A pressurized water reactor nuclear power plant load handler gripper unlocking device

Abstract

The present application relates to the technical fields of pressurized water reactor nuclear power plant loading and unloading machine debugging, and specifically discloses a pressurized water reactor nuclear power plant loading and unloading machine gripper unlocking device.The device comprises a hoop, a support plate and a connecting screw rod, the hoop is in quadrilateral plate structure, a circular hollow is arranged in the middle, and hoop screw holes are uniformly arranged at four corners; the support plate is in octagonal star plate structure, a quadrilateral hollow is arranged in the middle, and the support plate is arranged directly below the hoop, support plate screw holes are arranged at positions corresponding to the hoop screw holes; the connecting screw rod is provided with threads at both ends, the connecting screw rod penetrates the hoop screw holes and the support plate screw holes, the part protruding from the hoop screw holes is screwed by the hoop nut, and the part protruding from the support plate screw holes is screwed by the support plate nut, so that the hoop and the support plate are tightly connected.The device has compact structure, is convenient to disassemble and assemble, is easy to operate, and is safe and reliable.

Description

Technical Field

[0001] This invention belongs to the technical field of pressurized water reactor nuclear power plant loading and unloading machine commissioning, specifically relating to a gripper unlocking device for a pressurized water reactor nuclear power plant loading and unloading machine. Background Technology

[0002] The fuel loader is a key piece of equipment in the nuclear fuel operating system of a nuclear power plant. It consists of lifting, gripping, rotating, running, and positioning components, and can move along the X, Y, and Z axes to transport and manipulate the nuclear fuel assemblies within the reactor core. During the installation and commissioning phase of a nuclear power plant, the commissioning of the fuel loader is a crucial and specialized task, occupying approximately one month of the main commissioning timeline. The fuel loader's gripper directly contacts the nuclear fuel assemblies, and the "grabbing" and "detaching" operations are achieved by controlling the "opening" and "closing" of the gripper. To ensure the reliability of the gripper's gripping of nuclear fuel assemblies, the gripper control system, in addition to electrical interlocks, must also have a mechanical self-locking function to prevent accidental detachment of the gripper from the nuclear fuel assemblies during operation.

[0003] Due to the unique mechanical self-locking structure of the loading and unloading machine's gripper, the condition for releasing the self-lock is that the telescopic sleeve is weightless and the mechanical self-locking stroke is completed. Normally, the gripper needs to be lowered onto the upper tube seat of the nuclear fuel assembly and continue descending approximately 75mm to complete the self-locking stroke before the gripper's self-locking function is released, thus satisfying the gripper's "opening" and "closing" action conditions. At this point, the gripper's claws are within the upper tube seat frame of the nuclear fuel assembly, making it impossible to conduct gripper-related tests. The traditional approach is to use wooden blocks and the ground for support to release the gripper's mechanical self-lock, allowing for gripper-related tests. These methods are not only inefficient but also highly risky, easily leading to damage or deformation of the gripper. Summary of the Invention

[0004] The purpose of this invention is to provide an unlocking device for the gripper of a pressurized water reactor nuclear power plant loading and unloading machine, which enables the loading and unloading machine gripper to unlock its mechanical self-locking structure without the need for support from nuclear fuel assemblies or other objects. The gripper can be operated at any height to perform "opening" or "closing" actions, thereby improving the operating efficiency of the loading and unloading machine gripper.

[0005] The technical solution of the present invention is as follows: A gripper unlocking device for a pressurized water reactor nuclear power plant refueling machine, wherein the refueling machine gripper includes a gripper cylinder, a gripper support, and a gripper positioning pin. The device includes a clamp, a support plate, and a connecting screw. The clamp has a quadrilateral plate structure with a circular hollow in the center and clamp screw holes evenly distributed at the four corners. The clamp is located on the outside of the gripper cylinder. The support plate has an octagonal star plate structure with a quadrilateral hollow in the center and is positioned directly below the clamp. A support plate screw hole is provided at the position corresponding to the clamp screw hole; the support plate is inserted from the lower end of the loading and unloading machine gripper, forcing the positioning pin of the loading and unloading machine gripper to retract until the support plate is connected to the support of the loading and unloading machine gripper, at which point the loading and unloading gripper is in an unlocked state; the connecting screw has threads at both ends, and the connecting screw passes through the clamp screw hole and the support plate screw hole. The part protruding from the clamp screw hole is tightened by the clamp nut, and the part protruding from the support plate screw hole is tightened by the support plate nut, so that the clamp and the support plate are firmly connected.

[0006] The clamp can be split into two parts along the diagonal direction, making it easy to install the clamp on the outside of the grab cylinder of the loading and unloading machine.

[0007] The support plate has support grooves at one corner to support the gripper of the loading and unloading machine.

[0008] The support plate has positioning pin holes at its other opposite corners, and the positioning pin holes have limiting grooves to force the positioning pins of the loading and unloading machine grippers to retract.

[0009] The number of connecting screws is 4.

[0010] The limiting groove forces the locating pin of the loading and unloading machine's gripper to retract by 75 mm.

[0011] Both the clamps and the support plates are made of stainless steel.

[0012] The significant advantage of this invention lies in the fact that it restricts the positioning pin of the loading and unloading machine's gripper through a support plate and a clamp, thus keeping the gripper in an unlocked state. The following is a comparison of this invention with existing unlocking methods:

[0013] (1) The unlocking device is designed, installed and fixed according to the structural characteristics of the loading and unloading machine gripper, so that the gripper can be opened and closed at will, providing safe and convenient test conditions for the loading and unloading machine gripper related tests of a nuclear power plant reactor.

[0014] (2) The designed unlocking device does not interfere with the "opening" and "closing" of the gripper, and does not affect the operation of the telescopic sleeve within its full stroke range.

[0015] (3) The designed unlocking device is compact, easy to assemble and disassemble, simple to operate, safe and reliable. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a gripper unlocking device for a pressurized water reactor nuclear power plant loading and unloading machine according to the present invention;

[0017] Figure 2 This is a schematic diagram of the structure of the loading and unloading machine gripper using the device of the present invention;

[0018] Figure 3 This is an assembly diagram of a gripper unlocking device for a pressurized water reactor nuclear power plant loading and unloading machine, as described in this invention.

[0019] In the diagram: 1. Clamping nut; 2. Clamping clamp; 3. Connecting screw; 4. Support plate; 5. Support plate nut; 6. Loading and unloading machine gripper cylinder; 7. Loading and unloading machine gripper support; 8. Loading and unloading machine gripper positioning pin. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0021] like Figure 1-3 As shown, a gripper unlocking device for a pressurized water reactor nuclear power plant refueling machine includes a clamp 2, a support plate 4, and a connecting screw 3. The support plate 4 is generally octagonal in shape and has a plate-like structure with a quadrilateral hollowed-out center. Support screw holes are provided at the first, third, fifth, and seventh clockwise corners of the support plate 4, totaling four holes. Positioning pin holes are provided at the second and sixth clockwise corners of the support plate 4, with limiting grooves provided within the holes, totaling two holes. Support grooves are provided at the fourth and eighth clockwise corners of the support plate 4, totaling two grooves.

[0022] The clamp 2 has a quadrilateral plate structure with clamp screw holes at the four corners, totaling four screw holes. The clamp 2 has a circular hollow in the middle. A set of diagonal joints of the clamp 2 are tenon-and-mortise connected, which makes it easy to divide the clamp 2 into two parts and clamp it to the outside of the target gripper.

[0023] The connecting screw 3 is a rod-shaped structure with threads at both ends. The connecting screw 3 passes through the support screw hole and the clamp screw hole. The clamp nut 1 is screwed into the part of the connecting screw 3 that protrudes from the clamp screw hole, and the support plate nut 5 is screwed into the part of the connecting screw 3 that protrudes from the support screw hole, so as to fix the clamp 2 and the support plate 4 through the connecting screw 3. The number of connecting screw 3, clamp nut 1 and support plate nut 5 are all 4.

[0024] The working principle of this invention is as follows:

[0025] Step 1: The support plate 4 is fitted onto the outside of the loading and unloading machine gripper from the bottom. The positioning pin hole is fitted onto the positioning pin 8 of the loading and unloading machine gripper. The support plate 4 moves upward along the positioning pin 8 of the loading and unloading machine gripper until the support groove of the loading and unloading machine gripper support 7 comes into contact. The limiting groove in the positioning pin hole retracts the positioning pin 8 of the loading and unloading machine gripper by 75mm, so that the gripper is in the unlocked state.

[0026] Step 2: Place the clamp 2 on the outside of the grab cylinder 6 of the loading and unloading machine, align the tenons and mortises to make the clamp 2 securely connected;

[0027] Step 3: Connect the support plate 4 and the clamp 2 through the connecting screw 3, and tighten the clamp nut 1 and the support plate nut 5;

[0028] Step 4: Control the gripper to perform "retract" and "open" actions to verify that the device described in this invention can ensure that the gripper remains in the unlocked state.

[0029] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A gripper unlocking device for a pressurized water reactor nuclear power plant refueling machine, wherein the refueling machine gripper includes a gripper cylinder (6), a gripper support (7), and a gripper positioning pin (8), characterized in that: The device includes a clamp (2), a support plate (4), and a connecting screw (3). The clamp (2) has a quadrilateral plate structure with a circular hollow in the middle and clamp screw holes evenly distributed at the four corners. The clamp (2) is clamped to the outside of the grab cylinder (6) of the loading and unloading machine. The support plate (4) has an octagonal star plate structure with a quadrilateral hollow in the middle, and is placed directly below the clamp (2). The support plate screw holes are located at positions corresponding to the clamp screw holes. The support plate (4) is connected to the grab cylinder of the loading and unloading machine. The lower end is inserted, forcing the positioning pin (8) of the loading and unloading machine gripper to retract until the support plate (4) and the loading and unloading machine gripper support (7) are connected, and the loading and unloading gripper is in an unlocked state; the two ends of the connecting screw (3) are threaded, the connecting screw (3) passes through the clamp screw hole and the support plate screw hole, the part protruding from the clamp screw hole is tightened by the clamp nut (1), and the part protruding from the support plate screw hole is tightened by the support plate nut (5), so that the clamp (2) and the support plate (4) are firmly connected.

2. The pressurized water reactor nuclear power plant loading and unloading machine gripper unlocking device according to claim 1, characterized in that: The clamp (2) is split into two parts along the diagonal direction, so that it can be clamped on the outside of the grab cylinder (6) of the loading and unloading machine.

3. The pressurized water reactor nuclear power plant loading and unloading machine gripper unlocking device according to claim 1, characterized in that: The support plate (4) has support grooves at one corner to support the loading and unloading machine gripper support (7).

4. The pressurized water reactor nuclear power plant loading and unloading machine gripper unlocking device according to claim 1, characterized in that: The support plate (4) has positioning pin holes at the other opposite corners, and the positioning pin holes have limiting grooves to force the positioning pins (8) of the loading and unloading machine gripper to retract.

5. The gripper unlocking device for a pressurized water reactor nuclear power plant refueling machine according to claim 1, characterized in that: The number of connecting screws (3) is 4.

6. The pressurized water reactor nuclear power plant refueling machine gripper unlocking device according to claim 4, characterized in that: The limiting groove forces the loading and unloading machine's gripper positioning pin (8) to retract by 75 mm.

7. The pressurized water reactor nuclear power plant refueling machine gripper unlocking device according to claim 1, characterized in that: Both the clamp (2) and the support plate (4) are made of stainless steel.

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