KR101546856B1 - Oxygen Sensor For Internal Combustion Engine - Google Patents

Abstract

An embodiment of the present invention relates to an oxygen sensor for an internal combustion engine. More particularly, to an oxygen sensor for measuring an exhaust gas air-fuel ratio of an internal combustion engine.
The oxygen sensor for an internal combustion engine according to the present embodiment has a structure in which a nonvolatile memory is mounted instead of a trimming resistor, thereby omitting a laser cutting process for correcting a production error occurring in the production process of a sensing device, The cost can be reduced.

Description

TECHNICAL FIELD [0001] The present invention relates to an oxygen sensor for an internal combustion engine,

An embodiment of the present invention relates to an oxygen sensor for an internal combustion engine. More particularly, to an oxygen sensor for measuring an exhaust gas air-fuel ratio of an internal combustion engine.

The contents described in this section merely provide background information on the embodiment of the present invention and do not constitute the prior art.

Today, automobiles are equipped with electronic control units (ECUs) and three-way catalysts in order to cope with the reduction of harmful exhaust gases emitted from internal combustion engines and exhaust gas regulations.

The electronic control unit detects the state of the engine such as the rotational speed of the engine, the intake air amount, the cooling water temperature, and the intake air temperature through various sensors so as to supply the mixer required by the internal combustion engine, Precisely controls the supply of the mixer most suitable for the condition.

The electronic control unit of the automobile includes various sensors that perform various functions in order to detect the state of the internal combustion engine. Among these various sensors, an oxygen sensor for controlling the air-fuel ratio of an automobile using gasoline, The exhaust gas purifying apparatus according to the present invention performs the function of detecting the oxygen concentration in the exhaust gas.

On the other hand, the three-way catalyst is an apparatus for purifying the exhaust gas. In order to effectively purify the exhaust gas by using the three-way catalyst, the air-fuel ratio should be controlled to the stoichiometric air-fuel ratio. However, since the range of the air-fuel ratio at which CO, HC, and NOx can be completely cleaned (the catalytic converter window) is extremely narrow, the open loop control can not satisfy this requirement.

Therefore, in order to realize the air-fuel ratio required by the three-way catalyst, an oxygen sensor is installed in the exhaust pipe to detect whether the air-fuel ratio in the exhaust gas is rich or lean with respect to the stoichiometric air- Needs to be.

A conventional conventional oxygen sensor is shown in Figs. 1, 2 and 3. Fig. The conventional oxygen sensor 10 is mounted directly on the exhaust pipe 3 mainly around a high temperature engine to measure the oxygen concentration in the exhaust gas flowing inside the exhaust pipe 3. The sensor sensing unit 12 includes a sensing element 17 made of zirconia-based solid electrolyte and a protective cover 11 for protecting the sensing element 17. A sensing hole 19 is formed in the protective cover 11 so that the sensing element 17 can measure the exhaust gas that has passed through the sensing hole 19. Therefore, the sensing element 17 measures the voltage through the flow of electrons generated by the movement of oxygen ions due to the oxygen concentration difference between the atmosphere side and the exhaust gas side.

According to the embodiment, the main body portion 14 of the oxygen sensor 10 is provided with an opening through which the reference air at the atmosphere side can be introduced, and the oxygen partial pressure of the reference air is adjusted by the water or oil component flowing from the outside into the opening Breathable parts are mounted in order to prevent the problem from occurring in normal oxygen amount detection.

A hexagonal threaded portion 13 may be formed between the body portion 14 and the protective cover 11. The hexagonal screw portion 13 serves to fix the oxygen sensor 10 to the exhaust gas pipe 3.

The signal transmission wire 15 is provided to transmit the air-fuel ratio signal measured by the sensing element 17 of the sensor sensing unit 12, and one side thereof is electrically connected to the sensor sensing unit 12 to receive the air- , And the other side is connected to the signal transmission connector 16.

The signal transfer connector 16 is electrically connected to a harness electrically connected to the electronic controller and transmits the air-fuel ratio signal to the electronic controller.

On the other hand, the sensing element 17, which is a core component of the oxygen sensor 10, has a production error that is already latent in the production process. There is also an error in the air-fuel ratio signal measured by the sensing element 17 due to such a production error. Therefore, in order to correct the error of the air-fuel ratio signal, a trimming resistor 20, which is a component for correcting the production error, is provided in the signal transfer connector 16. The resistance value of the trimming resistor 20 is adjusted, .

However, in order to adjust the resistance value of the trimming resistor 20, a laser cutting process is generally performed. Since this laser cutting process must be performed very precisely, there is a problem of increasing the manufacturing time and production cost of the oxygen sensor 10 have.

An object of the present invention is to provide an oxygen sensor for an internal combustion engine having a new structure for reducing an air-fuel ratio signal error due to a manufacturing error of a sensing element.

The technical object of the present invention is not limited to the above-mentioned technical objects and other technical objects which are not mentioned can be clearly understood by those skilled in the art from the following description will be.

The oxygen sensor for an internal combustion engine according to an embodiment of the present invention may include a sensor sensing part protruding into an exhaust pipe of the internal combustion engine to measure the air-fuel ratio to measure the air-fuel ratio of the exhaust gas of the internal combustion engine.

Further, a signal transmission wire electrically connected to the sensor sensing unit and transmitting an air-fuel ratio signal may be included.

And a signal transmission connector electrically connected to the signal transmission wire for transmitting the air-fuel ratio signal to the electronic controller.

Meanwhile, the signal transmission connector may be equipped with a nonvolatile memory for correcting an error of the air-fuel ratio signal.

According to an embodiment, the non-volatile memory may comprise an EEPROM.

The non-volatile memory may interact with the electronic controller to correct the air-fuel ratio signal error.

The correction value for correcting the error of the air-fuel ratio signal may be stored in the non-volatile memory by computer programming.

The electronic controller may read the correction value and correct an error of the air-fuel ratio signal.

The signal transfer connector has a plurality of terminal pins, and the nonvolatile memory may be installed in any one of the plurality of terminal pins.

The oxygen sensor for an internal combustion engine according to another embodiment of the present invention may include a sensor sensing unit for measuring the air-fuel ratio of the exhaust gas of the internal combustion engine to generate an air-fuel ratio signal.

Also, it may include a signal transmission wire electrically connected to the sensor sensing unit to transmit the air-fuel ratio signal.

Further, it may include a memory for storing a correction value for correcting the error of the air-fuel ratio signal.

And a signal transmission connector electrically connected to the signal transmission wire and transmitting the air-fuel ratio signal and the correction value to an electronic controller.

According to the embodiment, the memory may be installed inside the signal transmission connector.

According to an embodiment, the memory may comprise a non-volatile memory.

As described above, the oxygen sensor for an internal combustion engine according to the present embodiment adopts a structure in which a nonvolatile memory is mounted instead of a trimming resistor, thereby omitting a laser cutting process for correcting a production error occurring in the production process of a sensing device, The manufacturing time and production cost of the apparatus can be reduced.

In addition, the effects of the present invention have various effects such as excellent durability according to the embodiments, and such effects can be clearly confirmed in the description of the embodiments described later.

1 is a view showing a conventional oxygen sensor in general.
2 is a cross-sectional view of the oxygen sensor shown in Fig.
Fig. 3 shows a signal transmission connector of the oxygen sensor shown in Fig.
4 is a view showing an oxygen sensor according to an embodiment of the present invention.
5 shows a method of manufacturing an oxygen sensor according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described in detail with reference to exemplary drawings. However, this is not intended to limit the scope of the invention.

It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In addition, the size and shape of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, terms specifically defined in consideration of the constitution and operation of the present invention are only for explaining the embodiments of the present invention, and do not limit the scope of the present invention.

4 is a view showing an oxygen sensor for an internal combustion engine according to an embodiment of the present invention.

An oxygen sensor 100 for an internal combustion engine according to an embodiment of the present invention is for measuring the air-fuel ratio of an exhaust gas of an internal combustion engine (not shown) installed in a vehicle or the like and is provided with an air- A sensor sensing unit 120 for measuring the sensor; A signal transmission wire 150 electrically connected to the sensor sensing unit 120 and transmitting an air-fuel ratio signal; And a signal transmission connector 160 electrically connected to the signal transmission wire 150 and transmitting the air-fuel ratio signal to the electronic controller.

Here, the signal transfer connector 160 may be equipped with a nonvolatile memory 200 for correcting an error of the air-fuel ratio signal.

The oxygen sensor 100 is mounted on an exhaust pipe 3 through which exhaust gas combusted in an internal combustion engine (not shown) flows.

The sensor sensing unit 120 is provided to measure the air-fuel ratio by projecting into the exhaust pipe 3 of the internal combustion engine. The structure of the sensor sensing unit 120 is the same as that of the conventional sensor shown in Fig. That is, the sensor sensing unit 120 may include a hexagonal screw portion 130 and a body portion 140 as described above.

The sensor sensing unit 120 includes a sensing element made of zirconia and a protective cover 110 for protecting the sensing element.

The sensing element in the oxygen sensor 100 measures the voltage through the flow of electrons generated by the movement of oxygen ions due to the oxygen concentration difference between the atmosphere side and the exhaust gas side. That is, the sensing element of the zirconia material of the sensor sensing unit 120 generates an electromotive force by the difference in partial pressure between the exhaust gas side air flowing in the exhaust pipe 3 and the reference air.

The signal transmission wire 150 is provided to transmit the air-fuel ratio signal, which is electrically connected to the sensor sensing unit 120 and measured by the sensing element of the sensor sensing unit 120. The air-fuel ratio signal is transmitted to an electronic controller (not shown) that controls the operation of the internal combustion engine via the signal transfer connector 160. The electronic controller controls the air-fuel ratio of the air-fuel mixture injected into the internal combustion engine close to the stoichiometric air-fuel ratio by feedback-controlling the fuel injection device mounted on the internal combustion engine using the measured air-

The signal transmission connector 160 is electrically connected to a harness electrically connected to the electronic controller. In general, the signal transmission connector 160 is located at a sufficient distance from the exhaust pipe 3 in the engine room of the vehicle in which the internal combustion engine is installed, so that heat damage by the hot exhaust pipe 3 can be prevented.

Hereinafter, the operational relationship between the nonvolatile memory 200 of the signal transfer connector 160 and the electronic controller will be described in detail.

One of the features of one embodiment of the present invention is that the non-volatile memory 200 can be mounted on the oxygen sensor 100. [ According to an embodiment, non-volatile memory 200 may be mounted within signal transfer connector 160. The non-volatile memory 200 may include an EEPROM according to an embodiment. The signal transfer connector 160 may have a plurality of terminal pins 161 and the nonvolatile memory 200 may be installed in any one of the plurality of terminal pins 161. [ That is, the plurality of terminal pins 161 may be connected to a harness electrically connected to the electronic controller, and may transmit the air-fuel ratio signal to the electronic controller through the harness. One of the plurality of terminal pins 161 may be a connection line through which a correction value stored in the nonvolatile memory 200 is transmitted. Therefore, the correction value of the air-fuel ratio signal stored in the nonvolatile memory 200 can be transmitted to the electronic controller.

The non-volatile memory 200 may interact with the electronic controller to correct the air-fuel ratio signal error. That is, the manufacturer can test whether the air-fuel ratio signal of the oxygen sensor 100 is correct after producing the oxygen sensor 100 for the internal combustion engine. The sensing element included in the sensor sensing unit 120 may have an error value that is originally latent in the manufacturing process. Therefore, the air-fuel ratio signal output by the oxygen sensor 100 may be inaccurate.

The manufacturer can confirm the correction value by comparing the correct reference value of the air-fuel ratio signal with the air-fuel ratio signal value including the error through the above-described test. If the correct reference value is 10, but the air-fuel ratio signal is 8, then a correction value of +2 is required. Therefore, the manufacturer can determine +2 as the correction value in this case.

After confirming the correction value, the manufacturer can store the information indicating the correction value in the nonvolatile memory 200. [ In the non-volatile memory 200, a correction value for correcting an error of the air-fuel ratio signal by computer programming can be stored. That is, the manufacturer may store information indicating the correction value determined by computer programming in the nonvolatile memory 200. [ The correction value may be stored in the nonvolatile memory 200 before or after mounting the nonvolatile memory 200 to the oxygen sensor 100. [

The electronic controller can correct the error of the air-fuel ratio signal by reading the correction value. That is, the electronic controller receives the information including the air-fuel ratio signal as well as the correction value from the signal transmission connector 160, thereby correcting the error of the air-fuel ratio signal and outputting the corrected air-fuel ratio signal having the corrected value as the resultant value.

The oxygen sensor 100 for an internal combustion engine according to another embodiment of the present invention includes a sensor sensing unit 120 for measuring an air-fuel ratio of an exhaust gas of an internal combustion engine and generating an air-fuel ratio signal; A signal transmission wire 150 electrically connected to the sensor sensing unit 120 to transmit the air-fuel ratio signal; A memory (200) for storing a correction value for correcting an error of the air / fuel ratio signal; And a signal transmission connector 160 electrically connected to the signal transmission wire 150 and transmitting the air-fuel ratio signal and the correction value to an electronic controller.

The memory 200 may be installed inside the signal transfer connector 160 according to an embodiment of the present invention.

In addition, the memory 200 may include a non-volatile memory.

5 shows a method of manufacturing an oxygen sensor according to an embodiment of the present invention.

Meanwhile, a method of manufacturing an oxygen sensor for an internal combustion engine for measuring an air-fuel ratio of an exhaust gas of an internal combustion engine according to another embodiment of the present invention includes a sensor sensing unit including a sensing element for measuring oxygen concentration of the exhaust gas, A first step (S100) of electrically connecting a signal transmission wire for transmitting the air-fuel ratio signal measured by the air-fuel ratio sensor to a signal transmission connector for transmitting the air-fuel ratio signal to the electronic controller; A second step (S200) of providing a nonvolatile memory (200) for correcting an error of the air-fuel ratio signal to the signal transfer connector; And a third step (S300) of storing a correction value for correcting the error of the air-fuel ratio signal in the non-volatile memory (200).

The operator can carry out a test for measuring the air-fuel ratio of the exhaust gas after installing the non-volatile memory in the signal transfer connector or before installing the sensor, and it is also possible to perform calibration by correcting the error of the air- The value can be confirmed. The correction value thus determined can be stored in the nonvolatile memory so that the signal transmission connector can transmit not only the air-fuel ratio signal but also the correction value described above to the electronic controller. The electronic controller can correct the error of the air-fuel ratio signal transmitted from the signal transmission connector with the received correction value. As a result, it is possible to utilize the air-fuel ratio signal having an accurate corrected value as the resultant value.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention.

Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

100: oxygen sensor for internal combustion engine 110: protective cover
120: sensor sensing unit 130: hexagonal screw
140: main body part 150: signal transmission wire
160: signal transmission connector 200: nonvolatile memory

Claims (10)

A sensor sensing part including a sensing element for measuring an air-fuel ratio of the exhaust gas of the internal combustion engine and projecting into an exhaust pipe of the internal combustion engine to measure an air-fuel ratio;
A signal transmission wire electrically connected to the sensor sensing unit and transmitting the measured air-fuel ratio signal;
A signal transmission connector electrically connected to the signal transmission wire and including a plurality of terminal pins for being electrically connected to the electronic controller for transmitting the air-fuel ratio signal to the electronic controller;
Wherein the signal transmission connector is equipped with a nonvolatile memory electrically connected to at least one terminal pin of the plurality of terminal pins and for correcting an error of the air-fuel ratio signal caused by a production error of the sensing element Oxygen sensor for internal combustion engine. The method according to claim 1,
Wherein the non-volatile memory includes an EEPROM. The method according to claim 1,
Wherein the non-volatile memory interacts with the electronic controller to correct the air-fuel ratio signal error. The method according to claim 1,
Wherein a correction value for correcting an error of the air-fuel ratio signal is stored in the nonvolatile memory, and the correction value is determined by comparing a measurement result of a measurement test with respect to the sensing element to a reference value. . 5. The method of claim 4,
Wherein the electronic controller reads the correction value and corrects the error of the air-fuel ratio signal. delete A sensor sensing unit including a sensing element for measuring an air-fuel ratio of exhaust gas of an internal combustion engine and generating an air-fuel ratio signal;
A signal transmission wire electrically connected to the sensor sensing unit and transmitting the air-fuel ratio signal;
A memory for storing a correction value for correcting an error of the air-fuel ratio signal caused by a production error of the sensing element; And
A signal transmission connector electrically connected to the signal transmission wire and transmitting the air-fuel ratio signal and the correction value to an electronic controller;
And an oxygen sensor. 8. The method of claim 7,
Wherein the memory is installed inside the signal transmission connector. 8. The method of claim 7,
Wherein the memory comprises a non-volatile memory. A method of manufacturing an oxygen sensor for an internal combustion engine for measuring an air-fuel ratio of an exhaust gas of an internal combustion engine,
A signal transmission wire for transmitting the air-fuel ratio signal measured by the sensor sensor and a signal transmission connector for transmitting the air-fuel ratio signal to the electronic controller are electrically connected to each other A first step;
A second step of providing a non-volatile memory for correcting an error of the air-fuel ratio signal to the signal transfer connector; And
Fuel ratio signal to the non-volatile memory by performing a measurement test on the sensing element, comparing the measured result value with a reference value to determine a correction value for correcting an error of the air-fuel ratio signal due to a production error of the sensing element, A third step of storing a value;
Wherein the oxygen sensor has an oxygen sensor.

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