CN211602209U

CN211602209U - Integrated digital thermocouple high-temperature sensor

Info

Publication number: CN211602209U
Application number: CN202020275857.5U
Authority: CN
Inventors: 周洋; 倪立; 李明亚; 王�华; 张祖力
Original assignee: Sook Automotive Components Jiangsu Co ltd
Current assignee: Shoukai High Tech Jiangsu Co ltd
Priority date: 2020-03-09
Filing date: 2020-03-09
Publication date: 2020-09-29
Anticipated expiration: 2030-03-09

Abstract

The utility model discloses an integrated form digital thermocouple high temperature sensor, including a plurality of thermocouple probes, many wires and an integrated circuit box, every thermocouple probe is connected to through a wire integrated circuit box, integrated circuit box is including gathering amplifier module, SPI, MCU, cold junction compensation module, CAN transceiver and power module, gather amplifier module and pass through SPI connects MCU, cold junction compensation module with the CAN transceiver is connected respectively MCU, power module provides the power for other each module. The utility model discloses simultaneous measurement multichannel temperature, the precision is higher.

Description

Integrated digital thermocouple high-temperature sensor

Technical Field

The utility model relates to a temperature-detecting system, in particular to install the integrated form digital thermocouple high temperature sensor who is used for detecting a plurality of position temperatures at automobile exhaust system, the highest temperature of detection can reach 1200 ℃.

Background

With the increasing tightening of national emission standards, many automobile or engine manufacturers have made many improvements to aftertreatment system technology. The high-temperature sensor is used for measuring the temperature of the key part of the aftertreatment system and transmitting the temperature to the ECU to make corresponding judgment.

Currently, high temperature sensors include platinum resistors, thermistors, and thermocouples. The platinum resistor and the thermistor have narrow temperature measuring ranges, the linear relation between the resistance value and the temperature of a high-temperature area is poor, and the temperature measuring range, the output linearity and the response time of the thermocouple are relatively good. In the market, the platinum resistor and the thermistor high-temperature sensor convert resistance signals into voltage signals through two signal wires and transmit the voltage signals to an automobile ECU.

There are three types of thermocouples, open-ended, sheathed, and insulated. The open-end thermocouple has quick response time but can not be applied to corrosive environment, the shell-connected thermocouple has quick response time but weak electromagnetic interference carrying capacity, and the insulated thermocouple has relatively slow response time but has good electrical insulation performance and environmental interference resistance.

Disclosure of Invention

The purpose of the invention is as follows: the utility model discloses to the problem that prior art exists, provide an integrated form digital thermocouple high temperature sensor, can measure the high temperature that reaches 1200 ℃, but and simultaneous measurement multichannel temperature, the precision is higher.

The technical scheme is as follows: integrated form digital thermocouple high temperature sensor include a plurality of thermocouple probes, many wires and an integrated circuit box, every thermocouple probe is connected to through a wire integrated circuit box, integrated circuit box is including gathering amplifier module, SPI, MCU, cold junction compensation module, CAN transceiver and power module, gather amplifier module and pass through SPI connects MCU, cold junction compensation module and CAN transceiver connect respectively MCU, power module provides the power for other each module.

Furthermore, the thermocouple is an insulation type thermocouple, the outer diameter of the tip of the probe is 2mm, the outer wall of the probe is made of Inconel601 material, the insulation substance is MgO powder, the core wire is made of N-type or K-type nickel-chromium-nickel-silicon alloy, and the number of the probes is 2, 3 or 4. The material of the lead is consistent with that of the thermocouple core wire.

Furthermore, a DCDC chip is arranged in the power module, the input end of the DCDC chip is connected with a filter circuit, and a diode is arranged in the DCDC chip. And the output end of a DCDC chip of the power supply module is connected with a filter circuit and a voltage stabilizing circuit.

Furthermore, the cold end compensation module adopts PT100 thermal resistance temperature measurement to carry out cold end compensation.

Has the advantages that: compared with the prior art, the utility model, it is showing the advantage and is:

1. the temperature can be measured in multiple ways and can be selected;

2. the thermocouple probe structure ensures long service life, excellent output linearity and response time;

3. the circuit part is highly integrated and has a small structure;

4. the direct connection with CAN, installation and maintenance are more convenient, and the communication interference killing feature is stronger.

Drawings

Fig. 1 is a structural diagram of an integrated digital thermocouple high-temperature sensor provided by the present invention;

FIG. 2 is an enlarged schematic view of the tip of the thermocouple probe of FIG. 1;

FIG. 3 is a circuit block diagram of the integrated circuit box of FIG. 1;

FIG. 4 is a detailed circuit diagram of the acquisition amplification module and cold end compensation module of FIG. 3;

FIG. 5 is a detailed circuit diagram of the power module of FIG. 3;

fig. 6 is a schematic diagram of the present invention.

Detailed Description

The embodiment provides an integrated digital thermocouple high-temperature sensor, as shown in fig. 1, the integrated digital thermocouple high-temperature sensor comprises a plurality of thermocouple probes, a plurality of conducting wires and an integrated circuit box, each thermocouple probe is connected to the integrated circuit box through one conducting wire, each thermocouple probe is an insulating thermocouple probe, the outer diameter of a tip of each probe is 2mm through a stretching and diameter-changing process, as shown in fig. 2, the rapid thermal response performance can be ensured through the design of an extremely fine thermal sensing part, the outer wall of each probe is made of Inconel601 material, the insulating substance is MgO powder, and the core wire is made of N-type or K-type nickel-chromium-nickel-silicon alloy. The multi-channel thermocouple probe is used for detecting the temperature of different parts of the automobile aftertreatment system and can be 2-channel, 3-channel or 4-channel, the conducting wire is used for transmitting potential difference, and in order to avoid errors, the material of the conducting wire must be consistent with that of a thermocouple core wire.

As shown in fig. 3, the integrated circuit box includes an acquisition amplifying module, an SPI (serial peripheral Interface) communication module, an MCU, a cold end compensation module, a CAN (controller area Network, controllera Network, CAN) transceiver and a power module, the acquisition amplifying module is connected to the MCU through the SPI, the cold end compensation module and the CAN transceiver are respectively connected to the MCU, the MCU chip model is MAX6675, and the power module provides power for other modules. The integrated circuit box is used for collecting amplified signals, calibration signals and cold end compensation, and finally converting the signals into CAN signals and outputting the CAN signals to the automobile CAN line.

Fig. 4 shows a specific circuit of the acquisition and amplification module and the cold junction compensation module, the acquisition and amplification module mainly comprises a precision instrument amplifier INA114 and a peripheral circuit thereof, a REF102 precision reference power supply is used for providing a working voltage for the thermocouple, the cold junction compensation module adopts a PT100 thermal resistor to measure the cold junction temperature, and the electromotive force generated by the thermocouple after compensation is amplified by the precision instrument amplifier INA114 and then output.

Fig. 5 shows a specific circuit diagram of a power module, a DCDC chip is provided therein, a diode is provided inside the DCDC chip to prevent reverse connection of voltage, two filter capacitors C1 and C3 are provided at an input terminal of the power chip, which not only can filter noise in the supply voltage of the storage battery, but also can prevent the whole power module or even the whole sensor from failing due to a short circuit of the capacitor, a combination of a zener diode D1, an inductor L1, and capacitors C2 and C4 is provided at an output terminal of the power chip, which not only can stabilize the output voltage at 5V, but also can filter noise and noise at the output terminal, and can prevent the sudden termination of output due to drop of the input voltage.

The working principle of the embodiment is as follows: as shown in fig. 6, the multiple thermocouples generate weak potential difference corresponding to temperature through seebeck effect, enter the integrated circuit box, and after amplification and correction are performed through the acquisition and amplification module, the analog voltage signals are finally converted into digital signals, and then transmitted to the MCU through the SPI, and meanwhile, the cold junction compensation module measures the cold junction temperature through the PT100 thermal resistor, calculates temperature values through the measured voltage signals, performs cold junction compensation on the temperature acquired by the thermocouples, and finally the MCU obtains real temperature of the test points, and converts the digital signals into CAN signals through the CAN transceiver and outputs the CAN signals to the CAN line.

The above description is only a preferred embodiment of the present invention, and it should be noted that: for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. An integrated digital thermocouple high-temperature sensor, characterized in that: including a plurality of thermocouple probes, many wires and an integrated circuit box, every thermocouple probe is connected to through a wire integrated circuit box, integrated circuit box is including gathering enlarged module, SPI, MCU, cold junction compensation module, CAN transceiver and power module, gather enlarged module and pass through SPI connects MCU, cold junction compensation module with CAN transceiver connects respectively MCU, power module provides the power for other each module.

2. The integrated digital thermocouple high temperature sensor according to claim 1, wherein: the external diameter of the tip of the thermocouple probe is 2 mm.

3. The integrated digital thermocouple high temperature sensor according to claim 1, wherein: the thermocouple probe is an insulated thermocouple.

4. The integrated digital thermocouple high temperature sensor according to claim 1, wherein: the thermocouple probe is characterized in that the outer wall of the thermocouple probe is made of Inconel601 material, the insulating substance is MgO powder, and the core wire is made of N-type or K-type nickel-chromium-nickel-silicon alloy.

5. The integrated digital thermocouple high temperature sensor according to claim 1, wherein: the number of the thermocouple probes is 2, 3 or 4.

6. The integrated digital thermocouple high temperature sensor according to claim 1, wherein: the material of the lead is consistent with that of the thermocouple core wire.

7. The integrated digital thermocouple high temperature sensor according to claim 1, wherein: the power module is internally provided with a DCDC chip, the input end of the DCDC chip is connected with a filter circuit, and a diode is adopted in the DCDC chip.

8. The integrated digital thermocouple high temperature sensor according to claim 7, wherein: and the output end of a DCDC chip of the power supply module is connected with a filter circuit and a voltage stabilizing circuit.

9. The integrated digital thermocouple high temperature sensor according to claim 1, wherein: and the cold end compensation module adopts PT100 thermal resistance temperature measurement to carry out cold end compensation.