JP4117487B2 - Fuel injection valve - Google Patents

Description

  The present invention relates to a fuel injection valve for an internal combustion engine (hereinafter, the internal combustion engine is referred to as an “engine”).

  Conventionally, a fuel injection valve that electromagnetically drives a movable part that opens and closes an injection hole is known. In the case of such a fuel injection valve, a magnetic attractive force is generated between the fixed core and the movable core of the movable portion that reciprocally moves opposite to the fixed core. The fixed core is fixed to the cylindrical member, while the movable portion is installed so as to be able to reciprocate inside the cylindrical member (see, for example, Patent Document 1). The distance between the opposed fixed core and the movable portion corresponds to the lift amount of the valve member. Therefore, in order to accurately set the fuel injection amount, it is necessary to precisely adjust the distance between the fixed core and the movable part.

JP 2003-166252 A

  The fixed core is fixed to the inside of the cylindrical member by press-fitting, for example. However, when the fixed core has a protruding portion that protrudes inward in the radial direction, the fixed core is more rigid in the portion where the protruding portion is formed than in other portions. Therefore, when the fixed core is press-fitted inside the cylinder member, the force required for press-fitting changes depending on the position of the fixed core, that is, the press-fitting amount of the fixed core, and the adjustment accuracy of the distance formed between the fixed core and the movable part Decreases. Moreover, when the force which press-fits a fixed core changes, abnormal contact with a fixed core and a cylindrical member will arise, and there exists a possibility of causing the generation | occurrence | production of a burr | flash and abrasion powder.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel injection valve that is highly accurate in adjusting the distance between a fixed core and a movable part and prevents the occurrence of burrs and wear.

  In the first aspect of the present invention, the fixed core forms a gap with the inner wall of the cylindrical member on the outer peripheral side of the protruding portion. Therefore, the fixed core has a protruding portion and a portion having a large rigidity does not come into contact with the cylindrical member. Thereby, the part with a large rigidity of a fixed core does not participate in press fit. Therefore, the accuracy of the distance between the fixed core and the movable part can be increased, and the generation of burrs and wear powder can be prevented.

  In the invention according to claim 2, the fixed core has a small-diameter portion on the outer peripheral side of the protruding portion. Therefore, a gap is formed between the small diameter portion of the fixed core and the cylindrical member. As a result, the protruding portion is formed and the portion having high rigidity does not contact the cylindrical member. Therefore, it is possible to improve the accuracy of the distance between the fixed core and the movable core, and it is possible to prevent the generation of burrs and wear powder.

In the invention according to claim 3, the outer diameter of the small diameter portion is substantially parallel to the inner wall of the cylindrical member. Therefore, a gap having a constant interval is formed in the axial direction between the fixed core and the cylindrical member. Therefore, the small diameter portion does not participate in the press-fitting of the fixed core, and the accuracy of the distance between the fixed core and the movable core can be improved.
In the invention according to claim 4, the distance between the outer wall and the inner wall of the cylindrical member increases as the small diameter portion moves away from the movable portion. Therefore, a gap is formed between the fixed core and the cylindrical member that expands as the distance from the injection hole increases. Therefore, the small diameter portion does not participate in the press-fitting of the fixed core, and the fixed core can be easily press-fitted into the cylindrical member.

  In the invention according to claim 5, the cylindrical member has an enlarged diameter portion on the outer peripheral side of the protruding portion of the fixed core. Therefore, a gap is formed between the fixed core and the enlarged diameter portion of the cylindrical member. As a result, the protruding portion is formed and the portion having high rigidity does not contact the cylindrical member. Therefore, it is possible to improve the accuracy of the distance between the fixed core and the movable core, and it is possible to prevent the generation of burrs and wear powder.

  In the invention according to claim 6, the fixed core has a locking portion in contact with the elastic member on the inner peripheral side of the small diameter portion. Thereby, the pressing force of the movable part is adjusted by the fixed core without using an adjusting member such as an adjusting pipe. Therefore, the pressing force of the elastic member can be precisely adjusted with a simple configuration without increasing the number of parts.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 shows a fuel injection valve (hereinafter referred to as “injector”) according to a first embodiment of the present invention. The injector 10 according to the first embodiment injects fuel into, for example, intake air sucked into a combustion chamber of a gasoline engine. The injector 10 may be applied to a direct-injection gasoline engine or a diesel engine that directly injects fuel into the combustion chamber of the gasoline engine.

  The accommodating pipe 11 as a cylindrical member of the injector 10 is formed in a thin, substantially cylindrical shape. The accommodation pipe 11 has a first magnetic part 12, a nonmagnetic part 13, and a second magnetic part 14. The nonmagnetic part 13 prevents a magnetic short circuit between the first magnetic part 12 and the second magnetic part 14. The first magnetic part 12 and the nonmagnetic part 13, and the nonmagnetic part 13 and the second magnetic part 14 are integrally connected, for example, by laser welding. The housing pipe 11 may be integrally formed of a magnetic material, and a portion corresponding to the nonmagnetic portion 13 may be made nonmagnetic by thermal processing or the like. The housing pipe 11 has a fuel inlet 15 at one end in the axial direction. The fuel inlet 15 is supplied with fuel from a fuel pump (not shown). The fuel supplied to the fuel inlet 15 flows into the inner peripheral side of the accommodation pipe 11 via the fuel filter 16. The fuel filter 16 is installed at the end of the accommodation pipe 11 and removes foreign matters contained in the fuel.

  A valve body 20 is installed at the end of the housing pipe 11 opposite to the fuel inlet 15, that is, at the inner peripheral side of the first magnetic part 12. The valve body 20 is formed in a substantially cylindrical shape and is fixed to the inner peripheral side of the first magnetic part 12. The valve body 20 has a valve seat 21 on a conical inner wall whose inner diameter decreases as it approaches the tip. The valve body 20 has a nozzle hole plate 22 at the end opposite to the housing pipe 11. The nozzle hole plate 22 has a nozzle hole 23 that connects an end face on the valve body 20 side and an end face on the opposite side of the valve body 20.

  The needle 24 as a valve member is accommodated on the inner peripheral side of the first magnetic part 12 and the valve body 20 so as to be capable of reciprocating in the axial direction. The needle 24 is disposed substantially coaxially with the accommodating pipe 11 and the valve body 20. The needle 24 has a seal portion 25 in the vicinity of the end portion on the nozzle hole plate 22 side. The seal portion 25 can contact a valve seat 21 formed on the valve body 20. The needle 24 forms a fuel passage 26 through which fuel flows between the needle body 24 and the valve body 20. The fuel passage 26 is connected to the injection hole 23 when the seal portion 25 of the needle 24 is separated from the valve seat 21.

  The injector 10 has a drive unit 30 that drives the needle 24. The drive unit 30 is an electromagnetic drive unit and includes a coil 31, a housing 32, a movable core 33, and a fixed core 40. The coil 31 is wound around a spool 34 that is formed of resin in a cylindrical shape. The housing 32 is made of a magnetic material and covers the outer peripheral side of the coil 31. The outer periphery side of the coil 31 and the housing 32 and the accommodation pipe 11 is covered with a resin mold 35. The coil 31 is electrically connected to a terminal 38 installed in the connector 37 via the wiring member 36. The connector 37 is formed integrally with the resin mold 35.

  The movable core 33 is installed on the inner peripheral side of the accommodating pipe 11 so as to be reciprocally movable in the axial direction. The movable core 33 is opposed to the fixed core 40 at the end opposite to the injection hole 23. The outer wall of the movable core 33 is slidable with the inner wall of the receiving pipe 11. Thereby, the movable core 33 is guided by the inner wall of the accommodation pipe 11 and reciprocates in the axial direction. The movable core 33 is formed in a substantially cylindrical shape from a magnetic material such as iron. The movable core 33 has a hole portion 331 to which an end portion of the needle 24 opposite to the seal portion 25 is fixed. The needle 24 is fixed to the hole 331 of the movable core 33 by, for example, press fitting or welding. Thereby, the needle 24 and the movable core 33 constitute a movable part that reciprocally moves in the axial direction integrally. The movable core 33 has a fuel hole 332 that connects the hole 331 and the fuel passage 26.

  The movable core 33 is in contact with a spring 39 as an elastic member at the end opposite to the injection hole 23. The spring 39 has one end in contact with the movable core 33 and the other end in contact with the fixed core 40. The spring 39 has a force extending in the axial direction. Therefore, the needle 24 integrated with the movable core 33 is pressed by the spring 39 in the direction of seating on the valve seat 21, that is, in the direction of the injection hole 23.

  The fixed core 40 is fixed to the inner peripheral side of the coil 31 with the accommodation pipe 11 interposed therebetween. The fixed core 40 is formed in a substantially cylindrical shape by a magnetic material such as iron. The fixed core 40 forms a gap with a distance g between the fixed core 40 and the movable core 33. The distance g between the fixed core 40 and the movable core 33 corresponds to the lift amount of the needle 24. The fixed core 40 is formed in a cup shape having a cylindrical portion 41 and a bottom portion 42 as shown in FIG. The cylinder portion 41 extends in the axial direction, and the outer wall is in contact with the inner wall of the housing pipe 11. The fixed core 40 has a small diameter portion 43 on the opposite side of the cylindrical portion 41 from the movable core 33. The small diameter portion 43 is formed to have an outer diameter smaller than that of the cylindrical portion 41. The bottom portion 42 protrudes radially inward from the end of the small diameter portion 43 opposite to the movable core 33. The bottom 42 has a hole 44 at the center in the radial direction. The hole 44 is connected to the inner peripheral side of the small diameter part 43 and the cylinder part 41, and the fuel passes therethrough. The other end of the spring 39, that is, the end opposite to the movable core 33 is in direct contact with the bottom 42 of the fixed core 40. Thereby, the bottom part 42 of the fixed core 40 comprises the latching | locking part of a claim. The radially inner end of the bottom portion 42 is bent in the direction of the movable core 33 as shown in the broken line in FIG. 2 and FIG.

  By installing the small diameter portion 43 in the fixed core 40, a gap 17 is formed between the outer wall of the fixed core 40 and the inner wall of the accommodation pipe 11. The small-diameter portion 43 has an outer wall that is substantially parallel to the inner wall of the housing pipe 11, that is, the outer wall and the inner wall of the housing pipe 11 are formed concentrically. The small diameter portion 43 is formed with a predetermined length in the axial direction. Therefore, the small diameter part 43 and the accommodation pipe 11 form the gap 17 in a predetermined range in the axial direction. X ≧ t, where t is the thickness of the bottom portion 42 and x is the total axial length of the small diameter portion 43. Thereby, the small diameter part 43 is located at least on the radially outer side of the bottom part 42. Accordingly, the gap 17 is arranged between the bottom portion 42 and the accommodation pipe 11.

  When the injector 10 is assembled, first, the integral needle 24 and the movable core 33 constituting the movable portion are installed on the inner peripheral side of the housing pipe 11. When the integral needle 24 and the movable core 33 are installed, a spring 39 is installed on the opposite side of the movable core 33 from the needle 24. At this time, the spring 39 is neither compressed nor stretched and has an original full length. When the spring 39 is installed, the fixed core 40 is installed on the opposite side of the spring 39 from the movable core 33. Accordingly, one end of the spring 39 is in contact with the movable core 33, and the other end is in contact with the bottom 42 of the fixed core 40. Then, the fixed core 40 is press-fitted into the accommodating pipe 11 in the direction of the movable core 33. By press-fitting the fixed core 40, the spring 39 in contact with the bottom 42 of the fixed core 40 is compressed.

  The fixed core 40 has a small diameter portion 43 on the opposite side of the cylindrical portion 41 from the movable core 33. Further, the bottom portion 42 protrudes radially inward from the small diameter portion 43. Therefore, when the fixed core 40 is press-fitted into the accommodation pipe 11, only the cylindrical portion 41 of the fixed core 40 is press-fitted into the accommodation pipe 11. That is, the small-diameter portion 43 does not participate in press fitting because it does not contact the accommodation pipe 11.

  By the way, by forming the bottom portion 42 that protrudes radially inward in the fixed core 40, the rigidity of the fixed core 40 is larger than that of the other portion, that is, the cylinder portion 41, at the position where the bottom portion 42 is formed. Therefore, when the small-diameter portion 43 is not formed, when the portion corresponding to the bottom portion 42 is press-fitted, the force necessary for press-fitting the fixed core 40 is larger than the force necessary for press-fitting the cylindrical portion 41. As a result, the force for press-fitting the fixed core 40 varies depending on the position of the fixed core 40, that is, the press-fitting amount.

  On the other hand, in this embodiment, although the bottom part 42 protrudes from the small diameter part 43, the small diameter part 43 does not participate in the press-fitting of the fixed core 40 as described above. Therefore, in the fixed core 40, only the cylindrical portion 41 having a constant thickness is press-fitted into the accommodation pipe 11. As a result, the force for press-fitting the fixed core 40 does not change depending on the press-fit amount of the fixed core 40. Thereby, the fixed core 40 is press-fitted into the receiving pipe 11 by applying a certain force.

  The fixed core 40 is press-fitted until a gap formed between the fixed core 40 and the movable core 33 reaches a distance g. When the press-fitting of the fixed core 40 is completed, the bottom portion 42 of the fixed core 40 is bent toward the movable core 33 as shown by the broken line in FIG. 2 and FIG. Thereby, the total length of the spring 39 is adjusted precisely, and the load of the spring 39, that is, the force pressing the integral needle 24 and the movable core 33 is adjusted.

Next, the operation of the injector 10 having the above configuration will be described.
When energization of the coil 31 is stopped, no magnetic attractive force is generated between the fixed core 40 and the movable core 33. Therefore, the movable core 33 moves to the opposite side of the fixed core 40 by the pressing force of the spring 39, and the needle 24 integrated with the movable core 33 also moves to the opposite side of the fixed core 40. As a result, when energization to the coil 31 is stopped, the seal portion 25 of the needle 24 is seated on the valve seat 21. Therefore, fuel is not injected from the injection hole 23.

  When the coil 31 is energized, a magnetic circuit is formed in the housing 32, the first magnetic part 12, the movable core 33, the fixed core 40, and the second magnetic part 14 by a magnetic field generated in the coil 31, and a magnetic flux flows. As a result, a magnetic attractive force is generated between the fixed core 40 and the movable core 33 that are separated from each other by the pressing force of the spring 39 by energizing the coil 31. When the magnetic attractive force generated between the fixed core 40 and the movable core 33 becomes larger than the pressing force of the spring 39, the integral movable core 33 and the needle 24 move toward the fixed core 40. Thereby, the seal portion 25 of the needle 24 is separated from the valve seat 21. The integral movable core 33 and the needle 24 move upward in FIG. 1 until the movable core 33 contacts the fixed core 40.

  The fuel that flows into the injector 10 from the fuel inlet 15 passes through the fuel filter 16, the inner peripheral side of the accommodating pipe 11, the inner peripheral side of the fixed core 40, the hole 331 and the fuel hole 332 of the movable core 33, and the accommodating pipe 11. Flows into the fuel passage 26 via the space between the needle 24 and the needle 24. The fuel that has flowed into the fuel passage 26 flows into the nozzle hole 23 formed by the nozzle hole plate 22 via the space between the needle 24 separated from the valve seat 21 and the valve body 20. Thereby, fuel is injected from the injection hole 23.

  When energization of the coil 31 is stopped, the magnetic attractive force between the fixed core 40 and the movable core 33 disappears. As a result, the movable core 33 integral with the needle 24 moves to the opposite side of the fixed core 40 by the pressing force of the spring 39. Therefore, the seal portion 25 is seated on the valve seat 21 again, and the fuel flow between the fuel passage 26 and the injection hole 23 is blocked. Therefore, the fuel injection ends.

  As described above, in the first embodiment, the bottom portion 42 of the fixed core 40 is formed to protrude radially inward from the small diameter portion 43. Therefore, when the fixed core 40 is press-fitted into the accommodation pipe 11, only the cylinder portion 41 is involved in the press-fitting into the accommodation pipe 11, and the small diameter portion 43 is not involved in the press-fitting. As a result, the small-diameter portion 43 whose rigidity is increased by the protruding bottom portion 42 is not press-fitted into the accommodation pipe 11. Thereby, the force required to press-fit the fixed core 40 into the housing pipe 11 is constant regardless of the press-fit amount of the fixed core 40. Therefore, the distance g of the gap formed between the fixed core 40 and the movable core 33 can be set with high accuracy. Further, the force applied to the fixed core 40 does not change when the fixed core 40 is press-fitted. Therefore, abnormal contact between the fixed core 40 and the accommodation pipe 11 is prevented. Therefore, occurrence of burrs and wear can be prevented.

  In the first embodiment, the fixed core 40 is a locking portion in which the bottom portion 42 protruding radially inward from the small diameter portion 43 is in contact with the spring. In other words, the spring 39 that presses the integral needle 24 and the movable core 33 is in direct contact with the fixed core 40 at the end opposite to the movable core 33. Then, the load of the spring 39 is adjusted by bending the bottom portion 42 of the fixed core 40, that is, by causing plastic deformation. Therefore, a separate member for adjusting the load of the spring 39 is not required. Therefore, the number of parts can be reduced and the structure can be simplified. Further, by adjusting the load of the spring 39 by plastic deformation of the bottom portion 42 of the fixed core 40, the load of the spring 39 can be accurately changed according to the deformation amount of the bottom portion 42. Therefore, the load of the spring 39 can be easily and precisely adjusted to a predetermined value regardless of the tolerance of the member.

(Second Embodiment)
The fixed core of the injector according to the second embodiment of the present invention is shown in FIG. In addition, the same code | symbol is attached | subjected to the component substantially the same as 1st Embodiment, and description is abbreviate | omitted.
In the second embodiment, as shown in FIG. 3, the fixed core 50 has a tapered portion 52 having an outer diameter smaller than that of the cylindrical portion 51 at the end of the cylindrical portion 51 opposite to the movable core 33. The tapered portion 52 is inclined radially inwardly away from the movable core 33 at the end of the fixed core 50 opposite to the movable core 33. As a result, the distance between the outer wall of the tapered portion 52 of the fixed core 50 and the inner wall of the housing pipe 11 increases as the distance from the movable core 33 increases. The thickness t of the tapered portion 52 is set to t ≦ 1 / 2h, where h is the thickness of the cylindrical portion 51. Thereby, the taper part 52 becomes smaller in rigidity than the cylinder part 51.

  By installing the tapered portion 52 on the fixed core 50, a gap 17 is formed between the outer wall of the tapered portion 52 and the inner wall of the receiving pipe 11. The outer wall of the taper portion 52 and the inner wall of the housing pipe 11 form a predetermined angle. The tapered portion 52 is formed with a predetermined length in the axial direction. Therefore, the taper part 52 and the accommodation pipe 11 form the gap 17 in a predetermined range in the axial direction. Further, since the tapered portion 52 is inclined, the gap 17 is expanded in the radial direction as the distance from the movable core 33 increases. Further, when the tapered portion 52 is inclined radially inward, the tapered portion 52 protrudes radially inward from the tubular portion 51. Accordingly, the tapered portion 52 constitutes a small diameter portion that forms the gap 17 between the accommodating pipe 11 and a protruding portion that protrudes from the cylindrical portion 51. Further, the end of the spring 39 opposite to the movable core 33 is in contact with the inner wall of the tapered portion 52. Thereby, the taper part 52 comprises a latching | locking part.

  In the present embodiment, when the load of the spring 39 is adjusted, the tapered portion 52 is plastically deformed by being squeezed radially inward as indicated by the broken line in FIG. As the tapered portion 52 is narrowed inward in the radial direction, the end portion of the spring 39 in contact with the tapered portion 52 moves toward the movable core 33. As a result, the overall length of the spring 39 changes, and the load of the spring 39 is adjusted precisely and easily.

  In the second embodiment, the tapered portion 52 of the fixed core 50 has a smaller outer diameter than the cylindrical portion 51, so that it does not contact the accommodation pipe 11. Therefore, only the cylinder portion 51 is involved in press fitting, and the tapered portion 52 is not involved in press fitting. Thereby, only the cylinder part 51 with a fixed thickness is press-fitted into the accommodation pipe 11 in the fixed core 50. Therefore, the force applied when the fixed core 50 is press-fitted can be made constant, and the accuracy of the distance g between the fixed core 50 and the movable core 33 can be increased. Furthermore, in the second embodiment, when the fixed core 50 is press-fitted into the accommodation pipe 11, a force for press-fitting is applied to the step 53 between the cylindrical portion 51 and the tapered portion 52. Thereby, the position where the force is applied when the fixed core 50 is press-fitted becomes the step 53, and the position where the force is applied to adjust the load of the spring 39 becomes the tapered portion 52. As a result, the position where the force is applied is different, and movement of the fixed core 50 when the tapered portion 52 is deformed or unnecessary deformation of the tapered portion 52 when press-fitting is prevented. Therefore, the accuracy of the position of the fixed core 50 and the accuracy of the distance g between the fixed core 50 and the movable core 33 can be increased.

(Third, fourth and fifth embodiments)
The fixed core of the injector according to the third, fourth and fifth embodiments of the present invention is shown in FIG. 4, FIG. 5 or FIG. 6, respectively. In addition, the same code | symbol is attached | subjected to the component substantially the same as 1st Embodiment, and description is abbreviate | omitted.
In 3rd, 4th and 5th embodiment, in order to form a clearance gap between the fixed core 40 and the accommodation pipe 11, it has an enlarged diameter part for forming a clearance gap in the accommodation pipe 11 side, respectively.
In the case of the third embodiment, the accommodation pipe 11 has a large-diameter portion 11 a as an enlarged-diameter portion on the outer peripheral side of the bottom portion 42 of the fixed core 40. The large-diameter portion 11a has a larger inner diameter than the portion that contacts the cylindrical portion 41 of the fixed core 40. Thereby, a gap 17 is formed between the outer wall of the fixed core 40 and the inner wall of the housing pipe 11 in the large diameter portion 11 a of the housing pipe 11.

In the case of the fourth embodiment, the accommodation pipe 11 has a tapered portion 11 b as an enlarged diameter portion on the outer peripheral side of the bottom portion 42 of the fixed core 40. The taper portion 11b has an inner diameter that increases from the portion in contact with the cylindrical portion 41 of the fixed core 40 toward the fuel inlet 15 side. Accordingly, a gap 17 is formed between the outer wall of the fixed core 40 and the inner wall of the housing pipe 11 at the tapered portion 11 b of the housing pipe 11.
In the case of the fifth embodiment, the accommodation pipe 11 has a concave portion 11 c as an enlarged diameter portion on the outer peripheral side of the bottom portion 42 of the fixed core 40. The recess 11 c is formed continuously in the circumferential direction of the accommodation pipe 11. The concave portion 11 c has an inner diameter larger than that of the portion that contacts the cylindrical portion 41 of the fixed core 40. That is, the concave portion 11 c is recessed outward in the radial direction of the housing pipe 11 from the portion that contacts the cylindrical portion 41 of the fixed core 40. Thereby, a gap 17 is formed between the outer wall of the fixed core 40 and the inner wall of the receiving pipe 11 in the recess 11 c of the receiving pipe 11.

  In each of the third, fourth, and fifth embodiments, a gap 17 is formed between the accommodation pipe 11 and the fixed core 40 by forming the large-diameter portion 11a, the tapered portion 11b, or the recess 11c in the accommodation pipe 11. is doing. That is, in order to form the gap 17, not only the fixed core 40 but also the accommodation pipe 11 may be processed. Even in these cases, the outer peripheral side of the bottom 42 of the fixed core 40 does not contact the accommodation pipe 11. Therefore, only the cylinder part 41 is involved in press-fitting, and the outer peripheral side of the bottom part 42 is not involved in press-fitting. As a result, only the cylindrical portion 41 of the fixed core 40 is press-fitted into the accommodation pipe 11. Therefore, the force applied when the fixed core 40 is press-fitted can be made constant, and the accuracy of the distance between the fixed core 40 and the movable core 33 can be increased.

  As described above, in the plurality of embodiments described above, the example in which the movable portion is configured by the separate movable core 33 and the needle 24 has been described. However, the movable core 33 and the needle 24 may be configured integrally. Moreover, although several embodiment demonstrated the example which attaches the nozzle hole plate 22 which forms the nozzle hole 23 to the valve body 20, you may form a nozzle hole in the valve body 20 directly. Further, in the embodiments, the example in which the spring 39 and the fixed core or the movable core are in direct contact with each other has been described. However, another member may be provided between the spring 39 and the fixed core or the movable core. Further, in the plurality of embodiments, the accommodation pipe 11 has been described as an example in which a magnetic circuit is configured by a magnetic field generated in the coil 31. However, the accommodation pipe 11 is not limited to a member that can constitute a magnetic circuit, and any member that can accommodate a fixed core can be applied.

It is sectional drawing which shows the injector by 1st Embodiment of this invention. It is sectional drawing which shows the periphery of the fixed core and storage pipe of the injector by 1st Embodiment of this invention. It is sectional drawing which shows the periphery of the fixed core and accommodating pipe | tube of an injector by 2nd Embodiment of this invention. It is sectional drawing which shows the periphery of the fixed core of the injector by the 3rd Embodiment of this invention, and an accommodation pipe. It is sectional drawing which shows the periphery of the fixed core and storage pipe of the injector by 4th Embodiment of this invention. It is sectional drawing which shows the periphery of the fixed core and accommodating pipe of the injector by 5th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Injector (fuel injection valve), 11 Accommodation pipe (cylindrical member), 11a Large diameter part (expanded diameter part), 11b Tapered part (expanded diameter part), 11c Recessed part (expanded diameter part), 17 Clearance, 23 Injection hole, 24 Needle (movable part), 26 Fuel passage, 31 Coil, 33 Movable core (movable part), 39 Spring (elastic member), 40 Fixed core, 42 Bottom part (protrusion part, locking part), 43 Small diameter part, 50 Fixed Core, 52 taper part (protrusion part, small diameter part, locking part)

Claims (6)

A tubular member,
A movable part that is installed on the inner peripheral side of the cylindrical member, reciprocates in the axial direction of the cylindrical member, and opens and closes a fuel passage communicating with the nozzle hole;
A magnetic attraction force for attracting the movable part between the movable part and the movable part when the coil is energized is installed on the inner peripheral side of the cylindrical member opposite to the end of the movable part opposite to the nozzle hole. The generated fixed core,
Formed at the end of the fixed core on the side opposite to the movable part side, and provided with a protruding portion protruding radially inward from the fixed core,
A fuel injection valve characterized in that a gap is formed between at least a portion of the outer peripheral surface of the fixed core located radially outside the protruding portion and the inner wall of the cylindrical member.   The fuel injection valve according to claim 1, wherein the fixed core has a small-diameter portion that forms the gap on an outer peripheral side of the protruding portion.   The fuel injection valve according to claim 2, wherein the small diameter portion has an outer wall substantially parallel to an inner wall of the cylindrical member. A tubular member,
A movable part that is installed on the inner peripheral side of the cylindrical member, reciprocates in the axial direction of the cylindrical member, and opens and closes a fuel passage communicating with the nozzle hole;
A magnetic attraction force for attracting the movable part between the movable part and the movable part when the coil is energized is installed on the inner peripheral side of the cylindrical member opposite to the end of the movable part opposite to the nozzle hole. The generated fixed core,
A projecting portion projecting radially inward from the fixed core,
The fixed core has a small-diameter portion that forms a gap between at least a portion of the outer peripheral surface located on the radially outer side of the protruding portion and the inner wall of the cylindrical member,
The fuel injection valve according to claim 1, wherein the small-diameter portion has a shape that increases a distance between an outer wall and the inner wall of the cylindrical member as the distance from the movable portion increases. A tubular member,
A movable part that is installed on the inner peripheral side of the cylindrical member, reciprocates in the axial direction of the cylindrical member, and opens and closes a fuel passage communicating with the nozzle hole;
A magnetic attraction force for attracting the movable part between the movable part and the movable part when the coil is energized is installed on the inner peripheral side of the cylindrical member opposite to the end of the movable part opposite to the nozzle hole. The generated fixed core,
A projecting portion projecting radially inward from the fixed core,
The cylinder member has a diameter-enlarged portion that forms a gap between at least a portion of the outer peripheral surface of the fixed core that is located on the radially outer side of the protruding portion and an inner wall of the cylinder member. Injection valve.
An elastic member that presses the movable part and the fixed core away from each other;
6. The fuel injection valve according to claim 1, wherein the protruding portion engages an end portion of the elastic member opposite to the movable portion.

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