JPH01249523A - Hydraulic drive vehicle - Google Patents

Abstract

PURPOSE:To eliminate a conventional propeller shaft by coupling a drive side pump unit to one of differential gear units through the intermediary of a clutch, and by coupling a driven side turbine unit to the other differential gear unit while connecting both unit together through a hydraulic pressure introduction pipe. CONSTITUTION:In an FF type four wheel drive vehicle 2, a front differential gear unit 8 is coupled to a transmission 6 for an engine 4, and is also coupled thereto with a drive side pump unit 16 through the intermediary of a clutch 14 for changing over the drive mode between a two wheel drive mode and a four wheel drive mode. Further, the drive side pump unit 16 is coupled to a driven side turbine unit 20 composed of a drive side pump section 22 and a driven side turbine section 24, through a hydraulic pressure introduction pipe 18. Further drive power from the driven side turbine unit 20 is transmitted to a pair of rear wheels 30 through a rear differential gear unit 26. With this arrangement, it is possible to eliminate a conventional propeller shaft, thereby it is possible to reduce vibration and noise and to enhance the transmission efficiency and the like.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a hydraulically driven vehicle, and in particular, it is equipped with - engines, and transmits the driving force of the engines to front and rear differentials, respectively, to drive four wheels. The present invention relates to a hydraulically driven vehicle.

[Conventional technology]

Recently, in order to improve driving performance and safety in all driving conditions such as driving on rough roads and uneven terrain, as well as driving on normal roads, the driving force of the internal combustion engine has been divided between the front wheel drive shaft and the rear wheel drive shaft. A variety of so-called four-wheel drive vehicles have appeared, which transmit power to all four wheels and drive all four wheels.

Some of these four-wheel drive vehicles simply use hypoid gears or hevel gears to change the direction of drive power transmission at right angles, and others have a central differential interposed between the engine transmission and the front and rear differentials. .

Some of the four-wheel drive vehicles are disclosed in Japanese Patent Publication No. 49-25693. The differential system for a hydraulically driven vehicle disclosed in this publication uses the oil pressure of a hydraulic pump to drive all four wheels.

Further, there is one disclosed in Japanese Patent Application Laid-Open No. 60-71334. The method disclosed in this publication for additionally hydraulically driving the wheels of a vehicle is to connect a torque converter and a variable displacement pump to the prime mover, rotate the main drive wheels by the torque converter, and drive the variable displacement pump. The driven wheels are driven by a pump.

Furthermore, there is one disclosed in Japanese Unexamined Patent Publication No. 61-249828. The four-wheel drive drive coupling device disclosed in this publication has a hydraulic pump type coupling mechanism on the front wheel side that connects the drive shafts of the front and rear wheels, and connects the drive shafts of the front and rear wheels through a propeller shaft.

[Problem that the invention seeks to solve]

By the way, in a conventional four-wheel drive vehicle, as shown in FIG.
A propeller shaft 118 is interposed between the front differential 108 and the rear differential 126, and the propeller shaft 118 drives the front differential 108 to the rear differential. The driving force is transmitted to the motive power 126 to drive the rear axle 130.

For this reason, when the vehicle rotates at high speed, large vibrations and noise are generated in the propeller shaft 118, and vibrations and noise are also generated in the rear differential 126, which is made up of a hypoid gear etc. connected to the propeller shaft 118, making it difficult to ride the vehicle. It has the disadvantage of being uncomfortable.

In addition, in vehicles that are always in four-wheel drive, a lot of fuel is used to maintain the desired rotation speed by rotating the propeller shaft when four-wheel drive is not required, resulting in poor fuel efficiency. , it has the disadvantage of being economically disadvantageous.

Furthermore, the differential device for a hydraulically driven vehicle disclosed in the above-mentioned Japanese Patent Publication No. 49-256'13 is configured to supply hydraulic pressure to each of the four front and rear hydraulic motors.
The hydraulic piping is long, which increases costs, and the hydraulic pressure is constantly acting on each of the four hydraulic motors, resulting in poor fuel efficiency and a reduction in the efficiency of converting engine output into driving force. be. Further, for example, at the time of starting and restarting, it takes a long time for hydraulic pressure to be applied to each of the four hydraulic motors, resulting in poor responsiveness.

Furthermore, in the method of additionally hydraulically driving the wheels of a vehicle disclosed in Japanese Patent Application Laid-Open No. 60-71334, a clutch is provided between the driven wheels, and hydraulic pressure is constantly applied to the vicinity of the driven wheels. This action requires long piping, which increases costs, and also causes disadvantages such as deterioration of fuel efficiency and reduction in efficiency of converting engine output into driving force.

Also, 4 disclosed in Japanese Patent Application Laid-Open No. 61-249828
In a wheel drive drive coupling device, the drive shafts of the front and rear wheels are connected through the propeller shaft, which generates large vibrations and noise at the propeller shaft when the vehicle rotates at high speed, and the hypoid gear connected to this propeller shaft. Vibration and noise are also generated in the rear differential, which is made up of the rear differential gear, etc., resulting in an inconvenience in that the riding comfort of the vehicle deteriorates.

[Purpose of the invention]

SUMMARY OF THE INVENTION Therefore, in order to eliminate the above-mentioned disadvantages, it is an object of the present invention to provide a differential for transmitting the driving force from the engine of a four-wheel drive vehicle to the other wheel drive shafts, and also to transmit the driving force from the engine of a four-wheel drive vehicle to the other wheel drive shafts. A differential is provided, a drive side pump unit is connected to the - differential via a clutch, a driven side turbine unit is provided to the other differential, and the drive side pump unit and driven side turbine unit are connected. By connecting them through a hydraulic pressure introduction pipe, it is possible to reduce the generation of vibration and noise when driving force is transmitted through the hydraulic pressure introduction pipe, and the clutch on the front wheel side allows the hydraulic pressure to be applied efficiently, reducing fuel consumption and output. The objective is to realize an improved hydraulically driven vehicle.

[Means for solving problems]

In order to achieve this object, the present invention provides a four-wheel drive vehicle in which driving force from an engine is transmitted to front and rear wheel drive shafts to drive both front and rear wheels, respectively. A differential for transmitting power to the drive shaft is provided, and another differential for transmitting power to the other wheel drive shaft is provided, a drive-side pump unit is connected to the negative differential via a clutch, and The differential is provided with a driven side turbine unit, and the driving side pump unit and the driven side turbine unit are connected through a hydraulic pressure introduction pipe.

[Effect]

With the above-described configuration, when the engine of a four-wheel drive vehicle is driven, the driving force from the front wheels can be transmitted to the rear wheels through the hydraulic pressure introduction pipe, thereby reducing the generation of vibration and noise when the driving force is transmitted. At the same time, by switching the clutch on the front wheel side, hydraulic pressure is efficiently applied to the rear wheel side, improving fuel efficiency and output.

〔Example〕

Embodiments of the present invention will be described in detail below based on the drawings.

Figure 1.2 shows an embodiment of the invention. 1st
In the figure, 2 is, for example, a four-wheel drive vehicle using hydraulic pressure with front wheel drive (FF) specifications, 4 is a horizontal engine, and 6 is an automatic transmission. A front differential 8 is provided which communicates with the transmission 6 of the engine 4, and the inner ends of the front wheel drive shafts 10, 10 are engaged with the front differential 8, respectively, and the outer ends of the front wheel drive shafts 10, 10 are engaged with the front differential 8, respectively. are fitted with front wheels 12 and 12, respectively. Also, a metering hydraulic pump 16, which is a drive side pump unit, is connected to the front differential 8 via a clutch I4 that switches between four-wheel drive and two-wheel drive.
Communicate and set up.

Further, a hydraulic pump 16 is provided in communication with a driven side turbine unit 20 through a hydraulic pressure introduction pipe 8, and this driven side turbine unit 20 is connected to a rear wheel 30 which will be described later.
．． Provided on the 30 side.

The driven-side turbine unit 20 includes a driving-side pump section 22 and a driven-side turbine section 24, and is configured to convert oil pressure into driving force.
A rear differential 26 is provided to transmit driving force from 0 to rear wheels 30, 30, which will be described later. The rear differential 26 is engaged with the inner ends of rear wheel drive shafts 28, 28, respectively, and the rear wheels 30, 30 are mounted on the outer ends of the rear wheel drive shafts 28, 28, respectively.

Further, a control section 32 is provided that controls switching of the clutch I4 and the flow rate of the driven turbine unit 20 depending on a predetermined operating state.

More specifically, as shown in FIG. 2, for example, a vehicle speed sensor 34 detects vehicle speed, a wheel slip sensor 36 detects wheel slip, a G sensor 38 detects gravity G in the horizontal direction, and a steering angle detects. A steering sensor 40 is connected to the control unit 32, and these vehicle speed sensor 34 and wheel slip sensor 3G
, the G sensor 38, and the steering sensor 40 to detect the operating state and control the switching of the clutch 14 and the flow rate of the driven turbine unit 20.

In addition, it is better to provide assistance from the rear wheels 30 side during sudden acceleration or on snowy roads, and torque distribution that emphasizes the front wheels 10 side may be sufficient. In other words, in this embodiment, as is clear from FIG. 1, the load on the 10 mechanically driven front wheels, which are more efficient due to the layout, is greater than that on the hydraulically driven rear wheels 30, which are somewhat less efficient. By variably increasing the transmission torque on the rear wheel 30 side, the torque distribution ratio of the vehicle is increased to 100:
Can be changed from 0 to 50:50, rear wheel 30
Assistance from the side is effectively provided.

Next, the effect will be explained.

In a driving state in which the vehicle speed signal from the vehicle speed sensor 34 is steady, there is no wheel slip signal from the wheel slip sensor 36, there is no horizontal gravity G from the G sensor 38, and the steering angle is small from the steering sensor 40. The detection signals of the sensors 34, 36, 38, and 40 are input to the control section 32, and the control section 32 controls the clutch 14 to turn off, thereby setting the vehicle in a two-wheel drive state. At this time, the front and rear torque ratio of the four-wheel drive vehicle 2 is set to 100:0.

Further, during rapid acceleration/deceleration, cornering, or wheel slip, the control section 32 turns on the clutch 14 to set the four-wheel drive state to the four-wheel drive vehicle 2.
The torque ratio before and after is set to 50:50.

During slow acceleration/deceleration or cornering, the control unit 32 turns on the clutch 14, variably controls the flow rate of the driven turbine unit 20, and changes the front and rear torque ratio of the four-wheel drive vehicle 2 to set the four-wheel drive state. 15:2
5.

Furthermore, when driving at low speed and with a large steering angle, such as when parking in a garage, the control section 32 controls the clutch 14.
is turned ON, the flow rate of the driven turbine unit 20 is variably controlled, and the front and rear torque ratio of the four-wheel drive vehicle 2 is set to 90:10 to set the four-wheel drive state. At this time, if slipping occurs due to snowy roads or the like, the torque ratio on the rear side of the four-wheel drive vehicle 2 can be increased.

As a result, the front and rear differentials 8.26 on the front and rear wheels 12.12 and 30130 side are operated as in the prior art.

It is possible to use the hydraulic pressure introduction pipe 18 which is not connected by the Lobera shaft and does not rotate, and it is possible to reduce the vibration and noise caused by the transmission of driving force when the vehicle rotates at high speed, and to improve the riding comfort of the vehicle. .

In addition, the clutch 14 on the front wheel 12.12 side switches the hydraulic pressure to the rear wheel 30.30 side, so that the hydraulic pressure can be efficiently applied to the rear wheel 30.30 side, improving fuel efficiency and output. Therefore, it is economically advantageous.

Furthermore, by controlling the flow rate of the driven turbine unit 20 by the control section 32, the torque ratio between the front and rear of the vehicle can be variably distributed, and the usability of the vehicle can be improved.

Furthermore, by not using a propeller shaft, there is no projecting part of the propeller shaft in the space inside the vehicle, and the space under the feet becomes wider, which is advantageous in practice.

In addition, by using a small-diameter hydraulic pressure introduction pipe instead of a large-diameter propeller shaft, there is greater freedom in the layout of the hydraulic pressure introduction pipe on the bottom of the vehicle, making it easier to arrange the hydraulic pressure introduction pipe. It's something you get.

Note that the present invention is not limited to the above-described embodiments, and various modifications can be made.

For example, in the embodiment of the present invention, as shown in FIG. The side turbine unit 50 is
As shown in the figure, two driven side left and right turbine parts 52-1
．． 52-2 and these driven side left and right turbine parts 52-1.
Consisting of a drive side pump section 54 provided between 52-2,
Alternatively, other configurations are also possible.

Furthermore, in the embodiment of the present invention, the control unit switches the clutch and controls the flow rate of the driven turbine unit according to a predetermined operating state, but the flow rate of the driven turbine unit is kept constant. At the same time, the hydraulic pump, which is the drive side pump unit, is of variable displacement type.
This variable displacement hydraulic pump can also be controlled by a control section according to a predetermined operating state.

〔Effect of the invention〕

As explained in detail above, according to the present invention, one differential is provided for transmitting the driving force from the engine of the four-wheel drive vehicle to the other wheel drive shaft, and another differential is provided for transmitting the driving force from the engine of the four-wheel drive vehicle to the other wheel drive shaft. A drive-side pump unit is connected to the - differential via a clutch, a driven-side turbine unit is provided to the other differential, and the drive-side pump unit and driven-side turbine unit are hydraulically introduced. Since the front and rear differentials on the front and rear wheels are connected by a pipe, the front and rear differentials on the front and rear wheels are not connected by the propeller shaft as in conventional technology, but by using a non-rotating hydraulic pressure introduction pipe to transmit driving force when the vehicle rotates at high speed. The generated vibration and noise can be reduced, and the ride comfort of the vehicle can be improved. In addition, the hydraulic pressure can be switched to the rear wheels using the clutch on the front wheels, so that the hydraulic pressure can be efficiently applied to the rear wheels, improving fuel efficiency and output, which is economically advantageous. Furthermore, by controlling the flow rate of the driven turbine unit by the control section, the torque ratio between the front and rear of the vehicle can be variably distributed, and the usability of the vehicle can be improved. Furthermore, by not using a propeller shaft with a large diameter, the foot space inside the vehicle becomes larger, which is a practical advantage, and the layout of the hydraulic pressure introduction pipe on the bottom of the vehicle becomes more flexible, allowing for better hydraulic introduction. The pipe arrangement work can be easily performed.

[Brief explanation of the drawing]

1.2 shows an embodiment of the present invention, FIG. 1 is a schematic plan view of a four-wheel drive vehicle, and FIG. 2 is a schematic control diagram of the four-wheel drive vehicle. FIG. 3 is an enlarged sectional view of a main part of a driven turbine unit of a four-wheel drive vehicle showing another embodiment of the present invention. FIG. 4 is a schematic layout diagram of a four-wheel drive vehicle showing the prior art of the present invention. In the figure, 2 is a four-wheel drive vehicle, 4 is a transverse engine, 6 is an automatic transmission, 8 is a front differential, 10.10 is a front wheel drive shaft, 12 is a front wheel, 1
4 is a clutch, 16 is a hydraulic pump, 18 is a hydraulic introduction pipe,
20 is a driven side turbine unit 7, 22 is a driving side pump section, 24 is a driven side turbine section, 26 is a rear differential,
28.28 is the rear wheel drive shaft, 30.30 is the rear wheel, 32
34 is a vehicle speed sensor, 36 is a wheel slip sensor, 38 is a G sensor, and 40 is a steering sensor. Patent Applicant Lead Automobile Industry Co., Ltd. Agent Patent Attorney Yoshi Saigo Younger brother 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. In a four-wheel drive vehicle that transmits the driving force from the engine to the front and rear wheel drive shafts to respectively drive both the front and rear wheels, a differential that transmits the driving force from the engine to the first wheel drive shaft. and another differential for transmitting power to the other wheel drive shaft, a drive side pump unit is connected to the first differential via a clutch, and a driven side turbine is connected to the other differential. 1. A hydraulically driven vehicle, characterized in that a unit is provided, and the driving side pump unit and the driven side turbine unit are connected through a hydraulic pressure introduction pipe.