JP3545204B2 - Energy regenerative braking system for vehicles - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle energy regenerative braking device that recovers kinetic energy during deceleration of a vehicle and uses the kinetic energy as drive energy, and more particularly to a technique for increasing the recovery rate of kinetic energy and promoting effective use of kinetic energy.
[0002]
[Prior art]
Conventionally, as this type of energy regenerative braking device, for example, devices disclosed in Japanese Patent Application Laid-Open Nos. 2-117432 and 6-56008 are known.
In these devices, a pump motor is connected to a wheel drive system via an electromagnetic clutch, and one port of the pump motor is connected to a high-pressure side accumulator, and the other port is connected to a low-pressure side oil tank (pressurized type). Connected to When the vehicle decelerates, the pump motor is connected to the wheel drive system to operate as a pump, thereby braking the wheel drive system with the pump motor as a load, and accumulating high-pressure oil in the accumulator to reduce the kinetic energy of the vehicle. to recover. The high-pressure oil accumulated in the accumulator in this way serves as an energy source for connecting a pump motor to a wheel drive system to act as a motor when the vehicle starts, for example, and is used as drive energy for the wheel drive system.
[0003]
Furthermore, in the former conventional device, in order to recover as much kinetic energy of the vehicle as possible, the engine clutch is disengaged when the exhaust brake or the like is operated to separate the engine from the drive wheels, thereby reducing the equivalent torque of the exhaust brake. I was trying to collect it.
However, in the conventional energy regenerative braking device, it is necessary to disconnect the engine clutch every time in order to recover the substantial torque of the exhaust brake during the operation of the exhaust brake, and torque fluctuation occurs due to the on / off of the engine clutch. However, the ride comfort may be reduced.
[0004]
Accordingly, the present applicant has previously described in Japanese Patent Application No. 8-155578 (see Japanese Patent Application Laid-Open No. 10-958) the equivalent torque of the exhaust brake without disengaging the engine clutch when the operating condition of the exhaust brake is satisfied. Energy regenerative braking device that can recover the energy.
Specifically, when it is determined that the operation conditions of the exhaust brake are satisfied and it is determined that the pressure accumulation is possible, the operation of the exhaust brake is temporarily interrupted, and the engine and the drive wheels are disconnected each time. The kinetic energy recovery rate of the vehicle can be improved without disconnection.
[0005]
[Problems to be solved by the invention]
In such prior art, at the time of full pressure accumulation or the like, the regenerative brake operation equivalent to the exhaust brake is stopped, and the operation is switched to the normal operation of the exhaust brake. The feeling and the attitude of the vehicle body were affected, especially on frozen road surfaces in winter when the road surface was slippery.
[0006]
Therefore, the present invention provides a vehicle in which both the safety and the energy saving effect can be achieved without affecting the brake feeling and the vehicle body posture by adopting a configuration in which the exhaust brake characteristics can be selectively switched according to the driver's intention. It is an object of the present invention to provide an energy regenerating brake device.
[0007]
[Means for Solving the Problems]
For this reason, the invention according to claim 1 includes an exhaust brake for increasing the internal resistance of the engine by means of a throttle valve interposed in the exhaust passage of the engine to decelerate the engine, and the torque of the wheel drive system during braking of the vehicle. An energy regeneration brake device that drives a pump motor to recover the kinetic energy of the vehicle by pumping the working fluid in the low pressure side oil tank to the high pressure side accumulator and accumulating the pressure,
Operating condition determining means for determining whether the operating condition of the exhaust brake is satisfied,
Operation interruption means for interrupting the operation of the exhaust brake;
Switching means for switching between interlocking and non-interlocking of the exhaust brake and the regenerative brake;
Accumulation possible determination means for determining whether or not accumulation of the working fluid to the high pressure side accumulator is possible,
The operating condition determining means determines that the operating condition of the exhaust brake has been satisfied, and the pressure storing possibility determining means determines that the pressure can be stored, and the switching means is switched to an interlocking side between the exhaust brake and the regenerative brake. At the same time, the regenerative brake is operated and the operation of the exhaust brake is interrupted by the operation interrupting means, while the operating condition of the exhaust brake is not satisfied, and the switching means switches to the non-interlocking side of the exhaust brake and the regenerative brake. Control means for stopping the operation of the regenerative brake and activating the exhaust brake, at any one of the time when the pressure accumulation is determined to be impossible, and
Is characterized by including.
[0008]
In this case, the operating condition determining means determines that the operating condition of the exhaust brake is satisfied, and the pressure storing possibility determining means determines that the pressure can be stored, and the switching means switches between the exhaust brake and the regenerative brake. When switched to the interlocking side, the regenerative brake is operated and the operation of the exhaust brake is interrupted by the operation interrupting means. Therefore, the kinetic energy of the vehicle can be reduced without disconnecting the engine and the drive wheels every time as in the conventional case. Is improved.
[0009]
If the switching means is switched to the non-interlocking side between the exhaust brake and the regenerative brake, only the exhaust brake operates at all times.
That is, the interlocking and non-interlocking of the exhaust brake and the regenerative brake are selected by the driver's judgment or the like, and the switching means is switched to the non-interlocking side of the exhaust brake and the regenerative brake as described above. Only the regenerative brake operation and the exhaust brake operation are interrupted, and only the exhaust brake is activated, so that there is no sudden switching between them, and the brake characteristics do not suddenly change. There is no effect on the body posture.
[0010]
According to a second aspect of the present invention, the operating condition determining means includes an opening degree detecting means for detecting an accelerator opening degree and a rotational speed detecting means for detecting an engine rotational speed. When the engine speed is equal to or higher than a predetermined idle speed, it is determined that the operating condition of the exhaust brake is satisfied.
With this configuration, when the accelerator opening detected by the opening detecting means is 0 and the engine rotational speed detected by the rotational speed detecting means is equal to or higher than the predetermined idle rotational speed, the operating condition determining means determines whether the exhaust gas is exhausted. Since it is determined that the brake operating condition is satisfied, a condition that requires the operation of the exhaust brake is detected.
[0011]
According to a third aspect of the present invention, when the throttle valve is driven by an electric means, the operation interrupting means is a means for interrupting power supply to the electric means.
In this case, since the power supply to the throttle valve driven by the electric means is cut off, the operation of the exhaust brake is temporarily interrupted with a simple configuration without requiring complicated control or a circuit. You.
[0012]
According to a fourth aspect of the present invention, the throttle valve is driven by an actuator driven by air, and the operation interrupting means is means for interrupting the supply of air to the actuator. did.
In this case, the air supply to the actuator driven by the air is shut off, so that the operation of the exhaust brake is temporarily interrupted with a simple configuration without requiring any complicated control or circuit.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a system diagram showing one embodiment of an energy regenerating brake device according to the present invention.
The output shaft 3 of the transmission 2 that shifts the rotation of the engine 1 to a predetermined rotation speed has a rear wheel 5 serving as a drive wheel via a differential gear 4 and a speed reducer intermittently controlled by a control unit 6 containing a microcomputer. The pump motor 8 is connected via a switch 7. A high-pressure accumulator 10 and a pressurized oil tank 11 are connected to the pump motor 8 via a circuit valve 9 that is switched by the control unit 6.
[0014]
In addition, an exhaust brake 12 is provided that reduces the opening area of the exhaust passage 1a of the engine 1 to increase the internal resistance of the engine 1 to exert a braking effect. That is, the exhaust brake 12 opens and closes the throttle valve 13 provided in the exhaust passage 1 a by an electromagnetic solenoid 15 (electric means) that is driven and controlled by the control unit 6 via the control circuit 14, thereby performing exhaust. A braking effect is achieved according to the opening area of the passage 1a.
[0015]
As sensors for detecting various states that are the basis for determining the control of the energy regenerative braking device having such a configuration, a pressure accumulation level sensor 16 for detecting the amount of regenerated energy as the position of the piston 100 of the high-pressure accumulator 10 and an accelerator opening An opening sensor 17 (opening detecting means, which may be a throttle sensor for detecting a throttle opening) for detecting the degree θ, a rotational speed sensor 18 (rotating speed detecting means) for detecting the rotational speed Ne of the engine, and the like are provided. These signals are input to the control unit 6.
[0016]
Next, a first embodiment of a circuit having the function of the control circuit 14 for performing interruption control of a service brake (foot brake), not shown, and for performing interruption control of the exhaust brake 12 will be described with reference to FIG. The control unit 6 includes an engine control unit 6A for controlling the engine and an energy regenerative braking device control unit (hereinafter abbreviated as “energy regenerating control unit”) 6B for controlling the energy regenerating brake device. The signals from the pressure accumulation level sensor 16 are input to the energy regeneration control unit 6B, and the signals from the opening degree sensor 17 and the rotation speed sensor 18 are input to the engine control unit 6A.
[0017]
The voltage V supplied from the battery is applied to an exhaust brake relay 20 that permits the operation of the exhaust brake 12, a combination switch 21 that is an operation switch of the exhaust brake 12, and a cut relay 22 (which temporarily stops the operation of the exhaust brake). (Operation interruption means), and is supplied to an electromagnetic solenoid 15 that drives the throttle valve 13 to reduce the opening area of the exhaust passage 1a during operation.
[0018]
The exhaust brake relay 20 is actuated by a drive signal from the engine control unit 6A when the accelerator opening θ is 0 and the engine speed Ne is equal to or higher than the idle speed, as will be described later. State (ON). Further, the drive unit of the exhaust brake relay 20 is energized (ON) when the clutch is not operated (when the clutch is connected without stepping on the clutch pedal), and de-energized (OFF) when the clutch is operated. Are interposed in series. That is, the exhaust brake relay 20 is energized (ON) when the accelerator opening θ is 0, the engine rotation speed Ne is equal to or higher than the idle rotation speed, and the clutch is in a non-operating state.
[0019]
The combination switch 21 is energized (ON) when a switch such as a hand lever for operating the exhaust brake 12 installed in the driver's seat is operated, and the cut relay 22 is turned on by a brake relay 24 described later. The electromagnetic solenoid 15 is operated when it is not operated, and the electromagnetic solenoid 15 is operated when it is not operated, and when it is operated, the electromagnetic solenoid 15 is not operated, that is, its operation is temporarily interrupted.
[0020]
The voltage supplied through the exhaust brake relay 20 and the combination switch 21 is supplied in parallel with the cut relay 22 to a drive unit of an exhaust brake request relay 25 that detects that the operating condition of the exhaust brake 12 has been satisfied. The energized state (ON / OFF) of the exhaust brake request relay 25 is input to the energy regeneration control unit 6B. That is, the energy regeneration control unit 6B can determine whether the operating condition of the exhaust brake 12 is satisfied by monitoring the signal from the exhaust brake request relay 25.
[0021]
The drive of the brake relay 24 is controlled by the energy regeneration control unit 6B based on the flowchart of FIG. 3 described later. When the brake relay 24 is activated (ON), the cut relay 22 is activated to activate the electromagnetic solenoid 15. , The service brake valve 26 is activated to temporarily interrupt the air supply to the service brake, and the kinetic energy of the vehicle is effectively recovered by the motor pump 8.
[0022]
Here, a changeover switch 27 is provided as switching means for switching between interlocking and non-interlocking between the exhaust brake 12 and the regenerative brake.
The changeover switch 27 has two switch pieces 27a and 27b interlocked with each other, and one of the switch pieces 27a is provided between a relay contact 25a of the exhaust brake request relay 25 and the energy regeneration control unit 6B. 27c is opened and closed, and a contact 27d provided between the relay coil 22a of the cut relay 22 and the relay contact 24a of the brake relay 24 is opened and closed by the other switch piece 27b.
[0023]
Therefore, by opening both contacts 27b and 27c by the changeover switch 27, the exhaust brake 12 and the regenerative brake are not interlocked, and by closing both contacts 27b and 27c, the exhaust brake 12 and the regenerative brake are connected. Works together.
Next, the drive control of the brake relay 24 by the energy regeneration control unit 6B will be described based on the flowchart of FIG.
[0024]
In step 1 (abbreviated as S1 in the figure, the same applies hereinafter), it is determined whether or not the operating condition of the exhaust brake 12 is satisfied based on a signal from the exhaust brake request relay 25. Specifically, the combination switch 21 is ON, the clutch switch 23 is ON (clutch connection), the accelerator opening θ detected by the opening sensor 17 is 0, and the engine speed Ne detected by the rotation speed sensor 18 is Is higher than the idling rotational speed, the signal from the exhaust brake request relay 25 is turned ON. Therefore, when this signal is ON, the operating condition of the exhaust brake 12 is satisfied, and when OFF, the operating condition of the exhaust brake 12 is not satisfied. to decide. When the operating condition is satisfied, the process proceeds to step 2, and when the operating condition is not satisfied, the process proceeds to step 3 and step 4.
[0025]
In the processing of step 1, the operating condition determining means includes the opening degree sensor 17, the rotational speed sensor 18, the engine control unit 6A, and the exhaust brake request relay 25.
In step 2, whether the changeover switch 27 is interlocking side or non-interlocking side is determined by a circuit. If the changeover switch 27 is switched to interlocking side, the process proceeds to step 5, and if it is switched to non-interlocking side. Then, go to step 3 and step 4.
[0026]
In step 5, it is determined whether or not the pressure can be stored based on the signal from the pressure storage level sensor 16, that is, whether or not the high-pressure accumulator 10 is full. If the pressure can be stored, the process proceeds to step 6; If so, proceed to step 3 and step 4.
Note that, in addition to the signal from the pressure accumulation level sensor 16, a determination condition such as whether or not the oil temperature in the high-pressure accumulator 10 is within a predetermined range may be added. In this processing, the pressure accumulation possible determination means includes the pressure accumulation level sensor 16 and the energy regeneration control unit 6B.
[0027]
In step 6, a process for executing a regenerative braking operation (accumulation brake control) corresponding to the exhaust brake when the operating condition of the exhaust brake 12 is satisfied, the changeover switch 27 is in the interlocking-side switching state, and the pressure can be accumulated. Specifically, the pump motor 8 operates as a pump, switches the circuit valve 9 to recover the kinetic energy to the high-pressure accumulator 10, and connects the speed reducer 7 to transmit the rotation of the rear wheel 5 to the pump motor 8. State. In this way, the rotation of the rear wheel 5 is transmitted to the pump motor 8 via the speed reducer 7, and the torque generated by this rotation drives the pump motor 8, thereby obtaining a braking force and collecting kinetic energy. .
[0028]
In step 7, the brake relay 24 is turned on, and the operation of the exhaust brake 12 is interrupted (exhaust brake cut).
By doing so, the service brake valve 26 is turned on and the service brake is deactivated, and the electromagnetic solenoid 15 is turned off and the exhaust brake 12 is deactivated. Accordingly, the kinetic energy of the vehicle is recovered (consumed) only by the pump motor 8 without disconnecting the engine and the driving wheels every time as in the conventional case, so that the efficiency of recovering the kinetic energy is improved, and the effective use of the kinetic energy is improved. Can be promoted, so that fuel consumption can be reduced.
[0029]
On the other hand, in step 3, the operation of the regenerative brake is stopped, and in step 4, the exhaust brake is operated. That is, only the exhaust brake 12 is operated.
As described above, if the changeover switch 27 is switched to the interlocking side of the exhaust brake and the regenerative brake, the operation of the regenerative brake and the stoppage of the operation of the exhaust brake 12 are executed, while the changeover switch is set to the exhaust brake 12 and the regeneration. If it is switched to the non-interlocking side with the brake, only the exhaust brake operates at all times.
[0030]
That is, the interlocking and non-interlocking of the exhaust brake 12 and the regenerative brake are selected according to the driver's preference and judgment or the like, and the changeover switch 27 is switched to the non-interlocking side of the exhaust brake 12 and the regenerative brake as described above. If this is done, only the exhaust brake 12 will always operate, and sudden switching between the regenerative brake operation and the state in which the operation of the exhaust brake 12 is interrupted, and the state in which only the exhaust brake 12 operates, will not occur, and the brake characteristics will not change. Since it does not occur unexpectedly, there is no effect on the brake feeling and the body posture.
[0031]
In the embodiment of the present invention, the control of the exhaust brake 12 is performed by the circuit shown in FIG. 2. However, according to such an electric circuit, the modification of the current energy regenerative brake control is performed while minimizing the modification. An effect can be obtained. For example, the signals of the clutch switch 23, the combination switch 21, the opening degree sensor 17, the rotation speed sensor 18, and the changeover switch 27 for switching between interlocking and non-interlocking of the exhaust brake 12 and the regenerative brake are respectively provided. The electromagnetic solenoid 15 or the exhaust brake valve 15 ′ may be controlled according to a program input to the control unit 6 and stored in the control unit 6. In this case, various relays such as the brake relay 24 are not required, so that the cost can be reduced.
[0032]
【The invention's effect】
As described above, according to the first aspect of the present invention, when it is determined that the operating condition of the exhaust brake is satisfied, and that the switching means switches the interlocking side between the exhaust brake and the regenerative brake, and that the pressure accumulation is possible. In addition, since the regenerative brake is activated and the operation of the exhaust brake is interrupted, the kinetic energy of the vehicle is consumed only by the pump motor without disconnecting the engine and the drive wheels every time as in the conventional case, The recovery rate of the kinetic energy is improved, and the effective use of the kinetic energy can be promoted. As a result, the fuel consumption can be reduced. In addition, since it is not necessary to separate the engine from the driving wheels, torque fluctuation due to such separation is suppressed, and the riding comfort can be improved.
[0033]
In particular, the interlocking and non-interlocking of the exhaust brake and the regenerative brake can be selected according to the driver's preference and judgment, such as the driver's preference and judgment. In this case, no sudden change of the brake characteristics occurs, and in this case, the brake characteristics do not suddenly change, so that the brake feeling and the vehicle body posture are not affected.
[0034]
According to the second aspect of the present invention, when the accelerator opening is 0 and the engine speed is equal to or higher than the predetermined idle speed, it is determined that the operating condition of the exhaust brake is satisfied. The state in which the vehicle shifts to the operation of applying the brake from steady running or the like, that is, the state in which the foot is released from the accelerator pedal, can be determined with high accuracy while effectively increasing the cost by preventing the increase in cost.
[0035]
According to the third aspect of the present invention, with a simple configuration, power supply to the throttle valve driven by the electric means is cut off, and the operation of the exhaust brake can be temporarily interrupted.
According to the fourth aspect of the present invention, with a simple configuration, the supply of air to the actuator driven by air is shut off, and the operation of the exhaust brake can be temporarily interrupted.
[Brief description of the drawings]
FIG. 1 is a system diagram showing an embodiment of an energy regenerative braking device according to the present invention. FIG. 2 is a circuit diagram showing an embodiment of a control circuit of the same. FIG. 3 is a flowchart showing control contents of the same. Description】
Reference Signs List 1 engine 1a exhaust passage 5 rear wheel 6 control unit 6A engine control unit 6B regenerative brake control unit 8 pump motor 10 high-pressure accumulator 11 pressurized oil tank 12 exhaust brake 13 throttle valve 15 electromagnetic solenoid 16 accumulated pressure level sensor 17 opening sensor 18 rotation Speed sensor 22 Cut relay 25 Exhaust brake request relay 27 Changeover switch

Claims (4)

An exhaust brake that increases the internal resistance of the engine by a throttle valve interposed in an exhaust passage of the engine to decelerate the engine and, at the time of braking of the vehicle, drives the pump motor by the rotational force of the wheel drive system, and provides a low-pressure oil tank In the energy regenerative braking device that recovers the kinetic energy of the vehicle by pumping the working fluid inside to the high-pressure side accumulator and accumulating the pressure,
Operating condition determining means for determining whether the operating condition of the exhaust brake is satisfied,
Operation interruption means for interrupting the operation of the exhaust brake;
Switching means for switching between interlocking and non-interlocking of the exhaust brake and the regenerative brake;
Accumulation possible determination means for determining whether or not accumulation of the working fluid to the high pressure side accumulator is possible,
The operating condition determining means determines that the operating condition of the exhaust brake has been satisfied, and the pressure storing possibility determining means determines that the pressure can be stored, and the switching means is switched to an interlocking side between the exhaust brake and the regenerative brake. At the same time, the regenerative brake is operated and the operation of the exhaust brake is interrupted by the operation interrupting means, while the operating condition of the exhaust brake is not satisfied, and the switching means switches to the non-interlocking side of the exhaust brake and the regenerative brake. Control means for stopping the operation of the regenerative brake and activating the exhaust brake, at any one of the time when the pressure accumulation is determined to be impossible, and
An energy regenerating brake device for a vehicle, comprising: The operating condition determining means includes an opening degree detecting means for detecting an accelerator opening degree, and a rotational speed detecting means for detecting an engine rotational speed, wherein the accelerator opening degree is 0 and the engine rotational speed 2. The regenerative braking device for a vehicle according to claim 1, wherein it is determined that the operating condition of the exhaust brake is satisfied when is equal to or higher than a predetermined idle rotation speed. When the throttle valve is driven by electric means,
3. The energy regenerative braking device for a vehicle according to claim 1, wherein the operation interrupting unit is a unit that shuts off power supply to the electric unit. 4. In the throttle valve is driven by an actuator using air as a driving source,
3. The energy regenerative braking device for a vehicle according to claim 1, wherein the operation interrupting unit is a unit that shuts off supply of air to the actuator. 4.

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