JP5389003B2 - Intake device for internal combustion engine - Google Patents

Description

  The present invention relates to an intake device for an internal combustion engine.

  Conventionally, in order to improve the responsiveness of an engine, it is known that it is effective to shorten the length of an intake passage between a throttle valve and a combustion chamber, for example. As an intake device for an engine in which a throttle valve is brought close to a combustion chamber, for example, in the structure disclosed in Patent Document 1, a device having a throttle valve and an injector is attached to an intake port of a cylinder head via an annular joint. Structure. And what is disclosed by patent document 1 is a structure which arrange | positions an injector to the downstream end part of a throttle body.

JP 2003-239801 A

As disclosed in Patent Document 1, in the case where the injector is arranged close to the intake port, the spray flow of the injector is greatly influenced by the intake flow flowing from the throttle body.
That is, the mist-like fuel sprayed from the spray port of the injector is subjected to a large pressure from the lateral direction of the spray direction by the intake flow flowing through the gap between the inner wall surface of the throttle body and the tip edge of the throttle valve, and becomes a spray flow. Bias occurs. When fuel adheres to the inner wall surface of the intake port due to the influence of the deviation of the spray flow, mixed air with a non-uniform concentration distribution may be supplied into the cylinder. It has been a problem in terms of reduction in emissions and exhaust emissions.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to prevent fuel from adhering to the inner wall surface of the intake port and supply mixed air having a uniform concentration distribution into the cylinder. An object of the present invention is to provide an intake device for an internal combustion engine.

In order to achieve the above object, the invention according to claim 1 is provided with a throttle valve provided in a freely swingable manner with a rotating shaft in a throttle body disposed adjacent to the intake port, In an intake device for an internal combustion engine comprising an injector that sprays fuel toward the intake port and downstream of the throttle valve,
The intake port is provided on one side of the cylinder head of the internal combustion engine and has a substantially cylindrical shape that is substantially straight from the obliquely upper side of the cylinder head toward the back surface of the intake valve of the internal combustion engine disposed downstream thereof. Forming an intake passage,
The throttle body is disposed on the upstream side of the intake port and forms a substantially linear intake passage having a substantially cylindrical shape,
The rotating shaft is arranged in a direction orthogonal to the axis of the intake passage of the throttle body in a plan view and orthogonal to the axis of the intake valve in a plan view,
The throttle valve is attached to the rotary shaft, and the side close to the injector rotates toward the downstream side of the intake port across the rotary shaft, and the side far from the injector faces the upstream side of the intake port Rotate,
The injector is arranged such that its spray port is opened below the throttle body and below the throttle valve axis so that fuel is sprayed toward the downstream side of the intake port,
In the fully closed state of the throttle valve, the side where the spray port of the injector is not disposed with respect to the opening and closing wall surface portion of the throttle valve on the side where the spray port of the injector is disposed across the rotating shaft. The leading edge of the throttle valve is disposed upstream of the intake port;
The size of the gap between the inner wall surface of the throttle body and the leading edge of the throttle valve, in a cross section perpendicular in the longitudinal center to the rotating shaft, so side becomes smaller spray nozzle of the injector is arranged It is structured.

According to a second aspect of the present invention, in addition to the configuration of the first aspect, the throttle valve has a fully-closed set angle on the side where the spray port is disposed and the other side when viewed from the axial direction of the rotating shaft. It is characterized in that the fully closed set angle is different.

According to a third aspect of the present invention, in addition to the configuration of the first or second aspect , the throttle valve has two planes, a first opening / closing wall and a second opening / closing wall, as viewed from the axial direction of the rotating shaft. And both the opening and closing walls are configured to have a predetermined angle.

According to a fourth aspect of the present invention, in addition to the configuration according to any one of the first to third aspects , the throttle valve includes the first opening / closing wall and the second opening / closing wall sandwiching the rotation shaft. It is formed on the opposite side.

The invention according to claim 5, in addition to the arrangement of claim 1, wherein the throttle valve is a straight planar structure as seen from the direction of the rotary shaft, the first contrast sides across the rotation axis The opening / closing wall and the second opening / closing wall on the other side are configured to have different lengths.

The invention according to claim 6 includes a throttle valve provided in a freely swingable manner with a rotation shaft in a throttle body disposed adjacent to the intake port, and is directed from the throttle body toward the intake port and the In an intake device for an internal combustion engine including an injector that sprays fuel downstream of the throttle valve,
The rotation shaft is arranged to be biased toward the injector with respect to the central axis of the throttle body,
The size of the gap between the inner wall surface of the throttle body and the tip edge of the throttle valve is configured such that the side on which the spray port of the injector is disposed becomes smaller in the cross section orthogonal to the rotation shaft at the center in the longitudinal direction. It is characterized by that.

According to the first aspect of the present invention, the size of the gap between the inner wall surface of the throttle body and the tip edge of the throttle valve is configured such that the side on which the spray port of the injector is disposed becomes smaller, so that the spray port Since the intake air flow rate on the closer side can be reduced, the air pressure with respect to the spray flow immediately after spraying can be reduced to prevent unintentional bias of the spray flow. Therefore, adverse effects on the spray flow caused by the intake air flow can be avoided, fuel can be prevented from adhering to the inner wall surface of the intake port, and mixed air having a uniform concentration distribution can be supplied into the cylinder.
According to the first aspect of the present invention, when the injector is disposed on the lower side of the throttle body, in particular, the spray flow is affected by the intake air flowing on the injector side of the intake port, and thus the lower part of the intake port. Although it tends to adhere to the side wall surface, it is configured so that the flow rate of the intake air on the lower side where the spray port of the injector is arranged can be reduced, so that the downward bias of the spray flow can be effectively avoided, and the spray fuel Is prevented from adhering to the inner wall surface below the intake port, so that mixed air having a uniform concentration distribution can be supplied into the cylinder.

According to the invention of claim 2 , when the throttle valve is configured such that the fully closed set angle on one side of the rotation shaft is different from the fully closed set angle on the other side, the throttle valve rotates. The size of the opening area on one side and the other side can be made different. Accordingly, it is possible to reduce the intake air flow rate on the side close to the spray port, avoiding the bias of the spray flow from the injector, and supplying mixed air having a uniform concentration distribution into the cylinder.

According to the invention of claim 3 , the throttle valve is configured such that the first opening / closing wall and the second opening / closing wall have a predetermined angle when viewed from the direction of the rotation shaft, thereby sandwiching the rotation shaft. Since the fully closed set angles on both sides can be made different, the size of the opening area on the first opening / closing wall side and the second opening / closing wall side can be changed across the rotation axis. Therefore, the flow rate of the intake air on the side close to the spray port can be reduced, and the spray flow from the injector can be effectively spread without any deviation to supply mixed air with a uniform concentration distribution into the cylinder. it can.

According to the invention of claim 4, the throttle valve, by a first closing wall and the second closing wall is formed on the opposite sides of the rotational axis, in addition to the effect of claim 4, the first Since the bending points of the opening / closing wall and the second opening / closing wall coincide with the rotation axis, the shape of the throttle valve can be easily set and manufactured. Therefore, the adverse effect of the spray flow due to the intake air flow can be avoided and the manufacturability can be improved.

According to the invention of claim 5 , the throttle valve has a straight planar structure when viewed from the direction of the rotation axis, and the valve itself is constituted by one flat surface. Since the first opening / closing wall on one side and the second opening / closing wall on the other side have different lengths across the shaft, for example, one end side having a long turning radius and the other having a short turning radius across the rotation shaft The size of the opening area can be easily changed between the end sides. Therefore, it is possible to change the intake air flow rate between the side closer to the spraying port and the side farther from the spraying port, and it is possible to avoid a situation in which the fuel flow distribution becomes uneven by eliminating the bias of the spraying flow from the injector. Further, the throttle valve can easily set the size of the opening area on the first opening / closing wall side and the second opening / closing wall side by setting the position of the rotary shaft.

According to the invention of claim 6, the size of the gap between the inner wall surface of the throttle body and the tip edge of the throttle valve is configured such that the side on which the spray port of the injector is disposed becomes small, so that the spray port Since the intake air flow rate on the closer side can be reduced, the air pressure with respect to the spray flow immediately after spraying can be reduced to prevent unintentional bias of the spray flow. Therefore, adverse effects on the spray flow caused by the intake air flow can be avoided, fuel can be prevented from adhering to the inner wall surface of the intake port, and mixed air having a uniform concentration distribution can be supplied into the cylinder.
Further, according to the invention of claim 6, the axis of rotation, that are arranged offset to the injector side with respect to the central axis of the throttle body, across the rotary shaft and the one end and the other end The radius of rotation can be changed, and the intake air flow rate can be reduced by reducing the gap on the side close to the spray port when the valve is opened. Therefore, since the pressure on the spray flow near the spray port can be reduced, it is possible to avoid the adverse effect on the spray flow and supply mixed air having a uniform concentration distribution into the cylinder. Further, since the throttle valve has a flat one-surface structure, its manufacturability is very good, and the opening area on the upper and lower ends of the rotating shaft can be easily set by setting the position of the rotating shaft.

It is principal part sectional drawing of 1st Embodiment of the intake device of the internal combustion engine which concerns on this invention. FIG. 2 is an enlarged sectional view showing a closed state of a throttle valve in the intake device shown in FIG. 1. FIG. 3 is an enlarged perspective view of a throttle valve in the intake device shown in FIG. 2. FIG. 2 is an enlarged cross-sectional view showing an open state of a throttle valve in the intake device shown in FIG. 1. It is principal part sectional drawing of 2nd Embodiment of the intake device of the internal combustion engine which concerns on this invention. FIG. 6 is an enlarged perspective view of a throttle valve in the intake device shown in FIG. 5. It is principal part sectional drawing of 3rd Embodiment of the intake device of the internal combustion engine which concerns on this invention. FIG. 8 is an enlarged perspective view of a throttle valve in the intake device shown in FIG. 7. It is principal part sectional drawing of 4th Embodiment of the intake device of the internal combustion engine which concerns on this invention. FIG. 10 is an enlarged perspective view of a throttle valve in the intake device shown in FIG. 9. FIG. 10 is an enlarged cross-sectional view showing an open state of a throttle valve in the intake device shown in FIG. 9 .

(First embodiment)
The first embodiment of the present invention will be described below.
The first embodiment will be described in detail with reference to FIGS.
As shown in FIG. 1, the present embodiment is applied to a V-type internal combustion engine 1 mounted on a motorcycle, for example.
The internal combustion engine 1 includes a cylinder head 3 above a cylinder 2 including a piston 2P. The cylinder head 3 receives an intake valve 8a that controls intake air from an intake port 5 and exhaust gas from an exhaust port 6. An exhaust valve 8b to be controlled is provided.
The intake valve 8a and the exhaust valve 8b are appropriately operated by the rotation of cams 7a and 7b provided on a pair of cam shafts 6a and 6b disposed on the upper end side of the valve. The upper sides of the camshafts 6a and 6b and the cams 7a and 7b are appropriately covered with a head cover 4.

In the intake device 10 in the present embodiment, a throttle body 12 is disposed adjacent to the intake port 5. The throttle body 12 is provided with an injector 11 and a throttle valve 20 that has a rotating shaft 21 and is swingably provided. The throttle body 12 is appropriately connected with a cleaner box having an air cleaner or the like (not shown) on the upstream side of the intake air flow.
The injector 11 is disposed on the most downstream side of the intake air flow in the throttle body 12 and sprays fuel toward the intake port 5. That is, the injector 11 is configured such that the spray port 11a is positioned downstream of the throttle valve 20, and is inclined at an appropriate angle with respect to the center line CL of the throttle body 12 toward the downstream side of the intake port. Is configured to spray. The injector 11 is disposed below the throttle body 12.

  In the present embodiment, as shown in FIG. 3, the throttle valve 20 has a substantially disk-like structure, but the upper semicircle with respect to the first opening / closing wall 22 which is the lower semicircle portion on the lower side of the rotating shaft 21. The portion of the second opening / closing wall 23 is inclined at a predetermined angle α (an angle greater than 90 ° and less than 180 °). As shown in FIG. 2, the throttle valve 20 has a first opening / closing wall on the lower side of the rotary shaft 21 as viewed from the axial direction of the rotary shaft 21 (in a cross section orthogonal to the longitudinal center of the rotary shaft). 22 and the inner wall surface 12a make the fully closed set angle θ1 (the angle when the throttle is most throttled) is 90 °, whereas the upper second opening / closing wall 23 and the inner wall surface 12a make all The closed set angle θ2 is configured to be smaller than 90 °.

  That is, the first opening / closing wall 22 has a semicircular shape with a predetermined radius L 1, whereas the second opening / closing wall 23 has a radius of the first opening / closing wall 22 in a cross section orthogonal to the longitudinal center of the rotating shaft 21. It is configured in an elliptical shape having a major axis radius L2 longer than L1. The major axis radius L2 increases as the crossing angle α between the second opening / closing wall 23 and the first opening / closing wall 22 decreases, and therefore the size of the major axis radius L2 increases. Thus, when the major axis radius L2 increases, for example, when the rotary shaft 21 rotates, the moving distance of the tip edge 20a increases. This means that the second opening / closing wall 23 moves more than the first opening / closing wall 22 as the rotation shaft 21 rotates.

The effect | action in this embodiment is demonstrated with reference to FIG.
When the throttle valve 20 is configured as described above, when the valve is fully closed (the state shown in FIG. 2), the entire leading edge 20a of the throttle valve 20 is closest to the inner wall surface 12a of the throttle body 12. It is. In this state, the intake flow flowing through the throttle body is extremely small.
However, the intake flow rate is increased by rotating the throttle valve 20 (rotation in the direction of arrow R) to increase the engine speed. That is, the rotation of the throttle valve 20 increases the gap between the inner wall surface 12a of the throttle body 12 and the tip edge 20a of the throttle valve 20 as shown in FIG. 4, and the intake air flow rate gradually increases.

When the throttle valve 20 rotates, the distance d1 between the tip edge 20a of the first opening / closing wall 22 and the inner wall surface 12a becomes smaller than the distance d2 between the tip edge 20a of the second opening / closing wall 23 and the inner wall surface 12a. As a result, the lower valve opening area in FIG. 4 is smaller than the upper valve opening area.
Thus, since the valve opening area on the side where the spray port 11a of the injector 11 is arranged is small, the intake air flow rate on the side close to the spray port 11a becomes smaller than the opposite side (upper side in the figure). Therefore, the air pressure (Ar) on the side closer to the spray port 11a can be kept small with respect to the spray flow 11f from the spray port 11a.

  Therefore, the spray flow 11f from the injector 11 is sprayed with a desired spread without being biased without being largely pushed downstream in the vicinity of the spray port 11a. As a result, adverse effects on the spray flow 11f due to the intake air flow are avoided, and mixed air with a uniform concentration distribution is supplied into the cylinder without unevenness of fuel adhering to the lower inner wall surface of the intake port 5. Can do.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described.
This embodiment will be described in detail with reference to FIGS. In addition, the same code | symbol is attached | subjected to the same component as 1st Embodiment in a figure, and the description is abbreviate | omitted suitably.

In the present embodiment, the throttle valve 30 has a substantially disk-like structure, but as shown in FIG. 6, the upper half circle with respect to the first opening / closing wall 32 which is the lower half circle portion on the lower side of the rotation shaft 31. The second opening / closing wall 33, which is a part, has a second opening / closing wall base 33a and a second opening / closing wall tip 33b with a bent portion 34 as a boundary at a substantially middle portion thereof.
The second opening / closing wall 33 has a second opening / closing wall base 33a on the same plane as the first opening / closing wall 32, and the second opening / closing wall has an intersecting angle α with respect to the second opening / closing wall base 33a. A tip 33b is provided.

Accordingly, as shown in FIG. 5, the throttle valve 30 of the present embodiment has a fully closed set angle θ1 of 90 ° at the first opening / closing wall 32 below the rotary shaft 31 when viewed from the axial direction of the rotary shaft 31. On the other hand, the fully closed set angle θ2 of the second opening / closing wall tip 33b on the upper side is made smaller than 90 °.
Even in this configuration, the second opening / closing wall 33 has a maximum turning radius L2 that is larger than the maximum turning radius L1 of the first opening / closing wall 32.

The operation in this embodiment will be described.
When the throttle valve 30 is in the fully closed state as shown in FIG. 5, the entire leading edge 30a of the throttle valve 30 is closest to the inner wall surface 12a of the throttle body 12, but the throttle valve 30 rotates ( (Rotation in the direction of arrow R), the gap between the inner wall surface 12a of the throttle body 12 and the tip edge 30a of the throttle valve 30 increases with the rotation, as in the first embodiment.

When the throttle valve 30 is rotating, the distance between the leading edge 30a of the first opening / closing wall 32 and the inner wall surface 12a is larger than the distance between the leading edge 30a of the second opening / closing wall 33 and the inner wall surface 12a. Becomes smaller.
Therefore, as in the first embodiment, the valve opening area on the side where the spray port 11a of the injector 11 is disposed is smaller than the opposite side, so that the intake air flow rate on the side closer to the spray port 11a is smaller than the opposite side. The air pressure (Ar) for the spray flow 11f from the injector 11 can be kept small.
As a result, as in the first embodiment, by controlling the pressure applied to the spray flow 11f by the intake air flow, there is no bias such as fuel adhering to the lower inner wall surface of the intake port 5, and the concentration distribution is uniform. Fresh mixed air can be supplied into the cylinder.

(Third embodiment)
Hereinafter, a third embodiment of the present invention will be described.
This embodiment will be described in detail with reference to FIGS. In addition, the same code | symbol is attached | subjected to the same component as the said embodiment, and the description is abbreviate | omitted.

Also in the present embodiment, the throttle valve 40 has a substantially disk-like structure, but as shown in FIGS. 7 and 8, the first opening / closing wall 42 on the lower side of the rotation shaft 41 is configured by a flat plane. On the other hand, the second open / close wall 43 in the upper semicircular portion has a curved structure in which the surface on the upstream side of the intake air flow is recessed when viewed from the rotation axis direction (direction shown in FIG. 7).
Therefore, as shown in FIG. 7, the throttle valve 40 of the present embodiment has a fully closed set angle θ1 of 90 ° at the first opening / closing wall 42 below the rotary shaft 41 when viewed from the axial direction of the rotary shaft 41. On the other hand, the substantially fully closed set angle θ2 of the upper second opening / closing wall 43 is smaller than 90 °. That is, the second opening / closing wall 43 has a maximum rotation radius L2 that is larger than the maximum rotation radius L1 of the first opening / closing wall 42.

The operation in this embodiment will be described.
In the state shown in FIG. 7, the throttle valve 40 according to the present embodiment is in a state in which the entire leading edge 40a of the throttle valve 40 is closest to the inner wall surface 12a of the throttle body 12 in the fully closed state. By rotating 40 (rotation in the direction of arrow R), the gap between the inner wall surface 12a of the throttle body 12 and the tip edge 40a of the throttle valve 40 is increased as in the above-described embodiments.

When the throttle valve 40 rotates, the distance between the leading edge 40a of the first opening / closing wall 42 and the inner wall surface 12a is smaller than the distance between the leading edge 40a of the second opening / closing wall 43 and the inner wall surface 12a. . Therefore, as in the above-described embodiments, when the valve opening area on the side where the spray port 11a of the injector 11 is disposed is small, the intake air flow rate on the side closer to the spray port 11a is made smaller than on the opposite side. The air pressure (Ar) for the spray flow 11f from the injector 11 can be kept small.
Therefore, in this embodiment as well, as in the previous embodiments, the pressure applied to the spray flow 11f by the intake air flow is controlled to eliminate bias such as the adhesion of fuel to the lower inner wall surface of the intake port 5. The mixed air having a uniform concentration distribution can be supplied into the cylinder.

(Fourth embodiment)
The fourth embodiment of the present invention will be described below.
The present embodiment will be described in detail with reference to FIGS. In addition, the same code | symbol is attached | subjected to the same component as the said embodiment, and the description is abbreviate | omitted.

  Also in this embodiment, the throttle valve 50 has a disk-like structure, but as shown in FIGS. 9 and 10, the position of the rotary shaft 51 is shifted downward. In the present embodiment, the throttle valve 50 has a lower first opening / closing wall 52 and an upper second opening / closing wall 53 configured as a single plane, and the rotary shaft 51 is mounted at a position shifted downward from the center line CL. It has been.

Therefore, as shown in FIG. 9, the throttle valve 40 of the present embodiment has a fully closed set angle θ1 of the first opening / closing wall 52 on the lower side of the rotary shaft 51, as viewed from the axial direction of the rotary shaft 51, and The fully closed set angle θ2 of the second opening / closing wall 53 on the side is 90 °.
However, the second opening / closing wall 53 has a length greater than the length L1 of the first opening / closing wall 52 in the direction perpendicular to the rotation shaft 51 at the center in the longitudinal direction by the amount that the rotation shaft 51 is displaced downward. L2.
Note that the contour shape of the second opening / closing wall 53 is appropriately formed in a substantially oval shape so that the throttle valve 40 can rotate to a substantially fully opened state (a state substantially parallel to the center line CL).

The operation in this embodiment will be described.
In the state shown in FIG. 9, the throttle valve 50 in the present embodiment is in a state in which the entire front end edge 50 a of the throttle valve 50 is closest to the inner wall surface 12 a of the throttle body 12 in the valve fully closed state.
However, as shown in FIG. 11, when the throttle valve 50 rotates in a predetermined direction (rotation in the direction of arrow R), the inner wall surface 12a of the throttle body 12 and the leading edge 50a of the throttle valve 50 are the same as in the above-described embodiments. The gaps d1 and d2 are increased.
When the throttle valve 50 rotates, the distance d1 between the leading edge 50a of the first opening / closing wall 52 and the inner wall surface 12a is larger than the distance d2 between the leading edge 50a of the second opening / closing wall 53 and the inner wall surface 12a. small. As a result, as in the previous embodiments, the valve opening area on the side of the injector 11 where the spray port 11a is disposed is smaller than the opposite side, and the intake air flow rate on the side closer to the spray port 11a is reduced to the opposite side. As a result, the air pressure (Ar) with respect to the spray flow 11f from the injector 11 can be kept small.

  Therefore, the gap d1 on the side close to the spraying port 11a can be reduced, the intake air flow rate on the side is reduced, the air pressure to the spraying flow 11f is weakened, and the mixed air having a uniform concentration distribution is obtained by making the spray uniform. Can be supplied within. In addition, since the throttle valve 50 in the present embodiment is configured with a flat surface, its manufacturability is very good, and further, the opening area difference between the upper and lower ends of the rotating shaft 51 is set by the position setting of the rotating shaft 51. Can be easily done.

The first to fourth embodiments to which the present invention is applied have been described above, but the present invention is not limited to this. For example, the bent structure, curved structure, and rotating shaft of the opening / closing wall of the throttle valve are shifted from the center line. In addition, a structure in which a structure in which the turning radius of the opening / closing wall is reduced, or the like is appropriately combined may be used.
Moreover, although embodiment mentioned above showed the example which applied this invention to the motorcycle, this invention is not restricted to this, You may apply to another vehicle.

1 internal combustion engine 2 cylinder 3 cylinder head 5 intake port 6 exhaust port 10 intake device 11 injector 11a spray nozzle 12 throttle body 20,30,40,5 0 throttle valve 20a, 30a, 40a, 50 a leading edge 21, 31, 41 , 5 1 Rotating shaft 22, 32, 42, 5 2 First opening / closing wall 23, 33, 43, 5 3 2nd opening / closing wall CL Centerline of throttle body

Claims (6)

Intake port throttle body disposed adjacent to (5) (12) rotation axis in a (21,31,4 1) the throttle valve (20,30,4 0) provided swingably with a An internal combustion engine (1) including an injector (11) for spraying fuel from the throttle body (12) toward the intake port (5) and downstream of the throttle valve (20, 30, 40 ) ) Intake device (10)
The intake port (5) is provided on one side of the cylinder head (3) of the internal combustion engine (1), and the intake port (5) of the internal combustion engine (1) is disposed downstream from the diagonally upper side of the cylinder head (3). Forming a substantially cylindrical intake passage that is substantially linear toward the back of the intake valve (8a);
The throttle body (12) is disposed on the upstream side of the intake port (5) and forms a substantially linear intake passage having a substantially cylindrical shape,
The rotary shafts (21, 31, 41) are arranged in a direction perpendicular to the axis of the intake passage of the throttle body (12) in a plan view and perpendicular to the axis of the intake valve (8a) in a plan view. And
The throttle valve (20, 30, 40) is attached to the rotating shaft (21, 31, 41), and the side close to the injector (11) across the rotating shaft (21, 31, 41) is the intake port. (5) is rotated toward the downstream side, and the side far from the injector (11) is rotated toward the upstream side of the intake port (5),
The injector (11) has a spray port (11a) that opens below the throttle body (12) and below the axis of the throttle valve (20, 30, 40), so that the intake port (5 ) Is arranged to spray fuel toward the downstream side,
In the fully closed state of the throttle valve (20, 30, 40), the throttle valve on the side where the spray port (11a) of the injector (11) is disposed across the rotating shaft (21, 31, 41) The throttle valve (20, 30, 40) on the side where the spray port (11a) of the injector (11) is not disposed with respect to the open / close wall surface (22, 33, 43) of (20, 30, 40). Tip edges (20a, 30a, 40a) are arranged upstream of the intake port (5),
Wherein the leading edge (20a, 30a, 40 a) and the size of the gap of the throttle body (12) inner wall surface of (12a) and the throttle valve (20,30,4 0), the rotary shaft (21, 31, 41 ) of the internal combustion engine (1) characterized in that the side of the injector (11) on which the spray port (11 a) is arranged becomes smaller in a cross section perpendicular to the center in the longitudinal direction. Intake device (10). The throttle valve (20, 30, 40) has a fully closed set angle (θ1) on one side of the rotary shaft (21, 31, 41) when viewed from the axial direction of the rotary shaft (21, 31, 41). an intake device for an internal combustion engine (1) according to claim 1, fully closed set angle on the other side (.theta.2) is characterized by being configured differently (10). The throttle valve (20, 30, 40) has a first opening / closing wall (22, 32, 42) and a second opening / closing wall (23, 33, 42) as viewed from the axial direction of the rotating shaft (21, 31, 41). The intake device (10) for an internal combustion engine (1) according to claim 1 or 2 , characterized in that the two planes (43) are configured to have an angle (α) greater than 90 ° and less than 180 °. ). The throttle valve (20,30,4 0), the first closing wall (22,32,4 2) and the second closing wall (23,33,4 3) and said rotary shaft (21,31,4 1 ) intake device for an internal combustion engine (1) according to any one of claim 1 to 3, characterized in that it is formed on the opposite side (10). The throttle valve (20, 30, 40) is a straight planar structure as viewed in the axial direction of the rotary shaft (21, 31, 41), whereas a side across the rotation shaft (21, 31, 41) the direction in which the first opening and closing walls (22, 32, 42) and the other side of the second closing wall (23, 33, and 43) of orthogonal with the longitudinal center relative to the rotation axis (21, 31, 41) an intake device for an internal combustion engine (1) according to claim 1, characterized in that it is configured to have different lengths (10). The throttle body (12) disposed adjacent to the intake port (5) includes a throttle valve (50) having a rotating shaft (51) and swingably provided. In an intake device (10) of an internal combustion engine (1) comprising an injector (11) that sprays fuel toward the intake port (5) and downstream of the throttle valve (50),
The rotating shaft (51) is disposed so as to be biased toward the injector (11) with respect to the central axis (CL) of the throttle body (12),
The size of the gap between the inner wall surface (12a) of the throttle body (12) and the leading edge (50a) of the throttle valve (50) is in a cross section orthogonal to the rotation shaft (51) at the center in the longitudinal direction. An intake device (10) for an internal combustion engine (1), characterized in that the side of the injector (11) on which the spray port (11a) is arranged becomes smaller.

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