JP3059940B2 - Pulley for toothed belt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulley for a toothed belt which can reduce noise during rotational driving.

[0002]

2. Description of the Related Art For example, Japanese Unexamined Patent Publication (Kokai) No. 2-190654 discloses that the tip of a tooth is 1/3 of the thickness of a groove defined by a pulley.
The toothed belt is formed to have a radius of curvature of about １ ／ so that the tooth tips can smoothly mesh without rubbing the side surfaces of the belt teeth to reduce noise when driving the belt. A pulley is disclosed.

In Japanese Utility Model Laid-Open Publication No. 62-87251, a notch is formed in a circumferential or radial direction of a pulley for a toothed belt, and the cutout is formed before the pulley for a toothed belt engages with the toothed belt. There is disclosed a structure in which air is released from a cut portion to prevent generation of fluid noise and plosive sound when compressed air leaks from a gap, thereby reducing noise.

Further, according to the soundproof structure of a cam sprocket disclosed in Japanese Utility Model Laid-Open Publication No. Sho 63-121857, a groove is provided on the tooth contact surface of the cam sprocket in the direction of the rotation axis of the cam sprocket, so that the timing of the tooth of the cam sprocket is adjusted. There is disclosed an apparatus in which the air is prevented from being suddenly pushed out from between the two immediately after the teeth of the belt mesh with each other, thereby suppressing the generation of noise.

[0005]

However, in the above-mentioned conventional pulley for a toothed belt, since the pulley itself has a portion in close contact with the toothed belt, the pulley for the toothed belt and the toothed belt are stuck together. There was a drawback that sticky noise was generated.

In order to prevent sticking of the toothed belt and the pulley as described above, in the prior art, the pulley or the toothed belt is subjected to a process of reducing the sticky sound.
For this reason, it has been pointed out that the manufacturing cost of the toothed belt and the pulley increases, the manufacturing time becomes longer, and the production efficiency decreases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has a toothed belt capable of preventing sticking of a toothed belt and a pulley to reduce sticking noise and improving production efficiency. It is an object to provide a belt pulley.

[0008]

According to the present invention, there is provided a pulley for a toothed belt which is formed of a sintered metal and engages with a toothed belt to transmit a rotational motion. Pulleys project at equal intervals on the outer periphery of the pulley body
A plurality of teeth formed, are formed between the teeth, the teeth of the toothed belt and a concave engaging portion of disengageably semicircle arc, the engaging portion, Flat with the axial direction of the pulley
A plurality of grooves formed in a row and along the engagement portion in a semi-arc shape
Parts and projections, characterized in Rukoto provided alternately.

According to the present invention, the semicircular concave shape of the pulley is provided.
The engagement portion teeth of the toothed belt is engaged. Pulley clerk
In the joint, a plurality of grooves and protrusions are formed alternately.
Therefore, the toothed portion of the toothed belt is only the protrusion of the engaging portion of the pulley.
The driving force is transmitted from the pulley to the toothed belt while
Is reached. At this time, the driving force transmission between the pulley and the toothed belt
The contact area at the contact area is small,
The noise (sticky sound) when these are disengaged is extremely low
Small. In addition, the engaging portion is engaged with the tooth portion of the toothed belt.
When compressed, the air between them is compressed through the groove
Is discharged to the outside without being compressed.
Noise is also prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a pulley for a toothed belt according to the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 denotes a pulley for a toothed belt according to the present embodiment. This pulley 10
Is formed in a substantially circular shape having a predetermined thickness. The pulley 10 is formed from a metal such as iron through a sintering process so that the strength and durability of the pulley 10 are increased. The center of the pulley 10 is formed thin through a step 12,
In the center thereof is a hole 1 through which a rotating shaft to be described later is inserted.
4 is defined. A plurality of teeth 16 are formed on the outer periphery of the pulley 10 along the periphery thereof.
The space between them is formed as an engaging portion 20 having a substantially arc-shaped cross section. A shoulder between the engaging portion 20 and the tooth portion 16 is formed in an arc shape having a predetermined radius (see FIG. 2). The engaging part 2
As shown in FIGS. 2 and 3, nine grooves 24 are formed in parallel with the axial direction of the pulley 10 by knurling or the like, as shown in FIGS.
It is formed at 15 °, 35 °, 55 °, 75 ° and 90 °. The point A is the center line B of the engaging portion 20.
And the tangent of the pulley 10. The surface between the respective grooves 24 is formed as a projection 26 having a curved surface,
The surface of the engagement portion 20 is provided with the nine grooves 24 and 8.
The two protrusions 26 form an uneven portion 28.

As shown in FIG. 4, the pulley 10 is used, for example, as a drive pulley 10a and driven pulleys 10b and 10c constituting a rotation transmission mechanism 30 for an engine or the like. Hole 14 of drive pulley 10a
A rotary shaft 32 is inserted through the shaft, and the rotary shaft 32 is rotated by a driving force of an engine or the like (not shown). In the rotation transmitting mechanism 30, a tension pulley 34 is provided between the drive pulley 10a and one driven pulley 10b by an arrow D,
It is provided so as to be displaceable in the E direction. The tension pulley 3
4 is always biased in the direction of arrow D by a spring member (not shown) to apply a desired tension to the drive pulley 10a.
And the driven pulleys 10b and 10c are preferable. The rotation transmitting mechanism 30 is provided with a water pump pulley 36 between the driven pulleys 10b and 10c, and a water pump (not shown) is connected to a rotation shaft 38 of the water pump pulley 36.

The rotation transmission mechanism 30 has a toothed belt 40, which is provided with the drive pulley 10a,
Tension pulley 34, one driven pulley 10b,
It is suspended in the order of the water pump pulley 36 and the other driven pulley 10c. The toothed belt 40 is held at a predetermined tension by the tension pulley 34. The toothed belt 40 is, as shown in FIG.
A plurality of engageable teeth 42 are formed on the engagement portion 20 of the pulley 10 (drive pulley 10a and driven pulleys 10b, 10c), and the teeth 42 abut against the tip of the protrusion 26 having a curved surface. Touch Therefore, the teeth 42
The contact area between the and the engaging portion 20 is small. The toothed belt pulley 10 according to the present embodiment is basically configured as described above. Next, the operation and the effect of the pulley 10 will be described.

When the engine (not shown) is energized and the rotating shaft 32 rotates, the drive pulley 10a rotates and the toothed belt 40 moves in the direction of arrow C as shown in FIG. Therefore, the driven pulleys 10 b and 10 c rotate with the movement of the toothed belt 40.

At this time, as shown in FIG.
A plurality of tooth portions 42 of the toothed belt 40
Are sequentially engaged. When the tooth portion 42 is engaged with the engagement portion 20,
As shown in FIG. 3, the surface of the tooth portion 42 has a small contact area because it comes into contact with the tip of the projection 26 having a curved surface. Therefore, the adhesion portion between the tooth portion 42 and the projection 26 is extremely small, and the adhesion sound generated when the surface of the tooth portion 42 comes into contact with the tip of the projection 26 on the curved surface is also extremely small.
In addition, when the tooth portion 42 of the toothed belt 40 separates from the engagement portion 20, an adhesive sound is also generated. However, since the contact area between the tooth portion 42 and the protrusion 26 having a curved surface is small, at this time, Is also extremely low.

Further, when the tooth portion 42 is engaged with the engaging portion 20, air is compressed in the engaging portion 20, and the engaging portion 20 is compressed.
When compressed air leaks from the gap between the teeth 42 and the teeth 42, noise may occur. However, when the teeth 42 are engaged with the engaging portions 20, the air is gradually discharged from the grooves 24, so that the air is There is also an effect that the noise is not compressed and the generation of noise based on the compressed air is prevented.

[0017]

According to the pulley for a toothed belt according to the present invention, the following effects and advantages can be obtained.

In the driving force transmitting portion between the pulley and the toothed belt
Definitive contact area small fry, the adhesive portion therebetween
Substantially less, therefore, the adhesive portion Noise is reduced when detaching. Further, when the teeth of the toothed belt are engaged with the engaging portions, the air in the engaging portions is discharged from the grooves and is not compressed by the teeth, so that generation of noise due to the compressed air is prevented, The noise of equipment using this pulley is further reduced. For this reason, it becomes possible to manufacture equipment such as an engine with low noise. Further, since it is not necessary to perform the process of reducing the sticking noise on the pulley and the toothed belt, the manufacturing cost of the device using the pulley can be reduced, the manufacturing time can be shortened, and the production efficiency is improved. .

[Brief description of the drawings]

FIG. 1 is a perspective view showing a toothed belt pulley according to an embodiment of the present invention.

FIG. 2 is a partially enlarged perspective view of the pulley for a toothed belt in FIG. 1;

FIG. 3 is a partially enlarged sectional view of the pulley for a toothed belt in FIG. 1;

FIG. 4 is a schematic side view of a rotation transmitting mechanism using the pulley for a toothed belt of FIG. 1;

FIG. 5 is a schematic side view showing a state in which the toothed belt is engaged with the pulley for a toothed belt in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Pulley for toothed belt 10a ... Drive pulley 10b, 10c ... Driven pulley 16 ... Tooth part 20 ... Engagement part 24 ... Groove part 26 ... Projection part 28 ... Uneven part 30 ... Rotation transmission mechanism 40 ... Toothed belt

Claims (1)

(57) [Claims] 1. A pulley for a toothed belt, which is made of sintered metal and engages with a toothed belt to transmit rotational motion, wherein the pulleys are formed at equal intervals on an outer peripheral portion of a pulley body.
A plurality of teeth which are formed between the teeth, the teeth of the toothed belt and a concave engaging portion of the engaging and disengaging freely semicircular
The engaging portion has a plurality of grooves and protrusions formed parallel to the axial direction of the pulley and along the semicircular engaging portion.
Toothed belt pulley part is characterized Rukoto provided alternately.