Selective welding equipment liquid level height detection device and method

Abstract

The invention relates to the technical field of soldering tin liquid level detection, in particular to a liquid level height detection device and method for selective welding equipment, and the device comprises a tin furnace which comprises a furnace body and a furnace cover, and the furnace cover is provided with a sinking observation pipe which penetrates through the exterior of the furnace body to the interior of the furnace body; the driving control assembly is used for driving the tin furnace to rotate in the X-axis direction, the Y-axis direction and the Z-axis direction; the laser sensor is used for detecting the height of the tin liquid in the tin furnace through the sinking observation pipe; the control module comprises a receiving unit used for receiving the liquid level detection instruction and receiving a detection value from the laser sensor; the control unit is used for responding to the liquid level detection instruction, driving the tin furnace to a preset coordinate and controlling the laser sensor to carry out detection; the judging unit is used for judging whether the detection value falls into a preset interval or not; and the alarm unit is used for sending alarm information if the detection value does not fall into the preset interval. The method has the effect of improving the detection accuracy and the equipment compatibility.

Description

Technical Field

[0001] The invention relates to the technical field of solder liquid level detection, and in particular to a liquid level height detection device and method for selective soldering equipment. Background Art

[0002] In the field of high-end soldering manufacturing of PCB boards, selective wave soldering technology is widely used due to its high efficiency and precise soldering effect. However, in the selective wave soldering process, the liquid level in the tin furnace is a crucial process parameter, which directly affects the height of the soldering wave and the soldering quality.

[0003] When the liquid level is too low, if the peak height is not corrected, the welding peak will decrease, resulting in poor welding and affecting the reliability and stability of the product. If the peak height is corrected, when the liquid level is low, the inverter needs to increase the power to maintain the consistency of the liquid level. However, when the liquid level is extremely low, the inverter may not be able to restore the liquid level even at its maximum power, which may not only damage the inverter, but also reduce product quality due to poor welding. Therefore, when the liquid level is too low, manual or automatic tinning devices are usually required to replenish solder to ensure the smooth progress of the welding process.

[0004] On the other hand, when the liquid level is too high, the inverter power also needs to be adjusted to maintain the consistency of the liquid level. However, too high a liquid level will increase the risk of tin overflow and pose a threat to safe production. Therefore, accurate detection and monitoring of the tin furnace liquid level height is particularly important in selective wave soldering.

[0005] At present, there are two main ways to detect the liquid level of tin furnaces on the market: one is the float method, which has high accuracy, but the cost is relatively high and the installation process is complicated. In addition, different types of wave soldering machines need to be equipped with different types of floats, which increases the compatibility and maintenance cost of the equipment. The other is the probe method, which uses one or more probes to determine whether the liquid level has reached a preset position, but the accuracy is low and the accuracy is poor, which is difficult to meet the strict requirements of high-end application fields for welding quality. Summary of the invention

[0006] In order to improve detection accuracy and equipment compatibility, the present application provides a liquid level detection device and method for selective welding equipment.

[0007] The above-mentioned invention objective of the present application is achieved through the following technical solutions:

[0008] A liquid level detection device for selective welding equipment, comprising:

[0009] A tin furnace, comprising a furnace body and a furnace cover, wherein the furnace cover is provided with a sinking observation pipe penetrating from the outside of the furnace body to the inside of the furnace body;

[0010] The drive control component is used to drive the tin furnace to rotate in the three-axis directions of X, Y and Z;

[0011] A laser sensor, wherein the laser sensor detects the height of the molten tin in the tin furnace through a sinking observation tube;

[0012] A control module, the control module comprising:

[0013] A receiving unit, used for receiving a liquid level detection instruction and for receiving a detection value from a laser sensor;

[0014] A control unit, for driving the tin furnace to a preset coordinate in response to a liquid level detection instruction, and controlling the laser sensor to perform detection, wherein the preset coordinate corresponds to a physical position where the tin furnace is located at which the laser sensor can detect the height of the tin liquid in the tin furnace through the sinking observation tube;

[0015] A judging unit, used to judge whether the detection value falls within a preset interval;

[0016] The alarm unit is used to issue an alarm message if the detection value does not fall within a preset interval.

[0017] In a preferred example, the present application may be further configured as follows: the receiving module is also used to receive a life detection instruction;

[0018] The control module also includes:

[0019] Tin liquid temperature monitoring unit, used to monitor the temperature of tin liquid in the tin furnace;

[0020] The recording unit is used to record the temperature of the tin liquid to form historical detection data when receiving a liquid level detection instruction; the historical detection data is reset after the laser sensor is replaced.

[0021] In a preferred example, the present application can be further configured as follows: the control module further includes:

[0022] A scrap value calculation unit, used to calculate the scrap value according to the historical detection data, the tin liquid temperature curve and the normal working temperature range of the laser sensor, wherein the tin liquid temperature curve is a function relationship of temperature with respect to time;

[0023] If the scrap value reaches a preset value, the alarm unit issues a replacement prompt message.

[0024] In a preferred example, the present application can be further configured as follows: the control module further includes:

[0025] Scrap value calculation unit, including:

[0026] A calculation subunit, used to calculate a first proportional factor m% of the time length of the tin liquid temperature curve within the normal working temperature range to the total time length, and a second proportional factor n% of the time length of the tin liquid temperature curve outside the normal working temperature range to the total time length;

[0027] The set generation subunit is used to generate a first tin liquid temperature set in the historical detection data that is within the normal operating temperature range, and a second tin liquid temperature set in the historical detection data that is outside the normal operating temperature range; remove the first tin liquid temperature set in the range of [t, t max ]; remove the elements between [t max , 2t max -t]; the number of elements in the first tin liquid temperature set after removing the elements is p, and the number of elements in the second tin liquid temperature set after removing the elements is q;

[0028] The calculation subunit is used to calculate the scrap value k according to the following formula:

[0029]

[0030] Among them, α is the normal influence coefficient, which represents the influence of each detection within the normal working temperature range on the scrap degree; β is the over-temperature influence coefficient, which represents the basic influence of each detection beyond the normal working temperature range on the scrap degree; k is the slope parameter, which controls the sensitivity of temperature influence; t i is the solder paste temperature at each test that exceeds the normal operating temperature range; t is the preset reference temperature, and the normal temperature range is [t min , t max ].

[0031] In a preferred example, the present application can be further configured as follows: wherein α=0.00006, β=0.0085, and r=6.3.

[0032] In a preferred example, the present application may be further configured as follows: the control module further includes a counting unit for counting the number of detection instructions;

[0033] When the number of detection instructions reaches a preset number, the scrap value calculation unit calculates a scrap value.

[0034] The second object of the invention is achieved by the following technical solutions:

[0035] A detection method based on any of the aforementioned selective welding equipment liquid level detection devices, comprising:

[0036] Receive liquid level detection instructions and receive detection values ​​from laser sensors;

[0037] Driving the tin furnace to a preset coordinate, and controlling the laser sensor to perform detection;

[0038] Determining whether the detection value falls within a preset interval;

[0039] If the detected value does not fall within the preset interval, an alarm message is issued.

[0040] In a preferred example, the present application can be further configured as follows:

[0041] Calculating the scrap value according to the historical detection data, the tin liquid temperature curve and the normal working temperature range of the laser sensor, wherein the tin liquid temperature curve is a function relationship of temperature with respect to time;

[0042] If the scrap value reaches a preset value, a replacement prompt message is issued.

[0043] In a preferred example, the present application can be further configured to calculate the scrap value according to the historical detection data, the tin liquid temperature curve and the normal operating temperature range of the laser sensor, including:

[0044] Calculate a first proportional factor m% of the time length of the tin liquid temperature curve within the normal operating temperature range to the total time length, and a second proportional factor n% of the time length of the tin liquid temperature curve outside the normal operating temperature range to the total time length;

[0045] Generate a first tin liquid temperature set in the historical detection data that is within the normal operating temperature range, and a second tin liquid temperature set in the historical detection data that is outside the normal operating temperature range; remove the first tin liquid temperature set in the range of [t, t max ]; remove the elements between [t max , 2t max -t]; the number of elements in the first tin liquid temperature set after removing the elements is p, and the number of elements in the second tin liquid temperature set after removing the elements is q;

[0046] The scrap value k is calculated according to the following formula:

[0047]

[0048] Among them, α is the normal influence coefficient, which represents the influence of each detection within the normal working temperature range on the scrap degree; β is the over-temperature influence coefficient, which represents the basic influence of each detection beyond the normal working temperature range on the scrap degree; k is the slope parameter, which controls the sensitivity of temperature influence; t i is the solder paste temperature at each test that exceeds the normal operating temperature range; t is the preset reference temperature, and the normal temperature range is [t min , tmax ].

[0049] In summary, the present application includes at least one of the following beneficial technical effects:

[0050] 4. When the liquid level needs to be detected, use the control unit to move the tin furnace to the P1 position, record the value of the digital laser sensor, and compare it with the standard upper and lower limits. When it exceeds the range, an alarm will be issued to improve detection accuracy and equipment compatibility.

[0051] 2. It can predict the life of the laser sensor, remind you to scrap and replace it in advance, and remove and adjust the elements in the set according to the proportion of each temperature range, so that the calculation results are more in line with the actual temperature conditions and the results are more accurate.

[0052] 3. When the temperature is outside the normal operating range, timely prediction and calculation can be performed to remind replacement in advance. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a structural schematic diagram of a liquid level detection device for selective welding equipment in one embodiment of the present application;

[0054] Figure 2 It is a partial structural schematic diagram of a liquid level detection device for selective welding equipment in one embodiment of the present application;

[0055] Figure 3 It is a schematic diagram of the connection of various module units of the liquid level detection device for selective welding equipment in one embodiment of the present application;

[0056] Figure 4 is a schematic diagram of a wave soldering temperature curve in an embodiment of the present application;

[0057] Figure 5 It is a flow chart for implementing the detection method in one embodiment of the present application.

[0058] Figure numerals: 1. tin furnace; 2. laser sensor; 3. furnace body; 4. furnace cover; 5. sinking observation tube. DETAILED DESCRIPTION

[0059] The following is a description of exemplary embodiments of the present application in conjunction with the accompanying drawings, including various details of the embodiments of the present application to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0060] It should be noted that the terms "first", "second", etc. in the present invention are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure.

[0061] In addition, the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article, unless otherwise specified, generally means that the associated objects before and after are in an "or" relationship.

[0062] The liquid level detection device for selective welding equipment of the present application will be described below with reference to the accompanying drawings.

[0063] Reference Figure 1 and Figure 2 The liquid level height detection device of the selective welding equipment includes a tin furnace 1, a drive control component, a laser sensor 2 and a control module. The tin furnace 1 is used to hold solder and melt the solid tin in the furnace cavity through a heating device. The tin furnace 1 includes a furnace body 3 and a furnace cover 4. The furnace cover 4 is provided with a hollow cylindrical sinking observation tube 5. The sinking observation tube 5 is passed through at both ends. The sinking observation tube 5 passes through the outside of the furnace body 3 to the inside of the furnace body 3. The laser sensor 2 can detect the height of the tin liquid in the tin furnace 1 through the sinking observation tube 5.

[0064] The drive control component is used to drive the tin furnace 1 to rotate in the three-axis directions of X, Y, and Z. Commonly used, the drive control component is a three-axis servo motor module to realize the rotation drive of the tin furnace 1 in the three-axis directions of X, Y, and Z, and record and generate the three-axis coordinates in real time.

[0065] The control module includes: a receiving unit, a control unit, a judgment unit and an alarm unit, wherein the receiving unit is used to receive a liquid level detection instruction and to receive a detection value from the laser sensor 2; the liquid level detection instruction is initiated by a staff member, or is detected regularly through a pre-set program.

[0066] The control unit is used to drive the tin pot 1 to a preset coordinate in response to a liquid level detection instruction. The preset coordinate corresponds to a physical position where the tin pot 1 is located at which the laser sensor 2 can detect the height of the tin liquid in the tin pot 1 through the sinking observation tube 5.

[0067] The preset coordinates and preset intervals are determined in the following manner: the digital laser sensor 2 is installed and fixed, and the control unit moves the top surface of the furnace cover 4 of the tin furnace 1 without holes to just below the laser sensor 2. At this time, the coordinate values ​​of XYZ (marked as P0) are recorded, and the value of the laser sensor 2 is recorded at the same time. Based on the value and the normal height range of the tin liquid, the staff sets the standard upper and lower limits to obtain the preset interval. The control unit moves the position of the sinking observation tube 5 of the tin furnace 1 to just below the laser sensor 2, and keeps the Z-axis coordinate value consistent with the Z-axis coordinate value of P0 (the Z-axis coordinate value is consistent with the top surface at P0), and the XYZ coordinate value recorded at this time (marked as P1) is the preset coordinate.

[0068] Reference Figure 3 The judgment unit is used to judge whether the detection value falls within a preset interval, and the alarm unit is used to issue an alarm message if the detection value does not fall within the preset interval.

[0069] In one embodiment, the receiving module is also used to receive a life detection instruction; the control module also includes: a tin liquid temperature monitoring unit and a recording unit, the tin liquid temperature monitoring unit is used to monitor the tin liquid temperature in the tin furnace; the recording unit is used to record the tin liquid temperature to form historical detection data when receiving a liquid level detection instruction; the historical detection data is reset after the laser sensor is replaced, thereby forming historical detection data for the entire life cycle of a single laser sensor, and after replacement, the historical detection data of the previous laser sensor is stored and reset, and the detection data of the new laser sensor is re-recorded.

[0070] Since laser sensors are affected by temperature during work, their lifespan is greatly affected, and their detection accuracy is also greatly affected. The normal temperature range of laser sensors is -45°C to 75°C, while the solder paste temperature varies from 5°C to several hundred degrees Celsius. The solder paste temperature environment is often higher, higher than the normal temperature range. Therefore, in the solution of using laser sensors to detect the solder paste temperature in the tin furnace, the number of historical detections of the laser sensor and the solder paste temperature during each detection will be recorded. Some of these temperatures are within the normal temperature range for detection, which has little impact on the lifespan; some are beyond the normal temperature range for detection, which has a greater impact on the lifespan, and the higher the temperature, the greater the impact. This facilitates the subsequent analysis of the approximate lifespan of the laser sensor so that it can be replaced in time to reduce false detections and failures.

[0071] The control module also includes a scrap value calculation unit, which is used to calculate the scrap value based on historical detection data, the tin liquid temperature curve and the normal operating temperature range of the laser sensor. The tin liquid temperature curve is a function of temperature over time. If the scrap value reaches a preset value, the alarm unit will issue a replacement prompt message.

[0072] It is understandable that during the test, the sinking observation tube is directly facing the laser sensor, and the temperature is high during the test, which has a great impact on the life of the laser sensor, and the detection accuracy deviation is getting bigger and bigger, so it needs to be replaced frequently, and even false alarms may occur due to failure to replace it in time. Therefore, it is necessary to predict the life of the laser sensor so that it can be replaced in time to avoid safety accidents.

[0073] Among them, the scrap value calculation unit includes: a calculation subunit, a set generation subunit and a calculation subunit, and the calculation subunit is used to calculate the first proportional factor m% of the time in the tin liquid temperature curve that is within the normal working temperature range to the total time, and the second proportional factor n% of the time in the tin liquid temperature curve that is outside the normal working temperature range to the total time.

[0074] Combination Figure 4 Specifically, since the present application is applicable to wave soldering, the tin liquid temperature curve usually includes a preheating part, a thermal compensation temperature adjustment part, a wave soldering part, a wave peak temperature adjustment part, and a cooling part, some of which are the normal operating temperature range of the laser sensor, while other intervals are not. Through this step, the respective proportions of the time within the normal operating temperature range and the time outside the normal operating temperature range in the tin liquid temperature curve are obtained.

[0075] The set generation subunit is used to generate a first tin liquid temperature set in the historical detection data that is within the normal operating temperature range, and a second tin liquid temperature set in the historical detection data that is outside the normal operating temperature range; remove the first tin liquid temperature set in the range of [t, t max ]; remove the elements between [t max , 2t max -t]; the number of elements in the first tin liquid temperature set after removing the element is p, and the number of elements in the second tin liquid temperature set after removing the element is q; the normal temperature range of the laser sensor is [t min , t max ]. Generally speaking, t max At 75℃, t min =-45℃, t is the preset reference temperature, the reference temperature t is 64℃, for example, m is 26%, n is 74%, then remove 74% of the elements between [64℃, 75℃] in the first tin liquid temperature set, and remove 26% of the elements between [75℃, 86℃] in the first tin liquid temperature set. Specifically, remove from [64℃, 75℃] from large to small, and remove from [75℃, 86℃] from small to large. If there is a situation where the division is not exact, round up and retain a certain element.

[0076] It can be understood that the influence of temperature deviation in the process from the drive control component driving the tin furnace to the laser sensor detection is removed by calculating the respective proportions of the time within the normal operating temperature range and the time outside the normal operating temperature range in the aforementioned tin liquid temperature curve. For example, it usually takes several seconds for the drive control component to drive the tin furnace to the laser sensor detection. The tin liquid temperature may be within the normal operating temperature range when the liquid level detection instruction is received, but it is outside the normal operating temperature range when the laser sensor is detected, or the tin liquid temperature may be outside the normal operating temperature range when the liquid level detection instruction is received, but it is within the normal operating temperature range when the laser sensor is detected. This factor causes errors in some data, so the elements in the set are removed and adjusted by the proportion of each temperature range, so that the calculation results are more in line with the actual temperature conditions and the results are more accurate.

[0077] The calculation subunit is used to calculate the scrap value k according to the following formula:

[0078]

[0079] Among them, α is the normal influence coefficient, which represents the influence of each normal working temperature range detection on the scrap degree; β is the over-temperature influence coefficient, which represents the basic influence of each detection beyond the normal working temperature range on the scrap degree; r is the slope parameter, which controls the sensitivity of temperature influence; t i is the solder paste temperature at each detection that exceeds the normal operating temperature range. The situation of extremely low temperature, such as minus degrees Celsius, is not considered here, because the temperature during solder paste processing is generally not lower than 0 degrees Celsius. The algorithm consists of two parts, which correspond to the calculation of the interval within the normal temperature range and the interval beyond the normal temperature range.

[0080] The normal influence coefficient α can be obtained by counting the number of times the laser sensor of this model is actually used and scrapped within the normal operating temperature range.

[0081] Based on the formula constructed above, the over-temperature influence coefficient β and the slope parameter r are trained through multiple groups of historical detection data samples. Each group of historical detection data samples is generated from the historical detection data of the laser sensor used to detect the liquid level height of the wave soldering equipment to the scrapping. Then fit or train through the machine learning model. The normal influence coefficient α can also be fitted or trained based on the aforementioned samples through the machine learning model. In one embodiment, α = 0.0000076, β = 0.0085, r = 6.3.

[0082] In one embodiment, the control module further includes a counting unit for counting the number of detection instructions.

[0083] When the number of detection instructions reaches a preset number, the scrap value calculation unit calculates the scrap value. The preset number can be set to 80% of the lowest number of elements in the second tin liquid temperature set when the laser sensor is scrapped according to historical detection data, so as to avoid the situation where all detections are performed outside the normal operating temperature range. When such a situation occurs, the prediction calculation can still be carried out in time to remind replacement in advance.

[0084] The present application also provides a detection method, based on the above selective welding equipment liquid level height detection device, referring to Figure 5 ,include:

[0085] S1, receiving a liquid level detection instruction, and used to receive a detection value from a laser sensor.

[0086] S2. Drive the tin furnace to a preset coordinate. The preset coordinate corresponds to a physical position where the tin furnace is located at a position where the laser sensor can detect the height of the tin liquid in the tin furnace through a sinking observation tube.

[0087] S3. Determine whether the detected value falls within a preset range.

[0088] S4. If the detected value does not fall within the preset range, an alarm message is issued.

[0089] In one embodiment, the detection method further comprises:

[0090] S5. Calculate the scrap value based on historical test data, the tin liquid temperature curve and the normal operating temperature range of the laser sensor. The tin liquid temperature curve is a function of temperature over time.

[0091] S6. If the scrap value reaches a preset value, a replacement prompt message is issued.

[0092] In one embodiment, S5 includes:

[0093] S51, calculating a first proportional factor m% of the time that the tin liquid temperature curve is within the normal operating temperature range to the total time, and a second proportional factor n% of the time that the tin liquid temperature curve is outside the normal operating temperature range to the total time.

[0094] S52, generating a first tin liquid temperature set in the historical detection data that is within the normal operating temperature range, and a second tin liquid temperature set in the historical detection data that is outside the normal operating temperature range; removing the first tin liquid temperature set in the range of [t, t max ]; remove the elements between [t max , 2t max -t]; the number of elements in the first tin liquid temperature set after removing the elements is statistically obtained to be p, and the number of elements in the second tin liquid temperature set after removing the elements is q.

[0095] S53, calculate the scrap value k according to the following formula:

[0096]

[0097] Among them, α is the normal influence coefficient, which represents the influence of each detection within the normal working temperature range on the scrap degree; β is the over-temperature influence coefficient, which represents the basic influence of each detection beyond the normal working temperature range on the scrap degree; k is the slope parameter, which controls the sensitivity of temperature influence; t i is the solder paste temperature at each test that exceeds the normal operating temperature range; t is the preset reference temperature, and the normal temperature range is [t min , t max ].

[0098] The specific definition of the detection method can be found in the above definition of the liquid level detection device for selective welding equipment, which will not be repeated here. Each step of the above detection method can be implemented in whole or in part by software, hardware or a combination thereof.

[0099] Various implementations of the systems and techniques described herein can be realized in digital electronic circuit systems, integrated circuit systems, dedicated ASICs (application specific integrated circuits), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0100] These computer programs (also referred to as programs, software, software applications, or code) include machine instructions for programmable processors and can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. As used herein, the terms "machine-readable medium" and "computer-readable medium" refer to any computer program product, device, and / or means (e.g., disk, optical disk, memory, programmable logic device (PLD)) for providing machine instructions and / or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal for providing machine instructions and / or data to a programmable processor.

[0101] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0102] The systems and techniques described herein may be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0103] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution disclosed in this application can be achieved, and this document is not limited here.

[0104] The above specific implementations do not constitute a limitation on the protection scope of this application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this application should be included in the protection scope of this application.

Claims

1. A liquid level detection device for selective welding equipment, characterized in that: include: A tin furnace, comprising a furnace body and a furnace cover, wherein the furnace cover is provided with a sinking observation pipe penetrating from the outside of the furnace body to the inside of the furnace body; The drive control component is used to drive the tin furnace to rotate in the three-axis directions of X, Y and Z; A laser sensor, wherein the laser sensor detects the height of the molten tin in the tin furnace through a sinking observation tube; A control module, the control module comprising: A receiving unit, used for receiving a liquid level detection instruction and for receiving a detection value from a laser sensor; A control unit, for driving the tin furnace to a preset coordinate in response to a liquid level detection instruction, and controlling the laser sensor to perform detection, wherein the preset coordinate corresponds to the physical position where the tin furnace is located at which the laser sensor can detect the height of the tin liquid in the tin furnace through the sinking observation tube; A judging unit, used to judge whether the detection value falls within a preset interval; The alarm unit is used to issue an alarm message if the detection value does not fall within a preset interval.

2. The liquid level detection device for selective welding equipment according to claim 1, characterized in that: The receiving module is also used to receive a life detection instruction; The control module also includes: Tin liquid temperature monitoring unit, used to monitor the temperature of tin liquid in the tin furnace; The recording unit is used to record the temperature of the tin liquid to form historical detection data when receiving a liquid level detection instruction; the historical detection data is reset after the laser sensor is replaced.

3. The liquid level detection device for selective welding equipment according to claim 2, characterized in that: The control module also includes: A scrap value calculation unit, used to calculate the scrap value according to the historical detection data, the tin liquid temperature curve and the normal working temperature range of the laser sensor, wherein the tin liquid temperature curve is a function relationship of temperature with respect to time; If the scrap value reaches a preset value, the alarm unit issues a replacement prompt message.

4. The liquid level detection device for selective welding equipment according to claim 3, characterized in that: The control module also includes: Scrap value calculation unit, including: A calculation subunit, used to calculate a first proportional factor m% of the time length of the tin liquid temperature curve within the normal working temperature range to the total time length, and a second proportional factor n% of the time length of the tin liquid temperature curve outside the normal working temperature range to the total time length; The set generation subunit is used to generate a first tin liquid temperature set in the historical detection data that is within the normal operating temperature range, and a second tin liquid temperature set in the historical detection data that is outside the normal operating temperature range; remove the first tin liquid temperature set in the range of [t, t max ]; remove the elements between [t max , 2t max -t]; the number of elements in the first tin liquid temperature set after removing the elements is p, and the number of elements in the second tin liquid temperature set after removing the elements is q; The calculation subunit is used to calculate the scrap value k according to the following formula: Among them, α is the normal influence coefficient, which represents the influence of each detection within the normal working temperature range on the scrap degree; β is the over-temperature influence coefficient, which represents the basic influence of each detection beyond the normal working temperature range on the scrap degree; k is the slope parameter, which controls the sensitivity of temperature influence; t i is the solder paste temperature at each test that exceeds the normal operating temperature range; t is the preset reference temperature, and the normal temperature range is [t min , t max ].

5. The liquid level detection device for selective welding equipment according to claim 4, characterized in that: in, α＝0.00006，β＝0.0085，r＝6.3。 6. The liquid level detection device for selective welding equipment according to claim 3, characterized in that: The control module also includes a counting unit for counting the number of detection instructions; When the number of detection instructions reaches a preset number, the scrap value calculation unit calculates a scrap value.

7. A method for detecting liquid level of selective welding equipment, characterized in that: The liquid level detection device for selective welding equipment according to any one of claims 1 to 6 comprises: Receive liquid level detection instructions and receive detection values ​​from laser sensors; Driving the tin furnace to a preset coordinate, and controlling the laser sensor to perform detection; Determining whether the detection value falls within a preset interval; If the detected value does not fall within the preset interval, an alarm message is issued.

8. The detection method according to claim 7, characterized in that Also includes: Calculate the scrap value based on historical test data, the tin liquid temperature curve and the normal operating temperature range of the laser sensor, wherein the tin liquid temperature curve is a function of temperature with respect to time; If the scrap value reaches a preset value, a replacement prompt message is issued.

9. The detection method according to claim 8, characterized in that: The scrap value is calculated based on the historical detection data, the tin liquid temperature curve and the normal operating temperature range of the laser sensor, including: Calculate a first proportional factor m% of the time length of the tin liquid temperature curve within the normal operating temperature range to the total time length, and a second proportional factor n% of the time length of the tin liquid temperature curve outside the normal operating temperature range to the total time length; Generate a first tin liquid temperature set in the historical detection data that is within the normal operating temperature range, and a second tin liquid temperature set in the historical detection data that is outside the normal operating temperature range; remove the first tin liquid temperature set in the range of [t, t max ]; remove the elements between [t max , 2t max -t]; the number of elements in the first tin liquid temperature set after removing the elements is p, and the number of elements in the second tin liquid temperature set after removing the elements is q; The scrap value k is calculated according to the following formula: Among them, α is the normal influence coefficient, which represents the influence of each detection within the normal working temperature range on the scrap degree; β is the over-temperature influence coefficient, which represents the basic influence of each detection beyond the normal working temperature range on the scrap degree; k is the slope parameter, which controls the sensitivity of temperature influence; t i is the solder paste temperature at each test that exceeds the normal operating temperature range; t is the preset reference temperature, and the normal temperature range is [t min , t max ].

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