JP2000046224A - Manufacture of disc type solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure stability of magnetic properties (magnetic property and nonmagnetic property), to improve magnetic characteristics through reduction of a leakage magnetic flux, and to perform the increase of the attraction force of an electromagnetic coil, improvement of responsiveness, and the decrease of a manufacturing cost. SOLUTION: In a core part 21 formed of a magnetic substance, paying an attention to a fact that the core part is divided into a part (an inside magnetic substance part 22 and an outside magnetic substance part 23) effecting welding with a cover 4 and a part (an upper magnetic substance part 24) to be assembled, and after welding with the cover 4 is effected, heat treatment (solution treatment of the cover 4 and tempering of magnetic substances 22 and 23) is executed, and the core part 21 is divided into the inside magnetic substance part 22, the outside magnetic substance part 23, and the upper magnetic substance part 24. After the cover 4 formed of a nonmagnetic substance is assembled between the inside magnetic substance part 22 and the outside magnetic part 23 and welded to each other, heat treatment is applied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a disk-type solenoid valve, and more particularly to a method of manufacturing a disk-type solenoid valve used as a fuel injector or other actuator.

[0002]

2. Description of the Related Art Conventionally, a solenoid valve (electromagnetic valve) has been generally used as an actuator for a fuel injection injector in an internal combustion engine. Recently, as an injector, it is required that high-pressure fuel can be injected for in-cylinder direct injection for directly injecting fuel into a cylinder, and therefore, a disk-type solenoid valve capable of setting a large suction force is used. There are cases. For example, there is JP-A-8-49624.

[0003] A conventional disk-type solenoid valve 1 will be outlined with reference to FIGS. 4 and 5. FIG. 4 is a cross-sectional view of a main part of the disk-type solenoid valve 1.
A valve housing 2, an electromagnetic coil 3, a cover 4,
A disk type armature 5, a valve spring 6,
Having.

[0004] The valve housing 2 is formed by a core portion 7 made of a magnetic material and a lower valve housing 8. The core 7 is formed by press-fitting a fuel supply pipe 9 into an upper valve housing 10 to form an integral structure.
In the core section 7, the electromagnetic coil 3 is housed in the annular coil housing section 11 from the side of the disk-type armature 5, which is formed between the fuel supply pipe 9 and the upper valve housing 10.

The electromagnetic coil 3 is capable of attracting the disk-type armature 5 by the excitation thereof, and lifts a needle valve (not shown) fixed to the tip (the lower side in the figure) of the disk-type armature 5 to form a nozzle hole (not shown). (Not shown).

The cover 4 is formed in a ring shape from a non-magnetic material, and is fixed to the core 7 by welding with a laser beam or the like so that the coil housing 11 can be closed. In addition to ensuring oil tightness to prevent intrusion, magnetic flux leakage is prevented.
If an O-ring or the like is used instead of the cover 4, it is difficult to ensure oil tightness by high-pressure injection, and the cost increases.

FIG. 5 is a flow chart showing the outline of a method of manufacturing the disk-type solenoid valve 1. The core 7 in which the fuel supply pipe 9 is press-fitted into the upper valve housing 10 is first subjected to "rough processing" and then to "rough processing". "Precision processing" after "magnetic annealing" (heat treatment). Also, the cover 4 is subjected to "solution processing" (heat treatment) after "rough processing" and then "precision processing", and after assembling these parts and welding as described above, "covering" or the like is performed. Finish processing,
The disk type armature 5, the valve spring 6, the lower valve housing 8, and the like are assembled.

The above-mentioned “magnetic annealing” is performed by heating the core 7 to a predetermined temperature (for example, 850 ° C.) and then gradually cooling the core 7.
In the “solution treatment”, the cover 4 is heated to a predetermined temperature (for example, 1050 ° C.), then rapidly cooled, and the cover 4 is cooled at the time of fabrication. It removes magnetism. For the parts that need to ensure oil tightness, such as the core 7 and the cover 4,
Since it is affected by the thermal strain after heat treatment (magnetic annealing and solution treatment), it is necessary to precisely process this after heat treatment. Inevitably worsens.

However, if the laser beam output is increased to increase the welding strength between the core 7 and the cover 4 in order to ensure oil tightness under high-pressure fuel, the welding temperature is generally reduced in this welding process. Since the melting point of iron exceeds 1536 ° C., an excessive heat load acts on the core 7 and the cover 4,
This causes a problem that the magnetic properties of the core 7 and the non-magnetic properties of the cover 4 deteriorate. Specifically, there are problems such as a decrease in attractive force of the electromagnetic coil 3 and a decrease in responsiveness due to magnetic flux leakage and deterioration of magnetic properties. It should be noted that a solenoid valve having deteriorated characteristics usually has to be discarded, and has a problem that the production yield is poor.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and is intended to manufacture a disk-type solenoid valve capable of ensuring the stability of magnetic characteristics (magnetic characteristics and non-magnetic characteristics). It is an object to provide a method.

Another object of the present invention is to provide a method of manufacturing a disk-type solenoid valve capable of increasing the attraction force of an electromagnetic coil and improving responsiveness by reducing leakage magnetic flux and improving magnetic characteristics. As an issue.

Another object of the present invention is to provide a method of manufacturing a disk-type solenoid valve which can reduce the manufacturing cost by reducing the number of component processing steps.

[0013]

That is, the present invention divides a core portion made of a magnetic material into a portion to be welded to a cover made of a non-magnetic material and a portion to be assembled later. After welding with the cover,
Heat treatment such as solution treatment of the cover and annealing of the core portion is performed, and since the heating temperature of the solution treatment is higher than the heating temperature of the annealing, the cover and the core portion are integrated and the cover is Focusing on the fact that even if the core part is annealed after the solution treatment, the thermal influence on each other can be ignored, etc., and the core part made of a magnetic material and the electromagnetic coil provided in the coil housing part of this core part Coils and
A method for manufacturing a disk-type solenoid valve, comprising: a cover made of a non-magnetic material and welded to the core to allow the coil housing to be closed; and a disk-type armature capable of attracting the electromagnetic coil. And the core
An inner magnetic body (fuel supply pipe), an outer magnetic body (valve housing), and an upper magnetic body are divided, and the cover is interposed between the inner magnetic body and the outer magnetic body. A method of manufacturing a disk-type solenoid valve, comprising performing heat treatment after assembling and welding.

The heat treatment may be a solution treatment of the cover and an annealing of the inner magnetic body portion and the outer magnetic body portion.

After the heat treatment, the electromagnetic coil and the upper magnetic body can be assembled.

In the method of manufacturing the disk type solenoid valve according to the present invention, the core (the inner magnetic body and the outer magnetic body) and the cover are assembled and welded, and then each heat treatment, specifically, the cover is performed. Solution annealing and core annealing treatment, and the core annealing temperature is lower than the heat treatment temperature of the solution treatment of the cover, so there is no thermal effect on each of them. In this case, the magnetic properties can be improved by correcting the adverse effect of the thermal load on the cover and the core part at the time.

Further, since the processing steps after the heat treatment can be omitted, the production cost can be reduced.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a method of manufacturing a disk type solenoid valve according to the present invention will be described with reference to FIGS.
However, the same parts as those in FIGS. 4 and 5 are denoted by the same reference numerals, and detailed description thereof will be omitted. FIG. 1 is a cross-sectional view of a main part of the disk-type electromagnetic valve 20. In the disk-type electromagnetic valve 20, a core 21 corresponding to the core 7 of the disk-type electromagnetic valve 1 (FIG. Fuel supply pipe 9
The inner magnetic body part 22 and the outer magnetic body part 2 corresponding to (FIG. 4)
3, and the upper magnetic body portion 24. That is, in addition to the inner magnetic body portion 22 corresponding to the fuel supply pipe 9 (FIG. 4), the upper valve housing 10 of the core portion 7 includes the outer magnetic body portion 23 and the upper magnetic body portion 24 as components. , Is divided. This core part 21
And the lower valve housing 8 constitute a valve housing 25.

The inner magnetic member 22 is located on the inner peripheral side of the electromagnetic coil 3. The outer magnetic body portion 23 includes the electromagnetic coil 3
The electromagnetic coil 3 and the cover 4 are disposed on the outer peripheral side of the inner magnetic body portion 22 on the outer peripheral side. The upper magnetic part 24 includes
The coil housing 11 is located above the electromagnetic coil 3 in the figure (upstream side opposite to the disk type armature 5).
A coil housing 26 corresponding to (FIG. 4) can be opened upward.

A method of manufacturing the disk-type solenoid valve 20 will be described with reference to FIG. FIG. 2 is a flowchart schematically showing a method of manufacturing the disk-type solenoid valve 20, and includes an inner magnetic body portion 22.
Then, the outer magnetic body portion 23 is "precisely machined", the cover 4 is "precisely machined", and "assembled / welded". By this welding, the inner magnetic body part 22, the outer magnetic body part 23 and the cover 4 are integrated, and the coil housing part 26 is formed. Next, "heat treatment" is performed. Specifically, the cover 4
, And then “magnetic annealing” of the inner magnetic body portion 22 and the outer magnetic body portion 23 is performed.

FIG. 3 is a graph showing the steps of this heat treatment. First, a solution treatment of the cover 4 is performed. Processing temperature of 1000 to 1200 ° C., preferably 1010 to 1150
After performing the treatment at 0.5 ° C. for 0.5 to 2 hours, preferably 1 to 2 hours, quenching is performed with water or the like. In this solution treatment, rapid cooling is performed, so it is considered that there is no influence on the inner magnetic body portion 22 and the outer magnetic body portion 23. Next, magnetic annealing of the inner magnetic body portion 22 and the outer magnetic body portion 23 is performed. Processing temperature 800-900 ° C, preferably 85
After the treatment is performed at 0 ° C. for 1 to 2 hours, preferably 1.5 hours, slow cooling is performed by air cooling. In this magnetic annealing, the processing temperature is lower than that of the solution treatment.
It is considered that there is no effect on the part.

In this way, adverse effects on magnetic properties due to heat load due to processing and welding are removed for both the cover 4, the inner magnetic body part 22 and the outer magnetic body part 23, and the respective magnetic properties (the non-magnetic Characteristics, magnetic characteristics of the inner magnetic body portion 22 and the outer magnetic body portion 23) can be stabilized.

On the other hand, the upper magnetic portion 24 is subjected to “magnetic annealing” after “precision processing”, and the heat treatment of the cover 4, the inner magnetic portion 22, and the outer magnetic portion 23 is performed as described above. After assembling the electromagnetic coil 3 into the coil accommodating portion 26 from above in the drawing, the upper magnetic body portion 24 is "assembled" (press-fitted), and finally "finishing" such as surface facing.

Thus, according to the present invention, by changing the order of the welding process such as laser welding and the solution treatment of the cover 4 which is a non-magnetic material, it is possible to avoid the characteristic change due to the welding of the solution cover 4 in particular. So,
Deterioration of magnetic properties due to the thermal load due to conventional welding can be avoided, and stable and good magnetic properties can be obtained. Further, in the conventional disk-type solenoid valve 1 (FIG. 4), since the parts are affected by thermal distortion after the heat treatment, the parts for securing oil tightness (the core part 7 and the cover 4) are precision processed after the heat treatment. However, in the present invention, since the heat treatment is performed after the assembly, the precision processing step can be omitted. Note that the upper magnetic body portion 24 does not require much accuracy, so that precision machining after magnetic annealing can be omitted. Furthermore, in the conventional method,
Normally, the solenoid valve whose characteristics are deteriorated has to be discarded. However, in the present invention, precision processing and welding are performed on the core portion (the inner magnetic body portion 22 and the outer magnetic body portion 23) and the cover 4. Since the process has been completed, it is possible to improve the magnetic properties by performing the heat treatment again.

[0025]

As described above, according to the present invention, heat treatment is performed after assembling the cover (non-magnetic portion), the inner magnetic portion, and the outer magnetic portion, so that stable magnetic characteristics can be obtained. Thus, a disk-type solenoid valve suitable for high-pressure injection can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a disk-type solenoid valve 20 for explaining a method of manufacturing a disk-type solenoid valve according to the present invention.

FIG. 2 is a flowchart schematically showing a method of manufacturing the disk-type solenoid valve 20.

FIG. 3 Same heat treatment (solution treatment and magnetic annealing)
3 is a graph showing a step.

FIG. 4 is a sectional view of a main part of a conventional disk-type solenoid valve 1.

FIG. 5 is a flowchart schematically showing a method of manufacturing the disk-type solenoid valve 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disc type solenoid valve (FIG. 4) 2 Valve housing 3 Electromagnetic coil 4 Cover (non-magnetic part) 5 Disk type armature 6 Valve spring 7 Core part (magnetic part) 8 Lower valve housing 9 Fuel supply pipe 10 Upper valve housing DESCRIPTION OF SYMBOLS 11 Coil accommodation part 20 Disk type solenoid valve (FIG. 1) 21 Core part (magnetic body part) 22 Inner magnetic body part 23 Outer magnetic body part 24 Upper magnetic body part 25 Valve housing 26 Coil accommodation part

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G066 AB02 AD12 BA19 BA54 BA61 CC06U CC14 CD04 CD21 CD28 CE22 CE23 CE24 CE25 CE26 3H106 DA07 DA13 DA23 DB02 DB12 DB26 DB32 DC04 DC06 EE04 EE16 EE35 GA03 GA10 GA11 GA13 GA25 KK18 5E048 AB07

Claims (1)

[Claims] 1. A core portion made of a magnetic material, an electromagnetic coil provided in a coil housing portion of the core portion, and a coil member made of a non-magnetic material which can be welded to the core portion to close the coil housing portion. And a disk type armature provided with a disk type armature capable of attracting the electromagnetic coil, wherein the core portion includes an inner magnetic body portion, an outer magnetic body portion, and an upper magnetic body. And a heat treatment after assembling and welding the cover between the inner magnetic body portion and the outer magnetic body portion.