JP2010084552A - Solenoid type fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce impact stress applied to a collision structure to improve reliability, in a solenoid type fuel injection valve having a separate structure of an anchor and a movable element having a valve element. <P>SOLUTION: Part of a fuel passage is narrowed by moving the movable element 114 in opening a valve, or the movable element 114 is abutted on a fixed core 107. Then, the jumping-up amount of the movable element 114 from the anchor 102 is limited, an impact force when the movable element 114 is brought into contact with the anchor 102 is reduced, and reliability of the solenoid type fuel injection valve is improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electromagnetic fuel injection device for an internal combustion engine.

  In an electromagnetic fuel injection valve used in an internal combustion engine, particularly a cylinder fuel injection internal combustion engine, in order to satisfy the regulations and requirements for exhaust gas and fuel consumption, the control range and responsiveness of the flow rate are increased. It is necessary to reduce the post-injection caused by the bounding of the valve body when the valve is closed. Furthermore, in order to inject combustible fuel, the high reliability with respect to a fuel leak is required.

  2. Description of the Related Art Conventionally, a technique for providing a fuel injection valve capable of improving the flow rate control range and responsiveness by separating an anchor and a movable element having a valve body and simultaneously reducing secondary injection (for example, Patent Document 1).

JP 2007-218204 A

  By separating the anchor and the movable element having the valve body, a new collision structure is formed between the anchor and the valve body. If the speed of the valve body is increased to increase the response of the valve body, the impact stress applied to the collision structure portion also increases. Therefore, a technique for improving the reliability is required so that the anchor and the valve body are not deformed or dropped off at the collision structure portion.

  An object of the present invention is to reduce impact stress applied to a collision structure portion and improve reliability in an electromagnetic fuel injection valve in which an anchor and a movable element having a valve body are separate structures.

  A part of the flow path is narrowed by moving the mover when the valve is opened, or the mover is brought into contact with the fixed core. Thereby, the amount of jumping of the mover from the anchor is limited, and the impact force when the mover contacts the anchor again is reduced.

  According to the present invention, there is provided an electromagnetic fuel injection valve that can reduce the impact force in the collision structure portion between the anchor and the mover without providing a new shock absorbing mechanism by a separate member, and has improved reliability. Can be provided.

  Examples according to the present invention will be described below.

  The overall configuration of the embodiment will be described with reference to FIGS.

  The nozzle holder 101 made of a metal material includes a small-diameter cylindrical portion 22 having a small diameter and a large-diameter cylindrical portion 23 having a large diameter, and the two are connected by a conical section 24.

  A nozzle body is formed at the tip of the small diameter cylindrical portion 22. Specifically, an orifice cup 116 having a fuel injection port 116A is inserted into a cylindrical portion formed inside the tip portion of the small-diameter cylindrical portion, and stroke adjustment described later on the cylindrical portion around the orifice cup 116. It is fixed later by welding. A guide member 115 is fixed to the orifice cup 116.

  The guide member 115 guides the outer periphery of a rod portion 114A of a movable element 114, which will be described later, or a valve body portion 114B provided at the tip thereof, and also serves as a fuel guide for guiding fuel from the radially outer side to the inner side.

  A conical valve seat 39 is formed on the orifice cup 116 on the side facing the guide member 115. A valve body 114B provided at the tip of the rod portion 114A is in contact with the valve seat 39, and guides or blocks the flow of fuel to the fuel injection port 116A.

  A groove is formed on the outer periphery of the nozzle body, and a seal member typified by a resin-made chip seal or a gasket in which rubber is baked around a metal is fitted in the groove.

  A mover guide 113 that guides the rod portion 114A of the mover 114 is press-fitted and fixed to the drawing portion of the large-diameter tubular portion 23 at the lower end of the inner periphery of the large-diameter tubular portion 23 of the nozzle holder 101 made of a metal material. ing.

  A guide hole 127 for guiding the rod portion 114A is provided at the center of the mover guide 113, and a plurality of fuel passages 126 are perforated around it.

  Further, a concave portion is formed on the central upper surface by extrusion. A spring 112 is held in the recess.

  A convex portion corresponding to the concave portion is formed by extrusion on the lower surface of the center of the mover guide 113, and a guide hole 127 of the rod portion 114A is provided at the center of the convex portion.

  Thus, the elongated rod portion 114 </ b> A is guided to reciprocate straight by the guide hole 127 of the mover guide 113 and the guide hole of the guide member 115.

  A head portion 114C having stepped portions 129 and 133 having outer diameters larger than the diameter of the rod portion 114A is provided at the end portion of the rod portion 114A opposite to the end portion where the valve body portion 114B is provided. . A seating surface of the spring 110 is provided on the upper end surface of the stepped portion 133, and a spring guide projection 131 is formed at the center.

  The mover 114 has an anchor 102 having a through hole in the center through which the rod portion 114A passes. The anchor 102 has a spring receiving recess 112A formed in the center of the surface facing the mover guide 113, and the spring 112 is held between the recess 125 of the mover guide 113 and the recess 112A. .

  Since the diameter of the through hole 128 is smaller than the diameter of the stepped portion 133 of the head portion 114C, under the action of the biasing force of the spring 110 or gravity that presses the rod portion 114A toward the valve seat of the orifice cup 116, The inner peripheral lower end surface 129 of the stepped portion 133 of the head portion 114C of the rod portion 114A is in contact with the bottom surface of the recess 123 formed on the upper side surface of the anchor 102 held by the spring 112, and both are engaged. .

  Thus, both of the two members cooperate with each other for the upward movement of the anchor 102 against the urging force or gravity of the spring 112 or the downward movement of the rod portion 114A along the urging force of the spring 112 or gravity. It will move.

  However, when the force to move the rod portion 114A upward or the force to move the anchor 102 downward independently of each other regardless of the urging force or gravity of the spring 112, both of them should move in different directions. And

  At this time, a minute gap of 5 to 15 microns is provided between the outer peripheral surface of the rod portion 114A and the inner peripheral surface of the anchor 102 at the portion of the through hole 128 so that the mover moves smoothly. The minute gap causes the fluid film to rub against movement in different directions, thereby suppressing the movement of both. In other words, the brake is applied to the rapid displacement of both, and hardly resists the slow movement. Such instantaneous movements in opposite directions of both of them are attenuated in a short time.

  Here, the anchor 102 is not positioned between the inner peripheral surface of the large-diameter cylindrical portion 23 and the outer peripheral surface of the anchor 102, but by the inner peripheral surface of the through hole 128 of the anchor 102 and the outer peripheral surface of the rod portion 114A. Is held. The outer peripheral surface of the rod portion 114A functions as a guide when the anchor 102 moves alone in the axial direction.

  Although the lower end surface of the anchor 102 faces the upper end surface of the mover guide 113, the springs 112 are interposed so that they do not contact each other.

  A side gap is provided between the outer peripheral surface of the anchor 102 and the inner peripheral surface of the large-diameter cylindrical portion 23 of the nozzle holder 101 made of a metal material. This side gap allows a small gap of 5 to 15 microns formed between the outer peripheral surface of the rod portion 114A and the inner peripheral surface of the anchor 102 at the portion of the through hole 128 to allow the axial movement of the anchor 102. It is larger, for example, about 0.1 millimeter. If the magnetic resistance is too large, the magnetic resistance becomes large, so this gap is determined in consideration of the magnetic resistance.

  A fixed core 107 is press-fitted and welded to the inner peripheral portion of the large-diameter cylindrical portion 23 of the nozzle holder 101 made of a metal material. By this welding joining, a fuel leakage gap formed between the inside of the large-diameter cylindrical portion 23 of the nozzle holder 101 made of a metal material and the outside air is sealed.

  The lower end of the initial load setting spring 110 is in contact with the spring seat 117 formed on the upper end surface of the stepped portion 133 provided on the head portion 114C of the rod portion 114A, and the other end of the spring 110 is fixed. It is fixed between the head 114 </ b> C and the adjuster 54 by being received by the adjuster 54 press-fitted into the through hole of the core 107.

  By adjusting the fixing position of the adjuster 54, the initial load with which the spring 110 presses the valve body portion 114B against the valve seat 39 can be adjusted.

  The stroke of the anchor 102 is adjusted by attaching the electromagnetic coil (104, 105) and the housing 103 to the outer periphery of the large diameter cylindrical portion 23 of the nozzle holder 101, and then moving the anchor 102 into the large diameter cylindrical portion 23 of the nozzle holder 101. With the rod portion 114A inserted through the anchor 102, the rod portion 114A is pushed down to the valve closing position by a jig, and the stroke of the mover 114 when the coil 105 is energized is detected. By determining the press-fitting position, the stroke of the mover 114 can be adjusted to an arbitrary position.

  As shown in FIGS. 1 and 2, with the initial load of the initial load setting spring 110 adjusted, the lower end surface of the fixed core 107 is about 40 to 100 microns with respect to the upper end surface 122 of the anchor 102 of the mover 114. The magnetic attraction gaps (exaggerated in the drawing) are arranged to face each other.

  The outer diameter of the anchor 102 and the outer diameter of the fixed core 107 are very small (about 0.1 millimeter), and the outer diameter of the anchor 102 is small. On the other hand, the inner diameter of the through hole 128 positioned at the center of the anchor 102 is slightly larger than the outer diameter of the rod portion 114A of the movable element 114 and the valve body. The outer diameter of the head portion 114 </ b> C is larger than the inner diameter of the through hole 128 of the anchor 102.

  Accordingly, the axial engagement margin between the lower end surface of the head portion 114C of the rod portion 114A and the bottom surface of the recess 123 of the anchor 102 is ensured while sufficiently securing a magnetic path area in the magnetic attraction gap.

  A housing 103 is fixed to the outer periphery of the large-diameter cylindrical portion 23 of the nozzle holder 101 made of a metal material.

  A through hole is provided in the center of the bottom of the housing 103, and the large-diameter cylindrical portion 23 of the nozzle holder 101 made of a metal material is inserted through the through hole.

  An annular or cylindrical electromagnetic coil 105 is disposed in a cylindrical space formed by the housing 103 and the annular core large diameter portion 106.

  The electromagnetic coil 105 includes an annular coil bobbin 104 having a U-shaped groove that opens outward in the radial direction, and an annular electromagnetic coil 105 formed of a copper wire wound in the groove. Has been.

  The electromagnetic coil device includes a coil bobbin 104, an electromagnetic coil 105, a housing 103, and a fixed core 107.

  A rigid conductor 109 is fixed to the winding start and winding end of the electromagnetic coil 105, and the conductor 109 is drawn out from a through hole provided in the core large diameter portion 106.

  The outer periphery of the large-diameter cylindrical portion 23 of the conductor 109, the fixed core 107, and the nozzle holder 101 is molded by injecting an insulating resin into the inner periphery of the upper end opening of the housing 103 and above the core large-diameter portion 106. 121.

  Thus, a toroidal magnetic path indicated by the arrow 201 is formed around the coil bobbin 104 and the electromagnetic coil 105.

  The connector formed at the tip of the conductor 109 is connected to a plug for supplying electric power from a battery power source, and energization / non-energization is controlled by a controller (not shown).

  While the electromagnetic coil 105 is energized, a magnetic attraction force is generated between the anchor 102 of the mover 114 and the fixed core 107 in the magnetic gap by the magnetic flux passing through the magnetic path 201, and the anchor 102 exceeds the set load of the spring 110. It moves upwards when it is sucked in. At this time, the anchor 102 engages with the head portion 114 </ b> C of the mover, moves upward together with the rod portion 114 </ b> A, and moves until the upper end surface of the anchor 102 collides with the lower end surface of the fixed core 107.

  As a result, the valve body 114B at the tip of the rod portion 114A is separated from the valve seat, and fuel passes through the fuel passage and is ejected from the plurality of injection ports 116A into the combustion chamber.

  The mover 114 continues to move upward due to the inertial force even after the anchor 102 collides with the lower end surface of the fixed core 107, and the engaged mover head 114C and the anchor 102 move away and jump up.

  The mover 114 decelerates due to the force of the spring 110 and the friction between the outer peripheral surface of the rod portion 114A and the inner peripheral surface of the anchor 102, temporarily stops, is pushed back again by the force of the spring 110, and moves downward. The head 114C of the mover and the anchor 102 collide and stop.

  When the energization to the electromagnetic coil 105 is cut off, the magnetic flux in the magnetic path 201 disappears and the magnetic attractive force in the magnetic attractive gap also disappears.

  In this state, the spring force of the initial load setting spring 110 that pushes the head portion 114C of the rod portion 114A in the opposite direction overcomes the force of the spring 112 and acts on the entire movable element 114 (anchor 102, rod portion 114A).

  As a result, the anchor 102 of the mover 114 that has lost the magnetic attractive force is pushed back to the closed position where the valve body 114B contacts the valve seat by the spring force of the spring 110.

  At this time, the stepped portion 129 of the head portion 114 </ b> C contacts the bottom surface of the recess 123 of the anchor 102 to overcome the force of the spring 112 and move the anchor 102 to the mover guide 113 side.

  When the valve body portion 114B collides with the valve seat vigorously, the rod portion 114A rebounds in the direction of compressing the spring 110.

  However, since the anchor 102 has a separate structure from the rod portion 114A, the rod portion 114A moves away from the anchor 102 in the direction opposite to the movement of the anchor 102. Here, the anchor 102 and the rod portion 114A have a separate structure. The anchor 102 and the rod portion 114A are not fixed, and the anchor 102 is relative to the rod portion 114A in the axial direction of the rod portion 114A. It means that it can be displaced.

  At this time, friction due to the fluid is generated between the outer periphery of the rod portion 114A and the inner periphery of the anchor 102, and the energy of the rebounding rod portion 114A is still moving in the opposite direction (valve closing direction) due to inertial force. Absorbed by the inertial mass of the anchor 102.

  Since the anchor 102 having a large inertial mass is separated from the mover 114 at the time of rebounding, the rebounding energy itself is also reduced.

  Further, since the anchor 102 that has absorbed the rebound energy of the rod portion 114A reduces its inertial force, the energy for compressing the spring 112 is reduced, and the repulsive force of the spring 112 is reduced. The phenomenon that the movable part 114A is moved in the valve opening direction due to the rebounding phenomenon is less likely to occur.

  Thus, the bounce of the mover 114 is minimized, and the so-called secondary injection phenomenon in which the valve is opened after the energization of the electromagnetic coil 105 is cut off and the fuel is injected randomly is suppressed.

  The anchor 102 is made of magnetic stainless steel with good workability suitable for forging, and at least the end face that collides with the fixed core 107 and the surrounding surface thereof are plated with chromium (Cr) or Ni (nickel).

  Here, the fuel injection valve is required to be able to open and close in response to a valve opening signal input by applying a current to the terminal 109. That is, the delay time from the rise of the valve opening pulse signal to the actual valve opening state (valve opening delay time), or the delay time from the end of the valve opening pulse signal to the actual valve closing state (closed) Reduction of the valve delay time is also important from the viewpoint of reducing the minimum controllable injection amount (minimum injection amount).

  In particular, it is known that shortening the valve closing delay time is particularly effective for reducing the minimum injection amount. For this reason, it is desirable that the set load of the spring 110 for biasing the force for shifting the valve body from the open state to the closed state is large.

  That is, when the set load of the spring 110 is large, the force for driving the mover 114 is increased, the valve is easily closed against the remaining electromagnetic force and fluid resistance force, and the valve closing delay time can be shortened. In order to increase the set load of the spring 110 in this way, the mover 114 opens against the strong spring set load, and in order to maintain the open state, the mover 114 is large between the fixed core 107 and the anchor 102. Magnetic attraction is required.

  It is also important to increase the maximum controllable injection amount (maximum injection amount) in order to expand the control range of the injection amount. For this purpose, it is necessary to increase the pressure of the fuel. When the fuel pressure rises, the force in the valve closing direction by the fuel applied to the mover 114 during the valve opening increases. A large magnetic attractive force is required to open the movable element 114 against the force of the fuel in the valve closing direction and maintain the open state.

  For this reason, in order to improve the responsiveness of valve opening / closing and widen the control range of the injection amount, it is necessary to obtain a sufficiently large magnetic attractive force, and the speed of the mover 114 at the time of valve opening increases. Become.

  When the moving speed of the movable element 114 increases, the upward moving speed when the movable element 114 jumps off the anchor 102 when the valve is opened also increases. Therefore, the amount of jump of the movable element 114 from the anchor 102 increases, and the impact force when the movable element head 114 </ b> C collides with the anchor 102 by being pushed back downward by the spring 110 also increases. In consideration of the mechanical properties of the material, when the impact force increases as the anchor 102 or the head portion 114C of the mover is deformed and dented, the stroke amount of the mover 114 is reduced and the flow rate is reduced.

  Since the mover 114 detaches from the anchor 102 and jumps up every time the valve is opened, when the number of operation of the fuel injection valve is large, even if the impact force acting on the anchor 102 and the head 114C of the mover is smaller than the yield strength, The collision structure may be deformed by metal fatigue.

  Therefore, it is important to reduce the impact force at the time of collision due to separation between the bottom surface of the concave portion 123 of the anchor and the stepped portion 129 of the mover.

  Here, the first embodiment will be described with reference to FIG.

  In the first embodiment, the central through hole of the fixed core 107 is slightly larger than the outer periphery of the mover head 114C. Therefore, the mover 114 can move in the axial direction without contacting the fixed core 107.

  The width from the upper surface of the anchor 102, which is the surface facing the lower end portion of the fixed core 107, to the bottom surface of the concave portion 123 of the anchor is from the lower end surface of the stepped portion 129 of the head 114 </ b> C of the mover to the stepped portion 133. It is wider than the width to the top surface. Therefore, when the bottom surface of the concave portion 123 of the anchor is in contact with the lower end surface of the stepped portion 129 of the mover, the upper surface of the stepped portion 133 of the mover is configured below the lower end surface of the fixed core 107. (Exaggerated in the drawing).

  Further, the outer periphery of the head 114C of the mover in a state in which the anchor 102 is sucked and abutted on the fixed core 107 and the bottom surface of the anchor recess 123 and the lower end surface of the stepped portion 129 of the mover are in contact with each other. A gap between the portion 134 and the lower end surface of the fixed core 107 is defined as a gap 301A.

  The gap 301A is narrower than the amount of jump of the movable element 114 when no fuel is contained inside the electromagnetic fuel injection valve (exaggerated in the drawing).

  Therefore, when fuel is not contained in the electromagnetic fuel injection valve, after the anchor 102 is attracted to and collides with the fixed core 107, the movable element 114 jumps up, and the upper surface of the stepped portion 133 of the movable element is fixed. It reaches the upper side from the lower end surface 132 of the core 107.

  When using a liquid fuel that is considered to be incompressible, if the gap 301A is sufficiently small, the upper end surface of the stepped portion 133 of the valve body head portion 114C extends above the lower end surface 132 of the fixed core 107 due to fluid resistance. Never move.

  By limiting the amount of jump of the movable element 114 as described above, the distance until the movable element 114 is pushed back again by the force of the spring 110 and moves downward to collide with the anchor 102 is shortened. The speed of the mover 114 is reduced, and the impact force caused by the collision between the anchor 102 and the mover 114 is reduced.

  When fuel is used, the fluid resistance of the flowing fuel is increased by narrowing the gap 301A in this way, the upward movement of the mover 114 is inhibited, and the impact force due to the collision between the mover 114 and the anchor 102 is reduced. There is a reduction effect.

  Further, by limiting the amount of jumping and reducing the speed at the time of collision, the time from when the movable element 114 jumps up to the return to the anchor 102 is shortened. As a result, the time during which the valve closing can be started stably becomes earlier, and the minimum injection amount can be reduced.

  When the movable element 114 is not lifted up, that is, when the lower end surface of the stepped portion 129 of the movable element is in contact with the concave portion 123 of the anchor, the gap 301A is obtained to obtain a necessary injection flow rate. It must be open to the extent that it does not impede fuel flow.

  In order not to hinder the flow of fuel, it is only necessary to ensure a larger cross-sectional area than the smallest part of the fuel passage in the electromagnetic fuel injection valve. Even when the valve is open in this structure, the fuel passage between the conical valve seat 39 of the orifice cup 116 and the valve body 114B is the narrowest, and the gap 301A between the head 114C of the mover and the anchor 102 is at least 4 microns. I just need it.

  The gap 301A temporarily becomes 4 microns or less due to the jumping of the mover 114, and the flow of fuel may be obstructed. However, the jumping time is 0.1 ms, which is sufficiently shorter than the entire valve opening time. There is no problem with the injection flow rate. In addition, since the amount of jumping up is reduced, the amount of fluctuation in the amount of jumping up for each injection is also reduced, so that the on-off valve operation at each time is stabilized and the variation in fuel injection amount can be reduced.

  Here, according to an example of the movement amount graph of the mover 114 when the present invention shown in FIG. 3 is not used or when fuel is not contained, the jump amount of the mover 114 is 40 microns.

  Therefore, if the gap 301A is 4 to 40 microns, the impact force due to the collision between the movable element 114 and the anchor 102 can be reduced without hindering the fuel and the flow.

  Here, the second embodiment will be described with reference to FIG.

  In the second embodiment, the central through hole of the fixed core 107 is smaller than the outer periphery of the mover head 114C. Therefore, the upward movement of the mover 114 is restricted by contact between the upper surface of the stepped portion 133 of the mover and the lower end surface 132 of the fixed core.

  The width from the upper surface of the anchor to the bottom surface of the recess 123 is wider than the width from the lower end surface of the stepped portion 129 of the head 114C of the mover to the upper end surface of the stepped portion 133. For this reason, when the bottom surface of the concave portion 123 of the anchor is in contact with the lower end surface of the stepped portion 129 of the mover, the upper surface of the stepped portion 133 of the mover is slightly lower than the lower end surface of the fixed core 107. (Exaggerated in the drawing).

  In addition, the step of the head 114C of the mover in a state where the anchor 102 is attracted to and abuts on the fixed core 107 and the bottom surface of the anchor recess 123 and the lower end surface of the step 129 of the mover are in contact with each other. A gap between the upper end surface of the attachment portion 133 and the lower end surface 132 of the fixed core 107 is defined as a clearance 301B.

  After the mover 114 is attracted to and collides with the fixed core 107, the upper end surface of the stepped portion 133 of the mover collides with the lower end surface 132 of the fixed core 107 when the mover 114 detaches from the anchor 102 and jumps up. Thus, the gap 301B is adjusted in advance according to the depth of the concave portion 123 of the anchor and the height of the stepped portions 129 and 133 of the head portion 114C of the mover.

  Since the amount of jump of the movable element 114 is regulated by the gap 301, the distance from when the movable element 114 is pushed back again by the force of the spring 110 to move downward and collide with the anchor 102 can be limited to be short. If the gap 301 is sufficiently small when the mover 114 approaches the fixed core 107, the vertical movement of the mover 114 is hindered by the liquid damper effect by the gap 301 and decelerates. Therefore, the speed of the movable element 114 at the time of the collision can be reduced, and the impact force due to the collision between the anchor 102 and the movable element 114 can be reduced.

  When fuel is used, the clearance 301B is defined in this way, so that the amount of jump of the mover 114 is limited, and the mover 114 is decelerated by the liquid damper effect of the fuel, so that the mover 114 and the anchor are fixed. There is an effect of reducing the impact force due to the collision of 102.

  In addition, by reducing the amount of jumping and reducing the speed at the time of collision, the time from when the movable element 114 jumps up to the return to the anchor 102 is shortened. As a result, the time during which the valve closing can be started stably becomes earlier, and the minimum injection amount can be reduced.

  When the movable element 114 is not lifted up, that is, when the lower end surface of the stepped portion 129 of the movable element and the bottom surface of the concave portion 123 of the anchor are in contact with each other, a gap is obtained to obtain a necessary injection flow rate. 301B needs to be open to the extent that the flow of fuel is not hindered.

  In order not to hinder the flow of fuel, it is only necessary to ensure a larger cross-sectional area than the smallest part of the fuel passage in the electromagnetic fuel injection valve. Even when the valve is open in this structure, the fuel passage between the conical valve seat 39 of the orifice cup 116 and the valve body 114B is the narrowest, and the gap 301B between the head 114C of the mover and the anchor 102 is at least 4 microns. That's fine.

  The gap 301B temporarily becomes 4 microns or less due to the jumping of the mover 114, which may impede the flow of fuel. However, the jumping time is 0.1 ms, which is sufficiently small compared to the entire valve opening time. There is no problem with the injection flow rate. In addition, since the amount of jumping up is reduced, the amount of fluctuation in the amount of jumping up for each injection is also reduced, so that the on-off valve operation at each time is stabilized and the variation in fuel injection amount can be reduced.

  Here, according to an example of the moving amount graph of the movable element 114 when the present invention is not used as shown in FIG. 3, the jumping amount of the movable element 114 is 40 microns.

  Therefore, if the gap 301B is 4 to 40 microns, there is an effect of reducing the impact force caused by the collision between the mover 114 and the anchor 102 without hindering the fuel and the flow.

  Here, the third embodiment will be described with reference to FIGS.

  In the third embodiment, the central through-hole of the fixed core 107 is smaller than the outer periphery of the mover head 114C. Therefore, the upward movement of the mover 114 is restricted by the upper surface of the stepped portion 133 of the mover contacting the lower end surface 132 of the fixed core 107.

  The width from the upper surface of the anchor to the concave portion 123 is slightly smaller than the width from the lower end surface of the stepped portion 129 of the mover to the upper surface of the stepped portion 133. Therefore, when the bottom surface of the concave portion 123 of the anchor is in contact with the lower end surface of the stepped portion 129 of the mover, the upper surface of the stepped portion 133 of the mover is configured above the upper surface of the anchor 102 ( It is exaggerated in the drawing).

  Here, FIG. 6 shows a view of the mover 114 as viewed from above. A notch 136 is provided in a part of the outer periphery of the stepped portion 133 of the mover. The notch 136 reaches the center side from the central through hole of the fixed core 107. When the upper surface of the stepped portion 133 of the mover comes into contact with the lower end surface 132 of the fixed core 107, the anchor recess is formed from the central through hole of the fixed core 107 through the outer peripheral side of the notch 136 of the mover 114. A fuel passage communicating with 123 is formed.

  When the anchor 102 is attracted to the fixed core 107 by energizing the electromagnetic coil 105, the movable element 114 that engages with the concave portion 123 of the anchor also moves upward. At this time, since the upper surface of the stepped portion 133 of the mover is closer to the lower end surface 132 of the fixed core 107 than the upper surface of the anchor 102, the stepped portion 133 of the mover 114 collides with the lower end surface 132 of the fixed core 107. .

  The movable element 114 rebounds downward after colliding with the fixed core 107. Since the bottom surface of the anchor concave portion 123 and the lower surface of the stepped portion 129 of the head portion 114 </ b> C of the mover are engaged, the anchor 102 also rebounds integrally with the mover 114.

  The anchor 102 is attracted again to the fixed core 107 by the magnetic attraction force to the spring 112 and the fixed core 107. At this time, the movable element 114 does not receive a downward force from other than the anchor 102, so that the movable element 114 comes into contact with the fixed core 107 without moving away from the anchor 102 and stops.

  Thus, by causing the movable element 114 and the fixed core 107 to collide, the jumping of the movable element 114 from the anchor 102 is eliminated, and the impact force caused by the collision between the anchor 102 and the movable element 114 when the valve is opened is reduced.

  Here, the fourth embodiment will be described with reference to FIG.

  In the fourth embodiment, the central through hole of the fixed core 107 is smaller than the outer periphery of the mover head 114C. Therefore, the upward movement of the mover 114 is restricted by the upper surface of the stepped portion 133 of the mover contacting the lower end surface 132 of the fixed core 107.

  The width from the upper surface of the anchor to the recess 123 is equal to the width from the lower end surface of the stepped portion 129 of the mover to the upper surface of the stepped portion 133. Therefore, when the bottom surface of the concave portion 123 of the anchor is in contact with the lower end surface of the stepped portion 129 of the mover, the upper surface of the stepped portion 133 of the mover is configured on the same plane as the upper surface of the anchor 102. The

  Similarly to the case of the third embodiment, a notch 136 is provided in a part of the outer peripheral portion of the stepped portion 133 of the mover shown in FIG. The notch 136 reaches the center side from the central through hole of the fixed core 107. When the upper surface of the stepped portion 133 of the mover comes into contact with the lower end surface 132 of the fixed core 107, the anchor recess is formed from the central through hole of the fixed core 107 through the outer peripheral side of the notch 136 of the mover 114. A fuel passage communicating with 123 is formed.

  When the anchor 102 is attracted to the fixed core 107 by energizing the electromagnetic coil 105, the mover 114 that engages with the bottom surface of the concave portion 123 of the anchor also moves upward. At this time, since the upper surface of the anchor 102 is flush with the upper surface of the stepped portion 133 of the mover, the anchor 102 and the mover 114 collide with the lower end surface 132 of the fixed core 107 at the same time.

  After the anchor 102 and the movable element 114 collide with the fixed core 107, they are united and rebound downward. The anchor 102 is attracted again to the fixed core 107 by the magnetic attraction force to the spring 112 and the fixed core 107. At this time, the movable element 114 does not receive a downward force from other than the anchor 102, so that the movable element 114 comes into contact with the fixed core 107 without moving away from the anchor 102 and stops.

  Thus, by causing the mover 114 and the anchor 102 to collide with the fixed core 107 at the same time, the jump of the mover 114 from the anchor 102 is eliminated, and the impact force due to the collision between the anchor 102 and the mover 114 is reduced.

  The present invention relates to a so-called electromagnetic fuel injection valve driven by an electromagnetic coil, which is a fuel injection valve for an internal combustion engine.

It is sectional drawing which shows the whole fuel-injection valve with which this invention is implemented. It is sectional drawing to which the magnetic path part of the fuel injection valve with which 1st Example of this invention was implemented was expanded. It is the figure which showed the moving amount | distance of a needle | mover when not utilizing this invention or containing fuel. It is sectional drawing to which the magnetic path part of the fuel injection valve with which 1st Example of this invention was implemented was expanded. It is the figure which showed the needle | mover of the fuel injection valve with which 3rd Example or 4th Example of this invention was implemented. It is sectional drawing to which the magnetic path part of the fuel injection valve with which 3rd Example of this invention was implemented was expanded. It is sectional drawing to which the magnetic path part of the fuel injection valve with which 4th Example of this invention was implemented was expanded.

Explanation of symbols

39 Valve seat 54 Adjuster 101 Nozzle holder 102 Anchor 103 Housing 104 Coil bobbin 105 Electromagnetic coil 107 Fixed core 109 Conductor 110 Spring 112 Spring 113 Mover guide 114 Mover 114A Rod part 114B Valve body part 114C Head part 115 Guide member 116 Orifice cup 117 Spring receiving seat 121 Resin molding 123 Anchor recesses 129 and 133 Movable stepped portion 131 Movable projection 132 Lower end surface 201 of fixed core Magnetic path 301A, 301B Gap

Claims (10)

A fixed core provided with a through-hole which is a fuel passage in the center, a coil disposed on the outer peripheral side of the fixed core, an anchor having an upper end surface facing the lower end surface of the fixed core, and a valve at the lower end A movable body having a body portion, and the anchor and the movable body have a separate structure, and a magnetic attraction force is generated by energizing the coil to connect the anchor and the movable body. In the electromagnetic fuel injection valve configured to be sucked into the fixed core,
When the anchor is sucked into the fixed core, the amount of jumping up of the mover from the anchor is limited by using a fluid resistance acting on a gap between the mover and the fixed core. An electromagnetic fuel injection valve.   The electromagnetic fuel injection valve according to claim 1, wherein the anchor is configured to be able to contact the fixed core, and the fixed core can move the movable element even after the anchor and the fixed core are in contact. In order not to disturb, the head of the movable element is configured to be smaller than the through-hole in the center of the fixed core, and when the movable element moves and the gap with the fixed core is narrowed, fluid resistance is generated, and the movable element is moved. An electromagnetic fuel injection valve characterized in that it is configured in a positional relationship in which is limited.   3. The electromagnetic fuel injection valve according to claim 2, wherein a gap between an outer peripheral corner of the head of the mover and a lower end surface of the fixed core is bounced up when the valve is opened when fuel is not contained. An electromagnetic fuel injection valve configured to be narrower than the amount.   4. The electromagnetic fuel injection valve according to claim 3, wherein a gap between an outer peripheral corner of the head of the movable element and a lower end surface of the fixed core is 4 to 40 microns. . A fixed core provided with a through-hole which is a fuel passage in the center, a coil disposed on the outer peripheral side of the fixed core, an anchor having an upper end surface facing the lower end surface of the fixed core, and a valve at the lower end A movable body having a body portion, wherein the anchor and the movable body are separate structures, and the anchor sucked into the fixed core is configured to be able to contact the fixed core, and the coil In an electromagnetic fuel injection valve configured to generate a magnetic attraction force by energizing to the anchor and the mover to the fixed core,
When the anchor and the mover are sucked into the fixed core, the mover is brought into contact with the fixed core to limit the amount of movement of the mover from the through hole in the center of the fixed core. An electromagnetic fuel injection valve characterized in that the head of the mover is configured to be large.   6. The electromagnetic fuel injection valve according to claim 5, wherein when the anchor and the movable element are sucked into the fixed core, the movable element and the fixed core are brought into contact with each other after the anchor and the fixed core come into contact with each other. An electromagnetic fuel injection valve characterized in that the amount of movement of the mover is limited by contact.   7. The electromagnetic fuel injection valve according to claim 6, wherein a gap formed between a lower end surface of the fixed core and an upper surface of the movable element facing the lower end surface is opened when fuel is not contained. An electromagnetic fuel injection valve configured to be smaller than a jumping amount of the movable element.   8. The electromagnetic fuel injection valve according to claim 7, wherein a gap formed between a lower end surface of the fixed core and an upper surface of the movable element facing the lower end surface is 4 to 40 microns. Fuel injection valve.   6. The electromagnetic fuel injection valve according to claim 5, wherein when the anchor and the mover are sucked into the fixed core, the mover contacts the fixed core before the anchor. The mover has a positional relationship in which the mover protrudes from the anchor toward the fixed core while being in contact with the anchor, and the head of the mover is configured to be larger than the through-hole in the center of the fixed core. Fuel injection valve.   6. The electromagnetic fuel injection valve according to claim 5, wherein when the anchor and the mover are attracted to the fixed core, the mover contacts the fixed core simultaneously with the anchor. Is in a state where the surface of the mover facing the fixed core and the surface of the anchor are in the same plane in a state of being in contact with the anchor, and the head of the mover from the through hole in the center of the fixed core An electromagnetic fuel injection valve characterized by comprising a large part.

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