JP2010240657A - Mold for punching element for cvt belt and punching method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold for punching an element for a CVT belt capable of carrying out punching without causing failure in appearance in the element and of improving die life, and also to provide a punching method. <P>SOLUTION: The die comprises a die 2 and a punch that are used when punching the element for the CVT belt from a plate-like material. The punch has an outer shape corresponding to the contour shape of the element and has a punch blade at a tip angle part. The die 2 has a punching hole 20 corresponding to the contour shape of the element and is divided into two or more die parts 2a, 2b, and the outer circumferential side is constrained by a constraining mold. The dividing plane 31 between the die parts 2a, 2b is tilted at a predetermined angle in a punching direction at least in an area having a dimension equal to or more than the thickness dimension of the element from the opening end of the punching hole 20. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a punching die used when manufacturing an element used for a CVT belt and a punching method using the die.

  A belt-type CVT (Continuously Variable Transmission) is composed of a pair of pulleys and a CVT belt that spans the pulleys. The CVT belt is configured by mounting a large number of friction parts called elements on a ring-shaped belt made of a metal strip.

  As shown in FIG. 1 to be described later, the element 8 includes a substantially triangular head 81, a substantially rectangular trunk 82, a center portion of the bottom of the head 81, and a long side of the trunk 82. The neck part 83 which connects with the center part of this. On the left and right sides of the neck portion 83, concave portions 85 formed by a gap between the head portion 81 and the trunk portion 82 are formed. A CVT belt can be obtained by inserting a belt (not shown) made of a metal strip into the recess 85 and disposing the element 8 all around the belt.

The element 8 is manufactured by a process of preparing a plate-shaped metal material, punching it into a desired shape, and then performing a finishing process. The punching process of the element 8 is performed using a die composed of a die and a punch.
As a conventional mold, for example, there is one disclosed in Patent Document 1.

JP-T-2005-531738

  The die constituting the mold has a punched hole corresponding to the above-described special shape of the element 8, and there are a plurality of locations where stress is likely to concentrate during punching. Therefore, by repeating the punching process, cracks may occur in the stress concentration portion, and the die life may be exhausted early.

  As a countermeasure against this, it is conceivable to prevent the occurrence of cracks by forming a single die by combining a plurality of die parts divided at a portion where stress concentration is likely to occur. However, in this case, stress is applied in the direction of separating the die parts even at a slight amount at the position of the dividing surface, and a streak pattern at the position of the dividing surface is formed on the side surface of the punched element. If this streak pattern is strong, it may not be adopted as an element and must be regarded as defective. Therefore, conventionally, a method of dividing one die into a plurality of die parts cannot be adopted.

  The present invention has been made in view of the above-described conventional problems, and can punch a CVT belt element that can be punched without causing defects in appearance and can improve the die life. It is intended to provide a metal mold and a punching method.

1st invention is comprised by the substantially triangular head, the substantially rectangular trunk | drum, and the neck part which connects the center part of the base part of the said head part, and the center part of the long side part of the said trunk | drum part. A die composed of a die and a punch used for punching a CVT belt element from a plate material,
The punch has an outer shape corresponding to the contour shape of the element, and a punch blade is provided at a corner of the tip.
The die has a punched hole corresponding to the contour shape of the element and is divided into two or more die parts, and the outer peripheral side thereof is restrained by a restraint die.
In addition, the dividing surface between the die parts is in a die for punching a CVT belt element, which is inclined at a predetermined angle with respect to the punching direction (Claim 1).

  According to a second aspect of the present invention, there is provided a method for punching a CVT belt element, wherein a plate-shaped material is punched using the mold according to the first aspect of the present invention.

  The die of the present invention is divided into a plurality of die parts as described above, and the divided surface is inclined at a predetermined angle with respect to the punching direction as described above. As a result, it is possible to suppress a decrease in die life due to stress concentration, and it is possible to prevent appearance defects from occurring in the punched element.

That is, since the die is divided into a plurality of die parts, the stress concentration can be absorbed by the dividing position, and the occurrence of cracks in the die can be prevented. Moreover, the dividing surface between the die parts is inclined obliquely with respect to the punching direction. Thereby, when the element to be punched passes through the punching hole of the die, the position in contact with the dividing surface between the die parts is gradually shifted. Therefore, it is possible to suppress the occurrence of a streak pattern on the end face of the element to be obtained, thereby preventing appearance defects.
As described above, according to the present invention, the element can be punched without causing appearance defects, and the die life can be improved.

FIG. 3 is a perspective view showing a CVT belt element in the first embodiment. FIG. 3 is a perspective view showing a punch in the first embodiment. The perspective view which shows the dice | dies in Example 1. FIG. The perspective view which shows the dice | dies of the state restrained by the restraint type in Example 1. FIG. The side view of the dice | dies in Example 1. FIG. In Example 1, (a) The perspective view of a 1st die component, (b) The perspective view of a 2nd die component. FIG. 3 is a perspective view of a punched CVT belt element according to the first embodiment. Explanatory drawing which shows the side part of the corner | angular part of an element head in Example 1. FIG. The perspective view which shows the dice | dies in the comparative example 1. FIG. The side view of the dice | dies in the comparative example 1. FIG. Explanatory drawing which shows the side part of the corner | angular part of the element head in the comparative example 1. FIG. The perspective view which shows the dice | dies in Example 2. FIG. The side view of the dice | dies in Example 2. FIG. (A) The perspective view of the 1st die part in Example 2, (b) The perspective view of the 2nd die part. The perspective view which shows the dice | dies in Example 3. FIG. In Example 3, (a) The perspective view of a 1st die component, (b) The perspective view of a 2nd die component. The perspective view which shows the dice | dies in Example 4. FIG. (A) The perspective view of the 1st die part in Example 4, (b) The perspective view of the 2nd die part, (c) The perspective view of the 3rd die part. The perspective view which shows the dice | dies in Example 5. FIG. FIG. 20 is a sectional view taken along the line BB in FIG. The perspective view which shows the dice | dies in Example 6. FIG. The CC sectional view taken on the line of FIG. 21 in Example 6. FIG. The top view which shows the dice | dies in Example 7. FIG. Explanatory drawing of dice | dies in Example 7. FIG. The top view which shows the dice | dies in Example 8. FIG. Explanatory drawing of dice | dies in Example 8. FIG.

In the die for punching a CVT belt element according to the present invention, the dividing surface of the die is inclined at a predetermined angle with respect to the punching direction at least in a region greater than the thickness dimension of the element from the opening end of the punching hole. ing. In other words, the slope of the dividing surface only needs to be formed within a range that contacts the inner surface of the punched hole when the element is punched. Of course, the entire surface of the dividing surface may be a single inclined plane, which also provides the advantage of easier die fabrication.
In addition, the dies are usually subjected to a re-grinding process in which the surface is polished and regenerated after being worn to some extent, but at least the re-polished region is preferably an inclined surface.

  Moreover, it is preferable that the inclination angle of the said dividing surface exists in the range of 0.04 degrees-20 degrees. By being within this range, it is possible to easily realize both the punching quality and the improvement of the die life. When the inclination angle is less than 0.04 °, the streak-inhibiting effect may be reduced. On the other hand, when the inclination angle exceeds 20 °, the strength of the die may be reduced.

  Further, the split mold may have a structure that covers the entire outer peripheral surface of the integrated die part, or may have a structure that presses only a plurality of locations on the outer peripheral surface. Moreover, the thing of an integral structure may be sufficient and the thing of the structure divided | segmented into plurality may be sufficient. Moreover, it is also preferable that it is divided into a plurality of parts and the pressing force (clamping force) can be adjusted.

Moreover, it is preferable that the said division | segmentation surface consists of a surface which passes along the corner | angular part corresponding to the corner | angular part of the said element in the said punching hole. Since the corner of the punched hole corresponding to the corner in the contour shape of the element is likely to cause stress concentration at the time of punching, it is effective to prevent the occurrence of cracks by providing the dividing surface in advance.
As the corners, there are three vertex portions that constitute a substantially triangular shape of the head portion, and portions that correspond to the four vertex portions that constitute a substantially rectangular shape of the trunk portion. The corner of the contour of the element has an appropriate curved shape at the tip. Therefore, when providing a split surface passing through the corner, the split surface may be provided so as to pass through the curved surface shape portion at the tip of the corner.

Preferably, at least one of the divided surfaces is a surface passing through at least one of the corners corresponding to the corner of the head in the punched hole. Of the corners of the punched holes corresponding to the corners of the head, the corners at both ends of the bottom are particularly where stress concentration occurs and cracks easily occur, and the formation of the split surface is extremely high. It is valid.
Moreover, various forms can be adopted as the dividing plane passing through the corners of the head as shown in the examples described later.

Further, it is preferable that at least one of the divided surfaces is a surface passing through at least one of the corner portions corresponding to the corner portions of the body portion in the punched hole. The corners of the punched holes corresponding to the corners at both ends of the body are also portions where stress concentration occurs relatively easily and cracks are easily formed, and the formation of the divided surfaces is very effective.
Further, the split surface passing through the corners at both ends of the body portion can be constituted by two surfaces parallel to the side surfaces on both sides of the body portion.
Of course, it is possible to provide both of the above-described dividing plane passing through the corner of the head and the dividing plane passing through the corner of the trunk.

Moreover, it is preferable that a surface treatment film for improving wear resistance is formed on the inner surface of the die punching hole. As described above, since the die of the present invention can be divided into a plurality of die parts, the inner surface of the punched hole can be easily surface-treated as compared with the case where the die is not divided. By utilizing this, it is preferable to form a surface treatment film for improving wear resistance on the inner surface of the punched hole.
Specific examples of the surface treatment film include TiN, TiCN, and DLC.

  Moreover, it is preferable that the outer peripheral side surface of the die and the inner peripheral surface of the constraining die facing the die have a tapered shape that gradually decreases in diameter along the punching direction. Although the said die | dye comprises one dice combining several die components, the circumference | surroundings are restrained by the said restraint type | mold. In order to further strengthen the restraining force, it is preferable that the outer peripheral side surface of the die and the inner peripheral surface of the constraining die are tapered as described above. And as above-mentioned, it is preferable that the taper-shaped inclination direction is made into the direction gradually diameter-reducing along a punching direction. Thereby, by adopting a configuration that holds the die while fixing the constraining die, the stress at the time of punching works in a direction in which the die parts are brought into close contact with each other, and the integrated state of the die can be further stabilized. .

Example 1
A punching die for a CVT belt element and a punching method according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the CVT belt element 8 punched in this example includes a substantially triangular head 81, a substantially rectangular trunk 82, a central portion of the bottom of the head 81, and the trunk 82. It is comprised by the neck part 83 which connects the center part of the long side part. As shown in the figure, the element 8 has a protrusion 815 at the center of the head 81. When a plurality of elements 8 are stacked, the protrusion 815 of the adjacent element 8 is inserted into the recess on the back side of the protrusion 815. It is configured to facilitate positioning. A recess 85 is formed between the head 81 and the body 82, and a belt (not shown) is inserted therein.

The die of this example used when the element 8 is punched from a plate material is composed of a die 2 (FIGS. 3 and 4) and a punch 1 (FIG. 2).
As shown in FIG. 2, the punch 1 has an outer shape corresponding to the contour shape of the element 8. The punch 1 is provided with a substantially right punch blade 17 at the corner of the tip, and cuts the head 81. A punch head portion 11 for cutting the body portion 82, and a punch neck portion 13 for cutting the neck portion 83. In addition, the punch head 11 is provided with a pin hole 18 into which a pin for forming a protrusion 815 of the element 8 and a recess on the back surface thereof is inserted.

The die 2 has a punched hole 20 corresponding to the contour shape of the element 8 as shown in FIGS. 3 to 6 and is divided into two die parts 2a and 2b. It is restrained by 29.
As shown in FIGS. 3 to 6, the dividing surface 31 between the die parts 2 a and 2 b passes through both corners of the position corresponding to the head 81 on the opening side of the punching hole 20, and the bottom of the head 81. It consists of a plane parallel to. The entire surface of the dividing surface 31 is inclined at a predetermined angle α (α = 0.5 °) with respect to the punching direction A (FIG. 5). It is represented by a single oblique straight line that is inclined in the direction penetrating the center of the head 81, the neck 83, and the trunk 82 (hereinafter referred to as the element axial direction).

  As shown in FIG. 6, the die part 2 a has portions of the punched hole 20 corresponding to the vicinity of the bottom portion of the body portion 82, the neck portion 83, and the head portion 81 of the element 8. The die part 2b has a portion corresponding to most of the apex portion of the head portion 81 of the element 8 and the two side portions sandwiching the die portion 2 in the punching hole 20. And since the dividing surface 31 between these die parts 2a and 2b is inclined as described above, the width of the part corresponding to the head 81 in the die parts 2a and 2b increases as the distance from the opening of the punching hole 20 increases. It has changed.

  In addition, a surface treatment film for improving wear resistance is formed on the entire inner surface of the punched hole 20 of the die part 2a and the die part 2b. Specifically, a TiN film was applied by physical vapor deposition (PVD). In place of TiN, TiCN or DLC may be employed. In this example, the surface treatment film is a film made of the above material by the above method, but can be changed to various known surface treatment films having an effect of improving wear resistance.

Further, as shown in FIGS. 3 and 4, the outer shape of the die, which is a combination of the die parts 2a and 2b, is a rectangular parallelepiped shape, and the constraining die 29 arranged on the outer periphery thereof is a rectangular tube, and the void portion inside thereof is formed. It corresponds to the above rectangular parallelepiped shape. The die 2 and the constraining die 29 can be fitted to each other substantially without a gap by shrink fitting or the like.
In this example, the integral type constraining die 29 that covers the entire circumference of the die parts 2a and 2b is adopted. However, as long as the restraining force can be ensured, a configuration that clamps a plurality of locations on the outer periphery, and other various types Needless to say, the configuration can be changed. This is the same in other embodiments.

  Next, using the punch 1 and the die 2, the element 8 was punched from a plate-shaped material made of steel. Then, as shown in FIGS. 7 and 8, the side surface portions M of the both end corner portions 812 of the head portion 81 of the obtained element 8 were observed. This portion is a position punched by a portion corresponding to the dividing surface 31 between the die parts 2a and 2b in the punching hole 20. As is known from FIG. 7, the element 8 punched out using the mold of this example did not have a streak pattern that would cause a problem at the position corresponding to the dividing surface 31.

Further, in the die 2 of this example, since the dividing surface 31 is provided and divided into two die parts 2a and 2b in advance, even if it is used repeatedly, punching corresponding to both end corners 812 of the head 81 is performed. Inadvertent cracking of the die can be prevented near the corner of the hole 20.
Therefore, if the die of this example is used, the element can be punched without causing appearance defects, and the life of the die 2 can be improved as compared with the conventional case. Furthermore, since a surface treatment film having an effect of improving wear resistance is formed on the entire inner surface of the punched hole 20, the life of the die 2 can be improved in this respect as well.

(Comparative Example 1)
Next, as shown in FIGS. 9 and 10, for comparison with the first embodiment, the die is divided into two die parts 9a and 9b at the same positions as described above, and the dividing surface 95 is formed in the punching direction A. A die 9 having a parallel surface was prepared. The shape of the punched hole 20 is the same as that in the first embodiment. The periphery of the die parts 9a, 9b was constrained and integrated by a constraining die 29 similar to that in the first embodiment. Then, using the same die 9 and the same punch 1 as in Example 1, the element 8 was punched from the plate material.

The side part M (FIG. 7) of the both-ends corner part 812 of the head 81 of the obtained element 8 was observed. This portion is a position punched by the portion corresponding to the dividing surface 95 between the die parts 9a and 9b in the punching hole 20. As is known from FIG. 11, the streak pattern 7 in question was generated at the position corresponding to the dividing surface 95 in the element 8 punched out using the mold of this comparative example.
From this result, it can be seen that even if the die is divided to improve the life, it is difficult to maintain the quality of the element to be punched when the die is provided in parallel to the direction of punching the split surface.

(Example 2)
In this example, as shown in FIGS. 12 to 14, the form of the dividing surface of the die 2 of Example 1 is changed.
That is, as shown in the figure, the die 22 of this example has a punched hole 20 corresponding to the contour shape of the element 8 and is divided into two die parts 22a and 22b. The point that the outer peripheral side is constrained by the constraining die 29 and the point that the surface treatment film is formed on the inner surface of the punching hole 20 are the same as those in the first embodiment.

  The dividing surface 32 between the die parts 22 a and 22 b is a plane parallel to the bottom side of the head 81, passing through both corners of the position corresponding to the head 81 on the opening side of the punching hole 20. The dividing surface 31 is inclined from the upper end to the middle on the opening side in the element axial direction by a predetermined angle β (β = 2 °) with respect to the punching direction A (FIG. 13). Is a surface parallel to the punching direction A. Therefore, when the die 22 is observed from the side, it is represented by a line bent in the middle.

As shown in FIG. 14, the die part 22 a has portions corresponding to the bottom portion of the body portion 82, the neck portion 83, and the head portion 81 of the element 8 in the punching hole 20. Further, the die part 22b has a portion corresponding to most of the apex portion of the head 81 of the element 8 and the two side portions sandwiching the die portion in the punching hole 20. And the upper half part 32a of the division surface 32 between these die components 22a and 22b is inclined with respect to the punching direction A as described above. Therefore, within the range of the upper half portion 32a of the inclined dividing surface 32, the width of the portion corresponding to the head 81 in the die parts 2a and 2b changes as the distance from the opening of the punching hole 20 changes. Yes. Since the range of the lower half portion 32b of the dividing surface 32 is parallel to the punching direction A, the hole shape is constant.
Others are the same as in the first embodiment.

Also in this example, as in the first embodiment, the dicing surface 32 is provided on the die 22 and divided in advance into two die parts 22a and 22b. Inadvertent cracking of the die can be prevented in the vicinity of the portion 815.
Therefore, if the die of this example is used, the element can be punched without causing appearance defects, and the life of the die 22 can be improved as compared with the conventional case. Furthermore, the lifetime improvement effect by the surface treatment film | membrane of the inner surface whole surface of the punching hole 20 can also be acquired easily.

Example 3
In this example, as shown in FIGS. 15 and 16, the form of the dividing surface of the die 2 of Example 1 is changed.
That is, as shown in the figure, the die 23 of this example has a punched hole 20 corresponding to the contour shape of the element 8 and is divided into two die parts 23a and 23b.

  The dividing surface 33 between the die parts 23 a and 23 b is provided so as to divide the apex of the head 81, the neck 83, and the center of the body 82 on the opening side of the punching hole 20. The entire surface of the dividing surface 33 is inclined at a predetermined angle γ (γ = 2 °) with respect to the punching direction A (FIG. 15), and is orthogonal to the element axial direction when the die 22 is observed from the side surface. It is represented by one diagonal straight line that is inclined in the element width direction.

As shown in FIG. 16, the die part 23 a has a portion corresponding to half of the body portion 82, the neck portion 83, and the head portion 81 of the element 8 in the punching hole 20 as an opening portion. The same applies to the dice 23b. And the width dimension of both of them gradually changes as they move away from the upper end with the opening due to the inclined dividing surface 33.
The point that the outer peripheral side of the die is constrained by the constraining die and the surface treatment film is formed on the inner surface of the punching hole 20 are the same as those in the first embodiment.

In the case of this example, the dice 23 is provided with a dividing surface 33 and divided into two dice parts 23a and 23b in advance, so that even after repeated use, the dice are inadvertently near the apex of the head 81. It can prevent that a crack arises.
Therefore, if the die of this example is used, the element can be punched without causing a defect in appearance, and the life of the die 23 can be improved as compared with the prior art. Furthermore, the lifetime improvement effect by the surface treatment film | membrane of the inner surface whole surface of the punching hole 20 can also be acquired easily.

Example 4
In this example, as shown in FIGS. 17 and 18, the form of the dividing surface of the die 2 of Example 1 is changed.
That is, as shown in the figure, the die 24 of this example has a punched hole 20 corresponding to the contour shape of the element 8 and is divided into four die parts 24a to 24d by three dividing surfaces 34a to 34c. ing.

  The die part 24a and the dividing surface 34a between the die parts 24b and 24c pass through positions corresponding to both corners 812 (FIG. 7) of the head 81 on the opening side of the punching hole 20, and the bottom of the head 81 It consists of a plane parallel to. The entire surface of the dividing surface 34a is inclined by a predetermined angle α in the element axial direction with respect to the punching direction A (FIG. 17), and is the same as the dividing surface 31 in the first embodiment.

A dividing surface 34b between the die part 24b and the die part 24c passes through one of the corner parts corresponding to the corner part 822 (FIG. 7) in the body part 82, and is formed of a plane parallel to the element axis direction. The entire surface of the dividing surface 34b is inclined at a predetermined angle θ (θ = 2 °) in the element width direction with respect to the punching direction A.
Similarly, the dividing surface 34c between the die part 24d and the die part 24c is formed of a surface that passes through one of the corners corresponding to the corner 822 of the body 82 and is parallel to the element axial direction. The split surface 34c is provided on the target with the split surface 34b, and the entire surface is inclined with respect to the punching direction A by a predetermined angle θ in the element width direction.

As shown in FIG. 18, the die part 24 a has the same shape as the die part 2 b of Example 1, and corresponds to the apex part of the head 81 of the element 8 and the side part of the punched hole 20. Has a part. The die part 24 c has a part corresponding to the bottom side part of the body part 82 of the element 8. The die parts 24b and 24d have a symmetrical shape, and a portion of the punched hole 20 corresponding to a half in the width direction excluding the bottom portion of the head 81 of the element 8, the neck portion 83, and the bottom portion of the body portion 82. Have
The point that the outer peripheral side of the die is constrained by the constraining die and the surface treatment film is formed on the inner surface of the punching hole 20 are the same as those in the first embodiment.

In the case of this example, the die 24 is provided with three dividing surfaces 34a to 34c and previously divided into four die parts 24a to 24d. In addition, it is possible to prevent inadvertent cracks from occurring in the dies in the vicinity of the corner portions of the body portion 82.
Therefore, if the die of this example is used, the element can be punched without causing appearance defects, and the life of the die 24 can be improved as compared with the conventional case. Furthermore, the lifetime improvement effect by the surface treatment film | membrane of the inner surface whole surface of the punching hole 20 can also be acquired easily.

(Example 5)
As shown in FIGS. 19 and 20, the die 25 of this example has the same basic configuration as that of the fourth embodiment divided into four die parts 25 a to d by three dividing surfaces 35 a to 35 c. The shape was changed to a taper shape that gradually reduced in diameter along the punching direction. In accordance with this, the inner peripheral surface 299 of the constraining die 292 is also tapered so that the diameter gradually decreases along the punching direction.
Others are the same as in the fourth embodiment.

In the case of this example, one die 25 is configured by combining a plurality of die parts 25a to 25d, and the restraining force thereof is the outer periphery side surface 259 of the die 25 and the inner periphery of the restraint die 292 as described above. It can be improved by adopting a configuration in which the shape of the surface is tapered and the die is held by fixing the constraining die. And the stability at the time of punching can be improved by the improvement of the restraining force of the die parts 25a to 25d, and the punching quality can be further improved.
Other effects are the same as those of the first embodiment.

(Example 6)
As shown in FIGS. 21 and 22, the die 26 of this example has the same basic configuration as that of the fourth embodiment divided into four die parts 26 a to d by three dividing surfaces 36 a to 36 c, but the outer peripheral side surface 269 thereof. The shape was changed from a square to a circular shape, and further changed to a tapered shape that gradually reduced in diameter along the punching direction. In accordance with this, the inner peripheral surface 298 of the constraining die 293 is also formed in a circular taper shape whose diameter is gradually reduced along the punching direction.
Others are the same as in the fourth embodiment.

Also in this example, one die 26 is configured by combining a plurality of die parts 26a to 26d, and the restraining force thereof is the outer peripheral side surface 269 of the die 26 and the inner periphery of the restraint die 29 as described above. It can be improved by making the shape of the surface tapered. And the stability at the time of punching can be improved by the improvement of the binding force of the die part, and the punching quality can be further improved. Further, since the outer shape is not a square but a circle, it is easy to fit the die and the constraining die.
Other effects are the same as those of the first embodiment.

(Example 7)
As shown in FIGS. 23 and 24, the die 27 of this example is divided into four die parts 27a to 27d by four dividing surfaces 37a to 37d. These surroundings are constrained by a constraining die 294.
As shown in FIG. 24, the dividing surface 37a between the die part 27a and the die part 27b passes through a corner corresponding to the corner of the right end of the head 81 at the opening of the punched hole 20 when viewed from above, It consists of a plane in a direction rotated approximately 45 ° to the right from the element axis direction. The entire surface of the dividing surface 37a is inclined with respect to the punching direction. The inclination direction is a direction approaching the die part 27a as the distance from the opening end of the punching hole 20 increases.

  Further, as shown in the figure, the dividing surface 37b between the die part 27b and the die part 27c is a corner corresponding to the lower right corner of the body 82 in the opening of the punched hole 20 when viewed from above. , And a plane that is rotated approximately 135 ° to the right from the element axial direction. The entire surface of the dividing surface 37b is inclined with respect to the punching direction. The inclination direction is a direction closer to the die part 27 c as it is away from the opening end of the punching hole 20.

  Further, as shown in the figure, the dividing surface 37c between the die part 27c and the die part 27d is a corner corresponding to the corner of the lower left corner of the body part 82 at the opening of the punched hole 20 when viewed from above. , And a plane in a direction rotated approximately 135 ° to the left from the element axial direction. The entire surface of the dividing surface 37c is inclined with respect to the punching direction. The inclination direction is a direction closer to the die part 27 c as it is away from the opening end of the punching hole 20.

Further, as shown in the figure, the dividing surface 37d between the die part 27d and the die part 27a has a corner corresponding to the left end corner of the head 81 in the opening of the punched hole 20 when viewed from above. And consists of a plane in a direction rotated approximately 45 ° to the left from the element axis direction. The entire surface of the dividing surface 37d is inclined with respect to the punching direction. The inclination direction is a direction approaching the die part 27a as the distance from the opening end of the punching hole 20 increases.
Moreover, the point etc. which formed the surface treatment film | membrane in the inner surface of the punching hole 20 are the same as Example 1. FIG.

In the case of this example, the die 27 is provided with four dividing surfaces 37a to 37d and divided in advance into four die parts 27a to 27d. In addition, it is possible to prevent inadvertent cracking of the die at a position corresponding to the vicinity of both corners 825 of the body portion 82.
Therefore, if the die of this example is used, the element can be punched without causing appearance defects, and the life of the die 27 can be improved as compared with the conventional case. Furthermore, the lifetime improvement effect by the surface treatment film | membrane of the inner surface whole surface of the punching hole 20 can also be acquired easily.

(Example 8)
As shown in FIGS. 25 and 26, the die 28 of this example is divided into four die parts 28a to 28f by six dividing surfaces 38a to 38f. These surroundings are constrained by a constraining die 295.
As shown in FIG. 26, the dividing surface 38 a between the die part 28 a and the die part 28 b passes through a corner corresponding to the corner at the right end of the head 81 in the opening of the punched hole 20 when viewed from above, The split surface 38a1 is parallel to the element width direction, the split surface 38a2 is parallel to the element axis direction, and the split surface 38a3 is parallel to the element width direction. The entire surface of the dividing surface 38a1 facing the punching hole 20 is inclined with respect to the punching direction. The inclination direction is a direction approaching the die part 28a as the distance from the opening side of the punching surface 20 increases.

  Further, as shown in the figure, the dividing surface 38b between the die part 28b and the die part 28c is a corner corresponding to the upper right corner of the body 82 in the opening of the punching hole 20 when viewed from above. And only the dividing surface 38a parallel to the element width direction, and the entire surface is inclined with respect to the punching direction. The inclination direction is a direction approaching the die part 28c as the distance from the opening side of the punching surface 20 increases.

  Further, as shown in the figure, the dividing surface 38c between the die part 28c and the die part 28d is a corner corresponding to the corner of the lower right end of the body part 82 in the opening of the punching hole 20 when viewed from above. And a split surface 38c1 parallel to the element axis direction and a split surface 38c2 parallel to the element axis direction are sequentially connected. The entire surface of the dividing surface 38c1 facing the punching hole 20 is inclined with respect to the punching direction. The inclination direction is a direction approaching the die part 28d as the distance from the opening side of the punching surface 20 increases.

  As shown in the figure, the dividing surface 38d between the die part 28d and the die part 28e is a corner corresponding to the corner of the lower left corner of the body 82 in the opening of the punching hole 20 when viewed from above. The dividing surface 38d1 parallel to the element axis direction and the dividing surface 38d2 parallel to the element axis direction are sequentially connected to each other. The entire surface of the dividing surface 38d1 facing the punching hole 20 is inclined with respect to the punching direction. The inclination direction is a direction approaching the die part 28d as the distance from the opening side of the punching surface 20 increases.

  As shown in the figure, the dividing surface 38e between the die part 28e and the die part 28f is a corner corresponding to the upper left corner of the body 82 in the opening of the punched hole 20 when viewed from above. And only the dividing surface 38e parallel to the element width direction, and the entire surface is inclined with respect to the punching direction. The inclination direction is a direction approaching the die part 28e as the distance from the opening side of the punching surface 20 increases.

Further, as shown in the figure, the dividing surface 38f between the die part 28f and the die part 28a has a corner corresponding to the corner of the left end of the head 81 in the opening of the punched hole 20 when viewed from above. As shown in the figure, it is composed of a plane obtained by sequentially connecting a dividing surface 38f1 parallel to the element width direction, a dividing surface 38f2 parallel to the element axis direction, and a dividing surface 38f3 parallel to the element width direction. The entire surface of the dividing surface 38f1 facing the punching hole 20 is inclined with respect to the punching direction. The inclination direction is a direction approaching the die part 28a as the distance from the opening side of the punching surface 20 increases.
Moreover, the point etc. which formed the surface treatment film | membrane in the inner surface of the punching hole 20 are the same as Example 1. FIG.

In the case of this example, the die 28 is provided with six dividing surfaces 38a to 38f and divided into six die parts 28a to 28f in advance. Inadvertent cracks can be prevented in the dies at positions corresponding to the vicinity of the four corners of the body portion 82.
Therefore, if the die of this example is used, the element can be punched without causing any defects in appearance, and the life of the die 28 can be improved as compared with the prior art. Furthermore, the lifetime improvement effect by the surface treatment film | membrane of the inner surface whole surface of the punching hole 20 can also be acquired easily.

DESCRIPTION OF SYMBOLS 1 Punch 2, 22-28 Dies 20 Punching hole 29, 292-295 Restraint type 31-38 Dividing surface 8 Element 81 Head 82 Body part 83 Neck part

Claims (7)

An element for a CVT belt comprising a substantially triangular head, a substantially rectangular trunk, and a neck connecting the central part of the bottom of the head and the central part of the long side of the trunk. A die composed of a die and a punch used for punching from a plate-shaped material,
The punch has an outer shape corresponding to the contour shape of the element, and a punch blade is provided at a corner of the tip.
The die has a punched hole corresponding to the contour shape of the element and is divided into two or more die parts, and the outer peripheral side thereof is restrained by a restraint die.
The dividing surface between the die parts is inclined at a predetermined angle with respect to the punching direction at least in a region larger than the thickness dimension of the element from the opening end of the punching hole. Die for element punching.   2. The die for punching a CVT belt element according to claim 1, wherein the dividing surface is a surface passing through a corner portion corresponding to a corner portion of the element in the punching hole.   3. The CVT belt element according to claim 1, wherein at least one of the divided surfaces includes a surface that passes through at least one of the corners corresponding to the corner of the head in the punched hole. Die for punching.   In any 1 item | term of Claims 1-3, At least 1 of the said division | segmentation surface consists of a surface which passes along at least 1 of the corner | angular part corresponding to the corner | angular part of the said trunk | drum in the said punching hole, It is characterized by the above-mentioned. Die for punching CVT belt elements.   5. The punching process for an element for a CVT belt according to claim 1, wherein a surface treatment film for improving wear resistance is formed on an inner surface of the punching hole of the die. Mold.   6. The die according to claim 1, wherein the outer peripheral side surface of the die and the inner peripheral surface of the constraining die facing the die have a tapered shape that gradually decreases in diameter along the punching direction. A die for punching a CVT belt element.   A punching method for an element for a CVT belt, wherein a plate-shaped material is punched using the mold according to any one of claims 1 to 6.

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