JP2002327802A - V-ribbed belt with cog - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a V-ribbed belt with cogs for restricting the noise level. SOLUTION: Each rib part 3 of the V-ribbed belt with cogs having several lines of V-shape rib in the longitudinal direction thereof is formed with a cog crest part 2 with the same pitch, and the cog crest pitch P between each lines of the rib is arranged with a phase difference S obtained by dividing the cog crest pitch P with the number K of lines.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a plurality of rows of V-shaped ribs in the longitudinal direction, and the ribs have transverse cog ridges formed all around at a predetermined pitch. More specifically, the present invention relates to a cogged V-ribbed belt, in which a peak value of a noise level generated when a belt and a pulley groove mesh with each other is reduced by regularly determining a plurality of rows of cog peak pitches and a phase difference of the cog peak pitch between rows. The present invention relates to a cogged V-ribbed belt.

[0002]

2. Description of the Related Art Conventionally, a V-ribbed belt has been required to have a large contact area with a pulley groove in order to improve transmission power performance. For this reason, the tip of the rib portion of the V-ribbed belt must have an acute angle and a large rib height.

[0003] However, for example, a V-ribbed belt used for driving an auxiliary machine of an internal combustion engine for an automobile is wound around a small-diameter pulley due to a need for compactness.
As a result, a large bending stress due to bending acts on the belt, and there is a problem that cracks are generated in the rib portions due to heat generation or stress concentration inside the belt due to the stress.

Therefore, as a means for correcting the bending stress, a rib height is reduced by making the tip of the rib portion flat (trapezoidal) from an acute angle, and a shape for suppressing internal heat generation and cracks due to bending stress. Has come to be used favorably.

In recent years, however, many auxiliary devices (air conditioners, power windows, power steerings, etc.) have been used for internal combustion engines for automobiles due to their convenience, and the required load power has increased. I went. For this reason, a V-ribbed belt that transmits power by friction transmission causes a slip on a pulley due to a shortage of a contact area used for friction transmission, thereby causing a sound generation problem.

Therefore, in the art, as a means for suppressing the bending stress and increasing the contact area, first, the tip of the rib is sharpened in order to increase the contact area.
Alternatively, a method of increasing the rib height has been adopted.

[0007] In order to correct the increased bending stress, a method of reducing the bending stress by arranging a notch portion at the tip of the rib portion, that is, a cog peak portion at a predetermined pitch all around the circumference has been used. Was.

The above technique, that is, a method of arranging a cog peak on a rib of a V-ribbed belt is a well-known technique.
It is disclosed in JP-A-502574.

[0009]

However, in this method, when the belt enters the pulley, a gap (aerial resonance cylinder) defined by the V-groove portion of the grooved pulley and the rib portion of the belt forms a cog peak. It is formed in accordance with the pitch, and the rubbing noise between the cog peak portion and the V groove side surface of the pulley due to the discontinuous cross section of the belt is periodically generated.

As a method of avoiding such annoying noise having a specific frequency spectrum depending on a specific pitch of the cog peak, for example, the above-mentioned Japanese Patent Application Laid-Open No. Hei 8-502574.
Japanese Patent Application Laid-Open Publication No. H11-15064 proposes a cogged V-ribbed belt in which the height of the cog peak portion is reduced and the cog peak pitch is set at random.

However, this method is a method of suppressing resonance of a specific frequency spectrum, and is an effective method for a cogged V-belt in which sound sources are arranged in a single file in the longitudinal direction. In a cogged V-ribbed belt having sound sources (produced by ribs and V-grooves in each row), it is not possible to suppress synthesized noise from a plurality of sound sources by randomizing the cog peak pitch. Can not.

The present inventor has invented a cogged V-ribbed belt having the following structure as a novel method for minimizing the combined noise of a cogged V-ribbed belt having a plurality of sound sources.

[0013]

According to a first aspect of the present invention, there is provided a cogged V-ribbed belt in which a plurality of rows of V-shaped rib strips arranged in the longitudinal direction of the belt are formed with cog peaks at a predetermined pitch. The cog peak pitch between rows and within each row is the same pitch, and the phase difference of the cog peak pitch between each row is
A cogged V-ribbed belt constituted by a phase difference obtained by dividing the cog peak pitch by the number of rows.

According to a second aspect of the present invention, a plurality of rows of V-shaped ribs are formed on both the inner and outer surfaces of the belt.
It is a ribbed belt.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view showing a meshed state of a cogged V-ribbed belt and a grooved pulley according to the present invention.

FIG. 2 is a schematic view showing a cogged V-ribbed belt according to the embodiment. FIG. 2 (a) is a plan view and FIG. 2 (b).
Is a front view, FIG. 2 (c) is a side view, and FIG. 3 is a sound pressure level (dB) of the cogged V-ribbed belt according to the embodiment of FIG.
6 is a graph showing the sum of the sums of FIG.

FIG. 4 is a schematic view showing a cogged V-ribbed belt according to a comparative example. FIG. 4 (a) is a plan view and FIG.
4B is a front view, FIG. 4C is a side view, and FIG. 5 is a sound pressure level (dB) of a cogged V-ribbed belt according to a comparative example.
6 is a graph showing the sum of the sums of FIG.

Here, the definition of noise is described as follows for convenience of explanation. As is well known, in the acoustic field, since the square of the sound pressure is proportional to the power, the magnitude of the noise is often represented by the sound pressure level (dB). This sound pressure level (dB) is expressed by a logarithmic expression as follows.

Sound pressure level (dB) = ₁₀ Log ₁₀ (P ²
/ P ₀ ² ) = 20 Log ₁₀ (P / P ₀ ), where P (Pa) is the effective value of the measured sound pressure.
₀ (Pa) is the effective value (20 μPa) of the reference sound pressure.

The magnitude of noise [sound pressure level (dB)]
Is generally represented by the A-weighted sound pressure level (dB) corrected by human perception, but for simplicity of description, the following description will be made using the sound pressure level (dB).

First, a cogged V-ribbed belt 1, 1 '
The outline of the configuration and the manufacturing method thereof will be described. As shown in FIGS. 2 and 4, the V-ribbed belts 1 and 1 ′ with cogs are formed by laminating compressed rubber layers 6 and 6 ′ and adhesive rubber layers 7 and 7 ′ from the inner peripheral side. , 4 '
Is spirally wound, and the adhesive rubber layers 7, 7 'are further formed thereon.
And the fabric layers 5, 5 'are laminated. The cord ropes 4, 4' are made of a low-stretch, high-strength material such as polyester, polyamide, glass fiber, etc. For the rubber layer, a material composed of natural rubber, styrene-butadiene rubber, chloroprene rubber, hydrogenated nitrile rubber, ethylene propylene rubber, alkylated chlorosulfonated polyethylene, or the like is used alone or in combination.

The belt is manufactured by using a flat press die. In this method, a compressed rubber layer (rib strips 3, 3 ') 6,
The unvulcanized rubber sheet to be 6 ′ and the unvulcanized rubber sheet to be the adhesive rubber layers 7 and 7 ′ are stacked and mounted, and the core ropes 4 and 4 ′ are mounted thereon under a predetermined tension, Further, the unvulcanized rubber sheet which becomes the adhesive rubber layers 7 and 7 'is placed thereon, and the unvulcanized canvas with rubber which becomes the canvas layers 5 and 5' is further placed. After the contact, predetermined vulcanization conditions (0.
(5 to 1.5 MPa, 150 to 180 ° C, 10 to 30 minutes)
Vulcanization in a progressive manner until a predetermined belt circumference is reached.

The method of engraving a predetermined pattern (the shape of the rib portion and the shape of the cog mountain portion) on the lower mold is as follows.
At present, it is performed by machining using an NC machine tool according to an automatic program.

Next, the sound generation mechanism characteristic of the cogged V-ribbed belts 1 and 1 'will be described with reference to FIG. FIG.
As an example, the cogged V-ribbed belts 1 and 1 ′ having the rib strips 3 and 3 ′ having the number of ribs 4 are changed to the V-groove section 11 having the number of the grooves 4 as well.
The figure shows a state in which required power is transmitted by being wound around a grooved pulley 10 having a groove.

In FIG. 1, a cogged V-ribbed belt 1,
1 'forms notches 8, 8' at a predetermined pitch in each row of a plurality of ribs 3, 3 'arranged in parallel in the longitudinal direction of the belt, and a plurality of ribs 3, 3 3 ',
This is a belt in which cog ridges 2, 2 'having a predetermined pitch are formed in the width direction.

When the cog ridges 2 and 2 'of the cog V-ribbed belts 1 and 1' enter the groove 11 of the grooved pulley 10, the cog ridges 2 and 2 near the point M in FIG. 'Is V
It rubs violently against the side surface of the groove 11. At this time, a closed space is formed between the cog peaks 2 and 2 ′ adjacent to the front and the cog peaks 2 and 2 ′ that rub against each other, and this space serves as a resonance body to amplify the rubbing sound.

The rubbing sound is generated periodically in accordance with the pitch of the cog peaks 2 and 2 '. The sound generation mechanism unique to the present invention is a plurality of V-grooves 11 arranged in parallel from the vicinity of the point M of the V-grooves 11. The pronunciation may be a plurality of independent sound sources.

That is, while the conventional cogged V-belt or toothed belt has a single row of ribs, the cogged V-ribbed belts 1 and 1 'of the present invention have a plurality of ribs. This leads to a marked difference in the handling of sound sources.

More specifically, since there is only one sounding point from the cogged V-belt or the toothed belt in which the cog ridges are arranged at a predetermined pitch on one row of ribs, there is only one sounding point. Although the sound pressure level (dB) may be superimposed (autocorrelation) in time series, the V-ribbed belt 1 with cogs,
Sound pressure levels (d
B) is not synthesized.

Hereinafter, a method of arranging a cog peak pitch which minimizes a sound pressure level (dB) synthesized from a plurality of sound sources, which is a feature of the present invention, and an effect thereof will be described in detail with reference to FIGS. Will be described. 4A and 4B show the arrangement of the cog peak pitch P according to the comparative example. FIG. 4A is a plan view, FIG. 4B is a front view, and FIG. 4C is a BB arrow in FIG. FIG.

In FIG. 4 (a), the cogged V-ribbed belt 1 'has three ribs, and as shown in FIG.
No phase difference S is provided in the cog peak pitch P. That is, there are three sound sources, and the sounding times due to the abrasion are the same.

The synthesis of sound pressure levels (dB) emitted from the plurality of sound sources is as shown in FIG. FIG.
The sound pressure signal shown in (a) is a signal in which the phase difference S of the rib portion 3 ′ in the second row in FIG. 4A is の of the cog peak pitch P.

When the sound pressure level (dB) is evaluated, the sound pressure level (dB) ∝ (sound pressure) × (sound pressure). Has the same result as the arrangement of FIG. 4A where the phase difference S is not provided. (The same result is obtained when the sum of the squares of sound pressure is obtained.) That is, as shown in FIG. 5B, when sound pressure levels (dB) from three sound sources are combined, the maximum peak value becomes
y ′ = 3.

On the other hand, in the arrangement of the cog ridges 2 according to the embodiment, as shown in FIG. 2, in the cog V-ribbed belt 1 having three ribs, the phase difference S of the cog ridge pitch P between the rows is made equal. The phase difference S is the cog peak pitch P
Is divided by the number of ribs K.

Based on this arrangement, the sound pressures emitted simultaneously from three locations are as shown in FIG. When the sound pressure level (dB) is synthesized based on this sound pressure, the result is shown in FIG.
As shown in (b), the maximum peak value is y ′ = 1.5.

Accordingly, in the case of a cogged V-ribbed belt in which cog peaks are arranged at a predetermined pitch on a plurality of ribs,
Rather than randomly arranging the cog peak pitches P as in the prior art, it is optimal to set the phase difference S to a regular equal pitch and to set the cog peak pitches P of the rib portions to the same pitch in each row. You can see that.

In the above description, the cogged V-ribbed belt 1 having three ribs has been described as an example, but this relationship does not change even when the number of ribs becomes four or more. That is, when the phase difference S is equal pitch (cog peak pitch P is divided by the number of ribs K = 4) with four ribs, the maximum peak value is y ′ = 2.0, and no phase difference is provided. The largest peak value in case
y ′ = 4.0.

In the case of four ribs, when the phase difference S is randomized, the maximum peak value y 'is 2.
It will fall between 0 and 4.0, but its minimum value is 2.0 as shown.

Hereinafter, embodiments will be described in detail. The compressed rubber layers (rib strips 3 and 3 ') of the cogged V-ribbed belts 1 and 1' of the examples and the comparative examples have carbon black (HAF) 4 based on 100 parts by weight of chloroprene rubber.
0, Cotton cut thread 10, Nylon cut thread 10, DOP
8, a rubber material containing stearic acid 2, MgO4, ZnO5, an antioxidant 4, a vulcanization accelerator 2, and sulfur 1 was used.

Other belt shapes (rib shape, cog shape), evaluation test items and test results are as shown in Table 1 below.

[0041]

[Table 1] From the results in Table 1, the transmission torque of Example 1 was 17 Nm / 3.
In contrast to the ribs, the transmission torque of Comparative Example 2 was 12 Nm
Because of the ３ rib, Example 1 according to the present invention is superior to Comparative Example 2 in transmission performance. Thus, the effect of increasing the contact area with the pulley groove 11 was confirmed.

In the first embodiment, the cog peak 2
By providing the (notch portion 8), the bending stress is reduced, and thus the heat-resistant running life is 420 hours. The result was improved.

From the measurement result of the sound pressure level A (dB), the phase difference S (= 1.
3 mm), the sound pressure level A (dB) of the first embodiment is 73
(DB). On the other hand, the sound pressure level A (dB) of Comparative Example 3 in which the phase difference S (= 0) is not provided is 80 (dB). By providing a regular phase difference S, the sound pressure level (d
The effect of reducing B) was confirmed.

The evaluation of the sound pressure level (dB) was performed with a diameter of 4
A V-ribbed belt with cogs as shown in Table 1 was attached to a running test machine having a 5-mm grooved pulley mounted on two axes, and the rotation speed was 3,600 rpm.
pm, and measured by a sound level meter (A scale) installed at a predetermined position (center of the span).

[0045]

According to the first aspect of the present invention, since the phase difference of the cog peak pitch between the respective rows can be accurately set, the combined sound pressure level (dB) of the sound pressure levels (dB) emitted from a plurality of sound sources can be set. dB) can be accurately smoothed and its maximum peak value minimized. As a result, a remarkable effect of suppressing the peak value of the synthesized sound pressure level (noise) is recognized.

According to the second aspect of the present invention, it is possible to minimize the maximum peak value of the combined sound pressure level (dB) of the sound pressure levels (dB) emitted from a plurality of sound sources even in the belt double-side drive.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an engaged state of a cogged V-ribbed belt and a pulley according to the present invention.

FIG. 2 is a schematic view showing a cogged V-ribbed belt according to an embodiment, FIG. 1 (a) is a plan view, FIG. 1 (b) is a front view,
FIG. 1C is a side view.

FIG. 3 is a graph showing a combined sum of sound pressure levels (dB) of a cogged V-ribbed belt according to an example.

4 is a schematic view showing a cogged V-ribbed belt according to a comparative example, FIG. 4 (a) is a plan view, FIG. 4 (b) is a front view, and FIG.
4 (c) is a side view.

FIG. 5 is a graph showing a combined sum of sound pressure levels (dB) of a cogged V-ribbed belt according to a comparative example.

[Explanation of symbols]

 1, 1 'belt 2, 2' cog peak 3, 3 'rib strip 4, 4' core rope 5, 5 'canvas layer 6, 6' compressed rubber layer 7, 7 'adhesive rubber layer 8, 8' Notch part 10 Pulley with groove 11 V groove part P Cog peak pitch S Phase difference K Number of ribs

Claims (2)

[Claims] 1. A cogged V-shape in which cog peaks are formed at a predetermined pitch on a plurality of rows of V-shaped ribs arranged in the longitudinal direction of the belt.
In the ribbed belt, the cog peak pitch between each row and within each row is the same pitch, and the phase difference of the cog peak pitch between the rows is a phase difference obtained by dividing the cog peak pitch of the cog peak portion by the number of rows. A cogged V-ribbed belt characterized by the following. 2. The V-ribbed belt with cogs according to claim 1, wherein a plurality of rows of V-shaped ribs are formed on both inner and outer surfaces of the belt.