JPS60169633A - Measuring method for fuel consumption amount of diesel engine - Google Patents

Abstract

PURPOSE:To reduce a cost, by a method wherein an injection amount decided at each injection timing from the starting of a diesel engine is integrated to determine a fuel consumption amount. CONSTITUTION:When a step 300 is started by means of a pulse signal from a sensor for the number of revolutions of an engine, the number of revolutions of an engine is calculated at a step 302, and it is decided at a step 304 whether it comes to a timing to set an injection time. If it is decided that it came to such timing, the injection time is set in a step 306 from an injection amount QFIN determined from the number of revolutions of the engine and the opening of an accel, and in a step 308, a current injection amount QFIN is added to an integrated amount QS of injection amounts between the starting and the preceding injection to make a consumption amount. This eliminates the need to attache a flow rate sensor to a fuel system flow passage, resulting in the possibility to reduce a cost.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for measuring fuel consumption of a diesel engine that electronically controls the amount of fuel injection.

[Background of the invention]

As a conventional means for measuring the fuel consumption of this type of diesel engine, a method has been proposed in which a flow sensor is disposed in the fuel system passage of the diesel engine and the fuel consumption is calculated from the detected output of the flow sensor.

However, when employing the above method, fuel leakage in the fuel passages etc. causes measurement errors, so it is necessary to take countermeasures against this, resulting in a drawback of high costs.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for measuring fuel consumption of a diesel engine that reduces costs.

[Summary of the invention]

The present invention takes in the detection outputs of various sensors that detect the operating state of a diesel engine, calculates the fuel injection amount based on these detection outputs, and injects fuel at a predetermined timing. The fuel injection amount determined for each injection timing is integrated from
It is characterized in that the integrated value is used as the fuel consumption amount.

[Embodiments of the invention]

Embodiments of the present invention will be described based on the drawings.

FIG. 1 shows the configuration of a fuel injection pump for a diesel engine to which the present invention is applied.

The fuel injection pump 1 has a drive/gift 2 and is connected via this shaft 2 to an internal combustion engine (not shown). A vane pump 4, a pulser 6, and a coupling 8 are attached to the shaft 2.

The coupling 8 is connected to a plunger 12 to which a cam play (10) is integrally connected. The end of the plunger 12 is fitted into the boss 11.

The coupling 8 integrally rotates the plunger 12 and is cut out so that the plunger 12 can reciprocate in the axial direction. Plunger 12 and cam plate 10 are always biased to the left by spring 13.

A roller ring 14 that surrounds the coupling 8 and is rotatable coaxially with the drive shaft 2 is attached. A cam roller 16 is attached to the right side wall of the roller ring 14 so as to face the cam plate 10 along the circumference around the rotational axis of the roller ring 14 .

The roller ring 14 is rotated by a predetermined angle by a timer 18. That is, the roller ring 14 is connected to the piston pin 2.
0, and the piston pin 20 is connected to the timer piston 22.
It is connected with O. A spring 26 is interposed between one side of the timer piston 22 and the housing 24, and the other side is configured so that the discharge pressure of the vane pump 4 acts on the timer piston 22. It reciprocates accordingly, thereby controlling the timing of the start of injection.

A block 28 into which the boss 11 is fitted is attached to the pump housing 24, and a fuel passage 32 communicating with a fuel chamber 30, which is the low pressure side within the housing 24, is bored in the block 28. A solenoid valve 34 for fuel cutoff is attached to the fuel passage 32, and the fuel passage 32 can be opened and closed by the valve body 36. Furthermore, a solenoid valve 38 for fuel overflow is attached to the block 28, and a high pressure chamber 40 is defined between the solenoid valve 38, the plunger 12, and the boss 11.

The high pressure chamber 40 is entered through fuel introduction notches 42 formed on the circumferential surface of the plunger 12 and corresponding to the number of cylinders.

It can communicate with a fuel introduction passage 44 between the solenoid valve 34 and the high pressure chamber 40 . Return passage 46 of solenoid valve 38 for fuel overflow
is in communication with a fuel introduction passage 44 formed between the solenoid valve 34 and the high pressure chamber 40 via a communication passage 45 in the boss 11 . Furthermore, the delivery pulp 4 is placed in the block 28.
8 is attached, and can communicate with the high pressure chamber 40 via a fuel supply passage 50 and fuel supply notches 52 formed on the circumferential surface of the granger 12 corresponding to the number of cylinders.

In addition, 54 is a fuel supply port, 56 is a fuel return port, 58 is a pressure regulating valve that regulates the discharge pressure of the vane pump 4, and 60 is a magnetic pickup, which is arranged opposite to the balsa 6, and which meets the standards for controlling the opening and closing of the solenoid valve 38. Detect position signals.

Further, in FIG. 1, 62 is a central processing unit (C'PU
), a read-only memory (ROM), a random access memory (RAM), etc., in which programs to be described later and programs regarding the injection amount are written in advance, and are obtained from, for example, a sensor (not shown). Signals relating to the accelerator opening degree and engine speed, and reference position signals from the pips and quasops 6o are input, and the injection amount and other controls are performed based on these signals.

Details of the solenoid valve 38 for fuel overflow are shown in FIG.

The solenoid valve 38 has a valve main body 103 in which a return passage 46 for the solenoid valve 38 is bored. It has an iron core 107 around which a coil 105 is wound. A cylinder 111 is fitted into a large diameter chamber 109 formed in the valve body 103, and a first piston 113 is fitted into the cylinder 111. The outer periphery of the cylinder 111 on the high pressure chamber side is a small diameter portion, and a return chamber 115 is defined between the inner circumferential surface of the large diameter chamber 109 and the small diameter portion, and the return chamber 115 communicates with the return passage 46. There is.

On the other hand, the inner circumference of the cylinder 111 on the high pressure chamber side is a large diameter portion, and a pressure receiving chamber 117 is defined between the circumferential surface of the first piston 113 and the large diameter portion. Internal chamber 1 of first piston 113
A valve seat 121 is loosely fitted into the valve 19 , and a spring 127 is interposed between the flange 123 of the valve seat 121 and the bottom 125 of the first piston 113 . and the first piston 113
A hole 129 communicating with the high pressure chamber 40 is bored in the bottom 125 of the pressure chamber 40 . A needle valve 131 is disposed inside the valve seat 121, and the needle valve 131 is attached to a moving member 133 by caulking. The needle valve 131 is normally urged toward the high pressure chamber by a spring 135 and comes into contact with the valve seat 121, thereby closing the hole 138 of the valve seat 121 (7) and sealing the high pressure chamber 40.

The axial positions of the cylinder 111 and the first piston 113 are such that on the high pressure chamber side, through holes 139 and 141 are formed in the center of the washer 14, which is fitted into the valve body 103, respectively.
3,145.

The return passage side is defined by the flange 123 of the valve seat 121.

5 coil 105 is energized and the needle valve 131 is displaced from the position shown in FIG.
8 is opened, and a relatively small amount of high pressure fuel in the high pressure chamber 40 flows into the return passage 46. At this time, the first piston 113 is lifted to the right due to the pressure difference before and after the bottom portion 125 of the first piston 113.

The lift of the first piston 113 causes high pressure fuel to flow into the pressure receiving chamber 1.
17 , which causes a relatively large amount of fuel to flow out of the return chamber 115 into the return passage 46 .

Note that in the normally closed solenoid valve 38 as shown in this embodiment,
When the ignition switch is turned off, the fuel overflow solenoid valve 38 is not opened, so the fuel supply to the nozzle is not immediately stopped, and the internal combustion engine becomes difficult to stop.
According to the procedure shown in the figure, electricity is applied for a predetermined time after the ignition switch is turned on, and the entire amount of room-pressure fuel in the high-pressure chamber 40 is released to the return passage 46 via the solenoid valve 38.

Referring to FIG. 3, when the ignition switch is turned off, this program is started, and in step S1, the timer starts the timer operation, and the solenoid valve 38 is energized. Then, in step S2, it is determined whether the timer has measured a predetermined time, and if an affirmative determination is made, the process proceeds to step S3 and the energization to the solenoid valve 38 is stopped. For example, the timer is set to 10 seconds.

The operation of the fuel injection pump 1 shown in FIGS. 1 and 2 will now be described.

When the drive shaft 2 is driven in synchronization with an internal combustion engine (not shown), the vane pump 4 is driven, and the fuel whose pressure is regulated by the pressure regulating valve 58 is pumped into the fuel chamber 30° fuel passage 32.44.
and is guided to the pressure chamber 19 of the timer piston 18. On the other hand, the plunger 1 is synchronized with the drive of the drive shaft 2.
2 and the cam plate 10 rotate, the process in which the protrusion 10B of the cam plate 10 rides on the roller 16 is the compression stroke of the plunger 12, and the process in which the protrusion 10a is removed from the roller 16 is the suction stroke of the plunger 12.

During the suction stroke of the plunger 12, the solenoid valve 3 for fuel cutoff
4 is energized and the valve body 36 opens the fuel passage 32, fuel is introduced into the high pressure chamber 40 via the fuel passage 32, 44 and the notch 42.

During the compression stroke of the plunger 12, the solenoid valve 3 for fuel overflow
8 is deenergized and the needle valve 131 closes the hole 138, the pressure of the fuel is increased in the high pressure chamber 40, and the notch 52
The high pressure fuel then reaches the delivery valve 48 via the fuel supply passage 50.

A nozzle (not shown) of each cylinder via a delivery valve 48
guided by. The solenoid valve 38 is energized and the needle valve 131
When the high pressure chamber 40 is lifted to the right, the high pressure chamber 40 communicates with the return passage 46 on the low pressure side, as described in detail in the explanation of FIG.
With this, fuel supply to each nozzle can be stopped.

Next, FIG. 4 shows the contents of the main program executed by the control circuit 62. In the figure, when the main program is successfully started at step 200.

In the next step 202, the engine speed is acquired, and in step 204, the accelerator opening degree is acquired. Furthermore, in step 206, the fuel injection amount QFIN f is calculated based on the engine speed and accelerator opening obtained in steps 202 and 204, and the process proceeds to step 208.

In step 208, it is determined whether or not time periodic processing is to be performed. If it is determined in step 208 that the ant is NO#, the process jumps to step 216, and the execution of the main program is ended.

On the other hand, if it is determined in step 208 that *Y 6 SII, the process moves to step 210, where various A/D conversion processes are performed. In the next step 212, fuel injection timing control is performed, and in step 214, failure diagnosis of each part of the engine is performed, and then in step 21
Step 6 ends the execution of the main program.

Next, FIG. 5 shows the contents of a fuel consumption calculation routine that is activated by a pulse signal (not shown) output from an engine rotation speed sensor (not shown) for detecting the engine rotation speed. In the same figure, when this routine is started in step 300, the engine speed is calculated in step 302, and then in step 304, it is determined whether or not the timing to set the fuel injection time has come, in other words, the reference position is determined from the electromagnetic pickup 60. A determination is made as to whether or not the signal has been output.

If it is determined in step 304 that the timing to set the fuel injection time has not yet arrived - 411, step 312
to end execution of this routine.

On the other hand, if it is determined in step 304 that the timing to set the fuel injection time has come, the next step 306 is performed.
Then, set the fuel injection time from the fuel injection amount QpxN obtained in step 206 of the main program shown in FIG.
Furthermore, in step 308, the current fuel injection amount Q FIN is added to the cumulative value Qs of the fuel injection amount from the time of startup to the previous time, and
The process moves to step 310.

In step 310, a determination is made that the engine stalls, and in step 3
At step 12, execution of this routine ends.

In this way, in this embodiment, the amount of fuel consumed can be measured by calculation processing using software without providing a flow rate sensor in the fuel system passage of the diesel engine, so that costs can be reduced compared to the conventional method.

In addition, since the fuel injection amount can be calculated for each fuel injection timing, the instantaneous fuel consumption, average fuel consumption, and even remaining fuel amount can be divided by the signal from the vehicle speed sensor to calculate the amount per mileage. You can also easily set the fuel consumption rate and display these on the display.

〔Effect of the invention〕

Fuel consumption can be measured through calculation processing using software without providing a flow sensor in the fuel system passage of a diesel engine.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the configuration of a fuel injection pump for a diesel engine to which the present invention is applied, Fig. 2 is an enlarged view showing details of the solenoid valve for fuel overflow, and Fig. 3 is the same as Fig. 2. A flowchart showing an example of a procedure for opening the shown solenoid valve for a predetermined period after the ignition is turned off, FIG. 4 is a flowchart showing the contents of the main program executed by the control circuit 62, and FIG. 5 is the contents of the fuel consumption calculation routine. It is a flowchart which shows. 1...Fuel injection Honda, 2...Driven Yaft. 4...B/Pump, 10...Cam plate. 12゛°・Plunger, 16...Cam roller, 18・
・Timer, 30... Fuel chamber (low pressure side), 32... Fuel passage, 34... Solenoid valve for fuel cutoff, 36... Valve body, 38... Solenoid valve for fuel overflow, 40...・Hyperbaric chamber,
44... Fuel introduction passage, 46... Return passage. 62...Control circuit. Agent Tatsuyuki Unuma (and 1 other person) Figure 4 Figure 5 Procedural amendment (method) % formula % 1. Indication of the case 1982 Patent application No. 24724 2. Name of the invention Fuel consumption of diesel engine Measurement method 3 Relationship with the case of the person making the amendment Patent applicant name (320) ) Yota Motor Co., Ltd. (and 1 other person) 4. Voluntary action by the agent 7. Drawings to be amended 8. Details of the amendment Fig. 2 Please correct the attached sheet. Figure 2 1

Claims (1)

[Claims] The detection outputs of various sensors that detect the operating status of the diesel engine are captured, the fuel injection amount is calculated based on these detection outputs, and fuel injection is performed at predetermined timings. 1. A method for measuring fuel consumption of a diesel engine, characterized by integrating the fuel injection amount determined for each time, and using the integrated value as the fuel consumption.