Lightweight carbon fiber crank structure

Abstract

The utility model discloses a light-weight carbon fiber crank structure which structurally comprises cranks arranged at the two ends and made of light-weight carbon fibers, an integrated crank connecting shaft of a double-end replacement structure is arranged in the middle of each crank, and the integrated crank connecting shaft comprises a matching head and a spline end which are arranged at the two ends and integrally machined. During assembly, the matching head part is embedded into the slotted hole of the crank at one end, the spline end part is sleeved and matched with the glued spline sleeve, the glued spline sleeve is mounted in the slotted hole of the crank at the other end, and the cranks at the two ends are fixedly mounted on the integrated crank connecting shaft. The crank is made of light carbon fibers, the overall weight is reduced, the replaceable integrated crank connecting shaft is adopted, the crank connecting shaft is made of carbon fiber materials or light aluminum alloy materials preferentially, the effects of being light in dead weight, better in rigidity and higher in strength can be achieved, assembly is more convenient, and the service life of the crank is prolonged. And meanwhile, component combination is reduced, and the wear rate is reduced.

Description

Technical Field

[0001] The utility model relates to the field of bicycles, and particularly to a lightweight carbon fiber crank structure. Background Art

[0002] Bicycles are not only a part of people's means of transportation in life, but cycling has also become a way of life in the increasingly rich lifestyle. And competitive cycling races are more a manifestation of the spirit of hard work and unity. The crank is an important part of the transmission part in a bicycle.

[0003] During the cycling process, after a long time of cycling and pedaling by the rider, the bicycle crank is prone to deformation due to material problems, resulting in a decrease in structural strength. Once the structural strength decreases, it will affect cycling safety. Therefore, the structural strength of the bicycle crank is particularly important.

[0004] Generally, the cranks on the market adopt two plum blossom glued keys and an axle connecting piece, so that there are two lap joints between the axle center and the plum blossom key, and both ends are locked with fastening screws, thus increasing the weight. Just like a lightweight carbon fiber bicycle crank with the patent number CN219750066U in the prior art, its structure includes a crank, a crank connecting shaft, and a connecting fastening component. The crank is formed by carbon fiber hollow blowing molding process. The crank is installed at the upper and lower ends of the crank connecting shaft. One end of the crank is clamped at both ends of the crank connecting shaft through the connecting fastening component. The two ends of the crank connecting shaft are provided with first spline shafts. A second spline shaft is provided below the first spline shaft provided at the upper end of the crank connecting shaft. A first limit retaining piece is provided at the bottom of the second spline shaft. This patent solution has the following problems: the self-weight of the block-fastening type crank is relatively large, and the heavier the accessories, the greater the physical strength the rider needs to consume to increase the speed; moreover, the more components are assembled, the longer the assembly time, and it is easy to cause accidental wear between the crank and the connecting shaft during use. After the worn crank and connecting shaft are assembled and used continuously, the service life is likely to be reduced.

[0005] Therefore, in order to solve the problems existing in the prior art, the utility model provides a lightweight carbon fiber crank structure. Content of the Utility Model

[0006] The main purpose of the utility model is to overcome the deficiencies of the prior art and provide a lightweight carbon fiber crank structure.

[0007] The utility model is implemented by the following technical scheme: a lightweight carbon fiber crank structure, which includes cranks made of lightweight carbon fiber and arranged at both ends, an integrated crank connecting shaft with a double-head replacement structure is arranged in the middle of the crank, and the integrated crank connecting shaft includes a mating head and a spline end that are integrally processed and arranged at both ends; during assembly, the mating head is embedded in a slot hole of the crank at one end, the spline end is sleeved and matched with a glued spline sleeve, and the glued spline sleeve is installed in the slot hole of the crank at the other end, and the cranks at both ends are fastened to the integrated crank connecting shaft.

[0008] Furthermore, the mating head is provided with a plum blossom-shaped groove mating with the crank; during assembly, the crank is pressed into the mating head and then screwed into the limiting cover plate for locking, thereby achieving a tightening effect.

[0009] Furthermore, one side of the limiting cover plate is provided with an external thread, and the inner groove of the matching head is provided with an internal thread matching the external thread, so that the tightening effect is achieved by means of threaded connection.

[0010] Furthermore, a limiting baffle for locking is provided below the mating head, which effectively limits the position of the crank at one end.

[0011] Furthermore, a hoop ring is sleeved below the limit baffle, and the length of the longest end extension section of the hoop ring is greater than the radius of the limit baffle on the same side, so that a further limiting effect is achieved by providing the hoop ring.

[0012] Furthermore, the clamp ring adjusts the tension during clamping by means of a locking bolt, and the tension of the clamp is adjusted by an external locking bolt, that is, a structural member composed of a bolt and a nut, for better operation.

[0013] Furthermore, the integrated crank connecting shaft is an integrated shaft made of a lightweight carbon fiber material or an integrated shaft made of a lightweight aluminum alloy material. By setting the lightweight carbon fiber material and the lightweight aluminum alloy material, the weight of the overall structure is reduced and the riding difficulty of the rider is reduced.

[0014] Furthermore, a fastening grab disc sleeve for limiting position is provided at the junction of the spline end and the glued spline sleeve, and the outer diameter range of the fastening grab disc sleeve is not less than the outer diameter range of the glued spline sleeve, thereby further achieving the limiting effect of the crank at the other end.

[0015] Furthermore, a tapered piece is provided in the middle of the fastening grab disc sleeve in the direction of the glued spline sleeve.

[0016] Furthermore, the inner wall of the glued spline sleeve is provided with an arc angle transition to facilitate better cooperation with the integrated crank connecting shaft.

[0017] Further, during assembly, the outer end of the glued spline sleeve is screwed inwards into the limit cover plate. The limit cover plate is provided with an external thread, which is matched with the internal thread at the outer end of the glued spline sleeve.

[0018] Further, an installation groove is provided in the middle of the limit cover plate. A locking bolt is screwed into the installation groove. The end of the locking bolt extends into the inside of the spline end and is threadedly matched with the spline end, further strengthening the connection between the non-integrated glued spline sleeve and the integrated crank connecting shaft.

[0019] Further, a taper transition is adopted at the junction of the integrated crank connecting shaft and the glued spline sleeve. Setting the taper transition is beneficial to reducing stress.

[0020] Compared with the prior art, the beneficial effects of the present utility model are as follows: The crank of the present utility model is made of lightweight carbon fiber, reducing the overall weight. The replaceable integrated crank connecting shaft is preferably made of carbon fiber or lightweight aluminum alloy material in terms of the material of the crank connecting shaft, which can achieve the effects of lighter self-weight, better rigidity and higher strength; this makes it easier for cyclists and reduces physical consumption.

[0021] Moreover, the integrated crank connecting shaft design in the present utility model results in fewer joints, lighter natural weight, less stress and more convenient assembly. At the same time, it reduces the component joints and the wear rate, thus making cycling safer and more comfortable. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present utility model.

[0023] Figure 2 It is Figure 1 the front view of

[0024] Figure 3 The internal structure sectional view of the present utility model.

[0025] Figure 4 It is a schematic diagram of the separated structure of the present utility model.

[0026] Figure 5 It is a schematic diagram of the separated structure of the present utility model from another angle.

[0027] Figure 6 It is a three-dimensional enlarged structure schematic diagram of the integrated crank connecting shaft part of the present utility model.

[0028] Figure 7 It is Figure 6 the top view of

[0029] In the figure: limit cover plate 1, locking bolt 2, crank 3, glued spline sleeve 4, fastening chuck sleeve 5, integrated crank connecting shaft 6, mating head 61, spline end 62, limit retaining plate 63, hoop ring 7, locking bolt member 71. Specific embodiments

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] Please refer to Figures 1-7 , the present invention provides a technical solution for a lightweight carbon fiber crank structure: a lightweight carbon fiber crank structure, the structure of which includes cranks 3 made of lightweight carbon fiber provided at both ends, and an integrated crank connecting shaft 6 with a double-headed replacement structure is provided in the middle of the crank 3. It should be noted that the double-headed replacement structure means that the fastening and replacement of the crank 3 can be realized on both sides of the integrated crank connecting shaft 6, which is convenient to achieve the effect of quick disassembly. The integrated crank connecting shaft 6 includes mating heads 61 and spline ends 62 that are integrally processed at both ends; during assembly, the mating head 61 is fitted into the slot of one end of the crank 3, and the mating head 61 is provided with a plum blossom-shaped slot that mates with the crank 3. After the crank 3 is pressed into the mating head 61, the limit cover plate 1 is screwed in for locking. It should be noted that in the present invention, the limit cover plate 1 achieves the fastening effect by means of threaded connection. Therefore, an external thread is provided on one side of the limit cover plate 1, and an internal thread matching it is provided in the inner groove of the mating head 61, but the use of snap or snap connection is not excluded. The same applies below;

[0032] In addition, the spline end 62 is sleeved and fitted with the glued spline sleeve 4. The glued spline sleeve 4 is installed in the slot hole of the other crank 3. The cranks 3 at both ends are fixedly installed on the integral crank connecting shaft 6. A fastening chuck sleeve 5 for limiting is provided at the junction of the spline end 62 and the glued spline sleeve 4 to facilitate the limiting and fixing of the other crank 3. The outer diameter range of the fastening chuck sleeve 5 is not less than the outer diameter range of the glued spline sleeve 4. During assembly, the outer end of the glued spline sleeve 4 is screwed inward into the limiting cover plate 1. The limiting cover plate 1 is provided with an external thread, and the external thread is matched with the internal thread at the outer end of the glued spline sleeve 4. To better achieve the reinforcement effect, an installation groove is provided in the middle of the limiting cover plate 1, and a locking bolt 2 is screwed into the installation groove. The end length of the locking bolt 2 extends into the interior of the spline end 62 and is threadedly matched with the spline end 62, which facilitates the locking bolt 2 to pass through the spline end 62 and locks and fixes the limiting cover plate 1, the other crank 3, and the glued spline sleeve 4.

[0033] See the appendix Figures 4-6 Below the mating head 61, a limiting tab 63 for positioning is provided to facilitate the limiting of the crank 3. To achieve a further effect, a hoop ring 7 is sleeved below the limiting tab 63. The length of the longest end extension of the hoop ring 7 is greater than the radius of the limiting tab 63 on the same side. At the same time, to facilitate the adjustment of the tension of the hoop ring 7 and prevent the parts from being irreplaceable, the hoop ring 7 is adjusted by cooperating with a locking bolt member 71;

[0034] To better reduce the weight of the overall structure, the integral crank connecting shaft 6 is an integral shaft made of lightweight carbon fiber material or an integral shaft made of lightweight aluminum alloy material, which can reduce the overall weight and facilitate better use.

[0035] When the lightweight carbon fiber crank structure is used, the integral crank connecting shaft in the middle adopts a lightweight carbon fiber integral shaft or a lightweight aluminum alloy integral shaft to achieve the effect of double replacement. The two ends adopt lightweight carbon fiber cranks, carbon fiber integral shafts or aluminum alloy integral shafts. It should be noted that a carbon fiber integral shaft is preferably used (this will be used as an example hereinafter). The glued spline sleeve and other fasteners for connection together form this solution. Glue one end of the carbon fiber crank and the glued spline sleeve with cold glue as one side, and this side is the fixed side; the plum blossom shape on the outside of the glued spline sleeve on the fixed side is consistent with the plum blossom groove on the carbon fiber central shaft, so that they are tightly fitted and assembled; the other crank is installed on the plum blossom shape of the mating head in the carbon fiber integral shaft, and the outside is locked tightly with a limiting cover plate. Among them, the central shaft of the carbon fiber integral shaft is locked tightly by the limiting cover plate and is no longer glued and fixed, so as to achieve replaceability;

[0036] Among them, the carbon fiber integrated shaft center and the glued spline sleeve are combined into one body, and a taper transition is adopted at the joint to reduce the stress. In addition, a taper piece is provided in the middle of the fastening chuck sleeve that cooperates with it, and the inner wall of the glued spline sleeve has a guide arc transition to reduce the stress; the crank is made of carbon fiber to make its strength better and its rigidity stronger. In addition, the upper crank in the attached drawing is screwed in through a limit cover plate with an external thread to fasten the upper crank and the integrated crank connecting shaft.

[0037] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A lightweight carbon fiber crank structure, the structure comprising cranks (3) made of lightweight carbon fiber provided at both ends, characterized in that: In the middle of the crank (3), there is an integrated crank connecting shaft (6) with a double-headed replacement structure. The integrated crank connecting shaft (6) includes mating heads (61) and spline ends (62) which are integrally machined at both ends. During assembly, the mating head (61) is fitted into the slot of one end of the crank (3), and the spline end (62) is sleeved and mated with a glued spline sleeve (4). The glued spline sleeve (4) is installed in the slot of the other end of the crank (3), and the cranks (3) at both ends are firmly installed on the integrated crank connecting shaft (6). Below the mating head (61), there is a limit retaining piece (63) for positioning. Below the limit retaining piece (63), there is a hoop ring (7) sleeved. The length of the longest end extension of the hoop ring (7) is greater than the radius of the limit retaining piece (63) on the same side. The hoop ring (7) adjusts the tension during tightening through a locking bolt (71).

2. The lightweight carbon fiber crank structure according to claim 1, wherein: On the mating head (61), there is a plum blossom-shaped slot for mating with the crank (3). During assembly, after the crank (3) is pressed into the mating head (61), a limit cover plate (1) is screwed in for locking.

3. A lightweight carbon fiber crank structure according to claim 2, characterized in that: On one side of the limit cover plate (1), there is an external thread, and in the inner slot of the mating head (61), there is an internal thread matching it.

4. A lightweight carbon fiber crank structure according to any one of claims 1-3, characterized in that: The integrated crank connecting shaft (6) is an integrated shaft made of lightweight carbon fiber material or an integrated shaft made of lightweight aluminum alloy material.

5. The lightweight carbon fiber crank structure according to claim 4, wherein: At the junction of the spline end (62) and the glued spline sleeve (4), there is a fastening chuck sleeve (5) for limiting. The outer diameter range of the fastening chuck sleeve (5) is not less than the outer diameter range of the glued spline sleeve (4). At the intersection of the integrated crank connecting shaft (6) and the glued spline sleeve (4), a taper transition is adopted. In the middle of the fastening chuck sleeve (5) towards the direction of the glued spline sleeve (4), there is a taper piece. The inner wall of the glued spline sleeve (4) has an arc angle transition.

6. The lightweight carbon fiber crank structure according to claim 5, characterized in that: During assembly, the outer end of the glued spline sleeve (4) is screwed inwards with the limit cover plate (1). On the limit cover plate (1), there is an external thread, and the external thread is matched with the internal thread at the outer end of the glued spline sleeve (4).

7. The lightweight carbon fiber crank structure according to claim 6, wherein: In the middle of the limit cover plate (1), there is an installation slot. A locking bolt (2) is screwed into the internal thread of the installation slot. The end length of the locking bolt (2) extends to the inside of the spline end (62) and is threadedly mated with the spline end (62).

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