WO2024057621A1 - Magnetic encoder - Google Patents

Magnetic encoder Download PDF

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Publication number
WO2024057621A1
WO2024057621A1 PCT/JP2023/018761 JP2023018761W WO2024057621A1 WO 2024057621 A1 WO2024057621 A1 WO 2024057621A1 JP 2023018761 W JP2023018761 W JP 2023018761W WO 2024057621 A1 WO2024057621 A1 WO 2024057621A1
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WO
WIPO (PCT)
Prior art keywords
magnetic
magnetic encoder
annular
support member
resin
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PCT/JP2023/018761
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French (fr)
Japanese (ja)
Inventor
豊 上願
禎啓 伊藤
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中西金属工業株式会社
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Publication of WO2024057621A1 publication Critical patent/WO2024057621A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
    • F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
    • F16C19/14—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load
    • F16C19/18—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for both radial and axial load with two or more rows of balls
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
    • F16C41/00—Other accessories, e.g. devices integrated in the bearing not relating to the bearing function as such
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
    • G01B7/30—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring angles or tapers; for testing the alignment of axes
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/244—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains
    • G01D5/245—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing characteristics of pulses or pulse trains; generating pulses or pulse trains using a variable number of pulses in a train

Definitions

  • the present invention relates to a magnetic encoder, and particularly to a magnetic encoder that can be applied to a bearing device for supporting a wheel of an automobile.
  • a magnetic encoder that can be applied to a bearing device for supporting a wheel of an automobile is used to detect the rotational speed (number of rotations) of a rotating body that constitutes the bearing device.
  • the rotational speed (number of rotations) of the rotating body is detected by a magnetic sensor provided on the non-rotating body that constitutes the bearing device.
  • a magnetic encoder device is configured by a magnetic encoder and a magnetic sensor.
  • a magnetic encoder generally includes an annular support member that can be attached to a rotating body, and an annular magnet section that is attached to the annular support member and magnetized to have multiple poles in the circumferential direction.
  • the magnet portion includes magnetic powder and a binder, and the binder may be a rubber component or a resin component, and a rubber component is generally used.
  • Patent Document 1 In recent years, from the perspective of improving the detection accuracy of wheel rotation speed, etc., by using a resin component as a binder, the content of magnetic powder in the magnet part has been increased, making it more polarized in the circumferential direction and formed with good dimensional accuracy. A magnet part is being considered (Patent Document 1).
  • Patent Document 1 describes thermoplastic resins such as polyamide 6 (PA6), polyamide 12 (PA12), polyamide 612 (PA612), polyamide 11 (PA11), and polyphenylene sulfide (PPS) as binders constituting the magnet portion of a magnetic encoder. It is described that it is used.
  • PA6 polyamide 6
  • PA12 polyamide 12
  • PA612 polyamide 612
  • PA11 polyamide 11
  • PPS polyphenylene sulfide
  • a magnetic encoder equipped with a magnet portion containing a thermoplastic resin described in Patent Document 1 has a high content of magnetic powder, has good dimensional accuracy, and is considered to have improved magnetic properties compared to conventional ones.
  • the PAs 11 and 12 described in Patent Document 1 may not have sufficient heat resistance. Therefore, depending on the configuration of the wheel support bearing device, for example, heat radiation from the brake disk may cause the wheel to be heated to a temperature close to the melting and softening temperature, and the function of the magnetic encoder may become insufficient.
  • PA6 is not resistant to snow melting agents such as calcium chloride (CaCl 2 ) that are sprayed on roads in winter, so there is a possibility that the magnet part will be damaged. be.
  • snow melting agents such as calcium chloride (CaCl 2 ) that are sprayed on roads in winter
  • thermal shock failure due to decreased flexibility.
  • PPS it is difficult to mix the necessary amount of magnetic powder, so it is difficult to improve the magnetic properties, and there is also a possibility of thermal shock destruction due to a decrease in flexibility.
  • PA612 is relatively poor in toughness, and there is room for improvement in terms of toughness of the magnet portion, thermal shock performance, etc.
  • the present inventor conducted extensive studies in order to solve the above-mentioned problem. As a result, they found that the above-mentioned problems could be solved by using a polycondensate of diamine and biomass-derived sebacic acid as a binder constituting the magnet part of a magnetic encoder.
  • the gist of the present invention is as follows.
  • a first aspect of the present invention includes a circular support member made of a steel plate and a circular resin magnet fixed to the circular support member, and the circular resin magnet includes a polyamide resin binder, magnetic powder, and glass fiber.
  • the polyamide resin binder is a polycondensate of diamine and biomass-derived sebacic acid.
  • the diamine may be an aliphatic diamine having 4 to 12 carbon atoms.
  • An embodiment of the present invention may be a magnetic encoder for a bearing device for supporting a wheel of an automobile.
  • a magnetic encoder that has good magnetic properties, heat resistance, and calcium chloride resistance, and has a lower burden on the natural environment than before.
  • FIG. 1 is a longitudinal sectional view showing an example of a bearing device including a magnetic encoder according to an embodiment of the present invention.
  • FIG. 2 is an enlarged sectional view of a main part of the bearing device shown in FIG. 1.
  • FIG. 1 is a diagram schematically showing a magnetic encoder according to an embodiment of the present invention.
  • a magnetic encoder includes an annular support member made of a steel plate (hereinafter sometimes referred to as a "support member"), and an annular resin magnet (hereinafter referred to as a "resin magnet”) fixed to this annular support member. (sometimes referred to as "resin magnets").
  • the annular resin magnet includes a polyamide resin binder, magnetic powder, and glass fiber.
  • the polyamide resin binder is a polycondensate of diamine and biomass-derived sebacic acid.
  • the resulting polyamide resin which is a polycondensate with diamine, has better magnetic properties and heat resistance than conventional polyamides such as PA6 and PPS, which are used as binders for magnetic encoders. resistant to calcium chloride.
  • sebacic acid since sebacic acid is derived from biomass, it can have a lower environmental impact than conventional binders such as polyamide and PPS that are synthesized only from petroleum-derived raw materials.
  • the annular support member is made of steel plate.
  • materials commonly available in this technical field can be used.
  • Such a material is preferably one that does not impair the magnetic properties of the resin magnet and has appropriate corrosion resistance, such as cold rolled steel plate (SPCC), stainless steel, and the like.
  • the stainless steel include those having magnetism, such as ferritic stainless steel such as SUS430 and martensitic stainless steel such as SUS410.
  • the shape of the support member is annular.
  • a ring-shaped bearing device that can be attached to a rotating body of a bearing device and an inverted L-shaped cross-sectional shape projecting outward, or a cross-sectional shape that is not shown in the drawings, Examples include, but are not limited to, an inverted L-shape that projects inward.
  • the joint surface of the support member with the resin magnet may be subjected to surface treatment, if necessary.
  • Such surface treatment is effective, for example, when bonding a resin magnet and a support member using an adhesive to improve the bonding strength between the support member and the adhesive.
  • Examples of such surface treatments include surface roughening treatment, primer treatment, and the like.
  • Examples of the surface roughening treatment include blasting treatment, chemical etching treatment, chemical conversion treatment, and hairline treatment.
  • the surface roughness Ra when the surface roughening treatment is performed can be, for example, 0.5 to 2 ⁇ m. Surface roughness Ra can be measured based on JIS B0601-1994.
  • primers that can be used for primer treatment include silane primers, phenol primers, and epoxy primers.
  • the polyamide resin binder contained in the annular resin magnet is a polycondensate of diamine and sebacic acid derived from biomass.
  • Biomass-derived sebacic acid is generally a linear dicarboxylic acid having 10 carbon atoms obtained by subjecting castor oil collected from castor seeds to a certain treatment.
  • the diamine component to be polycondensed with biomass-derived sebacic acid is not particularly limited, and examples include aliphatic diamines and aromatic-containing diamines, but aliphatic diamines are preferred from the viewpoint of environmental friendliness and toughness.
  • aliphatic diamines having 4 to 12 carbon atoms are preferred, and aliphatic diamines having 4 to 8 carbon atoms are more preferred.
  • the aliphatic structure constituting the aliphatic diamine may be either linear or branched, but preferably linear.
  • preferable polyamide resin binders containing biomass-derived components include polyamides 410, 610, 1010, and 1210. Such a polyamide resin binder can be obtained by polycondensing biomass-derived sebacic acid and diamine according to a conventional method. Moreover, commercially available products can also be used.
  • the molecular weight of the polyamide resin binder can be appropriately selected in consideration of properties such as strength of the resin magnet, moldability, and the like.
  • a viscosity number can be used as an indicator of molecular weight, and it is possible to select a diamine having a predetermined viscosity number depending on the diamine used.
  • Such a viscosity number (VN value) can be, for example, 125 to 175 ml/g for polyamide 410, and 130 to 170 ml/g for polyamide 610, for example.
  • the viscosity number (VN value) can be measured in accordance with ISO 307.
  • the content of the polyamide resin binder is preferably 5 to 20% by mass in the annular resin magnet.
  • the magnetic powder contained in the annular resin magnet may be any magnetic powder used in the plastic magnet part of commercially available magnetic encoders manufactured by insert molding, such as ferrite magnetic powder such as strontium ferrite and barium ferrite. Powder, rare earth magnetic powder such as neodymium-based or samarium-based powder can be used. Furthermore, in order to improve the magnetic properties of ferrite, lanthanum, cobalt, etc. may be mixed, or a portion of ferrite may be replaced with rare earth magnetic powder such as neodymium-iron-boron, samarium-cobalt, samarium-iron, etc. These magnetic powders may be used alone or in combination of two or more.
  • the content of magnetic powder is preferably 75 to 88% by mass in the annular resin magnet.
  • the glass fiber contained in the annular resin magnet is not particularly limited, but it is preferably finely cut.
  • the content of glass fiber in the annular resin magnet is preferably 3 to 15% by mass.
  • the annular resin magnet may contain other components as necessary.
  • components include organic additives such as carbon fiber, inorganic additives such as glass beads, talc, mica, silicon nitride (ceramic) and crystalline (non-crystalline) silica, and alkyl benzenesulfonates. Amides, toluenesulfonic acid alkyl amides, and hydroxybenzoic acid alkyl esters are included. These may be used alone or in combination of two or more.
  • the support member and the resin magnet may be fixed by a physical structure, may be fixed via an adhesive layer, or may be fixed by a combination of these.
  • adhesives that can constitute the adhesive layer include thermosetting resin adhesives.
  • thermosetting resin adhesives include phenol resin adhesives and epoxy resin adhesives.
  • an adhesive for example, one described in JP-A No. 2016-221952 can be used.
  • the outline of phenolic resin adhesive and epoxy resin adhesive is as follows.
  • phenolic resin adhesive for example, one in which a novolak type phenol resin or resol type phenol resin and a curing agent such as hexamethylenetetramine are dissolved in a solvent such as methanol or methyl ethyl ketone can be used. Furthermore, in order to improve adhesiveness, adhesives in which a novolak type epoxy resin is mixed with these can also be used.
  • Epoxy resin adhesives include adhesives that are one-component epoxy adhesives that can be diluted with a solvent.
  • One-component epoxy adhesives consist of an epoxy resin and a curing agent, and if necessary, other epoxy compounds used as reactive diluents, curing accelerators to improve heat curing speed, heat resistance and curing resistance.
  • Inorganic fillers that have the effect of improving distortion properties, crosslinked rubber fine particles that improve flexibility to deform when stress is applied, etc. may be further added.
  • FIG. 1 is a longitudinal sectional view showing an example of a bearing device equipped with a magnetic encoder according to an embodiment of the present invention.
  • FIG. 2 is an enlarged sectional view of a main part of the bearing device shown in FIG.
  • a bearing device 11 equipped with a magnetic encoder 1 according to an embodiment of the present invention includes an inner ring 12 having an inner ring raceway surface 12A formed on its outer circumferential surface, and an outer ring raceway surface formed on its inner circumferential surface. 13A, and rolling elements 14, 14, etc. that roll between the inner ring raceway surface 12A and the outer ring raceway surface 13A.
  • a fixed magnetic encoder 1 a sensor 10 fixed to an outer ring 13 for detecting rotation of the magnetic encoder 1 facing the magnetic poles of the magnetic encoder 1, and one end and the other end of the bearing in the axial direction. It is equipped with seal members 6, 7, etc. arranged at.
  • a magnetic encoder 1 is attached to an inner ring 12 on the rotating side, and has a resin magnet magnetized in multiple circumferential directions with N and S poles spaced at regular intervals, and a magnetic encoder 1 is attached to an outer ring 13 on the stationary side.
  • the sensor 10 constitutes a rotational speed detection device.
  • FIG. 3 is a diagram schematically showing the magnetic encoder 1 according to the embodiment of the present invention.
  • 3(a) is a diagram schematically showing a cross section of the magnetic encoder 1
  • FIG. 3(b) is a partially cutaway perspective cross-sectional diagram schematically showing a part of the annular shape of the magnetic encoder 1.
  • It is a diagram. It includes an annular support member 2 that can be attached to a rotating body, and an annular resin magnet 3 with a thickness T that is attached to the support member 2 and magnetized to have multiple poles in the circumferential direction. In this embodiment, the support member 2 and the resin magnet 3 are fixed via an adhesive layer 4.
  • the magnetic encoder 1 using the support member 2 having an inverted L-shaped cross section as shown in FIG. 3 can be fitted, for example, to the outer end in the axial direction of the inner ring 12, which is a rotating body, as shown in FIG. .
  • the resin magnet 3 may be attached so as to cover the top surface 5a and outer surface 5b of the projecting portion. Alternatively, it may be further attached so as to cover part or all of the inner surface 5c. Alternatively, it may be attached so as to cover only the upper surface 5a. At this time, each dimension such as the thickness T of the resin magnet 3 is not particularly limited and can be determined as appropriate.
  • Such a magnetic encoder 1 can be obtained by insert molding or the like.
  • insert molding include the method described in JP-A No. 2016-221952.
  • Example 1 Magnetic powder (ferrite magnetic powder), PA410 (polycondensate of tetramethylene diamine and sebacic acid derived from castor oil), and glass fiber were kneaded according to a standard method in the proportions shown in Table 1 to obtain a resin magnet composition for injection molding. Obtained. Using the resin magnet composition, insert molding was performed on a support member in accordance with the method described in Examples of JP-A-2016-221952. The outline is as follows. A thermosetting adhesive (phenolic adhesive) is applied to the part of the supporting member (material: SUS430) 2 having the shape shown in FIG. Then, it was air-dried and solidified.
  • thermosetting adhesive phenolic adhesive
  • a supporting member made of a dried and solidified thermosetting adhesive is installed in a mold and the mold is clamped, and an orienting magnetic field is applied inside the mold by an injection molding machine, and the above-mentioned resin magnet composition in a molten state is applied.
  • the object was injected into a cavity of a predetermined shape, and an annular resin magnet was molded on the joint surface where the adhesive was dried and solidified.
  • the support member and the resin magnet were integrated by heating at a temperature equal to or higher than the crosslinking reaction initiation temperature of the thermosetting adhesive via the cured adhesive. Magnetization was performed using a magnetizing yoke to obtain a magnetic encoder.
  • the thickness T (see symbol T in FIG. 3(a)) of the resin magnet portion was 0.9 mm.
  • Example 2 comparison targets 1 and 2 A magnetic encoder was obtained in the same manner as in Example 1, except that the composition of each component was changed as shown in Table 1.
  • the binder resin used in Example 2 is as follows. ⁇ PA610 Polycondensate of hexamethylene diamine and sebacic acid derived from castor oil
  • the binder resins used in Comparisons 1 and 2 are as follows. ⁇ PA6 Ring-opening polycondensate of ⁇ -caprolactam ⁇ PPS Straight chain type
  • ⁇ Thermal shock performance> Using the magnetic encoders obtained in Examples 1 and 2 and Comparatives 1 and 2, a thermal shock test was conducted using one cycle of holding at -40°C for 30 minutes and holding at 120°C for 30 minutes. The appearance is observed every 100 cycles to check for defects such as cracks, chips, cracks, and changes in shape. If any of these defects occur, the test is terminated at that point and the number of cycles is determined. Recorded. Using the number of cycles of Comparative Example Subject 1 as a reference (100), relative values of the number of cycles in which defects occurred in Examples 1, 2, and Comparative Subject 2 were calculated.
  • ⁇ CaCl resistance 2 test> Using the magnetic encoders obtained in Examples 1 and 2 and Comparisons 1 and 2, a calcium chloride resistance (CaCl 2 ) test was conducted as follows. (1) Leave at 50°C and 95% RH for 24 hours. (2) Apply a 5% by mass aqueous solution of calcium chloride (CaCl 2 ) to the entire surface of the resin magnet using a cotton swab. (3) Leave at room temperature for 30 minutes. (4) 100 Drying at °C for 3 hours (5) Leaving for 20 hours at 50 °C and 95% RH After this, steps (2) to (5) were repeated up to 19 times, and it was visually confirmed whether the resin magnet was damaged.
  • Magnetic flux density Using the magnetic encoders obtained in Examples 1 and 2 and Comparisons 1 and 2, magnetic flux density was measured with a magnet analyzer. Using the measured value of Comparative Subject 1 as a reference (100), relative values of the measured values of Examples 1, 2, and Comparative Subject 2 were calculated.
  • Example 2 which uses PA610 synthesized using biomass-derived raw materials, has significantly better flow characteristics than Comparatives 1 and 2, and also has improved magnetic flux density and thermal shock characteristics. Therefore, a magnetic encoder using PA610 as a resin binder is particularly useful because it has better characteristics than conventional ones and can reduce the burden on the natural environment.
  • the flow characteristics of the resin magnet composition for injection molding used in Examples 1 and 2 are higher than that of Comparison 1, and the magnetic particle orientation rate during magnetic field molding can be improved compared to the conventional one.
  • the target magnetic force can be obtained with a small amount of magnetic particles.
  • the toughness and thermal shock performance of the resin magnet will be further improved.
  • PA610 as the resin binder, the fluidity properties are significantly improved, and further improvements in these properties can be expected.

Abstract

This magnetic encoder has an annular support member made of a steel plate, and an annular resin magnet fixed to the annular support member, wherein: the annular resin magnet includes a polyamide resin binder, magnetic powder, and glass fiber; and the polyamide resin binder is a polycondensate of diamine and biomass-derived sebacic acid. The magnetic encoder has good magnetic properties, heat resistance, and calcium chloride resistance, and can reduce the burden on the natural environment compared to conventional magnetic encoders.

Description

磁気エンコーダmagnetic encoder
　本発明は、磁気エンコーダに関し、特に、自動車のホイール支持用軸受装置に適用可能な磁気エンコーダに関するものである。 The present invention relates to a magnetic encoder, and particularly to a magnetic encoder that can be applied to a bearing device for supporting a wheel of an automobile.
　自動車のホイール支持用軸受装置に適用可能な磁気エンコーダは、当該軸受装置を構成する回転体の回転速度（回転数）を検出するために用いられる。回転体の回転速度（回転数）の検出は、軸受装置を構成する非回転体に設けられている磁気センサにより行われる。磁気エンコーダと磁気センサとにより磁気エンコーダ装置が構成される。磁気エンコーダは、一般に、回転体に取り付け可能な円環状支持部材と、この円環状支持部材に取り付けられ、円周方向に多極に着磁された円環状の磁石部とを備えている。磁石部は、磁性粉とバインダーとを含み、バインダーは、ゴム成分又は樹脂成分が用いられるが、ゴム成分が一般的である。 A magnetic encoder that can be applied to a bearing device for supporting a wheel of an automobile is used to detect the rotational speed (number of rotations) of a rotating body that constitutes the bearing device. The rotational speed (number of rotations) of the rotating body is detected by a magnetic sensor provided on the non-rotating body that constitutes the bearing device. A magnetic encoder device is configured by a magnetic encoder and a magnetic sensor. A magnetic encoder generally includes an annular support member that can be attached to a rotating body, and an annular magnet section that is attached to the annular support member and magnetized to have multiple poles in the circumferential direction. The magnet portion includes magnetic powder and a binder, and the binder may be a rubber component or a resin component, and a rubber component is generally used.
　近年、車輪の回転数の検出精度を向上させる観点等から、バインダーとして樹脂成分を用いることで、磁石部の磁性粉の含有率を増加して円周方向により多極化され、寸法精度よく形成される磁石部が検討されている（特許文献１）。 In recent years, from the perspective of improving the detection accuracy of wheel rotation speed, etc., by using a resin component as a binder, the content of magnetic powder in the magnet part has been increased, making it more polarized in the circumferential direction and formed with good dimensional accuracy. A magnet part is being considered (Patent Document 1).
　特許文献１には、磁気エンコーダの磁石部を構成するバインダーとして熱可塑性樹脂であるポリアミド６（ＰＡ６）、ポリアミド１２（ＰＡ１２）、ポリアミド６１２（ＰＡ６１２）、ポリアミド１１（ＰＡ１１）、ポリフェニレンサルファイド（ＰＰＳ）を用いることが記載されている。 Patent Document 1 describes thermoplastic resins such as polyamide 6 (PA6), polyamide 12 (PA12), polyamide 612 (PA612), polyamide 11 (PA11), and polyphenylene sulfide (PPS) as binders constituting the magnet portion of a magnetic encoder. It is described that it is used.
特許第４４３２７６４号公報Patent No. 4432764
　特許文献１に記載の熱可塑性樹脂を含む磁石部を備える磁気エンコーダは、磁性粉の含量が多く寸法精度が良好で、磁気特性が従来より向上すると考えられる。しかしながら、ブレーキを多用したり、何らかの異常が発生し、ホイール支持用軸受装置が非常に高温になった場合に、特許文献１に記載のＰＡ１１、１２では耐熱性が十分ではない可能性がある。そのため、ホイール支持用軸受装置の構成によっては、例えばブレーキディスクからの放熱により溶融軟化温度に近い温度に加熱され、磁気エンコーダの機能が不十分になる可能性がある。また、ＰＡ６、ＰＰＳは耐熱性の確保は可能であるが、ＰＡ６は、冬季に道路に散布される塩化カルシウム（ＣａＣｌ２）等の融雪剤に対する耐性がないため、磁石部が損傷する可能性がある。また、柔軟性の低下による熱衝撃破壊の可能性もある。ＰＰＳは、磁性粉を必要量混合することが困難なため、磁気特性の向上が困難であり、柔軟性の低下による熱衝撃破壊の可能性もある。ＰＡ６１２は、比較的靭性に劣り、磁石部の靭性、熱衝撃性能等の点で改善の余地がある。 A magnetic encoder equipped with a magnet portion containing a thermoplastic resin described in Patent Document 1 has a high content of magnetic powder, has good dimensional accuracy, and is considered to have improved magnetic properties compared to conventional ones. However, when the wheel supporting bearing device becomes extremely hot due to heavy use of the brakes or some abnormality, the PAs 11 and 12 described in Patent Document 1 may not have sufficient heat resistance. Therefore, depending on the configuration of the wheel support bearing device, for example, heat radiation from the brake disk may cause the wheel to be heated to a temperature close to the melting and softening temperature, and the function of the magnetic encoder may become insufficient. Furthermore, although it is possible to ensure heat resistance with PA6 and PPS, PA6 is not resistant to snow melting agents such as calcium chloride (CaCl 2 ) that are sprayed on roads in winter, so there is a possibility that the magnet part will be damaged. be. There is also the possibility of thermal shock failure due to decreased flexibility. In PPS, it is difficult to mix the necessary amount of magnetic powder, so it is difficult to improve the magnetic properties, and there is also a possibility of thermal shock destruction due to a decrease in flexibility. PA612 is relatively poor in toughness, and there is room for improvement in terms of toughness of the magnet portion, thermal shock performance, etc.
　また、近年では、国連持続可能な開発サミットで採択された持続可能な開発目標の一環として、自然環境への負担軽減も、自動車部品に対して求められるようになっている。 Additionally, in recent years, as part of the Sustainable Development Goals adopted at the United Nations Sustainable Development Summit, automobile parts have been required to reduce their burden on the natural environment.
　そこで、本発明の目的は、磁気特性、耐熱性及び塩化カルシウム耐性が良好で、自然環境への負担が従来より軽減された磁気エンコーダを提供することにある。 Therefore, it is an object of the present invention to provide a magnetic encoder that has good magnetic properties, heat resistance, and calcium chloride resistance, and has a reduced burden on the natural environment compared to conventional magnetic encoders.
　本発明者は、前述の課題解決のために、鋭意検討を行った。その結果、磁気エンコーダの磁石部を構成するバインダーとして、ジアミンとバイオマス由来のセバシン酸との重縮合物を用いることで、前述の課題を解決可能であることを見出した。本発明の要旨は以下のとおりである。 The present inventor conducted extensive studies in order to solve the above-mentioned problem. As a result, they found that the above-mentioned problems could be solved by using a polycondensate of diamine and biomass-derived sebacic acid as a binder constituting the magnet part of a magnetic encoder. The gist of the present invention is as follows.
　本発明の第一は、鋼板製の円環状支持部材と、該円環状支持部材に固定された円環状樹脂磁石とを有し、前記円環状樹脂磁石が、ポリアミド樹脂バインダー、磁性粉及びガラス繊維を含み、前記ポリアミド樹脂バインダーが、ジアミンとバイオマス由来のセバシン酸との重縮合物である、磁気エンコーダに関する。 A first aspect of the present invention includes a circular support member made of a steel plate and a circular resin magnet fixed to the circular support member, and the circular resin magnet includes a polyamide resin binder, magnetic powder, and glass fiber. , wherein the polyamide resin binder is a polycondensate of diamine and biomass-derived sebacic acid.
　本発明の実施形態では、前記ジアミンが、炭素数４～１２の脂肪族ジアミンであってもよい。 In an embodiment of the present invention, the diamine may be an aliphatic diamine having 4 to 12 carbon atoms.
　本発明の実施形態では、自動車のホイール支持用軸受装置用の磁気エンコーダであってもよい。 An embodiment of the present invention may be a magnetic encoder for a bearing device for supporting a wheel of an automobile.
　前述の実施形態は、任意に組み合わせることができる。 The above-described embodiments can be combined arbitrarily.
　本発明によると、磁気特性、耐熱性及び塩化カルシウム耐性が良好で、自然環境への負担が従来より軽減された磁気エンコーダを提供することができる。 According to the present invention, it is possible to provide a magnetic encoder that has good magnetic properties, heat resistance, and calcium chloride resistance, and has a lower burden on the natural environment than before.
本発明の実施形態に係る磁気エンコーダを備えた軸受装置の例を示す縦断面図である。1 is a longitudinal sectional view showing an example of a bearing device including a magnetic encoder according to an embodiment of the present invention. 図１に示す軸受装置の要部拡大断面図である。FIG. 2 is an enlarged sectional view of a main part of the bearing device shown in FIG. 1. FIG. 本発明の実施形態に係る磁気エンコーダを模式的に示す図である。1 is a diagram schematically showing a magnetic encoder according to an embodiment of the present invention.
　本発明の実施形態に係る磁気エンコーダは、鋼板製の円環状支持部材（以下、「支持部材」と称する場合がある。）と、この円環状支持部材に固定された円環状樹脂磁石（以下、「樹脂磁石」と称する場合がある。）とを有する。その円環状樹脂磁石は、ポリアミド樹脂バインダー、磁性粉及びガラス繊維を含む。そのポリアミド樹脂バインダーは、ジアミンとバイオマス由来のセバシン酸との重縮合物である。 A magnetic encoder according to an embodiment of the present invention includes an annular support member made of a steel plate (hereinafter sometimes referred to as a "support member"), and an annular resin magnet (hereinafter referred to as a "resin magnet") fixed to this annular support member. (sometimes referred to as "resin magnets"). The annular resin magnet includes a polyamide resin binder, magnetic powder, and glass fiber. The polyamide resin binder is a polycondensate of diamine and biomass-derived sebacic acid.
　ジカルボン酸成分としてセバシン酸を用いることで、得られるジアミンとの重縮合物であるポリアミド樹脂は、磁気エンコーダのバインダーとして用いられている従来のＰＡ６等のポリアミドやＰＰＳよりも良好な磁気特性、耐熱性及び塩化カルシウム耐性を有する。また、セバシン酸はバイオマス由来であるため、従来のポリアミドやＰＰＳのように石油由来の原料のみで合成されたバインダーと比べて環境負荷を低減することができる。 By using sebacic acid as the dicarboxylic acid component, the resulting polyamide resin, which is a polycondensate with diamine, has better magnetic properties and heat resistance than conventional polyamides such as PA6 and PPS, which are used as binders for magnetic encoders. resistant to calcium chloride. In addition, since sebacic acid is derived from biomass, it can have a lower environmental impact than conventional binders such as polyamide and PPS that are synthesized only from petroleum-derived raw materials.
　以下、磁気エンコーダの構成部材について説明する。 Hereinafter, the constituent members of the magnetic encoder will be explained.
　円環状支持部材は、鋼板製のものである。鋼板を構成する材質は、本技術分野において一般的に使用可能なものを適用可能である。このような材質としては、樹脂磁石の磁気特性を損なうことなく、相応の耐腐食性を有するものが好ましく、例えば、冷間圧延鋼板（ＳＰＣＣ）、ステンレス鋼などが挙げられる。ステンレス鋼としては、例えば、ＳＵＳ４３０等のフェライト系ステンレス鋼、ＳＵＳ４１０等のマルテンサイト系ステンレス鋼などの磁性を有するものが挙げられる。 The annular support member is made of steel plate. As the material constituting the steel plate, materials commonly available in this technical field can be used. Such a material is preferably one that does not impair the magnetic properties of the resin magnet and has appropriate corrosion resistance, such as cold rolled steel plate (SPCC), stainless steel, and the like. Examples of the stainless steel include those having magnetism, such as ferritic stainless steel such as SUS430 and martensitic stainless steel such as SUS410.
　支持部材の形状は、円環状である。例えば、図１～３に示すように軸受装置の回転体に取り付け可能な円環状で、かつ、断面形状が、外側に張り出した逆Ｌ字形状のもの、或いは、図示しないが、断面形状が、内側に張り出した逆Ｌ字形状のものなどが挙げられるが、これらに限定されるわけではない。 The shape of the support member is annular. For example, as shown in FIGS. 1 to 3, a ring-shaped bearing device that can be attached to a rotating body of a bearing device and an inverted L-shaped cross-sectional shape projecting outward, or a cross-sectional shape that is not shown in the drawings, Examples include, but are not limited to, an inverted L-shape that projects inward.
　支持部材の樹脂磁石との接合面は、必要に応じて、表面処理を施してもよい。このような表面処理は、例えば、接着剤を用いて樹脂磁石と支持部材を接合する場合に支持部材と接着剤との接合強度を向上させる場合に有効である。このような表面処理としては、例えば、粗面化処理、プライマー処理などが挙げられる。粗面化処理としては、例えば、ブラスト処理、ケミカルエッチング処理、化成処理、ヘアーライン処理などが挙げられる。粗面化処理を行った場合の表面粗さＲａは、例えば、Ｒａが０．５～２μｍとすることができる。面粗さＲａは、ＪＩＳ  Ｂ０６０１－１９９４に基づいて測定することができる。プライマー処理に使用可能なプライマーとしては、例えば、シラン系プライマー、フェノール系プライマー、エポキシ系プライマー等が挙げられる。 The joint surface of the support member with the resin magnet may be subjected to surface treatment, if necessary. Such surface treatment is effective, for example, when bonding a resin magnet and a support member using an adhesive to improve the bonding strength between the support member and the adhesive. Examples of such surface treatments include surface roughening treatment, primer treatment, and the like. Examples of the surface roughening treatment include blasting treatment, chemical etching treatment, chemical conversion treatment, and hairline treatment. The surface roughness Ra when the surface roughening treatment is performed can be, for example, 0.5 to 2 μm. Surface roughness Ra can be measured based on JIS B0601-1994. Examples of primers that can be used for primer treatment include silane primers, phenol primers, and epoxy primers.
　円環状樹脂磁石に含まれるポリアミド樹脂バインダーは、ジアミンとバイオマス由来のセバシン酸との重縮合物である。バイオマス由来のセバシン酸は、一般に、ヒマ（トウゴマ）の種子から採取されるひまし油に対して所定の処理を行って得られる炭素数１０の直鎖ジカルボン酸である。バイオマス由来のセバシン酸と重縮合させるジアミン成分は、特に限定はなく、脂肪族ジアミン、芳香族含有ジアミンなどが挙げられるが、環境対応の観点、靭性の観点から、脂肪族ジアミンが好ましい。脂肪族ジアミンとしては、耐熱性、磁気特性、塩化カルシウム耐性の観点から、炭素数４～１２の脂肪族ジアミンが好ましく、炭素数４～８の脂肪族ジアミンがより好ましい。また、脂肪族ジアミンを構成する脂肪族の構造は、直鎖状、分岐鎖状何れでもよいが、直鎖状が好ましい。好ましいバイオマス由来成分を含むポリアミド樹脂バインダーとしては、例えば、ポリアミド４１０、６１０、１０１０、１２１０等が挙げられる。このようなポリアミド樹脂バインダーは、定法に従って、バイオマス由来のセバシン酸とジアミンを重縮合させることで得ることができる。また、市販のものを用いることもできる。ポリアミド樹脂バインダーの分子量は、樹脂磁石の強度などの特性や、成形性等を考慮して適宜選択可能である。分子量の指標として、例えば、粘度数を用いることができ、使用するジアミンに応じて所定の粘度数を有するものを選択することが可能である。このような粘度数（ＶＮ値）は、ポリアミド４１０では、例えば、１２５～１７５ｍｌ／ｇのものを用いることができ、ポリアミド６１０では、例えば、１３０～１７０ｍｌ／ｇのものを用いることができる。粘度数（ＶＮ値）は、ＩＳＯ　３０７に準拠して測定することができる。 The polyamide resin binder contained in the annular resin magnet is a polycondensate of diamine and sebacic acid derived from biomass. Biomass-derived sebacic acid is generally a linear dicarboxylic acid having 10 carbon atoms obtained by subjecting castor oil collected from castor seeds to a certain treatment. The diamine component to be polycondensed with biomass-derived sebacic acid is not particularly limited, and examples include aliphatic diamines and aromatic-containing diamines, but aliphatic diamines are preferred from the viewpoint of environmental friendliness and toughness. As the aliphatic diamine, from the viewpoint of heat resistance, magnetic properties, and resistance to calcium chloride, aliphatic diamines having 4 to 12 carbon atoms are preferred, and aliphatic diamines having 4 to 8 carbon atoms are more preferred. Further, the aliphatic structure constituting the aliphatic diamine may be either linear or branched, but preferably linear. Examples of preferable polyamide resin binders containing biomass-derived components include polyamides 410, 610, 1010, and 1210. Such a polyamide resin binder can be obtained by polycondensing biomass-derived sebacic acid and diamine according to a conventional method. Moreover, commercially available products can also be used. The molecular weight of the polyamide resin binder can be appropriately selected in consideration of properties such as strength of the resin magnet, moldability, and the like. For example, a viscosity number can be used as an indicator of molecular weight, and it is possible to select a diamine having a predetermined viscosity number depending on the diamine used. Such a viscosity number (VN value) can be, for example, 125 to 175 ml/g for polyamide 410, and 130 to 170 ml/g for polyamide 610, for example. The viscosity number (VN value) can be measured in accordance with ISO 307.
　ポリアミド樹脂バインダーの含有量は、円環状樹脂磁石中５～２０質量％が好ましい。 The content of the polyamide resin binder is preferably 5 to 20% by mass in the annular resin magnet.
　円環状樹脂磁石に含まれる磁性粉は、インサート成形により製造された市販の磁気エンコーダのプラスチック磁石部に使用されている磁性体粉であればよく、例えば、ストロンチウムフェライトやバリウムフェライト等のフェライト系磁性粉末、ネオジム系やサマリウム系等の希土類磁性粉末が使用できる。また、フェライトの磁気特性を向上させるためにランタンとコバルト等を混入したり、フェライトの一部をネオジウム－鉄－ボロン、サマリウム－コバルト、サマリウム－鉄等の希土類磁性体粉に置き換えてもよい。これらの磁性体粉は単独で用いてもよいし、２種以上を組み合わせて用いてもよい。 The magnetic powder contained in the annular resin magnet may be any magnetic powder used in the plastic magnet part of commercially available magnetic encoders manufactured by insert molding, such as ferrite magnetic powder such as strontium ferrite and barium ferrite. Powder, rare earth magnetic powder such as neodymium-based or samarium-based powder can be used. Furthermore, in order to improve the magnetic properties of ferrite, lanthanum, cobalt, etc. may be mixed, or a portion of ferrite may be replaced with rare earth magnetic powder such as neodymium-iron-boron, samarium-cobalt, samarium-iron, etc. These magnetic powders may be used alone or in combination of two or more.
　磁性粉の含有量は、円環状樹脂磁石中７５～８８質量％が好ましい。 The content of magnetic powder is preferably 75 to 88% by mass in the annular resin magnet.
　円環状樹脂磁石に含まれるガラス繊維は、特に限定はないが、細かく裁断されたものが好ましい。ガラス繊維の含量は、円環状樹脂磁石中３～１５質量％が好ましい。 The glass fiber contained in the annular resin magnet is not particularly limited, but it is preferably finely cut. The content of glass fiber in the annular resin magnet is preferably 3 to 15% by mass.
　円環状樹脂磁石には、必要に応じて、他の成分が含まれていてもよい。このような成分としては、例えば、カーボンファイバー等の有機系添加剤、ガラスビーズ、タルク、マイカ、窒化珪素（セラミック）及び結晶性（非結晶性）シリカ等の無機系添加剤、ベンゼンスルホン酸アルキルアミド類、トルエンスルホン酸アルキルアミド類、及びヒドロキシ安息香酸アルキルエステル類等が挙げられる。これらは単独で用いてもよいし、２種以上を組み合わせて用いてもよい。 The annular resin magnet may contain other components as necessary. Examples of such components include organic additives such as carbon fiber, inorganic additives such as glass beads, talc, mica, silicon nitride (ceramic) and crystalline (non-crystalline) silica, and alkyl benzenesulfonates. Amides, toluenesulfonic acid alkyl amides, and hydroxybenzoic acid alkyl esters are included. These may be used alone or in combination of two or more.
　支持部材と樹脂磁石とは、物理的な構造で固定されていてもよいし、接着剤層を介して固定されていてもよいし、これらを組み合わせて固定されていてもよい。接着剤層を構成し得る接着剤としては、例えば、熱硬化性樹脂接着剤が挙げられる。このような熱硬化性樹脂接着剤としては、例えば、フェノール樹脂系接着剤やエポキシ樹脂系接着剤等が挙げられる。このような接着剤は、例えば、特開２０１６－２２１９５２号公報に記載のものを使用することができる。フェノール樹脂系接着剤及びエポキシ樹脂系接着剤の概要は以下のとおりである。 The support member and the resin magnet may be fixed by a physical structure, may be fixed via an adhesive layer, or may be fixed by a combination of these. Examples of adhesives that can constitute the adhesive layer include thermosetting resin adhesives. Examples of such thermosetting resin adhesives include phenol resin adhesives and epoxy resin adhesives. As such an adhesive, for example, one described in JP-A No. 2016-221952 can be used. The outline of phenolic resin adhesive and epoxy resin adhesive is as follows.
  フェノール樹脂系接着剤は、例えば、ノボラック型フェノール樹脂やレゾール型フェノール樹脂と、ヘキサメチレンテトラミン等の硬化剤を、メタノールやメチルエチルケトン等の溶剤に溶解させたものが使用できる。また、接着性を向上させるために、これらにノボラック型エポキシ樹脂を混合した接着剤も使用できる。 As the phenolic resin adhesive, for example, one in which a novolak type phenol resin or resol type phenol resin and a curing agent such as hexamethylenetetramine are dissolved in a solvent such as methanol or methyl ethyl ketone can be used. Furthermore, in order to improve adhesiveness, adhesives in which a novolak type epoxy resin is mixed with these can also be used.
  エポキシ樹脂系接着剤としては、原液が一液型エポキシ系接着剤で、溶剤への希釈が可能な接着剤が挙げられる。一液型エポキシ系接着剤としては、エポキシ樹脂及び硬化剤からなり、必要に応じて反応性希釈剤として使用されるその他のエポキシ化合物、熱硬化速度を向上させる硬化促進剤、耐熱性や耐硬化歪み性を向上させる効果がある無機充填材、応力がかかった時に変形する可撓性を向上させる架橋ゴム微粒子等をさらに添加してもよい。 Epoxy resin adhesives include adhesives that are one-component epoxy adhesives that can be diluted with a solvent. One-component epoxy adhesives consist of an epoxy resin and a curing agent, and if necessary, other epoxy compounds used as reactive diluents, curing accelerators to improve heat curing speed, heat resistance and curing resistance. Inorganic fillers that have the effect of improving distortion properties, crosslinked rubber fine particles that improve flexibility to deform when stress is applied, etc. may be further added.
　磁気エンコーダの実施形態の一例を図面に基づき説明すると以下のとおりである。以下の実施形態では、自動車のホイール支持用軸受装置に適用した場合を例にしたものであるが、これに限定されるわけではない。 An example of an embodiment of a magnetic encoder will be described below based on the drawings. In the following embodiments, an example is given in which the present invention is applied to a bearing device for supporting a wheel of an automobile, but the present invention is not limited thereto.
　図１は、本発明の実施形態に係る磁気エンコーダを備えた軸受装置の例を示す縦断面図である。図２は、図１に示す軸受装置の要部拡大断面図である。図１及び図２に示すように、本発明の実施形態に係る磁気エンコーダ１を備えた軸受装置１１は、外周面に内輪軌道面１２Ａが形成された内輪１２、及び内周面に外輪軌道面１３Ａが形成された外輪１３、並びに、内輪軌道面１２Ａ及び外輪軌道面１３Ａ間を転動する転動体１４、１４、等を有する軸受、この軸受の軸方向の一端部に位置して内輪１２に固定された磁気エンコーダ１、並びに、外輪１３に固定された、磁気エンコーダ１の磁極に対向して磁気エンコーダ１の回転を検知するためのセンサ１０、前記軸受の軸方向の一端部及び他端部に配置したシール部材６、７等を備えている。 FIG. 1 is a longitudinal sectional view showing an example of a bearing device equipped with a magnetic encoder according to an embodiment of the present invention. FIG. 2 is an enlarged sectional view of a main part of the bearing device shown in FIG. As shown in FIGS. 1 and 2, a bearing device 11 equipped with a magnetic encoder 1 according to an embodiment of the present invention includes an inner ring 12 having an inner ring raceway surface 12A formed on its outer circumferential surface, and an outer ring raceway surface formed on its inner circumferential surface. 13A, and rolling elements 14, 14, etc. that roll between the inner ring raceway surface 12A and the outer ring raceway surface 13A. A fixed magnetic encoder 1, a sensor 10 fixed to an outer ring 13 for detecting rotation of the magnetic encoder 1 facing the magnetic poles of the magnetic encoder 1, and one end and the other end of the bearing in the axial direction. It is equipped with seal members 6, 7, etc. arranged at.
  ここで、回転側である内輪１２に取り付けられた、Ｎ極とＳ極を一定間隔で周方向に多極に着磁した樹脂磁石を有する磁気エンコーダ１、及び固定側である外輪１３に取り付けられたセンサ１０が、回転速度検出装置を構成する。 Here, a magnetic encoder 1 is attached to an inner ring 12 on the rotating side, and has a resin magnet magnetized in multiple circumferential directions with N and S poles spaced at regular intervals, and a magnetic encoder 1 is attached to an outer ring 13 on the stationary side. The sensor 10 constitutes a rotational speed detection device.
  図３は、本発明の実施形態に係る磁気エンコーダ１を模式的に示した図である。図３（ａ）は、磁気エンコーダ１の断面を模式的に示した図であり、図３（ｂ）は、磁気エンコーダ１の円環状の一部を模式的に示した一部切り欠き斜視断面図である。回転体に取り付け可能な円環状支持部材２と、支持部材２に取り付けられ、円周方向に多極に着磁された厚みＴの円環状樹脂磁石３とを備えている。本実施形態では、支持部材２と樹脂磁石３とは、接着剤層４を介して固定されている。 3 is a diagram schematically showing the magnetic encoder 1 according to the embodiment of the present invention. 3(a) is a diagram schematically showing a cross section of the magnetic encoder 1, and FIG. 3(b) is a partially cutaway perspective cross-sectional diagram schematically showing a part of the annular shape of the magnetic encoder 1. It is a diagram. It includes an annular support member 2 that can be attached to a rotating body, and an annular resin magnet 3 with a thickness T that is attached to the support member 2 and magnetized to have multiple poles in the circumferential direction. In this embodiment, the support member 2 and the resin magnet 3 are fixed via an adhesive layer 4.
  図３に示す断面形状が逆Ｌ字形状の支持部材２を用いた磁気エンコーダ１は、例えば、図２に示すように回転体である内輪１２の軸方向外端側に嵌合させることができる。 The magnetic encoder 1 using the support member 2 having an inverted L-shaped cross section as shown in FIG. 3 can be fitted, for example, to the outer end in the axial direction of the inner ring 12, which is a rotating body, as shown in FIG. .
  樹脂磁石３は、例えば図３に示すように支持部材２の断面形状が外側に張り出した逆Ｌ字形状である場合、張り出した部分の上面５ａ及び外側面５ｂを覆うように取り付けてもよい。或いは、さらに内側面５ｃの一部又は全部を覆うように取り付けてもよい。また、上面５ａのみを覆うように取り付けてもよい。この際の樹脂磁石３の厚みＴ等の各寸法については、特に限定はなく、適宜決定することができる。 For example, when the cross-sectional shape of the support member 2 is an inverted L-shape projecting outward as shown in FIG. 3, the resin magnet 3 may be attached so as to cover the top surface 5a and outer surface 5b of the projecting portion. Alternatively, it may be further attached so as to cover part or all of the inner surface 5c. Alternatively, it may be attached so as to cover only the upper surface 5a. At this time, each dimension such as the thickness T of the resin magnet 3 is not particularly limited and can be determined as appropriate.
　このような磁気エンコーダ１は、インサート成形等により得ることができる。このようなインサート成形としては、例えば、特開２０１６－２２１９５２号公報に記載の方法などが挙げられる。 Such a magnetic encoder 1 can be obtained by insert molding or the like. Examples of such insert molding include the method described in JP-A No. 2016-221952.
　以下、実施例に基づき、本発明に係る磁気エンコーダの実施形態を具体的に説明する。 Hereinafter, embodiments of the magnetic encoder according to the present invention will be specifically described based on Examples.
（実施例１）
　磁性粉（フェライト系磁性粉）、ＰＡ４１０（テトラメチレンジアミンとひまし油由来のセバシン酸との重縮合物）、ガラス繊維を表１の配合で定法に従い混錬し、射出成形用の樹脂磁石組成物を得た。当該樹脂磁石組成物を用い、特開２０１６－２２１９５２号公報の実施例に記載の方法に準拠して、支持部材に対してインサート成形を行った。概要は以下のとおりである。
　図２に示す形状の支持部材（材質：ＳＵＳ４３０）２の樹脂磁石３との接合面（図２（ａ）符号５ａ、５ｂ）になる部分に熱硬化性接着剤（フェノール系接着剤）を塗布し、自然乾燥し、乾燥固化させた。熱硬化性接着剤を乾燥固化させた支持部材を金型内に設置して型締めした状態で、射出成形機により、金型内に配向磁場をかけながら、溶融した状態の前述の樹脂磁石組成物を所定形状のキャビティに射出し、接着剤を乾燥固化させた接合面上に円環状の樹脂磁石を成形した。次いで、熱硬化性接着剤の架橋反応開始温度以上の温度で加熱し、硬化した接着剤を介して支持部材と樹脂磁石を一体化させた。着磁は着磁ヨークにより行い、磁気エンコーダを得た。尚、樹脂磁石部の厚さＴ（図３（ａ）の符号Ｔ参照）は０．９ｍｍとした。 (Example 1)
Magnetic powder (ferrite magnetic powder), PA410 (polycondensate of tetramethylene diamine and sebacic acid derived from castor oil), and glass fiber were kneaded according to a standard method in the proportions shown in Table 1 to obtain a resin magnet composition for injection molding. Obtained. Using the resin magnet composition, insert molding was performed on a support member in accordance with the method described in Examples of JP-A-2016-221952. The outline is as follows.
A thermosetting adhesive (phenolic adhesive) is applied to the part of the supporting member (material: SUS430) 2 having the shape shown in FIG. Then, it was air-dried and solidified. A supporting member made of a dried and solidified thermosetting adhesive is installed in a mold and the mold is clamped, and an orienting magnetic field is applied inside the mold by an injection molding machine, and the above-mentioned resin magnet composition in a molten state is applied. The object was injected into a cavity of a predetermined shape, and an annular resin magnet was molded on the joint surface where the adhesive was dried and solidified. Next, the support member and the resin magnet were integrated by heating at a temperature equal to or higher than the crosslinking reaction initiation temperature of the thermosetting adhesive via the cured adhesive. Magnetization was performed using a magnetizing yoke to obtain a magnetic encoder. The thickness T (see symbol T in FIG. 3(a)) of the resin magnet portion was 0.9 mm.
（実施例２、比較対象１、２）
　各成分の配合を表１のように変更した以外は、実施例１と同様にして、磁気エンコーダを得た。 (Example 2, comparison targets 1 and 2)
A magnetic encoder was obtained in the same manner as in Example 1, except that the composition of each component was changed as shown in Table 1.
　実施例２で用いたバインダー樹脂は下記のとおりである。
　・ＰＡ６１０
　　ヘキサメチレンジアミンとひまし油由来のセバシン酸との重縮合物 The binder resin used in Example 2 is as follows.
・PA610
Polycondensate of hexamethylene diamine and sebacic acid derived from castor oil
　比較対象１、２で用いたバインダー樹脂は下記のとおりである。
　・ＰＡ６
　　ε－カプロラクタムの開環重縮合物
　・ＰＰＳ
　　直鎖型 The binder resins used in Comparisons 1 and 2 are as follows.
・PA6
Ring-opening polycondensate of ε-caprolactam ・PPS
Straight chain type
（評価）
＜高温放置試験＞
　実施例１、２、比較対象１、２で得られた磁気エンコーダを、２１０℃で２４時間加熱した後、樹脂磁石の着磁表面の状態を目視により確認した。 (evaluation)
<High temperature storage test>
After heating the magnetic encoders obtained in Examples 1 and 2 and Comparative Examples 1 and 2 at 210° C. for 24 hours, the state of the magnetized surface of the resin magnet was visually confirmed.
＜熱衝撃性能＞
　実施例１、２、比較対象１、２で得られた磁気エンコーダを用い、－４０℃で３０分間保持と、１２０℃で３０分間保持を１サイクルとする熱衝撃試験を行った。１００サイクル毎に外観を観察し、割れ、欠け、クラック、形状変化などの欠陥の有無を確認し、これらの欠陥のうちいずれかが発生した場合は、その時点で試験を終了し、サイクル数を記録した。比較例対象１のサイクル数を基準（１００）とし、実施例１、２、比較対象２の欠陥の発生したサイクル数の相対値を算出した。 <Thermal shock performance>
Using the magnetic encoders obtained in Examples 1 and 2 and Comparatives 1 and 2, a thermal shock test was conducted using one cycle of holding at -40°C for 30 minutes and holding at 120°C for 30 minutes. The appearance is observed every 100 cycles to check for defects such as cracks, chips, cracks, and changes in shape. If any of these defects occur, the test is terminated at that point and the number of cycles is determined. Recorded. Using the number of cycles of Comparative Example Subject 1 as a reference (100), relative values of the number of cycles in which defects occurred in Examples 1, 2, and Comparative Subject 2 were calculated.
＜耐ＣａＣｌ２試験＞
　実施例１、２、比較対象１、２で得られた磁気エンコーダを用い、下記のようにして耐塩化カルシウム（ＣａＣｌ２）試験を行った。
　（１）５０℃、湿度９５％ＲＨで２４時間放置
　（２）樹脂磁石の表面全体に塩化カルシウム（ＣａＣｌ２）５質量％水溶液を綿棒にて塗布
　（３）室温で３０分間放置
　（４）１００℃で３時間乾燥
　（５）５０℃、湿度９５％ＲＨで２０時間放置
　この後（２）～（５）を最大１９回繰り返して、樹脂磁石が損傷するかどうかを目視により確認した。 <CaCl resistance 2 test>
Using the magnetic encoders obtained in Examples 1 and 2 and Comparisons 1 and 2, a calcium chloride resistance (CaCl 2 ) test was conducted as follows.
(1) Leave at 50°C and 95% RH for 24 hours. (2) Apply a 5% by mass aqueous solution of calcium chloride (CaCl 2 ) to the entire surface of the resin magnet using a cotton swab. (3) Leave at room temperature for 30 minutes. (4) 100 Drying at ℃ for 3 hours (5) Leaving for 20 hours at 50 ℃ and 95% RH After this, steps (2) to (5) were repeated up to 19 times, and it was visually confirmed whether the resin magnet was damaged.
＜磁束密度＞
　実施例１、２、比較対象１、２で得られた磁気エンコーダを用い、マグネットアナライザーにより磁束密度を測定した。比較対象１の測定値を基準（１００）とし、実施例１、２、比較対象２の測定値の相対値を算出した。 <Magnetic flux density>
Using the magnetic encoders obtained in Examples 1 and 2 and Comparisons 1 and 2, magnetic flux density was measured with a magnet analyzer. Using the measured value of Comparative Subject 1 as a reference (100), relative values of the measured values of Examples 1, 2, and Comparative Subject 2 were calculated.
＜流動特性＞
　実施例１、２、比較対象１で調製した射出成形用の樹脂磁石組成物について、ＩＳＯ　１１３３に準拠して、測定温度３００℃での溶融質量を測定した。比較対象１の測定値を基準（１００）とし、実施例１、２の測定値の相対値を算出した。尚、比較対象２については、ＰＰＳの融点が他と大きく異なり、同一条件での比較が困難なため測定しなかった。 <Flow characteristics>
Regarding the resin magnet compositions for injection molding prepared in Examples 1 and 2 and Comparative Subject 1, the melt mass at a measurement temperature of 300° C. was measured in accordance with ISO 1133. Using the measured value of Comparison 1 as a reference (100), the relative values of the measured values of Examples 1 and 2 were calculated. It should be noted that comparison target 2 was not measured because the melting point of PPS was significantly different from the others and it was difficult to compare under the same conditions.
　以上の評価結果を表１に示す。 The above evaluation results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１に示すように、ジカルボン酸としてバイオマス由来のセバシン酸を用いて得られるジアミンとの重縮合物であるポリアミド樹脂を用いることで、従来のＰＡ６やＰＰＳを用いた場合と比較して、磁束密度、熱衝撃性能が高く、かつ、塩化カルシウム耐性及び耐熱性を有することが分かる。特に、バイオマス由来の原料を用いて合成されたＰＡ６１０を用いた実施例２は、比較対象１、２より、流動特性が大幅に優れ、磁束密度及び熱衝撃特性も向上していることが分かる。したがって、ＰＡ６１０を樹脂バインダーとして用いた磁気エンコーダは、従来よりも良好な特性を有するとともに、自然環境への負担軽減が可能であり、特に有用である。
　また、比較対象１と比較して実施例１、２で用いた射出成形用の樹脂磁石組成物の流動特性が高く、磁場成形時の磁粉配向率を従来より向上させることができる。このことは、少ない磁粉量で目標磁力が得られることを意味する。つまり、磁粉量を少なくして樹脂成分等を増やすことが可能になる。その結果、樹脂磁石の靭性、熱衝撃性能をより向上させることが期待できる。前述のように、樹脂バインダーとしてＰＡ６１０を用いることで流動特性が大幅に優れており、これらの特性の向上をより一層期待することができる。 As shown in Table 1, by using polyamide resin, which is a polycondensate with diamine obtained using biomass-derived sebacic acid as the dicarboxylic acid, the magnetic flux is lower than when using conventional PA6 or PPS. It can be seen that it has high density and thermal shock performance, as well as calcium chloride resistance and heat resistance. In particular, it can be seen that Example 2, which uses PA610 synthesized using biomass-derived raw materials, has significantly better flow characteristics than Comparatives 1 and 2, and also has improved magnetic flux density and thermal shock characteristics. Therefore, a magnetic encoder using PA610 as a resin binder is particularly useful because it has better characteristics than conventional ones and can reduce the burden on the natural environment.
Moreover, the flow characteristics of the resin magnet composition for injection molding used in Examples 1 and 2 are higher than that of Comparison 1, and the magnetic particle orientation rate during magnetic field molding can be improved compared to the conventional one. This means that the target magnetic force can be obtained with a small amount of magnetic particles. In other words, it becomes possible to reduce the amount of magnetic particles and increase the amount of resin components. As a result, it is expected that the toughness and thermal shock performance of the resin magnet will be further improved. As mentioned above, by using PA610 as the resin binder, the fluidity properties are significantly improved, and further improvements in these properties can be expected.
　１  磁気エンコーダ
  ２  円環状支持部材
  ３  円環状樹脂磁石
  ４  接着剤層
  ５ａ  円環状支持部材２の上面
  ５ｂ  円環状支持部材２の外側面
  ５ｃ  円環状支持部材２の内側面
  ６、７  シール部材
  １０  センサ
  １１  軸受装置
  １２  内輪
  １２Ａ  内輪軌道面
  １３  外輪
  １３Ａ  外輪軌道面
  １４  転動体
　Ｔ　円環状樹脂磁石２の厚み
 
  1 Magnetic encoder 2 Annular support member 3 Annular resin magnet 4 Adhesive layer 5a Upper surface of annular support member 2 5b Outer surface of annular support member 2 5c Inner surface of annular support member 2 6, 7 Seal member 10 Sensor 11 Bearing device 12 Inner ring 12A Inner ring raceway surface 13 Outer ring 13A Outer ring raceway surface 14 Rolling element T Thickness of annular resin magnet 2

Claims (3)

  1. 　鋼板製の円環状支持部材と、該円環状支持部材に固定された円環状樹脂磁石とを有し、
    　前記円環状樹脂磁石が、ポリアミド樹脂バインダー、磁性粉及びガラス繊維を含み、
    　前記ポリアミド樹脂バインダーが、ジアミンとバイオマス由来のセバシン酸との重縮合物である、磁気エンコーダ。     It has an annular support member made of a steel plate and an annular resin magnet fixed to the annular support member,
    The annular resin magnet includes a polyamide resin binder, magnetic powder, and glass fiber,
    A magnetic encoder, wherein the polyamide resin binder is a polycondensate of diamine and biomass-derived sebacic acid.
  2. 　前記ジアミンが、炭素数４～１２の脂肪族ジアミンである、請求項１記載の磁気エンコーダ。 The magnetic encoder according to claim 1, wherein the diamine is an aliphatic diamine having 4 to 12 carbon atoms.
  3. 　自動車のホイール支持用軸受装置用である、請求項１又は２に記載の磁気エンコーダ。
     
          The magnetic encoder according to claim 1 or 2, which is used for a bearing device for supporting a wheel of an automobile.
PCT/JP2023/018761 2022-09-14 2023-05-19 Magnetic encoder WO2024057621A1 (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006047268A (en) * 2004-05-19 2006-02-16 Nsk Ltd Manufacturing method for magnetic encoder
JP2008010460A (en) * 2006-06-27 2008-01-17 Sumitomo Metal Mining Co Ltd Composition for bond magnet, bond magnet employing it, and its production process

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006047268A (en) * 2004-05-19 2006-02-16 Nsk Ltd Manufacturing method for magnetic encoder
JP2008010460A (en) * 2006-06-27 2008-01-17 Sumitomo Metal Mining Co Ltd Composition for bond magnet, bond magnet employing it, and its production process

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