JPH112166A - Solenoid valve control type fuel injection pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solenoid valve control type fuel injection pump in which actuation of a plunger and a check valve for discharge (a delivery valve) can be changed over from electric control by a solenoid valve into mechanical control even in the case where a trouble is generated in the solenoid valve or the like to secure the minimum operation functions, and back up control of the solenoid valve. SOLUTION: In the case where a trouble is generated in a solenoid valve 5 or the like, pressure feed of fuel is mechanically started and completed, a fuel cut-off function in a plunger 6 is maintained, and the plunger 6 and a plunger barrel 3 are relatively rotated by forming a lead (inclined lead 21) at a head part of the plunger 6, composing the plunger 6 to be rotatable around its axis as the center, and forming the plunger 6 to be engaged with the lead 21 and a fuel port 11 in the plunger barrel 3 at a specified rotation position for achieving partial load operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic valve control type fuel injection pump, and more particularly to an electromagnetic valve control type fuel injection pump for supplying high pressure fuel to marine and other internal combustion engines.

[0002]

2. Description of the Related Art A conventional solenoid valve control type fuel injection pump 1 will be outlined with reference to FIG. FIG. 7 is a longitudinal sectional view of the electromagnetic valve control type fuel injection pump 1. The electromagnetic valve control type fuel injection pump 1 includes a pump housing 2, a plunger barrel 3, a delivery valve holder 4, and an electromagnetic valve 5.
, A plunger 6, a plunger spring 7, and a tappet 8.

The relative positions of the pump housing 2 and the delivery valve holder 4 are determined by positioning pins 9 and fixed to each other by mounting bolts (not shown). Further, a fuel reservoir 10 is formed between the pump housing 2 and the plunger barrel 3 so that fuel from a fuel tank (not shown) can be retained.

The plunger barrel 3 has a fuel reservoir 1
In addition, a fuel port 11 and a fuel pressure chamber 12 communicating with the fuel pressure chamber 12 and a barrel port (a discharge barrel port 13 and a suction / return barrel port 14) from the fuel pressure chamber 12 are formed, and the plunger 6 is slidably accommodated therein. I have.

The delivery valve holder 4 includes an electromagnetic valve 5
And a discharge barrel port 13 and a suction / return barrel port 1 formed in the plunger barrel 3.
4 are provided with a discharge check valve 15 (delivery valve) and a suction / return check valve 16, respectively, and a control bypass passage 17, a fuel passage 18 and a fuel discharge port 19 are formed.

As shown in the figure, a discharge barrel port 13 and a suction / return barrel port 14 are connected to a fuel passage 18 via a discharge check valve 15 and a suction / return check valve 16, respectively.
The suction-back barrel port 14 is directly connected to the control bypass passage 17 without passing through the suction-back check valve 16.

The solenoid valve 5 opens and closes the discharge check valve 15 with the ascending drive of the plunger 6 receiving a driving force from a driving cam (not shown) of the engine, and is a normally open type or a normal open type. Although any of the closed type can be adopted, the discharge check valve 15 is kept in the “closed” state of the solenoid valve 5 with the upward drive of the plunger 6.
Is set to “open” to start the fuel pumping, and in the “open” state, the discharge check valve 15 is set to “closed” to terminate the pumping. The fuel injection amount is adjusted according to the time between “close” and “open”. The fuel is sucked into the fuel pressure chamber 12 from the fuel port 11 as the plunger 6 moves down.

In the solenoid valve control type fuel injection pump 1 having such a configuration, the solenoid valve 5 is provided in the discharge check valve 15 via the control bypass passage 17, and the compression pressure by the plunger 6 is controlled by the control bypass passage 17. The discharge check valve 1 is bypassed to the passage 17 and turned on / off by the solenoid valve 5.
5 is opened and closed, and a check valve 16 for suction-back is provided according to the reflected pressure.
The fuel will be sucked back from. Therefore, the fuel injection timing, the fuel injection timing, and the fuel injection period can be determined by the control timing of the solenoid valve 5.

Since the amount of fuel to be injected is also controlled by the solenoid valve 5, the plunger 6 only has to function as a pressure-feeding piston, and an inclined lead or other lead is formed on the head thereof. No, lead and fuel port 11
The fuel pumping can be terminated without the fuel cut-off function due to the engagement with the fuel pump.

However, in the event that the solenoid valve 5 fails, this fuel pumping operation becomes impossible. In particular, unlike the case of land-based vehicles, when the fuel injection pump for marine vessels fails, the engine is turned off. There is a problem that the ship stops and the ship drifts.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and can attain a minimum operation function even when a failure occurs in a solenoid valve or a control portion thereof. An object of the present invention is to provide an electromagnetic valve control type fuel injection pump.

Further, the present invention switches the operation of a plunger and a discharge check valve (delivery valve) from electric control by a solenoid valve to mechanical control when a failure occurs in a solenoid valve or a control part thereof. It is an object of the present invention to provide an electromagnetic valve control type fuel injection pump that enables the above.

Another object of the present invention is to provide an electromagnetic valve control type fuel injection pump capable of backing up electromagnetic valve control, particularly in a marine fuel injection pump.

[0014]

That is, the present invention is to provide a plunger which can mechanically start and end fuel pumping when a failure occurs in a solenoid valve or a control part thereof. Focusing on the fact that the cutoff function of the fuel should be preserved, and the fact that the plunger and the plunger barrel are relatively rotated to enable a partial load operation, a pump housing,
A plunger barrel provided in the pump housing and having a fuel pressure chamber and a fuel port and a barrel port communicating with the fuel pressure chamber, and fixed to the pump housing and communicable with the barrel port via a delivery valve. A delivery valve holder formed with a fuel discharge port, a plunger that presses fuel from the fuel pressure chamber to the fuel discharge port through the barrel port and the delivery valve by sliding in the plunger barrel, An electromagnetic valve that controls the pressure in the fuel pressure chamber so as to open and close the fuel discharge port, and an electromagnetic valve control type fuel injection pump having a lead at the head of the plunger, and The plunger is rotatable about its axis, and the plunger is As lead and engageable with the fuel port of the plunger barrel, an electromagnetic valve-controlled fuel injection pump, characterized in that a partial load can be operated Te.

The plunger barrel is rotatable with respect to the pump housing, and the positioning relationship between the lead of the plunger and the fuel port of the plunger barrel is determined by a pin hole for positioning the delivery valve holder and the plunger barrel. Can be selectable.

In the solenoid valve control type fuel injection pump according to the present invention, when the solenoid valve or its control part fails,
Since the plunger was made mechanically operable,
Even if the opening / closing control action by the solenoid valve is not performed, the fuel pumping function can be ensured, and the engine can be operated at a minimum. That is, when the solenoid valve fails, the control bypass passage is closed to forcibly bring the solenoid valve into the "closed" state. Therefore, normally, a normally closed solenoid valve is preferable. After this closed state, the plunger is rotated about its axis to allow its lead to engage the fuel port of the plunger barrel as the plunger slides up and down. Thus,
When the fuel port is closed by the rise of the plunger, the pumping of the fuel is started, and when the plunger further rises and its reed engages with the fuel port, the fuel in the fuel pressure chamber passes through the reed and the fuel port, and the fuel pools. The chamber is cut off, and the fuel pumping ends.

In short, the structure in which the pressure of the fuel pressure chamber is conventionally controlled by opening and closing the solenoid valve to control the pumping of the fuel and the termination thereof is changed to a structure in which the fuel is driven only by the mechanical drive only by the reciprocal sliding of the plunger. The pumping and the termination were performed, and the operation was enabled in a partial load state. Here, the "partial load operation" is a load operation by a stroke from the closing of the fuel port by the top of the plunger to the engagement of the plunger lead with the fuel port of the plunger barrel. Unlike pumping, the fuel injection amount is fixed, but the operation of the engine can be kept to a minimum. Therefore, in the partial load operation, control such as fuel metering and injection timing cannot be performed, but only a minimum operation function can be ensured, and when the solenoid valve and its control circuit are out of order. Backup structure.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a solenoid valve control type fuel injection pump 20 according to a first embodiment of the present invention will be described with reference to FIGS. However, the same parts as those in FIG. 7 are denoted by the same reference numerals, and the detailed description thereof is omitted. FIG.
FIG. 2 is a vertical sectional view of a main part of a solenoid valve control type fuel injection pump 20, particularly showing a configuration of a pump housing 2 and a plunger barrel 3. The solenoid valve control type fuel injection pump 20 is a conventional fuel injection pump in the following points. It is different from the electromagnetic valve control type fuel injection pump 1. That is, a pair of left and right fuel ports 11 of the plunger barrel 3 are provided as a pair of left and right fuel intake and discharge ports, and a pair of left and right inclined leads 21 and a pair of left and right inclined leads 2 engageable with the plunger 6.
A vertical groove 22 communicating with 1 is formed, and a fuel injection amount variable mechanism 23 is further provided. Note that, in the electric control operation by the ordinary solenoid valve 5, the inclined lead 21 does not engage the fuel port 11, and only the top of the plunger 6 feeds the fuel, as outlined based on FIG.
The inclined lead 21 is not involved in the start and end of fuel injection.

That is, when the solenoid valve 5 and its control system fail, the fuel injection start and end timings are controlled by the fuel port 11 and the inclined reed 21, and the pumping fuel is metered by the fuel injection amount variable mechanism 23. . The variable fuel injection amount mechanism 23 includes an injection amount control rack 2.
4 and a control sleeve 25. By operating the injection amount control rack 24 in a direction perpendicular to the plane of the paper in FIG. 1, the plunger 6 can be rotated via the control sleeve 25, and the engagement timing between the inclined lead 21 and the fuel port 11 can be controlled.

FIG. 2 is an exploded view of the inclined lead 21 of the plunger 6. In normal electric operation, the injection amount control rack 24 is set to the full rack position, and the inclined lead 21 is engaged with the fuel port 11. The opening and closing control of the discharge check valve 15 by the solenoid valve 5 is performed using the solenoid valve control type fuel injection pump 1 (FIG. 7) using the head of the plunger 6 in the portion not to be used. In this case, the end and the start of the fuel pumping are not based on the interaction between the inclined lead 21 and the fuel port 11 but by opening and closing the solenoid valve 5 as described above.

In the solenoid valve control type fuel injection pump 20 having the above-described structure, when the solenoid valve 5 and its control part are out of order, the control bypass passage 17 of the solenoid valve 5 is automatically controlled by a signal immediately before the failure or by other means. While the fuel injection amount control rack 24 is closed.
To rotate the plunger 6 to a position where the inclined lead 21 can be engaged with the fuel port 11.

In this engagement position, the fuel can be pumped by the vertical movement of the plunger 6 and the fuel can be cut off when the inclined lead 21 is engaged with the fuel port 11, that is, the fuel pumping can be terminated. The injection amount can be adjusted by controlling the engagement timing between the inclined lead 21 and the fuel port 11 according to the rotation range of the plunger 6, and the operation of the engine can be kept to a minimum.

FIG. 3 is a longitudinal sectional view of a main part of an electromagnetic valve control type fuel injection pump 30 according to a second embodiment of the present invention.
Like the solenoid valve control type fuel injection pumps 1 and 20, the solenoid valve 5
Is used for normal operation, but unlike the solenoid valve control type fuel injection pump 20, the plunger barrel 3 is rotatable with respect to the pump housing 2 without providing the variable fuel injection amount mechanism 23, and the plunger 6 and the fuel The position relative to the port 11 can be changed. However, as in the case of the electromagnetic valve control type fuel injection pump 1 of FIG. 1, the fuel port 11 has a single fuel port.

FIG. 4 is a schematic plan view of the plunger barrel 3, FIG. 5 is a longitudinal sectional view of a main part of the plunger barrel 3 rotated 180 degrees from the state of FIG. 3, and FIG.
FIG. 4 is an exploded view of the inclined lead 21 portion of the plunger 6, and particularly as shown in FIG. 4, a positioning pin hole 31 for positioning the plunger barrel 3 and the delivery valve holder 4, and the discharge barrel. In the example shown, three pairs are formed in the port 13 and the barrel port 14 for suction and suction at predetermined angular intervals in the same diameter direction and in the circumferential direction.

Therefore, in this example, the plunger barrel 3 and the delivery valve holder 4 can be rotated at intervals of 60 degrees, and the positioning pin holes 31,
Discharge barrel port 13 and suction barrel port 1
If the plunger barrel 3 is rotated so that the plungers 4 match each other, the engagement position between the inclined lead 21 of the plunger 6 and the fuel port 11 of the plunger barrel 3 can be adjusted according to the rotational position.

That is, as shown in FIG.
When the solenoid valve 5 or the like fails, this inclined lead 2
1 and the upper lead 32 and the fuel port 11 can be engaged with each other.

Also in the solenoid valve control type fuel injection pump 30 having such a configuration, the minimum operation of the engine when the solenoid valve 5 or its control system fails can be ensured. That is, when a failure occurs, the plunger barrel 3 is rotated by 180 degrees with respect to the pump housing 2 from the state shown in FIG. 3 to the state shown in FIG. They can be engaged with each other. As shown in FIG. 4, by selecting the rotation angle of the plunger barrel 3 with respect to the pump housing 2, any part of the inclined lead 21 and the fuel port 11 can be selected.
Can be controlled in a stepwise manner, and the stroke of the pumping can be selected to adjust the injection amount stepwise.

Thus, although the fuel injection amount is gradual,
The engagement between the inclined lead 21 and the fuel port 11 makes it possible to start and end the pumping of the fuel by mechanical driving, and to minimize the operation of the engine.

[0029]

As described above, according to the present invention, in addition to the normal electric control operation by the solenoid valve, the injection function is mechanically ensured in the event of a failure, etc. An electromagnetic valve control type fuel injection pump having a backup function can be provided.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view of a main part of an electromagnetic valve control type fuel injection pump 20 according to a first embodiment of the present invention.

FIG. 2 is an exploded view of an inclined lead 21 of the plunger 6;

FIG. 3 is a longitudinal sectional view of a main part of an electromagnetic valve control type fuel injection pump 30 according to a second embodiment of the present invention.

FIG. 4 is a schematic plan view of the plunger barrel 3;

5 shows the plunger barrel 3 moved from the state of FIG.
It is a principal part longitudinal cross-sectional view in the state rotated by 0 degree.

FIG. 6 is a development view of the inclined lead 21 of the plunger 6;

FIG. 7 is a longitudinal sectional view of a conventional fuel injection pump 1 controlled by an electromagnetic valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Solenoid valve control type fuel injection pump (FIG. 7) 2 Pump housing 3 Plunger barrel 4 Delivery valve holder 5 Solenoid valve 6 Plunger 7 Plunger spring 8 Tappet 9 Positioning pin 10 Fuel storage chamber 11 Fuel port (fuel intake / discharge port) 12 Fuel pressure Chamber 13 discharge barrel port 14 suction / return barrel port 15 discharge check valve (delivery valve) 16 suction / return check valve 17 control bypass passage 18 fuel passage 19 fuel discharge port 20 solenoid valve control type fuel injection pump ( First Embodiment, FIG. 1) 21 Inclined Lead 22 Vertical Groove 23 Fuel Injection Amount Variable Mechanism 24 Injection Amount Control Rack 25 Control Sleeve 30 Solenoid Valve Controlled Fuel Injection Pump (Second Embodiment, FIG. 3) 31 Pin hole for positioning 32 Upper lead

Claims (2)

[Claims] A pump housing; a plunger barrel provided in the pump housing and having a fuel pressure chamber and a fuel port and a barrel port communicating with the fuel pressure chamber; and a delivery valve fixed to the pump housing. A delivery valve holder formed with a fuel discharge port capable of communicating with the barrel port through the plunger barrel. The fuel from the fuel pressure chamber is slid through the plunger barrel through the barrel port and the delivery valve. An electromagnetic valve control type fuel injection pump, comprising: a plunger that feeds pressure to a discharge port; and an electromagnetic valve that controls pressure in the fuel pressure chamber so as to open and close the fuel discharge port. And make this plunger rotatable about its axis. An electromagnetic valve control type fuel injection pump characterized in that a reed can be engaged with the fuel port of the plunger barrel at a predetermined rotational position of the plunger so that a partial load operation can be performed. 2. The plunger barrel is rotatable with respect to the pump housing, and the lead pin of the plunger and the fuel port of the plunger barrel are formed by a pin hole for positioning the delivery valve holder and the plunger barrel. 2. The solenoid valve control type fuel injection pump according to claim 1, wherein the positional relationship can be selected.