CN110672258A

CN110672258A - Hydraulic shock resistance and freezing resistance urea solution pressure sensor

Info

Publication number: CN110672258A
Application number: CN201910955029.8A
Authority: CN
Inventors: 王小平; 曹万; 杨军; 洪鹏
Original assignee: Wuhan Finemems Inc
Current assignee: Wuhan Finemems Inc
Priority date: 2019-10-09
Filing date: 2019-10-09
Publication date: 2020-01-10
Anticipated expiration: 2039-10-09
Also published as: CN113218566A; CN110672258B; CN113218566B

Abstract

The invention relates to the technical field of pressure sensors, and discloses a urea solution pressure sensor with hydraulic shock resistance and freezing resistance. Through the cooperation use of protective frame and insulating heat conduction liquid, insulating heat conduction liquid has the effect of insulating heat conduction, the performance of insulating heat conduction liquid heat conduction is greater than urea solution, when low temperature, make the heat that urea solution is close to the one end of pressure chip scatter and disappear very fast, and then make the order that the inside urea solution of pressurized tube freezes from last to down, finally make the direction of expansion of urea solution downwards, change the direction of impact of liquid through spherical surface, the ball pressurized deformation simultaneously, make the pressure chip can not receive highly compressed impact in the twinkling of an eye, when high temperature, the fin gives off the heat of pressure chip fast, reduce the influence of liquid inflation to the pressure chip, the purpose of resistant hydraulic shock has been realized, improve its security, service life has been prolonged.

Description

Hydraulic shock resistance and freezing resistance urea solution pressure sensor

Technical Field

The invention relates to the technical field of pressure sensors, in particular to a urea solution pressure sensor with hydraulic shock resistance and freezing resistance.

Background

Environmental protection is receiving increasing social attention, wherein one of the sources of reducing environmental pollution is to reduce the pollution of automobile exhaust to the atmosphere, the automobile urea solution is crucial to reducing the exhaust emission of vehicles, and the use of the automobile urea solution involves the measurement of the pressure thereof.

The urea solution is used as a measuring medium of the pressure sensor, which is greatly different from a common measuring medium, when the temperature of the urea solution is lower than-11 ℃, the volume of the urea solution can expand by up to 10 percent, when the urea solution is frozen, the urea solution can generate huge pressure to act on a pressure sensitive chip to cause damage to the chip, and when the urea solution is used at high temperature, the volume can expand to influence the accuracy of the pressure sensitive chip, and when the urea solution is serious, the urea solution can damage the interior of the pressure sensitive chip to influence the service life of the pressure sensitive chip, so that the urea solution pressure sensor with hydraulic impact resistance and freezing resistance is provided to solve the problems.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a urea solution pressure sensor with hydraulic shock resistance and freezing resistance, which has the advantages of shock resistance and the like, and solves the problems that the volume change of a urea solution can generate pressure on a pressure chip and influence the accuracy of the pressure sensitive chip, and the internal part of the pressure sensitive chip can be damaged and the service life of the pressure sensitive chip can be influenced when the urea solution is in low-temperature and high-temperature environments in the using process of the existing urea solution pressure sensor.

(II) technical scheme

In order to achieve the purpose of impact resistance, the invention provides the following technical scheme: a urea solution pressure sensor resistant to hydraulic shock and freezing comprises a first sensitive assembly, a second sensitive assembly, an installation assembly and a signal output assembly, wherein the bottom of the installation assembly is fixedly connected with the second sensitive assembly, the first sensitive assembly is fixedly connected with the inside of the installation assembly and the top of the second sensitive assembly, and the signal output assembly is electrically connected with the outside of the first sensitive assembly and the inside of the installation assembly;

the first sensitive assembly comprises a protective frame, a pressure chip and insulating heat-conducting liquid, the pressure chip is connected inside the protective frame, and the insulating heat-conducting liquid is filled in a space between the pressure chip and the protective frame;

the second sensitive assembly comprises a pressure-bearing pipe and a spherical ball, and the spherical ball is filled in the pressure-bearing pipe.

Preferably, the first sensitive assembly further comprises a circuit connecting block and an isolation sleeve, the circuit connecting block is electrically connected to the left side of the pressure chip, and the isolation sleeve is connected to the bottom of the pressure chip.

Preferably, the protection frame is a rectangular plastic frame with a hollow interior, and the bottom of the pressure chip penetrates through the protection frame and extends to the interior of the pressure-receiving pipe.

Preferably, the isolation sleeve is a cylindrical elastic isolation sleeve which is hollow inside and has a missing top.

Preferably, the second sensing assembly further comprises a sealing member connected to the outside of the pressure pipe.

Preferably, the urea solution is filled in the pressure-receiving pipe, a circular groove is formed in the outer side of the pressure-receiving pipe, and the circular groove is used for installing a sealing element.

Preferably, the number of the round balls is not less than two, the round balls are elastic round balls with a reducible volume after being pressed, and the diameter of the round balls is larger than that of the lower end inside the pressed pipe.

Preferably, the mounting assembly comprises a mounting block and a heat dissipation block, and the heat dissipation block is connected to the top of the mounting block.

Preferably, the radiating block is made of metal copper, and the radiating block consists of a round block and a plurality of radiating fins which are uniformly distributed on the top of the round block.

Preferably, the signal output assembly comprises a circuit board and a signal wire, and the signal wire is electrically connected with the first sensitive assembly through the circuit board.

(III) advantageous effects

Compared with the prior art, the invention provides a urea solution pressure sensor with hydraulic shock resistance and freezing resistance, which has the following beneficial effects:

1. the urea solution pressure sensor with hydraulic impact resistance and freezing resistance is characterized in that the protective frame is used in cooperation with insulating heat-conducting liquid, the protective frame protects the pressure chip, a placing space is provided for the insulating heat-conducting liquid, the insulating heat-conducting liquid has an insulating heat-conducting effect, the radiating block is made of copper and has good heat-conducting performance, the radiating area is increased by the plurality of radiating fins in the radiating block, the heat-conducting performance of the insulating heat-conducting liquid is greater than that of the urea solution, at low temperature, the heat of one end, close to the pressure chip, of the urea solution is quickly dissipated, the temperature is low, the urea solution is frozen firstly, the urea solution is frozen sequentially from top to bottom, the expansion direction of the urea solution is downward, the pressure volume of the ball is reduced, the pressure of the urea solution can be absorbed, and the pressure chip is prevented from being subjected to the pressure of the expansion of the urea solution, when high temperature, the fin gives off pressure chip's heat fast, with higher speed the balance of inside and outside temperature, reduces the influence of liquid inflation to pressure chip to when highly compressed urea solution lets in the pressurized tube inside in the twinkling of an eye, through the impact direction of spherical face change liquid, the ball pressurized deformation simultaneously makes pressure chip can not receive highly compressed impact in the twinkling of an eye, avoids receiving the harm, has realized the purpose of resistant hydraulic shock, improves its security, has prolonged life.

2. This resistant hydraulic shock and anti frozen urea solution pressure sensor, through the use of ball, utilize the ball to receive the pressure volume to diminish characteristics, under the low temperature condition, when the inside urea solution of pressurized tube freezes the volume increase, ball pressurized volume diminishes, for its space that provides the packing of the urea solution that freezes, makes the ball absorb its volume change, makes the pressure chip can not receive the huge pressure that the urea solution that freezes produced, avoids receiving the harm, has realized anti frozen purpose.

Drawings

FIG. 1 is a cross-sectional view of an overall urea solution pressure sensor of the present invention that is resistant to hydraulic shock and freezing;

fig. 2 is a schematic structural diagram of a first sensing assembly according to the present invention.

In the figure: the device comprises a mounting block 1, a heat dissipation block 2, a first sensitive assembly 3, a protective frame 301, a pressure chip 302, a circuit connection block 303, a 304 isolation sleeve, an insulating heat-conducting liquid 305, a signal line 4, a circuit board 5, a pressure-receiving pipe 6, a circular groove 7, a sealing element 8 and a circular ball 9.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1-2, a urea solution pressure sensor with hydraulic shock resistance and freezing resistance comprises a first sensitive component 3, a second sensitive component, a mounting component and a signal output component, wherein the bottom of the mounting component is fixedly connected with the second sensitive component, the first sensitive component 3 is fixedly connected inside the mounting component and positioned at the top of the second sensitive component, and the signal output component is electrically connected outside the first sensitive component 3 and positioned inside the mounting component.

The top fixedly connected with radiating block 2 of installing block 1, radiating block 2 comprises circle piece and a plurality of fin, and fin evenly distributed increases its heat radiating area at the top of circle piece, and radiating block 2 is made for metal copper, has good heat conductivility, for the installation component.

At the interior diapire fixedly connected with protective frame 301 of installation piece 1, protective frame 301 is inside cavity and the rectangle plastic frame of top disappearance, protective frame 301's inside fixedly connected with pressure chip 302, the bottom of pressure chip 302 runs through and extends to protective frame 301's bottom, the bottom fixedly connected with spacer 304 of pressure chip 302, spacer 304 is the elastic spacer, can produce elastic deformation, it receives the influence of pressure to reduce pressure chip 302, the size of spacer 304 inner space and the size looks adaptation of pressure chip 302, the inside electrical connection that the left side of pressure chip 302 just is located protective frame 301 has circuit connecting block 303, the outside of circuit connecting block 303 and pressure chip 302 and the inside that is located protective frame 301 are filled with insulating heat conduction liquid 305, the heat conductivility of insulating heat conduction liquid 305 is greater than the urea solution, be first sensitive subassembly 3.

The left side of protective frame 301 just is located the interior diapire electrical connection of installing piece 1 and has circuit board 5, the right side and the circuit connection piece 303 electrical connection of circuit board 5, the left side electrical connection of circuit board 5 has signal line 4, and the one end that circuit board 5 was kept away from to signal line 4 runs through and extends to the outside of installing piece 1, is the signal output subassembly.

The bottom of installation piece 1 and the outside fixedly connected with pressurized pipe 6 that is located spacer sleeve 304, circular slot 7 has been seted up in the outside of pressurized pipe 6, the internal connection of circular slot 7 has sealing member 8, the inside packing of pressurized pipe 6 has urea solution, and be provided with a plurality of ball 9 in the urea solution, the diameter of ball 9 is greater than the diameter of the inside low side of pressurized pipe 6, prevent it and drop, ball 9 is the elasticity ball that the volume can reduce after the pressurized, can absorb the volume change after freezing, for the sensitive subassembly of second.

When in use:

(1) at low temperature, the heat dissipation area is increased by the plurality of heat dissipation fins in the heat dissipation block, and the heat conduction performance of the insulating heat conduction liquid 305 is greater than that of the urea solution, so that the heat of the pressure chip 302 is dissipated rapidly by the insulating heat conduction liquid 305, the temperature of one end, close to the pressure chip 302, of the urea solution is relatively low, the urea solution close to the pressure chip 302 is frozen first, the freezing sequence of the urea solution in the pressure pipe 6 is from top to bottom, the expansion direction of the urea solution is downward finally, the pressure on the inner wall of the pressure pipe 6 is enabled to be applied, the pressure chip 302 is prevented from being applied by the pressure of the urea solution, and at high temperature, the heat of the pressure chip 302 is dissipated rapidly by the heat dissipation fins, so that the temperature of the urea solution is consistent with the temperature of the pressure chip 302 finally, the balance of the internal and external temperatures is accelerated.

(2) In the frozen in-process of urea solution, through the use of ball 9, utilize ball 9 to receive the characteristics that the pressure volume diminishes, when the frozen volume of the inside urea solution of pressurized tube 6 increased, ball 9 compressed diminishes, provides the space of placing for the volume of urea solution increase to will absorb its volume change, can not avoid it to receive the harm to the inner wall of pressurized tube 6 and pressure chip 302 production pressure.

In summary, by using the heat dissipation block 2, the insulating heat-conducting liquid 305 and the ball 9 in combination, the freezing sequence of the urea solution inside the pressure-receiving pipe 6 is changed by the heat dissipation effect of the heat dissipation block 2 and the insulating heat-conducting liquid 305, the pressure of the urea solution is transferred to the inner wall of the pressure-receiving pipe 6, so that the pressure chip 302 is resistant to the impact of hydraulic pressure, and when the instantly high-pressure urea solution is introduced into the pressure-receiving pipe 6, the impact direction of the liquid is changed by the spherical surface of the ball 9, and the ball 9 deforms under pressure, so that the pressure chip is not impacted by the instantly high pressure, and the pressed volume of the ball 9 is reduced, so as to absorb the volume change after freezing, avoid the pressure chip 302 from being extruded, achieve the purposes of hydraulic impact resistance and freezing resistance, and solve the problem that the volume change of the urea solution can generate pressure on the pressure chip 302 in the low-temperature and high-temperature, the accuracy of the pressure sensitive chip is influenced, and the interior of the pressure sensitive chip can be damaged in serious conditions, so that the service life of the pressure sensitive chip is influenced.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A urea solution pressure sensor resistant to hydraulic shock and freezing is characterized in that: the sensor comprises a first sensitive component (3), a second sensitive component, a mounting component and a signal output component, wherein the bottom of the mounting component is fixedly connected with the second sensitive component, the first sensitive component (3) is fixedly connected with the inside of the mounting component and positioned at the top of the second sensitive component, and the signal output component is electrically connected with the outside of the first sensitive component (3) and positioned inside the mounting component;

the first sensitive assembly (3) comprises a protective frame (301), a pressure chip (302) and an insulating heat-conducting liquid (305), wherein the pressure chip (302) is connected inside the protective frame (301), and the insulating heat-conducting liquid (305) is filled in a space between the pressure chip (302) and the protective frame (301);

the second sensitive assembly comprises a pressure-bearing pipe (6) and a round ball (9), and the round ball (9) is filled in the pressure-bearing pipe (6).

2. The hydraulic shock and freezing resistant urea solution pressure sensor of claim 1, wherein: the first sensitive assembly (3) further comprises a circuit connecting block (303) and an isolation sleeve (304), wherein the circuit connecting block (303) is electrically connected to the left side of the pressure chip (302), and the isolation sleeve (304) is connected to the bottom of the pressure chip (302).

3. A hydraulic shock and freezing resistant urea solution pressure sensor according to claim 1 or 2, wherein: the protection frame (301) is a rectangular plastic frame with a hollow interior, and the bottom of the pressure chip (302) penetrates through the protection frame (301) and extends to the interior of the pressure-receiving pipe (6).

4. The hydraulic shock and freezing resistant urea solution pressure sensor of claim 2, wherein: the isolation sleeve (304) is a cylindrical elastic isolation sleeve which is hollow inside and has a missing top.

5. The hydraulic shock and freezing resistant urea solution pressure sensor of claim 1, wherein: the second sensitive assembly further comprises a sealing member (8), and the sealing member (8) is connected to the outer side of the pressure receiving pipe (6).

6. A hydraulic shock and freezing resistant urea solution pressure sensor according to claim 1 or 5, wherein: the urea solution is filled in the pressure receiving pipe (6), a circular groove (7) is formed in the outer side of the pressure receiving pipe (6), and the circular groove (7) is used for installing a sealing element (8).

7. The hydraulic shock and freezing resistant urea solution pressure sensor of claim 1, wherein: the number of the round balls (9) is not less than two, the round balls (9) are elastic round balls with a reducible volume after being pressed, and the diameter of the round balls (9) is larger than that of the lower end inside the pressure-bearing pipe (6).

8. The hydraulic shock and freezing resistant urea solution pressure sensor of claim 1, wherein: the mounting assembly comprises a mounting block (1) and a heat dissipation block (2), and the top of the mounting block (1) is connected with the heat dissipation block (2).

9. The hydraulic shock and freezing resistant urea solution pressure sensor of claim 8, wherein: the radiating block (2) is made of metal copper, the radiating block (2) is composed of a round block and a plurality of radiating fins, and the radiating fins are evenly distributed on the top of the round block.

10. The hydraulic shock and freezing resistant urea solution pressure sensor of claim 1, wherein: the signal output assembly comprises a circuit board (5) and a signal wire (4), and the signal wire (4) is electrically connected with the first sensitive assembly (3) through the circuit board (5).