JPH0915256A - Hub unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hub unit which is able to secure an excellent rust- preventative effect without entailing any damage to the quench hardening of a raceway part, and constitutes a revolution number detector integrally formed out of a pulser ring and an outer ring hub as one body. SOLUTION: In this hub unit forming rugged teeth constituting a pulser ring on the peripheral surface and consisting of an outer ring hub 1 having one side of bearing raceway surfaces formed on an inner circumferential surface, an inner ring forming the other side of bearing raceway surfaces on an outer circumferential surface and inserting a shaft into this inner circumferential surface, and a rolling element to be set up in a space between both these inner and outer rings, a film 1b containing a thermosetting resin is formed in a rugged teeth part 11. This thermosetting resin consists of epoxy resin and melamine resin, and further polytetrafluoroethylene (PTPE) is added, thereby, revolution number detection is maintainable highly accurately. With this polytetrafluoroethylene added, the coating film 1b is made hard to be broken against flying stone.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hub unit which constitutes a wheel of a vehicle or the like and a detecting device for detecting the rotational speed of the wheel, and in particular, a hub unit capable of preventing the rotational speed detection error due to rust or the like. Regarding

[0002]

BACKGROUND OF THE INVENTION When activating an anti-skid brake system (ABS) in a motor vehicle, the rotational speed of the wheels is detected and measured. As shown in FIG. 3, a conventional rotation speed detecting device rotates with a wheel and has a predetermined uneven tooth 32 on its outer peripheral surface.
(Outer ring hub 31 forming a (pulsar ring) and forming one bearing raceway surface 33 on the inner peripheral surface, and the other bearing raceway surface 42 on the outer peripheral surface, and a fixed shaft (not shown) on the inner peripheral surface 43.
Of the inner ring 41 into which the outer ring is fitted and inserted, and the rolling elements 50 (balls) arranged between the outer ring and the inner ring. Also, there is known one in which the pickup sensor 51 is arranged oppositely (Japanese Patent Laid-Open No. 2-299902).

The pickup sensor 5 is arranged so as to oppose the concave and convex teeth 32 forming the pulsar ring of the outer ring hub 31.
Although various types have been proposed in the related art, basically, there are uneven teeth 3 which have a magnetic circuit and are generated as the wheel rotates.
The change in the magnetic flux density in the two parts is captured as accurately as possible.

[0004]

By the way, when rust occurs on the outer wheel hub 31 which constitutes the wheel rotation speed detecting device, there are often troubles such as the wheel cannot be removed. Further, the uneven teeth 32 formed on the outer ring hub 31, that is, the pulsar ring portion, is
In some cases, the influence of rust is larger than that of the other portions of 1, and the error in the detected pulse number becomes large. However, when the uneven teeth 32 forming the pulsar ring are formed integrally with the outer ring hub 31, it is extremely difficult to perform rust prevention treatment. That is, when the rustproofing process is performed, the quenching of the track portion is restored. Further, if rustproofing treatment is performed before quenching the track portion, there is a problem that the rustproofing effect is impaired by quenching.

Therefore, an object of the present invention is to solve the above-mentioned technical problems, and in a hub unit having an outer ring hub in which a pulsar ring portion and a raceway portion are integrally formed, quenching is not impaired and an excellent rust preventive effect is obtained. It is to provide a hub unit obtained.

[0006]

In order to achieve the above object, a hub unit according to a first aspect of the present invention has an outer peripheral surface having concavo-convex teeth forming a pulsar ring, and an inner peripheral surface having one bearing raceway surface. The formed outer ring hub, the inner ring on which the other bearing raceway surface is formed on the outer peripheral surface and the shaft is fitted on the inner peripheral surface, and
A hub unit including rolling elements arranged between the inner races is characterized in that a film containing a thermosetting resin is formed on the irregular tooth portions.

According to the structure of the invention according to claim 1,
In general, a film containing a thermosetting resin can be formed at a temperature lower than the tempering temperature of steel, which is a material of the outer ring hub, so that the effect of the quenching treatment is maintained even after the quenching treatment. be able to. Further, since the above-mentioned film protects the uneven tooth portion from water and the like, it can exhibit an excellent rust preventive effect.

A hub unit according to a second aspect is the hub unit according to the first aspect, wherein the thermosetting resin is an epoxy resin. According to the configuration of the invention according to claim 2, claim 1
In addition to the function of the invention according to, the epoxy resin, which is the thermosetting resin described above, is strong and stable by taking a three-dimensional network structure during thermosetting, so that the epoxy resin has excellent strength. The resin-containing coating can sufficiently protect the uneven teeth even with a thin film thickness, and can reliably prevent the uneven teeth from being rusted due to the stability.

A hub unit according to a third aspect of the present invention is the hub unit according to the first aspect, wherein the thermosetting resin is an epoxy resin or a melamine resin. According to the configuration of the invention of claim 3, in addition to the function of the invention of claim 1, as described in the function of the invention of claim 2, the epoxy resin, which is the thermosetting resin, is used. The film containing satisfactorily protects the uneven teeth even with a thin film thickness, and can reliably prevent the occurrence of rust on the uneven teeth. In addition, since the bond density of the network structure of the epoxy resin becomes higher by the addition of the melamine resin during thermosetting, the strength of the thermosetting resin is further improved. As a result, the film containing the thermosetting resin can withstand a larger external force and can be more difficult to be damaged.

A hub unit according to a fourth aspect is the hub unit according to the second or third aspect, wherein the thermosetting resin further comprises PTFE (polytetrafluoroethylene). It is a thing. According to the configuration of the invention of claim 4 above, in addition to the function of the invention of claim 2 or 3, the PTF is added to the thermosetting resin.
Addition of E improves the flexibility of the thermosetting resin, so the coating containing the thermosetting resin has improved impact resistance, and the coating may be chipped or cracked when flying stones collide with the coating. It's hard to do. That is, a film having excellent so-called chipping resistance can be obtained.

In the present invention, a zinc phosphate chemical conversion coating is applied to the entire outer ring hub surface as a base treatment.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 (A) is an axial sectional view of an outer ring hub 1 that constitutes a hub unit of the present invention,
1B is an enlarged view of the P portion of FIG. 1A, and FIG. 2 is a view of the outer ring hub 1 as seen from the direction of the arrow Q in FIG. The flange portion 1f of the outer ring hub 1 is attached and fixed to the rotating wheel (not shown) side. Concavo-convex teeth 11 are formed as a pulsar ring at one end of the outer ring hub 1, and a pickup sensor (which is installed on the fixed side) 2 is arranged at a predetermined interval on the concavo-convex teeth 11. To be done.

The outer ring hub 1 is usually manufactured by forging, and the uneven teeth 11 are formed at this time. After forging, quenching and tempering are performed, and the vicinity of the bearing raceway surfaces 11, 12 is hardened to have a predetermined hardness. A feature of the hub unit of the present invention is that a zinc phosphate chemical conversion coating 1a and a thermosetting resin coating 1b to be described later are formed on the surface in the vicinity of the uneven teeth 11 to form a double-layer coating. Has been formed. The double-layered coating may be formed only on at least the portion where the uneven teeth 11 are formed and which affects the sensitivity of the pickup sensor 2.

The films 1a and 1b are formed as follows. That is, after the above quenching and tempering, the outer ring hub 1 is subjected to a zinc phosphate film conversion treatment as a base treatment, for example, by a dipping method, and the zinc phosphate film 1a is formed on the entire surface of the outer ring hub 1. It is formed. Next, a coating process is performed on the concavo-convex teeth 11 and the vicinity thereof. That is, on the zinc phosphate coating 1a,
A thermosetting resin coating is applied by spraying. In addition,
The number of times of application is not particularly limited as long as a predetermined film thickness can be formed. Then, the hardening treatment of the coating film by baking is performed under a predetermined condition of being kept at a predetermined temperature lower than the tempering temperature for a predetermined time (for example, holding at 150 ° C. for 20 minutes), so that the thermosetting resin film 1b has a predetermined temperature. The film thickness is, for example, 25 μm.

Here, the film thicknesses of the film 1a and the film 1b are set in consideration of the following points. That is, since the thick film thickness lowers the detection sensitivity of the pickup sensor 2, the film thickness is set so as not to interfere with the rotation detection by the pickup sensor 2. The film thickness should be thick enough to ensure sufficient rust prevention. If the film 1b is thick, the film 1b is considered to be less flexible, so that the film can have flexibility, and the film is not likely to be cracked or chipped when a flying stone collides with it. . For example, the film thickness of the coating film 1b is preferably set to 15 to 35 μm, and optimally about 25 μm, as shown in Table 2 of Examples described later.

The bearing raceways 12, 13 of the outer ring hub 1
The film 1a formed on the surface is removed by grinding. An example of the preferable composition of the above-mentioned thermosetting resin coating material is shown below in terms of weight ratio (%). Epoxy resin 41-45% Melamine resin 3 to 6% PTFE 5 to 10% coloring pigment (carbon, aniline) 2-3% extender pigment (SiO ₂₎ 5 to 6% solvent (methyl isobutyl ketone) 40% Thus Since the coating 1b containing the thermosetting resin can be formed by hardening at a temperature lower than the tempering temperature of the steel which is the material of the outer ring hub 1, even if it is performed after the quenching treatment, the raceway portion The effect of the quenching treatment can be maintained.

Further, since the double-layered coating consisting of the coating 1a and the coating 1b covers the surface of the uneven tooth 11, the uneven tooth 11 can be protected from water, the atmosphere, etc., and an excellent anticorrosive effect can be obtained. Can be demonstrated. Furthermore, the zinc phosphate coating 1a has the effect of improving the adhesion between the thermosetting resin coating 1b and the base metal, and significantly enhancing the rust prevention effect.

Since the epoxy resin, which is a thermosetting resin, is strong and stable due to the three-dimensional network structure during thermosetting, the coating film 1b has excellent strength due to the excellent strength of the epoxy resin. Even if the thickness is thin, the uneven teeth 11 can be sufficiently protected, and the stability of the epoxy resin can reliably prevent the uneven teeth 11 from being rusted. Therefore, the coating film 1b described above has a sufficient thickness to maintain the sensitivity of the pickup sensor 2 even if the tooth 1 is uneven.
1 can be protected.

Further, by adding the melamine resin to the thermosetting resin in addition to the epoxy resin, the bond density of the network structure of the epoxy resin of the thermosetting resin becomes higher, The strength of the thermosetting resin is further improved. Furthermore, by adding PTFE, the flexibility of the thermosetting resin is improved, and the impact resistance of the coating 1b against the collision of flying stones is improved. As a result, the coating 1b containing the thermosetting resin is chipped or cracked. It becomes difficult to do so, and the rust preventive effect becomes more excellent (see Table 1 of the following examples).

Therefore, even if the film 1b is exposed to water or the like in addition to flying stones, the corrugated teeth 11 are sufficiently protected from moisture by the film 1b, so that rust can be prevented. Further, since the coating 1b containing the thermosetting resin is flexible, it is possible to prevent the coating 1b from being damaged by assembly, transportation, etc. before the hub unit is mounted on the vehicle, and without any special precautions. You can handle this hub unit.

Further, the film formation by the above coating can be realized at low cost. Therefore, in this hub unit, the detection accuracy of the rotation detection can be maintained high by maintaining the sensitivity of the pickup sensor 2, and due to the excellent rust prevention effect, the detection error of the rotation detection due to the generation of rust can be prevented. Can be suppressed. Therefore, by using this hub unit, rotation can be accurately detected. Furthermore, since the quenching effect of the raceway portion can be maintained, it is possible to realize a hub unit in which the bearing portion and the pulsar ring are integrated while maintaining the same performance as a hub unit in which the bearing portion and the pulsar ring are separated. .

Although the paint has the above-mentioned composition as an embodiment of the present invention, the present invention is not limited to this. For example, an acid catalyst or the like may be added as a curing accelerator. In this case, the curing temperature of the thermosetting resin can be lowered, the curing time can be shortened, and the effect on the quenching effect of the orbital portion can be further reduced. In addition, various design changes can be made without changing the gist of the present invention.

[0023]

[Examples] Sample pieces of various test examples and comparative examples corresponding to the above-mentioned embodiment were prepared, and cracking and chipping of the film due to collision of stepping stones and the like (referred to as "chipping resistance"), And the test for rust prevention was conducted under the following conditions. Test conditions for chipping resistance Tester Claverometer (Suga Test Instruments Co., Ltd. J
A-400) Chip material Basalt (No. 6 crushed stone) 1 kg Pressure 0.4 MPa Rust-proof test conditions Salt spray test according to JIS Z2371 (1000 hours) The contents and test results of each sample are shown in Table 1 and Table 2 below. Show. The test results were evaluated on the basis of suitability when applied to this hub unit, and evaluated in three grades of "good", "normal" and "poor". The curing condition of the coating film is 150 degrees for 20 minutes.

Table 1 shows the case where the composition of the film was variously changed with the same film thickness.

[0025]

[Table 1]

As shown in Table 1, Test Examples 1 to 4 in which the composition of the film was an epoxy resin, or an epoxy resin and a melamine resin, were totally good as compared with Comparative Example 1. showed that. Further, from the comparison between Test Examples 1 and 2 and the comparison between Test Examples 3 and 4, when PTFE is added to the above thermosetting resin as an additive, the film is less likely to be chipped even if it receives a stepping stone. You can judge that. This is PTF
It is presumed that the impact resistance of the film was increased due to the increase in flexibility of the thermosetting resin due to E.

Table 2 shows the case where the film thickness is variously changed with the same film composition.

[0028]

[Table 2]

As shown in Table 2, Test Example 1,
Nos. 5 and 6 showed totally good results with respect to Comparative Examples 2 and 3. Further, from the comparison between Test Examples 1, 5 and 6 and Comparative Examples 2 and 3, it is considered that the film thickness of the film affects the chipping resistance, and it is desirable to set the film thickness within a predetermined range. It is presumed that if the film thickness is too thin, the strength of the film is insufficient, and if the film thickness is too large, the flexibility is insufficient, and therefore the film is likely to be cracked or chipped when receiving a stepping stone. It has also been shown that a film having a good rust preventive property requires a certain thickness.

[0030]

According to the invention of claim 1, the hardening effect of the outer ring hub is obtained by forming a film containing a thermosetting resin on the uneven tooth portion after quenching at a temperature lower than the tempering temperature of steel. While maintaining the above, it is possible to exert an excellent rust prevention effect. According to the invention of claim 2, in addition to the effect of the invention of claim 1, due to the excellent strength and stability of the epoxy resin, the film can sufficiently protect the uneven teeth even with a thin film thickness. Therefore, it is possible to reliably prevent the generation of rust on the uneven teeth. Therefore, the above film can exert a sufficient anticorrosive effect even with a film thickness that can maintain the sensitivity of the pickup sensor, and can maintain rotation detection with high accuracy.

According to the invention of claim 3, in addition to the effect of the invention of claim 1, the thermosetting resin is obtained by adding a melamine resin to an epoxy resin,
In addition to the excellent strength and stability of epoxy resin, its strength is further improved. Therefore, the above-mentioned film can exhibit a further excellent anticorrosion effect even with a film thickness that can maintain the sensitivity of the pickup sensor, and can maintain rotation detection with high accuracy.

According to the invention of claim 4, in addition to the effect of the invention of claim 2 or 3, by further adding PTFE to the thermosetting resin, a film containing the thermosetting resin is obtained. Since the flexibility of the coating is increased and the impact resistance of the coating is improved, the coating is less likely to be cracked or chipped when the flying stone collides, and the rust prevention effect is further improved.

[Brief description of the drawings]

FIG. 1A is an axial cross-sectional view of an outer ring hub of a hub unit according to an embodiment of the present invention, and FIG.
FIG. 3 is an enlarged cross-sectional view of a main part of a concave and convex tooth portion of a P portion in FIG.

FIG. 2 is a side view of the outer ring hub 1 as seen in the direction of arrow Q shown in FIG.

FIG. 3 is a front sectional view of a conventional hub unit.

[Explanation of symbols]

 1 Outer Ring Hub 1a Zinc Phosphate Conversion Film 1b Thermosetting Resin Film 11 Concavo-convex teeth 12,13 Bearing raceway surface 31 Outer-ring hub 32 Concavo-convex tooth 41 Inner ring 33,42 Bearing raceway surface 50 Rolling element

Claims (4)

[Claims] 1. An outer ring hub having an outer peripheral surface having concavo-convex teeth forming a pulser ring and having one bearing raceway surface formed on an inner peripheral surface, and the other bearing raceway surface formed on an outer peripheral surface on an inner peripheral surface. A hub unit comprising an inner ring into which a shaft is fitted and a rolling element arranged between the outer ring and the inner ring, wherein a film containing a thermosetting resin is formed on the uneven tooth portion. 2. The hub unit according to claim 1, wherein the thermosetting resin is an epoxy resin. 3. The hub unit according to claim 1, wherein the thermosetting resin is an epoxy resin or a melamine resin. 4. The hub unit according to claim 2 or 3, wherein the thermosetting resin further comprises PTFE (polytetrafluoroethylene).