JP2009241830A - Traveling working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a traveling working vehicle provided with a motive power transmission structure capable of improving energy efficiency in a whole of a system, controlling acceleration/deceleration of advancement/retreating by a simple structure, attaining the most efficient engine driving even viewed from an aspect of fuel consumption of an engine and an exhaust gas and further efficiently distributing working machine motive power and traveling motive power without speed-change shock at a real time. <P>SOLUTION: A first power generation motor 3 is provided so as to be directly connected to an engine 2, and a shaft B of the first power generation motor 3 is connected to a shaft C of a hydraulic pump system 6 and is connected to a planetary gear mechanism 5. A shaft of a second power generation motor 4 is connected to the planetary gear mechanism 5, and a shaft E of the planetary gear mechanism 5 is connected to a wheel drive system 10. A use mode of the first power generation motor 3 and the second power generation motor 4 is controlled according to the number of revolution of the engine, a traveling mode of the traveling working vehicle and the rotation number of the shaft E. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a traveling work vehicle such as a wheel loader, and more particularly, to a traveling work vehicle that is hybridized by combining power from an engine and power from an electric motor as a drive source in the traveling work vehicle.

  2. Description of the Related Art Conventionally, in a traveling work vehicle such as a wheel loader, a configuration in which a working machine such as a boom or a bucket and a traveling body such as a wheel are operated using an engine as a driving source is known as a general configuration. For example, a wheel loader is used in a combination of a start / stop pattern in traveling, a soil sanding pattern by a work machine, and a pattern such as earth lifting and soil removal. Moreover, these combined patterns are repeated within a short time cycle.

  As a result, the engine as the power source is controlled in accordance with a severe variable load, and therefore the engine output torque and the engine speed are frequently adjusted. In addition, the engine rotational speed and the engine output torque must be adjusted in accordance with the severe fluctuating load, which hinders deterioration of fuel consumption and suppression of exhaust gas.

  On the other hand, in recent years, attempts have been made to reduce the load fluctuation applied to the engine by combining the power from the engine as the drive source of the traveling work vehicle with the power from the electric motor to achieve a hybrid.

  As a hybrid work vehicle, the conventional wheel loader uses a torque converter or HST circuit to distribute power to the work machine pump and the drive transmission via a torque converter or HST circuit. In particular, there has been proposed a hybrid construction vehicle (see Patent Document 1) in which only the traveling side having a large required power is electrified. In addition, a hybrid drive type wheel system work vehicle (see Patent Document 2) in which an electric motor as a power source for a work machine and an electric motor as a power source for traveling are separately provided has been proposed. .

  Furthermore, the continuously variable transmission that changes the output from the engine is composed of two electric motors and three planetary speed reducers, and the power can be switched as required from low speed to high speed. A transmission (see Patent Document 3) and two electric motors that also act as a generator are arranged on the output shaft of the engine, and the two electric motors and one planetary speed reducer constitute a continuously variable transmission. Hybrid vehicles (see Patent Document 4) have been proposed.

  The hybrid construction vehicle described in Patent Document 1 is shown as a conventional example 1 according to the present invention, and FIG. 15 shows an overall configuration diagram of the hybrid construction vehicle. As shown in FIG. 15, the power output from the engine 50 is distributed through a power distribution mechanism 55 to drive a hydraulic pump 51 for a work machine actuator and a generator 52 that converts it into electric energy.

  The electric energy generated by the generator 52 is charged in the battery 54, and the electric power from the battery 54 is supplied to the motor 53 as traveling power. Further, since the battery 54 can function as a buffer in the electric energy mode, the battery 54 can absorb a violent power fluctuation load required when the construction vehicle travels. Therefore, the output fluctuation of the engine 50 can be leveled. Further, by providing the clutch 56 on the output shaft of the engine 50, it is possible to perform idling stop.

  The hybrid drive wheel system work vehicle described in Patent Document 2 is shown as a conventional example 2 according to the present invention, and FIG. 16 shows an overall configuration diagram of the hybrid drive wheel system work vehicle. As shown in FIG. 16, an electric motor 61 as a power source for the work machine and an electric motor 62 as a power source for traveling are separately provided. Drive energy from the engine 60 is converted into electric energy by the generator 63 and the battery 64 is charged. The electric motor 61 and the electric motor 62 are driven by the electric energy charged in the battery 64.

  As described above, since the electric motor 61 for the working machine and the electric motor 62 for traveling can be controlled as completely independent power sources, only the necessary power is taken out from the battery 64 regardless of the operating conditions. Can be used. The engine 60 can be operated under optimum conditions both in terms of fuel consumption and exhaust gas. Further, the regenerative energy from the work machine and the regenerative energy from the traveling power can be stored in the battery 64 by using the electric motors 61 and 62 as generators.

  The electromechanical transmission described in Patent Document 3 is shown as a conventional example 3 according to the present invention, and FIG. 17 shows an overall configuration diagram of the electromechanical transmission. As shown in FIG. 17, the driving force from the engine 70 is taken out from the output shaft 71 via the continuously variable transmission and used as the driving force for running the vehicle. The continuously variable transmission consists of two generator-motors 72, 73 and three planetary speed reducers 74, 75, 76, allowing the vehicle to switch speeds as required from low speed to high speed. ing.

The hybrid type vehicle described in Patent Document 4 is shown as a conventional example 4 according to the present invention, and FIG. 18 shows an overall configuration diagram of the hybrid type vehicle. As shown in FIG. 18, two electric motors 82 and 83 that also act as a generator are arranged on the output shaft 81 of the engine 80, and the two electric motors 82 and 83 and one planetary speed reducer 84 are stepless. It constitutes a transmission.
Since it is configured in this way, acceleration / deceleration control when the hybrid vehicle moves forward / backward is controlled freely by the control of the two electric motors 82 and 83 while maintaining a mode in which the engine speed is kept constant. It becomes possible to do.
JP 2005-133319 A JP 2006-233843 A JP 2000-108693 A JP 05-281542 A

  A traveling work vehicle such as a wheel loader requires a very large traveling power during excavation. That is, during digging, a large traction force with a large torque is required while traveling at a low speed. Therefore, in the hybrid construction vehicle and the wheel system work vehicle shown in Patent Documents 1 and 2, it is inevitable to increase the size of the electric motor when attempting to obtain a large traction force while performing low-speed traveling.

  Furthermore, in order to satisfy the demand for large torque, it is desirable to increase the size in the radial direction as compared with the size in the axial direction as the configuration of the rotor in the electric motor. However, on the other hand, it is necessary to rotate the electric motor at high speed when the traveling work vehicle is cruising. For this purpose, the rotor of the electric motor is configured to be long in the axial direction and small in the radial direction. This is a desirable configuration.

  In this way, contradictory circumstances occur which are mutually contradictory in the motor design. Therefore, in the hybrid construction vehicle and the wheel system work vehicle shown in Patent Documents 1 and 2, if priority is given to taking out large torque at low speed, it becomes difficult to satisfy the maximum speed during cruise traveling. Have a problem.

  That is, the hybrid construction vehicle of Patent Document 1 has a configuration in which traveling power is provided by a single electric motor 53. For this reason, the electric motor 53 must have both characteristics such that a large torque can be output at a low speed and a high-speed rotation can be performed at a high speed. In order to satisfy both of these characteristics, the electric motor 53 must have a very large configuration.

  Further, in the wheel system work vehicle disclosed in Patent Document 2, as in the case of the hybrid construction vehicle disclosed in Patent Document 1, the traveling power motor must be configured to be large. Moreover, since the electric motor 61 is separately provided for the work machine, the electric motor 61 that is not used at all other than when the work machine is driven is mounted. For this reason, it is necessary to provide a wide space for mounting the electric motors 61 and 62, and the cost of the on-vehicle equipment is greatly increased.

  Further, in the wheel system work vehicle of Patent Document 2, all of the drive output from the engine 60 is converted into electric energy by the generator 63 and the battery 64 is charged. The electric power charged in the battery 64 is used as electric power for driving the electric motor 61 for operating the work implement and the electric motor 62 for traveling. For this reason, when the wheel system work vehicle of patent document 2 is seen from the surface of the energy utilization efficiency in the whole system, the problem that the energy utilization efficiency in the whole system will fall has arisen. Moreover, this problem has become such a big problem that it cannot be ignored.

  As means for solving the problems in the hybrid construction vehicle and wheel work vehicle shown in Patent Documents 1 and 2, as shown in Patent Documents 3 and 4, the driving power from the engine is combined with the power from the electric motor. A continuously variable transmission has been proposed.

  In the traveling work vehicle having the electromechanical transmission shown in Patent Document 3, clutch engagement from the low speed range to the medium speed range that is most frequently used is inevitable, and the number of clutch engagements is increased every time the gear shift is performed. Become more. Further, since the clutch is frequently engaged during the work, the life of the clutch is deteriorated in addition to the shift shock. Or, in order to prevent deterioration of the life of the clutch, an increase in the size of the clutch is inevitable.

  In the hybrid vehicle shown in Patent Document 4, when the high-speed cruise operation is performed on the hybrid vehicle, the number of rotations of the electric motors 82 and 83 to be mounted becomes too large, and the lubrication equipment and the cooling device We must try to increase the size. In addition, problems such as a reduction in the life of the rotating parts of the electric motors 82 and 83, a reduction in system efficiency due to loss of the rotating parts, and a reduction in reliability of the electric motors 82 and 83 are caused.

  The present invention improves the energy efficiency of the entire system, makes it possible to control the acceleration / deceleration of the forward / rearward movement with a simple structure, enables the most efficient engine operation in terms of engine fuel consumption and exhaust gas, Proposed is a traveling work vehicle equipped with a power transmission structure that can efficiently distribute the motive power and the traveling power without shifting shock in real time.

The object of the present invention can be achieved by the inventions described in claims 1 and 2.
That is, in the traveling work vehicle of the present invention, the first generator motor connected to the output shaft of the engine, the hydraulic pump system and planetary gear mechanism connected to the output shaft of the first generator motor, and the output to the planetary gear mechanism. A second generator-motor having a shaft connected thereto, a power storage device connected to each of the first generator-motor and the second generator-motor via an inverter, and a wheel drive system connected to the output shaft of the planetary gear mechanism; With
The main feature is that the output shaft of the first generator motor and the output shaft of the second generator motor are respectively connected to different components in the planetary gear mechanism.

  Further, in the traveling work vehicle of the present invention, the first generator motor and the first motor according to the rotational speed of the engine, the traveling mode of the traveling work vehicle, and the rotational speed for driving the wheel in the wheel drive system. The main feature is that each of the two generator motors includes switching means for switching between a free rotation mode in which torque is not generated, a mode in which the two-generator motor is operated as a generator, and a mode in which the motor is operated as a motor.

  In the traveling work vehicle of the present invention, the driving force from the engine can be transmitted to the hydraulic pump system and the planetary gear mechanism via the first generator motor. In addition, the driving force from the second generator motor configured as a driving system different from the driving system from the engine can be transmitted to the same planetary gear mechanism. The wheel driving system is driven by the driving force output from the planetary gear mechanism.

  Further, the constituent part of the planetary gear mechanism connected to the output shaft of the first generator motor and the constituent part of the planetary gear mechanism connected to the output shaft of the second generator motor are configured as different constituent parts. Thereby, the drive rotation speed output from the planetary gear mechanism can be controlled to an arbitrary rotation speed by the rotation speed of the output shaft of the first generator motor and the rotation speed of the output shaft of the second generator motor.

  In other words, when the energy required to drive the hydraulic pump system or wheel drive system cannot be obtained only by driving the engine, the first generator motor and / or the second generator motor connected to the output shaft of the engine is appropriately used as the motor. By working, you can make up for the shortage of energy.

  When the energy required to drive the hydraulic pump system and wheel drive system is sufficient with only the power of the engine, the first generator motor should be in a free mode and act as a kind of flywheel. Can do. Also, when the engine power is surplus or when the power returns from the hydraulic pump system, the first generator motor is used as a generator to convert the surplus energy and regenerative energy into electrical energy, and the power storage device Can be charged.

Further, during the forward / backward advance and acceleration / deceleration operations of the traveling work vehicle, the regenerative energy generated by the power returned from the wheel drive system to the planetary gear mechanism is generated by the first generator motor and / or the second generator. It can be converted into electrical energy by an electric motor and the power storage device can be charged.
The electric energy charged in the power storage device in this way can be used as driving energy when the first generator motor and the second generator motor are operated as motors.

In the traveling work vehicle of the present invention, each of the first generator motor and the second generator motor according to the rotational speed of the engine, the traveling mode of the traveling work vehicle, and the rotational speed for driving the wheel in the wheel drive system. Switching means for switching the use mode can be provided.
By switching the switching means, the first generator motor and the second generator motor can be individually switched to a free rotation mode in which torque is not generated, a mode in which the motor is operated as a generator, and a mode in which the motor is operated as a motor.

  That is, the first power generation is performed so that the torque and the rotational speed applied to the wheel drive system are optimized according to the rotational speed of the engine, the traveling mode of the traveling work vehicle, and the rotational speed for driving the wheel in the wheel drive system. Each use mode in an electric motor and a 2nd generator motor can be switched. In addition, in each of the first generator motor and the second generator motor, the power returning from the wheel drive system to the first generator motor and the second generator motor can be absorbed by the first generator motor and / or the second generator motor. The usage mode can be switched.

  Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings. The configuration of the traveling work vehicle of the present invention will be described below by taking a wheel loader as an example. However, as the traveling work vehicle of the present invention, the present invention can be suitably applied to a traveling work vehicle such as a forklift, for example, other than the wheel loader configuration described below. For this reason, this invention is not limited to the Example demonstrated below, A various change is possible.

  FIG. 1 is an overall configuration diagram showing an internal structure of a traveling work vehicle 1 according to an embodiment of the present invention. As shown in FIG. 1, the driving force of the engine 2 is transmitted to the first generator motor 3 connected to the shaft A that is the output shaft of the engine 2, and the shaft B that is the output shaft of the first generator motor 3. It is configured to be transmitted to the hydraulic pump system 6 and the planetary gear mechanism 5 via the shaft C. Further, the driving force from the second generator motor 4 configured as a drive source different from the engine 2 is transmitted to the planetary gear mechanism 5 via the axis D which is the output shaft of the second generator motor 4. ing.

  When the power returned from the wheel drive system 10 or the power returned from the hydraulic pump system 6 acts on the shaft B, the shaft B does not become the output shaft of the first generator motor 3, but the first power generator The motor 3 functions as an input shaft that works as a generator. Similarly, when the engine 2 is not overloaded, or when the power returned from the wheel drive system 10 acts on the axis D, the axis D does not become the output shaft of the second generator motor 4. In addition, the second generator motor 4 functions as an input shaft that works as a generator.

At this time, the axis E, which is the output shaft of the planetary gear mechanism 5 described below, functions as an input shaft when the power returned from the wheel drive system 10 is input to the planetary gear mechanism 5. An axis E that is an output shaft of the planetary gear mechanism 5 is connected to the wheel drive system 10. The wheel drive system 10 includes a transmission 11 for switching the rotational speed connected to the axis E of the planetary gear mechanism 5 between Hi and Low, a power transmission mechanism 15 to which an output from the transmission 11 is transmitted, and a power transmission mechanism 15 And a pair of front wheels 18a and a pair of rear wheels 18b that are rotationally driven by rotation distributed by the front differential 16a and the rear differential 16b. It has become.
Further, for the front wheel 18a and the rear wheel 18b, a front wheel brake 17a and a rear wheel brake 17b for applying braking to the respective wheels are provided.

  The hydraulic pump system 6 includes a hydraulic pump gear train 7 that extracts the rotation of the shaft C, and a first hydraulic pump 6a and a second hydraulic pump 6b that are driven by the rotation extracted by the hydraulic pump gear train 7. Has been. The first hydraulic pump 6a is configured as a variable displacement hydraulic pump that supplies pressure oil to a working machine actuator, etc., and the second hydraulic pump 6b is a fixed displacement type for driving auxiliary equipment that discharges pilot pressure, etc. It is configured as a pump.

  The first generator motor 3 is connected to a battery 21 that is a power storage device via a first inverter 20a, and the second generator motor 4 is connected to the battery 21 that is a power storage device via a second inverter 20b. Yes. The first inverter 20a and the second inverter 20b are, according to the control signal from the controller 25, the first generator motor 3 and the second generator motor 4 in a free rotation mode, a mode in which the motor operates as a generator, and a mode in which the motor operates as a motor. Can be switched to.

  When the first generator motor 3 and the second generator motor 4 are operated as generators, the battery 21 can be charged with the electric energy generated by the first generator motor 3 and the second generator motor 4. . Further, when the first generator motor 3 and the second generator motor 4 are operated as electric motors, the first generator motor 3 and the second generator motor 4 can be operated as electric motors with the electric power charged in the battery 21.

  The controller 25 receives a detection signal from a speed sensor 30 that detects the number of revolutions on the axis E of the planetary gear mechanism 5, and also includes an operation amount of an accelerator pedal 26, an operation amount of a brake pedal 27, and a forward / reverse switching lever 28. A signal relating to the switching position at is input. The controller 25 controls the fuel amount to the engine 2 with respect to a fuel injection device (not shown) based on the values of these input signals and the like, and outputs control signals for the first inverter 20a and the second inverter 20b. .

  That is, when the controller 25 determines that the driving force of the engine 2 is insufficient, the first inverter 20a and / or the second inverter is used so that the first generator motor 3 and / or the second generator motor 4 are operated as an electric motor. Control 20b. In addition, when it is determined that there is power returned from the wheel drive system 10 or the hydraulic pump system 6, or when it is determined that the driving force of the engine 2 is excessive, or the engine 2 is excessively overloaded. When it is determined, the first inverter 20a and / or the second inverter 20b are controlled so that the first generator motor 3 and / or the second generator motor 4 function as a generator.

  Different constituent parts are selected for the constituent part of the planetary gear mechanism 5 to which the axis B of the first generator motor 3 is connected and the constituent part of the planetary gear mechanism 5 to which the axis D of the second generator motor 4 is connected. As a result, even if the rotation speed of the shaft E output from the planetary gear mechanism 5 is a mode in which the rotation speed of the engine 2 is kept constant, the rotation speed of the first generator motor 3 on the axis B and the second generator motor It can be controlled to an arbitrary number of revolutions according to the number of revolutions on the axis D of 4. Then, by controlling the rotational speed of the engine 2 with the controller 25, the rotational speed on the axis E can be controlled more finely.

  That is, the rotational fluctuation amount of the shaft B interlocked with the engine 2 is suppressed so as to be minimized, and the rotational speed of the second generator motor 4 operated as an electric motor is greatly varied, so that the traveling work vehicle is This makes it possible to perform the necessary forward / backward movement. In addition, since the first generator motor 3 is provided on the shaft B interlocked with the engine 2, the mode and motor in which the first generator motor 3 is used as a generator so that the amount of rotational fluctuation of the shaft B is minimized. It is possible to control the mode to be used or a free mode that does not generate torque.

  In addition, when the first generator motor 3 and the second generator motor 4 are operated by only the driving force of the engine as in the past by performing the IV quadrant operation of forward / reverse rotation, power running and regeneration, respectively. With the same operation as the operation, it is possible to perform forward / backward movement and acceleration / deceleration operations on the traveling work vehicle. The power necessary to perform each operation can be uniformly applied to the wheel drive system 10.

  Further, the power returned from the wheel drive system 10 can be absorbed by the first generator motor 3 and the second generator motor 4. Moreover, since the power returned from the wheel drive system 10 can be absorbed by the first generator motor 3 and the second generator motor 4, the engine 2 is overloaded by the power returned from the wheel drive system 10. It can be prevented from joining.

  Here, the IV quadrant operation described above will be explained. The IV quadrant here is a quadrant for indicating the relative relationship between the rotation direction and the sign of torque in the axis B of the first generator motor 3, the axis D of the second generator motor 4, and the axis E of the planetary gear mechanism 5. It is defined as That is, the case where both the rotational speed and torque are positive signs is the first quadrant, the case where the rotational speed is negative and the torque is positive signs is the second quadrant, and the case where both the rotational speed and torque are negative signs. The fourth quadrant is the third quadrant, where the number of revolutions is a plus sign and the torque is a minus sign. The quadrants I and III in which the second generator motor 4 is used as a motor are referred to as power running, and the II and IV quadrants in which the second generator motor 4 is used as a generator are referred to as regeneration. This is illustrated in FIG.

  The description of the IV quadrant operation will be described by taking as an example a case where a V-shape operation, which is a representative operation in the wheel loader used as the traveling work vehicle 1, is performed. V-shape operation is a series of operations that excavate piled sediment, load the sediment into the wheel loader bucket, reload the loaded sediment into a dump truck, and return to the original standby position after the replacement. This is the work (operation) for one cycle.

  When this series of cycle work is performed only with the driving force of the conventional engine, the time change between the rotational speed and the torque input / output to / from the wheel drive system 10 is a graph as shown in FIG. Also in the hybrid traveling work vehicle 1 according to the present invention, the drive source of the engine 2, the first generator motor 3, and the second generator motor 4 is controlled as described below, so that the wheel drive system 10 is input and output. The graph of the time change between the rotation speed and the torque can be drawn so as to be the same graph as the graph shown in FIG. Therefore, in the following description, the graph shown in FIG. 3 will be described as a graph obtained by the present invention.

  In FIG. 3, the thick line indicates the rotational speed input / output to / from the wheel drive system 10, and the dotted line indicates the torque input / output to / from the wheel drive system 10. The number of rotations and torque are given plus and minus signs.

  When the input shaft 11 of the traveling work vehicle 1 rotates in the forward direction, a plus sign is attached as the sign of the rotational speed, and the input shaft 11 of the traveling work vehicle 1 rotates in the reverse direction. In this case, a minus sign is attached as a sign of the rotational speed. In addition, when the signs of the rotational speed and torque are both positive and negative, the drive sources of the engine 2, the first generator motor 3 and the second generator motor 4 perform power running to indicate the state. When the signs of the torques are opposite to each other, a state is shown in which regeneration is performed by the power returned from the wheel drive system 10.

  By the way, in Example 1 shown in FIG. 1, since the structure in the planetary gear mechanism 5 is not described, it demonstrates below using Example 5 which has shown the structure in the planetary gear mechanism 5. FIG. To. In FIG. 7 showing the fifth embodiment, the same reference numerals are used for the same components as in FIG. 1, but some of the controller 25, speed sensor 30, accelerator pedal 26, etc. shown in FIG. The illustration of this configuration is omitted.

  In the traveling work vehicle 1 shown in FIG. 7, the shaft B of the first generator motor 3 is configured to directly drive the ring gear 35 d of the planetary gear mechanism 35. The axis D of the second generator motor 4 is connected to the sun gear 35a of the planetary gear mechanism 35, and the axis E of the planetary gear mechanism 35 is connected to the carrier 35c of the planetary gear mechanism 35. The planetary gear 35b that meshes with the ring gear 35d and the sun gear 35a is rotatably supported by the carrier 35c. The gear train 7 that drives the first hydraulic pump 6a and the second hydraulic pump 6b is configured to extract the rotation of the ring gear 35d.

3 will be described with reference to FIG.
The stop mode “1” in the table of FIG.

  In the stop mode in which the wheel loader is stopped in an empty state, the brake is depressed, and the rotation of the shaft E that is the output shaft of the planetary gear mechanism 35 is stopped. Therefore, the rotational speed from the engine 2 is transmitted to the axis D of the second generator motor 4 via the planetary gear mechanism 35. Then, the second generator motor 4 idles in the minus direction and absorbs the rotational speed from the engine. At this time, the second generator motor 4 is in a free mode in which torque is not generated and is not a load on the engine 2.

  When the description of the table shown in FIG. 3 is added, the operation modes of “1” to “10” are arranged as items on the horizontal axis, and the second generator motor 4 and the first generator motor 3 are arranged as columns. The engine 2, shaft B, shaft C, accelerator pedal 26, brake pedal 27, and forward / reverse switching lever 28 are arranged in this order. And the place where the item on the vertical axis overlaps with the item on the horizontal axis shows the mode state of the member indicated by the item on the vertical axis in the operation mode set as the item on the horizontal axis.

  For example, in the stop mode “1”, the second generator motor 4 is in the second quadrant operation and is in a free mode in which torque is not generated. The first generator motor 3 and the engine 2 and the shaft B are all in the quadrant I operation. The axis C is in a “−” state that is not related to the traveling of the wheel loader. The accelerator pedal 26 is in an “OFF” state in which the accelerator pedal 26 is not operated, the brake pedal 27 is in an “ON” state in which the accelerator pedal 26 is operating, and the forward / reverse switching lever 28 is in the neutral position “N” position. Indicates that it is placed.

  The Roman numerals “I”, “II”, “III”, and “IV” represent the quadrants shown in FIG. 2, and “N”, “F”, “ “B” indicates that the switching positions of the forward / reverse switching lever 28 are a neutral position, a forward position, and a reverse position, respectively.

  The forward start mode of “2” in the table of FIG.

  In this forward start mode, the forward / reverse switching lever 28 (see FIG. 1) enters the forward position “N”, the brake pedal 27 (see FIG. 1) changes from “ON” to “OFF”, and the accelerator pedal 26 (see FIG. 1). ) Will be stepped from “OFF” to “ON”. The first generator motor 3, the second generator motor 4, or the shaft A of the engine 2 generates torque so that torque proportional to the amount of depression of the accelerator pedal 26 is generated on the axis E of the planetary gear mechanism 35. At this time, the torque is distributed to the second generator motor 4 and the first generator motor 3 or the shaft A of the engine 2 according to the planetary gear coupling method in the planetary gear mechanism 35 and the gear ratio at that time.

That is, if energy loss is not considered in the case of FIG. 7, the torque τ is distributed as follows.
τr = τp / (1 + α) = τs / α
Here, α is the gear ratio of the planetary gear, τr is the torque in the ring gear 35d, τp is the torque in the carrier 35c, and τs is the torque in the sun gear 35a.

  When the accelerator pedal 26 is depressed, a throttle (not shown) for supplying fuel to the engine 2 opens, and the engine 2 tries to increase the rotational speed together with the torque output. At this time, the shaft E is rotated by the rotation of the engine 2. However, since the wheel loader is stopped, the axis E of the planetary gear mechanism 35 is stopped. Therefore, the reaction force torque that is to be returned to the engine 2 from the stopped shaft E flows toward the shaft D of the second generator motor 4.

At this time, the first generator motor 3 is controlled so as to rotate the axis E of the planetary gear mechanism 35 in the forward direction of the wheel loader while keeping the rotational speed output from the engine 2 constant. In the configuration of the planetary gear mechanism 35 shown in FIG. 7, the rotational speed of the second generator motor 4 that drives the sun gear 35a, the rotational speed of the engine 2 or the first generator motor 3 that drives the ring gear 35d, and the carrier 35c. The relationship of the rotational speed of the axis E of the planetary gear mechanism 35 can be expressed by the following equation.
ωr = (1 + α) ωp − αωs
Here, α is a gear ratio of the planetary gear, ωr is an angular velocity in the ring gear 35d, ωp is an angular velocity in the carrier 35c, and ωs is an angular velocity in the sun gear 35a.

  The rotation speed of the second generator motor 4 is controlled by the controller 25 that monitors the rotation speed of the engine 2 so that the rotation speed of the axis E of the planetary gear mechanism 35 becomes a predetermined rotation speed. Whether or not the rotational speed of the axis E of the planetary gear mechanism 35 has reached a predetermined rotational speed can be detected by the speed sensor 30 (see FIG. 1).

In the starting stage, the second generator motor 4 that has been idly reversed in the minus direction is controlled at a predetermined number of revolutions while generating electricity by rotating in the minus direction so as to satisfy the relational expression of the torque and the number of revolutions described above. (Second quadrant operation). As a result, a large torque required to advance the wheel loader can be output from the axis E of the planetary gear mechanism 35 with the engine speed kept constant.
In this mode, the second generator motor 4 will act as a generator, and the generated energy will be charged to the battery 21 or consumed by the first generator motor 3 acting as a motor. Become.

  The forward mode “3” in the table of FIG.

  When the wheel loader starts moving forward in the forward mode, the second generator motor 4 gradually decreases the rotational speed and finally reaches zero speed. Since the axis E of the planetary gear mechanism 35 rotates based on the relative rotational speed between the axes B and D, when the shaft E reaches a certain rotational speed, the second generator motor 4 reaches zero speed, Further, the sign of the rotational speed is reversed from the rotation in the minus direction to the rotation in the plus direction, and the vehicle is continuously accelerated.

  At this time, since the accelerator pedal 26 (see FIG. 1) remains in the depressed “ON” mode, the rotation speed of the second generator motor 4 is successively increased to the axis of the planetary gear mechanism 35 in order to continue acceleration. In accordance with the rotational speed at E and the engine rotational speed, control is performed to achieve a desired rotational speed.

  When the sign of the rotation speed of the second generator motor 4 is reversed from minus to plus, the second generator motor 4 shifts from the power generation mode to the power running mode (first quadrant). That is, when the sign of the rotation speed of the second generator motor 4 is reversed to plus, the second generator motor 4 functions as an electric motor.

  As a result, the second generator motor 4 has so far supplied power generation energy for supplying power to the first generator motor 3, but energy is required for the second generator motor 4 to function as a motor. Since the engine 2 is also operating in the first quadrant at the same time as the second generator motor 4, the first generator motor 3 becomes a generator (fourth quadrant) and supplies energy to the second generator motor 4. become. In this way, the same graph as the graph at the time of forward movement in FIG. 3 can be drawn as the rotation speed and torque on the axis E of the planetary gear mechanism 35.

  The forward and excavation modes of “4” and “5” in the table of FIG.

  In this forward / excavation mode, the soil moves forward while excavating soil. In this mode, as an output from the axis E of the planetary gear mechanism 35, the wheel loader is required to travel at a low speed and to obtain a large torque. In this mode, the wheel loader receives a reaction force from the earth and sand, so the vehicle speed tends to become unstable.

  As a result, the wheel loader repeats start, stop, and advance in small steps, and the forward start mode and the forward mode described above are sequentially switched according to the travel mode of the wheel loader. At this time, it is the second generator motor 4 that needs to switch the operation most frequently.

  However, when the second generator motor 4 whose operation is most frequently switched is examined and examined, the rotational speed of the shaft A of the engine 2 or the shaft B of the first generator motor 3 and the rotational speed of the shaft E of the planetary gear mechanism 35 are Is constantly monitored so that the optimum torque and rotational speed can be drawn from the second generator motor 4 from the accelerator opening by the accelerator pedal 26 (see FIG. 1) and the vehicle speed of the wheel loader. It can be seen that the rotation of 4 is only controlled.

  Also at this time, by controlling the first generator motor 3 and the second generator motor 4, the same graph as the graph at the time of forward excavation in FIG. 3 can be drawn as the rotation speed and torque on the axis E of the planetary gear mechanism 35. Can do.

  “6” reverse (sediment transport) mode in the table of FIG.

  In this reverse (sediment transport) mode, when the forward / reverse switching lever 28 (see FIG. 1) is switched to the reverse position, the first power generation is performed so as to reverse the direction of the rotational speed on the axis E of the planetary gear mechanism 35. The motor 3 and the second generator motor 4 work together to change the control scheme.

  That is, the first generator motor 3 and the second generator motor 4 are controlled so that the axis E of the planetary gear mechanism 35 rotates in the reverse direction by the accelerator opening by the accelerator pedal 26 (see FIG. 1). The second generator motor 4 is in the third quadrant operation mode in which the signs of the rotation speed and torque are reversed, and the first generator motor 3 is coaxial with the engine 2, so the rotation speed is constant, but the sign of torque is reversed. The fourth quadrant operation mode is set.

  The second generator motor 4 is subjected to rotational speed control for setting the shaft E to a predetermined rotational speed, based on the rotational speed of the engine 2 and the rotational speed of the planetary gear mechanism 35 on the shaft E, as in the forward movement. The first generator motor 3 is subjected to torque control for absorbing torque distributed from the shaft E by the accelerator opening degree by the accelerator pedal 26 (see FIG. 1). At this time, the reference rotational speed is determined by the rotational speed of the engine 2.

  Also at this time, by controlling the first generator motor 3 and the second generator motor 4, the same graph as the graph at the time of reverse travel (sediment transport) of FIG. Can be drawn.

  The “7” forward start mode, “8” forward mode, “9” forward / load mode, and “10” reverse mode in the table of FIG. The same control as in the mode is repeated.

  As described above, in the present invention, the engine 2, the first generator motor 3, and the second generator motor 4 are controlled corresponding to each work mode in the wheel loader while taking advantage of the hybrid of the traveling work vehicle. Thus, the same rotation speed and torque as those performed by the engine alone can be applied to the axis E of the planetary gear mechanism 35. That is, it is possible to operate a traveling work vehicle such as a hybrid wheel loader by the same operation as that performed by the engine alone.

  Returning to FIG. 1 and continuing the description, as the wheel loader, the traveling speed required for excavation / loading work is only required for the speed range from the low speed range to the medium speed range. However, on the other hand, it is necessary to be able to run at high speed when moving in the workplace.

  By switching the transmission 11 shown in FIG. 1, when the vehicle is traveling at high speed, the transmission 11 can be switched to the Hi mode, so that the number of revolutions necessary for traveling at high speed can be given to the wheel. For this reason, it is not necessary to enlarge the second generator motor 4 and to configure the rotational speed of the second generator motor 4 to be extremely high.

Further, during normal work, as described above, the speed is limited to the speed range from the low speed range to the medium speed range. Therefore, it is only necessary to switch the transmission 11 to the Low mode, and there is no concern about a shift shock or the like. Furthermore, when high-speed traveling is required, since the vehicle will start in an empty state in which earth and sand etc. are not loaded in the work machine such as a bucket, when switching the transmission 11 from the Low mode to the Hi mode, The shift shock at the timing of switching from medium speed to high speed is not a big problem.
The configuration of the transmission 11 will be described after the description of each embodiment described below.

  Since the present invention is configured as described above, the hybrid traveling work vehicle can be operated in the same operation as that performed by a conventional engine alone in the entire range from low speed to high speed.

  Further, it is possible to rotate the shaft B that is the input shaft of the planetary gear mechanism 5 that rotates in conjunction with the shaft A of the engine 2 so that the fluctuation of the rotational speed is minimized. Alternatively, the rotational speed of the engine 2 can be controlled so that the engine rotational speed is most suitable for fuel consumption and exhaust gas reduction corresponding to the load required for the engine 2.

The functions of the devices in the shaft E of the engine 2, the first generator motor 3, the planetary gear mechanism 5, the second generator motor 4, and the planetary gear mechanism 5 in the present invention can be summarized as follows.
That is, the engine 2 is required to output an optimum rotational speed in accordance with the required load, and further, is required to have an engine rotational speed most suitable for fuel consumption and exhaust gas reduction. That is, the engine 2 outputs the rotational speed of the shaft E required to obtain the driving power for running the wheel loader and the rotational speed required of the shaft E, and the optimum rotational speed required of the engine 2 is output. It is required to meet.

The second generator motor 4 adjusts the rotational speed from the engine 2 via the planetary gear mechanism 5 so that the rotational speed required for the shaft E can be output.
As the first generator motor 3, when the output required from the engine 2 and the optimal engine speed cannot be adjusted from the output from the engine 2 and the output from the second generator motor 4, The first generator motor 3 works as a motor to assist the shortage. As a result, the load on the engine 2 can be reduced. Further, in order to rotate the engine 2 at the optimum rotational speed, it may function as a load on the engine 2 or may function as a generator that supplies electric power to the battery 21.

Then, by generating electricity by using the first generator motor 3 as a generator, it is possible to brake the rotation of the engine 2 and to increase the load applied to the engine 2.
However, the amount of power stored when the first generator-motor 3 is operated as a generator is also limited by the amount of power stored in the battery 21 that is the power source of the second generator-motor 4.

As the planetary gear mechanism 5, the rotation speed and torque input from the shaft B from the engine 2 and the first generator motor 3 and the shaft D of the second generator motor 4 are adjusted in the planetary gear mechanism 5. It can be output to the axis E of the planetary gear mechanism 5.
The axis E can output rotation in accordance with the traveling speed of the wheel loader.

  Next, the operation of the hydraulic pump system 6 that drives the work implement actuator during excavation work at low speeds will be described. At this time, the number of revolutions of the engine 2 is set to be lower in accordance with a request for traveling power supplied to the wheel loader. On the other hand, since the first hydraulic pump 6a that drives the work implement actuator requires a large amount of power, the discharge flow rate from the first hydraulic pump 6a is increased.

  For this reason, the pump discharge capacity per rotation of the first hydraulic pump 6a can be increased by configuring the first hydraulic pump 6a as a variable displacement hydraulic pump. And even if the rotational speed of the engine 2 is kept low, the operating speed and power of the work implement actuator do not decrease. That is, the range in which the power in the work implement actuator can be adjusted is expanded regardless of the rotational speed of the engine 2.

  It is necessary to ensure both the traveling power of the wheel loader and the power of the work implement actuator during excavation work at this low speed. For this reason, it is necessary to increase the amount of power stored in the battery 25 in advance, and when the work implement actuator needs power instantaneously, the shaft C that supplies power for the hydraulic pump system 6 is motored. Thus, it is possible to control the electric power supplied from the battery 25 to the first generator motor 3 that is working as an electric motor.

  That is, the power from the engine 2 can be distributed to the wheel drive system 10, and the power to the hydraulic pump system 6 can be driven by the first generator motor 3 that is operating as an electric motor.

  Therefore, in the present invention, it is possible to perform a greater work than the engine 2 is outputting. As a result, it is possible to configure the engine 2 with a smaller capacity, and it is possible to output more power than the power of the engine mounted on the conventional traveling work vehicle.

  However, the work machine actuator requires a large amount of power for a time of only a few seconds for scooping earth and sand, and is an intermittent operation. On the other hand, the electric power required to be generated by the first generator motor 3 or the second generator motor 4 that has worked as a generator is always required to be used as power for running the wheel loader. It is what. For this reason, even if the working machine actuator as described above requests the necessary power instantaneously, the energy consumed by the first generator motor 3 at this time is the amount of power generated by the second generator motor 4 Will be better.

  Similarly to the rotation of the engine 2, the second hydraulic pump 6b for driving the auxiliary machinery and the first hydraulic pump 6a for the working machine need to be driven only in a certain rotational direction and always rotate. For this reason, the axis C that is the input shaft of the hydraulic pump system 6 is a member that has the smallest fluctuation in the number of rotations among the members that are the input and output shafts in the planetary gear mechanism 5, and is linked to the axis A of the engine 2. The most preferable configuration is to extract the rotation from the member coupled to the shaft B. That is, it is desirable to arrange the hydraulic pump system 6 on the rotating shaft close to the engine 2 in the entire vehicle.

  FIG. 4 is a second embodiment according to the present invention, and specifically shows the configuration of the gear train 7 in the hydraulic pump system 6 and the internal configuration in the planetary gear mechanism 32. Other configurations are the same as those in the first embodiment. Therefore, regarding the same members, the same reference numerals as those used in Example 1 are used, and the description thereof is omitted. Further, regarding the configuration of a part of the controller 25, the speed sensor 30, the accelerator pedal 26, etc. shown in FIG. 1, those members are not shown in FIG.

  As shown in FIG. 4, the shaft B of the first generator motor 3 also serves as the drive shaft of the first hydraulic pump 6 a, and the gear 37 provided on the shaft B serves as a part of the gear train 7 in the hydraulic pump system 6. It is composed. A gear 37 provided on the shaft B of the first generator motor 3 meshes with external teeth formed on the outer periphery of the ring gear 32d in the planetary gear mechanism 32 via a gear 38.

  The planetary gear 32b supported by the carrier 32c meshes with the internal teeth of the ring gear 32d in the planetary gear mechanism 32, and the rotation of the carrier 32c is extracted by the shaft E. The axis E is configured as an input shaft to the wheel drive system 10. The sun gear 32a with which the planetary gear 32b meshes is provided on the axis D of the second generator motor 4.

  That is, the rotation from the engine 2 and the first generator motor 3 is input to the ring gear 32d in the planetary gear mechanism 32, and the rotation from the second generator motor 4 is input to the sun gear 32a. The rotation taken out by the carrier 32c is an output from the planetary gear mechanism 32.

  In the second embodiment, since the first hydraulic pump 6a for the work machine actuator is directly connected to the engine 2 and the first generator motor 3, even when a large work machine power is instantaneously required, One generator motor 3 can direct a large amount of power to the work machine actuator without delay in response. And it becomes possible to perform the agile operation | movement of a working machine actuator.

  FIG. 5 shows a third embodiment according to the present invention, in which the power to the second hydraulic pump 6b in the hydraulic pump system 6 is arranged to be taken out from the planetary gear mechanism 33, and the second generator motor 4 is connected to the planetary gear. The arrangement is arranged between the gear mechanism 33 and the wheel drive system 10. Other configurations are the same as those in the first embodiment. Therefore, regarding the same members, the same reference numerals as those used in Example 1 are used, and the description thereof is omitted. Further, regarding the configuration of a part of the controller 25, the speed sensor 30, the accelerator pedal 26, and the like shown in FIG. 1, those members are not shown in FIG.

  As shown in FIG. 5, the shaft B of the first generator motor 3 is configured to also serve as the drive shaft of the first hydraulic pump 6 a, and the gear 37 provided on the shaft B of the first generator motor 3 is a gear 38. Is engaged with external teeth formed on the outer periphery of the ring gear 32d in the planetary gear mechanism 32. Further, the second hydraulic pump 6b is driven by the rotation of the ring gear 32d.

  The planetary gear 32b supported by the carrier 32c meshes with the internal teeth of the ring gear 32d in the planetary gear mechanism 32, and the rotation of the carrier 32c is extracted by the shaft E. The axis E is configured as an input shaft to the wheel drive system 10. The sun gear 32a meshed with the planetary gear 32b is provided on the axis D of the second generator motor 4, and the axis E passes through the axis D.

  In the third embodiment, the second hydraulic pump 6b for auxiliary machinery or the first hydraulic pump 6a for working machinery can be disposed on one end side of the planetary gear mechanism 32. It becomes unnecessary, and it becomes possible to increase the driving efficiency and downsize the configuration of the power transmission unit.

  FIG. 6 shows a fourth embodiment according to the present invention in which the ring gear 34d of the planetary gear mechanism 34 is directly driven by the shaft B rotating in conjunction with the shaft A of the engine 2. The first hydraulic pump 6a and the second hydraulic pump 8b are driven via the gear train 7, and the axis D of the second generator motor 4 is arranged via the gear train 8 provided on the sun gear 34a. Further, the rotation of the carrier 34c is extracted as the rotation about the axis E.

  In FIG. 6, the same members as those in the first embodiment are denoted by the same reference numerals as those used in the first embodiment, and the description thereof is omitted. Further, regarding the configuration of a part of the controller 25, the speed sensor 30, the accelerator pedal 26, and the like shown in FIG. 1, those members are not shown in FIG.

  According to the fourth embodiment, since the power of the engine 2 can be efficiently distributed as power for traveling, acceleration / deceleration during traveling of the wheel loader can be performed quickly, and regeneration during braking is performed. The amount of energy absorbed can be increased.

  FIG. 7 shows the configuration of the fifth embodiment according to the present invention. Since the configuration of the embodiment 5 has already been described when the above-described IV quadrant is described, the description of the configuration is as follows. Omitted.

  As shown in FIG. 7, in the fifth embodiment, the ring gear 35d of the planetary gear mechanism 35 is directly driven by the shaft B that rotates in conjunction with the shaft A of the engine 2. The first hydraulic pump 6a and the second hydraulic pump 8b are driven via the gear train 7, and the shaft D of the second generator motor 4 is directly connected to the sun gear 34a. Further, the rotation of the carrier 34c is extracted as the rotation about the axis E.

  According to the configuration of the fifth embodiment, the speed change mechanism portion including the planetary gear mechanism 35 in the first to fourth embodiments can be minimized. Therefore, the configuration of the fifth embodiment can be provided in a state where the number of changed portions is minimized from the layout configuration in the conventional traveling work vehicle.

  In the conventional wheel loader, an operation cab is arranged at the upper center of the vehicle body, an axle is arranged along the front-rear direction at the lower part of the vehicle body, and the propeller shaft is penetrated at the center. Since it is comprised in this way, the engine is arrange | positioned in the upper part rather than the axle part in the vehicle rear part.

  In order to obtain the excavation reaction force of the wheel loader, by placing a heavy object such as an engine at the rear part of the vehicle body, it is possible to obtain an effect that the counterweight disposed at the rearmost part of the vehicle body can be made small. In the present invention, since the speed change mechanism portion can be reduced in size, the front portion where the engine is installed can be utilized as an installation space for the speed change mechanism portion.

  In a conventional traveling work vehicle, devices such as a torque converter, a PTO (power distribution machine), and a multi-stage transmission have been placed in the front space where the engine is installed. Therefore, in the hybrid vehicle according to the present invention, in order to utilize this space region, the first generator motor 3 and the planetary gear are arranged on the front side of the engine output shaft so as to be coaxial with the engine output shaft as in the fifth embodiment. Arrangement of devices such as the gear mechanism 35, the second generator motor 4, and the transmission 11 is the most desirable configuration.

Configuration example of transmission 11

  A configuration example of the transmission 11 shown in FIGS. 8 to 14 will be described. Although the configuration is shown in FIGS. 8 to 14 as configuration examples of the transmission 11, the configuration of the transmission 11 is not limited to these configuration examples, and various modifications can be made. Further, although an example of a two-speed shift is shown as the configuration of the transmission 11, a multi-speed shift configuration may be used.

In the transmission 11 shown in FIG. 8, Hi-Low switching is configured by two sets of large and small gears, the first clutch CL1, and the second clutch CL2. In this configuration, in the Hi mode, the first clutch CL1 is engaged and the second clutch CL2 is disengaged, so that the rotation entered from in can be converted into high-speed rotation and output from out. Further, in the low mode, the first clutch CL1 is disconnected and the second clutch CL2 is engaged, so that the rotation entered from in can be converted into a low-speed rotation and output from out.
In the configuration of the transmission 11, the structure is the simplest and simplest.

  In the transmission 11 shown in FIG. 9, Hi-Low switching is performed with two sets of large and small gears, a set of planetary gear mechanisms 14, a first clutch CL 1, a second clutch CL 2, a first brake BL 1 and a second brake BL 2 It is composed by. In this configuration, in Hi mode, the first clutch CL1 is disengaged, the second clutch CL2 is engaged, the first brake BL1 is engaged, and the second brake BL2 is disengaged, so that the rotation entered from in is rotated at high speed. Can be output from out.

In Low mode, the first clutch CL1 is engaged, the second clutch CL2 is disconnected, the first brake BL1 is disconnected, and the second brake BL2 is engaged. And can be output from out.
In the configuration of the transmission 11, since there are few useless followers in one shift operation in mode switching, an efficient shift is possible.

  In the transmission 11 shown in FIG. 10, the switching between Hi and Low is made up of a set of large and small gears, a set of planetary gear mechanisms 14, a first brake BL1, a second brake BL2, and a large gear 40 slide mechanism. ing. In Hi mode, the first brake BL1 is engaged, the second brake BL2 is disconnected, and the large gear 40 is slid in the direction away from the planetary gear mechanism 14 (indicated by the dotted line in the figure), so that the rotation entered from in is accelerated It can be converted to rotation and output from out.

  In the low mode, the first brake BL1 is disconnected, the second brake BL2 is engaged, and the large gear 40 is slid in a direction (solid line state in the figure) close to the planetary gear mechanism 14, thereby rotating from the in. It can be converted to low-speed rotation and output from out.

In addition, when the large gear 40 is slid at the time of Hi-Low switching, a gear speed detection (not shown) is performed so that the large gear 40 and the small gear can be smoothly meshed, that is, in order to synchronize the meshing position. By adjusting the input side speed by means, the slide of the large gear 40 can be shifted more smoothly.
In the configuration of the transmission 11, there is less useless part in one shift operation in mode switching, and an efficient shift is possible.

  In the transmission 11 shown in FIG. 11, Hi-Low switching is performed with two sets of large and small gears, a set of planetary gear mechanisms 14, a first clutch CL1, a second clutch CL2, a first brake BL1, and a second brake BL2. It consists of and. In Hi mode, the first clutch CL1CL1 is disengaged, the second clutch CL2 is engaged, the first brake BL1 is engaged, and the second brake BL2 is disengaged to convert the rotation entered from in to high speed rotation. And can be output from out.

In Low mode, the first clutch CL1 is engaged, the second clutch CL2 is disconnected, the first brake BL1 is disconnected, and the second brake BL2 is engaged. And can be output from out.
In the configuration of the transmission 11, there is little useless part in one shift operation in mode switching, and an efficient shift is possible.

  In the transmission 11 shown in FIG. 12, Hi-Low switching is constituted by a set of planetary gear mechanism 14, a planetary gear, a first clutch CL1, a second clutch CL2, and a first brake BL1 and a second brake BL2. Has been. In the Hi mode, the second clutch CL2 is disengaged, the first clutch CL1 is engaged, the first brake BL1 is engaged, and the second brake BL2 is disengaged to convert the rotation entered from in to high speed rotation. Can be output from out.

In the low mode, the second clutch CL2 is engaged, the first clutch CL1 is disengaged, the first brake BL1 is disengaged, and the second brake BL2 is engaged. It can be converted and output from out.
In the configuration of the transmission 11, there is little useless part in one shift operation in mode switching, and an efficient shift is possible.

  The transmission 11 shown in FIG. 13 includes two sets of planetary gear mechanisms 14a and 14b and a first brake BL1 and a second brake BL2 for Hi-Low switching. In the Hi mode, by engaging the first brake BL1 and disconnecting the second brake BL2, the rotation entered from in can be converted into high-speed rotation and output from out.

In the Low mode, the first brake BL1 is disconnected and the second brake BL2 is engaged, so that the rotation entered from in can be converted into a low-speed rotation and output from out.
In the configuration of the transmission 11, since the input and output of in and out are arranged coaxially, the transmission 11 can be downsized. Furthermore, a simple configuration of a holding brake device disposed on the outer peripheral portion of the planetary gear mechanisms 14a and 14b can be achieved.

  In the transmission 11 shown in FIG. 14, the Hi-Low switching is constituted by two sets of planetary gear mechanisms 14a, 14b, a first brake BL1, and a second brake BL2. In the Hi mode, the first brake BL1 is engaged and the second brake BL2 is disconnected, so that the rotation entered from in can be converted into high-speed rotation and output from out.

In the Low mode, the first brake BL1 is disconnected and the second brake BL2 is engaged, so that the rotation entered from in can be converted into a low-speed rotation and output from out.
In the configuration of the transmission 11, since the input and output of in and out are coaxially arranged, the transmission 11 can be reduced in size. Furthermore, a simple configuration of a holding brake device disposed on the outer peripheral portion of the planetary gear mechanisms 14a and 14b can be achieved.

  The technical idea of the present invention can be applied to a device or the like to which the technical idea of the present invention can be applied.

1 is an overall configuration diagram of a traveling work vehicle according to an embodiment of the present invention. Example 1 It is explanatory drawing of IV quadrant. (Explanation) It is the figure which showed the state of each structural member corresponding to the operation | movement pattern of a traveling work vehicle. (Example) It is another whole block diagram of a traveling work vehicle. (Example 2) It is another whole block diagram of a traveling work vehicle. (Example 3) It is another whole block diagram of a traveling work vehicle. (Example 4) FIG. 10 is still another overall configuration diagram of the traveling work vehicle. (Example 5) It is a block diagram of a transmission. (Example) It is another block diagram of a transmission. (Example) It is another block diagram of a transmission. (Example) It is another block diagram of a transmission. (Example) FIG. 6 is still another configuration diagram of the transmission. (Example) It is another block diagram of a transmission. (Example) It is still another configuration diagram of the transmission. (Example) 1 is an overall configuration diagram of a traveling work vehicle. (Conventional example 1) 1 is an overall configuration diagram of a traveling work vehicle. (Conventional example 2) 1 is an overall configuration diagram of a traveling work vehicle. (Conventional example 3) 1 is an overall configuration diagram of a traveling work vehicle. (Conventional example 4)

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Travel work vehicle, 3 ... 1st generator motor, 4 ... 2nd generator motor, 5 ... Planetary gear mechanism, 6 ... Hydraulic pump system, 10 ... Wheel drive system, DESCRIPTION OF SYMBOLS 11 ... Transmission, 20a ... 1st inverter, 20b ... 2nd inverter, 21 ... Battery, 25 ... Controller, 32-35 ... Planetary gear mechanism, 50 ... Engine 51 ... hydraulic pump, 52 ... generator, 53 ... motor, 54 ... battery, 60 ... engine, 61, 62 ... generator motor, 63 ... generator, 64 ... Battery, 70 ... Engine, 72, 73 ... Electric generator motor, 74-76 ... Planetary reducer, 80 ... Engine, 82, 83 ... Electric motor, 84 ... Planetary reducer.

Claims (2)

A first generator motor connected to the output shaft of the engine;
A hydraulic pump system and a planetary gear mechanism connected to the output shaft of the first generator motor;
A second generator motor having an output shaft connected to the planetary gear mechanism;
A power storage device connected to each of the first generator motor and the second generator motor via an inverter, and
A wheel drive system connected to the output shaft of the planetary gear mechanism;
With
A traveling work vehicle, wherein an output shaft of the first generator motor and an output shaft of the second generator motor are respectively connected to different components of the planetary gear mechanism.   Torque is not generated in each of the first generator motor and the second generator motor according to the engine speed, the travel mode of the traveling work vehicle, and the speed at which the wheel is driven in the wheel drive system. 2. The traveling work vehicle according to claim 1, further comprising switching means for switching between a free rotation mode, a mode for operating as a generator, and a mode for operating as an electric motor.

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