JP2006300006A - Variable compression ratio internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable compression ratio internal combustion engine whose compression ratio is changed with a change in the capacity of a combustion chamber, offering technology for developing more stable output. <P>SOLUTION: A crank shaft 8 connected to a piston via a link member is provided separately from an output shaft 9. The rotation of the crank shaft 8 is transmitted to the output shaft via rotation transmitting means 11, 12. When the compression ratio of the internal combustion engine is changed, the crank shaft 8 is moved on a circular arc as a moving passage around the output shaft 9 so that the positions of the top dead center and the bottom dead center of the piston in a cylinder are moved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a variable compression ratio internal combustion engine that changes a compression ratio by changing the volume of a combustion chamber.

  In recent years, variable compression ratio internal combustion engines that change the compression ratio by changing the volume of the combustion chamber have been developed for the purpose of improving the fuel efficiency performance and output performance of the internal combustion engine. As such a variable compression ratio internal combustion engine, for example, there is an engine in which the crankshaft is supported by a bearing with an eccentric disk and the axis of the crankshaft is moved by rotating the eccentric shaft (for example, see Non-Patent Document 1). .) According to this, when the axial center of a crankshaft moves, the top and bottom dead center of a piston shifts uniformly, As a result, the volume of a combustion chamber changes.

  Also known is a variable compression ratio internal combustion engine in which a crankshaft is arranged so that the center of rotation is offset from the center axis of the piston, and the piston pin and the crankpin are connected via a first connecting rod and a second connecting rod. (For example, refer to Patent Document 1). In such a variable compression ratio internal combustion engine, one end of the first connecting rod is connected to the piston pin, and one end and the other end of the second connecting rod are connected to the other end of the first connecting rod and the crank pin, respectively. ing. Then, by moving the connecting portion between the other end of the first connecting rod and one end of the second connecting rod in the axial direction of the piston by the link arm, the upper and lower dead centers of the piston are uniformly shifted.

Patent Document 2 discloses a structure in an internal combustion engine in which an output shaft is disposed at a position away from the center line of a cylinder and a reciprocating motion of a piston is converted into a rotational motion of the output shaft by a link mechanism. In Patent Document 2, the output shaft is rotated by swinging a link having one end connected to the output shaft around the output shaft by a reciprocating motion of a piston.
“FEV Variable Compression Ratio—Crankshaft Position Control”, Engine Technology, Sankai-do Co., Ltd., February 26, 2003, No. 24, p. 26-28 JP 2003-83101 A JP 2004-138229 A JP 2003-83102 A

  An object of the present invention is to provide a technique capable of obtaining more stable output in a variable compression ratio internal combustion engine that changes the compression ratio by changing the volume of the combustion chamber.

  In the present invention, the crankshaft connected to the piston via the link member and the output shaft are separately provided, and the rotation of the crankshaft is transmitted to the output shaft by the rotation transmitting means. When the compression ratio of the internal combustion engine is changed, the position of the piston with respect to the cylinder at the top dead center and the bottom dead center is moved by moving the crankshaft on the arc centered on the output shaft.

More specifically, the variable compression ratio internal combustion engine according to the present embodiment is
A variable compression ratio internal combustion engine in which the compression ratio is changed by changing the volume of the combustion chamber,
A crankshaft connected to the piston via a link member and rotating in conjunction with the reciprocating motion of the piston;
An output shaft disposed substantially parallel to the crankshaft and rotatably supported;
Rotation transmission means for rotating the output shaft by transmitting rotation of the crankshaft to the output shaft;
Shaft moving means for moving the crankshaft as a movement path on an arc centered on the output shaft, and
By moving the crankshaft by the shaft moving means, the positions of the top dead center and the bottom dead center of the piston with respect to the cylinder are moved, thereby changing the volume of the combustion chamber.

  In the present invention, the output shaft is disposed substantially parallel to the crankshaft connected to the piston, and the output shaft is rotatably supported. Then, the rotation of the crankshaft is transmitted to the output shaft by the rotation transmitting means, whereby the output shaft rotates.

  In the present invention, when changing the compression ratio, the crankshaft is moved by the shaft moving means. At this time, the crankshaft moves on an arc centered on the output shaft. As a result, the crankshaft moves in the axial direction of the cylinder.

  When the crankshaft moves in this way, the positions of the top dead center and the bottom dead center of the piston with respect to the cylinder also move accordingly. As a result, the volume of the combustion chamber changes and the compression ratio is changed.

  In the present invention, since the movement path when the crankshaft moves is on an arc centered on the output shaft, the distance between the crankshaft and the output shaft does not change even if the crankshaft moves. . Therefore, the output generated by operating the variable compression ratio internal combustion engine can always be taken out from the same position. Furthermore, the rotation of the crankshaft can be more easily transmitted to the output shaft by the rotation transmitting means than when the distance between the crankshaft and the output shaft changes with the change of the compression ratio. That is, the rotation of the crankshaft can be more stably transmitted to the output shaft.

  Therefore, according to the present invention, it is possible to obtain a more stable output in the variable compression ratio internal combustion engine.

  Furthermore, in the present invention, even if the compression ratio is changed, the distance between the crankshaft and the output shaft does not change, so that it is possible to use a rotation transmitting means such as a gear that does not have elasticity. . By using such a rotation transmission means, it becomes possible to transmit the rotation of the crankshaft to the output shaft more efficiently. That is, the output can be obtained more efficiently.

  In the present invention, the crankshaft and the output shaft may be installed in a crankcase connected to the cylinder.

  When the crankshaft and the output shaft are installed in the crankcase, the rotation of the crankshaft can be transmitted to the output shaft in the crankcase.

Further, when the output shaft is installed in the crankcase, it is necessary to transmit the rotation of the output shaft to a drive system outside the crankcase. At this time, if the output shaft moves along with the change of the compression ratio, the airtightness of the crankcase may be lowered. However, according to the present invention, as described above, the output shaft does not move even when the compression ratio is changed, and the output can always be taken out from the same position.

  Therefore, according to the said structure, the fall of the airtightness of a crankcase can be suppressed.

  In the present invention, the shaft moving means includes a connecting portion between the arm member having the crankshaft rotatably connected to one end and the output shaft rotatably connected to the other end, and the output shaft of the arm member. Arm swinging means for swinging the arm member as a center may be provided. In this case, when changing the compression ratio, the arm member is swung by the arm swinging means. As a result, the crankshaft moves on an arc centered on the output shaft.

  That is, in the case of the above configuration, the crankshaft and the output shaft are connected to one end and the other end of the arm member, respectively, so that the distance between the crankshaft and the output shaft can be kept constant. Further, by swinging the arm member around the connection portion with the output shaft, the crankshaft can be moved so that the moving path is on an arc centered on the output shaft.

  Therefore, according to the above configuration, the compression ratio can be changed by swinging the arm member. The arm member only needs to be operated when changing the compression ratio, and can be fixed at other times. That is, it is not necessary to use a mechanism that is always operating during operation of the internal combustion engine as a part of the mechanism for changing the compression ratio. Therefore, the durability of the variable compression ratio internal combustion engine can be improved, and the compression ratio can be controlled with higher accuracy.

  Further, in the present invention, the center axis of the crankshaft and the center axis of the output shaft are arranged in a portion of the arm member that is closer to the connection portion with the crankshaft than the connection portion with the output shaft (hereinafter simply referred to as the crank side portion). In the case where an inclined surface inclined with respect to a plane including is formed, the arm swinging means is provided with a protruding portion that is in contact with the inclined surface formed on the arm member, and the inclined surface formed on the arm member You may have a slide member which slides in the direction which cross | intersects the plane containing. In this case, when changing the compression ratio, the slide member is slid while the inclined surface formed on the arm member and the projection are brought into contact with each other.

  By sliding the slide member in this manner, the inclined surface is pressed by the protrusion of the slide member, and the arm member is pushed up (or pushed down). However, since the supported output shaft is connected to the other end of the arm member, the position of the other end of the arm member does not move even if the inclined surface is pressed by the protrusion of the slide member. Therefore, by sliding the slide member as described above, the arm member can be swung around the connection portion with the output shaft.

  In the case of the above-described configuration, the protrusion provided on the slide member may be a slider-side protrusion, and a plurality of arm-side protrusions on which the inclined surface is formed may be provided on the crank side portion of the arm member. Further, in such a case, a plurality of slider-side protrusions may be provided on the slide member so as to contact each of the inclined surfaces formed on the arm-side protrusions.

  Thus, by providing a plurality of arm-side protrusions and slider-side protrusions, it is possible to reduce the surface pressure at the contact portions of each protrusion.

  In the present invention, the arm swinging means has an arm link member whose one end is rotatably connected to a crank side portion of the arm member, and the other end of the arm link member is rotatably connected. And a slide member. In this case, when changing the compression ratio, the slide member is slid while swinging the arm link member.

  When the slide member is slid in this manner and the arm link member swings, the arm member is pressed by the arm link member, and the arm member is pushed up (or pushed down). However, as described above, since the supported output shaft is connected to the other end of the arm member, even if the arm member is pressed by the arm link member, the other end of the arm member The position does not move. Therefore, by sliding the slide member as described above, the arm member can be swung around the connection portion with the output shaft.

  In the present invention, when the arm member is the first arm member, the arm swinging means includes a second arm member whose one end is rotatably and slidably connected to a crank side portion of the first arm member. And a support member that rotatably supports the middle of the second arm member. In this case, when changing the compression ratio, the second arm member is swung around the portion supported by the support member by moving the other end of the second arm member.

  As described above, when the second arm member is swung, the one end portion of the first arm member is moved along with the movement of the one end portion of the second arm member. However, even in this case, the position of the other end of the first arm member does not move as described above. That is, by moving the other end of the second arm member as described above, the first arm member can be swung around the connection portion with the output shaft. Moreover, the surface pressure concerning the other end part of this 2nd arm member can be reduced by supporting the other end part of a 2nd arm member in the state of surface contact.

  In the present invention, the arm swinging means may have a cam arranged so as to be in contact with a crank side portion of the arm member. In this case, the cam is rotated when changing the compression ratio.

  When the cam rotates, the arm member is pressed by the cam, and the arm member is pushed up (or pushed down). However, even in this case, the position of the other end of the arm member does not move as described above. That is, by rotating the cam, the arm member can be swung around the connection portion with the output shaft.

  In the present invention, the arm swinging means may have a gear installed so as to be in contact with the crank side portion of the arm member. In this case, the arm member is provided with an uneven portion that meshes with the gear. And when changing a compression ratio, a gearwheel is rotated.

  Also in this case, the position of the other end portion of the arm member does not move as described above. Therefore, by rotating the gear, the arm member can be swung around the connection portion with the output shaft.

  In the present invention, the arm swinging means may include a slanting member having a plurality of slanted hairs provided on the wall surface, and a vibration device that vibrates the slanted hair member. In this case, the plurality of inclined hairs provided on the inclined hair member are inclined in the same direction as intersecting with a plane including the central axis of the crankshaft and the central axis of the output shaft. Further, the inclined hair member is disposed so that the end portion of the inclined hair is in contact with the crank side portion of the arm member. Then, when changing the compression ratio, the inclined hair member is vibrated by the vibration device.

  In this case, the oblique hair vibrates with the vibration of the oblique hair member, and the arm member is moved by the vibration of the oblique hair. However, in this case as well, the position of the other end of the arm member does not move as described above. Therefore, the arm member can be swung around the connecting portion with the output shaft by vibrating the oblique hair member.

  In the present invention, a hole in which a spiral groove is formed on the wall surface may be provided in the connection portion of the arm member with the output shaft so that the central axis thereof is the same as the central axis of the output shaft. . The arm swinging means may include an insertion member that is inserted into a hole provided in the arm member and has a convex portion formed on a side surface that fits into a groove formed in a wall surface of the hole. . In this case, when changing the compression ratio, the insertion member is moved in the axial direction without rotating in the hole.

  When the insertion member moves in this way, the convex portion formed on the insertion member moves in the axial direction of the hole while fitting with the groove formed on the wall surface of the hole. Here, since the insertion member does not rotate and the groove is formed in a spiral shape on the wall surface of the hole, the arm member rotates as the convex portion moves. That is, by moving the insertion member as described above, the arm member can be swung around the connection portion with the output shaft.

  According to the present invention, an output can be obtained more stably in a variable compression ratio internal combustion engine that changes the compression ratio by changing the volume of the combustion chamber.

  Hereinafter, specific embodiments of a variable compression ratio internal combustion engine according to the present invention will be described with reference to the drawings.

<Schematic configuration of internal combustion engine>
FIG. 1 is a diagram showing a schematic configuration of a variable compression ratio internal combustion engine according to the present embodiment. A variable compression ratio internal combustion engine 1 (hereinafter simply referred to as an internal combustion engine 1) includes four cylinders 2 arranged in series. A piston 3 is slidably provided in the cylinder 2. A combustion chamber 4 surrounded by the inner wall surface of the cylinder 2 and the upper surface of the piston 3 is formed in the upper part of the cylinder 2.

  A crankcase 5 is connected to the lower end of the cylinder 2. A crankshaft 8 connected to the piston 3 via a connecting rod 6 is provided in the crankcase 5. One end of the connecting rod 6 is rotatably connected to the piston 3, and the other end of the connecting rod 6 is rotatably connected to the crank pin of the crankshaft 8. The crankshaft 8 is not fixed with respect to the crankcase 5 and is movable.

  In the crankcase 5, an output shaft 9 is provided that is disposed substantially parallel to the crankshaft 8. The output shaft 9 is rotatably supported by the crankcase 5.

  A crank side gear 11 is connected to the crankshaft 8, and an output side gear 12 is connected to the output shaft 9. The crank side gear 11 and the output side gear 12 are fitted to each other, and the rotation of the crankshaft 8 is transmitted to the output shaft 9 by these gears 11 and 12. That is, the crankshaft 8 rotates with the linear motion of the piston 3, and the crankshaft 11 rotates as the crankshaft 8 rotates. Then, the output side gear 12 rotates with the rotation of the crank side gear 11, and the output shaft 9 rotates as the output side gear 12 rotates. The rotation of the output shaft 9 is transmitted to a power transmission system outside the internal combustion engine 1.

Further, in this embodiment, an arm member 10 having a crankshaft 8 rotatably connected to one end and an output shaft 9 rotatably connected to the other end is provided. Here, the connection position of the arm member 10 in the crankshaft 8 will be described with reference to FIG. FIG. 2 is a view of the crankshaft 8 as viewed from above. Note that 10e in FIG. 2 represents a connecting rod connecting portion which is a portion where a crank pin to which the connecting rod 6 is connected is formed on the crankshaft 8.

  As shown in FIG. 2, a crank side gear 11 is connected to both ends of the crankshaft 8 outside the portion where the connecting rod connecting portion 10 e is provided. The arm members 10 are connected to both ends on the outer side of the portion of the crankshaft 8 to which the crank-side gear 11 is connected. That is, in this embodiment, two arm members 10 are provided. Each end of the crankshaft 8 is connected to each end. The two arm members 10 are installed so as to be substantially parallel to each other, and the other end portions of the two arm members 10 are connected to the output shaft 9.

  Returning to FIG. 1, one end of the arm member 10 is bent downward in FIG. 1. By this bending, inclined surfaces 10 a and 10 b that are inclined with respect to a plane including the central axis of the crankshaft 8 and the central axis of the output shaft 9 are formed on the upper surface and the lower surface of one end portion of the arm member 10. Here, the inclined surface formed on the upper surface at one end of the arm member 10 is referred to as an inclined surface 10a, and the inclined surface formed on the lower surface at one end of the arm member 10 is referred to as an inclined surface 10b. The inclined surface 10a and the inclined surface 10b are formed so as to be substantially parallel to each other.

  Further, a swing device 13 for swinging the arm member 10 around the connecting portion with the output shaft 9 is provided in the crankcase 5. The swing device 13 includes a first slider 14 and a second slider 15, and a drive device 16 that slides the first and second sliders 14 and 15.

  The first slider 14 slides in the axial direction of the arm member 10 above the arm member 10 in FIG. Further, the second slider 15 slides below the arm member 10 in FIG. 1 in the axial direction of the arm member 10. That is, the first and second sliders 14 and 15 slide in a direction intersecting with a plane including the inclined surfaces 10 a and 10 b formed on the arm member 10. The first and second sliders 14 and 15 are slid substantially parallel to each other.

  One end of the first slider 14 is provided with a protrusion 14a protruding downward. The protrusion 14 a is provided so as to contact the inclined surface 10 a of the arm member 10. On the other hand, one end of the second slider 15 is provided with a protrusion 15a protruding upward. The protrusion 15 a is provided so as to contact the inclined surface 10 b of the arm member 10. That is, the first and second sliders 14 and 15 are arranged so that the portions of the arm member 10 where the inclined surfaces 10a and 10b are formed are sandwiched between the protrusions 14a and 15a. By arranging the first and second sliders 14 and 15 in this way, one end of the arm member 10 is supported by them.

  Further, the other end portions of the first and second sliders 14 and 15 are inserted into the driving device 16, and the first and second sliders 14 and 15 are moved by the driving device 16 to the arm member 10 in FIG. It can be slid in the axial direction.

  The internal combustion engine 1 configured as described above is provided with an ECU 20 for controlling the internal combustion engine 1. The ECU 20 is a unit that controls the operation state of the internal combustion engine 1 in accordance with the operation conditions of the internal combustion engine 1 and the request of the driver. A drive device 16 is electrically connected to the ECU 20, and the drive device 16 is controlled by the ECU 20.

<How to change compression ratio>
Next, a method for changing the compression ratio of the internal combustion engine 1 according to this embodiment will be described with reference to FIG. FIG. 3A shows the state of the arm member 10 when the compression ratio is high, and FIG. 3B shows the state of the arm member 10 when the compression ratio is low.

  As shown in FIG. 3A, at the time of a high compression ratio, the first slider 14 is controlled so that the protrusion 14a is in contact with a relatively lower portion of the inclined surface 10a of the arm member 10. At this time, the second slider 15 is controlled such that the protruding portion 15 a contacts a relatively lower portion of the inclined surface 10 b of the arm member 10. In the present embodiment, the first and second sliders 14 and 15 are controlled as described above at the time of a high compression ratio, so that a plane including the central axis of the crankshaft 8 and the central axis of the output shaft 9 is obtained. The sliding directions of the first and second sliders 14 and 15 are substantially parallel.

  When the compression ratio of the internal combustion engine 1 is changed from the high compression ratio to the low compression ratio, the drive device 16 pushes the drive device 16 in the direction (direction indicated by the chain line arrow in FIG. 3B). The first and second sliders 14 and 15 are slid. At this time, the first slider 14 is slid in a state where the protrusion 14 a is in contact with the inclined surface 10 a of the arm member 10, and the second slider 15 is in a state where the protrusion 15 a is in contact with the inclined surface 10 b of the arm member 10. Slide.

  By sliding the first and second sliders 14 and 15 in this way, the inclined surface 10a is pressed by the protrusion 14a of the first slider 14, and the arm member 10 is pressed down.

  However, as described above, the output shaft 9 supported by the crankcase 5 is rotatably connected to the other end of the arm member 10. Therefore, when the arm member 10 is pushed down by the protrusion 14a, the arm member 10 swings downward (in the direction indicated by the solid arrow in FIG. 3B) around the connection portion with the output shaft 9. .

  As described above, when the arm member 10 swings, the rotation center of the crankshaft 8 moves downward, and accordingly, the top dead center and the bottom dead center of the piston 3 move below the cylinder 2. As a result, the volume of the combustion chamber 4 increases and the compression ratio decreases.

  At the time of a low compression ratio, as shown in FIG. 3B, the contact position of the protrusion 14a on the inclined surface 10a and the contact position of the protrusion 15a on the inclined surface 10b are relatively different on the inclined surfaces 10a and 10b. It will be in the upper position.

  Conversely, when the compression ratio of the internal combustion engine 1 is increased, the first and second sliders 14 and 15 are slid by the driving device 16 so as to be pulled into the driving device 16 from the state shown in FIG. . Thereby, the inclined surface 10b of the arm member 10 is pressed by the protrusion 15a of the second slider 15, and the arm member 10 is pushed up. Therefore, the arm member 10 swings upward about the connection portion with the output shaft 9.

  As described above, when the arm member 10 swings, the center of rotation of the crankshaft 8 moves upward, and accordingly, the top dead center and the bottom dead center of the piston 3 move above the cylinder 2. As a result, the volume of the combustion chamber 4 is reduced and the compression ratio is increased.

  As described above, in this embodiment, even when the compression ratio is changed, only the crankshaft 8 moves and the output shaft 9 does not move. Therefore, the output generated by operating the internal combustion engine 1 can always be taken out from the same position.

Further, since the crankshaft 8 is moved by swinging the arm member 10 about the connection portion with the output shaft 9, the movement path of the crankshaft 8 is on an arc centered on the output shaft 9. That is, even if the crankshaft 8 is moved to change the compression ratio, the distance between the crankshaft 8 and the output shaft 9 does not change. Therefore, the rotation of the crankshaft 8 can be transmitted to the output shaft 9 only by the crank side gear 11 connected to the crankshaft 8 and the output side gear 12 connected to the output shaft 9. That is, the rotation of the crankshaft 8 can be transmitted to the output shaft 9 more easily than when the distance between the crankshaft 8 and the output shaft 9 changes with the change of the compression ratio. That is, the rotation of the crankshaft 8 can be transmitted to the output shaft 9 more stably.

  Therefore, according to the present embodiment, it is possible to obtain a more stable output in the variable compression ratio internal combustion engine.

  In the present embodiment, as described above, the compression ratio is changed by swinging the arm member 10. The arm member 10 only needs to be operated when the compression ratio is changed. In other cases, the arm member 10 can be fixed by being supported by the first and second sliders 14 and 15. That is, according to the present embodiment, it is not necessary to use a mechanism that is always operating during operation of the internal combustion engine 1 as a part of the mechanism for changing the compression ratio. Therefore, the durability of the internal combustion engine 1 can be improved, and the compression ratio can be controlled with higher accuracy.

  In this embodiment, not only the crankshaft 8 but also the output shaft 9 is installed in the crankcase 5. Therefore, the rotation of the crankshaft 8 can be transmitted to the output shaft 9 in the crankcase 5. Furthermore, according to the present embodiment, as described above, the output shaft 9 does not move even when the compression ratio is changed, and the output can always be taken out from the same position. Accordingly, it is possible to suppress a decrease in the airtightness of the crankcase 5.

  As a means for transmitting the rotation of the crankshaft 8 to the output shaft 9, a chain or a belt may be used instead of the gears 11 and 12.

  However, as described above, in this embodiment, the distance between the crankshaft 8 and the output shaft 9 does not change even if the compression ratio is changed. The rotation of the crankshaft 8 can be transmitted to the output shaft 9 by the side gear 12. By transmitting the rotation of the crankshaft 8 to the output shaft 9 by the gears 11 and 12 as compared with the case where a device having elasticity is used as a means for transmitting the rotation of the crankshaft 8 to the output shaft 9, The rotation of the crankshaft 8 can be transmitted to the output shaft 9 more efficiently. That is, the output can be obtained more efficiently.

  In this embodiment, two arm members 10 are provided and one end of each is connected to both ends of the crankshaft 8. However, as shown in FIG. 4, three or more arm members 10 are provided. It is good also as a composition. FIG. 4 is a view when the crankshaft 8 is viewed from above, as in FIG. 2, and is a view when three or more arm members 10 are provided. In this case, in addition to both ends of the crankshaft 8, the arm member 10 is also connected between the connecting rod connecting portions 10e of the crankshaft 8. The arm members 10 are installed so as to be substantially parallel to each other, and the other end portions of the arm members 10 are connected to the output shaft 9. As described above, by adding the arm member 10, vibration generated when the crankshaft 8 rotates can be suppressed.

<Modification>
Hereinafter, a modification of the present embodiment will be described with reference to FIGS. FIG. 5 is a diagram illustrating a schematic configuration of the arm member 10 and the second slider 15 according to a first modification of the present embodiment. FIG. 6 is a diagram illustrating a schematic configuration of the arm member 10 and the second slider 15 according to the second modification of the present embodiment.

<First modification>
In the first modification of the present embodiment, as shown in FIG. 5, a plurality of arm-side protrusions 21 are provided on the side surface of the crank-side portion of the arm member 10 on the second slider 15 side. Each arm-side protrusion 21 is formed with an inclined surface 21 a that is inclined in the same direction as the inclined surface 10 b formed at one end of the arm member 10.

  Further, the second slider 15 is provided with a plurality of protrusions 15a. Then, not only the inclined surface 10 b formed at one end of the arm member 10 but also the inclined surface 21 a formed at each arm side protruding portion 21 is in contact with the protruding portion 15 a formed at the second slider 15. .

  Even with such a configuration, the compression ratio of the internal combustion engine 1 can be changed by sliding the first and second sliders 14 and 15 in the same manner as described above. Moreover, the surface pressure of the mutual contact part in each projection part 21 and 15a can be reduced by providing the several projection parts 21 and 15a in the arm member 10 and the 2nd slider 15, respectively.

  In addition, the protrusion part 21 which has the inclined surface 21a is provided in the one end part of the arm member 10 on the 1st slider 14 side side surface and the 2nd slider 15 side side surface of the arm member 10 without providing the inclined surfaces 10a and 10b. It is good also as the structure comprised.

<Second modification>
In the second modification of the present embodiment, as shown in FIG. 6, the contact portion of the protrusion 15a of the second slider 15 with the inclined surface 10b of the arm member 10 is at the same angle as the inclined surface 10b. The inclined surface 15b is inclined.

  According to such a configuration, the inclined surface 10b of the arm member 10 and the protrusion 15a of the second slider 15 are in surface contact. Therefore, the surface pressure at the contact portion between the inclined surface 10 b of the arm member 10 and the protrusion 15 a of the second slider 15 can be reduced.

  FIG. 7 is a diagram illustrating a schematic configuration of the arm member 10 and the swing device 13 according to the present embodiment. In the internal combustion engine according to the present embodiment, the configuration other than the arm member 10 and the swinging device 13 is the same as that of the above-described first embodiment, and thus the description thereof is omitted.

  In the present embodiment, as in the first embodiment, the crankshaft 8 is rotatably connected to one end of the arm member 10, and the output shaft 9 is rotatable to the other end of the arm member 10. It is connected. In addition, instead of the inclined surfaces 10a and 10b according to the first embodiment, a link mounting portion 10c is provided on the lower surface of one end portion of the arm member 10.

  The swing device 13 according to the present embodiment includes a slider 22 instead of the first and second sliders 14 and 15 according to the first embodiment. Similar to the first and second sliders 14 and 15 according to the first embodiment, the other end of the slider 22 is inserted into the drive device 16, and the lower side of the arm member 10 in FIG. Slide in the direction.

  In addition, at one end portion of the slider 22, a link attachment portion 22c formed so as to protrude toward the arm member 10 is provided. And the one end part of the link member 24 is connected to the link attachment part 10c provided in the one end part of the arm member 10 so that rotation is possible. Further, the other end portion of the link member 24 is rotatably connected to the link attaching portion 22c provided at one end portion of the slider 22. The link member 24 is provided with a stopper 25.

  In the present embodiment, when the compression ratio of the internal combustion engine 1 is changed, the slider 22 is slid by the driving device 16. When the slider 22 is slid, the link member 24 swings. Therefore, the arm member 10 is pressed or pulled by the link member 24, and thereby the arm member 10 is pushed up or pulled down. However, as described above, since the output shaft 9 supported by the crankcase 5 is connected to the other end portion of the arm member 10, the arm member 10 is pressed or attracted by the link member 24. However, the position of the other end of the arm member 10 does not move. For this reason, the arm member 10 swings around the connection portion with the output shaft 9.

  That is, in this embodiment, as shown in FIG. 7, when the link member 24 is substantially perpendicular to the slider 22, one end of the arm member 10 is pushed up to the highest position by the link member 24. It will be. Therefore, the compression ratio of the internal combustion engine 1 is a high compression ratio. When the link member 24 is inclined with respect to the slider 22 by sliding the slider 22, one end of the arm member 10 is pulled down by the link member 24, thereby reducing the compression ratio of the internal combustion engine 1.

  As described above, also by the configuration according to the present embodiment, by sliding the slider 22, the arm member 10 can be swung around the connection portion with the output shaft 9 as in the first embodiment. Thus, the compression ratio of the internal combustion engine 1 can be changed.

  In this embodiment, when the link member 24 swings, the stopper 25 provided on the link member 24 also swings. The stopper 25 is shaped so as to be sandwiched between the arm member 10 and the slider 22 in each case of the high compression ratio and the low compression ratio. When the stopper 25 is sandwiched between the arm member 10 and the slider 22, the arm member 10 is supported and its position is fixed.

  Further, the slider 22 may be provided above the arm member 10 in FIG. In this case, when the arm member 10 is pressed by the link member 24, the arm member 10 is pushed down, and when the arm member 10 is pulled by the link member 24, the arm member 10 is pushed up. Therefore, even with such a configuration, the arm member 10 can be swung around the connection portion with the output shaft 9.

  Further, the link member attaching portion 10 c may be provided on the crank side of the arm member 10, not the one end portion of the arm member 10.

  FIG. 8 is a diagram illustrating a schematic configuration of the arm member 10 and the swing device 13 according to the present embodiment. In the internal combustion engine according to the present embodiment, the configuration other than the arm member 10 and the swinging device 13 is the same as that of the above-described first embodiment, and thus the description thereof is omitted.

  In this embodiment, the arm member 10 is the first arm member 10. As in the first embodiment, the crankshaft 8 is rotatably connected to one end of the first arm member 10, and the output shaft 9 is rotatably connected to the other end of the first arm member 10. ing. The swing device 13 according to this embodiment includes a second arm member 26, a support member 27 that supports the second arm member 26, and a drive device 28.

One end of the second arm member 26 is rotatably and slidably connected to one end of the first arm member 10. The middle of the second arm member 26 is rotatably supported by a support member 27. The support member 27 is disposed on the side opposite to the output shaft 9 side with respect to the connection portion between the first arm member 10 and the second arm member 26. The other end of the second arm member 26 is inserted into the driving device 28. The drive device 28 can move the other end of the second arm member 26 in the vertical direction in FIG. 8, that is, in the swinging direction of the first arm member 10. The drive device 28 is electrically connected to the ECU 20 and controlled by the ECU 20, similarly to the drive device 16 according to the first embodiment.

  In the present embodiment, when the compression ratio of the internal combustion engine 1 is changed, the other end portion of the second arm member 26 is moved by the drive device 28. When the other end of the second arm member 26 is moved, the second arm member 26 swings around the portion supported by the support member 27. As a result, one end of the first arm member 10 connected to one end of the second arm member 26 is pushed up or pushed down. Therefore, the first arm member 10 swings around the connection portion with the output shaft 9.

  As described above, also in the configuration according to the present embodiment, the other end portion of the second arm member 26 is moved in the vertical direction in FIG. , And the compression ratio of the internal combustion engine 1 can be changed.

  Further, according to the present embodiment, the second arm member 26 has the other end portion as a power point, a portion supported by the support member 27 as a support point, and one end portion as an action point. 10 is swung. Therefore, by increasing the distance from the other end of the second arm member 26 to the portion supported by the support member 27, the compression ratio can be changed with a smaller driving force.

  In the present embodiment, the one end of the second arm member 26 may be connected to the crank side of the arm member 10 instead of the one end of the arm member 10.

  FIG. 9 is a diagram illustrating a schematic configuration of the arm member 10 and the swing device 13 according to the present embodiment. In the internal combustion engine according to the present embodiment, the configuration other than the arm member 10 and the swinging device 13 is the same as that of the above-described first embodiment, and thus the description thereof is omitted.

  In the present embodiment, as in the first embodiment, the crankshaft 8 is rotatably connected to one end of the arm member 10, and the output shaft 9 is rotatable to the other end of the arm member 10. It is connected. The swing device 13 according to the present embodiment includes a cam 29 and a drive device 30 that drives the cam 29. The cam 29 is disposed so as to contact the lower surface at one end of the arm member 10. Similarly to the drive device 16 according to the first embodiment, the drive device 30 is electrically connected to the ECU 20 and controlled by the ECU 20.

  In this embodiment, when changing the compression ratio of the internal combustion engine 1, the cam 29 is rotated by the drive device 30. When the cam 29 rotates, one end portion of the arm member 10 is pushed up by the cam 29 or moved downward. Therefore, the arm member 10 swings around the connection portion with the output shaft 9.

  As described above, even with the configuration according to the present embodiment, by rotating the cam 29, the arm member 10 can be swung around the connection portion with the output shaft 9 as in the first embodiment. Thus, the compression ratio of the internal combustion engine 1 can be changed.

In the present embodiment, the cam 29 may be installed so as to be in contact with the crank side of the arm member 10, not the one end portion of the arm member 10.

  FIG. 10 is a diagram illustrating a schematic configuration of the arm member 10 and the swing device 13 according to the present embodiment. In the internal combustion engine according to the present embodiment, the configuration other than the arm member 10 and the swinging device 13 is the same as that of the above-described first embodiment, and thus the description thereof is omitted.

  In the present embodiment, as in the first embodiment, the crankshaft 8 is rotatably connected to one end of the arm member 10, and the output shaft 9 is rotatable to the other end of the arm member 10. It is connected. The swing device 13 according to the present embodiment includes a gear 31 and a drive device 32 that rotates the gear 31.

  The gear 31 is disposed so as to be in contact with the end surface 10 d at one end of the arm 29. The end surface 10 d at one end of the arm 29 is provided with an uneven portion that meshes with the gear 31. Further, the drive device 32 is electrically connected to the ECU 20 and controlled by the ECU 20, similarly to the drive device 16 according to the first embodiment.

  In the present embodiment, when changing the compression ratio of the internal combustion engine 1, the gear 31 is rotated by the drive device 32. When the cam 29 rotates, one end of the arm member 10 is pushed up or pushed down by the gear 31. For this reason, the arm member 10 swings around the connection portion with the output shaft 9.

  As described above, even with the configuration according to the present embodiment, by rotating the gear 31, the arm member 10 can be swung around the connection portion with the output shaft 9 as in the first embodiment. Thus, the compression ratio of the internal combustion engine 1 can be changed.

  In the present embodiment, the gear 31 may be disposed so as to be in contact with the side surface of the arm member 10 on the crank side. In this case, a concavo-convex portion that meshes with the gear 31 is provided on the side surface of the arm member 10 in contact with the gear 31.

  As the gear 31 according to the present embodiment, a spur gear, a worm, a rack, or the like can be used.

  FIG. 11 is a diagram illustrating a schematic configuration of the arm member 10 and the swing device 13 according to the present embodiment. In the internal combustion engine according to the present embodiment, the configuration other than the arm member 10 and the swinging device 13 is the same as that of the above-described first embodiment, and thus the description thereof is omitted.

  In the present embodiment, as in the first embodiment, the crankshaft 8 is rotatably connected to one end of the arm member 10, and the output shaft 9 is rotatable to the other end of the arm member 10. It is connected. The oscillating device 13 according to the present embodiment includes an inclined hair member 33 provided with a plurality of inclined hairs 33a on a wall surface, and a vibration device 34 that vibrates the inclined hair member 33.

  The inclined hairs 33a formed on the wall surface of the inclined hair member 33 are inclined in the same direction that intersects a plane including the central axis of the crankshaft 8 and the central axis of the output shaft 9. Further, the inclined hair member 33 is disposed so that the end portion of the inclined hair 33 a is in contact with the end surface 10 d of one end portion of the arm member 10. The vibration device 34 can vibrate the oblique hair member 33. Similar to the driving device 16 according to the first embodiment, the vibration device 34 is electrically connected to the ECU 20 and controlled by the ECU 20.

  In the present embodiment, when changing the compression ratio of the internal combustion engine 1, the inclined hair member 33 is vibrated by the vibration device 34. As the slanted hair member 33 vibrates, the slanted hair 33a also vibrates, and one end of the arm member 10 moves due to the vibration of the slanted hair 33a. Therefore, the arm member 10 swings around the connection portion with the output shaft 9.

  As described above, also by the configuration according to the present embodiment, the arm member 10 can be swung around the connection portion with the output shaft 9 by vibrating the inclined hair member 33 as in the first embodiment. Thereby, the compression ratio of the internal combustion engine 1 can be changed.

  In the present embodiment, the inclined hair member 33 may be arranged so that the end portion of the inclined hair 33a is in contact with the side surface of the arm member 10 on the crank side.

  FIG. 12 is a diagram illustrating a schematic configuration of the arm member 10 according to the present embodiment. FIG. 13 is a diagram illustrating a schematic configuration of the swing device 13 according to the present embodiment, and is a cross-sectional view when the arm member 10 is cut at a portion indicated by an alternate long and short dash line A in FIG. 12. In the internal combustion engine according to the present embodiment, the configuration other than the arm member 10 and the swinging device 13 is the same as that of the above-described first embodiment, and thus the description thereof is omitted.

  In the present embodiment, as in the first embodiment, the crankshaft 8 is rotatably connected to one end of the arm member 10, and the output shaft 9 is rotatable to the other end of the arm member 10. It is connected. In this embodiment, as shown in FIGS. 12 and 13, the central axis of the connecting portion of the arm member 10 to the output shaft 9 is the same as the central axis of the output shaft 9 and the diameter thereof is the output shaft 9. A hole 35 having a diameter larger than that of the hole 35 is provided. That is, the output shaft 9 passes through the hole 35 with a gap between the output shaft 9 and the hole 35. A groove is spirally formed on the wall surface of the hole 35.

  As shown in FIG. 13, the rocking device 13 according to the present embodiment includes an insertion member 36 inserted into the hole 35, and the axial direction of the insertion member 36 in the hole 35 (direction indicated by an arrow in FIG. 13). A driving device 37 that can be moved without being rotated is provided. On the outer peripheral side surface of the insertion member 36, a convex portion that fits into a groove formed on the wall surface of the hole 35 is formed.

  In the present embodiment, when the compression ratio of the internal combustion engine 1 is changed, the drive unit 37 moves the insertion member 36 in the axial direction of the hole 35 without rotating in the state of being inserted into the hole 35. When the insertion member 36 moves in this way, the convex portion formed on the insertion member 36 moves in the axial direction of the hole 35 while fitting with the groove formed on the wall surface of the hole 35. Here, since the insertion member 36 does not rotate and the groove is formed in a spiral shape on the wall surface of the hole 35, the arm member 10 rotates with the movement of the convex portion. That is, the arm member 10 swings around the connection portion with the output shaft 9.

  As described above, even in the configuration according to the present embodiment, the arm member 10 is connected to the output shaft 9 by moving the insertion member 36 in the axial direction of the hole 35 without rotating. And the compression ratio of the internal combustion engine 1 can be changed.

  Instead of the swing device 13 according to the present embodiment, a rotation mechanism whose rotation axis is the same as the central axis of the output shaft 9 and which is rotated by a motor, a harmonic drive mechanism or the like is used as an arm according to the present embodiment. You may attach to the position of the hole 35 of the member 10. FIG. In this case, the arm member 10 can be swung around the connection portion with the output shaft 9 by rotating the rotation mechanism.

  FIG. 14 is a diagram illustrating a schematic configuration of the arm member 10 and the swing device 13 according to the present embodiment. In the internal combustion engine according to the present embodiment, the configuration other than the arm member 10 and the swinging device 13 is the same as that of the above-described first embodiment, and thus the description thereof is omitted.

  In the present embodiment, as in the first embodiment, the crankshaft 8 is rotatably connected to one end of the arm member 10, and the output shaft 9 is rotatable to the other end of the arm member 10. It is connected. The swinging device 13 according to the present embodiment includes an expansion / contraction mechanism 38 that expands and contracts in the axial direction of the arm member 10 in FIG. I have.

  The telescopic mechanism 38 includes first and second sliders 41 and 42 that slide in the axial direction of the arm member 10 in FIG. 14, and a drive device 43 that slides the first and second sliders 41 and 42. The drive device 43 is electrically connected to the ECU 20 and controlled by the ECU 20, similarly to the drive device 16 according to the first embodiment.

  The first and second sliders 41 and 42 are arranged side by side in the sliding direction. A driving device 43 is disposed between the first slider 41 and the second slider 42, and end portions of the first and second sliders 41 and 42 are inserted into the driving device 43. The drive device 43 can slide the first and second sliders 41, 42 in opposite directions. When the first and second sliders 41, 42 are slid by the drive device 43, the expansion / contraction mechanism 38 expands / contracts. Will do.

  Further, one end portions of the first and second link members 39 and 40 are rotatably connected to the same position in the one end portion of the arm member 10. The other end of the first link member 39 is rotatably connected to the first slider 41, and the other end of the second link member 40 is rotatably connected to the second slider 42. That is, as shown in FIG. 14, the expansion / contraction mechanism 38 and the first and second link members 39 and 40 form a triangle having the expansion / contraction mechanism 38 as a base.

  In the present embodiment, when the compression ratio of the internal combustion engine 1 is changed, the first and second sliders 41 and 42 are slid in opposite directions by the driving device 43. That is, the expansion / contraction mechanism 38 is expanded / contracted. When the expansion / contraction mechanism 38 expands / contracts, one end of the arm member 10 is pushed up or pulled down by the first and second link members 39 and 40. As a result, the arm member 10 swings around the connection portion with the output shaft 9.

  As described above, even with the configuration according to the present embodiment, the arm member 10 can be swung around the connection portion with the output shaft 9 by expanding and contracting the expansion and contraction mechanism 38, as in the first embodiment. Thereby, the compression ratio of the internal combustion engine 1 can be changed.

  In the present embodiment, the one end portions of the first and second link members 39 and 40 may be connected to the crank side of the arm member 10 instead of the one end portion of the arm member 10.

In the above-described first to eighth embodiments, the case where the present invention is applied to an in-line four-cylinder engine has been described. However, the present invention may be applied to a V-type engine. In the case of the V-type engine, the connecting rod 6 connected to the piston 3 in the cylinder 2 of both banks is connected to the crankshaft 8 in a V-shape. Here, in the present invention, when changing the compression ratio, the crankshaft 8 moves on an arc centered on the output shaft 9, but by making the arm member 10 relatively long,
The radius of the arc serving as the movement path of the crankshaft 8 can be made relatively long. The longer the radius of the arc, the smaller the axial displacement of the arm member 10 when the crankshaft 8 is moved. Therefore, even in the V-type engine, the compression ratio in both banks can be changed in substantially the same manner by making the arm member 10 relatively long.

1 is a diagram showing a schematic configuration of a variable compression ratio internal combustion engine according to Embodiment 1 of the present invention. The 1st figure at the time of seeing the crankshaft which concerns on Example 1 of this invention from upper direction. Fig.3 (a) is a figure which shows the state of the arm member at the time of high compression ratio. FIG.3 (b) is a figure which shows the state of the arm member at the time of a low compression ratio. The 2nd figure at the time of seeing a crankshaft from the top in Example 1 of the present invention. The figure which shows schematic structure of the arm member and 2nd slider which concern on the 1st modification of Example 1 of this invention. The figure which shows schematic structure of the arm member and 2nd slider which concern on the 2nd modification of Example 1 of this invention. The figure which shows schematic structure of the arm member and swing apparatus which concern on Example 2 of this invention. The figure which shows schematic structure of the arm member and rocking | fluctuation apparatus which concern on Example 3 of this invention. The figure which shows schematic structure of the arm member which concerns on Example 4 of this invention, and a rocking device. The figure which shows schematic structure of the arm member and rocking | fluctuation apparatus which concern on Example 5 of this invention. The figure which shows schematic structure of the arm member and rocking | fluctuation apparatus which concern on Example 6 of this invention. The figure which shows schematic structure of the arm member which concerns on Example 7 of this invention. The figure which shows schematic structure of the rocking | fluctuation apparatus which concerns on Example 7 of this invention. The figure which shows schematic structure of the arm member and swing apparatus which concern on Example 8 of this invention.

Explanation of symbols

1. Variable compression ratio internal combustion engine (internal combustion engine)
2 ... Cylinder 3 ... Piston 4 ... Combustion chamber 5 ... Crankcase 6 ... Connecting rod 8 ... Crankshaft 9 ... Output shaft 10 ... Arm member (first arm member)
10a · · inclined surface 10b · · inclined surface 10c · · link mounting portion 10d · · end surface 10e · · connecting rod connection portion 11 · · crank side gear 12 · · output side gear 13 · · swinging device 14 · · first slider 14a ··· projection 15 ··· second slider 15a · · projection 15b · · inclined surface 16 · · drive device 20 · · ECU
21.. Arm side protrusion 21 a.. Inclined surface 22.. Slider 22 c.. Link attachment part 24... Link member 25... Stopper 26... Second arm member 27. · Cam 30 · · Drive device 31 · · Gear 32 · · Drive device 33 · · Slant hair member 34 · · Vibration device 35 · · Hole 36 · · Insertion member 37 · · Drive device 38 · · Telescopic mechanism 39 · · One link member 40, second link member 41, first slider 42, second slider 43, drive device

Claims (11)

A variable compression ratio internal combustion engine in which the compression ratio is changed by changing the volume of the combustion chamber,
A crankshaft connected to the piston via a link member and rotating in conjunction with the reciprocating motion of the piston;
An output shaft disposed substantially parallel to the crankshaft and rotatably supported;
Rotation transmission means for rotating the output shaft by transmitting rotation of the crankshaft to the output shaft;
Shaft moving means for moving the crankshaft as a movement path on an arc centered on the output shaft, and
The variable compression is characterized in that the crankshaft is moved by the shaft moving means to move the positions of the top dead center and the bottom dead center of the piston with respect to the cylinder, thereby changing the volume of the combustion chamber. Specific internal combustion engine.   The variable compression ratio internal combustion engine according to claim 1, wherein the crankshaft and the output shaft are installed in a crankcase connected to the cylinder. The shaft moving means is
An arm member having the crankshaft rotatably connected to one end and an output shaft rotatably connected to the other end;
Arm swinging means for swinging the arm member around the connecting portion of the arm member with the output shaft;
2. The variable compression ratio internal combustion engine according to claim 1, wherein the arm shaft is swung by the arm rocking means to move the crankshaft along a circular arc centered on the output shaft. 3. . An inclined surface inclined with respect to a plane including the central axis of the crankshaft and the central axis of the output shaft is provided at a portion closer to the crankshaft than the connection portion with the output shaft of the arm member. Formed,
The arm swinging means is
Protrusions that are in contact with the inclined surface formed on the arm member, and a slide member that slides in a direction intersecting with a plane including the inclined surface,
4. The slide member is slid while contacting the inclined surface and the protrusion, thereby pressing the arm member by the protrusion and thereby swinging the arm member. The variable compression ratio internal combustion engine described. The protrusion is a slider-side protrusion,
A plurality of arm side protrusions in which the inclined surface is formed are provided in a portion of the arm member that is closer to the connection portion with the crankshaft than a connection portion with the output shaft,
5. The variable compression ratio internal combustion engine according to claim 4, wherein a plurality of the slider side protrusions are provided on the slide member so as to contact each of the inclined surfaces formed on the arm side protrusions. organ. The arm swinging means is
An arm link member having one end rotatably connected to a portion closer to the connecting portion with the crankshaft than a connecting portion with the output shaft in the arm member;
A slide member rotatably connected to the other end of the link member for the arm,
4. The arm member is pressed by the arm link member by sliding the slide member while swinging the arm link member, thereby swinging the arm member. The variable compression ratio internal combustion engine described. The arm member is a first arm member,
The arm swinging means is
A second arm member whose one end is rotatably and slidably connected to a portion of the first arm member that is closer to the connecting portion to the crankshaft than the connecting portion to the output shaft;
A support member that rotatably supports the middle of the second arm member,
By moving the other end portion of the second arm member, the second arm member is swung around a portion supported by the support member, and thereby the first arm member is swung. The variable compression ratio internal combustion engine according to claim 3, The arm swinging means is
A cam disposed so as to be in contact with a portion on the connection portion side with the crankshaft rather than a connection portion with the output shaft in the arm member;
The variable compression ratio internal combustion engine according to claim 3, wherein the arm member is swung by rotating the cam. The arm swinging means is
A gear installed so as to be in contact with a portion of the connecting portion side with the crankshaft rather than a connecting portion with the output shaft in the arm member;
The arm member is formed with an uneven portion that meshes with the gear,
4. The variable compression ratio internal combustion engine according to claim 3, wherein the arm swinging means swings the arm member by driving the gear. The arm swinging means is
A plurality of bevels that are inclined in the same direction in a direction intersecting a plane including the center axis of the crankshaft and the center axis of the output shaft are provided on the wall surface, and the output of the arm member An inclined hair member installed so that an end of the inclined hair comes into contact with a portion closer to the connecting portion with the crankshaft than a connecting portion with the shaft;
A vibration device that vibrates the oblique hair member in the swing direction of the arm member,
The variable compression ratio internal combustion engine according to claim 3, wherein the arm member is swung by vibrating the slanted hair member by the vibration device. The connecting portion of the arm member with the output shaft is provided with a hole in which a spiral groove is formed on the wall surface and the center axis is the same as the output shaft,
The arm swinging means is
A convex portion that is inserted into the hole provided in the arm member and that fits into the groove is formed on a side surface;
4. The variable compression ratio internal combustion engine according to claim 3, wherein the arm member is swung by moving the insertion member in the axial direction without rotating in the hole.

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