JP2011157055A - Transfer of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transfer of a vehicle, which is equipped with an auxiliary transmission mechanism and an output distribution mechanism, and is short in axial total length of the transfer. <P>SOLUTION: In the transfer, the auxiliary transmission mechanism Z1 includes a reduction mechanism Z1a composed of a planetary gear mechanism, and a switching mechanism Z1b. The output distribution mechanism Z2 is composed of a multiplate clutch mechanism. The output distribution mechanism Z2 is disposed to cover the outer periphery of the reduction mechanism Z1a in a radially outward space of the reduction mechanism Z1a. In the reduction mechanism Z1a, a bevel gear is used as a sun gear SG, a planetary gear PG, and an outer gear RG. The sun gear SG and the outer gear RG coaxially rotate around a first output shaft A2, and the planetary gear PG revolves around the first output shaft A2 while rotating around the axis intersecting with the first output shaft A2 as a center axis. Thereby, the transfer is short in the total length and the external form. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention includes a sub-transmission mechanism that selectively switches the ratio of the rotational speed of the output shaft to the rotational speed of the input shaft, and an output distribution mechanism that selectively switches between the two-wheel drive state and the four-wheel drive state. It relates to vehicle transfer.

  Conventionally, a transfer including an auxiliary transmission mechanism and an output distribution mechanism is widely known (see, for example, Patent Document 1). FIG. 10 shows an example of a typical configuration of this type of transfer. In the transfer shown in FIG. 10, a power transmission system is formed between the input shaft A1 connected to the output shaft of the vehicle engine E / G (or automatic transmission A / T) and the rear two wheels of the vehicle. The first output shaft A2 is arranged coaxially with each other. A second output shaft A3, which forms a power transmission system between the two front wheels of the vehicle, is eccentric from the first output shaft A2 and is arranged in parallel with the first output shaft A2.

  This transfer includes an auxiliary transmission mechanism Z1 and an output distribution mechanism Z2. The auxiliary transmission mechanism Z1 includes a speed reduction mechanism Z1a and a switching mechanism Z1b. The speed reduction mechanism Z1a is a planetary gear mechanism including a sun gear SG, a plurality of planetary gears PG, a planetary carrier CA, and an outer gear RG. The sun gear SG is an external gear (spur gear, helical gear, helical gear) that is coaxial with the input shaft A1 and rotates integrally with the input shaft A1. Each planetary gear PG meshes with the sun gear SG and rotates around the first output shaft A2 while rotating around an axis parallel to the first output shaft A2 (a spur gear or a helical gear, Gear). The planetary carrier CA is connected to the central axis of each planetary gear PG and is arranged to rotate coaxially with the first output shaft A2 at a rotational speed equal to the rotational speed of the revolution movement of each planetary gear PG. The outer gear RG meshes with each planetary gear PG and is coaxially connected to the first output shaft A2 and fixed to a housing (not shown) so as not to rotate (spur gear, helical gear, helical gear). It is.

  The switching mechanism Z1b includes a first piece P1 (outer spline) that is coaxial with the first output shaft A2 and rotates integrally with the input shaft A1, a coaxial carrier with the first output shaft A2, and a planetary carrier CA. A second piece P2 (inner spline) arranged to rotate integrally, and a hub H (outer spline) arranged coaxially with the first output shaft A2 and integrally rotated with the first output shaft A2. A sleeve S (outer / inner spline) that is always spline-fitted to the hub H and movable in the direction of the first output shaft A2, and a fork F that adjusts the axial position of the sleeve S. The position of the sleeve S in the axial direction is controlled by driving an actuator (not shown) by the ECU (or manually) to control the position of the fork F.

  In the auxiliary transmission mechanism Z1, as shown in FIG. 11, when the sleeve S is in a position where it is spline-fitted only with the first piece P1 (and the hub H), the first output shaft A2 is at a rotational speed equal to the input shaft A1. A rotating state (HIGH mode) is obtained. On the other hand, as shown in FIG. 12, when the sleeve S is in a position where only the second piece P2 (and the hub H) is spline-fitted, the first output shaft A2 rotates at a rotational speed equal to the rotational speed of the planetary carrier CA. A state in which the first output shaft A2 rotates at a rotational speed lower than the rotational speed of the input shaft A1 (LOW mode). In this manner, in the auxiliary transmission mechanism Z1, the auxiliary transmission function for selectively switching between the HIGH mode and the LOW mode is achieved by controlling the fork F (and hence the axial position of the sleeve S).

  The output distribution mechanism Z2 is a multi-plate clutch mechanism. In the multi-plate clutch mechanism, the maximum torque that can be transmitted (hereinafter referred to as “multi-plate clutch transmission torque”) can be adjusted by controlling an actuator (not shown) by the ECU. When the multi-plate clutch transmission torque is larger than zero (that is, when the multi-plate clutch is in the engaged state), the multi-plate clutch Z2 and the chain are interposed between the first output shaft A2 and the second output shaft A3. Thus, a power transmission system is formed. That is, a four-wheel drive state (4WD mode) in which a power transmission system is formed between the input shaft A1 and the first and second output shafts A2 and A3 is obtained. On the other hand, when the multi-plate clutch transmission torque is zero (that is, when the multi-plate clutch is in a disconnected state), a power transmission system is not formed between the first output shaft A2 and the second output shaft A3. That is, a two-wheel (rear wheel) drive state (2WD mode) in which a power transmission system is formed only between the input shaft A1 and the first output shaft A2 is obtained. As described above, in the output distribution mechanism Z2, by controlling the multi-plate clutch transmission torque, a 2WD / 4WD switching function for selectively switching between the 4WD mode and the 2WD mode is achieved.

  In the transfer shown in FIG. 10, the subtransmission mechanism Z1 and the output distribution mechanism Z2 are coaxial with the first output shaft A2 and adjacent to the axial direction of the first output shaft A2 (overlapping each other in the axial direction). It is arranged so as not to wrap. Therefore, the axial length of the entire transfer is determined based on the sum of the axial length of the auxiliary transmission mechanism Z1 and the axial length of the output distribution mechanism Z2. As a result, there is a problem that the axial length (full length) of the entire transfer is relatively large.

Japanese Patent No. 3650255

  The present invention is for addressing the above-described problems, and an object of the present invention is to provide a vehicle transfer provided with a sub-transmission mechanism and an output distribution mechanism that has a short axial length of the entire transfer. is there.

  The vehicle transfer according to the present invention includes an input shaft (A1) that forms a power transmission system with an output shaft of a power source of the vehicle, and the front two wheels and the rear of the vehicle that are arranged coaxially with the input shaft. A power transmission system is formed between the first output shaft (A2) in which a power transmission system is formed with one of the two wheels and the other of the two front wheels and the rear two wheels of the vehicle. A second output shaft (A3).

  In addition, the transfer includes a speed reduction mechanism (Z1a) that uses the rotation of the input shaft to generate a rotational motion having a rotational speed smaller than the rotational speed of the input shaft, and a rotational speed equal to the rotational speed of the input shaft. A high speed state (HIGH mode) in which the first output shaft rotates and a low speed state (LOW mode) in which the first output shaft rotates at a rotational speed smaller than the rotational speed of the input shaft using the speed reduction mechanism are selected. A sub-transmission mechanism (Z1) including a switching mechanism (Z1b) for switching automatically.

  Furthermore, this transfer is a two-wheel drive state in which a power transmission system is formed only between the input shaft and the first output shaft by not distributing the output of the first output shaft to the second output shaft ( 2WD mode) and a four-wheel drive in which a power transmission system is formed between the input shaft and the first and second output shafts by distributing the output of the first output shaft to the second output shaft An output distribution mechanism (Z2) that selectively switches the state (4WD mode) is provided. Thus, this transfer can achieve both the auxiliary transmission function and the 2WD / 4WD switching function.

  Here, a power transmission system may be formed between the first (second) output shaft and the rear two wheels (front two wheels), or the first (second) output shaft and the front two wheels (rear 2). A power transmission system may be formed with the wheel. The second output shaft is eccentric from the first output shaft and is arranged in parallel with the first output shaft, and a power transmission system between the second output shaft and the output distribution mechanism is provided. A first gear (G1) that rotates integrally with the output distribution mechanism and a second gear (G2) that rotates together with the second output shaft are connected by a chain or a third gear (G3). Is preferred. Thereby, the whole transfer can be constituted compactly.

  The transfer according to the present invention is characterized in that the sub-transmission mechanism is disposed coaxially with the first output shaft, and the output distribution mechanism is arranged in the sub-transmission mechanism in a radially outer space of at least a part of the sub-transmission mechanism. That is, the mechanism is disposed coaxially with the first output shaft so as to cover at least a part of the outer periphery of the mechanism.

  According to this, the output distribution mechanism is disposed so as to overlap with at least a part (or all) of the auxiliary transmission mechanism in the axial direction. Therefore, compared with the transfer shown in FIG. 10 described above (that is, the transfer in which the axial length of the entire transfer is determined based on the sum of the axial lengths of the auxiliary transmission mechanism and the output distribution mechanism). Thus, a transfer having a short axial length (full length) of the entire transfer can be configured.

  Specifically, in the transfer according to the present invention, the speed reduction mechanism and the switching mechanism in the auxiliary transmission mechanism are arranged coaxially with the first output shaft and adjacent to the axial direction of the first output shaft. It is preferable that the output distribution mechanism is disposed so as to cover the outer periphery of the speed reduction mechanism in a space radially outside the speed reduction mechanism of the auxiliary transmission mechanism. Further, the output distribution mechanism is a multi-plate clutch mechanism (Z2), and the friction engagement portion of the multi-plate clutch mechanism is arranged so as to cover the outer periphery of the speed reduction mechanism in a space radially outside the speed reduction mechanism. It is preferred that

  When the output distribution mechanism is disposed in a space radially outside the speed reduction mechanism, the speed reduction mechanism includes a sun gear (SG), a plurality of planetary gears (PG), a planetary carrier (CA), and an outer gear (RG). A planetary gear mechanism composed of In particular, in this case, it is preferable that the speed reduction mechanism, the switching mechanism, and the output distribution mechanism are configured as follows.

  That is, the sun gear is constituted by a bevel gear that is coaxial with the input shaft and rotates integrally with the input shaft, and each planetary gear is engaged with the sun gear and has an axis orthogonal to the first output shaft as a central axis. As a bevel gear that revolves around the first output shaft while rotating, and the planetary carrier is connected to the center shaft of each planetary gear and has a rotational speed equal to the rotational speed of the revolution movement of each planetary gear. The bevel gear is configured to rotate coaxially with the first output shaft and integrally with the first output shaft, and the outer gear is configured with a bevel gear that meshes with each planetary gear and can rotate coaxially with the first output shaft. .

  In addition, the switching mechanism includes a first rotating member (P1) arranged coaxially with the first output shaft and rotating integrally with the outer gear, and coaxial with the first output shaft and the planetary carrier. A second rotating member (P2) arranged to rotate integrally with the first output shaft, a fixing member (H) arranged coaxially and non-rotatably with the first output shaft, the first rotating member, the second A moving member (S) that can be engaged with the rotating member and the fixed member and that changes its engagement state depending on the position; and a control means (F, ECU) that controls the position of the moving member; When the moving member is in the first position, the moving member engages only with the first rotating member and the second rotating member to achieve the high speed state, and the moving member is in the second position. In some cases, the moving member is the first rotating member and The low-speed state is achieved by engaging only serial fixing member. The output distribution mechanism is configured to distribute the output of the first output shaft to the second output shaft via the second rotating member and the planetary carrier. Note that the position of the moving member may be controlled manually or by an actuator.

  Accordingly, a speed reduction mechanism (that is, a planetary gear mechanism) having a smaller radial size (outer diameter) than the speed reduction mechanism shown in FIG. 10 can be configured. Therefore, the radial size (outer diameter) of the output distribution mechanism (multi-plate clutch) covering the outer periphery of the speed reduction mechanism in the space outside the speed reduction mechanism in the radial direction can be reduced. As a result, it is possible to configure a transfer having a small axial size (overall length) and a small radial size (outer diameter).

It is the figure which showed typically the drive system of the vehicle carrying the transfer which concerns on embodiment of this invention. FIG. 2 is a skeleton diagram corresponding to an axial section of the transfer shown in FIG. 1. FIG. 3 is an enlarged view around a switching mechanism shown in FIG. 2 in a HIGH mode. FIG. 3 is an enlarged view around a switching mechanism shown in FIG. 2 in a LOW mode. FIG. 3 is a diagram corresponding to FIG. 2 showing a drive torque transmission path in a HIGH mode. FIG. 3 is a diagram corresponding to FIG. 2 showing a transmission path of drive torque in the LOW mode. It is a skeleton figure corresponding to FIG. 2 of the transfer which concerns on the modification of embodiment of this invention. FIG. 8 is an enlarged view around the output distribution mechanism shown in FIG. 7 in the 4WD mode. FIG. 8 is an enlarged view around the output distribution mechanism shown in FIG. 7 in the 2WD mode. It is a skeleton figure corresponding to the section of the direction of an axis of the conventional transfer. It is an enlarged view around the switching mechanism shown in FIG. 10 in the HIGH mode. It is an enlarged view around the switching mechanism shown in FIG. 10 in the LOW mode.

  A vehicle transfer according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a drive system of a vehicle equipped with a transfer T / F according to an embodiment of the present invention. This transfer T / F includes an input shaft A1, a first output shaft A2, and a second output shaft A3.

  The input shaft A1 is connected to the output shaft of the automatic transmission A / T connected to the engine E / G, and a power transmission system is formed between the input shaft A1 and the output shaft of the automatic transmission A / T. Yes. The first output shaft A2 is connected to the rear two wheels via a differential D / F on the rear wheel side, and a power transmission system is formed between the first output shaft A2 and the rear two wheels.

  The second output shaft A3 is connected to the front two wheels via a differential D / F on the front wheel side, and a power transmission system is formed between the second output shaft A3 and the front two wheels. In addition, as described later, a power transmission system can be formed between the second output shaft A3 and the first output shaft A2 via a gear G3 that connects the gears G1 and G2. Instead of the gear G3, a chain connecting the gears G1 and G2 may be employed.

  This transfer T / F includes an auxiliary transmission mechanism Z1 and an output distribution mechanism Z2. The auxiliary transmission mechanism Z1 has a high speed state (HIGH mode) in which the first output shaft A2 rotates at a rotational speed equal to the rotational speed of the input shaft A1, and the first output shaft A2 at a rotational speed smaller than the rotational speed of the input shaft A1. The “sub-shift function” is selectively switched between a low-speed state (LOW mode) in which the engine rotates. The output distribution mechanism Z2 does not distribute the output of the first output shaft A2 to the second output shaft A3, thereby forming a power transmission system between the input shaft A1 and the first output shaft A2 (rear wheel). ) A power transmission system is formed between the input shaft A1 and the first and second output shafts A2 and A3 by distributing the output of the first output shaft A2 to the second output shaft A3 and the driving state (2WD mode). The “2WD / 4WD switching function” is selectively switched between the four-wheel drive state (4WD mode). The auxiliary transmission mechanism Z1 and the output distribution mechanism Z2 are controlled by the electronic control unit ECU. Hereinafter, a specific configuration of the transfer T / F will be described with reference to FIG.

(Constitution)
As shown in FIG. 2, in this transfer T / F, an input shaft A1 and a first output shaft A2 are a plurality of bearings (or bushes) fixed to a housing (not shown), etc. (not shown). ) Are supported so as to be rotatable coaxially with each other. The second output shaft A3 is eccentric from the first output shaft A2 and parallel to the first output shaft A2 by a plurality of bearings (or bushes) or the like (not shown) fixed to the housing (not shown). Is rotatably supported.

  The subtransmission mechanism Z1 of the transfer T / F includes a speed reduction mechanism Z1a and a switching mechanism Z1b. The speed reduction mechanism Z1a and the switching mechanism Z1b are arranged coaxially with the first output shaft A2 and adjacent to the axial direction of the first output shaft A2 (so as not to overlap each other in the axial direction).

  The speed reduction mechanism Z1a is a planetary gear mechanism including a sun gear SG, a plurality of planetary gears PG, a planetary carrier CA, and an outer gear RG. The sun gear SG is formed of a “bevel gear” that is coaxial with the input shaft A1 and rotates integrally with the input shaft A1. Each planetary gear PG is configured by a “bevel gear” that revolves around the first output shaft A2 while meshing with the sun gear SG and rotating around an axis orthogonal to the first output shaft A2.

  The planetary carrier CA is connected to the central axis of each planetary gear PG, and rotates coaxially with the first output shaft A2 and integrally with the first output shaft at a rotational speed equal to the rotational speed of the revolution movement of each planetary gear PG. It is configured. The outer gear RG is configured by a “bevel gear” that meshes with each planetary gear PG and can rotate coaxially with the first output shaft A2.

  The switching mechanism Z1b includes a first piece P1 (corresponding to the “first rotating member”), a second piece P2 (corresponding to the “second rotating member”), a hub H (corresponding to the “fixing member”), and a sleeve. S (corresponding to the “moving member”) and a fork F (corresponding to the “control means”).

  The first piece P1 is configured to rotate coaxially with the first output shaft A2 and integrally with the outer gear RG. The second piece P2 is configured to be coaxial with the first output shaft A2 and rotate integrally with the planetary carrier CA. The hub H is fixed to a housing (not shown) coaxially and non-rotatably with the first output shaft A2. Outer splines are formed coaxially with respect to the first output shaft A2 on the cylindrical outer peripheral portions of the first piece P1, the second piece P2, and the hub H, respectively.

  The sleeve S has a cylindrical shape, and an inner spline is formed on the cylindrical inner periphery of the sleeve S. The sleeve S is always spline-fitted to the first piece P1 and is movable in the direction of the first output shaft A2. Depending on the axial position of the sleeve S, the sleeve S can be splined to the second piece P2 and the hub H. An inner spline is formed coaxially with the first output shaft A2 at the cylindrical inner peripheral portion of the second piece P2, and an outer spline is formed at the cylindrical outer peripheral portion of the sleeve S. You may be comprised so that spline fitting with 2 piece P2 is attained.

  The fork F is engaged with the sleeve S and is movable in the direction of the first output shaft A2. By adjusting the axial position of the fork F, the axial position of the sleeve S can be controlled. The axial position of the fork F is adjusted by an actuator (not shown).

  The output distribution mechanism Z2 of the transfer T / F is disposed so as to cover the outer periphery of the speed reduction mechanism Z1a in the space radially outside the speed reduction mechanism Z1a (so as to overlap the speed reduction mechanism Z1a in the axial direction). The output distribution mechanism Z2 is a multi-plate clutch mechanism. Specifically, the output distribution mechanism Z2 includes a member M1, an input side engagement member M2, an output side engagement member M3, and a member M4.

  The member M1 has a hollow disk shape and is configured to rotate coaxially with the first output shaft A2 and integrally with the second piece P2. The member M4 has a disk shape and is configured to rotate coaxially with the first output shaft A2 and integrally with the gear G1. The rotation of the gear G1 is transmitted to the second output shaft A3 via the gear G3 (or chain) and the gear G2. The gears G1 and G2 have the same number of teeth. Therefore, the gear G1 and the second output shaft A3 rotate at the same rotational speed.

  The input side engaging member M2 has a cylindrical shape, and is configured to rotate coaxially with the first output shaft A2 and integrally with the member M1. The input side engaging member M2 is disposed so as to cover the outer periphery of the speed reduction mechanism Z1a in a space radially outside the speed reduction mechanism Z1a (so as to overlap the speed reduction mechanism Z1a in the axial direction). A plurality of input side frictional engagement portions extending radially outward (perpendicular to the first output shaft A2) are provided on the cylindrical outer surface of the input side engagement member M2 in the axial direction of the first output shaft A2. It is formed so as to be arranged at a predetermined interval.

  The output side engaging member M3 has a cylindrical shape, and is configured to rotate coaxially with the first output shaft A2 and integrally with the member M4. The output side engagement member M3 covers the outer periphery of the input side engagement member M2 in a space radially outside the input side engagement member M2 (so as to overlap the input side engagement member M2 in the axial direction). Has been placed. A plurality of output side frictional engagement portions extending radially inward (perpendicular to the first output shaft A2) are provided on the inner surface of the cylindrical surface of the output side engagement member M3 in the axial direction of the first output shaft A2. It is formed so as to be arranged at a predetermined interval.

  The plurality of output side friction engagement portions of the output side engagement member M3 can be engaged with the plurality of input side friction engagement portions of the input side engagement member M2, respectively. The maximum torque that can be transmitted between the input-side and output-side engagement members M2 and M3 (thus, between the first and second output shafts A2 and A3) by these engagements (hereinafter referred to as "multi-plate clutch transmission torque"). .) Can be adjusted by adjusting the relative position in the axial direction between the input side / output side engaging members M2, M3 by an actuator (not shown). Hereinafter, the case where the multi-plate clutch transmission torque is greater than zero is referred to as “connected state”, and the case where the multi-plate clutch transmission torque is zero is referred to as “divided state”.

  The electronic control unit ECU determines the state (position) of the operation member (lever, etc.) for achieving the “sub-shift function” and the “2WD / 4WD switching function” operated by the driver, the traveling state of the vehicle, etc. Accordingly, the relative position between the actuator for adjusting the position of the fork F (and hence the sleeve S) in the auxiliary transmission mechanism Z1 and the input side / output side engaging members M2 and M3 in the output distribution mechanism Z2 is adjusted. Thus, the actuator (which adjusts the multi-plate clutch transmission torque) is controlled.

(Operation)
Next, the operation of the transfer T / F configured as described above will be described. The axial position of the sleeve S is selectively adjusted to one of the two positions shown in FIGS. Hereinafter, it demonstrates in order.

  When the axial position of the sleeve S is adjusted to the position shown in FIG. 3 (first position), the sleeve S is spline-fitted only with the first and second pieces P1, P2. Hereinafter, this state is referred to as “HIGH mode”. On the other hand, when the axial position of the sleeve S is adjusted to the position shown in FIG. 4 (second position), the sleeve S is spline-fitted only with the first piece P1 and the hub H. Hereinafter, this state is referred to as “LOW mode”.

<HIGH mode>
In the HIGH mode, the rotation speeds of the first and second pieces P1 and P2 are equal. That is, the plurality of planetary gears PG revolve without rotating with respect to the rotation of the sun gear SG. Therefore, the revolution speeds of the plurality of planetary gears PG (= the rotation speed of the planetary carrier CA) coincide with the rotation speed of the sun gear SG. As a result, the first output shaft A2 rotates at a rotational speed equal to the rotational speed of the input shaft A1.

  In the HIGH mode, as indicated by a thick arrow (solid line) in FIG. 5, the power (A1 → SG → PG → CA → A2) between the engine E / G and the rear two wheels in the transfer T / F. A transmission system is formed. On the other hand, between the engine E / G and the front two wheels, the power transmission system is not formed when the output distribution mechanism (multi-plate clutch) Z2 is in the disconnected state, and when the output distribution mechanism Z2 is in the joined state, (A1-> SG-> PG-> CA-> P2-> M1-> M2-> M3-> M4-> G1-> G3 (or chain)-> G2-> A3) (see the thick arrow (broken line) in FIG. 5) ). That is, when the output distribution mechanism Z2 is in the divided state, the rear wheel drive state (two-wheel drive state) in the HIGH mode is obtained (HIGH + 2WD mode (H2 mode)). On the other hand, when the output distribution mechanism Z2 is in the joined state, a four-wheel drive state in the HIGH mode is obtained (HIGH + 4WD mode (H4 mode)).

<LOW mode>
In the LOW mode, the first piece P1 does not rotate. That is, the plurality of planetary gears PG revolve while rotating with respect to the rotation of the sun gear SG. Therefore, the revolution speed of the plurality of planetary gears PG (= the rotation speed of the planetary carrier CA) is smaller than the rotation speed of the sun gear SG. As a result, the first output shaft A2 rotates at a rotational speed smaller than the rotational speed of the input shaft A1.

  In the LOW mode, as indicated by a thick arrow (solid line) in FIG. 6, power (A1 → SG → PG → CA → A2) between the engine E / G and the rear two wheels in the transfer T / F. A transmission system is formed. On the other hand, between the engine E / G and the front two wheels, the power transmission system is not formed when the output distribution mechanism Z2 is in the divided state, and when the output distribution mechanism Z2 is in the joined state (A1 → SG → A power transmission system of PG-> CA-> P2-> M1-> M2-> M3-> M4-> G1-> G3 (or chain)-> G2-> A3) is formed (see the thick arrow (broken line) in FIG. 6). That is, when the output distribution mechanism Z2 is in the divided state, the rear wheel drive state (two-wheel drive state) in the LOW mode is obtained (LOW + 2WD mode (L2 mode)). On the other hand, when the output distribution mechanism Z2 is in the joined state, a four-wheel drive state in the LOW mode is obtained (LOW + 4WD mode (L4 mode)).

(Action / Effect)
As described above, in the transfer T / F according to the embodiment of the present invention described above, the output distribution mechanism (multi-plate clutch mechanism) Z2 is located in the radially outer space of the speed reduction mechanism (planetary gear mechanism) Z1a of the auxiliary transmission mechanism Z1. It arrange | positions so that the outer periphery of the deceleration mechanism Z1a may be covered. In other words, the output distribution mechanism Z2 is disposed so as to overlap the speed reduction mechanism Z1a in the axial direction. Therefore, the above-described conventional transfer shown in FIG. 10 (that is, a transfer in which the axial length of the entire transfer is determined based on the sum of the axial lengths of the auxiliary transmission mechanism and the output distribution mechanism) Compared to the above, it is possible to configure a transfer in which the entire axial length (full length) of the transfer is short.

  The following is a supplementary explanation. In the output distribution mechanism (multi-plate clutch mechanism) Z2 in the conventional transfer shown in FIG. 10, a plurality of disk-shaped plates that are coaxial with the first output shaft A2 and rotate integrally with the first output shaft A2 are the first output. It is formed so as to be arranged at a predetermined interval in the axial direction of the axis A2. An input side frictional engagement portion that engages with the output side frictional engagement portion is formed in the vicinity of the outer periphery of each plate. That is, each plate has a function of forming a power transmission system between the first output shaft A2 and the input side frictional engagement portion. Thus, since a plurality of plates are continuously present in the radial direction from the first output shaft A2 in the output distribution mechanism Z2, a sufficient free space cannot be secured.

  On the other hand, in the transfer T / F according to the embodiment of the present invention shown in FIG. 2, the functions of the plurality of plates (a power transmission system is formed between the first output shaft A2 and the input side frictional engagement portion). In place of the plurality of plates, a hollow disk-shaped member M1 and a cylindrical input-side engagement member M2 are employed as members that exhibit the same function as the above-described function. As a result, there are no members present continuously in the radial direction from the first output shaft A2 in the output distribution mechanism Z2, and a sufficient free space is secured. In the present embodiment, the speed reduction mechanism Z1a is accommodated in this sufficient empty space. That is, by effectively utilizing this sufficient free space, the axial length (full length) of the entire transfer is shortened.

  Further, in the speed reduction mechanism (planetary gear mechanism) Z1a in the transfer shown in FIG. 10, the outer gear RG exists at the radially outermost portion of the speed reduction mechanism Z1a. The outer gear RG is fixed to a housing (not shown). Therefore, in this transfer, it is very difficult to dispose another mechanism in the space outside in the radial direction of the speed reduction mechanism Z1a.

  On the other hand, in the transfer T / F according to the embodiment of the present invention shown in FIG. 2, the hub H which is a member for fixing the outer gear RG (to make it non-rotatable) It is arranged at a position offset in the axial direction from the space. Therefore, it is easy to arrange another mechanism in the space on the radially outer side of the speed reduction mechanism Z1a. This also greatly contributes to realizing a configuration in which the output distribution mechanism Z2 is arranged in a space radially outside the speed reduction mechanism Z1a.

  In addition, in the speed reduction mechanism Z1a of the transfer T / F according to the embodiment of the present invention, “bevel gears” are used as the sun gear SG, the planetary gear PG, and the outer gear RG. In addition, the sun gear SG and the outer gear RG rotate coaxially with the first output shaft A2, and the planetary gear PG rotates around the first output shaft A2 while rotating around an axis orthogonal to the first output shaft A2. Revolving structure is adopted.

  With such a configuration, the speed reduction mechanism Z1a having a very small size (outer diameter) in the radial direction can be configured as compared with the speed reduction mechanism in the transfer shown in FIG. Therefore, the radial size (outer diameter) of the output distribution mechanism (multi-plate clutch mechanism) Z2 that covers the outer periphery of the speed reduction mechanism Z1a in the space radially outside the speed reduction mechanism Z1a can be reduced. As a result, it is possible to configure a transfer having a small axial size (overall length) and a small radial size (outer diameter).

  The present invention is not limited to the above embodiment, and various modifications can be employed within the scope of the present invention. For example, in the above-described embodiment, the rear wheel drive state is adopted as the two-wheel drive state. On the other hand, the front wheel drive state may be adopted as the two-wheel drive state. In this case, a power transmission system may be formed between the first output shaft A2 and the front two wheels, and a power transmission system may be formed between the second output shaft A3 and the rear two wheels.

  In the above embodiment, the second output shaft A3 is eccentric from the first output shaft A2 and is arranged in parallel with the first output shaft A2. However, the second output shaft A3 is in relation to the first output shaft A2. Need not be parallel. In the above embodiment, the speed reduction mechanism Z1a is provided with two shift stages, but may be provided with three or more shift stages.

  In the above embodiment, the output distribution mechanism Z2 is arranged so as to cover only the outer periphery of the speed reduction mechanism Z1a of the subtransmission mechanism Z1 (so as not to cover the outer periphery of the switching mechanism Z1b of the subtransmission mechanism Z1). The output distribution mechanism Z2 may be disposed so as to cover both the outer periphery of the speed reduction mechanism Z1a and the switching mechanism Z1b of the auxiliary transmission mechanism Z1. Moreover, in the said embodiment, although the planetary gear mechanism is employ | adopted as the deceleration mechanism Z1a, another mechanism may be employ | adopted as the deceleration mechanism Z1a.

  In the above embodiment, a multi-plate clutch mechanism is employed as the output distribution mechanism Z2. However, as the output distribution mechanism Z2, a dog type (spline fitting type) is used instead of the multi-plate clutch mechanism as in the switching mechanism Z1b. ) Switching mechanism may be employed. Alternatively, as shown in FIG. 7, a dog type (spline fitting type) switching mechanism may be adopted as the output distribution mechanism Z2 in addition to the multi-plate clutch mechanism.

  The transfer shown in FIG. 7 is shown in FIG. 2 only in the point that the second piece P2 and the member M1 are separated and can be rotated independently, and that the sleeve S2 and the fork F2 are added. Different from transfer. Only such differences will be described below.

  The sleeve S2 has a cylindrical shape, and an inner spline is formed on the cylindrical inner peripheral portion of the sleeve S2. The sleeve S2 is always spline-fitted to the member M1 and is movable in the direction of the first output shaft A2. Depending on the axial position of the sleeve S2, the sleeve S2 can be splined with the second piece P2.

  The fork F2 is engaged with the sleeve S2 and is movable in the direction of the first output shaft A2. The axial position of the sleeve S2 can be controlled by adjusting the axial position of the fork F2. The axial position of the fork F2 is adjusted by an actuator (not shown).

  The axial position of the sleeve S2 is selectively adjusted to one of the two positions shown in FIGS. When the axial position of the sleeve S2 is adjusted to the position (first position) shown in FIG. 8, the sleeve S2 is spline-fitted with the member M1 and the second piece P2. Hereinafter, this state is referred to as “4WD mode”. In the 4WD mode, the rear wheel drive state (two-wheel drive state) is obtained when the multi-plate clutch mechanism is in the disconnected state, and the four-wheel drive state is obtained when the multi-plate clutch mechanism is in the engaged state.

  On the other hand, when the axial position of the sleeve S2 is adjusted to the position (second position) shown in FIG. 9, the sleeve S2 is spline-fitted only with the member M1. Hereinafter, this state is referred to as “2WD mode”. In the 2WD mode, only the rear wheel drive state (two-wheel drive state) can be obtained regardless of the state of the multi-plate clutch mechanism.

  In addition, in the above embodiment, the axial position of the fork F (and hence the sleeve S) is controlled by an actuator that operates according to a command from the electronic control unit ECU. Etc.) and the fork F are mechanically connected by a link or the like, the axial position of the fork F may be manually controlled by operating the operation member.

  E / G ... engine, A / T ... automatic transmission, T / F ... transfer, Z1 ... sub-transmission mechanism, Z1a ... deceleration mechanism, Z1b ... switching mechanism, Z2 ... output distribution mechanism, A1 ... input shaft, A2 ... first 1 output shaft, A3 ... 2nd output shaft, SG ... sun gear, PG ... planetary gear, CA ... planetary carrier, RG ... outer gear, P1 ... 1st piece, P2 ... 2nd piece, H ... hub, S ... sleeve, F ... Fork, M1 ... member, M2 ... input side engaging member, M3 ... output side engaging member, M4 ... member, ECU ... electronic control unit

Claims (6)

An input shaft (A1) that forms a power transmission system with the output shaft of the power source of the vehicle;
A first output shaft (A2) disposed coaxially with the input shaft and forming a power transmission system between one of the front two wheels and the rear two wheels of the vehicle;
A second output shaft (A3) in which a power transmission system is formed between the other of the front two wheels and the rear two wheels of the vehicle;
A speed reduction mechanism (Z1a) that generates a rotational motion at a rotational speed smaller than the rotational speed of the input shaft by utilizing the rotation of the input shaft, and the first output shaft at a rotational speed equal to the rotational speed of the input shaft. A switching mechanism that selectively switches between a rotating high speed state (HIGH mode) and a low speed state (LOW mode) in which the first output shaft rotates at a rotational speed smaller than the rotational speed of the input shaft using the speed reduction mechanism ( Z1b), a subtransmission mechanism (Z1),
A two-wheel drive state (2WD mode) in which a power transmission system is formed only between the input shaft and the first output shaft by not distributing the output of the first output shaft to the second output shaft; and A four-wheel drive state (4WD mode) in which a power transmission system is formed between the input shaft and the first and second output shafts by distributing the output of the first output shaft to the second output shaft. An output distribution mechanism (Z2) for selectively switching;
In the transfer of vehicles with
The auxiliary transmission mechanism is arranged coaxially with the first output shaft,
The output distribution mechanism is a vehicle disposed coaxially with the first output shaft so as to cover an outer periphery of at least a part of the auxiliary transmission mechanism in a radially outer space of at least a part of the auxiliary transmission mechanism. Transfer. In the transfer of the vehicle according to claim 1,
The speed reduction mechanism and the switching mechanism in the auxiliary transmission mechanism are arranged coaxially with the first output shaft and adjacent to the axial direction of the first output shaft,
The output distribution mechanism is a vehicle transfer arranged so as to cover an outer periphery of the speed reduction mechanism in a space radially outside the speed reduction mechanism of the auxiliary transmission mechanism. In the transfer of the vehicle according to claim 2,
The output distribution mechanism is a multi-plate clutch mechanism (Z2), and a friction engagement portion of the multi-plate clutch mechanism is disposed so as to cover an outer periphery of the speed reduction mechanism in a space radially outside the speed reduction mechanism. , Vehicle transfer. In the transfer of the vehicle according to claim 2 or claim 3,
The speed reduction mechanism is a vehicle transfer, which is a planetary gear mechanism including a sun gear (SG), a plurality of planetary gears (PG), a planetary carrier (CA), and an outer gear (RG). The vehicle transfer according to claim 4,
The sun gear is constituted by a bevel gear that is coaxial with the input shaft and rotates integrally with the input shaft,
Each planetary gear is constituted by a bevel gear that revolves around the first output shaft while meshing with the sun gear and rotating around an axis orthogonal to the first output shaft as a central axis,
The planetary carrier is connected to a central axis of each planetary gear and is configured to rotate coaxially with the first output shaft and integrally with the first output shaft at a rotational speed equal to the rotational speed of the revolution movement of each planetary gear. And
The outer gear is constituted by a bevel gear that meshes with each planetary gear and is rotatable coaxially with the first output shaft.
The switching mechanism is
A first rotating member (P1) arranged coaxially with the first output shaft and rotating integrally with the outer gear;
A second rotating member (P2) coaxial with the first output shaft and arranged to rotate integrally with the planetary carrier;
A fixing member (H) disposed coaxially and non-rotatably with the first output shaft;
A movable member (S) that is engageable with the first rotating member, the second rotating member, and the fixed member, and whose engagement state changes according to the position;
Control means (F, ECU) for controlling the position of the moving member;
With
When the moving member is in the first position, the moving member engages only with the first rotating member and the second rotating member to achieve the high speed state,
When the moving member is in the second position, the moving member engages only with the first rotating member and the fixed member to achieve the low speed state,
The output distribution mechanism is a vehicle transfer configured to distribute the output of the first output shaft to the second output shaft via the second rotating member and the planetary carrier. In the transfer of the vehicle according to any one of claims 1 to 5,
The second output shaft is eccentric from the first output shaft and is disposed in parallel with the first output shaft,
The power transmission system between the second output shaft and the output distribution mechanism includes a first gear (G1) that rotates integrally with the output distribution mechanism and a second gear (G2) that rotates together with the second output shaft. ) With a chain or a third gear (G3).

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