JP2003247605A - Element of belt for continuously variable transmission, molding method for element of belt for continuously variable transmission, and belt for continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve flatness of overlapping faces of an element of a belt for a continuously variable transmission. <P>SOLUTION: A molding process of the element 20 is provided with: a wall thickness reducing process in which a recessed part 30a having smaller plate thickness than the other part of a platelike raw material 30 is formed in a part of the platelike raw material 30; and a press process in which the vicinity of the center of the recessed part 30a is formed by pressing to mold a nose 21 and a hole 22 integrally. In the wall thickness reducing process, the recessed part 30a whose shape is circular when viewed from the direction of plate thickness is formed in a part where the nose 21 on one side face of the platelike raw material 30 is formed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an element of a belt for a continuously variable transmission, a method for forming an element of a belt for a continuously variable transmission, and a belt for a continuously variable transmission.

[0002]

2. Description of the Related Art A continuously variable transmission is a transmission that continuously changes a gear ratio using a belt and a pulley, and includes a primary pulley to which torque is input, a secondary pulley to output torque, The belt includes a belt wound between the primary pulley and the secondary pulley, and a hydraulic control device that controls the groove widths of the primary pulley and the secondary pulley. In this continuously variable transmission, the gear ratio can be increased by widening the groove width of the primary pulley and narrowing the groove width of the secondary pulley. On the contrary, the gear ratio can be reduced by narrowing the groove width of the primary pulley and widening the groove width of the secondary pulley.

A belt for a continuously variable transmission, which is one of the components of such a continuously variable transmission, has a large number of plate-shaped elements stacked in the plate thickness direction and arranged in an annular shape, and each has a strip-shaped flexibility. Two rings formed by laminating thin plates are bundled so that a large number of these elements are not separated from each other. This belt transmits torque between both pulleys in a state where the element is sandwiched between the primary pulley and the secondary pulley.

Each element has a nose and a hole for positioning the elements relative to each other. Specifically, at the belt width direction central portion of the element, a nose protruding to one side in the plate thickness direction is formed,
A recessed hole corresponding to the protruding shape of the nose is formed in a position facing the nose on the other side surface in the plate thickness direction. The nose of each element engages with a hole in another adjacent element so that the elements are positioned relative to each other. Therefore, the size of the hole must be larger than the size of the nose. Also, to prevent the nose from getting caught in the hole when it contacts the pulley and a relative angle with the adjacent element occurs,
The size of the hole must be somewhat larger than the size of the nose.

On the other hand, since the elements are superposed in the plate thickness direction, it is necessary to ensure the flatness and parallelism of the superposed surfaces. If this is not ensured, the behavior of the elements becomes unstable, and problems such as noise due to rubbing between the elements and deterioration of torque transmission efficiency due to changes in the contact angle of the elements with respect to both pulleys occur. As a method of forming the nose and the hole of such an element, integral molding by embossing (pressing) can be considered. Since the nose and the hole are formed on both side surfaces at the same position of the element, it is possible to adopt integral molding by embossing.

[0006]

However, when molding by embossing, as described above, the diameter of the hole must be larger than the diameter of the nose, and the internal volume of the hole must be larger than the volume of the nose. As a result of the difference between the internal volume of the hole and the volume of the nose, the meat escapes to a portion other than the nose, forming a bulging portion in which the periphery of the nose bulges. This deteriorates the flatness of the overlapping surface of the elements.

An object of the present invention is to provide an element of a belt for a continuously variable transmission having a nose and a hole in which the flatness of the overlapping surface of the element is improved, and the flatness of the overlapping surface of the element can be improved. It is an object of the present invention to provide a method for forming an element of a belt for a continuously variable transmission having a nose and a hole, and to provide a belt for a continuously variable transmission having an element in which the flatness of the overlapping surface of the element is improved.

[0008]

An element of a belt for a continuously variable transmission according to claim 1 is a plurality of elements that are stacked in the plate thickness direction to form an annular belt for a continuously variable transmission, It has a nose, a hole and a bulge.
The nose is formed so as to project to one side surface in the plate thickness direction. The hole is formed so as to be recessed on the other side surface in the plate thickness direction, and is engaged with the nose of the adjacent element. The bulging portion is formed around the nose and bulges with respect to one side surface in the plate thickness direction. The ratio L / t of the maximum value L of the bulge length of the bulge portion to one side surface of the element and the plate thickness t of the element is 0.005 or less.

In the element of this continuously variable transmission belt, since the bulging length L of the bulging portion formed around the nose is sufficiently small, the flatness of the overlapping surface when the elements are stacked is improved. is doing. The method for molding an element of a belt for a continuously variable transmission according to claim 2, is a method for molding a plurality of elements that are stacked in the plate thickness direction to form an annular belt for a continuously variable transmission, the step being a thinning step. And a pressing process. In the thinning step, a recess having a smaller plate thickness than other portions of the plate-shaped material is formed in a part of the plate-shaped material. In the pressing process, the center of the recess is pressed to form a nose projecting on one side in the plate thickness direction and a hole formed on the other side in the plate thickness direction to engage the nose of an adjacent element. And are integrally molded. The minimum value T of the plate thickness of the plate-shaped material in the part where the recess is formed is 0.9 times or more the plate thickness t ₂ of the other part of the plate-shaped material by the thinning step. The range is 0.95 times or less, and the area A of the recess viewed from the plate thickness direction is 4 times or more and 16 times or less with respect to the area a of the nose formed by the pressing process viewed from the plate thickness direction. Is formed.

In this method for forming a belt element for a continuously variable transmission, in the thinning step, a recess having the above dimensions is formed in a part of the plate material, and then the nose and the hole are integrally formed in the pressing step. Therefore, the bulging length of the bulging portion formed around the nose can be reduced.
Thereby, the flatness of the overlapping surface of the elements can be improved.

According to a third aspect of the present invention, there is provided a method for forming a belt element for a continuously variable transmission according to the second aspect, wherein the recess is formed in the thinning step by plastically deforming a part of the plate material. ing. In this method for forming the element of the belt for a continuously variable transmission, the recess is formed in the thinning step by plastic deformation, so that it is less expensive than the case of cutting.

A belt for a continuously variable transmission according to claim 4 is
A belt for a continuously variable transmission wound between a primary pulley and a secondary pulley, comprising: the plurality of elements according to claim 1; and a ring that contacts the plurality of elements and bundles the plurality of elements. There is. In this continuously variable transmission belt, since the flatness of the overlapping surface of the element is improved, the contact state between the element and the ring is improved, and the durability is improved.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION
Continuously variable transmission adopting a belt for continuously variable transmission having
The machine is shown in FIG. (1) Schematic structure of continuously variable transmission The continuously variable transmission shown in FIG. 1 is transmitted from an engine in a vehicle.
A device that transmits the torque that is reached to the axle,
The ratio can be changed steplessly. this
Continuously variable transmissions mainly consist of the engine, the clutch and the fluid.
Primary pulley driven via a rotary torque transmission device, etc.
1 and the secondary pulley 2 connected to the axle and both pulleys.
Belt 3 hung over pulleys 1 and 2 and pulleys 1 and 2 on both sides
Groove width W _p, W_sA hydraulic control device (not shown) for controlling
It consists of The belt 3 has each
Contact the conical surfaces 1a, 2a of the pulleys 1, 2 that face each other.
Therefore, the groove width W of the pulleys 1 and 2_p, W_sChange by hydraulic control
Then, the position of the pulleys 1 and 2 will change accordingly.
Turn into. And with this continuously variable transmission,
Groove width W of 1_pTo widen the groove width W of the secondary pulley 2._s
When is narrowed, the gear ratio is increased. On the contrary, the primer
Groove width W of re-pulley 1_pOf the secondary pulley 2
Groove width W_sWhen is wide, the gear ratio becomes small.

(2) Constitution of Belt As shown in FIG. 2, the belt 3 has a large number of plate-like elements 20 arranged in an annular shape by superimposing them in the plate thickness direction, and a plurality of strip-like flexible thin plates. A large number of elements 20 are bundled by two rings 11 formed by stacking so as not to be separated from each other. In this belt 3, the element 20 has a primary pulley 1 and a secondary pulley 2
The torque is transmitted between the pulleys 1 and 2 while being sandwiched between the conical surfaces 1a and 2a facing each other.

(3) Element Configuration FIGS. 3 and 4 are sectional views of the element 20. Here, FIG. 3 is a sectional view taken along line I-I of FIG. 2, and FIG.
It is an I-II sectional view. Each element 20 is formed with unevenness for positioning each other. Specifically, a nose 21 protruding in a cylindrical shape is formed on one side surface in the plate thickness direction at the center portion of the element 20 in the belt width direction, and a cylindrical shape is formed at a position facing the nose 21 on the other side surface in the plate thickness direction. A recessed hole 22 is formed.

The nose 21 of each element 20 engages with the hole 22 of another adjacent element 20, thereby positioning each element 20 relative to each other. Therefore, the diameter d _{2 of the} hole 22 is equal to the diameter d _{1 of the} nose 21.
Must be greater than. Further, the diameter d _{2 of the} hole 22 is larger than the diameter d _{1 of the} nose 21 so that the nose 21 is not caught in the hole 22 when the pulleys 1 and 2 come into contact with each other to form a relative angle with the adjacent element 20. Must be large to some extent.

In the present embodiment, the plate thickness t ₁ of the element 20 is 1.5 mm. The diameter d _{2 of the} hole 22 is
The diameter is set to be 0.2 mm larger than the diameter d _{1 of the} nose 21. Further, the depth h ₂ of the hole 22 in the plate thickness direction is set to be 0.1 mm larger than the protruding length h ₁ of the nose 21 in the plate thickness direction.

Around the nose 21, as shown in FIG. 4, a bulging portion 23 slightly bulging with respect to one side surface in the plate thickness direction.
Are formed. The bulging portion 23 is a portion formed during embossing (pressing) of the nose 21 and the hole 22 described later. In the present embodiment, the ratio L / t ₁ of the bulging length L of the bulging portion 23 to one side surface of the element 20 and the plate thickness t _{1 of the} element 20 is as small as 0.005 or less, It has high flatness. For this reason, as shown in FIG. 3, when the plurality of elements 20 are stacked, the contact state of the stacked surfaces 20a and 20b becomes good.

As shown in FIG. 3, the inner peripheral portion 24 of the element 20 is thinner than the outer peripheral portion where the nose 21 and the hole 22 are formed, and the element 20 contacts the pulleys 1 and 2. When the relative angle with the adjacent element 20 is generated, it is allowed. (4) Method of Forming Element As shown in FIG. 5, the element 20 is manufactured from a plate-shaped material 30. Specifically, the plate-shaped material 30 is molded into the element 20 through the following steps.

The forming process of the element 20 is performed by the plate-shaped material 3
A thinning step of forming a concave portion 30a having a smaller plate thickness than the other portion of the plate-shaped material 30 in a part of 0, and pressing the central portion of the concave portion 30a to integrally form the nose 21 and the hole 22. And a pressing process. In the thinning step, as shown in FIG. 5, a concave portion 30a having a circular shape when viewed in the plate thickness direction is formed in a portion where the nose 21 is formed on one side surface of the plate material 30. . The forming of the recess 30a is performed by cutting or plastic deformation, but in the present embodiment, the cost is emphasized and coining, which is a type of plastic deformation, is performed. At this time, the minimum value T of the plate thickness of the portion where the recess 30a is formed is 0.9 with respect to the plate thickness t ₂ of the plate-shaped material 30.
It is formed so as to be in the range of not less than twice and not more than 0.95 times. The diameter D of the recess 30a when viewed from the plate thickness direction is the diameter d _{1 of the} nose 21 that is finally formed (see FIG. 4).
2) or more and 4 times or less, that is, the area A when the recess 30a is viewed from the plate thickness direction is the area a when the nose 21 is viewed from the plate thickness direction. On the other hand, it is formed to have a range of 4 times or more and 16 times or less.

Next, the inner peripheral portion 24 of the element 20 (see FIG.
(See reference), a force is applied in the plate thickness direction to reduce the plate thickness of the inner peripheral portion 24. This process may be reversed in order from the next pressing process. In the pressing step, embossing is performed on the portion where the recess 30a is formed. In particular,
As shown in FIG. 6, the plate material 30 is attached to the die 4 of the nose 21.
It is sandwiched by 1 and the punch holder 42 in the plate thickness direction. Here, the die 41 has a cylindrical recess 41 a having the same inner surface shape as the outer diameter of the nose 21, and the punch holder 42 has a hole 42 a having an inner diameter larger than the inner diameter of the hole 22. Then, the recess 30 of the plate-shaped material 30
a is disposed at the center of the recess 41a of the die 41 and the hole 42a of the punch holder 42. The punch 43 is a columnar member having an outer diameter that is the same as the inner diameter of the hole 22, and uses the plate-shaped material 30 for the die 41 and the punch holder 42.
It is arranged so as not to project to the upper surface of the punch holder 42 when sandwiched by. Thereafter, as shown in FIG. 7, the punch 43 is pushed out above the punch holder 42 to form the plate-shaped material 30 into a cross-sectional shape having the nose 21 and the hole 22 as shown in FIG.

Finally, the outer shape of the element 20 is punched out so that the element 20 has the planar shape shown in FIG.
As described above, by press-molding the nose 21 and the hole 22 in the portion where the recessed portion 30a having the specified dimension is formed, the bulging length L of the bulging portion 23 around the nose 21 is formed.
Can be reduced (specifically, L / t ₁ can be 0.005 or less).

(5) Characteristics of Element Forming Method The characteristics of the element 20 forming method of the continuously variable transmission belt 3 of this embodiment will be described. In the method of forming the element 20 of the present embodiment, in the thinning step, the portion forming the nose 21 and the hole 22 is subjected to coining to form the recess 30a. As a result, in the extrusion step, even if the nose 21 and the hole 22 are formed, the bulging length L of the bulging portion 23 in the plate thickness direction can be made extremely small, and the flatness can be improved. Thereby, the overlapping surfaces 20a, 20 of the element 20
The contact state of b is improved, and the durability of the continuously variable transmission belt 3 is improved.

The element 2 having such improved flatness
The size of the concave portion 30a defined to obtain 0 is the ratio L / t ₁ of the bulging length L of the bulging portion 23 and the plate thickness t _{1 of the} element.
Has an important role as follows.
For example, in the thinning process, the minimum value T of the plate thickness of the portion recess 30a is formed in the plate thickness t ₂ of the plate material 30 0.
The diameter D when the recess 30a is 95 times or more or when the recess 30a is viewed from the plate thickness direction is the diameter d of the nose 21 that is finally formed.
_{When the number is 1} times or less than ₁ , the conventional element 120 in which the nose 21 and the hole 22 are formed without performing the thinning process
Similarly to (see FIG. 10), the bulging length L ₁ of the bulging portion 123
Will become bigger. For example, when the nose 21 and the hole 22 are formed without performing the thinning step, the bulging length L
The ratio L ₁ / t ₁ with thickness t ₁ of ₁ and element 120, 0.
01. That is, the bulging length L ₁ of the conventional element 120 is twice or more the bulging length L of the element 20 in the present embodiment.

On the contrary, in the thinning step, when the minimum value T of the plate thickness of the portion where the recess 30a is formed is set to 0.9 times or less of the plate thickness t ₂ of the plate material 30, or when the recess 30a has the plate thickness The diameter D when viewed from the direction is the nose 21 that is finally formed.
If the diameter d ₁ is 4 times or more, the element 220
As shown in FIG. 11, since the periphery of the nose 221 is recessed from the stacking surface of the element 220, when the element 220 is stacked, there is a portion where the stacking surface cannot contact the circumference of the nose 221.

As described above, the dimension of the recess 30a in the method of molding the element 20 of the continuously variable transmission belt according to this embodiment is set to a dimension suitable for improving the flatness of the overlapping surfaces 20a and 20b of the element 20. And plays an important role in improving the flatness of the overlapping surface of the element. (6) Other Embodiments The embodiments of the present invention have been described above, but the specific configurations are not limited to the above-mentioned embodiments, and can be modified without departing from the spirit of the invention.

For example, in the thinning step of the above-described embodiment, a concave portion 30a having a plate thickness T and a diameter D is formed on the surface of the plate-shaped material 30 on which the nose 21 is formed. As described above, the recess 30a having the plate thickness T and the diameter D may be formed on the surface opposite to the surface on which the nose 21 is formed. Also in this case, the element 20 shown in FIG. 4 is obtained.

Further, as shown in FIG. 9, the plate thickness T of the plate material 30 is the same as that in FIGS. 5 and 8 on both the surface on which the nose 21 is formed and the surface on the opposite side. Alternatively, two recesses 30a may be formed. Also in this case, the element 20 shown in FIG. 4 is obtained.

[0029]

The element of the belt for a continuously variable transmission according to the present invention has improved flatness of the overlapping surface of the element. Further, the method for forming the element of the belt for the continuously variable transmission according to the present invention can improve the flatness of the overlapping surface of the element.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a continuously variable transmission.

FIG. 2 is a sectional view of a belt for a continuously variable transmission according to an embodiment of the present invention.

3 is a sectional view taken along line I-I of FIG.

4 is a sectional view taken along line II-II of FIG.

FIG. 5 is a cross-sectional view in an element forming process (thinning process).

FIG. 6 is a diagram for explaining a forming process (pressing process) of the element.

FIG. 7 is a diagram illustrating an element forming process (pressing process).

FIG. 8 is a cross-sectional view in an element forming process (thinning process) according to another embodiment.

FIG. 9 is a cross-sectional view in an element forming process (thinning process) according to another embodiment.

FIG. 10 is a cross-sectional view of an element when the element is molded without a thinning step.

FIG. 11 is a cross-sectional view of the element when the recess of the recess is made too large in the thinning step.

[Explanation of symbols]

1 primary pulley 2 Secondary pulley 3 belts (belt for continuously variable transmission) 20 elements 21 nose 22 holes 23 bulge 30 plate material 30a recess

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kunitaka Tawara             Mitsubishi Motors, 5-3-8 Shiba, Minato-ku, Tokyo             Industry Co., Ltd. (72) Inventor Junji Kawai             Mitsubishi Motors, 5-3-8 Shiba, Minato-ku, Tokyo             Industry Co., Ltd. (72) Inventor Kazuhiko Kawaguchi             1-1-1 Kidamotomiya, Neyagawa-shi, Osaka             Within EXEDY Corporation (72) Inventor Yuji Mizukami             1-1-1 Kidamotomiya, Neyagawa-shi, Osaka             Within EXEDY Corporation F-term (reference) 4E087 CA17

Claims (4)

[Claims] 1. A plurality of elements constituting an annular continuously variable transmission belt which are superposed in the plate thickness direction, the nose being formed so as to project to one side face in the plate thickness direction, and the plate thickness direction and others. The hole is formed so as to be recessed in the side surface, the hole engaging with the nose of an adjacent element, and the bulging portion formed around the nose and bulging with respect to one side surface in the plate thickness direction, the bulging portion Ratio L / t of the maximum value L of the bulge length of the element to one side surface and the plate thickness t _{1 of the} element
₁ is an element of a belt for a continuously variable transmission, which is 0.005 or less. 2. A method for forming a plurality of elements that are stacked in the plate thickness direction to form an annular continuously variable transmission belt, wherein a part of the plate-shaped material is made more plate-shaped than the other part of the plate-shaped material. A thinning step of forming a recess having a small thickness, and a nose formed so as to project on one side surface in the plate thickness direction and a nose formed so as to be recessed on the other side surface in the plate thickness direction by press working near the center of the recess And a press step for integrally forming a hole that engages with the nose of the element, wherein the recess is the minimum value of the plate thickness of the plate-shaped material of the part where the recess is formed by the thinning step. T is in the range of 0.9 times or more and 0.95 times or less with respect to the plate thickness t ₂ of the other part of the plate-shaped material, and the area A of the recess viewed from the plate thickness direction.
Of the nose formed by the pressing step is formed to have a range of 4 times or more and 16 times or less with respect to the area a viewed from the plate thickness direction of the nose. Method. 3. The method for forming an element of a belt for a continuously variable transmission according to claim 2, wherein the forming of the recess in the thinning step is performed by plastically deforming a part of a plate-shaped material. . 4. A belt for a continuously variable transmission wound between a primary pulley and a secondary pulley, wherein the plurality of elements according to claim 1 and the plurality of elements in contact with the plurality of elements. A belt for a continuously variable transmission that includes a ring for bundling.