Ejector head device for nuclear fuel rod electron beam welding machine

Abstract

The utility model discloses an ejector head device for a nuclear fuel rod electron beam welding machine, which comprises an outer sleeve arranged on the electron beam welding machine, and relates to the technical field of ejector heads of electron beam welding machines. According to the ejector head device for the nuclear fuel rod electron beam welding machine, the conical blocking groove is formed in the outer sleeve, so that the outer conical ejector head is easily positioned in the outer sleeve, the compression spring and the limiting shaft are arranged between the mounting plate and the sleeve, and the thrust ball bearing is arranged between the outer conical ejector head and the sleeve; when the fuel rod and the outer conical top head need to rotate synchronously, the fuel rod can elastically apply pressure to the pressure spring by taking the sleeve as a medium and the limiting shaft abuts against and limits the sleeve, so that the outer conical top head is easy to break away from the contact of the conical blocking groove, and the outer conical top head and the fuel rod can rotate synchronously through the thrust ball bearing. And the problem of serious friction caused by desynchrony of rotation of the outer conical ejector head and the fuel rod is avoided.

Description

Technical Field

[0001] This utility model relates to the field of electron beam welding machine mandrel technology, specifically a mandrel device for an electron beam welding machine for nuclear fuel rods. Background Technology

[0002] Electron beam welding machines are crucial equipment for welding circumferential welds on fuel rods. They offer high energy output, deep weld penetration, and the ability to perform finishing processes, making them highly favored by nuclear fuel element manufacturers both domestically and internationally. The mandrel is one of the most important tooling components of an electron beam welding machine, directly contacting the fuel rod end plug. During welding, the chuck holds the fuel rod and rotates it. Because there is a certain distance between the chuck and the fuel rod end plug, the mandrel is needed for positioning; otherwise, an excessive distance can create a cantilever beam, causing the fuel rod to swing and making welding impossible. Furthermore, the mandrel must have heat dissipation capabilities. Since the weld is close to the mandrel, and a large amount of heat is generated during welding, if this heat is not dissipated in time, the fuel rod will suffer from poor weld formation or oxidation, affecting its quality.

[0003] In view of this: Announcement No. CN214161734U discloses an electron beam welding machine mandrel for nuclear fuel rods, which can eliminate the poor surface forming or oxidation color of fuel rods caused by the mandrel; and solve the problem of frequent grinding or replacement of the mandrel. The electron beam welding machine mandrel for nuclear fuel rods is a rod-shaped structure. The electron beam welding machine mandrel for nuclear fuel rods has a central through hole. It includes three-layer steps. The tail has threads. The top of the electron beam welding machine mandrel for nuclear fuel rods has a flared opening. The fuel rod and the mandrel mate at the minimum diameter of the small inclined plane. The fuel rod and the mandrel mate with line contact. The beneficial effects of this utility model are: (1) the surface of the fuel rod after welding by the newly designed mandrel is free from poor forming or oxidation color; (2) the service life is increased by 3 times compared with the original mandrel; (3) the yield of the welded fuel rod is improved and the stability is better.

[0004] While the above-mentioned solutions address issues such as poor surface forming or oxidation of fuel rods due to insufficient heat dissipation, shortcomings still exist in practical applications. For instance, the lack of a convenient rotating mechanism makes it difficult for the fuel rods and the mandrel to rotate synchronously, leading to wear on the fuel rod end plugs and ultimately causing rework, scrap, and frequent mandrel replacements, which are time-consuming, labor-intensive, and increase manufacturing costs. To avoid these problems, a mandrel device for an electron beam welding machine for nuclear fuel rods is proposed to address these issues. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides a mandrel device for an electron beam welding machine for nuclear fuel rods, which solves the problem that the lack of a convenient rotating mechanism in the device leads to asynchronous rotation of the fuel rods and the mandrel, which can easily cause wear on the fuel rod end plugs.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a mandrel device for an electron beam welding machine for nuclear fuel rods, comprising an outer sleeve mounted on the electron beam welding machine, an inner mounting plate fixedly connected to the inner sleeve, a sleeve slidably connected to the inner sleeve, a compression spring fixedly connected to the opposite side of the sleeve and the mounting plate, a thrust ball bearing fixedly connected to one end of the sleeve, an outer conical mandrel mounted on one side of the thrust ball bearing, a fuel rod assembled inside the outer conical mandrel, and a conical assembly slot for matching the fuel rod on one side of the outer conical mandrel.

[0007] Preferably, a conical groove is provided on one side of the inner cavity of the outer jacket to match the outer conical top.

[0008] Preferably, a limiting shaft for use with a sleeve is fixedly connected to one side of the mounting plate and inside the compression spring.

[0009] Beneficial effects

[0010] This invention provides a mandrel device for an electron beam welding machine for nuclear fuel rods. Compared with existing technologies, it has the following advantages: By setting a conical groove inside the outer sleeve, the outer conical mandrel is easily positioned inside the outer sleeve. Furthermore, a compression spring and a limiting shaft are set between the mounting plate and the sleeve, and a thrust ball bearing is set between the outer conical mandrel and the sleeve. When synchronous rotation of the fuel rod and the outer conical mandrel is required, the fuel rod can apply elastic pressure to the compression spring through the sleeve, and the limiting shaft can resist and limit the movement of the sleeve. This facilitates the outer conical mandrel's disengagement from the conical groove, thereby enabling synchronous rotation of the outer conical mandrel and the fuel rod via the thrust ball bearing. This avoids the problem of asynchronous rotation between the outer conical mandrel and the fuel rod, which can lead to severe friction. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the external structure of this utility model;

[0012] Figure 2 This is a cross-sectional view of the outer casing structure of this utility model;

[0013] Figure 3 This utility model Figure 2 A magnified view of a section at point A in the middle;

[0014] Figure 4 This is a development diagram of the external conical top and fuel rod structure of this utility model.

[0015] In the diagram: 1. Mounting plate; 2. Compression spring; 3. Outer sleeve; 4. Sleeve; 5. Thrust ball bearing; 6. Outer tapered top; 7. Fuel rod; 8. Tapered groove; 9. Limiting shaft; 10. Tapered assembly slot. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0017] See also Figure 1-4 This utility model provides a technical solution: a top head device for an electron beam welding machine for nuclear fuel rods, including an outer sleeve 3 installed on the electron beam welding machine, an inner mounting plate 1 fixedly connected to the inner side of the outer sleeve 3, a sleeve 4 slidably connected to the inner side of the outer sleeve 3, a compression spring 2 fixedly connected to the opposite side of the sleeve 4 and the mounting plate 1, a thrust ball bearing 5 fixedly connected to one end of the sleeve 4, the thrust ball bearing 5 is designed to withstand thrust loads during high-speed operation, and is composed of a washer-shaped ring with a raceway groove for ball rolling, an outer conical top head 6 is installed on one side of the thrust ball bearing 5, a fuel rod 7 is assembled inside the outer conical top head 6, and a conical assembly slot 10 for use with the fuel rod 7 is opened on one side of the outer conical top head 6;

[0018] Specifically: To facilitate limiting the extension and retraction position of the outer conical top head 6, a limiting shaft 9 for use with the sleeve 4 is fixedly connected to one side of the mounting plate 1 and inside the compression spring 2, and a conical stop groove 8 for use with the outer conical top head 6 is opened on one side of the inner cavity of the outer sleeve 3.

[0019] When in use: fix the outer sleeve 3 in the corresponding position of the electron beam welder, ensure that the end plug of the fuel rod 7 and the outer conical top head 6 are adjusted to the appropriate position, start the electron beam welder and weld normally. The conical assembly slot 10 in the outer conical top head 6 is in close contact with the fuel rod 7, which can dissipate heat through the outer conical top head 6 in time.

[0020] When it is necessary to rotate and adjust the outer conical head 6 and the fuel rod 7, pressing the fuel rod 7 causes the fuel rod 7 to drive the outer conical head 6 to retract into the outer sleeve 3, causing the outer conical head 6 to disengage from the conical stop groove 8. When the outer conical head 6 retracts, it will drive the sleeve 4 to form a blocking and limiting engagement with the limiting shaft 9. Then, the fuel rod 7 is rotated. Because a thrust ball bearing 5 is provided between the outer conical head 6 and the sleeve 4, the outer conical head 6 rotates and adjusts synchronously with the fuel rod 7.

Claims

1. A mandrel assembly for an electron beam welder for nuclear fuel rods, comprising an outer jacket (3) mounted on the electron beam welder, characterized in that: An installation plate (1) is fixedly connected inside the outer sleeve (3). A sleeve (4) is slidably connected inside the outer sleeve (3). A compression spring (2) is fixedly connected to the opposite side of the sleeve (4) and the installation plate (1). A thrust ball bearing (5) is fixedly connected to one end of the sleeve (4). An outer conical head (6) is installed on one side of the thrust ball bearing (5). A fuel rod (7) is assembled inside the outer conical head (6), and a conical assembly slot (10) for matching the fuel rod (7) is opened on one side of the outer conical head (6).

2. The mandrel device for an electron beam welding machine for nuclear fuel rods according to claim 1, characterized in that: The inner cavity of the outer jacket (3) is provided with a conical groove (8) that is used in conjunction with the outer conical top (6).

3. The mandrel device for an electron beam welding machine for nuclear fuel rods according to claim 1, characterized in that: A limiting shaft (9) for use with the sleeve (4) is fixedly connected to one side of the mounting plate (1) and inside the compression spring (2).

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