JP2002266727A - Fuel control valve and high pressure fuel pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high pressure fuel pump having excellent responsiveness, and capable of following control with high accuracy. SOLUTION: This high pressure fuel pump comprises a discharge amount control valve 100 for feeding fuel discharged by reciprocally sliding a plunger 111 inserted in a pump chamber 110a by opening/closing a spill port 153a with a seat valve portion 150. A discharge amount control valve comprises a movable element portion 140a electromagnetically control the opening/closing of the spill port by the seat valve portion, a stem portion 140b for mediating an energizing force in the seat removing direction of the seat valve portion by a movable element portion, and a hollow portion 140c formed on at least either one of the seat valve portion, the movable element portion and the stem portion, and sealing gas inside thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel control valve used for controlling the amount and timing of supply of fuel to an engine, a gasoline engine and a diesel engine for directly injecting fuel into a cylinder for combustion. The present invention relates to a high-pressure fuel pump used for an engine.

[0002]

2. Description of the Related Art In recent years, gasoline engines and diesel engines are required to satisfy strict exhaust gas regulations in addition to high output, low noise, and low fuel consumption. Must be controlled.
Therefore, a fuel control valve using an electromagnetic valve is used for controlling the fuel injection amount and injection timing by the injector, controlling the discharge amount by the high-pressure fuel pump, and the like. By controlling the opening and closing of the port using an electromagnetic valve, high-precision and fine control is possible. There are various types of fuel control valves using this solenoid valve. There are a direct drive type and a pilot type depending on the drive type, and there are an inner open valve and an outer open valve depending on the opening and closing direction of the valve. For example, JP-A-8-49617 and JP-A-11-223
No. 272 discloses a pilot-type inner valve.

[0003] Here, the "direct-acting type" is a valve in which a seat valve portion abutting on a valve seat of a port and a driving portion thereof (movable element of an electromagnetic valve) are integrally operated, and a "pilot type". Is a valve in which the seat valve portion and the driving portion are separated, and a hydraulic operating chamber and a stem portion (shaft portion) are provided between the two and the seat valve portion is indirectly driven by the driving portion. is there. Also,
“Internal opening” is a valve in which the valve seat (seat surface) of the port is on the drive side (inside) and the seat valve portion opens inward. The valve is located on the opposite side (outside) of the driving unit, and the seat valve unit opens outward. These terms are used interchangeably below.

[0004]

By the way, recent fuel control has become more sophisticated and precise, and the fuel control valve must be able to follow the control.
However, in the electromagnetic spill valve (20) disclosed in JP-A-8-49617, since the needle valve (4), the armature (6), etc., which are movable parts, are made of iron solids, their inertia are reduced. The mass becomes very large. Therefore, in the electromagnetic spill valve (20), the responsiveness of the movable part is poor, and it is difficult to follow the control with high accuracy. The reference numerals in parentheses refer to the reference numerals shown in FIG. 1 of the publication.

In the solenoid valve disclosed in Japanese Patent Application Laid-Open No. 11-223272, a plunger (200) serving as a movable portion has a stepped shaft hole (202, 210) and a lateral hole (220) communicating therewith. It is considered that the inertia mass is reduced accordingly. However, this solenoid valve is a refrigerant switching valve, and the shaft holes (202, 210) and the side holes (220) are communication paths for the refrigerant. If the structure is used as it is for a fuel control valve, the hole is filled with fuel, and the mass of the fuel is newly added as an inertial mass. Therefore, even if such a valve structure is employed, the inertial mass cannot be sufficiently reduced.
The reference numerals in parentheses refer to the reference numerals shown in FIG. 1 of the publication.

By the way, if the fuel control valve is a direct acting type,
Since the seat valve section and the drive section (movable element section) operate integrally, it is difficult to reduce the inertial mass. In addition, since strict processing accuracy such as coaxiality is required for each part, the cost of the fuel control valve increases. When the fuel control valve is opened internally,
For example, when a large fuel pressure acts on a seat valve portion (a needle valve or the like) from the outside, the driving portion needs to be provided with a structure that opposes the large acting force, and it is inevitable to increase the size of the fuel control valve.

[0007] The present invention has been made in view of such circumstances. In other words, assuming a pilot type external valve that is relatively responsive and can be miniaturized at low cost,
It is an object of the present invention to provide a fuel control valve which is further improved in responsiveness and has excellent controllability capable of following high-precision control. Another object of the present invention is to provide a high-pressure fuel pump in which the fuel control valve is applied to a discharge control valve.

[0008]

[Means for Solving the Problems] (Fuel Control Valve)
The present inventor has conducted intensive research to solve this problem, and as a result of repeated trial and error, assuming that it is a pilot-type open valve, at least one of a seat valve portion, a mover portion, and a stem portion, The inventors came up with the idea of providing a hollow section in which gas was sealed, and completed the fuel control valve of the present invention. That is, as described in claim 1, the fuel control valve of the present invention includes a port interposed in the fuel passage and having a valve seat around the port, the port being biased in the seating direction on the valve seat, and the valve seat being A seat valve portion that opens and closes the port by detaching and seating between the seat valve portion and a seat valve portion that is provided separately from the seat valve portion on the opposite side of the seat valve portion with respect to the port and opens and closes the port by the seat valve portion. A fuel control valve, comprising: a mover portion that is electromagnetically controlled; and a stem portion that mediates an urging force of the mover portion in a seating direction of the seat valve portion from the mover portion to the seat valve portion. At least one of the seat valve portion, the mover portion, and the stem portion includes a hollow portion in which gas is sealed.

Since the fuel control valve according to the present invention is a pilot valve in which a seat valve portion and a mover portion are separated, a port is opened and closed by the seat valve portion via a stem portion interposed therebetween. Is done. The fuel control valve is also an externally opened valve in which a mover section is provided on the port on the opposite side of the seat valve section. For example, when the port is opened, the stem portion contacts the mover portion or the seat valve portion, and the urging force is transmitted from the mover portion to the seat valve portion via the stem portion,
The port is opened when the seat valve part is separated from the valve seat of the port. The driving by the mover, the transmission of the urging force by the stem, and the opening and closing of the port by the seat valve are performed at very high speed. Then, the acceleration of each member (or each portion) also suddenly changes cyclically, and an inertial force corresponding to the acceleration and the inertial mass acts on each member.

However, in the fuel control valve of the present invention, since at least one of the seat valve portion, the mover portion and the stem portion has a hollow portion in which gas is sealed, the inertial mass is reduced, that is, the responsiveness is reduced. Can be reliably improved. In addition,
Needless to say, the more hollow parts are provided in a plurality of members (for example, the hollow parts are provided in the mover part and the stem part),
The larger the volume of the hollow portion, the more preferable from the viewpoint of reducing the inertial mass. However, the shape and volume of the hollow
It is appropriately determined in consideration of the size of the fuel control valve, the rigidity required for each member, and the differential force described below.
The gas is sealed in the hollow portion because the inertial mass of the gas can be substantially ignored. The type and pressure of the gas are not limited, but air that can reduce the cost is usually suitable. The hollow portion, for example, a bottomed cylindrical internal space is bored in a stem portion or the like, and a lid member is hermetically sealed at an end opening, and caulked,
It is formed by welding, press-fitting and the like.

Incidentally, since the mover portion, the seat valve portion, and the stem portion are normally immersed in the fuel, buoyancy acts on each of these members in accordance with the fuel density and the displacement volume. A force corresponding to the difference between the buoyancy and the gravity acting on each member (hereinafter, referred to as a “differential force”) acts vertically upward or vertically downward on each member. If the direction of the differential force is effectively used by devising the arrangement position of the fuel control valve, the responsiveness of the fuel control valve can be further improved. For example, in order to improve the valve closing response of the seat valve portion, the seating direction of the seat valve portion on the port and the direction of the differential force may be matched. When each member does not have a hollow portion as in the related art, the ratio of gravity is overwhelmingly large, and a differential force acts only vertically downward, so that the responsiveness of each member may differ depending on the operation direction. Further, in order to cancel the gravity, it is necessary to adjust the urging force using an elastic body or the like having a large spring constant.
On the other hand, when a hollow portion is provided in a stem portion or the like as in the present invention, the proportion of gravity offset by buoyancy increases, and the differential force acting on each member decreases. Therefore, a difference in responsiveness depending on the operation direction can be suppressed, and the spring constant of the elastic body used can be reduced.

However, for example, in some cases, only the valve-closing response or only the valve-opening response of the seat valve portion needs to be improved. In such a case, the volume of the hollow portion may be adjusted to match the direction of the differential force with the direction of the seating of the seat valve. In particular, this method is effective when the arrangement position of the fuel control valve cannot be freely changed. Incidentally, since the fuel control valve of the present invention is a pilot-type open valve, the seat valve portion and the mover portion are separated from each other, but the stem portion may be integrated with either one of them. good. For example, the stem portion and the mover portion may be integrated, or the stem portion and the seat valve portion may be integrated. Of course, it is also possible to support the stem portion with an appropriate guide portion and make them have a three-part structure.

Needless to say, when closing the port with the seat valve, it is necessary that the seat valve does not abut on the stem. Therefore, the displacement amount (L
It is necessary to set the length of the stem portion so that 1) is larger than the displacement amount (L2) of the seat valve portion (L1> L2). Further, the urging of the seat valve portion in the seating direction and the urging of the seat valve portion in the separating direction by the mover portion can be performed by an elastic body such as a coil spring or a disc spring. Although it is conceivable to perform such biasing with an electromagnetic force, the cost and size of the fuel control valve can be reduced by using an elastic body. For example, it is preferable that the mover part elastically urges the stem part in the direction in which the seat valve part is unseated, and releases the elastic urging by applying an electromagnetic force.

(High-Pressure Fuel Pump) Further, the present inventor:
The present inventors have conceived of using the above-mentioned fuel control valve as a discharge control valve of a high-pressure fuel pump for supplying high-pressure fuel to a direct injection gasoline engine or a diesel engine, and have completed the high-pressure fuel pump of the present invention. That is, the high-pressure fuel pump according to the present invention is configured such that the low-pressure fuel passage communicating with the low-pressure fuel supply source and the high-pressure fuel passage supplying the high-pressure fuel to the injector side can communicate with each other. A pump body having a chamber, a plunger fitted into the pump chamber, receiving a driving force from a driving source, and reciprocatingly sliding in the pump chamber to suck and discharge fuel, and a fuel pipe communicating with the pump chamber. A discharge amount control valve that adjusts a discharge amount of the high-pressure fuel to the high-pressure fuel passage by opening and closing a spill port provided in the overflow passage, wherein the discharge amount control valve includes the spill port. A valve body having a working chamber formed on the opposite side of the pump chamber with respect to the port and communicating with the overflow passage;
A seat valve portion urged in a seating direction to a valve seat formed on the pump chamber side of the spill port and opening and closing the spill port by separating from and seating on the valve seat; A mover unit that is disposed in the working chamber separately from the unit and electromagnetically controls opening and closing of the spill port by the seat valve unit;
A stem portion for mediating the urging force of the mover portion in the seating direction of the seat valve portion from the mover portion to the seat valve portion, and at least one of the seat valve portion, the mover portion, and the stem portion; And a hollow portion in which a gas is sealed inside.

A pilot-type open valve in which a seat valve portion and a mover portion are separated from each other is employed, and a gas-filled hollow portion is provided in at least one of the seat valve portion, the mover portion, and the stem portion which are movable portions. Therefore, a discharge amount control valve having excellent responsiveness was obtained, and controllability of the high-pressure fuel pump was improved. Incidentally, it is preferable that the working chamber constitutes at least a part of a fuel reservoir communicating with the low-pressure fuel passage, and the spill port also serves as a suction port of the low-pressure fuel to the pump chamber. . Thus, the low-pressure fuel passage can be simplified, and the high-pressure fuel pump can be downsized. Further, since the spill port also serves as the suction port, a force corresponding to the movement of the plunger acts on the seat valve disposed therein, and the responsiveness of the seat valve further improves. For example, if the plunger is in the suction stroke (down stroke),
Negative pressure acts on the plunger side of the seat valve, and the seat valve operates in a direction to open its suction port. Conversely, when the plunger is in the discharge stroke (up stroke), a positive pressure acts on the plunger side of the seat valve, and the seat valve operates in a direction to close its suction port. Thus, both the valve opening response and the valve closing response of the seat valve portion are improved.

Further, it is preferable that the stem portion provided in the working chamber is thinner than the mover portion. When the stem portion is thinner than the mover portion, the volume (V) of the space formed in the working chamber increases accordingly. Then, even if the mover section operates in this working chamber to cause a change in volume (ΔV), the rate of change in volume (ΔV / V) is observed in the entire working chamber.
Is relatively small, and the pressure fluctuation (pressure pulsation) accompanying the operation of the mover section is also small. Therefore, the variability of the response of the seat valve due to the pressure pulsation is reduced, and the controllability of the discharge amount control valve can be improved. In this case, the shape of the stem portion may be, for example, a column-shaped stem portion having a smaller diameter than that of the movable portion when a large-diameter movable portion is fitted into a cylindrical working chamber.

Preferably, a spherical contact portion is provided between the stem portion and the seat valve portion or the mover portion. Thus, even if any one of the seat valve portion, the stem portion, and the mover portion is slightly inclined during operation, the contact relationship between the stem portion and the seat valve portion or the mover portion is affected by the inclination. It is stable with little reception and no unexpected moment is applied. Therefore, it is possible to suppress variations in the displacement amount of the seat valve portion and deterioration in responsiveness. Further, since a slight inclination of the mover portion and the like can be tolerated, strict processing accuracy and the like are not required for each portion, and a fuel control valve having excellent controllability can be obtained at low cost. The spherical contact portion does not need to be a true spherical shape, and a spherical curved surface enough to stabilize the displacement and responsiveness of the seat valve portion in consideration of the clearance between the guides of each portion and the like is used as the spherical contact portion. Good to have.

The pump body and the valve body may be separated or integrated. Also,
The discharge amount control valve varies the discharge amount of the fuel in order to adjust the fuel pressure in the delivery pipe such as a common rail, but may also adjust the discharge timing. In addition, the matters described regarding the fuel control valve can be appropriately applied to the discharge amount control valve. The engine using this high-pressure fuel pump is not limited to a direct injection gasoline engine or a direct injection diesel engine.
Further, the present invention is not limited to the common rail type. For example, in the case of a diesel engine, a vortex chamber type or a pre-combustion chamber type may be used in addition to the direct injection type. Further, the present invention can be applied to a high-pressure fuel pump in which a conventional line-type or distribution-type fuel injection pump is electronically controlled.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described more specifically with reference to the embodiments related to a high-pressure fuel pump having a discharge control valve, which is one embodiment of a fuel control valve. FIG. 1 shows a fuel system using the high-pressure fuel pump P according to the present invention. As you can see from this figure, Engine 1
The injector 2 is disposed in the combustion chamber of each cylinder of the above. The fuel injection from the injector 2 to the engine 1 is performed as follows.
It is controlled by ON / OFF of the injection control solenoid valve 3. The engine 1 may be a gasoline engine or a diesel engine.

The injector 2 is connected to a common rail 4 which is a high-pressure accumulating pipe common to each cylinder. While the injection control solenoid valve 3 is open, fuel in the common rail 4 is injected from the injector 2 to the engine 1. Is done. It is necessary to store a stable high fuel injection pressure in the common rail 4. Therefore, the variable discharge amount high-pressure fuel pump P pressurizes the fuel pumped from the fuel tank 8 by the known low-pressure pump 9 to a high pressure and controls the discharge amount.
The fuel is supplied to the common rail 4 via the delivery valve 20 and the delivery pipe 5, and the fuel in the common rail 4 is maintained at a predetermined high pressure. The detailed structure of the high-pressure fuel pump P will be described later.

This fuel system includes an electronic control unit E
It is controlled by the CU 11. Electronic control unit ECU1
Reference numeral 1 denotes an input of an engine speed signal, a load information signal, and the like from an engine speed sensor 41, a load sensor 42, and the like, and based on these signals, an optimum injection timing and injection amount (injection period) according to an engine state. To calculate the injection amount control solenoid valve 3
To output a control signal. At the same time, the ECU 11 outputs a control signal to the electromagnetic drive unit 130 of the high-pressure fuel pump P described later so that the injection pressure of the injector 2 becomes an optimum value. That is, the ECU 11 receives the fuel pressure signal input from the pressure sensor 43 provided on the common rail 4, and controls the high-pressure fuel so that the fuel pressure becomes an optimal value set in advance according to the load, the rotation speed, and the like of the engine 1. The discharge amount of the pump P is controlled by a discharge amount control valve.

Incidentally, the basic structure of such a high-pressure fuel pump P is known, but the high-pressure fuel pump P of the present embodiment has a discharge amount control valve which is not available in the past. Therefore, the discharge amount control valve 10 according to the first embodiment is described.
0 will be described with reference to FIG. The discharge amount control valve 100 includes a pump body 110, a valve body 120, and the electromagnetic drive unit 1.
The main configuration includes the lifter 30, the lifter 140, and the seat valve 150. The pump body 110 has a cylindrical pump chamber 11.
The pump chamber 110a has a plunger 111 fitted therein. Then, the volume of the pump chamber 110a changes due to the vertical reciprocation of the plunger 111, and the suction and discharge of fuel are performed. The plunger 111 is driven up and down by a cam (not shown) driven by the engine 1. The pump chamber 110a communicates with a high-pressure fuel passage 110b, and high-pressure fuel is pressure-fed from the high-pressure fuel passage 110b to the delivery valve 20, the delivery pipe 5, the common rail 4, and the injector 2. Further, the pump body 11
A valve storage chamber 110c having a diameter larger than that of the pump chamber 110a is formed in the upper part (on the figure) of the pump chamber 110.
a.

A substantially cylindrical stepped valve housing 153 forming a spill port 153a is fitted into the valve storage chamber 110c. Valve housing 153
Is provided with a disk-shaped seat valve 150 therein, and an annular valve seat 153b on which the seat valve 150 is seated is connected to the spill port 1.
53a. And, the seat valve 150
The opening and closing of the spill port 153a is performed by the seating of the valve seat 153b and the seat surface of the spill port 153b. On the inner peripheral side of the valve housing 153, a seat valve 150 is provided with a valve seat 153.
A disc spring 151 for urging in the direction b (seating direction) and a substantially cylindrical stepped holding member 152 that supports the disc spring 151 and serves as a seat for the seat valve 150 are fitted and inserted. In addition, the seat valve 150 corresponds to the seat valve portion in the present invention. A small notch 150 is provided on the outer periphery of the seat valve 150.
are provided, and a comb-shaped notch 152a is also provided in the upper portion of the holding member 152, and fuel is supplied from the spill port 153a to the pump chamber 110a through the notch.
It is designed to communicate with

The valve body 120 has a concave recess at its lower portion, and forms a fuel reservoir 120c with the upper surface (in the figure) of the pump body 110. The valve body 120 and the pump body 110 are firmly connected by bolts (not shown) with a seal member 121 interposed therebetween.
0c is oil-tight. The fuel reservoir 120c communicates with the low-pressure fuel passage 120b. The low-pressure fuel is supplied from a low-pressure pump 9 such as a feed pump, and the overflowed low-pressure fuel is returned to the fuel tank 8 through the low-pressure pump 9. Further, the valve body 120 has an opening at an upper portion, a cylindrical valve case 154 is inserted into the opening, and an oil-tight state is provided between the valve body 120 and the valve body 120 by a seal member 125. Further, a cylindrical iron core 133 of the electromagnetic drive unit 130 is provided in an upper opening of the valve case 154.
In this embodiment, the working chamber 120a is defined by the valve case 154 and the iron core 133.

Inside the working chamber 120a, a columnar movable part 140a and a movable part
A lifter 140 including a stem portion 140b extending in the zero direction is provided. The mover portion 140a fitted in the valve case 154 slides back and forth inside the valve case 154 using the valve case 154 as a guide. The lifter 140 has a mover portion and a stem portion integrated with each other, and has a bottomed cylindrical hollow portion 140c from near the upper end portion of the mover portion 140a to near the lower end portion of the stem portion 140b.
Inside. This hollow portion 140c is
Ob can be formed by drilling from the lower end side of Ob to near the upper end of the mover section 140a, and closing the lower end opening with a cover member 144 made of steel balls. Since this processing is performed in the atmosphere, the inside is naturally filled with air. In addition,
The closure by the lid member 144 was performed by uniformly crimping the outer periphery. However, in order to further improve the airtightness, the periphery may be laser-welded. Further, by using a hard and low-cost steel ball for the lid member 144, it is possible to improve the wear resistance with the seat valve 150 and reduce the cost. Further, the lid member 144
Is a spherical contact portion interposed between the stem portion 140b and the seat valve 150. Therefore, even when an inexpensive press-processed product is used for the valve case 154, the contact portion between the stem portion 140b and the seat valve 150 is formed. The contact relationship can be stabilized. In addition, it is possible to suppress the variation of the displacement and the responsiveness of the seat valve 150.

The electromagnetic drive unit 130 includes a solenoid coil 13 housed in a frame 132 and disposed around an iron core 133.
1 and a connector 1 containing an electric wire 134 for supplying a control signal (electric power) from the ECU 11 to the solenoid coil 131.
35. At the lower end of the iron core 133, a bottomed cylindrical spring chamber 133a is formed, in which a coil spring 143 is disposed. The coil spring 143 urges the lifter 140 toward the seat valve 150 (seating direction) with the bottom surface of the spring chamber 133a and the upper surface of the mover portion 140a as spring seat surfaces. In the present embodiment, the urging force (F1) of the seat valve 150 is controlled by the coil spring 143.
The urging force (F2) of the seat valve 150 by the disc spring 151 is set to be larger (F1> F2). Therefore, when no electromagnetic force is applied to the mover section 140a from the electromagnetic drive section 130, the seat valve 150 is biased in the unseating direction. However, unlike the conventional lifter, the lifter 140 of the present embodiment has a hollow portion 140c, so that a differential force (f) is generated vertically upward (upward in the figure). Therefore, the differential force f
In consideration of this, the urging force F2 may be set smaller than in the related art (F1> F2 + f).

When the solenoid coil 131 is energized, a magnetic circuit is formed, the movable member 140a made of a magnetic material is sucked to the iron core 133, and the urging force of the lifter 140 to the seat valve 150 is released. By this switching of the energization, the opening and closing of the spill port 153a by the seat valve 150 is switched, and further, the discharge amount of the high-pressure fuel is adjusted. For example, a plunger 11 as shown in FIG.
Consider a case in which the solenoid coil 131 is energized for a time T2 after a lapse of a predetermined time T1 from the detection of the reference position of the cam serving as the drive source of the plunger 111 in the ascent stroke 1. When power is not supplied, the spill port 15
3a is open, and the fuel in the pump chamber 110a returns to the low-pressure fuel passage 120b from the spill port 153a,
No fuel is discharged to the high-pressure fuel passage 110b. On the other hand, when the solenoid coil 131 is energized, the spill port 1
During a period from the closing of 53a to the top dead center of the plunger 111 (lift H1), the fuel in the pump chamber 110a (the fuel corresponding to the hatched portion in FIG.
b. Thus, the solenoid coil 1
The pre-stroke amount by the plunger 111 can be adjusted by adjusting the energization timing (time T1) to the 31 and the discharge amount (fuel pressure in the common rail 4) to the high-pressure fuel passage 110b and the discharge timing can be controlled. The energization timing and energization time are determined by the ECU 11 based on the injection amount of the injector 2, the engine speed, and the like, or by comparison with a preset map.

In this embodiment, since the discharge amount control valve 100 is a pilot-type open valve, for example, as shown in FIG. 3B, the energizing time of the solenoid coil 131 is reduced from time T2 to time T3. You can also.
The time T3 is a response time T required to close the seat valve 150.
This is set slightly larger than 0. This is for the following reason. When the energization of the solenoid coil 131 is started during the rising stroke of the plunger 111, the lifter 140 is attracted to the iron core 133, and no urging force acts on the seat valve 150 in the unseating direction. Then, since the plunger 111 is in the upward stroke, positive pressure acts on the seat valve 150 from the pump chamber 110a side, and the seat valve 150 immediately closes the spill port 153a. When the spill port 153a is closed, the fuel pressure in the pump chamber 110a rapidly rises, and the seat valve 150 is maintained in a state where the spill port 153a is closed by the high fuel pressure. The force acting on the seat valve 150 in the seating direction is far greater than the urging force of the coil spring 143 in the seating direction.

Therefore, when the spill port 153a of the seat valve 150 is closed once during the upward stroke of the plunger 111, the seat valve 150 is separated from the valve seat 153b, even if the energization of the solenoid coil 131 is released. , The spill port 153a is not opened. In this way, the energization time to the solenoid coil 131 can be shortened, power can be saved, and of course, it is only necessary to energize for a short time T3, so that the control by the ECU 11 can be simplified.

On the other hand, when the plunger 111 is in the downward stroke, a negative pressure acts on the seat valve 150, so that the spill port 153a is automatically opened even if the solenoid coil 131 is energized. The low-pressure fuel is supplied from the fuel chamber 120c and the low-pressure fuel passage 120b communicating with the spill port 153a to the pump chamber 110a.
Inhaled. Therefore, at this time, the spill port 153a
Is also a suction port. Here, since the seat valve 150 is in the free state, the seat valve 150 may exhibit an unreliable behavior due to the influence of the surrounding pressure fluctuation (the influence of the pressure pulsation). However, in the high-pressure fuel pump P of this embodiment, the stem 1
Since the diameter of the movable chamber 40b is considerably smaller than that of the mover section 140a, the fuel storage chamber 120c including the working chamber 120a is formed.
Sufficient volume (V) is secured inside. As a result, even if the mover section 140a moves up and down in the working chamber 120a to cause a volume change ΔV, the change rate ΔV / V is small, and the generated pressure pulsation is small. For this reason, the behavior of the seat valve 150 due to pressure pulsation that is difficult to control can be suppressed, and a high-pressure fuel pump P with excellent controllability can be obtained.

FIG. 4 shows a discharge amount control valve 200 according to a second embodiment of the present invention. The same members as those in the first embodiment are denoted by the same reference numerals (the same applies hereinafter).
The discharge amount control valve 200 is a lifter 140 according to the first embodiment.
To the lifter 240 and the seat valve 150 to the seat valve 250
Respectively. And the stem part 25
0b is integrated with the seat valve portion 250a.
Was formed. Therefore, in the present embodiment, the lifter 240 corresponds to the mover section in the present invention. By the way, inside the lifter 240 and the stem part 250b, there is a hollow part 240a.
And a hollow portion 250c are respectively formed. Similar to the first embodiment, the hollow portions 240a and 250c are formed by piercing bottomed cylindrical hollow portions from each end and caulking and fixing lid members 245 and 255 to their end openings. Space. The lid members 245 and 255 are each made of a hard steel chip, and the lifter 240 and the stem 2
50b is secured.

FIG. 5 shows a discharge amount control valve 300 according to a third embodiment of the present invention. The discharge amount control valve 300 is the second
The lifter 240 of the embodiment is changed to a lifter 340, and the seat valve 250 is changed to a seat valve 350. The seat valve 350 includes the seat valve portion 350a and the stem portion 3
50b is integrated with the seat valve 250, but differs from the seat valve 250 in that the stem 350b extends to the inside of the center of the lifter 340. It should be noted that the stem 250b is provided inside the stem 350b.
Similarly to b, a hollow portion 350c whose end opening is closed by a lid member 345 is formed.

The lifter 340 has a cylindrical hollow portion 340a formed upward from the lower center. The inner diameter of the hollow portion 340a is slightly larger than the outer diameter of the stem portion 350b, and the stem portion 350b can slide inside the hollow portion 340a. A small-diameter step is formed at the upper bottom of the hollow portion 340a, and the upper end of the stem 350b is positioned in contact with the step. When the stem 350b is lengthened as in this embodiment, the lifter 340 and the seat valve 350a
If a guide for supporting the stem portion 350b is appropriately disposed between the seat valve 350b, the lift operation of the seat valve 350 can be stabilized and controllability can be improved.

[0034]

According to the present invention, since the hollow portion is provided in at least one of the stem portion, the seat valve portion, and the mover portion, the inertial mass of the movable portion can be reduced, and the fuel control with excellent responsiveness can be achieved. A valve is obtained. Further, when this fuel control valve is used as a discharge control valve of a high-pressure fuel pump, a high-pressure fuel pump having excellent controllability and capable of performing high-precision control can be obtained.

[Brief description of the drawings]

FIG. 1 is a fuel system diagram using a high-pressure fuel pump according to the present invention.

FIG. 2 is a view showing a discharge amount control valve according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating an example of discharge amount control by a high-pressure fuel pump.

FIG. 4 is a view showing a discharge amount control valve according to a second embodiment of the present invention.

FIG. 5 is a view showing a discharge amount control valve according to a third embodiment of the present invention.

[Explanation of symbols]

 P High-pressure fuel pump 111 Plunger 110 Pump body 120 Valve body 100 Discharge rate control valve 110b High-pressure fuel passage 120b Low-pressure fuel passage 110a Pump chamber 120a Working chamber 140a Mover part 140b Stem part 140c Hollow part 150 Seat valve (seat valve part) 153a Spillport

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G066 AA02 AA07 AB02 AC02 AC06 AC09 AD12 BA19 BA61 BA63 BA67 CA08 CA09 CA20U CE24 CE34 DC01 DC09 DC18 3H071 AA07 BB01 CC17 DD12 DD14

Claims (2)

[Claims] An opening / closing port is provided by a port interposed in a fuel passage and having a valve seat around the port, and the port is urged in a seating direction with respect to the valve seat and is separated from the valve seat. A seat valve portion, a mover portion provided separately from the seat valve portion on the opposite side of the seat valve portion with respect to the port, and electromagnetically controlling opening and closing of the port by the seat valve portion; A stem portion that mediates the urging force of the seat valve portion in the unseating direction from the mover portion to the seat valve portion, wherein at least the seat valve portion, the mover portion, and the stem portion Either of the fuel control valves includes a hollow portion in which gas is sealed. 2. A pump body having a pump chamber formed so as to be able to communicate with a low-pressure fuel passage communicating with a low-pressure fuel supply source and a high-pressure fuel passage supplying high-pressure fuel to an injector side, and is fitted into the pump chamber. By opening and closing a plunger that draws and discharges fuel by reciprocatingly sliding in the pump chamber by receiving a driving force from a driving source, and a spill port provided in a fuel overflow passage communicating with the pump chamber. A discharge amount control valve for adjusting a discharge amount of the high-pressure fuel to the high-pressure fuel passage. The discharge amount control valve is formed on the opposite side of the pump chamber with respect to the spill port, and the overflow flow is formed. A valve body having an operating chamber communicating with a passageway, and a valve body formed on the pump chamber side of the spill port, which is biased in a seating direction and detached from the valve seat. A seat valve portion that opens and closes the spill port by a seat; a mover portion that is disposed in the working chamber separately from the seat valve portion and electromagnetically controls opening and closing of the spill port by the seat valve portion; A stem portion for mediating the urging force of the seat portion in the seat-separating direction of the seat valve portion from the mover portion to the seat valve portion; and at least one of the seat valve portion, the mover portion, and the stem portion. A high-pressure fuel pump, comprising: a hollow portion formed and filled with a gas therein.