JP2009114989A - Variable compression ratio engine and engine system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine system including a cylinder block movement type variable compression ratio engine with almost no leakage of blow-by gas from between a crank case and a cylinder block of the variable compression ratio engine during the operation. <P>SOLUTION: The engine system comprises the variable compression ratio engine 10 sealed by a seal member 12a, formed with a suction hole at a lower part of the seal member 12a, and equipped with the cylinder block 12, an intake pipe 19 connected to a cylinder head 11 of the variable compression ratio engine 10, and a suction pipe 16 connecting the suction hole and the intake pipe 19 (a downstream part of a throttle). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a variable compression ratio engine that changes a compression ratio by relatively displacing a cylinder block with respect to a crankcase, and an engine system including such a variable compression ratio engine.

As is well known, if the compression ratio of the engine can be changed, the occurrence of knocking can be suppressed by lowering the compression ratio at high loads, and the torque can be extracted by increasing the compression ratio at low loads. become. For this reason, a variable compression ratio engine (see, for example, Patent Document 1) that changes the compression ratio by relatively displacing the cylinder block with respect to the crankcase, or variable compression in which the crankshaft and the connection rod are connected via a link. A ratio engine (see, for example, Patent Document 2) has been developed.
JP 2006-316770 A JP 2004-76695 A Japanese Utility Model Publication No. 61-116117

  The variable compression ratio engine of the type that displaces the cylinder block relative to the crankcase (hereinafter referred to as the cylinder block movement type) is compared with a variable compression ratio engine that employs other configurations. As a result, blow-by gas tends to leak out of the engine. This is because a cylinder block movement type variable compression ratio engine cannot firmly seal between the crankcase and the cylinder block for the purpose of displacing the cylinder block with respect to the crankcase.

  Accordingly, an object of the present invention is to provide a variable compression ratio engine that can be operated (operated) in such a manner that blow-by gas hardly leaks from between the crankcase and the cylinder block. There is to do.

  Another object of the present invention is an engine system including a cylinder block movement type variable compression ratio engine. During operation, blow-by gas leaks from between a crankcase and a cylinder block of the variable compression ratio engine. It is to provide an engine system that has little.

  In order to solve the above problems, in the present invention, a variable compression ratio engine that changes the compression ratio by relatively displacing the cylinder block with respect to the crankcase is provided between the inner surface of the crankcase and the side surface of the cylinder block. A sealing material for sealing the gap between the crankcase and the cylinder block is provided, and the crankcase wall surface is provided on a portion of the crankcase that is below the sealing material and always faces the side surface of the cylinder block. It is assumed that a suction hole penetrating through is attached.

In other words, in the variable compression ratio engine of the present invention, if the suction hole is connected to a portion downstream of the throttle of the intake pipe, a negative pressure source / gas suction source such as a suction pump, And the cylinder block. Therefore, the variable compression ratio engine of the present invention is a cylinder block moving type engine that can be operated (operated) in such a way that blow-by gas hardly leaks from between the crankcase and the cylinder block. Will be.

  When realizing (manufacturing) the variable compression ratio engine of the present invention, a second sealing material is provided between the inner surface of the crankcase and the side surface of the cylinder block, and the suction hole It can also be made to be formed in a portion between the sealing material and the second sealing material. When the variable compression ratio engine of the present invention is realized as an engine provided with the second seal material, it is possible not to provide the PCV valve in the crankcase by adjusting the sealing performance with the second seal material. However, it is desirable to provide a PCV valve in the crankcase.

  In addition, the variable compression ratio engine of the present invention can be realized as an engine in which an adsorption rubber that adsorbs to the side surface of the cylinder block due to its elasticity is used as a member that functions as a sealing material and a second sealing material.

  Furthermore, the variable compression ratio engine of the present invention is realized as an engine having a crankcase that is a member having a PCV valve and has a through-hole for connecting to a suction hole and a pipe. You can also.

  The engine system according to each claim of the present invention is a system in which a suction hole of a variable compression ratio engine is connected to a negative pressure source / gas suction source, the main component being the variable compression ratio engine of the present invention. It has become. Therefore, the engine system according to each claim of the present invention is a system including a variable compression ratio engine of a cylinder block moving type, and during operation, blow-by gas is generated between the crankcase and the cylinder block of the variable compression ratio engine. It can be said that the system has almost no leakage.

  According to the present invention, a variable compression ratio engine of a cylinder block movement type that can be operated in such a way that blowby gas hardly leaks from between the crankcase and the cylinder block. An engine system that hardly leaks from between the crankcase and the cylinder block of the specific engine can be realized.

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

<< First Embodiment >>
As shown in FIG. 1, the engine system according to the first embodiment of the present invention is a system (composite) including a variable compression ratio engine 10, an intake pipe 19, and a suction pipe 16.

  The variable compression ratio engine 10 provided in the engine system is an engine that changes the compression ratio by moving the cylinder block 12 up and down (in the axial direction of the cylinder; the crankshaft side is “down”) in the crankcase 13. .

More specifically, the variable compression ratio engine 10 includes two cam shafts 14 arranged so as to be parallel to the cylinder arrangement direction, and a drive mechanism for rotating each cam shaft 14 in the reverse direction. It is a four-cylinder inline engine. The cylinder arrangement direction is a direction perpendicular to the paper surface in FIG. 1, and the drive mechanism is a mechanism including a motor, a worm gear, and the like indicated by dotted lines in FIG. The camshaft 14 is a member in which a plurality of cam portions 14b and a plurality of movable bearing portions 14c (all of which are columnar members) are eccentrically attached to a shaft portion 14a. Each camshaft 14 included in the variable compression ratio engine 10 is a member attached to the shaft portion 14a so that each movable bearing portion 14c can rotate.

  In the variable compression ratio engine 10, each cam portion 14b of each cam shaft 14 is fixed to the cylinder block 12 in a rotatable manner. Each engine has a configuration in which each movable bearing portion 14c of each cam shaft 14 is fixed to the crankcase 13 in a rotatable manner.

  In short, the variable compression ratio engine 10 included in the engine system according to the present embodiment has the same basic configuration (configuration for changing the compression ratio) as the existing variable compression ratio engine.

  However, the variable compression ratio engine 10 is an engine adopting a special configuration (shape) as the cylinder block 12 and the crankcase 13.

  Specifically, as shown in FIG. 1 and FIG. 2, the cylinder block 12 has annular (shaped around the side surface) seal grooves 12a and 12b, and the side surfaces (each outer side parallel to the axial direction of the cylinder). The wall surface is always formed at a portion facing the inner surface (inner wall surface) of the crankcase 13.

  On the other hand, the crankcase 13 of the variable compression ratio engine 10 has the configuration (shape) shown in FIGS.

  That is, the crankcase 13 can be inserted into the seal groove 12x (x = a, b) by inserting the cylinder block 12 in which the ring-shaped seal material 15x is fitted into the seal groove 15x (x = a, b). It is the member of the shape where 12 spaces are sealed. The sealing materials 15a and 15b are the viewpoints that “an excessive force is not required for the vertical movement of the cylinder block 12 and that the crankcase 13 and the cylinder block 12 can be sufficiently sealed”. Therefore, it is a member (rubber material) whose material and shape are determined.

  Further, the crankcase 13 is formed with a recess between each portion of the inner surface that may be opposed to the seal groove 12x (in contact with the seal material 15x), and in the portion where the recess is formed. , A member in which a suction hole which is a through hole is formed.

  The variable compression ratio engine 10 is an engine in which the cylinder block 12 and the crankcase 13 having the above-described configuration and other various members (sealing materials 15a, 15b, etc.) are assembled as shown in FIG. Although not shown, the actual variable compression ratio engine 10 has a PCV (positive crankcase ventilation) valve in the lower part of the crankcase 13 (the part closer to the crankshaft than the part in contact with the seal material 15b). It is provided.

  In the engine system according to the present embodiment, the intake pipe 19 is connected to the intake port of the cylinder head 11 of the variable compression ratio engine 10, and the downstream portion of the intake pipe 19 (the portion on the cylinder head 11 side of the throttle). ) And the suction hole of the variable compression ratio engine 10 are connected by a suction pipe 16.

  As is apparent from the above description, the variable compression ratio engine 10 used in the engine system according to the first embodiment of the present invention has a space (a space below the seal material 15a) in which blow-by gas is stored as a seal material. The engine is divided into two spaces by 15b. Furthermore, the variable compression ratio engine 10 is an engine having a suction hole that can suck out gas in a space above the seal material 15b (hereinafter referred to as an upper space).

  The engine system according to the first embodiment is a system in which the suction hole of the variable compression ratio engine 10 and the intake pipe 19 (downstream portion of the throttle) are connected by the suction pipe 16. Therefore, during the operation of the engine system according to the first embodiment, the blow-by gas that has leaked into the upper space is returned to the cylinder (does not leak to the outside from the sealing material 15a side).

  For this reason, it can be said that the engine system according to the first embodiment is a system in which blow-by gas is extremely difficult to leak out of the variable compression ratio engine 10.

<< Second Embodiment >>
The engine system according to the second embodiment of the present invention is a modification of the engine system according to the first embodiment. For this reason, below, the structure of the engine system which concerns on 2nd Embodiment is demonstrated centering on the part which is different from the engine system which concerns on 1st Embodiment.

  As shown in FIG. 4, the engine system according to the second embodiment of the present invention includes a variable compression ratio engine 20 of a type that changes the compression ratio by moving the cylinder block 22 up and down in the crankcase 23. The system is the main component.

  The variable compression ratio engine 20 is different from the variable compression ratio engine 10 described above only in the following points.

  The variable compression ratio engine 20 is an engine using a cylinder block 22 having a flat side surface (no seal groove is formed on the side surface). The variable compression ratio engine 20 is an engine in which a member corresponding to the crankcase 23 in which seal grooves 23a and 23b are added to the crankcase 13 (FIG. 1) is used. The seal groove 23x (x = a, b) is a groove into which the seal material 25x corresponding to the seal material 15x described above is fitted when the variable compression ratio engine 20 is assembled.

  In the engine system according to the second embodiment, an intake pipe 29 is connected to the intake port of the cylinder head 21 of the variable compression ratio engine 20 having the above-described configuration, and a portion upstream of the throttle of the intake pipe 29 is In this system, the suction hole of the variable compression ratio engine 20 is connected by a suction pipe 26 having a suction pump 27.

  As is clear from the above description, the engine system according to the second embodiment of the present invention is also a system in which the gas in the upper space formed by the sealing materials 25a, 25b and the like is returned into the cylinder during its operation. It has become. Therefore, it can be said that the engine system according to the second embodiment is also a system in which blow-by gas is extremely difficult to leak out of the variable compression ratio engine 20.

  In the engine system according to the second embodiment, a suction pipe 26 having a suction pump 27 is connected to a suction hole and an intake pipe 29. For this reason, in the engine system according to the second embodiment, the connection destination of the suction pipe 26 that can suck the gas in the upper space more efficiently is not particularly limited (the suction pipe 26 can be connected to other than the negative pressure source). ) It will be a system.

<< Third Embodiment >>
The engine system according to the third embodiment of the present invention is a modification of the engine system according to the second embodiment. For this reason, below, the structure of the engine system which concerns on 3rd Embodiment is demonstrated centering on the part which is different from the engine system which concerns on 2nd Embodiment.

  As shown in FIG. 5, the engine system according to the third embodiment of the present invention includes a variable compression ratio engine 30 of a type that changes the compression ratio by moving a cylinder block 32 up and down in a crankcase 33. The system is the main component.

  The variable compression ratio engine 30 used in this engine system is essentially the same configuration as the variable compression ratio engine 20 (FIG. 4).

  That is, the variable compression ratio engine 30 is an engine in which the cylinder block 32 has a flat side surface. Further, the variable compression ratio engine 30 has a crankcase 33 having a member formed with seal grooves 33a, 33b, recesses, and suction holes for fitting ring-shaped seal members 35a, 35b in the upper part of the inner surface thereof. It is the engine used.

  Thus, the variable compression ratio engine 30 is essentially the same configuration as the variable compression ratio engine 20 (FIG. 4). However, as shown in the figure, the cylinder block 32 of the variable compression ratio engine 30 is provided with a through hole in the lower portion thereof for connection by a suction hole and a suction pipe 36.

  The engine system according to the third embodiment is a system in which the suction hole of the variable compression ratio engine 30 and the through hole are connected by a suction pipe 36 including a vacuum tank 37 and a suction pump 38.

  As is clear from the above description, the engine system according to the third embodiment of the present invention is such that after the gas in the upper space formed by the sealing materials 25a, 25b and the like is once returned into the crankcase 33, The system is returned to the cylinder via a PCV valve (not shown). For this reason, the engine system according to the third embodiment also functions as a system in which blow-by gas is extremely difficult to leak out of the variable compression ratio engine 30.

<< 4th Embodiment >>
The engine system according to the fourth embodiment of the present invention is also a modification of the engine system according to the second embodiment. For this reason, below, the structure of the engine system which concerns on 4th Embodiment is demonstrated centering on the part which is different from the engine system which concerns on 2nd Embodiment.

FIG. 6 shows the configuration of an engine system according to the fourth embodiment of the present invention.
The variable compression ratio engine 40 used in this engine system is an engine having the same configuration as the variable compression ratio engine 20 (FIG. 4).

  That is, the variable compression ratio engine 40 includes a cylinder block 42 having a flat side surface, a seal case 43a, 43b for fitting ring-shaped seal members 45a, 45b, a recess, and a crankcase 43 in which a suction hole is formed. It is an engine composed of

In the engine system according to the fourth embodiment, the intake pipe 49 is connected to the intake port of the cylinder head 41 of the variable compression ratio engine 40, and the downstream portion of the throttle of the intake pipe 49 and the variable compression ratio engine 40 are connected. The suction hole is connected to a suction tank 47 by a vacuum tank 47 having two check valves and a suction pipe 46.

  As is clear from the above description, the engine system according to the present embodiment is also a system in which the gas in the upper space formed by the sealing materials 45a, 45b and the like is returned into the cylinder during its operation. Therefore, it can be said that this engine system is also a system in which blow-by gas is extremely difficult to leak out of the variable compression ratio engine 40.

  The engine system according to the fourth embodiment is a system in which a vacuum tank 47 is provided on the path from the upper space to the intake pipe 29. Therefore, the engine system according to the fourth embodiment is a system in which blow-by gas does not leak out of the variable compression ratio engine 40 even if the downstream portion of the throttle of the intake pipe 49 temporarily becomes positive pressure. Also become.

<< 5th Embodiment >>
FIG. 7 shows the configuration of an engine system according to the fifth embodiment of the present invention.

  As shown in the figure, the engine system according to the seventh embodiment of the present invention is a system including a variable compression ratio engine 50, an intake pipe 59, and a suction pipe 56.

  The variable compression ratio engine 50 provided in this engine system is an engine corresponding to a modification of the variable compression ratio engine 10 (FIG. 1) so that an upper space is formed by one adsorption rubber 55.

  More specifically, the crankcase 53 of the variable compression ratio engine 50 has the same configuration as that of the crankcase 13 (a recess and a suction hole are formed). On the other hand, the cylinder block 52 is a member in which a recess having substantially the same size as the portion from the seal groove 12a to the seal groove 12b in the cylinder block 12 is formed in a portion corresponding to the portion.

  The adsorption rubber 55 used in the variable compression ratio engine 50 is an annular member (rubber material) having a cross-sectional shape as illustrated. That is, the suction rubber 55 is a member (a member corresponding to an annular vacuum suction pad) having a shape that can be sucked to the bottom surface (side surface of the cylinder block 52) of a recess on the cylinder block 52 side (hereinafter also referred to as a case side recess). ).

  The shape of the suction rubber 55 is determined so that the suction rubber 55 can be slightly moved up and down in the case-side recess and can always seal the cylinder block 52 and the crankcase 53 at two locations. It has become a member. In other words, when the cylinder block 52 is moved up and down in the crankcase 53, the suction rubber 55 slightly moves up and down in the case-side recess because a small amount of oil film exists on the bottom surface of the case-side recess. It is a member. In addition, the suction rubber 55 can be attached to the cylinder block 52 and the crankcase 53 regardless of the position of the cylinder block 52 in the crankcase 53 and the position of the suction rubber 55 in the case-side recess. It is a member that can be sealed at two locations.

  In the engine system according to the present embodiment, the intake pipe 59 is connected to the intake port of the cylinder head 51 of the variable compression ratio engine 50, the downstream portion of the intake pipe 59, the suction hole of the variable compression ratio engine 50, and Are connected by a suction pipe 56 having a check valve.

As is clear from the above description, the engine system according to the fifth embodiment of the present invention also has the gas in the upper space (the space constituted by the adsorption rubber 55 and the wall surfaces of the recesses of the crankcase 53). The system is returned to the cylinder during operation. Therefore, it can be said that the engine system according to the fifth embodiment is also a system in which blow-by gas is extremely difficult to leak out of the variable compression ratio engine 50.

  Further, in the variable compression ratio engine 50 used in the engine system according to the fifth embodiment, when the cylinder block 52 is moved up and down in the crankcase 53, the suction rubber 55 moves up and down in the recess on the case side. It has become an engine. Therefore, the variable compression ratio engine 50 requires less force to change the compression ratio than the variable compression ratio engine 10 or the like in which two sealing materials are fixed to the cylinder block or the crankcase (drive with a simpler configuration). It can be said that the engine can adopt the mechanism.

<Deformation>
Each engine system and each variable compression ratio engine described above can be modified in various ways. For example, the variable compression ratio engine according to the first to fourth embodiments can be transformed into an engine having only an upper sealing material (such as the sealing material 15a). Further, when the variable compression ratio engine according to the first to fourth embodiments is modified to such an engine, the PCV valve can be removed. Although the meaning of sealing at two locations is reduced, the PCV valve can be changed from the variable compression ratio engine according to each embodiment except the third embodiment without changing the configuration related to the sealing material. Can also be removed.

  Furthermore, the variable compression ratio engine according to each embodiment can be modified to a crankcase in which a recess is not intentionally formed. However, when the variable compression ratio engine according to each embodiment is modified to such a thing (and there is almost no gap between the crankcase and the cylinder block), the gas in the part away from the suction hole is difficult to be sucked. Will end up. For this reason, it is desirable to form a recess in the crankcase (or cylinder block) as in the above embodiments.

  In addition, the engine system / variable compression ratio engine according to each embodiment has a specific configuration different from that described above (the presence or absence of check valves and installation locations are different, and the number of formed suction holes is different. It is a matter of course that it may be deformed into a thing etc.).

It is explanatory drawing of a structure of the engine system which concerns on 1st Embodiment. It is explanatory drawing of the cylinder block used for the variable compression ratio engine in the engine system which concerns on 1st Embodiment. It is explanatory drawing of the crankcase currently used for the variable compression ratio engine in the engine system which concerns on 1st Embodiment. It is explanatory drawing of a structure of the engine system which concerns on 2nd Embodiment. It is explanatory drawing of a structure of the engine system which concerns on 3rd Embodiment. It is explanatory drawing of a structure of the engine system which concerns on 4th Embodiment. It is explanatory drawing of a structure of the engine system which concerns on 5th Embodiment.

Explanation of symbols

10, 20, 30, 40, 50 Variable compression ratio engine 11, 21, 31, 41, 51 Cylinder head 12a, 12b, 23a, 23b, 33a, 33b, 43a, 43b Seal groove 12, 22, 32, 42, 52 Cylinder block 15a, 15b, 25a, 25b, 35a, 35b, 45a, 45b Seal material 13, 23, 33, 43, 53 Crankcase 14 Cam shaft 14a Shaft portion 14b Cam portion 14c Movable bearing portion 16, 26, 36, 46 , 56 Suction pipe 19, 29, 39, 49, 59 Intake pipe 27, 38 Suction pump 37, 47 Vacuum tank 55 Adsorption rubber

Claims (8)

In a variable compression ratio engine that changes the compression ratio by displacing the cylinder block relative to the crankcase,
Between the inner surface of the crankcase and the side surface of the cylinder block, a sealing material for sealing a gap between the crankcase and the cylinder block is provided,
A variable compression ratio engine, characterized in that a suction hole that penetrates the wall surface of the crankcase is attached to a portion of the crankcase that is always below the seal material and that faces the side surface of the cylinder block. A second sealing material is provided between the inner surface of the crankcase and the side surface of the cylinder block,
The variable compression ratio engine according to claim 1, wherein the suction hole is formed in a portion of the crankcase between the sealing material and the second sealing material. The variable compression ratio engine according to claim 2, wherein an adsorption rubber that adsorbs to a side surface of the cylinder block due to its elasticity is used as a member that functions as the sealing material and the second sealing material. A variable compression ratio engine according to any one of claims 1 to 3,
An intake pipe connected to an intake port of a cylinder head of the variable compression ratio engine;
An engine system comprising: a suction pipe that connects the suction hole of the variable compression ratio engine and the intake pipe. The suction pipe is
The engine system according to claim 4, further comprising: a pipe connected to the suction hole of the variable compression ratio engine at a portion downstream of the throttle of the intake pipe. The suction pipe is
The variable compression ratio engine according to claim 5, wherein the variable compression ratio engine is a pipe provided with a vacuum tank on the path. The suction pipe is
The variable compression ratio engine according to claim 4, wherein the pipe is provided with a suction pump for sucking gas from the suction hole on the path. The crankcase is
The variable member according to any one of claims 1 to 3, wherein the variable hole is a member provided with a PCV valve and a through hole for connecting to the suction hole with a pipe. Compression ratio engine.

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