JP5218487B2 - Fuel injection valve - Google Patents

Description

  The present invention relates to a fuel injection valve that injects fuel from an injection hole to an internal combustion engine.

  Conventionally, the magnetic attraction force for moving the movable core toward the fixed core is generated by energizing the coil in the valve opening operation that opens the nozzle hole of the valve housing, while the energization is stopped in the valve closing operation that closes the nozzle hole. Fuel injection valves that are extinguished by are known.

  In the one disclosed in Patent Documents 1 and 2 as a kind of such fuel injection valve, a valve member that opens and closes an injection hole by reciprocating movement to interrupt fuel injection protrudes from a valve penetrating part that penetrates the movable core. A flange capable of abutting from the fixed core side is provided. According to this fuel injection valve, when starting the valve opening operation from the state in which the nozzle hole is closed and opening the nozzle hole, against the flange of the valve member that is biased to the opposite side of the fixed core by the restoring force of the spring, The movable core that has received the magnetic attraction force contacts from the fixed core side. As a result, when the movable core moves and collides with the fixed core, the valve member continues the movement against the restoring force of the spring by the inertial force, while moving the valve penetrating portion relative to the movable core. The flange is separated from the movable core. Therefore, even if the movable core bounces away from the fixed core due to the collision reaction force, the valve member, whose bounce force is difficult to propagate to the flange, will cause a variation in the fuel injection amount by accidentally closing the injection hole Can be avoided.

JP 2009-108842 A German Patent Application No. 102006046833A1

  Now, in the fuel injection valve disclosed in Patent Document 1, the flange of the valve member and the movable core are brought into contact with each other in a state where energization of the coil is stopped. Therefore, in the valve opening operation for opening the nozzle hole, the magnetic attraction force for moving both the stopped valve member and the movable core must be applied to the movable core from the start of the valve opening operation by energizing the coil. . Therefore, in the initial stage of the valve opening operation, the moving speed of the valve member does not increase, so that the moving time of the valve member necessary to open the nozzle hole becomes long, which is disadvantageous in reducing the minimum fuel injection amount. End up.

  Therefore, in the fuel injection valve disclosed in Patent Document 2, a gap is formed between the flange of the valve member and the movable core in a state where energization of the coil is stopped. As a result, at the start of the valve opening operation, it is sufficient to apply a magnetic attraction force for moving the movable core without the valve member to the movable core by energizing the coil. As a result, the movable core accelerated by moving by the gap between the flange can apply the impact force according to the momentum to the flange by the collision with the flange, so it is necessary to open the nozzle hole. The movement of the valve member for a proper distance can be realized in a short time.

  However, in the fuel injection valve disclosed in Patent Document 2, the size of the gap between the flange and the movable core is controlled by press-fitting and welding the flange to the valve member. For this reason, the size of the gap is likely to vary between the flange and the movable core according to the press-fitted state or welded state of the flange at the time of manufacture. In other words, it is difficult to accurately manage the size of the gap. Therefore, in the valve opening operation, the impact force applied to the flange due to the movement of the movable core corresponding to the gap also varies, so the movement rate of the valve member has a variation rate within a short time as described above. As a result, the control accuracy of the fuel injection amount decreases.

  In addition, in the fuel injection valve disclosed in Patent Document 2, in addition to the first flange that protrudes from the valve penetrating portion and can contact the movable core from the fixed core side, the fuel injection valve protrudes from the valve penetrating portion and is fixed to the movable core. The valve member is provided with a second flange that can contact from the opposite side. At the same time, in the fuel injection valve disclosed in Patent Document 2, in addition to the first spring that biases the valve member to the side opposite to the fixed core, the movable core is interposed between the movable core and the second flange. A second spring is provided for biasing to the opposite side of the fixed core. In such a configuration, when the valve closing operation is started from the state in which the nozzle hole is opened and the nozzle hole is closed, the valve member that is biased to the side opposite to the fixed core by the restoring force of the first spring is One flange is brought into contact with the movable core from the fixed core side. At this time, since the magnetic attractive force is lost, the movable core moves together with the valve member to the opposite side of the fixed core by the restoring force of the first spring. As a result, the second spring of the valve member that is biased to the opposite side of the fixed core by the restoring force of the second spring and stops moving by closing the nozzle hole is applied to the movable core on which the inertial force acts. A flange will contact | abut from the said opposite side. Therefore, the valve member oscillated by the contact between the movable core and the second flange may accidentally open the injection hole, leading to unexpected secondary injection.

  The present invention has been made in view of the problems described above, and an object thereof is to provide a fuel injection valve capable of controlling the fuel injection amount with high accuracy.

  The invention according to claim 1 is a valve housing having an injection hole for injecting fuel to an internal combustion engine, a fixed core fixed to the valve housing, a movable core that moves to the fixed core side by the action of magnetic attraction, A coil that generates a magnetic attractive force by energization in the valve opening operation to open the nozzle hole, while a coil that eliminates the magnetic attraction force by stopping energization in the valve closing operation to close the nozzle hole, a valve penetrating portion that penetrates the movable core, and a valve A valve member that protrudes from the penetrating portion and has a valve protrusion that can come into contact with the movable core from the fixed core side, opens and closes the injection hole by reciprocating movement, and interrupts fuel injection, and the movable core penetrates the movable core A stopper penetrating portion that protrudes from the end surface of the fixed core side, and when the energization to the coil is stopped, the valve penetrating portion is brought into contact with the valve protruding portion from the side opposite to the fixed core, thereby Projection and engagement Characterized in that it comprises and the movable stopper to form a gap between the movable core, the.

  In such a configuration, a gap is formed between the movable core and the valve protrusion that protrudes from the valve penetrating portion that penetrates the movable core of the valve member in a state in which energization of the coil is stopped. As a result, the movable core moves without a valve member by a gap between the movable core and the valve projection at the start of the valve opening operation for opening the nozzle hole. As a result, when the accelerated movable core collides with the valve protrusion, an impact force corresponding to the momentum at the time of the collision is given to the valve protrusion, so that the valve member for a distance necessary to open the nozzle hole The travel time can be shortened.

  Here, in the movable stopper that locks the movable core in the state where the energization of the coil is stopped, the stopper penetrating portion that penetrates the movable core and protrudes from the fixed core side end surface of the movable core is fixed to the valve protrusion. A gap between the movable core and the valve protrusion is formed by abutting from the opposite side. As described above, the gap size secured by the contact between the two members in the specific operation state can suppress variations caused by the manufacturing state. The impact force applied to the part is less likely to vary. According to this, since the variation rate in the short time as described above can be reduced with respect to the movement time of the valve member, the control accuracy of the fuel injection amount can be increased.

According to the second aspect of the present invention, the movable stopper has a stopper protrusion that protrudes from the stopper penetrating portion and can contact the movable core from the side opposite to the fixed core. According to this, in a state where energization of the coil is stopped, the movable stopper is configured such that the stopper protrusion protruding from the stopper penetration is the movable core from the side opposite to the fixed core, and the stopper penetration is from the opposite side to the valve protrusion. By abutting, a stable size gap can be reliably ensured between the locked movable core and the valve protrusion. Therefore, it is possible to achieve high control accuracy of the fuel injection amount while suppressing the gap size variation.

  According to the third aspect of the present invention, the first elastic member for generating the first restoring force for urging the valve member to the opposite side of the fixed core with respect to the valve housing, and the movable core on the opposite side of the fixed core And a second elastic member for generating a second restoring force for urging the movable stopper toward the fixed core and a third restoring force for urging the movable core toward the fixed core with respect to the valve housing. A movable stopper is provided so as to be movable relative to the fixed core and the opposite side with respect to the valve member.

  In such a configuration, when starting the valve closing operation from the state where the nozzle hole is opened and closing the nozzle hole, the valve member biased to the opposite side to the fixed core by the first restoring force of the first elastic member is The valve protrusion protruding from the valve penetration that penetrates the movable core is brought into contact with the movable core from the fixed core side. At this time, since the magnetic attraction force for moving the movable core toward the fixed core is eliminated by stopping energization of the coil, the movable core that receives the first restoring force of the first elastic member via the valve projection Moves with the valve member to the opposite side of the fixed core. As a result, even when the valve member stops moving by closing the nozzle hole, the second elastic force of the second elastic member urges the movable core to the side opposite to the fixed core and the inertial force acts on the movable core. On the other hand, the stopper protrusion of the movable stopper abuts from the opposite side.

  Thereafter, the movable core and the movable stopper are urged toward the opposite side and the fixed core side by the second restoring force of the second elastic member, respectively, so that the movable core and the stopper protrusion are in contact with each other. Continue moving with inertia. At this time, the stopper penetrating portion of the movable stopper that moves relative to the stationary valve member relative to the stationary valve member is pressed by the movable core on the stationary core side, so that the stopper projection protruding from the movable stopper core is pressed. It will be separated from the protrusion. At the same time, the inertial force (load) that works to continue the movement of the movable core to the opposite side of the fixed core is the third restoring force of the third elastic member that urges the movable core toward the fixed core. It can be attenuated by the action of According to these, the vibration generated when the movable core and the stopper protrusion come into contact with each other is difficult to propagate to the valve protrusion. A situation in which the next injection is caused can be avoided.

  In addition, when opening the nozzle hole by starting the valve opening operation from the state in which the nozzle hole is closed, the movable core first moves without the valve member by receiving the magnetic attraction generated by energizing the coil. . As a result, the movable core that has moved by the gap between the valve protrusion and the valve protrusion of the valve member that receives the first restoring force of the first elastic member and is biased to the opposite side of the fixed core. , It comes in contact from the opposite side. As a result, when the movable core moves toward the fixed core while pressing the valve protrusion and collides with the fixed core, the valve member continues to move against the first restoring force by the inertial force. The valve protrusion moves away from the movable core while the portion moves relative to the movable core. Therefore, even if the movable core bounces away from the fixed core due to the collision reaction force, for the valve member where the bounce force is difficult to propagate to the valve projection, the fuel injection amount varies by closing the nozzle hole accidentally. Can be avoided.

  As described above, according to the invention described in claim 3, the opening and closing of the nozzle hole by the valve member is realized as expected in both the valve opening operation and the valve closing operation, and the fuel injection amount is controlled with high accuracy. To get.

  According to the invention described in claim 4, the second restoring force is larger than the third restoring force in the valve closing operation. According to this, the movable core has a second restoring force of the second elastic member acting toward the side opposite to the fixed core, rather than a third restoring force of the third elastic member acting toward the fixed core side. Since it is large, when the valve member stops moving during the valve closing operation, it is surely brought into contact with the stopper protrusion on the opposite side. Therefore, after this abutment, the stopper projection is pressed by the movable core that continues the inertial movement to the opposite side of the fixed core, and the stopper penetration is separated from the valve projection, thereby vibrating the valve member. Propagation suppression is solid. Therefore, unexpected secondary injection in the valve closing operation can be avoided, and it is possible to contribute to highly accurate injection amount control.

  According to the fourth aspect of the present invention, in the movable core in which the valve member, the movable core, and the movable stopper are stopped by the valve closing operation, the action of the second restoring force of the second elastic member is the third elasticity. It becomes larger than the action of the third restoring force of the member. As a result, the movable core urged toward the acting side of the second restoring force, that is, the side opposite to the fixed core, is fixed on the stopper protrusion of the movable stopper urged toward the fixed core side by the restoring force. Since it can contact | abut from the side and can be latched reliably, the clearance gap between fixed cores is maintained at a fixed distance. Therefore, when the nozzle hole is opened by the valve opening operation after the valve closing operation, the distance by which the movable core is moved to the collision position with the fixed core, and the movement time thereof, can be stabilized by the magnetic attractive force generated by the coil. Therefore, it is possible to contribute to highly accurate injection amount control by suppressing variation in the fuel injection amount due to the valve opening operation.

  According to the fifth aspect of the present invention, the difference between the second restoring force and the third restoring force is suppressed to a set value or less in the valve closing operation. According to this, in a state where the valve member, the movable core, and the movable stopper are stopped by the valve closing operation, the second restoring force of the second elastic member has a difference that is suppressed to a set value or less, and the third elastic member has a difference. It becomes larger than the third restoration power. Therefore, when the nozzle hole is opened by the valve opening operation after the valve closing operation, the movement of the movable core toward the fixed core can be started only by generating a relatively small magnetic attractive force by energizing the coil. . As a result, since the time required from the start of generation of the magnetic attractive force to the start of movement of the valve member by the movable core can be shortened, it is possible to improve the valve opening response.

  According to the invention described in claim 6, the first elastic member for generating the first restoring force for urging the valve member to the opposite side of the fixed core with respect to the valve housing, and the movable core on the opposite side of the fixed core And a second elastic member for generating a second restoring force for urging the movable stopper toward the fixed core, and a third restoring force for urging the movable stopper toward the fixed core with respect to the valve housing. A movable stopper is provided so as to be movable relative to the fixed core and the opposite side with respect to the valve member. With such a configuration, the operation and effects similar to those of the invention described in claim 3 as described above can be realized, but in particular the points described below are different from the invention described in claim 3.

  Here, the difference from the invention according to claim 3 will be described. When the stopper penetrating part is separated from the valve projecting part in the valve closing operation, the stopper projecting part comes into contact with the movable core from the side opposite to the fixed core. The third restoring force of the third elastic member that urges the movable stopper toward the fixed core acts via the stopper protrusion. Therefore, at this time, the inertial force (load) that works to continue the movement of the movable core to the opposite side of the fixed core is attenuated by the action of the third restoring force on the movable core via the stopper protrusion. obtain. Therefore, in the invention described in claim 6 as well, the vibration generated when the movable core and the stopper protrusion come into contact with each other is difficult to propagate to the valve protrusion. By opening the door, it is possible to avoid a situation in which an unexpected secondary injection is caused.

  As described above, according to the invention described in claim 6, the opening and closing of the nozzle hole by the valve member is realized as expected in both the valve opening operation and the valve closing operation, and the fuel injection amount is controlled with high accuracy. To get.

  According to the seventh aspect of the present invention, the movable stopper is disposed between the movable core and the valve protrusion and between the movable core and the stopper protrusion, with the stopper penetrating portion being in contact with the valve protrusion so as to be separable. Among these, a gap is formed in at least one of the fuel injection valves according to the operation. According to this, when the movable stopper having the stopper projection abutted against the movable core in the valve closing operation continues to move to the opposite side of the fixed core by the inertial force, it is only between the movable core and the valve projection. In addition, a gap is also formed between the stopper penetrating portion and the valve protrusion that are separated from each other. After that, when the inertial force is attenuated by the third restoring force of the third elastic member acting toward the fixed core side, the movable core rebounds toward the fixed core side. As a result, the movable stopper urged toward the fixed core by the second restoring force of the second elastic member moves while the stopper protrusion is in contact with the movable core from the side opposite to the fixed core. The stopper penetrating portion is brought into contact with the valve protrusion from the opposite side. At this time, the movable core in a state where a gap is secured between the valve protrusion on the fixed core side makes contact with the valve protrusion that vibrates the valve member due to the presence of the gap. Can be suppressed. Therefore, the movable core that has bounced back to the fixed core abuts against the valve protrusion, thereby avoiding an unexpected secondary injection and contributing to highly accurate injection amount control.

  In the invention according to the seventh aspect, when the second and third restoring forces are set as described in the fourth aspect by adopting the configuration according to the third aspect, the valve member is moved by the valve closing operation. With the core and the movable stopper stopped moving, the second restoring force is greater than the third restoring force. As a result, the movable core can be reliably locked to the stopper protrusion as described above, so that not only the clearance between the movable core and the valve protrusion on the fixed core side can be secured. It will be solid. Therefore, in the valve opening operation after the valve closing operation, the movable core that starts moving toward the fixed core side by the magnetic attraction force generated by the coil first expands the gap between the stopper protrusion and the valve protrusion. After moving without the valve member until it comes into contact with the part, it moves with the valve member and collides with the fixed core. According to such a movement mode, the momentum generated by the movement of the movable core without the valve member can be used for the subsequent movement of the valve member, thereby shortening the movement time of the valve member in the valve opening operation. At the same time, in the invention described in claim 7, by adopting the configuration described in claim 3 and setting the second and third restoring forces as described in claim 4, the movable core collides with the fixed core. The time to move to the position can be stabilized. For these reasons, even when a predetermined amount of fuel is injected in a short time, variations in the injection amount can be suppressed, contributing to highly accurate injection amount control.

  On the other hand, in the invention according to claim 7, when the configuration according to claim 6 is adopted, the second and second movable stoppers receive the valve member, the movable core, and the movable stopper while the valve member, the movable core, and the movable stopper are stopped by the valve closing operation. The stopper protrusion is biased toward the fixed core by the third restoring force. Therefore, the movable core urged to the opposite side of the fixed core by the second restoring force comes into contact with the stopper protrusion urged to the fixed core side as described above from the fixed core side and is securely locked. Can be done. As a result, not only the gap between the movable core and the fixed core, but also the gap between the fixed core and the valve protrusion on the fixed core can be secured. Therefore, in the valve opening operation after the valve closing operation, the movable core that starts moving toward the fixed core side by the magnetic attraction force generated by the coil first expands the gap between the stopper protrusion and the valve protrusion. After moving without the valve member until it comes into contact with the part, it moves with the valve member and collides with the fixed core. According to such a movement mode, the momentum generated by the movement of the movable core without the valve member can be used for the subsequent movement of the valve member, thereby shortening the movement time of the valve member in the valve opening operation. At the same time, in the invention described in claim 7, by adopting the configuration according to claim 6 in which the movable core can be reliably locked to the stopper projection as described above in the movement stop state, the movable core is fixed to the fixed core. It is possible to stabilize the time for moving to the collision position. For these reasons, even when a predetermined amount of fuel is injected in a short time, variations in the injection amount can be suppressed to contribute to highly accurate injection amount control.

  According to the invention described in claim 8, the first elastic member for generating the first restoring force for urging the valve member to the side opposite to the fixed core, the urging the movable core to the side opposite to the fixed core, and And a second elastic member that generates a second restoring force that urges the movable stopper toward the fixed core, and the movable stopper is fixed to the valve member so as to be movable integrally with the fixed core and the opposite side thereof.

  In such a configuration, when starting the valve closing operation from the state where the nozzle hole is opened and closing the nozzle hole, the valve member biased to the opposite side to the fixed core by the first restoring force of the first elastic member is The valve protrusion protruding from the valve penetration that penetrates the movable core is brought into contact with the movable core from the fixed core side. At this time, since the magnetic attraction force for moving the movable core toward the fixed core is eliminated by stopping energization of the coil, the movable core that receives the first restoring force of the first elastic member via the valve projection Moves together with the integral valve member and movable stopper to the opposite side of the fixed core. As a result, even if the valve member and the movable stopper stop moving by closing the nozzle hole, the second elastic member is biased to the opposite side of the fixed core by the second restoring force, and the inertial force acts. The stopper protrusion of the movable stopper abuts against the core from the opposite side. Therefore, the movable core also stops moving while being locked by the stopper projection.

  Thus, when the valve opening operation is started from the state where the nozzle hole is closed and the nozzle hole is opened, the movable core first moves without the valve member by receiving the magnetic attractive force generated by energizing the coil. As a result, the movable core that has moved by the gap between the valve protrusion and the valve protrusion of the valve member that receives the first restoring force of the first elastic member and is biased to the opposite side of the fixed core. , It comes in contact from the opposite side. As a result, when the movable core moves toward the fixed core while pressing the valve protrusion and collides with the fixed core, the valve member continues to move against the first restoring force by the inertial force. The valve protrusion moves away from the movable core while the portion moves relative to the movable core. Therefore, even if the movable core bounces away from the fixed core due to the collision reaction force, the valve member is difficult to propagate to the valve protrusion. Can be avoided.

  As described above, according to the eighth aspect of the present invention, it is possible to control the fuel injection amount with high accuracy by realizing the opening of the injection hole by the valve member as expected, particularly in the valve opening operation. It is.

  According to the invention of claim 9, the movable stopper is between the movable core and the valve projection and between the movable core and the stopper projection, with the stopper penetrating portion in contact with the valve projection. A gap is formed in at least one according to the operation of the fuel injection valve. According to this, even when the movable core that has come into contact with the stopper protrusion due to the valve member and the movable stopper moving and stopped in the valve closing operation bounces back to the fixed core side, the valve protrusion on the fixed core side does not , It is difficult to abut due to the existence of a gap to be secured. Therefore, it is possible to contribute to highly accurate injection amount control by avoiding a situation in which unexpected secondary injection is caused by the movable core coming into contact with the valve protrusion and applying vibration.

  In the invention according to claim 9, the movable core that is urged to the opposite side by the second restoring force when the valve member, the movable core, and the movable stopper are stopped by the valve closing operation. The stopper protrusion that is urged toward the fixed core by the restoring force comes into contact with the fixed core and can be reliably locked. As a result, not only the gap between the movable core and the fixed core, but also the gap between the fixed core and the valve protrusion on the fixed core can be secured. Therefore, in the valve opening operation after the valve closing operation, the movable core that starts moving toward the fixed core side by the magnetic attraction force generated by the coil first expands the gap between the stopper protrusion and the valve protrusion. After moving without the valve member until it comes into contact with the part, it moves with the valve member and collides with the fixed core. According to such a movement mode, the momentum generated by the movement of the movable core without the valve member can be used for the subsequent movement of the valve member, thereby shortening the movement time of the valve member in the valve opening operation. In addition, according to the ninth aspect of the present invention, since the movable core can be reliably locked to the stopper protrusion as described above in the movement stop state, the time for moving the movable core to the collision position with the fixed core can be stabilized. . For these reasons, even when a predetermined amount of fuel is injected in a short time, variations in the injection amount can be suppressed to contribute to highly accurate injection amount control.

  According to the invention described in claim 10, the stopper penetrating portion is formed in a cylindrical shape into which the valve penetrating portion is inserted on the inner peripheral side of the cylindrical movable core. According to this, the cylindrical stopper penetrating portion that penetrates the cylindrical movable core and into which the valve penetrating portion is inserted on the inner peripheral side of the movable core is provided with a valve in the narrowest possible range in the radial direction. It can come into contact with the protrusion. Therefore, since the size in the radial direction can be reduced for the valve protrusion that the movable core abuts on the outer peripheral side of the stopper penetrating portion, the movable core is fixed on the outer peripheral side of the valve protrusion. A large area facing the core can be secured. Therefore, when opening the nozzle hole by opening the valve, the time required from the start of generation to the start of movement of the valve member by the movable core is shortened by generating a magnetic attractive force whose magnitude depends on the facing area of the cores. Therefore, it is possible to improve the valve opening response.

  According to an eleventh aspect of the invention, the movable core has a core main body portion that forms an end surface on the fixed core side so as to be able to contact the valve protrusion, and protrudes from the core main body portion to the opposite side of the fixed core to stop the stopper protrusion. And a core projection that projects from the core receptacle to the inner circumference side, and the second elastic member is accommodated on the inner circumference side of the core receptacle and includes a stopper projection and The coil spring is interposed between the core protrusions. According to such a configuration, the coil spring interposed between the stopper protrusion of the movable stopper and the core protrusion of the movable core has the stopper protrusion and the core protrusion on the fixed core side and the opposite side, respectively. It can function reliably as the second elastic member that urges toward. Therefore, when the nozzle hole is opened by the valve opening operation, the second restoring force of the second elastic member is used to bring the movable core into contact with the stopper projection, that is, between the movable core and the valve projection. The movement of the movable core without the valve member can be started from a state in which a gap of a stable size is secured. Therefore, the movement time of the valve member can be made short and difficult to vary, and the control accuracy of the fuel injection amount can be improved.

  According to a twelfth aspect of the present invention, the movable core has a core main body portion that forms an end face on the fixed core side so as to be able to contact the valve protrusion, and protrudes from the core main body portion to the opposite side of the fixed core to stop the stopper protrusion. The second elastic member includes a disc spring having an outer peripheral portion fixed to the core containing portion and an inner peripheral portion engaging with the stopper protrusion. According to such a configuration, the disc spring having a simple structure in which the inner peripheral portion is engaged with the stopper protrusion of the movable stopper and the outer peripheral portion is fixed to the core receiving portion of the movable core is the stopper protrusion and the core receiving portion. Can function reliably as the second elastic member for urging the fixed core side and the opposite side. Therefore, when the nozzle hole is opened by the valve opening operation, the second restoring force of the second elastic member is used to bring the movable core into contact with the stopper projection, that is, between the movable core and the valve projection. The movement of the movable core without the valve member can be started from a state in which a gap of a stable size is secured. Therefore, the movement time of the valve member can be made short and difficult to vary, and the control accuracy of the fuel injection amount can be improved.

It is sectional drawing which shows schematic structure of the fuel injection valve by 1st embodiment of this invention. It is sectional drawing which shows the modification of FIG. It is sectional drawing which shows the operation state different from FIG. 1 of the fuel injection valve by 1st embodiment of this invention. It is sectional drawing which shows the operation state different from FIG.1, 3 of the fuel injection valve by 1st embodiment of this invention. It is a schematic diagram for demonstrating the restoring force adjustment in the fuel injection valve by 1st embodiment of this invention. It is a schematic diagram for demonstrating the manufacturing method of the fuel injection valve by 1st embodiment of this invention. It is a mimetic diagram for explaining valve opening operation of a fuel injection valve by a first embodiment of the present invention. It is a mimetic diagram for explaining valve closing operation of a fuel injection valve by a first embodiment of the present invention. It is sectional drawing which shows schematic structure of the fuel injection valve by 2nd embodiment of this invention. It is a schematic diagram for demonstrating the restoring force adjustment in the fuel injection valve by 2nd embodiment of this invention. It is sectional drawing which shows the modification of FIG. It is a schematic diagram for demonstrating the valve opening operation | movement of the fuel injection valve by 2nd embodiment of this invention. It is a mimetic diagram for explaining valve closing operation of a fuel injection valve by a second embodiment of the present invention. It is sectional drawing for demonstrating schematic structure of the fuel injection valve by 3rd embodiment of this invention, and explaining the valve opening operation | movement of the said fuel injection valve especially. It is a schematic diagram for demonstrating the restoring force adjustment in the fuel injection valve by 3rd embodiment of this invention. It is sectional drawing for demonstrating the valve closing action | operation of the fuel injection valve by 3rd embodiment of this invention. It is sectional drawing which shows schematic structure of the fuel injection valve by 4th embodiment of this invention. It is a schematic diagram for demonstrating the manufacturing method of the fuel injection valve by 4th embodiment of this invention. It is a schematic diagram for demonstrating the restoring force adjustment in the fuel injection valve by 4th embodiment of this invention. It is a schematic diagram for demonstrating the valve opening operation | movement of the fuel injection valve by 4th embodiment of this invention. It is a schematic diagram for demonstrating the valve closing action | operation 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. In addition, the overlapping description may be abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment. When only a part of the configuration is described in each embodiment, the configuration of the other embodiment described above can be applied to the other part of the configuration. In addition, not only combinations of configurations explicitly described in the description of each embodiment, but also the configurations of a plurality of embodiments can be partially combined even if they are not explicitly specified unless there is a problem with the combination. .

(First embodiment)
FIG. 1 shows a fuel injection valve 10 according to a first embodiment of the present invention. The fuel injection valve 10 is installed in a gasoline engine as an internal combustion engine, and injects fuel into a combustion chamber (not shown) of the gasoline engine. In addition to this application form, for example, the fuel injection valve 10 may inject fuel into an intake passage communicating with a combustion chamber of a gasoline engine, or fuel into a combustion chamber of a diesel engine as an internal combustion engine. May be used.

(Constitution)
Hereinafter, the configuration of the fuel injection valve 10 will be described in detail. The fuel injection valve 10 includes a valve housing 12, a fixed core 20, a movable core 30, a valve member 40, a movable stopper 50, a coil 60, and elastic members 70, 72, and 74.

  The valve housing 12 is formed in a cylindrical shape as a whole, and has a first magnetic part 13, a nonmagnetic part 14, and a second magnetic part 15 in order from one end side in the axial direction toward the other end side. Yes. The magnetic parts 13 and 15 made of magnetism and the nonmagnetic part 14 made of a nonmagnetic material are coupled by laser welding or the like. The non-magnetic portion 14 prevents the magnetic flux from being short-circuited between the first magnetic portion 13 and the second magnetic portion 15 by such a coupling form.

  The first magnetic part 13 is reduced in diameter by one step toward the combustion chamber side opposite to the nonmagnetic part 14, and a bottomed cylindrical nozzle part 16 is formed by the small diameter part 13a on the reduced diameter side. doing. The nozzle portion 16 has a valve seat 18 that surrounds the outer peripheral side of the nozzle hole 17 on the bottom wall portion where the nozzle hole 17 is provided so as to penetrate the central portion in the radial direction in the axial direction. The second magnetic portion 15 forms a fuel inlet 19 at the axial end opposite to the nonmagnetic portion 14. Fuel is supplied to the fuel inlet 19 from a fuel pump (not shown).

  The fixed core 20 is formed in a cylindrical shape by a magnetic material, and is fixed coaxially to the inner peripheral walls of the nonmagnetic portion 14 and the second magnetic portion 15 in the valve housing 12. The fixed core 20 is provided with a receiving hole 21 that penetrates the central portion in the radial direction in the axial direction. A first elastic member 70 is accommodated in the inner peripheral side of the accommodation hole 21 so as to be elastically deformable, and an adjusting pipe 22 for adjusting a set load of the first elastic member 70 is fixed by press-fitting. Yes.

  The movable core 30 is formed in a cylindrical shape as a whole, is coaxially accommodated on the inner peripheral side of the valve housing 12, and is positioned closer to the nozzle portion 16 side (the nozzle hole 17 side) than the fixed core 20. The movable core 30 is guided by the large-diameter portion 13b of the first magnetic portion 13 and the inner peripheral walls of the nonmagnetic portion 14 of the valve housing 12, thereby enabling accurate reciprocation in both axial directions. Yes. Such a movable core 30 comes into contact with the fixed core 20 from the nozzle portion 16 side by axial movement toward the fixed core 20 side.

  Specifically, the movable core 30 is formed of a magnetic material in a cylindrical (thick disc shape) core body portion 31 that faces the fixed core 20 in the axial direction. The core body portion 31 is provided with a core through hole 32 that penetrates the central portion in the radial direction in the axial direction. Here, in the core main body 31, the inner diameter of the core through hole 32 is set smaller than the inner diameter of the accommodation hole 21 provided in the fixed core 20 facing the movable core 30 in the axial direction. Further, the outer diameter of the core body 31 is set to be slightly smaller than the inner diameters of the large-diameter portion 13 b of the first magnetic portion 13 and the non-magnetic portion 14 of the valve housing 12. With this setting, the core body 31 can be guided by the valve housing 12 and can be opposed to and contact the axial end surface 31 a with respect to the fixed core 20.

  Furthermore, the movable core 30 has a cylindrical core housing portion 33 that is coaxially projected from the core body portion 31 to the opposite side of the fixed core 20 in a cylindrical shape. A second elastic member 72 is accommodated on the inner peripheral side of the core accommodating portion 33 so as to be elastically deformable, and a stopper protrusion 54 of a movable stopper 50 described later in detail is accommodated so as to be relatively movable. Here, by setting the inner diameter of the core accommodating portion 33 to be larger than the inner diameter of the through hole 32, the axial end surface 31 b on the opposite side of the fixed core 20 in the core body portion 31 is the inner circumference of the accommodating portion 33. The stopper protrusion 54 can be contacted on the side. Further, the outer diameter of the core housing portion 33 is set to be smaller than the outer diameter of the core main body portion 31, so that the first magnetic portion 13 has a large diameter portion 13 b and the core housing portion 33 in the radial direction. Three elastic members 74 are accommodated so as to be elastically deformable. In the present embodiment, the core housing portion 33 is formed integrally with the core main body portion 31 with a magnetic material. For example, the core housing portion 33 formed separately from the core main body portion 31 is welded to the main body portion 31. It may be joined by, for example.

  Furthermore, the movable core 30 has a core protrusion 34 that protrudes inward from the axial end opposite to the core body 31 in the core housing portion 33 in a circular bowl shape coaxial with the other portions 31 and 33. Forming. Here, the inner diameter of the core protrusion 34 is set larger than the inner diameter of the core through hole 32. In this embodiment, the core protrusion 34 made of a non-magnetic material is joined to a core housing portion 33 formed separately from the core housing portion 33 by welding or the like. For example, the axial direction of the core housing portion 33 made of a magnetic material It may be formed by bending the end portion toward the inner periphery as shown in FIG.

  As shown in FIG. 1, the valve member 40 is formed of a non-magnetic material in the shape of a needle having a circular cross section as a whole, and is accommodated coaxially on the inner peripheral side of the valve housing 12. The valve member 40 opens and closes the injection hole 17 by reciprocating movement in both axial directions, thereby intermittently injecting fuel from the injection hole 17 to the combustion chamber.

  Specifically, the valve member 40 has a conical sheet portion 41 that gradually decreases in diameter toward the nozzle portion 16 side at an end portion in the axial direction on the nozzle portion 16 side. As shown in FIG. 1, the seat portion 41 closes the nozzle hole 17 and shuts off fuel injection by a valve closing operation in which a conical tip is inserted into the nozzle hole 17 and a conical circumferential surface is seated on the valve seat 18. On the other hand, as shown in FIG. 3, the seat portion 41 opens the nozzle hole 17 by the valve opening operation of extracting the conical tip from the nozzle hole 17 and separating the conical circumferential surface from the valve seat 18 to thereby generate fuel. Allow injection.

  Further, as shown in FIG. 1, the valve member 40 has a cylindrical valve penetration portion 42 that extends straight in the axial direction from the seat portion 41 toward the fixed core 20 side as a main body portion of the valve member 40. ing. Here, by setting the outer diameter of the valve penetrating portion 42 to be smaller than the inner diameter of the core through-hole 32 that is the smallest among the inner diameters of the movable core 30, the valve penetrating portion 42 corresponds to each portion 31 of the movable core 30. , 33 and 34 are penetrated in the axial direction so as to be relatively movable. Further, by setting the outer diameter of the valve penetrating portion 42 to be smaller than the inner diameter of the nozzle portion 16 composed of the small diameter portion 13 a in the first magnetic portion 13, a fuel passage 48 is formed between the elements 16 and 42. Yes. The fuel passage 48 thus formed communicates with the injection hole 17 by the valve opening operation in which the seat portion 41 is separated from the valve seat 18 as shown in FIG. 3, while the seat portion 41 communicates with the valve seat 18 as shown in FIG. 1. The communication with the nozzle hole 17 is interrupted by the valve closing operation to be seated.

  Furthermore, the valve member 40 has a circular hook-shaped valve protrusion 44 protruding from the valve penetrating part 42 to the outer peripheral side at the axial end on the fixed core 20 side. Here, by setting the outer diameter of the valve projection 44 to be larger than the inner diameter of the through-hole 32, the core main body 31 forms the axial end surface 44 a of the valve projection 44 that makes a boundary with the valve penetration 42. It can contact | abut from the fixed core 20 side to the axial direction end surface 31a to do. Further, since the outer diameter of the valve protrusion 44 is slightly smaller than the inner diameter of the accommodation hole 21, the valve protrusion 44 is slidably inserted into the accommodation hole 21. With this insertion structure, in this embodiment, the valve protrusion 44 is guided by the inner peripheral wall of the accommodation hole 21 in the fixed core 20, so that the valve member 40 can be accurately reciprocated in both axial directions. Yes.

  In addition, a fuel hole 46 is provided in the valve member 40 across the valve protrusion 44 and the valve penetration part 42. The fuel hole 46 opens to the axial end surface 44b on the opposite side of the core main body 31 in the valve protrusion 44, so that the fuel hole 46 passes through the accommodation hole 21 into which the protrusion 44 is inserted and the inner peripheral side of the adjusting pipe 22. The fuel inlet 19 is always in communication. At the same time, the fuel hole 46 opens to the peripheral surface of the valve penetrating portion 42, so that the fuel hole 46 is always in the fuel passage 48 between the nozzle portion 16 and the valve penetrating portion 42 through the inner peripheral side of the core accommodating portion 33 and the core protruding portion 34. Communicate. Therefore, in the present embodiment, the fuel supplied to the fuel inlet 19 is a fuel that can communicate with the nozzle hole 17 via the accommodation hole 21, the fuel hole 46, the core accommodation part 33, and the inner peripheral side of the core protrusion 34 in order. It reaches the passage 48.

  The movable stopper 50 is formed of a nonmagnetic material in a cylindrical shape as a whole, and is accommodated coaxially on the inner peripheral side of the valve housing 12. Between the movable core 30 and the valve member 40 in the radial direction, the movable stopper 50 is interposed so as to be able to reciprocate in both axial directions.

  Specifically, the movable stopper 50 has a stopper penetrating portion 52 formed in a cylindrical shape extending straight in the axial direction. Here, since the outer diameter of the stopper through-hole 52 is set slightly smaller than the inner diameter of the core through-hole 32, the stopper through-hole 52 is inserted into the core through-hole 32 so as to be slidable relative to the core main body portion. The radial center part of 31 is penetrated in the axial direction. Further, since the inner diameter of the stopper penetrating portion 52 is set slightly larger than the outer diameter of the valve penetrating portion 42, the valve penetrating portion 42 is relatively slipped on the stopper penetrating portion 52 on the inner peripheral side of the core body portion 31. It is inserted freely. In this embodiment, the stopper penetrating portion 52 is guided along the inner peripheral wall of the core through hole 32 and the outer peripheral wall of the valve penetrating portion 42 by these insertion structures, so that the movable stopper 50 can be accurately positioned on both sides in the axial direction. Reciprocal movement is possible. Such a stopper penetrating portion 52 is axially moved from the side opposite to the fixed core 20 to the axial direction of the projecting portion 44 by the axial movement toward the valve projecting portion 44 formed to have a larger diameter than the core through hole 32. It contacts the end surface 44a.

  Further, the movable stopper 50 has a stopper protrusion 54 that protrudes from the axial end opposite to the valve protrusion 44 in the stopper penetrating part 52 to the outer peripheral side in a circular bowl shape coaxial with the penetrating part 52. Yes. Here, the outer diameter of the stopper projection 54 is set to be larger than the inner diameter of the core through-hole 32 and smaller than the inner diameter of the core housing portion 33. With this setting, the stopper projection 54 can abut the axial end surface 54a of the stopper projection 54 that forms a boundary with the stopper penetration 52, and the axial end surface 31b of the core body 31 from the opposite side to the fixed core 20. It has become. In this embodiment, the stopper protrusion 54 is formed integrally with the stopper penetration 52 by a nonmagnetic material. For example, the stopper protrusion 54 formed separately from the stopper penetration 52 is formed in the penetration 52. It may be joined by welding or the like.

  In addition, the movable stopper 50 is formed between the core body 31 and the valve protrusion 44 and between the core body 31 and the stopper, with the stopper penetrating portion 52 in contact with the valve protrusion 44 so as to be separable as shown in FIGS. A gap 56 is formed in at least one of the protrusions 54 according to the operation of the fuel injection valve 10. Therefore, when the stopper projection 54 is in contact with the movable core 30 and the stopper penetration 52 is separated from the valve projection 44 to form a gap 58 as shown in FIG. 4, the gap between the core body 31 and the stopper projection 54 is formed. While the gap 56 disappears, the gap 56 between the core body 31 and the valve protrusion 44 is enlarged. In the following, the gap 56 formed between the core main body 31 and the valve protrusion 44 as shown in FIGS. 1 and 4 will be referred to as a valve protrusion side gap 56a. The gap 56 formed between the stopper protrusions 54 is particularly referred to as a stopper protrusion-side gap 56b.

  A coil 60 shown in FIG. 1 is wound around a bobbin (not shown) and covered with a magnetic yoke 62. The coil 60 is coaxially fixed to the outer peripheral walls of the nonmagnetic part 14 and the second magnetic part 15 on the outer peripheral side of the fixed core 20 in the valve housing 12. The coil 60 is electrically connected to an external control circuit (not shown) and is energized and controlled by the control circuit. Here, when the coil 60 is excited by energization, the magnetic yoke 62, the first magnetic portion 13, the core body portion 31 of the movable core 30, the fixed core 20 and the second magnetic portion 15 are jointly formed. Magnetic flux flows. As a result, a magnetic attractive force that attracts and moves the movable core 30 toward the fixed core 20 is generated between the core main body 31 and the fixed core 20 facing each other. On the other hand, when the coil 60 is demagnetized by stopping energization, magnetic flux does not flow in the magnetic circuit, so that the magnetic attractive force disappears between the core body 31 and the fixed core 20.

  The first elastic member 70 is made of a metal compression coil spring and is accommodated coaxially on the inner peripheral side of the accommodation hole 21. One end of the first elastic member 70 is locked to the adjusting pipe 22, and the other end of the elastic member 70 is locked to the valve protrusion 44. With this locking structure, the first elastic member 70 is interposed between the fixed core 20 to which the adjusting pipe 22 is fixed and the valve member 40 having the valve protrusion 44. It is compressed in between and elastically deforms. Therefore, the first restoring force F <b> 1 (see FIG. 5) generated by the elastic deformation of the first elastic member 70 becomes a biasing force that biases the valve member 40 toward the opposite side of the fixed core 20 with respect to the valve housing 12. .

  The second elastic member 72 is made of a metal compression coil spring and is accommodated coaxially on the inner peripheral side of the core accommodating portion 33. One end of the second elastic member 72 is locked to the core protrusion 34, and the other end of the second elastic member 72 is locked to the stopper protrusion 54 closer to the fixed core 20 than the core protrusion 34. . With this locking structure, the second elastic member 72 is interposed between the movable core 30 having the core protrusion 34 and the movable stopper 50 having the stopper protrusion 54. Compressed and elastically deformed. Accordingly, the second restoring force F2 (see FIG. 5) generated by the elastic deformation of the second elastic member 72 urges the movable core 30 to the side opposite to the fixed core 20 and simultaneously moves the movable stopper 50 to the fixed core 20 side. It becomes the urging force that urges to.

  The third elastic member 74 is made of a metal compression coil spring and is coaxially accommodated on the inner peripheral side of the large diameter portion 13 b of the first magnetic portion 13 and on the outer peripheral side of the core accommodating portion 33. One end portion of the third elastic member 74 is locked to the step portion 13c that connects the small diameter portion 13a and the large diameter portion 13b in the first magnetic portion 13, and the other end portion of the third elastic member 74 is the step portion 13c. It is locked to the core body 31 on the fixed core 20 side. With this locking structure, the third elastic member 74 is interposed between the valve housing 12 having the step portion 13 c and the movable core 30 having the core body portion 31. It is compressed and elastically deformed. Therefore, the third restoring force F3 (see FIG. 5) generated by the elastic deformation of the third elastic member 74 serves as a biasing force that biases the movable core 30 toward the fixed core 20 with respect to the valve housing 12.

(Restoration adjustment)
FIG. 1 shows a state in which the movable elements 30, 40, and 50 all stop moving and the injection hole 17 is closed (hereinafter simply referred to as “valve-closed state”). Is shown. In this valve-closed state, the seat portion 41 is seated on the valve seat 18, and the stopper penetrating portion 52 and the stopper protruding portion 54 abut against the valve protruding portion 44 and the core main body portion 31, respectively. The relationship between the restoring forces F1, F2, and F3 of the elastic members 70, 72, and 74 is adjusted so that only the gap 56a is formed.

  Therefore, hereinafter, adjustment of the restoring forces F1, F2, and F3 of the elastic members 70, 72, and 74 in the valve-closed state will be described with reference to FIG. In FIG. 5, symbol Fvs indicates the force acting between the valve member 40 and the movable stopper 50, symbol Fcs indicates the force acting between the movable core 30 and the movable stopper 50, and symbol Fvh. Indicates the force acting between the valve member 40 and the valve housing 12.

As apparent from FIG. 5, the force balance relation in the valve member 40 is expressed by the following (formula 1), the force balance relation in the movable stopper 50 is expressed by the following (formula 2), and the force balance in the movable core 30 is The balance relationship is expressed by the following (formula 3).
+ F1-Fvs-Fvh = 0 (Formula 1)
−F2 + Fvs + Fcs = 0 (Expression 2)
-F3 + F2-Fcs = 0 (Formula 3)

When these (Equation 1), (Equation 2), and (Equation 3) are arranged and solved for each force Fvs, Fcs, and Fvh, the following (Equation 4), (Equation 5), and (Equation 6) are respectively obtained. can get.
Fvs = F3 (Formula 4)
Fcs = F2-F3 (Formula 5)
Fvh = F1-F3 (Formula 6)

In the closed state of the fuel injection valve 10, the magnitudes of the forces Fvs, Fcs, and Fvh need to be larger than 0. Therefore, the right side of (Expression 4)> 0, the right side of (Expression 5)> 0, and the relationship of the right side of (Expression 6)> 0 holds. Therefore, the following (Expression 7), (Expression 8), and (Expression 9) are obtained.
F3> 0 (Expression 7)
F2> F3 (Formula 8)
F1> F3 (Formula 9)

Here, with regard to (Equation 7), (Equation 8), and (Equation 9), particularly in this embodiment, the movable elements 30, 40, and 50 are always established in the valve closing operation including the closed state in which the movable elements 30, 40, and 50 are completely stopped. The restoring forces F1, F2, and F3 are adjusted. Further, in the present embodiment, in relation to (Equation 8) indicating that the second restoring force F2 is larger than the third restoring force F3, the following (Equation 10) is established, that is, the restoring forces F2, F3. The adjustment is performed so that the difference between the two is suppressed to be equal to or less than the set value δF. The set value δF is a value set in advance so that a desired valve opening response can be obtained according to the principle described in detail later.
F2-F3 ≦ δF (Formula 10)

(Production method)
Hereinafter, the manufacturing method of the fuel injection valve 10 will be described in detail.

  First, as shown in FIG. 6A, the movable stopper 50 and the second elastic member 72 are assembled to the movable core 30 in which the core protrusion 34 is not joined to the core housing portion 33. Thereby, the stopper penetrating portion 52 is inserted into the through hole 32 of the core body portion 31, and the stopper protrusion 54 and the second elastic member 72 are accommodated in the core accommodating portion 33, and then, as shown in FIG. As shown, the core protrusion 34 is joined to the core housing portion 33 to adjust the set load of the second elastic member 72.

  As shown in FIG. 6C, an integrated body of the elements 30, 50, 72 formed by bringing the stopper protrusion 54 into contact with the core body 31 by joining the core protrusion 34 is the valve housing 12 (in this embodiment). The small fuel inlet 19 is removed, and the third elastic member 74 is inserted. As a result, after the third elastic member 74 is interposed between the integrated body of the elements 30, 50, 72 and the valve housing 12, the valve penetrating portion 42 of the valve member 40 is moved as shown in FIG. It inserts in the stopper penetration part 52, the core accommodating part 33, and the core protrusion 34 sequentially. At this time, particularly in this embodiment, the stopper penetrating portion 52 is brought into contact with the valve protrusion 44.

  Then, as shown in FIG. 6 (e), the fixed core 20 is press-fitted into the valve housing 12 and fixed, and the first elastic member 70 and the adjusting pipe 22 are inserted into the accommodation hole 21 of the fixed core 20. Then, the set load of the first and third elastic members 70 and 74 is determined. At this time, particularly in the present embodiment, the valve protrusion side gap 56 a is appropriately secured between the valve protrusion 44 and the core body 31. After the above, the fuel injection valve 10 is completed by fixing the coil 60 to the outer peripheral wall of the valve housing 12 or the like.

(Operation)
Hereinafter, the operation of the fuel injection valve 10 will be described in detail.

(Valve opening operation)
First, the opening operation of the fuel injection valve 10 will be described. When energization of the coil 60 is started in the valve-closed state shown in FIG. 7A, the magnetic attractive force acts on the core body 31, so that the movable core 30 becomes the second restoring force F <b> 2 of the second elastic member 72. The movement toward the fixed core 20 resisted is started. Here, in the energization stop state immediately before (that is, the valve-closed state in FIG. 7A), the valve penetrating portion 52 protrudes from and comes into contact with the end surface 31a of the core body portion 31 on the fixed core 20 side. A valve protrusion side clearance 56 a is secured between the main body portion 31 and the core main body portion 31 locked to the stopper protrusion 54. Therefore, at the start of energization, the movable core 30 first moves to the fixed core 20 side without the valve member 40 by the valve protrusion side gap 56a.

  Thereafter, the movable core 30 that continues to move toward the fixed core 20 by energization of the coil 60 is directed from the first elastic member 70 to the side opposite to the fixed core 20 as shown in FIG. The core body 31 is brought into contact with the valve protrusion 44 that receives the first restoring force F1 from the opposite side. Then, the movable core 30 moves to the fixed core 20 side together with the valve member 40 while pressing the valve protrusion 44 by the core main body 31 against the first restoring force F1. As a result, the seat portion 41 moves away from the valve seat 18 (see the vicinity of the nozzle portion 16 in FIG. 7C), and the fuel in the fuel passage 48 is injected from the opened nozzle hole 17. At this time, the movable stopper 50 moves with the valve member 40 while the stopper stopper 52 is brought into contact with the valve protrusion 44 by the second restoring force F2 of the second elastic member 72, so that the gap on the stopper protrusion side 56 b is formed between the stopper projection 54 and the core main body 31 in the maximum size.

  Thus, when the movement of the movable core 30 according to the energization of the coil 60 is continued, the core body 31 collides with the fixed core 20 as shown in FIG. Then, as shown in FIG. 7 (d), the valve member 40 continues to move due to the inertial force, so that the valve penetrating portion 42 followed by the stopper penetrating portion 52 by the second restoring force F <b> 2 is moved relative to the core body portion 31. The valve protrusion 44 is separated from the core body 31 while being relatively moved. Therefore, even if the movable core 30 bounces away from the fixed core 20 due to the collision reaction force, the bounce force of the valve member 40 that is difficult to propagate to the valve projection 44 is closed by mistake. Thus, it is possible to avoid a situation that causes variations in the fuel injection amount. Therefore, it is possible to contribute to highly accurate injection amount control.

  In this way, in the first embodiment, after the movable core 30 is moved without the valve member 40, the movable elements 40, 30 are moved integrally, and this is caused by the movement of the previous movable core 30. The movement amount of the valve member 40 can be shortened by using the obtained momentum for the subsequent movement of the valve member 40. Furthermore, in the first embodiment, since the above (Equation 8) is established in the valve-closed state of FIG. 7A, the second restoring force F2 of the second elastic member 72 and the third Of the third restoring force F3 of the elastic member 74, the former is biased in the direction of action. That is, the movable core 30 that is biased toward the side opposite to the fixed core 20 contacts the stopper protrusion 54 that is biased toward the fixed core 20 by the second restoring force F2 from the fixed core 20 side. In contact, it can be securely locked. As a result, the valve protrusion side gap 56a between the core main body 31 and the valve protrusion 44 is secured to a stable size in which variation caused by the manufacturing state is suppressed. Thus, the variation rate in such a short time is reduced and stabilized. Further, since the core body 31 is securely locked to the stopper projection 54, the core body 31 that keeps the facing distance between the cores 30 and 20 constant from the start of the valve opening operation collides with the fixed core 20. The travel time until it stabilizes. For these reasons, for example, even when a predetermined amount of fuel is injected in a short time in order to atomize the injected fuel, the variation in the injection amount is suppressed, contributing to highly accurate injection amount control. Can do it.

  In addition, in the first embodiment, since the above (Equation 10) is also established in the valve-closed state shown in FIG. 7A, even if a relatively small magnetic attractive force is generated by the coil 60, The movement of the movable core 30 against the restoring force F2 to the fixed core 20 side can be started. According to this, since the time required from the start of the valve opening operation to the start of movement of the valve member 40 can be shortened, the valve opening response can be improved.

  Moreover, in the first embodiment, the stopper penetrating portion 52 is a cylindrical shape that penetrates the cylindrical core main body portion 31 and into which the valve penetrating portion 42 is inserted on the inner peripheral side of the main body portion 31. The valve protrusion 44 can be brought into contact with the narrowest possible range. Therefore, as shown in FIG. 7B, the outer diameter of the valve protrusion 44 with which the core main body 31 abuts on the outer peripheral side of the stopper penetrating portion 52 is reduced, and the opposing areas of the cores 20 and 30 on the outer peripheral side are reduced. As a result, the magnetic attractive force according to the facing area can be increased. This also shortens the time required from the start of the valve opening operation to the start of movement of the valve member 40, thereby improving the valve opening response.

(Valve closing operation)
Next, the valve closing operation of the fuel injection valve 10 will be described. As shown in FIG. 8A, when the energization to the coil 60 is stopped after each movable element 30, 40, 50 stops moving in the fuel injection state from the injection hole 17 by the previous valve opening operation, The magnetic attractive force acting on the main body 31 disappears. At this time, the valve member 40 makes the valve protrusion 44 contact the core body 31 and the stopper penetration 52 from the fixed core 20 side. Therefore, the movable core 30 moves from the first elastic member 70 to the opposite side to the fixed core 20 while the core body 31 is pressed by the valve protrusion 44 that receives the first restoring force F1 from the first elastic member 70 to the opposite side to the fixed core 20. Is started together with the other movable elements 40 and 50 against the third restoring force F3 of the third elastic member 74.

  As a result, when the seat portion 41 is seated on the valve seat 18 (see the vicinity of the nozzle portion 16 in FIG. 8B), the movement of the valve member 40 is stopped, the injection hole 17 is closed, and fuel injection is also stopped. At this time, the movable core 30 having a stopper protrusion side gap 56b between the core body 31 and the stopper protrusion 54 is larger than the third restoring force F3 facing the fixed core 20 and facing the opposite side. The second restoring force F <b> 2 of the second elastic member 72 acting as described above acts together with the inertial force. Therefore, the movable core 30 continues to move to the opposite side to the fixed core 20 while relatively moving with respect to the through portions 42 and 52 as shown in FIG. Then, as shown in FIGS. 8B and 8C, the movable core 30 causes the core main body 31 to move away from the valve protrusion 44 and to contact with the stopper protrusion 54. A valve protrusion side gap 56 a is formed between the valve protrusion 31 and the valve protrusion 44.

  Thereafter, the movable core 30 and the movable stopper 50 in which the second elastic member 72 is interposed between the protrusions 34 and 54 are urged to the opposite sides by the second restoring force F2 of the elastic member 72, respectively. Thus, the movement is continued by inertia while the core body 31 and the stopper projection 54 are kept in contact with each other. Here, as shown in FIG. 8C, the stopper penetrating portion 52 that protrudes from the end surface 31a of the core main body 31 and contacts the valve protruding portion 44 has the stopper protruding portion 54 as shown in FIG. By being pressed by the core body 31 on the 20th side, it moves relative to the valve penetration part 42 and is separated from the valve protrusion 44. At the same time, the inertial force (load) acting so as to continue the movement of the movable core 30 to the side opposite to the fixed core 20 is directed from the third elastic member 74 toward the fixed core 20. It can be attenuated by the third restoring force F3 acting on According to these, the vibration generated by the contact between the core main body 31 and the stopper protrusion 54 is difficult to propagate to the valve protrusion 44. Therefore, the valve member 40 mistakenly causes the nozzle hole 17 due to such vibration. The situation of opening and incurring an unexpected secondary injection can be avoided. Therefore, it is possible to contribute to highly accurate injection amount control.

  Further, according to the movable movement of the movable core 30 and the movable stopper 50 in this way, as shown in FIG. 8D, not only the valve protrusion side gap 56a between the core main body 31 and the valve protrusion 44, A gap 58 between the stopper penetrating portion 52 and the valve protrusion 44 that are spaced apart from each other is also formed. After that, when the inertial force is attenuated by the third restoring force F3 acting from the third elastic member 74 toward the fixed core 20 side, the movable core 30 rebounds toward the core 20 side. As a result, the movable stopper 50 urged toward the fixed core 20 by the second restoring force F2 of the second elastic member 72 moves to the fixed core 20 side, and as shown in FIG. The stopper penetration 52 is brought into contact with the valve protrusion 44. At this time, the core main body 31 in which the valve protrusion side gap 56a is formed between the fixed core 20 and the valve protrusion 44 is moved away from the stopper protrusion 54 as shown in FIG. Even if it continues, contact | abutting to the valve protrusion 44 which gives a vibration to the valve member 40 can be suppressed by presence of the said clearance gap 56a. Therefore, the unexpected secondary injection resulting from the contact between the movable core 30 bounced back to the fixed core 20 and the valve member 40 can be avoided, thereby contributing to highly accurate injection amount control.

  After the above, in the first embodiment, as shown in FIG. 8 (f), all of the movable elements 30, 40, 50 stop moving and close the nozzle hole 17 (that is, FIG. In the same state as), the next valve opening operation corresponding to energization of the coil 60 is awaited.

(Second embodiment)
As shown in FIG. 9, the second embodiment of the present invention is a modification of the first embodiment. In the fuel injection valve 210 of the second embodiment, the movable core 230 that is not provided with the core protrusion 34 described in the first embodiment is adopted, and modifications corresponding thereto are added to the first embodiment. Yes.

  Specifically, in the movable core 230 having a cylindrical shape as a whole, the outer diameter of the core housing portion 233 protruding from the core main body portion 31 to the side opposite to the fixed core 20 is substantially equal to the outer diameter of the core main body portion 31. The same diameter is set. In addition, the second elastic member 272 is fixed to the axial end surface 233 a on the opposite side of the fixed core 20 in the core housing portion 233.

  Here, with respect to the second elastic member 272 of the second embodiment made of a metal disc spring, the outer peripheral portion 272a forming one end portion thereof is coaxial with the end surface 233a of the core housing portion 233 made of a magnetic material by welding or the like. It is fixed on the top. At the same time, the inner peripheral portion 272b forming the other end portion of the second elastic member 272 is accommodated together with the stopper protrusion 54 on the inner peripheral side of the core accommodating portion 233 that is recessed toward the fixed core 20 from the end surface 233a. The protrusion 54 is engaged with an axial end surface 254b opposite to the fixed core. With such a configuration, the second elastic member 272 is compressed and elastically deformed by reducing the axial distance between the end surface 233a of the core housing portion 233 and the end surface 254b of the stopper projection 54. Accordingly, the second restoring force F2 (see FIG. 10) generated by the elastic deformation of the second elastic member 272 urges the movable core 230 to the side opposite to the fixed core 20 and simultaneously moves the movable stopper 50 to the fixed core 20 side. It becomes the urging force that urges to.

  Further, as the third elastic member 274 of the second embodiment, a metal compression coil spring similar to that of the first embodiment is employed, but the first of the end surface 233a of the core housing portion 233 and the valve housing 12 is used. Between the step part 13c of the magnetic part 13, it is accommodated coaxially. With respect to the third elastic member 274, the end opposite to the locking side by the step portion 13 c is locked to the end surface 233 a of the core housing portion 233 via the outer peripheral portion 272 a of the second elastic member 272. . With this locking structure, the third elastic member 274 is interposed between the valve housing 12 having the stepped portion 13 c and the movable core 230 having the core housing portion 233. It is compressed and elastically deformed. Therefore, the third restoring force F3 (see FIG. 10) generated by the elastic deformation of the third elastic member 274 is an urging force that urges the movable core 230 toward the fixed core 20 with respect to the valve housing 12.

  Also in such a fuel injection valve 210, the forces Fvs, Fcs, and Fvh as shown in FIG. 10 (where the force Fcs is a force acting between the movable elements 230 and 50) are assumed in accordance with the first embodiment. Thus, the restoring forces F1, F2, and F3 of the respective elastic members 70, 272, and 274 in the valve-closed state are adjusted according to (Expression 7) to (Expression 10) described in the first embodiment. As shown in FIG. 11, the end of the third elastic member 274 opposite to the locking side by the stepped portion 13 c may be directly locked to the end surface 233 a of the core housing portion 233. In this case, the restoring forces F1, F2, and F3 can be adjusted according to (Expression 7) to (Expression 10).

(Valve opening operation)
Hereinafter, the valve opening operation among the operations of the fuel injection valve 210 will be described in detail. When energization of the coil 60 is started in the valve-closed state shown in FIG. 12A, the magnetic attractive force acts on the core main body 31, so that the movable core 230 becomes the second restoring force F <b> 2 of the second elastic member 272. The movement toward the fixed core 20 resisted is started. Here, in the energization stop state immediately before (that is, the valve closed state in FIG. 12A), the stopper penetrating portion 52 of the core main body portion 31 locked to the stopper protrusion 54 is the same as in the first embodiment. It protrudes from the end surface 31 a on the fixed core 20 side and is in contact with the valve protrusion 44. Since the valve protrusion side clearance 56a is ensured between the valve protrusion 44 and the core body 31 by such contact, the movable core 230 firstly has a valve member corresponding to the clearance 56a at the start of energization. It moves to the fixed core 20 side without accompanying 40.

  Thereafter, the movable core 230 that continues to move toward the fixed core 20 by energizing the coil 60 receives the first restoring force F1 of the first elastic member 70 as shown in FIG. 44, the core body 31 is brought into contact with the fixed core 20 from the opposite side. Then, the movable core 230 moves to the fixed core 20 side together with the valve member 40 while pressing the valve protrusion 44 against the first restoring force F1 by the core main body portion 31, so that the seat portion 41 is moved to the valve seat 18. The fuel is injected from the nozzle hole 17 while being separated from the nozzle hole 17. At this time, the movable stopper 50 moves together with the valve member 40 while bringing the stopper penetrating portion 52 into contact with the valve protrusion 44 by the second restoring force F2 of the second elastic member 272. As a result, the stopper protrusion side gap 56b is formed between the stopper protrusion 54 and the core body 31 in the maximum size in a state where the disc spring forming the second elastic member 272 is elastically deformed.

  When the movement of the movable core 230 is continued in this way, the core body 31 collides with the fixed core 20 as shown in FIG. 12C, and the valve member 40 continues the inertial movement as shown in FIG. As a result, the valve penetrating part 42 that the stopper penetrating part 52 follows moves relative to the core body part 31, and the valve protrusion 44 is separated from the core body part 31. Therefore, even if the movable core 230 is bounced back by receiving a collision reaction force from the fixed core 20, the bounce force 17 is erroneously closed with respect to the valve member 40 that is difficult to propagate to the valve protrusion 44. Thus, a situation in which the fuel injection amount varies can be avoided.

  As described above, in the second embodiment, the movable core 230 is accelerated by the movement not accompanied by the valve member 40 and collides with the valve protrusion 44 in the same manner as in the first embodiment. Therefore, according to the momentum at the time of the collision. The applied impact force can be applied to the valve projection 44 to move the valve member 40 quickly. Therefore, the movement time of the valve member 40 for the distance necessary to open the nozzle hole 17 can be shortened. Further, in the second embodiment, since (Equation 8) is established in the valve-closed state of FIG. 12A, the former action of the restoring forces F2 and F3 with respect to the movable core 230 becomes dominant, and the core The main body 31 can be securely locked to the stopper projection 54. As a result, a gap 56a having a stable size is secured to stabilize the movement time of the valve member 40, and the gap between the cores 230 and 20 is maintained at a constant distance, so that the movement time of the movable core 230 is stabilized. . Therefore, for example, even when fuel is injected in a short time and the minimum injection amount is reduced to atomize the injected fuel, variation in the minimum injection amount is suppressed and high accuracy is achieved. It is possible to contribute to proper injection amount control.

  In addition, in the second embodiment, since (Equation 10) is established in the valve-closed state of FIG. 12A, the movement of the valve member 40 starts from the start of the valve opening operation according to the same principle as in the first embodiment. It is possible to shorten the time required to increase the valve opening response. At the same time, in the second embodiment, similarly to the first embodiment, the stopper penetrating portion 52 can be brought into contact with the valve protrusion 44 in the narrowest possible range in the radial direction. The time required from the start of the valve operation to the start of the movement of the valve member 40 can be shortened to improve the valve opening response.

(Valve closing operation)
Next, the valve closing operation among the operations of the fuel injection valve 210 will be described in detail. As shown in FIG. 13 (a), after the movable elements 230, 40, 50 stop moving due to the previous valve opening operation, when the energization to the coil 60 is stopped, the valve protrusion 44 is moved from the fixed core 20 side to the element. The magnetic attractive force acting on the core main body 31 disappears in the state where it abuts against the cores 31 and 52. Then, the movable core 230 resists the third restoring force F3 of the third elastic member 274 while being pressed to the opposite side of the fixed core 20 by the valve protrusion 44 that receives the first restoring force F1 of the first elastic member 70. The movement to the opposite side is started together with the other movable elements 40 and 50.

  As a result, the seat portion 41 is seated on the valve seat 18 and the movement of the valve member 40 and the fuel injection are stopped.At this time, the movable core 230 having a gap 56b between the stopper projection 54 and The second restoring force F2 of the second elastic member 272 that is greater than the opposite third restoring force F3 acts together with the inertial force. As a result, the movable core 230 continues to move to the opposite side of the fixed core 20 while moving relative to the through portions 42 and 52 as shown in FIG. Then, as shown in FIGS. 13B and 13C, the movable core 230 causes the core main body 31 to be separated from the valve protrusion 44, and further causes the core main body 31 to contact the stopper protrusion 54. Thus, the valve protrusion side gap 56 a is formed between the valve protrusion 44 and the valve protrusion 44.

  Thereafter, the movable core 230 and the movable stopper 50 are urged to the opposite sides by the second restoring force F2 of the second elastic member 272, respectively, so that the core body 31 and the stopper projection 54 are kept in contact with each other. Undershoot by continuing inertial movement. At this time, since the stopper protrusion 54 is pressed by the core body 31 as shown in FIG. 13D, the protrusion from the end surface 31a of the core body 31 is in contact with the valve protrusion 44 (FIG. 13C). The stopper penetrating part 52 that was in ()) is separated from the valve protrusion 44 by the relative movement with respect to the valve penetrating part 42. At the same time, the inertial force (load) that causes the movable core 230 to continue to move to the opposite side of the fixed core 20 can be attenuated by the third restoring force F3 that acts on the movable core 230 from the third elastic member 274. According to these, the vibration due to the contact between the core main body 31 and the stopper projection 54 propagates to the valve projection 44, which is unexpected due to the valve member 40 opening the nozzle hole 17 by mistake. Since secondary injection can be avoided, it is possible to control the injection amount with high accuracy.

  Further, according to the inertial movement of the movable elements 230 and 50, the third restoring force F3 is formed after the gap 56a between the elements 31 and 44 and the gap 58 between the elements 52 and 44 are formed as shown in FIG. As a result, the movable core 230, whose inertial force is attenuated, rebounds toward the fixed core 20. As a result, the movable stopper 50 that receives the second restoring force F2 that is larger than the third restoring force F3 moves to the fixed core 20 side, and the stopper penetrating portion 52 contacts the valve projection 44 as shown in FIG. Make contact. However, in the movable core 230 that has bounced back, the core main body 31 can be prevented from contacting the valve protrusion 44 that vibrates the valve member 40 by the presence of the gap 56a, as in the first embodiment. It is possible to avoid unexpected secondary injection due to contact and contribute to high-precision control of the injection amount.

  After the above, also in the second embodiment, as shown in FIG. 13 (f), all of the movable elements 230, 40, 50 stop moving and close the nozzle hole 17 (that is, FIG. 12 (f). In the same state as a), the next valve opening operation corresponding to energization of the coil 60 is awaited.

(Third embodiment)
As shown in FIG. 14, the third embodiment of the present invention is a modification of the second embodiment. In the fuel injection valve 310 of the third embodiment, the third elastic member 374 made of a metal compression coil spring has an end on the opposite side to the locking side by the stepped portion 13c as the fixed core 20 of the stopper projection 54. It is latched by the axial direction end surface 254b on the opposite side. Since the third elastic member 374 having such a locking structure is interposed between the valve housing 12 having the step portion 13c and the movable stopper 50 having the stopper projection 54, the third elastic member 374 is interposed between the elements 12 and 50. It is compressed and elastically deformed. Therefore, the third restoring force F3 (see FIG. 15) generated by the elastic deformation of the third elastic member 374 is a biasing force that biases the movable stopper 50 toward the fixed core 20 with respect to the valve housing 12.

  In such a fuel injection valve 310, assuming the forces Fvs, Fcs, and Fvh as shown in FIG. 15 according to the second embodiment, the restoring forces F1, F2, and F3 of the elastic members 70, 272, and 374 in the closed state are shown. Is adjusted as follows.

As is clear from FIG. 15, the force balance relationship in the valve member 40 is expressed by the following (formula 11), the force balance relationship in the movable stopper 50 is expressed by the following (formula 12), and the force balance in the movable core 230 is The balance relationship is expressed by the following (formula 13).
+ F1-Fvs-Fvh = 0 (Formula 11)
-F2-F3 + Fvs + Fcs = 0 (Formula 12)
F2-Fcs = 0 (Formula 13)

When these (Formula 11), (Formula 12), and (Formula 13) are arranged and solved for each force Fvs, Fcs, and Fvh, the following (Formula 14), (Formula 15), and (Formula 16) are respectively obtained. can get.
Fvs = F3 (Formula 14)
Fcs = F2 (Formula 15)
Fvh = F1-F3 (Expression 16)

In the closed state of the fuel injection valve 310, the magnitudes of the forces Fvs, Fcs, and Fvh need to be larger than 0. Therefore, the right side of (Expression 14)> 0 and the right side of (Expression 15)> 0, and the relationship of the right side of (Equation 16)> 0 holds. Accordingly, the following (Expression 17), (Expression 18), and (Expression 19) are obtained. In particular, in the third embodiment, for each of these expressions, the movable elements 230, 40, and 50 are closed completely. The restoring forces F1, F2, and F3 are adjusted so that the valve closing operation including the valve state is always established. According to the third embodiment, the degree of freedom of adjustment of the restoring forces F2 and F3 is higher than that of the second embodiment that defines the relationship between the restoring forces F2 and F3 according to (Equation 8).
F3> 0 (Expression 17)
F2> 0 (Equation 18)
F1> F3 (Formula 19)

  Since the operation of the fuel injection valve 310 is realized according to the second embodiment except for a part, the operation different from that of the second embodiment will be mainly described below.

  In the closed state immediately before the start of energization as shown in FIG. 14, the stopper projection 54 is urged toward the fixed core 20 by the restoring forces F2 and F3 of the second and third elastic members 272 and 374. Therefore, the movable core 230 that is biased toward the opposite side of the fixed core 20 by the second restoring force F2 of the second elastic member 272 is a stopper protrusion that is biased toward the fixed core 20 in the valve-closed state. It can contact | abut to the part 54 from the said fixed core 20 side, and can be latched reliably. As a result, in the valve opening operation after the start of energization, the gap 56a having a stable size is secured, the moving time of the valve member 40 is stabilized, and the gap between the cores 230 and 20 is kept at a constant distance, so that the movable core 230 is maintained. The travel time is stable. Moreover, in the valve opening operation of the third embodiment, the movable core 230 moves without the valve member 40 according to the same principle as the second embodiment, and then moves with the valve member 40 to collide with the fixed core 20. The moving time of the valve member 40 can be shortened. For these reasons, in the third embodiment, for example, it is possible to suppress variations in the minimum injection amount and contribute to highly accurate injection amount control.

  Further, in the valve closing operation, when the stopper penetrating portion 52 is separated from the valve protrusion 44 as shown in FIG. 16 by the same principle as in the second embodiment, the core main body portion 31 is driven by the second restoring force F2 of the second elastic member 272. The third restoring force F3 of the third elastic member 374 acts on the stopper projection 54 that is in contact with the first elastic member 374. As a result, since the movable core 230 receives the third restoring force F3 toward the fixed core 20 via the stopper protrusion 54, the inertial force (continuous movement to the opposite side of the fixed core 20 ( Per load). Accordingly, also in the third embodiment, unexpected secondary injection due to the valve member 40 opening the injection hole 17 by mistake can be avoided, so that the injection amount can be controlled with high accuracy.

(Fourth embodiment)
As shown in FIG. 17, the fourth embodiment of the present invention is a modification of the second embodiment. In the fuel injection valve 410 of the fourth embodiment, the third elastic member 274 described in the second embodiment is not provided, and the stopper penetrating portion 452 of the movable stopper 450 is fixed to the valve penetrating portion 42 of the valve member 40. Yes. Here, in particular, with respect to the movable stopper 450 made of a non-magnetic material, the stopper protrusion 54 protrudes from the axial intermediate portion 452a of the stopper penetrating portion 452 to the outer peripheral side, and is opposite to the valve protruding portion 44 of the penetrating portion 452. The axial end portion 452b on the side is fixed to the valve penetration portion 42 made of a nonmagnetic material by welding or the like. When the fuel injection valve 410 is manufactured, the through portions 42 and 452 are joined by welding or the like in a state where the stopper through portion 452 into which the valve through portion 42 is inserted is pressed against the valve projection 44 as shown in FIG. Thus, the gap 56 a can be appropriately secured between the valve protrusion 44 and the core main body 31.

Here, as is clear from FIG. 19, in the fuel injection valve 310, the force Fvs among the forces Fvs, Fcs, and Fvh assumed in the second embodiment becomes 0 by fixing the movable stopper 450 to the valve member 40. In the second embodiment, the third restoring force F3 generated is also zero because there is no third elastic member 274. For these reasons, in the fourth embodiment, the following (Expression 20) and (Expression 21) are simply satisfied, and the degree of freedom of adjustment of the restoring forces F1 and F2 of the elastic members 70 and 272 is increased. Yes.
Fcs = F2> 0 (Equation 20)
Fvh = F1> 0 (Expression 21)

(Valve opening operation)
Hereinafter, the valve opening operation among the operations of the fuel injection valve 410 will be described in detail. When energization of the coil 60 is started in the valve-closed state shown in FIG. 20A, the movable core 230 that receives the magnetic attraction force on the core body 31 is fixed against the second restoring force F2 of the second elastic member 272. The movement to the core 20 side is started. Here, in the energization stop state immediately before (that is, the valve closed state in FIG. 20A), the stopper penetration 52 is held by the stopper projection 54 in the same manner as in the second embodiment. It protrudes from the end surface 31 a and abuts on the valve protrusion 44. Therefore, at the time of starting energization, the movable core 230 first moves without the valve member 40 by the valve protrusion side gap 56a.

  Thereafter, the movable core 230 that continues to move by energizing the coil 60 causes the core main body 31 to contact the valve protrusion 44 from the opposite side to the fixed core 20 as shown in FIG. The valve projection 44 is pressed against the first restoring force F1 of the first elastic member 70. As a result, the integrated member of the valve member 40 and the movable stopper 450 moves together with the movable core 230 toward the fixed core 20, so that the seat portion 41 moves away from the valve seat 18 and fuel is injected from the injection hole 17. At this time, the core protrusion 31 is brought into contact with the valve protrusion 44 with which the stopper penetrating portion 452 is contacted in the integrated product, so that the stopper protrusion in the elastically deformed state of the disc spring forming the second elastic member 272. A side gap 56b is formed between the stopper projection 54 and the core body 31 in the maximum size.

  When the movement of the movable core 230 is continued in this way, the core body 31 collides with the fixed core 20 as shown in FIG. 20C, and the valve member 40 continues the inertial movement as shown in FIG. As a result, the valve penetrating portion 42 to which the stopper penetrating portion 452 is fixed moves relative to the core main body portion 31, so that the valve protrusion 44 is separated from the core main body portion 31. Therefore, as in the second embodiment, the rebound force of the movable core 230 that receives the collision reaction force from the fixed core 20 is caused by accidentally closing the nozzle hole 17 for the valve member 40 that is difficult to propagate to the valve protrusion 44. Variations in the fuel injection amount can be avoided.

  As described above, in the fourth embodiment, the movable core 230 is accelerated by the movement not accompanied by the valve member 40 and collides with the valve protrusion 44 in the same manner as in the second embodiment. Therefore, according to the momentum at the time of the collision. The applied impact force can be applied to the valve projection 44 to move the valve member 40 quickly. Therefore, the movement time of the valve member 40 for the distance necessary to open the nozzle hole 17 can be shortened. Furthermore, in the fourth embodiment, the movable core 230 urged to the opposite side of the fixed core 20 by the second restoring force F2 in the valve-closed state of FIG. 20A is moved to the fixed core 20 side by the same restoring force F2. It can contact | abut to the stopper protrusion 54 urged | biased from the said fixed core 20 side, and can be latched reliably. As a result, a gap 56a having a stable size is secured to stabilize the movement time of the valve member 40, and the gap between the cores 230 and 20 is maintained at a constant distance, so that the movement time of the movable core 230 is stabilized. . Therefore, for example, even when fuel is injected in a short time and the minimum injection amount is reduced to atomize the injected fuel, variation in the minimum injection amount is suppressed and high accuracy is achieved. It is possible to contribute to proper injection amount control.

  As in the second embodiment, in the fourth embodiment, the valve penetrating portion 452 of the movable stopper 450 is within the narrowest possible range in the radial direction according to the principle described in the first embodiment. It can come into contact with the valve protrusion 44. Therefore, the time required from the start of the valve opening operation to the start of movement of the valve member 40 can be shortened, and the valve opening response can be improved.

(Valve closing operation)
Next, the valve closing operation among the operations of the fuel injection valve 410 will be described in detail. As shown in FIG. 21A, when the energization of the coil 60 is stopped after each movable element 230, 40, 450 stops moving by the previous valve opening operation, the valve protrusion 44 is moved from the fixed core 20 side to the element. The magnetic attraction force acting on the core main body 31 disappears in a state where it abuts on the cores 45 and 452. Then, the movable core 230 is pressed to the opposite side to the fixed core 20 by the valve protrusion 44 that receives the first restoring force F1 of the first elastic member 70, and thus the movement to the opposite side with the valve member 40 is performed. Start with an integrated product with the movable stopper 450.

  As a result, the seat portion 41 is seated on the valve seat 18 and the movement of the valve member 40 and the fuel injection are stopped.At this time, the movable core 230 having a gap 56b between the stopper projection 54 and The second restoring force F2 of the second elastic member 272 acts together with the inertial force. As a result, the movable core 230 continues to move to the opposite side of the fixed core 20 while moving relative to the through portions 452 and 42 as shown in FIG. Then, as shown in FIGS. 21B and 21C, the movable core 230 causes the core body 31 to be separated from the valve protrusion 44, and further, the core body 31 is brought into contact with the stopper protrusion 54. The valve projection 44 is stopped in a state where the valve projection side gap 56a is formed between the valve projection 44 and the valve projection 44. Therefore, even if the core main body 31 bounces back to the fixed core 20 due to contact with the stopper protrusion 54, the core main body 31 contacts the valve protrusion 44 and gives vibration. The presence of the gap 56 a between 31 and 44 can be suppressed. Therefore, the unexpected secondary injection resulting from the contact between the movable core 230 bounced back to the fixed core 20 and the valve member 40 can be avoided, thereby contributing to highly accurate injection amount control.

  As described above, also in the fourth embodiment, as shown in FIG. 21C, all of the movable elements 230, 40, and 450 stop moving and close the nozzle hole 17 (that is, the same state as FIG. 20A). ), The next valve opening operation corresponding to the energization of the coil 60 is awaited.

(Other embodiments)
Although a plurality of embodiments of the present invention have been described so far, the present invention is not construed as being limited to these embodiments, and can be applied to various embodiments and combinations without departing from the scope of the present invention. can do.

  Specifically, the movable stoppers 50 and 450 of the first to fourth embodiments need not be cylindrical members as a whole as long as the functions of the portions 52 and 54 can be exhibited. One or a plurality of letter-shaped members may be arranged in the circumferential direction of the movable cores 30 and 230 and the valve member 40 as the movable stoppers 50 and 450. Further, in the case where the L-shaped movable stopper 50 is employed in the first to third embodiments, it is not necessary to be interposed between the movable cores 30 and 230 and the valve member 40, and the movable cores 30 and 230. In this case, the stopper penetrating portion 52 of the stopper 50 may be penetrated at a location spaced radially outward from the core through hole 32 into which the valve penetrating portion 42 is directly fitted.

  Furthermore, in the first embodiment, a third elastic member 374 that biases the movable stopper 50 according to the third embodiment may be employed instead of the third elastic member 274 that biases the movable core 30. . Furthermore, in 1st embodiment, instead of employ | adopting the movable stopper 50 provided with relative movement with respect to the valve member 40, according to 4th embodiment, it is fixed with respect to the valve member 40 so that integral movement is possible. The movable stopper 450 may be employed and the third elastic member 74 may be omitted. In addition, in the first to third embodiments, the gap 56 (56a) between the core body 31 and the valve protrusion 44 is not formed when the core body 31 is in contact with the stopper protrusion 54. Also good. In this case, the adjustment of the first restoring force F1 or the like causes the movable cores 30 and 230 that have bounced back to the fixed core 20 side and the valve member 40 to contact with each other only in the gap 58 between the stopper penetration 52 and the valve protrusion 44. It is desirable to suppress.

10, 210, 310, 410 Fuel injection valve, 12 Valve housing, 13 First magnetic part, 13a Small diameter part, 13b Large diameter part, 13c Step part, 14 Nonmagnetic part, 15 Second magnetic part, 16 Nozzle part, 17 Injection hole, 18 Valve seat, 19 Fuel inlet, 20 Fixed core, 21 Housing hole, 22 Adjusting pipe, 30, 230 Movable core, 31 Core body, 31a, 31b Axial end face, 32 Core through hole, 33, 233 Core accommodating part, 34 Core protrusion, 40 Valve member, 41 Seat part, 42 Valve penetration part, 44 Valve protrusion, 44a, 44b Axial end face, 46 Fuel hole, 48 Fuel passage, 50, 450 Movable stopper, 52, 452 Stopper penetration part, 54 Stopper protrusion, 54a Axial end face, 56, 58 clearance, 56a Valve protrusion side clearance, 56b Stopper protrusion side clearance , 60 coils, 62 magnetic yoke, 70 first elastic member, 72,272 second elastic member, 74,274,374 third elastic member, 233a, 254b axial end surface, 272a outer peripheral portion, 272b inner peripheral portion, 452a shaft Direction intermediate portion, 452b Axial end portion, F1 first restoring force, F2 second restoring force, F3 third restoring force, δF set value

Claims (12)

A valve housing having nozzle holes for injecting fuel into the internal combustion engine;
A fixed core fixed to the valve housing;
A movable core that moves to the fixed core side by the action of a magnetic attractive force;
A coil for generating the magnetic attraction force by energization in the valve opening operation for opening the nozzle hole, while eliminating the magnetic attraction force by stopping energization in the valve closing operation for closing the nozzle hole;
A valve penetrating portion penetrating the movable core, and a valve projecting portion protruding from the valve penetrating portion and capable of coming into contact with the movable core from the fixed core side. A valve member for intermittent injection;
A stopper penetrating portion that penetrates through the movable core and protrudes from an end surface of the movable core on the fixed core side, and in a state of stopping energization of the coil, A movable stopper that forms a gap between the valve projection and the locked movable core by abutting from the opposite side of the fixed core;
A fuel injection valve comprising: 2. The fuel injection valve according to claim 1, wherein the movable stopper has a stopper protrusion that protrudes from the stopper penetrating portion and can come into contact with the movable core from a side opposite to the fixed core. A first elastic member for generating a first restoring force for urging the valve member to the opposite side of the fixed core with respect to the valve housing;
A second elastic member for generating a second restoring force for urging the movable core toward the opposite side of the fixed core and urging the movable stopper toward the fixed core;
A third elastic member for generating a third restoring force for urging the movable core toward the fixed core with respect to the valve housing;
With
The fuel injection valve according to claim 2, wherein the movable stopper is provided so as to be movable relative to the valve member toward the fixed core and the opposite side thereof.   The fuel injection valve according to claim 3, wherein the second restoring force is greater than the third restoring force in the valve closing operation.   The fuel injection valve according to claim 4, wherein a difference between the second restoring force and the third restoring force is suppressed to a set value or less in the valve closing operation. A first elastic member for generating a first restoring force for urging the valve member to the opposite side of the fixed core with respect to the valve housing;
A second elastic member for generating a second restoring force for urging the movable core toward the opposite side of the fixed core and urging the movable stopper toward the fixed core;
A third elastic member for generating a third restoring force for urging the movable stopper toward the fixed core with respect to the valve housing;
With
The fuel injection valve according to claim 2, wherein the movable stopper is provided so as to be movable relative to the valve member toward the fixed core and the opposite side thereof.   The movable stopper is between the movable core and the valve protrusion and between the movable core and the stopper protrusion, with the stopper penetrating portion being in contact with the valve protrusion so as to be separable. The fuel injection valve according to any one of claims 3 to 6, wherein a gap is formed in at least one of the operations according to the operation of the fuel injection valve. A first elastic member for generating a first restoring force for urging the valve member to the opposite side of the fixed core;
A second elastic member for generating a second restoring force for urging the movable core toward the opposite side of the fixed core and urging the movable stopper toward the fixed core;
With
The fuel injection valve according to claim 2, wherein the movable stopper is fixed to the valve member so as to be movable integrally with the fixed core and the opposite side thereof.   The movable stopper includes the fuel injection unit between the movable core and the valve projection and between the movable core and the stopper projection, with the stopper penetrating portion in contact with the valve projection. The fuel injection valve according to claim 8, wherein a gap is formed in at least one of the valves in accordance with the operation of the valve.   The said stopper penetration part is formed in the cylinder shape in which the said valve penetration part is inserted in the inner peripheral side of the cylindrical said movable core, The Claim 1 characterized by the above-mentioned. Fuel injection valve. The movable core has a core main body portion that forms an end face on the fixed core side so as to be able to contact the valve protrusion, and protrudes from the core main body portion to the opposite side of the fixed core so that the stopper protrusion is on the inner peripheral side. A core housing portion to be housed, and a core protrusion projecting from the core housing portion to the inner peripheral side,
The said 2nd elastic member consists of a coil spring accommodated in the inner peripheral side of the said core accommodating part, and interposed between the said stopper protrusion and the said core protrusion. The fuel injection valve according to any one of the above. The movable core has a core main body portion that forms an end face on the fixed core side so as to be able to contact the valve protrusion, and protrudes from the core main body portion to the opposite side of the fixed core so that the stopper protrusion is on the inner peripheral side. Having a core accommodating portion for accommodating
The said 2nd elastic member consists of a disk spring with which an outer peripheral part is fixed to the said core accommodating part, and an inner peripheral part engages with the said stopper protrusion. The fuel injection valve described in 1.

Images