JP6981908B2 - Transfer of all-wheel drive vehicle - Google Patents

Description

The present invention relates to a transfer of an all-wheel drive vehicle, and more particularly to a transfer of an all-wheel drive vehicle having a multi-plate clutch.

Traditionally, all-wheel drive (AWD: All Wheel Drive) vehicles (or four-wheel drive) have excellent running performance on steep slopes, rough roads with many irregularities, and slippery roads (for example, snowy roads and muddy roads). 4WD) vehicles) have been widely put into practical use. The all-wheel drive vehicle has, for example, a main drive wheel directly connected to the engine and an auxiliary drive wheel connected to the engine via a transfer clutch, and the fastening force of the transfer clutch can be adjusted to the road surface condition, running condition, etc. There is a configuration in which the driving force distribution to the sub-driving wheel side is adjusted by controlling according to the situation, and the two-wheel drive and the all-wheel drive are switched.

Here, in Patent Document 1, when the traveling mode is not the fuel efficiency appeal mode, the fastening force of the transfer clutch (wet multi-plate clutch) is controlled to optimally control the driving force distribution of the front and rear wheels according to the motion state of the vehicle. While performing normal AWD control, in the fuel efficiency appeal mode, it is checked whether slip is detected, and if slip is not detected, the transfer clutch is opened and the driving force to the front wheels is 100. The front-wheel drive is controlled to be%, and if slip is detected, the transfer clutch is controlled to the engaged state to execute standby AWD control, and the driving force distribution of the all-wheel drive vehicle that eliminates the slip at an early stage. The control device is disclosed.

Japanese Unexamined Patent Publication No. 2012-116433

According to the driving force distribution control device of the all-wheel drive vehicle disclosed in Patent Document 1 described above, the effect of the fuel consumption appeal mode can be further improved. However, in the above-described configuration, when the transfer clutch (wet multi-plate clutch) is released, the friction torque due to the rotation of the transfer clutch, that is, the drag torque (drag torque) is generated. Therefore, the improvement of the fuel consumption rate (hereinafter referred to as "fuel efficiency") may be hindered. On the other hand, in order to solve such a problem, for example, if an electric actuator, an electronically controlled coupling, or the like is used in place of / or in addition to the transfer clutch (wet multi-plate clutch), the cost increases.

The present invention has been made to solve the above problems, and in the transfer of an all-wheel drive (AWD) vehicle having a multi-plate clutch, the drag torque at the time of clutch release is eliminated while suppressing the increase in cost. The purpose is to provide a transfer for all-wheel drive vehicles that can improve fuel efficiency.

The transfer of the all-wheel drive vehicle according to the present invention has a multi-plate clutch, a transfer clutch that adjusts the torque input from the transmission according to the supplied hydraulic pressure and outputs it to the auxiliary drive wheel side. A first shaft whose one end is connected to the output side of the transfer clutch, a second shaft which is provided coaxially with the first shaft and has a spline formed at one end, a first shaft and a second shaft. Controls the hydraulic pressure supplied to the transfer clutch and the disconnection mechanism, as well as the disconnection / disconnection mechanism that interrupts the connection between the first shaft and the second shaft according to the hydraulic pressure supplied between the shafts. The hydraulic pressure control means is provided, and the disconnection mechanism is formed with a spline that can be fitted with the spline formed on the second shaft, and can rotate integrally with the first shaft, depending on the hydraulic pressure supplied. , The first shaft and the sleeve provided so as to be slidable in the axial direction of the second shaft, and the hydraulic pressure control means controls the hydraulic pressure so as to release the disconnection / disconnection mechanism when the transfer clutch is released. It is characterized by doing.

According to the transfer of the all-wheel drive vehicle according to the present invention, when the transfer clutch is released, the hydraulic pressure is controlled so that the sleeve is slid in the axial direction and the disconnection / disconnection mechanism is released. Therefore, when the transfer clutch (multi-plate clutch) is released, the disconnection / disconnection mechanism is released, and the first shaft and the second shaft (that is, the transfer clutch and the drive system on the auxiliary drive wheel side) are disconnected. As a result, the drag torque of the transfer clutch is eliminated. Therefore, fuel efficiency can be improved. On the other hand, a relatively simple configuration, that is, the above-mentioned disconnection mechanism can be realized at a relatively low cost. As a result, it is possible to eliminate the drag torque when the clutch is released and improve the fuel efficiency while suppressing the increase in cost.

In the transfer of the all-wheel drive vehicle according to the present invention, a spline is formed at the other end of the first shaft, and the disconnection mechanism is a spline that is always spline-fitted with the spline formed on the first shaft. It is preferable to have.

By doing so, the disconnection mechanism (sleeve) can be rotated integrally with the first shaft and can be slidable in the axial direction of the first shaft and the second shaft.

In the transfer of the all-wheel drive vehicle according to the present invention, the hydraulic pressure control means hydraulic pressure through a common hydraulic circuit that communicates with an oil chamber that applies hydraulic pressure to the transfer clutch and an oil chamber that applies hydraulic pressure to the disconnection / disconnection mechanism. It is preferable that the transfer clutch is engaged and the disconnection / disconnection mechanism is engaged by supplying the hydraulic pressure, while the transfer clutch is released and the engagement / disconnection mechanism is released by discharging the hydraulic pressure.

By doing so, it is possible to control the engagement / release of the transfer clutch and the disconnection / disconnection mechanism by using a common hydraulic circuit and a common hydraulic pressure. That is, it is not necessary to newly add a dedicated hydraulic circuit (hydraulic pipe), a solenoid valve for hydraulic control, or the like, and it is possible to suppress an increase in cost.

In the transfer of the all-wheel drive vehicle according to the present invention, it is preferable that a synchro mechanism for synchronizing the rotations of the sleeve and the spline formed on the second shaft at the time of engagement is provided.

By doing so, even if the rotation speeds of the sleeve (connecting mechanism) and the spline (second shaft) are different when the sleeve and the spline formed on the second shaft are engaged, the rotation speed becomes smoother. , The sleeve and the spline can be engaged, i.e., the disconnection mechanism can be fastened.

In the transfer of the all-wheel drive vehicle according to the present invention, when hydraulic pressure is supplied and the transfer clutch and the disconnection / disconnection mechanism are engaged, it is preferable that the transfer clutch is engaged after the synchro mechanism is engaged. ..

In this way, when the synchro mechanism is engaged (the disconnection / disconnection mechanism is engaged), the transfer clutch is not yet engaged (that is, the transmission or the like is not engaged), so that the inertia is small. Therefore, the inertia can be easily absorbed (that is, the insufficient torque capacity of the synchro mechanism can be avoided).

In the transfer of the all-wheel drive vehicle according to the present invention, when the hydraulic pressure is discharged and the transfer clutch and the disengagement mechanism are released, it is preferable that the transfer clutch is released and then the disengagement mechanism is released. ..

By doing so, when the disconnection / disconnection mechanism is released, the transfer clutch is already released and the input torque from the transmission side is lost, so that the sleeve can be easily pulled out (that is, the disconnection / disconnection mechanism is released). can do.

The transfer of the all-wheel drive vehicle according to the present invention applies a first return spring that applies an urging force to the transfer clutch in the direction of releasing the transfer clutch, and an urging force to the disconnection mechanism in the direction of releasing the disconnection mechanism. It is preferable that the clutch has a second return spring and the urging force of the first return spring is set to be larger than the urging force of the second return spring.

In this way, when the transfer clutch and the disconnection / disconnection mechanism are engaged, the transfer clutch can be engaged after the synchro mechanism is engaged (the disconnection / disconnection mechanism is engaged). Further, when the transfer clutch and the disconnection / disconnection mechanism are released, the disconnection / disconnection mechanism can be released after the transfer clutch is released.

In the transfer of the all-wheel drive vehicle according to the present invention, it is preferable that the pressure receiving area of the oil chamber that applies hydraulic pressure to the transfer clutch is set smaller than the pressure receiving area of the oil chamber that applies hydraulic pressure to the disconnection / contact mechanism.

Even in this way, when the transfer clutch and the disconnection / disconnection mechanism are engaged, the transfer clutch can be engaged after the synchro mechanism is engaged (the disconnection / disconnection mechanism is engaged). Further, when the transfer clutch and the disconnection / disconnection mechanism are released, the disconnection / disconnection mechanism can be released after the transfer clutch is released.

According to the present invention, in a transfer of an all-wheel drive (AWD) vehicle having a multi-plate clutch, it is possible to eliminate a drag torque when the clutch is released and improve fuel efficiency while suppressing an increase in cost.

It is sectional drawing which shows the structure of the transfer which concerns on embodiment. It is a flowchart which shows the flow at the time of engaging a transfer clutch and a disconnection mechanism. It is a flowchart which shows the flow at the time of releasing a transfer clutch and a disconnection mechanism.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the figure, the same reference numerals are used for the same or corresponding parts. Further, in each figure, the same elements are designated by the same reference numerals, and duplicate description will be omitted.

First, the configuration of the transfer 1 of the all-wheel drive vehicle according to the embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view showing the configuration of the transfer 1.

The transfer 1 mainly includes a transfer shaft 10, a rear drive shaft 30 arranged coaxially with the transfer shaft 10, a transfer clutch 20 interposed between the transfer shaft 10 and the rear drive shaft 30, and a rear drive. It is configured to include a disconnection mechanism 40 provided between the first rear drive shaft 30a and the second rear drive shaft 30b constituting the shaft 30. Hereinafter, each component will be described in detail.

A counter-driven gear 11 is integrally formed on the outer periphery of the transfer shaft 10. Torque (that is, driving force converted by the transmission) is input to the transfer shaft 10 from a transmission such as a continuously variable transmission (CVT) or a step AT (stepped automatic transmission) via the counter-driven gear 11. Will be done.

Behind the transfer shaft 10, a first rear drive shaft 30a (corresponding to the first shaft described in the claims) and a second rear drive shaft 30b (corresponding to the second shaft described in the claims). The rear drive shaft 30 is arranged coaxially. The transfer shaft 10 and the rear drive shaft 30 are configured to be rotatable with each other via needle bearings. The rear drive shaft 30 is connected to a rear differential (not shown) via a propeller shaft (not shown) or the like, and the torque input from the transmission and adjusted by the transfer clutch 20 is applied to the rear wheels (secondary drive). Communicate to the wheel) side.

A transfer clutch 20 is provided between the transfer shaft 10 and the rear drive shaft 30 (first rear drive shaft 30a) on the torque transmission path. The transfer clutch 20 has a wet multi-plate clutch configured by alternately stacking a drive plate 20a provided on the transfer shaft 10 side and a driven plate 20b provided on the rear drive shaft 30 side.

A drum 21 to which a driven plate 20b is attached to an inner peripheral surface is provided at one end of the first rear drive shaft 30a (for example, the drum 21 is joined by welding or the like). Further, inside the drum 21, a transfer piston 22 whose end is in contact with the driven plate 20b is arranged. The oil chamber 23 is defined by the drum 21 and the transfer piston 22.

The transfer piston 22 is slidably provided in the axial direction of the rear drive shaft 30 and has a pressing force corresponding to the hydraulic pressure supplied to the oil chamber 23 (that is, the hydraulic pressure and the pressure receiving area (the surface perpendicular to the axial line). The pressing force (pressing pressure determined by the multiplication value with the area) is applied to the transfer clutch 20 (driven plate 20b). Further, the transfer piston 22 is provided with a first return spring 24 that applies an urging force to the transfer piston 22 (transfer clutch 20) in the direction in which the transfer clutch 20 is released (to the right in the drawing).

The transfer clutch 20 adjusts the torque output to the rear drive shaft 30 (that is, the rear wheel side) according to the hydraulic pressure supplied to the oil chamber 23. More specifically, by controlling the hydraulic pressure supplied to the oil chamber 23, that is, the pressing force by the transfer piston 22, the fastening force of the transfer clutch 20 is adjusted, and the front wheels (main drive wheels) and the rear wheels (secondary drive) are controlled. The torque distribution ratio with the wheel) is variable, for example, between 100: 0 and 50:50. The hydraulic pressure supplied to the transfer clutch 20 (oil chamber 23) is adjusted by an electronic control device (hereinafter referred to as “TCU”) 70 and a control valve 71, which will be described later.

Between the first rear drive shaft 30a and the second rear drive shaft 30b constituting the rear drive shaft 30, a disconnection mechanism 40 for disconnecting and disconnecting the connection between the first rear drive shaft 30a and the second rear drive shaft 30b is provided. It is provided. An outer spline 31 is formed so as to extend in the axial direction at the other end of the first rear drive shaft 30a. Further, an outer spline 32 is formed so as to extend in the axial direction at one end of the second rear drive shaft 30b.

The disconnection mechanism 40 mainly includes a sleeve piston 42, a sleeve 43, and an oil chamber 44. The sleeve piston 42 is formed in a substantially bottomed cylindrical shape in which a through hole through which the first rear drive shaft 30a penetrates is formed at the bottom. The sleeve piston 42 is arranged at the other end of the first rear drive shaft 30a so that the first rear drive shaft 30a penetrates the center thereof, that is, coaxially with the first rear drive shaft 30a. An inner spline 46 is formed on the inner peripheral surface of the sleeve piston 42 so as to extend in the axial direction. The inner spline 46 is arranged so as to always mesh with the outer spline 31 of the first rear drive shaft 30a. Therefore, the sleeve piston 42 is made slidable in the axial direction of the first rear drive shaft 30a while rotating integrally with the first rear drive shaft 30a.

Further, a cylindrical sleeve 43 is connected to the end of the sleeve piston 42. The sleeve piston 42 and the sleeve 43 may be joined by welding or the like, or may be integrally formed. At the end of the sleeve 43, a spline 47 that can be fitted with the outer spline 32 formed at one end of the second rear drive shaft 30b is formed so as to extend in the axial direction. Further, a chamfer with chamfered edges is formed at the tip of the spline 47.

The sleeve piston 42 is arranged inside a cylinder 41 provided at the other end of the first rear drive shaft 30a (for example, joined by welding or the like). The oil chamber 44 is defined by the cylinder 41 and the bottom surface of the sleeve piston 42. The sleeve piston 42 and the sleeve 43 are slidably provided in the axial direction of the first rear drive shaft 30a, and the pressing force (that is, the hydraulic pressure and the pressure receiving area (on the axis) according to the hydraulic pressure supplied to the oil chamber 44) is provided. It slides in the axial direction under the pressing force) determined by the multiplication value with the area of the surface perpendicular to it. As a result, the spline 47 formed on the sleeve 43 can be moved to a position where it meshes with the outer spline 32 formed on the second rear drive shaft 30b and a position where it disengages. Further, the sleeve piston 42 is provided with a second return spring 45 that applies an urging force to the sleeve piston 42 in a direction in which the disconnection mechanism 40 is released (leftward in the drawing).

Further, between the sleeve 43 and the outer spline 32 formed on the second rear drive shaft 30b, a synchro mechanism 51 (synchronizer ring) for synchronizing the rotations of both during engagement (during connection operation) is provided. There is. A spline that meshes with the sleeve 43 is provided on the outer periphery of the synchronization mechanism 51. A chamfer with chamfered edges is also formed at the tip of the spline.

The disconnection / disconnection mechanism 40 is controlled to be fastened / released according to the hydraulic pressure supplied to the oil chamber 44, and disconnects / disconnects the connection between the first rear drive shaft 30a and the second rear drive shaft 30b. Therefore, by controlling the hydraulic pressure supplied to the oil chamber 44, that is, the pressing force of the sleeve piston 42, the connection / disconnection mechanism 40 can be fastened / released. More specifically, when hydraulic pressure is supplied, the sleeve piston 42 and the sleeve 43 slide in the axial direction (to the right in the drawing), and the disconnection / disconnection mechanism 40 is fastened. On the other hand, when the hydraulic pressure is discharged, the disconnection mechanism 40 is released by the urging force of the second return spring 45. The hydraulic pressure supplied to the connection / disconnection mechanism 40 (oil chamber 44) is also adjusted by the TCU 70 and the control valve 71, which will be described later.

Here, the urging force of the first return spring 24 described above is set to be larger than the urging force of the second return spring 45. Therefore, when hydraulic pressure is supplied and the transfer clutch 20 and the disconnection mechanism 40 are engaged, the transfer clutch 20 is engaged after the synchronization mechanism 51 is engaged (the disconnection mechanism 40 is engaged). On the other hand, when the hydraulic pressure is discharged and the transfer clutch 20 and the disconnection mechanism 40 are released, the transfer clutch 20 is released and then the disconnection mechanism 40 is released.

Instead of or in addition to setting the urging force of the return spring, the pressure receiving area of the oil chamber 23 (transfer piston 22) that applies hydraulic pressure to the transfer clutch 20 is applied to the sleeve piston 42 (sleeve 43). It may be set smaller than the pressure receiving area of the oil chamber 44 (sleeve piston 42).

As described above, the hydraulic pressure supplied to the oil chamber 23 of the transfer clutch 20 and the oil chamber 44 of the disconnection mechanism 40 is controlled by the TCU 70 and the control valve 71. The TCU 70 and the control valve 71 function as the hydraulic control means described in the claims. The TCU 70 includes a microprocessor that performs operations, an EEPROM that stores a program for causing the microprocessor to execute each process, a RAM that stores various data such as calculation results, a backup RAM that holds the stored contents, and an input / output unit. It is configured to have an output I / F and the like.

The TCU 70 has the fastening force of the transfer clutch 20 (that is, the driving force distribution rate to the rear wheels) based on various information indicating the driving state of the vehicle (for example, the driving state of the four wheels, the engine torque, etc.) acquired from various sensors and the like. ) Is controlled in real time. At that time, the TCU 70 adjusts the hydraulic pressure supplied to the transfer clutch 20 by controlling the driving of the solenoid valves constituting the control valve 71, and adjusts the distribution ratio of the driving force transmitted to the rear wheels. The control valve 71 adjusts the hydraulic pressure discharged from the oil pump by opening and closing the oil passage formed in the control valve 71 by using the spool valve and the solenoid valve that moves the spool valve, and causes the transfer clutch 20. Supply hydraulic pressure to engage / disengage the clutch.

Further, the TCU 70 and the control valve 71 control the hydraulic pressure so as to release the disconnection / disconnection mechanism 40 when the transfer clutch 20 is released. The TCU 70 and the control valve 71 supply hydraulic pressure through a common hydraulic circuit 72 that communicates with an oil chamber 23 that applies hydraulic pressure to the transfer clutch 20 and an oil chamber 44 that applies hydraulic pressure to the disconnection mechanism 40. While the transfer clutch 20 is engaged and the disconnection / disconnection mechanism 40 is engaged, the transfer clutch 20 is released and the disconnection / disconnection mechanism 40 is released by discharging the hydraulic pressure.

Next, the operation of the transfer 1 will be described with reference to FIGS. 2 and 3. FIG. 2 is a flowchart showing a flow when the transfer clutch 20 and the disconnection / disconnection mechanism 40 are engaged. FIG. 3 is a flowchart showing a flow when the transfer clutch 20 and the disconnection / disconnection mechanism 40 are released.

First, the sequence for fastening the transfer clutch 20 and the disconnection / disconnection mechanism 40 will be described with reference to FIG. In step S100, the hydraulic pressure supplied to the transfer clutch 20 and the disconnection / disconnection mechanism 40 is increased. Then, in step S102, due to the increase in hydraulic pressure, the synchronization mechanism 51 is first engaged, and the disconnection mechanism 40 is fastened. More specifically, the sleeve 43 slides in the axial direction together with the sleeve piston 42 and is pushed out to the right side of the drawing. Then, after the rotations are synchronized by the synchronization mechanism 51, the sleeve 43 (spline 47) is fitted to the outer spline 32 formed on the second rear drive shaft 30b.

Subsequently, in step S104, the hydraulic pressure supplied to the transfer clutch 20 and the disconnection / disconnection mechanism 40 is further increased. Then, in step S106, the transfer clutch 20 is engaged. In this way, when the transfer clutch 20 and the disconnection mechanism 40 are engaged, the transfer clutch 20 is engaged after the synchronization mechanism 51 is engaged (the disconnection mechanism 40 is engaged).

Next, the sequence for releasing the transfer clutch 20 and the disconnection / disconnection mechanism 40 will be described with reference to FIG. First, in step S200, the hydraulic pressure supplied to the transfer clutch 20 and the disconnection / disconnection mechanism 40 is reduced. Therefore, in step S202, the transfer clutch 20 is released by the urging force of the first return spring 24. Subsequently, in step S204, the hydraulic pressure supplied to the transfer clutch 20 and the disconnection / disconnection mechanism 40 is further reduced. Therefore, in step S206, the disconnection mechanism 40 is released by the urging force of the second return spring 45. In this way, when the transfer clutch 20 and the disconnection mechanism 40 are released, the transfer clutch 20 is released and then the disconnection mechanism 40 is released.

As described in detail above, according to the present embodiment, when the transfer clutch 20 is released, the hydraulic pressure is controlled so that the sleeve 43 is slid in the axial direction and the disconnection mechanism 40 is released. Will be done. Therefore, when the transfer clutch 20 is released, the disconnection / disconnection mechanism 40 is released, and the first rear drive shaft 30a and the second rear drive shaft 30b (that is, the transfer clutch 20 and the drive system on the auxiliary drive wheel side). Is disconnected, the drag torque of the transfer clutch 20 is eliminated. Therefore, fuel efficiency can be improved. On the other hand, the above-mentioned disconnection mechanism 40 (dog clutch) can be realized with a relatively simple configuration, that is, at a relatively low cost. As a result, it is possible to eliminate the drag torque when the transfer clutch 20 is released and improve the fuel efficiency while suppressing the increase in cost.

According to this embodiment, it is possible to control the engagement / release of the transfer clutch 20 and the disconnection / disconnection mechanism 40 by using the common hydraulic circuit 72 and the common hydraulic pressure. That is, it is not necessary to newly add a dedicated hydraulic circuit (hydraulic pipe), a solenoid valve for hydraulic control, or the like, and it is possible to suppress an increase in cost.

According to the present embodiment, the sleeve 43 and the outer spline 32 formed on the second rear drive shaft 30b are provided with a synchro mechanism 51 that synchronizes the rotations of both when engaged with the sleeve 43. Even if the rotation speeds of the sleeve 43 (connecting mechanism 40) and the outer spline 32 (second rear drive shaft 30b) are different when engaged with the outer spline 32, the sleeve 43 and the outer spline can be more smoothly engaged. It is possible to engage with 32, that is, to fasten the disconnection mechanism 40.

According to the present embodiment, when hydraulic pressure is supplied and the transfer clutch 20 and the disconnection mechanism 40 are engaged, the transfer clutch 20 is engaged after the synchronization mechanism 51 is engaged (the disconnection mechanism 40 is engaged). Will be done. Therefore, when the synchro mechanism 51 is engaged, the transfer clutch 20 is not yet engaged (that is, the transmission or the like is not connected), so that the inertia is small. Therefore, the inertia can be easily absorbed (that is, the shortage of the torque capacity of the synchro mechanism 51 can be avoided).

According to the present embodiment, when the hydraulic pressure is discharged and the transfer clutch 20 and the disconnection mechanism 40 are released, the transfer clutch 20 is released and then the disconnection mechanism 40 is released. Therefore, when the disconnection / disconnection mechanism 40 is released, the transfer clutch 20 is already released and the input torque from the transmission side is lost, so that the sleeve 43 can be easily removed (that is, the disconnection / disconnection mechanism 40 is released). can do.

According to the present embodiment, the urging force of the first return spring 24 that applies the urging force in the direction of releasing the transfer clutch 20 causes the urging force of the second return spring 45 that applies the urging force in the direction of releasing the disconnection mechanism 40. It is set larger than the urging force. Therefore, when the transfer clutch 20 and the disconnection mechanism 40 are engaged, the transfer clutch 20 can be engaged after the synchronization mechanism 51 is engaged (the disconnection mechanism 40 is engaged). Further, when the transfer clutch 20 and the disconnection / disconnection mechanism 40 are released, the disconnection / disconnection mechanism 40 can be released after the transfer clutch 20 is released.

According to the present embodiment, the pressure receiving area of the oil chamber 23 that applies hydraulic pressure to the transfer clutch 20 can be set to be smaller than the pressure receiving area of the oil chamber 44 that applies hydraulic pressure to the disconnection mechanism 40. After the mechanism 51 is engaged (the disconnection / disconnection mechanism 40 is engaged), the transfer clutch 20 can be engaged. Further, after the transfer clutch 20 is released, the disconnection / disconnection mechanism 40 can be released.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be modified in various ways. For example, in the above embodiment, the first rear drive shaft 30a and the second rear drive shaft 30b are configured to be intermittent, but in addition to the above configuration, for example, a propeller shaft and a rear wheel (secondary drive wheel) are used. A connection / disconnection mechanism may be provided between them so that both can be separated from each other.

Further, the type of the all-wheel drive vehicle (AWD) is not limited to the above embodiment, and the present invention can be applied to other types of all-wheel drive vehicles.

Further, the configuration of the disconnection mechanism 40 is not limited to the above embodiment, and the sleeve piston 42 may be configured without the inner spline 46. That is, the spline 47 formed on the sleeve 43 slides in the axial direction while constantly meshing with the outer spline 31 of the first rear drive shaft 30a (that is, the outer spline 32 formed on the second rear drive shaft 30b). (Move to a position where the mesh is engaged with and a position where the mesh is disengaged), and the second rear drive shaft 30b (outer spline 32) can be connected and disconnected.

1 Transfer 10 Transfer Shaft 20 Transfer Clutch 20a Drive Plate 20b Driven Plate 21 Drum 22 Transfer Piston 23 Oil Chamber 24 1st Return Spring 30 Rear Drive Shaft 30a 1st Rear Drive Shaft 30b 2nd Rear Drive Shaft 31 External Spline 32 External Spline 40 Disconnection mechanism 41 Cylinder 42 Sleeve piston 43 Sleeve 44 Oil chamber 45 Second return spring 46 Inner spline 47 Spline 51 Synchro mechanism 70 TCU
71 Control valve 72 Hydraulic circuit

Claims (8)

A transfer clutch that has a multi-plate clutch, adjusts the torque input from the transmission according to the supplied hydraulic pressure, and outputs it to the auxiliary drive wheel side.
A first shaft whose one end is connected to the output side of the transfer clutch,
A second shaft provided coaxially with the first shaft and having a spline formed at one end thereof, and a second shaft.
A disconnection mechanism that interrupts the connection between the first shaft and the second shaft according to the hydraulic pressure supplied between the first shaft and the second shaft.
The transfer clutch and the hydraulic pressure control means for controlling the hydraulic pressure supplied to each of the disconnection and disconnection mechanisms are provided.
In the disconnection mechanism, a spline that can be fitted with a spline formed on the second shaft is formed, and the spline can rotate integrally with the first shaft, and the first shaft can be rotated according to the hydraulic pressure supplied. And has a sleeve provided so as to be slidable in the axial direction of the second shaft.
The transfer of an all-wheel drive vehicle, wherein the hydraulic pressure control means controls the hydraulic pressure so as to release the disconnection / disconnection mechanism when the transfer clutch is released. The first shaft has a spline formed at the other end thereof.
The transfer of an all-wheel drive vehicle according to claim 1, wherein the disconnection mechanism has a spline formed on the first shaft and a spline that is constantly spline-fitted. The hydraulic pressure control means is passed through a common hydraulic circuit communicating with an oil chamber for applying hydraulic pressure to the transfer clutch and an oil chamber for applying hydraulic pressure to the disconnection mechanism.
By supplying hydraulic pressure, the transfer clutch is engaged, and the disconnection / disconnection mechanism is engaged.
The transfer of an all-wheel drive vehicle according to claim 1 or 2, wherein the transfer clutch is released and the disconnection / disconnection mechanism is released by discharging the hydraulic pressure. 3. All-wheel drive vehicle transfer described. The fourth aspect of claim 4, wherein the transfer clutch is engaged after the synchro mechanism is engaged when hydraulic pressure is supplied and the transfer clutch and the disconnection mechanism are engaged. Transfer of all-wheel drive vehicle. 4 or 5 according to claim 4, wherein when the hydraulic pressure is discharged and the transfer clutch and the disconnection mechanism are released, the transfer clutch is released and then the disconnection mechanism is released. All-wheel drive vehicle transfer described. A first return spring that applies an urging force to the transfer clutch in the direction of releasing the transfer clutch,
It has a second return spring that applies an urging force to the disconnection mechanism in the direction of releasing the disconnection mechanism.
The transfer of an all-wheel drive vehicle according to claim 5 or 6, wherein the urging force of the first return spring is set to be larger than the urging force of the second return spring. One of claims 5 to 7, wherein the pressure receiving area of the oil chamber on which the hydraulic pressure is applied to the transfer clutch is set to be smaller than the pressure receiving area of the oil chamber on which the hydraulic pressure is applied to the disconnection mechanism. All-wheel drive vehicle transfer described in section.

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