JP2005256801A - Piston - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piston which enables a reduction in oil consumption. <P>SOLUTION: The piston is provided with a spring 102 and a pin-like member 103. The spring is arranged at part of a top ring groove 7 as a means of energization. Then the pin shape member is engaged with an abutment part 21u of a top ring 21, and is brought into contact with a wall surface 2a by being energized by the spring 102. The top ring groove 7 has a hole part 101 extending in the radial direction, and the spring 102 and at least one part of the pin-like member 103 are engaged with the hole part 101. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a piston, and more particularly to a piston used in an internal combustion engine.

Conventionally, pistons are disclosed in, for example, JP-A-57-193944 (Patent Document 1), JP-A-4-73654 (Patent Document 2), and JP-A-58-56139 (Patent Document 3). Yes.
JP-A-57-193944 Japanese Utility Model Publication No. 4-73654 Japanese Utility Model Publication No. 58-56139

  In any of the pistons described in the above-mentioned documents, a pin for preventing rotation of the piston ring is fixedly attached to the bottom of the ring groove into which the piston ring is fitted. The pin fits into the joint portion of the piston ring.

  However, in any structure, the tip of the pin is located on the inner diameter side of the land portion of the piston, and the gap of the joint portion can be reduced as compared with the joint structure of the piston ring of the piston without the conventional rotation stopper. Although it is possible, since there is a gap between the pin and the cylinder wall surface (inner peripheral surface), the joint gap cannot be completely closed in the piston intake process. Accordingly, there has been a problem that the inflow of oil into the combustion chamber (oil rise) cannot be completely prevented and the oil consumption cannot be significantly reduced.

  Accordingly, the present invention has been made to solve the above-described problems, and an object thereof is to provide a piston capable of reducing oil consumption.

  The piston according to the present invention slides in a cylinder of an internal combustion engine, seals the combustion pressure, generates a driving force, and oil for reducing sliding resistance during sliding is contained in the combustion chamber. It is a piston having a ring groove into which a piston ring that suppresses entry is fitted. The piston further includes urging means disposed in a part of the ring groove, and a pin-like member that fits into the joint portion of the piston ring and abuts against the cylinder wall surface by being urged by the urging means.

  In the piston configured as described above, the pin is urged by the urging means so as to contact the cylinder wall, and slides on the cylinder wall surface together with the piston and the piston ring. Due to the movement of the pin, the outer peripheral portion of the piston ring is inclined upward during the intake process, so that the joint portion of the piston ring comes into contact with the pin and the joint gap is completely closed. Therefore, the oil that has entered the combustion chamber through the conventional gap and burned and burned can be greatly reduced. Further, it has a function of preventing rotation of the piston ring.

  More preferably, the ring groove has a hole extending along the radial direction of the cylindrical shape constituting the piston, and at least a part of the urging means and the pin-shaped member are fitted in the hole.

  In the piston configured as described above, since the urging means and the pin-shaped member are fitted in the hole portion, the urging means and the pin-shaped portion can be positioned more reliably.

  More preferably, the piston includes a plurality of ring grooves and a pin-like member provided in each of the plurality of ring grooves. On the outer periphery of the piston, a certain pin-shaped member is provided at a position different from that of another pin-shaped member. In this case, it is possible to prevent the joint portion from being matched, and thus it is possible to more reliably prevent the oil from rising.

  More preferably, the shape of the joint portion of the piston ring is a concave shape capable of receiving a pin-like member. In this case, the contact between the pin-shaped member and the joint portion can be made more complete.

  According to this invention, a piston capable of reducing oil consumption can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. In the following embodiments, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
FIG. 1 is a cross-sectional view of a piston according to Embodiment 1 of the present invention. FIG. 2 is an enlarged cross-sectional view of a portion surrounded by II in FIG. Referring to FIGS. 1 and 2, piston 1 is enclosed in a region surrounded by cylinder wall 2. The piston 1 has a head portion 11 facing the combustion chamber 6 and a skirt portion 4 facing the head portion 11 and facing the wall surface 2 a that is the surface of the cylinder wall 2. Further, the piston 1 is provided with a boss portion 10 for connection to a connecting rod (not shown).

  A gap portion 5 is provided between the cylinder wall 2 and the skirt portion 4 to ensure a predetermined clearance. The piston 1 is provided with a top ring groove 7, a second ring groove 8 and an oil ring groove 9 as piston ring grooves so as to face the cylinder wall 2. A top ring 21, a second ring 121, and an oil ring 221 are fitted in each groove. The top ring groove 7, the second ring groove 8 and the oil ring groove 9 are each annular, and the top ring 21, the second ring 121 and the oil ring 221 are fitted together so as to fit into the respective annular grooves.

  Referring to FIG. 2, the top ring 21 faces the cylinder wall 2 and comes into contact with an oil film 100 made of oil and formed on the wall surface 2 a of the cylinder wall 2. The cross section of the top ring groove 7 has a substantially rectangular shape, and is defined by three surfaces: an upper surface 7a, a side surface 7b, and a bottom surface 7c. The top ring 21 has an upper surface 31 and an inner peripheral surface 21 i so as to be continuous with the upper surface 31. Of the top ring 21, the sliding surface 21 f facing the wall surface 2 a has a barrel shape (round shape) and has a shape capable of reducing friction.

  3 is a cross-sectional view taken along line III-III in FIG. Referring to FIG. 3, the piston 1 slides in the cylinder of the internal combustion engine, seals the combustion pressure, generates a driving force, and oil for reducing the sliding resistance when sliding is burned. A piston having a top ring groove 7 into which a piston ring that suppresses entry into the chamber is fitted. The piston 1 includes a spring 102 as a biasing means disposed in a part of the top ring groove 7, and a piston ring. And a pin-like member 103 that fits into the joint portion 21u of the top ring 21 and abuts against the wall surface 2a by being biased by the spring 102.

  The top ring groove 7 has a hole 101 that extends along the radial direction of the cylindrical shape that constitutes the piston 1, and at least a part of the spring 102 and the pin-like member 103 fits into the hole 101.

  A portion of the piston 1 having a substantially circular cross section is cut out to form a hole 101 extending in the radial direction. A spring 102 is disposed in the hole 101. The spring 102 may be replaced with an elastic body such as a leaf spring. Further, it can be replaced with an elastic member such as rubber or resin. A part of the pin-shaped member 103 is fitted in the hole 101. The pin-like member 103 can slide and move in the radial direction within the hole 101.

  The pin-like member 103 is pressed against the wall surface 2 a by being biased by the spring 102. Since the pin-shaped member 103 is fitted in the joint portion 21u, the pin-shaped member 103 has an effect of preventing the top ring 21 from rotating. Furthermore, since the pin-like member 103 seals the joint portion 21u, it has an effect of preventing the inflow of oil. The top ring 21 has a circular shape with a part cut away, and is arranged to face the wall surface 2a with a slight gap.

  FIG. 4 is a side view of the piston as seen from the direction indicated by IV in FIG. Referring to FIG. 4, the top ring 21 has a joint portion 21 u, and the shape of the joint portion 21 u is a concave shape capable of receiving a pin-shaped member 103 as a rotation stopper pin. A gap portion 21g is provided at the bottom of the abutment portion 21u so that a liquid or gas can flow from the upper surface side to the lower surface side of the top ring 21. In this embodiment, the side shape of the non-rotating pin-like member 103 is circular, but the present invention is not limited to this, and a non-rotating pin-like member 103 having a polygonal or elliptical shape may be provided. Good. In these cases, it is preferable that the shape of the abutment portion 21u also matches the shape of the pin-shaped member 103.

  Next, the operation of the piston shown in FIGS. 1 to 4 will be described. 5 and 6 are partial side views of the piston shown for explaining the operation of the piston. With reference to FIG. 5, in the expansion step, that is, the step of lowering the piston, the top ring 21 is pressed toward the bottom surface 7 c of the top ring groove 7 due to an increase in pressure due to expansion. The piston descends in the direction indicated by arrow 1d. As a result, a gap is generated between the abutting portion 21u and the pin-shaped member 103, and liquid and gas flow in the direction indicated by the arrow 151. That is, gas and oil flow in the direction indicated by the arrow 151. As a result, the oil moves from the combustion chamber to the outside of the combustion chamber.

  Referring to FIG. 6, the piston moves down in the direction indicated by arrow 1d also in the intake process, but the pressure in the combustion chamber does not increase abruptly in the intake process. Therefore, as shown in FIG. It is not pressed against the bottom surface 7c side. As a result, the joint portion 21u and the pin-shaped member 103 are in close contact with each other, and the pin-shaped member 103 seals the gap portion 21g. Thus, in the intake process, oil can be prevented from being sucked from the bottom surface 7c side to the top surface 7a side of the top ring groove 7, and oil can be prevented from being sucked into the combustion chamber. As a result, oil consumption can be suppressed.

  In the piston according to the present invention described above, the oil in the combustion chamber is discharged as shown in FIG. 5 in the expansion process, and the oil flows into the combustion chamber in the intake process as shown in FIG. Can be prevented. As a result, a piston capable of reducing oil consumption can be provided.

(Embodiment 2)
FIG. 7 is a sectional view of a piston according to the second embodiment of the present invention. Referring to FIG. 7, in piston 1 according to the second embodiment of the present invention, pin-shaped member 203 is provided so as to prevent the second ring joint portion. The pin-like member 203 is urged by a spring 202 as urging means.

  The spring 202 is accommodated in the hole 201. That is, the piston 1 includes pin-like members 103 and 203 provided in the top ring groove 7 and the second ring groove 8 respectively. On the outer periphery of the piston 1, one pin-like member 103 is provided at a position different from another pin-like member 203.

  In the piston 1 configured in this way, the pin-like members 103 and 203 are provided at different positions, so that the inflow of oil can be prevented more reliably. As a result, a piston capable of further suppressing oil consumption can be provided.

  Although the embodiment of the present invention has been described above, the embodiment shown here can be variously modified. First, in the present invention, a piston having three ring grooves is shown. However, the present invention is not limited to this, and the present invention may be applied to a piston having two ring grooves. Various materials such as aluminum and iron can be used as the material constituting the piston. Furthermore, the present invention can be applied to both gasoline engines and diesel engines.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention can be used in the field of pistons for internal combustion engines.

It is sectional drawing of the piston according to Embodiment 1 of this invention. It is sectional drawing which expands and shows the part enclosed by II in FIG. It is sectional drawing along the III-III line in FIG. FIG. 4 is a side view of the piston as seen from the direction indicated by arrow IV in FIG. 3. It is a partial side view of the piston shown in order to demonstrate operation | movement of a piston. It is a partial side view of the piston shown in order to demonstrate operation | movement of a piston. It is sectional drawing of the piston according to Embodiment 2 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Piston, 2 Cylinder wall, 2a Wall surface, 4 Skirt part, 5 Clearance part, 6 Combustion chamber, 7 Top ring groove, 8 Second ring groove, 9 Oil ring groove, 10 Boss part, 11 Head part, 21 Top ring, 121 Second ring, 221 oil ring, 21f sliding surface, 101, 201 hole, 102, 202 spring, 103, 203 pin-shaped member.

Claims (4)

A piston ring that slides in a cylinder of an internal combustion engine, generates a driving force by sealing the combustion pressure, and suppresses oil from entering the combustion chamber to reduce sliding resistance during sliding. A piston having a ring groove to be fitted,
Biasing means disposed in a portion of the ring groove;
A piston further comprising: a pin-like member that fits into a joint portion of the piston ring and abuts against a cylinder wall surface by being urged by the urging means.   2. The ring groove according to claim 1, wherein the ring groove includes a hole portion extending along a cylindrical radial direction constituting the piston, and at least a part of the urging means and the pin-shaped member are fitted in the hole portion. Piston.   A plurality of the ring grooves and pin-shaped members provided in each of the plurality of ring grooves, and on the outer periphery of the piston, a certain pin-shaped member is provided at a position different from another pin-shaped member; The piston according to claim 1 or 2.   The piston according to any one of claims 1 to 3, wherein a shape of the joint portion of the piston ring is a concave shape capable of receiving the pin-shaped member.

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