JPH04347352A - Engine - Google Patents

Abstract

PURPOSE:To provide an engine that is made up of forming a deflecting space, where gas pressure out of an engine conbustion chamber is conducted, in space between a side wall inner surface of a cylinder and a side face of a piston facing to this side wall inner surface, and floating the piston from the side wall inner surface of the cylinder by dint of gas pressure in this deflecting space, while it is able to get rid of any contact with the cylinder side wallat a side upper part at a counter thrust side of the piston and, what is more, there is no occurrence of galling or the like. CONSTITUTION:This engine is made up of forming a deflecting space 11, where gas pressure out of an engine canbustion chamber 8 is conducted, in space between a side wall inner surface 10 of a cylinder 1 and a side face 9 of a piston 2 facing to this inner surface 10 so as to make a pressure-receiving area of the side face 9 of the piston 2 accepting the gas pressure larger than a side face 15 at a counter-thrust side of the piston 2 at a side of a side face 16 at a thrust side being opposed to the side face 15 of this counter-thrust side, and installing a connecting rod 14 in the piston after making a piston pin 13 being connected to the piston 2 eccentric to the counter thrust side from a center 32 of the piston 2.

Description

[Detailed description of the invention]

0001

FIELD OF THE INVENTION This invention relates to reciprocating engines.

0002

2. Description of the Related Art In a reciprocating engine, a technique has been proposed in which rollers are provided on the side surface of the piston in order to reduce the sliding frictional resistance between the inner surface of the cylinder side wall and the side surface of the piston during the reciprocating motion of the piston.

0003

[Problems to be Solved by the Invention] However, with the technology of providing such rollers, the weight of the piston increases and the inertia of the piston during its reciprocating motion increases, resulting in poor engine response and, for example, poor acceleration performance. etc., the driving performance deteriorates. Therefore, a gas chamber is formed near the skirt portion of the piston, between the inner surface of the side wall of the cylinder and the side surface of the piston facing the inner surface of the side wall, into which the gas pressure from the engine combustion chamber is guided. A technique has been proposed in which the piston is floated from the inner surface of the side wall of the cylinder using gas pressure to reduce the sliding frictional resistance between the inner surface of the cylinder side wall and the side surface of the piston during the reciprocating motion of the piston.

However, in the proposed technology, a passage for guiding gas pressure from the engine combustion chamber to the gas chamber is provided in the piston, and a check valve is provided in this passage. Although the technique is satisfactory in air-floating the piston, the construction is somewhat complex.

[0005] Furthermore, in order to facilitate the introduction of gas pressure from the engine combustion chamber and simplify the structure, a technique has also been proposed in which such a gas chamber is formed near the top surface of the piston that defines the engine combustion chamber. However, such a gas chamber
In many cases, the piston is formed so that gas pressure applies a force to the piston from the thrust side side to the anti-thrust side side, but in this case, the gas pressure in the gas chamber causes the piston to rotate (oscillate). As a result, the upper part of the anti-thrust side surface of the piston comes into contact with the cylinder side wall, which may cause an inconvenient situation such as galling.

The present invention has been made in view of the above points, and its object is to prevent gas pressure from the engine combustion chamber between the inner surface of the side wall of the cylinder and the side surface of the piston facing the inner surface of the side wall. This is an engine in which a biased space is formed in which the piston is guided, and the piston is floated from the inner surface of the side wall of the cylinder by the gas pressure in this biased space.The structure is simple and has excellent durability. It is an object of the present invention to provide an engine which can eliminate the contact of the cylinder with the side wall of the cylinder and which does not cause galling or the like.

[0007]

[Means for Solving the Problems] According to the present invention, the above object is such that the pressure receiving area of the side surface of the piston that receives gas pressure is larger than that of the side surface of the piston on the anti-thrust side that is opposite to the side surface of the piston on the anti-thrust side. so that it gets bigger on the sides,
A biased space is formed between the inner surface of the side wall of the cylinder and the side surface of the piston facing the inner surface of the side wall, into which gas pressure from the engine combustion chamber is guided. This is achieved by an engine having a piston eccentric to the side.

According to the present invention, the above object is achieved by gradually increasing the distance from the top surface of the piston that defines the engine combustion chamber from the anti-thrust side of the piston to the thrust side opposite to the anti-thrust side. This can also be achieved by an engine in which a piston ring is provided on the side of the piston adjacent to the top surface of the piston to increase the length of the piston, and a piston pin that connects the connecting rod to the piston is eccentric from the center of the piston toward the anti-thrust side. Ru.

Further, according to the present invention, the above object is such that the pressure receiving area of the piston side surface that receives gas pressure from the engine combustion chamber is larger than that of the anti-thrust side surface of the piston, which is opposite to the anti-thrust side surface. This can also be achieved by an engine in which a piston ring is provided on the side of the piston so that it is larger on the side, and a piston pin that connects the connecting rod to the piston is provided on the piston eccentrically from the center of the piston toward the anti-thrust side.

[0010] According to the present invention, the above-mentioned object is to provide a first cylinder located between a side surface of the piston and an inner surface of the cylinder side wall facing the side surface of the piston and adjacent to the upper surface of the piston defining an engine combustion chamber. A gas passage communicating between an annular gas chamber defined between a piston ring and a second piston ring disposed adjacent to the first piston ring and an engine combustion chamber is provided; The first and second piston rings are provided on the piston so that the distance between the piston rings gradually increases from the anti-thrust side of the piston to the thrust side opposite to the anti-thrust side. This can also be achieved by an engine in which the piston is provided with a piston pin that connects the connecting rod to the piston and is eccentric from the center of the piston toward the anti-thrust side.

Furthermore, according to the present invention, the above object is such that the pressure receiving area of the side surface of the piston that receives gas pressure is larger on the side surface on the thrust side opposite to the side surface on the anti-thrust side of the piston than on the side surface on the anti-thrust side of the piston. a first piston ring disposed between a side surface of the piston and an inner surface of a cylinder side wall facing the side surface of the piston and adjacent to an upper surface of the piston defining an engine combustion chamber; A gas chamber communicating with the engine combustion chamber via a gas passage is formed between the piston ring and a second piston ring disposed adjacent to the piston ring, and a piston pin connecting the connecting rod to the piston is arranged opposite from the center of the piston. This can also be achieved by an engine having a piston eccentrically placed on the thrust side.

The amount of eccentricity of the piston pin in the present invention is:
Any value that can satisfactorily cancel the moment of rotation of the piston due to the gas pressure in the biased space may be used, but in one preferred example, the value is selected from approximately 0.5 mm to 2.7 mm for a piston diameter of 80 mm. be done.

[Operation] In the engine of the present invention configured as described above,
The inner surface of the side wall of the cylinder and the inner surface of this side wall are designed so that the pressure receiving area of the side surface of the piston that receives gas pressure is larger on the side surface on the thrust side opposite to the side surface on the anti-thrust side than on the side surface on the anti-thrust side of the piston. Since a biased space is formed between the opposing sides of the piston to which the gas pressure from the engine combustion chamber is guided, the piston is able to absorb the gas from the engine combustion chamber within the cylinder according to the difference in pressure receiving area based on this biased space. As a result of air floating due to pressure,
The sliding frictional resistance with the inner surface of the cylinder side wall is reduced and the piston moves reciprocatingly, and as a result, the piston pin that connects the connecting rod to the piston is eccentric from the center of the piston toward the anti-thrust side, and as a result, the gas chamber The rotational moment due to the reaction force from the connecting rod acting in the opposite direction to the moment of rotation of the piston due to the gas pressure in the biasing space is increased, so that rocking of the piston due to the gas pressure in the biasing space is preferably prevented.

The present invention will be explained below based on preferred embodiments shown in the drawings. This will make the invention and further inventions clear.

It should be noted that the present invention is not limited to these specific examples in any way.

[0015]

[Specific Example] In FIG. 1, piston rings 3 and 4 and an oil paddle ring 5 are fitted above a piston 2 arranged in a cylinder 1. The piston ring 3 adjacent to the upper surface 7 of the piston 2 that defines the engine combustion chamber 8 is located on the thrust side, which is located at a distance from the upper surface 7 of the piston 2 from the anti-thrust side surface 15 of the piston 2 to the anti-thrust side surface 15 of the piston 2. It is provided on the side surface 9 of the piston 2 at an angle with respect to the upper surface 7 of the piston 2 so that it becomes gradually longer toward the side surface 16 of the piston 2, in other words, so that the distance D2 is longer than the distance D1. . Thus, in this example, the side surface 9 of the piston 2 and the inner side wall 1 of the cylinder 1 are arranged between the upper surface 7 of the piston 2 defining the engine combustion chamber 8 and the piston ring 3 adjacent to the engine combustion chamber 8.
The annular space 11 between 0 and 0 is a biased space.

The piston ring 4 adjacent to the piston ring 3 is arranged parallel to the piston ring 3 in this example,
It is provided on the side surface 9 of the piston 2 so as to be inclined with respect to the upper surface 7 of the piston 2 . An oil ring 5 further provided on the piston 2 is arranged parallel to the upper surface 7 of the piston 2 and provided on a side surface 9 of the piston 2.

One end of a connecting rod 14 is connected to the piston 2 via a piston pin 13, and the other end of the connecting rod 14 is connected to a crankshaft (not shown). The piston pin 13 is attached to the piston 2 so that its center 31 is offset from the center 32 of the piston 2 by a distance D3 toward the side surface 15, which is the anti-thrust side.
The piston 2 swings in the A direction about the center 31 due to the reciprocating movement of the piston 2.

In the engine configured as described above, the gas pressure generated by explosion in the engine combustion chamber 8 during the explosion stroke is as follows:
It is also introduced into an annular biased space 11 which is also an annular gas chamber. The piston 2 creates a space 1 based on this introduced gas pressure.
In response to the biased side pressure at 1, the inner surface of the side wall 1
0, especially floating on the side wall inner surface 10 on the thrust side side surface 16 side. The piston 2, which is floated against the inner surface of the side wall 10 by gas pressure, can reciprocate with extremely low sliding friction resistance, thereby improving the fuel efficiency of the engine. By the way, the piston 2 which receives the side pressure of the biased gas in the space 11 from above receives a rotation (swinging) moment in the counterclockwise direction in FIG.
In the above-mentioned engine in which the piston pin 13 is attached to the piston 2 so as to be eccentric to the side surface 15 which is the anti-thrust side by a distance D3 from the center, the center is not eccentric from the center 32 of the piston 2, in other words, the center is not eccentric from the center 32 of the piston 2. center 32
Compared to an engine in which the piston pin 13 is attached to the piston 2 in accordance with As a result of the increased clockwise rotational moment due to the force, it is possible to reliably cancel the counterclockwise rotational (swinging) moment due to the biased gas lateral pressure in the space 11, thus reducing the sidewall of the top 33 of the side surface 15. Contact with the inner surface 10 can be reliably prevented, and inconvenient situations such as galling can be avoided.

In the above example, the piston ring 4 is provided on the side surface 9 of the piston 2 parallel to the piston ring 3 and inclined with respect to the upper surface 7 of the piston 2, but in the present invention, instead of this, as shown in FIG. Similarly to the oil scrubbing ring 5, the piston ring 4 may be arranged parallel to the upper surface 7 of the piston 2 and provided on the side surface 9 of the piston 2.

Furthermore, as shown in FIG. 3, the piston ring 4
, the distance between the piston rings 3 and 4 is from the anti-thrust side surface 15 of the piston 2 to the anti-thrust side surface 1
It is inclined to the piston ring 3 and extends to the outer circumferential surface of the piston 2 so that it gradually becomes longer toward the thrust-side side surface 16 facing the piston ring 5, in other words, so that the distance D2 is longer than the distance D1. The biased space 11, which is also an annular gas chamber, is arranged so that the pressure receiving area of the side surface 9 of the piston 2 that receives gas pressure is larger on the side surface 16 on the thrust side than on the side surface 15 on the anti-thrust side. form,
A gap 6 serving as a gas passage is formed by arranging opposing ends of the piston ring 3 which are disposed on the outer circumferential surface of the piston 2 substantially parallel to the upper surface 7 of the piston 2 that defines the engine combustion chamber 8 and spaced apart from each other. Alternatively, gas may be introduced into the biased space 11 through the gap 6. In this example, the both end abutting portions 12 of the piston ring 4 are designed to prevent the gas in the biased space 11 from leaking into the annular space defined between the piston ring 4 and the oil spool ring 5 through the both end abutting portions 12. The oil scrubber ring 5 is in close contact with or fitted into the piston ring 4, and the oil scrubber ring 5 further discharges the gas leaked into the annular space defined between the piston rings 4 and 5 through the abutting portions 12 at both ends of the piston ring 4 to the outside. It is designed to prevent it from escaping.

In the engine shown in FIG. 3 as well, the gas pressure generated by explosion in the engine combustion chamber 8 during the explosion stroke is introduced into the bias space 11 through the gap 6. The piston 2 receives the biased side pressure of the biased space 11, and during its reciprocating motion, it floats against the side wall inner surface 10, particularly against the side wall inner surface 10 on the side surface 16 on the thrust side. The piston 2, which is levitated against the inner surface of the side wall 10 by gas pressure, reciprocates with extremely low sliding frictional resistance, and the center 31 is offset from the center 32 of the piston 2 by a distance D3 toward the side surface 15, which is the anti-thrust side. Even in the engine of this example in which the piston pin 13 is attached to the piston 2, the center is aligned with the center 32 of the piston 2 and the piston pin 13 is attached to the piston 2. As a result of the rotation moment in the opposite clockwise direction being larger than the rotation moment in the clockwise direction, the rotation (swing) moment in the counterclockwise direction based on the biased side pressure of the gas in the space 11 is ensured. This can reliably prevent the top portion 33 from coming into contact with the inner surface 10 of the side wall, thereby avoiding inconvenient situations such as galling.

In the engine shown in FIG. 3, the gas passage 6 is formed by the abutting portions at both ends of the piston ring 3, but as shown in FIG. A recess 17 may be formed in the inner surface of the side wall 10, and the recess 17 may be used as a gas passage. Here, the deflection space 11 and the engine combustion chamber 8 are communicated with each other with the maximum opening degree at a crank angle of 10 degrees, and the deflection space 11 is completely closed at the top dead center.
The recess is formed so that the space 11 and the engine combustion chamber 8 are not communicated with each other or are communicated with each other with a small degree of opening, and the communication between the biased space 11 and the engine combustion chamber 8 is completely blocked at a crank angle of 20 degrees or more. By setting the number, shape, and position of the piston 17, the gas pressure from the engine combustion chamber 8 can be preferably utilized, and the piston 2 can be satisfactorily floated from the inner surface 10 of the side wall of the cylinder 1.

In the above example, the biased space 11 was formed by tilting either the piston rings 3 or 4, but as shown in FIG.
As shown in FIG. 2, the piston rings 3 and 4 are arranged parallel to the upper surface 7, respectively, and a gas chamber forming piece 21 that divides the annular space between the piston rings 3 and 4 into two semi-annular spaces 22 and 23 is provided. Two piston rings (one facing each other is not shown) are disposed between the piston rings 3 and 4, and the semi-annular space 23 is communicated with the engine combustion chamber 8 via the air gap 6. The annular space between them may be used as a biased space to form a gas chamber. Therefore, the engine shown in FIG. 5 has the same effect as the engine described above.

In the examples shown in FIGS. 3, 4, and 5, the gas passages are realized by the abutting portions or recesses of the piston rings, but the present invention is not limited to this. A recess or a through hole may be formed in at least one of the ring 3 and the cylinder 1 to serve as a gas passage. In the example in which a gas passage is provided, the gas pressure generated by the explosion in the engine combustion chamber 8 can be appropriately delayed and introduced into the deflection space 11, so that the rotation (oscillation) of the piston 2 can be further reduced, and the cylinder 1 inner side wall 1
0 can be further reduced.

[0025]

As described above, according to the engine of the present invention, the pressure receiving area of the piston side surface that receives gas pressure is larger than that of the anti-thrust side surface of the piston than on the thrust side surface opposite to this anti-thrust side surface. A piston that connects the connecting rod to the piston by forming an offset space in which gas pressure from the engine combustion chamber is guided between the inner surface of the side wall of the cylinder and the side surface of the piston facing the inner surface of the side wall so that the gas pressure is larger toward the inner surface of the side wall. Since the pin is eccentrically provided on the piston from the center of the piston toward the anti-thrust side, the sliding frictional resistance of the piston can be favorably reduced, and the abutment of the top of the piston against the inner surface of the cylinder side wall can be eliminated, as well as being extremely simple. It has a structure with excellent durability.

[Brief explanation of drawings]

FIG. 1 is a partially sectional side view of a preferred embodiment of the present invention.

FIG. 2 is a partially sectional side view of another preferred embodiment of the present invention.

FIG. 3 is a partially sectional side view of yet another preferred embodiment of the present invention.

FIG. 4 is a partially sectional side view of a fourth preferred embodiment of the present invention.

FIG. 5 is a partially sectional side view of a fifth preferred embodiment of the present invention.

[Explanation of symbols]

1 Cylinder 2 Piston 3 Piston ring 4 Piston ring D1 Distance D2 Distance 11 Biased space 13 Piston pin 14 Connecting rod 31 Center

Claims (12)

[Claims] Claim 1: The inner surface of the side wall of the cylinder is designed such that the pressure receiving area of the side surface of the piston that receives gas pressure is larger on the side surface on the thrust side opposite to the side surface on the anti-thrust side of the piston than on the side surface on the anti-thrust side of the piston. An eccentric space is formed between the piston and the side surface of the piston facing the inner surface of this side wall, into which gas pressure from the engine combustion chamber is guided, and the piston pin that connects the connecting rod to the piston is eccentric from the center of the piston toward the anti-thrust side. An engine equipped with a piston. 2. The piston ring is arranged such that the distance from the top surface of the piston that defines the engine combustion chamber gradually increases from the anti-thrust side of the piston to the thrust side opposite to the anti-thrust side. An engine in which a piston pin, which is provided on the side surface of the piston adjacent to the top surface of the piston and connects the connecting rod to the piston, is eccentrically provided on the piston from the center of the piston toward the anti-thrust side. 3. The pressure receiving area of the side surface of the piston that receives gas pressure from the engine combustion chamber is larger on the side surface on the thrust side opposite to the side surface on the anti-thrust side of the piston than on the side surface on the anti-thrust side of the piston. , an engine in which a piston ring is provided on the side surface of the piston, and a piston pin that connects a connecting rod to the piston is eccentric from the center of the piston toward the anti-thrust side. 4. The engine according to claim 2, wherein the piston ring is provided on a side surface of the piston at an angle with respect to an upper surface of the piston. 5. The engine according to claim 2, wherein a second piston ring is provided on a side surface of the piston adjacent to and parallel to the piston ring. 6. The engine according to claim 2, wherein a second piston ring is provided on a side surface of the piston, adjacent to the piston ring and parallel to the upper surface of the piston. 7. A first piston ring disposed between a side surface of the piston and an inner surface of a cylinder side wall facing the side surface of the piston and adjacent to an upper surface of the piston defining an engine combustion chamber; A gas passage communicating between an annular gas chamber defined between the ring and a second piston ring disposed adjacent to the engine combustion chamber is provided, and the distance between the first and second piston rings is such that the distance between the first and second piston rings is First and second piston rings are provided on the piston so as to be gradually longer from the anti-thrust side of the piston to the thrust side opposite to the anti-thrust side, and the connecting rod is connected to the piston. the piston pin,
An engine with a piston that is eccentric from the center of the piston toward the anti-thrust side. 8. The side surface of the piston and the side surface thereof are arranged so that the pressure receiving area of the side surface of the piston that receives gas pressure is larger on the side surface on the thrust side opposite to the side surface on the anti-thrust side of the piston than on the side surface on the anti-thrust side of the piston. A first piston ring disposed between the inner surface of the cylinder side wall facing the side surface of the piston and adjacent to the upper surface of the piston defining an engine combustion chamber; and a second piston ring disposed adjacent to the first piston ring. A gas chamber that communicates with the engine combustion chamber via a gas passage is formed between the second piston ring and the piston pin that connects the connecting rod to the piston is eccentrically moved from the center of the piston toward the anti-thrust side. The engine that is installed. 9. The first piston ring is disposed on the outer circumferential surface of the piston substantially parallel to the upper surface of the piston defining the engine combustion chamber, and the second piston ring
The engine according to claim 7 or 8, wherein the engine is arranged on the outer peripheral surface of the piston at an angle with respect to the first piston ring. Claim 10: The first and second piston rings are:
Claims 7 to 9, wherein the gas chamber forming piece is disposed on the outer circumferential surface of the piston substantially parallel to the upper surface of the piston that defines the engine combustion chamber, and is provided between the first and second piston rings. An engine according to any one of the clauses. 11. The engine according to claim 7, wherein the gas passage is formed by a gap between opposing and spaced apart abutting portions of both ends of the first piston ring. 12. The engine according to claim 7, wherein the gas passage is formed by a through hole or a recess provided in the piston, the first piston ring, or the cylinder.