Piston structure for engine

Patent metadata

Field	Value
Publication number	US-9556821-B2
Application number	US-201414464543-A
Country	US
Kind code	B2
Filing date	Aug 20, 2014
Priority date	Sep 18, 2013
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

A piston structure for an engine is provided. The piston structure includes a piston for reciprocating within a cylinder, a connecting rod having a smaller-end part and a larger-end part in both ends, respectively, the smaller-end part coupled to the piston, the larger-end part coupled to a crankshaft, a cross-sectionally hollow piston pin coupling the piston to the smaller-end part, and a dynamic absorber provided inside the piston pin, including a fixed part fixed to the piston pin and a movable part pivotally supported by the fixed part, and for suppressing the piston, the piston pin, and the smaller-end part from integrally resonating with respect to the larger-end part of the connecting rod on combustion stroke. The dynamic absorber includes an assemblable dynamic absorber in which the movable part is formed by attaching a mass adjusting part to the fixed part.

First claim

What is claimed is:

1. A piston structure for an engine, comprising:
a piston for reciprocating within a cylinder;
a connecting rod having a smaller-end part and a larger-end part in both ends, respectively, the smaller-end part coupled to the piston, the larger-end part coupled to a crankshaft;
a cross-sectionally hollow piston pin coupling the piston to the smaller-end part; and
a dynamic absorber provided inside the piston pin, including a fixed part fixed to the piston pin and a movable part pivotally supported by the fixed part, and for suppressing the piston, the piston pin, and the smaller-end part from integrally resonating with respect to the larger-end part of the connecting rod on combustion stroke,
wherein the dynamic absorber includes an assemblable dynamic absorber in which the movable part is formed by attaching a mass adjusting part to the fixed part.

2. The piston structure of claim 1 , wherein the dynamic absorber includes two dynamic absorbers, and
wherein the two dynamic absorbers are located sandwiching therebetween a plane passing through the center of the piston pin in an axial direction thereof.

3. The piston structure of claim 2 , wherein one of the dynamic absorbers is the assemblable dynamic absorber, and the other dynamic absorber is an integrated dynamic absorber in which the fixed part and the movable part are formed integrally.

4. The piston structure of claim 2 , wherein both of the dynamic absorbers are the assemblable dynamic absorbers.

5. The piston structure of claim 1 , wherein the fixed part has a shaft extending in an axial direction of the piston pin,
wherein the mass adjusting part has an insertion hole into which the shaft is inserted,
wherein the mass adjusting part is attached to the fixed part by inserting the shaft into the insertion hole, and
wherein an axial positioning part for positioning the mass adjusting part with respect to the shaft is provided between the insertion hole and the shaft.

6. The piston structure of claim 2 , wherein the fixed part has a shaft extending in the axial direction of the piston pin,
wherein the mass adjusting part has an insertion hole into which the shaft is inserted,
wherein the mass adjusting part is attached to the fixed part by inserting the shaft into the insertion hole, and
wherein an axial positioning part for positioning the mass adjusting part with respect to the shaft is provided between the insertion hole and the shaft.

7. The piston structure of claim 3 , wherein the fixed part has a shaft extending in the axial direction of the piston pin,
wherein the mass adjusting part has an insertion hole into which the shaft is inserted,
wherein the mass adjusting part is attached to the fixed part by inserting the shaft into the insertion hole, and
wherein an axial positioning part for positioning the mass adjusting part with respect to the shaft is provided between the insertion hole and the shaft.

8. The piston structure of claim 4 , wherein the fixed part has a shaft extending in the axial direction of the piston pin,
wherein the mass adjusting part has an insertion hole into which the shaft is inserted,
wherein the mass adjusting part is attached to the fixed part by inserting the shaft into the insertion hole, and
wherein an axial positioning part for positioning the mass adjusting part with respect to the shaft is provided between the insertion hole and the shaft.

9. The piston structure of claim 5 , wherein the axial positioning part includes a restricting face provided to the shaft to face an inserting direction of the mass adjusting part, and a contact face for contacting with the restricting face and provided to the mass adjusting part, and
wherein the restricting face is located on a tip end side of the shaft.

10. The piston structure of claim 1 , wherein the fixed part has a shaft extending in an axial direction of the piston pin,
wherein the mass adjusting part has an insertion hole into which the shaft is inserted,
wherein the mass adjusting part is attached to the fixed part by inserting the shaft into the insertion hole, and
wherein a retaining part for preventing the mass adjusting part from being removed from the shaft is provided between the mass adjusting part and a protruding tip end part formed in the shaft to protrude beyond the mass adjusting part.

11. The piston structure of claim 2 , wherein the fixed part has a shaft extending in the axial direction of the piston pin,
wherein the mass adjusting part has an insertion hole into which the shaft is inserted,
wherein the mass adjusting part is attached to the fixed part by inserting the shaft into the insertion hole, and
wherein a retaining part for preventing the mass adjusting part from being removed from the shaft is provided between the mass adjusting part and a protruding tip end part formed in the shaft to protrude beyond the mass adjusting part.

12. The piston structure of claim 3 , wherein the fixed part has a shaft extending in the axial direction of the piston pin,
wherein the mass adjusting part has an insertion hole into which the shaft is inserted,
wherein the mass adjusting part is attached to the fixed part by inserting the shaft into the insertion hole, and
wherein a retaining part for preventing the mass adjusting part from being removed from the shaft is provided between the mass adjusting part and a protruding tip end part formed in the shaft to protrude beyond the mass adjusting part.

13. The piston structure of claim 4 , wherein the fixed part has a shaft extending in the axial direction of the piston pin,
wherein the mass adjusting part has an insertion hole into which the shaft is inserted,
wherein the mass adjusting part is attached to the fixed part by inserting the shaft into the insertion hole, and
wherein a retaining part for preventing the mass adjusting part from being removed from the shaft is provided between the mass adjusting part and a protruding tip end part formed in the shaft to protrude beyond the mass adjusting part.

14. The piston structure of claim 10 , wherein the retaining part is structured by attaching a fixed clip to the protruding tip end part.

15. The piston structure of claim 10 , wherein the retaining part is formed by crimping the protruding tip end part.

16. The piston structure of claim 10 , wherein the retaining part is formed by crimping the mass adjusting part.

17. The piston structure of claim 16 , wherein the retaining part includes a crimped part formed by crimping the mass adjusting part, and an inhibiting part provided in an outer face of the shaft so as to be in contact with the crimped part when the mass adjusting part is displaced in a removing direction thereof.

18. The piston structure of claim 16 , wherein a restricting face facing in an inserting direction of the mass adjusting part and for contacting with the mass adjusting part is formed in the shaft at a position near the retaining part and closer to a base end side of the shaft than the retaining part.

19. The piston structure of claim 17 , wherein a restricting face facing in an inserting direction of the mass adjusting part and for contacting with the mass adjusting part is formed in the shaft at a position near the retaining part and closer to a base end side of the shaft than the retaining part.

Assignees

• Mazda Motor

Inventors

• Hirata Koichi
• Yamaya Mitsutaka
• Takuma Shuji
• Kanda Yasunori
• Kobayashi Tatsuya
• Motomuro Takeshi

Classifications

• F02F3/0015 Primary

  Multi-part pistons · CPC title

• F16J1/16

  with gudgeon-pin; Gudgeon-pins · CPC title

• F02B75/06

  Engines with means for equalising torque · CPC title

• F02F3/0069 Primary

  the crown and skirt being interconnected by the gudgeon pin · CPC title

• F02F2200/02

  Riveting · CPC title