JPS6320802Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a lubricating oil supply device for an internal combustion engine used in vehicles such as automobiles, and particularly in an overhead camshaft type internal combustion engine in which lubricating oil is stored in the upper part of the cylinder head. The present invention relates to a lubricating oil supply device for an internal combustion engine having a section.

In an overhead camshaft type internal combustion engine, lubricating oil is supplied to the valve train installed above the cylinder head through an oil passage formed in the cylinder head to lubricate and cool the valve train. It has an oil supply device. After the lubricating oil supplied to the valve gear completes its lubrication and cooling effects, it returns to the oil pan via the oil return path, but some of it accumulates at the top of the cylinder head, thereby lubricating the top of the cylinder head. Oil stagnation occurs. The lubricating oil in the oil sump is useful for lubricating the valve train, but as the oil level in the oil sump increases, the amount of lubricating oil in the oil pan decreases due to the lubricating oil in the oil sump. However, there is a risk that the supply of lubricating oil may be disrupted. In addition, if the cylinder head cover attached to the upper part of the cylinder head is provided with a blow-by gas extraction port of the blow-by gas reduction device, when the oil level in the oil sump becomes high, the blow-by gas extraction port Lubricating oil is sucked into the blow-by gas recirculation device, so-called lubricating oil suction, which increases the amount of lubricating oil consumed.
Furthermore, the lubricating oil sucked into the blow-by gas reducing device is supplied to the intake system of the internal combustion engine together with the blow-by gas, which may impede the operability of the internal combustion engine.

In view of the above-mentioned problems in conventional internal combustion engine lubricating oil supply systems, this invention prevents the oil level in the lubricating oil sump at the top of the cylinder head from rising beyond a predetermined value. However, it is an object of the present invention to provide an improved lubricating oil supply device for an internal combustion engine that avoids an abnormal reduction in the amount of lubricating oil in the oil pan and the suction of lubricating oil into the blowbus gas reduction device.

According to the present invention, in a lubricating oil supply device for an internal combustion engine having a lubricating oil sump in the upper part of a cylinder head, a lubricating oil supply device is provided in the middle of an oil passage leading to the lubricating oil to the oil sump. This is achieved by a lubricating oil supply device having a valve that responds to the oil level in the oil sump and limits the oil flow rate when the oil level exceeds a predetermined value.

According to this configuration, when the oil level in the oil sump reaches a predetermined value or more, the flow rate of lubricating oil supplied to the oil sump is restricted, so that the oil level in the oil sump reaches the predetermined value. It is avoided that the temperature rises above .

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings.

The attached drawings show the main parts of one embodiment of the lubricating oil supply system for an internal combustion engine according to the present invention. In the figure, reference numeral 1 indicates a cylinder head of an internal combustion engine, and the cylinder head supports a stem 3 of a poppet valve so as to be movable in the vertical direction as shown in the figure, by means of a guide bush 2 attached to the cylinder head. There is. A spring retainer 5 is attached to the tip of the stem 3 by a retainer lock 4, and a compression coil spring 6 is attached between the spring retainer and the cylinder head 1. A cup-shaped valve lifter 7, which is supported by the cylinder head 1 so as to be movable in the vertical direction as shown in the figure, is engaged with the tip of the stem 3, and a disc that engages with a cam 9 is attached to the upper end of the valve lifter 7. shaped pad 8
is provided. The cam 9 is integrally formed with a camshaft 10, and the camshaft 10 is rotatably supported on the cylinder head 1 by a bracket 11.

A cylinder head cover 12 is attached to the upper part of the cylinder head 1 to cover the valve operating device as described above.

The bracket 11 is provided with a lubricating oil supply groove 13 for lubricating the bearing portion of the camshaft 10, and the lubricating oil supply groove includes an oil passage 17 provided in the cylinder head 1, a flow control valve 18, and an oil passage. Lubricating oil is supplied from an oil pan (not shown) via 16, 15, and 14.

The flow control valve 18 has a valve holder 20 inserted into a valve bore 19 formed in the cylinder head 1 and screwed to the cylinder head 1, and the valve holder communicates the valve bore 19 with the oil passage 17. Valve chamber 21
and a valve chamber 22 that communicates with the oil passage 16, and the valve holder 20 has an axial hole 24 and a radial hole 25 that communicate the valve chamber 21 with the valve chamber 22.
and is provided. The valve chamber 21 is provided with a valve element 26 which is connected to the valve holder 20 by a stem 27 extending through the bore 24 as shown in the vertical direction in the figure. It is movably supported between a lowered position where it is separated from the valve seat part 23 on the lower bottom surface of the valve and a raised position where it is seated on the valve seat part 23. The stem 27 projects upwardly from the valve holder 20 at its upper end, and a float 28 is attached to the end. The float 28 is located in an oil sump A where lubricating oil is generated in the upper part of the cylinder head 1, and when the oil level in the oil sump A rises above a predetermined value, the float 28 is moved through the stem 27 by buoyancy. The valve element 26 is adapted to be driven from the lowered position to the raised position. Note that the valve seat portion 23 is provided with a groove 29, which allows the valve element 2
6 is seated on the valve seat portion 23, the communication between the valve chambers 21 and 22 is not completely cut off, and the valve chamber 2
The flow rate of lubricating oil to 2 is restricted or reduced.

According to the above-described configuration, when the oil level in the lubricating oil sump A in the upper part of the cylinder head 1 is below a predetermined value, the valve element 26 is in the lowered position and the valve element 26 is in the lowered position and the lubricating oil is transferred from the valve chamber 21 to the valve chamber 22. Although the flow rate of the lubricating oil is not substantially restricted, when the oil level in the oil sump A rises above a predetermined value, the valve element 26 is driven upward by the float 28 as shown in the figure. As a result, this is seated on the valve seat portion 23, and the flow rate of lubricating oil flowing from the valve chamber 21 to the valve chamber 22 is restricted, and the flow rate of lubricating oil sent to the oil sump portion A is accordingly reduced. This prevents the oil level in the oil sump A from rising beyond a predetermined value, thereby preventing an abnormal reduction in the amount of lubricating oil in the oil pan and preventing the blow-by gas reducing device from sucking lubricating oil.

In the embodiment described above, the valve element 26 is directly driven by the float 28, but the present invention is not limited to this.
The valve element 26 is drivingly connected to a float 28 via a linkage, and may be configured to be driven indirectly by the float 28, and the valve element 26 controls the oil level in the oil sump A. It may be configured to be electrically driven and controlled by a signal from a detected oil level sensor.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited thereto, and various embodiments are possible within the scope of the present invention. It will be clear to those skilled in the art.

[Brief explanation of the drawing]

The attached figure is a longitudinal sectional view showing the main parts of one embodiment of the lubricating oil supply device for an internal combustion engine according to the present invention. 1... Cylinder head, 2... Guide bush, 3... Poppet valve stem, 4... Retainer lock, 5... Valve retainer, 6... Compression coil spring, 7... Valve lifter, 8... Pad, 9
...Cam, 10...Camshaft, 11...Bracket, 12...Cylinder head cover, 13...Lubricating oil supply groove, 14-17...Oil passage, 18...Flow rate control valve, 19...Valve bore , 20... Valve holder, 2
1, 22... Valve chamber, 23... Valve seat, 24, 25
... Hole, 26 ... Valve element, 27 ... Stem, 28
...Float, 29...Groove, A...Oil sump.

Claims (1)

[Scope of utility model registration request] In a lubricating oil supply device for an internal combustion engine that has a lubricating oil sump at the top of the cylinder head, the oil level in the oil sump is lowered in the middle of the oil path that leads the lubricating oil to the oil sump. A lubricating oil supply device having a valve that responds to the oil level and limits the oil flow rate when the oil level is equal to or higher than a predetermined value.