JP2947101B2 - 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 a braking energy regenerating apparatus that regenerates braking energy when braking a vehicle and uses the braking energy to assist driving force when starting or accelerating.

[0002]

2. Description of the Related Art Conventionally, a pump / motor or the like is provided as energy conversion means on wheels of a vehicle such as an automobile, and this pump / motor is switched to a pump mode during vehicle braking to regenerate rotational drive energy from the wheels. The rotational drive energy is stored as fluid pressure energy in an accumulator or the like, or when the vehicle starts, the pump / motor is switched to a motor mode, and the fluid pressure energy from the accumulator or the like is converted into rotational drive energy. There has been proposed a braking energy regenerating device that assists the driving force when the vehicle starts or accelerates (for example, Japanese Patent Publication No. 4-64900).

[0003] Such a braking energy regenerating device will be briefly described. Usually, a pump / motor, a clutch for connecting and disconnecting the pump / motor to and from a wheel, and a low-pressure hydraulic oil tank for storing hydraulic oil at a low pressure. An accumulator capable of accumulating hydraulic oil from a low-pressure hydraulic oil tank at a high pressure, a pressurized air tank for pressurizing the low-pressure hydraulic oil tank, and a drain tank for storing hydraulic oil drained from the accumulator via a pump / motor. Is provided.

During normal running of the vehicle, the clutch is disengaged, the pump / motor does not operate, and the braking energy regeneration device does not operate. When the vehicle is being braked, the clutch is brought into a contact state, and the pump / motor is driven as a pump by the rotational driving force input from the wheel side. By pumping the hydraulic oil from the low-pressure hydraulic oil tank and accumulating the hydraulic oil in the accumulator in a high-pressure state, the work by driving the pump becomes a load on the vehicle and acts as a braking force.

On the other hand, when the vehicle starts or accelerates, the pump / motor is operated as a motor by the high-pressure hydraulic oil in the accumulator, and the rotational driving force of this motor is used as the driving force of the wheels. At this time, the hydraulic oil discharged from the pump / motor is stored in the drain tank,
It is returned to the low-pressure hydraulic oil tank again, and the above-described circulation is repeated. The low-pressure hydraulic oil tank is pressurized by air (air pressure) supplied from a pressurized air tank. This is because when the pump / motor operates as a pump,
This is for facilitating the suction of the hydraulic oil.

[0006] The pressurized air is opened to the atmosphere when the engine is stopped by turning on and off a solenoid valve provided between the low-pressure hydraulic oil tank and the pressurized air tank, so that the low-pressure hydraulic oil tank is at atmospheric pressure. . This is because if the low-pressure hydraulic oil tank is kept pressurized when the engine is stopped, this pressure causes hydraulic oil to flow from the low-pressure hydraulic oil tank to the drain tank via a pump / motor, and then to operate from the drain tank. This is because the oil may overflow.

[0007] In such a conventional braking energy regenerating apparatus, the solenoid valve is controlled to be turned on / off only by determining whether or not the engine is operating. Even when the engine is restarted immediately, the pressurized air in the low-pressure hydraulic oil tank is released (discharged) to the atmosphere. Such control is performed, for example, according to a flowchart shown in FIG. First, in step S102, it is determined whether or not the engine is rotating by, for example, an engine speed sensor or the like. If it is determined that the engine is rotating, the process proceeds to step S103, where the solenoid valve is turned on, and the low pressure Pressurize the hydraulic oil tank.

If it is determined in step S104 that the engine is not rotating, then step S104 is executed.
The process goes to 103 to turn off the solenoid valve and discharge air.

[0009]

However, when the pressurized air is released to the atmosphere (at the time of air discharge), a relatively loud noise is generated for several seconds, so that when the engine stalls, discomfort is increased for the driver. There is a problem to do. Also,
When the engine stalls, it is usually considered that the driver immediately restarts the engine. In this case, since the air tank is pressurized again and the pressurized air is supplied into the low-pressure hydraulic oil tank, immediately discharging the pressurized air at the time of engine stall is not efficient from the viewpoint of effective use of energy. There is a problem that.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and provides a braking energy regenerating apparatus capable of detecting a vehicle stall when the vehicle stalls and suppressing wasteful energy consumption. With the goal.

[0011]

According to a first aspect of the present invention, there is provided a braking energy regenerating apparatus according to the first aspect of the present invention, wherein a fluid path between a working fluid storing means for storing a working fluid and a pressure accumulating means for accumulating fluid pressure energy. The energy converting means, which is interposed in the vehicle and is connected to the drive system member of the vehicle via the disconnecting means, is operated by a pump at the time of braking to store the fluid pressure energy in the pressure accumulating means, thereby converting the fluid pressure energy into braking energy. On the other hand, at the time of starting acceleration, the motor is operated and the fluid pressure energy accumulated in the accumulator is used as the starting acceleration energy,
When the engine is stopped, the braking fluid regenerating device basically opens the working fluid storing means to the atmosphere, and further includes an engine stall detecting means for detecting an engine stall that switches from an operating state to a stopped state without a stop operation. When the engine stall detecting means detects that the engine has been switched from the operating state to the stopped state, the engine is controlled not to open the working fluid storing means to the atmosphere within a predetermined time.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the engine stall detecting means includes an ignition key turned on and an engine rotation speed reduced. It is characterized in that the engine stall is detected when the value is 0. A pressurizing means for pressurizing the pressure of the working fluid in the working fluid storage means to a pressure lower than that of the pressure accumulating means and to a pressure higher than the atmospheric pressure; Pressurized state switching means capable of switching between a pressurized state of supplying the working fluid storing means to the working fluid storing means and an open state of releasing the pressurizing force from the pressurizing means and opening the working fluid storing part to atmospheric pressure. And pressurized state control means for controlling the pressurized state switching means to be in a pressurized state when the engine of the vehicle is operating and to basically open the pressurized state switch means when the engine is stopped. Further, the pressurized state control means may be configured to switch the pressurized state switching means to an open state when a predetermined time has elapsed after the engine stall . With this configuration, the predetermined time has elapsed.
Thereafter, the inside of the working fluid reservoir can be brought to atmospheric pressure.

Further, the a drain tank for reserving the working fluid, the working fluid quantity detection capable of detecting a working fluid amount stored in the drain tank to be discharged from said energy conversion means to time of starting or acceleration of the vehicle When the pressurized state control means determines that the amount of working fluid in the drain tank is equal to or more than a predetermined amount based on information from the working fluid amount detecting means, the engine is stalled, and Even if the predetermined time has not elapsed, the pressure state switching means may be switched to the open state . in this way
When configured, the pressure in the working fluid storage
Hydraulic oil flowing from the working fluid reservoir to the drain tank
Water from the drain tank to the outside.
There is an advantage that can be.

Further, a drain tank for reserving the working fluid discharged from said energy conversion means to time of starting or acceleration of the vehicle, the hydraulic fluid of the drain tank becomes excessive the excess working fluid A reservoir tank for storing, and a working fluid amount detecting means capable of detecting an amount of working fluid stored in the reservoir tank, wherein the pressurized state control means is provided based on information from the working fluid amount detecting means. When the working fluid in the reservoir tank is determined to be equal to or greater than the predetermined amount, the engine may not have passed the predetermined time stalled, configured to switch the pressurizing state switching device in the open state You may. Configured in this way
In this case, the pressure in the working fluid reservoir
From body reservoir to reservoir tank via drain tank
The flowing hydraulic oil flows out of the reverberation tank to the outside.
There is also an advantage that can be prevented.

Further, together with the pressurizing means is constituted by a pressurized air tank, even if the working fluid reservoir by pressurized air from the pressurizing air tank is configured to be pressurized
In this case, compare the pressure state of the working fluid reservoir.
Can be easily managed. The braking energy regenerating device according to the third aspect of the present invention is operated by receiving a rotational energy of an axle of a vehicle, a working fluid storing means for storing a working fluid, a pressure accumulating means for storing the working fluid in a high pressure state. Energy that can take a pump mode in which the working fluid from the working fluid storing means is pressurized and supplied to the pressure accumulating means as fluid pressure energy, and a motor mode in which the fluid pressure energy stored in the pressure accumulating means is converted into rotational energy. Conversion means;
Connecting / disconnecting means interposed between the energy converting means and the wheels of the vehicle, operating means for connecting / disconnecting the connecting / disconnecting means, and setting the energy converting means to any of the motor mode and the pump mode An energy conversion mode switching means for switching the energy conversion mode to a pump mode when the vehicle is braked and a motor mode when the vehicle starts or accelerates. In a braking energy regenerating device having controllable control means, the pressure of the working fluid in the working fluid storage means can be increased to a pressure lower than that of the pressure accumulating means and higher than the atmospheric pressure. A pressurizing means, a pressurized state in which the pressurizing force from the pressurizing means is supplied to the working fluid storing means, and a supply of the pressurizing force from the pressurizing means is cut off to open the working fluid storing portion to atmospheric pressure Pressurized state switching means capable of switching between an open state and a pressurized state switch means when the engine of the vehicle is in operation and the pressurized state switch means to be basically open when the engine is stopped. Pressurized state control means for performing control such that when the pressurized state control means detects that the rotation of the engine has stopped, the pressurized state switching means is maintained in the pressurized state for a predetermined time after the detection. It is characterized by having such a configuration.

Further, the pressurized state control means, after a lapse of the engine rotation stop after a predetermined time may be configured to switch the pressurizing state switching device in an open state, in this case
Sets the working fluid reservoir to atmospheric pressure after a predetermined time
be able to.

[0017]

In the braking energy regenerating apparatus according to the first aspect of the present invention, energy conversion is provided between the working fluid storing means for storing working fluid and the pressure accumulating means for accumulating fluid pressure energy. By pumping the means during braking and accumulating fluid pressure energy in the pressure accumulating means, the fluid pressure energy is converted into braking energy to increase the braking force of the vehicle.

At the time of starting acceleration, the fluid pressure energy stored in the pressure accumulating means is used as the starting acceleration energy by operating the energy conversion means by the motor. When the engine stall detecting means detects that the engine has been switched from the operating state to the stopped state without a stop operation, the control is performed so that the working fluid storing means is not opened to the atmosphere within a predetermined time.

Accordingly, the working fluid reservoir is maintained in a pressurized state for a predetermined time, so that when the engine is restarted within the predetermined time, useless operation of the engine can be prevented, and the driver can be prevented from operating. Very uncomfortable.
In the braking energy regeneration device according to the second aspect of the present invention, when the ignition key is turned on and the engine speed becomes zero, the engine stall detecting means detects the engine stall.

[0020]

[0021]

[0022]

[0023]

[0024]

[0025] In the braking energy recovery device of the present invention of claim 3, wherein the above mentioned through the disengaging means is disengaging driven by operating means, or is connected to the wheels of the energy conversion means and the vehicle is disconnected You.

On the other hand, the energy conversion means is switched between the motor mode and the pump mode by the operation of the energy conversion mode switching means. The operation of the energy conversion mode switching means is controlled by the control means.
That is, the control means controls the energy conversion mode switching means so that the energy conversion means is in the pump mode during braking of the vehicle, and the energy conversion mode is such that the energy conversion means is in the motor mode when the vehicle starts or accelerates. It controls the switching means.

Thus, when the energy conversion means is switched to the pump mode, the energy conversion means operates by receiving the rotational energy of the axle of the vehicle, and pressurizes the working fluid from the working fluid storage means to convert the working fluid into a hydraulic energy. And supply it to the pressure accumulating means. Then, in the pressure accumulating means, the working fluid is accumulated in a high pressure state. When the mode is switched to the motor mode, the fluid pressure energy stored in the pressure accumulating means is converted into rotational energy.

The pressure of the working fluid in the working fluid storage means is pressurized by the pressurizing means to a pressure lower than that of the pressure accumulating means and higher than the atmospheric pressure. The pressurized state switching means pressurizes the pressurizing means to apply the pressurizing force to the working fluid storage means, and cuts off the supply of the pressurizing force from the pressurizing means to open the working fluid storage part to atmospheric pressure. The open state is switched.

The pressurized state switching means is controlled by the pressurized state control means. When the engine of the vehicle is operating, the pressurized state switch means is controlled to the pressurized state, and when the engine is stopped, the pressurized state switch means is controlled. It is basically controlled to be in the open state. When the operation of the engine is stopped, the pressurized state control means keeps the pressurized state switching means in the pressurized state for a predetermined time from the stop of the operation.

Accordingly, the working fluid reservoir is maintained in a pressurized state for a predetermined time, so that when the engine is restarted within the predetermined time, useless operation of the engine can be prevented, and the driver can be prevented from operating. that eliminates the very discomfort.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 15 are diagrams for explaining a braking energy regenerating apparatus as a first embodiment of the present invention. FIG. 6 is a diagram for explaining a braking energy regeneration device according to a second embodiment of the present invention. Description of First Embodiment First, a first embodiment of the present invention will be described. FIG. 1 is a schematic diagram showing the overall configuration, FIG. 2 is a schematic block diagram showing the configuration of the control system, and FIG. 4 and 5 are flow charts for explaining a control procedure at the time of occurrence of the abnormality, and FIGS. 6 to 8 are flow charts for explaining the braking energy during the normal operation. Flowchart for explaining a control procedure in a pump mode for converting into hydraulic energy, FIGS.
2 is a flow chart for explaining a control procedure in a motor mode for converting fluid pressure energy into starting energy or acceleration energy during the normal operation, and FIG. 13 shows characteristics of signal values for determining the pump displacement of the pump / motor. FIG. 14 is a map showing characteristics of the accelerator opening discrimination value, and FIG. 15 is a map showing characteristics of signal values for determining the motor displacement of the pump / motor.

First, the overall configuration of the braking energy regeneration device will be described with reference to FIG. As shown in FIG. 1, in a vehicle provided with this braking energy regeneration device, an engine 1
Is input to the transmission 3 via the clutch 2. The output shaft 13 of the transmission 3 is connected to the drive shaft 10 via the differential 106. And this drive shaft 10
Thus, the drive wheels WR are driven.

The braking energy regenerating device includes a piston type accumulator 20 as a pressure accumulating means, a low-pressure hydraulic oil tank 30 as a working fluid reservoir, a swash plate type variable displacement axial piston type pump / motor 40 as an energy converting means, and a gear. A box 50, a control unit (hereinafter, referred to as ECU) 60 as control means, and the like are provided, and are connected to the above-described differential device 106 via a drive shaft 12 as a drive system member.

The accumulator 20 is connected to a first port 40a of the pump / motor 40 via a high-pressure oil passage P1, and a second port 40b of the pump / motor 40 is connected to a low-pressure hydraulic oil tank via a low-pressure oil passage P2. 30. The low-pressure hydraulic oil tank 30 is a tank that stores a hydraulic fluid (hydraulic oil) under a pressure lower than that of the accumulator 20 and at a pressure higher than the atmospheric pressure.

The accumulator 20 has a gas chamber 22 and a hydraulic oil chamber 2 formed by a piston 21 which can move inside.
The gas chamber 22 is filled with a gas of a predetermined pressure (for example, nitrogen gas or the like), and the working oil chamber 23 stores working oil as working fluid. In the high-pressure oil passage P1, a shutoff valve 24 and an unload valve (normally open) 25 are arranged in this order from the accumulator 20 side. The shut-off valve 24 is an electromagnetic pilot-operated valve, and is usually connected to the pump / motor 40 by the
It functions as a check valve that allows the flow of hydraulic oil toward the upstream and blocks the flow in the reverse direction. However, when a shut-off valve signal D2 from the ECU 60 is input to the shut-off valve 24, the pump from the accumulator 20 side receives / The flow of the working oil to the motor 40 side is allowed.

The electromagnetic unload valve 25 is connected to the ECU 60
When the unload valve signal D3 is input to the unload valve 25, the unload valve 25 is turned on, that is, the valve is closed. . Also, this unload valve 2
5 is to open the oil passage P3 that directly connects the high-pressure oil passage P1 and the low-pressure hydraulic oil tank 30 to release the residual pressure in the high-pressure oil passage P1 to the tank 30 when the valve is normally open. It has become.

Further, a discharge pressure sensor (operating fluid pressure detecting means) 89 for detecting the operating oil pressure on the pump / motor 40 side from the shut-off valve 24 is provided in the high-pressure oil passage P1. 89 functions as a working fluid pressure detecting means for detecting a working fluid pressure between the accumulator 20 and the pump / motor 40. The discharge pressure detected by the discharge pressure sensor 89 is
It is output to the ECU 60 as a discharge pressure signal PHY.

The accumulator 20 has a piston position sensor 87 for detecting the position of the piston 21 and outputting a piston position signal LP, and an accumulator 2.
A pressure accumulation sensor 88 that detects the oil pressure of the hydraulic oil within 0 and outputs a pressure accumulation signal PAC is provided, and the ECU 60 determines the accumulated pressure state in the accumulator 20 based on these two signals. .

The pump / motor 40 includes a gear box 50
Is connected to the drive shaft 12 through the drive shaft 12 so that the braking energy input from the drive wheels WR is transmitted to the drive shaft 12 and the gearbox 5.
0, the start / acceleration energy of the pump / motor 40 is conversely transmitted from the gearbox 50 via the drive shaft 12 and the differential 106 to the drive wheel W.
Is transmitted to R.

The gear box 50 includes a pair of gears 50a,
A pair of gears 50 a and 50 b is configured to increase the speed of rotation of the drive shaft 12 and transmit the rotation to the pump / motor 40. The connection between the drive shaft 12 and the pump / motor 40 is disconnected and connected by a dog clutch 51.

The pump / motor 40 is a swash plate type variable displacement axial piston type pump / motor as described above, and includes a drive shaft 40e connected to the output shaft of the gear box 50, and a plurality of shafts which rotate integrally with the drive shaft 40e. Cylinder 40f
And a piston 40c fitted into each of the cylinders 40f, and a piston 4c with the rotation of the drive shaft 40e.
The displacement of the pump / motor 40 is set by controlling the angle of the swash plate 40d with respect to the drive shaft 40e (hereinafter, this angle is referred to as the tilt angle). It has become so.

The tilt angle of the swash plate 40d is variably controlled by the operation of the tilt cylinder 41 shown in FIG. The tilting cylinder 41 includes a piston 41a directly connected to the swash plate 40d, and chambers 41b and 41c formed on both sides of the piston 41a. One of the chambers (for example, the chamber 41b) has a pilot (described later). When the pilot oil pressure is supplied from the oil pressure source 43,
The swash plate 40d is driven to the pump operation side, and the pump / motor 40 operates in the pump mode. Similarly, when the pilot pressure is supplied to the other chamber (chamber 41c), the swash plate 40d is driven to the motor operation side, and the pump / motor 40 operates in the motor mode.

The pilot hydraulic power source 43 is composed of an oil pump or a pressure regulating valve driven by an electric motor or the like.
A pilot pressure of a predetermined pressure is generated. A filter 4 is provided between the hydraulic pressure source 43 and the tilt cylinder 41.
5, an electromagnetic two-port switching valve 44 and a proportional electromagnetic valve 42 are provided, and these are configured as a pilot hydraulic control circuit for controlling the supply pressure of the pilot hydraulic pressure from the pilot hydraulic source 43 to the tilt cylinder 41. The proportional solenoid valve 42 is configured as an energy conversion mode switching means capable of switching the pump / motor 40 between the pump mode and the motor mode. The switching valve 44 operates in response to a drive signal D1 from the ECU 60 to control the pilot oil passage. Communication or interruption of P4 is performed.

When the control signal ELP is transmitted to one solenoid (for example, the solenoid 42a) of the proportional solenoid valve 42, the proportional solenoid valve 42 is driven at a duty ratio corresponding to the signal value ELP, and the pump of the tilt cylinder 41 is pumped. A pilot hydraulic pressure is supplied to the mode-side chamber 41b. Thereby, the piston 4 in the cylinder 41
1a is driven to variably control the tilt angle of the swash plate 40d. The control signal E is sent to the other solenoid 42b.
When the LM is transmitted, the proportional solenoid valve 42 is driven at a duty ratio corresponding to the signal value ELM, and the tilt cylinder 41
The pilot hydraulic pressure is supplied to the chamber 41c on the motor mode side.

Therefore, in the pump mode of the pump / motor 40, the swash plate 40d in the pump / motor 40
Is driven to the pump operation side by the tilting cylinder 41, the hydraulic oil is sucked up from the low-pressure hydraulic oil tank 30 by the pump / motor 40 via the filter 38, and is accumulated in the accumulator 20 via the oil passage P1. When the pump / motor 40 is in the motor mode, the pump / motor 40
The swash plate 40d is driven by the tilting cylinder 41 to the motor operation side, and the hydraulic oil is supplied from the accumulator 20 via the oil passage P1 to the pump / motor
Hydraulic oil that has flowed to zero and has been reduced in pressure by driving the motor 40 is stored in the low-pressure hydraulic oil tank 30 via the oil passage P2 and the filter 38.

The hydraulic oil tank 30 is connected to the pressurized air tank 31 through an electromagnetic two-port valve 33, a pressure reducing valve 35, and an air dryer 36, and is connected to a sub-oil through an electromagnetic three-port switching valve 34. The pressurized air tank 31 and the sub air tank 32 are configured as pressurizing means for the hydraulic oil tank 30, and the electromagnetic three-port switching valve 34 is configured as pressurized state switching means. .

The switching valve 34 receives a drive signal D from the ECU 60.
7 is transmitted to switch to a position where the sub air tank 32 and the hydraulic oil tank 30 communicate with each other. When the sub air tank 32 and the hydraulic oil tank 30 communicate with each other, the pressurized air partially retained in the sub air tank 32 flows into the hydraulic oil tank 30. In this way, the air in the hydraulic oil tank 30 is stabilized by replenishing or absorbing the air in the hydraulic oil tank 30 in accordance with the fluctuation of the hydraulic oil amount in the hydraulic oil tank 30.

On the other hand, when the drive signal D7 from the ECU 60 is cut off, the switching valve 34 is switched to the atmosphere open position,
The pressure in the hydraulic oil tank 30 is released to the atmosphere, and the pressure in the tank 30 is set to the atmospheric pressure. The switching valve 33 is operated by a drive signal D6 from the ECU 60, whereby the air tank 31 and the hydraulic oil tank 30 communicate with each other. And the air tank 31
When the hydraulic oil tank 30 communicates with the hydraulic oil tank 30, the high-pressure air stored in the air tank 31 is supplied into the hydraulic oil tank 30, the hydraulic oil in the tank 30 is pressurized to a predetermined pressure, and the operation of the pump / motor 40 is started. It is kept in a stable state.

The hydraulic oil leaking from the pump / motor 40 and the fitting portion (oil seal) in the hydraulic path is returned to the drain tank 39. Further, the drain tank 39 is provided with a reservoir tank 39A for storing surplus oil overflowing from the drain tank 39, and the reservoir tank 39A is provided with a reservoir tank switch 39B as a working fluid amount detecting means. This reservoir tank switch 39B is connected to the reservoir tank 3
This is a sensor for detecting the amount of oil in 9A, and notifies the ECU 60 when the amount of oil in the reservoir 39A becomes equal to or more than a predetermined value. The reservoir tank switch 39B is an on / off switch that is turned on when the amount of hydraulic oil in the reservoir tank 39A exceeds a predetermined value. However, the working fluid amount detecting means is not limited to such a reservoir tank switch 39B. Instead, a sensor such as an oil level sensor that can directly detect the volume of oil in the reservoir tank 39A may be used.

A pump 59 is connected to the reservoir tank 39A. And the reservoir tank 39
A is a pump 59 and an electromagnetic two-port switching valve 98A, 9A.
When the hydraulic oil in the reservoir tank 39A reaches a predetermined amount, the pump 59 and the switching valve 98A are driven to replenish the hydraulic oil tank 30 with the insufficient hydraulic oil. It has become.

The hydraulic oil tank 30 is provided with a hydraulic oil level sensor 90 and an oil temperature sensor 91, and these sensors 90 and 91 respectively provide a hydraulic oil level signal LOI.
L and the oil temperature signal TOIL are detected. Then, the ECU 60 determines whether the hydraulic oil is in a normal state based on the signals LOIL and TOIL,
By regulating the operating state of the regenerative device, damage to the device due to seizure of the pump / motor 40 or the like is prevented.

The dog clutch 51 is driven to be connected and disconnected by air pressure. The dog clutch 51 is connected to an air tank 52 in which high-pressure air is stored. Further, between the dog clutch 51 and the air tank 52, an electromagnetic three-port switching valve (dog clutch connecting valve) 53 for connecting (connecting) the clutch and an electromagnetic three-port switching valve (dog clutch closing valve) for disengaging (disconnecting) the clutch are provided. ) 54 is provided, and these switching valves 53 and 54 constitute operating means 55 for disconnecting and driving the dog clutch.

The switching valve 53 for connecting the clutch includes an ECU 60
A solenoid valve that operates when receiving a drive signal D8 from
When the switching valve 53 operates, the high-pressure air in the air tank 52 is supplied to the dog clutch 51, whereby the dog clutch 51 is controlled to a connected state. Further, the switching valve 54 for disengaging the clutch is an electromagnetic valve that operates when receiving the drive signal D9 from the ECU 60. When the switching valve 54 operates,
The dog clutch 51 is in a disengaged state.

The dog clutch 51 is provided with a dog clutch connection / disconnection sensor 92 for detecting the connection / disconnection state of the dog clutch 51 and transmitting a detection signal DCL to the ECU 60. The output shaft of the dog clutch 51 is provided with a rotation speed sensor 93 for detecting the rotation speed of the pump / motor 40.
Is transmitted to the ECU 60.

A brake pressure sensor 70 is connected to the ECU 60 so that a brake pressure PBK generated according to the amount of depression of the brake pedal 100 is detected. Then, the ECU 60 compares the magnitude of the discharge pressure signal PHY detected by the discharge pressure sensor 89 with the magnitude of the above-described brake pressure PBK with respective predetermined values, thereby accumulating pressure by the pump operation of the pump / motor 40. Operation switching control between power and a normal service brake is performed.

The engine 1 of this vehicle is a diesel engine, and the engine 1 has a fuel injection device 5. In the engine 1, normal fuel injection control is performed based on a control signal from an electronic governor control unit 67 connected to the fuel injection device 5, and fuel injection is performed in accordance with a rack limit signal R from the ECU 60 described later. Limit (rack limit)
Is performed.

The fuel injection limit (rack limit) is such that the sum of the output from the motor operation of the pump / motor 40 and the output from the engine 1 does not exceed the output corresponding to the maximum driving torque from the normal engine 1 alone. The output of the engine 1 is controlled. The governor control unit 67 also serves as an engine speed sensor for detecting the engine speed NE.
The output is output to U60, and therefore, the governor control unit 67 also functions as an engine speed sensor. The transmission 3 of this vehicle is a finger control type transmission, and includes a finger control transmission control unit (hereinafter, referred to as a finger control transmission unit).
3A). Here, the finger control transmission is a transmission device of a remote control type, in which an actuator (not shown) for changing the meshing state of the shift speed is provided in the transmission 3, and the actuator is controlled by, for example, an electric signal or the like. By doing so, the shift speed is changed. When there is a request from the driver to change the gear position (specifically, when the driver operates the shift lever), this T
The operation of the plurality of actuators is controlled by the CU 3A, so that the shift speed of the transmission 3 is controlled to a desired shift speed.

Then, in this transmission 3,
A vehicle speed sensor 83, a T / M reverse sensor 84, and a T / M neutral sensor 85 are provided, which respectively detect a vehicle speed signal V, a T / M reverse signal TMR, and a T / M neutral signal TMN, and detect these signals. The output is sent to the ECU 60. Next, the ECU 60 will be briefly described.
A processor, a memory, an input / output interface, and the like are provided. On the input side of the ECU 60, as shown in FIG.
The accelerator opening sensor 61, the engine clutch connection / disconnection sensor 62, and the various sensors described above (vehicle speed sensor 83, T
/ M reverse sensor 84, T / M neutral sensor 8
5, piston position sensor 87, pressure accumulation sensor 88, discharge pressure sensor 89, hydraulic oil level sensor 90, oil temperature sensor 9
1, dog clutch disconnection sensor 92, rotation speed sensor 93
Etc.) are connected.

Here, the main switch 64 detects a power ON / OFF state signal, and the diagnostic switch 65 reads out an error code when an error (abnormality) of the regenerative device or the like occurs, and according to the error code, will be described later. The command signal for blinking the diagnostic lamp 69 is output. The accelerator opening sensor 61 detects the depression amount (or accelerator opening) of the accelerator pedal 104 in conjunction with the accelerator pedal 104, and the engine clutch connection / disconnection sensor 62 operates in conjunction with the clutch pedal 105, This is for detecting the connection / disconnection state of the clutch (engine clutch) 2 between the engine 1 and the transmission 3. The clutch connection / disconnection sensor 62 can detect not only the determination of connection / disconnection of the clutch 2 (determination of ON or OFF) but also the half-clutch state.

Since the basic configuration of the present apparatus is as described above, during normal running, the ECU 60 is controlled so that the operating means 55 disengages the dog clutch 51. Therefore, the pump / motor 40 and the drive shaft 12 are separated from each other, and the pump / motor 40 does not operate. On the other hand, during braking of the vehicle, the dog clutch 51 is brought into contact with the ECU 60 through the operating means 55, and the energy conversion mode switching means 42 is controlled by the ECU 60.
Is set to the pump mode.

Thus, during braking of the vehicle, the pump / motor 40 acts as a pump, and the low-pressure hydraulic oil tank 3
Hydraulic oil within 0 is stored in the accumulator 20 under high pressure. The work of the pump causes the braking energy of the vehicle to accumulate as fluid pressure energy. At the time of starting / acceleration of the vehicle, the ECU 60 operates the energy conversion mode switching means 4 in a manner opposite to the above.
2 is controlled to set the pump / motor 40 to the motor mode.

Then, the pump / motor 40 operates as a motor by the high-pressure hydraulic oil stored in the accumulator 20, and the fluid pressure energy is converted into the starting / acceleration energy. Now, the overall configuration of the braking energy regenerating device of the present invention is as described above, but the main part of the device is configured as follows.

That is, in this device, the solenoid valve (switching valve)
The solenoid valves other than the solenoid valve 34 are turned off at the same time when the engine is stopped. However, only the switching valve 34 is stopped when the operating engine does not perform the stop operation. When a stall (stall) occurs, a predetermined time (for example, 60 seconds) after the stall
Is controlled to be ON so as to pressurize the inside of the low-pressure hydraulic oil tank 30 to a predetermined pressure.

In this case, if the amount of hydraulic oil in the reservoir tank 39A exceeds a predetermined amount, the switching valve 34 is switched OFF even within the above-mentioned predetermined time after the engine stalls.
The pressurized air in the low-pressure hydraulic oil tank 30 is discharged to the atmosphere, and the pressure in the tank 30 becomes atmospheric pressure. This takes into account that the engine 1 is often restarted immediately when the engine 1 is stopped by the engine stall. As described above, the switching valve 34 as the pressurized state switching means is stopped after the engine 1 is stopped. By maintaining the ON state for a predetermined time, the pressure in the low-pressure hydraulic oil tank 30 is maintained at a predetermined pressure during the predetermined time.

When the engine 1 is restarted within the predetermined time, the air in the low-pressure hydraulic oil tank 30 is increased to the predetermined pressure again because the air is not discharged from the low-pressure hydraulic oil tank 30. This eliminates the necessity, so that energy can be used efficiently. Also,
When the engine is stalled, the switching valve 34 is not turned off immediately. Therefore, if the engine 1 is restarted within the predetermined time, the air discharge sound (air escaping sound) generated from the switching valve 34 is not generated. As a result, the driver does not feel discomfort due to the air escaping sound.

When a predetermined time has elapsed after the engine stall, as shown in FIG. 2, a drive signal D7 is transmitted from the pressurized state control means 60D in the ECU 60 to the switching valve 34, and the switching valve 34 is moved to the atmosphere open position. The pressure is switched, and the pressure in the low-pressure hydraulic oil tank 30 becomes the atmospheric pressure. By the way, even if the pressurized state control means 60D determines that the oil level (oil amount) in the reservoir tank 39A has exceeded the predetermined value even before the predetermined time has elapsed since the engine stall, the switching valve 34 is turned off. Under control, the hydraulic oil tank 30 is opened to the atmospheric pressure.

When the engine 1 is stalled, the hydraulic oil in the hydraulic oil tank 30 flows into the drain tank 39 and the reservoir tank 39A via the pump / motor 40 by the action of air pressure, and the reservoir tank 39A This is because the hydraulic oil may overflow. That is, at the time of engine stall, the switching valve 3
Although all control systems other than the control in step 4 go down, the hydraulic oil in the hydraulic oil tank 30 is pressurized by the pressurized air tank 31 and the sub air tank 32. It flows toward the pump / motor 40 through the path P2. At this time, since the pump / motor 40 is not operating, the hydraulic oil that has reached the pump / motor 40 flows into the drain tank 39, and when the drain tank 39 is full, the hydraulic oil next flows into the reservoir tank 39A.

During normal engine operation, the pump /
Since the operation state of the motor 40 is controlled by the ECU 60, the operation oil does not flow from the operation oil tank 30 to the drain tank 39 via the pump / motor 40. Similarly, during normal operation of the engine, the pump 59 operates based on the detection information from the reservoir tank switch 39B provided in the reservoir tank 39A, so that the hydraulic oil in the reservoir tank 39A is returned to the hydraulic oil tank 30. It has become.

However, since the pump 59 does not operate at the time of engine stall, if the reservoir tank 39A becomes full of hydraulic oil by the action of pressurized air, the reservoir tank 39A will not operate.
It is conceivable that the hydraulic oil overflows from the engine and becomes insufficient during the next operation of the engine. Therefore, in the present invention, if the oil level (operating oil amount) of the reservoir tank 39A exceeds a predetermined value at the time of engine stall based on information from the reservoir tank switch 39B of the reservoir tank 39A, the predetermined time has not elapsed since the engine stall. Even in this case, by controlling the switching valve 34 by the pressurized state control means 60D, the pressurized air is discharged, and the outflow of hydraulic oil from the system is prevented.

As shown in FIG. 2, the ECU 60 also includes an abnormality determining means 60A, an excessive speed determining means 60B, and an abnormal time control means 60C in the ECU 60. Here, the abnormality determining means 60A determines, based on information from various sensors connected to the ECU 60, that an abnormality has occurred in the braking energy regeneration device.

When the abnormality is detected by the abnormality determining means 60A and the ECU 60 determines that the operation of the apparatus needs to be interrupted to protect the apparatus, the abnormality-time control means 60C causes the dog clutch 51 to operate. The disconnection control is executed. Thus, the operation of the device is interrupted. At this time, the abnormal time control means 6
At 0C, if it is determined based on information from the discharge pressure sensor 89 that the oil pressure between the accumulator 20 and the pump / motor 40 is equal to or less than a predetermined value, the operating means 55 causes the dog clutch 51 to disengage. It is controlled.

The reason why the hydraulic pressure information from the discharge pressure sensor 89 is monitored is that the dog clutch 51 is disconnected when the hydraulic pressure between the accumulator 20 and the pump / motor 40 is higher than a predetermined pressure. This is because if the drive system of the vehicle is disconnected, the high-pressure hydraulic oil rapidly applies a rotational driving force to the pump / motor 40 in a no-load state, and the pump / motor 40 may be damaged. .

Therefore, when the operation of the apparatus is interrupted due to the occurrence of an abnormality in the apparatus, the abnormality-time control means 6 in the ECU 60
At 0C, the accumulator 20 and the pump / motor 4
Oil pressure between 0 and a predetermined value (for example, 50 kg / cm ² )
When it is determined that the following conditions are satisfied, the drive signal D9 is set to the clutch disconnection switching valve 54 of the operating means 55, and the operating means 5
5 is a dog clutch 51 according to the control signal D9.
By disconnecting and driving, the operation of the entire apparatus can be interrupted while protecting the pump / motor 40.

By the way, if the discharge pressure sensor 89 fails when an abnormality occurs in the apparatus, the ECU 60 controls the oil pressure even though the oil pressure between the accumulator 20 and the pump / motor 40 is actually sufficiently reduced. It is conceivable that it is determined that the value is equal to or more than the predetermined value. In this case, even if an abnormality of the device is detected by the abnormality determining means 60A, the control signal D9 for disconnecting the dog clutch 51 is not set, and the braking energy regenerating device and the drive shaft 12 of the vehicle are maintained in a connected state. Instead, the protection of the device is hindered.

If the operating oil pressure does not drop below the predetermined value within a predetermined time (for example, 60 seconds) after the abnormality is detected by the abnormality determining means 60A, the discharge pressure sensor 89 fails. As a result, the abnormality-time control means 60C controls the operation means 55 so that the dog clutch 51 is disengaged. Next, the speed excess determining means 60B will be described.

The over-speed judging means 60B judges whether or not the speed of the vehicle is larger than a predetermined value based on the vehicle speed information V from the vehicle speed sensor 83. That is,
The speed excess judging means 60B compares the predetermined value V1 previously input to the memory unit of the ECU 60 with the vehicle speed information V from the vehicle speed sensor 83, and when the vehicle speed V is larger than the predetermined value V1, the vehicle speed is reduced to the predetermined value. It is determined that over (excess) has occurred.

When the speed excess determining means 60B determines that the speed V of the vehicle exceeds the predetermined value V1, the abnormal time controlling means 60C disconnects the dog clutch 51 and interrupts the operation of the device. I have. At this time, the abnormality-time control means 60C determines that the oil pressure between the accumulator 20 and the pump / motor 40 is equal to or less than a predetermined value based on information from the discharge pressure sensor 89, similarly to the abnormality detection described above. Then, the operating means 55 is controlled so as to bring the dog clutch 51 into the disconnected state.

If the operating oil pressure does not drop below the predetermined value within a predetermined time (for example, 60 seconds) after the vehicle speed excess judgment, the discharge pressure sensor 89 is considered to be malfunctioning and abnormal. The hour control means 60C is adapted to put the dog clutch 51 in a disconnected state. The reason why the dog clutch 51 is disengaged when the vehicle speed is determined to be excessive is to prevent damage due to excessive rotation of the pump / motor 40. That is, if the dog clutch is brought into the contact state in a region exceeding the allowable rotation speed of the pump / motor 40, the pump / motor 40 may be seized. If the vehicle speed exceeds a predetermined value, the dog clutch 51 is disconnected and the pump / motor 40 is disconnected. It is designed to protect 40.

On the other hand, on the output side of the ECU 60, in addition to the various electromagnetic switching valves described above, various indicators are connected. Indicators include a pressure accumulation indicator 66 for displaying the amount of accumulated pressure based on a piston position signal LP from a piston sensor 87 of the accumulator 20 and a pressure accumulation signal PAC from a pressure accumulation sensor 88, and a dog clutch connection / disconnection signal from a dog clutch connection / disconnection sensor 92. There are a regenerative lamp 68, a diagnostic lamp 69, and the like that indicate that the braking energy regenerating device is operating based on DCL.

The regenerative lamp 68 is turned on when the braking energy regenerating device is in the operating state, and turned off when the braking energy regenerating device is in the non-operating state, to inform the driver of the state of the braking energy regenerating device. In the ECU 60, an error code is determined based on a signal from the diagnostic switch 65, and the regenerative lamp 68 also outputs and displays the error code. The diagnostic lamp 69 is for notifying the driver of an abnormality of the engine 1 or the braking energy regenerating device. When the abnormality determining means 60A detects an abnormality of the device, the diagnostic lamp 69 is turned on to turn on the diagnostic lamp 69. To the driver. Further, in the ECU 60, a drive signal D9 for disengaging and operating the dog clutch 51 and a dog clutch connection / disconnection signal DC from the dog clutch connection / disconnection sensor 92 are provided.
When the matching with L is confirmed, the diagnostic lamp 69 is turned on when this matching cannot be confirmed, and informs the driver that the dog clutch 51 system is abnormal and the vehicle is difficult to travel.

Since the braking energy regenerating apparatus according to the first embodiment of the present invention is configured as described above, for example, when the engine is stalled, the exhaustion of unnecessary air is performed by executing the flowchart shown in FIG. In addition to the above, when an abnormality occurs in the braking energy regenerating device, the pump / motor 40 of the present device is protected by executing the flowcharts shown in FIGS.

Also, during normal operation of the apparatus, FIGS.
The regeneration operation of the braking energy is performed according to the flowchart shown in FIG. (A) Description of Normal (Normal) Control of Braking Energy Regenerating Apparatus First, before describing control of the braking energy regenerating apparatus during engine stall, operation of the braking energy regenerating apparatus during normal (normal) operation will be described. explain.

The normal operation of the braking energy regenerating device includes pump control (brake control) at the time of braking for accumulating the braking energy and converting it into fluid pressure energy, and converting the fluid pressure energy into kinetic energy for driving. There is a motor control at the time of driving to assist the force. First, the pump control shown in FIGS. 6 to 8 will be described. First, step S1
At 0, the ECU 60 determines whether the dog clutch 51 is ON (connected) or OFF (disconnected) based on the dog clutch connection / disconnection signal DCL from the dog clutch connection / disconnection sensor 92.

The result of determination in step S10 is OFF.
If it is (OFF), the process proceeds to step S20 in FIG.
Is set to zero (ELP = 0). As a result, the pilot oil pressure from the pilot oil pressure limit 43 is maintained in a disconnected state, and the piston 41a of the tilt angle cylinder 41 is also maintained at the neutral position. By maintaining the tilt angle of the swash plate 40d of the pump / motor 40 at zero, the pump / motor 40 does not function as a pump.

After executing step S20, the process proceeds to step S21. In this step S21, the switching valve 44
Is cut off, and the switching valve 44 is kept in the valve closed state. Next, proceeding to step S22, the output of the unload valve signal D3 to the unload valve (normally open) 25 is cut off. As a result, the unload valve 25 is controlled to be in the valve open state, and the high-pressure oil passage P1 and the low-pressure hydraulic oil tank 30 are kept in communication.

Next, the routine proceeds to step S23, where the ECU 60
Sets the flag f1 to 0 (f1 = 0), thereby storing that the pump control is not being performed. In addition,
When an abnormality of the regenerative device is detected during the operation of the pump and an abnormality occurrence control (error-time control) as described later is executed and the dog clutch 51 is disengaged, steps S20 and subsequent steps are executed by the judgment of step S10. And
The pump control will be stopped.

If it is determined in step S10 in FIG. 6 that the state is ON (connected), the process proceeds to step S11.
In step S11, the ECU 60 determines whether or not the transmission 3 is a reverse gear (reverse gear).
The determination is made based on the T / M reverse signal TMR. If the determination result is YES, that is, if the vehicle is in the reverse gear position, the above-described step S20 and subsequent steps in FIG. 8 are executed, and the pump is not controlled.

If the determination result is NO, that is, if the vehicle is in the forward gear position (including the neutral position), step S1 is executed.
Proceed to 2. In step S12, the ECU 60 determines whether the vehicle has stopped. This determination is made by comparing the vehicle speed signal V with a predetermined value XV0 (for example, XV0 = 1 km / h). If V ≦ XV0, it is determined that the vehicle is stopped, and the steps from step S20 are executed.
Pump control is not performed. On the other hand, if the determination result is V> XV0
If so, step S13 is executed.

In step S13, the ECU 60
Whether or not the driver is depressing the brake pedal 100 is determined based on the brake pressure signal PBK from the brake pressure sensor 70. And the brake pressure PBK <XPB
If (for example, XPB = 0.2 kgf / cm ² ), it is considered that the brake pedal 100 is not depressed, and the process proceeds to step S20, and the pump control is not performed. On the other hand, if the result of the determination is PBK ≧ XPB, it is determined that all the operating conditions for regenerating the energy have been satisfied, and step S
Step 14 is executed.

In step S14, the ECU 60
Tilt angle control signal value E of swash plate 40d of pump / motor 40
A subroutine for setting LP is executed. The pump displacement of the pump / motor 40 in the pump mode is determined by the signal value ELP. As a method of setting the ELP value, for example, a map as shown in FIG.
, A value corresponding to the brake pressure PBK is calculated, and this value is detected by the oil temperature TOIL detected by the oil temperature sensor 91 of the hydraulic oil tank 30, the vehicle speed V detected by the vehicle speed sensor, and the pressure accumulation sensor 88. Accumulator 2
It is conceivable that the value is appropriately corrected by the accumulated pressure amount PAC of 0 and set to an appropriate value.

Next, the process proceeds to step S15 shown in FIG. 7, in which a control signal corresponding to the signal value ELP set as described above is output to the proportional solenoid valve 42, and the pump / motor 40 The tilt angle is set to an angle corresponding to the signal value ELP, and thereafter, the process proceeds to step S16. In step S16, the drive signal D1 is output to the switching valve 44, the valve is controlled to open, and the pilot hydraulic pressure is supplied to the tilt cylinder 41. Next, proceeding to step S17, the unload valve (normally open) 25 between the high-pressure oil passage P1 and the low-pressure hydraulic oil tank 30 is controlled to be ON (valve closed state) by the unload valve signal D3, and the high-pressure oil passage P
The first pressure is shut off so as not to escape to the low-pressure hydraulic oil tank 30.

Further, in step S18, the flag f1 is set to 1 (f1 = 1) to store that the pump / motor 40 is operating in the pump mode. In this manner, when the tilt angle of the pump / motor 40 is set to an angle corresponding to the control signal value ELP to the proportional solenoid valve 42, the pump / motor 40 operates as a pump and the operation of the hydraulic oil tank 30 Oil is sucked and accumulated in the accumulator 20.

In the above pump control, the capacity of the pump / motor 40 is set in accordance with the amount of depression of the brake pedal 100 by the driver, whereby the pump / motor 40 responds to the amount of depression of the brake pedal 100. At work, braking energy will be regenerated. Next, motor control in the normal operation of the braking energy regenerating device will be described. FIGS. 9 to 12 are flowcharts showing control processing of motor control when the vehicle starts or accelerates (start / acceleration). This is an example.

First, before setting the pump / motor 40 to the motor mode, in steps S30 to S40, it is determined whether or not the motor control may be executed by the ECU 60. First, in step S30, the brake pressure signal PBK is compared with the predetermined pressure XPB to determine whether the driver intends to start the vehicle. Here, when the brake pressure PBK is equal to or higher than the predetermined pressure XPB,
If .gtoreq.XPB, it is determined that the brake pedal has been sufficiently depressed, and steps S50 and subsequent steps in FIG. 12, which will be described later, are executed, and control is performed so as not to perform motor control. If the result of the determination is PBK <XPB, the process proceeds to step S31.

In step S31, the ECU 60
It is determined whether the pump / motor 40 is operating in the pump mode. This is determined by determining the flag f1, and when the flag f1 = 1, it is determined that the pump / motor 40 is operating in the pump mode. Run,
Motor control is not performed. When the flag f1 = 0, it is determined that the mode is not the pump mode, and the flow goes through the NO route.
Proceed to step S32.

In step S32, whether the dog clutch connection / disconnection sensor 92 is ON (connected) or OFF (disconnected) is determined based on the dog clutch connection / disconnection signal DCL. If it is OFF (disconnected), the flow advances to step S50 in FIG. No motor control is performed. As described in the pump control, if an abnormality of the regenerative device is detected and the after-error control described below is executed and the dog clutch 51 is disconnected, step S
The motor control is not executed according to the judgment of 32.
On the other hand, if the determination result is ON (contact), then step S
Go to 33.

In step S33, it is determined whether or not the gear position of the transmission 3 is a reverse gear position (reverse).
/ M reverse signal TMR, and if the shift speed is a reverse gear (reverse), a YES
Proceeding to step S50 of No. 2, motor control is not executed. On the other hand, if the decision result is NO, then step S3
Proceed to 4.

Then, in step S34, it is determined whether the gear position of the transmission 3 is neutral or not.
The determination is made based on the M-neutral TMN. here,
If it is determined that the shift speed is neutral, it is determined that the driver does not intend to start the vehicle, and YES
The process proceeds to step S50 in FIG. 12 through the route, and the motor control is not performed. If it is determined that the shift speed is not neutral, the process proceeds to step S35.

In step S35, based on the clutch connection / disconnection signal CL1 of the clutch connection / disconnection sensor 62, the clutch 2
Is determined to be in a contact state or a disconnection state. And clutch 2
, The motor control is not performed as in the case where the transmission 3 is in the neutral state. On the other hand, if it is determined that the clutch 2 is in the engaged state (including the half-clutch state), the process proceeds to step S36 shown in FIG.

In step S36, it is determined whether or not the accumulator 20 is filled with hydraulic oil based on the piston position signal LP from the piston position sensor 87. When the piston position signal LP is OFF, it is determined that the operating oil is not accumulated in the accumulator 20, and in such a case, the process proceeds to step S50 in FIG. 12, and the motor control is not executed. When the piston position signal LP is ON, it is determined that hydraulic oil is accumulated in the accumulator 20, and the process proceeds to step S37.

In step S37, based on the vehicle speed signal V, it is determined whether the vehicle speed V is equal to or lower than a predetermined value XV2 (for example, 65 km / h). The vehicle speed V is higher than a predetermined value XV2 (V
If> XV2), it is determined that the allowable capacity of the pump / motor 40 has been exceeded, and the process proceeds to step S50 in FIG. 12 to prevent damage to the pump / motor 40, and the motor control is not executed. The vehicle speed V is equal to or less than a predetermined value XV2 (V ≦
If XV2), the process proceeds to step S38.

In step S38, similarly to step S37, the vehicle speed V is compared with a predetermined value XV1 (for example, 5 km / h). If the vehicle speed V is smaller than the predetermined value XV1 (V <XV1), the process proceeds to step S39. If the vehicle speed V is equal to or higher than the predetermined value XV1 (V ≧ XV1), the process proceeds to step S40. In step S39, it is determined based on the clutch connection / disconnection signal CL1 from the clutch connection / disconnection sensor 62 whether the clutch 2 is completely connected or a half clutch. Here, if it is determined in step S38 that the clutch 2 is completely connected in spite of the fact that the vehicle speed V is smaller than the predetermined value XV1, the clutch disconnection sensor 62 and the vehicle speed It is determined that there is some abnormality in the sensor 83 or the like, and the process proceeds to step S50 in FIG. 12, where control is performed so as not to perform motor control for safety. If the clutch connection / disconnection signal CL1 indicates a half-clutch state, the process proceeds to step S40.

In step S40, based on the accelerator opening signal Lθ from the accelerator opening sensor 61, it is determined whether or not the accelerator opening is larger than the discrimination value Xθ1. The above-described determination value Xθ1 is set according to the vehicle speed V, and is set according to a map as shown in FIG. If the accelerator opening Lθ is smaller than the discrimination value Xθ1 (that is, Lθ <Xθ1), the ECU 6
If it is 0, it is determined that the vehicle is not in a state to be accelerated, and the process proceeds to step S50 in FIG. 12, where the motor is controlled not to operate.

If the accelerator opening Lθ is larger than the discrimination value Xθ1 (that is, Lθ ≧ Xθ1), it is determined that all the driving conditions for assisting the driving force by the motor control are satisfied, and the routine proceeds to step S41. Start motor control. Here, the control when the motor control is not executed will be described.
At 50, the tilt angle control signal value ELM of the proportional solenoid valve 42
Is set to zero (ELM = 0) and output. As a result, the piston 41a of the cylinder 41 is held at the neutral position, and the swash plate type variable displacement axial piston pump /
Since the tilt angle of the swash plate 40d of the motor 40 becomes zero,
The pump / motor 40 does not function as a motor.

Next, at step S51, the drive signal D1 of the switching valve 44 for performing the supply / discharge control of the pilot hydraulic pressure is cut off by the ECU 60, and the valve is controlled to the closed state. Then, in step S52, the cutoff valve signal D2 is cut off to turn on the pump / motor 40 when the motor mode is activated.
The shut-off valve 24 (valve open state) is controlled to be OFF (valve closed state), and the pump / motor 4 from the accumulator 20 is turned off.
The flow of hydraulic oil to zero is shut off.

Next, in step S53, the output of the unload valve signal D3 is stopped and the unload valve 25 is turned off.
As the (valve open state), the high-pressure oil passage P1 and the low-pressure hydraulic oil tank 30 are communicated. In step S54, the rack limit signal R (which will be described later) that has been output to the engine 1 when the motor is operating is cut off. Also,
In step S55, similarly to the rack limit signal R, the rack limit enable signal RE output to the engine 1 is output.
Is cut off. Finally, in step S56, the flag f2 is set to 0.
(F2 = 0), which stores that the motor control is not being executed.

By the way, when the motor control is started by executing step S41 in FIG.
Tilt angle control signal value E of swash plate 40d of pump / motor 40
A subroutine for setting the LM is executed. Signal value EL
Explaining how to set M, an ELM map as shown in FIG. 15 is stored in the ECU 60 memory, for example, and based on this accelerator map, the accelerator opening Lθ and the vehicle speed V (instead of the vehicle speed V, the engine speed NE May be)
, The reference values (XM0, XM1,...) Are set.

Next, a correction coefficient K2 corresponding to the oil temperature of the hydraulic oil tank 30 detected by the oil temperature sensor 91 is obtained, and ELM
The reference value is corrected (ELM reference value × K2). Thus, the optimum tilt angle control signal value ELM is calculated. The tilt angle control signal value ELM is changed by the accelerator opening Lθ so that the response of the pump / motor 40 is obtained in the same manner as the response of the accelerator operation at the time of starting and accelerating only by the normal engine 1. This is for changing the output torque value due to the operation of the motor. Also, the vehicle speed V
By changing the tilt angle control signal value ELM depending on (or the engine speed NE), regenerative energy can be effectively used in a low-speed region such as starting.

The correction based on the oil temperature of the hydraulic oil tank 30 is not necessary when the oil temperature is lower than a predetermined value (for example, 70 ° C.). Therefore, since the viscosity of the pump / motor 40 may decrease and the pump / motor 40 may be burned, it is necessary to reduce the motor capacity to prevent this. For this reason, the signal value ELM is corrected so as to decrease.

Next, in step S42 of FIG.
The signal value ELM set as described above is output to the proportional solenoid valve 42, and in step S43, the drive signal D1 is output, the switching valve 44 is turned on (valve open state), and The pilot hydraulic pressure is supplied to the cylinder. As a result, the swash plate 40d of the swash plate type variable displacement axial piston pump / motor 40 changes the signal value ELM.
Is set to a tilt angle corresponding to. Next, step S44
Then, the shutoff valve signal D2 is output to the shutoff valve 26, the shutoff valve 26 is turned ON (valve open state), and in step S45, the unload valve signal D3 is output to the unload valve (normally open) 25. The pressure is controlled to ON (valve closed state), and the pressure in the high-pressure oil passage P1 is shut off so as not to escape.

Thus, the high-pressure hydraulic oil stored in the accumulator 20 flows into the pump / motor 40, and the pump / motor 40 is driven as a motor. And the driving force is the driving shaft 40e, the gearbox 5
0, transmitted to the drive wheels WR via the drive shafts 12 and 10,
The driving force at the time of starting or accelerating is assisted. In step S46, a rack restriction signal R for restricting fuel supply to the fuel injection device 5 of the engine 1 is supplied to the fuel injection device 5 via the governor control unit 67. The rack limit signal R limits the output torque of the engine 1 during motor control. The output limit of the engine 1 is determined based on the engine speed NE and the accumulated pressure PAC of the accumulator 20. .

Then, in order to surely execute the output restriction on the engine 1 side supplied to the fuel injection device 5, in step S47, a rack restriction valid signal RE is output to the governor control unit 67, and an error due to noise or the like is generated. It prevents operation. Thereafter, step S48
Sets the flag f2 to 1 (f2 = 1), thereby storing that the pump / motor 40 is operating in the motor mode. (B) Description of Control during Stall of Engine of Braking Energy Regeneration Apparatus Next, pressure control in the low-pressure hydraulic oil tank during engine stall as a main part of the present invention will be described.
In this case, control is performed according to the flowchart shown in FIG.

The pressurized state switching means 60D of the ECU 60 includes:
By executing this control flow, a stall of the engine 1 is detected and a process at the time of engine stall is performed. In the following, a description will be given with reference to the flowchart shown in FIG. 3. First, in a routine for setting initial values, two flags FA and FB are each initialized, and FA is set.
After setting = 0 and FB = 0 (not shown), the flow advances to step SA2 to determine whether the ignition key is ON or OFF.

Here, if the ignition key is ON, the flow proceeds to step SA1 and below, and if the ignition key is OFF, the flow proceeds to step SA19. First, the case where the ignition key is OFF will be described.
It is determined whether the solenoid valve (switching valve) 34 is OFF. When the solenoid valve (switching valve) 34 is OFF, the process returns as it is. When the switching valve 34 is ON, the process proceeds to step SA20 to turn it off.
And returns after exhausting the air in the hydraulic oil tank 30. That is, if it is determined in step SA2 that the ignition key is OFF, the operation returns with the air in the low-pressure hydraulic oil tank 30 being exhausted.

Next, if it is determined in step SA2 that the ignition key is ON, the process proceeds to step S2.
Proceeding to A3, it is determined whether the engine 1 is rotating.
The rotation state of the engine 1 is determined based on information detected by the engine speed sensor 67. And
When the engine 1 is not rotating, the process proceeds to step SA4, and when the engine 1 is rotating, the process proceeds to step SA6.

Here, the case where the engine 1 is not rotating will be described first. In step SA4, it is determined whether or not the flag FA = 1. In this case, since the value of the flag FA has not been updated since the flag FA was set to 0 in step SA1, the process proceeds to step SA5 via the NO route. Then, in step SA5, the solenoid valve (switching valve) 34 is controlled to be turned off, and the hydraulic oil tank 3
The air in 0 is discharged. And after this, it returns.

On the other hand, when the ignition key is operated to start the engine 1, the rotation of the engine 1 is detected in step SA3, and the process proceeds to step SA6. In step SA6, the value of the flag FA is updated to 1 (FA = 1).
Then, the flow advances to step SA7 to determine whether or not the flag FB = 1. In this case (immediately after starting the engine 1), since the flag FB is still 0 (step SA1), the process proceeds to step SA10.

In step SA10, drive signals D6 and D7 are set for the solenoid valves (switching valves) 33 and 34, and the switching valves 33 and 34 are controlled to be ON. As a result, air is supplied from the air tanks 31 and 32 to the low-pressure hydraulic oil tank 30, and the low-pressure hydraulic oil tank 30 is supplied with air.
Is pressurized. And this step SA10
Next returns.

Note that these steps SA6, 7, and 10 are as follows:
Pressurization of the tank 30 is started when the engine 1 is started, and the control is the same as the conventional one. Step S
The case where the flag FB = 1 in A7 will be described later. As described above, during normal engine rotation, steps SA3 to SA3,6,6 in the flowchart shown in FIG.
The routine returns through steps 7 and 10. By executing this routine, the low-pressure hydraulic oil tank 30 is pressurized.

If the engine 1 stalls while the engine 1 is operating normally, the process proceeds to step SA4 after step SA3. In step SA4, it is determined whether or not the flag FA is 1. In this case, since the engine 1 was rotating until immediately before, the flag FA was set to 1 (step S4).
A6), and the process advances to step SA11 through the YES route.

At step SA11, it is determined whether or not the flag FB = 1. When the process proceeds to step SA11 for the first time, the flag FB is not updated before this.
Through the O route, the process proceeds to step SA12, where the flag FB = 1 is set. When the flag FB is set to 1 in step SA12, the process proceeds to step SA13 to start counting by the timer.

Thereafter, the flow advances to step SA14 to determine whether or not the time T ₀ that has elapsed since the start of counting of the timer has elapsed by a predetermined time T (for example, T = 60 sec). In step SA14, the predetermined time has not elapsed since the timer started counting (T ₀ <
If T) is determined, the flow advances to step SA15 to determine whether the reservoir tank switch 39B is ON. If the reservoir tank switch 39B is OFF, it is determined that the amount of hydraulic oil stored in the reservoir tank 39A is equal to or less than a predetermined amount, and the routine returns.

Then, in the subsequent control cycles, unless the ignition key is turned off or the engine 1 is restarted, the process proceeds from step SA2 to steps SA3, SA4, SA11, and step SA11.
The process then proceeds to step SA14 through the S route. That is, in step SA11, it is determined whether or not the flag FB = 1, but in the control cycle before this, the flag FB is determined.
Since = 1 is set (step SA12), the process proceeds to step SA14. Therefore, the control cycle for the second and subsequent times after the engine stall is T ≧ T ≧ at step SA14.
Until determined to be 60, or reservoir tank switch 3
Until 9B is turned on, steps SA2 to 4, 11, and
It will pass through routes 14 and 15.

If it is determined in step SA14 that the time T ₀ elapsed since the start of counting of the timer has passed a predetermined time (T ₀ ≧ T), the process proceeds to step SA16, where the solenoid valve (switching) is performed. The valve (34) is turned off, and the air in the hydraulic oil tank 30 is discharged. Then, the process proceeds to step SA17 to stop the timer and reset the timer. Then, the process proceeds to step SA18, where FA = 0, F
B = 0 is set, the flag is reset, and the routine returns.

Thus, if the engine 1 is not restarted within a predetermined time after the engine stall, it is determined that the driver does not intend to restart the engine 1, the hydraulic oil tank 30 is opened to the atmosphere, and the normal engine 1 Is stopped. Even if it is determined in step SA14 that the predetermined time has not elapsed from the start of counting by the timer, if the reservoir tank switch 39B is turned on in step SA15, the process also proceeds to step SA16 and the subsequent steps. The air in the oil tank 30 is discharged.

This is because the hydraulic oil flows to the drain tank 39 via the pump / motor 40 by the action of the air pressure in the hydraulic oil tank 30, and furthermore, this drain tank 39
This is to prevent the hydraulic oil flowing out of the reservoir tank 39B from overflowing (see FIG. 1). By the way, if the engine 1 is started again before the predetermined time elapses or before the reservoir tank switch 39B is turned on, the process proceeds from step SA3 to step SA6 and step SA7. Then, in step SA7,
It is determined whether the flag FB is "1".

The value of the flag FB is set when the engine is stalled.
Since it is set to 1 in step SA12, the process proceeds to step SA8 via the YES route. Then, in step SA8, the timer is stopped and reset, and thereafter, in step SA9, the flag FB is set to "0", and the routine returns. Since the pressure control in the low-pressure hydraulic oil tank 30 during the engine stall is performed as described above, the switching valve 34 is kept ON for a predetermined time during the engine stall, and the pressure in the hydraulic oil tank 30 is maintained at the predetermined pressure. Is done. Therefore, since the air discharge sound is not generated during the predetermined time, the driver does not feel uncomfortable.

Further, after the engine stalls, the air in the low-pressure hydraulic oil tank 30 is not discharged for a predetermined time and the low-pressure hydraulic oil tank 3
By maintaining the inside pressure at 0 at a predetermined pressure, it is not necessary to increase the pressure in the tank 30 again when the engine 1 is restarted within the predetermined time, and there is also an advantage that unnecessary energy consumption can be eliminated. . Furthermore, after stalling,
Even before the predetermined time has elapsed, the reservoir tank 39
When the hydraulic oil of A becomes equal to or more than a predetermined amount, the air in the hydraulic oil tank 30 is exhausted, so that the reversible tank 3 of the hydraulic oil is discharged.
There is also an advantage that outflow from 9A can be prevented.

According to such a configuration, it is not necessary to add a special structure, a new sensor, and the like, and the present apparatus can be realized only by adding control software. There is almost no. When the reservoir tank 39A is not provided, the drain tank 39A is not provided.
A is configured to detect the amount of hydraulic oil from an oil level sensor (not shown) of A, and when the amount of hydraulic oil in the drain tank 39A becomes equal to or more than a predetermined amount based on the detection information from the oil level sensor, The air in the low-pressure hydraulic oil tank 30 may be discharged. (C) Control when the braking energy regenerating device is abnormal And finally, when controlling when the braking energy regenerating device is abnormal, FIGS. 4 and 5 show control procedures when the braking energy regenerating device is abnormal. It is an example of a flowchart. The ECU 60 repeatedly executes this control flow at a predetermined cycle, monitors for abnormalities (errors) in the device,
Performs processing when an error occurs.

First, the ECU 60 sets the flags F1 and F2 to 0 (F1 = 0, F2 =
Set to 0). Then, in step S70, it is determined whether an abnormality (error) has occurred in the braking energy regeneration device. The ECU 60 executes a program for constantly monitoring abnormalities and failures of valves such as the above-mentioned shut-off valve 24 and relief valve 26 and sensors such as the discharge pressure sensor 89 and the oil temperature sensor 91. When an abnormality is detected in various valves and sensors in the above, an error signal (error code) corresponding to this error is output. Therefore, whether or not an abnormality has occurred in the braking energy regeneration device is determined by the presence or absence of the output of the error signal in the abnormality determination means 60A, and if it is determined that there is no abnormality in the device, the process proceeds to step S70A.

Then, in this step S70A, it is determined by the excess speed determining means 60B whether or not the speed of the vehicle exceeds a predetermined value. As a result, if it is determined that the vehicle has not exceeded the predetermined speed, the process proceeds to step S
Proceed to 85. Steps S85 to S88 show a processing route when the apparatus is in a normal state with no abnormality. That is, in step S85, the diagnostic lamp 69 is controlled to be turned off (turned off) (or kept in the OFF state). Next, the process proceeds to step S86, where the dog clutch 51 is turned on (connected) or turned off (disconnected) based on the dog clutch connection / disconnection signal DCL from the dog clutch connection / disconnection sensor 92.
Is determined. If the determination result is OFF (disconnected), the regenerative lamp 68 is turned off in step S88 to clearly indicate that the apparatus is in an inoperative state.
(Off). If the determination result is ON (contact), the process proceeds from step S86 to step S87, where the regenerative lamp 68 is turned ON (lit) to display that the apparatus is operating.

On the other hand, the control (abnormality occurrence control) when it is determined in step S70 that there is an error or in step S70A that it is determined that the vehicle speed is over will be described.
First, when it is determined in step S70 that an error has occurred, the process proceeds to step S71 to store the error code output to the ECU 60. The error code is a signal corresponding to the error that has occurred, and this clarifies which part of the error occurred. The ECU 60
The error code stored in is stored in step S in FIG.
The signal is output by blinking the regenerative lamp 68 at 79 and is used when repairing a part where an abnormality has occurred. Then, the control from step S72 is performed.

Even if it is determined in step S70 that there is no error, the next step S70A
If it is determined that the vehicle speed is exceeding in step, the process proceeds to step S70B. Then, in step S70B, the display of the vehicle speed excess is performed, and the process proceeds to step S72. In step S72, all controls are turned off in order to prevent damage to the braking energy regeneration device due to occurrence of an abnormality.
(Stop). That is, specifically, the switching valve 44
The drive signal D1 is cut off to cut off the pilot oil passage P4, or the drive signals ELP and ELM of the solenoids 42a and 42b of the proportional solenoid valve 42 are cut off to set the swash plate tilt angle of the pump / motor 40 to zero.

Then, the dog clutch valve 54 is turned off
N, the dog clutch 51 is disconnected, and the operation of the pump / motor 40 is interrupted, whereby the operation of the energy regenerating device can be completely stopped. However, the dog clutch 51 is immediately stopped after the process of step S72. If the 51 is disconnected, it is possible that the pump / motor 40 is adversely affected.

That is, if there is a residual pressure of hydraulic oil between the accumulator 20 and the pump / motor 40 when the dog clutch 51 is disengaged, the residual pressure causes the pump / motor 40 in a no-load state to be forcibly driven. In some cases, the pump / motor 40 is driven (overrun) beyond the allowable rotation speed of the pump / motor 40, and the pump / motor 40 may be damaged.

Therefore, in the present apparatus, after the processing of step S72, the processing of steps S72A to S72L is performed by the abnormal time control means 60C, and then the dog clutch 5
1 is executed. That is, after step S72, the process proceeds to step S72A, and based on the discharge pressure information from the discharge pressure sensor 89, the residual pressure PHY of the hydraulic oil between the accumulator 20 and the pump / motor 40 becomes equal to the predetermined pressure P1 (for example, P1 = 50 kgf / cm ² ) is determined. If the residual pressure PHY is smaller than the predetermined value P1 (PHY <P1), it is determined that the residual pressure PHY has no effect on the pump / motor 40, and the processes of steps S72J to S72L are performed. Then, the process proceeds to step S73 to output a drive signal D9 to the dog clutch valve 54. As a result, the dog clutch valve disconnection 5
4 is controlled to ON, and the dog clutch 51 is disengaged.

Steps S72J to S72L are controls for resetting the timer T1, which is to be described later, after the timer T1 has been started, after stopping the counting, which will be described later. On the other hand, if the residual pressure PHY is equal to or greater than the predetermined value P1 (PHY≥P1), the process proceeds to step S72B via the NO route and the flag F1 is set to 1
It is determined whether or not. In the first control cycle, the flag F1 is set to 0 by setting the initial conditions (F1 = 0, F2 = 0).
The process proceeds to 2C, where the flag F1 is set to 1 (F1 = 1). If it is determined in step S72B that F1 = 1 after the next control cycle, the process proceeds to step S72E. If F1 = 1 is set in step S72C, the process proceeds to step S72D, where the timer T1 starts counting, and then proceeds to step S72E. After this,
The timer T1 continues counting until a count stop command is issued.

In step S72E, the ECU 6
If it is 0, it is determined whether or not the count value of the timer T1 has passed a predetermined time T '(for example, T' = 60 sec). If the count value T1 of the timer is less than the predetermined time T ', the process returns through the NO route. in this case,
If the residual pressure information PHY from the discharge pressure sensor 89 becomes smaller than the predetermined value P1, and the YES route is passed in step S72A,
Alternatively, the disconnection control of the dog clutch 51 in step S73 is not performed until the predetermined time T 'has elapsed from the start of the timer count.

In step S72E, the timer T
If it is determined that the predetermined time T 'has elapsed from the start of the counting of 1, the process proceeds to step S72F. Then, in step S72F, it is determined that an error has occurred in the discharge pressure sensor 89, and this message is displayed. Next, step S72G
To stop the timer T1 and
Is reset, the flag F1 is set to 0 in step S72H, and the flow advances to step S73 to perform a process of disconnecting the dog clutch 51.

Here, even if the residual pressure PHY between the accumulator 20 and the pump / motor 40 is equal to or higher than the predetermined pressure P1, the dog clutch 51 is disconnected after the predetermined time T 'has elapsed, and the error of the discharge pressure sensor 89 is detected. It is determined for the following reason. That is, even if the residual pressure PHY is detected as a large value after the various control valves are turned off in step S72, the residual pressure PHY generally gradually decreases,
After a lapse of the predetermined time T ', the residual pressure PHY should have become sufficiently small. Therefore, if the residual pressure PHY does not fall below the predetermined pressure P1 even after the predetermined time T 'has elapsed, it is determined that the discharge pressure sensor 89 has failed, and the dog clutch disconnection valve 54 is controlled to be ON by the ECU 60. As a result, the dog clutch 51 is disconnected. In other words, in this case, despite the fact that the residual pressure PHY is sufficiently reduced,
It is determined that the discharge pressure sensor 89 has failed and cannot be detected.

If it is determined in step S72A that the residual pressure PHY is smaller than the predetermined pressure P1, the process proceeds to step S72.
After the control of 72J to S72L is performed, the flow proceeds to step S73, and the disconnection control of the dog clutch 51 is performed.
Here, steps S72J to S72L will be described. First, in step S72J, it is determined whether or not the flag F1 = 1. If it is determined that F1 = 1, it can be determined that the processing control of steps S72C and S72D has been executed before step S72J, and the count of the timer T1 is continued. Therefore, if it is determined in step S72J that F1 = 1, then the process proceeds to step S72K, where the timer T1 is set.
Is stopped and then reset, and then step S7
After the flag F1 is set to 0 (F1 = 0) at 2L, the process proceeds to step S73, and the disconnection control of the dog clutch 51 is performed.

In step S72, the flag F1 is set to 1
If not, it is determined that the flag F1 is still in the initial condition (that is, F1 = 0) and the counting of the timer T1 has not been started, and the process directly proceeds to step S73. As described above, in the present braking energy regenerating apparatus, when an abnormality occurs in the apparatus or when the vehicle speed is exceeded, step S72 is performed.
By executing the processing from A to step S72L, it is possible to prevent the pump / motor 40 from overrun due to the residual pressure PHY when the dog clutch 51 is disconnected, and to protect the pump / motor 40 from seizure or damage. You can do it.

Next, control after step S73 shown in FIG. 5 will be described. In step S73, the dog clutch disconnection valve 54 is controlled to be ON to perform the disconnection control of the dog clutch 51, and then the process proceeds to step S74. Step S74
Then, based on the drive signal D9 output to the dog clutch valve 54, it is determined whether or not the dog clutch 51 is actually disengaged. This determination is made based on the dog clutch connection / disconnection sensor 92.
The comparison is performed by comparing the detection signal DCL from the drive signal D9 with the drive signal D9.

When the clutch connection / disconnection signal DCL is OFF (disconnected), that is, the dog clutch 51 is disengaged according to the drive signal D9 (matching the drive signal D9).
In this case, the process proceeds to step S74A. Step S74
In the above, when it is determined that the dog clutch 51 is in the connected state even though the drive signal D9 is output to the dog clutch disconnection valve 54, the matching between the clutch disconnection signal DCL and the drive signal D9 cannot be confirmed. In this case, the process proceeds to step S74D. Then, the timer is operated between steps S74D to S90, and it is confirmed whether or not the clutch connection / disconnection signal DCL matches the drive signal D9 during the predetermined time T ″.

The confirmation operation will be described first.
Proceeding to step S74D, it is determined whether the flag F2 is "1". Here, if it is determined that the flag F2 is not 1, the process proceeds to the step S74E via the NO route, the flag is set to F2 = 1, and then the counting of the timer T2 is started. Then, the process proceeds to step S90 to determine whether the count of the timer T2 has exceeded a predetermined value T ". If it is determined in step S74D that the flag F2 = 1, it is determined that the timer T2 is counting. Then, the process proceeds to a step S90, and it is determined whether or not the count of the timer T2 exceeds a predetermined value T ″.

In step S90, the detection signal DCL from the dog clutch connection / disconnection sensor 92 is turned on in step S74.
Even if it is determined to be (connection), the dog clutch 5
It is determined whether or not the connection state has continued for a predetermined time T ″ (for example, T ″ = 10 sec) without determining that the abnormality is No. 1. Here, the waiting for the predetermined time is performed in consideration of the case where the dog clutch valve 54 is activated and the dog clutch 51 is disengaged within the predetermined time.

If it is determined in step S90 that the predetermined time T ″ has not elapsed since the start of the timer count, the process returns through the NO route, and the dog clutch connection / disconnection signal DCL is confirmed again in the subsequent control cycle. At this time, when it is determined that the dog clutch 51 is in the contact state, the process proceeds from step S74D to step S90, and thereafter, until the dog clutch 51 is determined to be in the disconnected state within the predetermined time T ″ or until the predetermined time T ″ elapses. , This routine is repeated, and the diagnosis lamp control and the disconnection control of the dog clutch 51 are not performed.

If the count of the timer T2 exceeds the predetermined value T "in step S90 (that is, if the dog clutch 51 is not disengaged even after the predetermined time T" has elapsed), YES is determined.
The flow proceeds to step S90A via the route, and in this step S90A, the count of the timer T2 is stopped and reset. After that, the flow proceeds to step S90B to set the flag F2 to 0. The first error that occurs is the dog clutch 5
1 or that occurred at a location related to the dog clutch 51, and the routine proceeds to step S91, where the diagnosis lamp 6
9 is turned on to notify the driver that the vehicle should be stopped.

As a result, safety can be ensured by stopping the vehicle by the driver, quick repairs can be taken, and protection of the braking energy regeneration device can be achieved. Then, in step S92, the output of the driving signal D9 for the dog clutch valve 54 is cut off, and the process proceeds to step S77. Next, in step S74 described above, the detection signal DCL from the dog clutch disconnection sensor 92 is output.
A description will be given of a process in a case where the matching between the dog clutch 54 and the drive signal D9 of the dog clutch valve 54 can be confirmed. In this case, it is determined that the dog clutch 51 operates normally.
In this state, the braking energy regenerating device is disconnected from the drive shaft 12 of the vehicle, and the vehicle can run with the driving force from the engine 1. If it is determined in step S74 that the dog clutch 51 has been disengaged, the process proceeds to step S74A.

In step S74A, it is determined whether flag F2 is 0. Here, when F2 is not 0 (that is, when F2 = 1), step S7 is executed until immediately before that.
4D to S90 are executed, and the dog clutch 51 is disengaged before a predetermined time T "elapses from the start of counting of the timer T2. Therefore, if the flag F2 is not 0 in step S74A, ,
The process proceeds to step S74B via the NO route and proceeds to timer T.
After stopping the counting of 2 and resetting it, the process proceeds to step S74C to set the flag F2 to 0 (F2 = 0). Thereafter, the process proceeds to step S75. If it is determined in step S74A that the flag F2 is 0, the flow advances to step S75 via the YES route.

In step S75, since the dog clutch 51 is normally disengaged, the diagnostic lamp 69 is turned off (turned off), and no failure is displayed. As described above, even when an abnormality occurs in the regenerative device, the diagnostic lamp 69 does not light up, so that the driver can continue normal driving without erroneously determining that the vehicle cannot be driven. .

Then, the process proceeds to step S76, where the disconnection of the dog clutch 51 has already been confirmed, and the output of the drive signal D9 to the dog clutch valve 54 is turned off.
FF is set, and then the process proceeds to step S77. Due to its structure, the dog clutch 51 can maintain its state once the connection operation or the disconnection operation is completed even if the driving force for driving the clutch connection / disconnection is cut off.

In the step S77, the regeneration lamp 68 is turned on.
FF (turn off) to notify the driver of the inoperative state of the regenerative device. Also, when the diagnosis lamp 69 is turned on by executing the above-described step S91, this step S77 is executed and the regenerative lamp 68 is turned off (turned off).
Is set to From step S78, the procedure for reading out the error code stored in step S71 when the maintenance worker performs repair or inspection is described. First, in step S78, it is determined whether or not the operator has operated the diagnostic SW 65 to read the error code (that is, whether the diagnostic SW 65
(W65 is turned ON). Then, when it is detected that the diagnostic SW 65 is operated to the ON side,
Next, the process proceeds to a step S79 to output an error code stored in the memory of the ECU 60. Also, Diag SW6
If 5 is not operated to the ON side, nothing is performed and this control is terminated.

In step S79, in response to the read error code, the regenerative lamp 68 is made to blink like a Morse code, for example, and the operator knows the cause of the failure by the blinking pattern of the regenerative lamp 68. be able to. Description of Second Embodiment Next, a second embodiment of the present invention will be described. FIG. 16 is a flowchart for explaining a control procedure when the engine is stopped in the braking energy regenerating device as the second embodiment of the present invention. is there.

In the second embodiment, the braking energy regenerating apparatus has the same configuration as that of the first embodiment, and differs from the first embodiment only in the control software. That is, in the first embodiment, the air in the low-pressure hydraulic oil tank 30 is not discharged for a predetermined period of time only when the engine 1 is stalled. Thus, the inside of the low-pressure hydraulic oil tank 30 is maintained at a predetermined pressure without discharging the air in the low-pressure hydraulic oil tank 30 within a predetermined time after the engine operation is stopped by the ignition key.

Therefore, after the engine is stopped by operating the ignition key, the air in the hydraulic oil tank 30 is not discharged for a predetermined time, so that the hydraulic oil tank 30 is pressurized when restarting immediately. This eliminates the need and saves energy. The braking energy regenerating apparatus according to the second embodiment of the present invention is configured as described above.
The control operation is performed according to the flowchart shown in FIG.

The flowchart shown in FIG. 16 is different from the flowchart of FIG. 3 in that steps SA19 and SA20 are deleted, and steps SA4 and SA5 are replaced by steps similar to steps SA4 and SA5 (step S18).
A30-39, see FIG. 16). Thus, when control is performed according to the flowchart shown in FIG. 16, in step SA2, the ignition key OF
In the case of F, the process proceeds to step SA30 and subsequent steps,
According to 30 to 39, the air in the hydraulic oil tank 30 is not discharged within a predetermined time.

Therefore, the same effects as those of the first embodiment can be obtained. In addition, after the engine is stopped by operating the ignition key, the air in the hydraulic oil tank 30 is not discharged for a predetermined time, so that the engine is immediately restarted. In this case, it is not necessary to pressurize the hydraulic oil tank 30 and energy can be saved. Note that the flowchart shown in FIG. 16 is the same as the flowchart shown in FIG.

Further, in the first and second embodiments described above, the vehicle in which the engine is a diesel engine has been described. However, the vehicle applied to the present apparatus is not limited to this, and may be a gasoline engine. And other vehicles equipped with an engine. Also,
Similarly, for the transmission 3, the first
The present invention is not limited to the finger control transmission as in the second embodiment.

[0160]

As described above in detail, according to the braking energy regenerating device of the first aspect of the present invention, between the working fluid storing means for storing the working fluid and the pressure accumulating means for accumulating the fluid pressure energy. The energy converting means interposed in the fluid passage and connected to the driving system member of the vehicle via the disconnecting / connecting means is operated by a pump at the time of braking to accumulate the fluid pressure energy in the pressure accumulating means, thereby reducing the fluid pressure energy to the braking energy. On the other hand, at the time of starting acceleration, the motor is operated and the fluid pressure energy stored in the pressure accumulating means is used as the starting acceleration energy,
A braking energy regenerating device that basically releases the working fluid storing means to the atmosphere when the engine is stopped; and an engine stall detecting means for detecting an engine stall that switches from an operating state to a stopped state without a stop operation. When the stall detecting means detects that the engine has been switched from the operating state to the stopped state, the working fluid storage means is controlled so as not to be opened to the atmosphere for a predetermined time. During a predetermined time, the working fluid reservoir is maintained at a predetermined pressure, so that when the engine is restarted within the predetermined time, it is not necessary to increase the pressure in the working fluid reservoir again, thereby eliminating wasteful energy consumption. be able to.

Further, since the working fluid reservoir is not controlled to be in the open state within a predetermined time after the engine stall, a sound that pressure is released from the working fluid reservoir at the same time as engine stall does not occur, and the driver feels discomfort. It will not be given. In addition, there is no need to add a special structure or a new sensor to the conventional braking energy regenerating device, and this device can be realized only by adding control software. There is no advantage.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the engine stall detecting means includes an ignition key turned on and an engine rotation. the number is configured to detect the stalling of the engine when the 0, Ru can be easily detected stall of the engine.

[0163]

[0164]

[0165]

According to the third aspect of the present invention, there is provided a working fluid storing means for storing a working fluid, and a pressure storing means for storing the working fluid in a high pressure state.
A pump mode that operates by receiving the rotational energy of the axle of the vehicle, pressurizes the working fluid from the working fluid storage means and supplies the working fluid to the pressure accumulating means as fluid pressure energy, and converts the fluid pressure energy stored in the pressure accumulating means into rotational energy Energy conversion means capable of taking a motor mode for converting to, a connection and disconnection means interposed between the energy conversion means and the wheels of the vehicle,
Operating means for connecting / disconnecting the connecting / disconnecting means, energy conversion mode switching means for switching the energy converting means between the motor mode and the pump mode, and pumping the energy converting means during braking of the vehicle A braking energy regenerating device having control means for controlling the energy conversion mode switching means so as to set the energy conversion means to the motor mode when the vehicle starts or accelerates. A pressurizing means for pressurizing the pressure of the working fluid at a pressure lower than the inside of the pressure accumulating means and at a pressure higher than the atmospheric pressure, and supplying a pressing force from the pressurizing means to the working fluid storing means Pressurized state switching means capable of switching between a pressurized state and an open state in which the supply of pressurizing force from the pressurizing means is cut off to open the working fluid reservoir to atmospheric pressure; Pressurized state control means for controlling the pressurized state switching means to be in a pressurized state when the engine is operating, and to basically open the pressurized state switch means when the engine is stopped. When the pressure state control means detects that the rotation of the engine has stopped, the engine is stopped by operating the ignition key because the pressurized state switching means is kept in the pressurized state for a predetermined time after the detection. Thereafter, the working fluid reservoir is not released to the atmosphere within a predetermined time, and it is not necessary to pressurize the working fluid reservoir when restarting immediately, so that energy can be saved.

[0167]

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an overall configuration of a braking energy regeneration device according to a first embodiment of the present invention.

FIG. 2 is a schematic block diagram showing a configuration of a control system in the braking energy regeneration device according to the first embodiment of the present invention.

FIG. 3 is a flowchart for explaining a control procedure at the time of engine stall in the braking energy regenerating apparatus as the first embodiment of the present invention.

FIG. 4 is a flowchart illustrating a control procedure when an abnormality occurs in the braking energy regeneration device according to the first embodiment of the present invention.

FIG. 5 is a flowchart illustrating a control procedure when an abnormality occurs in the braking energy regeneration device according to the first embodiment of the present invention.

FIG. 6 is a flowchart for explaining a control procedure in a pump mode for converting braking energy into fluid pressure energy during normal operation in the braking energy regenerating device as the first embodiment of the present invention.

FIG. 7 is a flowchart for explaining a control procedure in a pump mode for converting braking energy into fluid pressure energy during normal operation in the braking energy regenerating device as the first embodiment of the present invention.

FIG. 8 is a flowchart for explaining a control procedure in a pump mode for converting braking energy into fluid pressure energy during normal operation in the braking energy regenerating device as the first embodiment of the present invention.

FIG. 9 is a flowchart for explaining a control procedure in a motor mode for converting fluid pressure energy into starting energy or acceleration energy during normal operation in the braking energy regenerating device as the first embodiment of the present invention.

FIG. 10 is a flowchart for explaining a control procedure in a motor mode for converting fluid pressure energy into start-up energy or acceleration energy during normal operation in the braking energy regenerating device as the first embodiment of the present invention.

FIG. 11 is a flowchart for explaining a control procedure in a motor mode for converting fluid pressure energy into starting energy or acceleration energy during normal operation in the braking energy regenerating apparatus as the first embodiment of the present invention.

FIG. 12 is a flowchart for explaining a control procedure in a motor mode for converting fluid pressure energy into starting energy or acceleration energy during normal operation in the braking energy regenerating device as the first embodiment of the present invention.

FIG. 13 is a map showing characteristics of signal values for determining a pump displacement of a pump / motor in the braking energy regeneration device according to the first embodiment of the present invention.

FIG. 14 is a map showing characteristics of an accelerator opening degree discrimination value in the braking energy regenerating device as the first embodiment of the present invention.

FIG. 15 is a map showing characteristics of signal values for determining the motor capacity of the pump / motor in the braking energy regeneration device according to the first embodiment of the present invention.

FIG. 16 is a flowchart illustrating a control procedure when the engine is stopped in the braking energy regeneration device according to the second embodiment of the present invention.

FIG. 17 is a flowchart for explaining a control procedure when the engine of the conventional braking energy regenerating device is stalled.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Engine 2 Clutch 3 Transmission 3A Finger control Transmission control unit 5 Fuel injection device 10 Drive shaft 12 Drive shaft as a drive system member 13 Transmission output shaft 20 Piston type accumulator as pressure accumulating means 21 Piston 22 Gas chamber 23 Hydraulic oil chamber 24 Shut off Valve 25 Unload valve 30 Low-pressure hydraulic oil tank as working fluid reservoir 31 Pressurized air tank as pressurizing means 32 Sub-air tank as pressurizing means 33 Electromagnetic 2-port switching valve 34 Electromagnetic as pressurized state switching means 3 port switching valve 35 Pressure reducing valve 36 Air dryer 38 Filter 39 Drain tank 39A Reservoir tank 39B Reservoir switch as working fluid amount detecting means 40 Swash plate as energy converting means Variable displacement axial piston pump / motor 40a First port 40b Second port 40c Piston 40d Swash plate 40e Drive shaft 40f Cylinder 41 Tilting cylinder 41a Piston 41b, 41c Chamber 42 Proportional solenoid valve as energy conversion mode switching means 43 Pilot hydraulic pressure Source 44 Electromagnetic 2-port switching valve 45 Filter 50 Gear box 50a, 50b Gear 51 Dog clutch as disconnecting / connecting means 52 Air tank 53 Electromagnetic 3-port switching valve (dog clutch contact valve) 54 Electromagnetic 3-port switching valve (dog clutch disconnect valve) 55 operation means 59 pump 60 control unit (EC
U) 60A Abnormality judging means 60B Overspeed judging means 60C Abnormality control means 60D Pressurized state control means 61 Accelerator opening sensor 62 Engine clutch connection / disconnection sensor 64 Main switch 65 Diag switch 66 Accumulation indicator 67 Electronic governor control unit (also engine) (Revolution number sensor) 68 Regenerative lamp 69 Diag lamp 70 Brake pressure sensor 83 Vehicle speed sensor as speed detecting means 84 T / M reverse sensor 85 T / M neutral sensor 87 Piston position sensor 88 Pressure accumulation sensor 89 Discharge as working fluid pressure detecting means Pressure sensor 90 Hydraulic oil level sensor 91 Oil temperature sensor 92 Dog clutch connection / disconnection sensor 93 Rotation speed sensor 98A, 98B Electromagnetic 2-port switching valve 100 Brake pedal 104 Accelerator pedal 105 Latch pedal 106 differential WR driving wheels P1 high pressure oil passage P2 low pressure oil passage P3 oil passage P4 pilot line

Claims (3)

(57) [Claims] An energy which is interposed in a fluid passage between a working fluid storing means for storing a working fluid and a pressure accumulating means for accumulating fluid pressure energy and is connected to a drive system member of a vehicle via a disconnecting / connecting means. The conversion means converts the fluid pressure energy into braking energy by operating the pump during braking to accumulate the fluid pressure energy in the pressure accumulating means, and starts the fluid pressure energy accumulated in the pressure accumulating means during start acceleration. A braking energy regenerating device that utilizes acceleration energy and stops the working fluid storage means when the engine is stopped. The engine stall detects an engine stall that switches from an operating state to a stopped state without a stop operation. The engine is switched from an operating state to a stopped state by the engine stall detecting means. It is when it is detected, within a predetermined time, characterized in that it is controlling the hydraulic fluid reservoir means to prevent air release, the braking energy recovery device. 2. An engine stall detecting means, wherein an ignition key is on and an engine speed is 0
2. The braking energy regenerating apparatus according to claim 1, wherein the system is configured to detect a stall of the engine at the time of (i) . 3. Working fluid storage means for storing working fluid, pressure accumulating means for accumulating the working fluid in a high pressure state, and operating by receiving rotational energy of an axle of a vehicle and operating the working fluid from the working fluid storing means. Energy conversion means capable of taking a pump mode for supplying fluid pressure energy to the pressure accumulating means by pressurization and a motor mode for converting fluid pressure energy stored in the pressure accumulating means into rotational energy; the energy conversion means and the vehicle Connecting / disconnecting means interposed between the wheels of the vehicle, operating means for connecting / disconnecting the connecting / disconnecting means, and an energy conversion mode capable of switching the energy conversion means between the motor mode and the pump mode Switching means; and the energy conversion means for setting the energy conversion means to the pump mode when the vehicle is braked and for setting the energy conversion means to the motor mode when the vehicle starts or accelerates. A braking energy regenerating device having a control means capable of controlling a lug conversion mode switching means, wherein the pressure of the working fluid in the working fluid storing means is lower than that in the pressure accumulating means, and is lower than the atmospheric pressure. A pressurizing means capable of pressurizing to a high pressure state; a pressurized state in which a pressurizing force from the pressurizing means is supplied to the working fluid storing means; Pressurized state switching means capable of switching between an open state and an open state in which the pressurized state switching means is opened when the engine of the vehicle is operated. And pressurized state control means for performing control so as to bring the engine into an open state. Hold pressure Characterized in that it is configured to
Braking energy regeneration equipment.