JPH0571420A - Piston for slant engine - Google Patents

Abstract

PURPOSE:To inhibit oil intruded into an annular space formed between piston rings from moving toward a combustion chamber so as to prevent an increase in oil consumption. CONSTITUTION:A cylinder 2 for a slant engine using a piston 7 is inclined with respect to a vertical line. The piston 7 is provided with a piston main body 8 housed inside the cylinder 2 for reciprocating motion, and a plurality of piston rings (a second ring 13 and an oil ring 14) disposed around the piston main body 8 in a state separated from each other, for forming a second annular space 20 between the outer peripheral surface of the piston main body 8 and the inner circumferential surface of the cylinder 2. A communicating path 21 is formed in the piston main body 8. One end of the communicating path 21 is opened to the second annular space 20 in an upper portion beyond an oil storing portion while the other end thereof is opened to the inner surface of the piston main body 8 in an upper portion beyond the oil storing portion.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piston provided in a cylinder of a slant engine.

[0002]

2. Description of the Related Art Conventionally, for example, a general automobile in-line engine includes a cylinder extending vertically, and a piston having a compression ring and an oil ring mounted on the outer periphery of a piston body is disposed in the cylinder. ing. In this type of engine, when the pressure in the combustion chamber becomes negative, the air on the crankcase side is drawn into the combustion chamber through between the inner circumference of the cylinder and the outer circumference of the piston. There is a problem that it is carried into the combustion chamber together with the air and burned and consumed.

Therefore, in the "piston" of Japanese Utility Model Laid-Open No. 56-122748, as a technique for solving such a problem, the inner and outer peripheries of the piston body immediately above the oil ring are communicated by a vent hole. According to this piston, even if the combustion chamber has a negative pressure, the air on the crankcase side passes through the ventilation hole, passes between the inner circumference of the cylinder and the outer circumference of the piston, and reaches the combustion chamber. Oil is not carried into the combustion chamber with the air. In this way, it is possible to reduce the oil consumption.

As opposed to the general vehicle-mounted engine described above,
In recent years, a so-called slant engine, in which a cylinder is inclined by a predetermined angle with respect to a vertical line, has come to be mounted on an automobile, and it is conceivable to apply the technique of the above publication to this slant engine.

[0005]

However, if the technique disclosed in the above publication is applied to a piston for a slant engine as it is, as shown in FIGS. 32 and 33, a lower part of the space between the outer circumference of the piston and the inner circumference of the cylinder. Towards the oil F
As the water flows down and accumulates, the following new problems arise.

That is, when a load is applied to the slant engine and the pressure P1 on the combustion chamber 52 side becomes higher than the pressure P2 on the crankcase 53 side (P1> P2), the ring surrounded by the compression ring 55 and the oil ring 56. The combustion gas on the combustion chamber 52 side enters the space 57, and the pressure in the annular space 57 rises. At this time, if the vent hole 54 is located below the piston body 51 and is immersed in the oil F, the combustion gas cannot escape from the vent hole 54. Therefore, the pressure in the annular space 57 rises, and this pressure pushes the oil F toward the combustion chamber 52 side as shown by the arrow in FIG. Then, the oil F is burned in the combustion chamber 52 and the oil consumption increases.

When the engine brake is applied and the pressure P1 on the combustion chamber 52 side becomes lower than the pressure P2 on the crankcase 53 side (P1 <P2), the vent hole 5 is opened.
When 4 is located below the piston body 51, the oil F in the annular space 57 is sucked toward the combustion chamber 52.
Therefore, also in this case, the oil F is burned in the combustion chamber 52, and the oil consumption amount increases.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to prevent the oil that has entered the annular space from moving to the combustion chamber side and prevent an increase in oil consumption. To provide a piston for a slant engine.

[0009]

In order to achieve the above object, in a slant engine piston of the present invention, a cylinder is inclined with respect to a vertical line, a combustion chamber is arranged on the upper opening end side of the cylinder, and a lower opening is provided. It is used for a slant engine having a crankcase with oil stored on the end side, and is mounted on the outer circumference of the piston body in a state of being separated from each other A plurality of piston rings that form an annular space between the outer peripheral surface of the piston body and the inner peripheral surface of the cylinder; and one end of the piston ring that is provided in the piston body and that is above the portion where oil is stored. Of the piston body, the other end of which is the inner surface of the piston main body above the portion where the oil is stored, and the above-mentioned annular space above the portion where the oil is stored. And a communication passage opening into different annular space or the combustion chamber.

[0010]

[Function] Since the cylinder of the slant engine is inclined with respect to the vertical line, when the slant engine is in operation,
The oil for lubrication is stored in the lower part of the cylinder and piston by gravity. Then, a part of this oil enters the annular space between the adjacent piston rings.

Here, for example, when a load is applied to the slant engine and the pressure of the combustion gas in the combustion chamber becomes higher than the pressure of the air in the crankcase, the combustion gas enters the annular space, and as a result, in the annular space. Pressure is about to rise. However, the combustion gas in this annular space is
An inner surface of the piston body above the portion where the oil is stored, the annular space above the portion where the oil is stored, through a communication passage that is provided above the portion where the oil is stored in the piston body. To a different annular space or combustion chamber. By derivation of this combustion gas,
The pressure increase in the annular space is suppressed. As a result, the oil that has entered the annular space is prevented from being pushed out toward the combustion chamber.

Further, when the present invention is applied to a slant engine mounted on a vehicle, when the engine brake is applied and the pressure of the combustion gas on the combustion chamber side becomes lower than the pressure of the air on the crankcase side, the annular space is formed. The oil inside tries to be sucked toward the combustion chamber side. However, only the air in the crankcase passes through the communication passage, passes through the annular space, and is sucked into the combustion chamber. As a result, the oil that has entered the annular space is prevented from being carried to the combustion chamber side.

[0013]

【Example】

(First Embodiment) A first embodiment in which the present invention is embodied in a piston for a slant engine mounted on a vehicle will be described with reference to FIGS.
It will be described with reference to FIG.

FIG. 2 is a slant engine 1 according to this embodiment.
It is sectional drawing which shows some. In this slant engine 1, the cylinder 2 is inclined with respect to the vertical line L at an inclination angle θa of 45 ° or more and 90 ° or less (θa = 75 ° in this embodiment). Further, in the slant engine 1, the combustion chamber 3 is arranged on the upper opening end side of the cylinder 2, and the crankcase 4 in which oil is stored is arranged on the lower opening end side.

In the cylinder 2, a piston 7 connected to a crankshaft 6 by a connecting rod 5 is arranged. The piston 7 has a cylindrical shape with a lid and is reciprocally inserted into the cylinder 2 and a plurality of pistons (three in this embodiment) mounted on the outer periphery of the piston body 8. It is equipped with a ring.

That is, as shown in FIG. 1, a top ring groove 9, a second ring groove 10 and an oil ring groove 11 are arranged parallel to each other in this order from the combustion chamber 3 side to the crankcase 4 side on the outer periphery of the piston body 8. It is formed in the state. Then, the top ring 12 is mounted in the top ring groove 9, and the second ring 13 is fitted in the second ring groove 10.
Is attached, and the oil ring 14 is attached to the oil ring groove 11. The top ring 12, the second ring 13 and the oil ring 14 constitute the plurality of piston rings. The top ring 1
2 and the second ring 13 are for preventing gas leakage in the compression stroke and the explosion stroke, and the oil ring 14
Is for scraping off excess oil adhering to the inner peripheral surface of the cylinder 2 to prevent the oil from entering the combustion chamber 3. A slit 15 extending in the circumferential direction is formed on the inner wall of the oil ring groove 11 to absorb thermal expansion of the piston body 8.

The above-mentioned three piston rings 12-14
By mounting, three lands are formed on the outer peripheral surface of the piston body 8. That is, the outer peripheral surface of the piston body 8 closer to the combustion chamber 3 than the top ring 12 is the top land 16. A second land 17 is formed on the outer peripheral surface of the piston body 8 sandwiched by the top ring 12 and the second ring 13. Further, the outer peripheral surface of the piston body 8 sandwiched by the second ring 13 and the oil ring 14 forms a third land 18.

A first annular space 19 is formed by the top ring 12, the second ring 13, the second land 17, a part of the top ring groove 9, a part of the second ring groove 10 and the inner peripheral surface of the cylinder 2. ing. In addition, the second ring 13, the oil ring 14, the third land 18, a part of the second ring groove 10, a part of the oil ring groove 11 and the inner peripheral surface of the cylinder 2 form a second ring.
The annular space 20 is formed.

In the slant engine 1, since the cylinder 2 is inclined with respect to the vertical line L at the inclination angle θa (= 75 degrees), as shown in FIG.
Is stored in the lower portion of the cylinder 2 and the piston 7 due to gravity. For this reason, the hydraulic pressure in the same portion becomes excessively large, and a part of the oil F cannot be completely scraped off by the oil ring 14 and goes up to the third land 18. As a result, the oil F is stored in the lower part of the third land 18. Assuming that the oil storage portion of the piston body 8 at this time is B, the oil storage portion B has a predetermined angle on both sides in the circumferential direction with reference to a vertical line L passing through the axis A of the piston body 8 as shown in FIG. It is expressed in the range of θb (15 degrees in this embodiment).
The predetermined angle θb has different values depending on the inclination angle θa of the cylinder 2 and the tension of each piston ring.

In addition, the piston body 8 has a communication passage 2
1 is provided. One end of this communication passage 21 is open to the third land 18 above the oil storage portion B, that is, the second annular space 20 (see FIG. 1). The communication passage 21 extends straight toward the axis A of the piston body 8, and the other end of the communication passage 21 is open to the inner surface of the piston body 8 above the oil storage portion B.

Next, the operation and effect of this embodiment constructed as described above will be described. 1 and 3, when the slant engine 1 is loaded and the combustion gas pressure P1 on the combustion chamber 3 side becomes higher than the air pressure P2 on the crankcase 4 side (P1> P2), the combustion chamber 3 side Of the combustion gas of the second annular space 20 through the first annular space 19
Get inside. As a result, the pressure in the second annular space 20 tends to rise.

However, in this embodiment, one end of the communication passage 21 is opened to the third land 18 above the oil storage portion B, and the other end of the communication passage 21 is located above the oil storage portion B. Of the piston body 8 is opened. Therefore, the combustion gas in the second annular space 20 passes through the piston main body 8 via the communication passage 21 and is guided to the crankcase 4 side. The derivation of the combustion gas suppresses the pressure rise of the combustion gas in the second annular space 20. Therefore, unlike the prior art in which the vent hole 54 may be positioned below the slope, in the present embodiment, the oil F that has risen to the second annular space 20 is prevented from being pushed out to the combustion chamber 3 side, Unnecessary consumption of oil F due to combustion can be prevented.

Further, for example, when the engine brake is applied and the pressure P1 of the combustion gas on the combustion chamber 3 side becomes the crankcase 4
When it becomes lower than the pressure P2 of the side air (P1 <P2),
The oil F in the second annular space 20 tends to be sucked toward the combustion chamber 3 side. However, in the present embodiment, the air in the crankcase 4 passes through the communication passage 21 and the second annular space 2
It is sucked into the combustion chamber 3 through 0 and the first annular space 19. Therefore, unlike the prior art, in this embodiment, the oil F that has risen to the second annular space 20 is prevented from being carried to the combustion chamber 3 side, and unnecessary consumption of the oil F due to combustion is prevented. it can.

FIG. 5 is a graph showing the relationship between engine speed and oil consumption when the slant engine 1 is loaded. In the figure, the solid line shows the case where the communication passage 21 is provided as described above (this embodiment), and the broken line shows the communication passage 2
The case where 1 is not provided (comparative example) is shown. From this figure, it can be seen that the effect of reducing oil consumption by the communication passage 21 can be seen in almost all rotation speed regions except the low rotation speed region.

Thus, in this embodiment, the piston body 8
Is provided with a communication passage 21, one end of which is opened to the second annular space 20 above the oil storage portion B, and the other end is opened to the inner surface of the piston body 8 above the oil storage portion B. Let Therefore, when the slant engine 1 is in operation, the oil F enters the lower portion of the second annular space 20, but the oil F is prevented from moving to the combustion chamber 3 side and being burned, thereby increasing the oil consumption. Can be prevented. (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. In the present embodiment, the communication passage 21 is bent in the piston body 8 and the other end of the communication passage 21 is opened to the inner wall of the slit 15 above the oil storage portion B. It differs from the example.

Therefore, according to this embodiment, the second annular space 20 and the inside of the piston body 8 are communicated by the communication passage 21. Therefore, similarly to the first embodiment, it is possible to prevent the oil F that has entered the second annular space 20 from moving to the combustion chamber 3 side and prevent an increase in oil consumption. (Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS.
It will be explained based on.

In the present embodiment, in the second ring groove 10 above the oil reservoir B, a notch 22 is formed in a part of the inner wall 10a on the crankcase 4 side. The surface 22a of the notch 22 on the crankcase 4 side is an inclined surface that is separated from the second ring 13 as it approaches the third land 18. Then, as shown in FIG. 8, with the second ring 13 in contact with the inner wall 10a, the notch 22 and the second ring groove 1 are formed.
A communication passage 21 is formed by a part of 0.

Therefore, one end of this communication passage 21 opens into the second annular space 20 above the oil storage portion B, and the other end is the first annular space above the oil storage portion B. It means that it is open to the annular space 19. The configuration other than the above is the same as that of the first embodiment.

According to this embodiment, only when the pressure P1 of the combustion gas on the side of the combustion chamber 3 becomes lower than the pressure P2 of the air on the side of the crankcase 4 (P1 <P2), the following actions and effects are obtained. Play. That is, under this condition, the oil F in the second annular space 20 tends to be sucked toward the combustion chamber 3 side, but the combustion gas in the second annular space 20 is
As shown by an arrow in FIG. 8, the air is sucked into the first annular space 19 through the communication passage 21. Therefore, according to the present embodiment, the oil F that has risen to the second annular space 20 is prevented from being carried into the combustion chamber 3 side when the above condition (P1 <P2) is satisfied, and the oil F due to combustion is Unnecessary consumption can be prevented. (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIGS.

This embodiment is different from the third embodiment in that a groove 23 is formed in the second ring groove 10 on the inner wall 10a of the crankcase 4 side instead of the notch 22. The groove 23 extends straight from the third land 18 toward the axial center A of the piston body 8 and reaches a position deeper than the second ring groove 10. The surface 23 a of the groove 23 on the crankcase 4 side is substantially parallel to the second ring 13. Then, as shown in FIG. 11, when the second ring 13 is in contact with the inner wall 10a,
The groove 23 and a part of the second ring groove 10 form a communication passage 21.

Therefore, according to the present embodiment, the groove 23 extends to a position deeper than the second ring groove 10 in addition to the same operation and effect as the third embodiment, so that the first ring of combustion gas is formed. Suction into space 19 is the second ring 1
It is performed smoothly without being blocked by 3. (Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to FIGS.

This embodiment differs from the third embodiment in that a notch 22 is formed in a part of the inner wall 11b on the combustion chamber 3 side in the oil ring groove 11 above the oil storage portion B. ing. The surface 22b of the notch 22 on the combustion chamber 3 side is located closer to the oil ring 1 as it approaches the third land 18.
It is an inclined surface that is separated from the No. 4. Then, as shown in FIG. 14, the notch 22 and the oil ring groove 11 are formed.
And a slit 15 forms a communication passage 21. Therefore, one end of the communication passage 21 is opened to the second annular space 20 above the oil storage portion B, and the other end is opened to the inner surface of the piston body 8 above the oil storage portion B. It will be.

According to this embodiment, the same operation and effect as those of the second embodiment can be obtained. That is, when the pressure P1 of the combustion gas on the combustion chamber 3 side is higher than the pressure P2 of the air on the crankcase 4 side (P1> P2), the combustion gas on the combustion chamber 3 side enters the second annular space 20. Although entering, the combustion gas escapes into the piston body 8 through the communication passage 21. Further, when the pressure P1 of the combustion gas on the combustion chamber 3 side becomes lower than the pressure P2 of the air on the crankcase 4 side (P1 <P
In 2), the combustion gas in the piston body 8 is communicated with the communication passage 21,
It is sucked into the combustion chamber 3 through the second annular space 20 and the first annular space 19. Therefore, the second embodiment also
Oil F rising to the annular space 20 of the combustion chamber 3
It is possible to prevent the oil F from being unnecessarily consumed due to combustion. (Sixth Embodiment) Next, a sixth embodiment of the present invention will be described with reference to FIGS.

In this embodiment, in the inner wall 11b of the oil ring groove 11 on the combustion chamber 3 side, the groove 2 is used instead of the notch 22.
3 is different from the fifth embodiment. This groove 23 extends from the third land 18 to the axis A of the piston body 8.
It extends straight toward and reaches a position deeper than the oil ring groove 11. The surface 23b of the groove 23 on the combustion chamber 3 side is substantially parallel to the oil ring 14. And FIG.
As shown by 6, the groove 23, a part of the oil ring groove 11 and the slit 15 constitute a communication passage 21.

Therefore, according to this embodiment, the groove 23 extends to a position deeper than the oil ring groove 11 in addition to the same operation and effect as the fifth embodiment, so that the second annular space 20 can be obtained. The movement of the combustion gas and the air between the piston body 8 and the piston body 8 is smoothly performed without being blocked by the oil ring 14. (Seventh Embodiment) Next, a seventh embodiment of the present invention will be described with reference to FIGS. In this embodiment, the communication passage 21
The first embodiment is different from the first embodiment in that one end is opened at the boundary portion between the inner wall 10a of the second ring groove 10 on the crankcase 4 side and the third land 18.

Therefore, also in the present embodiment, similarly to the first embodiment, it is possible to prevent the oil F that has entered the second annular space 20 from moving to the combustion chamber 3 side and prevent an increase in oil consumption. .. (Eighth Embodiment) Next, an eighth embodiment of the present invention will be described with reference to FIG. In this embodiment, one end of the communication passage 21 is
This is different from the first embodiment in that the top ring groove 9 is opened at an inner wall 9a on the crankcase 4 side. In this case, even if the oil F enters the first annular space 19, it is possible to prevent the oil F from moving to the combustion chamber 3 side and prevent an increase in oil consumption. (Ninth Embodiment) Next, a ninth embodiment of the present invention will be described with reference to FIG. In this embodiment, one end of the communication passage 21 is opened by the third land 18, and the other end is opened by the second land 17.
It is different from the first embodiment in that it is opened by.
That is, one end of the communication passage 21 is opened to the second annular space 20, and the other end is opened to the first annular space 19.

Therefore, according to this embodiment, only when the pressure P1 of the combustion gas on the side of the combustion chamber 3 becomes lower than the pressure P2 of the air on the side of the crankcase 4 (P1 <P2), the third embodiment described above can be used. The same action and effect as the above are obtained.

The present invention is not limited to the configuration of the above-mentioned embodiment, and may be arbitrarily modified within the scope not departing from the spirit of the invention as follows, for example. (1) If both ends of the communication passage 21 are open above the oil reservoir B, the number and shape of the communication passage 21 are not particularly limited.

(2) In the first and second embodiments, one end of the communication passage 21 is opened by the third land 18 of the piston body 8, but as shown in FIGS. 21 and 22,
One end of these communication passages 21 may be opened at the second land 17 facing the first annular space 19.

(3) In the third and fourth embodiments, the notch 22 and the groove 23 are formed on the inner wall 10a of the second ring groove 10 on the crankcase 4 side, but as shown in FIG. The notch 22 may be formed on the inner wall 9a of the top ring groove 9 on the crankcase 4 side, or the groove 23 may be formed on the inner wall 9a of the top ring groove 9 on the crankcase 4 side as shown in FIG. ..

(4) In the fifth and sixth embodiments, the notch 22 and the groove 23 are formed on the inner wall 10b of the oil ring groove 11 on the combustion chamber 3 side, but as shown in FIG. 22 may be formed on the inner wall 10b of the second ring groove 10 on the side of the combustion chamber 3, or the groove 23 may be formed on the inner wall 10b of the second ring groove 10 on the side of the combustion chamber 3 as shown in FIG.

(5) In the seventh embodiment, one end of the communication passage 21 is opened at the boundary between the inner wall 10a of the second ring groove 10 on the crankcase 4 side and the third land 18, but as shown in FIG. In addition, one end of the communication passage 21 may be opened at the boundary between the inner wall 11b of the oil ring groove 11 on the combustion chamber 3 side and the third land 18, or one end of the communication passage 21 may be opened at the second ring groove as shown in FIG. The opening 10 may be opened at the boundary between the inner wall 10 b of the combustion chamber 3 on the side of the combustion chamber 3 and the second land 17.

(6) In the ninth embodiment, one end of the communication passage 21 is opened at the third land 18 and the other end is opened at the second land 17, but as shown in FIG. One end may be opened at the second land 17 and the other end may be opened at the top land 16. In this case,
One end of the communication passage 21 opens in the first annular space 19, and the other end opens in the combustion chamber 3.

(7) As shown in FIGS. 30 and 31, a check valve structure may be added to the communication passage 21 of the first embodiment. The check valve structure of FIG. 30 includes a reed valve 31 that opens and closes the communication passage 21 from the inner surface side of the piston body 8, and a valve fixing screw 32 that fixes the reed valve 31 to the inner surface of the piston body 8. In addition, the check valve structure of FIG.
The ball valve 33 is provided in the middle of the communication passage 21, and the spring 34 biases the ball valve 33 toward the outer peripheral surface of the piston body 8. In any case, the second
The gas is allowed to flow from the annular space 20 into the piston body 8 and the flow of gas, oil, etc. from the piston body 8 to the second annular space 20 is blocked.

Therefore, the oil splashed by the rotational movement of the crankshaft 6 and the oil splashed on the inner surface of the piston body 8 by the oil jet etc.
Even if it tries to enter the inside of 1, it is blocked by the above-mentioned check valve structure. Thereby, the amount of oil in the second annular space 20 can be suppressed.

(8) The present invention may be embodied in a piston having two or four or more piston rings mounted on the outer circumference of the piston body 8.

[0047]

As described in detail above, according to the present invention, a communicating passage is provided in the piston body, one end of which is opened in an annular space above the portion where oil is stored, and the other end is Since the inner surface of the piston body is located above the portion where the oil is stored, and the annular space or the combustion chamber different from the annular space above the portion where the oil is stored is opened, the oil that has entered the annular space It has an excellent effect that it is possible to prevent the oil consumption from increasing toward the combustion chamber side and prevent the oil consumption from increasing.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a piston and a cylinder for a slant engine according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a part of the thrust engine in the first embodiment.

FIG. 3 is a front view of a piston in the first embodiment.

4 is a cross-sectional view taken along the line CC of FIG.

FIG. 5 is a graph showing the relationship between engine speed and oil consumption in the first embodiment.

FIG. 6 is a partial sectional view of a piston and a cylinder in a second embodiment.

FIG. 7 is a partial sectional view of a piston and a cylinder in a third embodiment.

FIG. 8 is a partial cross-sectional view in the vicinity of a second ring for explaining the flow of combustion gas in the third embodiment.

FIG. 9 is a partial perspective view of the piston body near the notch in the third embodiment.

FIG. 10 is a partial cross-sectional view of a piston and a cylinder in a fourth embodiment.

FIG. 11 is a partial cross-sectional view in the vicinity of a second ring for explaining the flow of combustion gas in the fourth embodiment.

FIG. 12 is a partial perspective view of the piston body near the groove in the fourth embodiment.

FIG. 13 is a partial sectional view of a piston and a cylinder in a fifth embodiment.

FIG. 14 is a partial cross-sectional view in the vicinity of an oil ring for explaining the flow of combustion gas in the fifth embodiment.

FIG. 15 is a partial sectional view of a piston and a cylinder in a sixth embodiment.

FIG. 16 is a partial cross-sectional view of the vicinity of an oil ring for explaining the flow of combustion gas in the sixth embodiment.

FIG. 17 is a partial sectional view of a piston and a cylinder in a seventh embodiment.

FIG. 18 is a partial perspective view of the piston body near the communication passage in the seventh embodiment.

FIG. 19 is a partial sectional view of a piston and a cylinder in an eighth embodiment.

FIG. 20 is a partial sectional view of a piston and a cylinder in a ninth embodiment.

FIG. 21 is a partial cross-sectional view around a piston showing another example of the communication passage in the first embodiment.

FIG. 22 is a partial cross-sectional view around a piston showing another example of the communication passage in the second embodiment.

FIG. 23 is a partial cross-sectional view around a piston showing another example of the communication passage in the third embodiment.

FIG. 24 is a partial cross-sectional view around the piston showing another example of the communication passage in the fourth embodiment.

FIG. 25 is a partial cross-sectional view around a piston showing another example of the communication passage in the fifth embodiment.

FIG. 26 is a partial cross-sectional view around a piston showing another example of the communication passage in the sixth embodiment.

FIG. 27 is a partial cross-sectional view around a piston showing another example of the communication passage in the seventh embodiment.

FIG. 28 is a partial cross-sectional view around the piston showing another example of the communication passage in the seventh embodiment.

FIG. 29 is a partial cross-sectional view around the piston showing another example of the communication passage in the ninth embodiment.

FIG. 30 is a partial cross-sectional view around the piston showing a state where a check valve structure is added to the communication passage of the first embodiment.

FIG. 31 is a partial cross-sectional view around the piston showing a state where a check valve structure is added to the communication passage of the first embodiment.

FIG. 32 is a partial front view of a piston in the related art.

FIG. 33 is a partial cross-sectional view of a piston and a cylinder in the related art.

[Explanation of symbols]

1 ... Slant engine, 2 ... Cylinder, 3 ... Combustion chamber, 4
... crankcase, 8 ... piston body, 12 ... top ring forming piston ring, 13 ... second ring forming piston ring, 14 ... oil ring forming piston ring, 19 ... first annular space, 20 ... second 2 annular space, 21 ... communication passage, B ... oil storage part, F
... oil, L ... vertical line

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kimitaka Saito 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute, Inc.

Claims (1)

[Claims] 1. A slant engine in which a cylinder is inclined with respect to a vertical line, a combustion chamber is arranged on the upper opening end side of the cylinder, and a crankcase in which oil is stored is arranged on the lower opening end side. And a piston body reciprocally disposed in the cylinder, and a piston body mounted on the outer circumference of the piston body in a state of being separated from each other, and an annular shape between the outer circumferential surface of the piston body and the inner circumferential surface of the cylinder. A plurality of piston rings that form a space, and provided on the piston body, one end of which opens into an annular space above the portion where oil is stored, and the other end of which is
An inner surface of the piston main body above the oil storage portion, an annular space different from the annular space above the oil storage portion, or a communication passage opening to a combustion chamber. Piston for slant engine.