JPS61152930A - Governor device for work vehicle - Google Patents

Abstract

PURPOSE:To simplify switching operation by switching the governor control mode to the work vehicle traveling mode when a foot accelerator lever is operated so as to touch the high speed side, by means of turning operation of a hand accelerator lever to the high speed side. CONSTITUTION:Both a hand accelerator lever 19 and a foot accelerator pedal 20 are connected as a acceleration adjusting means to a control circuit 18 which selectively sets an on-the-road traveling mode or an at-work traveling mode. When the hand accelerator lever 19 is operated to an appropriate accelerating position, an arm 23 touches and operates a lever 21, and a sensor 24 detects the touch. Following the detection of the touch by the sensor 24, the governor control mode is switched to the at-work traveling mode. With this, the switching operation can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention mainly relates to a governor device used in a diesel engine-equipped agricultural working vehicle such as an agricultural tractor or combine harvester.

[Conventional technology]

The governor devices that control the fuel injection pumps of diesel engines are categorized by characteristic patterns: all-speed governors, which can control the speed in all rotation ranges from idling to maximum speed, and There is a minimum/maximum speed governor that exerts speed regulating action only in the low speed rotation range and high speed rotation range, and does not perform the speed regulating action in the middle rotation range, in order to prevent the rotation speed from exceeding the speed range.

The former all-speed governor is used in the above-mentioned agricultural work vehicles, which require stable constant-speed running and constant-speed drive of working equipment regardless of load fluctuations, and also provides smooth acceleration and deceleration in response to accelerator adjustment. A minimum/maximum speed governor is suitable for cars that require performance.

[Problem that the invention seeks to solve]

By the way, in recent years, there has been a strong trend towards faster speeds for the above-mentioned agricultural work vehicles due to improvements in work efficiency and mobility.
It is becoming possible to fully handle not only work in the field but also high-speed transportation work on the road.

However, as mentioned above, the governor device installed on the engine of agricultural work vehicles was an all-speed governor that was suitable for the main work in the field.
The sense of acceleration and deceleration (drivability) when driving on the road was poor.

This invention solves the above problem by employing a so-called electronically controlled governor that controls the operation of the injection amount adjustment mechanism using an electric actuator, thereby making it possible to utilize two types of governor characteristics suitable for work driving and road driving. In addition, it is possible to simplify the configuration of the accelerator set means especially in the work driving mode, to make it easy to operate, and to easily transition from the work driving mode to the road driving mode. It has been made possible.

[Means for solving problems]

In the present invention, the fuel injection amount adjustment mechanism of the installed diesel engine is configured to be operated by an electric actuator that is electrically linked to a manually operated accelerator adjustment tool via a control circuit, and the mechanism is configured to be operated by an electric actuator that is electrically linked to an accelerator adjustment tool that is manually operated. Controls a road driving mode in which fuel is controlled using a governor characteristic set to a torque curve with a small torque fluctuation rate, and a work driving mode in which fuel is controlled using a governor characteristic set to a torque curve with a large torque fluctuation rate in response to engine speed fluctuations. The configuration is configured so that both modes can be selected by setting in a circuit, and the accelerator adjustment device includes a hand accelerator lever that can be held at any operating position and a foot accelerator pedal that automatically returns to the low speed side. The accelerator pedal is equipped with a means for outputting an accelerator setting signal according to the depression of the accelerator pedal, and a mechanical mechanism is provided so that when the hand accelerator lever is operated to the high-speed side, the foot accelerator pedal is brought into contact with the accelerator pedal to the high-speed side. When the sensor detects that the foot accelerator pedal is in contact with the hand accelerator lever, the governor control mode is automatically switched to road driving mode, and if not, the governor control mode is automatically switched to road driving mode. The feature is that it is configured so that it can be switched automatically.

[For production]

According to the above configuration, by releasing the foot accelerator pedal and holding the hand accelerator lever at a desired operating position, the work driving mode is set based on the accelerator set amount of the foot accelerator pedal that is in contact with the lever. Governor control is performed at Governor control is performed. Further, if the foot accelerator pedal is depressed during the work drive mode and disconnected from the hand accelerator lever, the road drive mode is set only while the foot accelerator pedal is depressed.

〔Effect of the invention〕

Therefore, according to the present invention, governor control with characteristics suitable for road driving and work driving can be arbitrarily selected, and regardless of the work driving mode or the road driving mode, the accelerator setting signal is output from the foot accelerator system. Since the signal is obtained from the means, a dedicated accelerator setting signal output means for the hand accelerator system is not required, and the configuration becomes simple.

Further, even if the vehicle is in the work travel mode, as long as the foot accelerator pedal is depressed, the accelerator will be increased and the vehicle will enter the road travel mode, which can be conveniently used when quickly moving the work position during work travel.

〔Example〕

The case where the present invention is applied to an agricultural tractor will be described below.

Diesel engine (2) mounted on the tractor body (1)
) is transmitted to the transmission case (4) via the main clutch housing (3), where the gear is changed as appropriate and transmitted to the rear wheels (5) or the front and rear wheels (6), (5), Live PTO independent of transmission system
A rotary rotary is an example of a working device in which working power is branched and transmitted to the rear PTO shaft (7) via a transmission system, and is connected to the rear of the vehicle body by a hydraulic lift arm (8) and a three-point link mechanism (9) so that it can be raised and lowered. The tilling device (10) is the PTO
It is designed to be driven by the output from the shaft (7).

A control rack (12), which is a fuel injection adjustment mechanism for a fuel injection pump (11) installed in the engine (2), is controlled by an electronic governor.

That is, the control rack (12) is connected to a solenoid (13) that is displaced with a stroke proportional to the excitation current, and the position of the control rack (12) is continuously controlled by a stroke sensor (14) using a differential transformer. a coil sensor (17) that is detected by
The engine speed is detected by these sensors (1
4) The position of the control rack (12) is controlled based on the information in (17) and a separately artificially set accelerator setting value.

This electronic governor is controlled via a control circuit (18) using a microcomputer, and a block diagram thereof is shown in FIG.

This electronic governor uses a hand accelerator lever (19) that can be frictionally held at any operating position over the entire range from the idling position to the highest speed position, and a hand accelerator lever (19) that can be held at any operating position over the entire range from the idling position to the highest speed position. A foot accelerator pedal (20) is used, which can be depressed arbitrarily over the entire range of positions, and which automatically returns to the idling side.

The amount of rotation of the lever (21) linked to the foot accelerator pedal (20), that is, the amount of accelerator adjustment, is output from the potentiometer (22).

Further, an arm (23) extending from the hand accelerator lever (19) is provided so as to be able to come into contact with the lever (21),
By operating the hand accelerator lever (19) to the high speed side, the foot accelerator pedal (20) is brought into contact with the high speed side. The sensor (24) is configured to detect contact between the lever (21) and the arm (23).

Furthermore, in this electronic governor, two types of governor characteristics are set in advance by the control circuit. One of them, as shown in FIG. 3, is a torque curve that has a small torque fluctuation rate with respect to fluctuations in engine speed, and is mainly used for road driving. The other, as shown in Figure 4, is set to a torque curve that has a large torque fluctuation rate with respect to fluctuations in engine speed, and is mainly used for work driving, and these two governor characteristics are the same as those described later. The following control is performed for each mode.

In the mode using the on-road governor characteristics,
Map control is performed. In other words, in the torque curve shown in FIG. 3, the relationship between the engine speed and the control rank position (torque) is stored in advance as map data for each accelerator setting value, and the potentiometer (
The map control system (25) determines the target rack position (Pl) for the detected engine speed based on the map data corresponding to the accelerator setting value obtained from step 22), and controls the position so that the detected rank position moves toward this target rack position (Pυ). The solenoid (13) is PID controlled.

Further, in the mode using the governor characteristics for work traveling, PID rotation speed control is performed. In other words, the accelerator setting value from the potentiometer (225) is input to the PID rotation speed control system (26) as a target engine rotation speed, and the PID rotation speed is
The target rack position (Pz) is determined by the rotation speed control system (26).
and set the detection rack position to this target rack (6 positions).
The solenoid (13) is controlled by PID so that the solenoid (13) approaches Pz).

Next, the control mode switching operation will be explained.

Switching between the road driving mode and the work driving mode is achieved by selecting either the target rack position (p+) or (Pz) from the map control system (25) and the PID rotation speed control system (26) using the selection system (27). The sensor (24) is connected to the lever (21) and the arm (
23), the target rank position (Po) is selected when contact is not detected, and the target rack position (Pz) is selected when contact is detected. - When the foot accelerator pedal (19) and the foot accelerator pedal (20) are both in the idling position, the lever (21) and the arm (23) are set to avoid contact.

Therefore, when the hand accelerator lever (19) is returned to the idling position, the target rack position (p+) is selected and the vehicle enters the road driving mode. Also, take your foot off the foot accelerator pedal (20) and press the hand accelerator lever (
19) to the appropriate accelerator position, the lever (21)
) is brought into contact with the arm (23), the signal from the potentiometer (22) changes, and the target rack position (Pt) is selected by the contact detection of the sensor (24), thereby entering the work travel mode. Also, even in this work driving mode, if there is enough time to depress the foot accelerator pedal (20), only the lever (21) will rotate toward the high speed side and the contact detection of the sensor (24) will be canceled. to enter road driving mode, and then press the pedal (20
), the accelerator returns to the original setting and returns to the working driving mode when the sensor (24) detects contact.

In addition, minimum rack position control and maximum rack position control are also performed to prevent the engine stop knob and over-rotation. In other words, the lowest rank position (P4) set based on the target rack position (P3) ((PI) or (Pz)) from the selection system (27) and the detected engine speed is determined by the discrimination selection system (28). They are compared and the larger one is selected as the target rack position (P5). Further, as described above, the target rack position (P
5) and the maximum rack position (P6) set based on the detected engine speed are compared in the second discrimination selection system (29), and the smaller one of them is determined as the final target rack position (P6).
), the PID rack position control system (30)
In this way, the rank position is prevented from being operated below the lowest rank position (P4) and above the maximum rack position (P,), thereby preventing engine stop and over-speed development. It has become so.

[Another example]

■ The rank position control form in the road driving mode and the work driving mode is not limited to the above, but the control form in the road driving mode can be map control, and the control form in the working driving mode can be corrected according to the load. It is also possible to use map control. Also, both modes are PID control or PI
Control is also possible.

(2) A DC electric motor (with a speed reducer) may be used instead of the solenoid (13) that drives the control rack (12).

■ It would be convenient to selectively light up mode indicator lamps, etc. in response to switching of control modes.

(2) As the sensor (24) for detecting contact between the lever (21) and the arm (23), a limit switch, reed switch, pressure sensitive element, etc. can be used.

[Brief explanation of drawings]

The drawings show an embodiment of the governor device for a work vehicle according to the present invention, and FIG. 1 is a control block diagram, FIG. 2 is a configuration diagram of the governor device, FIG. 3 is a governor characteristic diagram in road driving mode, and FIG. The figure is a characteristic diagram of the governor in the working driving mode, and FIG. 5 is an overall side view of the agricultural tractor. (2)...Engine, (12)...Fuel injection amount adjustment mechanism, (13)...Actuator, (18)...Control circuit, ( 19)...
...Hand accelerator lever 1 (20)...Foot accelerator pedal, (22)...Accelerator setting value output means, (24)...Sensor.

Claims (1)

[Claims] The fuel injection amount adjustment mechanism (12) of the installed diesel engine (2) is configured to be operated by an electric actuator (13) electrically linked to a manually operated accelerator adjustment tool via a control circuit (18). In addition, there is a road driving mode in which fuel is controlled using a governor characteristic set to a torque curve with a small rate of torque fluctuation relative to engine speed fluctuations, and a fuel control mode is controlled using a governor characteristic set to a torque curve with a large torque fluctuation rate relative to engine speed fluctuations. A control circuit (18) is used to set a work driving mode and a control circuit (18) so that both modes can be selected, and as the accelerator adjustment tool, a hand accelerator lever (
19) and a foot accelerator pedal (20) that automatically returns to the low speed side, the foot accelerator pedal (20) is provided with means (22) for outputting an accelerator setting signal according to the amount of depression thereof, and a hand Accelerator lever (
19) so that the foot accelerator pedal (20) is brought into contact with the foot accelerator pedal (20) toward the high speed side.
, (20) are mechanically linked, and the foot accelerator pedal (
20) is operated in contact with the hand accelerator lever (19) by the sensor (24), the governor control mode is automatically switched to the road driving mode,
A governor system for a work vehicle configured to automatically switch to road driving mode when the vehicle is not in use.