponds to the power transmission path that establishes the low-speed gear stage, and is driven to the differential case 64 via the sun gear S1 and the clutch gear 60. The path through which the force is transmitted corresponds to a power transmission path that establishes the high speed side gear. In the present embodiment, the differential case 64 functions as a clutch hub of the synchronous mesh clutch 72. Further, the meshing clutch device 53 is engaged and operated to shift the auxiliary transmission 46.

The differential lock device 54 is provided, for example, by spline fitting to the outer peripheral portion of the differential case 64 and, for example, by spline fitting to the differential case 64 so as not to be relatively rotatable about the axis C and to be relatively movable in the direction of the axis C. A cylindrical sleeve 82, and an outer peripheral tooth that meshes with an inner peripheral tooth of the inner peripheral surface of the sleeve 82 so as not to be rotatable about the axis C and to be relatively movable in the direction of the axis C. The clutch gear 84 is disposed between the output gear 66 and the differential case 64 and is fixed to the first output gear 66. In the differential lock device 54 configured in this way, the differential of the center differential 52 is locked by engaging the clutch gear 84 while meshing with the differential case 64 by sliding the sleeve 82 in the axial center C direction. ing. In the present embodiment, the differential case 64 functions as a clutch hub of the meshing clutch 74.

Here, the mesh clutch device 53 and the differential lock device 54 are mounted on the vehicle 8 and driven by an electronic control device (not shown) that performs output control of the engine 12, shift control of the automatic transmission 14, and the like. Is engaged. That is, in the mesh clutch device 53, the first shift fork shaft 88 that protrudes in a direction parallel to the axis C corresponding to the output member of the shift actuator 86 is parallel to the axis C by driving the shift actuator 86. Through the first shift fork 90 fixed to the first shift fork shaft 88 so as to be engageable with the sleeve 76 in the direction of the axis C and relatively rotatable about the axis C. The sleeve 76 is actuated in the direction of the axis C. In the differential lock device 54, the second shift fork shaft 92 protruding in a direction parallel to the axis C corresponding to the output member of the shift actuator 86 is driven in the direction parallel to the axis C by driving the shift actuator 86. By being actuated, the sleeve is engaged via the second shift fork 94 fixed to the second shift fork shaft 92 so as to be engageable with the sleeve 82 in the direction of the axis C and relatively rotatable about the axis C. 82 is operated in the direction of the axis C.

FIG. 3 is a cross-sectional view schematically showing the inside of the transfer 22 shown in FIG. FIG. 4 is an enlarged view of a portion IV in FIG. The transfer 22 is provided with a center differential 52, an auxiliary transmission 46, a differential lock device 54, etc., but these devices are omitted in FIG.

As shown in FIG. 3, the second output shaft 50 has one end protruding from the transfer case 42, which is the fixing member, toward the front propeller shaft 23, and the bearing 102 and the bearing 104 fitted to the transfer case 42. It is rotatably supported through A front wheel side companion flange 106 connected to the front propeller shaft 23 so as to be able to transmit power is spline-fitted to one end of the second output shaft 50 and fastened by a nut 108 so as not to drop off.

One end of the first output shaft 48 projects in the direction of the rear propeller shaft 24 from the transfer case 42, and can rotate about the axis C via a rear wheel side bearing 112 fitted to the transfer case 42. It is supported. A rear wheel side companion flange 114 connected to the rear propeller shaft 24 so as to transmit power is spline-fitted to one end of the first output shaft 48 and fastened by a nut 116 so as not to drop off. By fastening the nut 116, the first output shaft 48, the rear wheel side companion flange 114, and the inner ring member of the rear wheel side bearing 112 are integrated. The rear wheel side companion flange 114 is fixed by bolting via a rear propeller shaft 24 and a universal joint 118 arranged in series along the axis C. The universal joint 118 is a joint for allowing the axis of the first output shaft 48 and the axis of the rear propeller shaft 24 to have a certain angle without being the same axis.

The rear wheel side bearing 112 is a rear wheel side output shaft bearing that rotatably supports the first output shaft 48 around the axis C with respect to the transfer case 42. As shown in FIG. It is fixed so as not to move relative to the transfer case 42 in the direction of the axis C. Specifically, the transfer case 42 is provided with a fitting hole 124 centered on the shaft center C, and the inner peripheral surface 126 of the fitting hole 124 has an annular inner periphery around the shaft center C. A groove 128 is provided. Further, the rear wheel side bearing 112 is provided with an annular outer circumferential groove 132 opposed to the inner circumferential groove 128 in a state of being fitted into the fitting hole 124 on the outer circumferential surface 130 thereof. After such a rear wheel side bearing 112 is fitted into the fitting hole 124 of the transfer case 42, the snap ring 120 is fitted over both the inner circumferential groove 128 and the outer circumferential groove 132, whereby the rear wheel side bearing 112. Is fixed in the direction of the axis C with respect to the transfer case 42. The rear wheel side bearing 112 corresponds to the fitting member of the present invention.

As shown in FIG. 3, the rear propeller shaft 24 has an inner cylinder member 24a connected to the rear wheel side companion flange 114 via a universal joint 118, and the inner cylinder member 24a is inserted inside by spline fitting or the like. And an outer cylinder member 24b coupled to the rear wheel differential gear device 26 so as to be capable of transmitting power. The inner cylinder member 24a and the outer cylinder member 24b are mutually non-rotatable about the axis C and are It is connected so as to be relatively movable in the direction of the center C. In other words, the rear propeller shaft 24 has a structure capable of transmitting the driving force from the transfer 22 to the rear wheel 30 and extending and contracting in the direction of the axis C.

FIG. 5 is a diagram showing a schematic shape of the snap ring 120 alone. The snap ring 120 is generally called an Ω-type snap ring. The snap ring 120 includes a ring-shaped ring portion 120a that is partially cut into the inner circumferential groove 128 of the transfer case 42 and the outer circumferential groove 132 of the rear wheel side bearing 112, and a diameter from the end of the ring portion 120a. And a pair of operation portions 120b protruding outward in the direction. The snap ring 120 is, for example, a steel spring material as in a general snap ring, and has a rectangular cross section as a whole. An operation hole 120c for deforming the ring portion 120a is provided at the distal ends of the pair of operation portions 120b so as to enlarge or reduce the diameter of the ring portion 120a. In the free state of the snap ring 120, the outer diameter of the ring portion 120a is larger than the inner diameter of the fitting hole 124 of the transfer case 42, and the inner diameter of the ring portion 120a is smaller than the outer diameter of the rear wheel side bearing 112. .

The operation of attaching the snap ring 120 to the transfer case 42 will be described. First, the pair of operation portions 120b are brought close to each other to make the outer diameter of the ring portion 120a smaller than the fitting hole 124 of the transfer case 42. In this state, the snap ring 120 is inserted into the fitting hole 124 in which the rear wheel side bearing 112 is not yet fitted. Then, the operation portion 120 b is released and the snap ring 120 is fitted into the inner circumferential groove 128. Next, in a state where the snap ring 120 is fitted in the inner circumferential groove 128, the pair of operation parts 120 b are separated from each other so that the inner diameter of the ring part 120 a is larger than the outer diameter of the rear wheel side bearing 112. In this state, the rear wheel side bearing 112 is fitted into the fitting hole 124, and after the fitting is completed, the operation portion 120b is released. As a result of such attachment work, the snap ring 120 is fitted over both the inner peripheral groove 128 of the transfer case 42 and the outer peripheral groove 132 of the rear wheel side bearing 112.

FIG. 6 is an AA arrow view of the transfer case 42 and the rear wheel side bearing 112 seen in the direction of arrow A in FIG. In FIG. 6, members inside the rear wheel side bearing 112, for example, the first output shaft 48 are omitted.

As shown in FIG. 6, the transfer case 42 is fitted with the snap ring 120 so that the pair of operation portions 120b of the snap ring 120 do not interfere with the transfer case 42 in a state where the snap ring 120 is fitted in the inner circumferential groove 128 thereof. A notch 134 is provided in which a part around the joint hole 124 is notched. For this reason, the transfer case 42 is configured with a pair of opening end portions 136 that are opened in the circumferential direction with the inner circumferential groove 128 being cut off at both circumferential ends of the notch portion 134.

FIG. 7 is a view showing the inner peripheral groove 128 and the snap ring 120 of the transfer case 42 in one of the pair of open end portions 136 of the transfer case 42, that is, in the portion B shown in FIG. In the present embodiment, the other of the pair of opening end portions 136 is the same as that of FIG. 7, and therefore, one of the pair of opening end portions 136 shown in FIG. 7 will be described below.

As shown in FIG. 7, the thickness of the ring portion 120a of the snap ring 120 in the axial center C direction is basically the thickness tb, but the opening end portion 136 has a thickness smaller than the thickness tb. ta. That is, the thickness of the snap ring 120 in the direction of the axis C is thinner over the entire radial width of the opening end portion 136 than the other portions. Further, the thickness of the snap ring 120 in the direction of the axis C is smooth from the thickness tb to ta as shown by the hatched portion D in FIG. It is changing and thinning continuously. Since the operation portion 120b of the snap ring 120 does not contact the inner peripheral groove 128 of the transfer case 42, there is no particular limitation on the thickness thereof, but in this embodiment, the thickness ta of the ring portion 120a is continuously maintained as it is. The wall thickness is 120b in the direction of the axis C.

Here, it is assumed that the pressing force F _TH (see FIGS. 3 and 4) in the direction of the axis C toward the inside of the transfer case 42 acts on the rear wheel side bearing 112. For example, as shown in FIG. 3, the rear propeller shaft 24 has a structure that can be expanded and contracted, but the rear propeller shaft 24 is subjected to a displacement to shorten its length in the direction of the axis C, and at that time, the inner cylinder When the member 24a and the outer cylinder member 24b do not slide smoothly in the direction of the axis C, the pressing force F _TH is increased from the rear propeller shaft 24 via the rear wheel side companion flange 114. It acts on the rear wheel side bearing 112.

In the transfer 22 of the present embodiment, since the snap ring 120 has a shape whose thickness changes as described above, in the above case, that is, the pressing force F _TH is applied to the rear wheel side bearing 112. When acting, as shown in part E of FIG. 7, the side wall surface 138 of the inner peripheral groove 128 on the side for receiving the pressing force _FTH and the side wall surface 138 at both of the pair of opening end portions 136. The snap ring 120 is connected to the side surface 140 of the snap ring 120 facing each other with a gap CLR in the entire depth direction (arrow DP direction in FIG. 7) of the inner circumferential groove 128. Speaking of the snap ring 120, the thickness of the snap ring 120 in the axial center C direction is such that the side surface 140 receives the pressing force _FTH with respect to the other portions of the pair of opening end portions 136. It is thinned away from the side wall surface 138 on the side. Thus, the transfer case 42 is never receiving the pressing force F _TH directly in the pair of open ends 136, would receive the pressing force F _TH at a portion other than the pair of open end 136. Therefore, stress concentration on the base end of the side wall surface 138 in the pair of open end portions 136 shown as the corner CR in FIG. 7 is suppressed.

Further, the gap CLR generated in the direction of the axis C between the side wall surface 138 and the side surface 140 at the pair of opening end portions 136 is, for example, to avoid stress concentration at the pair of opening end portions 136. It is desirable that the thickness of the snap ring 120 in the axial center C direction is determined so as to be equal to or greater than the circumferential width W1 set experimentally in advance.

In the connection structure of the snap ring 120 of the present embodiment, the thickness of the snap ring 120 in the axial center C direction in order to generate the gap CLR between the side wall surface 138 and the side surface 140 at the opening end 136. However, the groove width Wd in the direction of the axis C of the inner peripheral groove 128 of the transfer case 42 may be changed in order to generate the gap CLR in addition to or instead of this. This will be described with reference to FIG. FIG. 8 is a view for explaining another connecting structure of the snap ring 120 different from that corresponding to FIG. 7 in the portion B shown in FIG. 8 is a view showing one of the pair of open end portions 136 as in FIG. 7, and the other connecting structure is the same as in FIG.

According to the coupling structure of the snap ring 120 shown in FIG. 8, for example, the groove width Wd in the direction of the axis C of the inner circumferential groove 128 is equal to the inner circumferential groove 128 at the opening end portion 136 with respect to other portions. In the entire depth direction (arrow DP direction in FIG. 7). Further, the groove width Wd in the direction of the axis C of the inner peripheral groove 128 changes smoothly with respect to other portions at the opening end portion 136 and continuously increases. As described above, since the groove width Wd is wide at the opening end 136, the side wall surface 138 and the side surface 140 at the opening end 136 are similar to the connection structure of the snap ring 120 shown in FIG. A gap CLR in the axial center C direction can be generated between the two.

This embodiment has the following effects (A1) to (A6). (A1) According to this embodiment, the pressing force F _{TH in the} direction of the axis C (see FIGS. 3 and 4) at the pair of open end portions 136 of the transfer case 42 that is opened in the circumferential direction with the inner peripheral groove 128 being interrupted. 7) acts on the rear wheel side bearing 112, the side wall surface 138 of the inner circumferential groove 128 on the side receiving the pressing force _FTH, and the side wall surface 138, as shown in part E of FIG. The snap ring 120 is connected to the side surface 140 of the snap ring 120 facing each other with a gap CLR in the entire depth direction (arrow DP direction in FIG. 7) of the inner circumferential groove 128. Therefore, the pressing force F _TH does not directly act on the side wall surface 138 at the pair of opening end portions 136 due to the gap CLR. Therefore, stress concentration is relaxed at the open end 136, and the durability of the transfer case 42 can be improved. And the reliability of the connection structure of this snap ring 120 can be improved. In addition, if the connection structure of the snap ring 120 having the gap CLR is provided in at least one of the pair of opening end portions 136, the durability of the transfer case 42 can be improved as compared with a structure without the gap CLR. However, as in this embodiment, by having the gap CLR at both of the pair of opening ends 136, the durability of the transfer case 42 is further improved, and the reliability of the connection structure of the snap ring 120 is improved. Can be improved.

Further, as means for improving the durability of the transfer case 42, for example, an increase in the thickness around the inner peripheral groove 128 or an increase in the corner radius at the bottom of the inner peripheral groove 128 can be considered. In the performance improving means, problems such as an increase in cost, an increase in mass, and interference with other parts inside the transfer 22 are likely to occur. However, the connection structure of the snap ring 120 of this embodiment hardly causes such problems. It is advantageous.

(A2) Also, according to the present embodiment, as shown in FIG. 7, the thickness of the snap ring 120 in the axial center C direction is the full width in the radial direction with respect to the other portions at the opening end 136. Since the snap ring 120 is formed so that the gap CLR is formed, the transfer case 42 does not need to be changed to generate the gap CLR. The durability of 42 can be improved. And since the shape change of the transfer case 42 is not required, the cost can be suppressed and the durability of the transfer case 42 can be improved. In addition, if it is set as the connection structure of the snap ring 120 which has the said clearance gap CLR in one side of said pair of opening edge part 136, in that case, the thickness of the axial center C direction of the snap ring 120 is, for example, It is thinned at one of the pair of open ends 136.

(A3) Further, according to the present embodiment, the thickness of the snap ring 120 in the direction of the axis C is from the thickness tb to ta as shown by the hatched portion D in FIG. Since it changes smoothly with respect to other parts and is continuously thinned, the snap ring 120 avoids or suppresses stress concentration due to a change in the thickness of the snap ring 120 and suppresses a decrease in durability. .

(A4) Further, according to the present embodiment, as shown in FIG. 8, the groove width Wd in the direction of the axis C of the inner circumferential groove 128 is smaller than the inner width of the opening end portion 136 with respect to the other portions. The circumferential direction of the circumferential groove 128 may be widened in the entire depth direction (arrow DP direction in FIG. 7), and if so, the gap CLR is formed in the shape of the inner circumferential groove 128 at the opening end 136. With this configuration, the durability of the transfer case 42 can be improved without requiring a change in the shape of the snap ring 120 for generating the gap CLR. In addition, if it is set as the connection structure of the snap ring 120 which has the said clearance gap CLR in one of the said pair of opening edge parts 136, in that case, for example, the groove width Wd of the said inner peripheral groove | channel 128 in the axial center C direction Is widened at one of the pair of open ends 136.

(A5) Also, according to the present embodiment, as shown in FIG. 8, the groove width Wd in the direction of the axis C of the inner circumferential groove 128 is smoother than the other portions at the opening end 136. If this is done, the transfer case 42 can avoid or suppress stress concentration caused by the change in the groove width Wd at the opening end 136. Thus, a decrease in durability is suppressed.

(A6) Also, according to this embodiment, in the transfer 22, when the pressing force F _{TH in the} direction of the axis C acts on the rear wheel side bearing 112, the pair of open end portions 136 of the transfer case 42 In both cases, as shown in part E of FIG. 7, the snap ring 120 is connected with the gap CLR between the side wall surface 138 of the inner circumferential groove 128 and the side surface 140 of the snap ring 120. Therefore, the durability of the transfer 22 can be improved against the pressing force F _TH applied to the first output shaft 48.

As mentioned above, although the Example of this invention was described in detail based on drawing, this is an embodiment to the last, and this invention is implemented in the aspect which added various change and improvement based on the knowledge of those skilled in the art. Can do.

For example, in the above-described embodiment, the material of the transfer case 42 is not particularly limited. For example, the transfer case 42 is made of aluminum die cast.

In the above-described embodiment, the method for forming the snap ring 120 is not particularly limited. For example, the snap ring 120 is formed by punching. Although the snap ring 120 has a pair of thin portions, the thin portions may be formed simultaneously with the punching process for punching the outer shape, or the thin portions may be formed in a process different from the punching process for the outer shape. Good. Further, the snap ring 120 may be formed by cutting.

Further, in the above-described embodiment, the processing method of the inner peripheral groove 128 of the transfer case 42 is not particularly limited. For example, the inner peripheral groove 128 may be formed by a die-cast mold or formed by cutting. Also good.

Further, in FIG. 7 of the above-described embodiment, one side surface 140 of the pair of side surfaces of the snap ring 120 orthogonal to the axis C forms a continuous curved surface, and the thickness of the snap ring 120 is the opening end. The portion 136 is thinner than the other portions over the entire width in the radial direction, but both of the pair of side surfaces form a continuous curved surface, and the thickness of the snap ring 120 is the opening end thereof. In 136, it may be thin with respect to the other parts over the entire radial width. The same applies to the groove width Wd of the inner circumferential groove 128 shown in FIG.

Claims

For a fixing member having a fitting hole centered on one axis and an inner circumferential groove provided around the one axis on the inner circumferential surface of the fitting hole, the outer circumferential groove facing the inner circumferential groove is arranged on the outer circumferential surface. A connecting structure of a vehicle snap ring for fixing a fitting member fitted in the fitting hole in the uniaxial direction by a snap ring fitted in the inner circumferential groove and the outer circumferential groove,
In at least one of a pair of opening end portions of the fixing member, the annular inner circumferential groove is cut off at a notch portion in which a part around the fitting hole of the fixing member is cut out, and the fitting member is opened in the circumferential direction. When a pressing force in the uniaxial direction is applied to a member, between the side wall surface of the inner circumferential groove on the side receiving the pressing force and the side surface of the snap ring facing the side wall surface, A connecting structure for a vehicle snap ring, characterized in that a gap is provided over the entire depth direction of the inner circumferential groove.
The connecting structure for a snap ring for a vehicle according to claim 1, wherein a thickness of the snap ring in the uniaxial direction is thinner than other portions at the opening end.
The connecting structure for a snap ring for a vehicle according to claim 2, wherein the thickness of the snap ring in the uniaxial direction is continuously thinner than the other portions at the opening end.
4. The connection of the snap ring for a vehicle according to claim 1, wherein the groove width in the uniaxial direction of the inner peripheral groove is wider than the other portion at the opening end portion. Construction.
5. The vehicular snap ring connection structure according to claim 4, wherein the groove width in the uniaxial direction of the inner circumferential groove is continuously wide at the opening end portion with respect to the other portions. .
The fixing member is a transfer case that distributes the driving force of the vehicle to a plurality of driving wheels,
The vehicle according to any one of claims 1 to 5, wherein the fitting member is an output shaft bearing that supports the output shaft of the transfer so as to be rotatable about the one axis with respect to the fixed member. Snap ring connection structure.