KR20160121236A - Gas sensor - Google Patents

Gas sensor Download PDF

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Publication number
KR20160121236A
KR20160121236A KR1020150050965A KR20150050965A KR20160121236A KR 20160121236 A KR20160121236 A KR 20160121236A KR 1020150050965 A KR1020150050965 A KR 1020150050965A KR 20150050965 A KR20150050965 A KR 20150050965A KR 20160121236 A KR20160121236 A KR 20160121236A
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KR
South Korea
Prior art keywords
sensor element
sensor
circumferential surface
gas
mounting portion
Prior art date
Application number
KR1020150050965A
Other languages
Korean (ko)
Inventor
이대건
고양주
김정택
박헌준
정윤기
조성은
Original Assignee
주식회사 현대케피코
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Application filed by 주식회사 현대케피코 filed Critical 주식회사 현대케피코
Priority to KR1020150050965A priority Critical patent/KR20160121236A/en
Publication of KR20160121236A publication Critical patent/KR20160121236A/en

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/403—Cells and electrode assemblies
    • G01N27/406—Cells and probes with solid electrolytes
    • G01N27/407—Cells and probes with solid electrolytes for investigating or analysing gases
    • G01N27/4077—Means for protecting the electrolyte or the electrodes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02D—CONTROLLING COMBUSTION ENGINES
    • F02D41/00—Electrical control of supply of combustible mixture or its constituents
    • F02D41/02—Circuit arrangements for generating control signals
    • F02D41/14—Introducing closed-loop corrections
    • F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/403—Cells and electrode assemblies
    • G01N27/406—Cells and probes with solid electrolytes
    • G01N27/407—Cells and probes with solid electrolytes for investigating or analysing gases
    • G01N27/4073—Composition or fabrication of the solid electrolyte
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/403—Cells and electrode assemblies
    • G01N27/406—Cells and probes with solid electrolytes
    • G01N27/407—Cells and probes with solid electrolytes for investigating or analysing gases
    • G01N27/4075—Composition or fabrication of the electrodes and coatings thereon, e.g. catalysts
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/403—Cells and electrode assemblies
    • G01N27/406—Cells and probes with solid electrolytes
    • G01N27/407—Cells and probes with solid electrolytes for investigating or analysing gases
    • G01N27/4078—Means for sealing the sensor element in a housing

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  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Biochemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Electrochemistry (AREA)
  • Physics & Mathematics (AREA)
  • Analytical Chemistry (AREA)
  • Molecular Biology (AREA)
  • General Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Engineering & Computer Science (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Measuring Oxygen Concentration In Cells (AREA)

Abstract

The present invention relates to a gas sensor, more particularly, to a gas sensor for detecting a gas, wherein the gas sensor includes a sensor element located inside the sensor housing, a sealing member formed on an outer circumferential surface of the sensor element, And an insulating bushing disposed at both ends of the sensor element and formed on an outer circumferential surface of the sensor element, wherein a space portion having a predetermined gap with the sensor element is formed at one end of the insulating bushing to prevent heat loss Thereby improving the initial driving performance of the sensor element.

Description

Gas sensor {GAS SENSOR}

The present invention relates to a gas sensor, and more particularly, to a gas sensor that can accurately and stably measure the concentration of a gas in an exhaust gas of an automobile by preventing deterioration in initial driving performance of a gas sensor used in an automobile or the like.

Generally, a vehicle mounts a gas sensor to operate the engine at an optimum air-fuel ratio. The gas sensor measures the concentration of the gas contained in the exhaust gas and transmits the result to the ECU.

The ECU feeds back the signal of the gas sensor and uses it as a basic signal for ignition timing and fuel injection amount correction.

That is, the gas sensor is installed in an exhaust line of a vehicle, etc., to determine the air-fuel ratio of the exhaust gas and transmit it to the ECU to correct the amount of air or fuel supplied to the engine. Thereby maintaining the optimum air-fuel ratio.

One of the key components of such a gas sensor is a sensor element. Generally, one side of the sensor element is formed with a contact surface contacting the exhaust gas, and the other side is formed with an electrode surface in contact with the atmospheric gas.

A gas sensor terminal is connected to the electrode surface to transmit the electromotive force generated in the sensor element to the ECU according to the air-fuel ratio of the gas passing through the exhaust line of the vehicle.

The gas sensor terminal is preferably made of a conductive material such as stainless steel (SUS) so as to transmit the electromotive force to the ECU, and is preferably made elastic like a leaf spring, and the sensor element is made of a ceramic material such as zirconia. The gas sensor terminal is grounded on the electrode surface of the sensor element to transmit a voltage generated in the sensor element to the ECU.

FIG. 1 is a cross-sectional view of a general gas sensor, and FIG. 2 is an enlarged cross-sectional view of the insulating bush of FIG. Some known configurations that are independent of the technical features of the present invention are omitted.

The sensor element 20 is located inside the sensor housing 10 and a sealing member 30 for fixing the sensor element 20 in the sensor housing 10 is formed on the outer circumferential surface of the sensor element 20, And an insulating bush 40 disposed at both ends of the sealing member 30 are positioned.

The sensor element 20 is fixed to the receiving space of the sensor housing 10 through the sealing member 30 and the insulating bushing 40. The sensor housing 10 is fixed to the sensor element 10 by poisoning, 20 can be protected.

Generally, in order for the sensor element 20 to be driven normally, the element must be heated to a certain temperature or higher. For this purpose, the sensor element 20 is heated while being driven by the exhaust gas. However, The heater is located inside the device.

However, the insulation bushing 40 of the general gas sensor is in contact with the sensor element 20 on most of its surfaces due to the constant width of the inner circumferential surface. Accordingly, the heater voltage is applied to the sensor element 20 at the initial start- When the heater 20 is heated, the insulating bush 40 absorbs a part of the heat from the sensor element 20, thereby generating heat loss. As a result, the initial driving performance of the gas sensor is deteriorated.

Korea Patent Publication No. 2009-0083833 " Waterproof structure of oxygen sensor for vehicle " (disclosed on Aug. 04, 2009)

An object of the present invention is to provide a sensor element which has an insulating bush formed on an outer circumferential surface of a sensor element and has a space portion spaced apart from the sensor element by a predetermined gap to prevent heat loss generated when the sensor element is heated, And an object of the present invention is to provide a gas sensor having an improved gas sensor.

According to an aspect of the present invention, there is provided a gas sensor for detecting a gas, the gas sensor comprising: a sensor element located in a sensor housing; a seal formed on an outer circumferential surface of the sensor element; And an insulating bush disposed at both ends of the sealing member and formed on an outer circumferential surface of the sensor element, wherein a space portion having a predetermined gap with the sensor element is formed at one end of the insulating bush.

The insulating bushing according to an embodiment of the present invention includes a mounting portion for contacting the sensor element and fixing the sensor element, and a pressing portion extending from one side of the mounting portion and contacting and pressing the sealing member, And the space portion is extended on the other side of the mounting portion.

According to an embodiment of the present invention, the width of the inner circumferential surface of the mounting portion is 0.1 to 0.3 mm larger than the thickness of the sensor element mounted on the mounting portion.

The insulating bush according to an embodiment of the present invention is characterized in that the inner circumferential surface width of the space portion is larger than the inner circumferential surface width of the mounting portion.

According to an embodiment of the present invention, the inner circumferential surface width of the space portion is 0.5 to 1 mm larger than the inner circumferential surface width of the mounting portion.

Further, in the insulated bush according to the embodiment of the present invention, the height of the mounting portion is larger than the height of the space portion.

The gas sensor of the present invention can minimize the heat loss of the sensor element when the cold element is heated by using an insulation bushing structure that is relatively simple to manufacture.

In addition, the gas sensor of the present invention is advantageous in that the initial driving performance of the gas sensor is very excellent because the heat loss of the sensor element is minimized at the time of initial startup.

1 is a cross-sectional view of a general gas sensor.
Fig. 2 is an enlarged cross-sectional view of the insulating bush of Fig. 1. Fig.
3 is a cross-sectional view of an oxygen sensor having an insulated bush according to an embodiment of the present invention.
4 is an enlarged cross-sectional view of the insulating bush of Fig.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to facilitate a person skilled in the art to easily carry out the technical idea of the present invention. . In the drawings, the same reference numerals are used to designate the same or similar components throughout the drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The gas sensor is a generic term of a sensor for detecting a gas. Examples of the gas sensor include an oxygen (O 2 ) sensor, a knox (NO x ) sensor, etc. In the following embodiments, the oxygen sensor is used as a reference. Therefore, it is apparent that the oxygen sensor described below can be replaced by another gas sensor.

FIG. 3 is a cross-sectional view of an oxygen sensor having an insulating bush according to an embodiment of the present invention, and FIG. 4 is an enlarged cross-sectional view of the insulating bush of FIG.

As shown in the figure, an oxygen sensor for detecting a gas according to an embodiment of the present invention includes a sensor element 20, and a conductive electrode surface is formed at one end of the sensor element 20, The signal can be transmitted and received, and it is grounded with a metallic oxygen sensor terminal. The other end of the sensor element 20 is provided to be in contact with the exhaust gas, and various components may be additionally mounted.

The sensor element 20 is not limited in shape but is shouted inside a cylindrical sensor housing 10 and a sealing member 30 and an insulating bush 40 are formed on the outer circumferential surface of the sensor element 20 . The sealing member 30 fixes the sensor element 20 in the sensor housing 10 and has an accommodation space opened to both sides of the sensor housing 10 so that the sensor element 20 20 are disposed.

The sensor element 20 can be formed by molding a material such as zirconia into a bar shape and can form an electrode surface where one side forms a contact surface in contact with the exhaust gas and the other side is in contact with oxygen in the atmosphere, The electrode surface may be coated with platinum to form a (-) electrode or (+) electrode.

The sensor element 20 generates a low voltage when the oxygen concentration in the exhaust gas is high according to the difference between the oxygen concentration in the exhaust gas and the oxygen concentration in the atmosphere, and generates a high voltage when the oxygen concentration in the exhaust gas is low. Is transmitted to the electronic control system (ECU), and the electronic control system performs feedback on the engine air-fuel ratio control in view of this.

The sensor element 20 is fixed to the inside of the sensor housing 10 via the insulating bush 40 and the sealing member 30 and the sensor housing 10 is fixed to the sensor housing 20 by poisoning and thermal shock, Can be protected.

The sealing member 30 is formed on the outer circumferential surface of the sensor element 20 and performs a function of enhancing a sealing effect so that fuel debris or the like flowing through the exhaust gas does not flow into the inside. There is no limitation on the shape of the sealing member 30 but it is preferable that the inner surface shape of the sealing member 30 corresponds to the outer surface shape of the sensor element 20 and the outer surface shape corresponds to the inner surface shape of the sensor housing 10 Do. In order to maximize the sealing effect of the sealing member 30, a raw material including glass and talc can be formed by compression molding.

The insulating bush 40 may be formed on the outer circumferential surface of the sensor element 20 and may be disposed at both ends of the sealing member 30. The insulating bush 40 may be made of a ceramic material such as a soapstone, but is not limited thereto.

The insulating bushing 40 may be mounted on the outer circumferential surface of the sensor element 20 so as to be disposed at both ends of the sealing member 30 and composed of an upper insulating bush 41 and a lower insulating bushing 42, The insulating bushing 41 and the lower insulating bush 42 serve as an insulator and may be used to fix the sensor element 20 together with the sealing member 30 in the sensor housing 10.

The sealing member 30 and the upper and lower insulating bushes 41 and 42 are formed in the housing space of the sensor housing 10 so as to block the inflow of the exhaust gas into the space where the electrode surface of the sensor element 20 is located. Up and down.

A space 40a may be formed at one end of the insulating bush 40 according to an embodiment of the present invention so as to be spaced apart from the sensor element 20 by a predetermined gap. The insulating bush 40 according to the embodiment of the present invention is different from the conventional case in which the insulating bush 40 of the conventional gas sensor 100 contacts the sensor element 20 on most surfaces to generate heat loss The space portion 40a is formed at one end, and heat loss due to contact or conduction can be minimized.

The insulating bushing 40 preferably includes a mounting portion 40b for contacting the sensor element 20 to fix the sensor element 20 and a sealing member 30b extending from one side of the mounting portion 40b, And the pressing portion 40c is in contact with the pressing portion 40c. The space portion 40a can be extended to the other side of the mounting portion 40b.

The mounting portion 40b corresponds to a portion where heat loss due to conduction occurs in contact with or in proximity to the sensor element 20 and functions to securely mount the sensor element 20. The pressing portion 40c The sealing member 30 may be formed in a shape suitable for crushing the raw material so that the sealing member 30 can be manufactured by press-molding the raw material of the sealing member 30. The sealing member 30 may be in contact with the sealing member 30, .

 The insulating bush 40 is characterized in that the inner circumferential surface width w1 of the space portion 40a is greater than the inner circumferential surface width w2 of the mounting portion 40b. It is preferable that the mounting portion 40b has a relatively small inner width w2 for fixing the sensor element 20 and the space portion 40a has a small thermal loss of the sensor element 20 due to conduction or contact. It is desirable that the inner circumferential surface width w1 is relatively large in order to minimize it.

Specifically, the inner circumferential surface width w2 of the mounting portion 40b may be designed to be about 0.1-0.3 mm larger than the thickness of the sensor element 20 mounted on the mounting portion 40b, and may be closely contacted. For example, when the thickness of the sensor element is 1.3 mm, the inner surface width w2 of the mounting portion 40b is designed to be 1.4 to 1.6 mm, preferably 1.5 mm, so that the sensor element 20 is mounted on the mounting portion 40b It is preferable to adhere as much as possible.

It is preferable that the inner circumferential surface width w1 of the space portion 40a is designed to be larger than the inner circumferential surface width w2 of the mounting portion 40b by about 0.5 to 1 mm. The effect of preventing heat loss can be reduced. Since the pressing force is generally 20 kN or more, the inner peripheral surface width w1 of the space portion 40a is larger than the inner peripheral surface width w1 of the mounting portion 40b If the width (w2) is more than 1 mm, the surface to be press-fitted becomes narrow, and a large force is applied to the insulating bushing, which may be broken.

It is preferable that the height h2 of the mounting portion 40b is larger than the height h1 of the space portion 40a in the insulating bush 40. When the height h2 of the mounting portion 40b is larger than the height h1 of the mounting portion 40b, If the height h1 of the gas sensor 100 is smaller than the height h1 of the space portion 40a, the heat loss prevention effect is excellent. However, the force to support or fix the sensor element 20 may be reduced and the durability of the gas sensor 100 may be drastically reduced.

As described above, an optimal embodiment has been disclosed in the drawings and specification. Although specific terms have been employed herein, they are used for purposes of illustration only and are not intended to limit the scope of the invention as defined in the claims or the claims. Therefore, those skilled in the art will appreciate that various modifications and equivalent embodiments are possible without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

10: sensor housing 20: sensor element
30: sealing member 40: insulating bush
40a: space portion 40b: mounting portion
40c: pressing portion 41: upper insulating bush
42: lower insulating bushing 100: gas sensor

Claims (6)

A gas sensor for detecting gas, comprising:
Wherein the gas sensor comprises: a sensor element located inside the sensor housing;
A sealing member formed on an outer circumferential surface of the sensor element;
And an insulating bush disposed at both ends of the sealing member and formed on an outer circumferential surface of the sensor element,
And a space portion having a predetermined gap with the sensor element is formed at one end of the insulating bush. The method according to claim 1,
Wherein the insulating bush comprises: a mounting part for contacting the sensor element and fixing the sensor element; And
And a pressing portion extending from one side of the mounting portion and contacting and pressing the sealing member,
And the space portion is formed on the other side of the mounting portion. 3. The method of claim 2,
Wherein the width of the inner circumferential surface of the mounting portion is 0.1 to 0.3 mm larger than the thickness of the sensor element mounted on the mounting portion. 3. The method of claim 2,
Wherein the insulating bush has an inner circumferential surface width greater than an inner circumferential surface width of the mounting portion. 5. The method of claim 4,
Wherein the inner circumferential surface width of the space portion is 0.5 to 1 mm larger than the inner circumferential surface width of the mounting portion. 5. The method of claim 4,
Wherein the insulating bush has a height of the mounting portion larger than a height of the space portion.
KR1020150050965A 2015-04-10 2015-04-10 Gas sensor KR20160121236A (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20190000252U (en) * 2017-07-20 2019-01-30 주식회사 한국전자재료(케이.이.엠) Air leakage test jig for ceramic sealing components of oxygen sensor
KR20210080141A (en) 2019-12-19 2021-06-30 (주)센코 Smart sensor and gas detecting device including thereof
KR102553051B1 (en) 2022-11-24 2023-07-10 (주)센코 Smart sensor, gas monitoring system including the same and smart sensor sensing method thereof

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20090083833A (en) 2008-04-10 2009-08-04 한국델파이주식회사 A waterproof structure of o2 sensor for vehicle

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20090083833A (en) 2008-04-10 2009-08-04 한국델파이주식회사 A waterproof structure of o2 sensor for vehicle

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20190000252U (en) * 2017-07-20 2019-01-30 주식회사 한국전자재료(케이.이.엠) Air leakage test jig for ceramic sealing components of oxygen sensor
KR20210080141A (en) 2019-12-19 2021-06-30 (주)센코 Smart sensor and gas detecting device including thereof
KR102553051B1 (en) 2022-11-24 2023-07-10 (주)센코 Smart sensor, gas monitoring system including the same and smart sensor sensing method thereof

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