Limiting device and high-temperature reactor control rod driving mechanism

Abstract

The invention relates to the technical field of high-temperature reactor control rod driving, in particular to a limiting device and a high-temperature reactor control rod driving mechanism. Comprising a limiting shell rotationally connected with a lead screw in the axis direction; and the push plate is arranged in the limiting shell, the lead screw penetrates through the push plate and is in threaded connection with the push plate, a guide rod parallel to the lead screw is arranged in the limiting shell, and the guide rod penetrates through the push plate. An external device can be connected with the lead screw so as to drive the lead screw to rotate, so that the push plate can move towards the limiting point or move away from the limiting point, and when the push plate reaches the limiting point, the elastic piece presses the contact into the limiting groove through the limiting rod set, and then the contact is clamped. When the contact is limited, the two limiting signal connecting wires are in contact connection through the contact to send out a limiting signal, and when the push plate moves from the limiting point to the direction away from the limiting point, the push plate hook pulls the limiting rod set to enable the contact to be separated from the limiting groove, so that the limiting signal connecting wires are disconnected.

Description

Technical Field

[0001] The present invention relates to the technical field of high temperature reactor control rod driving, and in particular to a limiting device and a high temperature reactor control rod driving mechanism. Background Art

[0002] The control rod drive mechanism of a high temperature gas-cooled reactor is a reactor control actuator designed according to the technical characteristics of a high temperature gas-cooled reactor, and includes a limit device, the function of which is to limit the control rod at a limit point to prevent the control rod from exceeding the travel range.

[0003] The existing limit device is that a movable electrode is screwed on the lead screw and a fixed motor is arranged on the limit shell. Both the movable electrode and the fixed electrode are connected with wiring, and the wiring connected to the movable electrode is wound on the lead screw. A guide rod is arranged through the movable electrode so that the movable electrode can move up and down with the rotation of the lead screw. If the movable electrode and the fixed electrode are in contact, it means that the control rod has reached the limit point. On the one hand, it can prevent the lead screw from rotating further. On the other hand, the two wirings are connected through the electrode, which can send a limit signal to the controller, so that the controller can control the driving mechanism accordingly.

[0004] However, with the existing limit device, the movable electrode may break the wiring or expose the wiring when it moves up and down, which may make it impossible to connect the wiring on the movable electrode and the fixed electrode, or may cause the wiring on the movable electrode and the fixed electrode to short-circuit. As a result, the controller cannot receive the correct limit signal, affecting the limit function of the control rod. Summary of the invention

[0005] In view of this, the present invention provides a limit device and a high temperature reactor control rod drive mechanism to solve the problem that the movable electrode may break the wiring or expose the wiring when moving up and down, thereby affecting the limit function.

[0006] In a first aspect, the present invention provides a limiting device, comprising:

[0007] The limiting shell is rotatably connected to a lead screw along the axial direction;

[0008] A push plate is arranged in the limit housing, the lead screw passes through the push plate and is screwed with the push plate, a guide rod parallel to the lead screw is arranged in the limit housing, and the guide rod passes through the push plate;

[0009] The limit assembly comprises a limit block group and a limit rod group, wherein the limit block group is connected to the inner wall of the limit shell, the limit block group comprises a limit groove and two limit signal wirings are arranged inside, the limit rod group is slidably arranged in the limit block group and the limit rod group is provided with a contact and an elastic member, and the push plate is provided with a push plate hook adapted to the limit rod group;

[0010] When the push plate moves toward the limit point, it is suitable for pushing the limit rod group to slide in the limit block group. When the push plate reaches the limit point, the elastic member presses the contact into the limit groove through the limit rod group and the contact contacts and connects the two limit signal wirings;

[0011] When the push plate moves away from the limiting point, the push plate hook is suitable for pulling the limiting rod group to make the contact disengage from the limiting groove.

[0012] The present application can be connected to the lead screw by an external device to drive the lead screw to rotate, so that the push plate can move toward or away from the limit point. When the push plate reaches the limit point, the elastic member presses the contact into the limit slot through the limit rod group, and limits the contact while making the two limit signal wirings contact and connect through the contact to send out a limit signal. When the push plate moves from the limit point to the direction away from the limit point, the push plate hook pulls the limit rod group to make the contact disengage from the limit slot, thereby disconnecting the limit signal wiring. Compared with the existing limit device, the present application cancels the original movable electrode and fixed electrode, which can avoid the limit signal wiring being pulled off or causing a short circuit. The limit signal wiring can be fixedly set in the limit slot, and the contact and the limit signal wiring can be connected to complete the connection.

[0013] In an optional embodiment, the limit assembly is divided into two groups, namely, an upper limit assembly and a lower limit assembly, which are respectively arranged on both sides of the push plate, and two push plate hooks are respectively arranged on both sides of the push plate. The upper limit position and the lower limit position of the push plate can be effectively controlled to ensure the precise positioning of the control rod at the extreme positions at both ends, avoid exceeding the travel range, and improve the safety of the system.

[0014] In an optional implementation, the limit block group includes:

[0015] The limit block is fixedly arranged on the inner wall of the limit shell, and the limit groove is arranged on the limit block; the limit block is fixedly arranged on the inner wall of the limit shell to ensure the stability of the position of the limit groove, reduce the limit error caused by loose or offset components, and improve the accuracy and reliability of the limit device.

[0016] The limiting hole is arranged on the limiting block along the axial direction of the limiting shell, and the opening faces the push plate; the limiting hole enables the first limiting rod to maintain linear sliding inside the limiting block, reducing lateral shaking and unnecessary friction, thereby reducing mechanical wear and extending the service life of the device.

[0017] The unhooking ramp is arranged on the limit block, and the unhooking ramp is located on the side of the limit slot close to the push plate and has an opening toward the push plate. Along the direction from the limit slot to the push plate, the unhooking ramp is away from the limit hole. The unhooking ramp can make the contact have a smooth transition when leaving the limit slot, avoiding sudden bounce or jitter, reducing false operation, and improving the stability of the limit signal.

[0018] A connecting hole is arranged on the limit block along the axial direction of the limit shell, and the limit hole is connected with the limit groove and the uncoupling ramp respectively through the connecting hole; the connecting hole can make the limit hole, the limit groove and the uncoupling ramp interconnected, ensuring that the contact can move smoothly during the uncoupling process, reducing the stagnation or poor operation caused by structural limitations.

[0019] The elastic member enables the contact to abut against the side wall of the connection hole when the contact is located between the limit groove and the unhooking ramp. The elastic member can ensure that the contact can reliably abut against the side wall of the connection hole when the contact is between the limit groove and the unhooking ramp, and will not be separated due to vibration or slight displacement, thereby ensuring the stability of the limit state.

[0020] In an optional embodiment, the side wall of the limit slot away from the push plate is a limit wall, and the limit wall is suitable for limiting the movement of the contact in the limit slot away from the push plate. The limit wall can effectively limit the movement of the contact away from the push plate, ensuring that the contact works in a predetermined position and avoiding the accuracy of the limit signal due to excessive movement. The contact is constrained by the limit wall to prevent it from deviating from the limit slot due to vibration, impact or excessive rebound of the elastic member, ensuring the reliable closing or disconnection of the limit signal and reducing the risk of false triggering or signal jitter.

[0021] In an optional embodiment, the side wall of the limit groove near the push plate is an electrode ramp, and two electrode rods are arranged on the electrode ramp, which are respectively connected to two limit signal wirings, and the contact is respectively contacted and connected with the two electrode rods when located in the limit groove. By arranging two electrode rods on the electrode ramp and respectively connecting them to the limit signal wirings, it is ensured that the contact can stably contact the electrode rods when located in the limit groove, thereby providing an accurate limit signal and avoiding signal loss or poor contact. Since the contact contacts the two electrode rods at the same time when in the limit groove, the signal trigger has a more stable electrical connection, which reduces false triggering caused by vibration, impact or environmental changes, and improves the accuracy of limit detection.

[0022] In an optional embodiment, the limiting rod group includes:

[0023] A first limiting rod, slidably disposed in the limiting hole;

[0024] A second limiting rod, slidably disposed in the connecting hole;

[0025] A rotating shaft, connected and arranged between the first limiting rod and the second limiting rod, the rotating shaft is fixedly connected to the first limiting rod and hinged to the second limiting rod, the elastic member is arranged on a side of the rotating shaft away from the push plate and connected and arranged between the first limiting rod and the second limiting rod, and the contact is arranged on a side of the second limiting rod close to the limiting groove;

[0026] A disengagement hook is arranged on a side of the second limiting rod close to the push plate;

[0027] When the contact abuts against the side wall of the connecting hole or is located in the limiting groove, the push plate hook and the disengagement hook overlap, and when the contact is located in the disengagement ramp, the push plate hook and the disengagement hook are disengaged.

[0028] The division of labor between the first limit rod and the second limit rod enables the limit rod group to slide smoothly, and the hinged connection of the rotating shaft ensures that the first limit rod and the second limit rod have good flexibility and stability during movement, avoiding jamming or malfunction due to excessive structural rigidity. The contact is installed on the second limit rod. When the first limit rod and the second limit rod slide into place, the contact can accurately enter the limit groove or abut the side wall of the connecting hole to ensure stable triggering of the limit signal and reduce signal failure or false triggering due to poor contact of the contact. The interaction between the disengagement hook and the push plate hook ensures that when the contact is in the disengagement ramp, the push plate hook and the disengagement hook can be smoothly disengaged, reducing mechanical damage caused by excessive resistance or structural jamming, and improving the service life of the limit mechanism. The elastic part can ensure that when the contact is located in the limit groove or the side wall of the connecting hole, the push plate hook and the disengagement hook can remain in an overlapping state. After the contact enters the disengagement ramp, the elastic part can push the second limit rod to reset, realize automatic disengagement, improve the degree of automation of the limit mechanism, and reduce the need for human intervention.

[0029] In an optional embodiment, a limiting member is provided on the limiting block, and the limiting member is located in the movement direction of the rotating shaft along the push plate. After the push plate hook and the disengaging hook are disengaged, the limiting member abuts against the rotating shaft, and is suitable for limiting the movement of the first limiting rod toward the push plate direction.

[0030] After the push plate hook and the disengagement hook are disengaged, the limiter contacts the rotating shaft to limit the movement of the first limiter rod, ensuring that it will not continue to move toward the push plate due to inertia or spring force, thereby avoiding malfunction or mechanical damage. Since the limiter provides fixed support for the first limiter rod, the movement range of the guide rod during the reset process can be effectively controlled, ensuring that the reset process of the limiter device is controllable and consistent, thereby improving the reliability of the long-term operation of the system.

[0031] In an optional embodiment, a wiring hole is provided on the limit block, the wiring hole is communicated with the limit groove, and the limit signal wiring is arranged in the wiring hole.

[0032] In a second aspect, the present invention further provides a high temperature reactor control rod drive mechanism, comprising:

[0033] Drive housing;

[0034] As the above-mentioned limiting device, the limiting device is arranged in the driving housing;

[0035] A driving motor is arranged in the driving housing and is a dual-shaft motor, wherein one output shaft is connected to the lead screw through a first gear set, and the other output shaft is connected to a sprocket through a second gear set, wherein a chain is arranged on the sprocket, and a control rod is connected to the chain;

[0036] The controller is electrically connected to the drive motor and the limit signal wiring respectively.

[0037] In an optional embodiment, a speed limiter is provided on the second gear set. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0039] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0040] Figure 2 This is a schematic diagram of the structure of the limit block group in Example 1 of the present invention;

[0041] Figure 3 This is a schematic diagram of the structure of the limit rod group of embodiment 1 of the present invention;

[0042] Figure 4 This is a schematic diagram of the structure when the contact of Embodiment 1 of the present invention is located at the limit point;

[0043] Figure 5 This is a schematic diagram of the structure when the contact is located between the limit groove and the unhooking ramp in Example 1 of the present invention;

[0044] Figure 6 This is a schematic diagram of the structure of the embodiment 1 of the present invention when the contact is located on the unhooking ramp;

[0045] Figure 7 This is a structural diagram of Example 2 of the present invention.

[0046] Description of reference numerals:

[0047] 10. Limit housing; 11. Lead screw; 12. Push plate; 13. Guide rod; 14. Limit signal wiring; 15. Contact; 16. Elastic member; 17. Push plate hook; 20. Limit block group; 21. Limit groove; 22. Limit block; 23. Limit hole; 24. Unhooking ramp; 25. Connecting hole; 26. Electrode rod; 27. Limit member; 28. Wiring hole; 30. Limit rod group; 31. First limit rod; 32. Second limit rod; 33. Rotating shaft; 34. Unhooking hook. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0049] Combine the following Figures 1 to 7 , describing an embodiment of the present invention.

[0050] Example 1

[0051] According to an embodiment of the present invention, there is provided a limiting device, comprising:

[0052] The limiting housing 10 is rotatably connected to a lead screw 11 along the axis direction; the lead screw 11 may be a worm lead screw 11. The cross section of the limiting housing 10 may be rectangular, circular or other shapes, but the present embodiment is not limited thereto.

[0053] The push plate 12 is arranged in the limiting shell 10, the lead screw 11 passes through the push plate 12 and is screwed with the push plate 12, and a guide rod 13 parallel to the lead screw 11 is arranged in the limiting shell 10, and the guide rod 13 passes through the push plate 12; the number of the guide rod 13 is at least one, and the number of the guide rods 13 in this embodiment can be two, but this embodiment is not limited to this.

[0054] The limit assembly includes a limit block group 20 and a limit rod group 30, the limit block group 20 is connected to the inner wall of the limit shell 10, the limit block group 20 includes a limit groove 21 and two limit signal wirings 14 are arranged inside the limit groove 21, the limit rod group 30 is slidably arranged in the limit block group 20 and the limit rod group 30 is provided with a contact 15 and an elastic member 16, and the push plate 12 is provided with a push plate hook 17 adapted to the limit rod group 30; the contact 15 can move in the limit block group 20 following the limit rod group 30, and the limit groove 21 is arranged on the movement path of the contact 15. It should be noted that the limit groove 21 is a one-way limit, that is, the limit groove 21 is located at the end point of the stroke of the contact 15, so that the limit groove 21 limits the movement of the contact 15 beyond its stroke range, and when the contact 15 returns from the limit groove 21 to the stroke range, it is not limited.

[0055] Specifically, the limit rod group 30 may include a push rod slidably arranged in the limit block group 20, one end of the push rod is connected to the push plate 12, and the other end is slidably arranged in the limit block group 20, the push rod is provided with a spring and a contact 15, the spring is arranged between the rod surface of the push rod and the contact 15, the contact 15 on the push rod moves in the limit block group 20 following the push rod, and the limit groove 21 is arranged on the movement path of the contact 15. When the push plate 12 drives the push rod to make the contact 15 move toward the limit groove 21, if the contact 15 on the push rod is located in the limit groove 21, the two limit signal wires 14 are connected through contact, and at this time, the limit groove 21 limits the contact 15; when the push plate 12 drives the push rod to make the contact 15 move away from the limit groove 21, the push rod pulls the contact 15 out of the limit groove 21.

[0056] When the push plate 12 moves toward the limit point, it is suitable for pushing the limit rod group 30 to slide in the limit block group 20. When the push plate 12 reaches the limit point, the elastic member 16 presses the contact 15 into the limit groove 21 through the limit rod group 30, and the contact 15 contacts and connects the two limit signal wirings 14. It should be noted that the limit point may not specifically refer to a specific position, but an associated position. Specifically, when the push plate 12 is at the limit point, the contact 15 is also at the limit point. These two limit points are not at the same position but indicate that the push plate 12 and the contact 15 are in the limit state at the same time. If a drive device is connected to the screw 11 through a transmission assembly, the drive device is also in the limit state at the same time. It can also be considered that the drive device has reached the limit point at this time.

[0057] When the push plate 12 moves away from the limiting point, the push plate hook 17 is suitable for pulling the limiting rod set 30 to make the contact 15 disengage from the limiting groove 21 .

[0058] The present application can be connected to the lead screw 11 by an external device, thereby driving the lead screw 11 to rotate, so that the push plate 12 can move toward or away from the limit point. When the push plate 12 reaches the limit point, the elastic member 16 presses the contact 15 into the limit slot 21 through the limit rod group 30, and limits the contact 15 while making the two limit signal wirings 14 contact and connect through the contact 15, thereby sending a limit signal. When the push plate 12 moves from the limit point to the direction away from the limit point, the push plate hook 17 pulls the limit rod group 30 to make the contact 15 disengage from the limit slot 21, thereby disconnecting the limit signal wiring 14. Compared with the existing limit device, the present application cancels the original movable electrode and fixed electrode, which can avoid the limit signal wiring 14 from being pulled off or causing a short circuit. The limit signal wiring 14 can be fixedly set in the limit slot 21, and the contact 15 can complete the connection when it contacts the limit signal wiring 14.

[0059] In an optional embodiment, the limit assembly is divided into two groups, namely, an upper limit assembly and a lower limit assembly, which are respectively arranged on both sides of the push plate 12, and two push plate hooks 17 are respectively arranged on both sides of the push plate 12. The upper limit position and the lower limit position of the push plate 12 can be effectively controlled to ensure the precise positioning of the control rod at the extreme positions at both ends, avoid exceeding the travel range, and improve the safety of the system.

[0060] The travel of the push plate 12 is limited between the upper limit position and the lower limit position. When the push plate 12 moves toward the upper limit assembly, after reaching the upper limit position, the upper limit assembly forms a limit on the push plate 12, so that the contact 15 in the upper limit assembly falls into the limit groove 21. When the push plate 12 returns to its travel range, the push plate hook 17 pulls the contact of the upper limit assembly out of the limit groove 21. The same applies when the push plate 12 moves toward the lower limit assembly.

[0061] In an optional implementation, the limit block group 20 includes:

[0062] The limit block 22 is fixedly arranged on the inner side wall of the limit shell 10, and the limit groove 21 is arranged on the limit block 22 and is arranged opposite to the limit hole 23; the limit block 22 is fixedly arranged on the inner side wall of the limit shell 10 to ensure the stability of the position of the limit groove 21, reduce the limit error caused by loose or offset components, and improve the accuracy and reliability of the limit device. Specifically, the limit block 22 can be connected by bolts, and the bolts are screwed between the limit shell 10 and the limit block 22.

[0063] The limiting hole 23 is arranged on the limiting block 22 along the axial direction of the limiting housing 10, and the opening faces the push plate 12; the limiting hole 23 can make the first limiting rod 31 keep sliding linearly inside the limiting block 22, reduce lateral shaking and unnecessary friction, thereby reducing mechanical wear and extending the service life of the device. Specifically, the limiting hole 23 can be a blind hole or a through hole.

[0064] The unhooking ramp 24 is arranged on the limit block 22 and is arranged opposite to the limit hole 23. The unhooking ramp 24 is located on the side of the limit slot 21 close to the push plate 12 and has an opening toward the push plate 12. Along the direction from the limit slot 21 to the push plate 12, the unhooking ramp 24 is away from the limit hole 23. The unhooking ramp 24 can make the contact 15 have a smooth transition when leaving the limit slot 21, avoid sudden bounce or jitter, reduce malfunction, and improve the stability of the limit signal.

[0065] The connecting hole 25 is arranged on the limiting block 22 along the axial direction of the limiting shell 10, and the limiting hole 23 is connected with the limiting groove 21 and the uncoupling ramp 24 respectively through the connecting hole 25; the connecting hole 25 can make the limiting hole 23, the limiting groove 21 and the uncoupling ramp 24 interconnected, ensuring that the contact 15 can move smoothly during the uncoupling process, reducing the stagnation or poor operation caused by structural limitations.

[0066] The elastic member 16 enables the contact 15 to abut against the side wall of the connection hole 25 when the contact 15 is located between the limiting groove 21 and the unhooking ramp 24. The elastic member 16 can ensure that the contact 15 can reliably abut against the side wall of the connection hole 25 when the contact 15 is between the limiting groove 21 and the unhooking ramp 24, and will not be separated due to vibration or slight displacement, thereby ensuring the stability of the limiting state.

[0067] In an optional embodiment, the side wall of the limit slot 21 away from the push plate 12 is a limit wall, and the limit wall is suitable for limiting the movement of the contact 15 in the limit slot 21 away from the push plate 12. The limit wall can effectively limit the movement of the contact 15 away from the push plate 12, ensuring that the contact 15 works in a predetermined position and avoiding the accuracy of the limit signal due to excessive movement. The contact 15 is constrained by the limit wall to prevent it from deviating from the limit slot 21 due to vibration, impact or excessive rebound of the elastic member 16, ensuring the reliable closing or disconnection of the limit signal and reducing the risk of false triggering or signal jitter.

[0068] In an optional embodiment, the side wall of the limit groove 21 near the push plate 12 is an electrode ramp, and the limit groove 21 will not limit the contact 15 when the contact 15 returns to its stroke, that is, moves toward the push plate 12. Two electrode rods 26 are arranged on the electrode ramp, which are respectively connected to the two limit signal wirings 14. When the contact 15 is located in the limit groove 21, it is respectively in contact with the two electrode rods 26. By arranging two electrode rods 26 on the electrode ramp and connecting them to the limit signal wirings 14, it is ensured that when the contact 15 is located in the limit groove 21, it can stably contact the electrode rods 26, thereby providing an accurate limit signal and avoiding signal loss or poor contact. Since the contact 15 contacts the two electrode rods 26 at the same time when it is in the limit groove 21, the signal trigger has a more stable electrical connection, reduces false triggering caused by vibration, impact or environmental changes, and improves the accuracy of limit detection.

[0069] In an optional embodiment, the limiting rod group 30 includes:

[0070] A first limiting rod 31, slidably disposed in the limiting hole 23;

[0071] A second limiting rod 32, slidably disposed in the connecting hole 25;

[0072] The rotating shaft 33 is connected and arranged between the first limiting rod 31 and the second limiting rod 32. The rotating shaft 33 is fixedly connected to the first limiting rod 31 and is hinged to the second limiting rod 32. The elastic member 16 is arranged on a side of the rotating shaft 33 away from the push plate 12 and connected and arranged between the first limiting rod 31 and the second limiting rod 32. The contact 15 is arranged on a side of the second limiting rod 32 close to the limiting groove 21.

[0073] A disengagement hook 34 is provided on the second limiting rod 32 at a side close to the push plate 12;

[0074] When the contact 15 abuts against the side wall of the connection hole 25 or is located in the limiting groove 21, the push plate hook 17 and the disengagement hook 34 overlap, and when the contact 15 is located in the disengagement ramp 24, the push plate hook 17 and the disengagement hook 34 are disengaged.

[0075] It should be noted that the limit signal wiring 14 can be set at the bottom end of the limit slot 21, and the depth of the unhooking ramp 24 (i.e., the extension direction from the unhooking ramp 24 to the limit hole 23) is greater than the depth of the limit slot 21, so that when the contact 15 is located in the unhooking ramp 24, the push plate hook 17 can be disengaged from the disengagement hook 34.

[0076] Specifically, the push plate hook 17 may be an inverted L-shaped plate having a first flat plate arranged horizontally, the disengagement hook 34 may be a second flat plate arranged horizontally, and the push plate hook 17 may move in the space formed by the disengagement ramp 24 when located at the limit block 22, and the contact 15 may be arranged at one end of the second limit rod 32 away from the push plate 12, and the elastic member 16 may be a spring, and the spring may be a compression spring. In the initial state, when the contact 15 is located in the disengagement ramp 24, under the action of the spring and the rotating shaft 33, the disengagement hook 34 is away from the space formed by the disengagement ramp 24 and is in a state of being disengaged from the push plate hook 17, and when the push plate 12 moves toward the limit point and the push plate 12 abuts against the bottom end of the first limit rod 31, the first flat plate may be located between the second flat plate and the contact 15. As the contact 15 moves toward the limiting groove 21 in the decoupling ramp 24, the second limiting rod 32 rotates around the rotating shaft 33 under the action of the spring and the rotating shaft 33 so that the second plate overlaps with the first plate, until the second plate always overlaps with the first plate when the contact 15 is located in the limiting groove 21. When the push plate 12 is away from the contact 15, since the second plate overlaps with the first plate, the first plate can pull the second plate to move, thereby pulling the contact 15 out of the limiting groove 21, until the contact 15 is located in the decoupling ramp 24, and the first plate is separated from the second plate. It should be noted that when the first plate and the second plate overlap and separate, the position depth of the contact 15 in the decoupling ramp 24 should be greater than the depth of the limiting groove 21.

[0077] The division of labor between the first limiting rod 31 and the second limiting rod 32 enables the limiting rod group 30 to slide smoothly, and the hinged connection of the rotating shaft 33 ensures that the first limiting rod 31 and the second limiting rod 32 have good flexibility and stability during movement, avoiding jamming or malfunction caused by excessive structural rigidity. The contact 15 is installed on the second limiting rod 32. When the first limiting rod 31 and the second limiting rod 32 slide into place, the contact 15 can accurately enter the limiting groove 21 or abut the side wall of the connecting hole 25, ensuring the stable triggering of the limiting signal and reducing signal failure or malfunction caused by poor contact of the contact 15. The interaction between the disengagement hook 34 and the push plate hook 17 ensures that when the contact 15 is in the disengagement ramp 24, the push plate hook 17 and the disengagement hook 34 can be smoothly disengaged, reducing mechanical damage caused by excessive resistance or structural jamming, and improving the service life of the limiting mechanism. The elastic member 16 can ensure that when the contact 15 is located on the side wall of the limiting groove 21 or the connecting hole 25, the push plate hook 17 and the disengagement hook 34 can maintain an overlapping state, and after the contact 15 enters the disengagement ramp 24, the elastic member 16 can push the second limiting rod 32 to reset, realize automatic disengagement, improve the degree of automation of the limiting mechanism, and reduce the need for human intervention.

[0078] In an optional embodiment, a limiting member 27 is provided on the limiting block 22, and the limiting member 27 is located in the movement direction of the rotating shaft 33 along the push plate 12. After the push plate hook 17 and the disengaging hook 34 are disengaged, the limiting member 27 abuts against the rotating shaft 33, which is suitable for limiting the movement of the first limiting rod 31 toward the push plate 12.

[0079] The limiting member 27 may be a baffle disposed in the limiting hole 23 , or a limiting step disposed on the limiting hole 23 . The limiting member 27 is disposed between the rotating shaft 33 and the push plate 12 .

[0080] After the push plate hook 17 and the disengagement hook 34 are disengaged, the limiter 27 abuts against the rotating shaft 33, limiting the movement of the first limiter rod 31, ensuring that it will not continue to move toward the push plate 12 due to inertia or spring force, thereby avoiding malfunction or mechanical damage. Since the limiter 27 provides fixed support for the first limiter rod 31, the movement range of the guide rod 13 during the resetting process can be effectively controlled, ensuring that the resetting process of the limiter device is controllable and consistent, thereby improving the reliability of the long-term operation of the system.

[0081] In an optional implementation, a wiring hole 28 is provided on the limit block 22 , the wiring hole 28 is communicated with the limit slot 21 , and the limit signal wiring 14 is provided in the wiring hole 28 .

[0082] Example 2

[0083] In the existing limit device, the spring-shaped cable is squeezed and broken during use. The reason is that the moving electrode reciprocates on the guide rod 13 and squeezes the spring-shaped cable to break. The cable breakage and the grounding short circuit of the exposed wire head cause the control rod indicator to flash out incorrectly. Because the limit position locks the DCS operation of the control rod, if the limit position short circuit occurs after the breakage, the position signal will be sent out incorrectly, causing the DCS to be unable to lift or insert the rod normally; in addition, the limit indicator flashes out at the limit position. The reason for the failure is that although the original limit mechanism has reached the limit position, the contact 15 structure is not firmly crimped.

[0084] In addition, the working environment of the control rod drive mechanism is high temperature and high pressure (150℃, 7Mpa). If the limit switch fails, the reactor needs to be shut down for maintenance. Therefore, a set of stable and reliable limit nodes is related to the safe and reliable operation of the reactor. Traditional integrated spring self-reset limit switches and travel switches will suffer mechanical structure damage and node adhesion failure under high temperature, high pressure and long-term compression.

[0085] Therefore, in order to ensure the reliable and stable operation of the limit device and to reduce the difficulty of maintenance work, it is necessary to design a reliable limit device according to the current size and structure of the control rod drive mechanism.

[0086] The present invention also provides a high temperature reactor control rod drive mechanism, comprising:

[0087] Drive housing;

[0088] As the above-mentioned limiting device, the limiting device is arranged in the driving housing;

[0089] The drive motor is arranged in the drive housing and is a dual-axis motor, wherein one output shaft is connected to the lead screw 11 through a first gear set, and the other output shaft is connected to a sprocket through a second gear set, and a chain is arranged on the sprocket, and a control rod is connected to the chain; the drive motor can be a stepper motor, and the first gear set and the second gear set can be used for transmission reduction, and the drive motor can be connected to the first gear set through a coupling.

[0090] The controller is electrically connected to the driving motor and the limit signal wiring 14 respectively.

[0091] In an optional embodiment, a speed limiter is provided on the second gear set. The speed limiter may be an eddy current speed limiter. The speed limiter may be provided on the gear shaft of the second gear set.

[0092] The lead screw 11 may be provided with a gear, and the drive motor is connected to the gear on the lead screw 11 through a first gear set. When the control rod reaches the limit point, the contact 15 is located in the limit slot 21, and the two limit signal wires 14 are connected. The controller obtains the limit signal and can control the drive motor. It should be noted that the limit signal generated by the upper limit assembly and the limit signal generated by the lower limit assembly should be distinguished so that the controller can perform correct control when receiving the two limit signals.

[0093] The driving mechanism may further include a control rod position measuring rotary transformer, and a gear shaft of the second gear set may be provided with a thread matched with the control rod position measuring rotary transformer, and the control rod position measuring rotary transformer is meshed with the thread on the gear shaft.

[0094] A chain storage box can be arranged below the drive housing to store the chain.

[0095] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A limiting device, characterized in that: include: The limiting housing (10) is rotatably connected to a lead screw (11) along the axial direction; A push plate (12) is arranged in the limiting shell (10), the lead screw (11) passes through the push plate (12) and is screwed to the push plate (12), and a guide rod (13) parallel to the lead screw (11) is arranged in the limiting shell (10), and the guide rod (13) passes through the push plate (12); A limit assembly, comprising a limit block group (20) and a limit rod group (30), wherein the limit block group (20) is connected to the inner wall of the limit shell (10), the limit block group (20) comprises a limit groove (21) and two limit signal wirings (14) are arranged inside the limit block group (21), the limit rod group (30) is slidably arranged in the limit block group (20) and the limit rod group (30) is provided with a contact (15) and an elastic member (16), and the push plate (12) is provided with a push plate hook (17) adapted to the limit rod group (30); When the push plate (12) moves toward the limit point, it is suitable for pushing the limit rod group (30) to slide in the limit block group (20); when the push plate (12) reaches the limit point, the elastic member (16) presses the contact (15) into the limit groove (21) through the limit rod group (30), and the contact (15) contacts and connects the two limit signal wirings (14); When the push plate (12) moves away from the limiting point, the push plate hook (17) is suitable for pulling the limiting rod group (30) so that the contact (15) is separated from the limiting groove (21).

2. The limiting device according to claim 1, characterized in that: The limit assembly consists of two groups, namely an upper limit assembly and a lower limit assembly. The upper limit assembly and the lower limit assembly are respectively arranged on both sides of the push plate (12). Two push plate hooks (17) are respectively arranged on both sides of the push plate (12).

3. The limiting device according to claim 1, characterized in that: The limit block group (20) comprises: A limit block (22) is fixedly arranged on the inner side wall of the limit shell (10), and the limit groove (21) is arranged on the limit block (22); A limiting hole (23) is arranged on the limiting block (22) along the axial direction of the limiting shell (10), and the opening faces the push plate (12); A decoupling ramp (24) is arranged on the limiting block (22) and is arranged opposite to the limiting hole (23); the decoupling ramp (24) is located on a side of the limiting groove (21) close to the push plate (12) and has an opening facing the push plate (12); along the direction from the limiting groove (21) to the push plate (12), the decoupling ramp (24) is away from the limiting hole (23); A connecting hole (25) is arranged on the limiting block (22) along the axial direction of the limiting shell (10); the limiting hole (23) is connected to the limiting groove (21) and the unhooking ramp (24) respectively through the connecting hole (25); the limiting groove (21) and the unhooking ramp (24) are located on the same side of the connecting hole (25); and the limiting groove (21) and the limiting hole (23) are on different sides of the connecting hole (25); The elastic member (16) enables the contact (15) to abut against the side wall of the connection hole (25) when the contact (15) is located between the limiting groove (21) and the unhooking ramp (24).

4. The limiting device according to claim 1, characterized in that: The side wall of the limiting groove (21) away from the push plate (12) is a limiting wall, and the limiting wall is suitable for limiting the movement of the contact (15) in the limiting groove (21) away from the push plate (12).

5. The limiting device according to claim 1, characterized in that: The side wall of the limiting groove (21) close to the push plate (12) is an electrode ramp, and two electrode rods (26) are arranged on the electrode ramp and are respectively connected to two limiting signal wirings (14). When the contact (15) is located in the limiting groove (21), it is respectively in contact with and connected to the two electrode rods (26).

6. The limiting device according to claim 3, characterized in that: The limiting rod group (30) comprises: A first limiting rod (31) slidably disposed in the limiting hole (23); A second limiting rod (32) is slidably disposed in the connecting hole (25); A rotating shaft (33) is connected and arranged between the first limiting rod (31) and the second limiting rod (32); the rotating shaft (33) is fixedly connected to the first limiting rod (31) and is hinged to the second limiting rod (32); the elastic member (16) is arranged on a side of the rotating shaft (33) away from the push plate (12) and connected and arranged between the first limiting rod (31) and the second limiting rod (32); and the contact (15) is arranged on a side of the second limiting rod (32) close to the limiting groove (21); A disengagement hook (34) is arranged on a side of the second limiting rod (32) close to the push plate (12); When the contact (15) abuts against the side wall of the connection hole (25) or is located in the limiting groove (21), the push plate hook (17) and the disengagement hook (34) overlap; when the contact (15) is located in the disengagement ramp (24), the push plate hook (17) and the disengagement hook (34) are disengaged.

7. The limiting device according to claim 6, characterized in that: A limiting member (27) is arranged on the limiting hole (23), and a limiting member (27) is arranged on the limiting block (22). The limiting member (27) is located in the movement direction of the rotating shaft (33) along the push plate (12). After the push plate hook (17) and the disengagement hook (34) are disengaged, the limiting member (27) abuts against the rotating shaft (33), and is suitable for limiting the movement of the first limiting rod (31) toward the push plate (12).

8. The limiting device according to claim 3, characterized in that: The limit block (22) is provided with a wiring hole (28), the wiring hole (28) is connected to the limit slot (21), and the limit signal wiring (14) is arranged in the wiring hole (28).

9. A high temperature reactor control rod drive mechanism, characterized in that: include: Drive housing; The limiting device according to any one of claims 1 to 8, wherein the limiting device is arranged in the driving housing; A drive motor is arranged in the drive housing and is a dual-shaft motor, wherein one output shaft is connected to the lead screw (11) via a first gear set, and the other output shaft is connected to a sprocket via a second gear set, wherein a chain is arranged on the sprocket, and a control rod is connected to the chain; The controller is electrically connected to the drive motor and the limit signal wiring (14) respectively.

10. The high temperature reactor control rod drive mechanism according to claim 9, characterized in that: The second gear set is provided with a speed limiter.

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