JPH0650119A - Lubricating device for internal combustion engine - Google Patents

Abstract

PURPOSE:To feed a sufficient quantity of lubricating oil to concerned portions as required in order to maintain excellent lubricating ability of a crank journal and a crankpin of a crankshaft even in an operating state of large heat generation such as high load operation of an engine. CONSTITUTION:An oil gallery 7 for feeding lubricating oil from an oil pump to a main bearing 2 and a crankpin 6 of a crankshaft 1 is formed inside of the crankshaft 1. A return passage 12 for communicating the oil gallery 7 with an oil pan 11 is formed and a control valve 15 for controlling a circulating oil quantity in the oil gallery 7 is installed in the return passage 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating device for an internal combustion engine.

[0002]

2. Description of the Related Art As a device for lubricating each portion of an internal combustion engine, generally known is a device configured as shown in FIGS.

Lubricating oil is stored in an oil pan 31 below the cylinder block 30, and from there, the oil strainer 3
It is sucked up by the oil pump 33 through 2. Lubricating oil from the oil pump 33 enters the main gallery 35 of the cylinder block 30 from the oil filter 34, part of which is supplied to the main bearing 38 of the crankshaft 36, and part of which is supplied to lubricate the camshaft 37 and the valve mechanism. Is
Each returns to the oil pan 31.

A part of the lubricating oil of the main bearing 38 passes through a hole 39 in the crankshaft 36 and is sent from a crank journal 40 to a crankpin 41 to lubricate a bearing 44 of a connecting rod 43 and a part of the lubricating oil.
3 is sprayed from the spray hole 42, lubricates the cylinder and piston, and returns to the oil pan 31.

In this case, if the lubricating oil to be sent to each part of the engine is not provided with an appropriate pressure, it will not enter the small gaps of each part or it will be difficult to circulate in the lubricating oil system passage. On the other hand, when the temperature of the lubricating oil is low, the hydraulic pressure is greatly increased and the pump drive load is increased. Further, even if the temperature of the lubricating oil is normal, the oil feeding capacity of the pump 33 has a capacity two to three times as much as the oil amount required by the engine. It will also happen. Therefore, regardless of the operating state of the engine, the oil pressure regulator 46 is provided as shown in FIG. 8 in order to keep the discharge pressure of the pump 33 appropriate.

The regulator 46 closes the bypass passage of the pump 33 when the oil pressure is low, and opens the bypass passage when the oil pressure rises above a set pressure to return a part of the oil discharged from the pump 33 to the pump suction side. ing. In addition,
The oil pump 33 shown in FIG. 8 is an internal gear type in which the outer gear 47 and the inner gear 48 rotate while inscribed, and 49 indicates a crescent (partition plate) for preventing oil from leaking from high pressure to low pressure. FIG. 9 is a characteristic diagram illustrating the relationship between the discharge amount of the oil pump 33, the circulation amount of the engine, and the hydraulic pressure.

[0007]

By the way, the lubricating oil supplied to each part of the engine receives, in addition to the heat transferred from the combustion chamber through the wall of the cylinder block 30 and the like, the frictional heat generated by the sliding of each part. For example, it will perform a cooling function to remove these heat and release it to the outside,
If the operating conditions of high speed and high load are still maintained, for example, the crank pin 41 of the crank shaft 36 and the crank journal 40 may reach a high temperature of 150 ° C. or higher, so that the viscosity of the lubricating oil is extremely lowered,
The metal contact causes problems such as increased wear and reduced output.

Therefore, it is conceivable to increase the supply amount (circulation amount) of the lubricating oil in order to lower the temperature of each part of the engine lubricating system. Since the supply amount of lubricating oil is basically determined by the outflow condition from each oil clearance (about 50 μm), if the supply amount is increased, the oil clearance should be increased or the discharge pressure (oil pressure) of the oil pump 33 should be increased. It is necessary to adjust the set pressure of the regulator 46) to a higher level. However, there is a problem that when the oil clearance is increased, the metal tapping sound is deteriorated, and when the discharge pressure of the oil pump is increased more than necessary, the driving loss of the pump 33 is increased and the output fuel consumption is lowered.

The present invention has been made in view of these problems, and in order to maintain good lubricity of the crank journal of the crankshaft and the crankpin,
It is an object of the present invention to provide an apparatus capable of supplying a sufficient amount of lubricating oil to cool these parts as needed.

[0010]

Therefore, according to the invention of claim 1, an oil gallery for supplying the lubricating oil from the oil pump to the main bearing and the crank pin bearing of the crankshaft is formed inside the crankshaft, and the oil gallery is formed. To form a return passage communicating with the oil pan,
A control valve is installed in the return passage to control the amount of circulating oil in the oil gallery.

According to the second aspect of the present invention, the control valve is opened when a large amount of heat is generated, such as a high load, based on the operating condition of the engine. According to the third aspect of the invention, a release valve that operates at a lower set pressure than the oil pressure regulator of the oil pump is provided in the return passage in series with the control valve.

In a fourth aspect of the present invention, the crankshaft is made up of a material which is formed in half including an oil gallery on a plane that passes through the shaft core, and an amorphous alloy sheet is sandwiched between the joining surfaces of the two, and these are heated. Then, it is made by processing the surface of the crank journal and crank pin after integration.

[0013]

According to the first aspect of the invention, the lubricating oil sent from the oil pump to the crankshaft side is supplied to the main bearing and the crankpin bearing through the oil gallery inside the shaft, and when the control valve opens, most of it is supplied. Since it is returned to the oil pan via the return passage, the oil pressure regulator of the oil pump closes regardless of the engine speed, so the amount of lubricating oil circulating in the oil gallery inside the crankshaft increases by the amount of the regulator flow rate. To do.

Therefore, if the control valve is opened when the amount of heat generated is large, such as when the engine is under high load, the crankpin and the crank journal, etc. are caused by a large amount of lubricating oil flowing through the oil gallery in the crankshaft. Since the amount of heat is taken out to the outside, the temperatures of the main bearing and the crankpin bearing, etc., drop moderately. As a result, it is possible to prevent an increase in wear and a decrease in output due to an extreme decrease in the viscosity of the lubricating oil.

According to the third aspect of the invention, since the relief valve is provided in the return passage, the required hydraulic pressure can be secured even when the control valve is open. Further, according to the invention of claim 4, the crankshaft can be easily and easily formed by joining the halved raw materials with the amorphous alloy sheet.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, 1 is a crankshaft, 2 is a main bearing for supporting a crank journal 3 thereof, each bearing 2 is a bulkhead 4 for partitioning between cylinders, and a bearing cap 5 is fastened to each of these with a bolt. Composed of and. Further, each crankpin 6 is connected to a piston via a connecting rod (not shown), and is rotated about the main bearing 2 as the piston reciprocates.

An oil gallery 7 continuous from one end to the other is formed inside the crankshaft 1, and oil holes 8 and 9 for opening the oil gallery 7 are provided on the outer circumference of each crank journal 3 and each crankpin 6. To be The main bearing 2 at one end has a supply passage 10 that opens an oil passage from a main gallery (not shown) of the cylinder block to the bearing surface.
However, a return passage 12 connected to the oil pan 11 is formed in the main bearing 2 at the other end, and the oil hole 8 of each crank journal 3 is formed.
An annular groove 13 is provided which always communicates with these passages 10, 12.

A part of the lubricating oil from the main gallery is supplied to the main bearing 2 through the supply passage 10, and the other part is supplied to lubricate the camshaft and the valve mechanism as in the conventional case. Lubricating oil from the annular groove 13 to the oil hole 8
Is supplied to the main bearing and the crank pin through an oil gallery, and when a control valve 15 to be described later opens, most of the oil flows from the oil hole 8 through the annular groove 13 to the oil through the return passage 12. It is supposed to return to bread.

A control valve 15 for controlling the flow rate of the lubricating oil to the oil pan 11 is provided in the middle of the return passage 12,
Relief valve 16 that operates at a lower set pressure than the oil pressure regulator of the oil pump (see FIG. 8)
Are inserted in series. The control unit 1 controls the control valve 15 according to the operating state of the engine.
If the high temperature state of the crankpin 6 or the like is determined from the rotational speed of the engine, the load state, and the cooling water temperature, the shaft 1
Control valve 1 to increase the amount of circulating oil inside
Control to open 5.

FIG. 2 shows the structure of the relief valve 16. The valve 16a has a spring 16 when the hydraulic pressure is low.
It is pushed by b to close the return passage 12, and the hydraulic pressure is applied to the spring 1.
When the load exceeds the set load of 6b, the spring 16b is bent to open the return passage 12.

The crankshaft 1 is shown in FIG.
As described above, the half-divided materials 1A and 1B (which are separately formed by casting, including the hollow portion of the oil gallery 7 on a plane that passes through the axis of the shaft 1) are finished with an amorphous alloy sheet after finishing the joining surfaces. 1C is sandwiched and assembled, and in that state, it is kept at a high temperature condition of about 1200 ° C (put in a furnace etc.) for a certain period of time, and after these joints are integrated, surface processing of the crank journal 3 and the crankpin 6 etc. is performed. To be done.

With this structure, the lubricating oil in the oil pan 11 is sucked up by the oil gallery into the main gallery and supplied to the crankshaft 1 side and the camshaft side as before, so that the engine speed is increased. When the pressure rises above a predetermined value (for example, 2000 rpm), the oil pressure regulator causes an excessive amount of oil to escape to the pump suction side (see FIG. 9).

Lubricating oil to the crankshaft 1 side is supplied to the main bearing 2 via the supply passage 10, and further to the crankshaft 1
It is supplied to the other main bearing 2 and the crank pin 6 through the internal oil gallery 7 and lubricates them, and at the same time, a part of them is jetted from the spray hole of the connecting rod to lubricate the cylinder and piston and to make the oil out of the oil clearance. It is returned to the oil pan 11 together.

When the normal state is shifted to a predetermined operating state such as a high speed and high load region of the engine, the control unit 1
7 opens the control valve 15, and the lubricating oil inside the crankshaft 1 is supplied to the crank journals 3 and the crank pins 6 at the set pressure of the relief valve 16 as described above, while most of the lubricating oil is supplied. Is returned to the oil pan 11 via the return passage 12. Therefore, the pressure in the system decreases and the oil pressure regulator closes, so that the amount of lubricating oil circulating in the oil gallery 7 inside the crankshaft 1 increases by the amount of the regulator flow rate.

Therefore, the amount of heat of the crank pin 6 and the crank journal 3 is efficiently carried out to the outside by the large amount of lubricating oil flowing in the shaft 1.
It is possible to keep the crankpin temperature low as shown in. That is, it is possible to prevent an increase in wear and a decrease in output due to the extreme decrease in the viscosity of the lubricating oil.

During warm-up and immediately after that, the control valve 15 is closed (the amount of circulating oil to the engine is regulated by the oil pressure regulator) in the medium-speed low-load region, and the oil inside the crankshaft 1 is closed. Gallery 7
Since the amount of circulation to the lubricating oil is reduced, the temperature rise of the lubricating oil, that is, the appropriate decrease in viscosity is promoted, and the friction loss in the lubricated portion is reduced.

[0027]

In summary, according to the present invention, the oil gallery for supplying the lubricating oil from the oil pump to the crankshaft main bearing and the crankpin bearing is formed inside the crankshaft, and this oil gallery is used in the oil pan. Since a return passage that communicates is formed and a control valve that controls the amount of circulating oil in the oil gallery is provided in the return passage, the main bearing of the crankshaft and the crankpin bearing are cooled by opening the control as necessary. Can supply a sufficient amount of lubricating oil.

In this case, if the control valve is opened when a large amount of heat is generated, such as a high load, based on the operating state of the engine, an increase in wear and a decrease in output due to an extreme decrease in lubricating oil viscosity are prevented. The effect of being able to be obtained is obtained.

By providing a relief valve in the return passage, the required hydraulic pressure can be secured even when the control valve is open. Also, the crankshaft can be easily and easily manufactured by joining the halved materials with an amorphous alloy sheet.

[Brief description of drawings]

FIG. 1 is an overall schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration diagram of a relief valve of the same.

FIG. 3 is likewise a composition explanatory view of a crankshaft.

FIG. 4 is a characteristic diagram showing the relationship between the operation of the control valve and the temperature of the crankpin.

FIG. 5 is a schematic configuration diagram of an entire engine for explaining a conventional technique.

FIG. 6 is a partial sectional view of the same.

FIG. 7 is an explanatory view showing a lubricating oil supply structure to the crankshaft side.

FIG. 8 is a sectional view of the oil pump of the same.

FIG. 9 is a characteristic diagram similarly showing a relationship between a pump discharge amount, an engine circulation amount, and an oil pressure.

[Explanation of symbols]

 1 crankshaft 2 main bearing 3 crank journal 6 crank pin 7 oil gallery 8, 9 oil hole 10 supply passage 11 oil pan 12 return passage 13 annular groove 15 control valve 16 relief valve 17 control unit

Claims (4)

[Claims] 1. An oil gallery for supplying lubricating oil from an oil pump to a crankshaft main bearing and a crankpin bearing is formed inside the crankshaft, and a return passage communicating the oil gallery with an oil pan is formed. A lubricating device for an internal combustion engine, wherein a control valve for controlling the amount of circulating oil in an oil gallery is provided in the return passage. 2. The lubricating apparatus for an internal combustion engine according to claim 1, wherein the control valve is opened when a large amount of heat is generated, such as a high load, based on the operating state of the engine. 3. The lubricating device for an internal combustion engine according to claim 1, wherein a relief valve that operates at a set pressure lower than an oil pressure regulator of the oil pump is provided in the return passage in series with the control valve. 4. The crankshaft is made of a material that is formed in half including an oil gallery on a plane that passes through the axis, and an amorphous alloy sheet is sandwiched between the joining surfaces of the two materials. The lubricating device for an internal combustion engine according to claim 1, wherein the lubricating device is formed by subjecting a crank pin or a crank pin to surface treatment.