A method and device for clamping thin-walled multi-cavity parts

Abstract

The present invention discloses a method and device for clamping thin-walled multi-cavity parts. The method provides adsorption force, determines the size of the adsorption force according to the characteristics of the thin-walled multi-cavity parts, calculates the adsorption area according to the milling force of the CNC milling machine and the clamping adsorption force, and then calculates the number of adsorption holes required to maintain the clamping force. A plurality of adsorption holes provide suction to adsorb and clamp the parts to be clamped. The clamping device is suitable for the clamping method. The clamping device includes an upper mold and a lower mold. The top of the upper mold is an adsorption end. The shape of the adsorption end is adapted to the part cavity. A plurality of adsorption holes are arranged on the adsorption end. The lower mold is provided with an exhaust hole and a breathable cavity. The exhaust hole, the adsorption hole and the breathable cavity are connected. The structure of the present invention is relatively simple, the clamping operation is convenient, and the clamping method is suitable for a variety of thin-walled multi-cavity parts of different structural forms. It has good versatility and uniform force, and can provide guarantee for subsequent precision processing.

Description

Technical Field

[0001] The invention relates to the technical field of precision machining and manufacturing, and in particular to a method and a device for clamping thin-wall multi-cavity parts. Background Art

[0002] For high-precision machined parts used in aerospace products, such as crack waveguide antenna parts, they usually have the following characteristics: Due to the lightweight requirements of aerospace products, aerospace parts are generally made of lightweight aluminum alloy materials, and the weight needs to be reduced to the greatest extent while meeting the conditions of use. The parts are usually thin-walled and multi-cavity. For example, some large crack waveguide antennas have many walls of about 0.8mm-1mm, and there are a large number of cavities on both sides, with the number reaching tens of thousands. Based on the above characteristics, the clamping problem is a difficult point in the processing of such parts. Compared with steel, aluminum alloy has weak rigidity, and due to the thin wall and multi-cavity on both sides, traditional clamping methods such as vises and pressure plate overlap cannot meet the processing requirements of thin-walled multi-cavity parts; the usual solution is to design special fixtures for clamping according to the characteristics of different thin-walled multi-cavity parts. Patents CN109202140B, CN211804921U, CN110774030A, CN111299515A and other patents disclose methods for processing waveguide precision flanges and a series of thin-walled parts, all of which are designed with special fixtures for clamping. It can be seen that all fixtures are designed according to the characteristics of their own parts, the methods have a narrow application range, and the cost of use is high.

[0003] In view of the above-mentioned defects, the inventors of the present invention finally obtained the present invention after a long period of research and practice. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problems that the fixture is designed according to the characteristics of thin-walled multi-cavity parts, the method has a narrow application range and a high cost of use. A method and device for clamping thin-walled multi-cavity parts are provided. For thin-walled multi-cavity parts with high processing accuracy requirements, a set of universal clamping device methods are provided, which can realize high-quality processing of thin-walled multi-cavity high-precision parts.

[0005] A method for clamping a thin-walled multi-cavity part, the method comprising the following steps:

[0006] S1: Determine the clamping adsorption force according to the characteristics of thin-walled multi-cavity parts;

[0007] Clamping adsorption force formula:

[0008] F′=P·A

[0009] Among them, F' represents the clamping adsorption force; P represents the internal vacuum degree; A represents the adsorption area that maintains the clamping force;

[0010] S2: Calculate the adsorption area to maintain the clamping force based on the milling force of the CNC milling machine and the clamping adsorption force;

[0011] The calculation formula of milling force of CNC milling machine is:

[0012]

[0013] Where F represents the milling force; c F is the milling force coefficient; z is the number of milling cutter teeth; d 0 Indicates the diameter of the milling cutter; k F Indicates the correction factor; a p Indicates the milling depth, that is, the size of the cut layer measured parallel to the milling cutter axis; a e Indicates the milling width, that is, the size of the cut layer measured perpendicular to the milling cutter axis; a f Indicates the feed per tooth;

[0014] When the milling force and the adsorption force are balanced, the relationship between the milling force and the clamping adsorption force of the CNC milling machine is: F = μF′;

[0015] The formula for the adsorption area to maintain the clamping force is:

[0016]

[0017] Among them, A represents the adsorption area for maintaining the clamping force; K represents the safety factor; μ represents the friction coefficient;

[0018] S3: The number of adsorption holes required is calculated according to the adsorption area for maintaining the clamping force and the adsorption area of ​​a single adsorption hole, so that the adsorption force is evenly distributed on several adsorption holes, and the suction force of several adsorption holes is used to realize the adsorption clamping of thin-walled multi-cavity parts.

[0019] Furthermore, the specific contents of step S3 include:

[0020] S31: Calculate the number of adsorption holes required in the adsorption end according to the adsorption area to maintain the clamping force:

[0021]

[0022] Where n represents the number of adsorption holes; S represents the area of ​​a single adsorption hole;

[0023] S32: According to the calculated number of adsorption holes, a plurality of adsorption holes are evenly arranged on the adsorption end.

[0024] A clamping device for clamping using the above-mentioned thin-walled multi-cavity part clamping method, the clamping device includes an upper mold and a lower mold, the top of the upper mold is an adsorption end, and the adsorption end is adapted to the part to be clamped; the adsorption end is provided with a plurality of adsorption holes; the top of the lower mold is sealed and connected to the bottom of the upper mold, and the lower mold is provided with an exhaust hole and a breathable cavity, and the breathable cavity is connected to the exhaust hole; the plurality of adsorption holes on the upper mold are connected to the breathable cavity on the lower mold.

[0025] Furthermore, the connection between the upper mold and the lower mold is welded and sealed.

[0026] Furthermore, a sealing groove is provided on the outer side of the air permeable cavity of the lower mold, an elastic sealing ring is provided in the sealing groove, the sealing ring protrudes from the top surface of the air permeable cavity, and the bottom of the upper mold is sealed and connected to the top of the lower mold through the sealing ring.

[0027] Furthermore, the sealing ring protrudes upward along the top surface of the air permeable cavity by 0.3 mm to 0.5 mm.

[0028] Furthermore, the adsorption end includes a protrusion and a recessed cavity that are compatible with the structure of the part to be clamped, the protrusion is designed with a negative tolerance, and the height value of the protrusion is 0.2mm higher than its standard value; the recessed cavity is designed with a positive tolerance, and the height value of the recessed cavity 2 is 0.2mm lower than its standard height.

[0029] Furthermore, the raised portion of the adsorption end matches the structure of the cavity of the part to be clamped, and the recessed cavity of the adsorption end matches the structure of the thin wall of the part to be clamped.

[0030] Furthermore, the plurality of adsorption holes are evenly arranged on the raised portion of the adsorption end.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] 1. In order to achieve the adsorption effect, the adsorption area for maintaining the clamping force needs to be determined in the adsorption clamping method of the present invention, and the number of adsorption holes required is calculated according to the adsorption area of ​​each adsorption hole. The adsorption force is evenly distributed on a number of adsorption holes, and the adsorption clamping of the parts to be clamped is completed by using the suction force of the adsorption holes. The method is simple to operate and has uniform force, and can provide guarantee for the subsequent precision processing of the parts to be clamped;

[0033] 2. The present invention determines the structural form of the clamping device, and the processing method thereof is simple. All parts of the clamping device can be directly manufactured by numerical control processing, which reduces the manufacturing difficulty and improves the processing accuracy;

[0034] 3. The adsorption clamping method of the present invention can be applied to a variety of thin-walled multi-cavity parts with different structural forms, without being affected by size. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a front view schematic diagram of the first thin-walled multi-cavity part;

[0036] Figure 2 It is a schematic diagram of the back side of the first thin-walled multi-cavity part;

[0037] Figure 3 It is a structural schematic diagram of the first connection method between the upper mold and the lower mold;

[0038] Figure 4 It is a structural schematic diagram of the second connection method between the upper mold and the lower mold;

[0039] Figure 5 It is a schematic diagram of the structure of the second type of thin-walled multi-cavity part;

[0040] Figure 6 It is a schematic diagram of the clamping plane of multiple thin-walled multi-cavity parts.

[0041] The numbers in the figure represent:

[0042] 11-thin wall; 12-cavity; 13-through cavity; 14-convex part; 31-upper mold; 311-adsorption hole; 32-lower mold; 321-air permeable cavity; 322-exhaust hole; 323-side wall; 4-sealing groove; 51-boss; 52-partition; 61-first overlap; 62-second overlap DETAILED DESCRIPTION

[0043] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the protection scope of the present invention.

[0044] A method for clamping a thin-walled multi-cavity part, the method comprising the following steps:

[0045] S1: Determine the clamping adsorption force according to the characteristics of thin-walled multi-cavity parts;

[0046] Clamping adsorption force formula:

[0047] F′=P·A

[0048] Among them, F' represents the clamping adsorption force; P represents the internal vacuum degree; A represents the adsorption area that maintains the clamping force;

[0049] S2: Calculate the adsorption area to maintain the clamping force based on the milling force of the CNC milling machine and the clamping adsorption force;

[0050] The calculation formula of milling force of CNC milling machine is:

[0051]

[0052] Where, F represents the milling force; c F is the milling force coefficient; z is the number of milling cutter teeth; d 0 Indicates the diameter of the milling cutter; k F Indicates the correction factor; a p Indicates the milling depth, that is, the size of the cut layer measured parallel to the milling cutter axis; a e Indicates the milling width, that is, the size of the cut layer measured perpendicular to the milling cutter axis; a f Indicates the feed per tooth;

[0053] When the milling force and the adsorption force are balanced, the relationship between the milling force and the clamping adsorption force of the CNC milling machine is: F = μF′;

[0054] The formula for the adsorption area to maintain the clamping force is:

[0055]

[0056] Among them, A represents the adsorption area for maintaining the clamping force; K represents the safety factor; μ represents the friction coefficient;

[0057] S3: The number of adsorption holes required is calculated according to the adsorption area for maintaining the clamping force and the adsorption area of ​​a single adsorption hole, so that the adsorption force is evenly distributed on several adsorption holes, and the suction force of several adsorption holes is used to realize the adsorption clamping of thin-walled multi-cavity parts.

[0058] Example 1

[0059] The processing method provided by the present invention is mainly aimed at high-precision thin-walled multi-cavity parts. The structural schematic diagram of the first thin-walled multi-cavity part targeted by this embodiment is shown in the attached figure. Figure 1As shown in the figure, this type of thin-walled multi-cavity parts mainly use aluminum alloy, magnesium alloy and other raw materials that are obviously "softer" in strength and stiffness than steel. The structure is a large flat thin plate structure with large length and width. The length and width of a single layer of a millimeter wave antenna is 800mm, and the thickness is small, usually less than 10mm. The characteristics are mainly concentrated on the upper and lower large surfaces, mainly including thin walls 11, which are mostly about 0.8mm-1mm. A cavity 12 is formed between the thin walls 11, and the cavity 12 also includes a through cavity 13 and a convex portion 14. The upper and lower surfaces of the thin-walled multi-cavity parts have similar structural characteristics, as shown in the figure. Figure 2 As shown, attached Figure 2 For attachment Figure 1 The first example of the reverse feature of a thin-walled multi-cavity part has structural features similar to those of the attached Figure 1 is basically the same as shown in Figure 2 There is no convex portion 14 feature in the middle.

[0060] For thin-walled multi-cavity parts with such materials and characteristics, it is difficult to clamp them with a pressure plate due to their thin walls and lack of effective clamping edges. At the same time, when the thin-walled multi-cavity parts are very large, the pressure plate can only be used on the periphery, and the middle of the thin-walled multi-cavity parts cannot be clamped, which affects the processing accuracy of the thin-walled multi-cavity parts. On the other hand, improper clamping of the pressure plate will also damage the surface of the thin-walled multi-cavity parts. Therefore, the processing method designed in the present invention proposes a design of a clamping device. By analyzing the structural characteristics of the above-mentioned thin-walled multi-cavity parts, the clamping device type is selected as a suction clamp. Attached clamping device; The traditional adsorption clamping device usually includes an adsorption end, which has an adsorption groove. All the adsorption grooves are connected and communicate with the outside world through an exhaust hole. The thin-walled multi-cavity parts are placed on the adsorption end and sealing measures are taken, such as using a sealing ring for sealing. The air in the adsorption groove of the adsorption end is extracted through a vacuum equipment, so that the thin-walled multi-cavity parts are adsorbed on the clamping device using atmospheric pressure. This clamping method has no size limit for thin-walled multi-cavity parts. After clamping, the entire large surface of the thin-walled multi-cavity parts can be evenly stressed, thereby improving the processing accuracy.

[0061] For the above-mentioned clamping device, in order to facilitate processing, the design idea of ​​the adsorption end is to connect all the adsorption grooves and communicate with the outside world through an exhaust hole. However, if the adsorption grooves cannot be connected, it is usually replaced by drilling adsorption holes in the adsorption grooves and connecting the adsorption holes. At this time, if the area of ​​the clamping device is large and the distance between the adsorption holes is too far, it is necessary to use deep hole drilling equipment to drill horizontal holes to connect all the holes in the adsorption grooves together. However, deep hole drilling equipment processing has the disadvantages of being unable to detect the cutting state, difficult chip removal, and difficult to ensure processing accuracy. Therefore, the present invention determines the structural form of the adsorption clamping device according to the characteristics of thin-walled multi-cavity parts and the advantages and disadvantages of different processing strategies of the clamping device, as shown in the attached figure. Figure 3As shown:

[0062] The clamping device used in this embodiment adopts a split design, which is mainly composed of two parts:

[0063] The first part is the upper mold 31, the top of the upper mold 31 is the suction end, the suction end is the working end of the suction clamping device, and the thin-walled multi-cavity part to be processed is clamped on the suction end. Therefore, the shape of the suction end is designed in a shaping manner, that is, the shape of the suction end is designed to be a shape opposite to the shape of the cavity of the processed part, that is, the thin wall 11 of the thin-walled multi-cavity part is adapted to the concave cavity of the suction end, and the cavity 12 of the thin-walled multi-cavity part is adapted to the convex part of the suction end; as shown in the attached Figure 2 , 3 As shown, attached Figure 3 The shape of the suction end at the top of the middle and upper mold is the same as the shape of the suction end at the top of the middle and upper mold. Figure 2 The shape of the cavity of the thin-walled multi-cavity parts is opposite. Of course, the shape of the adsorption end can also be designed to be the same as the attachment. Figure 1 The cavity shape of the thin-walled multi-cavity parts is opposite. With this design method, the curved surface features of the clamping surface can be completely reversed in the adsorption end when the thin-walled multi-cavity parts are clamped, which is equivalent to converting the complex curved surface features into plane features for clamping, simplifying the difficulty of clamping.

[0064] It should also be noted that in order to facilitate clamping, when processing the adsorption end, attention should be paid to the negative tolerance design of the raised part side, that is, the raised part side is 0.2mm lower than its standard value, and the positive tolerance design of the recessed cavity side, that is, the recessed cavity side is 0.2mm higher than its standard value. At the same time, the flat part gives priority to ensuring that the parts with high precision requirements of thin-walled multi-cavity parts are in contact with the adsorption end, and the remaining positions leave negative tolerances.

[0065] Furthermore, more than two adsorption holes 311 are provided at the adsorption end; the adsorption holes 311 are uniformly provided on the raised portion of the adsorption end, that is, the surface matching the recessed cavity of the thin-walled multi-cavity part, and the adsorption holes 311 are through holes, directly connected to the bottom of the upper mold; in the working state, suction is generated in the adsorption holes 311, and the concave surface of the thin-walled multi-cavity part and the raised portion of the adsorption end are adsorbed together to prevent the thin-walled multi-cavity part from moving during the processing.

[0066] The second part is the lower mold 32, and the top of the lower mold 32 is connected to the bottom of the upper mold 31, wherein a breathable cavity 321 is opened at the top of the lower mold 32, and all the adsorption holes 311 set in the upper mold 31 are connected with the breathable cavity 321 at the top of the lower mold 32 through its bottom, and the breathable cavity 321 is connected to the side wall 323 of the lower mold through the exhaust hole 322.

[0067] Furthermore, the upper mold and the lower mold can be connected through a variety of schemes, and the principle of connection is: in the working state, the joint between the upper mold and the lower mold is kept to form a closed space;

[0068] For a possible solution, please refer to the attached Figure 3 : There are steps at the connection between the upper mold 31 and the lower mold 32, and the steps can be connected by a cover plate. The cover plate covers the step position at the connection between the upper mold 31 and the lower mold 32. The connection between the cover plate, the upper mold 31 and the lower mold 32 is welded and sealed by stir friction welding.

[0069] For another possible solution, please refer to the attached Figure 4 A sealing groove 4 is arranged outside the air permeable cavity 321 of the lower mold 32. When in use, a sealing ring is placed inside the sealing groove 4. The sealing ring is elastic and slightly protrudes from the top surface of the air permeable cavity by 0.3-0.5 mm. The bottom of the upper mold is fitted with the sealing ring for sealing.

[0070] The adsorption-type clamping device adopts the design and processing method described in this embodiment. All parts of the adsorption-type clamping device can be directly manufactured by CNC machining, which reduces the manufacturing difficulty and improves the machining accuracy.

[0071] Based on the above design, the working principle of the entire adsorption device is as follows: the clamping surface of the thin-walled multi-cavity part is placed on the adsorption end of the adsorption clamping device. Due to the use of the shaped structural design, the clamping surface of the part can fit on the adsorption end of the clamping device. Through the sealing of the sealing ring, the connection between the clamping surface of the part and the outside world is only the adsorption hole 311 set on the clamping device, and all the adsorption holes 311 are connected to the outside world only through the exhaust holes 323 on the side wall of the lower mold of the clamping device. At this time, the air in the exhaust holes 311 is sucked out by the external vacuum equipment, and the clamping surface of the part will be adsorbed on the clamping device due to the air pressure.

[0072] During the design process, in order to achieve the required adsorption effect, it is necessary to determine the total adsorption area and distribute it on the adsorption holes 311 at the adsorption end; the calculation method of the adsorption area is:

[0073] Determine the cutting force:

[0074] The processing equipment used is a CNC milling machine. According to the literature, the milling force of a CNC milling machine with relatively accurate calculation results is estimated using the formula:

[0075]

[0076] Where, F represents the milling force, unit is N; c F is the milling force coefficient; z is the number of milling cutter teeth; d 0Indicates the diameter of the milling cutter, in mm; k F Indicates the correction factor; a p Indicates the milling depth, which refers to the size of the cut layer measured parallel to the milling cutter axis, in mm; a e Indicates the milling width, which refers to the size of the cut layer measured perpendicular to the milling cutter axis, in mm; a f Indicates the feed per tooth.

[0077] The calculation formula for clamping adsorption force is:

[0078] F′=P·A (2)

[0079] Where F' represents the adsorption force, unit N; P represents the vacuum degree in the clamping device, unit KPa; A represents the effective adsorption area of ​​the clamping device, unit cm 2 .

[0080] Through force analysis, it can be seen that when the milling force and the adsorption force are balanced, it can be obtained:

[0081] F=μ·F′ (3)

[0082] Here, μ represents the friction coefficient.

[0083] Substituting formulas (1) and (2) into (3) and taking into account the safety factor, the adsorption area that maintains the workpiece clamping force is:

[0084]

[0085] Wherein, K represents the safety factor.

[0086] It can be seen from this that the minimum number of adsorption holes that should be set in the entire adsorption device is:

[0087]

[0088] Where n represents the number of adsorption holes; S represents the area of ​​a single adsorption hole, unit: mm 2 ;

[0089] Therefore, after determining the number of adsorption holes, the arrangement rule of the adsorption holes on the adsorption device of the present invention is determined:

[0090] For high-precision thin-walled multi-cavity parts, such as typical crack waveguide parts, the high-precision part is usually the waveguide cavity, that is, the cavity part of the thin-walled multi-cavity parts. Therefore, during processing, it is necessary to prioritize the accuracy of the cavity. The part cavity corresponds to the raised part of the clamping device. Therefore, the position of the adsorption hole is preferably set on the raised part corresponding to the part cavity. Due to the presence of radiation seams and other through-cavity features inside the waveguide cavity, the position of the adsorption hole should avoid such features. On this basis, try to ensure that the adsorption holes are evenly arranged on the clamping device to ensure that the thin-walled multi-cavity parts are evenly stressed during adsorption and achieve a good adsorption effect.

[0091] The above content provides a universal design principle and method for an adsorption-type clamping device for high-precision thin-walled multi-cavity parts. Under the guidance of the inventive method provided in this embodiment, an adsorption-type clamping device that meets the clamping requirements can be designed for high-precision thin-walled multi-cavity parts with different structural forms, thereby providing a guarantee for the subsequent precision processing of thin-walled multi-cavity parts.

[0092] Example 2

[0093] The high-precision thin-walled multi-cavity parts processing method described in this embodiment is the same as that described in Example 1, including the design ideas and structural forms of the fixture, the processing principles of precision machining, and the specific processing implementation process methods; the difference is that this embodiment is for the high-precision thin-walled multi-cavity parts processing method described in Example 1. Figure 1 The schematic diagram of the first thin-walled multi-cavity part structure shown provides other thin-walled multi-cavity part structures with different characteristic forms.

[0094] As attached Figure 5 The second thin-walled multi-cavity part shown in the figure has the same main features as the attached Figure 1 The structure is basically the same, the difference is that the Figure 4 The inner cavity boss 51 feature is higher than the partition 52 of the entire thin-walled multi-cavity part, and the multiple bosses 51 features can also have different heights; Figure 6 The schematic plan view of multiple thin-walled multi-cavity parts shown in FIG. Figure 1 , Attachment Figure 5 In the case of the same characteristics as the above, it also has a large array size structure or a modular array structure, and the modular array structure can be expanded to the limit of the machine tool processing stroke; for these modular array thin-walled multi-cavity parts, and when it is necessary to ensure the processing accuracy of the thin-walled multi-cavity parts, it is very difficult to clamp them using a general clamping method, and the adsorption clamping device manufactured using the tooling design method described in the present invention can well meet the clamping requirements, and the manufacturing cost is low. Combined with the processing principles and methods described in the present invention, thin-walled multi-cavity parts that meet high-precision requirements can be manufactured.

[0095] At the same time, Figure 6 The plane schematic diagrams of the multiple thin-walled multi-cavity parts shown highlight the auxiliary clamping position. As shown in the figure, there is a relatively wide rib in the middle position of the entire array surface, and the position of the rib is the position shown by the dotted line in the figure. At this time, a threaded clamping hole can be designed at a suitable position on the rib, and a thread can be opened at the corresponding position of the adsorption clamping device, and screws can be used for auxiliary clamping, or overlapping pressure plates can be used at the free positions such as the first overlap 61 and the second overlap 62 at the edge of the rib for auxiliary clamping; combined with the above examples, those skilled in the art can conceive that this method can be used for auxiliary clamping in places where such thin-walled multi-cavity parts have sufficient free positions.

[0096] In the description of the present invention, it should be noted that the terms "upper" and "lower" and the like indicating directions or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0097] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "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 directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0098] The above description is only a preferred embodiment of the present invention, which is only illustrative and not restrictive of the present invention. Those skilled in the art understand that many changes, modifications, and even equivalences may be made to the present invention within the spirit and scope defined by the claims of the present invention, but all of them will fall within the scope of protection of the present invention.

Claims

1. A method for clamping thin-walled multi-cavity parts, characterized in that: The clamping method comprises the following steps: S1: Determine the clamping adsorption force according to the characteristics of thin-walled multi-cavity parts; Clamping adsorption force formula: F′=P·A Among them, F' represents the clamping adsorption force; P represents the internal vacuum degree; A represents the adsorption area that maintains the clamping force; S2: Calculate the adsorption area to maintain the clamping force based on the milling force of the CNC milling machine and the clamping adsorption force; The calculation formula of milling force of CNC milling machine is: Where F represents the milling force; c F is the milling force coefficient; z is the number of milling cutter teeth; d0 represents the milling cutter diameter; k F Indicates the correction factor; a p Indicates the milling depth, that is, the size of the cut layer measured parallel to the milling cutter axis; a e Indicates the milling width, that is, the size of the cut layer measured perpendicular to the milling cutter axis; a f Indicates the feed per tooth; When the milling force and the adsorption force are balanced, the relationship between the milling force and the clamping adsorption force of the CNC milling machine is: F = μF′; The formula for the adsorption area to maintain the clamping force is: Among them, A represents the adsorption area for maintaining the clamping force; K represents the safety factor; μ represents the friction coefficient; S3: The number of adsorption holes required is calculated according to the adsorption area for maintaining the clamping force and the adsorption area of ​​a single adsorption hole, so that the adsorption force is evenly distributed on several adsorption holes, and the suction force of several adsorption holes is used to realize the adsorption clamping of thin-walled multi-cavity parts.

2. The method for clamping thin-walled multi-cavity parts according to claim 1, characterized in that: The specific contents of step S3 include: S31: Calculate the number of adsorption holes required in the adsorption end according to the adsorption area to maintain the clamping force: Where n represents the number of adsorption holes; S represents the area of ​​a single adsorption hole; S32: According to the calculated number of adsorption holes, a plurality of adsorption holes are evenly arranged on the adsorption end.

3. A clamping device for clamping thin-walled multi-cavity parts using the clamping method according to any one of claims 1 to 2, characterized in that: The clamping device includes an upper mold and a lower mold, the top of the upper mold is an adsorption end, and the adsorption end is adapted to the part to be clamped; the adsorption end is provided with a plurality of adsorption holes; the top of the lower mold is sealed and connected with the bottom of the upper mold, and the lower mold is provided with an exhaust hole and a breathable cavity, and the breathable cavity is connected with the exhaust hole; the plurality of adsorption holes on the upper mold are connected with the breathable cavity on the lower mold.

4. The clamping device according to claim 3, characterized in that: The connection between the upper mold and the lower mold is welded and sealed.

5. The clamping device according to claim 3, characterized in that: A sealing groove is arranged outside the air permeable cavity of the lower mold, an elastic sealing ring is arranged in the sealing groove, the sealing ring protrudes from the top surface of the air permeable cavity, and the bottom of the upper mold is sealed and connected to the top of the lower mold through the sealing ring.

6. The clamping device according to claim 5, characterized in that: The sealing ring protrudes upwards by 0.3mm to 0.5mm along the top surface of the air permeable cavity.

7. The clamping device according to claim 3, characterized in that: The adsorption end includes a protrusion and a concave cavity adapted to the structure of the part to be clamped, the protrusion is designed with a negative tolerance, and the height value of the protrusion is 0.2 mm higher than its standard value; The recessed cavity is designed with a positive tolerance, and the height of the recessed cavity is 0.2 mm lower than its standard height.

8. The clamping device according to claim 7, characterized in that: The raised portion of the adsorption end matches the structure of the cavity of the part to be clamped, and the recessed cavity of the adsorption end matches the structure of the thin wall of the part to be clamped.

9. The clamping device according to claim 7, characterized in that: A plurality of adsorption holes are evenly arranged on the raised portion of the adsorption end.

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