JP2002004961A - Gas mixture system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas mixture system capable of promoting mixing of main gas and sub gas. SOLUTION: This gas mixture system has a sub gas passage C communicating with the downstream side than a throttle valve SRV to guide the sub gas into a main gas passage T. Two openings 1 and 2 are provided at separating positions along the longitudinal (Y direction) downstream side of the main gas passage (an inside pipe IP) from two intersection points P1 and P2 between straight line X vertical to both a throttle axis Z and the longitudinal direction Y of the main gas passage T at a throttle axis Z and a passage inner wall. The sub gas passage C communicates with the main gas passage T through the openings 1 and 2. A circumferential length of the first opening 1 defined by θ1 is shorter than a circumferential length of the second opening 2 defined by θ2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gas mixing system for mixing a main gas such as fresh air and a sub-gas such as exhaust gas downstream of a valve such as a throttle valve.

[0002]

2. Description of the Related Art Conventionally, as a gas recirculation device, a proby gas recirculation device that recirculates proby gas through a positive crank ventilation (PCV) valve, an exhaust gas recirculation (EGR) device that recirculates engine exhaust gas, and a canister And the like are known.

[0003] A device for recirculating gas to an engine is described, for example, in Japanese Patent Application Laid-Open No. H11-210560. Assuming that the fresh air is the main gas and the exhaust gas is the sub-gas, in this publication, a throttle valve rotatable around an axis crossing the inner wall of the main gas passage through which the main gas passes, and a sub- A gas mixing system including a sub-gas passage communicating with a downstream side of a throttle valve for introducing gas is disclosed.

[0004] These mixed gases are introduced into the surge tank above the intake manifold (branch pipe), and then into each cylinder of the engine via the branch pipe.
A backflow region where an airflow vortex is formed exists on the downstream side of the throttle valve, but if a sub-gas containing oil or the like is introduced into the backflow region, oil will adhere to the throttle valve.
Therefore, in this publication, the auxiliary gas is introduced into the main gas passage avoiding the backflow region.

[0005]

However, in the conventional gas mixing system, the mixing of the main gas and the sub-gas is not promoted because the sub-gas is merely introduced in the circumferential tangential direction of the main gas passage. The present invention has been made in view of such a problem, and an object of the present invention is to provide a gas mixing system capable of promoting mixing of a main gas and a sub gas.

[0006]

According to a first aspect of the present invention, there is provided a valve which is rotatable about an axis crossing an inner wall of a main gas passage through which a main gas passes. In a gas mixing system comprising a sub-gas passage communicating downstream of the valve to introduce a sub-gas into the shaft, a straight line and an inner wall perpendicular to both the longitudinal direction of the main gas passage at the position of the shaft and the shaft. First and second openings are provided at positions separated from the two intersections along the downstream side in the longitudinal direction of the main gas passage, and the sub-gas passage is connected to the main gas passage via the first and second openings. It is characterized in that it is communicated with. In the present invention, since two openings are provided at specific positions with respect to the rotation axis of the valve, mixing of the main gas and the sub gas can be promoted.

According to a second aspect of the present invention, in the first aspect of the invention, the first and second openings are each separated from a portion of the first and second openings which is located farthest from the axis. The one where the shortest distance to the valve is farthest is the first opening, and the length of the first opening along the circumferential direction of the main gas passage is the circumferential direction of the main gas passage of the second opening. Characterized by being shorter than the length along. In the present invention, mixing of the main gas and the sub gas can be promoted by setting the length of each opening in the circumferential direction as described above in accordance with the state in which the valve rotates and tilts.

[0008] In a third aspect based on the second aspect,
The shape of the main gas passage along the circumferential direction is a circle,
The length of the opening along the circumferential direction of the main gas passage is defined by a first arc, and the length of the second opening along the circumferential direction of the main gas passage is defined by a second arc. The angle between the two radii defining the first arc is 10 degrees or more and 60 degrees or more.
Degrees or less, and an angle formed by two radii defining the second arc is 30 degrees or more and 160 degrees or less. In the present invention, the mixing of the main gas and the sub gas can be promoted, and the introduction of the sub gas into the reverse flow region formed downstream of the valve can be suppressed.

In a fourth aspect based on the third aspect,
The angle between the two radii defining the first arc is 20.
Not less than 40 degrees and not more than 40 degrees to define the second arc.
The angle formed by the two radii is not less than 45 degrees and not more than 90 degrees. In the present invention, the mixing of the main gas and the sub gas can be further promoted.

According to a fifth aspect of the present invention, the length of the first opening along the longitudinal direction of the main gas passage is longer than the length of the second opening along the longitudinal direction of the main gas passage. It is characterized by. In the present invention, the mixing of the main gas and the sub-gas can be further promoted, and the introduction of the sub-gas into the backflow region formed downstream of the valve can be suppressed.

According to a sixth aspect of the present invention, the length of the first opening along the longitudinal direction of the main gas passage is three times the length of the second opening along the longitudinal direction of the main gas passage. It is characterized by the above. In the present invention, since the range is set as described above, the above-described mixing and suppression can be reliably performed.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the main gas passage has an inner diameter adjacent to the downstream side of the first and second openings, the inner diameter being located at the upstream side. A small-diameter portion that is set smaller than the adjacent inner diameter, and a transfer portion that connects the small-diameter portion and the first and second openings and has an inner diameter that gradually decreases toward the downstream side. It is characterized by having. In the present invention, since the gas is easily separated from the inner surface of the main gas passage, a temperature change in the main gas passage,
When the sub-gas has high heat, it is possible to suppress the temperature rise.

According to an eighth aspect, in the seventh aspect,
The angle formed by the plane perpendicular to the longitudinal direction of the main gas passage and the inner surface of the transition portion from the upstream side to the downstream side is 30 degrees or more and 6 degrees or more.
It is characterized by being less than 0 degrees. In the present invention,
Since the range is set as described above, the temperature change can be more reliably suppressed in addition to the above-described promotion of gas mixing and suppression of introduction into the backflow region.

According to a ninth aspect, in any one of the first to eighth aspects, the main gas passage is expanded downstream of the first and second openings so as to increase the diameter of the main gas passage. It is characterized by having a step formed along the circumferential direction of the gas passage. In the present invention, since a vortex is generated at the step, the mixing of the gas can be further promoted, and the temperature change of the main gas passage can be suppressed.

In a tenth aspect based on the ninth aspect, the step is formed by connecting a pipe or a ring-shaped member to the main gas passage so as to enlarge the diameter of the main gas passage. And According to the present invention, the steps can be easily and reliably formed.

According to an eleventh aspect, in the first to tenth aspects, the second opening is divided into a plurality of openings by being locally closed. In the present invention, since the main gas flows directly into the closed portion of the second opening, the influence of the temperature of the main gas is increased more than the sub gas, and when the sub gas is at a high temperature, its temperature rises. Can be suppressed.

According to a twelfth aspect, in any one of the first to eleventh aspects, the auxiliary gas introduced into the main gas passage from the first and / or second openings is provided. And a shielding member provided at a position capable of suppressing direct contact with the inner surface of the main gas passage located downstream of the first and / or second opening. In the present invention, since the shielding member is provided at a position capable of suppressing direct contact of the sub gas with the inner surface of the main gas passage,
It is possible to suppress a change in the temperature of the main gas passage due to the auxiliary gas.

According to a thirteenth aspect, in the twelfth aspect, the shielding member is a heat radiating plate made of metal. In the present invention, when the auxiliary gas hits the shielding member, the heat is transmitted to the shielding member, and therefore, the influence of the heat of the auxiliary gas can be reduced.

In a fourteenth aspect based on the thirteenth aspect, the radiator plate traverses an opposing portion of an inner surface of the main gas passage, and a surface of the radiator plate is parallel to an axis of the valve. It is characterized by the following. In this case, since the heat radiating plate is arranged so as to divide between the first and second openings, the auxiliary gas introduced through one of the openings hits the opposing inner surface in the main gas passage. Can be suppressed, and a temperature rise accompanying this can be suppressed.

According to a fifteenth aspect, in any one of the first to eleventh aspects, a radiation fin made of metal is fixed to an inner surface of the main gas passage downstream of the first and second openings. The radiating fins are provided at positions that do not intersect a plane including the tube axis of the main gas passage and passing through the center of the first or second opening. In the plane including the center, the influence of the temperature of the auxiliary gas is strong, and when the temperature is high, the temperature of the radiation fin rises.In the present invention, however, the radiation fin is located at a position not intersecting with the plane. Since it is provided, the radiation fins are less likely to be directly affected by the auxiliary gas temperature, and the main gas and the mixed gas of the main gas and the auxiliary gas can be efficiently cooled.

In a sixteenth aspect based on the first aspect, the first and second openings define an opening in the inner tube of the inner tube and the outer tube arranged coaxially, and the first and second openings are formed in the inner tube. The outer pipe and the outer pipe are formed by closing the gap between both ends in the longitudinal direction and the inner surface of the outer pipe so that the auxiliary gas can be introduced from the auxiliary gas passage through the first and second openings. The main gas passage includes an inner surface of the inner tube and an inner surface of the outer tube downstream of the inner tube. According to the present invention, the first
In addition, the second opening can be easily formed.

According to a seventeenth aspect of the present invention, there is provided a valve rotatable around an axis crossing an inner wall of a main gas passage through which a main gas passes, and a downstream side of the valve for introducing a sub-gas into the main gas passage. A gas mixing system comprising: a sub-gas passage communicating with the inner gas passage; and a line perpendicular to both the axis and the longitudinal direction of the main gas passage at the position of the axis and one of two intersections of the inner wall. A first opening is provided at a position separated along the downstream side in the longitudinal direction of the main gas passage, and the sub gas passage communicates with the main gas passage through the first opening, and the main gas passage The shape along the circumferential direction of is a circle,
The length of the first opening along the circumferential direction of the main gas passage is defined by a first arc, and 2 defines the first arc.
The angle formed by the two radii is not less than 10 degrees and not more than 60 degrees. In the present invention, only the first opening is defined, but also in this case, when the first opening is provided at the above-mentioned position and the length in the circumferential direction is defined by the above-mentioned angle, Gas mixing can be promoted.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A gas mixing system according to an embodiment will be described below by taking an exhaust gas recirculation (EGR) device of an internal combustion engine as an example. In the description, the same elements will be denoted by the same reference characters, without redundant description.

FIG. 1 shows an EG located around the engine E.
It is a perspective view of an R apparatus. Exhaust gas (sub-gas) discharged from the engine E is introduced into the gas mixing device GM via the EGR pipe P and the EGR valve V. An intake pipe AIT is also connected to the gas mixing device GM, and fresh air (main gas) is introduced into the gas mixing device GM via the intake pipe AIT.

In the gas mixing device GM, the main gas and the sub-gas are mixed, and this mixed gas flows into the surge tank S, and thereafter, into each cylinder of the engine E via the branch pipe (intake manifold) M. Inhaled. The system or method for forming a series of gas flows constitutes a gas mixing system. The surge tank S can be omitted depending on the design.

The throttle body BDY of the intake pipe AIT
A throttle valve SRV is provided therein, and the throttle valve SRV regulates the amount of fresh air supplied to the branch pipe M. In the description, a gas path from the intake pipe AIT to the branch pipe M via the gas mixing device GM is referred to as a “main gas passage”. Also, the gas mixing device G
The gas path leading to M is referred to as a “sub gas path”.

FIG. 2 is a perspective view of the gas mixing device GM.
A substantially cylindrical EGR adapter device AD is provided downstream of the throttle valve SRV, and the adapter device AD communicates with the surge tank S or the intake manifold M via a resin spacer RS. Adapter device A
The main gas is introduced into D from the intake pipe AIT along the axial direction Y, and the sub-gas is introduced from the two openings 1 and 2 along the radial direction of the adapter device AD. In addition,
The sub-gas flowing from the EGR pipe P shown in FIG.
Adapter device AD via EGR valve V and connection pipe C
Flows into the openings 1 and 2.

The throttle valve SRV can rotate around the throttle axis Z, and the rotation changes the supply amount of the main gas to the adapter device AD. Throttle axis Z
Extends substantially vertically.

FIG. 3 is a sectional view taken along a line III-III of the gas mixing device GM shown in FIG. 2 when the adapter device AD of the gas mixing device GM is cut along a plane perpendicular to the Y axis. FIG. 4 shows FIG.
The gas mixing device GM shown in (1) is formed by two planes parallel to the Y axis which are bent at the center axis of the adapter device AD.
And the IV of the device cut to include the center of the connecting pipe C
FIG. 4 is a sectional view taken along a line IV-IV.

The inner tube IP and the outer tube OP arranged coaxially
Of these, the openings (slits) 1 and 2 are formed in the inner tube IP, and the first and second are closed by closing between the both ends in the longitudinal direction (Y-axis direction) of the inner tube IP and the inner surface of the outer tube OP.
Openings 1 and 2 are formed. First and second openings 1, 2
The outer pipe OP and the auxiliary gas path are communicated with each other so that the auxiliary gas can be introduced from the auxiliary gas path (connection pipe C) via the inner pipe, and the main gas path is formed on the inner surface of the inner pipe IP and the outer pipe downstream of the inner pipe IP. Includes the inner surface of the OP. According to this method, the first and second openings 1 and 2 can be easily formed.

The present apparatus has a valve (throttle valve) SRV rotatable around an axis Z that passes through the inner wall of the main gas passage through which the main gas passes, and a throttle valve SRV for introducing a sub-gas into the main gas passage. In a gas mixing system having a sub-gas passage communicating with the downstream side, a straight line X perpendicular to both the axis Z and the longitudinal direction Y of the main gas passage at the position of the axis Z
First and second openings 1 and 2 are provided at positions separated from _two intersections P ₁ and P ₂ of the main gas passage (inner pipe IP) along the downstream side in the longitudinal direction (Y direction) of the main gas passage (inner pipe IP). The auxiliary gas passage communicates with the main gas passage via the first and second openings 1 and 2.

In the present apparatus, since two openings 1 and 2 are provided at specific positions with respect to the rotation axis Z of the throttle valve SRV, the mixing of the main gas and the sub gas can be promoted. The principle of mixing these will be described later.

The shortest distance from each of the first and second openings 1 and 2 located farthest from the axis Z of the first and second openings 1 and 2 to the throttle valve SRV is greater. (The left opening in FIG. 4) is referred to as a first opening 1. The length (L1) along the circumferential direction of the main gas passage of the first opening 1 defined by θ1 in FIG. 3 is equal to the length in the circumferential direction of the main gas passage of the second opening 2 defined by θ2. It is shorter than the length along the line (L2).

In the present apparatus, the length of each of the openings 1 and 2 is set in the circumferential direction as described above in accordance with the state in which the throttle valve SRV is tilted by rotation, so that the main gas and the sub gas are Mixing can be promoted.

More specifically, the shape of the main gas passage (inner pipe IP) along the circumferential direction is a circle, and the length L1 of the first opening 1 along the circumferential direction of the main gas passage is the first arc. And the length L along the circumferential direction of the main gas passage of the second opening 2
2 is defined by the second arc, and the angle θ1 formed by the two radii r11 and r12 defining the first arc is 10 degrees or more and 60 degrees or more.
Degrees, and two radii r2 defining the second arc
1, the angle θ2 formed by r22 is 30 degrees or more and 160 degrees or less.

In the present device, the mixing of the main gas and the sub gas can be promoted, and the introduction of the sub gas into the reverse flow region formed downstream of the throttle valve SRV can be suppressed.

The angle θ1 formed by the two radii r11 and r12 defining the first arc is not less than 20 degrees and not more than 40 degrees, and the two radii r21 and r defining the second arc.
22 is more preferably 45 degrees or more and 90 degrees or less. Within this range, the mixing of the main gas and the sub gas can be further promoted.

Here, the principle of promoting the gas mixing by setting the above-mentioned shape, position and range, and suppressing the advance of the auxiliary gas to the backflow region will be described.

FIG. 5 is an explanatory view of a gas passage near the main gas passage T including the inner pipe IP. FIG. 6 is an explanatory diagram showing the distribution of gas flowing in the Y direction in a plane perpendicular to the tube axis Y of the main gas passage in the same manner as in FIG. FIG. 7 is an explanatory view showing the distribution of gas flowing in the Y direction in a plane parallel to the pipe axis Y of the main gas passage in the same manner as in FIG. FIG. 8 shows FIG.
It is explanatory drawing which shows the distribution of the gas which flows in the XZ plane in the plane perpendicular | vertical to the pipe axis Y of the main gas passage in the same format as FIG. Although the forward flow velocity of the gas is as shown in the figure,
In FIG. 7, the side of the throttle valve SRV that opens in the negative Y-axis direction is large.

Downstream of the throttle valve SRV shown in FIG. 5, gas flows from the downstream side to the throttle valve SRV side in the portion shown by the reverse flow region in FIGS. The downstream region except the backflow region has a short length on the first opening 1 side and a long length on the second opening 2 side, when considering around the Y axis (circumferential direction). Also, considering in a plane parallel to the Y axis, the first
On the opening 1 side, the length is long and the second opening 2
On the side, its length is short. By flowing the sub-gas from the direction perpendicular to the throttle axis Z into this forward flow region, it is possible to promote the mixing with the main gas while suppressing the back flow of the sub-gas in the direction of the throttle valve SRV. Also, considering the components of the airflow, as shown in FIG. 8, fresh air (main gas) flows from the second opening 2 to the first opening 1 along the inner wall of the inner pipe IP, avoiding the opening.

Therefore, by providing the first and second openings 1 and 2 at the above-mentioned positions, the sub-gas is less likely to proceed to the reverse flow region, and the sub-gas is drawn into the forward flow region with a fast flow. Is promoted. By avoiding the backflow of the sub-gas, the adhesion of oil and the like contained in the sub-gas to the throttle valve SRV is suppressed.

Referring to FIG. 6, the gas inflow portion A of the sub-gas defined by the first opening 1 has an angle θ1 (see FIG. 3) of about 60 degrees so that the sub-gas flows forward. The gas inlet B of the sub gas defined by the second opening 2 has an angle θ2 so that the sub gas flows in the forward flow.
(See FIG. 3) was set to about 160 degrees or less, and the range was defined as described above in consideration of these probability errors and optimum values. , Angles θ1 and θ2 are 30 degrees and 70 degrees, respectively.

Further, the auxiliary gas has a higher heat than the main gas. The secondary gas is introduced in the radial direction of the main gas passage.
In addition, since both ends of the inner pipe IP other than the second openings 1 and 2 are closed, a rise in temperature of the main gas passage wall surface due to the auxiliary gas is suppressed, and a relatively low-temperature main gas flows through this closed region. FIG. 8), the temperature rise of the entire wall surface can be suppressed.

If the amount of heat transmitted to the wall surface when the auxiliary gas is introduced uniformly is Q, the area is S, and the flow rate is U, the closed area is a × 100% of the whole.
In general, the amount of heat transfer is substantially proportional to the area and the flow velocity. Therefore, when the above-mentioned closed region is not provided, c is a constant and Q
= C × S × U. On the other hand, when the closed area is provided, the heat transfer amount Q ′ is Q ′ = c × (1−a) S × U /
(1-a) = c × S × U = Q, and the amount of heat transfer from the gas does not change due to blockage. However, by providing the closed area, the relatively low-temperature main gas (fresh air) hits the wall surface, so that the wall surface is cooled by that much. By performing such cooling, parts with low heat-resistant temperature,
For example, the above-described resin spacer RS (see FIG. 2) can be used.

As described above, when considered in a plane parallel to the Y axis, the downstream region has a longer length on the first opening 1 side and a longer length on the second opening 2 side. Was short.

However, in this embodiment, the length H1 of the first opening 1 along the longitudinal direction Y of the main gas passage is equal to the length H2 of the main opening of the second opening 2 along the longitudinal direction Y.
(See FIG. 4). Even in such a case, a certain effect is expected as described above, but it is preferable to make these different.

Next, a description will be given of a detailed configuration of the apparatus applied in the above-mentioned example, with the improved lengths H1 and H2 as the optimum embodiment. In the following, the configuration that is not particularly described is the same as the above-described example. Further, the detailed configuration and improvements of the device described below are applicable to any of the above and below examples unless otherwise specified. Also, each improvement can be combined. The details are described below.

FIG. 9 is a cross-sectional view of the gas mixing device GM shown in the same form as FIG. FIG. 10 is an explanatory diagram of a gas passage near the main gas passage T including the inner tube IP. In this example, the length H1 of the first opening 1 along the longitudinal direction Y of the main gas passage T is equal to the length Y of the main gas passage T of the second opening 2 in the longitudinal direction Y.
Is longer than the length H2 along. In this case, since the auxiliary gas is efficiently loaded in the forward flow region, the mixing of the main gas and the auxiliary gas is further promoted, and the introduction of the auxiliary gas into the reverse flow region formed downstream of the throttle valve SRV is suppressed. it can.

Here, the length H1 of the first opening 1 along the longitudinal direction Y of the main gas passage T is 3 times the length H2 of the second opening 2 along the longitudinal direction Y of the main gas passage T. More than double.
From the results of simulation based on CFD (computational fluid dynamics), it has been found that by setting the range in this way, the above-described mixing and suppression can be reliably performed.

Note that, on the downstream side of the opening, a transition portion TF having an inner diameter gradually reduced and a small-diameter portion ND having a smaller inner diameter are sequentially located adjacent to the opening, which serve as a cooling portion (heat receiving portion). Constitute.

FIG. 11 shows a gas mixing device G of the same type as FIG.
It is explanatory drawing of the said apparatus which shows the cross-section of M. FIG.
FIG. 13 is an explanatory diagram for extracting only the adapter device AD from FIG. 11 and describing the angle θ of the transition portion TF.
FIG. 13 shows the angle θ, the temperature of the main gas passage T, and the transition portion TF.
It is a graph which shows the auxiliary gas concentration of the vicinity.

The main gas passage is T, the first and second openings 1,
The small-diameter portion ND whose inner diameter adjacent to the downstream side of the second portion is smaller than the inner diameter adjacent to the upstream side connects the small-diameter portion ND with the first and second openings 1 and 2. And a transition portion TF whose inner diameter gradually decreases toward the downstream side.

In this case, since the gas is easily separated from the inner surface of the main gas passage T, the temperature change in the main gas passage T, that is, the sub-gas has high heat, so that the temperature rise can be suppressed. . Also, from the viewpoint of preventing oil adhesion,
It is preferable that the concentration of the auxiliary gas is also low. Therefore, it is preferable that the angle θ formed by the plane perpendicular to the longitudinal direction Y of the main gas passage T and the inner surface of the transition portion TF from the upstream side to the downstream side is 30 degrees or more and 60 degrees or less. In the present invention, since the range is set as described above, in addition to the above-described promotion of gas mixing and suppression of introduction into the backflow region, it is possible to more reliably perform temperature change and suppression of concentration increase. Note that the optimal value of θ is 45 degrees.

The step ST is located downstream of the small diameter portion ND.
P is provided.

FIG. 14 is an explanatory view of the gas mixing device GM in the same form as that of FIG. FIG.
FIG. 15 is an explanatory diagram for extracting only the step STP shown in the circle CIR from FIG. 14 and describing the angle θ of the transition portion TF.

In the present device, a step S formed along the circumferential direction of the main gas passage T so as to enlarge the diameter of the main gas passage T downstream of the first and second openings 1 and 2.
Has TP. Since the vortex is generated at the step STP, the mixing of the gas can be further promoted, and the temperature rise of the main gas passage T can be suppressed. The sub-gas flows from the upstream side of the step STP as a high-temperature gas, but the temperature gradually decreases as it passes through the transition portion TF and the small-diameter portion ND, and swirls at the step STP.

Since the main gas (fresh air) having a relatively low temperature is mixed from this position in the circumferential direction, an air layer is formed at the step STP portion, and the high-temperature gas contacts at high temperature only at the step STP. Downstream of the resin spacer RS
Is located at the step STP, it is also possible to suppress the temperature rise. The resin spacer RS may be replaced with a metal spacer or a metal gasket ring.

The step STP is formed by connecting a pipe or a ring-shaped member RS or S to the main gas passage T so as to enlarge the diameter of the main gas passage T. Therefore, according to this example, the step STP can be easily and reliably formed.

The second opening 2 may be modified so that it is divided into a plurality of openings by being locally closed.

FIG. 16 is a cross-sectional view of the device with such an improvement in the same form as that of FIG. In the present apparatus, the main gas directly flows through the closed portion of the second opening 2, so that the influence of the temperature of the main gas is greater than that of the sub gas. Since the auxiliary gas is at a high temperature and the main gas is at a low temperature, it is possible to suppress an increase in the temperature of the closed portion.

Further, a shielding member for suppressing the radial flow of the auxiliary gas may be arranged downstream of the first and second openings 1 and 2.

FIG. 17 is a cross-sectional view of the device with such an improvement in the same form as that of FIG. In addition,
The position of the cross section is downstream of the openings 1 and 2. FIG. 18 is an explanatory diagram showing the cross-sectional configuration of the device shown in FIG. 17 in the same format as that of FIG.

The shielding member SLD is provided with the first and / or second openings 1 and / or 2 for the auxiliary gas introduced into the main gas passage IP (T) from the first and / or second openings 1 and 2. It is provided at a position where direct contact with the inner surface of the main gas passage OP (T) located downstream of the main gas passage OP can be suppressed.

In this device, since the shielding member SLD is provided at a position where the direct contact of the sub-gas with the inner surface of the main gas passage OP (T) can be suppressed, the temperature change of the main gas passage due to the sub-gas, That is, a rise in temperature can be suppressed.

In addition, the shielding member SLD is a heat radiating plate made of metal. When the auxiliary gas hits the shielding member SLD, the heat is transmitted to the shielding member SLD.
The effect of the heat of the auxiliary gas can be further reduced.

The heat radiating plate SLD traverses the opposed portion of the inner surface of the main gas passage OP (T), and the surface of the heat radiating plate SLD is parallel to the throttle axis Z. In this case, since the heat sink SLD is arranged so as to divide the first and second openings 1 and 2, the sub-gas introduced through one of the openings 1 and 2 is the main gas. It is possible to suppress the contact with the opposing inner surface in the passage T, and it is possible to suppress a rise in temperature accompanying this.

Further, a radiation fin may be arranged in the main gas passage T.

FIG. 19 is a cross-sectional view of a device having such an improvement in the same form as that of FIG. FIG.
0 is an explanatory diagram showing the cross-sectional configuration of the device shown in FIG. 19 in the same format as that of FIG.

In this device, a radiating fin F made of metal is fixed to the inner surface of the main gas passage OP (T) on the downstream side of the first and second openings 1 and 2, and the radiating fin F is connected to the main gas passage. It is provided at a position that does not intersect with a plane that includes the tube axis Y of OP (T) and passes through the center of the first or second opening 1 or 2.

In the plane including the center, the influence of the temperature of the auxiliary gas is strong and the temperature of the radiation fins F rises because of the high heat. Is provided with the radiation fins F, the radiation fins F are less likely to be directly affected by the auxiliary gas temperature, and the main gas and the mixed gas of the main gas and the auxiliary gas can be efficiently cooled.

A gas mixing device GM having only the first opening 1 is also proposed.

FIG. 21 is an explanatory view of the gas mixing device GM, showing a cross-sectional structure of the same device as that of FIG. FIG. 22 is an explanatory diagram showing the cross-sectional configuration of the device shown in FIG. 21 in the same format as FIG.

In the present apparatus, a throttle valve SRV rotatable around an axis crossing the inner wall of the main gas passage T through which the main gas passes, and a throttle valve SRV for introducing a sub-gas into the main gas passage T. In a gas mixing system having a sub-gas passage communicating with the downstream side, a straight line X perpendicular to both the throttle axis Z and the longitudinal direction Y of the main gas passage T at the position of the throttle axis Z and the inner wall are provided. A first opening 1 is provided at a position separated from one of the intersections P1 and P2 along the downstream side of the main gas passage T in the longitudinal direction, and the sub gas passage is connected to the main gas passage via the first opening 1. The main gas passage T communicates with the passage, the shape along the circumferential direction of the main gas passage T is a circle, and the length of the first opening 1 along the circumferential direction of the main gas passage T is defined by a first arc, Angle between two radii defining the first arc θ1, similar to that described above, 1
0 degrees or more and 60 degrees or less. Further, the second opening 2 described in the above example is closed.

In the present apparatus, only the first opening 1 is defined. In this case as well, the first opening 1 is provided at the above position, and the circumferential length thereof is defined by the angle θ1. In such a case, mixing of the above gases can be promoted.

[0075]

As described above, in the gas mixing system of the present invention, the mixing of the main gas and the sub gas can be promoted.

[Brief description of the drawings]

FIG. 1 is a perspective view of an EGR device located around an engine E. FIG.

FIG. 2 is a perspective view of a gas mixing device GM.

FIG. 3 is a sectional view of the gas mixing device GM shown in FIG.
It is II arrow line sectional drawing.

FIG. 4 shows the gas mixing device GM shown in FIG. 2 cut along two planes parallel to the Y axis bent at the central axis of the adapter device AD so as to include the openings 1, 2 and the center of the connecting pipe C. FIG. 4 is a sectional view taken along the line IV-IV of the device.

FIG. 5 is an explanatory diagram of a gas passage near a main gas passage T including an inner pipe IP.

FIG. 6 is an explanatory diagram showing the distribution of gas flowing in the Y direction in a plane perpendicular to the tube axis Y of the main gas passage in the same manner as in FIG. 3;

FIG. 7 is an explanatory diagram showing the distribution of gas flowing in the Y direction in a plane parallel to the tube axis Y of the main gas passage in the same manner as in FIG.

FIG. 8 is an explanatory diagram showing a distribution of gas flowing in an XZ plane in a plane perpendicular to the tube axis Y of the main gas passage in the same form as in FIG. 3;

FIG. 9 is a cross-sectional view of the gas mixing device GM shown in the same form as FIG.

FIG. 10 is an explanatory diagram of a gas passage near a main gas passage T including an inner pipe IP.

FIG. 11 is an explanatory view of the gas mixing device GM in the same form as FIG.

12 is an explanatory diagram for extracting only the adapter device AD from FIG. 11 and describing the angle θ of the transition portion TF.

FIG. 13 shows the angle θ, the temperature of the main gas passage T, and the transition portion TF.
It is a graph which shows the auxiliary gas concentration of the vicinity.

FIG. 14 is an explanatory view of the gas mixing device GM in the same form as FIG.

FIG. 15 shows only the step STP shown in the circle CIR in FIG.
FIG. 4 is an explanatory diagram extracted from FIG. 4 and illustrating an angle θ of a transition portion TF.

FIG. 16 is a sectional view of the improved device in the same form as FIG. 3;

17 is a sectional view of the improved device in the same form as FIG. 3; FIG.

18 is an explanatory diagram showing a cross-sectional configuration of the device shown in FIG. 17 in the same format as FIG.

FIG. 19 is a cross-sectional view of the improved device in the same form as FIG. 17;

20 is an explanatory diagram showing the cross-sectional configuration of the device shown in FIG. 19 in the same format as that of FIG. 18;

21 is an explanatory view of the gas mixing device GM, showing the cross-sectional configuration of the device in the same format as that of FIG.

FIG. 22 is an explanatory diagram showing a cross-sectional configuration of the device shown in FIG. 21 in the same format as FIG.

[Explanation of symbols]

1, 2, opening, A: gas inlet, AD: adapter device, AIT: intake pipe, B: gas inlet, BDY: throttle body, C: connecting pipe (sub gas passage), CIR:
Circle, E: Engine, F: Radiation fin, GM: Gas mixing device, IP: Inner tube (main gas passage), M: Intake manifold, ND: Small diameter portion, OP: Outer tube, P: Pipe,
P _1, P ₂ ... intersections, RS ... resin spacer, S ... surge tank, SLD ... shielding member (heat radiation plate), SRV ... throttle valve, STP ... step, T ... primary gas passage, TF ... metastases, V
... Valve, Z ... Throttle shaft.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02M 25/08 F02M 25/08 N (72) Inventor Kuniaki Muramatsu 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto 3G044 AA04 BA11 GA21 3G062 ED04 ED15

Claims (17)

[Claims] 1. A valve rotatable around an axis crossing an inner wall of a main gas passage through which a main gas passes, and a sub-flow passage connected downstream from the valve to introduce a sub-gas into the main gas passage. In a gas mixing system comprising a gas passage, the axis and a straight line perpendicular to both the longitudinal direction of the main gas passage at the position of the axis and two intersections between the inner wall and the longitudinally downstream side of the main gas passage from the two intersections. A gas mixing system, wherein first and second openings are provided at positions spaced apart from each other, and the auxiliary gas passage communicates with the main gas passage via the first and second openings. . 2. The one of the first and second openings, in which the shortest distance from each of the first and second openings located farthest from the axis to the valve is the first one. An opening, wherein the length of the first opening along the circumferential direction of the main gas passage is shorter than the length of the second opening along the circumferential direction of the main gas passage. Item 2. A gas mixture system according to Item 1. 3. The shape of the main gas passage along the circumferential direction is a circle, and the length of the first opening along the circumferential direction of the main gas passage is defined by a first circular arc. The length of the two openings along the circumferential direction of the main gas passage is defined by a second arc, and an angle formed by two radii that define the first arc is not less than 10 degrees and not more than 60 degrees, The gas mixing system according to claim 2, wherein an angle formed by the two radii defining the second arc is not less than 30 degrees and not more than 160 degrees. 4. An angle formed by two radii defining the first arc is not less than 20 degrees and not more than 40 degrees, and an angle formed by two radii defining the second arc is not less than 45 degrees and not more than 90 degrees. The gas mixing system according to claim 3, wherein 5. A length of the first opening along the longitudinal direction of the main gas passage is longer than a length of the second opening along the longitudinal direction of the main gas passage. The gas mixing system according to claim 2. 6. The length of the first opening along the length of the main gas passage is at least three times the length of the second opening along the length of the main gas passage. The gas mixing system according to claim 5, characterized in that: 7. The small-diameter portion wherein the inner diameter adjacent to the first and second openings on the downstream side is set smaller than the inner diameter adjacent to the upstream side. 7. A transition part which connects between the first and second openings and has a transition part whose inner diameter gradually decreases toward the downstream side. Gas mixing system. 8. An angle between a plane perpendicular to a longitudinal direction of the main gas passage and an inner surface of the transition portion from an upstream side to a downstream side is 30 degrees or more and 60 degrees or less. A gas mixture system according to the above. 9. A step formed at a downstream side of the first and second openings along a circumferential direction of the main gas passage so as to enlarge a diameter of the main gas passage. The gas mixture system according to claim 1. 10. The gas mixing system according to claim 9, wherein the step is formed by connecting a pipe or a ring-shaped member to the main gas passage so as to enlarge the diameter of the main gas passage. . 11. The gas mixing system according to claim 1, wherein the second opening is divided into a plurality of openings by being locally closed. 12. The sub-gas introduced into the main gas passage from the first and / or second opening in a downstream side of the first and / or second opening. A shielding member provided at a position where direct contact with the inner surface of the main gas passage can be suppressed is provided.
The gas mixture system according to any one of claims 1 to 7. 13. The gas mixing system according to claim 12, wherein the shielding member is a heat sink made of metal. 14. The radiator plate according to claim 13, wherein the radiator plate traverses an opposing portion of an inner surface of the main gas passage, and a surface of the radiator plate is parallel to an axis of the valve. Gas mixing system. 15. A heat radiation fin made of metal is fixed to an inner surface of the main gas passage downstream of the first and second openings, and the heat radiation fin includes a tube axis of the main gas passage. The gas mixture system according to any one of claims 1 to 11, wherein the gas mixture system is provided at a position that does not intersect a plane passing through the center of the second opening. 16. The first and second openings form openings in the inner tube of the inner tube and the outer tube coaxially arranged, and both ends in the longitudinal direction of the inner tube and the inner surface of the outer tube. The outer pipe and the sub-gas passage are formed so as to be able to introduce the sub-gas from the sub-gas passage through the first and second openings. The gas mixing system according to claim 1, wherein the main gas passage includes an inner surface of the inner tube and an inner surface of the outer tube downstream of the inner tube. 17. A valve rotatable about an axis transverse to an inner wall of a main gas passage through which a main gas passes, and a sub-portion communicating downstream from the valve to introduce a sub-gas into the main gas passage. A gas mixing system comprising: a gas passage; and a line perpendicular to both the axis and a longitudinal direction of the main gas passage at the position of the axis and one of two intersections with the inner wall. A first opening is provided at a position separated along the downstream side in the longitudinal direction, and the sub-gas passage communicates with the main gas passage through the first opening, and is provided in a circumferential direction of the main gas passage. The shape along the circle is a circle, the length of the first opening along the circumferential direction of the main gas passage is defined by a first arc, and the angle formed by two radii defining the first arc is: A gas mixture system having a temperature of 10 degrees or more and 60 degrees or less.