Temperature and humidity pressure sensor capable of preventing short circuit and icing

Abstract

The utility model relates to the technical field of sensors, in particular to a temperature and humidity pressure sensor capable of preventing short circuit and icing. Comprising a packaging shell, the top of which is glued with a buckling cover; the printed circuit board is axially inserted into the shaft cavity of the packaging shell; the sealing ring is arranged on the printed circuit board in a sleeving mode, and the outer diameter edge of the sealing ring abuts against the inner side wall of the shaft cavity of the packaging shell in a sealing mode so that the shaft cavity of the shell can be divided into an upper cavity body and a lower cavity body; and the heating filter screen cylinder is formed by weaving nichrome heating wires, is coaxially inserted into the shaft cavity of the packaging shell and is propped against the inner side wall of the shaft cavity, and the heating filter screen cylinder is positioned below the sealing ring. The printed circuit board further comprises a thermistor, a humidity chip and a pressure chip device which are welded. According to the utility model, the protection functions of short circuit prevention and icing prevention can be achieved by reducing condensate water and water vapor in the sensing area of the sensor in a non-working state.

Description

Technical Field

[0001] The utility model relates to the technical field of sensors, in particular to a temperature, humidity and pressure sensor which is short-circuit and icing-proof. Background Art

[0002] Temperature and humidity pressure sensors are used in natural gas engine systems to measure the intake pressure, temperature and humidity in the pipeline. All signals are output to the ECU through the CAN bus. The ECU corrects the actual control of the air-fuel ratio and the natural gas supply according to the measured pressure, temperature and humidity to make the engine run in the best state. The sensor is installed on the pipeline between the air filter and the supercharger. Due to the special working environment, the sensor is easily affected by the ambient temperature and humidity, and condensed water or water vapor is generated in the detection sensing area. These condensed water or water vapor will affect the operation of the sensor, such as causing a short circuit in the internal circuit of the sensor or ice formation under low temperature conditions, causing the sensor to fail to work properly.

[0003] Considering that the impact of condensed water and water vapor sensors is mainly caused by freezing when the product is not in working state. In working state, due to the influence of heat transfer of engine temperature, the sensor does not freeze. Therefore, it is necessary to develop a temperature, humidity and pressure sensor structure that can protect the sensor by reducing condensed water and water vapor in non-working state. Utility Model Content

[0004] The utility model aims to provide a temperature, humidity and pressure sensor that is resistant to short circuit and icing, which can achieve the protection functions of short circuit and icing by reducing condensed water and water vapor in the sensor sensing area in a non-working state.

[0005] In order to solve the above technical problems, the utility model provides a temperature, humidity and pressure sensor that is short-circuit and icing-proof, comprising:

[0006] A package housing with a snap-fit ​​cover glued to the top;

[0007] A printed circuit board is axially inserted into the axial cavity of the packaging shell;

[0008] A sealing ring is sleeved on the printed circuit board, and the outer diameter edge of the sealing ring is in contact and sealed with the inner side wall of the axial cavity of the packaging shell to divide the axial cavity of the packaging shell into an upper cavity and a lower cavity;

[0009] The heating filter cylinder is made of braided nickel-chromium alloy heating wires, coaxially inserted into the shaft cavity of the packaging shell, and abuts against the inner wall of the shaft cavity, and the heating filter cylinder is located below the sealing ring.

[0010] Preferably, the printed circuit board also includes welded thermistors, humidity chips and pressure chip devices to achieve measurement of temperature, humidity and pressure.

[0011] Preferably, the sealing ring comprises: a cylinder and a raised ring; the raised ring is integrally formed on the circumferential wall of the cylinder, and a through slot is provided on the top of the cylinder for plugging and mounting with the printed circuit board.

[0012] Preferably, it further comprises a slit groove opened in the radial direction of the sealing ring, wherein the slit groove is perpendicular to the long side direction of the rectangle of the through slot hole and divides the long side of the rectangle of the through slot hole.

[0013] Preferably, the two symmetrical side wall ends of the printed circuit board further include U-shaped grooves for matching and embedding with the sealing ring.

[0014] Preferably, it further comprises four electrical contacts symmetrically arranged on the printed circuit board, and the upper and lower two electrical contacts on each side are respectively positive contacts or negative contacts.

[0015] Preferably, the four electrical contacts are in contact with the inner wall of the heating filter cylinder, so as to achieve electrical conduction to the heating filter cylinder through the printed circuit board.

[0016] Preferably, the outer wall of the axial cavity of the packaging shell further includes an array of large-diameter slot holes opened in the circumferential direction.

[0017] Compared with the prior art, the utility model has the following beneficial effects:

[0018] The utility model can prevent foreign impurities from entering the lower cavity by heating the filter cylinder, and prevent the friction with thermistors, humidity chips, pressure chips and other components on the printed circuit board, causing component wear and short circuit. When the sensor is not working, the filter cylinder is heated to remove the condensed water and water vapor accumulated in the sensing area inside the shaft cavity, thereby preventing freezing and short circuit. In addition, by designing the structure of the sealing ring, the shaft cavity of the housing is divided into an upper cavity and a lower cavity, so as to ensure that the external medium cannot enter the upper cavity, and to ensure that the components such as the circuit connection terminals in the upper cavity are not corroded by external gases or moisture enters to cause short circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a cross-sectional view of the temperature, humidity and pressure sensor provided by the utility model.

[0020] Figure 2 This is a side view of the temperature, humidity and pressure sensor provided by the utility model.

[0021] Figure 3This is a structural diagram of the printed circuit board, sealing ring and heating filter cylinder provided by the utility model.

[0022] Figure 4 This is an exploded view of the structure of the printed circuit board and the sealing ring provided by the utility model.

[0023] In the figure: 1-encapsulation shell, 11-slot grid hole, 12-connection terminal, 13-socket, 14-metal pin, 2-snap-on cover, 3-printed circuit board, 31-electrical contact, 4-sealing ring, 41-cylinder, 42-raised ring, 43-through slot hole, 44-slit slot, 5-heating filter cylinder, 6-U-shaped slot. DETAILED DESCRIPTION

[0024] The utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the utility model will become clearer. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the utility model.

[0025] like Figures 1 to 4 As shown, the embodiment of the utility model provides a temperature, humidity and pressure sensor that is short-circuit and icing-proof, comprising: a packaging shell 1, with a snap-on cover 2 glued on the top; a printed circuit board 3, axially plugged into the axial cavity of the packaging shell 1, with a connecting terminal 12 welded on the top, and electrically connected to a metal pin 14 in an integrated socket 13 on the packaging shell 1 through the connecting terminal 12; a sealing ring 4, sleeved on the printed circuit board 3, and the outer diameter edge of the sealing ring 4 is abutted and sealed against the inner side wall of the axial cavity of the packaging shell 1, so as to divide the axial cavity of the packaging shell 1 into an upper cavity and a lower cavity. The cavity is to ensure that the external medium cannot enter the upper cavity, and to ensure that the circuit connection terminals 12 and other components in the upper cavity are not corroded by external gases or moisture entering to cause short circuits; the heating filter cylinder 5 is made of nickel-chromium alloy heating wire, coaxially plugged into the axial cavity of the packaging shell 1, and abutted against the inner wall of the axial cavity, and the heating filter cylinder 5 is located below the sealing ring 4; the heating filter cylinder 5 can prevent external impurities from entering the lower cavity, and rubbing against thermistors, humidity chips, pressure chips and other components on the printed circuit board 3 to cause component wear, short circuits, etc. When the sensor is not working, it removes condensed water and water vapor accumulated in the axial cavity by self-heating, which plays a role in preventing freezing and short circuits.

[0026] The printed circuit board 3 also includes welded thermistors, humidity chips and pressure chips to measure temperature, humidity and pressure. The thermistors, humidity chips and pressure chips are located below the sealing ring 4 .

[0027] The sealing ring 4 includes: a cylindrical body 41 and a raised ring 42; the raised ring 42 is integrally formed on the circumferential wall of the cylindrical body 41, and a through slot 43 is provided on the top of the cylindrical body 41 for plugging and installing with the printed circuit board 3. It also includes a slit groove 44 provided along the radial direction of the sealing ring 4, and the slit groove 44 is perpendicular to the long side direction of the rectangle through the slot 43, and divides the long side of the rectangle through the slot 43. The two symmetrical side wall ends of the printed circuit board 3 also include U-shaped grooves 6 provided for matching and embedding with the sealing ring 4. When installing the sealing ring 4, the slit groove 44 of the sealing ring 4 can be opened by applying force, and then the through slot 43 is used to be sleeved on the U-shaped groove 6 of the printed circuit board 3, so that the top and bottom of the cylindrical body 41 abut against the upper and lower inner walls of the U-shaped groove 6, and the outer diameter edge of the raised ring 42 contacts the axial cavity of the package shell 1 to achieve sealing. In addition, the slit groove 44 structure designed above will not cause leakage because the raised ring 42 will be subjected to extrusion force when the printed circuit board 3 and the sealing ring 4 are installed in the axial cavity of the packaging shell 1, thereby squeezing the gap of the slit groove 44.

[0028] It also includes four electrical contacts 31 symmetrically arranged on the printed circuit board 3, and the upper and lower electrical contacts 31 on each side are respectively positive contacts or negative contacts. The four electrical contacts 31 are abutted against the inner wall of the heating filter cylinder 5 to achieve electrical conduction of the heating filter cylinder 5 through the printed circuit board 3. When the printed circuit board 3 is inserted, the printed circuit board 3 is abutted and electrically connected with the inner wall of its heating filter cylinder 5 through the four electrical contacts 31. When the assembly is completed, the heating filter cylinder 5 and the printed circuit board 3 are electrically connected. When the whole vehicle transmits a shutdown signal to the sensor, that is, through the CAN signal high and the CAN signal low, the on-board processing circuit starts the delayed power-off function, so that the heating function can be started after the sensor is finished working. In this way, the condensed water and water vapor accumulated inside the sensor can be removed by self-heating in the non-working state, which plays a role in preventing freezing.

[0029] The outer wall of the axial cavity of the packaging shell 1 also includes an array of large-diameter slot holes 11 opened in the circumferential direction, and the external medium can enter the axial cavity through the slot holes 11 and the heating filter cylinder 5 in sequence to realize detection thereof.

[0030] The above description is only a description of the preferred embodiment of the utility model, and is not any limitation on the scope of the utility model. Any changes and modifications made by ordinary technicians in the field of the utility model based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A temperature, humidity and pressure sensor that is short-circuit and icing-proof, characterized in that: include: A packaging shell (1) with a snap-on cover (2) glued to the top; A printed circuit board (3) is axially inserted into the axial cavity of the packaging shell (1); A sealing ring (4) is sleeved on the printed circuit board (3), and the outer diameter edge of the sealing ring (4) is in abutment with the inner side wall of the axial cavity of the packaging shell (1) to seal, so as to divide the axial cavity of the packaging shell (1) into an upper cavity and a lower cavity; The heating filter cylinder (5) is made of braided nickel-chromium alloy heating wires and is coaxially inserted into the axial cavity of the packaging shell (1) and abuts against the inner wall of the axial cavity. The heating filter cylinder (5) is located below the sealing ring (4).

2. A temperature, humidity and pressure sensor that is short-circuit and icing-proof as claimed in claim 1, characterized in that: The printed circuit board (3) also includes welded thermistors, humidity chips and pressure chip devices to achieve measurement of temperature, humidity and pressure.

3. A temperature, humidity and pressure sensor that is short-circuit and icing-proof as claimed in claim 1, characterized in that: The sealing ring (4) comprises: a cylinder (41) and a raised ring (42); the raised ring (42) is integrally formed on the circumferential wall of the cylinder (41), and a through slot (43) is provided on the top of the cylinder (41) for plugging and mounting with the printed circuit board (3).

4. A temperature, humidity and pressure sensor that is short-circuit and icing-proof as claimed in claim 3, characterized in that: It also includes a slit groove (44) opened in the radial direction of the sealing ring (4), and the slit groove (44) is perpendicular to the rectangular long side direction of the through slot hole (43) and divides the rectangular long side of the through slot hole (43).

5. A temperature, humidity and pressure sensor that is short-circuit and icing-proof as claimed in claim 4, characterized in that: The two symmetrical side wall ends of the printed circuit board (3) also include U-shaped grooves (6) for matching and embedding with the sealing ring (4).

6. A temperature, humidity and pressure sensor that is short-circuit and icing-proof as claimed in claim 1, characterized in that: It also includes four electrical contacts (31) symmetrically arranged on the printed circuit board (3), wherein the upper and lower two electrical contacts (31) on each side are respectively positive contacts or negative contacts.

7. A temperature, humidity and pressure sensor that is short-circuit and icing-proof as claimed in claim 6, characterized in that: The four electrical contacts (31) are in contact with the inner wall of the heating filter cylinder (5) so as to realize electrical conduction between the heating filter cylinder (5) and the printed circuit board (3).

8. A short-circuit and icing-proof temperature, humidity and pressure sensor according to any one of claims 1 to 7, characterized in that: The outer wall of the axial cavity of the packaging shell (1) further comprises an array of large-diameter slotted holes (11) arranged in a circumferential direction.

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