Machining method for thin-wall barrel-shaped part made of permalloy

Abstract

The invention belongs to the technical field of machining, and particularly relates to a machining method for a thin-wall barrel-shaped part made of permalloy. The machining method comprises the following steps that a bar is blanked; putting the bar into a machine tool, randomly selecting one end as a chuck for clamping, and turning an inner circle after the end surface of the other end is flattened; turning an outer circle to form an outer circle positioning surface, and cutting off the chuck; the inner circle and the outer circle of the part are positioned through a mandrel and a back cap respectively, and then the end face is machined; and removing the back cap, and performing finish turning on the outer circle. According to the machining method, the problem that the form and location tolerance is affected by radial deformation generated in the machining process of the permalloy thin-wall barrel-shaped part is solved, the percent of pass is increased, and meanwhile the machining efficiency is high.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing, and in particular relates to a processing method for a thin-walled barrel-shaped part made of a Permalloy material. Background Art

[0002] Thin-walled barrel parts are important parts in fiber optic gyroscope products. They are made of Permalloy. The shape and position tolerances of this part are high. The barrel wall is thin, with the thinnest part being only 0.5mm and the thickest part being 1mm. The barrel wall has high dimensional accuracy and the verticality requirement is only 5 wires. The main processing difficulties are: (1) Permalloy material has high plasticity and high hardness, low processing efficiency, and is not easy to break or entangle chips, which can easily damage the tool; (2) It is small in size and difficult to clamp; (3) The barrel wall is 1mm and the verticality is 0.05mm, which is very easy to deform during processing.

[0003] The traditional processing method is to adopt a process concentration method, in which one process and one workstation are processed at one time. First, the inner circle is processed to the size requirements of the drawing, then the outer circle is processed, and finally the section is cut. However, since the wall of the part is too thin, the outer circle is deformed due to the radial force when processing the outer circle, especially the mouth position will be pressed inward, and finally the verticality of the cylinder wall is out of tolerance, and the qualified rate is extremely low. Summary of the invention

[0004] The purpose of the present invention is to provide a method for processing thin-walled barrel-shaped parts made of Permalloy, which solves the problem of radial deformation affecting shape and position tolerances during the processing of Permalloy thin-walled barrel-shaped parts, improves the qualified rate, and has high processing efficiency.

[0005] Specifically, the present invention provides the following technical solutions:

[0006] A method for processing a thin-walled barrel-shaped part made of Permalloy, comprising the following steps:

[0007] (1) Cutting of rods made of Permalloy;

[0008] (2) Place the bar into the machine tool, and leave a certain length at either end of the bar as a chuck for clamping. Use a turning tool to flatten the end face of the other end and then turn the inner circle to the inner circle depth and inner diameter required by the design of the thin-walled barrel-shaped part;

[0009] (3) Keep the above clamping, turn the outer circle, form the outer circle positioning surface, and cut off the chuck;

[0010] (4) using a mandrel and a back cap to respectively position the inner circle and outer circle of the part obtained in step (3), and then lathe the end face of the end that has not been lathed to the length dimension required by the design of the thin-walled barrel-shaped part;

[0011] The mandrel comprises a main shaft, the main shaft is contacted and positioned with the inner circle of the part, the lower end of the main shaft has an integrally cast stepped shaft, the outer peripheral surface of the stepped shaft is provided with an external thread, and the lower end of the stepped shaft has an integrally cast chuck, the chuck is used to clamp the mandrel to the turning and milling composite equipment;

[0012] The back cap is in an inverted cylindrical shape, and an internal thread matching the external thread on the core shaft is provided on the inner circumference of the back cap. A circular through hole is provided at the center of the top of the back cap, and the inner wall of the circular through hole contacts and positions the outer circle of the part;

[0013] (5) The back cap is removed, the part is axially pressed against the mandrel, and the outer diameter is precision-turned to the outer diameter size required by the design of the thin-walled barrel-shaped part.

[0014] Preferably, in step (2), the inner circle turning includes rough inner circle turning and fine inner circle turning in sequence;

[0015] The lathe speed of the rough turning inner circle is 200 rpm to 230 rpm, and the rough turning leaves 1mm for the fine turning;

[0016] The lathe speed for fine turning the inner circle is 180 rpm to 200 rpm.

[0017] Preferably, in step (3), the outer circle turning includes rough outer circle turning and semi-finishing outer circle turning in sequence;

[0018] The lathe speed for rough turning the outer circle is 270 rpm to 320 rpm, and the rough turning allows 1 mm for semi-finishing turning;

[0019] The lathe speed for semi-finishing outer circle is 230 rpm to 260 rpm, and the allowance for semi-finishing turning to finishing turning is 1 mm.

[0020] Preferably, in step (3), the chuck is cut off after leaving a 1.5 mm length dimension required by the design.

[0021] Preferably, in step (4), the inner wall height of the circular through hole on the back cap is 5 mm to 10 mm.

[0022] Preferably, in step (5), the lathe speed for finishing the outer circle is 200 to 220 revolutions per minute.

[0023] Preferably, the turning tool of the machine tool is made of YW type cemented carbide.

[0024] Beneficial effects achieved by the present invention:

[0025] (1) The present invention provides a method for processing a thin-walled barrel-shaped part made of a Permalloy material. When processing the upper end face size of the part, the back cap mandrel is used in combination for positioning, which can clamp the part and stabilize the part during high-speed rotation to ensure the size requirements of the end face reference surface. If the back cap is not used to tighten the outer circle of the part, the workpiece will shake greatly during the high-speed rotation processing of the part, and the vibration of the turning tool will cause the shape and position tolerance of the end face reference surface to exceed the tolerance, which directly affects the size of other parts.

[0026] (2) The present invention provides a method for processing a thin-walled barrel-shaped part made of Permalloy. When finishing the outer circle, the mandrel is kept in contact with the inner circle of the part, and the inner surface friction is relied on to add a top to maintain axial compression to prevent the part from radially deforming beyond the geometric tolerance requirements;

[0027] (3) The present invention provides a method for processing a thin-walled barrel-shaped part made of Permalloy, which uses a tool made of YW-type cemented carbide with a small cutting depth, high rotation speed, and fast feed, thereby solving the problem of chip breaking and chip entanglement during Permalloy processing, which may cause tool damage;

[0028] (4) The present invention provides a method for processing thin-walled barrel-shaped parts made of Permalloy, which improves the qualification rate and processing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of a thin-walled barrel-shaped part made of Permalloy prepared in Example 1.

[0030] Figure 2 Schematic diagram of the structure of the mandrel used in Example 1.

[0031] Figure 3 Schematic diagram of the structure of the back cap used in Example 1.

[0032] Figure 4 This is a schematic diagram of the structure of the core shaft and back cap for positioning parts in Example 1.

[0033] Figure 5 This is a schematic diagram of the structure of the ejector pin axially pressing the core shaft in Example 1.

[0034] Among them, 1 is a part, 2 is a back cap, 3 is a core shaft, 2-1 is the inner wall of the circular through hole, 2-2 is the internal thread, 3-1 is the main shaft, 3-2 is the step shaft, 3-3 is the chuck, and 4 is the ejector pin. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention. If no specific technology or conditions are specified in the embodiments, the technology or conditions described in the literature in the field or the product manual shall be followed.

[0036] Example 1

[0037] Example 1 provides a method for processing a thin-walled barrel-shaped part made of a Permalloy material, which can be partially referred to Figure 1-Figure 5 , the specific steps are as follows:

[0038] (1) Cutting material: Φ52mm bar, 48mm long.

[0039] (2) Rough turning of inner circle: Use turning and milling compound equipment, the tool material is YW type carbide, one end of the bar is clamped with a chuck, the chuck length is 25mm, and the other end surface is turned flat. Set the lathe speed to 220 rpm, and rough-machine the inner cavity size to Φ44, and the inner cavity depth is 15mm.

[0040] (3) Finishing inner circle: Set the lathe speed to 190 rpm and finish the inner cavity to the size of The inner cavity depth is Further, a machining is performed on the middle of the top surface of the inner cavity. A 0.5 mm deep dimple (the dimple is part of the thin-walled barrel-shaped part and has no special function).

[0041] (4) Maintaining the above clamping, set the lathe speed to 300 rpm, and rough-process the outer circle to φ49 mm; set the lathe speed to 250 rpm, semi-finish the outer circle to φ48 mm, and cut off the chuck after retaining the length of 19 mm.

[0042] (5) Finishing turning of base A: Position the upper back cap mandrel, tighten the outer circle of the part, process the upper end face size of the part, set the lathe speed to 220 rpm, and ensure the total length

[0043] The mandrel includes a main shaft, the main shaft diameter is The outer circle of the spindle contacts the inner circle of the part to locate the inner circle of the part;

[0044] The lower end of the main shaft has an integrally cast stepped shaft, and the outer peripheral surface of the stepped shaft is provided with an external thread, which is threadedly connected to the back cap;

[0045] The lower end of the stepped shaft has an integrally cast chuck, a mandrel, a back cap, and parts, which are assembled and used for clamping on a machine tool;

[0046] The back cap is in an inverted cylindrical shape, and an internal thread matching the external thread on the core shaft is provided on the inner circumference of the back cap. A circular through hole is provided in the center of the top of the back cap, and the inner wall of the circular through hole (height is 6mm) contacts and positions the outer circle of the part.

[0047] (6) Finish turning the outer surface: Remove the back cap, continue to keep the spindle of the mandrel in contact with the inner circle of the part, use the ejector installed in the back seat of the lathe to axially press the mandrel, and rely on the friction of the inner surface to prevent the radial deformation of the part from exceeding the geometric tolerance requirements. Set the lathe speed to 220 rpm and turn the outer circle size You can get it.

[0048] (7) Check the parallelism and perpendicularity. Relative to the reference plane A, the parallelism of the inner end surface is 0.05 and the perpendicularity of the side wall is 0.04.

[0049] Comparative Example 1

[0050] Compared with Example 1, the only difference is that in step (5) when finishing the base surface A, no back cap is used, and only the mandrel is used for positioning; the specific steps are as follows:

[0051] (1) Cutting material: Φ52mm bar, 48mm long.

[0052] (2) Rough turning of inner circle: Use turning and milling compound equipment, the tool material is YW type carbide, one end of the bar is clamped with a chuck, the chuck length is 25mm, and the other end surface is turned flat. Set the lathe speed to 220 rpm, and rough-machine the inner cavity size to Φ44, and the inner cavity depth is 15mm.

[0053] (3) Finishing inner circle: Set the lathe speed to 190 rpm and finish the inner cavity to the size of The inner cavity depth is Further, a machining is performed on the middle of the top surface of the inner cavity. A pit with a depth of 0.5 mm.

[0054] (4) Maintaining the above clamping, set the lathe speed to 300 rpm, and rough-process the outer circle to φ49 mm; set the lathe speed to 250 rpm, semi-finish the outer circle to φ48 mm, and cut off the chuck after retaining the length of 19 mm.

[0055] (5) Finishing of base surface A: Position the upper mandrel, close to the inner circle of the part, process the upper end surface size of the part, set the lathe speed to 220 rpm, and ensure the total length

[0056] The mandrel comprises a main shaft having a diameter of The outer circle of the spindle contacts the inner circle of the part to locate the inner circle of the part;

[0057] The lower end of the main shaft has an integrally cast stepped shaft, and the outer peripheral surface of the stepped shaft is provided with an external thread, which is threadedly connected to the back cap;

[0058] The lower end of the step shaft is provided with an integrally cast chuck, and the mandrel, the back cap and the parts are assembled and used for clamping on a machine tool.

[0059] (6) Finish turning the outer surface: Continue to keep the spindle of the mandrel in contact with the inner circle of the part, use the ejector installed in the back seat of the lathe to axially press the mandrel, and rely on the friction of the inner surface to prevent the radial deformation of the part from exceeding the geometric tolerance requirements. Set the lathe speed to 220 rpm and turn the outer circle size

[0060] (7) Check the parallelism and verticality. Relative to the reference plane A, the parallelism of the inner end face is 0.07, and the verticality of the side wall is 0.07, both of which do not meet the requirements of the drawing.

[0061] Although the present invention has been described in detail above by general description, specific implementation methods and experiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A method for processing a thin-walled barrel-shaped part made of Permalloy, characterized in that: The following steps are involved: (1) Cutting of rods made of Permalloy; (2) Place the bar into the machine tool, and leave a certain length at either end of the bar as a chuck for clamping. Use a turning tool to flatten the end face of the other end and then turn the inner circle to the inner circle depth and inner diameter required by the design of the thin-walled barrel-shaped part; (3) Keep the above clamping, turn the outer circle, form the outer circle positioning surface, and cut off the chuck; (4) using a mandrel and a back cap to respectively position the inner circle and outer circle of the part obtained in step (3), and then lathe the end face of the end that has not been lathed to the length dimension required by the design of the thin-walled barrel-shaped part; The mandrel comprises a main shaft, the main shaft is contacted and positioned with the inner circle of the part, the lower end of the main shaft has an integrally cast stepped shaft, the outer circumferential surface of the stepped shaft is provided with an external thread, and the lower end of the stepped shaft has an integrally cast chuck; The back cap is in an inverted cylindrical shape, and an internal thread matching the external thread on the core shaft is provided on the inner circumference of the back cap. A circular through hole is provided at the center of the top of the back cap, and the inner wall of the circular through hole contacts and positions the outer circle of the part; (5) The back cap is removed, the part is axially pressed against the mandrel, and the outer diameter is precision-turned to the outer diameter size required by the design of the thin-walled barrel-shaped part.

2. The processing method according to claim 1, characterized in that: In step (2), the inner circle turning includes rough inner circle turning and fine inner circle turning in sequence; The lathe speed of the rough turning inner circle is 200 rpm to 230 rpm, and the rough turning leaves 1mm for the fine turning; The lathe speed for fine turning the inner circle is 180 rpm to 200 rpm.

3. The processing method according to claim 1 or 2, characterized in that: In step (3), the outer circle turning includes rough outer circle turning and semi-finishing outer circle turning in sequence; The lathe speed for rough turning the outer circle is 270 rpm to 320 rpm, and the rough turning allows 1 mm for semi-finishing turning; The lathe speed for semi-finishing outer circle is 230 rpm to 260 rpm, and the allowance for semi-finishing turning to finishing turning is 1 mm.

4. The processing method according to claim 1 or 2, characterized in that: In step (3), the chuck is cut off after leaving a 1.5 mm allowance on the length dimension required by the design.

5. The processing method according to claim 1 or 2, characterized in that: In step (4), the inner wall height of the circular through hole on the back cap is 5 mm to 10 mm.

6. The processing method according to claim 1 or 2, characterized in that: The lathe speed for finishing the outer circle is 200 rpm to 220 rpm.

7. The processing method according to claim 1 or 2, characterized in that: The turning tool of the machine tool is made of YW type hard alloy.

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