JPH08270443A - Piston cooling device for internal combustion engine - Google Patents

Abstract

PURPOSE: To protect a piston, cylinder walls, and the like from overheat by jetting lubricating oil, discharged from an oil pump, toward the back face of the piston from oil jet nozzles provided cylinder by cylinder, through a nozzle through hole. CONSTITUTION: At the time of low rotation of an engine where the discharge pressure of an oil pump 1 is lower than the specified value, a hydraulic valve 15 is closed, and the jet of lubricating oil from each oil jet nozzle 10 is stopped. At this time, the lubricating oil discharged from the pump 1 is partially fed to each main bearing 8 from a main gallery 6, and the remaining lubricating oil is fed to a valve system 9 from a head gallery 7. When the pump discharge pressure rises exceeding the specified value at the time of high rotation, a valve body moves against a return spring, and the valve 15 is opened. Part of lubricating oil is thereby fed to the oil jet nozzles 10 through an oil jet gallery 11, and the lubricating oil jetted from the oil jet nozzles 10 comes in contact with the back face of a piston to take away heat so as to prevent the overheat of the piston, cylinders, and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a piston cooling device for injecting lubricating oil into a piston of an internal combustion engine.

[0002]

2. Description of the Related Art As a conventional piston cooling device for an internal combustion engine, there is one having an oil jet 80 for injecting lubricating oil toward a piston 83 as shown in FIG. Silvia S14
Type car B-12 tribute October 1993 Nissan Motor Co., Ltd.).

The nozzle 82 of the oil jet 80 is arranged toward the piston 83, and the nozzle 82 is provided with a hydraulic valve 84.
Through an oil gallery 85 formed on the cylinder block 81.

The hydraulic valve 84 opens in response to the hydraulic pressure introduced from the oil gallery 85 at a high speed of a predetermined number of revolutions or more, and the lubricating oil is injected from the nozzle 82 toward the piston 83 as shown by the arrow in the figure, This lubricating oil removes heat from the piston 83 and the cylinder bore.

[0005]

However, in such a conventional system, since the hydraulic valve 84 is provided for each oil jet 80, it is necessary to mount the oil jet 80 on the cylinder block 81. The problem is that the number of parts increases and productivity is poor.

In view of the above problems, the present invention has an object to simplify the structure of a piston cooling device for an internal combustion engine.

[0007]

According to a first aspect of the present invention, there is provided a piston cooling device for an internal combustion engine, which has a nozzle through hole which is opened in an engine body and through which lubricating oil discharged from an oil pump is introduced, and a nozzle through hole which communicates with the nozzle through hole. And a pipe-shaped oil jet nozzle for injecting lubricating oil to the piston, a bracket fastened to the engine body, a coupling means for coupling the oil jet nozzle and the bracket to each other, and an oil jet nozzle formed integrally with the engine. And a nozzle base end portion that is inserted into a nozzle through hole of the main body.

According to a second aspect of the invention, there is provided a piston cooling device for an internal combustion engine according to the first aspect of the present invention, wherein the coupling means includes retaining means for retaining the oil jet nozzle from the bracket, and the bracket. A notch is formed in the middle of the oil jet nozzle.

According to a third aspect of the present invention, in the piston cooling device for an internal combustion engine according to the first or second aspect of the invention, an annular projection portion that annularly protrudes is formed in the middle of the oil jet nozzle as retaining means. Nozzle fitting holes are formed in the bracket to engage the annular protrusions and prevent the oil jet nozzle from coming off.

A piston cooling device for an internal combustion engine according to a fourth aspect is the oil jet system according to any one of the first to third aspects, in which the lubricating oil discharged from the oil pump is provided for each cylinder. An oil jet gallery that is guided to the nozzle through the nozzle through hole and a hydraulic valve that opens the oil jet gallery as the discharge pressure of the oil pump increases.

[0011]

In the piston cooling device for the internal combustion engine according to the first aspect, the lubricating oil discharged from the oil pump is injected from the oil jet nozzle provided for each cylinder through the nozzle through hole. Lubricating oil injected from the oil jet nozzle hits the back surface of the piston, removes heat from the piston, and prevents the piston, the cylinder wall, and the like from being overheated.

By inserting the nozzle base end portion of the oil jet nozzle into the nozzle through hole of the engine body, the bracket is fixed to the engine body at two points, that is, its fastening portion by a bolt or the like and the nozzle base end portion. Is positioned. Therefore, when installing the oil jet nozzle to the engine body, without using a plurality of bolts or positioning knock pins,
Since the oil jet nozzle is positioned, the number of parts can be reduced and the structure can be simplified.

In the piston cooling device for an internal combustion engine according to a second aspect of the present invention, the rotation of the oil jet nozzle with respect to the bracket is reliably locked due to the structure in which the middle of the oil jet nozzle engages with the cutout portion, which improves productivity and productivity. Quality can be improved.

In the piston cooling device for an internal combustion engine according to a third aspect of the present invention, the annular projection of the oil jet nozzle is fitted into a nozzle fitting hole opened in the bracket to prevent the oil jet nozzle from coming off from the bracket. Is done. As a result, it is not necessary to fix the oil jet nozzle to the bracket by brazing or caulking, and productivity can be improved.

In the piston cooling device for an internal combustion engine according to a fourth aspect of the present invention, when the discharge pressure of the oil pump is lower than a predetermined value, the hydraulic valve is closed to prevent the lubricating oil from each oil jet nozzle from closing. The injection is stopped.

When the discharge pressure of the oil pump rises above a predetermined value when the engine rotates at high speed, the hydraulic valve opens. As a result, part of the lubricating oil discharged from the oil pump is supplied from the oil jet gallery to the oil jet nozzle via the nozzle through hole provided for each cylinder.

By controlling the injection of the lubricating oil from the oil jet nozzle of each cylinder via a single hydraulic valve, it is not necessary to provide a hydraulic valve or the like for each cylinder as in the conventional device.

[0018]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 5, the constant capacity oil pump 1 driven by the engine sucks up the lubricating oil stored in the oil pan 2 through the strainer 3.

The lubricating oil discharged from the oil pump 1 is
It is divided into three systems such as a main gallery 6, a head gallery 7 and an oil jet gallery 11 via a relief valve 4 and an oil filter 5.

The lubricating oil distributed to the main gallery 6 is
It is supplied to each main bearing 8 which supports a crankshaft (not shown).

The lubricating oil distributed to the head gallery 7 is
It is supplied to a valve operating mechanism 9 composed of a camshaft, intake / exhaust valves and the like.

The lubricating oil distributed to the oil jet gallery 11 through the hydraulic valve 15 is supplied to each oil jet nozzle 10.

The hydraulic valve 15 is opened during high speed operation in which the discharge pressure P of the oil pump 1 rises above a predetermined value, and a part of the lubricating oil discharged from the oil pump 1 passes through the oil jet gallery 11. Is supplied to each oil jet nozzle 10 provided for each cylinder.

As shown in FIG. 1, each oil jet nozzle 10 is arranged toward the back surface of each piston 21 for each cylinder of a four-cylinder engine. The lubricating oil injected from the oil jet nozzle 10 hits the back surface of the piston 21 and removes the heat of the piston 21 and the cylinder wall 22.

As shown in FIG. 2, a bracket 16 for fastening the oil jet nozzle 10 to the cylinder block 20.
Is provided. Each bracket 16 is a cylinder block 2
It is fastened via a single bolt 17 which is screwed to zero.

In FIGS. 1 and 2, 8 is a main bearing that rotatably supports the crankshaft of the cylinder block 20, and 32 is a locus of the crankshaft.

As shown in FIGS. 3 and 4, the oil jet nozzle 10 includes a nozzle base end portion 10c which is inserted into the bracket 16 and the cylinder block 20 by bending a pipe-shaped pipe material into a cono shape, and lubrication. A nozzle tip portion 10a that ejects oil and a nozzle conduit portion 10b that connects the nozzle base portion 10c and the nozzle tip portion 10a are integrally formed.

The nozzle tip portion 10a is formed by tapering the tip portion of the oil jet nozzle 10 by drawing.

The bracket 16 has a nozzle fitting hole 25 through which the oil jet nozzle 10 penetrates and a bolt hole 24 into which the bolt 17 is inserted. The bracket 16 is integrally formed by pressing a sheet metal.

As a connecting means for connecting the middle of the oil jet nozzle 10 to the bracket 16, the middle of the oil jet nozzle 10 is fixed to the bracket 16 by brazing. The nozzle base end portion 10c of the oil jet nozzle 10 may be fixed to the bracket 16 by caulking.

The cylinder block 20 includes a bracket 1
A mounting seat 28 for 6 is formed. A screw hole 27 into which the bolt 17 is screwed is formed in the mounting seat 28, and a nozzle through hole 26 into which the nozzle base end portion 10c of the oil jet nozzle 10 is fitted is formed. Nozzle through hole 2
6 is open to the oil jet gallery 11.

With the above construction, the operation will be described.

When the discharge pressure P of the oil pump 1 is lower than a predetermined value and the engine is running at low speed, the hydraulic valve 15 is closed and the injection of the lubricating oil from each oil jet nozzle 10 is stopped. At this time, the lubricating oil discharged from the oil pump 1 passes through the oil filter 5 and is filtered, then a part of the lubricating oil is supplied from the main gallery 6 to the main bearings 8, and the rest is operated by the head gallery 7 to operate the valve. It is supplied to the mechanism 9.

When the discharge pressure P of the oil pump 1 rises above a predetermined value when the engine rotates at a high speed, the valve body 16 moves while compressing the return spring 7 and the hydraulic valve 15 opens. As a result, a part of the lubricating oil discharged from the oil pump 1 is supplied to the oil jet nozzle 10 provided for each cylinder through the oil jet gallery 11. The lubricating oil sprayed from each oil jet nozzle 10 hits the back surface of the piston 21 and removes the heat of the piston 21, preventing the piston 21 and the cylinder wall from being overheated when the load is high.

By controlling the injection of the lubricating oil from the oil jet nozzle 10 of each cylinder via the single hydraulic valve 15, it is not necessary to provide a hydraulic valve or the like for each cylinder as in the conventional device.

The lubricating oil guided to the oil jet gallery 11 flows into the oil jet nozzle 10 inserted into each nozzle through hole 26 and is jetted from the nozzle tip portion 10a of the oil jet nozzle 10 toward the rear surface of the piston 21. It The nozzle tip portion 10a is tapered to increase the speed of the lubricating oil sprayed from the nozzle tip portion 10a so that the lubricating oil reaches the back surface of the piston 21 with a predetermined force.

When the nozzle base end portion 10c of the oil jet nozzle 10 is inserted into the nozzle through hole 26 of the cylinder block 20, the bracket 16 is fixed to the nozzle base end portion 1.
The oil jet nozzle 10 is positioned by being fixed to the cylinder block 20 at two points, that is, the fastening portion by the bolt 0 and the bolt 0c. Therefore, the oil jet nozzle 1
When the 0 is attached to the cylinder block 20, the oil jet nozzle 10 is positioned without using a plurality of bolts, knock pins for positioning, etc., so that the number of parts can be reduced and the structure can be simplified.

Next, another embodiment shown in FIGS. 6 and 7 will be described. It should be noted that the same parts as those in FIG.

The oil jet nozzle 1 is attached to the bracket 46.
A cutout portion 47 that engages with the No. 0 nozzle conduit portion 10c is formed. The bracket 46 is for the oil jet nozzle 10
And a bolt hole 24 through which the bolt 17 is inserted are opened. The bracket 46 is formed by pressing a sheet metal.

As a retaining means for retaining the oil jet nozzle 10 to the bracket 46, the oil jet nozzle 10 is fixed to the bracket 46 by brazing in the middle thereof. The nozzle base end portion 10c of the oil jet nozzle 10 may be fixed to the bracket 46 by caulking.

Also in this case, the nozzle base end portion 10c of the oil jet nozzle 10 is inserted into the nozzle through hole 26 of the cylinder block 20, so that the oil jet nozzle 10 is positioned through the single bolt 17.

The oil jet nozzle 10 has a structure in which the nozzle conduit portion 10c of the oil jet nozzle 10 is engaged with the notch portion 47, so that the rotation of the oil jet nozzle 10 with respect to the bracket 46 is securely locked, and the productivity and quality are improved.

Next, still another embodiment shown in FIG. 8 will be described. It should be noted that the same parts as those in FIG. 6 will be described using the same reference numerals.

The oil jet nozzle 10 has a structure in which the nozzle conduit portion 10c is engaged with the notch portion 47, so that the rotation of the oil jet nozzle 10 with respect to the bracket 56 is reliably locked.

As a retaining means for retaining the oil jet nozzle 10 from the bracket 46, an annular protrusion 10d that bulges in an annular shape is formed by bulging in the middle of the nozzle base end portion 10c of the oil jet nozzle 10. On the other hand, an annular recess 57 is formed at the opening end of the bracket 46 nozzle fitting hole 25 on the side to be joined to the cylinder block 20.

The oil jet nozzle 10 is attached to the bracket 5
The oil jet nozzle 10 is bent while being inserted into the nozzle fitting hole 25 of No. 6.

In this case, the bracket 56 is fastened to the cylinder block 20 via the bolt 17,
The oil jet nozzle 10 has its annular projection 10 d fitted into the annular recess 57 of the bracket 46, and the nozzle base end portion 1
Axial positioning with respect to the 0c bracket 56 is performed. As a result, it is not necessary to fix the oil jet nozzle 10 to the bracket 56 by brazing or crimping, and the productivity can be improved.

[0049]

As described above, in the piston cooling device for the internal combustion engine according to the first aspect of the present invention, when the oil jet nozzle is attached to the engine body, the oil jet nozzle is not required to use a plurality of bolts or positioning knock pins. Since the jet nozzle is positioned, the number of parts can be reduced and the structure can be simplified.

In the piston cooling device for the internal combustion engine according to the second aspect of the present invention, the rotation of the oil jet nozzle with respect to the bracket is reliably locked due to the structure in which the middle of the oil jet nozzle engages with the notch, so that productivity is improved. And quality can be improved.

In the piston cooling device for an internal combustion engine according to a third aspect of the present invention, the oil jet nozzle has a structure in which the annular projection of the oil jet nozzle is fitted in the nozzle fitting hole opened in the bracket. Productivity can be increased without the need to attach or fix by caulking.

In the piston cooling device for an internal combustion engine according to a fourth aspect of the present invention, the injection of the lubricating oil from the oil jet nozzle of each cylinder is controlled via a single hydraulic valve, so that the conventional device is provided. It is not necessary to provide a hydraulic valve or the like for each cylinder.

[Brief description of drawings]

FIG. 1 is a sectional view of an engine showing an embodiment of the present invention.

FIG. 2 is a plan view of a cylinder block, an oil jet nozzle and the like.

FIG. 3 is a sectional view of an oil jet nozzle and the like.

FIG. 4 is a plan view of an oil jet nozzle and the like.

FIG. 5 is a system diagram of the same.

FIG. 6 is a sectional view of an oil jet nozzle or the like showing another embodiment.

FIG. 7 is a sectional view of an oil jet nozzle and the like.

FIG. 8 is a sectional view of an oil jet nozzle and the like showing still another embodiment.

FIG. 9 is a sectional view of an engine showing a conventional example.

[Explanation of symbols]

 1 Oil Pump 2 Oil Pan 4 Relief Valve 5 Oil Filter 6 Main Gallery 7 Head Gallery 9 Valve Mechanism 10 Oil Jet Nozzle 10a Nozzle Tip 10b Nozzle Conduit 10c Nozzle Base 10d Annular Projection 11 Oil Jet Gallery 15 Hydraulic Valve 16 bracket 17 bolt 20 cylinder block 21 piston 24 bolt insertion hole 25 nozzle fitting hole 26 nozzle passage hole 27 bolt hole 46 bracket 47 notch portion 56 bracket 57 annular recess

Claims (4)

[Claims] 1. A nozzle through hole which is opened in an engine main body and through which lubricating oil discharged from an oil pump is introduced; and a pipe-shaped oil jet nozzle which is in communication with the nozzle through hole and injects lubricating oil to a piston. A bracket that is fastened to the engine body, a coupling means that couples the oil jet nozzle and the bracket to each other, and a nozzle base end that is integrally formed with the oil jet nozzle and that is inserted into a nozzle through hole of the engine body. A piston cooling device for an internal combustion engine. 2. The connecting means is provided with retaining means for retaining the oil jet nozzle with respect to the bracket, and the bracket is formed with a notch portion that engages in the middle of the oil jet nozzle. A piston cooling device for an internal combustion engine according to claim 1. 3. As a retaining means, an annular protrusion protruding annularly is formed in the middle of the oil jet nozzle, and a bracket is provided with a nozzle fitting hole for engaging the annular protrusion to prevent the oil jet nozzle from retaining. It formed, The piston cooling device of the internal combustion engine of Claim 3 characterized by the above-mentioned. 4. An oil jet gallery for guiding lubricating oil discharged from an oil pump to an oil jet nozzle provided for each cylinder through a nozzle through hole, and an oil jet as the discharge pressure of the oil pump rises. The hydraulic valve for opening the gallery, and any one of claims 1 to 3 characterized by the above-mentioned.
And a piston cooling device for an internal combustion engine.