JPS62273125A - Drive unit for automobile - Google Patents

Abstract

PURPOSE:To effectively absorb energy in a collision, by supporting the middle part of a propeller shaft with an intermediate shaft bearing and providing a shaft miniaturizing means for shortening the shaft length on the propeller shaft in the front part. CONSTITUTION:A propeller shaft 22 is composed of three universal coupling 22a-22c, and the middle universal coupling 22b unites a front shaft body 26 with a rear shaft body 28. The front shaft body 26 unites a shaft 26a with a hollow shaft 26b by means of a spline coupling part 26c, and when any force is applied in the shaft direction, it is possible to relatively slide and displace in the shaft direction. Thus, when any targo force is applied from the front to the front shaft body 26, the rear end of the shaft 26a is inserted into the hollow shaft 26b so as to shorten the total length of the front shaft body 26. Therefore, the propeller shaft 22 gives no trouble, even if a drive unit 18 moves back in a collision so that it is possible to effectively produce the crushing in an engine room 20 so as to excellently absorb the collision energy.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) This invention relates to an automobile drive system that transmits power to a rear axle using a propeller shaft.

(Prior Art) Front-engine, rear-drive automobiles and front-engine four-wheel-drive vehicles are configured to transmit power from the engine and transmission gear at the front of the vehicle body to the II shaft via the propeller shaft. The propeller shaft is located in the center of the lower part of the vehicle body in the front-rear direction. Jitsukaisho 60-163120
As shown in the publication, many recent propeller shafts are of the three-joint type, with a total of three joints at both ends and in the center of the shaft.
Two universal joints are provided, and the orthogonal or immediate portion of the central universal joint is supported by the vehicle body via an intermediate bearing. The front universal joint is connected to the output shaft of the transmission or transfer, and the rear universal joint is connected to the rear axle differential.

(Problem to be solved by the invention) When a car is collided from the front, the engine compartment at the front of the car body deforms appropriately, thereby mitigating the impact force, which minimizes damage to the occupants. It is beneficial for

In order for the engine compartment to collapse effectively in the event of a collision, the drive unit (integral structure that includes the engine, transmission, transfer, etc.) within the engine compartment must be able to move rearward within the range that does not fly out into the instep during a collision. It is necessary to move to

This creates a considerable shock-reducing effect.

However, in conventional cars with a propeller shaft, the propeller shaft supports the drive unit from behind in the event of a collision.
There was a problem that the drive unit was difficult to move backwards. Additionally, when the drive unit retreats due to a severe collision, the propeller shaft bends at the universal joint, causing the propeller shaft to hit the fuel tank located above the propeller shaft at the rear of the vehicle.

This invention was made in view of the above-mentioned conventional problems, and its purpose is to provide an automobile drive system in which the propeller shaft does not shorten in the event of a collision and prevent the drive unit from moving backward. .

(Means for Solving the Problems) Therefore, in the automobile drive device according to the present invention, the central portion of the propeller shaft is supported by the vehicle body via an intermediate bearing, and the propeller shaft in the forward portion of the intermediate bearing is supported in the axial direction. A shaft reducing means for shortening the shaft length by receiving the force is provided.

(Function) When an axial impact force is applied to the propeller shaft from the drive unit side during a collision, the shaft reduction means functions to shorten the length of the shaft body in front of the intermediate bearing, and the drive unit Tolerate setbacks.

(Embodiment) FIGS. 1 and 2 show a schematic configuration of a four-wheel drive vehicle according to an embodiment of the present invention. 10 is a front axle that drives the front axle 12; 14 is a rear axle that drives the rear wheels 16; 18 is a drive unit installed in the engine room 20 at the front of the vehicle body; 22 is power from the drive unit 18 to the rear axle 14. This is the propeller shaft for transmitting the information.

The drive unit 18 includes an engine 18a and a transmission 11.
It is an integral structure including 8b. This transfer 18b
The parts include the clutch and transmission.

It includes an auxiliary transmission, a mechanism that divides power into a front wheel drive system and a rear wheel drive system, a differential device for the front axle 10, and the like.

The propeller shaft 22 is of a three-joint type, and a total of three universal joints 22a, 22b, and 22C are provided at both ends and at the center. The front universal joint 22a is the transfer 18
tl output shaft, and the rear universal joint connects to the rear axle 14.
The input shaft of the differential device 24 is coupled to the input shaft of the differential device 24 of The central universal joint 22b connects the front shaft body 26 and the rear shaft body 2 of the propeller shaft 22.
8 is combined. A rear end portion of the front shaft body 26 is supported by the vehicle body via an intermediate bearing 30.

In this embodiment, the front shaft body 26 of the propeller shaft 22 has the structure shown in FIG. 3, and the aforementioned shaft reduction means is provided here.

As shown in FIG. 3, the front shaft body 26 includes a shaft 26a and a hollow shaft 26b connected by a spline joint 26c.
It has become lli. With spline joint part 26C,
The shaft 26a and the hollow shaft 26b rotate together, but when a large force is applied in the axial direction, the shaft 26a and the hollow shaft 26b undergo relative sliding displacement in the axial direction.

Normally, the spline joint portion 26c is in the state shown in FIG. 3, and the front shaft body 26 is rotating with the entire length at its longest. When a strong force is applied to the front shaft body 26 from the front, the rear end of the shaft 26a deeply enters the hollow @26b, and the total length of the front shaft body 26 is shortened by L at the maximum. This distance L is approximately equal to the travel distance of the drive unit 18 until it comes into contact with the dash panel 32 due to a collision.

As is clear from the above description, this example is unique! 171
When a car collides from the front, the engine compartment is crushed by the impact and the internal drive unit 18 moves backwards, whereas the drive unit 18 moves backwards to a position where it abuts the dash panel 32. is not an obstacle at all, and the length of the front shaft body 26 is only shortened. Therefore, an accident in which the rear shaft body 28 of the propeller shaft 22 is bent at the universal joints 22b and 22c and comes into contact with the fuel tank 34 installed above these parts does not occur.

In addition, although the spline joint part 26c was provided as a shaft reduction means of the front shaft body 26 in the said Example, this invention is not limited to this. This shaft reduction means only needs to function with extremely large impact force at the time of collision, and does not need to have a function of smoothly changing the shaft length with small force. Therefore, for example, the shaft 26a and the hollow shaft 26b may be connected by a bottle, and the bottle may be broken by a large impact force, thereby shortening the shaft length.

Further, the present invention is particularly effective when applied to a horizontal engine type four-wheel drive vehicle as in the actual example, but it is of course not limited thereto. It can also be applied to normal front-engine, rear-drive cars that have a propeller shaft.
The same effect as above is achieved.

(Effects of the Invention) As explained in detail above, according to the automobile drive system according to the present invention, the propeller shaft does not become an obstacle for the drive unit to move backward in the event of a collision, so that the engine compartment is not crushed in the event of a collision. This is effective in absorbing collision energy and mitigating damage to occupants.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a schematic configuration of a drive device for an automobile according to an embodiment of the present invention, FIG. 2 is a side view of the same, and FIG. 3 is a sectional view showing the configuration of essential parts in the same embodiment. 10...Front axle 14...Superior axle 18...Drive unit 20...Engine room 22...Propeller shafts 22a, 22b, 22c・−・−・Universal joint 26...Front shaft body 26a...Shaft 26b
...Hollow shaft 26Q...Spline joint part 28...Rear shaft body 30...Hollow bearing 32...Dash panel 34...Fuel tank

Claims (1)

[Claims] (1) In a vehicle that has a propeller shaft that transmits power from the engine and transmission at the front of the vehicle body to the rear axle, the center portion of the propeller shaft is supported by the vehicle body via an intermediate bearing, and the propeller shaft is located at the front portion of the intermediate bearing. A drive device for an automobile, characterized in that the shaft is provided with a shaft reduction means for shortening the shaft length by receiving an axial force on the shaft.