JP2000310106A - Lubricating structure for piston and connecting rod and piston for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reuse oil lubricating a piston and a connecting rod for lubrication of the piston and the connecting rod. SOLUTION: By forming a pin boss 2 provided with a pin hole 3 on a piston 1, branching a piston side tip part 5 of a connecting rod 4 and arranging the parts 5 on both sides of the pin boss 2, forming pin holes 6 at the piston side tip parts 5, inserting a piston pin 7 into the piston hole 3 of the piston 1 and the pin holes 6 of the piston side tip parts 5 and forming a recessed part 9 for oil reservoir in a part which is a fork part 8 of the branched piston side tip parts 5 and is located on lower sides of the piston boss 2 and the piston pin 7, oil lubricating the piston 1 and the connecting rod 4 can be prevented from passing the fork part 8 and falling. Oil within the recessed part 9 for oil reservoir is sprung up at the time of raising the piston 1 and is used again for lubrication of the piston 1 and the connecting rod 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lubrication structure for a piston and a connecting rod, and a piston for an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, a pin boss having a pin hole is formed on a piston, a piston-side end of a connecting rod is branched and arranged on both sides of the pin boss, and a pin hole is formed at the piston-side end to form a piston pin. A lubrication structure for a piston and a connecting rod inserted into a pin hole of a piston and a pin hole at an end on the piston side is known.

[0003]

However, in the above-described known lubricating structure of the piston and the connecting rod, the forked portion of the branched piston side end portion is located below the pin boss and the piston pin. Does not have an oil reservoir recess. Therefore, the oil that has lubricated the piston and the connecting rod drops through the fork and falls, and therefore, the oil that has lubricated the piston and the connecting rod cannot be used again for lubricating the piston and the connecting rod.

Further, a pin boss having a pin hole is formed in the piston, a pin hole is formed in the piston-side end of the connecting rod, a hollow piston pin is inserted into the pin hole in the piston-side end, and the pin hole of the piston is formed. There is known a lubricating structure for a piston and a connecting rod inserted in a piston. An example of this type of lubricating structure for a piston and a connecting rod is disclosed in Japanese Utility Model Laid-Open No. 5-12612, for example. Also, an oil inflow hole is formed in the upper portion of the hollow piston pin so that oil can flow in from the outer upper portion of the hollow piston pin to the inner side, and the piston pin is formed in such a manner that oil can flow out of the hollow piston pin to the outer lower portion of the hollow piston pin. There is known a lubricating structure of a piston and a connecting rod having an oil outflow hole formed in a lower portion of the piston.

[0005] However, Japanese Utility Model Laid-Open No. Hei 5-12612 discloses that oil flowing into the inside of a hollow piston pin moves in the longitudinal direction of the piston pin and collects in an oil outflow hole.
There is no disclosure of a hollow piston pin formed by inclining the inner wall surface. In the above-described known lubrication structure of the piston and the connecting rod, the inner wall surface of the hollow piston pin is not formed to be inclined in the longitudinal direction of the piston pin. Therefore, the oil flowing into the hollow piston pin cannot be moved in the longitudinal direction of the piston pin and collected in the oil outflow hole.

Further, in the above-described known piston and connecting rod lubrication structure in which an oil outflow hole is formed in the lower part of the piston pin so that oil can flow out from the inside to the lower part of the outside of the hollow piston pin, the lower part of the hollow piston pin Is not longer than the upper longitudinal length of the hollow piston pin. Therefore, the oil falling from the upper side of the hollow piston pin to the lower side cannot be collected inside the hollow piston pin through the opening formed at the end of the hollow piston pin in the longitudinal direction.

In addition, there is known an internal combustion engine piston having an oil ring groove for mounting an oil ring and a pin hole for inserting a piston pin, wherein the oil ring groove and the pin hole are connected by an oil supply passage. Have been.
As an example of this type of piston for an internal combustion engine, there is one described in, for example, JP-A-8-232624.

However, in the piston for an internal combustion engine described in JP-A-8-232624, the oil supply passage is formed inside the piston and is not exposed to the air in the cylinder. Therefore, the oil moving in the oil supply passage cannot be effectively cooled.

An oil ring groove for mounting an oil ring and a pin boss having a pin hole for inserting a piston pin are provided, and an oil ring groove cooling channel to which oil for cooling the oil ring groove is supplied is formed. BACKGROUND ART A piston for an internal combustion engine having a pin boss cooling channel to which cooling oil is supplied is known.
An example of this type of piston for an internal combustion engine is disclosed in, for example, JP-A-9-72215.

However, in the piston for an internal combustion engine described in Japanese Patent Application Laid-Open No. 9-72215, the oil ring groove cooling channel is formed in an annular shape, and the oil ring groove cooling channel and the pin boss cooling channel are communicated with each other. However, the entire pin boss cannot be effectively cooled because the pin boss cooling channel is not annular.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a piston and connecting rod lubrication structure in which oil lubricating the piston and connecting rod can be reused for lubricating the piston and connecting rod. .

Further, the present invention is to make sure that the oil flowing into the inside of the hollow piston pin is allowed to flow out from the inside of the hollow piston pin and to reliably lubricate the sliding surface between the lower outside of the piston pin and the pin hole of the piston. It is an object of the present invention to provide a lubricating structure for a piston and a connecting rod that can perform the lubrication.

Further, the present invention provides a piston capable of collecting oil falling from the upper side to the lower side of the hollow piston pin inside the hollow piston pin through an opening formed at a longitudinal end of the hollow piston pin. And a lubricating structure for the connecting rod.

Another object of the present invention is to provide a piston for an internal combustion engine that can effectively cool oil moving in an oil supply passage communicating an oil ring groove with a pin hole of the piston.

Another object of the present invention is to provide a piston for an internal combustion engine that can effectively cool the entire pin boss of the piston.

[0016]

According to the present invention, a pin boss having a pin hole is formed on a piston,
The piston-side end of the connecting rod was branched and arranged on both sides of the pin boss, a pin hole was formed in the piston-side end, and a piston pin was inserted into the pin hole of the piston and the pin hole of the piston-side end. In a lubricating structure for a piston and a connecting rod, a piston and a connecting rod having an oil sump recess formed at a portion located below the pin boss and the piston pin at a forked portion of the branched piston side end. Lubrication structure is provided.

In the lubricating structure for a piston and a connecting rod according to the first aspect, an oil reservoir recess is formed at a fork of the branched piston side end and located below the pin boss and the piston pin. Is done. Therefore, it is possible to prevent the oil lubricating the piston and the connecting rod from dropping through the fork. The oil stored in the oil storage recess is springed up when the piston is raised, and is used again for lubrication of the piston and the connecting rod. That is, the oil lubricating the piston and the connecting rod can be used again for lubricating the piston and the connecting rod.

According to the second aspect of the present invention, the pin boss surface facing the oil reservoir recess and the pin hole of the piston are communicated with each other by the oil introduction passage.
And a lubricating structure for a connecting rod.

In the lubricating structure for the piston and the connecting rod according to the second aspect, the pin boss surface facing the oil reservoir recess and the pin hole of the piston communicate with each other through the oil introduction passage. Therefore, when the piston is raised, the oil in the oil reservoir recess can be supplied into the pin hole of the piston.

According to the third aspect of the present invention, the pin boss is connected to the oil sump such that an inlet on the pin boss surface side of the oil introduction passage is immersed in the oil accumulated in the oil sump recess. A lubricating structure for a piston and a connecting rod according to claim 2, which is disposed with respect to the recess for use.

In the lubrication structure of the piston and the connecting rod according to the third aspect, the pin boss is provided in the oil reservoir so that the inlet on the surface of the pin boss of the oil introduction passage is immersed in the oil stored in the oil reservoir recess. It is arranged with respect to the recess. Therefore, the oil in the oil reservoir concave portion can be more reliably supplied to the pin hole of the piston.

According to the fourth aspect of the present invention, a pin boss having a pin hole is formed on the piston, a pin hole is formed on the piston side end of the connecting rod, and the hollow piston pin is formed on the piston side end. An oil outflow hole was formed in the lower part of the piston pin so as to be inserted into the pin hole and the pin hole of the piston and fixed to one of them, so that oil could flow out from the inside of the hollow piston pin to the outside lower part, In the lubrication structure of the piston and the connecting rod, the inner wall surface of the hollow piston pin is formed so as to be inclined so that oil flowing into the hollow piston pin moves in the longitudinal direction of the piston pin and collects in the oil outflow hole. A lubrication structure for a piston and a connecting rod is provided.

In the lubricating structure of the piston and the connecting rod according to the fourth aspect, since the inner wall surface of the hollow piston pin is formed to be inclined, the oil flowing inside the hollow piston pin moves in the longitudinal direction of the piston pin. At least the oil is collected in the oil outflow hole, and is reliably discharged from the inside of the hollow piston pin, so that the sliding surface between the lower portion of the outside of the piston pin and the pin hole of the piston can be reliably lubricated.

According to the fifth aspect of the present invention, a pin boss having a pin hole is formed in the piston, a pin hole is formed in the piston-side end of the connecting rod, and the hollow piston pin is formed in the piston-side end. An oil outflow hole was formed in the lower part of the piston pin so as to be inserted into the pin hole and the pin hole of the piston and fixed to one of them, so that oil could flow out from the inside of the hollow piston pin to the outside lower part, In the lubrication structure of the piston and the connecting rod, by forming an opening at the longitudinal end of the hollow piston pin, by making the lower longitudinal length of the hollow piston pin longer than the upper longitudinal length of the hollow piston pin. The oil falling from the upper side to the lower side of the hollow piston pin enters the hollow piston pin through the opening. Lubricating structure for a piston and connecting rod which is to be condensed is provided.

In the lubricating structure for a piston and a connecting rod according to the fifth aspect, an opening is formed at a longitudinal end of the hollow piston pin, and the lower longitudinal length of the hollow piston pin is equal to the upper longitudinal length of the hollow piston pin. Longer than the direction length. Therefore, oil that falls from the upper side to the lower side of the hollow piston pin can be collected inside the hollow piston pin through the opening formed at the longitudinal end of the hollow piston pin.

According to the invention described in claim 6, in order to prevent oil collected inside the hollow piston pin from flowing out from the longitudinal end of the hollow piston pin,
The lubricating structure for a piston and a connecting rod according to claim 5, wherein an oil outflow preventing wall is provided at an end in the longitudinal direction of the hollow piston pin.

In the lubricating structure for a piston and a connecting rod according to a sixth aspect of the present invention, an oil outflow preventing wall is provided at a longitudinal end of the hollow piston pin. It can be prevented from flowing out from the direction end.

According to the present invention, an oil ring groove for mounting an oil ring and a pin hole for inserting a piston pin are provided, and the oil ring groove and the pin hole are supplied with oil. An internal combustion engine piston is provided, wherein at least a part of the oil supply passage is formed by a thin-walled pipe and the thin-walled pipe is exposed to air in a cylinder.

In the piston for an internal combustion engine according to the present invention, at least a part of the oil supply passage which communicates the oil ring groove with the pin hole of the piston is formed by a thin tube, and the thin tube is connected to the air in the cylinder. It is exposed. Therefore, the oil moving in the oil supply passage can be effectively cooled.

According to the eighth aspect of the present invention, there is provided an oil ring groove for mounting an oil ring and a pin boss having a pin hole for inserting a piston pin, and oil for cooling the oil ring groove is provided. In a piston for an internal combustion engine having a pin boss cooling channel formed with an oil ring groove cooling channel to be supplied and oil for cooling the pin boss, the pin boss cooling channel is formed in an annular shape and the oil ring is formed. The groove cooling channel and the pin boss cooling channel are communicated with each other so that oil flowing into the pin boss cooling channel from the oil ring groove cooling channel can move the oil in the pin boss cooling channel in the circumferential direction. The piston is provided.

In the piston for an internal combustion engine according to the present invention, the pin boss cooling channel is formed in an annular shape, and the oil ring groove cooling channel and the pin boss cooling channel are communicated with each other. Therefore, the oil flowing in the pin boss cooling channel from the oil ring groove cooling channel into the pin boss cooling channel causes the oil in the pin boss cooling channel to move in the circumferential direction, so that the entire pin boss of the piston can be effectively cooled.

[0032]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view showing a first embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.
2 is an enlarged view of FIG. 1, and FIG. 3 is a top view of the connecting rod. 1 to 3, reference numeral 1 denotes a piston, 2 denotes a pin boss, 3 denotes a pin hole formed in the pin boss 2, 4 denotes a connecting rod, and 5 denotes a branched end (small end) on the piston side. Reference numeral 6 denotes a pin hole formed in the piston-side end portion 5 of the connecting rod 4, and 7 denotes a piston 1
The piston pin 8 inserted into the pin hole 3 of the connecting rod 4 and the pin hole 6 of the connecting rod 4 is a fork of the branched piston side end 5. Reference numeral 9 denotes an oil sump recess formed in the fork 8 located below the pin boss 2 and the piston pin 7, and 10 denotes an oil that communicates the pin boss surface facing the oil sump recess 9 with the pin hole 3 of the piston 1. An introduction passage, 11 is an inlet on the pin boss surface side of the oil introduction passage 10;
Reference numeral 12 denotes a liquid level of the oil in the oil reservoir recess 9.

As shown in FIGS. 1 to 3, an oil reservoir recess 9 is formed in the fork 8 of the piston-side end 5 of the connecting rod 4, so that, for example, an oil jet, a crank journal end face, a connecting rod shoulder, The oil supplied by lubrication or the like lubricates the piston and the connecting rod, and more specifically, lubricates between the pin hole 3 and the piston pin 7 and between the pin hole 6 and the piston pin 7, and then collects the oil. Is stored in the recess 9.
The oil stored in the oil storage recess 9 is springed upward by the inertial force of the piston 1 and is used again for lubrication of the piston and the connecting rod.

Further, since the oil introduction passage 10 is formed, the oil in the oil reservoir recess 9 is directly transferred to the pin hole 3.
And between the piston pin 7. Further, since the pin boss surface side entrance 11 of the oil introduction passage 10 is disposed so as to be immersed in the oil in the oil reservoir recess 9, the oil in the oil reservoir recess 9 is supplied to the pin hole 3.
And the piston pin 7 can be more reliably supplied. By promoting lubrication of pin holes,
Scuffing and seizure of the piston pin 7 and the pin holes 3 and 6 are suppressed, and the fuel consumption is improved by reducing the friction therebetween. The posture is improved and seizure with the bore is prevented.

The cooling of the area around the pin boss 2 is promoted by the oil splashed from the oil reservoir recess 9, so that the clearance between the piston pin 7 and the pin holes 3, 6 is optimally maintained and seizure is prevented. You. Further, since the entire piston ring groove, piston head, and the like are also cooled, wear of each sliding portion is reduced. Further, since the piston end 5 of the connecting rod 4 is also cooled, the heat strength of the material is increased, and the rigidity is improved, so that the weight of the connecting rod 4 is reduced. In addition, since the oil reservoir recess 9 can be formed without the need for machining, an increase in cost can be prevented. Further, since a wall for maintaining the oil level 12 at a relatively high position is formed, the wall acts as a rib, so that the fork 8 is prevented from being deformed.

FIG. 4 is a top view of a connecting rod similar to FIG. 3 of a second embodiment of a lubrication structure for a piston and a connecting rod according to the present invention. In FIG. 4, 1
Reference numerals 09 and 109 ′ denote three-parted oil reservoir recesses. The depths of the oil reservoir recesses 109 and 109 'are set so that the oil is splashed in a desired direction. For example, the depth of the central oil reservoir recess 109 is increased, and the depth of the oil reservoir recesses 109 ′ on both sides is reduced. When the depth of the oil reservoir recesses 109 'on both sides is reduced, the thickness of both ends of the connecting rod is ensured, and a reduction in the strength of the connecting rod can be suppressed. Also, the oil reservoir recesses 109, 10
Since the wall between the 9's serves as a rib, it is possible to achieve both reduction in weight and increase in strength.

FIG. 5 is a sectional view of a third embodiment of a lubrication structure for a piston and a connecting rod according to the present invention, and FIG. 6 is a sectional view taken along line VI-VI of FIG. 5 and 6, the reference numbers shown in FIGS. 1 to 4 indicate the same parts or parts as those shown in FIGS. 1 to 4, 101 is a piston, 102 is a pin boss, and 103 is A pin hole formed in the pin boss 102, 110 is a lower oil introduction passage, 12
1 is an upper oil introduction passage, 125 is an oil ring groove, 1
20 is an oil ring groove 125 and an upper oil introduction passage 12
1 is an oil passage communicating with the oil passage 1. According to the present embodiment, oil can be supplied to the pin hole 103 and the piston pin 7 not only from the lower oil introduction passage 110 but also from the upper oil introduction passage 121. Further, the lubrication of the pin hole 103 is improved, so that the surface pressure can be reduced,
The diameter and the length of the shaft of the piston pin 7 can be reduced, and the weight can be reduced. Further, in the present embodiment, since the pin boss 102 is arranged at the center of the piston 101, even when the upper oil introduction passage 121 is formed, no bending moment is applied to the pin boss 102, and the deformation of the piston 101 is prevented. Be avoided.

FIG. 7 is a sectional view of a fourth embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.
Since the connecting rod and the piston pin are the same as those shown in FIGS. 1 to 3, only the piston is shown in FIG. In FIG. 7, 101 'is a piston, 102'
Is a pin boss, 103 'is a pin hole, 110' is a lower oil introduction passage, 121 'is an upper oil introduction passage, and 120' is a lower part of the piston 101 'and an upper oil introduction passage 121'.
And an oil passage communicating with the oil passage. According to the present embodiment,
Since the oil passage 120 'is communicated with the lower part of the piston 101', oil from an oil jet or intermittent lubrication of the connecting rod can be supplied to the pin hole 103 '. In the center boss type piston 101 ', since the rigidity at the center of the piston is relatively high, it is possible to steal meat by forming the oil passage 120' and the upper oil introduction passage 121 '.

FIG. 8 is a sectional view of a fifth embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.
Since the connecting rod and the piston pin are the same as those shown in FIGS. 1 to 3, only the piston is shown in FIG. In FIG. 8, 101 ″ is a piston, 102 ″
Is a pin boss, 103 "is a pin hole, 110" is a lower oil introduction passage, and 120 "is an oil passage communicating the lower side of the piston 101" with the pin hole 103 ". According to the present embodiment, the piston 101" And the pin hole 103 "are communicated only through the oil passage 120" without passing through the upper oil introduction passage, so that the compression height H can be made smaller than that shown in FIG.
Also, since a compressive load and a tensile load hardly act on both sides of the pin boss 102 ″, the pin hole 103 ″ can be lubricated without reducing the strength of the pin boss 102 ″ even if the oil passage 120 ″ is formed. Further, the diameter of the oil passage 120 "on the side facing the lower part of the piston 101" is larger than the diameter on the side facing the pin hole 103 ". The oil supply to the "" is improved.

FIG. 9 is a sectional view of a sixth embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.
In FIG. 9, 201 is a piston, 202 is a pin boss,
203 is a pin hole formed in the pin boss 202, 204 is a connecting rod, and 205 is a branched side end (small end) of the piston. Reference numeral 206 denotes a pin hole formed in the piston side end 205 of the connecting rod 204, and 207 denotes a pin hole 20 of the connecting rod 204.
The hollow piston pin 208 fixed to 6 and inserted into the pin hole 203 of the piston 201 is a fork of the branched piston side end 205. 220 is the upper outside of the hollow piston pin 207, 221 is the hollow piston pin 20
7, 222 is an oil inflow hole formed in the upper portion of the hollow piston pin so that oil can flow into the inner side 221 from the outer upper portion 220 of the hollow piston pin 207.
Reference numeral 223 denotes an outer lower portion of the hollow piston pin 207, and 224 denotes an inner lower portion 22 to an outer lower portion
3 so that oil can flow out to the hollow piston pin 207.
It is an oil outflow hole formed in the lower part of. Reference numeral 225 denotes an inner wall surface of the hollow piston pin which is inclined so that oil flowing into the inside of the hollow piston pin 207 moves in the longitudinal direction of the piston pin and collects in the oil outlet hole 224.

According to this embodiment, since the inner wall surface 225 of the hollow piston pin is formed to be inclined, the oil flowing into the inner side 221 of the hollow piston pin 207 is moved in the longitudinal direction of the piston pin, and the oil outlet hole is formed. By collecting the fluid into the inside of the hollow piston pin 207 and letting it flow out from the inside 221 of the hollow piston pin 207, the sliding surface between the outer lower portion 223 of the hollow piston pin 207 and the pin hole 203 of the piston can be surely lubricated. Further, since the wall pressure at the lower longitudinal end of the piston pin 207 is thicker than the wall pressure at the center in the longitudinal direction, when the piston pin 207 is pressed into the pin hole 203 of the piston 201, the longitudinal direction of the piston pin 207 is reduced. The end can be prevented from being deformed.

In this embodiment, the piston pin 207
Is fixed to the pin hole 206 of the connecting rod 204 without being fixed to the pin hole 203 of the piston 201. However, in a modification of this embodiment, the piston pin is fixed to the pin hole of the piston and fixed to the pin hole of the connecting rod. It may not be done.

FIG. 10 is a sectional view of a seventh embodiment of a lubrication structure for a piston and a connecting rod according to the present invention. 10, the same reference numerals as those shown in FIG. 9 indicate the same parts or portions as those shown in FIG. 9, and reference numeral 307 denotes a connecting rod 204.
The pin hole 206 of the piston 201 is fixed to the pin hole 206 of the piston 201.
03, 321 is the inside of the hollow piston pin 207, 323 is the hollow piston pin 30.
7 is a lower portion outside. 324 is a hollow piston pin 307
An oil outflow hole formed in the lower portion of the hollow piston pin 307 so that oil can flow out from the inside 321 to the outside lower portion 323. 330 is an opening formed at the longitudinal end of the hollow piston pin 307, 331 is a lower part of the hollow piston pin 307, 332 is an upper part of the hollow piston pin 307, 333 is an oil outflow arranged at a longitudinal end of the hollow piston pin 307. It is a prevention wall.

As shown in FIG. 10, an opening 330 is formed at the longitudinal end of the hollow piston pin 307, and the longitudinal length of the lower portion 331 of the hollow piston pin 307 is longer than the longitudinal length of the upper portion 332 of the hollow piston pin 307. The oil falling from the upper side to the lower side of the hollow piston pin (arrow in the drawing) is directed to the inside 321 of the hollow piston pin 307 through the opening 330 formed at the longitudinal end of the hollow piston pin 307. Can be collected. Also,
Oil outflow prevention wall 333 at the longitudinal end of the hollow piston pin
Is provided, the inner side 32 of the hollow piston pin 307 is provided.
1 can be prevented from flowing out from the longitudinal end of the hollow piston pin. Further, since the oil outflow prevention wall 333 serves as a rib, the deformation of the opening 330 can be prevented.

In this embodiment, the piston pin 307 is used.
Is fixed to the pin hole 206 of the connecting rod 204 without being fixed to the pin hole 203 of the piston 201. However, in a modification of this embodiment, the piston pin is fixed to the pin hole of the piston and fixed to the pin hole of the connecting rod. It may not be done.

FIG. 11 is a sectional view of an eighth embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.
FIG. 2 is a sectional view taken along the line XII-XII of FIG. 11 and 1
2, the same reference numerals as those shown in FIGS. 1 to 10 denote the same parts or parts as those shown in FIGS. 1 to 10, reference numeral 401 denotes a piston, 402 denotes a pin boss, 403. Is a pin hole formed in the pin boss 402, 410 is a lower oil introduction passage, and 425 is an oil ring groove. 420 is an oil supply passage for communicating the oil ring groove 425 with the pin hole 403 of the piston 401; 421 is an upper oil introduction passage for communicating the oil ring groove 425 with the pin hole 403 of the piston 401;
422 is a thin-walled tube forming at least a part of the oil supply passage 420.

As shown in FIGS. 11 and 12, at least a part of the oil supply passage 420 communicating the oil ring groove 425 and the pin hole 403 of the piston 401 has a thin pipe 4.
22, the thin-walled pipe 422 is exposed to the air in the cylinder, so that the oil moving in the oil supply passage 420 can be effectively cooled. Also,
When the thin tube is formed of a lightweight material such as a resin, the weight of the piston 401 can be reduced. Furthermore, when the thin-walled tube has a double structure and a refrigerant is sealed in the thin-walled tube,
Oil cooling efficiency can be improved.

FIG. 13 is a sectional view of a ninth embodiment of a lubrication structure for a piston and a connecting rod according to the present invention. In FIG. 13, the same reference numerals as those shown in FIGS. 1 to 12 indicate the same parts or parts as those shown in FIGS.
502 is a pin boss, 503 is a pin hole formed in the pin boss 502, 510 is a lower oil introduction passage, and 525 is an oil ring groove. 520 is an oil supply passage for communicating the oil ring groove 525 with the pin hole 503 of the piston 501, and 521 is an oil supply passage for the oil ring groove 525 and the piston 5
The upper oil introduction passage 522 for communicating with the pin hole 503 of No. 01 is a thin tube forming at least a part of the oil supply passage 520.

As shown in FIG. 13, the thin-walled tube 522 of this embodiment is arranged at a predetermined angle θ (> 0) with respect to a plane perpendicular to the central axis of the piston 501. That is,
The thin-walled tube 522 plays a role of a strut for preventing the piston head from being deformed as shown by an arrow in the drawing, in addition to the operation shown in FIGS.

FIG. 14 is a sectional view of a tenth embodiment of a lubrication structure for a piston and a connecting rod of the present invention, and FIG. 15 is a sectional view showing the oil ring groove cooling channel and the pin boss cooling channel of FIG. 14 on the same plane. is there. 14 and 15, reference numeral 601 denotes a piston, 602 denotes a pin boss, 603 denotes a pin hole formed in the piston 601, 625 denotes an oil ring groove, and 650 denotes an oil ring to which oil for cooling the oil ring groove 625 is supplied. It is a groove cooling channel. 651 is a pin boss cooling channel to which oil for cooling the pin boss 602 is supplied, 652 is a communication path communicating the oil ring groove cooling channel 650 and the pin boss cooling channel 651, and 653 is a pin hole for oil in the pin boss cooling channel 651. This is an oil pit for dropping to 603.

As shown in FIGS. 14 and 15, the pin boss cooling channel 651 is formed in an annular shape, and the oil ring groove cooling channel 650 and the pin boss cooling channel 651 are communicated by the communication passage 652. 6
Oil flowing into the pin boss cooling channel 651 from the pin boss cooling channel 651
1 is moved in the circumferential direction, so that the entire pin boss 602 of the piston 601 is effectively cooled. By effectively cooling the pin boss 602,
The cooling performance of the pin (not shown) inserted in the pin hole 603 is improved, and the generally known pin hole bush and pin hole surface treatment can be eliminated, thereby reducing the cost of the piston 601. .

[0053]

According to the first aspect of the present invention, it is possible to prevent the oil lubricating the piston and the connecting rod from dropping through the fork and drop the oil lubricating the piston and the connecting rod. And can be used again for lubricating the connecting rod.

According to the second aspect of the invention, when the piston is lifted, the oil in the oil reservoir recess can be supplied into the pin hole of the piston.

According to the third aspect of the present invention, the oil in the oil reservoir recess can be more reliably supplied to the pin hole of the piston.

According to the fourth aspect of the present invention, the oil which has flowed into the inside of the hollow piston pin is moved in the longitudinal direction of the piston pin and collected in the oil outflow hole, so that the oil flows out of the hollow piston pin without fail. Thereby, the sliding surface between the lower outside of the piston pin and the pin hole of the piston can be reliably lubricated.

According to the fifth aspect of the invention, the oil falling from the upper side to the lower side of the hollow piston pin is captured inside the hollow piston pin through the opening formed at the longitudinal end of the hollow piston pin. Can be gathered.

According to the sixth aspect of the invention, it is possible to prevent the oil collected inside the hollow piston pin from flowing out from the longitudinal end of the hollow piston pin.

According to the seventh aspect of the invention, the oil moving in the oil supply passage can be effectively cooled.

According to the eighth aspect of the present invention, the oil flowing into the pin boss cooling channel from the oil ring groove cooling channel causes the oil in the pin boss cooling channel to move in the circumferential direction, thereby effecting the entire pin boss of the piston. Cooling.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.

FIG. 2 is an enlarged view of FIG.

FIG. 3 is a top view of the connecting rod.

4 is a top view of a connecting rod similar to FIG. 3 of a second embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.

FIG. 5 is a sectional view of a third embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.

FIG. 6 is a sectional view taken along line VI-VI of FIG. 5;

FIG. 7 is a sectional view of a fourth embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.

FIG. 8 is a sectional view of a fifth embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.

FIG. 9 is a sectional view of a sixth embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.

FIG. 10 is a sectional view of a seventh embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.

FIG. 11 is a sectional view of an eighth embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.

FIG. 12 is a sectional view taken along the line XII-XII of FIG. 11;

FIG. 13 is a cross-sectional view of a ninth embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.

FIG. 14 is a sectional view of a tenth embodiment of a lubrication structure for a piston and a connecting rod according to the present invention.

FIG. 15 is a sectional view showing the oil ring groove cooling channel and the pin boss cooling channel of FIG. 14 on the same plane.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Piston 2 ... Pin boss 3 ... Pin hole 4 ... Connecting rod 5 ... Piston side end 6 ... Pin hole 7 ... Piston pin 8 ... Fork 9 ... Recess for oil sump

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Noriyuki 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Hiroshi Arisawa 1 Toyota Town Toyota City, Aichi Prefecture Toyota Motor Corporation ( 72) Inventor Yukio Okochi 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Kiyoshi Fujiwara 1 Toyota Town Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Yonari Maeda Tokyo Metropolitan Government 6-14-5 Ginza, Chuo-ku Art Metal Industry Co., Ltd. (72) Inventor Koichi Suzuki 6-14-5 Ginza, Chuo-ku, Tokyo Art Metal Industry Co., Ltd. F-term (reference) 3G013 BA01 BA04 BC03 BC04 BD31 BD32 CA15

Claims (8)

[Claims] 1. A pin boss having a pin hole is formed in a piston, an end of a connecting rod on a piston side is branched and arranged on both sides of the pin boss, and a pin hole is formed in the end of the piston to form a piston pin. In the lubrication structure of the piston and the connecting rod, which is inserted into the pin hole of the piston and the pin hole of the piston side end, the fork of the branched piston side end is provided below the pin boss and the piston pin. A lubricating structure for a piston and a connecting rod having an oil reservoir recess formed in a portion located on the side. 2. The lubricating structure for a piston and a connecting rod according to claim 1, wherein a pin boss surface facing the oil reservoir recess and a pin hole of the piston are communicated by an oil introduction passage. 3. The pin boss is arranged in the oil sump recess so that an inlet on the pin boss surface side of the oil introduction passage is immersed in the oil accumulated in the oil sump recess. The lubricating structure for a piston and a connecting rod according to the above. 4. A pin boss having a pin hole is formed on a piston, a pin hole is formed on a piston side end of a connecting rod, and a hollow piston pin is formed on a pin hole on the piston side end and a pin hole on the piston. In a lubrication structure for a piston and a connecting rod, an oil outflow hole is formed in a lower portion of the piston pin so as to be inserted and fixed to one of them, so that oil can flow out from the inside of the hollow piston pin to the outside lower portion, A lubrication structure for a piston and a connecting rod formed by inclining an inner wall surface of the hollow piston pin so that oil flowing into the hollow piston pin moves in the longitudinal direction of the piston pin and collects in the oil outflow hole. 5. A pin boss having a pin hole is formed in a piston, a pin hole is formed in a piston side end of a connecting rod, and a hollow piston pin is formed in a pin hole in the piston side end and a pin hole in the piston. In a lubrication structure for a piston and a connecting rod, an oil outflow hole is formed in a lower portion of the piston pin so as to be inserted and fixed to one of them, so that oil can flow out from the inside of the hollow piston pin to the outside lower portion, An opening is formed at the longitudinal end of the hollow piston pin, and the lower longitudinal length of the hollow piston pin is made longer than the longitudinal length of the upper part of the hollow piston pin, so that the lower side of the hollow piston pin is lowered. A piston configured to collect oil falling to the side through the opening inside the hollow piston pin; And connecting rod lubrication structure. 6. An oil outflow prevention wall is provided at the longitudinal end of the hollow piston pin to prevent oil collected inside the hollow piston pin from flowing out from the longitudinal end of the hollow piston pin. A lubricating structure for a piston and a connecting rod according to claim 5. 7. An internal combustion engine piston having an oil ring groove for mounting an oil ring and a pin hole for inserting a piston pin, wherein the oil ring groove and the pin hole are connected by an oil supply passage. Forming at least a part of the oil supply passage with a thin-walled tube,
An internal combustion engine piston in which the thin tube is exposed to air in a cylinder. 8. An oil ring groove for mounting an oil ring and a pin boss having a pin hole for inserting a piston pin, wherein an oil ring groove cooling channel to which oil for cooling the oil ring groove is supplied. In the piston for an internal combustion engine formed and formed with a pin boss cooling channel to which oil for cooling the pin boss is supplied, the pin boss cooling channel is formed in an annular shape, and the oil ring groove cooling channel and the pin boss cooling channel are formed. A piston for an internal combustion engine, wherein oil in the pin boss cooling channel is moved in a circumferential direction by oil flowing into the pin boss cooling channel from the oil ring groove cooling channel.