Method for machining a combination hole

Abstract

The present disclosure provides a processing method of combined holes, belonging to the technical field of mechanical processing. The processing method comprises: processing a plurality of parts in each part of the plurality of parts to form a bottom hole which is communicated with each other, and the axis direction of the bottom hole is the same as the stacking direction; processing the bottom hole of all parts in the Nth set to form a pin hole, and processing one end of the part closest to the Nth set in the N+1th set adjacent to the Nth set to form a counterbore in the part closest to the Nth set in the N+1th set, and the inner diameter of the end of the counterbore towards the pin hole is coaxial with the pin hole and has the same inner diameter; removing the parts in the Nth set; and processing the bottom hole of all parts in the N+1th set according to the counterbore to form a pin hole. The present disclosure can improve the processing precision of combined holes.

Description

Technical Field

[0001] This disclosure belongs to the field of machining technology, and specifically relates to a method for machining combined holes. Background Technology

[0002] Stacked workpieces are workpieces composed of multiple parts made of various materials (for example, three parts made of two different materials, two of which are made of the same material) assembled and stacked together in a specific direction. When drilling at the stacking position of stacked workpieces, the differences in the physical and mechanical properties of the different materials often lead to problems such as cutting force fluctuations and tool runout. As a result, the dimensional accuracy, positional accuracy, and surface quality of the drilled composite holes (the holes formed by the axial connection of the through holes of the various parts) are difficult to meet the requirements of machining and assembly.

[0003] In related technologies, a step-by-step drilling process is typically used to further improve the accuracy of the assembled holes. This involves drilling holes in each individual component first, and then stacking and assembling the drilled components together.

[0004] However, the step-by-step drilling method can lead to misalignment of the drilled holes due to accumulated errors, making it difficult for the combined holes formed after stacking to meet the assembly accuracy requirements. Summary of the Invention

[0005] This disclosure provides a method for machining combined holes, which can improve the machining accuracy of combined holes. The technical solution is as follows: This disclosure provides a method for processing combined holes, the method comprising: processing interconnected bottom holes in each of a plurality of parts, the axial direction of the bottom holes being the same as the stacking direction; processing the bottom holes of all parts in a Nth set to form pin holes; and processing one end of the part closest to the Nth set in the (N+1)th set adjacent to the Nth set to form a countersunk hole in the part closest to the Nth set in the (N+1)th set, the inner diameter of the end of the countersunk hole facing the pin hole being coaxial with and having the same inner diameter as the pin hole; removing the parts in the Nth set; and processing the bottom holes of all parts in the (N+1)th set according to the countersunk hole to form pin holes, wherein N is a natural number starting from 1, and the first set is the set of parts located on the outermost side in the stacking direction.

[0006] In another implementation of this disclosure, the difference in inner diameter between the pin hole and the bottom hole is 0.1-0.2 mm.

[0007] In another implementation of this disclosure, the depth of the section in the countersunk hole that has the same inner diameter as the pin hole is greater than 1 / 10 of the depth of the countersunk hole.

[0008] In another implementation of this disclosure, the method further includes: before machining interconnected bottom holes in each of the plurality of parts, stacking and assembling the plurality of parts together using a fixture, wherein the fixture is a G-type clamp, the fixture including a frame and a screw, one side of the frame having jaws for clamping the stacked workpieces, the jaws being located between the top and bottom of the frame, one end of the screw being located in the jaws, the middle portion of the screw being connected to the top of the frame, and the other end of the screw being located outside the frame. Bottom holes are machined in each of the parts, penetrating the opposite sides of each part.

[0009] In another implementation of this disclosure, when the plurality of parts are stacked and assembled together, the gap between two adjacent parts is no greater than 0.02 mm.

[0010] In another implementation of this disclosure, the step of machining interconnected bottom holes in each of the plurality of parts includes: drilling holes at target positions of each of the parts along the stacking direction of the stacked workpiece while the fixture is holding the plurality of parts; rotating the stacked workpiece to drill holes at other positions of each of the parts, such that a plurality of bottom holes are spaced apart in the circumferential direction of each of the parts.

[0011] In another implementation of this disclosure, before rotating the stacked workpiece, the method further includes: after obtaining the bottom hole at the target position, removing the fixture and fixing each of the parts through the bottom hole at the target position.

[0012] In another implementation of this disclosure, two adjacent parts among the plurality of parts include a first part and a second part, the first part having a positioning ring groove; the processing method further includes: placing the second part in the positioning ring groove, and arranging a plurality of shims arranged circumferentially in the positioning ring groove, such that each shim is clamped between the second part and the first part.

[0013] In another implementation of this disclosure, the plurality of gaskets are arranged symmetrically in pairs along the axis of the positioning ring groove.

[0014] In another implementation of this disclosure, there are multiple bottom holes, which are distributed at intervals along the circumference of the stacked workpieces; when processing the bottom holes of all parts in the Nth set to form pin holes, the process includes: locking multiple parts together through a portion of the bottom holes of each part in the Nth set and the Mth set, and processing the unlocked bottom holes of all parts in the Nth set, where M is a natural number greater than N.

[0015] The beneficial effects of the technical solutions provided in this disclosure are: When machining combined holes on stacked workpieces using the machining method provided in this disclosure, the method first machines interconnected bottom holes in each part, then machines the bottom holes of all parts in the Nth set to form pin holes, and machines one end of the part closest to the Nth set in the (N+1)th set to form a countersunk hole in the part closest to the Nth set in the (N+1)th set. Then, the parts of the Nth set are removed, and the bottom holes of all parts in the (N+1)th set are machined based on the countersunk holes in the parts. This process allows for machining the bottom holes of each set of parts according to the position of the countersunk holes, until all parts have pin holes. Therefore, when machining pin holes on parts of different sets (i.e., parts of different materials), this disclosure can use the pre-machined countersunk holes in each set as a reference for correction and guidance, machining the bottom holes of each set of parts, thereby ensuring that the pin holes of all parts are coaxial and of equal diameter, greatly improving the accuracy of the combined holes. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a stacked workpiece provided in an embodiment of the present disclosure; Figure 2 A flowchart illustrating a method for machining a combination hole according to an embodiment of this disclosure; Figure 3 A flowchart illustrating another method for processing combined holes provided in an embodiment of this disclosure; Figure 4 This is a schematic diagram of the structure of the fixture provided in the embodiments of this disclosure; Figure 5 A schematic diagram showing the machining of bottom holes for each part in a stacked workpiece; Figure 6 This is a schematic diagram of machining a pin hole in a part of a stacked workpiece. Figure 7 This is a schematic diagram of machining pin holes for parts two and three in a stacked workpiece. Figure 1 ; Figure 8 This is a schematic diagram of machining pin holes for parts two and three in a stacked workpiece. Figure 2 .

[0018] The symbols in the diagram represent the following meanings: 101. Part 1; 1010. Inner hole; 102. Part Two; 1021. First Positioning Ring Groove; 1022. Second Positioning Ring Groove; 103. Part Three; 200. Fixture; 201. Frame; 202. Screw; 300, Bottom hole; 301, Pin hole; 302, Countersunk hole. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0020] In related technologies, stacked workpieces include multiple parts stacked sequentially in a stacking direction. These multiple parts are divided into multiple part sets, each part set including one part, or multiple parts made of the same material, with the parts in adjacent part sets being made of different materials. Adjacent part sets are two part sets that are adjacent to each other along the stacking direction of the multiple parts.

[0021] Figure 1 This is a schematic diagram of a stacked workpiece provided in an embodiment of the present disclosure, specifically a half-sectional view of the stacked workpiece, showing only half of the structure of the stacked workpiece. See also... Figure 1 This type of stacked workpiece is formed by stacking three parts together.

[0022] The stacked workpieces include part 101, part 202, and part 303. Part 101 is a ring-shaped part with a threaded inner hole 1010. Part 202 is a cylindrical part with openings at both ends and a hollow interior. The first end of part 202 has a first locating ring groove 1021. The end face of the first end of part 202 has a second locating ring groove 1022. The first locating ring groove 1021 and the second locating ring groove 1022 are located on opposite sides of the first end of part 202. Part 103 is located within the first locating ring groove 1021.

[0023] Part 3 103 is also a cylindrical part with openings at both ends and a hollow interior. The first end of Part 3 103 is located in the second positioning ring groove 1022 of Part 2 102. The inner hole of Part 1 101, the interior of Part 2 102, and the interior of Part 3 103 are interconnected.

[0024] Part 101 is an aluminum structural component. Parts 202 and 303 are both stainless steel structural components. Therefore, when machining a through-hole at the overlapping position of Parts 101, 202, and 303, directly using a reamer will result in significant deviations in the hole diameter on different parts due to differences in the hardness of the different materials, making it difficult to meet the requirements for the machined pin hole.

[0025] In this embodiment of the disclosure, it is necessary to specify the overlapping position of part 101, part 202, and part 303 ( Figure 1 Multiple pin holes are machined circumferentially at position a) to simultaneously pass through parts 101, 102, and 103. This allows parts 101, 102, and 103 to be locked together via the machined pin holes.

[0026] For example, the thickness at the overlapping position of part 101 and part 202 is 4mm. Therefore, directly machining the pin hole with a reamer will result in the hole diameter of part 1 being too large and exceeding the tolerance.

[0027] In this embodiment, the inner diameter of the machined pin hole in each part is D.

[0028] This disclosure provides a method for machining combined holes in a stacked workpiece, such as... Figure 2 As shown, the processing method includes: S201: In each of multiple parts, interconnected bottom holes are machined, with the axial direction of the bottom holes being the same as the stacking direction.

[0029] Among them, the multiple parts in step S201 can be Figure 1 The three parts shown could also be other types of stacked workpieces. For example, four parts corresponding to four different materials.

[0030] In this embodiment of the disclosure, the superimposed workpiece is Figure 1 The superimposed type of workpiece is shown.

[0031] S202: Machining the bottom holes of all parts in set N to form pin holes, and machining one end of the part in set N+1 that is closest to set N to form a countersunk hole in set N+1 that is closest to set N.

[0032] The inner diameter of the end of the countersunk hole facing the pin hole is coaxial with and has the same inner diameter as the pin hole.

[0033] S203: Remove parts from set N.

[0034] S204: Machine the bottom holes of all parts in set N+1 according to the countersunk holes to form pin holes.

[0035] Where N is a natural number starting from 1, and the first set is the set of parts located on the outermost side in the stacking direction.

[0036] When machining combined holes on stacked workpieces using the processing method provided in this disclosure, the method first machines interconnected bottom holes in each part, then machines the bottom holes of all parts in the Nth set to form pin holes, and then machines one end of the part closest to the Nth set in the (N+1)th set to form a countersunk hole in the part closest to the Nth set in the (N+1)th set. Then, the parts of the Nth set are removed, and the bottom holes of all parts in the (N+1)th set are machined based on the countersunk holes in the parts of the N+1th set. This allows for machining the bottom holes of the parts in each set according to the position of the countersunk holes, until all parts have pin holes. Therefore, when machining pin holes on parts of different sets (i.e., parts of different materials), this disclosure can use the pre-machined countersunk holes in each set as a reference for correction and guidance, machining the bottom holes of the parts in each set, thereby ensuring that the pin holes of all parts are coaxial and of equal diameter, greatly improving the accuracy of the combined holes.

[0037] The specific processing procedure can be as follows: First, machine interconnected bottom holes in each part. Then, machine the bottom holes of all parts in set 1 to form pin holes. Next, machine one end of the part in set 2 closest to set 1 to form a countersunk hole. Then, remove the parts in set 1. Using the countersunk holes in the parts in set 2 as a reference, machine the bottom holes of all parts in set 2. Simultaneously, machine the bottom holes of the parts in set 3 adjacent to set 2 to form countersunk holes. Then, remove the parts in set 2. Next, using the countersunk holes of the parts in set 3 as a reference, continue machining the bottom holes of all parts in set 3 to obtain pin holes. Simultaneously, machine countersunk holes in the parts in set 4 adjacent to set 3. Repeat the above steps until all parts have pin holes.

[0038] On the other hand, embodiments of this disclosure also provide another method for processing combined holes in stacked workpieces, such as... Figure 3 As shown, the processing method includes: S301: Stack multiple parts together in sequence.

[0039] To facilitate the installation of two adjacent parts, the lower part has a locating ring groove. The other part is located in the locating ring groove.

[0040] This makes it easier to position the parts through the positioning ring groove 10.

[0041] For example, two adjacent parts include a first part and a second part. The first part has a positioning ring groove.

[0042] The arrangement of the positioning ring grooves facilitates the placement of the second part on the first part, improving the positioning accuracy and installation efficiency of both.

[0043] In other words, when stacking the various parts together, for any two adjacent parts, the second part can be placed in the positioning ring groove of the first part.

[0044] In addition, in order to further position the parts circumferentially and make the bottom holes of the machined parts coaxial, multiple shims arranged circumferentially in the positioning ring groove can be arranged together, so that each shim is clamped between the second part and the first part.

[0045] By arranging the shims, the first part and the second part can be arranged coaxially, thereby enabling the corresponding bottom holes in the first part and the second part to be coaxial.

[0046] In this embodiment, multiple gaskets are arranged symmetrically in pairs along the axis of the positioning ring groove 10.

[0047] The gasket is a 0.1mm thick copper gasket. The thickness of the gasket is the length of the gasket along the radial direction of part one.

[0048] During actual assembly, at the mating point of the first and second parts, 0.1mm thick copper shims are symmetrically used in four places to tightly seal the gap between the outer circle of the second part and the groove wall of the positioning ring groove.

[0049] In other examples, other parts may not need to be installed in the same way as described above. The key is to ensure that all parts are aligned sequentially.

[0050] In this embodiment, multiple parts are clamped together using a fixture.

[0051] In other examples, other methods can be used, such as pressure plates. The key is to stack multiple parts together without affecting subsequent drilling operations.

[0052] Figure 4 This is a schematic diagram of the structure of the fixture provided in the embodiments of this disclosure, combined with... Figure 4In this embodiment, the clamp 200 can be a G-type clamp. The clamp 200 includes a frame 201 and a screw 202. One side of the frame 201 has jaws located between the top and bottom of the frame 201. One end of the screw 202 is located in the jaws, and the middle part of the screw 202 is connected to the top of the frame 201. The other end of the screw 202 is located outside the frame 201.

[0053] By controlling the rotation of the screw 202, the depth to which the screw 202 extends into the jaws can be controlled, thereby controlling the size of the opening between the bottom of the frame 201 and the end of the screw 202, thus changing the clamping space of the clamp 200.

[0054] When multiple parts are stacked together using the above-mentioned clamp 200, the stacking position of the multiple parts can be set in the defined opening between the bottom of the screw 202 and the end of the screw 202.

[0055] Then, by adjusting the screw 202, multiple parts can be clamped together through the bottom of the frame 201 and the screw 202.

[0056] In other examples, clamp 200 may also be other structures, such as clamps formed by two movable clamps.

[0057] In this embodiment, in order to improve the stability of the stacked parts, four G-type clamps evenly distributed along the circumference are used to fix the parts.

[0058] When multiple parts are stacked and assembled together, the gap between two adjacent parts shall not exceed 0.02mm.

[0059] After multiple parts are clamped together, a feeler gauge can be used to check the axial clearance S between two adjacent parts (see...). Figure 4 S)≤0.02, and at the same time check that the coaxiality between the outer circle and the inner wall of the positioning ring groove of the adjacent parts is ≤0.05.

[0060] S302: Multiple bottom holes are machined through each part.

[0061] Optionally, step S302 may include the following steps: 3021: Drill holes at the target positions of each part along the stacking direction of the stacked workpiece.

[0062] 3022: Rotate and stack workpieces, drill holes in other positions of each part, so that multiple bottom holes are arranged at intervals in the circumferential direction of each part.

[0063] The above method allows multiple pilot holes to be drilled in the circumferential direction for each part. The pilot holes in two adjacent parts correspond to each other and are interconnected.

[0064] To solve the interference problem caused by the fixture when machining the bottom hole, in step 3022, before machining, when a portion of the bottom hole is obtained, the fixture can be removed first, and multiple parts can be fixed together through the drilled portion of the bottom hole. Then, the stacked workpiece is rotated, and each part is machined, so that the multiple bottom holes in each part are arranged along the circumference of the part.

[0065] For example, when it is necessary to machine 36 bottom holes in each part, four, six or eight bottom holes can be machined first, and then fasteners such as bolt pairs can be installed in the four, six or eight bottom holes to make the parts stacked and fixed together. Then the fixture 200 can be removed, and the stacked workpiece can be rotated to continue to process other positions of each part so that each part has 36 bottom holes evenly arranged in the circumference.

[0066] In this embodiment, a reamer is used to drill the bottom hole.

[0067] S303: Lock multiple parts together by using partial bottom holes of each part in set N and set M, and process the unlocked bottom holes of all parts in set N.

[0068] Where M is a natural number greater than N.

[0069] This allows the pre-machined bottom holes to be used to stack the various parts together.

[0070] For example, when N is 1, the corresponding M is a natural number starting from 2. When machining the bottom holes of parts in set 1, the bottom holes of each part in all sets can be partially locked together to form a single unit. Then, the unlocked bottom holes of the parts in set 1 can be machined. When N is 2, the corresponding M is a natural number starting from 3, and so on.

[0071] S304: Machining the unlocked bottom holes of all parts in set N to form pin holes, and machining one end of the part in set N+1 that is closest to set N to form a countersunk hole in set N+1 that is closest to set N.

[0072] N is a natural number starting from 1. The first set is the set of parts located on the outermost side in the stacking direction.

[0073] The inner diameter of the countersunk hole facing the pin hole is coaxial with and has the same inner diameter as the pin hole.

[0074] The pin hole is coaxial with the pilot hole, and its inner diameter is larger than that of the pilot hole. In other words, the pin hole is obtained by further enlarging the pilot hole.

[0075] The difference in inner diameter between the pin hole and the bottom hole is 0.1-0.2 mm.

[0076] When machining pin holes, machining can be performed separately depending on the different sets of parts (i.e., different materials). That is, during machining, only all parts of the same material stacked together are machined at a time. Simultaneously, to ensure that the pin holes to be machined in parts of other materials are coaxial with the pin holes to be machined, when machining the pin holes in the part to be machined, one end of the bottom hole of another part in a neighboring set can be machined simultaneously to form a countersunk hole.

[0077] for example, Figure 1 The three parts shown are arranged axially. The top part is made of aluminum, while the other two are steel structural components. When... Figure 1 When machining pin holes for the various parts shown, pin holes can be obtained by machining the bottom hole in the top aluminum part, while the top of the bottom hole in the middle part is machined to form a countersunk hole.

[0078] The purpose of countersunk holes is to serve as a reference for correction and guidance when machining pin holes in subsequent parts.

[0079] In this embodiment, when machining pin holes and countersunk holes on the parts, an end mill can be used to machine the parts.

[0080] In addition, in order to improve the accuracy of the countersunk hole as a calibration and guide, the depth of the section in the countersunk hole with the same inner diameter as the pin hole is greater than 1 / 10 of the depth of the countersunk hole.

[0081] For example, if the depth of the bottom hole of the part containing the countersunk hole is 4.5mm, the depth of the section of the countersunk hole with the same inner diameter as the pin hole can be 0.5mm.

[0082] It should be noted that when all parts in the same assembly being machined are relatively thick (e.g., greater than 50mm) and the material has high hardness, when machining the pin hole, a boring bar can be used to first enlarge the pilot hole to an inner diameter of D1, and then a reamer can be used to further enlarge the pilot hole until the pin hole is obtained. The inner diameter of the pin hole is D, and the difference between D1 and D must be between 0.1 and 0.2mm.

[0083] For example, D-D1=0.15mm.

[0084] S305: Remove parts from set N.

[0085] Once all the pin holes in the parts of set N have been machined, the parts in set N can be removed, and the previously machined countersunk holes can be located at one end of the remaining parts.

[0086] S306: Machine the bottom holes of all parts in set N+1 according to the countersunk hole to form pin holes.

[0087] When machining the bottom hole of the target part based on the countersunk hole, step S304 can be followed.

[0088] It should be noted that when machining the pin hole, the parts can be locked by adjusting the position of the bolt and nut in different bottom holes.

[0089] S307: Repeat steps S304-S306 until all parts have been machined with pin holes to obtain the combined hole.

[0090] Once all the pin holes of the parts have been machined, it means that the axes of the various parts will be aligned to form a combination hole, through which multiple parts can be assembled together.

[0091] The following specific examples further illustrate the above processing methods: For example, when it is necessary to Figure 1 When machining the combined holes in the stacked parts shown, the following process can be followed: First, according to Figure 4 The three parts are assembled and locked together in this way.

[0092] During assembly, at the circumferential mating point of part 101 and part 202, 0.1mm thick copper shims can be used to symmetrically fill the gap R between the outer circle of part 101 and the locating ring groove of part 202 in four places.

[0093] Then, use four G-type clamps 200 evenly distributed around the circumference to fix the three parts. Then, use a feeler gauge to check that the axial clearance S between two adjacent parts is ≤0.02, and check that the coaxiality between the outer circle of part 101 and part 202 is ≤0.05, and the coaxiality between part 202 and part 303 is ≤0.05.

[0094] Figure 5 This is a schematic diagram showing the machining of the bottom holes for each part in a stacked workpiece, combined with... Figure 5 According to the required dimensions, multiple 300mm bottom holes were drilled in each of the three parts.

[0095] The inner diameter of the 300mm bottom hole is D-0.05mm. D is the inner diameter of the pin hole.

[0096] To prevent interference, the workpiece can be secured with bolts and nuts through the pre-drilled pilot hole, and the G-clamp can be removed before drilling pilot holes in other locations.

[0097] Figure 6 This is a schematic diagram of a part with a machined pin hole in a stacked workpiece. Figure 6Next, a pin hole 301 with an inner diameter of D is milled in the bottom hole of part 101 using an end mill, and a countersunk hole 302 is milled at the top of the bottom hole of part 2102. That is, holes with a height of h and an inner diameter of D are directly milled in parts 1 and 2. h is greater than the thickness of part 1.

[0098] When milling the pin hole in part 101, the three parts can be locked together by adjusting the position of the bolt and nut.

[0099] Figure 7 This is a schematic diagram of machining pin holes for parts two and three in a stacked workpiece. Figure 1 , combined Figure 7 Next, after all the pin holes in part 101 have been machined, remove part 101. Lock parts 2 and 3 together. Using the countersunk hole 302 of part 2 as a reference for correction and guidance, machine the bottom holes of parts 202 and 303 so that the inner diameter of the bottom holes is bored to a dimension of D-0.15.

[0100] Figure 8 This is a schematic diagram of machining pin holes for parts two and three in a stacked workpiece. Figure 2 , combined Figure 8 Next, the bottom holes of parts two and three are machined using a reamer to obtain pin holes with an inner diameter of D.

[0101] By combining and then disassembling the parts, the problem of low precision in the combined holes caused by the large hardness difference between different materials in each part can be solved.

[0102] The above are merely optional embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A method for machining combined holes in a stacked workpiece, characterized in that, The stacked workpiece includes multiple parts stacked sequentially in a stacking direction. These multiple parts are divided into multiple part sets, each part set including one of the parts, or multiple parts made of the same material. The parts in two adjacent part sets are made of different materials. The processing method includes: Interconnected bottom holes are machined in each of the plurality of parts, the axial direction of the bottom holes being the same as the stacking direction; The bottom holes of all parts in the Nth set are machined to form pin holes, and one end of the part in the N+1th set that is closest to the Nth set is machined to form a countersunk hole in the part in the N+1th set that is closest to the Nth set. The inner diameter of the end of the countersunk hole facing the pin hole is coaxial with and has the same inner diameter as the pin hole. Remove the parts from the Nth set; The bottom holes of all parts in the (N+1)th set are machined according to the countersunk holes to form pin holes, where N is a natural number starting from 1, and the first set is the set of parts located on the outermost side in the stacking direction.

2. The method for machining the combined hole according to claim 1, characterized in that, The difference in inner diameter between the pin hole and the bottom hole is 0.1-0.2 mm.

3. The method for machining the combined hole according to claim 1, characterized in that, The depth of the section of the countersunk hole with the same inner diameter as the pin hole is greater than 1 / 10 of the depth of the countersunk hole.

4. The method for machining the combined hole according to claim 1, characterized in that, The method further includes: clamping the stacked parts together with a jig before machining interconnected bottom holes in each of the plurality of parts; The clamp is a G-type clamp. The clamp (200) includes a frame (201) and a screw (202). One side of the frame (201) has jaws for clamping the stacked workpieces. One end of the screw (202) is located in the jaws. The middle part of the screw (202) is connected to the top of the frame (201). The other end of the screw (202) is located outside the frame (201).

5. The method for machining the combined hole according to claim 4, characterized in that, When the multiple parts are stacked and assembled together, the gap between two adjacent parts shall not be greater than 0.02 mm.

6. The method for machining the combined hole according to claim 4, characterized in that, The step of machining interconnected bottom holes in each of the plurality of parts includes: While the fixture is holding the plurality of parts, holes are drilled at the target positions of each of the parts along the stacking direction of the stacked workpieces; Rotate the stacked workpiece and drill holes in other positions of each part, so that multiple bottom holes are arranged at intervals in the circumferential direction of each part.

7. The method for machining the combined hole according to claim 6, characterized in that, Before rotating the stacked workpiece, the method further includes: After obtaining the bottom hole at the target position, remove the clamp and fix each part through the bottom hole at the target position.

8. The method for machining the combined hole according to claim 5, characterized in that, Among the plurality of parts, two adjacent parts include a first part and a second part, wherein the first part has a positioning ring groove; The processing method further includes: The second part is placed in the positioning ring groove, and a plurality of shims are arranged in the positioning ring groove along the circumference of the positioning ring groove, such that each shim is clamped between the second part and the first part.

9. The method for machining the combined hole according to claim 8, characterized in that, The plurality of gaskets are arranged symmetrically in pairs along the axis of the positioning ring groove.

10. A method for machining a combined hole according to any one of claims 1-9, characterized in that, The bottom holes are multiple, and the multiple bottom holes are distributed at intervals along the circumference of the stacked workpiece; When machining the bottom holes of all parts in the Nth set to form pin holes, the process includes: Multiple parts are locked together by partially said bottom holes of each part in the Nth set and the Mth set, and the unclamped bottom holes of all parts in the Nth set are machined, where M is a natural number greater than N.

Images