JP4850822B2 - Multi-cylinder engine intake system - Google Patents

Description

  The present invention relates to an intake device for a multi-cylinder engine, and more particularly to an intake device for a multi-cylinder engine having a surge tank whose internal space is divided into an upper portion and a lower portion.

  Conventionally, an engine having a surge tank in an intake system is generally known. Some surge tanks have an internal space divided into an upper part and a lower part, and a partition is provided between the upper part and the lower part. In such a surge tank, an intake branch pipe connected to one cylinder row of a multi-cylinder engine (for example, a V-type engine) having two cylinder rows composed of a plurality of cylinders is connected to an upper portion, and the other An intake branch pipe connected to the cylinder row is connected to the lower portion. An opening for communicating the upper portion and the lower portion is provided in a part of the partition wall in the surge tank, and an opening / closing valve for opening and closing the opening is provided in this opening. Then, by opening and closing the opening with the on-off valve, the effective intake pipe length that affects the cycle of the intake pulsation generated in the intake passage is switched, and this can be used to increase the charging efficiency due to the pulsation effect.

  By the way, it is preferable that the surge tank is generally disposed close to the intake port from the viewpoint of intake efficiency. However, in the V-type engine, the intake port is further provided in the upper center, and the intake and exhaust pipes are routed. From the viewpoint of the above, it is preferable that the engine is specifically disposed above the engine. This also applies to the surge tank in which the internal space is divided into the upper part and the lower part as described above. FIG. 8 schematically shows a vehicle mounting space when a surge tank or the like is to be disposed above the engine. In the present specification, the forward direction of the vehicle is described as “front (or front of the vehicle)” (direction F in the drawing), and the backward direction of the vehicle is described as “rear (or rear of the vehicle)” (direction R in the drawing). To do. In addition, the vertical upward direction of the vehicle will be described as “upward” (direction U in the drawing), and the downward direction of the vehicle in the vertical direction will be described as “downward” (direction D in the drawing).

  On the other hand, as shown in FIG. 8, the engine hood usually needs to be inclined downward toward the front of the vehicle from the viewpoint of securing the field of view of the vehicle driver. For this reason, in order to make the height of the whole engine hood low, it is necessary to make the height of the engine hood low especially in the engine hood front region. However, when the surge tank is arranged above the engine, it becomes necessary to raise the position of the engine hood so that the surge tank does not protrude upward. As a result, the design of the vehicle around the engine hood The degree of freedom is limited to a low level. In recent years, in order to protect pedestrians, etc., it is necessary to provide a cushioning material between the engine hood and the upper part of the engine body and surge tank. Therefore, the engine hood is placed at a higher position. There are also situations where you have to.

  On the other hand, in Patent Document 1, the height of the engine hood is effectively reduced even when a surge tank whose internal space is divided into an upper part and a lower part is used as the surge tank. An intake device for a multi-cylinder engine that can be used has been proposed.

JP 2005-325696 A

  FIG. 9 is a diagram schematically showing a main part of an intake device 10X (hereinafter simply referred to as intake device 10X) of a multi-cylinder engine. The intake device 10X is substantially the same as the intake device of a multi-cylinder engine disclosed in Patent Document 1. As shown in FIG. 9, the intake device 10X includes an ACIS valve 1, an intake pipe 12, a surge tank 13X, and a plurality of intake branch pipes 14 (from intake branch pipes 141 to 146). In the intake device 10X, the actuator 2 of the ACIS valve 1 is provided so as to be positioned in front of the vehicle, and is provided on the side facing the intake pipe 12 that introduces intake air into the surge tank 13X. The intake pipe 12 is connected to the surge tank 13X from behind the vehicle so as to go around.

  FIG. 10 is a diagram schematically showing the ACIS valve 1 as a single unit. The ACIS valve 1 includes an actuator 2, a valve shaft 3, and a valve body (corresponding to an on-off valve in claims) 4. The actuator 2 is connected to the valve shaft 3. The valve shaft 3 pivotally supports a plate-like valve body 4 in a butterfly valve shape. The width of the valve body 4 is the largest on the actuator 2 side, and gradually decreases as the distance from the actuator 2 increases. This is to improve the sealing performance by the valve body 4 when the opening of the partition wall is closed. In the ACIS valve 1, the portion on the actuator 2 side is the portion with the largest volume (the portion with the highest height). For this reason, the ACIS valve 1 is provided so as to pierce the surge tank 13 obliquely from the front of the vehicle as shown in FIG. In other words, the ACIS valve 1 is more difficult to dispose in front of the vehicle due to the portion on the actuator 2 side with the largest volume.

  In such an intake device 10X, the intake air introduced into the surge tank 13X circulates as follows. FIG. 11 is a diagram schematically showing the intake device 10X together with the flow of intake air introduced into the surge tank 13X. Among these, FIG. 11A schematically shows the intake device 10X as in FIG. 8, and FIG. 11B shows the intake device 10X when the ACIS valve 1 is open (for example, at high speed) as the valve shaft 3. This is schematically shown in a cross section orthogonal to the. Further, in FIG. 11C, the intake device 10 </ b> X when the opening of the ACIS valve 1 is approximately 90 ° is schematically shown in a cross section orthogonal to the valve shaft 3. FIG. 11D schematically shows the intake device 10X when the ACIS valve 1 is closed (for example, at a low speed) for reference.

  As shown in FIG. 11A, in the intake device 10X, the distal end of the valve body 4 is opposed to the intake air introduced into the surge tank 5X due to the arrangement of the ACIS valve 1. For this reason, in the intake device 10X, when the valve body 4 opens the ACIS valve 1, it becomes a flow resistance of the intake air. Further, when the flow of the intake air at this time is confirmed in FIG. 11B, due to the arrangement of the ACIS valve 1, particularly when the ACIS valve 1 is opened, the lower portion 13bX is divided by the valve body 4 on the right side in the figure. It can be seen that the intake air that tries to flow through the space of the part is blocked by the valve body 4.

  In this regard, in order to avoid that the valve body 4 becomes a flow resistance of the intake air as shown in FIG. 11B, the opening of the ACIS valve 1 is set to approximately 90 ° as shown in FIG. 11C. It may be possible to do this. However, in this case, at the upper portion 13aX and the lower portion 13bX, the ends of the valve body 4 are close to the wall surface of the surge tank 13X to narrow the intake air flow path. Will be an obstacle. Further, it is conceivable to secure a flow path by increasing the height of the surge tank 13X. However, in the surge tank 13X in which the ACIS valve 1 is arranged as described above, the mounting space is related. Moreover, it is difficult to increase the height.

  That is, the intake device 10X has a problem in that the valve body 4 becomes a flow resistance of the intake air as described above when the ACIS valve 1 is opened in order to ensure the degree of freedom in designing the vehicle around the engine hood.

  In the intake device 10X, as described above, the ACIS valve 1 is provided so as to pierce the surge tank 13X obliquely from the front of the vehicle. For this reason, in the intake device 10X, the opening of the partition wall cannot be provided so as to extend to the vicinity of the position corresponding to the cylinder located most forward of the vehicle. Instead, the cylinder (here, No. 1) located most forward of the vehicle. The shape of the portion corresponding to (cylinder) is formed in a pipe shape and extended from the opening of the partition wall (see FIG. 12), so that the charging efficiency is improved by the pulsation effect while ensuring the degree of freedom in design.

  However, the portion formed like a pipe in this way functions like an intake branch pipe. FIG. 13 shows the intake noise of each cylinder in terms of frequency when the intake device 10X is applied to a V-type 6-cylinder multi-cylinder engine. In the intake device 10X, due to the shape of the surge tank 13X formed as described above, the intake pipe length between the surge tank 13X and the first cylinder is extended, and as a result, the resonance frequency becomes the first. It turns out that it has fallen in the cylinder. Although the same tendency is seen in the second cylinder, the length of the portion formed in the pipe shape is shorter for the second cylinder than for the first cylinder, so the degree of decrease is 1 It is smaller than the number cylinder.

  As described above, in the intake device 10X, the ACIS valve 1 is provided in such a manner that the ACIS valve 1 is obliquely inserted into the surge tank 13X from the front of the vehicle in order to ensure the degree of design freedom of the vehicle around the engine hood. As a result of the shape of the surge tank 13X formed in a pipe shape, the intake tank length between the surge tank 13X and the cylinder is unequal, and as a result, the intake sound is deteriorated. In addition, there is a problem in that the charging efficiency is reduced and the maximum output torque of the engine is reduced.

  Accordingly, the present invention has been made in view of the above problems, and when a surge tank having an internal space divided into an upper part and a lower part is used as the surge tank, the degree of freedom in designing the vehicle around the engine hood. While improving the intake noise of the multi-cylinder engine that can reduce the flow resistance of the intake air and the design freedom of the vehicle around the engine hood, improve the intake noise and increase the maximum output torque of the engine An object of the present invention is to provide an intake device for a multi-cylinder engine that can be realized.

In order to solve the above problems, the present invention is arranged at a position higher than the cylinder head of the multi-cylinder engine when mounted on a multi-cylinder engine having two cylinder rows each composed of a plurality of cylinders. together, the internal space and the surge tank is divided into an upper portion and a lower portion, said upper portion and said opening and closing valve for opening and closing an opening provided in the partition wall partitioning the lower portion, of the on-off valve An intake device for a multi-cylinder engine connected to an end opposite to the tip and configured to open and close the open / close valve, wherein the actuator includes the actuator of the open / close valve is provided on the intake pipe side for guiding intake air to the surge tank than the tip, the multi-cylinder engine, under the engine hood is inclined downwardly toward the front of the vehicle, each When the cylinders constituting the cylinder row are arranged in the front-rear direction of the vehicle, and the surge tank is attached to the multi-cylinder engine, the actuator is more than the tip of the on-off valve. It is provided so that it may be located behind .

According to the present invention, by providing the actuator in this way, the on-off valve can be provided so that the tip of the on-off valve does not face the flow of intake air. For this reason, according to the present invention, it is possible to prevent the front end of the on-off valve from obstructing intake when the on-off valve is opened. In addition, an ACIS valve having an on-off valve and an actuator is provided with an actuator that is the most volumetric part so as to be positioned at the rear of the vehicle. The height of the apparatus can be made rational, and thereby the degree of freedom in designing the vehicle around the engine hood can be suitably secured. Further, according to the present invention, it is possible to solve the limitation of the arrangement of the ACIS valve due to the actuator part having the largest volume among the ACIS valves. Therefore, according to the present invention, the opening of the partition wall can be formed to extend to the vicinity of the cylinder located in front of the vehicle without being limited to the arrangement of the ACIS valve. It is also possible to communicate with the intake branch pipe without forming a surge tank extending in a pipe shape with respect to the cylinder located in front. Therefore, according to the present invention, it becomes possible to make the intake pipe length between the surge tank and the cylinder equal to the original equal length by the equal length intake branch pipe, thereby improving the intake noise and the maximum output torque of the engine. Improvements can also be made.

Furthermore, according to the present invention, it is possible to secure a large opening area of the opening provided in the partition wall by providing the actuator so as to be located in the rear of the vehicle with a sufficient mounting space. Therefore, according to the present invention, the engine output performance can also be improved by this, and at the same time, it is possible to avoid the valve body 4 from becoming a flow resistance of the intake air as shown in FIG. In addition, according to the present invention, it is possible to solve the problem that the arrangement of the ACIS valve is restricted due to the actuator part having the largest volume. Therefore, the on-off valve is arranged so as to follow the flow line of the intake air flowing through the surge tank. This makes it possible to reduce the intake resistance by forming a smooth intake air flow.

In the present invention, the width of the on-off valve may be the largest on the actuator side and gradually decrease with distance from the actuator. According to this structure, the design freedom degree of the vehicle around an engine hood can be ensured more suitably.

  According to the present invention, when a surge tank whose internal space is divided into an upper part and a lower part is used as the surge tank, the flow resistance of the intake air is reduced while ensuring the degree of freedom in designing the vehicle around the engine hood. Multi-cylinder engine intake device that can be reduced, and multi-cylinder engine intake device that can improve the intake noise and increase the maximum output torque of the engine while ensuring the degree of freedom in designing the vehicle around the engine hood Can provide.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram schematically showing an intake device (hereinafter simply referred to as an intake device) 10 of a multi-cylinder engine mounted on a vehicle 100. The intake device 10 is disposed in an engine room 101 and includes an ACIS valve 1 (not shown in FIG. 1), an air cleaner 11, an intake pipe 12, a surge tank 13, and a plurality of intake branch pipes 14. . The intake gas (intake air) passes through these and flows into each intake port of the engine 3 (not shown in FIG. 1). The ACIS valve 1 is provided in the surge tank 13, and this ACIS valve 1 is the same as that shown in FIG. The intake pipe 12 is provided with a throttle valve 15 for adjusting the flow rate of intake air flowing through the intake pipe 12.

  2 to 5 are views showing the intake device 10 mounted on the engine 3. 2 is a partial plan view of the intake device 10, FIG. 3 is a partial front view of the intake device 10, and FIGS. 4 and 5 are partial side views of the intake device 10 viewed from one side and the opposite side. It is. In the illustrated embodiment, a V-type six-cylinder engine 3 as a multi-cylinder engine, that is, an engine 3 in which two cylinder rows 31 and 32 each having three cylinders are arranged at a constant angle is shown. The engine 3 is arranged vertically in the engine room 2, that is, the cylinders constituting the cylinder rows 31 and 32 are arranged in the front-rear direction. The present invention is not limited to the engine 3 and is applied to an appropriate multi-cylinder engine (for example, a V-type eight-cylinder engine, a horizontally opposed six-cylinder engine, etc.) having two cylinder rows each composed of a plurality of cylinders. Good. The present invention can also be applied to an appropriate engine arranged horizontally.

  As shown in FIGS. 2 to 5, the intake pipe 12 branches into two branch pipes, an upper branch pipe 17 and a lower branch pipe 18, at an intake pipe branching portion 16 downstream of the throttle valve 15. The upper branch pipe 17 is located above the lower branch pipe 18. The internal space of the surge tank 13 is divided into two parts, an upper part 13a and a lower part 13b, by a partition wall 19 (see FIG. 4). The upper part 13a is located above the lower part 13b. An upper branch pipe 17 is connected to the upper portion 13a, and a lower branch pipe 18 is connected to the lower portion 13b. The upper branch pipe 17 and the lower branch pipe 18 are connected to the rear of the upper portion 13a and the rear of the lower portion 13b, respectively. In the present embodiment, the upper portion 13a and the lower portion 13b are integrally formed. However, the present invention is not limited to this, and the upper portion 13a and the lower portion 13b are formed as separate bodies and then connected together. The surge tank 13 may be formed.

  The surge tank 13 is located above the head covers 33 and 34 of the cylinder head of the engine 3. In particular, in this embodiment, the surge tank 13 is disposed above the head cover 33 corresponding to one cylinder row (hereinafter referred to as “first cylinder row”) 31 of the engine 3. The surge tank 13 is arranged at such a position for the following reason. That is, in the V-type engine, the intake port is arranged in the center of the engine due to its configuration. On the other hand, the length of the intake branch pipe for optimally obtaining the pulsation effect as described later is determined, and the length of the intake branch pipe is used to equalize the distribution of the intake gas to each cylinder. It is necessary to equalize the thickness. If the surge tank is to be communicated with the intake port located in the center of the engine while satisfying these conditions, the surge tank is necessarily arranged above the head cover of the cylinder head of the engine.

  An opening 20 is provided in the partition wall 19 between the upper portion 13a and the lower portion 13b of the surge tank 13, and thus the upper portion 13a and the lower portion 13b communicate with each other through the opening 20. The opening 20 is provided with a valve body 4 for opening and closing the opening 20. Therefore, when the valve body 4 is opened, the upper portion 13a and the lower portion 13b communicate with each other, and conversely, when the valve body 4 is closed, the upper portion 13a and the lower portion 13b do not communicate with each other. . The opening 20 is provided so as to extend to the vicinity of the position corresponding to the first and second cylinders which are the cylinders located most forward of the vehicle.

  This is because the intake device 10 is provided so that the actuator 2 is positioned at the rear of the vehicle as will be described in detail later, and therefore, the arrangement of the ACIS valve 1 ensures the degree of freedom in designing the vehicle 100 around the engine hood 102. For this reason, the ACIS valve 1 can be disposed in correspondence with the opening 20 thus provided, without any particular limitation. Further, in this connection, since the opening 20 is formed in this manner, the charging efficiency can be improved by the pulsation effect. Therefore, the surge tank 13 is provided for each cylinder (in particular, the first and second cylinders located in front of the vehicle). The portion corresponding to is formed in a pipe shape and is not particularly stretched, and this is different from the surge tank 13X described above.

  Three intake branch pipes 141 to 146 are connected to the upper part 13a and the lower part 13b of the surge tank 13, respectively. The intake branch pipes 141, 143, and 145 connected to the upper portion 13a are respectively connected to the cylinders of the first cylinder row 31 via the intake port 35 provided in the cylinder head, and are connected to the lower portion 13b. Reference numerals 142, 144, and 146 communicate with cylinders in a cylinder row 32 (hereinafter referred to as “second cylinder row”) different from the first cylinder row 31 through an intake port 36 provided in the cylinder head.

  Assuming that the three cylinders of the first cylinder row 31 are the first cylinder, the third cylinder, and the fifth cylinder from the front to the rear, these cylinders include a first intake branch pipe 141, a third intake branch pipe 143, and a fifth cylinder. The intake branch pipes 145 communicate with each other. Further, assuming that the three cylinders in the second cylinder row 31 are the second cylinder, the fourth cylinder, and the sixth cylinder from the front to the rear, these cylinders include a second intake branch pipe 142, a fourth intake branch pipe 144, The sixth intake branch pipes 146 communicate with each other. The intake pipe 12 connected to the surge tank 13 is located behind the intake branch pipes 14 in the vicinity of the connection portion with the surge tank 13.

  When the valve body 4 of the ACIS valve 1 is appropriately opened and closed, the combustion chamber of the engine 3 is effectively utilized by utilizing the pressure fluctuation in the intake passage (the passage including the intake branch pipe 14, the surge tank 13, the intake pipe 12, etc.). The intake efficiency to 37 can be increased. The reason is as follows. That is, as a method of using the pressure fluctuation in the intake passage, a method using a pulsation effect (inertia supercharging effect) that occurs in the intake branch pipe 14 and a pulsation effect that occurs in the path from the intake branch pipe to the intake pipe branching portion. There is a method using the (resonance supercharging effect). The engine speed that can utilize these effects (hereinafter referred to as “engine speed”) is limited, and the engine speed at which resonance supercharging occurs is lower than the engine speed at which inertial supercharging occurs. .

  The magnitudes of the inertia supercharging effect and the resonance supercharging effect are affected by the magnitude of pulsation generated in the surge tank. That is, as the volume of the surge tank is larger and the number of cylinders communicating with the surge tank is larger, the pulsation generated in the surge tank is weakened, so that the inertial supercharging effect is strengthened, but the resonance supercharging effect is weakened. In the present embodiment, by opening the valve body 4, the upper portion 13a and the lower portion 13b communicate with each other, and both the portions 13a and 13b function as one surge tank. Therefore, the volume of the surge tank is substantially increased and the number of cylinders communicating with the surge tank is substantially increased as compared with the case where the upper portion 13a and the lower portion 13b function as separate surge tanks. The pay effect is strengthened. On the contrary, by closing the valve body 4, the upper part 13a and the lower part 13b are separated, and these parts 13a and 13b function as separate surge tanks. Therefore, since the volume of each part 13a, 13b is small and the number of cylinders communicating with each part 13a, 13b is small, the resonance supercharging effect is strengthened. Therefore, as described above, the inertia supercharging effect and the resonance supercharging effect can be effectively used by opening and closing the valve body 4 in accordance with the engine speed, so that the intake efficiency into the combustion chamber 37 is increased.

  By the way, it is necessary to make the position of the engine hood 102 low from the viewpoint of increasing the degree of freedom in designing the vehicle 100 around the engine hood 102 or securing the visual field of the vehicle driver. However, since the surge tank 13 is disposed above the engine 3, the height of the entire equipment in the engine room 2 (including the engine, the intake device, etc., hereinafter referred to as “the whole engine equipment”) is high. Inevitably, the position of the engine hood 102 becomes high.

  Therefore, in order to lower the position of the engine hood 102, it is necessary to reduce the height of the entire engine device in the region where the surge tank 13 is disposed. However, since the engine hood 102 is generally tilted downward toward the front from the viewpoint of securing the vehicle driver's field of view, in order to reduce the overall height of the engine hood 102, the engine engine as a whole is particularly advanced toward the front. Need to be low. Therefore, it is necessary to lower the position of the upper surface of the surge tank 13 especially in the front region of the surge tank 13, and conversely, if the position of the upper surface of the surge tank 13 is decreased in the front region of the surge tank 13, The overall height of the engine hood 102 can be reduced.

On the other hand, in the intake device 10, the actuator 2 of the ACIS valve 1 is arranged as shown below. FIG. 6 is a diagram schematically showing the main part of the intake device 10 together with the flow of intake air. In the intake device 10, the actuator 2 is provided on the intake pipe 12 side that guides intake air to the surge tank 13. In the intake device 10, by providing the actuator 2 on the intake pipe 12 side in this way, the tip of the valve body 4 can be prevented from facing the flow of intake air introduced into the surge tank 13 when the ACIS valve 1 is opened. . For this reason, in the intake device 10, it can suppress that the valve body 4 becomes distribution | circulation resistance of intake, and can reduce distribution | circulation resistance of intake.

  As shown in FIG. 6, in the intake device 10, when the actuator 2 is attached to the engine 3, the intake device 10 is provided so as to be positioned behind the vehicle with a sufficient mounting space. For this reason, in the intake device 10, the arrangement of the ACIS valve 1 is not particularly limited in order to ensure the degree of freedom in designing the vehicle 100 around the engine hood 102, and is aligned with the streamline of the intake air flowing through the surge tank 13. In this way, the valve body 14 can be arranged. In this respect, in the intake device 10 in which the valve body 4 is arranged in this way, the intake air smoothly flows in the surge tank 13 as shown in FIG. 6, and this can also reduce the intake flow resistance.

  Further, in the intake device 10, the actuator 2, which is the most volumetric part of the ACIS valve 1, is provided so as to be located at the rear of the vehicle, so that the engine hood 102 that is inclined downward toward the front of the vehicle is provided. Thus, the height of the entire engine device including the intake device 10 can be made rational, and thus the degree of freedom in designing the vehicle 100 around the engine hood 102 can be suitably ensured. In addition, the valve body 4 is formed in a shape that has the largest width on the actuator 2 side and gradually decreases as the distance from the actuator 2 increases, so that the actuator 2 is positioned on the rear side of the vehicle even in light of this shape. Providing such a valve body 4 ensures a more suitable degree of freedom in designing the vehicle 100 around the engine hood 102.

  This is also apparent from FIGS. 4 and 5. In these drawings, a broken line indicates a lower limit position where the engine hood 102 can be disposed in the present invention (more precisely, a lower limit position where a cushioning material disposed below the engine hood 102 can be disposed). From these figures, by providing the actuator 2 that is the most voluminous portion of the ACIS valve 1 so as to be located at the rear of the vehicle, the intake device 10 is provided to the engine hood 102 that is inclined downward toward the front of the vehicle. It can be seen that the overall height of the engine equipment including the engine hood can be made reasonable, and thereby the degree of freedom in designing the vehicle 100 around the engine hood 102 can be suitably secured.

  By the way, as shown in FIG. 5, the upper portion 13a of the surge tank 13 is formed such that its height gradually increases toward the rear. Accordingly, the positions at which the intake branch pipes 141, 143, and 145 are connected to the upper portion 13a of the surge tank 13 are also higher in the rear intake branch pipe. On the other hand, the positions where these intake branch pipes 141, 143, 145 are connected to the intake port 35 of the engine 3 have the same height. Therefore, the length in the vertical direction in which the intake branch pipes 141, 143, and 145 connected to the upper portion 13a extend is longer in the rear intake branch pipe. That is, as shown in FIG. 5, the length of the intake branch pipe in the vertical direction becomes longer in the order of 141, 143, and 145.

  On the other hand, the horizontal length of each intake branch pipe 141, 143, 145 connected to the upper portion 13a is shorter as the rear intake branch pipe. That is, as shown in FIG. 2, the length of the intake branch pipe in the horizontal direction becomes longer in the order of 145, 143, and 141. This is because the upper portion 13a is shifted rearward so that the intervals between the connection points of the intake branch pipes 141, 143, and 145 to the upper portion 13a are the intake ports to which the intake branch pipes 141, 143, and 145 are connected. This is because it is shorter than the interval between 35.

  As described above, in the intake branch pipes 141, 143, and 145 connected to the upper portion 13a, the rear intake branch pipes are longer in the vertical direction and shorter in the horizontal direction. As a result, the intake branch pipes 141, 143, and 145 connected to the upper portion 13a can be made equal in length, so that the distribution of intake gas to each cylinder is made uniform and the pulsation effect generated in the intake path Can be used effectively to increase the filling efficiency.

  In this regard, in the intake device 10 in which the actuator 2 is provided at the rear of the vehicle, the portion corresponding to each cylinder (particularly the first and second cylinders located at the front of the vehicle) of the surge tank 13 as described above. Since it is formed in a pipe shape and is not particularly stretched, the intake pipe 14 between the surge tank 13 and the cylinder can be made the original length with the same length of the intake branch pipe 14, thereby increasing the charging efficiency. The maximum output torque of the engine can be improved. Furthermore, in the air intake measure 10, since the actuator 2 is provided so as to be located at the rear of the vehicle with a sufficient mounting space, a large opening area of the opening 20 provided in the partition wall 19 can be secured. Engine output performance can be improved.

  In addition, by providing the actuator 2 so as to be located at the rear of the vehicle, the intake tank pipe 14 having the same length as described above can make the intake tank length between the surge tank 13 and the cylinders equal to the original length. Sound can also be improved. FIG. 7 shows the intake sound of each cylinder in terms of frequency when the intake device 10 is applied to the engine 3. In the intake device 10, it is possible to make the intake tank length between the surge tank 13 and the cylinders equal to the original equal length by the equal length intake branch pipes 14, and it can be seen that the resonance frequencies are almost equal between the cylinders. Thereby, the turbidity of the intake sound can be improved.

  As described above, when the surge tank 13 in which the internal space is divided into the upper portion 13a and the lower portion 13b is used as the surge tank, the intake device 10 ensures a degree of freedom in designing the vehicle 100 around the engine hood 102. In addition, the intake flow resistance can be reduced, and the intake sound can be improved and the maximum output torque of the engine can be improved while the design freedom of the vehicle 100 around the engine hood 102 is secured.

  The embodiment described above is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

1 is a diagram schematically showing an intake device 10 mounted on a vehicle 100. FIG. 2 is a partial plan view of the intake device 10. FIG. 2 is a partial front view of the intake device 10. FIG. It is the partial side view of the intake device 10 seen from one side. FIG. 5 is a partial side view of the intake device 10 as viewed from the side opposite to FIG. 4. It is a figure which shows typically the principal part of the intake device 10 with the flow of intake air. The intake sound of each cylinder when the intake device 10 is applied to the engine 3 is shown by frequency. It is a figure which shows typically the mounting space of the vehicle at the time of trying to arrange | position a surge tank etc. above an engine. It is a figure which shows an example of the F / B correction coefficient FAF set based on the flowchart shown in FIG. It is a figure which shows typically the principal part of the intake device 10X. It is a figure which shows typically the air intake apparatus 10X with the flow of the intake air introduce | transduced into the surge tank 13X. It is explanatory drawing about the shape of the intake device 10X. It is a figure which shows the intake sound of each cylinder at the time of applying the intake device 10X to a multi-cylinder engine of V type 6 cylinders with a frequency.

Explanation of symbols

1 ACIS valve 2 Actuator 13 Surge tank 14 Intake branch pipe

Claims (2)

When mounted on a multi-cylinder engine having two cylinder rows each composed of a plurality of cylinders, the multi-cylinder engine is disposed at a position higher than the cylinder head, and the internal space has an upper portion and a lower portion. A surge tank that is divided into
An on-off valve for opening and closing an opening provided in a partition partitioning the upper part and the lower part;
An actuator connected to an end opposite to the tip of the on- off valve, and for opening and closing the on-off valve;
An intake device for a multi-cylinder engine configured with
The actuator is provided on the intake pipe side that guides intake air to the surge tank from the tip of the on-off valve ;
The multi-cylinder engine is arranged below an engine hood inclined downward toward the front of the vehicle so that the cylinders constituting each of the cylinder rows are arranged in the front-rear direction of the vehicle, and the surge tank is An air intake apparatus for a multi-cylinder engine , wherein the actuator is provided so as to be positioned rearward of the vehicle with respect to the tip of the on-off valve when attached to the multi-cylinder engine. An intake device for a multi-cylinder engine according to claim 1,
The multi-cylinder engine intake device characterized in that the width of the on-off valve is the largest on the actuator side, and gradually decreases with distance from the actuator .

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