JP2012007563A - Gas injection structure to intake passage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To promote uniformization of gas concentration distribution after injection when EGR gas or the like, is smoothly injected into an intake passage, with respect to the gas injection structure to the intake passage.SOLUTION: The gas injection structure to the intake passage, is equipped with: a throttle valve 11 of butterfly type composed of a valve element 11, arranged in an intake passage 2 of an engine 1, and a stem part 12 supporting this valve element 11 possible to turn; a gas flow passage 13 formed inside the stem part 12; and an opening 15 for making the gas inside the gas flow passage 13 flow into a downstream side further than the valve element 11 of the intake passage 2. The opening 15 is formed in a wall part on the downstream further than the valve element 11 at an outer periphery of the gas flow passage 13 of the stem part 12 toward a direction deviated toward the side of the valve element 11 from the direction perpendicular to the valve element 11.

Description

  The present invention relates to a structure for introducing gas into an intake passage, which is suitable for use in exhaust gas recirculation for returning a part of exhaust gas to an intake passage in an engine (internal combustion engine) installed in an automobile or the like.

  In order to effectively suppress NOx in exhaust gas, an exhaust gas recirculation (EGR) device that returns a part of the exhaust gas to the intake passage side is used for an engine (internal combustion engine) installed in an automobile. ing. The recirculated exhaust gas (recirculated exhaust gas, EGR gas) is introduced downstream of the throttle valve in the intake passage, and is supplied to the combustion chamber of the engine while being mixed with fresh air introduced from the opening of the throttle valve.

  In such exhaust gas recirculation, the EGR gas is introduced into the intake passage as smoothly as possible, or the EGR gas concentration distribution is made uniform and supplied to the combustion chamber when the EGR gas is introduced into the intake passage. It is necessary to perform the desired combustion stably. In particular, since an ordinary engine has a plurality of cylinders, it is necessary to supply a uniform concentration of EGR gas to the combustion chamber of each cylinder in order to obtain smooth operation of the engine. Smooth introduction of EGR gas into the gas and uniformity of the EGR gas concentration distribution after the introduction are important.

In Patent Document 1, two introduction paths extending in the axial direction from both end portions of the shaft to the central portion are formed inside the valve shaft of the butterfly throttle valve, and EGR is introduced from each introduction passage entrance at both end portions of the shaft. A structure is described in which gas or PCV gas is introduced and introduced into the intake passage from the inlet passage outlet at the center of the shaft.
Japanese Patent Application Laid-Open No. H10-228667 includes a throttle valve composed of a disc-shaped valve body and a valve shaft that rotatably supports the valve body, and a purge passage for introducing evaporated fuel from a canister into an intake passage is provided as a throttle valve. A structure is described which is formed in the valve shaft and the valve body of the valve and opens the outlet of the purge passage on the side surface of the valve body on the downstream side of the intake flow.

  Not only EGR gas, but when introducing some gas into the intake passage and supplying it to the combustion chamber for combustion, as in the techniques of Patent Documents 1 and 2, the most upstream throttle valve in the intake passage where gas can be introduced If a gas passage is formed in the valve shaft of the valve and gas is introduced into the intake passage from the intake flow downstream side of the throttle valve, the distance until the gas supplied to the intake passage enters the combustion chamber can be maximized. This is effective for making the concentration distribution of the gas supplied to the combustion chamber uniform.

JP-A-61-36142 JP 2004-183592 A

By the way, when gas is introduced into the intake passage and supplied to the combustion chamber for combustion, the gas having a uniform concentration is supplied to the combustion chamber of each cylinder simply by increasing the distance until the gas enters the combustion chamber. Not enough to do. That is, how to smoothly introduce the gas into the intake passage and how to promote the homogenization of the concentration distribution of the gas after the introduction becomes a problem.
The present invention was devised in view of such a problem, and an intake passage that smoothly introduces EGR gas or the like into the intake passage and facilitates the uniform concentration distribution of the gas after the introduction. An object is to provide a gas introduction structure.

  In order to achieve the above object, a butterfly throttle valve, which is provided in an intake passage of an engine and includes a valve body and a shaft portion which rotatably supports the valve body, is formed inside the shaft portion. In the gas introduction structure to the intake passage, comprising the gas passage formed and an opening for introducing the gas in the gas passage to the downstream side of the throttle valve of the intake passage. It is characterized in that it is formed on the wall portion on the downstream side of the valve body on the outer periphery of the gas flow path of the shaft portion in a direction shifted from the direction orthogonal to the valve body to the valve body side. .

It is preferable that the opening is formed except for a region of the downstream wall portion in a direction orthogonal to the valve body.
It is preferable that the opening is formed in a direction shifted from a direction orthogonal to the valve body toward a side of the valve body that is downstream when the throttle valve is opened.
The shaft portion is disposed in a horizontal direction or a substantially horizontal direction. It is preferable that the opening is formed so as to be moved to the upstream side of the shaft portion, and the opening is formed in a direction shifted from the direction orthogonal to the valve body toward the upper side of the valve body.

It is preferable that the opening is partially formed in a central portion in the axial direction of a portion exposed in the intake passage of the shaft.
It is also preferable that the opening is divided into a plurality of parts in the axial direction of the shaft. In this case, it is preferable that a plurality are divided and formed including the central portion in the axial direction.
Or it is preferable that the said opening part is formed over the full length of the axial direction of the part exposed in the said intake passage of the said shaft part, or substantially full length.

It is also preferable that the opening is formed so that the inner diameter or the width thereof is increased as it goes downstream of the gas flow path of the shaft.
The gas is preferably EGR gas.

  According to the gas introduction structure to the intake passage of the present invention, in a butterfly throttle valve composed of a valve body and a shaft portion that rotatably supports the valve body, gas such as EGR gas is supplied to the shaft portion. The gas is made to flow through the gas flow path formed inside, and is introduced from the opening formed in the shaft portion to the downstream side of the throttle valve in the intake passage. As described above, when the gas is introduced from the shaft portion of the throttle valve into the intake passage, it is possible to secure a long distance until the gas enters the combustion chamber of the engine, and it is easy to promote uniform gas concentration distribution.

Of the fresh air that flows from the periphery of the throttle valve to the downstream side of the throttle valve when the throttle valve is opened, the fresh air from the end of the valve body that is upstream when the throttle valve is opened is a reverse vortex flow toward the shaft portion. Form. For this reason, when gas is introduced from the shaft portion to the throttle valve downstream side, the reversal vortex of the fresh air works to prevent the introduction of the gas, but the opening is formed in the wall portion on the downstream side of the valve body of the shaft portion. The gas introduced into the intake passage is not introduced so as to be opposed to the reverse vortex of the fresh air because it is formed in a direction deviating from the direction orthogonal to the valve body. . Therefore, it is possible to introduce gas to the downstream side of the throttle valve while reducing obstruction to gas introduction due to the fresh air reversal vortex, and the gas can be smoothly introduced.
If the opening is formed in a direction deviating from the direction perpendicular to the valve body to the downstream valve body when the throttle valve is opened, gas is supplied to the low flow velocity portion generated on the downstream side of the valve body. The gas can be introduced, the introduction and diffusion of the gas can be promoted, and the uniform concentration distribution of the gas can be easily promoted.

  When the shaft part is arranged in the horizontal direction and the throttle valve is opened, when the valve body upper part is rotated so as to move the valve body lower part to the downstream side than the shaft part and the valve body lower part to the upstream side than the shaft part, If the opening is formed in a direction shifted from the direction orthogonal to the valve body to the direction of the upper part of the valve body, the low flow velocity part generated on the downstream side of the lower part of the valve body can be used, and the gas to the intake passage can be used. Gravity can be used for introduction, and gas can be introduced into the intake passage more smoothly.

  When the inner diameter or width of the opening is enlarged as it goes downstream of the gas flow path of the shaft, the gas is uniformly supplied from the opening over the shaft, that is, in the axial direction of the shaft. This makes it easier to promote uniform gas concentration distribution.

Sectional drawing of the throttle valve part which shows the gas introduction structure to the intake passage concerning 1st Embodiment of this invention, (a) is a vertical sectional view, (b) is a horizontal sectional view (however, a throttle valve is fully open state). . 1 is a schematic view of an engine provided with an exhaust gas recirculation device according to a first embodiment of the present invention. It is sectional drawing explaining the characteristic of the flow of the fresh air in the intake passage concerning 1st Embodiment of this invention. It is a vertical sectional view of a throttle valve portion showing a gas introduction structure to an intake passage according to a second embodiment of the present invention. It is a vertical sectional view of a throttle valve portion showing a gas introduction structure to an intake passage according to a third embodiment of the present invention. FIG. 9 is a horizontal sectional view of a throttle valve portion showing a gas introduction structure to an intake passage according to a fourth embodiment of the present invention (however, the throttle valve is fully opened). FIG. 10 is a horizontal sectional view of a throttle valve portion showing a structure for introducing a gas into an intake passage according to a fifth embodiment of the present invention (however, the throttle valve is fully opened). It is a horizontal sectional view (however, throttle valve fully opened) of a throttle valve portion showing a gas introduction structure to an intake passage concerning a 6th embodiment of the present invention. It is a horizontal sectional view (however, a throttle valve is fully opened) showing a throttle valve portion showing a gas introduction structure to an intake passage according to a seventh embodiment of the present invention. It is a horizontal sectional view of a throttle valve portion showing a gas introduction structure to an intake passage according to an eighth embodiment of the present invention (however, the throttle valve is fully opened).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
First, a first embodiment of the present invention will be described with reference to FIGS.
(Engine supply / exhaust system configuration)
In this embodiment, the gas introduced downstream of the throttle valve in the intake passage is EGR gas, and the engine supply / exhaust system is configured as shown in FIG.

  That is, an engine body 1 having a plurality of cylinders includes an intake passage (including an intake manifold) 2 for supplying air into each cylinder, an exhaust passage (including an exhaust manifold) 3 for discharging exhaust gas from each cylinder, An EGR passage 4 for recirculating exhaust gas in the passage 3 to the intake passage 2, an EGR valve 5 for adjusting the amount of exhaust gas recirculated into the intake passage 2, and a throttle body 6 provided at the upstream end of the intake passage are connected. Has been. A surge tank (not shown) is provided in the upstream portion of the intake manifold downstream of the throttle body 6 so that the air-fuel mixture is homogenized and distributed to each cylinder.

  As shown in FIGS. 1A and 1B, the downstream end of the EGR passage 4 communicates with a gas flow path 13 formed in the axial center portion of the shaft portion 12 of the throttle valve 11 in the throttle body 6. It is connected to the. The throttle valve 11 is a butterfly type that includes a shaft portion 12 and a flat plate-like (usually disc-shaped) valve body 14 that is integrally coupled to the shaft portion 12. The body 14 rotates and opens and closes. The opening / closing drive is performed by an actuator (not shown).

Moreover, in Fig.1 (a), the throttle valve 11 is shown by the small opening state. On the other hand, in FIG. 1B, for convenience, the throttle valve 11 is shown in a fully open state, but the new air flow is shown with the throttle valve 11 in a small opening state.
The throttle valve 11 is provided at a location facing the horizontal direction of the intake passage 2 so that the shaft portion 12 faces in the horizontal direction. The valve body 14 has a valve body upper portion 14a more than the shaft portion 12 when fully closed. The valve body lower part 14b is slightly shifted to the downstream side and slightly inclined to the upstream side of the shaft part 12, and when opening the valve from this state, the valve body upper part 14a is moved downstream of the shaft part 12. It rotates so that it may move to the side and the valve body lower part 14b may be moved to the upstream rather than the axial part 12. FIG.

The gas flow path 13 formed in the axial center portion of the shaft portion 12 includes an opening 15 that faces the downstream portion of the valve body 14 of the throttle valve 11 in the intake passage 2. The EGR gas is introduced into the intake passage 2 downstream of the throttle valve. Of course, the introduction of the EGR gas is performed at a flow rate corresponding to the opening degree when the EGR valve 5 is opened.
The opening 15 is in a direction perpendicular to the surface of the valve body 14 of the throttle valve 11 on the wall portion downstream of the valve body 14 of the throttle valve 11 on the outer periphery of the gas flow path 13 of the shaft portion 12 (see the orthogonal line L1). It is formed toward the direction deviated from. Moreover, since the opening part 15 is arrange | positioned in the axial direction center part of the axial part 12, and is formed circularly by front view, EGR gas tends to flow out comparatively smoothly and its workability is also good. However, the shape of the opening 15 is not limited to a circle.

  The direction in which the opening 15 is formed will be described. FIG. 3 shows a simulation result of the flow of fresh air flowing into the downstream side of the valve body 14 of the throttle valve 11 when the throttle valve 11 is opened (small opening to medium opening) by using a vector. As shown by the arrow vector in FIG. 3, when the valve body 14 of the throttle valve 11 is opened, fresh air flows from the periphery of the valve body 14 of the throttle valve 11 to the downstream side of the valve body 14.

  As shown in FIG. 1 and FIG. 3, of the new airflow NF that flows in, from one end of the throttle valve that is upstream when the valve body 14 of the throttle valve 11 is opened (here, the end of the valve body lower portion 14 b). A part of the new air flow NF that enters forms a reversal vortex RV that flows backward toward the vicinity of the shaft portion 12, and the other end of the throttle valve (here, the downstream side when the valve body 14 of the throttle valve 11 is opened) Then, fresh air from the end of the valve body upper portion 14a does not form such an inverted vortex RV.

  This is because when the throttle valve is opened, fresh air flowing from one end of the throttle valve that opens on the upstream side (the end of the valve body lower portion 14b) flows into the other end of the throttle valve that opens on the downstream side (the valve body upper portion 14a). The inflow speed is stronger than the fresh air flowing in from the end), and a part of this strong flow goes to the other end of the relatively low-pressure throttle valve (the end of the valve body upper portion 14a). It is considered that the part forms an inverted vortex RV that flows backward toward the vicinity of the shaft part 12.

  In the vicinity of the shaft portion 12, such a fresh reversal vortex RV flows into the shaft portion 12 so as to hit the shaft portion 12 from substantially the front, and at the shaft portion 12, one end side of the throttle valve (the end portion side of the valve body lower portion 14 b). And the other end side (the end portion side of the valve body upper portion 14a), and thereafter flows along the surface of the valve body 14 in the direction of each end portion. For this reason, in the region A1 on the outer periphery of the shaft portion 12 shown in FIG. 3 (region in the direction orthogonal to the valve body 14 surface of the throttle valve 11) A1, the reversal vortex RV of fresh air hits from the front. If EGR gas is supplied from the inside of the flow path 13, the EGR gas cannot be supplied smoothly because it is hindered by the fresh air reversal vortex RV.

  On the other hand, as shown in FIG. 3, in the regions A2 and A3 deviated from the region A1 on the outer periphery of the shaft portion 12, the reversal vortex RV of the new air that has collided flows along the surface of the valve body 14 toward the end portions. Therefore, when EGR gas is supplied from the gas flow path 13 in these regions A2 and A3, the EGR gas flows along the flow of fresh air along the surface of the valve element 14 toward the end portions. It can be smoothly supplied without being disturbed by the reversal vortex RV of fresh air. In addition, area | region A1, A2, A3 can divide | segment and divide | segment the wall part area | region (approximately 180 degree | times) of the valve body 14 downstream of the axial part 12 into substantially equal parts.

  In the present embodiment, the opening 15 is formed in the region A2 located above the regions A2 and A3. As shown in FIGS. 1A and 3, the low flow velocity portion LF formed slightly above the vertical center of the intake passage 2 at a location separated from the valve body 14 on the downstream side of the valve body 14. This is intended to promote the introduction and diffusion of EGR gas by introducing EGR gas, and is particularly suitable when importance is attached to the diffusion of EGR gas. As shown in FIG. 1 (b), the low flow velocity portion LF is formed in the central portion in the horizontal direction (the axial direction of the shaft portion 12), and thus the opening portion disposed in the axial direction and the central portion. EGR gas supplied from 15 tends to flow in.

In the region A2, the flow speed of the fresh air is extremely low and the flow toward the end along the surface of the valve body 14 is weak, but at least there is little obstruction of the fresh air reversal vortex RV, and the EGR gas is reduced. It can be made to flow into the low flow velocity part LF, and the diffusion effect by the low flow velocity can be obtained while ensuring smooth introduction of EGR gas.
Since the gas introduction structure to the intake passage according to the present embodiment is configured as described above, the EGR gas is allowed to flow through the gas flow path 13 formed in the shaft portion 12 of the throttle valve 11 to be From the opening 15 formed in the portion 12, the intake passage 2 is introduced downstream of the throttle valve. When the EGR gas is introduced from the shaft portion 12 of the throttle valve 11 in this way, a long distance can be secured until the EGR gas enters the combustion chamber of each cylinder of the engine, and it is easy to promote uniformization of the EGR gas concentration distribution. Become.

  Further, when gas is introduced from the shaft portion 12 to the throttle valve downstream side, the fresh reversal vortex RV works to prevent the introduction of the EGR gas, but the opening 15 is formed on the wall portion on the downstream side of the throttle valve. Since it is formed in a direction deviating from the direction perpendicular to the surface of the throttle valve, the EGR gas introduced into the intake passage 2 is introduced from the front side against the reversal vortex RV of the fresh air. Not. Therefore, the EGR gas can be introduced to the downstream side of the throttle valve while reducing the disturbance to the gas introduction by the fresh air reversal vortex RV, and the EGR gas can be smoothly introduced.

Therefore, a gas having a uniform concentration can be supplied to the combustion chamber of each cylinder.
In particular, in this embodiment, the opening 15 is formed in the region A2 in a direction shifted from the direction orthogonal to the valve body 14 surface of the throttle valve 11 toward the valve body upper portion 14a. The EGR gas can be introduced into the low flow velocity portion LF formed at a location separated from the downstream valve body 14, the introduction and diffusion of the EGR gas can be promoted, and the concentration distribution of the EGR gas can be made uniform. Can be further promoted.

Further, when the opening 15 is disposed in the region A2, the opening 15 faces the downstream side of the new airflow even when the throttle valve 11 is fully opened, and the EGR gas can be smoothly introduced. When the throttle valve 11 is fully opened, the reverse vortex flow RV is not generated as shown in FIGS.
In the present embodiment, the opening 15 is not formed in the region A1 on the outer periphery of the shaft portion 12, but the gist of the present invention is that the opening 15 is orthogonal to the surface of the valve body 14 of the throttle valve 11. What is necessary is just to form so that gas may go to the direction which shifted | deviated from direction (the direction which shifted | deviated to the throttle valve upper part side in this embodiment). That is, even if a part of the opening 15 approaches the area A1, the center (flow center) of the opening 15 may be arranged in a direction shifted from the direction orthogonal to the valve body 14 surface of the throttle valve 11. .

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.
The gas introduction structure of this embodiment is different from the first embodiment only in the position of the opening 15, but the other configuration is the same as that of the first embodiment.
That is, in this embodiment, as shown in FIG. 3, the opening 15 is formed in a region A3 positioned below among the regions A2 and A3 shifted from the region A1 on the outer periphery of the shaft portion 12. As shown in FIG. 3, the flow of fresh air is strong along the surface of the valve body 14 toward the lower end, and if the opening 15 is formed below the valve body 14, Since the EGR gas can be put on the flow and the gravity action of the EGR gas, which is relatively heavy compared to fresh air, is added, the EGR gas can be introduced and the EGR gas can be introduced very smoothly.

  According to the gas introduction structure to the intake passage according to the present embodiment, the above configuration provides an effect that the EGR gas is introduced very smoothly. In addition, the EGR gas is supplied to the shaft portion 12 of the throttle valve 11. Since it is possible to ensure a long distance until the EGR gas enters the combustion chamber of each cylinder of the engine by introducing the EGR gas, it is easy to promote uniform concentration distribution of the EGR gas. A gas having a uniform concentration can be supplied.

  Also in the present embodiment, the opening 15 is not formed in the area A1 on the outer periphery of the shaft portion 12, but the gist of the present invention is that the opening 15 is connected to the surface of the valve body 14 of the throttle valve 11. What is necessary is just to form so that gas may go to the direction which shifted | deviated from the orthogonal direction (in this embodiment, the direction which shifted | deviated to the throttle valve upper part side). That is, even if a part of the opening 15 approaches the area A1, the center (flow center) of the opening 15 may be arranged in a direction shifted from the direction orthogonal to the valve body 14 surface of the throttle valve 11. .

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG.
In the gas introduction structure of this embodiment, the opening / closing direction of the throttle valve 11 which is a premise is different from those of the first and second embodiments.
That is, the throttle valve 11 of this embodiment is equipped with the shaft portion 12 in the horizontal direction at a location facing the horizontal direction of the intake passage 2 as in the first and second embodiments. When fully closed, the valve body upper portion 14a is slightly shifted upstream from the shaft portion 12 and the valve body lower portion 14b is shifted slightly downstream from the shaft portion 12 so that the valve is opened from this state. In this case, the valve body upper part 14a is moved to the upstream side of the shaft part 12, and the valve body lower part 14b is rotated to move to the downstream side of the shaft part 12.

  In this case, the flow of fresh air when the throttle valve 11 is opened is the flow vector shown in FIG. 3 upside down, and a reverse air vortex RV as shown by an arrow in FIG. 5 is formed. Similarly to the first and second embodiments, the low flow velocity portion LF is formed in the intake passage 2, contrary to the low flow velocity portion LF formed at a location separated from the valve body 14 on the downstream side of the valve body 14. It is formed slightly below the vertical center.

  Similar to the first and second embodiments, in the vicinity of the shaft portion 12, such a fresh reversal vortex RV flows into the shaft portion 12 so as to hit the shaft portion 12 from the front, and the shaft portion 12 has one end of the throttle valve. Branching into a part side (end part side of the valve body lower part 14b) and the other end part side (end part side of the valve body upper part 14a), and thereafter flowing in the direction of each end part along the surface of the valve body 14 Yes. For this reason, as in the case shown in FIG. 3, in the region A1 on the outer periphery of the shaft portion 12 (region in the direction orthogonal to the valve body 14 surface of the throttle valve 11) A1, the fresh air reversal vortex RV collides from the front. If EGR gas is supplied from the gas flow path 13 in this region A1, it cannot be smoothly supplied because it is hindered by the reversal vortex RV of fresh air.

  That is, in this embodiment, as shown in FIG. 5, the opening 15 is formed in a region A3 positioned below among the regions A2 and A3 that are shifted from the region A1 on the outer periphery of the shaft portion 12. As shown in FIG. 5, the flow of fresh air toward the lower end portion along the surface of the valve body 14 is not strong. However, if the opening 15 is formed below the valve body 14, the fresh air flows. Since the gravity action of EGR gas which is relatively heavy as compared with the above is also added, the introduction of EGR gas is enhanced and the EGR gas is introduced very smoothly.

  According to the gas introduction structure to the intake passage according to the present embodiment, the above configuration provides an effect that the EGR gas is introduced very smoothly. In addition, the EGR gas is supplied to the shaft portion 12 of the throttle valve 11. Since it is possible to ensure a long distance until the EGR gas enters the combustion chamber of each cylinder of the engine by introducing the EGR gas, it is easy to promote uniform concentration distribution of the EGR gas. A gas having a uniform concentration can be supplied.

Further, when the opening 15 is formed below the shaft portion 12, the EGR gas flows into the low flow velocity portion LF formed slightly below the vertical center of the intake passage 2, so that the EGR gas is smoothly flown at the low flow velocity portion LF. A diffusion effect due to a low flow rate can be obtained while ensuring a good introduction property.
Also in this embodiment, the opening 15 is not formed in the region A1 on the outer periphery of the shaft portion 12, but the gist of the present invention is that the opening 15 is orthogonal to the surface of the valve body 14 of the throttle valve 11. What is necessary is just to form so that gas may go to the direction which shifted | deviated from direction (the direction which shifted | deviated to the throttle valve upper part side in this embodiment). That is, even if a part of the opening 15 approaches the area A1, the center (flow center) of the opening 15 may be arranged in a direction shifted from the direction orthogonal to the valve body 14 surface of the throttle valve 11. .

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIG.
In the gas introduction structure of this embodiment, a plurality of openings 15a to 15c are provided. In this example, one opening 15b is arranged in the central portion of the shaft 12 in the axial direction, and one opening 15a, 15c is symmetrically arranged on each side, and a total of three openings are provided. The number of 15c is not limited to this. For example, two may be arranged symmetrically around the axial center of the shaft 12 or four or more may be provided. In addition, here, any of the openings 15a to 15c is formed in a circle when viewed from the front with the same diameter, but in this case as well, the shapes of the openings 15a to 15c are not limited to a circle.

The positions of the openings 15a to 15c in the circumferential direction of the shaft portion 12 may be the same as in the first embodiment or the same as in the second embodiment. Further, when the opening direction of the throttle valve 11 is different from that of the first embodiment, it is the same as that of the third embodiment.
According to the gas introduction structure to the intake passage according to the present embodiment, in addition to the effects of the above-described embodiments, the total area of the openings 15a to 15c can be largely ensured by the above configuration. It is possible to secure the EGR gas supply amount when the gas supply amount is increased or when the EGR gas supply pressure is low pressure EGR.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described with reference to FIG.
In the gas introduction structure of the present embodiment, one long hole is provided as the opening 15d. In this example, it is formed in a rectangle when viewed from the front, but the shape of the elongated hole is not limited to a rectangle, and may be an ellipse or an ellipse.
The position of the opening 15d in the circumferential direction of the shaft portion 12 may be the same as in the first embodiment or the same as in the second embodiment. Further, when the opening direction of the throttle valve 11 is different from that of the first embodiment, it is the same as that of the third embodiment.

  According to the gas introduction structure to the intake passage according to the present embodiment, the above configuration reduces the area of the opening 15d in addition to the effects of the first to third embodiments, similarly to the fourth embodiment. Since a large amount can be secured, it is possible to increase the EGR gas supply amount, or to secure the EGR gas supply amount in the case of a low pressure EGR with a low EGR gas supply pressure.

[Sixth Embodiment]
Next, a sixth embodiment of the present invention will be described with reference to FIG.
In the present embodiment, a plurality of openings 15e to 15g are provided as in the fourth embodiment, but the openings 15e to 15g are formed larger toward the downstream of the gas flow path 13 (upward in FIG. 8). The other points are the same as in the fourth embodiment.
According to the gas introduction structure to the intake passage according to the present embodiment, in addition to the effects of the fourth embodiment, the gas from the pressure loss as it goes downstream (upward in FIG. 8) of the gas flow path 13 by the above configuration. Therefore, the EGR gas can be supplied evenly in a well-balanced manner in the axial direction of the shaft portion 12.

[Seventh Embodiment]
Next, a seventh embodiment of the present invention will be described with reference to FIG.
In the present embodiment, as in the fifth embodiment, one elongated hole is provided as the opening 15h. However, the width of the elongated hole-shaped opening 15h (the length in the circumferential direction of the shaft portion 12) is large. The difference is that it is formed larger as it goes downstream (upward in FIG. 8) of the gas flow path 13, and the other configuration is the same as in the fifth embodiment. Moreover, in this example, it is formed in a substantially triangular shape when viewed from the front, but the shape of the elongated slot is not limited to this.

According to the gas introduction structure to the intake passage according to the present embodiment, in addition to the same effects as those of the fifth embodiment, the pressure loss increases toward the downstream of the gas flow path 13 (upward in FIG. 8). Therefore, the problem that the gas supply amount decreases can be suppressed, and the EGR gas can be supplied in a balanced manner in the axial direction of the shaft portion 12.
[Eighth Embodiment]
Next, an eighth embodiment of the present invention will be described with reference to FIG.

In the present embodiment, a structure for cooling the throttle valve 11 is added. In this example, the throttle valve 11 is cooled by introducing a refrigerant (cooling water) into the refrigerant circulation space 6 a formed in the throttle body 6 and cooling the cooling fins 16 connected to the shaft portion 12. I have to.
In this example, the cooling structure is added to the first embodiment, but it may be applied to any of the second to seventh embodiments.

  According to the gas introduction structure to the intake passage according to the present embodiment, in addition to the effects of the above-described embodiments, the throttle valve 11, particularly the shaft portion 12, can be cooled by the above-described configuration. The EGR gas supply efficiency can be increased by reducing the temperature of the EGR gas, and the thermal expansion of the throttle valve 11 due to the heat of the high temperature EGR gas can be suppressed. Can be secured.

[Others]
Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications or appropriate combinations may be made without departing from the spirit of the present invention. Can do.

  For example, in the above-described embodiment, an example in which the present structure is applied to introduce EGR gas into the intake passage has been described. However, not only EGR gas but also evaporated fuel gas from a canister, PCV (positive crankcase bench) The present invention is applicable to the introduction of various gases supplied together with fresh air into the combustion chamber of the engine, such as gas.

  The present invention is suitable for use in an EGR device that recirculates exhaust gas to an engine. However, not only EGR gas but also evaporated fuel gas from a canister, PCV (positive crankcase ventilation) gas, etc. The present invention can be widely applied to introduction of gas supplied together with fresh air into the combustion chamber into the intake passage.

DESCRIPTION OF SYMBOLS 1 Engine main body 2 Intake passage 3 Exhaust passage 4 EGR passage 5 EGR valve 6 Throttle body 11 Throttle valve 12 Shaft part 13 Gas flow path 14 Valve body 14a Valve body upper part 14b Valve body lower part 15, 15a-15h Opening part 16 Fin A1 Throttle Regions in the direction orthogonal to the valve body 14 surface of the valve 11 A2, A3 Regions deviated from the direction orthogonal to the valve body 14 surface of the throttle valve 11 NF New airflow LF Low flow velocity portion RV Inverted vortex

Claims (9)

A butterfly throttle valve that is provided in an intake passage of an engine and includes a valve body and a shaft portion that rotatably supports the valve body; a gas flow path formed in the shaft portion; and the gas In the gas introduction structure to the intake passage, comprising an opening for introducing the gas in the flow path to the downstream side of the throttle valve of the intake passage,
The opening is formed in a wall portion on the downstream side of the valve body on the outer periphery of the gas flow path of the shaft portion in a direction shifted from the direction orthogonal to the valve body to the valve body side. A gas introduction structure to the intake passage. 2. The gas introduction structure to the intake passage according to claim 1, wherein the opening is formed by excluding a region of the downstream wall portion in a direction orthogonal to the valve body. 3. The opening is formed in a direction shifted from a direction orthogonal to the valve body toward a side of the valve body that is downstream when the throttle valve is opened. Or the gas introduction structure to the intake passage of 2. The shaft portion is disposed in a horizontal direction or a substantially horizontal direction, and the valve body is disposed in a substantially vertical direction when the valve is closed, and when the valve is opened, the valve body upper portion is disposed downstream of the shaft portion and the valve body lower portion is disposed on the downstream side. Rotate to move upstream from the shaft,
The said opening part is formed toward the direction shifted | deviated from the direction orthogonal to the said valve body to the said valve body upper part side, The any one of Claims 1-3 characterized by the above-mentioned. Gas introduction structure to the intake passage. 5. The intake air according to claim 1, wherein the opening is partially formed at a central portion in an axial direction of a portion exposed in the intake passage of the shaft portion. Gas introduction structure to the passage. The gas introduction structure to the intake passage according to any one of claims 1 to 5, wherein the opening is divided into a plurality of parts in the axial direction of the shaft. 6. The intake air according to claim 1, wherein the opening is formed over the entire axial length or substantially the entire length of a portion exposed in the intake passage of the shaft portion. Gas introduction structure to the passage. 8. The gas introduction into the intake passage according to claim 6, wherein the opening is formed so that an inner diameter or a width thereof is enlarged toward a downstream side of the gas flow path of the shaft portion. Construction. The gas introduction structure to the intake passage according to claim 1, wherein the gas is EGR gas.

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