JP2002256342A - Method for manufacturing composite magnetic material, and method for manufacturing pole piece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a composite magnetic material having excellent product yield and productivity and a method for manufacturing a pole piece. SOLUTION: In the method for manufacturing the composite magnetic material 14 having a ferromagnetic part and a nonmagnetic part or a weak-magnetic part, a composite magnetic material 10 is formed using ferromagnetic stainless steel, heat treatment is applied to the entire composite magnetic material 10 to form the whole of the material into nonmagnetic or weak-magnetic austenitic phase, and then quenching treatment is applied to the desired part of the composite magnetic material 11 to form the quenched part into the ferromagnetic part 12 composed of martensitic phase and also form the unquenched part into the nonmagnetic part or weak-magnetic part 13.

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 composite magnetic material and a method of manufacturing a pole piece, and more particularly to a method of manufacturing a pole piece of an eddy current reduction device for a retarder that applies deceleration braking to a vehicle. .

[0002]

2. Description of the Related Art Generally, when a vehicle goes down a long hill or the like,
A deceleration braking device (retarder) is used to reduce the acceleration that occurs in the vehicle, apply stable and continuous deceleration braking to the vehicle, and prevent burnout of the foot brake, which is the main brake, as one of the retarders. There is an eddy current type reduction gear.

As shown in FIG. 11, an eddy current type speed reducer 1
One of the ten constituent members is a pole piece (composite magnetic material) provided between a rotor 112 mounted coaxially with the rotation shaft 111 and magnet bodies 113 and 114 provided facing the inner peripheral surface of the rotor 112. Material) 115. The pole piece 115 here is a cylindrical member having a ferromagnetic portion and a non-magnetic portion (or a weak magnetic portion) alternately in a circumferential direction (or an axial direction).

As shown in FIGS. 10 (a) and 10 (b), a conventional method of manufacturing a pole piece 101 is a method of manufacturing a part of a cylindrical member 100 made of ferromagnetic stainless steel, specifically, a cylindrical member. The circumferential direction or the axial direction of the member 100 (FIG. 10B)
(In the circumferential direction), at a predetermined interval, with a partial solution treatment (for example, about 10 to 60 at a temperature of 1100 to 1200 ° C.).
The solution-treated portion is a non-magnetic portion (the portion having the lowest relative magnetic permeability in the stainless steel) 102, and the non-solution-treated portion is a ferromagnetic portion 103.

[0005]

By the way, in the conventional manufacturing method, the non-magnetic portion 102 is formed by subjecting a part of the cylindrical member 100 to a high-temperature solution treatment.
Since the thermal strain of the pole piece 101 after the heat treatment is only in the vicinity of the heat-treated portion (the non-magnetic portion 102) and becomes non-uniform throughout, the difference in the amount of thermal strain increases. was there. For this reason, the amount of correction and the amount of cutting by the subsequent machining process become large, and the product yield and productivity of the pole piece 101 are deteriorated, and the product cost is increased.

An object of the present invention, which has been made in view of the above circumstances, is to provide a method of manufacturing a composite magnetic material and a method of manufacturing a pole piece having good product yield and productivity.

[0007]

In order to achieve the above object, a method of manufacturing a composite magnetic material according to the present invention comprises forming a composite magnetic material from ferromagnetic stainless steel, and then subjecting the entire composite magnetic material to heat treatment. The whole is made to be a non-magnetic or weakly magnetic austenitic phase, and then a desired portion of the composite magnetic material is subjected to a quenching process, the quenched portion is a ferromagnetic portion composed of a martensite phase, and the non-quenched portion is a non-magnetic portion. Alternatively, it is a weak magnetic portion.

On the other hand, the method of manufacturing a pole piece according to the present invention comprises forming a cylindrical member from ferromagnetic stainless steel,
The entire cylindrical member is subjected to a heat treatment to make the whole a nonmagnetic or weakly magnetic austenitic phase, and then subjected to a quenching treatment at predetermined intervals in a circumferential direction or an axial direction of the cylindrical member,
The quenched portion is a ferromagnetic portion composed of a martensite phase, and the non-quenched portion is a non-magnetic portion or a weak magnetic portion. Further, in the method of manufacturing a pole piece according to the present invention, after a plate member is formed of ferromagnetic stainless steel, the entire plate member is subjected to a heat treatment to make the whole a nonmagnetic or weakly magnetic austenitic phase. A quenching process is performed at predetermined intervals in the longitudinal direction or the horizontal direction of the member, the quenched portion is a ferromagnetic portion composed of a martensite phase, the non-quenched portion is a non-magnetic portion or a weak magnetic portion, and thereafter, The plate member is rolled in a vertical or horizontal direction to form a cylindrical member.

According to the above-mentioned method, since the high-temperature solution treatment is applied to the whole of the composite magnetic material, the cylindrical member, or the plate member, the heat of the composite magnetic material, the cylindrical member, or the plate member after the solution treatment is obtained. The distortion is uniform throughout, and the difference in the amount of thermal distortion is small.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described.

FIG. 1 is a schematic view of a method for manufacturing a composite magnetic material according to the first embodiment.

As shown in FIG. 1, in the method of manufacturing a composite magnetic material 14 according to the present embodiment, a composite magnetic material 10 is formed from ferromagnetic stainless steel, and then the entire composite magnetic material 10 is heat-treated (solution). To a non-magnetic or weakly magnetic austenitic phase, and thereafter, a desired portion A of the composite magnetic material 11 is subjected to a quenching process, and the quenched portion is converted to a ferromagnetic portion 12 composed of a martensite phase. The non-quenched part, that is, the other part is a non-magnetic part (or a weak magnetic part) 13
It is assumed that. In the non-magnetic portion (or weak magnetic portion) 13, the non-magnetic portion is mostly austenitic, and the main phase of the weak magnetic portion is austenitic.

Here, the solution treatment is performed in the range of 1100 to 120
It is to be heated and held at a temperature of 0 ° C. for 10 to 60 minutes,
Within this condition range, the heating temperature and the holding time are appropriately selected according to the chemical composition of the stainless steel. Also,
In the quenching treatment, the material is heated to a temperature of about 850 ° C. and then rapidly cooled.

[0014] The cooling rate after the solution treatment is the same as that of the composite magnetic material 1.
No particular limitation is imposed as long as the speed at which the whole 1 becomes a nonmagnetic or weakly magnetic austenitic phase is not particularly limited, and air cooling is generally used.

The stainless steel constituting the composite magnetic material 10 is not particularly limited as long as it is ferromagnetic at room temperature and is transformed into a nonmagnetic or weakly magnetic austenitic phase by solution treatment. For example, ferritic stainless steel, martensitic stainless steel and the like can be mentioned.

As described above, the method of manufacturing the composite magnetic material 14 according to the present invention is based on the method of manufacturing the composite magnetic material
Non-magnetic (or weak-magnetic) by applying solution treatment to the whole
After that, only the desired portion A is subjected to a quenching treatment to ferromagnetically make the portion 12 ferromagnetic. Since the thermal strain caused by the solution treatment occurs in the entire composite magnetic material 11, the composite magnetic material 1
There is almost no possibility that a partial thermal distortion will occur in 1. Also,
Since the temperature and time of the quenching treatment are lower and shorter than those of the solution treatment, the heat distortion accompanying the quenching treatment is very small. Therefore, according to the present invention, since the size and shape of the composite magnetic material 10 before the solution treatment and the composite magnetic material 14 after the quenching treatment are substantially the same, it is possible to obtain a product having a final shape or a shape close thereto. it can.

Next, another embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a cross-sectional view of a method of manufacturing a pole piece according to a second embodiment, and FIG. 2 is a vertical cross-sectional view of an eddy current reduction device using the pole piece obtained by the method of the present embodiment. As shown in FIG. In FIG. 3, the same members as those in FIG. 11 are denoted by the same reference numerals.

First, as shown in FIG. 2A, a cylindrical member 20 is formed of ferromagnetic stainless steel. This cylindrical member 20 is subjected to a solution treatment, so that the whole is 1100-1200.
Heat and hold at a temperature of 10 ° C. for 10 to 60 minutes, then cool. Thereby, as shown in FIG. 2 (b), the cylindrical member 2 entirely made of a nonmagnetic or weak magnetic austenitic phase.
It becomes 1. At this point, the thermal strain generated by the solution treatment is removed by machining or the like, and the cylindrical member 21 is corrected to a perfect circle.

Next, as shown in FIG. 2C, the magnet body shown in FIG. 11 extends in the circumferential direction or axial direction of the cylindrical member 21 (the circumferential direction in FIG. 2C). 113,1
The hardening treatment is performed at a temperature of about 850 ° C. at a predetermined interval so as to face the magnetic pole surface (the upper surface in FIG. 11) of the magnetic recording medium, and a plurality of circumferentially extending magnetic heads (12 in FIG. Pieces)
Is formed (returned) in the ferromagnetic portion 22 composed of a martensite phase, and the non-quenched portion between the ferromagnetic portions 22 is defined as a non-magnetic portion (or a weak magnetic portion) 23.

Thereafter, the quenched cylindrical member 21 is appropriately subjected to low-temperature tempering to obtain a pole piece 24. At this time, in the low-temperature tempering treatment, the tempering temperature and the tempering time are appropriately selected according to the chemical composition of the stainless steel constituting the cylindrical member 20.

It goes without saying that the pole piece 24 obtained by the manufacturing method of the present embodiment can be applied to the conventional eddy current type speed reducer 110 shown in FIG.
In particular, the retarder (eddy current type speed reducer) 30 of the circumferential single row type (only one row of the magnet bodies 113 is arranged in the long axis direction (the horizontal direction in FIG. 3) of the rotating shaft 111) shown in FIG. It is valid.

In the conventional manufacturing method shown in FIG. 10, a heat treatment for partially maintaining the cylindrical member 100 at a high temperature for a long time, that is, a partial solution treatment is performed, so that a laser or an electron beam is used as a heating source. It must be used, and the heat treatment process is complicated and costly as compared with the heat treatment using a heating furnace or the like. In addition, cylindrical member 1
Since the heat treatment is partially applied to the heat treatment 00, the heat distortion of the pole piece 101 after the heat treatment becomes non-uniform only in the vicinity of the heat treatment part, that is, over the whole, and therefore, the difference in the distortion amount of the heat distortion becomes large. As a result, the product yield and productivity of the pole piece 101 were not so good.

On the other hand, in the manufacturing method of the present embodiment, a heat treatment of putting the entire cylindrical member 20 in a heating furnace and keeping it at a high temperature for a long time, that is, a solution treatment is performed. Compared with the partial solution treatment in the conventional production method, the heat treatment step is easier and the cost is lower. Further, since the solution treatment is performed on the entire cylindrical member 20, the thermal strain of the cylindrical member 21 after the solution treatment becomes uniform over the whole, and therefore, the difference in the distortion amount of the thermal strain is reduced. As a result, since the amount of cutting by machining is small, the product yield and productivity of the pole piece 24 are improved, and the product cost can be reduced.

The temperature and time of the quenching process for forming the ferromagnetic portion 22 are lower and shorter than those of the solution treatment performed on the entire cylindrical member 20, so that the pole piece 24 after the quenching process is performed. Is smaller than the thermal strain of the cylindrical member 21 after the solution treatment. Thereby, the pole piece 2 after the quenching process is performed.
There is no need to make a mechanical correction to 4.

Further, as shown in FIGS. 4 to 6, the non-magnetic portion 23 (the cylindrical member 2) of the pole piece 24 after the quenching process is performed.
No. 1 non-quenched portion) is machined on the outer peripheral surface (upper surface in FIG. 4), inner peripheral surface (lower surface in FIG. 5), or both surfaces (upper and lower surfaces in FIG. 6). The recesses 40, 50, and 60 may be formed, and the thickness of the nonmagnetic portion 23 may be formed smaller than that of the ferromagnetic portion 22. As a result, the weight of the pole piece 24 can be reduced, and the weight of the eddy current reduction device can be reduced.

When forming the concave portion 40 shown in FIG. 4 (or the concave portion 50 shown in FIG. 5 or the concave portion 60 shown in FIG. 6), as shown in FIG. ,
Alternatively, a concave portion 80 having a step portion 81 may be formed as shown in FIG. Thereby, the nonmagnetic portion 23 does not remain on the outermost peripheral surface portion (or the innermost peripheral surface portion, the outermost peripheral surface portion and / or the innermost peripheral surface portion) of the pole piece 24.
Thereby, the magnet body (113, 11 in FIG. 11)
The magnetic flux from 4) effectively acts on the rotor via the ferromagnetic portion 22.

Further, when forming the recess 40 shown in FIG. 4, as shown in FIG.
When 2) rotates in the direction indicated by arrow B, the ferromagnetic portion 22
(In FIG. 9, both ends in the left-right direction) 22a,
Steps 91 and 92 are provided on the downstream side and the upstream side in the rotation direction so that the rotation direction 22b is inclined toward the downstream side in the rotation direction (the left side in FIG. 9).
May be formed. Thereby, the magnetic flux from the magnet body (113, 114 in FIG. 11)
The ferromagnetic portion 22 acts on the rotor in a state of being narrowed down to the downstream end 22a in the rotation direction, so that the braking torque can be further increased.

As described above, the embodiment of the present invention is not limited to the above-described embodiment, and it goes without saying that various other embodiments can be envisaged.

[0030]

In summary, according to the present invention, the following excellent effects are exhibited. (1) By performing a high-temperature heat treatment on the entire composite magnetic material, the heat distortion of the composite magnetic material after the heat treatment is uniform throughout, and the difference in the amount of thermal distortion is small. (2) As a result of (1), the product yield and productivity of the composite magnetic material are improved, and the product cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic view illustrating a method for manufacturing a composite magnetic material according to a first embodiment.

FIG. 2 is a cross-sectional view illustrating a method of manufacturing a pole piece according to a second embodiment.

FIG. 3 is a longitudinal sectional view of an eddy current reduction device using a pole piece obtained by a manufacturing method according to a second embodiment.

FIG. 4 is a partially enlarged view showing an example of a concave portion formed in a non-magnetic portion.

FIG. 5 is a partially enlarged view showing an example of a concave portion formed in a non-magnetic portion.

FIG. 6 is a partially enlarged view showing an example of a concave portion formed in a non-magnetic portion.

FIG. 7 is a partially enlarged view showing an example of a concave portion formed in a non-magnetic portion.

FIG. 8 is a partially enlarged view showing an example of a concave portion formed in a non-magnetic portion.

FIG. 9 is a partially enlarged view showing an example of a concave portion formed in a non-magnetic portion.

FIG. 10 is a cross-sectional view showing a conventional method of manufacturing a pole piece.

FIG. 11 is a longitudinal sectional view of the eddy current reduction device.

[Explanation of symbols]

 10, 11, 14 Composite magnetic material 12, 22 Ferromagnetic part 13, 23 Nonmagnetic part (nonmagnetic part or weak magnetic part) 20, 21 Cylindrical member 24 Pole piece 40, 50, 60, 70, 80, 90 Concave part 71 , 81, 91, 92 Step (recess)

Claims (8)

[Claims] 1. A method of manufacturing a composite magnetic material having a ferromagnetic part and a non-magnetic part or a weak magnetic part, comprising: forming a composite magnetic material from ferromagnetic stainless steel; The whole is a nonmagnetic or weak magnetic austenitic phase, and then a quenching process is performed on a desired portion of the composite magnetic material, the quenched portion is a ferromagnetic portion composed of a martensite phase, and the non-quenched portion is a nonmagnetic portion or A method for producing a composite magnetic material, comprising a weak magnetic portion. 2. The heat treatment according to claim 1, wherein the heat treatment is performed at a temperature of 1100 to 1200 ° C. for 10 to 60 minutes.
A method for producing the composite magnetic material as described above. 3. The method for producing a composite magnetic material according to claim 1, wherein the quenching treatment is performed at a temperature of about 850 ° C. 4. A method for manufacturing a pole piece, which is used in an eddy current reduction device and has a ferromagnetic part and a non-magnetic part or a weak magnetic part alternately, after forming a cylindrical member from ferromagnetic stainless steel, The entire member is subjected to a heat treatment to make the whole a non-magnetic or weakly magnetic austenitic phase, and then subjected to a quenching treatment at predetermined intervals in a circumferential direction or an axial direction of the cylindrical member, and the quenched portion comprises a martensite phase. A method for manufacturing a pole piece, wherein a non-quenched part is a non-magnetic part or a weak magnetic part in a ferromagnetic part. 5. A method for manufacturing a pole piece, which is used in an eddy current reduction device and has a ferromagnetic portion and a non-magnetic portion or a weak magnetic portion alternately, after forming a plate member from ferromagnetic stainless steel, The entire member is subjected to a heat treatment to make the whole a non-magnetic or weakly magnetic austenitic phase, and thereafter, a quenching treatment is performed at predetermined intervals in the longitudinal direction or the lateral direction of the plate member, and the quenched portion comprises a martensite phase. In the ferromagnetic part, the non-quenched part is a non-magnetic part or a weak magnetic part,
Thereafter, the plate member is rolled in a vertical direction or a horizontal direction to form a cylindrical member. 6. The heat treatment according to claim 4, wherein the heat treatment is performed at a temperature of 1100 to 1200 ° C. for 10 to 60 minutes.
Or the manufacturing method of the pole piece of 5. 7. The method of manufacturing a pole piece according to claim 4, wherein the quenching treatment is performed at a temperature of about 850 ° C. 8. The method of manufacturing a pole piece according to claim 4, wherein after the quenching process, a concave portion is formed on the outer peripheral surface, the inner peripheral surface, or both surfaces of the non-quenched portion of the cylindrical member.