Deep hole efficient finishing tool changing device in narrow space and machining method

Abstract

This invention belongs to the field of aerospace hole machining technology, and proposes a high-efficiency tool changing device and machining method for deep hole finishing in confined spaces. The tool changing device includes a drill body, a drill bushing, and machining tools; the drill body has two states on the drill bushing: coaxial and non-coaxial. In the coaxial state, the machining equipment is controlled to perform deep hole finishing; in the non-coaxial state, the machining tools can be changed without disassembling the drill body. This invention effectively solves the problems of difficult hole making and complex tool changing in deep hole finishing in confined spaces, simplifying the tool changing process and improving machining efficiency while ensuring the quality and stability of deep hole machining.

Description

Technical Field

[0001] This invention belongs to the field of aerospace hole-making technology, and relates to a tool changing device and processing method for high-efficiency precision machining of deep holes in a confined space. Background Technology

[0002] In the assembly and production of large, high-end equipment such as aerospace equipment, there is a significant demand for precision machining of deep holes within complex and confined spaces, with axial space sometimes less than 500mm, such as at wing-fuselage joints and door joints. Due to the complex cavity structures, current methods often involve manual hand-held air drills with extended cutting tools, resulting in extremely poor stability and requiring more than 10 steps of segmented cutting for single-hole machining, leading to very low efficiency. Achieving high-quality, high-efficiency precision machining of deep holes within confined spaces is of great significance for the mass production of high-end equipment.

[0003] Research on automated drilling in confined spaces began earlier abroad. Sébastien Pereira of the French company Cetie Technologies invented a "drilling device with a self-aligning spindle and automatic or controlled feed speed," patent number ZL201710628905.7. This device uses a dual-motor drive mode, with the main motor and auxiliary motor independently controlling the drill's rotation and feed motions. Its gear set structure is compact, and the precision requirements for components are high. The spindle structure is manufactured using special processes, making it extremely expensive. Furthermore, achieving the required precision and stability in single-drilling operations is difficult, severely limiting its widespread application. Fu Rao et al. of Dalian University of Technology invented a "portable high-precision automatic feed drilling equipment," patent number CN114734074A. This device uses a parallel screw and guide rail layout, resulting in a shorter machine body. However, the tool and spindle are connected in series, and the overall size before installation is twice the length of the tool, making it difficult to meet the needs of deep hole precision machining in confined spaces. Yang Xinliang and others from AVIC General Aircraft South China Aircraft Industry Co., Ltd. invented "A Machining Device for Aircraft Wing-Fuselage Connection Holes," patent number "ZL202223047466.6," which includes an automatic feed drill, a drill jig, and a boring bar. The two ends of the boring bar are connected to the automatic feed drill and a tool guide hole, respectively. With the cooperation of the automatic feed drill and the tool guide hole, a suitable rotational speed and feed rate are selected for machining. The spindle is externally fitted with a drill bushing. During drilling, the tool runout is large, and it is easily affected by chips, which is detrimental to the stable operation of the spindle.

[0004] In summary, existing deep hole machining equipment and processes require complete disassembly of the equipment for tool changes, resulting in a large installation and operation space, limited application scope, and low efficiency. There is an urgent need to develop a high-efficiency tool changing device and machining method for deep hole finishing in confined spaces. Summary of the Invention

[0005] To overcome the problem that existing processing equipment cannot achieve deep hole precision machining in a confined space, this invention proposes a tool changing device and processing method for high-efficiency deep hole precision machining in a confined space.

[0006] The technical solution of the present invention:

[0007] A tool changing device for high-efficiency finishing of deep holes in a confined space includes a drill body 1, a drill bushing 2, and a machining tool 3;

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

[0009] The drill bushing 2 includes a hydraulic cylinder 201, a clamping block 202, and a drill bushing frame 203. The drill bushing frame 203 has a V-groove positioning block at the top and a positioning key below the V-groove positioning block. The drill bushing frame 203 has a tool guide hole. The drill body 1 can move up and down on the drill bushing frame 203 along the positioning key, and has two states: coaxial and non-coaxial. The lower end of the drill bushing frame 203 is threaded to the hydraulic cylinder 201. The piston front end of the hydraulic cylinder 201 is threaded to the clamping block 202. The clamping block 202 has an arc surface with a radius of curvature larger than the outer radius of the drill body front end 102. It, together with the V-groove positioning block and the positioning key at the top of the drill bushing frame 203, positions the drill body front end 102, ensuring the coaxiality of the drill body front end 102 and the drill bushing frame 203 during operation. The drill bushing frame 203 has an outer circle near the machining side, which mates with the inner hole of the drill template 401 to fix the drill bushing frame 203.

[0010] The machining tool 3 includes a bushing 301 and a tool body 302. The bushing 301 is a ring with its inner hole fitting with the rear end of the tool body 302 and its outer cylindrical surface fitting with the tool guide hole of the drill bushing frame 203 with a small clearance to guide the tool. The diameter of the tool guide 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 pulled out of the drill bushing frame 203 together.

[0011] Furthermore, when the drill body 1 and the drill sleeve frame 203 are in a non-axial state, the machining tool 3 performs a tool change operation, moves along the axial direction of the drill sleeve frame 203, and is pulled out from the side away from the drill body 1.

[0012] Furthermore, during processing, it is only necessary to separate the coupling 101 from the tool body 302, retract the hydraulic cylinder 201, and move the drill body 1 downward, thereby realizing tool replacement in a confined space.

[0013] A machining method for a high-efficiency tool changing device for deep hole finishing in a confined space, comprising the following machining steps:

[0014] S1. Use the drill template 401 to clamp the workpiece and install the drill sleeve frame 203 on the drill template 401;

[0015] S2. Install the drill body 1 on the drill sleeve 2, so that the outer circle positioning keyway of the drill body front end 102 is locked in the bottom of the positioning key inside the drill sleeve frame 203, the outer circle of the drill body front end 102 contacts the V-groove positioning block of the drill sleeve frame 203, and the drill body 1 and the drill sleeve frame 203 are in a coaxial state.

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

[0017] S4. Lift the drill body 1 upwards. The hydraulic cylinder 201 drives the clamping block 202 to rise, clamping the front end 102 of the drill body and fixing the drill body 1 on the drill sleeve frame 203.

[0018] S5. Connect the machining tool 3 to the coupling 101;

[0019] S6. Automatic hole making is performed through program control.

[0020] After machining is completed, a tool change operation needs to be performed in a confined space. The tool change operation steps are as follows:

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

[0022] S2. Hold the drill body 1 and turn on the hydraulic cylinder 201 switch. The clamping block 202 separates from the front end 102 of the drill body. The drill body 1 descends to the bottom of the slide groove of the drill sleeve frame 203. The drill body 1 reaches the non-axis state on the drill sleeve frame 203.

[0023] S3. Pull the machining tool 3 out of the drill bushing frame 203 toward the machining side, and insert the new machining tool 3 along the tool guide hole of the drill bushing frame 203;

[0024] S4. Lift the drill body 1 upwards. The hydraulic cylinder 201 drives the clamping block 202 to rise, clamping the front end 102 of the drill body and fixing the drill body 1 on the drill sleeve frame 203.

[0025] S5. Connect the new machining tool 3 to the coupling 101.

[0026] The beneficial effects of the present invention are as follows: In view of the need for deep hole precision machining in confined spaces, the present invention provides a device and method for automatic deep hole machining and portable tool replacement in confined spaces, especially in spaces where the axial length is less than the length of the drill body plus the tool. The machining tool can be replaced by moving the drill body, which solves the problem of difficult tool replacement in confined spaces. Attached Figure Description

[0027] Figure 1 Overall structural diagram of the apparatus required for achieving efficient deep hole finishing in confined spaces;

[0028] Figure 2 This is a layout diagram of the device and its complete tooling;

[0029] Figure 3 This is a sectional view of the chute section;

[0030] Figure 4 A sectional view of the drill bit's front end;

[0031] Figure 5 A flowchart of a method for efficient precision machining of deep holes in a confined space is provided. In step 1, the drill bushing frame 203 is installed on the drill template 401. In step 2, the drill body 1 is installed on the drill bushing 2. In step 3, the machining tool 3 is inserted into the tool mating hole of the tool drill bushing frame 203. In step 4, the drill body 1 is fixed on the drill bushing frame 203. In step 5, the machining tool 5 is connected to the coupling 101.

[0032] Figure 6 Detailed diagram of the drill body front end in the process of achieving efficient deep hole finishing in a confined space;

[0033] Figure 7 A flowchart for a tool changing method in a confined space is provided; (a) is step 1 of the tool changing method, in which the drill body 1 is separated from the machining tool 3; (b) is step 2 of the tool changing method, in which the drill body 1 and the drill bushing frame 203 are not coaxial; and (c) is step 3 of the tool changing method, in which the new machining tool 3 is inserted into the tool guide hole of the drill bushing frame 203.

[0034] In the diagram: 1-Drill body, 101-Coupling, 102-Drill body front end, 103-Drill body power unit, 2-Drill bushing, 201-Hydraulic cylinder, 202-Clamping block, 203-Drill bushing frame, 3-Machining tool, 301-Bushing, 302-Tool body, 4-Drill jig and workpiece, 401-Drill template, 402-Workpiece to be machined. Detailed Implementation

[0035] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0036] Example 1

[0037] Figure 1 The diagram shows the structure required for achieving efficient deep hole finishing in this confined space. The structure mainly consists of a drill body 1, a drill sleeve 2, and a machining tool 3. The drill body 1 is the main structure of the feed drill, including a coupling 101, a drill body front end 102, and a drill body power unit 103. The drill body front end 102, away from the coupling 101, has an outer circle with a locating keyway. The other end of the drill body front end 102 is mounted on the front end of the drill body power unit 103 via the coupling 101. The drill body power unit 103 is mounted on the side of the drill body 1 away from the machining process and moves along the machining direction to provide power for hole making. The drill sleeve frame 203 has a V-groove locating block at the top, and a locating key below the V-groove locating block. The drill sleeve frame 203 has a tool guide hole. The drill body 1 can move up and down along the locating key on the drill sleeve frame 203, exhibiting both coaxial and non-coaxial states. The lower end of the drill sleeve frame 203 is threadedly connected to a hydraulic cylinder 201. The piston front end of the hydraulic cylinder 201 is connected to a clamping block. 202 threaded connection; the clamping block 202 has an arc surface with a radius of curvature greater than the outer radius of the drill body front end 102, which, together with the V-groove positioning block and positioning key on the top of the drill bushing frame 203, achieves the positioning of the drill body front end 102, ensuring the coaxiality of the drill body front end 102 and the drill bushing frame 203 during operation; the drill bushing frame 203 has an outer circle near the machining side, which fits 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 ring, the inner hole of which fits with the rear end of the tool body 302, and the outer cylindrical surface of which forms a small clearance fit with the drill bushing frame 203; the inner diameter of the drill bushing frame 203 is greater than the outer diameter of the cutting edge of the tool body 302. Each time the tool is changed, the tool 3 is pulled out from the side of the drill bushing frame 203 away from the drill body 1.

[0038] In this embodiment, the process of achieving efficient precision machining of deep holes in confined spaces is referenced. Figure 5 The specific steps for the high-efficiency precision machining method of deep holes in confined spaces are as follows:

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

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

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

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

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

[0044] S6. Automatic hole making is performed through program control.

[0045] In this embodiment, when the axial machining space is only slightly larger than the length of the drill body 1, the machining tool 3 can be installed separately from the drill body 1 to achieve convenient and efficient deep hole finishing.

[0046] Example 2

[0047] After completing Embodiment 1, the machining tool 3 needs to be replaced. In this embodiment, a method for replacing the tool in a confined space is referenced. Figure 7 The specific steps for changing tools in a confined space are as follows:

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

[0049] S2. Hold the drill body 1 and turn on the hydraulic cylinder 201 switch. The clamping block 202 separates from the front end 102 of the drill body. The drill body 1 descends to the bottom of the slide groove of the drill sleeve frame 203. The drill body 1 reaches the non-axis state on the drill sleeve frame 203.

[0050] S3. Pull the machining tool 3 out of the drill bushing frame 203 toward the machining side, and insert the new machining tool 3 along the tool guide hole of the drill bushing frame 203;

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

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

Claims

1. A deep hole high efficient finishing tool changing device in a narrow space, characterized in that, The deep hole high-efficiency finishing tool changing device comprises a drill body (1), a drill sleeve (2) and a machining tool (3); The drill body (1) comprises a coupling (101), a drill body front end (102) and a drill body power part (103); the drill body front end (102) is provided with an outer circle at an end away from the coupling (101), the outer circle is provided with a positioning key groove, the other end of the drill body front end (102) is installed at the front end of the drill body power part (103) through the coupling (101), and the drill body power part (103) is installed at the side away from machining of the drill body and moves in the machining direction to provide power for hole machining; The drill sleeve (2) comprises a hydraulic cylinder (201), a pressing block (202) and a drill sleeve frame (203); the drill body (1) moves up and down in the drill sleeve frame (203) and has coaxial and non-coaxial two states; the lower end of the drill sleeve frame (203) is connected with the hydraulic cylinder (201); the front end of the piston of the hydraulic cylinder (201) is connected with the pressing block (202); the pressing block (202) and the drill sleeve frame (203) jointly realize positioning of the drill body front end (102) and guarantee coaxiality of the drill body front end (102) and the drill sleeve frame (203) during work; the drill sleeve frame (203) is fixed through a drill template (401); The machining tool (3) comprises a bushing (301) and a tool body (302); the bushing (301) is a circular ring, the inner hole of the bushing (301) is matched with the rear end of the tool body (302), the outer cylindrical surface of the bushing (301) is matched with the tool guide hole of the drill sleeve frame (203) to form a small gap to realize the guiding effect of the tool.

2. The deep hole efficient finishing tool changing device in a narrow space according to claim 1, characterized in that, The drill sleeve frame (203) is provided with a V-shaped groove positioning block at the top, and is provided with a positioning key below the V-shaped groove positioning block; the drill sleeve frame (203) is provided with a tool guide hole near the machining side; the drill sleeve frame (203) is provided with an outer circle away from the machining side, the outer circle is matched with the inner hole of the drill template (401) to fix the drill sleeve frame (203); the drill body (1) can move up and down along the positioning key in the drill sleeve frame (203) and has coaxial and non-coaxial two states.

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

4. The deep hole efficient finishing tool changing device in a narrow space according to claim 2, characterized in that, The diameter of the tool guide hole of the drill sleeve frame (203) is greater than the outer diameter of the tool edge of the tool body (302), and the bushing (301) and the tool body (302) are taken out from the drill sleeve frame (203) together each time the tool is replaced.

5. The deep hole efficient finishing tool changing device in a narrow space according to claim 1, characterized in that, When the drill body (1) and the drill sleeve frame (203) are in the non-coaxial state, the machining tool (3) performs the tool changing operation and moves axially along the drill sleeve frame (203) to pull out from the side away from the drill body (1).

6. The deep hole efficient finishing tool changing device in a narrow space according to claim 1, characterized in that, During machining, only the coupling (101) and the tool body (302) need to be separated, the hydraulic cylinder (201) is retracted, and the drill body (1) is moved downward to realize tool replacement in a narrow space.

7. The method of claim 1, wherein the method is characterized by: The processing steps in the narrow space are as follows: S1. Clamping the workpiece with the drill template (401), and installing the drill sleeve frame (203) on the drill template (401); S2. Installing the drill body (1) on the drill sleeve (2); S3. Extending the processing tool (3) into the tool guide hole of the drill sleeve frame (203); S4. Lifting the drill body (1) upward, the hydraulic cylinder (201) drives the pressing block (202) to rise, presses the front end (102) of the drill body, and fixes the drill body (1) on the drill sleeve frame (203); S5. Connecting the processing tool (3) with the coupling (101); S6. Automatic hole making processing through program control.

8. The method of claim 1, wherein the method is characterized by: The tool changing steps in the narrow space are as follows: S1. Rotating the end of the processing tool (3) out of the coupling (101), and separating the drill body (1) from the processing tool (3); S2. Holding the drill body (1) by hand, turning on the hydraulic cylinder (201) switch, separating the pressing block (202) from the front end (102) of the drill body, lowering the drill body (1) to the bottom of the slide groove of the drill sleeve frame (203), and reaching the different shaft state of the drill body (1) on the drill sleeve frame (203); S3. Pulling out the processing tool (3) from the drill sleeve frame (203) to the processing side, and inserting the new processing tool (3) along the tool guide hole of the drill sleeve frame (203); S4. Lifting the drill body (1) upward, the hydraulic cylinder (201) drives the pressing block (202) to rise, presses the front end (102) of the drill body, and fixes the drill body (1) on the drill sleeve frame (203); S5. Connecting the new processing tool (3) with the coupling (101).

Images