CN101315346B

CN101315346B - Gas sensor

Info

Publication number: CN101315346B
Application number: CN 200810043372
Authority: CN
Inventors: 杨玉海; 张笑冬; 杨曾
Original assignee: United Automotive Electronic Systems Co Ltd
Current assignee: United Automotive Electronic Systems Co Ltd
Priority date: 2008-05-16
Filing date: 2008-05-16
Publication date: 2013-02-06
Anticipated expiration: 2028-05-16
Also published as: CN101315346A

Abstract

The invention discloses a gas sensor including a short sensor (10), a spring buckle (20) and a bunch assembly (30). A plurality of contact springs are arranged in a protective sleeve (31) of the bunch assembly (30), wherein each pair of the contact springs is mutually and relatively fixed; a sensing element (17) of the short sensor (10) is provided with contact disks (171), the contact disks (171) are arranged among the contact springs (33), and the contact disks (171) are directly contacted with the contact springs (33). The gas sensor has fewer parts, low installation and production cost, and great application value; and the gas sensor is easy to realize miniaturization of size and structure.

Description

Gas sensor

Technical field

The present invention relates to a kind of internal combustion engine electric parts, be specifically related to a kind of gas sensor.

Background technology

Gas sensor is vitals in the engine management system such as lambda sensor, and it is installed in the exhaust system of internal combustion engine, is used for the concentration of perception waste gas oxygen, realizes the emission control to pollutant.Lambda sensor is installed in the exhaust system of engine, and working environment is more abominable, and temperature and the mechanical stress of bearing in the lifetime are all higher, and therefore, reliable and stable Machine Design becomes the key of the design success of lambda sensor.

Existing Nernst galvanic cell type lambda sensor need to provide the reference cavity of a standard at interior electrode, is generally atmosphere.The partial pressure of oxygen of the canonical reference gas in the reference cavity must remain unanimously, for atmosphere, will guarantee that exactly the atmosphere cleaning also can exchange with fresh air generation gas, otherwise, will cause the signal skew of sensor.Way commonly used is with this reference cavity sealing, and is wired to cleaner zone, realizes and extraneous gas exchange by expanding with heat and contract with cold of gas.Form an annular seal space at sensor internal, must solve the sealing problem of annular seal space and waste gas.Way commonly used is to adopt resistant to elevated temperatures Inorganic Non-metallic Materials, and by certain structure with its compacting, thereby realize sealing.As shown in Figure 1, be applied to the axial force on the protective sleeve 251, can pass to high temperature sealing material 254 by ceramic chamber lining 252.Compacted encapsulant 254 can prevent effectively that exhaust gas leakage from arriving annular seal space.In order to guarantee the validity of sealing, must guarantee that the encapsulant 254 of lambda sensor can both guarantee sealing in lifetime.Therefore, after the axial force that applies is cancelled, must guarantee that also encapsulant 254 still is in compressive state.Generally at sensor holder 253 outside surfaces certain groove is set; by riveting protective sleeve 251; form projection at protective sleeve 251 inside surfaces; realization is fixed on protective sleeve 251 on the sensor holder 253; thereby guarantee that compacted encapsulant 254 can not fluff, satisfy the interior requirement to sealing of lifetime.

The cover 251 yet this way of realization needs protection, and in order to guarantee that encapsulant 254 all is in compressive state in lifetime is to the control more complicated of the riveting technique of protective sleeve 251, also higher to the dimension precision requirement of sensor holder 253.

Need at high temperature work owing to be used for the ceramic body of perception oxygen concentration in the lambda sensor, how will realize being connected to become reliably problem needing to overcome in the design process of lambda sensor between refractory ceramics and the metal terminal.

US Patent specification US006082175A (open day on July 4th, 2000) discloses a kind of gas sensor, and as shown in Figure 2, refractory ceramics 150 is realized electric and mechanical connection by metal terminal 153 and wire 152.Electrode 151 on the refractory ceramics 150 is realized being connected with metal terminal 153, is with reeded two ceramic members 154 metal terminal 153 can be covered, thereby realizes metal terminal 153 and fixture 155 insulation.Fixture 155 has a U-shaped structure, two ceramic members 154 can be clamped.Metal terminal 153 is when electrode 151 on the refractory ceramics 150 is connected, the oral area that needs to adopt special tooling will have the fixture 155 of U-shaped structure struts, so that two ceramic members 154 can separate certain distance each other, then could smoothly the electrode 151 on the refractory ceramics 150 be placed between the metal terminal 153, after finishing above-mentioned action, make special tooling withdraw from the oral area of fixture 155, fixture 155 is with two ceramic members 154 interlinear notes firmly, be fixed in two metal terminals 153 on the ceramic member 154 and be pressed in tightly on the electrode 151 of refractory ceramics 150, realize electric and mechanical connection.

The gas sensor of this structure, it is higher that manufacturing cost is installed on the one hand, and part comparison is many on the other hand, can't realize the miniaturization of dimensional structure.

The at present motorcycle annual production of China surpasses 2,000 ten thousand, and major part still adopts carburetor structure, and its pollution on the environment can not be ignored, and it is imperative that the discharging of motorcycle is controlled.Lambda sensor also is essential as a vital part in the engine management system for the motorcycle management system.Because motorcycle industry is to the susceptibility of price and have that himself is exclusive, develops the tight demand that a lambda sensor becomes market for motorcycle specially.

Summary of the invention

The technical problem to be solved in the present invention provides a kind of gas sensor, and it can satisfy the miniaturization requirement, and cost is low.

For solving the problems of the technologies described above, the technical solution of gas sensor of the present invention is:

Comprise short sensor, spring hoop, wire harness assembly;

Short sensor comprises metal sensor seat, ceramic sensor unit at least; Sensing element places the central authorities of sensor holder;

Wire harness assembly comprises metal protection protector, ceramics springs seat, contact spring at least; Be provided with somely to contact spring in the protective sleeve, contact spring is fixed on the spring base, and every pair of contact spring is fixed relative to one another;

The contact disc of sensing element bottom places between the described contact spring, and contact disc directly contacts with contact spring, realizes electrical connection;

Spring hoop places in the wire harness assembly, is used for the fixing spring seat.

The inwall that described sensor holder matches with the reference side lining is provided with and is no less than two salient points, is used for fixed reference side lining.

The technique effect that the present invention can reach is:

Gas sensor of the present invention adopts simple machinery assembling to realize connecting between its protective cover and the sensor holder, avoided traditional laser bonding or flanging process, has greatly reduced the installation manufacturing cost.

The present invention processes a plurality of salient points by riveting or other method at the inwall that sensor holder matches with the reference side lining, the reference side lining is fixed in the sensor holder, and can prevent that seal from losing sealing effectiveness because resilience occurs, and solved the sealing problem of gas sensor well.

Gas sensor of the present invention, on the one hand part comparison is few, and it is lower that manufacturing cost is installed on the other hand, and be easy to realize the miniaturization of dimensional structure, has great using value.

Description of drawings

The present invention is further detailed explanation below in conjunction with the drawings and specific embodiments:

Fig. 1 is the structural representation of prior art lambda sensor;

The structural representation of Fig. 2 prior art gas sensor;

Fig. 3 is the structural representation of short sensor;

Fig. 4 is the cut-open view of short sensor;

Fig. 5 is the structural representation of wire harness assembly;

Fig. 6 is the synoptic diagram of the wire harness assembly after spring base is taken out from protective sleeve;

Fig. 7 is the synoptic diagram of spring hoop;

Fig. 8 is the structural representation of gas sensor of the present invention.

Among the figure, 150 refractory ceramicss, 151 electrodes, 152 wires; 153 metal terminals, 154 ceramic members, 155 fixtures, 251 protective sleeves; 252 ceramic chamber linings, 253 sensor holders, 254 encapsulants, 10 short sensors; 20 spring hoops, 30 wire harness assemblies, 11 protective covers, 111 through holes; 112 extensions, 113 fixed parts, 114 umbrella sections, 12 sensor holders; 13 exhaust gas side linings, 14 seals, 16 reference side linings, 17 sensing elements; 171 contact discs, 121 first mating surfaces; 122 second mating surfaces, 1211 salient points; 21 clip bodies, 22 elastic bodys, 31 protective sleeves; 32 spring bases, 321 projections, 33 contact springs; 34 linings, 35 grommets, 36 wires.

Embodiment

As shown in Figure 8, gas sensor of the present invention comprises short sensor 10, spring hoop 20, wire harness assembly 30;

As shown in Figure 3, Figure 4, short sensor 10 comprises protective cover 11, metal sensor seat 12, exhaust gas side lining 13, seal 14, reference side lining 16, ceramic sensor unit 17;

Protective cover 11 comprises extension 112, fixed part 113, umbrella section 114, and the external diameter of fixed part 113 is interference fit greater than extension 112 between fixed part 113 outside surfaces and sensor holder 12 top inner surface.

Protective cover 11 is fixed in the top of sensor holder 12 by fixed part 113, and the extension 112 of protective cover 11 stretches out from the top of sensor holder 12, and extension 112 is provided with some through holes 111.Because the external diameter of extension 112 less than fixed part 113, therefore in assembling process, can stretch out sensor holder 12 with protective cover 11 at an easy rate.

Sensor holder 12 inside surfaces are provided with the taper surface that matches with umbrella section 114; Described exhaust gas side lining 13 tops are provided with the conical surface that matches with umbrella section 114.

Umbrella section 114 with protective cover 11 is pressed on the taper surface of sensor holder 12 inside surfaces by exhaust gas side lining 13, can make protective cover 11 and sensor holder 12 further fixing.

Exhaust gas side lining 13 bottoms arrange seal 14, and seal 14 bottoms arrange reference side lining 16.

Sensing element 17 stretches into sensor holder 12 from the bottom, pass successively reference side lining 16, seal 14, exhaust gas side lining 13, places the central authorities of sensor holder 12, and the top of sensing element 17 is stretched in the cavity of protective cover 11.The bottom of sensing element 17 is provided with some contact discs 171, contact disc 171 by with being connected of contact spring 33, the signal that gathers is transferred to ECU (Electrical Control Unit).

Sensor holder 12 outside surfaces are provided with the first mating surface 121, the second mating surface 122, the first mating surfaces 121 closely cooperate with the inside surface of spring hoop 20, are used for fixing spring clip 20; The second mating surface 122 closely cooperates with the inside surface of the protective sleeve 31 of wire harness assembly 30, and sensor holder 12 is fixedly connected with protective sleeve 31.

The inwall that sensor holder 12 matches with reference side lining 16 is provided with a plurality of salient points 1211, and salient point 1211 can be fixed in the sensor holder 12 reference side lining 16, and can prevent that seal 14 from losing sealing effectiveness because resilience occurs.Salient point 1211 is generally three to six.

Seal 14 adopts elastic powdery high temperature sealing material to make; For the enhanced leaktightness effect, can adopt a plurality of seals 14, embodiment shown in Figure 4 has adopted three seals 14.

Such as Fig. 5, shown in Figure 6, wire harness assembly 30 comprises metal protection protector 31, ceramics springs seat 32, contact spring 33, lining 34, grommet 35, wire 36;

Be provided with somely to contact spring 33 in the protective sleeve 31, contact spring 33 1 ends are fixed on the spring base 32, and the other end is connected with an end of wire 36; Every pair of contact spring 33 is fixed relative to one another, is used for fixedly sensing element 17; The bottom of sensing element 17 is provided with contact disc 171, and contact disc 171 places between the contact spring 33, and the contact disc 171 of sensing element 17 directly contacts with contact spring 33;

Contact spring 33 can adopt the high temperature resistant stainless steel material, makes such as Inconel.

Protective sleeve 31 bottoms are provided with grommet 35, and the middle part is provided with the wire 36 that lining 34, one ends are connected with contact spring 33 and passes lining 34 and grommet 35, stretches out protective sleeve 31.Lining 34 can be separated from each other wire 36.

Spring base 32 can be up and down in protective sleeve 31.

Spring base 32 outsides are provided with projection 321, and projection 321 can closely cooperate with the inside surface of spring hoop 20, and spring base 32 is fixed on the spring hoop 20.

As shown in Figure 7, spring hoop 20 comprises clip body 21, and clip body 21 peripheries are provided with some elastic bodys 22, and clip body 21 is fixed in the inwall of protective sleeve 31 by elastic body 22.

As shown in Figure 8, spring hoop 20 places in the wire harness assembly 30, and the sensor holder 12 of short sensor 10 is by closely cooperating between the inside surface of the protective sleeve 31 of the second mating surface 122 and wire harness assembly 30, makes between short sensor 10 and the wire harness assembly 30 to be fixedly connected with; The first mating surface 121 of sensor holder 12 closely cooperates with clip body 21 inside surfaces of spring hoop 20, and spring hoop 20 is fixedly connected with the sensor holder 12 of short sensor 10.

Gas sensor of the present invention adopts simple machinery assembling to realize connecting between its protective cover 11 and the sensor holder 12, avoided traditional laser bonding or flanging process, has greatly reduced the installation manufacturing cost.

The present invention processes a plurality of salient points 1211 by the inwall that riveting or other method match with reference side lining 16 at sensor holder 12, reference side lining 16 is fixed in the sensor holder 12, and can prevent that seal 14 from losing sealing effectiveness because resilience occurs, and solved the sealing problem of gas sensor well.

Claims

1. a gas sensor is characterized in that: comprise short sensor (10), spring hoop (20), wire harness assembly (30);

Short sensor (10) comprises metal sensor seat (12), ceramic sensor unit (17) at least; Sensing element (17) places the central authorities of sensor holder (12);

Wire harness assembly (30) comprises metal protection protector (31), ceramics springs seat (32), contact spring (33) at least; Be provided with somely to contact spring (33) in the protective sleeve (31), contact spring (33) is fixed on the spring base (32), and every pair of contact spring (33) is fixed relative to one another;

The contact disc (171) of sensing element (17) bottom places between the described contact spring (33), and contact disc (171) directly contacts with contact spring (33), realizes electrical connection;

Spring hoop (20) places in the wire harness assembly (30), is used for fixing spring seat (32);

Described short sensor (10) also comprises protective cover (11), exhaust gas side lining (13), seal (14), reference side lining (16); Protective cover (11) is fixed in the top of sensor holder (12); Be provided with exhaust gas side lining (13), seal (14), reference side lining (16) in the sensor holder (12); Described seal (14) places between exhaust gas side lining (13) and the reference side lining (16) and by exhaust gas side lining (13) and reference side lining (16) and compresses;

The inwall that described sensor holder (12) matches with reference side lining (16) is provided with and is no less than two salient points (1211), is used for fixed reference side lining (16);

Described protective cover (11) is provided with umbrella section (114), and described sensor holder (12) inside surface is provided with the taper surface that matches with umbrella section (114); Described exhaust gas side lining (13) top is provided with the conical surface that matches with umbrella section (114); Exhaust gas side lining (13) is pressed on the umbrella section (114) of protective cover (11) on the taper surface of sensor holder (12) inside surface.

2. gas sensor according to claim 1, it is characterized in that: described protective cover (11) comprises extension (112), fixed part (113), and protective cover (11) is fixed in the top of sensor holder (12) by fixed part (113);

The external diameter of the fixed part (113) of described protective cover (11) is interference fit greater than extension (112) between fixed part (113) outside surface and sensor holder (12) top inner surface.

3. gas sensor according to claim 1 is characterized in that: described seal (14) is for one or more.

4. gas sensor according to claim 1, it is characterized in that: described wire harness assembly (30) also comprises lining (34), grommet (35), wire (36);

Described protective sleeve (31) bottom is provided with grommet (35); the middle part is provided with lining (34); the wire (36) that one end is connected with described contact spring (33) passes lining (34) and grommet (35), stretches out protective sleeve (31).

5. gas sensor according to claim 1, it is characterized in that: described spring hoop (20) comprises clip body (21), clip body (21) periphery is provided with some elastic bodys (22).

6. gas sensor according to claim 1, it is characterized in that: described spring base (32) is provided with projection (321), and projection (321) closely cooperates with the inside surface of spring hoop (20) after the assembling.