CN201955324U

CN201955324U - Tube-type double-battery wide oxygen sensor

Info

Publication number: CN201955324U
Application number: CN2010206928800U
Authority: CN
Inventors: 冯江涛; 杨世养; 党桂彬
Original assignee: CHANGZHOU LIANDE ELECTRONICS CO LTD
Current assignee: CHANGZHOU LIANDE ELECTRONICS CO LTD
Priority date: 2010-12-31
Filing date: 2010-12-31
Publication date: 2011-08-31
Anticipated expiration: 2020-12-31

Abstract

The utility model relates to the technical field of oxygen sensors, particularly to a tube-type double-battery wide oxygen sensor, which comprises an inner zirconia pipe, an outer zirconia pipe, a heating rod and a close-loop controller, wherein the outer surface of the inner zirconia pipe and the inner surface of the outer zirconia pipe are mutually matched; a diffusion cavity is reserved between the top ends of the inner zirconia pipe and the outer zirconia pipe after the inner zirconia pipe and the outer zirconia pipe are stacked; a reference gas passage is arranged on the inner surface of the inner zirconia pipe and provided with a platinum electrode to form a reference electrode; a measuring electrode is arranged on the outer surface of the inner zirconia pipe and tangent to the inner surface of the outer zirconia pipe to form an inner electrode of a pump battery; an outer electrode for the pump battery is arranged on the outer surface of the outer zirconia pipe; small holes are formed at the top of the outer zirconia pipe; a diffusion obstacle hole used for filling a diffusion layer is arranged at the top of the outer zirconia pipe; and a porous outer electrode protective layer is arranged on the outer layer of the outer zirconia pipe. The prepared tube-type double-battery wide oxygen sensor has simple structure and small processing difficulty.

Description

Tubular type double cell molded breadth domain oxygen sensor

Technical field

The utility model relates to the lambda sensor technical field, especially a kind of tubular type double cell molded breadth domain oxygen sensor.

Background technology

Raising day by day along with motor vehicle exhaust emission rules and engine control technology, traditional concentration difference type lambda sensor all can't satisfy the requirement of engine control system on measuring accuracy and measurement range, therefore the double cell molded breadth domain oxygen sensor based on the limiting current principle arises at the historic moment.Present existing double cell molded breadth domain oxygen sensor all is a slice structure; this structure generally is to obtain zirconium oxide substrate by the flow casting molding technology; become required shape with perforation processing by cutting; it is integrated with zirconia matrix and heater circuit, metal platinum electrode, porous protective layer and diffusion barrier layer to be total to burning technology by serigraphy and lamination again; thereby form the dual-battery structure of concentration cell pipe and limiting current pump battery pipe; and comprise well heater, diffusion barrier layer and porous protective layer.By the thickness of adjustment diffusion barrier layer and the pore size and the density of formation, can obtain metastable limiting current size.

In working order down, apply pump voltage by closed loop controller at pump battery pipe internal and external electrode end and produce certain pump electric current, make the potential electrode contrast electrode two ends of concentration cell pipe produce the voltage about 450mV, and the output characteristics of this pump electric current also is to be linear positive current in the lean burn stage in air-fuel ratio greater than 1, equaling at 1 o'clock in air-fuel ratio is 0, and air-fuel ratio less than 1 o'clock output negative current, this lambda sensor just can be measured in very wide air-fuel ratio scope like this, thereby make it except the control that realizes λ=1, can also carry out engine underpressure burning control, diesel motor and CNG engine control, industrial combustion control and the accurate measurement of tail gas etc.

This chip double cell molded breadth domain oxygen sensor need maintain the temperature of sensing and measuring point between 700 ~ 800 ° of C in order to obtain higher measuring accuracy under low pump voltage always; Meanwhile start-up time, its integrated heater circuit must have sufficiently high heating power to satisfy the requirement of maximum discharge rules faster in order to obtain.Like this,, can cause its stable and decline in serviceable life because asymmetric and irregular self heat resistanceheat resistant performance of shaking that causes of slice structure itself descends.In addition, only need 2 to compare to 3-tier architecture with traditional concentration difference type sensor, this double cell molded breadth domain oxygen sensor needs integrated 5 layers even more function layer, thereby causes the complexity of its manufacturing process significantly to improve, and production efficiency and yield rate are difficult to be controlled.

Summary of the invention

In order to overcome the deficiency of existing lambda sensor manufacturing process complexity, the utility model provides a kind of tubular type double cell molded breadth domain oxygen sensor.

The technical scheme that its technical matters that solves the utility model adopts is: a kind of tubular type double cell molded breadth domain oxygen sensor; it comprises interior tubular zirconium-oxide; external oxidation zirconium pipe; heating rod and closed loop controller; the inside surface of the outside surface of tubular zirconium-oxide and external oxidation zirconium pipe coincide mutually in described; diffusion chamber is left on its top in tubular zirconium-oxide and external oxidation zirconium pipe stack back in described; the inside surface of tubular zirconium-oxide is provided with the reference gas passage in described; described reference gas passage is provided with platinum electrode and forms contrast electrode; the outside surface of tubular zirconium-oxide is provided with potential electrode in described; and interior electrode with the tangent formation pump of the inside surface battery pipe of external oxidation zirconium pipe; the outside surface of described external oxidation zirconium pipe is provided with pump battery pipe external electrode; the top of described external oxidation zirconium pipe has aperture; and being provided with the diffusion obstacle hole of filling diffusion layer, the skin of described external oxidation zirconium pipe is provided with porous external electrode protective seam.

According to another embodiment of the present utility model, further comprise described interior tubular zirconium-oxide as the concentration cell pipe, described external oxidation zirconium pipe is as limiting current pump battery pipe.

The beneficial effects of the utility model are, and are simple in structure with the tubular type double cell molded breadth domain oxygen sensor that the utility model is prepared, technology difficulty is little, can be completely achieved 15s with interior cold start-up requirement under the closely cooperating of built-in heating rod; Its output current characteristic is stable simultaneously; The tubular structure heat resistanceheat resistant that significantly the improved finished product performance of shaking in addition can prolong serviceable life of product, improves the stability in use of product.

Description of drawings

Below in conjunction with drawings and Examples the utility model is further specified.

Fig. 1 is a structural representation of the present utility model;

Fig. 2 is an enlarged diagram of the present utility model;

Fig. 3 is the utility model pump electric current output characteristic curve synoptic diagram.

1. interior tubular zirconium-oxides among the figure, 11. potential electrode, 12. contrast electrodes, 13. reference gas passages; 2. interior tubular zirconium-oxide, 21. interior electrodes, 22. external electrodes, 3. heating rod; 4. spread obstacle hole, 43. diffusion chambers, 5. external electrode protective seam, 6. closed loop controller.

Embodiment

A kind of tubular type double cell molded breadth domain oxygen sensor, tubular zirconium-oxide 1, potential electrode 11, contrast electrode 12, reference gas passage 13, interior tubular zirconium-oxide 2, interior electrode 21, external electrode 22, heating rod 3, diffusion obstacle hole 4, diffusion chamber 43, external electrode protective seam 5 and closed loop controller 6 in comprising.

As Fig. 1 is structural representation of the present utility model; a kind of tubular type double cell molded breadth domain oxygen sensor comprises interior tubular zirconium-oxide 1; interior tubular zirconium-oxide 2; heating rod 3 and closed loop controller 6; the inside surface of the outside surface of tubular zirconium-oxide 1 and external oxidation zirconium pipe 2 coincide mutually in described; diffusion chamber 43 is left on its top in tubular zirconium-oxide 1 and external oxidation zirconium pipe 2 stack backs in described; the inside surface of tubular zirconium-oxide 1 is provided with reference gas passage 13 in described; described reference gas passage 13 is provided with platinum electrode and forms contrast electrode 12; the outside surface of tubular zirconium-oxide 1 is provided with potential electrode 11 in described; and interior electrode 21 with the tangent formation pump of the inside surface battery pipe of external oxidation zirconium pipe 2; the outside surface of described external oxidation zirconium pipe 2 is provided with pump battery pipe external electrode 22; the top of described external oxidation zirconium pipe 2 has aperture; and being provided with the diffusion obstacle hole 4 of filling diffusion layer, the skin of described external oxidation zirconium pipe 2 is provided with porous external electrode protective seam 5.Tubular zirconium-oxide 1 is as the concentration cell pipe in described, and described external oxidation zirconium pipe 2 is as limiting current pump battery pipe.

As Fig. 2 is enlarged diagram of the present utility model, and this sensor is made of inside and outside two zirconia tube cores, and heating rod 3 separated settings.Interior tubular zirconium-oxide 1 is as the concentration cell pipe, and external oxidation zirconium pipe 2 is effective as limiting current pump battery.And the inside surface of the outside surface of inner concentration cell pipe 1 and external pump battery pipe 2 will coincide mutually, is beneficial to common burning or high temperature bonding.Want to reserve the diffusion chamber 43 of the gap of 0.1 ~ 2.5mm on its top after two other body stack as limiting current pump battery.The inside surface of interior tubular zirconium-oxide 1 with the contact of reference air, is provided with platinum electrode to form contrast electrode 12 by reference gas passage 13; At interior tubular zirconium-oxide 1 outside surface potential electrode 11 is set, and with the tangent interior electrode 21 that forms pump battery pipe again of the inner surface electrode layer of external oxidation zirconium pipe 2; The outside surface of tubular zirconium-oxide 2 is provided with pump battery pipe external electrode 22 outside.The top of external pump battery pipe 2 has aperture, and fills the diffusion layer formation diffusion obstacle hole 4 of certain pore size and porosity, and the oxygen molecule in the tail gas is diffused in the diffusion chamber 43 by this hole exactly and forms limiting current.By adjusting the porosity and the size of perforate aperture and diffusion layer, can obtain certain limiting current value.It is not contaminated with the protection external electrode that the outermost layer of external oxidation zirconium pipe 2 is provided with porous protective layer, guarantees to spread obstacle hole 4 simultaneously not by the foreign material congestion affects signal output characteristics in the tail gas.

At work, by the heating rod 3 of independent setting with the heating of position, double cell zirconium pipe top and maintain between 700 ~ 800 degree, externally the external electrode 22 of limiting current pump battery pipe 2 and interior electrode 21 two ends apply pump voltage and produce certain pump electric current by closed loop controller 6, make to produce voltage about 450mV between the contrast electrode 12 of concentration cell pipe 1 and the potential electrode 11.The pump electric current of Huo Deing is positive current in air-fuel ratio in greater than 1 scope like this, and along with air-fuel ratio increases and linear the increase; Equaling 1 o'clock pump electric current in air-fuel ratio is 0; Air-fuel ratio less than 1 scope in the pump electric current be negative value.This sensor can satisfy measurement and the control in the full air-fuel ratio scope equally thus.

Because lambda sensor of the present utility model is arranged well heater and double cell tube core branch, greatly reduces the technology difficulty of making; Itself be the tubulose symmetrical structure in addition, the heat resistanceheat resistant that can significantly the improve product integral body performance of shaking is for its serviceable life and stability provide good guarantee.

Specific embodiment:

The Zirconium oxide powder of doping 5mol yttria added 5% ~ 25% adhesive preparation and become idiosome material or slurry, tubular zirconium-oxide 1 and external oxidation zirconium pipe 2 idiosomes in being prepared into by compression-moulding methods or injection moulding method, formin embryonic tube body after degreasing.Control the external form of plain embryonic tube body by mould, the inside surface of the outside surface of tubular zirconium-oxide 1 plain embryo and external oxidation zirconium pipe 2 plain embryos can be fully identical in making.But the platinum electrode slurry that can use high temperature co-firing directly applies or is printed on the surfaces externally and internally of the plain embryo of two zirconium pipes, so that form the contrast electrode 12 of concentration cell pipe and the internal and external electrode of potential electrode 11 and pump battery behind the sintering; The top processing perforate of the plain embryo of externally big then zirconium pipe, and in the hole, inject the diffusion layer fluid slurry; Again the plain embryo of big or small body fully is superimposed, and the top can reserve the gap of 0.2 ~ 3mm, with czochralski method the porous protective layer fluid slurry for preparing be lifted surface at external electrode more afterwards; With putting into high temperature furnace after the surperficial slurry oven dry, between 1350 ~ 1600 degree, burnt altogether 1 ~ 5 hour, finally can prepare tubular type double cell molded breadth domain oxygen sensor of the present utility model.

Also can be with sintering 1 ~ 5 hour between 1350 ~ 1600 degree separately after the processing perforate earlier of the biscuit body after the degreasing, use the body surfaces externally and internally after the low temperature platinum electrode slurry is coated in sintering then, spend sintering 0.5 ~ 3 hour 900 ~ 1250, form required functional electrode layer, warm glass glaze fuses together two bodys under 700 ~ 1250 degree in using then, finishes the injection and the sintering of diffusion layer slurry in the diffusion hole of top simultaneously in above-mentioned two sintering stages.With plasma or thermal spray mode protective seam is sprayed on outermost surface more at last.

Simple in structure by the tubular type double cell molded breadth domain oxygen sensor that above step is prepared, technology difficulty is little, can be completely achieved 15s with interior cold start-up requirement under the closely cooperating of built-in heating rod; Its output current characteristic is stable simultaneously, and the pump electric current output characteristic curve of concrete sample is seen Fig. 3; In addition, the heat resistanceheat resistant that tubular structure has significantly the improved finished product performance of shaking can prolong serviceable life of product, improves the stability in use of product.

Claims

1. tubular type double cell molded breadth domain oxygen sensor; it is characterized in that; it comprises interior tubular zirconium-oxide (1); external oxidation zirconium pipe (2); heating rod (3) and closed loop controller (6); the inside surface of the outside surface of tubular zirconium-oxide (1) and external oxidation zirconium pipe (2) coincide mutually in described; diffusion chamber (43) is left in tubular zirconium-oxide (1) and external oxidation zirconium pipe (2) stack back in described on its top; the inside surface of tubular zirconium-oxide (1) is provided with reference gas passage (13) in described; described reference gas passage (13) is provided with platinum electrode and forms contrast electrode (12); the outside surface of tubular zirconium-oxide (1) is provided with potential electrode (11) in described; and interior electrode (21) with the tangent formation external oxidation of the inside surface zirconium pipe (2) of external oxidation zirconium pipe (2); the outside surface of described external oxidation zirconium pipe (2) is provided with the external electrode (22) of external oxidation zirconium pipe (2); the top of described external oxidation zirconium pipe (2) has aperture; and being provided with the diffusion obstacle hole (4) of filling diffusion layer, the skin of described external oxidation zirconium pipe (2) is provided with porous external electrode protective seam (5).

2. tubular type double cell molded breadth domain oxygen sensor according to claim 1 is characterized in that, described interior tubular zirconium-oxide (1) is as the concentration cell pipe, and described external oxidation zirconium pipe (2) is as limiting current pump battery pipe.