JP2013104340A - Electromagnetic fuel injection valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic fuel injection valve configured to maintain stable valve open/closed state for a long time, to mitigate the impact when the valve is opened/closed, and to reduce wear or noise of a collision part.SOLUTION: A guide bush 19 of high hardness is fixed to an inner circumference of a fixed core 6. A sliding member 20 to be slidably fitted on an inner circumferential surface of the guide bush 19 and a stopper member 22 arranged forward thereof are fixed to a stem 15b of a valve body 15. A movable core 16 is slidably fitted to the stem 15b so as to move in a limited stroke between the sliding member 20 and the stopper member 22. When a coil 37 is electrically energized, the movable core 16 to be attracted by the fixed core 6 opens the valve body 15 via the sliding member 20. When the coil 37 is not electrically energized, the valve body 15 is closed by a biasing force of a valve spring 33. The movable core 16 abuts on the stopper member 22.

Description

  The present invention includes a valve housing having a valve seat at one end, a hollow fixed core connected to the other end of the valve housing, a movable core opposed to the suction surface of the fixed core, and an outer periphery of the fixed core. A coil that is disposed; a valve body that cooperates with the valve seat; and a valve spring that biases the valve body in a valve closing direction, and the stationary core attracts the movable core by energization of the coil. The present invention relates to an improvement in an electromagnetic fuel injection valve in which the valve body is opened.

  Such an electromagnetic fuel injection valve is already known as disclosed in Patent Document 1.

JP 2008-31853 A

  Conventionally, in such an electromagnetic fuel injection valve, in order to stabilize the opening / closing posture of the valve body, the stem of the valve body is slidably supported on the inner peripheral surface of the fixed core. ~ Known as disclosed in FIG. However, since the fixed core made of a magnetic material has a relatively low hardness, the use of the inner peripheral surface as a guide part of the stem of the high hardness valve body speeds up wear of the guide part, It becomes difficult to maintain a stable opening / closing posture for a long time. In the conventional electromagnetic fuel injection valve, the movable core is integrally coupled to the valve body. Therefore, when the valve body is opened and closed, the valve body and the movable core are integrated to exert a large impact on the fixed core and the valve seat. This causes wear and noise at the collision part, and rebound of the valve body from the valve seat.

  The present invention has been made in view of such circumstances, and can maintain a stable opening and closing posture of the valve body over a long period of time, and also reduces the impact when the valve body is opened and closed, and wear and noise of the collision part. It is another object of the present invention to provide the electromagnetic fuel injection valve that can reduce the rebound of the valve body from the valve seat.

  To achieve the above object, the present invention provides a valve housing having a valve seat at one end, a hollow fixed core connected to the other end of the valve housing, and a movable core opposed to the suction surface of the fixed core. And a coil disposed on the outer periphery of the fixed core, a valve body that cooperates with the valve seat, and a valve spring that urges the valve body in a valve closing direction, and the fixing is performed by energizing the coil. In an electromagnetic fuel injection valve in which the valve element is opened by the core sucking the movable core, a guide bush having a hardness higher than that of the fixed core is fixed to the inner periphery of the fixed core. A valve portion cooperating with the valve seat, and a stem connected to the valve portion and extending toward the guide bush. The stem is slidably fitted to the inner peripheral surface of the guide bush. Between the fixed sliding member and the fixed core and the valve part. The movable core is slidably fitted to the stem so that it can move a limited stroke between the sliding member and the stopper member, and the coil is energized. The movable core sucked by the fixed core opens the valve body through the sliding member, and when the coil is not energized, the valve body is closed by the urging force of the valve spring, A first feature is that the movable core is in contact with the stopper member. The guide bush corresponds to a second guide bush 19 in an embodiment of the present invention described later.

  According to the present invention, in addition to the first feature, the guide bush is made of a non-magnetic or weak magnetic material, and its front end protrudes from the attracting surface of the fixed core. The second feature is that the valve opening limit of the valve body is regulated by bringing the movable core into contact with the front end of the valve body.

  Furthermore, in addition to the first or second feature, the present invention further includes the valve spring for urging the valve body in the valve closing direction via the sliding member in the fixed core. A third feature is that an auxiliary spring for biasing the sliding member and the movable core in a direction away from each other with a set load smaller than that of the valve spring is interposed between the sliding member and the movable core.

  Furthermore, in addition to the third feature, the present invention provides a flange portion that slidably fits the sliding member to the inner peripheral surface of the guide bush, and a shaft portion that protrudes from the front end surface of the flange portion. A fourth feature is that the auxiliary spring is interposed between the front end surface of the flange portion and the movable core, and the shaft portion is disposed in the auxiliary spring.

  According to the first feature of the present invention, the guide bush fixed to the inner periphery of the fixed core is harder than the fixed core, and thus has high wear resistance, and is fixed to the stem of the valve body. Since the sliding member is slidably supported, the opening / closing posture of the valve body can be stabilized over a long period of time, and the fuel injection flow rate characteristic of the fuel injection valve can be stabilized.

  Moreover, during the valve opening process, the impact force that the movable core exerts on the fixed core is the impact force when only the movable core collides with the fixed core and the impact force when the stopper member collides with the movable core. Therefore, each collision energy is relatively small, so that wear of the contact portion between the fixed core and the movable core can be prevented, and the collision noise can be suppressed to a small level. In addition, when the stopper member collides with the movable core, the valve spring is deformed more than the amount of compressive deformation at the time of normal opening, so the valve spring absorbs the collision energy of the stopper member against the movable core and reduces the impact force. It will be.

  Also, in the valve opening process, only the movable core slides on the stem of the valve body and is pulled toward the fixed core. After acceleration, the sliding member is pushed up against the set load of the valve spring. Therefore, the valve body can be opened quickly, and the valve opening response of the valve body can be improved.

  On the other hand, in the valve closing process, the impact force applied to the valve seat by the valve body is the impact force when only the valve body is first seated on the valve seat, and then when the movable core collides with the stopper member. Since it is divided into impact force, each collision energy becomes relatively small, so that wear of the valve portion and the contact portion between the valve seats can be prevented, and the seating noise can be kept small.

  The valve body bounces backward due to its seating impact at the time of first seating on the valve seat, but the front end surface of the movable core abuts against a stopper member fixed to the rising valve body, so that the amount of bounce is minimized. To the limit.

  According to the second feature of the present invention, when the coil is energized, the front end of the non-magnetic or weak-magnetic guide bush protruding from the attracting surface of the fixed core receives the movable core to regulate the valve opening limit of the valve body, An air gap is formed between the fixed core and the movable core. Thereby, at the time of energization interruption of a coil, disappearance of residual magnetism between a fixed core and a movable core can be accelerated, and the valve closing response of a valve element can be improved.

  According to the third feature of the present invention, when the valve body is closed, the movable core is pressed and held at the contact position with the stopper member by the set load of the auxiliary spring, and vibration of the movable core can be prevented. In addition, since the set load of the auxiliary spring is set smaller than the set load of the valve spring that urges the valve body in the valve closing direction, the auxiliary spring is configured to attract and move the fixed core to the movable core when the coil is energized. The sliding member does not interfere with the contact of the sliding member with the movable core and does not hinder the opening of the valve body to a predetermined position.

  According to the fourth aspect of the present invention, the shaft portion of the sliding member is fitted to the inner peripheral surface of the auxiliary spring and plays a role of positioning, and the interval between the valve spring and the auxiliary spring is reduced. The axial dimension of the electromagnetic fuel injection valve can be shortened and, consequently, downsized.

The longitudinal side view of the electromagnetic fuel injection valve for engines which concerns on embodiment of this invention. FIG. 2 is an enlarged view of part 2 of FIG. 1. FIG. 3 is a sectional view taken along line 3-3 in FIG. 2. Action | operation explanatory drawing of the same electromagnetic fuel injection valve.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 and 2, the cylinder head 1 of the engine is provided with a mounting hole 1b that opens into the combustion chamber 1a, and an electromagnetic fuel injection valve I is mounted in the mounting hole 1b. The fuel injection valve I can inject fuel toward the combustion chamber 1a.

  The valve housing 2 of the fuel injection valve I includes a valve seat member 3, a magnetic cylinder 4 coaxially coupled to the rear end of the valve seat member 3, and a coaxial coupling to the rear end of the magnetic cylinder 4. The nonmagnetic cylindrical body 5 is made up of. A fixed core 6 is coaxially coupled to the rear end of the nonmagnetic cylindrical body 5, and a fuel inlet cylinder 7 is coaxially connected to the rear end of the fixed core 6. The fixed core 6 has a hollow portion 6 b communicating with the inside of the fuel inlet cylinder 7. A fuel filter 14 is attached to the inlet of the fuel inlet cylinder 7.

  The valve seat member 3 includes a small-diameter cylindrical portion 3a having a front end wall and a large-diameter cylindrical portion 3b formed at the rear end of the small-diameter cylindrical portion 3a. A valve seat 8, a valve hole 9 connected to the front end of the valve seat 8, and a fuel injection hole 10 connected to the valve hole 9 and opened at the front end surface of the small diameter cylindrical portion 3a are formed.

  The magnetic cylindrical body 4 includes a thin cylindrical portion 4a and a thick cylindrical portion 4b connected to the rear end of the thin cylindrical portion 4a. The thick cylindrical portion 4b has an inner diameter of the thin cylindrical portion 4a. The outer diameter is smaller than that of the thin cylindrical portion 4a. The shim 11 and the large diameter cylindrical portion 3b of the valve seat member 3 are sequentially fitted to the inner peripheral surface of the thin cylindrical portion 4a, and the large diameter cylindrical portion 3b is liquid-tightly welded to the thin cylindrical portion 4a.

  The thick cylindrical portion 4b has an annular protrusion 12 protruding from the rear end surface on the inner peripheral side, and the nonmagnetic cylindrical body 5 is abutted against the tip of the annular protrusion 12 and is liquid-tightly welded. The thick cylindrical portion 4b and the nonmagnetic cylindrical body 5 are formed so that their inner peripheral surfaces are continuous with each other.

  The fixed core 6 has an annular recess 13 on the outer periphery of the front end, and the rear end of the nonmagnetic cylindrical body 5 is fitted into the annular recess 13 and is welded in a liquid-tight manner. The fixed core 6 and the nonmagnetic cylindrical body 5 are formed so that their outer peripheral surfaces are continuous.

  A cylindrical first guide bush 18 is fixed to the inner peripheral surface of the front end portion of the small diameter cylindrical portion 3a by press-fitting to the inner peripheral surface of the front end portion of the small diameter cylindrical portion 3a. A fitting recess 28 that opens to the suction surface 6a at the front end is formed on the inner peripheral surface of the fixed core 6, and a cylindrical second guide bush 19 is fixed to the fitting recess 28 by press fitting. The inner peripheral surface of the second guide bush 19 is continuous with the inner peripheral surface of the fixed core 6.

  A valve body 15 and a movable core 16 are accommodated in the valve housing 2 extending from the valve seat member 3 to the nonmagnetic cylindrical body 5. The valve body 15 includes a valve portion 15 a that opens and closes the valve hole 9 in cooperation with the valve seat 8, and a stem 15 b that is integrally coupled to the valve portion 15 a and extends into the second guide bush 19. The valve portion 15a is formed in a spherical shape so as to always come into line contact with the inner peripheral surface of the first guide bush 18, and the stem 15b is formed in a smaller diameter than the valve portion 15a. A cylindrical fuel flow path 21 is defined between the first guide bush 18 and the stem 15b, and a plurality of fuel flow paths between the first guide bush 18 are formed on the outer peripheral surface of the valve portion 15a. A flat portion 25 is formed. Therefore, the first guide bush 18 allows the passage of fuel while guiding the opening / closing operation of the valve body 15.

  The stem 15b is welded with a sliding member 20 slidably fitted to the inner peripheral surface of the second guide bush 19 and a stopper member 22 disposed between the fixed core 6 and the valve portion 15a. The sliding member 20 is disposed so that its lower end surface protrudes from the lower end surface of the second guide bush 19 at the valve closing position of the valve body 15. The movable core 16 facing the suction surface 6a of the fixed core 6 is slidably fitted to the stem 15b so that it can move a limited stroke s between the sliding member 20 and the stopper member 22. The

  By the two-point support of the valve body 15 by the first and second guide bushes 18 and 19, the outer peripheral surface of the movable core 16 and the inner peripheral surfaces of the magnetic cylindrical body 4 and the nonmagnetic cylindrical body 5 are not A cylindrical gap 30 that prevents contact is secured.

  The second guide bush 19 and the sliding member 20 are made of a nonmagnetic or weak magnetic material having a higher hardness than the fixed core 6, for example, martensitic stainless steel. Accordingly, the hardness of the second guide bush 19 and the sliding member 20 are made substantially equal.

  The sliding member 20 includes a flange portion 20a that is slidably fitted to the inner peripheral surface of the second guide bush 19, and a shaft portion 20b that protrudes from the front end surface of the flange portion 20a. On the other hand, a pipe-like retainer 32 is fitted into the hollow portion 6b of the fixed core 6 and fixed by caulking. Between the retainer 32 and the flange portion 20a, the valve body 15 is seated on the valve seat 8, that is, the seating direction. The valve spring 33 that biases in the valve closing direction is contracted. At that time, the set load of the valve spring 33 is adjusted by the insertion depth of the retainer 32 into the fixed core 6. Since the sliding member 20 is harder than the fixed core 6 as described above, the flange portion 20a serving as the spring seat of the valve spring 33 has high wear resistance.

  Further, an auxiliary spring 34 surrounding the shaft portion 20 b is contracted between the front end face of the flange portion 20 a and the movable core 16, and the auxiliary spring 34 has a set load smaller than the set load of the valve spring 33. It acts so that it may space apart between the sliding member 20 and the movable core 16.

  The rear end portion of the stem 15b protrudes from the rear end surface of the flange portion 20a of the sliding member 20 and is fitted to the inner peripheral surface of the movable end portion of the valve spring 33 to serve as a positioning member. The shaft portion 20b of 20 is fitted to the inner peripheral surface of the auxiliary spring 34 and plays a role of positioning, and the axial direction of the electromagnetic fuel injection valve I is reduced by reducing the interval between the valve spring 33 and the auxiliary spring 34. Contributes to shortening of dimensions and eventually miniaturization.

  A plurality of flat portions 26 (see FIG. 3) serving as fuel flow paths are provided on the outer periphery of the flange portion 20a, and a plurality of through holes 24 serving as fuel flow paths are provided in the movable core 16.

  A coil assembly 35 is fitted on the outer peripheral surface from the annular protrusion 12 of the magnetic cylindrical body 4 to the fixed core 6. The coil assembly 35 includes a bobbin 36 fitted to the outer peripheral surface and a coil 37 wound around the bobbin 36, and a front end of a coil housing 38 surrounding the coil assembly 35 is a magnetic cylindrical body 4. An annular yoke 39 is connected to the rear end surface of the fixed core 6 by welding or the like, and is connected to the outer peripheral surface of the fixed core 6 by welding or the like.

  A synthetic resin coating layer 40 is molded on the outer peripheral surface from the rear end portion of the magnetic cylindrical body 4 to the intermediate portion of the fuel inlet cylinder 7. At this time, a coupler 41 that protrudes to one side of the electromagnetic fuel injection valve I and holds the terminal 42 connected to the coil 37 is formed integrally with the coating layer 40.

  Next, the operation of this embodiment will be described with reference to FIGS.

  In the non-energized state of the coil 37, as shown in FIG. 4A, the valve element 15 is pressed forward by the set load of the valve spring 33, and is seated on the valve seat 8 to close the valve hole 9. In other words, the valve is closed, and the movable core 16 is pressed forward by the set load of the auxiliary spring 34 and held in contact with the stopper member 22, and maintains a predetermined gap with the fixed core 6. .

  When the coil 37 is energized, the magnetic flux generated by the coil 37 sequentially travels through the fixed core 6, the coil housing 38, the magnetic cylindrical body 4 and the movable core 16, and by the magnetic force, first the movable core 16 is moved as shown in FIG. It is attracted by the fixed core 6 and abuts against the front end of the sliding member 20 while compressing the auxiliary spring 34. That is, the movable core 16 rises against the set load of the auxiliary spring 34 that is weaker than the valve spring 33 at the time of initial movement. 20 abuts.

  Therefore, when the movable core 16 that has accelerated and abuts against the sliding member 20, as shown in FIG. 4C, the sliding member 20 is quickly pushed up against the set load of the valve spring 33, 2 Collides with the front end of the guide bush 19 and stops. Meanwhile, the sliding member 20 pushed upward is accompanied by the stem 15b integrated therewith, so that the valve portion 15a is separated from the valve seat 8 and is opened. Thus, the valve opening response of the valve body 15 is enhanced.

  When the movable core 16 impacts the front end of the second guide bush 19 while pushing up the sliding member 20, the valve body 15 including the valve portion 15 a and the stem 15 b is changed to that as shown in FIG. Although the overshoot occurs due to inertia, the overshoot stops when the stopper member 22 integrated with the valve body 15 collides with the front end of the movable core 16. In the meantime, the amount of overshoot of the valve body 15 increases the compression deformation of the valve spring 33 while the sliding member 20 is moved rearward from the movable core 16, so that the valve body is also affected by the repulsive force of the valve spring 33. The 15 overshoot is suppressed.

  When the overshoot is stopped, as shown in FIG. 4E, the sliding member 20 abuts against the rear end surface of the movable core 16 in contact with the second guide bush 19 by the repulsive force of the valve spring 33. By returning to the contact position, the valve body 15 is held at a predetermined valve opening position. At this time, since the set load of the auxiliary spring 34 is set smaller than the set load of the valve spring 33 that urges the valve body 15 in the valve closing direction, the auxiliary spring 34 is fixed to the fixed core when the coil 37 is energized. 6 does not interfere with the suction of the movable core 16 and the contact of the sliding member 20 with the movable core 16 by the valve spring 33, and does not hinder the opening of the valve body 15 to a predetermined position.

  Thus, in the valve opening process of the valve body 15, the impact force that the movable core 16 exerts on the second guide bush 19 includes the impact force when only the movable core 16 first collides with the second guide bush 19, and thereafter Thus, the impact force when the stopper member 22 collides with the movable core 16 is relatively small, so that each collision energy becomes relatively small, and wear of the contact portion between the second guide bush 19 and the movable core 16 is prevented. , Collision noise can be kept small. In addition, when the stopper member 22 collides with the movable core 16, the valve spring 33 is deformed more than the amount of compressive deformation at the time of normal opening, so that the valve spring 33 absorbs the collision energy of the stopper member 22 against the movable core 16, The impact force will be eased.

  When the sliding member 20 is made of a weak magnetic material, a minute magnetic force is generated between the sliding member 20 and the movable core 16, and the overshoot amount of the valve body 15 can be reduced. . Therefore, when the valve is opened, the impact force caused by the collision between the stopper member 22 and the movable core 16 is reduced or eliminated, and the above-described effect becomes more remarkable and variations in fuel injection can be suppressed.

  When the valve body 15 is opened, the fuel pressure-fed from the fuel pump (not shown) to the fuel inlet cylinder 7 is contained in the pipe-like retainer 32, the hollow portion 6b of the fixed core 6, the flat portion 26 around the sliding member 20, and the movable member. The engine passes from the fuel injection hole 10 through the through hole 24 of the core 16, the inside of the valve housing 2, the fuel flow path 21 inside the first guide bush 18, the flat portion 25 around the valve body 15, the valve seat 8, and the valve hole 9. Is directly injected into the combustion chamber 1a.

  Next, when the energization to the coil 37 is interrupted, first, as shown in FIG. 4F, the sliding member 20 is pushed forward by the repulsive force of the valve spring 33. Then, the valve body 15 is lowered forward with the valve body 15 to seat the valve portion 15a on the valve seat. At this time, the movable core 16 is affected by the residual magnetism between the movable core 16 and the set load of the auxiliary spring 34 that lowers the movable core 16 forward, so that the load on the valve seat 8 of the valve portion 15a is relatively small. Lowers slightly after sitting.

  By the way, when the valve body 15 is first seated on the valve seat 8, the valve body 15 rebounds backward due to the seating impact, but as shown in FIG. By abutting against the stopper member 22 fixed to the body 15, the amount of rebound of the valve body 15 can be minimized.

  When the rebound of the valve body 15 is suppressed, as shown in FIG. 4 (H), the valve body 15 is held in the closed state by the repulsive force of the valve spring 33 to stop the fuel injection, and the movable core 16 is assisted. The spring 34 is held in contact with the stopper member 22 by the repulsive force.

  As described above, in the valve closing process of the valve body 15, the impact force that the valve body 15 applies to the valve seat 8 includes the impact force when only the valve body 15 is first seated on the valve seat 8, and then the movable core 16. Is divided into impact force when it collides with the stopper member 22, so that the collision energy is relatively small. Further, when the valve body 15 is first seated on the valve seat 8, it bounces off due to its seating impact, and then descends and sits again on the valve seat 8 to give an impact, but the valve body 15 is closed after the valve body 15 bounces back. Since the stroke is much smaller than the valve closing stroke from the normal valve opening position of the valve body 15, the impact force exerted on the valve seat 8 again is extremely small. As described above, it is possible to prevent the seat portion between the valve portion 15a and the valve seat 8 from being worn, and to reduce the seating noise.

  The valve body 15 includes a spherical valve portion 15a and a sliding member 20 fixed to the stem 15b. The valve body 15 includes a first guide bush 18 of the valve seat member 3 and a second guide bush 19 of the fixed core 6. Since each is slidably supported, the support span of the valve body 15 can be set longer than the distance between the valve seat 8 and the fixed core 6, the valve body 15 can be stably opened and closed, and fuel injection can be performed. It is possible to prevent the flow rate characteristics from becoming distorted. Moreover, since the second guide bush 19 is made of a nonmagnetic or weak magnetic material having a hardness higher than that of the fixed core 6, the second guide bush 19 has high wear resistance, stabilizes the open / close posture of the valve body 15 over a long period of time, and the fuel injection valve The fuel injection flow rate characteristic of I can be further stabilized.

  Further, since the hardness of the second guide bush 19 and the sliding member 20 are set to be approximately equal, both the wear resistance of the both 19 and 20 can be improved, and the opening and closing posture of the valve body 15 can be made more stable over a long period of time. it can.

  Further, when the coil 37 is energized, the movable core 16 comes into contact with the front end surface of the second guide bush 19 projecting from the suction surface of the fixed core 6, and the sliding member 20 comes into contact with the rear end surface of the movable core 16. The valve opening position of the valve body 15 is defined, and the movable core 16 faces the suction surface 6a of the fixed core 6 with the air gap g interposed therebetween, so that direct contact with the fixed core 6 is avoided. Due to the fact that the guide bush 19 is nonmagnetic or weakly magnetic, when the coil 37 is turned off, it contributes to the rapid disappearance of the residual magnetism between the cores 6 and 16, and the valve closing response of the valve body 15 Can be increased.

  As described above, the second guide bush 19 has a function of slidably supporting the sliding member 20 to stabilize the opening / closing posture of the valve body 15 and a direct connection between the movable core 16 and the fixed core 6 when the coil 37 is energized. It also has the function of improving the valve closing response by avoiding the contact, and it is possible to achieve both the stabilization of the fuel injection characteristics and the simplification of the structure.

  A plurality of flat portions 25 serving as fuel flow paths are formed between the outer peripheral surface of the valve body 15 and the first guide bush 18, and a flat portion 26 serving as a fuel flow path is also provided on the outer peripheral surface of the sliding member 20. Therefore, the sliding surfaces of the valve portion 15a and the first guide bush 18, the sliding member 20 and the second guide bush 19 are effectively lubricated by the fuel passing through the flat portion 25 and the flat portion 26. Can contribute to the improvement of their wear resistance.

  The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the invention. For example, the fuel injection valve I can be configured to inject fuel into the intake system of the engine. The stopper member 22 can also be formed integrally with the stem 15b of the valve body 15. Further, a guide hole may be formed in the valve seat member 3 in place of the first guide bush 18 that slidably supports the valve portion 15a of the valve body 15.

I ... Fuel injection valve s ... Sliding stroke of movable core 2 ... Valve housing 6 ... Fixed core 6a ... Fixed core Suction surface 6b ··· hollow portion 8 of fixed core ··· valve seat 15 ··· valve body 15a ··· valve portion 15b ··· stem 16 ··· movable Core 19 ... guide bush (second guide bush)
20 ... Sliding member 22 ... Stopper member 33 ... Valve spring 34 ... Auxiliary spring 37 ... Coil

Claims (4)

A valve housing (2) having a valve seat (8) at one end, a hollow fixed core (6) connected to the other end of the valve housing (2), and a suction surface (6a) of the fixed core (6) A movable core (16) opposed to the coil, a coil (37) disposed on the outer periphery of the fixed core (6), a valve body (15) cooperating with the valve seat (8), and the valve body And a valve spring (33) for urging (15) in the valve closing direction, and when the coil (37) is energized, the fixed core (6) attracts the movable core (16), thereby the valve body ( 15) In the electromagnetic fuel injection valve that is opened,
A guide bush (19) having a hardness higher than that of the fixed core (6) is fixed to the inner periphery of the fixed core (6), while the valve body (15) is connected to the valve seat (8) to a valve portion (15a). And a stem (15b) connected to the valve portion (15a) and extending toward the guide bush (19). The stem (15b) is connected to the inner peripheral surface of the guide bush (19). A sliding member (20) that is slidably fitted, and a stopper member (22) disposed between the fixed core (6) and the valve portion (15a) are fixed, and the movable core (16) Is slidably fitted to the stem (15b) so that it can move a limited stroke (s) between the sliding member (20) and the stopper member (22), and the coil (37) The movable core (1 is attracted to the fixed core (6) when energized. ) Opens the valve body (15) through the sliding member (20), and when the coil (37) is not energized, the valve body (15) is closed by the urging force of the valve spring (33). An electromagnetic fuel injection valve characterized in that the movable core (16) contacts the stopper member (22) while being valved. The electromagnetic fuel injection valve according to claim 1,
The guide bush (19) is made of a non-magnetic or weak magnetic material, and its front end protrudes from the suction surface (6a) of the fixed core (6). When the coil (37) is energized, the guide bush ( 19) The electromagnetic fuel injection valve, wherein the valve opening limit of the valve body (15) is regulated by bringing the movable core (16) into contact with the front end of 19). The electromagnetic fuel injection valve according to claim 1 or 2,
The valve spring (33) for urging the valve body (15) in the valve closing direction via the sliding member (20) is disposed in the fixed core (6), and the sliding member ( 20) between the movable core (16) and the auxiliary spring (34) for urging the sliding member (20) and the movable core (16) away from each other with a set load smaller than the set load of the valve spring (33). An electromagnetic fuel injection valve characterized by interposing. The electromagnetic fuel injection valve according to claim 3,
A flange portion (20a) for slidably fitting the sliding member (20) to the inner peripheral surface of the guide bush (19), and a shaft portion (20b) protruding from the front end surface of the flange portion (20a) The auxiliary spring (34) is interposed between the front end surface of the flange portion (20a) and the movable core (16), and the shaft portion (34) is inserted into the auxiliary spring (34). 20b), an electromagnetic fuel injection valve.

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