CN212585900U

CN212585900U - Crankcase pressure sensor

Info

Publication number: CN212585900U
Application number: CN202021237665.1U
Authority: CN
Inventors: 王小平; 曹万; 杨军
Original assignee: Wuhan Finemems Inc
Current assignee: Wuhan Finemems Inc
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2021-02-23
Anticipated expiration: 2030-06-29

Abstract

A crankcase pressure sensor relates to a pressure sensor, which comprises a main body shell, a sensing element and an insert shell fixed with the main body shell, wherein the main body shell is provided with a cavity and an air inlet is arranged on the main body shell; the sensing element is arranged in the cavity and senses the pressure in the crankcase through the air inlet; a contact pin is plastically packaged in the plug-in shell, one end of the contact pin is fixedly connected with the sensing element, and the other end of the contact pin can be plugged with other electronic devices to transmit pressure data of the sensing element; the plug-in shell is also internally provided with a vent hole communicated with the cavity, and the cavity is communicated with the external atmosphere through the vent hole; through the position of this change air vent, avoid the exposure of air vent with the air vent setting in plug-in components casing to the invasion and the malicious destruction of some personnel of a large amount of dusts are effectively avoided.

Description

Crankcase pressure sensor

Technical Field

The utility model relates to pressure sensor specifically is a crankcase pressure sensor.

Background

The pressure range of the crankcase pressure sensor is usually very small, so the selected sensing element is very special and sensitive to temperature, stress and the like. At present, a pressure chip used by a sensing element is a gauge pressure type pressure chip and is used for sensing the pressure in a crankcase and comparing the pressure with an atmospheric pressure value, so that a vent hole needs to be arranged in a shell to ensure that the pressure chip is unblocked with the atmosphere.

The existing vent hole is usually arranged on the shell directly and exposed outside, and the arrangement causes dust to fall onto the pressure chip directly through the vent hole; moreover, if the waterproof vent hole is attached to the orifice of the vent hole, dust directly covers the waterproof breathable film, so that the performance of the waterproof breathable film is affected; moreover, because the vent hole is exposed, part of people can easily puncture the waterproof breathable film through the vent hole, and even directly damage the sensing element, thereby causing loss to users.

SUMMERY OF THE UTILITY MODEL

To the problem, the utility model designs a pressure sensor of new construction when not influencing pressure chip and atmospheric pressure intercommunication, can also hide the air vent.

The utility model provides a technical scheme as follows:

a crankcase pressure sensor comprises a main body shell, a sensing element and a plug-in shell fixed with the main body shell, wherein the main body shell is provided with a cavity and an air inlet hole is formed in the main body shell;

the sensing element is arranged in the cavity and senses the pressure in the crankcase through the air inlet;

a contact pin is plastically packaged in the plug-in shell, one end of the contact pin is fixedly connected with the sensing element, and the other end of the contact pin can be plugged with other electronic devices to transmit pressure data of the sensing element;

and the plug-in shell is also internally provided with a vent hole communicated with the cavity, and the cavity is communicated with the external atmosphere through the vent hole.

Furthermore, a waterproof breathable film is attached to the port, connected with the vent hole, of the cavity.

Further, the main body shell comprises an upper cover and a lower shell with a cavity, the upper cover is provided with a first matching part, the lower shell is provided with a second matching part, and the first matching part is matched with the second matching part to fix the upper cover and the lower shell; the upper cover seals the cavity to form the cavity.

Further, the first matching part is a bent flange of the outer peripheral wall of the upper cover; the second matching part is a groove formed in the lower shell, and the bent flanging is inserted into the groove to fix the upper cover and the lower shell.

Furthermore, the sensing element comprises a PCB, a pressure chip and a sealing gasket with a through hole, wherein the pressure chip is attached to the PCB; the sealing gasket is arranged between the pressure chip and the air inlet and is attached to the bottom of the cavity; the pressure chip is provided with an induction hole, and the induction hole, the through hole and the air inlet are communicated to form an air inlet channel.

Further, the air inlet hole comprises a first air inlet part and a second air inlet part;

the first air inlet part is of a straight-through structure, and one end of the first air inlet part is connected with the crankcase;

the second air inlet part is of a circular truncated cone structure with an upper orifice and a lower orifice, the upper orifice is communicated with the cavity and is opposite to the through hole, and the lower orifice is communicated with the other end of the first air inlet part.

Further, the diameter of the upper orifice of the second air inlet part is smaller than that of the through hole.

The beneficial effect that adopts this technical scheme to reach does:

through the position of the variable vent hole, the vent hole is arranged in the plug-in shell to avoid the exposure of the vent hole; because the plug-in components casing can be pegged graft with other outside electronic device when using, consequently, the air vent not only can effectually avoid the invasion of a large amount of dusts in the plug-in components casing, can also avoid some personnel's malicious destruction to realize the powerful protection to the sensor.

Drawings

Fig. 1 is an exploded view of a pressure sensor.

Fig. 2 is a perspective view of the entire structure of the pressure sensor.

Fig. 3 is a sectional view taken along line a-a in fig. 2.

Wherein: 10 main part casing, 11 upper cover, 12 lower casing, 20 sensing element, 21 PCB board, 22 pressure chip, 23 sealed pad, 30 plug-in components casing, 31 contact pin, 32 air vent, 33 waterproof ventilated membrane, 40 inlet port, 41 first air inlet portion, 42 second air inlet portion, 100 cavity, 211 jack.

Detailed Description

The principles and features of the present invention are described below in conjunction with the following drawings, the examples given are only intended to illustrate the present invention and are not intended to limit the scope of the present invention.

The present embodiment proposes a new structure of pressure sensor, see fig. 1-3, which is used for sensing the pressure in the crankcase, and includes a main body housing 10, a cavity 100 is provided in the main body housing 10, and the cavity 100 is used for accommodating a sensing element 20; an air inlet hole 40 is arranged in the main body shell 10, the air inlet hole 40 is connected with a crankcase (not shown), so that the sensing element 20 can sense the pressure change in the crankcase in real time through the air inlet hole 40, and the data information acquired by the sensing element 20 is transmitted to an external electronic device through the plug pin 31.

The pin 31 is used in a conventional manner, and optionally, in a specific use, the data transmission may also be implemented by implementing communication with an external electronic device through a wire, but in this embodiment, the pin 31 is preferably used to ensure stable data transmission.

The contact pin 31 is sealed in a plug-in shell 30 through an injection molding process, the plug-in shell 30 is fixed with the main body shell 10, and the plug-in shell 30 is used for being in plug-in fit with an external electronic device to realize data transmission; specifically, one end of the pin 31 is fixedly connected to the sensing element 20, and after the plug-in housing 30 is plugged into an external electronic device, the other end of the pin 31 is simultaneously inserted into the external electronic device, so that under the sealing protection of the plug-in housing 30, the data transmission of the pin 31 is more stable, and the service life is also prolonged.

In this embodiment, a vent hole 32 is further provided in the insert housing 30, and the vent hole 32 communicates with the cavity 100 in the main body housing 10, because the sensing element 20 is provided in the cavity 100, so that the sensing element 20 communicates with the atmospheric pressure.

By arranging the vent hole 32 in the plug-in housing 30, the vent hole 32 is prevented from being exposed, and particularly when the plug-in housing 30 is plugged with an external electronic device, the plug-in housing is equivalent to form a whole, so that the possibility that external dust enters the cavity 100 through the vent hole 32 can be effectively isolated; and the vent 32 is concealed within the insert housing 30, the likelihood of damage to the sensing element 20 through the vent 32 will be further reduced as compared to an exposed vent 32.

In this embodiment, in order to avoid the intrusion of water vapor in the atmosphere and thus affect the precision of the sensing element 20, a waterproof breathable film 33 is attached to the port of the cavity 100 connected to the vent 32, and the waterproof breathable film 33 is used to realize effective filtration of water vapor.

In this embodiment, the main body housing 10 is a split structure, that is, the main body housing 10 includes an upper cover 11 and a lower housing 12 having a cavity, the upper cover 11 has a first mating portion, the lower housing 12 has a second mating portion, and the first mating portion and the second mating portion are mated to fix the upper cover 11 and the lower housing 12; the cavity is sealed by the upper cover 11 to form the cavity 100, and a split structure is adopted, so that the installation and glue injection of the sensing element 20 are conveniently realized.

Specifically, the first matching part is a bent flange on the outer peripheral wall of the upper cover 11, and the bent flange is bent downwards to form a flange; the second matching part is a groove formed in the lower shell 12, and the bent flanging is inserted into the groove to fix the upper cover 11 and the lower shell 12.

The sensing element 20 includes a PCB 21, a pressure chip 22 having an induction hole, and a sealing pad 23 having a through hole, wherein the pressure chip 22 is attached to the PCB 21; the PCB 21 is provided with a jack 211, and the pin 31 is fixed on the PCB 21 through the jack 211; the sealing gasket 23 is arranged between the pressure chip 22 and the air inlet hole 40; specifically, a limiting groove is formed at the bottom of the cavity 100, and in the assembling process, the sealing gasket 23 is firstly adhered in the limiting groove; then the pressure chip 22 is attached to the PCB 21 by SMT, and then the PCB 21 is fixed to the fixing post in the cavity 100, so that the sealing gasket 23 is deformed by the pressure chip 22 to meet the sealing requirement; at this time, the sensing hole, the through hole and the air inlet are communicated to form an air inlet channel, and the pressure chip 22 can monitor the gas pressure in the crankcase in real time through the air inlet channel.

It should be noted that the gasket 23 should be bonded to the limiting groove by using silicone gel, and the sealing function of the gasket 23 can be effectively achieved by using silicone gel, so that the gas passing through the gas inlet hole 40 can only enter the sensing hole of the pressure chip 22 from the through hole, and the occurrence of gas leakage around the gasket 23 is avoided.

In this embodiment, the intake holes 40 include a first intake portion 41 and a second intake portion 42, and the aperture of the first intake portion 41 is larger than that of the second intake portion 42, because the first intake portion 41 is directly communicated with the crankcase, and the second intake portion 42 needs to be connected with the through hole of the gasket 23, so that the first intake portion 41 and the second intake portion 42 with two different apertures are reasonably designed.

The first air inlet 41 is a through structure, one end of the first air inlet 41 is connected to the crankcase, the second air inlet 42 is a circular truncated cone structure having an upper orifice and a lower orifice, the upper orifice is communicated with the cavity 100 and faces the through hole of the sealing gasket 23, and the lower orifice is communicated with the other end of the first air inlet 41.

It should be noted that, here, the second air inlet portion 42 is provided as a circular truncated cone structure to reduce the influence of the condensed water on the pressure chip 22.

Because the pressure of the crankcase is different from the pressure of the external atmospheric pressure, condensed water may be generated at the position where the sensor is connected, and if a straight-through structure is directly adopted, part of the condensed water is found to be directly gathered near the pressure chip 22 in a specific use, so that the influence is generated on the pressure chip 22; therefore, the circular truncated cone is arranged through the second air inlet portion 42, most of the condensed water is directly collected on the inner annular wall of the circular truncated cone, and the influence of the condensed water on the pressure chip 22 is reduced.

In this embodiment, the diameter of the upper opening of the second air inlet 42 is smaller than the diameter of the through hole of the gasket 23, so as to further reduce the possibility of condensed water collecting on the pressure chip 22.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A crankcase pressure sensor comprising a main body housing (10), a sensing element (20) and a plug-in housing (30) fixed to the main body housing (10),

the main body shell (10) is provided with a cavity (100) and the main body shell (10) is provided with an air inlet (40);

the sensing element (20) is arranged in the cavity (100) and senses the pressure in the crankcase through the air inlet hole (40);

a contact pin (31) is plastically packaged in the plug-in shell (30), one end of the contact pin (31) is fixedly connected with the sensing element (20), and the other end of the contact pin (31) can be plugged with other electronic devices to transmit pressure data of the sensing element (20);

the plug-in shell (30) is also internally provided with a vent hole (32) communicated with the cavity (100), and the cavity (100) is communicated with the external atmosphere through the vent hole (32).

2. A crankcase pressure sensor according to claim 1, wherein a waterproof and gas permeable membrane (33) is attached to the port of the cavity (100) connected to the vent hole (32).

3. A crankcase pressure sensor according to claim 1, wherein the main body housing (10) comprises an upper cover (11) and a lower housing (12) having a cavity, the upper cover (11) having a first mating portion, the lower housing (12) having a second mating portion, the first mating portion and the second mating portion cooperating to secure the upper cover (11) to the lower housing (12); the upper cover (11) seals the cavity to form the cavity (100).

4. A crankcase pressure sensor according to claim 3, characterized in that the first mating portion is a bent down flange of the outer peripheral wall of the upper cover (11); the second matching part is a groove formed in the lower shell (12), and the lower bending flanging is inserted into the groove to fix the upper cover (11) and the lower shell (12).

5. A crankcase pressure sensor according to claim 1, wherein the sensing element (20) comprises a PCB (21), a pressure chip (22) and a sealing gasket (23) with a through hole, the pressure chip (22) is attached to the PCB (21); the sealing gasket (23) is arranged between the pressure chip (22) and the air inlet hole (40), and the sealing gasket (23) is attached to the bottom of the cavity (100); the pressure chip (22) is provided with an induction hole, and the induction hole, the through hole and the air inlet hole (40) are communicated to form an air inlet channel.

6. A crankcase pressure sensor according to claim 5, wherein the air inlet hole (40) comprises a first air inlet portion (41) and a second air inlet portion (42);

the first air inlet part (41) is of a straight-through structure, and one end of the first air inlet part (41) is connected with the crankcase;

the second air inlet portion (42) is of a circular truncated cone structure with an upper orifice and a lower orifice, the upper orifice is communicated with the cavity (100) and is opposite to the through hole, and the lower orifice is communicated with the other end of the first air inlet portion (41).

7. A crankcase pressure sensor according to claim 6, wherein the diameter of the upper aperture of the second inlet portion (42) is smaller than the diameter of the through hole.