A processing method for ball sliding tube

Abstract

The present invention discloses a method for processing a ball sliding tube. The method adopts a special-shaped thin-wall extrusion process. By processing the processed thin-walled part, the outer surface and inner hole of the thin-walled part remain unchanged, and only the metal material at the position of the arc groove undergoes plastic deformation. The specific steps include: 1) manufacturing the thin-walled part; 2) thin-wall extrusion; 3) high-frequency processing; and 4) finished product testing. Through the above-mentioned method, the present invention provides a method for processing a ball sliding tube. The method adopts a special-shaped thin-wall extrusion process to overcome the problems of cracking, breaking, irregular shape after extrusion, and sudden deformation after stress release in the thin-wall deformation of the part. The method ensures that the high requirements for all dimensions, form and position tolerances of the inner hole and the arc groove are met, thereby achieving the purpose of improving accuracy and efficiency. The outer surface and inner hole remain unchanged, and only the metal material at the position of the small arc groove that is divided into 120 degrees equally as required by the drawing undergoes plastic deformation.

Description

Technical Field

[0001] The invention relates to the field of automobile parts, in particular to a processing method of a ball sliding tube. Background Art

[0002] The ball sliding tube is used in conjunction with the ball sliding shaft to form a steering column used in the automobile steering system. An arc groove is set on the inner wall of the ball sliding tube at every 120° circumferential interval. The corners of the three arc grooves are all arc-shaped. The sliding track of the inner arc groove is precisely adapted to the sliding of the steel ball retainer roller.

[0003] During the processing of ball sliding tube, the inner wall is formed into a thin-walled part. There are problems such as cracks, breakage, irregular shape after extrusion and sudden deformation after stress release in the thin-wall deformation. Summary of the Invention

[0004] The main technical problem solved by the present invention is to provide a processing method for a ball sliding tube, which can overcome the problems of cracks, breakage, irregular shapes after extrusion and sudden deformation after stress release in thin-wall deformation of parts.

[0005] To solve the above technical problems, the present invention adopts a technical solution: providing a method for processing a ball sliding tube, using a special-shaped thin-wall extrusion process, processing the processed thin-walled part so that the outer surface and inner hole of the thin-walled part remain unchanged, and only the metal material at the position of the arc groove is plasticized. The specific steps include:

[0006] 1) Manufacturing of thin-walled parts: Select tubes of appropriate thickness and roughness, fully anneal them, analyze their composition using an infrared spectrometer, and cut them to the dimensions required by the drawing using an automatic saw to obtain the thin-walled parts required for processing;

[0007] 2) Thin-wall extrusion: performing a special-shaped thin-wall extrusion process on the thin-walled part obtained in step 1) to control the straightness, torsion and diameter of the arc groove after extrusion;

[0008] 3) High-frequency treatment: performing high-frequency quenching and shaping on the thin-walled part extruded in step 2);

[0009] 4) Finished product inspection: The thin-walled part after the treatment in step 3) is engraved, cleaned, and inspected for cracks to obtain a finished product.

[0010] In a preferred embodiment of the present invention, in step 1), the cut pipe is subjected to rough processing and a first phosphine saponification treatment.

[0011] In a preferred embodiment of the present invention, the rough machining includes rough turning of two planes, rough turning of the outer circle, rough centerless grinding of the outer circle and rough drilling and boring.

[0012] In a preferred embodiment of the present invention, the thin-walled part is subjected to a first finishing process before the high-frequency treatment in step 3).

[0013] In a preferred embodiment of the present invention, the first finishing includes finishing turning of both end faces, first finishing boring and finishing turning of the outer circle.

[0014] In a preferred embodiment of the present invention, a second finishing process is performed after the high-frequency processing in step 3).

[0015] In a preferred embodiment of the present invention, the second finishing process includes finishing boring the outer circular groove, second finishing boring and polishing.

[0016] In a preferred embodiment of the present invention, a second phosphating saponification treatment is required between the high-frequency quenching and the shaping in step 3).

[0017] The beneficial effects of the present invention are as follows: a processing method of a ball sliding tube of the present invention adopts a special-shaped thin-wall extrusion process to overcome the problems of cracks, breakage, irregular shapes after extrusion and sudden deformation after stress release of parts in thin-wall deformation, and ensure the high requirements of all dimensions and form and position tolerances of the inner hole and arc groove, thereby achieving the purpose of improving precision and efficiency, so that the outer surface and the inner hole do not change, and only the metal material at the position of the small arc groove that is equally divided by 120° as required by the drawing undergoes plastic deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional diagram of the finished product after processing by a processing method of a ball sliding tube according to the present invention;

[0019] Figure 2 The present invention is a process flow chart of a method for processing a ball sliding tube. DETAILED DESCRIPTION

[0020] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0021] See also Figure 1 and Figure 2 , embodiments of the present invention include:

[0022] A method for processing a ball sliding tube adopts a special-shaped thin-wall extrusion process. By processing the processed thin-walled parts, the outer surface and inner hole of the thin-walled parts remain unchanged. Only the metal material at the position of the arc groove is plasticized. The method overcomes the problems of cracks, breakage, irregular shapes after extrusion and sudden deformation after stress release in the thin-wall deformation of the parts, ensures the high requirements of all dimensions, form and position tolerances of the inner hole and the arc groove, thereby achieving the purpose of improving precision and efficiency, reducing the cost of similar products by 30% to 50%, and at the same time increasing their service life, making them more durable and environmentally friendly.

[0023] The specific steps include:

[0024] 1) Manufacturing of thin-walled parts: Select pipes of appropriate thickness and roughness, fully anneal the selected pipes, analyze the composition of the entire pipe using an infrared spectrometer, and cut them into the dimensions required by the drawing using an automatic saw to obtain the thin-walled parts required for processing.

[0025] Select the pipe with appropriate thickness and roughness, first heat the pipe to 780° and then keep it warm for 4 to 6 hours, then cool it out of the furnace, analyze the composition of the entire pipe with an infrared spectrometer, and then combine several pipes into the jaws of a CNC sawing machine, clamp them after laying the plane flat, weld the root of the pipe firmly, calibrate the raw material to be perpendicular to the saw blade, and start processing. First, saw off the part of the head that is smaller than the drawing requirement after cold drawing (due to the existence of different lengths, at least 180mm of the head is sawed off), and then process it according to the drawing size requirements (if it is found that the end face of the blanking part is not vertical, it should be adjusted in time), and finally stop processing at 60mm-80mm away from the welding point, put the welding part and the head part into the isolation area, and the blanking length is 121+1mm.

[0026] The complete annealing is to unify the structure, soften the structure, refine the particles, improve the processing performance, and ensure the hardness accuracy of the cold extruded ball groove: <HV 190。

[0027] The cut pipe is subjected to rough processing and a first phosphorus saponification treatment, wherein the rough processing includes rough turning of two planes, rough turning of the outer circle, rough centerless grinding of the outer circle and rough drilling and boring.

[0028] 2) Thin-wall extrusion: The thin-walled part obtained in step 1) is subjected to a special-shaped thin-wall extrusion process, and the straightness, torsion and diameter of the arc groove after extrusion are controlled so that the straightness, torsion and diameter of the arc groove are 0.02 μm / 80 mm, 0.03° / 80 mm and φ21.4 mm, respectively, and the thinnest part of the thin-walled part is only 2 mm.

[0029] Install the upper and lower molds on the hydraulic press, adjust the size of the ejector rod, adjust the height limit, adjust the pressure of the hydraulic press to 12-20Mpa, insert the small end of the part into the mold barrel, press the start button, squeeze the hydraulic press to the limit, and then press the start button to eject it, ensuring that the arc groove roughness (axial): Ra1.2 maximum, the arc groove roughness (radial): Ra5.0 maximum.

[0030] The thin-walled part is subjected to a first finishing process before the high-frequency treatment, and the first finishing process includes finishing turning of both end faces, first finishing boring and finishing turning of the outer circle.

[0031] 3) High frequency treatment: The thin-walled part extruded in step 2) is subjected to high frequency quenching and shaping, and only the arc groove position is subjected to high frequency quenching to ensure hardness HRC: 50-55, quenching depth: 0.6-1.0mm, and the outer circle structure is not allowed to change, and the hardness <HRC35。

[0032] A second phosphorus saponification treatment is required between the high-frequency quenching and the shaping.

[0033] After the high-frequency treatment, a second finishing process is performed, which includes finishing boring the outer circular groove, second finishing boring and polishing. The polishing is used to remove the oxide scale on the surface of the thin-walled part after cutting.

[0034] 4) Finished product inspection: The thin-walled parts after step 3) are engraved, cleaned, and inspected for cracks to obtain a finished product. The engraved thin-walled parts are cleaned using an ultrasonic cleaning machine, and then inspected for cracks using a flaw detector.

[0035] The rough turning of the two planes, the rough turning of the outer circle, the rough drilling and boring, the fine turning of the two end faces, the first fine boring and the fine turning of the outer circle, the fine turning of the outer circular groove of the bored hole and the second fine boring are all processed by CNC lathes, and the steps are the same. The difference lies in the processed surfaces and the tools used. The processing steps are to install a core rod in the inner hole of the spindle of the CNC lathe, limit the calibration of the three-jaw runout <0.03, put the pipe into the chuck and push the pipe tightly with the right hand until it is against the limit reference, then step on the switch of the CNC lathe to clamp it, close the door of the CNC lathe and press the start button, and process it to the required size in the drawing.

[0036] Different from the prior art, the present invention provides a processing method for a ball sliding tube. The method adopts a special-shaped thin-wall extrusion process to overcome the problems of cracks, breakage, irregular shapes after extrusion and sudden deformation after stress release in thin-wall deformation of parts, ensure the high requirements of all dimensions and form and position tolerances of the inner hole and arc groove, thereby achieving the purpose of improving precision and efficiency, so that the outer surface and the inner hole do not change, only the metal material at the position of the small arc groove that is equally divided by 120° as required by the drawing undergoes plastic deformation, reducing the cost of similar products by 30% to 50%, and at the same time increasing its service life, making it more durable and environmentally friendly. Under the special-shaped thin-wall extrusion process, the surface quality of the workpiece can be significantly improved, a large amount of material can be saved, and production efficiency can be improved, thereby achieving the purpose of reducing product costs.

[0037] In the description of the present invention, it should be noted that the components are all universal standard parts or components known to those skilled in the art, and their structures and principles are known to those skilled in the art through technical manuals or conventional test methods. The directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "inside", "outside", etc. are based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention.

[0038] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for processing a ball sliding tube, characterized in that: The special-shaped thin-wall extrusion process is used to process the processed thin-walled parts so that the outer surface and inner hole of the thin-walled parts do not change, and only the metal material at the arc groove position is plasticized. The specific steps include: 1) Manufacturing of Thin-Walled Parts: Select a tube of appropriate thickness and roughness, fully anneal the selected tube, analyze the composition of the entire tube using an infrared spectrometer, cut it to the dimensions required by the drawing using an automatic saw, and then perform rough machining and a first phosphorus saponification treatment on the cut tube. The rough machining includes rough turning of two planes, rough turning of the outer diameter, rough centerless grinding of the outer diameter, and rough drilling and boring. 2) Thin-wall extrusion: performing a special-shaped thin-wall extrusion process on the thin-walled part obtained in step 1) to control the straightness, torsion and diameter of the arc groove after extrusion; 3) High-frequency treatment: performing high-frequency quenching and shaping on the thin-walled part extruded in step 2), wherein a second phosphorus saponification treatment is required between the high-frequency quenching and the shaping, and performing a first finishing process on the thin-walled part before the high-frequency treatment and a second finishing process after the high-frequency treatment; 4) Finished product inspection: The thin-walled part after the treatment in step 3) is engraved, cleaned, and inspected for cracks to obtain a finished product.

2. The method for processing a ball sliding tube according to claim 1, characterized in that: The first finishing process includes finishing turning of both end faces, first finishing boring and finishing turning of the outer circle.

3. The method for processing a ball sliding tube according to claim 1, characterized in that: The second finishing process includes finishing boring the outer circular groove, second finishing boring and polishing.

Images