JPH06123357A - Piston device - Google Patents

Abstract

PURPOSE:To realize the prevention of seizure between a piston ring and a cylinder liner and reduction in consumption of lubricating oil by regulating the tension of an oil ring in a piston device for engine according to engine load. CONSTITUTION:Top ends of a pair of levers 6 are engaged with an expander ring 4 in the oil ring 3 of a piston 1, and a taper cone 7 connected to an actuator 8 is fitted between the other ends of the levers 6. At high load of engine, the taper cone 7 is pressed down by the pressure oil supplied to an oil chamber 11 to approach the top ends of the levers 6 to each other, whereby the tension of the expander spring 4 is reduced, and at low load of engine, the supply of the pressure oil is interrupted, and the tension of the expander spring 4 is conversely increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piston device such as an engine, and more particularly to a piston device having an oil ring.

[0002]

2. Description of the Related Art Fine particles contained in the exhaust gas of an engine, especially a diesel engine, are one of the pollution sources that pollute the environment. Some of these fine particles are the lubricating oil used in the engine and discharged with the exhaust gas. Therefore, if the consumption amount of the lubricating oil is reduced, the discharge amount of the fine particles will be considerably reduced. On the other hand, the lubricating oil adhering to the inner surface of the cylinder liner of the engine is scraped off by an oil ring installed in the oil ring groove of the piston with appropriate strength according to the up and down movement of the piston, and a lubricating oil film is formed on the inner surface of the cylinder liner. As the lubricating oil rises while being formed, it is regulated. As shown in an example in FIG. 4, the lubricating oil consumption amount and the tension of the oil ring are in an inversely proportional relationship. When the engine load is small, the seizure limit between the piston ring and the cylinder liner is line A, whereas when the engine load is large, the seizure limit moves to line B.

Therefore, conventionally, in order to reliably prevent the seizure of the piston ring and the cylinder liner, the oil ring inner peripheral surface is adjusted so that the magnitude of the tension of the oil ring becomes the point X located on the left side of the line B. Since the spring force of the expander spring installed along the line was adjusted and the oil ring tension could not be raised further, the consumption of lubricating oil had to be large even when the engine load was low. Therefore, it is difficult to reduce the consumption of lubricating oil.

[0004]

SUMMARY OF THE INVENTION The present invention realizes prevention of seizure between the piston ring and the cylinder liner and reduction of lubricating oil consumption by adjusting the tension of the oil ring in the piston device according to the load. Is what you are trying to do.

[0005]

Therefore, in the piston device according to the present invention, the piston ring is installed in the oil ring groove, and the expander spring is mounted along the inner peripheral surface of the piston ring. It has a mechanism to increase the tension of the expander spring.

[0006]

Therefore, since the tension of the expander spring is relatively weak while the load of the engine or the like is large, the amount of lubricating oil scraped off by the oil ring is small, and seizure between the piston ring and the cylinder liner is reliably prevented. At the same time, since the tension of the expander spring is increased when the load on the engine or the like is decreased, the scraping amount of the lubricating oil by the oil ring is increased, and the consumption amount of the lubricating oil can be easily reduced.

[0007]

EXAMPLES Examples of the present invention will be specifically described below. 1 and 2, an oil ring 3 having a substantially H-shaped cross section is installed in an oil ring groove 2 of a piston 1 for a diesel engine, and an expander spring 4 is mounted along an inner peripheral surface of the oil ring 3. Has been done.
On the other hand, the tips of the pair of levers 6 pivotally supported by the piston 1 by the shaft 5 are inserted between both ends of the expander spring 4, and the taper cone 7 is fitted between the other ends of the levers 6, and the upper part of the taper cone 7 is The actuator 8 is connected to the actuator 8 and is urged upward by a return spring 9. At the same time, a hydraulic source (not shown) sequentially passes through a solenoid valve or a pressure regulating valve, a main bearing, a crankshaft and a connecting rod, and an oil passage of the piston 1. The pressure oil supplied to the oil chamber 11 by 10 acts downward on the actuator 8.

The solenoid valve or pressure regulating valve opens when the load on the engine increases and supplies a hydraulic pressure to the oil chamber 11 which increases stepwise or steplessly in response to an increase in the engine load, or the engine load is increased. When the pressure is increased to a predetermined value or more, pressure oil is supplied to the oil chamber 11 to push down the actuator 8 and the taper cone 7, the displacement amount is amplified, and the tip of the lever 6 that sandwiches the taper cone 7 approaches, and the expander spring 4 It is designed not to expand both ends of.
Therefore, the tension of the expander spring 4, and thus
The tension of the oil ring 3 is relatively weak, and it is located on the left side of the seizure limit line B at the time of high load as shown by point X in FIG. Seizure between the cylinder liner and the cylinder liner is reliably prevented.

On the other hand, when the engine load decreases, the solenoid valve or pressure regulating valve operates so as to cut off the supply of pressure oil to the oil chamber 11 or to supply a low oil pressure, so that the actuator 8 and the taper cone 7 are spring-loaded. 9, the displacement amount is amplified, the tip of the lever 6 that sandwiches the taper cone 7 is opened, and both ends of the expander spring 4 are expanded, and as a result, the tension of the expander spring 4, and thus the tension of the oil ring 3, is increased. Strengthened, seizure limit line A at low load as shown by point Y in FIG.
Located immediately to the left of, the amount of lubricating oil scraped off by the oil ring 3 increases, and the amount of lubricating oil consumed can be easily reduced.

That is, by adjusting the tension of the oil ring 3 according to the level of the engine load, seizure between the piston ring and the cylinder liner can be prevented, and the consumption of lubricating oil can be suppressed to a low level to reduce the operating cost of the engine. It is possible to reduce the amount of particulate matter in the engine exhaust gas and to help prevent pollution.

Next, the embodiment shown in FIG. 3 will be described by giving the same reference numerals to the same parts as those of the above embodiment. Similar to the above embodiment, the tip ends of the pair of levers 6 are inserted between both ends of the expander spring 4 mounted along the inner peripheral surface of the oil ring 3, and the tapered cone 7 fitted between the other ends of the levers 6. Is connected to the actuator 8 and the working medium such as silicon oil, heat resistant wax, or bimetal contained in the space 20 of the piston 1 or a memory alloy member that expands and contracts according to the temperature rise and fall. Two
1 is in contact with the actuator 8.

Therefore, when the load of the engine is large and the piston 1 is at a high temperature, the working medium 21 also becomes a high temperature and expands or expands downward, the actuator 8 and the taper cone 7 are pushed down, and the lever 6 sandwiching the taper cone 7 is sandwiched. Of the expander spring 4 is prevented from expanding the both ends of the expander spring 4, and the tension of the expander spring 4, and hence the tension of the oil ring 3, is relatively weak. Located to the left of line B,
Since the amount of lubricating oil scraped off by the oil ring 3 is reduced, seizure between the piston ring and the cylinder liner is reliably prevented.

When the load of the engine decreases and the temperature of the piston 1 decreases, the temperature of the working medium 21 also decreases and contracts upward, and the actuator 8 and the taper cone 7 move to the spring 9
Is pushed up, the displacement amount is amplified, and the tip of the lever 6 that sandwiches the taper cone 7 is opened, so that both ends of the expander spring 4 are pushed apart. As a result, the tension of the expander spring 4, and thus the tension of the oil ring 3. Is located immediately to the left of the seizure limit line A when the load is low, as shown by the point Y in FIG. 4, the amount of lubricating oil scraped off by the oil ring 3 increases, and the amount of lubricating oil consumed is facilitated. Since it can be reduced, the same effect as that of the above embodiment can be obtained.

[0014]

The piston device according to the present invention ensures the seizure between the piston ring and the cylinder liner at high load by changing the tension of the expander spring in the oil ring according to the load level of the engine or the like. In addition to the prevention, it is possible to easily reduce the consumption amount of the lubricating oil when the load is low, and it is possible to reduce the operating cost of the engine and the like and prevent pollution by reducing the amount of fine particles in the engine exhaust gas.

[Brief description of drawings]

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

FIG. 2 is an enlarged view taken along the line II-II in FIG.

FIG. 3 is a vertical cross-sectional view of another embodiment of the present invention.

FIG. 4 is an explanatory view of the operation of the above embodiment.

[Explanation of symbols]

 1 Piston 3 Oil Ring 4 Expander Spring 6 Lever 7 Tapered Cone 8 Actuator 11 Oil Chamber 21 Working Medium

Claims (2)

[Claims] 1. A piston device provided with an oil ring installed in an oil ring groove and provided with an expander spring along the inner peripheral surface thereof, and a mechanism for increasing the tension of the expander spring in response to a decrease in load. 2. An oil ring installed in an oil ring groove and having an expander spring mounted along the inner peripheral surface thereof, a medium which operates according to the magnitude of a load, and an operation amount of the medium are transmitted to the expander spring. And a piston device configured to increase the tension of the expander spring when the load decreases.