JPH0914399A - Resin pulley - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize oscillation of a belt at the time when the belt travels by making a surface of a belt contact part making contact with the belt a skin layer removed surface from which a skin layer to be formed at the time of molding is removed. SOLUTION: Three lines of rib grooves 2, 2,... as a belt contact part making a sectionally V letter shaped are peripherally provided on an outer periphery of a rim part 1 of a resin pulley. The resin pulley is molded of a resin material mainly containing phenol resin by a die. At this time, an organic fiber material and a spherical inorganic filler are contained in the resin material at compounding proportion of 20-80wt.% to give measurement stability, rigidity, abrasion resistance, impact resistance strength, etc. Additionally, the whole surface including each of rib grooves 2 of the resin pulley is made a skin layer removed surface from which a skin layer 3 formed at the time of molding is removed. Additionally, surface precision of the resin pulley is made Rmax <=20μm. Consequently, it is possible to avoid generation of belt oscillation caused by a belt (t) being adhered on the resin pulley.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin pulley which is used in, for example, an auxiliary drive of an automobile engine and around which a friction transmission belt such as a V-ribbed belt is wound, and more particularly to a technique for reducing belt vibration.

[0002]

2. Description of the Related Art Conventionally, a metal pulley has been generally used in, for example, an auxiliary drive of an automobile engine.
It has been pointed out that the unevenness of the pulley surface causes the belt to be worn or the rubber of the belt to stick. Under these circumstances, in recent years, the pulleys have been made of resin. This resinization also includes the aim of weight reduction.

When a general-purpose thermoplastic resin is used as a material for the pulley when the pulley is made of resin, there is a problem that the pulley generates heat and melts as the belt runs. On the other hand, if a thermoplastic super engineering plastic is used as the pulley material, the cost is too high and the versatility is lacking.

Therefore, as described in, for example, Japanese Patent Application Laid-Open No. 4-371807, the durability at high temperature is improved by mixing aramid fiber and glass component (glass fiber or glass powder) with phenol resin. A resin pulley that can be used has been proposed. Although not a pulley, a gear made of phenol resin is also disclosed in Japanese Patent Laid-Open No. 7-
It is known from Japanese Patent No. 113458. It is said that, by mixing aramid fibers in the phenol resin, the belt wear amount is not increased as in the case of mixing inorganic fibers such as glass fibers.

[0005]

However, in the above-mentioned conventional resin pulley made of phenolic resin, when the belt is actually wound and used, a large friction is generated between the belt and the rubber of the belt. It was found that the adhesion caused considerable belt vibration.

Further, since it is a metal mold product, a parting line by a split mold may be formed on the contact surface with the belt. In that case, the belt vibration may be caused by the unevenness of the parting line. Be encouraged.

The present invention has been made in view of the above points, and its main purpose is to perform a proper surface treatment on the resin pulley when obtaining a mold product of a resin pulley made of a phenol resin. By doing so, the coefficient of friction of the pulley surface can be appropriately lowered, and the unevenness of the parting line can also be made small, so that excellent quietness with little belt vibration during belt running can be obtained. .

[0008]

In order to achieve the above object, in the invention of claim 1, the presence of a skin layer formed on the surface of the pulley at the time of molding by a mold increases the friction coefficient with the belt. Based on this, the skin layer was removed by means such as blasting and surface grinding, and at the same time, the unevenness of the parting line could be smoothed at the same time.

Specifically, the present invention is premised on a resin pulley which is formed by molding a phenol resin material in a mold and which is used to wind a belt and transmit torque between the belt and the belt. Is.

The above-mentioned phenol resin material is made by mixing an organic fiber material or a spherical inorganic filler into the phenol resin. In addition, at least the surface of the belt contact portion that comes into contact with the belt is the skin layer-removed surface from which the skin layer formed during the molding has been removed.

In the resin pulley formed by molding the phenol resin material with the above-mentioned structure, at least the surface of the belt contact portion of the pulley is the skin layer-removed surface with the skin layer removed. The contact of the skin layer with the belt is avoided when the vehicle runs while being wound around the resin pulley. Therefore, the coefficient of friction between the belt and the resin pulley is lower than when the as-molded belt contact part is in contact with the belt, and belt vibration occurs due to the rubber of the belt sticking to the resin pulley. Is avoided.

Further, when the skin layer is removed, the unevenness of the parting line due to the split mold becomes small at the same time, so that the belt vibration due to the unevenness of the parting line is prevented from occurring.

Since the above-mentioned phenol resin material is mixed with an organic fiber material or a spherical inorganic filler,
Compared to the case where inorganic fibers such as glass fibers or needle-like inorganic fillers such as glass powder are mixed, dimensional stability, rigidity, abrasion resistance, impact resistance, etc. are achieved without shortening the belt life. About, it becomes possible to reinforce the resin pulley.

According to a second aspect of the present invention, in the above first aspect of the invention, the surface roughness of the skin layer-removed surface is Rmax ≤20.
μm.

With the above structure, since the surface roughness of the skin layer-removed surface of the resin pulley is Rmax ≤20 μm,
The belt is less likely to be abraded due to the removal of the skin layer. Therefore, not only the vibration of the belt can be reduced but also the life of the belt can be shortened.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a main part of a resin pulley according to an embodiment of the present invention. This resin pulley is used to wind a V-ribbed belt t having three ribs in an accessory drive device of an automobile engine. The outer periphery of the rim portion 1 has a V-shaped cross section. Rib groove of three stripes 2 as a belt contact part
2, ... are laid around.

The resin pulley is formed by molding a resin material mainly composed of phenol resin in a mold. At that time, in order to impart dimensional stability, rigidity, abrasion resistance, impact resistance and the like, the resin material is mixed with an organic fiber material and a spherical inorganic filler in a mixing ratio of 20 to 80 wt%. .

Examples of the above-mentioned organic fiber materials include non-melt fibers such as vinylon fibers, cotton chips and aramid fibers. On the other hand, examples of the spherical inorganic filler include light calcium carbonate, titanium oxide and the like. Also,
Examples of the molding method include injection molding, compression molding, transfer molding and the like.

As a feature of the present invention, in the surface of the resin pulley, the entire surface including each rib groove 2 has the skin layer 3 removed at the time of molding as shown by the phantom line in FIG. It is used as a layer removal surface. The surface roughness of the resin pulley is Rmax ≤ 20 µm. Removal of these skin layers 3 and adjustment of the surface roughness are performed by blasting, surface grinding, or the like.

Therefore, according to this embodiment, since the skin layer 3 on the surface of the pulley is removed, when the V-ribbed belt t is wound around and travels, the skin layer 3 is prevented from coming into contact with the belt t. be able to. Therefore, the friction coefficient between the belt t and the resin pulley is determined by the skin layer 3
Is smaller than that in the case where the belt t is in contact with the belt t, and it is possible to avoid the occurrence of belt vibration caused by the adhesion of the belt t to the resin pulley.

Furthermore, when removing the skin layer 3,
The unevenness of the parting line caused by the split mold can be made small at the same time, so that the belt vibration due to the unevenness of the parting line can be prevented in advance.

Further, the surface roughness of the resin pulley is Rmax.
Since ≦ 20 μm is suppressed, it is possible to suppress an increase in the amount of belt wear caused by the removal of the skin layer 3 and avoid shortening the belt life.

Since the organic fiber material and the spherical inorganic filler are mixed in the phenol resin, the life of the belt is shortened as compared with the case where the inorganic fiber material and the needle-shaped inorganic filler are mixed. Dimensional stability, rigidity, without
The resin pulley can be reinforced with respect to wear resistance and impact resistance.

In the above embodiment, both the organic fiber material and the spherical inorganic filler are mixed in the phenol resin material, but only one of them may be mixed.

Further, in the above-mentioned embodiment, the skin layer 3 on the entire surface of the resin pulley is removed, but the removal range of the skin layer is particularly limited as long as it includes at least the portion that contacts the belt. It is not something that will be done.

Further, in the above embodiment, the surface roughness of the resin pulley is suppressed to Rmax ≦ 20 μm.
The surface roughness does not need to be particularly limited in terms of reducing belt vibration.

Further, in the above embodiment, the resin pulley for the V-ribbed belt is described, but it is needless to say that the present invention can be applied to the resin pulley for other friction transmission belts.

[0028]

[Examples] Next, experiments performed to examine the coefficient of friction between the resin pulley and the V-ribbed belt, the amount of belt wear, the adhesion of rubber, the vibration of the belt, and the increase in the slip ratio due to water injection will be described. Here, two invention examples 1 and 2 in which cotton fibers were mixed as the organic fiber material and the pitch diameter φ was φ = 120 mm were prepared, respectively. The skin layer was removed by surface polishing. At that time, the surface roughness Rmax is Rmax =
Inventive Example 1 had a thickness of 15.3 μm.
On the other hand, Inventive Example 2 was one in which the surface roughness Rmax was set to Rmax = 23.0 μm.

Further, for comparison, three Comparative Examples 1 to 1 are used.
3 were produced respectively. That is, Comparative Example 1 is S45C.
A metal pulley made of a material whose surface roughness Rmax is Rmax
= 12.6 μm. Comparative Example 2 is a resin pulley made of a phenol resin material, and the skin layer was removed by surface polishing as in the case of Invention Examples 1 and 2, but glass fibers were mixed, and the surface roughness was Rmax is R
max = 13.5 μm. Comparative Example 3 is a resin pulley also made of a phenol resin material, in which cotton fibers are mixed as in the case of Invention Examples 1 and 2, but the skin layer is not removed and the surface thereof is not removed. Roughness Rma
x is Rmax = 5.0 μm. still. Comparative Examples 1 to 1
Each pitch diameter φ of 3 was also set to φ = 120 mm.

The apparatus shown in FIG. 2 was used to measure the friction coefficient. That is, one end of the V-ribbed belt t wound around the resin pulley p or the metal pulley p is fixed to the fixed body 12 via the load cell 11, while the other end is fixed at 17
The coefficient of friction between the belt t and the pulley p was measured by rotating the pulley p in the counterclockwise direction indicated by the arrow in the figure at a speed of 22 rpm with the weight 13 of 5 kgf attached. Also, at that time, the belt rubber pulley p
The adhesion of rubber depending on the presence or absence of adhesion to the belt and the magnitude of belt vibration were examined.

The apparatus shown in FIG. 3 was used to measure the belt wear amount. That is, with the pulley p as the drive side,
A driven pulley 2 having a pitch diameter φ of 120 mm
1 is arranged so as to face each other and a belt t is wound around both pulleys p and 21, and a dead weight DW (DW = 120 kgf) in the direction in which the axial distance increases on the driven pulley 21.
While applying a load of 5.2 PS, the pulley p is moved in the clockwise direction indicated by the arrow in the figure at a speed of 1800 rpm for 24
Belt wear amount when rotating over time [unit: g]
Was measured.

To measure the increase in slip ratio due to the water injection, the device shown in FIG. 3 was used in combination. However, the dead weight DW for the driven pulley 21 is DW = 50 kgf
, And the load is changed to 2PS, and the pulley p is set to 1
It was designed to be rotationally driven at a speed of 000 rpm. Then, 2 is attached to the portion of the belt t immediately before being wound around the pulley p.
The slip rate [unit:%] when water was poured at a rate of 00 ml / min was measured, and the slip rate [unit:%] when water was not added was subtracted from the slip rate at the time of water injection.

The above results are also shown in Table 1 below.
In the table, in the column of belt vibration, “◯” indicates that the belt vibration is small, and “X” indicates that the belt vibration is large.

[0034]

[Table 1]

It can be seen from Table 1 above that the coefficient of friction μ is reasonably low without the skin layer as compared with the case with the skin layer. That is, in Comparative Example 3, μ = 1.1
In contrast, in Comparative Example 2 and Invention Example 1, μ =
0.7, and μ = 0.6 in Invention Example 2. And
It can be seen that the lower the friction coefficient, the less the rubber sticks and the smaller the belt vibration.

Next, comparing Comparative Example 2 and Inventive Example 1, although the friction coefficient is the same and there is no skin layer, the belt wear amount is in Comparative Example 2 in Inventive Example 1.
It is 1/10 of the case. It is considered that the reason for this is that, in Comparative Example 2, the reinforcing fiber is glass fiber, whereas in Inventive Example 1, it is cotton fiber.

From the above, in Invention Examples 1 and 2,
It can be seen that removing the skin layer not only provides excellent quietness with less belt vibration, but shortens the life of the belt by using cotton fiber instead of glass fiber.

Further, comparing the invention examples 1 and 2 with each other, it can be seen that the belt wear amount increases when the surface roughness is large as in the invention example 2. Even so, since it is much smaller than that of Comparative Example 2, it is considered that there is no problem in practical use, but in order to reduce the amount of belt wear as compared with Comparative Example 1, the surface roughness is set to Rmax ≤ 20 μm. Is desirable.

Finally, the increase in slip ratio due to water injection will be considered. Generally, the slip ratio of the resin pulley is higher than that of the metal pulley, and the transmission capacity is slightly lowered by that amount, but it is considered that the degree thereof does not affect the transmission capacity. Rather, the increase in the slip ratio due to water injection is smaller in the resin pulley than in the metal pulley. That is, the increase in slip ratio due to water injection is increased by 0.3% in Comparative Example 1, whereas
In Invention Example 1, the increase was only 0.1%. Therefore, it is considered that the resin pulley from which the skin layer has been removed and the metal pulley are not so different in slip characteristics during water injection.

[0040]

As described above, according to the first aspect of the present invention, when a resin pulley is manufactured by molding a phenolic resin material, the skin layer of at least the belt contact portion of the resin pulley after the molding. By removing the, the friction coefficient between the belt and the resin pulley is appropriately lowered to make it difficult for the rubber of the belt to adhere, so it is possible to avoid the occurrence of belt vibration due to the adhesion of the rubber, Further, since it is possible to eliminate the unevenness of the parting line at the same time when removing the skin layer, it is possible to simultaneously avoid the occurrence of belt vibration due to the unevenness of the parting line,
Therefore, excellent quietness can be obtained.

Further, since the organic fiber material or the spherical inorganic filler is mixed in the phenol resin material, the belt life is shortened as in the case where the inorganic fiber material or the needle-shaped inorganic filler is mixed. Without this, the resin pulley can be reinforced with respect to dimensional stability, rigidity, wear resistance, impact resistance, and the like.

According to the second aspect of the invention, the surface roughness of the skin layer-removed surface of the resin pulley is Rmax ≦ 20 μm,
Since the increase in the amount of wear of the belt caused by the removal of the skin layer is suppressed, the amount of wear of the belt can be made smaller than in the case of a metal pulley or the like, and the shortening of the belt life can be avoided.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a part of a resin pulley according to an embodiment of the present invention.

FIG. 2 is a schematic view showing an apparatus used for measuring a coefficient of friction between a pulley and a belt.

FIG. 3 is a schematic diagram showing an apparatus used for each measurement of a belt wear amount and a slip ratio.

[Explanation of symbols]

 2 rib groove (belt contact part) 3 skin layer t V ribbed belt (belt)

Claims (2)

[Claims] 1. A resin pulley, which is formed by molding a phenol resin material with a mold and is used for transmitting a torque between the belt and the belt, the phenol resin material comprising: The phenolic resin is mixed with an organic fiber material or a spherical inorganic filler, and at least the surface of the belt contact portion that comes into contact with the belt is the skin layer-removed surface of the skin layer formed during the molding. A resin pulley characterized in that 2. The resin pulley according to claim 1, wherein the surface roughness of the skin layer removal surface is Rmax ≦ 20 μm.