JP3701536B2 - Punching method for continuously variable transmission belt elements - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a punching method for an element of a continuously variable transmission belt.
[0002]
[Prior art]
Generally, an element of a continuously variable transmission (CVT) belt includes a body having V surfaces on both sides contacting a pulley of a continuously variable transmission, and a head connected to the body through a pair of recesses. Yes. An endless ring is attached to each of the pair of recesses, whereby a plurality of elements are bundled in an annularly stacked state. And when this element is laminated | stacked cyclically | annularly and the belt for continuously variable transmission is formed, the said body will be located in an inner peripheral side, and a head part will be located in the outer peripheral side.
[0003]
And this kind of element is stamped and formed from a metal plate material using a die and a punch. Conventionally, as a punching method for this type of element, one disclosed in JP-A-11-309522 is known. In this method, a punching process for performing a punching process while leaving a connection portion with a plate material in a part of the element, and a separation process for completely punching the element by cutting the connection portion so as to separate the element from the plate material are provided. ing. The punching shape in the punching process corresponds to a portion of the element that requires the highest accuracy. That is, specifically, the element needs to form the shape of both concave portions with high precision so that the element can smoothly rotate with the endless ring engaged with the pair of concave portions. Further, it is necessary to form the V surfaces on both sides of the body with high accuracy so that the driving force of the pulley of the continuously variable transmission can be reliably transmitted. For this reason, in a punching process, a pair of recessed part which requires an accuracy, and the V surface of the both sides of a body are reliably sheared, and the precision is fully maintained.
[0004]
On the other hand, in this method, in the punching process, the connecting portion is formed at two locations, that is, the central portion (tip portion) of the head and the central portion of the body, which do not require much accuracy during shearing.
[0005]
However, when the connecting portion is punched and cut in the separation step, so-called sagging occurs in two portions, that is, the central portion of the head and the central portion of the body, which are inclined in the punching direction. If such a sag is formed on the tip side of the head that is positioned on the outer circumference side when it is laminated in an annular shape, the laminating direction will bend toward the head side due to contact between the sag when laminating elements. It tends to go in the direction opposite to the direction, and there is a disadvantage that adversely affects the stacking accuracy of the elements.
[0006]
[Problems to be solved by the invention]
The present invention eliminates such inconvenience, and the present invention can manufacture an element with sufficient accuracy, and further improve the stacking accuracy of the elements, and the element punching method for a continuously variable transmission belt. The purpose is to provide.
[0007]
[Means for Solving the Problems]
In order to achieve such an object, the present invention provides a body having V surfaces on both sides which are located on the inner peripheral side and are in contact with pulleys of a continuously variable transmission when a plurality of layers are annularly stacked, and a pair of annularly bound In a punching method of an element of a continuously variable transmission belt comprising a head that is connected to the body via a pair of recesses to which an endless ring is attached and is positioned on the outer peripheral side when a plurality of annularly stacked layers are provided, A punching process in which the element is formed by punching a part of a metal plate in a connected state via a connecting part, and the connecting part formed by the punching process is punched and cut along a boundary with the element. and a separation step of separating the element from, in the punching step, the connecting portion is formed at a position between the two V-faces of the body, the less the elements punching direction Punching the posture shifted thickness dimension of the position of the plate, the connection portion at the time of punching is completed, in order to ensure the thickness of the plate to the element, that connected to the element inclined without thickness changes Features.
[0008]
According to the present invention, the element in a state of being connected to the plate material via the connecting portion is punched by the punching step. At this time, the connecting portion is formed at a position between both V surfaces of the body of the element. As a result, the portions other than the connecting portion, that is, the pair of recesses between the head of the element and the body, and both V surfaces of the body are reliably sheared, and the accuracy can be sufficiently maintained.
[0009]
Next, in the separation step, the connecting portion is punched and cut to separate the element from the plate material. Since the connecting portion is formed at a position between both V surfaces of the body, it is only necessary to perform punching and cutting at this position. At this time, since the periphery of the head of the element has already been sheared with high precision by the punching process, the sagging when the connecting portion is punched and cut into a part of the head as in the case where the connecting portion is provided in the conventional head. Is not generated, and the flatness of the head can be ensured. As a result, when a plurality of elements are stacked, the heads can be reliably adhered to each other, and the stacking direction can be improved without bending the stacking direction toward the head and moving in the direction opposite to the circumferential direction. . In the separation step, even if a sag caused by the punching and cutting of the connecting portion occurs on the body side of the element, the body is positioned on the inner peripheral side when a plurality of elements are stacked in an annular shape. The film can be satisfactorily laminated along the circumferential direction.
[0011]
Then, the connecting portion is inclined without changing its plate thickness, and the thickness of the plate material is secured to the element when the punching is completed. Therefore, the element can have a sufficient thickness and high rigidity can be obtained. Thereby, even when the connecting portion is punched and cut in the separation step, it is possible to prevent the occurrence of defects such as element deformation.
[0012]
Moreover, in the said punching process of this invention, the said connection part is formed in the width dimension 1-3 times with respect to the thickness dimension of the said board | plate material, It is characterized by the above-mentioned.
[0013]
The element formed by the punching step is connected and held to the plate material by the connecting portion. However, if the width dimension of the connecting portion is smaller than the thickness dimension of the plate material, the connecting portion bends or cracks due to the weight of the element, and in some cases, during conveyance of the plate material when moving to the separation step, etc. There is a risk that the element will fall off the plate. In such a case, high-accuracy separation cannot be performed by punching and cutting the connecting portion. Further, if the width dimension of the connecting portion is larger than three times the thickness dimension of the plate material, the cutting resistance at the time of punching and cutting in the separation step becomes large and not only can be separated smoothly, but in some cases at the time of punching The cutting force may be applied to the element and the element may be deformed.
[0014]
Therefore, in the present invention, the width of the connecting portion is set to 1 to 3 times the thickness of the plate material to form a connecting portion that achieves both sufficient holding strength and easy cutting. Thereby, the connection state of a board | plate material and an element can be maintained firmly, and a highly accurate element can be formed by the smooth punching cutting in the said separation process.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. 1 is an explanatory plan view showing a punching shape of a plate material in the punching process of the present embodiment, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is an explanatory view schematically showing the punching process of the present embodiment. FIG. 4 is an explanatory view schematically showing the separation step of this embodiment, and FIG. 5 is an explanatory view showing the shape of the element.
[0016]
The punching method according to the present embodiment is employed when manufacturing the element 1 (see FIG. 5) constituting a continuously variable transmission belt (not shown). A plurality of the elements 1 are laminated in a ring shape and are integrally bound by a metal endless ring 2 to form a continuously variable transmission belt as shown in FIG. Although the endless ring 2 is not shown in detail, the endless ring 2 is formed by laminating a plurality of ring members formed in a plate shape.
[0017]
In this embodiment, as shown in FIG.1 and FIG.2, after performing the punching process which punches the element 1 from the metal board | plate material 3 via the connection part 4, the connection part 4 shown by the virtual line a in the figure. And a separation process described later for separating the element 1 from the plate 3 by punching and cutting along the boundary between the element 1 and the element 1. The shape of the element 1 formed at this time will be briefly described with reference to FIG. 5. The element 1 is a substantially triangular head located on the outer peripheral side when the continuously variable transmission belt is formed. 5 and a body 6 located on the inner peripheral side. The head 5 and the body 6 are integrally connected via a neck 7. The pair of recesses 8 formed by the neck 7 between the head 5 and the body 6 is fitted with the endless ring 2 described above when the continuously variable transmission belt is formed. Further, at both ends of the body 6, a pair of V planes 10 are provided in contact with the pulley 9 of the continuously variable transmission indicated by phantom lines in FIG. 5.
[0018]
Next, the punching process will be described. The punching process is performed by the first processing apparatus 11 shown in FIGS. 3 (a) and 3 (b). The first processing apparatus 11 includes a die 12 on which the plate material 3 is placed, and an element forming punch 13 for punching the plate material 3 on the die 12 into an element shape. A counter punch 14 that descends following the lowering of the element forming punch 13 is provided at a position facing the element forming punch 13. Further, a connecting portion forming punch 15 for forming the connecting portion 4 is provided on one side of the element forming punch 13. An escape portion 16 is formed in a part of the die 12 corresponding to the connecting portion forming punch 15. A pad 17 for pressing the plate material 3 on the die 12 is provided above the die 12.
[0019]
In the first processing apparatus 11, first, the plate material 3 placed on the die 12 is fixed on the die 12 by pressing the pad 17. Next, as shown in FIG. 3A, the element 1 is punched by the lowering of the element forming punch 13 while being held from below the plate 3 by the counter punch 14. At the same time, the connecting portion 4 is formed by the connecting portion forming punch 15 lowered together with the element forming punch 13 and the relief portion 16 on the die 12 side corresponding to the connecting portion forming punch 15.
[0020]
At this time, as shown in FIG. 1, an unsheared connecting portion 4 is formed at a substantially central position of the body 6 of the element 1, and the periphery of the element 1 other than the portion where the connecting portion 4 is formed is highly accurate. Sheared. As shown in FIG. 2, the element 1 is formed in a state of being connected to the plate material 3 in a horizontal posture below the substantially thickness dimension of the plate material 3, and the connecting portion 4 includes the connecting portion forming punch 15 and the relief portion 16. As a result, the thickness b of the plate 3 is formed so as to be inclined toward the element 1 with almost no change. At this time, as shown in FIG. 1, the width c of the connecting portion 4 is 1 to 3 times the thickness b of the plate 3 shown in FIG. 2.
[0021]
Subsequently, as shown in FIG. 3B, the element 1 is connected via the connecting portion 4 by raising the element forming punch 13, the connecting portion forming punch 15, the counter punch 14, and the pad 17. The plate material 3 is taken out and supplied to the second processing apparatus 18 shown in FIG.
[0022]
Subsequently, the second processing apparatus 18 performs a separation step described later for separating the element 1 from the plate material 3. As shown in FIG. 4, the second processing apparatus 18 includes a separate die 19 on which the plate material 3 is placed, and a separate punch 20 that punches and cuts the connecting portion 4 from the plate material 3 on the separate die 19. ing. A discharge path 21 for discharging the element 1 separated from the plate material 3 is formed at a lower position facing the separate punch 20. Further, a relief portion 22 is formed in a part of the separate die 19 corresponding to the connecting portion 4. A pad 23 for pressing the plate material 3 on the separate die 19 is provided above the separate die 19.
[0023]
In the second processing apparatus 18, first, the plate material 3 supplied onto the separate die 19 is fixed onto the separate die 19 by pressing the pad 23. Next, as shown in FIG. 4, the separation punch 20 is lowered and punched and cut along the boundary between the connecting portion 4 and the element 1 (the boundary a indicated by the phantom line in FIG. 1). As a result, the element 1 is separated from the plate material 3 and is dropped and discharged through the discharge path 21.
[0024]
In the element 1 formed as described above, since the concave portion 8 and the V surface 10 that require high accuracy are reliably sheared by the first processing device 11 in the punching step, the accuracy is sufficiently maintained. Yes. Further, the element 1 is connected to the plate material 3 processed by the first processing device 11 via the connecting portion 4, and the width c of the connecting portion 4 is 1 to 3 of the thickness dimension b of the plate material 3. Since it is doubled, the connection portion 4 is not bent or cracked by the weight of the element 1, and the plate 3 can be supplied to the second processing device 18 while maintaining a good posture of the element 1. . Moreover, since the width dimension c of the connecting portion 4 is 1 to 3 times the thickness dimension b of the plate member 3, the cutting resistance when punching by the separate punch 20 is reduced, and the element 1 is smoothly separated from the plate member 3. Can be done. Further, the position where the connecting portion 4 is provided is between both V surfaces 10 of the body 6, and the connecting portion 4 is inclined and continues to the element 1, so that it is sufficient for the body 6 of the element 1. Thickness (equivalent to the thickness dimension b which the board | plate material 3 has) is ensured, and the connection part 4 can be cut | disconnected without deform | transforming the element 1. FIG.
[0025]
And, there is a possibility that sagging occurs at the time of punching and cutting of the connecting part 4, but the connecting part 4 is provided between the two V surfaces 10, that is, in the element 1 at the position where the most accuracy is not required. The function of element 1 is not affected at all. Further, since the periphery of the head 5 of the element 1 is sheared with high accuracy by the punching process, the flatness of the head 5 is ensured satisfactorily. Thereby, although not illustrated, when a plurality of elements 1 are stacked in a ring shape, the stacking direction does not bend toward the head 5 side and goes in the direction opposite to the circumferential direction, so that stacking accuracy can be improved.
[Brief description of the drawings]
FIG. 1 is an explanatory plan view showing a punching shape of a plate material by a punching process according to an embodiment of the present invention.
2 is a cross-sectional view taken along line II-II in FIG.
FIG. 3 is an explanatory view schematically showing a punching process of the embodiment.
FIG. 4 is an explanatory view schematically showing a separation process of the embodiment.
FIG. 5 is an explanatory diagram showing the shape of an element.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Element, 2 ... Endless ring, 3 ... Plate material, 4 ... Connection part, 5 ... Head, 6 ... Body, 8 ... Recessed part, 9 ... Pulley, 10 ... V surface.

Claims (2)

Through a pair of recesses for mounting a body having V surfaces on both sides that are located on the inner peripheral side and are in contact with the pulley of the continuously variable transmission when stacked in a ring shape, and a pair of endless rings that are bundled in a ring shape In the punching method of the element of the belt for continuously variable transmission, comprising a head that is connected to the body and is positioned on the outer peripheral side when a plurality of layers are annularly stacked,
A punching process in which the element is formed by punching a part of a metal plate in a connected state via a connecting part;
A separation step of separating the element from the plate by punching and cutting the connecting portion formed by the punching step along a boundary with the element;
In the punching step, the connecting portion is formed at a position between both V surfaces of the body, and the element is punched in a posture shifted by at least the thickness dimension of the plate material in the punching direction. The connecting portion is inclined and connected to the element without changing the plate thickness so that the element can secure the thickness of the plate material . 2. The punching process for an element of a continuously variable transmission belt according to claim 1 , wherein, in the punching step, the connecting portion is formed to have a width of 1 to 3 times the thickness of the plate member. Method.

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