A cobalt regulating rod assembly unloading torque test fixture

Abstract

The present invention belongs to the technical field of nuclear fuel element assembly process, and specifically relates to a jig for testing the unloading torque of a cobalt regulating rod assembly. The left end of the jig body is a disc structure, with a thread machined in the middle section, and a spring length measurement reference ring is screwed and fixed here with a thread. The right end is a cylindrical rod, and the spring is sleeved on the cylindrical rod. The left end of the threaded rod is fixedly connected to the cylindrical rod of the jig body, and the threaded rod is sequentially loaded with a spring length adjustment nut, a locking nut, and a locking nut compression deformer from left to right. The left end of the inner hole of the locking nut compression deformer is turned into an inner cone, and the right end of the inner hole is threaded and tightened with the threaded rod; the right end of the outer diameter of the locking nut compression deformer is machined into an external hexagonal structure for clamping with a force measuring wrench. The test jig is used to test the unloading torque. After the unloading torque is measured to meet the technical requirements during the test, the formal product is assembled to ensure that the unloading torque of the assembled product meets the design requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear fuel element assembly technology, and in particular relates to a jig for unloading torque testing of a cobalt regulating rod assembly. Background Art

[0002] The production of cobalt regulating rod assemblies is at the forefront of my country's power reactor cobalt production industry chain. No imported technologies are used in the manufacturing process; all are independently developed. The component design specifies an unloading torque of 5N·m-9N·m. This unloading torque is a key technical indicator for ensuring the overall structure and dimensional appearance of the cobalt regulating rod assembly, and is also crucial for ensuring safe operation within the reactor. According to the component design drawings, this technical requirement is achieved through spring force. After assembly, the assembly is broken and unloaded, and the unloading torque is measured. The result is 0, which does not meet this technical requirement. This component is the first of its kind produced in China, and its structure differs significantly from other components. It is a specialized tooling and a nuclear fuel element, and no relevant information has been reported in the relevant field. Summary of the Invention

[0003] The purpose of the present invention is to provide a cobalt regulating rod assembly unloading torque test jig, which is used to conduct an unloading torque test. After the unloading torque is measured to meet the technical requirements during the test, the formal product is assembled to ensure that the unloading torque of the assembled product meets the design requirements.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A jig for testing unloading torque of a cobalt adjusting rod assembly has a disc structure at the left end of the jig main body, a threaded section is machined in the middle section, a spring length measuring reference ring is tightened and fixed here with a thread, the right end is a cylindrical rod, a spring is sleeved on the cylindrical rod, the left end of the threaded rod is fixedly connected to the cylindrical rod of the jig main body, a spring length adjusting nut, a locking nut, and a locking nut compression deformer are sequentially installed on the threaded rod from left to right, the left end of the inner hole of the locking nut compression deformer is machined into an inner cone, the right end of the inner hole is machined with a thread, and is tightened with the threaded rod; the right end of the outer diameter of the locking nut compression deformer is machined into an external hexagonal structure for clamping with a force measuring wrench.

[0006] The main body of the mold is made of 45# steel.

[0007] The left end of the fixture body is a disc structure, which is used to fix it with a vise during testing.

[0008] The right end is a cylindrical rod with a diameter of 18.0 mm.

[0009] The threaded rod is used to simulate the component center rod. The threaded rod has the same material and thread size as the component center rod and is processed using Zr-4 alloy.

[0010] The left end of the threaded rod is fixedly connected to the cylindrical rod of the mold body using a pin.

[0011] Adjust the spring length to the size required by the component technology by screwing the spring length adjusting nut into the depth.

[0012] The lock nut compression deformer is made of H13 material and is heat treated.

[0013] The tightening of the locking nut compression deformer and the locking nut causes the locking nut to deform axially and radially, thereby increasing the friction of the locking nut thread connection and achieving the purpose of increasing the unloading torque.

[0014] The dynamometer wrench controls the unloading torque by tightening the lock nut and compressing the deformer.

[0015] The beneficial effects achieved by the present invention are:

[0016] This jig for the unloading torque test of the cobalt regulating rod assembly meets the requirements for component unloading torque testing. The jig was manufactured and processed according to the jig design. By using this jig for unloading torque testing, it was determined that during assembly, the unloading torque reached 5N·m-9N·m, and the tightening torque value was within this jig. During formal assembly, the locking nut compression deformer in this jig was used to deform the locking nut to increase the unloading torque. At the same time, the tightening torque was applied based on the test data to ensure that the unloading torque met the technical requirements. Multiple tests have verified that the data obtained after the jig test is accurate and meets the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the jig for the unloading torque test of the cobalt regulating rod assembly;

[0018] Figure 2 This is the structural diagram of the locking nut;

[0019] In the figure: 1-locking nut 2-spring length adjustment nut 3-threaded rod 4-spring 5-tire body 6-spring length measurement reference ring 7-pin 8-locking nut compression deformer 9-dynamometer wrench. DETAILED DESCRIPTION

[0020] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] After assembly, the cobalt adjustment rod assembly has a locking nut at the right end and a spring structure at the left end. The assembly requires the spring to be 38.1mm in size after assembly, and the locking nut unloading torque to be 5N·m to 9N·m. In the initial design, the locking nut unloading torque was achieved by the elastic force after the spring was compressed. However, after assembly and measurement, it was found that the unloading torque was 0, which did not meet the design requirements. Therefore, the present invention designs and manufactures an unloading torque test jig to ensure that the unloading torque of the locking nut meets the technical requirements. As can be seen from the locking nut structure diagram, the front end of the nut is a conical structure with a groove structure, and the internal thread is tightened with the thread of the center rod component.

[0022] The jig body 5 is made of 45# steel. The left end is a disc structure, which is used to fix with a vise during the test. A thread is processed in the middle section. The spring length measurement reference ring 6 is tightened and fixed here with a thread. The right end is a cylindrical rod with a diameter of 18.0mm. The spring 4 (exactly the same as the spring used for component assembly) is sleeved on the cylindrical rod. The threaded rod 3 is used to simulate the center rod of the component. The threaded rod 3 and the center rod of the component are exactly the same in material and thread size. They are processed using Zr-4 alloy. The left end of the threaded rod 3 is fixed to the cylindrical rod of the jig body 5 with a pin 7. The spring length adjustment nut 2, the locking nut 1 (exactly the same as the locking nut used for component assembly), and the locking nut compression deformer 8 are installed on the threaded rod 3 from left to right. The spring length is adjusted to the technical requirement size of the component by the depth of the spring length adjustment nut 2. The locking nut compression deformer 8 is made of H13 material and heat treated to ensure that it has sufficient strength. The left end of its inner hole is turned into an inner cone to match the outer cone structure of the locking nut 1. The right end of the inner hole is threaded and tightened with the threaded rod 3. Tightening locknut compression deformer 8 and locknut 1 with increased force causes axial and radial deformation of the locknut, thereby increasing the friction of the locknut's threaded connection and increasing the unloading torque. The right end of the outer diameter of locknut compression deformer 8 is machined into an external hexagonal structure for tightening with a dynamometer wrench 9. The dynamometer wrench 9 controls the unloading torque by tightening locknut compression deformer 8.

[0023] Based on the structural characteristics and unloading torque requirements of the cobalt adjusting rod assembly, an unloading torque test jig was designed and manufactured. The test jig consists of a locking nut, a spring length adjustment nut, a center rod dummy, a spring, a jig body, a spring length measurement reference ring, a pin, a locking nut compression deformer, and a force wrench. Testing with the unloading torque test jig determines the required tightening torque for assembly, completing the assembly.

[0024] According to the structural characteristics of the cobalt regulating rod assembly and the technical requirements of the unloading torque, an unloading torque test jig was designed, and the unloading torque test process scheme was designed. The required tightening torque for component assembly was obtained. Based on the data, the tightening process scheme for the locking nut during component assembly was determined to ensure that the unloading torque after component assembly reaches 5N·m-9N·m.

Claims

1. A cobalt regulating rod assembly unloading torque test fixture, characterized by: The left end of the mold body is a disc structure, and a thread is processed in the middle section of the mold body. The spring length measurement reference ring is tightened and fixed in the middle section with a thread. The right end of the mold body is a cylindrical rod, and the spring is sleeved on the cylindrical rod. The left end of the threaded rod is fixedly connected to the right end of the cylindrical rod of the mold body. The spring length adjustment nut, locking nut, and locking nut compression deformer are installed on the threaded rod from left to right. The left end of the inner hole of the locking nut compression deformer is turned into an inner cone, and the right end of the inner hole is threaded and tightened with the threaded rod; the right end of the outer diameter of the locking nut compression deformer is processed into an external hexagonal structure, which is used to clamp with a force measuring wrench; the spring length is adjusted to the technical requirement size of the component by the depth of the spring length adjustment nut.

2. The cobalt regulating rod assembly unloading torque test fixture according to claim 1, characterized in that: The main body of the mold is made of 45# steel.

3. The cobalt regulating rod assembly unloading torque test fixture according to claim 1, characterized in that: The left end of the mold body is a disc structure, which is used to fix it with a vise during testing.

4. The cobalt regulating rod assembly unloading torque test fixture according to claim 1, characterized in that: The right end of the mold body is a cylindrical rod with a diameter of 18.0 mm.

5. The cobalt regulating rod assembly unloading torque test jig according to claim 1, characterized in that: The threaded rod is used to simulate the component center rod. The threaded rod has the same material and thread size as the component center rod and is processed using Zr-4 alloy.

6. The cobalt regulating rod assembly unloading torque test jig according to claim 1, characterized in that: The left end of the threaded rod is fixedly connected to the right end of the cylindrical rod of the mold body using a pin.

7. The jig for testing the unloading torque of the cobalt regulating rod assembly according to claim 1, characterized in that: The lock nut compression deformer is made of H13 material and is heat treated.

8. The cobalt regulating rod assembly unloading torque test jig according to claim 1, characterized in that: The tightening of the locking nut compression deformer and the locking nut causes the locking nut to deform axially and radially, thereby increasing the friction of the locking nut thread connection and achieving the purpose of increasing the unloading torque.

9. The cobalt regulating rod assembly unloading torque test jig according to claim 1, characterized in that: The dynamometer wrench controls the unloading torque by tightening the lock nut and compressing the deformer.

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