JP3983998B2 - Belt element for continuously variable transmission and punching method thereof - 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]
An element constituting a continuously variable transmission (CVT) belt includes a body having a V surface in contact with a pulley of a continuously variable transmission, and a head connected to an upper portion of the body via a neck. The head is provided with ears protruding on both sides so as to face the upper edge of the body, and a recess is formed between the ears located on both sides of the neck and the body. In addition, a thin-walled portion whose plate thickness gradually decreases toward the lower edge is formed in the substantially lower half of the body. A plurality of the elements are laminated in a ring shape, and are bound to the recesses in a ring shape by a metal band-like endless ring. At this time, the body is positioned on the inner peripheral side of the belt and the head is positioned on the outer peripheral side of the belt.
[0003]
This type of element is usually formed by punching a long metal plate placed on a die of a press apparatus with a forming punch. At this time, the thin portion is simultaneously pressed and deformed so that the thin portion has a predetermined cross-sectional shape by the counter punch abutting against the back surface of the plate material. Then, hundreds of the punched elements are stacked in an annular shape, and an endless ring is attached to the concave portion, and assembled into a continuously variable transmission belt.
[0004]
By the way, when a continuously variable transmission belt formed by this type of element is stretched between a pair of pulleys and rotated, it converges on the body side of each element in a portion that draws an arc along the pulleys. In addition, it is preferable that the elements rotate in a state where the elements are linearly stacked in a portion that becomes a string between the pulleys. For this reason, each element forms the thin portion with high precision by the counter punch at the time of the aforementioned punching molding so as to smoothly draw an arc along the pulley.
[0005]
However, when the thin portion is pressed and deformed by the counter punch for forming the thin portion, the surplus material generated at this time flows and swells to the upper half of the body, and the thickness of the body increases. If the increase in the plate thickness at this time becomes larger than the plate thickness of the head (including ears), the plate thickness on the body side becomes larger than the plate thickness on the head side. For this reason, in the part which becomes a string between the pulleys mentioned above, it becomes easy to bend in the shape where each element converges to the head side, and it becomes difficult to maintain a lamination posture in a straight line state. In this state, the continuously variable transmission belt that rotates between the pulleys is not only able to perform stable power transmission in the continuously variable transmission due to vibration, but also the endless ring in the recess of the element. There is a risk of damaging the element and endless ring due to strong contact with the lower edge of the ear.
[0006]
[Problems to be solved by the invention]
In order to eliminate such inconveniences, the present invention has an object to provide a highly accurate element that can form a good lamination state and can stably transmit power in a continuously variable transmission. It is an object of the present invention to provide a punching method for an element of a continuously variable transmission belt that can be easily obtained.
[0007]
[Means for Solving the Problems]
In order to achieve such an object, the present invention provides a body that is positioned on the inner peripheral side when a plurality of layers are annularly stacked in the thickness direction and whose left and right end edges are in contact with a pulley of a continuously variable transmission, and a center of the body. A thin-walled portion formed on the upper edge side of the body through a neck and having a head positioned on the outer peripheral side when a plurality of layers are laminated in an annular shape, and the plate thickness is formed thinner than the other portions in the substantially lower half of the body In the element of the belt for continuously variable transmission, the thickness of the left and right side end portions of the head positioned on both sides of the upper region of the neck is larger than that of the upper region of the neck. And the thickness of the body is smaller than the thickness of the head, and the upper half of the body excluding the thin-walled portion has the left and right end portions of the body located on both sides of the lower region of the neck. The plate thickness is smaller than the lower area of the neck. It is characterized in that is.
[0008]
When a belt for a continuously variable transmission is formed by laminating a plurality of elements in an annular shape, the neck and the body that are smaller than the thickness of the head make a curved deformation toward the inner periphery of the continuously variable transmission belt. Can be smoothly performed, and the stacking direction of each element can be made a good stacking shape without bending to the head side. When the continuously variable transmission belt is formed and stretched over the pulley of the continuously variable transmission, the continuously variable transmission belt can be prevented from swinging in the outer circumferential direction. Thus, stable power transmission in the continuously variable transmission can be performed. In addition, when a plurality of elements are stacked in a ring shape, the relatively thick portions, that is, the left and right side end portions of the head and the lower portion of the neck of the body are in contact with adjacent elements, which makes it extremely stable. Thus, when a continuously variable transmission belt is formed, meandering or the like can be prevented and efficient power transmission can be performed.
[0009]
The present invention is a punching method for obtaining an element having the above-described configuration, and has the following features. That is, a metal plate placed on a die is pushed down from the upper surface thereof and punched into the shape of the element, and a counter load is applied by abutting against the lower surface of the element punched by the molding punch. A counter punch that descends with the element while pressing and deforming the part into a predetermined cross-sectional shape is used.
[0010]
A step of pressing down the plate material by the forming punch and pressing and deforming the thin portion into a predetermined shape by a counter load of the counter punch that opposes a pressing load of the forming punch; A step of causing surplus material accompanying the pressing deformation of the thin wall portion to flow from the body to the plate material positioned on both sides of the neck by the counter load of the counter punch that opposes the pressing load of the punch, and further pressing down the plate material by the forming punch A step of separating the plate from which the surplus material has flowed out from the body and punching the element while pressing the substantially central portion of the head to cause a flow of meat at the left and right end portions of the head. Thereby, the plate thickness of the left and right side end portions of the head located on both sides of the upper region of the neck of the head is made larger than the upper region of the neck, and the plate thickness of the neck and the body is set to the head. Further, in the substantially upper half portion excluding the thin wall portion of the body, the plate thickness at the left and right end portions of the body located on both sides of the lower region of the neck is made smaller. Form an element.
[0011]
According to the present invention, when the molding punch is pressed, surplus due to the pressure deformation of the thin portion is caused to flow out to the plate material between the body and the head by the counter load of the counter punch, and then the surplus is received. Since the plate material is separated from the body, it is possible to reliably prevent an increase in the plate thickness of the body without remaining surplus in the body in an expanded state. On the other hand, the surplus generated in the lower region of the neck in the substantially upper half of the body moves to the neck side and is dispersed, but there is little meat flow toward the plate to be separated. Thereby, the plate thickness of the left and right side end portions of the body located on both sides thereof can be easily made smaller than the plate thickness of the lower region of the neck in the substantially upper half of the body.
[0012]
In this way, the excess load generated in the body can be easily discharged to the outside of the element by the pressing load of the molding punch and the counter load of the counter punch, or can be dispersed to the neck, so that the left and right ends of the head The thickness of the portion can be increased, and the plate thickness on the body side can be easily made thinner than the plate thickness on the head side. At the same time, the plate thickness of the body located on both sides of the body can be easily made smaller than the plate thickness in the lower region of the neck in the substantially upper half of the body. As a result, when a continuously variable transmission belt is formed by laminating a plurality of elements in an annular shape, the elements in which the lamination direction of the elements does not bend toward the head side are punched out. Can do.
[0013]
In the present invention, the plate material punched out by the forming punch is pressed onto the die by a pad, and the pressing force of the plate material by the pad is a surplus due to the pressing load of the forming punch and the counter load of the counter punch. It is preferably set to a load that allows meat to flow out. As a result, the surplus material generated in the body can be smoothly discharged to the outside of the element.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory plan view showing a punching shape of a plate material according to this embodiment, FIGS. 2 and 3 are explanatory views schematically showing a punching process according to this embodiment, and FIG. 4A is formed according to this embodiment. 4B is a plan view of the element, and FIG. 4B is an arrow b view of FIG.
[0015]
The punching method of the present embodiment is employed when manufacturing the element 1 (see FIG. 4) constituting a continuously variable transmission belt (not shown). Although not shown, the element 1 is laminated in a ring shape and is integrally bound by a metal endless ring to form a continuously variable transmission belt.
[0016]
In the present embodiment, as shown in FIG. 1, after performing a punching process of punching the element 1 from the metal plate material 2 via the connecting portion 3, the connecting portion 3 and the element 1 indicated by the phantom line a in the drawing. A separation step of separating the element 1 from the plate material 2 by cutting along the boundary is performed. The shape of the element 1 formed at this time will be briefly described with reference to FIGS. 4A and 4B. The element 1 has an outer periphery when the continuously variable transmission belt is formed. A head 4 positioned on the side, and a body 5 positioned on the inner peripheral side. The head 4 and the body 5 are integrally connected via a neck 6. A pair of ears 7 projecting along the upper edge of the body 5 are formed on both sides of the head 4. A substantially central portion of the head 4 is formed with a nose 8 and a hole 9 for engaging the concave and convex portions next to each other when the plurality of elements 1 are stacked. A slight recess 10 is formed around the hole 9 of the head 4 in order to ensure engagement with the nose 8, so that the central portion of the head 4 is slightly smaller than the ear 7. The plate thickness is small.
[0017]
A pair of recesses 11 is formed between the ear 7 and the body 5 located on both sides of the neck 6. Each recess 11 is fitted with the endless ring described above. A pair of pulley contact surfaces 12 (V surfaces) that contact a pulley of a continuously variable transmission (not shown) are formed at both ends of the body 5. Furthermore, a thin portion 13 whose thickness is gradually reduced toward the lower edge is formed in the lower half of the body 5.
[0018]
Next, the punching process will be described. The punching process is performed by a press device 14 shown in FIGS. 2 (a) and 2 (b). The pressing device 14 includes a die 15 on which the plate material 2 is placed, and an element forming punch 16 for punching the plate material 2 on the die 15 into an element shape. A counter punch 17 that descends following the lowering of the element forming punch 16 is provided at a position facing the element forming punch 16. Further, a connecting portion forming punch 18 for forming the connecting portion 3 is provided on one side of the element forming punch 16. An escape portion 19 is formed in a part of the die 15 corresponding to the connecting portion forming punch 18. Further, a pad 20 for pressing the plate material 2 on the die 15 is provided above the die 15.
[0019]
In the pressing device 14, first, the plate member 2 placed on the die 15 is fixed on the die 15 by pressing the pad 20. Next, as shown in FIG. 2A, the element 1 is punched by the lowering of the element forming punch 16 while being held from below the plate 2 by the counter punch 17. At the same time, the connecting portion 3 is formed by the connecting portion forming punch 18 lowered together with the element forming punch 16 and the relief portion 19 on the die 15 side corresponding to the connecting portion forming punch 18.
[0020]
Further, as shown in FIGS. 3A to 3D, the element forming punch 16 is moved downward until the element 1 is separated from the plate 2 after the portion excluding the connecting portion 3 is punched. Is done. First, as shown in FIGS. 3A and 3B, the thin portion 13 of the body 5 has a predetermined cross-sectional shape due to the pressing load of the element forming punch 16 and the counter load of the counter punch 17. It is pressed and deformed. When the thin portion 13 is pressed and deformed, the surplus portion flows to the upper half portion 21 of the body 5.
[0021]
Next, as shown in FIG. 3C, the surplus material flows out in the direction toward the head 4 by the pressing load of the element forming punch 16 and the counter load of the counter punch 17 (see the arrow in FIG. 1). As a result, at both side positions of the body 5 (particularly point A in the figure), surplus material flows out to the plate member 2 located in the recess 11. In addition, although the pressing load is given to the board | plate material 2 located in this recessed part 11 by the said pad 20, by making the load into the magnitude | size which does not prevent the outflow of the surplus from the body 5, surplus can be made smooth. Can be drained.
[0022]
Further, surplus material generated in the region below the neck 6 in the body 5 (particularly, point B in the figure) does not flow out into the recess 11 but flows and disperses along the neck 6 toward the head 4. At this point, the plate thickness at point A is smaller than the plate thickness at point B.
[0023]
On the other hand, on the head 4 side, as shown in FIG. 1, the nose 8 and the hole 9 are formed by the pressing of the element forming punch 16, and the periphery of the hole 9 is further pressed and slightly crushed. Is formed. As a result, as shown by the arrows in FIG. In the ear 7 (particularly, point C in the figure), the thickness increases from the original plate thickness of the plate material, so that the plate thickness at point B is the same as the plate thickness at point C. The plate thickness at point C is greater than the thickness.
[0024]
Then, as shown in FIG. 3 (d), when the element 1 is punched, the surplus material that has flowed into the recess 11 is separated from the element 1 while remaining in the plate 2 located in the recess 11. .
[0025]
Subsequently, as shown in FIG. 2B, the element 1 is connected via the connecting portion 3 by raising the element forming punch 16, the connecting portion forming punch 18, the counter punch 17, and the pad 20. The plate material 2 is taken out. And the isolation | separation process which cut | disconnects the connection part 4 is performed, and the element 1 is isolate | separated from the board | plate material 2 completely.
[0026]
As shown in FIG. 4 (b), the element 1 formed in this way is surely smaller in the thickness of the point A than the thickness of the point B, and more in the point B than the thickness of the point C. The plate thickness is the same or small . Thereby, although not shown, when a continuously variable transmission belt is formed by laminating a plurality of elements 1 in an annular shape, a stable lamination state can be achieved by contact between both points C and B, Since it is possible to reliably prevent each element 1 from being bent so as to converge on the head 4 side, there is no damage to the element 1 due to unnecessary contact with the endless ring when it is stretched over the pulley of the continuously variable transmission, Stable power transmission in the continuously variable transmission can be performed.
[Brief description of the drawings]
FIG. 1 is an explanatory plan view showing a punching shape of a plate material according to an embodiment of the present invention.
FIG. 2 is an explanatory view schematically showing a punching process according to the present embodiment.
FIG. 3 is an explanatory view schematically showing a punching process according to the present embodiment.
FIG. 4 is an explanatory view showing elements formed according to the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Element, 2 ... Board | plate material, 4 ... Head, 5 ... Body, 6 ... Neck, 12 ... Pulley contact surface (V surface), 13 ... Thin part, 15 ... Die, 16 ... Element molding punch (molding punch), 17 ... counter punch, 20 ... pad.

Claims (3)

When a plurality of layers are laminated in the thickness direction, the body is located on the inner peripheral side and the left and right side edges are in contact with the pulley of the continuously variable transmission, and is connected to the upper edge side of the central portion of the body via a neck, A continuously variable transmission belt element having a thin-walled portion formed thinner than the other portion in a substantially lower half of the body, the head positioned on the outer peripheral side when a plurality of layers are annularly stacked;
In the head, the plate thickness of the left and right end portions of the head located on both sides of the upper region of the neck is larger than the upper region of the neck,
The plate thickness of the neck and the body is smaller than the plate thickness of the left and right end portions of the head,
In the substantially upper half portion excluding the thin portion of the body, the plate thickness of the left and right end portions of the body located on both sides of the lower region of the neck is smaller than the lower region of the neck. The belt element for a continuously variable transmission. When a plurality of layers are laminated in the thickness direction, the body is located on the inner peripheral side and the left and right side edges are in contact with the pulley of the continuously variable transmission, and is connected to the upper edge side of the central portion of the body via a neck, Punching of elements of a belt for continuously variable transmission, which has a head positioned on the outer peripheral side when a plurality of layers are laminated in an annular shape, and has a thin-walled portion formed thinner in the lower half of the body than other portions A processing method,
A metal punch placed on the die is pressed down from the upper surface to punch into the shape of the element, and a counter load is applied by abutting against the lower surface of the element punched by the molding punch, and the thin portion is Using a counter punch that descends with the element while being pressed and deformed into a predetermined cross-sectional shape,
A step of pressing and deforming the thin-walled portion into a predetermined shape by a counter load of the counter punch that opposes a pressing load of the forming punch while pushing down the plate material by the forming punch; and
A step of further pressing down the plate material by the molding punch and causing the counter load of the counter punch to oppose the pressing load of the molding punch to flow out surplus due to the press deformation of the thin portion from the body to the plate material positioned on both sides of the neck; Further, the plate material is further pushed down by the forming punch to separate the plate material from which the surplus material has flowed out from the body, and the substantially central portion of the head is pressed to generate a meat flow at the left and right end portions of the head. By the process of punching the element,
The plate thickness of the left and right side end portions of the head located on both sides of the neck upper region of the head is larger than the neck upper region, and the plate thickness of the neck and the body is the plate thickness of the head. The plate thickness of the left and right end portions of the body located on both sides of the lower region of the neck is smaller than that of the lower region of the neck in the substantially upper half portion excluding the thin portion of the body. A method for punching an element of a belt for a continuously variable transmission, wherein the element is formed. The plate material punched by the molding punch is pressed onto the die by a pad,
3. The continuously variable transmission according to claim 2, wherein the pressing load of the plate material by the pad is set to a load that allows the excess material to flow out due to the pressing load of the forming punch and the counter load of the counter punch. Punching method for belt elements.

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