JPH02125942A - Control device of internal combustion engine - Google Patents

Abstract

PURPOSE:To make easier the control under the condition a constant speed operation and an accelerator operation are repeated, by detecting and storing the engine rotation frequency, and carrying out the fuel control at the necessary time depending on the engine rotation frequency by the accelerator operation, while carrying out the fuel control in the normal condition depending on the engine rotation frequency. CONSTITUTION:An electronic control type fuel injection device A computes an object injection amount of fuel by a control device A1 depending on a rotation frequency detecting device D, an accelerator operation amount detecting device E, and a fuel injection amount detecting device F, of an engine C, and the map of a memory device A2. And depending on the operation result, a fuel injection device B is driven by an actuator A3 to carry out a normal control. In this case, when a memory instruction device G is operated, the engine rotation frequency at that time is stored in a memory device A2, and thereby the object fuel injection amount is computed. And when an accelerator preferential instruction device H is operated, the object fuel injection amount is computed depending on the rotation frequency responding to the accelerator operation.

Description

[Detailed Description of the Invention] Heat (Industrial Application Field) This invention provides a control for an internal combustion engine that allows the user to arbitrarily select between operation at a constant rotational speed and operation at a rotational speed that changes in response to accelerator operation. It is related to the device.

<Conventional technology> A working machine for agricultural work such as a tractor has a work pattern in which it moves straight through the field while performing a certain task while maintaining a constant engine speed from one end to the other, then makes a U-turn, and then performs the same task again. are relatively common. For this reason, in a work machine equipped with an engine equipped with a mechanical governor, for example, a semi-fixed accelerator fixing lever that is fixed by frictional force is installed, and by operating this lever to fix the accelerator position, the engine can be moved straight ahead. It tries to keep the rotation speed constant.

<Problems to be Solved by the Invention> However, with the semi-fixed accelerator fixed lever as described above, the lever may move due to vibrations of the work equipment and change the rotation speed, reducing work efficiency. There is a problem with doing so. Additionally, a link mechanism or the like is required to link the anchor fixing lever to the accelerator, which increases the number of parts and complicates the structure. Also, when making a U-turn in the field, it is necessary to control the rotation speed using the accelerator while performing the U-turn operation, but it is troublesome to switch between constant rotation speed and rotation speed using the accelerator. .

Recently, internal combustion engines that control the amount of fuel injection using an electronically controlled governor with a built-in microcomputer are being installed in working machines. There is no control suitable for tasks such as making a U-turn based on the rotational speed.

The present invention has been made in view of these problems, and aims to provide a control device for an internal combustion engine that can perform the above-described control and provide a working machine with good operability.

〈Means for solving problems〉 In order to achieve the above objectives, this invention.

In a control device for an internal combustion engine equipped with an electronically controlled fuel injection device, priority is given to a storage command means for storing a specific engine rotation speed detected by a rotation speed detection means in a storage means, and a detection signal from an accelerator operation amount detection means. When there is no command from the accelerator priority command means, the rotation speed stored in the memory 1-stage is set as the set rotation speed by the command from the storage command means, and the accelerator priority command means Only when there is a command, the target fuel injection amount is calculated using the rotation speed set by the accelerator operation as the set rotation speed, and the fuel injection device is controlled according to the calculation result.

FIG. 1 is a diagram showing the configuration of the present invention. A is a control means A□, a storage means A2. An electronically controlled fuel injection device comprising a governor section including an actuator A3, etc., and a fuel injection amount [B, C is an engine, D is a rotation speed detection means, E is an accelerator operation amount detection means, and F is a fuel injection amount detection means. These constitute a normal internal combustion engine control device using an electronically controlled governor, and according to the present invention, storage command means G and accelerator priority command means H are further incorporated into the above system.

<Operation> To the control means 〇 determines the set rotation speed and the target fuel injection amount to achieve this from the output signals of each detection means, E and F, and the control map stored in the storage means A2. The normal control operation of operating the fuel injection device B via the actuator A is performed. Then, when the storage command means G is operated, the engine speed detected by the rotation speed detection means 1 at that time is stored in the storage means A2, and from now on, this rotation speed will be used as the set rotation speed. The injection amount is calculated. Also, the accelerator priority command means 11
When is operated, the target fuel injection amount is calculated using the rotation speed corresponding to the accelerator operation detected by the accelerator operation amount detection means E as the set rotation speed only when there is the command.

<Embodiment> An embodiment of the illustrated diesel engine will be described below.

Fig. 2 is a block diagram showing the overall configuration of an embodiment of the present invention, Fig. 3 is a flowchart of the control procedure, and Fig. 4 shows the relationship between the operating state of each switch and the selected set rotation speed. .

In FIG. 2, 1 is an engine, 2 is a fuel injection pump attached to the engine 1, 3 is a rack actuator, 4 is a rotation sensor, 5 is a rack position sensor, 6 is an accelerator position sensor, and 7 is a memory command means. A rotation speed setting switch, 8 a lock/release switch which is an accelerator priority command means, 9 other sensors such as a temperature sensor, 10 a governor characteristic selection switch, and 11 a brake switch.

Reference numeral 15 denotes a control unit using a microcomputer as its main part, which stores an input port 16, an output port 17, a CPU 18 that gives control calculations and input/output instructions, and a control program and various data necessary for control calculations. ROM1
9. It is composed of a RAM 20 and the like used for calculations.

The various sensors and switches mentioned above are connected to the input boat 16, and the rack actuator 3 is connected to the output port 17, and the output signal drives the fuel rack (not shown) of the fuel injection pump 2. It is supposed to be done. Although not shown, an A/D converter or the like may be inserted before the input port 16 as necessary, and a driver circuit may be inserted on the output side of the output port 17 as necessary.

Next, the control procedure will be explained with reference to FIG.

First, in step S1, it is determined whether the rotation speed setting switch 7 is on or off, and if it is on, the process moves to step S2, and the first value of the engine rotation speed detected by the rotation sensor 4 is stored in the RAM 20. . Then, in step S3, fix/
It is determined whether the release switch 8 is on or off, and if it is on, the process moves to step S4, and in step S2, the RAM 2 is
The rotation speed stored as 0 is set as the set rotation speed. On the other hand, if the rotation speed setting switch 7 is off in step Sl, R
No new rotation speed data is stored in AM20, and if there is rotation speed data previously stored in step S2, it is cleared (step S5). Then, in step S6, the accelerator operation amount detected by the accelerator position sensor 6 is input, and the rotation speed based on the accelerator operation is set as the set rotation speed.

Further, if the lock/release switch 8 is off in step S3, the process moves to step S6, where the accelerator operation amount is input, and the rotation speed based on the accelerator operation is set as the set rotation speed.

At this time, the rotational speed data stored in the RAM 20 in step S2 is not cleared and is retained as is.

In the next step S7, the engine speed detected by the rotation sensor 4, the actual fuel injection amount detected by the rack position sensor 5, other operating conditions detected by the sensor 9, etc. are input, and these various information are input. A target injection amount according to the governor characteristic selected by the characteristic selection switch 10 is calculated using the data and the set rotation speed selected in step S4 or S6 described above. Then, the drive amount of the rack actuator 3 necessary to eliminate the error with the target injection amount is calculated, and the result is output to drive the rack of the fuel injection pump 2 and inject a predetermined amount of fuel. .

In this way, the content of the control varies depending on the combination of on and off of the rotation speed setting switch 7 and the lock/release switch 8.
You can choose the street. That is, when the rotation speed setting switch 7 is turned on, the rotation speed at that time is stored, and when the lock/release switch 8 is turned on, the engine is operated at the stored rotation speed.

Further, when the fixing/release switch 8 is turned off, the engine is operated at the rotational speed based on the accelerator operation for that period, and when the switch 8 is turned on again, the operation returns to the stored rotational speed. Also, if the rotation speed setting switch 7 is off,
The engine is always operated at the rotation speed based on the accelerator operation. FIG. 4 is a table showing the relationship between the operation state of each switch, such as one or more, and the selected set rotation speed.

Therefore, for example, in the above-mentioned working machine, if the rotation speed setting switch 7 is turned on when the desired rotation speed suitable for straight-line work is obtained, constant speed operation at that rotation speed can be performed from then on. After making a U-turn while controlling the rotation speed to an appropriate speed using the accelerator by turning off the lock/M release switch 8, it is possible to return to constant speed operation at the same speed as before, improving the operability of the work equipment. be done.

Although it is not shown in the flowchart of Fig. 3, when the brake is operated, it is detected that the brake switch 11 is turned on, and the constant speed operation at the memorized rotation speed is temporarily interrupted and the speed is reduced or reduced. It is possible to stop.

<Effects of the Invention> As is clear from the above description, the present invention provides a control device for an internal combustion engine equipped with an electronically controlled fuel injection device.
A specific engine rotation speed detected by the rotation speed detection means is memorized and constant speed operation is performed at this rotation speed, and by operation of the accelerator priority command means, the engine can be operated at a rotation speed corresponding to the accelerator operation. This is how it was done.

Therefore, suitable control can be easily performed when constant speed driving and driving by accelerator operation are repeated.
The workability of agricultural working machines such as tractors, which are used relatively often in this way, is improved. Also, when installing a lever that mechanically fixes the accelerator, the lever moves and the rotation speed changes,
This eliminates the problems of an increased number of parts and a complicated structure, making it possible to obtain a work machine that is easy to operate and use at a low cost.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the configuration of the present invention, Fig. 2 is a block diagram showing the overall configuration of an embodiment of the invention, Fig. 3 is a flowchart of the control procedure 1, and Fig. 4 is the operating state of each switch. It is a diagram showing the relationship between the set rotation speed and the selected rotation speed. DESCRIPTION OF SYMBOLS 1... Engine, 2... Fuel injection pump, 3... Rack actuator, 4... Rotation sensor, 5... Rack position sensor, 6... Accelerator position sensor, 7...
Rotation speed setting switch (memory command means), 8...Fixed/
Release switch (accelerator priority command means), 15-control unit, 18-CPU, 20-=RAM. Patent applicant Yanmar Diesel Co., Ltd. Agent
Patent Attorney Shino 1) Actual diagram Figure 4

Claims (1)

[Claims] (1) In a control device for an internal combustion engine equipped with an electronically controlled fuel injection device, the storage command means stores a specific engine rotation speed detected by the rotation speed detection means in the storage means, and the accelerator operation amount detection means detects the engine speed. an accelerator priority command means for instructing to give priority to the signal; and when there is no command from the accelerator priority command means, the rotation speed stored in the storage means by the command from the storage command means is set as the set rotation speed, and the accelerator priority command means an internal combustion engine, comprising: control means for controlling a fuel injection device by calculating a target fuel injection amount using a rotation speed set by an accelerator operation as a set rotation speed only when a command is given; control device.