JP7316337B2 - Compression ratio variable device - Google Patents

Description

The present invention relates to a variable compression ratio device.

Conventionally, there is known a crankshaft support structure for an internal combustion engine provided with an oil passage for supplying lubricating oil to a bearing portion of the crankshaft or the like (see, for example, Patent Document 1). In addition, a multi-link variable compression ratio engine configuration is disclosed that can prevent lubricating oil from flowing out to the combustion chamber and suppress oil deterioration due to blow-by gas containing unburned fuel (for example, Patent Document 2). reference). An eccentric cam is provided between the crankpin of the crankshaft and the big end of the connecting rod, and the eccentric cam is rotated by a motor to make the distance between the central axis of the big end and the axis of the crankshaft variable. Variable compression ratio devices are known.

JP 2012-36934 A Japanese Patent Application Laid-Open No. 2009-36128

However, in the above structure, no consideration is given to the supply of oil to the variable compression ratio device.
The present invention has been made in view of the circumstances described above, and an object of the present invention is to supply oil to a variable compression ratio device.

The present invention comprises a gear shaft arranged coaxially inside a crankshaft of an internal combustion engine and rotationally driven by a power source, an input gear connected to the gear shaft, and supported by a crank web of the crankshaft, A variable compression ratio device comprising: an intermediate gear that meshes with an input gear; and an eccentric cam that is disposed between a crankpin of the crankshaft and a large end of a connecting rod and meshes with the intermediate gear, wherein lubricating oil is supplied to the input gear. and a primary gear collar for positioning the primary gear on the crankshaft, and at least part of the first oil passage is provided inside the primary gear collar.

Since the crankshaft is provided with the first oil passage for supplying lubricating oil to the input gear, it is possible to supply oil to the input gear of the variable compression ratio device.

FIG. 2 is a diagram showing the internal structure of the variable compression ratio device of the present invention; It is the figure which showed the crank pin and the eccentric cam with the peripheral structure. It is an enlarged view near the input gear of the compression ratio variable device.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description, directions such as front, rear, left, right, and up and down are the same as the directions with respect to the vehicle body unless otherwise specified. In each figure, FR indicates the front of the vehicle body, UP indicates the upper side of the vehicle body, and LH indicates the left side of the vehicle body.

FIG. 1 is a diagram showing the internal structure of a power unit 10 equipped with a variable compression ratio device 10a of this embodiment. This power unit 10 is a power unit mounted on a motorcycle, and includes an engine 11 that is an internal combustion engine. This power unit is not limited to a motorcycle, and may be a power unit mounted on various saddle type vehicles including three-wheeled and four-wheeled vehicles.

The engine 11 has a crankcase 15 that rotatably supports a crankshaft 12 via a plurality of bearings 13 and 14, and is connected to the crankshaft 12 via a crank web 16, a crank pin 17 and a connecting rod 18 in this order. and a cylinder portion 20 that slidably accommodates a piston (not shown).

A primary gear 21 that meshes with a driven gear (not shown) is supported by the crankshaft 12 . A primary gear collar 60 that positions the primary gear 21 is provided between the primary gear 21 and the bearing 13 that supports the crankshaft 12 . FIG. 1 shows a horizontal engine 11 in which a cylinder portion 20 horizontally protrudes forward from a crankcase 15 .
In FIG. 1, reference symbol C1 indicates the axis of the crankshaft 12 supported by the crankcase 15. As shown in FIG. A reference C2 indicates the axis of the crankpin 17. As shown in FIG. The axis C1 of the crankshaft 12 and the axis C2 of the crankpin 17 are parallel.

The variable compression ratio device 10a includes an eccentric cam 31 between the outer circumference of the crankpin 17 of the crankshaft 12 and the inner circumference of the big end 18a of the connecting rod 18 . The variable compression ratio device 10 a also includes a motor 32 that serves as a power source for the eccentric cam 31 and a power transmission mechanism 33 that transmits the power of the motor 32 to the eccentric cam 31 .
The power transmission mechanism 33 includes a gear shaft 52 coaxially arranged inside the crankshaft 12 of the internal combustion engine 11 and an input gear 51 connected to an end of the gear shaft 52 . The power transmission mechanism 33 also includes an intermediate gear 50 supported by the crank web 16 . The intermediate gear 50 is supported by the crank web 16 via a support shaft 50c, and includes a small-diameter gear 50b and a large-diameter gear 50a coaxially integrated with the small-diameter gear 50b.
A small diameter gear 50 b of the intermediate gear 50 meshes with the input gear 51 , and a large diameter gear 50 a of the intermediate gear 50 meshes with the gear portion 31 a of the eccentric cam 31 .

The gear shaft 52 is arranged coaxially with the crankshaft 12 inside the crankshaft 12 and is rotatably supported via a pair of bearings 56 and 57 . The gear shaft 52 passes through a cover 58 arranged on the right side of the crankshaft 12 and extends to the vicinity of the motor 32 . Oil (indicated by symbol J in FIG. 1) is supplied into the cover 58 from an oil pump (not shown) provided in the power unit 10, and the bearings 56 and 57 are lubricated with this oil.

The drive-side gear portion 53 has a worm gear 53 a keyed to the base end of the gear shaft 52 . The configuration of the drive-side gear portion 53 is not limited to the configuration using the worm gear 53a, and a known speed reduction mechanism can be appropriately employed. Moreover, although the case where the motor 32 was the power source was exemplified, the power source may be other than the motor 32 .

The rotation angle of the motor 32 is controlled by a control unit 41 mounted on the motorcycle. The control unit 41 acquires the rotational position of a part of the power transmission mechanism 33 (the rotational position of the gear shaft 52 in this configuration) via the potentiometer 42, and moves the motor 32 to the target position based on the acquired rotational position. Rotation control. The control unit 41 is, for example, an ECU (Electronic Control Unit) provided in a motorcycle.

Next, the eccentric cam 31, the power transmission mechanism 33, and their peripheral structures will be described.
FIG. 2 is a diagram showing the crank pin 17 and the eccentric cam 31 together with their peripheral structures, and is a view taken along line II-II in FIG.
As shown in the figure, the eccentric cam 31 has a thickness t that gradually changes in the circumferential direction. When the motor 32 is driven, the power of the eccentric cam 31 is transmitted to the eccentric cam 31 via the power transmission mechanism 33 and rotates in the circumferential direction.

At the reference position, the position of the center axis C0 of the large end 18a of the connecting rod 18 coincides with the position of the axis C2 of the crank pin 17. As shown in FIG.
When the eccentric cam 31 rotates, the thickness t of the eccentric cam 31 changes in the circumferential direction. It is displaced to the position of the axis C3. This displacement changes the distance between the central axis C0 of the big end 18a and the axis C1 of the crankshaft 12, changes the stroke amount of the piston, and changes the compression ratio.

A gear portion 31a is provided on the outer circumference of the eccentric cam 31, as shown in FIG. The gear portion 31 a of the eccentric cam 31 meshes with the large-diameter gear 50 a of the intermediate gear 50 , and the small-diameter gear 50 b of the intermediate gear 50 meshes with the input gear 51 of the gear shaft 52 . The intermediate gear 50 is a two-stage gear including a large-diameter gear 50a and a small-diameter gear 50b.

As shown in FIG. 2 , at least part (lower half) of the intermediate gear 50 is covered with a cover member 62 . The cover member 62 is fastened to the crank web 16 by two fastening members 54,54. An opening 62b is provided in the central portion of the cover member 62, and one end 50d of the support shaft 50c of the intermediate gear 50 is rotatably fitted in the opening 62b as shown in FIG. The other end 50e is rotatably fitted in the opening 16c of the crank web 16. As shown in FIG. The intermediate gear 50 is thus supported by the crank web 16 and the cover member 62 . The fastening member 54 functions as a component that fastens the cover member 62 to the crank web 16 .

The cover member 62 is tightly joined to the crank web 16 at its peripheral edge 62a, including the lower region, and sealed with a gasket or filler.
A space between the crank web 16 and the cover member 62 forms an oil reservoir 63 for lubricating oil. When the internal combustion engine 11 is restarted, the lubricating oil accumulates in the vicinity of the intermediate gear 50 due to the presence of the oil reservoir 63, thereby improving the initial lubricity of the variable compression ratio device.
Note that sealing with a gasket or filler is not essential, and the sealing material can be omitted. During normal operation, the lubricating oil is always supplied by centrifugal force, and is stored to lubricate the input gear 51 on the center side.

Next, the lubricating oil supply route of the variable compression ratio device 10a will be described.
As shown in FIG. 3, the gear shaft 52 is inserted into the through hole 71 of the crankshaft 12. As shown in FIG. An annular third oil passage 73 is formed between the inner circumference of the through hole 71 of the crankshaft 12 and the outer circumference of the gear shaft 52 .
The third oil passage 73 is supplied with oil (indicated by symbol J in FIG. 1) from an oil pump (not shown) provided in the power unit 10 .

The third oil passage 73 communicates with small hole-shaped fourth oil passages 74 and fifth oil passages 75 formed in the crankshaft 12 . The fourth oil passage 74 and the fifth oil passage 75 communicate with the annular sixth oil passage 76 . An annular sixth oil passage 76 is formed between a primary gear collar 60 that positions the primary gear 21 and the outer circumference of the crankshaft 12 . Since the sixth oil passage 76 is provided inside the primary gear collar 60, it is possible to reduce the number of parts constituting the oil passage, thereby improving manufacturing efficiency.

The sixth oil passage 76 communicates with the first oil guiding passage 65 formed in the crankshaft 12 in the lower middle portion of FIG. 3, and the second oil guiding passageway 67 similarly formed in the crankshaft 12 in the upper middle portion of FIG. communicates with

The first oil guide passage 65 extends obliquely toward the axis C<b>1 of the crankshaft 12 and is provided in a direction along the crankshaft 12 . An orifice 64 is provided at the end of the first oil guide passage 65 on the side of the input gear 51 . An orifice 64 is provided in the crank web 16 . The orifice 64 has an opening at a position facing the tooth surface of the input gear 51 . The diameter of the orifice 64 is desirably 1 mm or less.

The lubricating oil supplied to the first oil guide passage 65 is supplied through the orifice 64 to the tooth surface of the input gear 51 of the variable compression ratio device 10a. Since the lubricating oil is supplied through the orifice 64, the amount of lubricating oil can be adjusted and the lubrication can be ensured.
In addition, since the first oil guide passage 65 is inclined toward the axis C1 of the crankshaft 12, foreign matter present in the lubricating oil tends to stick to the inner peripheral surface of the first oil guide passage 65 due to centrifugal force. The cleanliness of the lubricating oil supplied to the variable device 10a is maintained.

The "first oil passage 5" is provided in the peripheral portion of the crank web 16, and includes a third annular oil passage 73, a fourth small-hole oil passage 74, a sixth annular oil passage 76, and a sixth oil passage 76. It is composed of an oil guide passage 65 and an orifice 64 .
Each of the oil passages 74, 65, 64 is formed by piercing the crankshaft 12 or the crank web 16, and the sixth oil passage 76 is formed inside the primary gear collar 60, so that the first oil passage 5 is The structure is simple and compact.

The second oil guide passage 67 extends obliquely toward the crankshaft axis C<b>1 and is provided in a direction along the crankshaft 12 . The second oil passage 67 communicates with a seventh oil passage 77 formed in the crankpin 17 by bending in the middle and an eighth oil passage 78 orthogonal to the seventh oil passage 77 . The lubricating oil supplied to the eighth oil passage 78 is supplied to the inner peripheral surface of the large end portion 18a of the connecting rod 18 through the hole 78a. The second oil guide passage 67 is inclined toward the axis C1 of the crankshaft. Therefore, foreign matter present in the lubricating oil tends to stick to the inner peripheral surface of the second oil guiding passage 67 due to centrifugal force. Therefore, the lubricating oil supplied to the crankpin 17 is kept clean.

The "second oil passage 7" is provided in the peripheral portion of the crank web 16, and includes an annular third oil passage 73, a small hole-shaped fifth oil passage 75, an annular sixth oil passage 76, and a second oil passage. It is composed of an oil passage 67 , a seventh oil passage 77 and an eighth oil passage 78 .
The oil passages 75 , 67 , 77 , 78 are formed by drilling the crankshaft 12 or the crank web 16 , and the sixth oil passage 76 is formed inside the primary gear collar 60 . has a simple and compact structure.

(Configurations supported by the above embodiments)
The above embodiment supports the following configurations.

(Configuration 1) A gear shaft coaxially arranged inside a crankshaft of an internal combustion engine and rotationally driven by a power source, an input gear connected to the gear shaft, and supported by a crank web of the crankshaft, A variable compression ratio device comprising: an intermediate gear that meshes with an input gear; and an eccentric cam that is disposed between a crankpin of the crankshaft and a large end of a connecting rod and meshes with the intermediate gear, wherein lubricating oil is supplied to the input gear. A variable compression ratio device, wherein a first oil passage for supplying a is provided in the crankshaft.
According to such a configuration, it is possible to reliably supply oil to the input gear. In addition, centrifugal force can be used to supply the lubricating oil to the intermediate gear as well. That is, there is an effect that each part of the eccentric cam drive mechanism can be efficiently lubricated.

(Arrangement 2) The variable compression ratio device according to Arrangement 1, wherein the first oil passage is provided in a peripheral portion of the crank web.
According to such a configuration, the first oil passage can be formed compactly.

(Configuration 3) The compression system according to configuration 1 or 2, wherein a primary gear collar for positioning the primary gear is provided on the crankshaft, and at least part of the first oil passage is provided inside the primary gear collar. Ratio variable device.
With such a configuration, the number of parts can be reduced, and the manufacturing efficiency can be improved.

(Configuration 4) The variable compression ratio device according to any one of Configurations 1 to 3, wherein an orifice is provided at the input gear side end of the first oil passage.
According to such a configuration, the amount of lubricating oil can be easily adjusted, and the effect of ensuring oil supply to the variable compression ratio device is exhibited.

(Arrangement 5) A variable compression ratio device according to any one of Arrangements 1 to 4, wherein the first oil passage includes a first oil guide passage that is inclined with respect to the axis of the crankshaft.
According to such a configuration, foreign matter present in the lubricating oil can be easily stuck in the outer peripheral direction by centrifugal force. Therefore, it is possible to easily maintain the cleanliness of the lubricating oil introduced to the variable compression ratio device.

(Arrangement 6) From Arrangement 1, wherein a second oil passage for supplying lubricating oil to the crankpin is provided, and the second oil passage includes a second oil guide passage inclined with respect to the axis of the crankshaft. A variable compression ratio device according to any one of configurations 5.
According to such a configuration, foreign matter present in the lubricating oil can be easily stuck in the outer peripheral direction by centrifugal force. Therefore, there is an effect of making it easy to maintain the cleanliness of the lubricating oil that is led to the crankpin.

(Structure 7) The variable compression ratio device according to any one of structures 1 to 6, further comprising a cover member that covers at least a portion of the intermediate gear from the outside and can form an oil reservoir inside. .
According to such a configuration, lubricating oil remains in the vicinity of the intermediate gear when the internal combustion engine is restarted, so initial lubrication of the variable compression ratio device is improved.

In addition, the above-described embodiment shows one mode to which the present invention is applied, and the present invention is not limited to the above-described embodiment.

3 eccentric cam drive mechanism 5 first oil passage 7 second oil passage 10 power unit 10a variable compression ratio device 11 engine (internal combustion engine)
16 crank web 17 crank pin 18 connecting rod
21 primary gear 31 eccentric cam 50 intermediate gear 51 input gear 52 gear shaft 60 primary gear collar 62 cover member 64 orifice 65 first oil passage 67 second oil passage C1 crankshaft axis

Claims (6)

A gear shaft (52) coaxially arranged inside a crankshaft (12) of an internal combustion engine (11) and driven to rotate by a power source (32); and an input gear (51) connected to the gear shaft (52). ), an intermediate gear (50) supported by a crank web (16) of the crankshaft (12) and meshing with the input gear (51), a crankpin (17) of the crankshaft (12) and a connecting rod ( 18) and an eccentric cam (31) disposed between the large end (18a) of the intermediate gear (50) and meshing with the intermediate gear (50),
A first oil passage (5) for supplying lubricating oil to the input gear (51) ,
A primary gear collar (60) for positioning the primary gear (21) is provided on the crankshaft (12), and at least part of the first oil passage (5) is provided inside the primary gear collar (60). A variable compression ratio device characterized by: 2. A variable compression ratio apparatus according to claim 1, wherein said first oil passage (5) is provided in a peripheral portion of said crank web (16). 3. The variable compression ratio device according to claim 1, wherein an orifice (64) is provided at the end of the first oil passage (5) on the side of the input gear (51). 4. Any one of claims 1 to 3 , wherein the first oil passage (5) includes a first oil guide passage (65) inclined with respect to the axis (C1) of the crankshaft (12). 1. A variable compression ratio device according to claim 1. A second oil passage (7) for supplying lubricating oil to the crankpin (17) is provided, and the second oil passage (7) is inclined with respect to the axis (C1) of the crankshaft (12). 5. A variable compression ratio device according to any preceding claim, comprising a passageway (67). 6. The intermediate gear (50) according to any one of claims 1 to 5 , further comprising a cover member (62) capable of covering at least part of the intermediate gear (50) from the outside and forming an oil reservoir inside. Compression ratio variable device.

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