JPH0521127U - Oil jet device for piston cooling - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a device for cooling and lubricating by jetting an appropriate amount of lubricating oil to the lower surface of a piston to supply oil to a piston pin, connecting rod, etc. even during idle operation of an engine. [Structure] A piston cooling system in which a check valve 3 that opens and closes according to the oil pressure of an oil gear rally 1 is a two-stage open / close type that opens at a low oil pressure, and a cap member 9 whose opening cross-sectional area changes with the oil pressure at the nozzle tip 2 is mounted. Oil jetting device for.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an oil jet device for cooling a piston that injects lubricating oil of a diesel or gasoline combustion type internal combustion engine from an oil jet nozzle to the lower surface of the piston to prevent overheating of the piston.

[0002]

[Prior Art]

 Among internal combustion engines, particularly in an internal combustion engine in which fuel is sprayed directly toward the combustion chamber formed on the upper surface of the piston, in order to reduce the heat load of the piston under high load, the piston is directed toward the lower surface of the piston below the piston. An oil jet device with a nozzle tip that injects lubricating oil is provided.

A conventional example having such an oil jet device will be described. As shown in FIG. 5 and FIG. 6 which is a partially enlarged view of this figure, the lower surface of the piston 10 of the internal combustion engine is lubricated from the nozzle tip 2 to The oil L is jetted to cool the piston 10. In this case, the check valve 3 at the other end of the spring 4 whose one end is supported by the retainer 5 in the bolt 6 by the oil pressure of the oil gallery 1 Press to open the valve. The check valve 3 is opened to inject the lubricating oil L from the nozzle tip 2 when the oil pressure of the oil gallery 1 reaches a certain set pressure, for example, usually 2 kg / cm ² or more.

The reason why the opening pressure of the check valve 3 is adjusted in this way is to prevent the hydraulic pressure and the oil amount from dropping too low when the hydraulic pressure and the oil amount are small, such as when the engine is idle. is there. By adjusting the valve opening pressure of the check valve 3 in this manner, it is possible to avoid sacrificing the oil supply to the main bearing, connecting rod bearing, etc. of the internal combustion engine.

However, when the internal combustion engine is idle, the pressure of the lubricating oil L does not rise sufficiently so that it is often not injected to the optimum position in the direction of the piston 10, and if left in an idle state for a very long time, There is a problem that oil supply to the piston pin 12 and the connecting rod bush 13 may be insufficient, causing abnormal wear of those parts.

On the other hand, as a piston cooling device that adjusts the valve opening pressure of a check valve in accordance with the supply pressure of lubricating oil, a piston cooling device is slid between the check valve and a fixed spring receiver along the displacement direction of the check valve. A moving piston member is provided, a first compression spring is interposed between the piston member and the check valve, and a second compression spring is interposed between the piston member and the fixed spring receiver. A device of Japanese Utility Model Application Laid-Open No. 59-141122, in which the spring constant is set smaller than the second compression spring constant, has been proposed.

[0007] However, the above-mentioned invention has a problem to be solved in which the check valve is fully opened at the maximum load and the urging force of the compression spring is returned to the original state at the time of low rotation to prevent the lubricant oil jet from the oil jet nozzle. However, unlike the present invention, it is not a problem to be solved to properly eject the lubricating oil to the piston even at a low speed such as idling.

Further, an injection port forming member that changes the injection cross-sectional area in the injection direction in a substantially constant manner is provided at the tip injection part of the oil injection nozzle, and the injection port is expanded in the high temperature region. An invention of Japanese Utility Model Laid-Open No. 63-126516, which relates to a piston cooling device in which an injection port is throttled in a low temperature region, has been devised. However, in this device, since the injection port forming member has a closed shape with an injection cross-sectional area of zero at the low temperature immediately after the engine is started, when the engine, which has not been used for a long period of time, is used, such as a piston or connecting rod bush. There is a problem of insufficient oil supply to the lubrication required parts.

Therefore, as shown in FIG. 6, a small hole 14 for bypassing the lubricating oil L from the oil gallery 1 to the nozzle tip 2 side is bored in the portion of the bolt 6 of the check valve 3 so that the lubricating oil L can be supplied even at a low pressure. A device that allows the oil to flow to the nozzle tip 2 has also been proposed. However, in this device, the lubricating oil L is squeezed by the small hole 14 and supplied, so that the hydraulic pressure decreases and the nozzle tip 2 causes the piston 10 to flow. There is a risk that the jet force to the

[0010]

[Problems to be solved by the invention]

 The present invention has been made in order to solve the problems of the above-mentioned conventional device. Even when the internal combustion engine is idling, an appropriate amount of lubricating oil is jetted to the bottom surface of the piston to provide the piston pin. It is a problem to be solved to provide an oil jet device for piston cooling capable of supplying oil to a connecting rod bush or the like.

[0011]

[Means for Solving the Problems]

 The present invention for solving the above-mentioned problems is an oil jet device having a nozzle for injecting lubricating oil to the lower surface of a piston via a check valve that opens and closes according to the oil pressure of an oil gallery, wherein the check valve is It has a two-stage open / close type valve structure consisting of a first piston that opens at low pressure and a second piston that opens when this first piston opens and is in a connected state. A cap member made of an elastic material whose opening cross-sectional area changes due to hydraulic pressure is mounted.

[0012]

[Work]

 Since the check valve has a two-stage open / close type valve structure, it opens even when the hydraulic pressure is low, such as during idle, to supply lubricating oil to the nozzle. On the other hand, since a cap member that changes the opening area by hydraulic pressure is provided at the tip of the nozzle, this cap member closes and has a small opening when the hydraulic pressure is low such as during idling. However, it is ejected as a droplet and oil is applied to the piston pin and the connecting rod bushing with oil droplets to prevent abnormal wear due to insufficient oil.

[0013]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of an embodiment of an oil jet device for cooling a piston of the present invention, which device is similar to the conventional example of FIG. Lubricating oil L is jetted from the nozzle tip 2 toward the lower surface of the piston 10 of the internal combustion engine to cool the piston 10, and the piston pin 12 and the connecting bush 13 are also lubricated.

Therefore, in the check valve 3 that opens and closes according to the oil pressure of the oil gallery 1 of the internal combustion engine, the first piston 7 that slides in the bolt 6 of the check valve 3 and the first piston 7 A second piston 8 that is in a connected state is provided, and a first spring 15 having a small set force and a small spring constant and relatively low elasticity is incorporated between the first piston 7 and the retainer 5. Further, between the second piston 8 and the retainer 5, a second spring 16 provided with a large set force corresponding to, for example, 2 kg / cm ² is incorporated.

As described above, the strengths of the springs 15 and 16 are made different, and the two pistons 7 and 8 are housed in the springs 15 and 16, respectively, and the check valve is a two-stage open type. When the oil pressure is low during idling, the first piston 7 moves until it hits the second piston 8, and a small amount of lubricating oil is supplied to the nozzle tip 2. Further, at the time of medium / high speed rotation, the second piston 8 is integrally moved together with the first piston 7 so that normal injection can be performed.

Further, even when the hydraulic pressure is low, the nozzle tip 2 communicating with the check valve 3 is opened in a throttled state by the opening cross sectional area of about FIG. 4, and when the hydraulic pressure is high, the opening cross sectional area is fully opened as shown in FIG. The cap member 9 shown in the vertical sectional view of FIG. 2 and the plan view of FIG. 3 made of an elastic material such as changing rubber is attached. When the internal pressure of the internal combustion engine equipped with the oil jet device configured as described above is low, such as during idling, when the oil pressure is low, the oil pressure lowers the first piston 7 until it hits the second piston 8. The lubricating oil L is supplied to the nozzle tip 2. On the other hand, since the cap member 9 which is made of an elastic material such as rubber at the nozzle tip 2 and whose opening area is changed by the hydraulic pressure is provided, the lubricating oil L is kept closed even at a low hydraulic pressure even at a low hydraulic pressure. As a splash, oil is supplied to the piston pin 12, the rod bush 13 and the like.

Next, when the engine is in the middle / high speed rotation, its hydraulic pressure is high, so the first piston 7 and the second piston 8 move in a connected state, and the check valve 3 is fully opened. At this time, the cap member 9 has a large opening cross-sectional area as shown in FIG. 5, and while the lubricating oil L is given a resistance to close the opening of the cap member 9, a normal oil jet flow rate is obtained. Then, it vigorously ejects from the nozzle tip 2 toward the lower surface of the piston 10 to cool the piston 10 and the like.

FIG. 6 shows another embodiment, which has a structure in which a backup ring 17 made of steel or the like is fitted in a cap member 9 made of an elastic material such as rubber. According to this structure, the back surface of the cap member 9 is supported by the backup ring 17 when the pressure is high, and it is possible to prevent the opening cross section of the cap member 9 from being left open due to the fatigue of the rubber.

[0019]

[Effect of the device]

 An oil jet device for cooling a piston according to the present invention is an oil jet device having a nozzle for injecting lubricating oil to a lower surface of a piston through a check valve that opens and closes according to oil pressure of an oil gallery. Has a two-stage open / close type valve structure consisting of a first piston that opens at low pressure and a second piston that opens when the first piston opens and is in a connected state. In addition, a cap member made of an elastic material whose opening cross-sectional area changes due to hydraulic pressure is attached.

Therefore, even when the engine is idle, oil is supplied to the piston pin, connecting rod bush, etc. within the range in which the hydraulic pressure is not reduced as much as possible, so abnormal wear due to lack of oil on the piston pin, connecting rod, etc. can be prevented. There is. In particular, in the present invention, the cap member whose opening cross-sectional area changes due to hydraulic pressure is attached to the nozzle tip, so even at low pressure, the oil is sprayed as a droplet and is sufficiently ejected to the bottom surface of the piston, which has the advantage of providing the oil supply effect. There is.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part of an oil jet device for cooling a piston according to the present invention.

FIG. 2 is an enlarged vertical sectional view of the cap member of FIG.

FIG. 3 is a plan view of FIG.

FIG. 4 is an explanatory diagram of a state of the cap member of FIG. 2 when the hydraulic pressure is low.

FIG. 5 is an explanatory diagram of a state of the cap member of FIG. 2 at high hydraulic pressure.

FIG. 6 is a longitudinal sectional view of a main part of another embodiment in which a backup ring is fitted to the cap member of FIG.

FIG. 7 is a vertical cross-sectional view of a main part showing a piston including a conventional oil jet device.

8 is an enlarged vertical sectional view of the oil jet device of FIG.

[Explanation of symbols]

1 Oil gallery 2 Nozzle tip 3 Check valve 7 First piston 8 Second piston 9 Cap member 10 First spring 11 Second spring.

Claims (1)

[Scope of utility model registration request] 1. An oil jet device having a nozzle for injecting lubricating oil to the lower surface of a piston via a check valve that opens and closes according to the oil pressure of an oil gallery, wherein the check valve opens at a low pressure. It has a two-stage open / close type valve structure consisting of a piston and a second piston that opens when the first piston opens and is in a connected state. Furthermore, the opening cross-sectional area changes at the tip of the nozzle due to hydraulic pressure. An oil jet device for cooling a piston equipped with a cap member made of an elastic material.