JPS60224953A - Fuel injection controller - Google Patents

Abstract

PURPOSE:To improve the injection control accuracy by detecting the maximum no-load rotation or the level near to said maximum rotation then storing the position of a fuel regulation member at that time and correcting the relation between said position and the output from position detecting means. CONSTITUTION:The system will control a linear solenoid 3 to axially displace a control rack 1a integral with the output shaft 3c thus to regulate injection of an injection pump 1. Upon decision that warming has completed and it is under the maximum no-load rotation through the controller 20, the output from a rack position sensor 2 is stored to perform normal control. Then the rotation NE to be detected through a rotation sensor 21 is compared with the rotation N0 which is slightly lower than the maximum no-load rotation, and if NE>N0, control is repeated. With reference to said stored level, the relation between the output from the sensor 2 and the position of rack 1a is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fuel injection amount control device for controlling the position of a fuel adjustment member of a fuel injection pump to a target position.

[Prior art]

In the conventional Bosch PFR type injection pump, as shown in FIG. 1, the injection pump 1 is assembled to the engine separately from the governor, so the injection amount cannot be obtained accurately due to assembly errors. Therefore, after assembly, the injection amount is adjusted using the injection amount adjusting screw 5 or the like while monitoring the output with a dynamometer or the like during engine operation. Therefore, it was time consuming, and it was extremely difficult to make adjustments when repairing the pump after the engine had been installed in the vehicle. In addition, in Figure 1, 5
1 is an engine block, 52 is a camshaft, 3 is a speed control spring, 4 is a start spring, 6 is a governor weight, and 7 is an accelerator lever 11a is a control rack.

Also, as seen in Japanese Patent Application Laid-open No. 56+-75928,
There is a device that attempts to compensate for changes in the injection pump or engine over time by changing the position of the control member during idling, but there is a large difference in the position of the control member at the rated point, which is most needed by the engine, and it is difficult to manufacture the control member. Errors tend to occur due to variations in the number of rotations, and there are also large differences in rotational speed, so variations in characteristics due to differences in the rotational speed of injection pumps, etc. are also likely to occur.

[Purpose of the invention]

The present invention is a fuel injection amount control device for a diesel engine that performs feedback control of the position of a fuel adjustment member of an injection pump to a target position, and detects the no-load maximum rotation speed or a rotation speed near it as a substitute for the above-mentioned rated point. By storing the position of the fuel adjustment member at this time and correcting the relationship between the output of the position detection means and the position of the fuel adjustment member based on this stored value, the governor mechanism can be adjusted more accurately than conventional devices. The purpose is to eliminate assembly errors of the injection pump, eliminate the need for adjustment, and improve the control accuracy of the injection amount.

〔Example〕

The present invention will be explained below with reference to embodiments shown in the drawings.

In FIG. 2, the injection pump 1 is connected to an engine block 51.
It is driven by a camshaft 52 that is fixed to the engine with bolts or the like and rotates in synchronization with engine rotation. A control rack la serving as a known fuel adjustment member for increasing or decreasing the injection amount is attached to the injection pump 1 so as to be slidable in the left-right direction, and is biased leftward by a spring 1b.

The rank position sensor 2 is an operating lance, etc., and the core 2
The output changes depending on the position of a. The glue near solenoid 3 as an actuator is fixed to the engine block 51 so as to be coaxial with the control rack 1a, and the internal iron core 3b and shaft 3C are integrated.
Control rack 1a with spring 3a via d
It is in contact with the left end of the holder and can freely slide left and right. Note that the spring lb is given a sufficiently larger load than the spring 3a, and if no current flows to the linear solenoid 3, the control rack 1a, shirt) 3C
The two iron cores 3b are biased toward the left (in the direction of decreasing the injection amount).

The controller 20 is composed of a microcomputer or the like, receives signals from the rack position sensor 2, rotation speed sensor 21, accelerator sensor 22, water temperature and neutral detection sensors, and sends current to the linear solenoid 3 as an output.

In a general electronic fuel injection amount control device, the rack positions R and w are controlled by the engine rotation speed and the accelerator opening as shown in the first quadrant of FIG. This rank position Rw is 1 as shown by the rank position sensor output VRP and the straight line ■ in the second quadrant.
Although there is a one-to-one relationship, the injection pump 1, linear solenoid 3, and rank position sensor 2 are assembled separately to the engine block 51 as shown in FIG.

It varies as shown in ■. Therefore, the rank position sensor 2 can accurately know only the relative position of the control rack 1a.

Therefore, the controller 20 operates as follows to determine the relationship between the rank position RW and the rank position sensor output VRP. In the flowchart of FIG. 4, in step 1O1, it is determined whether the engine is in a stable warm-up state using a water temperature sensor, etc., and in step 102, it is determined whether there is no load using a clutch switch, a neutral switch, etc. Furthermore, when it is determined in step 103 that the no-load maximum rotation speed is reached, in step 104 the rack position sensor 2
The output VRP (0) is stored, and normal control is performed in step 105. Thereafter, in step 106, the rotational speed NE is compared with the rotational speed N, which is slightly lower than the maximum no-load rotational speed, and when NE>No, the above-mentioned control is performed (repeat).

Here, as mentioned earlier, if the straight lines in Figure 3 vary like ■, ■, ■, respectively, VRP (0) VRP (0
)', VRP (0) ', and the rank position Rw
The relational expressions between VRP and rack position sensor output VRP are calculated as follows. Here, a is a constant.

The rank position at maximum no-load rotation is the value RW(0) at the point N where the no-load rack position curve intersects the rank pattern at 100% acceleration in the first impression of Figure 3, and the rack position and injection The amount is adjusted by the injection pump alone, so it is a nearly constant value.

Therefore, if the rank position is controlled using the above-mentioned tl1 formula, sufficient accuracy can be obtained not only at the rated point but also in the high speed range which is important for engine output. That is, as is obvious in the first quadrant of FIG. 3, the accuracy near the rated point can be improved more than learning the rank position using the idle rotation speed as in the conventional example described above.

In addition, the Bosch PFR type pump and the size type pump explained in this example are mechanically unlikely to change the injection amount due to wear of the cam, etc., and unlike the conventional example described above, the injection amount does not change at the idle speed. There is no need for frequent correction control. In other words, the engine can be controlled to an accurate rank position simply by racing without load after installing the engine in the vehicle or replacing the injection pump. On the other hand, it is possible to eliminate the drawback that the system is easily affected by load fluctuations of the air conditioner, alternator, etc., which is the case when similar control is performed during idle.

Further, the control method of the present invention can be expected to have similar effects with a size-type or distribution-type injection pump in which the injection pump and governor are integrated into the engine.

Furthermore, the present invention can be expected to produce similar effects not only at the maximum no-load rotation speed, but also at high no-load rotation speeds close to the maximum no-load rotation speed.

(Effects of the Invention) As described above, the present invention provides an injection amount control device that performs feedback control of the position of the fuel adjustment member of an injection pump to a target position. Since the position of the fuel adjustment member in the number is memorized and the relationship between the output of the position detection means and the position of the fuel adjustment member is corrected based on this stored value, it is more practical than conventional devices. It is possible to eliminate assembly errors between the governor mechanism and the injection pump in the general range, and to control the injection amount with high precision.As a result, there is no need for adjustment by engine operation, and repairs in the market become easy.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a conventional injection amount control device, and FIG. 2 is an overall configuration diagram of an injection amount control device showing an embodiment of the present invention.
FIG. 3 is a characteristic diagram for explaining the operation of the present invention, and FIG. 4 is a flowchart showing the processing procedure in the controller in FIG. 2. 1... Injection pump, 2... Rank position sensor, 3...
... Linear solenoid, 20 ... Controller, 21
... Rotation speed sensor, 22 ... Accelerator sensor, 51
...Engine block, 52...Camshaft, l
a... Control rank. Representative Patent Attorney Takashi OkabeFigure 2Figure 4

Claims (1)

[Claims] A fuel injection amount control device that feedback-controls the position of a fuel adjustment member of a fuel injection pump to a target position, comprising: a position detection means for detecting the position of the fuel adjustment member; and a correction means for correcting the relationship between the output of the position detection means and the position of the fuel adjustment member based on the stored value. Characteristic fuel injection amount control device.