JP2007092914A - Power transmission chain and power transmission device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission chain capable of making hardly bringing about fatigue of a link due to stress and amplitude of stress and preventing shortening of service life of the chain caused by the fatigue and to provide a power transmission device using the chain. <P>SOLUTION: This power transmission chain 1 is provided with a plurality of links 2 and a plurality of pin members 3. The link 2 has a stress releasing hole 5 for reducing stress generated by force received from the pin member 3 in the vicinity of a corner part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power transmission chain used in a chain type continuously variable transmission employed in a vehicle or the like, and a power transmission device using the same.

As a continuously variable transmission (CVT) for an automobile, for example, a drive pulley provided on the engine side, a driven pulley provided on the drive wheel side, an endless power transmission chain spanned between both pulleys, There is something with. Of these, the power transmission chain is configured by being inserted into a through-hole provided in the link, and the conical sheave surface of the pulleys and the end surface of the pin member of the chain are the circumference of the sheave surface. Traction is generated by making a slight sliding contact in the direction, and power is transmitted by this traction. Among such power transmission chains, for example, in Patent Document 1, in order to reduce the tensile stress generated at the edge portion of the through hole of the link, a notch is provided at the edge portion of the through hole and the same edge portion is obtained by prestress. It has been proposed that a residual compressive stress be generated.
JP 2000-266132 A

In the link that enters and exits the pulley, stress and stress amplitude generated by the force received from the pin inserted through the through hole are generated. However, in the link of the chain of Patent Document 1, the residual compressive stress due to the notch only cancels a part of the stress generated in the link. Therefore, just using such a link cannot sufficiently suppress the fatigue of the link due to the rotational movement of the power transmission chain, which adversely affects the chain life.
The present invention has been made in view of such circumstances, and makes it difficult for the link to be fatigued due to the stress generated by the force received from the pin and the stress amplitude, thereby preventing the chain life from being reduced due to the fatigue. An object of the present invention is to provide a transmission chain and a power transmission device using the same.

In order to achieve the above object, the present invention takes the following technical means.
That is, the present invention includes a plurality of substantially rectangular links having through holes and a plurality of pin members that are inserted through the through holes and connect the plurality of links to each other, A first pulley having a conical surface and a second pulley having a conical surface, and an annular ring that transmits power in contact with the sheave surfaces of the first and second pulleys. In the power transmission chain, the link has a stress relaxation hole in the vicinity of a corner for relaxing a stress generated by a force received from the pin member.

  According to the power transmission chain of the present invention, stress generated in the link when the chain enters and exits the pulley can be suppressed by the stress relaxation hole. Further, the stress amplitude generated in the link by the stress relaxation hole can be reduced. As a result, the fatigue of the link due to the rotational motion of the chain is less likely to occur, so that it is possible to prevent a reduction in chain life due to the fatigue.

In the present invention, it is preferable that the stress relaxation hole is provided in the vicinity of an inner peripheral side corner of at least a front portion in the chain traveling direction of the link.
In the link during the rotation operation of the power transmission chain, particularly large stress is generated in the vicinity of the inner peripheral side corner of the front part in the chain traveling direction. Therefore, the generation of stress can be effectively suppressed by providing the stress relaxation hole in such a portion.

  Further, in the power transmission chain, the plurality of pin members may be inserted into the through holes in a press-fitted state, and even in this case, the stress generated in the link by the stress relaxation holes can be suppressed, and the stress amplitude is also reduced. can do.

  The present invention also spans between a first pulley having a conical sheave surface, a second pulley having a conical sheave surface, and the first and second pulleys. A power transmission device that is in contact with the sheave surfaces of the first and second pulleys and transmits power between both pulleys by frictional force, wherein the power transmission chain is the power transmission chain described above. It is characterized by being.

  According to the power transmission device of the present invention, the link of the power transmission chain has the stress relaxation hole, and the deterioration of the chain life due to the fatigue of the link is prevented. It can be set as the power transmission device which can perform power transmission.

  According to the present invention, a stress relaxation hole is provided in the link to make it difficult for the link to be fatigued due to internal stress or stress amplitude. Therefore, a power transmission chain in which a reduction in chain life due to the fatigue is prevented can be obtained. it can. Moreover, since the power transmission device of the present invention uses the chain as described above, power transmission can be performed stably over a long period of time.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing a main configuration of an embodiment of a power transmission chain (hereinafter simply referred to as “chain”) according to the present invention. The chain 1 according to the present embodiment is endless, and includes a plurality of metal (bearing steel, etc.) links 2 and a metal (bearing steel, etc.) as a plurality of pin members for connecting the links 2 to each other. A pin member 3 (also referred to as a first pin) and a strip 4 (also referred to as a second pin or an interpiece) slightly shorter than these pin members 3 are also used as pin members. Such a chain 1 according to the present embodiment is used for a power transmission device, spanned between two pulleys of the power transmission device, and an end surface of the pin member 3 and a sheave surface of both pulleys. The power is transmitted by the contact.

  The link 2 has a substantially rectangular shape whose outer contour line is a gentle curve, and is provided with two first and second through holes 2a and 2b per sheet so that all have substantially the same outer shape. Is formed. The substantially rectangular shape in the present invention includes a shape close to a rectangle to a shape close to an ellipse (a shape in which a corner can be conceived). The first and second through holes 2a and 2b are formed so that the pin member 3 and the strip 4 can be press-fitted. Such links 2 are connected so as to be bent in the longitudinal direction (power transmission direction) of the chain 1 while being arranged in a predetermined order parallel to the width direction of the chain 1.

  The pin member 3 inserted into the first through hole 2a is a rod-shaped body having an end surface that comes into contact with the sheave surface of the pulley, and the first through holes 2a of the plurality of links 2 arranged in the width direction of the chain 1. In the press-fitted state, the link 2 is connected. The pin member 3 inserted into the second through-hole 2b is loosely fitted to the second through-hole 2b so as to be rotatable (the first through of other links arranged shifted in the chain longitudinal direction). Press fit into the hole).

  The strip 4 is a rod-like body formed slightly shorter than the pin member 3 so as not to contact the sheave surface (the strip 4 of the second through-hole 2b is press-fitted, and the strip 4 of the first through-hole 2a is loose. Fitted). And this strip 4 is inserted in the 1st, 2nd through-holes 2a and 2b so that the one side surface may contact one side surface of the pin member 3. FIG. As a result, the links 2 arranged so as to be displaced in the longitudinal direction are connected to be bendable. Further, the pin member 3 hardly rotates with respect to the sheave surface of the pulley. For this reason, friction loss is reduced and high power transmission efficiency can be ensured.

  As shown in FIGS. 1 and 2, the link 2 is provided with a stress relaxation hole 5 penetrating the front and back for relaxing the stress generated by the force received from the pin member 3 or the strip 4 near the corner of the substantially rectangular shape. It has been. When the chain 1 rotates between the pulleys, a particularly large force acts on the edge corner a1 of the through hole 2a to which the pin member 3 contacts and the other edge corner a2 of the through hole 2a to which the strip 4 contacts. The link 2 of this embodiment has the stress relaxation holes 5 at the four corners where such a force acts, thereby effectively reducing the tensile stress, compressive stress, or stress amplitude generated at the four corners. can do. In addition, the stress relaxation hole 5 is formed as a crescent-shaped long hole whose center portion swells outward slightly in accordance with the shape of the corner of the link 2, so that each stress can be reduced more effectively. Yes.

According to the chain 1 of the present embodiment, since the link 2 has the stress relaxation holes 5 near the corners of the substantially rectangular shape, the stress and the stress amplitude generated in the link 2 due to the rotational movement of the chain 1 are effective. Can be reduced. Thereby, since the fatigue of the link 2 due to the rotational movement of the chain 1 is less likely to occur, it is possible to prevent the chain life from being reduced due to the fatigue.
In this embodiment, the stress relaxation holes 5 are provided at the four corners of the link. However, the number and location of the stress relaxation holes are not limited, and the stress generated in the link is reduced according to the chain or link shape. What is necessary is just to provide a stress relaxation hole in a desired corner vicinity position. For example, the stress generated in the link 2 when the chain 1 enters the pulley is particularly large on the inner peripheral side 2A of the front part in the chain traveling direction X of the link 2 among the four corners. The stress relaxation hole 5 may be provided. In addition, the shape of the stress relaxation hole is not limited. For example, the shape of the stress relaxation hole of the present embodiment may be further extended in the longitudinal direction and curved, or may be a circular shape or a rectangular shape. Good.

  In addition, although it showed about the pin member which consists of a pin and a strip, you may comprise a pin member by the 1st, 2nd two pins, or only one pin. When using two pins, only one or both may contact the sheave surface. Further, the pin may be fixed to the link by another fixing member in addition to the press-fitting of the link hole edge. In the case of press fitting, the stress at the link corner increases, and the stress relaxation according to the present invention is particularly effective.

  FIG. 3 and FIG. 4 are schematic perspective views showing the main configuration of a chain type continuously variable transmission (hereinafter also simply referred to as “continuously variable transmission”) according to an embodiment of the power transmission device of the present invention. is there. The continuously variable transmission according to the present embodiment is mounted on, for example, an automobile, and is made of a metal (structural steel, etc.) drive pulley 10 as a first pulley and a metal (structural steel, etc.) as a second pulley. A driven pulley 20 and the above-described chain 1 spanned therebetween are provided. The chain 1 in FIG. 3 shows a partial cross-section for easy understanding.

  The drive pulley 10 is attached to an input shaft 11 connected to the engine side so as to be integrally rotatable, and is disposed so as to face the fixed sheave 12 having a conical inclined surface 12a and the inclined surface 12a. And a movable sheave 13 having a conical inclined surface 13a. The inclined surfaces 12a and 13a of these sheaves form a V-shaped groove, and the chain 1 is sandwiched and held by the groove with a strong pressure. In addition, a hydraulic actuator (not shown) for changing the groove width is connected to the movable sheave 13, and the groove width is changed by moving the movable sheave 13 at the time of shifting, thereby moving the chain 1. Thus, the winding radius of the chain 1 with respect to the input shaft 11 can be changed.

  On the other hand, the driven pulley 20 is attached to an output shaft 21 connected to the drive wheel side so as to be integrally rotatable and has an inclined surface for forming a groove for sandwiching the chain 1 with high pressure, like the drive pulley 10. A fixed sheave 22 and a movable sheave 23 are provided. Further, a hydraulic actuator (not shown) is connected to the movable sheave 23 of the pulley 20 in the same manner as the movable sheave 13 of the drive pulley 10, and the groove width is determined by moving the movable sheave 13 during shifting. Thus, the chain 1 is moved so that the winding radius of the chain 1 with respect to the output shaft 21 can be changed.

  Since the details of the chain 1 spanned between the drive pulley 10 and the driven pulley 20 are as described above, the description thereof is omitted. In the continuously variable transmission according to the present embodiment configured as described above, a continuously variable transmission can be performed as follows. That is, when the rotation of the output shaft 21 is decelerated, the groove width on the drive pulley 10 side is enlarged by the movement of the movable sheave 13, and the pin member end surfaces 3a, 3b of the chain 1 are inside the conical sheave surfaces 12a, 13a. The diameter of the chain 1 wound around the input shaft 11 while making sliding contact under boundary lubrication conditions (a lubrication state in which part of the contact surface is in direct contact with the microprojections and the remaining part is in contact with the lubricating oil film) On the other hand, on the driven pulley 20 side, the groove width is reduced by the movement of the movable sheave 23, and the pin member end faces 3a, 3b of the chain 1 are directed toward the outer side of the conical surface of the sheave faces 22a, 23a. The winding diameter of the chain 1 with respect to the output shaft 21 is increased while making sliding contact underneath.

  By doing so, the rotation of the output shaft 21 can be decelerated. On the other hand, when the rotation speed of the output shaft 21 is increased, the groove width on the drive pulley 10 side is reduced by the movement of the movable sheave 13, and the pin member end faces 3a, 3b of the chain 1 are formed on the conical sheave faces 12a, 13a. While the sliding diameter of the chain 1 on the input shaft 11 is increased in a sliding contact toward the outer side, the groove width is increased by the movement of the movable sheave 23 on the driven pulley 20 side, and the pin of the chain 1 is increased. While the member end surfaces 3a and 3b are in sliding contact with each other toward the inner side of the conical sheave surfaces 22a and 23a under boundary lubrication conditions, the winding diameter of the chain 1 around the output shaft 21 is reduced. By doing so, the rotation of the output shaft 21 can be increased.

In the continuously variable transmission according to the present embodiment configured as described above, the link 2 of the chain 1 has the stress relaxation hole 5, and shortening of the chain life due to fatigue of the link 2 is prevented. Therefore, power transmission can be performed stably over a long period of time.
The power transmission device of the present invention is not limited to a mode in which the groove widths of both the drive pulley and the driven pulley are changed, but only one of the groove widths is changed and the other is a fixed width that does not change. It may be an embodiment. In the above description, the groove width continuously (steplessly) has been described. However, the groove width may vary stepwise, or may be applied to other power transmission devices such as a fixed type (no shift). Also good.

It is a perspective view which shows typically the principal part structure of a chain. It is a front view which shows the state in which the pin member and the strip were provided in the link. It is a perspective view which shows typically the principal part structure of a power transmission device. It is a partial expanded sectional view of the drive pulley (driven pulley) and chain of a continuously variable transmission.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power transmission chain 2 Link 3 Pin member 5 Stress relaxation hole 10 Drive pulley 20 Driven pulley 22a, 23a Sheave surface

Claims (4)

A plurality of substantially rectangular links having through holes, and a plurality of pin members that are inserted through the through holes and connect the plurality of links to each other;
The first pulley having a conical surface sheave surface and the second pulley having a conical surface sheave surface are used in a bridging manner and are in contact with the sheave surfaces of the first and second pulleys. An annular power transmission chain for transmitting power,
The link has a stress relaxation hole in the vicinity of a corner for relaxing a stress generated by a force received from the pin member.   2. The power transmission chain according to claim 1, wherein the stress relaxation hole is provided in the vicinity of an inner peripheral side corner of at least a front portion of the link in the chain traveling direction.   The power transmission chain according to claim 1, wherein the plurality of pin members are inserted into the through holes in a press-fit state. A first pulley having a conical sheave surface;
A second pulley having a conical sheave surface;
A power transmission device comprising a power transmission chain that spans between the first and second pulleys, contacts the sheave surfaces of the first and second pulleys, and transmits power between the two pulleys by frictional force. Because
The power transmission chain according to any one of claims 1 to 3, wherein the power transmission chain is a power transmission chain.

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