A cobalt regulating rod assembly unloading torque test method

Abstract

The present invention belongs to the technical field of nuclear fuel element assembly process, and specifically relates to a cobalt adjustment rod assembly unloading torque test method. The locking nut and the locking nut compression deformer are screwed in sequence, the locking nut is tightly attached to the spring length adjustment nut, and the locking nut compression deformer is fitted to the locking nut; a torque wrench is used to apply a tightening torque to the locking nut compression deformer to deform the locking nut, and the tightening torque of the torque wrench is recorded; the locking nut is unloaded and the unloading torque is recorded; multiple tests are conducted, and the tightening torque and unloading torque values ​​are recorded, and finally the tightening torque value range when the unloading torque is 5N·m-9N·m is determined; when the assembly is formally assembled, the locking nut compression deformer is also used in conjunction with the locking nut, and the tightening torque data obtained from the test results is used for tightening. After multiple tests and verifications, the data obtained by the present invention is accurate and meets the use requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear fuel element assembly process, and in particular relates to an unloading torque test method for 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 industry chain. There is no foreign technology in the manufacturing process technology, and all of it is independently developed. The technical requirement for unloading torque in component design is 5N·m-9N·m. The unloading torque is an important technical indicator to ensure the overall structure and appearance size of the cobalt regulating rod assembly, and it is also crucial to ensure the safe operation of the component in the reactor. According to the component design drawings, the technical requirements are achieved by relying on spring elastic force. After assembly, the unloading is destroyed and the unloading torque is measured. The unloading torque is 0, which cannot meet this technical requirement. This component is produced in China for the first time. Its structure is quite different from other components. It is a special tooling and a nuclear fuel element. There are no reports on it in related fields. Summary of the invention

[0003] The purpose of the present invention is to provide a cobalt regulating rod assembly unloading torque test method, complete the unloading torque test method design, and after the unloading torque measured in the test meets the technical requirements, assemble the formal product 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 cobalt adjustment rod assembly unloading torque test method, the left end of the jig body is a disc structure, the middle section is processed with a thread, the spring length measurement reference ring is tightened and fixed here by using a thread, the right end is a cylindrical rod, 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, 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, the right end of the inner hole is processed with a thread, and is tightened with the threaded rod, the right end of the outer diameter of the locking nut compression deformer is processed into an outer hexagonal structure for clamping with a force measuring wrench;

[0006] The disc of the mold body is fixed on the vise; screw the spring length measurement reference ring to the upper end of the matching thread, tighten it, and ensure that the position does not change during the experiment, and then install the spring; fix the left end of the threaded rod to the cylindrical rod of the mold body; install the spring length adjustment nut, adjust the position of the spring length adjustment nut, and use a caliper to measure the distance between the upper end face of the spring length measurement reference ring and the lower end face of the spring length adjustment nut. This distance is the spring length. After it meets the technical requirements, the position of the spring length adjustment nut is no longer adjusted; screw in the locking nut and the locking nut compression deformer in turn, and tighten the locking nut and the spring The spring length adjustment nut is tight, and the locking nut compression deformer is fitted with the locking nut; a torque is applied to the locking nut compression deformer with a force measuring wrench to deform the locking nut, and the tightening torque of the force measuring wrench is recorded; the locking nut is unloaded and the unloading torque is recorded; multiple tests are conducted, and the tightening torque and unloading torque values ​​are recorded, and finally the tightening torque value range is determined when the unloading torque is 5N·m-9N·m; when the assembly is formally assembled, the locking nut compression deformer is also used in conjunction with the locking nut, and the tightening torque data obtained from the test results is used for tightening, thereby ensuring that the unloading torque of the assembly meets the technical requirements of the assembly.

[0007] The main body of the tire is made of 45# steel.

[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 exactly 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 by using a pin.

[0011] The spring length is adjusted 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 threaded connection and achieving the purpose of increasing the unloading torque.

[0014] The force measuring wrench controls the unloading torque by tightening the locking nut to compress the deformer.

[0015] After the technical requirement of 38.1 mm is reached, the position of the spring length adjustment nut is no longer adjusted.

[0016] The beneficial effects achieved by the present invention are:

[0017] The jig for the unloading torque test of the cobalt regulating rod assembly meets the requirements for the use of the unloading torque test of the assembly. According to the jig design plan, the jig is manufactured and processed. By using the jig to conduct a tightening torque determination test, it is determined that during assembly, the unloading torque reaches 5N·m-9N·m, and the tightening torque value. During formal assembly, the locking nut compression deformer in the jig is used to deform the locking nut to increase the unloading torque. At the same time, the tightening torque is loaded according to the test data to ensure that the unloading torque meets the technical requirements. After multiple tests and verifications, the data obtained after the jig test is accurate and meets the use requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the jig for the unloading torque test of the cobalt regulating rod assembly;

[0019] Figure 2 It is the structural diagram of the locking nut;

[0020] 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-force wrench. DETAILED DESCRIPTION

[0021] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] 1) Description of the locking structure of the cobalt adjustment rod assembly

[0023] After assembly, the right end of the cobalt adjustment rod assembly is a locking nut, and the left end has a spring structure. The assembly requires the size of the spring to be 38.1mm 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. After assembly measurement, it was found that the unloading torque was 0, which did not meet the design requirements. Therefore, the present invention uses an unloading torque test jig to perform an unloading torque test so that the unloading torque of the locking nut meets the technical requirements.

[0024] 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 in conjunction with the thread of the center rod component.

[0025] 2) Unloading moment fixture structure description

[0026] The jig body 5 is made of 45# steel, with a disc structure at the left end for fixing with a vise during testing. A thread is processed in the middle section, and a 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 18.0 mm. A spring 4 (exactly the same as the spring for assembly of the component) is put on the cylindrical rod. The threaded rod 3 is used to simulate the center rod of the component. The threaded rod 3 is exactly the same as the material and thread size of the center rod of the component and is processed with Zr-4 alloy. The left end of the threaded rod 3 is fixedly connected 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 for assembly of the component), and the locking nut compression deformer 8 are sequentially installed on the threaded rod 3 from left to right. The spring length is adjusted to the size required by the technical requirements of the component by the depth of the spring length adjustment nut 2 being screwed in. 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. The tightening of the locking nut compression deformer 8 and the locking nut 1 will cause the locking nut to deform axially and radially, thereby increasing the friction of the locking nut threaded connection and achieving the purpose of increasing the unloading torque. The right end of the outer diameter of the locking nut compression deformer 8 is processed into an outer hexagonal structure for the torque wrench 9 to cooperate and clamp. The torque wrench 9 controls the unloading torque by tightening the locking nut compression deformer 8.

[0027] The jig is used to test the unloading torque of the components, and the tightening torque required for assembly is measured based on the test results.

[0028] 3) Unloading torque test method

[0029] When the mold is in use, it is fixed vertically on a vise or other working platform.

[0030] a) The main disc of the tire is fixed on the vise.

[0031] b) Screw the spring length measurement reference ring to the upper end of the matching thread. After the reference ring is tightened and fixed, ensure that its position does not change during the experiment, and then install the spring;

[0032] c) Fix one end of the threaded rod to the main body of the mold using a pin.

[0033] d) Install the spring length adjusting nut, adjust the position of the spring length adjusting nut, and use a caliper to measure the distance between the upper end face of the spring length measuring reference ring and the lower end face of the spring length adjusting nut. This distance is the spring length. When it reaches the technical requirement of 38.1mm, the position of the spring length adjusting nut is no longer adjusted.

[0034] e) Screw in the locking nut and locking nut compression deformer in sequence, make sure the locking nut is tight against the spring length adjustment nut, and the locking nut compression deformer is tight against the locking nut to ensure that the conical surface is tight.

[0035] f) Use a dynamometer wrench to apply a certain tightening torque to the locking nut compression deformer to deform the locking nut, and record the tightening torque of the dynamometer wrench.

[0036] g) Unload the locking nut and record the unloading torque.

[0037] h) Conduct multiple tests, record the tightening torque and unloading torque values, and finally determine the tightening torque value range when the unloading torque is 5N·m-9N·m;

[0038] i) When formally assembling the components, the locking nut compression deformer is also used in conjunction with the locking nut, and the tightening torque data obtained from the test results is used for tightening, thereby ensuring that the component unloading torque meets the component technical requirements.

[0039] The unloading torque test jig was used to test and obtain the required tightening torque for assembly to complete the assembly. According to the structural characteristics of the cobalt adjustment rod assembly and the technical requirements of the unloading torque, the unloading torque test method design was completed using a special jig for the unloading torque test, and the required tightening torque for assembly was obtained. Based on the data, the tightening process plan for the locking nut during assembly was determined to ensure that the unloading torque after assembly reached 5N·m-9N·m.

Claims

1. A cobalt regulating rod assembly unloading torque test method, characterized in that: The left end of the mold body is a disc structure, and a thread is processed in the middle section. The spring length measurement reference ring is tightened and fixed at the thread of the middle section by using 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 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 processed with a thread and tightened with the threaded rod. The right end of the outer diameter of the locking nut compression deformer is processed into an outer hexagonal structure for clamping with a force measuring wrench. The disc of the mold body is fixed on the vise; the spring length measurement reference ring is screwed to the upper end of the matching thread, and after being tightened and fixed, the position is ensured not to change during the experiment, and then the spring is installed; the left end of the threaded rod is fixedly connected to the cylindrical rod of the mold body; the spring length adjustment nut is installed, the position of the spring length adjustment nut is adjusted, and the distance between the upper end face of the spring length measurement reference ring and the lower end face of the spring length adjustment nut is measured with a caliper. The distance is the spring length. After the spring length reaches the technical requirement, the position of the spring length adjustment nut is no longer adjusted; the locking nut and the locking nut compression deformer are screwed in turn, the locking nut is tightly attached to the spring length adjustment nut, and the locking nut compression deformer is fitted to the locking nut; a force measuring wrench is used to apply a tightening torque to the locking nut compression deformer to deform the locking nut, and the tightening torque of the force measuring wrench is recorded; Unload the locking nut and record the unloading torque; conduct multiple tests, record the tightening torque and unloading torque values, and finally determine the tightening torque value range when the unloading torque is 5N·m-9N·m; when formally assembling the component, also use the locking nut compression deformer in conjunction with the locking nut, and tighten it using the tightening torque data obtained from the test results, so as to ensure that the unloading torque of the component meets the technical requirements of the component.

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

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

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

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

6. The cobalt regulating rod assembly unloading torque test method according to claim 1, characterized in that: The spring length is adjusted to the size required by the component technology by screwing the spring length adjusting nut into the depth.

7. The cobalt regulating rod assembly unloading torque test method 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 method 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 threaded connection and achieving the purpose of increasing the unloading torque.

9. The cobalt regulating rod assembly unloading torque test method according to claim 1, characterized in that: The force measuring wrench controls the unloading torque by tightening the locking nut to compress the deformer.

10. The cobalt regulating rod assembly unloading torque test method according to claim 1, characterized in that: After the spring length reaches the technical requirement of 38.1 mm, the position of the spring length adjusting nut is no longer adjusted.

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