CN101335062B - Check neutron source drive mechanism - Google Patents

Abstract

The invention discloses a driving mechanism for a test neutron source. The device includes a power transmission mechanism and a test neutron source. The power transmission mechanism includes several parts such as motor, large pulley, limit switch and stopper. The control of the motor is achieved by changing the power supply polarity of the motor, that is, changing the rotation direction of the motor, and working with the diode and limit switch; the limit switch The switch is composed of a positive electrode, a negative electrode and an insulating sheet. The positive electrode and the negative electrode are fixed on the insulating sheet. They are in elastic contact. The hanging rope passes between the positive electrode and the negative electrode, and the lower part is fixed with a stop. The upper and lower parts of the hanging rope are The movement drives the stopper and disengages the elastic contact of the negative electrode from the positive electrode. The motor stops and the neutron source is in place. In the technical solution provided by the present invention, the neutron source is raised and lowered by changing the power supply polarity of the motor, and is matched with a diode and a limit switch. All control can be achieved with only one single-core cable, making the circuit very simple. At the same time, The neutron source is parked in an accurate location.

Description

Check neutron source drive mechanism

technical field

The invention belongs to the technical field of nuclear detection, and in particular relates to a driving mechanism for testing a neutron source.

Background technique

Due to the high dose, it is impossible to take out the nuclear detection system placed in the reactor at will for inspection. Therefore, it is a simple matter to hoist the inspection neutron source into the detection system in the reactor, and to conduct online inspection of the detector and its instrument working status. practical way. For example, in the detection device for fuel element damage detection used in sodium-cooled fast reactors, an inspection neutron source guide is installed, and the inspection neutron source is hoisted in from the neutron source guide if necessary to check whether the detection device is working normally. Usually, the driving mechanism of the neutron source for inspection is relatively simple, for example, a motor is used to drive the sling with the neutron source for inspection to move up and down, but the problem is that the positioning is inaccurate.

Contents of the invention

(1) Purpose of the invention

The invention mainly aims at the problem of inaccurate positioning of the neutron source driving device in the prior art, and provides a neutron source driving device with accurate positioning and simple control circuit.

(2) Technical solution

To achieve the above object, the present invention provides the following technical solutions.

A test neutron source driving device includes a power transmission mechanism and a test neutron source. The power transmission mechanism drives the test neutron source at one end of the rope to move up and down by driving the up and down movement of the suspension rope. The key is that the power transmission mechanism used in the present invention includes several parts such as motor, large pulley, limit switch and stopper, wherein the control of the motor is by changing the power supply polarity of the motor, that is, changing the direction of rotation of the motor, and cooperating with diodes and limit switch; the limit switch is composed of a positive electrode, a negative electrode and an insulating sheet, the positive electrode and the negative electrode are fixed on the insulating sheet, the two are in elastic contact, and the sling passes between the positive electrode and the negative electrode , the lower part of which is fixed with a block, the up and down movement of the sling drives the block and makes the elastic contact of the negative electrode out of contact with the positive electrode, the motor stops, and the neutron source is in place.

(3) Implementation effect

In the technical solution provided by the present invention, the neutron source is raised and lowered by changing the power supply polarity of the motor, and matched with a diode and a limit switch. Only one single-core cable can realize all control, making the circuit very simple. At the same time, The position where the neutron source is parked is accurate.

Description of drawings

Fig. 1 Schematic diagram of the driving mechanism of the inspection neutron source;

The winding mode of Fig. 2 sling;

Figure 3 Schematic diagram of limit switch structure;

Figure 4 Motor control circuit diagram.

Among them, 1, motor; 2, large pulley; 3, motor output shaft; 4, small pulley; 5, sealing gasket; 6, shielding plug; 7, circuit board; 8a, limit switch; 8b, limit switch; 9a , block; 9b, block; 10, sling; 11, shielding moderator; 12, test neutron source; 13, neutron source bucket; 14, gravity counterweight; 15, insulating sheet; 16, positive electrode ; 17, negative electrode; 18, relay; 19, rectifier diode and protection resistor.

Detailed ways

The technical solution of the present invention will be further elaborated below in conjunction with the accompanying drawings.

As shown in Figure 1, a driving mechanism for testing the neutron source is installed in the upper shielding layer of the reactor through a sealing gasket 5. During the testing operation, the testing device is used to lift the testing neutron source downward into the pile pit through the driving mechanism It is used to check whether the detectors and instruments are working normally. This operation is carried out remotely through the computer in the control room. Its specific structure is that the inspection neutron source 12 is installed in the shuttle-shaped bucket 13, the shuttle-shaped bucket 13 is tied on the suspension rope 10, and the upper and lower parts of the inspection neutron source in the bucket 13 are also equipped with neutron shielding moderators. 11. Its function is to prevent interference to the detector and damage to the staff in the reactor hall when the neutron source is parked in the shielding layer on the top of the reactor. Suspension rope 10 walks around big and small pulley 2,4, and its other end is tied with the gravitational counterweight 14 of neutron source bucket 13 equal weights, and purpose is to reduce the load of motor 1.

In its driving mechanism, the motor 1 drives the large pulley 2 to move through the motor output shaft 3 . In order to increase the frictional force between the pulley and the suspension rope 10 and prevent the overlapping of the suspension rope 10, this embodiment adopts the scheme of double pulleys, that is, a small pulley 4 is installed under the large pulley 2, and the suspension rope 10 is wound The way is as shown in accompanying drawing 2, that is, the suspension rope 10 goes around the bottom of the small pulley 4 and then goes around the big pulley 2 again.

As shown in Figure 1, two sets of stoppers 9a, 9b are fixed at the two tails of the suspension rope 10, and correspondingly, a circuit board 7 for controlling the movement of the motor is arranged at the bottom of the drive mechanism, and matched with the stoppers 9a, 9b The limit switches 8a, 8b.

As shown in Figure 3, the limit switches 8a, 8b are formed by riveting the positive electrode 16, the negative electrode 17 and the insulating sheet 15 on the circuit board together with a hollow rivet. Usually, the positive electrode 16 and the negative electrode 17 are in elastic contact. . The suspension rope 10 passes through the central hole of the hollow rivet, and drives the stopper 9a or 9b to move, the stopper makes the elastic contact of the negative electrode 17 disengage from the positive electrode 16, the motor 1 stops, and the neutron source 12 is checked to be in place.

The rotation of the motor 1 and the indication of the position of the test neutron source 12 are realized by the circuit shown in FIG. 4 . The circuit includes positive and negative power supplies, a relay 18, diodes D1, D2, D3, D4, red, yellow and green light-emitting diodes, limit switches 8a, 8b and the like. Through the computer control in the control room, the relay 18 is sucked in or turned on to change the polarity of the power supply, thereby changing the rotation direction of the motor to achieve the purpose of raising and lowering the neutron source. Utilizing the unidirectional conductivity of the diode, the control of the rising and falling of the neutron source is carried out independently. For example, when the relay 18 is connected to the positive power supply, the test neutron source 12 is raised, the diode D3 is turned on, and when the test neutron source 12 is raised to the right position, the limit switch 8a is turned off by the right stopper 9a, and the rise stops. When the relay 18 is connected to the negative power supply, the neutron source 12 is checked to descend, the diode D4 is turned on, the left stopper 9b disconnects the limit switch 8b, and the descending movement stops. At the same time, when the positive power supply is connected, D1 is turned on, and the green light-emitting diode is lit, indicating that the neutron source for inspection is parked in the shielding layer on the top of the stack. When the negative power supply is turned on, D2 is turned on, and the red light-emitting diode is lit, indicating that the neutron source for inspection has been hoisted into the detection device of the pile pit, and is in the state of source inspection. When the yellow bulbs are illuminated at the same time, it indicates that the test neutron source is moving towards the position. In order to protect the light-emitting diodes, the two light-emitting diodes are connected in series with a rectifier diode and a protection resistor 19 in the same direction.

In this embodiment, the inspection of the up and down of the neutron source 12 is realized by changing the polarity of the power supply of the motor 1, thereby changing the direction of rotation of the motor 1, and matching with a diode and a limit switch, all control can be realized with only one single-core cable , so that the circuit is very simple, and the parking position is accurate.

In addition, in order to prevent the strong gamma radiation of the reactor pit from harming the staff in the reactor hall, a stainless steel shielding plug 6 with a length of 100-150 mm is added.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (9)

1. An inspection neutron source driving device, comprising a power transmission mechanism and an inspection neutron source (12), the power transmission mechanism drives the inspection neutron source ( 12) Up and down movement, characterized in that: the power transmission mechanism includes a motor (1), a large pulley (2), limit switches (8a, 8b) and stoppers (9a, 9b), wherein the motor (1) Control is achieved by changing the polarity of the power supply of the motor (1), that is, changing the direction of rotation of the motor, and cooperating with diodes and limit switches (8a, 8b); the limit switches (8a, 8b) are controlled by positive electrodes (16 ), the negative electrode (17) and the insulating sheet (15), the positive electrode (16), the negative electrode (17) are fixed on the insulating sheet (15), the two are in elastic contact, and the sling (10) runs from the positive electrode (16 ), the negative electrode (17) passes through, and the lower part of the stopper (9a, 9b) is fixed, and the up and down movement of the sling (10) drives the stopper (9a, 9b) and makes the elastic contact of the negative electrode (17) Disconnect from the positive electrode (16), the motor (1) stops, and the neutron source (12) is in place. 2. The test neutron source driving device according to claim 1, characterized in that: the test neutron source (12) is installed in a shuttle-shaped bucket (13), and the shuttle-shaped bucket (13) is tied to a suspension rope (10) on. 3. The test neutron source driving device according to claim 2, characterized in that: neutron shielding moderators (11) are installed above and below the test neutron source in the bucket (13). 4. The inspection neutron source driving device according to claim 1, characterized in that: the other end of the sling (10) is tied with a gravity counterweight (14) equal in weight to the neutron source bucket (13) . 5. The inspection neutron source driving device according to claim 1, 2 or 4, characterized in that: a small pulley (4) is installed under the large pulley (2), and the lifting rope (10) is connected to the small pulley (4) Go around the bottom of the big pulley (2) again. 6. The driving device for testing neutron sources according to claim 1, characterized in that: a circuit board (7) for controlling the movement of the motor is arranged at the lower part of the power transmission mechanism. 7. The test neutron source driving device according to claim 6, characterized in that: the circuit board (7) includes positive and negative power supplies, relays (18), diodes (D1, D2, D3, D4), red , yellow, green light-emitting diodes, and limit switches (8a, 8b). 8. The test neutron source driving device according to claim 7, characterized in that: the red and green light-emitting diodes of the control circuit of the circuit board (7) are all connected in series with a rectifier diode and a protection resistor ( 19). the 9. The drive device for testing neutron sources according to claim 1, characterized in that: a stainless steel shielding plug (6) with a length of 100-150 mm is arranged at the lower part of the power transmission mechanism. the

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