JPS5865952A - Piston for internal combustion engine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a piston for an internal combustion engine.

The conventional piston used in internal combustion engines is piston spatula I.
It has a piston hole, and a skirt extending around the entire circumference of the piston. In this case, the skirt does not perform the sole function of sealing the gas, but the piston ring attached to the piston acts to seal the gas. On the contrary, the skirt has the disadvantage of transmitting the transverse stresses exerted on the piston by the connecting rod during the reciprocating movement of the piston to the associated cylinder or liner.

Although the weight of such pistons as mentioned above has certainly been reduced in recent years by the use of aluminum or aluminum alloys, such pistons are still quite heavy.
The area of the skirt in contact with the cylinder or liner creates significant frictional forces that must be overcome by the internal combustion engine and thus reduce its power output. A variety of proposals have been made with the aim of reducing such skirt range, however these proposals have generally not met with commercial success due to lubrication problems and skirt stiffness.

Therefore, in order to avoid the drawbacks that conventional pistons have, in the configuration of the first invention, in a piston for an internal combustion engine having a piston head P and a piston pin hole, the piston pin hole axis and the piston at least two bearing surfaces are provided on each side of a plane containing the axis, one bearing surface or group of bearing surfaces being located at the lower end of the piston head and being separated by an axially and circumferentially extending gap; axially spaced apart from one or more bearing surfaces of the piston, the at least two bearing surfaces being located proximate a plane that includes the piston axis and a line orthogonal to the piston pin hole axis; extends only partially around the

In a still second aspect of the invention, in a piston for an internal combustion engine, the piston head has a sharpening land, on both sides of a plane containing the piston pin hole axis and the Toviston axis, respectively, with respect to the piston pin hole axis. Two bearing surfaces or groups of bearing surfaces are provided extending only partially around the piston on either side of a plane containing the perpendicular line and the piston axis, one of the bearing surfaces or groups of bearing surfaces; is supported by piston run I and the other support surface or group of support surfaces is piston run 1?
spaced from and held on one or more supports;
ing.

The invention will now be described in detail with reference to the drawings.

As shown in FIGS. 1, 2 and 4, the first piston 1, 1! A piston pin hole (see FIG. 2) extending through the piston 1 is formed with a piston head F''2 surrounded by a piston land 3 for receiving a stone ring (not shown). It has one piston pin hole 6.

Furthermore, the piston 1 has two supporting surfaces 4 and 5 on both sides of a plane including the piston pin hole axis and the piston axis, and both supporting surfaces 4 and 5 are separated by a gap extending in the axial direction and the circumferential direction. Separated. Giston Hetsu 1 Ki 2
The upper support surface 4 located at the lower end of the piston land 3 extends downwardly from the piston land 3 (see FIG. 2), while the other lower support surface 5 extends from the paired support 7 ( 10A and 10B)). The lower support surface 5 is therefore only supported in a cantilevered manner by the support 7 extending from the piston body 6. The supporting surfaces 4 and 5 are
They are arranged symmetrically near a plane (i.e., the cross section in FIG. 2) that includes a line orthogonal to the piston pin hole axis and the piston pin axis, and extend only partially on the circumferential surface of the piston 1. do not have. For example, the bearing surfaces 4, 5 extend over 45° on either side of said plane.

In another embodiment (not shown), the support 7 may carry not only the lower bearing surface 5 but also the upper bearing surface 4.

The bearing surfaces 4, 5 have approximately the shape of cylindrical segments, the lower edge of the upper bearing surface 4 and the two circumferentially extending edges of the lower bearing surface 50 being aligned with the piston axis. They are respectively located on planes perpendicular to each other, and chamfered portions 8 are provided on their edges.

The advantageous shape of the lower support surface 5 and the associated chamfer 8 is shown enlarged in FIG. Support 5
is curved in the plane containing the piston 1llt+ line and has a maximum radial depth of, for example, 0.02 mm (see X in FIG. 6). Chamfered portion 8 is piston IIQ
(It is flat in the plane including +
1 and inclined at an angle of 15°, or the length of the chamfered portion 8 is one gate and the depth in the radial direction (see X in Fig. 6) is O, (
It is 14ran. However, it is also possible for the double-sided bevel 8 to be curved and for the bevel 8 and the support 5 to have another corresponding shape. It is also possible for the chamfer 8 on the lower edge of the side support surface 4 to have dimensions equal to the advantageous shape described above.

In use, the lateral stress of the piston is applied to the supporting surfaces 4, 5.
is transmitted to the related cylinder or lychee 20 by. The supply of lubricant to the bearing surfaces 4, 5 during the reciprocating movement of the girdles is ensured by the fact that the chamfer 8 forms a passage leading to the associated bearing surface and reducing its dimensions. As a result, the lubricant reaches the support surfaces 4, 5 under pressure, thus ensuring sufficient hydrodynamic lubrication. With the lower bearing surface 5 being curved as shown in FIG. 6, the curvature of this bearing surface 5 also serves to ensure sufficient lubrication.

The reduction in the dimensions of the bearing surfaces 4, 5 and the windows thereby formed in the skirt reduce the weight of the piston, which is responsible for the reduction in power. Furthermore, the frictional losses due to the contact between the piston and the corresponding cylinder or liner are small due to the extent of the bearing surfaces 4, 5 compared to conventional pistons with continuous scars 1. be reduced.

Since the bearing surfaces 4,5 are sufficiently lubricated, the gap between the bearing surfaces 4,5 can always be kept at a maximum without having to increase the bearing surface area in the central part of the bearing surfaces 4.5. Furthermore, based on the dimensions of the support surfaces 4, 5, the production cost of the piston is reduced and the performance of the engine equipped with this piston is also improved.

The piston of the second embodiment shown in FIGS. 3 and 5 is substantially the same as the piston of the first embodiment shown in FIGS. 1, 2, and 4; Parts that are common to the piston are given the same reference numerals with the addition of an a. ? Y.Detailed explanation of the common parts will be omitted here. In the second embodiment shown in FIGS. 3 and 5, the piston spatula 1
Instead of the bearing surfaces 5 which are spaced apart from the bearing surfaces 2, there are in each case pairs of substantially rectangular sector-shaped bearing surfaces 9 spaced apart in the circumferential direction. Furthermore, instead of one piston boss 6 being provided, a pair of piston bosses 6a are provided, and each support surface 9 around each support surface is supported by a support 7a (FIG. 10A and FIG. 1.01. 3) through the associated piston boss 6 (which may have the shape shown in Figure 3)
Combined with a"1. I'm here. The support 9 has a chamfered portion similar to the support 5, and may have a cross-sectional dimension as described in section 2 with reference to FIG. Support surface 9
is axially aligned with the upper bearing surface.

A metal ring 10, shown in broken lines in FIGS. 3 and 5, connects the four sector-shaped support surfaces 9 to one another and serves to control the extent of the support surfaces 9 in the radial direction.

The piston according to the second embodiment operates in substantially the same manner as the piston according to the first embodiment and has substantially the same advantages. However, because the sector-shaped support surface 9 has a smaller surface area than the support surface 5, both weight and friction are further advantageously reduced.

The second piston 11 shown in FIGS. 7-9
has a piston spatula l-''12 surrounded by a piston land 13 with a receptacle ring groove for receiving a piston ring (not shown). One piston boss 16 is provided.

This piston 11 has a support 14 above the lower end of the piston head and a piston spatula 1 on both sides of a plane including the piston axis and the piston pin hole axis. A lower support surface 15 is provided spaced apart from the lower end. Both supporting surfaces 14.15 are connected to each other on each side by snow J-1 portions 14a (see FIGS. 7 and 8).
(see figure). The lower support surface 15 is connected to the piston boss 16 via a support 17 (see FIG. 8), while the upper support surface 14 is connected to the piston land 13. Therefore, on each side of the plane, there is a piston run +F
One member is formed each having an upper edge coupled to the piston boss 13 and a lower edge coupled to the piston boss 16. The side edges 28 of this composite part 4, which extend in the 1111 direction, form respective gaps that open into circumferential cavities S extending between the composite part and the other parts of the piston. .

The lower support 15 in this embodiment and FIGS.
The lower support surface 5 or support surface 9 in the embodiment shown in FIG. 6 corresponds to each support 7, 7a.

17, these supports 7.7a, 17 are subjected to a large load. Therefore, in order to avoid the possibility of support failure, the support is flanted, for example, so that it has a T-shaped cross section (see Figure 10A) or a ten-shaped cross section (see Figure 10B). You can leave it there.

The bearing surface 14.15 and the skirt portion 14a are arranged symmetrically near a plane containing the piston axis and a line perpendicular to the piston pin hole axis (ie the cross-section of FIG. 8). The lower support surface 15 is configured to be longer in the circumferential direction than the skirt portion 14a and the upper support surface 14, which have equal lengths in the circumferential direction.

For example, the lower support 15 extends in an arc shape over 90°, and both side edges of the support surface 15 are connected to the other support surface 15.
(see FIG. 9).

In use, the piston slides along, for example, a diesel engine, an odd cycle engine or a two-cycle engine. Lateral stresses are transferred to the bearing surface 14.15. Support 15
A chamfer 18 on the lower edge of the support 15 ensures that lubricant flows into the support 15. This chamfer 18 may have dimensions and structure as described above with reference to FIG.

The stones shown in Figures 7 to 9 include Figures 1 to 9.
1-! shown in FIG. ``Similar to stone, it has the advantages of being lightweight, low friction, and inexpensive. The support body 17 has a side edge portion and a support body 11? The bearing surfaces 14, 1.5 are held in a fixed position without the need for any separate connecting members between the support surfaces 14 and 1.5.

It is also possible to provide an embodiment in which three or more supporting surfaces are provided on each side of the plane containing the piston axis and the piston pin hole axis. For example, as shown in FIGS. 3 and 5, it is possible to provide three or more support surfaces on each side in a radial configuration.

[Brief explanation of drawings]

Fig. 1 is a side view showing a first embodiment of the first piston, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is a second embodiment of the first piston. A side view showing an example; FIG. 4 is a bottom view of the piston shown in FIGS. 1 and 2; FIG. 5 is a bottom view of the piston shown in FIG. 3;
Figure 6 is a sectional view taken along the line ■-■ in Figure 1 or Figure 3;
Fig. 7 is a side view of the second piston, Fig. 8 is a sectional view taken along the line ■-■ in Fig. 7, and Fig. 9 is a side view of the second piston.
10A and 10B are cross-sectional views taken along line χ-X in FIG. 8. 1.11... Piston, 2.2a, 12... Piston head, 3.3a, 13... Piston land, 4.5
, 9, 14. 15...Support surface, 6, 6a. 16... Piston boss, 7, 7a, 17... Support body, 8.18... Chamfered portion, 10... Metal ring, 2
0...liner, 28...side edge, X...maximum radial depth of support surface curvature, y...radial depth of chamfer, S...imprint of cavity drawing (contents) ) 'J! Ili? l! j58-65952(6)FtG,
/. Hand, continuation amendment (method) November 17, 1980 Dear Commissioner of the Japan Patent Office 1, Indication of fact r+- 1988 Patent Application No. 131353
Name of invention No. 2 Piston for internal combustion engine 3 Patent related to the case involving the person making amendments Name of applicant: NI plc 4, agent 5, date of amendment order: October 26, 1980 (dispatch) 6 Correction target 310-

Claims (1)

[Claims] 1. A piston for an internal combustion engine, comprising:
and a piston pin hole,
At least two support surfaces are provided on each side of a plane including the piston pin hole axis and the piston axis,
one bearing surface or group of bearing surfaces is located at the lower end of the piston head and is axially separated from the remaining bearing surface or surfaces by an axially and circumferentially extending gap; an internal combustion engine, characterized in that the two bearing surfaces are located near a plane containing the piston axis and a line perpendicular to the piston pin bore axis and extend only partially around the piston; Engine piston. 2. A piston according to claim 1, wherein each bearing surface has the general shape of a cylindrical segment. 3. A bearing surface at the lower end of the piston head 1 is provided one on each side, and the remaining bearing surfaces are also provided one each and are separated from the bearing surfaces at the lower end of the piston head by a gap. The piston according to the range No. 1 above. 4. On each side there is one supporting surface for the lower end of the piston head, and two remaining supporting surfaces are provided, the two supporting surfaces being separated in the circumferential direction but aligned in the axial direction. A piston according to claim 1. 5. The piston according to claim 4, wherein the remaining two supporting surfaces are arranged symmetrically on both sides of a plane containing the piston axis and a line perpendicular to the piston pin hole axis. 6. The remaining two supporting surfaces on one side of a plane containing the piston axis and the piston pin hole axis and the remaining two supporting surfaces on the other side of the plane extend around the piston. 5. The pistons according to claim 4, wherein the pistons are connected to each other by metal joints. 7. the remaining bearing surface has two circumferentially extending edges generally parallel to each other, and at least one of the edges is provided with a lubricant on the remaining bearing surface during reciprocating movement of the piston. The piston according to claim 1, further comprising a chamfered portion for guiding the piston. 8. The piston according to claim 7, wherein the chamfered portion is flat or curved in a plane including the piston axis. 9. The remaining supporting surfaces are barrel-shaped and curved in a plane containing the piston axis in order to guide lubricant to the remaining supporting surfaces during the reciprocating movement of the screw. The piston according to item 1. 10 In a piston for an internal combustion engine having a piston spatula 12 and a piston land, a piston pin hole axis line is provided on both sides of a plane containing the piston pin hole axis line and the piston axis line. two bearing surfaces or groups of bearing surfaces are provided extending only partially around the piston on either side of a plane containing a line perpendicular to the cutting stone axis, one bearing surface or group of bearing surfaces; is supported by piston run P,
Piston for an internal combustion engine, characterized in that the other bearing surface or group of bearing surfaces is spaced apart from the piston run IS and is held on one or more supports. 11 The main bearing surfaces connected to the piston land by screws 1 and 1 are provided on each side and extend downwardly from the piston land, and the bearing surfaces held by the support or supports are also 1 Claim No. 1 provided for each
The piston described in item 0. 12. The support surface supported on the piston run 1 and the support connected to the support are connected at one end to the piston run 13, and the number or plurality of supports a plurality of circumferentially spaced, generally axially extending edges joined together by a skirt portion to form a generally partially cylindrical member held in place; 11. The piston according to claim 10, wherein the piston has edges defining respective gaps leading into a circumferentially extending cavity between the member and the rest of the piston. piston. 13. A piston according to claim 10, in which one or more piston bosses delimit the piston pin bore, and the support is connected at one end to the piston bosses. 14. Claim 1 in which two supports are provided
The piston described in item 3. 15. The piston according to claim 10, wherein the support has a T-shaped or ten-shaped cross section and is cast integrally with the rest of the piston.