JP7306116B2 - internal combustion engine - Google Patents

Description

The present invention relates to an internal combustion engine having an oil filter in an oil passage.

Patent Document 1 discloses a configuration in which a cam cap is provided with an oil passage for supplying oil to a camshaft. Further, Patent Literature 2 discloses a configuration in which a camshaft is attached to a cylinder head via a bearing.

JP 2016-191307 A JP 2013-204435 A

When the camshaft disclosed in Patent Document 1 is provided with a bearing as disclosed in Patent Document 2, the cross-sectional area of the oil passage provided in the camshaft bearing is compared to the case where the bearing is not provided. is reduced, there is a risk of a lack of hydraulic pressure downstream of the camshaft. Furthermore, if an oil filter that removes impurities contained in the oil is provided in the oil passage, pressure loss will occur in the oil that passes through the oil filter, so there is a risk of a further shortage of hydraulic pressure downstream of the oil filter. If the output of the oil pump is increased in consideration of such pressure loss, the size of the oil pump becomes large, and there is a problem that the cost and mass increase.

The present invention provides an internal combustion engine having a camshaft provided with bearings, in which an oil filter is provided in an oil passage provided in the camshaft bearing, and the oil pressure downstream of the oil passage can be controlled without increasing the cost and weight. It was created to fill the gap.

In order to solve the above problems, the present invention provides two camshafts rotatably supported between a cylinder head and a cam cap, and at least one rotary sliding portion of the camshafts. A bearing provided with an oil hole communicating with a rotating sliding portion, an oil groove provided in the bearing portion of the cam cap and communicating with the outer peripheral portion of the bearing, and an oil provided inside the cylinder head through which the oil flows. An internal combustion engine comprising: a passageway; a connecting passageway that connects an end portion of the oil passageway; the oil hole and the oil groove; and an oil filter that filters impurities from the oil, wherein the oil filter Provided at a connecting portion between the passage and the connecting flow path, and protruding toward the connecting flow path, the connecting flow path allows oil to flow through a space between the upper surface of the projecting portion and the inner wall of the connecting flow path. Provided is an internal combustion engine characterized by having a first flow path for the flow and a second flow path for the rest.

According to the above configuration, the oil pressure loss in the connection flow path is reduced, and the shortage of oil downstream of the oil path can be suppressed.

1 is a schematic side view of an internal combustion engine with a chain case removed according to an embodiment of the present invention; FIG. 1 is a diagram schematically showing the upper surface of an internal combustion engine according to an embodiment of the present invention with a cylinder head cover removed; FIG. 3 is a cross-sectional view along line AA in FIG. 2; FIG. FIG. 4 is a cross-sectional view along line BB in FIG. 3;

An embodiment of an internal combustion engine according to the present invention will be described with reference to the drawings. In the following description, it is assumed that the internal combustion engine is mounted on a vehicle, and the vertical direction of the vehicle is the vertical direction of the internal combustion engine.

First, according to FIGS. 1 and 2, a schematic configuration of an internal combustion engine 1 of this embodiment will be described. FIG. 1 is a schematic side view of an internal combustion engine 1 with a chain case removed. FIG. 2 is a schematic top view of the internal combustion engine 1 with the cylinder head cover removed.

As shown in FIG. 1, the internal combustion engine 1 comprises a cylinder block 11, a cylinder head 12, a cylinder head cover 13 and an oil pan .

Cylinder block 11 rotatably supports crankshaft 40 . A crank sprocket 41 is fixed to the end of the crankshaft 40 on one side in the axial direction (the front side in FIG. 1). In addition, in FIG. 1 , the crank sprocket 41 is schematically indicated by a circle.

A plurality of cam caps 30 are fixed to the cylinder head 12 as shown in FIG. An exhaust side camshaft 60 and an intake side camshaft 70 are rotatably supported between the cylinder head 12 and the cam cap 30 .

As shown in FIG. 1, an exhaust-side variable valve timing mechanism 600 having a substantially disc shape is attached to one end of the exhaust-side camshaft 60 in the axial direction (the front side in FIG. 1). An exhaust-side cam sprocket 601 is attached to the outer periphery of the exhaust-side variable valve timing mechanism 600 . In FIG. 1, the exhaust-side cam sprocket 601 is schematically indicated by a circle.

An intake-side variable valve timing mechanism 700 having a substantially disk shape is attached to one end of the intake-side camshaft 70 in the axial direction (the front side of the paper in FIG. 1). An intake-side cam sprocket 701 is attached to the outer circumference of the intake-side variable valve timing mechanism 700 . In addition, in FIG. 1, the intake-side cam sprocket 701 is schematically indicated by a circle.

The cylinder head cover 13 covers most of the exhaust side camshaft 60, most of the intake side camshaft 70, and the plurality of cam caps 30 from above.

The oil pan 14 has a bottomed box shape and is provided at the lower end of the cylinder block 11 so as to cover the crankshaft 40 from below. The oil pan 14 contains oil for lubricating various parts of the internal combustion engine 1 and for operating various mechanisms. Further, an oil pump 20 is housed inside the oil pan 14 for pumping the oil housed in the oil pan 14 . A substantially disk-shaped oil pump sprocket 22 is fixed to the end of the input shaft 21 of the oil pump 20 . In addition, in FIG. 1 , the oil pump sprocket 22 is schematically indicated by a circle.

A timing chain 80 is wound around the crank sprocket 41 , the exhaust cam sprocket 601 and the intake cam sprocket 701 . In this embodiment, the crank sprocket 41 rotates clockwise when viewed from one side of the crankshaft 40 in the axial direction (the front side of the sheet of FIG. 1). Then, the timing chain 80 sent out from the crank sprocket 41 travels through the exhaust side cam sprocket 601, the intake side cam sprocket 701, and returns to the crank sprocket 41 again.

A pump chain 90 is wound around the crank sprocket 41 and the oil pump sprocket 22 . Therefore, when the crankshaft 40 of the internal combustion engine 1 rotates, the rotational force is transmitted to the oil pump 20 via the crank sprocket 41 , the pump chain 90 and the oil pump sprocket 22 .

In the internal combustion engine 1, an oil passage 130 is formed through which oil pumped by the oil pump 20 flows. In addition, the oil passage 130 is configured by a tubular passage (piping) and passages provided in the cylinder block 11 and the cylinder head 12 . The upstream end of the oil passage 130 is connected to the oil pump 20 , and the downstream end communicates with the inside of the oil pan 14 .

Next, the oil passage 130 near the exhaust side camshaft 60 of this embodiment will be described in detail with reference to FIGS. 3 is a cross-sectional view along line AA of FIG. 2. FIG. FIG. 4 is a cross-sectional view along line BB of FIG.

As shown in FIG. 3 , an oil passage 130 near the exhaust camshaft 60 is composed of an oil passage 131 provided in the cylinder head 12 and a connection passage 132 provided in the cam cap 30 .

The oil passage 131 is formed by a passage provided inside the cylinder head 12, through which the oil pumped by the oil pump 20 flows.

The connection flow path 132 is provided inside the cam cap 30 and supplies oil to the exhaust side camshaft 60 . The connection flow path 132 has a groove shape that opens toward the exhaust side camshaft 60 side. The upper end portion of the oil passage 131 is connected so as to be continuous with the side surface of the connecting passage 132 having a groove shape, and communicates vertically at the connecting portion.

Next, a connecting portion that connects the upstream side and the downstream side of the exhaust-side camshaft 60 of the connecting passage 132 will be described.

As shown in FIG. 3, a bearing 200 is attached between the rotary sliding portion 61 of the exhaust camshaft 60 and the bearing portion 31 (see FIG. 4) of the cam cap 30 to reduce friction. .

A connecting portion connecting the upstream side and the downstream side of the exhaust-side camshaft 60 of the connecting passage 132 is provided in the groove 62 provided in the rotary sliding portion 61 of the exhaust-side camshaft 60 and the bearing 200 communicating with the groove 62. and a cam cap oil groove 32 provided in the bearing portion 31 of the cam cap 30 .

As shown in FIG. 3 , part of the oil flowing from the connection flow path 132 passes through the oil hole 201 provided in the bearing 200 and flows through the groove 62 provided in the rotary sliding portion 61 of the exhaust camshaft 60 . distributed to

The bearing portion 31 of the cam cap 30 is provided with a cam cap oil groove 32 for flowing oil flowing from the connection flow path 132 . The cam cap oil groove 32 is radially outward of the bearing 200 and connects the upstream side and the downstream side of the exhaust side camshaft 60 of the connection passage 132 .

As shown in FIG. 3, the oil filter 300 is made of wire mesh and formed in a cylindrical shape with a bottom. are in communication. The oil filter 300 is provided at the connection portion 133 between the connection flow path 132 and the oil passage 131 . It is inserted from the connecting passage 132 toward the oil passage 131 so as to be sandwiched between the oil passage 131 and protrudes toward the connecting passage 132 so that the upper surface 302 of the projecting portion 301 and the inner wall 132a of the connecting passage 132 are formed. Oil is circulating between

Since the oil flows between the upper surface 302 of the protruding portion 301 and the inner wall 132a of the connection flow path 132, the oil flowing into the oil filter 300 (F1 in FIG. 3) It is divided into F2 and F3) in 3).

The oil that has flowed in the F2 direction mainly flows through the connection flow path 132 , the oil hole 201 provided in the bearing 200 , and the groove 62 of the exhaust camshaft 60 .

Since the oil that has flowed in the F3 direction tends to flow mainly along the oil that has flowed in the F2 direction, it flows along the upper wall surface of the cam cap 30 and flows into the cam cap oil groove 32 .

Since the oil flows between the upper surface 302 of the projecting portion 301 and the inner wall 132a of the connecting passage 132, the oil flows into the cam cap oil groove 32 and downstream of the camshaft. easier. Therefore, the shortage of oil on the downstream side of the exhaust-side camshaft 60 in the connection passage 132 can be suppressed.

The above embodiment can be modified and implemented as follows. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

For example, in the above-described embodiment, the exhaust side camshaft 60 provided with the cam bearing is provided upstream of the connection flow path 132, and the intake side camshaft 70 is provided downstream thereof, but the present invention is not limited to this. The intake side camshaft 70 having cam bearings may be provided upstream of the connection flow path 132 and the exhaust side camshaft 60 may be provided downstream thereof.

In addition, in the above-described embodiment, the oil filter 300 for oil is merely processed with a wire mesh or the like, but it is not limited to this. It is also possible to arrange elements made of non-woven fabric inside.

DESCRIPTION OF SYMBOLS 1... Internal combustion engine 12... Cylinder head 20... Oil pump 30... Cam cap 32... Cam cap oil groove 60... Exhaust side camshaft 61... Rotary sliding part 70... Intake side camshaft 130... Oil passage 131... Oil passage 132... Connection flow path 132a Inner wall 133 Connecting portion 200 Bearing 201 Oil hole 300 Oil filter 301 Protruding portion 302 Upper surface

Claims (1)

two camshafts rotatably supported between the cylinder head and the cam cap;
a bearing provided in at least one rotary sliding portion of the camshaft and having an oil hole communicating with the rotary sliding portion;
an oil groove provided in a bearing portion of the cam cap and communicating with an outer peripheral portion of the bearing;
an oil passage provided inside the cylinder head through which oil flows;
a connection flow path connecting an end portion of the oil passage and the oil hole and the oil groove;
an oil filter for filtering impurities from the oil;
In an internal combustion engine comprising
The oil filter is provided at a connection portion between the oil passage and the connection flow path, and protrudes toward the connection flow path,
The connection flow path has a first flow path through which oil flows between the upper surface of the projecting portion and the inner wall of the connection flow path, and a second flow path other than the first flow path,
The second flow path is a flow path leading to the oil hole, and the first flow path is a flow path different from the second flow path and leading to the oil groove. internal combustion engine.

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