An adjustable analog eccentricity fixture and method thereof

Abstract

The present application belongs to the field of aerospace hole machining technology, and proposes an adjustable simulation eccentricity tooling, including a base plate, an expanded reaming drill fixing module, an experimental part installation module and a workpiece hole position positioning pin. The expanded reaming drill fixing module includes a drill template and an expanded reaming drill puller, which is used to connect the expanded reaming drill sleeve; the experimental part installation module includes an experimental part, an experimental installation plate, an experimental part pressing groove, a rubber gasket, an experimental part mounting seat, a fastening bolt and a fastening bolt pad, which can realize the change of eccentricity in a predetermined range; the workpiece hole position positioning pin includes a positioning pin fixed end and a positioning pin replaceable end, which is used to adjust the specific eccentricity of the experimental part and the cutter. The present application realizes the simulation tooling of the actual site eccentric machining condition in the laboratory, especially the simulation tooling of the expanded hole and the reaming hole, analyzes the influence of each cutting parameter on the hole quality under different eccentricity values and directions, and then reasonably optimizes the different eccentricity, so as to improve the quality and efficiency of the expanded hole and the reaming hole under the actual eccentric machining condition.

Description

Technical Field

[0001] This invention belongs to the field of aerospace hole-making and machining, specifically relating to an adjustable simulated eccentricity tooling and its method. Background Technology

[0002] Lightweight, high-strength carbon fiber reinforced resin (CFRP) composites and metal materials resistant to alternating loads (such as titanium alloys and aluminum alloys) are preferred for weight reduction and efficiency improvement in high-end aerospace equipment. To ensure highly reliable assembly and high-performance operation of CFRP and its laminated structures with metal materials, tens of thousands of various types of connection holes must be machined efficiently. In the hole-making process of aerospace equipment, reaming and boring are crucial procedures. Reaming involves using a reamer to further process drilled, cast, or forged holes to enlarge the hole diameter and improve the hole's machining quality. Boring involves finishing the reamed workpiece to meet requirements for hole diameter accuracy, coaxiality, and hole wall quality. The quality of boring determines the final quality of the hole and its usability.

[0003] However, in actual machining operations, situations often arise where the tooling fixture is misaligned with the hole to be enlarged or reamed due to limitations in machining space or errors in the shape and size of the parts. In such cases, ensuring the hole's machining quality meets design requirements increases machining difficulty and decreases machining efficiency. Therefore, to save time and costs, it is necessary to simulate and test actual misalignment conditions. By comparing the hole diameter accuracy and coaxiality under different cutting parameters under various misalignment conditions, the impact of each factor on hole quality can be analyzed and optimized, thereby improving the quality and efficiency of hole enlargement and reaming under actual misalignment machining conditions. Therefore, to meet the testing requirements for different misalignment directions and amounts, a tooling device capable of simulating actual misalignment machining conditions needs to be developed.

[0004] Su Meiyu et al. of Changzhou Jiding Machinery Technology Co., Ltd. disclosed an eccentric tooling for boring irregularly shaped parts, patent number CN 116237557 A. This eccentric tooling is used for boring a specific type of irregularly shaped part and is easy to assemble and disassemble. However, it is only applicable to specific eccentric parts; different specially made fixtures are required for machining parts with different eccentric amounts, which has certain limitations.

[0005] In summary, in order to meet the requirements of simulated machining with different eccentric directions and eccentricities, it is necessary to design a set of fixtures and tooling suitable for composite materials and metal materials, which can adjust the test conditions according to actual working conditions for hole reaming and boring. Summary of the Invention

[0006] In order to analyze the influence of cutting parameters on machining quality under different eccentric directions and values, this invention proposes an adjustable simulation eccentricity tooling.

[0007] The technical solution of this invention:

[0008] An adjustable simulation eccentricity fixture includes a base plate 1, a reaming drill fixing module 2, a test piece mounting module 3, and a workpiece hole positioning pin 4, wherein:

[0009] The reaming drill fixing module 2 includes a drill template 201 and a reaming drill rivet 202; the reaming drill rivet 202 is installed on the drill template 201, and the drill template 201 is installed on the base plate 1;

[0010] The experimental component mounting module 3 includes an experimental component 301, an experimental mounting plate 302, an experimental component clamping groove 303, a rubber gasket 304, an experimental component mounting base 305, fastening bolts 306, and fastening bolt washers 307. The experimental component 301 is a sleeve structure with a flange at one end, the experimental component mounting base 305 is a semi-circular arc structure with a flange, and the experimental component clamping groove 303 is a fixing plate with a semi-circular arc structure. The experimental component 301 is mounted on the experimental component mounting base 305, the outer circular surface of the experimental component 301 mates with the semi-circular arc surface of the experimental component mounting base 305, and the flange surface of the experimental component 301 mates with one side of the flange of the experimental component 305. The rubber gasket 304 and the test piece clamping groove 303 are installed on the test piece mounting base 305 by fastening bolts 306. The test piece 301 is fixed by the semi-circular arc surface of the test piece clamping groove 303 fitting against the test piece 301. The workpiece hole positioning pin 4 includes a positioning pin fixed end 401 and a positioning pin replaceable assembly 402. The front end of the positioning pin fixed end 401 and the positioning pin replaceable assembly 402 are connected by fasteners. The front conical surface of the positioning pin replaceable assembly 402 fits with the inner hole of the test piece 301. The end of the positioning pin fixed end 401 is rotated so that the notch on the outer circular surface of the positioning pin replaceable assembly 402 is aligned with the eccentric direction required for the experiment.

[0011] An adjustable simulation eccentricity tooling method includes the following steps;

[0012] Step 1: Install the drill template 201 onto the base plate 1;

[0013] Step 2: Install the rubber gasket 304 and the test piece clamping groove 303 onto the test piece mounting base 305 using fastening bolts 306;

[0014] Step 3: Use fastening bolts 306 to install the fastening bolt washer 307 and the test piece mounting base 305 onto the test mounting plate 302;

[0015] Step 4: Install the experimental mounting plate 302 on the base plate 1; insert the experimental piece 301 into the circular hole between the experimental piece mounting base 305 and the semi-circular structure on the experimental piece clamping groove 303 so that the experimental piece 301 and the experimental piece mounting base 305 fit tightly together; tighten the four fastening bolts 306 installed on the experimental piece clamping groove 303 to clamp the experimental piece 301.

[0016] Step 5: Select the corresponding locating pin interchangeable assembly 402 part for the experiment, and connect it to the locating pin fixed end 401 using bolts; insert the locating pin fixed end 401 into the guide hole of the rear drill template 201, so that its cylindrical surface mates with the guide hole, and the front conical surface of the locating pin interchangeable assembly 402 mates with the inner hole of the experimental piece 301; rotate the end of the locating pin fixed end 401 so that the notch on the outer circular surface of the locating pin interchangeable assembly 402 faces vertically downward;

[0017] Step 6: Tighten the four fastening bolts 306 on the fastening bolt pad 307 to fix the position of the test piece 301; and pull out the positioning pin fixing end 401 from the rear.

[0018] Furthermore, when installing the workpiece hole positioning pin 4, the cylindrical surface of the positioning pin fixing end 401 mates with the inner hole of the drilling template 201; the stepped hole at the front end of the positioning pin fixing end 401 mates with the cylindrical boss at the end of the positioning pin interchangeable assembly 402; and the conical surface at the front end of the positioning pin interchangeable assembly 402 mates with the rear edge of the hole in the test piece 301.

[0019] Furthermore, the locating pin interchangeable group 402 is a set of parts with a hollow conical surface at the front end and a cylindrical boss at the end. The offset of the conical surface and the cylindrical surface axis of each part is different. The corresponding part in the locating pin interchangeable group 402 is selected according to the simulation requirements of the eccentricity in different experiments. The outer surface of the locating pin interchangeable group 402 is marked in the eccentric direction.

[0020] Furthermore, the inner diameter of the through hole of the experimental mounting plate 302 is greater than the outer diameter of its fastener plus the maximum experimental eccentricity, and the experimental mounting base 305 can move within this range.

[0021] Furthermore, six installation positions are evenly distributed around the guide hole of the drill template 201; the reaming drill pull stud 202 is installed on the drill template at a 180-degree phase and can be locked with the flange groove at the front end of the drill sleeve. The reaming drill pull stud 202 can be installed in two horizontal holes a among the above six installation positions, which corresponds to the machining posture of the reaming drill at 0° relative to the tooling installation plane in the circumferential direction; the reaming drill pull stud 202 can be installed in hole b by rotating 60° clockwise in the horizontal direction or in hole c by rotating 60° counterclockwise in the horizontal direction, which respectively correspond to the machining posture of the reaming drill at -60° and 60° relative to the tooling installation plane in the circumferential direction.

[0022] The beneficial effects of this invention are as follows: By replacing the positioning pins, this invention can simultaneously adjust both the eccentricity and the eccentricity direction, making the fixture more universally applicable to actual eccentric working conditions; the operation is simple and convenient, each time the eccentricity is adjusted, only the test piece needs to be extracted and replaced, and repositioned and clamped, without disassembling the entire fixture; this adjustable simulated eccentricity fixture can simulate the machining quality under actual eccentric machining conditions in the laboratory, and then reasonably optimize for different eccentricities, improving the quality and efficiency of reaming holes under actual eccentric machining conditions. Attached Figure Description

[0023] Figure 1 This is the overall structural diagram of the eccentricity tooling used in this simulation.

[0024] Figure 2 This is an exploded view of the eccentric tooling used in this simulation.

[0025] Figure 3 This is a cross-sectional view of the tooling used to simulate eccentricity.

[0026] Figure 4 This diagram shows the mate of the eccentric tooling with the reamer during machining.

[0027] Figure 5 The diagram shows three installation positions of the reamer pull stud; (a) the reamer pull stud is installed in the horizontal position of the drilling template, (b) the reamer pull stud is installed in the position where the drilling template is rotated 60° clockwise in the horizontal direction, and (c) the reamer pull stud is installed in the position where the drilling template is rotated 60° counterclockwise in the horizontal direction.

[0028] In the diagram: 1-base plate, 2-reaming drill fixing module, 201-drill template, 202-reaming drill pull stud, 3-experimental piece mounting module, 301-experimental piece, 302-experimental mounting plate, 303-experimental piece clamping groove, 304-rubber gasket, 305-experimental piece mounting base, 306-fastening bolt, 307-fastening bolt washer, 4-workpiece hole positioning pin, 401-positioning pin fixing end, 402-positioning pin interchangeable set. Detailed Implementation

[0029] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0030] Example

[0031] See Figure 1 and Figure 2This is an adjustable eccentricity simulation fixture, mainly composed of a base plate 1, a reaming drill fixing module 2, an experimental piece mounting module 3, and workpiece hole positioning pins 4. The base plate 1 is the fixture's supporting part, responsible for installing and connecting the other modules. The reaming drill fixing module 2 includes a drill template 201 and reaming drill pull studs 202. The drill template 201 has six threaded holes evenly distributed around its guide hole for installing the reaming drill pull studs 202. The reaming drill pull studs 202 are installed in a 180-degree phase, with three installation positions to simulate the influence of different axial constraints on machining. By analyzing the influence of different reaming drill pull stud 202 arrangement positions on the quality of the reamed hole, the optimal arrangement method for actual machining is selected. The experimental piece mounting module 3 includes an experimental piece 301... The experimental mounting plate 302, experimental piece clamping groove 303, rubber gasket 304, experimental piece mounting base 305, fastening bolt 306, and fastening bolt washer 307 are included. The experimental mounting plate 302 is fixed to the base plate 1 by bolts. The experimental piece 301 is an annular workpiece with a groove and flange on its cylindrical surface, simulating the workpiece to be expanded and reamed in actual machining. The outer diameter of the experimental piece 301 is smaller than the inner diameter of the guide hole of the drill template 201, allowing the experimental piece to be removed and replaced from the rear guide hole. The cylindrical surface of the experimental piece 301 mates with the semi-cylindrical surface of the experimental piece mounting base 305 to ensure the experimental piece clamping groove is properly clamped. The coaxiality of test piece 301 and test piece mounting base 305; the flange face of test piece 301 mates with the stepped surface on test piece mounting base 305 to prevent axial movement during reaming; four threaded holes are arranged on both sides of the semi-circular surface of test piece mounting base 305, and four corresponding through holes are on the test piece clamping groove 303; fastening bolts 306 clamp the test piece clamping groove 303 and the test mounting plate 302, and a rubber gasket 304 is placed between the test piece clamping groove 302 and the test piece mounting base 305 to achieve fastening of test piece 301; the test piece mounting base 305 is... The flange has four threaded holes. The fastening bolt 306 is screwed into the threaded hole of the test piece mounting base 305 through the through holes on the fastening bolt washer 307 and the test mounting plate 302, thus fixing the test piece mounting base 305 to the test mounting plate 302 and fixing the position of the test piece 301. The inner diameter of the through hole on the test mounting plate 302 connecting to the test piece mounting base 305 is slightly larger than the outer diameter of the bolt plus the maximum experimental eccentricity, allowing the fastening bolt 306 to move axially within the through hole, thereby adjusting the eccentric position of the test piece 301 relative to the drill template 201. (Reference) Figure 3The workpiece hole positioning pin 4 consists of a fixed positioning pin end 401 and a replaceable positioning pin assembly 402. The fixed positioning pin end 401 is a cylindrical guide rod with a threaded hole at the front end. The fit accuracy between its cylindrical surface and the guide hole of the drill template 201 is the same as the fit accuracy between the drill bushing and the drill template 201 during machining, simulating the axial position of the tool during actual machining. The front end of the fixed positioning pin end 401 and the replaceable positioning pin assembly 402 are connected by a cylindrical surface fit and bolts. The replaceable positioning pin assembly 402 is a set of parts with a conical front end and a cylindrical rear end, containing two through holes. Its conical front end and cylindrical rear end are arranged relatively eccentrically, with eccentricity amounts of 0mm, 0.1mm, 0.2mm... up to 1.0mm. The replaceable positioning pin assembly 402 has a notch designed on its outer circular surface along the eccentric direction to determine and adjust the relative eccentricity direction between the experimental workpiece 301 and the drill template 201. In the simulated eccentricity laboratory, different eccentricity amounts can be adjusted by changing different locating pins in group 402.

[0032] The following example illustrates the tooling used in this embodiment, taking the machining process with an eccentricity of 0.4mm and the eccentricity direction being the direction of gravity as an example:

[0033] (1) Install the expanding drill rivet 202 on the drill template 201, and install the drill template 201 on the corresponding installation position of the base plate 1 with bolts;

[0034] (2) Place the rubber pad 304 on the two platforms of the semi-cylindrical surface of the test piece mounting base 305, and press the test piece clamping groove 303 on the rubber pad. Connect the test piece clamping groove 303 and the test piece mounting base 305 with the fastening bolt 306, and ensure that there is a certain gap between the test piece mounting base 305 and the test piece clamping groove 303, allowing the test piece 301 to be inserted from the rear end.

[0035] (3) Arrange the fastening bolt pad 307 and the test piece mounting base 305 on both sides of the test mounting plate 302, and connect the three with fastening bolts 306 to ensure that the test mounting plate 302 can move on the test piece mounting base 305 without slipping.

[0036] (4) Install the experimental mounting plate 302 on the corresponding mounting position of the base plate 1 with bolts;

[0037] (5) Insert the test piece 301 into the round hole between the test piece mounting base 305 and the test piece clamping groove 303 through the guide hole of the template 201 from the rear; fit the cylindrical surface of the test piece 301 with the semi-cylindrical surface of the test piece mounting 305, and fit the flange surface of the test piece 301 with the stepped surface of the test piece mounting base 305; tighten the four fastening bolts 306 installed on the test piece clamping groove 303 to clamp the test piece 301.

[0038] (6) Select the locating pin replacement group 402 corresponding to the eccentric value of 0.4mm, and use bolts to connect it to the locating pin fixing end 401;

[0039] (7) Insert the fixed end 401 of the positioning pin into the guide hole of the rear drill template 201 so that its cylindrical surface matches the guide hole and its front conical surface matches the inner hole of the test piece 301; rotate the handle at the end of the fixed end 401 so that the notch on the outer circular surface of the positioning pin interchangeable group 402 faces vertically downward.

[0040] (8) Tighten the four fastening bolts 306 on the fastening bolt washer 307 to fix the position of the test piece 301.

[0041] (9) Pull out the fixing end 401 of the positioning pin from the rear;

[0042] (10) Insert the reamer sleeve into the guide hole of the drill template 201, rotate the reamer sleeve to fix it to the reamer pull stud 202;

[0043] (11) Perform hole enlargement processing;

[0044] The above is a simulation of the eccentricity tooling machining process. Subsequently, the layout of the reamer pull stud 202 can be changed according to experimental needs, the drilling machining parameters can be improved, or the eccentricity of the experimental piece 301 can be changed to conduct multiple experimental tests, analyze the data, and then obtain the corresponding optimal cutting parameters and reamer pull stud layout under different eccentric working conditions, saving on-site machining time and costs.

Claims

1. An adjustable simulated eccentricity tooling, characterized in that, The adjustable simulation eccentricity fixture includes a base plate (1), a reamer fixing module (2), a test piece mounting module (3), and a workpiece hole positioning pin (4), wherein: The reaming drill fixing module (2) includes a drill template (201) and a reaming drill rivet (202); the reaming drill rivet (202) is installed on the drill template (201), and the drill template (201) is installed on the base plate (1); The experimental component mounting module (3) includes an experimental component (301), an experimental mounting plate (302), an experimental component clamping groove (303), a rubber gasket (304), an experimental component mounting base (305), fastening bolts (306), and fastening bolt washers (307). The experimental component (301) is a sleeve structure with a flange at one end, the experimental component mounting base (305) is a semi-circular arc structure with a flange, and the experimental component clamping groove (303) is a fixing plate with a semi-circular arc structure. The experimental component (301) is mounted on the experimental component mounting base (305), the outer circular surface of the experimental component (301) matches the semi-circular arc surface of the experimental component mounting base (305), and the flange surface of the experimental component (301) matches one side of the flange of the experimental component (305). The rubber gasket (304) and the test piece clamping groove (303) are installed on the test piece mounting base (305) by fastening bolts (306). The test piece (301) is fixed by the semi-circular arc surface of the test piece clamping groove (303) fitting against the test piece (301). The workpiece hole positioning pin (4) includes a positioning pin fixed end (401) and a positioning pin replaceable assembly (402). The front end of the positioning pin fixed end (401) and the positioning pin replaceable assembly (402) are connected by fasteners. The front conical surface of the positioning pin replaceable assembly (402) fits with the inner hole of the test piece (301). The end of the positioning pin fixed end (401) is rotated so that the notch on the outer circular surface of the positioning pin replaceable assembly (402) is consistent with the eccentric direction required for the experiment. The replaceable positioning pin assembly (402) is a set of parts with a hollow conical surface at the front end and a cylindrical boss at the end. The offset between the conical surface and the cylindrical surface axis of each part is different. The corresponding part in the replaceable positioning pin assembly (402) is selected according to the simulation requirements of the eccentricity in different experiments. The outer surface of the replaceable positioning pin assembly (402) is marked in the eccentricity direction. The inner diameter of the through hole of the experimental mounting plate (302) is greater than the sum of the outer diameter of its fastener and the maximum experimental eccentricity, and the experimental mounting base (305) moves within its range; Six installation positions are evenly distributed around the guide hole of the drill template (201); the reaming drill pull stud (202) is installed on the drill template (201) at a 180-degree phase and locked with the flange groove at the front end of the drill sleeve; the reaming drill pull stud (202) is installed in two horizontal holes (a) among the above six installation positions, which corresponds to the reaming drill's machining posture when it is 0° relative to the tooling installation plane in the circumferential direction; the reaming drill pull stud (202) is installed in hole (b) by rotating it 60° clockwise in the horizontal direction or in hole (c) by rotating it 60° counterclockwise in the horizontal direction, which corresponds to the reaming drill's machining posture when it is -60° and 60° relative to the tooling installation plane in the circumferential direction, respectively; when the reaming drill pull stud (202) is arranged in the three positions of upper right-lower left hole (a), upper left-lower right hole (b) and horizontal hole (c), it corresponds to the reaming drill's machining posture when it is -60°, -120° and 0° relative to the tooling installation plane in the circumferential direction, respectively.

2. A method of using the adjustable simulated eccentricity tooling as described in claim 1, characterized in that, The steps include the following: Step 1: Install the drilling template (201) onto the base plate (1); Step 2: Install the rubber gasket (304) and the test piece clamping groove (303) onto the test piece mounting base (305) using fastening bolts (306); Step 3: Use fastening bolts (306) to install the fastening bolt washer (307) and the test piece mounting base (305) onto the test mounting plate (302); Step 4: Install the experimental mounting plate (302) on the base plate (1); insert the experimental piece (301) into the circular hole between the semi-circular arc structure on the experimental piece mounting base (305) and the experimental piece clamping groove (303) so that the experimental piece (301) and the experimental piece mounting base (305) fit tightly together; tighten the four fastening bolts (306) installed on the experimental piece clamping groove (303) to clamp the experimental piece (301); Step 5: Select the corresponding locating pin interchangeable assembly (402) part for the experiment and connect it to the locating pin fixed end (401) with bolts; insert the locating pin fixed end (401) along the guide hole of the rear drilling template (201) so that its cylindrical surface fits with the guide hole, and the front conical surface of the locating pin interchangeable assembly (402) fits with the inner hole of the experimental piece (301); rotate the end of the locating pin fixed end (401) so that the notch on the outer circular surface of the locating pin interchangeable assembly (402) faces vertically downward; Step 6: Tighten the four fastening bolts (306) on the fastening bolt pad (307) to fix the position of the test piece (301); and pull out the positioning pin fixing end (401) from the rear.

3. The method of use according to claim 2, characterized in that, When installing the workpiece hole positioning pin (4), the cylindrical surface of the fixed end (401) of the positioning pin engages with the inner hole of the drill template (201); the stepped hole at the front end of the fixed end (401) of the positioning pin engages with the cylindrical boss at the end of the replaceable assembly (402) of the positioning pin; and the conical surface at the front end of the replaceable assembly (402) of the positioning pin engages with the rear edge of the hole in the test piece (301).

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