CN101315346A

CN101315346A - Gas sensor

Info

Publication number: CN101315346A
Application number: CNA2008100433727A
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: 2008-12-03
Anticipated expiration: 2028-05-16
Also published as: CN101315346B

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 a vitals in the engine management system as lambda sensor, and it is installed in the exhaust system of internal combustion engine, is used for perception waste gas concentration of oxygen, realizes the emission control to pollutant.Lambda sensor is installed in the engine's exhaust system, and working environment is more abominable, and temperature of being born in the lifetime and mechanical stress be all than higher, and therefore, reliable and stable Machine Design becomes the key that can the design of lambda sensor successful.

Existing Nernst galvanic cell type lambda sensor need 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 unanimity, for atmosphere, to guarantee exactly the atmosphere cleaning and can with fresh air generation gas exchange, otherwise, will cause the signal bias 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 is applied is cancelled, must guarantee that also encapsulant 254 still is in compressive state.Generally certain groove is set at sensor holder 253 outside surfaces; 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 of lifetime sealing.

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, to the control more complicated of the riveting technology of protective sleeve 251, to the dimension precision requirement of sensor holder 253 also than higher.

Need at high temperature work owing to be used for the ceramic body of perception oxygen concentration in the lambda sensor, how to be connected to become the problem that must solve in the design process of lambda sensor reliably realizing 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 lead 152.Electrode 151 on the refractory ceramics 150 is realized being connected with metal terminal 153, and two ceramic members 154 that have groove can cover metal terminal 153, thereby realizes metal terminal 153 and fixture 155 insulation.Fixture 155 has a U type 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 type structure struts, make two ceramic members 154 can separate certain distance each other, could smoothly the electrode on the refractory ceramics 150 151 be placed between the metal terminal 153 then, 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 is installed manufacturing cost on the one hand than higher, and part is many on the other hand, can't realize the miniaturization of dimensional structure.

The motorcycle annual production of China at present 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 clip, wire harness assembly;

Short sensor comprises metal sensor seat, ceramic sensing unit at least; Sensing unit 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 unit bottom places between the described contact spring, and contact disc directly contacts with contact spring, realizes being electrically connected;

The spring clip places in the wire harness assembly, is used for fixing spring base.

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 fixing the 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 on sensor holder and inwall that the reference side lining matches, the reference side lining is fixed in the sensor holder, and can prevent that seal from losing sealing effectiveness because of resilience takes place, and solved the sealing problem of gas sensor well.

Gas sensor of the present invention, on the one hand part is fewer, 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 clip;

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

Among the figure, 150 refractory ceramicss, 151 electrodes, 152 leads; 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 clips, 30 wire harness assemblies, 11 protective covers, 111 through holes; 112 extensions, 113 fixed parts, 114 umbrella portions, 12 sensor holders; 13 exhaust gas side linings, 14 seals, 16 reference side linings, 17 sensing units; 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 projectioies, 33 contact springs; 34 linings, 35 grommets, 36 leads.

Embodiment

As shown in Figure 8, gas sensor of the present invention comprises short sensor 10, spring clip 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 sensing unit 17;

Protective cover 11 comprises extension 112, fixed part 113, umbrella portion 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 portion 114; Described exhaust gas side lining 13 tops are provided with the conical surface that matches with umbrella portion 114.

Umbrella portion 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 are provided with seal 14, and seal 14 bottoms are provided with reference side lining 16.

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

Sensor holder 12 outside surfaces are provided with first mating surface 121, second mating surface, 122, the first mating surfaces 121 closely cooperate with the inside surface of spring clip 20, are used for fixing spring clip 20; 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 fixedlyed 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 of resilience takes place.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.

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, lead 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 lead 36; Every pair of contact spring 33 is fixed relative to one another, is used for fixing sensing unit 17; The bottom of sensing unit 17 is provided with contact disc 171, and contact disc 171 places between the contact spring 33, and the contact disc 171 of sensing unit 17 directly contacts with contact spring 33;

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

Protective sleeve 31 bottoms are provided with grommet 35, and the middle part is provided with the lead 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 lead 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 clip 20, and spring base 32 is fixed on the spring clip 20.

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

As shown in Figure 8, spring clip 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 second mating surface 122 and wire harness assembly 30, makes between short sensor 10 and the wire harness assembly 30 to fixedly connected; First mating surface 121 of sensor holder 12 closely cooperates with clip body 21 inside surfaces of spring clip 20, and spring clip 20 is fixedlyed 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 riveting or other method on sensor holder 12 and inwall that reference side lining 16 matches, reference side lining 16 is fixed in the sensor holder 12, and can prevent that seal 14 from losing sealing effectiveness because of resilience takes place, and solved the sealing problem of gas sensor well.

Claims

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

Short sensor (10) comprises metal sensor seat (12), ceramic sensing unit (17) at least; Sensing unit (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 unit (17) bottom places between the described contact spring (33), and contact disc (171) directly contacts with contact spring (33), realizes being electrically connected;

Spring clip (20) places in the wire harness assembly (30), is used for fixing spring base (32).

2, gas sensor according to claim 1 is characterized in that: 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.

3, gas sensor according to claim 2 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.

4, gas sensor according to claim 2 is characterized in that: 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 fixing reference side lining (16).

5, gas sensor according to claim 2 is characterized in that: described protective cover (11) is provided with umbrella portion (114), and described sensor holder (12) inside surface is provided with the taper surface that matches with umbrella portion (114); Described exhaust gas side lining (13) top is provided with the conical surface that matches with umbrella portion (114);

Exhaust gas side lining (13) is pressed on the umbrella portion (114) of protective cover (11) on the taper surface of sensor holder (12) inside surface.

6, gas sensor according to claim 2 is characterized in that: described seal (14) is for one or more.

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

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

8, gas sensor according to claim 1 is characterized in that: described spring clip (20) comprises clip body (21), and clip body (21) periphery is provided with plurality of elastic body (22).

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