JP2022175727A - Vehicular four-wheel drive device - Google Patents

Abstract

To provide a vehicular four-wheel drive device capable of simultaneously improving traveling performance such as bad road running performance and downsizing a structure as a whole.SOLUTION: A vehicular four-wheel drive device comprises: an engine 1; a motor 2; a rear wheel 7 to which driving force can be transmitted from the engine 1; a front wheel 10 to which a driving force can be transmitted from the motor 2; an input shaft 4; a rear output shaft 5 that is coupled to the input shaft 4; a differential mechanism 3 that comprises a sun gear 3s coupled with the motor 2, a ring gear 3r, and a carrier 3c, and performs a differential action with three rotary elements; a front output shaft 9 that outputs driving force transmitted from the carrier 3c to the front wheel 10; a first coupling portion 13 that couples and releases the input shaft 4 and the carrier 3c; and a fixed coupling portion 14 that fixes and release the ring gear 3r.SELECTED DRAWING: Figure 1

Description

The present invention relates to a four-wheel drive system capable of selectively driving four front and rear wheels of a vehicle.

Japanese Patent Laid-Open No. 2002-200003 describes a device configured to transmit driving force to all wheels of a vehicle so that the vehicle can run. The device described in Patent Document 1 is an all-wheel drive vehicle equipped with a center differential that distributes the output torque of a driving force source consisting of an engine and a first electric motor generator to the rear wheel side and the front wheel side. Furthermore, a differential limiting clutch is provided which connects the second electric motor/generator via a drive force distribution change mechanism consisting of a planetary gear mechanism and limits the differential action of the drive force distribution change mechanism. In the device described in Patent Document 1, the ratio between the driving torque transmitted to the rear wheels and the driving torque transmitted to the front wheels is changed by positive or negative torque transmitted from the second motor generator to the center differential. can be done. Further, when the differential limiting clutch is engaged, the driving force distribution changing mechanism rotates as one unit, and the driving force distribution changing mechanism is connected to the output shaft on the rear wheel side. 2 It is possible to run as an electric vehicle (EV running) using the motor generator as a driving force source.

JP 2007-246056 A

The load applied to the rear and front wheels or the drive torque borne by the wheels varies in various ways according to the vehicle's running conditions, such as acceleration/deceleration, turning, and uphill/downhill conditions. According to the device described in Patent Document 1, the ratio of distributing the driving torque output by the driving force source to the rear wheels and the front wheels can be continuously changed by the second electric motor-generator. and the front wheels can be adjusted to match the running state of the vehicle. On the other hand, four-wheel drive vehicles (or all-wheel drive vehicles) are sometimes required to have the ability to run on rough roads such as muddy roads (rough road running performance). It is necessary to increase the total driving force obtained by all of the above, and it is also required to limit the differential between the front and rear wheels. In the device described in Patent Document 1, since the transmission is provided between the driving force source and the center differential, the total driving torque can be increased by increasing the gear ratio of the transmission. In addition, when the differential is limited, the drive torque output by the second motor generator can be distributed and transmitted to all the wheels during EV travel in which the vehicle travels only with the second motor generator. However, when the differential is limited, the center differential rotates as a whole and outputs the transmitted torque as it is. Therefore, in the device described in Patent Document 1, it is not always possible to sufficiently increase the driving force when traveling in all-wheel drive using the second motor generator as the driving force source. If an amplifying mechanism is additionally provided, the size of the device will increase. As described above, conventionally, there is room for improvement in terms of so-called bad road running performance and device miniaturization.

The present invention has been made in view of the above technical problems, and provides a vehicle four-wheel drive system configured to transmit driving force from a driving force source to driving wheels via a differential mechanism, The object is to increase the driving force without causing an increase in size.

In order to achieve the above objects, the present invention provides a first driving force source, a second driving force source, first driving wheels capable of transmitting driving force from the first driving force source, and a second driving force. A vehicle four-wheel drive device comprising a second driving wheel capable of transmitting a driving force from a source, an input member to which the driving torque of the first driving force source is transmitted; A first output member that outputs drive torque to a first drive wheel, an input element to which torque is transmitted from the second drive force source, and a fixing that is selectively connected to a predetermined fixing portion to stop rotation. and an output element that rotates at a reduced speed with respect to the input element while the fixed element is connected to the fixed part, and differential action is performed by the three rotary elements. connecting the first driving force source and the input element by engaging a driving mechanism and a second output member that outputs the driving force transmitted from the output element to the second driving wheel; a first connecting portion that disconnects the first driving force source and the input element when released; and a first connecting portion that engages to connect the fixing element to the fixing portion and releases the fixing element. and a fixed connection portion that releases connection with the fixed portion, engages the first connection portion, releases the fixed connection portion, and applies the driving torque output by the first driving force source to the first driving force source. A first drive mode in which the driving force is transmitted to the first drive wheel and the second drive wheel, and a drive output from the second drive force source in which the first connection portion is released and the fixed connection portion is engaged. A second running mode in which torque is amplified by the differential mechanism and transmitted to the second drive wheels for running can be set.

In the present invention, the driving torque output from the first driving force source is transmitted to the first driving wheel and the second driving wheel by engaging the first connecting part and releasing the fixed connecting part. and a first running mode in which the vehicle travels in the second driving mode, and a second driving mode in which the first connecting portion is released and the fixed connecting portion is engaged so that the differential mechanism amplifies the driving torque output from the second driving force source. can be set to a second running mode in which the power is transmitted to the second drive wheels to run. Therefore, when the present invention is applied to a hybrid vehicle in which the first driving force source is composed of an internal combustion engine and the second driving force source is composed of a motor or a motor generator (hereinafter collectively referred to as a motor), the motor It is possible to increase the driving force necessary and sufficient when traveling with the vehicle, and eliminate the need for a special mechanism for increasing the driving force so that the overall configuration of the device can be reduced in size and weight. Further, when traveling with the internal combustion engine, which is the first driving force source, the driving torque can be distributed to the first driving wheel and the second driving wheel by the differential mechanism, in which case the vehicle is driven by the torque of the second driving force source. If the motor can adjust the torque and has a power generation function, the motor can generate power and recover the energy.

It is a skeleton diagram showing one embodiment of the present invention, (A) shows the state where the 1st run mode is set, and (B) shows the state where the 2nd run mode is set. FIG. 2 is a nomographic chart for explaining the operating state of the embodiment shown in FIG. 1, where (A) shows the state in which the first traveling mode is set, and (B) shows the state in which the second traveling mode is set; indicates that the FIG. 4 is a skeleton diagram showing a second embodiment of the present invention; FIG. 5 is a skeleton diagram showing a third embodiment of the present invention; FIG. 11 is a skeleton diagram showing a fourth embodiment of the invention; FIG. 11 is a skeleton diagram showing a fifth embodiment of the present invention; FIG. 11 is a skeleton diagram showing a sixth embodiment of the present invention; FIG. 11 is a skeleton diagram showing a seventh embodiment of the present invention; FIG. 11 is a skeleton diagram showing an eighth embodiment of the present invention; Fig. 10 is a skeleton diagram showing a ninth embodiment of the present invention, (A) showing a state in which a running mode is set in which the front and rear wheels are driven by an engine and a motor, and (B) showing a differential mechanism. (C) shows the driving mode in which the engine and motor drive the rear wheels with the engine and motor set to low speed, and (C) sets the differential mechanism to high speed (directly coupled stage) and drives the rear wheels with the engine and motor. shows the state in which the driving mode is set. Fig. 10 is a skeleton diagram showing a tenth embodiment of the present invention, (A) showing a state in which a running mode is set in which the front and rear wheels are driven by an engine and a motor, and (B) showing a differential mechanism. (C) shows the driving mode in which the engine and motor drive the rear wheels with the engine and motor set to low speed, and (C) sets the differential mechanism to high speed (directly coupled stage) and drives the rear wheels with the engine and motor. shows the state in which the driving mode is set.

Next, a specific example of carrying out the present invention will be described. It should be noted that the specific example described below is merely an example of the present invention, and does not limit the present invention.

1A and 1B are skeleton diagrams schematically showing main parts of a four-wheel drive system according to the present invention. This four-wheel drive system is an internal combustion engine (ENG, hereinafter referred to as engine). 1 and a motor-generator (MG, hereinafter referred to as a motor) 2 are mounted on a vehicle as driving force sources. A differential mechanism 3 is provided to combine the power of the engine 1 and the motor 2 . An example of the differential mechanism 3 is a planetary gear mechanism, and FIG. 1 shows a single pinion type planetary gear mechanism. The differential mechanism 3 includes a sun gear 3s that is an external gear, a ring gear 3r that is an internal gear that is arranged concentrically with the sun gear 3s, and a pinion gear 3p that meshes with the sun gear 3s and the ring gear 3r. and a carrier 3c held so as to be able to revolve are used as rotating elements, and these three rotating elements are configured to perform a differential action.

An input shaft 4 corresponding to an input member according to the present invention, to which power is transmitted from the engine 1 corresponding to a first driving force source according to the present invention, is arranged along the rotation center axis of the differential mechanism 3. 4 is connected to a rear output shaft 5 corresponding to the first output member in the present invention. The rear output shaft 5 is connected via a final reduction gear 6 and the like to a rear wheel 7 corresponding to a first drive wheel in the present invention. That is, it is configured to output driving force from the rear output shaft 5 to the rear wheels 7 .

A motor 2 corresponding to a second driving force source in the present invention is arranged on the same axis as the input shaft 4 and closer to the engine 1 than the differential mechanism 3 is. The motor 2 is, for example, a permanent magnet type synchronous motor, and its rotor 2R is connected to the sun gear 3s in the differential mechanism 3 by a rotor shaft 8. As shown in FIG.

In the example shown in FIG. 1, the carrier 3c in the differential mechanism 3 is the output element, and the driving force is output from the carrier 3c to the front output shaft 9 corresponding to the second output member in the present invention. ing. The front output shaft 9 is arranged parallel to the input shaft 4 and the rotor shaft 8, and is connected to the front wheels 10 corresponding to the second driving wheels in the present invention via a final reduction gear 11 and the like. As the transmission mechanism for transmitting torque between the front output shaft 9 and the carrier 3c in the differential mechanism 3, an appropriate mechanism can be adopted as necessary. A chain mechanism 12 is used. That is, a driving sprocket 12a is integrated with the carrier 3c, a driven sprocket 12b is integrated with the front output shaft 9, and a chain 12c is wound around these sprockets 12a and 12b. These sprockets 12a and 12b may have the same diameter, but by making the diameter of the driven sprocket 12b larger than the diameter of the drive sprocket 12a, it can function as a reduction mechanism.

The power transmission device shown in FIG. 1 can set at least two running modes in which the mode of transmission of driving force to each driving wheel 7, 10 is different, and two connecting portions 13, 14 for this purpose are provided. . These connecting portions 13 and 14 are for selectively transmitting and interrupting torque, and conventionally known configurations such as a configuration in which torque is transmitted by frictional force, a configuration in which torque is transmitted by engagement of teeth, etc. Various configurations can be appropriately employed, and in the example shown in FIG. 1, a mesh type engaging means, ie, a dog clutch is used.

Specifically, first, the first connecting portion 13 is an engaging mechanism for selectively connecting the input shaft 4 and the ring gear 3r functioning as a fixed element or a reaction element, and is integrated with the ring gear 3r. A hub (hereinafter sometimes referred to as a ring gear hub) 13a provided integrally with the input shaft 4 (or the rear output shaft 5) (hereinafter sometimes referred to as an input hub) is integrally provided. 13b, and a sleeve 13c that moves axially along the outer periphery of these hubs 13a, 13b and meshes with the spline teeth formed on the outer periphery of these hubs 13a, 13b. By moving the sleeve 13c leftward as shown in FIG. 1(A) by an actuator (not shown), the sleeve 13c meshes with the hubs 13a and 13b so that the ring gear 3r and the input shaft 4 or the rear output shaft 5 are engaged. concatenated. That is, the first connecting portion 13 is engaged. On the contrary, when the sleeve 13c and the ring gear hub 13a are moved rightward as shown in FIG. 13b (connection between the ring gear 3r and the input shaft 4 or the rear output shaft 5) is released.

The other connecting portion 14 is an engagement mechanism for fixing the ring gear 3r, and is hereinafter referred to as the fixed connecting portion 14. As shown in FIG. The fixed connection portion 14 includes a hub (hereinafter sometimes referred to as a second ring gear hub) 14a provided integrally with the ring gear 3r, a predetermined fixed portion 15 such as a casing having spline teeth formed thereon, It has a sleeve 14b that selectively meshes with the second ring gear hub 14a and the fixed portion 15 by moving in the axial direction. When the sleeve 14b is moved leftward by an actuator (not shown) as shown in FIG. 1A, the sleeve 14b is disengaged from the second ring gear hub 14a or the fixed portion 15 and the fixed connecting portion 14 is released. , the ring gear 3r is unlocked and becomes rotatable. Further, as shown in FIG. 1B, the sleeve 14b is moved to the right side by an actuator (not shown) to mesh with the second ring gear hub 14a and the fixed portion 15, whereby the fixed connecting portion 14 is engaged. , the ring gear 3r is connected to the fixed portion 15 and the rotation of the ring gear 3r is stopped (fixed).

In the four-wheel drive system according to the present invention described above, since the two connecting portions 13 and 14 are provided, a plurality of driving modes can be set according to the engagement and disengagement states of these connecting portions 13 and 14. be able to. For example, while the drive torque output by the engine 1 is transmitted to the rear wheels 7, it is distributed to the motor 2 and the front wheels 10 via the differential mechanism 3 to drive the four wheels. A driving mode in which the differential mechanism 3 amplifies and transmits to the front wheels 10 can be set.

(A) of FIG. 1 sets a running mode in which the engine 1 drives the front and rear four wheels and the engine 1 and the motor 2 are connected via the differential mechanism 3. state. This running mode can be called a split mode and corresponds to the first running mode in the present invention. In this first running mode, the fixed connecting portion 14 is released to disconnect the ring gear 3r and the fixed portion 15, and the first connecting portion 13 is engaged to connect the ring gear 3r to the input shaft 4 (engine 1). is set as The operating state of the differential mechanism 3 in this first running mode is shown in a collinear diagram in FIG. 2(A). As is conventionally known, the collinear chart shows each rotating element that constitutes the differential mechanism 3 with vertical lines, and the distance between those lines is the planetary gear mechanism that constitutes the differential mechanism 3. 2 is a diagram showing the number of revolutions at positions from the base line of the vertical line indicating each rotating element, with the intervals corresponding to the gear ratio (ratio between the number of teeth of the sun gear and the number of teeth of the ring gear) in .

In the differential mechanism 3, the driving torque output by the engine 1 is input to the ring gear 3r, so the ring gear 3r serves as an input element. The sun gear 3c serves as an output element, and the motor 2 outputs torque as an electric motor (motor), so that the sun gear 3s is applied with torque in the direction of increasing its rotational speed, so the sun gear 3s serves as a reaction force element. In other words, the driving torques of the engine 1 and the motor 2 are combined in the differential mechanism 3 . Further, as shown in FIG. 2A, the rotational speed of the ring gear 3r corresponds to the rotational speed of the engine or the rotational speed of the rear wheels 7, and the rotational speed of the carrier 3c corresponds to the rotational speed of the front wheels 10. The rotation speed of the sun gear 3s, that is, the rotation speed of the motor 2, is determined by the rotation speed of the ring gear 3r and the carrier 3c and the gear ratio of the planetary gear mechanism forming the differential mechanism 3.

In the first travel mode, as described above, both the engine 1 and the motor 2 function as driving force sources, so the driving force of the vehicle as a whole increases. In addition, since all the wheels (four wheels) including the rear wheels 7 and the front wheels 10 serve as drive wheels, the rough road running performance and running stability are improved. Further, the rear wheels 7 are driven by the engine 1, and the front wheels 10 are driven by the driving force transmitted from the differential mechanism 3 to which driving torque is input from the engine 1 and the motor 2. A state similar to that in which the differential is limited is achieved, and a situation such as loss of torque from either one of the front and rear wheels 7 and 10 does not occur.

On the other hand, FIG. 1(B) shows a so-called low-speed ratio running mode in which the differential mechanism 3 functions as a reduction mechanism to amplify the drive torque output by the motor 2 and transmit it to the front wheels 10. It shows the state of setting the mode. This running mode corresponds to the second running mode in the present invention. In the second running mode, in order to allow the differential mechanism 3 to function as a reduction gear mechanism, the ring gear 3r is fixed by engaging the fixed connection portion 14 and connected to the fixed portion 15, and the first connection is made to this. The portion 13 is released, and the connection between the ring gear 3r and the input shaft 4 or the engine 1 is released. This state is shown in a collinear diagram in FIG. 2B. In the differential mechanism 3, the ring gear 3r is a fixed element, and the driving torque of the motor 2 is input to the sun gear 3s. is the input element and the carrier 3c is the output element. Therefore, the driving torque of the motor 2 is amplified and output to the front wheels 10 from the carrier 3c. On the other hand, since the first connecting portion 13 is released and the ring gear 3r is disconnected from the engine 1, the engine 1 can drive the rear wheels 7 only.

Therefore, in the second driving mode, the vehicle can be driven as a front-wheel drive vehicle using only the motor 2 as a driving force source, and can be driven as an all-wheel drive vehicle (four-wheel drive vehicle) by driving the engine 1 in addition to the motor 2. can run. In any of these cases, the driving torque output from the motor 2 is amplified by the differential mechanism 3 and transmitted to the front wheels 10, so that the driving force of the vehicle as a whole can be increased. can improve sexuality. Also, if the motor 2 functions as a generator during deceleration, energy is regenerated from the front wheels 10 to which a large braking torque is applied, so that regeneration efficiency can be improved.

In the above-described four-wheel drive system according to the present invention, the differential mechanism 3 functions as a power distribution mechanism and a speed reduction mechanism so that various driving modes can be set. In order to improve performance and energy efficiency, it is possible to reduce the number of required structural members, simplifying and reducing the weight of the entire device or vehicle.

The present invention maintains the basic configuration and can be implemented by changing the configuration and arrangement of the connecting portions 13 and 14, or the arrangement of the chain mechanism (transmission mechanism) 12, etc., from the above-described specific example. Examples are described below. In the example described below, the rear wheel 7, the front wheel 10, and the front and rear final reduction gears 6 and 11 have the same configurations as in the above-described specific example, so their description and illustration are omitted.

In the example shown in FIG. 3, the arrangement order of the motor 2, the chain mechanism (transmission mechanism) 12, the differential mechanism 3, and the connecting portions 13 and 14 (arrangement order in the longitudinal direction of the vehicle) is different from the order shown in FIG. is an inverted example. That is, the input shaft 4 is arranged on the same axis as the rotation center axis of the engine 1, the input hub 13b is provided at the end of the input shaft 4 on the side of the engine 1, and is adjacent to the input hub 13b and on the rear side of the vehicle. A differential mechanism 3 is arranged at . A first connecting portion 13 and a fixed connecting portion 14 are arranged in order from the front side in the longitudinal direction of the vehicle on the outer peripheral side of the input hub 13b and the differential mechanism 3 . The chain mechanism 12 is arranged on the vehicle rear side of the differential mechanism 3 and the fixed connecting portion 14 , and the motor 2 is arranged on the vehicle rear side of the chain mechanism 12 .

Even with the configuration shown in FIG. 3, it is possible to operate in the same manner as in the example shown in FIG. Further, particularly in the configuration shown in FIG. 3, by arranging the chain mechanism 12 on the front side of the vehicle relative to the motor 2, which tends to have a long shaft length, the front output shaft 9 extending from the chain mechanism 12 to the front side of the vehicle can be shortened. .

The example shown in FIG. 4 is an example in which an engagement mechanism for integrating the entire differential mechanism 3 is added to the configuration shown in FIG. That is, as shown in FIG. 4, a second connecting portion 16 is provided for selectively connecting the sun gear 3s and the carrier 3c in the differential mechanism 3. The second connecting portion 16 is a frictional clutch such as a multi-plate clutch. It is configured by an engagement mechanism.

In the configuration shown in FIG. 4, a running mode can be set in which the first connecting portion 13 and the fixed connecting portion 14 are released and the second connecting portion 16 is engaged. In that case, the differential mechanism 3 rotates as a whole by connecting two of its rotating elements. Therefore, the drive torque output by the motor 2 is transmitted to the front wheels 10 without being increased or decreased by the differential mechanism 3 . That is, the differential mechanism 3 does not function as a speed change mechanism, or functions as a power transmission mechanism with a speed ratio of "1". As a result, when the motor 2 is used alone or together with the engine 1 as a driving force source, the number of rotations of the motor 2 is lower than when the differential mechanism 3 is used to reduce the speed. The power consumption rate (electricity cost) can be improved by lowering the motor rotation speed. Further, in the configuration shown in FIG. 4 , the drive torque output by the motor 2 can be transmitted to the chain mechanism 12 without going through the differential mechanism 3 . Therefore, since the torque applied to the differential mechanism 3 is small, the differential mechanism 3 can be miniaturized. It should be noted that even with the configuration shown in FIG. 4, it is possible to operate in the same manner as the configuration shown in FIG. 1 and obtain the same actions and effects.

In order to integrate the entire differential mechanism 3, at least any two rotating elements should be connected. Therefore, the second connecting portion 16 may be configured to connect the carrier 3c and the ring gear 3r as shown in FIG. 5, or may be configured to connect the carrier 3c and the ring gear 3r as shown in FIG. As shown, the sun gear 3s and the ring gear 3r may be connected. 5 and 6, when the motor 2 is used alone or in combination with the engine 1 as a driving force source, the rotational speed of the motor 2 is reduced by the differential mechanism 3. Since the number of revolutions is lower than that of , the power consumption rate (electricity cost) can be improved by reducing the number of revolutions of the motor at high vehicle speeds. Further, it is possible to obtain the same functions and effects by operating in the same manner as in the configuration shown in FIG. 1 described above.

The example shown in FIG. 7 is an example in which the configuration of the fixing portion 15 is changed from the configuration shown in FIG. In the example shown in FIG. 1, the fixed portion 15 is arranged in line with the ring gear 3r in the axial direction, and the sleeve 14b is arranged on the outer peripheral side thereof so as to be movable in the axial direction. In contrast, in the example shown in FIG. 7, a fixed portion 15 is provided on the outer peripheral side of the second ring gear hub 14a, and spline teeth are formed on the inner surface of the fixed portion 15 (the surface facing the ring gear 3r). Spline teeth are formed on both the inner peripheral surface and the outer peripheral surface of the sleeve 14b, and the sleeve 14b is inserted between the second ring gear hub 14a and the fixed portion 15 so that the sleeve 14b is connected to the second ring gear hub. 14a and the fixed portion 15 are engaged with each other to connect them, and the sleeve 14b slips out from between the second ring gear hub 14a and the fixed portion 15 in the axial direction so that the sleeve 14b engages the second ring gear hub 14a and the fixed portion 14a. 15 and is configured to release the connection between them. Therefore, in the configuration shown in FIG. 7, the number of parts arranged side by side in the axial direction is reduced, so that the overall axial length of the four-wheel drive system can be shortened.

The configuration shown in FIG. 8 is an example in which the rear wheels 7 are driven by the motor 2 in addition to the engine 1 . Specifically, in the configuration shown in FIG. 8, in addition to the configuration shown in FIG. and the input shaft 4 are additionally provided. These connecting portions 18 and 19 may be meshing engagement mechanisms, friction engaging mechanisms, or the like. In the example shown in FIG. is composed of a friction engagement mechanism.

Therefore, in the configuration shown in FIG. 8, by disengaging the first connecting portion 13 and the third connecting portion 18 and engaging the fixed connecting portion 14 and the fourth connecting portion 19, the motor 2 is operated in addition to the engine 1. It is connected to the rear output shaft 5 or the rear wheels 7 . Specifically, in the differential mechanism 3, the ring gear 3r is connected and fixed to the fixed portion 15, and the carrier 3c is disconnected from the chain mechanism 12 (or the front wheel 10) and connected to the input shaft 4 or the rear output shaft 5. , the drive torque is input from the motor 2 to the sun gear 3s in this state. Therefore, the differential mechanism 3 functions as a reduction mechanism having the sun gear 3s as an input element, the ring gear 3r as a fixed element, and the carrier 3c as an output element. The power is output from the rear output shaft 5 to the rear wheels 7 . Since the engine 1 is connected to the rear output shaft 5 via the input shaft 4, the rear wheels 7 are driven by the drive torque of the engine 1 and the motor 2, and the vehicle is in a two-wheel drive state. Also in this case, the driving torque output by the motor 2 can be amplified by the differential mechanism 3, so that a large driving force can be obtained.

The example shown in FIG. 9 is an example in which the above-described second connecting portion 16 is added to the configuration shown in FIG. With the configuration shown in FIG. 9, by engaging the second connecting portion 16, the entire differential mechanism 3 can be integrated and rotated. Therefore, the second coupling portion 14 is engaged with the fixed coupling portion 14 and the third coupling portion 18 released, and the differential mechanism 3 is integrated as a whole. By engaging the connecting portion 19 , the integrally rotating differential mechanism 3 is connected to the input shaft 4 or the rear output shaft 5 . That is, the motor 2 is connected to the input shaft 4 or the rear output shaft 5 . As a result, the driving torque of the motor 2 is transmitted to the rear wheels 7 in addition to the engine 1, so that the vehicle is in a two-wheel drive state in which the rear wheels 7 are driven. In this case, the differential mechanism 3 does not function as a speed change mechanism or functions as a power transmission mechanism with a speed change ratio of "1", so the rotational speed of the motor 2 is lower than when the differential mechanism 3 reduces speed. Therefore, the power consumption rate (electricity cost) can be improved by lowering the motor rotation speed at high vehicle speeds.

In the example shown in FIG. 10, in the configuration shown in FIG. 9, the first connecting portion 13 connecting the ring gear 3r and the input shaft 4, the second connecting portion 16, and the fourth connecting portion 19 share the components. This is an example configured to achieve Specifically, between the ring gear hub 13a and the input hub 13b, there is provided a carrier hub 16a which is integrated with the carrier 3c and has spline teeth formed on its outer peripheral surface. The sleeve 13c, which is a part of the first connecting portion 13, has a length that meshes only with the ring gear hub 13a. It is The sleeve 19a has such a length that it meshes with the ring gear hub 13a, the carrier hub 16a and the input hub 13b which are arranged in the axial direction at the same time. Further, the distance between these sleeves 13c and 19a is such that when the sleeve 13c constituting the first connecting portion 13 is engaged with the ring gear hub 13a, the sleeve 19a is engaged with the input hub 13b and the sleeve 13c is engaged with the first connection. When the portion 13 is disengaged from the ring gear hub 13a, the distance is set so that the sleeve 19a meshes with the input hub 13b and the carrier hub 16a, or simultaneously meshes with the ring gear hub 13a, the carrier hub 16a and the input hub 13b. . Other configurations are the same as those shown in FIG.

FIG. 10(A) shows a state in which a running mode that can be called a split mode similar to the running mode shown in FIG. 1(A) is set. In this running mode, the sleeve 13c corresponding to the first connecting portion 13 meshes with the ring gear hub 13a, and the sleeve 19a integrated with the sleeve 13c meshes with the input hub 13b, so that the ring gear 3r and the input shaft 4 (or the rear output shaft) are engaged. 5) are connected. Also, the fixed link 14 is released and the third link 18 is engaged to connect the carrier 3c to the chain mechanism 12. As shown in FIG.

The running mode set as shown in (A) of FIG. 10 corresponds to the first running mode in the present invention. The driving force of the vehicle as a whole is increased. In addition, since all the wheels (four wheels) including the rear wheels 7 and the front wheels 10 serve as drive wheels, the rough road running performance and running stability are improved. Further, the rear wheels 7 are driven by the engine 1, and the front wheels 10 are driven by the driving force transmitted from the differential mechanism 3 to which driving torque is input from the engine 1 and the motor 2. A state similar to that in which the differential is limited is achieved, and a situation such as loss of torque from either one of the front and rear wheels 7 and 10 does not occur.

FIG. 10B shows a two-wheel drive mode in which the rear wheels 7 are driven by the driving torque of the engine 1 and the motor 2 to run. In this running mode, the front wheels 10 are disconnected from the differential mechanism 3 because the third coupling portion 18 is released, and the driving force is not transmitted. Further, the fixed connecting portion 14 is in the engaged state and the ring gear 3r is fixed, so that the differential mechanism 3 functions as a reduction mechanism. Further, the sleeves 13c and 19a, which are integrated with each other, move one pitch leftward in FIG. 10 from the position shown in FIG. 19a meshes with input hub 13b and carrier hub 16a to connect carrier 3c and input shaft 4 (or rear output shaft 5).

Therefore, the drive torque output by the motor 2 is amplified by the differential mechanism 3, output from the carrier 3c, and transmitted to the input shaft 4 (or the rear output shaft 5). That is, since the differential mechanism 3 functions as a deceleration mechanism, this running mode is a so-called low speed mode (low mode). When the engine 1 is driven, its driving torque is transmitted to the rear wheels 7 via the input shaft 4 and the rear output shaft 5, so that a large amount of driving force can be generated using both the engine 1 and the motor 2 as driving force sources. It can be in a two-wheel drive state.

(C) of FIG. 10 eliminates the speed reduction function of the differential mechanism 3 by integrating and rotating the entire differential mechanism 3, or converts the differential mechanism 3 into a transmission with a gear ratio of "1". This shows a state in which a so-called high-speed stage (directly coupled stage) mode (high mode) running mode is set. This running mode will be described in comparison with the state shown in FIG. 10(B) described above. The fixed coupling portion 14 is released, and the sleeve 19a is aligned with the three ring gear hubs 13a, the carrier hub 16a and the input hub in the axial direction. 13b, and the operating state of the other connecting portions is the same as the state shown in FIG. 10(B).

Therefore, the differential mechanism 3 rotates as a whole by connecting the carrier 3c and the ring gear 3r. The carrier 3c is connected to the input shaft 4 (or the rear output shaft 5) through the sleeve 19a and the input hub 13b. Therefore, the drive torque output by the motor 2 is transmitted to the rear wheels 7 from the rear output shaft 5 without being increased or decreased through the differential mechanism 3 . That is, the high-speed stage (direct connection stage) mode (or high mode) is entered. Therefore, the motor rotation speed during high vehicle speed can be reduced more than in the low mode, so that the power consumption rate (electricity consumption) can be improved.

In the configuration shown in FIG. 10, the connecting portion for selectively connecting the ring gear 3r, the carrier 3c and the input shaft 4 (or the rear output shaft 5) has a configuration in which parts are shared. Therefore, it is possible to reduce the number of constituent members of the four-wheel drive system as a whole, simplify the structure, and reduce the weight.

FIG. 11 shows an example in which structural members are shared between the fixed connecting portion 14 and the third connecting portion 18 in the structure shown in FIG. 10 to simplify the structure. Specifically, the third connecting portion 18 moves axially with a drive-side hub 18a integrated with the drive sprocket 12a of the chain mechanism 12 and a second carrier hub 18b integrated with the carrier 3c. A sleeve 18c connects these hubs 18a and 18b by connecting them and releases the connection. Further, the sleeve 18c is connected to the sleeve 14b in the fixed connection portion 14 so as to move in the axial direction together with the sleeve 14b. The interval between these sleeves 18c and 14b is an interval that sets the following conditions.

That is, in a state where the sleeve 18c meshes with the drive-side hub 18a and the second carrier hub 18b and the third connecting portion 18 is engaged, the sleeve 14b of the fixed connecting portion 14 is separated from the second ring gear hub 14a and the fixed portion 15. It comes off and the fixed connection part 14 releases. This state is shown in FIG. 11(A).

Further, in a state where the sleeve 14b of the fixed connecting portion 14 is meshed with the second ring gear hub 14a and the fixed portion 15 and the fixed connecting portion 14 is engaged, the sleeve 18c of the third connecting portion 18 is engaged with the driving side hub 18a and the second ring gear hub 18a. The third connecting portion 18 is released from both the carrier hub 18b and the carrier hub 18b. This state is shown in FIG. 11(B).

Furthermore, when the sleeve 18c of the third connecting portion 18 is engaged only with the drive-side hub 18a, the sleeve 14b of the fixed connecting portion 14 is disengaged from the second ring gear hub 14a and the fixed portion 15, and the fixed connecting portion 14 is released. . This state is shown in FIG. 11(C).

Therefore, in the configuration shown in FIG. 11, the actuator for engaging/releasing the fixed connecting portion 14 and the actuator for engaging/releasing the third connecting portion 18 can be shared. By constructing in this manner, the number of constituent members of the four-wheel drive system as a whole can be reduced, and the size and weight of the four-wheel drive system can be reduced.

Although the examples in which the present invention is carried out have been described above, the present invention is of course not limited to the specific examples described above, and the specific configurations of the respective connecting portions may be appropriately replaced, and the motor , the transmission mechanism, or the arrangement or arrangement of the differential mechanism may be changed as appropriate. For example, the differential mechanism 3 may be configured by a double pinion type planetary gear mechanism instead of the so-called single pinion type planetary gear mechanism described above.

Here, the present invention described as the above-mentioned specific examples is listed as follows.

In addition to the configuration described in the claims, a second connection that connects at least two rotating elements in the differential mechanism to integrate the entire differential mechanism when the fixed connection is released. A vehicle four-wheel drive system further comprising: With such a configuration, it is possible to set a so-called high-speed stage (direct coupling stage) or high mode in which the differential mechanism outputs torque without increasing or decreasing it, thereby reducing the rotational speed of the driving force source. Along with this, it is possible to improve the energy efficiency called the fuel consumption of the driving force source and the electricity consumption.

The vehicle four-wheel drive device, wherein the second connecting portion is configured by a frictional engagement mechanism.

A four-wheel drive device for a vehicle, wherein a frictional engagement mechanism that constitutes a second coupling portion is controlled to a slip state to change a limited differential torque of a differential mechanism.

The vehicle four-wheel drive device, wherein the second connecting portion is configured to selectively connect the input element and the output element. With such a configuration, when the entire differential mechanism is integrated, the torque that is input to the differential mechanism is output via the second connecting portion, so the torque applied to the differential mechanism is reduced. As a result, the differential mechanism can be miniaturized.

The vehicle four-wheel drive device, wherein the second connecting portion is configured to selectively connect the sun gear and the ring gear. With such a configuration, the torque applied to the second connecting portion can be reduced, and the size of the second connecting portion can be reduced.

A vehicle four-wheel drive device in which a fixed portion and a fixed connecting portion are arranged on the outer peripheral side of a differential mechanism. With such a configuration, the number of members arranged side by side in the axial direction is reduced, so the axial length, which is the length in the axial direction, can be shortened.

The first connecting portion and the differential mechanism are arranged on the same axis as the first driving force source, and the first connecting portion is arranged on the opposite side of the first driving force source across the differential mechanism. Four-wheel drive system for vehicles.

The second connecting portion and the differential mechanism are arranged on the same axis as the first driving force source, and the second connecting portion is arranged on the opposite side of the first driving force source across the differential mechanism. Four-wheel drive system for vehicles.

A vehicle four-wheel drive device in which an input member is constituted by an input shaft to which power is input from a first driving force source such as an engine, and a differential mechanism is arranged on the same axis as the input shaft.

A four-wheel drive device for a vehicle, further comprising a transmission mechanism that connects an output element and a second output member in the differential mechanism.

The transmission mechanism further includes a third connecting portion that selectively connects the driving side member and the output element, and the driving side member, the output element and the third connecting portion are arranged on the same axis as the first driving force source. In addition, the transmission mechanism is arranged closer to the first driving force source than the third connecting portion. With such a configuration, the transmission mechanism is arranged on the front side of the vehicle, so the axial length of the second output member such as the front output shaft can be shortened.

A four-wheel drive system for a vehicle, wherein a second driving force source and a differential mechanism are arranged on the same axis, and the second driving force source is arranged on the rear side of the vehicle relative to the differential mechanism. With such a configuration, the number of structural members arranged on the front side of the vehicle relative to the differential mechanism is reduced. can be done.

A four-wheel drive device for a vehicle, further comprising: a third connecting portion selectively connecting the output element and the second output member; and a fourth connecting portion selectively connecting the output element and the first output member. . With such a configuration, even when the first driving wheel is driven by the second driving force source, the driving force can be increased by the differential mechanism, and the deceleration action of the differential mechanism does not occur. The rotation speed of the second driving force source can be suppressed or lowered.

A four-wheel drive device for a vehicle, in which any two connecting portions are arranged in an axial direction and adjacent to each other, and a part of constituent members of the two connecting portions are shared by the two connecting portions. With such a configuration, it is possible to reduce the number of constituent members of the four-wheel drive system as a whole, thereby miniaturizing the system.

1 engine 2 motor 2R rotor 3 differential mechanism 3c carrier 3p pinion gear 3r ring gear 3s sun gear 4 input shaft 5 rear output shaft 6, 11 final reduction gear 7 rear wheel 8 rotor shaft 9 front output shaft 10 front wheel 12 chain mechanism 13 connecting portion 13a Ring gear hub 13b Input hub 13c Sleeve 14 Fixed connecting portion 14a Ring gear hub 14b Sleeve 15 Fixed portion 16 Second connecting portion 16a Carrier hub 18 Connecting portion 18a Driving side hub 18b Carrier hub 18c Sleeve 19 Fourth connecting portion 19a Sleeve

Claims (1)

a first driving force source, a second driving force source, a first driving wheel capable of transmitting driving force from the first driving force source, and a second driving wheel capable of transmitting driving force from the second driving force source In a vehicle four-wheel drive system comprising
an input member to which driving torque of the first driving force source is transmitted;
a first output member connected to the input member and configured to output drive torque to the first drive wheel;
An input element to which torque is transmitted from the second driving force source, a fixed element selectively connected to a predetermined fixed portion to stop rotation, and the input element in a state where the fixed element is connected to the fixed portion a differential mechanism comprising at least three rotating elements of the output element that rotates at a reduced speed with respect to the
a second output member that outputs the driving force transmitted from the output element to the second drive wheel;
a first connecting portion that connects the first driving force source and the input element by engaging and disconnects the first driving force source and the input element by disengaging;
a locking connection that engages to connect the locking element to the locking part and releases to disconnect the locking element and the locking part;
The first vehicle that engages the first coupling portion and releases the fixed coupling portion to transmit the driving torque output by the first driving force source to the first driving wheels and the second driving wheels while traveling. In a running mode, the first coupling portion is released and the fixed coupling portion is engaged so that the drive torque output from the second drive force source is amplified by the differential mechanism and applied to the second drive wheel. A four-wheel drive device for a vehicle, characterized in that it is configured so as to be able to set a second running mode in which the power is transmitted to run.

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