Positioning tool for thin-walled cabin and processing method of thin-walled cabin electric processing groove

Abstract

The present application relates to a kind of positioning tool of thin-walled cabin and the processing method of thin-walled cabin electric processing groove.Processing tool includes locating block and fork-shaped pressing block, the outer end surface of locating block has first step surface, and locating block is fixedly connected with base portion;Fork-shaped pressing block includes base portion and multiple pressing portions, and multiple pressing portions are enclosed with base portion and form the space to be processed, and the outer end surface of each pressing portion has second step surface;The middle part of thin-walled cabin is extended and provided with first center hole, and one end of thin-walled cabin has the end surface to be processed, and the end surface to be processed is used to process electric processing groove, when locating block part is located in first center hole, thin-walled cabin is respectively abutted on first step surface and multiple second step surfaces relative to two ends, and the end surface to be processed is located in the space to be processed.Such solution existing thin-walled cabin in the process of electric processing groove is unevenly stressed, so that in clamping, it appears skew, leading to the problem that the accuracy of detection is poor after thin-walled cabin processing is taken down.

Description

Technical Field

[0001] This invention relates to the field of positioning tooling technology for thin-walled cabins, and more specifically, to a positioning tooling for thin-walled cabins and a method for machining the EDM groove of thin-walled cabins. Background Technology

[0002] The thin-walled hull is a crucial component of the rudder system. It is made of 2A12-T4 aluminum alloy rods, has a thin-walled cylindrical structure, an outer diameter of φ90mm, and a wall thickness of 2.5mm at its thinnest point. Figure 1 As shown, the width The groove is an important characteristic dimension. The design requires the groove to have a symmetry of 0.03 with the outer circle datum. Since the root of the groove is in a clean state and is only 1mm deep relative to the inner hole wall, the groove is machined by electrical discharge machining.

[0003] When machining this groove using electrical discharge machining (EDM), in order to determine the orientation and the center position of the thin-walled chamber, the existing design involves fabricating a fixed mold clamping device with a φ90 outer diameter, using a φ4.5H7mm hole in the GG view as the orientation hole for EDM. Since the fixing element lacks elasticity, two screw holes are made on its circumference to connect and position the fixing element to the thin-walled cabin. However, due to the thin wall thickness of the cabin, tightening the two screws can easily cause deformation. Furthermore, the orientation section has a wall thickness of only 3.75mm, and the outer diameter of the thin-walled cabin is relatively large. Relying solely on the 3.75mm wall thickness for orientation makes electrical discharge machining (EDM) difficult. Uneven stress can easily occur during the slotting process, leading to tilting during clamping. Consequently, the accuracy of the slot dimensions and symmetry can be poor after the thin-walled cabin is removed from the machining process, resulting in a low pass rate for the machined thin-walled cabin. Summary of the Invention

[0004] To address the problem that uneven stress during the EDM (Electrical Discharge Machining) process of existing thin-walled cabins causes tilting during clamping, resulting in poor inspection accuracy after the thin-walled cabins are removed from the machined parts, this invention provides a positioning fixture for thin-walled cabins and a machining method for EDM grooves in thin-walled cabins.

[0005] In a first aspect, the present invention provides a positioning fixture for a thin-walled cabin; the positioning fixture includes a positioning block and a fork-shaped pressure block, wherein, along the height direction, the outer end face of the positioning block is formed with a first step, the first step has a first step surface on the side facing the fork-shaped pressure block, and the positioning block is provided with a first assembly structure on the side facing the fork-shaped pressure block;

[0006] The fork-shaped pressing block includes a base portion and a plurality of pressing portions extending along one side of the base portion. The plurality of pressing portions are symmetrically arranged along the circumference of the base portion. There is a gap between two adjacent pressing portions, and the plurality of pressing portions and the base portion together form a processing space. Along the height direction, a second step is formed on the outer end face of each pressing portion. Each second step has a second step surface on the side facing the base portion. A second assembly structure is provided on the base portion.

[0007] Along the height direction, a first central hole is provided in the middle of the thin-walled cabin, and one end of the thin-walled cabin has a section to be processed. The section to be processed has a partially provided end face to be processed. An electrical discharge machining (EDM) groove is preset on the end face to be processed near the side where the first central hole is located. The EDM groove extends toward the interior of the section to be processed along the height direction and is connected to the first central hole.

[0008] When the positioning block is located in the first central hole, the other end of the thin-walled cabin abuts against the first step surface, the base is located in the first central hole, one end of the thin-walled cabin abuts against multiple second step surfaces, and the end face to be processed is located in the processing space. The first assembly structure and the second assembly structure are fixedly connected.

[0009] In some embodiments, the positioning block includes a first positioning part and a second positioning part connected together, and the end face of the first positioning part facing the side where the second positioning part is located forms the first stepped surface;

[0010] The first positioning part has a second central hole extending along the height direction in the middle, and the second positioning part has a third central hole extending along the height direction in the middle. The second central hole and the third central hole are connected. The first assembly structure is provided in the middle of the second positioning part facing the side where the fork-shaped pressure block is located.

[0011] When the first assembly structure and the second assembly structure are fixedly connected, the second positioning part is located in the first central hole, and there is a first gap L between the outer peripheral surface of the second positioning part and the side wall of the first central hole. The value range of the first gap L is: 0.004 mm ≤ L ≤ 0.006 mm.

[0012] In some embodiments, the crimping portion includes a first crimping portion integrally connected to the base portion and a second crimping portion connected to the other end of the first crimping portion. The other end of the second crimping portion extends away from the side where the first crimping portion is located along the radial direction. Along the height direction, the second crimping portion forms a second stepped surface on the side facing the base portion.

[0013] There is a second gap between the outer peripheral surface of the base portion and the sidewall of the first central hole, and the distance of the second gap is greater than the distance of the first gap.

[0014] In some embodiments, the positioning fixture further includes an auxiliary measuring block, which is detachably fixed to the section to be processed. The auxiliary measuring block is located within the processing space and abuts against the side wall of the first central hole. The auxiliary measuring block has an auxiliary processing end face, which is arranged opposite to the end face to be processed. An auxiliary processing groove is preset on the side of the auxiliary processing end face near the end face to be processed, and the auxiliary processing groove is symmetrically arranged with the electrical discharge machining groove.

[0015] In some embodiments, the first positioning part is provided with a guide part, and in the height direction, the guide part is aligned with the end face to be processed.

[0016] In some embodiments, the other end of the thin-walled cabin has a fixed processing section, the fixed processing section is provided with a plurality of guide holes, and the second positioning part is provided with a plurality of directional holes, each of the directional holes being aligned one-to-one with the guide holes;

[0017] The positioning fixture also includes multiple positioning pins, each of which passes through a guide hole and an orientation hole.

[0018] In some embodiments, a positioning line is defined, the positioning line passing through the center line of the first central hole, and the center lines of at least two of the orientation holes coincide with the positioning line;

[0019] The guide portion has a guide surface, and there is a positioning angle α between the positioning line and the guide surface, wherein the positioning angle α is less than 90 degrees.

[0020] In some embodiments, the positioning fixture further includes a first connector;

[0021] The first assembly structure is a first assembly hole, which communicates with the third center hole;

[0022] The second assembly structure is a second assembly hole, and the first connector passes through the first assembly hole and the second assembly hole.

[0023] In some embodiments, a plurality of the crimping portions are evenly distributed around the outer edge of the base portion.

[0024] On the other hand, the present invention also discloses a method for machining an electrical discharge machining (EDM) groove for a thin-walled chamber, wherein the method utilizes the aforementioned positioning fixture for the thin-walled chamber to position the thin-walled chamber on an EDM machine tool; the method includes:

[0025] The thin-walled cabin is placed in the positioning fixture, and the end face to be processed is located within the processing space;

[0026] The positioning block is detachably and fixedly connected to the EDM machine tool along the height direction, and the end face to be processed is oriented toward the automatic feed adjustment device;

[0027] The electrode of the automatic feed adjustment device is used to process the thin-walled chamber using the electrical discharge machining (EDM) groove.

[0028] To address the problem of uneven stress distribution during EDM of existing thin-walled chambers, which leads to tilting during clamping and consequently poor inspection accuracy after removal from the machined chamber, this invention offers the following advantages:

[0029] The technical solution of the present invention can achieve relatively secure positioning of thin-walled cabins, and ensure that the preload applied to the thin-walled cabins by the fork-shaped pressure blocks is the same during the positioning process, without the need to design a relatively complex positioning structure for the thin-walled cabins. Attached Figure Description

[0030] Figure 1 A schematic diagram of the thin-walled cabin being clamped onto a positioning fixture is shown.

[0031] Figure 2 It shows Figure 1 The cut line shown is a cross-sectional view passing through the EDM tank and auxiliary machining tank along the axis of the thin-walled chamber.

[0032] Figure 3 It shows Figure 1 A schematic diagram of the positioning block shown in the figure;

[0033] Figure 4 It shows Figure 1 A schematic diagram of the fork-shaped pressure block shown in the figure;

[0034] Figure 5 It shows Figure 4 The diagram shows a structural schematic of the fork-shaped pressure block at another angle.

[0035] Reference numerals: 01-Thin-walled cabin; 11-Electrical discharge machining groove; 02-Positioning fixture; 21-Positioning block; 211-First positioning part; 2111-Second center hole; 2112-Guide part; 212-Second positioning part; 2121-Third center hole; 2122-Orientation hole; 213-First stepped surface; 2123-First assembly structure; 22-Fork-shaped pressure block; 221-Base part; 2211-Second assembly structure; 222-Crimping part; 2221-First pressing part; 2222-Second pressing part; 2223-Second stepped surface; 23-Auxiliary measuring block; 231-Auxiliary machining groove; 24-Positioning pin; 252-Guide surface; 26-Electrode; 27-First connector. Detailed Implementation

[0036] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, and are not intended to imply any limitation on the scope of the disclosure.

[0037] As used herein, the term "comprising" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments and are not intended to limit the indicated devices, elements, or components to having a specific orientation or being constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientations or positional relationships; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances. In addition, the terms "installed", "set up", "equipped with", "connected", and "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Furthermore, the terms "first," "second," etc., are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0038] This embodiment discloses a positioning fixture 02 for a thin-walled cabin 01, such as... Figures 1 to 4 As shown, the positioning fixture 02 includes a positioning block 21 and a fork-shaped pressing block 22. Along the height direction, the outer end face of the positioning block 21 forms a first step, and the first step has a first step surface 213 on the side facing the fork-shaped pressing block 22. The positioning block 21 is provided with a first assembly structure 2123 on the side facing the fork-shaped pressing block 22.

[0039] The fork-shaped pressing block 22 includes a base portion 221 and a plurality of pressing portions 222 extending along one side of the base portion 221. The plurality of pressing portions 222 are symmetrically arranged along the circumference of the base portion 221. There is a gap between two adjacent pressing portions 222, and the plurality of pressing portions 222 and the base portion 221 enclose a processing space. Along the height direction, a second step is formed on the outer end face of each pressing portion 222. Each second step has a second step surface 2223 on the side facing the base portion 221. A second assembly structure 2211 is provided on the base portion 221.

[0040] Along the height direction, a first central hole is provided in the middle of the thin-walled cabin 01, and one end of the thin-walled cabin 01 has a section to be processed. The section to be processed has a partially provided end face to be processed. An electrical discharge machining groove 11 is preset on the end face to be processed near the side where the first central hole is located. The electrical discharge machining groove 11 extends toward the interior of the section to be processed along the height direction and communicates with the first central hole.

[0041] When the positioning block 21 is partially located in the first central hole, the other end of the thin-walled cabin 01 abuts against the first step surface 213, the base part 221 is located in the first central hole, one end of the thin-walled cabin 01 abuts against a plurality of second step surfaces 2223, and the end face to be processed is located in the processing space, and the first assembly structure 2123 and the second assembly structure 2211 are fixedly connected.

[0042] In this embodiment, a positioning fixture 02 is provided for positioning a thin-walled compartment 01 on an electrical discharge machine tool. By fixing the first assembly structure 2123 and the second assembly structure 2211 together, the thin-walled compartment 01 abuts against the first step surface 213 and a plurality of second step surfaces 2223 at its two opposite ends, and the end face to be processed is located within the processing space. In this application, the end of the thin-walled compartment 01 located on the side where the section to be processed is located abuts against the second step surface 2223 of a plurality of pressing portions 222 of the fork-shaped pressure block 22, so that the end face to be processed, which is partially provided on the section to be processed, is located within the processing space. The end face to be processed is located within the gap between two adjacent pressing portions 222, so as to facilitate the subsequent electrical discharge machining of the preset electrical discharge groove 11 on the end face to be processed on the electrical discharge machine tool.

[0043] Furthermore, the other end of the thin-walled compartment 01 abuts against the first stepped surface 213 to fix and position the thin-walled compartment 01 on the first stepped surface 213 of the positioning block 21. Since part of the positioning block 21 extends into the first central hole of the thin-walled compartment 01, the stability of the thin-walled compartment 01 fixed to the positioning block 21 is further improved. Moreover, since the multiple pressing parts 222 are symmetrically arranged along the circumference of the base part 221, when machining the preset EDM groove 11, the multiple pre-tightening forces transmitted by the fork-shaped pressing block 22 to the thin-walled compartment 01 through the multiple pressing parts 222 are all the same, achieving a relatively tight positioning of the thin-walled compartment 01 without requiring a complex positioning structure for the thin-walled compartment 01.

[0044] In this embodiment, the first assembly structure 2123 and the second assembly structure 2211 are movable relative to each other along the height direction. The first assembly structure 2123 may have multiple latching portions extending around the periphery of the positioning block 21 towards the side where the fork-shaped pressure block 22 is located. The second assembly structure 2211 may have multiple hook portions extending around the periphery of the base portion 221 towards the side where the positioning block 21 is located, with each hook portion corresponding to one of the latching portions. In this application, the connection between the first assembly structure 2123 and the second assembly structure 2211 may be a threaded connection, a snap-fit ​​connection (e.g., a pin connection), a locking connection, or other feasible connection methods, and this application is not limited to these methods.

[0045] Specifically, through the above-mentioned configuration, a connecting structure is added between the positioning block 21 and the base 221, making the connection between the positioning block 21 and the fork-shaped pressure block 22 more secure. The latching segment of the latching part can be a trapezoidal spur gear structure, and the latching segment of the hook part can be a single trapezoidal shape. This allows the positioning block 21 and the fork-shaped pressure block 22 to engage by pushing the fork-shaped pressure block 22, causing the latching segment of the hook part to move along the height direction on the latching segment of the latching part. This allows the latching segment of the hook part to engage with any position on the latching segment of the latching part, thereby adjusting the positioning fixture 02 to adapt to thin-walled cabins 01 of different lengths and dimensions, thus improving the versatility of the positioning fixture 02.

[0046] In some embodiments, the positioning block 21 includes a first positioning part 211 and a second positioning part 212 connected together, and the end face of the first positioning part 211 facing the side where the second positioning part 212 is located forms the first stepped surface 213.

[0047] The first positioning part 211 has a second central hole 2111 extending along the height direction in the middle, and the second positioning part 212 has a third central hole 2121 extending along the height direction in the middle. The second central hole 2111 and the third central hole 2121 are connected. The first assembly structure 2123 is provided in the middle of the second positioning part 212 facing the side where the fork-shaped pressure block 22 is located.

[0048] When the first assembly structure 2123 and the second assembly structure 2211 are fixedly connected, the second positioning part 212 is located in the first central hole, and there is a first gap L between the outer peripheral surface of the second positioning part 212 and the side wall of the first central hole. The value range of the first gap L is: 0.004 mm ≤ L ≤ 0.008 mm.

[0049] Furthermore, the crimping portion 222 includes a first crimping portion 2221 integrally connected to the base portion 221, and a second crimping portion 2222 connected to the other end of the first crimping portion 2221. The other end of the second crimping portion 2222 extends away from the side where the first crimping portion 2221 is located along the radial direction. Along the height direction, the second crimping portion 2222 has a second stepped surface 2223 formed on the side facing the base portion 221.

[0050] There is a second gap between the outer peripheral surface of the base portion 221 and the sidewall of the first central hole, and the distance of the second gap is greater than the distance of the first gap.

[0051] Furthermore, the positioning fixture 02 also includes a first connecting member 27;

[0052] The first assembly structure 2123 is a first assembly hole, which is connected to the third center hole 2121;

[0053] The second assembly structure 2211 is a second assembly hole, and the first connector 27 passes through the first assembly hole and the second assembly hole.

[0054] Furthermore, the plurality of the crimping portions 222 are evenly distributed around the outer edge of the base portion 221.

[0055] In this embodiment, through the above-described configuration, a certain gap is formed between the positioning block 21 located in the first central hole and the inner wall surface of the thin-walled chamber 01. This gap is called the first gap. When the value of the first gap L is within the range of 0.004 mm ≤ L ≤ 0.006 mm, by adjusting the connection relationship between the fork-shaped pressure block 22 and the positioning block 21, the thin-walled chamber 01 can be aligned on the first step surface 213 of the first positioning part 211, ensuring that the runout of the alignment end face is within 0.012 mm. This guarantees stable and reliable clamping. At the same time, the above-described clamping method also avoids deformation of the thin-walled chamber 01 caused by pressing the outer circle of the thin wall, further ensuring the dimensional accuracy requirements of the EDM groove 11. In this application, the value of the first gap L is preferably 0.005 mm.

[0056] Furthermore, the first connector 27 can be a bolt, a pin, or other feasible structure. In this application, a bolt is preferred, that is, the first assembly structure 2123 and the second assembly structure 2211 are threadedly connected by a bolt.

[0057] Furthermore, through the above-mentioned configuration, when the thin-walled cabin 01 is fixed to the positioning block 21 and the fork-shaped pressure block 22 via the first assembly structure 2123 and the second assembly structure 2211, the force applied by the fork-shaped pressure block 22 to the thin-walled cabin 01 on the side where each pressing part 222 is located through the first connector 27 tends to be the same. This makes it possible for the multiple forces applied to the thin-walled cabin 01 to act evenly on the first step surface 213 of the positioning block 21 through the thin-walled cabin 01 to be more balanced, thereby further realizing and reducing the impact on the accurate positioning of the thin-walled cabin 01.

[0058] Furthermore, by providing a second central hole 2111 in the middle of the first positioning part 211, and a third central hole 2121 in the middle of each of the second positioning parts 212, and by providing a first assembly structure 2123 as a first assembly hole, the first assembly hole and the third central hole 2121 are connected, so that the first connecting piece 27 can quickly pass through the second central hole 2111 and the third central hole 2121 to achieve a threaded connection with the first assembly hole. At the same time, the other end of the first connecting piece 27 passes through the second assembly hole and is threadedly connected with it to achieve a fixed connection between the positioning block 21 and the fork-shaped pressure block 22.

[0059] In some embodiments, the positioning fixture 02 further includes an auxiliary measuring block 23, which is detachably fixed to the section to be processed. The auxiliary measuring block 23 is located within the processing space and abuts against the side wall of the first central hole. The auxiliary measuring block 23 has an auxiliary processing end face, which is arranged opposite to the end face to be processed. An auxiliary processing groove 231 is preset on the side of the auxiliary processing end face near the end face to be processed. The auxiliary processing groove 231 is symmetrically arranged with the electrical discharge machining groove 11.

[0060] Furthermore, the first positioning part 211 is provided with a guide part 2112, which is aligned with the end face to be processed along the height direction.

[0061] Furthermore, the other end of the thin-walled cabin 01 has a fixed processing section, on which a plurality of guide holes are provided, and the second positioning part 212 is provided with a plurality of directional holes 2122, each of the directional holes 2122 being aligned with the guide holes in a one-to-one manner;

[0062] The positioning fixture 02 also includes a plurality of positioning pins 24, each of which is inserted into a guide hole and an orientation hole 2122.

[0063] Furthermore, a positioning line is defined, which passes through the center line of the first central hole, and the center lines of at least two of the orientation holes 2122 coincide with the positioning line;

[0064] The guide portion 2112 has a guide surface 252, and there is a positioning angle α between the positioning line and the guide surface 252, wherein the positioning angle α is less than 90 degrees.

[0065] In this embodiment, since the EDM groove 11 has a radial depth of only 1 mm, it is impossible to detect whether the symmetry meets the requirements. Therefore, an auxiliary measuring block 23 is added. This auxiliary measuring block 23 is fixedly connected to the thin-walled chamber 01 in the 180° direction of the EDM groove 11 by screws. When EDMing the thin-walled chamber 01, an auxiliary machining groove 231 of the same size is simultaneously machined on the auxiliary measuring block 23, so that the groove wall of the EDM groove 11 of the thin-walled chamber 01 and the groove wall of the auxiliary machining groove 231 on the auxiliary measuring block 23 are on the same straight line. Along the height direction, for measuring and detecting symmetry, the two sides of the EDM groove 11 and the two sides of the auxiliary machining groove 231 on the auxiliary measuring block 23 are straightened to form two straight lines to facilitate the detection of symmetry. In this application, since the multiple pressing parts 222 are symmetrically arranged along the circumference of the base part 221, the auxiliary machining groove 231 and the EDM groove 11 can be symmetrically arranged.

[0066] Furthermore, the second positioning part 212 is provided with multiple directional holes 2122 around the multiple guide holes on the thin-walled cabin 01, with each directional hole 2122 corresponding to a guide hole. Through the above arrangement, the positioning pin 24 can be inserted into one guide hole and one directional hole 2122 to achieve both orientation and ensure the force balance of the thin-walled cabin 01.

[0067] Furthermore, a guide portion 2112 is provided on the first positioning part 211. This guide portion 2112 is aligned with the end face to be processed to guide the thin-walled cabin 01 onto the positioning block 21, thereby improving assembly efficiency. In this application, the guide portion 2112 can be formed on the outer surface of the end of the first positioning part 211 away from the second center hole 211 along the height direction. The guide portion 2112 has a guide surface 252, which forms a positioning angle α with the positioning line to facilitate the orientation alignment of the thin-walled cabin 01. In this application, since the spindle of the EDM machine tool cannot rotate, the guide portion 2112 used for alignment must be in the same orientation as the EDM groove 11.

[0068] This application also provides a method for machining a workpiece by turning, wherein the method utilizes the positioning fixture 02 of the aforementioned thin-walled chamber 01 to position the thin-walled chamber 01 on an electrical discharge machine tool; the method includes:

[0069] The thin-walled cabin 01 is placed in the positioning fixture 02, and the end face to be processed is located within the processing space;

[0070] The positioning block 21 is detachably and fixedly connected to the EDM machine tool along the height direction, and the end face to be processed is set towards the automatic feed adjustment device;

[0071] The electrode 26 of the automatic feed adjustment device is used to process the thin-walled cabin 01 using the electrical discharge machining (EDM) groove 11.

[0072] In this embodiment, the above processing method can be used to position and clamp the thin-walled cabin 01 onto the positioning fixture 02, thereby enabling the EDM machine tool to perform EDM groove 11 processing on the thin-walled cabin 01.

[0073] In this embodiment, the positioning block 21 is The outer circle is fitted with the φ84H7 hole of the thin-walled cabin 01. The B reference surface of the positioning block 21 serves as the clamping and positioning surface, that is, the plane where the center lines of each orientation hole 2122 coincide is the B reference surface. The two φ4.5H7 holes are orientation holes 2122. The two positioning pins 24 are inserted into the two orientation holes 2122 respectively to both orient and ensure the force balance of the thin-walled cabin 01. The guide part 2112 is machined on the first positioning part 211 of the positioning block 21. The angle between the guide surface of the guide part 2112 and the positioning line where the center lines of the two orientation holes 2122 coincide is 42°, which is the EDM groove 11 of the thin-walled cabin 01. The guide portion 2112 is used to achieve orientation alignment. Since the spindle of the EDM machine tool cannot rotate, the guide portion 2112 used for alignment must be in the same position as the EDM groove 11.

[0074] Furthermore, since the fork-shaped pressure block 22 not only needs to press the end face, but also needs to leave space for the dial indicator to calibrate the outer circle reference of the thin-walled cabin 01 and the slotting space for the auxiliary measuring block 23 in the 180° direction, the fork-shaped pressure block 22 is designed as a hollow, four-part fork-shaped structure (see...). Figure 4 Its second mounting hole is used to connect screws or nuts, and the positioning block 21 and the fork-shaped pressure block 22 can be connected through the second mounting hole.

[0075] Furthermore, the outer arc of the auxiliary measuring block 23 fits against the wall of the φ84H7 hole in the thin-walled chamber 01, and the positions of the two threaded holes on the arc correspond to the EDM groove 11 of the thin-walled chamber 01. The positions of the two φ4.5 holes in the 180° direction. The auxiliary measuring block 23 is connected to the thin-walled cabin 01 using two screws.

[0076] Principle Explanation: The process specification tightens the coaxiality of the inner hole of the thin-walled chamber 01φ84H7 and its outer circle φ90 of the quasi-A to φ0.01. A reference conversion method is adopted. The clamping is performed by controlling the clearance between the positioning block 21 and the φ84H7 hole of the thin-walled chamber 01 within 0.012. The two φ4.5H7 guide holes in the 180° direction on the thin-walled chamber 01 are used for orientation, the end face of the thin-walled chamber 01 is used for positioning, and the two positioning pins 24 determine the direction. The direction of the EDM groove 11 is found through the guide part 2112 of the positioning block 21. The fork-shaped pressure block 22 presses the end face of the thin-walled cabin 01 through the first connector 27, and connects to the positioning block 21 at the same time. In this way, the two end faces of the thin-walled cabin 01 are clamped and fixed. At the same time, two 180° directional holes 2122 are used for orientation to avoid the thin-walled cabin 01 from tilting due to uneven force on the thin-walled cabin 01 during the processing, which would cause the size and symmetry of the EDM groove 11 to exceed the tolerance.

[0077] Action Relationship Description: By pressing the B reference surface of the positioning block 21 with a pressure plate, the positioning block 21 is pressed onto the worktable of the EDM machine. The runout of the positioning block 21 is aligned to be no greater than 0.006. The purpose is to place the guide part 2112 of the positioning block 21 on the coordinate axis of the EDM machine. Then, the φ84H7 hole (i.e., the first center hole) of the thin-walled chamber 01 is inserted into the positioning block 21. The guide hole of the thin-walled chamber 01 is aligned with the orientation hole 2122 of the positioning block 21, and the positioning pin 24 is inserted. Next, two screws are used to install the auxiliary measuring block 23 on the opposite side of the EDM groove 11 to be machined. Finally, the positioning block 21 and the fork-shaped pressure block 22 are tightened with the first connector 27, thereby pressing the end face of the thin-walled chamber 01. Using the automatic alignment function of the EDM machine, a dial indicator touches four high points on the outer diameter of the thin-walled chamber 01 reference Aφ90 (the space left by the fork-shaped pressure block 22 is part of the end face of the thin-walled chamber 01 in the space to be processed). The outer diameter runout is aligned to be no greater than φ0.012. After the reference is aligned, the electrode 26 is mounted on the spindle of the EDM machine, i.e., on the automatic feed adjustment device. The alignment electrode 26 is straightened, and the electrode 26 performs layered translational machining of the EDM groove 11 of the thin-walled chamber 01 from top to bottom. Simultaneously, auxiliary machining grooves 231 of the same size are machined on the 180° auxiliary measuring block 23. After processing, the electrode 26 is removed from the positioning block 21, and the thin-walled chamber 01 with the auxiliary measuring block 23 is subjected to symmetry measurement. After the measurement is completed, the auxiliary measuring block 23 is removed. In this application, the automatic feed adjustment device drives the electrode 26 to move in the processing space so as to simultaneously process the EDM groove 11 of the section to be processed and the auxiliary processing groove 231 of the auxiliary measuring block 23, so as to accurately measure the symmetry of the EDM groove 11 of the thin-walled chamber 01 and improve the processing efficiency.

[0078] In summary, the above structural design allows for a relatively secure positioning of the thin-walled cabin, ensuring that the preload applied to the thin-walled cabin by the fork-shaped pressure block is uniform during the positioning process, and eliminating the need for a complex positioning structure for the thin-walled cabin.

[0079] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0080] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A positioning fixture for a thin-walled cabin, characterized in that, The positioning fixture includes a positioning block and a fork-shaped pressing block. Along the height direction, the outer end face of the positioning block forms a first step, the first step has a first step surface on the side facing the fork-shaped pressing block, and the positioning block is provided with a first assembly structure on the side facing the fork-shaped pressing block. The fork-shaped pressing block includes a base portion and a plurality of pressing portions extending along one side of the base portion. The plurality of pressing portions are symmetrically arranged along the circumference of the base portion. There is a gap between two adjacent pressing portions, and the plurality of pressing portions and the base portion together form a processing space. Along the height direction, a second step is formed on the outer end face of each pressing portion. Each second step has a second step surface on the side facing the base portion. A second assembly structure is provided on the base portion. Along the height direction, a first central hole is provided in the middle of the thin-walled cabin, and one end of the thin-walled cabin has a section to be processed. The section to be processed has a partially provided end face to be processed. An electrical discharge machining (EDM) groove is preset on the end face to be processed near the side where the first central hole is located. The EDM groove extends toward the interior of the section to be processed along the height direction and is connected to the first central hole. When the positioning block is located in the first central hole, the other end of the thin-walled cabin abuts against the first step surface, the base is located in the first central hole, one end of the thin-walled cabin abuts against multiple second step surfaces, and the end face to be processed is located in the processing space. The first assembly structure and the second assembly structure are fixedly connected. The positioning fixture also includes an auxiliary measuring block, which is detachably fixed to the section to be processed. The auxiliary measuring block is located in the processing space and abuts against the side wall of the first central hole. The auxiliary measuring block has an auxiliary processing end face, which is opposite to the end face to be processed. An auxiliary processing groove is preset on the side of the auxiliary processing end face near the end face to be processed, and the auxiliary processing groove is symmetrically arranged with the electrical discharge machining groove.

2. The positioning fixture for the thin-walled cabin as described in claim 1, characterized in that, The positioning block includes a first positioning part and a second positioning part connected together, and the end face of the first positioning part facing the side where the second positioning part is located forms the first stepped surface. The first positioning part has a second central hole extending along the height direction in the middle, and the second positioning part has a third central hole extending along the height direction in the middle. The second central hole and the third central hole are connected. The first assembly structure is provided in the middle of the second positioning part facing the side where the fork-shaped pressure block is located. When the first assembly structure and the second assembly structure are fixedly connected, the second positioning part is located in the first central hole, and there is a first gap L between the outer peripheral surface of the second positioning part and the side wall of the first central hole. The value range of the first gap L is: 0.004 mm ≤ L ≤ 0.006 mm.

3. The positioning fixture for the thin-walled cabin as described in claim 2, characterized in that, The crimping portion includes a first crimping portion integrally connected to the base portion, and a second crimping portion connected to the other end of the first crimping portion. The other end of the second crimping portion extends away from the side where the first crimping portion is located along the radial direction. Along the height direction, the second crimping portion forms a second stepped surface on the side facing the base portion. There is a second gap between the outer peripheral surface of the base portion and the sidewall of the first central hole, and the distance of the second gap is greater than the distance of the first gap.

4. The positioning fixture for the thin-walled cabin as described in claim 2, characterized in that, The first positioning part is provided with a guide part, and in the height direction, the guide part is aligned with the end face to be processed.

5. The positioning fixture for the thin-walled cabin as described in claim 4, characterized in that, The other end of the thin-walled cabin has a fixed processing section, on which a plurality of guide holes are provided, and the second positioning part is provided with a plurality of directional holes, each of the directional holes being aligned one-to-one with the guide holes; The positioning fixture also includes multiple positioning pins, each of which passes through a guide hole and an orientation hole.

6. The positioning fixture for the thin-walled cabin as described in claim 5, characterized in that, A positioning line is defined, the positioning line passing through the center line of the first central hole, and the center lines of at least two of the orientation holes coincide with the positioning line; The guide portion has a guide surface, and the positioning line and the guide surface have a positioning angle α, the angle of which is less than 90 degrees.

7. The positioning fixture for the thin-walled cabin as described in claim 2, characterized in that, The positioning fixture also includes a first connector; The first assembly structure is a first assembly hole, which communicates with the third center hole; The second assembly structure is a second assembly hole, and the first connector passes through the first assembly hole and the second assembly hole.

8. The positioning fixture for the thin-walled cabin as described in claim 1, characterized in that, The plurality of the pressing portions are evenly distributed around the outer edge of the base portion.

9. A method for machining an electrical discharge machining (EDM) groove in a thin-walled chamber, characterized in that, The method utilizes the positioning fixture for the thin-walled chamber as described in any one of claims 1-8 to position the thin-walled chamber on an electrical discharge machine tool; the method includes: The thin-walled cabin is placed in the positioning fixture, and the end face to be processed is located within the processing space; The positioning block is detachably and fixedly connected to the EDM machine tool along the height direction, and the end face to be processed is oriented toward the automatic feed adjustment device; The electrode of the automatic feed adjustment device is used to process the thin-walled chamber using the electrical discharge machining (EDM) groove.

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