Temperature measuring device

Abstract

The utility model discloses a temperature measuring device, which is used for detecting the temperature in a reflow soldering furnace and comprises a cable protective sleeve; the plurality of temperature sensors are arranged in the cable protection sleeve, the cable ends of the temperature sensors are arranged in the cable protection sleeve, and the probe ends of the temperature sensors extend out of the cable protection sleeve so as to detect the temperature in the reflow soldering furnace; and any temperature sensor is in signal connection with the control mechanism through the MAX31855 circuit module, and the control mechanism is used for receiving a fault detection signal and a temperature conversion signal fed back by the MAX31855 circuit module and correspondingly performing alarm and numerical value output processing. The temperature measuring device is high in system integration level, can directly detect the temperature of the reflow soldering furnace, can timely know whether the temperature sensor is damaged and fails or not and timely give an alarm, and guarantees the accuracy, sensitivity and reliability of the measurement of the temperature of the inner cavity of the reflow soldering furnace.

Description

Technical Field

[0001] The utility model relates to the technical field of temperature detection, and more specifically to a temperature measuring device. Background Art

[0002] The furnace temperature measuring device is a device that measures the temperature inside the furnace in real time, making it easy to obtain the environment inside the furnace in a timely manner.

[0003] In the related art, the temperature sensor is fixed in the temperature sensor protective cover and then installed outside the cable protective cover to obtain the temperature inside the furnace through the temperature sensor. However, under this operation mode, the heat absorption problem caused by the heat capacity of the sensor protective cover will cause the temperature measured by the temperature sensor to lag behind the actual temperature, resulting in inaccurate temperature measurement inside the furnace; during use, the temperature sensor is encapsulated in the protective cover. When the temperature sensor is damaged and fails, the operator and equipment cannot detect it, resulting in distorted measurement data and affecting normal production.

[0004] In summary, how to provide a temperature measuring device that ensures the accuracy of temperature measurement in a furnace is a problem that needs to be urgently solved by those skilled in the art. Utility Model Content

[0005] In view of this, the purpose of the utility model is to provide a temperature measuring device with high system integration, which can directly detect the temperature of the reflow soldering furnace, promptly know whether the temperature sensor is damaged or failed and promptly alarm, thereby ensuring the accuracy, sensitivity and reliability of the measurement of the temperature inside the reflow soldering furnace.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A temperature measuring device for detecting the temperature in a reflow soldering furnace, comprising:

[0008] Cable protection cover;

[0009] A temperature sensor, wherein a plurality of the temperature sensors are disposed in the cable protective sheath, and a cable end of the temperature sensor is disposed in the cable protective sheath, and a probe end of the temperature sensor extends out of the cable protective sheath to detect the temperature in the reflow oven;

[0010] Control mechanism, any of the temperature sensors are connected to the control mechanism signal through the MAX31855 circuit module, and the control mechanism is used to receive the fault detection signal and temperature conversion signal fed back by the MAX31855 circuit module and perform corresponding alarm and numerical output processing.

[0011] Preferably, the cable protective sheath is provided with a hole area for the probe end of the temperature sensor to extend out, an insulating sleeve is installed on the hole area, and the probe end extends out of the insulating sleeve to detect the temperature in the reflow oven.

[0012] Preferably, a plurality of the temperature sensors are arranged at equal intervals in the cable protective sheath, and each of the temperature sensors corresponds to a group of the MAX31855 circuit modules.

[0013] Preferably, the control mechanism includes an MCU processing module, and any of the MAX31855 circuit modules is signal-connected to the MCU processing module via an SPI data bus. The MAX31855 circuit module can transmit the acquired temperature value and acquired fault information to the management computer.

[0014] Preferably, the MCU processing module is connected to a plurality of alarm modules, and each of the alarm modules is provided with an alarm indicator light of the temperature sensor corresponding thereto.

[0015] Preferably, signal transmission is achieved between the MCU processing module and the management computer via a conversion module, and the conversion module is an RS485 bus or a CAN bus.

[0016] Preferably, the MAX31855 circuit module includes: an internal cold-end compensation circuit, a fault detection circuit, and a thermocouple detection circuit. The internal cold-end compensation circuit, the fault detection circuit, and the thermocouple detection circuit are all connected to a digital control block through an analog-to-digital converter, and the digital control block is signal-connected to the MCU processing module.

[0017] Preferably, the circuit connecting the MAX31855 circuit module and the temperature sensor is further provided with a plurality of groups of capacitors for voltage stabilization and filtering.

[0018] The temperature measuring device provided by the utility model comprises a cable protective cover and a plurality of temperature sensors arranged inside the cable protective cover, the cable end of the sensor is arranged in the cable protective cover, and the probe end of the sensor extends out of the cable protective cover, so that the probe end of the temperature sensor can directly contact the chamber in the reflow soldering furnace, and the temperature of the environment is directly detected through the probe end, so as to improve the temperature sensing speed and the measurement accuracy; each temperature sensor is connected to the control mechanism signal through the MAX31855 circuit module, and the value measured by the temperature sensor is output through the MAX31855 circuit module, or the fault detection signal of the temperature sensor is transmitted to the control mechanism through the MAX31855 circuit module, and the control mechanism can timely alarm so that the operator can handle it in time. If the temperature sensor is short-circuited or broken, it can be handled in time to ensure the accuracy and effectiveness of the temperature detection data. In addition, the design of exposing the probe end is also convenient for the operator to perform daily safety inspections on the sensor, which greatly avoids the impact of temperature sensor damage on daily production. The above-mentioned temperature measuring device can directly detect the temperature of the reflow soldering furnace, and can promptly know whether the temperature sensor is damaged and invalid and give an alarm in time, thereby ensuring the accuracy and effectiveness of the measurement of the temperature inside the reflow soldering furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0020] Figure 1 This is a schematic diagram of the structure of the temperature measuring device provided by the utility model;

[0021] Figure 2 This is a schematic diagram of the arrangement of the temperature measuring device provided by the utility model;

[0022] Figure 3 A circuit diagram of the temperature measuring device provided by the utility model;

[0023] Figure 4 This is an operation flow chart of the temperature measuring device provided by the utility model;

[0024] Figure 5 The present invention provides a functional block diagram of the MAX31855 circuit module.

[0025] Figure 1-Figure 5 , the reference numerals include:

[0026] SPI data bus 1, cable protection cover 2, temperature sensor 3, insulation sleeve 4, capacitor 5, MAX31855 circuit module 6, MCU processing module 7, conversion module 8, management computer 9, alarm module 10, cable end 31, probe end 32. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] The core of the utility model is to provide a temperature measuring device with high system integration, which can directly detect the temperature of the reflow soldering furnace, timely know whether the temperature sensor is damaged and invalid and give an alarm in time, so as to ensure the accuracy and sensitivity of the measurement of the temperature inside the reflow soldering furnace.

[0029] The temperature measuring device provided by the utility model is used to detect the reflow soldering, including a cable protective cover 2, a temperature sensor 3, and a control mechanism. Please refer to Figure 1 , Figure 2 , Figure 4 .

[0030] A plurality of temperature sensors 3 are arranged in the cable protective sheath 2 . There is no restriction on the specific arrangement and the number of the temperature sensors 3 , and they can be flexibly designed according to actual needs.

[0031] Under the condition of using multiple temperature sensors 3, it is mainly convenient to measure the temperatures of different areas in the furnace cavity for comparison, thereby ensuring the reliability and effectiveness of the temperature measurement in the furnace cavity.

[0032] The cable end 31 of the temperature sensor 3 is arranged in the cable protective cover 2, and the cable protective cover 2 can form effective protection, such as insulation, dustproof, waterproof protection, etc. The probe end 32 of the temperature sensor 3 extends out of the cable protective cover 2 and directly contacts the air in the reflow oven to directly measure the ambient temperature of the reflow oven, so that the temperature sensor 3 can directly reflect the temperature in the reflow oven at this time, ensuring the timeliness, effectiveness, accuracy and sensitivity of the temperature measurement.

[0033] Since the probe end 32 of the temperature sensor 3 extends out of the cable protective cover 2, if the temperature sensor 3 is damaged, it can be discovered in time during the routine inspection of the operator, thereby avoiding the impact of component damage on the production process.

[0034] Furthermore, each temperature sensor 3 is connected to the control mechanism signal through the MAX31855 circuit module 6 (thermocouple to digital output converter). Specifically, the temperature signal of the temperature sensor 3 can be output to the control mechanism through the MAX31855 circuit module 6, so as to obtain the temperature value in the reflow oven; if the temperature sensor 3 is damaged, such as short circuit or open circuit, the fault detection module in the MAX31855 circuit module 6 can operate to obtain the fault condition of the temperature sensor 3 and feed back the fault condition to the control mechanism. The control mechanism can give an alarm in time to remind the operator to deal with it as soon as possible to avoid the impact of component damage on the production process and ensure the long-term accuracy and effectiveness of the temperature measurement in the oven.

[0035] Specifically, there is no limitation on the alarm method, which may be a warning light, a buzzer, a prompt sound, etc., as long as it can serve to remind the operator.

[0036] Optionally, the control mechanism may output the measured value of the temperature sensor 3 in the form of numerical display or multiple gear display, without specific limitation.

[0037] The temperature measuring device comprises a cable protective sleeve 2 and a plurality of temperature sensors 3 arranged therein, wherein the cable end 31 of the sensor is arranged in the cable protective sleeve 2, and the probe end 32 of the sensor extends out of the cable protective sleeve 2, so that the probe end 32 of the temperature sensor 3 can directly contact the chamber in the reflow soldering furnace, and directly detect the temperature of the environment through the probe end 32, so as to improve the temperature sensing speed and the measurement accuracy; each temperature sensor 3 is connected to the control mechanism signal through the MAX31855 circuit module 6, and the value measured by the temperature sensor 3 is output through the MAX31855 circuit module 6, or the fault detection signal of the temperature sensor 3 is transmitted to the control mechanism through the MAX31855 circuit module 6, and the control mechanism can timely alarm so that the operator can handle it in time. If the temperature sensor 3 is short-circuited or open-circuited, it can be handled in time to ensure the accuracy and effectiveness of the temperature detection data. In addition, the design of the exposed probe end 32 is also convenient for the operator to perform daily safety inspections on the sensor, which greatly avoids the impact of temperature sensor damage on daily production. The temperature measuring device can directly detect the temperature of the reflow oven, and can timely know whether the temperature sensor is damaged and invalid and give an alarm in time, thereby improving the sensitivity and accuracy of the measurement of the temperature in the reflow oven cavity.

[0038] Based on the above embodiment, a hole area is provided on the cable protective sheath 2 for the probe end 31 of the temperature sensor 3 to extend out, an insulating sleeve 4 is installed on the hole area, and the probe end 32 extends out of the insulating sleeve 4 to detect the temperature in the reflow oven.

[0039] Please refer to Figure 1 , Figure 2A hole area is opened on the cable protective cover 2, that is, a hole is opened on the protective cover. The size and shape of the specific hole are not limited. An insulating sleeve 4 with good insulation effect is installed on the hole area. The insulating sleeve 4 blocks the hole and is used for the probe end 32 of the temperature sensor 3 to extend to detect the temperature in the reflow oven to ensure the safety and reliability of the operation.

[0040] In this embodiment, if multiple temperature sensors 3 are provided, multiple holes are provided on the corresponding cable protective cover 2 , which need to correspond one to one.

[0041] On the basis of any of the above embodiments, a plurality of temperature sensors 3 are arranged at equal intervals in the cable protective sheath 2 , and each temperature sensor 3 corresponds to a group of MAX31855 circuit modules 6 .

[0042] Please refer to Figure 2 , Figure 4 When used for temperature measurement in a reflow oven, the distance A between two adjacent temperature sensors 3 is preferably 25 cm, so as to more comprehensively detect the temperature distribution in the oven.

[0043] Each temperature sensor 3 corresponds to a group of MAX31855 circuit modules 6. The temperature of each group of temperature sensors 3 can be obtained through the control mechanism, and the fault condition of each group of temperature sensors 3 can also be timely known through the control mechanism, ensuring the reliability and stability of the entire temperature test process and ensuring the accuracy and effectiveness of the reflow oven temperature detection.

[0044] Based on any of the above embodiments, the control mechanism includes an MCU processing module 7 (Microcontroller Unit), and any MAX31855 circuit module 6 is connected to the MCU processing module 7 signal through the SPI data bus 1. The MAX31855 circuit module 6 can transmit the acquired temperature value and fault information to the management computer 9.

[0045] Please refer to Figure 3 , Figure 4 , the functions of MCU processing module 7 in the whole temperature measurement process are:

[0046] Decode the temperature value measured by the temperature sensor 3 transmitted by the MAX31855 circuit module 6, and then upload the temperature value to the management computer 9;

[0047] The fault condition of the temperature sensor 3 detected by the MAX31855 circuit module 6 is obtained, compiled into instructions and uploaded to the management computer 9. At the same time, the MCU processing module 7 performs alarm processing on the faulty temperature sensor to prompt the on-site staff to handle it as soon as possible.

[0048] During the temperature measurement process, each time a temperature conversion is completed, the MAX31855 circuit module 6 sends the temperature measurement value and the temperature sensor fault condition to the MCU processing module 7 through the SPI data bus 1 (Serial Peripheral Interface) for data processing, and further compiles the temperature value and the fault condition into instructions and transmits them to the management computer 9.

[0049] On the basis of any of the above embodiments, the MCU processing module 7 is connected to a plurality of alarm modules 10 , and each alarm module 10 is provided with an alarm indicator light of the temperature sensor 3 corresponding thereto.

[0050] When the MAX31855 circuit module 6 obtains the fault condition of the temperature sensor 3, it is transmitted to the management computer 9 after being programmed into a command, and further an alarm is emitted through the alarm indicator light on the alarm module 10 to prompt the on-site operator to handle it as soon as possible.

[0051] Optionally, the alarm indicator light can be set to different brightness, different colors, flashing, etc., to achieve a more obvious warning effect, so that on-site operators can quickly and promptly be informed and take timely measures to ensure the stability of the production process.

[0052] The MCU processing module 7 is connected to a plurality of alarm modules 10, the number of which corresponds to the number of the temperature sensors 3. The fault information of each temperature sensor 3 can be obtained in time to avoid the influence of sensor damage on the production process.

[0053] On the basis of any of the above embodiments, signal transmission is achieved between the MCU processing module 7 and the management computer 9 via a conversion module 8, and the conversion module 8 is an RS485 bus or a CAN bus.

[0054] Please refer to Figure 3 , Figure 4 The MCU processing module 7 and the management computer 9 realize signal transmission through the conversion module 8, and the temperature value and fault condition processed by the MCU processing module 7 are fed back to the management computer 9 through the conversion module 8.

[0055] As a preferred real-time mode, the conversion module 8 is a RS485 bus (Recommended standard 485) or a CAN bus (Controller Area Network).

[0056] Based on any of the above embodiments, the MAX31855 circuit module 6 includes: an internal cold-end compensation circuit, a fault detection circuit, and a thermocouple detection circuit. The internal cold-end compensation circuit, the fault detection circuit, and the thermocouple detection circuit are all connected to the digital control block through an analog-to-digital converter, and the digital control block is connected to the MCU processing module 7 signal.

[0057] Please refer to Figure 3 , Figure 4 , Figure 5 The temperature sensor 3 is a thermocouple, which is mainly a K-type thermocouple. The MAX31855 circuit module 6 is used to implement analog amplification, cold-end compensation, fault detection, and analog / digital conversion of the temperature sensor 3.

[0058] The MAX31855 circuit module 6 performs three main operations: internal cold-junction temperature conversion, external thermocouple temperature conversion, and thermocouple fault detection.

[0059] Combine the following Figure 3 , Figure 4 , Figure 5 , the processes of these three operations are described in detail:

[0060] Internal cold junction temperature conversion: Disconnect the external thermocouple signal switch S4, open the cold junction compensation circuit switch S5, close the switch S3 to keep T- connected to the internal reference ground GND, and disconnect the switches S1 and S2 to disconnect the fault detection circuit.

[0061] External thermocouple temperature conversion: At this time, no fault detection and internal cold-end temperature conversion are performed. Switches S1, S2, and S5 are disconnected, and switch S3 is closed to keep T- connected to the internal reference ground GND. Switch S4 is closed so that the detection signal of the thermocouple (i.e., temperature sensor 3) is processed by the amplifier and sent to the analog-to-digital converter, so that the analog-to-digital converter can process the detection voltage at both ends of T+ and T-, and convert it into a digital signal, and send it to the digital control block; further, the SPI data bus 1 is connected through the SO port of the digital control block, and the temperature value is transmitted to the management computer 9.

[0062] Thermocouple fault detection: At this time, the internal cold end temperature conversion and the external thermocouple temperature conversion are not performed. The switches S4 and S5 are opened, and the switch S3 is closed to keep T- connected to the internal reference ground GND. The switches S1 and S2 are closed to turn on the fault detection circuit. Corresponding reference voltages are set to determine whether there is a fault. The fault detection circuit tests the short circuit condition between the T+ and T- inputs and the power supply voltage VCC or the internal reference ground GND, as well as the thermocouple open circuit fault, and sends it to the digital control block after processing by the analog-to-digital converter. The fault condition is further sent to the MCU processing module 7 for alarm and transmitted to the management computer 9.

[0063] On the basis of any of the above embodiments, a plurality of groups of capacitors 5 are further provided in the circuit connecting the MAX31855 circuit module 6 and the temperature sensor 3 for voltage stabilization and filtering.

[0064] Please refer to Figure 3 , Figure 4 , Figure 5 , capacitor 5 is provided on the line connecting the GND pin and VCC pin of the MAX31855 circuit module 6 and the thermocouple end. The specific setting position and connection are detailed in the figure. By setting capacitor 5 and utilizing the charging and discharging of capacitor 5, the stability of the output voltage is guaranteed, and the accuracy and reliability of the detection are guaranteed.

[0065] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0066] The above is a detailed introduction to a temperature measuring device provided by the utility model. This article uses specific examples to illustrate the principle and implementation method of the utility model. The description of the above embodiment is only used to help understand the method and core idea of ​​the utility model. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, the utility model can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.

Claims

1. A temperature measuring device for detecting the temperature in a reflow oven, characterized in that: include: Cable protection cover (2); A temperature sensor (3), wherein a plurality of the temperature sensors (3) are arranged in the cable protective cover (2), and a cable end (31) of the temperature sensor (3) is arranged in the cable protective cover (2), and a probe end (32) of the temperature sensor (3) extends out of the cable protective cover (2) to detect the temperature in the reflow oven; A control mechanism, wherein any of the temperature sensors (3) is connected to the control mechanism by signal via a MAX31855 circuit module (6), and the control mechanism is used to receive a fault detection signal and a temperature conversion signal fed back by the MAX31855 circuit module (6) and to perform corresponding alarm and numerical output processing.

2. The temperature measuring device according to claim 1, characterized in that: The cable protective sheath (2) is provided with a hole area for the probe end (32) of the temperature sensor (3) to extend out, an insulating sleeve (4) is installed on the hole area, and the probe end (32) extends out of the insulating sleeve (4) to detect the temperature in the reflow oven.

3. The temperature measuring device according to claim 2, characterized in that: A plurality of the temperature sensors (3) are arranged at equal intervals in the cable protective cover (2), and each of the temperature sensors (3) corresponds to a group of the MAX31855 circuit modules (6).

4. The temperature measuring device according to claim 3, characterized in that: The control mechanism comprises an MCU processing module (7), and any of the MAX31855 circuit modules (6) is connected to the MCU processing module (7) by signal via an SPI data bus (1). The MAX31855 circuit module (6) can transmit the acquired temperature value and acquired fault information to a management computer (9).

5. The temperature measuring device according to claim 4, characterized in that: The MCU processing module (7) is connected to a plurality of alarm modules (10), and each of the alarm modules (10) is provided with an alarm indicator light of the temperature sensor (3) corresponding thereto.

6. The temperature measuring device according to claim 5, characterized in that: Signal transmission is achieved between the MCU processing module (7) and the management computer (9) via a conversion module (8), and the conversion module (8) is an RS485 bus or a CAN bus.

7. The temperature measuring device according to claim 6, characterized in that: The MAX31855 circuit module (6) comprises: an internal cold end compensation circuit, a fault detection circuit, and a thermocouple detection circuit. The internal cold end compensation circuit, the fault detection circuit, and the thermocouple detection circuit are all connected to a digital control block via an analog-to-digital converter, and the digital control block is signal-connected to the MCU processing module (7).

8. The temperature measuring device according to claim 7, characterized in that: The circuit connecting the MAX31855 circuit module (6) and the temperature sensor (3) is also provided with a plurality of groups of capacitors (5) for voltage stabilization and filtering.

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