JPH068050U - Power transmission device for four-wheel drive vehicle - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve the support rigidity of the ring gear with a simple structure. A first casing member 31 formed integrally with a ring gear 34 and rotatably supported by the front differential case 26 so as to surround at least the outer peripheral side of the case main body portion 26a of the front differential case 26, and a radius of the ring gear 34. The first casing member 31 on the inner side in the direction
Is spline-fitted into the spline hole 35 formed in
A second casing member 36 rotatably fitted and supported on the tubular portion 26b of the front differential case 26 is provided.
The second casing member 36 is formed with a casing wall portion 36a located on the inner peripheral side of the spline hole 35, and a rear wheel drive gear 39 which is integrally formed with the casing wall portion 36a and transmits the driving force to the rear differential. did.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a power transmission device for a four-wheel drive vehicle in which a transmission is horizontally arranged in a front portion of a vehicle body.

[0002]

[Prior art]

 In a power transmission device for a four-wheel drive vehicle in which an engine and a transmission are horizontally placed in the front part of the vehicle body as a power transmission device for a four-wheel drive vehicle, a heavy load such as an engine and a transfer device is arranged in the front part of the vehicle body. As a result, the turning characteristics basically have an understeer tendency, but the drive torque to the rear wheels is smaller than the drive torque to the front wheels, so that the understeer tendency is not further promoted. It is known that the driving force from the mission is directly transmitted to the rear wheels via the ring gear and intermittently transmitted to the front wheels via the ring gear and the clutch. Has been. As the power transmission device, Japanese Patent Laid-Open No. 62-68136 provides a ring gear that meshes with an output gear of a transmission, and this ring gear is used for the left end portion of the casing main body portion of the front differential case of the front wheel differential and the casing main body. It is described that a hydraulic clutch is provided between the tubular portion and a ring gear portion extending to the tubular portion side, which is rotatably supported by a tubular portion extending leftward from the above portion via a pair of left and right bearings. Has been done.

[0003]

[Problems to be solved by the device]

 By the way, since a large driving force from the transmission is transmitted to the ring gear, it is desirable to maximize the support rigidity of the ring gear with respect to the front differential case in order to prevent vibration and noise generation and deterioration of durability. The power transmission device described in the above publication has a problem in that it is difficult to set a wide span between the pair of left and right bearings that rotatably support the ring gear in terms of layout, and sufficient support rigidity cannot be obtained. Therefore, it is possible to rotatably support the casing member surrounding the front differential case at both left and right ends of the front differential case, and to provide a ring gear on this casing member. There is a problem that it drops to. An object of the present invention is to provide a power transmission device for a four-wheel drive vehicle that can improve the support rigidity of a ring gear with a simple structure.

[0004]

[Means for Solving the Problems]

 The power transmission device for a four-wheel drive vehicle according to claim 1 includes a ring gear that meshes with an output gear of a transmission laterally arranged in a front portion of the vehicle body, and transmits the driving force from the ring gear to a rear wheel drive system and the ring gear. In a power transmission device of a four-wheel drive vehicle configured to transmit a driving force from a clutch means to a front wheel drive system via a front wheel differential device, the power transmission device is integrally formed with the ring gear and at least in the front differential case. The first casing member is rotatably supported by the front differential case so as to surround the outer peripheral side of the case body, and is spline-fitted into a spline hole formed in the first casing member on the radially inner side of the ring gear. A second casing member rotatably fitted to and supported by a tubular portion of the differential case.

A power transmission device for a four-wheel drive vehicle according to a second aspect is the power transmission device for a four-wheel drive vehicle according to the first aspect, wherein the first casing member is a rear wheel drive system via the ring gear. It is configured to transmit a driving force to. The power transmission device for a four-wheel drive vehicle according to claim 3 is the power transmission device for a four-wheel drive vehicle according to claim 1, wherein the second casing member is positioned on the inner peripheral side of the spline hole. And a rear-wheel drive gear for integrally transmitting the driving force to the rear-wheel drive system. A power transmission device for a four-wheel drive vehicle according to a fourth aspect is the power transmission device for a four-wheel drive vehicle according to the third aspect, wherein the clutch means is interposed between the second casing member and the tubular portion of the front differential case. It is composed of a hydraulic multi-plate clutch provided. A power transmission device for a four-wheel drive vehicle according to a fifth aspect is the power transmission device for a four-wheel drive vehicle according to the third aspect, wherein a viscous coupling is interposed between the second casing member and the tubular portion of the front differential case. It was done.

[0006]

[Action]

 In the power transmission device for a four-wheel drive vehicle according to claim 1, a ring gear that meshes with an output gear of a transmission is rotatably supported by the front differential case so as to surround at least the outer peripheral side of the case main body portion of the front differential case. A second casing which is integrally formed with the first casing member, and which is rotatably fitted to and supported by a cylindrical portion of the front differential case in a spline hole formed in the first casing member radially inside the ring gear. Since the casing members are spline-fitted, the span of the rotational support position of both casing members with respect to the front differential case can be set large, and the input load input from the output gear to the ring gear can be passed through the second casing member. It can be effectively received, and the rigidity of the ring gear support is greatly increased. And above, the generation of vibration and noise between the output gear and the ring gear with effectively prevent possible can improve both durability. Moreover, with a simple structure in which the inner diameter of the spline hole is set to be larger than the outer diameter of the front differential case, it is possible to sufficiently secure the assemblability of both casing members to the front differential case.

In the power transmission device for a four-wheel drive vehicle according to the second aspect, the driving force input from the output gear to the first casing member via the ring gear is transmitted to the rear wheel drive system via the ring gear. The power transmission device for a four-wheel drive vehicle according to claim 3, wherein the second casing member includes a casing wall portion located on the inner peripheral side of the spline hole, and a rear wheel drive integrally formed with the casing wall portion. Gears, the input load input from the output gears to the ring gears is effectively received via the casing wall portion, and the driving force input to the first casing member is the casing wall of the second casing member. It is transmitted to the rear wheel drive system via the section and the rear wheel drive gear.

In the power transmission device for a four-wheel drive vehicle according to a fourth aspect, the clutch means is composed of a hydraulic multi-plate clutch interposed between the second casing member and the tubular portion of the front differential case. Through the hydraulic multi-plate clutch, the distribution of driving force to the rear wheel drive system and the front wheel drive system can be adjusted. In the power transmission device for a four-wheel drive vehicle according to claim 5, since the viscous coupling is provided between the second casing member and the cylindrical portion of the front differential case, the rotation difference between the front and rear wheels can be restricted. It is possible to improve turning performance.

[0009]

[Effect of device]

 As described in detail in the section of the action, the following effects can be obtained. According to the power transmission device for a four-wheel drive vehicle of claim 1, by providing the first casing member and the second casing member, the support rigidity of the ring gear is significantly improved, and vibration between the output gear and the ring gear is increased. -It is possible to effectively prevent the generation of noise, improve the durability of both, and secure sufficient assemblability of both casing members with respect to the front differential case.

According to the power transmission device for a four-wheel drive vehicle of claim 2, the driving force input from the output gear to the first casing member via the ring gear is transmitted to the rear wheel drive system via the ring gear. Therefore, the same effect as that of the first aspect can be obtained. According to the power transmission device for a four-wheel drive vehicle of claim 3, the second casing member includes a casing wall portion located on the inner peripheral side of the spline hole and a rear wheel drive integrally formed with the casing wall portion. The drive force input to the first casing member is transmitted to the rear wheel drive system via the casing wall portion of the second casing member and the rear wheel drive gear. The same effect can be obtained.

According to the power transmission device for a four-wheel drive vehicle of claim 4, the clutch means is composed of a hydraulic multi-plate clutch interposed between the second casing member and the tubular portion of the front differential case. , The driveability can be improved by adjusting the distribution of the driving force to the rear wheel drive system and the front wheel drive system. According to the power transmission device for a four-wheel drive vehicle of claim 5, since the viscous coupling is interposed between the second casing member and the tubular portion of the front differential case, the difference in rotation between the front and rear wheels can be restricted. It is possible to improve turning performance.

[0012]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a power transmission device for a four-wheel drive vehicle. In this embodiment, the front, rear, left and right are defined with reference to the front, rear, left and right of the automobile. FIG. 1 shows an overall schematic structure of a four-wheel drive vehicle according to an embodiment of the present invention. An engine 2 is arranged at a front portion of a vehicle body 1, and a crankshaft 2a of the engine 2 extends in a vehicle width direction. It is mounted on the right side in a horizontal position. A manual transmission 3 is disposed on the left side of the engine 2, and the transmission 3 is mounted horizontally so that an input shaft 6 and an output shaft 7 arranged side by side inside a casing 4 extend in the vehicle width direction. The input shaft 6 is discontinuously connected to the crankshaft 2a via the clutch device 5, and the gear transmission path between the input shaft 6 and the output shaft 7 arranged in parallel is switched to change the gear ratio. Is configured to switch.

On the rear side of the portion of the transmission 3 near the center of the vehicle width, a front axle shaft 8 which is divided into left and right and a transfer output shaft 9 which is arranged in parallel behind the front axle shaft 8 are respectively shifted. The left and right front axle shafts 8 are arranged parallel to the input shaft 6 and the output shaft 7 of the machine 3, and are connected to the left and right front wheels 12 via a constant velocity joint 10 and a drive shaft 11, respectively. The right end of the transfer output shaft 9 is connected to the front end of a propeller shaft 15 extending in the vehicle front-rear direction via a bevel gear mechanism 14 via a universal joint 15a, and the rear end of the propeller shaft 15 is divided into left and right rear parts. It is connected to a rear differential mechanism 17 on the axle shaft 16 via a constant velocity joint 15b.

The rear differential mechanism (hereinafter referred to as the rear differential) 17 includes a differential gear case 19 connected to the propeller shaft 15 via a bevel gear mechanism 18, a pair of pinions 20 supported by a differential gear case 19, and a pinion 20. It is composed of a pair of left and right side gears 21 that mesh with the union 20 and are fixed to the inner ends of the left and right rear axle shafts 16, respectively. The outer ends of the left and right rear axle shafts 16 have a constant velocity joint 22 and a drive shaft 23. It is connected to the left and right rear wheels 24 respectively. A front differential case 26 of a front differential mechanism (hereinafter referred to as front differential) 25 as a differential mechanism between the left and right front wheels 12 is externally fitted onto the left and right front axle shafts 8 as shown in detail in FIG. The front differential case 26 is integrally formed of a hollow substantially spherical case body portion 26a and cylindrical tube portions 26b and 26c extending from the case body portion 26a to the left and right sides, and is formed in the case body portion 26a. Is rotatably attached to the case main body 26a through a pair of side gears 27 coupled to the left and right front axle shafts 8 and a pair of side gears 27 and a pinion shaft 28a arranged at a right angle to the front axle shafts 8a. A pair of supported pinion gears 28 are fitted.

Next, the transfer device 30 that distributes the driving force from the output gear 7 a provided at the shaft end of the output shaft 7 of the transmission 3 to the rear differential 17 and the front differential 25 will be described with reference to FIG. 2. As described above, the first casing member 31 that surrounds the case main body portion 26a of the front differential case 26 and the right cylindrical portion 26c is provided, and the first casing member 31 is a pair of left and right spaced apart by a predetermined distance. A tubular shape that is rotatably supported by the front differential case 26 via a needle bearing 32, is axially positioned via a needle bearing 33, and has a tubular portion 26c fitted on the right portion of the first casing member 31. A part 31a is formed, and a ring gear 34 that meshes with the output gear 7a is formed on the left part of the first casing member 31 so as to project leftward. Inside the ring gear 34 in the radial direction, a spline hole 35 having a diameter larger than the outer diameter of the front differential case 26 is formed. A second casing member 36 surrounding the cylindrical portion 26b is rotatably provided on the left portion of the front differential case 26 via a pair of left and right needle bearings 37, and is axially positioned via a needle bearing 38. A casing wall portion 36a that fits into the spline hole 35 by spline fitting is formed on the right portion of the second casing member 36, and is integrally formed on the left portion of the second casing member 36 near the left end of the transfer output shaft 9. A rear-wheel drive gear 39 that meshes with the gear member 9a is formed.

A clutch mechanism 41 for switching between a four-wheel drive state and a rear wheel drive state is provided between the cylinder portion 26c of the front differential case 26 and the first casing member 31, and the sleeve 40 of the clutch mechanism 41 is connected to the clutch mechanism 41. When it is moved to the four-wheel drive position shown in phantom in FIG. 2 via a fork (not shown), the first casing member 31 and the front differential case 26 are connected to each other via the sleeve 40 so that they cannot rotate relative to each other, and the output gear The driving force input from 7a to the ring gear 34 is transmitted to the front differential 25 through the first casing member 31 and the sleeve 40, and also through the first casing member 31 and the second casing member 36. When the four-wheel drive state in which the front and rear wheels 12 and 24 are transmitted is transmitted to the transfer output shaft 9 and is moved to the rear wheel drive position shown by the solid line, The first casing member 31 and the front differential case 26 can rotate relative to each other, the driving force input from the output gear 7a to the ring gear 32 is not transmitted to the front differential 25, and only the left and right rear wheels 24 are driven. Wheel drive state.

Next, the operation of the power transmission device of the four-wheel drive vehicle will be described. Since the first casing member 31 is rotatably supported by the front differential case 26 via two bare rings 32 arranged with a relatively large span, the first casing member 31 is supported on the front differential case 26. The rigidity can be greatly improved. Moreover, since the casing wall portion 36a is disposed on the inner side of the first ring gear 34, the radial load acting on the ring gear 34 can be effectively received by the casing wall portion 36a, and the first casing member The support rigidity of 31 to the front differential case 26 can be further improved. Therefore, the supporting rigidity of the ring gear 34 formed on the first casing member 31 with respect to the front differential case 26 can be sufficiently increased, and the generation of vibration and noise between the output gear 7a and the ring gear 34 can be effectively prevented. Besides, the durability of both gears 7a and 34 can be greatly improved. Furthermore, with a simple configuration in which the inner diameter of the spline hole 35 formed in the first casing member 31 is set to be larger than the outer diameter of the front differential case 26, the assemblability of both casing members 31 and 36 to the front differential case 26 is improved. Can be secured enough.

Next, a modified example in which the configuration of the transfer device 30 is partially changed will be described. The same members as those in the above-mentioned embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The transfer device 30A of the first modified example will be described. As shown in FIG. 3, an extension portion 45 extending leftward is formed in the tubular portion 26b, and a fluid such as silicone oil is interposed in the extension portion 45. A viscous coupling 46 for transmitting the driving force is provided in an external fitting shape, an inner cylinder 47 of the viscous coupling 46 is spline-fitted to the extension portion 45 so as not to be rotatable relative to each other, and a lid is provided on both left and right ends of the inner cylinder 47. A member 48 is rotatably provided, an outer cylinder 49 is non-rotatably fitted onto both lid members 48, and a silicone oil or the like is placed in a space formed by the both cylinders 47 and 49 and both lid members 48. A fluid is enclosed and a plurality of disc members 50 and 51 are provided. The outer peripheral portion of the odd-numbered disc member 50 from the left is connected to the outer cylinder 49, and the inner periphery of the even-numbered disc member 51 from the left. Is connected to the inner cylinder 47, and when the rear wheels are driven, the driving force of the second casing member 36 is transmitted to the front differential 25 via the viscous coupling 46 due to the viscosity of the fluid filled between the disk members 50 and 51. By transmitting the driving force to the front wheels 12 to some extent, the difference in rotation between the front and rear wheels 12 and 24 is restricted to improve drivability.

The transfer device 30 B of the second modified example will be described. As shown in FIG. 4, the rear wheel drive gear 39 is omitted and the gear member 9 A of the transfer output shaft 9 directly meshes with the ring gear 34. In place of the clutch mechanism 41, a hydraulic multi-plate clutch 55 is provided on the left side of the casing wall portion 36a of the second casing member 36B. Explaining the hydraulic multi-plate clutch 55, a supporting cylinder portion 56 extending leftward is formed on the casing wall portion 36a, and an annular casing 57 having a substantially U-shaped cross section for covering the supporting cylinder portion 56 is formed on the cylinder portion 26b. It is fixed so as not to rotate relatively, and a plurality of clutch plates 58, 59 are provided between the outer peripheral wall of the casing 57 and the support tubular portion 56. The odd numbered clutch plates 58 from the left are spline-fitted to the support tubular portion 56. The even-numbered clutch plates 59 from the left side are spline-fitted to the outer peripheral wall of the casing 57, and an annular piston member 60 is oil-tightly slidably mounted in the left portion of the casing 57. Is formed with an operating portion 60a capable of operating the clutch plates 58 and 59 to the right, and is operated between the piston member 60 and the left wall portion of the casing 57. The chamber 61 is formed, and by controlling the hydraulic pressure of the working fluid supplied to the hydraulic oil chamber 61, the fastening force between the clutch plates 58 and 59 is controlled to distribute the driving force to the rear differential 17 and the front differential 25. It is configured to adjust. An electromagnetic clutch or the like may be used instead of the hydraulic multi-plate clutch 55.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a power transmission device for a four-wheel drive vehicle.

FIG. 2 is a cross-sectional view of a transfer device.

FIG. 3 is a cross-sectional view of a transfer device according to a first modification.

FIG. 4 is a cross-sectional view of a transfer device according to a second modification.

[Explanation of symbols]

 3 Transmission 7a Output gear 17 Rear differential 25 Front differential 26 Front differential case 26a Case body 31 First casing member 34 Ring gear 35 Spline hole 36 Second casing member 36a Casing wall 39 Rear wheel drive gear 41 Clutch mechanism 46 Viscos coupling 55 Hydraulic multi-plate clutch

Claims (5)

[Scope of utility model registration request] 1. A ring gear, which meshes with an output gear of a transmission laterally placed in a front portion of a vehicle body, transmits a driving force from the ring gear to a rear wheel drive system, and from the ring gear through a clutch means and a front wheel differential device. In a power transmission device for a four-wheel drive vehicle configured to transmit a driving force to a front wheel drive system, the front differential case is formed integrally with the ring gear and surrounds at least the outer peripheral side of the case main body portion of the front differential case. A rotatably supported first casing member, and a spline fit in a spline hole formed in the first casing member radially inside the ring gear,
A power transmission device for a four-wheel drive vehicle, comprising: a second casing member rotatably fitted to and supported by a tubular portion of the front differential case. 2. The power transmission of a four-wheel drive vehicle according to claim 1, wherein the first casing member is configured to transmit a driving force to a rear wheel drive system via the ring gear. apparatus. 3. The second casing member includes a casing wall portion located on an inner peripheral side of the spline hole, and a rear wheel drive unit formed integrally with the casing wall portion for transmitting a driving force to a rear wheel drive system. The power transmission device for a four-wheel drive vehicle according to claim 1, further comprising a gear for a vehicle. 4. The four-wheel drive vehicle according to claim 3, wherein the clutch means comprises a hydraulic multi-plate clutch interposed between the second casing member and the tubular portion of the front differential case. Power transmission device. 5. The power transmission device for a four-wheel drive vehicle according to claim 3, wherein a viscous coupling is provided between the second casing member and the tubular portion of the front differential case.