JP2018034567A - Bicycle frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bicycle frame capable of acquiring a driving force through twisting.MEANS FOR SOLVING THE PROBLEM: A frame 8 of a bicycle 2 is provided with: a front frame body 22 that holds a front fork 10; and a rear frame body 32 that extends forward from a rear claw 24, and configured such that elastic support means 48 is fitted to the frame body 22. The elastic support means 48 supports the rear frame body 32 so as to be horizontally oscillated to one side by moving the weight of an occupant to one side of the bicycle 2, and temporarily stores a part of a force generated by the weight movement. The stored force is transmitted to a rear wheel 6 to become a driving force for extruding a bicycle body when the rear frame body 32 is returned from the horizontal oscillation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bicycle frame.

  In general, a bicycle includes a frame that supports a front wheel and a rear wheel. In addition to the wheels, the steering device, saddle, and drive device are attached to the frame. The rider on the saddle applies pedaling force to the drive device while operating the steering device, and the bicycle travels on the ground. To do.

  In the bicycle driven and driven in this manner, Patent Document 1 describes a technique that elastically deforms a frame and uses a reaction caused by the deformation. In this technique, a rear center expansion / contraction means is provided on the chain stay of the frame. The rear center expansion / contraction means is constituted by a spring or a shape that elastically reduces the distance (rear center) from the crankshaft centerline to the rear wheelshaft centerline by the chain pulling force when the occupant steps on the pedal. According to such a technique, when the pedal is depressed, a part of the pedaling force is temporarily stored in the rear center expansion / contraction means, and then a part of the stored pedaling force is used for driving the rear wheel. The driving force is averaged and the burden on the occupant is reduced.

  In addition to the above-mentioned documents, a technique for running a bicycle while elastically deforming a frame is known. For example, in a bicycle competition, there are athletes who use the reaction to propel the bicycle by flexing the frame during a dancing run in which the pedal is depressed while alternately swinging the frame left and right. Such a traveling technique can obtain a large rear wheel driving force by dancing traveling and a driving force by bending the frame, so that the traveling speed of the bicycle can be dramatically accelerated.

JP 2013-216252 A

  However, traveling using the frame flexure as described above requires wearing a foam suitable for the frame flexure and muscle strength that surpasses the rigidity of the frame. It is difficult for them.

  In view of the above-described problems, an object of the present invention is to provide a bicycle frame capable of easily obtaining a propulsive force due to bending.

  To achieve the above object, the present invention provides a bicycle frame having a front wheel and a rear wheel, the front frame body holding a front fork on which the front wheel is pivotally supported, and the rear wheel being pivotally supported. A rear frame body that extends forward from the shaft support portion, and a rear frame body that is attached to the front frame body and that can swing the rear frame body to the one side by moving the weight of an occupant to one side of the reference center plane of the bicycle. And elastic support means for supporting.

  Further, the bicycle frame of the present invention has a back fork in which the rear frame body extends upward, and a chain stay in which a hanger lug is fixed to a tip end extending below the back fork. The elastic support means includes back fork support means for elastically supporting the back fork and hanger support means for supporting the hanger lug so as to be rotatable about a forward tilt axis.

  According to the present invention, when the occupant's weight shift occurs on one side of the bicycle, such as when the pedal is depressed, the rear frame body is elastically shaken by the elastic support means, and part of the force generated by the weight shift is elastic. Once stored in the support means. After that, a part of the accumulated force acts on the rear frame body as a force for returning the frame body after the lateral swing and is transmitted to the rear wheel via the shaft support portion. The component of the force transmitted to the rear wheel acts as a propulsive force that pushes the bicycle in the traveling direction by friction with the ground. Thus, the frame can be bent only by weight shift, and the propulsive force can be easily obtained.

Schematic diagram of the bicycle according to the first embodiment Cross-sectional view of backhawk support means Cross section of hanger support means (A) Schematic diagram of a frame in a general traveling state, (b) Schematic diagram of a frame when the left pedal is depressed during dancing traveling, (c) Schematic of a frame when the right pedal is depressed during dancing traveling Figure Schematic diagram of a bicycle according to the second embodiment Sectional drawing of the hanger support means in the bicycle which concerns on 2nd Embodiment. Sectional drawing of the hanger support means when it cuts in the plane different from FIG.

[First Embodiment]
Embodiments of a bicycle frame according to the present invention will be described below in detail with reference to the drawings. In the following description, the straight direction of the bicycle is referred to as the front, and the opposite direction is referred to as the rear. In addition, JIS D9111 is appropriately used as a term representing the configuration of the bicycle.

  As shown in FIG. 1, the bicycle 2 according to this embodiment has a frame 8 to which a front wheel 4 and a rear wheel 6 are attached. The frame 8 includes a front fork 10 that pivotally supports the front wheel 4, a frame body 12 that holds the front fork 10, and a frame component that is attached to a predetermined portion of the frame body 12.

  The frame body 12 includes a front frame body 22 having a head pipe 14, an upper pipe 16, a lower pipe 18, and a standing pipe 20, and a rear frame body 32 having a rear pawl 24, a back hawk 26, a chain stay 28, and a hanger lug 30. And. For each part constituting the frame body 12, chrome molybdenum steel is typically used.

  The head pipe 14 is a pipe extending in the vertical direction, and a fork stem (not shown) of the front fork 10 is passed therethrough. The fork stem of the front fork 10 is supported by a head part (not shown) which is a frame part built in the head pipe 14 so as to be rotatable around the central axis of the head pipe 14 and is operated at the upper part thereof. A device 34 is attached. An upper pipe 16 and a lower pipe 18 extend rearward from the head pipe 14. A rear end portion of the upper pipe 16 is connected to an upper portion of the standing pipe 20 via a seat lug 36. A seat part 38, which is one of frame parts, is built in the upper part of the vertical pipe 20, and a saddle 42 is attached to a seat post 40 of the seat part 38. The front frame body 22 is configured in such a manner.

  The rear pawl 24 that is a shaft support portion that supports the wheel shaft 44 of the rear wheel 6 is provided on both the left and right sides of the wheel shaft 44. A pair of left and right back hawks 26 and a pair of left and right chain stays 28 extend from each rear pawl 24 toward the front. A hanger lug 30 is fixed to the ends of the pair of left and right chain stays 28.

  The rear frame body 32 configured in the above manner is supported by elastic support means 48 attached to the rear portion of the front frame body 22. In this embodiment, the elastic support means 48 includes a back fork support means 50 for supporting the back fork 26 and a hanger support means 52 for supporting the hanger lug 30.

  The back hawk support means 50 is disposed on the upper portion of the front frame body 22 and includes a horizontal cylinder 54, an inner rubber 56, and a horizontal rod 58 as shown in FIG.

  The horizontal cylinder 54 is in a posture perpendicular to the reference center plane A of the bicycle 2 and has a cylindrical portion 60 whose outer peripheral surface 66 is brazed to the standing pipe 20 and a reference central plane A at the inner peripheral surface 68 of the cylindrical portion 60. And an annular convex part 62 formed so as to protrude inward (a central part). A pair of inner rubbers 56 are housed on the left and right sides of the annular protrusion 62. Each of the inner rubbers 56 is a columnar urethane that extends from the annular convex portion 62 of the horizontal cylinder 54 to the opening end 64, and includes an outer peripheral surface 70 that is in close contact with the inner peripheral surface 68 of the horizontal cylinder 54, and a reference center plane. And an outer surface 74 that extends into the opening of the horizontal cylinder 54. Each inner rubber 56 is provided with a hole 76 in a direction orthogonal to the reference center plane A, and one horizontal rod 58 is passed from one inner rubber 56 to the other inner rubber 56. That is, the horizontal cylinder 54 and the inner rubber 56 are elastic supports that elastically support the horizontal rod 58.

  The horizontal rod 58 is arranged in a state where both end portions thereof protrude from the pair of inner rubbers 56, and a male screw is formed over the entire length thereof. At the both ends of the horizontal rod 58, the tip of each back hawk 26 is attached. That is, the horizontal rod 58 is a connecting body that connects the pair of left and right back forks 26.

  A hole 78 through which the horizontal rod 58 can be inserted is formed at the tip of each back hawk 26. Each back fork 26 is attached to the inner rubber 56 by tightening a nut 80 screwed into the end of the horizontal rod 58 passed through the hole 78. Each of the back hawks 26 is disposed with a gap between the back hawk 26 and the horizontal cylinder 54. Accordingly, the back hawk 26 is elastically swingable by being attached to the horizontal rod 58 passed through the inner rubber 56. That is, the horizontal cylinder 54, the inner rubber 56, and the horizontal rod 58 function as the back hawk support means 50 that elastically supports the back hawk 26 so as to be swingable.

  Returning to FIG. 1, the hanger support means 52 is disposed at the lower part of the front frame body 22, and has a forward tilt cylinder 82, a thrust bearing 84, and a forward tilt shaft 86 as shown in FIG. 3.

  The forward tilt cylinder 82 has a cylindrical portion 90 in which an outer peripheral surface 88 is brazed to the lower pipe 18 and the standing pipe 20 in a forward inclined posture, and an annular protrusion formed above and below the inner peripheral surface 92 of the cylindrical portion 90. Part 94. In such a forward tilt cylinder 82, one thrust bearing 84 is accommodated above the upper annular convex portion 94, and another thrust bearing 84 is accommodated below the lower annular convex portion 94. A forward tilting shaft 86 is passed between one thrust bearing 84 and another thrust bearing 84. In other words, the forward tilt cylinder 82 and the thrust bearing 84 function as a rotation support body that rotatably supports the forward tilt shaft 86.

  The forward tilt shaft 86 is supported by a thrust bearing 84 housed in the forward tilt cylinder 82, so that the axis (center line B) is tilted forward at an angle of approximately 25 degrees with respect to the vertical line. A male screw is formed over the entire length of the forward inclined shaft 86, and the nut 96 screwed up and down is tightened until each thrust bearing 84 comes into contact with each annular projection 94. Thus, the forward tilt cylinder 82, the thrust bearing 84, and the forward tilt shaft 86 are combined with each other. A hanger lug 30 is attached to the lower end portion of the forward inclined shaft 86. Thus, the forward tilt shaft 86 is a forward tilt shaft that is attached to the hanger lug 30 in a forward tilted posture.

  The hanger lug 30 can be rotated around the forward tilting shaft 86 by being attached to the forward tilting shaft 86. That is, the forward tilt cylinder 82, the thrust bearing 84, and the forward tilt shaft 86 function as the hanger support means 52 that supports the hanger lug 30 so as to be rotatable around an axis tilted forward with respect to the vertical line.

  Such a hanger lug 30 incorporates a hanger part (not shown), and a driving device (not shown) for driving the rear wheel 6 (FIG. 1) is attached to the hanger part. The bicycle 2 travels when a pedaling force is applied to a pedal (not shown) of the driving device.

  The deformation | transformation aspect of the flame | frame of the bicycle 2 during driving | running | working is demonstrated based on FIG. First, in a general traveling state in which the occupant sits on the saddle 42 in a normal riding posture and drives and controls the bicycle 2, elastic deformation does not occur in the urethane inner rubber 56 included in the backhawk support means 50. For this reason, the rear frame body 32 travels in a posture shown in FIG.

  Here, in order to dramatically accelerate the traveling speed, when the occupant performs a dancing traveling, the front frame body 22 is alternately swung to the left side and the right side, and the right pedal and the left pedal are alternately synchronized with this. Step on. Since a pedaling force to which the weight of the occupant is added is applied to the depressed pedal, the rear frame body 32 rotates around the center line B of the forward tilting shaft 86 while elastically deforming the inner rubber 56, It will sway to the depressed pedal side. FIG. 4B shows a state where the left pedal is depressed while swinging the front frame body 22 to the right. FIG. 4C shows a state where the right pedal is depressed while the front frame body 22 is swung to the left. At this time, the inner rubber 56 temporarily stores a part of the pedaling force to which the weight is added in the process of elastic deformation.

  Thereafter, the force stored in the inner rubber 56 acts on the rear frame body 32 as a force that causes the frame body 32 to return to the reference center plane A of the bicycle 2 after sideways swinging, and acts on the rear wheel 6 via the rear pawl 24. Communicated. The component force Fx of the force F transmitted to the rear wheel 6 acts as a propulsive force that pushes the bicycle 2 in the traveling direction by friction with the ground. Thus, according to the present embodiment, the propulsive force can be obtained by easily deflecting the frame 8 by moving the body weight during dancing.

  The present invention is not limited to the first embodiment described above, and may be a second embodiment described below. In addition, description of a common structure is abbreviate | omitted or only mentioned as needed.

[Second Embodiment]
As shown in FIG. 5, the bicycle 102 according to the second embodiment is attached to the front frame body 22 such that the rear end of the lower pipe 18 is connected to the lower end portion of the standing pipe 20 by brazing. The configuration of the hanger support means 104 is different from that of the first embodiment.

  The hanger support means 104 in the present embodiment is shown in FIG. 6 which is a cross-sectional view taken along a plane that includes the short axis straight line C and intersects the reference center plane A. The hanger support means 104 has two sets of horizontal cylinders 106a and 106b and inner rubbers 108a and 108b, and horizontal rods 110a and 110b and side rubbers 112L and 112R, respectively.

  Each set of horizontal cylinders 106a and 106b has a cylindrical portion 90 and an annular convex portion 94, and a pair of inner rubbers 108a and 108b are accommodated therein, and the inner rubbers 108a and 108b are cylindrical urethanes. And is common to the backhawk support means 50 in that the horizontal rods 110a and 110b are passed through the holes 114.

  On the other hand, as shown in FIG. 7 which is a cross-sectional view taken along the reference center plane A, it differs from the back fork support means 50 in that the cross-sectional shapes of the horizontal cylinders 106a and 106b are formed in an ellipse. Yes. The first horizontal cylinder 106a is moved to the lower pipe 18 so that a straight line connecting the short axes of the ellipse (hereinafter referred to as “short axis straight line C”) is inclined forward at an angle of approximately 25 degrees with respect to the vertical line. The second horizontal cylinder 106 b is fixed to the vertical pipe 20. The pair of inner rubbers 108a and 108b is different from the above-described back hawk support means 50 in that the inner rubbers 108a and 108b are compressed and stored so that the cross-sectional shape thereof becomes an ellipse. The inner rubbers 108a and 108b that are compressed and stored in this way are not easily elastically deformed in the short axis direction (compression direction) and are easily elastically deformed in the long axis direction, and are stored in such inner rubbers 108a and 108b. The horizontal rods 110a and 110b thus made can be elastically rotated around the short axis direction. That is, the horizontal cylinders 106a and 106b and the inner rubbers 108a and 108b function as elastic supports that elastically support the horizontal rods 110a and 110b so as to be rotatable around the short axis straight line C.

  Returning to FIG. 6, a pair of arms 116 are arranged on both sides of each horizontal cylinder 106a, 106b. The pair of arms 116 are symmetrically extended from the left and right end portions of the hanger lug 30, and have a first attachment portion 118 and a second attachment portion 120, and a first connection portion 122 and a second connection portion 124. doing. The first attachment portion 118 and the second attachment portion 120 are disposed on both sides of the first horizontal cylinder 106a and the second horizontal cylinder 106b, respectively, and have a bottom plate portion 126 and a cylindrical portion 128. Holes 130 through which the horizontal rods 110a and 110b are passed are formed in the bottom plate portion 126, and the holes 130 are arranged so as to communicate with the holes 114 of the inner rubbers 108a and 108b. A cylindrical portion 128 extends from the edge of the bottom plate portion 126 in the direction opposite to the inner rubbers 108a and 108b. Each of the cylindrical portions 128 accommodates side rubbers 112L and 112R made of cylindrical urethane, and the side rubbers 112L and 112R have holes 132 communicating with the holes 130 of the bottom plate portion 126. . One horizontal rod 110a, 110b is passed from one side rubber 112a to the other side rubber 112b. The horizontal rods 110a and 110b are arranged in a state where both ends protrude from the holes 132 of the side rubbers 112L and 112R, and nuts 134 screwed to the both ends are tightened. The first mounting portion 118 and the second mounting portion 120 are connected by the first connecting portion 122, and the second mounting portion 120 and the hanger lug 30 are connected by the second connecting portion 124.

  As shown in FIGS. 4 (b) and 4 (c), when an occupant riding such a bicycle 102 performs a dancing run, the rear frame body 32 is an inner rubber of the back hawk support means 50 (FIG. 5). (FIG. 2) and the inner rubbers 108a and 108b (FIG. 7) of the hanger support means 104 (FIG. 5), while being elastically deformed, turn around the short axis C (FIG. 5) and move toward the depressed pedal side. It will swing sideways. In the inner rubber 56 (FIG. 2) and 108 (FIG. 7), a part of the pedaling force to which the weight is added is temporarily stored in the process of elastic deformation.

  Thereafter, the force stored in the inner rubbers 56 (FIG. 2) and 108 (FIG. 7) acts on the rear frame body 32 as a force that causes the frame body 32 to return to the reference center plane A of the bicycle 102 after lateral shaking, It is transmitted to the rear wheel 6 via the rear pawl 24. The component force Fx of the force F transmitted to the rear wheel 6 acts as a propulsive force that pushes the bicycle 102 in the traveling direction by friction with the ground. Thus, according to the present embodiment, the propulsive force can be obtained by easily deflecting the frame 8 by moving the body weight during dancing.

  The present invention may be appropriately modified from the above-described embodiment. Hereinafter, modifications will be described.

  Each pipe constituting the frame 8 is not limited to the illustrated one. For example, the head pipe 14 may be a front fork holding body that rotatably holds a fork stem (not shown) of the front fork 10, and various shapes such as a pipe shape and a ring shape may be adopted. it can. The material is not particularly limited.

  Further, the upper pipe 16 and the lower pipe 18 may be any extending portion that extends from the head pipe 14 (front hawk holder) to the standing pipe 20, and may be configured by one or three or more pipes. . Moreover, it may be a rod shape instead of a pipe shape.

  The back hawk support 50 may be provided on the upper pipe 16. For example, in the upper pipe 16, the back hawk support portion 50 may be provided at the intersection of the axis B and the extended line of the short axis straight line C. Further, the back hawk support 50 may be provided on the head pipe 14. Thus, the back fork 26 may be connected to any of the front frame bodies 22 via the back fork support part 50.

  Furthermore, in 2nd Embodiment, the back frame body 32 which does not have the back fork 26 may be sufficient.

  The angles of the axis B and the short-axis straight line C with respect to the vertical line are not limited to approximately 25 degrees and are appropriately determined.

  Although the hanger lug 30 is attached to the front frame body 22 via the hanger support means 52, a hanger lug may be attached to the front frame body 22 and the hanger support means may be interposed between the hanger lug and the chain stay 28.

  The present invention can be carried out in various modifications, corrections, and modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention, and all of these aspects belong to the scope of the present invention. is there.

2 ... Bicycle 4 ... Front wheel 6 ... Rear wheel 8 ... Frame 22 ... Front frame body 26 ... Back fork 28 ... Chain stay 30 ... Hanger lug 32 ... Rear frame body 48 ... Elastic support means 50 ... Back fork support means 52 ... Hanger support means

Claims (2)

A bicycle frame having front and rear wheels,
A front frame body that holds a front fork supported by the front wheel;
A rear frame body extending forward from a shaft support portion on which the rear wheel is supported;
Elastic support means attached to the front frame body and supporting the rear frame body to be able to sway laterally to the one side by shifting the weight of an occupant to one side of the bicycle;
Bicycle frame with The rear frame body is
A back hawk extending upward,
A chain stay extending below the back hawk and having a hanger lug fixed to the tip, and the elastic support means,
Backhawk support means for elastically supporting the backhawk;
Hanger support means for rotatably supporting the hanger lug about a forward tilt axis;
The bicycle frame according to claim 1.

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