Tool changing device for efficient finish machining of deep holes in narrow space and machining method

Abstract

The invention belongs to the technical field of aerospace hole machining, and provides an efficient finish machining tool changing device for a deep hole in a narrow space and a machining method. The tool changing device comprises a drill body, a drill sleeve and a machining tool. The drill body has a coaxial state and a non-coaxial state on the drill sleeve, and under the coaxial state, machining equipment is controlled to conduct deep hole finish machining; and in a non-coaxial state, the replacement of the machining cutter can be realized without detaching the drill body. By means of the method, the problems that deep hole finish machining in a narrow space is difficult, and tool changing is complex are effectively solved, the tool changing process is simplified while the deep hole machining quality and stability are guaranteed, and the machining efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of aerospace hole-making processing, and relates to a tool-changing device and a processing method for high-efficiency fine machining of deep holes in a narrow space. Background Art

[0002] In the sub-assembly production links of large-scale high-end equipment such as aerospace, there are many requirements for fine machining of deep holes in complex and narrow spaces, and the axial space is even less than 500 mm, such as the connection between the wing and the fuselage, and the connection of the cabin door. Limited by the complex cavity structure, manual hand-held pneumatic drills with extended tools are mostly used for hole-making at present, with extremely poor stability, and single-hole machining requires more than 10 steps of segmented cutting, resulting in extremely low efficiency. How to achieve high-quality and high-efficiency fine machining of deep holes in a narrow space is of great significance for the mass production of high-end equipment.

[0003] Foreign research on automatic hole-making in small spaces started earlier. Sébastien Pereira of the French company Seti Technology invented the "drilling device with an automatically or controllably fed spindle with self-aligning spindle", with the patent number ZL201710628905.7. The device adopts a dual-motor drive mode, and the main motor and the auxiliary motor independently control the rotational movement and the feeding movement of the drilling machine respectively. Its gear set structure is compact, and the accuracy requirements for parts are relatively high. The spindle structure is processed by special processes, making the price extremely expensive. At the same time, it is very difficult to meet the requirements for the accuracy and stability of one-step hole-making, seriously restricting its wide application. Fu Rao et al. from Dalian University of Technology invented the "portable high-precision automatic feeding drilling equipment", with the patent number CN114734074A, which adopts a parallel layout of lead screws and guide rails, and the body length is relatively short. However, the tool and the spindle are in a series structure, and the overall size before installation also reaches twice the length of the tool, making it difficult to meet the requirements for fine machining of deep holes in narrow spaces. Yang Xinliang et al. from AVIC General Aircraft South China Aircraft Industry Co., Ltd. invented the "processing device for the connection hole of the aircraft wing and fuselage", with the patent number "ZL202223047466.6", including an automatic feeding drill, a drill jig and a boring tool. The two ends of the boring tool are respectively connected to the automatic feeding drill and the tool guiding hole. Under the combined action of the automatic feeding drill and the tool guiding hole, appropriate rotational speed and feeding speed are selected for processing. Among them, a drill bushing is installed outside the spindle. During the drilling process, the tool has a large jumping range and is easily affected by chips during work, which is not conducive to the stable operation of the spindle.

[0004] To sum up, when the existing deep-hole processing equipment and process methods change tools, the overall disassembly of the equipment is required, resulting in a large space required for installation and operation, limited application range, and low efficiency. There is an urgent need to develop a tool-changing device and a processing method for high-efficiency fine machining of deep holes in a narrow space. Summary of the Invention

[0005] In order to overcome the problem that existing processing equipment cannot achieve deep hole fine machining in a narrow space, the present invention proposes a tool changing device and a processing method for efficient deep hole fine machining in a narrow space.

[0006] The technical solution of the present invention:

[0007] A tool changing device for efficient deep hole fine machining in a narrow space, comprising a drill body 1, a drill sleeve 2 and a processing tool 3;

[0008] The drill body 1 includes a coupling 101, a front end 102 of the drill body and a power part 103 of the drill body; an outer circle is provided at one end of the front end 102 of the drill body away from the coupling 101, and the outer circle is provided with a positioning keyway. The other end of the front end 102 of the drill body is installed at the front end of the power part 103 of the drill body through the coupling 101. The power part 103 of the drill body is installed on the side of the drill body away from the processing side and moves along the processing direction to provide power for hole making processing;

[0009] The drill sleeve 2 includes a hydraulic cylinder 201, a pressing block 202 and a drill sleeve frame 203; a V-shaped groove positioning block is provided at the top of the drill sleeve frame 203, a positioning key is provided below the V-shaped groove positioning block, and a tool guiding hole is provided in the drill sleeve frame 203. The drill body 1 can move up and down along the positioning key on the drill sleeve frame 203 and has two states: coaxial and non-coaxial. The lower end of the drill sleeve frame 203 is threadedly connected to the hydraulic cylinder 201; the front end of the piston of the hydraulic cylinder 201 is threadedly connected to the pressing block 202; the pressing block 202 has an arc surface with a radius of curvature greater than the outer circle radius of the front end 102 of the drill body, and together with the V-shaped groove positioning block and the positioning key at the top of the drill sleeve frame 203, it realizes the positioning of the front end 102 of the drill body and ensures the coaxiality of the front end 102 of the drill body and the drill sleeve frame 203 during work; an outer circle is provided on the side of the drill sleeve frame 203 close to the processing side, and the outer circle is matched with the inner hole of the drill template 401 to fix the drill sleeve frame 203;

[0010] The processing tool 3 includes a bushing 301 and a tool body 302; the bushing 301 is a ring, the inner circular hole of which is matched with the rear end of the tool body 302, and the outer cylindrical surface forms a small clearance fit with the tool guiding hole of the drill sleeve frame 203 to realize the guiding function of the tool; the diameter of the tool guiding hole of the drill sleeve frame 203 is larger than the outer diameter of the cutting edge of the tool body 302. Each time the tool is replaced, the bushing 301 and the tool body 302 are taken out of the drill sleeve frame 203 together.

[0011] Furthermore, when the drill body 1 and the drill sleeve frame 203 are in a non-coaxial state, the processing tool 3 performs a tool changing operation and moves axially along the drill sleeve frame 203 and is pulled out from the side away from the drill body 1.

[0012] Furthermore, during processing, only the coupling 101 needs to be separated from the tool body 302, the hydraulic cylinder 201 is retracted, and the drill body 1 is moved downward to realize tool replacement in a narrow space.

[0013] A processing method for a tool-changing device for high-efficiency finish machining of deep holes in a narrow space. The machining steps in the narrow space are as follows:

[0014] S1. Clamp the workpiece using the drill template 401, and install the drill bushing frame 203 on the drill template 401;

[0015] S2. Install the drill body 1 on the drill bushing 2, so that the outer circular positioning keyway at the front end 102 of the drill body is stuck at the bottom of the internal positioning key in the drill bushing frame 203, the outer circle of the front end 102 of the drill body contacts the V-shaped groove positioning block of the drill bushing frame 203, and the drill body 1 and the drill bushing frame 203 are in a coaxial state;

[0016] S3. Insert the processing tool 3 together into the tool mating hole of the drill bushing frame 203;

[0017] S4. Lift the drill body 1 upward, the hydraulic cylinder 201 drives the pressing block 202 to rise, press the front end 102 of the drill body, and fix the drill body 1 on the drill bushing frame 203;

[0018] S5. Connect the processing tool 3 with the coupling 101;

[0019] S6. Perform automatic hole-making processing through program control.

[0020] After the machining is completed, a tool-changing operation in the narrow space is required. The tool-changing operation steps are as follows:

[0021] S1. Unscrew the end of the processing tool 3 from the coupling 101, and separate the drill body 1 from the processing tool 3;

[0022] S2. Hold the drill body 1 by hand, turn on the switch of the hydraulic cylinder 201, separate the pressing block 202 from the front end 102 of the drill body, and the drill body 1 descends to the bottom of the chute of the drill bushing frame 203, and the drill body 1 reaches a non-coaxial state on the drill bushing frame 203;

[0023] S3. Withdraw the processing tool 3 from the drill bushing frame 203 towards the machining side, and insert a new processing tool 3 along the tool guiding hole of the drill bushing frame 203;

[0024] S4. Lift the drill body 1 upward, the hydraulic cylinder 201 drives the pressing block 202 to rise, press the front end 102 of the drill body, and fix the drill body 1 on the drill bushing frame 203;

[0025] S5. Connect the new processing tool 3 with the coupling 101.

[0026] Advantages of the present invention: For the need of precision finishing of deep holes in narrow spaces, the present invention provides a device and method for automatic deep hole machining and portable tool replacement in narrow spaces, especially in spaces where the axial length is less than the sum of the drill body and the tool length. The machining tool can be replaced by moving the drill body, solving the problem of difficult tool replacement in narrow spaces. Brief Description of the Drawings

[0027] Figure 1 Overall structure diagram of the device required for the method of high-efficiency precision finishing of deep holes in narrow spaces;

[0028] Figure 2 Layout diagram of the device and its complete tooling;

[0029] Figure 3 Partial cross-sectional view of the chute;

[0030] Figure 4 Fitting partial cross-sectional view of the front end of the drill body;

[0031] Figure 5 Flowchart of the method for high-efficiency precision finishing of deep holes in narrow spaces; where (a) is step 1 of the machining method, the drill bushing frame 203 is installed on the drill template 401, (b) is step 2 of the machining method, the drill body 1 is installed in the drill bushing 2, (c) is step 3 of the machining method, the machining tool 3 extends into the tool mating hole of the tool drill bushing frame 203, (d) is step 4 of the machining method, the drill body 1 is fixed to the drill bushing frame 203, (e) is step 5 of the machining method, the machining tool 5 is connected to the coupling 101;

[0032] Figure 6 Detail drawing of the front end of the drill body in the flowchart of the method for high-efficiency precision finishing of deep holes in narrow spaces;

[0033] Figure 7 Flowchart of the method for tool replacement in narrow spaces; where (a) is step 1 of the tool replacement method, the drill body 1 is separated from the machining tool 3, (b) is step 2 of the tool replacement method, the drill body 1 is not coaxial with the drill bushing frame 203, (c) is step 3 of the tool replacement method, the new machining tool 3 is inserted into the tool guide hole of the drill bushing frame 203;

[0034] In the figure: 1 - drill body, 101 - coupling, 102 - front end of the drill body, 103 - power part of the drill body, 2 - drill bushing, 201 - hydraulic cylinder, 202 - pressing block, 203 - drill bushing frame, 3 - machining tool, 301 - bushing, 302 - tool body, 4 - drill jig tooling and workpiece, 401 - drill template, 402 - workpiece to be machined. Detailed Implementation Manner

[0035] The following further illustrates the detailed implementation manner of the present invention in combination with the drawings and technical solutions.

[0036] Embodiment 1

[0037] Figure 1 The structure required to implement the high-efficiency finish machining method for deep holes in a narrow space is shown. Its structure mainly consists of a drill body 1, a drill bushing 2, and a machining tool 3. Among them, the drill body 1 is the main structure of the feed drill, including a coupling 101, a front end 102 of the drill body, and a power part 103 of the drill body; an outer circle is provided at one end of the front end 102 of the drill body away from the coupling 101, and the outer circle is provided with a positioning keyway. The other end of the front end 102 of the drill body is installed at the front end of the power part 103 of the drill body through the coupling 101. The power part 103 of the drill body is installed on the side of the drill body 1 away from the machining side and moves along the machining direction to provide power for hole-making machining; the top of the drill bushing frame 203 has a V-shaped groove positioning block, a positioning key is provided below the V-shaped groove positioning block, and the drill bushing frame 203 is provided with a tool guiding hole; the drill body 1 can move up and down along the positioning key on the drill bushing frame 203 and has two states: coaxial and non-coaxial; the lower end of the drill bushing frame 203 is threadedly connected to the hydraulic cylinder 201; the front end of the piston of the hydraulic cylinder 201 is threadedly connected to the pressing block 202; the pressing block 202 has an arc surface with a radius of curvature greater than the outer circle radius of the front end 102 of the drill body, and it, together with the V-shaped groove positioning block and the positioning key at the top of the drill bushing frame 203, realizes the positioning of the front end 102 of the drill body and ensures the coaxiality between the front end 102 of the drill body and the drill bushing frame 203 during operation; an outer circle is provided on the side of the drill bushing frame 203 close to the machining side, and the outer circle is matched with the inner hole of the drill template 401 to fix the drill bushing frame 203; the machining tool 3 includes a bushing 301 and a tool body 302. The bushing 301 is a wear-resistant material ring, the inner hole is matched with the rear end of the tool body 302, and the outer cylindrical surface forms a small clearance fit with the drill bushing frame 203; the inner hole diameter of the drill bushing frame 203 is larger than the outer diameter of the cutting edge of the tool body 302, and each time the tool is replaced, the tool 3 is withdrawn from the side of the drill bushing frame 203 away from the drill body 1.

[0038] In this embodiment, refer to the process of implementing the high-efficiency finish machining method for deep holes in a narrow space Figure 5 , and the specific implementation steps of the high-efficiency finish machining method for deep holes in a narrow space are as follows:

[0039] S1. Use the drill template 401 to clamp the workpiece and install the drill bushing frame 203 on the drill template 401;

[0040] S2. Install the drill body 1 on the drill bushing 2, so that the positioning keyway of the outer circle of the front end 102 of the drill body is stuck at the bottom of the positioning key inside the drill bushing frame 203, and the outer circle of the front end 102 of the drill body contacts the V-shaped groove positioning block of the drill bushing frame 203, and the drill body 1 and the drill bushing frame 203 are in a coaxial state;

[0041] S3. Insert the machining tool 3 together into the tool mating hole of the drill bushing frame 203;

[0042] S4. Lift the drill body 1 upward. The hydraulic cylinder 201 drives the pressing block 202 to rise, pressing the front end 102 of the drill body, and fixing the drill body 1 on the drill bushing frame 203.

[0043] S5. Connect the machining tool 3 with the coupling 101.

[0044] S6. Perform automatic hole-making machining through program control.

[0045] In this embodiment, when the axial machining space is only slightly larger than the length of the drill body 1, by separately installing the machining tool 3 and the drill body 1, convenient and efficient deep-hole high-precision finishing can be achieved.

[0046] Embodiment 2

[0047] After the completion of the above-mentioned Embodiment 1, it is necessary to replace the machining tool 3. In this embodiment, referring to the method flow for replacing the tool in a narrow space Figure 7 , the specific steps for tool replacement in a narrow space are as follows:

[0048] S1. Unscrew the end of the machining tool 3 from the coupling 101 to separate the drill body 1 from the machining tool 3.

[0049] S2. Hold the drill body 1 by hand, turn on the switch of the hydraulic cylinder 201, separate the pressing block 202 from the front end 102 of the drill body, and lower the drill body 1 to the bottom of the chute of the drill bushing frame 203, so that the drill body 1 is in a non-coaxial state on the drill bushing frame 203.

[0050] S3. Pull out the machining tool 3 from the drill bushing frame 203 towards the machining side, and insert the new machining tool 3 along the tool guiding hole of the drill bushing frame 203.

[0051] S4. Lift the drill body 1 upward. The hydraulic cylinder 201 drives the pressing block 202 to rise, pressing the front end 102 of the drill body, and fixing the drill body 1 on the drill bushing frame 203.

[0052] S5. Connect the new machining tool 3 with the coupling 101.

Claims

1. A high-efficiency finishing tool-changing device for deep holes in a narrow space, characterized in that The deep-hole high-efficiency finishing tool-changing device includes a drill body (1), a drill bushing (2), and a processing tool (3). The drill body (1) includes a coupling (101), a front end of the drill body (102), and a power part of the drill body (103); an outer circle is provided at one end of the front end of the drill body (102) away from the coupling (101), and the outer circle is provided with a positioning keyway. The other end of the front end of the drill body (102) is installed at the front end of the power part of the drill body (103) through the coupling (101). The power part of the drill body (103) is installed on the side of the drill body away from the processing side and moves along the processing direction to provide power for hole-making processing. The drill bushing (2) includes a hydraulic cylinder (201), a pressing block (202), and a drill bushing frame (203); the drill body (1) moves up and down in the drill bushing frame (203) and has two states of coaxial and non-coaxial; the lower end of the drill bushing frame (203) is connected to the hydraulic cylinder (201); the front end of the piston of the hydraulic cylinder (201) is connected to the pressing block (202); the pressing block (202) and the drill bushing frame (203) jointly achieve the positioning of the front end of the drill body (102) to ensure the coaxiality of the front end of the drill body (102) and the drill bushing frame (203) during work; the drill bushing frame (203) is fixed through a drill template (401). The processing tool (3) includes a bushing (301) and a tool body (302); the bushing (301) is a ring, the inner circular hole of which is matched with the rear end of the tool body (302), and the outer cylindrical surface forms a small clearance fit with the tool guiding hole of the drill bushing frame (203) to achieve the guiding effect of the tool.

2. The high-efficiency finishing tool-changing device for deep holes in a narrow space according to claim 1, wherein, The top of the drill bushing frame (203) has a V-shaped groove positioning block, and a positioning key is provided below the V-shaped groove positioning block; a tool guiding hole is provided on the side of the drill bushing frame (203) close to the processing side; an outer circle is provided on the side of the drill bushing frame (203) away from the processing side, and the outer circle is matched with the inner hole of the drill template (401) to fix the drill bushing frame (203); the drill body (1) can move up and down along the positioning key on the drill bushing frame (203) and has two states of coaxial and non-coaxial.

3. The deep-hole high-efficiency finishing tool-changing device in a narrow space according to claim 2, wherein The pressing block (202) has an arc surface with a radius of curvature greater than the outer circle radius of the front end of the drill body (102), and it, together with the V-shaped groove positioning block and the positioning key at the top of the drill bushing frame (203), jointly achieves the positioning of the front end of the drill body (102) to ensure the coaxiality of the front end of the drill body (102) and the drill bushing frame (203) during work.

4. The tool changing device for high-efficiency finish machining of deep holes in a narrow space according to claim 2, characterized in that, The diameter of the tool guiding hole of the drill bushing frame (203) is larger than the outer diameter of the cutting edge of the tool body (302). Each time the tool is changed, the bushing (301) and the tool body (302) are taken out of the drill bushing frame (203) together.

5. The tool changing device for high-efficiency finish machining of deep holes in a narrow space according to claim 1, characterized in that, When the drill body (1) and the drill bushing frame (203) are in a non-coaxial state, the processing tool (3) performs a tool-changing operation and moves axially along the drill bushing frame (203) and is pulled out from the side away from the drill body (1).

6. The deep-hole high-efficiency finish machining tool changing device and machining method in a narrow space according to claim 1, characterized in that, During processing, only need to separate the coupling (101) from the tool body (302), retract the hydraulic cylinder (201), and move the drill body (1) downward to achieve tool change in a narrow space.

7. A machining method for a tool-changing device for high-efficiency finish machining of deep holes in a narrow space as described in claim 1, characterized in that, The processing steps in a narrow space are as follows: S1. Clamp the workpiece using the drill template (401), and install the drill bushing frame (203) on the drill template (401); S2. Install the drill body (1) on the drill bushing (2), so that the outer circular positioning keyway at the front end (102) of the drill body is stuck at the bottom of the internal positioning key in the drill bushing frame (203), the outer circle of the front end (102) of the drill body contacts the V-groove positioning block of the drill bushing frame (203), and the drill body (1) and the drill bushing frame (203) are in a coaxial state; S3. Insert the processing tool (3) into the tool mating hole of the drill bushing frame (203); S4. Lift the drill body (1) upward, the hydraulic cylinder (201) drives the pressing block (202) to rise, press the front end (102) of the drill body, and fix the drill body (1) on the drill bushing frame (203); S5. Connect the processing tool (3) to the coupling (101); S6. Perform automatic hole-making processing through program control.

8. A machining method of a tool-changing device for high-efficiency finish machining of deep holes in a narrow space according to claim 1, characterized in that, The tool-changing steps in a narrow space are as follows: S1. Unscrew the end of the processing tool (3) from the coupling (101), and separate the drill body (1) from the processing tool (3); S2. Hold the drill body (1) by hand, turn on the switch of the hydraulic cylinder (201), separate the pressing block (202) from the front end (102) of the drill body, and the drill body (1) descends to the bottom of the chute of the drill bushing frame (203), and the drill body (1) reaches a non-coaxial state on the drill bushing frame (203); S3. Withdraw the processing tool (3) from the drill bushing frame (203) towards the processing side, and insert a new processing tool (3) along the tool guiding hole of the drill bushing frame (203); S4. Lift the drill body (1) upward, the hydraulic cylinder (201) drives the pressing block (202) to rise, press the front end (102) of the drill body, and fix the drill body (1) on the drill bushing frame (203); S5. Connect the new processing tool (3) to the coupling (101).

Images