JPH1170876A - Brake driving device for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To not only work for the effective utilization of energy but also work for saving natural resources, and for restraining environment from being degraded, and concurrently materialize the enhancement of operating performance at the time of braking and acceleration. SOLUTION: This brake driving device for an automobile is equipped with a hydraulic rotation device 21 to be rotated together with a wheel 5a, allows the rotation device to act as a hydraulic pump by means of an axle 5a at the time of braking to store generated hydraulic pressure in an accumulator 25, and also allows the hydraulic rotation device 21 to act as a hydraulic motor at the time of acceleration by means of hydraulic pressure discharged out of the accumulator 25, so that the axle 5a is thereby endowed with driving force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake driving device for the purpose of effectively utilizing energy in a vehicle and improving operability during braking and acceleration, and belongs to the field of vehicle braking driving technology.

[0002]

2. Description of the Related Art In recent years, with respect to automobiles, it has been required to reduce fuel consumption as a so-called resource saving measure and to reduce exhaust gas emission as an environmental measure as well as to improve safety. Various measures such as improvement of the combustion state of the engine are being taken.

[0003]

However, the above-mentioned measures on the engine side alone are not always enough to save resources and the like, and more drastic measures are desired.

[0004] Therefore, the present invention reduces the fuel consumption and the exhaust gas emission more effectively by making effective use of the energy released from the vehicle, and at the same time improves the operability during braking and acceleration. The task is to achieve

[0005]

Means for Solving the Problems In order to solve the above problems, the present invention is characterized in that it is configured as follows.

That is, according to the invention described in claim 1 of the present application, a hydraulic pressure generating means which is driven by the rotation of wheels to generate a hydraulic pressure, and a pressure accumulating means which accumulates the hydraulic pressure generated by the hydraulic pressure generating means Means, a hydraulic drive means driven by hydraulic pressure released from the pressure accumulating means to apply a driving force to wheels, and a hydraulic pressure generating means operated during braking to accumulate the generated hydraulic pressure in the pressure accumulating means and accelerate Control means for releasing the hydraulic pressure accumulated in the pressure accumulating means at times to operate the hydraulic driving means.

Further, according to a second aspect of the present invention, in the first aspect of the present invention, the hydraulic pressure generating means and the hydraulic drive means are constituted by a single hydraulic rotating device.

According to the present invention, the following effects can be obtained according to the present invention.

First, at the time of braking, the kinetic energy of the wheels, which has conventionally been converted into heat by friction in the brake device and released to the outside air, is converted into hydraulic pressure by the operation of the hydraulic pressure generating means and stored in the pressure accumulating means. Thus, wasteful release of energy during braking is suppressed.

During the next acceleration, the hydraulic drive means operates by the hydraulic pressure stored in the pressure accumulating means to apply a driving force to the wheels, thereby suppressing an increase in the engine output required for acceleration. As a result, the fuel consumption of the engine is reduced, and the exhaust gas emission is accordingly reduced.

Further, during braking, the reaction force generated when the hydraulic pressure generating means is driven by the rotation of the wheel acts as a resistance to the rotation of the wheel, so that the stepping force on the brake pedal by the driver is reduced accordingly. Also, during acceleration, the amount of depression of the accelerator pedal by the driver is reduced by the amount of driving force applied to the wheels by the hydraulic drive means, and the operability of the depression operation of these pedals is improved. Become.

According to the second aspect of the present invention, since the hydraulic pressure generation means and the hydraulic drive means are constituted by a single hydraulic rotation device, the structure of the system is simplified. .

[0013]

Embodiments of the present invention will be described below.

As shown in FIG. 1, an automobile 1 according to this embodiment is configured to drive left and right front wheels 4, 4 via a transmission 3 by the output of an engine 2, and 4 and the rear wheels 5, 5 are provided with brake devices 6,..., 6 for braking the rotation of the wheels, and an accelerator pedal 7 for controlling the output of the engine 2 by the operation of the driver. A brake pedal 8 for operating the brake devices 6... 6 by a driver's operation is provided.

Further, the vehicle 1 is provided with a braking drive system 10 for effective use of energy in addition to the above configuration. The system 10 includes hydraulic units 11, 11 provided on axles 5a, 5a of left and right rear wheels 5, 5, respectively, and hydraulic units 11, 11,
And a control unit 12 for controlling the operation of the accelerator pedal 13. The control unit 12 detects an accelerator switch 13 for detecting the depression operation of the accelerator pedal 7 by the driver, and also detects the depression operation of the brake pedal 8 by the driver. The signal from the brake switch 14 is input.

Next, the structure of the hydraulic units 11, 11 will be described. As shown in FIG. 2, they have the same structure, and all of them have a hydraulic rotating device 21 provided on the axle 5a of the wheel 5. The first and second switching valves 2 provided on the hydraulic oil inlet 21a side and the outlet 21b side of the device 21, respectively.
2, 23, a reservoir tank 24 disposed upstream of the first switching valve 22, and an accumulator 25 disposed downstream of the second switching valve 23.

The hydraulic oil suction passage 26 led from the reservoir tank 24 and the hydraulic discharge passage 27 led from the accumulator 25 are connected to the first switching valve 22 and operate to reach the reservoir tank 24. An oil recovery passage 28 and a hydraulic supply passage 29 leading to the accumulator 25
Are guided from the second switching valve 23. In addition, a relief valve 30 that opens at the pressure limit of the accumulator 25 is installed in the hydraulic pressure supply passage 29.

On the other hand, the hydraulic rotating device 21 is provided with an axle 5a.
When driven by the rotation of the cylinder, it operates as a hydraulic pump, generates hydraulic pressure by sucking hydraulic oil from the inlet 21a, outputs this hydraulic pressure to the outlet 21b side, and when hydraulic pressure is supplied from the inlet 21a side, Works as a motor,
After the axle 5a is driven by the hydraulic pressure, the hydraulic oil is discharged to the outlet 21b side.

When hydraulic pressure is introduced into the cylinder 25a, the accumulator 25
The spring 25c is contracted through the
When the external pressure becomes lower than the pressure in 5a, the spring 25c expands and releases the hydraulic pressure to the outside via the piston 25c.

Further, the first switching valve 22 connects the hydraulic oil suction passage 26 led from the reservoir tank 24 to the inlet 21 a of the hydraulic rotating device 21, and the hydraulic discharge passage led from the accumulator 25. 27 for shutting off the hydraulic oil suction passage 26
And the hydraulic discharge passage 27 is connected to the hydraulic rotating device 2.
And a second position 22a which communicates with the first inlet 21a, and these positions 22a and 22b are switched by a signal from the control unit 12 shown in FIG.

The second switching valve 23 connects the outlet 21 b of the hydraulic rotating device 21 to a hydraulic oil recovery passage 28 leading to the reservoir tank 24 and shuts off a hydraulic supply passage 29 leading to the accumulator 25. It has a first position 23a and a second position 23a that shuts off the hydraulic oil recovery passage 28 leading to the reservoir tank 24 and communicates the outlet 21b of the hydraulic rotation device 21 with a hydraulic supply passage 29 leading to the accumulator 25. Figure 1
The positions 23a and 23b are switched by a signal from the control unit 12 shown in FIG.

Next, the operation of the system 10 will be described.

First, during normal running of the vehicle 1, each hydraulic unit 1 is controlled by a signal from the control unit 12.
In FIG. 1, as shown in FIG.
2 and 23 are both in the first positions 22a and 23a, and the hydraulic oil rotary device 21 has an inlet 21a side to a hydraulic oil suction passage 26 led from a reservoir tank 24, and an outlet 21b side to the hydraulic oil intake passage 26 also reaching the reservoir tank 24. Collection passage 28
Are in communication with each other. Therefore, in this state, the hydraulic rotation device 21 does not operate as a hydraulic pump or a hydraulic motor, and is in a state of idling with the rotation of the axle 5a.

In this state, assuming that the driver stops the vehicle 1 or depresses the brake pedal 7 in order to reduce the traveling speed, the driver receives a signal from the brake switch 13 for detecting this operation. , Control unit 1
2 outputs a signal to each of the hydraulic units 11, 11 to perform an operation at the time of braking.

That is, when this signal is received, in the hydraulic unit 11, as shown in FIG. 3, the second switching valve 23 is moved from the first position 23a to the second position 23b.
To make the outlet 21b side of the hydraulic rotating device 21 communicate with the hydraulic supply passage 29 leading to the accumulator 25.

Thus, the hydraulic rotating device 21 operates as a hydraulic pump driven by the rotation of the axle 5a,
Hydraulic oil in the reservoir tank 24 is sucked from the inlet 21a through the hydraulic oil suction passage 26 and the first switching valve 22, and the operating oil is pressurized and output from the outlet 21b as a hydraulic pressure having a constant pressure. This hydraulic pressure is introduced into the cylinder 25a of the accumulator 25 via the hydraulic pressure supply passage 29, and contracts the spring 25c via the piston 25b.

In this case, the hydraulic pressure is introduced even after the spring 25c is sufficiently contracted, and the accumulator 25
When there is a possibility that the internal pressure may increase excessively, the relief valve 30 provided in the hydraulic pressure supply passage 29 is opened, so that an excessive increase in the pressure in the accumulator 25 is avoided.

Then, as described above, the hydraulic rotating device 21
Generates hydraulic pressure by pressurizing the working oil and introduces it into the accumulator 25, the reaction force acts on the hydraulic rotating device 21 and this acts as a resistance to the rotation of the axle 5a, thereby causing the axle 5a to rotate. Work to lower the rotation of
As a result, the stepping force of the brake pedal 7 by the driver can be reduced.

Further, when the operation of depressing the brake pedal 7 by the driver is completed and a signal indicating the operation is inputted from the brake switch 13 to the control unit 12, the control unit 12 Second switching valve 23
Is operated again to the first position 23a side. At this time, the hydraulic pressure supply passage 29 and the hydraulic pressure release passage 27 leading to the accumulator 25 are located at the first position 23a of the second switching valve 23 and the first position 22a of the first switching valve 22, respectively.
Both are in a shut-off state, so that the hydraulic pressure introduced into the accumulator 25 is confined in the accumulator 25.

Thus, the brake devices 6, 6 can be used during braking.
Wheels that are converted into frictional heat and released into the outside air at
At least a part of the kinetic energy of No. 5 is collected, converted into hydraulic pressure, and stored in the accumulator 25.

Next, when the driver depresses the accelerator pedal 8 to accelerate the vehicle, the control unit 1 receives a signal from the accelerator switch 14 for detecting this operation.
2 outputs a signal to each of the hydraulic units 11 and 11 to perform an operation at the time of acceleration.

That is, when this signal is received, the first switching valve 22 is set in the hydraulic unit 11 as shown in FIG.
Is switched from the first position 22a to the second position 22b, and the hydraulic discharge passage 27 guided from the accumulator 25 communicates with the inlet 21a of the hydraulic rotating device 21.

At this time, the hydraulic pressure stored in the cylinder 25a of the accumulator 25 is changed by the spring 25
When c is extended, it is discharged to the outside via the piston 25b and supplied to the inlet 21a side of the hydraulic rotating device 21 via the hydraulic discharge passage 27 and the first switching valve 22.
Thus, the hydraulic rotating device 21 operates as a hydraulic motor driven by the hydraulic pressure, and drives the axle 5a.
The hydraulic oil driving this axle 5a is supplied to the second switching valve 2
3 and is collected in the reservoir tank 24 through the hydraulic oil collection passage 28.

In this way, the energy recovered during braking and stored as hydraulic pressure in the accumulator 25 is used as energy for driving the axle 5a during the next acceleration. Therefore, at the time of acceleration, the increase in the output of the engine 2 can be reduced by the amount of the energy, and as a result, the fuel consumption is reduced and the exhaust gas emission is reduced accordingly. . Also,
As the increase in the output of the engine 2 is suppressed, the amount of depression of the accelerator pedal 8 by the driver during acceleration can be reduced.

In the above embodiment, the hydraulic units 11, 11 are provided on the rear wheels 5, 5, which are driven wheels. However, the hydraulic units 11, 11 are provided on the front wheels 4, 4 which are driving wheels. ,
It is also possible to provide at 5,5. The same applies to a vehicle having front wheels as driven wheels and a rear wheel as driving wheels, and all four wheels having driving wheels.

In the above embodiment, the single hydraulic rotating device 21 is used as a hydraulic pump and a hydraulic motor. However, a dedicated hydraulic pump and a hydraulic motor may be used.

When the brake pedal 7 and the accelerator pedal 8 are depressed, the hydraulic rotator 21 is always operated as a hydraulic pump or a hydraulic motor.
For example, the hydraulic rotating device 21 may be operated only at the time of a stop requiring a large braking force and at the time of a start requiring a large acceleration force. In this case, for example, the automobile 1
A sensor that detects the vehicle speed of the vehicle is provided, and it is determined whether the operation is a brake operation for stopping the vehicle or an accelerator operation for starting the vehicle.

Further, in the above-described embodiment, even in the state shown in FIGS. 2 and 4, that is, in the state where neither the hydraulic pump nor the hydraulic motor is operating, the hydraulic rotating device 2
1 rotates with the axle 5a to circulate the hydraulic oil in the reservoir tank 24. A clutch is interposed between the axle 5a and the hydraulic rotator 21, and the hydraulic rotator 21 is connected to the hydraulic pump. Alternatively, when not used as a hydraulic motor, the clutch is disconnected and the hydraulic rotating device 2 is disengaged.
By stopping 1, it is also possible to further reduce the energy loss.

[0039]

As described above, according to the present invention, at the time of braking, the kinetic energy of the wheels, which has conventionally been converted to heat by friction in the brake device and released to the outside air, is converted to hydraulic pressure and stored. As a result, wasteful release of energy is suppressed, and this energy is converted into driving force at the next acceleration and used for driving the wheels. As a result, effective use of energy is achieved, and increase in engine output during acceleration is reduced, so that fuel consumption of the engine is reduced. The amount is also suppressed. As a result, problems relating to resource saving and environmental degradation of automobiles are solved.

Also, at the time of braking, the reaction force at the time of converting the kinetic energy of the wheel into hydraulic pressure acts to reduce the rotation of the wheel, and at the time of acceleration, the recovered energy applies the driving force to the wheel. Therefore, the amount of depression of the brake pedal and the accelerator pedal by the driver is reduced, and the operability at the time of depressing these pedals is improved.

[Brief description of the drawings]

FIG. 1 is a control system diagram showing an embodiment of the present invention.

FIG. 2 is a hydraulic circuit diagram showing a non-operating state of a hydraulic unit in the system.

FIG. 3 is a hydraulic circuit diagram showing a state during braking.

FIG. 4 is a hydraulic circuit diagram showing a pressure accumulation state.

FIG. 5 is a hydraulic circuit diagram showing a state at the time of acceleration.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Automobile 5 Wheel 12 Control means (control unit) 21 Hydraulic pressure generating means, hydraulic drive means (hydraulic rotation device) 25 Accumulator (accumulator)

Claims (2)

[Claims] 1. A hydraulic pressure generating means for generating a hydraulic pressure by being driven by rotation of a wheel, a pressure storing means for accumulating a hydraulic pressure generated by the hydraulic pressure generating means, and a wheel driven by a hydraulic pressure released from the pressure storing means. Hydraulic drive means for applying a driving force to the hydraulic pressure generating means during braking to cause the generated hydraulic pressure to accumulate in the pressure accumulating means, and to release the hydraulic pressure accumulated in the pressure accumulating means during acceleration, And a control means for operating the hydraulic drive means. 2. The vehicle brake driving device according to claim 1, wherein the hydraulic pressure generating means and the hydraulic driving means are constituted by a single hydraulic rotating device.