JP3130994B2 - Vehicle transfer device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer apparatus for a vehicle in which power from a main transmission is switched between high and low speeds by a meshing clutch and two-wheel / four-wheel drive is switched.

[0002]

2. Description of the Related Art Conventionally, a transfer device has conventionally been provided with a sub-transmission that constantly transmits power from a main transmission to an input shaft to a main output shaft by switching between high and low speeds by a meshing clutch. There is known a configuration in which a two-wheel / four-wheel drive switching mechanism is provided for drivingly coupling the four-wheel drive. A two-wheel / four-wheel drive switching mechanism that appropriately couples a sub-output shaft to a main output shaft is disclosed in Japanese Patent Application Laid-Open No. 56-39352 when switching response and reduction of switching shock are taken into consideration. It is advantageous to use a hydraulic or electromagnetic friction clutch instead of the dog clutch.

[0003]

In this type of transfer apparatus, when the operating system of the friction clutch constituting the two-wheel / four-wheel drive switching mechanism breaks down, the clutch cannot be engaged and the four-wheel drive state is lost. The vehicle cannot be selected, and the vehicle must run in a two-wheel drive state.

The present invention solves the above-mentioned problem by setting an emergency four-wheel drive position capable of achieving a four-wheel drive state irrespective of a friction clutch in a dog clutch in addition to a normal high-speed position and a low-speed position. Aim.

[0005]

To this end, the two transfer devices according to the present invention comprise a sub-transmission which transmits power to an input shaft to a main output shaft by switching between high and low speeds by a meshing clutch, and a sub-output shaft. In a transfer apparatus for a vehicle, comprising a two-wheel / four-wheel drive switching mechanism having a friction clutch, which is appropriately coupled to the main output shaft as a main element, coaxially adjacent to a high / low speed switching mesh clutch of the sub-transmission, A sub output shaft side member that rotates together with the sub output shaft is provided, and the high / low speed switching mesh clutch is
Apart from the high-speed position and the low-speed position, an emergency four-wheel drive position is also set in which the main output shaft and the sub-output shaft side members are also drivingly connected while the input shaft and the main output shaft are drivingly connected. Things.

[0006]

The auxiliary transmission switches the power from the input shaft between high speed and low speed in accordance with the selected position of the dog clutch, and transmits the power to the main output shaft to drive the two wheels to be driven constantly, and the two-wheel to four-wheel. The drive switching mechanism appropriately connects the auxiliary output shaft to the main output shaft by means of a friction clutch, and sets the four-wheel drive state in which the other two wheels can be driven by the auxiliary output shaft.

When the four-wheel drive state cannot be obtained by the two-wheel / four-wheel drive switching mechanism due to the failure of the operation system of the friction clutch, the dog clutch is set to the emergency four-wheel drive position. At this time, while the input clutch and the main output shaft are drive-coupled between the input shaft and the main output shaft, a sub-output shaft side member provided coaxially adjacent to the high / low speed switching dog clutch so as to rotate together with the sub-output shaft is drive-coupled to the main output shaft. I do. As a result, even if the friction clutch of the two-wheel / four-wheel drive switching mechanism cannot be engaged, the high / low speed switching meshing clutch enables four-wheel drive and avoids a situation in which four-wheel drive cannot be disabled. it can.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of a transfer apparatus according to the present invention. Reference numeral 1 denotes a transfer case, in which an input shaft 2 and a main output shaft 3 are arranged in a coaxial butting relationship in a transfer case 1 and are rotatably supported. The auxiliary output shaft 4 is arranged in parallel with the shafts 2 and 3. The input shaft 2 is connected to an output shaft 5 of a main transmission (not shown), the main output shaft 3 is connected to two differential gears that are to be driven at all times of the vehicle, and the sub output shaft 4 is to be driven appropriately for the vehicle.
Connect to the differential gear of the wheel.

An auxiliary transmission 6 and a two-wheel / four-wheel drive switching mechanism 7 are provided on the input shaft 2 and the main output shaft 3. The auxiliary transmission 6 is a simple planetary gear set including a sun gear 8S formed on the input shaft 2, an internal ring gear 8R fixed in the transfer case 1, and a carrier 8C rotatably supporting a pinion 8P meshing with the sun gear 8S. 8 is a main component, and is provided coaxially with a high / low speed switching mechanism 9 described below.

The high / low speed switching mechanism 9 is of the dog clutch type which is manually operated by the driver, and has a hub 9B coupled on the main output shaft 3, a coupling sleeve 9C slidably engaged with the hub 9B, and a coupling sleeve 9C. A clutch gear 9 integrally formed with the input shaft 2 such that the ring sleeve 9C meshes with the internal teeth at a high speed position H indicated by a solid line in the upper half of the figure.
H and the carrier 8C such that the coupling sleeve 9C is engaged with the external teeth at the low speed position L indicated by the solid line in the lower half of the figure.
And the clutch gear 9L provided in the above.

The two-wheel / four-wheel drive switching mechanism 7 includes a friction clutch 10 as a main component and its clutch hub 10.
H is rotatably supported on the main output shaft 3, and is driven and connected to the sub output shaft 4 via the sprocket 11, the chain 12, and the sprocket 13 in a winding transmission relationship. A clutch drum 10D of the friction clutch 10 is drivingly connected to the main output shaft 3, and a piston 10P is fitted in the drum 10D. When the hydraulic pressure of the piston 10P is actuated, the friction clutch 10 moves between the clutch hub 10H and the clutch drum 10D.
Accordingly, the main output shaft 3 and the sub output shaft 4 are drive-coupled to each other so that power can be taken out not only from the main output shaft 3 but also from the sub output shaft 4 as appropriate.

In this embodiment, in particular, a clutch gear 14 serving as a sub-output shaft side member is connected to the clutch hub 10H of the friction clutch 10 side by side with the sprocket 11, and the clutch gear 14 is coaxially adjacent to the coupling sleeve 9C. Deploy. In the emergency four-wheel drive position E indicated by a two-dot chain line in the lower half of the coupling sleeve 9C in the figure, the clutch gear 14 is appropriately arranged and the internal teeth of the coupling sleeve 9C mesh with the external teeth of the clutch gear 14. Have an appropriate diameter. The emergency four-wheel drive position E is defined as a high-speed position H, a low-speed position L, and a neutral position N (shown by a two-dot chain line in the upper half of the figure) which are normally set in the coupling sleeve 9C. Separately, the coupling sleeve 9C is set adjacent to the outside of the low-speed position L.
Are kept engaged with the clutch gear 9L.

The operation of the above embodiment will now be described. The power from the main transmission output shaft 5 is directly input to the auxiliary transmission input shaft 2 on the one hand, and is reduced by the planetary gear set 8 to the carrier 8C on the other hand. Thus, when the coupling sleeve 9C is at the neutral position N, the coupling sleeve 9C does not mesh with any of the clutch gears 9H and 9L.
Power is not transmitted to main output shaft 3. Of course, no power is transmitted to the sub output shaft 4, so that all wheels are not driven.

When the coupling sleeve 9C is set at the H position, the coupling sleeve 9C is connected to the hub 9B.
Sliding upward engages the clutch gear 9H. At this time, the power from the input shaft 2 directly passes through the clutch gear 9H and the hub 9B to reach the main output shaft 3, and drives the constantly driven wheels related to the main output shaft 3 at high speed. And friction clutch 1
0 is not connected by the hydraulic operation of the piston 10P,
When the high-speed two-wheel drive state is established and the friction clutch 10 is connected by hydraulic operation of the piston 10P, the sub-output shaft 4 is drivingly connected to the main output shaft 3, and power is also output from the sub-output shaft 4, and the other two wheels are driven. Also, a high-speed four-wheel drive state in which high-speed driving is performed can be obtained.

When the coupling sleeve 9C is set to the L position, the coupling sleeve 9C is connected to the clutch gear 9L.
The main output shaft 3 is coupled to the carrier 8C that is being driven at a reduced speed, and the driving wheels are constantly driven at a low speed. At this time, the friction clutch 10 is connected by hydraulic operation of the piston 10P,
The auxiliary output shaft 4 is drive-coupled to the main output shaft 3 to drive the other two wheels at a low speed to obtain a low-speed four-wheel drive state. In most cases, there is no need to set the two-wheel drive at the low speed position, and the friction clutch 10 is always engaged at the low speed position L.

By the way, when the friction clutch 10 is disengaged due to the failure of the operating system and cannot perform four-wheel drive at all, the driver sets the coupling sleeve 9C to the emergency four-wheel drive position E. In this position the coupling sleeve 9
C is the clutch gear 14 while meshing with the clutch gear 9L.
And the main output shaft 3 and the sub output shaft 4 are drive-coupled separately from the friction clutch 10. Therefore, the friction clutch 1
Even if 0 cannot be connected due to a failure of the operating system and four-wheel drive cannot be obtained in this case, the engagement of the coupling sleeve 9C and the clutch gears 9L and 14 can secure four-wheel drive at least in the low-speed transmission state. Thus, it is possible to avoid a situation in which four-wheel drive cannot be performed at all.

In this embodiment, an existing coupling sleeve 9C is used in order to achieve this effect, and the clutch sleeve 14 is merely added with a clutch gear 14 for meshing at the newly installed emergency four-wheel drive position E. Since the object is achieved only by a simple configuration change, it is very advantageous in terms of cost.

[0018]

As described above, the transfer apparatus of the present invention is coaxially adjacent to the high / low speed switching meshing clutch 9 of the subtransmission 6 and rotates with the suboutput shaft 4 in the suboutput shaft side member. 14 is provided, and the main output shaft 3 and the sub output shaft side member 14 are connected to the high / low speed switching dog clutch 9 while the input shaft 2 and the main output shaft 3 are driven and connected separately from the high speed position and the low speed position. Is also configured to set the emergency four-wheel drive position E to be drive-coupled.
Even if the friction clutch 10 of the wheel-four-wheel drive switching mechanism 7 is disengaged due to a failure of the operation system, the four-wheel drive state can be ensured by operating the dog clutch 9 to the emergency four-wheel drive position E, It is possible to avoid a situation in which the four-wheel drive is completely disabled and the vehicle must be driven in the two-wheel drive state.

Further, since the two-wheel drive is not set at the low-speed position L as described above, the two-wheel drive is mechanically coupled between the main output shaft 3 and the sub-output shaft 4 at the low-speed position L of the dog clutch 9 to cause friction. The four-wheel drive state is always achieved regardless of the clutch 10, and even if the operation system of the friction clutch 10 fails and the clutch 10 cannot be connected, the four-wheel drive state can be obtained at the minimum low speed position. However, in this case, when the coupling sleeve 9 is switched to the low speed position, the coupling sleeve 9 is simultaneously engaged and meshed at two positions of the low speed selection clutch gear and the four-wheel drive selection clutch gear, resulting in poor operability. On the other hand, according to the present invention, the above-described effects can be achieved without causing such a problem at all.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of a transfer device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transfer case 2 Input shaft 3 Main output shaft 4 Sub output shaft 5 Main transmission output shaft 6 Sub transmission 7 Two-wheel / four-wheel drive switching mechanism 8 Simple planetary gear set 9 High / low speed switching mechanism (mesh clutch) 10 Friction clutch 11 Sprocket 12 Chain 13 Sprocket 14 Clutch gear (Sub output shaft side member)

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-56-39352 (JP, A) JP-A-64-4538 (JP, A) JP-A-2-267031 (JP, A) 129926 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60K 23/00-23/08 B60K 17/28-17/36

Claims (1)

(57) [Claims] 1. A two-wheel drive having a sub-transmission that transmits power to an input shaft to a main output shaft by switching between high and low speeds by a meshing clutch and a friction clutch for drivingly coupling the sub-output shaft to the main output shaft. A vehicle output device having a four-wheel drive switching mechanism, wherein a sub-output shaft-side member that rotates together with the sub-output shaft is provided coaxially adjacent to a high / low speed switching meshing clutch of the sub-transmission. Emergency four-wheel drive for driving and connecting the main output shaft and the sub-output shaft side member to the low-speed switching dog clutch separately from the high-speed position and the low-speed position while drivingly connecting the input shaft and the main output shaft. A transfer device for a vehicle, wherein a position is set.