JP4581801B2 - Internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine having an intake passage and an exhaust passage.

  The internal combustion engine is provided with an intake passage for introducing fresh air and mixing it with fuel to form an air-fuel mixture. This intake passage is constituted by intake system members such as an intake manifold and a throttle body, and these intake system members are fixed so as to be connected to an intake port provided in the internal combustion engine. Similarly, the internal combustion engine is provided with an exhaust passage for exhausting exhaust gas after combustion. The exhaust passage is constituted by an exhaust system member such as an exhaust manifold, and these exhaust system members are fixed so as to be connected to an exhaust port provided in the internal combustion engine.

  When the intake system member and the exhaust system member are fixed and connected to the internal combustion engine in this way, the center of gravity of the intake system member or the exhaust system member is separated to the outside of the connection portion between the intake system member or the exhaust system member and the internal combustion engine. Are often located. As a result, a moment acts in addition to the shear stress at the connection portion between the intake system member or the exhaust system member and the internal combustion engine, which may affect the durability of the connection portion.

  On the other hand, in recent years, a technique for making the compression ratio of an internal combustion engine variable has been proposed for the purpose of improving the fuel efficiency performance and output performance of the internal combustion engine. As this type of technology, the cylinder block and the crankcase are connected so as to be relatively movable, and a camshaft is provided at the connecting portion, and the camshaft is rotated to connect the cylinder block and the crankcase in the axial direction of the cylinder. A variable compression ratio internal combustion engine has been proposed in which the volume of the combustion chamber is changed by relative movement to the internal combustion engine, thereby changing the compression ratio of the internal combustion engine (see, for example, Patent Document 1).

In such a variable compression ratio internal combustion engine, since the cylinder block and the crankcase move relative to each other, the place where the intake system member or exhaust system member is fixed to the internal combustion engine is limited, and the moment acting on the connecting portion is reduced. There were cases where it was particularly difficult to do.
JP 2003-206871 A Japanese Utility Model Publication No. 63-86366 JP-A-11-141406 Japanese Patent Laid-Open No. 11-50924

  The present invention has been made in view of the above prior art, and an object of the present invention is to reduce the moment acting on the connection portion of the intake system member or the exhaust system member with respect to the internal combustion engine, and to improve the durability at the connection portion. It is to provide technology that improves the performance.

  In order to achieve the above object, the present invention is configured by connecting an intake system member and an exhaust system member connected and fixed to an internal combustion engine by a connecting member, and configured by the intake system member, the exhaust system member, and the connecting member. The center of gravity of the intake / exhaust system member is between a vertical line passing through a connection portion between the intake system member and the internal combustion engine and a vertical line passing through a connection portion between the exhaust system member and the internal combustion engine. The greatest feature is that it is configured to be positioned.

More specifically, an intake system member that forms a part of the intake passage of the internal combustion engine by being fixed and connected to the internal combustion engine at an intake system connection portion;
An exhaust system member that forms a part of an exhaust passage of the internal combustion engine by being fixed and connected to the internal combustion engine at an exhaust system connection portion;
A coupling member that regulates a change in relative position of each other by coupling the intake system member and the exhaust system member;
The horizontal position of the center of gravity of the intake / exhaust system member constituted by the intake system member, the exhaust system member, and the connecting member passes through the vertical line passing through the intake system connection portion and the exhaust system connection portion. It is characterized by being located between the vertical line.

  Here, as described above, the internal combustion engine is provided with an intake passage for introducing fresh air into the internal combustion engine and an exhaust passage for discharging exhaust gas after combustion from the internal combustion engine. These intake passages and exhaust passages form long pipelines. Therefore, in order to fix the intake passage and the exhaust passage with sufficient reliability with respect to the internal combustion engine, these pipe lines are also disposed at other locations of the connection portion between the pipe lines and the internal combustion engine. It is desirable to fix the internal combustion engine or a place where it does not move relative to the internal combustion engine.

  However, depending on the configuration of the internal combustion engine, the intake system member or the exhaust system member itself that forms at least a part of the intake passage or the exhaust passage may be moved to a place where it does not move relative to the internal combustion engine or the internal combustion engine. In some cases, it was difficult to fix at multiple locations.

  Here, in a state where the intake system member and the exhaust system member are fixed to the internal combustion engine only in the intake system connection portion and the exhaust system connection portion, respectively, the intake system connection portion and the exhaust system are respectively connected to the internal combustion engine. A moment according to the weight of the intake system member and the exhaust system member and the position of the center of gravity acts on the connection portion. This moment increases as the weight of the intake system member and the exhaust system member increases, and the position of the center of gravity of the exhaust system member increases as the position of the center of gravity of the intake system member increases from the intake system connection portion. The distance from the exhaust system connection increases.

  In addition, here, the intake system member and the exhaust system member often include a tubular member that forms a long pipe line as described above, and the center of gravity of the intake system member and the exhaust system member is very small between the intake system connection portion and the exhaust system connection portion. It may be difficult to configure to be close.

  Therefore, in such a case, every time vibration or impact occurs during the operation of the internal combustion engine, the intake system connection portion and the exhaust system connection portion are subjected to inertia of the intake system member and the exhaust system member. The base moment acts. This may reduce the durability of the intake system connection or the exhaust system connection in the internal combustion engine.

  Therefore, in the present invention, the intake system member and the exhaust system member are connected by a connecting member, and the horizontal position of the center of gravity of the entire intake / exhaust system member combining these members is the intake system connection portion. And a vertical line passing through the exhaust system connection portion.

  Then, the place where the inertial force, which is the basis of the moment acting on the intake system connection part or the exhaust system connection part, is prevented from being excessively distant from the intake system connection part or the exhaust system connection part. can do. As a result, it is possible to suppress an excessive moment acting on the intake system connection portion or the exhaust system connection portion, and to improve durability in the intake system connection portion or the exhaust system connection portion of the internal combustion engine. it can.

Here, the intake system member and the exhaust system member are members that are connected and fixed to the internal combustion engine, and a moment according to the weight and the position of the center of gravity directly acts on the intake system connection unit and the exhaust system connection unit. means. For example, when the throttle body is integrally incorporated in the intake manifold, the exhaust manifold, or the intake manifold, an intake manifold unit in which the throttle body is added to the intake manifold can be cited. Further, an intake system module in which a cylinder head cover, an air cleaner case and the like other than the throttle body are integrally formed on the intake manifold can be exemplified. Further, examples include a member including an exhaust pipe and an exhaust purification device connected to the exhaust manifold without a flexible member, and a member including an intake pipe connected to the intake manifold without a flexible member. can do.

Further, in the present invention, a cylinder block in which a cylinder in the internal combustion engine is formed,
A crankcase in which the crankshaft in the internal combustion engine is assembled and the cylinder block is attached to be relatively movable;
You may make it further provide the compression ratio change means which changes the compression ratio of the said internal combustion engine by making the said crankcase and the said cylinder block approach or leave | separate relatively.

  That is, as described above, the intake system member and the exhaust system member are connected by a connecting member, and the horizontal position of the center of gravity of the entire intake / exhaust system member combining these members is the intake system connection portion. A variable compression ratio internal combustion engine that changes the compression ratio by moving the crankcase and the cylinder block relative to each other so as to be between the vertical line passing through the exhaust system and the vertical line passing through the exhaust system connection portion You may apply to.

  Here, in the variable compression ratio internal combustion engine, the crankcase and the cylinder block relatively move as described above.

  In this case, since it becomes difficult to support the intake system member and the exhaust system member on both the cylinder block side and the crankcase side, the intake system member and the exhaust system member are connected to the intake system connection portion and the exhaust system. It is more difficult to fix effectively at a plurality of locations including the system connection than in a normal internal combustion engine that is not a variable compression ratio internal combustion engine.

  Further, in the variable compression ratio internal combustion engine as described above, when the intake system connection portion and the exhaust system connection portion are arranged on the side of the cylinder block and the crankcase that move when changing the compression ratio. In addition, a moment based on the inertia force of the intake system member and the exhaust system member during the movement also acts on the intake system connection part and the exhaust system connection part.

  From these, the intake system member and the exhaust system member are connected by a connecting member, and the horizontal position of the center of gravity of the intake / exhaust system member as a whole combining these members is a vertical position that passes through the intake system connection portion. When the configuration that is between the line and the vertical line passing through the exhaust system connection portion is applied to the variable compression ratio internal combustion engine as described above, more effectively, the internal combustion engine The durability in the intake system connection part and the exhaust system connection part can be improved.

Further, in the present invention, a cylinder block in which a cylinder in the internal combustion engine is formed,
A cylinder head attached to the cylinder block and provided with a valve mechanism for the internal combustion engine;
The connecting member may connect the intake system member and the exhaust system member by passing through a space opposite to the cylinder block with respect to the cylinder head.

With such a configuration, the intake system member and the exhaust system member can be coupled by the coupling member at a position separated in the axial direction of the cylinder. This way
As the whole intake / exhaust system member, the axial width of the cylinder can be increased, and its rigidity can be increased. Further, since the space opposite to the cylinder block with respect to the cylinder head is relatively easy to secure, the space utilization efficiency can be increased.

  In the present invention, the intake system connection portion and the exhaust system connection portion may be provided on the cylinder block or a member that does not move relative to the cylinder block.

  Then, the intake system member and the exhaust system member can be fixed and connected to a member that does not move relative to the cylinder of the internal combustion engine, and the combustion chamber, the intake system, and the exhaust system in the internal combustion engine. Can be configured more simply.

  Here, examples of the member that does not move relative to the cylinder block include a cylinder head attached to the cylinder block, and a pipe relayed at an opening of an intake port or an exhaust port of the cylinder head. be able to.

  In the present invention, the intake / exhaust system member may be further fixed to the internal combustion engine at a place other than the intake system connection part and the exhaust system connection part.

  That is, the intake / exhaust system member may be fixed to the internal combustion engine at one or more locations other than the intake system connection and the exhaust system connection. By doing so, the intake / exhaust system member can be fixed to the internal combustion engine at three or more locations, so that the entire intake / exhaust system member can be more securely fixed to the internal combustion engine. As a result, a moment acting on the intake system connection portion and the exhaust system connection portion can be suppressed, and durability in the intake system connection portion and the exhaust system connection portion of the internal combustion engine can be improved.

  Here, when the internal combustion engine is a variable compression ratio internal combustion engine that changes the compression ratio by relatively approaching or separating the crankcase and the cylinder block, the intake and exhaust system members include the crankcase and It is desirable that the cylinder block is further fixed to the side where the intake system connection portion and the exhaust system connection portion are provided. As a result, even when the crankcase and the cylinder block relatively move when the compression ratio is changed, the entire intake / exhaust system member can be more securely fixed to the internal combustion engine.

  Further, when the intake / exhaust system member is further fixed to the internal combustion engine, it may be fixed via an elastic body. This makes it difficult to transmit the pulsating noise of the gas generated in the intake passage or the exhaust passage to the internal combustion engine.

  Further, in the present invention, the intake system member and / or the exhaust system is coupled to the cylinder block or the member that does not move relative to the cylinder block, and the intake system member and / or the exhaust system member. You may make it further provide the auxiliary member which assists fixation with respect to the said internal combustion engine of a system member.

  That is, the intake system member and / or the exhaust system member may be further fixed to the cylinder block or a member that does not move relative to the cylinder block by an auxiliary member that is a separate part. In this case, the intake system member and / or the exhaust system member can be more reliably fixed at the intake system connection portion and / or the exhaust system connection portion.

Further, in the present invention, a crankcase in which a crankshaft in an internal combustion engine is assembled,
A cylinder block in which a cylinder in the internal combustion engine is formed and attached so as to be relatively movable with respect to the crankcase;
An internal combustion engine comprising compression ratio changing means for changing the compression ratio of the internal combustion engine by moving the crankcase and the cylinder block relatively close to or away from each other;
One or a plurality of cylinder block side members that are fixed at a location that does not move relative to the cylinder block and that are used for operation of the internal combustion engine or engine-related parts;
An auxiliary member that assists in fixing the cylinder block side member to the internal combustion engine by connecting the cylinder block side member and a place that does not move relative to the cylinder block;
You may make it provide.

  Here, in the variable compression ratio internal combustion engine in which the compression ratio is changed by moving the crankcase and the cylinder block relative to each other, various components such as an intake system member and an exhaust system member are connected to the cylinder block. (Hereinafter, these are referred to as “cylinder block side members”). In this case, as described above, since the distance between the crankcase and the cylinder block changes, the cylinder block side member is fixed by being connected to the crankcase or a place that does not move relative to the crankcase. Then, when the above-described compression ratio is changed, an excessive load is applied to the cylinder block side member, and the above-described change in the compression ratio may be hindered.

  Therefore, in the present invention, the cylinder block side member and a place that does not move relative to the cylinder block are connected and supported by the auxiliary member. Then, the cylinder block side member is connected and supported by the auxiliary member at a place where it does not move relative to the cylinder flock side member itself, so that the cylinder block side member moves relative to the cylinder block. It is possible to more securely fix the place not to be used. In addition, the compression ratio can be controlled more reliably.

  Here, examples of the cylinder block side member include intake / exhaust system members, auxiliary machines such as a starter motor and a generator, power supply related parts, sensors, and control boards. Examples of places where the cylinder block does not move relative to the cylinder block include the cylinder block itself, a cylinder head, and a cylinder head cover.

The present invention further includes a cylinder head attached to the cylinder block and provided with a valve mechanism for the internal combustion engine,
The cylinder block side member is fixed and connected to the cylinder head to thereby form an intake system member that forms a part of the intake passage of the internal combustion engine, or the cylinder block side member is fixed to and connected to the cylinder head. An exhaust system member that forms part of the exhaust passage of the engine;
The auxiliary member is fixed to each of the cylinder block, the cylinder head, and the intake system member or the exhaust system member, so that the cylinder block side member and a place where the auxiliary member does not move relative to the cylinder block, May be connected.

That is, the cylinder block that moves relative to the crankcase is provided with a cylinder head, and an intake system member and / or an exhaust system member as the cylinder block side member is connected to the cylinder head, and the internal combustion engine An intake passage and / or an exhaust passage, and the auxiliary member, the cylinder block, the cylinder head, and the intake system member or the exhaust system member. After being fixed and supported at a total of three or more points, the cylinder block side member may be connected to a place that does not move relative to the cylinder block.

  By doing so, the fixing of the intake system member and / or the exhaust system member can be assisted at three or more points separated by the auxiliary member, so that the cylinder head of the intake system member and / or the exhaust system member Can be more reliably fixed, and the rigidity of the auxiliary member itself can be ensured.

  The means for solving the above-described problems of the present invention can be used in combination as much as possible.

  In the present invention, the moment acting on the connection portion of the intake system member or the exhaust system member with respect to the internal combustion engine can be reduced, and the durability at the connection portion can be improved.

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings.

  The internal combustion engine 1 described below is a variable compression ratio internal combustion engine, and is compressed by moving a cylinder block 3 having a cylinder 2 in the direction of the center axis of the cylinder 2 with respect to a crankcase 4 to which a piston 16 is connected. The ratio is changed.

  First, the configuration of a variable compression ratio internal combustion engine according to this embodiment will be described with reference to FIG. As shown in FIG. 1, a plurality of raised portions are formed at the lower portions on both sides of the cylinder block 3, and bearing housing holes 5 are formed in the raised portions. The bearing housing hole 5 has a circular shape, and is formed so as to be perpendicular to the axial direction of the cylinder 2 and parallel to the arrangement direction of the plurality of cylinders 2. The bearing housing holes 5 are all located on the same axis. The pair of axes of the bearing housing holes 5 on both sides of the cylinder block 3 are parallel.

  The crankcase 4 is formed with a standing wall portion so as to be positioned between the plurality of raised portions in which the bearing housing holes 5 described above are formed. A semicircular recess is formed on the surface of each standing wall portion facing the outside of the crankcase 4. Moreover, the cap 7 attached with the volt | bolt 6 is prepared for each standing wall part, and the cap 7 also has a semicircle recessed part. Further, when the cap 7 is attached to each standing wall portion, a circular cam housing hole 8 is formed. The shape of the cam storage hole 8 is the same as that of the bearing storage hole 5 described above.

  Similar to the bearing housing hole 5, the plurality of cam housing holes 8 are perpendicular to the axial direction of the cylinder 2 when the cylinder block 3 is attached to the crankcase 4 and parallel to the arrangement direction of the plurality of cylinders 2. Each is formed to be. The plurality of cam storage holes 8 are also formed on both sides of the cylinder block 3, and the plurality of cam storage holes 8 on one side are all located on the same axis. The pair of axes of the cam storage holes 8 on both sides of the cylinder block 3 are parallel. Further, the distance between the bearing housing holes 5 on both sides and the distance between the cam housing holes 8 on both sides are the same.

Cam shafts 9 are inserted through the two rows of bearing housing holes 5 and cam housing holes 8 arranged alternately. As shown in FIG. 1, the cam shaft 9 includes a shaft portion 9a and a cam portion 9b having a right circular cam profile fixed to the shaft portion 9a in a state of being eccentric with respect to the central axis of the shaft portion 9a. The movable bearing portions 9c having the same outer shape as the cam portions 9b and rotatably attached to the shaft portions 9a are alternately arranged. The pair of cam shafts 9 have a mirror image relationship. Further, a mounting portion 9d of a gear 10 to be described later is formed at the end of the cam shaft 9. The center axis of the shaft portion 9a and the center of the attachment portion 9d are eccentric, and the center of the cam portion 9b and the center of the attachment portion 9d coincide.

  The movable bearing portion 9c is also eccentric with respect to the shaft portion 9a, and the amount of eccentricity is the same as that of the cam portion 9b. In each camshaft 9, the eccentric directions of the plurality of cam portions 9b are the same. Since the outer shape of the movable bearing portion 9c is a perfect circle having the same diameter as the cam portion 9b, the outer surface of the plurality of cam portions 9b and the outer surfaces of the plurality of movable bearing portions 9c are rotated by rotating the movable bearing portion 9c. Can be matched with the side.

  A gear 10 is attached to one end of each camshaft 9. Worm gears 11a and 11b are engaged with the pair of gears 10 fixed to the ends of the pair of cam shafts 9, respectively. The worm gears 11 a and 11 b are attached to one output shaft of the single motor 12. The worm gears 11a and 11b have spiral grooves that rotate in opposite directions. For this reason, when the motor 12 is rotated, the pair of cam shafts 9 rotate in opposite directions via the gear 10. The motor 12 is fixed to the cylinder block 3 and moves integrally with the cylinder block 3.

  Next, a method for controlling the compression ratio in the internal combustion engine 1 having the above-described configuration will be described in detail. 2 (a) to 2 (c) are cross-sectional views showing the relationship between the cylinder block 3, the crankcase 4, and the cam shaft 9 constructed between them. 2A to 2C, the central axis of the shaft portion 9a is indicated by a, the center of the cam portion 9b is indicated by b, and the center of the movable bearing portion 9c is indicated by c. FIG. 2A shows a state in which the outer peripheries of all the cam portions 9b and the movable bearing portion 9c coincide with each other when viewed from the extension line of the shaft portion 9a. At this time, here, the pair of shaft portions 9 a are located outside the bearing housing hole 5 and the cam housing hole 8.

  When the motor 12 is driven from the state of FIG. 2A and rotated in the direction of the arrow of the shaft portion 9a, the state of FIG. 2B is obtained. At this time, since the cam portion 9b and the movable bearing portion 9c are displaced in the eccentric direction with respect to the shaft portion 9a, the cylinder block 3 can be slid to the top dead center side with respect to the crankcase 4. The sliding amount is maximized when the cam shaft 9 is rotated until the state shown in FIG. 2C is reached, and is twice the eccentric amount of the cam portion 9b and the movable bearing portion 9c. The cam portion 9b and the movable bearing portion 9c rotate inside the cam storage hole 8 and the bearing storage hole 5, respectively, and allow the position of the shaft portion 9a to move inside the cam storage hole 8 and the bearing storage hole 5, respectively. is doing.

  By using the mechanism as described above, the cylinder block 3 can be moved relative to the crankcase 4 in the axial direction of the cylinder 2, and the compression ratio can be variably controlled.

  Next, details of the above-described internal combustion engine 1 will be described. FIG. 3 is a diagram showing details including a part of the intake and exhaust system members of the internal combustion engine 1. In FIG. 3, a valve mechanism including an intake / exhaust valve (not shown) and a cylinder head 15 having an intake / exhaust port are attached to the upper portion of the cylinder block 3. A cylinder head cover 16 that protects the valve operating mechanism and the like is attached to the upper part of the cylinder head 15.

  An intake manifold unit 17 is attached to the cylinder head 15. The intake manifold unit 17 includes an intake manifold 17a and a throttle body 17b, and a downstream end portion of the intake manifold 17a is connected to an unillustrated intake port at a first connection portion 17c.

  On the other hand, an exhaust manifold 18 for allowing the exhaust discharged from the internal combustion engine 1 to pass through is attached to the cylinder head 15. The exhaust manifold 18 has an upstream end connected to an exhaust port (not shown) of the cylinder head 15 at the second connection portion 18a.

  Here, the first connection portion 17c corresponds to an intake system connection portion, and the second connection portion 18a corresponds to an exhaust system connection portion. The intake manifold unit 17 corresponds to an intake system member, and the exhaust manifold corresponds to an exhaust system member.

  Further, an exhaust pipe 20 is connected to a downstream end of the exhaust manifold 18 through a flexible pipe 19 that is formed of a flexible material and allows passage of exhaust gas. The exhaust pipe 20 is fixed to the crankcase 4 by an exhaust pipe stay 21. In the internal combustion engine 1 in this embodiment, the exhaust pipe 20 is directly connected to the exhaust manifold 18 because the cylinder block 3 and the cylinder head 15 move relative to the crankcase 4 in order to change the compression ratio. Therefore, when the compression ratio is changed, the relative movement of the cylinder block 3 and the cylinder head 15 with respect to the crankcase 4 may be hindered, or an excessive load may be applied to the exhaust manifold 18 or the exhaust pipe 20. By disposing 19, the exhaust manifold 18 and the exhaust pipe 20 can be moved relative to each other.

  Similarly, although omitted in FIG. 3, an intake pipe is connected to the connection port 22 in the intake manifold unit 17 via a flexible pipe.

  Further, G1 and G2 in FIG. 3 indicate the positions of the center of gravity in the intake manifold unit 17 and the exhaust manifold 18. Here, the center of gravity G1 of the intake manifold unit 17 and the center of gravity G2 of the exhaust manifold 18 are present at locations far away from the first connection portion 17c and the second connection portion 18a.

  Then, when the cylinder block 15 is moved for changing the compression ratio of the internal combustion engine 1 or when the vehicle equipped with the internal combustion engine 1 is traveling, vibrations or impacts are generated, and the flexibility is ensured by the flexible pipe 19. Even if it is, the moment based on the inertia of the intake manifold unit 17 and the exhaust manifold 18 acts on the first connection portion 17c and the second connection portion 18a.

  Then, the magnitude of the moment at that time increases as the position of the center of gravity G1 of the intake manifold unit 17 becomes farther from the first connection portion 17c, and the position of the center of gravity G2 of the exhaust manifold 18 changes to the second connection portion 18a. The bigger you are, the bigger you are. When the moment acting on the first connection portion 17c and the second connection portion 18a is large, the durability of the internal combustion engine 1 at the first connection portion 17c and the second connection portion 18a may be reduced.

  Therefore, in this embodiment, the intake manifold unit 17 and the exhaust manifold 18 are bridged by the stay 23. Specifically, the stay 23 is passed over the cylinder head cover 16, the intake manifold unit 17 and the stay 23 are coupled to each other at the intake side boss 23a, and the exhaust manifold 18 and the stay 23 are coupled to each other at the exhaust boss 23b. .

The center of gravity G3 of the intake manifold unit 17, the exhaust manifold 18, and the stay 23 is positioned between the first connection portion 17c and the second connection portion 18a. In this case, the stay 23 is lighter in weight than the intake manifold unit 17 and the exhaust manifold 18, so the intake manifold unit 17, the exhaust manifold 18, and the stay 23.
The position of the entire center of gravity G3 in the vertical direction is located on the straight line connecting G1 and G2 or slightly above the straight line.

  Then, the intake manifold unit 17, the exhaust manifold 18 and the stay 23 are improved in rigidity, and are supported at the two points of the first connection portion 17 c and the second connection portion 18 a, so that the intake manifold The unit 17, the exhaust manifold 18, and the stay 23 can be more securely fixed to the cylinder head 15. Further, since the center of gravity G3 of the intake manifold unit 17, the exhaust manifold 18 and the stay 23 is located between the first connection portion 17c and the second connection portion 18a, a moment is applied to the first connection portion 17c and the second connection portion 18a. Can be prevented from acting. As a result, the durability of the internal combustion engine 1 at the first connection portion 17c and the second connection portion 18a can be improved.

  Here, the stay 23 corresponds to a connecting member. The intake manifold unit 17, the exhaust manifold 18 and the stay 23 as a whole correspond to intake and exhaust system members. In the present embodiment, the stay 23 is supported only at the two locations of the intake boss portion 23a and the exhaust boss portion 23b. However, the stay 23 is further fixed to the internal combustion engine 1 at another location. May be. For example, the cylinder head cover 16 may be fixed by connecting the vicinity of the center of gravity G3 of the intake manifold unit 17, the exhaust manifold 18 and the stay 23 together.

  Then, the weights of the intake manifold unit 17, the exhaust manifold 18 and the stay 23 can be supported also in the cylinder head cover portion, and moment and shearing force act on the first connection portion 17c and the second connection portion 18a. Can be suppressed more reliably.

  In FIG. 3, the internal combustion engine 1 is mounted on the vehicle in an upright posture, and the cylinder block 3 moves relative to the crankcase 4 in the vertical direction. However, the posture of the internal combustion engine 1 is It is not limited to this. For example, as shown in FIG. 4, the whole internal combustion engine 1 may be inclined with respect to the vertical direction. In this case, the gravity center G3 of the intake manifold unit 17, the exhaust manifold 18 and the stay 23 as a whole is such that the horizontal position thereof is a vertical line passing through the first connection portion 17c indicated by the broken line in the drawing, and the second connection portion. It is comprised so that it may be located between the perpendicular lines which pass 18a. Then, as described above, the position of G3 in the vertical direction is on the straight line connecting G1 and G2, or slightly above the straight line. The position hardly changes. As a result, it can suppress that a moment acts on the 1st connection part 17c and the 2nd connection part 18a, and can improve the durability of the internal combustion engine 1 in the 1st connection part 17c and the 2nd connection part 18a.

  In FIG. 4, the two vertical lines indicated by broken lines pass through the first connecting portion 17c and the substantially central portion in the vertical direction of the second connecting portion 18a, but are strictly limited to this place. There is no need to be done. For example, the horizontal position of the center of gravity G3 may be arranged between the vertical lines passing through the outermost sides of the first connection part 17c and the second connection part 18a in FIG. You may comprise so that it may arrange | position between the perpendicular lines which pass the innermost side of the 1st connection part 17c and the 2nd connection part 18a.

Next, another aspect of the present embodiment will be described with reference to FIG. The intake manifold unit 24 in this aspect is constituted by an intake manifold 24a and an intake system module 24b. The intake system module 24b is formed by integrally forming a cylinder head cover, an air cleaner case, and the like in addition to a throttle body (not shown). In this embodiment, the intake system module 24b is mounted on the cylinder head 15 instead of the cylinder head cover. The stay 25 and the intake system module 24b are coupled to each other at the second intake-side boss portion 25a, and the stay 25 and the exhaust manifold 18 are coupled to each other at the second exhaust-side boss portion 25b. 18 are connected.

  Also in this aspect, the gravity center G3 of the intake manifold unit 24, the exhaust manifold 18 and the stay 25 as a whole is arranged between the first connection portion 24c and the second connection portion 18a.

  Then, since the intake manifold unit 24, the exhaust manifold 18 and the stay 25 are supported at the three points of the first connection portion 24c, the second connection portion 18a and the cylinder head 15, the intake manifold unit 24, the exhaust manifold The entire manifold 18 and stay 25 can be more securely fixed to the cylinder head 15. Further, since the center of gravity of the entire intake manifold unit 24, exhaust manifold 18 and stay 25 is located between the first connection portion 24c and the second connection portion 18a, it acts on the first connection portion 24c and the second connection portion 18a. The magnitude of the moment can be greatly reduced. As a result, the durability of the internal combustion engine 1 at the first connection portion 24c and the second connection portion 18a can be improved.

  Further, in the present embodiment, the stay 25 can be reduced in size, so that it is easy to increase the rigidity of the stay 25 itself.

  Next, a second embodiment of the present invention will be described. In this embodiment, an example will be described in which a cylinder block, a cylinder head, and an intake manifold or an exhaust manifold are supported by a three-point support stay that is coupled at three points.

  FIG. 6 shows a detailed configuration of the variable compression ratio internal combustion engine 1 in the present embodiment. In this embodiment, the exhaust manifold 28 is cast integrally with the cylinder head 15 in order to make the entire internal combustion engine 1 compact and improve the warm-up performance of the exhaust catalytic converter 32. Further, the exhaust pipe 33 connected to the exhaust catalytic converter 32 goes around to the lower side of the internal combustion engine 1, and a flexible pipe 29 is connected to the downstream side of the exhaust pipe 33. Further, on the downstream side of the flexible pipe 29, the exhaust pipe 33 is fixed to the crankcase 4 by an exhaust pipe stay 34.

  With the above configuration, in this embodiment, when the cylinder block 3 moves relative to the crankcase 4, the exhaust manifold 28, the exhaust catalytic converter 32, and the exhaust pipe 33 upstream of the flexible pipe 29 (hereinafter, “ The exhaust manifold 28 and the like ") move together.

  Here, in this embodiment, the intake manifold unit 17 and the exhaust manifold 28 are reinforced by being supported by the intake side three-point support stay 30 and the exhaust side three-point support stay 31, respectively. The intake side three-point support stay 30 includes an intake manifold unit at the third intake side boss portion 30a, at the cylinder head 15, at the fourth intake side boss portion 30b, at the cylinder block 3, and at the fifth intake side boss portion 30c. 17.

  On the other hand, the exhaust side three-point support stay 31 includes the cylinder head 15 in the third exhaust side boss portion 31a, the cylinder block 3 in the fourth exhaust side boss portion 31b, and the exhaust manifold 28 in the fifth exhaust side boss portion 31c. Combined with.

By adopting such a configuration, the cylinder block 3 is based on the weight and inertia of the intake manifold unit 17 when the cylinder block 3 moves relative to the crankcase 4 or when vibration or impact is applied to the internal combustion engine 1. It can suppress that a moment concentrates and acts only on the 1st connection part 17c. Similarly, the moment based on the weight and inertia of the exhaust manifold 28 or the like can be prevented from acting on only the second connection portion 28a.

  Further, here, the intake side three-point support stay 30 and the exhaust side three-point support stay 31 are to be supported on different parts of the cylinder head 15, the cylinder block 3, and the suction manifold unit 17 or the exhaust manifold 28, respectively. Thus, the distance between the three points to be supported can be increased.

  Thereby, the intake manifold unit 17 and the exhaust manifold 28 can be more reliably supported, and the rigidity of the intake side three-point support stay 30 and the exhaust side three-point support stay 31 itself can be secured. The intake manifold unit 17 and the exhaust manifold 28 can be reinforced more reliably. In the present embodiment, the intake side three-point support stay 30 and the exhaust side three-point support stay 31 correspond to auxiliary members.

  Here, the shapes of the intake side three-point support stay 30 and the exhaust side three-point support stay 31 can be considered as follows. FIG. 7 is a view for explaining a shape capable of efficiently supporting the exhaust manifold with respect to the exhaust side three-point support stay 31 as an example.

  In FIG. 7, X is the distance between the third exhaust side boss portion 31a and the fourth exhaust side boss portion 31b. L is a distance between a straight line connecting the third exhaust side boss part 31a and the fourth exhaust side boss part 31b and the fifth exhaust side boss part 31c. Further, θ is an inclination angle with respect to a horizontal line connecting the third exhaust side boss 31a and the fifth exhaust boss 31c, and φ is a connection between the fourth exhaust boss 31b and the fifth exhaust boss 31c. Indicates the angle of inclination of the straight line with respect to the horizontal line

Here, if the load P acts on the fifth exhaust side boss portion 31c, the load F1 acting in the direction of the straight line connecting the third exhaust side boss portion 31a and the fifth exhaust side boss portion 31c, and the fourth The loads F2 acting in the direction of the straight line connecting the exhaust side boss part 31b and the fifth exhaust side boss part 31c can be expressed as follows.
F1 = −P / (tan φ · cos θ−sin θ) (1)
F2 = −P / (sin φ−tan θ · cos φ) (2)

  Then, when the value of φ is small and the value of θ is large, both F1 and F2 are stably reduced. In other words, in this case, the efficiency of reinforcement by the exhaust side three-point support stay is improved. Further, when φ is small and θ is large, X is larger than L.

  In the present embodiment, the general cylinder block 3 and cylinder head 15 dimensions, the exhaust manifold 28 dimensions, and the end of the exhaust manifold 28 are supported with respect to the relationship of φ, θ, L, and X described above. In consideration of the point that can be efficiently reinforced, the exhaust manifold 18 can be optimally reinforced by the exhaust side three-point support stay 31 by setting φ to the range of 0 to 20 degrees. This range of φ can also be applied to the intake side three-point support stay 30.

  Further, regarding the relationship between X and L, under the condition that the value of φ is small and the value of θ is large, it is more efficient that X is larger than L and that the tip of the exhaust manifold 28 is supported. If the range of X ≦ L ≦ 2X is satisfied, the exhaust manifold 28 can be optimally reinforced by the exhaust side three-point support stay 31 more efficiently. Note that this range of L is also applicable to the intake side three-point support stay 30.

  However, the relationship between φ, θ, L, and X is an example of a desirable shape of the exhaust side three-point support stay 31 in the present embodiment, and from the relationship between φ, θ, L, and X described above. Even if it is detached, there is no problem as long as the intake manifold unit 17 and the exhaust manifold 28 can be sufficiently supported and reinforced.

  In the present embodiment, for example, the fifth exhaust side boss portion 31 c in the exhaust side three-point support stay 31 may be provided on the exhaust catalytic converter 32 or the exhaust pipe 33. This is because the heavy exhaust catalytic converter 32 is directly supported or the exhaust manifold 28 even if the relationship of φ, θ, L, X in the shape of the exhaust side three-point support stay 31 deviates from the aforementioned desirable relationship. This is because it may be possible to support and fix the exhaust manifold 28 and the like more reliably by supporting the tip side as much as possible.

  In the present embodiment, an auxiliary device such as a motor or a generator (not shown) may be integrally fixed by the intake side three-point support stay 30 or the exhaust side three-point support stay 31. That is, the intake side three-point support stay 30 or the exhaust side three-point support stay 31 may be used as a bracket for auxiliary equipment. If it does so, a number of parts can be reduced and cost reduction is attained.

  In the above embodiment, the case where the internal combustion engine 1 is a variable compression ratio internal combustion engine in which the cylinder block 3 and the crankcase 4 are relatively moved has been described. However, the present invention is applied to other internal combustion engines. It is possible.

1 is an exploded perspective view showing a schematic configuration of an internal combustion engine according to an embodiment of the present invention. It is sectional drawing which shows progress which the cylinder block in the internal combustion engine which concerns on the Example of this invention moves relatively with respect to a crankcase. 1 is a diagram illustrating a detailed configuration of a variable compression ratio internal combustion engine according to a first embodiment of the present invention. FIG. It is sectional drawing which shows another example of a detailed structure of the variable compression ratio internal combustion engine which concerns on Example 1 of this invention. It is sectional drawing which shows another example of the detailed structure of the variable compression ratio internal combustion engine which concerns on Example 1 of this invention. It is a figure which shows the detailed structure of the variable compression ratio internal combustion engine which concerns on Example 2 of this invention. It is a figure for demonstrating the desirable shape of the exhaust side 3 point | piece support stay which concerns on Example 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Cylinder 3 ... Cylinder block 4 ... Crankcase 9 ... Cam shaft 10 ... Gear 11a, 11b ... Worm gear 12 ... Motor 15 ... Cylinder head 16 ... Cylinder head covers 17, 24 ... Intake manifold units 17a, 24a ... Intake manifold 17b ... Throttle bodies 17c, 24c ... First connecting portions 18, 28 ... Exhaust manifold 18a , 28a, second connecting portion 19, 29, flexible vip 20, 33, exhaust pipe 21, 34, exhaust pipe stay 22, connection port 23, stay 23a, intake air. Side boss portion 23b ... Exhaust side boss portion 24b ... Intake system module 25 ... Stay 25a ... Second intake side boss portion 25b ... Second exhaust side boss 30 ... intake side three-point support stay 30a ... third intake side boss portion 30b ... fourth intake side boss portion 30c ... fifth intake side boss portion 31 ... exhaust side three point support stay 31a ... 3rd exhaust side boss part 31b ... 4th exhaust side boss part 31c ... 5th exhaust side boss part 32 ... Exhaust catalytic converter

Claims (6)

An intake system member that forms a part of the intake passage of the internal combustion engine by being fixed and connected to the internal combustion engine at an intake system connection portion;
An exhaust system member that forms a part of an exhaust passage of the internal combustion engine by being fixed and connected to the internal combustion engine at an exhaust system connection portion;
A coupling member that regulates a change in relative position of each other by coupling the intake system member and the exhaust system member;
The horizontal position of the center of gravity of the intake / exhaust system member constituted by the intake system member, the exhaust system member, and the connecting member passes through the vertical line passing through the intake system connection portion and the exhaust system connection portion. An internal combustion engine, which is located between a vertical line and a vertical line. A cylinder block in which a cylinder in the internal combustion engine is formed;
A crankcase in which the crankshaft in the internal combustion engine is assembled and the cylinder block is attached to be relatively movable;
The compression ratio changing means for changing the compression ratio of the internal combustion engine by moving the crankcase and the cylinder block relatively close to or away from each other. Internal combustion engine. A cylinder block in which a cylinder in the internal combustion engine is formed;
A cylinder head attached to the cylinder block and provided with a valve mechanism for the internal combustion engine;
2. The internal combustion engine according to claim 1, wherein the connecting member connects the intake system member and the exhaust system member by passing through a space opposite to the cylinder block with respect to the cylinder head. organ.   The internal combustion engine according to claim 2 or 3, wherein the intake system connection portion and the exhaust system connection portion are provided on the cylinder block or a member that does not move relative to the cylinder block. 5. The internal combustion engine according to claim 1, wherein the intake / exhaust system member is further fixed to the internal combustion engine at a place other than the intake system connection part and the exhaust system connection part. organ.   By coupling the cylinder block or a member that does not move relative to the cylinder block, and the intake system member and / or the exhaust system member, the intake system member and / or the exhaust system member to the internal combustion engine. The internal combustion engine according to claim 4, further comprising an auxiliary member that assists in fixing.

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