Shell nosing process for cover parts

Abstract

The invention relates to the technical field of closing-in machining, and discloses a cover part closing-in process which comprises the following steps: selecting a corresponding inverted conical surface closing-in die according to the specification of a machined cover part; the cover type part is installed on the closing-in die, the closing-in die is installed on a machine tool, then top pressure on the cover type part is reduced, and after resistance is suddenly increased, pressure maintaining is conducted for 30-60 s, and machining is completed. By means of the designed back taper die, machining of cover parts is not limited to lathe work machining, a bench worker can also use the tool for machining, and the machining efficiency is greatly improved; compared with an original closing-in tool, the one-time forming machining qualification rate of the back taper closing-in die is greatly improved, the rework rate is continuously reduced in the using process, at present, the part does not need to be repaired after being machined, and the conformity of the machined part to a product pattern is high.

Description

Technical Field

[0001] The invention relates to the technical field of closing processing, in particular to a closing process for cover-type parts. Background Art

[0002] The mechanical processing of cover parts has high requirements for the conformity of product drawings. In aerospace hydraulic products, cover parts require special tooling and high-intensity physical labor for batch processing due to the material strength, use environment and other characteristics. Therefore, the use of ordinary lathes or benchwork for one-time molding of cover parts is of great positive significance in solving the actual production and processing bottleneck.

[0003] For the protective cover parts in some products, the conformity of their outer dimensions and inner hole dimensions to the drawing requirements has high requirements for the use and assembly of the parts. For larger parts or parts that are easy to clamp, they can be processed by turning or milling to improve the conformity of the part dimensions to the drawing requirements, but for smaller parts or parts that are difficult to clamp, turning or milling cannot be used for processing. The qualified rate of using conventional closing dies is low, the rework rate of parts is high, and repeated processing will affect their fatigue strength performance, and the labor intensity is also high. At the same time, there are certain requirements for the outer surface roughness of such parts. It is inconvenient to disassemble the closing dies after processing. Sometimes, unnecessary collisions and scratches will be caused when disassembling qualified parts, resulting in the re-repair of qualified parts, and even the situation where the dimensions are out of tolerance after re-repair, and the parts are scrapped. Summary of the invention

[0004] The purpose of the present invention is to provide a closing process for cover-type parts, so as to solve the problem that the existing closing process is not suitable for processing cover-type parts with higher requirements and the processing quality is low.

[0005] The present invention is realized by the following technical scheme: a closing process of cover parts, using a closing die with an inverted cone surface for processing, the closing die with an inverted cone surface comprises a supporting mandrel, an inverted cone die, a spring, and a tail cover; the processing technology is:

[0006] Step S1, select a tail cover of appropriate length according to the specifications of the processed parts and covers, and then screw the tail cover into the inverted cone die to ensure that the tail cover is firmly fixed on the inverted cone die. At this time, the tail cover pushes the spring and then pushes the support mandrel to move, so that the limit step on the support mandrel is against the inner hole of the inverted cone die, and the spring is also compressed. At this time, the support mandrel cannot continue to move, and the closing support surface on the support mandrel is at the closing extrusion surface on the inverted cone die;

[0007] Step S2, placing the cover parts to be processed in the gap between the closing support surface and the closing extrusion surface;

[0008] Step S3, installing and fixing the inverted cone die on the machine tool, and then starting to press the cover parts;

[0009] Step S4, when the resistance increases suddenly after the top pressure, stop further top pressure, maintain the top pressure for 30-60 seconds and then remove the top pressure;

[0010] Step S5, after the top pressure disappears, the cover parts are automatically ejected under the action of the spring, and the processor collects the parts, removes the burrs, checks the dimensions, and completes the processing.

[0011] In order to better implement the present invention, further, the taper of the closing extrusion surface is 1°±0.1°.

[0012] In order to better implement the present invention, further, the surface roughness of the closing extrusion surface and the closing support surface is 0.4 microns.

[0013] In order to better realize the present invention, further, the support core shaft is made of 50CrVA, and the hardness after heat treatment is HRC45-51; the inverted cone die is carburized with 1Cr11Ni2W2MoV at the closing extrusion surface, and the hardness is HRC58-62, while the hardness of the remaining non-carburized surfaces on the inverted cone die is HRC35-41.

[0014] In order to better implement the present invention, further, the head diameter of the inverted cone mold is larger than the tail diameter, and the end position of the head of the inverted cone mold is provided with a chamfer.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0016] (1) The present invention uses a unique inverted cone die and matching processing technology to make the processing of cover parts no longer limited to lathe processing. Fitters can also use the tooling to process, greatly improving the processing efficiency;

[0017] (2) Compared with the existing closing tooling, the invention greatly improves the one-time forming qualification rate of the inverted cone closing die in this case, and the rework rate is continuously reduced during use. At present, the parts do not need to be repaired after processing, and the parts after processing are highly compliant with the product drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall process of the present invention.

[0019] Figure 2 It is a cross-sectional view of the overall structure of the closing mold.

[0020] Figure 3 It is a cross-sectional view of the supporting mandrel structure.

[0021] Among them: 101-support mandrel; 102-limiting step; 103-closing support surface; 104-inverted cone die; 105-closing extrusion surface; 106-spring; 107-tail cover. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Embodiment 1:

[0025] This embodiment provides a cover-type parts closing process, specifically as follows Figure 1-Figure 3 As shown, a conical surface closing die is used for processing, which mainly includes the following steps:

[0026] Step S1, select a tail cover 107 of appropriate length according to the specifications of the processed parts and covers, and then screw the tail cover 107 into the inverted cone die 104 to ensure that the tail cover 107 is firmly fixed on the inverted cone die 104. At this time, the tail cover 107 pushes the spring 106 and then pushes the support mandrel 101 to move, so that the limit step 102 on the support mandrel 101 is against the inner hole of the inverted cone die 104, and the spring 106 is also compressed. At this time, the support mandrel 101 cannot continue to move. The closing support surface 103 on the support mandrel 101 is at the closing extrusion surface 105 on the inverted cone die 104;

[0027] Step S2, placing the cover parts to be processed in the gap between the closing support surface 103 and the closing extrusion surface 105;

[0028] Step S3, if the processing is performed on a lathe, the tail of the inverted cone mold 104 is placed on the lathe, and then the inverted cone mold 104 is clamped by three claws, and the cover parts and the supporting mandrel 101 are pushed into the inverted cone mold 104 by the tailstock of the lathe; if the processing is performed by benchwork, the inverted cone mold 104 is placed flat on a drilling machine, and the drilling machine is used to press the cover parts and the supporting mandrel 101 into the inverted cone mold 104;

[0029] Step S4, the inverted cone die 104 is calculated for the specific size of the cover-like parts. When the resistance increases suddenly after the top pressure (when the cover-like parts are closed, they are limited by the closing support surface 103 and the closing extrusion surface 105 and cannot be pushed in further), stop further pressing, maintain the top pressure for 30-60 seconds, and then remove the top pressure;

[0030] Step S5, after the top pressure disappears, the cover parts are automatically ejected under the action of the spring 106, and the processor collects the parts, removes the burrs, checks the dimensions, and completes the processing.

[0031] The inverted cone surface closing die described herein comprises a supporting mandrel 101, an inverted cone die 104, a spring 106, and a tail cover 107. The inverted cone die 104 comprises a head and a tail. The inverted cone die 104 is axially provided with a through hole. A closing extrusion surface 105 is provided at the through hole of the head. The closing extrusion surface 105 is an inner cone surface. The inner cone surface is located on one side of the end of the inverted cone die 104 and has a larger diameter than the other side. A limited step 102 and a closing support surface 103 are provided on the supporting mandrel 101. The closing support surface 103 cooperates with the closing extrusion surface 105 to close the part. The limited step 102 is used to limit the supporting mandrel 101. The supporting mandrel 101 is slidably connected in the through hole of the inverted cone die 104. The tail cover 107 is threadedly connected in the through hole of the inverted cone die 104. The spring 106 is provided between the supporting mandrel 101 and the tail cover 107. The dimensions shown in the drawings are in mm.

[0032] Through the inverted cone die 104 designed in this case, the processing of cover-type parts is no longer limited to lathe processing, and fitters can also use this tooling for processing, which greatly improves the processing efficiency; compared with the original closing die, the one-time molding processing pass rate of the inverted cone closing die is greatly improved, and the rework rate is continuously reduced during use. At present, the parts do not need to be repaired after processing, and the parts after processing are highly compliant with the product drawings.

[0033] Embodiment 2:

[0034] This embodiment further defines the closing extrusion surface 105 based on the above embodiment. Figure 2 As shown, the taper of the closing extrusion surface 105 is 1°±0.1°. In this embodiment, the taper of the closing extrusion surface 105 is selected according to the processed cover-like parts; and the taper can be adaptively selected according to different part processing requirements.

[0035] The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0036] Embodiment 3:

[0037] This embodiment further defines the closing support surface 103 and the closing extrusion surface 105 on the basis of the above embodiment. Figure 2 As shown, the surface roughness of the closing extrusion surface 105 and the closing support surface 103 are both 0.4 microns. This surface roughness is a kind of low processing cost under the standard of mask-like parts processing. If the roughness level is reduced, it cannot meet the mask-like parts processing requirements; and if the roughness level is increased, the production cost will increase.

[0038] The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0039] Embodiment 4:

[0040] The present embodiment further limits the support mandrel 101 and the inverted cone mold 104 on the basis of the above-mentioned embodiment. For the support mandrel 101, considering that wear during use will affect the service life, and the specific size needs to be adjusted according to the part size and the ductility of the part material, the support mandrel 101 is made of 50CrVA, and the hardness after heat treatment is HRC45-51.

[0041] For the inverted cone die 104, only part of it has high wear and service life requirements, and the other parts have relatively lower requirements for heat treatment hardness. Therefore, 1Cr11Ni2W2MoV is carburized at the closing extrusion surface 105 with a hardness of HRC58-62, while the hardness of the other non-carburized surfaces on the inverted cone die 104 is HRC35-41.

[0042] The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0043] Embodiment 5:

[0044] This embodiment further defines the inverted cone mold 104 based on the above embodiment. Figure 2 As shown, the head diameter of the inverted cone mold 104 is larger than the tail diameter, and the end position of the head of the inverted cone mold 104 is provided with a chamfer.

[0045] By reducing the tail diameter, the volume, weight and material cost of the inverted cone die 104 are effectively reduced. The chamfer is set to make room for the machine tool to prevent interference during the processing.

[0046] The other parts of this embodiment are the same as those of the above embodiment and will not be described in detail.

[0047] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A closing process for cover parts, characterized in that: A reverse cone-shaped closing die is used for processing, wherein the reverse cone-shaped closing die comprises a supporting mandrel (101), a reverse cone die (104), a spring (106), and a tail cover (107); the processing technology is as follows: Step S1, select a tail cover (107) of appropriate length according to the specifications of the processed parts and covers, and then screw the tail cover (107) into the inverted cone mold (104), ensuring that the tail cover (107) is firmly fixed on the inverted cone mold (104), at this time, the tail cover (107) pushes the spring (106) and then pushes the support mandrel (101) to move, so that the limit step (102) on the support mandrel (101) is against the inner hole of the inverted cone mold (104), and the spring (106) is also compressed. At this time, the support mandrel (101) cannot continue to move. The closing support surface (103) on the support mandrel (101) is at the closing extrusion surface (105) on the inverted cone mold (104); Step S2, placing the cover parts to be processed in the gap between the closing support surface (103) and the closing extrusion surface (105); Step S3, installing and fixing the inverted cone mold (104) on the machine tool, and then starting to press the cover parts; Step S4, when the resistance increases suddenly after the top pressure, stop further top pressure, maintain the top pressure for 30-60 seconds and then remove the top pressure; Step S5, after the top pressure disappears, the cover parts are automatically ejected under the action of the spring (106), and the processor collects the parts, removes the burrs, checks the dimensions, and completes the processing.

2. A cover-type parts closing process according to claim 1, characterized in that: The taper of the closing extrusion surface (105) is 1°±0.1°.

3. A cover-type parts closing process according to claim 1, characterized in that: The surface roughness of the closing extrusion surface (105) and the closing support surface (103) is 0.4 micrometers.

4. A cover-type parts closing process according to claim 1, characterized in that: The support mandrel (101) is made of 50CrVA, with a hardness of HRC45-51 after heat treatment; the inverted cone die (104) is carburized with 1Cr11Ni2W2MoV at the closing extrusion surface (105), with a hardness of HRC58-62, while the hardness of the remaining non-carburized surfaces on the inverted cone die (104) is HRC35-41.

5. The closing process of cover parts according to claim 1, characterized in that: The head diameter of the inverted cone die (104) is larger than the tail diameter, and a chamfer is arranged at the end position of the head of the inverted cone die (104).

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