JPS61108838A - Governor for working vehicle - Google Patents

Abstract

PURPOSE:To improve drivability especially in running on roads by employing a so-called electronic control governor controlling an injection amount adjusting mechanism with an electric actuator and enabling to utilize two kinds of governor characteristics suitable for running for works and running on roads. CONSTITUTION:A solenoid 13 being displaced by a stroke proportional to exciting current is connected to a control rack 12 for adjusting a fuel injection amount of an injection pump 11. And a hand accelerator lever 19 retained by friction at a desired operating position in a full running range and a foot accelerator pedal 20 automatically returning to an idling side are provided. And a control mode is automatically changed by a control circuit 18 according to adjustment of the lever 19 so that road running mode can be obtained when acceleration setting by the lever 19 is in a low speed range and working running mode can be obtained when acceleration setting by the lever 19 is in high speed range.

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]

If we classify the governor devices that control the fuel injection pumps of diesel engines according to their temporal patterns, there are two types: all-speed governors, which have a speed-regulating action of 9 degrees in all rotation ranges from idling to maximum rotation, and two types that allow for smooth idling. There is also a minimum/maximum speed governor that exerts a speed regulating function only in the low speed rotation range and high speed rotation range and does not perform the t-Im speed function in the middle rotation range in order to prevent the maximum rotation speed from increasing.

In addition, MfT's all-speed governor is adopted in the agricultural work vehicle mentioned above, which requires stable constant-speed running and constant-speed drive of working equipment regardless of load fluctuations, and smooth acceleration that responds immediately to accelerator adjustment. The latter type of minimum e-maximum speed r governor is suitable for automobiles that require deceleration performance.

[Problem that the invention seeks to solve]

By the way, in recent years, there has been a strong trend toward faster speeds in the above-mentioned transfer work type 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 the V'c agricultural work vehicle is an all-speed governor suitable for the main work in the field, so it is difficult to accelerate and decelerate when driving on the road. The sensation (trivability) was poor.

This invention employs a so-called "1-child! 1tllal governor" in which the injection adjustment mechanism is controlled by an electric actuator, and makes it possible to utilize two types of governor characteristics suitable for work driving and road driving. The main solution to the above problem is to automatically switch the mote.

[Means for resolving conflicts]

In the present invention, the fuel injection 1 adjustment mechanism of the onboard diesel engine is electrically linked to the manually operated accelerator adjustment device via a control circuit. It is configured to be operated by an I actuator, and the engine rotation & f
Torque curve V with small torque fluctuation rate with respect to tlJ
C was set, but the road driving mote ° which controls fuel with Pana characteristics was set, and the torque curve was set to have a large torque fluctuation rate due to changes in engine speed, but Bana characteristics were set to A -1 fl.
L! a hand accelerator lever which is configured to be able to select and switch between the two modes by setting a working driving mode and a working driving mode in one control circuit; A foot accelerator pedal is provided that automatically returns to the low speed side, and when it is detected that the accelerator setting with the hand accelerator lever is at idle or within a low speed range close to this, the foot accelerator pedal automatically returns to the low speed side. When it is detected that the accelerator setting is on the higher speed side than the above-mentioned low range, the control mode is automatically switched according to the adjustment of the hand accelerator lever so that the work driving mode is activated. It has certain characteristics.

[Effect]

In general, work vehicles travel at a constant speed when working, so in order to drive the working device at a constant speed, the hand accelerator lever is operated and maintained at the desired high-speed side chain w:, so this high-speed side accelerator setting is Based on the detection, the governor characteristics are automatically switched to the working mode. Also, when driving on the road, VcVi, in order to perform acceleration and deceleration using the foot accelerator pedal like a general passenger car, the non-end accelerator lever is returned to the eye ring or close to it, so this is detected and the vehicle switches to road driving mode. [Effects of the Invention] Therefore, by simply operating the hand accelerator lever according to the driving mode, the control mode suitable for work driving is automatically set.
A control mode suitable for road and road driving has been created, making it possible to drive with governor characteristics suitable for the driving mode without special mode switching operations. Moreover, this also prevents troubles such as forgetting to change the mode or making a mistake in changing the mode.

〔Example〕

A case in which the present invention is applied to a tractor will be described below.

Diesel engine (2) mounted on the tractor body fil
) is transmitted to the transmission gear 14) via the main clutch hatching (3), where it is serially shifted and connected to the rear wheels, the rear wheels (5) and the rear wheels (5), i5+, and i5+.
At the same time, the working power is branched and transmitted to the rear PTO shaft (7) through a wing PTO transmission system that is independent of the travel transmission system, and a hydraulic tow arm (8) and three-point link mechanism are connected to the rear of the vehicle body. (9) A row of working devices that can be raised and lowered by
It is designed to be driven by the output from the shaft ('?).

The fuel injection pump (injection pump) (Ill) installed in the engine (2) is controlled by a control rack (12)H electronic governor, which is a fuel injection IH amount adjustment mechanism.

That is, the control rack +15 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 detected by a stroke sensor (14) using a differential transformer. In addition, the pump drive camshaft + ts Vc is fixedly installed, and the engine rotation speed is detected by the opposing coil sensor f171 K, and information from these sensors I and αη as well as the accelerator setting that is set separately artificially. The control rack (12) is configured to control the position of the control rack (12) based on the value.

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

This electronic governor uses a hand accelerator lever (Ql) as a manually operated accelerator adjustment device that can be held in any position in the entire range from idling to maximum speed, and automatically returns to the idling side. 7-to-accelerator pegles (1) are used, and each rotary potentiometer I2) outputs the accelerator adjustment position as an analog signal.1. ■It is equipped with.

Further, in this electronic governor Vc, two types of governor characteristics are set in advance by the control circuit.

One of them, as shown in FIG. 3, is set to a torque curve that has a small torque fluctuation rate with respect to changes in engine speed wJ, and is mainly used for road driving. As shown in Figure 4, the torque curve is set to have a large torque fluctuation rate with respect to changes in engine speed lfI, and it is mainly used for work driving, and these two governor characteristics are Automatically selected depending on the adjustment condition of the accelerator lever tool 419,
The following control is performed for each mode.

In the mode using the on-road governor characteristics,
Map control is performed. In other words, the torque curve shown in Fig. 3 has the relationship between the engine speed and the control rank position (torque) stored in advance as map data for each accelerator setting value, and the accelerator setting value obtained from the potentiometer. The map control system determines the target rack position (Pθ) for the detected engine rotation fault based on the map data corresponding to .

Furthermore, 1j PID rotation error control is performed in the mode using the governor characteristics for work traveling.

In this case, the accelerator setting end given by the potentiometer @ means the target rotation speed, and the PID rotation speed control system 1')19 is used to set the target rack position ( P, ), and turn solenoid U PIDIIJI! so that the detected rack position approaches this target rack position (P, ). That's what I do.

In this case, the accelerator setting St by the hand accelerator lever is compared with the reference value from the reference end setter ■, and it is determined whether the accelerator setting is at idling or within a low speed range close to this. l!tJ. Then, when the hand accelerator lever (1!l) is used to set the accelerator, or when the above idling or low speed range is close to this, the target rank from the map control system (Pl) is selected in the selection system @. The position (P,) is selected and given to the PID rack position control system 1, and the selection system -, the target rack position R(P,) from the PID rotation speed system (2) is selected and given to the PID rack position control system.

In other words, when driving on the road with the hand accelerator lever 11j returned to idling or close to it and the foot accelerator pedal (support) being used to increase or decrease the speed, the hand accelerator lever (11j) is switched to the road driving mode using the above map control. During work travel in which the motor is operated and maintained at a suitable high speed side, the work travel mode is switched to the work travel mode using the above-mentioned PID rotation control.

Further, in order to prevent a sudden stop and over-rotation, minimum rack position control and maximum rack position control are also performed. In other words, the nine target rack positions CP selected by the selection system 10,000
, )C(P,) or (P,)) and the lowest rack position (P,) set based on the detected engine rotation song are compared by the discrimination system ■, and the larger one of them is determined as the target rack position (P,
) K is selected to prevent the engine from stopping. Also, as mentioned above, the target rack position (P,) selected in Vc YaJ Separate System ■ and the maximum rack position (P, ) set based on the detected engine rotation & are the second Ya] Separate System ■ are compared, and the smaller one is the final target rank fi
t(P,), so that the engine super run can be stopped at 1111 in advance.

In addition, the rack position control mode in the road driving mode and the work driving mode is not limited to the above-mentioned one, and the rack position control mode in the road driving mode is not limited to the above. It is also possible to use map control for the 11LI type, and use map control for the control mode in the work travel mode with corrections made in accordance with the load. Also, in both modes PIDi
IrlI control or Pl control is also possible.

Also, the solenoid i13 that drives the control rack strike
In place of 1c, a DC electric motor (with a damper size) may be used, and these are collectively referred to as an electric actuator.

Also, Hunt 0 accelerator lever-tllVc! As a means of detecting that the accelerator setting is in the eye ring or a low speed range close to this, the hand accelerator lever
Although it is possible to use a limit switch dedicated to mode switching that acts on the is located at the bottom, and has the advantage that it can be implemented at low cost by adding a simple structure to the control circuit.

[Brief explanation of the drawing]

The drawings show implementation-1 of the governor device for a working vehicle according to the present invention, FIG. 1 is a control block diagram, FIG. 2 is a configuration diagram of the governor device, FIG. 8 is a governor characteristic diagram in road driving mode, and FIG. 4
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, U...Fuel injection amount adjustment mechanism, (13...Electric actuator,
(Lt...Control circuit, α9...Hand accelerator lever-1 ■...Foot accelerator pedal.

Claims (1)

[Claims] Fuel injection amount adjustment mechanism for the installed diesel engine (2) (
12) to a control circuit (
18) electrically linked electric actuator (
13), and a road driving mode in which fuel is controlled using governor characteristics set to a torque curve with a small torque fluctuation rate with respect to engine speed fluctuations;
A control circuit (18) is configured to set a torque curve with a large torque fluctuation rate with respect to engine speed fluctuations, and a work driving mode in which the fuel is controlled using governor characteristics set, so that both modes can be switched and selected; As adjustment tools, a hand accelerator lever (19) that can be held at any operating position and a foot accelerator pedal (20) that automatically returns to the low speed side are provided, so that the accelerator setting with the hand accelerator lever (19) can be set to idling or to idling. If it detects that you are within the nearby low speed range, it will switch to road driving mode.
In addition, when it is detected that the accelerator setting by the hand accelerator lever (19) is higher than the above-mentioned low speed range, the hand accelerator lever (
19) A governor device for a work vehicle configured to automatically switch control modes depending on the adjustment condition of item 19).