JPH051179B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a deceleration energy recovery device that utilizes vehicle deceleration energy as starting energy. (Prior art) Deceleration energy (inertia energy) when a vehicle decelerates is recovered and stored in an accumulator, and the accumulated energy stored in the accumulator is transmitted to an accessory device other than the wheel drive system, such as a crane, to generate a crane. PTO (Power take)
off) Vehicle deceleration energy recovery devices with output devices are known in the prior art. (Problems to be Solved by the Invention) The conventional vehicle deceleration energy recovery device transmits the accumulated energy stored in the accumulator to an accessory device other than the wheel drive system, such as a crane, It is not used as starting energy when the vehicle starts, and its structure is complicated, so if it is used as it is, the deceleration energy (inertia energy) when the vehicle decelerates is recovered and stored in the accumulator, while the accumulated energy stored in the accumulator is used when the vehicle starts. There was a problem that it was difficult to use it as starting energy. In addition, if the deceleration energy of the vehicle is absorbed by the hydraulic oil in the oil tank through the low-pressure oil passage by an oil pump connected to the wheel drive system, and then forced to be sent to the accumulator, cavitation will occur in the low-pressure oil passage. To avoid this, if the oil tank is installed higher than the oil pump and used as a head tank, the installation location of the oil tank will be restricted. Furthermore, if the oil tank is pressurized with pressurized air even when the deceleration energy recovery device is inactive, with the operating switch turned off, the amount of hydraulic oil leaking from the seals of the hydraulic circuit from the oil tank to the accumulator can be reduced. This causes the inconvenience of an increase in . The present invention has been made to solve the various problems mentioned above, and it collects deceleration energy during vehicle deceleration and stores it without complicating the structure, and uses the stored energy as starting energy for the vehicle. In addition, it prevents cavitation of the low-pressure oil circuit during pump/motor deceleration energy recovery operation, minimizes the amount of hydraulic oil used, and saves space for the oil tank installation location. The object of the present invention is to provide a vehicle deceleration energy recovery device that makes effective use of energy. (Means for solving the problems) In order to achieve the above object, according to the present invention,
A transmission comprising a countershaft driven via a clutch on the engine side, a mainshaft connected to a wheel drive system, and a multi-stage gear train mechanism that transmits the rotation of the countershaft to the mainshaft in a variable speed manner; Countershaft attached to the shaft so that it can be disconnected via the countershaft PTO gear synchronizer
The PTO gear and the countershaft mesh with the PTO gear, and the main shaft is connected to the main shaft.
A multi-stage variable speed type that has a main shaft PTO gear that can be connected and disconnected via a PTO gear synchronizer, and a PTO output shaft that is driven via a drive gear meshed with the main shaft PTO gear.
a PTO output device, a pump motor connected to the PTO output shaft, a high pressure oil circuit extending from a first port of the pump motor to an accumulator, and a low pressure oil circuit extending from a second port of the pump motor to an oil tank. , a pressurized air supply source connected to the oil tank and supplying pressurized air to the oil tank, an on-off valve disposed in an air passage between the pressurized air supply source and the oil tank, and detecting vehicle speed. A vehicle speed sensor, a control means for causing the pump/motor to function as either a pump or a motor depending on the operating state of the vehicle, and supplying power to at least the multi-speed PTO output device and the on-off valve via the control means. Turn on/off the power by manual operation.
The control means is provided with a switch means for turning off, and the control means opens the on-off valve when the vehicle speed detected by the vehicle speed sensor is substantially zero and the switch means is in the on state. A deceleration energy recovery device for a vehicle is provided. (Function) The control means of the vehicle deceleration energy recovery device of the present invention causes the pump motor to function as a pump when the vehicle is decelerated, so that the rotation of the wheels is controlled by the main shaft,
Mainshaft PTO gear, drive gear, and PTO
When the signal is transmitted to the pump/motor via the output shaft, the pump/motor pumps the hydraulic oil in the oil tank.
The hydraulic oil is sucked into the pump/motor from the second port of the motor, and the hydraulic oil is sent under pressure to the accumulator from the first port, and the pressure is accumulated in the accumulator. Further, when the vehicle starts, the control means causes the pump motor to function as a motor, and the hydraulic oil of the accumulator flowing into the first port of the pump motor drives the pump motor, and then returns to the oil tank from the second port. It will be done. At this time, the rotation of the pump motor is
The hydraulic pressure is transmitted to the wheels via the PTO output shaft, drive gear, main shaft PTO gear, countershaft PTO gear, countershaft, transmission gear, and main shaft, and as the wheels rotate, the hydraulic pressure stored in the accumulator is used as starting energy. This will help improve fuel efficiency. Furthermore, the control means opens the on-off valve when the vehicle speed detected by the vehicle speed sensor is substantially zero and the switch means, which is an operating switch of the deceleration energy recovery device, is in the on state, and the pressurized air supply source is turned off. Pressurized air is supplied to the oil tank to pressurize the hydraulic oil and prevent cavitation in the low pressure oil circuit while the pump motor functions as a pump. (Embodiment) Hereinafter, an embodiment of the vehicle deceleration energy recovery device of the present invention will be described with reference to the drawings. 1st
The figure shows the overall configuration of the deceleration energy recovery device.
Reference numeral 1 denotes, for example, a diesel engine mounted on a vehicle, and the output shaft of the engine 1 is a clutch 2, a transmission 3, a drive shaft 12a,
and is connected to the wheels 12c via the differential gear 12b. The transmission 3 includes a transmission case 3a, an input shaft 19 connected to the output shaft of the engine 1 via the clutch 2, a main shaft 4, a countershaft 5, and a gear ratio to the main shaft 4. A plurality of transmission gears 17 provided correspondingly, a plurality of transmission gears 18 provided on the counter shaft 5 corresponding to the transmission ratio, and a multi-speed PTO output device (power extraction device) to be described later.
3'. The respective transmission gears 17 and 18 according to the selected transmission ratio mesh with each other to change the speed of the rotation of the engine 1 and transmit it to the wheels. Next, the main shaft PTO gear 6 of the multi-speed PTO output device 3' is loosely fitted on the output side of the main shaft 4.
A countershaft PTO gear 10 meshing with the gear 6 is loosely fitted to the output side of the countershaft 5. Further, a main shaft PTO gear synchronizer 9 and a counter shaft PTO gear synchronizer 11 are installed on each output side of the main shaft 4 and the countershaft 5, respectively. Furthermore, a drive gear 7a that meshes with the main shaft PTO gear 6 is connected to the PTO output shaft 8 via a gear 7b. The main shaft PTO gear 6, countershaft PTO gear 10, main shaft PTO gear synchronizer 9, countershaft PTO gear synchronizer 11, PTO output shaft 8, etc. constitute a multi-speed PTO output device 3'. PTO output shaft 8 of multi-speed PTO output device 3'
is connected to a pump motor 16 via a coupling 13 and an electromagnetic clutch 14. This pump
The motor 16 has a high pressure oil passage 40 at its first port 28.
The high pressure oil passage 40 is connected to the accumulator 41 via a cutoff valve 44. These high pressure oil passages 40, cutoff valves 44, and accumulators 41
A high pressure oil circuit is constructed. The second port 29 of the pump motor 16 is connected to the low pressure oil line 42;
The low pressure oil passage 42 is connected to a pressurized oil tank 43. The low pressure oil path 42 and the pressurized oil tank 43 constitute a low pressure oil circuit. A pipe line 43a is connected to the pressurized oil tank 43, and this pipe line 43a
communicates with the air tank 45, and a solenoid valve 46 for pressurized air control, a pressure reducing valve 47, and an air dryer 48 are arranged in this order from the pressurized oil tank 43 side in the middle of the pipe line 43a. The cutoff valve 44 is an electromagnetic pilot operated valve, and is composed of an electromagnetic switching valve 80 and a logic valve 81. The logic valve 81 is provided with a valve body 81a, a spring 81b that presses the valve body 81a in the direction of closing the high pressure oil passage 40, and behind the valve body 81a,
and a pressure chamber 81c that accommodates a spring 81b. The electromagnetic switching valve 80 is, for example, a poppet valve,
When it is off (when it is in the normal position shown), the high pressure oil passage 4 on the side of the accumulator 41 from the shutoff valve 44
1st pilot oil pressure supply path 82 branching from 0
is communicated with the pressure chamber 81c of the logic valve 81,
While the logic valve 81 is turned on to shut off the high pressure oil passage 40, when it is turned on, the first pilot oil pressure supply passage 82 is shut off and the pressure chamber 81c is drained from the drain tank 55.
communicate with. Shutoff valve 44 and pump motor 16
Relief oil passage 49 branching from high pressure oil passage 40 between
extends to the pressurized oil tank 43, and the relief oil path 49 is provided with a relief valve 50, a hydraulic motor 51, and a cooler (radiator) 52 in this order from the branch side. A fan 53 is attached to the output shaft of the hydraulic motor 51, and the fan 53 blows cooling air to the cooler 52. Reference numeral 54 is a supply oil passage extending from the drain tank 55 to the high pressure oil passage 40 and the low pressure oil passage 42,
The supply oil passage 54 branches into two oil passages 54a and 54b, and one oil passage 54a is connected to the relief oil passage 49.
high pressure oil line 40 between the branch point and the pump/motor 16
The other oil passage 54b is connected to the low pressure oil passage 42, respectively. A parallel circuit 56 consisting of a check valve and a relief valve is disposed in the middle of each oil passage 54a, 54b.
a and 56b are provided, respectively. Supply oil line 54
Solenoid valve A, relief valve 57, filter 58, solenoid valve B,
An oil pump 59 and a filter 60 are arranged in this order. The solenoid valve A is a two-position switching valve, and when it is off (in the normal position shown), it shuts off the supply oil passage 54 and connects it to the oil passage 54d and the cooler 6.
1 to the drain tank 55. For example, a known gear pump is used as the oil pump 59, and the oil pump 59 is constantly driven by the engine 1 or the electric motor.
The hydraulic oil is force-fed to the replenishment oil passage 54. The solenoid valve B is also a two-position switching valve, and when it is off (in the normal position shown), it shuts off the supply oil passage 54 and transfers the hydraulic oil sent from the oil pump 59 to the drain tank 55 via the oil passage 54c. circulate. Further, a relief oil passage 54e provided with a relief valve 62 is connected to the supply oil passage 54 between the branch point of the oil passages 54a and 54b and the solenoid valve A. A second pilot hydraulic pressure supply path 63 branches from the supply oil path 54 between the relief valve 57 and the filter 58, and is connected to a solenoid valve 30 that controls the displacement of the pump motor 16. The details of the displacement control solenoid valve 30, the pump motor 16, and the piston 32 which is an actuator that drives the swash plate of the pump motor 16 are shown in FIG.
This will be explained with reference to FIGS. 4 to 4. The capacity control solenoid valve 30 is a 4-port servo valve, and the spool 3
1, and solenoids 35a and 35b provided at both ends of the spool 31.These solenoids 35a and 35b are connected to a drive circuit 36 via a power connector 35, and this drive circuit 36 is connected to an electronic control unit (hereinafter referred to as this). (referred to as "ECU") 64. The spool 31 moves according to the control current value of the solenoid drive (energizing) signal from the drive circuit 36 supplied to the solenoids 35a, 35b.
When no drive signal is applied to any of the spools 35b, the spool 31 is in the neutral position shown. The pump/motor 16 is of a variable displacement axial piston type, and the rotating shaft 2 of the pump/motor 16 is
1 is connected to the electromagnetic clutch 14. A cylinder 25a is bored in the cylinder block 25 spline-engaged with the rotating shaft 21, and a piston 24 is slidably fitted into the cylinder 25a. A shoe 23 is engaged with a spherical end 24a of the piston 24 that protrudes from a cylinder 25a. When the rotating shaft 21 rotates, the cylinder block 25 also rotates together with the rotating shaft 21, and the piston 24 moves through the shoe 23. It reciprocates within the cylinder 25a while sliding on the swash plate 22. At this time, depending on the tilt angle of the swash plate 22, the pump motor 1
6 will operate as a pump or motor. A rod 32a fixed to a tilt angle control piston 32 is engaged with the swash plate 22, and a spring 34,
34 urges the tilt angle control piston 32 to the neutral position. A spool 3 of the displacement control solenoid valve 30 is provided between the tilt angle control piston 32 and the capacity control solenoid valve 30 to control the movement of the tilt angle control piston 32.
Feedback mechanism 33 that provides feedback to 1
is provided. Reference numerals 27a and 27 in Fig. 2
b are a casing and an end block, respectively;
The end block 27b is provided with the aforementioned first port 28 and second port 29, and each port 28, 2
9 is the end block 27b and cylinder block 2
It communicates with the cylinder 25a through suction/discharge holes 26a, 26a of a valve plate 26 interposed between the valve plate 26 and the cylinder 25a. When a drive signal is given from the drive circuit 36 to either of the solenoids 35a, 35b of the capacity control solenoid valve 30, the spool 31 moves according to the drive signal value, and the pilot pressure oil from the pilot oil pressure supply path 63 is tilted. Angle control piston 32
Hydraulic chambers 32b and 32c facing one of the hydraulic working surfaces of
At the same time, the pressure oil in the hydraulic chambers 32c and 32b facing the other hydraulic surface is drained, and the tilting angle control piston 32 is thereby moved to control the tilting angle of the swash plate 22. Also, the tilting angle control piston 3
2 is transmitted to the spool 31 of the capacity control solenoid valve 30 via the feedback mechanism 33, whereby the spool 31 returns to the neutral position and the tilting angle of the swash plate 22 is controlled to a required angle value. . By setting the tilt angle of the swash plate 22, the pump motor 16
When the pump operates as a pump, the pump motor 16 pumps the hydraulic oil in the pressurized oil tank 43 to the accumulator 41 via the low pressure oil passage 42, the second port 29, the first port 28, and the high pressure oil passage 40.
Furthermore, when the pump/motor 16 operates as a motor, the high-pressure hydraulic oil stored in the accumulator 41 is supplied to the pump/motor 16 through a route opposite to that when the pump/motor 16 operates as a pump, and is supplied to the cylinder block 25 and The rotating shaft 21 is rotated.
The tilt angle control mechanism for the swash plate 22, including the feedback mechanism, is conventionally known, so a detailed explanation thereof will be omitted. The pressurized air control solenoid valve 46 and the supply oil path 54
The electromagnetic valves A and B and the electromagnetic switching valve 80 arranged in the electromagnetic switching valve 80 are both electrically connected to the ECU 64, and are supplied with drive signals D1 to D4 from the ECU 64, respectively. Also, the output side of the ECU 64 is the engine clutch 2, electromagnetic clutch 14, main and countershaft PTO gear synchronizers 9 and 1.
1, and the ECU 64 gives drive signals to these. The ECU 64 includes a stroke sensor (potentiometer, hereinafter referred to as "accelerator sensor") 65 attached to an accelerator pedal (not shown), and a stroke sensor (potentiometer (hereinafter referred to as "accelerator sensor") 65 attached to an accelerator pedal (not shown)). meter, this stroke sensor is hereinafter referred to as the "brake sensor")6
6. Clutch sensor 67 is attached to the clutch pedal (not shown) and outputs an off signal when the clutch pedal is depressed; Clutch sensor 67 is attached to the transmission shift lever (not shown) and outputs the selected gear of the transmission 3. A gear stage sensor 68 for detection and a main switch 78 for operating a deceleration energy recovery device are electrically connected, and each detection signal is supplied to the ECU 64. Further, a pressure sensor 69 is attached to the high pressure oil passage 40 between the shutoff valve 44 and the accumulator 41, and a pressure detection signal P is supplied from the pressure sensor 69 to the ECU 64. A level sensor 70 for detecting the oil level is attached to the drain tank 55.
detects whether the oil level in the drain tank 55 is above a predetermined value and sends the level detection signal L to the ECU 64.
supply to. Reference numeral 77 is a charge switch attached to, for example, the driver's seat of the vehicle. When the driver desires to accumulate pressure in the accumulator 41, the charge switch 77 is turned on to give a charge command signal to the ECU 64. Further, a tilt angle neutral position sensor 71 detects whether the tilt angle control piston 32 is in a neutral position and supplies a tilt angle neutral position signal NP to the ECU 64, and a main shaft 4 of the transmission 3. A vehicle speed sensor 73 detects vehicle speed from the rotational speed of a flywheel 72 fixed to the output side end of the main and countershafts.
The engagement states of PTO gear synchronizers 9 and 11 are detected, and synchronized feedback signals are generated respectively.
Synchro detection sensors 74 and 75 that supply MSF and CSF to the ECU 64 and a neutral sensor 76 that detects the neutral state of the transmission 3 are electrically connected to the ECU 64, respectively. The engine 1 is equipped with a fuel injection pump 84 equipped with an electronic governor 83.
is electrically connected to an electronic governor control unit 86, and its operation is electronically controlled by the electronic governor control unit 86. Then, the electronic governor control unit 86 and the
They are electrically connected to the ECU64,
The ECU 64 supplies the electronic governor control unit 86 with an accelerator signal based on the amount of depression of the accelerator pedal detected by the accelerator sensor 65 (or a pseudo accelerator signal described later) and a charge request signal described later. For example, from ECU64,
An engine rotation speed signal Ne that detects the engine rotation speed is supplied by a rotation speed sensor 90 provided on the camshaft of the electronic governor 83 . Reference numeral 84 is a warning light, and the accumulator 4 is activated based on the pressure detection signal P input to the ECU 64.
When the oil pressure in the engine 1 is below a predetermined pressure (for example, 250 kgf/cm ² ), the ECU 64 turns on the warning light 87 and issues an alarm. Further, reference numeral 88 is a brake light (stop light), which is connected to the brake sensor 6 mentioned above.
6 detects that the amount of depression of the brake pedal exceeds a predetermined value, which will be described later, the ECU 64 turns on the brake light 88. Next, the operation of the deceleration energy recovery device configured as described above is shown in FIGS. 5 to 11.
This will be explained with reference to a program flowchart executed within the ECU 64 and FIGS. 12 to 19. The ECU 64 supplies drive signals to the engine clutch 2, main and countershaft PTO gear synchronizers 9 and 11, and electromagnetic clutch 14, respectively, based on detection signals from the various sensors described above. Solenoid valve A
and B, and the electromagnetic switching valve 80, a tilting angle control signal is supplied to the drive circuit 36, and a drive signal is supplied to the capacity control electromagnetic valve 30 to operate the deceleration energy recovery device as follows. operate like this. First, the ECU 64 executes step 100 of the main flowchart shown in FIG.
Based on the vehicle speed signal V from 3, it is determined whether the vehicle speed is 0 km/h, that is, whether the vehicle is stopped. If the answer is affirmative (Yes), the process directly proceeds to step 101, where it is determined whether the main switch 78 of the deceleration energy recovery device is on or off. If the main switch 78 is in the off state
ECU 64 provides all outputs to the deceleration energy recovery device, i.e. main and countershaft PTO.
Gear synchronizer 9, 11, electromagnetic clutch 1
4. Pressurized air control solenoid valve 46, solenoid valves A and B, solenoid switching valve 80, and capacity control solenoid valve 30
Step 100 is repeated until the main switch 78 is turned on in step 101 without supplying a drive signal to the main switch 78 (step 102). When the ON state of the main switch 78 is detected, step 104 is executed, and the ECU 64 supplies the drive signal D1 to the pressurized air control solenoid valve 46 to open the pipe line 43a, and the pressure is accumulated in the air tank 45. After the high pressure air is regulated to a predetermined pressure by a pressure reducing valve 47, it is led to a pressurized oil tank 43. This makes it possible to pressurize the hydraulic oil in the oil tank 43 and prevent cavitation in the low pressure oil passage 42. The oil tank can also be installed on the roof of a vehicle such as a bus and used as a head tank. The pressurized oil tank 44 can be installed at any position without having to do so. The deceleration energy recovery device is activated for the first time when the main switch 78 is turned on when the vehicle is stopped, and is activated only when the deceleration energy recovery device is inactive (main switch 78
8), the solenoid valve 46 is deenergized (step 102) and switched to the normal position shown in FIG. The amount of oil leaking from each seal part of the hydraulic circuit from 43 to the accumulator 41 and flowing back into the drain tank 55 can be reduced or eliminated, and the capacity of the drain tank 55 can be minimized. Note that the pressure reducing valve 47 disposed in the pipe line 43a is connected to the air tank 45.
The high-pressure air from the tank is regulated to a predetermined pressure, and the air pressure inside the pressurized oil tank 43 is kept constant. Next, the value of a flag f0, which will be described later, is set to 1 (step 105), and the process proceeds to step 106, where it is determined based on the vehicle speed signal V from the vehicle speed sensor 73 whether the vehicle speed is equal to or higher than a predetermined value (for example, 65 km/h). Determine whether
When the vehicle is stopped, the vehicle speed is determined in step 106.
Of course, it is determined that the vehicle speed is 65 km/h or less, but once the vehicle starts running, the vehicle speed is determined to be 65 km/h or less.
When the speed exceeds Km/h, the flag f0 value is set to zero (step 107), and step 102 is executed.
All output from the ECU 64 to the deceleration energy recovery device is turned off, that is, the operation of the deceleration energy recovery device is stopped. This is because when the vehicle speed exceeds 65 km/h, the main and countershaft PTO gear synchronizers 9 and 11 cannot synchronize, and the rotation speed of the pump motor 16 exceeds the allowable rotation speed, so when the vehicle speed exceeds 65 km/h. If an attempt is made to recover the deceleration energy, the life of the pump/motor 16 will be adversely affected, so the operation of the deceleration energy recovery device is forcibly stopped. If the determination result in step 100 is negative (No), that is, if the vehicle speed is 0 km/h or more, step 103
Proceeding to step , the flag f0 value is determined. Once the flag f0 is set to the value 0 in step 107, the determination result in step 103 is that f0 is always 0 until the vehicle is stopped.
102 continues to be executed. However, the vehicle speed is 65
Km/h or more, the determination result in step 103 is f0 = 1, in which case the step 101
will be executed. If it is determined in step 106 that the vehicle speed is 65 km/h or less, the process proceeds to step 110, where the electromagnetic valve A/B control subroutine shown in FIG. 6 is executed. This subroutine sets the solenoid valves A and B shown in FIG. 1 to the operating modes shown in Table 1 in accordance with the operating conditions of the vehicle.

[Table] First, in step 111 of Figure 6, ECU6
Step 4 determines whether the oil level in the drain tank 55 is equal to or higher than a predetermined value based on the level detection signal L from the level sensor 70 attached to the drain tank 55 shown in FIG. When the oil level in the drain tank 55 is above the predetermined value, the ECU 64 executes oil replenishment mode control and closes the solenoid valves A and B.
The drive signals D2 and D3 are outputted to the solenoid valves A and B to turn them on (energized) (steps 112 and 113). As a result, the hydraulic oil discharged by the pump 59 to the supply oil path 54 is supplied to the high pressure oil path 40 (or low pressure oil path 42) via the opened solenoid valves A and B and the parallel circuit 56a (or 56b). That will happen. Accumulator 41 in Figure 1
If the hydraulic oil that was being supplied to the hydraulic circuit from the to the pressurized oil tank 43 leaks from the seals of the hydraulic circuit and is returned to the drain tank 55, the amount of oil in the drain tank 55 will increase accordingly. Therefore, when the oil level in the drain tank 55 exceeds the predetermined value, the excess hydraulic oil is transferred to the high pressure oil line 40.
(or the low-pressure oil path 42), the amount of oil in the hydraulic circuits of the accumulator 41 and pressurized oil tank 43 can always be kept at a constant value. In step 111, the drain tank 55
When it is determined that the oil level is not equal to or higher than the predetermined value, the process proceeds to step 114, where it is determined whether a charge request condition, which will be described later, is satisfied. Here, the charge request condition means that the neutral state of the transmission ³ is detected by the neutral sensor 75 shown in FIG. Yes, and the charge switch 77 installed in the driver's seat is in the on state. When all of these conditions are met, the ECU 64 uses the tilt angle control mode.
The solenoid valve A is deenergized (off) without outputting the drive signal D2 (step 120), and the drive signal D3 is supplied to the solenoid valve B and it is energized (on) (step 121). . As a result, the second pilot oil pressure supply path 63 generates the oil pressure in the supply oil path 54 downstream of the relief valve 57, that is, the pilot oil pressure regulated to a predetermined pressure, and this pilot oil pressure is controlled by capacity control. is supplied to the tilting angle control piston 32 through the solenoid valve 30 for the pump motor 16.
Used for tilt angle control. Since the pump 59 is constantly driven by the engine 1 or the electromagnetic motor, the pilot oil pressure regulated to the required pressure is immediately supplied to the tilt angle control piston 32 when tilt angle control of the pump/motor 16 is to be started. can do. Furthermore, unlike the model that uses a part of the high-pressure hydraulic oil in the high-pressure oil passage 40 as pilot oil, pilot oil pressure is generated by a separately provided pump 59, so loss of high-pressure hydraulic oil (accumulated pressure energy) can be suppressed. At the same time, there is no need to provide a high pressure switching valve for guiding the pilot oil pressure from the high pressure oil passage 40, which simplifies the configuration of the hydraulic circuit. If the charge request condition in step 114 is not satisfied, the process proceeds to step 115, where it is determined based on the signal from the brake sensor 66 whether or not the brake pedal has been depressed. When the amount of depression of the brake pedal is greater than zero, the process proceeds to step 116, where it is determined whether the vehicle speed is greater than 0 km/h. When the vehicle speed is greater than 0 km/h, that is, when the brake pedal is depressed even slightly and the vehicle is not stopped (when the vehicle is decelerating), steps 120 and 121 are executed to activate the second pilot. A pilot hydraulic pressure is generated in the hydraulic pressure supply path 63 in preparation for pump tilting control to be described later. If the brake pedal is depressed but the vehicle speed is 0 km/h,
The ECU 64 deenergizes (turns off) both solenoid valves A and B in the operation stop mode (steps 122 and 123).
At this time, that is, when the pump/motor 16 does not need to function as either a pump or a motor, the hydraulic oil sucked up from the drain tank 55 by the pump 59 is returned to the drain tank 55 via the oil path 54c. Hydraulic oil will not be pumped into the supply oil path 54. Further, the hydraulic oil in the supply oil passage 54 is returned to the drain tank 55 via the deenergized solenoid valve A and the oil passage 54d. In this way, unnecessary hydraulic pressure is prevented from being generated in the second pilot hydraulic pressure supply path 63 when the tilt angle of the swash plate 22 of the pump motor 16 is not controlled as will be described later. When the amount of depression of the brake pedal is zero in step 115, the process proceeds to step 117, and the pressure in the accumulator 41 reaches a predetermined value (for example, 210 kg) based on the pressure detection signal P from the pressure sensor 69.
f/cm ² ) or more. If the pressure inside the accumulator 41 is below a predetermined value (210 Kgf/cm ² ), this means that sufficient deceleration energy has not been accumulated. , B are both turned off. On the other hand, if the pressure inside the accumulator 41 is higher than the predetermined value (210Kgf/cm ² ), step 118 is performed.
Proceed to synchro detection sensors 74, 75 in FIG.
The engagement states of the main and countershaft PTO gear synchronizers 9 and 11 are determined based on the synchro feedback signals MSF and CSF. Countershaft PTO in step 118
When the gear synchronizer 11 is actuated and it is determined that the countershaft PTO gear 10 is fixed to the countershaft 5, the deceleration energy recovery device executes start control or pressure charge control when the vehicle is stopped, which will be described later. In this case, steps 120 and 121 are executed to generate pilot oil pressure in the second pilot oil pressure supply path 63. At step 118, the mainshaft PTO gear synchronizer 9 is activated and the mainshaft
When it is determined that the PTO gear 6 is fixed to the main shaft 4, the process advances to step 119, and based on the signal from the accelerator sensor 65 shown in FIG.
It is determined whether the amount of depression of the accelerator pedal is equal to or greater than a value corresponding to 60% of the total amount of depression. When the amount of depression of the accelerator pedal is equal to or greater than 60%, this means that the deceleration energy recovery device executes the acceleration control described later, and in this case, steps 120 and 121 are executed and the second pilot is activated. A pilot hydraulic pressure is generated in the hydraulic pressure supply path 63. In step 118, if both the main and countershaft PTO gear synchronizers 9 and 11 are in disconnected operation (in the case of synchro open), the process proceeds to steps 122 and 123, where both solenoid valves A and B are turned off. Return to the main routine in Fig. 5, and set the solenoid valves A and B.
When the control subroutine finishes executing, step 130
Then, it is again determined whether the vehicle speed is 0 km/h, that is, whether the vehicle is stopped. If the vehicle is stopped, the value of flag f2, which will be described later, is set to zero (step 131), and the value of flag f1, which will also be described later, is set to zero.
Set the value of 1 to 1 (step 132), and then
Proceed to 134. If the determination result in step 130 is negative (No), the process proceeds to step 133, where the value of the flag f1 is determined and the flag f1 value is set as
If the value 1 set in step 132 is still held, the process advances to step 134. At step 134, the selected gear of the transmission 3 is determined based on the signal from the gear position sensor 68 shown in FIG.
In step 136, the electromagnetic clutch 14 is disengaged without outputting the electromagnetic clutch drive signal DCR.
At step 2, the engine clutch drive signal DEG is output to close the engine clutch 2.
Proceed to 260. Therefore, when the transmission shift lever is in the reverse position, the deceleration energy recovery device is disabled. When it is determined in step 134 that the transmission shift lever is in the neutral position, the value of the flag f2 is set to zero (step 134).
137), in step 138, charge switch 7
The on/off state of 7 is determined. If the charge switch 77 is off, the steps 135 and 136 are performed.
is executed and the deceleration energy recovery device is deactivated. If the charge switch 77 is on in step 138, the process advances to step 139;
Based on the pressure detection signal P of the pressure sensor 69, the pressure inside the accumulator 41 reaches a predetermined pressure (for example, 250
Kgf/cm ² ) or less. If the pressure inside the accumulator 41 is equal to or higher than the predetermined pressure (250 Kgf/cm ² ), sufficient deceleration energy has been accumulated in the accumulator 41, and it is not necessary to accumulate pressure in the accumulator 41 until pressure charge control, which will be described later, is executed. If it is determined that there is no
By executing this, the deceleration energy recovery device will be deactivated. On the other hand, if it is determined in step 139 that the pressure inside the accumulator 41 is below the predetermined pressure (250Kgf/cm ² ), it means that all of the charge request conditions described above are satisfied, and the step
Proceeding to 140, the ECU 64 executes a pressure charge control subroutine. FIG. 7 is a flowchart of the pressure charge control subroutine executed by the ECU 64,
First, in step 141, the driver depresses the clutch pedal using the clutch sensor 67 shown in FIG. 1 to determine whether or not the engine clutch 2 is disengaged. When the driver disengages the engine clutch 2, the process proceeds to step 142;
The ECU 64 sets the pump tilting angle control signal output to the drive circuit 36 to 0V, so that the drive circuit 36 does not output a drive signal to either of the solenoids 30a and 30b of the capacity control solenoid valve 30, and The spool 31 of 30 is held at the neutral position shown in the figure, and a charge request signal to the electronic governor control unit 86 (described later) is turned off (step 143), and an electromagnetic clutch drive signal is also turned off.
The DCR supply is cut off and the electromagnetic clutch 14 is turned off (step 144). On the other hand, if the engine clutch 2 is on (engaged) in step 141, the process proceeds to step 145, and the ECU 64 temporarily stops supplying the engine clutch drive signal DEG to the engine clutch 2, disengages the clutch 2, and then disengages the clutch 2. , main shaft
The supply of the synchro drive signal MSD to the PTO gear synchronizer 9 is also stopped, and the main shaft PTO gear synchronizer 9 is turned off (step 146). Then, the ECU 64 determines whether the main shaft PTO gear synchronizer 9 has reliably completed the disconnection operation based on the synchro feedback signal MSF from the synchro detection sensor 74,
The disconnection operation of the main shaft PTO gear synchronizer 9 waits until the disconnection operation is completed (step
147). When the disengagement of the main shaft PTO gear synchronizer 9 is completed and the main shaft PTO gear 6 is released from the main shaft 4, the process advances to step 148, and the ECU 64 controls the countershaft.
A synchro drive signal CSD is sent to the PTO gear synchronizer 11 to turn it on.
In this case as well, ECU64 is the countershaft PTO
It is determined whether or not the gear synchronizer 11 has definitely completed the contact operation based on the synchro feedback signal CSF from the synchro detection sensor 75, and the system waits until the contact operation of the countershaft PTO gear synchronizer 11 is completed (step 149). . Next, when the countershaft PTO gear synchronizer 11 has been engaged (turned on) and the countershaft PTO gear 10 is fixed to the countershaft 5, the electromagnetic clutch drive signal DCR is supplied to the electromagnetic clutch 14 to connect the electromagnetic clutch 14. After turning on (step 150), ECU64
sends a charge request signal to the electronic control unit 86, causing the electronic governor control unit 86 to control the fuel injection pump 84 to increase the required amount of fuel supplied to the engine 1 (step 151). This copes with an increase in the load placed on the engine 1 due to the operation of the pump/motor 16, which will be described later, in pressure charge control. Next, the ECU 64 resumes supplying the engine clutch drive signal DEG to the engine clutch 2.
After the engine clutch 2 is turned on (step 152), a pump tilt angle control signal having a predetermined positive voltage value is sent to the drive circuit 36 to tilt the swash plate 22 of the pump motor 16. The angle is set to an optimum value for the pump motor 16 to operate as a pump (step 153). And step 154
The pressure inside the accumulator 41 is determined, and if the pressure inside the accumulator 41 is less than the predetermined value (250Kgf/cm ² ), the process proceeds to the step shown in FIG.
Return to 140. Therefore, this pressure charge control subroutine is repeatedly executed while the above charge request condition is satisfied. Thus, as shown by the thick broken line in FIG. 16, the rotation transmitted from the engine 1 to the countershaft 5 via the clutch 2 and transmission input shaft 19 is transmitted to the countershaft PTO gear 10, the main shaft PTO gear 6, Drive gears 7a, 7b, PTO
The pressure oil is transmitted to the pump motor 16 via the output shaft 8, the coupling 13, and the electromagnetic clutch 14, and the pump motor 16, which operates as a pump at this time, pumps the pressure oil into the first
It is stored in the accumulator 41 via the port 28 and the high pressure oil path 40. When the driver turns on the charge request switch 77 provided in the driver's seat, this pressure charge control stores pressure oil in the accumulator 41, which has an insufficient amount of pressure oil, using the engine output in the idling state. be able to. In step 154, the accumulator 4
When it is determined that the pressure within the vehicle exceeds the predetermined pressure (250 Kgf/cm ² ), steps 142 to 144 are executed to deactivate the deceleration energy recovery device;
Execution of the pressure charge control subroutine ends. When the pressure charge control subroutine returns to step 140 in FIG. 5, the process proceeds to step 260, where the pressure in the accumulator 41 is again set at the predetermined pressure (250 Kgf/cm ² ).
If the pressure inside the accumulator 41 is below a predetermined pressure, the warning light 84 shown in FIG. Turn off the light (step
262). This allows the driver to know the state of accumulation of deceleration energy within the accumulator 41. If it is determined in step 134 that the speed change lever is in any position from 2nd speed to 5th speed, the process proceeds to step 160, where the value of flag f2 is determined. This flag f2 is used to determine whether or not the start control subroutine described later has already been executed. When the vehicle is still in a stopped state, the flag f2 value remains at the value 0 set in step 131. Therefore, in such a case, the process proceeds to step 161, where it is determined whether the pressure inside the accumulator 41 is below a predetermined pressure (250 Kgf/m ² ).
If the pressure inside the accumulator 41 is equal to or higher than the first predetermined pressure (250 kgf/cm ² ), the flag f2 is set to 1 (step 162), and a start control subroutine to be described later is executed (step 162).
170). At step 162, the value of flag f2 is set to 1.
When the ECU 64 determines at step 160, the ECU 64 skips steps 161 and 162 and directly proceeds to step 170 to execute the start control subroutine. That is, if the pressure in the accumulator 41 is equal to or higher than a predetermined pressure (250 Kgf/cm ² ) immediately before the vehicle starts, the start control subroutine to be described later is executed.
Once this subroutine is executed, the subroutine will continue to be executed even if the pressure inside the temporary storage accumulator 41 falls below a predetermined pressure (250 kgf/cm ² ). FIG. 8 shows a flowchart of the start control subroutine. First, in step 171, the selected gear of the transmission 3 is determined based on the signal from the gear sensor 68, and the gear shift lever is set to 4th or 5th gear. When the ECU 64 is in either position, the engine clutch drive signal DEG
Clutch 2 is disengaged without outputting (step
172). When starting a vehicle from a stopped state, it is difficult to start if the 4th or 5th gear, that is, a gear inappropriate for starting, is selected, so the clutch 2 is disengaged and the deceleration energy recovery device is activated. The process then returns to the main routine without performing any activation operation on the , leaving it in an inactive state. When it is determined in step 171 that the transmission 3 is in the second gear position, the shift vehicle speed Vo value, which will be described later, is set to a first predetermined value (for example, 5 km/h).
(step 173), and when it is determined that the vehicle is in the third gear position, the shift vehicle speed Vo value is set to a second predetermined value (for example, 10 km/h) (step 174).
Proceed to step 175. In step 175, the vehicle speed V detected based on the vehicle speed signal V from the vehicle speed sensor 73 is compared with the variable speed vehicle speed Vo set in either step 173 or 174. This variable speed
Vo is used to determine whether to drive the vehicle using only deceleration energy or the output of engine 1 in addition to deceleration energy (the latter is called "acceleration control") when the vehicle starts.
As a result of the comparison in step 175, if the vehicle speed V is equal to or higher than the shift vehicle speed Vo, the process proceeds to step 187, where a shift control subroutine to be described later, which is a pre-operation for executing acceleration control, is executed. In step 175, the vehicle speed V is changed to the variable speed vehicle speed Vo.
In the following cases, proceeding to step 176, the ECU 64 sends an engine clutch drive signal to engine clutch 2.
After temporarily stopping the DEG supply and disengaging the clutch 2, the supply of the synchronization drive signal MSD to the main shaft PTO gear synchronizer 9 is also stopped and the main shaft PTO gear synchronizer 9 is disengaged (off). (Step 177). Then, the ECU 64 determines whether or not the main shaft PTO gear synchronizer 9 has reliably completed the discontinuation operation based on the synchro feedback signal MSF from the synchro detection sensor 74.
The system waits until the disconnection operation of the PTO gear synchronizer 9 is completed (step 178). main shaft
The disconnection operation of PTO gear synchronizer 9 is completed and main shaft PTO gear 6 is switched to main shaft 4.
If it is released, proceed to step 179 and ECU
64 sends a synchro drive signal CSD to the countershaft PTO gear synchronizer 11 to turn it on. In this case as well, ECU64
is countershaft PTO gear synchronizer 1
A synchro feedback signal from the synchro detection sensor 75 indicates whether or not the contact action of the synchronizer 1 has been completed.
The determination is made based on the CSF, and the process waits until the contact operation of the countershaft PTO gear synchronizer 11 is completed (step 180). Next, when the contact operation (on) of the countershaft PTO gear synchronizer 11 is completed and the countershaft PTO gear 10 is fixed to the countershaft 5, the process advances to step 181, and the accelerator pedal is depressed based on the signal from the accelerator sensor 65. Determine whether the amount is greater than zero. If it is determined that the amount of depression of the accelerator pedal is greater than zero, this means that the vehicle is in a starting state, and in this case, the process proceeds to step 188, where a motor tilt control subroutine is executed. FIG. 9 shows a flowchart of the motor tilting control subroutine. First, in step 221, it is determined whether the pressure inside the accumulator 41 has decreased below a second predetermined pressure (for example, 210 Kgf/cm ² ). do. The pressure inside the accumulator 41 is
If the pressure decreases below a predetermined pressure (210 Kgf/cm ² ), the hydraulic oil will no longer be able to generate sufficient driving force to drive the pump motor 16 and start and accelerate the vehicle. In such a case, the process proceeds to step 222, and the above-mentioned speed change control is executed. If it is determined in step 221 that the pressure inside the accumulator 41 is equal to or higher than the second predetermined pressure (210 kgf/cm ² ), the process proceeds to step 223, where the ECU 64 outputs a motor tilt angle control signal to the drive circuit 36. do. still,
The second predetermined value, which is the discrimination value in step 221, may be set to different values depending on whether the pressure changes in an increasing direction or in a decreasing direction, in order to stabilize the control. The output value of the motor tilt angle control signal is determined by the accelerator sensor 65 and the synchro detection sensor 7 in FIG.
It is set based on each detection signal from 4 and 75. FIG. 12 is a graph showing an example of the relationship between the output value of the motor tilt angle control signal output from the ECU 64 and the amount of depression of the accelerator pedal (accelerator opening degree). The motor tilt angle control signal value gradually decreases to zero as the accelerator opening increases from the first predetermined value (for example, 40%) along the straight line shown by the solid line in the figure. The output value is decreased in _the negative direction from There is. When the main shaft PTO gear synchronizer 9 is in contact operation, it starts when the accelerator opening is at a second predetermined value (for example, 60%) that is larger than the first predetermined value along the straight line shown by the broken line in FIG. As the opening degree value increases, the output value is gradually decreased from zero in the negative direction, and is set so as to reach the negative predetermined value _VM when the accelerator opening degree is 100%. When the drive circuit 36 applies a required drive signal to either one of the two solenoids 35a, 35b of the capacity control solenoid valve 30 in accordance with the supplied motor tilt angle control signal value, the capacity control solenoid valve 30 The pilot hydraulic pressure generated in the pilot hydraulic pressure supply path 63 of No. 2 is sent to the piston 32 and the piston 30
As a result, the tilting angle of the swash plate of the pump motor 16 is controlled to an optimal value for motor operation at the time of starting. Next, the process proceeds to step 224, where each synchro feedback signal of the synchro detection sensors 74 and 75 is detected.
The engagement states of the main and countershaft PTO gear synchronizers 9 and 11 are determined based on the MSF and CSF. When the motor tilt control is executed in the start control shown in Fig. 8, the step
At step 224, it should be determined that the countershaft PTO gear synchronizer 11 is in contact operation, and in this case, the process proceeds to step 225, where the ECU 64 supplies a pseudo accelerator signal to the electronic governor control unit 86, which the driver depresses. The fuel injection pump 84 is controlled to inject and supply the amount of fuel necessary for the engine to maintain an idle state to the engine 1 regardless of the amount of depression of the accelerator pedal. Then, the process proceeds to step 226, where it is determined whether the amount of depression of the accelerator pedal is equal to or greater than the first predetermined value (40%). The first predetermined value, which is this discrimination value, is also set to a different value depending on whether the amount of accelerator pedal depression changes in an increasing direction or in a decreasing direction, in order to stabilize the control, so as to have a hysteresis characteristic. You may also do so. The determination result of step 226,
If the amount of depression of the accelerator pedal is equal to or greater than the first predetermined value, the ECU 64 supplies the electromagnetic clutch drive signal DCR to the electromagnetic clutch 14 to turn it on (step 227), and then closes the electromagnetic clutch 14 (step 227). The switching valve (poppet valve) 80 is energized by applying the drive signal D4, and the logic valve 81 is opened (step 228). In this way, the high-pressure hydraulic oil stored in the accumulator 41 is guided to the pump motor 16 to drive it, and the rotation of the pump motor 16, which operates as a motor, is caused by the electromagnetic clutch as shown by the thick broken line in FIG. 14, Joint 13, PTO
Output shaft 8, drive gears 7b, 7a, main shaft
PTO gear 6, countershaft PTO gear 10,
It is transmitted to the countershaft 5, the transmission gears 18, 17, and the main shaft 4, and further to the main shaft 4.
The rotation is caused by the propeller shaft 12a and the differential gear 12.
It is transmitted to the wheels 12c, 12c via b.
Note that the hydraulic oil that drove the pump motor 16 is
The oil is returned to the pressurized oil tank 43 via the port 29 and the low pressure oil path 42. In this way, in the start control when sufficient deceleration energy is stored in the accumulator 41, the vehicle is driven only by the driving force from the pump motor 16, and the rotation of the pump motor 16 is changed via speed change gears 17 and 18 interposed between the main shaft 4 and the countershaft 5 of the transmission 3 according to the speed change ratio of the gear stage selected according to the load state (load) of the vehicle. wheel 12c,
12c, optimum starting performance can be obtained. If it is determined in step 226 that the amount of depression of the accelerator pedal is less than the first predetermined value (40%), for example, when attempting to start the vehicle, the amount of depression of the accelerator pedal is insufficient. If you release the accelerator pedal while accelerating or taking off,
Proceeding to step 229, the piston 32 is in the neutral position, that is, the tilt angle of the swash plate 22 of the pump motor 16 is zero, based on the tilt angle neutral position signal NP from the tilt angle neutral position sensor 71 shown in FIG. Determine whether it exists or not. If the amount of depression of the accelerator pedal is less than the first predetermined value (40%), the ECU 6
The tilt angle control signal output value outputted from 4 to the drive circuit 36 is set to zero. There is no problem if the amount of depression of the accelerator pedal is originally less than the first predetermined value (40%), but if the accelerator pedal is returned and becomes less than the first predetermined value, there is a response delay in the hydraulic circuit. Therefore, even if the output value of the tilt angle control signal from the ECU 64 becomes zero, the tilt angle of the swash plate 22 of the pump motor 16 does not immediately become zero. If the electromagnetic clutch 14 is disengaged (off) and the high-pressure oil circuit 40 is shut off (poppet valve 80 is turned off) before the tilting angle has reached zero, vibrations and accompanying noise will occur in the hydraulic circuit, which is preferable. do not have. Therefore, when it is determined in step 229 that the tilt angle is not yet zero (if the determination result in step 229 is negative), steps 230 and 231 described below are executed.
Step 188 in Figure 8 without performing
Return to step 170 in the diagram. Then, in step 229, it is confirmed that the tilt angle has been returned to zero (if the determination result in step 229 is affirmative), and the process proceeds to step 230, where the electromagnetic clutch 14 is disengaged, and in step 231, the electromagnetic clutch 14 is disengaged. The electromagnetic switching valve (poppet valve) 80 of the cutoff valve 44 is deenergized (turned off), the logic valve 81 is closed, and the deceleration energy recovery device is inactivated. If it is determined in step 181 of FIG. 8 that the amount of depression of the accelerator pedal is zero, for example, if the vehicle is in a state immediately before starting, or if the accelerator pedal is completely returned during starting acceleration, The ECU 64 sets the output value of the motor tilt angle control signal to the drive circuit 36 to zero, and returns the tilt angle of the swash plate 22 of the pump motor 16 to zero (step
182). After confirming that the tilt angle of the swash plate 22 has become zero (step 183), the electromagnetic switching valve (poppet valve) 80 of the cutoff valve 44 is deenergized (off).
The logic valve 81 is closed to shut off the high pressure oil passage 40 (step 184). Next, it is determined whether the amount of depression of the brake pedal is zero based on the signal from the brake sensor 64 shown in FIG. 1 (185). If the amount of depression of the brake pedal is zero, the electromagnetic clutch 14 is disengaged (off) to stop the operation of the deceleration energy recovery device (step 186).
Return to the main routine shown in FIG. Also, if the accelerator pedal is released and the brake pedal is depressed during start acceleration when the vehicle speed V has not yet reached the shift vehicle speed Vo, the process proceeds to step 189 as a result of the determination in step 185, where pump tilt control, which will be described later, is executed. Even in such cases, the vehicle's deceleration energy can be recovered. If the vehicle speed V exceeds the shift vehicle speed Vo during start acceleration (step 187 executed based on the determination in step 175 in FIG. 8), and the pressure in the accumulator 41 at the start of start reaches the first predetermined pressure (250 kgf/ ^cm2 )
In the following cases (step 190 executed based on the determination in step 161 in FIG. 5), the above-mentioned speed change control is executed, and the vehicle is driven by the pump motor 16 due to the acceleration control executed following this speed change control. In addition to the power, it is also driven by the driving force of the engine 1. FIG. 10 shows a flowchart of the speed change control subroutine. First, in step 191, the ECU 6
4 sets the output value of the motor tilt angle control signal to the drive circuit 36 to zero to return the tilt angle of the swash plate 22 to zero. Next, the ECU 64 outputs the engine clutch drive signal DEG to engage the engine clutch 2 (step 192), and then waits for a predetermined period of time (for example, 0.1 seconds) to complete the engagement of the engine clutch 2. Wait (step 193),
The true accelerator signal from the accelerator sensor 65 is supplied to the electronic governor control unit 86 (step 194). The electronic governor control unit 86 receives a pseudo accelerator signal from the ECU 64 during start control (step 188 in FIG. 8).
Step 225 of the motor tilt control subroutine executed in Step 225) The fuel injection pump 84 was injecting and supplying the amount of fuel necessary to keep the engine 1 in the idle state, but when a true accelerator signal is received from the ECU 64. The amount of fuel corresponding to the amount of depression of the accelerator pedal is injected and supplied to the engine 1. In addition, ECU64 is engine clutch 2
The reason why a true accelerator signal is given to the electronic governor control unit 86 after waiting for the completion of the engagement operation is to prevent the engine 1 from revving up.
Then, in step 195, pump motor 1
After waiting until the tilt angle of the swash plate 22 of No. 6 becomes zero,
The electromagnetic switching valve (poppet valve) 80 of the isolation valve 44 is deenergized (off), the logic valve 81 is closed (step 196), the electromagnetic clutch 14 is disengaged (off) (step 197), and the deceleration energy is released. Temporarily stop the operation of the recovery device. Then, in steps 198 to 201, the countershaft PTO gear synchronizer 11, which is in contact operation, is turned off, while the main shaft PTO gear synchronizer 9 is switched to contact operation. More specifically, in step 198, the ECU 64
The supply of synchro drive signal CSD to PTO gear synchronizer 11 is stopped and the countershaft is
PTO gear synchronizer 11 is disconnected (off)
(Step 198). Then, the ECU 64 detects whether or not the countershaft PTO gear synchronizer 11 has reliably completed the disconnection operation using the synchro feedback signal CSF from the synchro detection sensor 75.
The system waits until the disconnection operation of the countershaft PTO gear synchronizer 11 is completed (step 199). When the disengagement of the countershaft PTO gear synchronizer 11 is completed and the countershaft PTO gear 10 is released from the countershaft 5, the process proceeds to step 200, where the ECU 64 sends a synchronization drive signal MSD to the main shaft PTO gear synchronizer 9. This is connected to activate (turn on). In this case as well, the ECU 64 determines whether or not the main shaft PTO gear synchronizer 9 has reliably completed the contact operation based on the synchro feedback signal MSF from the synchro detection sensor 74, and the main shaft PTO gear synchronizer 9
Waits until the contact operation is completed (step 201).
Next, the mainshaft PTO gear synchronizer 9 completes the contact operation (on) and the mainshaft
When the PTO gear 6 is fixed to the main shaft 4, the program proceeds to step 202, sets the aforementioned flag f1 to the value 0, and returns to the main routine shown in FIG. When the shift control subroutine is executed, the 18th
The driving force of the engine 1 is transmitted to the wheels 12c, 12c through the path shown by the thick solid line, and the driving force of the pump/motor 16 is transmitted to the wheels 12c, 12c.The path shown by the thick broken line in FIG. Establish. More specifically, from engine 1 to clutch 2
The rotation transmitted to the countershaft 5 via the input shaft 19 of the transmission 3 is transmitted to the main shaft 4 after being changed in speed by the multi-stage change gears 18 and 17 as usual, and furthermore, the rotation of the main shaft 4 is transmitted to the propeller shaft. 12a, differential gear 1
2b to the wheels 12c, 12c, while the pump motor 16 that operates as a motor connects the electromagnetic clutch 14, the joint 13, the PTO output shaft 8,
Drive gears 7b, 7a, main shaft PTO gear 6, main shaft 4, propeller shaft 12
a, and wheels 12c, 1 via the differential gear 12b.
Connected to 2c. As a result, in the main routine of FIG. 5, the determination result at step 130 is negative (No), that is, the vehicle speed is not 0 km/h, and the flag f1 value is determined to be zero at step 133, and the process proceeds to step 210. become. It should be noted that once the speed change control is executed after the vehicle starts, the flag f1 value is held at the value 0 until the vehicle stops, so that the steps after step 210 are thereafter executed every time the main routine is executed. In step 210, ECU 64 provides electronic governor control unit 86 with the true accelerator signal from accelerator sensor 65. As a result, the electronic governor control unit 86 causes the fuel injection pump 84 to inject and supply the engine 1 with an amount of fuel corresponding to the amount of depression of the accelerator pedal. Next, it is determined whether or not the amount of depression of the accelerator pedal is zero (step 211), and if it is not zero, the engine clutch 2 is engaged (step 214), and the process proceeds to step 220.
The motor tilting control subroutine is executed. The motor tilting control subroutine of FIG. 9 is executed again, and in step 221, the pressure inside the accumulator 41 is reduced to the second predetermined pressure (210 Kgf/cm ² ).
After confirming the above, step 223
Then, the ECU 64 sets the output value of the motor tilt angle control signal according to the amount of depression of the accelerator pedal (accelerator opening degree), and supplies this to the drive circuit 36. At this time, as described above, the main shaft PTO gear synchronizer 9 is in contact operation (ON) due to the execution of the speed change control subroutine, so the output value of the motor tilt angle control signal is set along the broken line shown in FIG. . As is clear from FIG. 12, the motor tilt angle control signal output value during acceleration control, and therefore the tilt angle of the swash plate 22 of the pump motor 16, is a smaller value than during start control for the same accelerator opening. Since the motor capacity of the pump motor 16 is set to a small value, the pump/motor 16 is set to a small value.
The load on the motor 16 will be reduced. As a result, from the pump motor 16 to the wheels 12c, 12
The transmission path of the driving force to C is from the path from the countershaft 5 to the main shaft shown in FIG. Even when switching to the path shown in the figure where the transmission is directly transmitted to the main shaft 5, the switching can be smoothly performed without sudden torque fluctuations or vibrations. Next, when it is determined in step 224 that the main shaft PTO gear synchronizer 9 is engaged, the process proceeds to step 232, where the amount of depression of the accelerator pedal (accelerator opening) reaches the second predetermined value (60
%) or more. The second predetermined value, which is a discrimination value, is also set to a different value depending on whether the accelerator pedal depression amount changes in an increasing direction or in a decreasing direction, so as to provide hysteresis characteristics, in order to stabilize the control. It's okay. If the amount of depression of the accelerator pedal is equal to or greater than the second predetermined value, the step
At step 233, the electromagnetic clutch 14 is engaged, and at step 234, the electromagnetic switching valve (poppet valve) 81 of the cutoff valve 44 is energized to open the logic valve 81. As a result, the rotation of the pump motor 16 is transmitted to the wheels 12c, 12c via the path shown by the thick broken line shown in FIG. 18, and the vehicle is driven by the driving force of both the engine 1 and the pump motor 16. will be done. If it is determined in step 232 that the amount of depression of the accelerator pedal is less than or equal to the second predetermined value (60%), the process proceeds to step 229. At this time, since the motor tilting angle control signal output value is set to zero in step 223 (broken line in FIG. 12), the tilting angle of the swash plate 22 of the pump motor 16 changes to zero, but as described above, Street, this swash plate 22
The electromagnetic clutch 14 waits until the tilt angle of
At the same time, the electromagnetic switching valve (poppet valve) 80 of the cutoff valve 44 is deenergized (off) to disable the deceleration energy recovery device (steps 229 to 231). Therefore, in such a case, the vehicle will be driven only by the driving force of the engine 1 (FIG. 14). Also, during the execution of motor tilt control, the accumulator 4
Even if the accumulated pressure energy in the gearbox 1 is consumed and the pressure decreases below the second predetermined pressure (210 kgf/cm ² ), the shift control is repeatedly executed (step 222 in FIG. 9). In this case as well, the vehicle will be driven only by the driving force of the engine 1. Next, when the vehicle is in a steady running state, the accelerator pedal is depressed by the required amount, and even in this case, the process proceeds to step 220 after the determination in step 211 in FIG. 5, and the motor tilt control subroutine is executed. be done. However, when the vehicle is in a steady running state, the ECU 64 disables both the main and countershaft PTO gear synchronizers 9 and 11 (synchro open), and step 235 is executed based on the determination in step 224 in FIG. . In step 235, the ECU 64 sets the output value of the motor tilt angle control signal to the drive circuit 36 to zero, thereby returning the tilt angle of the swash plate 22 of the pump motor 16 to zero. Then, steps 229 to 231
Similarly, it is determined whether the tilt angle of the swash plate 22 has become zero or not, and if the tilt angle is not yet zero, steps 237 and 238, which will be described later, are skipped and the process returns to the main routine. When the tilt angle becomes zero, the electromagnetic clutch 14 is disengaged and the electromagnetic switching valve (poppet valve) 81 of the cutoff valve 44 is deenergized to disable the deceleration energy recovery device (steps 237 and 238). Therefore,
When the vehicle is in a steady running state, the vehicle is driven only by the driving force of the engine 1 (14th
figure). Further, if the vehicle changes from a steady running state to a state where the accelerator pedal is simply returned to the position where the amount of depression is zero, after determining that the amount of depression of the brake pedal is zero in step 212 of FIG.
Proceed to step 213 and disengage the electromagnetic clutch 14 (off)
Make it. Therefore, even in such a case, the vehicle is driven only by the driving force of the engine 1. However, if the brake pedal is depressed and the vehicle enters a deceleration state, for example, if the brake is depressed from a steady running state (proceeding to step 240 after the determination in step 212 in FIG. 5), or during acceleration from a start. When the brake is depressed (step 189 proceeds after the determination in step 185 in FIG. 8), pump tilting control is executed and deceleration energy is accumulated in the accumulator 41 in the following manner. FIG. 11 shows a flowchart of the pump tilting control subroutine. First, in step 241,
The ECU 64 connects the electromagnetic clutch 14 and outputs a pump tilt angle control signal corresponding to the amount of depression of the brake pedal to the drive circuit 36 based on the signal from the brake sensor 66 shown in FIG.
242). Figure 13 is a graph showing an example of the relationship between the pump tilt angle control signal output value output by the ECU 64 and the amount of brake pedal depression. Accordingly, the output value increases linearly, and when the amount of depression reaches a first predetermined value (for example, 30%) of the total amount of depression, the output value increases to a positive predetermined maximum value Vp (for example, +3V to +5V
(predetermined value between). Therefore, when the amount of depression of the brake pedal exceeds the first predetermined value (30%), the pump capacity becomes the maximum value (constant), that is, the deceleration energy is reduced at a relatively early stage of depression of the brake pedal. The tilt angle of the pump/motor 16 is controlled so that the maximum proportion of the amount of water can be stored in the accumulator 41. Next, the ECU 64 detects the vehicle speed based on the vehicle speed signal V from the vehicle speed sensor 73 (step 243).
At the same time, the selected gear of the transmission 3 is detected based on the signal from the gear sensor 68 (step 244). Then, the ECU 64 calculates the synchronous engine rotation speed No. of the engine clutch 2 from the detected vehicle speed and gear position, stores this (step 245), and proceeds to step 246. In step 246, it is determined whether the amount of depression of the brake pedal is equal to or greater than a second predetermined value (for example, 10% of the total amount of depression). This second predetermined value is set to a value slightly smaller than the amount of play of the brake pedal. The amount of depression of the brake pedal is the second predetermined value (10
%), the ECU 64 turns on the brake lamp (stop lamp) 88 (step 256), proceeds to step 257, and detects the selected gear of the transmission 3. . If the selected gear is neutral, engine clutch 2 is left engaged (step 258), and the process returns to the main routine, and if the selected gear is a gear other than neutral, engine clutch 2 is disengaged. (step)
255), return to the main routine. As a result, no matter what position the gear stage is in, the rotation of the wheels 12c, 12c is caused by the propeller shaft 1 as shown in FIG.
2a, main shaft PTO gear 6, drive gear 7
a, 7b, the PTO output shaft 8, the joint 13, and the electromagnetic clutch 14 to the pump motor 16, which drives the pump motor 16 which operates as a pump. Pressure oil generated by the pump motor 16 is stored in an accumulator 41 via a first port 28 and a high pressure oil path 40. At this time, the wheels 12c,
Since the power transmission path from 12c to engine 1 is cut off, almost all of the deceleration energy is transferred to the pump.
It will be used to drive the motor 16. The amount of depression of the brake pedal is the second predetermined value (10
%) or less (step
246), proceeding to step 247, the ECU 64 turns off the brake lamp 88 and then compares the detected engine speed Ne supplied from the electronic governor control unit 86 with the synchronous engine speed No obtained in step 245. (Step 248).
As a result, when the detected engine speed Ne is greater than the synchronous engine speed No, the process proceeds to step 255, where the engine clutch 2 is disengaged and the process returns to the main routine. In this way, even if the amount of depression of the brake pedal is smaller than the second predetermined value (10%),
If the engine speed Ne is larger than the synchronous engine speed No, the wheels 12c, 12c and the engine 1
The power transmission path of the wheels 12c, 12c is cut off, and the wheels 12c, 12c
Almost all of the driving force is transmitted to the pump motor 16, and the deceleration energy is not wasted and the accumulator 4
It will be stored within 1. As a result of the comparison in step 248, if the detected engine speed Ne is equal to or less than the synchronous engine speed No, the process proceeds to step 249, where it is determined whether or not the engine clutch 2 is disengaged.
If the engine clutch 2 is disengaged, the process proceeds to step 250, where the ECU 64 sends a pseudo accelerator signal to the electronic governor control unit 86, causes the electronic governor control unit 86 to inject fuel, and supplies the fuel to the engine 1. Control is performed to increase the amount of fuel and thereby increase the engine speed (step 251). Then, again, the detected engine speed value Ne and the synchronized engine speed
(step 252), and if the detected engine speed Ne is still smaller than the synchronous engine speed No, steps 250 and 251 are repeated, and the engine speed Ne is
Wait until it becomes equal to . Engine speed detection value
When Ne becomes equal to or higher than the synchronous engine speed No., the ECU 64 returns the accelerator signal being supplied to the electronic governor control unit 86 to the true value from the accelerator sensor 65 (step
253), and the engine clutch 2 is brought into contact (step 254). In this way, the engine clutch 2 is engaged after the engine speed is increased so that the engine speed Ne matches the synchronous engine speed No, so the engine clutch 2 can be engaged and operated extremely smoothly and quietly. . In step 249, if the engine clutch 2 is already engaged, the program returns to the main routine without doing anything. In this way, when the amount of depression of the brake pedal is less than the second predetermined value (10%) and the engine speed Ne is equal to or less than the synchronous engine speed No, the deceleration energy is used to drive the pump motor 16. It will be used for both engine braking. When the amount of oil pumped to the accumulator 41 by the pump action of the pump motor 16 exceeds the storage capacity of the accumulator 41, the relief valve 50 opens.
The hydraulic oil is returned to the pressurized oil tank 43 via the relief valve oil passage 49. At this time, the hydraulic oil drives the hydraulic motor 51 disposed in the relief oil passage 49 to rotate the fan 53, and the hydraulic oil itself is also cooled as it passes through the cooler 52. As described above, the fan 53 driven by the hydraulic motor 51 blows air to the cooler 52 to enhance the oil cooling effect of the cooler 52. In the above embodiment, the present invention was applied to a diesel engine.
Of course, there is no problem in applying it to a gasoline engine. In addition, a variable displacement axial piston type pump/motor 16 of the embodiment is used.
Although a motor is used, there is no problem in replacing it with another type. (Effects of the Invention) As described in detail above, according to the vehicle deceleration energy recovery device of the present invention, the countershaft driven via the clutch on the engine side, the main shaft connected to the wheel drive system, and the countershaft are connected to the wheel drive system. A transmission having a multi-stage gear train mechanism that changes the speed and transmits the rotation of the shaft to the main shaft, and a countershaft to the countershaft.
A countershaft PTO gear that is detachably mounted via a PTO gear synchronizer, and a main shaft that meshes with the countershaft PTO gear and is detachably mounted to the main shaft via a main shaft PTO gear synchronizer.
a multi-speed PTO output device having a PTO gear and a PTO output driven via a drive gear meshed with the main shaft PTO gear; a pump motor connected to the PTO output shaft; a high-pressure oil circuit extending from the first port to the accumulator; a low-pressure oil circuit extending from the second port of the pump/motor to the oil tank; and the pump/motor being used as either a pump or a motor depending on the operating state of the vehicle. Since it is equipped with a control means to make it function, there is no need for complicated devices or equipment to recover deceleration energy and use it as starting energy, and the structure is simple.
This has the effect of improving fuel efficiency by recovering deceleration energy and using it for starting energy. Also, a pressurized air supply source connected to the oil tank and supplying pressurized air to the oil tank, an on-off valve disposed in an air passage between the pressurized air supply source and the oil tank, and detecting vehicle speed. vehicle speed sensor,
and switch means for manually turning on and off electric power supplied to at least the multi-stage variable speed PTO output device and the on-off valve via the control means, and the control means detects the power supplied to the vehicle speed sensor by the vehicle speed sensor. When the vehicle speed is substantially zero and the switch means is turned on, the opening/closing valve is opened, thereby preventing cavitation of the low pressure oil circuit during pump/motor deceleration energy recovery operation, and preventing the oil from being cavitated. Since there are no restrictions on where the tank can be installed, space can be used effectively, and pressurized air is supplied to the oil tank only when the deceleration energy recovery device is in operation, so it can be used even when the deceleration energy recovery device is inactive, such as when the engine is stopped. This provides various effects such as minimizing the amount of hydraulic oil leaking from the seal portion of the hydraulic circuit extending from the oil tank to the accumulator, and reducing the drain tank capacity.

[Brief explanation of the drawing]

Fig. 1 is a hydraulic circuit diagram showing an embodiment of the vehicle deceleration energy recovery device according to the present invention, Fig. 2 is a vertical side view of the pump and motor shown in Fig. 1, and Fig. 3 is a diagram of the same pump and motor. FIG. 4 is a longitudinal sectional front view of the capacity control solenoid valve of FIG. 3, and FIG. 5 is a longitudinal sectional side view of the capacity control solenoid valve of FIG. A main flowchart showing the control procedure. FIG. 6 is a flowchart of the solenoid valve A/B control subroutine executed at step 110 of the main flowchart of FIG. 5. FIG. 7 is a flowchart of the main flowchart of FIG. 5. Flowchart of the pressure charge control subroutine executed at 140, FIG.
Flowchart of the start control subroutine executed at step 170 of the main flowchart in the figure.
9 is a flowchart of the motor tilt control subroutine executed at step 220 etc. of the main flowchart of FIG. 5, and FIG. 10 is a flowchart of the speed change control subroutine executed at step 190 etc. of the main flowchart of FIG. 5. The flowchart in Figure 11 is step 240 of the main flowchart in Figure 5.
FIG. 12 is a flowchart of the pump tilting control subroutine executed by the motor tilting control subroutine. A graph showing an example of the relationship with the amount of depression of the accelerator pedal (accelerator opening degree), Fig. 13 shows the pump tilt angle control output from the electronic control unit to the drive circuit of the solenoid valve for capacity control when pump tilt control is executed. A graph showing an example of the relationship between the output value of the signal and the amount of depression of the brake pedal. Fig. 14 is an explanatory diagram of the operation of the deceleration energy recovery device showing the transmission path of the driving force transmitted from the engine to the wheels during steady running of the vehicle. , FIG. 15 is an explanatory diagram of the operation of the deceleration energy recovery device showing the transmission path of the driving force transmitted from the wheels to the pump motor when the vehicle is decelerated;
Figure 16 is an explanatory diagram of the operation of the deceleration energy recovery device showing the transmission path of the driving force transmitted from the engine to the pump motor when the vehicle is stopped, and Figure 17 is the drive transmitted from the pump motor to the wheels when the vehicle is started. FIG. 18 is an explanatory diagram of the operation of the deceleration energy recovery device showing the force transmission path. FIG. be. 1... Engine, 2... Clutch, 3... Transmission, 3'... Multi-speed PTO output device, 4... Main shaft, 5... Counter shaft, 6... Main shaft PTO gear, 7a,
7b... Drive gear, 8... PTO output shaft, 9...
Mainshaft PTO gear synchronizer, 10
... Countershaft PTO gear, 11 ... Countershaft PTO gear synchronizer, 16 ...
... Pump motor, 17, 18 ... Multi-stage gear train mechanism, 30 ... Solenoid valve for capacity control, 32 ... Piston, 40 ... High pressure oil path, 41 ... Accumulator, 42 ... Low pressure oil circuit, 43 ...pressurized tank,
45...Air tank, 46...Solenoid valve, 54...
Supply oil path, 59...Oil pump, 64...Electronic control unit, 65...Accelerator sensor, 66...Brake sensor, 73...Vehicle speed sensor, 78...Main switch, 83...Electronic governor, 84... Fuel injection pump, 86...electronic governor control unit, 90...rpm sensor.

Claims (1)

[Claims] 1. A transmission comprising a countershaft driven via a clutch on the engine side, a mainshaft connected to a wheel drive system, and a multi-stage gear train mechanism that changes speed and transmits rotation of the countershaft to the mainshaft. A countershaft PTO gear that is detachably attached to the countershaft via a countershaft PTO gear synchronizer meshes with the countershaft PTO gear and is connected to the main shaft.
A multi-stage variable speed type that has a main shaft PTO gear that can be connected and disconnected via a PTO gear synchronizer, and a PTO output shaft that is driven via a drive gear meshed with the main shaft PTO gear.
a PTO output device, a pump motor connected to the PTO output shaft, a high pressure oil circuit extending from a first port of the pump motor to an accumulator, and a low pressure oil circuit extending from a second port of the pump motor to an oil tank. , a pressurized air supply source connected to the oil tank and supplying pressurized air to the oil tank, an on-off valve disposed in an air passage between the pressurized air supply source and the oil tank, and detecting vehicle speed. A vehicle speed sensor, a control means for causing the pump/motor to function as either a pump or a motor depending on the operating state of the vehicle, and supplying power to at least the multi-speed PTO output device and the on-off valve via the control means. Turn on/off the power by manual operation.
The control means is provided with a switch means for turning off, and the control means opens the on-off valve when the vehicle speed detected by the vehicle speed sensor is substantially zero and the switch means is in the on state. Features: Vehicle deceleration energy recovery device.