JPH0526579U - Transfer - Google Patents

Abstract

(57) [Abstract] [Purpose] A transfer that transfers the driving force of the engine to the front and rear wheels via a friction clutch, and supplies the required amount of lubricating oil to each differential point according to the differential rotation speed. In addition, it is an object of the present invention to prevent energy loss due to excessive refueling and provide a transfer that does not impose an extra burden on the engine when a large engine output is required. The transfer of the present invention comprises a power transmission device that transmits a driving force of an engine to a drive wheel using a friction clutch, and a motor-driven oil pump that supplies oil to each lubrication point including the power transmission device. A wheel speed sensor for front and rear wheels, and a control unit for driving an oil pump by the motor when differential rotation occurs between the front wheel and the rear wheel by receiving wheel speed signals from these sensors. Characterize.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to the transfer of a four-wheel drive (4WD) vehicle.

[0002]

[Prior Art]

 Japanese Patent Application Laid-Open No. 1-226441 discloses a "vehicle drive system clutch control device".

This is a transfer of a 4WD vehicle that distributes the driving force of the engine to the front and rear wheels via a multi-disc clutch, and an oil pump for supplying oil to each lubrication point including the multi-disc clutch. It is driven by the power of the engine.

[0004]

[Problems to be solved by the device]

 In a transfer equipped with a power transmission device that distributes the driving force to the front and rear wheels using a friction clutch, splash oil is sufficient to lubricate parts other than the differential rotating parts such as the friction clutch and differential gear. However, the sliding parts of the differential rotary part and the meshing parts of the gears require forced lubrication of oil by an oil pump, and the location of such differential rotary parts is generally of a multiple structure and does not splash. The hanging oil does not get inside.

In the apparatus disclosed in Japanese Patent Laid-Open No. 1-226441, as described above, oil is supplied to each lubrication point in the transformer by the oil pump. However, with this configuration, the amount of oil supplied fluctuates according to the rotational speed of the transfer.Therefore, the amount of oil is insufficient when the rotation speed is low and the differential rotation is high. Therefore, the output loss of the engine becomes large, and the engine is overloaded when a large engine output is required due to the driving conditions.

In view of this, the present invention provides a transfer that prevents excessive oil supply and energy loss when the required amount of oil is supplied according to the differential rotation speed, and that reduces the load of engine driving force. With the goal.

[0007]

[Means for Solving the Problems]

 The transfer of this invention is a power transmission device that transmits the driving force of the engine to the drive wheels using a friction clutch, a motor-driven oil pump that supplies oil to each lubrication point including this power transmission device, the front wheels and the rear wheels. It is equipped with wheel speed sensors for the wheels and a control unit that receives the wheel speed signals from these sensors and causes the motor to drive the oil pump when differential rotation occurs between the front wheels and the rear wheels. And

[0008]

[Action]

 The control unit receives the wheel speed signals from the front and rear wheel speed sensors to calculate the differential rotation speed between the front and rear wheels, and regardless of the vehicle speed, when the differential rotation speed is high, the motor-driven oil pump outputs the differential rotation speed. Increase the amount of oil supply and decrease the amount of oil supply when the differential speed is low.

In this way, the amount of oil supplied is controlled according to the differential rotation speed, and the excessive supply of oil is prevented. Moreover, since the oil pump is not directly driven by the engine, it does not burden the engine when a large engine output is required.

[0010]

【Example】

 One embodiment will be described with reference to FIGS. FIG. 1 shows this embodiment, and FIG. 4 shows the power system of a 4WD vehicle using this embodiment. Hereinafter, the left and right directions correspond to the vehicle and the left and right directions in FIGS. 1 and 4, and the upper side in FIGS. 1 and 2 corresponds to the front side of the vehicle.

First, the configuration of this power system will be described with reference to FIG.

This power system includes an engine 1, a transmission 3, a transfer 5 (the embodiment of FIG. 1), a propeller shaft 7 on the front wheel side, a front differential 9 (a differential device on the front wheel side), front axles 11, 13 and left and right wheels. Front wheels 15 and 17, rear wheel side propeller shaft 19, rear differential 21 (rear wheel side differential device), rear axles 23 and 25, left and right rear wheels 27 and 29, and the like.

The driving force of the engine 1 is input to the transfer 5 via the transmission 3 and is transmitted to the front differential 9 and the rear differential 21 via the propeller shafts 7 and 19, respectively, to the left and right front wheels 15 and 17 and the rear wheels. It is distributed to 27 and 29.

As shown in FIGS. 1 and 2, the transfer 5 includes a center differential 31 (power transmission device). The center differential 31 includes a planetary gear type differential mechanism 33 and differential limiting means 35, and is housed in a transfer case 37. The differential mechanism 33 includes an internal gear 39, a pinion gear 41, and a sun gear 43 which are meshed in order. The pinion gear 41 is rotatably supported by a pinion shaft 47 via a needle bearing 45, and both ends of the pinion shaft 47 are supported by left and right pinion carriers 49, 51. The pinion carriers 49 and 51 are welded together. The internal gear 39 is formed on a differential case 53 that houses the differential mechanism 33, and the sun gear 43 is formed on a hollow hub 55.

The input shaft 57 of the transfer 5 is connected to the output shaft from the transmission 3, penetrates the hub 55 relatively rotatably, is spline-connected to the hub 59 integrated with the right pinion carrier 51, and is connected to the circlip 61. To prevent it from coming off. The differential case 53 is formed integrally with the output shaft 63 on the rear wheels 27, 29 side. The right end of the input shaft 57 is supported on the output shaft 63 via a needle bearing 65. The output shaft 63 is connected to the propeller shaft 19 side through a splined boss 67 with a flange.

The hub 55 is spline-connected to a hollow sprocket 69 fitted to the input shaft 57 so as to be rotatable relative to each other. The sprocket 69 is connected to another sprocket 73 via a chain 71. Needle bearings 75 and 77 are arranged between the right end of the sprocket 69 and the inner periphery of the left end of the differential case 53 and the outer periphery of the output shaft 57, respectively, and the left end of the sprocket 69 is provided with a bearing 79 to the transfer case 37. Is supported by. The sprocket 73 is supported by the transfer case 37 by bearings 81 and 83, and is connected to the propeller shaft 7 on the front wheel side via a transmission shaft 85 connected by splines. The differential case 53 and the output shaft 63 are supported by the transfer case 37 via bearings 87 and 89.

Therefore, the driving force of the engine 1 is input to the pinion carrier 51 from the input shaft 57, transmitted from the internal gear 39 to the rear wheels 27 and 29 via the output shaft 63, and the sun gear 43 to the sprocket 69 to the chain. It is transmitted to the front wheels 15 and 17 side via 71 and the sprocket 73. At this time, if a driving resistance difference occurs between the front and rear wheels, the driving force of the engine 1 is differentially distributed to the front and rear sides due to the rotation and revolution of the pinion gear 41.

A multi-plate type main clutch 91 is arranged between the internal gear 39 and the sun gear 43 to connect them. A pressing member 93 of the main clutch 91 is engaged with the sun gear 43 so as to be movable in the axial direction. A ball cam 99 is interposed between the pressing member 93 and a cam ring 95 arranged on the left side of the pressing member 93 via a ball 97. Is formed.

Between the cam ring 95 and the internal gear 39, a multi-plate type pilot clutch 101 that connects them is arranged. An armature 103 is arranged on the right side of the pilot clutch 101 so as to be movable in the axial direction, and a retaining ring 105 that prevents contact between the armature 103 and the pressing member 93 is attached to the inner periphery of the differential case 53. A bearing 107 and a washer 109 that receive the reaction force of the cam 99 are arranged between the differential case 53 and the cam ring 95.

On the left side of the differential case 53, a ring-shaped electromagnet 111 is fixed to the transfer case 35 with bolts 113. When the armature 103 is attracted by the electromagnet 111, the pilot clutch 101 is engaged and the cam ring 95 is connected to the differential case 53 side. When differential rotation occurs in the differential mechanism 33 in this state, the differential torque between the internal gear 39 and the sun gear 43 is input to the cam 99, and the generated cam thrust force engages the main clutch 91 via the pressing member 93. To be done.

In this way, the differential force of the differential mechanism 33 is limited by the engagement force between the pilot clutch 101 and the main clutch 91. If the engaging force of each clutch 91, 101 is sufficiently large, the differential of the differential mechanism 33 (between the front and rear wheels) is locked, and if the engaging force of the pilot clutch 101 is controlled, the respective clutches 91, 101 will slide appropriately. The difference between the front and rear wheels is allowed, and when the pilot clutch 101 is released, the main clutch 91 is also released and the differential becomes free. The main clutch 91, the pilot clutch 101, the electromagnet 111, etc. constitute a differential limiting means.

As shown in FIG. 3, an oil sump 115 is provided below the transfer case 37 by the enclosed oil. As shown in FIG. 1, seals 117, 119 and 121 for preventing oil leakage to the outside are arranged between the input shaft 57, the output shaft 63 and the transmission shaft 85 with respect to the transfer case 37.

The meshing parts and bearings 81 and 83 between the sprocket 73 and the chain 71 are lubricated by the oil in the oil sump 115, and the meshing parts and bearings between the sprocket 69 and the chain 71 by the oil lifted up by the chain 71. 75 and 79 are lubricated.

As shown in FIG. 1, an internal gear type gear pump 123 (oil pump) is arranged inside the transfer case 37. A pump casing sealed with an O-ring 127 is formed between the side plate 125 and the recess of the transfer casing 35, and a drive gear 129 and a driven gear 131 which are meshed with each other are housed in the casing to accommodate a gear pump. It constitutes 123. The drive gear 129 is rotationally driven by a motor 133 attached to the outside of the transfer case 37 via a drive shaft 135.

The gear pump 123 sucks oil from the oil sump 115 through the oil pipe 137 and discharges oil from the oil passage 139 formed in the transfer case 37. A ring 141 is press-fitted on the outlet side of the oil passage 139 of the transfer case 37, and a radial oil passage 143 communicating with the oil passage 139 and a circumferential groove 145 are formed in the ring 141. O-rings 147 and 147 for preventing oil leakage are arranged between the ring 141 and the output shaft 63.

The output shaft 63 is provided with radial and axial oil passages 149 and 151 communicating with the circumferential groove 145, and a radial oil passage 153 communicating with the oil passage 151. The input shaft 57 is provided with an axial oil passage 155 communicating with the oil passage 151 of the output shaft 63 and radial oil passages 157, 159, 161, 163, 165 communicating with the oil passage 155. Further, the differential case 53 is provided with an oblique oil passage 167.

Oil from the oil pump 123 passes through the oil passage 143 of the ring 141, the circumferential groove 145, and the oil passage 149 of the output shaft 63, and then flows into the oil passages 151 and 155 of the output shaft 63 and the input shaft 57. Is supplied from the oil passage 157 to the needle bearing 77, is supplied from the oil passage 159 to the bearing 107, the needle bearing 75, the ball cam 99, the pilot clutch 101, and the like, and is provided from the oil passage 161 to the main clutch 91 and the pressing member 93. The oil is supplied to the pilot clutch 101 through the oil passage 169, is supplied to the gear meshing portion of the differential mechanism 33 and the needle bearing 45 from the oil passage 163, and after lubricating each portion, through the through hole 171 provided in the differential case 53 to the outside. It is discharged.

Further, the oil from the oil passage 165 is supplied to the needle bearing 65, further guided to the outside of the differential case 53 through the oil passage 167 and supplied to the bearing 87 to lubricate each part. Further, the oil is supplied from the oil passage 153 of the output shaft 63 to the bearing 89. The oil discharged to the outside of the differential case 53 returns to the oil sump 115 through the gap with the transfer case 37.

In this way, the differential parts and the like which are contained in the differential case 53 and are difficult to refuel are forcibly lubricated to perform sufficient lubrication, and seizure and the like are prevented.

As shown in FIG. 4, front wheel 15, 17 and rear wheel 27, 29 of this vehicle are equipped with wheel speed sensors 173, 175, 177, 179, respectively, and send a wheel speed signal to the control unit 181. .. The control unit 181 calculates the presence / absence of differential rotation between the front and rear wheels from these signals, and when differential rotation occurs, it sends an exciting current 183 to the electromagnet 111 according to the road surface conditions and steering conditions at that time, and differential In addition to limiting the differential of the mechanism 33, the drive current 185 is sent to the motor 133 to drive the gear pump 123, and the above-mentioned forced lubrication is performed.

The gear pump 123 is driven only when a differential rotation occurs, and the discharge amount of the gear pump 123 is adjusted according to the differential rotation speed to obtain a necessary oil amount and prevent the oil amount from becoming excessive. To be controlled.

Therefore, seizure at each lubrication point is prevented, and the power of the battery is not wasted. Further, since the gear pump 123 is not directly driven by the driving force of the engine, it does not burden the engine when a large engine output is required.

The transfer 5 is thus constructed.

In the vehicle shown in FIG. 4, when one of the front and rear wheels spins on a bad road or the like, driving force is sent to the other wheel through the center differential 31 under the control of the control unit 181 to maintain high running performance. Be done. Further, if the differential limiting force of the center differential 31 is moderately loosened to allow the differential between the front and rear wheels, smooth and stable turning can be performed, and a tight corner braking phenomenon at the time of garage parking can be prevented.

The present invention can be applied not only to the transfer provided with the differential mechanism as in the embodiment but also to the one for transmitting the driving force to the front wheels or the rear wheels via the friction clutch as in each conventional example. ..

[0036]

[Effect of the device]

 The transfer of the present invention is configured so that the differential portion contained in the casing is forcibly lubricated by the motor-driven oil pump and the discharge amount of the oil pump is controlled according to the degree of differential, so that the lubrication is difficult. Is sufficiently lubricated and loss of engine output is prevented.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment.

FIG. 2 is a partially enlarged view of FIG.

3 is a partial cross-sectional view taken along arrow A in FIG.

FIG. 4 is a skeleton mechanism diagram showing a power system of a vehicle using the embodiment of FIG.

[Explanation of symbols]

 5 Transfer 31 Center differential (power transmission device) 33 Differential mechanism 91 Main clutch (friction clutch) 101 Pilot clutch (friction clutch) 123 Gear pump (oil pump) 133 Motor 173, 175, 177, 179 Wheel speed sensor 181 Control unit

Claims (1)

[Scope of utility model registration request] 1. A power transmission device for transmitting a driving force of an engine to a drive wheel by using a friction clutch, a motor-driven oil pump for supplying oil to each lubricating portion including the power transmission device, a front wheel and a rear wheel. And a control unit for driving the oil pump by the motor when differential rotation occurs between the front wheels and the rear wheels when receiving wheel speed signals from these sensors. .