Plate type nuclear fuel element assembling tool

Abstract

The utility model belongs to the technical field of nuclear fuel element manufacturing, and particularly relates to a plate type nuclear fuel element assembling tool. The vacuum suction cup is installed on the tool base body, and an X-direction positioning boss and a Z-direction positioning boss are designed on the upper surface of the vacuum suction cup. The tool base body is designed to have an included angle of 89 degrees and 40 minutes. And the vacuum chuck adopts five vacuum chambers. And the five vacuum chambers are respectively provided with five vacuum valves. The vacuum chuck is provided with a pressure gauge. The tool base body is fixed through a T-shaped groove of a machine tool workbench. The tool base body is integrally formed by HT250 cast iron. The vacuum chuck is composed of a chuck body, a surface sealing gasket and an air path. The vacuum chucks fix the side plates. According to the assembling tool, the side plates can be machined firstly and then rolled and assembled after being machined to the finished product size, the appearance size and the form and location tolerance after assembling can meet the technical requirements, the key technical difficulty of rolling and assembling of the novel plate type fuel assembly is solved, and development of the novel fuel assembly is smoothly carried out.

Description

Technical Field

[0001] This utility model belongs to the field of nuclear fuel element manufacturing technology, specifically relating to a plate-type nuclear fuel element assembly tooling. Background Technology

[0002] A current type of plate-type nuclear fuel element primarily uses 6061Al fuel plates. The fuel plates are rolled and formed using a fixed assembly fixture. Grooves are machined into the side plates, which are parallel in structure. Fuel plates of equal width are inserted into the grooves. The fixed assembly fixture fixes the side plates to the machined grooves and fuel plate insertion grooves. After inserting the fuel plates, they are rolled and assembled. The fixture ensures the dimensional stability between the side plates, the bonding force between the fuel plates, and the water gap between the fuel plates. Previous technology allowed machining allowances in the side plates for roll assembly before shaping. This new plate-type fuel assembly technology requires that the side plates be machined to the finished dimensions before roll assembly, necessitating precise positioning of the side plates to ensure that the assembled dimensions and geometric tolerances meet technical requirements. Utility Model Content

[0003] The purpose of this utility model is to provide a tooling for assembling plate-type nuclear fuel elements. It solves the problem of first processing the side plates and then relying on the tooling to achieve the dimensional and positional tolerances of the plate-type fuel assembly. The tooling is a fixed assembly tooling. The side plates are fixed on the tooling for processing grooves and fuel plate insertion grooves. After the fuel plates are inserted, they are rolled and assembled. The tooling ensures the dimensional and positional tolerances between the side plates of the element, the bonding force between the fuel plates and the side plates, and the water gap between the fuel plates.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] A plate-shaped nuclear fuel element assembly fixture, wherein a vacuum chuck is mounted on the fixture base, and the upper surface of the vacuum chuck is designed with an X-axis positioning boss and a Z-axis positioning boss.

[0006] The tooling base is designed with an included angle of 89°40′.

[0007] The vacuum suction cup uses 5 vacuum chambers.

[0008] Each of the five vacuum chambers is equipped with a vacuum valve.

[0009] The vacuum suction cup is equipped with a pressure gauge.

[0010] The T-slot of the machine tool worktable fixes the tooling base.

[0011] The tooling base is made of HT250 cast iron in one piece.

[0012] A vacuum suction cup consists of a suction cup, a surface sealing gasket, and an air passage.

[0013] Vacuum suction cups are used to fix the side plates.

[0014] The side plate is made of 6061 aluminum and has a multi-layered groove structure inside, with the fuel plate inserted into the groove.

[0015] The beneficial effects achieved by this utility model are as follows:

[0016] The fixture features side plate positioning in the X and Z directions to ensure installation accuracy. It allows for direct roll forming assembly without disassembly after slotting on the fixture, or removal from the fixture after milling the side plates for inspection. Once inspected and approved, the plates are reinstalled for roll forming, ensuring consistent installation accuracy and eliminating misalignment. After installation, the fixture guarantees the component's width dimension, with an overall component size of (76.2±0.1) mm. The modular design of the fixture reduces manufacturing difficulty and cost, and also simplifies angle correction machining during subsequent debugging.

[0017] The assembly fixture designed in this invention enables the side plates to be pre-processed to their finished dimensions before roll forming and assembly, ensuring that the final dimensions and geometric tolerances meet technical requirements. This solves the key technical challenges of roll forming and assembling novel plate-type fuel assemblies, facilitating the smooth development of these assemblies. Attached Figure Description

[0018] Figure 1 Schematic diagram of side panel structure;

[0019] Figure 2 Assembly tooling diagram;

[0020] Figure 3 Schematic diagram of vacuum suction cup structure;

[0021] 1. Machine tool worktable; 2. Tooling base; 3. Vacuum chuck; 4. Side plate; 5. Vacuum valve; 6. Vacuum chamber; 7. X-axis positioning boss; 8. Z-axis positioning boss. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0023] This fixture is used for the roll-forming assembly of plate-type nuclear fuel elements. The fixture's main structure consists of a fixture base and a vacuum chuck, a modular design that reduces manufacturing difficulty and cost. The vacuum chuck is mounted on the fixture base and can be disassembled for angle correction. It can also be machined, reducing machining difficulty compared to machining the fixture base. Because the fixture's angle increases due to stress during roll-forming assembly, the fixture base is designed with an 89°40′ included angle (adjusted according to experimental requirements) to ensure it reaches 90° after being subjected to stress during roll-forming assembly. Since the side plates are machined to finished dimensions and lack a fixed clamping position during roll-forming assembly, a vacuum chuck structure is used for fixation. The vacuum chuck employs five vacuum chambers, each controlled by a valve, and a pressure gauge monitors the vacuum pressure. A leak in one area will not affect the overall adsorption effect, preventing reduced adsorption force, side plate movement, or detachment, thus reducing safety risks during assembly. The upper surface of the vacuum suction cup is designed with X-axis positioning bosses and Z-axis positioning bosses to ensure the installation position accuracy of the side plate.

[0024] A plate-type nuclear fuel element assembly fixture mainly consists of two parts: a fixture base 2 and a vacuum suction cup 3. This modular structure reduces manufacturing difficulty and cost. The vacuum suction cup 3 is mounted on the fixture base 2 and can be disassembled when angle correction is needed. The vacuum suction cup 3 can also be machined, reducing machining difficulty compared to machining the fixture base 2. Since the fixture angle increases due to stress during the rolling assembly process, the fixture base 2 is designed with an 89°40′ included angle (adjusted according to experimental requirements) to ensure it equals 90° after being subjected to stress during rolling assembly. Because the side plates 4 are machined to finished dimensions, there is no fixed clamping position during rolling assembly. The vacuum suction cup 3 is used for fixation. The vacuum suction cup uses five vacuum chambers 6, each controlled by five vacuum valves 5, and pressure gauges are installed to monitor the vacuum pressure. A leak in one area will not affect the overall adsorption effect, preventing reduced adsorption force or the movement or detachment of the side plates 4, thus reducing safety risks during assembly. The upper surface of the vacuum suction cup 3 is designed with an X-axis positioning boss 7 and a Z-axis positioning boss 8 to ensure the installation position accuracy of the side plate 4.

[0025] The assembly fixture includes a machine tool worktable 1, fixture base 2, vacuum chuck 3, side plate 4, vacuum valve 5, vacuum chamber 6, X-axis positioning boss 7, and Z-axis positioning boss 8.

[0026] Machine tool worktable 1: It is the structure of the machine tool itself and plays a supporting and connecting role. The tooling base 2 is fixed by the T-slot of the machine tool worktable 1 and connected to the machine tool worktable 1 by M16 high-strength bolts.

[0027] Tooling base 2: Made of HT250 cast iron or other tooling materials in one piece to ensure the rigidity and accuracy of tooling base 2. Since the tooling angle will increase due to stress during the rolling assembly process, tooling base 2 is designed with an 89°40′ included angle (the angle will be corrected according to the test requirements) to ensure that it is equal to 90° after being subjected to stress during the rolling assembly process.

[0028] Vacuum suction cup 3: Vacuum suction cup 3 is a mechanical tool that uses the principle of negative pressure to generate suction. It mainly consists of a suction cup (flatness ≤ 0.02mm), a surface sealing gasket, and an air passage. Since there is no clamping allowance on the side of the side plate 4, the suction cup is used to fix the side plate 4 to prevent it from falling off or moving during grooving and rolling assembly.

[0029] Side plate 4: One of the structural components of the fuel assembly, serving as the mounting carrier for the test material plate. It is made of 6061 aluminum and has a multi-layered groove structure machined inside. The fuel plate is inserted into the groove and rolled and pressed using a special rolling assembly tool to fix the fuel plate and ensure a certain bonding force and water gap size accuracy.

[0030] Vacuum valve 5: Installed on vacuum suction cup 3, with the other end connected to the vacuum pump system via a vacuum pipeline, enabling individual control of each vacuum chamber. If a single vacuum chamber experiences depressurization, it can be shut off individually.

[0031] Vacuum Chamber 6: The vacuum suction cup 3 is designed with a structure of 5 vacuum chambers 6, which are individually controlled by vacuum valves 5. This ensures that even if one or more vacuum chambers leak, there is still enough vacuum to position the workpiece in accordance with the requirements of high-strength wear-resistant materials and precise dimensions. This ensures a high degree of consistency in positioning accuracy and improves product quality and production efficiency.

[0032] X-direction positioning boss 7: When the side plate 4 is installed, it plays a role in X-direction positioning, ensuring the consistency and accuracy of repeated installation of the side plate.

[0033] Z-direction positioning boss 8: When the side plate 4 is installed, it plays a Z-direction positioning role to ensure the consistency and accuracy of repeated installation of the side plate.

[0034] Assembly tooling work implementation process:

[0035] Step 1: Assemble the fixture for use on the vertical machining center. First, place the fixture on the machine tool worktable 1. Use a dial indicator to align the fixture in the X and Y directions (according to the coordinate system of the machining center) and ensure that the alignment is within 0.02mm. Then, use high-strength bolts to fix the fixture base 2 to the machine tool worktable.

[0036] Step 2: Connect the vacuum line to the vacuum valve 5 of the tooling. Test and confirm the vacuum effect. When the air path on the base of the vacuum suction cup 3 is connected to the vacuum pump, air will flow into the air path from the suction hole at the bottom of the suction cup. Through the coordinated control of components such as the air line, solenoid valve, and cylinder, the suction and release process is completed. After air is sucked in, the air path will close, forming a vacuum state, thereby creating suction between the vacuum suction cup 3 and the side plate 4. When it is necessary to release the side plate 4, compressed air in the air path can be sent into the base of the vacuum suction cup 3 through the cylinder, using compressed air to break the suction force between the vacuum suction cup 3 and the side plate 4, completing the release action.

[0037] Step 3: Fixing side plate 4. Align one end of side plate 4 with the X-direction positioning boss 7, close to the suction cup clamping surface, and press the lower edge of the side plate against the Z-direction positioning boss 8 to achieve equal height for both side plates. Start the machine tool program. After receiving the signal from the machine tool, the vacuum pump starts to perform suction on the vacuum suction cup 3. Once the vacuum pressure reaches the preset value, the fixing of side plate 4 is completed.

[0038] Step 4: Machining of process slots and insert plate slots. Start the machining program to mill the process slots and insert plate slots. After the vacuum chuck 3 is depressurized, remove the side plate 4 for dimensional inspection.

[0039] Step 5: Fixing the component side plate. Re-clamp the qualified side plate according to step 3.

[0040] Step 6: Assemble the fuel plates. Insert the first fuel plate into the X-axis positioning boss 7 end, start the program to roll both sides of the fuel plate, and then insert the next fuel plate in sequence, assembling according to the above operation.

[0041] Step 7: Fuel element removal. After depressurizing the vacuum suction cup 3, remove the fixing bolts near the outer side of the tooling base 2, move the tooling on one side of the tooling base 2 outward to increase the distance between the toolings, and take out the fuel element for dimensional inspection.

Claims

1. A plate-type nuclear fuel element assembly tooling, characterized by: The vacuum chuck is installed on the tool base body, and the upper surface of the vacuum chuck is designed with X-direction positioning boss and Z-direction positioning boss; the vacuum chuck adopts five vacuum chambers, and the five vacuum chambers are respectively provided with five vacuum valves; the vacuum chuck is fixed with side plate, the material of the side plate is 6061 aluminum, and the inside is processed with multi-layer groove structure, and the fuel plate is inserted into the groove.

2. The panel-type nuclear fuel element assembly tooling of claim 1, wherein: The tool base body is designed as 89°40' angle.

3. The plate-type nuclear fuel element assembly tooling of claim 1, wherein: The vacuum chuck is installed with pressure gauge.

4. The panel-type nuclear fuel element assembly tooling of claim 1, wherein: The T-shaped groove of the machine tool workbench is used to fix the tool base body.

5. The panel-type nuclear fuel element assembly tooling of claim 1, wherein: The tool base body is integrally formed by using HT250 cast iron.

6. The panel-type nuclear fuel element assembly tooling of claim 1, wherein: The vacuum chuck is composed of chuck, surface sealing gasket and air path.

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