JP2020029228A - Connection structure of power transmission device of vehicle - Google Patents

Abstract

To provide a connection structure between a propeller shaft of a vehicle and a viscous coupling, capable of suppressing rotation vibration caused by misalignment of the propeller shaft.SOLUTION: In a connection structure between a propeller shaft 6 of a vehicle 1 and a viscous coupling 7 for transmitting a part of rotational power outputted from an engine (driving source) 2, selectively to right and left rear wheels (driving wheels) WR through at least the propeller shaft 6 and the viscous coupling 7 connected thereto through a constant velocity joint 10, a constitution is adopted for integrating a yoke (partial rotary part) 12 of the constant velocity joint 10 with a case 14 of the viscous coupling 7 by integral molding.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a connection structure for connecting a propeller shaft and a torque transmission device such as a viscous coupling in a vehicle power transmission device.

  2. Description of the Related Art Conventionally, in a four-wheel drive vehicle (4WD vehicle), in a power transmission device that transmits rotational power output from a drive source such as an engine to a main drive wheel and an auxiliary drive wheel, for example, as shown in Patent Document 1, a propeller A viscous coupling (torque transmission device) is connected to the shaft via a constant velocity joint.

  In such a four-wheel drive vehicle, the rotational speed difference between the main drive wheel and the auxiliary drive wheel becomes the input differential rotation speed for the viscous coupling, and if necessary, a part of the rotational power is transmitted to the auxiliary drive wheel by the viscous coupling. And the main drive wheel and the sub drive wheel are both rotationally driven. Specifically, for example, in a front-wheel drive vehicle (FF vehicle) in which an engine and a transmission are arranged on the front side of the vehicle, the front wheel is a main drive wheel, and the rear wheel is an auxiliary drive wheel, the vehicle has low friction resistance (low When the driver depresses the accelerator pedal while traveling on a road surface having a (coefficient of friction), first, the driving torque is transmitted to the front wheels. When the front wheels idle beyond the grip limit of the road surface, the differential rotation is input to the viscous coupling, and the driving torque is transmitted to the rear wheels.

JP 2014-069658 A

  By the way, the propeller shaft is usually balanced as a single item at the time of manufacture. Also, the balance of the viscous coupling may be performed as a single item. The connection between the propeller shaft and the viscous coupling is performed by attaching a constant velocity joint provided on the propeller shaft to the viscous coupling by fastening a bolt or the like at the time of assembly. In this case, the positioning of the constant velocity joint and the viscous coupling is performed by spigot fitting.

  The propeller shaft is a single piece and is balanced by a balance machine. When the propeller shaft is fastened to the viscous coupling, the propeller shaft positions the constant velocity joint, which is a part of the propeller shaft, and the viscous coupling. In the inlay fitting, play of the fitting tolerance occurs. For this reason, there is a problem that a misalignment occurs in the propeller shaft assembled in the actual vehicle, and the misalignment occurs due to the misalignment, which may be a source of vibration of the vehicle body.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a power transmission device for a vehicle in which a propeller shaft and a torque transmission device such as a viscous coupling capable of suppressing rotational vibration caused by misalignment of a propeller shaft. It is to provide a connection structure.

  In order to achieve the above-mentioned object, the present invention provides a method in which at least a part of rotational power output from a drive source (2) is at least partially connected to a propeller shaft (6) and a torque coupled thereto via a constant velocity joint (10). A power transmission device for a vehicle (1) for selectively transmitting to right and left drive wheels (WR) via a transmission device (a viscous coupling 7 in an embodiment to be described later), wherein the constant velocity joint (10) And a case (14) of the torque transmitting device (7) and a part of the rotating part (12) are integrated by integral molding.

  For example, the constant velocity joint (10) is configured by connecting a yoke (11) on the propeller shaft (6) side and a yoke (12) on the torque transmission device (7) side with a cross pin (13). In the case of a cardan type constant velocity joint, the yoke (12) on the side of the torque transmitting device (7) and the case (14) of the torque transmitting device (7) may be integrated by integral molding.

  Further, the constant velocity joint (10) is provided with a roller (53) rotatably supported on a spider shaft (52) provided on the propeller shaft (6) side by an outer race on the torque transmission device (7) side. In the case of a tri-board type constant velocity joint (50) configured to be slidably fitted in a guide groove formed on the inner periphery of the (54), the outer race (54) and the torque transmitting device (7) You may make it integrate with the case (14) by integral molding.

  According to the present invention, since the misalignment does not occur when the propeller shaft is assembled, the rotational vibration of the propeller shaft due to the misalignment can be suppressed.

1 is a plan view schematically showing a power transmission device for a four-wheel drive vehicle including a connection structure according to Embodiment 1 of the present invention. FIG. 2 is an enlarged plan sectional view showing an A portion of FIG. 1. FIG. 4 is a schematic side view showing balancing of a propeller shaft. FIG. 9 is a partial plan sectional view showing a connection structure according to a second embodiment of the present invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<First Embodiment>
FIG. 1 is a plan view schematically showing a power transmission device of a four-wheel drive vehicle provided with a connection structure according to Embodiment 1 of the present invention, and FIG. .

  The four-wheel drive vehicle (hereinafter simply referred to as “vehicle”) 1 shown in FIG. 1 employs an FF system (an engine-front-front-wheel drive system), and is driven at the front (the left end in FIG. 1). An engine 2 as a power source, a transmission (transmission) 3 and a front differential device (differential device) 4 are arranged. Front drive shafts 5 extend outward (up and down in FIG. 1) from the left and right sides of the front differential device 4, respectively, and the front end of each front drive shaft 5 is a front wheel serving as a main drive wheel. Each WF is attached.

  A propeller shaft 6 extends linearly from the transmission 3 toward the rear of the vehicle (to the right in FIG. 1) at the center in the vehicle width direction. At the rear end of the propeller shaft 6, a viscous coupling (torque transmission device) 7 and a rear differential device 8 are sequentially connected, and a rear drive shaft 9 is outwardly provided from the left and right sides of the rear differential device 8 (FIG. 1). In the up and down direction. Rear wheels WR, which are auxiliary driving wheels, are attached to the outer end of each rear drive shaft 9.

  Incidentally, the rear end of the propeller shaft 6 and the viscous coupling 7 are connected by a constant velocity joint (universal joint) 10, as shown in FIG. In the present embodiment, a cardan type constant velocity joint is used as the constant velocity joint 10, and the cardan type constant velocity joint 10 has one yoke 11 (propeller shaft 6 side) and the other (viscus coupling side) yoke. 12 are connected by a cross-shaped spider shaft 13.

  Here, the propeller shaft 6 is a hollow pipe member, and the yoke 11 on one side (propeller shaft 6) of the cardan-type constant velocity joint 10 has a solid shaft portion 11a formed by a rear end portion of the propeller shaft 6. , And is fixed concentrically to the rear end of the propeller shaft 6 by welding the periphery. Although not shown, the front end of the propeller shaft 6 and the output shaft of the transmission 3 are also connected by a similar Cardan-type constant velocity joint.

  As shown in FIG. 2, the viscous coupling 7 includes a bottomed cylindrical case 14 that rotates integrally with the propeller shaft 6, and a solid pinion shaft 15 rotates around the axial center of the case 14. Inserted as possible. The opening of the case 14 is closed by a ring-shaped cover member 16, and a cylindrical sleeve 17 is inserted through the outer periphery of a portion of the pinion shaft 15 facing the inside of the case 14. The pinion shaft 15 and the pinion shaft 15 are connected by spline fitting so as to rotate integrally. Here, both ends in the axial direction of the sleeve 17 are rotatably supported by a case 14 and a cover member 16 by bearings (ball bearings) 18 and bearings (needle bearings) 19. Are sealed by a seal ring 20 such as an O-ring. At the center of the bottom of the case 14 (the wall on the side of the propeller shaft 6 and the yoke 11), an opening 14b for inserting a tool when fastening the nut 35 attached to the tip of the pinion shaft 15 is formed. ing.

  Therefore, an operating chamber S is defined in the case 14 by the cover member 16 and the sleeve 17, and a plurality of ring-shaped outer plates 21 and inner plates 22 are formed in the operating chamber S along the axial direction. Are housed in a state of being alternately stacked. Here, the outer plate 21 has its outer peripheral portion engaged with the inner peripheral surface of the case 14 so as not to rotate relatively, and the inner plate 22 has its inner peripheral portion engaged with the outer peripheral surface of the sleeve 17 so as not to rotate relatively. I agree. The inside of the working chamber S is filled with a viscous fluid having a high viscosity such as silicone oil.

  In the present embodiment, the yoke 12 on the viscous coupling 7 side of the cardan type constant velocity joint 10 and the case 14 of the viscous coupling 7 are integrated by integral molding. For this reason, it is not necessary to fix the yoke 12 to the case 14 by bolts or the like in a state where the yoke 12 is positioned with respect to the case 14 by the spigot fitting, and a misalignment occurs between the two due to the fitting tolerance of the spigot fitting. Nothing.

  Next, the configuration of the rear differential device 8 will be described below with reference to FIG.

  The rear differential device 8 includes a spherical shell-shaped differential case 24 rotatable around the axis C1 of the left and right rear drive shafts 9 in the housing 23. Here, the left and right of the differential case 24 are rotatably supported by the housing 23 by bearings (Bory bearings) 25, and the inner ends of the left and right rear drive shafts 9 are rotatably inserted into the left and right, respectively. are doing. A ring gear 26 that is rotatable about the axis C1 of the rear drive shaft 9 together with the differential case 24 is attached to the outer periphery of the differential case 24.

  The pinion shaft 15 extends through the housing 23 to the rear of the vehicle body (rightward in FIG. 2), and is rotatably supported by the housing 23 by two front and rear bearings (taper roller bearings) 27. The bevel gear 15 a formed integrally with the rear end of the pinion shaft 15 meshes with the ring gear 26.

  A pinion shaft 28 is inserted and fixed in the center of the differential case 24 in the direction of the axis C2 (the left-right direction in FIG. 2) orthogonal to the axis C1, and is rotated inside the differential case 24 by the pinion shaft 28. A pair of pinion gears 29 supported in a rotatable manner and a pair of side gears 30 meshed with the pinion gears 29 and rotatably supported around the axis C1 are accommodated therein. Here, the pair of pinion gears 29 are disposed in the front and rear (left and right in FIG. 2) in the differential case 24, and the pair of side gears 30 are disposed on the left and right (up and down in FIG. 2) with the pinion shaft 28 interposed therebetween. ing.

  The side gears 30 are respectively connected to inner ends of the pair of left and right rear drive shafts 9 facing the inside of the differential case 24 by spline fitting, and the side gears 30 rotate together with the respective rear drive shafts 9.

  In the vehicle 1 shown in FIG. 1 including the power transmission device configured as described above, when the engine 2 is started, the rotational power (torque) output from the engine 2 is transmitted through the transmission 3 to the front differential device 4. Is transmitted to. Since a part of the rotational power transmitted to the front differential device 4 is transmitted to the left and right front drive shafts 5, the left and right front wheels WF attached to the front drive shafts 5 are rotationally driven, respectively. The vehicle 1 runs by the rotation of these front wheels WF.

  Another part of the rotational power transmitted to the front differential device 4 is transmitted to the viscous coupling 7 via the propeller shaft 6 and the cardan-type constant velocity joint 10. In the viscous coupling 7, the case 14 and the yoke 12 integrated therewith rotate with the propeller shaft 6.

  While the vehicle 1 is running, torque input from the rear wheels WR is transmitted to the pinion shaft 15 via the rear differential device 8, and the pinion shaft 15 rotates together with the sleeve 17 of the viscous coupling 7. Here, when the rotation speed of the case 14 of the viscous coupling 7 is equal to the rotation speed of the pinion shaft 15 (sleeve 17), the rotation speed of the outer plate 21 engaging with the case 14 and the inner plate 22 engaging with the sleeve 17 are set. And no relative rotation occurs between the two, so that no shearing force is generated in the viscous fluid in the working chamber S. Therefore, no torque is transmitted between the outer plate 21 and the inner plate 22, and the torque of the propeller shaft 6 is not transmitted to the left and right rear wheels WR, and the vehicle 1 is driven by only the left and right front wheels WF. Travel (two-wheel drive).

  On the other hand, when the front wheel WF slips and a differential rotation occurs between the case 14 and the pinion shaft 15 of the viscous coupling 7, a differential rotation occurs between the outer plate 21 and the inner plate 22 housed in the case 14. As a result, a shearing force is generated in the viscous fluid in the working chamber S in accordance with the rotation difference. Then, the torque input from the propeller shaft 6 to the viscous coupling 7 is transmitted to the pinion shaft 15 by the shearing force, and the torque is distributed by the rear differential device 8 and transmitted to the left and right rear drive shafts 9. Is done. For this reason, the rear wheels WR attached to the left and right drive shafts 9 are rotationally driven, and the vehicle 1 runs in a four-wheel drive state by rotation of the front wheels WF and the rear wheels WR.

  Here, the operation of the rear differential device 8 will be described.

  As described above, when the pinion shaft 15 rotates, the rotation is transmitted to the differential case 24 via the bevel gear 15a and the ring gear 26 meshing with each other, so that the differential case 24 rotates around the axis C1, and the rear differential In the device 8, the torque is divided into two and transmitted to the left and right rear drive shafts 9, respectively. Then, the rotation of the left and right rear drive shafts 9 is transmitted to the left and right rear wheels WR (see FIG. 1), and the left and right rear wheels WR are rotationally driven.

  In the rear differential device 8, when the vehicle 1 travels straight, the left and right rear drive shafts 9 receive the same resistance from the road surface, so that the pair of pinion gears 29 revolve together with the differential case 24 to form a pair of left and right side gears. The torque is distributed and transmitted to 30. At this time, the pair of pinion gears 29 does not rotate (rotate). On the other hand, at the time of cornering when the vehicle 1 turns, a difference occurs in the resistance received by the left and right rear wheels WR from the road surface (difference in the moving distance of the left and right rear wheels WR), and the pair of pinion gears 29 rotates by themselves. The rotational speed of one side gear 30 is made higher than the rotational speed of the other side gear 30 to distribute and transmit the rotational power to the left and right rear drive shafts 9 while smoothly cornering the vehicle 1.

  In the vehicle 1 having the power transmission system configured as described above, the yoke 12 on one side (the viscous coupling 7 side) of the cardan-type constant velocity joint 10 and the case 14 of the viscous coupling 7 are integrally formed by both. It is not necessary to fix the yoke 12 to the case 14 with bolts or the like in a state where the yoke 12 is positioned with respect to the case 14 by the spigot fitting as in the conventional structure, and the fitting tolerance of the spigot fitting between the two is reduced. There is no accompanying misalignment.

  Therefore, as shown in FIG. 3, if the balance of the propeller shaft 6 is performed by a balance machine (balancer) 40 in a state where the case 14 of the viscous coupling 7 is attached to the propeller shaft 6, at the time of manufacturing. There is no occurrence of misalignment of the propeller shaft 6 that occurs when the propeller shaft 6 that has been individually balanced is assembled. For this reason, the rotational vibration of the propeller shaft 6 assembled in the vehicle 1 is suppressed, and the vibration of the vehicle 1 itself is suppressed to be small, and the riding comfort of the vehicle 1 is enhanced. The balance of the propeller shaft 6 is performed in a state in which the inner peripheral portion 14a on which the bearing 18 serving as a reference of the center of rotation of the case 14 of the viscous coupling 7 attached to the propeller shaft 6 is chucked by the balance machine 40. Will be

<Embodiment 2>
Next, a second embodiment of the present invention will be described below with reference to FIG.

  FIG. 4 is a partial plan sectional view showing a connecting structure according to Embodiment 2 of the present invention. In this figure, the same elements as those shown in FIG. Will not be described again.

  The connection structure according to the present embodiment is characterized in that a tri-board type constant velocity joint 50 is used as a constant velocity joint for connecting the propeller shaft 6 and the viscous coupling 7, and the other configuration is the same as that of the first embodiment. It is the same as that of

  Here, the tri-board type constant velocity joint 50 has a forked spider shaft 52 attached to the front end of a rotating shaft 51 which is inserted and welded to the rear end (the right end in FIG. 4) of the propeller shaft 6. A roller 53 rotatably supported at the tip of 52 is slidably engaged with a guide groove (not shown) formed on the inner peripheral surface of a cylindrical outer race 54.

  In the present embodiment, the outer race 54 of the tri-board type constant velocity joint 50 and the case 14 of the viscous coupling 7 are integrally formed by integrating them. Therefore, also in the present embodiment, by balancing the propeller shaft 6 in a state where the case 14 of the viscous coupling 7 is attached to the propeller shaft 6, as in the first embodiment, the propeller shaft 6 The effect is obtained that the rotational vibration can be kept small.

  Although the embodiments using the cardan type constant velocity joint and the tri-board type constant velocity joint as constant velocity joints have been described above, the present invention relates to a connection structure using a constant velocity joint of any other type. The same can be applied to this. In the above-described embodiment, the viscous coupling is described as an example of the torque transmission device of the present invention. However, the torque transmission device of the present invention includes, for example, a large number of friction plates housed in a case. A friction engagement device such as a multi-plate clutch or another torque transmission device may be used.

  The application of the present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the claims and the technical concept described in the specification and the drawings.

1 four-wheel drive vehicle (vehicle)
2 engine (drive source)
3 Transmission 4 Front differential device 5 Front drive shaft 6 Propeller shaft 7 Viscous coupling (torque transmission device)
Reference Signs List 8 rear differential device 9 rear drive shaft 10 cardan type constant velocity joint 11, 12 yoke of constant velocity joint 13 cross pin of constant velocity joint 14 case of viscous coupling 50 tri-board type constant velocity joint 52 spider shaft of tri-board type constant velocity joint 53 Roller of tri-board type constant velocity joint 54 Outer race of tri-board type constant velocity joint WF Front wheel WR Rear wheel

Claims (4)

In a vehicle power transmission device that selectively transmits at least a part of the rotational power output from a drive source to left and right drive wheels via at least a propeller shaft and a torque transmission device connected thereto via a constant velocity joint. A connection structure for connecting the propeller shaft and the torque transmission device,
A connection structure for a power transmission device for a vehicle, wherein a part of the rotating parts of the constant velocity joint and a case of the torque transmission device are integrated by integral molding. The constant velocity joint is a cardan type constant velocity joint formed by connecting the yoke on the propeller shaft side and the yoke on the torque transmission device side with a cross pin,
The connection structure of a power transmission device for a vehicle according to claim 1, wherein the yoke on the torque transmission device side and a case of the torque transmission device are integrated by integral molding. The constant velocity joint is configured such that a roller rotatably supported by a spider shaft provided on the propeller shaft side is slidably fitted into a guide groove formed on an inner periphery of an outer race on the torque transmission device side. A tri-board type constant velocity joint composed of
The connecting structure of a power transmission device for a vehicle according to claim 1, wherein the outer race and a case of the torque transmission device are integrated by integral molding. The coupling structure for a power transmission device for a vehicle according to any one of claims 1 to 3, wherein the torque transmission device is a viscous coupling.