Pressure and temperature detection device

Abstract

The utility model provides a pressure and temperature detection device. According to the pressure and temperature detection device provided by the utility model, all components except the outer sealing O-shaped ring are fastened in the circular groove cavity of the metal base in a hemming manner, so that each component of the device, including a welding spot of each component, is not exposed in an area which can be directly contacted with natural gas, and the condition of oxidation of the components is reduced. The important component NTC thermistor pin of the device is flatly attached to and welded to the surface of the PCB bonding pad at the lower end of the PCB and is not affected by vibration during operation of the engine, the situations of loss or short circuit of NTC thermistor temperature signals and the like are reduced, and the pressure and temperature detection device is good in long-term stability and reliability.

Description

Technical Field

[0001] The utility model relates to the technical field of natural gas engines, in particular to a pressure and temperature detection device. Background Art

[0002] A natural gas engine is an engine that uses natural gas as fuel. The main advantages of natural gas engines include abundant resources, low emissions, and low prices, making it considered a promising fuel. Existing detection solutions for natural gas pressure and temperature sensors in natural gas engine cylinders, gas rails, and other pipelines generally utilize a pressure-capacitive ceramic core. Two windows are added to the ceramic core's sensing diaphragm, and a copper layer is placed within the two windows to enable electrical contact with the NTC thermistor pins. This contact is achieved by pressing with an elastic spring. However, because the contact area is exposed to the natural gas medium being measured, vibrations generated during engine operation can easily cause the elastic spring to resonate and oxidize the contacts. Furthermore, moisture in the high-pressure natural gas easily adheres to the exposed contacts and leads, causing the NTC thermistor to lose its temperature signal or short-circuit. Utility Model Content

[0003] The present invention aims to solve the technical problems raised in the above background technology and provides a pressure and temperature detection device.

[0004] The utility model solves the above technical problems through the following technical solutions:

[0005] The utility model provides a pressure and temperature detection device. The pressure and temperature detection device comprises: a metal base and an NTC thermistor. The metal base is provided with a circular groove cavity, and a connector plug is provided inside the circular groove cavity. The upper end of the connector plug is electrically connected to a new natural gas engine, and the lower end is assembled and welded with a flexible circuit board.

[0006] A pressure module is provided at the lower end of the flexible circuit board, and the pressure module is connected to the NTC thermistor.

[0007] Preferably, the pressure module is connected to the NTC thermistor via protective glue.

[0008] Preferably, the pressure module includes a PCB board, a conditioning chip, a MEMS pressure chip and a protection circuit;

[0009] The conditioning chip and the protection circuit are arranged on the back side of the PCB board;

[0010] The MEMS pressure chip is arranged on the front side of the PCB board.

[0011] Preferably, a soldering pad is further provided on the front of the PCB board, and the soldering pad is used for flat soldering with the pins of the NTC thermistor.

[0012] Preferably, a bracket is provided below the pressure module, the bracket is assembled flatly with the PCB board, and an adhesive sealant is applied to the assembly gap.

[0013] Preferably, a circular groove is provided at the connection between the bracket and the PCB board, and silicone gel is filled in the circular groove.

[0014] Preferably, a tubular body is provided at the lower end of the bracket, and the tubular body passes through a circular hole provided at the lower end of the metal base to contact the natural gas medium to be measured.

[0015] Preferably, discs are provided on the periphery of both sides of the bracket, and the discs are in contact and sealed with the metal base through inner sealing rings.

[0016] Preferably, a threaded groove is provided at the lower end of the metal base, and the threaded groove is used to assemble an outer sealing ring.

[0017] The positive progressive effect of the present invention is that the present invention provides a pressure and temperature detection device. The pressure and temperature detection device includes: a metal base, an NTC thermistor, a circular groove cavity provided on the metal base, a connector plug provided inside the circular groove cavity, the upper end of the connector plug is electrically connected to the new natural gas engine, and the lower end is assembled and welded with a flexible circuit board; the lower end of the flexible circuit board is provided with a pressure module, and the pressure module is connected to the NTC thermistor. The pressure and temperature detection device of the present invention uses a crimping method to fasten all components except the sealing O-ring in the circular groove cavity of the metal base, so that the various components of the device, including the solder joints of each component, are not exposed in the area that can be directly contacted by natural gas, reducing the oxidation of components. The pins of the NTC thermistor, an important component of the device, are flatly attached to the surface of the PCB pad at the lower end of the PCB board and welded, and will not be affected by the vibration during engine operation, reducing the loss or short circuit of the NTC thermistor temperature signal, so that the pressure and temperature detection device has good long-term stability and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of a pressure and temperature detection device according to an embodiment of the present invention.

[0019] Figure 2 This is a detailed structural diagram of the pressure and temperature detection device according to an embodiment of the present invention.

[0020] Legend: 1. Metal base; 2. Circular groove cavity; 3. Connector plug; 4. Flexible circuit board; 5. Pressure module; 6. NTC thermistor; 7. Bracket; 8. Inner sealing ring; 9. Outer sealing ring; 10. Adhesive sealant; 31. Pin terminal; 51. PCB board; 52. MEMS pressure chip. DETAILED DESCRIPTION

[0021] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0022] Example 1

[0023] like Figure 1 As shown, this embodiment provides a pressure and temperature detection device. The pressure and temperature detection device comprises: a metal base 1, a circular groove cavity 2, a connector plug 3, a flexible circuit board 4, a pressure module 5, and an NTC thermistor 6. The metal base 1 is provided with a circular groove cavity 2, within which a connector plug 3 is located. The upper end of the connector plug 3 is electrically connected to the new natural gas engine, and the lower end is assembled and welded with a flexible circuit board 4. The lower end of the flexible circuit board 4 is provided with a pressure module 5, which is connected to the NTC thermistor 6. The pressure module 5 and the NTC thermistor 6 are connected via protective adhesive. In this embodiment, the upper end of the connector plug 3 is provided with a female plug structure that adapts to a specific model of external connector, achieving electrical connection between the pressure and temperature detection device and the new natural gas engine system. The lower end of the connector plug 3 is provided with a groove to facilitate the assembly and welding of the flexible circuit board 4. The connector plug 3 also has four pin terminals 31, which correspond to the through-hole pads on the welding machine pressure module 5, ensuring stable welding between the connector plug 3 and the pressure module 5.

[0024] In this embodiment, if Figure 2 As shown, pressure module 5 includes a PCB 51 and a MEMS pressure chip 52. The conditioning chip and protection circuit are located on the back of PCB 51, while the MEMS pressure chip 52 is located on the front of PCB 51. Specifically, the back of PCB 51 has four via pads, which correspond to the four pads at the bottom of flexible circuit board 4, ensuring a tight connection between flexible circuit board 4 and PCB 51.

[0025] In this embodiment, if Figure 2 As shown, the front of the PCB board 51 is also provided with a pad position, which is used for flat welding with the pins of the NTC thermistor 6; the front of the PCB board 51 is provided with two rectangular pad positions for flat welding of the NTC thermistor pins.

[0026] In this embodiment, if Figure 2As shown, a bracket 7 is positioned beneath the pressure module 5. The bracket 7 is assembled flush with the PCB 51, and an adhesive sealant 10 is applied to the assembly gap. A circular groove is provided at the connection between the bracket 7 and the PCB 51, and silicone gel is potted in the circular groove. Specifically, the PCB 51 and bracket 7 are assembled flush with each other, and a complete circle of adhesive sealant 10 is applied to a designated area of ​​the assembly gap to ensure bonding stability between the PCB 51 and bracket 7 and to ensure a tight seal in the assembly gap. After the PCB 51 and bracket 7 are assembled and bonded, a circular groove is formed. A certain amount of silicone gel is potted in this circular groove. The silicone gel can cover the pins 6 of the NTC thermistor, the pins 53 of the MEMS pressure chip, and other exposed pins and solder joints, ensuring that these pins and solder joints are not affected by contamination and corrosion from the natural gas medium being measured. No vias should be installed in the circular groove formed after the PCB 51 and bracket 7 are assembled and bonded to further ensure the tightness of this area.

[0027] In this embodiment, if Figure 2 As shown, a tubular body is provided at the lower end of bracket 7. This tubular body passes through a circular hole provided at the lower end of metal base 1 to contact the natural gas medium being measured. Specifically, a long tubular structure is provided at the lower end of bracket 7. This tubular structure is used to secure and protect the NTC thermistor 6 probe. A circular hole is provided at the lower end of metal base 1, allowing the tubular structure, which secures and protects the NTC thermistor 6 probe, to pass through and extend into the natural gas medium being measured.

[0028] In this embodiment, if Figure 2 As shown, discs are provided on both sides of the bracket 7, which are sealed to the metal base 1 via inner sealing rings 8. The inner sealing rings 8 are sealing O-rings that seal the bracket 7 and the metal base 1, ensuring that the natural gas being measured does not leak from the pressure and temperature detection device, thereby preventing leakage from affecting the detection results.

[0029] In this embodiment, if Figure 2 As shown, the lower end of the metal base 1 is provided with a threaded groove for assembling an outer sealing ring 9. Specifically, a threaded structure of a specific specification is provided at the lower end of the metal base 1, and a threaded groove is provided at the root of the thread for assembling the outer sealing ring 9 to ensure the sealing between the pressure and temperature detection device and the measured pipeline after installation; the outer sealing ring 9 is a sealing O-ring.

[0030] This embodiment provides a pressure and temperature detection device. This device uses a crimping method to secure all components, except for the sealing O-ring, within a circular groove within a metal base. This ensures that the device's components, including their solder joints, are not exposed to areas directly exposed to natural gas, minimizing component oxidation. The pins of the NTC thermistor, a key component of the device, are soldered flush with the PCB pad surface at the bottom of the PCB board. This protects the device from vibrations during engine operation, minimizing the risk of NTC thermistor temperature signal loss or short circuits, and ensuring long-term stability and reliability.

[0031] The working principle of the present invention is as follows: the natural gas medium to be measured enters the sensing hole of the MEMS pressure chip 52 through the circular hole in the threaded lower end of the metal base 1, thereby realizing pressure transmission; the MEMS pressure chip 52 converts the sensed pressure of the natural gas to be measured into a voltage signal, transmits it to the conditioning chip on the back of the PCB board 51 for signal processing and conversion, and outputs the final voltage signal to the external natural gas engine system through the electronic connection between the flexible circuit board 4 and the connector plug 3; the NTC thermistor 6 probe extends into the natural gas medium to be measured, can timely sense the temperature of the natural gas medium to be measured, and outputs the temperature signal to the external natural gas engine system through the electrical connection between the PCB board 51, the flexible circuit board 4 and the connector plug 3.

[0032] Although specific embodiments of the present invention have been described above, those skilled in the art will appreciate that these are merely illustrative and that the scope of protection of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, and such changes and modifications are intended to fall within the scope of protection of the present invention.

Claims

1. A pressure and temperature detection device, applied to a new natural gas engine, characterized in that: The pressure and temperature detection device includes: a metal base and an NTC thermistor. The metal base is provided with a circular groove cavity. A connector plug is provided inside the circular groove cavity. The upper end of the connector plug is electrically connected to the new natural gas engine, and the lower end is assembled and welded with a flexible circuit board. A pressure module is provided at the lower end of the flexible circuit board, and the pressure module is connected to the NTC thermistor.

2. The pressure and temperature detection device according to claim 1, wherein: The pressure module is connected to the NTC thermistor via protective glue.

3. The pressure and temperature detection device according to claim 2, wherein: The pressure module includes a PCB board, a conditioning chip, a MEMS pressure chip and a protection circuit; The conditioning chip and the protection circuit are arranged on the back side of the PCB board; The MEMS pressure chip is arranged on the front side of the PCB board.

4. The pressure and temperature detection device according to claim 3, characterized in that: The front of the PCB board is also provided with a soldering pad position, and the soldering pad position is used for flat soldering with the pins of the NTC thermistor.

5. The pressure and temperature detection device according to claim 4, characterized in that: A bracket is provided below the pressure module, and the bracket is assembled flatly with the PCB board, and an adhesive sealant is applied to the assembly gap.

6. The pressure and temperature detection device according to claim 5, characterized in that: A circular groove is provided at the connection between the bracket and the PCB board, and silicone gel is filled in the circular groove.

7. The pressure and temperature detection device according to claim 6, characterized in that: A tubular body is provided at the lower end of the bracket, and the tubular body passes through a circular hole provided at the lower end of the metal base and contacts the natural gas medium to be measured.

8. The pressure and temperature detection device according to claim 6, characterized in that: Discs are provided on the periphery of both sides of the bracket, and the discs are in contact and sealed with the metal base through inner sealing rings.

9. The pressure and temperature detection device according to claim 1, wherein: A threaded groove is provided at the lower end of the metal base, and the threaded groove is used for assembling an outer sealing ring.

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