CN1864016A - Power transmission chain and power transmission device using the same - Google Patents

Abstract

The invention provides a power transmission chain capable of effectively reducing generated sound and a power transmission device using the power transmission chain. A power transmission chain comprising: a plurality of links having through holes; and a plurality of pins inserted into the through holes to connect the plurality of links to each other, wherein the plurality of pins include a plurality of types of pins having substantially the same longitudinal length and different rigidities against forces acting in the longitudinal direction of the pins. In addition, two or more types of combinations of the pin and the strip are formed, in which the locus of the contact position of the pin and the strip is an involute of a circle, and the base radii of the involute are different.

Description

Power transmission chain and power transmission device using the chain

technical field

The present invention relates to a power transmission chain used in a chain-type continuously variable transmission of a vehicle, etc., and a power transmission device using the power transmission chain.

Background technique

As an automotive continuously variable transmission (CVT: Continuously Variable Transmission), there is, for example, the following transmission, which has: a driving pulley provided on the engine side, a driven pulley provided on the driving pulley side, and a ring-shaped pulley installed between these two pulleys. Ribbon chain. As the power transmission chain, there is a chain having a plurality of links and a plurality of pins connecting the links with each other. In this so-called chain-type continuously variable transmission, the traction force is generated by the contact friction acting between the sheave surface composed of two conical surfaces arranged approximately opposite to each other on the inner side of each pulley and the chain pin end surface of the chain, and transmit power. In some cases, chain friction transmission members are provided at regular intervals in the chain length direction as parts independent of the chain pins, and the chain friction transmission member acts between both end surfaces of the chain friction transmission member and the sheave surface. Contact friction creates traction and transmits power. In this way, the distance (groove width) between the substantially opposite conical surface sheave surfaces of each driving pulley and driven pulley is continuously changed, thereby continuously changing the effective diameter of each pulley. As a result, the transmission ratio can be changed continuously (steplessly), and the stepless transmission can be performed in a smooth operation different from conventional gears.

In such a chain-type continuously variable transmission, unpleasant noises are generated when the pins of the chain being stretched and the like enter and separate from the sheave surfaces of the respective pulleys. In particular, when the chain pin enters the sheave face, the chain pin collides with the sheave face to generate sound. Since a plurality of chain pins are provided at predetermined pitches in the belt length direction of the chain, these plurality of chain pins will successively collide with the sheave surface one by one to generate sound.

In a typical chain, since the multiple pins have the same length as each other, all the pins will interfere with the sheave surface equally. In this way, the frequency of the sound generated by the collision of each chain pin is approximately equal, so the sound generated at this frequency will increase, resulting in an increase in the sound pressure level. For this reason, an invention was proposed in JP Unexamined Publication No. 63-53337, which uses a plurality of chain pins with different lengths to disperse the generated sound frequency, or to reduce the sound pressure level by suppressing resonance. .

In JP Unexamined Publication No. 8-312725, as a power transmission chain for a continuously variable transmission, the following transmission chain is proposed. Two through holes; a plurality of chain pins and a plurality of intermediate pieces, which pass through the first through hole of one chain link and the second through hole of other chain links, so that the chain links arranged in the chain width direction are mutually aligned The chain is flexibly connected in the length direction, wherein a chain pin fixed in the first through hole of one chain link and movably embedded in the second through hole of the other chain link, and a chain pin movably embedded in a chain link The intermediate piece fixed in the first through hole of the other chain link and fixed in the second through hole of the other chain link moves in relative rolling contact, thereby realizing the aforementioned bending, and the cross-sectional shape of the side of the chain pin is different from the contact part with the intermediate piece. becomes the involute of the circle.

However, in the aforementioned invention described in JP-A-63-53337, there is a disadvantage that long chain pins are more prone to concentrated wear than short chain pins. In this case, since the long chain pins tend to wear intensively and become shorter, the difference in length disappears, so that the noise reduction effect during use is reduced, and a sufficient effect cannot be obtained. In addition, since the force acting on the long chain pins is greater than that of the short chain pins, loads are concentrated on the long chain pins, deteriorating the durability of the chain. In addition, in the chain assembly process, chain pins having different lengths must be managed or assembled separately, which increases the burden of assembly and increases the cost.

Furthermore, in the power transmission chain described in JP-A-8-312725, since the chain is not a continuous body but a structure in which a plurality of links are connected, the generated polygonal vibration is suppressed, thereby To suppress the sound generated during operation. However, for example, when a continuously variable transmission employing this power transmission chain is mounted on a vehicle, in order to improve the quietness during operation as much as possible, it is necessary to further reduce the sound generated by the power transmission chain.

Contents of the invention

The present invention has been made in view of the aforementioned facts, and an object of the present invention is to provide a power transmission chain capable of effectively reducing generated sound.

In detail, the first object of the present invention is to provide a power transmission chain in which the chain pins have substantially the same length and can effectively reduce the generated sound. A second object of the present invention is to provide a power transmission chain capable of further reducing sound generated by polygonal vibration and effectively suppressing sound generated during operation, and a power transmission device using the power transmission chain.

In order to achieve the aforementioned purpose, especially the aforementioned first purpose, the power transmission chain of the first invention in the present invention includes: a plurality of chain links with through holes; a plurality of chain pins inserted through the aforementioned through holes and connected to each other a plurality of chain links, and the power transmission chain is used to be spanned between a first pulley having a conical sheave surface and a second pulley having a conical sheave surface, and both end surfaces of the chain pins are connected to the first pulley. contact with the sheave surface of the second pulley to transmit power, the power transmission chain is characterized in that: the aforementioned plurality of chain pins include various types of chain pins, the lengths of the various types of chain pins in the length direction of the chain pins are substantially the same, and for The rigidity of the force acting in the length direction of the chain pin is different. In this way, the principle of reducing the sound pressure level of the generated sound in a state in which the lengths of the chain pins are substantially the same by using the plurality of chain pins having different rigidities will be described later.

The lengths of the chain pins in the longitudinal direction are substantially the same, which means that the lengths of the chain pins in the longitudinal direction are within the range of error produced when the same length is produced by the usual method.

The power transmission chain of the first invention considered from another viewpoint has: a plurality of links; a plurality of chain pins interconnecting the plurality of links, and the power transmission chain is mounted on a first pulley having a conical sheave surface. It is used between the second pulley having a conical sheave surface, and the two end surfaces of the chain pin are in contact with the sheave surfaces of the first and second pulleys to transmit power. The power transmission chain is characterized in that: The plurality of chain pins include various types of chain pins, all of which have substantially the same length in the length direction of the chain pins and have different cross-sectional shapes or cross-sectional areas in a cross section perpendicular to the length direction of the chain pins. In this way, similar to the aforementioned invention, the sound pressure level of generated sound is reduced in a state in which the lengths of the chain pins are substantially the same by using a plurality of chain pins having different rigidities, the principle of which will be described later.

In addition, for the "different cross-sectional shapes or cross-sectional areas" here, the cross-sectional shapes or cross-sectional areas of two chain pins are compared in each cross-section at the same position in the length direction of the chain pins among the chain pins to be compared. In the case of , even if the cross-sectional shape or cross-sectional area of one of the cross-sections is different, it is considered to be equivalent to "the cross-sectional shape or cross-sectional area is different".

In the aforementioned first invention, the aforementioned plurality of chain pins may also include various types of chain pins respectively, and the aforementioned cross-sectional shapes and aforementioned cross-sectional areas at each position of the chain pin in a single chain pin in the length direction of the chain pins are different from those of the chain pins. The entire length of the chain pins is approximately the same, and the aforementioned cross-sectional areas are different between a plurality of chain pins. In this case, compared with the case where the cross-sectional shape and the cross-sectional area differ at each position in the longitudinal direction of the chain pin, the shape of the chain pin is simpler, and the chain pin is easier to manufacture.

The aforementioned invention in which the cross-sectional areas of the chain pins are different may also be configured in that the aforementioned plurality of chain pins include various types of chain pins having different widths in the chain length direction in the aforementioned cross section, and the aforementioned plurality of chain links include different pitches. In addition, the chain link with the longer pitch is inserted with a chain pin with wider width in the length direction of the chain. In this way, a chain link having a length corresponding to the lengthwise width of the chain pin can be formed, and a chain having various pins with different pitches can be easily designed.

The so-called pitch here refers to the interval in the chain length direction between the chain pins inserted in a single chain link. This pitch is the distance between the chain pins at the junction of the chain pin and the narrow strip, and the above-mentioned pitch is measured in a state where the chain is not bent (a state that is completely straightened).

In the aforementioned first invention, among the aforementioned types of chain pins with different cross-sectional areas, the cross-sectional area of the chain pin with the largest cross-sectional area is preferably 1.1 to 1.1 times the cross-sectional area of the chain pin with the smallest cross-sectional area. 2 times. If it is less than 1.1 times, there is a tendency that the effect of setting difference in cross-sectional area cannot be fully exerted, and if it is more than 2 times, there is an increase in the lengthwise distance (pitch) between the chain pins and the chain pins. There is a tendency to make the generated sound louder, but this does not happen in this embodiment.

In order to achieve the above-mentioned purpose, especially to achieve the above-mentioned second purpose, the power transmission chain of the second invention in the present invention is erected between the first pulley with a conical sheave surface and the second pulley with a conical sheave surface In addition, the end faces of a plurality of chain friction transmission members arranged at regular intervals in the length direction of the chain contact the sheave surfaces of the first and second pulleys to transmit power. The characteristics of this power transmission chain In that: it has: a plurality of chain links, which have first and second through holes arranged in the length direction of the chain; a plurality of first chain pins and a plurality of second chain pins, the chain pin passes through the first The through hole and the second through hole of other chain links are used to flexibly connect the chain links arranged in the chain width direction to each other in the chain length direction. The first chain pin fitted in the second through hole of the other link, and the second chain pin movably fitted in the first through hole of one link and fixed in the second through hole of the other link The pin moves relative to the rolling contact, thereby realizing the aforementioned bending, and more than two kinds of combinations of the first link pin and the second link pin are formed, and in this combination, the contact positions of these first link pins and the second link pin The locus of the involute is a circular involute, and the radius of the base circle of the involute is different. In addition, the plurality of chain friction transmission members include a plurality of chain friction transmission members having different rigidity against force in the chain width direction.

In this way, the locus of the contact position of the first link pin and the second link pin becomes a circular involute, whereby polygonal vibration can be suppressed. In addition, due to the combination of two or more first chain pins and second chain pins with different base circle radii of the involute, the resonance of polygonal vibration can be suppressed, thereby further improving the involute-based The effect of suppressing the sound produced. In addition, by adopting multiple types of chain friction transmission members with different rigidities, it is possible to disperse the frequency of the sound generated when the chain friction transmission member comes into contact with the sheave surface of the pulley, and reduce the peak sound pressure level of the generated sound. .

The above-mentioned chain friction transmission member of the second invention may be configured such that all of the lengths in the longitudinal direction are substantially the same. In this way, a power transmission chain in which the end surface eccentric wear of the specific chain friction transmission member is suppressed to a minimum and its performance can be maintained for a long period of time can be realized.

The term "substantially the same length in the longitudinal direction" means that the lengths in the longitudinal direction of a plurality of chain friction transmission members are within the range of error that occurs when the same length is produced by a normal method.

In the aforementioned second invention, the plurality of chain friction transmission members may include multiple types of chain friction transmission members having different cross-sectional shapes or cross-sectional areas in a cross-section perpendicular to the chain width direction.

In this way, the aforementioned rigidities of the chain friction transmission members can be easily made different from each other.

For the "different cross-sectional shape or cross-sectional area" here, the cross-sectional shape or cross-sectional area of two chain friction transmission parts in the cross-sections with the same position in the chain width direction between the chain friction transmission parts compared with each other In the case of comparing the areas, even if the cross-sectional shape or cross-sectional area of one of the cross-sections is different, it is considered to be equivalent to "the cross-sectional shape or cross-sectional area is different".

In the second invention, the first chain pin or the second chain pin may be a transmission chain pin also serving as the chain friction transmission member. In this way, it is not necessary to provide a chain friction transmission member independently of the chain pin, thereby reducing the number of parts of the power transmission chain and simplifying the assembly process.

In the second invention, it may also be constituted as follows: the plurality of transmission chain pins include a variety of transmission chain pins with different widths in the length direction of the chain on a section perpendicular to the length direction of the chain pins, and the plurality of chain links include their joints. Various chain links with different distances. In this case, since the link with the longer pitch is inserted with a chain pin having a wider width in the length direction of the chain, it is possible to form a chain whose length corresponds to that of the transmission chain pin. Directional width of the link. In this way, a power transmission chain with various transmission chain pins and different pitches can be easily designed.

In addition, since the pitches of the links are different, it is possible to easily vary the pitches in the chain length direction of the transmission chain pins which are frictional transmission members. When the chain length direction pitch of the transmission chain pin is different, since the contact pitch between the transmission chain pin and the pulley is also different, the period of the sound generated by the contact between the transmission chain pin and the pulley is dispersed, thereby Reduce the sound pressure level peaks that occur. In addition, in the case where the transmission link pins having a wider width in the longitudinal direction of the chain are inserted through links with longer pitches, it is easy to make the pitches of the transmission pins different, and to adjust the distance between the transmission pins. The rigidity of the force in the chain width direction is different, and the noise reduction effect can be further improved.

The so-called pitch here refers to the interval in the chain length direction between the chain pins inserted in a single chain link. The pitch is the distance between the chain pins at the junction of the first chain pin and the second chain pin, and is adjusted by the distance between the first through hole and the second through hole provided in a single chain link. In addition, the pitch is measured in an unbent state of the chain (completely straightened state).

The present invention relating to a power transmission device is a power transmission device comprising: a first pulley having a conical sheave surface; a second pulley having a conical sheave surface; A power transmission chain between pulleys, the power transmission device is characterized in that: the aforementioned power transmission chain is the power transmission chain described in any one of the aforementioned first or second inventions.

Like this, owing to have adopted above-mentioned each power transmission chain, thereby can realize the power transmission device that the sound that produces during a kind of operation is little etc. has the action effect of above-mentioned each chain.

In the aforementioned second invention, when any one of the first chain pin and the second chain pin is a transmission chain pin, one of the transmission chain pins among the first chain pins and the second chain pins is generally referred to as a "chain pin". Pin", rather than the side of the transmission chain pin, is generally called "narrow strip (strip)" or "insert piece (interpiece)". For this reason, hereinafter, the transmission chain pin in the first chain pin or the second chain pin is referred to as "chain pin" for short, and the side that is not the transmission chain pin is called "narrow strip".

As described above, the power transmission chain and the power transmission device according to the present invention can effectively reduce the generated sound. In particular, in the first invention, by varying the rigidity, cross-sectional area, etc. of the chain pins, it is possible to effectively reduce the generated sound while the lengths of the chain pins are substantially the same. According to the aforementioned second invention, since two or more first and second chain pins having different base circle radii of the involutes forming the mutual contact position trajectories are combined, and the rigidity of the chain friction transmission member is made to be different, it is possible to reduce the Vibrates in a polygonal shape and suppresses sound pressure level peaks of the generated sound.

Description of drawings

FIG. 1 is a perspective view typically showing the configuration of main parts of a chain for a chain-type continuously variable transmission according to an embodiment of the first invention and the second invention.

FIG. 2 is a side view of the chain of FIG. 1 .

3 is a graph showing sound pressure levels at frequencies of generated sounds in the power transmission device using the chain according to Comparative Example 1 of the first invention.

4 is a graph showing sound pressure levels at frequencies of generated sounds in the power transmission device using the chain according to the first embodiment of the first invention.

Figure 5 is a side view of a link used in the chain of Figure 1 .

Fig. 6 is a side view of a state in which a chain pin and a strip are inserted into a link of the chain of Fig. 1 .

Fig. 7 is a diagram showing the rolling contact movement of the chain pin and the strip in the chain of Fig. 1 .

Fig. 8 is a view showing chain pin trajectories when a conventional general power transmission chain is wound around a pulley.

Fig. 9 is a graph showing the relationship between pitch and amplitude in a conventional general power transmission chain.

Fig. 10 is a graph showing the relationship between the pitch and the approach angle in a conventional conventional power transmission chain.

Fig. 11 is a graph showing a general relationship between the radius of the base circle of the involute and the amplitude.

Fig. 12 is a graph showing a general relationship between the radius of the base circle of the involute and the entry angle.

13 is a graph comparing sounds generated in power transmission devices of Examples and Comparative Examples in the second invention.

Fig. 14 is a diagram for explaining a preferable involute shape.

15 is a perspective view showing a schematic configuration of a chain-type continuously variable transmission using a chain according to an embodiment of the present invention.

Fig. 16 is a cross-sectional view of the pulley portion of the continuously variable transmission of Fig. 15 .

Fig. 17 is a diagram showing an embodiment of a link in which a first through hole communicates with a second through hole.

Fig. 18 is a diagram showing another embodiment of a link in which a first through hole communicates with a second through hole.

Detailed ways

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view typically showing the configuration of main parts of a chain for a chain-type continuously variable transmission (hereinafter referred to as "chain") according to an embodiment of the first invention of the present invention. The chain 1 involved in this embodiment is in the shape of an endless belt as a whole, and is composed of the following parts: a plurality of metal chain links 2; a plurality of metal chain pins 3 for interconnecting these chain links 2; These chain pins 3 are slightly shorter narrow strips 5 . The links 2 and the pins 3 are formed of metal such as bearing steel, for example. In FIG. 1 , the description of the links in the vicinity of the approximate center in the width direction of the chain 1 is partially omitted.

As shown in Fig. 1, Fig. 6 and Fig. 7, each chain link 2 has an outer shape in which the corners of a substantially rectangular plate-shaped member are rounded, and is juxtaposed in the length direction of the chain link (consistent with the length direction of the chain). It has two through-holes 4 (first through-hole 41 and second through-hole 42 ). A narrow strip 5 and a chain pin 3 are respectively inserted into one through hole 4 . A plurality of links 2 are arranged repeatedly in the chain width direction, and are sequentially shifted in positions in the chain length direction. One chain pin 3 is inserted through the through-hole 4 of the chain link 2 which is shifted in the chain length direction and repeatedly arranged in the chain width direction, thereby connecting a plurality of chain links 2 to each other to form an endless belt-shaped chain 1 .

The end face 3t of the chain pin 3 is located outside the end face of the narrow bar 5 in the chain width direction. The protruding chain pin 3 is in contact with the sheave face of the pulley.

FIG. 15 is a perspective view showing a schematic configuration of a chain-type continuously variable transmission 50 which has the chain of the present invention and is one embodiment of the power transmission device of the present invention. This chain type continuously variable transmission 50 can be used, for example, as an automobile transmission, and has: a metal driving pulley 10 as a first pulley; a metal driven pulley 20 as a second pulley; The endless belt chain 1. The pulleys 10 and 20 are made of metal such as bearing steel, for example. In Fig. 15, for ease of understanding, the chain section is partially shown.

As shown in Figure 1, the chain pin 3 and the narrow strip 5 are bar-shaped parts with a roughly rectangular cross section, but in order to ensure the flexibility (hereinafter referred to as circumferential bending, etc.) that the chain 1 can be wound on the round pulley, the The cross-sectional shape and the shape of the through hole 4 are considered. One side of the chain pin 3 is partially in contact with one side of the adjacent strip 5 , and the contact state changes with the circumferential bending state of the chain 1 . This type of contact is a rolling-sliding contact, that is, a rolling contact or a sliding contact or a composite contact of the two. Among these contact methods, rolling contact is particularly preferred. In this case, vibration and noise during operation of the chain 1 can be effectively suppressed. Preferably on one side of a side of the chain pin 3 and a side of the narrow strip 5 adjacent thereto, a protrusion (convex curved surface) in the chain width direction is set, while the other side does not set the protrusion in the chain width direction, and It is flat in the chain width direction.

Because the chain pin 3 is in contact with the narrow strip 5 in this way, when the chain pin 3 is clamped by the sheave surface of the pulley, the phenomenon that the chain pin 3 rotates around the center of the chain pin axis generally does not take place. As a result, friction loss can be reduced and high power transmission efficiency can be ensured.

16 is a sectional view of the pulley 10 or 20 in the continuously variable transmission 50 (a sectional view of a section along the radial direction of the pulley 10 , 20 ). As shown in the figure, the end face 3t of the chain pin 3 of the chain 1 is in contact with the conical sheave faces 12a, 13a (22a, 23a) facing each other inside the pulley 10 (20), and the Contact friction to transmit traction.

As shown in the side view of the chain 1 in FIG. 2 , the chain pin 3 is composed of the following two types of chain pins 3f and 3h with different cross-sectional areas: a thick chain pin 3f with a larger cross-sectional area perpendicular to the length direction of the chain pin ; and the fine chain pin 3h with a smaller cross-sectional area. The thick chain pin 3f and the thin chain pin 3h have substantially the same length in the pin longitudinal direction. The so-called lengths of the chain pins in the length direction are substantially the same, which means that the lengths of the chain pins in the length direction are within the error range produced when the same length is produced by the usual method, for example, the length difference in the length direction of the chain pins is 60 μm the following.

For the thick chain pin 3f and the thin chain pin 3h, among each chain pin, the cross-sectional shape of each position in the chain pin length direction within a single chain pin (the cross-sectional shape of the cross section perpendicular to the chain pin length direction. Hereinafter referred to as the cross-sectional shape. ) and cross-sectional area (the cross-sectional area perpendicular to the length direction of the chain pin. Hereinafter referred to as the cross-sectional area.), it is approximately the same over the entire length of the chain pin length direction. That is, each chain pin has substantially the same cross-sectional shape at any position in the length direction of the chain pin, and has substantially the same cross-sectional area.

As shown in FIG. 2, the cross-sectional shape of the thick chain pin 3f is a shape in which the cross-sectional shape of the thin chain pin 3h is enlarged in the chain length direction. That is, when the cross-sectional shape of the thick chain pin 3f is compared with the cross-sectional shape of the thin chain pin 3h in the state attached to the chain 1, they have almost the same width in the chain thickness direction (vertical direction in FIG. 2 ). , but the width Lf of the chain length direction of the section of the thick chain pin 3f is greater than the width Lh of the chain length direction of the section of the thin chain pin 3h.

Comparing the cross-sectional area of the thick chain pin 3f with that of the thin chain pin 3h, the cross-sectional area of the thick chain pin 3f is 1.1 to 2 times that of the thin chain pin 3h.

The shape of the through hole 4 of the link 2 corresponds to the shape of the thick link pin 3f and the shape of the thin link pin 3h. That is, the thick through hole 4f through which the thick link pin 3f is inserted is larger than the thin through hole 4h through which the thin link pin 3h is inserted. In order to allow the chain 1 to bend in the circumferential direction, the shapes of the left and right through holes 4 in one link 2 are different from each other. Due to the aforementioned difference in shape, the through holes 4 through which the thick chain pins 3f are inserted are collectively referred to as thick through holes 4f, and the through holes 4 through which the thin chain pins 3h are inserted are collectively referred to as thin through holes 4h.

In the chain 1, various kinds of links 2 are used. That is, as shown in FIG. 2 , the link 2 includes a long link 2f having a thick through hole 4f and a short link 2h without a thick through hole 4f. In the long link 2f, one of the two through-holes 4 is a thick through-hole 4f, and the remaining one is a thin through-hole 4h. On the other hand, in the short link 2h, both the through holes 4 are thin through holes 4h.

Therefore, the pitch P1 of the long link 2f is longer than the pitch P2 of the short link 2h. In addition, corresponding to the above-mentioned pitches P1 and P2, the length X of the chain longitudinal direction of the long link 2f is larger than the length Y of the chain longitudinal direction of the short link 2h.

The chain 1 constituted as above has the following effects.

Since the thick chain pin 3f and the thin chain pin 3h have substantially the same length in the pin longitudinal direction, specific concentrated wear of the chain pin 3 does not occur.

Since the cross-sectional areas of the thick chain pin 3f and the thin chain pin 3h are different, the sound generated when the chain type continuously variable transmission 50 operates can be reduced. The principle is as follows.

In the chain type continuously variable transmission 50 shown in FIG. 15, when the chain 1 enters the sheave surfaces 12a, 13a, 22a, 23a of the pulleys 10, 20, the chain pin 3 of the chain 1 and these sheave surfaces will be formed. conflict, while squeezing the sheave face. Under its reaction, the chain pin 3 is squeezed from its end face 3t by the sheave surface, and the chain pin 3 receives the force in the direction in which the length of the chain pin is compressed, and deforms (hereinafter referred to as compression deformation, etc.). The chain pin 3 is elastically deformed by this force, and then deformed to return to its original shape (hereinafter, this deformation is referred to as recovery deformation, etc.), but in this recovery deformation, the sheave surfaces 12a, 13a, 22a are pressed again , 23a. Thereby, the pulleys 10 and 20 vibrate, and the vibration generates sound. There are other factors as the main cause of the sound, but the sound based on the aforementioned principle is the largest.

The chain 1 according to the present embodiment includes various types of pins 3 having different cross-sectional areas in a cross section perpendicular to the chain length direction of the pins 3 , that is, thick pins 3 f and thin pins 3 h . In the thick link pin 3f and the thin link pin 3h, the magnitude and timing of the force pressing each sheave surface are different in terms of the above-mentioned principle of sound generation. In particular, the method of the recovery deformation is different between the thick chain pin 3f and the thin chain pin 3h, and the magnitude and timing of the force applied to each sheave surface during the recovery deformation are also different. Therefore, the frequency of the sound generated by the pulleys 10, 20 can be dispersed, the peak value of the sound pressure level of the generated sound can be reduced, and the resonance of the pulleys 10, 20 can also be suppressed. Thereby, the sound generated when the chain type continuously variable transmission 50 operates can be reduced.

The thick chain pin 3f and the thin chain pin 3h have the same cross-sectional shape and cross-sectional area even at any position in the length direction of the chain pin within each chain pin. That is, in a single chain pin, even at any position in the length direction of the chain pin, the cross-sectional shape and cross-sectional area are the same. In this way, since the shape is relatively simple, it is easy to manufacture.

As described above, when the cross-sectional shape of the thick chain pin 3f is compared with the cross-sectional shape of the thin chain pin 3h in the state attached to the chain 1, the lengths of the two in the chain thickness direction (up and down direction in FIG. 2 ) are almost equal. The same, but the chain longitudinal width Lf of the thick chain pin 3f is larger than the width Lh of the thin chain pin 3h.

Therefore, the pitch of the link 2 corresponds to the cross-sectional shape of each of the chain pins 3f, 3h. That is, in the chain link 2 through which the thick chain pin 3f is inserted, a thick through hole 4 that is a large through hole 4 is provided corresponding to the thick chain pin 3f, but in order to correspond to the thick through hole 4f, it is necessary to use a joint 2f from the longer long link.

In the present embodiment, the lengths of the links themselves in the chain longitudinal direction differ according to the different pitch lengths.

In this way, the chain 1 can be easily designed by using a plurality of links 2 with different pitches and inserting a chain pin whose width in the chain longitudinal direction is wider as the pitch of the links is longer. That is, as described above, in the case of using multiple types of chain pins to reduce the generated sound, various types of chain pins can be produced by changing only the chain length direction width of the cross section of the chain pin 3, and correspondingly, each chain pin can be appropriately changed. Therefore, it is easy to design the chain 1 with different pitch and chain length direction width of the chain pin 3 section. In addition, by changing the length of the chain itself in the belt length direction according to the difference between the aforementioned pitch and the length direction width of the chain, it is easier to design, for example, compared with changing the width of the chain pin cross section in the vertical direction (chain thickness direction). chain 1.

Comparing the cross-sectional area of the thick chain pin 3f with that of the thin chain pin 3h, the cross-sectional area of the thick chain pin 3f is 1.1 to 2 times that of the thin chain pin 3h. If the value is less than 1.1 times, since the difference in the cross-sectional area of the various types of pins is small, the aforementioned noise reduction effect will be insufficient. And if this value is more than 2 times, then the interval (pitch) in the chain length direction between the chain pins will increase, and the energy of the sound will increase, which may increase the noise on the contrary. There are cases where chain pins are included that are too small in cross-sectional area for insufficient strength and rigidity, and chain pins that are too large in cross-sectional area for reducing the degree of freedom in design of the chain 1 . However, since it is set to 1.1 times to 2 times like this embodiment, the above-mentioned disadvantage does not exist. From this point of view, the cross-sectional area of the thick link pin 3f is more preferably 1.5 to 2 times the cross-sectional area of the thin link pin 3h.

In the aforementioned embodiment, two types of chain pins 3f and 3h having different cross-sectional areas are included, but the types of chain pins are not limited to two types, of course, and may be three or more types. In addition, chain pins having the same cross-sectional area but differing only in cross-sectional shape may be used. The reason for this is that in this case, the forces and timings applied to the pulleys 10 and 20 at the time of compression deformation and recovery deformation in the above-mentioned principle of sound generation are different.

As mentioned above, the cross-sectional area or cross-sectional shape of the chain pins is compared in the cross-sections of each position in the length direction of the chain pins. Since only one cross-section is different, for example, it is also possible to compare the cross-sectional area or cross-sectional shape of the chain pins in comparison. , the cross-sectional shape and cross-sectional area of the chain pin are almost the same at each position in the length direction of the chain pin, but only one chain pin has a constriction and a concave portion or a convex portion in a part of the chain pin length direction, so only the cross-sectional shape or The cross-sectional area is different. This is because, in this case as well, in the above-mentioned principle of sound generation, the forces and timings applied to the pulleys 10 and 20 at the time of compression deformation and recovery deformation are different.

In the present invention, as described above, it is preferable that a link with a longer pitch is inserted through a chain pin with a wider width in the longitudinal direction of the chain, for example, the following methods (A) and (B) are included here.

(A) There are two types of chain pins: a chain pin with a wider width in the length direction of the chain (hereinafter referred to as a thick chain pin) and a chain pin with a narrower width (hereinafter referred to as a thin chain pin). The chain links include the following two types: One of the two through holes is inserted through the thick chain pin, and the chain link A of the thin chain pin is inserted in the other through hole; the chain link B of the thin chain pin is inserted in the two through holes, and here In some cases, the pitch of link A is greater than the pitch of link B,

(B) Chain pins are divided into two types: thick chain pins and thin chain pins. There are three types of chain links: the chain link C that inserts the thick chain pins in both sides of the two through holes; The chain link D of the thick chain pin is inserted in the inside and the thin chain pin is inserted in the other through hole; the chain link E of the thin chain pin is inserted in both sides of the two through holes. The pitch has the following inequality relationship:

Chain link C > chain link D > chain link E.

From the examples of (A) and (B) above, it can be known that the above-mentioned so-called "the longer the pitch of the chain link, the longer the chain pin in the chain length direction" refers to "the chain pin inserted in a single chain link". The greater the sum of the widths of the pins in the chain longitudinal direction in the insertion portion, the longer the pitch of the link is used, and thus, it is possible to easily design a chain having various types of pins.

In the foregoing embodiments, various types of chain pins having different cross-sectional areas are used, but various types of chain pins having different rigidity against forces acting in the chain longitudinal direction may be used. This is because, in this case as well, as described above, in the principle of sound generation, the forces and timings acting on the pulleys 10 and 20 are different at the time of compression deformation and recovery deformation. In order to vary the aforementioned rigidity, for example, the following methods may be suitably adopted: varying the cross-sectional area and cross-sectional shape of the chain pin to vary the rigidity, varying the material of the chain pin, or varying the heat treatment of the metal pin.

In the power transmission chain of the present invention, it is preferable that the multiple types of pins be arranged irregularly in terms of the order of arrangement of the multiple types of pins. The reason is that through the aforementioned irregular arrangement, the frequency of the generated sound can be effectively dispersed to further reduce the resonance.

In order to obtain the optimal arrangement in this irregular arrangement, for example, a plurality of chains that randomly change the arrangement pattern of the chain pins can be used for experimentation, or simulated by a computer to determine the optimal arrangement that produces less sound. good arrangement.

In the foregoing embodiments, various types of links are used, but a single type of link may also be used. In order to make the link into a single type, it is preferable that all the link pins have the same cross-sectional shape of the pin at the portion inserted into the link. For this reason, for example, between all the chain pins, various chain pins having the same cross-sectional shape and cross-sectional area but different materials can be used, or it is also possible to use various chain pins to make the chain pins different from each other. The cross-sectional shapes of the lengthwise positions of the chain pins other than the joint insertion part are different from each other. When a single type of link is used, the number of parts of the chain can be reduced to facilitate parts management, and the assembling of the chain can be simplified, contributing to cost reduction.

(Inspection of the sound pressure level reduction effect based on the embodiment)

In order to verify the sound pressure level reduction effect of the first invention, verification based on Examples and Comparative Examples was performed. Fig. 3 is a graph showing the sound pressure level at each frequency of the sound generated during the measurement of the operation of the power transmission device having the chain of Comparative Example 1, which is the length direction of the chain pin. Chains having substantially the same length, one type of pin, and one type of link. In the chain of Comparative Example 1, the intervals (pitches) between the respective chain pins are equal over the entire length of the chain. Fig. 4 is a graph showing the case where the chain according to Example 1 is installed. The chain according to Example 1 includes two types of pins having substantially the same length in the longitudinal direction of the pins but having different widths in the chain length direction of the pins, And two kinds of chain links with different pitches of the chain links. This Example 1 is different from the aforementioned Comparative Example 1 in which the pitches are equal, in that the distance (pitch) between the chain pins in the chain is different. Except for the specifications of the chain pins and links, the specifications of the power transmission device of Example 1 and the power transmission device of Comparative Example 1 are completely the same.

In Example 1, two kinds of links, the link with the pitch P1 of 8.8 mm and the link with the pitch P2 of 8.2 mm, were used, and a thick chain pin with a width Lf of 2.5 mm in the chain length direction was used, and The two types of chain pins are thin chain pins whose width Lh in the chain longitudinal direction is 2.0 mm (80% of the width Lf) (see FIG. 2 ). In addition, the width La (see FIG. 2 ) in the chain thickness direction of both types of chain pins was 6 mm.

As shown in FIG. 3 and FIG. 4 , compared with Comparative Example 1, the maximum sound pressure level of Example 1 is reduced by about 10 dB.

Next, an embodiment of the second invention in the present invention will be described with reference to the drawings.

A schematic perspective view of the main configuration of a chain for a chain-type continuously variable transmission (hereinafter referred to as "chain") 100 according to an embodiment of the second invention is shown in FIG. 1 in the same way as the chain 1 of the first invention. The composition is the same as chain 1. That is, the chain 100 is in the shape of an endless belt as a whole, and is composed of the following components: a plurality of metal chain links 2; a plurality of metal chain pins 3 for interconnecting these chain links 2; These chain pins 3 are slightly shorter narrow strips 5 . The links 2 and the pins 3 are formed of metal such as bearing steel, for example. A plurality of narrow strips 5 are all the same shape. The plurality of chain pins 3 include chain pins having different cross-sectional shapes, but all the chain pins 3 have the same length in the longitudinal direction. The end surface 3t of the chain pin 3 is located on the outer side in the chain width direction than the end surface of the strip 5, and this end surface 3t is in contact with the sheave surface of the pulley. That is, in this chain 1, the pin 3 is a transmission pin which doubles as a chain friction transmission member.

Fig. 5 is a plan view of the chain link 2 of the chain 100 in the second invention, and the shape of the chain link 2 is also the same as that of the chain 1 of the aforementioned first invention. As shown in FIG. 5 and FIG. 1, each chain link 2 has a shape in which the corners of a slightly rectangular plate-shaped member are rounded, and has a side-by-side shape in its chain length direction (consistent with the chain length direction). Two through holes 4. Therefore, one narrow strip 5 and one chain pin 3 are respectively inserted into one through hole 4 . A plurality of chain links 2 are arranged repeatedly in the width direction of the chain, and are sequentially arranged with positions shifted in the length direction of the chain. In this way, the same chain pin 3 is inserted through the through hole 4 of the chain link 2 that is staggered in the chain length direction and repeatedly arranged in the chain width direction, thereby connecting a plurality of chain links 2 to form an endless belt. Chain 100.

As shown in FIG. 5 , the two through-holes 4 included in the link 2 are constituted by a first through-hole 41 and a second through-hole 42 aligned in the chain longitudinal direction. The shapes of the first through hole 41 and the second through hole 42 are different from each other, and the chain 1 can be bent in the chain length direction (the chain 1 can be wound around a round pulley) as described later. In the chain 1 , like all the links 2 , the first through hole 41 is located on one side in the chain longitudinal direction with respect to the second through hole 42 . In other words, in all the chain links 2 , the second through hole 42 is located on the other side of the chain length direction relative to the first through hole 41 .

FIG. 6 is a diagram showing a state in which a set of chain pins 3 and narrow strips 5 are respectively inserted into the first through holes 41 and the second through holes 42 . One group of chain pins 3 and narrow strips 5 pass through the first through hole 41 of one chain link 2 and the second through hole 42 of another chain link 2 in the plurality of chain links 2, thereby making the chain width direction The chain links 2 arranged side by side are flexibly connected to each other in the chain length direction.

As shown in Figure 6, taking a single chain link 2 as an example, the chain pin 3 is pressed into the first through hole 41 and fixed, and the narrow strip 5 in contact with the chain pin 3 is separated by a specified gap. to be inserted into the first through hole 41 so as to be movably embedded in the first through hole 41 . On the other hand, in the second through hole 42 of the chain link 2, the narrow strip 5 is pressed into the second through hole 42 and fixed, and the chain pin 3 contacting the narrow strip 5 is separated by a predetermined gap. to be inserted into the second through hole 42 so as to be movably embedded in the second through hole 42 .

As shown in FIG. 1 , the positions in the length direction of the chain are different from each other, and the two chain links 2 adjacent to each other in the width direction of the chain are configured such that a chain pin 3 is fixed to the first through hole 41 of one chain link 2 . and movably embedded in the second through hole 42 of the other chain link 2; the narrow strip 5 is movably embedded in the first through hole 41 of one chain link 2 and fixed to the other chain link 2 in the second through hole 42. In this way, the combination of the chain pin 3 inserted into the same through hole 4 (the first through hole 41 or the second through hole 42) and the narrow strip 5 moves relative to the rolling contact, thus the chain 1 can be bent in the chain length direction. .

Viewed from the side of the chain 1, the locus of the contact positions of these chain pins 3 and the narrow strip 5 is a kind of circular involute. Fig. 7 is a diagram showing the displacement state of the chain pin 3 and the narrow strip 5 while moving in rolling contact (strictly speaking, rolling contact including several sliding contacts. Also called rolling sliding contact.), wherein the first through For the hole 41, among the chain pin 3 and the narrow strip 5, only the narrow strip 5 moves (rotates) relative to the first through hole 41, while for the second through hole 42, among the chain pin 3 and the narrow strip 5, only the chain The pin 3 moves (rotates) relative to the second through hole 42 . This rolling contact movement occurs when the chain 1 bends along the length of the chain. However, the chain pin 3 is in constant contact with the strip 5 throughout the entire range of rolling contact movement, so transmission losses can be minimized, thereby ensuring high power transmission efficiency.

In order to make the track of the contact position between the chain pin 3 and the narrow strip 5 become a circular involute during the rolling contact movement between the aforementioned chain pin 3 and the narrow strip 5, it is necessary to make the contact surface 3a between the chain pin 3 and the narrow strip 5 The cross-sectional shape becomes an involute curve with a predetermined base circle radius R, and the contact surface 5a of one narrow strip 5 becomes a plane (the cross-sectional shape is a straight line). In addition, the cross-sectional shape of the contact surface 3a in the range where the chain pin 3 and the narrow strip 5 are in rolling contact (hereinafter also referred to as the action side surface) may be an involute curve.

In order to make the track of the contact position of the chain pin 3 and the narrow strip 5 a circular involute, as described in this embodiment, the contact surface 3 a of the chain pin 3 can be made into an involute shape, and the width of the narrow strip 5 can be made to be involute. The contact surface 5a is a flat surface, or vice versa, the contact surface 5a of the strip 5 is involute shape, and the contact surface 3a of the chain pin 3 is a flat surface. In addition, it is also possible to make either of the two contact surfaces 3a, 5a a curved surface, thereby making the above-mentioned trajectory a circular involute. In this case, the cross-sectional shape of each action side surface of the contact surface 3a and the contact surface 5a Preferably the same.

The involute in the present invention also includes a curve similar to an involute (slightly involute). The reason for this is that the aforementioned polygonal vibration can be suppressed to some extent even with a curve similar to an involute.

In this manner, the chain 1 has two or more types of chain pins 3 having different base circle radii of the involute in the cross-sectional shape of the contact surface 3a (action side). As a result, a combination of two or more types of chain pins 3 and narrow strips 5 whose trajectories of mutual contact positions, that is, base circle radii of involutes are different.

The plurality of chain pins 3 that are the chain friction transmission member includes a plurality of types of chain pins 3 having different rigidities against force in the chain width direction. In the present embodiment, the aforementioned rigidity is varied by varying the cross-sectional area of the link pin 3 . That is, although all the chain pins 3 are formed of the same material, by making the thickness of the chain pins 3 different, the rigidity against force in the chain width direction (chain length direction) can be made different. The side view of the chain 100 of the unbent portion is the same as that of the chain 1 described above, and as shown in FIG. 2 , the basic structure is the same as that of the chain 1 . That is, the chain pin 3 is composed of a thick chain pin 3f with a large cross-sectional area in a cross section perpendicular to the length direction of the chain pin, and a thin chain pin 3h with a small cross-sectional area. Kinds of chain pins 3f, 3h constitute. The thick chain pin 3f and the thin chain pin 3h have substantially the same length in the pin longitudinal direction. The term “substantially the same length in the longitudinal direction of the pins” means that the lengths of the plurality of pins in the longitudinal direction are within the range of error produced when the same length is produced by the usual method, for example, the difference in the length of the pins in the longitudinal direction is 60 μm or less.

For the thick chain pin 3f and the thin chain pin 3h, in each chain pin, the cross-sectional shape of each position in the length direction of the chain pin in a single chain pin (the cross-sectional shape of the cross section perpendicular to the length direction of the chain pin, hereinafter referred to as the cross-section Shape) and cross-sectional area (the cross-sectional area of the cross-section perpendicular to the length direction of the chain pin, hereinafter referred to as the cross-sectional area), are approximately the same over the entire length of the chain pin length direction. That is, each chain pin has substantially the same cross-sectional shape at any position in the longitudinal direction of the chain pin, and has substantially the same cross-sectional area.

As shown in FIG. 2, the cross-sectional shape of the thick chain pin 3f is a shape in which the cross-sectional shape of the thin chain pin 3h is enlarged in the chain length direction. That is, when the cross-sectional shape of the thick chain pin 3f is compared with the cross-sectional shape of the thin chain pin 3h in the state attached to the chain 100, they have almost the same width in the chain thickness direction (vertical direction in FIG. 2 ). , but the width Lf of the chain length direction of the section of the thick chain pin 3f is greater than the width Lh of the chain length direction of the section of the thin chain pin 3h.

If the cross-sectional area of the thick chain pin 3f is compared with the cross-sectional area of the thin chain pin 3h, the cross-sectional area of the thick chain pin 3f is preferably 1.01 to 2 times the cross-sectional area of the thin chain pin 3h, more preferably 1.1 to 2 times the cross-sectional area of the thin chain pin 3h. 2 times.

The shape of the through hole 4 of the link 2 corresponds to the shape of the thick link pin 3f and the shape of the thin link pin 3h. That is, the thick through hole 4f through which the thick link pin 3f is inserted is larger than the thin through hole 4h through which the thin link pin 3h is inserted. As mentioned above, in order to make the chain 100 bendable in the chain length direction, the shapes of the first through hole 41 and the second through hole 42, which are the left and right through holes 4 in one link 2, are different from each other. In this specification, when referring to the thick through hole 4f or the thin through hole 4h, regardless of the difference between the first through hole 41 and the second through hole 42, the through hole 4 through which the thick chain pin 3f is inserted is collectively referred to as a thick through hole. The hole 4f and the through hole 4 through which the thin chain pin 3h is inserted are collectively referred to as the thin through hole 4h. The thick through-hole 4f may be either the first through-hole 41 or the second through-hole 42 , and the thin through-hole 4h may be either the first through-hole 41 or the second through-hole 42 .

In the chain 100, various types of links 2 are used. That is, as shown in FIG. 2 , the link 2 includes: a long link 2f having a thick through hole 4f, and a short link 2h without a thick through hole 4f. In the long link 2f, one of the two through-holes 4 is a thick through-hole 4f, and the other one is a thin through-hole 4h. On the other hand, in the short link 2h, both the through holes 4 are thin through holes 4h.

Therefore, the pitch P1 of the long links 2f is longer than the pitch P2 of the short links 2h. In addition, corresponding to the above-mentioned pitches P1 and P2, the length X of the chain longitudinal direction of the long link 2f is longer than the length Y of the chain longitudinal direction of the short link 2h. Therefore, as the pitches of the links 2f and 2h differ, the pitches of the pins 3 inserted through the links also vary.

When multiple pitches are provided in the chain 100, if the longest pitch is about 1.1 to 1.3 times, especially about 1.2 times, the shortest pitch, the effect of setting multiple pitches can be fully exerted. Furthermore, it is preferable that the longest pitch is not too long. When multiple types of links 2 having different lengths (length in the chain length direction) of the links 2 are provided, the number of the longest links is preferably 1/4 or less of the number of the shortest links. The reason for this is that if the ratio is too high, there will be too many long links, resulting in an increase in the long-pitch portion, which increases the generated sound. However, if the ratio is small, the effect of varying the lengths of the links is reduced, so the number of the longest links is preferably 15% or more of the number of the shortest links.

As described above, although there are two or more types of chain pins 3 having different base circle radii of the involute in the cross-sectional shape of the contact surface 3a, the involute shape and the chain pin 3 can be The thickness can be combined freely. For example, if the radius of the base circle of the involute is set to R1 and R2, and when R1>R2, then the radius of the base circle of the involute in the cross-sectional shape of the thin chain pin 3h can be set to R1, and the thick The radius of the chain pin 3f is R2. Conversely, the radius of the involute basic circle in the cross-sectional shape of the thick chain pin 3f may be R1, and the radius of the thin chain pin 3h may be R2.

FIG. 15 is a perspective view showing a schematic configuration of a chain-type continuously variable transmission 50 which has the chain 100 of the present invention and is one embodiment of the power transmission device of the present invention. As described above in the description of the first invention, this chain-type continuously variable transmission 50 can be used, for example, as a transmission for automobiles, and has: a metal driving pulley 10 as a first pulley; a metal driven pulley as a second pulley. 20 ; an endless belt-shaped chain 100 stretched between these pulleys 10 , 20 . The pulleys 10 and 20 are made of metal such as bearing steel, for example. In FIG. 15 , for ease of understanding, only a section of the chain 100 is partially shown.

FIG. 16 is a sectional view of the pulley 10 or 20 of the continuously variable transmission 50 (a sectional view taken along the radial direction of the pulley 10 , 20 ). As shown in the figure, the end faces 3t of the chain pins 3 in the chain 100 are in contact with the conical sheave faces 12a, 13a (22a, 23a) facing each other inside the pulley 10 (20), and pass through The contact friction is used to transmit the tractive force. Thus, the chain pin 3 is a transmission chain pin which doubles as a frictional transmission part of the chain.

In the chain 100, the thin pins 3h and the thick pins 3f are arranged in an irregular order (randomly). Since the short links 2h and the long links 2f are also arranged in an irregular order, the pitch P1 and the pitch P2 are also arranged in an irregular order (randomly). If the base circle radius of the involute is set to R1 and R2, and when R1>R2, then it can be the same as the chain pin 3 whose involute base circle radius is R1 in the cross-sectional shape, in an irregular order ( Randomly) to configure the chain pin 3 with radius R2. Although it is "irregular order", it does not have to be completely irregular over the entire circumference of the chain 100 .

The chain 100 constructed as described above has the following functions and effects.

Since the track of the contact position between the chain pin 3 and the narrow strip 5 is a circular involute, the polygonal shape has less vibration.

Regarding this point, firstly, it will be explained from the polygonal vibration. FIG. 8 schematically shows a chain pin track when a conventional general chain is wound around a pulley, viewed from the side of the chain. This figure shows the trajectory of the chain pin when the chain travels from the left side of the drawing to the right side and winds around the pulley (not shown) on the right side of the drawing, and the horizontal axis indicates the position from which the chain and the pulley start to mesh That is, the starting position of the engaged position (mm). On the front side (right side in the figure) of the chain travel direction from the engaged position, the chain is in a state of being wound around the pulley, so the chain pin trajectory becomes an arc shape corresponding to the winding radius of the chain 100, and On the front side (left side in the figure) in the forward direction of the chain from the engaged position, the chain pin trajectory vibrates up and down like a wave. This is polygonal vibration. The reason for this polygonal vibration is that when links are connected to form a chain, and when the chain is bent in the lengthwise direction of the chain, it does not become a perfect circular arc shape but becomes a polygonal shape. That is, in this case, at the engaged position, the tangential direction of the pulley and the entry direction of the chain pin will be different, and the entry angle shown in FIG. 8 will be generated, so that the chain pin will contact the pulley while descending. The drop amount of the pin at the moment when the pulley comes into contact with the pin is expressed as the amount of change in the initial engagement position. The vertical motion of the chain is generated by the lowering of the chain pin, and polygonal vibration is generated by the repetition of the aforementioned vertical vibration. If the above-mentioned contact position trajectory becomes a circular involute, the above-mentioned entry angle (see FIG. 8 ) can be reduced, and the amount of change in the initial engagement position can be reduced, thereby suppressing polygonal vibration.

Therefore, since the combination of two or more types of chain pins 3 and narrow strips 5 having different involute base circle radii is formed, resonance of polygonal vibrations can be suppressed, thereby reducing sound generated by the polygonal vibrations.

Since the cross-sectional areas of the thick chain pin 3f and the thin chain pin 3h are different, the sound generated when the chain type continuously variable transmission 50 operates can be reduced. The principle is as follows.

In the chain type continuously variable transmission 50 shown in FIG. 15, when the chain 100 enters the sheave surfaces 12a, 13a, 22a, 23a of the pulleys 10, 20, the chain pin 3 of the chain 100 conflicts with these sheave surfaces. , and squeeze the sheave face. Under its reaction, the chain pin 3 is pressed by the sheave surface from the end surface 3t, and the chain pin 3 is deformed by a force compressing the length of the chain pin in the longitudinal direction (hereinafter, the deformation is referred to as compression deformation, etc.). The chain pin 3 is elastically deformed by this force, and then deformed to return to its original shape (hereinafter this deformation is referred to as recovery deformation, etc.), but during this recovery deformation, the sheave surfaces 12a, 13a, 22a are pressed , 23a. Due to this principle (hereinafter also referred to as the principle of sound generation) the pulleys 10, 20 vibrate, and this vibration will emit sound.

The chain 100 of the present embodiment includes various types of pins 3 having different cross-sectional areas perpendicular to the pin length direction of the pins 3 , that is, thick pins 3 f and thin pins 3 h . In the thick chain pin 3f and the thin chain pin 3h, the magnitude and time of the force pressing each sheave surface in the principle of sound generation are different. In particular, the method of the recovery deformation is different between the thick link pin 3f and the thin link pin 3h, and the magnitude and timing of the force applied to each sheave surface during the recovery deformation are also different. Accordingly, the frequency of sound generated from the pulleys 10, 20 can be dispersed, so that the peak value of the sound pressure level of the generated sound can be reduced, and resonance of the pulleys 10, 20 can be suppressed. Therefore, the sound generated when the chain type continuously variable transmission 50 operates is reduced.

The thick chain pin 3f and the thin chain pin 3h have the same cross-sectional shape and cross-sectional area in each chain pin even at any position in the length direction of the chain pin. That is, in a single chain pin, even at any position in the length direction of the chain pin, the cross-sectional shape and cross-sectional area are the same. Thus, since the shape is relatively simple, it is easy to manufacture.

Since the thick chain pin 3f and the thin chain pin 3h have substantially the same length in the pin longitudinal direction, concentrated wear does not occur on a specific chain pin 3 .

As described above, when the cross-sectional shape of the thick chain pin 3f is compared with the cross-sectional shape of the thin chain pin 3h in the state attached to the chain 100, the lengths in the chain thickness direction (vertical direction in FIG. 2 ) of the two are almost the same. , but the chain longitudinal width Lf of the thick chain pin 3f is longer than the width Lh of the thin chain pin 3h.

Therefore, the pitch of the link 2 corresponds to the cross-sectional shape of the respective link pins 3f, 3h. That is, in the link 2 through which the thick chain pin 3f is inserted, the thick through hole 4f which is a large through hole 4 is provided corresponding to the thick chain pin 3f, but in order to correspond to the thick through hole 4f, a Long links 2f with longer pitches.

Furthermore, in the present embodiment, the lengths of the links themselves in the chain longitudinal direction differ according to the different pitch lengths.

In this way, the chain 100 can be easily designed by using a plurality of links 2 with different pitches and inserting a chain pin having a wider width in the chain longitudinal direction as the pitch of the links increases. That is, in the case of using multiple types of chain pins to reduce the sound generated as described above, various types of chain pins 3 are produced by changing only the chain length direction width of the cross section of the chain pins 3, and correspondingly, each chain pin is appropriately changed. Therefore, it is easy to design the chain 100 with different pitches and widths in the chain length direction of the cross-section of the chain pins 3 . In addition, by changing the length in the belt length direction of the chain itself in accordance with the difference in the aforementioned pitch and the width in the length direction of the chain, it is possible to achieve greater Easy to design chain 100.

The pitches of the links differ by the long links 2f and the short links 2h, and therefore the pitches of the chain pins 3 in the chain longitudinal direction also differ. Since the chain lengthwise pitches of the chain pins 3 are different, the contact pitches between the chain pins 3 and the pulley are also different. Accordingly, the frequency of the sound generated by the contact of the chain pin 3 with the pulley can be dispersed, so that the peak sound pressure level of the generated sound can be reduced. Since the chain pin 3 having a wider width in the longitudinal direction of the chain is inserted as the pitch of the link is longer, the chain pin 3 can be easily adjusted to the width of the chain while making the pitch of the chain pin 3 different. The rigidity of the force in the direction is different, so the noise reduction effect is better.

When the cross-sectional area of the thick chain pin 3f is compared with the cross-sectional area of the thin chain pin 3h, the cross-sectional area of the thick chain pin 3f is preferably 1.01 to 2 times the cross-sectional area of the thin chain pin 3h. If the value is less than 1.01 times, since the difference in the cross-sectional area of the various types of pins is small, the aforementioned noise reduction effect will be insufficient. On the other hand, if the value is more than 2 times, the interval (pitch) in the chain length direction between the chain pins will increase, and the sound energy will increase, which may increase the generated sound. There are occasions where a chain pin whose cross-sectional area is too small and insufficient in strength and rigidity is included, and a chain pin whose cross-sectional area is too large so that the design freedom of the chain 100 is reduced may be included. However, by setting it as 1.01 times to 2 times like this embodiment, the above-mentioned disadvantage does not exist. From this point of view, the cross-sectional area of the thick link pin 3f is preferably 1.5 to 2 times the cross-sectional area of the thin link pin 3h.

In the foregoing embodiments, the case where there are two types of base circle radii of the involute are described, but there may be three or more types. Similarly, the rigidity and pitch of the chain pins are not limited to the two occasions described in the foregoing embodiments, and may be more than three. However, if there are too many types, parts management costs and manufacturing costs will increase. If the chain pin rigidity, pitch, and involute base circle radius are respectively two to three, a sufficient noise reduction effect can be obtained, and the balance with cost is good, so it is preferable.

In order to make the pin rigidity (rigidity against force in the chain width direction) different, the cross-sectional area may be the same but only the cross-sectional shape may be different, or both the cross-sectional area and cross-sectional shape may be the same and only the material may be different. Instead of only making different materials, it is also possible to use the same material but make different heat treatments. Furthermore, as another method for making the rigidity different, for example, a method may be adopted in which the cross-sectional shape and the cross-sectional area of the chain pins are almost the same at almost every position in the length direction of the chain pins between the chain pins to be compared. They are the same, but only one chain pin has a constriction, a concave portion, a convex portion, etc. in a part in the length direction of the chain pin, so only in this part, the cross-sectional shape or cross-sectional area is different.

In order to vary the rigidity of the chain pin (the rigidity against the force in the width direction of the chain), recesses such as grooves may be formed on the back surface 3d (see FIG. 6 ), which is the surface opposite to the contact surface 3a of the chain pin 3, whereby To change the chain pin sectional area of chain pin 3. In this case, a plurality of identical chain pins 3 can also be fabricated in advance, and recesses such as grooves can be provided or not provided on the back surface 3d of the chain pins 3, and the shape and arrangement can be changed to change the cross-sectional area of the chain pins. And the cross-sectional shape of the chain pin. In this case, there are advantages that the rigidity can be changed only by simple processing (groove processing, etc.), the type of the chain pin 3 can be easily identified by the groove, and the cross section of the contact surface 3a is not affected even if the recess is processed. shape and the shape of the through hole 4.

In the present invention, as described above, it is preferable that a link with a longer pitch is inserted through a chain pin with a wider width in the longitudinal direction of the chain, including the following (A) and (B), for example.

(A) There are two types of chain pins: a chain pin with a wider width in the length direction of the chain (hereinafter referred to as a thick chain pin) and a chain pin with a narrower width (hereinafter referred to as a thin chain pin). The chain links include the following two types: One of the two through holes is inserted through the thick chain pin, and the chain link A of the thin chain pin is inserted in the other through hole; the chain link B of the thin chain pin is inserted in the two through holes, and here In some cases, the pitch of link A is greater than the pitch of link B,

(B) Chain pins are divided into two types: thick chain pins and thin chain pins. There are three types of chain links: the chain link C that inserts the thick chain pins in both sides of the two through holes; The chain link D that passes through the thick chain pin and the thin chain pin in the other through hole; the chain link E that inserts the thin chain pin in both sides of the two through holes. In the above occasions, these chain links The pitch has the following inequality relationship:

Chain link C > chain link D > chain link E.

From the examples of (A) and (B) above, it can be known that the above-mentioned so-called "the longer the pitch of the chain link, the longer the chain pin in the chain length direction" refers to "the chain pin inserted in a single chain link". The greater the sum of the widths of the pins in the chain longitudinal direction in the insertion portion, the longer the pitch of the link is used, and thus, it is possible to easily design a chain having various types of pins.

As mentioned above, although it is preferable to arrange various chain pin rigidities, various pitches, and various involute shapes in an irregular order (randomly), in order to find the optimum Arrangement, for example, can be tested by using a plurality of chains in which each arrangement pattern is randomly changed, or simulated by a computer, so as to determine the optimal arrangement that produces a smaller sound.

In general, the relationship between the amplitude and pitch of polygonal vibration tends to increase the amplitude as the pitch increases (see FIG. 9 ). Similarly, the relationship between the entry angle and the pitch shown in FIG. 10 also tends to increase the entry angle as the pitch increases. On the other hand, there is a tendency that, as shown in Figure 11, even if the radius of the base circle of the involute is increased, the amplitude of the polygonal vibration does not increase much. In addition, as shown in Figure 12, when the involute When the radius of the base circle is , the entry angle decreases. Therefore, when the radius of the base circle of the involute is increased with the combination of the chain pin 3 and the narrow strip 5 forming a long pitch, it is possible to set a variety of involutes while eliminating the defects caused by the increase of the pitch. Open wire base circle radius and pitch are therefore preferred.

In the graphs of Fig. 11 and Fig. 12, the so-called small radius of rotation refers to the case where the winding radius of the chain is 31.65 mm, and the so-called large radius of rotation refers to the case where the winding radius is 73.859 mm.

Preferably, the smaller the radius of the base circle of the involute is, the less rigid the chain pin is. The reason for this is that although the sound (knocking sound) generated by the chain pin with a small base circle radius tends to increase easily, by reducing the rigidity of the chain pin with a small base circle radius, the generated noise can be absorbed (moderated). The volume of the sound (percussion sound).

Hereinafter, preferred embodiments of the cross-sectional shape of the contact surface 3 a of the chain pin 3 in the chain 100 of the above-mentioned embodiment will be described. FIG. 14 is a diagram for explaining this preferred shape, and is a side view of the chain pin 3 viewed from the end surface 3t direction. In the contact surface 3a of the chain pin 3, the active side of the rolling contact with the narrow strip 5 is: from the contact line A of the chain pin 3 and the narrow strip 5 in the unbent state of the chain 100 (represented by a point in FIG. It is called the area from point A) to the contact line B (shown by dots in FIG. 14 ). Therefore, including the profile line of the action side, the profile line of the contact surface 3a is constituted by a smooth convex curve.

As for the involute curve of the acting side on the cross section of the chain pin 3, as shown in FIG. In this way, when the base circle radius Rb is set as the distance dA ( (not shown)), the polygonal vibration will reach the minimum limit, so it is preferable. However, for example, in the case of a CVT for automobiles, since the winding radius changes within a predetermined range, the aforementioned distance dA also changes. Therefore, in this case, if dA at the maximum winding radius is dAx, and dA at the minimum winding radius is dAn, it is preferable to set the base circle radius Rb to 1/4 (dAn)≦Rb≦2(dAx), and within this range, the basic circle radius Rb is set to various types.

(Verification of the sound pressure level reduction effect based on the embodiment)

In order to confirm the sound pressure level reduction effect of 2nd invention, the verification based on an Example and a comparative example was performed. Fig. 13 is a graph comparing the measured and compared sounds generated during operation of the power transmission devices of Example 2 and Comparative Examples 2 and 3 under the same conditions. In Example 2, the same configuration as the embodiment of the aforementioned second invention is adopted, and two types are mixed for the three items of the radius of the base circle of the involute, the cross-sectional area of the chain pin 3, and the chain pin, respectively, and arranged irregularly. In Comparative Example 3, the cross-sectional shape of the chain pin 3 is a convex curve (convex) instead of an involute, and only one type of rigidity and pitch of the chain pin is used. In addition, Comparative Example 2 is a metal belt that has been practically used in a conventional CVT for automobiles. Its structure is that a steel belt is connected with a thin-walled stopper (coma), and the stopper is arranged in a direction perpendicular to the longitudinal direction of the belt and in the There are multiple overlapping tapes in the length direction. It is well known that Comparative Example 2 generates less sound than the conventional power transmission chain of Comparative Example 3, but is less flexible, so the degree of freedom of the speed change ratio is smaller than that of the chain type of Comparative Example 3.

For these three examples, the generated sound was measured at four rotational speeds, and both the maximum sound pressure level (dBA) and the combined value (dBA) were compared. As a result, as shown in FIG. 13 , in the comparison of the maximum sound pressure level (dBA), the sound generated by Example 2 was lower than that of Comparative Example 3 in all four rotational speeds. In particular, at 1000 rpm and 2000 rpm, the value of Example 2 is lower than that of Comparative Examples 2 and 3, and the generated sound is lower than that of Comparative Example 2, which is a metal belt type with high quietness. In the comparison of the overall value (dBA), the sound generated in Example 2 was lower than that of Comparative Example 2 and Comparative Example 3 at all rotational speeds.

In the above-mentioned embodiment, although the case where the chain pin 3 also serves as a chain friction transmission member was exemplified, it is also possible to provide a chain friction transmission member independent of the first and second chain pins which are in rolling contact with each other. For example, it may also be configured such that a plurality of bar-shaped members extending parallel to the first chain pin and the second chain pin in the chain width direction are provided at predetermined intervals in the chain length direction, and are further toward the chain than the two chain pins. The chain friction transmission member (friction block) protruding from both sides in the width direction makes both end surfaces of the chain friction transmission member contact the sheave surface of the pulley to transmit power.

The configuration of the continuously variable transmission 50 using the chains of the first invention and the second invention as a transmission will be described below. The drive pulley 10 shown in FIG. 15 is mounted rotatably on an input shaft 11 connected to the engine side, and includes: a fixed sheave 12 having a conical sheave surface 12a; and the sheave surface 12a The movable sheave 13 which has the conical sheave surface 13a arranged oppositely. In this way, the chain 1 (chain 100 ) is clamped with strong pressure from the side by these sheave surfaces 12a, 13a. A hydraulic transmission (not shown) is connected to the movable sheave 13 so that the movable sheave 13 can move in the axial direction of the input shaft 11 . When the movable sheave 13 moves, the opposing distance (groove width) of the opposing sheave surfaces 12a, 13a changes. Since the chain width of the chain 1 (chain 100) remains constant, the chain 1 (chain 100) is wound at a radial position corresponding to the chain width, and the winding radius of the chain 1 (chain 100) is changed.

On the other hand, the winding radius of the chain 1 (chain 100 ) is changed similarly to the driven pulley 20 by the same principle as that of the driving pulley 10 .

The driven pulley 20 is integrally rotatably mounted on the output shaft 21 connected to the drive wheel side, and includes: a fixed sheave 22 having a conical sheave surface 22a; The movable sheave 23 has a conical sheave surface 23a. In this way, the chain 1 (chain 100 ) is clamped with strong pressure from the side by these sheave surfaces 22a, 23a. Furthermore, a hydraulic transmission (not shown) is connected to the movable sheave 23 , whereby the movable sheave 23 can move in the axial direction of the output shaft 21 . When the movable sheave 23 moves, the opposing distance (groove width) of the opposing sheave surfaces 22a, 23a changes. Since the chain width of the chain 1 (chain 100) remains constant, the chain is wound at a radial position corresponding to the chain width, thereby changing the winding radius of the chain.

When shifting to a lower gear state, the groove width on the driving pulley 10 side is enlarged by the movement of the movable sheave 13, thereby reducing the winding radius of the chain 1 (chain 100) on the driving pulley 10, Furthermore, the movement of the movable sheave 23 reduces the groove width on the side of the driven pulley 20 , thereby increasing the winding radius of the chain 1 (chain 100 ) around the driven pulley 20 .

Conversely, when the gear is shifted to a higher gear state, the groove width on the drive pulley 10 side is reduced by the movement of the movable sheave 13, thereby enlarging the winding radius of the chain 1 (chain 100) on the drive pulley 10. , and, by moving the movable sheave 23, the groove width on the side of the driven pulley 20 is enlarged, thereby reducing the winding radius of the chain 1 (chain 100) on the driven pulley 20. In this way, the continuously variable speed function is brought into play.

The chain of the present invention can reduce the sound pressure level of the sound generated during operation in the power transmission device such as the aforementioned chain type continuously variable transmission 50 .

In the above-mentioned embodiments of the first invention and the second invention, the first through hole 41 and the second through hole 42 of the link 2 are not communicated with each other (refer to FIG. 5 ), but as shown in FIG. 17 and FIG. 18 , in this In the inventions (the first invention and the second invention), the first through hole 41 and the second through hole 42 may communicate with each other. In the modified example shown in FIGS. 17 and 18 , the communicating portion R that communicates the first through hole 41 with the second through hole 42 is provided so that the division that divides the first through hole 41 and the second through hole 42 The portion 60 (see FIG. 5 etc.) is transversely cut in the length direction of the link.

By providing the communication portion R connecting the first through hole 41 and the second through hole 42, the deformation of the chain link 2 can be facilitated, and in the case of receiving a relatively large force from the chain pin 3 and the narrow strip 5, the through hole can be relaxed. Stress concentration on the peripheral portion improves the durability of the link. This stress concentration mitigating effect is particularly large in press-fit chains in which pins and narrow strips are fitted and fixed (fitted and fixed by press-fitting, shrink-fitting, cold-pressing, etc.) within the links.

In these modified examples, the communicating portion R is provided substantially at the center of the two through-holes 41 and 42 in the link width direction. In the modified example shown in FIG. 17 , the width of the communicating portion R is narrow, and in the modified example shown in FIG. 18 , the width of the communicating portion R is widened. If the width of the connecting portion R is reduced, the rigidity of the link can be increased compared with the case where the width of the connecting portion R is wide, and the deformation of the link can be suppressed when the link is produced by pressing. If the width of the communicating portion R is enlarged, the link 2 can be deformed more easily than when the width of the communicating portion R is narrowed, so the effect of alleviating stress concentration is greater. The width of the communicating portion R may also be appropriately determined according to link dimensions, load conditions, and the like.

As shown in Figure 7, since each through-hole 41,42 has the guide function of guiding the rolling contact movement of the chain pin 3 and the narrow strip 5 (refer to Figure 7), therefore when the first through-hole 41 and the second through-hole When the holes 42 are connected, the connecting portion R is arranged so as not to impair the above-mentioned guiding function. In order to maintain this guiding function, it is preferable to provide a communication portion R avoiding the contact surface between the chain pin 3 and the narrow strip 5 and the inner peripheral surface of each through hole 41, 42 (including all parts in contact during the aforementioned rolling contact movement). However, when the guide member having the aforementioned guiding function is provided independently of the link, the width of the communication portion R may be further enlarged to form a link without a portion having the aforementioned guiding function.

Claims (11)

1. A power transmission chain, comprising: a plurality of chain links, which have a through hole; a plurality of chain pins, which are inserted through the aforementioned through hole and interconnect the aforementioned plurality of chain links, the power transmission chain is erected on a surface with a conical surface It is used between the first pulley with a conical sheave surface and the second pulley with a conical sheave surface, and the two end surfaces of the chain pin are in contact with the sheave surfaces of the first and second pulleys to transmit power. The power transmission chain is characterized by: The plurality of chain pins include various types of chain pins in which the lengths in the longitudinal direction of the chain pins are all substantially the same and have different rigidities against forces acting in the lengthwise direction of the chain pins. 2. A power transmission chain having a plurality of links and a plurality of pins interconnecting the plurality of links, the power transmission chain being erected between a first pulley having a conical sheave surface and a first pulley having a conical groove It is used between the second pulley on the wheel surface, and the two end surfaces of the aforementioned chain pin are in contact with the sheave surfaces of the aforementioned first and second pulleys to transmit power. The power transmission chain is characterized by: The aforementioned plurality of chain pins include various types of chain pins, the lengths of the chain pins in the length direction are substantially the same, and the cross-sectional shapes or cross-sectional areas of the cross-sections perpendicular to the length direction of the chain pins are different. 3. The power transmission chain according to any one of claims 1 or 2, characterized in that: the aforementioned plurality of chain pins respectively include multiple types of chain pins, and the multiple types of chain pins are each in the length direction of the chain pins in a single chain pin. The positional cross-sectional shape and the cross-sectional area are substantially the same over the entire length of the chain pin, and the cross-sectional area is different among the plurality of chain pins. 4. The power transmission chain according to any one of claims 1-3, wherein the plurality of chain pins include various types of chain pins with different widths in the length direction of the chain in the aforementioned section, and the plurality of chain pins The link contains a variety of links with different pitches, and, A chain pin having a wider width in the longitudinal direction of the chain is inserted through the link whose pitch is longer. 5. The power transmission chain according to any one of claims 1 to 4, characterized in that: among the aforementioned chain pins with different cross-sectional areas, the cross-sectional area of the chain pin with the largest cross-sectional area is the aforementioned 1.1 to 2 times the cross-sectional area of the chain pin with the smallest cross-sectional area. 6. A power transmission chain used between a first pulley having a conical sheave surface and a second pulley having a conical sheave surface, and is used at regular intervals in the chain length direction The end faces of the plurality of chain friction transmission parts are in contact with the sheave surfaces of the first and second pulleys to transmit power. The power transmission chain is characterized by: It has: a plurality of chain links, which have first and second through holes arranged in the length direction of the chain; a plurality of first chain pins and a plurality of second chain pins, and the chain pins pass through the first through holes of a chain link and the second through holes of other chain links, so that the chain links arranged in the chain width direction are flexibly connected to each other in the chain length direction, wherein, The first chain pin fixed in the first through hole of one link and movably inserted in the second through hole of the other link, and the first chain pin movably inserted in the first through hole of one link and fixed The above-mentioned second chain pins in the second through holes of other chain links move relative to each other in rolling contact, so that the above-mentioned bending can be realized, and more than two kinds of combinations of the first chain pins and second chain pins are formed. Among them, the trajectories of the contact positions of the first chain pins and the second chain pins become circular involutes, and the base circle radii of the involutes are different, The aforementioned plurality of chain friction transmission members includes a plurality of types of chain friction transmission members having different rigidities with respect to forces in the chain width direction. 7. The power transmission chain according to claim 6, wherein all of the chain friction transmission members have substantially the same length in the longitudinal direction. 8. The power transmission chain according to any one of claims 6 or 7, characterized in that: the aforementioned plurality of chain friction transmission components include various chain friction components having different cross-sectional shapes or cross-sectional areas in the cross-section perpendicular to the width direction of the chain. Transmission parts. 9. The power transmission chain according to any one of claims 6 to 8, wherein the first chain pin or the second chain pin is a transmission chain pin also serving as a frictional transmission member of the chain. 10. The power transmission chain according to claim 9, characterized in that: the plurality of transmission chain pins include various transmission chain pins with different widths in the length direction of the chain on a section perpendicular to the length direction of the chain pins, and the aforementioned The plurality of links includes various links whose pitches differ. 11. A power transmission device comprising: a first pulley with a conical sheave surface; a second pulley with a conical sheave surface; a power transmission chain set between the first and second pulleys, The power transmission device is characterized by: The aforementioned power transmission chain is the power transmission chain according to any one of claims 1-10.

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