JPH0692209A - Regenerative braking device of vehicle - Google Patents

Abstract

PURPOSE:To improve the responsiveness in the initial operating range and to keep reliability even during pause by providing a second brake valve output even in the inoperative range of a first brake valve, and outputting a higher pressure of a relay valve or the first brake valve output from the second brake valve by a selector valve. CONSTITUTION:In an inoperative range of a brake valve 2, a signal pressure of a brake pedal 1 is applied from an auxiliary brake valve 3 through a signal pressure passage 11 to a relay valve 8, and air pressure is supplied to double check valves 4, 5 and output to brake circuits 20, 21 to perform braking. When it exceeds the inoperative range, air pressure is supplied from the brake valve 2 to a primary circuit 18 and a secondary circuit 19, and air pressure from the relay valve 8 is applied to a service brake. When the brake pedal 1 is further actuated, the air pressure from the brake valve 2 exceeds the air pressure from the relay valve 8, so that the double check valves 4, 5 are switched and the air pressure is supplied to the brake circuits 20, 21 to decrease the speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative braking system for a vehicle, which collects kinetic energy when the vehicle decelerates, accumulates the pressure, and uses it as driving energy.

[0002]

2. Description of the Related Art Conventionally, regenerative braking devices of this type have been disclosed in, for example, Japanese Patent Application Laid-Open Nos. 2-124349 and 6-26.
The thing disclosed by the 1-175153 gazette is known.

In these devices, a pump motor is connected to a wheel drive system via an electromagnetic clutch, one port of the pump motor is connected to an accumulator on the high pressure side, and the other port is connected to a tank on the low pressure side. ing.
During deceleration of the vehicle, the pump motor is connected to the wheel drive system to operate as a pump to brake the wheel drive system using the pump motor as a load and accumulate high pressure oil in the accumulator to recover the kinetic energy of the vehicle. Is configured. The energy stored in the accumulator is used as drive energy for the wheel drive system by connecting the pump motor to the wheel drive system to act as a motor when the vehicle starts, for example.

Further, in the former device, the proportional control valve is electronically controlled so that the depression amount of the brake pedal and the brake torque generated on the wheels correspond to each other in accordance with the pressure accumulation state of the regenerative device. On the other hand, in the latter device, the initial depression amount of the brake pedal is set large,
The service brake (foot brake) is not operated, and the regenerative device is operated during the stepping margin to recover the kinetic energy.

[0005]

However, in the former device, since the service brake is driven only by the electronic control means, there is a problem that the reliability of the control means is low with respect to the failure. The latter device has a problem that when the regenerative device does not operate, the depression amount of the brake pedal becomes a mere play, and the responsiveness of the service brake is impaired.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a regenerative braking system for a vehicle, which improves the response of the service brake when the regenerative braking is inoperative and ensures reliability.

[0007]

DISCLOSURE OF THE INVENTION The present invention relates to a brake device provided with a regenerative device for transmitting a rotational force of a wheel to a pressurizing device to store a pressure for energy regeneration in an accumulator during braking when a brake pedal is operated. , A first brake valve having an inoperative region where no braking pressure is generated in the initial operating region of the brake pedal, and a brake pressure source linked to the operation of the brake pedal in the inoperative region of the first brake valve. Of the second brake valve that outputs the pressure from the second brake valve, the relay valve that outputs the pressure from the brake pressure source using the output of the second brake valve as a signal pressure, and the output of the relay valve or the first brake valve. A switching valve that selectively outputs the higher pressure to the service brake, a valve that opens and closes a signal pressure passage to the relay valve, and the regenerative device It detects during operation and control means for closing the valve of the signal pressure passage to.

[0008]

Therefore, in the case where the regenerative device does not operate, the first
In the non-operation area of the brake valve, the control means opens the valve of the signal pressure passage to apply the signal pressure corresponding to the pressure from the second brake valve to the relay valve. Since the switching valve has no braking pressure from the first brake valve, pressure is selected according to the signal pressure output by the relay valve and is output to the service brake for braking. On the other hand, in the inoperative region of the first brake valve during the operation of the regenerative device, the control means closes the valve of the signal pressure passage so that the output from the relay valve does not occur, and the switching valve includes the relay valve and the first valve. Braking is performed only by the braking force of the regenerative device without applying pressure from the first or second brake valve.

When the brake pedal is further depressed beyond the inoperative range of the first brake valve, the first brake valve operates, and when the output of the first brake valve becomes higher than the output of the relay valve, the switching valve operates. The output of the first brake valve is selected and output to the service brake.

[0010]

1 and 2 show an embodiment of the present invention.

In FIG. 1, reference numeral 2 denotes a brake valve as a first brake valve constituting a full air brake, which controls the air from the air reservoirs 14 and 15 according to the depression amount such as the depression angle of the brake pedal 1. Braking pressure is supplied to the primary circuit 18 and the secondary circuit 19. The brake valve 2 is connected to the primary circuit 1 until the depression angle of the brake pedal 1 reaches a predetermined value.
8 and the secondary circuit 19 are provided with a non-operation area where braking pressure is not output.

Numeral 3 is an auxiliary brake valve as a second brake valve which is interlocked with the brake pedal 1, and supplies the signal pressure from the air reservoir 14 to the signal pressure passage 11 in accordance with the depression angle of the brake pedal 1. The signal pressure passage 11 is connected to the signal pressure side of the relay valve 8 via a normally open solenoid valve 7 driven by the controller 10, and the pressure sensor 6 connected to the controller 10 is provided upstream of the solenoid valve 7. The controller 10 is provided and drives the regenerative device 30 based on the detection value of the pressure sensor 6.

On the other hand, the primary circuit 18 and the secondary circuit 19 connected to the brake valve 2 are connected to the input ports (not shown) of the double check valves 4 and 5 as switching valves for selecting and outputting the high pressure side. Each of the double check valves 4 and 5 has two input ports, and the downstream side of the relay valve 8 is connected to the other input port.

The relay valve 8 receives the supply of air from the air reservoir 14, and via the electromagnetic valve 7 driven by the controller 10, the double check valve 4 according to the pressure in the signal pressure passage 11 controlled by the auxiliary brake valve 3. Supply air to 5.

The output ports of the double check valves 4 and 5 are connected to the brake circuit 20 and the brake circuit 21, respectively. The air of the brake circuit 20 drives the brake chamber 24 via the relay valve 22, and the air of the brake circuit 21 is The brake chamber 25 is driven via the quick release valve 23. These brake chambers 24 and 2
Reference numeral 5 constitutes a service brake which is connected to a brake drum (not shown) to apply braking to the wheels.

As shown in FIG. 2, the regenerative device 30 has an output shaft of a transmission 41 connected to wheels 40, and an oblique shaft type (or swash plate type) pump motor via an electromagnetic clutch 42 driven by the controller 10. 43 connects. The solenoid valve 3 is provided on one port of the pump motor 43.
6 and the high pressure oil passage 44 including the accumulator 37 are connected, and the low pressure oil passage 45 including the tank 38 is connected to the other port. A pressure sensor 33 that detects the amount of regenerated energy as a pressure accumulation level is provided downstream of the accumulator 37. Instead of the pressure sensor 33, a potentiometer 33a that detects the position of the piston 37a of the accumulator 37 may be provided.

The controller 10 includes a vehicle speed signal V from a vehicle speed sensor 32, a shift position signal from a shift lever 34, a level signal L from a pressure sensor 33 for detecting a pressure accumulation level of an accumulator 37, and a signal pressure passage shown in FIG. The signal pressure P from the pressure sensor 6 which detects the pressure of 11 is input. The controller 10 calculates the braking torque required by the driver based on these input signals to set the flow rate of the pump motor 43, and sets the oblique axis drive device 35 so that the tilt angle of the oblique axis matches the set value. While driving, the solenoid valve 36 of the high-pressure oil passage 44 and the solenoid valve 7 interposed in the signal pressure passage 11 are controlled to be opened and closed to select whether to operate the pump motor 43 of the regenerative device 30.

Next, the control operation of the controller 10 will be described with reference to the flowchart of FIG.

First, at step 50, the signal pressure P from the pressure sensor 6 is read, and at step 51, whether the signal pressure P exceeds a preset pressure P ₀ , that is, whether the driver has stepped on the brake pedal 1 or not. To determine. If the brake pedal 1 is depressed in this determination, the process proceeds to step 52, and if not, the process proceeds to step 61. When the pressure accumulation level L of the accumulator 37 is read from the pressure sensor 33 in step 52, it is determined in step 53 whether the pressure accumulation level L does not exceed a predetermined maximum level, that is, whether the accumulator 37 is within the allowable pressure. Here, if the accumulator 37 is within the allowable pressure, the process proceeds to step 54, and if not, the process proceeds to step 61.

In step 54, the shift position signal is read from the shift lever 34, and it is determined in step 55 whether the vehicle is in the forward position where the kinetic energy can be recovered. If the result of this determination is YES, the vehicle speed sensor 32 is determined in step 56.
The vehicle speed signal V is read from. In step 57, it is determined whether or not the vehicle speed V is a vehicle speed at which the kinetic energy exceeding the preset minimum speed Vmin and less than the maximum speed Vmax that is the maximum allowable rotation speed of the pump motor 43 can be recovered, and the determination result is YES. If there is, the kinetic energy is recovered as described later in step 58, while if NO, step 61.
By the following processing, the regenerative device 30 is stopped and the service brake is applied.

The electromagnetic clutch 42 is the regenerative device 30.
Is connected when the vehicle starts up, and the vehicle speed V is the maximum speed Vmax.
It will continue to be connected until it exceeds.

When the solenoid valve 36 is opened in step 58, in step 59 the pump motor 4 is driven by the oblique shaft drive device 35.
The oblique shaft (not shown) of 3 is driven to a tilt angle on the pump side according to the depression angle of the brake pedal 1, and the driving force of the wheels 40 pumps and accumulates the hydraulic oil in the tank 38 to the accumulator 37 to collect kinetic energy. At the same time, the solenoid valve 7 is energized and closed in step 60, and the signal pressure passage 11 is closed.
Shut off. In the inoperative range of the brake valve 2, the service brake is stopped and braking is performed by the regenerative device 30, but when the depression angle of the brake pedal 1 increases and exceeds the inoperative range, the double check valves 4, 5 are released from the brake valve 2. Since the signal pressure passage 11 is cut off at this time, the air of the brake valve 2 is selected for the brake circuits 20 and 21, and the operation of the service brake is started to accelerate the braking.

On the other hand, when the regenerative device 30 is judged to be NO in the above-mentioned steps 51, 53, 55 and 57, the electromagnetic valve 7 is opened in the step 61 by shutting off the energization. Air from the auxiliary brake valve 3 is applied to the relay valve 8 from the signal pressure passage 11, and if the brake valve 2 is in the inoperative range, braking by the service brake can be started by the output of the relay valve 8. In step 62, the tilt angle of the oblique drive device 35 is set to 0 (the neutral position).
Then, the pump motor 43 is stopped (idling), and in step 63, the electromagnetic valve 36 of the high-pressure oil circuit 44 is closed to stop the regenerative device 30.

When the brake pedal 1 is operated while the regenerative device 30 in steps 61 to 63 is stopped, the depression angle θ of the brake pedal 1 and the air pressure P applied to the double check valves 4 and 5 are: Relationship changes as shown in FIG.

The depression angle θ of the brake pedal 1 is θ ₁
The area below is an inoperative area in which the brake valve 2 does not operate, and the signal pressure corresponding to the depression angle θ of the brake pedal 1 is applied from the auxiliary brake valve 3 to the relay valve 8 via the signal pressure passage 11, and the relay valve 8 is relayed. The valve 8 supplies the air pressure P ₃ corresponding to this signal pressure to the double check valves 4 and 5. At this time, since air from the brake valve 2 is not supplied to the primary circuit 18 and the secondary circuit 19, the double check valves 4 and 5 output the air pressure P ₃ from the relay valve 8 to the brake circuits 20 and 21 for braking. Is done.

When the depression angle θ exceeds θ ₁ and the brake pedal 1 is depressed, the supply of air pressures P ₁ and P ₂ from the brake valve 2 to the primary circuit 18 and the secondary circuit 19 is started in accordance with the depression angle θ. On the other hand, the air pressure P ₃ from the relay valve 8 maintains a predetermined pressure, and the relay is the same as above until the depression angle θ _{2 at} which the air pressures P ₁ and P ₂ from the brake valve 2 exceed the air pressure P _3. Valve 8
Air pressure P _{3 from} is applied to the service brake.

The depression angle θ of the brake pedal 1 is θ ₂
By weight, since the air pressure P _1, P ₂ from the brake valve 2 exceeds the air pressure P ₃ from the relay valve 8, the output of the double check valve 4, 5 is switched respectively to the air P _1, P _2, air pressure P _1, P ₂ from the brake valve 2 is supplied to the brake circuits 20 and 21 deceleration of the vehicle is performed.

On the other hand, during braking when the regenerative device 30 operates, the air pressure P ₃ from the relay valve 8 is not output because the solenoid valve 7 is closed, and the depression angle θ of the brake pedal 1 exceeds θ _1. Air pressure P ₁ from the brake valve 2,
P ₂ is selected by the double check valves 4 and 5 and supplied to the service brake.

When the operation of the regenerative device 30 is stopped in the inoperative region of the brake valve 2 due to the determination result of the above step 51, 53, 55 or 57, the controller 10 stops energizing the solenoid valve 7. In order to open the valves, the double check valves 4 and 5 are connected to the air pressure P from the relay valve 8.
₃ is output to the brake circuits 20 and 21, and the service brake is operated to decelerate. The switching from the regenerative brake to the service brake is performed even when the energization of the solenoid valve 7 is cut off. For example, when the controller 10 has a failure and the energization of the solenoid valve 7 is stopped, the solenoid valve 7 is opened. In order to perform the valve operation, the brake valve 2 can be reliably braked by the air from the relay valve 8 in the inoperative region of the brake valve 2, and the fail-safe can be secured.

As described above, even in the inoperative region of the brake valve 2 in which the regenerative device 30 does not operate, the signal pressure from the auxiliary brake valve 3 causes the air pressure P from the relay valve 8.
_{Since 3} is supplied and the service brake is actuated to perform braking, the response of the braking force in the inoperative region of the brake valve 2 set in the initial operating region of the brake pedal 1 can be improved, and the high pressure side is always available. Since the double check valves 4 and 5 for selecting is used, it is possible to supply the higher one of the outputs of the brake valve 2 or the relay valve 8 to the service brake, and even when the regenerative device 30 is not operating. The reliability of can be improved.

Although the double check valves 4 and 5 are adopted as the switching valves in the above-mentioned embodiment, they may be constituted by a shuttle valve or the like (not shown) that automatically selects the high pressure side. Further, in the above embodiment, the brake circuits 20 and 21
Although it is constituted by a full air brake, it may be constituted by an air over hydraulic brake or the like which is a combination of hydraulic pressure and air (not shown).

[0032]

As described above, according to the present invention, air is supplied from the relay valve by the signal pressure from the second brake valve even in the inoperative region of the first brake valve in which the regenerative device does not operate. Since the service brake is operated, the response of the braking force in the initial operation range of the brake pedal can be improved, and the switching valve for selecting the high pressure side is provided. Therefore, the first brake valve or the second brake It is possible to supply the higher pressure of the output of the relay valve driven by the valve to the service brake, and it is possible to ensure the reliability of the brake device even when the regenerative device is stopped.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a regenerative device of the same.

FIG. 3 is a flowchart showing an example of control by a controller.

FIG. 4 is a diagram showing a relationship between a depression angle of a brake pedal and an air pressure of a brake valve.

[Explanation of symbols]

 2 Brake valve 3 Auxiliary brake valve 4, 5 Double check valve 7 Solenoid valve 8 Relay valve 10 Controller 11 Signal pressure circuit 18 Primary circuit 19 Secondary circuit 14, 15 Air reservoir 20, 21 Brake circuit 30 Regenerative device

Claims (1)

[Claims] 1. A brake device comprising a regenerative device for transmitting a rotational force of a wheel to a pressurizing means to store a pressure for energy regeneration in an accumulator at the time of braking when the brake pedal is operated. Is a first brake valve having an inoperative region where braking pressure is not generated, and a second brake valve which outputs a pressure from a brake pressure source in the inoperative region of the first brake valve in conjunction with the operation of the brake pedal. Brake valve, a relay valve that outputs a pressure from a brake pressure source using the output of the second brake valve as a signal pressure, and the relay valve or the first valve.
Switching valve that selectively outputs the higher pressure to the service brake among the outputs of the brake valve, the valve that opens and closes the signal pressure passage to the relay valve, and the signal pressure passage that detects the operation of the regenerative device. And a control means for closing the valve.