JP2003343382A - Solenoid valve and fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein an armature of a solenoid valve, a high hardness part having excellent abrasion-resistance and a low hardness part having an excellent magnetic characteristic are press-fitted/fixed, a press-fit burr is generated at a starting end of the press-fit and a removal work of the press-fit burr requires enormous labor and cost. <P>SOLUTION: The high hardness part 32 is constituted by a head part 34, a press-fit part 35 press-fitted into a press-fit hole 33; and a slide-contact shaft 37 supported to a cylinder. The head part 34 is made to a slightly smaller diameter than the press-fit hole 33 and an annular gap α is formed between the head part 34 and the press-fit hole 33. A starting end β of press-fit is set at the inner side than an opening end of the press-fit hole 33. According to this constitution, the press-fit burr generated at the time of press-fitting is confined in a depth of a narrow annular gap α. Therefore, the removal work of the press-fit burr requiring the enormous labor conventionally is unecessary and the cost is inhibited. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve and a fuel injection valve using the solenoid valve.

[0002]

2. Description of the Related Art An armature of a solenoid valve has a portion which is slidably supported by a supporting component and a portion which is greatly affected by the electromagnetic force of a solenoid. Therefore, the part that is slidably supported by the support part is formed of a high hardness part to prevent wear, and the part that is greatly affected by the electromagnetic force of the solenoid is formed of a low hardness part having excellent magnetic characteristics. There is known a technique of integrating by a fixing technique such as press fitting or welding (Japanese Patent Laid-Open No. 10-122082, Japanese Patent Laid-Open No. 5-13).
3296 publication).

[0003]

When the press-fitting technique is adopted as a technique for fixing a high-hardness component and a low-hardness component, the press-fitting surface of the low-hardness component is scraped off by the high-hardness component at the time of press-fitting, and the press-fitting start end is pressed. Burrs occur. If the solenoid valve is used without removing the press-fit burr, the press-fit burr may fall off and enter the movable part (for example, the sliding clearance between the high hardness component and the cylinder), resulting in malfunction. In particular, many fuel injection valves using solenoid valves have an air gap of several tens to several hundreds of μm and a sliding clearance of several to several tens of μm. The fuel injection valve malfunctions by being caught in the air gap that regulates valve performance or the sliding clearance related to solenoid valve behavior (change in opening / closing timing, opening / closing failure, etc.)
May occur. For this reason, it is necessary to remove the press-fitting burr before incorporating the armature into the solenoid valve, but it requires a great deal of labor and cost to remove the press-fitting burr and to control the presence or absence of the press-fitting burr. This is a factor of increasing the cost of the injection valve.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. An object of the present invention is to eliminate the work of removing press-fitting burrs generated during press-fitting and to prevent the press-fitting burrs from falling off. In the provision of injection valves.

[0005]

Means for Solving the Problems [Means for Claims 1 and 2]
By adopting the means of claims 1 and 2, a head portion is provided on the insertion start side of the high hardness component, an annular gap is formed between the head portion and the press fitting hole, and the press fitting start end of the high hardness component is formed. Since it is provided inside the opening end of the press-fitting hole, the press-fitting burr generated at the press-fitting start end during press-fitting is housed in the inner part of the annular gap, and the press-fitting burr can be prevented from falling off. In this way, it is possible to prevent the press-fit burr from falling off without removing the generated press-fit burr.
It becomes unnecessary to remove the press-fitting burrs and to control the presence / absence of the press-fitting burrs, which conventionally required a great deal of labor, and it is possible to suppress the cost increase of the solenoid valve and the fuel injection valve.

[Means of Claim 3] By adopting the means of Claim 3, the head portion is provided with a diameter slightly smaller than the press-fitting hole, and an annular gap is provided between the head portion provided with the small diameter and the press-fitting hole. You may provide so that it may be formed.

[Means of claim 4] By adopting the means of claim 4, the head is provided with a taper surface having a smaller diameter from the press-fitting start end toward the insertion start end, and between the taper surface and the press-fitting hole. It may be provided so as to form an annular gap. By being provided in this way, it is possible to suppress the occurrence of burrs during press fitting.

[Means of Claim 5] By adopting the means of Claim 5, the head is provided with a spherical surface which is continuous with the press-fitting start end, and an annular gap is formed between the spherical surface and the press-fitting hole. May be provided as follows. By being provided in this way, it is possible to suppress the occurrence of burrs during press fitting.

[Means of Claim 6] The means for claim 6 may be adopted to provide a burr sealing groove on the head. With this arrangement, even if the press-fit burr may fall off, the fallen press-fit burr is confined in the burr sealing groove, so the drop-out press-fit burr can cause the solenoid valve or fuel injection valve to drop. There is no malfunction that causes malfunction.

[Means of Claim 7] By adopting the means of Claim 7, a low-hardness component may be provided with a burr sealing lid. By providing in this way, even if the press-fitting burr may fall off, the dropped press-fitting burr is confined in the annular gap by the burr sealing lid,
There is no problem that the solenoid valve or fuel injection valve malfunctions due to the press-fitted burr that has fallen off.

[Means of Claim 8] By employing the means of Claim 8, a sealing lid is provided which is press-fitted and fixed in a press-fitting hole from a side different from that of the high-hardness component to enclose burr in an annular gap. May be. Even if the press-fitting burr may fall off due to the provision in this way, the fallen press-fitting burr is confined in the annular gap by the sealing lid. There is no problem that the injection valve malfunctions.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described using a plurality of examples and modifications. [First Embodiment] An embodiment will be described with reference to FIGS.
First, the main part of the fuel injection valve will be described with reference to FIG.

The fuel injection valve is used, for example, in a pressure-accumulation type fuel injection device for a diesel engine, and injects high-pressure fuel supplied from a common rail (not shown) into an engine combustion chamber, and inside a nozzle (not shown). The needle placed in the vertical direction (valve opening direction or valve closing direction)
A solenoid valve 1 for displacing the solenoid valve is provided. The nozzle (not shown) includes a nozzle body (not shown) fastened to the lower end of the main body 2 by a retaining nut (not shown), and a needle (not shown) slidably inserted into the nozzle body. The nozzles formed at the tip of the nozzle body are opened and closed by the vertical displacement of the needle.

In the main body 2, a sliding contact hole 4 into which the control piston 3 is inserted, a first high pressure fuel passage (not shown) for guiding high pressure fuel supplied from the common rail to the nozzle side, and high pressure fuel in an orifice plate 5. A second high-pressure fuel passage 7 that leads to the formed pressure control chamber 6, a low-pressure fuel passage 8 that guides low-pressure fuel to the movable portion of the solenoid valve 1, a discharge passage 9 that discharges high-pressure fuel to the low-pressure side, and the like are formed. .

The control piston 3 is slidably inserted in the sliding contact hole 4 of the main body 2, and the pressure control chamber 6
When the pressure control chamber 6 is at a high pressure, the needle is seated on the nozzle body to close the injection hole when the pressure is high, and when the pressure control chamber 6 is at a low pressure, it is displaced upward by the upward force applied to the needle. The needle is separated from the nozzle body to open the injection hole.

The orifice plate 5 is a stack of two plates and is arranged on the end face of the main body 2 which opens at the upper end of the sliding contact hole 4 and has a pressure control chamber 6 communicating with the sliding contact hole 4. Has been formed. The orifice plate 5 may be provided as a single plate. The orifice plate 5 has orifices (an inlet orifice 11 and an outlet orifice 12) formed on the upstream side and the downstream side of the pressure control chamber 6, respectively. The inlet orifice 11 communicates with the second high-pressure fuel passage 7 to which high-pressure fuel is supplied, and the outlet orifice 12 is formed above the pressure control chamber 6, and the pressure control chamber 6 and the discharge passage 9 (low-pressure side). ) Is provided to communicate with.

The solenoid valve 1 controls the pressure control chamber 6 to be switched between low pressure and high pressure by opening and closing the outlet orifice 12, and a ball valve 13 (corresponding to an opening and closing valve body) that opens and closes the outlet orifice 12 is provided. The armature 14 attached to the lower end, the cylinder 15 (corresponding to a supporting member) that slidably supports the armature 14 in the vertical direction, the solenoid 16 that drives the armature 14 upward (in the valve opening direction), and the solenoid 16 A push rod 18 supported in a sleeve 17 arranged at the center, and the armature 14 is moved downward (valve closing direction) via the push rod 18.
A spring 19 for urging the solenoid valve 1, a cover 20 for closing the upper portion of the solenoid valve 1 and the like are built in. The orifice plate 5, the cylinder 15, the spacer 21, the solenoid 16 and the cover 20 are sequentially assembled on the upper portion of the main body 2. These are fastened to the upper part of the main body 2 by the body upper 22.

Electromagnetic coil 2 built in the solenoid 16
Both ends of 3 are connected to a connector 25 attached to the upper portion of the cover 20 via lead metal fittings 24 and the like, and when the electromagnetic coil 23 is energized (ON) via this connector 25, the spring 19 The armature 14 moves upward against the urging force of the armature. As a result, the ball valve 13 is lifted upward from the upper surface of the orifice plate 5, and the outlet orifice 12 is opened. When the energization of the electromagnetic coil 23 is stopped (OFF), the armature 14 is pressed downward by the urging force of the spring 19,
The ball valve 13 sits on the upper surface of the orifice plate 5 so as to close the outlet orifice 12.

Next, the operation of the fuel injection valve will be described. The high-pressure fuel supplied from the common rail to the fuel injection valve is introduced into the nozzle (not shown) and the pressure control chamber 6. At this time,
Solenoid valve 1 is OFF (ball valve 13 is outlet orifice 1
2 is closed), the pressure of the high-pressure fuel introduced into the pressure control chamber 6 strongly pushes down the control piston 3, so that the needle does not lift and closes the injection hole, so fuel is not injected.

When the solenoid valve 1 is turned on, the ball valve 13 opens the outlet orifice 12 and the outlet orifice 12 communicates with the discharge passage 9, so that the pressure in the pressure control chamber 6 decreases.
When the pressure in the pressure control chamber 6 drops to a predetermined valve opening pressure,
The pressure of the high-pressure fuel supplied into the nozzle increases the force that pushes up the needle, lifts the needle, opens the injection hole, and starts fuel injection.

After that, when the solenoid valve 1 is turned off, the ball valve 13 closes the outlet orifice 12, and the pressure control chamber 6 again.
Fuel pressure rises. Then, when the pressure of the pressure control chamber 6 rises to a predetermined valve closing pressure, the force of the control piston 3 to push down the needle is increased, the needle is pushed down to close the injection hole, and the injection ends.

Next, the essential parts of the solenoid valve 1 to which the present invention is applied will be described. As shown in FIG. 2, the armature 14 includes a low-hardness component 31 (soft iron or the like) having excellent magnetic characteristics that is attracted by the electromagnetic force of the solenoid 16 and a high-hardness component 32 (which is slidably supported by the cylinder 15). Steel, etc.) and is fixed and integrated by press-fitting technology. The low-hardness component 31 has a substantially disc shape and is arranged to face the lower surface of the solenoid 16, and has a high-hardness component 32 in the center.
A press-fitting hole 33 having a circular cross section is formed so as to press-fit. The high-hardness component 32 has a rod shape with a circular cross section, and has a head portion 34 formed slightly smaller in diameter than the press-fitting hole 33 and a diameter slightly larger than the press-fitting hole 33 from the upper side to the lower side in the drawing. And a sliding contact shaft 37 slidably supported in a sliding contact hole 36 formed in the center of the cylinder 15.

The head portion 34 is formed with a cylindrical side surface having a diameter slightly smaller than that of the press-fitting hole 33. The head portion 34 and the press-fitting hole 33 are formed.
An annular gap α is formed between and. Further, by forming the head portion 34 on the side surface of the cylinder having a diameter slightly smaller than that of the press-fitting hole 33,
The press-fitting start end β (upper end of the press-fitting portion 35 in the drawing) of the high hardness component 32 is set inside the opening end of the press-fitting hole 33 (below the upper opening end in the drawing).

In assembling and manufacturing the solenoid valve 1, when the high hardness part 32 is press-fitted into the press-fitting hole 33 of the low hardness part 31, the inner surface of the press-fitting hole 33 is scraped off by the high hardness part 32 to form the press-fitting start end β. Press-fit burr occurs. However,
As described above, since the narrow annular gap α is formed between the head portion 34 and the press-fitting hole 33 and the press-fitting start end β of the high hardness component 32 is provided inside the press-fitting hole 33, the generated press-fitting burr is generated. Is a narrow annular gap α formed by press-fitting work.
Is contained in the back of the.

On the other hand, the movable space 38 of the armature 14 is
It communicates with the low-pressure fuel passage 8 through a communication passage 39 formed in the cylinder 15, a communication passage 40 formed in the orifice plate 5, and a communication passage 41 formed in the cylinder 15. This is because the movable space 38 is filled with fuel,
This is a configuration for keeping the lift characteristic of the armature 14 constant. For example, even if the movable space 38 is configured to contain only air, fuel will eventually enter the movable space 38 through the sliding clearance between the high hardness component 32 and the cylinder 15. Then, air and fuel are mixed in the movable space 38. Comparing the case where the air and the fuel are mixed with each other and the case where only the air is used in the movable space 38, the attraction characteristic of the solenoid 16 of the armature 14 changes because the resistance when the armature 14 is attracted changes. , Both (when mixed and when only air) are different. As a result, the lift characteristic of the solenoid valve 1 when the solenoid valve 1 is energized may change, which in turn may change the injection characteristic of the fuel injection valve when the solenoid valve 1 is energized.

Therefore, in the solenoid valve 1 of the fuel injection valve of this embodiment, the movable space 38 is always filled with the fuel.
The movable space 38 and the low pressure fuel passage 8 are communicated with each other. Then, in the movable space 38 having such a configuration, the armature 1
If the press-fitting burr remains attached during the press-fitting of No. 4, the press-fitting burr is caused to flow by the fuel, and the flown press-fitting burr may reach the movable portion (for example, the sliding clearance between the high hardness component 32 and the cylinder 15). is there.

However, as described above, in this embodiment, the press-fitting burr is enclosed in the narrow annular gap α formed by the press-fitting operation for manufacturing the armature 14. Therefore, the press-fit burr is prevented from being exposed by the fuel in the movable space 38. Therefore, it becomes unnecessary to remove the press-fitting burrs and to control the presence / absence of the press-fitting burrs, which has required a lot of labor in the past, and it is possible to suppress the cost increase of the fuel injection valve. That is, the press-fitting hole 3 is inserted into the high hardness component 32.
By the inexpensive means of forming the head portion 34 having a diameter smaller than 3, and providing the press-fitting start end β inside the press-fitting hole 33, it is possible to manage the work of removing the press-fitting burr and the presence or absence of the press-fitting burr, which requires a great deal of labor. It can be made unnecessary, and the cost can be suppressed as compared with the conventional case where deburring is required.

[Second Embodiment] A second embodiment will be described with reference to FIG. In this embodiment, on the side surface of the head portion 34, the tapered surface 3 having a smaller diameter from the press-fitting start end β toward the insertion start end.
4a is provided. By providing in this way, the high hardness component 3 is placed inside the press-fitting hole 33 of the low hardness component 31.
When press-fitting 2, the press-fitting burr is suppressed because the press-fitting burr is pressed while the inner surface of the press-fitting hole 33 is pressed against the tapered surface 34a. Since the generation of the press-fitting burr is suppressed in this manner, the possibility that the press-fitting burr will fall off can be further reduced in addition to the first embodiment, and the reliability of the fuel injection valve can be improved.

[Third Embodiment] A third embodiment will be described with reference to FIG. In this embodiment, the head portion 34 is provided in a semi-spherical shape, and the connecting portion between the head portion 34 and the press-fitting start end β also has the spherical surface 3.
4b is provided. By providing in this way, the high hardness component 3 is placed inside the press-fitting hole 33 of the low hardness component 31.
At the time of press-fitting 2, the press-fitting burr is suppressed as in the second embodiment because the inner surface of the press-fitting hole 33 is press-fitted in a state of being pressed against the spherical surface 34b, and the same effect as the second embodiment is obtained. be able to.

[Fourth Embodiment] A fourth embodiment will be described with reference to FIG. In this embodiment, the head 34 is provided with a burr sealing groove 34c for sealing the press-fitting burr in the annular gap α, and the upper end of the head 34 has a small gap with the press-fitting hole 33. It is provided (gap fitting). By providing the burr sealing groove 34c in this way, even if the press-fitting burr generated during press-fitting may fall off, the dropped press-fitting burr is trapped in the burr-sealing groove 34c and therefore falls off. The problem that the fuel injection valve malfunctions due to the press-fitting burr is avoided.

[Fifth Embodiment] A fifth embodiment will be described with reference to FIG. In this embodiment, a deburring lid 33a for enclosing a press-fitting burr is provided at the opening end portion of the press-fitting hole 33, and a gap is fitted between the deburring lid 33a and the head 34. By providing the burr sealing lid 33a in this way, even if the press-fitting burr generated at the time of press-fitting may fall off, the dropped press-fitting burr is confined in the annular gap α by the burr blocking lid 33a. Therefore, it is possible to avoid a problem that the fuel injection valve malfunctions due to the press-fitted burr that has fallen off.

[Sixth Embodiment] A sixth embodiment will be described with reference to FIG. In this embodiment, a sealing lid 42 which is press-fitted and fixed in the press-fitting hole 33 is provided from a side different from the high hardness component 32, and the burr is sealed in the annular gap α by the sealing lid 42. You can Therefore, even if the press-fitting burr generated during the press-fitting may fall off, the fallen press-fitting burr is confined in the annular gap α by the sealing lid 42, so that the drop-out press-fitting burr causes the fuel injection valve. This avoids a malfunction that causes a malfunction. In FIG. 7, the head portion 34 (small diameter portion for burr sealing)
However, the head 34 may be provided integrally with the sealing lid 42.

[Modification] In the above embodiment, an example in which the present invention is applied to the solenoid valve 1 of the fuel injection valve has been shown, but not limited to the fuel injection valve, the armature 14 is a low hardness component 31 having excellent magnetic characteristics. The present invention may be applied to all solenoid valves that press-fit and fix the high hardness component 32 having excellent wear resistance.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a fuel injection valve.

FIG. 2 is a sectional view of an essential part of an armature (first embodiment).

FIG. 3 is a sectional view of an essential part of an armature (second embodiment).

FIG. 4 is a sectional view of an essential part of an armature (third embodiment).

FIG. 5 is a sectional view of an essential part of an armature (fourth embodiment).

FIG. 6 is a sectional view of a main part of an armature (fifth embodiment).

FIG. 7 is a sectional view of an essential part of an armature (sixth embodiment).

[Explanation of symbols]

1 Solenoid valve 5 Orifice plate 6 Pressure control room 11 Inlet orifice 12 Exit orifice 13 Ball valve (open / close valve body) 14 Armature 15 cylinders (support members) 16 solenoid 31 Low hardness parts 32 High hardness parts 33 Press fit hole 33a Burr sealing lid 34 head 34a Tapered surface 34b spherical surface 34c Burr sealing groove 35 Press-fitting section 42 sealing lid α annular gap β press fit start end

Claims (8)

[Claims] 1. An electromagnetic valve, comprising an armature slidably supported by a support member and movable by an electromagnetic force of a solenoid, wherein the armature has magnetic characteristics attracted by the electromagnetic force of the solenoid. The press-fitting portion of a high-hardness component that is slidably supported by the support member and has excellent wear resistance is press-fitted and fixed inside the press-fitting hole formed in the excellent low-hardness component. A head for forming an annular gap between the press-fitting hole and the press-fitting hole is provided, and the press-fitting start end of the high-hardness component is provided inside the opening end of the press-fitting hole. solenoid valve. 2. A high pressure fuel is supplied through an inlet orifice, and an orifice plate that forms a pressure control chamber that communicates with the low pressure side through an outlet orifice, a solenoid that generates an electromagnetic force by energization, and a sliding member are used for sliding. An armature that is freely supported and movable by the electromagnetic force of the solenoid, and an electromagnetic valve that is provided at the end of the armature and that has an opening / closing valve body that opens and closes the outlet orifice, and a fuel valve that controls the fuel pressure in the pressure control chamber. Is a fuel injection valve having a nozzle that displaces by itself, and a nozzle that opens and closes an injection hole by the needle, wherein the armature is a low hardness component excellent in magnetic characteristics attracted by the electromagnetic force of the solenoid. Inside the formed press-fitting hole, there is a press-fitting part of a high-hardness component that is slidably supported by the support member and has excellent wear resistance. It is one that is inserted and fixed, the head that forms an annular gap between the press-fitting hole and the insertion start side of the press-fitting hole is provided, and the press-fitting start end of the high-hardness component is the press-fitting hole. A fuel injection valve, which is provided inside the opening end. 3. The solenoid valve according to claim 1 or the fuel injection valve according to claim 2, wherein the head portion has a diameter slightly smaller than that of the press-fitting hole. 4. The electromagnetic valve according to claim 1, or the fuel injection valve according to claim 2, wherein the head portion is provided with a tapered surface whose diameter decreases from the press-fitting start end toward the insertion start end. Valve or fuel injection valve. 5. The solenoid valve according to claim 1, or the fuel injection valve according to claim 2, wherein the head portion has a spherical surface continuous with the press-fitting start end. 6. The solenoid valve according to claim 1 or the fuel injection valve according to claim 2, wherein the head portion is provided with a burr sealing groove for sealing burr in the annular gap. Or a fuel injection valve. 7. The solenoid valve or the fuel injection valve according to claim 1, wherein the low hardness component includes a burr sealing lid for sealing a burr in the annular gap. Solenoid valve or fuel injection valve. 8. The solenoid valve or the fuel injection valve according to claim 1, wherein the armature is press-fitted and fixed in the press-fitting hole from a side different from that of the high-hardness component, and the armature is provided in the annular gap. A solenoid valve or a fuel injection valve, characterized in that it is provided with a sealing lid for containing burrs.