Wear monitoring method for ball screw in crucible lifting mechanism of CZ silicon single crystal furnace

Abstract

The present application proposes a method for monitoring the wear of a ball screw in a crucible lifting mechanism of a vertical silicon single crystal furnace, and belongs to the technical field of fault diagnosis of silicon single crystal equipment. The method includes the following steps: installing a wire encoder and a programmable logic controller on the crucible lifting mechanism; using the wire encoder and the programmable logic controller to draw a first relationship curve between the ideal number of rotations and the ideal displacement, and a second relationship curve between the actual number of rotations and the actual displacement on the display and control end; setting a first wear threshold and a second wear threshold according to the first relationship curve, comparing the second relationship curve with the first wear threshold and the second wear threshold, and updating the comparison result in real time, thereby realizing real-time monitoring of the wear of the ball screw. The present application can solve the problem of the risk of failure in the crucible lifting mechanism due to untimely monitoring of the wear of the ball screw.

Description

Technical Field

[0001] The present application relates to the technical field of fault diagnosis of silicon single crystal equipment, and in particular to a method for monitoring the wear of a ball screw in a crucible lifting mechanism of a CZ silicon single crystal furnace. Background Art

[0002] Silicon is an important semiconductor material, widely used in integrated circuits and photovoltaic industries. At present, the preparation of silicon single crystals mainly adopts the Czochralski method, and the corresponding equipment is the Czochralski silicon single crystal furnace. In the Czochralski silicon single crystal furnace, the crucible lifting mechanism is one of the important components. Its main function is to achieve the smooth lifting of the crucible during the preparation of silicon single crystals, to ensure the stability of the liquid level of the silicon solution in the crucible and the uniformity of the thermal field, so that the prepared silicon single crystals have higher quality and yield.

[0003] The working principle of the crucible lifting mechanism is: using a double-guide column linear bearing guide structure, a high-precision motor drives the ball screw through a toothed belt and a harmonic reducer to achieve lifting movement. Since the crucible lifting mechanism is in a low-speed and high-load operation state for a long time, the ball screw is prone to wear and deformation after long-term use. The balls in the ball screw will cause the crucible to lift and lower unsteadily due to friction. If the potential fault is not discovered in time, it is likely to cause the ball screw to fail to work properly, causing great safety hazards in the silicon single crystal preparation process. Therefore, real-time monitoring of the wear of the ball screw is a necessary measure to ensure the normal operation of the direct-pull silicon single crystal furnace and the pulling of high-quality silicon single crystals. However, the current monitoring of the wear of the ball screw has the following problems:

[0004] At present, the monitoring of the wear of the ball screw in the crucible lifting mechanism of the CZ silicon single crystal furnace still mainly relies on manual regular inspection. This monitoring method not only consumes human resources, but also has the problem of untimely and inaccurate monitoring of the ball screw. In the field of machine tools, the wear of the ball screw can usually be reflected by the vibration signal; however, the equipment of the CZ silicon single crystal furnace is large and the overall structure is relatively stable, resulting in very weak vibration signals collected, making it difficult to conduct effective vibration analysis, and thus it is difficult to achieve real-time monitoring of the wear of the ball screw.

[0005] Therefore, it is necessary to propose a solution to improve one or more problems existing in the above-mentioned related technical solutions.

[0006] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0007] The present application provides a method for monitoring the wear of a ball screw in a crucible lifting mechanism of a CZ silicon single crystal furnace, the method comprising the following steps:

[0008] A wire encoder is installed on the crucible lifting mechanism, wherein the wire of the wire encoder is connected to the ball screw, and the wire encoder is used to convert the rotational motion of the ball screw into an electrical signal;

[0009] A programmable logic controller is installed on the motor output shaft of the crucible lifting mechanism, wherein the programmable logic controller includes a pulse generator and a pulse counter, wherein the pulse generator converts the electrical signal into a pulse signal, and the pulse counter records the number of pulses according to the pulse signal;

[0010] In an unworn state of the ball screw, a first number of rotations of the motor output shaft is calculated according to the ideal number of pulses recorded by the pulse counter, the ideal number of rotations of the ball screw and the ideal displacement of the crucible lifting mechanism are calculated in sequence using the first number of rotations, and a first relationship curve between the ideal number of rotations and the ideal displacement is drawn on the display and control end;

[0011] Determine a first wear threshold and a second wear threshold at the display and control end respectively according to the first relationship curve;

[0012] Under the actual wear state of the ball screw, a second number of rotations of the motor output shaft is calculated according to the actual number of pulses recorded by the pulse counter, the actual number of rotations of the ball screw and the actual displacement of the crucible lifting mechanism are calculated in sequence using the second number of rotations, and a second relationship curve between the actual number of rotations and the actual displacement is drawn on the display and control end;

[0013] The second relationship curve is compared with the first wear threshold and the second wear threshold respectively, and the comparison result is updated in real time to achieve real-time monitoring of the wear condition of the ball screw.

[0014] In an exemplary embodiment of the present application, the step of installing a wire encoder on the crucible lifting mechanism, wherein the wire of the wire encoder is connected to the ball screw, comprises:

[0015] Determining the type of the draw wire encoder;

[0016] The wire encoder is installed on the crucible lifting mechanism, and the wire encoder includes a wire box and an encoder. The wire box and the encoder are both installed on a fixed base of the crucible lifting mechanism. The wire box is provided with the wire, and the exposed end of the wire is connected to the ball nut on the ball screw.

[0017] A first operating parameter of the wire draw encoder is determined.

[0018] In an exemplary embodiment of the present application, the type of the wire draw encoder is an incremental wire draw encoder; the first operating parameter includes the first resolution, operating voltage, signal output type and protection level of the wire draw encoder.

[0019] In an exemplary embodiment of the present application, the step of installing a programmable logic controller on the motor output shaft of the crucible lifting mechanism includes: setting the second operating parameters of the pulse counter, and the second operating parameters include: the second resolution of the pulse counter, the pulse direction and the initial value.

[0020] In an exemplary embodiment of the present application, the steps of calculating a first number of rotations of the motor output shaft according to the ideal number of pulses recorded by the pulse counter when the ball screw is in an unworn state, calculating the ideal number of rotations of the ball screw and the ideal displacement of the crucible lifting mechanism in sequence using the first number of rotations, and drawing a first relationship curve between the ideal number of rotations and the ideal displacement on the display and control end include:

[0021] In the unworn state, the ideal rotational motion of the ball screw is converted into an ideal electrical signal using the draw wire encoder;

[0022] The ideal electrical signal is converted into an ideal pulse signal by using the pulse generator, and the pulse counter records the ideal pulse number according to the ideal pulse signal;

[0023] Calculating the first number of rotations, the ideal number of rotations and the ideal displacement in sequence using the ideal number of pulses recorded by the pulse generator;

[0024] The programmable logic controller sends the ideal number of rotations and the ideal displacement to the display and control end according to the communication protocol, and the display and control end draws the first relationship curve using a drawing tool.

[0025] In an exemplary embodiment of the present application, the calculation formula for the first number of rotations is:

[0026] (1)

[0027] in, Indicates the first rotation number of the motor output shaft, represents the ideal number of pulses recorded by the pulse counter, Indicates the resolution of the pulse generator;

[0028] The calculation formula for the ideal number of rotations is:

[0029] (2)

[0030] in, Indicates the ideal number of rotations of the ball screw, Indicates the transmission ratio between the motor and the ball screw;

[0031] The calculation formula of the ideal displacement is:

[0032] (3)

[0033] in, represents the ideal displacement of the crucible lifting mechanism, Indicates the lead of the ball screw, represents the ideal pitch of the ball screw, , Indicates the number of screw heads of a ball screw.

[0034] In an exemplary embodiment of the present application, the step of determining the first wear threshold and the second wear threshold respectively at the display and control end according to the first relationship curve includes: it is also necessary to determine the first wear threshold and the second wear threshold respectively according to the performance parameters of the ball screw and the drawing requirements of the silicon single crystal.

[0035] In an exemplary embodiment of the present application, the step of calculating the second number of rotations of the motor output shaft according to the actual number of pulses recorded by the pulse counter under the actual wear state of the ball screw, calculating the actual number of rotations of the ball screw and the actual displacement of the crucible lifting mechanism in sequence using the second number of rotations, and drawing a second relationship curve between the actual number of rotations and the actual displacement on the display and control end includes:

[0036] In the actual wear state, the actual rotational motion of the ball screw is converted into an actual electrical signal using the draw wire encoder;

[0037] The actual electrical signal is converted into an actual pulse signal by using the pulse generator, and the pulse counter records the actual number of pulses according to the actual pulse signal;

[0038] Calculating the second number of rotations, the actual number of rotations and the actual displacement in sequence using the actual number of pulses recorded by the pulse counter;

[0039] The programmable logic controller sends the actual number of rotations and the actual displacement to the display and control end according to the communication protocol, and the display and control end draws the second relationship curve using the drawing tool.

[0040] In an exemplary embodiment of the present application, the calculation formula for the second number of rotations is:

[0041] (4)

[0042] in, Indicates the second rotation number of the motor output shaft, Indicates the actual number of pulses recorded by the pulse counter, Indicates the resolution of the pulse generator;

[0043] The calculation formula of the actual number of rotations is:

[0044] (5)

[0045] in, Indicates the actual number of rotations of the ball screw. Indicates the transmission ratio between the motor and the ball screw;

[0046] The calculation formula of the actual displacement is:

[0047] (6)

[0048] in, represents the actual displacement of the crucible lifting mechanism, Indicates the actual pitch of the ball screw, , Indicates the number of screw heads of a ball screw.

[0049] In an exemplary embodiment of the present application, the step of comparing the second relationship curve with the first wear threshold and the second wear threshold respectively, and updating the comparison result in real time to realize real-time monitoring of the wear condition of the ball screw includes:

[0050] Setting an update period of the second relationship curve at the display and control end, and comparing the second relationship curve after each update with the first wear threshold and the second wear threshold, respectively, to obtain the comparison result updated in real time;

[0051] When the comparison result does not exceed the first wear threshold, it indicates that the ball screw is in a normal state;

[0052] When the comparison result reaches or exceeds the first wear threshold and does not reach the second wear threshold, it indicates that the ball screw needs to be lubricated;

[0053] When the comparison result reaches or exceeds the second wear threshold, it indicates that the ball screw needs to be repaired or replaced;

[0054] The second wear threshold is greater than the first wear threshold.

[0055] Beneficial effects:

[0056] The present application provides a method for monitoring the wear of a ball screw in a crucible lifting mechanism of a CZ silicon single crystal furnace, which has at least the following beneficial effects:

[0057] (1) The present application sets a wire encoder and a programmable logic controller on the crucible lifting mechanism, uses the wire encoder to collect the displacement information of the ball screw, and transmits the displacement information to the display and control end after conversion and reading by the programmable logic controller, and updates it in real time, thereby realizing real-time monitoring of the wear of the ball screw, reducing the cost of manual maintenance and equipment downtime, and ensuring the real-time and accuracy of monitoring the wear of the ball screw;

[0058] (2) This application ignores the running speed of the crucible lifting mechanism by comparing the number of rotations of the lead screw with the corresponding displacement of the crucible lifting mechanism, thereby reducing the influence of some factors on the monitoring results;

[0059] (3) The present application draws and displays the first relationship curve, the second relationship curve, the first wear threshold and the second wear threshold on the same curve chart on the display and control end, so that the operator can realize real-time monitoring of the wear condition of the ball screw based on the real-time updated comparison results. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present application, and together with the specification are used to explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0061] Figure 1 A schematic diagram showing the steps of a method for monitoring the wear of a ball screw in a crucible lifting mechanism of a CZ silicon single crystal furnace in an exemplary embodiment of the present application;

[0062] Figure 2 A schematic flow chart showing a method for monitoring wear of a ball screw in a crucible lifting mechanism of a CZ silicon single crystal furnace in an exemplary embodiment of the present application;

[0063] Figure 3 A curve relationship diagram showing the rotation number of the ball screw and the displacement of the crucible lifting mechanism in an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0064] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0065] In addition, the accompanying drawings are only schematic illustrations of the present application and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and thus their repeated description will be omitted. Some of the block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software form, or implemented in one or more hardware modules or integrated circuits, or implemented in different networks and / or processor devices and / or microcontroller devices.

[0066] To this end, this exemplary embodiment provides a method for monitoring the wear of a ball screw in a crucible lifting mechanism of a CZ silicon single crystal furnace, such as Figure 1 and Figure 2 As shown, the method may include the following steps:

[0067] Step S101: Install a wire encoder on the crucible lifting mechanism, wherein the wire of the wire encoder is connected to the ball screw, and the wire encoder is used to convert the rotational motion of the ball screw into an electrical signal.

[0068] Step S102: a programmable logic controller is installed on the motor output shaft of the crucible lifting mechanism. The programmable logic controller includes a pulse generator and a pulse counter. The pulse generator converts the electrical signal into a pulse signal, and the pulse counter records the number of pulses according to the pulse signal.

[0069] Step S103: When the ball screw is in an unworn state, the first number of rotations of the motor output shaft is calculated according to the ideal number of pulses recorded by the pulse counter, and the ideal number of rotations of the ball screw and the ideal displacement of the crucible lifting mechanism are calculated in sequence using the first number of rotations, and a first relationship curve between the ideal number of rotations and the ideal displacement is drawn on the display and control end.

[0070] Step S104: determining a first wear threshold and a second wear threshold respectively at the display control end according to the first relationship curve.

[0071] Step S105: Under the actual wear state of the ball screw, the second rotation number of the motor output shaft is calculated according to the actual number of pulses recorded by the pulse counter, and the actual rotation number of the ball screw and the actual displacement of the crucible lifting mechanism are calculated in sequence using the second rotation number, and a second relationship curve between the actual rotation number and the actual displacement is drawn on the display and control end.

[0072] Step S106: Compare the second relationship curve with the first wear threshold and the second wear threshold respectively, and update the comparison result in real time to achieve real-time monitoring of the wear condition of the ball screw.

[0073] The present application embodiment provides a method for monitoring the wear of a ball screw in a crucible lifting mechanism of a CZ silicon single crystal furnace, which has at least the following beneficial effects:

[0074] (1) The present application sets a wire encoder and a programmable logic controller on the crucible lifting mechanism, uses the wire encoder to collect the displacement information of the ball screw, and transmits the displacement information to the display and control end after conversion and reading by the programmable logic controller, and updates it in real time, thereby realizing real-time monitoring of the wear of the ball screw, reducing the cost of manual maintenance and equipment downtime, and ensuring the real-time and accuracy of monitoring the wear of the ball screw;

[0075] (2) This application ignores the running speed of the crucible lifting mechanism by comparing the number of rotations of the lead screw with the corresponding displacement of the crucible lifting mechanism, thereby reducing the influence of some factors on the monitoring results;

[0076] (3) The present application draws and displays the first relationship curve, the second relationship curve, the first wear threshold and the second wear threshold on the same curve chart on the display and control end, so that the operator can realize real-time monitoring of the wear condition of the ball screw based on the real-time updated comparison results.

[0077] The crucible lifting mechanism is located at the bottom base of the silicon single crystal furnace. Unlike the machine tool transmission mechanism, the bottom structure of the silicon single crystal furnace is usually very stable, and the vibration signal characteristics of the ball screw due to wear are very weak. It is difficult to directly use the existing wear monitoring technology based on vibration signals to perform real-time monitoring of the wear of the ball screw in the crucible lifting mechanism of the single crystal furnace. In order to solve the above problems, the present application proposes a wear monitoring method for the ball screw in the crucible lifting mechanism of the direct-pull silicon single crystal furnace. The method is described in more detail below.

[0078] In step S101, a wire encoder is installed on the crucible lifting mechanism, the wire of the wire encoder is connected to the ball screw, and the wire encoder is used to convert the rotational motion of the ball screw into an electrical signal. In this embodiment, step S101 includes the following sub-steps:

[0079] Sub-step S1011: Determine the type of the wire encoder.

[0080] Furthermore, the wire draw encoder is preferably an incremental wire draw encoder.

[0081] Sub-step S1012: Install a wire-pull encoder on the crucible lifting mechanism. The wire-pull encoder generally includes a wire-pull box and an encoder that are connected to each other. The wire-pull box and the encoder are installed on a fixed base of the crucible lifting mechanism. A wire-pull is provided in the wire-pull box. The exposed end of the wire-pull in the wire-pull box is connected to the ball nut on the ball screw. The wire-pull is tied to the ball nut, and the wire-pull stretches or contracts as the crucible moves. The spring inside the encoder can ensure that the wire-pull maintains a certain tension when it stretches or contracts. When installing the wire-pull encoder, it is also necessary to adjust the position and direction of the encoder to ensure that the wire-pull pulled out by the wire-pull encoder is parallel to the outlet line to avoid friction between the wire-pull and the outlet.

[0082] Sub-step S1013: Determine the first working parameter of the wire encoder.

[0083] Furthermore, the first operating parameters include a first resolution, an operating voltage, a signal output type and a protection level of the wire encoder.

[0084] In step S102, a programmable logic controller (PLC) is installed on the motor output shaft of the crucible lifting mechanism. The programmable logic controller includes a pulse generator and a pulse counter. The pulse generator converts the electrical signal into a pulse signal, and the pulse counter records the number of pulses according to the pulse signal.

[0085] Furthermore, the number of pulses per rotation of the motor is determined by the rotation characteristics of the motor. Therefore, it is first necessary to use a pulse generator to convert the electrical signal into a pulse signal, and then use a pulse counter to record the number of pulses based on the pulse signal. This requires setting the second working parameter of the pulse counter. The second working parameter includes the second resolution of the pulse counter, the pulse direction and the initial value. In this way, real-time monitoring of the number of rotations of the motor can be achieved by reading the value on the pulse counter. The number of pulses here is cumulative, and the number of pulses collected by the pulse counter can also be converted into the number of rotations of the motor output shaft by calculation. The pulse generator and the pulse counter are communicatively connected.

[0086] In step S103, when the ball screw is not worn, the first number of rotations of the motor output shaft is calculated according to the ideal number of pulses recorded by the pulse counter, and the ideal number of rotations of the ball screw and the ideal displacement of the crucible lifting mechanism are calculated in sequence using the first number of rotations, and a first relationship curve between the ideal number of rotations and the ideal displacement is drawn on the display and control end. Step S103 of this embodiment includes the following sub-steps:

[0087] Sub-step S1031: Under ideal conditions, that is, when the ball screw is not worn, the ideal rotational motion of the ball screw is converted into an ideal electrical signal using a draw wire encoder.

[0088] Sub-step S1032: using a pulse generator to convert the ideal electrical signal into an ideal pulse signal, and using a pulse counter to record the number of ideal pulses according to the ideal pulse signal.

[0089] Sub-step S1033: using the ideal pulse number recorded by the pulse counter, the first number of rotations, the ideal number of rotations and the ideal displacement are calculated in sequence.

[0090] Furthermore, the calculation formula for the first number of rotations is:

[0091] (1)

[0092] in, Indicates the first rotation number of the motor output shaft, represents the ideal number of pulses recorded by the pulse counter, Indicates the resolution of the pulse generator.

[0093] Furthermore, the calculation formula for the ideal number of rotations is:

[0094] (2)

[0095] in, Indicates the ideal number of rotations of the ball screw, Indicates the transmission ratio between the motor and the ball screw.

[0096] Furthermore, the calculation formula of the ideal displacement is:

[0097] (3)

[0098] in, represents the ideal displacement of the crucible lifting mechanism, Indicates the lead of the ball screw, represents the ideal pitch of the ball screw, , Indicates the number of screw heads of a ball screw.

[0099] Sub-step S1034: the programmable logic controller sends the ideal number of rotations and the ideal displacement to the display and control end according to the communication protocol, and the display and control end draws a first relationship curve using a drawing tool.

[0100] In step S104, a first wear threshold and a second wear threshold are respectively determined on the display control end according to the first relationship curve.

[0101] Furthermore, based on the first relationship curve, the first wear threshold and the second wear threshold need to be determined respectively according to the performance parameters of the ball screw and the drawing requirements of the silicon single crystal.

[0102] In step S105, under the actual wear state of the ball screw, the second number of rotations of the motor output shaft is calculated according to the actual number of pulses recorded by the pulse counter, and the actual number of rotations of the ball screw and the actual displacement of the crucible lifting mechanism are calculated in sequence using the second number of rotations, and a second relationship curve between the actual number of rotations and the actual displacement is drawn on the display and control end. Step S105 of this embodiment includes the following sub-steps:

[0103] Sub-step S1051: Under the actual wear state of the ball screw, the actual rotational motion of the ball screw is converted into an actual electrical signal using a wire encoder.

[0104] Sub-step S1052: using a pulse generator to convert the actual electrical signal into an actual pulse signal, and the pulse counter records the actual number of pulses according to the actual pulse signal.

[0105] Sub-step S1053: using the actual number of pulses recorded by the pulse counter, the second number of rotations, the actual number of rotations and the actual displacement are calculated in sequence.

[0106] Furthermore, the calculation formula for the second number of rotations is:

[0107] (4)

[0108] in, Indicates the second rotation number of the motor output shaft, Indicates the actual number of pulses recorded by the pulse counter, Indicates the resolution of the pulse generator.

[0109] Furthermore, the calculation formula for the actual number of rotations is:

[0110] (5)

[0111] in, Indicates the actual number of rotations of the ball screw. Indicates the transmission ratio between the motor and the ball screw.

[0112] Furthermore, the calculation formula of the actual displacement is:

[0113] (6)

[0114] in, represents the actual displacement of the crucible lifting mechanism, Indicates the actual pitch of the ball screw, , Indicates the number of screw heads of a ball screw.

[0115] Sub-step S1054: the programmable logic controller sends the actual number of rotations and the actual displacement to the display and control end according to the communication protocol, and the display and control end draws a second relationship curve using a drawing tool.

[0116] Furthermore, the display and control terminal may be a human-machine interface or a data acquisition system, wherein professional drawing tools such as a chart library or a drawing module may be selected.

[0117] like Figure 3 As shown, in step S106, the second relationship curve is compared with the first wear threshold and the second wear threshold respectively, and the comparison result is updated in real time to achieve real-time monitoring of the wear condition of the ball screw. In this embodiment, S106 includes the following sub-steps:

[0118] Sub-step S1061: setting an update period of the second relationship curve on the display control end, and comparing the second relationship curve after each update with the first wear threshold and the second wear threshold, so as to obtain a comparison result updated in real time.

[0119] Sub-step S1062: When the comparison result does not exceed the first wear threshold, it indicates that the ball screw is in a normal state.

[0120] Sub-step S1063: When the comparison result reaches or exceeds the first wear threshold and does not reach the second wear threshold, it indicates that the ball screw needs to be lubricated, and lubricant can be added to lubricate the ball screw.

[0121] Sub-step S1064: When the comparison result reaches or exceeds the second wear threshold, it indicates that the ball screw needs to be repaired or replaced.

[0122] Here, the second wear threshold is greater than the first wear threshold.

[0123] After steps S103 to S106, the first relationship curve, the first wear threshold, the second wear threshold and the second relationship curve are drawn on the same graph, and the comparison result is updated in real time, so that the operator can clearly and intuitively monitor the wear condition of the ball screw in real time.

[0124] It should also be noted that: Figure 2 and Figure 3 Threshold 1 in refers to the first wear threshold, and threshold 2 refers to the second wear threshold. Figure 3 The "unworn" refers to the unworn state of the ball screw. Figure 3 The actual refers to the actual wear state of the ball screw.

[0125] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0126] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0127] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present application, and these modifications or substitutions should be included in the protection scope of the present application.

[0128] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary technical means in the art that are not disclosed in the present application.

Claims

1. A method for monitoring the wear of a ball screw in a crucible lifting mechanism of a CZ silicon single crystal furnace, characterized in that: The method comprises the following steps: A wire encoder is installed on the crucible lifting mechanism, wherein the wire of the wire encoder is connected to the ball screw, and the wire encoder is used to convert the rotational motion of the ball screw into an electrical signal; A programmable logic controller is installed on the motor output shaft of the crucible lifting mechanism, wherein the programmable logic controller includes a pulse generator and a pulse counter, wherein the pulse generator converts the electrical signal into a pulse signal, and the pulse counter records the number of pulses according to the pulse signal; In an unworn state of the ball screw, a first number of rotations of the motor output shaft is calculated according to the ideal number of pulses recorded by the pulse counter, the ideal number of rotations of the ball screw and the ideal displacement of the crucible lifting mechanism are calculated in sequence using the first number of rotations, and a first relationship curve between the ideal number of rotations and the ideal displacement is drawn on the display and control end; The calculation formula of the first number of rotations is: Where p1 represents the first rotation number of the motor output shaft, m1 represents the ideal number of pulses recorded by the pulse counter, and f represents the resolution of the pulse generator; The calculation formula of the ideal number of rotations is: n 理想 =p1×k (2) Among them, n 理想 represents the ideal number of rotations of the ball screw, and k represents the transmission ratio between the motor and the ball screw; The calculation formula of the ideal displacement is: s1=l=d1×u (3) Where s1 represents the ideal displacement of the crucible lifting mechanism, l represents the lead of the ball screw, d1 represents the ideal pitch of the ball screw, and d1 = n 理想 , u represents the number of screw heads of the ball screw; Determine a first wear threshold and a second wear threshold at the display and control end respectively according to the first relationship curve; Under the actual wear state of the ball screw, a second number of rotations of the motor output shaft is calculated according to the actual number of pulses recorded by the pulse counter, the actual number of rotations of the ball screw and the actual displacement of the crucible lifting mechanism are calculated in sequence using the second number of rotations, and a second relationship curve between the actual number of rotations and the actual displacement is drawn on the display and control end; The calculation formula of the second number of rotations is: Wherein, p2 represents the second rotation number of the motor output shaft, m2 represents the actual number of pulses recorded by the pulse counter, and f represents the resolution of the pulse generator; The calculation formula of the actual number of rotations is: n 实际 =p2×k (5) Among them, n 实际 represents the actual number of rotations of the ball screw, and k represents the transmission ratio between the motor and the ball screw; The calculation formula of the actual displacement is: s2=d2×u (6) Among them, s2 represents the actual displacement of the crucible lifting mechanism, d2 represents the actual pitch of the ball screw, and d2 = n 实际 , u represents the number of screw heads of the ball screw; The second relationship curve is compared with the first wear threshold and the second wear threshold respectively, and the comparison result is updated in real time to achieve real-time monitoring of the wear condition of the ball screw.

2. The wear monitoring method of the ball screw in the crucible lifting mechanism of the CZ silicon single crystal furnace according to claim 1 is characterized in that: The step of installing a wire encoder on the crucible lifting mechanism, wherein the wire of the wire encoder is connected to the ball screw, comprises: Determining the type of the draw wire encoder; The wire encoder is installed on the crucible lifting mechanism, and the wire encoder includes a wire box and an encoder. The wire box and the encoder are both installed on a fixed base of the crucible lifting mechanism. The wire box is provided with the wire, and the exposed end of the wire is connected to the ball nut on the ball screw. A first operating parameter of the wire draw encoder is determined.

3. The wear monitoring method of the ball screw in the crucible lifting mechanism of the CZ silicon single crystal furnace according to claim 2 is characterized in that: The type of the wire draw encoder is an incremental wire draw encoder; the first operating parameters include the first resolution, operating voltage, signal output type and protection level of the wire draw encoder.

4. The wear monitoring method of the ball screw in the crucible lifting mechanism of the CZ silicon single crystal furnace according to claim 3 is characterized in that: The step of installing a programmable logic controller on the motor output shaft of the crucible lifting mechanism includes: setting the second working parameters of the pulse counter, and the second working parameters include: the second resolution of the pulse counter, the pulse direction and the initial value.

5. The wear monitoring method of the ball screw in the crucible lifting mechanism of the CZ silicon single crystal furnace according to claim 4 is characterized in that: The step of calculating a first number of rotations of the motor output shaft according to the ideal number of pulses recorded by the pulse counter when the ball screw is in an unworn state, calculating the ideal number of rotations of the ball screw and the ideal displacement of the crucible lifting mechanism in sequence using the first number of rotations, and drawing a first relationship curve between the ideal number of rotations and the ideal displacement on the display and control end comprises: In the unworn state, the ideal rotational motion of the ball screw is converted into an ideal electrical signal using the draw wire encoder; The ideal electrical signal is converted into an ideal pulse signal by using the pulse generator, and the pulse counter records the ideal pulse number according to the ideal pulse signal; Calculating the first number of rotations, the ideal number of rotations and the ideal displacement in sequence using the ideal number of pulses recorded by the pulse counter; The programmable logic controller sends the ideal number of rotations and the ideal displacement to the display and control end according to the communication protocol, and the display and control end draws the first relationship curve using a drawing tool.

6. The wear monitoring method of the ball screw in the crucible lifting mechanism of the CZ silicon single crystal furnace according to claim 5, characterized in that: The step of determining the first wear threshold and the second wear threshold at the display and control end respectively according to the first relationship curve includes: the first wear threshold and the second wear threshold need to be determined respectively according to the performance parameters of the ball screw and the drawing requirements of the silicon single crystal.

7. The wear monitoring method of the ball screw in the crucible lifting mechanism of the CZ silicon single crystal furnace according to claim 6, characterized in that: The step of calculating the second number of rotations of the motor output shaft according to the actual number of pulses recorded by the pulse counter under the actual wear state of the ball screw, calculating the actual number of rotations of the ball screw and the actual displacement of the crucible lifting mechanism in sequence by using the second number of rotations, and drawing a second relationship curve between the actual number of rotations and the actual displacement on the display and control end comprises: In the actual wear state, the actual rotational motion of the ball screw is converted into an actual electrical signal using the draw wire encoder; The actual electrical signal is converted into an actual pulse signal by using the pulse generator, and the pulse counter records the actual number of pulses according to the actual pulse signal; Calculating the second number of rotations, the actual number of rotations and the actual displacement in sequence using the actual number of pulses recorded by the pulse counter; The programmable logic controller sends the actual number of rotations and the actual displacement to the display and control end according to the communication protocol, and the display and control end draws the second relationship curve using the drawing tool.

8. The wear monitoring method of the ball screw in the crucible lifting mechanism of the CZ silicon single crystal furnace according to claim 7, characterized in that: The step of comparing the second relationship curve with the first wear threshold and the second wear threshold respectively, and updating the comparison result in real time to realize real-time monitoring of the wear condition of the ball screw comprises: Setting an update period of the second relationship curve at the display and control end, and comparing the second relationship curve after each update with the first wear threshold and the second wear threshold, respectively, to obtain the comparison result updated in real time; When the comparison result does not exceed the first wear threshold, it indicates that the ball screw is in a normal state; When the comparison result reaches or exceeds the first wear threshold and does not reach the second wear threshold, it indicates that the ball screw needs to be lubricated; When the comparison result reaches or exceeds the second wear threshold, it indicates that the ball screw needs to be repaired or replaced; The second wear threshold is greater than the first wear threshold.

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