JPH10110806A - Sprocket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To thin a sprocket and reduce its weight while keeping satisfactory meshing with a chain, and secure strength against twisting by forming a corrugated portion on an outer periphery of the sprocket which is waved in a widthwise direction along a circumference, and forming teeth on outer ends of at least tops of the corrugated portion. SOLUTION: A corrugated portion 2 which is waved in a widthwise direction with a specified cycle is formed on a sprocket 1 from its outer end to a center portion within substantially one third of a diameter in a circumferential direction. A tapered portion 4 from one top 3 to the adjacent top 3 of the corrugated portion 2 is spirally formed. A plurality of teeth 5 are formed on an outer periphery of the corrugated portion 2 such that an outer end of the top 3 is a tooth end and the way to the outer end of the tapered portion 4 is a tooth bottom, while a chamfered portion is formed on a top side of a leading end of the tooth 5. The sprocket 1, even having half witch as that of a conventional one, is always properly meshed with a chain. Half amount of material is enough to prepared the sprocket 1 compared to a conventional case.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sprocket of a wrapping transmission for transmitting power or the like via a chain.

[0002]

2. Description of the Related Art Generally, in a power transmission system of a motorcycle, a bicycle or various industrial machines, a wrapping transmission device using a chain and a sprocket is widely used. Regarding the shapes and sizes of chains and sprockets, JISB1801 and JISB1802
Are stipulated respectively. In the sprocket,
In order to reduce the amount of materials used to reduce the production cost, and in motorcycles and the like, to reduce the body weight,
In some cases, a plurality of lightening holes are formed in a predetermined arrangement to reduce the weight of the sprocket in order to improve the response during acceleration and the like. Also, the sprocket provided on the rear wheel side of the motorcycle is often exposed to the outside, and since the appearance of the motorcycle is greatly affected by the shape of the lightening hole, many proposals have been made regarding the shape and size of the lightening hole. I have.

[0003]

By providing the lightening holes as described above, the weight of the sprocket can be considerably reduced. However, in order to secure the strength and rigidity of the teeth, a lightening hole is formed at the outer peripheral end of the sprocket. Because of this, it was difficult to reduce the weight more than is currently being done. Moreover, in order to improve the responsiveness during acceleration, it is preferable to make the outer peripheral portion of the sprocket lightweight. However, as described above, the problem that the outer peripheral portion of the sprocket cannot be made sufficiently lightweight with the reduction hole is described above. There is also.

On the other hand, the chain has a structure in which two pin link plates and roller link plates arranged in parallel are alternately arranged and mechanically pin-connected to each other, so that an acceptable tensile strength is obtained. Has its own limitations,
If a thing narrower than the one currently used is used, a problem occurs in strength. On the other hand, sprockets do not have mechanical connection parts such as chains, and in recent years, various materials with excellent strength and rigidity have been proposed. Strength and rigidity are being obtained.

Therefore, it is conceivable to use a chain of a current size having sufficient strength and to make only the sprocket thin so as to reduce the overall weight. There is a concern that play may occur in the thickness direction of the sprocket, causing meshing not to be smooth and causing noise, sprockets and chains being unevenly worn, and sprockets and chains being twisted due to uneven loads. Is done.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the weight by forming a thin plate as a whole while maintaining a smooth meshing relationship with a chain, and to secure sufficient strength against torsion and to perform press molding. An object of the present invention is to provide a sprocket which can be easily manufactured and has an excellent design.

[0007]

According to a first aspect of the present invention, there is provided a sprocket, wherein at least an outer peripheral portion of the sprocket is formed with a waveform portion which oscillates in a thickness direction along a circumferential direction, and at least a top portion of the wave of the waveform portion is formed. The outer end is formed with teeth. Here, as described in claim 2, the pitch between the peaks in at least one wave of the waveform portion is set to a pitch different from the pitch between the peaks in other waves, and in this wave, the pitch between the outer end of the peak and the peak is different. Teeth may be formed at the outer end part of the slope part. The sprocket according to claim 3 is a sprocket in which at least an outer peripheral portion of the sprocket is formed with a corrugated portion in which thick portions and thin portions are alternately arranged in a circumferential direction, and teeth are formed at outer ends of the thick portion. is there. According to a fourth aspect of the present invention, at least an outer peripheral portion of the sprocket is formed with an annular corrugated portion that oscillates in a thickness direction along a radial direction, and teeth are formed on an outer peripheral portion of the corrugated portion.

[0008] In the sprocket according to any one of the first to third aspects of the present invention, as in the fifth aspect, the top of the wave of the waveform part is formed radially in the radial direction of the sprocket. As described in Item 6, the top of the wave of the corrugated portion is formed to be inclined with respect to the radial direction of the sprocket, and as in Claim 7, the top of the wave of the corrugated portion is formed with respect to the radial direction of the sprocket. It is a preferred embodiment to form it in a curved shape. The position where the corrugated portion is formed in the sprocket may be formed from the through hole formed in the center portion of the sprocket to the outer peripheral portion, as described in claim 8, or the outer peripheral portion of the sprocket may be formed as described in claim 9. It may be formed only in the vicinity. As described in claim 10,
The top of each wave may be formed flat, or the top of each wave may be formed in a bent shape. Also, the teeth of the sprocket may be formed in a flat plate shape. According to a thirteenth aspect, a reduction hole for reducing the weight of the sprocket may be formed. As the shape of the lightening hole, various shapes including a circular shape and an oval shape, as described in claims 14 to 15, and claim 1.
As described in 6, a reducing hole or the like that opens to the through hole can be adopted at the center of the sprocket.

It is preferable that a noise reducing means for reducing noise generated by the contact between the sprocket and the chain is provided. As the noise reduction means, a cushioning material made of an elastomer, a synthetic resin, or the like can be adopted. The noise reducing means may be provided at or near the tooth bottom of the sprocket as described in claim 20, or may be provided in a part or all of the grooves of the corrugated portion of the sprocket in a filling manner as described in claim 21. As described in Item 22, the sprocket can be provided so as to cover the top of the corrugated portion, or as described in Claim 23, it can be provided on both front and back surfaces or one surface of the sprocket. If the contact is made, noise can be effectively reduced, but the durability of the noise reduction means is reduced. Therefore, it is preferable that the noise reduction means is provided at a position as close as possible while not contacting the chain. As a method of fixing the noise reduction means to the sprocket, the sprocket is fixed with an adhesive as described in claim 24,
According to a twenty-fifth aspect, an insertion hole is formed in the corrugated portion of the sprocket and fixed through the insertion hole, or a fixing method using both the adhesive and the insertion hole is conceivable. Further, as described in claim 26, an annular elastomer may be used as the noise reducing means, and this elastomer may be alternately engaged with a plurality of teeth of the sprocket and positioned and fixed near the tooth bottom of the sprocket.

[0010]

In the sprocket according to the first aspect, at least the outer peripheral portion of the sprocket is formed with a corrugated portion which oscillates in the thickness direction along the circumferential direction, and has teeth at the outer end of the top of the corrugated portion. Because it is formed, the teeth of the sprocket will alternately mesh with the roller of the chain at one end and the other end of the roller, and the play in the thickness direction of the sprocket between the sprocket and the chain is always appropriate. State is maintained. In other words, by forming a corrugated portion at least on the outer peripheral portion of the sprocket, even if the sprocket is made thin according to the strength of the chain, the apparent thickness of the teeth of the sprocket meshing with the chain will be the appropriate tooth thickness. Therefore, the meshing relationship between the sprocket and the chain is maintained in an appropriate state. In addition, by forming a corrugated portion on the sprocket, the strength and rigidity of the entire sprocket against torsion are increased, and since the sprocket rotates, the corrugated portion cuts off the air, so that the temperature rise of the sprocket is suppressed. Become. Furthermore, muddy water and the like attached to the outer surface during the use of the sprocket move to the meshing portion between the sprocket and the chain due to centrifugal force due to the rotation of the sprocket, but at least the corrugated portion is formed at the outer peripheral portion of the sprocket. As a result, muddy water and the like are efficiently discharged to the outside along the grooves of the corrugated portion, and are hardly caught between the sprocket and the chain. Here, when configured as in claim 2, it is possible to produce an odd-numbered sprocket by setting an odd number of waves in which the pitch between the peaks is set to a different pitch from the pitch between the other peaks. It becomes possible.

In the sprocket according to the third aspect,
At least on the outer peripheral portion of the sprocket, a corrugated portion in which thick portions and thin portions are alternately arranged in the circumferential direction is formed, and teeth are formed on the outer end portion of the thick portion, so that the sprocket between the sprocket and the chain The play in the thickness direction is maintained in an appropriate state. In other words, while maintaining the meshing relationship between the sprocket and the chain in the proper state by the thick part,
The thin portion makes it possible to reduce the weight of the sprocket. Moreover, by forming the thick portions and the thin portions alternately in the circumferential direction, it is possible to ensure sufficient strength and rigidity against twisting of the entire sprocket. Further, similarly to the first aspect, muddy water and the like are efficiently discharged to the outside along the grooves of the corrugated portion, and are hardly caught between the sprocket and the chain.

In the sprocket according to claim 4,
At least on the outer peripheral portion of the sprocket, an annular corrugated portion that oscillates in the thickness direction along the radial direction is formed, and teeth are formed on the outer peripheral portion of the corrugated portion, so that the sprocket in the thickness direction between the sprocket and the chain Play is maintained in the proper state. In other words, by forming a corrugated portion at least on the outer peripheral portion of the sprocket, even if the sprocket is made thin according to the strength of the chain, the distance between the tops of the waves in the thickness direction of each tooth is the same as that of the appropriate tooth Therefore, the meshing relationship between the sprocket and the chain is maintained in an appropriate state. In addition, by forming a corrugated portion on the sprocket, the strength and rigidity of the entire sprocket against torsion are increased, and since the sprocket rotates, the corrugated portion cuts off the air, so that the temperature rise of the sprocket is suppressed. Become. Further, muddy water and the like adhering to the outer surface during use of the sprocket move to the meshing portion between the sprocket and the chain due to centrifugal force due to the rotation of the sprocket, but the muddy water once moves into the groove of the corrugated portion. Is discharged to the outside, so that it is hardly caught between the sprocket and the chain.

According to the fifth and sixth aspects of the present invention, when the peak of the wave of the corrugated portion is formed in a radial, inclined or curved shape with respect to the radial direction of the sprocket, the corrugated portion itself acts as a design characterizing the appearance of the sprocket. And the appearance of the sprocket is improved. Further, when the corrugated portion is formed from the through hole at the center of the sprocket to the outer peripheral portion, the area of the corrugated portion occupying the entire sprocket is increased, and the appearance of the corrugated portion is further emphasized. Further, when the corrugated portion is formed only in the vicinity of the outer peripheral portion of the sprocket, it is possible to reduce air resistance during rotation of the sprocket as much as possible.

When the lightening holes are formed, the weight of the sprocket can be further reduced. Further, when a circular or oval-shaped lightening hole is formed as a lightening hole according to a certain rule, the lightening hole itself acts as a design characterizing the appearance of the sprocket, and the appearance of the sprocket is improved.

If the sprocket is provided with a noise reducing means, the noise generated by the contact between the sprocket and the chain can be reduced, and the quietness at the time of driving the chain can be improved. .
In the case where a cushioning material made of an elastomer, a synthetic resin, or the like is used as the noise reduction means, the sprocket and the chain come into contact with each other by elastically deforming the cushioning material. Vibration energy and collision energy are absorbed, and noise during chain driving is reduced.

In the case where the noise reducing means is provided at or near the tooth bottom of the sprocket,
It is possible to dispose the noise reducing means close to the chain meshing with the sprocket, and it is possible to efficiently reduce noise when driving the chain. When the noise reducing means is provided for the corrugated portion as described in claims 21 and 22, the noise reducing means filled in the groove of the corrugated portion functions as an anchor, so that the coupling strength of the noise reducing means to the sprocket is increased. . The noise reduction means can be fixed to the sprocket with an adhesive as described in claim 24, but as described in claim 25, an insertion hole is formed in a corrugated portion of the sprocket, and the insertion hole is formed. By fixing through the sprocket, not only the mounting strength of the noise reduction means to the sprocket can be further improved, but also the noise reduction effect is excellent. According to a twenty-sixth aspect of the present invention, an annular elastomer is used as the noise reducing means, and this elastomer is alternately engaged with a plurality of teeth of the sprocket and positioned and fixed near the sprocket tooth bottom. The reduction means can be easily assembled.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. Sprocket 1 shown in FIGS.
Is manufactured by press-forming a disk-shaped metal plate-shaped member, and the plate thickness of each part is set to be substantially the same. However, it can also be manufactured by casting or the like. Sprocket 1
In the range of about one-third of the radius from the outer end to the center of the wavy part, a wavy part 2 that oscillates in the thickness direction at a constant period in the circumferential direction is formed in a bent shape. Top 3 and top 3
The inclined portions 4 reaching the adjacent top portions 3 are arranged radially. On the outer peripheral portion of the corrugated portion 2, the outer end of the top portion 3 becomes the tooth tip 3a, and the middle of the outer end of the inclined portion 4 is the tooth bottom 4a.
A plurality of teeth 5 are formed such that a chamfered portion 5 a is formed on the top side of the tip of the tooth 5. If the thickness T1 of the sprocket 1 is 4/5 or more of the distance T2 in the thickness direction of the root of the adjacent tooth 5, the advantage of weight reduction cannot be sufficiently obtained, and if it is 1/5 or less, the strength cannot be sufficiently secured. So
It is set to 4/5 to 1/5. However, it may be set to 4/5 to 1/10 if the strength permits. In the drawing, it is set to about １ ／ times, and when two adjacent teeth 5 are virtually shifted in the circumferential direction and superimposed, the configuration is such that the cross-sectional shape of one tooth of a normal sprocket is the same. ing.

A through hole 6 is formed at the center of the sprocket 1, and a flat mounting portion 7 is formed between the corrugated portion 2 of the sprocket 1 and the through hole 6, and at a radially intermediate portion of the mounting portion 7. Four mounting holes 8 are formed at regular intervals.
For example, in the sprocket 1 of a motorcycle, the sprocket 1 is inserted through the rotating shaft of the rear wheel, and the mounting portion 7 is fixed to the flange portion of the rotating shaft with four bolts, and is mounted on the rotating shaft. However, the number of the mounting holes 8 formed in the mounting portion 7 of the sprocket 1 can be arbitrarily set, and for example, 6, 5, 3, 8, etc. may be provided. The center of the amplitude of the corrugated portion 2 is arranged on the same plane as the center of the mounting portion 7 in the thickness direction. However, it is not always necessary to arrange them on the same plane. For example, it is also possible to set so that one surface of the mounting portion 7 and one top surface of the corrugated portion 2 are arranged on the same plane. .

Next, the operation and effect of the sprocket 1 will be described. As shown in FIG. 5, the chain 10 is stretched with respect to the sprocket 1 such that the teeth 5 alternately mesh with the roller 11 at one end and the other end of the roller 11. For this reason, the plurality of teeth 5
In the state where the sprocket 1 is meshed with the sprocket 1, an appropriate clearance is formed between the teeth 5 of the sprocket 1 and the roller link plate 12 and the pin link plate 13, and the meshing relationship between the sprocket 1 and the chain 10 is always maintained in an appropriate state. become. As described above, even if the thickness of the sprocket 1 is set to about 1/2 of the thickness of the normal sprocket 1, the sprocket 1 always meshes with the chain 10 in an appropriate state. Even without this, the amount of material used for the sprocket 1 can be set to about ２. Further, by forming the outer peripheral portion of the sprocket 1 in a wavy shape, the strength and rigidity of the entire sprocket 1 against twisting can be increased. Further, the muddy water and the like adhering to the sprocket 1 move along the groove 2a formed on the concave side of the top 3 of each wave of the corrugated portion 2 and are smoothly discharged to the outside. It is possible to prevent the sprocket 1 and the chain 10 from being damaged due to being caught between the shaft 10 and the chain 10.

Next, another embodiment in which the structure of the sprocket 1 is partially changed will be described. The same members as those in the above embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. (1) The corrugated portion 2A may be formed in a portion extending from the outer peripheral end to the through hole 6 as in the sprocket 1A shown in FIG. 6, or only in the vicinity of the outer periphery as in the sprocket 1B shown in FIG. The corrugated portion 2B may be formed. (2) In the sprocket 1B, as shown in FIG.
As shown in FIG. 9, four or eight circular relief holes 20 are formed, as shown in FIG. 10, four oval relief holes 21 are formed, or as shown in FIG. Four cutout reducing holes 22 extending from the hole 6 may be formed, or any other number of reducing holes having various shapes may be formed to further reduce the weight of the sprocket 1B. Although not shown, in the sprocket 1, the corrugated portions 2 are formed so as not to reduce the strength of the teeth 5.
The sprocket 1A may be formed with a circular, oval, cut-out, or other various shape reducing hole.

(3) In the corrugated portion 2 of the sprocket 1, the top portion 3 is formed radially. However, like the corrugated portion 2C of the sprocket 1C shown in FIG. 12, the top portion 3C is formed inclined with respect to the radial direction. You may. In addition, sprocket 1
Also in A and 1B, the top part can be formed in an inclined shape like the sprocket 1C. Further, in the corrugated portion 2B of the sprocket 1B, the top portion 3 is formed radially, but the top portion 3D may be formed in a curved shape like the corrugated portion 2D of the sprocket 1D shown in FIG. The sprockets 1 and 1A can also be formed with a curved top 3 similarly to the sprocket 1D. (4) In the sprockets 1 and 1A to 1D, the top 3 is formed flat, but may be formed in a bent shape like a top 3E shown in FIG. 14 or as shown in a top 3F shown in FIG.
The vicinity of the top 3 may be formed flat so that the teeth 5 become flat. Further, the period of the waves of the corrugated portions 2 and 2A to 2C may be lengthened, and the teeth 5 may be formed at the outer end portion in the middle of the inclined portion 4. Further, in the case of the configuration as shown in FIG.
May be formed.

(5) Since the waveforms of the sprockets 1, 1A to 1D are made to oscillate at a constant period, the sprockets 1, 1A to 1D all have even teeth.
As shown in the sprocket 1G, the pitch between the tops 3 in at least one wave of the corrugated portion 2 is twice the pitch P1 between the other tops 3, that is, the top 3 is formed with a pitch of one cycle. Is also good. In this wave, the teeth 5 are formed at the outer end of the top 3 and the slope 4G between the tops 3 is formed.
A tooth 5G is formed at an outer end part in the middle of the above. If the number of inclined portions 4G is even, the sprocket has even teeth. If the number is odd, the sprocket has odd teeth. However, when a plurality of inclined portions 4G are provided, it is preferable to provide them at regular intervals on the circumference in order to improve the balance of the sprocket 1G. Also, in the sprockets 1A to 1D, similarly to the sprocket 1G, at least one wave crest is provided with a period of one cycle, and teeth are formed at the outer end part of the slope between the crests. By making the number of inclined portions odd, it is possible to manufacture an odd-numbered tooth sprocket. (6) Like the sprocket 31 shown in FIGS. 19 and 20, at least at the outer peripheral portion of the sprocket 31, an annular corrugated portion 32 is formed, which has a constant period in the radial direction and oscillates in the thickness direction. The teeth 35 may be formed in the portion.
In this sprocket 31, as shown in FIG. 21, by positioning two adjacent tops 33 of the corrugated portion 32 formed on the teeth 35 between the opposed roller link plates 12, the sprocket 31 and the chain 10 The meshing relationship is maintained in an appropriate state. In addition, the waveform part 3
2 can be set arbitrarily as long as the range includes the outer edge of the sprocket 31.

(7) Like a sprocket 41 shown in FIGS. 22 and 23, a wave portion in which thick portions 42 and thin portions 43 are alternately arranged at regular intervals in the circumferential direction at least on the outer peripheral portion of the sprocket 41. 46 may be formed, and the teeth 45 may be formed at the outer end of the thick portion 42. This sprocket 41
In this case, as shown in FIG. 24, the teeth 45 formed on the thick portion 42 of the sprocket 41 mesh over substantially the entire length of the rollers 11 of the chain 10 similarly to the teeth of a normal sprocket. , The meshing relationship between the sprocket 41 and the chain 10 is maintained in an appropriate state. In addition, as shown in FIG. 25, a corrugated portion 46A having a corrugated thin portion 43A may be formed as a corrugated portion. Also in this sprocket 41, similarly to the sprockets 1C and 1D, the corrugated portion 46 is formed.
The thick part 42 of A may be formed in an inclined shape or a curved shape with respect to the radial direction. Further, the formation range of the corrugated portion 46A can be arbitrarily set as long as the range includes the outer edge of the sprocket 41.

Incidentally, the sprocket of each of the above embodiments may be provided with a noise reducing means for reducing noise generated by contact with the chain. For example, FIG.
26, an annular cushioning member 50 made of flexible and elastic synthetic rubber or synthetic resin may be arranged around the sprocket 1 shown in FIG. In this case, the cushioning material 50 is alternately engaged with the plurality of teeth 5 of the sprocket 1, is disposed along the outer peripheral portion of the sprocket 1, and is fixed to the sprocket 1 with an adhesive. Since the cushioning member 50 is arranged in the vicinity of the tooth bottom 4a in this manner, the noise generated by the contact between the sprocket 1 and the chain is reduced when the chain roller 11 hits the cushioning member 50 when the chain and the sprocket engage.

In the example shown in FIG. 26, the cushioning material 50 is formed to have a uniform cross-sectional shape at each part in the circumferential direction.
As shown in (5), a concave portion 52 that fits into the teeth 5 may be formed in a portion of the cushioning material 50 that contacts the teeth 5. Forming the concave portion 52 in this way is preferable in improving the durability of the cushioning material 50 because the cushioning material 50 can be arranged on the outer peripheral portion of the sprocket 1 without substantially bending. Furthermore, if the recess 52 is fitted into the base end of the tooth 5 without any gap,
Foreign matter can be prevented from entering between the sprocket 1 and the cushioning material 50. Also, by forming the cushioning material 50 formed in an annular shape into a waveform according to the teeth 5 formed in the waveform,
The cushioning member 50 can be attached to the sprocket 1 without forming a gap between the sprocket 1 and the teeth 5.

FIGS. 26 and 27 show an example in which the cushioning member 50 is formed in an annular shape. However, as shown in FIG. 28, the cushioning member 54 may be individually attached to the tooth bottom 4a of the sprocket 1. Further, the cushioning member 54 may be extended toward the groove 2a of the corrugated portion 2 so as to increase the bonding strength between the sprocket 1 and the cushioning member 54.

The cushioning members 50, 54 shown in FIGS.
Are arranged so as to be in contact with the chain, so that noise during driving of the chain can be effectively reduced. However, since the durability of the cushioning members 50 and 54 may decrease, there is a problem as follows. May be configured. That is, FIG.
9. As shown in FIG. 30, a cushioning material 60 may be provided in the groove 2a of each wave of the corrugated portion 2 of the sprocket 1 in a filling shape, and the cushioning material 60 may be arranged close to at least so as not to contact the chain 10. . In this case, the cushioning material 60 can be fixed to the sprocket 1 only with an adhesive, but as shown in FIG. 30, an insertion hole 61 is formed in each top 3 of the corrugated portion 2 and the insertion hole 61 is formed. Is also filled with the cushioning material 60 to form the connecting portion 62, and the sprocket 1
May be connected to each other, and the cushioning material 60 may be fixed to the sprocket 1. When the cushioning member 60 does not protrude outward in the thickness direction from the top 3 of the corrugated portion 2, an insertion hole is formed in the inclined portion 4 to connect and fix the cushioning member 60 on the front and back. May be.

As shown in FIGS. 31 and 32, the outer edge of the cushioning member 60 may be arranged at the same position as the outer edge of the tooth 5 or a position slightly inside the outer edge of the tooth 5. However, the cushioning material 60 is configured so as not to protrude outward in the thickness direction from the top 3 of the corrugated portion 2 at least at the position where the cushioning material 60 meshes with the chain 10. With this configuration, it is possible to arrange the cushioning material 60 near the source of noise while avoiding the cushioning material 60 from contacting the chain 10. Therefore, while ensuring the durability of the cushioning material 60,
Noise can be more effectively prevented. Although the buffer material 60 is provided in all the grooves 2a in a filled state, the buffer material 60 may be provided in some of the grooves 2a, for example, every other one or two grooves 2a.
Further, the cushioning material 60 may be provided only on one surface side of the sprocket. Further, when the corrugated portion 2 is formed only on the outer peripheral portion of the sprocket 1B as in the sprocket 1B shown in FIG. 7, the cushioning material 60 is extended toward the mounting portion 7 so that the insertion hole formed in the mounting portion 7 is formed. The front and back cushioning members 60 may be connected through the intermediary. Furthermore, the noise reduction means having such a configuration can be provided in the same manner for the sprocket of each of the above-described embodiments.

[0029]

According to the sprocket according to the first aspect,
The sprocket and the chain mesh with a simple structure that can be easily manufactured by press molding or casting, by forming a corrugated part at least on the outer peripheral part of the sprocket and forming teeth at the outer end of the top part of the wave of the corrugated part. While maintaining proper relationships,
The weight of the sprocket can be easily reduced by configuring the sprocket to have a thickness corresponding to the strength of the chain. In addition, by forming the corrugated portion at least on the outer peripheral portion of the sprocket, it is possible to sufficiently secure the strength and rigidity of the entire sprocket against twisting. In addition, since the sprocket is efficiently cooled by cutting the air by the corrugated portion, thermal deformation of the sprocket can be prevented. Furthermore, since muddy water and the like attached to the sprocket are smoothly discharged to the outside without being caught between the sprocket and the chain,
Sprockets and chains can be prevented from being damaged. Further, when configured as described in claim 2,
It is possible to produce an odd-numbered sprocket.

According to the sprocket according to the third aspect, the thick portion and the thin portion are formed alternately in the circumferential direction at least on the outer peripheral portion of the sprocket, and teeth are formed on the outer end portion of the thick portion. With a simple structure that can be easily manufactured by forging or casting, it is possible to easily reduce the weight of the sprocket while properly maintaining the meshing relationship between the sprocket and the chain. Further, by forming the thick portions and the thin portions alternately at regular intervals in the circumferential direction, it is possible to sufficiently secure the strength and rigidity of the entire sprocket against twisting. Further, similarly to the first aspect, it is possible to smoothly discharge the muddy water and the like attached to the sprocket to the outside, thereby preventing the sprocket and the chain from being damaged.

According to the sprocket according to the fourth aspect, the corrugated portion is formed on at least the outer peripheral portion of the sprocket, and the teeth are formed on the outer peripheral portion of the corrugated portion. Thus, while properly maintaining the meshing relationship between the sprocket and the chain, it is possible to easily reduce the weight by configuring the sprocket to have a thickness corresponding to the strength of the chain. In addition, by forming the corrugated portion at least on the outer peripheral portion of the sprocket, it is possible to sufficiently secure the strength and rigidity of the entire sprocket against twisting. Further, similarly to the first aspect, it is possible to smoothly discharge the muddy water and the like attached to the sprocket to the outside, thereby preventing the sprocket and the chain from being damaged.

According to the fifth and sixth aspects,
The corrugations themselves act as a design that characterizes the appearance of the sprocket, and the appearance of the sprocket is improved. According to the structure described in claim 8, the area of the corrugated portion occupying the entire sprocket is increased, and the appearance of the corrugated portion can be further emphasized. Further, according to the ninth aspect, it is possible to minimize air resistance during rotation of the sprocket. According to the structure described in claims 13 to 16, the weight of the sprocket can be further reduced by the reduction hole. Further, when a circular or oval-shaped lightening hole is formed as a lightening hole according to a certain rule, the lightening hole itself acts as a design characterizing the appearance of the sprocket, and the appearance of the sprocket is improved. According to the configuration described in claims 17 to 26, noise generated by the contact between the sprocket and the chain can be reduced by the noise reduction means, and the quietness at the time of driving the chain can be improved.

With this configuration, the noise reduction means can be arranged as close as possible to the chain meshing with the sprocket, and noise during driving of the chain can be reduced efficiently. According to the structure of claims 21 and 22, it is possible to improve the coupling strength of the noise reduction means to the sprocket by utilizing the groove of the corrugated portion. With this configuration, the noise reduction unit can be efficiently assembled to the sprocket by alternately engaging the annular elastomer with the plurality of teeth of the sprocket.

[Brief description of the drawings]

FIG. 1 is a front view of a sprocket of the present invention.

FIG. 2 is an exploded view of the teeth of the sprocket.

FIG. 3 is a sectional view taken along line III-III of FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV of FIG.

FIG. 5 is an explanatory view showing a meshing state with a chain.

FIG. 6 is a front view of a sprocket according to another embodiment.

FIG. 7 is a front view of a sprocket according to another embodiment.

FIG. 8 is a front view of a sprocket according to another embodiment.

FIG. 9 is a front view of a sprocket according to another embodiment.

FIG. 10 is a front view of a sprocket according to another embodiment.

FIG. 11 is a front view of a sprocket according to another embodiment.

FIG. 12 is a front view of a sprocket according to another embodiment.

FIG. 13 is a front view of a sprocket according to another embodiment.

FIG. 14 is a view corresponding to FIG. 3 of a sprocket according to another embodiment.

FIG. 15 is a view corresponding to FIG. 3 of a sprocket according to another embodiment.

FIG. 16 is a front view of a sprocket according to another embodiment.

FIG. 17 is an exploded view of the teeth of the sprocket.

FIG. 18 is a view of the same sprocket as in FIG. 3;

FIG. 19 is a front view of a sprocket according to another embodiment.

20 is a sectional view taken along line XX-XX in FIG. 19;

FIG. 21 is an explanatory view showing a meshing relationship between the sprocket and a chain.

FIG. 22 is a front view of a sprocket according to another embodiment.

FIG. 23 is a view showing the same sprocket as FIG. 3;

FIG. 24 is an explanatory view showing the meshing relationship between the sprocket and a chain.

FIG. 25 is a view corresponding to FIG. 3 of a sprocket according to another embodiment.

FIG. 26 is a front view of a sprocket to which noise reducing means is attached.

FIG. 27 is a side view of a sprocket to which noise reducing means of another configuration is assembled.

FIG. 28 is a front view of a sprocket to which a noise reduction unit having another configuration is assembled.

FIG. 29 is a front view of a sprocket to which a noise reduction unit having another configuration is assembled.

FIG. 30 is a vertical cross-sectional view of a sprocket to which the noise reduction unit is attached.

FIG. 31 is a front view of a sprocket to which noise reducing means of another configuration is assembled.

FIG. 32 is a vertical cross-sectional view of a sprocket to which the noise reduction unit is attached.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 sprocket 2 corrugated portion 2a groove 3 top 3a tooth tip 4 inclined portion 4a tooth bottom 5 tooth 5a chamfered portion 6 through hole 7 mounting portion 8 mounting hole 10 chain 11 roller 12 roller link plate 13 pin link plate 1A sprocket 2A corrugated portion 1B Sprocket 2B corrugated part 20 lightening hole 21 lightening hole 22 lightening hole 1C sprocket 2C wave part 3C top part 1D sprocket 2D wave part 3D top part 3E top part 3F top part 1G sprocket 4G slope part 5G tooth 31 sprocket 32 wave part 35 wave part 33 Thick part 43 Thin part 45 Tooth 46 Wave part 46A Wave part 43A Thin part 50 Buffer material 52 Depression 54 Buffer material 60 Buffer material 61 Insertion hole 62 Connecting part

Claims (26)

[Claims] 1. A sprocket in which at least an outer peripheral portion of a sprocket is formed with a corrugated portion that oscillates in a thickness direction along a circumferential direction, and teeth are formed on at least an outer end of a top portion of the wave of the corrugated portion. 2. A pitch between the peaks of at least one wave of the corrugated portion is set to a pitch different from a pitch between peaks of other waves, and in this wave, an outer end portion of the peak and a middle portion of a slope between the peaks are set. The sprocket according to claim 1, wherein teeth are formed at an outer end portion. 3. A sprocket in which a wave portion in which thick portions and thin portions are alternately arranged in a circumferential direction is formed at least on an outer peripheral portion of the sprocket, and teeth are formed on an outer end portion of the thick portion. 4. A sprocket in which at least an outer peripheral portion of a sprocket is formed with an annular corrugated portion that oscillates in a thickness direction along a radial direction, and teeth are formed on an outer peripheral portion of the corrugated portion. 5. The sprocket according to claim 1, wherein the top of the wave of the corrugated portion is formed radially in the radial direction of the sprocket. 6. The sprocket according to any one of claims 1 to 3, wherein a top of the wave of the corrugated portion is formed to be inclined with respect to a radial direction of the sprocket.
The sprocket according to the item. 7. The sprocket according to claim 1, wherein a top of the wave of the corrugated portion is formed in a curved shape with respect to a radial direction of the sprocket.
The sprocket according to the item. 8. The sprocket according to claim 1, wherein a through hole is formed in a central portion of the sprocket, and a corrugated portion is formed from the through hole to an outer peripheral portion. 9. The sprocket according to claim 1, wherein the corrugated portion is formed only near the outer periphery of the sprocket. 10. The method according to claim 1, wherein the top of each wave is formed flat.
The sprocket according to any one of claims 1 to 9, wherein 11. The sprocket according to claim 1, wherein the top of each wave is formed in a bent shape. 12. The sprocket according to claim 1, wherein the teeth of the sprocket are formed in a flat plate shape. 13. The sprocket according to claim 1, wherein a reduction hole is formed in the sprocket to reduce its weight. 14. The sprocket according to claim 13, wherein a circular opening is formed as the reduction hole. 15. The sprocket according to claim 13, wherein an oval opening is formed as the lightening hole. 16. The sprocket according to claim 13, wherein a through hole is formed in a central portion of the sprocket, and a reduction hole that opens to the through hole is formed. 17. The sprocket according to claim 1, further comprising noise reduction means for reducing noise generated by contact between the sprocket and the chain. 18. The sprocket according to claim 17, wherein a buffer member is attached to the sprocket as the noise reduction means. 19. The sprocket according to claim 18, wherein an elastomer is attached to the sprocket as the noise reduction means. 20. The sprocket according to claim 17, wherein the noise reducing means is provided at or near the tooth bottom of the sprocket. 21. The sprocket is provided with a noise reducing means in a part or all of the grooves of the sprocket in a filling manner.
The sprocket according to any one of claims 0. 22. The sprocket according to claim 21, wherein the noise reducing means is provided so as to cover the top of the corrugated portion of the sprocket. 23. The sprocket according to claim 17, wherein the noise reducing means is provided on both front and back surfaces or one surface of the sprocket. 24. The sprocket according to claim 17, wherein the noise reducing means is fixed to the sprocket with an adhesive. 25. The sprocket according to claim 17, wherein an insertion hole is formed in a corrugated portion of the sprocket, and the noise reduction means is fixed to the sprocket via the insertion hole. 26. The sprocket according to claim 17, wherein an annular elastomer is used as the noise reducing means, and the elastomer is alternately engaged with a plurality of teeth of the sprocket, and is positioned and fixed near the tooth bottom of the sprocket.