JP2952820B2 - Electromagnetic fuel injection valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic fuel injection valve, and more particularly to an electromagnetic fuel injection valve capable of directly injecting high-pressure fuel of, for example, 1 to 12 MPa into a cylinder of an internal combustion engine. Regarding improvement.

[0002]

2. Description of the Related Art Conventionally, such an electromagnetic fuel injection valve is disclosed in, for example, Japanese Patent Application Laid-Open Nos. 4-164149 and 8-2.
It is already known from Japanese Patent No. 10217 and the like.

[0003]

However, in the electromagnetic fuel injection valve disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 4-164149, the diameter of the seating portion of the valve body on the valve seat provided at the front end of the housing. Since the diameter of the valve body is larger than that of the valve body, a high fuel pressure acts on the valve body in the direction of seating on the valve seat, and resists the force in the seating direction of such a valve body on the valve seat. Since the electromagnetic force required to open the valve body is required, the number of turns and wire diameter of the coil can be set relatively large, and the fixed core, movable core and housing can be formed of a material with high magnetic flux density. It is necessary to make the entire system larger, or the cost becomes higher.

On the other hand, in the electromagnetic fuel injection valve disclosed in JP-A-8-210217, a spool type three-way valve which is not affected by high fuel pressure is operated by the electromagnetic force of a coil. By switching the pressure difference between the front and rear of the valve body, the valve body is opened and closed so that it is not affected by the fuel pressure.However, the three-way valve is required, so the electromagnetic fuel injection valve is large. Is inevitable.

The present invention has been made in view of the above circumstances, and enables a valve element to be driven by a relatively small electromagnetic force without being affected by the fuel pressure. It is an object of the present invention to realize a small-sized electromagnetic fuel injection valve capable of injecting fuel at low cost.

[0006]

According to one aspect of the present invention, there is provided a coil assembly in which a coil is wound around a bobbin; and a first storage hole for receiving the coil assembly. A second storage hole formed to be smaller in diameter than the first storage hole and coaxially connected to a front end of the first storage hole via a step portion, an end wall portion closing the front end of the second storage hole, and a second storage hole. A coaxial valve hole is opened in the center to form a valve seat provided on the inner surface of the center portion of the end wall portion, a fuel reservoir chamber connected to the valve hole is formed, and a hemisphere projecting from the outer surface of the center portion of the end wall portion is formed. A housing made of a magnetic material having a protrusion, a fuel injection hole formed in the protrusion, and a fuel inlet port having an inner end opened in the inner surface of the second storage hole; and a valve chamber communicating with the fuel inlet port. Formed between the end wall and fitted to the bobbin A cylindrical fixed core coupled to a rear end portion of the housing; a movable core housed in the valve chamber opposed to a front end of the fixed core; and a movable core that can be seated on the valve seat. A valve body fixed to the front end and provided with a communication hole extending in the axial direction of the valve hole through the fuel storage chamber through the front end; an axial front portion slidable coaxially with and relative to the movable core; A guide member having a front end opposed to a rear end of the communication hole and an axial rear portion slidably fitted to the fixed core; and a coaxial with the fixed core at a rear side of the guide member. A receiving member that is press-fitted; a pressing member that is inserted into the fixed core so as to be movable in the axial direction by contacting a rear end of the guide member; Touch the front end of the guide member to the valve A return spring provided between the receiving member and the pressing member by exerting a spring force in a direction in which the valve member is to be moved, and a diameter of a seating portion of the valve body to the valve seat and fitting of the guide member to the movable core. The joint diameter is set to be substantially the same, and the valve body is provided with the communication hole.
A second valve seat with the rear end opened at the center and facing the rear side is provided.
And a second valve seat is seated on the front end of the guide member.
Possible valve portion is formed, characterized in Rukoto.

[0007] According to such a configuration, when the valve body is seated on the valve seat, the valve body has an area obtained by subtracting the cross-sectional area of the guide member fitted to the movable core from the maximum cross-sectional area of the movable core. The sum of the force obtained by multiplying the valve body by the fuel pressure and the spring force of the return spring acts in the direction in which the valve body is seated on the valve seat. The force obtained by multiplying the area obtained by subtracting the area of the above and the fuel pressure acts in a direction to move the valve body away from the valve seat, but the diameter of the seating portion of the valve body to the valve seat and the guide member to the movable core Since the fitting part diameter is set to be almost the same, the electromagnetic force required to operate the valve body in the valve opening direction by energizing the coil is a value that only overcomes the spring force of the return spring. It is sufficient if the fuel pressure is high, and it is not affected by the fuel pressure. It can be allowed to open operating a valve body with a small electromagnetic force. Therefore, it is not necessary to use an expensive material having a high magnetic flux density as a material for the fixed core, the movable core, and the housing, and it is not necessary to increase the number of turns and the wire diameter of the coil. And at a low cost. Further, when it is assumed that a high pressure acts on the fuel accumulation chamber from the cylinder side of the engine body, for example, in a state where the valve body is seated on the valve seat, since the communication hole is provided in the valve body, the high pressure Will act in a balanced manner before and after the valve element, and the valve element and the movable core will not be operated to the valve opening side. Further, in a state where the valve body is separated from the valve seat by the excitation of the coil, high-pressure fuel pressure acts in a balanced manner before and after the valve body by the communication hole, and the pressure balance between the valve body and the movable core is reduced. It does not break. Also
In particular, the valve body has the rear end of the communication hole opened at the center.
A second valve seat facing the rear side is provided, and the guide member
At the front end of the valve is formed a valve portion which can be seated on the second valve seat.
Between the guide member and the movable core from the communication hole side
It is possible to prevent fuel from leaking.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the movable core of the guide member is fitted to a guide member directly fitted to the movable core and the fixed core. A leak passage extending from the outer surface of the fitting portion to the rear end of the guide member is provided, a leak hole communicating with the leak passage is provided in the pressing member, and the receiving member is formed in a cylindrical shape, thereby being movable. It is not necessary to provide a seal member between the core and the guide member, so that the number of components is reduced, and high-pressure fuel can be prevented from leaking to the communication hole side.

According to the third aspect of the present invention, in addition to the configuration of the first or second aspect of the present invention, the rearward movement limit of the guide member is restricted by contacting the outer periphery of the rear end of the guide member. by regulating surface is provided on the stationary core, as possible out to restrict the movement limit of the rearward side of the guide member by the high-pressure effect of the fuel pressure and the cylinder side of the high pressure to the front end face of the guide member.

According to a fourth aspect of the present invention, in addition to the configuration of the third aspect of the present invention, a valve is provided on the front end of the guide member which is restricted from moving backward by the regulating surface. When the movable core moves backward until the body abuts, the position of the regulating surface is set such that a predetermined gap is created between the rear end of the movable core and the front end of the fixed core, With the configuration in which the rearward moving end of the guide member is regulated, the rearward moving end of the movable core can be regulated.

According to the fifth aspect of the present invention, the above-mentioned claim is provided.
In addition to the configuration of the invention described in 1, the diameter of the seating portion of the valve portion on the second valve seat is set substantially equal to the diameter of the fitting portion of the guide member to the movable core, In a state where the valve body is separated from the valve seat, the fuel pressure can be further balanced to act on the front and rear of the valve body.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on one embodiment of the present invention shown in the accompanying drawings.

FIGS. 1 and 2 show an embodiment of the present invention. FIG. 1 is an overall longitudinal sectional view of an electromagnetic fuel injection valve.
FIG. 2 is an enlarged view of a main part of FIG. 1 in a valve open state.

[0014] First, in FIG. 1, the fuel pumped by the pump P from the fuel tank 1 through a filter F ₁ is supplied to the common fuel rail 2 to a plurality of electromagnetic fuel injection valves V ... in a multi-cylinder internal combustion engine It is supplied from the fuel rail 2 via the filter F ₂ in each of the electromagnetic fuel injection valves V .... Moreover, the fuel pressure of the fuel rail 2 is regulated to a relatively high pressure, for example, 1 MPa to 12 MPa by the regulator valve R, and fuel is directly supplied to each cylinder of the multi-cylinder internal combustion engine from the front end of each electromagnetic fuel injection valve V. It is injected.

The electromagnetic fuel injection valve V includes a coil assembly 5, a housing 6 made of a magnetic material, a cylindrical fixed core 7 fitted to the coil assembly 5, and a front end of the fixed core 7. A movable core 8 opposed to the right end of FIG. 1, a valve element 9 fixed to a front end of the movable core 8, and an axial front portion directly fitted to the movable core 8 coaxially and relatively slidably. A guide member 10 that is fitted and whose axial rear portion is directly slidably fitted to the fixed core 7, and a cylindrical receiving member that is coaxially pressed into the fixed core 7 behind the guide member 10. 11, a pressing member 12 that comes into contact with the rear end of the guide member 10 and is axially movably inserted into the fixed core 7.
And a return spring 13 provided between the receiving member 11 and the pressing member 12 by exerting a spring force for urging the movable core 8 forward.

The coil assembly 5 comprises a synthetic resin bobbin 16 having a center hole 15 and a coil 17 wound around the bobbin 16 in a cylindrical shape.

The housing 6 is formed in a stepped cylindrical shape so as to gradually decrease in diameter as it goes from the rear side to the front side. A first storage hole 20 smaller in diameter than the fitting hole 19 and a second storage hole 21 smaller in diameter than the first storage hole 20 are formed in the housing 6 sequentially and coaxially. Also the second
An end wall 22 is provided integrally with the front end of the housing 6 so as to close the front end of the storage hole 21.

The first storage hole 20 has a stepped portion 2 formed in the housing 6 between the first and second storage holes 20 and 21.
The coil assembly 5 is housed so that the front end of the coil assembly 3 is in contact with the coil assembly 5. The fixed core 7 is formed in a cylindrical shape.
The bobbin 16 in the coil assembly 5 is fitted into the center hole 15. Moreover, the fixed core 7 is integrally provided with a flange 25 for fitting the outer peripheral edge portion into the fitting hole 19 of the housing 6, and the rear end of the housing 6 is fitted to the flange 25 fitted in the fitting hole 19. By being caulked, the fixed core 7 is coupled to the housing 6 and the coil assembly 5 is sandwiched between the flange 25 and the step portion 23.

The rear portion of the housing 6 and the rear portion of the fixed core 7 projecting rearward from the housing 6 are covered with a covering portion 26 made of a synthetic resin.
6 is integrally formed with a coupler portion 27 facing a pair of terminals 28...

On the other hand, a valve chamber 29 is formed in the housing 6 between the front end of the fixed core 7 and the end wall 22 of the housing 6.

Referring to FIG. 2 as well, a valve hole 34 formed in the end wall 22 coaxially with the second storage hole 21 is opened at the center on the inner surface of the center of the end wall 22 in the housing 6. A first valve seat 35 formed at least in a tapered shape is provided, and a hemispherical protrusion 37 forming a fuel reservoir chamber 36 communicating with the valve hole 34 protrudes from an outer surface of a central portion of the end wall portion 22. The projection 37 has a plurality of fuel injection holes 3, for example.
8 are drilled. Also the housing 6 is a fuel inlet port 39 leading to the valve chamber 29 and opening is provided on the inner surface of the second housing hole 21, the fuel inlet port 39, as shown in Figure 1, the filter F ₂ Connected to the fuel rail 2 via

The movable core 8 has a rear end connected to the fixed core 7.
The valve body 9 which can be seated on the first valve seat 35 is fixed to the front end of the movable core 8 so as to be formed integrally, for example, integrally with the front end of the movable core 8. You.

The valve body 9 has a first communication hole 40 through which the front end of the fuel reservoir chamber 36 is passed, and a second communication hole 40 having a diameter larger than that of the first communication hole 40 and coaxially connected to the rear end of the first communication hole 40. The communication hole 41 is provided so as to extend along the axis of the valve hole 34. The movable core 8 has a diameter larger than that of the second communication hole 41 and is coaxial with the rear end of the second communication hole 41. The first in a row
A guide hole 42 is provided so as to open at the rear end of the movable core 8.

The stationary core 7 having a cylindrical shape has a second guide hole 43 formed coaxially with the same diameter as the first guide hole 42 of the movable core 8 in order from the front end to the rear end, and a second guide hole 43. A third guide hole 44 having a smaller diameter than the guide hole 43 and forming a step-shaped regulating surface 45 with the second guide hole 43, and an insertion having a larger diameter than the third guide hole 44. The hole 46 and a release hole 47 having a larger diameter than the insertion hole 46 are formed coaxially.

On the other hand, the guide member 10 made of a non-magnetic material
Is formed in a columnar shape which can be slidably fitted into the first and second guide holes 42 and 43. The front portion of the guide member 10 has the front end thereof at the first and second positions of the valve body 9. The movable core 8 is slidably fitted in the first guide hole 42 so as to face the second communication holes 40 and 41. Guide member 10
The rear part is slidably fitted in the second guide hole 43 in the front part of the fixed core 7.

The pressing member 12 is inserted into the third guide hole 44 movably in the axial direction so as to contact the rear end of the guide member 10. Thus, the pressing member 12 is formed in a closed-end cylindrical shape with the distal end closed, and the distal end surface of the pressing member 12 is formed in a hemispherical shape. The cylindrical receiving member 11 is pressed into the rear portion of the insertion hole 46, and a return spring 13 is provided between the receiving member 11 and the pressing member 12 in the insertion hole 46. The return spring 13 exerts a spring force in the direction of pressing the guide member 10 forward. Moreover, the insertion hole 46 of the receiving member 11
The set load of the return spring 13 can be adjusted by adjusting the press-fitting position along the axial direction of the return spring 13. Return spring 1
Even if the direction of the spring force acting on the pressing member 12 from 3 is a direction inclined with respect to the axis of the insertion hole 46, the pressing member 12 is formed with a semicircular distal end surface. The direction of the force acting on the guide member 10 from the member 12 can be adjusted to the direction along the axis of the third guide hole 44.

The guide member 10 is provided with a leak passage 48 extending from an outer surface of a fitting portion of the guide member 10 to the movable core 8 to a rear end of the guide member 10. This leak passage 4
Reference numeral 8 denotes an annular groove 48a formed annularly on the outer surface of the fitting portion of the movable core 8 into the first guide hole 42, and the annular groove 48a
The passage portion 48b extends along the axial direction of the guide member 10 from the portion corresponding to
And a passage 48c connecting the front end of the passage 48b and the annular groove 48a. Further, a leak hole 49 communicating with the leak passage 48 is provided at a front end of the pressing member 12 which contacts the rear end of the guide member 10.

On the inner surface of the valve body 9, the second communication hole 4 is sandwiched between the second communication hole 41 and the first guide hole 42.
Flat second valve seat 51 having a rear end opening at the center.
Is formed so as to face the rear side, and a valve portion 52 that can be seated on the second valve seat 51 is formed at the front end of the guide member 10.

By the way, the outer periphery of the rear end of the guide member 10 can come into contact with the regulating surface 45 provided on the fixed core 7, and the outer periphery of the rear end of the guide member 10 comes into contact with the regulating surface 45. The backward movement limit of the guide member 10 is restricted. In addition, the valve portion 52 is seated on the second valve seat 51 until the valve body 9 contacts the front end portion of the guide member 10 in a state where the outer periphery of the rear end portion of the guide member 10 is in contact with the regulating surface 45. The position of the regulating surface 45 is set such that when the movable core 8 moves rearward until a predetermined time elapses, a predetermined gap is formed between the rear end of the movable core 8 and the front end of the fixed core 7.

In such an electromagnetic fuel injection valve V,
The diameter D ₁ of the seat portion of the valve element 9 on the first valve seat 35, the diameter D ₂ of the fitting portion of the guide member 10 on the movable core 8, and the seating of the valve portion 52 on the second valve seat 51. The diameter D _{3 of the} portion is set to be substantially the same (D ₁ ≒ D ₂ ≒ D ₃ ).

Next, the operation of this embodiment will be described. In the demagnetized state of the coil 17, the guide member 10 causes the valve portion 52 to move the valve portion 52 to the second valve seat 51 by the spring force of the return spring 13.
The movable core 8 is pressed in a direction away from the fixed core 7, and the valve body 9 is seated on the first valve seat 35 by the spring force of the return spring 13. In this state, the space between the valve chamber 29 and the fuel storage chamber 36 is shut off, and the fuel injection holes 38
No fuel is injected from.

In such a valve closed state, the fuel pressure of the valve chamber 29 is set to an area obtained by subtracting the cross-sectional area of the guide member 10 from the movable core 8 from the maximum cross-sectional area of the movable core 8. The sum of the force obtained by the multiplication and the spring force of the return spring 13 acts in the direction in which the valve element 9 is seated on the first valve seat 35, and the first valve seat 35 The force obtained by multiplying the area obtained by subtracting the area of the seating portion of the valve body 9 from the fuel pressure in the valve chamber 29 acts in a direction to move the valve body 9 away from the first valve seat 35. However, the first valve seat 35
Since the diameter D ₁ of the seating portion of the valve body 9 and the diameter D ₂ of the fitting portion of the guide member 10 to the movable core 8 are set to be substantially the same, the valve body is provided on the first valve seat 35. The force for seating 9 is substantially only the spring force of the return spring 13.
That is, regardless of the fuel pressure in the valve chamber 29, the valve
It is the spring force of the return spring 13 that is seated on the valve seat 35 to maintain the closed state.

Therefore, the electromagnetic force required to operate the valve element 9 in the valve opening direction by energizing the coil 17 may be any value that can overcome the spring force of the return spring 13, and the fuel pressure is high. Even in this case, the valve can be opened with a relatively small electromagnetic force without being affected by the fuel pressure. As a result, it is not necessary to use an expensive material having a high magnetic flux density as a material for forming the fixed core 7, the movable core 8 and the housing 6, and it is not necessary to increase the number of turns and the wire diameter of the coil 17. The fuel injection valve V can be made compact and inexpensive.

When the valve body 9 is seated on the first valve seat 35,
For example, assuming that a high pressure from the cylinder side of the engine body acts on the fuel storage chamber 36 via the fuel injection holes 38, the rear end of the second communication hole 41 communicating with the fuel storage chamber 36 is opened at the center. At least the second
The valve seat 51 is seated the valve portion 52, the diameter D ₃ of the seating portion of the valve portion 52, it is substantially equal to the diameter D ₁ of the seat of the valve body 9 to the first valve seat 35 Therefore, the high pressure applied to the fuel storage chamber 36 from the cylinder side acts in a balanced manner before and after the valve body 9, and the valve body 9 and the movable core 8 are not operated to the valve opening side. The state in which the valve body 9 is seated on the first valve seat 35 is maintained. The high pressure acting from the cylinder side causes the valve portion 52 to move the second valve seat 5.
Even if the guide member 10 to be separated from 1 is large enough to move the guide member 10 rearward, the outer periphery of the rear end of the guide member 10 abuts on the regulating surface 45 to restrict the retreat limit of the guide member 10, The guide member 10 does not retreat more than necessary. Even if the guide member 10 retreats, the high pressure acts on the front and back of the valve body 9 in a balanced manner, so that the seating state of the valve body 9 on the first valve seat 35 is maintained.

In the closed state, the fuel in the valve chamber 29 is supplied to the movable core 8 and the guide member 1 directly fitted to the movable core 8.
0 flows into the small gap between the guide member 10
Passage 48 which is opened on the outer surface of the fitting portion to the movable core 8
Is provided in the guide member 10, the fuel flowing into the rear portion of the movable core 8 and between the guide members 10 flows from the leak passage 48 to the leak hole 49, the insertion hole 46, the cylindrical receiving member 11 and the release hole 47. The fuel leaks from the fuel tank 1 as shown in FIG.
Will be returned to. Therefore, it is not necessary to provide a seal member between the movable core 8 and the guide member 10 and the number of components is reduced, and high-pressure fuel can be prevented from leaking to the communication hole 40 side.

When the coil 17 is excited from the valve closed state in which the coil 17 is demagnetized, the movable core 8
The guide member 10, which is sucked to the side and seats the valve portion 52 on the second valve seat 51 provided in the valve body 9 integrated with the movable core 8, is also pushed rearward, and The guide member 10 is retracted until the outer periphery of the end comes into contact with the regulating surface 45 of the fixed core 7. At this time, the valve portion 52 of the guide member 10 in a state where the outer periphery of the rear end portion is in contact with the regulating surface 45
When the movable core 8 moves rearward until the second valve seat 51 of the valve body 9 abuts, a predetermined gap is created between the rear end of the movable core 8 and the front end of the fixed core 7. By setting the position of the regulating surface 45, the movable end of the movable core 8 is regulated by regulating the rearward moving end of the guide member 10.
Can be restricted from moving backward.

When the valve body 9 separates from the first valve seat 35 by the suction operation of the movable core 8 toward the fixed core 7, the valve chamber 2
9 communicates with the fuel storage chamber 36, and high-pressure fuel is injected from the fuel injection holes 38. At this time, each of the fuel injection holes 38 is provided in the hemispherical projection 37, and the position of each of the fuel injection holes 38 to the projection 37 is appropriately determined so that the electromagnetic fuel injection valve V The inclination angle of the fuel injection holes 38 with respect to the axis of the housing 6 can be appropriately set.

With the valve element 9 in the open state, the valve chamber 29
That is, the fuel pressure in the fuel storage chamber 36 is the first and the 27th.
It acts in a balanced manner before and after the valve element 9 via the through holes 40 and 41, so that the pressure balance between the valve element 9 and the movable core 8 is not lost. Moreover, since the valve portion 52 of the guide member 10 is seated on the second valve seat 51 provided in the valve body 9 when the valve body 9 is open, the communication hole 40 is provided between the guide member 10 and the movable core 8. It is possible to prevent fuel from leaking.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

For example, in the above embodiment, the valve body 9 is formed integrally with the movable core 8, but a valve body which is a member separate from the movable core may be fixed to the movable core. In the above embodiment, the case where the fuel pressure is high has been described.
It goes without saying that the present invention can be applied to an electromagnetic fuel injection valve for injecting fuel at a relatively low pressure.

[0041]

As described above, according to the first aspect of the present invention, the electromagnetic force necessary for operating the valve body in the valve opening direction by energizing the coil only overcomes the spring force of the return spring. The electromagnetic fuel injection valve can be made compact by opening the valve with relatively small electromagnetic force without being affected by the fuel pressure even if the fuel pressure is high. In a state where the valve body is seated on the valve seat and the valve body is in a state where the valve seat is separated from the valve body, the pressure is balanced between the front and rear of the valve body, and the valve is closed. And the valve opening state can be reliably maintained. In particular, open the rear end of the communication hole at the center of the valve body.
And a second valve seat facing the rear side is provided.
A valve part that can be seated on the seat is formed at the front end of the guide member
Therefore, the fuel between the guide member and the movable core
Can be prevented from leaking.

According to the second aspect of the present invention, it is not necessary to provide a seal member between the movable core and the guide member, so that the number of parts is reduced and the high-pressure fuel is prevented from leaking to the communication hole side. be able to.

According to the third aspect of the present invention, it is possible to limit the limit of the rearward movement of the guide member due to the high fuel pressure applied to the front end face of the guide member and the high pressure action from the cylinder side.

According to the fourth aspect of the present invention, the rearward movement end of the movable member can be restricted by the structure for restricting the rearward movement end of the guide member.

According to the fifth aspect of the present invention, in a state where the valve seat is separated from the valve body, the high-pressure fuel pressure is further balanced to act on the front and rear of the valve body, and the closed state of the valve is more reliably achieved. Can be maintained.

[Brief description of the drawings]

FIG. 1 is an overall longitudinal sectional view of an electromagnetic fuel injection valve.

FIG. 2 is an enlarged view of a main part of FIG. 1 in a valve open state.

[Explanation of symbols]

 5 ... Coil assembly 6 ... Housing 7 ... Fixed core 8 ... Movable core 9 ... Valve 10 ... Guide member 11 ... Receiving member 12 ... Pressing member 13. ..Return spring 16 ・ ・ ・ Bobbin 17 ・ ・ ・ Coil 20 ・ ・ ・ First storage hole 21 ・ ・ ・ Second storage hole 22 ・ ・ ・ End wall part 23 ・ ・ ・ Stepped part 29 ・ ・ ・ Valve chamber 34 ... Valve hole 35 ... Valve seat 36 ... Fuel reservoir 37 ... Protrusion 38 ... Fuel injection hole 39 ... Fuel inlet port 40,41 ... Communication hole 45 ... Regulating surface 48 ... leak passage 49 ... leak hole 51 ... second valve seat 52 ... valve portion V ... electromagnetic fuel injection valve

Claims (5)

(57) [Claims] 1. A coil assembly (5) in which a coil (17) is wound around a bobbin (16); a first storage hole (20) for storing the coil assembly (5), and a first storage hole. The second storage hole (21), which is formed smaller in diameter than (20) and is coaxially connected to the front end of the first storage hole (20) via the step (23), is connected to the front end of the second storage hole (21). The end hole (22) to be closed and the valve hole (3) coaxial with the second storage hole (21).
4) is opened at the center to form a valve seat (35) provided on the inner surface of the center portion of the end wall portion (22), and a fuel reservoir (36) connected to the valve hole (34) to form the end wall. Part (2
2) a hemispherical projection (37) projecting from the central outer surface,
A housing (6) made of a magnetic material having a fuel injection hole (38) formed in the projection (37) and a fuel inlet port (39) having an inner end opened in the inner surface of the second storage hole (21). A valve chamber (29) leading to the fuel inlet port (39) is formed between the end wall (22) and fitted to the bobbin (16) and a rear end of the housing (6). Cylindrical fixed core (7) joined to the part
And the valve chamber (2) facing the front end of the fixed core (7).
9) a movable core (8) housed in the valve seat (35);
Communication holes (40, 41) that are fixed to the front end of the movable core (8) so as to be able to be seated in the fuel reservoir chamber (36) and that extend through the front end of the movable core (8) in the axial direction of the valve hole (34). ) Is provided; a front portion in the axial direction is coaxially and slidably fitted to the movable core (8), and a front end is opposed to a rear end of the communication hole (40, 41). A guide member (10) having an axial rear portion slidably fitted to the fixed core (7); and a coaxial press-fit into the fixed core (7) behind the guide member (10). A receiving member (11); a pressing member (12) which comes into contact with a rear end of the guide member (10) and is axially movably inserted into the fixed core (7); and a movable core (8). The guide member (10) is urged in a direction to move it away from the fixed core (7). The end return is provided between the valve body (9) direction of the receiving member to exert a spring force (11) and said pressing member (12) to abut the spring (1
3), wherein the diameter of the seating portion of the valve body (9) on the valve seat (35) and the diameter of the fitting portion of the guide member (10) on the movable core (8) are substantially the same. It is set, the valve body (9), a rear end of the communication hole (40, 41)
Second valve seat (51) facing the rear side with opening at the center
A second valve seat (5) is provided at the front end of the guide member (10).
Seatable valve unit 1) (52), characterized in Rukoto is formed, the electromagnetic fuel injection valve. 2. A guide member (10) directly fitted to the movable core (8) and the fixed core (7) from an outer surface of a fitting portion of the guide member (10) to the movable core (8). The leak passage (4) reaching the rear end of the guide member (10)
8), a leak hole (49) leading to the leak passage (48) is provided in the pressing member (12), and the receiving member (11) is formed in a cylindrical shape. 2. The electromagnetic fuel injection valve according to 1. 3. The fixed core (7) is provided with a regulating surface (45) which abuts on a rear end outer peripheral portion of the guide member (10) and regulates a backward movement limit of the guide member (10). 3. The electromagnetic fuel injection valve according to claim 1, wherein: 4. The movable core (8) is moved backward until the valve body (9) comes into contact with the front end of the guide member (10) whose movement to the rear side is regulated by the regulating surface (45). The position of the regulating surface (45) is set so that a predetermined gap is created between the rear end of the movable core (8) and the front end of the fixed core (7) when the movable core moves to the side. The electromagnetic fuel injection valve according to claim 3, wherein Wherein said valve portion to the second valve seat (51) (5
The diameter of the seat 2) is, the guide member (10) electromagnetic fuel injection valve according to claim 1, characterized in that it is set substantially the same as the fitting portion diameter of the movable core (8) of .