JP2010163946A - Motor controlling device for working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor controlling device for a working vehicle that improves fuel consumption. <P>SOLUTION: A motor controlling device includes a hydraulic pump 11 driven by an engine 1, a hydraulic actuator 12 for travel driven by pressure oil from the hydraulic pump 11, a mode selection means 31 for selecting a parking mode at which a handbrake operates, a work mode in which a work brake operates, and a travel mode in which both the handbrake and the work brake are not operating, rotation speed setting means 22a, 33 for setting an engine target speed in the travel mode and engine target speed in the working mode, respectively, and a rotation speed control means 30 for controlling the engine speed to the target engine speed set by the rotation speed setting means 22a, 33, when the travel mode or the work mode is selected by the mode selection means 31, and controlling the engine speed to a parking idle rotation speed NL3 at least lower than a travel-idle rotation speed NL2 which is an idle rotation speed at the time of the travel mode, when the parking mode is selected, regardless of the setting by the rotation speed setting means 22a, 33. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a prime mover control device for a work vehicle such as a wheeled hydraulic excavator.

  2. Description of the Related Art Conventionally, there has been known an apparatus that reduces an idle speed when an occupant leaves a cab in a traveling mode (see, for example, Patent Document 1). In the device described in Patent Document 1, when the gate lock lever is operated to the lock position while the vehicle is stopped, the idle speed is reduced and the parking brake is operated.

Japanese Patent Laying-Open No. 2007-71135 (FIG. 8)

  However, since the device described in Patent Document 1 reduces the idling speed on the condition that the occupant gets off, the idling speed remains high until the occupant gets off even in the traveling stop state, thereby improving fuel consumption. Is desired.

  A prime mover control device for a work vehicle according to the present invention includes a hydraulic pump driven by an engine, a traveling hydraulic actuator driven by pressure oil from the hydraulic pump, a parking mode in which a parking brake is activated, and a working mode in which a work brake is activated. A mode selection means for selecting a travel mode in which both the parking brake and the work brake are inoperative, a speed setting means for setting an engine target speed in the travel mode and an engine target speed in the work mode, and a mode. When the driving mode or the work mode is selected by the selection means, the engine speed is controlled so as to be the target engine speed set by the speed setting means, and when the parking mode is selected, the speed setting means Regardless of the setting, at least the running idle speed that is the idling speed in the running mode. Characterized in that it comprises a rotational speed control means for controlling the engine speed so that the lower car idle speed than the number.

  According to the present invention, when the parking mode is selected by the mode selection means, the engine speed is controlled to a parking idle speed lower than the running idle speed, so that the engine speed in the parking mode is reduced. Can improve fuel efficiency.

The side view of the wheel type wheel excavator to which the present invention is applied. FIG. 2 is a drive hydraulic circuit diagram of a working actuator mounted on the wheel excavator of FIG. 1. The hydraulic circuit diagram for driving | running | working of the working vehicle which concerns on this Embodiment. The block diagram which shows the structure of the motor | power_engine control apparatus which concerns on this Embodiment. The figure which shows the target rotational speed characteristic by this Embodiment. The flowchart which shows an example of the process in the controller of FIG. The figure which shows the modification of FIG.

Hereinafter, an embodiment of a prime mover control device for a work vehicle according to the present invention will be described with reference to FIGS.
FIG. 1 is a side view (partially sectional view) of a wheeled hydraulic excavator (wheel excavator) to which the present invention is applied. The wheel excavator shown in FIG. 1 has a lower traveling body 81 and an upper revolving body 83 that is connected to an upper portion of the lower traveling body 81 via a turning device 82 so as to be able to turn. The upper swing body 83 is provided with a work front 84 and a cab 85 including a boom 84A, an arm 84B, and a bucket 84C. The gate of the cab 85 is provided with a gate lock lever 6 that can be operated between a release position (A position) protruding from the boarding / alighting path and a lock position (B position) retracted from the boarding / alighting path. The lower traveling body 81 is provided with a traveling hydraulic motor 12, and the tire 86 is rotated by driving the hydraulic motor 12.

  FIG. 2 is a drive hydraulic circuit diagram of the working actuator mounted on the wheel excavator. Pressure oil from a hydraulic pump 2 driven by the engine 1 is supplied to a working actuator 5 via a lock valve 3 and a control valve 4. The work actuator 5 is, for example, a hydraulic cylinder that drives the work front 84, a hydraulic motor that turns the swing body 83, or the like.

  The lock valve 3 is a two-position switching valve that can be switched between a communication position that guides the pressure oil from the hydraulic pump 2 to the control valve 4 and a shut-off position that blocks the supply of the pressure oil to the control valve 4. It can be switched by the operation of. That is, when the gate lock lever 6 is operated to the release position, the lock valve 3 is switched to the communication position, and when the gate lock lever 6 is operated to the lock position, the lock valve 3 is switched to the blocking position.

  The control valve 4 is switched by the operation of the operation lever 7 and controls the flow of pressure oil from the lock valve 3 to the hydraulic actuator 5. The configuration of the hydraulic circuit is not limited to that shown in FIG. For example, the control valve 4 is configured as a hydraulic pilot type switching valve, a pilot circuit that generates a pilot pressure according to the operation amount of the operation lever 7 is provided, and the control valve 4 is switched by the pilot pressure according to the operation amount of the operation lever 7. You may do it. In this case, the lock valve 3 may be disposed in the pilot circuit, and the operation of the operation lever 7 may be prohibited.

  FIG. 3 is a traveling hydraulic circuit diagram of the wheel excavator according to the present embodiment. This hydraulic circuit includes a hydraulic pump 11 driven by the engine 1, a hydraulic motor 12 driven by pressure oil from the hydraulic pump 11, and a travel control that controls the flow of pressure oil from the hydraulic pump 11 to the hydraulic motor 12. A valve 13 and a pilot hydraulic circuit 20 for operating the control valve 13 are provided. The pilot hydraulic circuit 20 is switched to a forward position, a reverse position, and a neutral position by operating a pilot hydraulic power source 21, a pilot valve 22 that generates a pilot pressure corresponding to the operation amount of the accelerator pedal 22a, and a forward / reverse selector switch (not shown). The forward / reverse switching valve 23 is provided.

  In FIG. 3, when the solenoid 23a of the forward / reverse switching valve 23 is excited, the forward / reverse switching valve 23 is switched to the forward position (F position), and when the solenoid 23b is excited, it is switched to the reverse position (R position). When the accelerator pedal 22a is operated while the forward / reverse switching valve 23 is switched to the forward position or the reverse position, the pilot pressure corresponding to the operation amount acts on the control valve 13, and the control valve 13 travels from the neutral position shown in the figure. Switch to position. As a result, pressure oil is supplied from the hydraulic pump 11 to the hydraulic motor 12, the hydraulic motor 12 is driven, and the vehicle travels. In a state where the forward / reverse switching valve 23 is switched to the neutral position, the control valve 13 is switched to the neutral position and the drive of the hydraulic motor 12 is blocked.

  FIG. 4 is a block diagram showing the configuration of the prime mover control device according to the present embodiment. The controller 30 includes an arithmetic processing unit having a CPU, ROM, RAM, and other peripheral circuits. An engine control unit (ECU) is also included in the controller 30. The controller 30 receives signals from the brake switch 31, the pedal operation amount detector 32, the EC dial 33, and the changeover switch 34.

  The engine speed is adjusted, for example, by driving a governor (not shown). The governor is driven by the rotation of a pulse motor (not shown). The governor lever angle is detected by a potentiometer (not shown), and based on this governor lever angle, the pulse motor is servo-controlled by a signal from the controller 30 so that the engine speed becomes a target speed described later.

  The brake switch 31 is a switch for commanding the operation / non-operation of the work brake and the operation / non-operation of the parking brake, and can be switched to three positions: a work brake position, a parking brake position, and an off position. When the brake switch 31 is switched to the work brake position, the brake pressure is applied to a brake cylinder (not shown), and the work brake (service brake) is activated. When the brake switch 31 is switched to the off position, the action of the brake pressure on the brake cylinder stops and the work brake is released. Even when the brake switch 31 is off, a brake pressure corresponding to the amount of operation of a brake pedal (not shown) can be applied to the brake cylinder, whereby the service brake can be operated.

  The parking brake is a so-called negative brake, and the parking brake is released when a brake releasing pressure is applied to the brake releasing cylinder. When the brake switch 31 is switched to the parking brake position, the action of the brake release pressure stops, the brake release cylinder is pushed by the spring force, and the parking brake is activated. When the brake switch 31 is switched to the off position, the parking brake is released.

  The brake switch 31 is provided in the vicinity of the steering wheel in the driver's cab and is switched to the work brake position during work, to the parking brake position during parking, and to the off position during travel. As a result, the mode is set to the work mode when working, the parking mode when parking, and the travel mode when traveling.

  The pedal operation amount detector 32 is composed of, for example, a pressure sensor that detects a pilot pressure p corresponding to the operation amount of the accelerator pedal 22a, and the operation amount of the accelerator pedal 22a is detected from the pressure detection value p. The target rotational speed of the engine 1 is set by operating the accelerator pedal 22a. FIGS. 5A and 5B are diagrams showing the relationship between the detected pressure value p and the target rotational speeds N1 and N2. FIG. 5A shows a target rotational speed characteristic L1 suitable for work, and FIG. 5B shows a target rotational speed characteristic L2 suitable for traveling.

  In any of the characteristics L1 and L2, the target rotational speeds N1 and N2 are increased as the pressure detection value p is increased. The idle speed NL2 (travel idle speed) of the characteristic L2 is set higher than the idle speed NL1 (work idle speed) of the characteristic L1. Further, the maximum rotational speed Nb of the characteristic L2 is set higher than the maximum rotational speed Na of the characteristic L1, and the slope of the characteristic L2 is steeper than the slope of the characteristic L1.

  The EC dial 33 is provided in the driver's cab, and the target rotational speed Ns of the engine 1 is set according to the dial operation amount s. FIG. 5C is a diagram showing the relationship between the dial operation amount s and the target rotational speed Ns. According to the characteristic L3 in FIG. 5C, the idle speed is set equal to the work idle speed NL1, and the maximum speed is also set equal to the maximum speed Nb of the characteristic L2.

  The changeover switch 34 is a switch for changing over an input mode of the target rotational speed. That is, when the changeover switch 34 is switched to the pedal mode position, target rotational speeds NL1 and NL2 are input by operating the accelerator pedal 22a, and when the switch 34 is switched to the dial mode position, the target rotational speed Ns is input by operating the EC dial 33. The

  FIG. 6 is a flowchart illustrating an example of processing executed by the controller 30. For example, the processing is started when an engine key switch is turned on. In step S1, signals from the brake switch 31, pedal operation amount detector 32, EC dial 33, and changeover switch 34 are read. In step S2, the operation of the brake switch 31 is determined. If it is determined that the brake switch 31 is at the work brake position, the process proceeds to step S3.

  In step S3, the operation of the changeover switch 34 is determined. If it is determined that the changeover switch 34 is in the pedal mode position, the process proceeds to step S5, and based on the characteristic L1 in FIG. 5A, the target rotational speed N1 corresponding to the operation amount (pressure detection value p) of the accelerator pedal 22a is set. Set. If it is determined that the changeover switch 34 is in the dial mode position, the process proceeds to step S6, and a target rotational speed Ns corresponding to the operation amount s of the EC dial 33 is set based on the characteristic L3 in FIG.

  If it is determined in step S2 that the brake switch 31 is in the off position, the process proceeds to step S4. In step S4, the operation of the changeover switch 34 is determined. If it is determined that the changeover switch 34 is in the pedal mode position, the process proceeds to step S7, and based on the characteristic L2 in FIG. 5B, the target rotational speed N2 corresponding to the operation amount (pressure detection value p) of the accelerator pedal 22a is set. Set. If it is determined that the changeover switch 34 is in the dial mode position, the process proceeds to step S6, and a target rotational speed N3 corresponding to the operation amount s of the EC dial 33 is set based on the characteristic L3 in FIG. In step S8, a control signal is output to the pulse motor for driving the governor of the engine 1, and the engine speed is controlled to the target speed determined in steps S5 to S7.

  On the other hand, if it is determined in step S2 that the brake switch 31 is at the parking brake position, the process proceeds to step S9. In step S9, a control signal is output to the pulse motor for driving the governor, and the engine speed is controlled to a predetermined idle speed NL3 (parking idle speed). Here, the parking idle rotation speed NL3 is the minimum rotation speed that is not stalled, and is set lower than the work idle rotation speed NL1.

  The operation of the present embodiment is summarized as follows. When the brake switch 31 is operated to the off position, the work brake and the parking brake are respectively released and the traveling mode is set. When the changeover switch 34 is operated to the pedal mode position in this state, the engine speed is controlled in accordance with the operation amount of the accelerator pedal 22a based on the characteristic L2 in FIG. 5B (step S7 → step S8). When the operation of the accelerator pedal 22a is stopped, the engine speed becomes the traveling idle speed NL2. At this time, the traveling idle rotation speed NL2 is set higher than the work idle rotation speed NL1, and the slope of the characteristic L2 is steep, so that good acceleration during traveling can be obtained. When the changeover switch 34 is operated to the dial mode position, the engine speed is controlled in accordance with the dial operation amount (step S6 → step S8). Thus, the engine speed during traveling can be kept constant without operating the accelerator pedal 22a.

  When the brake switch 31 is operated to the work brake position, the work brake is activated and the work mode is set. When the changeover switch 34 is operated to the pedal mode position in this state, the engine speed is controlled in accordance with the operation amount of the accelerator pedal 22a based on the characteristic L1 in FIG. 5A (step S5 → step S8). When the operation of the accelerator pedal 22a is stopped, the engine speed becomes the work idle speed NL1 lower than the traveling idle speed NL2. For this reason, the fuel consumption at the time of work can be improved. When the changeover switch 34 is operated to the dial mode position, the engine speed is controlled in accordance with the dial operation amount (step S6 → step S8). As a result, the engine speed during operation can be kept constant without operating the accelerator pedal 22a.

  When the brake switch 31 is operated to the parking brake position, the parking brake is activated and the parking mode is set. In this state, regardless of the operation of the accelerator pedal 22a or the operation of the EC dial 33, the engine speed is controlled to the parking idle speed NL3 that is lower than the work idle speed NL1 (step S9). For this reason, when neither running nor work is performed, the engine speed can be minimized and fuel consumption can be improved. Since the engine speed is reduced only by switching the brake switch 31, troublesome operations for setting the speed, such as pedal operation and dial operation, are not necessary, and it is easy to use. When the brake switch 31 is operated from the parking brake position to the off position or the work brake position, the engine speed increases, and the engine speed is controlled to the target speed by pedal operation or dial operation.

According to the present embodiment, the following operational effects can be achieved.
(1) When the brake switch 31 is switched to the parking brake position, the parking brake is activated, and the engine speed is lower than the traveling idle speed NL2 regardless of the operation of the accelerator pedal 22a or the EC dial 33, And it controlled to the parking idle rotational speed NL3 lower than the work idle rotational speed NL1. Thereby, the engine speed at the time of parking mode can be suppressed to the minimum, and fuel consumption can be improved.
(2) Since the engine speed is controlled to the parking idle speed NL3 without requiring the operation of the gate lock lever 6, the engine speed can be minimized even before the passenger gets off. . In addition, in order to reduce the engine speed, it is not necessary to operate the gate lock lever 6 before getting off the vehicle, and the gate lock lever 6 can satisfactorily detect the passenger getting off state.
(3) Since the target rotational speed can be set by operating the accelerator pedal 22a and the EC dial 33, and any one of the target rotational speeds can be selected by the changeover switch 34, the running performance and workability can be improved. .

  In the above embodiment, when the brake switch 31 is switched to the parking brake position, the engine speed is controlled to the parking idle speed NL3. However, this speed control is prohibited during the warm-up operation. May be. In this case, for example, as shown in FIG. 7, a temperature detector 35 for detecting the engine coolant temperature may be newly provided, and the controller 30 may determine whether or not the warm-up operation is necessary based on the temperature detection value. Even when the brake switch 31 is switched to the parking brake position, if it is determined that the warm-up operation is necessary, for example, the process proceeds to step S4 in FIG. 6 and it is determined that the warm-up operation is not necessary. Then, what is necessary is just to make it progress to the process of step S9. Thereby, warm-up can be performed promptly.

  In the above embodiment, the engine target speed (first engine speed) is set by operating the accelerator pedal 22a as the first setting means, and the engine is operated by operating the EC dial 33 as the second setting means. Although the target rotational speed (second engine rotational speed) is set, the configuration of the rotational speed setting means is not limited to this. The pedal switch and the dial mode are switched by the changeover switch 35. However, the maximum value may be selected from the target rotation speed by the pedal operation and the target rotation speed by the dial operation. Not limited to.

  In the above embodiment, the parking idle speed NL3 is set lower than the work idle speed NL1, but it is sufficient to set it at least lower than the traveling idle speed NL2. For example, the parking idle speed NL3 is set to the work idle speed NL1. May be equal. That is, if the engine speed is controlled so that the parking idle speed NL3 is lower than the traveling idle speed NL2, regardless of the speed setting by pedal operation or dial operation when the parking mode is selected, Any configuration of the rotational speed control means may be used. Although the parking mode, the work mode, and the traveling mode are selected by the brake switch 31, the mode selection means is not limited to this.

  Although the said embodiment was applied to the wheel-type hydraulic excavator, it is applicable also to other wheel-type work vehicles, such as a wheel loader and a forklift. That is, as long as the features and functions of the present invention can be realized, the present invention is not limited to the prime mover control device for a work vehicle according to the embodiment.

DESCRIPTION OF SYMBOLS 1 Engine 11 Hydraulic pump 12 Traveling hydraulic motor 22a Accelerator pedal 31 Brake switch 32 Pedal operation amount detector 33 EC dial 34 Changeover switch 35 Temperature detector NL1 Work idle speed NL2 Travel idle speed NL3 Parking idle speed

Claims (4)

A hydraulic pump driven by an engine;
A traveling hydraulic actuator driven by pressure oil from the hydraulic pump;
A mode selection means for selecting a parking mode in which the parking brake is activated, a work mode in which the work brake is activated, and a travel mode in which both the parking brake and the work brake are inoperative;
A rotation speed setting means for setting the engine target rotation speed in the travel mode and the engine target rotation speed in the work mode, respectively.
When the travel mode or the work mode is selected by the mode selection means, the engine speed is controlled to be the engine target speed set by the speed setting means, and the parking mode is selected. Regardless of the setting by the rotational speed setting means, a rotational speed control means for controlling the engine rotational speed so that the parking idle rotational speed is lower than at least the traveling idle rotational speed that is the idle rotational speed in the traveling mode. A prime mover control device for a work vehicle, comprising: In the motor | power_engine control apparatus of the working vehicle of Claim 1,
The rotation speed setting means sets a work idle rotation speed, which is an idle rotation speed in the work mode, to be lower than the traveling idle rotation speed and higher than the parking idle rotation speed. A motor control device for a vehicle. In the motor | power_engine control apparatus of the working vehicle of Claim 1 or 2,
The rotation speed setting means includes
First setting means for setting the first engine speed by operating the first operating member;
A second setting means for setting a second engine speed by operating the second operating member;
A prime mover control device for a work vehicle, comprising: a rotation speed selection unit that sets the engine target rotation speed to either the first engine rotation speed or the second engine rotation speed. In the motor | power_engine control apparatus of the working vehicle of any one of Claims 1-3,
It further comprises a warm-up determination means for determining whether or not a warm-up operation is necessary,
When the warm-up determination means determines that the warm-up operation is necessary, the engine speed control means sets the engine target speed set by the engine speed setting means even when the parking mode is selected by the mode selection means. A motor control device for a work vehicle, characterized in that the engine speed is controlled.

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