JP5019137B2 - Electromagnetically driven valve and fuel injection device using the same - Google Patents

Description

  The present invention relates to an electromagnetically driven valve that drives a valve member by the magnetic force of a coil, and a fuel injection device using the same.

Conventionally, a fuel that opens and closes a fuel passage by generating a suction force between a fixed core and a movable core by energizing a coil and separating and seating a valve member that drives with the movable core on a valve seat. An injection device is known (see Patent Documents 1 and 2).
In this type of fuel injection device, a valve opening response of the valve member is improved by supplying a large current more than that required for attracting the movable core and increasing the rising speed of the current value.

JP 2000-8990 A JP 2001-165014 A

However, in the conventional fuel injection device, when the magnetic flux flowing through the movable core and the fixed core is saturated, no more attractive force is generated even if a large current is supplied to the coil. For this reason, it has been difficult to increase the driving force of the valve member more than the saturation condition of the magnetic flux.
The present invention has been made in view of the above problems, and an object thereof is to provide an electromagnetically driven valve capable of increasing the driving force of the valve member by assisting the operation of the valve member.
Moreover, the objective of this invention is providing the fuel-injection apparatus which can improve the responsiveness of a valve member by using the said electromagnetically driven valve.

  According to the first aspect of the present invention, the fixed core, the first movable core, and the second movable core are provided in the magnetic field generated by the coil that generates a magnetic field when energized to form a magnetic circuit. The urging means transmits the fluid pressure generated in the moving region of the second movable core to the pressure chamber, and urges the first movable core toward the fixed core. It is possible to convert the electrical energy input to the coil into an attractive force with high efficiency by forming two attractive parts with a fixed core, first movable core and second movable core in one magnetic circuit. It becomes. Then, the biasing means transmits the fluid pressure generated in the moving region of the second movable core to the pressure chamber and biases the first movable core, thereby assisting the operation of the valve member and reducing the driving force of the valve member. Can be increased.

  According to the invention which concerns on Claim 2, a 1st movable core is provided in the one end side of the axial direction of a fixed core, and a 2nd movable core is provided in the other end side of the axial direction of a fixed core. By using the magnetic poles formed at both ends of the fixed core, a large suction force is obtained in the first and second suction portions, and the driving force of the valve member can be increased.

  According to the invention which concerns on Claim 3, a 1st suction part is provided in the radial direction inner side of a coil, and a 2nd suction part is provided in the radial direction outer side of a coil. By providing the first suction part and the second suction part in the radial direction with the coil interposed therebetween, the fluid pressure generated in the moving region of the second movable core can be directly transmitted to the pressure chamber over a short distance.

  According to the invention which concerns on Claim 4, a biasing means guides the fluid in the movement area | region of a 2nd movable core to a pressure chamber by the pipe member which passes a fixed core and a 1st movable core in an axial direction. Thereby, the fluid pressure generated in the moving region of the second movable core can be reliably transmitted to the pressure chamber without increasing the physique in the radial direction of the electromagnetically driven valve.

  According to the fifth aspect of the present invention, the urging means guides the fluid in the moving region of the second movable core to the pressure chamber through the communication passage provided outside in the radial direction of the coil. Thereby, the location where the fluid leaks from the communication passage can be reduced.

  According to the invention of claim 6, the urging means includes an upper through hole that passes through the fixed core in the axial direction, a lower through hole that is provided coaxially with the upper through hole and passes through the first movable core in the axial direction, and the second through hole. The piston extends from the movable core and is inserted into the upper through hole and the lower through hole. The piston driven with the second movable core can directly increase the fluid pressure in the pressure chamber.

  According to the invention which concerns on Claim 7, a fixed core, a 1st movable core, and a 2nd movable core are provided in the magnetic field which a coil generate | occur | produces, and a magnetic circuit is formed. The second urging means transmits the fuel pressure generated in the moving region of the second movable core to the second pressure chamber provided on the opposite side of the moving direction of the valve member, and the valve member is driven by the fluid pressure in the second pressure chamber. Energize in the moving direction. Without the first movable core, the operation of the valve member is directly assisted by the second urging means, and the driving force of the valve member can be increased.

  According to the eighth aspect of the present invention, the second urging means includes a pressurizing chamber provided inside the valve member, a communication passage communicating the pressurizing chamber and the second pressure chamber inside the valve member, 2 A shaft member extending in the axial direction from the movable core and inserted into the pressurizing chamber. The shaft member pushes the fluid in the pressurizing chamber to the second pressure chamber via the communication path, so that the fluid pressure in the pressurizing chamber can be reliably transmitted to the second pressure chamber.

  According to the ninth aspect of the present invention, the valve member provided inside the valve body having the fuel passage to which fuel is supplied and the valve seat opens the fuel passage by separating from the valve seat when the coil is energized. When the energization of the coil is cut off, the fuel passage is closed by seating on the valve seat. By using an electromagnetically driven valve having a high driving force of the valve member for the fuel injection device, it becomes possible to inject the designated injection amount in a short time, and thus the injection amount control can be performed reliably. Therefore, it is suitable for multi-injection in which the command injection amount is injected a plurality of times in one combustion cycle, and the combustion efficiency can be improved.

It is sectional drawing of the fuel-injection apparatus by 1st Embodiment of this invention. FIG. 3 is an operation diagram of the fuel injection device according to the first embodiment of the present invention. FIG. 3 is an operation diagram of the fuel injection device according to the first embodiment of the present invention. FIG. 3 is an operation diagram of the fuel injection device according to the first embodiment of the present invention. FIG. 3 is an operation diagram of the fuel injection device according to the first embodiment of the present invention. (A) is sectional drawing of the model corresponding to the fuel-injection apparatus by 1st Embodiment of this invention, (B) is sectional drawing of the model corresponding to the conventional fuel-injection apparatus. It is a characteristic view which compared the fuel injection device by 1st Embodiment of this invention, and the conventional fuel injection device. 1 is a schematic diagram of a fuel injection device according to a first embodiment of the present invention. It is a characteristic view which compared the fuel injection device by 1st Embodiment of this invention, and the conventional fuel injection device. It is sectional drawing of the fuel-injection apparatus by 2nd Embodiment of this invention. It is sectional drawing of the fuel-injection apparatus by 3rd Embodiment of this invention. It is sectional drawing of the fuel-injection apparatus by 4th Embodiment of this invention. It is sectional drawing of the fuel-injection apparatus by 5th Embodiment of this invention. FIG. 9 is an operation diagram of a fuel injection device according to a fifth embodiment of the present invention. FIG. 9 is an operation diagram of a fuel injection device according to a fifth embodiment of the present invention. It is an operation | movement figure of the fuel-injection apparatus by 6th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
The first embodiment of the present invention corresponds to the invention described in claims 1, 2, 4 and 9.
The fuel injection device according to the present embodiment is applied to, for example, a direct injection type gasoline engine, and directly injects and supplies high-pressure fuel supplied from a fuel rail that accumulates fuel boosted by a fuel pump into a combustion chamber.

As shown in FIG. 1, the fuel injection device includes a valve body 10, a valve member 20, a coil 30, a fixed core 40, a first movable core 50, a second movable core 60, a pipe member 70, and the like.
The valve body 10 is formed in a cylindrical shape and has a fuel passage 11 inside. A fuel inlet 12 to which fuel is supplied is provided at one end of the valve body 10 in the axial direction. The valve body 10 has a first magnetic part 101, a first nonmagnetic part 102, a second magnetic part 103, a second nonmagnetic part 104, and a third magnetic part 105 in this order from the fuel inlet 12 side. The first nonmagnetic portion 102 prevents a magnetic flux from being short-circuited between the first magnetic portion 101 and the second magnetic portion 103, and the second nonmagnetic portion 104 is formed between the second magnetic portion 103 and the third magnetic portion 105. The magnetic flux is prevented from being short-circuited between them.

The valve body 10 has a nozzle portion 13 at the other end in the axial direction. The nozzle portion 13 has a nozzle hole 14 for injecting fuel into the outside at the tip, and a valve seat 15 on the inner wall on the upstream side of the nozzle hole 14.
A valve member 20 formed in a substantially cylindrical shape is accommodated inside the valve body 10 so as to be capable of reciprocating in the axial direction. The valve member 20 has a conical seat portion 21 at the end on the nozzle hole 14 side. When the seat portion 21 is seated and separated from the valve seat 15, the fuel passage 16 inside the nozzle portion 13 is opened and closed, and fuel injection is intermittently performed from the injection hole 14.

The coil 30 is wound around the radially outer side of the valve body 10. A yoke 31 made of a magnetic material is provided around the coil 30. The yoke 31 magnetically connects the first magnetic part 101 and the third magnetic part 105.
The fixed core 40 is formed in a cylindrical shape from a magnetic material, and is fixed to the inner wall of the valve body 10 by press-fitting or the like on the radially inner side of the coil 30. The fixed core 40 is provided with a fuel passage 41 through which fuel passes in the axial direction. A first recess 42 having a large inner diameter is provided on the nozzle hole 14 side of the fuel passage 41 to accommodate the first spring 43. A second recess 44 having a large inner diameter is provided on the fuel inlet 12 side of the fuel passage 41 and accommodates the second spring 45.

The first movable core 50 is formed in a cylindrical shape from a magnetic material, and is provided so as to be capable of reciprocating in the axial direction on the nozzle hole 14 side of the fixed core 40. A first gap 55 is provided between the fixed core 40 and the first movable core 50, and the first suction portion is configured including the fixed core 40, the first movable core 50, and the first gap 55. The first movable core 50 is provided with a shaft hole 51 through which the valve member 20 passes in the axial direction. A flange 22 is provided at the end of the valve member 20 on the fuel inlet 12 side. The flange 22 is biased by the first spring 43 and is in contact with the outer wall of the first movable core 50 on the fuel inlet 12 side.
On the radially outer side of the end portion of the first movable core 50 on the nozzle hole 14 side, an annular outer ring 52 that protrudes toward the nozzle hole 14 side is provided. An annular inner ring 53 protruding toward the nozzle hole 14 is provided around the shaft hole 51 at the end of the first movable core 50 on the nozzle hole 14 side. The outer ring 52 and the inner ring 53 are slidable in a liquid-tight manner in the outer concave portion 17 and the inner concave portion 18 provided on the inner wall of the valve body 10, respectively. Thus, a pressure chamber 54 is formed by the outer wall of the first movable core 50 on the injection hole 14 side, the inner wall of the outer ring 52, the outer wall of the inner ring 53, and the inner wall of the valve body 10.

The second movable core 60 is formed in a cylindrical shape from a magnetic material, and is provided so as to reciprocate in the axial direction on the fuel inlet 12 side of the fixed core 40. A second gap 65 is provided between the fixed core 40 and the second movable core 60, and the second suction part is configured including the fixed core 40, the second movable core 60, and the second gap 65. The second movable core 60 is provided with a fuel passage 61 through which fuel passes in the axial direction. Around the fuel passage 61 at the end of the second movable core 60 on the injection hole 14 side, an annular inner ring 62 protruding toward the injection hole 14 is provided. The outer wall of the inner ring 62 can slide in a liquid-tight manner with the inner wall of the second recess 44 of the fixed core 40.
In the second movable core 60, the end of the inner ring 62 is urged by the second spring 45. The movement of the second movable core 60 toward the fuel inlet 12 is restricted by the stopper 19 provided on the inner wall of the valve body 10.

The pipe members 70 are inserted into holes provided in the fixed core 40 and the first movable core 50, and are provided, for example, at six locations in the circumferential direction. The pipe member 70 is fixed to the inner wall of the hole of the fixed core 40 by press fitting or the like, and can slide in a liquid-tight manner with the inner wall of the hole of the first movable core 50. The pipe member 70 communicates the second gap 65 and the pressure chamber 54 by an inner passage 71 that communicates in the axial direction.
In this embodiment, the pipe member 70, the second gap 65, and the pressure chamber 54 correspond to the urging means described in the claims.

Next, the operation of the fuel injection device 1 will be described.
When the energization of the coil 30 is stopped, the valve member 20 has an injection hole due to the force that the fuel pressure in the fuel passage acts on the area corresponding to the cross section of the seat portion 21 and the elastic force of the first spring 43. 14 is biased to the side. Therefore, the first movable core 50 is urged by the flange 22 of the valve member 20, and the outer walls on the injection hole 14 side of the outer ring 52 and the inner ring 53 are the inner walls of the outer recess 17 and the inner recess 18 of the valve body 10, respectively. Abut.
On the other hand, the second movable core 60 is biased toward the fuel inlet 12 by the elastic force of the second spring 45. For this reason, the outer wall of the second movable core 60 on the fuel inlet 12 side is in contact with the outer wall of the stopper 19.
Since the seat portion 21 of the valve member 20 is seated on the valve seat 15 and closes the fuel passage 16, fuel injection from the injection hole 14 is blocked.

  When the coil 30 is energized, the yoke 31, the third magnetic part 105, the first movable core 50, the fixed core 40, the second movable core 60 and the first magnetic field are generated by the magnetic field generated by the coil 30, as shown in FIG. Magnetic flux flows through the magnetic circuit formed by the magnetic part 101 as indicated by an arrow A. Thereby, a suction force is generated in the first suction portion and the second suction portion. At this time, when the suction force B generated in the second suction portion becomes larger than the elastic force of the second spring 45, the second movable core 60 starts moving toward the fixed core 40 side. As a result, the fuel in the second gap 65 serving as the moving region of the second movable core 60 is pressurized by being compressed by the second movable core 60.

  As the fuel pressure in the second gap 65 increases, the fuel pressure in the pressure chamber 54 communicated by the pipe member 70 increases. As shown in FIG. 3, the resultant force of the force C acting on the surface of the first movable core on the pressure chamber 54 side of the first movable core and the suction force D generated in the first suction portion is When the fuel pressure becomes larger than the resultant force of the area corresponding to the cross section of the seat portion 21 of the valve member 20 and the force acting on the surface of the first movable core 50 on the fuel inlet 12 side, and the elastic force of the first spring 43, The first movable core 50 moves to the fixed core 40 side. Along with this, the valve member 20 moves to the fuel inlet 12 side, the seat portion 21 moves away from the valve seat 15, the fuel passage 16 is opened, and fuel is injected from the injection hole 14.

  When energization of the coil 30 is stopped, the suction force of the first suction part and the second suction part disappears. Therefore, as shown in FIG. 4, the first movable core 50 moves to the injection hole 14 side by the elastic force E of the first spring 43, and the second movable core 60 moves to the fuel inlet by the elastic force F of the second spring 45. Move to the 12th side. At this time, the movement of the first movable core 50 toward the nozzle hole 14 is suppressed by the fuel pressure in the pressure chamber 54. On the other hand, the movement of the second movable core 60 toward the fuel inlet 12 is accelerated by the fuel pressure G in the second gap 65 compressed by the second movable core 60. For this reason, the second movable core 60 moves faster than the first movable core 50.

  As the valve member 20 moves to the injection hole 14 side, the distance between the seat portion 21 and the valve seat 15 decreases, and the fuel pressure acting on the valve member 20 increases toward the injection hole 14 side. As shown in FIG. 5, when the seat portion 21 is seated on the valve seat 15, the fuel passage 16 is closed by the force H applied to the valve member 20 by the fuel pressure in the fuel passage and the elastic force E of the first spring 43. One fuel injection is completed.

Next, the drive performance of the fuel injection device of the present embodiment and a conventional fuel injection device having one movable core will be compared.
The electromagnetic force acting on each movable core was analyzed for a model corresponding to the fuel injection device of the present embodiment shown in FIG. 6A and a model corresponding to the conventional fuel injection device shown in FIG.
The model corresponding to the fuel injection device of the present embodiment is given the same reference numerals as the configuration of the fuel injection device of the present embodiment. Further, a model corresponding to the conventional fuel injection device is denoted by a reference numeral “a” added to the configuration corresponding to the configuration of the fuel injection device of the present embodiment. In this analysis, the influence of fuel pressure or the like is not taken into consideration.

As shown in FIG. 7A, currents having the same circuit settings were supplied to the coils 30 and 30a of the model corresponding to the fuel injection device of this embodiment and the model corresponding to the conventional fuel injection device. The current value supplied to the coil 30 of the model corresponding to the fuel injection device of the present embodiment is indicated by a dotted line I, and the current value supplied to the coil 30a of the model corresponding to the conventional fuel injection device is indicated by a solid line J.
To cope with high pressure fuel and increase the valve opening speed, a large current of about 10 A at maximum was supplied between about 0.6 ms and about 1.3 ms. Thereafter, in order to keep the valve member open, a current of about 2 A was supplied until about 3 ms. A slight difference was observed in the current value due to the difference in shape between the model corresponding to the fuel injection device of this embodiment and the model corresponding to the conventional fuel injection device.

Under the conditions shown in FIGS. 6A, 6B, and 7A, the first movable core 50, the second movable core 60, and the conventional fuel injection of the model corresponding to the fuel injection device of the present embodiment. FIG. 7B shows the electromagnetic force acting on the movable core 50a of the model corresponding to the apparatus. The electromagnetic force acting on the second movable core 60 of the model corresponding to the fuel injection device of the present embodiment is indicated by a dotted line K, and the electromagnetic force acting on the first movable core 50 is indicated by a one-dot chain line L. A solid line M indicates an electromagnetic force acting on a movable core 50a of a model corresponding to a conventional fuel injection device.
At a time of about 1.3 ms, surplus current exceeding the saturation condition of the magnetic flux is supplied to each of the coils 30 and 30a. Therefore, the electromagnetic acting on the first movable core 50 of the model corresponding to the fuel injection device of the present embodiment. The maximum value of the force, the electromagnetic force acting on the second movable core 60, and the electromagnetic force acting on the movable core 50a of the conventional fuel injection device was about 100 N, respectively.
Moreover, since there is no surplus current in the model corresponding to the fuel injection device of the present embodiment having two movable cores at about 3 ms, the electromagnetic forces acting on the first movable core 50 and the second movable core 60 are respectively About 45N. On the other hand, since a model corresponding to the conventional fuel injection device has surplus current, the electromagnetic force acting on the movable core 50a is about 60N.

Based on the above test results, in the fuel injection device 1 of the present embodiment, the assisting force that assists the action of the first movable core 50 by the suction force acting on the second movable core 60 will be examined.
FIG. 8 shows a schematic diagram of a cross section of the second gap 65, the inner passage 71 of the pipe member, and the pressure chamber 54 in a state where the coil 30 is not energized. The inner passage 71 of the pipe member is provided at six places in the circumferential direction.

The surface area of the second movable core 60 facing the second gap 65 is
(4 ² −2.5 ² ) π≈30.6 (mm ² ).
The surface area of the first movable core 50 facing the pressure chamber 54 is:
(4 ² −2 ² ) π−0.5 ² π · 6≈32.9 (mm ² ).
Therefore, assuming that the suction force acting on the second movable core 60 is 100 N, the assist force acting on the first movable core 50 is calculated by the following equation. Note that fuel leakage in the second gap 65, the inner passage 71, and the pressure chamber 54 is not considered.

Therefore, the assist force acting on the first movable core 50 is 107.7N.
FIG. 9 shows a comparison between the drive performance of the fuel injection device 1 of the present embodiment and the conventional fuel injection device derived from the above results. The driving force of the fuel injection device 1 of the present embodiment is indicated by a dotted line N, and the driving force of the conventional fuel injection device is indicated by a solid line O.
As described above, in the fuel injection device 1 of this embodiment, the second movable core 60 is urged toward the fuel inlet 12 by the elastic force of the second spring 45. On the other hand, the first movable core 50 is attached to the injection hole 14 side by the force that the fuel pressure in the fuel passage acts on the area corresponding to the cross section of the seat portion 21 of the valve member 20 and the elastic force of the first spring 43. It is energized. For this reason, when the coil 30 is energized, the second movable core 60 starts to move before the first movable core 50. For this reason, at the time of about 1.3 ms, the first movable core 50 can obtain a driving force of 200 N or more by the assist force by the second movable core 60 and the suction force generated in the first suction part. Therefore, the valve member 20 that operates together with the first movable core 50 has a faster valve opening operation than the conventional fuel injection device, and can obtain approximately twice the driving force.
In addition, after the peak of the driving force, the force with which the first movable core 50 holds the valve member 20 in the valve open state is almost the same as that of the conventional fuel injection device in consideration of fuel leakage in the pressure chamber 54 and the like. It will be the same.

In this embodiment, the 1st attraction | suction part and the 2nd attraction | suction part are provided in one magnetic circuit. For this reason, it is possible to convert the electric energy that has been excessively supplied in the conventional fuel injection device into a suction force with high efficiency. By connecting the second gap 65 and the pressure chamber 54 with the inner passage 71 of the pipe member 70, the suction force generated in the second suction portion can be used as the assist force of the first movable core 50. Thereby, the valve opening responsiveness and driving force of the valve member 20 can be improved. Therefore, it becomes possible to inject the designated injection amount in a short time, and the injection amount control can be reliably performed.
In addition, it becomes possible to enlarge the load of the 1st spring 43 by raising the drive force of the valve member 20, and can improve valve closing response.

(Second Embodiment)
A fuel injection device according to a second embodiment of the present invention is shown in FIG. This embodiment corresponds to the invention described in claims 3 and 9. Hereinafter, in a plurality of embodiments, the same numerals are given to the substantially same composition, and explanation is omitted.
In the fuel injection device 2 of the present embodiment, a cylindrical member 80, a second movable core 66, a housing 81, and a second fixed core 82 are provided on the radially outer side of the yoke 31.
The cylindrical member 80 has a fourth magnetic part 84, a third nonmagnetic part 83, and a fifth magnetic part 85. The third nonmagnetic portion 83 prevents a magnetic short circuit between the fourth magnetic portion 84 and the fifth magnetic portion 85.

A cylindrical housing 81 is provided on the radially outer side of the cylindrical member 80 with the second movable core 66 interposed therebetween. The second movable core 66 is formed in a cylindrical shape from a magnetic material, and is accommodated between the cylindrical member 80 and the housing 81 so as to be capable of reciprocating in the axial direction.
A cylindrical second fixed core 82 made of a magnetic material is fixed to the outer wall of the cylindrical member 80 on the axially nozzle hole 14 side of the second movable core 66.
A second spring 67 is provided between the second movable core 66 and the second fixed core 82 to urge the second movable core 66 toward the fuel inlet 12 side. The second movable core 66 is restricted from moving in the axial direction by a stopper 19 provided on the inner wall of the housing 81.

  A communication passage 72 communicates between the second gap 68 provided between the second movable core 66 and the second fixed core 82 and the pressure chamber 54. The communication passage 72 passes through the second fixed core from the second gap 68, and further passes through the valve body 10, the yoke 31, and the tubular member 80 to the pressure chamber 54 in the radial direction.

  When the coil 30 is energized, the yoke 31, the third magnetic part 105, the first movable core 50, the fixed core 40, the second magnetic part 103, the yoke 31, the fourth magnetic part 84, due to the magnetic field generated by the coil 30, Magnetic flux flows through a magnetic circuit formed by the second movable core 66, the second fixed core 82, and the fifth magnetic portion 85. As a result, the first suction portion composed of the first movable core 50, the fixed core 40 and the first gap 55, and the second suction composed of the second movable core 66, the second fixed core 82 and the second gap 68. A suction force is generated in the part. At this time, when the suction force generated in the second suction part becomes larger than the elastic force of the second spring 67, the second movable core 66 starts moving toward the second fixed core 82 side. As a result, the fuel in the second gap 68 is pressurized.

  As the fuel pressure in the second gap 68 increases, the fuel pressure in the pressure chamber 54 communicated by the communication passage 72 increases. The resultant force of the force that the fuel pressure in the pressure chamber 54 acts on the pressure chamber side surface of the first movable core 50 and the suction force generated in the first suction portion is the fuel pressure in the fuel passage that is the seat portion of the valve member 20. When the area corresponding to the cross section of 21 and the force acting on the surface of the first movable core 50 on the fuel inlet 12 side and the resultant force of the first spring 43 are larger, the first movable core 50 is fixed. Move to 40 side. Along with this, the valve member 20 moves to the fuel inlet 12 side, the seat portion 21 moves away from the valve seat 15, the fuel passage 16 is opened, and fuel is injected from the injection hole 14.

  In the present embodiment, the communication passage 72 passes through the valve body 10, the yoke 31 and the tubular member 80 in the radial direction, further passes through the second fixed core in the axial direction, and communicates the pressure chamber 54 and the second gap 68. Yes. For this reason, the assist force of the first movable core 50 can be increased by shortening the transmission distance of the fuel pressure between the second gap 68 and the pressure chamber 54. Therefore, the valve opening response and driving force of the valve member 20 can be enhanced.

(Third embodiment)
A fuel injection device according to a third embodiment of the present invention is shown in FIG. This embodiment corresponds to the invention described in claims 5 and 9.
In the fuel injection device 3 of the present embodiment, a communication passage 74 that communicates the second gap 65 and the pressure chamber 54 is provided on the radially outer side of the coil 30. The communication passage 74 passes from the second gap 65 to the pressure chamber 54 through the first nonmagnetic portion 102 of the valve body 10, the inside of the yoke 31, and the second nonmagnetic portion 104. For this reason, since the location where the fuel leaks from the communication passage 74 can be reduced, the fuel pressure in the second gap 65 can be reliably transmitted to the pressure chamber 54.

(Fourth embodiment)
FIG. 12 shows a fuel injection device according to the fourth embodiment of the present invention. This embodiment corresponds to the inventions described in claims 6 and 9.
In the fuel injection device 4 of the present embodiment, for example, six upper through holes 46 are provided in the circumferential direction through the fixed core 40 in the axial direction. Further, six lower through holes 56 that communicate with the first movable core 50 in the axial direction are provided coaxially with the upper through hole 46 in the circumferential direction.
The second movable core 60 has six pistons 75 extending in the axial direction from the outer wall on the nozzle hole 14 side. The piston 75 is slidable with the inner wall of the upper through hole 46 and is slidable with the inner wall of the lower through hole 56 in a liquid-tight manner.
A through hole 69 provided in the axial direction of the second movable core 60 communicates the second gap and the fuel passage 11 to enhance the operability of the second movable core 60.
In the present embodiment, when the coil 30 is energized, the piston 75 moves to the nozzle hole 14 side together with the second movable core 60. For this reason, the fuel in the pressure chamber 54 is directly pressurized by the piston 75. Therefore, the movement of the first movable core 50 is assisted, and the valve opening response and the driving force of the valve member 20 can be improved.

(Fifth embodiment)
A fuel injection device according to a fifth embodiment of the present invention is shown in FIG. This embodiment corresponds to the invention described in claims 7, 8 and 9.
In the fuel injection device 5 of the present embodiment, the valve member 20 extends into the second recess 44 provided on the fuel inlet 12 side of the fixed core 40. A cylindrical large-diameter portion 23 having a large outer diameter is provided at the end of the valve member 20 on the fuel inlet 12 side. The outer wall in the radial direction of the large-diameter portion 23 slides fluidly with the inner wall of the second recess 44. For this reason, the second pressure chamber 24 is formed between the outer wall on the side of the injection hole 14 in the axial direction of the large diameter portion 23 and the inner wall of the second recess 44.

  The large diameter portion 23 is provided with a concave groove 25 that is recessed from the outer wall on the fuel inlet 12 side toward the injection hole 14 side. On the other hand, the second movable core 60 has a shaft member 90 extending in the axial direction from the outer wall on the injection hole 14 side. The end of the shaft member 90 on the side of the injection hole 14 is inserted into the groove 25 and slides fluidly with the inner wall of the groove 25. For this reason, the pressurizing chamber 26 is formed between the outer wall of the shaft member 90 and the inner wall of the groove 25. The pressurizing chamber 26 and the second pressure chamber 24 communicate with each other through a communication passage 27 provided inside the valve member 20.

When the energization of the coil 30 is stopped, the valve member 20 has an injection hole due to the elastic force of the second spring 91 and the force that the fuel pressure in the fuel passage acts on the area corresponding to the transverse section of the seat portion 21. The seat portion 21 is urged toward the 14 side and is seated on the valve seat 15.
On the other hand, the second movable core 60 is biased toward the fuel inlet 12 by the elastic force of the second spring 91, and the outer wall on the fuel inlet 12 side is in contact with the stopper 19.
The first movable core 50 is urged toward the fuel inlet 12 by the third spring 93, and movement toward the fuel inlet 12 is restricted by the flange 22 of the valve member 20.

  When the coil 30 is energized, the yoke 31, the third magnetic part 105, the first movable core 50, the fixed core 40, the second movable core 60, and the first magnetic part 101 are formed by the magnetic field generated by the coil 30. Magnetic flux flows through the magnetic circuit, and an attractive force is generated in the first suction part and the second suction part. At this time, as shown in FIG. 14, when the second movable core 60 starts moving toward the fixed core 40, the fuel in the pressurizing chamber 26 is pressurized by the shaft member 90 that moves together with the second movable core 60. The As the fuel pressure in the pressurizing chamber 26 increases, the fuel pressure in the second pressure chamber 24 communicated by the communication passage 27 increases.

  As shown in FIG. 15, the resultant force of the fuel P in the second pressure chamber 24 acting on the surface of the large diameter portion 23 on the second pressure chamber 24 side and the suction force Q generated in the first suction portion is the fuel. When the fuel pressure in the passage becomes larger than the resultant force of the force acting on the area corresponding to the cross section of the seat portion 21 of the valve member 20 and the elastic force of the second spring 91, the valve member 20 together with the first movable core 50 It moves to the fuel inlet 12 side. When the seat portion 21 of the valve member 20 is separated from the valve seat 15, the fuel passage 16 is opened, and fuel is injected from the injection hole 14.

  When energization of the coil 30 is stopped, the suction force of the first suction part and the second suction part disappears. Due to the elastic force of the second spring 91, the first movable core 50 and the valve member 20 move to the injection hole 14 side, and the second movable core 60 moves to the fuel inlet 12 side. When the seat portion 21 is seated on the valve seat 15, the fuel passage 16 is closed, and one fuel injection is completed.

  In the present embodiment, the fuel in the pressurizing chamber 26 is pressurized by the shaft member 90 that moves together with the second movable core, and the fuel pressure in the second pressure chamber 24 that communicates with the pressurizing chamber 26 increases. Thereby, the assist force by the suction force generated in the second suction portion can be directly applied to the valve member 20 without the first movable core 50 being interposed. Therefore, loss of assist force can be reduced, and the valve opening response and driving force of the valve member 20 can be increased.

(Sixth embodiment)
FIG. 16 shows a fuel injection device according to a sixth embodiment of the present invention. The present embodiment corresponds to the inventions described in claims 1 to 4 and 7 to 9. In addition, the present embodiment is a combination of the second embodiment and the fifth embodiment.
In the fuel injection device 6 of the present embodiment, the first fixed core 40 is provided on the radially inner side of the coil 30 and the third fixed core 821 is provided on the outer side. A first movable core 50 is provided on the axial direction of the first fixed core 40 on the nozzle hole 14 side, and a second movable core 60 is provided on the fuel inlet 12 side. A third movable core 661 is provided on the fuel inlet 12 side in the axial direction of the third fixed core 821.

When the coil 30 is energized, the yoke 31, the third magnetic part 105, the first movable core 50, the fixed core 40, the second movable core 60, the first magnetic part 101, the yoke 31, and the magnetic field generated by the coil 30 are generated. Magnetic flux flows through a magnetic circuit formed by the fourth magnetic part 84, the third movable core 661, the third fixed core 821, and the fifth magnetic part 85. Thereby, the 1st suction part comprised from the 1st movable core 50, the fixed core 40, and the 1st gap 55, the 2nd suction part comprised from the 2nd movable core 60, the fixed core 40, and the 2nd gap 65, and A suction force is generated in a third suction portion configured by the third movable core 661, the third fixed core 821, and the third gap 681.
When the third movable core 661 starts moving toward the third fixed core 821 due to the suction force generated in the third suction part, the fuel in the third gap 681 is pressurized. As the fuel pressure in the third gap 681 increases, the fuel pressure in the pressure chamber 54 communicated by the communication passage 72 increases.
When the second movable core 60 starts moving toward the first fixed core 40 by the suction force generated in the second suction part, the fuel in the pressurizing chamber 26 is pressurized by the shaft member 90. As the fuel pressure in the pressurizing chamber 26 increases, the fuel pressure in the second pressure chamber 24 communicated by the communication passage 27 increases.

  The fuel pressure in the pressure chamber 54 acts on the pressure chamber 54 side surface of the first movable core 50, and the fuel pressure in the second pressure chamber 24 acts on the second pressure chamber side surface of the large diameter portion 23. Force and the resultant force of the suction force generated in the first suction portion are such that the fuel pressure in the fuel passage corresponds to the area corresponding to the transverse section of the seat portion 21 of the valve member 20 and the surface of the first movable core 50 on the fuel inlet 12 side. When it becomes larger than the resultant force of the acting force and the elastic force of the second spring 91, the valve member 20 moves to the fuel inlet 12 side together with the first movable core 50. When the seat portion 21 of the valve member 20 is separated from the valve seat 15, the fuel passage 16 is opened, and fuel is injected from the injection hole 14.

  When energization of the coil 30 is stopped, the suction force of the first suction part, the second suction part, and the third suction part disappears. Due to the elastic force of the second spring 91, the first movable core 50 and the valve member 20 move to the injection hole 14 side, and the second movable core 60 moves to the fuel inlet 12 side. The third movable core 661 moves toward the fuel inlet 12 due to the elastic force of the third spring 671. When the seat portion 21 is seated on the valve seat 15, the fuel passage 16 is closed, and one fuel injection is completed.

  In the present embodiment, by forming three attracting portions in one magnetic circuit, it is possible to convert the electrical energy input to the coil into attracting force with high efficiency. The suction force generated in the second gap acts on the first movable core 50 via the communication passage 72 and the pressure chamber 54. The first movable core 50 drives the valve member 20 by the suction force generated in the first suction force and the force by which the fuel pressure in the pressure chamber 54 acts on the surface of the first movable core 50 on the pressure chamber 54 side. Further, the suction force generated in the third suction force directly acts on the valve member 20 via the pressurizing chamber 26, the communication path 27, and the second pressure chamber 24. Thereby, the operation of the valve member 20 is assisted, and the valve opening response and driving force of the valve member 20 can be enhanced.

(Other embodiments)
In the above-described embodiments, the direct injection type fuel injection device has been described. In contrast, the present invention may be applied to a fuel injection device such as a port injection type.
In the above-described plurality of embodiments, the electromagnetic drive valve is used for the fuel injection device. In contrast, the electromagnetically driven valve of the present invention can be applied to a drive device that drives various valve members, such as a drive device for an intake valve or an exhaust valve.
As described above, the present invention can be implemented in various embodiments without departing from the spirit of the present invention, in addition to combining the above-described plurality of embodiments.

  DESCRIPTION OF SYMBOLS 1: Fuel injection apparatus, 10: Valve body, 14: Injection hole, 15: Valve seat, 20: Valve member, 30: Coil, 40: Fixed core, 50: 1st movable core, 54: Pressure chamber (biasing means ), 55: first gap, 60: second movable core, 65: second gap (biasing means), 70: pipe member (biasing means), 71: inner passage (biasing means)

Claims (9)

A coil that generates a magnetic field when energized,
A fixed core provided in a magnetic field generated by the coil;
A first movable core provided so as to be movable relative to the fixed core and forming a magnetic circuit together with the fixed core;
A valve member interlocked with the first movable core that moves to the fixed core side by a suction force generated between the first movable core and the fixed core;
A second movable core provided so as to be relatively movable with the fixed core, and forming the magnetic circuit together with the first movable core and the fixed core;
The fluid pressure generated in the moving region of the second movable core that moves toward the fixed core due to the suction force generated between the second movable core and the fixed core is opposite to the fixed core of the first movable core. An electromagnetically driven valve comprising: an urging means that transmits to a pressure chamber provided on the side and urges the first movable core toward the fixed core by the fluid pressure of the pressure chamber. The first movable core is provided on one end side in the axial direction of the fixed core, and constitutes a first suction part together with the fixed core,
2. The electromagnetically driven valve according to claim 1, wherein the second movable core is provided on the other end side in the axial direction of the fixed core and constitutes a second suction portion together with the fixed core. The fixed core includes a first fixed core provided on a radially inner side of the coil, and a second fixed core provided on a radially outer side of the coil,
The first movable core constitutes a first suction part together with the first fixed core,
2. The electromagnetically driven valve according to claim 1, wherein the second movable core constitutes a second suction portion together with the second fixed core.   2. The urging means includes a tube member that passes through the fixed core and the first movable core in the axial direction and guides a fluid in a moving region of the second movable core to the pressure chamber. Or the electromagnetically driven valve of 2.   3. The electromagnetic wave according to claim 1, wherein the biasing unit guides the fluid in the moving region of the second movable core to the pressure chamber through a communication passage provided on the radially outer side of the coil. Drive valve.   The biasing means includes an upper through hole that communicates with the fixed core in the axial direction, a lower through hole that is provided coaxially with the upper through hole and communicates with the first movable core in the axial direction, and the fixing of the second movable core. 3. The electromagnetically driven valve according to claim 1, further comprising a piston extending from an outer wall on the core side and inserted into the upper through hole and the lower through hole. A coil that generates a magnetic field when energized,
A fixed core provided in a magnetic field generated by the coil;
A first movable core provided so as to be movable relative to the fixed core and forming a magnetic circuit together with the fixed core;
A valve member that moves together with the first movable core that moves toward the fixed core by a suction force generated between the first movable core and the fixed core;
A second movable core provided so as to be relatively movable with the fixed core, and forming the magnetic circuit together with the first movable core and the fixed core;
A fluid pressure generated in a moving region of the second movable core that moves toward the fixed core by a suction force generated between the second movable core and the fixed core is provided on the opposite side of the moving direction of the valve member. An electromagnetically driven valve comprising: a second urging unit that transmits to the second pressure chamber and urges the valve member in the moving direction by the fluid pressure of the second pressure chamber.   The second urging means includes a pressurizing chamber provided inside the valve member, a communication passage communicating the pressurizing chamber and the second pressure chamber inside the valve member, and the second movable core. The electromagnetically driven valve according to claim 7, further comprising: a shaft member that extends in an axial direction from an outer wall of the fixed core side of the shaft and is inserted into the pressurizing chamber. A fuel injection device using the electromagnetically driven valve according to any one of claims 1 to 8,
A fuel passage to which fuel is supplied and a valve body having a valve seat provided on the upstream side of an injection hole for injecting fuel flowing through the fuel passage to the outside air;
The valve member provided inside the valve body opens the fuel passage by separating from the valve seat when the coil is energized,
The fuel injection device, wherein when the energization of the coil is interrupted, the fuel passage is closed by being seated on the valve seat.

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