Automatic hole forming method for titanium alloy U-shaped thin-wall cover-shaped structure

Abstract

The invention relates to an automatic hole forming method for a titanium alloy U-shaped thin-wall cover-shaped structure. The problems that manual hole forming is low in efficiency and poor in consistency are solved. Comprising the following steps that 1, a tool is designed to be a stepped drill, and a product is positioned through a positioning hole and the outer surface; 2, a robot assembly auxiliary tool is designed; 3, a laser tracker is used for calibrating a datum point on the to-be-machined molded surface of the robot assembly auxiliary tool; 4, the positioning precision and the repeated positioning precision of the robot assembly auxiliary tool are measured through a laser tracker; step 5, obtaining optimal hole machining parameters; and 6, the system adopts a bus type distributed communication structure, and automatic drilling of the titanium alloy U-shaped thin-wall cover-shaped structure is achieved through coordination of an upper computer. According to the automatic drilling and dimpling integrated machining device, automatic drilling and dimpling integrated machining of the titanium alloy U-shaped thin-wall cover-shaped structure is achieved, the production efficiency and the drilling precision are improved, and the consistency and stability of products are greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial robot application, and in particular relates to an automatic hole making method for a titanium alloy U-shaped thin-walled cover-shaped structure. Background Art

[0002] With the continuous innovation and development of science and technology and industrial technology, industrial production is gradually transforming towards automation and intelligence. The application rate of industrial robots can reflect the technical level of a country's manufacturing industry from the side. For manufacturing companies, the application of industrial robots can improve production efficiency and production accuracy, while reducing a lot of human resource costs. At present, industrial robots have been successfully applied to various industries, especially in automobile production, logistics distribution and other industries. However, in the field of aerospace manufacturing, the degree of automation and intelligence in the manufacturing industry is relatively low, and industrial robots have not been widely used. With the rapid development and breakthroughs in the production of the aviation manufacturing industry, the efficiency of traditional manual assembly is difficult to meet the rhythm of mass production, and the need to use industrial robot assembly instead of traditional manual assembly is imminent.

[0003] In order to solve the problems of difficult manual hole countersinking in titanium alloy plates, large number of holes made with low consistency, low hole quality stability, high manual operation intensity, low production efficiency and high rework and repair rate during the assembly of titanium alloy U-shaped thin-walled hood-shaped structure products, we have carried out research on robot automatic hole making technology to realize the application of assembly robots in automated and high-precision hole making on the surface of titanium alloy U-shaped thin-walled hood-shaped structure parts, which can reduce manual labor intensity, improve the first-time qualified rate of product assembly, ensure high product quality consistency and reliability, and improve overall assembly efficiency. Summary of the invention

[0004] The present invention uses an assembly robot in combination with an automatic hole-making device to fix a titanium alloy U-shaped thin-walled cover-shaped structure (the workpiece) at a specific workstation. After the robot locates the workpiece through a sensor, it controls the rotation of the tool in accordance with the processing procedure to drill a countersunk hole (with a countersink) of a specific size and depth at a specified position of the workpiece.

[0005] Aiming at the problems of low manual processing precision, poor stability, high operation intensity, poor consistency, high rework and low efficiency in the assembly process due to the low manual processing precision and poor stability of holes at specific positions on the surface of titanium alloy sheet metal, which are affected by the skilled operation level and personal skills of the personnel, a robot automatic hole making process method is designed to achieve high-precision hole making and countersinking integrated processing on the surface of titanium alloy U-shaped thin-walled cover-shaped structure. The hole making quality and hole making efficiency under different feed processing amount and different speed conditions of the drill are verified, and a set of processing parameters that achieve the best hole making quality and hole making efficiency are formed, which significantly improves the work efficiency and improves the consistency and stability of the product.

[0006] The present invention is achieved by the following technical solutions:

[0007] A method for automatically making holes in a titanium alloy U-shaped thin-walled cap-shaped structure comprises the following steps:

[0008] Step 1: Determine the tool structure design based on the hole position characteristics of the workpiece to be processed. The tool is designed as a step drill, and the product is positioned through the positioning hole and the outer surface;

[0009] Step 2: According to the shape and structural characteristics of the workpiece, design the robot assembly auxiliary tooling, which includes left and right supporting columns and a rotating body supported thereon, and a driving unit, and the driving unit drives the rotating body to rotate;

[0010] The tooling clamps four quadrant products at the same time, and all hole-making tasks can be completed in one clamping. The workstations are switched by rotation to adapt to the robot's workspace. After the workstations are rotated into place, the reverse clearance of the transmission system is eliminated by the locking device to ensure the hole-making accuracy. The products are clamped and positioned by the positioning cylindrical boss, side positioning surface, bottom positioning surface, pressure block and clamp on the tooling. The positioning cylindrical boss and the product positioning hole are matched, and the side positioning surface, bottom positioning surface and the outer surface of the product are matched to achieve positioning. The pressure block and the clamp realize the clamping of the workpiece.

[0011] Step 3: Use a laser tracker to calibrate the reference points on the surface to be processed by the robot assembly auxiliary tooling to determine the spatial position of the hole to be processed in space;

[0012] Step 4: Use a laser tracker to measure the positioning accuracy and repeatability of the robot assembly auxiliary tooling; according to "General Rules for Machine Tool Inspection Part 2: Determination of Positioning Accuracy and Repeatability of CNC Axis Lines", the tooling positioning accuracy and repeatability accuracy are measured by selecting 9 points at intervals of 30° within the measurable range of tooling rotation, with a positive and negative overtravel of 3° each, to ensure that its accuracy meets the hole making accuracy design requirements.

[0013] Step 5: Set different processing parameters (spindle speed during hole making, countersinking parameters, spindle rapid feed parameters, hole making feed speed, countersinking feed speed) to conduct hole making tests on a 2 mm thick titanium alloy flat plate test piece on the tool test bench to obtain the optimal hole making processing parameters;

[0014] Step 6: The system adopts a bus-type distributed communication structure, and coordinates and controls the robot with the end effector and the robot assembly auxiliary tooling through the upper computer to complete the tooling rotation control, robot positioning, and hole making operations, thereby realizing the automated hole making of the titanium alloy U-shaped thin-walled cover-shaped structure;

[0015] Step 7: Install the titanium alloy U-shaped thin-walled cover structure after drilling to the specified position of the product to verify the accuracy of the hole position and the countersink depth.

[0016] Step drill bit hole making + countersinking integrated processing.

[0017] The step drill processing area is equipped with a vacuum cleaner to clean up debris in real time during the hole making process.

[0018] The optimal hole-making processing parameters are: spindle speed for hole-making 800rpm, spindle countersinking speed 500rpm, spindle feed speed 800rpm, rapid feed speed 35mm / s, hole-making feed speed 0.8mm / s, countersinking feed speed 0.3mm / s.

[0019] The present invention realizes the integrated processing of automatic hole making and countersinking of a titanium alloy U-shaped thin-walled hood-shaped structure, improves production efficiency and hole making accuracy, and greatly improves product consistency and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic diagram of a step drill tool of the present invention;

[0021] FIG. 2 is a schematic diagram of the robot assembly auxiliary tooling of the present invention, wherein Figure 2b yes Figure 2a A top view of Figure 2c yes Figure 2a Side view of. DETAILED DESCRIPTION

[0022] like Figure 1 As shown in Figure 2, the present invention uses a robot assembly auxiliary tooling to press and fix the workpiece, positions the workpiece through the side, bottom and circular holes of the tooling, and presses the workpiece onto a molded surface with positioning accuracy through a pressing block, thereby achieving pressing and positioning of the workpiece; the tooling is designed with a corresponding positioning reference, and a laser tracker can be used for system calibration.

[0023] The teaching mode is adopted, and the processing hole position is calibrated by a laser tracker to improve the positioning accuracy of hole making. The integrated processing of hole making and countersinking is realized by customizing the step drill bit. The countersinking drilling processing area is equipped with a high-suction vacuum cleaner to clean the debris in real time during the hole making process and realize automatic cleaning of excess materials.

[0024] The technical solution of the present invention is further described in detail below with reference to the accompanying drawings.

[0025] Implementation process:

[0026] 1) The tool structure design is determined by the hole position characteristics of the workpiece to be processed (a row of countersunk holes with a spacing of 100 mm at the edge of the cover, and 6 countersunk holes located on the hyperboloid part, with a hole diameter of 5.2). The schematic diagram of the step drill tool is shown in Figure 1 The product is positioned through a 91 Ф positioning hole and the outer surface.

[0027] 2) According to the shape and structural characteristics of the workpiece, the robot assembly auxiliary tooling is designed. The tooling mainly includes left and right supporting columns, rotating body, drive unit and other parts. The schematic diagram of the tooling is shown in Figure 2. The tooling has the following advantages: it can clamp 4 quadrant products at the same time, and all hole-making tasks can be completed in one clamping; the workstation can be switched by rotation to adapt to the robot workspace; after the workstation is rotated into place, the reverse clearance of the transmission system is eliminated by the locking device to ensure the hole-making accuracy; the product is clamped and positioned by the positioning cylindrical boss, side positioning surface, bottom positioning surface, pressure block and clamp on the tooling.

[0028] 3) Complete the production of step drills and robot assembly auxiliary tooling according to design drawings.

[0029] 4) Complete the installation and debugging of robot assembly auxiliary tooling.

[0030] 5) Use a laser tracker to calibrate the reference points on the surface to be processed by the robot assembly auxiliary tooling to determine the spatial position of the hole to be processed in space.

[0031] 6) Use a laser tracker to measure the positioning accuracy and repeatability of robot assembly auxiliary tooling. According to "General Rules for Machine Tool Inspection Part 2: Determination of Positioning Accuracy and Repeatability of CNC Axis", the positioning accuracy and repeatability of tooling are measured by selecting 9 points at intervals of 30° within the measurable range of tooling rotation, with a positive and negative overtravel of 3° each, to ensure that its accuracy meets the hole making accuracy design requirements.

[0032] 7) Set different processing parameters (spindle speed during hole making, countersinking parameters, spindle rapid feed parameters, hole making feed speed, countersinking feed speed) and conduct hole making tests on a 2mm thick titanium alloy flat plate test piece on the tool test bench to obtain the optimal hole making processing parameters.

[0033] 8) The system adopts a bus-type distributed communication structure, and coordinates and controls industrial robots (including end effectors), robot assembly auxiliary tooling and other equipment through the host computer to complete tooling rotation control, robot positioning, hole making and other operations, thereby realizing the automated hole making of titanium alloy U-shaped thin-walled hood-like structures.

[0034] 9) Install the titanium alloy U-shaped thin-walled cover structure after drilling to the specified position of the product to verify the accuracy of the hole position and the countersink depth.

[0035] The present invention is a method for verifying the process parameters of hole making on titanium alloy thin wall by means of industrial robots and robot assembly auxiliary tooling. By integrating the robot assembly auxiliary tooling control system with the robot control system, the efficient, high-precision and high-quality automatic hole making of titanium alloy U-shaped thin-walled hood-shaped structure is realized. Compared with manual hole making, robot automatic hole making has high precision and good quality consistency, which greatly reduces the labor intensity of workers and improves production efficiency. It can be widely used in the automatic hole making process verification of titanium alloy U-shaped thin-walled hood-shaped structure.

Claims

1. A titanium alloy U-shaped thin-walled cover-shaped structure automatic hole making method, characterized by: The following steps are involved: Step 1: Determine the tool structure design based on the hole position characteristics of the workpiece to be processed. The tool is designed as a step drill, and the product is positioned through the positioning hole and the outer surface; Step 2: According to the shape and structural characteristics of the workpiece, design the robot assembly auxiliary tooling, which includes left and right supporting columns and a rotating body supported thereon, and a driving unit, and the driving unit drives the rotating body to rotate; The tooling clamps four quadrant products at the same time, and all hole-making tasks can be completed in one clamping. The workstations are switched by rotation to adapt to the robot's workspace. After the workstations are rotated into place, the reverse clearance of the transmission system is eliminated by the locking device to ensure the hole-making accuracy. The products are clamped and positioned by the positioning cylindrical boss, side positioning surface, bottom positioning surface, pressure block and clamp on the tooling. The positioning cylindrical boss cooperates with the product positioning hole, the side positioning surface, bottom positioning surface and the outer surface of the product cooperate to achieve positioning, and the pressure block and the clamp realize the clamping of the workpiece. Step 3: Use a laser tracker to calibrate the reference points on the surface to be processed by the robot assembly auxiliary tooling to determine the spatial position of the hole to be processed in space; Step 4: Use a laser tracker to measure the positioning accuracy and repeatability of the robot assembly auxiliary tooling to ensure that its accuracy meets the hole making accuracy design requirements; Step 5: Set different processing parameters to conduct hole making tests on a 2 mm thick titanium alloy flat plate test piece on the test tool bench to obtain the optimal hole making processing parameters; Step 6: The system adopts a bus-type distributed communication structure, and coordinates and controls the robot with the end effector and the robot assembly auxiliary tooling through the upper computer to complete the tooling rotation control, robot positioning, and hole making operations, thereby realizing the automated hole making of the titanium alloy U-shaped thin-walled hood-shaped structure.

2. The method for automatically making holes in a titanium alloy U-shaped thin-walled cap-shaped structure according to claim 1 is characterized by: Install the titanium alloy U-shaped thin-walled cover-shaped structure after drilling to the specified position of the product to verify the accuracy of the hole position and the countersink depth.

3. The method for automatically making holes in a titanium alloy U-shaped thin-walled cap-shaped structure according to claim 1 is characterized by: Step drill bit hole making + countersinking integrated processing.

4. The method for automatically making holes in a titanium alloy U-shaped thin-walled cap-shaped structure according to claim 1 is characterized by: The step drill processing area is equipped with a vacuum cleaner to clean up debris in real time during the hole making process.

5. The method for automatically making holes in a titanium alloy U-shaped thin-walled cap-shaped structure according to claim 1 is characterized by: The optimal hole-making processing parameters are: spindle speed for hole-making 800rpm, spindle countersinking speed 500rpm, spindle feed speed 800rpm, rapid feed speed 35mm / s, hole-making feed speed 0.8mm / s, countersinking feed speed 0.3mm / s.

6. The method for automatically making holes in a titanium alloy U-shaped thin-walled cap-shaped structure according to claim 1 is characterized by: In step 4, the positioning accuracy and repeatability of the tooling are measured by selecting 9 points at intervals of 30° within the measurable range of tooling rotation, with a positive and negative overtravel of 3° each, to ensure that its accuracy meets the hole making accuracy design requirements.

7. The method for automatically making holes in a titanium alloy U-shaped thin-walled cap-shaped structure according to claim 1 is characterized by: In step 5, the processing parameters set include the spindle rotation speed during hole making, countersinking parameters, spindle rapid feed parameters, hole making feed speed and countersinking feed speed.

Images