JP3481281B2 - Vehicle equipped with braking energy regeneration device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to energy transmission of hydraulic oil.
Start / acceleration energy of vehicle braking energy as a medium
Equipped with accumulator-type braking energy regenerating device used for vehicle
About. [0002] 2. Description of the Related Art Conventionally, energy during braking has been recovered and
A braking energy regenerating device that uses this when starting and accelerating
A vehicle such as a city bus provided is, for example, Japanese Patent Publication No. 5-1168.
It is known from U.S. Pat. This braking energy regeneration device
For vehicles equipped with
Operating as the low pressure tank hydraulic oil in the accumulator
To store the braking energy
You. When the vehicle starts or accelerates (these
Is also simply referred to as start / acceleration).
Pump / motor by supplying high-pressure hydraulic oil to pump / motor
As a motor to drive the drive wheels of the vehicle
The braking energy is reused.
You. [0003] Such a braking energy regenerating device is provided.
During braking to recover braking energy
Work by pump operation of energy regeneration device is auxiliary brake
To generate braking force,
Check that the pump is started by stepping on the dull
And brake switching control to use this braking force.
The braking force of the normal service brake is weaker
I am trying to. [0004] By the way, as in the prior art,
In simple brake switching control, pump operation starts and
When it is confirmed that a braking force has been generated by the pump operation,
Switching provided in the middle of the normal service brake air path
By switching the valve to another path through the pressure reducing valve
The service braking ratio was reduced. I
However, even if switching to the path through the pressure reducing valve,
If the pressure reducing valve does not operate normally and air conduction is difficult
When the state is reached, the braking force by the service brake
Can not be exhibited as expected, almost due to pump operation
In some cases, only the braking force of the auxiliary brake
Was. Also, if you depress the brake pedal strongly,
During emergency braking, reduce the air pressure with the pressure reducing valve
Therefore, there is a possibility that the braking intended by the driver cannot be performed. [0005] Therefore, the present invention provides a method for reducing the pressure of the pressure reducing valve and the emergency
The brake pedal is strongly operated by the rake
When braking, do not weaken the braking force of the service brake,
Regeneration of braking energy to obtain sufficient braking force
It is an object to provide a vehicle equipped with the device. [0006] In order to achieve the above object,
Therefore, the vehicle provided with the braking energy regenerating device of the present invention
A low-pressure tank for storing hydraulic oil and an
The drive system of the vehicle is installed in the oil passage between the
Pump / motor connected to the material via a clutch
Pump during braking, and the braking energy is
While converting it to lugi and accumulating it in the accumulator,
During forward / acceleration, the motor is operated and stored in the accumulator.
Use the accumulated hydraulic energy as start / acceleration energy
In vehicles equipped with a braking energy regeneration device,
Braking pressure generation that generates braking pressure according to the operation amount of the key pedal
Generating means, and the braking pressure connected to the braking pressure generating means.
A pressure reducing valve that outputs a pressure reduced by a predetermined ratio,
The pressure from the braking pressure generator is supplied directly to the wheel braking device
The first state and the pressure from the pressure reducing valve to the wheel braking device.
A switching valve capable of switching between a second state to be supplied to the
Braking pressure for detecting the braking pressure generated by the braking pressure generating means
Detecting means for controlling the hydraulic pump / motor during braking of the vehicle.
Pump operationThe switching valve is in the second state.
IThe amount of change in the braking pressure detected by the braking pressure detecting means is small.
When the threshold value is exceeded, the switching valve is switched to the first state.
Control means for inhibiting reduction of the braking pressure by the pressure reducing valve
And characterized in that: [0007] [Function] During braking, a braking force is generated by the operation of the pump.
The braking pressure detected by the braking pressure detecting meansThreshold of change
Greater than or equal toSometimes the driver wants a strong braking force
In such a case, the switching valve is switched to the first state.
Prohibit the pressure reduction of the braking pressure by the pressure reducing valve.
Sufficient control of the rake braking force and the pump operating braking force
Get power. [0008] An embodiment of the present invention will be described with reference to the drawings.
You. Vehicle provided with energy regeneration device shown in FIGS. 1 to 4
Are the drive wheels via the transmission 3 and the clutch 2
1 for driving the motor and a brake for braking
Equipped with a power unit 70, the energy
The lug regeneration device has a piston type accumulator 20,
Pressure hydraulic oil tank 30, swash plate type variable displacement piston type pump
/ Motor 40, gear box 50, control unit
And the like (hereinafter referred to as ECU). First, a vehicle equipped with an energy regeneration device
Explaining from the configuration of FIG.
The output shaft is connected to the transmission 3 via the clutch 2.
The output shaft 13 of the transmission 3 is
Connected to the differential (through shaft type) of the driving shaft 10
I have. Then, the energy regenerating device is driven through the drive shaft 12.
Connected to the aforementioned differential device. Also, with the braking system
As a result, the brake power unit 70
And to provide a braking force to the driven wheel WF.
You. Turning to the configuration of the energy regenerating device, first,
The swash plate type can be used for the accumulator 20 via the high-pressure oil pipeline P1.
First port 40 of variable displacement piston pump / motor 40
a, the second port of the pump / motor 40
40b is connected to the hydraulic oil tank 30 via the low-pressure oil pipeline P2.
It is connected. The accumulator 20 includes a piston 21
Is divided into a gas chamber 22 and a hydraulic oil chamber 23 by the gas chamber 2.
2 is filled with a predetermined pressure of nitrogen gas,
The hydraulic pressure can be accumulated. An accumulator 20 is connected to the high-pressure oil pipeline P1.
Shutoff valve 24 and unload valve (normal
(Open) 25 is provided. The shut-off valve 24 is an electromagnetic
It is an pilot operated valve, usually from the pump / motor 40
Allow the flow of hydraulic oil toward the accumulator 20,
Functions as a check valve that blocks the flow in
When the shut-off valve signal D2 is input from the
Flow of hydraulic oil from the pump 20 to the pump / motor 40
Allow. The electromagnetic unload valve 25 is connected to the ECU 60
Activated by the unload valve signal D3,
P1 and the low-pressure oil line P2 are short-circuited via line P4,
The residual pressure trapped in the oil line P1 is released to the low-pressure oil line P2.
It can be removed. [0012] Between the high-pressure oil pipeline P1 and the low-pressure oil pipeline P2,
A check valve 46 is provided, and the check valve 46 is connected to the low-pressure oil pipe P.
2 to the high-pressure oil pipeline P1
Caused by running out of hydraulic oil in the high pressure oil line P1.
To prevent equipment damage. Furthermore, from the shutoff valve 24
A pipe branched from the high-pressure oil pipeline P1 on the pump / motor 40 side
The line P3 is connected to the hydraulic oil tank 30, and this line P3
Means that the discharge pressure of the pump / motor 40 is equal to the set pressure (for example, 3
50kgf / cm^Two), The high pressure oil
The relief valve 26 for releasing to the work 30 is provided.
You. The high pressure oil pipeline P1 is
Pressure sensor for knowing the pressure inside the pipe on the side of the pump / motor 40
89 is provided to supply the discharge pressure signal PHY to the ECU
are doing. The accumulator 20 contains
Therefore, the piston 21 slightly moves to the maximum expansion position of the hydraulic oil chamber 23.
If you move to a predetermined position before the crab (called the immediately preceding position)
When this is detected, the piston position signal (off signal) LP
Position sensor 87 that outputs the pressure in the hydraulic oil chamber 23
Accumulated pressure detection that detects the operating hydraulic pressure of the motor and outputs a pressure accumulation signal PAC
A pressure accumulation sensor 88 is provided as an output means.
Each of the piston position signal LP and the pressure accumulation signal PAC is transmitted to the ECU 60.
To supply. The pump / motor 40 includes a gear box 50
The drive shaft 12 is connected to the drive shaft 12
The braking energy of the drive shaft 10 and the gearbox 50
Is transmitted to the pump / motor 40 via the
The starting / acceleration energy of the motor 40 is
From the drive shaft 12 via the differential shaft to the drive shaft 10.
It is. The gear box 50 includes a pair of gears 50a and a dog gear.
And a pair of gears 50a.
The rotation of the rotation of the motor 12 is increased and transmitted to the pump / motor 40.
The connection between the drive shaft 12 and the pump / motor 40 is a dog clutch.
It is connected and disconnected by the hook 51. The pump / motor 40 includes a gear box 50
Drive shaft 40e connected to the output shaft of
Piston 40f to be fitted and fitted to the cylinder 40f
With the rotation of the mounted piston 40c and the drive shaft 40e
And a swash plate 40d for reciprocating the piston 40c.
And the angle of the swash plate 40d with respect to the drive shaft 40e, that is, the inclination.
By controlling the turning angle, its pump / motor capacity
Is set. The tilt angle of the swash plate 40d is
Is variably controlled. This tilt cylinder 41 is inclined
A piston 41a connected to the plate 40d;
Chambers 41b and 41 respectively formed on both sides of 1a
c in one chamber, for example, chamber 41b.
The pilot hydraulic pressure from the pilot hydraulic power source 43 described
When supplied, the swash plate 40d is driven to the pump operation side,
When the pilot oil pressure is supplied to the chamber 41c,
It is designed to be driven to the operation side. The pilot hydraulic power source 43 is connected to an electric motor or the like.
It is composed of an oil pump and pressure regulating valve driven by
Generates constant pilot pressure. This hydraulic power source 43
A filter 45 and an electromagnetic two-position
The port switching valve 44 and the proportional solenoid valve 42 are arranged in this order,
These are transmitted from the pilot hydraulic pressure source 43 to the tilt cylinder 41
To control the supply pressure of pilot hydraulic pressure to
And a hydraulic control circuit. The switching valve 44 is connected to the ECU
60, the pilot signal P5
Communication and shut off. One solenoid of the proportional solenoid valve 42, for example,
When the control signal ELP is supplied to the solenoid 42a, the signal
Pilot oil pressure of magnitude corresponding to value ELP is proportional solenoid valve
Via the pump operating side of the tilt cylinder 41
To the other solenoid 42b.
When the control signal ELM is supplied, a large value corresponding to the signal value ELM is obtained.
The pilot hydraulic pressure is as large as the chamber 41c on the motor operation side.
And the piston of the tilt cylinder 41
The operating position of 41a and the tilt angle of swash plate 40d are variable
When the pump is running,
When the motor is running, adjust the output torque.
It is supposed to. When the pump / motor 40 is operating,
The swash plate 40d is moved to the pump operation side by the tilt cylinder 41.
When the hydraulic oil is driven, the hydraulic oil
8, check valve 58, pipe P2, pump / motor 40, pipe
Flows through P1 to accumulator 20, when motor is running
, The swash plate 40d is driven to the motor operation side, and the hydraulic oil is
In the opposite direction to the operation of the pump,
Line P1, pump / motor 40, line P2, check valve 57,
It flows to the hydraulic oil tank 30 via the filter 37. The hydraulic oil tank 30 is a two-port electromagnetic type.
Pressurizing via the exchange valve 33, the pressure reducing valve 35, and the air dryer 36
The air tank 31 is provided with an electromagnetic three-port switching valve 34.
Are connected to the sub air tank 32 through
Constitutes an air pressure supply circuit to the hydraulic oil tank 30
I have. The switching valve 34 is connected to the ECU 60 as valve control means.
The sub air tank 32 is activated by the drive signal D7.
And the hydraulic oil tank 30 to the communication position.
You. The sub air tank 32 and the hydraulic oil tank 30 communicate with each other.
As a result, the sub air tank 32 is partially
The supplied air is supplied to the hydraulic oil tank 30 and the hydraulic oil
Supply air in accordance with fluctuations in the amount of hydraulic oil in tank 30
Or by absorbing to stabilize the air pressure in the hydraulic oil tank 30
Aim. On the other hand, the drive signal D7 from the ECU 60 is cut off.
And the switching valve 34 is switched to the atmosphere release position,
The pressure in the tank 30 is released to the atmosphere. The switching valve 33 receives a drive signal from the ECU 60.
Activated by D6 to create high pressure air in the air tank 31.
The hydraulic oil is supplied into the hydraulic oil tank 30 and the hydraulic oil in the tank 30 is
Operation of the pump / motor 40 by increasing the pressure to a constant pressure
Keep it stable. Pump / motor 40 and hydraulic path
Hydraulic oil leaking from the inner fitting part (oil seal) etc.
Reflux to the tank 39. The drain tank 39 is a pump
59, a filter 97 and an electromagnetic two-port switching valve 98
Is connected to the hydraulic oil tank 30 through the
When the hydraulic oil in the pump 39 reaches a predetermined amount, the pump 59 is started.
The ECU 60 outputs a drive signal to the switching valve 98
Then, the hydraulic oil tank 3
Refill to zero. The hydraulic oil tank 30 has a hydraulic oil level sensor.
A sensor 90 and an oil temperature sensor 91 are provided.
The oil level signal LOIL and the oil temperature signal TOIL are sent to the ECU 60.
Supplying. The ECU 60 uses these signals to
It monitors whether the hydraulic oil is in a normal state and
The operation of the pump / motor 40 etc.
To prevent damage. The dog clutch 51 is operated by air pressure.
The dog clutch 51 is connected to the clutch
3-port switching valve 53 for clutch and clutch disconnection
The air tank 52 is connected via an electromagnetic three-port switching valve 54.
These make up the dog clutch actuation control circuit.
Has formed. The switching valve 53 for clutch connection is provided by the ECU 6
When activated by the drive signal D8 from 0, the air tank 5
2 is supplied to the dog clutch 51 and the dog clutch 51
The latch 51 is engaged, while the clutch 51 is disengaged.
The switching valve 54 is activated by the drive signal D9 from the ECU 60.
When the dog clutch 51 moves, the dog clutch 51 performs a disconnection operation. The dog clutch 51 has a dog clutch connection / disconnection.
A sensor 92 is provided to disconnect and connect the dog clutch 51.
The state is detected, and the detection signal DCL is supplied to the ECU 60.
Have paid. Also, the pump / motor of the dog clutch 51
On the side output shaft, the rotation speed of the pump / motor 40 is detected.
A rotation speed sensor 93 is provided, and a pump rotation speed signal is provided.
NP is supplied to the ECU 60. Here, the energy of the vehicle configuration
The components related to the regenerative device will be described. First, engine
The fuel injector 1 is provided with a fuel injection device 5.
Governor control unit 67 connected to launching device 5
Performs normal fuel injection control, and performs EC control described later.
Fuel injection restriction by rack restriction signal R from U60
Lock limit). This fuel injection limit (rack system
Limit) is the output by the motor operation of the pump / motor 40
The sum of the output from the engine 1 is the normal engine 1 only
Will not exceed the output corresponding to the maximum driving torque
The control of the engine is performed as described above. Also governor
The control unit 67 detects the engine speed NE.
And supplies the engine speed signal NE to the ECU 60.
I have. The transmission 3 has a vehicle speed detecting means.
Vehicle speed sensor 83, T / M reverse sensor 84,
T / M neutral sensor 85 and select position sensor
A vehicle speed signal V, T / M
Reverse signal TMR, T / M neutral signal TMN and
And the select position signal LTM to the ECU 60.
You. The brake power unit 70 has a normal
It is a source of braking force for service brakes (braking devices)
On the other hand, the braking force (compensation)
When using the service brake,
It is configured to perform control for weakening the braking force (braking
Force reduction correction means). FIG. 3 shows a brake power unit 70.
FIG. 3 is a schematic view showing the configuration of a service brake (brake).
Air brake (air over hydraulic)
Brakes). The brake valve 71 is
Air supply amount control valve operated by rake pedal 70a
The input side has an air tank as a high-pressure air supply source.
73 is connected via an air line P15. one
On the other hand, on the output side, an air pipe P1 forming a first air passage is provided.
0, the air booster (air master) 78 via P11
The output side of the air master 78 is connected to the braking force
Is connected. This
Wheel cylinder 15 is amplified by the air master 78.
Activated by the operating hydraulic pressure to generate a large braking force
It has become. The air lines P10 and P11 of the first air passage
A 3-port electromagnetic switching valve 75 is interposed between
Valve 75 is connected to lines P10 and P11 in the normal deenergized state.
Are set to communicate with each other (second position
), Enabling normal service brake operation.
The switching valve 75 has air branched from the air line P10.
The pipeline P13 is connected, and the differential pressure valve 7 is connected to the pipeline P13.
4 are interposed. The drive signal D10 from the ECU 60
When supplied to the switching valve 75, the switching valve 75 is biased to
Is switched to the position (first position) shown in FIG.
A second air passage via 74 is formed. In this case
The differential pressure valve 74 is connected to the input side (the brake valve 71 side).
Brake pressure PBK and brake on output side (air master 78 side)
The pressure difference from the master pressure PBM is a predetermined value (for example, 0.8 kgf /
cm^Two) Is opened only when the air pipe P1
Air can be circulated from the third side to the air line P11 side.
As a result, for example, an auxiliary brake
In such a case, the operation of the differential pressure valve of the second air passage is used.
The air corresponding to the amount of depression of the brake pedal 70a.
Pressure is supplied to the air master 78 with a delay of the differential pressure.
During this time, the braking force of the service brake is limited.
Only when the brake pedal 70a is largely operated.
The service brake can be activated. The air line P11 is separated from the air line P11.
Branch, safety valve 76, electromagnetic exhaust valve via air line P16
77. Safety valve 76 has two input ports
The input port 76a has the above-described air line.
P14 is connected, and the pipeline P12 is connected to the input port 76b.
The output side of the brake valve 71 is connected via the relay.
On the other hand, the above-mentioned air line P16 is connected to the output port 76c.
Has been continued. The safety valve 76 controls the brake pressure (control
Pressure) Built-in piston valve that responds to PBK
An air passage from the power port 76a to the output port 76c
(The third air passage) is connected to the control port from the input port 76b.
Pressure is a predetermined value (for example, 1.0 kgf / cm ^Two)
A mechanism that operates and shuts off the aforementioned piston valve
It is. The exhaust valve 77 is normally deenergized and connected to the line P16.
It is closed to shut off the atmosphere (as shown in Fig. 3
Position), the drive signal D12 is supplied from the ECU 60
And the third air passage is formed.
Air in the air master 78
You. For example, using an auxiliary brake driven by a pump
In such a case, the third air passage is opened.
The service braking force can be reduced. The brake provided on the brake valve 71
The pressure sensor 72 indicates the degree of operation of the brake pedal 70a.
Detects the brake pressure PBK generated according to the
The brake pressure detection signal PBK is supplied to the ECU 60.
The air line P14 has a brake mechanism for the air master 78.
A brake master pressure sensor 79 that detects the star pressure PBM is installed.
The brake master pressure detection signal PBM is
60. With these detection signals, the auxiliary
Switching control between rake operation and service brake operation is possible
It has become. In FIG. 3, one brake system (drive wheel) is used.
WR side), but branch from brake valve 71
The same applies to other brake systems (such as the driven wheel WF side)
The configuration and operation are the same. In addition, each wheel cylinder 15
It is provided for each wheel. FIG. 4 shows the energy regeneration device.
2 shows a configuration of an ECU 60 that controls the operation,
Includes a processor, a memory, an input / output circuit, and the like.
The input side of the ECU 60 is provided with a power on / off state signal.
SW 64 for supplying the accelerator pedal (not shown)
) To detect the amount of depression of the accelerator pedal.
The cell opening sensor 61 is connected to a clutch pedal (not shown).
Two clutches that operate and detect the connection and disconnection of the engine clutch
Sensors (CL1) 62, (CL2) 63, and
Various sensors including the brake pressure sensor 70a
You. Here, the engine clutch connection / disconnection sensor (CL1) 6
2 is a return limit (clutch) of a clutch pedal (not shown).
Connection) to supply a signal and set to ON.
The engine clutch connection / disconnection sensor (CL2) 63
Signal when the touch pedal (not shown)
Signal is set to ON and the sensor
(CL1) 62 and sensor (CL2) 63 in combination
Therefore, the half clutch state can be detected. On the other hand, the output side of the ECU 60
Various electromagnetic switching valves and various indicators are connected.
You. Indicators include the piston set of the accumulator.
Position signal LP from the sensor 87 and the pressure accumulation sensor 88
Accumulation signal indicating the amount of accumulated pressure with the accumulated pressure signal PAC from
Indicator 66 and the dog clutch disconnection sensor 92
The energy regeneration device is activated by the clutch connection / disconnection signal DCL.
A regenerative lamp 68 that indicates that it is operating and various
Diag lamp 6 for displaying an error according to an error signal
There are nine. Hereinafter, the braking energy configured as described above will be described.
FIGS. 5 to 5 show pump control and motor control of the gear regeneration device.
This will be described with reference to the flowchart shown in FIG. FIG.
FIG. 6 and FIG.
2 shows a control procedure of the loop control. First, the ECU 60
In step S10, the dog clutch from the dog clutch disconnection sensor 92
Dog clutch 51 is turned on by latch disconnection signal DCL
(Connection) or OFF (Disconnection) is determined. In addition, Doggura
The switch 51 is provided when the vehicle is in a predetermined driving state (for example, when the vehicle speed is 5).
Drive at select speeds other than reverse gear
Is engaged), the ECU 60
The drive signal D8 is supplied to the connection switching valve 53 and turned ON (connected).
Continuation) and at a predetermined vehicle speed (for example, 60 km / h)
To prevent the pump / motor 40 from exceeding its allowable capacity,
The drive signal D9 is supplied to the disconnection switching valve 54 and turned off (off).
). When the dog clutch 51 is in the connected state,
Pump / motor 40 includes drive shafts 10 and 12, a gear box
It is driven by the driving wheel WR via the reference numeral 50. If the result of the determination in step S10 is OFF (off)
If not, the process proceeds to step S20 in FIG. ECU60
Is the tilt angle to the proportional solenoid valve 42 in step S20.
The control signal value ELP is set to zero (ELP = 0). This
As a result, the pilot hydraulic pressure from the pilot hydraulic
Is held in a closed state, and the pitch of the tilt angle cylinder 41 is
The ston 41a is also held at the neutral position. And the pump
/ Keep tilt angle of swash plate 40d of motor 40 at zero
This allows the pump / motor 40 to function as a pump.
Will not work. Next, in step S21, switching is performed.
The drive signal D1 to the valve 44 is kept turned off,
In the FF (closed) state, furthermore, in step S22
Is unloaded to unload valve (normally open) 25
Output valve signal D3 is turned off (open)
The pressure oil pipeline P1 and the low pressure oil pipeline P2 are kept in communication.
You. In step S23, the ECU 60 executes the program
A value 0 (f1 = 0) is set to a flag f1 which is a control variable,
As a result, the fact that the pump control is not performed is stored.
You. Returning to step S10 in FIG.
If the determination result in the step is ON (connected),
Proceed to S11. In step S11, the ECU 60
The selection position of the transmission 3 is set to the reverse gear (
Position) is determined by the T / M reverse signal TMR.
And the determination result is YES (reverse), that is, the vehicle
If it is in the reverse gear position, step S20 in FIG.
Execute the following and do not perform pump control. On the other hand, the judgment result
Is NO, that is, if the vehicle is in the forward gear position, step S1
Execute Step 2. In step S12, the ECU 60 determines whether the vehicle
It is determined whether or not is stopped. This determination is based on the vehicle speed V
Is less than or equal to a predetermined value XV0 (for example, 1 km / h).
Judging by the number V, if V ≦ XV0 (1 km / h)
Do not execute loop control. On the other hand, if the determination result is V> XV0 (1 km
If / h), step S13 is executed. Step S1
3, the ECU 60 determines that the driver is using the brake pedal 70a.
Whether brake pressure PBK is generated by stepping on
The brake pressure signal PBK from the brake pressure sensor 72
PBK <XPB (for example, 0.2 kgf / c
m^Two) If the brake pedal 70a is not depressed
State, and does not execute the pump control. On the other hand,
Fruit is PBK ≧ XPB (0.2kgf / cm^Two) If energy
It is determined that all the operating conditions to be regenerated
Step S14 is executed. In step S14, the ECU 60
Tilt angle control signal value ELP of the swash plate 40d of the motor / motor 40
Is executed. How to set the ELP value
As a method, for example, as shown in FIG.
Calculate the reference value according to BK, and further calculate this reference value.
The oil temperature TOIL detected by the oil temperature sensor 91 of the dynamic oil tank,
Vehicle speed V detected by vehicle speed sensor 83, accumulator 2
It is corrected by the accumulated pressure amount PAC of 0 or the like and set to an appropriate value. Next, at step S15 in FIG.
0 is the control corresponding to the ELP value set as described above.
A control signal is output to the proportional solenoid valve 42 and the pump / motor 40
Is set to an angle corresponding to the signal value ELP. Next
In step S16, the drive signal D1 is supplied to the switching valve 44.
Is turned on (open), and the tilt angle cylinder 4
1 is supplied with pilot hydraulic pressure. Step S17
Now, unload between the low pressure oil pipeline P2 and the high pressure oil pipeline P1
Valve (normally open) 25 to unload valve signal D3
Therefore, it is turned ON (closed), and the pressure of the high-pressure oil pipeline P1 becomes low-pressure oil.
Block so as not to escape to pipeline P2. Further steps
In S18, in order to memorize that the pump is operating
The value 1 is set to the flag f1. Thus, the inclination of the pump / motor 40 is
The turning angle corresponds to the control signal value ELP to the proportional solenoid valve 42
When set to an angle, the pump / motor 40 is a pump
To operate and suck the hydraulic oil in the hydraulic oil tank 30,
This is pushed into the hydraulic oil chamber 23 of the accumulator 20 to store
Press. In the above pump control, the driver's brake pedal
Pump / model according to the amount of stepping on the oil, hydraulic oil temperature, vehicle speed, and accumulated pressure.
The tilt angle of the motor 40 is set, and the pump /
Data 40 performs the work corresponding to the amount of depression of the brake pedal, etc.
Thus, the braking energy is recovered. FIG. 8 to FIG.
2 shows a control procedure of motor control during forward / acceleration). First, E
Before starting the motor operation, the CU 60 executes step S30.
In step S40, motor control may be executed.
Determine whether or not. In step S30, the driver
The brake pressure is used to determine whether the intention is to start both.
PBK is a predetermined value XPB (for example, 0.2 kgf / cm^Two) Smaller
It is determined based on whether or not there is. Determination result of step S30
But PBK ≧ XPB (0.2kgf / cm^Two) If later
The motor control is performed by executing step S50 and subsequent steps in FIG.
Not performed. On the other hand, if the discrimination result is PBK <XPB (0.2 kgf / cm
^Two), The process proceeds to step S31. In step S31, the ECU 60 sets the
Indicates whether pump control is being performed or not.
Flag f1 is 1 (YES) or 0 (NO)
Is determined by When the flag f1 is 1 (YES),
During the pump control, a step shown in FIG.
Step S50 and subsequent steps are executed, and the motor control is not performed. On the other hand,
When lug f1 is 0 (NO), that is, during pump control,
If not, the process proceeds to step S32. In step S32, the ECU 60 sets the dog
If the clutch disconnection sensor 92 is ON (connected) or OFF (disconnected)
Is determined by the dog clutch connection / disconnection signal DCL.
If it is FF (cut), the motor control is not executed. on the other hand,
If the determination result is ON (connection), the process proceeds to step S33.
No. In step S33, the ECU 60
The selection position of option 3 is the reverse gear (reverse position).
It is determined whether or not there is by the T / M reverse signal TMR.
The determination result is YES (reverse), that is, the vehicle reverse gear.
If it is at the step position, the motor control is not executed. On the other hand,
If the result is NO, that is, if the vehicle is in the forward gear position, step S
Proceed to 34. In step S34, the ECU 60 sets the
Is the selection position of Simulation 3 neutral?
Whether it is or not is determined by the T / M neutral signal TMN.
If the determination result is YES (neutral), that is, the select position
If the vehicle is neutral, the driver can still start the vehicle.
The motor control is not performed because it is determined that there is no intention to perform the motor control. one
On the other hand, when the determined result is NO, the process proceeds to step S35.
No. In step S35, the ECU 60
Clutch 2 is connected or disconnected by a clutch disconnection sensor.
(CL2) Determined by the clutch connection / disconnection signal CL2 of 63
If it is disconnected, select transmission 3
Motor control is performed as when the position is neutral.
Absent. On the other hand, if it is in the connected state (including the half-clutch state)
For example, the process proceeds to step S36 in FIG. In step S36, the ECU 60 sets
Whether the accumulator 20 is filled with hydraulic oil or not.
To the piston position signal LP from the piston position sensor 87
Therefore, it is determined. The piston 21 is set at the position just before
If the determined piston position sensor 87 is 0FF, that is, hydraulic oil
Is empty, the hydraulic oil is stored in the accumulator 20.
In such a case, the motor control
Do not perform control. On the other hand, the piston position sensor 87 is ON
That is, if the accumulator 20 is filled with hydraulic oil
Otherwise, the process proceeds to step S37. In step S37, the ECU 60 determines the vehicle speed.
Whether V is equal to or less than a predetermined value XV2 (for example, 65 km / h)
Is determined by the vehicle speed signal V, and a predetermined value XV2 (65 km / h) is determined.
If the pump / motor 40 exceeds the allowable capacity,
Motor control is not performed to prevent
No. On the other hand, if it is less than the predetermined value XV2 (65 km / h),
Proceed to step S38. In step S38, the ECU 60 sets the
The vehicle speed V is set to a predetermined value XV1 (for example, 5 km
/ h), if the value is smaller than the XV1 value, step S3
9 and check that the clutch 2 is completely connected
Clutch connection / disconnection sensor (CL1) 6
The determination is made based on the clutch connection / disconnection signal CL1. Step
The vehicle speed V is determined to be the predetermined value XV1 (5 km / h) by the determination in step S38.
Clutch 2 fully connected despite being smaller
If it is determined that the clutch
There is some abnormality in the sensors 62, 63, the vehicle speed sensor 83, etc.
Therefore, the motor control is not performed for safety. On the other hand,
If the switch connection / disconnection signal CL1 indicates the OFF state,
In addition to the determination result of step S35, the clutch 2
Is half-clutched, in such a case
Proceeds to step S40. In step S40, ECU 60 sets
Cell opening L Aθ is larger than motor start opening discrimination value Xθ1
Is determined by the accelerator opening signal LAθ.
You. The above-described determination value Xθ1 is set according to the vehicle speed V,
FIG. 16 shows the vehicle speed V and the discrimination value X set thereby.
The relationship with θ1 is shown. Accelerator opening LAθ is determined
When the value is smaller than the value Xθ1 (LAθ <Xθ1), the regenerative energy
Judging that it is not necessary to accelerate the vehicle due to energy
Therefore, the motor is not operated. On the other hand, from the discrimination value Xθ1
If it is large (LAθ ≧ Xθ1), step S41
To start the motor control. If the motor control is not executed, the ECU
60 is the proportional solenoid valve 4 in step S50 of FIG.
The tilt angle control signal value ELM to 2 is set to zero (ELM = 0)
Set and output this. Thereby, the tilt angle cylinder 4
The first piston 41a is held in the neutral position, and the pump / model
When the tilt angle of the swash plate 40d of the motor 40 becomes zero, the pump
/ Motor 40 does not function as a motor. S
In step S51, the piston 41 of the tilt angle cylinder 41
a switching valve 44 for controlling the supply and discharge of pilot oil for driving a
Is turned off (closed) by rejecting the drive signal D1. Step
In step S52, the shut-off valve which is ON (open) when the motor is operated
24 is turned off (closed) by shutting off the shut-off valve signal D2.
Of hydraulic oil from the accumulator 20 to the pump / motor 40
Stop the flow. In step S53, the low-pressure oil pipeline P2 is
Unload valve (normal for high pressure oil pipeline P1)
Open) 25, stop output of unload valve signal D3
To open (open) the high-pressure oil line P1 and the low-pressure oil line P
Let 2 communicate. In step S54, when the motor is operating
Rack limit signal sent to engine 1
R is turned off by turning it off, and in step S55,
Refuse the rack limit valid signal RE that was sent
F. Finally, in step S56, the program control
A value 0 (f2 = 0) is set in a flag f2 which is a number, and
To store that the motor control is not performed. On the other hand, by executing step S41, the motor
When the control is started, the ECU 60 sets the pump / motor 4
0 to set the tilt angle control signal value ELM of the swash plate 40d of zero.
Execute the routine. As a method of setting the ELM value,
First, the accelerator opening L Aθ and the vehicle speed V (instead of the vehicle speed V)
The reference value is set according to the engine speed NE.
I do. FIG. 17 is stored in the storage device of the ECU 60.
The ELM map shown in FIG.
ELM reference value according to vehicle speed V and accelerator opening L Aθ
(XM0, XM1,...). Next, the oil temperature sensor
Correction according to oil temperature of hydraulic oil tank 30 detected at 91
Find the coefficient, multiply this by the ELM reference value, and
The tilt angle control signal ELM value is calculated. Accelerator open
The tilt angle control signal value ELM is changed by the degree LAθ.
That is, when starting and accelerating with only the normal engine 1
Response similar to the accelerator operation response of
As shown in FIG.
It is to change the force torque value. Also, the vehicle speed V (also
Is the tilt angle control signal value EL depending on the engine speed NE).
Changing M provides high torque at low speeds,
In the medium speed range, supply enough torque for acceleration.
It is possible. The correction based on the oil temperature of the hydraulic oil tank 30
If the temperature is lower than 70 ° C., for example, it is not necessary to correct the ELM value.
However, when the oil temperature is 70 ° C. or more, the tilt angle control signal value ELM
Is corrected to reduce. At high temperatures, hydraulic fluid viscosity
And the pump / motor 40 may be seized.
Therefore, this is prevented by reducing the motor capacity.
You. Next, the ECU 60 executes step S in FIG.
At 42, the ELM value set as described above is
A corresponding control signal is output to the proportional solenoid valve 42, and step S
At 43, the drive signal D1 is output and the switching valve 44 is turned on.
(Open) and the tilt angle cylinder 4
1 is supplied with pilot hydraulic pressure. This allows the pump /
The swash plate 40d of the motor 40 has a tilt angle corresponding to the ELM value.
Is set to Next, in step S44, the shutoff valve 26
To output the shut-off valve signal D2 and turn it on (open)
At the same time, in step S45, the unload valve (NO)
Supply the unload valve signal D3 to the
Is turned on (closed), and the pressure in the high-pressure oil pipeline P1 is low.
It shuts off so that it may not escape to the pressure oil pipeline P2. This allows
The pump / motor 40 is stored in the accumulator
Driven by high-pressure hydraulic oil, and its driving force is
0e, the gearbox 50, and the drive shafts 12 and 10,
It is transmitted to the driving wheel WR, and a part of the driving force at the time of starting or accelerating is
Cover. In step S46, the ECU 60 sets the engine
For restricting the fuel supply of the fuel injection device 5 of the gin 1
Control signal R and the governor control unit 67
The fuel is supplied to the fuel injection device 5 via the This rack limit signal
R is the output torque of the engine 1 during motor control
The output limit amount on the engine 1 side is
Engine speed NE and accumulated pressure in accumulator 20
Determined based on PAC. And to the fuel injection device 5
Ensure that the supplied engine 1 output limit is executed
Therefore, in step S47, the rack limit valid signal
RE is output to the governor control unit 67,
Malfunction due to noise etc. is prevented. Finally, step S
At 48, the value 1 is set to the flag f2 which is a program control variable.
Set, and remember that the motor is running
You. FIGS. 12 to 14 show the braking operation according to the present invention.
In the control routine of the air pressure reduction control of the service brake
Yes, the execution of this routine causes
Adjust the braking force ratio between the auxiliary brake and the service brake
I have. It is easy to understand the control procedure of this air pressure reduction control.
During operation of the vehicle, the brake pedal 70a is depressed.
The brake pedal 70a is
The control executed until the vehicle is stopped
The description will be given sequentially in order. The ECU 60 first executes step S7 in FIG.
0 is repeatedly executed, and the braking energy regenerating device
The pump control flag f1 is set to the value 1
It is determined based on whether or not it has been set. As mentioned above
The driver depresses the brake pedal 70a and the pump
Until control is started, the flag f1 is set to the value 1.
During normal driving, the determination in step S70 is made.
The result is NO (negative), and in such a case,
After performing the determination in step S80,
Proceeding to S79, the switching valve 75 and the exhaust valve 77 are deenergized (O
FF) and the routine ends. like this
Until the pump control of the braking energy regeneration device is started.
In both cases, the switching valve 75 and the exhaust valve 77 are both in the deenergized state (the
2 position) and the differential pressure valve 74 is provided.
Since the pipe P13 is shut off, the brake valve 71
The discharge air pressure is in a state where it can be directly supplied to the air master 78.
ing. Next, the brake pedal is operated by the driver during traveling.
The dull 70a is depressed and the brake energy regeneration device
When the pump control is started, the pump control flag f1 is set to a value of 1.
Is set, and the determination result of step S70 in FIG.
S (Yes), and then step S71 is executed. S
In step S71, the program control variable flag f (LP) is
It is determined whether the value is 0. This flag f (LP) activates the pump
Discharge pressure PHY, that is, pump / motor 40 and accumulator
The operating oil pressure of the pipeline P1 between the radiator 20 and the
(For example, 100kgf / cm^Two) If it is more than,
The regenerative device generates an effective braking force as an auxiliary brake
Set to 0 if pumping is possible
And the discharge pressure PHY is reduced to a predetermined value XPT (100
kgf / cm^Two) Is set to a value of 1
You. Immediately after the start of pump control, the normal flag f (LP) is
The value is set to 1, and the process proceeds to step S80. In step S80, the pump discharge pressure PHY is
Predetermined value XPT (100kgf / cm^Two) Determine if it is more than
If the determination result is YES, ejection is performed in step S81.
The pressure PHY is a predetermined value XPT (100 kgf / cm^Two)
The flag f (LP) is set to a value of 0 to store
If the decision result in the step S80 is NO, the discharge pressure PHY becomes a predetermined value X
PT (100kgf / cm^TwoIf nothing is reached, do nothing
The process proceeds to step S79 in FIG. Therefore, pump control
Even if started, the discharge pressure PHY of the pump / motor 40 is predetermined
Value XPT (100kgf / cm^Two)
Step S79 is repeatedly executed, and the switching valve 75 and
The exhaust valve 77 is kept in a deenergized (OFF) state. this
In this case, the exhaust valve 77 is also kept deenergized (OFF).
Therefore, the discharge air pressure of the brake valve 71 is directly
Is supplied to the motor 78 and the service brake
The normal braking according to the amount of depression of the brake pedal 70a
Force will be generated. Thus, the braking energy
Even if the pump control of the raw device is started, the pump discharge pressure PHY
Is the specified value XPT (100kgf / cm^TwoRegeneration until it exceeds
Is not generating effective braking force as an auxiliary brake.
As a result, the air pressure supplied to the air master 78 decreases.
Not pressed. The pump control of the braking energy regeneration device proceeds.
And the pump discharge pressure PHY reaches a predetermined value XPT (100 kgf / cm^Two)
Above which the regenerative device is effective as an auxiliary brake
The flag f (LP) is reset to the value 0.
It is set (steps S80, S81). Flag f (L
When (P) is reset to 0, step S71 in FIG.
Is YES (yes), and the result of step S is
Go to 72. In step S72, the vehicle speed V is set to a predetermined value XVF.
(For example, 4 km / h). This discrimination
Ends the air pressure reduction control of the service brake described later
This is to determine whether or not to break the vehicle.
Depress the key pedal 70a to decelerate.
In most cases, the answer is usually YES (yes), in which case
Proceed to step S73. In step S73, a so-called panic
The brake pressure PBK is used to determine whether or not rake (rapid braking) has been performed.
Is a predetermined value XPN (for example, 2.0 kgf / cm^Two)
Determine. If the determination result is YES, the process of FIG.
Proceeding to step S79, the switching valve 75 and the exhaust valve 77
(OFF) to reduce the air pressure of the service brake
Do not do. In addition, during the air pressure reduction control of the service brake
When the panic brake is implemented in
The service will be suspended during panic braking.
Braking with braking and braking energy regeneration
Movements are performed simultaneously, which is appropriate for sudden braking.
Can be dealt with. Also, the brake valve 71
Because air pressure acts on the safety valve as control pressure
At the same time, the safety valve 76 operates to allow the exhaust air from the air master 78 to pass.
The communication between pipeline P11 and pipeline P16 is also
And The brake pressure PBK is adjusted to a predetermined value XPN (2.0 kgf /
cm^Two) For general braking that is smaller and not panic brake
(When the determination result of step S73 is NO (No))
Proceeds to step S75 in FIG. In step S75
Is controlled by the driver's depressing operation of the brake pedal 70a.
Changes in brake pressure PBK generated by brake valve 71
Whether the amount is large or small (ie, the operating speed of the brake pedal 70a).
The degree is fast or slow). Change in brake pressure PBK
The threshold value for determining whether the amount is large or small is determined according to the vehicle speed V.
As shown in FIG. 18, for example,
If the vehicle speed V is high,
It is determined that the amount of change is large just by operating the dull 70a,
On the other hand, when the vehicle speed V is low, the brake pedal 70
If a is not operated, the change amount will be regarded as small.
ing. Note that the amount of change in the brake pressure PBK is the brake pressure P
It can be obtained from the difference between the previous detected value of BK and the current detected value.
Detected during the operation of a series of brake pedals 70a.
The maximum value of the brake pressure change amount is stored, and step S75 is performed.
Is determined by the stored value each time is executed. The ECU 60 calculates the detected brake operation speed.
The switching valve 75 and the exhaust valve 77 are changed according to the size of
Switching control is performed according to different procedures. First, blur
If the brake operation speed is high, the auxiliary
Even if the mark starts to work, it continues for a predetermined time (for example, 0.
(5 seconds) to maintain the braking force of the service brake
Control. That is, the determination result of step S75
Is large and it is confirmed that the brakes are operated quickly
In step S76, the timer (hereinafter, the 0.5 second timer
Is set). This timer is set once.
When the brake pedal 70a is operated,
Even if step S76 is repeatedly executed,
Absent. And the brake master pressure PBM is enough brake
It is determined whether the pressure to generate the force has been reached (step
S77), the 0.5 second time set in the previous step S78
After judging the elapse of the predetermined time (0.5 seconds) by the imager
(Step S78), proceeding to step S79, the switching valve 7
5 and the drive signal D12 of the exhaust valve 77.
And keep them in the OFF state. This
The first air passages (P10, P11) are opened
The air pressure of the brake valve 71 is directly
8 and the braking by the service brake is continued.
You. A predetermined time (0.5
(Second) is determined (result of determination in step S78)
Is YES), before the predetermined time (0.5 seconds) elapses.
Rake master pressure PBM generates sufficient braking force
When the discrimination pressure is reached (the discrimination result of step S77 is
The vehicle speed V by the braking force of the service brake
Is judged to have sufficiently decelerated, and the air after step S90 is determined.
The pressure reduction control is executed. Step S77
Used to determine the magnitude of brake master pressure PBM in
The value is, for example, according to the vehicle speed V as shown in FIG.
Is set to be a larger value as is larger. Only
Meanwhile, the discrimination threshold that is set depends on whether the differential pressure valve 74 is open.
Differential pressure (for example, 0.8kgf / cm^Two) Set smaller
Is done. On the other hand, in step S75, the brake operation
It was determined that the operation speed (the amount of change in the air pressure PBK) was low.
In this case, the process proceeds to step S90, and the air pressure reduction control is immediately performed.
Will run. In step S90, the service
As the first stage for limiting the rake braking force, the switching valve 75
, A drive signal D10 is supplied and turned ON, and the differential pressure valve 7
4 to open the second air passage, and set this state at a predetermined time.
Hold (for example, for 0.2 seconds) (step
S91), the inlet and outlet sides of the differential pressure valve 74
Service brake does not work unless there is a constant pressure difference
To That is, the discharge air pressure P of the brake valve 71
If BK does not reach the predetermined value, the air pressure is supplied to the air master 78.
Is not supplied, the amount of depression of the brake pedal 70a is small.
The braking force of the service brake does not work and the braking
Only the auxiliary brake of the energy regeneration device will work.
In addition, the amount of depression of the brake pedal 70a becomes large,
When the valve 74 opens, the service brake is applied from that point on.
A braking force will be generated. Thus, the brake pedal
Even if the step 70a is stepped on, the switching valve 75 and the differential pressure valve 74
Therefore, the differential pressure (0.8 kgf / c
m^Two) The service brake will be activated with a delay
During this time, braking is performed by the braking energy regeneration device.
It is. In step S91, the switching valve 75 is opened.
It is determined that a predetermined time (0.2 seconds) has elapsed since
Then, the process proceeds to step S92 in FIG. In step S92, the pump / motor
The discharge pressure PHY of 40 is a predetermined value XPT (100 kgf / cm^Two )that's all
Is determined, and if the determination result is YES, step
In step S93, the flag f (LP) is reset to 0, and the pump is activated.
Double-check that braking is actually occurring. So
Then, in step S94, the exhaust valve 77 described later is released.
Whether the braking force of the service brake has weakened
At a predetermined value XPL (for example, 0.
3kgf / cm^Two ) It is determined by whether or not the above. If the determination result is NO
In that case, the braking force of the service brake is weakened sufficiently
The determination can be made, the process proceeds to step S102, and the exhaust valve 77 is closed.
To limit the braking force of the service brake (air pressure reduction).
I will. When the air pressure is completely released from the air master 78,
There is a delay when applying the service brake
Will be. On the other hand, if the decision result in the step S94 is YES
In the case of, the air in the air master 78 has
Can not be determined, and in this case, the process proceeds to the next step S95.
No. In step S95, the brake pressure PBK and the brake pressure
The pressure difference | PBK-PBM | with the rake master pressure PBM is the differential pressure
A predetermined value XPD which is a differential pressure value at which the valve 74 opens (for example,
0.8kgf / cm^Two ) To determine whether it is more than
Is YES, the braking force from the service brake
It is determined that the state is necessary, and the process proceeds to step S102.
Close the exhaust valve 77 and stop bleeding air from the air master 78
You. On the other hand, if the decision result in the step S95 is NO,
In this case, if the depression amount of the brake pedal 70a is small,
In this case, since the differential pressure valve 74 is closed,
The following steps S96 and S97 are executed to open the exhaust valve 77.
It can be done. When the differential pressure valve 74 is closed,
Even if the exhaust valve 77 is opened, a large amount of pressure
There is no worry that A will escape. In step S96, the next step S97
Supplies the drive signal D12 to the exhaust valve 77 and turns it on.
Whether a predetermined time (for example, 1 second) has elapsed since the
Is determined. If the determination result is NO, it is still at the predetermined time
Time (one second) has not passed, and
In step S97, the drive signal D12 is continuously supplied to the exhaust valve 77,
Hold open state. That is, the ECU 60 controls the exhaust valve 7
7 is opened for a predetermined time (1 second), and the air master 78 is opened.
Exhaust air from. Air supplied to air master 78
By reducing the pressure, the service brake
The power will be weakened. By bleeding air from the air master 78,
Predetermined brake master pressure PBM within specified time (1 second)
Pressure XPL (0.3kgf / cm^Two ) If it drops below,
Step S102 is executed according to the determination in step S94.
And the exhaust valve 77 is closed (OFF).
Despite the lapse of a predetermined time (1 second),
If the determination result of step S96 is YES (Yes),
The brake master pressure PBM is still determined by step S94.
Predetermined value XPL (0.3kgf / cm^Two ) If there are more than
The pressure difference | PBK−PBM |
PD (0.8kgf / cm^Two ) Or more, the exhaust
An abnormality such as a defective air release of the valve 77 is considered. like this
In this case, before immediately determining that there is an abnormality, step S105
, The brake pressure PBK is equal to the predetermined pressure XPS (for example, 1.
0kgf / cm^Two ) It is determined whether or not it is above. Brake pressure
PBK is at a specified pressure XPS (1.0 kgf / cm^Two )
Is input to the safety valve 76 as the control pressure.
All valves 76 are operating, and in such a case, the exhaust valve
77, the differential pressure valve 74, etc., can be determined to be in a normal state, and step S
In 102, the drive signal D12 of the exhaust valve 77 is turned off.
Is turned off once. At this time, the
Since the timer used separately is also reset, step S
When the step 96 is executed again, the exhaust valve 77 is turned on for a predetermined time (one second).
Only during the period). That is, the exhaust valve 77
When the air pressure is reduced by opening the valve,
Step S105 is executed and the exhaust valve 77 and the safety valve 76
Anomalies are monitored, which ensures safety. On the other hand, if the decision result in the step S105 is NO
In the case of, the operation amount of the brake pedal 70a is small,
Safety valve 76 should not be operating,
Despite the condition, the air in the air master 78 has run out.
If not, the exhaust valve 77, safety valve 76, etc.
(Error) state can be considered, and step S106
The drive signal D12 of the exhaust valve 77 is once turned off and
After setting to F, an error code is output in step S107.
To inform the driver of the abnormality,
Move on to execution. When the brake pedal 70a is pulled back,
And the tilt angle of the pump / motor 40 is small.
, The discharge pressure PHY decreases accordingly.
In step S92 of FIG. 14, the discharge pressure PHY becomes the predetermined value XPT.
(100kgf / cm^Two ) Less than (determination result is NO (negative))
Is determined, step S100 is executed, and the switching valve
75, the driving signal D10 supplied to the
F, the first air passage is opened, and the brake valve 71
Is supplied directly to the air master 78. And
In step S101, the discharge pressure PHY due to the pump operation
Is not sufficient and the braking force of the auxiliary brake is small.
To store, the value of the flag f (LP) is set to 1 and then
Then, the process proceeds to step S102, where the drive signal D1 for the exhaust valve 77 is
2 and hold this in the OFF state, and the air master 78
To prevent the air pressure from being exhausted. by this
The service brake will work. Further, the air pressure of the service brake is reduced.
While the auxiliary brake is activated and the vehicle speed decreases,
In step S72 of FIG. 12, the vehicle speed V is increased to a predetermined value XVF.
(E.g., 4 km / h)
Step S79 of FIG. 13 is executed, and the switching valve 75 and the exhaust
The air valve 77 is deenergized (OFF) and the service
The air pressure reduction control of the brake is ended. The vehicle speed is the predetermined value XVF
(4km / h) or less for service brakes
Is determined to be necessary, and the air pressure reduction control of the service brake
Not performed. Note that the service brake of the above-described embodiment is used.
The pressure reduction control has been described for the rear wheels (drive wheels).
The same applies to the front wheels (driven wheels) and each wheel control.
And the description is omitted. [0074] As described above, the braking energy circuit of the present invention is used.
According to the vehicle equipped with the raw device, the operation amount of the brake pedal
Braking pressure generating means for generating a braking pressure according to
Connected to a dynamic pressure generating means for reducing the braking pressure at a predetermined ratio.
A pressure reducing valve for outputting a pressurized pressure, and the braking pressure generating means
State and before supplying pressure from the wheel directly to the wheel braking device
The second which supplies the pressure from the pressure reducing valve to the wheel braking device
Switching valve capable of switching between states, and the braking pressure generating means
Pressure detecting means for detecting a braking pressure generated by a vehicle, and a vehicle
When the hydraulic pump / motor is operated during braking
TogetherThe switching valve is in the second state., The braking pressure detection
When the amount of change in the braking pressure detected by the means is equal to or greater than the threshold,
The switching valve is switched to the first state, and is controlled by the pressure reducing valve.
Control means for prohibiting pressure reduction of the braking pressure.
As a result, the brake
Service during braking when the brake pedal is strongly operated.
Regeneration of braking energy without reducing braking force by braking
It is possible to obtain sufficient braking force in combination with the braking force by the device
it can.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing a part of a braking energy regenerating device to which an embodiment of the present invention is applied and a configuration of a vehicle equipped with the device. FIG. 2 is a hydraulic circuit diagram showing a main configuration of a braking energy regeneration device of the present invention. FIG. 3 is an air circuit diagram showing a main configuration of a brake power unit according to the present invention. FIG. 4 is a block diagram showing a configuration of an electronic control unit (ECU) of the braking energy regeneration device according to the present invention. FIG. 5 is a part of a flowchart of a pump control routine executed by an ECU 60 in FIG. 4; FIG. 6 is a part of a flowchart of a pump control routine that follows the flowchart of FIG. 5; FIG. 7 is the remaining part of the flowchart of the pump control routine following the flowchart of FIG. 5; FIG. 8 is a part of a flowchart of a motor control routine executed by the ECU 60 in FIG. 4; FIG. 9 is a part of a flowchart of a motor control routine that follows the flowchart of FIG. 8; FIG. 10 is a part of a flowchart of a motor control routine following the flowchart of FIG. 9; 11 is the remainder of the flowchart of the motor control routine that follows the flowchart of FIG. 9; FIG. 12 is a part of a flowchart of a brake air pressure reduction control routine executed by the ECU 60 according to the present invention. FIG. 13 is a part of a flowchart of a brake air pressure reduction control routine that follows the flowchart of FIG. 12; FIG. 14 is the remainder of the flowchart of the brake air pressure reduction control routine that follows the flowchart of FIG. FIG. 15 is a graph showing an example of a relationship between a brake pressure PBK and a tilt angle control signal value ELP at the time of pump control of the braking energy regeneration device. FIG. 16 is a graph showing an example of a relationship between a vehicle speed V and a discrimination value Xθ1 (accelerator start opening) at the time of motor control of the braking energy regeneration device. FIG. 17 is a graph showing an example of a relationship between a vehicle speed V, an accelerator opening, and a tilt angle control signal value ELM corresponding to these during a motor control of the braking energy regeneration device. FIG. 18 is a graph showing an example of a relationship between a vehicle speed V and a threshold value for determining a change amount of a brake pressure PBK during brake air pressure reduction control. FIG. 19 is a graph showing an example of a relationship between a vehicle speed V and a determination threshold value of a brake master pressure PBM during brake air pressure reduction control. [Description of Signs] 1 Engine 2 Clutch 3 Transmission 10 Rear wheel drive shaft 15 Wheel cylinder (wheel braking device) 20 Accumulator 30 Low pressure hydraulic oil tank 40 Swash plate type variable displacement piston pump / motor 41 Tilt cylinder 42 Proportional solenoid valve 43 Pilot Hydraulic source 50 Gear box 51 Dog clutch 60 Control unit (ECU) 67 Governor control unit 70 Brake power unit (Brake pressure generating means) 70a Brake pedal 71 Brake valve 72 Brake pressure sensor (Brake pressure detecting means) 73 Air tank 74 Differential pressure valve (Reducing valve) 75 3-port switching valve (switching valve between first state and second state) 76 Safety valve 77 Exhaust valve 78 Air master 79 Brake master pressure sensor

Continuation of the front page (56) References JP-A-5-112225 (JP, A) JP-A-5-4566 (JP, A) JP-A-4-121260 (JP, A) JP-A-4-135958 (JP) , A) JP-A-5-178183 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60T 1/10 B60K 25/00

Claims (1)

(57) [Claim 1] An oil passage between a low-pressure tank for storing hydraulic oil and an accumulator for accumulating hydraulic energy is connected to a drive system member of a vehicle via a clutch. The hydraulic pump / motor is operated during braking to convert the braking energy into hydraulic energy and store it in the accumulator. On the other hand, when starting / accelerating, the motor is operated to convert the hydraulic energy stored in the accumulator into the starting / acceleration energy. In a vehicle provided with a braking energy regenerating device used as a brake pressure generating means for generating a braking pressure in accordance with an operation amount of a brake pedal, the braking pressure being reduced at a predetermined ratio connected to the braking pressure generating means. A pressure reducing valve that outputs pressure, a first state in which pressure from the braking pressure generating means is directly supplied to a wheel braking device, and a pressure from the pressure reducing valve. , A switching valve capable of switching between a second state for supplying to the wheel braking device, a braking pressure detecting means for detecting a braking pressure generated by the braking pressure generating means, and a pump operating the hydraulic pump / motor during vehicle braking. And the switching valve is
In the second state , when the change amount of the braking pressure detected by the braking pressure detecting means is equal to or more than a threshold value, the switching valve is switched to the first state, and the reduction of the braking pressure by the pressure reducing valve is prohibited. A vehicle provided with a braking energy regenerating device, comprising: a control unit.