JP2001304050A - Gas leading device for intake passage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably support a valve stem without increasing an intake resistance by a bearing, and uniformly mix gas other than outside air with outside air. SOLUTION: A gas leading device 12 is provided with an internal tube part 17, an external tube part 18, a clearance 19, a leading inlet 21 disposed on the external tube part 18, a plurality of leading holes 23a, 23b for leading gas from the clearance 19 to an intake passage 14, a valve seat 31 disposed on the leading inlet 21, a valve element 32 corresponding to the valve seat 31, the valve stem 33 extending to the direction perpendicular to the intake passage 14 from the valve element 32, an actuator 34 disposed on a side opposed to the leading inlet 21 sandwiching the intake passage 14, the first bearing 36 for supporting a tip end part of the valve stem 33 in the vicinity of the leading inlet 21, the second bearing 37 for supporting an end part of the valve stem 33 in the vicinity of the actuator 34, and a sleeve 40 for enclosing the valve stem 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas introduction device for an intake passage, which is provided in an intake passage for guiding outside air to an engine and introduces a gas other than the outside air into the passage.

[0002]

2. Description of the Related Art Conventionally, as a gas introduction device of this type, for example, exhaust gas recirculation (EGR) is provided in an intake passage of an engine.
There is a gas introduction device provided to introduce the gas. EGR is to recirculate a part of the exhaust gas discharged from the combustion chamber to the exhaust passage to the intake passage. The EGR gas is introduced into the intake passage, mixed with outside air, and sucked into the combustion chamber, thereby lowering the combustion temperature of the combustible mixture in the combustion chamber and reducing the amount of nitrogen oxides (NOx) in the exhaust gas. Can be reduced.

In an EGR device that handles EGR gas,
E to regulate the introduction of EGR gas into the intake passage
A GR valve is provided. Previously, an EGR valve was sometimes provided for the EGR passage on the upstream side of the gas introduction device. However, since the EGR gas is at a high temperature, it is necessary to ensure high-temperature reliability of the actuator constituting the EGR valve. For this reason, it is necessary to separately provide auxiliary equipment such as a cooling device for the EGR valve, and there has been a problem that the configuration is complicated.

In view of the above, an EGR valve is incorporated in the gas introducing device, and a valve element and a valve seat constituting the EGR valve and an actuator for driving the valve element are provided separately with an intake passage interposed therebetween. Some proposals have been made to avoid the effects of hot gas. Japanese Patent Laying-Open No. 10-89161 discloses an example of this type of gas introduction device.

[0005] In the gas introducing device of the above publication, a gas inlet 53 for introducing EGR gas into an intake passage 52 is provided in a casing 51 as shown in FIG. A valve body 55 is provided corresponding to the valve seat 54 provided in the gas inlet 53. A valve shaft 56 extending from the valve body 55 is provided to penetrate the casing 51 in a direction orthogonal to the intake passage 52. An actuator 57 for driving a valve element 55 via a valve shaft 56 is provided on the casing 51 on the opposite side of the arrangement of the gas inlet 53. Intake passage 52
A guide portion 5 functioning as a bearing for the valve shaft 56
8 are provided. Further, a support leg 60 that forms an air flow path 59 communicating with the gas inlet 53 is provided continuously to the guide portion 58. Therefore, the valve shaft 56 is
By driving the valve element 55 through the valve seat 55, the valve seat 55 is moved with respect to the valve seat 54, and the introduction of EGR gas from the gas inlet 53 and the air flow path 59 to the intake passage 52 is adjusted. Further, since the valve body 55 and the valve seat 54 and the actuator 57 are provided separately with the intake passage 52 interposed therebetween, the heat of the high-temperature EGR gas guided to the gas inlet 53 may affect the actuator 57. Absent.

[0006]

However, in the conventional gas introducing device, a guide portion 58 having a certain length and an outer diameter is provided near the center of the intake passage 52, and the supporting legs 60 connected to the guide portion 58 are connected to the intake leg 52. It is provided in the passage 52. Moreover, a part of the actuator 57 protrudes greatly into the intake passage 52. For this reason, there is a problem that these themselves increase the intake resistance in the intake passage 52.

In the structure of the conventional gas introducing device, since it is inherently difficult to provide a bearing adjacent to the gas inlet 53, the arrangement of the guide portion may be changed to a position adjacent to the actuator 57. Can be However, in this case, in order to minimize the vibration of the valve shaft 56 due to the flow of the intake air, the guide portion must also be set to a certain length, and there is a problem in the intake resistance.

Further, in the conventional gas introducing apparatus, since the gas inlet 53 is simply opened directly to the intake passage 52, it is difficult to mix the EGR gas into the outside air without unevenness. For this reason, the EGR gas cannot be uniformly taken into each of the plurality of cylinders of the engine.
It is difficult to maximize the effects of GR.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to stably support a valve shaft without increasing the intake resistance of a bearing, and to uniformly distribute gases other than the outside air to the outside air. It is an object of the present invention to provide a gas introduction device for an intake passage which enables mixing.

[0010]

Means for Solving the Problems To achieve the above object, an invention according to claim 1 is a gas introduction device for introducing a gas other than the outside air into an intake passage through which outside air flows. Inner pipe part, an outer pipe part arranged at a predetermined gap on the outer periphery of the inner pipe part, an inlet provided in the outer pipe part for introducing gas other than outside air into the gap, In order to introduce the introduced gas into the intake passage, an introduction hole provided at a position not opposed to the introduction port of the inner pipe portion, a valve seat provided corresponding to the introduction port, and a valve seat corresponding to the introduction port are provided. The provided valve element, a valve shaft extending from the valve element and penetrating the inner pipe section and the outer pipe section in a direction orthogonal to the intake passage, and provided on the outer pipe section opposite to the arrangement of the inlet, An actuator for driving the valve body through the valve shaft, and a position adjacent to the inlet for supporting one end of the valve shaft. A first bearing provided on the inner tube portion and a second bearing provided on at least one of the inner tube portion and the outer tube portion at a position adjacent to the actuator for supporting the other end of the valve shaft. It is intended to have.

According to the configuration of the present invention, by operating the actuator, the valve body is separated from the valve seat via the valve shaft, and the inlet is opened. Then, the gas that has reached the inlet is introduced around the gap and is introduced into the intake passage from the inlet, and is mixed with the outside air without unevenness. Here, since the valve body, the valve seat, and the actuator are provided separately with the intake passage interposed therebetween, even if the gas guided to the inlet is at a high temperature, the heat is not directly transmitted to the actuator. Since one end of the valve shaft is supported by the first bearing and the other end of the valve shaft is supported by the second bearing, the valve shaft will be supported at both ends, and each of the valve shafts will be supported. Displacement against external force is small at the end. Further, since the first bearing is provided at a position adjacent to the introduction port and the second bearing is provided at a position adjacent to the actuator, each bearing is compared with the case where one valve supports the valve shaft. It is possible to shorten the length, and the protrusion of each bearing with respect to the intake passage is reduced.

According to a second aspect of the present invention, in order to achieve the above object, there is provided an atmosphere passage for allowing a gap between the first bearing and the valve shaft to communicate with the atmosphere. Is provided along the valve shaft.

According to the configuration of the present invention, in addition to the function of the first aspect of the present invention, the portion of the gap between the first bearing and the valve shaft facing the inlet is formed through the gap and the inlet. The intake negative pressure acts, and the atmospheric pressure acts from the other side of the gap through the atmosphere passage. Therefore, the gas introduced from the inlet into the gap does not enter the gap facing the inlet. Further, since the atmosphere passage is provided along the valve shaft, the area occupied by the atmosphere passage with respect to the outside airflow of the intake passage can be minimized.

According to a third aspect of the present invention, in the above-mentioned second aspect, the air passage is provided with a sleeve and a valve provided in the inner pipe portion so as to include the valve shaft. It is intended to include a gap between the shaft and the shaft.

According to the configuration of the present invention, in addition to the operation of the second aspect, the air passage is formed by the gap between the sleeve enclosing the valve shaft and the valve shaft. The air passage is integrated with the air passage, and the area occupied by the air passage with respect to the external airflow in the intake passage is minimized.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment of a gas introduction device for an intake passage according to the present invention will be described below in detail with reference to the drawings. In this embodiment, a gas introduction device that introduces EGR gas into an intake passage of an engine will be described.

FIG. 1 is a sectional view of an intake manifold 11, a gas introducing device 12, and a throttle body 13 connected in series to each other. FIG. 2 is a sectional view taken along line 2-2 of FIG.

As shown in FIG. 1, the intake manifold 1
1. The gas introduction device 12 and the throttle body 13 constitute a series of intake passages 14. The portion of the intake manifold 11 to which the gas introduction device 12 is connected is the same as the manifold 1
Reference numeral 1 denotes a base pipe portion before branching into a plurality of branch pipes. A throttle valve 15 for opening and closing the intake passage 14 is provided on the throttle body 13 so as to be rotatable about a support shaft 16. By turning the throttle valve 15, the opening degree of the intake passage 14 is adjusted, and the outside air flowing through the passage 14 is adjusted.

The gas introducing device 12 connected to the downstream side of the throttle body 13 is for introducing EGR gas into the intake passage 14 as a gas other than the outside air. This gas introduction device 12 has a double pipe structure including an inner pipe part 17 and an outer pipe part 18. The inside of the inner pipe portion 17 forms the intake passage 14. The outer tube portion 18 is arranged on the outer periphery of the inner tube portion 17 with a predetermined gap 19 therebetween. As shown in FIG.
Is provided on almost the entire circumference of both pipe parts 17, 18 except for a part. As shown in FIG. 1, the inner pipe portion 17 and the outer pipe portion 18 are connected to each other at their downstream ends and are integrally formed. As shown in FIG. 1, at the upstream end surfaces of the inner pipe portion 17 and the outer pipe portion 18, a gap 19 is opened to form a gap opening 20. As shown in FIG. 1, the gap opening 20 is joined and sealed to the end surface of the throttle body 13. Figures 1 and 2
As shown in FIG.
An introduction port 21 for introducing the gas into the container is formed. Outer tube part 18
The pipe joint 22 corresponding to the inlet 21 is integrally formed. The pipe joint 22 includes an EGR device that constitutes an EGR device.
A passage (not shown) is connected.

As shown in FIGS. 1 and 2, a plurality (two in this case, large and small) of EGR gas to be introduced into the gap 19 is introduced into the intake passage 14 at a predetermined position of the inner pipe portion 17. Holes 23a and 23b are formed. These introduction holes 23
a and 23b extend from the middle part of the inner pipe part 17 to the downstream end face. These introduction holes 23a and 23b are arranged at positions not facing the introduction port 21. As shown in FIG. 1, the end face of the connecting part 24 between the inner pipe part 17 and the outer pipe part 18 is joined and sealed to the end face of the intake manifold 11.

A valve seat 31 is provided inside the pipe joint 22 corresponding to the inlet 21. A valve body 32 is provided corresponding to the valve seat 31. A valve shaft 33 extending from the valve body 32 includes:
The inner pipe portion 17 and the outer pipe portion 1 extend in a direction orthogonal to the intake passage 14.
8 is provided. An actuator 34 for driving the valve body 32 via the valve shaft 33 is provided on the outer tube portion 18 on the side opposite to the arrangement of the inlet 21. The actuator 34 is mounted on the pedestal 2 integrally formed with the outer tube portion 18.
Fixed to 5. The pedestal 25 is provided with a vent hole 25a for allowing the internal space to communicate with the atmosphere. The electric actuator 34 reciprocates the output shaft 34a along the axial direction. This output shaft 34a has a valve shaft 3
3 are connected. The output shaft 34a is provided with a spring 35 for urging the valve body 32 together with the valve shaft 33 in a direction for seating on the valve seat 31.

A first bearing 36 for supporting the distal end of the valve shaft 33 is provided in the inner pipe portion 17 at a position adjacent to the inlet 21. This bearing 36 is fitted into a recess 17 a provided on the outer periphery of the inner pipe portion 17. At a position adjacent to the actuator 34, the inner pipe 17 and the outer pipe 1
A second bearing 37 for supporting the base end of the valve shaft 33 is provided at a portion connected to the bearing 8. The bearing 37 is fitted into a recess 18 a provided on the outer periphery of the outer tube portion 18.

Between each of the bearings 36 and 37 and the valve shaft 33,
There are minute gaps 38 and 39. The inner pipe 17 has a valve shaft 3
The sleeve 40 is integrally formed so as to include the sleeve 3. To allow the gaps 38, 39 between the bearings 36, 37 to communicate with each other, a minute gap 4 is provided between the sleeve 40 and the valve shaft 33.
1 is provided. The air gap provided along the valve shaft 33 is formed by the gaps 39 and 41 and the air holes 25a and the like so as to allow the gap 38 between the first bearing 36 and the valve shaft 33 to communicate with the atmosphere. You. The outer diameter of the sleeve 40 is equal to or smaller than the outer diameter of the support shaft 16 of the throttle valve 15 located on the upstream side of the gas introduction device 12.

As described above, according to the gas introducing device 12 of the present embodiment, the output shaft 34 of the actuator 34
When a is extended, the valve element 32 is separated from the valve seat 31 via the valve shaft 33, and the introduction port 21 is opened. As a result, FIGS.
As shown by the arrows in FIG. 3, the high-temperature EGR gas flowing through the EGR passage and reaching the inlet 21 is introduced around the gap 19 and introduced into the intake passage 14 from each of the introduction holes 23a and 23b. Mixed without. Therefore, the EGR gas can be uniformly taken into each of the plurality of cylinders of the engine, and the EGR effect can be maximized. On the other hand, the output shaft 3 of the actuator 34
4a, the valve element 32 is moved through the valve shaft 33 to the valve seat 31.
And the inlet 21 is closed. Thereby, the introduction of the EGR gas from the inlet 21 to the gap 19 is shut off,
The introduction of the EGR gas into the intake passage 14 is shut off, and the mixing of the outside air and the EGR gas can be stopped.

Here, according to the gas introduction device 12,
Since the valve body 32 and the valve seat 31 and the actuator 34 are provided separately with the intake passage 14 interposed therebetween, the inlet 2
The heat of the high-temperature EGR gas led to
There is no direct transmission to 4. For this reason, there is no need to provide additional equipment such as a cooling device, and high-temperature reliability of the actuator 34 functioning as a part of the EGR valve can be easily secured.

According to the gas introducing device 12, the valve shaft 33
Is supported by the first bearing 36, and the base end of the valve shaft 33 is supported by the second bearing 37, so that the valve shaft 33 is reliably supported at both ends. The displacement of each end of the valve shaft 33 with respect to an external force is reduced. Therefore, vibration of the valve shaft 33 can be suppressed, and the valve shaft 33 can be stably supported. As a result, the valve shaft 33 is connected to the dual bearing 3.
6, 37 can be smoothly reciprocated, and the opening and closing operation of the valve body 32 by the actuator 34 can be made smooth.

According to the gas introducing device 12, the first bearing 36 is provided at a position adjacent to the inlet 21 and the second bearing 37 is provided at a position adjacent to the actuator 34. This makes it possible to shorten each of the bearings 36 and 37 as compared with the conventional gas introducing device in which the valve shaft 56 is supported by one bearing (the guide portion 58). The overhang to the passage 14 is reduced. Therefore, by providing the respective valve shafts 36 and 37, the intake resistance in the intake passage 14 does not increase,
Rather, the intake resistance can be reduced as compared with the conventional gas introduction device described above. That is, according to the gas introducing device 42, the valve shaft 33 can be stably supported by the dual bearings 36 and 37 without increasing the intake resistance in the intake passage 14.

According to the gas introduction device 12, a portion of the gap 38 between the first bearing 36 and the valve shaft 33 facing the introduction port 21 is provided with an intake negative pressure generated downstream of the throttle valve 15. Acts through each of the introduction holes 23 a and 23 b and the gap 19. Further, from the other side of the gap 38, the ventilation hole 25a of the pedestal 25, the second bearing 37 and the valve shaft 3
Atmospheric pressure acts through an air passage formed by a gap 39 between the valve shaft 3 and a gap 41 between the valve shaft 33 and the sleeve 40. That is, as shown in FIG. 2, the internal pressure of the pedestal 25 is the atmospheric pressure Pa, the pressure of the intake passage 14 is the intake pressure Pb, the pressure near the gap 38 facing the inlet 21 is the gap pressure Pc,
Assuming that the pressure at the inlet of the pipe joint 22 is the exhaust pressure Pd, the relationship between them is represented by the following equations (1) to (3). Pb ≒ Pc (1) Pa> Pb (2) Pa> Pc (3) Accordingly, the suction negative pressure acting on the gap 19 acts on the gap 38 facing the inlet 21. That is, the EGR gas introduced from the inlet 21 into the gap 19 does not enter the gap 38. Therefore, fine foreign substances such as carbon contained in the EGR gas do not enter the gaps 38, 39, 41, and the valve shaft 33 is prevented from being fixed to the bearings 36, 37 and the sleeve 40. can do.

According to the gas introducing device 12, the above-mentioned air passage is provided along the valve shaft 33. Specifically, the gap 4 between the sleeve 40 containing the valve shaft 33 and the valve shaft 33.
1 forms an atmosphere passage. Accordingly, the valve shaft 33 and the atmosphere passage are integrated, and the area occupied by the atmosphere passage with respect to the outside airflow of the intake passage 14 is minimized. For this reason,
Even if an air passage is provided in the intake passage 14, the intake passage 14
In this case, the increase in the intake resistance can be minimized.

According to the gas introducing device 12, the inner pipe 1
7 and the outer tube portion 18 are connected by the connecting portion 24 or the like to be integrally formed.
9, the inner pipe portion 17 and the outer pipe portion 19 are linearly expanded integrally. For this reason, it is possible to prevent a linear expansion difference between the inner tube portion 17 and the outer tube portion 18 from occurring, and to prevent a deformed deformation from occurring. In this sense, reliability against high temperatures can be improved. or,
Since the inner tube portion 17 and the outer tube portion 18 are integrally formed, there is no need to assemble the two tube portions 17, 18. For this reason, the manufacturing of the gas introduction device 12 can be facilitated by an amount not requiring the assembling process.

According to the gas introduction device 12, the introduction holes 23a and 23b are arranged at positions not facing the introduction port 21. Therefore, the EGR gas reaching the inlet 21 is not immediately introduced into the intake passage 14 through the inlets 23a and 23b, but is introduced into the intake passage 14 from the inlets 23a and 23b at a position away from the inlet 21. Will be done. For this reason, the EGR gas can be appropriately dispersed in each of the introduction holes 23a and 23b, and the EGR gas can be more evenly mixed with the outside air as compared with the case where the introduction port faces the introduction hole.

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a sectional view similar to FIG. FIG. 4 is a sectional view taken along line 4-4 in FIG. 3 according to FIG. 3 and 4, the same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The gas introducing device 42 of this embodiment differs from the gas introducing device 12 of the first embodiment in that the sleeve 40 provided on the inner tube 17 is omitted.
Therefore, the elimination of the sleeve 40 eliminates the atmosphere passage that connects the gap 38 of the first bearing 36 to the atmosphere. For this reason, the same operation and effect as the gas introduction device 12 can also be obtained by the gas introduction device 42 except for the operation and effect by the air passage.

It should be noted that the present invention is not limited to the above-described embodiment, and can be carried out as follows without departing from the spirit of the invention.

(1) In each of the above embodiments, two large and small inlet holes 23a and 23b are provided in the inner tube portion 17. However, two or more inlet holes having the same size may be provided in the inner tube portion. .

(2) In each of the above embodiments, the pipe joint 22
By connecting the EGR passage of the EGR device to the intake passage 14, EGR gas is introduced into the intake passage 14 as a gas other than the outside air. On the other hand, by connecting the blow-by passage of the blow-by reduction device to the pipe joint, the blow-by gas may be introduced into the intake passage as a gas other than the outside air.

[0038]

According to the first aspect of the present invention,
The valve shaft can be stably supported without increasing the intake resistance by the bearing, and the effect that the gas other than the outside air can be evenly mixed with the outside air is exhibited.

According to the structure of the invention described in claim 2, in addition to the effect of the invention described in claim 1, gas other than the outside air does not enter the gap between the first bearing and the valve shaft. It is possible to prevent the first bearing and the valve shaft from sticking to each other due to fine foreign matter contained in the gas. together,
By providing the atmosphere passage, it is possible to minimize an increase in intake resistance in the intake passage.

According to the configuration of the third aspect of the invention, the same effect as that of the second aspect of the invention can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a series of intake manifolds, a gas introduction device, and a throttle body according to a first embodiment.

FIG. 2 is a cross-sectional view taken along the line 2-2 in FIG.

FIG. 3 is a cross-sectional view showing a series of intake manifolds, a gas introduction device, and a throttle body according to a second embodiment.

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is a sectional view showing a conventional gas introduction device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Gas introduction apparatus 14 Intake passage 17 Inner pipe part 18 Outer pipe part 19 Gap 21 Inlet 23a Inlet 23b Inlet 31 Valve seat 32 Valve 33 Valve shaft 34 Actuator 36 First bearing 37 Second bearing 38 Gap 39 Gap 40 Sleeve 41 Gap 42 Gas introduction device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masahiro Kobayashi 1-1-1, Kyowa-cho, Obu City, Aichi Prefecture Inside Aisan Industry Co., Ltd. (72) Inventor Natsuhiko Katahira 1-Toyota Town, Toyota City, Aichi Prefecture Toyota (72) Inventor Yoshiaki Seino 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F-term (reference) 3G062 BA01 EA10 ED05 ED15

Claims (3)

[Claims] 1. A gas introduction device for introducing a gas other than the outside air into an intake passage for flowing outside air, wherein the gas introduction device is arranged with a predetermined gap on an outer periphery of the inner tube portion and a predetermined gap. An outer pipe portion, an inlet provided in the outer pipe portion for introducing a gas other than the outside air into the gap, and an inner port for introducing the gas introduced into the gap into the intake passage. An introduction hole provided at a position not opposed to the introduction port of the pipe portion, a valve seat provided corresponding to the introduction port, a valve body provided corresponding to the valve seat, and the valve body A valve shaft extending and penetrating the inner pipe portion and the outer pipe portion in a direction orthogonal to the intake passage; provided on the outer pipe portion on the opposite side to the arrangement of the introduction port, via the valve shaft; An actuator for driving the valve body, and a front end for supporting one end of the valve shaft. A first bearing provided in the inner pipe at a position adjacent to the inlet; and an inner pipe and an outer pipe at a position adjacent to the actuator to support the other end of the valve shaft. And a second bearing provided on at least one of the above. 2. The intake passage according to claim 1, wherein an air passage is provided along the valve shaft to allow a gap between the first bearing and the valve shaft to communicate with the atmosphere. Gas introduction device. 3. The air intake according to claim 2, wherein the air passage includes a gap between a sleeve provided in the inner pipe portion so as to include the valve shaft and the valve shaft. Gas introduction device for passage.