JPH02120147A - Brake energy regenerater for vehicle - Google Patents

Abstract

PURPOSE:To keep off any misstarting or the like of a vehicle due to a hydraulic circuit when stepping on an accelerator pedal by mistake by controlling the hydraulic circuit so as to make it unoperatable or to turn an actuator relay to OFF after disengaging an electromagnetic clutch when a key switch is turned off. CONSTITUTION:When a selector control command for energy recovery is given to a circuit selector valve 4 constituting a hydraulic circuit together with both high and low pressure accumulators 5, 6 and a pump-motor 3, from a microprocessing unit 15, an electromagnetic clutch 2 is set to a connected state, and a tilting angle of the pump-motor 3 conformed to the operated variable of a brake pedal. With this control, oil in the low pressure accumulator 6 is upper of its pressure and stored in the high pressure accumulator 5. When a key switch is turned to OFF, the tilting angle of the motor 14 is brought to zero, or the circuit selector valve 4 is set to a valve-closed state, or an accumulator relay 40 is turned off after the electromagnetic clutch 2 is controlled to a disengaged state, and a power source is controlled so as to be interrupted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a brake energy regeneration device for a vehicle that recovers deceleration energy of a vehicle and uses it as starting/acceleration energy.

[Conventional technology]

Of the kinetic energy lost when the vehicle decelerates, the amount that is mainly dissipated as heat (brakes, engine) is recovered as hydraulic pressure and stored in an accumulator, and this stored energy is used as starting energy and acceleration energy for the vehicle. PTO (Power-take-
off) Deceleration energy recovery devices for vehicles equipped with an axle equipped with an output device or transfer have been known for a long time, and the oldest one was developed in 1976 by the British C1J.
It was announced that Lawrence Corporation was developing a bus using Pritish Leyland's bus, and since then, various research and developments have been carried out in Europe and the United States, and recently, Japanese Patent Application Laid-Open No. 15128/1983, It is disclosed in Japanese Patent Application Laid-open No. 62-37215 and Japanese Patent Application Laid-open No. 62-3932T.

The latter devices both have a countershaft driven via an engine clutch, a main shaft connected to the wheel drive system, and a multi-stage gear train mechanism that transmits the rotation of the countershaft to the main shaft at different speeds. (hereinafter abbreviated as T/M), a countershaft PTO gear is attached to the countershaft so that it can communicate with the countershaft via a countershaft PTO gear synchronizer, and a mainshaft PTO gear synchronizer is connected to the main shaft by a gear. A multi-speed PTO device having a main shaft PTO gear mounted in a communicable manner through a main shaft PTO gear and a PTO output shaft driven through a drive gear coupled to the main shaft PTO gear;
A pump motor connected to the O axis, a hydraulic circuit that connects the accumulator and the oil tank via the pump motor, an electromagnetic clutch that enables the hydraulic circuit to communicate with the PTO axis, and 1! The accumulator, which controls the magnetic clutch and is connected to the pump motor by a high-pressure oil circuit, and the pump
The motor functions as either a pump or a motor depending on the driving state of the vehicle (i.e., it functions as a pump during deceleration, and the rotational force of the wheels causes hydraulic oil to accumulate in an accumulator via the PTO device, thereby mainly acting as a brake. , a motor that recovers the kinetic energy (hereinafter referred to as brake energy) lost as engine heat and generates rotational force using the hydraulic oil stored in the accumulator during start/acceleration to drive the wheels through the PTO device. The main part is a control means (which functions as a controller).

Is this the control of a deceleration energy recovery device? 11 means: - When starting, when the hydraulic pressure in the accumulator is sufficient, the capacity of the variable displacement motor (tilting angle of the swash plate or slant shaft) is controlled according to the amount of depression of the accelerator pedal, and the 1i magnetic clutch is connected. During this time, when the vehicle speed exceeds the set speed corresponding to the gear selected by the driver, the engine clutch is connected to drive the engine and the PT○ device is shifted. Control is performed to turn off the countershaft synchronizer that was on, turn on the main shaft synchronizer, and further perform control to apply hydraulic pressure in accordance with the amount of depression of the accelerator pedal only when the amount of depression of the accelerator pedal is large at that time.

■When braking, the electromagnetic clutch is connected and a tilt angle control signal (pump capacity control signal) corresponding to the depression of the brake pedal is applied to the pump motor to operate the pump.
At the same time, control is performed to disengage the engine clutch.

In this case, the control means, based on the control program, recovers the amount of braking energy consumed by engine braking, and also disconnects the engine from the wheel drive system when driving by motor, so that the clutch of the engine is disconnected. When using the motor and engine together or starting/accelerating only with the engine,
It is controlled so that the

[Problem to be solved by the invention]

In the case of such conventional technology, even when the vehicle is stopped and the driver turns off the key switch, the actuator relay that ultimately turns off the power to the entire system is still energized unless a power-off signal is simultaneously generated from the CPU. It is common to be in a state of

That is, as shown in FIG. 3, in the actuator relay 40 used in automobiles, etc., when the key switch 41 is turned on, an "H" level output is given to the NOR gate 43, so the NOR gate 43 is connected to the output of the MPU 42. Regardless, the output is at the "°L" level, so the transistor 44 is turned on, the relay coil 40a is energized, and the contact 40b is connected, so that 24V is applied to the entire vehicle.
Gives power.

On the other hand, when the key switch 41 is turned off, the output of the key switch 41 becomes "L" level, but in this state, M
Since the output of the PU 42 remains at the H level, the transistor 44 remains on and therefore the actuator relay 40 remains energized. This is because it is necessary to provide power.

Therefore, from the moment the key switch 41 is turned off, the MPU 4
There is a problem in that if the driver depresses the accelerator pedal within a certain period of time until the output of No. 2 reaches the Ln level, the hydraulic circuit will work, causing an unexpected accident.

Therefore, an object of the present invention is to realize a brake energy regeneration device for a vehicle that can always prevent the hydraulic circuit from working when the key switch is turned off.

[Means to solve the problem]

In order to achieve the above object, in the vehicle brake energy regeneration device according to the present invention, when the hydraulic circuit, the actuator relay, and the key switch are turned off, the tilting angle of the pump/motor in the hydraulic circuit is zero. or close the circuit valve in the hydraulic circuit, or turn off the actuator relay and turn off the power after controlling the electromagnetic clutch that connects the cough pump motor and the PTO device to the disconnected state. and a control means.

[For production]

In the present invention, the control means detects when the driver turns off the key switch and first sets the tilt angle of the pump/motor in the hydraulic circuit to zero in order to prevent the hydraulic circuit from operating. Or close the circuit valve in the hydraulic circuit. Alternatively, the electromagnetic clutch connecting the pump motor and the PTO device connected to the wheels may be controlled to be in a disconnected state.

A signal is generated to turn off the tuator relay, and the entire vehicle is powered off.

As a result, in order to ensure safety even if the key switch is turned off when stopping or driving, the actuator relay is turned off because the control is such that the power is turned off after all the hydraulic systems are returned to a safe state. Even if the accelerator pedal is pressed before the power is turned off, there is no danger of hydraulic start.

〔Example〕

FIG. 1 is a block diagram of an embodiment of a brake energy regeneration device for a vehicle to which the present invention is applied, and l is an axle 2
0 is a PTO device which extracts the driving force of the wheels 21 as hydraulic braking force via 0, an electromagnetic clutch 2 is used to communicate the driving force transmission between the PTO device 1 and the pump/motor 3 that performs pump operation during braking; 4 is a circuit switching valve as a circuit valve; 5 is a high-pressure accumulator; 6 is a low-pressure accumulator that constitutes a hydraulic circuit together with the pump/motor 3, circuit switching valve 4, and high-pressure accumulator 5; 11 is a tilt angle sensor for the pump/motor 3. It is. Additionally, pressure sensors 12 and 13 are installed between the circuit switching valve 6 and the pump/motor 3, and between the pump/motor 3 and the circuit switching valve 4, respectively, to control the hydraulic pressure of each part. It is sent to the MPU 15. The MPU 15 performs tilting angle (capacity) control of the pump motor 3, switching/closing control of the circuit switching valve 4, and close contact control of the electromagnetic clutch 2. Note that 22 is a transmission (T/M) that includes the PTO device 1 and is connected to the engine (not shown) by an automatically controlled engine clutch 23; Scraping allows for disconnection of the engine during energy recovery/regeneration.

The operation of the brake energy regeneration device of this embodiment will be explained below with reference to the flowchart shown in FIG.

First, the MPU 15 determines the state of the key switch 41 (step Sl). As a result of this determination, the key switch 41
When the brake is turned on, hydraulic energy control and normal brake control are executed (step S6).

Here, these controls will be briefly explained.

■Energy recovery mode Now, when the driver depresses the brake pedal (not shown) and an energy recovery mode command is given to the MPU 15, the MPU 15 controls the electromagnetic clutch 2 to the connected state and then controls the circuit switching valve 4. The rotation angle of the pump/motor 3 is controlled according to the amount of depression of the brake pedal.

As a result, the oil in the low pressure accumulator 6 is accumulated in the high pressure accumulator 5 through the route of circuit switching valve 4 → pump/motor 3 → circuit switching valve 4 → high pressure accumulator 5.

■Energy raw mode The hydraulic energy stored in the high-pressure accumulator 5 as described above is activated when the driver depresses the accelerator pedal (not shown), for example, and the energy regeneration mode command is set to M.
The MPU 15 connects the electromagnetic clutch 2 and controls the circuit switching valve 4 to switch.
The tilt angle of the pump motor 3 is controlled according to the amount of depression of the accelerator pedal.

Incidentally, in the hydraulic circuit operations of (1) and (2) above, the engine clutch 22 is normally automatically disengaged by a control signal from the MPU 15. In the case of a normal automatic transmission vehicle that does not use an automatic clutch, the gear position is controlled to be neutral.

■゛Constant brake 11' mode In addition to this, there is a mode that does not use the hydraulic circuit at all. In this case, the tilting angle of the pump motor 3 is set to O (capacity O).
to prevent the pump/motor 3 from rotating even if pressure is applied to the pump/motor 3, and the circuit switching valve 4
is completely turned off (valve closed state), the hydraulic circuit is cut off, the electromagnetic clutch 2 is turned off, the pump motor 3 is disconnected from the PTO device 1 and the wheels 21, and the hydraulic brake force is completely removed from the wheels 21. Cut off.

Returning to step S1 in FIG. 2, when the key switch 41 is turned off, the following control to stop all controls is performed.

First, the tilt angle of the pump/motor 3 is set to "0" to set the capacity to "0", that is, the pump/motor output to "0" (step 2).

In this case, the tilt angle of the pump motor 3 is exactly "0"'
If it is not, an output will be generated. Therefore, it is preferable to obtain the actual tilt angle signal from the tilt angle sensor 11 into the MPU 15 and apply feedback control to achieve the tilt angle °0''.

Next, the valve position of the circuit switching valve 4 is controlled to a closed state as shown in the figure in which all ports are disconnected (Step S3).

In this case as well, unless the circuit switching valve 4 is actually closed, there is a possibility that the hydraulic circuit from the high pressure accumulator 5 to the low pressure accumulator 6 via the pump/motor 3 will be activated.

Therefore, it is preferable to confirm that the circuit switching valve 4 has been completely controlled.

That is, after the MPU 15 controls the circuit switching valve 4 to close it, the pump of the circuit switching valve 4 is closed.
The absolute value IPlz P+, l of the pressure difference between the pressure sensors 12 and 13 provided on the motor side is determined, and this absolute value is
It is only necessary to determine whether the constant pipe resistance pressure P inside the motor 3 is higher or lower.

When IP+tPI31 is substantially equal to the line resistance pressure P, this indicates that the oil pressure difference across the pump motor 2 is equal to the line resistance pressure of the pump motor 2 itself. indicates that the circuit switching valve 4 has completed closing.

After the hydraulic circuit is rendered inoperable by controlling the circuit switching valve 4 and pump motor 3 that constitute the hydraulic circuit, the electromagnetic clutch 2 is further controlled to be disengaged (step S4). The second control may be open loop control.

This means that all control of the hydraulic system is stopped, and the vehicle will not start even if the driver depresses the accelerator pedal.

Thereafter, the MPU 15 generates an output signal to turn off the actuator relay (see FIG. 3), which de-energizes the actuator relay, thereby cutting off all power to the vehicle.

In the above embodiment, a circuit switching valve has been described as a circuit valve, but depending on the type of pump/motor, a simple circuit cutoff valve that does not require switching the hydraulic circuit can be used in the same way.

In addition, if at least one of the pump/motor tilt angle control, the circuit switching valve closing control, and the electromagnetic clutch disengagement control is performed, operations such as hydraulic start after the key switch is turned off can be prevented. Can be done.

〔Effect of the invention〕

As described above, the brake energy regeneration device for a vehicle according to the present invention is configured to disable the hydraulic circuit system or disconnect the electromagnetic clutch when the key switch is turned off, and then turn off the actuator relay. Therefore, even if the accelerator pedal is pressed by mistake, the risk of the vehicle starting due to the hydraulic circuit is eliminated, and the vehicle can be kept in a safe state.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an embodiment to which the vehicle brake energy regeneration device according to the present invention is applied, FIG. 2 is a flow chart diagram showing the operation at the time of a full control stop according to the present invention, and FIG. 1 is a diagram showing a control circuit of a generally well-known actuator relay. In Fig. 1, l is a PTO device, 2 is an electromagnetic franc,
3 is a pump/motor, 4 is a circuit switching valve, 5 is a high pressure accumulator, 6 is a low pressure accumulator, 11 is a tilt angle sensor, 12.13 is an oil pressure sensor, 15 is an MPLI, 40 is an actuator relay, and 41 is a key switch. show. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] When the hydraulic circuit, actuator relay, and key switch are turned off, the tilt angle of the pump motor in the hydraulic circuit is made zero, the circuit valve in the hydraulic circuit is closed, or A brake energy regeneration device for a vehicle, comprising: a control means that turns off the actuator relay and turns off the power after controlling an electromagnetic clutch that connects a pump motor and a PTO device to a disengaged state.