ES2685078T3 - Structure for fixing an exhaust gas sensor - Google Patents

Abstract

A structure in a cylinder head (31) of an internal combustion engine (2) for fixing an exhaust gas sensor (62), where an exhaust port (40) has been provided between an outlet port (43) and a fixing portion (74) of an exhaust pipe, the outlet port (43) being an upstream inlet to the exhaust port (40), the fixing portion (74) of the exhaust pipe being a Exhaust port outlet, characterized in that an exhaust gas collection slot (64) extending in a flow direction of an exhaust gas has been provided, in an internal wall of the exhaust port (40), having been provided the exhaust gas collection slot (64) on an inner wall surface (77) of the inner side of the curved exhaust port, and the exhaust gas sensor (62) being fixed thereto, and the sensor ( 62) of exhaust gases fixed in a way that a front end portion of the gas sensor (62) The exhaust is located at the rear of the exhaust gas collection slot (64).

Description

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

DESCRIPTION

Structure for fixing an exhaust gas sensor.

The present invention relates to a structure for fixing an exhaust gas sensor of the type defined in the preamble of claim 1.

It is desired that an exhaust gas sensor has no heater structure (an oxygen sensor without a heater) has to be configured so as to be able to ensure a temperature necessary for its reaction as soon as possible, and thus Start detecting oxygen with the highest accuracy as soon as possible. On the other hand, because the exhaust gas sensor is exposed to exhaust gases at temperature during operation, a problem to be solved is to increase the accuracy of the oxygen detection while ensuring the heat resistance of the exhaust gas sensor.

Examples of the prior art include an example in which a part of the exhaust pipe is divided into two steps. One of the two steps serves as the main discharge passage of the exhaust gases, which has a larger cross-section, while the other of the two steps serves as the fixing step of the exhaust gas sensor, having a smaller cross-section. . The main discharge passage of the exhaust gases is provided with a flow quantity control valve. The control is carried out by using a controller unit and an actuator in a way that: until the temperature of an exhaust gas sensor element reaches an activation temperature, the flow quantity control valve is closed to increase the amount of exhaust gases flowing to the fixing step of the exhaust gas sensor, and thereby raising the temperature of the element; once the temperature of the exhaust gas sensor element turns out to be equal to or greater than a temperature that thermally deteriorates the element, the flow quantity control valve opens to reduce the amount of the exhaust gases flowing to the fixing step of the exhaust gas sensor and thereby preventing the temperature rise of the element (see Japanese Utility Model publication No. Hei 1-43461, for example).

JP H11 200913 A discloses a structure of the initially defined type, wherein an exhaust gas sensor is fixed such that the part thereof that is in direct contact with the exhaust gases extends completely through a port exhaust in the cylinder head.

An object of the present invention is to provide means that allow an exhaust gas sensor having no heater structure to initiate the detection of oxygen with a higher precision as soon as possible after an engine has been started. of internal combustion, without relying on the control of the amount of flow of the exhaust gases, and increasing the accuracy of the oxygen detection while ensuring the heat resistance of the exhaust gas sensor.

The present invention has achieved the object described above, and a first aspect of the invention relates to a structure for fixing an exhaust gas sensor having the characteristics defined in claim .1

A second aspect of the invention consists in the structure for fixing an exhaust gas sensor according to the first aspect, characterized in that a base of a cover (71) for protecting the element of the exhaust gas sensor (62) is located in an orifice (63) for fixing the exhaust gas sensor, and a front end portion of the element protection cover is located in a gas passage of the exhaust port (40).

A third aspect of the invention is the structure for fixing an exhaust gas sensor according to the second aspect, characterized in that the configuration of a passage of the exhaust port (40) is curved from the outlet port (43), which is an opening and closing port of an exhaust valve (44), towards the fixing portion (74) of the exhaust pipe in a side view (Figure 3) extending in the direction of an axial line (C ) of the cylinder, and the shape of the passage of the exhaust port (40) is also curved in the direction from left to right when viewed in the direction of the axial line (C) of the cylinder (Figure 4).

A fourth aspect of the invention is the structure for fixing an exhaust gas sensor of any one of the first and second aspects, characterized in that an exhaust gas collection slot (64) has been formed, which is extends upstream and downstream of a clamping portion (79) to hold a valve guide (45) (one close to a neck portion (80) of the exhaust port), which has been provided in the exhaust port ( 40).

A fifth aspect of the invention is the structure for fixing an exhaust gas sensor of the fourth aspect, characterized in that the exhaust gas collection slot (64) is formed in such a way that a termination portion (75) imaginary extended backwards, which has been formed by extending a wall surface of the exhaust gas collection slot (64) in the downstream direction, almost coincides with an oxygen concentration detector (69) of the gas sensor (62) escape

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

A sixth aspect of the invention is the structure for fixing an exhaust gas sensor of the fifth aspect, characterized in that, when the internal combustion engine (2) is started, the internal combustion engine (2) is controlled by controlling an ignition time and a fuel injection amount with a constant maintained amount of intake air.

A seventh aspect of the invention is the structure for fixing an exhaust gas sensor of any one of the fourth and fifth aspects, characterized in that the exhaust gas sensor (62) is located in the groove in a manner that the exhaust gas sensor (62) projects from a downstream side to an upstream side with respect to a central line (E) of the exhaust port passage (40). An eighth aspect of the invention is the structure for fixing an exhaust gas sensor of the seventh aspect, characterized in that an axial line (S) of the exhaust gas sensor (62) is arranged to be displaced in a predetermined dimension ( d) from the center line (E) of the passage of the exhaust port (40) to an internal part of a curved portion of the exhaust port (40). According to the first aspect of the invention, the exhaust gas is guided to the exhaust gas sensor (62) by means of the exhaust gas collection slot (64). Thus, the exhaust gas sensor (62) can be activated more quickly in the initial phase of the operation of the internal combustion engine (2).

According to the second aspect of the invention, the degree to which the oxygen concentration detector (69) is exposed in the passage inside the port can be reduced by using the effect of guiding the exhaust gases to the groove ( 64) exhaust gas collection. Additionally, the heat resistance of the exhaust gas sensor (62) has been increased because the detector (69) is less exposed to the exhaust gases at elevated temperature and pressure.

According to the invention, the exhaust gas sensor (62) has been provided on the side of the curved portion (Figure 3), that is, the surface (77) of the inner wall of the inner side of the curved exhaust port. Thus, the exhaust gas sensor (62) is less exposed to the exhaust gases at elevated temperature and pressure, and the heat resistance of the exhaust gas sensor (62) can be increased.

According to the fourth aspect of the invention, even the exhaust gas whose speed is relatively slow due to the neck portion (80) of the exhaust port (40), flows through the exhaust gas collection slot (64), and It is then sent to the exhaust gas sensor (62). In this way, the exhaust gas sensor (62) can be activated more quickly.

According to the fifth aspect of the invention, the exhaust stream flowing through the interior of the exhaust gas collection slot (64) directly impacts the oxygen concentration detector (69) of the sensor (62) of Exhaust gases, and thereby prevent it from diverting and reaching downstream of the exhaust gas sensor (62). In this way, the accuracy of the detector of the exhaust gas sensor (62) can be increased.

According to the sixth aspect of the invention, the time that elapses for the reaction to start during the start of the operation can be reduced even in the internal combustion engine (2) that is not equipped with the air quantity controller of intake (ACV: an idle air control valve).

According to the seventh aspect of the invention, the flow of exhaust gases inside the oxygen concentration detector (69) can be increased, and consequently the detection accuracy is increased.

According to the eighth aspect of the invention, the axial line (S) of the exhaust gas sensor (62) is arranged to be displaced in a predetermined dimension (d) from the central line (E) of the exhaust port passage (40). ) towards the inner part of the exhaust port curve (40). In this way, it is possible: to prevent the exhaust gases, which flow at a higher speed during high output, negatively affecting the performance of the internal combustion engine; and, effectively capture the exhaust gases, which flow towards the inside of the curved portion during the beginning of the operation when the lowest flow rate is slow, by using the gas collection slot (64) escape Consequently, the exhaust gas sensor (62) can be activated more quickly.

Other features and advantages of the invention will be highlighted from the detailed description that follows with reference to the drawings, in which:

Figure 1 is a view from the left side of a motorcycle of an embodiment of the present invention;

Figure 2 is a view from the left side of a motorcycle power unit;

Figure 3 is a view of a longitudinal cross section of a part of an internal combustion engine, which includes a cylinder head and its proximities, that part being viewed from the left side being seen;

Figure 4 is an arrow view taken along the line IV-IV of Figure 3;

Figure 5 is an arrow view taken in the direction of arrow V of Figure 4;

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

Figure 6 is a longitudinal sectional view of an exhaust gas sensor;

Figure 7 is a cross-sectional view taken along line VII-VII of Figure 3;

Figure 8 is a solid model view of an exhaust port taken in the direction of arrow VIII of Figure 7;

Figure 9 is a solid model view of an exhaust port taken in the direction of arrow IX of Figure

8;

Figure 10 is an enlarged cross-sectional view of the exhaust port and its vicinity, shown in Figure 3, and

Figure 11 is a cross-sectional view taken along line XI-XI of Figure 10.

Figure 1 is a view from the left side of a motorcycle 1 of an embodiment of the present invention. This motorcycle 1 includes a power unit 4 in which an internal combustion engine 2 and a power transmission system 3 are integrated. The internal combustion engine 2 is a single-cylinder internal combustion engine and a four-cycle time. The power unit 4 is installed on the motorcycle 1 with a crankshaft 5 directed in the direction from left to right.

In this motorcycle 1, paired forks 9 to the left and right that pivotally support a front wheel 8, are pivotally supported by means of a front tube 7 located in an extreme front portion of a frame 6 of the vehicle chassis with a bar of address 10 between them. A steering handle 11 is attached to an upper portion of the steering bar 10.

A single body frame 12, as the front portion of the frame 6 of the vehicle body, extends obliquely downwardly from the front tube 7, and is subsequently curved to extend horizontally backwards. A step step 13 on which the driver can place his feet is located in a horizontal portion of the main frame 12.

A rear end portion of the main frame 12 is attached to a middle portion of a cross frame 14 in the direction from left to right. The transverse frame 14 extends in the direction from left to right. Pivoting plates 15 paired to the left and right, are connected to the transverse frame 14. The power unit 4 is supported by a suspension joint 16, which is installed between the pivot plates 15 and the power unit 4, in such a way that the power unit 4 is oscillating in the vertical direction. A front end portion of a left rear frame 17L and a front end portion of a right rear frame 17R are attached to the respective left and right end portions of the transverse frame 14.

The left and right rear frames 17L, 17R extend obliquely upward from the transverse frame 14, and then bent to extend with reduced inclination. Intermediate portions of the respective left and right rear frames 17L, 17R that extend obliquely upwards, are connected and joined together by means of a transverse member 18. A middle front portion of the right rear frame 17R is taller than a middle portion front left rear frame 17L. The rear ends of the respective left and right rear frames 17L, 17R are connected and joined together by means of a connecting member 19 that extends horizontally in the width direction of the vehicle.

A seat 20 which includes a driver's seat and a passenger's seat, has been provided above the left and right rear frames 17L, 17R. A storage box 21 has been provided between the left and right rear frames 17L, 17R under a front portion of the seat 20. A fuel tank 22 has been provided under a rear portion of the seat 20. The frame 6 of the vehicle body It is covered by a body cover 23 made of a synthetic resin.

A rear portion of the power unit 4 is supported by the left rear frame 17L with a rear shock absorber 24 between them. A rear wheel 25 is pivotally supported by a rear end portion of the power transmission system 3. A front fender 26 has been provided above the front wheel 8, and a rear fender 27 has been provided above the rear wheel 25.

Figure 2 is a view from the left side of the power unit 4. The power unit 4 is formed by the internal combustion engine 2 and the power transmission system 3. A crankshaft 28 of the internal combustion engine 2 and a front portion of a housing 29 of the power transmission system 3, are connected to each other. The crankshaft 5 penetrates an intermediate wall between the internal combustion engine 2 and the power transmission system 3. The internal combustion engine 2 is formed by a cylinder block 30, a cylinder head 31 and a cylinder head cover 32, which are sequentially connected to each other in this order from the rear to the front of the crankshaft 28.

The power transmission system 3 is formed by a continuously variable V-belt transmission 33 and by a pinion speed reducer 34. An axis of a further rear pinion of the pinion speed reducer

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

60

34 is a rear wheel axle 35, and the rear wheel 25 (Figure 1) is integrally attached to the rear wheel axle 35.

Figure 3 is a view of a longitudinal cross section of a part of the internal combustion engine 2, which includes the cylinder head 31 and its surroundings, this part being viewed from the left side. In other words, Figure 3 is a view taken along one direction of a line C of axis of the cylinder. The descriptions of the drawings will be provided with the directions of the arrows Fr, Arr, Ab, which in the drawing indicate towards the front, up and down, respectively. In the drawing, the cylinder head 31 is connected to the cylinder block 30 by the use of bolts 36. The cylinder head cover 32 is connected to the cylinder head 31 with the use of bolts, which have not been shown . A curved intake port 39 has been formed in the upper portion of the cylinder head 31. An upstream end of the intake port 39 is open upward, and a downstream end thereof is open to a combustion chamber 38. A curved exhaust port 40 has been formed in a lower portion of the cylinder head 31. An upstream end of the exhaust port 40 is open to the combustion chamber 38, and a downstream end thereof is open downward.

In the cylinder head 31, an intake valve 42 for opening and closing an inlet port 41 of the combustion chamber 38 and an exhaust valve 44 for opening and closing an outlet port 43 of the combustion chamber 38, are slidably coupled in their respective valve guides 45. An intake tube 46 is connected to an opening of the upstream end of the intake port 39. An accelerator body 37 (Figure 2) is connected to an end upstream of the intake tube 46. A fuel injection valve 47 is attached to the intake pipe 46. A front end of the fuel injection valve 47 faces the intake port 39. An exhaust pipe 48 (Figure 1) is connected to one end. downstream of the exhaust port 40.

The intake and exhaust valves 42, 44, pushed in their valve closing directions by respective valve springs 49, are actuated to open and close by means of a valve system 51 inside a valve chamber 50 which is formed by the cylinder head 31 and the cylinder head cover 32. A single camshaft 52 is supported horizontally, rotatably and pivotally by ball bearings in the valve chamber 50. An intake cam 53 and a Exhaust cam 54 has been integrally formed with the camshaft 52. An intake rocker shaft 55 has been provided on the cylinder head 31 at the front and above the cam shaft 52. An exhaust rocker shaft 56 ha provided at the cylinder head 31 in front and below the camshaft 52. An intake swing arm 57 and an exhaust swing arm 58 are pivotally supported pivotally by the intake rocker shaft 55 and by the exhaust rocker shaft 56, respectively. Rollers 59 in contact with the cams 53, 54 are pivotally supported by ends of the oscillating arms 57, 58, respectively. Contact members 60 are subject to the other ends of the swinging arms 57, 58, respectively. These contact members 60 are in contact with upper portions of the intake and exhaust valves 42, 44, respectively. The contact members 60 open and close the respective intake and exhaust valves 42, 44 in accordance with the rotation of the camshaft 52.

A fixing hole 63 for an exhaust gas sensor 62 has been opened on an inner wall surface of the exhaust port 40, in a portion near the downstream end. A front end portion of the exhaust gas sensor 62 is exposed inside the exhaust port 40. An exhaust gas collection slot 64 extending from an upstream portion of the exhaust port 40 to the fixing hole 63, It has been provided on the inner wall of the exhaust port 40. Further descriptions of how this slot works will be provided.

Figure 4 is an arrow view taken along the line IV-IV of Figure 3. In other words, Figure 4 is a view of the cylinder head 31, taken from the rear in the direction of the Cylinder axis line C. Otherwise, Figure 3 is a cross-sectional view taken along the MI-MI line of Figure 4. The directions indicated by the arrows Arr, Left and Right, in the drawing , represent upwards, to the left and to the right, respectively. Figure 4 is a view of the cylinder head 31 taken from the combustion chamber 38. A surface around the combustion chamber 38 is a contact surface 65 with the cylinder block 30. The inlet and outlet ports 41, 43 of combustion chamber 38 have been shown in the drawing. The intake port 39 communicates with the input port 41, and the exhaust port 40 communicates with the output port 43. The exhaust gas sensor 62 is attached to the cylinder head 31 such that the sensor 62 Exhaust gas faces the downstream portion of the exhaust port 40.

In Figures 3 and 4, the shape of the passage of the exhaust port 40 is curved from the outlet port 43 towards a holding portion 74 of the exhaust pipe in the side view of the internal combustion engine 2 (Figure 3) taken to along the direction of the C axis line of the cylinder. Additionally, the shape of the passage of the exhaust port 40 is curved according to the direction from left to right in the view (Figure 4), in the direction of the direction of axis C of the cylinder. In the drawing, the exhaust gas collection slot 64 extending in the direction of the flow of the exhaust gases, has been provided on the inner wall of the exhaust port 40 between the outlet port 43 and the portion 74 of fixing the exhaust pipe. Orifice 63 for fixing the gas sensor is provided

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

60

exhaust, and the exhaust sensor 62 is fixed in the fixing hole 63 of the exhaust sensor, such that the front end portion of the exhaust sensor 62 is located at the rear of the groove 64 exhaust gas collection. For this reason, the exhaust gas is guided to the exhaust gas sensor 62 by the exhaust gas collection slot 64. In this way, the exhaust gas sensor 62 can be activated more quickly when the internal combustion engine is started.

Figure 5 is an arrow view taken in the direction of arrow V of Figure 4. The uppermost portion of this drawing represents the contact surface 65 with the cylinder block 30, and the lower portion of this drawing represents a contact surface 66 with the cover 32 of the cylinder head. A flange 67 for fixing the exhaust pipe has been marked with an imaginary line. The exhaust gas sensor 62 has been fixed, directed to the exhaust port 40.

Figure 6 is a longitudinal sectional view of the exhaust gas sensor 62. A detector element 68 is located in the intermediate portion of the exhaust gas sensor 62. The detector element 68 is obtained by: forming a solid electrolyte that essentially contains zirconia (ZrO2) in a tube closed at one end; and, adhesion of a thin platinum film (Pt) to the outer surface of the resulting closed end tube. The detector element 68 is designed in such a way that the atmosphere penetrates inside the detector element 68 while the outer portion of the detector element 68 is exposed to the exhaust gases. A front end portion of the exhaust gas sensor 62 is an oxygen concentration detector 69. A protective cover 71 of the element, having numerous pores 70, has been provided in the front end portion of the exhaust gas sensor 62. The exhaust gas enters the interior of the exhaust gas sensor 62 through the pores 70, and comes into contact with the outer periphery of the detector element 68. The atmosphere is introduced through an atmosphere introduction port 72, through a filter 73. An electromotive force is produced due to the difference in oxygen concentration between the inside and outside of element 68. The detection of oxygen concentration is achieved by detecting the electromotive force. For the purpose of detecting the electromotive force of the exhaust gas sensor 62, an electric cable 61 connected to the inside and outside of the element extends outwardly from an end portion of the exhaust gas sensor 62. It is possible to know a change in the concentration of oxygen by means of a sudden change in the electromotive force that takes place around a theoretical air-fuel ratio. A condition in which the exhaust gas sensor 62 detects the oxygen concentration more precisely, in other words, a temperature of the element 68 in the activated state, is not less than 300 ° C, but is not greater than 900 ° C. For this reason, the temperature of element 68 is required to rise as quickly as possible, when the internal combustion engine is started. Additionally, it is required that element 68 not be heated to an excessively high temperature during operation.

Figure 7 is a cross-sectional view taken along the line VN-VN of Figure 3. Figure 7 is a cross-sectional view of the exhaust port 40, the exhaust gas sensor 62 and its proximities shown in Figure 4, the cross section being seen from the back of Figure 4. This is an enlarged cross sectional view showing in detail a fixing portion to which the exhaust gas sensor 62 is attached. The representation of the exhaust valve 44 has been omitted. The outlet port 43 is seen in the upstream portion of the exhaust port 40. The main stream of the exhaust gases flows in the direction of the arrow F. The leading end of the detector 69 of the exhaust gas sensor 62 is exposed to the exhaust gas stream. The exhaust gas reaches the outer surface of the element 68 (Figure 6) through the multiple pores 70 that have been provided in the protection cover 71 of the element.

In Figure 7, the exhaust gas collection slot 64 and the exhaust gas sensor 62 have been provided on an inner wall surface 77 on the inner side of the curved exhaust port. During high speed operation of the internal combustion engine 2, the high temperature and pressure exhaust gas flows at high speed along a surface 78 of the inner wall of the outer side of the curved exhaust port, which is toward outside the exhaust gas collection slot 64 and the exhaust gas sensor 62. For this reason, during high speed operation, the exhaust gas sensor 62 is less exposed to the exhaust gases at elevated temperature and pressure, and the heat resistance of the exhaust gas sensor 62 is consequently increased.

Figures 8 and 9 are each a solid model view of the exhaust port 40. Although the exhaust port 40 is a space that has no solid existence, Figures 8 and 9 are perspective views of a model that is produced as if the exhaust port 40 had a solid existence. Figure 8 shows a view in the direction of arrow VIII of Figure 7. Figure 9 is a view in the direction of arrow IX of Figure 8.

In Figure 8, the exhaust gas collection slot 64 is formed in such a way that an imaginary terminal end 75 of the rearwardly extending groove, which is formed by extending the wall surface of the groove in the direction downstream, it mostly coincides with the oxygen concentration detector 69 of the exhaust gas sensor 62. For this reason, the exhaust gas flowing through the exhaust gas collection slot 64 directly impacts the detector 69 of the exhaust gas sensor 62. This makes it possible to prevent the exhaust gases from diverting and running downstream of the exhaust gas sensor 62. Consequently, the detection accuracy of the exhaust gas sensor 62 can be increased.

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

In Figure 7, the exhaust gas sensor 62 has been positioned directed to the exhaust port 40 in such a way that the exhaust gas sensor 62 projects the downstream side to the upstream side with respect to a central line E of the passage of the exhaust port 40. The flow direction F of the main stream of the exhaust gases coincides with the center line E of the passage of the exhaust port 40. In other words, in Figure 7, an angle to between The flow direction F of the main stream of the exhaust gases and an axial line S of the exhaust sensor 62 is sharp. This makes it possible to improve the flow of exhaust gases inside the detector 69 of the exhaust sensor 62, and consequently, increase the accuracy of the detection.

Figure 10 is an enlarged cross-sectional view of the exhaust port 40 and its proximities shown in Figure 3. Figure 11 is a cross-sectional view taken along line XI-XI of Figure 10 The lower portion of each of Figures 10 and 11 represents the contact surface 65 with the cylinder block 30. The front end of the exhaust gas sensor 62 is exposed inside the exhaust port 40.

In Figure 10, the exhaust gas collection slot 64 is formed, extending upstream and downstream of a neck portion 80 (see also Figure 8) where the exhaust port 40 becomes narrower due to a portion 79 for securing the valve guide. Because even the exhaust gas whose speed slows down due to the neck portion 80 flows into the exhaust gas collection slot 64, it is possible to activate the sensor more quickly in an initial phase of commissioning.

In Figure 11, a base 71a of the exhaust gas sensor element protection cover 71 is located in the fixing hole 63 of the exhaust gas sensor, and a front end portion 71b of the protection cover 71 of element is located in the passage of the exhaust gases of the exhaust port 40. The purpose of this arrangement is to reduce the exposure of the detector 69 to the exhaust gases at elevated temperature and pressure by reducing the degree to which the detector 69 is exposed to the passage of the gases in the exhaust port 40 by using the guiding effect of the exhaust gases, and to allow the oxygen concentration to be detected while increasing the heat resistance of the exhaust gas sensor 62.

In Figures 10 and 11, the axial line S of the exhaust gas sensor 62 is arranged so that it has moved in a dimension d from the center line E of the exhaust port 40 towards the inside of the curve of the Exhaust port 40, that is, towards the contact surface 65 with the cylinder block 30. During the start of the internal combustion engine 2, when the exhaust gas is circulating at low speed, the exhaust gas stream flows to the inner part of the curved portion in the direction of the arrow L in Figure 10. This flow is effectively captured by the exhaust gas collection slot 64. For this reason, activation can be achieved promptly in the initial phase of commissioning. During the high output of the internal combustion engine 2, the exhaust gas sensor 62 does not obstruct the flow of the exhaust gases because: the flow rate of the exhaust gases is rapid; and, the exhaust flows accordingly through the outside of the curved portion in the direction of arrow H in Figure 10.

The embodiment controls the timing of the ignition and the amount of fuel injection with the amount of intake air kept constant, when the internal combustion engine is started 2. To expose it concretely, the embodiment makes it possible to reduce the time it takes for the reaction to start, even in a case where control is carried out by increasing the advance angle for the moment of ignition and the amount of fuel injection without carrying out the air control of admission or the like when the engine starts, in a structure where you cannot expect the engine to accelerate due to the increase in engine speed through the warm-up operation.

As described in detail above, the realization has the following effects:

1. (1) The exhaust gas is guided to the exhaust gas sensor 62 through the exhaust gas collection slot 64. In this way, the exhaust gas sensor 62 can be activated more quickly in the initial phase of the operation.

2. (2) Only the front end portion of the exhaust shield 71 of the exhaust gas sensor 62 is located in the exhaust port 40. Thus, the function of the gas sensor 62 can be fully utilized. and the heat resistance of the exhaust gas sensor 62 can be increased by reducing the exposure of the exhaust gas sensor 62 to the exhaust gases at elevated temperature and pressure.

3. (3) The exhaust port 40 is configured as a curve when viewed in the direction of the axial line C of the cylinder (Figure 4) and the exhaust gas collection slot 64 and the gas sensor 62 Exhaust are arranged in the inner wall of the inner side of the curved exhaust port 40. In this way, the exposure of the exhaust gas sensor 62 to the exhaust gases at elevated temperature and pressure, and the heat resistance of the exhaust can be reduced Exhaust gas sensor 62 can be increased accordingly.

4. (4) The gas whose speed slows down due to the holding portion 79 of the valve guide circulates

5

10

fifteen

twenty

25

30

35

40

Four. Five

also in the exhaust gas collection slot 64 and thereby sent to the exhaust gas sensor 62. Therefore, the exhaust gas sensor 62 can be activated more quickly.

5. (5) The exhaust gas collection slot 64 is formed in such a way that the imaginary termination portion 75 extended rearward of the exhaust gas collection slot 64, which is formed by extending the surface of the internal wall thereof in the downstream direction, mostly coincides with the oxygen concentration detector 69 of the exhaust gas sensor 62. Thus, the exhaust gas flowing inside the exhaust gas collection slot 64 flows concentratedly towards the detector 69 of the exhaust gas sensor 62, and consequently it is possible to increase the detection accuracy of the detector 69 of the exhaust gas sensor 62.

6. (6) The time it takes for the activation to begin can be reduced even in the internal combustion engine 2 that does not control the amount of the intake air.

7. (7) The exhaust gas sensor 62 is positioned in such a way that the axial line S thereof inclines towards the upstream side with respect to the center line E of the exhaust port 40. In this way , the exhaust gas flows well inside the exhaust gas sensor 62 and the detection performance can be increased accordingly.

8. (8) The exhaust gas sensor 62 is arranged so that it is displaced by the predetermined dimension d from the center line E of the exhaust port 40 towards an internal part of the curved portion of the exhaust port when view from the side (that is, towards the contact surface 65 with the cylinder block 30). Thus, even during the start-up of the internal combustion engine 2 when the exhaust gas flows at low speed, the exhaust gas collection slot 64 is capable of effectively capturing the exhaust gas stream, and activation can be achieved promptly in the initial phase of commissioning. Additionally, during the high output at which the flow rate of the exhaust gases is higher, the exhaust gas sensor 62 does not impede the flow of the exhaust gases.

Main reference numbers

2 internal combustion engine

31 cylinder head

40 exhaust port

43 exit port

44 exhaust valve

45 valve guide

62 exhaust gas sensor

63 fixing hole of the exhaust gas sensor

64 exhaust gas collection slot

69 oxygen concentration detector

71 element protective cap

74 exhaust pipe fixing portion

75 imaginary termination portion extended rear of the exhaust gas collection slot 64

77 inner wall surface of the inner side of the curved exhaust port

78 inner wall surface of the outer side of the curved exhaust port

79 clamping portion of the valve guide

80 neck portion of the exhaust port 40

C axial cylinder line

D displacement dimension of the exhaust gas sensor E central passage line of the exhaust port 40

S axial line of the exhaust gas sensor 62.

Claims (8)

5 10 fifteen twenty 25 30 35 40 Four. Five 1. - A structure in a cylinder head (31) of an internal combustion engine (2) for fixing a sensor (62) of exhaust gases, where an exhaust port (40) has been provided between an outlet port (43) and a fixing portion (74) of an exhaust pipe, the outlet port (43) being an upstream inlet to the exhaust port (40), the fixing portion (74) of the exhaust pipe being an outlet of the exhaust port, characterized in that an exhaust gas collection slot (64) is provided which extends in a flow direction of an exhaust gas, in an internal wall of the exhaust port (40), the slot (64) having been provided collection of exhaust gases on an inner wall surface (77) of the inner side of the curved exhaust port, and the exhaust gas sensor (62) being fixed thereto, and the exhaust gas sensor (62) fixed in a way that a front end portion of the gas sensor (62) Exhaust is located at the rear of the exhaust gas collection slot (64). 2. - The structure for fixing an exhaust gas sensor of claim 1, wherein: a base of a protective element cover (71) of the exhaust gas sensor (62) is located in a hole (63) fixing the exhaust gas sensor, and A front end portion of the protective element cover (71) is located in a gas passage of the exhaust port (40). 3. - The structure for fixing an exhaust gas sensor of claim 2, wherein: The shape of the passage of the exhaust port (40) is curved from the outlet port (43), which is an opening and closing port of an exhaust valve (44), towards the fixing portion (74) of the exhaust pipe according to a side view (Figure 3), which extends in the direction of an axial line (C) of the cylinder, The shape of the passage of the exhaust port (40) is also curved in a direction from left to right if you look at the direction of the axial line (C) of the cylinder (Figure 4). 4. - The structure for fixing an exhaust gas sensor of any one of claims 1 and 2, wherein the exhaust gas collection slot (64) has been formed, extending upstream and downstream of a clamping portion (79) for holding a valve guide (45) (in proximity to a neck portion (80) of the exhaust port), which has been provided in the exhaust port (40). 5. - The structure for fixing an exhaust gas sensor of claim 4, wherein the exhaust gas collection slot (64) is formed in such a way that an imaginary termination portion (75) extended towards At the rear, which is formed by extending a wall surface of the exhaust gas collection slot (64) in the downstream direction, it almost coincides with an oxygen concentration detector (69) of the exhaust gas sensor (62). 6. - The structure for fixing an exhaust gas sensor of claim 5, wherein, when the internal combustion engine (2) is started, the internal combustion engine (2) is controlled by the control of an instant of ignition and of a quantity of fuel injection with a quantity of intake air kept constant. 7. - The structure for fixing an exhaust gas sensor of any one of claims 4 and 5, wherein the exhaust gas sensor (62) is placed in the groove in a manner that the sensor (62) Exhaust gas is projected from a downstream side to an upstream side with respect to the center line (E) of the exhaust port (40). 8. - The structure for fixing an exhaust gas sensor of claim 7, wherein an axial line (S) of the exhaust gas sensor (62) is arranged so that it is offset in one dimension (d) predetermined from the center line (E) of passage of the exhaust port (40) towards an inner part of a curved portion of the exhaust port (40).