Processing method and processing tool for cathode parts of medical x-ray tubes

Abstract

The application discloses a processing method and processing tool for a cathode part of a medical X-ray tube, and the processing method comprises the following steps: S1, raw material processing, selecting a cylindrical bar as a raw material and cutting a required thickness as a part blank, and then performing heat treatment on the part blank; S2, rough processing, placing the part blank on a surface grinder to perform rough grinding, so that the thickness and flatness of the part blank meet processing requirements, and a process step is reserved outside the part blank during rough grinding; S3, turning processing, clamping the part blank on a four-axis machining center to perform processing treatment on a reference surface, a hole and a slot; and S4, finishing processing, fixing the part blank on a numerical control lathe, turning the process step, and then performing fine grinding, so that a finished part is obtained; the processing method is reasonable in design, effectively improves the processing precision and processing efficiency of the cathode part of the X-ray tube, and is suitable for popularization and use.

Description

Technical Field

[0001] This invention relates to the field of medical device processing technology, specifically to a processing method and tooling for cathode parts used in medical X-ray tubes. Background Technology

[0002] An X-ray tube is a vacuum diode operating at high voltage, a vacuum electronic device that generates X-rays by bombarding a metal target with high-speed electrons. It contains two electrodes: a filament that emits electrons, serving as the cathode, and a target that receives the electron bombardment, serving as the anode. Both electrodes are sealed within a high-vacuum glass or ceramic housing. The power supply of an X-ray tube includes at least a low-voltage power supply to heat the filament and a high-voltage generator to apply high voltage to the electrodes. When a sufficient current is passed through the tungsten filament to generate an electron cloud, and a sufficient voltage (in the kilovolt range) is applied between the anode and cathode, the electron cloud is drawn towards the anode. At this point, the electrons, in a high-energy, high-speed state, bombard the tungsten target. Upon reaching the target surface, the high-speed electrons are suddenly stopped, and a small portion of their kinetic energy is converted into radiant energy, emitted as X-rays. This type of radiation is called bremsstrahlung. Changing the filament current alters the filament temperature and electron emission, thus changing the tube current and X-ray intensity. Changing the excitation potential of the X-ray tube or using different target materials can alter the energy of the incident X-rays or their intensity at different energies. Due to bombardment by high-energy electrons, X-ray tubes operate at very high temperatures, requiring forced cooling of the anode target. Although X-ray tubes have very low energy efficiency in generating X-rays, they remain the most practical X-ray generating devices and are widely used in X-ray instruments. Currently, medical applications mainly categorize them into diagnostic X-ray tubes and therapeutic X-ray tubes.

[0003] However, when machining the cathode support of an X-ray tube, the small gap between the tooling and the product makes it difficult to clamp the product and easily scratches the outer circle when removing the product; the clamping tooling and the product reference surface cannot be completely fitted, which affects the machining accuracy of the product. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method and tooling for processing cathode components for medical X-ray tubes.

[0005] The technical solution of this invention is: a method for processing cathode parts for medical X-ray tubes, comprising the following steps:

[0006] S1, Raw material processing;

[0007] Select a cylindrical bar with a diameter 8-12 mm larger than the target diameter of the part as the raw material, and cut the raw material with a thickness 3-6 mm larger than the target thickness of the part to obtain the part blank; then heat the part blank to 750-830℃ and hold it for 3-5 hours, and finally cool it to room temperature with the furnace, and remove the oxide scale on the surface of the part blank.

[0008] S2, rough machining;

[0009] The part blank processed in step S1 is placed on a surface grinder for rough grinding to make the thickness and flatness of the part blank meet the processing requirements. During the rough grinding process, the single-sided machining allowance of the part blank is controlled to be 0.2-0.4mm. A process step with a height of 1-2mm and a width of 2-4mm is reserved at the bottom of the outer side of the part blank.

[0010] S3, Turning;

[0011] The workpiece blank processed in step S2 is clamped on a four-axis machining center for machining of the reference surface, holes and slots. During the process, the feed rate of the cutting tool is controlled to be 0.1 to 0.2 mm / r and the cutting speed is 40 to 55 m / min.

[0012] S4, finishing;

[0013] The part blank processed in step S3 is fixed on a CNC lathe, and the process step reserved at the bottom of the outer side of the part blank in step S2 is machined. Then, it is finely ground to make the surface finish, thickness and roughness of the part blank meet the requirements of use, and the finished part can be obtained.

[0014] Furthermore, in step S3, during the machining of the workpiece blank's reference surface, holes, and slots, a machining allowance of 0.2–0.4 mm is first reserved. Then, the workpiece blank is heated to 800–900°C and held for 20–55 minutes. Next, the workpiece blank is oil-cooled to 200–350°C and held for 1–3 hours. Finally, the workpiece blank is air-cooled to room temperature. Finally, the workpiece blank undergoes secondary turning machining.

[0015] Note: The machining of the part blank's reference surface, holes, and slots is completed in two stages, which avoids part deformation and dimensional accuracy problems caused by heat treatment of the part blank and improves the part's machining efficiency.

[0016] Furthermore, in step S1, after the part blank is cut, the part blank is placed in a leveling machine to level it, so that the warpage of the part blank is less than 0.3mm.

[0017] Explanation: By leveling the part blank, the amount of turning material during the turning process is reduced, the loss of raw materials is reduced, and the processing cost of the finished part is also reduced.

[0018] Furthermore, before step S2, the workpiece blank is rough-turned. First, the upper end face of the workpiece blank is rough-turned, and then the lower bottom face of the workpiece blank is rough-turned. During the rough-turning process, the feed rate of the cutting tool is controlled to be 0.2-0.3 mm / r, the depth of cut is 0.3-0.5 mm, and the cutting speed is 30-45 m / min; the single-sided machining allowance of the workpiece blank is controlled to be 0.4-0.6 mm.

[0019] Note: By rough turning the two end faces of the part blank, the problem of deformation during the turning process affecting the flatness of the part blank can be overcome.

[0020] Furthermore, in step S4, the part blank is finely ground using a rotary polishing method, with the working pressure of the abrasive flow controlled at 0.3–0.7 MPa, the flow rate range at 5–10 L / S, and the cycle interval at 50–120 min; the rotation speed of the part blank is controlled at 65–851 r / min.

[0021] Note: Using rotary polishing to fine grind the part blank can improve the fine grinding efficiency of the part blank, make the surface finish of the part blank more uniform, and also reduce the generation of fine grinding dead corners.

[0022] Furthermore, the abrasive is one of SiC, SiO2, and ZrO2, and the particle size of the abrasive is 0.1–0.3 mm;

[0023] Furthermore, after step S4 is completed, the finished parts are subjected to flaw detection, cleaning, and surface oiling for protection.

[0024] The present invention also provides a machining fixture for cathode parts for X-ray tubes, applicable to the above-mentioned machining method for cathode parts for medical X-ray tubes, including a tooling chuck, a clamping assembly disposed on the tooling chuck, and a clamping assembly disposed on the tooling chuck and connected to the clamping assembly; a connecting post is provided at one end of the tooling chuck, and a stepped hole is provided through the tooling chuck; several arc-shaped grooves are provided at equal intervals on the tooling chuck and located outside the stepped hole.

[0025] The clamping assembly includes a drive disk that is rotatably engaged inside the tooling chuck and located outside the stepped hole, clamping blocks that are slidably engaged inside each arc-shaped groove, and a positioning component located at the other end of the tooling chuck and connected to the drive disk; a push groove is provided through the drive disk at a position corresponding to the arc-shaped groove, and a connecting rod that penetrates the tooling chuck is provided on the side of the drive disk near the positioning component; a screw that penetrates the arc-shaped groove and push groove at the corresponding position is rotatably engaged on the bottom surface of each clamping block; the positioning component includes a positioning frame provided on the side wall of the tooling chuck and an operating pull rod that is slidably engaged on the positioning frame and movably inserted into the connecting rod; a return spring that abuts against the inner wall of the connecting rod is sleeved on the operating pull rod, and a toothed bar that can engage with the positioning frame is provided at the connection between the operating pull rod and the positioning frame;

[0026] The clamping assembly includes a gear ring that is rotatably engaged with the upper and lower bottom surfaces of the tooling chuck and located inside each arc-shaped slide groove; a clamping gear that is threaded to each screw and slidably engaged with the arc-shaped slide groove at the corresponding position; and an adjusting gear that is rotatably engaged with the upper and lower bottom surfaces of the tooling chuck and meshes with the gear ring; each clamping gear can mesh with the gear ring; and the adjusting gear is provided with an internal hexagonal adjusting hole.

[0027] Furthermore, the connecting rod is provided with a guide rod that slides and engages with the positioning frame;

[0028] Note: By setting guide rods, the stability of the connecting rod when it moves on the positioning frame is improved, thereby improving the clamping effect of the clamping assembly on the workpiece blank.

[0029] The method of using the tooling of the present invention is as follows:

[0030] Place the workpiece blank inside the stepped hole of the tooling chuck. Pull the operating lever outward and move it to rotate the drive disc. At this time, each screw slides synchronously under the action of the push groove and the arc-shaped slide groove, and moves the clamping block closer to the process step of the workpiece blank. Release the operating lever, and the operating lever will return to its original position under the action of the return spring, and be locked by the gear bar and the positioning frame. After the screw moves, the clamping gears connected to the screws mesh with the gear ring. Turn the adjusting gear with the adjusting gear wrench, and the adjusting gear will drive the gear ring to rotate, so that each clamping gear rotates synchronously. Under the action of the rotation of the clamping gear, the screw pulls the corresponding clamping block downward, pressing and fixing the process step of the workpiece blank. Finally, the tooling chuck is clamped to the four-axis machining center through the connecting column.

[0031] Compared with the prior art, the beneficial effects of the present invention are reflected in the following aspects:

[0032] First, the processing method of the present invention is reasonably designed. By heat treatment and rough grinding of the part blank, the structural strength and internal uniformity of the finished part are effectively improved. The part blank after rough grinding requires less processing and shortens the processing cycle of the subsequent finished part.

[0033] Secondly, once the part blank of the present invention is clamped, the processing process from part blank to finished part can be completed, which solves the problem of surface scratches on part blank caused by multiple clamping, and effectively improves the processing quality and processing efficiency of cathode parts for X-ray tubes.

[0034] Third, when the processing fixture of the present invention is used, the rotation of the drive disc drives each clamping block to move horizontally, and the rotation of the clamping gear drives each clamping block to move up and down, thereby making the clamping of the workpiece blank more efficient; at the same time, since each clamping block moves synchronously, the clamping force of each clamping block on the workpiece blank is consistent, thereby improving the clamping stability and reliability of the workpiece blank. Attached Figure Description

[0035] Figure 1 This is a longitudinal sectional view of the tooling of the present invention;

[0036] Figure 2 This is a top view of the tooling of the present invention;

[0037] Figure 3 This is a schematic diagram showing the connection between the drive disk and the working chuck of the present invention;

[0038] Figure 4 This is a schematic diagram showing the connection between the positioning component and the drive disk of the present invention;

[0039] Figure 5 This is a schematic diagram showing the connection between the clamping assembly and the tooling chuck of the present invention;

[0040] Figure 6 This is a schematic diagram of the structure of the finished part in Embodiment 1 of the present invention;

[0041] Among them, 1-tooling chuck, 10-connecting column, 11-step hole, 12-arc slide groove, 2-clamping assembly, 20-drive disk, 200-push groove, 201-connecting rod, 2010-guide rod, 21-clamping block, 210-screw, 22-positioning component, 220-positioning frame, 221-operating pull rod, 222-reset spring, 223-tooth bar, 3-pressing assembly, 30-tooth ring, 31-pressing gear, 32-adjusting gear. Detailed Implementation

[0042] Example 1

[0043] A method for manufacturing cathode components for medical X-ray tubes includes the following steps:

[0044] S1, Raw material processing;

[0045] Select a cylindrical bar with a diameter 12mm larger than the target diameter of the part as the raw material, and cut the raw material with a thickness 6mm larger than the target thickness of the part to obtain the part blank; then heat the part blank to 750℃ and hold it for 5 hours, and finally cool it to 25℃ with the furnace, and remove the oxide scale on the surface of the part blank.

[0046] S2, rough machining;

[0047] The part blank processed in step S1 is placed on a surface grinder for rough grinding to make the thickness and flatness of the part blank meet the processing requirements. During the rough grinding process, the single-sided machining allowance of the part blank is controlled to be 0.4mm; and a process step with a height of 2mm and a width of 4mm is reserved at the bottom of the outer side of the part blank.

[0048] S3, Turning;

[0049] The workpiece blank processed in step S2 is clamped on a four-axis machining center for machining of the reference surface, holes and slots. During the process, the feed rate of the cutting tool is controlled at 0.2 mm / r and the cutting speed is 55 m / min.

[0050] S4, finishing;

[0051] The part blank processed in step S3 is fixed on a CNC lathe, and the process step reserved at the bottom of the outer side of the part blank in step S2 is machined. Then, it is finely ground to make the surface finish, thickness and roughness of the part blank meet the requirements of use, and the finished part can be obtained.

[0052] Example 2

[0053] A method for manufacturing cathode components for medical X-ray tubes includes the following steps:

[0054] S1, Raw material processing;

[0055] Select a cylindrical bar with a diameter 10 mm larger than the target diameter of the part as the raw material, and cut the raw material with a thickness 5 mm larger than the target thickness of the part to obtain the part blank; then heat the part blank to 810℃ and hold it for 4 minutes, and finally cool it to 27℃ with the furnace and remove the oxide scale on the surface of the part blank.

[0056] S2, rough machining;

[0057] The part blank processed in step S1 is placed on a surface grinder for rough grinding to make the thickness and flatness of the part blank meet the processing requirements. During the rough grinding process, the single-sided machining allowance of the part blank is controlled to be 0.3mm. A process step with a height of 1mm and a width of 3mm is reserved at the bottom of the outer side of the part blank.

[0058] S3, Turning;

[0059] The workpiece blank processed in step S2 is clamped on a four-axis machining center for machining of the reference surface, holes, and slots. During the processing, the feed rate of the cutting tool is controlled at 0.2 mm / r, and the cutting speed is 50 m / min. In the machining process of the reference surface, holes, and slots of the workpiece blank, a machining allowance of 0.2 mm is first reserved. Then, the workpiece blank is heated to 800℃ and held for 20 min. Then, the workpiece blank is oil cooled to 200℃ and held for 1 h. Then, the workpiece blank is air cooled to 27℃. Finally, the workpiece blank is subjected to a second turning process.

[0060] S4, finishing;

[0061] The part blank processed in step S3 is fixed on a CNC lathe, and the process step reserved at the bottom of the outer side of the part blank in step S2 is machined. Then, it is finely ground to make the surface finish, thickness and roughness of the part blank meet the requirements of use, and the finished part can be obtained.

[0062] Example 3

[0063] A method for manufacturing cathode components for medical X-ray tubes includes the following steps:

[0064] S1, Raw material processing;

[0065] Cylindrical bars with a diameter 8mm larger than the target diameter of the part are selected as raw materials, and the thickness of the raw materials is cut to be 3mm larger than the target thickness of the part to obtain the part blank. The part blank is then heated to 830℃ and held for 5 hours, and finally cooled to 26℃ in the furnace, and the oxide scale on the surface of the part blank is removed. The part blank is then placed in a leveling machine to level it so that the warpage of the part blank is 0.2mm. The part blank is then rough-turned. First, the upper end face of the part blank is rough-turned, and then the lower bottom face of the part blank is rough-turned. During the rough-turning process, the feed rate of the cutting tool is controlled to be 0.2mm / r, the depth of cut is 0.3mm, and the cutting speed is 30m / min. The single-sided machining allowance of the part blank is controlled to be 0.4mm.

[0066] S2, rough machining;

[0067] The part blank processed in step S1 is placed on a surface grinder for rough grinding to make the thickness and flatness of the part blank meet the processing requirements. During the rough grinding process, the single-sided machining allowance of the part blank is controlled to be 0.3mm; and a process step with a height of 2mm and a width of 4mm is reserved at the bottom of the outer side of the part blank.

[0068] S3, Turning;

[0069] The workpiece blank processed in step S2 is clamped on a four-axis machining center for machining of the reference surface, holes and slots. During the process, the feed rate of the cutting tool is controlled at 0.2 mm / r and the cutting speed is 55 m / min.

[0070] S4, finishing;

[0071] The part blank processed in step S3 is fixed on a CNC lathe, and the process step reserved at the bottom of the outer side of the part blank in step S2 is machined. Then, it is finely ground to make the surface finish, thickness and roughness of the part blank meet the requirements of use, and the finished part can be obtained.

[0072] Example 4

[0073] A method for manufacturing cathode components for medical X-ray tubes includes the following steps:

[0074] S1, Raw material processing;

[0075] Select a cylindrical bar with a diameter 10 mm larger than the target diameter of the part as the raw material, and cut the raw material with a thickness 5 mm larger than the target thickness of the part to obtain the part blank; then heat the part blank to 810℃ and hold it for 4 minutes, and finally cool it to 27℃ with the furnace and remove the oxide scale on the surface of the part blank.

[0076] S2, rough machining;

[0077] The part blank processed in step S1 is placed on a surface grinder for rough grinding to make the thickness and flatness of the part blank meet the processing requirements. During the rough grinding process, the single-sided machining allowance of the part blank is controlled to be 0.3mm. A process step with a height of 1mm and a width of 3mm is reserved at the bottom of the outer side of the part blank.

[0078] S3, Turning;

[0079] The workpiece blank processed in step S2 is clamped on a four-axis machining center for machining of the reference surface, holes and slots. During the process, the feed rate of the cutting tool is controlled at 0.2 mm / r and the cutting speed is 50 m / min.

[0080] S4, finishing;

[0081] The part blank processed in step S3 is fixed on a CNC lathe, and the process step reserved at the bottom of the part blank in step S2 is machined. The part blank is then finely ground by rotary polishing, with the working pressure of the abrasive flow controlled at 0.3MPa, the flow rate range at 5L / S, and the circulation interval at 50min; the rotation speed of the part blank is controlled at 65r / min; the abrasive is SiC, and the abrasive particle size is 0.1~0.2mm; the surface finish, thickness, and roughness of the part blank meet the requirements for use, and the finished part is obtained. Finally, the finished part is subjected to flaw detection, cleaning, and surface coating with mineral oil for protection.

[0082] Example 5

[0083] A method for manufacturing cathode components for medical X-ray tubes includes the following steps:

[0084] S1, Raw material processing;

[0085] Cylindrical bars with a diameter 8mm larger than the target diameter of the part are selected as raw materials, and the thickness of the raw materials is cut to be 3mm larger than the target thickness of the part to obtain the part blank. The part blank is placed in a leveling machine to level it so that the warpage of the part blank is 0.2mm. Then the part blank is heated to 830℃ and held at that temperature for 5 hours. Finally, it is cooled to 27℃ in the furnace, and the oxide scale on the surface of the part blank is removed. The part blank is rough turned. First, the upper end face of the part blank is rough turned, and then the lower bottom face of the part blank is rough turned. During the rough turning process, the feed rate of the cutting tool is controlled at 0.3mm / r, the depth of cut is 0.5mm, and the cutting speed is 45m / min. The single-sided machining allowance of the part blank is controlled at 0.6mm.

[0086] S2, rough machining;

[0087] The part blank processed in step S1 is placed on a surface grinder for rough grinding to make the thickness and flatness of the part blank meet the processing requirements. During the rough grinding process, the single-sided machining allowance of the part blank is controlled to be 0.3mm; and a process step with a height of 2mm and a width of 4mm is reserved at the bottom of the outer side of the part blank.

[0088] S3, Turning;

[0089] The workpiece blank processed in step S2 is clamped on a four-axis machining center for machining of the reference surface, holes, and slots. During the processing, the feed rate of the cutting tool is controlled at 0.2 mm / r, and the cutting speed is 55 m / min. In the machining process of the reference surface, holes, and slots of the workpiece blank, a machining allowance of 0.4 mm is first reserved. Then, the workpiece blank is heated to 900℃ and held for 55 min. Then, the workpiece blank is oil cooled to 350℃ and held for 3 h. Then, the workpiece blank is air cooled to 25℃. Finally, the workpiece blank is subjected to a second turning process.

[0090] S4, finishing;

[0091] The part blank processed in step S3 is fixed on a CNC lathe, and the process step reserved at the bottom of the part blank in step S2 is machined. The part blank is then finely ground by rotary polishing, with the working pressure of the abrasive flow controlled at 0.7MPa, the flow rate range at 10L / S, and the circulation interval at 120min; the rotation speed of the part blank is controlled at 851r / min; the abrasive is SiO2, and the abrasive particle size is 0.2-0.3mm; the surface finish, thickness, and roughness of the part blank meet the requirements for use, and the finished part is obtained. Finally, the finished part is subjected to flaw detection, cleaning, and surface coating with mineral oil for protection.

[0092] Example 6

[0093] This embodiment describes a machining fixture for cathode components of X-ray tubes, applicable to the machining method of cathode components for medical X-ray tubes in any of Embodiments 1-5, such as... Figure 1 , 2 As shown,

[0094] It includes a tooling chuck 1, a clamping component 2 disposed on the tooling chuck 1, and a clamping component 3 disposed on the tooling chuck 1 and connected to the clamping component 2; a connecting post 10 is provided at one end of the tooling chuck 1, and a stepped hole 11 is provided through the tooling chuck 1; four arc-shaped sliding grooves 12 are provided on the tooling chuck 1 and on the outer side of the stepped hole 11 at equal intervals.

[0095] like Figure 1 , 3 As shown in Figure 4, the clamping assembly 2 includes a drive disk 20 that is rotatably engaged inside the tooling chuck 1 and located outside the stepped hole 11, clamping blocks 21 that are slidably engaged inside each arc-shaped slide groove 12, and a positioning member 22 located at the other end of the tooling chuck 1 and connected to the drive disk 20; a push groove 200 is provided through the drive disk 20 at a position corresponding to the arc-shaped slide groove 12, and a connecting rod 201 that penetrates the tooling chuck 1 is provided on the side of the drive disk 20 near the positioning member 22; and a connecting rod 201 that penetrates the tooling chuck 1 is provided on the lower bottom surface of each clamping block 21 at a corresponding position. The arc-shaped sliding groove 12 and the screw 210 of the pushing groove 200; the positioning component 22 includes a positioning frame 220 set on the side wall of the tooling chuck 1 and an operating pull rod 221 that is slidably engaged with the positioning frame 220 and movably inserted into the connecting rod 201; a return spring 222 that abuts against the inner wall of the connecting rod 201 is sleeved on the operating pull rod 221; a toothed bar 223 that can engage with the positioning frame 220 is provided at the connection between the operating pull rod 221 and the positioning frame 220; a guide rod 2010 that is slidably engaged with the positioning frame 220 is provided on the connecting rod 201;

[0096] like Figure 1 , 4As shown in Figure 5, the clamping assembly 3 includes a gear ring 30 that is rotatably engaged with the lower and upper surfaces of the tooling chuck and located inside each arc-shaped slide groove 12, a clamping gear 31 that is threadedly connected to each screw 210 and slidably engaged with the arc-shaped slide groove 12 at the corresponding position, and an adjusting gear 32 that is rotatably engaged with the lower and upper surfaces of the tooling chuck and meshes with the gear ring 30; each clamping gear 31 can mesh with the gear ring 30; the adjusting gear 32 is provided with an internal hexagonal adjusting hole.

[0097] Test case

[0098] Performance tests were conducted on the finished parts prepared according to Examples 1-5 of the present invention and those prepared using existing technologies. The test results are shown in Table 1.

[0099] Table 1 shows the impact of the methods in each embodiment on the performance of the finished parts.

[0100] Example Flatness / mm Hardness / HV roughness 1 0.6 115 Ra0.3 2 0.4 119 Ra0.3 3 0.3 121 Ra0.2 4 0.2 121 Ra0.2 5 0.2 129 Ra0.2 Comparative Example 0.9 106 Ra0.4

[0101] As can be seen from the data in Table 1, compared with the prior art, the finished parts processed by the present invention have better performance in all aspects. The processing method of the present invention has the advantages of high processing accuracy and stability.

[0102] Compared with Example 1, Example 2 completes the machining of the part blank reference surface, holes and slots in two steps, which effectively solves the problems of part deformation and dimensional accuracy caused by heat treatment of part blank and improves the machining accuracy of part.

[0103] Compared with Example 1, Example 3 reduces the amount of machining during the turning process of the part blank by leveling the part blank, thereby reducing the loss of raw materials and the processing cost of the finished part. By rough turning the two end faces of the part blank, the problem of deformation during the turning process affecting the flatness of the part blank can be overcome.

[0104] Compared with Example 1, Example 4 uses rotary polishing to fine grind the part blank, which can improve the fine grinding efficiency of the part blank, make the surface finish of the part blank more uniform, and also reduce the generation of fine grinding dead corners.

[0105] Compared with Examples 1 to 4, Example 5 shows that by optimizing the process parameters during the processing of finished parts, the performance of the finished parts reaches its optimal state.

Claims

1. A method for processing cathode components for medical X-ray tubes, characterized in that, Includes the following steps: S1, Raw material processing; Select a cylindrical bar with a diameter 8-12 mm larger than the target diameter of the part as the raw material, and cut the raw material with a thickness 3-6 mm larger than the target thickness of the part to obtain a part blank; then heat the part blank to 750-830℃ and keep it at that temperature for 3-5 hours, and finally cool it to room temperature with the furnace, and remove the oxide scale from the surface of the part blank. S2, rough machining; The part blank processed in step S1 is placed on a surface grinder for rough grinding to make the thickness and flatness of the part blank meet the processing requirements. During the rough grinding process, the single-sided machining allowance of the part blank is controlled to be 0.2~0.4mm; and a process step with a height of 1~2mm and a width of 2~4mm is reserved at the bottom of the outer side of the part blank. S3, Turning; The workpiece blank processed in step S2 is clamped on a four-axis machining center for machining of the reference surface, holes and slots. During the process, the feed rate of the cutting tool is controlled to be 0.1~0.2mm / r and the cutting speed is 40~55m / min. S4, finishing; The part blank processed in step S3 is fixed on a CNC lathe, and the process step reserved at the bottom of the outer side of the part blank in step S2 is machined. Then, it is finely ground so that the surface finish, thickness and roughness of the part blank meet the requirements of use, and the finished part can be obtained. A machining fixture for cathode parts of X-ray tubes applicable to the above method is characterized in that it includes a fixture chuck (1), a clamping assembly (2) disposed on the fixture chuck (1), and a clamping assembly (3) disposed on the fixture chuck (1) and connected to the clamping assembly (2); a connecting post (10) is provided at one end of the fixture chuck (1), and a stepped hole (11) is provided through the fixture chuck (1); several arc-shaped grooves (12) are provided on the fixture chuck (1) and at equal intervals on the outside of the stepped hole (11). The clamping assembly (2) includes a drive disk (20) that is rotatably engaged inside the tooling chuck (1) and located outside the stepped hole (11), a clamping block (21) that is slidably engaged inside each of the arc-shaped slides (12), and a positioning member (22) that is located at the other end of the tooling chuck (1) and connected to the drive disk (20); a push groove (200) is provided through the drive disk (20) at a position corresponding to the arc-shaped slide (12), and a connecting rod (201) that penetrates the tooling chuck (1) is provided on the side of the drive disk (20) near the positioning member (22); and an arc-shaped slide that penetrates the corresponding position is rotatably engaged on the bottom surface of each clamping block (21). (12) and the screw (210) of the push groove (200); the positioning component (22) includes a positioning frame (220) provided on the side wall of the tooling chuck (1) and an operating pull rod (221) slidably engaged on the positioning frame (220) and movably inserted into the connecting rod (201); a return spring (222) is sleeved on the operating pull rod (221) and abuts against the inner wall of the connecting rod (201); a toothed bar (223) is provided at the connection between the operating pull rod (221) and the positioning frame (220) and can engage with the positioning frame (220); a guide rod (2010) is provided on the connecting rod (201) and slidably engaged with the positioning frame (220); The clamping assembly (3) includes a gear ring (30) that is rotatably engaged with the upper and lower bottom surfaces of the tooling chuck (1) and located inside each arc-shaped slide groove (12); a clamping gear (31) that is threadedly connected to each screw (210) and slidably engaged with the arc-shaped slide groove (12) at the corresponding position; and an adjusting gear (32) that is rotatably engaged with the upper and lower bottom surfaces of the tooling chuck (1) and meshes with the gear ring (30); each of the clamping gears (31) can mesh with the gear ring (30); and the adjusting gear (32) is provided with an internal hexagonal adjusting hole.

2. The method for processing the cathode part for a medical X-ray tube according to claim 1, characterized in that, In step S3, during the machining of the reference surface, holes and slots of the part blank, firstly, a machining allowance of 0.2~0.4mm is reserved, then the part blank is heated to 800~900℃ and held for 20~55min, then the part blank is oil cooled to 200~350℃ and held for 1~3h, then the part blank is air cooled to room temperature; finally, the part blank is subjected to secondary turning machining.

3. The method for processing the cathode part for a medical X-ray tube according to claim 1, characterized in that, In step S1, after the part blank is cut, the part blank is placed in a leveling machine to level it so that the warpage of the part blank is less than 0.3mm.

4. The method for processing the cathode part for a medical X-ray tube according to claim 1, characterized in that, Before step S2, the part blank is rough turned. First, the upper end face of the part blank is rough turned, and then the lower bottom face of the part blank is rough turned. During the rough turning process, the feed rate of the cutting tool is controlled to be 0.2~0.3mm / r, the depth of cut is 0.3~0.5mm, and the cutting speed is 30~45m / min. The single-sided machining allowance of the part blank is controlled to be 0.4~0.6mm.

5. The method for processing the cathode part for a medical X-ray tube according to claim 1, characterized in that, In step S4, the part blank is finely ground by rotary polishing, and the working pressure of the abrasive flow is controlled to be 0.3~0.7MPa, the flow rate is 5~10L / S, and the cycle interval is 50~120min; the rotation speed of the part blank is controlled to be 65~851r / min.

6. The method for processing the cathode part for a medical X-ray tube according to claim 5, characterized in that, The abrasive is one of SiC, SiO2 and ZrO2, and the particle size of the abrasive is 0.1~0.3mm.

7. The method for processing the cathode part for a medical X-ray tube according to claim 1, characterized in that, After step S4 is completed, the finished parts are subjected to flaw detection, cleaning, and surface oiling for protection.

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