JP3126684B2 - Pulley half for V belt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved driven pulley half which is a component unit of a driven pulley for a V-belt used in a continuously variable transmission such as a scooter.

[0002]

2. Description of the Related Art Conventionally, as a continuously variable transmission such as a scooter, a V-belt is wound between a drive pulley on the engine output shaft side and a driven pulley on the output downstream side, and the V-belt for each pulley is driven at low speed and high speed. There is known a technique for changing the biting amount of the V-belt to change the winding position and posture of the V-belt. Such a pulley is composed of a pair of left and right pulley halves that sandwich the V-belt from the left and right, and changes the biting amount of the V-belt while changing the interval between the pulley halves.

By the way, the pulley half 5 of the driven pulley
As shown in FIG. 6, 1 includes a driven face 52 as a pulley disk and a boss 53 as a cylindrical shaft part. In joining these, a fitting hole provided in the center of the driven face 52 is provided. Of the driven face 52 and the boss 53, the joint a of the driven face 52 on the side opposite to the transmission face 52a side is plasma-welded, and the connection b of the driven face 52a side is joined. To be low-bonded.

[0004]

However, in the case of such a combination of the plasma welding and the low joining, the joining operation takes a long time and the heating time during the welding is long, so that the influence of the thermal strain is large, and the welding operation is difficult. There is a problem that a work series cannot be simplified because a distortion removing step is required as a subsequent step.

[0005] Also, the same as the conventional pulley half 51 or
It is also required to have more durability
You.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a pulley half which has a high durability against a load while simplifying a welding operation to prevent a problem such as thermal distortion .

[0007]

In order to solve the above-mentioned problems, the present invention is directed to a pulley disk according to claim 1, wherein one side of the pulley disk is formed as a transmission surface portion that comes into contact with the V-belt so as to open outward. A pulley half for a V-belt comprising a cylindrical shaft portion inserted into a central fitting hole of the pulley disc and joined and integrated, and the pulley disc has an uneven portion connected to a joining surface. The uneven portion is formed on the inner side in the radial direction and the boss is formed.
A first bulging portion bulging toward the belt contact surface along the axial direction of the boss, and a bulge formed radially outside of the first bulging portion and connected to the bull along the axial direction of the boss. Composed of a second swelling portion swelling in the opposite direction, and a cross-sectional shape of the uneven portion.
Has an S-shape and an inverted S-shape.

By forming the first and second bulging portions of the concave and convex portions along the entire area of the pulley disk along a concentric circle, if the concave and convex portions are made to be a rigid portion, the load applied to the transmission surface can be reduced. In this way, stress concentration on the joint surface can be avoided, and durability can be improved.

According to a second aspect of the present invention, the joining surface between the pulley disc and the cylindrical shaft portion is joined and integrated by laser welding. And this laser welding is a welding method that can be combined with the technology to disperse the stress in the uneven part of the pulley disk, and the welding time can be reduced by laser welding the joint surface, Since reduction is achieved and a strong beam is locally irradiated, adverse effects such as thermal distortion can be avoided.

[0010]

Embodiments of the present invention will be described with reference to the accompanying drawings. Here, FIG. 1 is a cross-sectional view of the continuously variable transmission mechanism of the scooter in a plan view, FIG. 2 is a partial perspective view of a part of a driven pulley half, and FIG. illustration, Figure 4 is
It is explanatory drawing of the bead width in laser welding .

As shown in FIG. 1, a continuously variable transmission mechanism of a scooter includes a drive pulley 1 attached to a tip end of a crankshaft S of an engine and divided into left and right parts, and a drive pulley 1 attached to a clutch shaft C and divided into left and right parts. A driven pulley 2 and a V-belt 3 wound between the pulleys 1 and 2;
2b is detachable from each of the halves 1a and 2a. By changing the intervals between the respective pulley halves 1a and 1b and between the pulley halves 2a and 2b, the position of the V-belt 3 sandwiched between the pulley halves is changed to change the speed.

The driven pulley half 2a on one side of the driven pulley 2 has a fitting hole 4a as shown in FIG.
And a driven face 4 as a pulley board having a transmission surface portion 4b and a boss 5 as a cylindrical shaft portion. The transmission surface portion 4b side is a contact surface with the V-belt 3. The pulley half for a V-belt of the present invention is a driven pulley half 2
This mainly relates to the shape of the driven face 4 and the welding structure of the joint face f between the driven face 4 and the boss 5.

That is, the driven face 4 has an uneven portion g connected to the joint surface f.
Is a first bulging portion g1 formed radially inward of the joining surface f and bulging toward the transmission surface 4b along the axial direction.
And a second bulging portion g2 formed radially outward from the first bulging portion g1 and bulging in the axial direction on the back side of the transmission surface 4b. The shape is such that an inverted S character is drawn following the U character.

By forming the driven face 4 in such a shape, the uneven portion g becomes a rigid portion. For example, as shown in FIG. 3, when a load is applied to the point P of the transmission surface 4b through the V belt 3, stress is generated. The portion Y is dispersed over a wide range of the uneven portion g, and local stress concentration can be avoided.

The joining of the joining surface f is performed by laser welding. The laser beam irradiation direction of this laser welding is a direction substantially along the axial direction from the back side of the transmission surface 4b, and a wedge-shaped weld bead is formed on the joint surface f by such laser welding.

From the experimental results described below, it has been found that argon gas is more effective as a welding gas in laser welding than helium gas. That is,
From the conclusion, as described above, the welding bead using helium gas has a wedge-like shape in which the bead width k2 is narrower than the welding depth k1, as shown in FIG. When gas was used, as shown in FIG. 4 (B), the welding depth k1 and the bead width k2 became a wedge-like shape close to an equilateral triangle, and it was found that the effect of quenching the stress generating portion was enhanced. .

Next, experimental results of a combination of the uneven portion g of the driven face 4 of the present invention and laser welding and other experimental examples will be described with reference to FIG. Here, FIG. 5 shows the driven pulley half 2a of the present invention and other test products.

First, FIG. 5A shows the same form as the present invention.
Forming irregularities g on the driven face 4 as welding gas
Laser welded using helium gas. Ma
(B) shows a laser in which the end face of the fitting hole 4a is abutted.
-Covered with two welded joints, (C)
Is plasma welded at one end of the joint surface f and brazed at the other end
It is a conventional product that has been damaged.

As shown in the representative example (C) , a driven pulley is applied to such a test sample or the like while applying a load W similar to that applied from a belt to a predetermined range on the tip side of the driven face 4. The half body 2a is rotated once every 360 degrees, and the stress is measured at the following points to check the durability.
Was. The location where the load W is applied is a location corresponding to the contact portion with the V-belt 3 when the gear of the scooter is selected as the low gear.

In this case, FIG.
Of the same form as the product of the present invention in which the irregularities g are formed
Laser welding, using helium gas as welding gas
For example, in this case, local stress concentration is avoided,
Durability close to conventional products was obtained.

In addition, in the case of FIG.
Durability is greatly improved by adopting a two-piece structure.
It was found that it could be increased, but cost and weight increased and adopted
Has difficulties.

Further , the present inventors have further improved the durability.
Repeated experiments to make the welding gas
And using argon gas instead of helium gas,
It has been found that durability can be improved about twice.

That is, when helium gas is used,
When the weld was examined, as shown in FIG.
In the case of helium gas, the shape of the weld bead is
In contrast to the narrow wedge shape with width k2,
In the case of gongas, the bead width k2 is wide and close to an equilateral triangle.
It turned out to be a wedge-shaped. And this blending
The fact that the bead width k2 expands as the
As described above.
You.

Incidentally, the laser welding conditions as described above
Are used when helium or argon is used as the gas.
The force was 3 KW and the speed was 2 m / min.

Then, the bonding surface f is laser-welded in this manner.
By contacting, without affecting the thermal effect over a wide area,
In addition, it was possible to simplify the work series and reduce costs.
come.

In the above embodiment, it has been described that the use of argon gas is more effective in terms of durability than the use of helium gas. It does not deny laser welding with gas. Also, the above embodiment is an example,
Any element having substantially the same configuration as the technical idea described in the claims of the present invention and having the same function and effect is included in the technical scope of the present invention. Needless to say.

[0027]

As described above, according to the present invention, the first and second bulging portions connected to the joining surface are formed on the pulley disk as described in claim 1, and therefore, the pulley disk is formed on the pulley disk. Stress concentration can be avoided, and durability can be improved. Further, if the joining surface between the pulley disk and the cylindrical shaft portion is joined and integrated by laser welding as in claim 2, the welding time can be reduced, and the man-hour can be reduced.
In addition, since a strong beam is locally irradiated, adverse effects such as thermal distortion can be avoided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a continuously variable transmission mechanism of a scooter in plan view.

FIG. 2 is a partial perspective view of a part of a driven pulley half.

FIG. 3 is an explanatory diagram for explaining a state of stress distribution with respect to a load.

FIG. 4 is an explanatory view of a bead width of laser welding, wherein (A)
Explanatory diagram when helium gas is used as welding gas,
(B) is the explanation when argon gas is used as the welding gas.
Figure

FIG. 5 is a view showing an example of various configurations of a driven pulley half used in a test.

FIG. 6 is a partial perspective view of a conventional driven pulley half.

[Explanation of symbols]

2a: half driven pulley, 4 ... driven face, 4
a: fitting hole, 4b: transmission surface portion, 5: boss, f: joining surface,
g: uneven portion, g1: first bulging portion, g2: second bulging portion.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16H 9/12 F16H 55/56

Claims (2)

(57) [Claims] 1. A pulley disk which is inclined so as to open outward as a transmission surface portion on one side of which contacts a V-belt. A pulley half for a V-belt comprising a cylindrical shaft portion inserted into a central fitting hole of the pulley disc and joined and integrated, and the pulley disc has an uneven portion connected to a joining surface. The uneven portion is formed on the inner side in the radial direction and swells toward the belt contact surface along the axial direction of the boss, and the outer side in the radial direction is continuous with the first swelling portion. A second bulging portion is formed and bulges in the opposite direction of the bull and the contact surface along the axial direction of the boss, and has a cross-sectional shape of S-shaped and inverted S-shaped.
A pulley half for a V-belt, having a curved shape . 2. The pulley for a V-belt according to claim 1, wherein a joining surface between the pulley disc and the cylindrical shaft portion is joined and integrated by laser welding. Half body.