JP4483621B2 - Power transmission chain and manufacturing method thereof - Google Patents

Description

  The present invention relates to a power transmission chain and a manufacturing method thereof.

For example, in a continuously variable transmission (CVT) used in an automobile, a pulley 51 as shown in FIG. The pulley 51 includes a fixed sheave 52 having a conical sheave surface 52a and a movable sheave 53 having a conical sheave surface 53a disposed to face the sheave surface 52a. An endless power transmission chain 56 is wound around a pulley groove formed by the sheaves 52 and 53. The movable sheave 53 is movable in the axial direction by a hydraulic actuator or the like (not shown). By moving the movable sheave 53, the groove width of the pulley groove can be increased or decreased. When the width of the pulley groove is increased or decreased, the power transmission chain 56 moves to the center side of the pulley 51 or is pushed outward while contacting the sheave surfaces 52a and 53a. As a result, the substantial pulley diameter of the pulley 51 is changed so that the gear can be changed steplessly.
The power transmission chain 56 includes a plurality of link plates 54 and a plurality of pins 55 that connect the link plates 54 so as to be bendable to each other. The end surface 55a of the pin 55 is in contact with the sheave surfaces 52a and 53a when the power transmission chain 56 is wound around the pulley 51. The power transmission chain 56 transmits power by frictional force generated by this contact. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 8-31725

When such a power transmission chain 56 is wound around the pulley 51, the pin 55 comes into contact with the sheave surfaces 52a and 53a, so that a contact sound is generated. In order to suppress such contact noise, the end surface 55a of the pin 55 is a convex curved surface set to a predetermined curvature.
However, even if the end surface 55a is a convex curved surface and the contact sound generated from the individual pins 55 is kept relatively small, the pins 55 and the link plate 54 are generally formed in substantially the same shape. The frequency of the contact sound generated when the pin continuously contacts the sheave surface is constant, and noise may occur, such as resonance. For this reason, when quietness is especially required in an automobile or the like, further noise reduction is desired.

  This invention is made | formed in view of such a situation, and it aims at providing the power transmission chain which can suppress generation | occurrence | production of noise effectively, and its manufacturing method.

The present invention comprises a plurality of link plates and a plurality of pins for connecting the link plates to each other, wound around a pulley having a conical sheave surface, and the end surface of the pin and the sheave surface of the pulley In the power transmission chain that contacts and transmits power, the plurality of pins have end surfaces that are formed into convex curved surfaces that have an elliptical contact surface with the sheave surface. All shapes except for the end surface are substantially the same, and the angle of attack with respect to the sheave surface, which is the inclination angle of the major axis of the elliptical contact surface with respect to the chain longitudinal direction when the chain is viewed from the side. this There which consists of two or more pin formed in different two or more kinds of the convex curved surface, these pins, randomly arranged with respect to the longitudinal direction of the power transmission chain It is characterized in.
According to the power transmission chain configured as described above, two or more types of pins having different angles of attack of the end surface with respect to the sheave surface are arranged in the longitudinal direction of the power transmission chain. The frequency of the contact sound generated by the contact between the pin and the sheave surface can be dispersed.

The present invention comprises a plurality of link plates and a plurality of pins for connecting the link plates to each other, wound around a pulley having a conical sheave surface, and the end surface of the pin and the sheave surface of the pulley In the method of manufacturing a power transmission chain that contacts and transmits power, a grinding wheel portion having a grinding surface for grinding the end face of the pin in the vicinity of the outer periphery is set to a central axis parallel to the Z direction with three orthogonal directions as X, Y, and Z. And a carrier for supporting the pin, a predetermined center line in a cross section on the XY plane of the pin, and the center axis and the axis of the pin. By moving the pin and the abrasive surface relative to each other on an XY plane while supporting the pin so that a grinding support angle formed by a reference line of the carrier passing through a predetermined value becomes a predetermined value, pin Contact surface with respect to the sheave surface is formed into a convex curved surface which becomes elliptical by grinding the end faces of the pins by contacting the abrasive surface to rotate the end face, the time of the grinding, to the plurality of pins, The sheave surface which is an inclination angle of the long axis of the elliptical contact surface with respect to the chain longitudinal direction when the chain is viewed from the side by grinding with the grinding support angle set to two or more different values. a pin grinding step angle of attack is formed in different two or more kinds of the convex curved surface with respect to two or more the plurality of pins having different convex surface, respectively, arranged at random with respect to the longitudinal direction of the power transmission chain And an assembly process for assembling the power transmission chain.

  According to the method of manufacturing the power transmission chain configured as described above, by setting the grinding support angle in the pin grinding process to two or more different values, only the shape of the convex curved surface on the end surfaces of the plurality of pins is obtained. Each can be two or more different. That is, the plurality of pins are formed in convex curved surfaces different from each other only in the end surfaces, with all the shapes excluding the end surfaces being substantially the same. Therefore, the power transmission chain can be manufactured by using substantially the same parts other than the pins, such as the link plate and its through-holes. The reason why they are substantially the same is because the existence of a portion irrelevant to the shape of other portions other than the pins and the inevitable dimensional error in manufacturing occur.

In the method for manufacturing a power transmission chain, before the pin grinding step, the pin is parallel to the Z direction, with the three orthogonal directions being X, Y, and Z, and the cross section on the XY plane of the pin is While holding the pin so that the support angle formed by the center line and a line parallel to the X direction and passing through the axis of the pin is the same value as the grinding support angle, It is preferable to have a plane forming step of forming, on the end face of the pin, a plane that is parallel and intersects the X direction and the Z direction at a predetermined angle.
In this case, since the value of the support angle in the plane forming process is set to the same value as the grinding support angle in the pin grinding process, a plane more approximate to the convex curved surface formed by the pin grinding process is obtained. The grinding allowance in the pin grinding process can be reduced. Therefore, the processing time required for the pin grinding process can be shortened and the consumption of the grindstone can be suppressed, and an increase in the manufacturing cost of the power transmission chain can be more effectively suppressed.

According to the power transmission chain of the present invention, two or more types of pins having different angles of attack of the end surface with respect to the sheave surface are randomly arranged in the longitudinal direction of the power transmission chain. The frequency of the contact sound generated by contact with the sheave surface is dispersed, and the generation of noise can be effectively suppressed.
Further, according to the method for manufacturing a power transmission chain of the present invention, the shapes excluding the end faces are made substantially the same for a plurality of pins, and only the end faces are formed on different convex curved surfaces, and these are connected to the power transmission chain. Since it can arrange at random in the longitudinal direction of a chain, the chain which can control generation of noise effectively can be obtained. In addition, since the power transmission chain can be manufactured by using substantially the same parts other than the pins, such as the link plate and its through-holes, the manufacturing is facilitated and the manufacturing cost is reduced. There is no significant increase.

Hereinafter, a power transmission chain and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a perspective view schematically showing a main configuration of a power transmission chain for a continuously variable transmission according to the present embodiment. The power transmission chain 1 (hereinafter, also simply referred to as “chain”) includes a plurality of metal (carbon steel, etc.) link plates 2 and a plurality of metals (bearing steel, etc.) interconnecting the link plates 2. ) Made of pins 3A, 3B and strips 4 slightly shorter than these pins 3A, 3B, which are endless. In FIG. 1, the description of the central portion in the width direction of the chain 1 is partially omitted.

  The link plate 2 has a shape in which the outer contour line is a gentle curve, and is formed so as to have substantially the same outer shape. The link plate 2 includes a first through-hole 2a1 and a second through-hole. A through hole 2a2 is provided. The first through hole 2a1 and the second through hole 2a2 are also collectively referred to as a through hole 2a. The link plates 2 are stacked in the thickness direction as shown in the figure, and the link plates 2 arranged adjacent to each other include the first through hole 2a1 of one link plate 2 and the other link plate 2. The second through-holes 2a2 are superposed so as to be shifted in the longitudinal direction of the chain while being aligned with the positions of the second through holes 2a2, and are arranged in a predetermined order.

The pins 3A and 3B connecting the link plates 2 are rod-shaped bodies having outer peripheral surfaces formed in a predetermined shape, and the shapes of the portions excluding both ends of the pins are formed in substantially the same shape. It is a thing. The strips 4 are rod-like bodies having a substantially elliptical cross section, and are all formed in substantially the same shape. The strip 4 and the pins 3A and 3B are both inserted into the same through hole 2a one by one.
The strip 4 inserted into the first through hole 2a1 is inserted in a fixed state into the first through hole 2a1. The pins 3A and 3B inserted into the first through hole 2a1 can swing by rolling and sliding (rolling contact or sliding contact or contact including both contacts) with respect to the side surface of the fixed strip 4. Has been.
Further, the pins 3A and 3B inserted into the second through hole 2a2 are inserted in a fixed state into the second through hole 2a2. The strip 4 inserted in the second through-hole 2a2 is made swingable by rolling and sliding on the side surfaces of the fixed pins 3A and 3B.
Thus, by inserting one of the strip 4 and the pins 3A and 3B into the through-hole 2a so as to be able to swing, the plurality of link plates 2 arranged in a predetermined order can be bent in the chain longitudinal direction. Yes.

  2A and 2B are views for explaining the shapes of the pins 3A and 3B. FIG. 2A is a partial sectional view in the longitudinal direction of the chain 1, and FIG. 2B is a partial side view in the axial direction of the pins 3A and 3B. . In addition, in (a), the pin and strip currently inserted in the through-hole 2a so that rocking is possible are shown with the dashed-two dotted line. As shown in FIG. 2A, the outer peripheral surfaces of the pins 3A and 3B are sliding surfaces 3A2 and 3B2 for rolling and sliding with the strip 4, and the inner periphery of the through hole 2a when inserted into the through hole 2a. And back surfaces 3A3 and 3B3 for positioning closely with the surface. The sliding surfaces 3A2, 3B2 are formed so as to form an involute curve in a range of a broken line I from the starting point H toward the upper side of the drawing.

  Here, in the cross section of the pins 3A and 3B, when a line passing through the axis K located substantially at the center of the pins 3A and 3B and parallel to the back surfaces 3A3 and 3B3 is defined as a center line T3, the pins 3A and 3B are The second through hole in a state where the center line T3 is inclined by an angle α with respect to a straight line Q parallel to the long axis T4 of the strip 4 having an oval cross section fixed to the first through hole 2a1 and passing through the starting point H. It is fixed to the hole 2a2. An orthogonal line R orthogonal to the long axis T4 and the straight line Q is set substantially parallel to the longitudinal direction of the chain 1.

2B, the end surfaces 3A1 and 3B1 of the pins 3A and 3B come into contact with the sheave surfaces 52a and 53a of the pulley 51 when the chain 1 is wound around the pulley 51. The power is transmitted by the frictional force generated by this contact. The end surfaces 3A1, 3B1 are formed as convex curved surfaces having a predetermined curvature so as to be slightly inclined in accordance with the inclination of the sheave surfaces 52a, 53a so as to be able to smoothly contact the sheave surfaces 52a, 53a.
The pins 3A and 3B are different from each other in the shapes of the end faces 3A1 and 3B1. Hereinafter, differences in the shapes of the end faces 3A1 and 3B1 will be described.

FIG. 3 is a side view of the chain 1 showing contact surfaces of the end surfaces 3A1 and 3B1 of the pins 3A and 3B with respect to the sheave surfaces 52a and 53a. The end surface 3A1 of the pin 3A contacts the sheave surfaces 52a and 53a with the contact surface 5 when the chain 1 is wound around the pulley 51. The end surface 3A1 is formed in a convex curved surface such that the contact surface 5 is elliptical as shown in the figure. The center of the contact surface 5 substantially coincides with the axis K of the pins 3A and 3B, and the major axis T5 of the ellipse is inclined with respect to the straight line Q by an angle α. That is, the long axis T5 coincides with the above-described center line T3.
On the other hand, the end surface 3B1 of the pin 3B is also formed so that the contact surface 6 that contacts the sheave surface is substantially the same elliptical shape as the contact surface 5 like the end surface 3B1. T6 rotates about the axis K by an angle ν with respect to the center line T3, and is inclined with respect to the straight line Q by an angle ξ that is a difference between the angle α and the angle ν. . That is, the convex curved surface of the end surface 3B1 of the pin 3B is formed so that a convex curved surface having substantially the same shape as the convex curved surface of the end surface 3A1 of the pin 3A is rotated about the axis K by an angle ν.

In this way, the end surface 3A1 and the end surface 3B1 are convex so that the major axis of the contact surface when contacting the sheave surfaces 52a and 53a is an angle α and an angle ξ with respect to the straight line Q orthogonal to the chain longitudinal direction, respectively. Since it is formed in a curved surface, when the chain 1 is wound around the pulley 51, it comes into contact with the sheave surfaces 52a and 53a with different angles of attack. Here, the angle of attack is the inclination angle of the long axis of the contact surface with respect to the longitudinal direction of the chain when the chain 1 is viewed from the side, and this angle of attack depends on the contact between the pins 3A and 3B and the sheave surfaces 52a and 53a. It is set to suppress the polygonal operation when the chain 1 is wound around the pulley 51 and bent while suppressing the impact and the contact sound. The pins 3A and the pins 3B having convex curved surfaces having different angles of attack are randomly arranged in the chain longitudinal direction.
The chain 1 configured as described above has two types of pins 3A and 3B having end surfaces that are convex curved surfaces having different angles of attack with respect to the sheave surfaces 52a and 53a, randomly arranged in the longitudinal direction of the chain 1. Therefore, for example, only the pin 3A as a pin having the same angle of attack does not continuously contact the sheave surfaces 52a and 53a for a long time. Therefore, the frequency of the contact sound generated by the contact between the plurality of pins 3A and 3B and the sheave surfaces 52a and 53a can be dispersed, and the generation of noise can be effectively suppressed.

  Next, the manufacturing method of this chain 1 is demonstrated. The chain 1 is assembled as a chain after molding the pin and the link plate, respectively. However, the manufacturing method of the chain 1 according to the embodiment of the present invention has technical characteristics in the processing steps of the pins 3A and 3B. is doing. Below, the manufacturing process of pin 3A, 3B is demonstrated.

  As a material for the pins 3A and 3B, a wire rod such as bearing steel having the same axial cross section as the pins 3A and 3B is used. The pins 3A and 3B are cut into a predetermined dimension, each end face is formed into a predetermined plane (plane forming step), and then the end faces formed on these planes are ground to end faces. A predetermined convex curved surface is formed (pin grinding step), and predetermined heat treatment and polishing are performed to obtain completed pins 3A and 3B.

First, the plane forming process will be described. 4A is an axial side view of the pin 3A after cutting, and FIG. 4B is a cross-sectional view taken along line BB in FIG. In FIG. 4A, the horizontal, vertical, and depth directions orthogonal to each other are defined as an X direction, a Z direction, and a Y direction as illustrated.
The pin 3A is cut from the wire as follows. That is, in the wire rod, the axial direction of the pin 3A is first made parallel to the Z direction by the support U shown in FIG. 4, and the center line T3 and the pin 3A are parallel to the center line T3 as shown in FIG. The support angle formed by the line N passing through the axis K is supported at a predetermined angle. In the case of this pin 3A, this support angle is 0 degree, and the back surface 3A3 is supported so as to be parallel to the XZ plane. At this time, since the back surface 3A3 of the pin 3A is parallel to the center line T3, the support surface U1 of the support U is set at a predetermined angle, and the support surface U1 and the back surface 3A3 are brought into contact with the back surface 3A3 as a reference surface. Thus, the pin 3A can be reliably positioned.

Then, the end face of the pin 3A is formed by cutting the wire with a predetermined dimension by a cutting machine or the like (not shown) having a flat blade for cutting in parallel with the Y direction. At this time, the wire rod is cut such that the end surface 3A1 of the pin 3A intersects the X direction and the Z direction at a predetermined angle as shown in FIG. 4A when viewed from the side in the Y direction. In this way, the cut surface of the pin 3A, that is, the end surface 3A1, is formed in a plane parallel to the Y direction and intersecting the X direction and the Z direction at a predetermined angle.
Further, the end surface 3A1 is cut so as to be symmetrical with respect to the axial center of the pin 3A. At this time, an angle β formed by the cut surface of the pin 3A with respect to the X direction is set to an angle that substantially coincides with the inclined surfaces of the sheave surfaces 52a and 53a (FIG. 2B).

  FIG. 5A is a side view in the axial direction of the pin 3B after cutting, and FIG. 5B is a cross-sectional view taken along the line CC in FIG. The pin 3B is also cut from the material in the same manner as the pin 3A. However, when the pin 3B is cut from the material, the pin 3B is rotated around the axis K so that the support angle becomes an angle ν as a predetermined angle. The end surface 3B1 is formed into a flat surface by being supported and cut.

  As described above, the pins 3A and 3B cut out from the material are formed to have a flat end surface by the plane forming process, but both are supported and processed with different support angles. Therefore, planes having different contour shapes of the cut surfaces are formed.

Next, the pin grinding process will be described. Fig.6 (a) is the side view which showed typically the grinding device used for a pin grinding process. In FIG. 6A, the horizontal, vertical, and depth directions orthogonal to each other are defined as an X direction, a Y direction, and a Z direction, as shown.
The pin grinding step is performed by attaching the pins 3A and 3B having predetermined planes formed on the end surfaces by the plane forming step to the grinding apparatus 30 shown in FIG. The grinding device 30 includes a carrier 31 having a shape in which a plurality of notches are formed at equal intervals on the outer peripheral surface of a disk-shaped member, and is rotatably supported around a central axis 31z parallel to the Z direction, And a grindstone 32 that is a disk-like rotating body supported rotatably around a central axis 32z parallel to the direction. The carrier 31 and the grindstone 32 are each driven to rotate counterclockwise by a motor (not shown).

  The center axis 31z of the carrier 31 and the center axis 32z of the grindstone 32 are on the same center line CL1 in the X direction. FIG. 6B is a horizontal cross-sectional view of the main part including the center line CL1 in FIG. The plurality of cutouts formed on the outer peripheral surface of the carrier 31 are provided with pin holding portions 33 to hold the pins 3A and 3B. Both ends of the pins 3A and 3B held by the pin holding portion 33 protrude from the carrier 31 and are held parallel to the Z direction (center axis 32z).

  In the vicinity of the outer periphery of the grindstone 32, a circumferential groove 32a cut inward from the outer peripheral surface is formed so that the cross-sectional shape is a trapezoid as shown in the figure. Both side walls in the axial direction (Z, -Z direction) of the circumferential groove 32a are abrasive surfaces 32b inclined in a conical shape, and these are symmetrical to each other in the Z direction. In FIG. 6 (b), the inclination angle of the grinding surface 32b and the distance between the grinding surfaces 32b in the Z direction are set so that the end surfaces 3A1, 3B1 of the pins 3A, 3B after grinding become a predetermined convex curved surface. Yes.

  The pin grinding process is performed by rotating the carrier 31 with the grindstone 32 rotating at a constant speed, and passing the pins 3A and 3B between the pair of grinding surfaces 32b. At this time, the rotational speed of the grindstone 32 is set to be relatively high, and the rotational speed of the carrier 31 is set to be lower than the rotational speed of the grindstone 32. When the pins 3A and 3B pass between the pair of grinding surfaces 32b, both end surfaces of the pins 3A and 3B are ground at the same time by the rotating grinding surface 32b to form a convex curved surface having a predetermined curved surface.

Fig.7 (a) is the side view which expanded and showed the pin holding | maintenance part 33 at the time of grinding pin 3A. The pin holding portion 33 is a plate-like surface fixed to a pin holding surface 33a formed parallel to the central axis 31z (the central axis 32z) and a step surface 33b provided with a step with respect to the pin holding surface 33a. Holding member 33c. The pin 3A is positioned by bringing its back surface 3A3 into contact with the pin holding surface 33a, and is held between the pin holding surface 33a and the pressing member 33c and held in parallel in the Z direction.
In this pin grinding process, as shown in the figure, the pin 3A is relative to the reference line M of the carrier 31 passing through the center line T3 of the pin 3A, the center axis 31z (FIG. 6) and the axis K of the pin 3A. The grinding support angle formed in this way is supported at a predetermined angle. In the case of this pin 3A, the center line T3 and the reference line M are set to coincide with each other, and this grinding support angle is 0 degree which is the same value as the support angle in the plane forming step.

  FIG.7 (b) is the side view which expanded and showed the pin holding | maintenance part 33 at the time of grinding the pin 3B. As shown in the drawing, the pin 3B is rotated around the axis K so that the center line T3 of the pin 3B is an angle ν as a predetermined angle with respect to the reference line M of the carrier 31. Supported by the state. This grinding support angle is the same value as the support angle during the flat surface forming process.

  As described above, the pins 3A and 3B whose end surfaces are ground have convex curved surfaces having the same shape formed on the end surfaces 3A1 and 3B1, but are supported and ground so that only the grinding support angles are different. The convex curved surface of the end surface 3B1 of the pin 3B is formed to be a shape obtained by rotating a convex curved surface having substantially the same shape as the convex curved surface of the end surface 3A1 of the pin 3A around the axis K by an angle ν.

  The pins 3A and 3B having the convex curved surfaces formed on the end surfaces 3A1 and 3B1 as described above are inserted into the through holes 2a of the link plate 2 and assembled as the chain 1 after the predetermined heat treatment and polishing process (assembly process). ). In this assembly process, the pins 3 </ b> A and 3 </ b> B are arranged so as to be random in the longitudinal direction of the chain 1.

The chain 1 obtained by such a power transmission chain manufacturing method according to the present embodiment can be a chain that can effectively suppress the generation of noise as described above.
Moreover, according to the method for manufacturing a power transmission chain of the present embodiment, the pins 3A and 3B having different angles of attack with respect to the sheave surface can be obtained by setting the grinding support angles in the pin grinding process to two values. That is, the pins 3A and 3B have substantially the same shape except for the end surfaces, and only the end surfaces are formed in different convex curved surfaces. Accordingly, the chain 1 can be manufactured by using substantially the same parts other than the pins, such as the link plate 2 and the through hole 2a thereof, and the manufacture thereof is facilitated. Furthermore, since the chain 1 can be manufactured without significantly changing other elements such as conventional processing equipment for processing pins, link plates, etc., the manufacturing cost is not greatly increased.
Moreover, since it is not necessary to change the shape of the through-hole 2a etc. of the link plate 2 as mentioned above, the intensity | strength and lifetime as the original chain 1 can be maintained.

Further, according to the present embodiment, since the value of the support angle in the plane forming process is the same value as the value of the grinding support angle in the pin grinding process, the convexity of the pins 3A and 3B formed by the pin grinding process A plane approximate to the curved surface is obtained by this plane forming process, and the grinding allowance in the pin grinding process can be reduced. Therefore, the processing time required for the pin grinding process can be shortened and the consumption of the grindstone can be suppressed, and the increase in the manufacturing cost of the chain 1 can be more effectively suppressed.
Further, according to the present embodiment, if the value of the support angle in the plane forming step and the grinding support angle at the time of the pin grinding step are changed, the shape of the convex curved surface of the pin end surface can be changed to an arbitrary angle of attack, so the angle of attack is Different pins can be easily formed into many types.

In addition, the manufacturing method of the power transmission chain of this invention is not limited to the said embodiment. For example, in the surface grinding process, the plane is formed with the cut surface by the cutting machine, but the pin end surface may be formed into a predetermined plane by forging or the like. Further, in the pin grinding step, the end face of the pin is formed so that the angle of attack is different, but for example, it may be a convex curved surface in which the position of the contact surface on the end face is different.
In this embodiment, two types of pins having different angle of attack at the end face are used. However, pins having various types of angles of attack can also be used.

It is the perspective view which showed typically the principal part structure of the power transmission chain for continuously variable transmission manufactured by this invention. It is a figure for demonstrating the shape of a pin, (a) is a partial cross section figure of a chain longitudinal direction, (b) is a partial side view of the axial direction of a pin. It is the side view of the chain which each showed the contact surface with respect to the sheave surface of end surface 3A1, 3B1 of pin 3A, 3B. (A) is an axial side view of the pin 3A after cutting, and (b) is a cross-sectional view taken along line BB in (a). (A) is an axial side view of the pin 3B after cutting, and (b) is a cross-sectional view taken along the line CC in (a). (A) is the side view which showed typically the grinding device used for a pin grinding process, (b) is a horizontal sectional view of the principal part containing the centerline CL1 in (a). (A) is the pin holding part at the time of grinding pin 3A, (b) is the side view which expanded and showed the pin holding part at the time of grinding pin 3B. It is a figure which shows the power transmission chain wound around the pulley of a continuously variable transmission.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power transmission chain 2 Link plate 3A, 3B Pin 3A1, 3B1 End surface 31 Carrier 32 Grinding stone 32b Grinding surface 51 Pulley 52a, 53a Sheave surface T3 Center line M Reference line

Claims (3)

A plurality of link plates and a plurality of pins for connecting the link plates to each other are wound around a pulley having a conical sheave surface, and the end surface of the pin and the sheave surface of the pulley come into contact with each other to drive power. In the power transmission chain that transmits
The plurality of pins have an end surface formed into a convex curved surface whose contact surface with the sheave surface is elliptical,
Further, the plurality of pins have substantially the same shape except for their end surfaces, and the end surfaces of the pins are inclined with respect to the long axis of the elliptical contact surface with respect to the chain longitudinal direction when the chain is viewed from the side. consists of two or more pins which angle of attack is formed in different two or more kinds of the convex surface with respect to the sheave surfaces at an angle,
A power transmission chain, wherein these pins are randomly arranged in the longitudinal direction of the power transmission chain. A plurality of link plates and a plurality of pins for connecting the link plates to each other are wound around a pulley having a conical sheave surface, and the end surface of the pin and the sheave surface of the pulley come into contact with each other to drive power. In the manufacturing method of the power transmission chain for transmitting
A grindstone having a grinding surface for grinding the end face of the pin in the vicinity of the outer periphery is rotated around a central axis parallel to the Z direction with X, Y, and Z as three orthogonal directions, and a carrier for supporting the pin , A grinding support angle formed by a predetermined center line in a cross section on the XY plane of the pin, which is parallel to the Z-axis direction, and a reference line of the carrier passing through the center axis and the axis of the pin The pin and the abrasive surface are moved relative to each other on the XY plane while supporting the pin so that the value becomes a predetermined value, thereby bringing the end surface of the pin into contact with the rotating abrasive surface. The end surface of the pin is ground to form a convex curved surface in which the contact surface with the sheave surface is elliptical, and the grinding support angle is set to two or more different values for the plurality of pins at the time of grinding. set to be to grinding, the A pin grinding step of angle of attack with respect to the sheave faces is an inclined angle of the major axis of the oval of the contact surface is formed in different two or more kinds of the convex curved surface with respect to the chain longitudinal direction when viewed from the side of En,
An assembly step of assembling the power transmission chain by randomly arranging two or more types of pins each having a different convex curved surface with respect to the longitudinal direction of the power transmission chain;
A method of manufacturing a power transmission chain, comprising:   Before the pin grinding step, the pin is parallel to the Z direction, with the three orthogonal directions being X, Y, and Z, parallel to the center line in the cross section on the XY plane of the pin, and to the X direction. The support angle formed by the line passing through the axis of the pin is the same value as the grinding support angle, while holding the pin, in parallel to the Y direction and in the X direction and the Z direction. 3. The method of manufacturing a power transmission chain according to claim 2, further comprising a plane forming step of forming a plane intersecting at a predetermined angle on the end surface of the pin.

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