JP2008267377A - Solenoid valve and fuel injection valve having same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solenoid valve excellent in response of a valve member when electricity supply to a coil is turned off and a fuel injection valve having the same. <P>SOLUTION: A first magnetic cylindrical member 14 covers an outer circumference of a movable core 26, and a second magnetic cylindrical member 18 covers an outer circumference of a fixed core 30. The first magnetic cylindrical member 14 and the second magnetic cylindrical member 18 form a magnetic circuit with the movable core 26 and the fixed core 30. A non-magnetic cylindrical member 16 covers an outer circumference of a gap 200 formed between the movable core 26 and the fixed core 30, and prevents short of magnetic flux between the first magnetic cylindrical member 14 and the second magnetic cylindrical member 18. Thickness t of the non magnetic cylindrical member 16, cross section area S1 of the fixed core 30 of a section covered by the non-magnetic cylindrical member 16, sum S2 of section areas of the fixed core 30 and the second magnetic cylindrical member 18 at the non magnetic cylindrical member 16 side in an axial direction, satisfy 0.15 mm ≤ t ≤0.6 mm and 0.55≤ (S1/S2) ≤0.9. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a solenoid valve and a fuel injection valve using the same.

A fuel injection valve that interrupts fuel injection using an electromagnetic valve that generates a magnetic attractive force between the fixed core and the movable core by energizing the coil and opens and closes the fluid passage by a valve member that reciprocates with the movable core. It is known (see, for example, Patent Document 1).
In Patent Document 1, a magnetic diaphragm is provided between a movable core side magnetic part and a fixed core side magnetic part that cover the outer periphery of the movable core, and the movable core side magnetic part, the fixed core side magnetic part, and the magnetic diaphragm are one piece. The whole structure which consists of a part is formed. In Patent Document 1, this magnetic aperture reduces the short circuit of the magnetic circuit between the movable core side magnetic part and the fixed core side magnetic part when energization of the coil is turned on, and the movable core sandwiches the gap. Magnetic attractive force is generated between the core and the fixed core.

However, when the magnetic diaphragm is formed of a magnetic material as in Patent Document 1, it is possible to reduce a short circuit of the magnetic circuit between the movable core side magnetic part and the fixed core side magnetic part, but magnetic flux leaks to the magnetic diaphragm. The magnetic attractive force acting between the movable core and the fixed core is reduced.
Therefore, in place of the magnetic diaphragm made of a magnetic material, a non-magnetic portion that covers the outer periphery of the gap between the movable core and the fixed core is provided between the movable core-side magnetic portion and the fixed core-side magnetic portion. It is conceivable to prevent a magnetic short circuit between the part and the fixed core side magnetic part.

  However, in the configuration in which the outer periphery of the gap is covered with the nonmagnetic portion formed of a nonmagnetic material in this way to prevent a magnetic short circuit between the movable core side magnetic portion and the fixed core side magnetic portion, the coil is energized. When turned off, an eddy current is generated in the nonmagnetic portion due to a rapid decrease in the magnetic flux flowing through the gap. When an eddy current is generated in the nonmagnetic part covering the outer periphery of the gap, magnetic flux is induced in the magnetic part near the gap, so that the disappearance of the magnetic attractive force acting between the fixed core and the movable core is delayed. As a result, there is a problem that the responsiveness of the valve member of the solenoid valve is lowered when the power supply to the coil is turned off.

Japanese National Patent Publication No. 11-500509

  The present invention has been made to solve the above problems, and an object of the present invention is to provide an electromagnetic valve excellent in responsiveness of a valve member when energization of a coil is turned off, and a fuel injection valve using the same.

  In the first to seventh aspects of the invention, the thickness of the non-magnetic cylindrical portion covering the outer periphery of the gap between the magnetic facing portion and the movable core is t, the cross-sectional area of the magnetic facing portion is S1, and the magnetic facing portion When the sum of the cross-sectional area and the cross-sectional area of the cylindrical member having the plate thickness t holding the magnetic facing portion is S2, t ≦ 0.6 mm.

  By defining the upper limit of the thickness of the non-magnetic cylinder part covering the outer periphery of the gap with t ≦ 0.6 mm and reducing the thickness of the non-magnetic cylinder part as much as possible, the volume of the non-magnetic cylinder part is reduced. Thereby, the eddy current which generate | occur | produces in a nonmagnetic cylinder part when the electricity supply to a coil is turned off reduces. As a result, when the power to the coil is turned off, the magnetic flux that passes through the gap and flows between the magnetic facing portion and the movable core quickly disappears, and the magnetic attractive force that acts between the magnetic facing portion and the movable core is quickly Since it falls, the responsiveness of the valve member when the power supply to the coil is turned off is improved.

  Here, when the sum S2 of the cross-sectional area of the magnetic facing portion and the cross-sectional area of the cylindrical member having the plate thickness t holding the magnetic facing portion becomes larger than the cross-sectional area S1 of the magnetic facing portion, (S1 / S2) The value becomes smaller. When the cross-sectional area S2 increases, the electromagnetic energy held by the magnetic facing portion and the second magnetic cylinder portion increases when the magnetic flux flows through the magnetic facing portion and the second magnetic cylinder portion. As a result, the disappearance of the magnetic flux flowing between the magnetic facing portion and the movable core is delayed when the energization of the coil is turned off, so that the magnetic attractive force acting between the magnetic facing portion and the movable core does not quickly decrease, so the coil The responsiveness of the valve member is lowered when the energization to is turned off.

  Therefore, in the invention described in claims 1 to 3, it is assumed that 0.55 ≦ (S1 / S2), and the cross-sectional area of the magnetic facing portion and the plate thickness t holding the magnetic facing portion with respect to the cross-sectional area S1 of the magnetic facing portion. By defining the upper limit of the sum S2 of the cross-sectional area and the cross-sectional area of the cylindrical member, the electromagnetic energy held in the magnetic facing portion and the second magnetic cylinder portion is minimized. Thereby, when the power supply to the coil is turned off, the magnetic flux flowing between the magnetic facing portion and the movable core disappears quickly, and the magnetic attractive force acting between the magnetic facing portion and the movable core is quickly reduced. As a result, the responsiveness of the valve member is lowered when the power supply to the coil is turned off.

Here, in order to reduce generation | occurrence | production of an eddy current, it is desirable that the thickness of a nonmagnetic cylinder part is as thin as possible. However, if the thickness is too thin, there is a problem that the mechanical strength of the non-magnetic cylinder portion is lowered.
Therefore, in the invention according to claim 2, the coil t is turned off by setting the lower limit value of the thickness of the non-magnetic cylinder portion by setting the thickness t of the non-magnetic cylinder portion to 0.15 mm ≦ t ≦ 0.6 mm. In addition, the eddy current generated in the nonmagnetic tube portion is reduced and the mechanical strength of the nonmagnetic tube portion is ensured.

  By the way, when the outer diameter of the second magnetic cylinder portion is reduced, the cross-sectional area S2 formed by the outer peripheral surface of the second magnetic cylinder portion is reduced and (S1 / S2) is increased. When the outer diameter of the second magnetic cylinder portion becomes smaller and smaller than the outer diameter of the nonmagnetic cylinder portion, a gap is formed between the inner peripheral surface of the coil that covers the outer periphery of the nonmagnetic cylinder portion and the outer peripheral surface of the second magnetic cylinder portion. Is formed and becomes a magnetic resistance, the magnetic attractive force acting between the magnetic facing portion and the movable core is reduced.

  Therefore, in the third aspect of the present invention, 0.55 ≦ (S1 / S2) ≦ 0.90 is set, and the second is set with respect to the outer diameter of the magnetic facing portion whose outer periphery is covered with the nonmagnetic cylindrical portion. By setting the upper limit of the outer diameter of the magnetic cylindrical portion, the magnetic flux flowing through the magnetic facing portion and the second magnetic cylindrical portion disappears quickly, and the magnetic attractive force acting between the magnetic facing portion and the movable core is reduced. It is preventing.

In the inventions according to claims 4 to 6, since the concave portion is provided in the nonmagnetic cylindrical portion, the volume of the nonmagnetic cylindrical portion can be reduced as much as possible. By reducing the volume, eddy currents generated in the nonmagnetic cylinder portion are reduced.
In the invention according to claim 7, the outer diameter of the non-magnetic cylinder part and the outer diameters of the first magnetic cylinder part and the second magnetic cylinder part on the non-magnetic cylinder part side are formed substantially equal.

In the invention according to claim 8, the non-magnetic cylinder part, the first magnetic cylinder part and the second magnetic cylinder part are joined by welding. In this way, the non-magnetic cylinder part, the first magnetic cylinder part, and the second magnetic cylinder part are formed as separate members, so that the non-magnetic cylinder part, the first magnetic cylinder part, and the second magnetic cylinder part are configured. The cylindrical member can be formed by combining various materials such as a sintered material, a cutting material, and a cold forging material.
In the invention according to claim 9, the non-magnetic cylinder part, the first magnetic cylinder part, and the second magnetic cylinder part are formed of a composite magnetic material as one member. Thereby, the reliability of preventing leakage of fluid from between the respective cylinder portions is increased. In addition, since the number of parts is reduced, the assembly time of the solenoid valve is reduced.

  By the way, in the fuel injection valve, the fuel injection amount is controlled by adjusting the signal width in a range in which the injection rate characteristic is proportional to the drive signal applied to the coil, for example, the signal width of the pulse signal. However, if the valve closing responsiveness of the fuel injection valve decreases and the time from when the drive signal is turned off until the fuel injection valve closes and the fuel injection is cut off becomes longer, when the signal width of the drive signal is short, Since the injection rate characteristic is not proportional to the signal width of the pulse signal, it becomes difficult to control the fuel injection amount. Therefore, in the conventional fuel injection valve, when the drive signal width to be applied to the coil is short as in idling operation, the drive signal width is increased to inject excessive fuel in order to ensure the required amount of fuel injection. It was. As a result, there is a problem that fuel consumption is reduced.

  Therefore, in the invention described in claim 10, the fuel from the nozzle hole is used by using the electromagnetic valve according to any one of claims 1 to 9 and the valve member seated on the valve seat when the power supply to the coil is turned off. The injection is cut off, and the fuel is injected from the injection hole by separating the valve member from the valve seat when the coil is energized. According to the fuel injection valve having this configuration, the valve closing response is improved when the power to the coil is turned off. Therefore, the signal width of the drive signal applied to the coil and the fuel injection amount are proportional to each other when the injection amount is smaller than before. Can be maintained. Thereby, since the injection amount injected in idle driving | operation etc. can be reduced, a fuel consumption improves.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
1 and 2 show a fuel injection valve according to a first embodiment of the present invention. The fuel injection valve 10 is a fuel injection valve for a gasoline engine. The cylindrical member 12 is formed in the cylindrical shape which consists of a magnetic cylinder member and a nonmagnetic cylinder member. A fuel passage 100 is formed in the tubular member 12, and a valve body 20, a valve member 24, a movable core 26, a spring 28, a fixed core 30 and the like are accommodated in the fuel passage 100.

The cylindrical member 12 has a first magnetic cylinder member 14, a nonmagnetic cylinder member 16, and a second magnetic cylinder member 18 in this order from the lower valve body 20 side in FIG. The first magnetic cylinder member 14, the nonmagnetic cylinder member 16, and the second magnetic cylinder member 18 are integrally coupled to each other by laser welding or the like. The 1st magnetic cylinder member 14, the nonmagnetic cylinder member 16, and the 2nd magnetic cylinder member 18 are the 1st magnetic cylinder part, the nonmagnetic cylinder part, and the 2nd magnetic cylinder part which were respectively described in the claim. The cylindrical member 12 is installed on the inner peripheral side of the coil 44 and covers the outer periphery of the movable core 26 and the fixed core 30.
In the fuel injection valve 10, the first magnetic cylinder member 14, the non-magnetic cylinder member 16, the second magnetic cylinder member 18, the valve member 24, the movable core 26, the spring 28, the fixed core 30, and the coil 44 constitute an electromagnetic valve. Yes.

  The first magnetic cylinder member 14 covers the outer periphery of the movable core 26, and the second magnetic cylinder member 18 covers the outer periphery of the fixed core 30. The first magnetic cylinder member 14 and the second magnetic cylinder member 18 form a magnetic circuit with the movable core 26 and the fixed core 30. The nonmagnetic cylindrical member 16 covers the outer periphery of the gap 200 formed between the movable core 26 and the fixed core 30, and the magnetic flux is short-circuited between the first magnetic cylindrical member 14 and the second magnetic cylindrical member 18. To prevent. The first magnetic cylinder member 14 and the second magnetic cylinder member 18 are made of a magnetic material such as electromagnetic stainless steel, SUS430, or an Fe—Co alloy. The nonmagnetic cylindrical member 16 is made of a nonmagnetic material such as SUS304 or SUS305. The specific resistance values of the first magnetic cylinder member 14, the second magnetic cylinder member 18, and the nonmagnetic cylinder member 16 are preferably 60 μΩ · m or more. Further, as the nonmagnetic cylindrical member 16, a nonmagnetic material metal powder shown in FIG. 3 which is formed by MIM (Metal Injection Molding) and sintered may be used. By sintering after MIM molding, pores 210 are formed in the non-magnetic cylindrical member 16.

The valve body 20 is fixed to the inside of the front end of the first magnetic cylinder member 14 by welding. A nozzle plate 22 having a plurality of nozzle holes is joined to the outer bottom surface of the valve body 20 by welding. The valve body 20 has a valve seat 21 on the inner peripheral wall on which the valve member 24 can be seated.
The valve member 24 is a hollow cylinder with a bottom, and can be seated on the valve seat 21 of the valve body 20. When the valve member 24 is seated on the valve seat 21, the injection hole of the injection hole plate 22 is closed and the fuel injection is shut off. The valve member 24 has a plurality of fuel holes 24a penetrating the side walls. The fuel that has flowed into the valve member 24 passes from the inside to the outside through the fuel hole 24 a and travels toward the valve portion formed by the valve member 24 and the valve seat 21.

The movable core 26 is fixed to the valve body side of the valve member 24 by welding or the like. The spring 28 as a load member applies a load to the movable core 26 and the valve member 24 in the direction in which the valve member 24 is seated on the valve seat 21.
The fixed core 30 as the magnetic facing portion is formed in a cylindrical shape and is accommodated in the cylindrical member 12. The fixed core 30 is installed on the side opposite the valve body with respect to the movable core 26 and faces the movable core 26.

The adjusting pipe 32 is press-fitted into the fixed core 30 and engages one end of the spring 28. By adjusting the press-fitting amount of the adjusting pipe 32, the load of the spring 28 is adjusted.
The magnetic members 40 and 42 are magnetically connected to each other and installed on the outer peripheral side of the coil 44. The magnetic member 40 is magnetically connected to the first magnetic cylinder member 14, and the magnetic member 42 is magnetically connected to the second magnetic cylinder member 18. The fixed core 30, the movable core 26, the first magnetic cylinder member 14, the magnetic members 40 and 42, and the second magnetic cylinder member 18 constitute a magnetic circuit.

The coil 44 is wound around the outer periphery of the spool 46 and covers the outer periphery of the nonmagnetic cylindrical member 16 and the second magnetic cylindrical member 18. The resin housing 50 covers the outer periphery of the cylindrical member 12 and the coil 44. The terminal 52 is electrically connected to the coil 44 and supplies a drive current to the coil 44.
The fuel filter 60 is accommodated on the fuel inlet side of the cylindrical member 12 and removes foreign matters in the fuel flowing into the fuel injection valve 10.

The fuel that has flowed into the fuel passage 100 from above in FIG. 2 of the cylindrical member 12 is a fuel passage in the fixed core 30, a fuel passage in the movable core 26, a fuel passage in the valve member 24, a fuel hole 24 a, and a valve member 24. Is ejected from the nozzle hole of the nozzle hole plate 22 through an opening formed between the valve member 24 and the valve seat 21 when the valve seat 21 is separated from the valve seat 21.
In the fuel injection valve 10 configured as described above, when energization to the coil 44 is turned off, the valve member 24 is moved downward in FIG. The seat 21 is seated, the nozzle hole of the nozzle hole plate 22 is closed, and the fuel injection is shut off.

  When energization of the coil 44 is turned on, magnetic flux flows through the magnetic circuit including the fixed core 30, the movable core 26, the first magnetic cylinder member 14, the magnetic members 40 and 42, and the second magnetic cylinder member 18. A magnetic attractive force is generated between the core 30 and the core 30. Then, the valve member 24 moves together with the movable core 26 toward the fixed core 30 against the load of the spring 28, and the valve member 24 moves away from the valve seat 21. Thereby, fuel is injected from the nozzle hole of the nozzle hole plate 22. The maximum lift amount of the valve member 24 is defined by the movable core 26 being locked to the fixed core 30.

(The sum of the thickness of the nonmagnetic cylindrical member 16, the cross-sectional area of the fixed core 30, and the cross-sectional area of the fixed core 30 and the second magnetic cylindrical member 18)
FIG. 4 shows the elapsed time after turning off the power to the coil 44 when the thickness t of the nonmagnetic cylindrical member 16 is 0.1 mm, 0.2 mm, 0.4 mm, and 0.6 mm, and the movable core. The relationship with the magnetic attraction force which acts between 26 and the fixed core 30 is shown. As can be seen from FIG. 4, when the thickness t of the nonmagnetic cylindrical member 16 is reduced, the magnetic attractive force acting between the movable core 26 and the fixed core 30 is quickly reduced. When the magnetic attraction force acting between the movable core 26 and the fixed core 30 is quickly reduced, the valve member 24 is moved to the valve seat 21 by the load of the spring 28 after the power supply to the coil 44 is turned off as shown in FIG. The valve closing time until the fuel is injected from the nozzle hole is cut off. FIG. 5 shows that when the thickness t of the nonmagnetic cylindrical member 16 exceeds 0.6 mm, there is almost no effect of shortening the valve closing time.

  Therefore, in the first embodiment, the thickness of the nonmagnetic cylindrical member 16 is t, the cross-sectional area of the fixed core 30 at the portion covered by the nonmagnetic cylindrical member 16 is S1, and the nonmagnetic cylindrical member is axially aligned with the fixed core 30. Assuming that the sum of the cross-sectional areas with the 16th second magnetic cylinder member 18 is S2, 0.15 mm ≦ t ≦ 0.6 mm and 0.55 ≦ (S1 / S2) ≦ 0.9 are set.

  By defining the upper limit of the thickness of the nonmagnetic cylindrical member 16 as t ≦ 0.6 mm, the thickness of the nonmagnetic cylindrical member 16 covering the outer periphery of the gap 200 is reduced as much as possible, and the volume of the nonmagnetic cylindrical member 16 is reduced. Therefore, the eddy current generated in the nonmagnetic cylindrical member 16 when the energization to the coil 44 is turned off is reduced. Since the eddy current generated in the nonmagnetic cylindrical member 16 covering the outer periphery of the gap 200 is reduced, the magnetic flux induced by the eddy current in the magnetic material such as the movable core 26 and the fixed core 30 near the gap 200 is reduced. As a result, the magnetic flux that flows between the movable core 26 and the fixed core 30 through the gap 200 when the power supply to the coil 44 is turned off quickly disappears, and the magnetic attraction acting between the movable core 26 and the fixed core 30. The power drops quickly. As a result, the valve closing response of the fuel injection valve 10 when the power supply to the coil 44 is turned off is improved. Moreover, the mechanical strength of the nonmagnetic cylinder member 16 is ensured by setting the lower limit of the thickness t of the nonmagnetic cylinder member 16 by setting the thickness t of the nonmagnetic cylinder member 16 to 0.15 mm ≦ t.

  Here, as described above, the nonmagnetic cylindrical member 16 may be formed by sintering metal powder of a nonmagnetic material after MIM molding. When the nonmagnetic cylindrical member 16 is formed in this manner, the pores 210 are formed inside the nonmagnetic cylindrical member 16, so that the substantial volume of the nonmagnetic cylindrical member 16 is reduced. As a result, it is possible to further reduce the eddy current generated in the nonmagnetic cylindrical member 16 when the power supply to the coil 44 is turned off.

  Further, 0.55 ≦ (S1 / S2) is satisfied, and the sum S2 of the cross-sectional areas of the fixed core 30 and the second magnetic cylinder member 18 is made as small as possible, so that the fixed core 30 and the second magnetic cylinder member 18 are held. The electromagnetic energy is reduced as much as possible. As a result, when the coil 44 is turned off, the magnetic flux flowing between the movable core 26 and the fixed core 30 quickly disappears, and the magnetic attraction force acting between the movable core 26 and the fixed core 30 is quickly generated. descend. As a result, the valve closing response of the fuel injection valve 10 is improved when the coil 44 is turned off.

  Further, by setting (S1 / S2) ≦ 0.90, the outer diameter of the second magnetic cylinder member 18 is prevented from becoming too close to the outer diameter of the fixed core 30. When the outer diameter of the second magnetic cylinder member 18 becomes smaller and approaches the outer diameter of the fixed core 30 to become smaller than the outer diameter of the nonmagnetic cylinder member 16, the gap between the coil 44 and the second magnetic cylinder member 18 becomes larger. Since the resistance of the magnetic circuit is increased, the magnetic attractive force acting between the movable core 26 and the fixed core 30 is reduced.

Therefore, in the first embodiment, 0.55 ≦ (S1 / S2) ≦ 0.90 is set, and the axial direction of the second magnetic cylinder member 18 is closer to the nonmagnetic cylinder member 16 side than the outer diameter of the fixed core 30. By setting the lower limit of the outer diameter, the magnetic flux flowing between the movable core 26 and the fixed core 30 disappears quickly, and the decrease in magnetic attractive force acting between the movable core 26 and the fixed core 30 is prevented. ing.
As described above, in the first embodiment, the valve closing response of the fuel injection valve 10 is improved. Therefore, the signal width of the pulse signal applied to the coil 44 and the fuel injection amount are proportional to each other when the injection amount is smaller than the conventional one. Can be maintained. Thereby, since the injection amount injected in idle operation etc. can be reduced, fuel consumption improves.

  In the first embodiment, the first magnetic cylinder member 14, the nonmagnetic cylinder member 16, and the second magnetic cylinder member 18 constituting the cylindrical member 12 are separate members, and the first magnetic cylinder member 14 and the nonmagnetic cylinder are separate members. The member 16 and the nonmagnetic cylindrical member 16 and the second magnetic cylindrical member 18 are joined by welding. Thus, the 1st magnetic cylinder member 14, the nonmagnetic cylinder member 16, and the 2nd magnetic cylinder member are used by making the 1st magnetic cylinder member 14, the nonmagnetic cylinder member 16, and the 2nd magnetic cylinder member 18 into another member. 18 can be formed by combining various materials such as a sintered material, a cutting material, and a cold forging material.

(Second to fourth embodiments)
Second to fourth embodiments of the present invention are shown in FIGS. In addition, the same code | symbol is attached | subjected to substantially the same component as embodiment mentioned above.
In the second embodiment shown in FIG. 6, an annular recess 72 extending in the axial direction is formed on the outer peripheral side of the nonmagnetic cylindrical member 70.
In the third embodiment shown in FIG. 7, a plurality of annular recesses 82 are formed in the axial direction on the outer peripheral side of the nonmagnetic cylindrical member 80, and the outer periphery of the nonmagnetic cylindrical member 80 is formed in a wave shape.

  By forming the recesses 72 and 82 in this way, in the second and third embodiments, even if the maximum thickness is the same as that of the nonmagnetic cylinder member 16 of the first embodiment, Volume decreases. As a result, since the eddy current generated in the non-magnetic cylindrical members 70 and 80 when the energization to the coil 44 is turned off is reduced, when the energization to the coil 44 is turned off, the movable core 26 and the fixed core 30 The magnetic attractive force acting in between decreases rapidly. Therefore, the valve closing response of the fuel injection valve is improved. When the concave portion is formed in the nonmagnetic cylindrical member as in the second and third embodiments, the maximum thickness is 0.6 mm or less. Further, it is desirable that the minimum thickness is 0.15 mm.

  In the fourth embodiment shown in FIG. 8, the magnetic facing portion 92 that faces the movable core 26, and the first magnetic cylindrical member 14 that is axially opposite to the nonmagnetic cylindrical member 16 are disposed on the outer periphery of the magnetic facing portion 92. The provided second magnetic cylinder portion 94 is formed as one member, and constitutes the fixed core 90. As a result, the number of parts is reduced, and the number of manufacturing steps of the fuel injection valve is reduced.

  Further, in the fourth embodiment, similarly to the first to third embodiments, the thickness of the nonmagnetic cylindrical member 16 is t, and the cross-sectional area of the magnetic facing portion 92 where the nonmagnetic cylindrical member 16 is covered is shown. Is S1, and the sum of the cross-sectional areas of the magnetic facing portion 92 and the second magnetic cylinder portion 94 on the nonmagnetic cylinder member 16 side in the axial direction is S2, 0.15 mm ≦ t ≦ 0.6 mm and 0.55 ≦ ( S1 / S2) ≦ 0.9.

(Other embodiments)
In the above embodiment, the thickness of the nonmagnetic cylinder member is t, the cross-sectional area of the magnetic facing portion of the portion covered by the nonmagnetic cylinder member is S1, and the second magnetic cylinder on the nonmagnetic member side in the axial direction with the magnetic facing portion. When the sum of the cross-sectional areas with the part is S2, 0.15 mm ≦ t ≦ 0.6 mm and 0.55 ≦ (S1 / S2) ≦ 0.9 are set. On the other hand, in the present invention, at least t ≦ 0.6 mm may be set, and in the invention according to claim 1, it is only necessary to set 0.55 ≦ (S1 / S2).

In the said embodiment, the solenoid valve of this invention was used for the fuel injection valve. In addition to this, the present invention may be applied to any solenoid valve as long as the response of the valve member when energization of the coil is turned off is required.
In the said embodiment, the outer diameter of the nonmagnetic cylinder member and the outer diameter of the 1st magnetic cylinder member and the 2nd magnetic cylinder member were made substantially the same. On the other hand, the outer diameters of the first magnetic cylinder member and the second magnetic cylinder member may be different from the outer diameter of the nonmagnetic cylinder member.

Moreover, in the said 1st Embodiment, the 1st magnetic cylinder member 14, the nonmagnetic cylinder member 16, and the 2nd magnetic cylinder member 18 were formed with a separate member, respectively, and were couple | bonded by welding etc. On the other hand, the cylindrical member 12 may be configured as a single member by demagnetizing a portion corresponding to the nonmagnetic cylindrical member of the cylindrical composite magnetic material by quenching or the like. By configuring the cylindrical member 12 as a single member, the reliability of preventing leakage of fuel from between the cylindrical portions constituting the cylindrical member is increased. Further, since the number of parts is reduced, the assembly man-hour for the fuel injection valve is reduced.
In the second and third embodiments, the concave portions 72 and 82 are formed on the outer peripheral side of the nonmagnetic cylindrical members 70 and 80 to reduce the volume of the nonmagnetic cylindrical members 70 and 80. On the other hand, you may form a recessed part in the inner peripheral side of a nonmagnetic cylinder member, and may make the volume of a nonmagnetic cylinder member small.

  As described above, the present invention is not limited to the above-described embodiment, and can be applied to various embodiments without departing from the gist thereof. For example, the characteristic structures of the above-described embodiments are arbitrarily combined. It may be.

Sectional drawing which shows the opposing location of the fixed core and movable core by 1st Embodiment. Sectional drawing which shows the fuel injection valve by 1st Embodiment. The schematic diagram which shows the manufacture example of a nonmagnetic cylinder member. The characteristic view which shows the relationship between the time passage after energization OFF to a coil, and magnetic attraction. The characteristic view which shows the relationship between the thickness of a nonmagnetic member, and valve closing time. Sectional drawing which shows the opposing location of the fixed core and movable core by 2nd Embodiment. Sectional drawing which shows the opposing location of the fixed core and movable core by 3rd Embodiment. Sectional drawing which shows the opposing location of the fixed core and movable core by 4th Embodiment.

Explanation of symbols

  10: fuel injection valve, 12: cylindrical member, 14: first magnetic cylinder member (first magnetic cylinder part), 16, 70, 80: nonmagnetic cylinder member (nonmagnetic cylinder part), 18: second magnetic cylinder Member (second magnetic cylinder part), 20: valve body, 21: valve seat, 24: valve member, 26: movable core, 28: spring (load member), 30, 90: fixed core, 44: coil, 72, 82: concave portion, 92: magnetic facing portion, 94: second magnetic cylinder portion, 200: gap

Claims (10)

A movable core,
A valve member that reciprocates with the movable core to open and close the fluid passage;
A magnetic facing portion facing the movable core on the side opposite to the valve member with respect to the movable core;
A non-magnetic cylindrical portion covering the outer periphery of the gap between the magnetic facing portion and the movable core;
A first magnetic cylinder provided on the movable core side in the axial direction with respect to the non-magnetic cylinder;
A second magnetic cylinder portion provided on an outer periphery of the magnetic facing portion on the opposite side of the first magnetic cylinder portion in the axial direction with respect to the non-magnetic cylinder portion;
A coil that is installed on the outer periphery of the non-magnetic cylindrical portion and generates a magnetic attractive force between the magnetic facing portion and the movable core by being energized;
With
The thickness of the non-magnetic cylindrical portion is t, the cross-sectional area of the magnetic facing portion is S1, and the sum of the cross-sectional area of the magnetic facing portion and the cross-sectional area of the cylindrical member having a plate thickness t holding the magnetic facing portion is S2. Then
An electromagnetic valve, wherein t ≦ 0.6 mm and 0.55 ≦ (S1 / S2).   The solenoid valve according to claim 1, wherein 0.15 mm ≦ t ≦ 0.6 mm.   The solenoid valve according to claim 1, wherein 0.55 ≦ (S1 / S2) ≦ 0.90. A movable core,
A valve member that reciprocates with the movable core to open and close the fluid passage;
A magnetic facing portion facing the movable core on the side opposite to the valve member with respect to the movable core;
A non-magnetic cylindrical portion covering the outer periphery of the gap between the magnetic facing portion and the movable core;
With
A first magnetic cylinder provided on the movable core side in the axial direction with respect to the non-magnetic cylinder;
A second magnetic cylinder portion provided on an outer periphery of the magnetic facing portion on the opposite side of the first magnetic cylinder portion in the axial direction with respect to the non-magnetic cylinder portion;
A coil that is installed on the outer periphery of the non-magnetic cylindrical portion and generates a magnetic attractive force between the magnetic facing portion and the movable core by being energized;
With
The maximum valve thickness of the said nonmagnetic cylinder part shall be 0.6 mm or less, and also the recessed part is provided in the said nonmagnetic cylinder part, The solenoid valve characterized by the above-mentioned.   The solenoid valve according to claim 4, wherein the non-magnetic cylinder part is provided with an annular recess extending in the axial direction on an outer peripheral surface.   The solenoid valve according to claim 4, wherein the outer peripheral surface of the nonmagnetic cylinder portion is formed in a wave shape by providing a plurality of annular recesses in the axial direction thereof.   The outer diameter of the non-magnetic cylinder part and the outer diameter of the first magnetic cylinder part and the second magnetic cylinder part on the non-magnetic cylinder part side are substantially equal to each other. The solenoid valve according to item.   The solenoid valve according to any one of claims 1 to 7, wherein the nonmagnetic cylinder part, the first magnetic cylinder part, and the second magnetic cylinder part are joined by welding.   The nonmagnetic cylinder part, the first magnetic cylinder part, and the second magnetic cylinder part are formed of a composite magnetic material into a single cylindrical member, and the nonmagnetic cylinder part is demagnetized by quenching. The solenoid valve according to claim 1, wherein the solenoid valve is provided. A solenoid valve according to any one of claims 1 to 9;
A valve body having a valve seat on which the valve member is seated on the upstream side of the nozzle hole;
A load member that applies a load to the valve member toward the valve seat;
With
By turning on the current to the coil, the movable core is attracted to the magnetic facing portion against the load of the load member,
The fuel injection from the nozzle hole is cut off when the valve member is seated on the valve seat, and the fuel is injected from the nozzle hole when the valve member is separated from the valve seat. Fuel injection valve.

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