JP2005308108A - Method of manufacturing load pin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a load pin by which a load pin having an end surface which is formed to curve in both directions perpendicular to each other on the same plane can be manufactured at a high precision and at a high efficiency. <P>SOLUTION: In the method of manufacturing the load pin 1 which connects a plurality of link plates 52 provided to a driving power transmitting chain C to each other, a curved surface 6 which is curved in both directions 2, 3 perpendicular to each other on the same plane is formed on the end surface 1a of the load pin 1 to be processed by attaching each load pin 1 to a rotation fixture 10 such that the end surface 1a to be processed is oriented outside of the rotation fixture 10 to cause the load pin 1 to rotate, by rotating a cup type grinding stone 23 having an approximately conical-shaped grinding surface 23a with a diameter gradually increased towards the rotation fixture 10, and then by pressing the end surface 1a of the load pin 1 to be processed against the grinding surface 23a at a given angle. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a load pin for connecting a link plate provided in a power transmission chain, and more particularly to a method for manufacturing a load pin provided in a power transmission chain used in a continuously variable transmission.

For example, a conical pulley type transmission capable of adjusting a gear ratio steplessly applied to a continuously variable transmission (CVT) used in an automobile has a gear ratio adjusted on a pair of drive shafts and a sliding surface on the inside. Is arranged. Each of the conical pulleys is fixed in a relatively non-rotatable manner to form a pair, and a metal power transmission chain, for example, circulates between the pair of conical pulleys. In this power transmission chain, a group of link plates made up of a plurality of link plates is coupled to bend freely by load pins.
The load pin circulates between the pulleys with the shaft centered toward the drive shaft. When the load pin enters or exits between the pulleys, the end surface of the load pin contacts the inner surface of the pulley. As a result, sound is generated or wear of the end surface occurs. In order to suppress the occurrence of such wear, a load pin having a curved end surface is disclosed (see Patent Document 1).
Japanese Utility Model Publication No. 3-84459 (FIG. 2)

  The end surface of the load pin described in Patent Document 1 is on the same plane so as to swell in each of the circulation direction of the power transmission chain (diameter direction of the pulley) and the direction orthogonal to the circulation direction (circumferential direction of the pulley). Thus, a curved surface that is curved in either of two directions orthogonal to each other is formed. In order to form such a curved surface, a curved surface that swells in one direction must first be formed, and then another curved surface that swells in the other direction must be formed, and the machining operation has to be repeated twice. In this case, since the operation of aligning the position of the load pin with the fixing jig has to be performed twice, the operation becomes complicated and takes a long time. Further, the processing accuracy of the curved surface was low due to the displacement of the load pin. Therefore, the machining operation for forming the curved surface on the end face of the load pin cannot be performed with high accuracy in a short time.

  In view of such a conventional problem, the present invention is to accurately and efficiently manufacture a load pin having curved end surfaces that are curved in both directions orthogonal to each other on the same plane. Objective.

In order to achieve the above object, the present invention takes the following technical means.
That is, the first aspect of the present invention is a load pin manufacturing method for connecting a large number of link plates provided in a power transmission chain to each other, and each load pin is attached to a rotating jig with its processing end face facing outward. By attaching and turning, rotating a cup-type grindstone having a substantially conical grinding surface gradually expanding toward the rotating jig side, and pressing the processing end surface of the load pin on the grinding surface at a predetermined angle A curved surface that is curved in either of two directions orthogonal to each other on the same plane is formed on the processed end surface of the load pin.
In this case, the processing end face of each load pin is continuously pressed against the substantially conical grinding surface gradually expanding toward the rotating jig side while turning around the axis of the rotating jig. Then, curved surfaces that are curved in both directions perpendicular to each other on the same plane are formed one after another on the processed end surface. Therefore, a large number of load pins having the curved surface formed on the end face can be manufactured by a single processing operation. As a result, the machining operation can be performed in a short time, and the machining accuracy is further improved.

  In the first aspect of the present invention, the distance from the axis of the cup-type grindstone to the grinding surface is the dimension of one of the two radii of curvature in the two directions, and from the axis of the rotating jig to the grinding wheel. By setting the distance to the surface to be the dimension of the other curvature radius, the curvature radius of the curved surface can be easily set only by changing the positions of the axes of the grinding surface and the rotating jig.

A second aspect of the present invention is a method for manufacturing a load pin for connecting a plurality of link plates provided in a power transmission chain to each other, wherein each load pin is attached to a rotating jig with its processing end face facing outward. By rotating a disk-type grindstone having a curved grinding surface at the outer periphery and pressing the processing end surface of the load pin at a predetermined angle against the grinding surface, either of two directions orthogonal to each other on the same plane Also, a curved surface that is curved is formed on the processed end surface of the load pin.
In this case, the processing end surface of each load pin is continuously pressed against the curved grinding surface while turning around the axis of the rotating jig, so that the processing end surface is in two directions orthogonal to each other on the same plane. Both curved surfaces are formed one after another. Therefore, a large number of load pins having the curved surface formed on the end face can be manufactured by a single processing operation. Thereby, the said processing operation can be performed in a short time and processing precision improves.

  In the second aspect of the present invention, the radius of curvature of the grinding surface is one of the two directions, and the distance from the axis of the rotating jig to the grinding surface is the dimension of the other radius of curvature. Thus, the curvature radius of the curved surface can be easily set only by changing the curvature radius of the grinding surface and the position of the axis of the rotary jig.

  As described above, according to the present invention, the processing end surface of the rotating load pin is pressed against the substantially conical grinding surface provided on the cup-type grinding wheel or the curved grinding surface provided on the outer peripheral edge of the disc-type grinding stone. By doing so, it is possible to manufacture with high accuracy and high efficiency a load pin in which curved surfaces that are curved in both directions orthogonal to each other on the same plane are formed on the end surface.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In FIG. 1, a drive shaft 50 is provided in a conical pulley type transmission P that can be steplessly adjusted in a gear ratio, which is applied to a continuously variable transmission (CVT) of an automobile. A gear ratio is provided on the drive shaft 50. A pair of left and right conical pulleys (sheaves) 51, 51 having a sliding surface 51a on the inside are arranged. These pulleys 51 are fixed so that they cannot rotate relative to each other. When one of the pulleys 51 is moved in the axial direction by the operation of a hydraulic actuator or the like, the effective diameter of the pulley 51 is changed and the gear ratio is continuously changed between the input and output shafts. It can be changed to.

  A metal power transmission chain C (hereinafter referred to as a chain) circulates between the pulleys 51 and 51. In the chain C, a group of link plates made up of a plurality of link plates 52 is coupled by a load pin 1 so as to be refractable. That is, the link plate 52 in the chain C is arranged in parallel at a predetermined pitch along the longitudinal direction of the chain C, and the load pin 1 is inserted into an insertion hole (not shown) provided in the link plate 52, whereby the chain longitudinal direction. It is connected to the endless and bendable.

Further, both end surfaces 1 a of the load pin 1 are in contact with the sliding surface 51 a of the pulley 51. That is, when the chain C passes between the pair of left and right pulleys 51, the chain C circulates while the both end surfaces 1a are in contact with the sliding surface 51a. The present invention particularly relates to grinding of the end face 1a of the load pin 1 provided in the chain C used in the CVT.
FIGS. 2A and 2B show an embodiment of a method for manufacturing the load pin 1 according to the first aspect of the present invention. In the present embodiment, the processed end surface 1a is ground by the surface grinder 20 and the rotating jig 10 so as to perform curved surface processing on the end surface 1a (hereinafter referred to as a processed end surface) of the load pin. The load pin 1 to be ground has a rectangular cross section instead of a round bar as shown in FIG. On the right side of FIG. 2A, there is installed a rotating jig 10 that is rotatably fixed by a drive system (not shown) with the first axis 11 as an axis, and around the rotating jig 10 is a load pin 1. The attachment part 12 which attaches is provided.

  The mounting portion 12 is a pocket having a rectangular cross section that enters obliquely downward in the center direction from the upper part of FIG. 2A of the peripheral surface 10a, and has a depth to which the load pin 1 can be mounted. A large number of mounting portions 12 are provided radially on the peripheral surface 10 a of the rotating jig 10 with the first axis 11 as the center. Further, the distance from the first axis 11 to the approximate center of the radial width of the abrasive surface 23a (described later) (that is, the distance from the first axis 11 to the machining end surface 1a) is set to R1. As shown in FIG. 2B, a large number of load pins 1 to be ground are attached to the respective attachment portions 12 and are arranged radially around the rotating jig 10. Each load pin 1 is tilted upward in the figure, and the vicinity of the processed end face 1a is exposed to the outside of the rotating jig 10. Accordingly, the load pin 1 is disposed with the machining end face 1 a facing the cylindrical grinding machine 20 outside the rotating jig 10, and is turned around the first axis 11. The mounting angle of the load pin 1 is not limited to the angle shown in the figure, and the axis of the load pin 1 may be horizontal in the figure.

2A and 2B, a surface grinding machine 20 is disposed on the left side of the rotating jig 10. The surface grinding machine 20 is fixed rotatably by a drive system (not shown) with a second axis 21 orthogonal to the first axis 11 as an axis. Further, the surface grinding machine 20 includes a rotating plate 22 and a cup-type grindstone 23 fixed to the rotating plate 22. Accordingly, the cup-type grindstone 23 rotates about the second axis 21 as the rotation plate 22 rotates.
The cup-type grindstone 23 has a cylindrical shape, and is provided with a conical grinding surface 23a oriented in one direction (the direction of the rotating jig). The grinding surface 23a has a substantially conical shape that gradually increases in diameter toward the rotating jig 10 as shown in the figure. In this embodiment, the widthwise cross section of the grinding surface 23a is linear. It may be slightly curved so that the inside is recessed. Accordingly, the grinding surface 23a rotates around the second axis 21. In the present embodiment, the distance (the grinding surface 23a diameter) from the approximate center of the radial width of the grinding surface 23a to the second axis 21 is R2. When the distance R2 from the inner edge of the grinding surface 23a to the second axis 21 is changed, it may be replaced with a cup-type grinding stone 23 having a grinding surface diameter different from this, and for example, the width of the grinding surface 23a is increased. You may make it change the position of the process end surface 1a pressed on this grinding surface in the up-down direction of Fig.2 (a).

Further, the surface grinding machine 20 is rotated with respect to the surface grinder 20 so that the grinding surface 23a of the cup-type grindstone 23 and the processing end surface 1a of the load pin 1 attached to the rotating jig 10 are aligned in the vertical direction in FIG. The tool 10 is positioned.
2 (a) and 2 (b), the rotary jig 10 and the surface grinding machine 20 are driven to turn the load pin 1 around the first axis 11 and rotate the grinding surface 23a. On the other hand, the processing end surface 1a of the load pin 1 (or the polishing surface 23a against the processing end surface 1a of the load pin 1) is successively pressed against the grinding surface 23a to perform grinding.

  As shown in FIGS. 3A to 3C, the processed end surface of the ground load pin 1 is formed into a curved surface that is curved in both directions orthogonal to each other on the same plane. That is, the machining end surface 1a is ground as a curved surface curved in both the radial direction 2 of the pulley 51 (the longitudinal direction of the load pin end surface 1a) on which the chain C is hung and the circumferential direction 3 of the pulley 51. As shown in FIG. 3C, a curved line 4 swells on the machining end face 1a with a radius of curvature R1, and a curved line 5 swells with a radius of curvature of R2 as shown in FIG. 3B in a direction orthogonal to the curved line 4. Is formed. Therefore, the distance R2 from the second axis 21 of the cup-type grindstone 20 to the grinding surface 23a is the dimension of the radius of curvature of one of the two directions, and the grinding surface from the first axis 11 of the rotating jig 10 The distance R1 to 23a is the dimension of the other radius of curvature.

  Therefore, according to this method, the curvature radius of the processing end surface 1a of the load pin 1 can be easily changed only by changing the positions of the grinding surface 23a and the first axis 11 of the rotating jig 10. Thus, according to the manufacturing method of the load pin 1 of this embodiment, while the process end surface 1a of each load pin 1 turns around the 1st axis 11 of the rotation jig 10, toward the rotation jig 10 side. A curved surface 6 that is curved in both the two directions 2 and 3 orthogonal to each other on the same plane on the processing end surface 1a by being continuously pressed to the substantially conical grinding surface 23a that gradually increases in diameter. Are formed one after another. Accordingly, a large number of load pins 1 having the curved surface 6 formed on the end surface 1a can be manufactured in one machining operation, and the machining operation is shortened. In addition, machining accuracy is improved because only one machining operation is required.

  Up to now, when the curved surface 6 is formed on the end surface of the load pin, a curved surface that swells in one direction must be formed first, and then a curved surface that swells in the other direction must be formed, and the machining operation needs to be repeated twice. In addition, the machining operation for forming the curved surface could not be accurately performed in a short time. Since the present invention does not require the load pin 1 to be processed twice, it has high processing accuracy and high efficiency, and is particularly suitable for a chain used in CVT. Moreover, the radii of curvature R1 and R2 of the machining end surface 1a can be easily changed by setting the positions of the grinding surface 23a and the first axis 11 of the rotating jig 10. In the present embodiment, the case where the first axis 11 and the second axis 21 are orthogonally arranged is shown, but the first and second axes 11 and 21 are configured to form other angles. May be.

  4 (a) and 4 (b) show an embodiment of a method for manufacturing a load pin 1 according to the second aspect of the present invention. In the present embodiment, similarly to the embodiment according to the first invention, the processing end surface 1a of the load pin 1 is subjected to curved surface processing. In the present embodiment, the processed end face 1a is ground by the cylindrical grinder 30 and the rotating jig 10. The load pin 1 to be ground has a rectangular cross section instead of a round bar as shown in FIG. On the right side of FIG. 4A, there is provided a rotating jig 10 that is rotatably fixed by a drive system (not shown) with the first axis 11 as an axis, and around the rotating jig 10 is a load pin 1. The attachment part 12 which attaches is provided. The mounting portion 12 is a pocket having a rectangular cross section that enters from the central portion of the rotating jig peripheral surface 10a in FIG. Has a depth of about. A large number of mounting portions 12 are provided radially on the peripheral surface 10 a of the rotating jig 10 around the first axis 11.

  Further, as shown in FIG. 4B, a large number of load pins 1 to be ground are attached to the respective attachment portions 12 and are arranged radially around the rotating jig 10. Each load pin 1 is attached in a state where it is leveled in the drawing and the vicinity of the processed end face 1a is exposed to the outside of the rotating jig 10. The load pin 1 has a machining end face 1 a disposed outside the rotating jig 10 and is turned around the first axis 11.

  4 (a) and 4 (b), a cylindrical grinder 30 as a disc-type grindstone is arranged on the left side of the rotating jig 10. In FIG. The cylindrical grinding machine 40 is rotatably fixed by a drive system (not shown) with a second axis 31 parallel to the first axis 11 as an axis. The cylindrical grinding machine 30 has a disk shape having a required thickness, and an outer edge portion is provided with a concave grinding surface 30a facing outward in the radial direction. Accordingly, when the cylindrical grinding machine 30 rotates, the grinding surface 30a rotates around the second axis 31. The grinding surface 30 a is formed as a curved surface that is recessed with a radius of curvature of R 2, and is directed to the peripheral surface 10 a of the rotating jig 10.

Further, the grinding surface 30a of the cylindrical grinding machine 30 and the processing end face 1a of the load pin 1 attached to the rotating jig 10 are rotated with respect to the cylindrical grinding machine 30 so that their positions are aligned in the vertical direction in FIG. The jig 10 is positioned. In this embodiment, the distance from the first axis 11 to the grinding surface 30a or the machining end surface 1a is set to be R1.
4 (a) and 4 (b), the rotary jig 10 and the cylindrical grinding machine 30 are driven to turn the load pin 1 and rotate the grinding surface 30a. Grinding is performed by successively pressing the processing end surface 1a of the load pin 1 (or the abrasive surface 30a against the processing end surface 1a of the load pin 1).

  The processed end surface 1a of the ground load pin 1 is formed into a curved surface that is curved in both directions perpendicular to each other on the same plane, as shown in FIGS. That is, the machining end surface 1a is ground as a curved surface curved in both the radial direction 2 of the pulley 51 (the longitudinal direction of the load pin end surface 1a) on which the chain C is hung and the circumferential direction 3 of the pulley 51. As shown in FIG. 3 (c), the processing end face 1a swells with a radius of curvature R1, and in a direction orthogonal to the curve 4, swells with a radius of curvature of R2 as shown in FIG. 3 (b). A curved surface 6 having a curved line 5 is formed, the radius of curvature R2 of the grinding surface 30a is set to one of the two directions, and from the first axis 11 of the rotating jig 10 to the grinding surface 30a. Is the dimension of the other radius of curvature.

  Therefore, according to this method, the curvature radius of the curved surface 6 can be easily changed only by changing the curvature radius R2 of the grinding surface 30a and the position of the first axis 11 of the rotating jig 10. Thus, according to the manufacturing method of the load pin 1 of this embodiment, the processing end surface 1a of each load pin 1 continues to the curved grinding surface 30a one after another while turning around the first axis 11 of the rotating jig 10. By being pressed, curved surfaces 6 that are curved in both two directions 2 and 3 that are orthogonal to each other on the same plane are formed one after another on the processed end surface 1a. Accordingly, it is possible to manufacture a large number of load pins 1 having the curved surface 6 formed on the end surface 1a in one processing operation, and it is not necessary to repeat the processing operation of the load pin 1 twice. It is efficient, especially for chains used in CVT. In addition, the radii of curvature R1 and R2 of the machining end surface 1a can be easily changed simply by setting the positions of the grinding surface 30a and the first axis 11 of the rotating jig 10. In the present embodiment, the first axial center 11 and the second axial center 31 are arranged in parallel. However, the first and second axial centers 11 and 31 are configured to form other angles. May be.

The above-described embodiments according to the first and second aspects of the present invention are illustrative and not restrictive. For example, when the shape of the processed end face 1a of the load pin 1 is formed as a tapered surface as shown in FIG. 5A and a curved surface having a radius of curvature of R2 is formed at the tip, the second invention according to the second aspect of the present invention is concerned. In the embodiment, the abrasive surface 30a may be formed in a shape that matches the shape. Further, as shown in FIG. 5 (b), even when the contact portion is flat and has the shape of R2 on both sides, in the same embodiment, the grinding surface 30a can be formed to match the shape. That's fine.
Furthermore, in the same embodiment, the grinding surface 30a is applied to the ground surface 30a in the arrow portion 7 shown in FIG. 5C. What is necessary is just to form in the shape which suits a shape. Thus, the shape of the processing end surface 1a can be changed by changing the shape of the grinding surface 30a.

  In addition, the shape and specifications of the rotary jig 10, the surface grinder 20, and the cylindrical grinder 30 are appropriately changed at the manufacturing site, and their rotational speed is a speed at which the machining end face 1a is accurate. Is selected. The material of the grinding surfaces 23a, 30a may be selected in accordance with the material, processing accuracy, processing speed, etc. of the load pin 1. The cross-sectional shape of the load pin 1 is appropriately changed according to the design specification of the chain C.

It is a partially broken side view in which the power transmission chain is attached to the pulley of CVT. (A) is sectional drawing which shows the manufacturing method of the load pin in 1st this invention, (b) is the top view which looked at (a) from the top. (A) is a perspective view after the processed end surface of the load pin has been processed, and (b) is a top view of the state in which the processed load pin end surface is in contact with the sliding surface of the pulley. (C) is the figure which looked at the state in which the processed load pin end surface is contacting the sliding surface of a pulley from the side. (A) is sectional drawing which shows the manufacturing method of the load pin in 2nd this invention, (b) is the top view which looked at (a) from the top. (A), (b), (c) is the figure which looked at the state which the load pin processed by other embodiment is contacting the sliding surface of a pulley from the top.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Load pin 1a Machining end surface 6 Curved surface 10 Rotating jig 11 1st axis 20 Surface grinder 21 2nd axis 23a Abrasive surface 30 Cylindrical grinder 30a Abrasive surface 31 2nd axis

Claims (4)

A method of manufacturing a load pin for connecting a plurality of link plates provided in a power transmission chain to each other,
Each load pin is attached to a rotating jig with its processing end face facing outward and swiveled, and a cup-type grindstone having a substantially conical grinding surface gradually expanding toward the rotating jig side is rotated. The processing end surface of the load pin is pressed at a predetermined angle against the grinding surface to form a curved surface curved in both directions orthogonal to each other on the same plane on the processing end surface of the load pin. A method for manufacturing a load pin.   The distance from the axis of the cup-type grindstone to the grinding surface is the size of one of the two radii of curvature, and the distance from the axis of the rotating jig to the grinding surface is the other radius of curvature. The method for manufacturing a load pin according to claim 1, wherein the dimensions are as follows. A method of manufacturing a load pin for connecting a plurality of link plates provided in a power transmission chain to each other,
Each load pin is attached to a rotating jig with its processing end face facing outward and swiveled, and a disk-type grindstone having a curved grinding surface on its outer peripheral edge is rotated, and the processing end face of the load pin is placed on the grinding surface. A method of manufacturing a load pin, wherein a curved surface that is curved in either of two directions perpendicular to each other on the same plane is formed on the processed end surface of the load pin by pressing at a predetermined angle.   The radius of curvature of the grinding surface is one of the two directions, and the distance from the axis of the rotating jig to the grinding surface is the dimension of the other curvature radius. Load pin manufacturing method.

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