JP7172851B2 - metering device - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a technique for metering a pumping amount of a fuel injection pump.

2. Description of the Related Art In a fuel injection pump that pressurizes and pumps fuel, a technique is known in which a metering device adjusts the pumping amount of the fuel injection pump.
For example, in Patent Document 1 below, in a solenoid valve used in a metering device, a movable portion that reciprocates by controlling energization of a coil that is a driving portion is provided with a It is described that a communication path is provided to communicate the space of the In the technique described in Patent Document 1, by providing a communication path in the movable part, the pressure difference between the spaces on both sides of the reciprocating direction of the movable part is reduced, and the responsiveness of the reciprocating movement of the movable part is improved. and

Japanese Patent No. 5857878

However, in the technique described in Patent Literature 1, in one of the spaces on both sides of the movable portion in the reciprocating direction, there is not formed a passage through which surplus fuel flows other than the communication passage of the movable portion. Therefore, surplus fuel that flows into one space from the inlet of the communicating passage returns to the other space through the inlet of the communicating passage as an outlet.

As a result of detailed studies by the inventor, it was found that in the configuration of the metering device described in Patent Document 1, surplus fuel in the metering device is difficult to be discharged through the movable part, so that foreign matter inside the metering device is excessive. A problem was found in that it was difficult to be discharged together with the fuel.

In one aspect of the present disclosure, it is desirable to provide a technique for easily discharging foreign matter inside a metering device together with excess fuel.

A metering device (40, 80, 110) according to one aspect of the present disclosure is a metering device for metering fuel flow pumped from a fuel injection pump (20), comprising a valve seat (42a), a valve a member (44), a drive section (68), a movable section (50, 90, 120, 130, 140), fuel flow paths (214-218, 222, 230, 232, 240, 250-254, 260, 270, 280).

When the valve member leaves the valve seat, the fuel is sucked into the pressurizing chamber in the suction stroke in which the plunger moves in the direction opposite to the pressurizing direction in which the fuel is pressurized in the pressurizing chamber, and the plunger moves in the pressurizing direction. By seating on the valve seat during the moving pumping stroke, the fuel in the pressurization chamber is pressurized and pumped by the plunger.

The movable portion changes its position by controlling the energization of the driving portion, and the valve member switches between being seated on the valve seat and being separated from the valve seat by changing the position.
The fuel channel passes through at least one of the inside and the outside of the movable part, and has different inlets and outlets through which surplus fuel is discharged.

According to such a configuration, foreign matter inside the metering device is discharged together with surplus fuel from the fuel flow path passing through at least one of the inside and outside of the movable portion. Furthermore, since the inlet and the outlet of the fuel channel through which excess fuel is discharged are not the same but different, foreign objects inside the metering device are not returned to the inlet side of the fuel channel, but are It is discharged from the outlet of the fuel flow path.

1 is a schematic diagram showing the configuration of a fuel injection pump according to a first embodiment; FIG. Sectional drawing which shows the metering valve at the time of valve opening. Sectional drawing which shows the metering valve at the time of valve closing. Sectional drawing which shows the structure of a movable part. FIG. 5 is a cross-sectional view taken along the line VV of FIG. 4; A sectional view taken along line VI-VI of FIG. The time chart which shows the operation|movement of a metering valve. FIG. 4 is a schematic diagram showing a fuel discharge channel and a rod according to the first embodiment; IX direction arrow directional view of FIG. FIG. 4 is a characteristic diagram showing changes in flow area of the fuel discharge flow path when energization to the metering valve is turned on and off; FIG. 4 is a characteristic diagram showing changes in flow area of the fuel discharge flow path when duty control is performed on energization of the metering valve; FIG. 4 is a cross-sectional view showing a desirable configuration of the movable core; FIG. 4 is a cross-sectional view showing the preferred configuration of the rod; Sectional drawing which shows the metering valve at the time of valve opening of 2nd Embodiment. Sectional drawing which shows the metering valve at the time of valve closing. Sectional drawing which shows the metering valve at the time of valve opening of 3rd Embodiment. Sectional drawing which shows the metering valve at the time of valve closing. The fragmentary sectional view which shows the rod of 4th Embodiment. The schematic diagram which shows the fuel discharge flow path and rod of 5th Embodiment. XX direction arrow directional view of FIG. FIG. 4 is a characteristic diagram showing changes in flow area of the fuel discharge flow path when energization to the metering valve is turned on and off; FIG. 4 is a characteristic diagram showing changes in flow area of the fuel discharge flow path when duty control is performed on energization of the metering valve; The schematic diagram which shows the fuel discharge flow path and rod of 6th Embodiment. FIG. 4 is a characteristic diagram showing changes in flow area of the fuel discharge flow path when energization to the metering valve is turned on and off; FIG. 4 is a characteristic diagram showing changes in flow area of the fuel discharge flow path when duty control is performed on energization of the metering valve; The schematic diagram which shows the fuel discharge flow path and rod of 7th Embodiment. FIG. 12 is a characteristic diagram showing the relationship between the energization of the metering valve and the channel area of the fuel discharge channel in the seventh embodiment; The schematic diagram which shows the fuel discharge flow path and rod of 8th Embodiment. FIG. 12 is a characteristic diagram showing the relationship between the energization of the metering valve and the flow area of the fuel discharge flow path according to the eighth embodiment;

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.
[1. First Embodiment]
[1-1. Constitution]
The fuel supply system 2 of the present embodiment shown in FIG. 1 supplies fuel to, for example, a common rail (not shown) that accumulates fuel to be supplied to a fuel injection valve (not shown). The fuel supply system 2 includes a fuel filter 10, a main tank 12, a sub-tank 14, a feed pump 16, a jet pump 18, a fuel injection pump 20, and an ECU 100. ECU is an abbreviation for Electronic Control Unit.

The fuel filter 10 removes foreign matter from the fuel supplied by the electric feed pump 16 from the main tank 12 through the fuel passage 200 . The fuel from which foreign matter has been removed by the fuel filter 10 is supplied to the fuel injection pump 20 .

The main tank 12 and the sub-tank 14 may be so-called saddle-type fuel tanks in which the fuel chambers are independent, but the tank cases are connected, or the tank cases are installed separately. may be configured.

The jet pump 18 generates negative pressure by ejecting surplus fuel discharged from the fuel supply passage from the main tank 12 to the fuel injection valve into the main tank 12 through the fuel discharge passage 202 from the nozzle. The jet pump 18 sucks up fuel from the sub-tank 14 by the generated negative pressure and transfers it to the main tank 12 . Surplus fuel is discharged from the fuel injection pump 20 , the common rail, and the fuel injection valves into the fuel discharge passage 202 .

Fuel injection pump 20 includes orifice 22 , roller 30 , tappet 32 , plunger 34 , spring 36 , check valve 38 and metering valve 40 .
The orifice 22 determines the maximum flow rate of excess fuel discharged from the fuel supplied to the fuel injection pump 20 through the fuel filter 10 by the orifice diameter.

Roller 30, tappet 32 and plunger 34 are loaded from spring 36 towards the cam. The tappet 32 and plunger 34 reciprocate together with the roller 30 as the roller 30 rotates along the profile of the cam (not shown).

By reciprocating the plunger 34 , the fuel that passes through the fuel filter 10 and is sucked from the fuel flow path 204 into the pressurization chamber 206 is pressurized, and the pressurized fuel is pressure-fed from the check valve 38 . Fuel pumped from the check valve 38 is supplied to the common rail through the fuel passage 208 .

The metering valve 40 permits the intake of fuel from the fuel passage 204 into the pressurizing chamber 206 by opening, and permits the intake of fuel from the fuel passage 204 to the pressurizing chamber 206 by closing. prohibited. When the metering valve 40 is closed in the pressurizing stroke in which the plunger 34 moves in the pressurizing direction to pressurize the fuel in the pressurizing chamber 206, pressurization of the fuel in the pressurizing chamber 206 is started.

The ECU 100 includes a microcomputer having a CPU and semiconductor memory such as RAM or ROM. The ECU 100 may have one microcomputer or may have a plurality of microcomputers.

The ECU 100 controls the valve closing timing of the metering valve 40 by controlling the energization of a coil 68 (described later) of the metering valve 40 . In the pumping stroke, the ECU 100 controls the closing timing of the metering valve 40 to meter the amount of fuel pumped from the fuel injection pump 20 .

Next, the configuration of the metering valve 40 will be described with reference to FIG.
The metering valve 40 includes a valve body 42, a valve member 44, a spring seat 46, a spring 48, a movable portion 50, a valve body 56, a stopper 58, a spring 60, a magnetic member 62, and a non-magnetic member. It comprises a member 64 , a stationary core 66 , a coil 68 and a yoke 70 .

A fuel passage 204 is formed in the valve body 42 to guide the fuel supplied from the fuel filter 10 to the fuel injection pump 20 to the pressurizing chamber 206 . The valve body 42 supports the valve member 44 so as to be able to reciprocate. Further, the valve body 42 is formed with a valve seat 42a on which the valve member 44 is seated.

When the valve member 44 is seated on the valve seat 42a, the metering valve 40 is closed and the intake of fuel from the fuel passage 204 to the pressurizing chamber 206 is blocked. When the valve member 44 is separated from the valve seat 42a, the metering valve 40 is opened, and the intake of fuel from the fuel passage 204 to the pressurizing chamber 206 is permitted.

A plurality of planar portions are formed in the circumferential direction along the reciprocating direction of the valve member 44 on the outer peripheral surface of the valve member 44 . The planar portion of the valve member 44 and the inner peripheral surface of the cylindrical valve body 42 form a plurality of fuel flow passages 210 in the circumferential direction of the valve member 44, which communicate the fuel flow passages 204 with a fuel space 212, which will be described later. formed.

The spring seat 46 is fixed to the valve member 44 by, for example, welding. The spring 48 applies a load to the spring seat 46 in the direction in which the valve member 44 is pressed against the rod 52 of the movable portion 50, which will be described later, that is, in the direction in which the valve member 44 is seated on the valve seat 42a. Spring seat 46 and spring 48 are housed in fuel space 212 defined by valve body 42 and valve body 56 .

The movable part 50 has a rod 52 and a movable core 54 . The rod 52 is fixed to the movable core 54 by, for example, welding. Movable core 54 is housed in fuel space 220 .

As shown in FIGS. 2 to 6, the outer peripheral surface of the rod 52 is formed with a plurality of planar portions in the circumferential direction along the reciprocating direction of the rod 52 . The planar portion of the rod 52 and the inner peripheral surface of the cylindrical valve body 56 form a plurality of fuel passages 214 that communicate the fuel spaces 212 and 220 in the circumferential direction of the rod 52 .

Further, as shown in FIGS. 2 to 4 and 6, grooves are formed on the outer peripheral surface of the rod 52 to connect adjacent planar portions of the rod 52 in the circumferential direction. The groove of the rod 52 and the inner peripheral surface of the valve body 56 form a communicating passage 216 that communicates between the adjacent fuel passages 214 in the circumferential direction. A plurality of communication passages 222 are formed in the movable core 54 in the circumferential direction through the movable core 54 in the axial direction.

The valve body 56 supports the rod 52 so as to be able to reciprocate. The valve body 56 is formed with a fuel discharge passage 218 that communicates with a communication passage 216 formed on the rod 52 side in the state shown in FIG. 2 in which the coil 68 is de-energized. Fuel discharge channel 218 discharges excess fuel to fuel discharge channel 202 .

Therefore, in the state shown in FIG. 2 in which the coil 68 is de-energized, the surplus fuel in the metering valve 40 flows through the fuel passage 214 as an inlet, the fuel passage 214, the communication passage 216, and the fuel discharge passage. 218 and is discharged through a fuel discharge channel 218 different from the fuel channel 214 as an outlet. Therefore, the excess fuel in the metering valve 40 is discharged to the fuel discharge passage 202 without the fuel flow returning from the inlet to the outlet or flowing backward.

When the coil 68 is energized, the stopper 58 moves the rod 52 to the position shown in FIG. to stop. When the rod 52 moves to the fixed core 66 side, the valve member 44 is seated on the valve seat 42 a by the load received from the spring 48 . When the valve member 44 is seated on the valve seat 42a, the metering valve 40 is opened.

When the coil 68 is energized, the movement distance of the rod 52 from the state shown in FIG. Longer than the travel distance to sit down. Since the valve member 44 and the rod 52 are separate members, the rod 52 reciprocates between the valve member 44 and the rod 52 in the state shown in FIG. A possible interval is formed.

A spring 60 is mounted around the stopper 58 and applies a load to the rod 52 in the direction of pressing the rod 52 against the valve member 44, that is, in the direction of separating the valve member 44 from the valve seat 42a. The load applied to the rod 52 by the spring 60 in the direction in which the valve member 44 leaves the valve seat 42a is greater than the load applied to the spring seat 46 in the direction in which the valve member 44 is seated on the valve seat 42a.

Therefore, in the state shown in FIG. 2, in which the coil 68 is de-energized and no magnetic attraction is acting between the movable core 54 and the fixed core 66, the difference in load between the spring 48 and the spring 60 causes the rod to 52 pushes the valve member 44 in the direction away from the valve seat 42a. As a result, when the valve member 44 is separated from the valve seat 42a, the metering valve 40 is opened.

The magnetic member 62 and the non-magnetic member 64 cover the outer circumference of the movable core 54 . The magnetic member 62 supports the movable core 54 so as to be able to reciprocate. The non-magnetic member 64 is installed between the magnetic member 62 and the fixed core 66 to prevent the magnetic member 62 and the fixed core 66 from being magnetically short-circuited.

A coil 68 covers the outer circumferences of the magnetic member 62 , the non-magnetic member 64 and the fixed core 66 . The yoke 70 covers the outer circumference of the coil 68 and magnetically connects the magnetic member 62 and the fixed core 66 .

The magnetic flux generated by the coil 68 when the power is turned on flows through the magnetic circuit formed by the movable core 54 , the magnetic member 62 , the fixed core 66 and the yoke 70 . Magnetic flux flows through the magnetic gap between the movable core 54 and the fixed core 66, and magnetic attraction acts between the movable core 54 and the fixed core 66. As shown in FIG. The movable core 54 is attracted to the fixed core 66 side against.

Further, as shown in FIG. 3, when the coil 68 is energized and the movable core 54 is attracted toward the fixed core 66 against the load of the spring 60, the rod 52 moves. and the fuel discharge passage 218 are displaced from each other in the axial direction. As a result, communication between the communication passage 216 and the fuel discharge passage 218 is cut off, so that the surplus fuel discharged from the metering valve 40 through the fuel discharge passage 218 becomes zero.

[1-2. process]
Next, the flow rate control process of the surplus fuel discharged from the metering valve 40 by the ECU 100 controlling the energization of the metering valve 40 will be described.

(1) During normal control As shown in FIG. 7, in normal energization control, the ECU 100 controls the coil 68 during a suction stroke in which the plunger 34 moves in a direction opposite to the pressurizing direction in which the fuel in the pressurizing chamber 206 is pressurized. power is turned off. As a result, as shown in FIG. 2, the valve member 44 is separated from the valve seat 42a, so that the metering valve 40 is opened.

In this case, when the coil 68 is energized, the movable core 54 is attracted toward the fixed core 66, and even if the rod 52 moves together with the movable core 54, the flow of fuel from the fuel flow path 204 into the pressurization chamber 206 is prevented. As a result, the valve member 44 maintains the state of being separated from the valve seat 42a. Therefore, in the intake stroke, regardless of whether the coil 68 is energized or off, that is, regardless of the position of the movable portion 50, the metering valve 40 opens and fuel is supplied to the pressurizing chamber 206. flows in.

That is, in the intake stroke, the ECU 100 controls the length of time during which the coil 68 is energized, and changes the position of the movable portion 50 without changing the position of the valve member 44, thereby adjusting the metering amount. The amount of excess fuel discharged from the valve 40 can be controlled.

In addition, during the pumping stroke in which the plunger 34 moves in the pressurizing direction for pressurizing the fuel in the pressurizing chamber 206, the ECU 100 adjusts the coil at a predetermined timing of the pumping stroke so that the pumping amount required for the current pumping stroke is obtained. Power to 68 is turned on.

When the coil 68 is energized, the rod 52 moves together with the movable core 54 toward the fixed core 66 and reaches the upper end where it contacts the stopper 58. Therefore, the load received from the spring 48 causes the valve member 44 to move toward the valve seat 42a. take a seat. As a result, the metering valve 40 closes, and the plunger 34 moves in the pressurizing direction, pressurizing the fuel in the pressurizing chamber 206 and pumping the pressurized fuel from the check valve 38 .

As shown in FIG. 7, there is a time delay from when the coil 68 is energized until the valve member 44 is seated on the valve seat 42a and the metering valve 40 is closed.
When the valve member 44 is seated on the valve seat 42a in the pumping stroke, even if the coil 68 is de-energized, the force that the rod 52 receives from the fuel pressure in the pressure chamber 206 is greater than the load that the rod 52 receives from the spring 60 in the valve opening direction. and the load received from the spring 48, the force received by the valve member 44 in the valve closing direction is greater.

Therefore, in the pumping stroke, when the valve member 44 is seated on the valve seat 42a and the metering valve 40 is closed, the energization of the coil 68 may be controlled either on or off.
That is, when the valve member 44 is seated on the valve seat 42a and the metering valve 40 is closed in the pumping stroke, the ECU 100 controls the length of time during which the coil 68 is energized so that the valve member 44 is closed. By changing the position of the movable part 50 without changing the position, the amount of excess fuel discharged from the metering valve 40 can be controlled.

In this way, when the coil 68 is energized in both the suction stroke and the pumping stroke, the movable part 50 moves in the direction in which the valve member 44 is seated on the valve seat 42a, and the coil 68 is energized. When turned off, the movable portion 50 moves in the direction in which the valve member 44 is separated from the valve seat 42a. In both the suction stroke and the pumping stroke, the discharge amount of surplus fuel is controlled by controlling the energization of the coil 68 .

For example, when it is desired to increase the flow rate of fuel flowing through the jet pump 18 to increase the flow rate of fuel transferred from the sub-tank 14 to the main tank 12 because the remaining amount of fuel in the main tank 12 has decreased, the coil 68 is energized. The amount of excess fuel discharged from the metering valve 40 is increased by shortening the ON time.

On the other hand, if the pumping amount required for the electric feed pump 16 increases, the drive current supplied to the feed pump 16 increases to increase the rotation speed of the feed pump 16, so the power consumption of the feed pump 16 increases. do. As the power consumption of the feed pump 16 increases, the fuel consumption increases in order to increase the power generated by the generator.

In order to suppress an increase in the fuel consumption of the feed pump 16, it is desirable to suppress an increase in the required pumping amount of the electric feed pump 16 as much as possible. Therefore, it is conceivable to reduce the amount of surplus fuel discharged from the metering valve 40 by increasing the time during which the coil 68 of the metering valve 40 is energized. If the discharge amount of surplus fuel discharged from the metering valve 40 is reduced, the required pumping amount for the feed pump 16 is reduced.

Generally, the power consumption of the coil 68 of the metering valve 40 is less than the power consumption of the feed pump 16 . Therefore, even if the amount of power consumption of the metering valve 40 increases by increasing the time during which the coil 68 of the metering valve 40 is energized, the amount of reduction in the power consumption of the feed pump 16 is greater. . As a result, an increase in fuel consumption can be suppressed as a whole.

(2) No pressure feed at high speed When the engine is rotating at high speed and the required pressure feed amount for the fuel injection pump 20 is 0, the metering valve 40 is open during the entire period of the pressure feed stroke. . In this case, it is conceivable to leave the coil 68 de-energized to increase the discharge amount of excess fuel.

As a result, by moving the plunger 34 in the pressurizing direction, the flow rate of the fuel returned to the fuel flow path 204 side is reduced, so that the pressure pulsation generated on the low pressure side of the fuel can be reduced.
(3) Pressure feed at high speed Even if the engine rotates at high speed and the period of the intake stroke is shortened, it is required to draw the required amount of fuel from the fuel passage 204 into the pressurization chamber 206 . In this case, it is conceivable that the coil 68 is energized during the intake stroke so that the discharge amount of surplus fuel is zero.

As a result, part of the fuel sucked into the pressurizing chamber 206 from the fuel passage 204 during the intake stroke is not discharged from the fuel discharge passage 218, and the fuel pressure on the fuel space 212 side rises. As a result, even if the period of the intake stroke is shortened, the required flow rate of fuel flows from the fuel passage 204 into the pressurization chamber 206 .

(4) High-speed rotation and high load When the engine rotates at high speed under high-load conditions, the temperature of surplus fuel discharged from the common rail and the engine increases. In this case, it is conceivable to increase the amount of surplus fuel discharged from the metering valve 40 by lengthening the time during which the coil 68 is de-energized.

Normally, the temperature of excess fuel discharged from the metering valve 40 is lower than the temperature of excess fuel discharged from the common rail or the engine side. Therefore, by increasing the discharge amount of surplus fuel discharged from the metering valve 40, it is possible to suppress the temperature rise of the surplus fuel as a whole.

In the energization control to the coil 68 described above, as shown in FIGS. Excess fuel is discharged. When the coil 68 is energized, the movable portion 50 is at the position indicated by the two-dot chain line, so excess fuel is not discharged from the fuel discharge passage 218 .

8 and 9 schematically show the relationship between ON/OFF switching of the energization of the coil 68 and the opening and closing of the fuel discharge passage 218 by the movable portion 50. The actual movable portion 50 and the configuration of the fuel discharge channel 218 .

As shown in FIG. 10, the flow area 400 of the fuel discharge flow path 218 changes between 0 and maximum by switching the energization of the coil 68 on and off.
On the other hand, like the characteristic 402 shown in FIG. 11, the passage area of the fuel discharge passage 218 may be variably controlled by duty-controlling the energization of the coil 68 between 0 and 100%. . By variably controlling the passage area of the fuel discharge passage 218, the amount of fuel discharged from the fuel discharge passage 218 is variably controlled.

The reciprocating position of the movable part 50 can be changed between the state in which the valve member 44 is seated on the valve seat 42a and the state in which the valve member 44 is separated from the valve seat 42a by ON/OFF control or duty control of the energization of the coil 68. It changes in both sitting and sitting.

[1-3. Desirable configuration of the first embodiment]
In the configuration of the first embodiment, when the position of the rod 52 in the rotational direction shifts, the energization of the coil 68 is turned off, and the rod 52 is positioned at the reciprocating position where the communication passage 216 and the fuel discharge passage 218 are in communication. However, the communication passage 216 and the fuel discharge passage 218 may not communicate with each other, and the surplus fuel may not be discharged.

Therefore, by forming a plane portion 54a on the outer peripheral surface of the movable core 54 as shown in FIG. 12 or by forming a plane portion 52a on the outer peripheral surface of the rod 52 as shown in FIG. should be prevented from rotating.

When the flat portion 54a is formed on the movable core 54, a flat surface in contact with the flat portion 54a is provided at a position in the circumferential direction corresponding to the flat portion 54a on the inner peripheral surface of the magnetic member 62 that supports the movable core 54 so as to be able to reciprocate. part is formed.

When the flat portion 52a is formed on the rod 52, a flat portion in contact with the flat portion 52a is provided at a position in the circumferential direction corresponding to the flat portion 52a on the inner peripheral surface of the valve body 56 that supports the rod 52 so as to be able to reciprocate. It is formed.

In the first embodiment, the fuel flow path 214, the communication path 216, and the fuel discharge flow path 218 correspond to fuel flow paths having different inlets and outlets for discharging surplus fuel. Also, the coil 68 corresponds to the drive section, and the ECU 100 corresponds to the control section.

Further, only the metering valve 40 may correspond to the metering device, or the metering valve 40 and the ECU 100 may correspond to the metering device.
[1-4. effect]
According to the first embodiment described above, the following effects can be obtained.

(1a) Excess fuel in the metering valve 40 passes through a fuel flow path formed by a fuel flow path 214, a communication path 216, and a fuel discharge flow path 218, and has different inlets and outlets. It exits the metering valve 40 without backflow or backflow. Therefore, the foreign matter inside the metering valve 40 does not remain inside the metering valve 40 and is easily discharged from the metering valve 40 .

(1b) Excess fuel is discharged from the metering valve 40 through the fuel passage 214, the communication passage 216, and the fuel discharge passage 218 by controlling the energization of the coil 68. No new parts need to be added for this purpose.

(1c) The length of time during which energization to the coil 68 is turned off or on during a period unrelated to metering control for controlling the valve closing timing of the metering valve 40 to meter the pumping amount of the fuel injection pump 20. By controlling the depth, the required discharge amount of excess fuel can be discharged from the metering valve 40 . The longer the coil 68 is de-energized, the more excess fuel is discharged.

(1d) When duty control is performed on the energization of the coil 68, the required amount of surplus fuel can be discharged from the metering valve 40 by setting the duty according to the required amount of discharge.

[2. Second Embodiment]
[2-1. Differences from First Embodiment]
Since the basic configuration of the second embodiment is the same as that of the first embodiment, differences will be described below. Note that the same reference numerals as in the first embodiment indicate substantially the same configurations, and refer to the preceding description.

In the second embodiment, the configuration of the fuel flow path for discharging surplus fuel from the metering valve is different from the configuration of the fuel flow path of the first embodiment described above.
As shown in FIGS. 14 and 15, in the metering valve 80 of the second embodiment, the rod 92 of the movable portion 90 protrudes from the movable core 54 and extends toward the moving side when the coil 68 is energized. It has a protrusion 94 .

A fuel discharge passage 230 is formed between the stopper 96 of the spring 60 and the fixed core 66 . Furthermore, in the inner peripheral surface of the fixed core 66, a groove extending axially from the open end on the movable core 54 side communicates the fuel space 220 with the internal space of the fixed core 66 around the projection 94. A communication passage 232 is provided. is formed.

As shown in FIG. 14, when the coil 68 is de-energized, the rod 92 is separated from the stopper 96 by the load applied by the spring 60, so that excess fuel in the metering valve 80 flows through the fuel passage 214 into the inlet. , and is discharged from the communicating passages 222 and 232 to the fuel discharge passage 202 through a fuel discharge passage 230 different from the fuel passage 214 as an outlet.

As shown in FIG. 15 , when the coil 68 is energized, the rod 92 moves together with the movable core 54 toward the stopper 96 and closes the fuel discharge passage 230 with the end surface of the projecting portion 94 . Excess fuel is therefore not discharged from metering valve 80 .

In the second embodiment, the fuel passage 214, the communication passages 222 and 232, and the fuel discharge passage 230 correspond to fuel passages having different inlets and outlets for discharging excess fuel of the metering valve 80. FIG.
[2-2. effect]
According to the second embodiment described above, in the effects (1a) to (1c) of the first embodiment described above, the metering valve 40 is replaced with the metering valve 80, and the inlet and outlet for discharging surplus fuel are provided. It is possible to obtain the effect of replacing the fuel flow paths with different diameters by the fuel flow path 214, the communication paths 222 and 232, and the fuel discharge flow path 230.

Furthermore, according to the second embodiment, the following effects can be obtained.
(2a) Since the rod 92 closes the fuel discharge passage 230 at the end surface of the projecting portion 94, the fuel discharge passage 230 can be closed regardless of the position of the rod 92 in the rotational direction when the coil 68 is energized. can be done. Therefore, it is not necessary to process the movable core 54 or the rod 92 to prevent the rotation of the movable portion 90 .

[3. Third Embodiment]
[3-1. Difference from Second Embodiment]
Since the basic configuration of the third embodiment is the same as that of the second embodiment, differences will be described below. Note that the same reference numerals as in the second embodiment indicate the same configurations, and refer to the preceding description.

In the second embodiment described above, the rod 92 closes the fuel discharge channel 230 with the end surface of the projecting portion 94 of the rod 92 .
On the other hand, in the metering valve 110 of the third embodiment shown in FIGS. 16 and 17, the rod 122 of the movable portion 120 closes the fuel discharge flow path 240 on the outer peripheral side surface of the protruding portion 124, which is similar to that of the second embodiment. is different from

Specifically, the rod 122 of the movable portion 120 has a protruding portion 124 protruding from the movable core 54 on the side of the stopper 58 where the rod 122 moves when the coil 68 is energized. A fuel discharge passage 240 that can communicate with the space of the projecting portion 124 on the side of the stopper 58 is formed in the fixed core 66 , the non-magnetic member 64 and the valve body 56 . The communication passage 232 communicates the fuel space 220 and the space of the projecting portion 124 on the stopper 58 side.

As shown in FIG. 16 , when the coil 68 is de-energized, the rod 122 moves toward the valve member 44 due to the load received from the spring 60 , so that the fuel discharge passage 240 moves toward the stopper 58 side of the projecting portion 124 . The opening that communicates with the space is opened without being closed by the outer peripheral side surface of the projecting portion 124 . The fuel space 220 and the space of the projecting portion 124 on the side of the stopper 58 communicate with each other through a communicating passage 232 .

Therefore, the surplus fuel in the metering valve 110 enters the fuel passage 214, passes through the communication passages 222 and 232, and exits through the fuel discharge passage 240, which is different from the fuel passage 214, and is discharged to the fuel discharge passage 202. be.

As shown in FIG. 17 , when the coil 68 is energized, the rod 122 moves together with the movable core 54 toward the fixed core 66 and closes the fuel discharge passage 240 with the outer peripheral side surface of the projecting portion 124 . Excess fuel is therefore not discharged from metering valve 110 .

In the third embodiment, the fuel passage 214, the communication passages 222 and 232, and the fuel discharge passage 240 correspond to fuel passages having different inlets and outlets for discharging excess fuel of the metering valve 110. FIG.
[3-2. effect]
According to the third embodiment described above, the effects (1a) to (1d) of the first embodiment and the effect (2a) of the second embodiment are obtained by replacing the metering valves 40 and 80 with the metering valve 110. , the movable parts 50 and 90 are replaced with the movable part 120, the end surface of the protruding part 94 is replaced with the outer peripheral side surface of the protruding part 124, and the fuel discharge flow paths 218 and 230 are replaced with the fuel discharge flow path 240. can be done.

[4. Fourth Embodiment]
[4-1. Differences from First Embodiment]
Since the basic configuration of the fourth embodiment is the same as that of the first embodiment, differences will be described below. Note that the same reference numerals as in the first embodiment indicate the same configurations, and refer to the preceding description.

In the first embodiment described above, between the outer peripheral surface of the rod 52 and the inner peripheral surface of the valve body 56, the fuel passage 214 and the communication passage 216 are formed for discharging surplus fuel. It is

In contrast, the fourth embodiment shown in FIG. 18 differs from the first embodiment in that a fuel passage 250 for discharging excess fuel is formed inside the rod 132 of the movable portion 130 .
The fuel flow path 250 is formed extending in the axial direction of the rod 132 and communicates with the fuel space 212 regardless of the position of the rod 132 in the reciprocating direction. Furthermore, the fuel flow path 250 extends radially toward the outer peripheral surface of the rod 132 at a position spaced apart in the axial direction and opens to the outer peripheral surface of the rod 132 .

An annular fuel discharge passage 252 and a fuel discharge passage 254 communicating with the fuel discharge passage 252 and discharging surplus fuel to the fuel discharge passage 202 are formed on the inner peripheral surface of the valve body 56 . .
When the coil 68 is de-energized, the rod 132 is in the position shown in FIG. Therefore, the surplus fuel in the metering valve 40 is discharged from the fuel discharge channel 252 to the fuel discharge channel 202 through the fuel discharge channel 252 as an inlet and the fuel discharge channel 254 different from the fuel channel 250 as an outlet. .

When the coil 68 is energized, the rod 132 moves from the position shown in FIG. It is cut off by the outer peripheral surface. Therefore, the surplus fuel in the metering valve 40 passes from the fuel passage 250 through the fuel discharge passages 252 and 254 and is not discharged to the fuel discharge passage 202 .

In the fourth embodiment, the fuel flow path 250 and the fuel discharge flow paths 252 and 254 correspond to the fuel flow paths having different inlets and outlets for discharging excess fuel of the metering valve 40 .
[4-2. effect]
According to the fourth embodiment described above, in the effects (1a) to (1d) of the first embodiment described above, the fuel flow path having different inlets and outlets for discharging surplus fuel is replaced with the fuel flow path 250. The effect of replacing with the fuel discharge passages 252 and 254 can be obtained.

Furthermore, according to the fourth embodiment, the following effects can be obtained.
(4a) When the coil 68 is de-energized, the fuel flow path 250 and the fuel discharge flow path 252 communicate with each other regardless of the position of the rod 132 in the rotational direction, so excess fuel in the metering valve 40 is discharged. be able to. Therefore, it is not necessary to process the rod 132 or the movable core 54 to prevent the rotation of the movable portion 130 .

[5. Fifth Embodiment]
[5-1. Differences from First Embodiment]
Since the basic configuration of the fifth embodiment is the same as that of the first embodiment, differences will be described below. Note that the same reference numerals as in the first embodiment indicate the same configurations, and refer to the preceding description.

In the first embodiment described above, the flow area of the fuel discharge flow path 218 formed in the valve body 56 is defined by the inside of the valve body 56 and the opening on the inner peripheral surface side of the valve body 56 that is opened and closed by the rod 52 . It is the same with the department.

In contrast, in the fifth embodiment, as shown in FIGS. 19 and 20, the flow area of the fuel discharge flow path 260 formed inside the valve body that reciprocally supports the rod 140 is larger than the flow area of the fuel discharge flow path 260. The passage area of an opening 262 where the discharge passage 260 opens toward the inner peripheral surface of the valve body is large.

The amount of movement of the rod 140 in the reciprocating direction when switching ON/OFF of the energization of the coil 68 is the same as that of the rod 52 of the first embodiment.
When coil 68 is de-energized, rod 140 is in the position shown in solid lines in FIGS. When the coil 68 is not energized, S1 is the flow area of the actual opening 262a of the opening 262 that is not covered with the rod 140, and S2 is the flow area of the fuel discharge flow path 260. Then, S1≦S2. be. Further, if the flow channel area of the fuel discharge flow channel 218 of the first embodiment is S0, then S0<S1.

The length of the opening 262 in the direction intersecting the reciprocating direction of the rod 140 is set to satisfy S0<S1≦S2.
When the coil 68 is not energized, the channel area of the actual opening 262a is smaller than the channel area of the fuel discharge channel 260, so the flow rate of fuel flowing through the actual opening 262a and the fuel discharge channel 260 is It is determined by the channel area of the actual opening 262a. The channel area of the actual opening 262a is also referred to as the minimum channel area.

As shown in FIG. 21, the minimum channel area 410 when the coil 68 is not energized is larger than the channel area 400 of the fuel discharge channel 218 in the first embodiment, so the metering in the fifth embodiment The amount of surplus fuel discharged from the valve is greater than the amount of surplus fuel discharged from the metering valve in the first embodiment.

When the coil 68 is energized, the rod 140 moves together with the movable core 54 to the position indicated by the two-dot chain lines in FIGS. In this case, since the opening 262 is covered and closed by the rod 140 , excess fuel in the metering valve is not discharged from the fuel discharge passage 260 .

Further, in the fifth embodiment, when the coil 68 is not energized, the flow area of the actual opening 262a of the fuel discharge flow path 260 is the same as that of the opening of the fuel discharge flow path 218 of the first embodiment. larger than area. Therefore, when duty control is performed instead of ON/OFF of the energization of the coil 68, it is easy to variably control the passage area according to the duty, as indicated by the characteristic 412 in FIG.

In the fifth embodiment, the fuel discharge channel 260 corresponds to a fuel channel having different inlets and outlets for discharging surplus fuel of the metering valve.
[5-2. effect]
According to the fifth embodiment described above, in the effects (1a) to (1d) of the first embodiment described above, the fuel flow path having different inlets and outlets for discharging surplus fuel is replaced by the fuel discharge flow path 260. You can get the effect of replacing the

Furthermore, according to the fifth embodiment, the following effects can be obtained.
(5a) When the coil 68 is de-energized, the flow passage area 410 of the fuel flow passage for discharging surplus fuel in the fifth embodiment is the flow passage area 410 of the fuel flow passage for discharging surplus fuel in the first embodiment. Greater than 400. Therefore, if the moving amount of the rod of the movable portion in the reciprocating direction is the same, in the fifth embodiment, more surplus fuel can be discharged from the fuel discharge passage 260 than in the first embodiment.

(5b) When energization of the coil 68 is duty-controlled, the discharge amount of surplus fuel discharged from the fuel discharge passage 260 per unit time can be easily variably controlled by duty control.

[6. Sixth Embodiment]
[6-1. Differences from the Fifth Embodiment]
Since the sixth embodiment has the same basic configuration as the fifth embodiment, differences will be described below. The same reference numerals as in the fifth embodiment indicate the same configurations, and the preceding description is referred to.

In the fifth embodiment described above, when the coil 68 is energized, the opening 262 is covered and closed by the rod 140, so that excess fuel in the metering valve is not discharged from the fuel discharge passage 260.

In contrast, in the sixth embodiment shown in FIG. 23, when the coil 68 is energized, the actual opening 262b, which is a part of the opening 262 of the fuel discharge passage 260, is covered with the rod 140. not open and not closed. Therefore, even if the coil 68 is energized, the surplus fuel in the metering valve is discharged through the fuel discharge passage 260 from the actual opening 262b.
In this case, as indicated by the minimum flow area 420 in FIG. 24, the actual opening 262b when the coil 68 is energized functions as an orifice that throttles the flow path of the fuel discharge flow path 260. FIG.

Further, in the sixth embodiment, the flow path area S0 of the fuel discharge flow path 218 of the first embodiment, the flow path area S1 of the actual opening 262a of the opening 262 when the coil 68 is not energized, The relationship with the channel area S2 of the fuel discharge channel 260 is S0<S1≦S2, as in the fifth embodiment. Therefore, when duty-controlling the energization of the coil 68, it is easy to variably control the passage area according to the duty, as indicated by the characteristic 422 in FIG.

[6-2. effect]
According to the sixth embodiment described above, the following effects can be obtained in addition to the effects of the fifth embodiment described above.

(6a) Since the actual opening 262b when the coil 68 is energized functions as an orifice that narrows the flow path of the fuel discharge flow path 260, the orifice 22 shown in FIG. 1 in the first embodiment is eliminated. be able to.

[7. Seventh embodiment]
[7-1. Differences from the Fifth Embodiment]
Since the seventh embodiment has the same basic configuration as the fifth embodiment, differences will be described below. The same reference numerals as in the fifth embodiment indicate the same configurations, and the preceding description is referred to.

In the fifth embodiment described above, the opening 262 of the fuel discharge passage 260 that opens to the inner peripheral surface of the valve body is formed in a rectangular shape.
In contrast, in the seventh embodiment shown in FIG. 26, the rod 140 moves toward the fixed core side 66 together with the movable core 54 at the opening 272 where the fuel discharge passage 270 opens toward the inner peripheral surface of the valve body. It is formed in a trapezoidal shape that tapers as it goes.

In the seventh embodiment, the flow area S0 of the fuel discharge flow path 218 of the first embodiment, the flow area S1 of the actual opening 272a of the opening 272 when the coil 68 is not energized, and the fuel discharge The relationship between the channel area S2 of the channel 270 is S0<S1≦S2.

With such a configuration, as shown in FIG. 27, in the characteristic 430 of the seventh embodiment that indicates the relationship between the duty for controlling the energization of the coil 68 and the minimum flow path area, the characteristic 412 of the fifth embodiment is different from the characteristic 412 of the fifth embodiment. As the duty for energization control of 68 increases from 0% to 100% and the minimum flow path area becomes smaller, the reduction rate of the minimum flow path area decreases.

On the other hand, in the case of the above-described fifth embodiment, even if the duty for controlling the energization of the coil 68 increases from 0% to 100%, the decrease rate of the flow passage area is constant as shown in the characteristic 412 shown in FIG. is.

In the seventh embodiment, the fuel discharge channel 270 corresponds to a fuel channel having different inlets and outlets for discharging surplus fuel of the metering valve.
[7-2. effect]
According to the seventh embodiment described above, it is possible to obtain the effect of replacing the fuel discharge channel 260 with the fuel discharge channel 270 in the effect of the fifth embodiment described above.

Furthermore, according to the seventh embodiment, the following effects can be obtained.
(7a) As the duty for controlling the energization of the coil 68 increases from 0% to 100% and the minimum flow path area decreases, the rate of decrease in the minimum flow path area decreases. When the discharge amount of surplus fuel is small, the discharge amount of surplus fuel can be duty-controlled with high accuracy.

[8. Eighth Embodiment]
[8-1. Differences from the seventh embodiment]
The basic configuration of the eighth embodiment is the same as that of the seventh embodiment, so differences will be described below. Note that the same reference numerals as in the seventh embodiment indicate the same configurations, and refer to the preceding description.

In the above-described seventh embodiment, the opening 272 where the fuel discharge passage 270 opens toward the inner peripheral surface of the valve body tapers as the rod 140 moves toward the fixed core 66 together with the movable core 54. formed into a shape.

On the other hand, in the eighth embodiment shown in FIG. 28, the rod 140 moves toward the fixed core side 66 together with the movable core 54 at the opening 282 where the fuel discharge passage 280 opens toward the inner peripheral surface side of the valve body. It is formed in a trapezoidal shape that becomes thicker as the tip increases.

In the eighth embodiment, the flow area S0 of the fuel discharge flow path 218 of the first embodiment, the flow area S1 of the actual opening 282a of the opening 282 when the coil 68 is not energized, and the fuel discharge The relationship between the channel area S2 of the channel 280 is S0<S1≦S2.

With such a configuration, as shown in FIG. 29, a characteristic 440 of the eighth embodiment, which indicates the relationship between the duty for controlling the energization of the coil 68 and the minimum flow path area, is different from the characteristic 412 of the fifth embodiment. decreases from 100% to 0%, and as the minimum flow area increases, the rate of increase in the minimum flow area decreases.

In the eighth embodiment, the fuel discharge channel 280 corresponds to a fuel channel having different inlets and outlets for discharging surplus fuel of the metering valve.
[8-2. effect]
According to the eighth embodiment described above, the effect of replacing the fuel discharge channel 260 with the fuel discharge channel 280 can be obtained in the effect of the fifth embodiment described above.

Furthermore, according to the eighth embodiment, the following effects can be obtained.
(8a) As the duty for energizing and controlling the coil 68 decreases from 100% to 0% and the minimum flow path area increases, the rate of increase in the minimum flow path area decreases. When the discharge amount of excess fuel is large, the discharge amount of surplus fuel can be duty-controlled with high accuracy.

[9. Other embodiments]
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications can be made.

(9a) In the above embodiment, by controlling the energization of the coil 68, the reciprocating position of the movable portion of the metering valve is changed to control the flow rate of the surplus fuel discharged from the metering valve.
On the other hand, if the metering valve has a fuel flow path that passes through at least one of the outside and the inside of the movable part and has different inlets and outlets for discharging surplus fuel, the metering valve can be used. Excess fuel in the metering valve may be discharged from the fuel flow path regardless of the reciprocating position of the movable portion.

(9b) In the above-described embodiment, the movable portion and the valve member of the metering valve are composed of separate members, and the movable portion and the valve member can move separately. On the other hand, by changing the reciprocating position of the movable part of the metering valve, the flow rate of the surplus fuel discharged from the metering valve can be simply opened and closed by opening and closing the fuel passage for discharging the surplus fuel. The movable portion of the metering valve and the valve member may be configured to reciprocate integrally as long as they can be controlled inclusive.

(9c) In the above-described first to fifth, seventh, and eighth embodiments, when the coil 68 is de-energized, the excess fuel is discharged from the metering valve, and the coil 68 is discharged. When the energization is on, the configuration is such that surplus fuel is not discharged from the metering valve.

On the other hand, depending on the relationship between the reciprocating position of the movable part and the position of the opening of the fuel discharge passage opened and closed by the movable part, when the coil 68 is energized, the excess fuel is discharged from the metering valve. However, when the coil 68 is de-energized, the excess fuel may not be discharged from the metering valve.

(9d) In the above embodiment, a fuel flow path is formed through either the outside or the inside of the movable portion to discharge excess fuel from the metering valve.
On the other hand, a fuel flow path may be formed through both the outside and the inside of the movable portion to discharge excess fuel from the metering valve.

(9e) In the above embodiment, the coil 68 is used as the driving portion for reciprocatingly driving the movable portion. On the other hand, when switching between discharging and not discharging the excess fuel from the metering valve by turning on and off the energization, a piezoelectric element may be used as the drive section.

(9f) A plurality of functions possessed by one component in the above embodiments may be realized by a plurality of components, or a function possessed by one component may be realized by a plurality of components. . Moreover, a plurality of functions possessed by a plurality of components may be realized by a single component, or a function realized by a plurality of components may be realized by a single component. Also, part of the configuration of the above embodiment may be omitted. Also, at least part of the configuration of the above embodiment may be added or replaced with respect to the configuration of the other above embodiment.

(9g) In addition to the metering device described above, the present disclosure can also be implemented in various forms, such as a system having the metering device as a component.

2: fuel injection system, 20: fuel injection pump, 34: plunger, 40, 80, 110: metering valve (metering device), 42a: valve seat, 44: valve member, 50, 90, 120, 130: movable Part 52, 92, 122, 132, 140: Rod (movable part) 54: Movable core (movable part): 68: Coil (drive part) 100: ECU (control part, metering device) 206: Addition Pressure chambers 214, 250: fuel flow path 216, 222, 232: communication path (fuel flow path) 218, 230, 240, 252, 254, 260, 270, 280: fuel discharge flow path (fuel flow path)

Claims (7)

A metering device (40, 80, 110) for metering a fuel flow rate pumped from a fuel injection pump (20),
a valve seat (42a);
By leaving the valve seat, fuel is sucked into the pressurization chamber (206) in a suction stroke in which the plunger (34) moves in a direction opposite to the direction in which the fuel in the pressurization chamber (206) is pressurized. a valve member (44) that pressurizes and pumps the fuel in the pressurization chamber (44) by being pressurized by the plunger by being seated on the valve seat in a pumping stroke in which the moves in the pressurizing direction;
a drive (68);
A movable portion (50) that changes its position by controlling the energization of the driving portion, and switches whether the valve member is seated on the valve seat or separated from the valve seat by changing the position. , 90, 120, 130, 140) and
Fuel passages (214 to 218, 222, 230, 232, 240, 250 to 254, 260, 270) that pass through at least one of the inside and outside of the movable portion and have different inlets and outlets for discharging surplus fuel. , 280) and
with
The valve member and the movable portion are separate members, and the movable portion moves the valve member to the valve seat when the driving portion is energized in both the suction stroke and the pumping stroke. The valve member moves in a seating direction, and when the drive unit is deenergized, the valve member moves in a direction away from the valve seat.
metering device. A metering device according to claim 1,
The amount of surplus fuel discharged through the fuel channel is controlled by changing the position of the movable part.
metering device. A metering device according to claim 1 or 2 ,
With respect to the position of the movable portion, the energization of the driving portion is controlled in both the state in which the valve member is seated on the valve seat and the state in which the valve member is separated from the valve seat. change by being
metering device. A metering device according to any one of claims 1 to 3 ,
The valve member is seated on the valve seat by the movement of the movable portion when the drive portion is energized during the pumping stroke, and the valve member is seated on the valve seat during the intake stroke regardless of the position of the movable portion. leave one's seat,
metering device. A metering device according to any one of claims 1 to 4 ,
When the valve member is seated on the valve seat during the pumping stroke, the valve member remains seated on the valve seat until the suction stroke starts, regardless of control of energization of the drive unit.
metering device. A metering device according to any one of claims 1 to 5 ,
A channel area of the fuel channel changes according to a position of the movable part,
metering device. A metering device according to any one of claims 1 to 6 ,
further comprising a control unit (100) for controlling energization of the driving unit;
The control section controls the energization of the drive section during at least one of the intake stroke and the pumping stroke to change the position of the movable section without changing the position of the valve member. change,
metering device.

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