JP2007016657A - Intake device for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To materialize a desired flow rate and enhancement of the gas flow of a tumble flow in a cylinder with a simple structure. <P>SOLUTION: In an intake device for an engine, an intake port 50 is connected to a cylinder 20 of the engine and an intake valve 70 opens and closes a tip in a downstream side of an intake port 50. The intake device includes a bulkhead 200 provided along a longitudinal direction of the intake port 50 to partition the intake port 50 into two regions in a cross section thereof, a lower end part 220 provided in a downstream side of the bulkhead 200 and formed by shape memory alloy deforming in a shape choking a second flow passage 52 under low temperature, and an intake control valve 300 provided in a conduit forming an intake port 50 and opening and closing a first flow passage 51 partitioned by the bulkhead 200. A sliding direction of a piston 100 in a cylinder 20 is defined as up and down direction, and two regions are partitioned in the up and down direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an intake device for an internal combustion engine including an intake port connected to a cylinder, and in particular, an intake device that enhances gas flow such as a tumble flow (longitudinal vortex) in a cylinder according to the operating state of the internal combustion engine. About.

  For example, in order to achieve stable combustion of a lean air-fuel mixture in a spark ignition internal combustion engine, the gas flow in the cylinder such as tumble flow or swirl flow (lateral vortex) is very important, and gas in a wider operating range. It is necessary to be able to strengthen the flow.

  In particular, in the operating range of an internal combustion engine, in a low load range where the throttle opening is small and the amount of intake air is accordingly small, the air-fuel mixture is generally set to be slightly darker to stabilize combustion, so fuel consumption and emissions are reduced. Tend to get worse. As a measure to improve fuel efficiency and emissions, it is effective to generate a swirling flow in the intake air in the cylinder and promote combustion by strong turbulence, and to generate a tumble flow and a swirl flow in the intake air. Yes.

  Here, the swirl flow causes the intake air to swirl along the peripheral wall of the cylinder, and the effect of making the intake air uniform is high, but the effect of promoting combustion by generating turbulent flow is low. Tumble flow, on the other hand, swirls the intake air along the axial direction of the cylinder. The tumble flow collapses in the latter half of the compression stroke and generates strong turbulence. It is valid.

  In order to reinforce the gas flow (swirl flow, tumble flow) in the cylinder, the intake flow that flows through the intake port is reduced by using an intake control valve that blocks a part of the passage section of the intake port. There is a way to offset to one side of the. For example, in order to generate a tumble flow, an intake control valve is arranged on the lower side of the intake port, and the intake air is shifted toward the upper side of the intake port, whereby the tumble flow in the cylinder is strengthened. .

  When the gas flow is strengthened, the passage cross-sectional area of the intake port is substantially reduced by the intake control valve, and the ratio of the effective passage cross-sectional area to the base intake port cross-sectional area is defined as the “opening ratio”. In general, the smaller the aperture ratio, the higher the gas flow. However, if the aperture ratio is small, the fluid resistance increases and the amount of intake air that can be sucked into the cylinder decreases. Therefore, the operating conditions in which the intake control valve can be closed and the gas flow can be strengthened are in a relatively narrow range. It will be limited to. Japanese Patent Application Laid-Open No. 2004-124836 discloses an intake device for an internal combustion engine that can enhance gas flow in a cylinder without excessively reducing the aperture ratio. The intake device for an internal combustion engine is an intake device for an internal combustion engine in which an intake port is connected to a cylinder of the internal combustion engine, and an intake valve opens and closes a tip on the downstream side of the intake port. Inlet control that opens and closes a partition provided along the longitudinal direction of the intake port so as to be divided into two regions, and one flow path that is located near the upstream end of the partition and that is partitioned by the partition A valve and a communication path that communicates the two flow paths partitioned by the partition wall with each other at a position close to the intake control valve.

According to the intake device of the internal combustion engine, when the intake control valve is in the closed position where one of the flow paths is shielded, the intake air flows to the cylinder side only through the other flow path. A relatively large amount of intake air flows from the offset position into the cylinder. At the same time, when the intake control valve throttles the intake flow, a local pressure drop occurs downstream of the intake control valve and acts on the communication path. Therefore, a pressure difference is generated between the downstream end portion of one flow path shielded by the intake control valve and the communication path, and intake air is sucked from the end portion, and reversely toward the upstream side of the intake port. And merges into the other flow path through the communication path. That is, a part of the intake air returns to the upstream side through the blocked flow path. Therefore, the flow rate or flow velocity imbalance of the intake flow passing around the intake valve is further increased, and the gas flow in the cylinder is effectively enhanced. As a result, according to the intake device of the internal combustion engine, the gas flow in the cylinder can be effectively improved by recirculating part of the intake air through the flow path blocked by the intake control valve. A stronger gas flow can be obtained without reducing the opening ratio of the control valve. Therefore, an increase in pumping loss due to an increase in fluid resistance is suppressed, and a large amount of intake air flowing into the cylinder can be secured, so that the gas flow can be enhanced in a wide operating range.
JP 2004-124836 A

  However, in the intake device disclosed in Patent Document 1, the intake control valve must be held at an intermediate position in the intermediate load region (intermediate flow rate region). In this case, in addition to controlling the actuator that rotationally drives the intake control valve and stopping the actuator at the start end (this side is the high flow rate side) and the end point (this side is the low flow rate side), the actuator Must be stopped between them. For example, in the case where the actuator is a motor, it is necessary to provide a stopper between the start end and the end position, and to control the motor between the start end and the end in addition to rotating the motor forward and backward. A control mechanism for realizing such control is required.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to realize a desired flow rate and enhancement of air flow in a cylinder such as a tumble flow with a simple configuration. An air intake device is provided.

  An intake device according to a first invention is an intake device for an internal combustion engine in which an intake port is connected to a cylinder of the internal combustion engine, and an intake valve opens and closes a tip on the downstream side of the intake port. In this intake device, a partition provided along the longitudinal direction of the intake port so as to divide the intake port into a first flow path and a second flow path in its cross section, and a pipe line forming the intake port An opening / closing mechanism that opens and closes the first flow path, and a variable mechanism that is provided near the downstream end of the partition wall and changes the cross-sectional area of the second flow path. The first flow path and the second flow path are divided into two in the vertical direction, with the sliding direction of the piston in the cylinder as the vertical direction.

  According to the first invention, the intake port is divided into two in the vertical direction, the first flow path and the second flow path with the sliding direction of the piston in the cylinder as the vertical direction. Of these two flow paths, the first flow path is either opened or closed by an opening / closing mechanism. Therefore, the actuator that drives the opening / closing mechanism need not hold the opening / closing mechanism at an intermediate position. In the vicinity of the downstream end of the partition wall, a variable mechanism is provided that changes (squeezes and narrows) the cross-sectional area of the second flow channel, which is the other flow channel. By using a shape memory alloy or the like that memorizes the shape of this variable mechanism with temperature, at least the following three states can be easily realized. The first state in which the first flow path is opened and the second flow path is opened, the first flow path is closed, and the second flow path is opened and not throttled. This is a third state in which the first flow path is closed and the second flow path is opened and throttled. In particular, by narrowing the cross-sectional area of the second flow path on the downstream side (because it is close to the combustion chamber where tumble flow is to be generated), tumble flow with a small amount of intake air during cold is effectively generated. be able to. As a result, it is possible to provide an intake device for an internal combustion engine that achieves a desired flow rate and enhancement of airflow in the cylinder such as a tumble flow with a simple configuration.

  In the intake device according to the second invention, in addition to the configuration of the first invention, the variable mechanism is made of a shape memory alloy, and changes to a shape that narrows the cross-sectional area of the second flow path at a low temperature.

  According to the second aspect of the invention, since the variable mechanism that changes the shape of the second flow path when it is cold (low temperature) is formed of the shape memory alloy, an actuator for narrowing the second flow path is required. Without strengthening, it is possible to enhance the tumble flow.

  In addition to the configuration of the second invention, the intake device according to the third invention is a first state in which the first flow path is opened by the opening / closing mechanism and the second flow path is not throttled by the variable mechanism. The first flow path is closed by the opening / closing mechanism, and the second flow path is not restricted by the variable mechanism, the first flow path is closed by the opening / closing mechanism, and the first flow path is closed by the variable mechanism. A third state in which the two flow paths are narrowed is realized.

  According to the third invention, the variable mechanism changes its shape depending on the temperature, either the opening / closing mechanism is closed (only the second flow path) or opened (the first flow path and the second flow path). Thus, in the case of only the second flow path, one of two states (total of three states), which is not restricted by the variable mechanism or restricted, can be easily realized.

  In addition to the configuration of the third aspect of the invention, the intake device according to the fourth aspect of the present invention includes a first state and a second state corresponding to three operating regions set in advance based on the operating state of the internal combustion engine. And a control unit for switching the third state.

  According to the fourth aspect of the invention, the control unit can realize an appropriate intake passage state corresponding to the operating state of the internal combustion engine.

  In the intake device according to the fifth aspect of the invention, in addition to the configuration of the fourth aspect of the invention, the control unit controls the opening / closing mechanism so as to be in the first state corresponding to the first operation region, Controlling the opening / closing mechanism to be in the second state corresponding to the second operating region, and controlling the opening / closing mechanism to be in the third state corresponding to the third operating region; In the first operation region, the intake air amount is large, and in the third operation region, the temperature of the internal combustion engine is low, and the state of the opening / closing mechanism in the second state is the same as the state of the opening / closing mechanism in the third state. is there.

  According to the fifth aspect of the present invention, when the intake air amount is large, when the temperature of the internal combustion engine is low so that both the first flow path and the second flow path are in the first state opened ( In the cold state, the switching can be easily performed so that only the second flow path restricted by the variable mechanism formed of the shape memory alloy is opened.

  In the intake device according to the sixth aspect of the invention, in addition to the configuration of the fifth aspect of the invention, the opening / closing mechanism has a rotating shaft that rotates the valve body about the position of the wall surface of the conduit, In the third state, the variable flow mechanism formed of a shape memory alloy is deformed into a low-temperature state, thereby narrowing the second flow path. The second end portion of the flat plate opposite to the first end portion is in contact with the partition wall so that the first flow path is closed, and in the second state, is formed of a shape memory alloy. Since the variable mechanism does not deform into a low-temperature shape, the second flow path is not throttled, and the second end opposite to the first end of the flat plate comes into contact with the partition wall to cause the first flow. The path is configured to be closed, and in the first state, the variable mechanism formed of the shape memory alloy has a low temperature Together with the second flow path by not deform to the shape of the state is not throttled, the flat plate is set along parallel to the wall surface of the conduit, the first flow path and second flow path is formed.

  According to the sixth aspect of the invention, the rotation of the valve body can realize only the state of closing or opening the first flow path, and does not need to realize the intermediate state. When the first flow path is closed, the variable mechanism realizes whether or not the second flow path is restricted by using the action of the shape memory alloy whose shape changes depending on the temperature. As a result, it is possible to provide an intake device for an internal combustion engine that achieves a desired flow rate and enhancement of airflow in the cylinder such as a tumble flow with a simple configuration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  An intake device for an internal combustion engine according to the present embodiment will be described together with an internal combustion engine to which the intake device is applied. In addition, the internal combustion engine shown below is demonstrated as a spark ignition type gasoline engine. The injector provided in the engine may be an injector that injects fuel into the intake port or an injector that injects fuel into the cylinder. An engine having both of these injectors may also be used.

  FIG. 1 shows an overall configuration when an intake device for an internal combustion engine according to the present embodiment is applied to an intake device for an in-cylinder direct injection spark ignition gasoline engine. This intake device is intended to enhance the tumble flow as a gas flow.

  As shown in FIG. 1, a cylindrical cylinder 20 is formed in the cylinder block 10, and a vent roof type combustion chamber 40 is provided in a cylinder head 30 that covers the top of the cylinder 20. An intake port 50 and an exhaust port 60 are formed so as to open to two inclined surfaces of the combustion chamber 40, the intake valve 70 opens and closes the tip of the intake port 50, and the tip of the exhaust port 60 is exhausted. The valve 80 is opened and closed. Here, the intake port 50 has a bifurcated tip portion, and a pair of intake valves 70 provided in each cylinder open and close the respective tips. Similarly, a pair of exhaust valves 80 are provided for each cylinder. A spark plug 90 is disposed in the center of the combustion chamber 40 surrounded by these four valves. Since the piston 10 disposed in the cylinder 20 is not a main part of the present invention, it is illustrated as a simple shape with a flat top surface. However, if necessary, the piston 10 has a desired shape suitable for stratified combustion or the like. May be configured.

  As shown in FIG. 1, in the present embodiment, a partition wall 200 is provided along the longitudinal direction of the intake port 50 so as to divide the intake port 50 into two upper and lower regions in its cross section. The partition wall 200 is configured, for example, by casting a separate metal plate when the cylinder head 30 is cast. The partition wall 200 is arranged so that the downstream end thereof is as close to the downstream side as possible, that is, as close to the intake valve 70 as possible.

  Here, as shown in FIG. 1, the intake port 50 is substantially linear in the longitudinal direction where the partition wall 200 is present, and the partition wall 200 is also substantially linear correspondingly. In the case where the intake port 50 is curved, the curved partition wall 200 is provided so as to follow the curved shape.

  As will be apparent to those skilled in the art, the terms “upper” and “lower” for the intake port 50 and the intake flow are based on the upper and lower sides of the cylinder 20 and mean absolute upper and lower in space is not. Further, the term “intake port” does not necessarily mean only a portion inside the cylinder head 30, but a part on the upstream side thereof is configured as another member outside the cylinder head 30, for example, a part of the intake manifold. This includes cases where In other words, a portion including an intake manifold or the like different from the cylinder head 30 is referred to as an “intake port”.

  In the portion where the partition wall 200 exists, the inside of the intake port 50 is divided into a lower passage portion, that is, a first flow path 51 and an upper passage portion, that is, a second flow path 52. An intake control valve 300 is provided for each cylinder so as to shield the lower first flow path 51 at the inlet side, that is, at the upstream end. The intake control valve 300 is provided on the extension line of the partition wall 200, particularly adjacent to the upstream end of the partition wall 200.

  The material of the partition wall 200 (all or a part thereof) is a shape memory alloy. The partition wall 200 includes a partition plate 210 whose shape is not changed regardless of temperature, and a lower end portion 220 whose shape changes depending on temperature. At least the material of the lower end 220 is a shape memory alloy.

  The lower end portion 220 warps to the arrow A (C) side in FIG. 1 when the temperature is low, and returns to the arrow A (H) side in FIG. 1 when the temperature is high. That is, the lower end portion 220 on the downstream side of the partition wall 200 (that is, the combustion chamber 40 side) is the arrow A (H) side when the temperature is high, and the second flow path 52 is not throttled. The second flow path 52 is narrowed on the side of the display A (C).

  The intake control valve 300 is configured by a flat plate that is supported at one end and rotates. The intake control valve 300 is connected to a rotation shaft 360, and the rotation shaft 360 is supported by a rotation shaft support portion 350 so that the intake control valve 300 can rotate. The rotation shaft 360 is connected to a rotation shaft of a motor controlled by an engine ECU (Electronic Control Unit), and the intake control valve 300 is rotated by the motor.

  Further, a storage portion 400 for storing the intake control valve 300 is provided in the lower first flow path 51.

  The motor rotates forward in accordance with a command from the engine ECU (the direction in which the intake control valve rotates clockwise in FIG. 1), and in the direction of arrow B (C), the tip of the intake control valve 300 and the partition wall 200 It rotates until it contacts the upstream end. This rotation is stopped by a stopper (not shown). The engine ECU simply outputs a rotation command signal to the motor for a predetermined time (at least the time for which the rotation shaft rotates about 45 °), and from the arrow B (H) side to the arrow B (C) side, the intake control valve 300 can be rotated.

  Further, the motor is reversely rotated by the command from the engine ECU (the direction in which the intake control valve rotates counterclockwise in FIG. 1), and the intake control valve 300 is accommodated in the storage portion 400 in the direction of arrow B (H). Rotate until retracted. This rotation is stopped by a stopper (not shown). The engine ECU only outputs a rotation command signal to the motor for a predetermined time (at least the time for which the rotating shaft rotates about 45 °), and from the arrow B (C) side to the arrow B (H) side, the intake control valve 300 can be rotated.

  Instead of the stopper or in addition to the stopper, the intake control valve 300 detects that the front end of the intake valve 300 is in contact with the upstream end of the partition wall 200 by a sensor, and the engine ECU issues a stop command to the motor. Alternatively, the engine ECU may detect that the intake control valve 300 is stored in the storage unit 400, and the engine ECU may output a stop command to the motor.

  As shown in FIG. 2, the intake control valve 300 realizes a fully open state as the first state (high temperature or warm). At this time, the intake control valve 300 is rotated in the direction of the arrow B (H) so as to be parallel to the wall surface of the intake port 50 and stored in the storage unit 400. For this reason, the lower first flow path 51 and the upper second flow path 52 are configured. In addition, since the lower end part 220 of the partition 200 is high temperature, it exists in the position of arrow A (H) side, and is the state which does not restrict | squeeze the 2nd flow path 52. FIG.

  As shown in FIG. 3, the intake control valve 300 realizes a half-open state as the second state (high temperature or warm). At this time, the intake control valve 300 is rotated in the direction of arrow B (C), the tip of the intake control valve 300 and the upstream end of the partition wall 200 abut, and the lower first flow The state where the path 51 is closed and the upper second flow path 52 is opened (that is, only the upper second flow path 52 is configured) is realized. Moreover, since the lower end part 220 of the partition 200 is high temperature, it exists in the position of arrow A (H) side, and is the state which does not restrict | squeeze the 2nd flow path 52. FIG.

  As shown in FIG. 4, the intake control valve 300 realizes a small open state as the third state (low temperature or cold). At this time, the intake control valve 300 is rotated in the direction of arrow B (C), the tip of the intake control valve 300 and the upstream end of the partition wall 200 abut, and the lower first flow The state where the path 51 is closed and the upper second flow path 52 is opened (that is, only the upper second flow path 52 is configured) is realized. Moreover, since the lower end part 220 of the partition 200 is low temperature, it exists in the position of arrow A (C) side, and is the state which restrict | squeezes the 2nd flow path 52. FIG.

  Next, the operation of the above configuration will be described. When the intake valve 70 is opened and the piston 100 is lowered during the intake stroke, the intake air flows into the cylinder 20 through the gap around the intake valve 70.

  At this time, as shown in FIG. 2, if the intake control valve 300 is in the open position (arrow B (H) side), the lower first flow path 51 (no throttling by the lower end portion 220) and the upper first Since a high flow rate of intake air flows through both of the two flow paths 52 and the intake air flows from each part around the intake valve 70 almost uniformly, the gas flow (tumble flow) generated in the cylinder 20 is relatively weak. At this time, the intake control valve 300 is housed in the housing portion 400 and does not become fluid resistance.

  As shown in FIG. 3, if the intake control valve 300 is in the half-open position, the tip of the intake control valve 300 and the upstream end of the partition wall 200 come into contact with each other, and the lower first flow path 51 is closed. . Intake flows only through the upper second flow path 52 (without restriction by the lower end 220). At this time, since the front end of the intake control valve 300 and the upstream end of the partition wall 200 are in contact with each other, the storage portion 400 does not become a fluid resistance.

  In this case, when the intake control valve 300 is controlled to the half-open position as shown in FIG. 3, the lower second flow path 52 is blocked, and the intake air flows to the cylinder 20 side only through the upper first flow path 51. . In particular, the intake flow is unevenly distributed along the upper inner wall surface of the intake port 50, and the flow along the lower inner wall surface of the intake port 50 is very small. Therefore, when the periphery of the intake valve 70 is viewed, in the gap on the lower side of the intake valve 70, that is, on the side close to the outer periphery of the cylinder 20, the flow rate of intake air is small and the flow velocity is low. In the gap close to 90, the flow rate of intake air is large and the flow velocity is high. As a result, a tumble flow (so-called forward tumble flow) is generated in the cylinder 20 from the intake valve 70 side to the top surface of the piston 100 through the exhaust valve 80 side, as indicated by the arrows in FIG.

  As shown in FIG. 4, if the intake control valve 300 is in the small open position, the tip of the intake control valve 300 and the upstream end of the partition wall 200 come into contact with each other, and the lower first flow path 51 is closed. It is done. The upper second flow path 52 warps upward due to the shape memory effect of the lower end portion 220, and the flow path cross-sectional area of the second flow path 52 is reduced. For this reason, intake air flows through only a part of the upper second flow path. At this time, since the front end of the intake control valve 300 and the upstream end of the partition wall 200 are in contact with each other, the storage portion 400 does not become a fluid resistance.

  In this case, when the intake control valve 300 is controlled to the small open position as shown in FIG. 4, the same effect as that when the intake control valve 300 is controlled to the half open position is produced. That is, the lower second flow path 52 is shielded, and the intake air flows to the cylinder 20 side only through a part of the upper first flow path 51. In particular, the intake flow is more unevenly distributed along the upper inner wall surface of the intake port 50 and the flow along the lower inner wall surface of the intake port 50 is further reduced than when the intake control valve 300 is in the half-open position. Therefore, when the periphery of the intake valve 70 is viewed, in the gap on the lower side of the intake valve 70, that is, on the side close to the outer periphery of the cylinder 20, the flow rate of intake air is small and the flow velocity is low. In the gap close to 90, the flow rate of intake air is large and the flow velocity is high. As a result, a tumble flow (so-called forward tumble) is generated in the cylinder 20 from the intake valve 70 side to the top surface of the piston 100 through the exhaust valve 80 side, as indicated by the arrows in FIG.

The engine operating states corresponding to these three states will be described.
When the throttle valve of the engine is in the fully open state (first operating state), the intake control valve 300 is in the fully open state that is the first state (the intake control valve 300 is in the direction indicated by the arrow B (H). The engine ECU controls the motor connected to the rotating shaft 360. Accordingly, the amount of air taken into the combustion chamber 40 of the engine can be increased and the output of the engine can be increased corresponding to WOT (Wide Open Throttle).

  When the engine temperature (often expressed by the engine coolant temperature) is low (third operating state), the intake control valve 300 is in the small open state, which is the third state ( The engine ECU controls the motor connected to the rotating shaft 360 so that the intake control valve 300 rotates in the direction of arrow B (C). At this time, due to the shape memory effect of the lower end portion 220 of the partition wall 200, the upper first flow path is narrowed by curving upward. Accordingly, the tumble flow generated in the cylinder 20 can be strengthened in response to the engine being in a cold state, the lean limit can be further reduced, and fuel efficiency can be improved. Can do. This is because the tumble flow causes the intake air to swirl along the axial direction of the cylinder, so the tumble flow collapses in the second half of the compression stroke and a strong turbulence is generated, improving combustion when the engine is cold This is considered to be caused by

  In the case of the engine state (second operating state) between the first operating state (WOT state) and the third operating state (cold state) described above, the intake control valve 300 is 3, the engine ECU controls the motor connected to the rotation shaft 360 so as to be in the same state as the small open state that is the state 3 (so that the intake control valve 300 rotates in the direction of arrow B (C)). At this time, the shape memory effect of the lower end portion 220 of the partition wall 200 does not act and the upper second flow path 52 is not restricted without warping upward. Thereby, in response to the engine being in a partial (intermediate) state, the tumble flow generated in the cylinder 20 can be strengthened, and further lean combustion can be realized by improving the combustion performance. Can be improved. This is because, similar to the third state described above, the tumble flow causes the intake air to swirl along the axial direction of the cylinder, so that the tumble flow collapses in the latter half of the compression stroke and a strong turbulent flow is generated. This is considered to be caused by improving combustion.

  As described above, the cross-sectional area of the intake passage is changed by the intake control valve that generates the tumble flow in the intake device in accordance with the operating state of the engine. In this case, the end portion on the downstream side of the partition wall was formed using a shape memory alloy having a shape memory action that warps at a low temperature. For this reason, the airflow in the cylinder can be enhanced without complicating the structure.

  Note that the length and inclination of the lower end portion 220 that shields the upper passage portion, that is, the second flow path 52 (determining the cross-sectional area of the second flow path 52) are required in order to improve fuel efficiency during cold weather. Is set according to the strength of the tumble flow.

  Further, in FIG. 1, an intake device having an inverted configuration may be used. In that case, the lower end portion 220 has a shape memory action that warps downward at a low temperature.

  Furthermore, the partition plate 210 and the airflow control valve 300 do not need to be in contact with each other so as to be in close contact with each other, and there may be a gap between these members as long as the effect of airflow control is exhibited.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is sectional drawing which shows the whole structure of the intake device which concerns on embodiment of this invention. It is a figure in case the intake device of FIG. 1 exists in a full open state. FIG. 2 is a view when the intake device of FIG. 1 is in a half-open state. It is a figure in case the intake device of FIG. 1 exists in a small open state.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Cylinder block, 20 Cylinder, 30 Cylinder head, 40 Combustion chamber, 50 Intake port, 51 1st flow path, 52 2nd flow path, 60 Exhaust port, 70 Intake valve, 80 Exhaust valve, 90 Spark plug, 100 Piston, 200 partition, 210 partition plate, 220 lower end, 300 airflow control valve, 350 rotating shaft support, 360 rotating shaft, 400 storage.

Claims (6)

An intake device for an internal combustion engine, wherein an intake port is connected to a cylinder of the internal combustion engine, and an intake valve opens and closes a tip on the downstream side of the intake port,
A partition wall provided along the longitudinal direction of the intake port so as to partition the intake port into a first flow path and a second flow path in its cross section;
An opening / closing mechanism that is provided in a pipe line that forms the intake port, and that opens and closes the first flow path;
A variable mechanism provided near the downstream end of the partition wall and changing a cross-sectional area of the second flow path;
An intake device for an internal combustion engine, wherein the first flow path and the second flow path are divided into two in the vertical direction, with the sliding direction of the piston in the cylinder as the vertical direction.   2. The intake device for an internal combustion engine according to claim 1, wherein the variable mechanism is made of a shape memory alloy and changes to a shape that restricts a cross-sectional area of the second flow path at a low temperature. The intake device is
A first state in which the first flow path is opened by the opening / closing mechanism and the second flow path is not throttled by the variable mechanism;
A second state in which the first flow path is closed by the opening and closing mechanism and the second flow path is not throttled by the variable mechanism;
3. The intake device for an internal combustion engine according to claim 2, wherein a third state in which the first flow path is closed by the opening / closing mechanism and the second flow path is throttled by the variable mechanism is realized.   The intake device for the internal combustion engine controls the switching between the first state, the second state, and the third state in accordance with three operation regions set in advance based on the operation state of the internal combustion engine. The intake device for an internal combustion engine according to claim 3, further comprising a unit. The control unit is
Controlling the opening and closing mechanism to be in the first state corresponding to the first operating region,
Controlling the opening and closing mechanism to be in the second state corresponding to the second operating region,
Controlling the opening and closing mechanism so as to be in the third state corresponding to the third operating region,
In the first operating region, the intake air amount is large, and in the third operating region, the temperature of the internal combustion engine is low,
The intake device for an internal combustion engine according to claim 4, wherein the state of the opening / closing mechanism in the second state is the same as the state of the opening / closing mechanism in the third state. The opening / closing mechanism has a rotation shaft that rotates the valve body around the position of the wall surface of the pipeline,
The valve body is composed of a flat plate provided with the central axis at a first end,
In the third state, when the variable mechanism formed of the shape memory alloy is deformed to a shape in a low temperature state, the second flow path is narrowed and reverse to the first end portion of the flat plate. A second end on the side is in contact with the partition wall and the first flow path is closed,
In the second state, the variable flow mechanism formed of the shape memory alloy does not deform into a low temperature state, so that the second flow path is not restricted, and the first end of the flat plate is The second end on the opposite side is in contact with the partition wall and is configured to close the first flow path,
In the first state, since the variable mechanism formed of the shape memory alloy does not deform into a low temperature state, the second flow path is not restricted and the flat plate is parallel to the wall surface of the pipe line. The intake device for an internal combustion engine according to claim 5, wherein the first flow path and the second flow path are configured.

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