Crystal pulling furnace and control method for preventing crystal bar from resonance shaking

Abstract

The invention discloses a crystal pulling furnace and a control method for preventing a crystal bar from resonance shaking. The crystal pulling furnace comprises a furnace body used for melting raw materials into melt and a lifting mechanism located above the furnace body, and the lifting mechanism upwards lifts seed crystals connected to a seed crystal rope through the seed crystal rope and the crystal bar growing on the seed crystals based on the melt. The device further comprises a system for preventing the crystal bar from resonance shaking, and the system for preventing the crystal bar from resonance shaking comprises a triggering system and a seed crystal rope shaking limiting mechanism; when an earthquake occurs in an area which does not exceed a set distance away from the location of the crystal pulling furnace, the trigger system sends a control signal to the seed crystal rope shaking limiting mechanism, so that the seed crystal rope shaking limiting mechanism abuts against a first set position of the seed crystal rope, the vibration frequency of the crystal bar is changed, resonance between the earthquake frequency and the natural vibration frequency of the crystal bar is prevented, and the service life of the crystal pulling furnace is prolonged. Therefore, the shaking amplitude of the crystal bar is reduced, and the crystal bar is prevented from colliding with a thermal field in the furnace body or falling off.

Description

Technical Field

[0001] The present application relates to the field of crystal rod manufacturing, and more specifically to a crystal pulling furnace and a control method for preventing resonance shaking of a crystal rod. Background Art

[0002] At present, in a semiconductor single crystal furnace or a photovoltaic single crystal furnace, a sub-chamber is provided between the furnace body and the crystal rod lifting device, and a crystal rod lifting device is provided above the sub-chamber. The crystal rod lifting device slowly pulls out the single crystal rod by rotating and lifting the seed crystal rope.

[0003] When a large earthquake occurs, the seed crystal rope and crystal rod will shake severely and may collide with the thermal field in the furnace, causing the crystal rod to fall and the internal components of the single crystal furnace equipment to be damaged, resulting in significant economic losses and even major safety accidents. Summary of the invention

[0004] The present application is proposed to solve the above problems. According to one aspect of the present application, a crystal pulling furnace is provided. The crystal pulling furnace comprises:

[0005] A furnace body for melting raw materials into a melt;

[0006] A pulling mechanism located above the furnace body, the pulling mechanism pulling the seed crystal connected to the seed crystal rope upwards through the seed crystal rope, and the crystal rod grown on the seed crystal based on the melt; and,

[0007] A system for preventing a crystal rod from resonantly shaking includes a trigger system and a seed crystal rope shaking limiting mechanism; wherein, when an earthquake occurs in an area not exceeding a set distance from a crystal pulling furnace, the trigger system sends a control signal to the seed crystal rope shaking limiting mechanism, causing the seed crystal rope shaking limiting mechanism to abut against a first set position of the seed crystal rope to change the vibration frequency of the crystal rod, thereby reducing the shaking amplitude of the crystal rod.

[0008] In some embodiments of the present application, the seed rope shaking limiting mechanism includes:

[0009] A tuning fork-shaped seed crystal rope sway limiting fork, the seed crystal rope sway limiting fork comprising a connecting portion and two fork legs extending from the connecting portion in the same direction, the two fork legs being arranged at intervals to form a U-shaped slot portion between the two fork legs; and,

[0010] The driving mechanism is used to drive the seed crystal rope swing limiting fork to move. After receiving the control signal, the driving mechanism drives the seed crystal rope swing limiting fork to move so that the groove wall of the groove portion abuts against the first set position of the seed crystal rope.

[0011] In some embodiments of the present application, the two forked parts are also provided with seed rope introduction parts at one end away from the connecting part, and the distance between the two seed rope introduction parts gradually increases from the side close to the slot part to the side away from the slot part.

[0012] In some embodiments of the present application, the crystal pulling furnace further comprises:

[0013] A first slide rail is located between the furnace body and the lifting mechanism and is vertically arranged, and the seed crystal rope sway limiting fork is slidably assembled on the first slide rail;

[0014] The driving mechanism is used to drive the seed crystal rope sway limiting fork to slide to a position where the connecting portion is flush with the first set position of the seed crystal rope.

[0015] In some embodiments of the present application, the crystal pulling furnace further comprises:

[0016] A rotating shaft is rotatably connected to the connecting portion and slidably assembled on the first slide rail, the rotating shaft is horizontally arranged, and the extension direction of the two fork parts is perpendicular to the axis of the rotating shaft; the driving mechanism is also used to drive the seed crystal rope sway limiting fork to swing around the rotating shaft to a second set position, so that the slot part abuts against the first set position of the seed crystal rope; or,

[0017] A second slide rail is slidably assembled on the first slide rail and is horizontally arranged, and the seed crystal rope sway limiting fork is also slidably assembled on the second slide rail; the driving mechanism is also used to drive the seed crystal rope sway limiting fork to slide along the second slide rail to a third set position so that the slot portion abuts against the first set position of the seed crystal rope.

[0018] In some embodiments of the present application, the material of the seed rope sway limiting fork includes Teflon, polyoxymethylene resin, or a metal material provided with a coating.

[0019] According to the second aspect of the present application, there is provided a control method for preventing a crystal rod from shaking in resonance based on any of the above-mentioned crystal pulling furnaces, the control method for preventing a crystal rod from shaking in resonance comprising: when an earthquake occurs in an area not exceeding a set distance from the location of the crystal pulling furnace, a control signal is sent to a seed crystal rope shaking limiting mechanism so that the seed crystal rope shaking limiting mechanism abuts against a first set position of the seed crystal rope to change the vibration frequency of the crystal rod, thereby reducing the shaking amplitude of the crystal rod.

[0020] In some embodiments of the present application, when an earthquake occurs in an area not exceeding a set distance from the location of the crystal pulling furnace, a control signal is sent to the seed rope sway limiting mechanism, including:

[0021] When the magnitude of an earthquake that occurs in an area that is no more than a set distance from the crystal pulling furnace reaches a set magnitude, a control signal is sent to the seed rope sway limiting mechanism.

[0022] In some embodiments of the present application, when an earthquake occurs in an area not exceeding a set distance from the location of the crystal pulling furnace, a control signal is sent to the seed rope sway limiting mechanism, including:

[0023] When an earthquake occurs in an area not exceeding a set distance from the location of the crystal pulling furnace, the seismic shear wave frequency at the location of the crystal pulling furnace is obtained, and the inherent frequency of the crystal rod is calculated based on the distance between the center of gravity of the crystal rod and the current shaking fulcrum;

[0024] When the difference between the natural frequency of the crystal rod and the seismic shear wave frequency is less than a set threshold, a control signal is sent to the seed crystal rope sway limiting mechanism.

[0025] In some embodiments of the present application, the control method for preventing the crystal rod from resonantly shaking further includes:

[0026] Based on the seismic shear wave frequency and a set threshold, a target natural frequency of the crystal rod is determined; wherein the difference between the target natural frequency and the seismic shear wave frequency is greater than or equal to the set threshold;

[0027] Based on the target natural frequency, determining the distance between the center of gravity of the crystal rod and the target shaking fulcrum, and determining a first set position;

[0028] When the seed crystal rope swing limiting mechanism abuts against the first set position of the seed crystal rope, the natural frequency of the crystal rod is adjusted to the target natural frequency.

[0029] According to the crystal pulling furnace and the control method for preventing the crystal rod from shaking resonantly provided in the embodiments of the present application, a system for preventing the crystal rod from shaking resonantly is set, and when an earthquake occurs in an area not exceeding a set distance from the crystal pulling furnace, the trigger system sends a control signal to the seed crystal rope shaking limiting mechanism, so that the seed crystal rope shaking limiting mechanism abuts against the first set position of the seed crystal rope to change the vibration frequency of the crystal rod, prevent resonance between the earthquake frequency and the natural frequency of the crystal rod, thereby reducing the shaking amplitude of the crystal rod, preventing the crystal rod from colliding with the heat field in the furnace body or the crystal rod from falling, thereby preventing damage to components inside the furnace body and avoiding property damage and safety accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0031] Figure 1 This is a schematic diagram of the structure of a crystal pulling furnace shown in one embodiment of the present application;

[0032] Figure 2 and Figure 3 They are schematic top view structures of seed crystal rope sway limiting forks shown in different embodiments of the present application;

[0033] Figures 4 to 7 They are schematic diagrams of the structures of the crystal pulling furnaces shown in different embodiments of the present application;

[0034] Figure 8 The flowchart of one embodiment of the present application is to determine the first set position where the seed crystal rope sway limiting mechanism abuts against the seed crystal rope.

[0035] Reference numerals:

[0036] 10-furnace body 20-lifting mechanism

[0037] 21-Pulley 22-Winding machine

[0038] 30-seed rope 31-first setting position

[0039] 40-Crystal rod 41-Center of gravity of crystal rod

[0040] 50-seed crystal rope sway limiting fork 501-connecting part

[0041] 502- fork portion 503- slot portion

[0042] 504-seed rope introduction part 51-first slide rail

[0043] 52-rotating shaft 53-second slide rail

[0044] 60-Secondary Room DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of the present application more obvious, the example embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the example embodiments described herein. Based on the embodiments of the present application described in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.

[0046] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present application. However, it is apparent to those skilled in the art that the present application can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present application, some technical features well known in the art are not described.

[0047] It should be understood that the present application can be implemented in different forms and should not be interpreted as being limited to the embodiments set forth herein. On the contrary, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the present application to those skilled in the art.

[0048] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present application. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates another way. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, confirm the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0049] In order to thoroughly understand the present application, a detailed structure will be proposed in the following description to illustrate the technical solution proposed by the present application. The optional embodiments of the present application are described in detail as follows, but in addition to these detailed descriptions, the present application may also have other implementation methods.

[0050] At present, when a large earthquake occurs, the system or manual judgment will start the emergency shutdown operation, but it cannot prevent the crystal rod from shaking or even falling, causing the seed crystal rope and crystal rod to shake severely, and may collide with the thermal field in the furnace body, causing the crystal rod to fall, and the internal components of the single crystal furnace equipment will be damaged, resulting in major economic losses and even major safety accidents. That is, the existing single crystal furnace does not take into account the prevention of crystal rod shaking and falling caused by earthquakes.

[0051] To solve at least some of the technical problems in the above-mentioned related technologies, the present application proposes the following embodiments.

[0052] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0053] First, the crystal pulling furnace shown in the example of this application is introduced. Figure 1 , the crystal pulling furnace comprises:

[0054] A furnace body 10 for melting raw materials into a melt;

[0055] A pulling mechanism 20 is located above the furnace body 10, and the pulling mechanism 20 pulls the seed crystal connected to the seed crystal rope 30 upward through the seed crystal rope 30, and the crystal rod 40 grown on the seed crystal based on the melt; and

[0056] A system for preventing a crystal rod from resonantly shaking includes a trigger system and a seed crystal rope shaking limiting mechanism; wherein, when an earthquake occurs in an area not exceeding a set distance from a crystal pulling furnace, the trigger system sends a control signal to the seed crystal rope shaking limiting mechanism, so that the seed crystal rope shaking limiting mechanism abuts against a first set position 31 of the seed crystal rope 30, so as to change the vibration frequency of the crystal rod 40, thereby reducing the shaking amplitude of the crystal rod 40.

[0057] In the above scheme, by setting a system to prevent the crystal rod from resonant shaking, when the trigger system is an earthquake in an area not exceeding a set distance from the location of the crystal pulling furnace, a control signal is sent to the seed crystal rope sway limiting mechanism, so that the seed crystal rope sway limiting mechanism abuts against the first set position 31 of the seed crystal rope 30, so as to change the vibration frequency of the crystal rod 40, prevent the resonance between the earthquake frequency and the natural frequency of the crystal rod 40, thereby reducing the sway amplitude of the crystal rod 40, preventing the crystal rod 40 from colliding with the thermal field in the furnace body 10 or the crystal rod 40 from falling, thereby preventing damage to the components inside the furnace body 10, and avoiding material damage and safety accidents. That is, when it is determined that an earthquake occurs, the seed crystal rope sway limiting mechanism is triggered to limit the swaying of the seed crystal rope, change the natural frequency of the seed crystal rope 30, prevent resonance, and the swaying of the crystal rod 40 is very small, thereby protecting the crystal rod 40 and the thermal field in the furnace body 10.

[0058] The above structure is described in detail below with reference to the accompanying drawings.

[0059] It should be noted that the size of the above-mentioned set distance can be any preset value. As long as an earthquake occurs in an area not exceeding the set distance from the location of the crystal pulling furnace, the system for preventing the crystal rod from resonant shaking is activated. It should be noted that the distance from the location of the crystal pulling furnace can be the straight-line distance from the earthquake source to the location of the crystal pulling furnace. For example, the set distance can be any pre-set distance such as 1000km, 1500km, 2000km, etc.

[0060] For example, the trigger system may send a control signal to the seed rope shaking limiting mechanism only when the magnitude of an earthquake that occurs in an area not exceeding a set distance from the location of the crystal pulling furnace reaches a set magnitude. That is, only when a strong earthquake with a set magnitude or above occurs in an area not exceeding a set distance from the location of the crystal pulling furnace, which may cause the crystal ingot 40 of the crystal pulling furnace to resonate, will the system for preventing the crystal ingot from shaking due to resonance be activated.

[0061] Exemplarily, the set earthquake magnitude may be, for example, but not limited to, 5, 6, 7, etc. Exemplarily, the earthquake magnitude is set to 6, and only when a strong earthquake of 6 or above occurs in an area not exceeding the set distance from the location of the crystal pulling furnace, which may cause the crystal ingot 40 of the crystal pulling furnace to resonate, will the system for preventing the crystal ingot from resonant shaking be activated.

[0062] If the magnitude of an earthquake in an area not exceeding the set distance from the location of the crystal pulling furnace does not reach the set magnitude, that is, if the earthquake in an area not exceeding the set distance from the location of the crystal pulling furnace is a small-scale earthquake, since the crystal rod 40 of the crystal pulling furnace will not resonate, there is no need to start the system for preventing the crystal rod from resonantly shaking, that is, there is no need to send a control signal to the seed crystal rope shaking limiting mechanism. Therefore, the system for preventing the crystal rod from resonantly shaking is only started at necessary critical moments, avoiding unnecessary starting of the system for preventing the crystal rod from resonantly shaking.

[0063] When setting up the seed rope sway limiting mechanism, a variety of methods can be used, and some methods are introduced as examples below.

[0064] Exemplary, reference Figure 2 The seed rope sway limiting mechanism may include: a tuning fork-shaped seed rope sway limiting fork 50, and a driving mechanism. The seed rope sway limiting fork 50 includes a connecting portion 501, and two fork legs 502 extending from the connecting portion 501 in the same direction, and the two fork legs 502 are arranged at intervals to form a U-shaped slot portion 503 between the two fork legs 502. The driving mechanism is used to drive the seed rope sway limiting fork 50 to move. Specifically, after receiving the control signal, the driving mechanism drives the seed rope sway limiting fork 50 to move so that the slot wall of the slot portion 503 abuts against the first set position 31 of the seed rope 30. By locating the first setting position 31 of the seed crystal rope 30 in the U-shaped slot portion 503, the swing range of the seed crystal rope 30 at the first setting position 31 can be limited, and the swing center of the crystal rod 40 is moved down from the pulling mechanism 20 to the first setting position 31, thereby shortening the swing radius of the crystal rod 40, thereby increasing the natural frequency of the crystal rod 40 and facilitating avoiding the seismic shear wave frequency.

[0065] Exemplary, reference Figure 2 The gap width of the U-shaped slot portion 503 may be slightly larger than the diameter of the seed rope 30 , thereby improving the limiting effect on the seed rope 30 .

[0066] Exemplary, reference Figure 3 , the two fork parts 502 are respectively provided with seed rope introduction parts 504 at one end away from the connection part 501, and the spacing between the two seed rope introduction parts 504 gradually increases from the side close to the slot part 503 to the side away from the slot part 503. Specifically, the spacing between the two seed rope introduction parts 504 on the side close to the slot part 503 is equal to the width of the slot part 503, while the spacing between the two seed rope introduction parts 504 on the side away from the slot part 503 is greater than the width of the slot part 503. By providing the seed rope introduction parts 504 at the opening of the seed rope sway limiting fork 50, the opening of the seed rope sway limiting fork 50 is made larger, so that when the seed rope sway limiting fork 50 is driven to move, it is convenient to introduce the seed rope 30 into the U-shaped slot part 503.

[0067] It should be understood that the arrangement of the seed rope swing limiting fork 50 is not limited to the above-mentioned arrangement, and other arrangements may be adopted. In addition, the seed rope swing limiting mechanism moves to the first setting position 31 abutting against the seed rope 30 to change the vibration frequency of the crystal rod 40, and is not limited to the above-mentioned tuning fork-shaped seed rope swing limiting fork 50. Other structures may be adopted, for example, an openable limiting ring may be adopted.

[0068] Exemplary, reference Figure 4 and Figure 6 The crystal pulling furnace may further include: a first slide rail 51 vertically arranged between the furnace body 10 and the pulling mechanism 20, on which the seed rope sway limiting fork 50 is slidably mounted; and a driving mechanism is used to drive the seed rope sway limiting fork 50 to slide to a position where the connection portion 501 is flush with the first set position 31 of the seed rope 30. After the seed rope sway limiting fork 50 slides to a position where the connection portion 501 is flush with the first set position 31 of the seed rope 30, the seed rope 30 may be introduced into the U-shaped slot portion 503 by, for example, but not limited to, rotating or sliding the seed rope sway limiting fork 50.

[0069] By setting a vertically extending first slide rail 51 between the furnace body 10 and the pulling mechanism 20, the seed crystal rope sway limiting fork 50 is slidably assembled on the first slide rail 51, so that the seed crystal rope sway limiting fork 50 can be driven to move along the vertical direction on the first slide rail 51. When the determined first set position 31 changes, the position of the seed crystal rope sway limiting fork 50 can be adjusted in time to improve the shockproof effect.

[0070] It should be noted that when the connection portion 501 is at the position flush with the first setting position 31 of the seed rope 30, the seed rope sway limiting fork 50 can guide the first setting position 31 of the seed rope 30 into the U-shaped slot portion 503 by means such as but not limited to rotation, sliding, etc. That is, whether the connection portion 501 is flush with the first setting position 31 of the seed rope 30 is mainly determined based on whether the seed rope sway limiting fork 50 can guide the first setting position 31 of the seed rope 30 into the U-shaped slot portion 503 by means such as but not limited to rotation, sliding, etc. at the current position of the connection portion 501. If the first setting position 31 of the seed rope 30 can be guided into the U-shaped slot portion 503, it means that the connection portion 501 is flush with the first setting position 31 of the seed rope 30, otherwise, it means that the connection portion 501 is not flush with the first setting position 31 of the seed rope 30.

[0071] In some embodiments, when no earthquake occurs in an area not exceeding a set distance from the location of the crystal pulling furnace, the seed rope sway limiting fork 50 can also be disengaged from the seed rope 30, so as not to interfere with the movement of the seed rope 30 and the crystal rod 40. Thus, the system for preventing the crystal rod from resonantly shaking shown in the present application is only triggered and started when an earthquake occurs in an area not exceeding a set distance from the location of the crystal pulling furnace, and when no earthquake occurs in an area not exceeding a set distance from the location of the crystal pulling furnace, the seed rope sway limiting fork 50 can be disengaged from the seed rope 30, so that the system for preventing the crystal rod from resonantly shaking is in an untriggered state. Regarding the way to achieve contact and disengagement between the seed rope sway limiting fork 50 and the seed rope 30, a variety of ways can be used, and some ways are introduced as examples below.

[0072] Exemplary, reference Figure 4 The crystal pulling furnace may further include: a rotating shaft 52 rotatably connected to the connecting portion 501 and slidably mounted on the first slide rail 51, the rotating shaft 52 being arranged horizontally, and the extending direction of the two fork legs 502 being arranged perpendicularly to the axis of the rotating shaft 52. The driving mechanism is also used to drive the seed rope sway limiting fork 50 to swing around the rotating shaft 52 to a second set position, so that the slot portion 503 abuts against the first set position 31 of the seed rope 30.

[0073] Therefore, when the connecting portion 501 is flush with the first setting position 31 of the seed crystal rope 30, the driving mechanism can drive the seed crystal rope swing limiting fork 50 to swing around the rotating shaft 52 to the second setting position, and guide the first setting position 31 of the seed crystal rope 30 into the U-shaped slot portion 503, so that the slot portion 503 abuts against the first setting position 31 of the seed crystal rope 30, which is convenient for operation.

[0074] When the system for preventing the crystal rod from resonantly shaking stops being used, the driving mechanism can drive the seed rope sway limiting fork 50 to the second set position and swing around the rotation axis 52 to the set position where the seed rope sway limiting fork 50 is out of contact with the seed rope 30. For example, when the system for preventing the crystal rod from resonantly shaking stops being used, the driving mechanism can drive the seed rope sway limiting fork 50 to the second set position and swing around the rotation axis 52 to a vertically placed position, so that the seed rope sway limiting fork 50 does not interfere with the normal operation of the seed rope 30 at all.

[0075] In other embodiments, reference Figure 5 It is also possible to not use the above-mentioned first slide rail 51, and only set the above-mentioned rotating shaft 52, and set the rotating shaft 52 at a fixed position, that is, the rotating shaft 52 cannot slide in the vertical direction.

[0076] Exemplary, reference Figure 6The crystal pulling furnace may also include: a second slide rail 53 slidably assembled on the first slide rail 51 and arranged horizontally, and the seed crystal rope swing limiting fork 50 is also slidably assembled on the second slide rail 53; the driving mechanism is also used to drive the seed crystal rope swing limiting fork 50 to slide along the second slide rail 53 to a third set position, so that the slot portion 503 abuts against the first set position 31 of the seed crystal rope 30.

[0077] Therefore, when the connecting portion 501 is flush with the first setting position 31 of the seed crystal rope 30, the driving mechanism can drive the seed crystal rope sway limiting fork 50 to slide along the second slide rail 53 to the third setting position, and guide the first setting position 31 of the seed crystal rope 30 into the U-shaped slot portion 503, so that the slot portion 503 abuts against the first setting position 31 of the seed crystal rope 30, which is convenient for operation.

[0078] When the system for preventing the crystal rod from resonant shaking stops being used, the driving mechanism can drive the seed crystal rope swing limiting fork 50 to the third set position and slide along the second slide rail 53 to the set position where the seed crystal rope swing limiting fork 50 is out of contact with the seed crystal rope 30.

[0079] In other embodiments, reference Figure 7 It is also possible to not use the above-mentioned first slide rail 51, and only set the above-mentioned second slide rail 53, and set the second slide rail 53 at a fixed position, that is, the second slide rail 53 cannot slide in the vertical direction.

[0080] Regarding the type of driving mechanism, a variety of methods can be used to drive the seed rope sway limiting fork 50 to move. For example, a pneumatic driving mechanism or an electric driving mechanism can be used as the driving mechanism of this embodiment.

[0081] Regarding the material of the seed rope sway limiting fork 50, a variety of materials can be used, and some examples are introduced below.

[0082] Exemplarily, the material of the seed crystal rope swing limiting fork 50 may include Teflon or POM resin (polyoxymethylene resin). Due to the property of Teflon or POM resin surface being clean and not easy to lose granular debris, the seed crystal rope swing limiting fork 50 and the seed crystal rope can be prevented from losing granular debris during the mutual friction between the swinging of the seed crystal rope, thereby contaminating the raw materials and melt in the furnace body 10.

[0083] In other embodiments, the material of the seed crystal rope swing limiting fork 50 also includes a metal material with a coating, that is, the material of the seed crystal rope swing limiting fork 50 is a composite material. For example, the main body material of the seed crystal rope swing limiting fork 50 can be a metal material, and a Teflon coating or a resin coating can be provided on the surface of the main body of the seed crystal rope swing limiting fork 50 to prevent the seed crystal rope swing limiting fork 50 from dropping granular debris during the mutual friction between the seed crystal rope swing limiting fork 50 and the seed crystal rope, thereby contaminating the raw materials and melt in the furnace body 10.

[0084] Exemplary, reference Figure 1 A sub-chamber 60 may be provided between the pulling mechanism 20 and the furnace body 10 , the seed rope 30 passes through the sub-chamber 60 and is connected between the pulling mechanism 20 and the crystal rod 40 , and the seed rope swing limiting mechanism may be located in the sub-chamber 60 .

[0085] There are many ways to set the lifting mechanism 20. Some of the ways are described as follows. Figure 1 The pulling mechanism 20 may include a pulley 21 located above the furnace body 10, and the seed crystal rope 30 is suspended on the pulley 21 and then wound on the winder 22. The seed crystal rope 30 may be connected to the seed crystal and the crystal rod 40 grown on the seed crystal by means such as but not limited to a seed crystal chuck. During the crystal pulling process, the winder 22 rotates to wind the seed crystal rope 30, rotates the growing single crystal and slowly pulls it out of the melt liquid surface in the furnace body 10 until the crystal rod 40 is completely grown.

[0086] There are many ways to set up the furnace body 10. For example, a rotatable crucible is provided in the furnace body 10, and the crucible is used to contain the above-mentioned raw materials and melt, and a heating device is provided on the outside of the crucible. During the crystal growth process, the seed crystal clamped by the seed crystal chuck and the crucible generally rotate in opposite directions. The pulley 21 in the pulling mechanism 20 is generally 5-8m away from the melt surface of the crystal pulling, and the suspended seed crystal rope 30 and the crystal rod 40 form a pendulum structure.

[0087] There are many ways to set up the trigger system. As long as it can receive or detect information related to the occurrence of an earthquake, it is within the protection scope of the trigger system of this embodiment. For example, the trigger system may include, but is not limited to, a weight sensor, a camera, etc. For specific detection methods, please refer to the description of the control method for preventing the crystal rod from resonant shaking below.

[0088] Embodiment 2

[0089] Another embodiment of the present application further provides a control method for preventing a crystal rod from resonantly shaking based on any of the above-mentioned crystal pulling furnaces, referring to Figure 1 The control method for preventing the crystal rod from resonating and shaking includes:

[0090] When an earthquake occurs in an area not exceeding a set distance from the crystal pulling furnace, a control signal is sent to the seed rope sway limiting mechanism so that the seed rope sway limiting mechanism abuts against the first set position 31 of the seed rope 30 to change the vibration frequency of the crystal rod 40, thereby reducing the sway amplitude of the crystal rod 40.

[0091] When an earthquake occurs in an area not exceeding a set distance from the location of the crystal pulling furnace, a control signal is sent to the seed crystal rope sway limiting mechanism, so that the seed crystal rope sway limiting mechanism abuts against the first set position 31 of the seed crystal rope 30, so as to change the vibration frequency of the crystal rod 40, prevent resonance between the earthquake frequency and the natural frequency of the crystal rod 40, thereby reducing the sway amplitude of the crystal rod 40, preventing the crystal rod 40 from colliding with the thermal field in the furnace body 10 or the crystal rod 40 from falling, thereby preventing damage to the components inside the furnace body 10, and avoiding material damage and safety accidents. That is, by limiting the sway of the seed crystal rope, the effect of reducing the sway of the crystal rod 40 and damaging the thermal field is achieved.

[0092] The above steps are described in detail below with reference to the accompanying drawings.

[0093] It should be noted that the method of sending the control signal to the seed crystal rope sway limiting mechanism can be through an automatic judgment triggering method or a manual starting method.

[0094] Exemplary, reference Figure 1 When an earthquake occurs in an area not exceeding a set distance from the crystal pulling furnace, a control signal is sent to the seed rope sway limiting mechanism, which may include:

[0095] When the magnitude of an earthquake that occurs in an area not exceeding the set distance from the location of the crystal pulling furnace reaches the set magnitude, a control signal is sent to the seed rope shaking limiting mechanism. That is, only when a strong earthquake with a set magnitude or above occurs in an area not exceeding the set distance from the location of the crystal pulling furnace, which may cause the crystal rod 40 of the crystal pulling furnace to resonate, will the system for preventing the crystal rod from resonating and shaking be activated.

[0096] Exemplarily, the set earthquake magnitude may be, for example, but not limited to, 5, 6, 7, etc. Exemplarily, the earthquake magnitude is set to 6, and only when a strong earthquake of 6 or above occurs in an area not exceeding the set distance from the location of the crystal pulling furnace, which may cause the crystal ingot 40 of the crystal pulling furnace to resonate, will the system for preventing the crystal ingot from resonant shaking be activated.

[0097] If the magnitude of an earthquake in an area not exceeding the set distance from the location of the crystal pulling furnace does not reach the set magnitude, that is, if the earthquake in an area not exceeding the set distance from the location of the crystal pulling furnace is a small-scale earthquake, since the crystal rod 40 of the crystal pulling furnace will not resonate, there is no need to start the system for preventing the crystal rod from resonantly shaking, that is, there is no need to send a control signal to the seed crystal rope shaking limiting mechanism. Therefore, the system for preventing the crystal rod from resonantly shaking is only started at necessary critical moments, avoiding unnecessary starting of the system for preventing the crystal rod from resonantly shaking.

[0098] Exemplary, reference Figure 1 When an earthquake occurs in an area not exceeding a set distance from the crystal pulling furnace, a control signal is sent to the seed rope sway limiting mechanism, which may include:

[0099] When an earthquake occurs in an area not exceeding a set distance from the location of the crystal pulling furnace, the seismic shear wave frequency of the location of the crystal pulling furnace is obtained, and the inherent frequency of the crystal rod 40 is calculated based on the distance between the center of gravity of the crystal rod 40 and the current shaking fulcrum;

[0100] When the difference between the natural frequency of the crystal rod 40 and the seismic shear wave frequency is smaller than a set threshold, a control signal is sent to the seed rope sway limiting mechanism.

[0101] When an earthquake occurs, P waves (longitudinal waves) and S waves (transverse waves) occur. P waves (longitudinal waves) have a fast propagation speed, low energy, high frequency, and cause less damage to surface objects. S waves have a slow propagation speed, high energy, low frequency, and cause greater damage to surface objects. In the event of a large earthquake, the high-frequency components of transverse waves are easily absorbed, depending on the depth and intensity of the epicenter, as well as the density and elastic modulus of the propagating rock. The frequency of the seismic transverse waves transmitted to the location of the crystal pulling furnace is generally low, reaching a range of 0.1-0.3Hz. Generally, the larger the earthquake, the greater the energy released, the larger the propagation range, and the lower the frequency fe of the seismic transverse waves transmitted to the location of the crystal pulling furnace.

[0102] By obtaining the seismic shear wave frequency at the location of the crystal pulling furnace, and based on the distance between the center of gravity of the crystal rod 40 and the current shaking fulcrum, the self-frequency of the crystal rod 40 is calculated. If the difference between the self-frequency of the crystal rod 40 and the seismic shear wave frequency is less than the set threshold, it means that the self-frequency of the crystal rod 40 is close to the seismic shear wave frequency, which is easy to cause resonance between the earthquake and the swing of the crystal rod 40, so that the swing amplitude of the crystal rod 40 is large, that is, the crystal rod 40 will shake severely, and there is a possibility that the crystal rod 40 will shake severely and fall. At this time, a control signal can be sent to the seed crystal rope shaking limiting mechanism to change the vibration frequency of the crystal rod 40, prevent the resonance between the seismic frequency and the self-frequency of the crystal rod 40, thereby reducing the swing amplitude of the crystal rod 40, preventing the crystal rod 40 from colliding with the thermal field in the furnace body 10 or the crystal rod 40 from falling, thereby preventing damage to the components inside the furnace body 10 and avoiding material damage and safety accidents.

[0103] It should be noted that the seismic shear wave frequency can be a single value, but often the seismic shear wave frequency is a seismic shear wave frequency range. At this time, the difference between the inherent frequency of the crystal rod 40 and the seismic shear wave frequency calculated above is: the minimum value of all differences between the inherent frequency of the crystal rod 40 and the seismic shear wave frequency range.

[0104] Exemplary, reference Figure 1 and Figure 8 The control method for preventing the crystal rod from resonantly shaking may also include:

[0105] Based on the seismic shear wave frequency and the set threshold, a target natural frequency of the crystal rod 40 is determined; wherein the difference between the target natural frequency and the seismic shear wave frequency is greater than or equal to the set threshold;

[0106] Based on the target natural frequency, determining the distance between the center of gravity of the crystal rod and the target shaking fulcrum, and determining a first set position;

[0107] When the seed crystal rope swing limiting mechanism abuts against the first set position 31 of the seed crystal rope 30 , the natural frequency of the crystal rod 40 is adjusted to the target natural frequency.

[0108] The target self-frequency of the crystal rod 40 is calculated based on the seismic shear wave frequency and the set threshold value, so that the difference between the target self-frequency and the seismic shear wave frequency is greater than or equal to the set threshold value, and then the distance between the center of gravity of the crystal rod 40 and the target shaking fulcrum is determined based on the target self-frequency, so as to determine the target shaking fulcrum of the crystal rod 40, and the first set position 31 where the seed crystal rope shaking limiting mechanism abuts against the seed crystal rope 30 is determined based on the distance between the center of gravity of the crystal rod 40 and the target shaking fulcrum, so that when the seed crystal rope shaking limiting mechanism abuts against the first set position 31 of the seed crystal rope 30, the self-frequency of the crystal rod 40 can be adjusted to the target self-frequency. Since the difference between the target self-frequency and the seismic shear wave frequency is greater than or equal to the set threshold value, that is, the target self-frequency and the seismic shear wave frequency are not close, the seismic shear wave frequency is difficult to cause the crystal rod 40 to resonate, so that it is difficult to resonate between the earthquake and the crystal rod 40, thereby reducing the shaking amplitude of the crystal rod 40. In the above manner, the accurate first set position 31 can be determined to improve the earthquake-proof effect.

[0109] It should be noted that the seismic shear wave frequency can be a single value, but often the seismic shear wave frequency is a seismic shear wave frequency range. At this time, the difference between the target intrinsic frequency of the crystal rod 40 and the seismic shear wave frequency calculated above is: the minimum value of all differences between the target intrinsic frequency of the crystal rod 40 and the seismic shear wave frequency range.

[0110] There are many ways to obtain the seismic shear wave frequency at the location of the crystal pulling furnace. Some of the methods are introduced as examples below.

[0111] Exemplary, reference Figure 1 , to obtain the seismic shear wave frequency at the location of the crystal pulling furnace, which may include:

[0112] Real-time sampling of the tension information of the seed crystal rope 30 on the crystal rod 40, and obtaining the seismic longitudinal wave information of the location of the crystal pulling furnace based on the tension information;

[0113] Determine the earthquake intensity at the location of the crystal pulling furnace based on seismic longitudinal wave information;

[0114] Based on the earthquake intensity, estimate the seismic shear wave frequency at the location of the crystal pulling furnace.

[0115] By sampling the tension information of the seed rope 30 on the crystal rod 40 in real time, when an earthquake occurs, it will be reflected in the change of the tension of the seed rope 30 on the crystal rod 40. For example, when an earthquake occurs, the shaking amplitude and shaking mode of the crystal rod 40 will be different from that in normal operation, which will be reflected in the change of the tension information of the seed rope 30 on the crystal rod 40. Therefore, based on the tension information of the seed rope 30 on the crystal rod 40, the seismic longitudinal wave information of the location of the crystal pulling furnace can be obtained. Then, based on the seismic longitudinal wave information, the seismic intensity of the location of the crystal pulling furnace is determined, and then the seismic shear wave frequency of the location of the crystal pulling furnace is estimated based on the seismic intensity, so that a rough seismic shear wave frequency can be estimated in advance. Since the propagation speed of the longitudinal wave of an earthquake is greater than the propagation speed of the transverse wave of an earthquake, when an earthquake occurs, the longitudinal wave of the earthquake will reach the location of the crystal pulling furnace first. Therefore, the transverse wave frequency of the earthquake when the transverse wave reaches the location of the crystal pulling furnace can be estimated in advance. Based on the estimated transverse wave frequency of the earthquake, the first set position 31 of the seed crystal rope 30 can be determined, and the system for preventing the crystal rod from shaking resonantly can be triggered in advance. Therefore, when the transverse wave of the earthquake reaches the location of the crystal pulling furnace, the system for preventing the crystal rod from shaking resonantly has been triggered in place, and the resonance of the crystal rod 40 caused by the transverse wave of the earthquake can be overcome in the first place, thereby improving the earthquake-proof effect.

[0116] The above-mentioned real-time sampling of the tension information of the seed crystal rope 30 on the crystal rod 40 can be carried out in a variety of ways. For example, a weighing sensor on a crystal pulling furnace can be used to collect the tension of the seed crystal rope 30 on the crystal rod 40, and when the crystal rod 40 hardly swings, the tension of the seed crystal rope 30 on the crystal rod 40 is used as the basis for calculating the weight of the crystal rod 40. When an earthquake occurs or the crystal rod 40 shakes violently, the shaking of the crystal rod 40 will have an acceleration in the same or opposite direction as the gravity, so that the tension of the seed crystal rope 30 on the crystal rod 40 measured by the weighing sensor is no longer equal to the weight of the crystal rod 40, that is, the tension information of the seed crystal rope 30 on the crystal rod 40 will reflect whether an earthquake has occurred to a certain extent.

[0117] Exemplary, reference Figure 1 , obtain the seismic shear wave frequency where the crystal pulling furnace is located, and may also include:

[0118] Sampling the shaking amplitude information of the crystal rod 40 in real time, and determining the earthquake intensity at the location of the crystal pulling furnace based on the shaking amplitude information;

[0119] Based on the earthquake intensity, estimate the seismic shear wave frequency at the location of the crystal pulling furnace.

[0120] By taking advantage of the characteristic that when the shear wave of an earthquake resonates with the crystal rod 40, the shaking amplitude of the crystal rod 40 will be increased. By real-time sampling of the shaking amplitude information of the crystal rod 40, and determining the earthquake intensity at the location of the crystal pulling furnace based on the shaking amplitude information, and then estimating the shear wave frequency of the earthquake at the location of the crystal pulling furnace based on the earthquake intensity, it is possible to obtain a relatively accurate shear wave frequency of the earthquake at the moment of the crystal pulling furnace, so as to calculate the accurate first set position 31 of the seed rope 30, so that the natural frequency of the changed crystal rod 40 will not resonate with the shear wave frequency of the earthquake, thereby improving the earthquake-proof effect.

[0121] There are many ways to sample the shaking amplitude information of the crystal ingot 40. For example, a camera device aligned with the crystal ingot 40 can be provided in the crystal pulling furnace. The camera device can be, for example, but not limited to, a CCD camera. The camera device takes pictures in real time to sample the shaking amplitude information of the crystal ingot 40.

[0122] It should be understood that the method for obtaining the seismic shear wave frequency at the location of the crystal pulling furnace is not limited to the method shown above. In addition, other methods can be used. For example, the seismic shear wave frequency at the location of the crystal pulling furnace can also be obtained based on the earthquake occurrence information transmitted in real time by the earthquake early warning agency. Earthquake early warning agencies in various places obtain information on whether an earthquake has occurred and the earthquake area in real time, and send it to the important facilities under their jurisdiction. The control center of the crystal pulling furnace can control the system to prevent the crystal rod from resonant shaking based on the professional data obtained from the earthquake early warning agency, which is specifically reflected in whether the trigger system sends a control signal to the seed crystal rope sway limiting mechanism, so that the seed crystal rope sway limiting mechanism abuts against the first set position of the seed crystal rope.

[0123] refer to Figure 1 , the distance from the center of gravity 41 of the crystal rod 40 to the pulley 21 above the seed rope 30 is L1. At this time, the current swing fulcrum of the crystal rod 40 is the pulley 21. At this time, the distance between the center of gravity of the wafer 40 and the current swing fulcrum is L1. The natural frequency f of the crystal rod 40 is related to the distance L1 between the center of gravity of the crystal rod 40 and the current swing fulcrum. At this time, the natural frequency f1 of the crystal rod 40 can be calculated using the following formula:

[0124]

[0125] Here, g represents the acceleration due to gravity.

[0126] Exemplarily, the distance L1 from the center of gravity 41 of the crystal rod 40 to the pulley 21 above the seed rope 30 may be between 4 and 6 m, and the natural frequency f1 of the crystal rod 40 is 0.20-0.25 Hz.

[0127] When an earthquake occurs in an area no more than a set distance from the crystal pulling furnace, when the seismic shear wave frequency fe at the location of the crystal pulling furnace is close to the intrinsic frequency f1 of the crystal rod 40, the crystal rod 40 and the seed rope 30 will resonate, and the crystal rod 40 will soon begin to shake violently, causing damage to the thermal field such as the heating device in the furnace body 10. In severe cases, accidents such as falling rods may occur.

[0128] refer to Figure 1 When an earthquake occurs within a range not exceeding a set distance from the location of the crystal pulling furnace, the trigger system sends a control signal to the seed rope sway limiting mechanism, so that the seed rope sway limiting mechanism abuts against the first set position 31 of the seed rope 30, and the sway fulcrum of the crystal rod 40 is adjusted from the pulley 21 to the first set position 31, so as to shorten the distance between the center of gravity of the crystal rod 40 and the sway fulcrum, for example, at this time, the distance L2 between the first set position 31 and the center of gravity 41 of the crystal rod 40, so as to change the vibration frequency of the crystal rod 40. The changed natural frequency f2 of the crystal rod 40 can be calculated by the following formula:

[0129]

[0130] Since L1 is greater than L2, f2 is greater than f1, thereby achieving the purpose of changing the natural frequency of the crystal rod 40, preventing resonance between the earthquake frequency and the natural frequency of the crystal rod 40, thereby reducing the shaking amplitude of the crystal rod 40, preventing the crystal rod 40 from colliding with the heat field in the furnace body 10 or the crystal rod 40 from falling, thereby preventing damage to the components inside the furnace body 10 and avoiding material damage and safety accidents.

[0131] Exemplary, reference Figure 1 The first set position 31 can be located between 0.5m and 3m below the pulley 21, and the distance L2 between the first set position 31 and the center of gravity 41 of the crystal rod 40 can be controlled within 3m, thereby shortening the distance from the center of gravity 41 of the crystal rod 40 to the shaking fulcrum (seed crystal rope shaking limiting fork 50), shortening the swing radius of the crystal rod 40, and appropriately increasing the inherent frequency f of the crystal rod 40 seed crystal rope 30 to avoid the low seismic shear wave frequency fe of large earthquakes and extremely large earthquakes, avoid the same shear wave frequency as that of large earthquakes, avoid resonance, and ensure that the crystal rod 40 shakes little and does not fall.

[0132] Exemplarily, the crystal rod 40 may be, for example but not limited to, a silicon crystal rod 40 , the diameter of the crystal rod 40 may be 300 mm, and the first set position 31 may be located at a position 1.5 m below the pulley 21 in the lifting mechanism 20 .

[0133] The present application has been described through the above-mentioned embodiments, but it should be understood that the above-mentioned embodiments are only for the purpose of example and illustration, and are not intended to limit the present application to the scope of the described embodiments. In addition, it can be understood by those skilled in the art that the present application is not limited to the above-mentioned embodiments, and more variations and modifications can be made according to the teachings of the present application, and these variations and modifications all fall within the scope of protection claimed by the present application. The scope of protection of the present application is defined by the attached claims and their equivalents.

Claims

1. A crystal pulling furnace, characterized in that: include: A furnace body, used for melting raw materials into a melt; A pulling mechanism, located above the furnace body, and pulling the seed crystal connected to the seed crystal rope upwards through the seed crystal rope, and the crystal rod grown on the seed crystal based on the melt; as well as, A system for preventing a crystal rod from resonantly shaking includes a trigger system and a seed crystal rope shaking limiting mechanism; wherein, when an earthquake occurs in an area not exceeding a set distance from the crystal pulling furnace, the trigger system sends a control signal to the seed crystal rope shaking limiting mechanism, so that the seed crystal rope shaking limiting mechanism abuts against a first set position of the seed crystal rope to change the vibration frequency of the crystal rod, thereby reducing the shaking amplitude of the crystal rod.

2. The crystal pulling furnace according to claim 1, characterized in that: The seed crystal rope sway limiting mechanism comprises: A tuning fork-shaped seed crystal rope sway limiting fork, the seed crystal rope sway limiting fork comprising a connecting portion and two fork legs extending from the connecting portion in the same direction, the two fork legs being arranged at intervals to form a U-shaped slot portion between the two fork legs; and The driving mechanism is used to drive the seed crystal rope swing limiting fork to move. After receiving the control signal, the driving mechanism drives the seed crystal rope swing limiting fork to move so that the groove wall of the groove portion abuts against the first set position of the seed crystal rope.

3. The crystal pulling furnace according to claim 2, characterized in that: The two forked parts are also respectively provided with seed crystal rope introduction parts at one end away from the connecting part, and the distance between the two seed crystal rope introduction parts gradually increases from the side close to the slot part to the side away from the slot part.

4. The crystal pulling furnace according to claim 2, characterized in that: Also includes: A first slide rail is located between the furnace body and the lifting mechanism and is vertically arranged, and the seed crystal rope sway limiting fork is slidably assembled on the first slide rail; The driving mechanism is used to drive the seed crystal rope swing limiting fork to slide to a position where the connecting portion is flush with the first set position of the seed crystal rope.

5. The crystal pulling furnace according to claim 4, characterized in that: Also includes: A rotating shaft is rotatably connected to the connecting portion and slidably assembled on the first slide rail, the rotating shaft is horizontally arranged, and the extension direction of the two fork parts is perpendicular to the axis of the rotating shaft; the driving mechanism is also used to drive the seed crystal rope sway limiting fork to swing around the rotating shaft to a second set position, so that the slot portion abuts against the first set position of the seed crystal rope; or, The second slide rail is slidably assembled on the first slide rail and is arranged horizontally, and the seed crystal rope sway limiting fork is also slidably assembled on the second slide rail; the driving mechanism is also used to drive the seed crystal rope sway limiting fork to slide along the second slide rail to a third set position, so that the slot portion abuts against the first set position of the seed crystal rope.

6. The crystal pulling furnace according to claim 2, characterized in that: The material of the seed crystal rope sway limiting fork includes Teflon, polyoxymethylene resin, or a metal material with a coating.

7. A control method for preventing a crystal rod from resonantly shaking in a crystal pulling furnace according to any one of claims 1 to 6, characterized in that: include: When an earthquake occurs in an area not exceeding a set distance from the crystal pulling furnace, a control signal is sent to the seed crystal rope sway limiting mechanism, so that the seed crystal rope sway limiting mechanism abuts against a first set position of the seed crystal rope to change the vibration frequency of the crystal rod, thereby reducing the sway amplitude of the crystal rod.

8. The method for preventing the crystal rod from resonantly shaking according to claim 7, characterized in that: When an earthquake occurs in an area not exceeding a set distance from the location of the crystal pulling furnace, a control signal is sent to the seed rope sway limiting mechanism, including: When the magnitude of an earthquake that occurs in an area that is no more than the set distance from the location of the crystal pulling furnace reaches a set magnitude, the control signal is sent to the seed rope sway limiting mechanism.

9. The method for preventing the crystal rod from resonantly shaking according to claim 7, characterized in that: When an earthquake occurs in an area not exceeding a set distance from the location of the crystal pulling furnace, a control signal is sent to the seed rope sway limiting mechanism, including: When an earthquake occurs in an area not exceeding the set distance from the location of the crystal pulling furnace, the seismic shear wave frequency at the location of the crystal pulling furnace is obtained, and the inherent frequency of the crystal rod is calculated based on the distance between the center of gravity of the crystal rod and the current shaking fulcrum; When the difference between the natural frequency of the crystal rod and the seismic shear wave frequency is less than a set threshold, the control signal is sent to the seed crystal rope sway limiting mechanism.

10. The method for preventing the crystal rod from resonantly shaking according to claim 9, characterized in that: Also includes: Based on the seismic shear wave frequency and the set threshold, determining the target natural frequency of the crystal rod; wherein the difference between the target natural frequency and the seismic shear wave frequency is greater than or equal to the set threshold; Based on the target natural frequency, determining the distance between the center of gravity of the crystal rod and the target shaking fulcrum, and determining the first set position; When the seed crystal rope swing limiting mechanism abuts against the first set position of the seed crystal rope, the natural frequency of the crystal rod is adjusted to the target natural frequency.

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