JPH02117431A - Brake energy recovery and regenerative device for vehicle - Google Patents

Abstract

PURPOSE:To prevent completely a driver from starting a vehicle without returning a parking brake applied when parking by providing a control means which separates an engine and shuts down a hydraulic circuit to keep a nonstarting condition when a parking brake switch shows a stopping condition. CONSTITUTION:After a driver applies a parking brake to stop a vehicle, an engine 1 is separated by a control means 64, and through the output of a parking brake switch, a hydraulic circuit consisting of a high-pressure accumulator 26, a circuit valve 25, a pump motor 14 and a low-pressure accumulator 27 is shut down by the circuit valve 25. This prevents a vehicle from starting regardless of the pedal operation of an accelerator. When a lever knob is depressed to show the intention of a stopping release even if a driver fails to return a parking brake completely, a hydraulic circuit is formed by the circuit valve 25, and with an electromagnetic clutch 13 connected, the pump motor 14 and PTO device 8 are connected to get ready for starting.

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-o)
f) Deceleration energy recovery devices for vehicles equipped with an axle equipped with an output device or a transfer have been known for a long time, and the oldest one was developed in 1976 by the British C.J.
It was announced that Lawrence was developing a bus using British Leyland's buses.Since then, various research and developments have been carried out in Europe and the United States, and recently, JP-A-62
This method is disclosed in Japanese Patent Application Laid-open No. 15128, Japanese Patent Application Laid-Open No. 62-31215, and Japanese Patent Application Laid-Open No. 62-39327.

The latter devices both have a countershaft driven via an engine clutch, a main shaft connected to a wheel drive system, and a transmission engine that has a multi-stage gear train mechanism that changes the speed and transmits the rotation of the countershaft to the main shaft. (hereinafter abbreviated as T/M), a countershaft PTO gear is mounted on the countershaft so that it can cross the countershaft via a countershaft PTO gear synchronizer, and a gear is connected to this PTO gear and connected to the main shaft via a mainshaft PTO gear synchronizer. A multi-stage variable speed PTO device having a main shaft PTO gear mounted so as to be traversable through the main shaft PTO gear, and a PTO output shaft driven via 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 oil tank via this pump/motor, an electromagnetic clutch that enables this hydraulic circuit to cross the PTO axis, and a pump/motor that controls the electromagnetic clutch. Akie emulator connected to the motor and high pressure oil circuit, and pump/
The motor functions as either a pump or a motor depending on the driving condition 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 the Akiemulator 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 heat from the engine, and generates rotational force using the hydraulic oil stored in the Akiemulator during start/acceleration to rotate the wheels via the PTO device. The main part is a control means (which functions as a controller).

The control means of such a deceleration energy recovery device is as follows: - At the time of starting, when the hydraulic pressure in the accumulator is sufficient, the capacity of the variable displacement motor (tilt angle of the swash plate or slant shaft) is adjusted according to the amount of depression of the accelerator pedal. At the same time, the electromagnetic clutch is connected and the hydraulic circuit starts using hydraulic pressure.During this time, when the vehicle speed exceeds the set speed corresponding to the gear selected by the driver, the engine clutch is connected and the engine starts driving. At the same time, the system controls the speed change of the PTO device, turns off the countershaft synchronizer that was on, turns on the main shaft synchronizer, and then applies hydraulic pressure according to the amount of depression of the accelerator pedal only when the amount of depression is large at that time. I do.

■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 part of the 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 "disengaged". It is controlled so that the motor and engine are used together, or when starting/accelerating with the engine alone, it is controlled so that it is "contact".

[Problem to be solved by the invention]

In the case of such conventional technology, when the driver presses the accelerator to start using hydraulic pressure after operating the parking brake and coming to a stop (parking) state, the driver stops the vehicle until the parking brake is released. , if the hydraulic starting force exceeds the parking brake braking force (for example,
If you pull the parking brake lever weakly (or if you hold the vehicle stopped on a downhill slope), you will start off with the parking brake still dragging, wasting hydraulic pressure to overcome the braking force of the parking brake. It turns out.

In addition, in such a case, even if the parking brake is operated and the vehicle is stopped, the starting force generated by the hydraulic pressure exceeds the braking force of the parking brake, so there is a risk that the vehicle will jump out if the accelerator is carelessly pressed. Ta.

Therefore, even if the driver depresses the accelerator when the parking brake is activated, the present invention uses the hydraulic pressure to keep the parking brake applied while driving, thereby preventing the vehicle from wasting the already accumulated hydraulic pressure or causing the vehicle to jump out. The purpose is to realize an energy regeneration device.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a hydraulic circuit;
The parking brake switch includes a parking brake switch and a parking brake switch.

Further, the present invention further includes a parking brake lever knob switch, and when the parking brake switch indicates a stopped state but the knob switch indicates that the stopped state is released, the hydraulic circuit is formed and the hydraulic circuit is activated. An electromagnetic clutch for coupling the hydraulic circuit and the PTO device can be connected to enter the start standby state.

[For production]

The present invention will be explained with reference to the schematic diagram of FIG. 1(a). During operation, the vehicle does not start, which prevents wasteful consumption of hydraulic pressure, and also prevents the vehicle from jumping out.

In the above case, even if you step on the accelerator on a slope, no driving force will be generated unless the parking brake is released, and there is a risk that the vehicle will move backwards due to the time lag between releasing the parking brake and generating starting force using hydraulic pressure. be.

Therefore, in the present invention, a switch provided on the parking brake knob is used to control the circuit valve 25 in order to prepare for starting when the driver indicates the intention to release the stopped state by pressing the lever knob even if the parking brake is not fully returned.
Alternatively, the hydraulic circuit consisting of the high-pressure accumulator 26, the circuit valve 25, the pump motor 14, and the low-pressure accumulator 27 is shut off by the circuit valve 25 or the pump motor 14, depending on the output of the pump motor. As a result, no hydraulic pressure is generated, so the driver steps on the accelerator and PTO: Ii.
! Connect 8 devices.

This makes it possible to immediately start the vehicle using hydraulic pressure when the driver steps on the accelerator.

〔Example〕

Embodiments of the vehicle brake energy regeneration device according to the present invention will be described below.

The first box) is an overall configuration diagram of an embodiment of the brake energy regeneration device for a vehicle according to the present invention, where ■ is an engine, 2 is a load sensor of the engine 1, and 3 is an accelerator pedal 5.
4 is an injection pump lever that is controlled by the step motor 3 and is connected to the load sensor 2, and 5 is an injection pump lever that is controlled by the step motor 3 to set the amount of fuel supplied to the engine 1; and output T/M()transmissigon), 6 is T/M
5, a gear shift actuator that automatically shifts the gear stage (not shown); 7, a clutch actuator that automatically engages the clutch (not shown); 8, a PTO device that engages with the T/M5; 9 is an axle 10 and a wheel 11
A propeller shaft, which together forms the drive system of the wheels, 1
2 is a PTO shaft of PTO device 8, 13 is an electromagnetic clutch, 1
4 is a PTO shaft 1 shaft supported 2 via an electromagnetic clutch 13
Pilot piping 15 for tilting angle control engaged with device 8
, is a well-known variable displacement inclined shaft type axial piston pump motor combined with a tilting angle control electromagnetic proportional valve 16 and a tilting angle control piston 17, and 14a is an inlet port thereof;
14b is a discharge port.

Further, 80 is a tilt angle sensor that detects the tilt angle of the pump motor 14.

Here, regarding this pump motor 14, see FIG. 2(a).
And to explain based on 2nd [F(b) which is a view in the direction of arrow A in FIG. 2(a), as shown in 211D(a), the output shaft 14c is engaged with the center hole of the cylinder block 14r A shaft 14d is inserted into the shaft 14d, and a tilting angle control piston 17 is inserted through the boat shaft 14h on the opposite side.
is engaged with. Further, a plurality of cylinders 14g are provided around the cylinder block 14f, and a piston 14e that engages with the output shaft 14c is slidably inserted into one end of the cylinder 14g, and the opposite side thereof is slidably inserted. communicates with the suction port 14a or the discharge port 14b shown in FIG. 2(b) via the boat plate 14h.

The above-mentioned tilt angle control piston 17 is connected to a hydraulic oil or hydraulic pipe 20 that is supplied to the lower part of the piston 17 from the tilt angle control pilot pipe 15 in proportion to the control current supplied to the tilt angle control electromagnetic proportional valve 16. Or, by being pushed by the hydraulic oil in 21, its position changes in the vertical direction in the figure. Therefore,
Cylinder block 14f1 Piston 14e1 Shaft 1
4d and the boat plate 14h, the angle changes as the tilting angle control piston 17 moves up and down around the spherical end of the shirt 14d engaged with the output shaft 14c (in this case, the angle changes between the output shaft 14C and the shaft). 14d
The angle θ formed by these is called the tilt angle).

FIG. 2(a) shows the case when the maximum control current is applied to the tilting angle control electromagnetic proportional valve 16, and since the tilting angle is the maximum, the discharge amount per revolution of the output shaft 14c is the maximum. It has become. (11) When the control current of the angle control electromagnetic proportional valve 16 is O, the tilt angle is O and the discharge amount is also O, as shown by the dotted line.
becomes.

Returning to FIG. 1, etc., 18 is a high-pressure relief valve that releases the accumulated pressure in a high-pressure accumulator 26, which will be described later, when it exceeds a set value, and 19a is a high-pressure relief valve that releases pressure when the supply pressure of hydraulic oil in the replenishment circuit exceeds the set value. 19b is a low pressure relief valve that generates the pilot pressure necessary to operate the pump/motor 14 in tilting operation in the pilot piping 15 for controlling the tilting angle; 20 is the suction side of the pump/motor 14; Piping, 21 is the discharge side piping of the pump/motor 14, 22 is the hydraulic oil supply piping, 22a is the hydraulic oil return piping, 23 is the high pressure side piping, 24 is the low pressure side piping, 25 is the above piping 20 to
24 is a circuit switching valve for switching the circuit switching valve 24; 26 is a high-pressure Achiemulator connected to the circuit switching valve 25 via the high-pressure side piping 23; 27 is connected to the circuit switching valve 25 via the low-pressure side piping 24 for the pump/motor 14; This is a low pressure accumulator that forms a hydraulic circuit together with the circuit switching valve 25 and the high pressure accumulator 26.

Note that the circuit switching valve 25 is necessary to switch the output between the pump and the motor when the pump/motor 14 is used with a fixed outlet. If a motor is used, a circuit isolation valve can also be used. These circuit switching valves and circuit cutoff valves can be collectively referred to as circuit valves.

Here, to explain the piping switching operation by the circuit switching valve 25, when neither of the electromagnets 25a and 25b is energized, the valve position is the position shown in the center of the three valve positions, and the four valve positions are Pipes 20, 21, 23 and 24 are disconnected.

When recovering brake energy, the electromagnet 25a
is energized to switch the valve position to the electromagnet 25a side. Then, the low pressure accumulator 27 can be communicated with the suction port 14a of the pump motor 14 via the pipes 24 and 20, and the high pressure accumulator 26 can be communicated with the discharge port 14b of the pump motor 14 via the pipes 23 and 21. . As a result, the hydraulic fluid stored in the low-pressure accumulator 27 is sucked/discharged by the pump/motor 14 that is driven by brake energy and functions as a pump, and the pressure is accumulated in the high-pressure accumulator 26 .

On the other hand, when the pump motor 14 is to function as a motor, the electromagnet 25b of the circuit switching valve 25 is energized and the valve position is switched to the electromagnet 25b side.

Then, the low pressure accumulator 27 can be communicated with the discharge port 14b of the pump motor 14 via the pipes 24 and 21, and the high pressure accumulator 26 can be communicated with the suction port 14a of the pump motor 14 via the pipes 23 and 20. As a result, the hydraulic oil accumulated in the high-pressure accumulator 26 passes through the pipes 23 and 20 to the pump motor 1.
4 as a motor, it passes through the pipes 21 and 24 and reaches the low pressure accumulator 27, where it is stored.

28 is a drain tank for hydraulic oil, 29 is a filter for hydraulic oil, 30 is a replenishment pump for hydraulic oil driven by the engine 1, and 31 and 32 are provided on the replenishment pipe 22 and are operated to return from the hydraulic circuit to the drain tank. This is a solenoid valve that supplies oil to the hydraulic circuit and also supplies pilot hydraulic pressure to the pump/motor 14 via a tilt angle control pilot pipe 15.

Next, 33 is a direct connection cooling relay switch, 34 is a water temperature sensor for engine 1, 35 is a rotation speed sensor for engine 1, 3
6 is the implant shaft rotation speed sensor, 37 is 77M5
38 is a clutch stroke sensor, 38 is a gear position sensor,
39 is a gear shift stroke sensor, 40 is a vehicle speed sensor, 41 is a 77M5 oil temperature sensor, 42 is an exhaust brake control valve, 43 is a cylinder that drives an exhaust brake valve (not shown), and 44 is a cylinder that drives an exhaust brake control valve (not shown). 45 and 46 are oil amount detection limit switches provided in the drain tank 28, and 47 is a pressure sensor that detects the pressure of the hydraulic oil accumulated in the high pressure accumulator 26. Note that the gear position sensor 38 and the gear shift stroke sensor 39 constitute gear position detection means.

48 is a hand lever that operates the exhaust brake, 49 is a driver seat, 50 is an vacated seat detection switch that detects whether or not the driver has left the driver seat 49, 51 is a parking brake lever, and 52 is a parking brake inch. , 53 is a brake energy regeneration system (hereinafter referred to as RBS) main swing, 54
is the accelerator pedal, 55 is the idle position detection switch,
56 is an accelerator opening detection sensor, 57 is a brake pedal, and 58 is a brake pedal return position detection switch (hereinafter referred to as
59 is a brake pedal amount sensor, 60 is a gear select lever, 61 is a slope start assist device (hereinafter simply referred to as H3A) switch,
62 is an idle control switch, 63 is an indicator, 65 is a door switch, 66 is a key switch, 6
7 is brake air piping, 68 is brake air tank, 6
9 is a brake air pressure sensor, 70 is an electromagnetic proportional pressure control valve, 71 and 73 are air pressure switches, 72 is H3A
74 is an air mask; 64 is a control unit (hereinafter abbreviated as C/U) as a control means for controlling the pump/motor 14 and actuator to regenerate brake energy based on the outputs of the above-mentioned sensors and switches, etc. Note that the C/U 64 includes a memory (not shown) for storing programs, maps, and flags described below.

FIG. 3 is a flowchart of a program stored and executed by the C/U 64 shown in FIG. 1, and the operation of the embodiment shown in FIG. 1 will be explained based on this flowchart.

When the program starts, the C/U64 executes an initialization subroutine, turns off all outputs, and uses the built-in RAM (
Clear check (not shown) (Step S in Figure 3)
l).

After performing the initialization, switch 33.45.46 mentioned above
．． 50.52.53.55.58.61.62.65.
A subroutine for reading signals from sensors 66, 71 and 73 and the sensor 38 is executed (step S2), and then a subroutine for processing rotational signals (pulses) read from sensors 35, 36 and 40 is executed to determine the engine rotational speed, respectively. Calculate input shaft rotation speed and vehicle speed (
same step S3).

And sensor 2.34.37.39.41.47.5
Execute the analog signal processing subroutine read from 6.59.69 to obtain the digital values of engine load, clutch stroke, shift stroke, oil temperature, pressure, accelerator opening, brake depression amount, and brake air pressure. Step S4).

Reading and processing of these signals are updated every time C/U processing is performed. In addition, flags (described later) used during rosin calculation according to the read signals and processed signals are set in these subroutines (excluding flags for seven stitches/recent in the control 11H layer).

Next, it is checked whether the key switch 66 is on or not (step S5), and if it is off, a subroutine for stopping all controls is executed (step S6).

In this subroutine, in order to ensure safety even if the key switch 66 is turned off when stopping or driving, the entire hydraulic system is returned to a safe state, and then, in step S7, the actuator relay (not shown) is turned off and the All control is stopped by cutting off the power to /U64.

When the key switch 66 is on in step S5,
Check whether the RBS main switch 53 is on or not (step S8 in FIG. 3). If it is off, execute the normal brake control mode subroutine (step S8 in the same figure), which will be described later.
22) is on, it is assumed that the driver is attempting to perform a brake energy regeneration system (hereinafter referred to as RBS) operation, and control continues.

Therefore, the C/U 64 checks whether or not the driver is operating the parking brake 51 (step S9), and when the driver is not operating the parking brake 51 (when the parking brake switch 52a (P/Bl) is off). ), the process proceeds to step S11 as RBS usable, but when it is activated (
When the parking brake switch 52a is on), the mode advances to the normal brake control mode (step 522) and the R
The use of BS is prohibited. This may occur when the accelerator pedal 51 is inadvertently pressed while the parking brake lever 51 is being pulled.
This is to prevent the vehicle from flying out even if you step on it.

However, another parking brake switch 52 is provided in case the output torque of the pump/motor 14 is transmitted to the wheels 11 while the parking brake is activated, such as when starting on a slope.
It is preferable to check whether or not b is on (step 510).

Here, the parking brake switch 52b (P/B2
) is turned on only when the knob 51a of the parking brake lever 51 is pressed, as shown in FIG. That is, since the state in which the knob 51a is pressed indicates the intention to release the parking brake, the RBS can be used even if the parking brake lever 51 is pulled and the parking brake switch 52a is on. It is.

Next, the C/U 64 checks the selected gear using the gear position detection sensor 38 and the gear shift stroke sensor 39 (step 511), and if the gear is set to N (Etral) or R (Reverse), the RBS is The routine proceeds to the normal brake control mode subroutine (step 522) without using it, but if the gear is 1st to 5th, RB
Since S is available, control continues.

Then, it is checked from the output of the vehicle speed sensor 40 whether the vehicle is stopped or not (step 312), and if the vehicle is traveling, the process proceeds to step S14 and the current speed of the pump motor 1 is checked.
Check whether it corresponds to the allowable rotation speed of 4 or less. This allowable rotational speed is determined by the pump motor 14 and the electromagnetic clutch 1
3, PTO shaft 12, PTO device 8, propeller shaft 9
Since it is connected to the wheels 11 via the axle lO, if the gear ratio of the PTO device 8 and the axle 10 is constant, it can be determined by the vehicle speed, and the gear ratio can be determined from the allowable rotation speed of the commercially available pump/motor 14. By multiplying the outer circumferential lengths of the wheels, it can be determined that the usable range of the RBS is, for example, up to 50 km/h.

In step 314, if the vehicle speed is 50 km/h or less, that is, within the permissible rotation speed range of the pump motor 14,
The control is continued, but if it is determined that the number of revolutions exceeds the allowable rotation speed range, the normal brake control mode subroutine of step 322 is executed.

In step 512, when the vehicle is stopped and the vehicle is a bus, a start prohibition subroutine is executed (step 513). This subroutine prohibits the use of the hydraulic circuit when the bus has its doors open. When the door is open, it is assumed that a passenger is getting on or off the vehicle, and this is done to ensure the safety of the passenger so that the vehicle does not start moving even if the accelerator is inadvertently pressed.

Next, the C/U 64 checks the driver's pedal operations in the order of brake (step 515), accelerator (step 516) (each signal processing has already been processed in the analog signal processing subroutine of step S4), brake The reason why the operation check is given priority over the accelerator operation check is that when the brake pedal 57 and the accelerator pedal 54 are depressed at the same time, priority is given to the brake for vehicle safety.

If the brake pedal 57 is depressed in step 515, an energy recovery mode subroutine is executed (step 517). When the brakes are often used at low speeds, such as during traffic jams, the hydraulic system is controlled more frequently, so in order to avoid using hydraulic pressure, the system responds to the amount of depression of the brake pedal 57 only when the vehicle speed is above a certain level. The required brake torque is determined by To find the brake torque in this case, a control torque search is performed using the brake torque map shown in FIG. 7, and the braking torque that the driver is trying to generate is searched and stored based on the amount (angle) of depression of the brake pedal 57.

Here, to explain the brake torque map shown in FIG. 7, this map is the sum of the amount of depression of the brake pedal 57 of an air brake, air over hydraulic (air-oil) brake, etc. and the braking torque per vehicle. This is based on a diagram showing the relationship between the front and rear wheels.
The pedal operation in BS and the actual brake effectiveness are equivalent to the operation of air brakes, air/oil brakes, etc.

In FIG. 7, the initial state of the brake pedal 57 (
For example, if the brake play exceeds the initial state B (for example, 3.5 degrees), the switch 58 is turned on and the sensor 59 outputs a voltage proportional to the pedal depression angle. Therefore, the depression angle of the brake pedal 57 can be detected from the output of the sensor 59, and the pump/motor 14, air brake, or air/oil brake is controlled in this section. For this reason, the brake pedal 5 is
The braking torque T corresponding to the depression angle of 7 is determined.

Area beyond the brake force control area (for example, 16° to 2°
5°) is during panic braking, and at this time, the electromagnetic proportional air pressure control well 70 is forcibly pushed down by a link mechanism (not shown) communicating with the brake pedal 57.
The brake air tank 68 and a brake force generating device, for example, an air master 74 in an air-oil type, are fully connected to generate maximum braking force using compressed air. At this time, the vehicle may become unstable, so
The use of hydraulic circuits is prohibited.

After executing the energy recovery mode subroutine in this manner, C1064 executes the engine brake mode subroutine (step 518 in FIG. 3). This subroutine is intended to eliminate the difference in feeling from a normal vehicle, that is, to generate a braking force equivalent to exhaust braking or engine braking.

The exhaust brake is an auxiliary brake that is operated by the hand lever 48 (or switch) on the driver's seat without stepping on the brake pedal 57, and the engine brake generates braking force as a load when the vehicle drives the engine. This is an auxiliary brake.

To the subroutine of step 318, the brake pedal 5
If the accelerator pedal 54 is not depressed (when the accelerator pedal is in the A/F dollar position), the process proceeds from the subroutine of step S17 to step S16.
However, since the engine brake mode subroutine (step 818 in FIG. 3) is a substitute mode for the auxiliary brake generated by the engine, it has no relation to the brake pedal operation in step S17 in FIG. 3.

That is, both the exhaust brake and the engine brake are applied to the hand lever 48 unless the accelerator pedal 54 is depressed.
An alternative force is generated under the control of the output of In other words, when determining the braking force corresponding to the amount of depression of the brake pedal, if the vehicle is traveling at a certain speed or higher, a braking torque equivalent to the exhaust brake or engine brake is also determined.

Next, the C/U 64 performs a pump calculation to determine the capacity of the pump motor 14 required to generate the necessary control torque retrieved and stored in the subroutines of steps S17 and 318, according to the pressure in the hydraulic circuit. A subroutine is executed (step 519 in FIG. 3).

That is, the above-mentioned step SI? And, if hydraulic brake control using the pump/motor 14 is performed in step S18, all the controls that need to be generated by the pump/motor 14 are calculated by integrating the necessary braking torque for each brake mode searched in steps 517 and 318. Calculate torque.

Then, the capacity IVP of the pump motor 14 is determined from the torque value T at the pump motor 14 obtained by dividing the required torque value by the gear ratio of the final gear and the PTO device using the following theoretical formula (1).

V, =200 ET/P (1) Here, P: Pressure in the hydraulic circuit detected by the pressure sensor 47 (kg
/am''), ■P: Capacity of pump/motor 14 (CC), T: Required control torque (kg-m).

In the present invention, as shown in FIG.
A pump motor 14 can be used, so that its volume 1vp is controlled by controlling the tilt angle of the slant shaft (or swash plate).

Returning to step 316 of the main program, when the accelerator pedal 54 is depressed, the C/U 64 executes an energy recovery mode subroutine (step 520 of FIG. 3), which recovers energy and restores the high pressure accumulator. As shown in FIG. 8, this routine calculates and stores the required torque according to the amount of depression of the accelerator pedal at that time.

The main program then executes the normal brake control mode subroutine in step S22, which is a mode in which the brakes are applied only by air brakes or air-oil brakes without using hydraulic pressure.

To explain this subroutine as shown in Figure 5, first,
The amount of depression of the brake pedal 57 and the discharge pressure of the electromagnetic proportional air pressure control valve 70 are searched using the map in FIG. 7 (step S221 in FIG. 5). This means that the braking torque is, for example, in the case of an air oil brake. This search is performed because it is determined by the discharge pressure sent to the air master 74, and this map is
In order to match the braking feeling, the discharge pressure line is the same as that of a normal air brake vehicle (or air/oil brake vehicle). Note that step S8.5IO1 in FIG.
When proceeding to this subroutine from Sll and 314, the amount of depression of the brake pedal 57 is also given and the braking torque is determined.

Next, based on the discharge pressure retrieved in step 5221,
i Drive the magnetic proportional air pressure control valve 70 in step 32.
22) Since this subroutine uses only air, the tilt angle of the pump motor 14 is set to 0° in order to turn off the hydraulic system.
', the same step 5223), the circuit switching valve 25 and/or
Or turn off the electromagnetic clutch 13 (step 322
4) Return to the main program.

In this normal brake control mode, as mentioned above, when the parking brake is pulled, the brake pedal is normally not depressed, so the electromagnetic proportional air pressure control valve 7
0 is not driven, and only opens the hydraulic circuit and disengages the electromagnetic clutch 13. Therefore,
Thereafter, by pressing the parking brake knob 51a and depressing the accelerator with the parking brake 51 released, a hydraulic start is performed by the energy regeneration mode subroutine S20.

After the above control, the C/U 64 performs oil amount control (
Step 321 in FIG. 3). In this oil amount control, it is determined whether or not oil needs to be replenished based on whether the oil amount detection limit switch 45 is on or off, and the solenoid valves 31 and 32 are used to constantly maintain an appropriate amount of oil in the hydraulic system. is supplied to.

The C/U 64 also receives a vehicle speed signal from a vehicle speed sensor 40, a signal corresponding to the amount of depression of the accelerator pedal 54 from an accelerator opening detection sensor 56, and a gear select lever, as in the well-known Japanese Patent Application Laid-Open No. 60-11769. The select signal (matrix signal) from 60 is read, and the appropriate gear stage of 77M5 is selected based on the map shown in FIG. 9 created according to the vehicle speed and the amount of depression of the accelerator pedal 54 (
Steps S23 and 524 in FIG. 3).

This operation is performed by driving the clutch actuator 7 and gear shift actuator 6, disengaging the engine clutch (not shown) → setting the T/M5 gear to neutral → selecting and shifting → connecting the engine clutch. As a result, the gear of the 77M5 is automatically shifted up/down to an appropriate gear according to the vehicle speed and the amount of depression of the accelerator pedal 54.

Note that the C/U 64 is based on the clutch control method determination subroutine shown in FIG. 5241), the engine clutch is disengaged (step 5242), and this flag FL
Bit 3 of the RBS is always set when the C/U 64 is in the energy recovery mode, and is set when the vehicle is driven only by oil pressure in the energy regeneration mode.

Furthermore, automatic clutch-type automatic transmission vehicles are already known for engine clutch engagement/disengagement control.
Furthermore, even if the vehicle does not have an automatic transmission, only the engine clutch needs to be able to automatically engage/disengage.Furthermore, in the case of vehicles with a hydraulic automatic transmission, disconnection from the engine can be achieved by controlling the gear to the neutral position. A similar effect can be obtained.

Next, the capacity of the pump/motor 14, the disconnection/connection of the electromagnetic clutch 13, and the circuit switching valve 2 determined in the above-mentioned energy recovery mode, regeneration mode, normal brake control mode, etc.
5, the hydraulic circuit control subroutine for actually driving these is executed (step 325 in FIG. 3).
).

This subroutine controls the circuit switching valve 25 and pump/motor 14 that constitute the hydraulic circuit based on the above various judgment results.
It also actually controls the electromagnetic clutch 13.

After performing hydraulic circuit control (step 525), signals from the direct cooling relay switch 33 and water temperature sensor 34 are read, and in addition to stabilizing the idle rotation during warm-up and cooling of the engine 1, the replenishment pump 30 An idle control subroutine is executed to stabilize the idle rotation when driving the engine (step 326).

Thereafter, the target position of the step motor 3 is set using the output torque of the engine 1 determined in the above-mentioned energy regeneration mode, etc., and an engine control subroutine for driving the step motor 3 is executed (step 527). Pump motor 14 determined by regeneration mode etc.
When the capacity V is V<250cc, it is idling,
When V>250cc, the engine is controlled so that the required engine output obtained from the following equation (2) is generated.

Required engine output = ((T/M required output) - (maximum pump/motor output) x (PTO gear ratio)] / (T/M gear ratio) (2) As mentioned above, this engine output is determined by the amount of accelerator pedal depression. It is obtained by converting the fuel injection governor into a step motor and driving the fuel injection governor.

After the above control and processing, oil pressure and power 1flQ (hydraulic,
The indicator control subroutine for controlling the display of the indicators 63 including the engine) display is executed (step 328).

Then, provided that the vehicle speed is 0 and the brake pedal 57 is depressed, the ISAS child valve is closed to maintain the brake state, and the accelerator pedal 54 is depressed or the gear select lever 60 is moved to the neutral position. As a result, the H3A control subroutine for releasing the brake state is executed (step 529).

After this, check whether it is time to execute the self-diagnosis (step 530), and when the time comes, execute the self-diagnosis periodically (for example, every 500 m5) (step 53).
1) After waiting for a period of time to make the processing time constant (step 532), the process returns to step S2 and repeats the above-described process.

Incidentally, the above-mentioned subroutine (steps 323 to 31) can use currently known techniques.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to prevent the vehicle from running with the parking brake being dragged by hydraulic pressure until the parking brake is fully returned, consuming unnecessary hydraulic pressure, or causing the vehicle to fly out.

In addition, when the parking brake lever knob switch is used to detect that the stopped state is in the process of being released, by forming a hydraulic circuit and connecting the electromagnetic clutch, it is possible to provide a start standby state at the stage when the lever knob is pressed. It is possible to use hydraulic pressure without waste and to start without backing up on a slope or the like.

[Brief explanation of drawings]

FIG. 1(a) is a conceptual diagram of a brake energy regeneration device for a vehicle according to the present invention, FIG. Figure 2(a),
(C) is a sectional view and a perspective view, respectively, of the oblique shaft type axial piston pump/motor used in the present invention; FIG. 3 is a flowchart of a program stored and executed by the control means of the present invention; 5 is a schematic diagram for explaining the parking brake lever; FIG. 5 is a flowchart of the Nakadera normal brake control mode subroutine; FIG. 6 is a flowchart of the subroutine for determining the engine clutch control method; FIG. 7 is a brake torque map diagram, FIG. 8 is a torque map diagram for each gear stage, and FIG. 9 is a gear shift map diagram based on vehicle speed and accelerator pedal depression amount. In the figure, 8 is a PTO device, 13 is a 'g1 magnetic clutch, 14 is a pump motor, 25 is a circuit switching valve, 26 is a high pressure accumulator, 27 is a low pressure accumulator, 51 is a parking brake lever, 52a is a parking brake switch, 52b indicates a parking brake knob switch, and 64 indicates a C/U as a control means. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) When the hydraulic circuit, the parking brake switch, and the parking brake switch indicate a stopped state,
A brake energy regeneration device for a vehicle, comprising: control means for disconnecting the engine and interrupting the hydraulic circuit to maintain a non-starting state. (2) further comprising a parking brake lever knob switch, which forms the hydraulic circuit when the parking brake switch indicates the stopped state but the knob switch indicates the direction of canceling the stopped state; 2. The braking energy regeneration system for a vehicle according to claim 1, wherein an electromagnetic clutch for coupling the PTO device and the PTO device is connected to be in a start standby state.