JP2002054471A - Engine rotation control device for work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a cost by comparing a conventional machine operation type and an electric operation type with each other, improve reliability, and improve management, in an engine rotation control device for a work vehicle provided with an engine control unit, such as a governor, annexed to an on- vehicle engine and controlling its rotation, and a controller on the work machine side disposed near the work machine. SOLUTION: A controller C on the work machine side comprises an operation part C1 capable of inputting operation by a worker; and a control circuit part C2 to output an electric signal for control capable of controlling an engine control unit G according to an operation input to the operation part C1. The output side of the control circuit part C2 is connected to the engine control unit G through electric wires L1-L3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine capable of driving a work vehicle, particularly a work machine mounted on a vehicle, an engine control unit such as a governor attached to the engine and controlling the rotation thereof, and The present invention relates to an engine rotation control device for a work vehicle including a work machine-side controller provided.

[0002]

2. Description of the Related Art Conventionally, an engine rotation control device in the above-mentioned work vehicle includes an engine control unit, for example, by interlocking an operated part of an engine control unit (for example, a governor control lever) and a work machine side controller. A machine-operated type in which a unit is remotely controlled is known.

[0003]

In the above-mentioned machine-operated type, an interlocking connection mechanism for mechanically interlocking an operated portion of an engine control unit and a controller of a work machine is provided with a limited body space of a work vehicle. There is a problem that it is not easy to manage the equipment inside and the equipment cost increases.

In order to solve such a problem, an actuator (for example, a motor,
Rotary solenoids are electrically controlled remotely by the working machine controller, and the movement of the actuator is converted into a voltage signal by a rotation control volume (for example, a potentiometer), and the engine control unit is controlled by the voltage signal. Some have already been proposed.

However, in this proposal, a motor, an actuator such as a rotary solenoid, and a rotation control volume for converting the movement of the actuator into a voltage signal, which are unnecessary in the mechanical type, are specially required. There was a problem with reliability.

[0006] The present invention has been proposed in view of the above,
It is an object of the present invention to provide an engine rotation control device for a work vehicle having a simple structure, which can solve the problems of the conventional device at once.

[0007]

In order to achieve the above object, an invention according to claim 1 is provided with a working machine mounted on a vehicle, an engine mounted on the same car capable of driving the working machine, and an engine attached to the engine. An engine control unit for controlling rotation,
A work machine-side controller disposed near the work machine, the work machine-side controller comprising: an operation unit that allows an operator to perform an operation input; and the engine control unit according to an operation input to the operation unit. And a control circuit for outputting a control voltage signal. An output side of the control circuit is connected to the engine control unit via an electric wire.

According to the above feature, since the voltage signal from the control circuit section of the work machine-side controller is output to the engine control unit through the electric wire, a motor conventionally required for electrically controlling the engine control unit is provided. Therefore, an actuator such as a rotary solenoid and a rotation control volume such as a potentiometer are not required, and the number of components in the entire system is reduced, which is extremely advantageous in terms of cost and reliability. In addition, since the work machine-side controller and the engine control unit need only be connected by electric wires, it is easier to handle than when the engine control unit is mechanically controlled, and can be installed in a narrow body space. The above restrictions are greatly reduced.

According to a second aspect of the present invention, in addition to the features of the first aspect, the work implement-side controller electrically insulates the control circuit section and the engine control unit from each other while electrically insulating the control circuit section from the engine control unit. An insulation / signal transmission circuit for transmitting / receiving a voltage signal is provided, and an output side of the insulation / signal transmission circuit is connected to the engine control unit via the electric wire. According to this feature, even if the work implement-side controller and the engine control unit are far apart, there is no risk of being affected by noise due to a difference in ground potential between their mounting positions, and the accuracy of control of the engine control unit is improved. I do.

According to a third aspect of the present invention, in addition to the features of the second aspect, a reference voltage on the engine control unit side is used as a power supply on the output side of the insulation / signal transmission circuit. I do. The use of this reference voltage, combined with the special provision of insulation and signal transmission circuits, further improves control accuracy, and requires a special power supply circuit on the working machine side to supply a reference voltage. And cost savings.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below based on embodiments of the present invention illustrated in the accompanying drawings.

In the accompanying drawings, FIG. 1 is a schematic explanatory view of a refuse collection vehicle according to one embodiment of the present invention, FIG. 2 is a schematic relation diagram between a working machine-side controller and an electronic governor, and FIG. It is a circuit diagram between a side controller and an electronic governor.

First, in FIG. 1, a refuse collection vehicle V as a working vehicle is provided with a traveling and working engine E on a vehicle body F.
And a dust storage box B; a dust input box Br connected to the rear of the dust storage box B; And a dust pushing device A for pushing the dust.

The dust pushing device A constitutes the working machine of the present invention, and its structure is conventionally well-known, and has no relation to the gist of the present invention, so that a detailed description is omitted. .

The power from the engine E can be transmitted to driving wheels W via a clutch and a transmission (both not shown) when the vehicle is running. When the vehicle stops, the power from the engine E can be transmitted to the on-board hydraulic pump P via the power take-out device PTO at any time. The output hydraulic pressure of the hydraulic pump P is supplied to the hydraulic actuators A1 and A2 of the dust pushing device A to drive the dust pushing device A.

The engine E is provided with an electronic governor G as an engine control unit capable of controlling the number of revolutions of the engine E electronically. The electronic governor G controls the fuel injection amount and the injection timing of the engine E in accordance with the magnitude of the voltage signal input to the electronic governor, so that the engine speed can be controlled. Since the structure of such an electronic governor G is conventionally well-known, further description is omitted. Note that an electronic fuel injection control device may be used as the engine control unit instead of the electronic governor.

In controlling the driving of the dust pushing device A in accordance with the work load, the number of revolutions of the engine E, and hence the output, can be remotely controlled by the work machine controller C by an operator. The controller C is disposed at an appropriate place in the vehicle body near the work machine, that is, the dust pushing device A (in the illustrated example, the outer wall of the dust bin Br).

As shown in FIGS. 2 and 3, the controller C includes an operation unit C1 which can be manually operated by an operator, and a control voltage applied to the electronic governor G in response to an operation input to the operation unit C1. And a control circuit section C2 for outputting a signal. The output side of the control circuit section C2 is sequentially connected to an insulation / signal transmission circuit C3 and a smoothing circuit C4, which will be described later, and furthermore, the electronic governor G is connected via a plurality of electric wires L1 to L3.
Connected to.

The operation section C1 is provided with a plurality of selection switches SW1 to SW8 which can be arbitrarily selected and operated by an operator, in addition to a main power switch (not shown). To SW8 are dial-operated so that they can be selectively switched by a common dial. The plurality of selection switches SW1 to SW
Numeral 8 corresponds to a plurality of preset rotational speed setting values N1 to N8 of the engine E. By appropriately selecting the selection switches SW1 to SW8, the rotational speed of the engine E is set to the plurality of rotational speed setting values N1 to N8. A signal for selecting at any time from N1 to N8 is output to the control circuit unit C2.

The control circuit section C2 has a plurality of signal input sections i1 to i8 for receiving ON signals of the plurality of selection switches SW1 to SW8, respectively, and a signal is applied to any one of the signal input sections i1 to i8. A different control voltage signal is output to the electronic governor G depending on whether it has been input, and the engine E
Is controlled to the set number of revolutions.

In the illustrated example, the control circuit section C2 is P
A WM control circuit is used. The “PWM control” is an abbreviation of pulse width modulation (Palus Width Modulation) control, and the output pulse width (that is, the output pulse width (that is, the DC level) according to the magnitude of the input signal (DC level) while keeping the switching frequency (period) constant. By changing the on-pulse conduction width), the control is performed so that the energy supplied to the control target is controlled as a result, and the operation control of the control target is performed.
Since the specific method of PWM control is well known,
The description of the circuit structure is omitted.

In the control circuit section C2 of the illustrated example, a pulse-shaped voltage signal having a different pulse width and a constant cycle is output to the signal output section O depending on which of the signal input sections i1 to i8 the signal is input to. It can output more. In this case, the on-pulse time of the pulse voltage signal is set to be longer as the selection switches SW1 to SW8 having the larger rotation speed setting values N1 to N8 are turned on.

The work machine-side controller C has an insulation / signal transmission circuit C3 for electrically insulating the control circuit section C2 and the electronic governor G while transmitting and receiving a voltage signal therebetween. And a smoothing circuit C4 for smoothing the output voltage signal of the insulation / signal transmission circuit C3.

In the illustrated example, the insulation / signal transmission circuit C3 includes a photocoupler PC and a transistor T for amplifying and applying an output voltage signal from the control circuit unit C2 to a coupler input side of the photocoupler PC. have. This transistor T has a control circuit section C at its base.
The power supply circuit 10 connected to the coupler input side of the photocoupler PC is turned on in response to the action of the output voltage signal from the light emitting element 2, and the light emitting element Di described below emits light.

As is well known, the photocoupler PC includes a light emitting element Di that shines in response to an input voltage signal applied to the coupler input side, receives light emitted from the light emitting element Di, and outputs an output voltage signal to the coupler output side. A light receiving element Do is provided between the coupler input side (light emitting element Di) and the output side (light receiving element Do). The parts are placed in an electrically insulated state.

The first terminal p1 on the output side of the insulation / signal transmission circuit C3 (ie, the coupler output side of the photocoupler PC)
And the reference voltage output terminal t3 of the electronic governor G are connected via a voltage supply wire L3. From the reference voltage output terminal t3, the output voltage of a reference power supply provided on the electronic governor G side, that is, the reference voltage Vref is supplied to the output side (first terminal p1) of the insulation / signal transmission circuit C3.

The electronic governor G is provided with a signal input terminal t2 and a ground terminal t1, and a signal wire L2 and a ground wire L1 extending from these terminals t2 and t1, respectively.
Is the output side of the insulation / signal transmission circuit C3 via the smoothing circuit C4 (ie, the coupler output side of the photocoupler PC).
Is connected to the second terminal p2.

The smoothing circuit C4 comprises a low-pass filter combining a capacitor and a resistor, as is well known in the art, and is used to smooth the output voltage signal of the photocoupler PC.

The working machine, ie, the working machine side controller C near the dust pushing device A, and the electronic governor G near the engine E are relatively far apart. In this case, since it is only necessary to simply connect the three electric wires L1 to L3, it is easy to route the connecting means therebetween, and it is possible to greatly reduce restrictions on installation in a narrow body space.

Next, the operation of the above embodiment will be described. When the vehicle is stopped and the dust pushing device A serving as a working machine performs the intended dust pushing work, the power of the engine E is transmitted to the hydraulic pump P via the power take-out device PTO, and the pump P is operated. Drive. As a result, the hydraulic oil discharged from the pump P is transferred to each hydraulic actuator A of the dust pushing device A.
1 and A2 to drive them. The operation of each of the actuators A1 and A2 is automatically controlled by a controller (not shown) based on a predetermined control program in accordance with a driving operation of an operator.

In controlling the driving of the dust pushing device A in accordance with the work load in this way, the operator can remotely control the rotation speed of the engine E, and thus the output, by the work machine controller C. In this case, the controller C
Selection switches SW1 to SW in the operation unit C1
By appropriately selecting one of the eight, the number of rotations of the engine E can be selected from a plurality of rotation number setting values N1 to N8 at any time.

According to the selection, a pulse voltage signal having a predetermined pulse width is output from the control circuit section C2 (signal output section O) of the controller C.
Is once converted into an optical signal in the photocoupler PC of the insulation / signal transmission circuit C3, and then converted again into a voltage signal.
This becomes a voltage signal smoothed by the smoothing circuit C4 and sent to the electronic governor G. In the electronic governor G, the fuel injection amount and the injection timing of the engine E are adjusted according to the level of the smoothed voltage signal, and the engine speed is controlled to the selected set value.

As described above, the work machine-side controller C includes the operation unit C1 and the control circuit unit C2 for performing PWM control of the electronic governor G in accordance with the operation input to the operation unit C1, and the voltage signal from the control circuit unit C2. Is output to the electronic governor G side, so that a motor, an actuator such as a rotary solenoid, and a rotation control volume such as a potentiometer that are conventionally required for electrically controlling the electronic governor G are unnecessary, and the entire system is not required. Since the number of components is reduced and simplified, it is very advantageous in terms of cost and reliability.

Further, as shown in the illustrated example, the working machine-side controller C includes an insulation / signal transmission circuit C3 which electrically insulates the control circuit section C2 and the electronic governor G and transmits and receives a voltage signal therebetween. The output side of the insulation / signal transmission circuit C3 (the output side of the photocoupler PC in the illustrated example) is connected to the electric wire L.
Since it is connected to the electronic governor G through 1 to L3, even if the work implement controller C and the electronic governor G are separated,
There is no longer a risk of being affected by noise due to a difference in ground potential between those mounting positions, and the control accuracy of the electronic governor G can be improved.

As shown in FIG.
Since the reference voltage Vref of the electronic governor G is supplied to the output side of the electronic governor 3, the use of the reference voltage Vref of the electronic governor enables the control accuracy to be further improved in combination with the special provision of the insulation / signal transmission circuit C3. Improvement is achieved, and it is not necessary to provide a dedicated power supply circuit for supplying the reference voltage on the working machine side, thereby reducing costs.

Although the embodiment of the present invention has been described in detail, the present invention is not limited to the above-described embodiment, and various small design changes can be made. For example, in the above-described embodiment, a dust collection vehicle equipped with a dust pushing device (working machine) is illustrated as the work vehicle V. However, in the present invention, the work vehicle is not limited to the dust collection vehicle, and the power of the traveling engine is controlled. Various other work vehicles which are taken out by a power take-off device (PTO) to drive a work machine mounted on a vehicle, such as a mixer truck, a concrete pump truck, a tank truck, a powder carrier,
It is also applicable to crane trucks and the like.

In the above embodiment, the control circuit unit C2 of the working machine controller C is adapted to perform the PWM control of the electronic governor G in accordance with the operation input to the operation unit C1. , A suitable control method other than the PWM control can be used. For example, a voltage signal for control is generated in response to an operation input to the operation unit C1 using a DA converter element or the like, and this voltage signal is transmitted via electric wires L1 to L3. Output to the electronic governor G side.

In the above embodiment, the smoothing circuit C4 is provided in the working machine-side controller C. However, in the present invention, the smoothing circuit C4 is not provided in the working machine-side controller C but is provided near the electronic governor G. May be provided.

In the above embodiment (claim 3), the insulation
The electronic governor G is used as a power source on the output side of the signal transmission circuit C3.
In the present invention (claims 1 and 2), a dedicated power supply circuit is provided on the working machine side,
Insulate the reference voltage from the dedicated power supply circuit and signal transmission circuit C
3 may be supplied to the output side. In this case,
The voltage supply wire L3 becomes unnecessary, and the insulation / signal transmission circuit C3 and the electronic governor G are connected only by the signal wire L2 and the ground wire L1.

[0040]

As described above, according to the present invention, the work implement controller controls the operation unit and outputs the control voltage signal to the engine control unit through the electric wire in accordance with the operation input to the operation unit. With the circuit section, motors, actuators such as rotary solenoids, and rotary control volumes such as potentiometers, which were conventionally required to electrically control the engine control unit, are unnecessary, and the components of the entire system are eliminated. Since it is reduced, it is very advantageous in terms of cost and reliability. In addition, since it is only necessary to connect the working machine side controller and the engine control unit with electric wires, it is easier to handle than when the engine control unit is mechanically controlled, and it can be installed in a narrow body space. Can be greatly reduced.

According to a second aspect of the present invention, the work machine-side controller electrically insulates the control circuit unit and the engine control unit from each other while transmitting and receiving a voltage signal therebetween. A transmission circuit is provided, and the output side of the insulation / signal transmission circuit is connected to the engine control unit via the electric wire. Therefore, there is no possibility of being affected by noise due to the above, and the accuracy of control of the engine control unit can be improved.

According to the third aspect of the present invention, since the reference voltage on the engine control unit side is used as the power supply on the output side of the insulation / signal transmission circuit, the insulation / signal transmission circuit is utilized by using this reference voltage. In addition to the special configuration described above, the control accuracy can be further improved, and the cost can be reduced because it is not necessary to provide a special power supply circuit for supplying the reference voltage on the working machine side.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a refuse collection vehicle according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a relationship between a work implement controller and an electronic governor;

FIG. 3 is a circuit diagram between a working machine-side controller and an electronic governor.

[Explanation of symbols]

 A: Dust pushing device (working machine) C: Working machine-side controller C1: Operation unit C2: Control circuit unit E: Engine G: Electronic governor (engine control) Unit) L1 to L3 ... Electric wire V ... Dust collection vehicle (working vehicle) Vref ... Reference voltage

Claims (3)

[Claims] 1. An in-vehicle work machine (A), an in-vehicle engine (E) capable of driving the work machine (A), and an engine control unit attached to the engine (E) and controlling its rotation (G) and a work machine-side controller (C) arranged near the work machine (A), and the work machine-side controller (C) is provided with an operation unit (C1 ) And a control circuit section (C2) for outputting a control voltage signal to the engine control unit (G) in accordance with an operation input to the operation section (C1).
The output side of the control circuit section (C2) is connected to the engine control unit (G) via electric wires (L1 to L3). 2. The work machine-side controller (C) for transmitting and receiving a voltage signal between the control circuit unit (C2) and the engine control unit (G) while electrically insulating the control circuit unit (C2) from the engine control unit (G). It has an insulation and signal transmission circuit (C3),
The engine rotation in a work vehicle according to claim 1, characterized in that the output side of the insulation / signal transmission circuit (C3) is connected to the engine control unit (G) via the electric wires (L1 to L3). Control device. 3. The reference voltage (Vref) on the engine control unit (G) side as a power supply on the output side of the insulation / signal transmission circuit (C3). An engine rotation control device for a work vehicle.