JP3973741B2 - Bicycle frame - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high-strength bicycle frame that can be used for multifunctional bicycles.
[0002]
[Prior art]
Conventionally, as a bicycle frame that can be adapted to a bicycle having this type of folding function and buffer function, for example, a bicycle folding frame in which the middle portion of the front frame is configured to be foldable by a substantially vertical folding rotation shaft. Various bicycle frames with a rear wheel shock absorber have been proposed.
Bicycle folding frames in which the middle part of the front frame is configured to be foldable by a substantially vertical folding rotation shaft include those disclosed in Japanese Utility Model Publication No. 37-13506, Japanese Utility Model Publication No. 63-18560, and the like. Some are disclosed in the publication.
In what is disclosed in Japanese Utility Model Publication No. 37-13506, as a locking mechanism for the folding hinge portion, conical irregularities are provided on the upper and lower sides of the hinge shaft, and the upper and lower irregularities are simultaneously tightened with bolts penetrating them. Thus, the frictional force of the conical surface in these concave and convex portions enables the hinge portion to be fixed without backlash. However, since the folding portion is fixed to the hinge shaft by rotation, a large amount around the hinge shaft can be obtained. The structure is disadvantageous against the rotational moment. Therefore, sufficient frame rigidity cannot be obtained.
[0003]
Therefore, the one disclosed in the Japanese Utility Model Publication No. 63-18560 has been proposed. This will be described with reference to FIG. 10. The front plate 47 and the rear plate joined to the front and rear folding frames 41A and 41B, respectively. A hinge comprising a hinge 45 and a support shaft 46 is provided on the side of 48, and the front plate 47 and the rear plate 48 are superposed by a latch 55 that is a lock member that slides by a lever 57 in the vicinity of the opposite side of the hinge. The frame running state is locked. In this frame running state, after the two upper and lower receivers 52, 52 implanted in the rear plate 48 are inserted into the corresponding window holes 53, 53 in the front plate 47, the receivers 52, 52 are engaged. In the holes 56, 56, the frame running state in which the front plate 47 and the rear plate 48 overlap is locked by the sliding engagement of the latch 55 via the upper and lower links 60, 60 accompanying the swing of the lever 57. Is. In the figure, reference numeral 51 denotes a stand, which makes it possible to stand a folded bicycle. Reference numeral 59 denotes a shaft support portion for attaching the lever 57 to the abutment 58.
[0004]
On the other hand, bicycles with rear wheel shock absorbers include those disclosed in Japanese Utility Model Publication No. 40-8009 and those disclosed in Japanese Utility Model Publication No. 43-28258.
In each of these, the front end of the swing arm of the rear wheel constituting the rear frame is pivotally supported at the rear end of the frame extending further rearward from the hanger pipe, and the swing is provided near the pivotal support. A shock absorber such as rubber for buffering the moving arm is provided.
Accordingly, in these devices, the pivot shaft support position of the swing arm of the rear wheel is configured to be separated from the line of the drive pull side chain of the rear wheel drive chain.
[0005]
[Problems to be solved by the invention]
However, in such a conventional folding frame and a frame with a rear wheel shock absorber, the folding length disclosed in Japanese Utility Model Publication No. 63-18560 in FIG. In addition, by making the hinge part and the lock part independent, high rigidity is obtained in the vertical direction of the hinge part, and the locking action is more reliably maintained, but the frame locking mechanism also serves as a stand Therefore, clearance for smooth sliding is required, causing backlash of the lock mechanism frame body, and the running state of the frame is locked by overlapping of the front and rear plates, etc. Its structure is complex and heavy.
Further, in the bicycles with rear wheel shock absorbers disclosed in the Japanese Utility Model Publication Nos. 40-8009 and 43-28258, the pivot position of the rear frame is approximately at the center of the upper and lower chain portions of the drive chain. Therefore, when riding, the frame tends to move down from the pull side chain due to the weight of the passenger, and the length of the arm that swings the back frame due to the tension of the pull side chain becomes longer. This caused a power loss. Further, since the pivot position, which is the swing center of the rear frame, does not become a substantially vertical position with respect to the direction of impact input to the rear wheel, the impact absorption efficiency is also inferior.
Further, since the pivot position of the rear frame is separated from the pulling side chain, the rear frame swings with respect to the direction of impact input to the rear wheel, and the variation of the rear center is increased. In addition, shock absorbers such as rubber for cushioning the swing arm are exposed, and ozone deterioration is likely to occur due to long-term use.
[0006]
Therefore, it solves the problems in the conventional folding frame with a rear wheel shock absorber as described above, and can maintain the running state of the frame reliably without causing a decrease in rigidity, but has an excellent appearance. It is an object of the present invention to provide a bicycle frame that can be used for a folding bicycle having a folding portion that is lightweight and has a simple structure, and a folding bicycle with a rear shock absorber that has low unsprung load and power loss and high shock absorption efficiency.
[0007]
[Means for Solving the Problems]
For this reason, the present invention is constructed by joining a head pipe and a standing pipe having a hanger pipe joined to a lower end portion by an upper pipe and a lower pipe, and a plurality of truss-like reinforcing members are stretched between the upper and lower pipes. A bicycle frame in which an intermediate portion of the front frame is configured to be foldable by a substantially vertical folding rotation shaft, wherein the folding rotation shaft is concentric with the truss-shaped reinforcing member. It is.
Further, according to the present invention, the folded portion of the intermediate portion of the front frame constituting a part of the plurality of truss-shaped reinforcing members is composed of a pair of left and right pipe-shaped reinforcing members, and one of the reinforcing members is folded. While constituting a rotating shaft, the other constitutes a folding lock mechanism.
Further, the present invention is characterized in that one of the pair of reinforcing members constituting the folding rotation shaft and the folding lock mechanism is joined to the front front frame and the other is joined to the rear front frame. .
According to the present invention, the upper and lower pipes constituting the front frame are formed in a substantially flat cross-sectional shape, and a plurality of truss-like reinforcing members stretched between them are formed by pipes thinner than the upper and lower pipes. It is characterized by.
Further, the present invention is configured by joining a head pipe and a standing pipe having a hanger pipe joined to a lower end portion by an upper pipe and a lower pipe, and a plurality of truss-like reinforcing members are stretched between the upper and lower pipes. The upper pipe of the front frame is extended to the rear of the standing pipe, and the front upper apex of the substantially triangular rear frame is pivotally supported at the rear end thereof, and the front lower apex of the rear frame is supported by the front frame. It is characterized by being connected to a shock absorber installed behind the hanger pipe.
Further, the present invention is characterized in that a shock absorber in the shock absorber is built in a cylinder constituting a part of a frame installed behind the hanger pipe.
Further, the present invention is characterized in that the shock absorber in the shock absorber is composed of a compressed rubber elastomer divided into a plurality of parts in the axial direction.
Further, the present invention is configured by joining a head pipe and a standing pipe having a hanger pipe joined to a lower end portion by an upper pipe and a lower pipe, and a plurality of truss-like reinforcing members are stretched between the upper and lower pipes. In the bicycle frame in which the middle portion of the front frame is configured to be foldable by a substantially vertical folding rotation shaft, the folding rotation shaft is configured concentrically with the truss-shaped reinforcing member, and the front frame The upper pipe is extended to the rear of the upright pipe, and the front upper apex of the substantially triangular rear frame is pivotally supported at the rear end thereof, and the front lower apex of the rear frame is arranged behind the hanger pipe of the front frame. It is characterized in that it is connected to a shock absorber installed in the above, and these are used as means for solving the problems.
[0008]
[Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 9 show one embodiment of a folding frame with a rear wheel shock absorber for a bicycle according to the present invention. FIG. 1 is an overall side view of a bicycle in a running state, and FIG. 2 is an entire bicycle in a folded state. FIG. 3 is a sectional view of the folding lock mechanism, FIG. 5 is a sectional view of the folding rotation shaft, and FIG. 6 is a separation of the folding locking mechanism. FIG. 7 is a sectional view of the shaft support portion of the front frame and the rear frame, FIG. 8 is a sectional view of the shock absorber, and FIG.
As shown in FIG. 1 (A), the folding frame with a rear wheel shock absorber according to the present invention includes a head pipe 1 and a standing pipe 4 having a hanger pipe 8 joined to a lower end thereof at an upper pipe 2 and a lower pipe 3. The middle part of the front frame F formed by joining and stretching a plurality of truss-shaped reinforcing members 6 (11 and 12 described later) between the upper and lower pipes 2 and 3 is a substantially vertical folding rotation shaft 10. It is configured to be foldable.
The folding rotation shaft 10 is installed concentrically with the truss-shaped reinforcing member 12 as will be described later.
[0009]
And the folding part of the intermediate part of the said front frame F which comprises a part of several truss-shaped reinforcement members 6, 11, and 12 is a pair of right and left pipe-shaped reinforcement members, as shown in FIG.1 (B). 11 and 12, and one of the reinforcing members 12 constitutes a folding rotation shaft, and the other 11 constitutes a folding lock mechanism.
Therefore, as shown in FIGS. 3A and 3B, the front part is divided into the front front frame F1 and the rear part is divided into the rear front frame F2, with the folding part constituting the folding rotation shaft as a boundary. The front front frame F1 includes upper and lower front pipes 2F and 3F, and the rear front frame F2 includes upper and lower rear pipes 2R and 3R.
Further, as shown in the folded state diagram of FIG. 2 (B) and FIG. 3 (B), one folding pivot shaft of the pair of reinforcing members respectively constituting the folding pivot shaft and the folding lock mechanism. The side 12 is joined to the front front frame F1, and the other side 11 is joined to the rear front frame F2.
[0010]
The upper and lower pipes 2 and 3 constituting the front frame F are configured to have a slightly larger substantially flat cross-sectional shape (a rectangle or an ellipse having a long axis in the width direction on the left and right sides of the vehicle body), and a truss stretched between them. The plurality of reinforcing members 6, 11, and 12 are formed by pipes that are thinner than the upper and lower pipes 2 and 3 (the reinforcing member 6 may be a round pipe or a square pipe).
The upper pipe 2R of the rear front frame F2 in the front frame extends to the rear of the upright pipe 4 and is supported at the rear end by the pivot shaft 5 at the front upper apex of the substantially triangular rear frame R. A front lower apex portion of the rear frame R is connected to a shock absorber (20) installed behind the hanger pipe 8 of the front frame F.
As shown in FIG. 7, the shaft portion of the rear frame R to the front frame F by the pivot shaft 5 is provided with a cap 33 on a bracket 31 fixed to the rear end portion of the upper rear pipe 2R of the rear front frame F2. Then, the pivot bolt 5 and the nut 34 screwed to the pivot bolt 5 are arranged in the vehicle body transverse direction, and the collar 35 is fitted thereto.
On the other hand, the front end portions of the left and right back forks 19L, 19R constituting the rear frame R are connected by a cylindrical portion 36, and the cylindrical portion 36 is supported on the outer periphery of the collar 35 by fitting. Reference numeral 32 denotes a bush disposed between the collar 35 and the cylindrical portion 36.
[0011]
The shock absorber installed between the front lower apex of the rear frame R and the rear of the hanger pipe 8 of the front frame F is configured as follows.
As shown in FIG. 8, the cylinder 20 extends rearward from the hanger pipe 8, and the bush 30 is interposed between the front ends of a pair of left and right chain stays 7 </ b> L and 7 </ b> R constituting the rear frame R. A bolt 27 in the transverse direction of the vehicle body to be connected and a nut 28 screwed to the bolt 27 are arranged.
A rod end 26 is pivotally supported on the bolt 27 and a movable rod 24 in the longitudinal direction of the vehicle body is disposed. A front portion of the movable rod 24 is split between a screw cap 37 and a nut 21 in an axial direction made of urethane rubber or the like. A plurality of (two in the illustrated example) shock absorbers 22 are arranged. By screwing the screw cap 37 into the rear end portion of the cylinder 20, a chain stay that is given a passenger's weight and moves rearward by swinging the rear frame R about the pivot bolt 5 as an axis. The shock absorber 22 performs a compression buffering action by the tension buffering action of 7L and 7R. Reference numeral 25 denotes a stopper rubber which is disposed outside the screw cap 37 and cushions it when the rear frame R is returned and swung downward. Reference numeral 23 denotes a bush.
[0012]
A pair of left and right folding rotation shafts and a folding lock mechanism that are part of the plurality of truss-like reinforcing members and constitute the folding part will be described with reference to FIGS. 4, 5, and 6. Thus, with respect to the folding rotation shaft portion, the folding rotation shaft 10 is installed concentrically with the pipe-shaped reinforcing member 12 that constitutes the truss, and the reinforcing member 12 is located in front of the front front frame F1 in the upper and lower directions. The pipes 2F and 3F are joined to the hinge lugs 2A and 3A, respectively. Then, by the upper and lower shoulder bolts 10A and 10B constituting the folding rotation shaft 10, the hinge lugs 2B and 3B of the upper and lower rear pipes 2R and 3R are turned to the hinge lugs 2A and 3A of the upper and lower front pipes 2F and 3F, respectively. It is connected freely. Reference numeral 14 denotes a disc spring.
On the other hand, as shown in FIG. 4 and FIG. 6, for the folding lock mechanism portion arranged facing the folding rotation shaft portion of FIG. 5 in the vehicle transverse direction, the hinge fixing bolt 9 is a pipe constituting the truss. The reinforcing member 11 is concentrically installed and is joined to the hinge lugs 2B and 3B of the upper and lower rear pipes 2R and 3R of the rear front frame F2. Then, the lower pipe side lock portion 17 is locked by the screw engagement with the hinge lug 3A in the lower front pipe 3F of the screw portion at the lower end of the folding hinge fixing bolt 9, and the hinge lugs 2B and 3B of the rear pipes 2R and 3R are The upper and lower front pipes 2F and 3F are fastened to the hinge lugs 2A and 3A, respectively. At this time, as shown in FIG. 6, the locking recess 2 </ b> C of the hinge lug 2 </ b> A in the upper front pipe 2 is locked to the outer periphery of the folding hinge fixing bolt 9, so that the screw portion at the lower end of the folding hinge fixing bolt 9 is It is comprised so that it may align with the screw hole of the hinge lug 3A in the lower front pipe 3F. Reference numeral 15 denotes a lock cap that prevents the folding hinge fixing bolt 9 and the hinge lug 2A from being separated from each other in the upper pipe side lock portion 16.
[0013]
Thus, as shown in FIGS. 4 and 6, in the lock mechanism portion, the screw portion at the lower end portion of the hinge fixing bolt 9 is screwed from the hinge lugs 3A and 3B at the end portions of the lower pipes 3F and 3R by the rotation of the lever 13. By releasing the tightening, the upper front pipe 2F and the upper rear pipe 2R and the lower front pipe 3F and the lower rear pipe 3R can be separated and folded as shown in FIG.
[0014]
FIG. 9 is an explanatory diagram of the buffering efficiency and the like in the folding frame with the rear wheel shock absorber according to the present invention. In the present invention, a suspension mechanism in which the rear frame R, which forms a relatively small triangle with the rear end portion of the upper rear pipe 2R extending rearward of the standing pipe 4 as a swing center, swings up and down. Therefore, the unsprung load is small and the weight is reduced. Further, since the upper chain, which is the pulling side of the drive chain, and the pivot shaft 5 are close to each other, even if the chain tension fluctuates, the rotational moment to the rear frame R around the pivot shaft 5 can be greatly affected. Therefore, there is almost no power loss when driving the chain, and when riding, the frame descends due to the weight of the passenger and the pulling side chain and the pivot shaft 5 tend to be closer, so it is more effective against power loss. In addition, even when the suspension is cushioned, the fluctuation of the rear center with respect to the direction of impact input to the rear wheels can be small, and the influence of elongation on the drive chain can be minimized.
As shown in the figure, the swing axis position of the rear frame R is relative to the impact input F that is input to the rear wheel, which is the resultant force of the rearward force due to running resistance or the like and the vertical impact force from the road surface. Since it can be made substantially vertical, the rear frame R swings in the same direction as the impact input direction with the pivot shaft 5 as the swing axis when the rear wheel is stepped over, etc., and can efficiently perform shock absorbing action. .
[0015]
Although one embodiment of the present invention has been described above, within the scope of the present invention, the shape of the front frame and the rear frame, the swinging form by the pivot shaft between them, the type of shock absorber arrangement, etc. The arrangement of the reinforcing members in the front frame, the type of the folding rotation shaft portion, the type of the folding lock mechanism portion, and the like can be selected as appropriate. Note that the frame of the present invention may be provided with either the folding mechanism or the rear wheel cushioning mechanism in the front frame, or may have both of them.
[0016]
【The invention's effect】
As described above in detail, according to the present invention, the folding rotation shaft and the folding lock mechanism can be arranged concentrically with the truss-shaped reinforcing member that constitutes the frame, and the upper, lower, left, and right sides of the front frame can be arranged. Not only does it cause a decrease in the rigidity of the frame in the folded part even when the direction is twisted, but the folded hinge part is not conspicuous, the appearance is very good, and the appearance is excellent.
In addition, the folding rotation shaft and the folding lock mechanism having such a good appearance and simple structure are opposed to each other and independently installed on both sides of the vehicle body, so that each of them can surely perform a holding function. It is possible to securely hold the running state of the frame, and the upper and lower pipes constituting the front frame are configured to have a slightly larger and substantially flat cross-sectional shape, and a plurality of truss-like shapes stretched between them. The rigidity of the frame itself is also improved by employing a highly rigid front frame in which the reinforcing member is made of a pipe thinner than the upper and lower pipes.
Moreover, since the rear frame, which forms a relatively small triangle with the rear end of the upper rear pipe extending behind the standing pipe as the center of oscillation, is a suspension mechanism that swings up and down, the unsprung load Will be smaller and lighter.
[0017]
In addition, since the tension side chain in the drive chain and the pivot shaft are close to each other, even if the chain tension changes, the rotational moment to the rear frame around the pivot shaft is not greatly affected. There is little power loss at the time of riding, and when riding, the frame descends due to the weight of the passenger and the pulling side chain and the pivot shaft tend to be closer, so it is more effective against power loss, and even when the suspension is buffered The variation of the rear center with respect to the direction of impact input to the rear wheel can be small, and the influence of elongation on the drive chain can be minimized.
In addition, the rear frame's swing axis position can be made substantially perpendicular to the impact input that is input to the rear wheel, which is the resultant force of the backward force caused by the strike resistance and the vertical impact force from the road surface. When overcoming a step by a wheel, the rear frame swings in the same direction as the impact input direction with the pivot shaft as the swing axis, so that the shock can be absorbed efficiently.
Furthermore, shock absorbers etc. in the shock absorber are built into the cylinder that forms part of the frame, so that they are reliably protected, there is little risk of ozone degradation, etc., and the shock absorbing performance is maintained for a long time. You can also.
[Brief description of the drawings]
FIG. 1 is an overall side view of a bicycle in a traveling state of a folding frame with a rear wheel shock absorber according to the present invention.
FIG. 2 is an overall side view of a bicycle in a folded state of a folding frame with a rear wheel shock absorber according to the present invention.
FIGS. 3A and 3B are an overall assembly view and an exploded overall view of only a folding frame with a rear wheel shock absorber according to the present invention. FIGS.
FIG. 4 is a cross-sectional view of a folding lock mechanism portion of a folding frame with a rear wheel shock absorber according to the present invention.
FIG. 5 is a cross-sectional view of a folding rotation shaft portion of a folding frame with a rear wheel shock absorber according to the present invention.
FIG. 6 is a cross-sectional view showing a state in which a folding lock mechanism portion of a folding frame with a rear wheel shock absorber according to the present invention is separated.
FIG. 7 is a cross-sectional view of a shaft support portion of a front frame and a rear frame in a folding frame with a rear wheel shock absorber according to the present invention.
FIG. 8 is a sectional view of the shock absorber in the folding frame with the rear wheel shock absorber according to the present invention.
FIG. 9 is an explanatory diagram of buffering efficiency and the like in a folding frame with a rear wheel shock absorber according to the present invention.
FIG. 10 is a diagram for explaining a folding part in a conventional folding bicycle.
[Explanation of symbols]
F front frame F1 front front frame F2 rear front frame R rear frame 1 head pipe 2 upper pipe 2A hinge lug 2B hinge lug 2C locking recess 2F upper front pipe 2R upper rear pipe 3 lower pipe 3A hinge lug 3B lower front pipe 3R lower rear Pipe 4 Vertical pipe 5 Pivot shaft 6 Truss-like reinforcing member 7 Chain stay 8 Hanger pipe 9 Hinge fixing bolt 10 Folding rotation shaft 10A Shoulder bolt 11 Reinforcing member 12 Reinforcing member 13 Lever 19 Back fork 20 Si cylinder 22 Shock absorber 24 Movable rod 25 Stopper rubber 26 Rod end 27 Bolt 36 Tube part 37 Screw cap

Claims (8)

  The middle of the front frame that is constructed by joining the head pipe and the standing pipe with the hanger pipe joined to the lower end with the upper and lower pipes, and a plurality of truss-like reinforcing members are stretched between the upper and lower pipes A bicycle frame, wherein the portion is configured to be foldable by a substantially vertical folding rotation shaft, wherein the folding rotation shaft is concentric with the truss-shaped reinforcing member.   The folding part of the intermediate part of the front frame that constitutes a part of a plurality of truss-like reinforcing members is composed of a pair of left and right pipe-like reinforcing members, and one of these reinforcing members constitutes a folding rotation shaft The bicycle frame according to claim 1, wherein the other constitutes a folding lock mechanism.   3. The bicycle according to claim 2, wherein one of a pair of reinforcing members constituting each of the folding rotation shaft and the folding lock mechanism is joined to the front front frame and the other is joined to the rear front frame. flame. The upper and lower pipes constituting the front frame are configured to have a substantially flat cross-sectional shape, and a plurality of truss-like reinforcing members stretched therebetween are formed by pipes thinner than the upper and lower pipes. Item 4. The bicycle frame according to any one of Items 1 to 3.   The upper part of the front frame is constructed by joining the head pipe and the standing pipe with the hanger pipe joined to the lower end at the upper and lower pipes, and a plurality of truss-like reinforcing members are stretched between the upper and lower pipes. A pipe is extended to the rear of the upright pipe, and the front upper apex of the substantially triangular rear frame is pivotally supported at the rear end thereof, and the front lower apex of the rear frame is arranged behind the hanger pipe of the front frame. A frame with a rear wheel shock absorber, which is connected to a shock absorber installed.   6. The frame with a rear wheel shock absorber according to claim 5, wherein a shock absorber in the shock absorber is built in a cylinder constituting a part of a frame installed behind the hanger pipe. The frame with a rear wheel shock absorber according to claim 5 or 6, wherein a shock absorber in the shock absorber is made of a compressed rubber elastomer divided into a plurality of portions in the axial direction.   The middle of the front frame that is constructed by joining the head pipe and the standing pipe with the hanger pipe joined to the lower end with the upper and lower pipes, and a plurality of truss-like reinforcing members are stretched between the upper and lower pipes In a bicycle frame configured to be foldable by a substantially vertical folding rotation shaft, the folding rotation shaft is concentric with the truss-shaped reinforcing member, and the upper pipe of the front frame is a vertical pipe. The rear upper end of the substantially triangular rear frame is pivotally supported at the rear end thereof, and the front lower apex of the rear frame is disposed at the rear of the hanger pipe of the front frame. A folding frame with a rear wheel shock absorber connected to the device.

Images