JP2008069656A - Stroke characteristic variable engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cam phase control device and a stroke characteristic variable engine for improving a degree of freedom of link arrangement and mounting performance to an engine room of an automobile. <P>SOLUTION: A starter 21 is arranged on the side of not positioning a connection point P of a lower link 5 and a control link 12 and an eccentric shaft 13, that is, on the illustrated left side, in an axial directional view of a crankshaft 6, in a crankcase 7 of an engine 1. Thus, a locus of the connection point P of the lower link 5 and the control link 12, the length of the control link 12 and a position of the eccentric shaft 13, can be optimally set, and engine performance can be improved. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a variable stroke characteristic engine, and more particularly, to a technique for improving the degree of freedom in designing a link arrangement and improving the mountability of an automobile in an engine room.

The lower link rotatably supported by the crank pin of the crankshaft, the upper link connecting the lower link and the piston, and the control link connecting the eccentric shaft supported by the engine body and the lower link A variable stroke characteristic engine that changes a piston stroke by rotating an eccentric shaft is known (see Patent Document 1). On the other hand, a starter is installed on the side of the engine body, and at the start, a flywheel (ring gear) is rotationally driven by the starter.
JP 2003-322036 A

  In the above-described variable stroke characteristics engine, due to the existence of an eccentric shaft and a control link, one side wall of the engine main body (usually, a crankcase) greatly protrudes when the crankshaft is viewed in the axial direction. For this reason, when the starter is arranged carelessly, there are problems that the degree of freedom in designing the link arrangement (the eccentric shaft and the control link) is reduced, and the mountability in the engine room of the automobile is deteriorated.

  The present invention has been made in view of the above situation, and an object thereof is to provide a cam phase control device and a stroke characteristic variable engine that improve freedom of link arrangement and mountability in an engine room of an automobile. To do.

  According to a first aspect of the present invention, there is provided a lower link rotatably supported by a crankpin of a crankshaft, an upper link connecting the lower link and a piston, an eccentric shaft supported by an engine body, and the lower link. A variable stroke characteristic engine that changes a piston stroke by rotating the eccentric shaft, and the engine body has a crankshaft as viewed in an axial direction of the crankshaft. The starter is installed on the side where the connecting point between the lower link and the control link is not located with reference to a straight line passing through the axis of the cylinder and parallel to the cylinder axis.

  According to a second aspect of the present invention, there is provided a lower link rotatably supported by a crankpin of a crankshaft, an upper link connecting the lower link and the piston, an eccentric shaft supported by an engine body, and the lower And a control link for connecting to the link, and a variable stroke characteristic engine that changes a piston stroke by rotating the eccentric shaft. The starter is installed on the side where the eccentric shaft is not located with reference to a straight line passing through the axis of the crankshaft and parallel to the cylinder axis.

  According to a third aspect of the present invention, there is provided a lower link rotatably supported by a crankpin of a crankshaft, an upper link connecting the lower link and the piston, an eccentric shaft supported by an engine body, and the lower A variable-stroke-characteristic engine that changes a piston stroke by rotating the eccentric shaft, wherein the eccentric is located above a connection point between the lower link and the control link. A shaft is located, and the engine body is provided with a starter below a connection point between the lower link and the control link in the axial direction of the crankshaft.

  According to a fourth aspect of the present invention, there is provided a lower link rotatably supported by a crankpin of a crankshaft, an upper link connecting the lower link and the piston, an eccentric shaft supported by an engine body, and the lower A variable-stroke-characteristic engine that changes a piston stroke by rotating the eccentric shaft, wherein a transmission is connected to one end of the engine body, and a cylinder on the transmission side The connection point between the lower link and the control link in the cylinder is located below the connection point between the lower link and the control link in the other cylinders, and the connection point between the lower link and the control link is below the connection point. Eccentric sha The engine body is provided with a starter installed above a connection point between the lower link and the control link in the cylinder on the transmission side in the axial direction of the crankshaft. .

  According to a fifth aspect of the present invention, there is provided a lower link rotatably supported by a crankpin of a crankshaft, an upper link connecting the lower link and the piston, an eccentric shaft supported by an engine body, and the lower A variable-stroke-characteristic engine that changes a piston stroke by rotating the eccentric shaft, the eccentric link being below a connection point between the lower link and the control link. A shaft is located, and the engine main body is provided with a starter above a connection point between the lower link and the control link as viewed in the axial direction of the crankshaft.

  According to a sixth aspect of the present invention, there is provided a lower link rotatably supported by a crankpin of a crankshaft, an upper link connecting the lower link and the piston, an eccentric shaft supported by an engine body, and the lower A variable-stroke-characteristic engine that changes a piston stroke by rotating the eccentric shaft, the eccentric link being below a connection point between the lower link and the control link. A shaft is located, and in the engine body, a starter is installed above a connection point between the lower link and the control link in an axial view of the crankshaft, and a connection point between the lower link and the control link. From said crankshaft axis Distance to, characterized in that always less than the distance from the eccentric shaft to the axis of the crankshaft.

  According to the variable stroke characteristic engine of the first aspect, the starter does not limit the arrangement of the connection points between the lower link and the control link, and the optimum link arrangement is possible. According to the variable stroke characteristic engine of claim 2, the starter does not limit the arrangement of the eccentric shaft, and the optimum link arrangement is possible. Further, according to the variable stroke characteristic engine of claim 3, since there is no starter on the side where the control link or the eccentric shaft is not installed in the engine body, the space of the part can be used effectively and the degree of freedom of mounting the engine, etc. Will also improve. Further, according to the variable stroke characteristic engine of the fourth aspect, vibration can be reduced by changing the connection point between the lower link and the control link between the cylinders while securing the starter installation portion. Further, according to the variable stroke characteristic engine of claim 5, since there is no starter on the side where the control link or the eccentric shaft is not installed in the engine body, the space of the part can be used effectively and the degree of freedom of mounting the engine, etc. Will also improve. Further, according to the sixth aspect of the variable stroke characteristic engine, the space can be used more effectively than in the fifth aspect of the variable stroke characteristic engine, and the degree of freedom for mounting the engine is further improved.

  Hereinafter, several embodiments of a variable compression ratio engine to which a variable stroke characteristic engine of the present invention is applied will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a front view showing a schematic configuration of a variable compression ratio engine according to a first embodiment of the present invention. Although the illustration above the cylinder head is omitted in FIG. 1, the valve operating mechanism, the intake system, and the exhaust system provided in the cylinder head are not different from those of a normal 4-cycle engine.

  As shown in FIG. 1, the piston 3 slidably engaged with the cylinder 2 of the engine 1 is connected to a crankshaft 6 via an upper link 4 and a lower link 5. The crankshaft 6 has basically the same configuration as that of a normal fixed compression ratio engine, and a crankpin 9 eccentric from a crank journal 8 (center of rotation of the crankshaft) supported in a crankcase (engine body) 7 is provided. I have. An intermediate portion of the lower link 5 that swings in a seesaw manner is supported on the crank pin 9, and a large end portion 4 b of the upper link 4 is connected to one end 5 a of the lower link 5 and a small end portion 4 a to the piston pin 10. Has been. The crankshaft 6 is provided with a counterweight mainly for reducing the rotational primary vibration component of the piston motion, but this is also the same as that of a normal reciprocating engine and is omitted.

  The other end 5b of the lower link 5 is pin-coupled with a small end portion 12a of the control link 12 having the same configuration as a connecting rod for connecting a piston and a crankshaft in a normal engine. The large end portion 12b of the control link 12 is connected to the eccentric portion 13a of the eccentric shaft 13 that is rotatably supported by the crankcase 7 and extends in parallel with the crankshaft 6, with a bearing hole 14 divided in two. Has been. In the case of the present embodiment, the control link 12 and the eccentric shaft 13 are located on the right side of the reference line L passing through the axis of the crankshaft 6 and parallel to the cylinder axis, and the lower link 5 and the control link 12 The connecting point P is naturally located on the right side of the reference line L in the drawing.

  The eccentric shaft 13 supports the large end portion 12b of the control link 12 so as to be movable within a predetermined range (about 90 degrees in this embodiment) within the crankcase 7, and is driven by an actuator (not shown). Thus, the rotation angle is continuously changed according to the operating state of the engine 1 and is held at an arbitrary angle.

  In the engine 1 of the first embodiment, the position of the large end portion 12b of the control link 12 changes between the horizontal inward direction and the vertical downward direction shown in FIG. 1 by rotating the eccentric shaft 13. Then, the swing angle of the lower link 5 changes as the crankshaft 6 rotates. The stroke range of the piston 3 in the cylinder 2, that is, the top dead center position and the bottom dead center position of the piston 3 are continuously changed according to the change in the swing angle of the lower link 5. That is, a piston stroke variable mechanism is constituted by the upper link 4, the lower link 5, the control link 12, and the eccentric shaft 13, and thereby, a stroke characteristic variable function for continuously changing at least one of the compression ratio and the exhaust amount. Is brought about.

  The crankcase 7 of the engine 1 has a starter on the side where the connecting point P of the lower link 5 and the control link 12 and the eccentric shaft 13 are not located, that is, on the left side of the reference line L in the drawing, as viewed in the axial direction of the crankshaft 6. 21 is installed. As a result, in the first embodiment, the locus of the connection point P between the lower link 5 and the control link 12, the length of the control link 12, the position of the eccentric shaft 13 and the like can be optimally set. Improvements were realized.

[Second Embodiment]
FIG. 2 is a front view showing a schematic configuration of a variable compression ratio engine according to the second embodiment of the present invention.
As shown in FIG. 2, in the engine 1 of the second embodiment, the eccentric shaft 13 is located above the connection point P between the lower link 5 and the control link 12, and the crankcase 7 The starter 21 is installed below the connection point P between the lower link 5 and the control link 12 when viewed in the axial direction. Thereby, in 2nd Embodiment, the overhang | projection in the one side of the crankcase 7 was suppressed small, and it became easy to arrange the engine 1 in inclination in the engine room of a motor vehicle, etc.

[Third Embodiment]
FIG. 3 is a front view showing a schematic configuration of a variable compression ratio engine according to a third embodiment of the present invention, and FIG. 4 is a side view showing a schematic configuration of the variable compression ratio engine according to the third embodiment.
As shown in FIGS. 3 and 4, the engine 1 of the third embodiment is an in-line four-cylinder engine, and a transmission 31 is connected to the rear end portion. In the present embodiment, in order to suppress the secondary vibration component and the fourth vibration component, the control links 12 of the first and fourth cylinders are set to be short, and the control links 12 ′ of the second and third cylinders (indicated by a two-dot chain line). (Shown) is set longer. Further, the upper link 4 and the lower link 5 of the first and fourth cylinders also correspond to the control links 12 and 12 ', and the upper link 4' and the lower link 5 'of the second and third cylinders (these are also two links). The length and shape are different from those indicated by the dotted line).

  In the third embodiment, since the connection point P between the control link 12 and the lower link 5 is located below the connection point P ′ between the control link 12 ′ and the lower link 5 ′, the cranks on the first and fourth cylinders side The contour 71 of the case 7 is located below the contour 71 ′ of the crankcase 7 on the second and third cylinder side. Since the starter 21 is installed on the transmission 31 side (that is, the fourth cylinder side), the starter 21 avoids the contour 71 ′ of the crankcase 7 on the second and third cylinder sides.

[Fourth Embodiment]
FIG. 5 is a front view showing a schematic configuration of a variable compression ratio engine according to the fourth embodiment of the present invention.
As shown in FIG. 5, in the engine 1 of the fourth embodiment, the eccentric shaft 13 is located below the connection point P between the lower link 5 and the control link 12, and the crankcase 7 The starter 21 is installed above the connecting point P between the lower link 5 and the control link 12 when viewed in the axial direction. In the fourth embodiment, the distance L1 from the connection point P between the lower link 5 and the control link 12 to the axial center of the crankshaft 6 is the axial center of the crankshaft 6 from the axial center of the eccentric portion 13a of the eccentric shaft 13. Since the distance L2 is always set smaller than the distance L2, the position of the starter 21 can be made relatively low. Accordingly, in the fourth embodiment, the overhang on one side of the crankcase 7 is suppressed to be small, and the engine 1 can be easily disposed in an inclined manner in the engine room of the automobile.

  Although the description of the specific embodiment is finished as described above, the present invention can be widely modified without being limited to the above-described embodiment and modifications. For example, although the above-described embodiments and modifications are those in which the present invention is applied to an in-line engine, it is naturally applicable to a V-type engine or the like. In addition, the specific configuration and the like of the stroke characteristic variable mechanism can be changed as appropriate without departing from the gist of the present invention.

1 is a front view showing a schematic configuration of a variable compression ratio engine according to a first embodiment. It is a front view which shows schematic structure of the variable compression ratio engine which concerns on 2nd Embodiment. It is a front view which shows schematic structure of the variable compression ratio engine which concerns on 3rd Embodiment. It is a side view which shows schematic structure of the variable compression ratio engine which concerns on 3rd Embodiment. It is a front view which shows schematic structure of the variable compression ratio engine which concerns on 4th Embodiment.

Explanation of symbols

1 Engine 2 Cylinder 3 Piston 4 Upper link 5 Lower link 6 Crankshaft 7 Crankcase 12 Control link 13 Eccentric shaft 21 Starter 41 Transmission P Connection point

Claims (6)

A lower link rotatably supported by a crankpin of the crankshaft, an upper link connecting the lower link and the piston, an eccentric shaft supported by an engine body, and a control link connecting the lower link A stroke characteristic variable engine that changes a piston stroke by rotating the eccentric shaft,
In the engine body, the connection point between the lower link and the control link is not located with respect to a straight line passing through the axis of the crankshaft and parallel to the cylinder axis in the axial direction of the crankshaft. A variable stroke characteristic engine characterized by the installation of a starter. A lower link rotatably supported by a crankpin of the crankshaft, an upper link connecting the lower link and the piston, an eccentric shaft supported by an engine body, and a control link connecting the lower link A stroke characteristic variable engine that changes a piston stroke by rotating the eccentric shaft,
The engine body is provided with a starter on the side where the eccentric shaft is not located with respect to a straight line passing through the axis of the crankshaft and parallel to the cylinder axis in the axial direction of the crankshaft. Variable stroke characteristics engine. A lower link rotatably supported by a crankpin of the crankshaft, an upper link connecting the lower link and the piston, an eccentric shaft supported by an engine body, and a control link connecting the lower link A stroke characteristic variable engine that changes a piston stroke by rotating the eccentric shaft,
The eccentric shaft is located above the connection point between the lower link and the control link;
A variable stroke characteristic engine characterized in that a starter is installed in the engine body below a connection point between the lower link and the control link in the axial direction of the crankshaft. A lower link rotatably supported by a crankpin of the crankshaft, an upper link connecting the lower link and the piston, an eccentric shaft supported by an engine body, and a control link connecting the lower link A stroke characteristic variable engine that changes a piston stroke by rotating the eccentric shaft,
A transmission is connected to one end of the engine body,
A connection point between the lower link and the control link in the transmission-side cylinder is located below a connection point between the lower link and the control link in another cylinder;
The eccentric shaft is located above the connection point between the lower link and the control link;
The stroke variable variable engine according to claim 1, wherein a starter is installed in the engine body above a connection point between the lower link and the control link in the cylinder on the transmission side in the axial direction of the crankshaft. A lower link rotatably supported by a crankpin of the crankshaft, an upper link connecting the lower link and the piston, an eccentric shaft supported by an engine body, and a control link connecting the lower link A stroke characteristic variable engine that changes a piston stroke by rotating the eccentric shaft,
The eccentric shaft is located below the connection point between the lower link and the control link,
A variable stroke characteristic engine characterized in that a starter is installed in the engine body above a connection point between the lower link and the control link in the axial direction of the crankshaft. A lower link rotatably supported by a crankpin of the crankshaft, an upper link connecting the lower link and the piston, an eccentric shaft supported by an engine body, and a control link connecting the lower link A stroke characteristic variable engine that changes a piston stroke by rotating the eccentric shaft,
The eccentric shaft is located below the connection point between the lower link and the control link,
In the engine body, in the axial direction view of the crankshaft, a starter is installed above a connection point between the lower link and the control link,
A variable stroke characteristic engine characterized in that a distance from a connection point between the lower link and the control link to an axis of the crankshaft is always smaller than a distance from the eccentric shaft to the axis of the crankshaft.

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