JP5200654B2 - Manufacturing method of slinger with encoder and rolling bearing unit with encoder - Google Patents

Description

The present invention, for example, a rotation detection function that is assembled to the end of a hub that is a rotation-side bearing ring that constitutes a wheel bearing rolling bearing unit for rotatably supporting a wheel of an automobile or the like with respect to a suspension device. The present invention relates to a slinger with an encoder in which a slinger and a seal lip constituting a sealing device are integrated, and an improvement in a method for manufacturing a rolling bearing unit having such a slinger with an encoder .

  In order to control the anti-lock brake system (ABS) and the traction control system (TCS), it is necessary to determine the rotational speed of the wheels. For this reason, magnetic characteristics are alternately applied to the rotating raceway (hub) constituting the wheel bearing rolling bearing unit (hub unit) for rotatably supporting the wheel with respect to the suspension device in the circumferential direction. It is widely practiced to fix a changed encoder (generally at regular intervals). Further, the wheel bearing rolling bearing unit incorporates a seal device (combined seal ring) in which a seal ring and a slinger are combined, so that foreign matters existing in the external space are present in the internal space where a plurality of rolling elements are installed. It is possible to prevent the grease that enters or leaks in this internal space. And combining the encoder and the slinger and integrating them has been widely known, for example, as described in Patent Documents 1 to 4.

  One example of the wheel bearing rolling bearing unit and the encoder-equipped slinger will be described with reference to FIGS. The wheel supporting rolling bearing unit 1 is configured such that a hub 3 that is a rotating raceway is provided on an inner diameter side of an outer ring 2 that is a stationary raceway by a plurality of balls 4 and 4 that are rolling elements, respectively. I support it. In the case of a wheel bearing rolling bearing unit such as a heavy automobile, a tapered roller may be used as a rolling element instead of a ball. The hub 3 is formed by combining a hub body 5 and an inner ring 6. When the wheel support rolling bearing unit 1 is used, the outer ring 2 is fixed to a suspension device by a fixing flange 7, and a braking rotating body such as a rotor and a wheel are fixed to a rotating flange 8 of the hub 3. Of the openings at both ends of the inner space 9 between the outer peripheral surface of the hub 3 and the inner peripheral surface of the outer ring 2 where the balls 4 and 4 are installed, the opening on the rotating flange 8 side is the seal ring 10. Thus, the opposite side openings are respectively closed by the combination seal ring 11. Further, entry of foreign matter into the internal space 9 and leakage of grease existing in the internal space 9 are prevented.

  In order to control the ABS and TCS, an encoder 12 (see FIG. 3) has been incorporated in the combined seal ring 11 in order to obtain a signal representing the rotational speed of the hub 3. Of these, the combined seal ring 11 is formed by combining a slinger 13 and a seal ring 14. Of these, the slinger 13 is formed by bending a metal plate such as a stainless steel plate to form an annular shape as a whole with an L-shaped cross section. The slinger 13 includes an inner cylindrical portion 15 and an outward ring portion 16. The seal ring 14 includes a cored bar 17 and a sealing material 18. Of these, the metal core 17 is formed by bending a metal plate such as a stainless steel plate to form an entire ring shape with an L-shaped cross section, and includes an outer-diameter cylindrical portion 19 and an inward annular portion 20. Further, the seal material 18 is made of an elastomer such as rubber and has three seal lips 21a, 21b, and 21c. The combined seal ring 11 is configured such that the inner diameter side cylindrical portion 15 of the slinger 13 is fitted and fixed to the end of the hub 3 (the inner ring 6 constituting the hub 3), and the outer diameter side cylindrical portion 19 of the core metal 17 is fixed to the outer ring. The inner space 9 is assembled to the open end of the inner space 9 while being fitted and fixed to the end of 2. In this state, the leading edges of the seal lips 21a, 21b, and 21c are slidably contacted with the surface of the slinger 13 over the entire circumference, thereby closing the open end of the internal space 9.

  The encoder 12 is joined and fixed concentrically to the inner diameter side cylindrical portion 15 over the entire circumference on the side of the outward ring portion 16 of the slinger 13 opposite to the inner space 9. The encoder 12 is made of a permanent magnet and is magnetized in the axial direction. The magnetization direction is changed alternately and at equal intervals in the circumferential direction. Therefore, the S pole and the N pole are alternately arranged at equal intervals in the circumferential direction on one side surface in the axial direction of the encoder 12, which is the detected surface. When the rotational speed of the hub 3 is measured using such an encoder 12, as shown in FIG. 3, the detection part of the sensor 22 supported and fixed to the non-rotating outer ring 2 or the suspension device is made minute. Opposing through a gap. When the encoder 12 rotates together with the hub 3, the output signal of the sensor 22 changes. Since the frequency at which the output signal changes is proportional to the rotational speed of the hub 3, the rotational speed of the wheel fixed to the hub 3 can be obtained by sending this output signal to the controller.

  In the case of the first example of the conventional structure shown in FIG. 3 shown in FIG. 3, for example, no sealing lip is provided on the slinger 13 side, and the sealing performance of the opening end of the internal space 9 is It is held only by the seal lips 21a, 21b, 21c of the sealing material 18 provided on the seal ring 14 side. In general, an encoder material is pressed against the outward ring portion 16 in a state where an adhesive is applied to the outward ring portion 16 of the slinger 13, and the encoder 12 is applied to the slinger 13 by press molding. Join. In general, a nitrile rubber containing magnetic powder such as ferrite is used as the encoder material, and the magnetic powder is mechanically oriented by forming it into a sheet with a roll.

  On the other hand, in the case of the second example of the conventional structure described in Patent Document 3, for example, as shown in FIGS. 1 and 2, in addition to providing the seal material 18a on the seal ring 14a side, the slinger 13a side Further, by providing the sealing material 18b, the number of the sealing lips 21a to 21d is increased to improve the sealing performance. However, in the conventional case, in order to realize the structure shown in FIGS. 1 and 2, the sealing material 18b and the encoder 12a are bonded and fixed to the slinger 13a with the same kind of adhesive. For this reason, the sealing material 18b and the encoder 12a need to be materials that can be bonded and fixed with the same kind of adhesive. Of these, the sealing material 18b must be made of a rubber material at present in order to provide a sealing lip having sufficient elasticity. For this reason, the material of the encoder 12a also needs to be a rubber magnet that can be vulcanized and bonded (manufacturing other than the rubber magnet is practically difficult or impossible).

  For this reason, conventionally, the encoder 12a has a structure as shown in FIGS. 1 and 2 and cannot be made of a plastic magnet, which is more advantageous than a rubber magnet in terms of ensuring performance. That is, a plastic magnet in a solid state has no reactivity like unvulcanized rubber. For this reason, the plastic magnet is set in a mold for molding the sealing material 18b in a state combined with the slinger 13a coated with a semi-cured adhesive, and the sealing material 18b is set against the slinger 13a. Even if the history of pressure and temperature during vulcanization bonding is given, the bonding strength with the slinger 13a cannot be increased to a practical level. Therefore, conventionally, as shown in FIGS. 1 and 2, in the structure in which the encoder 12a and the sealing material 18b are joined to the slinger 13a, the encoder 12a is provided with a surface such as strength, durability, magnetization strength, and pitch accuracy. Therefore, it was not possible to make a plastic magnet, which makes it easier to obtain better performance than a rubber magnet.

JP 2001-255337 A JP 2004-190736 A JP 2006-220270 A JP 2006-220269 A

In view of the circumstances as described above, the present invention has a structure in which an encoder and a sealing material are joined to a slinger, and the encoder can be made of a plastic magnet that easily obtains performance superior to that of a rubber magnet. And an invention for realizing a method of manufacturing a rolling bearing unit with an encoder .

  The slinger with encoder which is the object of the manufacturing method of the present invention constitutes a rolling bearing unit with encoder. The encoder-equipped rolling bearing unit includes a fixed-side raceway and a rotary-side raceway, a plurality of rolling elements, a seal device, and an encoder. The fixed side raceway and the rotation side raceway are arranged concentrically with each other. Each of the rolling elements is arranged so as to be able to roll while being held by a cage, between the raceway surfaces provided on the mutually opposing surfaces of these raceways. The sealing device closes an end opening of an internal space in which the rolling elements are provided. Furthermore, the encoder is supported concentrically with a part of the slinger made of a magnetic metal plate constituting the seal device in a state of being fixed to a part of the rotating side raceway, over the entire circumference. It is made of a plastic magnet, and S poles and N poles are alternately arranged on the detection surface.

Particularly, in the present invention, the method of manufacturing the slinger with an encoder according to claim 1 is characterized in that an adhesive is applied to a portion of the slinger where the encoder is to be installed (for example, the slinger is in a solution in which the adhesive is melted). The slinger is set in a mold cavity for injection molding of the encoder. Then, a plastic magnet material in which magnetic powder is mixed in a thermoplastic resin is fed into the cavity in a molten state while applying a magnetic field, and the encoder and the slinger are bonded and fixed. Thereafter, another adhesive is applied to the slinger (for example, by immersing the slinger in a solution in which the other adhesive is melted), and the other adhesive is made into a semi-cured state. An unvulcanized seal lip is combined with a slinger to which the encoder is joined and fixed. Next, the seal lip and the slinger are bonded by vulcanization in a mold, for example, and the base of the seal lip is bonded and fixed to a part of the slinger.
On the other hand, in the manufacturing method of the rolling bearing unit with an encoder according to claim 6, the slinger, the encoder, and the seal lip are joined and fixed by the manufacturing method of the slinger with encoder as described above.

In the case of carrying out the invention described in the first and sixth aspects, it is preferable that, as in the invention described in the second aspect, a molten state is formed in a cavity of a mold for injection molding of the encoder. The gate into which the thermoplastic resin is fed is a ring gate provided on the outer periphery of the cavity. Then, after removing the burrs formed on the portion corresponding to the ring gate after the injection molding, the encoder is magnetized, and S poles and N poles are alternately arranged on the detection surface. The encoder or the plastic magnet is originally after magnetization, but in the present specification and claims, the encoder and the plastic magnet are also referred to as encoder and plastic magnet.

In the method of manufacturing the slinger with encoder described in claim 3, after applying an adhesive to the slinger, the slinger is combined with a rubber-made unvulcanized seal lip. Thereafter, the slinger and the seal lip are vulcanized and bonded, and the base of the seal lip is joined and fixed to a part of the slinger. Next, the encoder made separately by injection molding a plastic magnet material in which magnetic powder is mixed in a thermoplastic resin is bonded and fixed to the slinger with another adhesive.
As such another adhesive, a room temperature curable adhesive capable of bonding at room temperature is preferably used as in the invention described in claim 4.

  Further, when carrying out the invention described in claims 3 to 4 as described above, preferably, in the cavity of the mold for injection molding of the encoder, as in the invention described in claim 5, The gate for feeding the molten thermoplastic resin is one of a disk gate having the inner peripheral portion of the cavity as a gate and a ring gate having the outer peripheral portion of the cavity as a gate. Then, after removing burrs formed on the part corresponding to the gate after injection molding, before the adhesive is fixed to the slinger, the encoder is magnetized, and S poles and N poles are alternately arranged on the detection surface. Deploy.

According to the manufacturing method of the slinger with encoder and the rolling bearing unit with encoder of the present invention configured as described above, the encoder has a structure in which the encoder and the seal material are joined to the slinger, and the encoder has superior performance compared to the rubber magnet. Can be made of plastic magnet. Further, it is possible to sufficiently ensure the reliability regarding the adhesive strength of the encoder and the sealing material to the slinger.

[First example of embodiment]
A first example of the embodiment corresponding to claims 1, 2, and 6 will be described with reference to FIGS. In addition, since it is as having mentioned above about the structure of the rolling bearing unit with an encoder shown in FIG.1, 2, the description which overlaps is abbreviate | omitted or simplified, and the manufacturing method of the slinger with an encoder of this invention, and The explanation will focus on the parts that were not explained earlier.
In order to produce a slinger with an encoder provided with a sealing material by adhering and fixing an encoder 12a, which is a plastic magnet, and a rubber sealing material 18b provided with sealing lips 21c, 21d to the slinger 13a, first of the slinger 13a Of these, one side surface (the right side surface in FIGS. 1 and 2) of the outward ring portion 16, which is a joint surface to which the encoder 12 a is bonded and fixed, is subjected to air blasting, and this one side surface has a surface roughness. Ra is a rough surface of 1.3 to 1.6.

  Next, after washing the slinger 13a, a solvent diluted solution of an adhesive mainly composed of a phenol resin is sprayed on the joining surface, air-dried, and heated at a constant temperature to make the adhesive into a semi-cured state. To do. Next, in a state where the slinger 13a is set in a cavity of a mold for injection molding the encoder 12a, a plastic magnet material in which magnetic powder is mixed in a synthetic resin is pressurized in the cavity. Then, the encoder 12a, which is a plastic magnet, is injection-molded. At this time, a magnetic field is applied in the axial direction (performs magnetic field injection molding), and the magnetic powder in the plastic material constituting the encoder 12a is oriented (the length direction and the axial direction are made to coincide with each other). To increase the magnetic strength after magnetization. The injection-molded encoder 12a and the outward ring portion 16 of the slinger 13a are bonded and fixed by heat during molding. In order to further increase the adhesive strength, the adhesive may be further cured by heating.

In this way, if the encoder 12a is joined and fixed to the slinger 13a, then the slinger 13a (with the encoder 12a) is mainly composed of phenol resin, but is different from the previous adhesive. It is immersed in a solvent dilution solution of the adhesive, heated from the dilution solution, and then heated at a certain temperature, so that the adhesive adhered to the surface of the slinger 13a is in a semi-cured state. Next, the slinger 13a is set in a mold cavity for molding the sealing material 18b, and the unvulcanized rubber for constituting the sealing material 18b is vulcanized by compression molding or injection molding. This is bonded to the slinger 13a to form this sealing material 18b.
The adhesive for adhering the encoder 12a to the slinger 13a and the adhesive for adhering the seal material 18b are made of the material of these members 12a and 18b (plastic magnet material or rubber material). It is selected appropriately depending on whether there is any). In any case, a solvent that can be diluted with a solvent and realized in a semi-cured state and that has the ability to adhere by resin molding or vulcanization is used. Moreover, in order to improve environmental resistance, an adhesive agent can also be made into two or more layers.

  Finally, the encoder 12a bonded and fixed to the slinger 13a is opposed to a magnetizing yoke (not shown) to magnetize the encoder 12a in the axial direction, and one side surface in the axial direction which is a detected surface of the encoder 12a. In addition, the S pole and the N pole are alternately arranged at equal intervals in the circumferential direction. This magnetizing operation may be performed before the sealing material 18b is bonded to the slinger 13a. In this case, since this sealing material 18b is not provided, the encoder 12a is used as a magnetizing yoke in addition to an annular one that simultaneously magnetizes the detected surface of the encoder 12a over the entire circumference (performs one-shot magnetization). It is also possible to use a rotary magnetizing type that sequentially magnetizes while rotating.

[Second Example of Embodiment]
A second example of the embodiment corresponding to claims 1 and 3 to 6 will be described with reference to FIGS. In the case of this example, the outer peripheral edge portion of the outward ring portion 16 constituting the slinger 13b is bent axially opposite to the inner diameter side cylindrical portion 15 as shown in FIG. 4, or as shown in FIG. Folded outer diameter side bent portions 23, 23a are formed. And, when the slinger 13b and the encoder 12b are bonded and fixed, the outer diameter side bent portions 23 and 23a serve as a guide for aligning the centers of the slinger 13b and the encoder 12b. ing.

Such a structure is manufactured by the following process.
(1) After washing the slinger 13b, the slinger 13b is dipped in a solvent diluent of an adhesive mainly composed of a phenol resin, pulled up from the diluent, heated at a constant temperature, and then the adhesive. Is in a semi-cured state.
The adhesive may be applied to the slinger 13b only by spraying at a necessary portion (portion where the sealing material 18c is joined). However, in terms of cost, it is preferable to apply the entire surface by immersion in a diluent. .
(2) The slinger 13b is set in a cavity of a mold for molding the sealing material 18c, and unvulcanized rubber is vulcanized and bonded to the slinger 13b by compression molding or injection molding. 18c is molded.
(3) Separately from molding the sealing material 18c, the plastic magnet material is magnetic field injection molded by another mold. This another metal mold has at least one of a gate gate having a gate as an inner peripheral portion and a ring gate having an outer peripheral portion as a gate. After injection molding, burrs generated corresponding to the gate are removed from the inner or outer periphery of the obtained encoder 12b.
(4) The obtained encoder 12b is abutted against a magnetized surface of a magnetized yoke (not shown) and magnetized in the axial direction, and S poles and N poles are alternately arranged in the circumferential direction on the detected surface of the encoder 12b. And at equal intervals.
(5) After applying an adhesive to one axial side surface (the right side surface in FIGS. 4 and 5) of the outward ring portion 16 of the slinger 13b, the encoder 12b is guided by the outer side bent portions 23 and 23a. And the slinger 13b are concentrically overlapped, and then both the members 12b and 13b are bonded and fixed with an adhesive. The method of curing the adhesive is appropriately selected depending on the adhesive to be used, but an adhesive that cures at room temperature is preferable from the viewpoint of preventing misalignment and obtaining a high-quality slinger with an encoder.

[Third example of embodiment]
A third example of the embodiment corresponding to claims 1 and 3 to 6 will be described with reference to FIG. In the case of this example, a sealing material 18d having a single sealing lip 21d is joined and fixed to the outer peripheral edge portion of the outward ring portion 16 of the slinger 13a.
Such a structure is manufactured by the following process.
(1) After washing the slinger 13a, it is immersed in a solvent diluent of an adhesive mainly composed of a phenol resin, and after being pulled up from this diluent, heated at a constant temperature to make the adhesive semi-cured. .
(2) The slinger 13a is set in a cavity of a mold for molding the sealing material 18d, and unvulcanized rubber is vulcanized and bonded to the slinger 13a by compression molding or injection molding. The material 18d is formed.
(3) Separately from molding the sealing material 18d, a plastic magnet material is magnetic field injection molded by another mold. This another mold has a disk gate having an inner peripheral portion as a gate or a ring gate having an outer peripheral portion as a gate. After the injection molding, burrs generated corresponding to the gate are removed from the inner or outer peripheral edge of the obtained encoder 12b.
(4) The obtained encoder 12b is abutted against a magnetized surface of a magnetized yoke (not shown) and magnetized in the axial direction, and S poles and N poles are alternately arranged in the circumferential direction on the detected surface of the encoder 12b. And at equal intervals.
(5) After applying adhesive on one axial side surface (right side surface in FIG. 6) of the outward ring portion 16 of the slinger 13a, the center of the encoder 12b and the slinger 13a are aligned using a jig. The two members 12b and 13a are bonded and fixed with an adhesive. The method of curing the adhesive is appropriately selected depending on the adhesive to be used, but an adhesive that cures at room temperature is preferable from the viewpoint of preventing misalignment and obtaining a high-quality slinger with an encoder.

Including the examples of the embodiments described above, when the manufacturing method of the slinger with encoder and the rolling bearing unit with encoder of the present invention is carried out, the material of the plastic magnet constituting the encoder is not particularly limited. However, in consideration of molding and adhesion of this plastic magnet and adhesion to slinger after separate molding, it is preferable to use a magnet compound containing about 70 to 92% by weight of magnetic powder and using a thermoplastic resin as a binder. . As magnetic powder, ferrite such as strontium ferrite and barium ferrite, rare earth magnetic powder such as neodymium-iron-boron, samarium-cobalt, samarium-iron-nitrogen can be used, and the magnetic properties of ferrite are further improved. In order to achieve this, a material mixed with a rare earth element such as lanthanum can be used.

  In addition, when the content of the magnetic powder is less than 70% by weight, the magnetic properties are inferior, and it becomes difficult to perform multipolar magnetization in the circumferential direction at a fine pitch, which is not preferable. On the other hand, when the content of the magnetic powder exceeds 92% by weight, the amount of the binder becomes too small, the strength of the whole magnet is lowered, and at the same time, molding becomes difficult and practicality is lowered.

  The thermoplastic resin used as the binder of the plastic magnet constituting the encoder is preferably an injection-moldable one. Specifically, polyamide 6, polyamide 66, polyamide 12, polyamide 612, polyamide 610, polyamide 11, polyphenylene sulfide (PPS), modified polyamide 6T, polyamide 9T, modified polyamide 12 having a soft segment in the molecular structure, polyamide 612 having a soft segment in the molecular structure, a modified polyester resin having a soft segment in the molecular structure, Modified polystyrene having a soft segment in the molecular structure can be used. In addition, since there is a possibility that calcium chloride used as a snow melting agent adheres to the magnet portion together with water, polyamide 12, polyamide 612, polyamide 610, polyamide 11, polyphenylene sulfide (PPS), modified with low water absorption It is more preferable to use polyamide 6T, polyamide 9T, modified polyamide 12, modified polyester, and modified polystyrene as a resin binder.

  Furthermore, as a binder for preventing the occurrence of cracks due to a sudden temperature change (thermal shock) assumed in the usage environment of the rolling bearing unit, the modified polyamide 12, which improves bending flexibility and crack resistance by adding, Modified polyamide 612, modified polyester, modified polystyrene, or a mixture of modified polyamide 12 and polyamide 12, a mixture of modified polyamide 12 and polyamide 612, a mixture of modified polyamide 612 and polyamide 612, a mixture of modified polyester resin and polyester resin A mixture of modified polystyrene and polystyrene is most preferred. In addition, the thermal shock-resistant binder may be a combination of the above-described resin having no soft segment and another impact resistance improving material that plays the same role as the modified polyamide 12 or the like.

  Various other vulcanized rubber ultrafine particles can be used as other impact resistance improving materials. Specifically, it is selected from styrene butadiene rubber, acrylic rubber, acrylonitrile butadiene rubber, carboxyl modified acrylonitrile butadiene rubber, silicon rubber, chloroprene rubber, hydrogenated nitrile rubber, carboxyl modified hydrogenated nitrile rubber, and carboxyl modified styrene butadiene rubber. At least one kind of fine fine particles falling in the range of 30 to 300 nm in average particle diameter can be preferably used. When the average particle diameter is less than 30 nm, not only the production cost increases, but it is too fine to easily deteriorate, which is not preferable. On the other hand, when the average particle diameter exceeds 300 nm, the dispersibility deteriorates and it is difficult to uniformly improve the impact resistance.

  Among the vulcanized rubber ultrafine particles mentioned above, considering the deterioration during pellet production and actual magnet part molding, acrylonitrile butadiene rubber (nitrile rubber), carboxyl-modified acrylonitrile butadiene rubber, acrylic rubber, silicone rubber, hydrogenated nitrile rubber Carboxyl-modified hydrogenated nitrile rubber is preferred. Among them, those having an organic functional group such as a carboxyl group or an ester group in the molecular structure are more preferable because of their relatively strong interaction with the resin binder, specifically, carboxyl-modified acrylonitrile butadiene rubber. Acrylic rubber and carboxyl-modified hydrogenated nitrile rubber can be preferably used. These vulcanized rubber ultrafine particles prevent deterioration due to heat or oxygen, and diphenylamine-based anti-aging agents such as 4,4 ′-(α, α-dimethylbenzyl) diphenylamine, and 2-mercaptobenzimidazole and the like. It is good also as what contained the sub-aging inhibitor.

  In addition, other materials to be incorporated as impact resistance improvers include ethylene propylene non-conjugated diene rubber (EPDM), maleic anhydride-modified ethylene propylene non-conjugated diene rubber (EPDM), ethylene / acrylate copolymer, ionomer, glycidyl methacrylate. An ethylene copolymer containing 3 to 20% in the molecular structure can also be used. These compounds are in the form of pellets, which are fluidized and microdispersed in the binder when mixed with magnetic powder, thermoplastic resin, etc. and pelletized with an extruder.

  Further, the impact resistance improving material comprising the modified resin or vulcanized rubber ultrafine particles is added in an amount of 5 to 60% by weight, more preferably 10 to 40% by weight in the total amount of the binder combined with the thermoplastic resin. To do. When the amount added is less than 5% by weight, the amount is too small, and the effect of improving the impact resistance is small. On the other hand, when the addition amount exceeds 60% by weight, although the impact resistance is improved, the tensile strength and the like are reduced due to the decrease in the resin component, so the practicality is lowered.

  Furthermore, in order to prevent deterioration of the binder thermoplastic resin and impact resistance improving material (modified resin or vulcanized rubber ultrafine particles, etc.) due to heat, in addition to those originally added to the material, it has an antioxidant effect. It is preferable to add a high amine-based antioxidant because deterioration due to heat can be prevented. As the amine antioxidant used in this case, diphenylamine compounds such as 4,4 ′-(α, α-dimethylbenzyl) diphenylamine and 4,4′-dioctyldiphenylamine, N, N′-diphenyl-p- Phenylenediamine, N-isopropyl-N′-phenyl-p-phenylenediamine, N, N′-di-2-naphthyl-p-phenylenediamine, N, N′-bis (1-methylheptyl) -p-phenylenediamine P-phenylenediamine compounds such as N, N′-bis (1,4-dimethylpentyl) -p-phenylenediamine and N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine. Is preferred.

  The addition amount of the amine-based antioxidant is preferably about 0.5 to 2.0% by weight with respect to the combined weight of the binder weight and the antioxidant weight made of the thermoplastic resin and the impact resistance improving material. . When the added amount of the amine antioxidant is less than 0.5% by weight, the effect of improving the antioxidant is not sufficient, which is not preferable. On the other hand, when the addition amount of the antioxidant exceeds 2.0% by weight, the antioxidant effect is not improved any more, and the amount of magnetic powder and binder is reduced correspondingly, so that the magnetic properties are reduced. It is not preferable because it leads to a decrease in mechanical strength. In addition, in some cases, bloom or the like is caused on the surface of the molded product, which may adversely affect the adhesion with the sealing device, which is not preferable. With only a thermoplastic resin having no ordinary soft segment as a binder, the bending deflection at 23 ° C. (t = 3.0 mm, ASTM D790; span distance 50 mm) is in the range of 1 to 2 mm. By including an impact improvement material, the amount of deflection under the same conditions becomes about 2 to 15 mm. By having such excellent flexibility, crack resistance can be improved, and it is difficult for the encoder to be cracked or damaged even under severe use environments such as repeated high and low temperatures.

  As the magnetic powder, ferrite is most preferable in consideration of cost and oxidation resistance. When rare earths are used with priority on magnetic properties, the oxidation resistance is lower than that of ferrites. Therefore, in order to maintain stable magnetic characteristics over a long period of time, a surface treatment layer may be provided on the surface of the encoder exposed to the outside. Specifically, as the surface treatment layer used in this case, electroplating or electroless nickel plating, epoxy resin coating, silicon resin coating, fluorine resin coating, or the like can be used.

  In any case, the magnetic powder is properly used depending on the target magnetic characteristics, usage environment, and cost. If the magnetic properties are about 1.4 to 2.2 MGOe in terms of BHmax, a ferrite-based magnetic powder such as strontium ferrite can be sufficiently used. Further, in order to further improve the accuracy of rotational speed detection, when BHmax is set to about 2.2 to 5 MGOe, a hybrid of ferrite magnetic powder such as strontium ferrite and rare earth magnetic powder, or rare earth magnetic powder It is preferable to use only a blend.

  Further, as a material of the slinger or the metal core constituting the seal ring constituting the combined seal ring, magnetic stainless steel such as ferritic stainless steel (SUS430, etc.), martensitic stainless steel (SUS410, etc.) can be used. Furthermore, when higher corrosion resistance is required, a magnetic metal material such as SUS434, SUS444, or other high corrosion resistance magnetic ferritic stainless steel that has been improved by adding Mo or the like is suitable. In addition, since there is no active reaction such as vulcanization bonding that occurs in the case of rubber materials between the plastic magnet and the adhesive, there is a tendency that the bonding strength and the bonding durability against chemicals such as salt water are lowered. is there. Therefore, in order to increase the reliability of the adhesion between the plastic magnet and the adhesive, it is preferable to provide at least the uneven surface for improving the bonding force with the adhesive on the bonding surface of the plastic magnet. In this case, as a method of providing this fine unevenness, mechanical etching such as shot blasting or transfer of unevenness on the mold surface during press molding, as well as chemical etching of the surface once surface-treated with acid etc. You may do it. In any case, when a fine unevenness is provided on the joint surface of the plastic magnet, the bonding force between the plastic magnet and the slinger is improved based on the anchor effect. In addition, after forming a seal lip part by vulcanizing and bonding unvulcanized rubber to a slinger, when bonding and fixing a plastic magnet molded separately, the adhesion to the slinger among the plastic magnets A cured adhesive layer such as a phenolic resin for vulcanizing and bonding a rubber seal material may remain on the surface of the surface portion. However, in this case, an adhesive having an adhesive force is selected and used for both the remaining adhesive cured layer and the plastic magnet.

  Moreover, since the sealing material which joins each base end part to a slinger and a metal core is vulcanized-bonded to these slinger or a metal core, the mixing | blending based on a nitrile rubber is suitable as a material. If further heat resistance is required depending on the use environment, it is preferable to change the material to hydrogenated nitrile rubber, acrylic rubber, fluorine rubber, silicon rubber or the like. The vulcanization bonding temperature of rubber is appropriately determined in consideration of the type and composition of rubber and the melting point of the plastic magnet material constituting the encoder to be combined. Considering this point, it is preferable to select a material having a high melting point of about 200 ° C. as the plastic magnet material to be used. Specifically, polyamide 612, polyamide 610, modified polyamide 612, polyphenylene sulfide (PPS), modified polyamide 6T, polyamide 9T, and the like can be used as the thermoplastic resin as the main component of the binder of the plastic magnet. The sealing material constituting the seal lip is molded by injection molding or compression molding using unvulcanized rubber.

  In addition, as a molding method for plastic magnets, which are encoders, good magnetic properties can be obtained by using the magnetic field injection molding of the disk gate type or similar ring gate type, which does not generate welds that reduce mechanical strength. From the aspect of obtaining Of these, the disk gate method uses insert molding with a slinger as a core, or a plastic magnet alone as a separate body, with the inner peripheral portion of the cavity where the plastic magnet is to be made as a gate. In the ring gate method, the outer peripheral portion of a cavity in which a plastic magnet is to be made is a gate, and similarly, insert molding with a slinger as a core, or only a plastic magnet is molded separately. In any case, after the plastic magnet is molded, the gate and the runner portion are detached, and then the remaining portion of the gate portion is removed by cutting.

  In any case, the adhesive bonding of plastic magnets by insert molding with a slinger as the core is performed by insert molding a pre-baked adhesive layer on the slinger surface in a semi-cured state. Bonded with heat from. Furthermore, if the secondary heating is performed after the molding, the adhesive is completely cured and the bonding strength is further improved.

  Adhesives that can be used for molding adhesives can be diluted with a solvent, and the curing reaction proceeds in almost two stages, such as phenol resin adhesives and epoxy resin adhesives, which have heat resistance, chemical resistance, It is preferable in consideration of handling properties. Of these, those used as rubber vulcanizing adhesives are suitable as phenolic grease-based adhesives, and the composition is not particularly limited, but novolac-type phenolic resins and resol-type phenolic resins, and hexamethylene A solution obtained by dissolving a curing agent such as tetramine in methanol or methyl ethyl ketone can be used. Moreover, in order to improve adhesiveness, what mixed the novolak-type epoxy resin with these can also be used preferably.

On the other hand, as the epoxy resin adhesive, a one-pack type epoxy adhesive that can be diluted into a solvent can be preferably used as a stock solution. This one-pack type epoxy adhesive, after evaporating the solvent, becomes a semi-cured state on the surface of the slinger at an appropriate temperature and time so as not to be washed away by high temperature and high pressure melted grease during insert molding. The resin is completely cured by heat from the resin during molding and secondary heating.
In addition, the one-pack type epoxy adhesive used for molding adhesion is composed of at least an epoxy resin and a curing agent, and the curing agent hardly undergoes a curing reaction at room temperature, for example, becomes a semi-cured state at about 80 to 120 ° C. Use the one where the thermosetting reaction proceeds completely by applying high-temperature heat of ˜180 ° C. Such adhesives include other epoxy compounds used as reactive diluents, curing accelerators that improve the thermosetting speed, inorganic fillers that have the effect of improving heat resistance and resistance to distortion, stress Cross-linked rubber fine particles or the like that improve the flexibility of deformation when added may be added.

  Also, the encoder, which is a plastic magnet formed separately, and the slinger previously joined with a sealing material provided with a seal lip are joined by an adhesive with the centers of the encoder and the slinger aligned. . Specifically, the inner diameter (inner circumference) of the slinger with high accuracy is fixed to a jig so that it does not move, and the inner diameter (inner circumference) is fixed to another jig so that it does not move. The encoder is attached with an adhesive. The center of the slinger and the encoder coincide with each other in a state in which a convex portion is provided on one jig and a concave portion is provided on the other jig so that the centers coincide when bonding is performed. To do. The adhesive is applied in advance to at least one of the slinger and encoder to be bonded. The bonding operation with the adhesive is performed until the slinger and the encoder do not move in a state where the centers of the slinger and the encoder are matched by the pair of jigs. At this time, if heating or the like is performed in order to advance the curing reaction of the adhesive, the encoder, which is a plastic magnet having a larger linear expansion coefficient than that of a metal, may move in the jig and shift its center. . For this reason, it is preferable to use an adhesive whose curing reaction proceeds at room temperature.

Examples of such an adhesive that can be cured at room temperature include a moisture curable adhesive, a two-component mixed adhesive, and a photocurable adhesive. Among these, examples of the moisture curable adhesive include a one-component polyurethane adhesive, a one-component modified silicone adhesive, and a cyanoacrylate instantaneous adhesive. Two-component mixed adhesives consisting of a main agent and a curing agent include two-component epoxy adhesives, two-component modified silicone adhesives, two-component polyurethane adhesives, two-component acrylic adhesives, etc. is there. Examples of the photocurable adhesive include a photocurable acrylic resin adhesive. Of these, the two-component epoxy adhesive is the most suitable as an adhesive having sufficient reliability in the application of the present invention and having heat resistance, adhesive strength, chemical resistance, etc. all at a certain level or higher. Is preferred. In addition to the above, a one-pack type epoxy adhesive that can be cured at a relatively low temperature of 60 to 80 ° C. also depends on a difference in linear expansion coefficient (metal slinger and plastic magnet magnet part) at the time of adhesion. It can be used because it can minimize misalignment and has high adhesion and chemical resistance.
The adhesive bonding between the encoder formed separately and the slinger pre-bonded with the rubber sealing material is not limited to the above-described method of preventing the center from being shifted using a jig. As in the second example of the embodiment shown in FIG. 4, the outer diameter side bent portion can be provided on the surface side of the slinger where the encoder is installed.

この表１中の材料は、具体的には次の通りのものである。 An experiment conducted for confirming the curing of the present invention will be described. An encoder was manufactured under the conditions shown in Table 1 below, and its performance was measured.

The materials in Table 1 are specifically as follows.

Sr ferrite: Anisotropy Sr ferrite for magnetic field orientation, Fero TOP FM-201 (manufactured by Toda Kogyo Co., Ltd.)
PA12: PA12 powder P3012U (containing hindered phenolic antioxidant, manufactured by Ube Industries)
PA612: PA612 Diamide DX9305 (containing antioxidant, manufactured by Daicel Degussa)
Modified PA12: UBEPAE1210U (containing hindered phenol antioxidant, manufactured by Ube Industries, Ltd.)
Silane coupling agent: γ-aminopropyltriethoxysilane, A-1100 (manufactured by Nihon Unicar)
Amine-based antioxidants: N, N′-diphenyl-p-phenylenediamine, Nocrack DP (manufactured by Ouchi Shinsei Chemical Co., Ltd.)

Regarding the material as described above, with respect to Example 1, a slinger with an encoder was formed by the structure and method of the second example of the embodiment shown in FIG. In addition, at the time of magnetic field injection molding, reversal demagnetization was performed during cooling in the mold, and the magnet was demagnetized. Then, after demagnetizing the surface magnetic flux density to 2 mT or less using a demagnetizer, the gate portion was removed by cutting.
In addition, a room temperature curable two-component epoxy adhesive (Loctite E-30CL manufactured by Nippon Loctite Co., Ltd.) is applied to the magnet joint surface of the slinger 13b, and then the encoder 12b preliminarily magnetized with the multipolar magnet is used as the slinger 13b. The outer diameter side bent portion 23 formed on the outer peripheral edge portion of the outward circular ring portion 16 constituting the above was used as a guide and adhered in a state in which the centers were matched (left until the adhesive was cured). In addition, in order to accelerate | stimulate hardening, it was left to stand in a 50 degreeC thermostat for 1 hour.

Further, with respect to Example 2, a slinger with an encoder was formed by the structure and method of the first example of the embodiment shown in FIG. The slinger 13a is made of SUS430, and a phenolic resin adhesive hardened layer is interposed on the joint surface of the encoder 12a.
As an adhesive for adhering the slinger 13a and the encoder 12a, a phenol resin adhesive (Metaloku N-15 manufactured by Toyo Chemical Laboratories) was used. The semi-curing temperature was 120 ° C. and the standing time for adhesion was 30 minutes. Further, secondary curing was performed at 150 ° C. for 1 hour.
As a result, sufficient strength could be secured in any of the examples.

  The present invention is not limited to the slinger with an encoder incorporated in the inner ring rotation type rolling bearing unit as shown in the figure, but can also be applied to the manufacture of the slinger with encoder incorporated in the outer ring rotation type rolling bearing unit. The slinger incorporated into the outer ring rotating type rolling bearing unit is composed of an outer diameter side cylindrical portion and an inward ring portion bent radially inward from the axial end portion of the outer diameter side cylindrical portion.

Sectional drawing which shows one example of the rolling bearing unit for wheel support incorporating the 1st example of the slinger with an encoder used as the object of this invention. The A section enlarged view of FIG. The figure similar to FIG. 2 which shows an example of the structure which remove | deviates from the object of this invention. The figure similar to FIG. 2 which shows the 2nd example of the slinger with an encoder used as the object of this invention. The fragmentary sectional view which shows another example of the shape of a slinger. The figure similar to FIG. 2 which shows the 3rd example of the slinger with an encoder used as the object of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rolling bearing unit for wheel support 2 Outer ring 3 Hub 4 Ball 5 Hub body 6 Inner ring 7 Fixed flange 8 Rotating flange 9 Internal space 10 Seal ring 11 Combination seal ring 12, 12a, 12b Encoder 13, 13a, 13b Slinger 14, 14a Seal Ring 15 Inner diameter side cylindrical part 16 Outward ring part 17 Core metal 18, 18a, 18b, 18c, 18d Sealing material 19 Outer diameter side cylindrical part 20 Inward ring part 21a, 21b, 21c, 21d Seal lip 22 Sensor 23, 23a Outer diameter side bent part

Claims (6)

  Between the fixed-side raceway and the rotation-side raceway arranged concentrically with each other, and the raceway surfaces provided on the mutually opposing surfaces of these raceways, the rolls are arranged while being held in a cage. A plurality of rolling elements, a sealing device for closing an end opening of an internal space provided with the rolling elements, and a magnetic metal constituting the sealing device in a state of being fixed to a part of the rotating raceway An encoder provided with a plastic magnet and an encoder in which S poles and N poles are alternately arranged on a detection surface, which is supported concentrically with the slinger on a part of a plate slinger. A method of manufacturing a slinger with an encoder constituting a rolling bearing unit, wherein an adhesive is applied to a portion of the slinger where the encoder is to be installed, and then the slinger is used for injection molding the encoder. Mold A plastic magnet material in which magnetic powder is mixed in a thermoplastic resin is sent into the cavity in a molten state while applying a magnetic field, and the encoder and the slinger are bonded and fixed to the slinger. After applying another adhesive, a rubber uncured seal lip and a slinger to which the encoder is joined and fixed are combined, and then the seal lip and the slinger are vulcanized and bonded together. A method of manufacturing a slinger with an encoder, wherein the base portion of the seal lip is bonded and fixed to the encoder.   The gate that feeds the molten thermoplastic resin into the cavity of the mold for injection molding of the encoder is a ring gate provided on the outer periphery of this cavity, and the part corresponding to this ring gate after injection molding 2. The method of manufacturing a slinger with an encoder according to claim 1, wherein after the burrs formed on the surface are removed, the encoder is magnetized and S poles and N poles are alternately arranged on the detection surface.   Between the fixed-side raceway and the rotation-side raceway arranged concentrically with each other, and the raceway surfaces provided on the mutually opposing surfaces of these raceways, the rolls are arranged while being held in a cage. A plurality of rolling elements, a sealing device for closing an end opening of an internal space provided with the rolling elements, and a magnetic metal constituting the sealing device in a state of being fixed to a part of the rotating raceway An encoder provided with a plastic magnet and an encoder in which S poles and N poles are alternately arranged on a detection surface, which is supported concentrically with the slinger on a part of a plate slinger. A method of manufacturing a slinger with an encoder that constitutes a rolling bearing unit, wherein an adhesive is applied to the slinger, and after the slinger and a rubber-made unvulcanized seal lip are combined, Seal Ri The encoder is made separately by bonding and fixing the base of the seal lip to a part of the slinger, and then injection-molding a plastic magnet material in which magnetic powder is mixed in a thermoplastic resin. A method of manufacturing a slinger with an encoder, wherein the slinger is bonded and fixed to the slinger with another adhesive.   The manufacturing method of the slinger with an encoder according to claim 3, wherein the another adhesive is a room temperature curable adhesive capable of being bonded at room temperature.   The gate that feeds the molten thermoplastic resin into the cavity of the mold for injection molding of the encoder is a disk gate that uses the inner periphery of this cavity as the gate, and the ring that uses the outer periphery of this cavity as the gate. After removing the burrs formed on the part corresponding to the gate after injection molding, and before adhering and fixing to the slinger, the encoder is magnetized and an S pole is formed on the surface to be detected. The manufacturing method of the slinger with an encoder as described in any one of Claims 3-4 which arrange | positions an N pole and an N pole alternately. Between the fixed-side raceway and the rotation-side raceway arranged concentrically with each other, and the raceway surfaces provided on the mutually opposing surfaces of these raceways, the rolls are arranged while being held in a cage. A plurality of rolling elements, a sealing device for closing an end opening of an internal space provided with the rolling elements, and a magnetic metal constituting the sealing device in a state of being fixed to a part of the rotating raceway A part of a plate slinger is provided with an encoder, which is made of a plastic magnet and is arranged concentrically with the slinger over the entire circumference, with S poles and N poles arranged alternately on the detection surface. A method for manufacturing a rolling bearing unit with an encoder, wherein the slinger, the encoder, and a seal lip are joined and fixed by the method for manufacturing a slinger with encoder according to any one of claims 1 to 5. Rolling Method of manufacturing a bearing unit.

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