JP2006183654A - Setting method for total ring tension and fuel lubrication type internal combustion engine using light oil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a setting method for the total ring tension of a compression ring and/or an oil ring fitted to the piston of a fuel lubrication type internal combustion engine using light oil for increasing torque or fuel economy. <P>SOLUTION: The total ring tension of the compression ring and/or the oil ring fitted to the piston of the fuel lubrication type internal combustion engine using light oil is set in consideration of an increase in torque and/or fuel economy when the total ring tension is lowered. In this case, the increment of torque due to the lowering of cylinder friction loss resulting from the lowering of the total ring tension is brought into a range surpassing the decrement of torque due to the lowering of a cylinder pressure resulting from the lowering of the total ring tension. Also, the increment of fuel economy due to the lowering of the cylinder friction loss resulting from the lowering of the total ring tension is brought into a range surpassing the decrement of fuel economy due to the adhesion of fuel to a liner resulting from the lowering of the total ring tension. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a compression ring and / or a method for setting a total ring tension of a fuel ring internal combustion engine that uses a fuel such as light oil as a lubricating oil, and a fuel lubricated internal combustion engine such as light oil.

  Conventionally, a first compression ring 2, a second compression ring 3, an oil ring 4 and the like as shown in FIG. 3 are mounted around a piston 1 included in an internal combustion engine mounted on a vehicle. The first compression ring 2, the second compression ring 3, and the oil ring 4 are applied with tension in the radial direction, that is, in the direction of pressing toward the cylinder liner, as indicated by arrows 5, 6, and 7, respectively. Each of these rings is indispensable for an internal combustion engine, for example, by maintaining the in-cylinder pressure by the action of this tension and suppressing the consumption of lubricating oil (oil).

  Recently, a fuel-lubricated internal combustion engine that uses fuel such as light oil as a lubricating oil has been proposed (for example, Patent Document 1). Each ring as described above is also attached to the piston of the engine.

Japanese Utility Model Publication No. 60-194112

  The first compression ring 2, the second compression ring 3, and the oil ring 4 as shown in FIG. 3 are necessary for maintaining the in-cylinder pressure as described above. As the total tension shown in FIG. 1, that is, the total ring tension increases, the sealing performance increases and the in-cylinder pressure is also maintained. A high in-cylinder pressure is advantageous because it generates a high torque. Further, in a conventional internal combustion engine of a type that uses oil for lubrication separately from fuel, the higher the total ring tension of each ring, the lower the oil consumption can be, and also due to blow-by gas. This can advantageously prevent the deterioration of the oil.

  On the other hand, however, if the total ring tension is too high, the friction loss between the piston 1 and the cylinder increases, which can reduce the torque of the internal combustion engine and further reduce the fuel consumption.

  Further, in a fuel-lubricated internal combustion engine using light oil or the like as a lubricating oil as described in Patent Document 1, because of its structure, no lubricating oil is used, and the fuel oil is used in a relatively short time. Since fuel is consumed, there is no need to worry about the deterioration of oil caused by blow-by gas or the consumption of oil.

  Therefore, in view of the above-described circumstances in a fuel lubricated internal combustion engine such as light oil, the present invention provides a compression ring and / or a total ring tension setting method for an oil ring that can achieve improvement in torque and fuel consumption of the internal combustion engine. Another object of the present invention is to provide a fuel lubricated internal combustion engine such as a light oil equipped with a compression ring and / or an oil ring in which the total ring tension is set by the method of setting the total ring tension.

In order to solve such a problem, the total ring tension setting method of the present invention is the sum of compression rings and / or oil rings attached to pistons of a fuel oil-type internal combustion engine such as light oil that also uses fuel such as light oil as a lubricating oil. The ring tension setting method is characterized in that the total ring tension is set in consideration of torque improvement and / or fuel efficiency improvement when the total ring tension is reduced. That is, it is set in consideration of torque improvement and fuel efficiency improvement that are closely related to a decrease in total ring tension. Here, it is desirable to consider both the torque improvement and the fuel efficiency improvement, but only the torque improvement or the fuel efficiency improvement may be considered.
The total ring tension is a total of radial forces acting so that each ring such as a compression ring or an oil ring attached to the piston presses itself against the liner side of the cylinder. In addition, reducing the total ring tension includes not only reducing the total value by reducing the tension of each ring, but also reducing the total value by reducing the number of rings. Therefore, depending on the case, it is conceivable that a single ring is attached to the piston.

  In such a method of setting the total ring tension, the total ring tension is reduced by the torque improvement width due to the reduction in in-cylinder friction loss caused by reducing the total ring tension. It can be set within a range that exceeds the torque drop width associated with the drop in the in-cylinder pressure caused by the. This is a method for setting the total ring tension in consideration of torque improvement. In other words, when the total ring tension is reduced, the torque is improved due to the reduction in in-cylinder friction loss, but the torque is reduced due to the decrease in in-cylinder pressure. The purpose is to reduce the total ring tension within a range where improvement is observed.

  Further, in the method of setting the total ring tension as described above, the fuel efficiency improvement width due to the reduction in in-cylinder friction loss caused by reducing the total ring tension reduces the total ring tension. It can be set in a range that exceeds the range of fuel consumption reduction due to the liner adhering to the fuel resulting from this. This is a setting method in the case of taking fuel efficiency improvement into consideration. In other words, when the total ring tension is reduced, fuel efficiency is improved due to a reduction in in-cylinder friction loss, but fuel equivalent to oil consumption in a general internal combustion engine of a type using lubricating oil in addition to conventional fuel is observed. Although the fuel consumption deteriorates due to the adhesion of the liner, that is, the fuel consumption decreases, the total ring tension is reduced within a range in which the fuel efficiency is still improved even when such an event is taken into consideration.

  Further, in such a method for setting the total ring tension, the total ring tension is reduced by a torque improvement width due to a reduction in in-cylinder friction loss caused by reducing the total ring tension. The total ring tension was reduced from the fuel efficiency improvement range due to the reduction in in-cylinder friction loss due to the reduction in the total ring tension within the range exceeding the torque reduction range due to the reduction in in-cylinder pressure due to It can be set to the point where the value obtained by subtracting the reduction in fuel consumption due to the adhesion of the fuel to the liner is the largest. This is a setting method that places emphasis on improving fuel efficiency within a range where improvements in torque and fuel efficiency are recognized. Therefore, when emphasizing the improvement in torque, the total ring tension is calculated based on the torque improvement width associated with the reduction in in-cylinder friction loss resulting from the reduction in the total ring tension within the range in which the improvement in torque and fuel consumption is recognized. It can also be set to a point where the value obtained by subtracting the torque drop due to the drop in the in-cylinder pressure due to the drop in the value becomes the largest.

  As described above, a piston ring such as a compression ring or an oil ring is necessary for maintaining in-cylinder pressure. Various types of piston rings have been devised. For example, piston rings that can reduce leakage of gas compressed in a cylinder have been proposed. Such a piston ring includes, for example, a synthetic resin ring that is inserted into a ring groove formed on the outer peripheral surface of the piston, and an expander ring that has self-tension and presses the synthetic resin ring from the inside to the outside. There is a piston ring having a configuration in which an elastic ring having a vertical width equal to or larger than a width of the ring groove in the vertical direction of the piston is interposed between the synthetic resin ring and the expander ring. Such a piston ring can prevent blow-by gas from flowing out to the crankcase side. (Hereinafter, such a piston ring is referred to as a “zero blow-by gas ring” in this specification). The total ring tension setting method of the present invention can also be applied to the case where a zero blow-by gas ring is used for a compression ring or an oil ring.

  A fuel-lubricated internal combustion engine of light oil or the like of the present invention is a fuel-lubricated internal combustion engine that uses fuel such as light oil as a lubricating oil, and the total tension is set by the method of setting the total ring tension as described above. A compression ring and / or an oil ring are provided. With such a configuration, it is possible to improve the torque and fuel consumption of a fuel-lubricated internal combustion engine such as light oil.

  Further, another fuel-lubricated internal combustion engine of light oil or the like according to the present invention is a fuel-lubricated internal combustion engine that uses fuel such as light oil as a lubricating oil, and a compression ring and / or an oil ring attached to Piston are provided as pistons. A piston ring comprising a synthetic resin ring inserted into a ring groove formed on an outer peripheral surface, and an expander ring having self-tension and pressing the synthetic resin ring from the inside to the outside, wherein the synthetic resin ring A piston ring having an elastic ring having a vertical width greater than or equal to the width of the ring groove in the vertical direction of the piston is provided between the expander rings. That is, the zero blow-by piston ring is incorporated into a fuel-lubricated internal combustion engine such as light oil.

  Since the zero blow-by gas ring can prevent the blow-by gas from flowing out to the crankcase side, the PCV system for processing the blow-by gas can be omitted. In addition, fuel-lubricated internal combustion engines such as light oil consume fuel in a relatively short period of time as described above, and it is not necessary to use much care for deterioration of oil (fuel) due to blow-by gas. If this is used, it is possible to further reduce the concern of fuel deterioration due to blow-by gas.

  On the other hand, however, when the zero blow-by gas ring is used, the oil (fuel) scraping effect by the blow-by gas, that is, the fuel as the lubricant that has entered the combustion chamber side is less likely to be scraped off to the crank case side. There is a concern that consumption will increase. Too much oil consumption is a problem for vehicle operation and maintenance. For this reason, the adoption of a zero blow-by gas ring in a general internal combustion engine of a type that uses oil for lubrication separately from fuel has been reluctant.

  However, in a fuel-lubricated internal combustion engine that uses fuel such as light oil as a lubricating oil, it is not necessary to worry about oil consumption because of its structure. This is because when fuel such as light oil is a fuel and a lubricating oil, even if the consumption of the fuel as a lubricating oil slightly increases, it is a small amount compared to the consumption of the fuel used for combustion as a fuel. Although there is a slight reduction in fuel consumption, there is no such problem in terms of vehicle operation and maintenance.

  According to the present invention, when the total ring tension of the compression ring and / or the oil ring attached to the piston of the fuel lubricated internal combustion engine such as light oil that also uses fuel such as light oil as the lubricating oil is reduced. Therefore, the torque and fuel efficiency of a fuel-lubricated internal combustion engine such as light oil can be achieved.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a graph illustrating a method for setting the total ring tension of each ring such as a compression ring or an oil ring that is attached to a piston of an internal combustion engine (diesel engine) that uses both light oil and fuel and lubricating oil. Shows the total ring tension, torque fluctuation on the Y axis, and fuel efficiency improvement rate. In the figure, points g and i indicate values of an engine oil lubricated engine using engine oil for conventional lubrication. That is, FIG. 1 shows torque fluctuations and fuel efficiency improvement rates with each value in a conventional engine oil lubricated engine as a reference point (Y = 0).

  First, torque fluctuation will be described. In the figure, point a1 indicates that the friction is reduced due to the fact that the lubricating engine oil is changed to light oil that is also used as fuel, and the torque is improved from the point g by h. That is, since the viscosity of light oil is lower than that of engine oil, friction is reduced and torque is improved accordingly.

  The line segment a indicating the torque improvement due to the friction reduction starting from the point a1 increases as the total ring tension decreases, that is, as it moves to the left in the figure.

  On the other hand, when the total ring tension is lowered, blow-by gas is likely to be generated. When the blow-by gas is increased, the in-cylinder pressure is lowered, and as a result, the torque is lowered as shown by the curve b.

  When the line segment a and the curve b drawn as described above are superimposed, a curve c indicating the total torque change is drawn. A range of the total ring tension in which the curve c drawn in this way exceeds the torque of the conventional engine oil lubricated engine, that is, a torque improvement region is defined as a range A. That is, in the internal combustion engine of the present embodiment, this range A is the cylinder resulting from the reduction in the total ring tension due to the reduction in the in-cylinder friction loss resulting from the reduction in the in-cylinder friction loss. This is a range that exceeds the width of torque reduction accompanying the decrease in internal pressure.

  Next, the fuel efficiency improvement rate will be described. In the figure, the point d1 indicates that the friction is reduced due to the change of the engine oil for lubrication to light oil that also serves as the fuel, and the fuel efficiency is improved by j from the point i. That is, since the viscosity of light oil is lower than that of engine oil, friction is reduced correspondingly and fuel efficiency is improved.

  A line segment d indicating an improvement in fuel consumption due to a decrease in friction starting from the point d1 increases as the total ring tension decreases, that is, as it moves to the left in the figure.

  On the other hand, when the total ring tension is lowered, the light oil changed from the engine oil for lubrication adheres to the cylinder liner and the top land portion of the piston, evaporates and scatters, and is consumed in the exhaust gas. As shown in FIG. In the figure, point e1 indicates that the fuel consumption has decreased by k minutes from point i. This is because the engine oil for lubrication was changed to light oil with higher volatility than engine oil. It is due.

  When the line segment d and the curve e drawn as described above are superimposed, a curve f indicating the total fuel efficiency improvement rate is drawn. Among the curves f drawn in this way, the highest point is the fuel efficiency optimum point B. That is, this fuel efficiency optimum point B is due to the reduction in the total ring tension from the fuel efficiency improvement width accompanying the reduction in the in-cylinder friction loss due to the reduction in the total ring tension in the internal combustion engine of the present embodiment. This is the point where the value obtained by subtracting the fuel consumption reduction width accompanying the fuel liner adhesion is the largest.

  Since the fuel efficiency optimum point B obtained as described above is within the range A obtained from the fluctuation of torque, the value of the total ring tension is set to a value corresponding to the fuel efficiency optimum point B. Actually, measures are taken to reduce the tension of each ring or reduce the number of rings so that the total ring tension becomes this value. If the total ring tension is set by the above process, torque and fuel efficiency can be improved.

  It should be noted that the torque improvement range (range A) and the fuel efficiency optimum point B may be obtained without taking into account the increments h and j due to the combined use of light oil for lubrication as compared with an engine oil lubricated engine.

  Next, a fuel-lubricated internal combustion engine such as light oil according to the present invention will be described. The configuration of the fuel tank, piping, and the like of the fuel-lubricated internal combustion engine such as light oil may be any configuration as long as fuel such as light oil is also used as the lubricating oil. A feature of the fuel-lubricated internal combustion engine of the present invention is that a piston ring such as a compression ring or an oil ring attached to Piston is a zero blow-by gas ring. Hereinafter, the configuration of the zero blow-by gas ring will be described with reference to FIG.

  2A is a sectional view of an embodiment applied to a piston ring of an internal combustion engine. In FIG. 2A, 11 is a piston, and 12 is a ring groove formed in the piston 11. FIG. Reference numeral 13 denotes a synthetic resin ring which is made of, for example, tetrafluoroethylene, has no cut in the circumferential direction, and itself has a very low tension. An elastic ring 14 is made of, for example, heat resistant rubber. Reference numeral 15 denotes an expander ring, which is made of a metal such as steel and has a self-tension and presses the synthetic resin ring 13 toward the outside in the radial direction of the piston 11 via the elastic ring 14. The resin ring 13 is in contact with the cylinder liner 16 via oil (not shown).

  The width D3 of the synthetic resin ring 13 in the vertical direction of the piston is smaller than the width D1 of the ring groove 12 in the vertical direction of the piston in consideration of the mounting property to the ring groove 12, and the upper and lower surfaces of the synthetic resin ring 13 and the ring groove 12 There are gaps C1 and C2 respectively. Since the piston vertical direction width in the free state of the elastic ring 14 is larger than the piston vertical direction width D1 of the ring groove 2, there is a gap between the upper surface and the lower surface of the ring groove 12 when the ring is attached to the ring groove 12. Does not exist. Further, since the elastic ring 14 is pressed against the synthetic resin ring 13 by the expander ring 15, there is no gap between the back surface of the elastic ring 14 and the synthetic resin ring 13.

  Therefore, in this embodiment, blow-by gas passes from the combustion chamber (not shown) through the gap 17 between the piston 11 and the cylinder liner 16 and further into the gap C1 between the synthetic resin ring 13 and the upper surface of the ring groove 12. However, the blow-by gas cannot reach the gap C2 between the synthetic resin ring 13 leading to the crankseose (not shown) and the lower surface of the ring groove 12, so that the blow-by gas does not reach the synthetic resin ring 13 It is prevented that it leaks around the back of the crankcase. Since the space between the synthetic resin ring 13 and the cylinder liner 16 is also sealed, the blow-by gas does not leak from there.

  FIG. 2B is a sectional view showing the structure of another embodiment of the present invention. In this embodiment, the elastic ring has a hollow pipe shape as indicated by 14a, and the expander ring 15 is included in the inside thereof. In addition, since the diameter of the cross section in the free state is larger than the width D1 of the ring groove 12 in the vertical direction of the piston, when the elastic ring 14a is attached to the ring groove 12 as in the embodiment shown in FIG. There is no gap between the upper surface and the lower surface of the ring groove 12. In this embodiment, the blow-by gas passes from the combustion chamber through the gap 17 between the piston 11 and the cylinder liner 16, and further through the gap C1 between the synthetic resin ring 13 and the upper surface of the ring groove 12, and the synthetic resin ring. 13 reaches the upper space 8 between the back surface of the elastic ring 14 and the elastic ring 14a. However, as described above, there is no gap between the elastic ring 14a and the synthetic resin ring 13, so that the space 8 moves downward in the figure. It cannot escape to the lower space 9 between the back surface of the synthetic resin ring 13 and the elastic ring 14a. In addition, since there is no gap between the elastic ring 14a and the upper surface of the ring groove 12, the space 8 does not pass through the back surface of the elastic ring 4a to the space 9. Therefore, the blow-by gas is prevented from leaking into the crankcase.

  As described above, even in the embodiment shown in FIG. 2B, the blow-by gas is prevented from leaking around the back surface of the synthetic resin ring 13 and leaking into the crankcase. Moreover, since the elastic ring 14a and the expander ring 15 are integrated, the mounting to the piston 11 is easy.

  FIG. 2C is a cross-sectional view showing the structure of still another embodiment of the present invention. In this embodiment, the expander ring 15 is embedded in an elastic ring indicated by 14b. Since the operation and effects of this embodiment are the same as those of the embodiment shown in FIG.

  According to each of the above embodiments, since the space is formed between the expander ring 15 or the elastic rings 14 a and 14 b and the bottom wall h of the ring groove 12, the piston ring moves in the radial direction with respect to the piston 11. Becomes easy. Therefore, the piston ring is free to move with respect to the radial movement of the piston 11 relative to the cylinder liner 16. Further, since there is an elastic ring between the synthetic resin ring 13 and the expander ring 15, the piston 11 swings and a force is applied to instantaneously crush the synthetic resin ring 13 in the piston radial direction. When this occurs, the force is absorbed by the elastic ring, and the durability of the synthetic resin ring 13 is improved. Furthermore, the sliding surface of the synthetic resin ring 13 with the cylinder liner 16 is worn out by long-term use, and the expander ring 15 is stretched and the tension is lowered. At the same time, if the elastic ring is rubber, the elastic ring is made by lubricating oil. Since this swells and increases the thickness, it is possible to compensate for the decrease in the tension and to prevent the decrease in the tension of the entire piston ring.

  As described above, when setting the total tension of the piston ring as described above, the method described in the first embodiment can be used. By using the piston ring of the present embodiment, fuel deterioration due to blow-by gas can be reduced, and if the total ring tension is set by the above-described process, it is possible to improve torque and improve fuel efficiency.

  The above-described embodiments are merely examples for carrying out the present invention, and the present invention is not limited to them. Various modifications of these embodiments are within the scope of the present invention. It is apparent from the above description that various other embodiments are possible within the scope.

It is a graph explaining the setting method of the total ring tension | tensile_strength of each ring in the Example of this invention. (A)-(c) is sectional drawing which shows each different structure using a zero blow-by gas ring. It is a figure explaining each ring with which a piston is mounted | worn, and the action direction of each tension | tensile_strength.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piston 2 1st compression ring 3 2nd compression ring 4 Oil ring 11 Piston 12 Ring groove 13 Synthetic resin rings 14, 14a, 14b Elastic ring 15 Expander ring 16 Cylinder liner

Claims (7)

A method of setting a total ring tension of a compression ring and / or an oil ring attached to a piston of a fuel lubricated internal combustion engine such as a light oil that also uses a fuel such as light oil as a lubricating oil,
The total ring tension is set in consideration of torque improvement and / or fuel consumption improvement when the total ring tension is lowered. In the setting method of the total ring tension | tensile_strength of Claim 1,
The total ring tension is reduced by an increase in torque due to a decrease in in-cylinder friction loss due to a decrease in the total ring tension, and a decrease in torque due to a decrease in an in-cylinder pressure due to a decrease in the total ring tension. A method for setting the total ring tension, characterized in that the total ring tension is set within a range exceeding. The method for setting the total ring tension according to claim 1 or 2,
The total ring tension is reduced in fuel efficiency due to the reduction of the total ring tension, and the fuel efficiency improvement accompanying reduction in in-cylinder friction loss due to the reduction in total ring tension is caused by the reduction in the total ring tension. A method for setting the total ring tension, characterized in that the range exceeds the width. In the setting method of the total ring tension according to any one of claims 1 to 3,
The total ring tension is reduced by an increase in torque due to a decrease in in-cylinder friction loss due to a decrease in the total ring tension, and a decrease in torque due to a decrease in an in-cylinder pressure due to a decrease in the total ring tension. In the range exceeding the above, the reduction in fuel consumption accompanying the liner adhesion of the fuel resulting from the reduction in the total ring tension from the improvement in fuel consumption resulting from the reduction in the in-cylinder friction loss resulting from the reduction in the total ring tension. A method for setting the total ring tension, characterized in that the value obtained by subtracting is the largest point. In the setting method of the total ring tension according to any one of claims 1 to 4,
The compression ring and / or the oil ring is composed of a synthetic resin ring inserted into a ring groove formed on the outer peripheral surface of the piston, and an expander ring having self-tension and pressing the synthetic resin ring from the inside to the outside. A piston ring,
A total ring tension setting method characterized in that an elastic ring having a vertical width greater than or equal to the vertical width of the piston in the ring groove is interposed between the synthetic resin ring and the expander ring. . A fuel-lubricated internal combustion engine that uses fuel such as light oil as a lubricating oil,
A fuel-lubricated internal combustion engine such as diesel oil, comprising a compression ring and / or an oil ring in which the total tension is set by the total ring tension setting method according to any one of claims 1 to 5. In a fuel-lubricated internal combustion engine such as light oil that uses fuel such as light oil as a lubricating oil,
Compression ring and / or oil ring attached to Pistonton
A piston ring comprising a synthetic resin ring inserted into a ring groove formed on the outer peripheral surface of the piston, and an expander ring having self-tension and pressing the synthetic resin ring from the inside to the outside,
A fuel-lubricated internal combustion engine such as light oil, characterized in that an elastic ring having an upper and lower width equal to or greater than the width of the piston in the vertical direction of the ring groove is interposed between the synthetic resin ring and the expander ring organ.

Images