CN103562713B - Gas sensor - Google Patents
Gas sensor Download PDFInfo
- Publication number
- CN103562713B CN103562713B CN201280026547.8A CN201280026547A CN103562713B CN 103562713 B CN103562713 B CN 103562713B CN 201280026547 A CN201280026547 A CN 201280026547A CN 103562713 B CN103562713 B CN 103562713B
- Authority
- CN
- China
- Prior art keywords
- metal shell
- mentioned
- base metal
- guard member
- detecting element
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Molecular Biology (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Measuring Oxygen Concentration In Cells (AREA)
Abstract
Provided is a gas sensor, the manufacturing cost of which can be reduced and in which the corrosion of a metal shell can be prevented from occurring at a place where a gas detection element and the metal shell are electrically conducted to each other. When exhaust gas contains water vapor, for example, the water vapor penetrates the clearance between a protector (47) and a metal shell (13). The gas sensor (3) according to the present invention, however, prevents corrosion from occurring on the side of the metal shell (13) at a contact portion between a flange portion (57) on the rear end side of the protector (47) and a step portion (17) of the metal shell (13), in such a way that the minimum clearance (W2) between the protector (47) and the metal shell (13) is narrowed and corrosion is allowed to actively occur in the vicinity of an end side of the metal shell (13) (that is, sacrificial protection is used).
Description
Technical field
The present invention relates to one and be equipped on such as two-wheeled (motorcycle) etc. to detect the gas sensor from the oxygen the emission gases that its internal combustion engine (engine) is discharged etc.
Background technology
In the past, as the gas sensor with gas detecting element, such as there will be a known as lower sensor: it possesses the gas detecting element formed by the solid electrolyte body of oxygen conduction, and the waste pipe being installed on motorcycle etc. is to detect the oxygen concentration in emission gases.
As this kind of gas detecting element, such as, there will be a known following gas detecting element: it has the element body of the tubular that tip side is closed, possess medial electrode in the inner side of this element body and possess lateral electrode in outside.
Such as; as shown in Figure 8; following gas sensor P5 is disclosed: gas detecting element P1 is fixed in base metal shell P3 by its metal seal P2 etc. across ring-type, and covers the tip side of the gas detecting element P1 given prominence to from the top of base metal shell P3 with metal guard member P4 in following patent documentation 1.
This gas sensor P5 does not have the well heater for heating gas detecting element P1, namely so-called without heater configuration.In addition, the medial electrode P6 of this gas sensor P5 contacts with terminal metal shell P7, thus make external circuit (not shown) obtain sensor output from terminal metal shell P7, on the other hand, the wire portion P9 that lateral electrode P8 extends with the periphery along gas detecting element P1 is connected, and is electrically connected with base metal shell P3 by wire portion P9 and seal P2.
Patent documentation 1:2009-63330 publication
But in the above prior art, usually, medial electrode P6, lateral electrode P8 and wire portion P9 are formed by platinum, and seal P2, base metal shell P3 are formed by stainless steel (such as SUS430).Therefore; even if reach near seal P2 from the gas introducing port of the guard member P4 detected gas be directed in guard member 4, the contact portion between seal P2 and base metal shell P3, the contact portion between seal P2 and wire portion P9 produce corrosion possibility because of the moisture in detected gas is also lower.In addition, even if the water droplet of inside surface arriving guard member P4 reaches near seal P2, the possibility producing corrosion in contact portion because of water droplet is also lower.
But; when for the purpose of reducing costs with carbon steel at a low price to manufacture base metal shell P3, have contact portion (in base metal shell P3 side) between seal P2 and base metal shell P3 because of the moisture in detected gas, the water droplet arriving the inside surface of guard member P4 and produce the problem of corrosion.And, if create corrosion, then have because conducting deterioration the hidden danger that the gas detect of gas sensor P5 impacts.
On the other hand, by reducing the gap (space) between base metal shell P3 and gas detecting element P1 further, thus detected gas can be made to be difficult to arrive near seal P2, the contact site office between this base metal shell P3 and seal P2 can be suppressed to produce for the base metal shell P3 formed by carbon steel and corrode.In addition, the water droplet being attached to the inside surface of guard member P4 is difficult to arrive near seal P2, thus the contact site office between this base metal shell P3 and seal P2 can be suppressed to produce for the base metal shell P3 formed by carbon steel to corrode.
But adopt said structure, by reducing the gap between base metal shell P3 and gas detecting element P1 further, detected gas is difficult to contact with gas detecting element P1, thus the hidden danger that the accuracy of detection having gas sensor P5 declines.In addition, by reducing the gap between base metal shell P3 and gas detecting element P1, when gas detecting element P1 being held in base metal shell P3, gas detecting element P1 contacts with base metal shell P3, thus have crack on gas detecting element P1, the hidden danger of breach.
Summary of the invention
The present invention completes to solve the problem a little, its object is to provide a kind of and can reduce manufacturing cost and can prevent the position carrying out conducting at gas detecting element and base metal shell from producing the gas sensor of the corrosion of base metal shell.
(1) as the 1st technical scheme, the present invention is a kind of gas sensor, it comprises: gas detecting element, it comprises element body, medial electrode and lateral electrode, this element body extends along axis direction, and the solid electrolyte of the tubular be closed by tip side is formed, this medial electrode is located at the inner side of this element body, and this lateral electrode is located at the outside of this element body, the base metal shell of tubular, it is embedded in the outside of this gas detecting element and the tip side of above-mentioned gas detecting element is given prominence to from the top of this base metal shell self, and the guard member of tubular, itself and this base metal shell fastens, and covers the tip side of above-mentioned gas detecting element, the feature of this gas sensor is, above-mentioned guard member comprises: cylindrical portion, and it extends along above-mentioned axis direction, and the flange part of ring-type, it is located at the rear end side of this cylindrical portion, and expands to radial outside, above-mentioned gas detecting element possesses convex shoulder, this convex shoulder is with spreading all over complete cycle outstanding and on the face on top, have in this convex shoulder self wire portion be electrically connected with above-mentioned lateral electrode to above-mentioned radial outside, and aforementioned body metal shell possesses stage portion, this stage portion is with spreading all over complete cycle outstanding to above-mentioned radially inner side, above-mentioned flange part is sandwiched between the convex shoulder of above-mentioned gas detecting element and the stage portion of aforementioned body metal shell, and make above-mentioned wire portion and the electrical connection of aforementioned body metal shell, aforementioned body metal shell is formed by carbon steel, and the metal material that above-mentioned guard member is less than above-mentioned carbon steel by the content of iron is formed, the tip side place of axis direction is being leaned on than above-mentioned convex shoulder, minimum clearance between above-mentioned guard member and aforementioned body metal shell is narrower than the minimum clearance between above-mentioned guard member and above-mentioned gas detecting element.
In addition, in the present invention, the carbon steel as the material of base metal shell refers to JIS G4051(2010) table 1 in the carbon steel of defined.Specifically, as the material of base metal shell, such as, S17C, S25C etc. can be adopted.
In addition, the content as iron is less than the metal material of the carbon steel of the material as guard member, such as, there are stainless steel.Specifically, such as, there are SUS310S, inconel 750(registered trademark), inconel 601(registered trademark) and ferrite system stainless steel etc.
And then there are at the tip side place leaning on axis direction than convex shoulder, the gap between guard member and gas detecting element and the gap between guard member and base metal shell be uniform example on whole axis direction, but this gap also can be uneven.
In addition; the rear end side place of axis direction is leaned in the convex shoulder than gas detecting element; be formed as the convex shoulder of the stage portion of base metal shell, the flange part of guard member and gas detecting element, for realizing the position of the conducting between lateral electrode and base metal shell; therefore by specifying relation between above-mentioned gap in the convex shoulder than gas detecting element by tip side (being by tip side in detail than the top of convex shoulder) place, the conducting between lateral electrode and base metal shell can reliably be guaranteed.
In addition; " minimum clearance between guard member and gas detecting element " refer to perpendicular to sensor axis and in the dummy line radially extended from the axis of sensor, the minor increment in the distance between the inside surface of guard member and the outside surface of gas detecting element.And then; " minimum clearance between guard member and base metal shell " refer to perpendicular to sensor axis and in the dummy line radially extended from the axis of sensor, the minor increment in the distance between the outside surface of guard member and the inside surface of base metal shell.In addition, when guard member contacts with base metal shell with gas detecting element or guard member, respective minimum clearance is regarded as 0(mm).
In addition, although the gap in circumference between guard member and gas detecting element, gap in the circumference between guard member and base metal shell can be uneven, be more preferably and form uniform gap in the circumferential.That is, for this point near the tip side making corrosion result from base metal shell energetically, be more preferably to spread all over the minimum clearance between guard member and gas detecting element, the minimum clearance between guard member and base metal shell are circumferentially set.
(2) as the 2nd technical scheme, the invention is characterized in, being pressed at least partially and being fixed on aforementioned body metal shell of the cylindrical portion of above-mentioned guard member.
(3) as the 3rd technical scheme; the invention is characterized in; threaded portion above-mentioned gas sensor being fixed on mounting object is possessed at aforementioned body metal shell; and in the region being provided with above-mentioned threaded portion on the above-mentioned axis direction of aforementioned body metal shell, the barrel of aforementioned body metal shell and above-mentioned guard member from.
In addition, more preferably, the press-in portion between the cylindrical portion of preferred guard member and base metal shell is located at the side place rearward, threaded portion than base metal shell.Guard member is easily subject to the heat of emission gases in top ends.Therefore, if press-in portion is located at than threaded portion by tip side place, then the heat of guard member transmits to base metal shell via press-in portion, and heat therefore can be hindered to the rearward end transmission of guard member.On the other hand, if press-in portion is located at than side place rearward, threaded portion, then heat is to the rear end side transmission of guard member, and result can heat gas detecting element better.
(4) as the 4th technical scheme, the invention is characterized in, above-mentioned gas sensor does not have the well heater heated above-mentioned gas detecting element.
In the present invention, base metal shell is formed by carbon steel.Thereby, it is possible to make the cost of base metal shell lower than stainless steel in the past.On this basis, the metal material (such as stainless steel) that guard member is less than carbon steel by the content of iron is formed, and the flange part being located at guard member is sandwiched between the convex shoulder of gas detecting element and the stage portion of base metal shell.Thus, the corrosion potential of base metal shell becomes lower than the corrosion potential of guard member, and when being to produce corrosion between base metal shell and guard member, the stage portion of the base metal shell that corrosion potential is lower is in the state being easy to corrode.In addition, in order to make corrosion result from base metal shell side, the corrosion potential making the corrosion potential of base metal shell lower than guard member is needed.
Like this, in the base metal shell formed by carbon steel, if detected gas, water droplet arrive near the flange part of guard member, then have the hidden danger producing corrosion at base metal shell.Therefore, in the present invention, lean on the tip side place of axis direction in the convex shoulder than gas detecting element, the minimum clearance between guard member and base metal shell becomes narrower than the minimum clearance between guard member and gas detecting element.Thus, detected gas, water droplet are difficult near the flange part of arrival guard member, thus can suppress the situation producing corrosion in the stage portion of base metal shell, and tip side place is leaned on than the stage portion of base metal shell in the position that generation can be made to corrode.
That is, such as go forward side by side and exercise the used time, although water droplet is likely attached to guard member, in this case, near the tip side that corrosion results from (corrosion potential is lower) base metal shell gas sensor being installed on gas outlet etc.
In addition; such as, when being to contain moisture in emission gases; this moisture invades the gap between guard member and base metal shell; but in the present invention; near the tip side being made corrosion result from base metal shell energetically by the gap reduced between guard member and base metal shell (namely sacrificing anticorrosion by arranging), thus can suppress to corrode the base metal shell side of the contact site office resulted between (rear end side) flange part of guard member and the stage portion of base metal shell.
Thereby, it is possible to guarantee conducting (and then conducting between the lateral electrode of gas detecting element (wire portion) and base metal shell) between guard member and base metal shell in long-time.
In addition, guard member is configured at the gap between base metal shell and gas detecting element, and makes the minimum clearance between guard member and gas detecting element wider than the minimum clearance between guard member and base metal shell.Therefore, can suppress to reduce further as in the past the situation that base metal shell produces with the structure in the gap between gas detecting element, detected gas is difficult to contact with gas detecting element, the accuracy of detection of gas sensor can be suppressed to decline.In addition, can also suppress because of gas detecting element when gas detecting element being held in base metal shell contact with base metal shell and crack at gas detecting element, the situation of breach.
In the 2nd technical scheme, the cylindrical portion of guard member is pressed into and is fixed on base metal shell.Namely; owing to not arranging the gap between the cylindrical portion of guard member and base metal shell; therefore; such as, when being to contain moisture in emission gases; this moisture can not arrive than the side place rearward of the press-in portion between guard member and base metal shell; result from the position that is pressed into than the carrying out of base metal shell energetically by making corrosion by (namely sacrificing anticorrosion by arranging) near tip side, thus can prevent from corroding the base metal shell side of the contact site office between flange part and the stage portion of base metal shell resulting from guard member.In addition, although water droplet is likely attached to guard member, in this case, water droplet can not arrive than the side place rearward of the press-in portion between guard member and base metal shell, but produces corrosion near the tip side of base metal shell.
Thereby, it is possible to guarantee conducting (and then conducting between the lateral electrode of gas detecting element (wire portion) and body metal shell) between guard member and base metal shell within the longer time.
And then, by the cylindrical portion of guard member being pressed into and being fixed on base metal shell, the cylindrical portion of guard member is contacted with base metal shell.Therefore, be not only the conducting at the flange part of guard member and the stage portion place of base metal shell, can also the press-in portion between guard member and base metal shell realize conducting.Thus, increase the region that can conduct, thus can reliably realize conducting.
And then; in gas sensor of the present invention; such as, the heat of emission gases is utilized heat gas detecting element to guard member transmission from the radiation heat of this guard member, thus make this gas detecting element be in (detection of oxygen concentration etc. can be carried out) activated state.
And then; as this 3rd technical scheme; by make in the region being provided with the threaded portion for above-mentioned gas sensor being installed on gas outlet etc. on the axis direction of base metal shell the barrel of base metal shell and guard member from, thus the heat with guard member is difficult to utilize heat transfer and externally releases (being namely difficult to cool) such effect via base metal shell.Therefore, such as, the guard member being discharged gas-heated can be utilized to heat gas detecting element preferably.As a result, there is the advantage that the detection that promptly can start such as oxygen concentration etc. is such.
The gas sensor of this 4th technical scheme is so-called heaterless gas sensor.In this heaterless gas sensor; especially by the heat of emission gases is utilized heated gas detecting element to guard member transmission from the radiation heat of this guard member, thus this gas detecting element is made to be in (detection of oxygen concentration etc. can be carried out) activated state.Thus, by having said structure, can effectively heat gas detecting element.
Accompanying drawing explanation
Fig. 1 represents that cutting in the axial direction possesses the key diagram of the state of the gas sensor unit of the gas sensor of the 1st embodiment.
Fig. 2 is the key diagram of the state of the gas sensor representing cutting in the axial direction the 1st embodiment.
Fig. 3 is biopsy cavity marker devices gas detecting element and carries out the front view that represents.
Fig. 4 is the front view representing guard member.
Fig. 5 is cutting gas detecting element and expands its major part and carry out the key diagram that represents.
Fig. 6 is the key diagram of the sample representing the gas sensor used in experiment.
Fig. 7 is the gas detecting element of the gas sensor of cutting the 2nd embodiment and expands its major part and carry out the key diagram that represents.
Fig. 8 is the key diagram of prior art.
Embodiment
Below with reference to accompanying drawing, embodiments of the present invention are described.
1st embodiment
At this, illustrate the gas sensor unit of the gas sensor possessing the 1st embodiment.
As shown in Figure 1, the gas sensor unit 1 of the 1st embodiment comprises: the gas sensor 3 of tubular, and it extends along axes O direction; And sensor wrap 5, it is configured at the rear end side (upside of Fig. 1) in the axes O direction of this gas sensor 3.
This gas sensor unit 1 is following lambda sensor: it is assembled in this gas outlet to make the tip portion of gas sensor 3 to outstanding mode in the gas outlet (not shown) of the vehicles such as such as motorcycle, and measures the oxygen concentration in emission gases.
Below, each structure is described.In addition, in the following description, by along in the direction of axes O, the side of sensor installation cover 5 is set to rear end side, the side contrary with above-mentioned rear end side is set to tip side, and is described.
A) first, the structure of gas sensor 3 is described.
As shown in Figure 2, the gas sensor 3 of present embodiment mainly comprises gas detecting element 7, ceramic sleeve 9, terminal component 11 and base metal shell 13.
This gas sensor 3 does not possess the well heater for heating gas detecting element 7, is so-called heaterless sensor, and this gas sensor 3 utilizes the heat of emission gases to make gas detecting element 7 activate, thus measures oxygen concentration.
Base metal shell 13 in the structure of gas sensor 3 is the components of the cylindrical shape formed by the such as S17C of carbon steel.In order to support the convex shoulder 15 of gas detecting element 7 described later, to the cone-shaped of tip side (downside of Fig. 2) undergauge stage portion 17 with from the inner peripheral surface mode outstanding to radially inner side around being arranged at this base metal shell 13.
In addition, being formed with the threaded portion 19 for gas sensor 3 being installed on gas outlet at the outer peripheral face of the tip side of base metal shell 13, being surrounded with the hexagonal portion 21 for the erecting tools engaging for threaded portion 19 being screwed in gas outlet in the rear end side (upside of Fig. 2) of this threaded portion 19.
And then, the cylindrical portion 23 of rear end side, ceramic sleeve 9 etc. for receiving gas detecting element 7 is provided with in the rear end side of this base metal shell 13.
As shown in Figure 3, gas detecting element 7 has the element body 8 of tubular, and this element body 8 is formed by the solid electrolyte with oxygen-ion conductive, in top ends 25 be closed have end shape, and to extend along axes O direction.The convex shoulder 15 outstanding to radial outside is surrounded with in the periphery of this element body 8.
In addition, as the solid electrolyte of composed component main body 8, representational solid electrolyte is such as make Y
2o
3or the ZrO of CaO solid solution
2, in addition, oxide and the ZrO of alkaline-earth metal or rare earth metal also can be used
2solid solution.And then this solid solution also can contain HfO
2.
Lateral electrode 27 is formed at the outer peripheral face of element body 8 at top ends 25 place of this gas detecting element 7.This lateral electrode 27 is formed by Pt or Pt alloy is formed as vesicular.From this lateral electrode 27, be formed with along axis direction the vertical wire portion 29 formed by Pt etc., and this wire portion 29 is connected to the side, face towards top (downside of Fig. 3) being annularly formed at convex shoulder 15, wire portion in the ring-type wire portion 31(right that formed by Pt etc.).
On the other hand, medial electrode 33 is formed with at the inner peripheral surface of the element body 8 of gas detecting element 7.This medial electrode 33 is also formed by Pt or Pt alloy is formed as vesicular.
Get back to Fig. 2, ceramic sleeve 9 is formed by insulating ceramics (specifically aluminium oxide), and has cylindrical shape.About this ceramic sleeve 9, the tip side part 35 of heavy wall with surround than gas detecting element 7 convex shoulder 15 rearward the mode of the surrounding of the part of side remain together with the ceramic powders 37 formed by talcum and be located between gas detecting element 7 and base metal shell 13.
Terminal component 11 is the metal terminal of following tubular: it is inserted in the space 39 of the inside of gas detecting element 7, obtains sensor export by contacting with medial electrode 33.This terminal component 11 is such as formed by inconel (English inconel society, trade (brand) name), and has the outgoing side portion of terminal 41 of sensor wrap 5 side, the component side portion of terminal 43 contacted with medial electrode 33 and terminal connection part 45 both being connected.
B) then, the major part of the gas sensor 3 of present embodiment is described.
In the present embodiment, be configured with in the mode being covered to tip side from the convex shoulder 15 of gas detecting element 7 the rectangular guard member 47 formed by stainless steel (such as SUS310S).
As shown in Figure 4, this guard member 47 is the cylindrical body being provided with the multiple air holes 49 for emission gases being imported to inside in its tip side, and this guard member 47 possesses: the discoid top ends 51 of tip side; Cylindrical portion 53, it extends side backward from top ends 51; And the flange part 57 of ring-type, it is located at the rearward end of cylindrical portion 53, and extends side backward in the mode of outside peripheral, oblique.In addition, exhaust opening 55(is provided with reference to Fig. 5 in top ends 51).
Especially in the present embodiment; as represented after expanding in Figure 5, the flange part 57 of guard member 47 is clipped in the state be pressed between the upper surface 61 of the face 59 towards top of the convex shoulder 15 of gas detecting element 7 and the stage portion 17 of base metal shell 13.
Thus, the lateral electrode 27 that conducts of the ring-type wire portion 31(of gas detecting element 7 and this wire portion 31), guard member 47 and base metal shell 13 be electrically connected.
In addition, guard member 47 is pressed into and is fixed on base metal shell 13.In detail, the cylindrical portion 53 of guard member 47 is pressed into and is fixed on annularly outstanding along axis side from the inner peripheral surface of base metal shell 13 press-in portion 54.At this press-in portion 54 place, cylindrical portion 53 is mutually closely sealed with base metal shell 13.In addition, the length on the axis direction of press-in portion 54 is such as 1.5mm.
And then the cylindrical portion 53 that the space of the tubular between the outer peripheral face of gas detecting element 7 and the inner peripheral surface of base metal shell 13 is protected 47 is divided into cylindric inner space 63 and cylindric outer space 65.
And, in the region (the T region of Fig. 5) being provided with threaded portion 19 on the axis direction of base metal shell 13, utilize outer space 65 to be separated by the inner peripheral surface of the outer peripheral face of guard member 47 with base metal shell 13.
And; in the present embodiment; than convex shoulder 15(be the top of axis direction of convex shoulder 15 in detail) by the tip side (the H region of Fig. 5) of axis direction; minimum clearance between guard member 47 and base metal shell 13 (namely; the minimum clearance of outer space 65) be set to less than the minimum clearance (that is, the minimum clearance of inner space 63) between guard member 47 and gas detecting element 7.
In detail; representing as expanded local in the same figure; minimum clearance W2(between guard member 47 and base metal shell 13 such as, 0mm) than the minimum clearance W1(between guard member 47 and gas detecting element 7 such as, 0.35mm) narrow.In addition, the cylindrical portion 53 due to guard member 47 is pressed in base metal shell 13, and therefore minimum clearance W2 is 0mm.
In addition, in the present embodiment, the minimum clearance W1 between guard member 47 and the gas detecting element 7 and minimum clearance W2 between guard member 47 and base metal shell 13 is all positions of the top end of convex shoulder 15, but is not limited thereto.
C) then, the structure of simple declaration sensor wrap 5.
Get back to Fig. 1, sensor wrap 5 mainly possesses cover terminal 67, covering member 69, wire 71 and filter element 73.
Cover terminal 67 is components that the mode of the rear end side clipping ceramic sleeve 9 embeds from the upside of same accompanying drawing, such as, formed by stainless steel (SUS310S etc.), and utilize drawing processing etc. that sheet material is formed as double-deck substantially cylindrical shape.
This cover terminal 67 has: the annulus 75 of tabular, and it is concentric annular about axes O; Handle part 77, it is connected with the neighboring of annulus 75 and outstanding to the side (downside of same accompanying drawing) along axes O; And the insertion section 79 of cylindrical shape, it is connected with the inner periphery of annulus 75 and outstanding to the side identical with handle part 77.
Covering member 69 is for covering and keeping the component of cover terminal 67, forms the cover terminal accommodation space 81 of storage cover terminal 67 by using the fluorine-based rubber of insulativity that this covering member 69 is configured as hollow shape.
This covering member 69 have when forming gas sensor unit 1 with open lower side from the mode of the rear end side of cover terminal 67 and ceramic sleeve 9 to same accompanying drawing in conjunction with peristome 83, and the filtration intercommunicating pore 85 had for receiving filter element 73 and the wire intercommunicating pore 87 for receiving wire 71.
The PTFE that filter element 73 is constructed by the continuous poriferous matter of fine pores continuous print is formed, and is imported in the space 39 of the inside of gas detecting element 7 via cover terminal accommodation space 81 by the air of filter element 73.
Wire 71 also has clad material except heart yearn.The tip side of this wire 71 extends in conjunction with peristome 83 side, and is riveted by the caulking part 89 of wire fixed component 88.
This wire fixed component 88 has substantially cylindrical shape, and except caulking part 89, also have the fitting portion 93 for the clad material fixed part 91 of fixing cord (clad material) and the inwall tabling with the insertion section 77 of cover terminal 67.And this wire fixed component 88 is pressed against the peristome 95 of the axis centre of cover terminal 67 and is integrally constituted with this peristome 95.
Thus, when sensor wrap 5 is installed on the rear end side of gas sensor 3, be embedded with the cover terminal 67 possessing wire fixed component 88 in the rear end side of gas detecting element 7, thus this cover terminal 67 is electrically connected with (contacting with the medial electrode 33 of gas detecting element 7) terminal component 11.
Thus, terminal component 11 is connected with wire 71 with wire fixed component 88 via cover terminal 67, the output signal external device of the medial electrode 33 of the gas detecting element 7 from gas sensor 3 (such as, control unit of engine (ECU)) can be transmitted by this wire 71.
D) then, the manufacture method of simple declaration gas sensor unit 1.
First, as shown in Figure 1, from the upside of same accompanying drawing, guard member 47 is embedded the through hole 97 of the axis centre of base metal shell 13.Now, guard member 47 is pressed into until the flange part 57 of guard member 47 is connected to the stage portion 17 of base metal shell 13.In addition, the cylindrical portion 53 of guard member 47 is pressed into and is fixed on base metal shell 13.
Then, by the through hole 97 being provided with lateral electrode 27, the gas detecting element 7 of medial electrode 33 inserts base metal shell 13.Now, gas detecting element 7 is inserted until the convex shoulder 15 of gas detecting element 7 is connected to the flange part 57 of guard member 47.Thus, the ring-type wire 31 of the lower surface 59 of convex shoulder 15 contacts with flange part 57 (with reference to Fig. 5) and is electrically connected.
Then, ceramic powders 37 is filled in gap portion between base metal shell 13 and gas detecting element 7 with scheduled volume.
Then, to make tip side part 35 mode be located between gas detecting element 7 and base metal shell 13 of ceramic sleeve 9 insert ceramic sleeve 9, and this ceramic sleeve 9 is made to be connected to ceramic powders 37.
Then, towards tip side, ceramic sleeve 9 is pressurizeed, and to make riveted joint ring 101(with reference to Fig. 1 under this pressurized state) be located in the caulking part 99(of base metal shell 13 with reference to Fig. 1) and ceramic sleeve 9 between mode caulking part 99 is riveted, thus said structure parts to be fixed as one.
Then, terminal component 11 is inserted the inner side of ceramic sleeve 9 and gas detecting element 7.Specifically, make the component side portion of terminal 43 flexibly undergauge of terminal component 11, while be inserted in gas detecting element 7, and be electrically connected with medial electrode 33.Meanwhile, to tip side press-in outgoing side portion of terminal 41, and make its petal-like retainer 103(with reference to Fig. 1) be connected to the rear end face of ceramic sleeve 9.Thus, gas sensor 3 is completed.
Afterwards, by sensor wrap 5 being embedded the rear end side of gas sensor 3 and cover terminal 67 being embedded terminal component 11, thus gas sensor 3 is integrated with sensor wrap 5, complete gas sensor unit 1.
E) then, the action effect of the present embodiment based on said structure is described.
In the present embodiment, base metal shell 13 is formed by the such as S17C as carbon steel.Thus, compared with the past, cost can be made lower than the stainless steel of base metal shell 13.On this basis, guard member 47 is formed by stainless such as SUS310S, and the flange part 57 being located at guard member 47 is sandwiched between the convex shoulder 15 of gas detecting element 7 and the stage portion 17 of base metal shell 13.Thus; the corrosion potential of base metal shell 13 becomes lower than the corrosion potential of guard member 47; when being to produce corrosion between base metal shell 13 and guard member 47, the stage portion 17 of the base metal shell 13 that corrosion potential is lower is in holds corrosion-prone state.
Therefore, in the present embodiment, lean on the tip side H place in axes O direction in the convex shoulder 15 than gas detecting element 7, the minimum clearance W2 between guard member 47 and base metal shell 13 is narrower than the minimum clearance W1 between guard member 47 and gas detecting element 7.Thus, detected gas, water droplet are difficult near the flange part 57 of arrival guard member 47, thus can not produce corrosion in the stage portion 17 of base metal shell 13, generation can be made to have the position of corrosion to be positioned at and lean on tip side place than the stage portion 17 of base metal shell 13.
That is, such as go forward side by side and exercise the used time, although water droplet is likely attached to guard member 47, in this case, near the top that corrosion results from (corrosion potential is lower) base metal shell 13 gas sensor unit 1 being installed on gas outlet.
In addition; such as, when being to contain moisture in emission gases; this moisture invades the gap between guard member 47 and base metal shell 13; but in the present embodiment; near the tip side being made corrosion result from base metal shell 13 energetically by the minimum clearance W2 reduced between guard member 47 and base metal shell 13 (namely sacrificing anticorrosion by arranging), thus suppress corrosion result from contact portion between the flange part 57 of the rear end side of guard member 47 and the stage portion 17 of base metal shell 13, the side of base metal shell 13.
Thereby, it is possible to guarantee in long-time to conduct conducting between (and then lateral electrode 27(ring-type wire portion 31 of gas detecting element 7) and base metal shell 13 between guard member 47 and base metal shell 13).
On this basis, guard member 47 is configured at the gap between base metal shell 13 and gas detecting element 7, and makes the minimum clearance W1 between guard member 47 and gas detecting element 7 wider than the minimum clearance W2 between guard member 47 and base metal shell 13.Therefore, can suppress to reduce further as in the past the situation that base metal shell produces with the structure in the gap between gas detecting element, detected gas is difficult to contact with gas detecting element, the accuracy of detection of gas sensor can be suppressed to decline.In addition, can also suppress because of gas detecting element when gas detecting element being held in base metal shell contact with base metal shell and crack at gas detecting element, the situation of breach.
In addition, in the present embodiment, a part for the cylindrical portion 53 of guard member 47 is pressed into and is fixed on base metal shell 13.Namely, owing to not arranging the gap W2 between the cylindrical portion 53 of guard member 47 and base metal shell 13, therefore, such as, when being to contain moisture in emission gases, this moisture can not arrive than the side place rearward of the press-in portion 54 between guard member 47 and base metal shell 13, result from energetically by making corrosion and lean on (namely by arranging sacrifice anticorrosion) near tip side than the press-in portion 54 of base metal shell 13, thus can prevent from corroding and result from contact portion between the flange part 57 of guard member 47 and the stage portion 17 of base metal shell 13, the side of base metal shell 13.In addition; although water droplet is likely attached to guard member 47; but in this case, water droplet can not arrive than the side place rearward of the press-in portion 54 between guard member 47 and base metal shell 13, but in the press-in portion 54 than base metal shell 13 by producing corrosion near tip side.Thereby, it is possible to guarantee conducting (and then conducting between lateral electrode 27 and base metal shell 13) between guard member 47 and base metal shell 13 in more long-time.
And then the cylindrical portion 53 due to guard member 47 is pressed into and is fixed on base metal shell 13, therefore the cylindrical portion 53 of guard member 47 contacts with base metal shell 13.Therefore; be not only the flange part 57 of guard member 47 and the conducting at stage portion 17 place of base metal shell 13, can also the press-in portion 54 between guard member 47 and base metal shell 13 realize conducting (and then conducting between lateral electrode 27 and base metal shell 13).Thus, increase the region that can conduct, thus can reliably realize conducting.
And then; in the present embodiment; by making base metal shell 13 be separated with the cylindrical portion 53 of guard member 47 in the region T being provided with the threaded portion 19 for being installed on gas outlet etc. on the axes O direction of base metal shell 13, thus the heat of guard member 47 is made to be difficult to be sidelong out to gas outlet via base metal shell 13 because of heat transfer.Therefore, it is possible to utilize the guard member 47 being discharged gas-heated to heat gas detecting element 7 preferably.Its result, has the advantage that the detection that promptly can start oxygen concentration is such.
On this basis, gas sensor 3 is so-called heaterless gas sensors.In this heaterless gas sensor 3; especially by being transmitted to guard member 47 by the heat of emission gases and utilizing the radiation heat from this guard member 47 to heat gas detecting element 7, thus this gas detecting element 7 is made to be in (detection of oxygen concentration etc. can be carried out) activated state.Thus, by having said structure, can effectively heat gas detecting element 7.
F) then, illustrate to confirm the experimental example that effect of the present invention is carried out.
In this experimental example, as the sample (embodiment 1,2) in scope of the present invention, as described in Table 1, change the material of base metal shell and guard member, manufacture the sample of the structure gas sensor 111 identical with the structure of above-mentioned embodiment.
In addition, as extraneous sample of the present invention (comparative example 1,2), manufacture the gas sensor being configured with the structure of (SUS430's) seal of ring-type as structure (with reference to Fig. 8) in the past between gas detecting element and base metal shell.
In addition, in each sample, the vertical wire portion be connected with the lateral electrode of gas detecting element is extended and is formed to rear end.In addition, not splicing ear component.
Experimental technique is as described below.
First, for each sample of gas sensor 111, detect the resistance (initial resistance) between lateral electrode (i.e. vertical wire portion) and base metal shell.Its result is described in following table 1.
Then, as shown in Figure 6, the hub 115 of (top closure) tubular formed by aluminium screwed togather and be fixed on the threaded portion 113 of the tip side of each gas sensor 111.In addition, now, pH is filled in the inner space 117 of hub 115
2aqueous acetic acid.
Then, this each sample put into stove and rises to 150 DEG C, heating 100 hours at such a temperature, afterwards, be cooled to room temperature.
Then, take out each sample from stove, remove hub 115 from each gas sensor 111, each sample for gas sensor 111 detects the resistance (resistance to resistance long afterwards) between lateral electrode (i.e. vertical wire portion) and base metal shell.This result is described in following table 1.
[table 1]
As by this table 1 clear and definite, in the sample of embodiments of the invention 1,2, even if when employing carbon steel (S17C) as base metal shell, for initial resistance, resistance to resistance long afterwards also there is no too large change, is therefore preferred.
On the other hand, in comparative example 2, when employing low-cost carbon steel (S17C) as base metal shell, resistance to resistance long afterwards significantly increases, therefore not preferred.
In addition, in the case of comparative example 1, though resistance to resistance long afterwards does not significantly increase, but the material of base metal shell is the stainless steel (SUS430) of high price, therefore not preferred in cost this point.
2nd embodiment
Then, based on Fig. 7, the 2nd embodiment of the present invention is described.
In addition; in the 2nd embodiment; in gas sensor 203, guard member 247 is different with the gas sensor 3 of the 1st embodiment from the structure of base metal shell 213; in the following description; describe guard member 247 and the structure of base metal shell 213 in detail, simplify or omit the explanation at other positions.
In the structure of gas sensor 203, base metal shell 213 is the components of the cylindrical shape formed by the such as S17C of carbon steel.In order to support the convex shoulder 215 of gas detecting element 207, towards the stage portion 217 of the cone-shaped of tip side (downside of Fig. 7) undergauge in mode outstanding to radially inner side from inner peripheral surface around being arranged at this base metal shell 213.
In addition, be formed with the threaded portion 219 for gas sensor 203 being installed on gas outlet at the outer peripheral face of the tip side of base metal shell 213, and be surrounded with the hexagonal portion 221 for the erecting tools engaging for threaded portion 219 being screwed in gas outlet in the rear end side (upside of Fig. 7) of this threaded portion 219.
In the 2nd embodiment, be configured with in the mode being covered to tip side from the convex shoulder 215 of gas detecting element 207 the rectangular guard member 247 formed by stainless steel (such as SUS310S).
As shown in Figure 7, this guard member 247 is the cylindrical body being provided with the multiple air holes 249 for emission gases being imported to inside in its tip side, and this guard member 247 possesses: the discoid top ends 251 of tip side; Cylindrical portion 253, it extends side backward from top ends 251; And the flange part 257 of ring-type, it is located at the rearward end of cylindrical portion 253, and extends side backward in the mode of outside peripheral, oblique.
Especially in the 2nd embodiment, between the upper surface 261 that the stage portion 217 of the flange part 257 of guard member 247 is clipped in the inclination of the convex shoulder 215 of gas detecting element 207 lower surface 259 and base metal shell 213 with the state be pressed tilts.
Thus, the ring-type wire portion 231(of gas detecting element 207 and then lateral electrode 227), guard member 247 and base metal shell 213 be electrically connected, be therefore formed as via the structure of base metal shell 213 in external ground.
And then the cylindrical portion 253 that the space of the tubular between the outer peripheral face of gas detecting element 207 and the inner peripheral surface of base metal shell 213 is protected 247 is divided into cylindric inner space 263 and cylindric outer space 265.
And; in the 2nd embodiment; the tip side (the H region of Fig. 7) of axis direction is being leaned on than convex shoulder 215; minimum clearance between guard member 247 and base metal shell 213 (namely; the minimum clearance of outer space 265) be set to less than the minimum clearance (that is, the minimum clearance of inner space 263) between guard member 247 and gas detecting element 207.
In detail; as shown in Figure 7; the protuberance 214 to the outstanding ring-type of radial direction is possessed by the inner peripheral surface of the tip side at base metal shell 213; minimum clearance W2(between guard member 247 and base metal shell 213 such as; 0.15mm) become than the minimum clearance W1(between guard member 247 and gas detecting element 7 such as, 0.35mm) narrow.In addition; in the 2nd embodiment; be the position of the top end of convex shoulder 215 relative to the minimum clearance W1 between guard member 247 and gas detecting element 207, the minimum clearance W2 between guard member 247 and base metal shell 213 is formed at the tip side of base metal shell 213.
In the 2nd embodiment; lean on the tip side H place in axes O direction in the convex shoulder 215 than gas detecting element 207, the minimum clearance W2 between guard member 247 and base metal shell 213 also becomes narrower than the minimum clearance W1 between guard member 247 and gas detecting element 207.Thereby, it is possible to the position making generation corrode is positioned at lean on tip side place than the stage portion 217 of base metal shell 213, and corrosion can not be made to result from the stage portion 217 of base metal shell 213.
Namely, such as, when being to contain moisture in emission gases, this moisture invades in the gap between guard member 247 and base metal shell 213, but in the present embodiment, near the tip side being made corrosion result from base metal shell 213 energetically by the minimum clearance W2 reduced between guard member 247 and base metal shell 213 (namely sacrificing anticorrosion by arranging), thus suppress corrosion to result from contact portion between the flange part 257 of the rear end side of guard member 247 and the stage portion 217 of base metal shell 213, the side of base metal shell 213.In addition, such as, although water droplet is likely attached to guard member 247, in this case, corrosion will be produced near the top of (corrosion potential is lower) base metal shell 213.
Above, describe embodiments of the present invention, but the present invention is not limited to above-mentioned embodiment, without departing from the spirit and scope of the invention, can implements with various technical scheme.
Such as, in the 1st embodiment and the 2nd embodiment, describe the gas sensor unit 1 sensor wrap 5 being embedded gas sensor 3,203, but be not limited thereto, even do not use sensor wrap 5 but wire run through the known gas sensor inside and outside sensor, also structure of the present invention can be applied.
description of reference numerals
1, gas sensor unit; 3,203, gas sensor; 5, sensor wrap; 7,207, gas detecting element; 8, element body; 9, ceramic sleeve; 13,213, base metal shell; 15,215, convex shoulder; 17,217, stage portion; 19,219, threaded portion; 23,253, cylindrical portion; 27,227, lateral electrode; 31, ring-type wire portion; 33, medial electrode; 47,247, guard member; 57,257, flange part; 63,263, inner space; 65,265, outer space.
Claims (4)
1. a gas sensor, it comprises:
Gas detecting element, it comprises element body, medial electrode and lateral electrode, this element body extends along axis direction, and the solid electrolyte of the tubular be closed by the tip side of this element body is formed, this medial electrode is located at the inner side of this element body, and this lateral electrode is located at the outside of this element body;
The base metal shell of tubular, it is embedded in the outside of this gas detecting element and the tip side of above-mentioned gas detecting element is given prominence to from the top of this base metal shell self; And
The guard member of tubular, itself and this base metal shell fastens, and covers the tip side of above-mentioned gas detecting element; The feature of this gas sensor is,
Above-mentioned guard member comprises: cylindrical portion, and it extends along above-mentioned axis direction; And the flange part of ring-type, it is located at the rear end side of this cylindrical portion, and expands to radial outside;
Above-mentioned gas detecting element possesses convex shoulder, this convex shoulder is with spreading all over complete cycle outstanding and on the face on top, have in this convex shoulder self wire portion be electrically connected with above-mentioned lateral electrode to above-mentioned radial outside, and aforementioned body metal shell possesses stage portion, this stage portion is with spreading all over complete cycle outstanding to above-mentioned radially inner side
Above-mentioned flange part is sandwiched between the convex shoulder of above-mentioned gas detecting element and the stage portion of aforementioned body metal shell, and makes above-mentioned wire portion and the electrical connection of aforementioned body metal shell,
Aforementioned body metal shell is formed by carbon steel, and the metal material that above-mentioned guard member is less than above-mentioned carbon steel by the content of iron is formed,
Leaning on the tip side place of axis direction than above-mentioned convex shoulder, the minimum clearance between above-mentioned guard member and aforementioned body metal shell is narrower than the minimum clearance between above-mentioned guard member and above-mentioned gas detecting element.
2. gas sensor according to claim 1, is characterized in that,
Being pressed at least partially and being fixed on aforementioned body metal shell of the cylindrical portion of above-mentioned guard member.
3. gas sensor according to claim 2, is characterized in that,
Threaded portion above-mentioned gas sensor being fixed on mounting object is possessed at aforementioned body metal shell,
And in the region being provided with above-mentioned threaded portion on the above-mentioned axis direction of aforementioned body metal shell, the barrel of aforementioned body metal shell and above-mentioned guard member from.
4. gas sensor according to claim 3, is characterized in that,
Above-mentioned gas sensor does not have the well heater heated above-mentioned gas detecting element.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2011-178352 | 2011-08-17 | ||
| JP2011178352 | 2011-08-17 | ||
| PCT/JP2012/005057 WO2013024579A1 (en) | 2011-08-17 | 2012-08-09 | Gas sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103562713A CN103562713A (en) | 2014-02-05 |
| CN103562713B true CN103562713B (en) | 2015-07-08 |
Family
ID=47714918
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201280026547.8A Active CN103562713B (en) | 2011-08-17 | 2012-08-09 | Gas sensor |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP5947726B2 (en) |
| CN (1) | CN103562713B (en) |
| DE (1) | DE112012003364B4 (en) |
| WO (1) | WO2013024579A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6710596B2 (en) * | 2016-07-06 | 2020-06-17 | 日本特殊陶業株式会社 | Gas sensor |
| JP7144203B2 (en) * | 2018-06-13 | 2022-09-29 | 三菱重工業株式会社 | Corrosion sensor and manufacturing method of corrosion sensor |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5371894A (en) * | 1976-12-07 | 1978-06-26 | Nippon Denso Co Ltd | Oxygen concentration detector |
| JPS56135147A (en) * | 1980-03-26 | 1981-10-22 | Sogo Jidosha Anzen Kogai Gijutsu Kenkyu Kumiai | Oxygen concentration detector |
| JPS6335406Y2 (en) * | 1980-05-07 | 1988-09-20 | ||
| IT1144700B (en) * | 1981-04-07 | 1986-10-29 | Harris Pharma Ltd | PROCEDURE FOR THE PREPARATION OF A GLYCINE DERIVATIVE |
| JPH0131962Y2 (en) * | 1981-05-09 | 1989-10-02 | ||
| JP4936132B2 (en) | 2007-09-04 | 2012-05-23 | 日本特殊陶業株式会社 | Gas sensor unit |
-
2012
- 2012-08-09 DE DE112012003364.7T patent/DE112012003364B4/en active Active
- 2012-08-09 CN CN201280026547.8A patent/CN103562713B/en active Active
- 2012-08-09 JP JP2012548164A patent/JP5947726B2/en active Active
- 2012-08-09 WO PCT/JP2012/005057 patent/WO2013024579A1/en active Application Filing
Also Published As
| Publication number | Publication date |
|---|---|
| WO2013024579A1 (en) | 2013-02-21 |
| JPWO2013024579A1 (en) | 2015-03-05 |
| DE112012003364B4 (en) | 2022-06-23 |
| DE112012003364T5 (en) | 2014-04-30 |
| JP5947726B2 (en) | 2016-07-06 |
| CN103562713A (en) | 2014-02-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103718034B (en) | Gas sensor | |
| JP5529070B2 (en) | Gas sensor | |
| JP2009276339A (en) | Sensor | |
| JP5310170B2 (en) | Gas sensor and manufacturing method thereof | |
| CN103562713B (en) | Gas sensor | |
| JP2011215095A (en) | Gas sensor | |
| CN103547916B (en) | Gas sensor | |
| WO2013168649A1 (en) | Gas sensor | |
| JP5139373B2 (en) | Gas sensor mounting structure and gas sensor with protective cover | |
| US7827849B2 (en) | Gas sensor | |
| JP6602250B2 (en) | Gas sensor | |
| EP1793223B1 (en) | Gas sensor | |
| JP2012083327A (en) | Gas sensor | |
| JP6170440B2 (en) | Gas sensor | |
| JP5268193B2 (en) | Gas sensor | |
| JP2017203632A (en) | Gas sensor and manufacturing method for the same | |
| JP5152863B2 (en) | Gas sensor | |
| JP2019027917A (en) | Gas sensor | |
| JP6316580B2 (en) | Gas sensor | |
| JP6026904B2 (en) | Gas sensor and manufacturing method thereof | |
| JP5931701B2 (en) | Gas sensor | |
| JP5215358B2 (en) | Gas sensor | |
| JP2010236940A (en) | Gas sensor | |
| JP2015090274A (en) | Gas sensor | |
| JP2009198189A (en) | Gas sensor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |