JP2004168238A - Belt power transmitting device with automatic tension adjusting mechanism for bicycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt power transmitting device of good design and appearance, capable of resolving the complexity of a structure, remarkably reducing the cost, and achieving the characteristics such as maintenance free, silence and light transmitting performance. <P>SOLUTION: This belt power transmitting device is composed of a crank disc 2, a crank pulley main body 3a freely fitted to the crank disc 2 to be engaged and supported, and a driven part 3 of a lid body 3b of the crank pulley main body. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt power transmission device having an automatic tension adjusting mechanism for a bicycle that automatically adjusts belt tension in accordance with a stepping force applied to a crank.
[0002]
[Prior art]
Conventionally, as disclosed in Japanese Patent Publication No. 7-54136, the present applicant has proposed a belt power transmission device with an automatic tension adjusting mechanism for automatically adjusting the belt tension according to the stepping force applied to a crank. ing.
[0003]
[Problems to be solved by the invention]
Japanese Patent Publication No. 7-54136 proposed by the present applicant discloses an annular driven wheel 31 having endless outer teeth 4 on an outer peripheral end face, as shown in FIG. And a drive disk 35 integrally having a drive shaft 36 at the center located at the inner peripheral side of the annular driven wheel 31, and a drive shaft 36 of the drive disk 35 at the center on both side surfaces of the annular driven wheel 31. Both side plates 38, 38 having windows 39, 39 for penetrating and integrally attached to the annular driven wheel 31 to cover both side surfaces of the annular driven wheel 31, and a side plate cover 41 outside the both side plates 38, 38 , 41 and a toothed belt (not shown) wound between the annular driven wheel 31 and a power transmission pulley (not shown), and the drive disk 35 is equally spaced around a drive shaft 36. In addition to having a plurality of bushes 37, 37 projecting in the side direction, the side plates 38, 38 are equidistant from the center thereof and project from both sides of the drive disk 35. Bush windows 40, 40 having an inner diameter larger than the diameter of the bushes 37, 37 are provided at positions corresponding to the bushes 37, 37, and the drive disk 35 is attached to the annular driven wheel 31 with the bushes 37, 37 loosely fitted. The belt-type power transmission device is characterized in that it is loosely fitted on the inner peripheral side of the belt, so it is balanced evenly to the left and right, and has excellent transmission characteristics, but the structure is complicated, the number of components is large, and the cost is high. Did not escape.
[0004]
The present invention eliminates the complexity of such a structure, achieves a significant reduction in cost, and provides a number of features such as free maintenance, quietness and light transmission that are inherent characteristics of the belt drive device. The purpose of the present invention is to provide a device having an excellent appearance with excellent characteristics.
[0005]
[Means for Solving the Problems]
A belt power transmission device with an automatic tension adjusting mechanism for a bicycle, comprising a crank disk, a crank pulley body which is loosely fitted to the crank disk, and is engaged and supported, and a driven portion of a lid thereof.
[0006]
The crank disk is formed of a crank disk main body and a crank arm that is integrally fixed to a side surface of the crank disk. The crank disk main body is formed on a surface opposite to a mounting surface of the crank arm, concentrically with an axis of a fixed portion of the crank arm, and The required number of circumferential row drive pins may be provided at equal intervals from each other.
[0007]
The crank pulley body of the driven portion has a circumferential substrate portion formed on one side, an outer diameter edge formed on one outer rim portion, and a tooth portion meshing with a toothed belt on the inner surface side, A number of loose fitting receiving holes and a body mounting hole for the lid body corresponding to the number of the circumferential row drive pins of the crank disk are formed on the inner diameter side of the tooth portion, and the crank shaft is loosened at the center of the circumferential substrate portion. It is good also as what is provided with the main body crankshaft loose fitting hole which fits.
[0008]
The crank pulley body of the driven portion has a circumferential substrate portion formed on one side, an outer diameter edge formed on one outer rim portion, and a tooth portion meshing with a toothed belt on the inner surface side, A bearing cylinder portion forming a number of loose fitting receiving holes corresponding to the number of the circumferential row drive pins of the crank disk on an inner diameter side of the tooth portion, and a support cylinder portion forming a main body mounting hole with the lid are raised. It is also possible to provide a main body crankshaft loose fitting hole for loosely fitting the crankshaft at the center of the circumferential substrate portion.
[0009]
The crank pulley body of the driven portion may be formed by inserting a wear-resistant bush into each bearing cylinder.
[0010]
The cover of the driven portion is formed so as to be able to be closely overlapped with the inner surface of the crank pulley body, and a cover body mounting hole is formed corresponding to the same circumference as the body mounting hole of the crank pulley body. The mounting bolts are fitted and inserted into the main body mounting holes and the lid mounting holes, and reach the nut holes communicating with the main body mounting holes, respectively. Tightening, the crank pulley body and the lid may be integrally formed.
[0011]
The cover of the driven portion is formed so as to be capable of being closely overlapped on the inner surface of the crank pulley body, and a cover body square hole mounting hole is formed on the same circumference corresponding to the body mounting hole of the crank pulley body. In addition, a receiving seat is formed at the outer end of each lid square hole mounting hole, and a square root formed on the back surface of the head of the mounting bolt is fitted into the lid square hole mounting hole. After inserting each end thereof into the main body mounting hole of the crank pulley main body, the nuts reach the nut holes communicating with the main body mounting holes, respectively, and screw the nuts at the nut hole portions and tighten them from both sides. Alternatively, the crank pulley body and the lid may be integrally formed.
[0012]
The cover of the driven portion has an outer surface between each cover body square hole mounting hole, and a radially-increased decoration portion that protrudes in an inverted triangular shape from the center cover portion crankshaft loose fitting hole to the outer diameter edge. In addition, the rigidity and strength of the lid may be improved, and an eye catcher function during rotation may be provided.
[0013]
Positioning bosses are formed on the inner surface of the lid to extend the respective lid hole mounting holes to form bearing holes of the same axis, and the inner surface of the crank pulley main body has an inlet for each mounting hole. A boss fitting hole having a diameter larger than the mounting hole and having a diameter compatible with the positioning boss is formed by concentrically opening the required depth, and the boss fitting holes are positioned relative to each other when the lid body and the crank pulley body overlap. The fitting boss and the boss fitting hole may be fitted so that the axes of the two bosses coincide with each other.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
A belt power transmission device with an automatic tension adjusting mechanism for a bicycle, comprising a crank disk, a loosely fitted crank disk, and a driven portion of a lid body and a crank pulley body that is engaged and supported, wherein the crank disk is The crank disk body is formed of a crank arm and a crank arm that is integrally fixed to a side surface of the crank disk body. The crank disk body is formed on the surface opposite to the mounting surface of the crank arm, concentrically with the axis of the fixed portion of the crank arm, and equidistant from each other. The required number of circumferential row drive pins are protrudingly provided, and the crank pulley body of the driven portion has a circumferential substrate portion formed on one side and an outer diameter edge formed on one outer rim portion, The number of loose fit receiving holes corresponding to the number of circumferential drive pins of the crank disk and the number of lids on the inner surface side of the tooth portion meshing with the toothed belt, and on the inner diameter side of the tooth portion, are determined. The body mounting hole is formed, and a main body crankshaft loose fitting hole for loosely fitting the crankshaft at the center of the circumferential substrate portion is provided, and the lid of the driven portion can be closely overlapped with the inner surface of the crank pulley body. The cover mounting holes are formed and arranged on the same circumference corresponding to the main body mounting holes of the crank pulley main body, and mounting bolts are fitted into the main body mounting holes and the lid mounting holes. When the nuts are respectively inserted and reached to the nut holes communicating with the main body mounting holes, the nuts are screwed into the nut hole portions and fastened from both sides, so that the crank pulley main body and the lid are integrally formed.
[0015]
【Example】
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a belt power transmission device with an automatic tension adjusting mechanism for a bicycle according to the present invention will be described with reference to the drawings as an example of the embodiment. 1) comprises a crank disk 2, a crank pulley body 3 a which is loosely fitted to the crank disk 2 and is engaged and supported, and a driven portion 3 of a lid 3 b thereof.
[0016]
As shown in FIG. 6, the crank disk 2 is formed of a crank disk main body 2a and a crank arm 2b integrally fixed to a side surface of the crank disk main body 2a. The required number of circumferential row drive pins 4, in the embodiment, six are protrudingly provided concentrically with the axis of the fixed portion of the crank arm 2 b and at equal intervals to each other. In the embodiment, a collar 5 is fitted to each circumferential row driving pin 4. An elastic ring 6 slightly larger in diameter than the collar 5 may be further fitted to the base end 4a of each circumferential row drive pin 4.
[0017]
As shown in FIG. 7A, the crank pulley body 3a has a circumferential substrate portion 3a1 formed on one side surface, an outer diameter edge formed on one outer rim portion 7, and a toothed surface formed on the inner surface side. A bearing cylinder portion 11 having a number of loose fitting receiving holes 10 corresponding to the number of the circumferential row drive pins 4 of the crank disk 2 on the inner diameter side of the tooth portion 9 for meshing with the attached belt 8; A support cylinder portion 13 forming a main body mounting hole 12 with the body 3b is provided so as to protrude, and a main body crankshaft loose fitting hole 15 for loosely fitting the crankshaft 14 at the center of the circumferential substrate portion 3a1 is provided. . The embodiment of the crank pulley body 3a is formed of a synthetic resin material. As shown in FIG. 7B, the bush 16 made of metal may be inserted into each of the bearing cylinder portions 11 and molded as a whole, and the inner diameter surface may be provided in the loose fitting receiving hole 10. Of course, the bush is not limited to metal.
Further, depending on the molding material, the bush may not be required.
[0018]
In this embodiment, the lid 3b is similarly formed of a synthetic resin material, and as shown in FIG. 8, a circumferential outer edge is formed on the other outer rim portion 17, and an inner diameter of the inner surface is formed by the crank pulley body. 3a is formed so as to be capable of being closely polymerized on the inner surface thereof, and a lid square hole mounting hole 18 is formed and arranged corresponding to the same circumference coinciding with the main body mounting hole 12 of the crank pulley main body 3a. Receiving seats 19 are respectively formed at the outer ends of the lid square hole mounting holes 18, and the square roots 20 a 1 formed on the back surface of the head 20 a of the mounting bolt 20 are fitted and inserted into the lid square hole mounting holes 18. Then, after each of the tips is inserted into the main body mounting hole 12 of the crank pulley main body 3a, the respective nuts reach the nut holes 12a communicating with the main body mounting hole 12, and the nuts 21 are screwed into the nut holes 12a respectively. And tighten from both sides. And Lee body 3a and the lid body 3b is intended to integrally configured.
In advance, the circumferential row drive pin 4 of the crank disk 2 is loosely fitted and engaged with the loose fitting receiving hole 10 of the crank pulley body 3a, and the crank arm 2b is moved out of the lid crank shaft loose fitting hole 23. After disposing, as described above, the crank pulley main body 3a and the lid 3b are tightened with the mounting bolts 20, and the tension is entirely applied to the crank arm 2b integral with the crankshaft 14 within the clearance of the loose fitting receiving hole 10. Is supported in an adjustable manner.
[0019]
A washer 22 having a diameter larger than the outer diameter of the head 20a is fitted to the mounting bolt 20, and the outer surface of the lid 3b is doubled by the curved surface of the head 20a of the mounting bolt 20 and the flat surface of the washer 22. It can be reflected and decorated.
[0020]
The lid body 3b radially forms an outer surface between the lid body square hole mounting holes 18 and a raised decoration part 24 that protrudes in an inverted triangular shape from the center lid crankshaft loose fitting hole 23 to the outer diameter edge, The rigidity and strength of the lid 3b are improved, and an eye catcher function during rotation is provided.
[0021]
Positioning bosses 18a are formed on the inner surface of the lid 3b so as to extend from the respective lid hole square mounting holes 18 to form bearing holes having the same axis, and the inner surfaces of the crank pulley body 3a are provided with respective positioning bosses 18a. At the entrance of the mounting hole 12, a boss fitting hole 12b having a diameter larger than that of the mounting hole 12 and having a diameter compatible with the positioning boss 18a is formed at the required depth concentrically to form a cover body 3b. The boss 18a and the boss fitting hole 12b are fitted to each other during the superposition of the crank pulley body 3a and the crank pulley body 3a so that the axes of the boss 18a and the boss fitting hole 12b coincide with each other.
[0022]
Since the belt power transmission device 1 of the present invention is configured as described above, as shown in FIGS. 9 and 10, a toothed belt is provided between the belt power transmission device 1 and the power transmission pulley 25. 8, the driven part 3 constituted by the crank pulley body 3a and the lid 3b is loosely fitted, engaged and supported on the crank disk 2, and the circumferential row drive pin 4 of the crank disk body 2a and the crank pulley It moves by gravity within the range of the mutual clearance in the loose fitting receiving hole 10 of the main body 3a, reduces the distance between the shafts with the power transmission pulley 25, and stretches the toothed belt 8 in a no-load state where the belt 8 is slackened. Is what you do.
Next, as shown in FIG. 10, when a pedal force is applied to the crank arm 2b to rotate the crankshaft 14, the circumferential row drive pins 4 of the crank disk main body 2a rotate the driven part 3 along the circumferential row. Therefore, as shown in FIG. 10, the driven part 3 is moved by the width L and the tension of the toothed belt 8 is tightened, so that the toothed part 9 of the driven part 3 and the toothed belt 8 can be rotated without jumping. The power can be transmitted to the power transmission pulley 25.
[0023]
【The invention's effect】
In view of the above, the belt power transmission device of the present invention eliminates the complexity of the structure of this type of device in the related art, achieves a significant reduction in cost, and is a characteristic of the belt drive device inherently free of maintenance. In addition, the present invention exerts effects of exhibiting a number of characteristics such as quietness and light transmission, and providing a device having an excellent design appearance.
[Brief description of the drawings]
FIG. 1 is an external left side view showing an embodiment of a belt power transmission device of the present invention.
FIG. 2 is also a plan view.
FIG. 3 is also a right side view.
FIG. 4 is a cross-sectional view taken along the line AA of FIG.
FIG. 5 is a longitudinal sectional view taken along line BB of FIG. 1;
FIG. 6 is a perspective view of a single crank disk constituting the belt power transmission device.
FIG. 7A is a perspective view of the crank pulley main body constituting the belt power transmission device viewed from the inner surface side.
FIG. 7B is a perspective view of the crank pulley main body constituting the belt power transmission device as viewed from the inner side, showing an embodiment in which a bush is provided in a bearing cylinder.
FIG. 8 is a perspective view of an outer surface of a lid alone constituting the belt power transmission device.
FIG. 9 is a side view illustrating an operation state of the belt power transmission device according to the present invention at the time of no-load driving.
FIG. 10 is a side view for explaining an operation state of the belt power transmission device when driving a load.
FIG. 11 is an exploded perspective view showing a conventional belt power transmission device of this type.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Belt power transmission device 2 Crank disk 2a Crank disk main body 2b Crank arm 3 Driven part 3a Crank pulley main body 3a1 Circular substrate part 3b Lid 4 Circular row drive pin 4a Base end 5 Collar 6 Elastic ring 7 One outer rim Part 8 toothed belt 9 tooth part 10 loose fitting receiving hole 11 bearing cylinder part 12 body mounting hole 12a nut hole 12b boss fitting hole 13 support cylinder part 14 crankshaft 15 main body crankshaft loose fitting hole 16 metal bush 17 Outer rim portion 18 Lid square hole mounting hole 18a Positioning boss 19 Receiving seat 20 Mounting bolt 20a Head 20a1 Square root 21 Nut 22 Washer 23 Lid crankshaft loose fitting hole 24 Raised decorative part 25 Power transmission pulley

Claims (9)

A belt power transmission device with an automatic tension adjusting mechanism for a bicycle, comprising a crank disk, a crank pulley body that is loosely fitted to the crank disk, and is engaged with and supported by a crank pulley body, and a driven portion of a lid thereof. The crank disk is formed of a crank disk main body and a crank arm integrally fixed to a side surface of the crank disk. The crank disk main body is formed on a surface opposite to a mounting surface of the crank arm, concentrically with an axis of a crank arm fixing portion, and 2. The belt power transmission device with an automatic tension adjusting mechanism for a bicycle according to claim 1, wherein a required number of circumferential row drive pins protrude from each other at equal intervals. The crank pulley body of the driven portion has a circumferential substrate portion formed on one side, an outer diameter edge formed on one outer rim portion, and a tooth portion meshing with a toothed belt on the inner surface side, A number of loose fitting receiving holes and a body mounting hole for the lid body corresponding to the number of the circumferential row drive pins of the crank disk are formed on the inner diameter side of the tooth portion, and the crank shaft is loosened at the center of the circumferential substrate portion. The belt power transmission device with an automatic tension adjusting mechanism for a bicycle according to claim 1 or 2, further comprising a loose fit hole for a main body crankshaft to be fitted. The crank pulley body of the driven portion has a circumferential substrate portion formed on one side, an outer diameter edge formed on one outer rim portion, and a tooth portion meshing with a toothed belt on the inner surface side, A bearing cylinder portion forming a number of loose fitting receiving holes corresponding to the number of the circumferential row drive pins of the crank disk on an inner diameter side of the tooth portion, and a support cylinder portion forming a main body mounting hole with the lid are raised. The belt power transmission device with an automatic tension adjusting mechanism for a bicycle according to claim 1 or 2, further comprising a main body crankshaft loose fitting hole for loosely fitting the crankshaft to the center of the circumferential substrate portion. The belt power transmission device with an automatic tension adjusting mechanism for a bicycle according to claim 3 or 4, wherein the crank pulley body of the driven portion has a wear-resistant bush provided on each bearing cylinder portion. The cover of the driven portion is formed so as to be able to be closely overlapped with the inner surface of the crank pulley body, and a cover body mounting hole is formed corresponding to the same circumference as the body mounting hole of the crank pulley body. The mounting bolts are fitted and inserted into the main body mounting holes and the lid mounting holes, reach the nut holes communicating with the main body mounting holes, respectively, and nuts are screwed at the nut hole portions and tightened from both sides. 6. The belt power transmission device with an automatic tension adjusting mechanism for a bicycle according to claim 1, wherein the crank pulley body and the lid are integrally formed. The cover of the driven portion is formed so as to be capable of being closely overlapped on the inner surface of the crank pulley body, and a cover body square hole mounting hole is formed on the same circumference corresponding to the body mounting hole of the crank pulley body. In addition, a receiving seat is formed at the outer end of each lid square hole mounting hole, and a square root formed on the back surface of the head of the mounting bolt is fitted into the lid square hole mounting hole. After inserting the respective ends into the main body mounting holes of the crank pulley main body, the nuts reach the nut holes communicating with the main body mounting holes, respectively, and nuts are screwed into the nut hole portions and tightened from both sides. 6. The belt power transmission device with an automatic tension adjusting mechanism for a bicycle according to claim 1, wherein the crank pulley body and the lid are integrally formed. The cover of the driven portion has an outer surface between each cover body square hole mounting hole, and a radially-increased decoration portion that protrudes in an inverted triangular shape from the center cover portion crankshaft loose fitting hole to the outer diameter edge. 8. The belt power transmission device with an automatic tension adjusting mechanism for a bicycle according to claim 6, wherein the rigidity and strength of the lid are improved and an eye catcher function is provided during rotation. Positioning bosses are formed on the inner surface of the lid to extend the respective lid hole mounting holes to form bearing holes of the same axis, and the inner surface of the crank pulley main body has an inlet for each mounting hole. A boss fitting hole having a diameter larger than the mounting hole and having a diameter compatible with the positioning boss is formed by concentrically opening the required depth, and the boss fitting holes are positioned relative to each other when the lid body and the crank pulley body overlap. 9. The belt power transmission device with an automatic tension adjusting mechanism for a bicycle according to claim 6, wherein the mating boss and the boss fitting hole are fitted so that the axes of the two bosses coincide with each other.

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