JPH0692210A - Regenerative braking device of vehicle - Google Patents

Abstract

PURPOSE:To improve the responsiveness of a service brake and ensure reliability while a regenerative brake rests. CONSTITUTION:A regenerative braking device comprises a brake valve 2 having an inoperative range where the braking pressure is not generated in the initial operating range of a brake pedal 1, an auxiliary brake valve 3 for outputting pressure from an air reservoir 14, interlocking with the operation of the brake pedal 1 even in the inoperative range of the brake valve 2, and double check valves 4, 5 for selectively outputting a higher pressure of output of the brake valve 2 and output of the auxiliary brake valve. Further, the regenerative brake comprises relay valves 8, 9 for taking the output from the double check valves 4, 5 as signal pressure and outputting the pressure from the air reservoirs 14, 15 to a service brake, a solenoid valve 7 interposed between the auxiliary brake valve 3 and the double check valves 4, 5 for opening and closing a signal pressure passage 11, and a controller 10 for detecting the operation of a regenerative device 30 to close the solenoid valve 7.

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 that recovers kinetic energy and uses it as driving energy when the vehicle is decelerated.

[0002]

2. Description of the Related Art Conventionally, regenerative braking devices of this type have been disclosed in, for example, Japanese Unexamined Patent Publication 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.
When the vehicle is decelerated, 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. A second brake valve that outputs the pressure from the switch, a switching valve that selectively outputs the higher pressure of the outputs of the first brake valve and the second brake valve, and the output from the switching valve. A relay valve that outputs the pressure from the brake pressure source to the service brake as a pressure, and the passage is opened and closed by being interposed between the second brake valve and the switching valve. Comprising a valve that, and control means for closing the detection to the valve to during operation of the regeneration device.

[0008]

Therefore, in the inoperative region of the first brake valve when the regenerative device is inoperative, the control means opens the valve of the signal pressure passage to output a signal corresponding to the pressure from the second brake valve. Apply pressure to the switching valve. The switching valve is the first
Since there is no pressure from the brake valve, the pressure output from the second brake valve is selected and output as a signal pressure to the relay valve. The relay valve outputs the pressure from the brake pressure source according to the signal pressure from the switching valve. 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 switching valve has the first and second switching valves.
Since the pressure is not supplied from the brake valve and the signal pressure is not applied to the relay valve, the service brake does not operate and braking is performed only by the braking force of the regenerative device.

When the brake pedal is further depressed beyond the inoperative range of the first brake valve, the first brake valve operates and the output of this first brake valve is the second signal of the re-signal pressure circuit. When the pressure becomes higher than the output of the brake valve, the switching valve selects the output of the first brake valve, and the relay valve outputs the pressure corresponding to the signal pressure from the first brake to the service brake to perform braking.

[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 via a normally-open solenoid valve 7 driven by the controller 10 to one input port of each of the double check valves 4 and 5 having two input ports as a switching valve. A pressure sensor 6 connected to a controller 10 is provided upstream of the electromagnetic valve 7 in the signal pressure passage 11, and the controller 10 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 other input ports of the double check valves 4 and 5, respectively, and the output ports thereof are respectively provided to the relay valves 8 provided downstream,
9 is connected to the signal pressure side.

The relay valve 8 receives the air supplied from the air reservoir 14 and outputs the air corresponding to the signal pressure supplied from the double check valve 4 to the brake circuit 20. Similarly, the relay valve 9 receives the air supply from the air reservoir 15 and outputs the air according to the signal pressure supplied from the double check valve 5 to the brake circuit 21.

The brake circuit 20 connected downstream of the relay valve 8 drives the brake chamber 24 via the relay valve 22, while the air in the brake circuit 21 connected to the relay valve 9 passes through the quick release valve 23. To drive the brake chamber 25. The brake chambers 24 and 25 are connected to a brake drum (not shown) to form a service brake for braking 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. The accumulator 37 is provided with a pressure accumulation level sensor 33 that detects the amount of regenerated energy as the position of the piston 37a.

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 accumulation level sensor 33 for detecting a pressure accumulation level of an accumulator 37, and a signal pressure shown in FIG. The signal pressure P from the pressure sensor 6 that detects the pressure in the passage 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. Accumulation level sensor 3 in step 52
When the accumulated pressure level L of the accumulator 37 is read from 3, it is determined in step 53 whether the accumulated pressure 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 gear clutch 42a is connected when the regenerative device 30 is started up, and remains connected until the vehicle speed V exceeds the maximum speed Vmax.

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 the 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 air is added to the signal pressure passage 11 at this time, the brake circuits 20 and 21 are supplied with air from the relay valves 8 and 9 in accordance with the pressure controlled by the brake valve 2, and the service brake is also activated. And braking is promoted.

On the other hand, when the regenerative device 30 for which the judgment results of the above steps 51, 53, 55 and 57 are NO, is not operated, the energization of the solenoid valve 7 is cut off and opened at step 61, and the signal pressure is increased. The air in the auxiliary brake valve 3 is supplied to the double check valves 4 and 5 by opening the passage 11, and if the brake valve 2 is in the inoperative range at this time, the auxiliary brake valve 3 output from the double check valves 4 and 5 Depending on the signal pressure, the relay valves 8 and 9 are connected to the brake circuit 20,
Air can be supplied to 21 to start braking by the service brake.

In step 62, the tilt angle of the oblique shaft drive device 35 is set to 0 (the neutral position), the pump motor 43 is stopped, and in step 63, the electromagnetic valve 36 of the high pressure oil circuit 44 is closed to operate the regenerative device 30. Pause.

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 a non-operation area where 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 double check valves 4 and 5 via the signal pressure passage 11. At this time, since the primary circuit 18 and the secondary circuit 19 are not supplied with air from the brake valve 2, the double check valves 4 and 5 apply the air pressure P ₃ from the signal pressure passage 11 to the relay valves 8 and 9. Then, the relay valves 8 and 9 output air corresponding to the air pressure P ₃ to the brake circuits 20 and 21 to perform braking.

When the depression angle θ exceeds θ ₁ and the brake pedal 1 is further depressed, 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. while the air pressure P ₃ of the auxiliary brake valve 3 for holding a predetermined pressure, the air pressure P _1, P ₂ from the brake valve 2 to the depression angle theta ₂ which exceeds the air pressure P ₃ and the Similarly the air pressure P ₃ of the auxiliary brake valve 3 is added as a signal pressure to the relay valve 8, 9.

When the depression angle θ of the brake pedal 1 exceeds θ ₂ where the air pressures P ₁ and P ₂ are larger than the air pressure P ₃ ,
Since the air pressure P _1, P ₂ from the brake valve 2 exceeds the air pressure P ₃ of the auxiliary brake valve 3, the output of the double check valve 4, 5 is switched respectively to the air P _1, P _2, brake valve 2 Air from the relay valves 8 and 9 is applied to the brake circuits 20 and 21 according to the air pressures P ₁ and P ₂ from
Is supplied to the vehicle and the vehicle is decelerated.

On the other hand, during braking when the regenerative device 30 operates, the signal pressure passage 11 is closed because the solenoid valve 7 is closed, and the air pressure P ₃ from the auxiliary brake valve 3 is not output, and the brake pedal 1 While the depression angle θ is up to θ ₁ , the vehicle is decelerated by the braking force of the regenerative device 30,
Air pressure P _1, P ₂ from the brake valve 2 when the depression angle theta of the brake pedal 1 exceeds theta ₁ is selected by the double check valve 4, 5 is supplied to the relay valve 8 and 9, the air pressure P1, P ₂ The air pressure with the signal pressure as the brake circuit 2
Added to 0, 21.

When the operation of the regenerative device 30 is stopped in the inoperative region of the brake valve 2 due to the judgment result of the above step 51, 53, 55 or 57, the controller 10 stops the energization of the solenoid valve 7. In order to open the valve, the signal pressure passage 11 is opened, and the double check valves 4 and 5 receive the air pressure P ₃ from the auxiliary brake valve ₃ into the relay valve 8 and
To the brake circuit 2 according to the air pressure P ₃
0, 21 is supplied, the service brake is activated, and deceleration is performed. This switching from the regenerative brake to the service brake is performed even when the solenoid valve 7 is de-energized,
For example, when a failure occurs in the controller 10 and the energization of the solenoid valve 7 is stopped, the normally open solenoid valve 7 opens, so that the air from the auxiliary brake valve 3 is in the inoperative region of the brake valve 2. As a result, it is possible to surely apply the braking and to secure the fail safe.

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 via the double check valves 4 and 5 causes the air to flow from the relay valves 8 and 9. Is supplied and the service brake is actuated to perform braking. Therefore, 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 maintained. Since the double check valves 4 and 5 to be selected are provided, the output of the brake valve 2 or the auxiliary brake valve 2 having a higher voltage can be supplied as a signal to the relay valves 8 and 9, and the regenerative device 30 can be provided. The reliability of the brake device can be improved even when the vehicle is at rest.

Although the double check valves 4 and 5 are adopted as the switching valves in the above embodiment, they may be constituted by a shuttle valve or the like which automatically selects the high pressure side, although not shown.

Further, in the above embodiment, the brake circuit 2
Although 0 and 21 are constituted by full air brakes, they may be constituted by air over hydraulic brakes or the like which are a combination of hydraulic pressure and air (not shown).

[0034]

As described above, according to the present invention, the switching valve selects the signal pressure from the second brake valve even in the inoperative range of the first brake valve in which the regenerative device does not operate. Since the air is supplied from the relay valve to operate the service brake, 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. Among the outputs of the second brake valve, the higher pressure can be supplied to the relay valve as a signal pressure, and the reliability of the brake device can be ensured 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, 9 Relay valve 10 Controller 11 Signal pressure passage 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 switching valve that selectively outputs the higher pressure of the outputs of the first brake valve or the second brake valve, and a pressure from a brake pressure source using the output from the switching valve as a signal pressure. To a service brake, a valve that is interposed between the second brake valve and the switching valve to open and close a passage, and the operation of the regenerative device. A regenerative braking device for a vehicle, comprising: a control unit that detects the time of movement and closes the valve.