JPH0137356Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bicycle chain gear, and more particularly to a bicycle chain gear comprising a body and a tooth portion having a large number of teeth.

In general, this type of chain gear has a structure in which the body and teeth are rigid as a whole, so the drive torque from the pedals is transmitted as is without any buffering, resulting in poor pedal comfort. It was hot.

Therefore, the body, the teeth, and the elastic displacement part connecting these are first formed, and the body, the teeth, and the elastic displacement part are integrally molded with synthetic resin, and the driving torque is applied to the body and the teeth. We have proposed a system in which the transmission operation is performed while being buffered by the displacement of the elastic displacement section.

Incidentally, in this device, the elastic displacement portion is configured to be displaced by the drive torque and to come into pressure contact with the opposing portion when the torque value exceeds a certain value.

However, when the elastic displacement part is in pressure contact with the opposing part, the pressure contact parts slide against each other due to the elasticity of the elastic displacement part, causing a problem that a loud and unpleasant noise is generated. .

Therefore, as a result of various studies to solve the above problems, we found that the reason why the above-mentioned noise occurs is that the elastic displacement part that slides against each other and the opposing part are made of the same synthetic resin material. Because of this, when they slide together, they are heated and have a strong affinity for each other, making them easy to peck.
In other words, it was found that this was caused by poor slipperiness.

Therefore, the present invention focuses on a different material, such as metal, which has a greater sliding performance than the synthetic resin used for the elastic displacement part and its opposing part, and utilizes this performance of the different material. However, the above-mentioned problem was solved by providing a member made of the different materials on one of the elastic displacement portion and the opposing portion with which the displacement portion comes into pressure contact.

The object of the present invention is to transmit driving torque in a buffer manner by an elastic displacement section connecting a large number of teeth to a body, and to use the displacement operation of the elastic displacement section.
To provide a chain gear for a bicycle, in which opposing parts that are pressed against each other can always slide with good slippage, and generation of loud unpleasant noise when sliding in this manner can be suppressed to a minimum.

The structure of the present invention consists of a body, a tooth portion having a large number of teeth, and an elastic displacement portion disposed between the body and the tooth portion to connect the tooth portion to the body. and an elastic displacement part integrally molded from synthetic resin, wherein one of the opposing parts which slides in pressure contact with each other due to the displacement operation of the elastic displacement part, has a corresponding one of the parts against the synthetic resin. It is characterized by the provision of a pressure contact member made of a different material such as metal, which has greater sliding performance than synthetic resin.

Hereinafter, embodiments of the chain gear of the present invention will be described based on the drawings.

In the drawing, 1 is a body, 2 is a plurality of teeth 21
..., and 3 is a toothed portion 2 on the body 1.
The body 1, tooth portion 2, and elastic displacement portion 3 are integrally molded from synthetic resin, and each elastic displacement portion 3...
A displacement gap 4 is formed in the direction of displacement that allows the displacement operation by the drive torque of the displacement part 3, and the drive torque is applied between the body 1 and the tooth part 2 by the displacement of each elastic displacement part 3. It is as if the transmission is activated while being buffered.

Therefore, the gist of the present invention is that the elastic displacement portion 3
A pressure contact member 5 made of a different material such as a metal having a higher sliding performance than the synthetic resin is provided on one side of each of the opposing parts that slide in pressure contact with each other due to the displacement operation of the synthetic resin. That's what happened.

In the drawing, the tooth portion 2 is arranged on the outer circumferential side of the body 1 with a circumferential gap therebetween, and the elastic displacement portions 3 are moved around the body along the circumferential direction of the circumferential gap. Four cranks are arranged symmetrically with respect to the rotation center of the body 1 on both sides of the crank A provided in the body 1 in the arrangement direction. These elastic displacement parts 3 include first, second and third spring parts 31,
32 and 33, the first spring portion 31 extends from the outer circumferential wall of the body 1 to near the inner circumferential wall of the tooth portion 2, and the width becomes wider toward the base of the extension on both sides in the extending direction. It is formed in a circular arc shape, and the opposing side walls of the adjacent first spring portions 31, 31 are formed in a series as a whole in a substantially semicircular arc shape. Further, the second spring portion 32 is connected to the adjacent first spring portion 31,
A semicircular ring-shaped member is arranged along the semicircular side wall of 31, and one end of the member is connected to the first spring part 31.
The other end is connected to the inner circumferential wall of the toothed portion 2 in a manner such that it is supported on both sides. Further, the third spring portion 3
3, a substantially U-shaped member is arranged along the semicircular arc-shaped inner wall of the second spring section 32, and near the continuous portion of the second spring section 32 at the distal end edge of the first spring section 31. It is installed in a cantilevered manner.

In this way, the displacement gap 4 formed in the displacement direction of the elastic displacement section 3 has a semicircular arc shape between the series of side walls of the adjacent first spring sections 31, 31 and the second spring section 32. An inner gap 41 is formed between the second and third spring parts 32 and 33, and a substantially U-shaped spring gap 42 is formed between the second and third spring parts 32 and 33. An inter-spring gap 43 is formed. Further, the inner circumferential wall of the tooth portion 2 and the first
An outer gap 44 is formed between the tip of the spring portion 31 and the opposing side wall extending from the tip of the third spring portion 33 to the side edge of the tip via the continuous portion of the second and third spring portions 32 and 33. It is formed. One end of this outer gap 44 communicates with the spring gaps 43 and 44, and
The other end is the inner gap 4 in the adjacent elastic displacement part 3
It is connected to one end of 1.

In the elastic displacement section 3, the first
A contact surface 31a is formed at the free end side edge of the third spring section 33 at the tip of the spring section 31, and the contact surface 3
A contact surface 2a is formed on the inner circumferential wall of the toothed portion 2 facing 1a through the outer gap 44, while a free end portion of the third spring portion 33 and the second spring portion 32 of the toothed portion 2 are formed. Abutment surfaces 33a and 2b are formed at the portion facing the continuous base of the spring with the inter-spring gap 42 interposed therebetween.

Thus, the relative rotational direction of the body 1 with respect to the toothed portion 2 during driving is the rotational direction in which the tip of the first spring portion 31 in the elastic displacement portion 3 moves toward the tip of the third spring portion 33. That is, in FIG. 4, it is set in the clockwise direction indicated by the arrow.

When the tooth portion 2 and the body 1 are rotated relative to each other in this way, first the second spring portion 32 is rotated in the elastic displacement portion 3 so that both contact surfaces 33a and 2b are rotated by the spring constant of the spring portion 32. Until they come into contact, the springs are bent in the gap 42, and then, with the contact surfaces 33a, 2b in contact, the third and second spring parts 33, 32
is flexibly operated in the inter-spring gap 43 with a spring constant equal to the sum of the spring constants of the spring parts 33 and 32 until the contact surfaces 31a and 2a come into contact with each other. Further, in a state where the contact surfaces 33a, 2b and the contact surfaces 31a, 2a are in contact with each other, the third, second and first spring portions 33, 32, 31 are The inter-spring gap 43 and the inner gap 41 are caused to flex by a spring constant that is the sum of the constants.

The spring constants of each of the first to third spring parts 31...33 can be made to have arbitrary linear or nonlinear characteristics, and these characteristics may be the same or different in each elastic displacement part 3... It may be made into

Further, the elastic displacement portion 3... is connected to the contact surface 31 between the tip of the first spring portion 31 and the inner circumferential surface of the tooth portion 2 opposite to the tip surface via the outer gap 44.
b, 2c are provided, and when the rotational position is at an intermediate position in the vertical direction by driving and the tension of the chain B is applied to the teeth of the corresponding tooth part 2 as shown by the arrow in FIG. The spring portion 32 is flexibly operated in the inner gap 41 to close the body 1.
In contrast, the tooth portion 2 is moved toward the tension until the contact surfaces 31b and 2c come into contact with each other.

Next, a center hole 11 is provided in the center of the body 1.
An adapter 6 for attaching to the crankshaft C is buried in the center hole 11.
This adapter 6 has a mounting hole 61 in its center that is spline-fitted with the crankshaft C, and
A plurality of embedded members 62 for preventing rotation are provided which extend radially outward in the radial direction, and the embedded members 62...
A blocking piece 63 having the function of preventing rotation and preventing movement in the radial direction is attached to one side of the tip.

Then, as shown in FIG. 5, the crankshaft C is rotatably supported by the bottom bracket D, and the end of the crankshaft C is spline-fitted into the mounting hole 61 of the adapter 6 and penetrated outward. The boss part of the crankshaft C is spline-fitted to the end of the crankshaft C, and the adapter 6 is bent between the end face of the boss part and the opposite end face of the crankshaft C to connect the boss part and the crankshaft C. Fixing means such as bolts E
I'm trying to fix it.

Therefore, in the pressure contact member 5 and its mounting structure shown in the drawings, the contact surfaces 2a, 2c of the first spring portion 31 of the elastic displacement portion 3 correspond to the contact surfaces 31a, 31b on the inner circumferential surface of the tooth portion 2. A recessed portion 27 having a locking portion 27a for the pressure contact member 5 is formed across the pressure contact member 5, and the pressure contact member 5 is formed at a portion facing the free end portion of the third spring portion 33.
A deep and wide recess 28 is formed with a pair of locking parts 28a and 28b for the recess 27,
The inner and outer sides of 28 are opened at the inner and outer sides, and a side wall 29 is formed on the outer side to prevent the pressure contact member 5 from falling off toward the outside. In addition, what prevents the pressure contact member 5 from falling inward is as follows.
This is done by attaching an inner cover 7, which will be described later, to the inner surface of the toothed portion 2.

The pressure contact member 5 may be made of a metal such as stainless steel, aluminum alloy, etc. as a dissimilar material with good slip resistance when, for example, Jyuracon is used as the synthetic resin used for the body 1, the tooth portion 2, and the elastic displacement portion 3. A synthetic resin such as fluorine resin or nylon is used, and its outer shape is as shown in FIG. 4 and FIGS. 2
8 to the contact surface 2b opposite to the contact surface 33a of the third spring portion 33, and the locking portion 2 is formed at one end in the length direction.
A locking part 51 is formed in the middle in the longitudinal direction to lock in the locking part 7a and prevent the movement into the outer gap 44, and to lock in the pair of locking parts 28a and 28b in the longitudinal direction. Locking portions 52 and 53 are formed to prevent movement into the gap 44. At both ends in the length direction of this pressure contact member 5, from the inside of the tooth portion 2, the outer gap 44, the recess 2
The cutout portion 54 is formed to reduce the insertion resistance without getting caught when the materials are charged closely into the holes 7 and 28.

On the other hand, an outer cover 8 for concealing the elastic displacement section 3 is provided on the outside and inside of the elastic displacement section 3.
and the inner cover 7 are arranged, and one of the outer circumferential part and the inner circumferential part of these covers 8 and 7 is attached to the body 1.
At the same time, seal structures 91 and 92 are formed between the other member and the member facing the other member.

Regarding the outer and inner covers 8, 7 and their mounting structure shown in the drawings, a bulging portion 22 is formed on the outer side of the tooth portion 2 to bulge in the axial direction along the circumferential direction, and the outer periphery thereof is A plurality of gripping recesses 22a are formed along the circumferential direction on the surface for ease of gripping and weight reduction, and a mounting surface 23 for the outer cover 8 is formed on the outer surface. A mounting surface 24 of the inner cover 7 is formed on an inner surface corresponding to the mounting surface 23, and the mounting surface 24
A retaining wall 25 of the inner cover 7 is formed along the outer periphery of the inner cover 7, and a plurality of mounting holes 26 are formed in the circumferential direction between the mounting surfaces 23 and 24. and,
The outer cover 8 is made of synthetic resin such as ABS resin, and has a guide portion 81 for the tooth portion 2 formed on its outer circumference, and the mounting surface 2 formed on its inner circumference.
3, a sealing mounting surface 82 is formed over the entire circumference of the mounting surface 82, and penetrating members 83 for penetrating the mounting holes 26 are protruded from the mounting surface 82. A concealing portion 84 of the elastic displacement portion 3 is formed at the inner peripheral end thereof, and a flange 85 of the sealing structure 91 extending toward the body 1 is formed at the inner peripheral end thereof. The flange 12 of the seal structure 91 has a seal circumferential surface opposite to the seal circumferential surface of the flange 85.
are formed extending from the inner peripheral side of the body 1.

The inner cover 7 is made of a synthetic resin such as ABS resin, and has an outer circumferential portion sized to fit along the retaining wall 25, and an inner circumferential portion that extends over the entire circumference relative to the mounting surface 24. A seal structure 9 is formed, which forms a sealing mounting surface 71, forms a concealing portion 72 for the elastic displacement portion 3 on the inner peripheral side thereof, and further extends toward the body 1 at the inner peripheral end thereof.
2 seal portions 73 are formed.

Then, the outer cover 8 is applied to the mounting surface 23 and the penetrating members 83 are passed through the mounting holes 26, and the inner cover 7 is applied to the mounting holes 24 and the end faces of the penetrating members 83. Then, both covers 8 and 7 are pressed and welded together by ultrasonic processing. In addition to the contact portion between the end face of the penetrating member 83 and the inner cover 7, the welding portion may be selected from the contact portion between the covers 8, 7 and the mounting surfaces 23, 24, The contact portion may be selected such that the mounting hole 26 is brought into contact with the mounting hole 26 through a stepped portion and a tapered portion as shown in FIG. In addition to the above-mentioned ultrasonic processing,
Needless to say, the welding process may be performed by heating, and attachment means such as screws may be used.

Further, a seal structure 91 in the outer cover 8
may be provided for the boss portion of the crank A, the crankshaft C, and the adapter 6, and the seal structure 92 of the inner cover 7 may be provided for the adapter 6, the crankshaft C, and the bottom bracket D. It's okay.

Further, a guide portion 81 provided on the outer cover 8
is separated from the teeth 21 for a certain period of time by the bulging part 21 provided on the tooth part 2, and even if the tooth part 2 is bent with respect to the crankshaft due to a change in the chain line, the chain B will not touch the outer cover 8. This is done to avoid contact. In addition, the first spring portion 31 of the elastic displacement portion 3 in the drawings may be provided with a pattern such as a concave groove or a convex strip at a portion that moves relative to the tooth portion 2 to which the cover 8 is attached, or the pattern may be colored. In addition, the cover 8
Transparent means 86, 86, such as a through hole of a size matching the external shape of the identification means 13, or a lid that allows the inside to be seen through the through hole, are formed in a seal shape at a portion facing the identification means 13. When driving,
Through these transparent means 86, 86, the identification means 1
This makes it possible to visually see that the parts 3 operate as if they are hidden, and as a result, not only during normal operation, but also when displayed in a store, the body 1 and tooth part 2 are elastically moved through the elastic displacement part 3 when driven. This allows us to demonstrate that the product is in relative motion.

Therefore, the above configuration is assembled so as to be able to rotate integrally with the crankshaft C and crank A of the bicycle as shown in FIG. In addition, the driving torque causes the elastic displacement portion 3 to
... operates to displace within the displacement gap 4 toward the opposing portion, acting as if transmitting the driving torque to the tooth portion 2 while buffering it, and therefore, a soft stepping feeling is always obtained. It is.

Then, as described above, due to the increase in the driving torque, the elastic displacement portions 3... first move to the third spring portion 33.
The contact surface 33a of the first spring section 31 presses against the corresponding part of the contact surface 2b of the tooth section 2 on the pressure contact member 5, and then the contact surface 31a of the first spring section 31 contacts the corresponding section of the contact surface 2a of the tooth section 2 on the pressure contact member 5. As a result, the pressure contact portions slide against each other due to the elasticity of the elastic displacement portion 3.

However, one of the press-contact parts is made of the synthetic resin, while the other is made of a material different from the synthetic resin, and these materials have a greater slippage than the synthetic resin, so these press-contact parts do not slide against each other. The dynamic resistance is low, the amount of heat generated is low, and the entire sliding condition is reasonably smooth.Therefore, there is less wear on each other, and the generated sound volume can be minimized, and the sound quality is also improved. This makes it possible to prevent unpleasant noises from occurring as in the case of this condition.

On the other hand, each displacement gap 4 for the elastic displacement portion 3 is closely supported by the outer cover 8 and the inner cover 7 over the entire circumference of the tooth portion 2 on the radially outward side, and is closed to the outside air. On the other hand, the radially inward side is sealed from the outside air by the seal structures 91 and 92, and as a result, solid objects such as sand grains are prevented from entering the displacement gap 4. It is possible to reliably prevent the elastic displacement portion 3 from performing its original function, that is, to transmit the driving force between the tooth portion 2 and the body 1 in a buffer-like manner, and to ensure that the above function is maintained for a long time. It can be stably demonstrated over a period of time.

Further, since the outer cover 8 is provided with a see-through means 86 and the identification means 13 is provided on the first spring portion 31 inside the see-through means 86, each of the elastic displacement portions 3
When the displacing operation is performed, the identification means 13
The elastic displacement part 3 becomes hidden from view.
The operating status of the device can be determined visually.

Incidentally, in the above explanation, the pressure contact member 9 is a contact surface 31 of one of the first and second spring portions 31 and 32.
a, 33a, one set of contact surfaces 2a of the tooth portion 2,
2b, but it is also possible to form a continuous ring over the entire contact surfaces 2a, 2b of the tooth portion 2. It may be formed into a shape. Further, as shown in FIG. 8, a rod-shaped body may be attached without using a plate material. Further, the pressure contact member 5 can be provided at any arbitrary location on one of the opposing portions that slide in pressure contact with each other by the displacement operation of the elastic displacement portion 3.

Further, since it is difficult for solid objects to enter from the inside of the displacement gap 4, the inner cover 7 does not need to be used. Engagement means (not shown) capable of preventing the pressure contact member 5 from falling off inwardly
We will set up the following.

Further, in the above explanation, it is used on the front side, but it goes without saying that it can also be used on the rear side.

As described above, according to the present invention, driving torque is transmitted in a buffered manner by the elastic displacement section that connects a large number of tooth sections to the body, and the opposing sections that are in pressure contact with each other are moved by the displacement operation of the elastic displacement section. They can be slid with good slipperiness, suppressing wear of the mutual pressure contact parts, and minimizing the occurrence of unpleasant noises caused by sliding.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; Fig. 1 is a cross-sectional front view, Fig. 2 is a partially cut-away external view, Fig. 3 is an internal side view, and Fig. 4 is an internal side view of only the chain gear. , FIG. 5 is an explanatory diagram of the crank and its mounting state on the crankshaft, FIG. 6 is a partial cross-sectional view taken along the line X-X in FIG. 4, FIG. 7 is a partial cross-sectional view taken along the Y-Y line in FIG. 8, and FIG. FIG. 3 is a perspective view of a pressure contact member. 1...Body, 2...Teeth, 21...Teeth, 3...
...Elastic displacement part, 5... Pressing member.

Claims (1)

[Scope of utility model registration request] It consists of a body, a toothed part having a large number of teeth, and an elastic displacement part disposed between the body and the toothed part to connect the toothed part to the body. A bicycle chain gear integrally molded from a synthetic resin, wherein one of the opposing parts that press against and slide against each other due to the displacement operation of the elastic displacement part, is made of a synthetic resin. A chain gear for a bicycle, characterized in that it is provided with a pressure contact member made of different materials such as metals with high sliding performance.