CN1438080A - Aluminum tube cold extrusion manufacturing method - Google Patents

Abstract

A manufacturing method of an aluminum pipe cold extrusion comprises the following steps: firstly, preparing at least one pipe: the pipe is made of aluminum alloy; secondly, shrinking the head: the pipe diameter of one end of the pipe is narrowed; thirdly, treating the skin membrane: coating a lubricant on the pipe; fourthly, cold extrusion treatment: preparing at least one eye mold and at least one mandrel, enabling the mandrel to extend into the pipe, pushing one end of the pipe subjected to head shrinking treatment to drive the pipe to pass through the mold eye of the eye mold, and forming the pipe into the required aluminum pipe. The invention can improve the strength of the aluminum pipe, improve the processing quality and the processing speed, effectively reduce the consumption of the aluminum material and reduce the manufacturing cost.

Description

Aluminum tube cold extrusion manufacturing method

【Technical field】

The invention relates to a manufacturing method for cold extrusion of an aluminum tube.

【Background technique】

Generally, aluminum alloys can be divided into two categories: heat-treated aluminum alloys and non-heat-treated aluminum alloys. These two aluminum alloys can be formed into aluminum tubes through extrusion (generally heated to 550°C), butt welding and other manufacturing methods. However, when the aluminum tubes of these two different materials are to be artificially strengthened, the following difficulties will be encountered:

1. Since non-heat-treated aluminum alloys can only be strengthened by cold rolling and cold forging, this kind of strengthening treatment is only applicable to plates or solid finished products, not to hollow aluminum tubes. Therefore, at present There is no effective way to artificially strengthen aluminum tubes of non-heat-treated aluminum alloys.

2. Although the aluminum tubes of heat-treated aluminum alloys can be strengthened by relevant heat treatment procedures (such as solution treatment, age hardening treatment, etc.), the strength of the aluminum tubes that can be improved by the heat treatment procedures is limited, and it will produce aluminum alloys. Tube deformation and dimensional instability problems.

In addition, in order to meet the relevant size and precision requirements, the above-mentioned aluminum tubes need to undergo subsequent mechanical processing, such as turning, grinding, etc. Although this can make these aluminum tubes meet the relevant size requirements, but this Waiting for mechanical processing will lead to the following defects:

1. Low processing accuracy, slow processing speed, and low processing stability: Since this kind of mechanical processing is processed by tools and abrasive tools, it is easy to reduce the processing accuracy due to processing errors, and the turning and grinding are originally equivalent. Labor-consuming and time-consuming processing. Therefore, with the increase of the length of the aluminum tube, the processing speed will be seriously slowed down. In addition, in the process of turning and grinding, the wear of tools and abrasives will cause processing Unstable quality, resulting in reduced processing stability.

2. High material consumption: Turning and grinding will consume a lot of aluminum tube materials. This will not only cause waste of materials, but also increase the cost of materials.

3. High inventory rate: Because the size changes that can be processed by turning and grinding are limited, and if the range of turning and grinding is too large, it will lead to a substantial increase in material costs. Therefore, the industry must stock a variety of different sizes. Aluminum tubes are used to facilitate related mechanical processing, which leads to an increase in the inventory rate and inventory cost of the industry.

4. Low design variability: It can be seen from the general vehicle manufacturing technology that when the length of the aluminum tube is more than five times the diameter of the aluminum tube, the in-tube process of the aluminum tube will cause technical difficulties. When the length is more than eight times the diameter of the aluminum tube, the aluminum tube's external lathing will also cause technical difficulties. Turning to the required wall thickness and cross-sectional shape.

5. Low surface luminosity: After the aluminum tube is generally machined and ground, its outer surface will be covered with knife marks. Production costs increase.

【Content of invention】

The object of the present invention is to provide a cold extrusion manufacturing method of aluminum tubes that can increase the strength of aluminum tubes, improve processing quality and processing speed, and reduce manufacturing costs.

In order to achieve the above object, the present invention provides a method for manufacturing aluminum pipe cold extrusion, characterized in that: the method comprises the following steps:

1. Prepare at least one pipe: the pipe is made of aluminum alloy;

2. Shrinking treatment: making the diameter of one end of the pipe smaller;

3. Film treatment: apply lubricant to the pipe;

4. Cold extrusion treatment: prepare at least one eye mold and at least one mandrel, make the mandrel extend into the pipe, push the end of the pipe that has been shrunk to drive the pipe through the eye of the eye mold, so that, The pipe can be formed into the required aluminum pipe.

The cold extrusion manufacturing method of the aluminum tube is characterized in that: the material of the tube in step 1 is a heat-treated aluminum alloy, and the tube has been subjected to solution treatment and age hardening treatment.

The manufacturing method of aluminum tube cold extrusion is characterized in that the lubricant used in step 3 can be a liquid lubricant or a solid lubricant.

The method for manufacturing the aluminum tube by cold extrusion is characterized in that in step 4, different eye molds and mandrels can be used in combination, so that the pipe can continuously pass through the holes of different eye molds, Furthermore, the pipe can be formed into the aluminum pipe with different wall thicknesses and different cross-sectional shapes.

Through the above description, the advantages of the present invention can be summarized as follows:

1. During the cold extrusion process in step 4, the crystal grains of the aluminum material 10 are forced to form a unidirectional fibrous structure. Therefore, after the aluminum material 10 is formed into the aluminum tube 40, the aluminum tube 40 The strength will be greatly improved, and it is better than the existing aluminum tube.

2. During the cold extrusion process in step 4, the strength of the aluminum tube 40 of the present invention will be greatly improved. Therefore, under the same safety standards, the aluminum tube 40 can achieve the purpose of lightweight design to save material usage. and reduce material costs.

3. In the cold extrusion process of step 4, the present invention uses the cooperation of the eye mold 20 and the mandrel 30 to form the aluminum material 10 into the aluminum tube 40 at one time, and utilizes the eye mold 20, The matching use of the mandrel 30 is also less prone to the problems of machining errors and wear than existing cutting tools and grinding tools. Therefore, the present invention has high machining speed, high machining accuracy and high machining stability.

4. The cold extrusion treatment in step 4 of the present invention belongs to the chipless cold process, so the present invention does not cause waste of materials, and can greatly reduce the cost of materials used.

5. The present invention utilizes the cooperation of different eye molds and mandrels to cold-extrude the aluminum material 10 into aluminum tubes of various thicknesses. Therefore, the manufacturer only needs to keep a small amount of the aluminum material 10 in stock, that is, Relevant molding can be carried out, so the present invention can reduce the inventory rate of the industry, and further reduce the inventory cost of the industry.

6. It can be seen from FIG. 5 that during the cold extrusion process in step 4, the present invention can simultaneously process the pipe wall thickness of the pipe 10 by using the eye molds and the mandrels with different sizes and shapes. and cross-sectional shape processing, therefore, the present invention will not produce the difficulties (especially in-tube forming processing) as in the existing car manufacturing technology, so the size limit of the aluminum tube formed by the present invention is small, and the aluminum tube can be arbitrarily made Long forming to the desired wall thickness and cross-sectional shape.

7. During the cold extrusion process in step 4, the inner and outer diameters of the aluminum material 10 are finely extracted synchronously to form a smooth surface. Therefore, the initially formed aluminum tube 40 has a more compact shape than the existing aluminum tube initially produced. Good surface gloss, so the surface gloss of the finished product of the present invention is even better.

In addition, it is worth mentioning that although the pipes made of non-heat-treated aluminum alloy are limited by their own material properties, the strength that can be improved after the relevant steps of the present invention is still limited, but, The present invention is still applicable to pipes made of non-heat-treated aluminum alloys.

Below in conjunction with accompanying drawing and embodiment the present invention is described in detail:

【Description of drawings】

Fig. 1 is a manufacturing flow chart of a better embodiment of the present invention.

Fig. 2 is a schematic diagram (1) of the cold extrusion process of the preferred embodiment.

Fig. 3 is a schematic diagram (2) of the cold extrusion treatment of the preferred embodiment.

Fig. 4 is a schematic diagram (3) of the cold extrusion treatment of the preferred embodiment.

Fig. 5 is a partially cutaway perspective view of a finished product of the preferred embodiment.

【Detailed ways】

Referring to Fig. 1, 2, 3, 4, a better embodiment of the present invention comprises the following steps:

1. Prepare a pipe 10: the pipe 10 is made of heat-treated aluminum alloy, and is formed by extrusion (heated to 550° C.), and the pipe 10 has been subjected to solution treatment and aging hardening after forming.

2. Shrinking treatment: making the diameter of one end of the pipe 10 smaller. This is a common common technology in the art, so it will not be described in detail.

3. Film treatment: apply a lubricant on the pipe 10, in this embodiment a liquid lubricant is used.

4. Cold extrusion treatment: prepare a die 20 and a mandrel 30, and at normal temperature, make the mandrel 30 extend into the pipe 10, and push the end of the pipe 10 that has been shrunk to drive the pipe 10 through the pipe. The mold eye 21 of the eye mold 20 is so that the pipe material 10 can be formed into a required aluminum pipe 40 after demoulding.

Thus, in step 1, the pipe material 10 has the same strength as the above-mentioned existing heat-treated aluminum alloy aluminum pipe, and in step 4, the aluminum material 10 is cooperated with the eye mold 20 and the mandrel 30 at normal temperature When extruded, the grains of the aluminum material 10 will be deformed along the processing direction and become elongated grains, and the direction of the grains will generally turn to the processing direction, that is to say, the structure of the aluminum material 10 will change. It becomes a directional structure, and when the aluminum material 10 is plastically deformed to a certain extent, the crystal grains of the aluminum material 10 will be divided due to sliding action, and the crystal lattice will be divided, and each part will become finer after turning. Long crystallization, so that the entire structure of the aluminum material 10 is fibrous, that is, the structure of the aluminum material 10 will eventually become a unidirectional fibrous structure, which is the perfect structure next to single crystals. Therefore, after molding, the The strength (physical properties) of the aluminum tube 40 will be greatly improved, (according to the inventor's actual test, the strength of the aluminum tube 40 will be improved by 40% to 50% compared with the existing aluminum tube), and, with the aluminum tube 40 and As the compression ratio between the aluminum materials 10 increases (the larger the compression ratio, the thinner the wall of the aluminum tube 40 is), the strength of the aluminum tube 40 will also increase proportionally. Therefore, under the same safety specification, the aluminum tube 40 can achieve the same strength as the existing aluminum tube with a thinner tube wall thickness. In this way, not only the purpose of lightweight design can be achieved, but also the use of materials can be saved and the cost of materials used can be reduced.

In addition, referring to Fig. 5, the present invention can make the pipe 10 pass through the holes of different eye molds continuously by using the eye molds of different sizes and shapes and the mandrel (not shown in the figure), so that The pipe material 10 can be formed into an aluminum pipe 50 having different pipe wall thicknesses and different cross-sectional shapes. As shown in FIG. 5 , the aluminum pipe 50 has a first pipe portion 51 and a second pipe portion 52. The tube wall thickness of the tube part 51 is greater than the tube wall thickness of the second tube part 52, and the internal cross-sectional shape of the first tube part 51 is a polygon, and the internal cross-sectional shape of the second tube part 52 is a circle. arc.

To sum up the above, the aluminum tube cold extrusion manufacturing method of the present invention can not only improve and increase the strength of the aluminum tube, but also improve the processing quality and processing speed, and can effectively reduce the consumption of aluminum materials and reduce the manufacturing cost, so it can indeed achieve the invention. the goal of.

Claims (5)

1. A manufacturing method for aluminum tube cold extrusion, characterized in that: comprising the following steps: (1), prepare at least one pipe: the pipe is a pipe made of aluminum alloy; (2) Shrinking treatment: make the pipe diameter at one end of the pipe smaller; (3) Film treatment: apply lubricant to the pipe; (4), cold extrusion treatment: prepare at least one eye mold and at least one mandrel, make the mandrel extend into the pipe, push the end of the pipe through the shrinkage treatment, to drive the pipe through the eye of the eye mold, The tube can be formed into the required aluminum tube. 2. The manufacturing method of aluminum tube cold extrusion according to claim 1, characterized in that: the material of the tube in step (1) is a heat-treated aluminum alloy, and the tube has been subjected to solution treatment and age hardening treatment. 3. The manufacturing method of aluminum tube cold extrusion as claimed in claim 1, characterized in that: the lubricant used in step (3) is a liquid lubricant. 4. The manufacturing method of aluminum tube cold extrusion as claimed in claim 1, characterized in that: the lubricant used in step (3) is a solid lubricant. 5. The manufacturing method of aluminum tube cold extrusion as claimed in claim 1, characterized in that: in step 4, using different eye molds and mandrels in combination, the tube can be continuously passed through different eyes The die hole of the mold, so that the pipe can be formed into the aluminum pipe with different wall thicknesses and different cross-sectional shapes at the same time.

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