JP3700800B2 - Accumulated fuel injection system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetically-controlled pressure-accumulated fuel injection device that accumulates high-pressure fuel in a common rail that is a kind of surge tank and injects the accumulated high-pressure fuel into an internal combustion engine.
[0002]
[Prior art]
Conventionally, electromagnetically controlled fuel injection in which high-pressure fuel is pressurized and pumped to a common rail by a high-pressure supply pump to accumulate pressure, and the high-pressure fuel accumulated in the common rail is injected into an internal combustion engine (hereinafter referred to as an “internal combustion engine”). As apparatuses, those shown in Japanese Patent Application Laid-Open Nos. 3-964, 7-317625, and 1-2224458 are known. These fuel injection devices are provided with a pressure control chamber on the side opposite to the injection hole of the valve member that opens and closes the injection hole, and by connecting and disconnecting the pressure control chamber and the low pressure side space with a solenoid valve, the fuel injection timing from the injection hole And the fuel injection amount is controlled.
[0003]
[Problems to be solved by the invention]
In recent years, the size of the space between the cylinder head and the engine head cover has been limited due to demands for engine downsizing, and various parts occupying this space, such as camshafts, cams, valve springs, rocker arms, and fuel injection devices Injectors and the like are arranged close to each other. In order to mount an injector in such a limited space without interfering with other parts, it is increasingly necessary to reduce the diameter of the injector.
[0004]
However, in the fuel injection device disclosed in Japanese Patent Application Laid-Open No. 3-964, the spring for urging the movable member of the solenoid valve is housed in the core of the solenoid valve. It is necessary to provide in the center of the. Therefore, there exists a problem that the outer diameter of a core, ie, the outer diameter of an injector, becomes large.
In order to prevent an increase in the diameter of the core portion of the solenoid valve, in the fuel injection device disclosed in Japanese Patent Laid-Open No. 7-317625, a spring is disposed on the same side as the armature with respect to the core. However, in this configuration, a spring locking member that urges the movable member of the electromagnetic valve in the valve closing direction is required between the armature and the spring. Therefore, there is a problem in that the structure in the solenoid valve becomes complicated and the assembly becomes complicated and the manufacturing cost increases.
[0005]
In the fuel injection device disclosed in JP-A-1-224458, the armature and the spring for biasing the movable member of the solenoid valve are disposed on the opposite side in the axial direction of the core, so that the core diameter is not increased. In addition, the configuration of the solenoid valve is simplified to facilitate assembly. However, since the core supports the movable member of the solenoid valve so that the core can reciprocate, the core is processed and assembled with high accuracy in order to accurately align the movable member and the low-pressure side opening of the pressure control chamber. It is required to be attached. Therefore, in JP-A-1-224458, since a core cannot be formed by a method of laminating silicon steel plates that are difficult to process with high precision, it becomes difficult to suppress the generation of eddy currents, and the generation of eddy currents Suffers power loss. Further, a structure in which the core is screwed to the yoke is employed in order to ensure the assembling accuracy. However, the diameter of the solenoid valve is increased by increasing the radial thickness of the yoke. Furthermore, there is a problem that the number of man-hours for threading increases and the number of man-hours for assembly increases.
[0006]
The present invention has been made to solve such problems, and an object of the present invention is to provide a fuel injection device capable of reducing the diameter with a simple structure.
[0007]
[Means for Solving the Problems]
According to the fuel injection device of the first aspect of the present invention, since the armature and the urging means are disposed on the opposite side in the axial direction with respect to the core, it is not necessary to provide a space for accommodating the urging means in the core. The diameter of the fuel injection device can be reduced by reducing the diameter of the core. Furthermore, the urging structure by the urging means is simplified and the assembly is facilitated as compared with the configuration in which the armature and the urging means are arranged on the same side.
[0008]
In addition, since the movable member of the electromagnetic valve is supported so as to be reciprocally movable outside the core and not supported by the core, the positional accuracy of the movable member can be ensured without assembling the core with high accuracy. Therefore, since the assembly structure of the core is simplified, the diameter of the fuel injection device can be reduced by reducing the diameter of the core as much as possible while satisfying the required performance of the solenoid valve and allowing the movable member to be inserted. Furthermore, since high accuracy is not required when processing and assembling the core, the manufacturing cost can be reduced. Further, for example, since the core can be formed by laminating silicon steel plates, generation of eddy current can be suppressed and power supplied to the electromagnetic valve can be efficiently converted into magnetic force. Accordingly, the diameter of the solenoid valve can be reduced and the diameter of the fuel injection device can be reduced.
[0009]
Since the electromagnetically controlled fuel injection device having such a small diameter can be attached to an engine having various types and sizes without interfering with other parts, it is not necessary to develop and manufacture an injector for each engine. Therefore, the manufacturing cost of the fuel injection device can be reduced by mass production.
Furthermore , by forming the first movable portion and the second movable portion of the movable member separately, the first movable portion and the second movable portion having a short axial length can be processed separately. . Therefore, compared to the case where the first movable part and the second movable part are integrally formed, the first movable part and the second movable part can be easily processed, and the processing accuracy can be easily improved.
[0010]
According to the fuel injection device of the second or third aspect of the present invention, the fitting portion between the first movable portion and the second movable portion of the movable member formed separately is provided with a concave tapered surface and a convex shape. By adopting a fitting structure with the tapered surface, positioning of the first movable part and the second movable part is easy. Therefore, since the assembly work is simplified, it is easy to configure an automated production line using a robot or the like. In addition, since the first movable portion and the second movable portion are pressed against each other by the biasing means, the first movable portion and the second movable portion are unlikely to be displaced. Moreover, even if a positional deviation occurs, it can return to the appropriate position.
[0011]
Moreover, since the center hole used as the reference can be used as it is as the concave tapered surface during the cutting of the first movable part or the second movable part, an increase in the number of processing steps can be suppressed.
According to the fuel injection device of claim 4 of the present invention, it is not necessary to provide a fuel discharge passage around the solenoid valve by providing a fuel discharge passage for discharging surplus fuel inside the movable member of the solenoid valve. The diameter of the injection device can be reduced.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a plurality of examples showing embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
1 to 4 show a fuel injection device according to a first embodiment of the present invention.
3 and 4 show a state in which the injector 1 as the fuel injection device of the first embodiment is attached to a DOHC 4-cylinder engine. The injector 1 is fitted in a mounting hole 100 a provided in the cylinder head 100, and a later-described injection hole of the injector 1 faces the combustion chamber 120. As shown in FIG. 4, the bifurcated fixing member 101 holds the notch portion 13 b while locking the locking portion 13 a of the injector body 13. The fixing member 101 fixes the injector 1 to the cylinder head 100 by tightening the bolts 102.
[0013]
The injector 1 is supplied with high-pressure fuel having a constant pressure accumulated by a common rail (not shown) from the fuel pipe 103 through the inlet 60. The engine head cover 110 and the injector 1 are sealed with seal members 121 and 122, respectively.
The injector 1 is of an electromagnetic control type, and a wire harness 104 that sends a control signal from an engine control device (not shown) to the injector 1 is connected to the connector 70. The fuel discharge pipe 105 discharges surplus fuel in the injector 1 and is connected to a joint 73 a of the union 73. The union 73 is fitted and fixed to a recovery connecting portion 50a of a housing 50 described later of the injector 1.
[0014]
Around the injector 1, an exhaust camshaft 111, a cam 113, an intake camshaft 112, and a cam 114 are disposed. The exhaust valve 115 and the intake valve 116 are driven by cams 113 and 114.
As shown in FIG. 2, a needle valve 20 for opening and closing the injection hole 11a is accommodated in the nozzle body 11 of the injection nozzle 10 provided on the injection hole side of the injector 1 so as to reciprocate. The nozzle body 11 and the injector body 13 are coupled by a retaining nut 14 with a distance space 12 interposed therebetween. A pressure pin 21 is disposed on the side opposite to the injection hole of the needle valve 20, and a control piston 22 that contacts or couples to the pressure pin 21 is disposed on the side opposite to the pressure pin 21. The needle valve 20, the pressure pin 21, and the control piston 22 constitute a “valve member” described in the claims. The pressure pin 21 is inserted into the spring 23, and the spring 23 biases the pressure pin 21 downward in FIG. 2, that is, in the injection hole closing direction. A pressure control chamber 62 is provided on the side opposite to the injection hole of the control piston 22.
[0015]
The high pressure fuel introduced from the fuel filter 61 accommodated in the inlet 60 branches into a high pressure fuel passage 63 and a high pressure fuel passage 64. The high-pressure fuel branched into the high-pressure fuel passage 63 is supplied to the fuel reservoir 24 formed in an annular shape around the needle valve 20, and the high-pressure fuel branched into the high-pressure fuel passage 64 is supplied to the pressure control chamber 62. The pressure of the high-pressure fuel in the fuel reservoir 24 urges the needle valve 20 upward in FIG. 2, that is, in the lift direction in which the fuel reservoir 24 and the injection hole 11a communicate with each other. 2, that is, the needle valve 20 biases the control piston 22 in a direction to close the nozzle hole 11a.
[0016]
The low pressure fuel passage 65 is a fuel passage for collecting leaked fuel from the sliding clearance of the control piston 22 and the needle valve 20 and communicates with a low pressure fuel chamber 68 serving as a low pressure side space. A fuel discharge passage 69 formed in the housing 50 is a passage for discharging surplus fuel in the injector from the low pressure fuel chamber 68 to the outside of the injector 1.
[0017]
As shown in FIG. 1, the distance pieces 51 and 52 are sandwiched between the injector body 13 and the valve cylinder 45. The first throttle hole 66 is formed in the distance piece 51 and regulates the amount of fuel flowing from the high pressure fuel passage 64 into the pressure control chamber 62. The second throttle hole 67 is formed in the distance piece 52 and regulates the amount of fuel flowing from the pressure control chamber 62 to the low pressure fuel chamber 68.
[0018]
The distance pieces 51 and 52 are accurately positioned with respect to the injector body 13 by pins (not shown) inserted through holes (not shown) provided in the injector body 13 through the distance pieces 51 and 52.
The electromagnetic valve 30 is an electromagnetic two-way valve that intermittently connects the pressure control chamber 62 and the low-pressure fuel chamber 68, and is disposed between the retaining nut 59 and the injector body 13. The pin 53 is used to position the core 31 and the housing 50 in the rotational direction, and when the retaining nut 59 is tightened, the core 31 and the housing 50 rotate relative to each other to supply power to the coil 32 (not shown). This prevents the load from being applied to the battery.
[0019]
The coil 32 is wound around the core 31, and power is supplied from a terminal 71 embedded in the connector 70. The core 31 is formed by laminating silicon steel plates having a thickness of about 0.2 mm in a spiral shape, and a silicon steel plate is welded to a cylindrical member 33 disposed on the inner periphery. A pressing member 42 of the movable member 40 described later is inserted into the cylindrical member 33. The cylindrical member 33 does not need to support the pressing member 42 and can be welded to the silicon steel plate constituting the core 31. Therefore, the cylindrical member 33 does not need to be a magnetic material, and can be formed thin with nonmagnetic SUS or the like. Since the cylindrical member 33 can be formed thin, a magnetic circuit can be configured by reducing the inner diameter of the core 31 to the vicinity of the accommodation hole that accommodates the pressing member 42. Therefore, desired performance can be obtained even when the diameter of the core 31 is reduced.
[0020]
The movable member 40 includes a valve shaft 41 as a first movable part, a pressing member 42 as a second movable part, a spherical member 43 and a support member 44. The valve shaft 41 and the pressing member 42 are pressed against each other by the force received from the fuel pressure in the pressure control chamber 62 and the urging force of the spring 47, and are reciprocated without being separated from each other. The pressing member 42 is made of nonmagnetic stainless steel or the like in order to avoid an influence on the magnetic circuit. The valve shaft 41 is supported by a valve cylinder 45 disposed on the nozzle hole side of the core 31 so as to be reciprocally movable, and is formed of a material having excellent wear resistance. Since the valve shaft 41 is outside the magnetic circuit, it may be made of a magnetic material. An armature 34 accurately positioned in the radial direction and the axial direction is fixed to the core side of the valve shaft 41 by any one or a plurality of means such as press-fitting, caulking, and welding, and the valve shaft 41 reciprocates together with the armature 34. . Since the armature 34 is required to have characteristics as a part of the magnetic circuit rather than wear resistance, it is made of, for example, silicon steel. The armature 34 is formed with 4 to 20 through holes 34a in order to reduce movement resistance in the fuel.
[0021]
The lift amount of the movable member 40 can be adjusted by changing the axial length of the spacer 54. The maximum lift position of the movable member 40 is defined by the valve shaft 41 being locked to the cylindrical member 33. At this time, since an air gap is secured between the armature 34 and the core 31, the movable member 40 quickly moves downward in FIG. 1 when the power supply to the coil 33 is turned off.
[0022]
As shown in FIG. 1, a support member 44 formed in a cylindrical shape is fixed to the distal end portion of the valve shaft 41 by press-fitting or welding. A clearance of several μm is formed between the support member 44 and the spherical member 43, and the spherical member 43 is rotatable by a conical concave surface formed at the tip of the valve shaft 41 and the inner wall of the support member 44. It is assembled. The spherical member 43 is prevented from falling off the support member 44 by caulking the tip of the support member 44. The spherical member 43 has a structure in which a flat portion is processed in a part of a ceramic or cemented carbide sphere, and the lift amount of the valve shaft 41 is about 50 to 150 μm. Even if the spherical member 43 tries to rotate more than a predetermined angle, the flat surface portion of the spherical member 43 is locked to the distance piece 52. Therefore, the flat portion of the spherical member 43 always faces the second throttle hole 67. Since the spherical member 43 closes the second throttle hole 67 by the flat surface contact with the distance piece 52, the sealing area between the spherical member 43 and the distance piece 52 is increased, and fuel leakage from the pressure control chamber 62 is generated. Can be reduced. Further, even when the position and relative angle between the spherical member 43 and the second throttle hole 67 are shifted, the spherical member 43 can reliably block the second throttle hole 67.
[0023]
The pressing member 42 has a clearance larger than the sliding clearance formed as the cylindrical member 33 and is inserted into the cylindrical member 33 so as to be reciprocally movable. A locking portion 42 a is formed on the side opposite to the armature of the pressing member 42, and a spring 47 is sandwiched between the locking portion 42 a and the shim 46. The spring 47 urges the pressing member 42 in a direction in which the spherical member 43 closes the second throttle hole 67. The biasing force of the spring 47 can be adjusted by changing the thickness of the shim 46. In addition to this, it is possible to adjust the urging force of the spring 47 by changing the locking position of the spring 47 by screwing from the outside.
[0024]
The valve shaft 41 and the pressing member 42 are fitted to each other by a concave tapered surface 41 a formed on the valve shaft 41 and a convex tapered surface 42 b formed on the pressing member 42. Due to the fitting of the concave and convex tapered surfaces, a force toward the axial center is always applied to the pressing member 42. Therefore, even if the pressing member 42 is not supported by the cylindrical member 33, the position difference between the valve shaft 41 and the pressing member 42 hardly occurs, and even if the pressing member 42 is shifted from the center of the shaft, it can be surely returned to the proper position. it can. As the taper surface 41a of the valve shaft 41, the center hole used as a reference when the valve shaft 41 is cut can be used as it is.
[0025]
Fuel passages 45a, 41b, and 42c formed in the valve cylinder 45, the valve shaft 41, and the pressing member 42, respectively, are passages for discharging excess fuel in the low pressure fuel chamber 68 from the fuel discharge passage 69 to the outside of the injector.
Next, the assembly procedure of the injector 1 will be described.
(1) The nozzle body 11, the distance piece 12, the pressure pin 21, the control piston 22, the spring 23, the distance pieces 51 and 52, the fuel filter 61, and the like are incorporated in the injector body 13 in advance. By fixing the valve cylinder 45 to the injector body 13 with screws, the space between the injector body 13 and the valve cylinder 45 is sealed.
[0026]
(2) The valve shaft 41 is fitted into the valve cylinder 45, and the spacer 54 is assembled to the outer periphery of the valve shaft 41.
(3) Separately from the injector body 13 side, the core 31, around which the coil 32 is wound, the pressing member 42, the spring 47, the shim 46, the housing 50, the pin 53, and the retaining nut 59 are assembled, and the connector 70 is resin-molded.
[0027]
(4) The separately assembled injector body side and solenoid valve side are coupled by screwing a retaining nut 59 to the valve cylinder 45. At this time, since the convex tapered surface 42b of the pressing member 42 is automatically and reliably fitted to the concave tapered surface 41a of the valve shaft 41, the injector body side and the solenoid valve side can be coupled in a short time. . Then, the O-ring 72 and the union 73 are attached to the recovery connection portion 50a of the housing 50, and the union 73 is fixed by the circlip 74, whereby the assembly of the injector 1 is completed.
[0028]
Next, a procedure for attaching the injector 1 to the cylinder head 100 will be described.
(1) The exhaust valve 115, the intake valve 116, and the camshafts 111 and 112 are already assembled before the injector 1 is attached to the cylinder head 100.
(2) The injector 1 is fitted into the mounting hole 100a, and the injector 1 is fixed to the cylinder head 100 while being pressed by the fixing member 101. Thus, the injector 1 is disposed coaxially with the combustion chamber 120.
[0029]
(3) The engine head cover 110 to which the seal members 121 and 122 are attached is covered from the top of the injector 1.
(4) The fuel pipe 103 is connected to the inlet 60, the fuel discharge pipe 105 is connected to the recovery connecting portion 50a via the union 73, and the wire harness 104 is connected to the connector 70, whereby the injector 1 to the engine head 100 is connected. Installation is complete.
[0030]
Next, the operation of the fuel injection device will be described.
(1) When the coil 32 is turned off, the pressing member 42 is pressed downward in FIG. The spherical member 43 is seated on the distance piece 52 and the communication between the pressure control chamber 62 and the low pressure fuel chamber 68 is blocked.
Since the pressure receiving area of the control piston 22 is larger than the pressure receiving area of the needle valve 20 and the urging force of the spring 23 works in the nozzle hole closing direction, the control piston 22 moves in the nozzle hole closing direction from the fuel pressure in the pressure control chamber 62. The sum of the force received and the biasing force of the spring 23 is greater than the force that the needle valve 20 receives in the lift direction from the fuel pressure in the fuel reservoir 24. Therefore, the nozzle hole 11a is closed by the needle valve 20, and fuel injection is not performed.
[0031]
(2) When energization of the coil 32 is turned on, the sum of the electromagnetic force that attracts the armature 34 generated in the coil 32 and the force that the movable member 40 receives in the valve opening direction from the fuel pressure in the pressure control chamber 62 is Since it becomes larger than the urging force, the movable member 40 is lifted and the spherical member 43 is separated from the distance piece 52. When the spherical member 43 is separated from the distance piece 52, the second throttle hole 67 and the low pressure fuel chamber 68 communicate with each other, and the fuel in the pressure control chamber 62 flows out from the second throttle hole 67 to the low pressure fuel chamber 68. Since the passage resistance of the second throttle hole 67 is smaller than the passage resistance of the first throttle hole 66, pressure control is performed when the spherical member 43 is separated from the distance piece 52 and the pressure control chamber 62 and the low pressure fuel chamber 68 communicate with each other. The fuel pressure in the chamber 62 decreases. The fuel pressure in the pressure control chamber 62 decreases, and the sum of the force that the control piston 22 receives in the injection hole closing direction from the fuel pressure in the pressure control chamber 62 and the urging force of the spring 23 is changed from the fuel pressure in the fuel reservoir 24 to the needle valve. When 20 becomes smaller than the force received in the lift direction, the needle valve 20 is lifted and fuel is injected from the injection hole 11a.
[0032]
In the first embodiment of the present invention described above, the armature 34 is disposed on the injection hole side with respect to the core 31, and the spring 47 is disposed on the counter-injection hole side outside the core with respect to the armature 34. Since it is not necessary to provide a space for accommodating the spring 47 inside the core 31, the core 31 can be reduced in diameter. Furthermore, since the structure for urging the movable member 40 becomes simple, the assembly of the electromagnetic valve 30 becomes easy.
[0033]
Further, by supporting the movable member 40 not by the core 31 but by the valve cylinder 45 outside the core, the position accuracy of the valve shaft 41 can be ensured without processing and assembling the core 31 with high accuracy. Therefore, it is not necessary to provide a complicated structure for positioning the core 31 in the core 31 and the support portion of the core 31, and the assembly structure of the electromagnetic valve 30 can be simplified. Therefore, the diameter of the injector 1 can be reduced, In addition, the manufacturing cost can be reduced. Furthermore, since the core 31 can be formed by laminating silicon steel plates that suppress the generation of eddy currents, power loss due to the generation of eddy currents is reduced, and supplied power is efficiently converted into magnetic force. Therefore, the desired performance can be obtained even when the diameter of the solenoid valve is reduced.
[0034]
Further, since the fuel passages 45a, 41b, and 42c for guiding excess fuel to the fuel discharge passage 69 are provided inside the valve cylinder 45, the valve shaft 41, and the pressing member 42, a fuel passage for discharge is provided on the outer peripheral side of the electromagnetic valve 30. There is no need to provide this, and the diameter of the injector can be further reduced.
The injector 1 having a reduced diameter does not interfere with various components arranged around the injector as shown in FIGS. 3 and 4, and therefore is particularly suitable for mounting on a small-sized engine with a limited mounting space. It is valid. Moreover, since the same injector can be used for engines having various types and sizes, the manufacturing cost of the injector can be reduced by mass production.
[0035]
Further, the valve shaft 45, the spacer 54, the solenoid valve 30 excluding the valve shaft 31, and the housing 50 need only be stacked in order and fastened by the retaining nut 59, so that the assembling work is facilitated.
In addition, since the fitting between the valve shaft 41 and the pressing member 42 of the movable member 40 formed separately is formed by the concave and convex tapered surfaces, the positioning of the valve shaft 41 and the pressing member 42 is easy. Since the pressing member 42 always receives a force at the center of the axis, the pressing member 42 is unlikely to be misaligned, and can quickly return to an appropriate position even if the misalignment occurs.
[0036]
(Second embodiment)
A second embodiment of the present invention is shown in FIG. Components that are substantially the same as those in the first embodiment are denoted by the same reference numerals.
The movable member 90 of the electromagnetic valve 80 includes a valve shaft 91, a pressing member 92, a spherical member 43, and a support member 44. The valve shaft 91 includes a first movable portion 91a and a second movable portion 91b, and is integrally formed. The first movable portion 91 a is supported by the valve cylinder 45 so as to be reciprocally movable, and the second movable portion 91 b is inserted through the inner periphery of the cylindrical member 33 without being supported by the cylindrical member 33. The pressing member 92 is fitted to the end of the second movable portion 91 b opposite to the injection hole, and transmits the urging force of the spring 47 to the valve shaft 91.
[0037]
Also in the second embodiment, since the movable member 90 is not supported by the core 31, the diameter of the injector can be reduced as in the first embodiment.
In the second embodiment, when the diameter of the spring 47 is small, the pressing member, which is the movable member side receiving member of the spring 47, can be formed with a small diameter. Therefore, the spring receiving portion is formed directly on the end portion of the valve shaft. It is also possible to lock the spring directly with the valve shaft without providing a spring.
[0038]
Further, the pressing member 92 and the valve shaft 91 may be fitted to each other between the concave and convex tapered surfaces as in the first embodiment.
In the above-described plurality of examples showing the embodiment of the present invention described above, the movable member is supported so as to be reciprocally movable on the nozzle hole side of the core, but the first movable portion and the second movable portion of the movable member are supported. When formed integrally, it is also possible to support the movable member so as to reciprocate on the side opposite to the injection hole of the core. In addition, an armature is arranged on the nozzle hole side of the core, and a spring as a biasing means for biasing the movable member is arranged on the counter nozzle hole side of the core. If the open / close state of the valve is reversed, it is possible to arrange a spring on the nozzle hole side of the core and an armature on the counter nozzle hole side of the core.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a main part of an injector according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view showing the injector of the first embodiment.
FIG. 3 is a cross-sectional view showing a state in which the injector of the first embodiment is mounted on a cylinder head.
4 is a cross-sectional view taken along arrow IV in FIG. 3;
FIG. 5 is a sectional view showing a main part of an injector according to a second embodiment of the present invention.
[Explanation of symbols]
1 Injector (fuel injection device)
10 injection nozzle 11a injection hole 20 needle valve (valve member)
21 Pressure pin (valve member)
22 Control piston (valve member)
30 Solenoid valve 31 Core 32 Coil 34 Armature 40 Movable member 41 Valve shaft (first movable part)
42 Pressing member (second movable part)
43 Spherical member (movable member)
44 Support member (movable member)
47 Spring (biasing means)
63, 64 High-pressure fuel passage 65 Low-pressure fuel passage 66 First throttle hole 67 Second throttle hole 68 Low-pressure fuel chamber 90 Movable member 91 Valve shaft (movable member)
91a 1st movable part 91b 2nd movable part

Claims (4)

An accumulator fuel injection device that injects high-pressure fuel accumulated in a common rail into an internal combustion engine,
A valve member that intermittently connects the high-pressure fuel passage capable of supplying the accumulated high-pressure fuel to the nozzle hole and the nozzle hole;
A core around which a coil is wound, a low pressure side space, and a pressure control chamber that is provided on the side opposite to the injection hole of the valve member and urges the valve member in the injection hole blocking direction by a fuel pressure supplied from the high pressure fuel passage; A movable member that is intermittently inserted into the core in the axial direction, and is disposed on one axial end side of the core so as to reciprocate together with the movable member, and is attracted to the core when the coil is energized. And an electromagnetic valve having a biasing means disposed on the side opposite to the armature of the core and biasing the movable member in a direction opposite to the suction direction of the armature toward the core,
The movable member may have a first movable portion that is reciprocally movably supported by the core outside, and a second movable portion that is inserted through without being supported by the core,
The accumulator fuel injection apparatus, wherein the first movable part and the second movable part are formed separately . The fitting portion of the first movable portion with the second movable portion has a concave tapered surface, and the fitting portion of the second movable portion with the first movable portion is a convex taper. The pressure accumulation type fuel injection device according to claim 1, further comprising a surface. The fitting portion of the first movable portion with the second movable portion has a convex tapered surface, and the fitting portion of the second movable portion with the first movable portion is a concave taper. The pressure accumulation type fuel injection device according to claim 1, further comprising a surface. The accumulator fuel injection device according to any one of claims 1 to 3, wherein a fuel discharge passage for discharging surplus fuel is provided inside the movable member.

Images