JP2000064866A - Variable compression ratio device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To communication control an oil pressure supply path supplying an oil pressure for increasing friction when compression ratio is changed without particularly providing a control valve. SOLUTION: An oil pressure supply path 31, inserting an eccentric bearing 21 between a large end part 2 of a connecting rod and a crank pin 12 for changing compression ratio of an internal combustion engine, so as to supply an oil pressure for increasing friction between the connecting rod 1 and the eccentric bearing 21 when the compression ratio is changed by rotating the eccentric bearing 21 relating to the crank pin 12, and supplying the oil pressure for increasing friction, is communication controlled by changing of a relative rotational position between the eccentric bearing 21 and the crank pin 12 according to rotation of a crankshaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable compression ratio device for an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, in order to change a compression ratio of an internal combustion engine, an eccentric bearing is inserted between a large end portion of a connecting rod and a crank pin and the compression ratio is changed by rotating the eccentric bearing with respect to the connecting rod. There is known a variable compression ratio device for an internal combustion engine which supplies hydraulic pressure to increase friction between a crank pin and an eccentric bearing. An example of this type of variable compression ratio device for an internal combustion engine is disclosed in Japanese Patent Application Laid-Open No. 6-241058.

FIG. 17 is a partial sectional side view of a conventional variable compression ratio device for an internal combustion engine. In FIG. 17, 401 is a connecting rod, 402 is a large end portion of the connecting rod, 411 is a crank shaft, 412 is a crank pin, 413 is a crank arm, and 414 is a crank journal. 421
Is an eccentric bearing inserted between the large end 402 of the connecting rod and the crank pin 412 to change the compression ratio of the internal combustion engine. Reference numeral 431 is a lock pin 432 for fixing the connecting rod 401 and the eccentric bearing 421.
Is a hydraulic pressure supply path for driving the lock pin 431. 441 is an eccentric bearing 4 with respect to the connecting rod 401.
Actuator 441 actuated to increase the friction between crank pin 412 (specifically crank arm 413) and eccentric bearing 421 when changing the compression ratio by rotating 21. Reference numeral 442 is a hydraulic pressure supply passage for supplying hydraulic pressure to operate the actuator 441, and 443 is a control valve for controlling communication of the hydraulic pressure supply passage 442.

As shown in FIG. 17, a conventional variable compression ratio device for an internal combustion engine increases friction between a crank pin and an eccentric bearing by controlling connection or disconnection of a hydraulic pressure supply passage by switching control valves. Whether or not to do so can be controlled.

[0005]

By the way, the connecting rod 401, the crank pin 412 and the eccentric bearing 421 are provided.
The relative rotational positions of the crankshafts 411 change as the crankshaft 411 rotates. Therefore, it is conceivable to substitute the control valve 443 with the connecting rod 401, the crank pin 412 and the eccentric bearing 421. Nevertheless, the conventional variable compression ratio device for an internal combustion engine has a control valve 443.
Was specially set up. Therefore, the cost of the entire apparatus is increased, and the control circuit of the apparatus for controlling the control valve 443 and the like is complicated.

In view of the above-mentioned problems, the present invention relates to an internal combustion engine capable of communicating and controlling a hydraulic pressure supply passage for supplying hydraulic pressure to increase friction at the time of changing the compression ratio, without the need to specially provide a control valve. An object is to provide a variable compression ratio device.

[0007]

According to the invention described in claim 1, an eccentric bearing is inserted between the large end portion of the connecting rod and the crank pin in order to change the compression ratio of the internal combustion engine, and the crank pin is provided. On the other hand, when the compression ratio is changed by rotating the eccentric bearing, a variable compression ratio device for an internal combustion engine is provided, which supplies hydraulic pressure to increase friction between the connecting rod and the eccentric bearing. A variable internal combustion engine characterized in that a hydraulic pressure supply passage for supplying hydraulic pressure to increase friction is controlled in communication by a change in relative rotational position between the eccentric bearing and the crank pin due to rotation of a crankshaft. A compression ratio device is provided.

In the variable compression ratio device for an internal combustion engine according to the first aspect of the present invention, the hydraulic supply path for supplying hydraulic pressure to increase friction changes the relative rotational position of the eccentric bearing and the crank pin due to the rotation of the crankshaft. The communication is controlled by. Therefore, it is not necessary to specially provide a control valve for controlling the communication of the hydraulic pressure supply path, and therefore, it is possible to avoid the cost increase of the device and the complication of the control circuit, which are associated with the special provision of the control valve.

According to the second aspect of the invention, the flange provided on the eccentric bearing is pressed against the axial end surface of the connecting rod by the hydraulic pressure supplied through the hydraulic pressure supply passage, whereby the connecting rod is pressed. The variable compression ratio device for an internal combustion engine according to claim 1, wherein friction between the eccentric bearing and the eccentric bearing is increased.

In the variable compression ratio device for an internal combustion engine according to a second aspect of the present invention, the flange provided on the eccentric bearing is pressed against the axial end surface of the connecting rod by the hydraulic pressure supplied through the hydraulic pressure supply passage, whereby the connecting rod is connected. Increases the friction between the eccentric bearing and the eccentric bearing. Therefore, by changing the radial length of the flange, the magnitude of friction between the connecting rod and the eccentric bearing can be changed to a desired magnitude.

According to the third aspect of the present invention, the lock pin for fixing the crank pin and the eccentric bearing is released before increasing the friction between the connecting rod and the eccentric bearing, and The variable compression of an internal combustion engine according to claim 1, wherein the crank pin and the eccentric bearing are fixed by the lock pin when the relative rotational position of the eccentric bearing and the crank pin changes to a predetermined position. A ratio device is provided.

In the variable compression ratio device for an internal combustion engine according to a third aspect, when the relative rotational position of the eccentric bearing and the crank pin changes to a predetermined position, the lock pin fixes the crank pin and the eccentric bearing. The compression ratio can be fixed reliably.

According to a fourth aspect of the present invention, a part of the hydraulic pressure supply passage is a circumferential groove formed between the crank pin and the eccentric bearing and extending in the circumferential direction. A variable compression ratio device for an internal combustion engine according to claim 1 is provided.

In the variable compression ratio device for an internal combustion engine according to a fourth aspect, since a part of the hydraulic pressure supply passage is a circumferential groove formed between the crank pin and the eccentric bearing, the hydraulic pressure is increased. The hydraulic pressure supplied through the supply passage can increase the friction between the connecting rod and the eccentric bearing, and can lubricate between the crankpin and the eccentric bearing.

According to the fifth aspect of the present invention, when the hydraulic pressure supply passage is not communicated for supplying hydraulic pressure for increasing friction between the connecting rod and the eccentric bearing, the hydraulic pressure supply passage is provided. The hydraulic pressure supplied via
The variable compression ratio device for an internal combustion engine according to claim 1, wherein the variable compression ratio device is used for lubricating between the connecting rod and the eccentric bearing.

According to a fifth aspect of the present invention, in the variable compression ratio device for an internal combustion engine, when the hydraulic pressure supply passage is not communicated to supply hydraulic pressure for increasing friction between the connecting rod and the eccentric bearing, the hydraulic pressure supply passage is provided. The hydraulic pressure supplied via
Used to lubricate between the connecting rod and the eccentric bearing. Therefore, the hydraulic pressure supplied through the hydraulic pressure supply passage can be effectively used not only when communicating but also when not communicating.

According to the invention described in claim 6, an eccentric bearing is inserted between the large end portion of the connecting rod and the crank pin in order to change the compression ratio of the internal combustion engine, and the eccentric bearing is rotated with respect to the connecting rod. In the variable compression ratio device of the internal combustion engine, which is configured to supply the hydraulic pressure to increase the friction between the crank pin and the eccentric bearing when the compression ratio is changed, the hydraulic pressure is increased to increase the friction. There is provided a variable compression ratio device for an internal combustion engine, wherein a hydraulic pressure supply path to be supplied is communication-controlled by a change in relative rotational position between the eccentric bearing and the connecting rod due to rotation of a crankshaft.

In the variable compression ratio device for an internal combustion engine according to a sixth aspect, the hydraulic supply path for supplying hydraulic pressure to increase friction changes the relative rotational position of the eccentric bearing and the connecting rod with the rotation of the crankshaft. The communication is controlled by. Therefore, it is not necessary to specially provide a control valve for controlling the communication of the hydraulic pressure supply path, and therefore, it is possible to avoid the cost increase of the device and the complication of the control circuit, which are associated with the special provision of the control valve.

According to the invention as set forth in claim 7, the flange provided on the eccentric bearing is pressed against the axial end surface of the crank arm by the hydraulic pressure supplied through the hydraulic pressure supply passage, whereby the crank 7. The variable compression ratio device for an internal combustion engine according to claim 6, wherein the friction between the pin and the eccentric bearing is increased.

According to another aspect of the variable compression ratio device for an internal combustion engine of the present invention, the flange provided on the eccentric bearing is pressed against the axial end surface of the crank arm by the hydraulic pressure supplied through the hydraulic pressure supply passage. Increases friction between the crankpin and the eccentric bearing. Therefore, by changing the radial length of the flange, the magnitude of friction between the crankpin and the eccentric bearing can be changed to a desired magnitude.

According to the invention described in claim 8, the lock pin for fixing the connecting rod and the eccentric bearing is released before increasing the friction between the crank pin and the eccentric bearing, and 9. The variable compression for an internal combustion engine according to claim 8, wherein the connecting rod and the eccentric bearing are fixed by the lock pin when the relative rotational position of the eccentric bearing and the connecting rod changes to a predetermined position. A ratio device is provided.

In the variable compression ratio device for an internal combustion engine according to the eighth aspect, when the relative rotational position between the eccentric bearing and the connecting rod is changed to a predetermined position, the connecting pin and the eccentric bearing are fixed by the lock pin. The compression ratio can be fixed reliably.

According to a ninth aspect of the invention, a part of the hydraulic pressure supply passage is a circumferential groove formed between the connecting rod and the eccentric bearing and extending in the circumferential direction. A variable compression ratio device for an internal combustion engine according to claim 6 is provided.

In the variable compression ratio device for an internal combustion engine according to a ninth aspect, since a part of the hydraulic pressure supply passage is a circumferential groove formed between the connecting rod and the eccentric bearing and extending in the circumferential direction, the hydraulic pressure is increased. The hydraulic pressure supplied through the supply passage can increase the friction between the crank pin and the eccentric bearing, and can lubricate the connecting rod and the eccentric bearing.

According to the tenth aspect of the present invention, when the hydraulic pressure supply passage is not connected to supply hydraulic pressure for increasing friction between the crankpin and the eccentric bearing, the hydraulic pressure supply passage is not connected. The variable compression ratio device for an internal combustion engine according to claim 6, wherein the hydraulic pressure supplied via the is used to lubricate between the crank pin and the eccentric bearing.

In the variable compression ratio device for an internal combustion engine according to the tenth aspect, when the hydraulic pressure supply passage is not communicated to supply hydraulic pressure for increasing friction between the crankpin and the eccentric bearing, the hydraulic pressure supply passage is provided. The hydraulic pressure supplied through is used to lubricate between the crankpin and the eccentric bearing. Therefore, the hydraulic pressure supplied through the hydraulic pressure supply passage can be effectively used not only when communicating but also when not communicating.

According to the invention described in claim 11, an eccentric bearing is inserted between the small end portion of the connecting rod and the piston pin to change the compression ratio of the internal combustion engine, and the eccentric bearing is attached to the piston pin. A variable compression ratio device for an internal combustion engine, which is adapted to supply hydraulic pressure to increase friction between the connecting rod and the eccentric bearing when the compression ratio is changed by rotating, and to increase friction. There is provided a variable compression ratio device for an internal combustion engine, characterized in that a hydraulic pressure supply path for supplying hydraulic pressure is controlled in communication by a change in relative rotational position between the eccentric bearing and the piston pin due to rotation of a crankshaft. It

In the variable compression ratio device for an internal combustion engine according to the eleventh aspect of the present invention, the hydraulic supply path for supplying the hydraulic pressure to increase the friction changes the relative rotational position between the eccentric bearing and the piston pin as the crankshaft rotates. The communication is controlled by. Therefore, it is not necessary to specially provide a control valve for controlling the communication of the hydraulic pressure supply path, and therefore, it is possible to avoid the cost increase of the device and the complication of the control circuit, which are associated with the special provision of the control valve.

According to the twelfth aspect of the present invention, the flange provided on the eccentric bearing is pressed against the axial end surface of the connecting rod by the hydraulic pressure supplied through the hydraulic pressure supply passage, whereby the connecting rod is pressed. The variable compression ratio device for an internal combustion engine according to claim 11, wherein friction between the eccentric bearing and the eccentric bearing is increased.

A variable compression ratio device for an internal combustion engine according to a twelfth aspect of the present invention uses the hydraulic pressure supplied through the hydraulic pressure supply passage to
By pressing the flange provided on the eccentric bearing against the axial end surface of the connecting rod, the friction between the connecting rod and the eccentric bearing is increased. Therefore, by changing the radial length of the flange, the magnitude of friction between the connecting rod and the eccentric bearing can be changed to a desired magnitude.

According to the thirteenth aspect of the present invention, the lock pin for fixing the piston pin and the eccentric bearing is released before increasing the friction between the connecting rod and the eccentric bearing, The variable compression of an internal combustion engine according to claim 11, wherein the piston pin and the eccentric bearing are fixed by the lock pin when the relative rotational position of the eccentric bearing and the piston pin changes to a predetermined position. A ratio device is provided.

In the variable compression ratio device for an internal combustion engine according to a thirteenth aspect, when the relative rotational position of the eccentric bearing and the piston pin changes to a predetermined position, the lock pin fixes the piston pin and the eccentric bearing.
The compression ratio can be fixed reliably.

According to a fourteenth aspect of the present invention, a part of the hydraulic pressure supply passage is a circumferential groove formed between the piston pin and the eccentric bearing and extending in the circumferential direction. A variable compression ratio device for an internal combustion engine according to claim 11 is provided.

In the variable compression ratio device for an internal combustion engine according to a fourteenth aspect, since a part of the hydraulic pressure supply passage is a circumferential groove formed between the piston pin and the eccentric bearing and extending in the circumferential direction, the hydraulic pressure is increased. By the hydraulic pressure supplied through the supply path,
It is possible to increase the friction between the connecting rod and the eccentric bearing and to lubricate between the piston pin and the eccentric bearing.

According to a fifteenth aspect of the present invention, when the hydraulic pressure supply passage is not communicated for supplying hydraulic pressure for increasing friction between the connecting rod and the eccentric bearing, the hydraulic pressure supply passage is provided. The variable compression ratio device for an internal combustion engine according to claim 11, wherein the hydraulic pressure supplied via the is used to lubricate between the connecting rod and the eccentric bearing.

In the variable compression ratio device for an internal combustion engine according to claim 15, the hydraulic pressure supply passage is provided when the hydraulic pressure supply passage is not communicated to supply hydraulic pressure for increasing friction between the connecting rod and the eccentric bearing. The hydraulic pressure supplied through is used to lubricate between the connecting rod and the eccentric bearing. Therefore, the hydraulic pressure supplied through the hydraulic pressure supply passage can be effectively used not only when communicating but also when not communicating.

According to the sixteenth aspect of the present invention, an eccentric bearing is inserted between the small end portion of the connecting rod and the piston pin to change the compression ratio of the internal combustion engine, and the eccentric bearing is rotated with respect to the connecting rod. In the variable compression ratio device of the internal combustion engine, which is configured to supply the hydraulic pressure to increase the friction between the piston pin and the eccentric bearing when changing the compression ratio by changing the compression ratio, the hydraulic pressure is increased to increase the friction. There is provided a variable compression ratio device for an internal combustion engine, wherein a hydraulic pressure supply path to be supplied is communication-controlled by a change in relative rotational position between the eccentric bearing and the connecting rod due to rotation of a crankshaft.

In the variable compression ratio device for an internal combustion engine according to the sixteenth aspect, the hydraulic supply path for supplying the hydraulic pressure to increase the friction changes the relative rotational position between the eccentric bearing and the connecting rod as the crankshaft rotates. The communication is controlled by. Therefore, it is not necessary to specially provide a control valve for controlling the communication of the hydraulic pressure supply path, and therefore, it is possible to avoid the cost increase of the device and the complication of the control circuit, which are associated with the special provision of the control valve.

According to the seventeenth aspect of the invention, the eccentric bearing flange provided on the eccentric bearing is pressed against the piston pin flange provided on the piston pin by the hydraulic pressure supplied through the hydraulic pressure supply passage. The friction between the piston pin and the eccentric bearing is increased by doing so.
A variable compression ratio device for an internal combustion engine is provided.

A variable compression ratio device for an internal combustion engine according to a seventeenth aspect of the present invention uses the hydraulic pressure supplied through the hydraulic pressure supply passage to
The friction between the piston pin and the eccentric bearing is increased by pressing the eccentric bearing flange provided on the eccentric bearing against the piston pin flange provided on the piston pin. Therefore, by changing the radial length of the eccentric bearing flange, the magnitude of friction between the piston pin and the eccentric bearing can be changed to a desired magnitude.

According to the eighteenth aspect of the present invention, the lock pin for fixing the connecting rod and the eccentric bearing is released before increasing the friction between the piston pin and the eccentric bearing, The variable compression of the internal combustion engine according to claim 16, wherein the connecting rod and the eccentric bearing are fixed by the lock pin when the relative rotational position of the eccentric bearing and the connecting rod changes to a predetermined position. A ratio device is provided.

In the variable compression ratio device for an internal combustion engine according to the eighteenth aspect, when the relative rotational position between the eccentric bearing and the connecting rod changes to a predetermined position, the connecting pin and the eccentric bearing are fixed by the lock pin. The compression ratio can be fixed reliably.

According to a nineteenth aspect of the present invention, a part of the hydraulic pressure supply passage is a circumferential groove formed between the connecting rod and the eccentric bearing and extending in the circumferential direction. A variable compression ratio device for an internal combustion engine according to claim 16 is provided.

In the variable compression ratio device for an internal combustion engine according to claim 19, since a part of the hydraulic pressure supply passage is a circumferential groove formed between the connecting rod and the eccentric bearing and extending in the circumferential direction, the hydraulic pressure is increased. The hydraulic pressure supplied through the supply passage can increase the friction between the piston pin and the eccentric bearing and lubricate the connecting rod and the eccentric bearing.

According to the twentieth aspect of the invention, when the hydraulic pressure supply passage is not communicated to supply hydraulic pressure for increasing the friction between the piston pin and the eccentric bearing, the hydraulic pressure supply passage is provided. The variable compression ratio device for an internal combustion engine according to claim 16, wherein the hydraulic pressure supplied via the is used to lubricate between the piston pin and the eccentric bearing.

In the variable compression ratio device for an internal combustion engine according to claim 20, when the hydraulic pressure supply passage is not communicated to supply hydraulic pressure for increasing friction between the piston pin and the eccentric bearing, the hydraulic pressure supply passage is provided. The hydraulic pressure supplied via is used to lubricate between the piston pin and the eccentric bearing. Therefore, the hydraulic pressure supplied through the hydraulic pressure supply passage can be effectively used not only when communicating but also when not communicating.

[0047]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a partially sectional side view of a first embodiment of a variable compression ratio device for an internal combustion engine of the present invention, FIG. 2 is an enlarged view of a part of FIG. 1, and FIGS. 3 to 9 are connecting rods and cranks. FIG. 4 is a partial axial sectional view showing a relative rotational positional relationship between a pin and an eccentric bearing over time. 1 to 9, 1 is a connecting rod, 2 is a large end of the connecting rod, 11 is a crank shaft, 12 is a crank pin, 13 is a crank arm, and 14 is a crank journal. 21 is the large end 2 of the connecting rod for changing the compression ratio of the internal combustion engine.
An eccentric bearing inserted between the crankshaft 12 and the crankpin 12, and a flange 22 provided on the eccentric bearing 21. Reference numeral 23 is a lock pin engagement hole formed in the inner circumference of the eccentric bearing 21, and 24 is a lubricating pin that can communicate with the crankshaft hydraulic pressure supply passage 31 to lubricate between the eccentric bearing 21 and the large end 2 of the connecting rod. It is a hydraulic supply path.
31 is an oil pump (not shown) to the crank pin 12
Crankshaft hydraulic supply path extending to the outer circumference of
Reference numeral 2 denotes a circumferential groove-shaped hydraulic supply passage formed in the inner circumference of the eccentric bearing 21 and extending in the circumferential direction, and 33 denotes the eccentric bearing 21.
Is an axial hydraulic pressure supply passage that is formed on the inner circumference of and extends axially from the circumferential groove hydraulic pressure supply passage 32. Reference numeral 41 is a lock pin that can be engaged with the lock pin engagement hole 23 for fixing the crank pin 12 and the eccentric bearing 21;
Is a lock pin spring for urging the lock pin 41 toward the lock pin engagement hole 23 in order to fix the compression ratio to high compression. Reference numeral 43 denotes a high compression engaging end which is engaged in the lock pin engaging hole 23 when the compression ratio is high compression, and 44 is a low engaging end which is engaged in the lock pin engaging hole 23 when the compression ratio is low compression. The compression engagement end 45 is a lock pin hydraulic pressure supply passage for supplying hydraulic pressure to urge the lock pin 41 toward the lock pin engagement hole 23 in order to fix the compression ratio to low compression.

As shown in FIG. 3, when the compression ratio is fixed to high compression, no oil pressure is supplied to the lock pin 41 through the lock pin oil pressure supply passage 45, and therefore the lock pin 41 is not supplied. The high compression engagement end of the lock pin 41 is engaged with the engagement hole 23, and the crank pin 12 and the eccentric bearing 21 are fixed so that their relative rotational positions do not change. In addition, the crankshaft hydraulic pressure supply passage 31
Communicates between the connecting rod 1 and the eccentric bearing 21 via a lubricating oil pressure supply passage 24.
And the eccentric bearing 21 are lubricated. During rotation of the crankshaft, the crankpin 12 and the eccentric bearing 2
1 does not slide, but the eccentric bearing 21 and the connecting rod 1 slide.

When the compression ratio is changed from high compression to low compression, first, as shown in FIG. 4, the hydraulic pressure is supplied to the lock pin 41 through the lock pin hydraulic pressure supply passage 45, and the crank pin 12 and the eccentricity are provided. The fixation with the bearing 21 is released. Therefore, not only the eccentric bearing 21 and the connecting rod 1 but also the crank pin 12 and the eccentric bearing 21
Also becomes slidable as the crankshaft rotates.

As shown in FIG. 5, when the crankshaft rotates, the crankpin 12 and the eccentric bearing 21 slide, and the relative rotational position between the crankpin 12 and the eccentric bearing 21 changes. As a result, the crankshaft hydraulic pressure supply passage 31 is not communicated with the lubrication hydraulic pressure supply passage 24, but is instead communicated with the circumferential groove hydraulic supply passage 32. As shown in detail in FIG. 2, the circumferential groove-shaped hydraulic pressure supply passage 32 is located on the right side of the flange 22 via the axial hydraulic pressure supply passage 33 (FIG. 2).
It communicates with the end face. Therefore, the hydraulic pressure supply paths 31, 3
The hydraulic pressure supplied via 2 and 33 presses the eccentric bearing 21 to the left (FIG. 2), that is, the flange 22 to the axial end surface of the connecting rod 1. As a result, the friction between the connecting rod 1 and the eccentric bearing 21 is increased. On the other hand, since the circumferential groove-shaped hydraulic pressure supply passage 32 extends in the circumferential direction and is formed between the crank pin 12 and the eccentric bearing 21, the crank pin 12 and the eccentric bearing 21 are lubricated. Therefore, as shown in FIGS. 6 and 7, the crank pin 12 rotates with respect to the eccentric bearing 21 in a state where large friction is generated between the connecting rod 1 and the eccentric bearing 21 during rotation of the crank shaft. To do.

When the relative rotational position between the eccentric bearing 21 and the crank pin 12 is in the state shown in FIG. 7, the lock pin 41 has the lock pin hydraulic pressure supply passage 4 as described above.
Since the hydraulic pressure is supplied via 5, the low compression engagement end 44 of the lock pin 41 engages with the lock pin engagement hole 23 as shown in FIG. As a result, the crank pin 12 and the eccentric bearing 21 are fixed so that the relative rotational position does not change, and the compression ratio is fixed to low compression. Further, similarly to the state shown in FIG. 3, the crankshaft hydraulic pressure supply passage 31 is connected to the connecting rod 1 via the lubricating hydraulic pressure supply passage 24.
And the eccentric bearing 21 communicate with each other, and the connecting rod 1 and the eccentric bearing 21 are lubricated. As shown in FIGS. 8 and 9, when the compression ratio is fixed, the crankpin 12 and the eccentric bearing 21 do not slide but the eccentric bearing 21 and the connecting rod 1 slide during the rotation of the crankshaft. .

As described above, according to the present embodiment, the hydraulic pressure supply passages 31, 32 and 33 for supplying hydraulic pressure to increase the friction between the connecting rod 1 and the eccentric bearing 21.
However, the eccentric bearing 21 accompanying the rotation of the crankshaft
The communication is controlled by a change in the relative rotational position between the crank pin 12 and the crank pin 12. Therefore, unlike the case of the conventional variable compression ratio device for an internal combustion engine shown in FIG. 17, it is not necessary to specially provide a control valve for controlling the communication of the hydraulic pressure supply passage. Therefore, it is possible to avoid the cost increase of the device and the complication of the control circuit, which are associated with the special provision of the control valve.

Further, as described above, according to the present embodiment, the flange 22 provided on the eccentric bearing 21 is attached to the axial end surface of the connecting rod 1 by the hydraulic pressure supplied through the hydraulic pressure supply passages 31, 32 and 33. By pressing, friction between the connecting rod 1 and the eccentric bearing 21 is increased. Therefore, by changing the design of the radial length of the flange 22, the magnitude of friction between the connecting rod 1 and the eccentric bearing 21 can be changed to a desired magnitude. Further, as shown in FIGS. 3 and 8, when the relative rotational position between the eccentric bearing 21 and the crank pin 12 changes to a predetermined position, the lock pin 41 fixes the crank pin 12 and the eccentric bearing 21. Therefore, the compression ratio can be reliably fixed to high compression or low compression.

Further, as described above, according to this embodiment, as shown in FIGS. 1 and 2, the hydraulic pressure supply passages 31, 3 are provided.
Since the entire eccentric bearing 21 is pushed by the hydraulic pressure supplied via 2 and 33, the actuator provided in the eccentric bearing is hydraulically operated.
The configuration of the eccentric bearing can be simplified as compared with the conventional case shown in FIG.

Further, as described above, according to this embodiment, the hydraulic pressure supply passage 32 is the circumferential groove formed between the crank pin 12 and the eccentric bearing 21 and extending in the circumferential direction. The hydraulic pressure supplied through the passage 32 can increase the friction between the connecting rod 1 and the eccentric bearing 21 and lubricate the crank pin 12 and the eccentric bearing 21.

Further, as described above, according to the present embodiment, the crankshaft hydraulic pressure supply passage 31 has the connecting rod 1
When not communicating with the circumferential groove hydraulic supply passage 32 and the axial hydraulic supply passage 33 for supplying hydraulic pressure for increasing the friction between the eccentric bearing 21 and the eccentric bearing 21, the lubricating hydraulic supply passage 2 is provided.
The hydraulic pressure supplied via 4 is used to lubricate between the connecting rod 1 and the eccentric bearing 21. Therefore, the hydraulic pressure supplied through the crankshaft hydraulic pressure supply passage 31 can be effectively used not only when it is communicated with the circumferential groove hydraulic supply passage 32 and the axial hydraulic pressure supply passage 33, but also when it is not communicated. it can.

In order to explain the present embodiment, FIGS.
Although only the connecting rod 1, the eccentric bearing 21, and the crank pin 12 corresponding to one cylinder are shown in FIG. 9, it goes without saying that the variable compression ratio device for an internal combustion engine of the present embodiment is also applicable to a multi-cylinder internal combustion engine. Applicable.

FIG. 10 is a partial sectional side view of a second embodiment of the variable compression ratio device for an internal combustion engine of the present invention, and FIG. 11 is FIG.
FIG. 12 is an enlarged partial enlarged view of FIG. 12, and FIG. 12 is an axial partial cross-sectional view showing the relative rotational positional relationship among the connecting rod, the crank pin, and the eccentric bearing while the compression ratio is being changed. Figure 10
In FIG. 12, 101 is a connecting rod, 102 is a large end of the connecting rod, 111 is a crank shaft, 112 is a crank pin, 113 is a crank arm, and 114 is a crank journal. Reference numeral 121 designates the large end portion 102 of the connecting rod and the crank pin 1 for changing the compression ratio of the internal combustion engine.
An eccentric bearing 121 is inserted between the eccentric bearing 121 and the eccentric bearing 121, and a flange 122 is provided on the eccentric bearing 121. 123
Is a lock pin engaging hole formed in the flange 122 of the eccentric bearing 121, and 124 is a lubricating oil pressure that can communicate with the crankshaft oil pressure supply passage 131 to lubricate between the eccentric bearing 121 and the large end portion 102 of the connecting rod. It is a supply channel. Reference numeral 131 denotes an oil pressure supply passage extending from an oil pump (not shown) to the outer periphery of the eccentric bearing 121 via the crankshaft 111, the eccentric bearing 121, and the connecting rod 101, and 132 denotes the eccentric bearing 121.
A circumferential groove-shaped hydraulic pressure supply passage 133 formed on the outer circumference of the circumferential groove-shaped hydraulic supply passage 133 is formed on the outer circumference of the eccentric bearing 121 and extends axially from the circumferential groove-shaped hydraulic pressure supply passage 132. It is a road. 141 is a connecting rod 101
And a lock pin engaging hole 123 for fixing the eccentric bearing 121. Although not shown, the biasing means of the lock pin 141 is almost the same as that of the first embodiment.

When the compression ratio is fixed to a high compression, the lock pin 141 has the lock pin engaging hole 1 on the right side (FIG. 10).
23, the connecting rod 101 and the eccentric bearing 121 are fixed so that their relative rotational positions do not change. The hydraulic pressure supply path 131 is on the left side (FIG. 12).
Through the lubricating oil pressure supply passage 124 of the crank pin 11
2 communicates with the eccentric bearing 121, and the crank pin 112 and the eccentric bearing 121 are lubricated. During the rotation of the crankshaft, the connecting rod 101 and the eccentric bearing 121 do not slide, and the eccentric bearing 1
21 and the crank pin 112 slide.

When the compression ratio is changed from high compression to low compression, first, the lock pin 141 and the lock pin engaging hole 123 are
The engagement between the connecting rod 101 and the eccentric bearing 121 is released. Therefore, not only the eccentric bearing 121 and the crank pin 112 but also the connecting rod 101 and the eccentric bearing 121 can be slid along with the rotation of the crankshaft.

When the crankshaft rotates, the connecting rod 101 and the eccentric bearing 121 slide, and the relative rotational position between the connecting rod 101 and the eccentric bearing 121 changes. As a result, the hydraulic pressure supply passage 131 is not communicated with the lubrication hydraulic pressure supply passage 124, but is instead communicated with the circumferential groove hydraulic supply passage 132. As shown in detail in FIG.
The circumferential groove hydraulic pressure supply passage 132 communicates with an end surface on the left side (FIG. 11) of the flange 122 via an axial hydraulic pressure supply passage 133. Therefore, the hydraulic pressure supply paths 131, 132 and 13
The hydraulic pressure supplied via 3 presses the eccentric bearing 121 to the right side (FIG. 11), that is, the flange 122 to the crank arm 113. As a result, the crank pin 11
The friction between the two and the eccentric bearing 121 is increased.
On the other hand, since the circumferential groove-shaped hydraulic pressure supply passage 132 extends in the circumferential direction and is formed between the connecting rod 101 and the eccentric bearing 121, the connecting rod 101 and the eccentric bearing 121 are formed.
Is lubricated between and. Therefore, while the crankshaft is rotating, a large friction is generated between the crankpin 112 and the eccentric bearing 121, and the connecting rod 10
1 rotates with respect to the eccentric bearing 121.

When the lock pin 141 is engaged with the lock pin engagement hole 123 on the left side (FIG. 10), the connecting rod 101 and the eccentric bearing 121 are fixed so that their relative rotational positions do not change, and the compression ratio becomes low. Fixed. Also,
The hydraulic supply passage 131 is
Via the lubrication hydraulic supply passage 124, the crank pin 112
And the eccentric bearing 121 communicate with each other, and the crank pin 112 and the eccentric bearing 121 are lubricated. When the compression ratio is fixed, the connecting rod 101 and the eccentric bearing 121 do not slide but the eccentric bearing 121 and the crank pin 112 slide while the crankshaft rotates.

As described above, according to this embodiment, the hydraulic pressure supply passages 131 and 1 for supplying hydraulic pressure to increase the friction between the crank pin 112 and the eccentric bearing 121.
32 and 133 are controlled to communicate with each other by the change in the relative rotational position between the eccentric bearing 121 and the connecting rod 101 due to the rotation of the crankshaft. Therefore, unlike the case of the conventional variable compression ratio device for an internal combustion engine shown in FIG. 17, it is not necessary to specially provide a control valve for controlling the communication of the hydraulic pressure supply passage. Therefore, it is possible to avoid the cost increase of the device and the complication of the control circuit, which are associated with the special provision of the control valve.

Further, as described above, according to the present embodiment, the flange 122 provided on the eccentric bearing 121 is pressed against the crank arm 113 by the hydraulic pressure supplied through the hydraulic pressure supply passages 131, 132 and 133. The crank pin 112 and the eccentric bearing 121
The friction between and is increased. Therefore, the flange 122
By changing the design of the radial length of the, the magnitude of friction between the crank pin 112 and the eccentric bearing 121 can be changed to a desired magnitude. Further, when the relative rotational position between the eccentric bearing 121 and the connecting rod 101 changes to a predetermined position, the connecting pin 101 and the eccentric bearing 121 are fixed by the lock pin 141, so that the compression ratio can be ensured to be high compression or low compression. Can be fixed to.

Further, as described above, according to the present embodiment, as shown in FIGS.
Since the entire eccentric bearing 121 is pushed by the hydraulic pressure supplied via 1, 132 and 133, compared with the conventional case shown in FIG. 17 in which the actuator provided in the eccentric bearing is hydraulically operated. The structure of the eccentric bearing can be simplified.

As described above, according to this embodiment, the hydraulic pressure supply passage 132 is the circumferential groove formed between the connecting rod 101 and the eccentric bearing 121 and extending in the circumferential direction. The crank pin 112 and the eccentric bearing 121 are driven by the hydraulic pressure supplied via 132.
The friction between the connecting rod 101 and the eccentric bearing 121 can be increased while increasing the friction between the connecting rod 101 and the connecting rod 101.

Further, as described above, according to the present embodiment, the hydraulic pressure supply passage 131 supplies the hydraulic pressure for increasing the friction between the crank pin 112 and the eccentric bearing 121 to the circumferential groove hydraulic pressure supply. When not communicating with the passage 132 and the axial hydraulic supply passage 133, the lubricating hydraulic supply passage 12
The oil pressure supplied via 4 is used to lubricate between the crank pin 112 and the eccentric bearing 121. Therefore, the hydraulic pressure supplied via the hydraulic pressure supply passage 131 is changed to the circumferential groove hydraulic pressure supply passage 132 and the axial hydraulic pressure supply passage 1.
It can be effectively used not only when communicating with 33 but also when not communicating.

In order to explain the present embodiment, FIG.
~ FIG. 12 shows the connecting rod 101 corresponding to one cylinder,
Although only the eccentric bearing 121 and the crank pin 112 are shown, it goes without saying that the variable compression ratio device for an internal combustion engine of this embodiment is also applicable to a multi-cylinder internal combustion engine.

FIG. 13 is a partial sectional side view of a third embodiment of a variable compression ratio device for an internal combustion engine of the present invention, and FIG. 14 shows a relative rotational positional relationship between a connecting rod, a piston pin, and an eccentric bearing during a change in compression ratio. It is the axial direction partial sectional view shown. 13 and 14, 201 is a connecting rod,
202 is the small end of the connecting rod, 212 is the piston pin,
213 is a piston pin flange provided on the piston pin 212. 221 is a small end portion 202 of the connecting rod and a piston pin 212 for changing the compression ratio of the internal combustion engine.
An eccentric bearing 222 inserted between and is a eccentric bearing flange provided on the eccentric bearing 221. 223 is a lock pin engagement hole formed in the inner circumference of the eccentric bearing 221, and 224 is a hydraulic pressure supply for lubrication that can communicate with the hydraulic pressure supply passage 231 to lubricate between the eccentric bearing 221 and the small end 202 of the connecting rod. It is a road. 23
1 is an oil pump (not shown) to a connecting rod 201,
A hydraulic pressure supply passage 232 extends to the outer circumference of the piston pin 212 through the inside of the eccentric bearing 221 and the piston pin 212, a circumferential groove-shaped hydraulic supply passage 232 formed in the inner circumference of the eccentric bearing 221 extends in the circumferential direction, Reference numeral 233 denotes an axial hydraulic pressure supply passage that is formed on the inner circumference of the eccentric bearing 221 and that extends axially from the circumferential groove hydraulic supply passage 232. A lock pin 241 is engageable with the lock pin engagement hole 223 for fixing the piston pin 212 and the eccentric bearing 221, and a reference numeral 242 is the lock pin engagement hole 223 for fixing the compression ratio at high compression. Is a lock pin spring for urging the lock pin spring. 243
Is a high compression engaging end that engages in the lock pin engaging hole 223 when the compression ratio is high compression, and 244 is a low compression that engages in the lock pin engaging hole 223 when the compression ratio is low compression. The engagement end 245 is a lock pin hydraulic pressure supply passage for supplying hydraulic pressure to urge the lock pin 241 toward the lock pin engagement hole 223 in order to fix the compression ratio to low compression.

When the compression ratio is fixed to high compression, the lock pin 241 is not supplied with the hydraulic pressure through the lock pin hydraulic pressure supply passage 245, and therefore the lock pin engaging hole 223 is locked. High compression engagement end 24 of pin 241
3 is engaged, and the piston pin 212 and the eccentric bearing 221 are fixed so that the relative rotational position does not change. The hydraulic pressure supply passage 231 communicates with the connecting rod 201 and the eccentric bearing 221 via the lubricating hydraulic pressure supply passage 224, and the connecting rod 201 and the eccentric bearing 221 are lubricated. During rotation of the crankshaft, piston pin 212 and eccentric bearing 22
1 does not slide, and eccentric bearing 221 and connecting rod 2
01 and slide.

When the compression ratio is changed from high compression to low compression, first, the hydraulic pressure is supplied to the lock pin 241 through the lock pin hydraulic pressure supply passage 245, and the fixation between the piston pin 212 and the eccentric bearing 221 is released. To be done. Therefore, not only the eccentric bearing 221 and the connecting rod 201 but also the piston pin 212 and the eccentric bearing 221.
Also becomes slidable as the crankshaft rotates.

When the crankshaft rotates, the piston pin 212 and the eccentric bearing 221 slide, and the relative rotational position of the piston pin 212 and the eccentric bearing 221 changes. As a result, the hydraulic pressure supply passage 231 is not communicated with the lubrication hydraulic pressure supply passage 224, but is instead communicated with the circumferential groove hydraulic pressure supply passage 232. As shown in detail in FIG. 13, the circumferential groove-shaped hydraulic pressure supply passage 232 is the axial hydraulic pressure supply passage 23.
3 to the right side (FIG. 2) end surface of the eccentric bearing flange 222. Therefore, the hydraulic pressure supply path 23
The hydraulic pressure supplied via 1, 232 and 233 presses the eccentric bearing 221 to the left side (FIG. 2), that is, the eccentric bearing flange 222 to the axial end surface of the connecting rod 201. As a result, the friction between the connecting rod 201 and the eccentric bearing 221 is increased. On the other hand, the circumferential groove-shaped hydraulic pressure supply passage 232 extends in the circumferential direction to extend the piston pin 212.
Since it is formed between the eccentric bearing 221 and the
The space between the piston pin 212 and the eccentric bearing 221 is lubricated. Therefore, during the rotation of the crankshaft, the piston pin 212 rotates with respect to the eccentric bearing 221 in a state where large friction is generated between the connecting rod 201 and the eccentric bearing 221.

Low compression engagement end 244 of the lock pin 241
When is engaged with the lock pin engaging hole 223, the piston pin 212 and the eccentric bearing 221 are fixed so that the relative rotational position does not change, and the compression ratio is fixed to low compression. Further, as in the case where the compression ratio is fixed to high compression, the hydraulic pressure supply passage 231 communicates with the connecting rod 201 and the eccentric bearing 221 via the lubricating hydraulic pressure supply passage 224, and 201 and eccentric bearing 2
21 is lubricated. When the compression ratio is fixed to high compression, during the rotation of the crankshaft, the piston pin 21
2 and the eccentric bearing 221 do not slide, but the eccentric bearing 221 and the connecting rod 201 slide.

As described above, according to the present embodiment, the hydraulic pressure supply passages 231 and 23 for supplying hydraulic pressure to increase the friction between the connecting rod 201 and the eccentric bearing 221.
2 and 233 are controlled to communicate with each other by the change in the relative rotational position between the eccentric bearing 221 and the piston pin 212 due to the rotation of the crankshaft. Therefore, unlike the case of the conventional variable compression ratio device for an internal combustion engine shown in FIG. 17, it is not necessary to specially provide a control valve for controlling the communication of the hydraulic pressure supply passage. Therefore, it is possible to avoid the cost increase of the device and the complication of the control circuit, which are associated with the special provision of the control valve.

Further, as described above, according to this embodiment, the eccentric bearing flange 222 provided on the eccentric bearing 221 is moved in the axial direction of the connecting rod 201 by the hydraulic pressure supplied through the hydraulic pressure supply passages 231, 232 and 233. By pressing against the end surface, friction between the connecting rod 201 and the eccentric bearing 221 is increased. Therefore, by changing the design of the radial length of the eccentric bearing flange 222, the magnitude of friction between the connecting rod 201 and the eccentric bearing 221 can be changed to a desired magnitude. Further, when the relative rotational position between the eccentric bearing 221 and the piston pin 212 changes to a predetermined position, the lock pin 241 fixes the piston pin 212 and the eccentric bearing 221.
The compression ratio can be reliably fixed to high compression or low compression.

Further, as described above, according to this embodiment, as shown in FIG. 13, the hydraulic pressure supply passages 231 and 232 are provided.
1 and 233, the entire eccentric bearing 221 is pushed by the hydraulic pressure supplied through the eccentric bearings 233, so that the actuator provided in the eccentric bearing is hydraulically operated.
The configuration of the eccentric bearing can be simplified as compared with the conventional case shown in FIG.

Further, as described above, according to the present embodiment, the hydraulic pressure supply passage 232 is the circumferential groove formed between the piston pin 212 and the eccentric bearing 221 and extending in the circumferential direction. The connecting rod 201 and the eccentric bearing 221 are driven by the hydraulic pressure supplied through the passage 232.
The friction between the piston pin 212 and
The space between the eccentric bearing 221 and the eccentric bearing 221 can be lubricated.

Further, as described above, according to the present embodiment, the hydraulic pressure supply passage 231 is provided with the circumferential groove hydraulic supply passage for supplying the hydraulic pressure for increasing the friction between the connecting rod 201 and the eccentric bearing 221. 232 and the axial hydraulic pressure supply passage 233 are not communicated, the lubricating hydraulic pressure supply passage 224
The hydraulic pressure supplied via the is used to lubricate between the connecting rod 201 and the eccentric bearing 221. Therefore, the hydraulic pressure supplied via the hydraulic pressure supply passage 231 is
It can be effectively used not only when communicating with the circumferential groove hydraulic pressure supply passage 232 and the axial hydraulic pressure supply passage 233 but also when not communicating.

Incidentally, in order to explain the present embodiment, FIG.
And in FIG. 14, the connecting rod 20 corresponding to one cylinder is shown.
1, only the eccentric bearing 221, and the piston pin 212 are shown, but it goes without saying that the variable compression ratio device for an internal combustion engine of the present embodiment is also applicable to a multi-cylinder internal combustion engine.

FIG. 15 is a partial sectional side view of a fourth embodiment of a variable compression ratio device for an internal combustion engine according to the present invention, and FIG. 16 shows a relative rotational positional relationship between a connecting rod, a piston pin and an eccentric bearing during a compression ratio change. It is the axial direction partial sectional view shown. 15 and 16, 301 is a connecting rod,
302 is the small end of the connecting rod, 312 is the piston pin,
313 is a piston pin flange provided on the piston pin 312. 321 is a small end portion 302 of the connecting rod and a piston pin 312 for changing the compression ratio of the internal combustion engine.
An eccentric bearing 322 inserted between and is an eccentric bearing flange provided on the eccentric bearing 321. Reference numeral 323 is a lock pin engagement hole formed in the eccentric bearing flange 322, and 324 is a lubrication hydraulic pressure supply passage that can communicate with the hydraulic pressure supply passage 331 to lubricate between the eccentric bearing 321 and the connecting rod small end 302. is there. Three
31 is an oil pump (not shown) to a connecting rod 301
The hydraulic supply passage 332 extending to the outer circumference of the eccentric bearing 321 via the circumferential groove-shaped hydraulic supply passage 333 extending in the circumferential direction formed on the outer circumference of the eccentric bearing 321 is formed on the outer circumference of the eccentric bearing 321. And is an axial hydraulic supply passage extending in the axial direction from the circumferential groove hydraulic supply passage 332. 341 is a lock pin engaging hole 323 for fixing the connecting rod 301 and the eccentric bearing 321.
It is a lock pin that can be engaged with. Although not shown, the biasing means of the lock pin 341 is substantially the same as that of the third embodiment.

When the compression ratio is fixed at a high compression, the lock pin 341 has the lock pin engaging hole 3 on the right side (FIG. 15).
23, the connecting rod 301 and the eccentric bearing 321 are fixed so that the relative rotational position does not change. The hydraulic pressure supply passage 331 is on the lower side (FIG. 16).
Through the lubricating oil pressure supply passage 324 of the piston pin 31
2 and the eccentric bearing 321 are communicated with each other, and the piston pin 312 and the eccentric bearing 321 are lubricated. During the rotation of the crankshaft, the connecting rod 301 and the eccentric bearing 321 do not slide and the eccentric bearing 3
21 and the piston pin 312 slide.

When the compression ratio is changed from the high compression to the low compression, first, the lock pin 341 and the lock pin engagement hole 323 are provided.
, And the fixing of the connecting rod 301 and the eccentric bearing 321 is released. Therefore, not only the eccentric bearing 321 and the piston pin 312 but also the connecting rod 301 and the eccentric bearing 321 can slide with the rotation of the crankshaft.

When the crankshaft rotates, the connecting rod 301 and the eccentric bearing 321 slide, and the relative rotational position between the connecting rod 301 and the eccentric bearing 321 changes. As a result, the hydraulic pressure supply passage 331 does not communicate with the lubrication hydraulic pressure supply passage 324, but instead communicates with the circumferential groove hydraulic pressure supply passage 332. As shown in detail in FIG.
The circumferential groove hydraulic pressure supply passage 332 is located on the left side of the eccentric bearing flange 322 via the axial hydraulic pressure supply passage 333 (FIG. 15).
It communicates with the end face. Therefore, the hydraulic pressure supply passage 331,
The hydraulic pressure supplied via 332 and 333 presses the eccentric bearing 321 to the right (FIG. 15), that is, the eccentric bearing flange 322 to the piston pin flange 313. As a result, the friction between the piston pin 312 and the eccentric bearing 321 is increased. On the other hand, since the circumferential groove-shaped hydraulic pressure supply passage 332 extends in the circumferential direction and is formed between the connecting rod 301 and the eccentric bearing 321, the connecting rod 301 and the eccentric bearing 321 are lubricated. Therefore, during the rotation of the crankshaft, the connecting rod 301 rotates with respect to the eccentric bearing 321 while a large friction is generated between the piston pin 312 and the eccentric bearing 321.

When the lock pin 341 engages with the lock pin engagement hole 323 on the left side (FIG. 15), the connecting rod 301 and the eccentric bearing 321 are fixed so that their relative rotational positions do not change, and the compression ratio is reduced. Fixed. Also,
As in the case of being fixed at high compression, the hydraulic pressure supply passage 331 is
Via the lubrication hydraulic pressure supply passage 324, the piston pin 312
And the eccentric bearing 321 communicate with each other, and the piston pin 312 and the eccentric bearing 321 are lubricated. When the compression ratio is fixed, the connecting rod 301 and the eccentric bearing 321 do not slide but the eccentric bearing 321 and the piston pin 312 slide while the crankshaft rotates.

As described above, according to this embodiment, the hydraulic pressure supply passages 331, 3 for supplying hydraulic pressure to increase the friction between the piston pin 312 and the eccentric bearing 321.
32 and 333 are controlled to communicate with each other by the change in the relative rotational position between the eccentric bearing 321 and the connecting rod 301 due to the rotation of the crankshaft. Therefore, unlike the case of the conventional variable compression ratio device for an internal combustion engine shown in FIG. 17, it is not necessary to specially provide a control valve for controlling the communication of the hydraulic pressure supply passage. Therefore, it is possible to avoid the cost increase of the device and the complication of the control circuit, which are associated with the special provision of the control valve.

As described above, according to this embodiment, the eccentric bearing flange 322 provided on the eccentric bearing 321 is attached to the piston pin flange 313 by the hydraulic pressure supplied through the hydraulic pressure supply passages 331, 332 and 333. By pressing, the friction between the piston pin 312 and the eccentric bearing 321 is increased. Therefore, by designing the radial length of the eccentric bearing flange 322, the magnitude of friction between the piston pin 312 and the eccentric bearing 321 can be changed to a desired magnitude. Further, when the relative rotational position between the eccentric bearing 321 and the connecting rod 301 changes to a predetermined position, the connecting pin 301 and the eccentric bearing 321 are fixed by the lock pin 341, so that the compression ratio is ensured to be high compression or low compression. Can be fixed to.

Further, as described above, according to this embodiment, as shown in FIG. 15, the hydraulic pressure supply passages 331 and 332 are provided.
Since the entire eccentric bearing 321 is pushed by the hydraulic pressure supplied through the eccentric bearings 333 and 333, the actuator provided in the eccentric bearing is hydraulically operated.
The configuration of the eccentric bearing can be simplified as compared with the conventional case shown in FIG.

Further, as described above, according to this embodiment, the hydraulic pressure supply passage 332 is the circumferential groove formed between the connecting rod 301 and the eccentric bearing 321 and extending in the circumferential direction. The hydraulic pressure supplied via 332 causes the piston pin 312 and the eccentric bearing 321 to move.
The friction between the connecting rod 301 and the eccentric bearing 321 can be increased while increasing the friction between the connecting rod 301 and the eccentric bearing 321.

Further, as described above, according to this embodiment, the hydraulic pressure supply passage 331 supplies the hydraulic pressure for increasing the friction between the piston pin 312 and the eccentric bearing 321 to the circumferential groove hydraulic pressure supply. When not communicating with the passage 332 and the axial hydraulic pressure supply passage 333, the lubricating hydraulic supply passage 32 is provided.
The hydraulic pressure supplied via 4 is used to lubricate between the piston pin 312 and the eccentric bearing 321. Therefore, the hydraulic pressure supplied via the hydraulic pressure supply passage 331 is changed to the circumferential groove hydraulic pressure supply passage 332 and the axial hydraulic pressure supply passage 3.
It can be effectively used not only when communicating with 33 but also when not communicating.

In order to explain the present embodiment, FIG.
16 and 16 show the connecting rod 30 corresponding to one cylinder.
1, only the eccentric bearing 321, and the piston pin 312 are shown, but it goes without saying that the variable compression ratio device for an internal combustion engine of the present embodiment is also applicable to a multi-cylinder internal combustion engine.

[0092]

According to the invention described in claim 1, there is no need to specially provide a control valve for communicating control of the hydraulic pressure supply passage, and therefore, the cost of the apparatus accompanying the special provision of the control valve. It is possible to avoid complication of the up and control circuit.

According to the second aspect of the present invention, the magnitude of friction between the connecting rod and the eccentric bearing can be changed to a desired magnitude by changing the radial length of the flange.

According to the invention described in claim 3, the compression ratio can be reliably fixed.

According to the fourth aspect of the invention, the hydraulic pressure supplied through the hydraulic pressure supply passage increases the friction between the connecting rod and the eccentric bearing and lubricates the crankpin and the eccentric bearing. be able to.

According to the fifth aspect of the invention, the hydraulic pressure supplied through the hydraulic pressure supply passage can be effectively used not only when communicating but also when not communicating.

According to the invention described in claim 6, it is not necessary to specially provide a control valve for controlling the communication of the hydraulic pressure supply passage, and therefore, the cost of the apparatus is increased due to the special provision of the control valve. It is possible to avoid complication of the control circuit.

According to the seventh aspect of the present invention, by changing the radial length of the flange, the magnitude of friction between the crankpin and the eccentric bearing can be changed to a desired magnitude.

According to the invention described in claim 8, the compression ratio can be reliably fixed.

According to the ninth aspect of the present invention, the hydraulic pressure supplied through the hydraulic pressure supply passage increases the friction between the crankpin and the eccentric bearing and lubricates the connecting rod and the eccentric bearing. be able to.

According to the tenth aspect of the present invention, the hydraulic pressure supplied through the hydraulic pressure supply passage can be effectively used not only when communicating but also when not communicating.

According to the eleventh aspect of the present invention, it is not necessary to specially provide a control valve for controlling the hydraulic pressure supply passage so that the cost of the device increases due to the special provision of the control valve. It is possible to avoid complication of the control circuit.

According to the twelfth aspect of the present invention, the magnitude of friction between the connecting rod and the eccentric bearing can be changed to a desired magnitude by changing the radial length of the flange.

According to the thirteenth aspect of the present invention, the compression ratio can be reliably fixed.

According to the fourteenth aspect of the invention, the hydraulic pressure supplied through the hydraulic pressure supply passage increases the friction between the connecting rod and the eccentric bearing and lubricates the piston pin and the eccentric bearing. be able to.

According to the fifteenth aspect of the present invention, the hydraulic pressure supplied through the hydraulic pressure supply passage can be effectively used not only when communicating but also when not communicating.

According to the sixteenth aspect of the present invention, it is not necessary to specially provide a control valve for controlling communication of the hydraulic pressure supply passage, and therefore, the cost of the device increases due to the special provision of the control valve and It is possible to avoid complication of the control circuit.

According to the seventeenth aspect of the present invention, the magnitude of friction between the piston pin and the eccentric bearing can be changed to a desired magnitude by changing the radial length of the eccentric bearing flange. it can.

According to the eighteenth aspect of the present invention, the compression ratio can be reliably fixed.

According to the nineteenth aspect of the present invention, the hydraulic pressure supplied through the hydraulic pressure supply passage increases the friction between the piston pin and the eccentric bearing and lubricates the connecting rod and the eccentric bearing. be able to.

According to the twentieth aspect of the invention, the hydraulic pressure supplied through the hydraulic pressure supply passage can be effectively utilized not only during communication but also during non-communication.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional side view of a first embodiment of a variable compression ratio device for an internal combustion engine of the present invention.

FIG. 2 is an enlarged view in which a part of FIG. 1 is enlarged.

FIG. 3 is an axial partial cross-sectional view showing the relative rotational positional relationship among the connecting rod, the crank pin, and the eccentric bearing over time.

FIG. 4 is a partial axial sectional view showing a relative rotational positional relationship among a connecting rod, a crank pin, and an eccentric bearing, over time.

FIG. 5 is a partial axial sectional view showing a relative rotational positional relationship among a connecting rod, a crank pin, and an eccentric bearing, over time.

FIG. 6 is a partial axial sectional view showing a relative rotational positional relationship among a connecting rod, a crank pin, and an eccentric bearing, over time.

FIG. 7 is an axial partial cross-sectional view showing the relative rotational positional relationship among the connecting rod, the crank pin, and the eccentric bearing over time.

FIG. 8 is a partial axial sectional view showing a relative rotational positional relationship among a connecting rod, a crank pin, and an eccentric bearing, over time.

FIG. 9 is a partial axial sectional view showing a relative rotational positional relationship among a connecting rod, a crank pin, and an eccentric bearing, over time.

FIG. 10 is a partial cross-sectional side view of the second embodiment of the variable compression ratio device for an internal combustion engine of the present invention.

FIG. 11 is an enlarged view of a part of FIG.

FIG. 12 is a partial axial sectional view showing a relative rotational positional relationship among a connecting rod, a crank pin, and an eccentric bearing during a change in compression ratio.

FIG. 13 is a partial sectional side view of a third embodiment of the variable compression ratio device for an internal combustion engine of the present invention.

FIG. 14 is a partial axial sectional view showing a relative rotational positional relationship among the connecting rod, the piston pin, and the eccentric bearing during the change of the compression ratio.

FIG. 15 is a partial sectional side view of a fourth embodiment of a variable compression ratio device for an internal combustion engine of the present invention.

FIG. 16 is a partial axial sectional view showing a relative rotational positional relationship among the connecting rod, the piston pin and the eccentric bearing during the change of the compression ratio.

FIG. 17 is a partial sectional side view of a conventional variable compression ratio device for an internal combustion engine.

[Explanation of symbols]

1 ... connecting rod 2 ... Large end of connecting rod 12 ... crank pin 21 ... Eccentric bearing 31 ... Hydraulic supply path

Claims (20)

[Claims] 1. A compression ratio is changed by inserting an eccentric bearing between a large end portion of a connecting rod and a crank pin to change the compression ratio of an internal combustion engine, and rotating the eccentric bearing with respect to the crank pin. At times, a variable compression ratio device for an internal combustion engine is configured to supply hydraulic pressure to increase friction between the connecting rod and the eccentric bearing, and a hydraulic pressure supply passage for supplying hydraulic pressure to increase friction. A variable compression ratio device for an internal combustion engine, wherein communication is controlled by a change in a relative rotational position of the eccentric bearing and the crank pin due to rotation of a crankshaft. 2. The friction between the connecting rod and the eccentric bearing is caused by pressing a flange provided on the eccentric bearing against an axial end surface of the connecting rod by the hydraulic pressure supplied through the hydraulic pressure supply passage. 2. The variable compression ratio device for an internal combustion engine according to claim 1, wherein: 3. A lock pin for fixing the crank pin and the eccentric bearing is released before increasing friction between the connecting rod and the eccentric bearing, and relative rotation between the eccentric bearing and the crank pin. The variable compression ratio device for an internal combustion engine according to claim 1, wherein the crank pin and the eccentric bearing are fixed by the lock pin when the position changes to a predetermined position. 4. The internal combustion engine according to claim 1, wherein a part of the hydraulic pressure supply passage is a circumferential groove formed between the crank pin and the eccentric bearing and extending in a circumferential direction. Variable compression ratio device. 5. The hydraulic pressure supplied through the hydraulic pressure supply passage when the hydraulic pressure supply passage is not communicated to supply hydraulic pressure for increasing friction between the connecting rod and the eccentric bearing, 2. The variable compression ratio device for an internal combustion engine according to claim 1, wherein the variable compression ratio device is used to lubricate between the connecting rod and the eccentric bearing. 6. An eccentric bearing is inserted between the large end of the connecting rod and the crank pin to change the compression ratio of the internal combustion engine, and the compression ratio is changed by rotating the eccentric bearing with respect to the connecting rod. In a variable compression ratio device for an internal combustion engine in which hydraulic pressure is supplied to increase friction between the crankpin and the eccentric bearing, a hydraulic pressure supply passage for supplying hydraulic pressure to increase friction has a crankshaft. A variable compression ratio device for an internal combustion engine, the communication of which is controlled by a change in a relative rotational position between the eccentric bearing and the connecting rod due to rotation of the. 7. The friction between the crank pin and the eccentric bearing is caused by pressing a flange provided on the eccentric bearing against an axial end surface of a crank arm by hydraulic pressure supplied through the hydraulic pressure supply passage. The variable compression ratio device for an internal combustion engine according to claim 6, wherein 8. A lock pin for fixing the connecting rod and the eccentric bearing is released before increasing friction between the crankpin and the eccentric bearing, and relative rotation between the eccentric bearing and the connecting rod. 7. The variable compression ratio device for an internal combustion engine according to claim 6, wherein the connecting pin and the eccentric bearing are fixed by the lock pin when the position changes to a predetermined position. 9. The internal combustion engine according to claim 6, wherein a part of the hydraulic pressure supply passage is a circumferential groove formed between the connecting rod and the eccentric bearing and extending in a circumferential direction. Variable compression ratio device. 10. The hydraulic pressure supplied through the hydraulic pressure supply passage when the hydraulic pressure supply passage is not communicated to supply hydraulic pressure for increasing friction between the crank pin and the eccentric bearing, 7. The variable compression ratio device for an internal combustion engine according to claim 6, wherein the variable compression ratio device is used to lubricate between the crankpin and the eccentric bearing. 11. An eccentric bearing is inserted between a small end of a connecting rod and a piston pin to change the compression ratio of an internal combustion engine, and the compression ratio is changed by rotating the eccentric bearing with respect to the piston pin. At times, a variable compression ratio device for an internal combustion engine is configured to supply hydraulic pressure to increase friction between the connecting rod and the eccentric bearing, and a hydraulic pressure supply passage for supplying hydraulic pressure to increase friction. A variable compression ratio device for an internal combustion engine, wherein communication is controlled by a change in relative rotational position between the eccentric bearing and the piston pin due to rotation of a crankshaft. 12. A flange provided on the eccentric bearing is pressed against an axial end surface of the connecting rod by a hydraulic pressure supplied through the hydraulic pressure supply passage,
The variable compression ratio device for an internal combustion engine according to claim 11, wherein friction between the connecting rod and the eccentric bearing is increased. 13. A lock pin for fixing the piston pin and the eccentric bearing is released before increasing friction between the connecting rod and the eccentric bearing, and relative rotation between the eccentric bearing and the piston pin. 12. The variable compression ratio device for an internal combustion engine according to claim 11, wherein the piston pin and the eccentric bearing are fixed by the lock pin when the position changes to a predetermined position. 14. The internal combustion engine according to claim 11, wherein a part of the hydraulic pressure supply passage is a circumferential groove formed between the piston pin and the eccentric bearing and extending in a circumferential direction. Variable compression ratio device. 15. The hydraulic pressure supplied through the hydraulic pressure supply passage when the hydraulic pressure supply passage is not communicated to supply hydraulic pressure for increasing friction between the connecting rod and the eccentric bearing, The variable compression ratio device for an internal combustion engine according to claim 11, wherein the variable compression ratio device is used to lubricate between the connecting rod and the eccentric bearing. 16. An eccentric bearing is inserted between a small end of a connecting rod and a piston pin to change a compression ratio of an internal combustion engine, and the compression ratio is changed by rotating the eccentric bearing with respect to the connecting rod. In a variable compression ratio device for an internal combustion engine, which is configured to supply hydraulic pressure to increase friction between the piston pin and the eccentric bearing, a hydraulic pressure supply passage for supplying hydraulic pressure to increase friction is a crankshaft. A variable compression ratio device for an internal combustion engine, the communication of which is controlled by a change in a relative rotational position between the eccentric bearing and the connecting rod due to rotation of the. 17. The piston pin and the eccentricity are provided by pressing an eccentric bearing flange provided on the eccentric bearing against a piston pin flange provided on the piston pin by hydraulic pressure supplied through the hydraulic pressure supply passage. 17. The variable compression ratio device for an internal combustion engine according to claim 16, wherein friction between the bearing and the bearing is increased. 18. A lock pin for fixing the connecting rod and the eccentric bearing is released before increasing friction between the piston pin and the eccentric bearing, and relative rotation between the eccentric bearing and the connecting rod. The variable compression ratio device for an internal combustion engine according to claim 16, wherein the lock rod fixes the connecting rod and the eccentric bearing when the position changes to a predetermined position. 19. The internal combustion engine according to claim 16, wherein a part of the hydraulic pressure supply passage is a circumferential groove formed between the connecting rod and the eccentric bearing and extending in a circumferential direction. Variable compression ratio device. 20. When the hydraulic pressure supply passage is not communicated to supply hydraulic pressure for increasing friction between the piston pin and the eccentric bearing, the hydraulic pressure supplied through the hydraulic pressure supply passage is: The variable compression ratio device for an internal combustion engine according to claim 16, wherein the variable compression ratio device is used to lubricate between the piston pin and the eccentric bearing.