JP5928265B2 - Wear resistant ring, piston and internal combustion engine - Google Patents

Description

  The present invention relates to a wear-resistant ring, a piston, and an internal combustion engine having the piston.

  For example, as described in Patent Document 1, a ring groove in which a piston ring is mounted is formed on a piston for an internal combustion engine by a wear-resistant ring made of a material that is superior in wear resistance to a material forming a piston body. There is something to do.

Japanese Utility Model Publication No. 7-38645

  By the way, the loads received by the piston and the wear-resistant ring due to combustion of the internal combustion engine or the like are not uniform over the entire circumference, and are different for each part. And in the site | part with a comparatively large load, deformation | transformation of a wear-resistant ring and the deformation | transformation and damage of a ring groove resulting from it become easy to produce. If such deformation occurs, the combustion pressure cannot be increased sufficiently and the engine output may be reduced. Therefore, in order to suppress this, when the thickness of the wear-resistant ring is increased so that deformation of the wear-resistant ring does not occur even in a portion where the load is relatively large, the weight of the wear-resistant ring becomes heavy, Since the weight of the whole piston provided with this also becomes heavy, the fuel consumption of the internal combustion engine will be deteriorated.

  The present invention has been made in view of such circumstances, and the object thereof is to prevent the wear-resistant ring from being deformed while suppressing the weight of the piston from being increased, and the piston provided with the wear-resistant ring. An object of the present invention is to provide an internal combustion engine having the piston.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
A wear-resistant ring that solves the above problem is a wear-resistant ring having a pair of opposed walls that are opposed to each other with a ring groove formed on an outer peripheral surface, and a side wall that connects these opposed walls on the inner circumferential side. The gist of at least one of the opposing walls is that the thickness includes a relatively thick part and a relatively thin part in the circumferential direction.
Moreover, it is preferable that such a wear ring is provided over the entire circumference of the ring groove and the pair of opposing walls.

It is preferable to provide such a wear-resistant ring on the piston.
According to each said structure, at least one of a pair of opposing wall of a wear-resistant ring is not uniform in the circumferential direction, and is provided with the thick part and the thin part. Therefore, it is possible to arrange the thick portion at a portion where the load received by the piston is relatively large, and the strength of the wear-resistant ring can be relatively increased at the portion where the load received by the piston is relatively large. . Thereby, deformation | transformation etc. of a wear-resistant ring can be suppressed also in the site | part which the load which a piston receives is comparatively large. On the other hand, since the opposing wall of the wear-resistant ring has a thin part with a relatively small thickness, the wear-resistant ring can be made lighter than when it is formed to the same thickness as the thick part over the entire circumference. Can be planned. Therefore, according to the said structure, a deformation | transformation etc. of a wear resistant ring can be suppressed, suppressing that the weight of a wear resistant ring and a piston becomes heavy.

  Further, an internal combustion engine having a supercharger has a piston provided with the wear ring, the thick part of the wear ring is arranged on the intake valve side, and the thin part is arranged on the exhaust valve side. Is preferred.

  In an internal combustion engine equipped with a supercharger, the inventor of the present application has confirmed through experiments that the load (in-cylinder pressure) acting on the piston is greater on the intake valve side than on the exhaust valve side when pre-ignition occurs. Therefore, in the above configuration, the thick portion of the wear-resistant ring is arranged on the intake valve side where the load acting on the piston becomes large when pre-ignition occurs, while the exhaust valve side on which the load acting on the piston is relatively small The thin part is arranged in Thereby, in a piston of an internal combustion engine equipped with a supercharger, deformation of the wear-resistant ring can be suppressed even in a portion where the load received by the piston due to the occurrence of pre-ignition becomes relatively large, and the exhaust valve in the wear-resistant ring By making the site | part located in the side into a thin part, it can suppress that the weight of a piston becomes heavy.

The schematic diagram which shows the internal combustion engine which concerns on one Embodiment of this invention. The perspective view which shows a part of piston in the embodiment in a cross section. The front view of the wear-resistant ring in the same embodiment. FIG. 4 is a sectional view taken along line 4-4 of FIG. Sectional drawing of the wear-resistant ring which concerns on other embodiment of this invention. Sectional drawing of the wear-resistant ring which concerns on other embodiment of this invention.

Hereinafter, an embodiment embodying a wear-resistant ring, a piston, and an internal combustion engine according to the present invention will be described. The internal combustion engine of this embodiment is a gasoline engine.
As shown in FIG. 1, a throttle valve 12 is provided in the intake passage 11 of the internal combustion engine 10. In the internal combustion engine 10, the amount of air taken into the combustion chamber 15 is adjusted by adjusting the opening degree of the throttle valve 12. A fuel injection valve 13 is provided in the intake passage 11. The fuel injection valve 13 injects fuel toward the intake port as the valve is opened.

A piston 30 is provided in the cylinder 14 of the internal combustion engine 10. A piston ring 30 </ b> A is attached to the piston 30.
As shown in FIG. 2, the piston 30 is formed with three ring grooves 34 into which the piston ring 30A is mounted. In the piston 30, a wear-resistant ring 32 is fixed to the piston body 31. The wear-resistant ring 32 is provided at a portion corresponding to the uppermost ring groove 34 closest to the combustion chamber 15 among the three ring grooves 34 of the piston 30, and the piston ring 30 </ b> A is provided on the outer circumferential surface 33 of the wear-resistant ring 32. A ring groove 34A to be mounted is formed. The wear-resistant ring 32 is formed of a material that is more excellent in wear resistance than the piston body 31. For example, the wear-resistant ring 32 is made of cast iron and the piston body 31 is made of aluminum. The wear-resistant ring 32 is fixed to the piston body 31 by casting the wear-resistant ring 32 with a molten aluminum.

  As shown in FIG. 1, the internal combustion engine 10 is provided with a spark plug 17 so as to face the combustion chamber 15. In the internal combustion engine 10, the fuel injected from the fuel injection valve 13 burns in the combustion chamber 15, whereby the piston 30 reciprocates and the crankshaft 18 rotates. The gas after combustion is sent out from the combustion chamber 15 to the exhaust passage 19 as exhaust.

  The intake passage 11 and the combustion chamber 15 are communicated and blocked by opening and closing the intake valve 21, and the exhaust passage 19 and the combustion chamber 15 are communicated and blocked by opening and closing the exhaust valve 22. Two intake valves 21 and two exhaust valves 22 are provided for each cylinder 14.

  The internal combustion engine 10 is provided with a supercharger 40 that pumps intake air in the intake passage 11. Specifically, the compressor 41 of the supercharger 40 is attached to the upstream side of the throttle valve 12 in the intake passage 11. A turbine 42 of the supercharger 40 is attached to the exhaust passage 19 of the internal combustion engine 10. The supercharger 40 is of an exhaust drive type in which a compressor wheel 41A provided in the compressor 41 and a turbine wheel 42A provided in the turbine 42 are connected. In the exhaust passage 19, the upstream side and the downstream side of the turbine 42 are connected by a bypass passage 43, and a waste gate valve 44 is provided in the bypass passage 43. By adjusting the opening degree of the waste gate valve 44, the flow rate of the exhaust gas blown to the turbine wheel 42A is changed, and the pumping amount of the intake air is adjusted.

  By the way, in a gasoline engine, preignition in which the air-fuel mixture burns may occur prior to ignition by the spark plug. The inventor of the present application, in a gasoline engine equipped with a supercharger, at the time of occurrence of pre-ignition, the combustion pressure due to pre-ignition is larger on the intake valve side than on the exhaust valve side. It is confirmed that the load acting on the piston is larger on the side. Further, the inventors of the present application have confirmed by experiments that in a gasoline engine having a supercharger, the combustion pressure at the time of occurrence of pre-ignition becomes larger than the combustion pressure due to normal combustion due to ignition of the ignition plug.

  Therefore, in such a gasoline engine, the stress of the piston ring acting on the wear-resistant ring is increased on the intake valve side where the load acting on the piston is relatively large when pre-ignition occurs. As a result, deformation of the wear-resistant ring and deformation or damage of the ring groove due to the deformation are likely to occur. When such deformation occurs, the combustion pressure cannot be sufficiently increased, and the output of the internal combustion engine may be reduced.

  Therefore, in the internal combustion engine 10 according to the present embodiment, the wear-resistant ring 32 provided on the piston 30 has a shape in which deformation or the like is suppressed even at a portion on the intake valve 21 side where the load is relatively large when pre-ignition occurs. Is set to Hereinafter, the wear-resistant ring 32 according to the present embodiment will be described with reference to FIGS. 3 and 4.

  As shown in FIG. 4, the ring groove 34 </ b> A is formed on the outer peripheral surface 33 of the wear-resistant ring 32 as described above. The wear-resistant ring 32 has a pair of opposed walls 35 and 36 that are opposed to each other with the ring groove 34A interposed therebetween, and a side wall 37 that connects the opposed walls 35 and 36 on the inner peripheral side.

  The distance between the pair of opposing walls 35, 36, that is, the width of the ring groove 34 </ b> A is the same length s <b> 1 over the circumferential direction of the wear-resistant ring 32. Moreover, the thickness of the side wall 37 is set to the same thickness s2 over the circumferential direction.

  On the other hand, each of the pair of facing walls 35 and 36 has the same thickness at each of the facing portions, but the thickness in the circumferential direction is not uniform, and a relatively thick portion and a thin portion are formed. I have. Specifically, in the pair of opposing walls 35 and 36, the portion on the intake valve 21 side (the portion on the left side in FIG. 3 and FIG. 4) among the respective portions in the circumferential direction is the thickest, and the thickness t1 It has become. That is, the intake valve 21 side portions of the pair of opposing walls 35 and 36 are thick portions 35A and 36A that are relatively thick in the circumferential direction. Note that the thickness t1 of the thick portions 35A and 36A is such that the thickness of the thick portions 35A and 36A is set to the thickness t1, thereby suppressing the deformation of the wear resistant ring 32 even if pre-ignition occurs. It is set to such a thickness that the wear-resistant ring 32 can have a strength capable of being

  On the other hand, in the pair of opposing walls 35 and 36, the thickness of the portion on the exhaust valve 22 side (the portion on the right side in FIG. 3 and FIG. 4) among the respective portions in the circumferential direction is the smallest, and the thickness is t2. (T1> t2). That is, the portions on the exhaust valve 22 side of the pair of opposing walls 35 and 36 are thin portions 35B and 36B that are relatively thin in the circumferential direction. And as shown in FIG. 4, in a pair of opposing wall 35,36, it is comprised so that the thickness may become thin gradually from thick part 35A, 36A to thin part 35B, 36B. In addition, the length in the radial direction of the opposing walls 35 and 36 is a uniform length t3 in the circumferential direction.

  Further, as described above, the thickness s2 of the side wall 37 and the length t3 in the radial direction of the pair of opposing walls 35 and 36 are uniform over the circumferential direction of the wear-resistant ring 32, respectively. The depth of the ring groove 34 </ b> A formed in 32 is uniform over the circumferential direction of the wear-resistant ring 32. Thereby, the piston ring 30A having a uniform shape in the circumferential direction can be fitted into the ring groove 34A.

The piston 30 of this embodiment has the wear ring 32 detailed above, and the internal combustion engine 10 of this embodiment is provided with the piston 30 having such a wear ring 32.
Next, the operation of this embodiment will be described.

  In the internal combustion engine 10 shown in FIG. 1, when pre-ignition occurs, the combustion pressure in the combustion chamber 15 becomes higher on the intake valve 21 side than on the exhaust valve 22 side. Therefore, the load acting on the piston 30 is larger on the intake valve 21 side than on the exhaust valve 22 side. In the present embodiment, as shown in FIG. 4, in the pair of opposing walls 35 and 36 of the wear-resistant ring 32 of the piston 30, the portions on the intake valve 21 side are the thick portions 35 </ b> A and 36 </ b> A. The strength of the portion on the intake valve 21 side is relatively high. Therefore, even if a large load is applied to a portion of the piston 30 on the intake valve 21 side due to the occurrence of pre-ignition, the wear-resistant ring 32 is suppressed from being deformed. Further, since the wear-resistant ring 32 has the thin portions 35B and 36B on the exhaust valve 22 side, the weight of the piston 30 is suppressed from becoming heavy.

According to the embodiment described above in detail, the following effects can be obtained.
(1) The piston 30 of this embodiment includes a wear-resistant ring 32. The wear-resistant ring 32 has a pair of opposing walls 35, 36 that are opposed to each other with a ring groove 34 </ b> A formed on the outer peripheral surface 33, and a side wall 37 that connects these opposing walls 35, 36 on the inner peripheral side. The pair of opposing walls 35 and 36 are not uniform in thickness in the circumferential direction, and include relatively thick thick portions 35A and 36A and relatively thin thin portions 35B and 36B.

  Accordingly, the thick portions 35A and 36A can be disposed on the side where the load received by the piston 30 is relatively large, that is, the intake valve 21 side in this embodiment, and the load received by the piston 30 is relatively The strength of the wear-resistant ring 32 at a large site can be relatively increased. Thereby, deformation | transformation etc. of the wear-resistant ring 32 can be suppressed also in the intake valve 21 side where the load which the piston 30 receives is comparatively large. On the other hand, since the thin-walled portions 35B and 36B are relatively thin, the wear-resistant ring 32 is compared with the case where the wear-resistant ring 32 is formed to have the same thickness as the thick-walled portions 35A and 36A over the entire circumference. Can be reduced in weight. In this way, deformation of the wear-resistant ring 32 can be suppressed while suppressing an increase in the weight of the piston 30.

  (2) The internal combustion engine 10 of the present embodiment includes a supercharger 40 and includes the piston 30 having the wear ring 32. Further, the thick portions 35A and 36A of the wear-resistant ring 32 are disposed on the intake valve 21 side, and the thin portions 35B and 36B are disposed on the exhaust valve 22 side.

  According to the experiment by the present inventor, in the internal combustion engine 10 provided with the supercharger 40, when pre-ignition occurs, the load (in-cylinder pressure) acting on the piston 30 is greater on the intake valve 21 side than on the exhaust valve 22 side. Has been confirmed. Therefore, in the present embodiment, the thick portions 35A and 36A of the wear-resistant ring 32 are disposed on the intake valve 21 side where the load acting on the piston 30 increases when pre-ignition occurs, while the load acting on the piston 30 The thin-walled portions 35B and 36B are arranged on the exhaust valve 22 side where is relatively small. Thereby, in the internal combustion engine 10 provided with the supercharger 40, the deformation | transformation etc. of the wear-resistant ring 32 can be suppressed also in the site | part where the load which the piston 30 receives by generation | occurrence | production of pre-ignition becomes comparatively large. Further, by setting the portions located on the exhaust valve 22 side in the wear-resistant ring 32 as the thin portions 35B and 36B, it is possible to suppress the weight of the piston 30 from becoming heavy.

In addition, this invention is not restricted to the aspect illustrated in the said embodiment, It can change and implement as shown below.
The wear-resistant ring is not limited to the configuration of the above embodiment, and the pair of opposing walls are formed so that the portion on the intake valve side is relatively thick and the portion on the exhaust valve side is relatively thin. It only has to be. For example, the wear-resistant ring may have a shape as shown in FIGS.

  The wear-resistant ring 50 shown in FIG. 5 is relatively thick in the circumferential direction of the opposing walls 55 and 56 in the region on the intake valve side of the pair of opposing walls 55 and 56 (the range indicated by the arrow A in FIG. 5). The thick portions 55A and 56A are formed. In addition, regions on the exhaust valve side of the pair of opposing walls 55 and 56 (ranges indicated by arrows B in FIG. 5) become thin portions 55B and 56B that are relatively thin in the circumferential direction of the opposing walls 55 and 56. ing. Further, the region between the thick portions 55A and 56A and the thin portions 55B and 56B (the range indicated by the arrow C in FIG. 5) gradually decreases in thickness from the thick portions 55A and 56A to the thin portions 55B and 56B. It is comprised so that it may become.

  Further, in the wear-resistant ring 60 shown in FIG. 6, regions on the intake valve side (range indicated by an arrow A in FIG. 6) in the pair of opposing walls 65 and 66 are thick portions 65 </ b> A and 66 </ b> A. Moreover, the area | region (range shown by the arrow B in FIG. 6) in the exhaust valve side in the opposing walls 65 and 66 is the thin part 65B and 66B. A part of the region between the thick portions 65A and 66A and the thin portions 65B and 66B (range indicated by an arrow C in FIG. 6) has a uniform thickness, and the thick portions 65A and 66A and the thin portion 65B. , 66B, which are intermediate thickness portions 65C, 66C. The regions between the thick portions 65A and 66A and the middle portions 65C and 66C gradually decrease in thickness from the thick portions 65A and 66A to the middle portions 65C and 66C, and the middle portions 65C and 66C The region between the thin portions 65B and 66B gradually decreases in thickness from the middle portions 65C and 66C to the thin portions 65B and 66B. As described above, in the embodiment shown in FIG. 6, the thicknesses of the opposing walls 65 and 66 are gradually reduced from the thick portions 65A and 66A to the thin portions 65B and 66B.

  As described above, in the wear-resistant rings 50 and 60 shown in FIGS. 5 and 6, the thick portions 55A, 56A, 65A, and 66A are disposed on the intake valve side of the pair of opposing walls 55, 56, 65, and 66, and the exhaust gas is exhausted. Thin portions 55B, 56B, 65B, 66B are arranged on the valve side. Therefore, deformation of the wear-resistant rings 50 and 60 can be suppressed even at a portion on the intake valve side where the load received by the piston is relatively large due to the occurrence of pre-ignition, and the wear-resistant rings 50 and 60 are disposed on the exhaust valve side. It is possible to suppress an increase in the weight of the piston by setting the portion to be positioned as the thin portions 55B, 56B, 65B, 66B.

  In each of the above embodiments, in the pair of opposing walls, the thicknesses of the opposing walls are the same at the opposing portions. However, in the pair of opposing walls, it is sufficient that the thickness of the portion on the intake valve side is thicker than the thickness of the portion on the exhaust valve side, and the thicknesses of the facing portions do not have to be the same. That is, in the embodiment shown in FIGS. 4, 5 and 6, the thicknesses of the thick portions 35A, 55A, 65A facing each other may be different from the thicknesses of the thick portions 36A, 56A, 66A. The thickness of the opposed thin portions 35B, 55B, and 65B may be different from the thickness of the thin portions 36B, 56B, and 66B. Further, in each of the above embodiments, both the pair of facing walls of the wear-resistant ring include a thick part and a thin part, but either one of the pair of opposing walls includes a thick part and a thin part. Also good. Moreover, in each said embodiment, although the thickness of a side wall is uniform thickness over the circumferential direction, the thickness of a side wall may differ for every site | part of the circumferential direction. For example, the side wall may be thicker on the intake valve side than on the exhaust valve side.

  -In the said embodiment, the thick part of a wear-resistant ring is arrange | positioned at the intake valve side, and the thin part is arrange | positioned at the exhaust valve side. However, the arrangement position of the thick part and the thin part of the wear-resistant ring may be different from the above-described embodiment. For example, the load (combustion pressure) acting on the piston may be biased due to the oscillation of the piston or the like, not at the time of abnormal combustion such as pre-ignition but at the time of combustion of a normal air-fuel mixture. Therefore, in the pair of opposed walls of the wear-resistant ring, the thickness of the portion where the load (combustion pressure) acting on the piston during normal combustion is relatively large is set to be a thick part that is relatively thick in the circumferential direction of the opposed wall. The thickness of the portion where the load (combustion pressure) acting on the piston during combustion is relatively small may be a thin portion that is relatively thin in the circumferential direction of the opposing wall. Thereby, it can suppress that the weight of a piston becomes heavy by aiming at the weight reduction of a wear-resistant ring, suppressing that a wear-resistant ring deform | transforms by the combustion pressure at the time of normal combustion.

  In the above embodiment, the wear-resistant ring and piston according to the present invention are applied to a gasoline engine equipped with a supercharger. However, the wear-resistant ring and piston according to the present invention can also be applied to a diesel engine or a gasoline engine without a supercharger. Further, the gasoline engine may have an in-cylinder injection valve that directs fuel into the combustion chamber. Also in these internal combustion engines, if the opposing wall of the wear-resistant ring includes a thick part and a thin part, and the thick part of the wear-resistant ring is arranged at a portion where the load acting on the piston is relatively large, While preventing the piston from becoming heavy, deformation of the wear-resistant ring can be suppressed.

  DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine, 11 ... Intake passage, 12 ... Throttle valve, 13 ... Fuel injection valve, 14 ... Cylinder, 15 ... Combustion chamber, 17 ... Spark plug, 18 ... Crankshaft, 19 ... Exhaust passage, 21 ... Intake valve, 22 ... Exhaust valve, 30 ... Piston, 30A ... Piston ring, 31 ... Piston body, 32, 50, 60 ... Wear-resistant ring, 33 ... Outer peripheral surface, 34, 34A ... Ring groove, 35, 36, 55, 56, 65, 66 ... opposing wall, 35A, 36A, 55A, 56A, 65A, 66A ... thick part, 35B, 36B, 55B, 56B, 65B, 66B ... thin part, 37 ... side wall, 40 ... supercharger, 41 ... compressor, 41A ... Compressor wheel, 42 ... Turbine, 42A ... Turbine wheel, 43 ... Bypass passage, 44 ... Waste gate valve, 65C ... Middle wall part, 66 ... medium build part.

Claims (4)

  An anti-wear ring having a pair of opposing walls facing each other across a ring groove formed on the outer peripheral surface and a side wall connecting the opposing walls on the inner peripheral side, wherein at least one of the pair of opposing walls has a thickness thereof A wear-resistant ring comprising a thick part and a thin part that are relatively thick in the circumferential direction. The wear resistant ring according to claim 1,
The ring groove and the pair of opposing walls are wear-resistant rings provided over the entire circumference of the outer peripheral surface. A piston provided with the wear-resistant ring according to claim 1 . An internal combustion engine comprising a supercharger,
A piston according to claim 3 ,
An internal combustion engine in which a thick portion of the wear-resistant ring is disposed on an intake valve side and the thin portion is disposed on an exhaust valve side.