JPS59192842A - Distributor type fuel injection pump for diesel engine - Google Patents

Abstract

PURPOSE:To control fuel injection correctly by determining the timing for starting fuel injection and the timing for terminating fuel injection on the basis of the crank angle detected by a crank angle detector. CONSTITUTION:A controller 90 detects the timing for starting fuel injection on the basis of the outputs of a crank angle detector 74 and a position sensor 76. An aimed value for executing feedback control of the injection starting timing is varied according to the output signal of the crank angle sensor 74 and operational conditions of an engine detected from an accelerator sensor 68, a sensor 70 for detecting the temperature of intake air and a sensor 72 for detecting the water temperature. Further, the controller 90 determines the injection terminating timing according to the output of the accelerator sensor 68, and the sensors 70, 72. With such an arrangement, it is enabled to control fuel injection correctly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel injection pump for a diesel engine, and more particularly to a distribution type fuel injection pump.

This type of fuel injection pump is configured so that a single plunger rotates while distributing fuel to each cylinder of the engine, and is smaller and lighter than the generally used size fuel injection pump. It is possible to achieve this.

However, in the conventional fuel injection pump of this scale, the fuel injection amount was mechanically controlled, so there was a problem that there was a low degree of freedom in providing the optimal fuel injection characteristics for the various operating conditions of the engine. there were.

The present invention has been made in view of the above-mentioned conventional problems,
The purpose is to provide a distribution type fuel injection pump that can select arbitrary fuel injection characteristics in accordance with the operating conditions of a diesel engine.

In order to achieve the above object, the present invention provides a pump mechanism that distributes and pressure-feeds fuel to each injector, a state detection system that detects state quantities related to the engine, and a control system that controls the pump mechanism according to the detected engine state quantities. The state quantity detection system includes a crank angle detector that detects the crank angle, and the control system detects the fuel 1' based on the detected crank angle.
The fuel injection amount is controlled by determining the iK injection start time and also determining the time to release the fuel being pumped to the low pressure side, that is, the injection end time.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a distribution type fuel injection pump according to the present invention will be described below based on the drawings.

The pump mechanism 10 that distributes and pressure-feeds fuel to each injector is constructed as follows in FIG.

A feed pump 12 is connected to a drive shaft 11 driven by a diesel engine. Cam plate 14. Plunger 16 is being driven at the same time.

The feed pump 12 is connected to a fuel tank via a fuel filter water separator, and can suck up fuel from the tank via a suction pipe 18 and feed it into the low pressure chamber 20.

In this embodiment, a vane type feed pump 12 is used. Therefore, when the rotor is rotationally driven by the drive shaft 11, the blades loosely inserted in the rotor are applied to the inner wall of the pressure chamber by centrifugal force. At this time, the center of the rotor is at a distance of 1 (saltpeter) from the center of the pressure chamber, so the fuel between the blades is moved and pumped into the low pressure chamber 2o.

On the other hand, cam plate 14. The plunger 16 is integrated and is rotationally driven by the feed pump 11 via a coupling 22.

The coupling 22 supports the cam plate 14 and the plunger 16 so as to be slidable in the left and right directions in the figure, so that the plunger 16 can move in the left and right directions in the figure while rotating.

A cylinder 26 is press-fitted into the pump body 24, and the plunger 16 is fitted into the cylinder 26. Therefore, the plunger 16 can reciprocate in the left and right directions in the figure while rotating within the cylinder 26.

Here, the wavy cam face of the cam plate 14 is pressed against a roller 28 supported within the pump body 24 by a spring 3o.

Therefore, when the cam plate 14 is rotated pj4 lI:JJ by the drive shaft 11, the plunger 16 can drive the piston while rotating in the left-right direction in the figure according to the shape of the cam face of the cam plate 14.

The high pressure chamber 32 at the tip of the plunger 16 and the low pressure chamber 20 are communicated through a suction passage 4, and the low pressure chamber 2
The fuel in the high pressure chamber 32 is guided through the suction passage 34 and into the suction group 36 . The number of suction groups 36 corresponding to the number of cylinders of the engine is formed on the side surface of the tip of the plunger 16, so that the solvent is intermittently supplied into the high pressure chamber 32 from the suction passage 34.

In addition, there is a feed hole 38 in the tip of the plunger 16.
A distribution boat 40 is formed in the middle side of the plunger 16 and communicates with the feed hole 38 .

A distribution passage 44 connected to the injector of each cylinder of the diesel engine (not shown in FIG. 1) via a union 42 is formed so as to surround the position where the distribution boat 40 of the plunger 16 is formed.

With the above configuration, when the plunger 16 rotates and moves to the left, the suction passage 34 and the suction group 36 meet and the fuel in the low pressure chamber 20 is sucked into the high pressure chamber 32, and then the plunger 16 When the is rotated one more time, the suction group 36 is closed and the distribution boat 40 is opened to one distribution passage 44. When the plunger 16 is subsequently rotated, the cam plate 14 is NUFE'd by the roller 28, the plunger 16 moves to the right, and fuel is force-fed to the injector through the distribution passage 44.

Of the fuel supplied to the low pressure chamber 20 by the feed pump 12, surplus fuel other than the amount of fuel required for injection is returned from the low pressure chamber to the fuel tank via a return pipe 46 via a relief knob (not shown). There is.

Further, a fuel cut-on lens 48 for opening and closing the suction passage 34 is provided. The fuel cut solenoid 48 is driven according to the operation of the ignition switch, and when the ignition switch is in the off position 1;
When the ignition switch is operated to close the suction passage 34, and when the ignition switch is operated to the starter position or to its ignition position, the suction passage 34 is opened.

As described above, the pump mechanism 10 of this embodiment is configured to be able to distribute and pressure feed fuel to each injector.

"The pump machine NJto of this embodiment is also equipped with a timer machine 4'i4 that includes a timer piston 50 and can adjust the advance or delay of the fuel injection start timing as described below.

In FIGS. 1 and 2, the roller 28 is rotatably attached to the support arm 52.
The upper tip of the pump body 241 is connected to the roller ring 54.
The other lower end is fixed to the slide shaft 56 at the second arm.

The slide shaft 56 is rotatably fitted into a timer piston 50 that is movable in the left and right directions in FIG.

The timer piston 50 is biased by a spring 58 in the direction of injection delay (leftward in FIG. 2).

The fuel injection start timing is determined by cam play) 14 and roller 28.
At this time, when the timer piston 50 is moved in the left-right direction in FIG. .

In addition, the sky 1i3j G 2 provided with the spring 58 is JI
It communicates with the suction side of the feed pump 12 via an I circuit 64, and the space 60 and the space 620 communicate with each other via an orifice 63.

Furthermore, the space 60 communicates with the pump internal low pressure chamber 20 through a passage with a pressure regulating valve 66 interposed therebetween, and the fuel pressure within the space 60 is adjusted by controlling the opening/closing time ratio of the pressure regulating valve 66. The position of the timer piston is determined by the balance between the spring 58 which tends to move the timer piston to the left and the fuel pressure within the space 60 which tends to move the timer piston to the right. from,
By controlling the opening/closing time ratio of the pressure regulating valve 66, the timer piston position is controlled, and therefore, the fuel injection start timing is controlled. As described above, the pump mechanism 10 of this embodiment includes the timer piston 50, and is equipped with a timer mechanism capable of vertically adjusting the advance/delay of the fuel injection start timing.

Furthermore, in this embodiment, as shown below, the number of states related to the diesel engine is detected by the state quantity detection system, and the pump unit 10 of 211Σ is controlled according to the detected engine state quantities. It is controlled by a thread.

In the third case, the state '-11 detection system of this actual field example is the accelerator sensor 68. Intake temperature sensor 70. water temperature sensor 72,
and a crank angle detector 74. It has a timer piston position detector 76.

In the Fujimanzan example, the dual crank angle detector 74 consists of a rotation angle detector that detects the rotation angle of the drive shaft 11,
For this reason, the rotation angle (the roaster is constructed as shown in FIG. 4).

That is, in FIG. 4, a disc-shaped rotor 78 that is rotationally driven by a drive shaft 11 is provided on the low-pressure chamber 20 side, and magnets 80 are provided at predetermined intervals around the circumference of the rotor 78. A pickup 82 for detecting the passage of each magnet 80 is attached with =b on the pump body 24, and its output signal is used as the detection signal of this detector.

Further, the position detector 76 is constructed as follows in FIG.

In FIG. 2, a plunger 84 is provided, one end of which is fixed to the E side of the timer piston 50 and the other end of which protrudes from the side wall of the pump main shaft 240. The left end of the plunger 84 moves as shown in FIG. The amount of movement corresponds to the adjustment of the fuel injection start timing.

A cover 86 is attached to the left end protrusion τ11 of the plunger 84.
A sliding resistor 88 is fixed inside the bag 86. The sliding terminal of this sliding resistor 88 is moved once by the side tip Z1.1 of the plunger 84, and therefore its iJ'z 1') shi'! L! Or its output voltage is ・jυl at the start of fuel injection ;) I M
Zhou! It has a point corresponding to the amount of If.

This detection output of the sliding resistor 88 is used as the detection output of the standard i4 detector 76.

On the other hand, the control system of this embodiment has a controller 90, a spill solenoid 92, and a pressure regulating valve 66 in the third section 1v.

The above controller 90 is an AD converter 94, Cl)
U 96 , a programmable counter 98, and the programmable counter 98 is a free running timer 1.
00, an output capture register 102, an input capture register 104X an output capture register 106.

The detection outputs of the accelerator sensor 68, intake ♂1 sensor 70, water temperature sensor 72, and position detector 76 are converted into digital signals by an AI converter 94 and sent to the CPU 9.
(The crank angle detector 74,
The detection signal is supplied to the CPU 96 via the input capture register 104. And CPU96
The control output is output to the pressure regulating valve 66 and spill solenoid 92 via output cap registers 102 and 106, respectively.

The controller 90 includes a crank angle detector 74 and a position:
The fuel injection start timing is detected based on the detection output of the accelerator sensor 68 . Intake temperature sensor 70. An opening/closing signal is sent to the pressure regulating valve 66 to obtain the desired injection start timing calculated from engine operating conditions from the water temperature sensor 72 and engine rotational speed information obtained from the signal from the crank angle detector 74. By outputting the signal, it is possible to adjust the advance or delay of the fuel injection start timing by the timer mechanism.

The controller 90 has an accelerator sensor 68 degrees and an intake air temperature sensor 70 degrees. The fuel injection demand can be calculated based on each detection output of the water temperature sensor 72, the fuel injection end time can be determined accordingly, and the control output can be outputted to the spill solenoid 92 via the output capture register 106 at the end time. . .

The spill solenoid 92 can open and close a fuel passage 108 that communicates the low pressure chamber 20 and the high pressure chamber 32, as shown in FIG. Open the low pressure chamber 20 and high pressure chamber 32
It is possible to terminate the fuel injection by communicating with the high pressure chamber 32 and thereby lowering the fuel pressure in the high pressure chamber 32.

A preferred embodiment of the distribution type fuel injection pump according to the present invention has the above configuration, and its operation will be explained below. Note that FIG. 6 shows waveforms at various parts.

When the ignition switch is operated, the pump starts operating and the fuel cut solenoid 48 opens the suction passage 34.

Then, the controller 90 determines the fuel injection start timing through the above operation, and when the diesel engine is boosted, engine fuel is injected from the pump mechanism 10 via the injector.

At this time, the controller 90 calculates the fuel injection amount based on the detection outputs of the accelerator sensor 68, intake air temperature sensor 70, and water temperature sensor 72, determines the fuel injection end time based on this, and sends the control output to the spill solenoid at the end time. 92
By outputting to , the spill solenoid 92 opens the fuel passage 108 and stops fuel injection.

When the diesel engine is operating in this way, the position of the timer piston 50 is controlled by controlling the pressure regulating valve 66 according to the engine speed, and the advance or delay of the fuel injection start timing is adjusted. It is done. The amount of adjustment is detected by the position detector 76, and the controller 90 performs feedback control of the fuel injection start timing based on the detected output.

Furthermore, the controller 90 can detect the output state required of the easel engine based on the detection output of the accelerator sensor 68, and in addition, the controller 90 can detect the output state required of the easel engine. The fuel injection amount is determined by taking into account fine corrections based on the detection output of the water temperature sensor 72.

Further, the controller 90 outputs a control signal to the spill solenoid 92 at an appropriate position where the plunger 16 is in the suction stroke to close the fuel passage 108 and prepare for the next pumping stroke.

Furthermore, when changing the fuel injection start timing according to the advance/delay adjustment amount by the timer mechanism, the controller 90 performs control by taking into account the time required to execute the fuel injection.

The controller 90 monitors the engine speed based on the detection output of the crank angle detector 74.

As explained above, according to this embodiment, the amount of injected fuel can be accurately controlled according to the operating state of the engine, so that an arbitrary torque can be set using the detection signal of the accelerator sensor 68 as a parameter as shown in FIG. The torque characteristics at full throttle can be precisely matched to the smoke limit of the engine.

In addition, since the fuel injection amount for all cylinders can be controlled with one spill solenoid 92 even in a multi-cylinder engine, the configuration of the pump mechanism 10 is simple, compact, and lightweight, and the fuel injection amount for each cylinder can be controlled. Compared to the case where the injection amount is controlled, there is no error in the fuel injection amount between air and oil, and the control circuit can also be simplified.

Next, another preferred embodiment of the distribution type fuel injection pump according to the present invention will be described using FIGS. 8 to 1z.

In FIG. 8, a relative rotation angle detector 110 is composed of a pickup 82 attached to a roller ring 54 and a rotor 78 driven by a drive shaft 11.

Note that in this embodiment, the magnet 80 is not used, and instead a protrusion 112 is formed on the rotor 78, and the pickup 82 detects the presence or absence of the protrusion 112.

Since this relative rotation angle detector 110 can detect the relative rotation angle between the ring 54 and the drive shirt 11, it is necessary to calculate the injection start from two types of 1g numbers: the crank angle 1g and the timer piston position signal. First, relative rotation angle detection 11
It is possible to know the start of injection just by looking at the 0 signal.

FIG. 9 shows the installation state of the relative rotation angle detection unit 13s110, and the same reference numerals are given to the same parts as those described above, and the explanation thereof will be omitted.

FIG. 10 shows the configuration of the legal profession amount detection system and control system in this embodiment, and the output of the relative rotation angle detector 110 is transmitted to the waveform shaping circuit 114 provided in the controller 90.
The signal is supplied to the input capture register 104 via the input capture register 104.

Since the pump of this embodiment is configured as described above, the pump of this embodiment can operate in the same manner as the previous embodiment.

Fig. 11 shows the signal waveforms of each part when the advance/delay adjustment of the fuel injection start timing is not performed, and Fig. 12 shows the signal waveforms of each part when the adjustment is made. 9 and π represent the fuel injection period, and when the adjustment is performed in FIG.
02゜204.206,208 is 300.302,30
4°306.308 (for example, by 10 degrees).

As explained above, according to the present invention, since the fuel injection amount is controlled accurately in a timing manner, the characteristics of the engine speed relative to the engine speed can be arbitrarily set according to the intended use of the engine.

Therefore, the drivability of the vehicle can be improved by freely controlling the fuel injection amount not only during steady operation but also during acceleration and deceleration, and especially for vehicles with automatic transmissions, the shift shock can be increased.
l! It becomes possible to plan a ¥ castle.

However, it is still possible to improve the exhaust characteristics and increase the engine output by precisely matching the fuel injection amount to the engine's smoke limit.

Furthermore, since the fuel injection amount can be freely controlled during startup and warm-up, it is also possible to improve the startability and warm-up characteristics of the engine.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of the pump mechanism in the first embodiment,
Fig. 2 is an explanatory diagram of the configuration of the timer mechanism in the first embodiment, Fig. 3 is an explanatory diagram of the configuration of the state quantity detection system and control system in the first embodiment, and Fig. 4 is the crank angle detector in Fig. 3. Figure 5 is an explanatory diagram of the configuration of the spill solenoid in Figure 3, Figure 6 is the configuration of the spill solenoid in the first embodiment.
J operation f: Waveform to be explained L21゜ Fig. 7 is a torque characteristic diagram of the first embodiment, Fig. 8 is an explanatory diagram of the configuration of the relative rotation detector in the second embodiment, and Fig. 9 is a relative rotation diagram in Fig. 8. The mounting of the rotation angle detector is explained in the state diagram, FIG. 10 is a diagram explaining the configuration of the state quantity detection system and control system in the second embodiment, and FIGS. 11 and 12 are diagrams explaining the operation of the second embodiment. FIG. 10... Pump + MtA, tt... Drive shaft. 14...Cam plate, 16...Plunger. 20...Low pressure chamber, 22...Coupling. 26...Cylinder, 28...Roller. 32... Hyperbaric chamber, 40... Distribution boat. 50...Timer piston, 54...Roller
') nk. 68...Accelerator sensor, 70...Intake temperature sensor. 72...Water temperature sensor, 74...Crank angle detector. 76...Timer piston position detector. 78...Rotor, 80...Magnet. 82...Pickup. 84...Timer piston plunger. 88...Sliding resistor, 90...Controller. 92... Spill solenoid, 108... Fuel passage. 110...Relative rotation angle detector, 112...Protrusion. Agent Tatsuyuki Unuma (and 1 other person) Figure 6 TDC Japan DCTDC Figure 7 Figure 8 Figure 2

Claims (6)

[Claims] (1) It has a pump mechanism that distributes and pressure-feeds fuel to each injector, a state quantity detection system that detects state quantities related to the engine, and a control system that controls the pump mechanism according to the detected engine state quantities. Distributed fuel for a diesel engine, wherein the detection system includes a crank angle detector that detects a crank angle, and the control system determines fuel injection start timing and fuel injection end timing based on the detected crank angle. injection pump. (2) The fuel injection mechanism includes a timer mechanism capable of adjusting the advance or retardation of the fuel injection start timing, the state quantity detection system includes an injection timing adjustment amount detector that detects the amount of advance or retardation adjustment of the start timing, and the control system The distributed fuel injection pump for a diesel engine according to claim 1, wherein the fuel injection start timing is advanced or delayed in accordance with the detected advance or retardation adjustment amount. (3) The control system includes a spill solenoid that opens and closes a fuel discharge passage communicating from the low pressure chamber to the high pressure chamber of the pump mechanism, and opens the discharge passage at the determined fuel injection start timing.
Claims (1) or (2) characterized in that:
) Distribution type fuel injection pump for the diesel engine described in item 2. (4) The timer mechanism includes a timer piston that drives a roller ring for adjusting the advance or delay of the injection start timing, the injection timing adjustment amount detector consists of a position detector that detects the upright position of the timer piston, and detects the crank angle. The distributed type diesel engine according to claim 2 or 3, wherein the detector comprises a rotation angle detector that detects the rotation angle of a drive shaft included in the pump mechanism. fuel injection pump. (5) The timer mechanism includes a roller ring for adjusting the advance or retardation of the injection start timing, and the state detection system includes a relative rotation angle detector that detects a relative rotation angle between the low rotation ring and the crank angle. The distributed fuel injection pump for a diesel engine according to claim 2 or 3, wherein the injection timing detector is constituted by the relative rotation angle detector. . (6) The distributed fuel for a diesel engine according to claim (5), wherein the relative rotation angle detector detects the relative rotation angle between the low sill ring and the drive shaft or the face cam. 1 injection pump.