JP6343750B2 - Forklift hybrid drive system - Google Patents

Description

The present invention relates to a hybrid drive device for a forklift that connects a hydraulic pump via a PTO (output) shaft of an engine or a transmission and drives a working device including a cargo handling device by the hydraulic pressure obtained by the hydraulic pump.

  Patent Document 1 includes a motor / generator for supplying power to a battery on a PTO (output) shaft of a transmission, and a generator / motor that is driven by the battery and drives a hydraulic pump. A drive device is disclosed in which a clutch is interposed on a rotating shaft that couples the motor and the generator-cum-motor to allow connection and separation.

Japanese Patent No. 4680769

  In the above configuration, with the clutch disengaged (off), the generator is driven by the PTO shaft to charge the battery. In addition, the generator is driven by the electric power of the battery and the engine is assisted by the PTO shaft. Further, while the engine is kept idling, the motor / generator is driven by the engine and the battery is charged, and the pump is driven by supplying power from the battery to the generator / motor to drive the working device.

  Further, with the clutch connected (turned on), the motor / generator and the generator / motor are idled, the pump is driven by the engine, and the working device is driven. In addition, the power generator from the battery drives the motor-generator and the generator-generator motor to drive the pump.

  However, in the above configuration, the PTO shaft must be equipped with two motors / generators composed of a motor combined generator and a generator combined motor, and the occupied volume of the drive unit equipped with the transmission is widely required. There was a problem that the limited housing space of the drive unit could not be effectively used.

SUMMARY OF THE INVENTION An object of the present invention is to provide a forklift hybrid drive device that can solve the above-described problems and make the drive device compact.

The invention according to claim 1 is a hydraulic pump driven by an engine to generate hydraulic pressure, a working device driven by the hydraulic pressure, a first power supply device charged by a generator driven by the engine, and an engine or A first clutch, an assist motor / generator and a second clutch, which are sequentially connected between a PTO shaft provided in the transmission and a drive shaft of the hydraulic pump, and a second clutch that is charged and powered by the assist motor / generator. A forklift hybrid drive device comprising: a power supply device; and an assist controller that selectively operates a first clutch, an assist motor / generator, a second clutch, and a second power supply device,
Selection assist controller during handling, in response to a vehicle controller of the data, and the power assist to the engine or hydraulic pump according to the assist motor / generator, a power regeneration from A Shisutomota / generator to a second power supply, the Done
An assist unit in which the first clutch, the assist motor / generator, and the second clutch are integrally incorporated in the unit case is connected to the PTO shaft and is detachably incorporated in the engine unit. The rotating shaft with the second clutch interposed from the generator is connected to the drive shaft of the hydraulic pump .

The invention of claim 2 is the hybrid drive device of the forklift according to claim 1,
The assist controller
When the input value from the accelerator is greater than or equal to the specified value in the operating state of the work device, the first clutch and the second clutch are connected respectively, and the assist motor / generator is fed from the second power supply device and driven to drive the engine and Select the cargo handling / power assist mode to drive the hydraulic pump to assist the power,
In operation state of the working device, is less than the input value is a specified value from the accelerator, and with a brake is actuated state, when the assist motor / generator is equal to or higher than the predetermined rotational speed, connects the first and second clutches, respectively Then , select a cargo handling / power regeneration mode in which the regenerative power generated by the assist motor / generator is stored in the second power supply device ,
When the input value from the accelerator is less than the specified value in the operating state of the work device and the brake is inactive, the engine load is reduced by separating the first clutch, and the second clutch is connected to the second clutch. It is characterized by selecting a cargo handling / load reduction mode in which an assist motor / generator is driven by a two-power supply device and power is assisted by a hydraulic pump.

According to the first aspect of the present invention, the assist motor / generator is interposed between the PTO shaft and the hydraulic pump, the first clutch is interposed between the PTO shaft and the assist motor / generator, and the assist motor / power generation is performed. Since the second clutch is interposed between the engine and the hydraulic pump, the power transmitted from the engine to the assist motor / generator can be connected and separated by the first clutch and the second clutch. / The power transmitted to the generator and hydraulic pump can be connected and disconnected. As a result, the assist mode can be set according to the environment when the forklift is started, traveled, and handled, and a single assist motor / generator can be used, so that the drive device can be made compact.
Furthermore, by assembling the first clutch, the assist motor / generator, and the second clutch into the unit case as one body, the assembling performance and the maintenance performance can be improved and can be provided at low cost .

According to the second aspect of the invention, the power assist of the engine can be effectively performed by the cargo handling / power assist mode. Also, due to the cargo handling / load reduction mode, when the cargo handling operation was performed at a low engine speed in the past, there was a case where the engine stalled due to insufficient torque, but even when the accelerator is off, the cargo handling operation can be performed without stalling. can do. Since the assist motor / generator is driven by the second power supply device to assist the power of the hydraulic pump, the load on the engine is reduced. Furthermore, by the cargo handling / power regeneration mode, the regenerative power by the assist motor / generator can be effectively recovered.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a structural diagram showing a first embodiment of a forklift equipped with a hybrid drive device according to the present invention. It is a block diagram of a hybrid type drive device. It is a flowchart explaining the assist mode at the time of starting. It is a flowchart explaining the assist / electric power regeneration mode at the time of driving | running | working. It is a flowchart explaining the assist / electric power regeneration mode at the time of cargo handling. It is a flowchart explaining the demand control of power steering. It is a schematic block diagram which shows the principal part of a hybrid type drive device. It is structural drawing which shows Example 2 of the forklift which comprised the hybrid type drive device which concerns on this invention.

Example 1 according to the present invention, is provided with a driving / regeneration assist mechanism (assist mechanism) in forklifts.

  In this forklift, the power of the engine E is transmitted through the torque converter TC and the transmission TM, and the traveling device 13 that drives the left and right rear wheels RW as drive wheels through the drive differential DD, and the PTO shaft 12 of the engine E A hydraulic pump GP connected through the hydraulic pump GP, a cargo handling device 14 driven by the hydraulic pressure of the hydraulic pump GP, and a first power supply device (for example, a lead battery) charged via a generator EG driven by the engine E 16.

  A part of the hydraulic pressure generated by the hydraulic pump GP is lifted by a lift cylinder 17C of a lift device 17G that lifts and lowers a cargo handling fork 17B via a cargo handling control valve 17A that constitutes a cargo handling device 14 that is an example of a working device, It is supplied to a tilt cylinder 17E for tilting the guide mast device 17D of the fork 17B and various attachment cylinders 17F. Further, part of the hydraulic pressure of the hydraulic pump GP is supplied to the steering cylinder 18B of the left and right front wheels FW, which are the steering wheels, via a steering valve (for example, an orbit roll) 18A constituting the steering device. Further, a part of the hydraulic pressure of the hydraulic pump GP is accumulated in the hydraulic accumulator 19A and supplied from the brake valve 19B to the brake cylinder 19C of a hydraulic brake device (for example, a disc brake).

  The vehicle controller 31 controls the engine E and vehicle auxiliary equipment via the engine control unit 32, and at least a travel shift lever detector 33 for detecting the neutral, forward, and reverse operation positions of the travel shift lever, an accelerator pedal. An accelerator sensor 34 that detects the amount of depression of the steering wheel, a steering sensor 35 that detects the operating angle of the steering wheel, a cargo handling operation switch 36 that outputs operation signals of the lift cylinder 17C, the tilt cylinder 17E, and the attachment cylinder 17F, and the amount of operation of the brake pedal. Brake switch 37 for output, engine start switch 38 for operating starter motor Es for starting engine E, first power supply voltage sensor 39 for outputting voltage of first power supply device 16, and coolant temperature of engine cooling radiator Output The signals from the radiator liquid temperature sensor 40, the operation signal is input.

(Drive / Regenerative assist mechanism)
The drive / regenerative assist mechanism 11 includes an assist motor / generator 21 interposed between a PTO shaft 12 provided in the engine E and a hydraulic pump GP, and a rotating shaft of the PTO shaft 12 and the assist motor / generator 21. An electromagnetic or hydraulic first clutch 22 interposed therebetween, and an electromagnetic or hydraulic second clutch 23 interposed between the rotating shaft of the assist motor / generator 21 and the drive shaft of the hydraulic pump GP; In response to the output data of the second power supply device (lithium battery / capacitor) 25 that can be charged / powered to the assist motor / generator 21 via the inverter 24 and the vehicle controller 31, the first clutch 22 and the second clutch 23, the charging / power feeding to the second power supply device 25, the power feeding to other devices, and the operation of the assist motor / generator 21 are selectively performed. Cysts / regenerative controller (assist controller) 20, which detects the voltage of the second power supply unit 25 and a second power supply voltage sensor 27 that outputs the assist / regeneration controller 20.

  The assist / regenerative controller 20 is at least one of at the time of start-up, traveling, and cargo handling, and assists power to the engine E and the hydraulic pump GP by the assist motor / generator 21, stores regenerative power, and the second power supply device 25. Assist with power.

  According to the above configuration, the assist motor / generator 21 is interposed between the PTO shaft 12 and the hydraulic pump GP, the first clutch 22 is interposed between the PTO shaft 12 and the assist motor / generator 21, and the assist motor. / Because the second clutch 23 is interposed between the generator 21 and the hydraulic pump GP, the power transmitted from the engine E to the assist motor / generator 21 is connected by the first clutch 22 and the second clutch 23. The power transmitted to the assist motor / generator 21 and the hydraulic pump GP can be connected and separated. As a result, a plurality of assist / power regeneration modes can be set according to the environment in the forklift starting, running, and cargo handling states, and a single assist motor / generator 21 is required, so that the drive device is configured compactly. be able to.

  As shown in FIG. 7, the first clutch 22, the assist motor / generator 21, and the second clutch 23 are integrated into a unit case 26a, and an assist unit 26 is formed in which respective shafts are connected to each other. ing. In the engine unit, the assist unit 26 is detachably incorporated between the PTO shaft 12 and the drive shaft of the hydraulic pump GP.

As described above, the assist unit 26 in which the first clutch 22, the assist motor / generator 21, and the second clutch 23 are integrally incorporated in the unit case 26 a allows the drive / regenerative assist mechanism 11 to be used not only for new vehicles but also for currently used vehicles. Additional equipment is available. In addition, the assist unit 26 can be removed along with the unit case 26a during maintenance, or the assist unit 26 can be replaced along with the unit case 26a during a failure. Therefore, the unitization of the drive / regeneration assist mechanism 11 can improve the assembly performance and maintenance performance, and can be provided at low cost.

Next, with reference to the flowcharts of FIGS. 3 to 6, each mode at the time of start-up, travel, and cargo handling will be described.
(Startup mode)
As shown in FIG. 3, when the vehicle controller 31 satisfies the start condition (STEP. S1), it is confirmed by the signal of the travel shift lever detector 33 that the travel shift lever is in the neutral position (STEP. After S2), the engine start switch 38 is turned on (STEP.S3).

  Next, it is determined whether or not the voltage of the second power supply device 25 detected by the second power supply voltage sensor 27 is equal to or higher than a specified value (STEP. S4). If the voltage of the second power supply device 25 is less than the specified value, The normal start mode is entered, and the engine control unit 32 supplies the power of the first power supply device 16 to the starter motor Es to start the engine E (STEP. S10).

  When the voltage of the second power supply device 25 is equal to or higher than a specified value, the coolant / coolant liquid temperature input from the radiator liquid temperature sensor 40 via the vehicle controller 31 by the assist / regenerative controller 20 is less than the specified value, Whether or not is judged (STEP.S5). If the coolant temperature of the radiator is below the specified value, the assist / regenerative controller 20 selects the “startup / power assist mode” (STEP. S7).

  When the coolant temperature of the radiator is equal to or higher than the specified value, the assist / regenerative controller 20 then determines whether the voltage of the first power supply device 16 detected by the first power supply voltage sensor 16s is less than the specified value. (STEP.S6). When the voltage of the first power supply device 16 is less than the specified value, the assist / regenerative controller 20 selects “start-up / power assist mode” (STEP. S8), and when the voltage of the first power supply device 16 is equal to or higher than the specified value, Select “Startup / Load Reduction Mode” (STEP.S9).

  In the “startup / power assist mode” (STEP.S7), the first clutch 22 is connected (ON), the second clutch 23 is disconnected (OFF) (STEP.S7a), and power is supplied from the second power supply 25. Then, the assist motor / generator 21 is driven to assist the power of the engine E (STEP. S7b), and the power of the first power supply device 16 is supplied to the starter motor Es to start the engine E (STEP. S10).

  In the “startup / power assist mode” (STEP.S8), the first clutch 22 is disconnected (OFF) (STEP.S8a). At this time, the second clutch 23 is in an arbitrary position. Then, by turning on the engine start switch 38, the electric power of both the second power supply device 25 and the first power supply device 16 is supplied to the starter motor Es to assist the power (STEP.S8b), and the engine E is started (STEP. .S10).

  In the “startup / load reduction mode” (STEP.S9), the first clutch 22 is disconnected (OFF) (STEP.S9a). At this time, the second clutch 23 is in an arbitrary position. Thereby, while reducing the load (rotational resistance) of the engine E and the hydraulic pump GP, the power of the first power supply device 16 is supplied to the starter motor Es to start the engine E (STEP. S10).

  In the “start-up / power assist mode” (STEP. S7) and “start-up / power assist mode” (STEP. S8), when the charge amount of the first power supply device 16 is reduced, the subsequent running mode In the cargo handling mode, the generator E can be driven by the engine E to charge the first power supply device 16 and travel and cargo handling can be performed. The first power supply device 16 can be charged by the second power supply device 25.

  According to the start mode, when the engine E is started, it is determined whether or not the second power supply device 25 is charged with a voltage having a specified value that can be assisted. If the voltage is less than the specified value, the normal start operation is performed. Therefore, power assist and power assist when the engine E is started can be reliably performed.

  The “startup / power assist mode” selected when the voltage of the second power supply device 25 is equal to or higher than the specified value and the coolant temperature of the radiator is lower than the specified value drives the engine E by the assist motor / generator 21. By driving the starter motor Es by the first power supply device 16 and starting the engine E while assisting the power, the engine E can be surely started even in a cold region or winter where the outside air temperature is low. it can.

  Further, according to the “start-up / power assist mode” selected when the coolant temperature of the radiator is equal to or higher than a specified value and the voltage of the first power supply device 16 is less than the specified value, the second power supply device 25 By driving the starter motor Es with the first power supply device 16 and the second power supply device 25 with power assistance, the engine E can be reliably started.

Furthermore, the “start-up / selection” is selected when the voltage of the second power supply device 25 is equal to or higher than the specified value, the coolant temperature of the radiator is higher than the specified value, and the voltage of the first power supply device 16 is higher than the specified value. According to the “load reduction mode”, the engine E can be started smoothly by separating the first clutch 22 and reducing the load on the engine E due to the rotational resistance of the assist motor / generator 21 and the hydraulic pump GP. .
(Driving mode)
As shown in FIG. 4, the engine E is in a starting state (STEP.R1 = S10), and in the assist / regenerative controller 20, the cargo handling operation such as the lift operation, the tilt operation, and the attachment operation is not operated by the cargo handling operation switch 36. Whether or not is determined (STEP.R2). When the cargo handling operation is not performed, it is determined whether or not the accelerator input value detected by the accelerator sensor 34 is less than the specified value (STEP.R3). If the accelerator input value is equal to or greater than the specified value, the assist / regenerative controller 20 selects “driving / power assist mode” (STEP.R4).

  If the accelerator input value is less than the specified value, the assist / regenerative controller 20 determines whether or not the brake is operated by the brake switch 37 (STEP.R5). When the brake is not operated, the assist / regeneration controller 20 selects the “travel / load reduction mode” (STEP.R6).

  In the ON state where the brake is operated, the assist / regenerative controller 20 determines whether the rotational speed is equal to or higher than a specified value by the rotary encoder 20e provided in the assist motor / generator 21 (STEP.R7 ). If the rotation speed of the assist motor / generator 21 is equal to or higher than the specified value, the assist / regeneration controller 20 selects the “travel / power regeneration mode” (STEP.R8), and the rotation speed of the assist motor / generator 21 is When the value is less than the specified value, the “travel / load reduction mode” is selected (STEP.R6). This is because when the rotational speed of the assist motor / generator 21 is less than a specified value and the “running / power regeneration mode” is selected, the engine E becomes less than the idle rotational speed, causing engine stalling and improper control. Because it becomes. This is because the hydraulic pressure for steering is also required.

  In the “running / power assist mode” (STEP.R4), the first clutch 22 and the second clutch 23 are each connected (ON) (STEP.R4a). Then, power is supplied from the second power supply device 25 to the assist motor / generator 21 to drive the power to assist the engine E (STEP. R4b). In the power assist control, a constant torque may be assisted at a constant rotational speed, or the rotational torque may be changed. The hydraulic pressure generated by the hydraulic pump GP is supplied from the steering valve 18A to the steering cylinder 18B and used for power steering.

  In the “travel / load reduction mode” (STEP.R6), the first clutch 22 is disconnected (OFF) (STEP.R6a), and the PTO shaft 12 and the rotating shaft of the assist motor / generator 21 are separated from each other. The rotational resistance of the assist motor / generator 21 and the hydraulic pump GP at E is reduced. In this “travel / load reduction mode”, the power steering demand control shown in FIG. 6 is performed (STEP.R6b). That is, when the second clutch 23 is connected (ON) (STEP.R6a), the steering handle is operated, and the operation of the steering valve 18A is detected by the steering sensor 35 (STEP.R6c), the second power supply 25 The assist motor / generator 21 is powered and driven (STEP.R6d), and the pressure oil generated by the hydraulic pump GP is supplied from the steering valve 18A to the steering cylinder 18B by an amount necessary for steering (STEP.R6e). .

  In the “running / power regeneration mode” (STEP.R8), the first clutch 22 and the second clutch 23 are respectively connected (turned on) (STEP.R8a). As a result, the power of the engine E is transmitted to the assist motor / generator 21, and the rotation speed of the assist motor / generator 21 is equal to or higher than a specified value. Is stored in the second power supply device 25 (STEP.R8b).

  Here, when the rotation speed of the assist motor / generator 21 becomes less than the specified value, it will be changed via (B) ⇒ (STEP.R2) ⇒ (STEP.R3) ⇒ (STEP.R5) ⇒ (STEP.R7) Moves to "Running / load reduction mode" (STEP.R6).

  In the travel mode, according to the “travel / load reduction mode” selected when the accelerator input value is less than the specified value and the brake is not operated, the first clutch 22 is engaged when the forklift travels. When the power steering is operated by separating (off) the PTO shaft 12 and the assist motor / generator 21, a hydraulic pump is driven by the assist motor / generator to supply a necessary amount of pressure oil to the steering valve. This is dealt with by demand control supplied from 18A to the steering cylinder 18B. Thereby, the load of the engine E resulting from the rotational resistance of the assist motor / generator 21 and the hydraulic pump GP can be eliminated, and the vehicle can travel efficiently.

  Further, according to the “running / power assist mode” that is selected when the accelerator is depressed more than a specified value and the rotational speed of the engine E is sufficiently higher than the specified value, the engine E is assisted by the assist motor / generator. , Can drive efficiently.

  Further, it is selected when the accelerator depression amount is less than the specified value and the engine E is not high in speed, the brake is not operated, and the speed of the assist motor / generator 21 is equal to or higher than the specified value. According to the “running / power regeneration mode”, the regenerative power of the assist motor / generator 21 driven by the engine E can be stored in the second power supply device 25, and the vehicle can travel efficiently.

(Handling mode)
As shown in FIG. 5, in the assist / regenerative controller 20, when a lift operation, a tilt operation, an attachment operation, etc. are turned on by the cargo handling operation switch 36 and the cargo handling operation state is determined (STEP.R2), It is determined whether or not the accelerator input value detected by the accelerator sensor 34 is less than a specified value (STEP.W1). When the input value of the accelerator is equal to or greater than the specified value, the assist / regeneration controller 20 selects the “load handling / power assist mode” (STEP.W2).

  When the accelerator input value is less than the specified value (STEP.W1), the assist / regenerative controller 20 determines whether or not the brake is operated by the brake switch 37 (STEP.W3). When the brake is off, for example, when the engine E is idling or rotating at a low speed and the forklift is slowly moving forward or backward, the assist / regenerative controller 20 selects the “load handling / load reduction mode” (STEP.W6).

  When the brake switch 37 is turned on and the forklift is about to stop (STEP.W3), the assist / regenerative controller 20 determines whether the rotational speed of the assist motor / generator 21 is equal to or higher than a specified value by the rotary encoder 21e. (STEP.W5). When the rotation speed of the assist motor / generator 21 is equal to or higher than a specified value, the assist / regeneration controller 20 selects “travel / power regeneration mode” (STEP.W6). On the other hand, when the assist motor / generator 21 has a rotational speed less than the specified value, the assist / regeneration controller 20 selects the “running / load reduction mode” (STEP.W4). Here, if the rotation speed of the assist motor / generator 21 is less than the specified value and the “loading / power regeneration mode” is selected, the engine E becomes less than the idle rotation speed, which causes engine stall.

  In the “loading / power assist mode” (STEP.W2), the first clutch 22 and the second clutch 23 are connected (ON) (STEP.W2a). Electric power is supplied from the second power supply device 25 to drive the assist motor / generator 21 to assist the power of the engine E and drive the hydraulic pump GP (STEP.W2b). In the assist control by the assist motor / generator 21, a constant torque may be supplied to the engine E at a constant rotational speed, or the rotational torque may be changed.

  In the “loading / load reduction mode” (STEP.W4), the first clutch 22 is separated (off) and the second clutch 23 is connected (on) (STEP.W4a). Then, power is supplied from the second power supply device 25 to drive the assist motor / generator 21 to power assist the hydraulic pump GP (STEP. W4b). Conventionally, when the cargo handling apparatus 14 is operated while the engine E is idling, the engine speed is low and sometimes the engine stalls due to insufficient torque. However, even if the engine E is idling, the cargo handling apparatus 14 The cargo handling work can be performed without operating the engine and causing it to stall.

  In the “loading / power regeneration mode” (STEP.W6), the first clutch 22 and the second clutch 23 are respectively connected (turned on) (STEP.W6a). As a result, the assist motor / generator 21 is driven by the power of the engine E, and regenerative power is supplied to the second power supply device 25 via the inverter 24 in a range where the rotation speed of the assist motor / generator 21 is equal to or greater than a specified value. To store electricity (STEP.W6b).

Here, when the rotation speed of the assist motor / generator 21 is less than the specified value, the “loading / load reduction mode” is established via (B) ⇒ (STEP.R2) ⇒ (STEP.W1) ⇒ (STEP.W3). Moved to (STEP.W4).
According to the “load handling / power assist mode” selected by the assist / regenerative controller 20 when the input value of the accelerator is equal to or greater than a specified value, the second power supply device with the first clutch 22 and the second clutch 23 connected. Power is supplied from 25 to drive the assist motor / generator 21 to assist the power of the hydraulic pump GP. Thereby, the cargo handling apparatus 14 can be driven with big motive power.

  Further, when the input value of the accelerator is less than the specified value and the brake is inactive (off), or the brake is activated and the forklift is stopped, and the rotational speed of the assist motor / generator 21 is When the value is less than the specified value, the “load handling / load reduction mode” is selected by the assist / regeneration controller 20. According to the “load handling / load reduction mode”, the first clutch 22 is separated (off) and the assist motor / generator 21 is driven to drive the hydraulic pump while the second clutch 23 is connected (on). Power assist the GP. Thereby, cargo handling work can be performed while maintaining the quiet state of the engine E, and generation of noise from the engine E can be effectively suppressed.

Further, the assist / regenerative controller 20 is in an idling state where the accelerator input value is less than a specified value, the brake is activated, the forklift is about to stop, and the rotation speed of the assist motor / generator 21 is less than the specified value. Selects “Handling / load reduction mode”. According to this “load handling / load reduction mode”, the first clutch 22 is disengaged (off) and the second clutch 23 is connected (on) to reduce the load on the engine E and drive assist motor / power generation The machine 21 is driven to assist the power of the hydraulic pump GP. As a result, when the engine E performs a cargo handling operation while traveling at a low speed, the cargo handling device 14 can be operated to perform the cargo handling operation without being stalled even if the engine is rotating at a low speed or in an idling state. . Since the assist motor / generator is driven by the second power supply device to assist the power of the hydraulic pump, the load on the engine is reduced. Moreover, noise can be effectively suppressed.
According to the “loading / power regeneration mode”, the assist motor / generator 21 is driven by the power of the engine E by connecting (turning on) the first clutch 22 and the second clutch 23, and the regenerative power is converted into an inverter. 24 can be stored in the second power supply device 25.

[Example 2]
In the first embodiment, the assist motor / generator 21 is interposed between the PTO shaft 12 having the PTO shaft 12 provided in the engine E and the drive shaft of the hydraulic pump GP via the first and second clutches 22 and 23. However, in the second embodiment, as shown in FIG. 8, the assist motor / power generation is performed via the first and second clutches 22 and 23 between the PTO shaft 12 and the hydraulic pump GP provided in the transmission TM. A machine 21 is provided. Note that the same members as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  According to the second embodiment, the same effects as those of the first embodiment can be achieved.

GP Hydraulic pump E Engine EG Generator Es Starter motor TM Transmission 11 Drive / regenerative assist mechanism (assist mechanism)
12 PTO shaft 13 traveling device 14 cargo handling device 15 generator 16 first power supply device 17A cargo handling control valve 18A steering valve 18B steer cylinder 19B brake valve 20 assist / regenerative controller (assist controller)
21 assist motor / generator 22 first clutch 23 second clutch 24 inverter 25 second power supply device 26 assist unit 26a unit case 27 second power supply voltage sensor 31 vehicle controller 32 engine control unit 33 travel shift lever detector 34 accelerator Sensor 35 Steering sensor 36 Cargo handling switch 37 Brake switch 38 Engine start switch 39 First power supply voltage sensor 40 Radiator liquid temperature sensor

Claims (2)

From a hydraulic pump driven by an engine to generate hydraulic pressure, a working device driven by the hydraulic pressure, a first power supply device charged by a generator driven by the engine, and a PTO shaft provided in the engine or transmission A first clutch and an assist motor / generator and a second clutch sequentially connected to a drive shaft of the hydraulic pump; a second power supply device charged and powered by the assist motor / generator; A forklift hybrid drive device comprising: an assist motor / generator, an assist controller for selectively operating a second clutch and a second power supply;
Selection assist controller during handling, in response to a vehicle controller of the data, and the power assist to the engine or hydraulic pump according to the assist motor / generator, a power regeneration from A Shisutomota / generator to a second power supply, the Done
An assist unit in which the first clutch, the assist motor / generator, and the second clutch are integrally incorporated in the unit case is connected to the PTO shaft and is detachably incorporated in the engine unit. A hybrid drive device for a forklift characterized in that a rotary shaft with a second clutch interposed from a generator is connected to a drive shaft of a hydraulic pump . A hybrid drive device for a forklift according to claim 1,
The assist controller
When the input value from the accelerator is greater than or equal to the specified value in the operating state of the work device, the first clutch and the second clutch are connected respectively, and the assist motor / generator is fed from the second power supply device and driven to drive the engine and Select the cargo handling / power assist mode to drive the hydraulic pump to assist the power,
In operation state of the working device, is less than the input value is a specified value from the accelerator, and with a brake is actuated state, when the assist motor / generator is equal to or higher than the predetermined rotational speed, connects the first and second clutches, respectively Then , select a cargo handling / power regeneration mode in which the regenerative power generated by the assist motor / generator is stored in the second power supply device ,
When the input value from the accelerator is less than the specified value in the operating state of the work device and the brake is inactive, the engine load is reduced by separating the first clutch, and the second clutch is connected to the second clutch. A forklift hybrid drive device , wherein a load handling / load reduction mode in which an assist motor / generator is driven by a two-power supply device to assist the hydraulic pump in power is selected .

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