A method for forming a special middle tube for a four-link

Abstract

The present invention relates to the technical field of bicycles, and in particular to a method for forming a special center tube for a four-link bicycle. The method provided by the present invention comprises the following steps: melting the raw material of the center tube in a smelting furnace under a protective gas state to obtain a casting liquid, then casting the raw material through an ingot mold to obtain an ingot, repeatedly hammering the raw material into an ingot, bending the ingot, and pouring the casting liquid at the connection of the bent band to obtain a tube body. The tube body is punched through upper and lower molds to obtain a primary center tube, and finally a quenching agent is applied to the surface of the tube, the tube is wrapped with tin foil, and the tube is quenched in a quenching furnace. The tin foil is then removed and the tube is water-cooled in water. The quenching and water-cooling are repeated to complete the forming of the center tube. The provided method is simple to operate, greatly improves the rigidity, hardness, wear resistance, fatigue strength and toughness of the center tube, extends the service life and performance of the center tube, and improves the quality of the formed center tube.

Description

Technical Field

[0001] The invention relates to the technical field of bicycles, and in particular to a method for forming a special middle tube for a four-link rod. Background Art

[0002] A bicycle, also known as a cycle or bike, is typically a small, two-wheeled land vehicle. It's powered by pedaling, making it an environmentally friendly means of transportation. There are many different types of bicycles, including single-person, tandem, and multi-person bicycles. They can be used as an environmentally friendly means of transportation and travel; more and more people are using bicycles as fitness equipment for exercise and cycling trips. Cycling itself is also a competitive sport, with events like road cycling, mountain biking, track cycling, and stunt biking. With the advancement of technology, electric bicycles have also become a common means of transportation.

[0003] The center tube is an important component of a bicycle. It generally refers to the tube in the middle of the frame. The front derailleur is installed on the center tube. Its main function is to determine the size of the frame. The patent application number CN202110639710.9 states in its specification that "by heating the steel strip and rolling it multiple times, the cracks generated during the rolling and rolling of the high-carbon chromium bearing steel strip can be reduced to produce a tube billet; finally, the obtained tube billet is welded to produce a steel pipe, which reduces the large number of cracks that are easily generated during the steel pipe forming process; that is, the steel pipe is prepared by a comprehensive method of continuous multiple rolling and welding. During the production and forming process of thin-walled high-carbon chromium bearing steel steel pipes, a large number of cracks can be reduced during the forming process of high-carbon chromium bearing steel steel pipes, and the cracking of high-carbon chromium bearing steel steel pipes during use can be reduced." Although the above patent can realize the forming of the center tube, it adopts a single rolling and welding method, and during the forming process, it effectively improves the rigidity, hardness, wear resistance, fatigue strength and other effects of the center tube, which affects the service life of the formed center tube and cannot meet the use requirements.

[0004] In summary, developing a method for forming a special center tube for a four-link is a key issue that needs to be urgently addressed in the field of bicycle technology. Summary of the Invention

[0005] In response to the above-mentioned shortcomings of the prior art, the present invention provides a method for forming a special center tube for a four-link linkage. The provided method is easy to operate, greatly improves the rigidity, hardness, wear resistance, fatigue strength and toughness of the center tube, extends the service life and performance of the center tube, and improves the quality of the formed center tube.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a method for forming a special middle tube for a four-link rod, comprising the following steps:

[0008] (1) Take the raw material of the middle tube, place the raw material of the middle tube in a melting furnace and melt it to obtain a casting liquid for use;

[0009] (2) taking an ingot mold, pouring the obtained casting liquid into the ingot mold, and cooling to obtain an ingot;

[0010] (3) repeatedly hammering the ingot into a plate strip, then placing it in a bending device to bend it to obtain a bent strip, and pouring the casting liquid at the connection of the bent strip. After cooling, a tube body is obtained;

[0011] (4) Place the core rod in the tube body, then place it in the lower mold, and punch it with the upper mold to make the primary middle tube;

[0012] (5) Remove the primary middle tube, apply quenching agent on its surface, and wrap it with tin foil. Quench it in a quenching furnace, then remove the tin foil and cool it in water. Repeat the quenching and water cooling 3-4 times to complete the forming of the middle tube.

[0013] The present invention is further configured as follows: in step (1), when the middle tube raw material is placed in a smelting furnace for melting, a protective gas needs to be introduced into the smelting furnace.

[0014] The present invention is further configured such that: the protective gas is either helium or argon.

[0015] The present invention is further configured as follows: in step (2), before pouring the obtained casting liquid into the ingot mold, a release agent needs to be sprayed on the inner wall of the ingot mold, and the release agent is coated sand.

[0016] The present invention is further configured as follows: in step (3), when the plate strip is placed in the bending device for bending, the plate strip is first heated until it softens.

[0017] The present invention is further configured as follows: in step (4), during the process of the upper die punching the curved strip, the curved strip in the lower die is rotated once every 3-4 punchings.

[0018] The present invention is further configured as follows: in step (5), the quenching agent is made of the following raw materials in parts by weight:

[0019] 6-8 parts of sodium 2-acrylate homopolymer, 2-4 parts of ammonium acetate, 1-3 parts of sodium benzoate, 3-7 parts of triisopropyl phosphite, 2-4 parts of polyethylene wax, 1-3 parts of lauryl acetate, and 20-40 parts of deionized water;

[0020] The preparation process of the quenching agent is as follows:

[0021] Weigh deionized water and place it in a blender. Add 2-sodium acrylate homopolymer, ammonium acetate, triisopropyl phosphite, and polyethylene wax into the blender. Mix at 40-50°C and a speed of 300-310 r / min for 22-24 minutes.

[0022] Sodium benzoate and lauryl acetate were added to a stirrer, and the temperature was raised to 80° C. while stirring, and mixed at 820-840 r / min for 10-12 minutes to prepare a quenching agent;

[0023] The temperature is increased at a rate of 15-20°C / min.

[0024] The present invention is further configured as follows: in step (5), the temperature of the quenching treatment is 610-720° C., and the time is 20-30 minutes.

[0025] The present invention is further configured as follows: in step (5), the water cooling time is 10-12 minutes.

[0026] The present invention is further configured as follows: in step (5), after the quenching treatment and water cooling are all completed, the formed middle tube is taken out and the formed middle tube is polished smooth with 80-100 mesh sandpaper.

[0027] Beneficial effects

[0028] Compared with the known public technology, the technical solution provided by the present invention has the following advantages:

[0029] Beneficial effects:

[0030] The method provided by the present invention comprises the following steps: melting the raw material of the middle tube in a smelting furnace under a protective gas state to obtain a casting liquid, then casting the ingot through an ingot mold to obtain an ingot, repeatedly hammering the ingot into an ingot, then bending the ingot, and pouring the casting liquid at the connection of the bent band to obtain a tube body, and punching the tube body through upper and lower molds to obtain a primary middle tube, and finally applying a quenching agent on the surface of the tube, wrapping the tube with tin foil, quenching the tube in a quenching furnace, removing the tin foil, and cooling the tube in water, repeating the quenching and water cooling to complete the forming of the middle tube. The provided method is simple to operate, greatly improves the rigidity, hardness, wear resistance, fatigue strength and toughness of the middle tube, extends the service life and performance of the middle tube, and improves the quality of the formed middle tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention is a flow chart of a method for forming a special middle tube for a four-linkage. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0033] The present invention will be further described below with reference to the embodiments.

[0034] Example 1:

[0035] like Figure 1 As shown, the present invention provides a method for forming a special middle tube for a four-link rod, comprising the following steps:

[0036] (1) Take the middle tube material, place the middle tube material in a melting furnace to melt, and obtain the casting liquid for use.

[0037] Furthermore, when the raw material of the middle tube is placed in a melting furnace for melting, a protective gas needs to be introduced into the melting furnace.

[0038] Furthermore, the protective gas is helium.

[0039] In this embodiment, it should be noted that the raw material of the middle tube is placed in a smelting furnace for melting to obtain a casting liquid for casting, and a protective gas is used to improve the purity of the casting liquid to prevent the casting liquid from reacting with other gases in the air during the melting process, thereby preventing the quality of the subsequently formed middle tube from being affected.

[0040] (2) Taking an ingot mold, pouring the obtained casting liquid into the ingot mold, and cooling to obtain an ingot.

[0041] Furthermore, before pouring the obtained casting liquid into the ingot mold, it is necessary to spray a release agent on the inner wall of the ingot mold, and the release agent is coated sand.

[0042] In this embodiment, the provided coated sand can facilitate the separation of the cooled ingot from the ingot mold.

[0043] (3) The ingot is repeatedly hammered into a plate strip, and then placed in a bending device for bending to obtain a bent strip, and pouring liquid at the connection of the bent strip. After cooling, a tube body is obtained.

[0044] Furthermore, when the plate strip is placed in the bending device for bending, it is first heated until it softens.

[0045] In this embodiment, the ingot is first repeatedly hammered into a plate strip, then bent, and the gap at the bent connection is sealed to obtain a tube body, thereby avoiding the situation where the gap at the bent connection is not tightly closed when the upper and lower molds are subsequently stamped. In addition, the plate strip is heated until it softens, which facilitates the bending of the plate strip.

[0046] (4) A core rod is placed in the tube body, which is then placed in the lower mold and punched with the upper mold to produce a primary middle tube.

[0047] Furthermore, during the process of punching the curved strip by the upper die, the curved strip in the lower die is rotated once every four punchings.

[0048] In this embodiment, the core of the middle tube is retained by the core rod, and its outer diameter is equal to the inner diameter of the formed middle tube. The hammering combined with stamping method is adopted to improve the hardness and other properties of the formed middle tube.

[0049] (5) Remove the primary middle tube, apply quenching agent on its surface, and wrap it with tin foil. Quench it in a quenching furnace, then remove the tin foil and cool it in water. Repeat the quenching and water cooling 4 times to complete the forming of the middle tube.

[0050] Furthermore, the quenching agent is made from the following raw materials in parts by weight:

[0051] 8 parts of sodium 2-acrylate homopolymer, 4 parts of ammonium acetate, 3 parts of sodium benzoate, 7 parts of triisopropyl phosphite, 4 parts of polyethylene wax, 3 parts of lauryl acetate, and 40 parts of deionized water;

[0052] The preparation process of quenching agent is as follows:

[0053] Deionized water was weighed and placed in a blender. 2-Sodium acrylate homopolymer, ammonium acetate, triisopropyl phosphite, and polyethylene wax were added to the blender. The mixture was mixed at 50°C and a rotation speed of 310 r / min for 24 minutes.

[0054] Sodium benzoate and lauryl acetate were added to a stirrer, and the temperature was raised to 80° C. while stirring, and the mixture was mixed at 840 r / min for 12 minutes to prepare a quenching agent.

[0055] The temperature was increased at a rate of 20°C / min.

[0056] Furthermore, the quenching treatment temperature is 720° C. and the time is 30 min.

[0057] Furthermore, the water cooling time is 12 minutes.

[0058] Furthermore, after the quenching treatment and water cooling are all completed, the formed middle tube is taken out and polished smooth with 00-mesh sandpaper.

[0059] In this embodiment, it should be noted that the present invention provides a quenching agent and a method for preparing the same. The prepared quenching agent is applied to the surface of the primary middle tube and wrapped with tin foil, and then repeatedly quenched and water-cooled. The quenching treatment can greatly improve the rigidity, hardness, wear resistance, fatigue strength and toughness of the middle tube. Furthermore, the quenching agent can be used to enhance the service life and performance of the middle tube and avoid oxidation during quenching of the middle tube.

[0060] Example 2:

[0061] like Figure 1 As shown, the present invention provides a method for forming a special middle tube for a four-link rod, comprising the following steps:

[0062] (1) Take the middle tube material, place the middle tube material in a melting furnace to melt, and obtain the casting liquid for use.

[0063] Furthermore, when the raw material of the middle tube is placed in a melting furnace for melting, a protective gas needs to be introduced into the melting furnace.

[0064] Furthermore, the protective gas is helium.

[0065] In this embodiment, it should be noted that the raw material of the middle tube is placed in a smelting furnace for melting to obtain a casting liquid for casting, and a protective gas is used to improve the purity of the casting liquid to prevent the casting liquid from reacting with other gases in the air during the melting process, thereby preventing the quality of the subsequently formed middle tube from being affected.

[0066] (2) Taking an ingot mold, pouring the obtained casting liquid into the ingot mold, and cooling to obtain an ingot.

[0067] Furthermore, before pouring the obtained casting liquid into the ingot mold, it is necessary to spray a release agent on the inner wall of the ingot mold, and the release agent is coated sand.

[0068] In this embodiment, the provided coated sand can facilitate the separation of the cooled ingot from the ingot mold.

[0069] (3) The ingot is repeatedly hammered into a plate strip, and then placed in a bending device for bending to obtain a bent strip, and pouring liquid at the connection of the bent strip. After cooling, a tube body is obtained.

[0070] Furthermore, when the plate strip is placed in the bending device for bending, it is first heated until it softens.

[0071] In this embodiment, the ingot is first repeatedly hammered into a plate strip, then bent, and the gap at the bent connection is sealed to obtain a tube body, thereby avoiding the situation where the gap at the bent connection is not tightly closed when the upper and lower molds are subsequently stamped. In addition, the plate strip is heated until it softens, which facilitates the bending of the plate strip.

[0072] (4) A core rod is placed in the tube body, which is then placed in the lower mold and punched with the upper mold to produce a primary middle tube.

[0073] Furthermore, during the process of punching the curved strip by the upper die, the curved strip in the lower die is rotated once every three punchings.

[0074] In this embodiment, the core of the middle tube is retained by the core rod, and its outer diameter is equal to the inner diameter of the formed middle tube. The hammering combined with stamping method is adopted to improve the hardness and other properties of the formed middle tube.

[0075] (5) Remove the primary middle tube, apply quenching agent on its surface, and wrap it with tin foil. Quench it in a quenching furnace, then remove the tin foil and cool it in water. Repeat the quenching and water cooling three times to complete the forming of the middle tube.

[0076] Furthermore, the quenching agent is made from the following raw materials in parts by weight:

[0077] 6 parts of sodium 2-acrylate homopolymer, 2 parts of ammonium acetate, 1 part of sodium benzoate, 3 parts of triisopropyl phosphite, 2 parts of polyethylene wax, 1 part of lauryl acetate, and 20 parts of deionized water;

[0078] The preparation process of quenching agent is as follows:

[0079] Deionized water was weighed and placed in a blender. Sodium 2-acrylate homopolymer, ammonium acetate, triisopropyl phosphite, and polyethylene wax were added to the blender. The mixture was mixed at 40°C and a speed of 300 r / min for 22 minutes.

[0080] Sodium benzoate and lauryl acetate were added to a stirrer, and the temperature was raised to 80° C. while stirring, and mixed at 820 r / min for 10 minutes to prepare a quenching agent;

[0081] The temperature was increased at a rate of 15°C / min.

[0082] Furthermore, the quenching treatment temperature is 610 °C and the time is 20 min.

[0083] Furthermore, the water cooling time is 10 min.

[0084] Furthermore, after the quenching treatment and water cooling are all completed, the formed middle tube is taken out and polished smooth with 80-mesh sandpaper.

[0085] In this embodiment, it should be noted that the present invention provides a quenching agent and a method for preparing the same. The prepared quenching agent is applied to the surface of the primary middle tube and wrapped with tin foil, and then repeatedly quenched and water-cooled. The quenching treatment can greatly improve the rigidity, hardness, wear resistance, fatigue strength and toughness of the middle tube. Furthermore, the quenching agent can be used to enhance the service life and performance of the middle tube and avoid oxidation during quenching of the middle tube.

[0086] Example 3:

[0087] like Figure 1 As shown, the present invention provides a method for forming a special middle tube for a four-link rod, comprising the following steps:

[0088] (1) Take the middle tube material, place the middle tube material in a melting furnace to melt, and obtain the casting liquid for use.

[0089] Furthermore, when the raw material of the middle tube is placed in a melting furnace for melting, a protective gas needs to be introduced into the melting furnace.

[0090] Furthermore, the protective gas is argon.

[0091] In this embodiment, it should be noted that the raw material of the middle tube is placed in a smelting furnace for melting to obtain a casting liquid for casting, and a protective gas is used to improve the purity of the casting liquid to prevent the casting liquid from reacting with other gases in the air during the melting process, thereby preventing the quality of the subsequently formed middle tube from being affected.

[0092] (2) Taking an ingot mold, pouring the obtained casting liquid into the ingot mold, and cooling to obtain an ingot.

[0093] Furthermore, before pouring the obtained casting liquid into the ingot mold, it is necessary to spray a release agent on the inner wall of the ingot mold, and the release agent is coated sand.

[0094] In this embodiment, the provided coated sand can facilitate the separation of the cooled ingot from the ingot mold.

[0095] (3) The ingot is repeatedly hammered into a plate strip, and then placed in a bending device for bending to obtain a bent strip, and pouring liquid at the connection of the bent strip. After cooling, a tube body is obtained.

[0096] Furthermore, when the plate strip is placed in the bending device for bending, it is first heated until it softens.

[0097] In this embodiment, the ingot is first repeatedly hammered into a plate strip, then bent, and the gap at the bent connection is sealed to obtain a tube body, thereby avoiding the situation where the gap at the bent connection is not tightly closed when the upper and lower molds are subsequently stamped. In addition, the plate strip is heated until it softens, which facilitates the bending of the plate strip.

[0098] (4) A core rod is placed in the tube body, which is then placed in the lower mold and punched with the upper mold to produce a primary middle tube.

[0099] Furthermore, during the process of punching the curved strip by the upper die, the curved strip in the lower die is rotated once every four punchings.

[0100] In this embodiment, the core of the middle tube is retained by the core rod, and its outer diameter is equal to the inner diameter of the formed middle tube. The hammering combined with stamping method is adopted to improve the hardness and other properties of the formed middle tube.

[0101] (5) Remove the primary middle tube, apply quenching agent on its surface, and wrap it with tin foil. Quench it in a quenching furnace, then remove the tin foil and cool it in water. Repeat the quenching and water cooling 4 times to complete the forming of the middle tube.

[0102] Furthermore, the quenching agent is made from the following raw materials in parts by weight:

[0103] 7 parts of sodium 2-acrylate homopolymer, 3 parts of ammonium acetate, 2 parts of sodium benzoate, 5 parts of triisopropyl phosphite, 3 parts of polyethylene wax, 2 parts of lauryl acetate, and 30 parts of deionized water;

[0104] The preparation process of quenching agent is as follows:

[0105] Deionized water was weighed and placed in a blender. 2-Sodium acrylate homopolymer, ammonium acetate, triisopropyl phosphite, and polyethylene wax were added to the blender. The mixture was mixed at 45°C and a rotation speed of 305 r / min for 23 minutes.

[0106] Sodium benzoate and lauryl acetate were added to a stirrer, and the temperature was raised to 80° C. while stirring, and the mixture was mixed at 830 r / min for 11 minutes to prepare a quenching agent.

[0107] The temperature was increased at a rate of 17°C / min.

[0108] Furthermore, the quenching treatment temperature is 680° C. and the time is 25 min.

[0109] Furthermore, the water cooling time is 11 min.

[0110] Furthermore, after the quenching treatment and water cooling are all completed, the formed middle tube is taken out and polished smooth with 90-mesh sandpaper.

[0111] In this embodiment, it should be noted that the present invention provides a quenching agent and a method for preparing the same. The prepared quenching agent is applied to the surface of the primary middle tube and wrapped with tin foil, and then repeatedly quenched and water-cooled. The quenching treatment can greatly improve the rigidity, hardness, wear resistance, fatigue strength and toughness of the middle tube. Furthermore, the quenching agent can be used to enhance the service life and performance of the middle tube and avoid oxidation during quenching of the middle tube.

[0112] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for forming a special middle tube for a four-link, characterized in that: The following steps are involved: (1) Take the raw materials of the middle tube, place the raw materials of the middle tube in a melting furnace and melt them to obtain the casting liquid for use; (2) taking an ingot mold, pouring the obtained casting liquid into the ingot mold, and cooling to obtain an ingot; (3) The ingot is repeatedly hammered into a plate strip, and then placed in a bending device for bending to obtain a bent strip, and pouring liquid at the connection of the bent strip. After cooling, a tube body is obtained; (4) Place the core rod in the tube body, then place it in the lower mold, and punch it with the upper mold to make the primary middle tube; (5) Remove the primary middle tube, apply quenching agent on its surface, wrap it with tin foil, quench it in a quenching furnace, remove the tin foil and cool it in water, repeat the quenching and water cooling 3-4 times to complete the forming of the middle tube; The quenching agent is made from the following raw materials in parts by weight: 6-8 parts of sodium 2-acrylate homopolymer, 2-4 parts of ammonium acetate, 1-3 parts of sodium benzoate, 3-7 parts of triisopropyl phosphite, 2-4 parts of polyethylene wax, 1-3 parts of lauryl acetate, and 20-40 parts of deionized water; The preparation process of the quenching agent is as follows: Weigh deionized water and place it in a blender. Add 2-sodium acrylate homopolymer, ammonium acetate, triisopropyl phosphite, and polyethylene wax into the blender. Mix at 40-50°C and a speed of 300-310 r / min for 22-24 minutes. Sodium benzoate and lauryl acetate were added to a stirrer, and the temperature was raised to 80° C. while stirring, and mixed at 820-840 r / min for 10-12 minutes to prepare a quenching agent; The temperature is increased at a rate of 15-20°C / min.

2. A method for forming a special middle tube for a four-link according to claim 1, characterized in that: In step (1), when the raw material of the middle tube is placed in a melting furnace for melting, a protective gas needs to be introduced into the melting furnace.

3. A method for forming a special middle tube for a four-link according to claim 2, characterized in that: The protective gas is either helium or argon.

4. The method for forming a special middle tube for a four-link according to claim 1, characterized in that: In step (2), before pouring the obtained casting liquid into the ingot mold, it is also necessary to spray a release agent on the inner wall of the ingot mold, and the release agent is coated sand.

5. The method for forming a special middle tube for a four-link according to claim 1, characterized in that: In step (3), when the plate strip is placed in the bending device for bending, the plate strip is first heated until it softens.

6. The method for forming a special middle tube for a four-link rod according to claim 1, characterized in that: In step (4), during the process of punching the curved strip by the upper die, the curved strip in the lower die is rotated once every 3-4 punchings.

7. The method for forming a special middle tube for a four-link rod according to claim 1, characterized in that: In step (5), the quenching treatment temperature is 610-720°C and the time is 20-30 minutes.

8. The method for forming a special middle tube for a four-link rod according to claim 1, characterized in that: In step (5), the water cooling time is 10-12 minutes.

9. The method for forming a special middle tube for a four-link rod according to claim 1, characterized in that: In step (5), after the quenching treatment and water cooling are all completed, the formed middle tube is taken out and polished smooth with 80-100 mesh sandpaper.

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