Crank cap assembly and internal combustion engine

Patent metadata

Field	Value
Publication number	US-10851869-B2
Application number	US-201816209157-A
Country	US
Kind code	B2
Filing date	Dec 4, 2018
Priority date	Dec 15, 2017
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

A crank cap assembly provided with a crank cap rotatably supporting a crankshaft includes a mass portion, two cap bolts fixing the crank cap to an engine body, and an elastic supporter disposed between the two cap bolts. The elastic supporter elastically supports the mass portion with respect to the crank cap in an axial direction of the crankshaft.

First claim

What is claimed is:

1. A crank cap assembly provided with a crank cap rotatably supporting a crankshaft, the crank cap assembly comprising:
a mass portion;
two cap bolts fixing the crank cap to an engine body; and
an elastic supporter disposed between the two cap bolts, the elastic supporter elastically supporting the mass portion with respect to the crank cap in an axial direction of the crankshaft, wherein
the elastic supporter includes an attachment bolt attaching the mass portion to the crank cap, and a first elastic body disposed between the mass portion and the crank cap,
the mass portion has a through hole penetrating the mass portion,
the attachment bolt extends through the through hole and attaches the mass portion to the crank cap such that the first elastic body is sandwiched between the mass portion and the crank cap,
the first elastic body is rubber, and
an elastic modulus of a middle portion of the first elastic body is larger than an elastic modulus of both of first end portions of the first elastic body in the axial direction of the crankshaft.

2. The crank cap assembly according to claim 1 , wherein:
the elastic modulus of the middle portion of the first elastic body is larger than an elastic modulus of both of second end portions of the first elastic body in a cap extension direction perpendicular to an attachment direction in which the crank cap is attached to the engine body.

3. The crank cap assembly according to claim 1 , wherein:
the mass portion includes a protruding portion protruding toward the first elastic body formed in a middle portion of the mass portion in the axial direction of the crankshaft and a cap extension direction perpendicular to an attachment direction in which the crank cap is attached to the engine body.

4. The crank cap assembly according to claim 1 , wherein the elastic supporter further includes a second elastic body disposed between the mass portion and a head of the attachment bolt.

5. The crank cap assembly according to claim 4 , wherein:
the first elastic body and the second elastic body are rubber; and
the second elastic body is higher in hardness than the first elastic body.

6. The crank cap assembly according to claim 4 , wherein:
the elastic supporter includes at least two attachment bolts, and a collar disposed between the second elastic body and the head of the attachment bolts; and
the collar is disposed such that the at least two attachment bolts penetrate the collar.

7. The crank cap assembly according to claim 4 , wherein:
the elastic supporter further includes a third elastic body; and
the third elastic body is rubber disposed between the attachment bolt and an inner surface of the through hole.

8. The crank cap assembly according to claim 7 , wherein the first elastic body, the second elastic body, and the third elastic body are rubber and a single member.

9. The crank cap assembly according to claim 1 , wherein the elastic supporter further includes a fourth elastic body disposed between a head of the cap bolt and the mass portion.

10. The crank cap assembly according to claim 1 , wherein:
the mass portion includes a recessed portion; and
a head of the attachment bolt is received in the recessed portion at least in part.

11. The crank cap assembly according to claim 1 , wherein:
the mass portion includes a body portion, and two extending portions extending in parallel toward an outside from the body portion; and
the crank cap is disposed such that a part of the crank cap is received between the two extending portions.

12. The crank cap assembly according to claim 11 , wherein the elastic supporter includes a fifth elastic body disposed between the extending portion and the crank cap.

13. The crank cap assembly according to claim 1 , wherein:
the mass portion includes a plurality of partial mass portions divided in an attachment direction in which the crank cap is attached to the engine body; and
the partial mass portions are configured to be supported with respect to the crank cap at spring constants different from each other in the axial direction of the crankshaft.

14. The crank cap assembly according to claim 13 , wherein a sixth elastic body is provided between the partial mass portions next to each other.

15. The crank cap assembly according to claim 1 , wherein:
the mass portion includes a plurality of partial mass portions divided in the axial direction of the crankshaft and a cap extension direction perpendicular to an attachment direction in which the crank cap is attached to the engine body; and
at least one of the partial mass portions is configured to be supported with respect to the crank cap at a spring constant different from a spring constant of a rest of the partial mass portions in the axial direction of the crankshaft.

16. The crank cap assembly according to claim 15 , wherein a sixth elastic body is provided between the partial mass portions next to each other.

17. The crank cap assembly according to claim 1 , wherein
the elastic supporter is configured so as to elastically support the mass portion at a different spring constant in three directions, the three directions being the axial direction of the crankshaft, an attachment direction in which the crank cap is attached to the engine body, and a cap extension direction, and
the cap extension direction is perpendicular to both the axial direction and the attachment direction.

18. The crank cap assembly according to claim 17 , wherein the elastic supporter is formed such that the spring constant increases in an order of the axial direction, the cap extension direction, and the attachment direction.

19. An internal combustion engine comprising:
a plurality of the crank cap assemblies according to claim 1 ; and
a crankshaft, wherein
the crankshaft is rotatably attached to the engine body by the crank cap assemblies disposed in a row,
a seventh elastic body is provided between the mass portion of the crank cap assembly and the engine body, and
the mass portion is elastically supported on the engine body by the seventh elastic body.

20. An internal combustion engine comprising
a plurality of the crank cap assemblies according to claim 1 , wherein
the crankshaft is rotatably attached to the engine body by the crank cap assemblies disposed in a row, and
the crank cap assembly disposed in a middle portion of the engine body in the axial direction of the crankshaft is configured such that a resonance frequency of the mass portion of the crank cap assembly is higher than resonance frequencies of the mass portions of the crank cap assemblies disposed in both end portions of the engine body in the axial direction of the crankshaft.

Assignees

• Toyota Motor Co Ltd

Inventors

• Ono Tomoyuki

Classifications

• F16C3/22

  Cranks; Eccentrics (constructional features of crank-pins F16C11/02) · CPC title

• F02F2007/0041

  Fixing Bolts · CPC title

• F02F7/0053 Primary

  Crankshaft bearings fitted in the crankcase · CPC title

• F02F7/00 Primary

  Casings, e.g. crankcases · CPC title

• F16F7/108

  on plastics springs · CPC title