JP6663522B2 - Partition plate - Google Patents

Description

  The present invention relates to a partition plate disposed inside an intake pipe.

  2. Description of the Related Art Conventionally, in order to generate a tumble (vertical vortex) flow in a combustion chamber, a partition partitioning an intake passage in an intake pipe into two intake passages (a first intake passage and a second intake passage). A plate is provided. When the load is low and the intake flow rate is low, the opening degree of, for example, the first intake passage partitioned by the partition plate is reduced by a TGV (Tumble Generation Valve), and the flow velocity of the intake air flowing into the combustion chamber from the second intake passage. , A strong tumble flow can be generated in the combustion chamber.

  In Patent Document 1, a stronger tumble flow is achieved by forming the cross-sectional shape of two intake ports separated from the intake manifold into a substantially isosceles triangle with the bottom surface facing the two intake ports. Can be generated effectively.

JP 2010-090849 A

  However, in the related art described in Patent Literature 1, the direction of the turning center axis of the generated tumble flow varies at a plurality of positions in a direction perpendicular to the direction from the intake side to the exhaust side in the combustion chamber. . Then, for example, a secondary flow (lateral vortex) in the swirl direction is generated in the compression stroke of the engine, which may cause a problem that the air-fuel mixture cannot be stably burned in the combustion stroke of the engine.

  Therefore, an object of the present invention is to provide a partition plate capable of effectively generating a tumble flow and improving the combustion stability of an engine.

  In order to solve the above problems, a partition plate as one aspect of the present invention includes a first intake passage that is opened and closed by a valve, an intake passage formed by an intake pipe connected to a combustion chamber, and A partition plate that is separated into a second intake passage and a shape of a first cross section orthogonal to an extending direction of the intake pipe; a shape of the combustion chamber and a shape of the second section of the intake pipe; It is determined based on the shape of the surface facing the intake passage.

  The shape of the first section is along a wall surface of the combustion chamber in a second section including a first direction which is an axial direction of a cylinder bore of the engine and a second direction from the intake side to the exhaust side of the combustion chamber. It may be determined based on the length in the circumferential direction.

となる式を満たしてもよい。 The shape of the first cross section is Lb (Yp, l), the shape of the surface of the intake pipe facing the second intake passage is Ip (Yp, l), and the axis of the cylinder bore of the engine is La (x, θ) is a circumferential length along a wall surface of the combustion chamber in a second section including a first direction which is a direction and a second direction from the intake side to the exhaust side of the combustion chamber. When a predetermined coefficient is a and b, an arbitrary position in the longitudinal direction in the first section is Yp, an arbitrary position in the extending direction is 1 and a crank angle of the engine is θ, The shape of the first section is

May be satisfied.

となる式を満たす。 In order to solve the above-mentioned problem, a partition plate as another aspect of the present invention includes a first intake passage that is opened and closed by a valve, an intake passage formed by an intake pipe connected to a combustion chamber, And a partition plate separated into a second intake passage and a first cross-sectional shape orthogonal to the extending direction of the intake pipe is Lb (Yp, l), and The shape of the surface facing the two intake passages is Ip (Yp, l), a predetermined coefficient is b, an arbitrary position in the longitudinal direction of the first section is Yp, When the arbitrary position is l, the shape of the first cross section is

Satisfies the following expression.

  ADVANTAGE OF THE INVENTION According to this invention, while producing a tumble flow effectively, the partition plate which can improve the combustion stability of an engine can be provided.

FIG. 2 is a schematic diagram illustrating a configuration of an engine. FIG. 2 is a schematic diagram illustrating a shape of a combustion chamber of the engine. FIG. 4 is a diagram for explaining a circumferential length La (x, θ) with respect to a position in the x direction of the combustion chamber. FIG. 2 is a schematic sectional view showing a section of the intake pipe. It is an outline sectional view showing a section of an intake pipe and a partition plate of this embodiment. It is an outline sectional view showing a section of an intake pipe and a partition plate of a modification.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values and the like shown in the embodiments are merely examples for facilitating the understanding of the present invention, and do not limit the present invention unless otherwise specified. In the specification and the drawings, elements having substantially the same function and configuration will be denoted by the same reference numerals, and redundant description will be omitted. Elements not directly related to the present invention will be omitted. I do.

  FIG. 1 is a schematic diagram illustrating a configuration of the engine 1. As shown in FIG. 1, the engine 1 includes a cylinder block 10, a crankcase 12 formed integrally with the cylinder block 10, and a cylinder head 14 connected to the cylinder block 10.

  A plurality of cylinder bores 16 are formed in the cylinder block 10, and a piston 18 is slidably supported by the connecting rod 20 in the cylinder bore 16. A space surrounded by the inner wall surface of the cylinder head 14, the inner wall surface of the cylinder bore 16, and the crown surface of the piston 18 is formed as a combustion chamber 22.

  A crankshaft 26 is rotatably supported in a crankcase 24 formed by the crankcase 12. The piston 18 is connected to the crankshaft 26 via a connecting rod 20. Thus, the piston 18 is connected to the crankshaft 26 via the connecting rod 20.

  An intake port 28 and an exhaust port 30 are formed in the cylinder head 14 so as to communicate with the combustion chamber 22. In the intake port 28, one opening is formed on the upstream side of the intake air, and two openings are formed on the downstream side of the intake air facing the combustion chamber 22, and the flow path branches into two on the way from the upstream to the downstream. I do. An umbrella portion of an intake valve 32 is located between the intake port 28 and the combustion chamber 22, and the intake valve 32 opens and closes the intake port 28 with respect to the combustion chamber 22 with rotation of a camshaft (not shown).

  An intake manifold 34 is connected to the upstream end 14a of the outer wall surface of the cylinder head 14 where the intake port 28 opens. An intake passage 36 through which intake air is guided is formed inside the intake manifold 34 and the intake port 28. Hereinafter, the intake manifold 34 and the intake port 28 that form the intake passage 36 are collectively referred to as an intake pipe 60.

  The exhaust port 30 has two openings formed on the upstream side of the exhaust gas facing the combustion chamber 22 and one opening formed on the downstream side of the exhaust gas. Is done. An umbrella portion of an exhaust valve 38 is located between the exhaust port 30 and the combustion chamber 22, and the exhaust valve 38 opens and closes the exhaust port 30 with respect to the combustion chamber 22 as a camshaft (not shown) rotates.

  An exhaust manifold 40 is connected to a downstream end 14b of the outer wall surface of the cylinder head 14 where the exhaust port 30 opens. Inside the exhaust port 30 and the exhaust manifold 40, an exhaust passage 42 through which exhaust is guided is formed. In the following, the exhaust manifold 40 and the exhaust port 30 forming the exhaust passage 42 are collectively referred to as an exhaust pipe 70.

  Further, the cylinder head 14 is provided with an injector 44 and a spark plug 46 such that the tip is located in the combustion chamber 22, and the injector 44 receives the intake air flowing into the combustion chamber 22 through the intake port 28 from the injector 44. Fuel is injected. Then, a mixture of the intake air and the fuel is ignited by a discharge of the ignition plug 46 at a predetermined timing and burns. Due to such combustion, the piston 18 reciprocates in the cylinder bore 16, and the reciprocation is converted into the rotational motion of the crankshaft 26 through the connecting rod 20.

  The intake passage 36 is provided with a partition plate 48 and a TGV 50 (Tumble Generation Valve). The partition plate 48 and the TGV 50 (valve) are provided between a throttle valve (not shown) and the combustion chamber 22. In the present embodiment, one end of the partition plate 48 is provided at a predetermined position inside the intake manifold 34, and the other end is provided at a position (upstream side) before the flow path inside the intake port 28 branches into two. Are located. However, the present embodiment is not limited to this, and may be arranged such that the other end extends to a position after the flow path inside the intake port 28 is branched (downstream side) into two. The partition plate 48 extends along the flow direction of the intake air (extending direction in which the intake pipe 60 extends) in the intake passage 36, and connects the intake passage 36 to the first intake passage 36 a and the second intake passage 36 a. It is divided (separated) into the intake passage 36b. The TGV 50 is arranged on the upstream side of the partition plate 48 and at a position facing the first intake passage 36a, and varies the opening degree of the first intake passage 36a.

  As shown in FIG. 1, when the opening of the TGV 50 is minimized and the TGV 50 closes one of the passages (here, the first intake passage 36a) partitioned into the partition plate 48, the intake passage 36 is closed. Is passed through the other flow path (here, the second intake flow path 36 b) divided by the partition plate 48 and is guided to the combustion chamber 22.

  In the engine 1, when the load is small and the intake flow rate is small, the opening of the TGV 50 is narrowed, and most of the intake air passes through the second intake passage 36 b divided by the partition wall plate 48. In this way, in the engine 1, by causing the air having the increased flow rate to flow into the combustion chamber 22, a strong tumble flow indicated by an arrow line in the drawing is generated in the combustion chamber 22. This allows the engine 1 to improve fuel economy by improving the limit of lean / dilution combustion of the fuel and to improve combustion stability by rapid combustion.

  However, the present embodiment is not limited to this, and the second intake passage 36b may be closed by the TGV 50, and the intake air may be introduced into the combustion chamber 22 via the first intake passage 36a. .

  FIG. 2 is a schematic diagram illustrating the shape of the combustion chamber 22. FIG. 2A is a schematic diagram schematically illustrating the shape of the combustion chamber 22. In FIG. 2A, the shape of the combustion chamber 22 is cylindrical for easy explanation. Further, directions orthogonal to each other and passing through the center point O on the upper surface of the combustion chamber 22 are represented by x direction, y direction, and z direction, respectively. Here, the direction from the intake side to the exhaust side in the cylinder head 14 (combustion chamber) is defined as the y direction (second direction), the axial direction of the cylinder bore 16 is defined as the z direction (first direction), and the y direction and the z direction are defined. An orthogonal direction is defined as an x direction.

  The tumble flow indicated by a white arrow in FIG. 2A that swirls in the yz cross section is converted into a tumble flow having the same swirl time and swirl center (hereinafter also referred to as a high-quality tumble flow) at a plurality of different positions on the x-axis. ), It is possible to suppress the tumble flow from turning in the xy plane direction (the direction perpendicular to the axial direction of the cylinder bore 16) in the compression stroke of the engine 1, for example. If it is possible to suppress the tumble flow from rotating in the xy plane direction in the compression stroke of the engine 1, it is possible to improve the combustion stability in the combustion stroke after the compression stroke. High lean combustion can be realized.

  In the present embodiment, in order to realize such a high-quality tumble flow, the shape of the partition plate 48 is determined based on the shape of the combustion chamber 22 and the shape of the intake pipe 60.

  Hereinafter, a method of determining the shape of the partition plate 48 will be described in detail.

  FIG. 2B is a diagram illustrating a cross-sectional shape a of the combustion chamber 22 at a position indicated by a broken line in FIG. FIG. 2C is a diagram illustrating a cross-sectional shape b of the combustion chamber 22 in a yz cross-section passing through the center point O, which is indicated by a dashed line in FIG.

…（１）

…（２）

…（３） In the present embodiment, both the cross-sectional shape a and the cross-sectional shape b are rectangular. Here, the circumferential length (circumferential length) La (x, θ) of the cross-sectional shape a and the cross-sectional shape b indicated by an arrow line in FIG. 2B and FIG. It is calculated by (3). Here, B is the cylinder bore diameter (cylinder inner diameter) of the engine 1, and H (θ) is the stroke amount that changes according to the crank angle θ of the engine 1. The crank angle θ is 0 ° when the piston 18 in the intake stroke is located at the top dead center.

… (1)

… (2)

… (3)

  FIG. 3 is a diagram for explaining the circumferential length La (x, θ) with respect to the position in the x direction. FIG. 3 shows the circumference La (x, θ) calculated by Expression (3) when, for example, the crank angle θ = 300 °. However, the crank angle θ used when calculating the stroke amount H (θ) in the equation (3) is not limited to this, and can be arbitrarily determined. When the circumference La (x, θ) is evaluated, it is desirable to evaluate the circumference before the intake valve is closed and compressed before the tumble flow collapses. Therefore, the crank angle θ is desirably set to 180 ° to 340 °. .

  As can be seen from Expression (3) and FIG. 3, the circumferential length La (x, θ) in the yz section (second section) of the combustion chamber 22 is x if the crank angle θ (stroke amount) is fixed. It changes according to the position in the direction. For example, comparing the cross-sectional shape a and the cross-sectional shape b in which the crank angle θ (stroke amount) is the same value in FIGS. 2B and 2C, the circumferential length La of the cross-sectional shape b (x = 0, θ ) Is larger than the circumference La (x> 0, θ) of the cross-sectional shape a. As shown in FIG. 3, the circumference La (x, θ) has a maximum value when x = 0.

  Therefore, in order to generate a high-quality tumble flow in the combustion chamber 22, it is necessary to consider the circumferential length La (x, θ) of the yz section of the combustion chamber 22. That is, if a tumble flow having a velocity (flow velocity) corresponding to the circumference La (x, θ) is generated, the swirling time and the swirling center of the tumble flow in each yz section in the combustion chamber 22 can be made uniform. .

  For example, the speed (first flow rate) of the tumble flow generated in the cross-sectional shape b is set to be faster than the speed (second flow rate) of the tumble flow generated in the cross-sectional shape a. The time required to make one round of the cross-sectional shape b and the time required to make one round of the cross-sectional shape a are the same. Then, the turning times and the turning centers of the tumble flows in the cross-sectional shapes a and b can be made uniform. Thus, by generating a tumble flow having a velocity (flow velocity) corresponding to the circumference La (x, θ), a tumble flow having a uniform turning time and a center of rotation, that is, a high-quality tumble flow is generated. Can be.

  FIG. 4 is a schematic sectional view showing a section of the intake pipe 60. FIG. 4 shows a cross-sectional shape of the intake pipe 60 in a cross section (first cross section) orthogonal to a direction extending along the intake flow path 36 of the intake pipe 60. In FIG. 4, in order to briefly describe the shape of the intake pipe 60, the cross-sectional shape of the intake pipe 60 is a rounded rectangular shape with rounded corners. In the present embodiment, the cross-sectional shape of the intake pipe 60 changes in a direction extending along the intake flow path 36 of the intake pipe 60. In FIG. 4, the longitudinal direction of the intake pipe 60 having a rounded rectangular shape is defined as the Y direction.

  Since the intake air flows along the intake pipe 60 before entering the combustion chamber 22, the shape of the intake pipe 60 also affects the formation of a high-quality tumble flow. For example, as described above, when the first intake passage 36a is closed by the TGV 50, the cross-sectional shape of the second intake passage 36b, that is, the intake pipe 60, in the second intake passage 36b. The flow velocity distribution of the intake air is formed in accordance with the shapes of the surfaces of the partition wall and the partition plate 48 facing each other. The distribution of the flow velocity of the intake air according to the shapes of the surfaces of the intake pipe 60 and the partition plate 48 facing each other is reflected in the tumble flow generated in the combustion chamber 22. Therefore, in forming a high-quality tumble flow, it is necessary to consider the shape of the surface of the intake pipe 60 facing the partition plate 48.

  As described above, the shape of the partition plate 48 for realizing a high-quality tumble flow includes the shape of the combustion chamber 22 (the above-described circumferential length La (x, θ) of the combustion chamber 22) and the shape of the intake pipe 60 (the above-described shape). And the shape of the surface of the intake pipe 60 facing the partition plate 48).

…（４） Specifically, the shape of the opposing surface of the partition plate 48 facing the intake pipe 60 with the second intake flow path 36b interposed therebetween in a cross section orthogonal to the direction in which the intake pipe 60 extends, that is, the shape Lb of the partition plate 48 (Yp, l) is calculated (determined) by the following equation (4). In the following equation (4), Lb (Yp, l) is calculated from the facing surface (inner surface, bottom surface) of the intake pipe 60 facing the partition plate 48 with the second intake passage 36b interposed therebetween. It represents the distance to the opposing surface of the partition plate 48 that faces the intake pipe 60 across 36b.

… (4)

  Here, Ip (Yp, l) is the shape 60b of the opposed surface (inner surface, bottom surface) of the intake pipe 60 facing the partition plate 48 with the second intake passage 36b interposed therebetween. a is a coefficient determined by the tumble ratio, the shape of the intake valve 32, and the like, and b is a coefficient for determining the opening area of the second intake passage 36b. Yp is an arbitrary position in the longitudinal direction of the partition plate 48 (or the intake pipe 60) in a cross section orthogonal to the extending direction (hereinafter, simply referred to as the extending direction) in which the intake pipe 60 extends. Is an arbitrary position in the extending direction, and θ is a crank angle of the engine 1. The coefficient a and the coefficient b are values (coefficients) obtained by an empirical formula.

  FIG. 5 is a schematic sectional view showing a section of the intake pipe 60 and the partition plate 48. FIG. 5 shows the shape Lb (Yp, l) of the partition plate 48 calculated by the equation (4). As shown in FIG. 5, the shape of the partition plate 48 in a cross section orthogonal to the extending direction has a curved shape.

  As can be seen from Equation (4), the shape Lb (Yp, l) of the partition plate 48 is the circumference La (x, θ) of the combustion chamber 22 and the shape 60b (Ip (Yp, l)) of the intake pipe 60. Is determined based on

  By determining the shape Lb (Yp, l) of the partition plate 48 based on the shape 60b (Ip (Yp, l)) of the intake pipe 60, the distance between the intake pipe 60 (shape 60b) and the partition plate 48 is reduced. The flow rate distribution of the intake air flowing in the second intake passage 36b can be made uniform (aligned) in the Y direction.

  Further, by determining the shape Lb (Yp, l) of the partition plate 48 based on the circumference La (x, θ) of the combustion chamber 22, each circumference La (x, θ) of the combustion chamber 22 in the x direction is determined. ) Can be generated, and a high-quality tumble flow having a uniform swirling time and swirling center in the combustion chamber 22 can be generated.

  Therefore, according to the present embodiment, by determining the shape Lb (Yp, l) of the partition plate 48 that satisfies the expression (4), the tumble flow is effectively generated, and the combustion stability of the engine 1 is improved. A partition plate 48 that can be provided can be provided.

(Modification)
In the above description, the shape Lb (Yp, 1) of the partition plate 48 is calculated on the assumption that the intake air flows along the wall surface of the combustion chamber 22 (a tumble flow is generated). However, actually, the intake air does not always flow along the wall surface of the combustion chamber 22, and may form a tumble flow away from the wall surface of the combustion chamber 22.

  Therefore, in the present modification, the shape Lb (Yp, l) of the partition plate 48 is calculated (determined) on the assumption that a tumble flow is generated away from the wall surface of the combustion chamber 22.

  In this case, by making the speed of the tumble flow generated in the plane of the cross-sectional shape a and the cross-sectional shape b in FIGS. 2B and 2C the same, the turning time and the turning center are high quality. A tumble flow can be generated.

…（５） Specifically, the shape Lb (Yp, l) of the partition plate 48 is calculated (determined) by the following equation (5).

… (5)

  FIG. 6 is a schematic cross-sectional view showing a cross section of the intake pipe 60 and the partition plate 48 in the present modification. FIG. 6 shows the shape Lb (Yp, l) of the partition plate 48 calculated by the equation (5). As shown in FIG. 6, the shape of the partition plate 48 in a cross section orthogonal to the extending direction in which the intake pipe 60 extends has a curved shape.

  As can be seen from Expression (5), the shape Lb (Yp, l) of the partition plate 48 is the shape 60b (Ip (Yp, Ip, Yp) of the surface of the intake pipe 60 that faces the partition plate 48 in the second intake passage 36b. 1)).

  By determining the shape Lb (Yp, l) of the partition plate 48 based on the shape 60b (Ip (Yp, l)) of the intake pipe 60, the distance between the intake pipe 60 (shape 60b) and the partition plate 48 is reduced. The flow rate distribution of the intake air flowing in the second intake passage 36b can be made uniform (aligned) in the Y direction.

  Therefore, by determining the shape Lb (Yp, l) of the partition plate 48 that satisfies the equation (5), the velocity of the tumble flow can be made the same in the yz section of the combustion chamber 22, and the swirling time and the swirling center can be reduced. A uniform high-quality tumble flow can be generated.

  Therefore, according to the present modification, by determining the shape Lb (Yp, l) of the partition plate 48 that satisfies the expression (5), the tumble flow is effectively generated, and the combustion stability of the engine 1 is improved. A partition plate 48 that can be provided can be provided.

  As described above, the preferred embodiments of the present invention have been described with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such embodiments. It is obvious to those skilled in the art that various changes or modifications can be conceived within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present invention. Is done.

  For example, the shape of the partition plate 48 between FIGS. 5 and 6 (intermediate) may be obtained by performing an interpolation process on the shape of the partition plate 48 of FIGS.

  Further, in the above description, the case where the first intake passage 36a is closed has been described. On the contrary, the tumble flow is caused by the intake that closes the second intake passage 36b and passes through the first intake passage 36a. May be generated. In that case, the shape Lb (Yp, l) of the partition plate 48 is determined based on the shape 60a of the surface of the intake pipe 60 that faces the partition plate 48 with the first intake passage 36a interposed therebetween.

  INDUSTRIAL APPLICATION This invention can be utilized for the partition plate arrange | positioned inside an intake pipe.

22 Combustion chamber 36 Intake passage 36a First intake passage 36b Second intake passage 50 TGV (valve)
48 Partition plate 60 Intake pipe

Claims (4)

A partition plate for separating an intake passage formed by an intake pipe connected to a combustion chamber into a first intake passage opened and closed by a valve and a second intake passage,
The shape of the first cross section orthogonal to the direction in which the intake pipe extends is determined based on the shape of the combustion chamber and the shape of the surface of the intake pipe that faces the second intake passage. Septum plate.   The shape of the first section is along a wall surface of the combustion chamber in a second section including a first direction which is an axial direction of a cylinder bore of the engine and a second direction from the intake side to the exhaust side of the combustion chamber. The partition plate according to claim 1, wherein the partition plate is determined based on the circumferential length. The shape of the first cross section is Lb (Yp, l), the shape of the surface of the intake pipe facing the second intake passage is Ip (Yp, l), and the axis of the cylinder bore of the engine is La (x, θ) is a circumferential length along a wall surface of the combustion chamber in a second section including a first direction that is a direction and a second direction from the intake side to the exhaust side of the combustion chamber. When a predetermined coefficient is a and b, an arbitrary position in the longitudinal direction in the first cross section is Yp, an arbitrary position in the extending direction is 1 and a crank angle of the engine is θ,
The shape of the first cross section is

The partition plate according to claim 1 or 2, wherein the following formula is satisfied. A partition plate for separating an intake passage formed by an intake pipe connected to a combustion chamber into a first intake passage opened and closed by a valve and a second intake passage,
The shape of the first cross section orthogonal to the extending direction of the intake pipe is Lb (Yp, l), and the shape of the surface of the intake pipe facing the second intake flow path is Ip (Yp, Yp, Ip). l), a predetermined coefficient is b, an arbitrary position in the longitudinal direction of the first cross section is Yp, and an arbitrary position in the extending direction is l.
The shape of the first cross section is

A partition plate that satisfies the formula:

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