A device for processing inner holes of slender thin-walled ceramic-based composite pipes

Abstract

The present invention belongs to the technical field of ceramic-based composite material processing, and proposes a device for processing the inner hole of a slender, thin-walled ceramic-based composite material pipe. The processing device includes a special flexible tool, a clamping execution system, a material passing module, and a feeding motion system. The special flexible tool is composed of a hose with multiple small holes. The material passing module includes an abrasive pump, a material passing tube, a two-way joint, and an abrasive box. The feeding system includes a motor and a tube retracting and unretracting machine. After the abrasive is pumped in and flows out evenly, the machine tool is started to a stable speed, and the tube retracting and unretracting machine is rotated to repeatedly retract and pull the special flexible tool to complete the inner hole grinding of the thin-walled ceramic-based composite material. The present invention solves the problems of deformation and cutting vibration caused by traditional processing methods in the process of processing the inner hole of slender, thin-walled ceramic-based composite parts, as well as difficulties in cooling, lubrication, chip removal and chip breaking, severe tool wear, and deformation of the pipe positioning and clamping. It is suitable for the problem of thermal expansion and deformation of parts caused by high temperature during the processing of the inner hole of thin-walled ceramic-based composite materials.

Description

Technical Field

[0001] The invention relates to the technical field of ceramic matrix composite material processing, in particular to a device for processing the inner hole of a slender thin-walled ceramic matrix composite material pipe. Background Art

[0002] Ceramic-based composites have good mechanical properties and heat resistance and can be used to manufacture heavy structural parts. These composites have been widely used in the aerospace, shipbuilding, engineering machinery, automotive and electronics industries. For example, this material is used in the tail nozzle of aircraft engines and the thermal protection of rocket surfaces. For slender and thin-walled ceramic-based composites, the quality of the inner hole is an important factor affecting the application.

[0003] Thin-walled, slender tubular parts are typical weak-rigidity parts due to their large aspect ratio. They are prone to deformation and cutting vibration during machining, and are difficult to control in terms of machining dimensional accuracy and straightness. The inner holes of slender tubes are deep and long holes with limited machining space. Using traditional drilling methods, cooling, lubrication, chip removal and chip breaking are difficult, and heat easily accumulates, resulting in severe tool wear. In addition, high temperatures cause thermal expansion and deformation of parts, affecting machining dimensional accuracy.

[0004] Chinese patent CN201822229226.5 discloses a device for processing the inner hole of a slender shaft, including a base, a clamping device, a driving mechanism, a first processing tool holder fixedly arranged at one end of the base, and a second processing tool holder fixedly arranged at the other end of the base; the advantage of this invention is that both ends of the shaft to be processed are processed at one time on a single processing device, thereby improving the clamping and positioning accuracy of the machine tool and its processing efficiency. This patent is suitable for solving small deep holes in slender shafts, but the device still uses traditional boring or reaming and is only suitable for processing traditional materials to ensure accuracy. It is not suitable for processing the inner holes of slender thin-walled ceramic tubes.

[0005] This patent is different from the traditional thin-walled slender pipe processing device in that it uses flexible processing tools to process the inner hole of the slender thin-walled ceramic-based composite material. Summary of the Invention

[0006] The purpose of the present invention is to provide a slender thin-walled ceramic matrix composite material pipe inner hole processing device, which can realize the processing of large aspect ratio, thin-walled ceramic matrix composite materials, and ensure the roughness of the inner hole, and can process and produce large aspect ratio thin-walled pipes.

[0007] To achieve the above object, the technical solution of the present invention is:

[0008] A device for processing the inner hole of a slender, thin-walled ceramic-based composite material pipe comprises a flexible tool, a clamping execution system, a material passing module and a feeding motion system;

[0009] The flexible tool is located inside a slender, thin-walled ceramic-based composite tube and includes a truncated cone-shaped micro-blade 1, a sleeve 2, and a hose 3. The hose 3 is provided with several small holes for abrasive overflow. Several equidistant truncated cone-shaped micro-blades 1 are glued to the hose 3. Sleeves 2 with waist-shaped holes are installed between the truncated cone-shaped micro-blades 1. Each sleeve 2 has a waist-shaped hole. Both ends of the hose 3 are sealed with fillers.

[0010] The clamping execution system includes a bearing 5, gear I6, gear II7, a hollow stub shaft 8, and a stub shaft base 12. Gear I6 is located on the machine tool spindle, and gear II7 is pin-connected to the hollow stub shaft 8. Gears I6 and II7 form a parallel gear transmission, transmitting the power of the machine tool spindle to the hollow stub shaft 8. Bearing 5 is fixed to the stub shaft base 12, and the hollow stub shaft 8 is connected to the stub shaft base 12 by being assembled with the bearing 5. One end of the hollow stub shaft 8 is provided with a shoulder hole for connecting to the three-jaw chuck 9.

[0011] The slender thin-walled ceramic matrix composite material tube is installed in the hollow short shaft 8, one end of which is clamped by a three-jaw chuck 9, and the other end extends out of the hollow short shaft 8;

[0012] The feed motion system is located on both sides of the entire clamping execution system, and includes a tube-retracting and unretracting machine 10 and a tube-retracting and unretracting machine hose. The tube-retracting and unretracting machine 10 is located on both sides of the machine tool, one end of which passes through the tube-retracting and unretracting machine hose and the other end is directly connected to the other end of the hose 3, which is used for the linear relative motion of the flexible tool and the slender, thin-walled ceramic matrix composite material tube.

[0013] The material passing module is located around the machine tool, and includes a material passing tube, a two-way quick connector 4, an abrasive pump 14 and an abrasive box; the abrasive pump 14 is located on one side of the machine tool, one end of which is connected to the abrasive box, and the other end is connected to the material passing tube; the material passing tube and the tube retracting and unretracting hose are respectively connected to the other end of the hose 3 through the two-way quick connector 4; two abrasive boxes are set, respectively located at the two ends of the slender thin-walled ceramic-based composite material pipe, for receiving abrasive overflowed during processing and feeding; when the abrasive is pumped into the inside of the slender thin-walled ceramic-based composite material pipe until the abrasive flows out evenly, the machine tool is started until a stable speed is reached, the tube retracting and unretracting machine 10 is located at both ends of the machine tool, at the same height as the three-jaw chuck 9, and the tube retracting and unretracting machine 10 is rotated to repeatedly retract and pull the flexible tool to complete the inner hole grinding of the thin-walled ceramic-based composite material.

[0014] The sum of the maximum diameters of the hose 3 and the truncated cone-shaped micro-blade 1 is smaller than the inner diameter of the slender thin-walled ceramic-based composite material tube.

[0015] The inner diameter of the truncated cone micro blade is determined by the diameter of the hose 3 and the inner diameter of the slender thin-walled ceramic matrix composite material pipe. The truncated cone micro blade has a slope angle; the interval between each two truncated cone micro blades is the same.

[0016] The clamping system is located above the machine tool's spindle. The original three-jaw chuck at the spindle's edge is replaced with a gear, serving as Gear I6. Gear I6 and Gear II7 form a parallel gear transmission. A hollow stub shaft 8 ensures the extension of the hose 3. Bearings 5 ​​engage with the hollow stub shaft 8, which is then connected to the stub shaft base 12. This structure enables flexible left-right movement of the machining tool and rotation of the slender, thin-walled ceramic matrix composite tubing.

[0017] Compared with the prior art, the effects and benefits of the present invention are:

[0018] 1. The present invention adopts a flexible tool composed of a hose with a small hole, a frustum-shaped micro-blade with a certain angle and a sleeve with a waist-shaped hole added to the outside of the hose, which ensures the coaxiality during inner hole processing and avoids the phenomenon of scratching the hole wall to form spiral ripples during traditional drilling and boring. This tool avoids the deflection phenomenon caused by the insufficient rigidity of traditional processing tools themselves, and ensures the roundness of the inner hole of the processed thin-walled ceramic-based composite material.

[0019] 2. The present invention overcomes the shortcoming that existing processing equipment cannot directly achieve uniform processing of the inner holes of materials with large aspect ratios, especially in terms of the roughness, roundness and coaxiality of the inner holes of thin-walled ceramic-based composite materials. It utilizes the dynamic pressure grinding effect to achieve precise processing of the inner holes of thin-walled ceramic-based composite materials, realizing precise processing of the inner holes of thin-walled composite materials that cannot be achieved by traditional inner hole processing.

[0020] 3. The present invention has good motion stability and reasonable layout of various functional structures, which is convenient for integrated installation and transportation of the whole machine. The present invention has a high degree of automation, improves work efficiency, and reduces worker skill requirements and labor intensity.

[0021] 4. The present invention realizes the inner hole processing of slender thin-walled tubes of various material types by arranging fixtures of different specifications on the lathe working platform, and has high scalability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a cross-sectional schematic diagram of the installation of a flexible tool in a slender, thin-walled ceramic matrix composite tube.

[0023] Figure 2 (a) is a schematic cross-sectional view of the hose;

[0024] Figure 2(b) is a schematic diagram of the hose;

[0025] Figure 2(c) is a schematic cross-sectional view of a truncated cone-shaped micro-blade, Figure 2(d) is a schematic front view of a truncated cone-shaped micro-blade, and Figure 2(e) is a schematic side view of a truncated cone-shaped micro-blade;

[0026] Figure 2(f) is a schematic cross-sectional view of the sleeve, Figure 2(g) is a schematic front view of the sleeve, and Figure 2(h) is a schematic side view of the sleeve;

[0027] Figure 3 It is a schematic diagram of the installation of a device for processing the inner hole of a slender thin-walled ceramic matrix composite material pipe;

[0028] Figure 4 yes Figure 3 A-direction side view;

[0029] Figure 5 It is a schematic cross-sectional view of the clamping mechanism structure.

[0030] In the figure: 1- frustoconical micro blade; 2- sleeve; 3- hose; 4- two-way quick connector; 5- bearing; 6- gear I; 7- gear II; 8- hollow short shaft; 9- three-jaw chuck; 10- tube retracting and unretracting machine; 11- abrasive box I; 12- short shaft base; 13- abrasive box II; 14- abrasive pump. DETAILED DESCRIPTION

[0031] The specific implementation of the present invention is described in detail below in conjunction with the technical solutions and drawings.

[0032] like Figure 1-Figure 5 As shown, a flexible tool for machining the inner bore of an elongated, thin-walled ceramic-based composite pipe comprises a truncated cone-shaped micro-blade 1, a sleeve 2, and a flexible tube 3. The right end of the flexible tool is sealed with a filler. The tool is inserted through a three-jaw chuck 9, which holds one end of the elongated, thin-walled ceramic-based composite pipe, until it passes through and exits the pipe. The flexible tube 3, laden with abrasive particles, completely fills the inner bore of the elongated, thin-walled ceramic-based composite pipe, leaving a certain excess. A two-way quick connector 4 connects the unfilled end of the flexible tool to the feed pump's capillary tube and the tube retractor's hose. The tube retractor 10 is adjusted to the same height as the three-jaw chuck 9. Abrasive boxes I 11 and II 13 are placed at both ends of the elongated, thin-walled ceramic-based composite pipe to ensure that any excess abrasive flows into the boxes. Then, the abrasive pump 14 is powered on to pump the abrasive into the thin-walled ceramic matrix composite material tube until the abrasive flows out evenly. Then, the machine tool is started. After reaching a stable speed, the tube retracting and unretracting machine 10 rotates to repeatedly retract and unretract the tube, completing the inner hole grinding of the thin-walled ceramic matrix composite material. Figure 5The clamping system shown includes a bearing 5, gears I6, II7, a hollow stub shaft 8 with a shoulder on the right end, and a stub shaft base 12. Gears II7 and hollow stub shaft 8 are connected by a pin. Gears I6 and II7 form a parallel gear transmission, transmitting the machine tool spindle's power to the hollow stub shaft 8. The hollow stub shaft 8 is mounted on the stub shaft base 12. The shoulder on the right end of the hollow stub shaft 8 provides a hole for connection to a three-jaw chuck. Centering brackets can be added to the left and right sides of the three-jaw chuck as needed. A thin-walled ceramic matrix composite material is loaded into the hollow stub shaft, and the left end is extended to a certain length before being clamped in the three-jaw chuck. When processing a slender, thin-walled ceramic matrix composite pipe with a length of 5 meters and an inner diameter of 9 mm, a frustum-shaped micro-blade 1 with a maximum diameter of 8.5 mm and a width of 6 mm can be used. 0.2 mm is added to the diameter of the hose 3 to facilitate glue application. The sleeve 2 is 8 mm long, and the edge diameter of the waist-shaped hole is 1.5 mm.

Claims

1. A device for processing inner holes of slender thin-walled ceramic-based composite pipes, characterized in that: The device for processing the inner hole of an elongated thin-walled ceramic-based composite material pipe comprises a flexible tool, a clamping execution system, a material passing module and a feeding motion system; The flexible tool is located in a slender thin-walled ceramic-based composite material tube, and comprises a truncated cone-shaped micro-blade (1), a sleeve (2) and a hose (3); the hose (3) is provided with a plurality of small holes for abrasive overflow; a plurality of equidistant truncated cone-shaped micro-blades (1) are glued to the hose (3), and sleeves (2) with waist-shaped holes are installed between the truncated cone-shaped micro-blades (1), and each sleeve (2) has a waist-shaped hole; both ends of the hose (3) are sealed by fillers; The clamping execution system includes a bearing (5), a gear I (6), a gear II (7), a hollow short shaft (8) and a short shaft base (12); the gear I (6) is located on the main shaft of the machine tool, the gear II (7) is pin-connected to the hollow short shaft (8), and the gear I (6) and the gear II (7) form a parallel gear transmission to transmit the power of the main shaft of the machine tool to the hollow short shaft (8); the bearing (5) is fixed on the short shaft base (12), and the hollow short shaft (8) is connected to the short shaft base (12) by assembling with the bearing (5); the short shaft base (12) is fixed on the machine tool; a shoulder hole is provided at one end of the hollow short shaft (8) and is connected to the three-jaw chuck (9); A slender thin-walled ceramic matrix composite material tube is placed in the hollow short shaft (8), one end of the tube is clamped by a three-jaw chuck (9), and the other end extends out of the hollow short shaft (8); The feeding motion system is located on both sides of the entire clamping execution system, and includes a tube-retracting and unretracting machine (10) and a tube-retracting and unretracting machine hose; the tube-retracting and unretracting machine (10) is located on both sides of the machine tool, one end of which passes through the tube-retracting and unretracting machine hose, and the other end is directly connected to the other end of the hose (3), for relative movement between the flexible tool and the slender thin-walled ceramic-based composite material tube; The material flow module is located around the machine tool, and includes a material flow tube, a two-way quick connector (4), an abrasive pump (14) and an abrasive box; the abrasive pump (14) is located on one side of the machine tool, one end of which is connected to the abrasive box and the other end is connected to the material flow tube; the material flow tube and the tube retracting and unretracting machine hose are respectively connected to the other end of the hose (3) through the two-way quick connector (4); two abrasive boxes are provided, which are respectively located at the two ends of the slender thin-walled ceramic-based composite material tube, and are used to receive abrasives overflowed during processing and to supply materials; when the abrasive is pumped into the slender thin-walled ceramic-based composite material tube until the abrasive flows out evenly, the machine tool is started until a stable speed is reached, the tube retracting and unretracting machine (10) is located at both ends of the machine tool, at the same height as the three-jaw chuck (9), and the tube retracting and unretracting machine (10) is rotated to repeatedly retract and pull the flexible tool to complete the inner hole grinding of the thin-walled ceramic-based composite material; The sum of the maximum diameters of the hose (3) and the truncated cone-shaped micro-blade (1) is smaller than the inner diameter of the slender thin-walled ceramic-based composite material tube.

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