JP2016125360A - Fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection valve which increase force in an open-valve direction acting on a needle, and can reduce a wear of a moving core.SOLUTION: A needle 40 for opening/closing an injection hole of a fuel injection valve 1 has a collar portion 43 collided with a moving core 50 during valve-opening. A clearance forming member 60 is provided on the outside in a diametrical direction of the collar portion 43, which forms a clearance 430 between the moving core 50 and the collar portion 43 during the valve-closing. When the moving core 50 moves in a valve-opening direction while accelerating and collides to the collar portion 43, comparatively large valve opening force is acted on the needle 40. The clearance forming member 60 slides with the collar portion 43 and a fixed core 30, and the reciprocating movement of the needle 40 is guided to the fixed core 30 through the clearance forming member 60. The reciprocating movement of the moving core 50 into which the needle 40 is inserted is guided to the fixed core 30 through the needle 40 and the clearance forming member 60. At that time, a clearance 200 is formed between an outer wall 505 of the moving core 50 and a housing 20.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fuel injection valve for injecting and supplying fuel to an internal combustion engine (hereinafter referred to as “engine”).

  2. Description of the Related Art Conventionally, a fuel injection valve that opens and closes a nozzle hole of a housing by reciprocating movement of a needle and injects fuel in the housing to the outside is known. For example, in Patent Document 1, a coil, a fixed core provided inside the coil, a movable core provided on the injection hole side of the fixed core, a needle provided separately from the movable core, the movable core and the needle in the valve closing direction There is described a fuel injection valve that includes a spring that biases the valve and that forms a gap between a stopper and a movable core that the needle has when the needle is in contact with a valve seat.

Japanese Patent No. 4637930

  In the fuel injection valve described in Patent Document 1, when the movable core is attracted to the fixed core by the magnetic field formed by the coil, the movable core is accelerated using the gap between the needle stopper and the movable core. After moving in the valve opening direction, it collides with the stopper of the needle. As a result, in the fuel injection valve described in Patent Document 1, the force in the valve opening direction acting on the needle (hereinafter referred to as “valve opening force”) becomes relatively large. However, in the fuel injection valve described in Patent Document 1, the movable core collides with the stopper of the needle while the outer wall slides on the inner wall of the housing and the inner wall slides on the outer wall of the needle. When accelerating by using, frictional resistance due to sliding with the inner wall of the housing and sliding with the outer wall of the needle acts on the movable core. For this reason, it may be difficult to increase the valve opening force.

  Further, in the fuel injection valve disclosed in Patent Document 1, since the outer wall of the movable core slides with the inner wall of the housing, the outer wall of the movable core may be worn by sliding. When the movable core is worn, there is a possibility that the suction characteristics of the movable core may change, or wear powder generated by the wear of the movable core may be caught between the needle and the valve seat. Further, the needle is unstable in the reciprocating movement of the needle because the intermediate portion of the needle located on the nozzle hole side from the end opposite to the nozzle hole and the end on the nozzle hole slide in the housing. There is a risk of becoming.

  An object of the present invention is to provide a fuel injection valve capable of increasing the force in the valve opening direction acting on the needle and reducing the wear of the movable core.

The present invention relates to a fuel injection valve, a housing having an injection hole through which fuel is injected and a valve seat formed around the injection hole, and a housing that is accommodated in the housing so as to be reciprocally movable, or is separated from the valve seat A needle part that opens and closes the nozzle hole when in contact with the needle part, a flange part provided on the radially outer side of the end part opposite to the end part capable of contacting the valve seat of the needle part, and a cylinder fixed in the housing A fixed core, and an insertion hole that is provided on the nozzle hole side of the fixed core and through which the needle part is inserted. A movable core slidable with the outer wall, a coil capable of attracting the movable core to the fixed core side when electric power is supplied, an inner wall slides with the outer wall of the buttocks, and an outer wall can slide with the inner wall of the fixed core A second gap is provided between the collar and the movable core. A gap forming member capable of being formed, a first biasing member capable of biasing the movable core in the valve closing direction via the gap forming member and biasing the needle portion in the valve closing direction via the collar portion, A second urging member that urges the movable core in the valve opening direction with an urging force smaller than the urging force of the urging member.
In the fuel injection valve of the present invention, when the needle portion and the valve seat are in contact with each other, and the first biasing member biases the needle portion and the gap forming member in the valve closing direction, the nozzle hole side of the collar portion A second gap is formed between the end face of the movable core and the end face on the side opposite to the nozzle hole of the movable core.

  In the fuel injection valve of the present invention, the gap forming member forms a second gap between the flange portion and the movable core. When electric power is supplied to the coil and the movable core is attracted to the fixed core, the movable core moves while accelerating in the valve opening direction using the gap, and comes into contact with the flange. Thereby, a comparatively big valve opening force can be made to act on the needle part provided in the radial inside of the collar part.

  In the fuel injection valve of the present invention, the gap forming member slides on the outer wall of the flange and the inner wall of the fixed core. Thereby, the needle part in which the collar part is provided on the radially outer side is guided to the fixed core via the gap forming member. Further, the movable core having the insertion hole slides on the outer wall of the needle part inserted through the insertion hole, and the reciprocating movement of the movable core in the housing is guided by the needle part. Further, a first gap is formed between the outer wall of the movable core and the inner wall of the housing. Thereby, compared with the case where the reciprocating movement of the movable core in the housing is guided by the housing, the frictional resistance acting on the movable core is reduced. Therefore, it is possible to prevent the moving speed of the movable core in the valve opening direction from being slowed by the frictional resistance, and to further increase the valve opening force.

  Further, in the fuel injection valve of the present invention, since the first gap is formed between the outer wall of the movable core and the inner wall of the housing, it is possible to reduce wear on the outer wall of the movable core. As a result, the suction characteristics between the movable core and the fixed core change due to wear of the outer wall of the movable core, or wear powder generated by wear of the outer wall of the movable core is caught between the needle and the valve seat. Can be prevented.

  In the fuel injection valve of the present invention, the needle portion is guided to reciprocate by the fixed core at the end portion on the side where the collar portion of the needle portion is provided via the gap forming member. Thereby, the needle part can stably reciprocate within the housing.

It is sectional drawing of the fuel injection valve by 1st embodiment of this invention. It is the II section enlarged view of FIG. It is sectional drawing explaining the effect | action of the fuel injection valve by 1st embodiment of this invention. It is sectional drawing explaining the effect | action of the fuel injection valve by 1st embodiment of this invention, Comprising: It is sectional drawing explaining the effect | action different from FIG. It is sectional drawing of the fuel injection valve by 2nd embodiment of this invention. It is sectional drawing of the fuel injection valve by 3rd embodiment of this invention. It is sectional drawing of the fuel injection valve by 4th embodiment of this invention.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
1 to 4 show a fuel injection valve 1 according to a first embodiment of the present invention. 1 to 4 illustrate a valve opening direction in which the needle 40 is separated from the valve seat 250 and a valve closing direction in which the needle 40 is in contact with the valve seat 250.

  The fuel injection valve 1 is used, for example, in a fuel injection device of a direct injection gasoline engine (not shown), and injects and supplies gasoline as fuel to the engine at a high pressure. The fuel injection valve 1 includes a housing 20, a needle 40, a movable core 50, a fixed core 30, a gap forming member 60, a coil 35, a first spring 31 as a “first urging member”, and a “second urging member”. The second spring 32 is provided.

  As shown in FIG. 1, the housing 20 includes a first cylinder member 21, a second cylinder member 22, a third cylinder member 23, and an injection nozzle 25. The first cylinder member 21, the second cylinder member 22, and the third cylinder member 23 are all formed in a cylindrical shape, and are coaxial in the order of the first cylinder member 21, the second cylinder member 22, and the third cylinder member 23. Arranged and connected to each other.

  The injection nozzle 25 is provided at the end of the first cylinder member 21 opposite to the second cylinder member 22. The injection nozzle 25 is formed in a bottomed cylindrical shape from a metal such as martensitic stainless steel, and is welded to the first cylindrical member 21. The injection nozzle 25 is subjected to a quenching process so as to have a predetermined hardness.

  The injection nozzle 25 is formed in line symmetry with the central axis CA0 of the housing 20 as an axis of symmetry. The injection nozzle 25 has a plurality of injection holes 26 that communicate the inside and the outside of the housing 20. A valve seat 250 is formed at the edge of the inner opening of the nozzle hole.

  The needle 40 is made of a metal such as martensitic stainless steel. The needle 40 is subjected to a quenching process so as to have a hardness comparable to that of the injection nozzle 25.

  The needle 40 is accommodated inside the housing 20 so as to be reciprocally movable. The needle 40 includes a shaft portion 41, a seal portion 42 as “an end portion capable of contacting the valve seat of the needle portion”, a sliding contact portion 44, a flange portion 43, and the like. The shaft portion 41, the seal portion 42, the slidable contact portion 44, and the flange portion 43 are integrally formed. The shaft portion 41, the seal portion 42, and the sliding contact portion 44 correspond to a “needle portion” described in the claims.

  The shaft portion 41 is a rod-shaped portion in which the end portion on the fixed core 30 side is formed in a cylindrical shape. The end portion of the shaft portion 41 on the fixed core 30 side has a flow path 400 through which fuel flows toward the inside of the injection nozzle 25. The channel 400 communicates with a hole 411 included in the shaft portion 41 on the nozzle hole 26 side of the channel 400. That is, the hole 411 communicates the flow path 400 and the outside of the shaft portion 41.

  The seal portion 42 is provided at the end portion of the shaft portion 41 on the nozzle hole 26 side so as to be able to contact the valve seat 250. The needle 40 opens and closes the nozzle hole 26 when the seal portion 42 is separated from the valve seat 250 or abuts against the valve seat 250, and communicates or blocks the inner side and the outer side of the housing 20.

  A slidable contact portion 44 is provided between the shaft portion 41 and the seal portion 42. The sliding contact portion 44 is formed in a cylindrical shape, and a part of the outer wall 441 is chamfered. The slidable contact portion 44 can be slidably contacted with the inner wall of the injection nozzle 25 at a portion of the outer wall 441 that is not chamfered. Thereby, the needle 40 is guided to reciprocate at the end portion on the nozzle hole 26 side.

  The flange portion 43 is formed in a substantially annular shape, and is provided on the radially outer side of the end portion of the shaft portion 41 opposite to the side where the seal portion 42 is provided. The outer diameter of the flange portion 43 is larger than the outer diameter of the shaft portion 41. The outer edge portion 433 of the flange portion 43 opposite to the injection hole 26 is formed so that the outer diameter decreases from the injection hole 26 side toward the opposite side of the injection hole 26.

  The movable core 50 is formed in a substantially cylindrical shape from a magnetic material such as ferritic stainless steel. The movable core 50 is provided on the nozzle hole 26 side of the fixed core 30 so as to be reciprocally movable with respect to the housing 20. A gap 200 as a “first gap” is formed between the outer wall 505 of the movable core 50, the inner wall 211 of the first cylinder member 21, and the inner wall 221 of the second cylinder member 22.

The movable core 50 has an insertion hole 500 through which the shaft portion 41 is inserted. The inner wall of the insertion hole 500 slides with the outer wall 412 of the shaft portion 41.
The fixed core 30 side of the insertion hole 500 faces the flange end surface 431 as the “end surface on the nozzle hole side of the flange” on the nozzle hole 26 side of the flange 43 and the end surface of the fixed core 30 on the nozzle hole 26 side. A movable core abutting surface 501 is provided as an end surface of the movable core opposite to the nozzle hole. The movable core contact surface 501 is provided with a film having excellent wear resistance, for example, a hard chromium plating film. The movable core 50 has a plurality of communication passages 502 that allow the movable core 50 to communicate with the fixed core 30 side and the nozzle hole 26 side. The plurality of communication paths 502 are positioned at equal intervals on the circumference of a virtual circle centered on a point on the central axis CA0.

  The fixed core 30 is welded to the third cylindrical member 23 of the housing 20 so as to be fixed to the inside of the housing 20. The fixed core 30 has a fixed core main body 301 and a fixed core sliding portion 302.

  The fixed core body 301 is made of a magnetic material such as ferritic stainless steel. The fixed core main body 301 is subjected to a magnetic stabilization process and is provided in a magnetic field formed by a coil 35 described later.

  The fixed core sliding portion 302 is a cylindrical member provided inside the end portion on the nozzle hole 26 side of the fixed core main body portion 301. The fixed core sliding portion 302 is subjected to, for example, chromium plating on the surface, and has a hardness similar to the hardness of the gap forming member 60 and the movable core abutting surface 501. As shown in FIG. 2, the fixed core sliding portion 302 has an end face 303 on the injection hole 26 side positioned on the injection hole 26 side of the end face 304 on the injection hole 26 side of the fixed core main body 301. Thereby, when the movable core 50 moves in the valve opening direction, the movable core abutting surface 501 of the movable core 50 and the end surface 303 of the fixed core sliding portion 302 abut, and the movement of the movable core 50 in the valve opening direction is performed. Be regulated.

The gap forming member 60 is an annular member provided on the radially outer side of the flange portion 43. The end surface 600 on the nozzle hole 26 side of the gap forming member 60 is in contact with the movable core contact surface 501. Further, one end of the first spring 31 is in contact with the end surface 609 of the gap forming member 60 opposite to the nozzle hole 26.
The outer wall 601 of the gap forming member 60 slides on the inner wall 305 of the fixed core sliding portion 302. The inner wall 602 of the gap forming member 60 slides on the outer wall 434 on the radially outer side of the flange portion 43. The inner edge 603 of the gap forming member 60 on the nozzle hole 26 side is formed so that the inner diameter decreases from the nozzle hole 26 side toward the opposite side of the nozzle hole 26. Further, the outer edge portion 604 of the gap forming member 60 on the nozzle hole 26 side is formed so that the outer diameter increases from the nozzle hole 26 side toward the opposite side of the nozzle hole 26. Further, the inner edge portion 605 of the gap forming member 60 opposite to the injection hole 26 is formed so that the inner diameter increases from the injection hole 26 side toward the opposite side of the injection hole 26. Further, the outer edge portion 606 of the gap forming member 60 opposite to the nozzle hole 26 is formed so that the outer diameter decreases from the nozzle hole 26 side toward the opposite side of the nozzle hole 26.

  The gap forming member 60 has a communication path 607 as a “first flow path” at the radially outer end. The communication path 607 communicates the opposite side of the gap forming member 60 from the nozzle hole 26 and the nozzle hole 26 side. Further, the gap forming member 60 has a communication path 608 as a “second flow path” at the end on the nozzle hole 26 side. The communication path 608 communicates the inner side and the outer side of the gap forming member 60.

  The length of the gap forming member 60 in the direction of the central axis CA0 is longer than the length of the flange portion 43 in the direction of the central axis CA0. As a result, in the fuel injection valve 1, when the seal portion 42 and the valve seat 250 are in contact with each other and the first spring 31 described later urges the needle 40 and the gap forming member 60 in the valve closing direction, A gap 430 as a “second gap” is formed between the part end surface 431 and the movable core contact surface 501.

  The coil 35 is formed in a cylindrical shape and is provided so as to mainly surround the radially outer sides of the second cylinder member 22 and the third cylinder member 23. The coil 35 forms a magnetic field around it when power is supplied. When the magnetic field is formed, a magnetic circuit is formed inside the fixed core 30, the movable core 50, the first cylinder member 21, the third cylinder member 23, and the holder 17.

  The first spring 31 is provided such that one end of the first spring 31 can abut on the end of the gap forming member 60 opposite to the movable core 50 and the end of the flange 43 opposite to the movable core 50. The other end of the first spring 31 is in contact with the end surface 111 on the injection hole 26 side of the adjusting pipe 11 that is press-fitted and fixed inside the fixed core 30. The first spring 31 is provided so as to be able to bias the needle 40 in the valve closing direction while biasing the gap forming member 60 in the valve seat 250 direction, that is, in the valve closing direction.

  The second spring 32 is provided so that one end thereof is in contact with the inner wall of the first cylindrical member 21. The other end of the second spring 32 is in contact with the end surface 503 of the movable core 50 on the nozzle hole 26 side. The second spring 32 urges the movable core 50 in the direction opposite to the valve seat 250, that is, in the valve opening direction.

  In the present embodiment, the urging force of the second spring 32 is set to be smaller than the urging force of the first spring 31. Thereby, when electric power is not supplied to the coil 35, the seal portion 42 of the needle 40 is in contact with the valve seat 250, that is, in a closed state.

  A cylindrical fuel introduction pipe 12 is press-fitted and welded to the end of the third cylinder member 23 opposite to the second cylinder member 22 side. A filter 13 is provided inside the fuel introduction pipe 12. The filter 13 collects foreign matters contained in the fuel that has flowed from the introduction port 14 of the fuel introduction pipe 12.

  The radially outer sides of the fuel introduction pipe 12 and the third cylinder member 23 are molded with resin. The molded part has a connector 15. The connector 15 is insert-molded with a terminal 16 for supplying power to the coil 35. A cylindrical holder 17 is provided outside the coil 35 in the radial direction so as to cover the coil 35.

  The fuel that flows into the inside of the housing 20 from the introduction port 14 of the fuel introduction pipe 12 flows between the inside of the fixed core 30, the inside of the adjusting pipe 11, the flow path 400, the hole 411, the first cylindrical member 21 and the shaft portion 41. It flows between them and is guided inside the injection nozzle 25. Further, a part of the fuel flowing inside the adjusting pipe 11 flows between the communication path 607, between the movable core 50 and the fixed core 30, between the communication path 502, the first cylindrical member 21 and the shaft portion 41, It is guided inside the injection nozzle 25.

Next, the manufacturing method of the fuel injection valve 1 will be described, in particular, the steps related to the gap forming member 60.
The gap forming member 60 is assembled to the needle 40 inserted into the insertion hole 500 of the movable core 50 provided inside the housing 20. Specifically, the gap forming member 60 is inserted into the inside of the housing 20 from the opening on the side where the fuel introduction pipe 12 of the third cylinder member 23 is provided, and has a fixed core 30 that is fixed to the inside of the housing 20 first. The gap forming member 60 is assembled so as to slide on the outer wall 434 of the flange 43 while sliding on the inner wall 305 of the fixed core sliding portion 302.
Thereafter, the first spring 31 and the adjusting pipe 11 are inserted into the housing 20 from the opening of the third cylinder member 23 on the side where the fuel introduction pipe 12 is provided. One end of the first spring 31 is brought into contact with the end surface of the needle 40 and the gap forming member 60 opposite to the nozzle hole 26. After the other end of the first spring 31 is brought into contact with the end surface 111 of the adjusting pipe 11, the position of the adjusting pipe 11 with respect to the fixed core 30 is adjusted.

Next, the effect | action of the fuel injection valve 1 is demonstrated based on FIGS.
When power is not supplied to the coil 35, the seal portion 42 of the needle 40 is in contact with the valve seat 250. At this time, the needle 40, the movable core 50, and the gap forming member 60 are in the positional relationship shown in FIG. Specifically, since no magnetic attractive force is generated between the fixed core 30 and the movable core 50, a gap is formed between the fixed core 30 and the movable core 50. At this time, the first spring 31 contacts not only the gap forming member 60 but also the needle 40 and urges the needle 40 in the valve closing direction, so that a gap 430 is formed. The gap 430 is filled with fuel flowing through the fuel passage 18.

  When electric power is supplied to the coil 35 and a magnetic attractive force is generated between the fixed core 30 and the movable core 50, the movable core 50 opens while accelerating a distance corresponding to the length of the gap 430 in the direction of the central axis CA0. The movable core contact surface 501 collides with the flange end surface 431 (see FIG. 3). At this time, the fuel in the gap 430 flows out quickly between the fixed core 30 and the movable core 50 through the communication path 608. Further, the first spring 31 is in contact with only the gap forming member 60.

  Further, the movable core 50 moves in the valve opening direction while the movable core contact surface 501 and the flange end surface 431 are in contact with each other by the magnetic attractive force between the fixed core 30 and the movable core 50. As a result, the seal portion 42 is separated from the valve seat 250 and the nozzle hole 26 is opened. When the injection hole 26 is opened, the fuel guided to the inside of the injection nozzle 25 is injected outside through the injection hole 26. When the movable core 50 moving in the valve opening direction comes into contact with the fixed core sliding portion 302 as shown in FIG. 4, the movement of the movable core 50 in the valve opening direction stops.

  When the supply of power to the coil 35 is stopped, the magnetic attractive force generated between the fixed core 30 and the movable core 50 disappears, so that the gap forming member 60 and the movable core 50 are attached to the first spring 31. The valve moves in the valve closing direction due to the difference between the urging force and the urging force of the second spring 32. At this time, the needle 40 moves in the valve closing direction while maintaining the relative positional relationship between the movable core 50 and the gap forming member 60 shown in FIG. 4 by the pressure of the fuel acting in the valve closing direction.

  When the needle 40 further moves in the valve closing direction and the seal portion 42 and the valve seat 250 come into contact with each other, the movement of the needle 40 in the valve closing direction stops and the nozzle hole 26 is closed. The gap forming member 60 and the movable core 50 move in the valve closing direction even after the seal portion 42 and the valve seat 250 abut, and return to the state shown in FIG. 2 by the urging force of the first spring 31.

  The fuel injection valve 1 according to the first embodiment has a flange portion when the seal portion 42 abuts the valve seat 250 and the first spring 31 urges the needle 40 and the gap forming member 60 in the valve closing direction. A gap 430 is provided between the end surface 431 and the movable core contact surface 501. In the fuel injection valve 1, the movable core 50 collides with the needle 40 after accelerating a distance corresponding to the length of the gap 430 in the direction of the central axis CA 0 when electric power is supplied to the coil 35. Thereby, in the fuel injection valve 1, a relatively large valve opening force can be applied to the needle 40.

  Further, the reciprocating movement of the end portion of the needle 40 on the side having the flange portion 43 is guided to the fixed core 30 through the gap forming member 60. The movable core 50 slides on the outer wall 412 of the needle 40 inserted through the insertion hole 500, and the reciprocating movement of the movable core 50 is guided by the needle 40. Thereby, the reciprocating movement of the movable core 50 is guided so that there is a gap 200 between the outer wall 505 of the movable core 50 and the inner wall 211 of the first cylindrical member 21 and the inner wall 221 of the second cylindrical member 22. Therefore, it is not necessary to slide the movable core 50 on the inner wall of the housing 20, and the frictional resistance acting on the movable core 50 can be reduced as compared with the case where the outer wall of the movable core and the inner wall of the housing slide. it can. Therefore, it is possible to prevent the moving speed of the movable core 50 in the valve opening direction from being slowed by friction with the housing 20, and to increase the valve opening force of the movable core 50 acting on the needle 40.

  Further, since the frictional resistance is reduced in the movable core 50, the wear of the movable core 50 can be reduced. This prevents changes in the suction characteristics of the movable core 50 and the fixed core 30 that are deformed due to wear of the movable core 50, and wear powder generated by wear of the movable core 50 is between the needle 40 and the valve seat 250. It is possible to prevent biting.

In the fuel injection valve described in Patent Document 1, the reciprocating movement of the needle is such that the middle portion of the needle located on the nozzle hole side and the nozzle hole side end slide relative to the housing from the end opposite to the nozzle hole. Be guided by doing. The end of the needle opposite to the nozzle hole is guided through a movable core. The movable core may be worn because the outer wall slides with the inner wall of the housing. When the movable core is worn, the reciprocating movement of the end opposite to the nozzle hole of the needle becomes unstable, and there is a possibility that desired fuel injection cannot be performed.
In the fuel injection valve 1 according to the first embodiment, the slidable contact portion 44 located at the end portion on the injection hole 26 side of the needle 40 slides on the first cylindrical member 21. Further, the reciprocating movement of the end portion on the side where the flange portion 43 is provided is guided to the fixed core 30 via the gap forming member 60. Therefore, the two end portions of the needle 40 are guided by the housing 20 or the fixed core 30 so that the reciprocation of the needle 40 can be stabilized.

  The gap forming member 60 is formed such that the outer diameter of the outer edge portion 604 on the injection hole 26 side increases from the injection hole 26 side toward the opposite side of the injection hole 26. Thereby, when manufacturing the fuel injection valve 1, the gap forming member 60 can be easily slid on the inner wall 305 of the fixed core sliding portion 302.

  The gap forming member 60 is formed such that the inner diameter of the inner edge 603 on the injection hole 26 side decreases from the injection hole 26 side toward the opposite side of the injection hole 26. The flange 43 is formed such that the outer diameter thereof decreases as the outer edge portion 433 opposite to the injection hole 26 moves from the injection hole 26 side to the opposite side of the injection hole 26. Thereby, when manufacturing the fuel injection valve 1, the clearance gap formation member 60 can be easily slid to the collar part 43. FIG.

  Further, the gap forming member 60 has an inner edge portion 603 and an outer edge portion 604 on the injection hole 26 side, and an inner edge portion 605 and an outer edge portion 606 on the opposite side to the injection hole 26 from the injection hole 26 side to the injection hole 26 side. The inner diameter or the outer diameter is formed to change toward the side. Thus, when the gap forming member 60 is placed inside the housing 20, the gap forming member 60 can be easily inserted into the inner wall 305 of the fixed core sliding portion 302 and the outer wall of the flange portion 43 without checking the direction of the gap forming member 60. 434 can be slid. Therefore, the manufacturing man-hour of the fuel injection valve 1 can be reduced.

  Further, when the fuel injection valve 1 is manufactured, the gap forming member 60 has the needle 40 so that the inner wall 602 slides on the outer wall 434 of the flange portion 43 after the outer wall 601 slides on the inner wall 305 of the fixed core sliding portion 302. Assembled into. Thereby, even if the needle 40 before assembling the gap forming member 60 is tilted with respect to the central axis CA0, the two sliding portions of the gap forming member 60 slide in order. Can be easily assembled.

  The communication path 607 included in the gap forming member 60 communicates the side opposite to the nozzle hole 26 of the gap forming member 60 and the nozzle hole 26 side of the gap forming member 60. As a result, the fuel on the inlet 14 side and the fuel between the fixed core 30 and the movable core 50 come and go reliably, and the viscous resistance due to the fuel when the gap forming member 60 moves in the direction of the central axis CA0. Can be reduced. Therefore, responsiveness in opening and closing the nozzle hole 26 can be improved as compared with the case where the communication path is not provided.

  The communication path 608 included in the gap forming member 60 is formed to be able to communicate with the gap 430. When the volume of the gap 430 changes due to the movement of the needle 40 with respect to the gap forming member 60, the fuel flows out of the gap 430 to the outside of the gap forming member 60 or flows into the gap 430 from the outside of the gap forming member 60 via the communication path 608. To do. Thereby, the viscous resistance by the fuel when the needle 40 moves in the direction of the central axis CA0 can be reduced. Therefore, the moving speed of the movable core 50 in the valve opening direction is prevented from being slowed by the viscous resistance of the fuel as compared with the case without the communication path, and the valve opening force of the movable core 50 acting on the needle 40 is further increased. Can be bigger.

(Second embodiment)
Next, the fuel injection valve by 2nd embodiment of this invention is demonstrated based on FIG. The second embodiment is different from the first embodiment in that an urging force transmission member is provided. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 1st embodiment, and description is abbreviate | omitted. FIG. 5 illustrates a valve opening direction in which the needle 40 is separated from the valve seat 250 and a valve closing direction in which the needle 40 is in contact with the valve seat 250.

  FIG. 5 shows a cross-sectional view of the main part of the fuel injection valve 2 according to the second embodiment. The fuel injection valve 2 includes an urging force transmission member 65 and the like.

  The biasing force transmission member 65 is a substantially annular member provided between the first spring 31 and the gap forming member 60. A gap is formed between the inner wall 651 of the urging force transmission member 65 and the outer wall 451 of the protrusion 45 described later. Further, the outer wall 652 of the urging force transmission member 65 forms a gap with the inner wall 305 of the fixed core sliding portion 302. The urging force transmission member 65 is provided so as to be in contact with the end surface 432 of the flange portion 43 opposite to the nozzle hole 26 while abutting the end surface 609 of the gap forming member 60. The biasing force transmission member 65 is configured such that the end surface 609 of the gap forming member 60 is in contact with the seal portion 42 and the valve seat 250 and when the first spring 31 biases the needle 40 and the gap forming member 60 in the valve closing direction. And the end face 432 on the opposite side to the nozzle hole 26 of the collar part 43 contacts.

The needle 40 includes a shaft portion 41, a seal portion 42, a sliding contact portion 44, a flange portion 43, a protruding portion 45, and the like. The shaft portion 41, the seal portion 42, the sliding contact portion 44, the flange portion 43, and the protruding portion 45 are integrally formed.
The protruding portion 45 is provided so as to protrude in the direction opposite to the nozzle hole 26 from the end portion of the shaft portion 41 opposite to the nozzle hole 26. The protrusion 45 has a communication path 450 that communicates with the flow path 400. The outer edge 452 of the protrusion 45 opposite to the injection hole 26 is formed so that the outer diameter decreases from the injection hole 26 side toward the opposite side of the injection hole 26.

In the fuel injection valve 2 according to the second embodiment, when the seal portion 42 and the valve seat 250 are in contact with each other and the first spring 31 urges the needle 40 and the gap forming member 60 in the valve closing direction, the end surface of the collar portion A gap 430 is provided between 431 and the movable core contact surface 501. As a result, a relatively large valve opening force can be applied to the needle 40.
Further, the end portion of the needle 40 on the side having the flange portion 43 is guided to the fixed core 30 via the gap forming member 60. The movable core 50 is guided by the needle 40. Thereby, it can prevent that the moving speed to the valve opening direction of the movable core 50 becomes slow by friction with the housing 20. FIG. Therefore, 2nd embodiment has an effect of 1st embodiment.

  In the fuel injection valve 2, the urging force transmission member 65 with which the first spring 31 abuts is provided so as to urge the needle 40 in the valve closing direction while urging the gap forming member 60 in the valve opening direction. ing. Thereby, the urging force of the first spring 31 can be stably transmitted to the gap forming member 60 and the needle 40, and the injection hole 26 in the fuel injection valve 2 can be stably opened and closed.

(Third embodiment)
Next, the fuel injection valve by 3rd embodiment of this invention is demonstrated based on FIG. The third embodiment differs from the second embodiment in the shape of the urging force transmission member. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 2nd embodiment, and description is abbreviate | omitted. FIG. 6 illustrates a valve opening direction in which the needle 40 is separated from the valve seat 250 and a valve closing direction in which the needle 40 is in contact with the valve seat 250.

  FIG. 6 shows a cross-sectional view of the main part of the fuel injection valve 3 according to the third embodiment. The fuel injection valve 3 includes an urging force transmission member 75 and the like.

  The urging force transmission member 75 is a member provided between the first spring 31 and the gap forming member 60. The urging force transmission member 75 is formed of an annular portion 751 and a cylindrical portion 752 as an “inner sliding portion”.

  The annular portion 751 is located between the first spring 31 and the gap forming member 60. The annular portion 751 is provided so as to be in contact with the end surface 432 opposite to the nozzle hole 26 of the flange portion 43 while being in contact with the end surface 609 of the gap forming member 60. When the seal portion 42 and the valve seat 250 are in contact with each other and the first spring 31 urges the needle 40 and the gap forming member 60 in the valve closing direction, the annular portion 751 has the end surface 609 of the gap forming member 60 and The flange portion 43 is in contact with the end surface 432 opposite to the nozzle hole 26.

  The cylindrical portion 752 is a cylindrical portion that is provided so as to extend from the radially inner end of the annular portion 751 in the valve opening direction. The inner wall 753 of the cylindrical portion 752 is provided to slide on the outer wall 451 of the protruding portion 45.

In the fuel injection valve 3 according to the third embodiment, when the seal portion 42 and the valve seat 250 are in contact with each other and the first spring 31 urges the needle 40 and the gap forming member 60 in the valve closing direction, the flange end surface A gap 430 is provided between 431 and the movable core contact surface 501. As a result, a relatively large valve opening force can be applied to the needle 40.
Further, the end portion of the needle 40 on the side having the flange portion 43 is guided to the fixed core 30 via the gap forming member 60. The movable core 50 is guided by the needle 40. Thereby, it can prevent that the moving speed to the valve opening direction of the movable core 50 becomes slow by friction with the housing 20. FIG.
Further, the urging force transmission member 75 can stably transmit the urging force of the first spring 31 to the gap forming member 60 and the needle 40. Therefore, the third embodiment has the effects of the second embodiment.

  Further, in the fuel injection valve 3, the cylindrical portion 752 slides on the protruding portion 45. Thereby, the position of the urging force transmission member 75 is stabilized, and the urging force of the first spring 31 can be stably transmitted to the gap forming member 60 and the needle 40. Therefore, the nozzle hole 26 in the fuel injection valve 3 can be opened and closed more stably.

(Fourth embodiment)
Next, the fuel injection valve by 4th embodiment of this invention is demonstrated based on FIG. The fourth embodiment differs from the second embodiment in the shapes of the needle and the urging force transmission member. In addition, the same code | symbol is attached | subjected to the site | part substantially the same as 2nd embodiment, and description is abbreviate | omitted. FIG. 7 illustrates a valve opening direction in which the needle 40 is separated from the valve seat 250 and a valve closing direction in which the needle 40 is in contact with the valve seat 250.

  FIG. 7 shows a cross-sectional view of the main part of the fuel injection valve 4 according to the fourth embodiment. The fuel injection valve 4 includes an urging force transmission member 85 and the like.

  The urging force transmission member 85 is a member provided between the first spring 31 and the gap forming member 60. The urging force transmitting member 85 is formed of an annular portion 851 and a cylindrical portion 852 as an “outer sliding portion”.

  The annular portion 851 is located between the first spring 31 and the gap forming member 60. The annular portion 851 is provided so as to be in contact with the end surface 432 of the flange portion 43 opposite to the nozzle hole 26 while being in contact with the end surface 609 of the gap forming member 60. When the seal portion 42 and the valve seat 250 are in contact with each other and the first spring 31 urges the needle 40 and the gap forming member 60 in the valve closing direction, the annular portion 851 has the end face 609 of the gap forming member 60 and The flange portion 43 is in contact with the end surface 432 opposite to the nozzle hole 26.

  The cylindrical portion 852 is a cylindrical portion provided so as to extend in the valve closing direction from the radially outer end of the annular portion 851. The outer wall 853 of the cylindrical portion 852 is provided to slide on the inner wall 305 of the fixed core sliding portion 302.

The needle 40 is formed of a shaft portion 41, a seal portion 42, a sliding contact portion 44, a flange portion 43, a protruding portion 45, a spring seat portion 46, and the like.
The spring seat portion 46 is a substantially annular portion provided between the sliding contact portion 44 and the flange portion 43 and on the radially outer side of the shaft portion 41. The spring seat portion 46 is fixed to the shaft portion 41 so as to be able to reciprocate integrally with the shaft portion 41. The spring seat portion 46 supports one end of the second spring 33 as a “second biasing member”. The other end of the second spring 33 is in contact with the end surface 503 of the movable core 50. The second spring 33 urges the movable core 50 that does not have the communication passage 502 in the direction opposite to the valve seat 250 as compared with the second embodiment.
In the present embodiment, the urging force of the second spring 33 is set to be smaller than the urging force of the first spring 31. Thereby, when electric power is not supplied to the coil 35, the seal portion 42 of the needle 40 is in contact with the valve seat 250, that is, in a closed state.

In the fuel injection valve 4 according to the fourth embodiment, when the seal portion 42 and the valve seat 250 are in contact with each other and the first spring 31 urges the needle 40 and the gap forming member 60 in the valve closing direction, the end surface of the collar portion A gap 430 is provided between 431 and the movable core contact surface 501. As a result, a relatively large valve opening force can be applied to the needle 40.
Further, the end portion of the needle 40 on the side having the flange portion 43 is guided to the fixed core 30 via the gap forming member 60. The movable core 50 is guided by the needle 40. Thereby, it can prevent that the moving speed to the valve opening direction of the movable core 50 becomes slow by friction with the housing 20. FIG.
Further, the urging force transmission member 85 can stably transmit the urging force of the first spring 31 to the gap forming member 60 and the needle 40. Therefore, the fourth embodiment has the effects of the second embodiment.

  Further, in the fuel injection valve 4, the cylindrical portion 852 slides on the fixed core sliding portion 302. Thereby, the position of the urging force transmission member 85 is stabilized, and the urging force of the first spring 31 can be stably transmitted to the gap forming member 60 and the needle 40. Therefore, the nozzle hole 26 in the fuel injection valve 4 can be opened and closed more stably.

(Other embodiments)
(A) In the above-described embodiment, the inner edge portion and the outer edge portion on the injection hole side of the gap forming portion, and the inner edge portion and the outer edge portion on the opposite side to the injection hole are on the opposite side of the injection hole from the injection hole side. The inner diameter or the outer diameter changes as it goes, so-called a tapered shape. However, at least one of these may be formed in a taper shape, or not all of them may be formed in a taper shape.

  (A) In the above-described embodiment, the gap forming member has the “first flow path” and the “second flow path”. However, the gap forming member may not have these flow paths.

  (C) In the above-described embodiment, the shaft portion and the flange portion are formed integrally. However, it may be a separate member.

  (D) In the first to third embodiments, the movable core has the communication path. However, it is not necessary to have a communication path as in the fourth embodiment.

  (E) In the first to third embodiments, the second spring is provided so that one end on the injection hole side is in contact with the inner wall of the first cylindrical member. However, like 4th embodiment, you may make it contact | abut to the control part provided between the sliding contact part and the collar part and the radial direction outer side of the axial part.

  As mentioned above, this invention is not limited to such embodiment, It can implement with a various form in the range which does not deviate from the summary.

1, 2, 3, 4 ... fuel injection valve,
20 ・ ・ ・ Housing,
200 ・ ・ ・ Gap (first gap),
26 ... nozzle hole,
30 ... fixed core,
35 ... Coil,
41 ... Shaft part (needle part),
42 ... Seal part (end part which can contact the valve seat of the needle part),
43 ... buttocks,
430 ... gap (second gap),
431... Collar part end face (end face on the nozzle hole side of the collar part),
44 ・ ・ ・ Sliding contact part (needle part),
50 ... movable core,
500 ... insertion hole,
501... Movable core contact surface (end surface opposite to the nozzle hole of the movable core),
60 ・ ・ ・ Gap forming member,
65, 75, 85 ... urging force transmission member.

Claims (9)

A housing (20) having a nozzle hole (26) into which fuel is injected and a valve seat (250) formed around the nozzle hole;
Needle portions (41, 42, 44) that are accommodated in the housing so as to be reciprocally movable, and that open and close the nozzle hole when separated from the valve seat or abut against the valve seat;
A collar part (43) provided on the radially outer side of the end part opposite to the end part (42) capable of contacting the valve seat of the needle part;
A cylindrical fixed core (30) fixed in the housing;
There is an insertion hole (500) provided on the nozzle hole side of the fixed core, through which the needle portion is inserted, and the outer wall (505) is between the inner wall (211 and 221) of the housing with a first gap ( 200) and a movable core (50) in which the inner wall of the insertion hole is slidable with the outer wall (412) of the needle part,
A coil (35) capable of attracting the movable core toward the fixed core when power is supplied;
An inner wall is provided radially outside the flange so that the inner wall can slide with the outer wall (434) of the flange and the outer wall can slide with the inner wall (305) of the fixed core. A gap forming member (63) capable of forming a second gap (430) therebetween;
A first biasing member (31) capable of biasing the movable core in the valve closing direction via the gap forming member and biasing the needle part in the valve closing direction via the flange;
A second biasing member (32, 33) for biasing the movable core in the valve opening direction with a biasing force smaller than the biasing force of the first biasing member;
With
When the needle portion and the valve seat are in contact with each other, and the first biasing member biases the needle portion and the gap forming member in the valve closing direction, The fuel injection valve, wherein the second gap is formed between an end surface (431) and an end surface (501) opposite to the injection hole of the movable core.   An urging force transmission member (65, 75, 85) provided between the gap forming member and the first urging member and capable of transmitting the urging force of the first urging member to the gap forming member and the flange portion. The fuel injection valve according to claim 1, further comprising:   The fuel injection valve according to claim 2, wherein the biasing force transmission member has an outer sliding portion (852) that slides on an inner wall (305) of the fixed core. A protrusion (45) protruding in the direction opposite to the nozzle hole from the end of the needle part opposite to the nozzle hole;
The fuel injection valve according to claim 2 or 3, wherein the urging force transmission member has an inner sliding portion (752) that slides on an outer wall (451) of the protruding portion.   The gap forming member is formed in a direction perpendicular to the central axis (CA0) of the housing at the inner edge (603) of the end on the nozzle hole side and the outer edge (606) of the end opposite to the nozzle hole. 5. The fuel according to claim 1, wherein a size of the fuel decreases as it goes from the nozzle hole side toward the opposite side of the nozzle hole along the central axis. Injection valve.   The gap forming member is arranged in a direction perpendicular to the central axis (CA0) of the housing at the outer edge (604) at the end on the nozzle hole side and the inner edge (605) at the end opposite to the nozzle hole. The fuel according to any one of claims 1 to 5, wherein a size of the fuel increases from the nozzle hole side toward the opposite side of the nozzle hole along the central axis. Injection valve.   The fuel injection according to any one of claims 1 to 6, wherein the gap forming member has a first flow path (607) that communicates the opposite side to the injection hole and the injection hole side. valve.   The fuel injection valve according to any one of claims 1 to 7, wherein the gap forming member has a second flow path (608) communicating the inner side and the outer side. A spring seat portion (46) provided between an end portion of the needle portion that can contact the valve seat and the flange portion and radially outward of the needle portion and capable of reciprocating integrally with the needle portion. )
9. The fuel injection according to claim 1, wherein one end of the second urging member is in contact with the movable core and the other end is in contact with the spring seat portion. valve.

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