CN114309487A - Bicycle frame integrated casting internal mold structure with hollow structure and forming preparation method - Google Patents

Abstract

The invention discloses a bicycle frame integrated casting forming die with a hollow structure, which comprises an upper die, a lower die and an inner die, wherein the inner die is arranged between the upper die and the lower die; the integrated bicycle frame is formed by liquid high-pressure casting or semi-solid casting, and comprises a head tube, an upper tube, a lower tube, a five-way tube, a middle tube, a rear upper fork and a rear lower fork; go up mould and lower mould and be equipped with the die cavity that connects in integrative top tube, headstock pipe, low tube, five-way pipe, well pipe, back upper fork and back lower fork that sets up according to bicycle frame structure, adopt the lock mode to merge into a metal die cavity whole, shaping back frame headstock pipe, top tube, low tube, five-way pipe, well pipe, back upper fork and back lower fork have the cavity inner chamber of mutual intercommunication, have central axis separately to nonparallel each other. Meanwhile, the method for manufacturing the integrated bicycle frame avoids strength reduction and welding quality defects caused by welding, and is suitable for batch production and integrated manufacturing of hollow bicycle frames.

Description

Bicycle frame integrated casting internal mold structure with hollow structure and forming preparation method

Technical Field

The invention relates to the field of bicycle frame preparation, in particular to a bicycle frame integrated casting internal mold structure with a hollow structure and a molding preparation method.

Background

The bicycle frame is an integral structure of the bicycle frame which is prepared by adopting an extrusion pipe in a welding connection mode all the time due to the size and the complex structure of the required pipe. The quality of the frame is often unstable due to the welding method, such as weld bead cracks and heat affected zone cracks, and even insufficient weld bead strength and welding defects due to poor control of the welding process. Furthermore, the frame formed by welding has many welding positions, the production steps are complicated, and the production efficiency is not high.

First, because the frame is in a closed type and a multi-pipe shape, part of the pipe is not easy to be made into a hollow shape, for example, the front support, the rear support, the lower fork and other parts of the frame mentioned in patent CN112046665A are all solid structures, and the inner mold is in an open type split shape, and is not closed, thereby further limiting the performance of the cast frame, and the dead weight of the frame is difficult to be reduced. CN112935217A forms head tube core, five-way core, well tube core, top tube core and low tube core combination, but adopts integrated configuration easily to cause stress concentration in frame thickness control, and is difficult to carry out further attenuate to the frame tube wall thickness because of the metal liquid mobility is relatively poor in the casting process, leads to the dead weight increase.

Disclosure of Invention

In order to solve the problems, the application provides a bicycle frame integrated casting internal mold structure with a hollow structure and a forming preparation method, so that the strength reduction and the welding quality defects caused by welding are avoided, and the bicycle frame integrated casting internal mold structure is suitable for batch production and integrated preparation of hollow frames.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a bicycle frame integrated casting forming die with a hollow structure comprises an upper die, a lower die and an inner die, wherein the inner die is arranged between the upper die and the lower die; the integrated bicycle frame is formed by liquid high-pressure casting or semi-solid casting, and comprises a head tube, an upper tube, a lower tube, a five-way tube, a middle tube, a rear upper fork and a rear lower fork; the upper die and the lower die are provided with die cavities which are arranged according to the structure of a bicycle frame and connected with an integrated upper tube, a head tube, a lower tube, a five-way tube, a middle tube, a rear upper fork and a rear lower fork, the die cavities are combined into a metal die cavity whole in a buckling mode, and the head tube, the upper tube, the lower tube, the five-way tube, the middle tube, the rear upper fork and the rear lower fork of the formed rear bicycle frame are provided with hollow inner cavities which are communicated with each other, have central axes of the upper tube and the lower tube, and are not parallel to each other.

Furthermore, the inner die is a sand die or a metal die, and the upper die and the lower die are metal dies.

Furthermore, the head tube is connected to the front ends of the upper tube and the lower tube, the middle tube is used as a middle shaft seat and is respectively connected with the rear end of the upper tube, the rear end of the lower tube, the rear upper fork and the rear lower fork (14), and the rear hook claw is connected with the hollow frame into an integral structure in a gluing connection or mechanical connection mode.

According to the method for preparing the integrated bicycle frame by using the casting forming die, the frame is made of aluminum alloy or magnesium alloy, the forming mode is an aluminum alloy or magnesium alloy metal melt, and the aluminum alloy or magnesium alloy metal melt is injected into a metal model cavity in a high-pressure casting or semi-solid casting mode and is cooled, solidified and formed;

the method specifically comprises the following steps:

step 1, placing an integrated multi-axial bicycle inner mold into a lower mold, and fixing the integrated multi-axial bicycle inner mold on the mold through a supporting point, wherein the supporting point is designed into an integrated structure with an inner membrane;

step 2, closing the die, combining the upper die and the lower die into a metal die cavity whole according to matching;

step 3, casting and molding, namely continuously injecting the metal liquid or the semi-solid metal melt into the die cavity through an injection hole under the action of pressure, and solidifying and molding the liquid metal or the semi-solid metal melt in the die cavity;

and 4, demolding, namely opening the upper mold and the lower mold, leading out the molding sand or drawing out the metal mold cavity, and taking out the integrally molded bicycle frame casting with the hollow structure.

The invention has the beneficial effects that:

the main structure of the bicycle frame is integrally formed by casting, so that the phenomenon of frame strength reduction or welding quality defect caused by necessary welding procedures in the traditional process is avoided, and the bicycle frame is suitable for industrial mass production. Meanwhile, the frame formed by the technology is of an integrated hollow structure, has an excellent weight reduction effect, and is more uniform in wall thickness and more stable in quality compared with the current process and the reported forming mode, and the integrated hollow structure and the integrated forming of the frame are realized.

Drawings

FIG. 1 is a schematic view of an integral casting mold of the present invention;

FIG. 2 is a schematic view of a bicycle frame of the hollow structure of the present invention;

FIG. 3 is a schematic view of the hollow structure and position of the frame of the present invention;

in the figure: 1-upper mould; 2-lower mould; 3-an inner mold; 4-a support point; 5-molten metal; 6-inner pouring channel; 7-an integrated multi-axial inner mold structure; 8-middle tube; 9-upper pipe; 10-a headstock tube; 11-lower tube; 12-a five-way pipe; 13-rear upper fork; 14-rear lower fork; 15-rear hook claw.

Detailed Description

The invention is further illustrated by the following examples in connection with the accompanying drawings.

Example one

As shown in fig. 1

A bicycle frame comprises a head tube 10, an upper tube 9, a lower tube 11, a five-way tube 12, a middle tube 8, a rear upper fork 13 and a rear lower fork 14; the head tube 10 is connected to the front ends of an upper tube 9 and a lower tube 11, and a middle tube 8 serving as a middle shaft seat is respectively connected to the rear end of the upper tube 9, the rear end of the lower tube 11, a rear upper fork 13 and a rear lower fork 14; the head tube, the upper tube, the lower tube, the five-way tube, the middle tube, the rear upper fork and the rear lower fork are provided with hollow inner cavities which are communicated with each other, have respective central axes and are not parallel to each other. The rear upper fork and the rear lower fork are connected through a rear hook claw 15.

The frame is made of aluminum alloy or magnesium alloy, the forming mode is aluminum alloy or magnesium alloy metal melt, the metal melt is cast into the metal mold cavity under the action of pressure after being processed, and the metal melt is cooled, solidified and formed.

The casting forming die for preparing the bicycle frame is a closed die cavity structure with an inner die structure and comprises an upper die 1, a lower die 2 and an inner die 3, wherein the inner die 3 is arranged between the upper die 1 and the lower die 2; the inner die 3 is a sand die or a metal die, the upper die 1 and the lower die (2) are metal dies, and cast iron or alloy steel can be selected as the material for prolonging the service life of the dies. The upper die 1 and the lower die 2 are respectively provided with an upper tube, a head tube, a lower tube, a five-way tube, a middle tube, a rear upper fork and a rear lower fork which are arranged according to the structure of the bicycle frame and connected into a whole, and are combined into a metal die cavity whole in a buckling mode; the inner mold 3 is provided with an integrated multi-axial inner mold structure of an upper tube, a head tube, a lower tube, a five-way tube, a middle tube, a rear upper fork and a rear lower fork which are arranged according to the bicycle structure, and the inner mold 3 is of a closed geometric structure; the multiaxial direction refers to each component of the inner mold, including an upper tube, a head tube, a lower tube, a five-way tube, a middle tube, a rear upper fork and a rear lower fork, wherein 7 components have respective central axes and are not parallel to each other. Centre form 3 sets up strong point 4 in well pipe upper end, five-way pipe, headstock pipe, back upper fork rear end, back lower fork rear end department, and the centre form is arranged in and is gone up mould, the closed cavity intermediate position of lower mould, and this design not only can prevent to cause the frame wall thickness difference to appear after the casting is accomplished because of the centre form skew that the gravity difference leads to, can avoid the combination dimensional tolerance that the multimode spare adopted the combination design to cause in addition, influences frame size precision. And 3-5 molten metal ingates 5 matched with each other are designed on the inner walls of the upper die 1 and the lower die 2, molten metal injection holes are formed after die assembly, and liquid metal uniformly flows into the die cavity through the injection holes to be solidified and molded.

The method for manufacturing the integrated bicycle frame with the hollow structure by the technical scheme comprises the following steps:

step 1, placing an integrated multi-axial bicycle inner mold into a lower mold, and fixing the integrated multi-axial bicycle inner mold on the mold through a supporting point, wherein the supporting point is designed into an integrated structure with an inner membrane;

step 2, closing the die, combining the upper die and the lower die into a metal die cavity whole according to matching;

step 3, casting and molding, namely continuously injecting the metal liquid or the semi-solid metal melt into the die cavity through an injection hole under the action of pressure, and solidifying and molding in the die cavity;

step 4, demoulding, namely opening the upper mould and the lower mould, leading out the molding sand or drawing out the metal cavity, and taking out the obtained integrally-formed bicycle frame casting with the hollow structure;

and 5, connecting the rear hook claw with the bicycle rear hook claw by adopting a gluing connection or mechanical connection mode to form an integral structure with the hollow frame.

It should be noted that the above-mentioned embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.

Claims (4)

1. A bicycle frame integrated casting forming die with a hollow structure comprises an upper die (1), a lower die (2) and an inner die (3), wherein the inner die (3) is arranged between the upper die (1) and the lower die (2); the integrated bicycle frame is formed by liquid high-pressure casting or semi-solid casting, and comprises a head tube (10), an upper tube (9), a lower tube (11), a five-way tube (12), a middle tube (8), a rear upper fork (13) and a rear lower fork (14); the method is characterized in that: go up mould (1) and lower mould (2) be equipped with according to the die cavity of the last pipe, headstock pipe, low tube, five-way pipe, well pipe, back upper fork and back lower fork of connection in an organic whole that bicycle frame structure set up, adopt the lock mode to merge into a metal die cavity whole, the frame after the shaping headstock pipe, last pipe, low tube, five-way pipe, well pipe, back upper fork and back lower fork have the cavity inner chamber of mutual intercommunication, have central axis separately to nonparallel each other.

2. The casting mold according to claim 1, wherein the inner mold (3) is a sand mold or a metal mold, and the upper mold (1) and the lower mold (2) are metal molds.

3. The integrated bicycle frame according to claim 1, characterized in that the head tube (10) is connected to the front ends of the upper tube (9) and the lower tube (11), the middle tube (8) is used as a middle shaft seat to be respectively connected to the rear end of the upper tube (9), the rear end of the lower tube (11), the rear upper fork (13) and the rear lower fork (14), and the rear hook claw (15) is connected with the hollow bicycle frame by gluing or mechanical connection to form an integrated structure.

4. A method for manufacturing an integrated bicycle frame by using the casting and forming die as claimed in claim 1, is characterized in that the frame is made of aluminum alloy or magnesium alloy, the forming mode is aluminum alloy or magnesium alloy metal melt, the aluminum alloy or magnesium alloy metal melt is injected into a metal mold cavity in a high-pressure casting or semi-solid casting mode, and the aluminum alloy or magnesium alloy metal melt is cooled, solidified and formed;

the method specifically comprises the following steps:

step 1, placing an integrated multi-axial bicycle inner mold into a lower mold, and fixing the integrated multi-axial bicycle inner mold on the mold through a supporting point, wherein the supporting point is designed into an integrated structure with an inner membrane;

step 2, closing the die, combining the upper die and the lower die into a metal die cavity whole according to matching;

step 3, casting and molding, namely continuously injecting the metal liquid or the semi-solid metal melt into the die cavity through an injection hole under the action of pressure, and solidifying and molding the liquid metal or the semi-solid metal melt in the die cavity;

and 4, demolding, namely opening the upper mold and the lower mold, leading out the molding sand or drawing out the metal mold cavity, and taking out the integrally molded bicycle frame casting with the hollow structure.

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