JPS6030456A - Piston for internal-combustion engine - Google Patents

Abstract

PURPOSE:To make an oil sump part constituent member installable in a simple structure, by forming an oil sump part at the inner side of a piston body with a rack plate part whose outer peripheral edge engages the inner circumferential wall of the piston body, and a leg piece part engaging a piston pin locked to this rack plate part. CONSTITUTION:A piston body 1 is made up of casting into a cuplike form having a cylindrical side peripheral wall 2 and a top wall 3, while a pair of boss parts 4 having a piston hole 5 at the inner side of the side peripheral wall 2 is bulgingly formed. An oil sump part constituent member 10 extends in a direction at a right angle to a piston axis and engages an inner circumferential wall of the piston body 1 at an outer circumferential edge 11a, while it is provided with a rack plate part 11 partitioning an oil sum part A at the side of the top wall part 3 and a pair of leg piece parts 12 being bent at the opposite side to the top wall part 3 from part of the outer peripheral edge of the rack plate part 11 as one body. Likewise, at the leg piece part, there are provided with a through hole 13 in which a piston pin is pierced and an annular projection strip 14 being projectingly formed in its peripheral edge part.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a piston for an internal combustion engine, and particularly to a piston used in an internal combustion engine equipped with an oil injection type piston cooling device.

In internal combustion engines, there has been a conventional oil injection type piston cooling device in which engine lubricating oil is injected from the crankshaft towards the inner space of a piston with a cup-shaped structure, and the lubricating oil cools the piston, especially the top wall. As a piston that is well known and has been improved so that the top wall can be effectively cooled by the oil injection type piston cooling device as described above, lubricating oil is injected near the top wall toward the top wall. A piston having an oil reservoir part that receives
'O-192'01), Jitsugan Showa 42-1 '0185
No. 2 (Jitko No. 45-32981), Jitsugan No. 56-42
Various proposals have been made in No. 967 (Utility Model Application Publication No. 57-156'052) or its patent application.

The oil reservoir described above can be formed near the top wall of the piston by casting or welding two piston components together without requiring any special components, but in this case, there are problems with ease of manufacture and product quality. The problem is that it lacks quality and increases production costs. For this purpose, a piston with an oil reservoir defined on the top wall by a shelf plate member provided in the inner space of the piston and fixedly connected to the piston with a screw, or a spring provided in the inner space of the piston with an oil reservoir defined on the top wall. The above-mentioned utility model registration application for a piston in which an oil reservoir is defined on the top wall by a shelf plate member fixedly connected to the piston by force is filed in J:
has already been proposed.

However, in a piston to which a shelf board member is attached by screws, there is a risk that the shelf board member may fall off due to loosening of the screws, and in a piston to which a shelf board member is attached by the spring force of a spring, However, there are disadvantages in that the mounting structure is relatively complicated and the mounting reliability is poor.

An object of the present invention is to provide a piston for internal combustion relief with a simple structure in which a shelf plate member, that is, an oil sump component member is reliably attached, and there is no risk that the oil sump component member will fall off. There is.

According to the present invention, this object includes a cup-shaped piston body having a top wall at one end, and an oil reservoir component provided in an inner space of the piston body, and the oil reservoir component includes: a shelf part that engages with the inner circumferential wall of the piston body at an outer peripheral edge and defines an oil reservoir on the side of the top wall part; and a shelf part that is fixedly connected to the shelf part and corresponds to the piston pin hole of the piston body. and a leg portion that engages with at least one of the piston pins inserted into the piston pin hole and is supported by the piston body, and at least one of the piston body and the oil reservoir component is connected to the oil reservoir portion. This is achieved by a piston for an internal combustion engine having an oil supply passage for supplying oil to the oil reservoir and an oil discharge passage for discharging oil from the oil reservoir.

As mentioned above, in the internal combustion engine piston according to the present invention,
Since the oil sump component is mounted by effectively utilizing the piston pin hole that the piston originally has or the piston pin inserted into the piston pin hole, the structure of the oil sump component can be simplified and ensured. Attach to the piston body.

The invention will now be described in detail by way of example embodiments with reference to the accompanying drawings.

1 to 4 show one embodiment of a piston for an internal combustion engine according to the present invention. The piston for an internal combustion engine according to the present invention is composed of a piston body 1 and an oil reservoir forming member 10.

The piston body 1 is formed by casting into a cup shape having a cylindrical side circumferential wall 2 and a top wall portion 3 provided at one end of the side circumferential wall so as to close the one end.

A pair of boss portions 4 are formed bulging inside the side peripheral wall 2, and piston pin holes 5 are provided in the pair of boss portions 4 on the same axis. A piston pin 6 is inserted into the piston pin hole 5 to connect the piston to a connecting rod (not shown).

The oil reservoir component 10 extends along a virtual plane orthogonal to the piston axis, and is engaged with the inner circumferential wall of the piston body 1 at the outer peripheral edge 11a, defining an oil reservoir portion on the side of the top wall portion 3. The shelf board part 11 and the top wall part 3 from a part of the outer peripheral edge of the shelf board part 11
A pair of leg portions 12 are formed integrally with each other and are bent on opposite sides. As clearly shown in FIG. 4, the leg portion 12 has a through hole 1 through which the piston pin 6 passes.
3 and an annular protrusion 14 protruding from the periphery of the through hole.
and is provided. The annular protrusion 14 is connected to the piston body 3
The piston pin hole 5 is fitted into an enlarged diameter portion 7 provided around the inner open end of the piston pin hole 5 .

Incidentally, the oil reservoir forming portion tv 1 'O may be formed by pressing a metal plate.

The oil reservoir component 10 has an annular protrusion 14 connected to the piston body 1.
The piston pin 6 is fitted into the enlarged diameter portion 7 of the piston body 1 and is supported by the piston body 1 by passing through the through hole 13, so that the outer peripheral edge 12 of the trench shelf portion 11 is attached to the piston body 1 over its entire circumference. By being joined to the inner circumferential wall of the piston body 1, it is arranged in a stable position within the inner space of the piston body 1, and defines an oil reservoir A as described above on the top wall portion 3 side of the shelf portion 11.

, As shown in FIG. 3, the shelf section 11 has
A lubricating oil supply hole 15 that introduces lubricating oil injected toward the top wall portion 3 from a fuel injection nozzle N (see Fig. 1) provided in a cylinder block of an internal combustion engine into an oil sump portion A, and an oil sump portion. A lubricating oil discharge hole 16 for discharging the lubricating oil introduced into the oil reservoir A to the outside of the oil reservoir portion A is provided at a distance from each other.

Note that the lubricating oil supply hole 15 and the lubricating oil discharge hole 16 may be provided in the piston body.

When the piston moves from the top dead center position to the bottom dead center position, that is, during the expansion stroke, the lubricating oil accumulated on the shelf plate part 11 jumps toward the top wall part 3 due to inertia, and the lubricating oil accumulates on the top wall part 11. The top wall portion 3 is cooled by adhering to the back surface of the top wall portion 3. In this case, the shape of the back side of the top wall 3 is as shown in FIGS. As shown in FIG. 2, it is preferable that the piston has a conical shape or a partially spherical shape with the central axis of the piston as its central axis.

FIG. 5 shows another embodiment of the piston for an internal combustion engine according to the present invention. In addition, in Figure 5, Figures 1 to 4
Parts corresponding to - are indicated by the same reference numerals as those shown in FIGS. 1 to 4. In this embodiment, the leg portion 12 of the oil reservoir component 10 is fitted into the outer peripheral portion of the piston pin 6 via the annular rubber-like elastic member 17, and the piston body is 1 is supported.

Therefore, also in the embodiment shown in FIG. Define the oil sump part A.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited to the above-mentioned embodiments, and various other embodiments are possible within the scope of the present invention. This will be obvious to those skilled in the art.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a piston for an internal combustion engine according to the present invention, FIG. 2 is a sectional view taken along the line - H in FIG. 1, and FIG. A bottom view of the piston, FIG. 4 is a partial vertical sectional view showing an enlarged main part of the piston shown in FIGS. 1 to 3, and FIG. 5 is a diagram showing another piston for an internal combustion engine according to the present invention. FIG. 2 is a cross-sectional view corresponding to the cross-sectional view taken along the line ■-■ in FIG. 1, showing one embodiment. DESCRIPTION OF SYMBOLS 1... Piston main body, 2... Side peripheral wall, 3... Top wall part. 4... Boss part, 5... Piston pin hole, 6... Piston pin, 7... Expanded diameter part, 10... Oil reservoir component, 11... Shelf board part, 12...・Leg piece, 13...
Through hole, 14... Annular protrusion, 15... Lubricating oil supply hole, 16... Lubricating oil discharge hole, 17... Rubber-like elastic member, A... Oil reservoir portion. N...Lubricating oil injection nozzle patent applicant Toyota Motor Corporation representative Patent attorney Masaki Akashi

Claims (1)

[Claims] It has a cup-shaped piston body having a top wall portion at one end, and an oil reservoir component provided in an inner space of the piston body, and the oil reservoir component has an outer peripheral edge that is attached to the inner circumferential wall of the piston body. a shelf plate portion that engages with the top wall portion and defines an oil reservoir on the side of the top wall portion; a piston pin hole that is fixedly connected to the shelf plate portion and that is inserted into the piston pin hole of the piston body; a leg portion that engages with at least one side and is supported by the piston body, and at least one of the piston body and the oil reservoir component includes an oil supply passage that supplies oil to the oil reservoir portion; A piston for an internal combustion engine that has an oil discharge passage that discharges oil from an oil reservoir.