KR960012382B1 - Fuel ejecting pump - Google Patents

Abstract

The fuel injecting pump definitely controls the fuel injection quantity for each cylinder of the diesel engine to optimize driving the engine. The apparatus comprises: a regulator(2) regulating the fuel injection quantity; a timer(3) determining the injection time; a fuel supplying pump(4); a coupling(5) transmitting the combustion power; a plunger(12) reciprocating via a tappet(14); a plunger barrel(13) including a delivery valve(11) at an upper part; a control unit(6) installed outside the plunger barrel(13) and sensing an operation state of the engine and controlling a solenoid valve(16) to regulate the injection quantity.

Description

Fuel injection pump for diesel engine

Figure 1 (a) is an external view of a conventional fuel injection pump.

(b) is a sectional view showing the internal structure of a conventional fuel injection pump.

(c) is a cross-sectional view showing a coupling structure of a conventional plunger and plunger barrel.

(d) is a cross-sectional view showing a combination structure of a conventional delivery valve and a valve seat.

Figure 2 (a) is a cross-sectional view showing the internal structure of the fuel injection pump of the embodiment of the present invention.

(b) is a cross-sectional view showing a coupling structure of the plunger and the plunger barrel of the embodiment of the present invention.

(c) is a cross-sectional view showing a coupling structure of the delivery valve and the valve seat of the embodiment of the present invention.

(d) is sectional drawing which showed the internal structure of the solenoid valve of embodiment of this invention.

(e) is a control block diagram of the solenoid valve of the embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

1: pump body 2: governor

3: timer 4: feed pump

5: Coupling 6: Control Unit

7: lead 8: control rod

9: control sleeve 10: deflector

11: delivery valve 12: plunger

13 plunger barrel 16 solenoid valve

The present invention relates to a fuel injection pump for a diesel engine, and more particularly, to a fuel injection pump for a diesel engine capable of precisely controlling the fuel injection amount while having an extremely simple internal structure.

The fuel injection pump of the diesel engine is an important part that plays a role of applying high pressure to the fuel injection valve by applying high pressure to the fuel flowing from the fuel tank through the supply pump. The general structure and operation principle of the diesel engine are explained as follows. .

First, Figure 1 (a) is an external view of a conventional fuel injection pump, the pump body (1) including a unit fuel injection pump (hereinafter fuel injection pump) for each cylinder, the governor for adjusting the fuel injection amount according to the engine rotation conditions (2), a timer (3) for adjusting the injection timing, a supply pump (4) for supplying fuel in the fuel tank to the fuel injection pump, and a coupling (5) for connecting them to the engine body.

1 (b) is a cross-sectional view showing the internal structure of a conventional fuel injection pump, and these pump bodies 1 are constituted by arranging them on cams having different phases on the same camshaft.

Looking at the operation principle, when the cam shaft 15 is rotated by the power from the crankshaft (not shown), the coaxial cam operates the plunger 12 via the tappet 14. At this time, the plunger 12 has a reciprocating linear motion according to the cam shape. On the other hand, the control rod 8 interlocked with the governor 2 continues to move forward and backward, so that the control sleeve 9 interlocked therewith is configured to rotate left and right accordingly and simultaneously with the control sleeve 9. The plunger 12 also rotates the same amount. That is, the plunger 12 is not a simple rotational motion or a linear motion, but a reciprocating linear motion combined with a rotational motion. As a result, the fuel in the plunger barrel 13 is compressed by the plunger 12 and injected into the fuel injection valve (not shown) via the delivery valve 11.

Here, the upper end of the plunger 12 is formed with a hollow hollow cylindrical groove, the groove is in communication with the outside through the lead (7) in the form of a slanted cutout on the outer peripheral surface of the plunger 12, the lead ( When 7) reaches the fuel outlet formed on the side wall of the plunger barrel 13, the pressurized fuel is all pulled into the fuel passage through the lid 7 and the outlet, so that compression and injection of the fuel are terminated. At this time, the high-pressure fuel in the high-pressure pipe (not shown) interconnecting the delivery valve 11 and the fuel injection valve flows back toward the plunger barrel 13 in which the pressure is significantly lowered, and is also discharged through the outlet. Since an abnormal flow occurs in the fuel passage, there may be a risk of fuel inflow imbalance and damage to the pump housing of each fuel injection pump, and a deflector 10 is installed around the plunger barrel 13 including the discharge port and discharged. Bypassing the route and by dispersing the discharged fuel mitigates the sharpness.

On the other hand, as mentioned above, the plunger 12 is in parallel with the rotational movement, the distance between the lead 7 formed on the outer peripheral surface and the discharge port on the plunger barrel 13, that is, the distance that the fuel injection is actually made also changes. Fuel injection amount is controlled.

In addition, the moment in which the pressurized fuel is discharged through the lid 7 and the discharge port, the pressure in the plunger barrel 13 is reinforced significantly, thereby connecting the delivery valve 11 and the fuel injection valve to each other. The delivery valve 11 is closed (down) by the high pressure remaining in the inside of the back cover. At this time, in the process of lowering the delivery valve 11, the piston 18 of FIG. 1 (d) first closes the hollow portion of the valve seat 17 rather than the face of the valve, thereby closing the hollow portion of the valve seat 17. Maintain the residual pressure at a high level.

As described above, the conventional fuel injection pump is composed of a complex internal structure including a number of related parts for adjusting and terminating the injection amount and for adjusting the over-run of the engine, so that the processing labor is added for each component. Overall, the disassembly and assembly process according to manufacturing and repair was complicated and there was a problem of increasing the weight of the engine.

In addition, since the residual pressure in the high pressure pipe is different depending on the engine speed and the load condition, there is also an operation problem in which the fuel injection amount unevenness occurs per cylinder in the subsequent fuel injection process, resulting in engine vibration.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel injection pump for a diesel engine capable of precisely controlling the fuel injection amount for each cylinder while having an easy internal structure.

In the present invention, the solenoid valve 16 is installed above the delivery valve 11 to open or shut off fuel passing through the high pressure pipe, and the solenoid valve 16 is provided by various sensors and electronic control units. Characterized in that the operation.

Hereinafter, a fuel injection pump of an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 (a) and (b) show the external structure and internal structure of a conventional fuel injection pump, the configuration and operation principle have been described in detail above.

1 (c) is a cross-sectional view showing a conventional plunger 12 and a plunger barrel 13, wherein the plunger 12 is rotated in parallel by the operation of the control rod 8 and the control sleeve 9 above. Thus, the distance between the lead 7 formed on the outer circumferential surface thereof and the outlet on the plunger barrel 13, that is, the distance at which the fuel injection is actually made, is also changed so that the fuel injection amount is adjusted.

1 (d) is a cross-sectional view showing a conventional delivery valve 11 is seated on the valve seat 17, the piston (in the process of the fuel injection is finished and the delivery valve 11 is lowered) 18) By blocking the hollow portion of the valve seat 17 prior to the face portion to block backflow of the high pressure fuel from the high pressure pipe, the constant high pressure in the high pressure pipe is maintained.

As described above, the conventional fuel injection pump as described above has various structural problems and functional defects.

On the other hand, Figure 2 (a) is a cross-sectional view showing the internal structure of the fuel injection pump of the embodiment of the present invention, the solenoid valve 16 operated by the control unit on the delivery valve 11, the high pressure pipe By controlling the amount of injection by opening or blocking the fuel from here, the conventional control rod 8 and the control sleeve which rotates the plunger 12 according to the governor 2 and the engine rotation state to adjust the fuel injection amount. 9) can be deleted. In addition, the conventional deflector 10 installed around the plunger barrel 13 to prevent abnormal flow in the fuel passage and damage to the pump housing which are concerned due to the backflow of the high pressure fuel from the high pressure pipe at the end of the fuel injection. Also deleted.

2 (b) is a cross-sectional view showing a coupling structure of the plunger 12 and the plunger barrel 13 of the embodiment of the present invention, the solenoid valve 16 as long as the plunger 12 repeats a predetermined amount of fuel feed Since the plunger 12 has a structure for adjusting the injection amount in itself, the plunger 12 does not need a separate function for adjusting the injection amount with the conventional lead 7. On the other hand, a seat for installing the solenoid valve 16 in the plunger barrel 13 is formed.

Figure 2 (c) is a cross-sectional view showing a state in which the delivery valve 11 of the embodiment of the present invention seated on the valve seat 17, the fuel to the high-pressure pipe is opened or blocked by the solenoid valve 16. As such, the delivery valve 11 is characterized in that there is no separate processing part for blocking the reverse flow as in the conventional piston 18.

2 (d) is a sectional view showing the internal structure of the solenoid valve 16 according to the embodiment of the present invention. In the case where the valve 22 is reversed by an electrical signal from the control unit, the high pressure passing through the delivery valve 11 is shown. The fuel is discharged into the fuel passage along the path indicated by the arrow, so that the fuel to the high pressure pipe is blocked. On the other hand, the valve body 19, the valve housing 20, the spring 23 and the magnet 24, etc. are the main components constituting the solenoid valve 16 of the present invention by the fastening screw 21 by the plunger barrel 13 ) Are integrally combined.

In addition, Figure 2 (e) is a configuration for controlling the solenoid valve 16 of the embodiment of the present invention, the solenoid valve is a magnetic flux pedal position sensor 25, the boost pressure sensor 26, the water temperature sensor 27 and When the operating state of the engine is sensed through the pump speed sensor 28, the control unit 6 determines the appropriate fuel injection amount based on this, thereby precisely controlling the operation of each solenoid valve 16, Residual pressure is also maintained uniformly for each cylinder to maintain optimum operation without problems such as engine vibration due to the aforementioned fuel injection irregularities.

In the present invention, the solenoid valve 16 is provided on the delivery valve 11 to open or shut off fuel passing through the high-pressure pipe, and the solenoid valve (6) is controlled by various sensors and control units 6. By operating 16), the internal structure of the fuel injection pump can be simplified to facilitate the processing, and the fuel injection amount of each cylinder can be accurately controlled to maintain the optimum operation of the engine.

In addition, there is an advantage that can reduce the amount of fuel by reducing the overall weight of the engine.

Claims (2)

It is provided with a governor (2) for adjusting the fuel injection amount, a timer (3) for adjusting the injection timing and a supply pump (4) for pumping fuel to inject the fuel by the coupling (5) to transmit the driving force of the engine In the injection pump, a plunger (12) reciprocating through a tappet (14) via a camshaft (15) built up in the injection pump, and the plunger slides on the hollow portion and a delivery valve (11) is installed upward. Controlled by the plunger barrel 13 and the control unit 6 installed outside the plunger barrel and sensing the operating state of the engine and controlled by the control unit 6 sensing the operating state of the engine. A fuel injection pump for a diesel engine, characterized in that the solenoid valve 16 is configured to control the injection amount, the end of the injection, and the overrun of the engine by the control operation of the solenoid valve. The fuel injection pump of claim 1, wherein the upper end of the plunger (12) has a round bar shape.