JPH02200530A - Hydraulic drive vehicle - Google Patents

Abstract

PURPOSE:To perform correct control and improve the safety and quality of a vehicle by providing a controller outputting the control signal to a capacity variable section and a hydraulic control unit according to the operation state of an engine and hydraulically drive-controlling front and rear wheels. CONSTITUTION:The first hydraulic drive section 14 is provided at the input portion of a front differential gear section 8, and a capacity variable section 16 changing its capacity is provided. The second hydraulic drive section 22 is provided at a rear differential gear section 20, and a hydraulic control unit 26 is provided on the way of hydraulic pipes 24-1 and 24-2. The detected signals of a steering rudder angle sensor 34 and an accelerator sensor 36 are inputted to a controller 28, control signals are outputted to the capacity variable section 16 and the hydraulic control unit 26, correct control can be performed with respect to such as the change of the rotation difference between the front and rear differential gear sections 8 and 20 or the torque augmentation control of rear wheels 42 and 42, for example, traction control is easily performed, and the safety of a four-wheel drive vehicle 2 can be improved.

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a hydraulically driven vehicle, and in particular, it is equipped with - engines, and the driving force from the engine drives a hydraulic drive section. This invention relates to a hydraulically driven vehicle that drives both wheels.

[Prior Art] 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 combined with the front wheel drive shaft. A variety of so-called four-wheel drive vehicles have appeared in which power is transmitted to the rear wheel drive shaft to drive all four wheels.

These four-wheel drive vehicles include those that simply use hypoid gears or bevel gears to change the direction of drive power transmission at right angles, and those that use a central differential between the engine transmission and the front and rear differential gears. There is something.

Some of the four-wheel drive vehicles are disclosed in Japanese Patent Publication No. 49-25893. The differential system for a hydraulically driven vehicle disclosed in this publication uses the hydraulic pressure of a hydraulic bomb 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.

[Problems to be Solved by the Invention] By the way, in conventional hydraulically driven vehicles, as shown in FIG. The transfer unit 150 is mechanically connected to the rear differential gear section 120 via a propeller shaft 152 to drive the rear wheels 142.

In addition, there is one in which a Visco drive unit 160 is interposed between the propeller shafts 152 as desired.

However, the front and rear wheels 112.112.142.142
Since the front differential gear section 108 and the rear differential gear section 120 are mechanically connected to each other by the propeller shaft 152 to drive the wheels, for example, when turning, a difference in rotation occurs between the front and rear wheels, causing a braking phenomenon. The driveability of the vehicle is not smooth,
Hiiragi has the disadvantage that it may cause the engine to stop.

Furthermore, it is possible to eliminate the braking phenomenon during turning by using the visco drive unit, but this visco drive unit utilizes viscous torque generated by the difference in rotation between the front and rear wheels. Therefore, it does not have a power transmission function that actively introduces and transmits power.

[Purpose of the Invention] Therefore, in order to eliminate the above-mentioned disadvantages, an object of the present invention is to provide a first hydraulic drive section connected to the input section of the front differential gear section, and to change the capacity of the first hydraulic drive section. A variable capacity section is provided, a second hydraulic drive section that transmits driving force to the rear wheel drive shaft is provided, the first hydraulic drive section and the second hydraulic drive section are connected by hydraulic piping, and oil is provided in the middle of the hydraulic piping. A hydraulic control unit that functions as a tank is provided, and a control section that outputs control signals to the variable capacity section and the hydraulic control unit depending on the engine operating state to drive and control the front and rear wheels hydraulically controls the engine's operating state. To realize a hydraulically driven vehicle that can perform appropriate control according to the conditions, improve the safety of the vehicle, and eliminate the propeller shaft to achieve lighter weight, lower vibration, and lower noise, and improve the quality of the vehicle. It is in.

[Means for Solving the Problems] In order to achieve this object, the present invention provides a hydraulically driven vehicle in which driving force from an engine is transmitted to the front and rear wheel drive shafts to respectively drive both the front and rear wheels. A front differential gear section for transmitting driving force to the wheel drive shaft is provided, a first hydraulic drive section is provided in communication with an input section of the front differential gear section, and a capacity variable section is provided for changing the capacity of the first hydraulic drive section. Provided, after the above g
A second hydraulic drive section that transmits driving force to the wheel drive shaft is provided, the first hydraulic drive section and the second hydraulic drive section are connected by a hydraulic pipe, and a hydraulic pipe that functions as an oil tank is installed in the middle of the hydraulic pipe. The present invention is characterized in that a control unit is provided, and a control section outputs a control signal to the variable capacity section and the hydraulic control unit according to the operating state of the engine, and controls the drive of the front and rear wheels by hydraulic pressure.

[Function] With the above-described configuration, when a control signal is output to the variable capacity section and the hydraulic control unit according to the operating state of the engine, the control section hydraulically controls the front and rear wheels, thereby improving vehicle safety. In addition to improving vehicle performance, the propeller shaft has been eliminated to reduce weight, vibration, and noise, thereby improving the quality of the vehicle.

[Examples] Examples of the present invention will be described in detail below based on the drawings.

FIG. 1 shows an embodiment of the invention.

In Fig. 1, 2 is a four-wheel drive vehicle using hydraulic pressure, for example, with front wheel drive (FF) specifications, 4 is a horizontally mounted engine, and 6
is the transmission.

A front differential gear part 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 meshed with the front differential gear part 8, respectively, and the outer ends of the front wheel drive shafts 10.10 are meshed with the front differential gear part 8. front wheels 12.12 are respectively attached to the . Further, a first hydraulic drive section 14 consisting of a hydraulic pump or a hydraulic motor is provided in communication with the input portion of the front differential 7 renial gear section 8, and a capacity variable section 16 for changing the capacity of the first hydraulic drive section 14 is provided.

A rear differential gear part 20 is provided meshingly between the rear wheel drive shafts 18, 18 of the four-wheel drive vehicle 2, and a second hydraulic drive part 22 is connected to the rear differential gear part 20.

The first and second hydraulic drive units 14.22 are connected by hydraulic piping, for example, two hydraulic piping 24-1.24-2, and an oil tank is provided in the middle of the hydraulic piping 24-1.24-2. A hydraulic control unit 26 is provided which functions as a hydraulic control unit.

Further, a control section 28 outputs a control signal to the variable capacity section 16 and the hydraulic control unit 26 according to the operating state of the engine 4, and controls the drive of the front wheels 12.12 and the rear wheels 42.42, which will be described later, using hydraulic pressure. will be established.

Specifically, the first rotation speed sensor 3 is attached to the first hydraulic drive unit 14.
0, and a second rotation speed sensor 32 is provided in the second hydraulic drive section 22, and these first and second rotation speed sensors 30
．． 32, a steering angle sensor 34, an accelerator sensor 36, a brake sensor 38, and a vehicle speed sensor 40 are connected to the control section 28, respectively. Then, detection signals from various sensors are input to the control section 28, and control signals are outputted to the capacity variable section 16 and the hydraulic control unit 26. The second hydraulic drive section 14.22 is driven and controlled by hydraulic pressure.

Note that reference numerals 42 and 42 indicate rear wheels respectively attached to the outer ends of the rear wheel drive shafts 18 and 18.

Next, the effect will be explained.

A detection signal from the steering angle sensor 34 is input to the control section 28, which causes the variable capacity section 16 and the hydraulic control unit 2B to output a control signal, thereby controlling the front and rear differential gear sections 18, 20 according to the steering angle. The rotation difference between the two is changed appropriately.

Further, when the accelerator opening degree detected by the accelerator sensor 36 is large, a detection signal from the accelerator sensor 36 is inputted to the control section 28, and a control signal is outputted to the variable capacity section 16 and the hydraulic control unit 2B. The capacity is controlled to increase the torque of the rear wheels 42,42.

A detection signal from the steering angle sensor 34 is input to the control section 28, and the variable capacity section 16 and the hydraulic control unit 2
When the accelerator opening degree detected by the accelerator sensor 36 is large during steering to output a control signal to the control unit 28
The rotation of the rear wheels 42.42 is accelerated to perform accelerator steering, thereby controlling the movement of the front and rear wheels 12.12 and 42.42.

Further, when a detection signal from the brake sensor 38 is input to the control unit 28 when the brake is operated, the pressure caused by the difference in capacity between the front and rear parts is used as a circulation brake.

As a result, detection signals from the first and second rotational speed sensors 30, 32, steering angle sensor 34, accelerator sensor 36, brake sensor 38, and vehicle speed sensor 40 are input to the control unit 28, and the variable capacity unit 16 and the hydraulic control unit 26 to output control signals to perform various functions such as changing the rotational difference between the front and rear differential gears 18, 20, increasing the torque of the rear wheels 42, 42, controlling the circulation brake based on the difference in capacity between the front and rear wheels, etc. Appropriate and active control can be performed according to driving conditions, traction control can be easily performed, and the safety of the four-wheel drive vehicle 2 using hydraulic pressure can be improved.

In addition, by making the four-wheel drive vehicle 2 use hydraulic pressure, the propeller shaft and transfer gear unit can be eliminated, and the interior space of the four-wheel drive vehicle 2 can be increased. It is possible to reduce the weight of the four-wheel drive vehicle 2 and to reduce vibration or noise during driving of the four-wheel drive vehicle 2, and the quality of the four-wheel drive vehicle 2 can be improved compared to the conventional one.

[Effects of the Invention] As described in detail above, according to the present invention, the first hydraulic drive section is provided in communication with the input portion of the front differential gear section, and the capacity variable variable capacity that changes the capacity of the first hydraulic drive section is provided. A second hydraulic drive section is provided for transmitting driving force to the rear wheel drive shaft, and the first hydraulic drive section and the second hydraulic drive section are connected by hydraulic piping, and an oil tank is provided in the middle of the hydraulic piping. A hydraulic control unit that functions as Accordingly, the control unit outputs a control signal to the variable capacity unit and the hydraulic control unit, allowing for appropriate control according to the operating condition.
Traction control can be facilitated and safety of hydraulically driven vehicles using hydraulic pressure can be improved. In addition, by using a hydraulically driven vehicle, it is possible to eliminate the propeller shaft and the transfer gear unit, making it possible to reduce the weight of the vehicle and reduce vibration or noise when driving the vehicle. can improve the quality of

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of a four-wheel drive vehicle showing an embodiment of the present invention. FIG. 2 is a schematic plan view 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 a transmission, 8 is a front differential gear section, 10.10 is a front wheel drive shaft, 12.12 is a front wheel, and 14 is a first hydraulic drive part, 16 is a capacitance variable part, 1
8.18 is a rear wheel drive shaft, 20 is a rear differential gear section, 22 is a second hydraulic drive section, 24-1.24-2 is a hydraulic piping, 26 is a hydraulic control unit, 28 is a control section, 3
0 is the first rotation speed sensor, 32 (also the second rotation speed sensor, 3
4 is a steering angle sensor, 36 is an accelerator sensor,
38 is a brake sensor, 40 is a vehicle speed sensor, 42.42
is the rear wheel.

Claims (1)

[Claims] 1. In a hydraulically driven 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 front differential gear section that transmits the driving force to the front wheel drive shafts is provided, and the front differential A first hydraulic drive section is provided in communication with an input portion of the gear section, and a capacity variable section that changes the capacity of the first hydraulic drive section is provided, and a second hydraulic drive section that transmits driving force to the rear wheel drive shaft is provided. the first hydraulic drive unit and the second hydraulic drive unit are provided in communication with each other via a hydraulic pipe, and a hydraulic control unit that functions as an oil tank is provided in the middle of the hydraulic pipe;
A hydraulically driven vehicle, comprising: a control section that outputs a control signal to the variable capacity section and the hydraulic control unit according to the operating state of the engine, and controls the driving of front and rear wheels by hydraulic pressure.