A high-speed orthogonal cutting experimental device and experimental method based on secondary impact technology

Abstract

The present invention discloses a high-speed orthogonal cutting experimental device and experimental method based on secondary impact technology, comprising a power system, a launching mechanism, a cutting mechanism and a high-speed camera; the launching mechanism and the cutting mechanism are coaxially arranged; the launching mechanism comprises a launching tube, a base and a guide rail fixedly connected in sequence; a guide rod is installed on the guide rail, and a workpiece to be processed is fixed on the guide rod; the cutting mechanism comprises two symmetrically arranged cutting parts, the cutting part comprises a tool clamp, a tool, a force sensor and a slide; the tool is installed on the tool clamp, the tool clamp and the force sensor, and the force sensor is installed on the slide; the power system is used to provide kinetic energy for the guide rod in the launching mechanism, the guide rod and the workpiece to be processed are fixed to drive the workpiece to be processed to move, and the guide rod is installed at the exit position of the launching tube. When cutting, the workpiece only needs to move from the exit of the launching tube to the tool, and does not need to move in the launching tube, thereby avoiding the trajectory uncertainty caused by the movement of the workpiece in the long launching tube.

Description

Technical Field

[0001] The invention belongs to the technical field of high-speed cutting processing, and in particular relates to a high-speed orthogonal cutting experimental device and an experimental method based on a secondary impact technology. Background Art

[0002] High-speed cutting technology has been widely favored and applied in the field of mechanical processing due to its high material removal rate, low cutting force, and high surface quality. It is the development direction of the metal cutting industry. However, during high-speed cutting, the workpiece material is subjected to strong impact from the tool, resulting in an extremely high strain rate, which causes the material deformation process to change significantly compared to conventional cutting speeds. The most obvious feature is that the chip morphology changes from continuous to serrated and even fragmented. At this time, the internal structure and properties of the material change significantly, resulting in changes in the macroscopic mechanical state. The traditional shear slip theory cannot provide a thorough explanation for the above phenomenon. Therefore, it is urgent to deeply understand the material change process and propose a new mechanism to supplement the traditional mechanism, so as to lay a solid theoretical foundation for the subsequent guidance of high-speed cutting tool design, optimization of high-speed cutting processing technology, and improvement of machine tool efficiency.

[0003] The limitations of existing machine tool structures and speeds have hindered research into the mechanisms of high-speed cutting. High-speed cutting is characterized by extremely high speeds and high risk factors. Even slight errors in the device and cutting process can have incalculable consequences, placing high demands on the accuracy of the interaction between the tool and the workpiece, the precision of cutting parameter settings, and the safety of the equipment. Currently, in the field of high-speed cutting research, most approaches utilize the principles of light gas guns and Hopkinson pressure bars to achieve high-speed cutting. By accelerating one of the tool or workpiece while holding the other fixed, the workpiece and tool collide and squeeze to complete the cutting process. However, the launch tubes used in existing devices to accelerate the workpiece or tool are relatively long, making the manufacturing accuracy of the launch tubes difficult to guarantee. Furthermore, there are uncertainties in the movement of the tool or workpiece in the launch tube, making it difficult to guarantee the trajectory of the workpiece or tool. Summary of the Invention

[0004] In order to overcome the defects of the prior art, the present invention provides a high-speed orthogonal cutting experimental device based on secondary impact technology, which reduces the trajectory uncertainty caused by the movement of the workpiece in the launch tube in the high-speed cutting device.

[0005] To achieve the above-mentioned purpose, the present invention discloses a high-speed orthogonal cutting experimental device based on secondary impact technology, comprising a power system, a launching mechanism, a cutting mechanism and a high-speed camera; the launching mechanism and the cutting mechanism are coaxially arranged; the power system comprises an air box and a bullet, and the bullet is used to provide power for the guide rod; the launching mechanism comprises a launching tube, a base and a guide rail fixedly connected in sequence; an installation groove is provided on the guide rail, and a guide rod is installed in the installation groove, and the guide rod is used to fix the workpiece to be processed; the cutting mechanism comprises two symmetrically arranged cutting parts, and the cutting part comprises a tool clamp, a tool, a force sensor and a slide; the tool is installed on the tool clamp, the tool clamp and the force sensor, and the force sensor is installed on the slide; the high-speed camera is used to capture images of the entire cutting process.

[0006] Furthermore, the mounting groove is a square groove.

[0007] Furthermore, the end of the guide rod is wedge-shaped.

[0008] Furthermore, the weight of the guide rod is equal to the weight of the bullet.

[0009] Furthermore, the slide is a three-way adjustable slide.

[0010] Furthermore, a chip collecting groove is provided on the side of the cutting mechanism.

[0011] Furthermore, a recovery box is provided outside the cutting mechanism, and the recovery box is filled with buffer material.

[0012] Furthermore, the frequency of the force sensor is greater than 1 MHz.

[0013] Furthermore, it also includes a thermal imager, which is used to collect cutting thermal images.

[0014] A high-speed orthogonal cutting experimental method based on secondary impact technology, based on the above-mentioned experimental device, is characterized by comprising the following steps:

[0015] Step 1: Fix the workpiece to be processed to the guide rod;

[0016] Step 2: Adjust the X-axis position of the slide so that the tool is close to the workpiece to be processed. Adjust the Z-axis position of the slide so that the thickness of the workpiece to be processed is completely within the range of the tool cutting edge length. At the same time, adjust the Y-axis and X-axis positions of the slide so that the outer side of the tool cutting edge contacts the workpiece to be processed, completing the tool setting. By adjusting the X-axis position of the slide, the tool is retracted to the set position.

[0017] Step 3: Move the slide in the Y direction toward the workpiece until the cutting depth is equal to the set value;

[0018] Step 4: Place the bullet at the entrance of the launch tube, adjust the air pressure in the air box, open the air valve, and trigger the force sensor and high-speed camera at the same time. The bullet accelerates along the launch tube and acts on the guide rod when it reaches the exit of the launch tube. The guide rod carries the workpiece along the guide rail and contacts the tool on the right to complete the cutting.

[0019] Step 5: Obtain chips and processed workpieces, obtain cutting force data through a force sensor, observe the cutting process through a high-speed camera and obtain cutting speed data of the cutting process.

[0020] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0021] The device described in the present invention includes a power system, a launching mechanism and a cutting mechanism. The power system is used to provide kinetic energy for the guide rod in the launching mechanism. The guide rod is fixed to the workpiece to be processed, driving the workpiece to be processed to move. The guide rod is installed at the exit position of the launching tube. During cutting, the workpiece only needs to move from the exit of the launching tube to the tool without moving in the launching tube, avoiding the uncertainty of the trajectory caused by the movement of the workpiece in the long launching tube, allowing the workpiece to move according to the preset trajectory, improving cutting accuracy, and ensuring the safety of the experimental device and the operator.

[0022] Furthermore, the square groove inside the guide rail prevents the guide rod from deflecting when moving along the guide rail, and the guide rod that clamps the workpiece and the guide rail of the launch port have a high-precision fit, ensuring the correct initial cutting posture of the workpiece and the tool;

[0023] Furthermore, the guide rod is made of 7075 aluminum alloy, which is light in weight and has good rigidity. It has a high energy conversion efficiency when colliding with a bullet. The end is wedge-shaped to avoid serious deformation of the guide rod end due to excessive impact force of the bullet collision, which prevents the guide rod from flying out along the guide rail.

[0024] Furthermore, the total length of the guide rod is 105 mm, and the mass of the guide rod is the same as the mass of the bullet, so that the energy of the bullet can be converted to the guide rod as fully as possible; the cutting speed can be changed by changing the length of the guide rod relative to the guide rail, that is, changing the acceleration time or changing the air pressure value of the power system.

[0025] Furthermore, the cutting part uses a three-way adjustable slide to adjust the cutting parameters. The slide is adjustable in three directions with an accuracy of up to 0.02mm and is self-locking, which effectively improves the flexibility of the device adjustment and processing accuracy, and reduces safety hazards.

[0026] Furthermore, a chip collection tank is provided to collect the chips generated in the experiment for subsequent analysis and research on the high-speed cutting mechanism;

[0027] Furthermore, high-frequency force sensors can be used to collect cutting force information during the cutting process; high-speed cameras and thermal imagers are placed directly above the cutting mechanism, which can not only obtain the cutting speed and cutting temperature at any time during the cutting process, but also observe the entire cutting process.

[0028] Furthermore, the recycling box is filled with a large amount of buffer material to protect the processed workpiece.

[0029] Furthermore, the present invention uses a high-speed camera to shoot the cutting process, and calculates the cutting speed according to the scale length and the number of frames, so that the cutting process video and the cutting speed can be obtained at the same time.

[0030] The test method described in the present invention places a workpiece to be processed at the outlet of a launch tube. After the bullet is accelerated along the launch tube, it collides with a guide rod that clamps the workpiece to perform energy conversion, converting the speed of the bullet into the speed of the workpiece. The workpiece only needs to move from the outlet of the launch tube to the tool without moving in the launch tube, thereby avoiding the uncertainty of the trajectory of the workpiece caused by the movement of the long launch tube, allowing the workpiece to move according to a preset trajectory, improving cutting accuracy, and ensuring the safety of the experimental device and the operator. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A top view of the structure of the present invention;

[0032] Figure 2 This is a schematic diagram of the transmitter separation structure of the present invention;

[0033] Figure 3 This is the X-direction view of the cutting mechanism of the present invention.

[0034] In the figure: 1. Launch tube, 2. Base, 3. Guide rail, 31. Mounting slot, 4. Guide rod, 5. Workpiece to be processed, 6. Chip collection groove, 7. Tool clip, 8. Tool, 9. Force sensor, 10. Three-way adjustable slide, 11. Slide base, 12. Recovery box, 31. Square slot. DETAILED DESCRIPTION

[0035] In order to make the purpose and technical solution of the present invention clearer and easier to understand, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0037] Reference Figure 1 and Figure 3 The present invention discloses a high-precision, high-speed cutting experimental device based on secondary impact technology. The device includes a power system, a launching mechanism, a cutting mechanism, a recovery mechanism, a high-speed camera, and a thermal imager. The launching mechanism, driven by power, launches the workpiece at a predetermined speed. The cutting mechanism adjusts cutting parameters and completes the cutting process. The recovery mechanism recovers the workpiece after cutting. The high-speed camera and thermal imager record the entire cutting process and measure cutting speed and temperature. The positioning and interaction between the tool and workpiece in the device enable orthogonal cutting.

[0038] The power system (not shown) includes an air box and bullets.

[0039] Reference Figure 2 The launching mechanism includes a launching tube 1, a base 2, a guide rail 3, and a guide rod 4. The cutting mechanism includes a chip collection groove 6, a tool holder 7, a tool 8, a force sensor 9, a three-way adjustable slide 10, and a slide base 11. The recovery mechanism includes a recovery box 12 with built-in buffer material. The launching mechanism, cutting mechanism, and recovery mechanism are arranged in sequence along the same axis.

[0040] The inlet of the launch tube 1 is connected to the air box via a pipe equipped with an air valve. A bullet is placed at the inlet of the launch tube 1, and the corresponding power system air pressure is adjusted according to the required cutting speed. Driven by the air pressure, the bullet is accelerated along the launch tube 1. A base 2 is used to secure a guide rail 3, which is installed at the outlet of the launch tube 1. The guide rail 3 and base 2 are connected by screws, and the workpiece 5 to be processed is connected to the guide rod 4 by bolts. The guide rod 4 and the guide rail 3 have a clearance fit with a maximum clearance value of 0.03, allowing relative motion. After the bullet is fired, it is accelerated to the guide rod 4, and the guide rod 4 accelerates along the guide rail 3. The masses of the bullet and guide rod 4 are equal, ensuring sufficient kinetic energy conversion. A square mounting groove 31 is provided in the center of the guide rail 3 to limit deflection of the guide rod 4 during movement, ensuring that the workpiece 5 to be processed and the tool 8 are in the correct cutting position when contacting. The end of the guide rod 4 is wedge-shaped to effectively prevent severe deformation of the tail after impact with the bullet, preventing it from smoothly flying along the guide rail 3. The horizontal distance between the end face of the guide rail 3 close to the cutting mechanism and the plane where the cutting edges of the two tools 8 are located should ensure that the guide rod 4 contacts the cutting edges of the tools 8 as soon as it leaves the guide rail 3, so that when the guide rod 4 is separated from the bullet, that is, after the acceleration is completed, the workpiece 5 to be processed contacts the tools 8 at the highest speed, and the tools 8 start to cut the workpiece 5 to be processed.

[0041] The cutting mechanism includes a chip flute 6, a tool holder 7, a tool 8, a force sensor 9, a three-way adjustable slide 10, and a slide base 11. The cutting mechanism is symmetrical. Two tools 8 of identical specifications are connected via two tool holders 7 and two force sensors 9, respectively. The force sensors 9 can measure frequencies up to 1MHz. The force sensors 9 are connected to the surface of the three-way adjustable slide 10 via screws. The three-way adjustable slide 10 can drive the tool 8 and force sensor 9 in three directions. The three-way adjustable slide 10 is connected to the slide base 11 via screws. The chip flute 6 is mounted on the side of the slide base 11, and the tool 8 is located in the chip flute 6.

[0042] The recycling box 12 is arranged behind the cutting mechanism and filled with a large amount of EVA sponge as a cushioning material to protect the processed workpiece. A high-speed camera and a thermal imager are arranged above the tool 8 using a bracket to facilitate observation of the cutting process, collection of cutting speed and cutting heat.

[0043] Application examples:

[0044] The tool 8 used in this embodiment is model N331.1A-08 45 08M-KM3330, with a rake angle of 0°, an inclination angle of 0°, and a lead angle of 90°, enabling right-angle cutting of the workpiece 5. The workpiece 5 measures 40 mm × 20 mm × 3 mm. The depth of cut is 0.1 mm. The guide rod is 105 mm long and made of 7075 aluminum alloy.

[0045] The specific steps of a high-speed cutting experimental method based on secondary impact technology and high precision are as follows:

[0046] Step 1: Fix the workpiece 5 to be processed to the guide rod 4, place the guide rod 4 in the mounting groove 31 of the guide rail 3, fix the tool 8 on the tool clamp 7, fix the tool clamp 7 on the force sensor 9, install the force sensor 9 on the table top of the three-way adjustable slide 10, fix the three-way adjustable slide 10 on the slide base 11, and install the chip collection groove 6 on the side of the slide base 11.

[0047] Step 2: Fix the high-speed camera and thermal imager in a vertical direction through a tripod, adjust the focal length, swing position and system parameters of the lens so that the image size that can be captured completely covers the cutting part of the tool 8 to be observed.

[0048] Step 3, perform tool setting operation. Turn the X-direction handle of the three-way adjustable slide 10 to bring the tool 8 close to the workpiece 5 to be processed, until the distance between the tool 8 and the workpiece 5 to be processed is less than 20 mm, so as to compare whether the width of the workpiece is all within the cutting edge and ensure that the workpiece can be completely cut. Turn the Z-direction handle of the three-way adjustable slide 10 close to the workpiece 5 to be processed, and adjust the vertical direction so that the thickness of the workpiece 5 to be processed completely corresponds to the range of the length of the cutting edge of the tool 8. At the same time, turn the Y-direction and X-direction handles of the three-way adjustable slide 10 to make the outer side of the cutting edge of the tool 8 contact the surface to be processed of the workpiece 5 to be processed, that is, the tool setting is completed, turn the X-direction handle of the three-way adjustable slide 10 to retract the tool to the set position. Since the adjustable slide 10 has self-locking function, the tool can remain in the X-direction position unchanged during the experiment.

[0049] Step 4, adjust the cutting depth, turn the Y-direction handle of the three-way adjustable slide 10 to move the three-way adjustable slide 10 in the Y direction toward the workpiece 5. Since the scale of the three-way adjustable slide 10 is 0.02mm / grid, turning the handle 5 grids adjusts the cutting depth to 0.1mm.

[0050] Since the two three-way adjustable slides 10 have the same structure and are symmetrically arranged, the same operations of step 3 and step 4 are performed on the two three-way adjustable slides.

[0051] Step 5: Place the bullet at the entrance of the launch tube 1, adjust the air pressure of the air box, open the air valve switch and trigger the force sensor 9, high-speed camera and thermal imager at the same time. The bullet accelerates along the launch tube 1 and moves to the exit of the launch tube 1. The bullet acts on the guide rod 4, and the speed of the bullet is converted into the speed of the guide rod 4. The guide rod 4 accelerates and flies out along the guide rail 3 with the workpiece 5 to be processed, contacts the tool 8 on the right to complete the cutting, and then enters the recovery box 12.

[0052] Step 6: Obtain chips and processed workpieces, obtain cutting force data through force sensors, observe the cutting process through high-speed cameras and obtain cutting speed data during the cutting process, and obtain cutting temperature data through thermal imagers for high-speed cutting mechanism research.

[0053] The above content is only for explaining the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A high-speed orthogonal cutting experimental device based on secondary impact technology, characterized in that: It includes a power system, a launching mechanism, a cutting mechanism and a high-speed camera; the launching mechanism and the cutting mechanism are coaxially arranged; The power system includes an air box and a bullet, and the bullet is used to provide power to the guide rod (4); The launching mechanism comprises a launching tube (1), a base (2) and a guide rail (3) which are fixedly connected in sequence; a mounting groove is provided on the guide rail (3), the mounting groove being a square groove, a guide rod (4) being installed in the mounting groove, the guide rod (4) being installed at the exit position of the launching tube (1), the total length of the guide rod being 105 mm, the mass of the guide rod being the same as the mass of the bullet, the acceleration time being changed by changing the length of the guide rod extending relative to the guide rail, the guide rod being made of 7075 aluminum alloy, and the end being wedge-shaped, the guide rod (4) being used to fix the workpiece (5) to be processed; The cutting mechanism comprises two symmetrically arranged cutting parts, the cutting parts comprising a tool clamp (7), a tool (8), a force sensor (9) and a slide, the slide having a self-locking function and being adjustable in three directions; the tool (8) is mounted on the tool clamp (7), the tool clamp (7) and the force sensor (9), and the force sensor (9) is mounted on the slide; The high-speed camera is used to collect images of the entire cutting process.

2. The high-speed orthogonal cutting experimental device based on secondary impact technology according to claim 1 is characterized in that: The installation groove is a square groove.

3. The high-speed orthogonal cutting experimental device based on secondary impact technology according to claim 1 is characterized in that: The weight of the guide rod (4) is equal to the weight of the bullet.

4. The high-speed orthogonal cutting experimental device based on secondary impact technology according to claim 1 is characterized in that: A chip collecting groove (6) is provided on the side of the cutting mechanism.

5. The high-speed orthogonal cutting experimental device based on secondary impact technology according to claim 1 is characterized in that: A recovery box (12) is provided outside the cutting mechanism, and the recovery box (12) is filled with buffer material.

6. The high-speed orthogonal cutting experimental device based on secondary impact technology according to claim 1 is characterized in that: The frequency of the force sensor (9) is greater than 1 MHz.

7. The high-speed orthogonal cutting experimental device based on secondary impact technology according to claim 1 is characterized in that: The device also includes a thermal imager, which is used to collect cutting thermal images.

8. A high-speed orthogonal cutting experimental method based on secondary impact technology, based on the experimental device according to claim 1, characterized in that: The following steps are involved: Step 1: Fixedly connect the workpiece to be processed (5) and the guide rod (4); Step 2: Adjust the X-direction position of the slide so that the tool (8) is close to the workpiece (5) to be processed, and adjust the Z-direction position of the slide so that the thickness of the workpiece (5) to be processed completely corresponds to the range of the length of the cutting edge of the tool (8); at the same time, adjust the Y-direction and X-direction positions of the slide so that the outer side of the cutting edge of the tool (8) contacts the surface to be processed of the workpiece (5) to complete the tool setting; by adjusting the X-direction position of the slide, the tool is retreated to the set position; Step 3, moving the slide in the Y direction toward the workpiece (5) until the cutting depth is equal to the set value; Step 4: Place the bullet at the entrance of the launch tube (1), adjust the air pressure of the air box, open the air valve switch and trigger the force sensor (9) and the high-speed camera at the same time. The bullet accelerates along the launch tube (1) and acts on the guide rod (4) when it moves to the exit of the launch tube (1). The guide rod (4) flies out along the guide rail (3) with the workpiece (5) to be processed and contacts the tool (8) on the right to complete the cutting. Step 5: Obtain chips and processed workpieces, obtain cutting force data through a force sensor, observe the cutting process through a high-speed camera and obtain cutting speed data of the cutting process.

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