Valve timing adjustment device

Patent metadata

Field	Value
Publication number	US-10858965-B2
Application number	US-201916502333-A
Country	US
Kind code	B2
Filing date	Jul 3, 2019
Priority date	Jan 19, 2017
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

A retard supply passage connects between a hydraulic oil supply source and a retard chamber through a hydraulic oil controller. An advance supply passage connects between the hydraulic oil supply source and an advance chamber through the hydraulic oil controller. A drain passage and a drain passage connect the retard chamber and the advance chamber to an oil discharge portion, respectively. A recycle passage connects the drain passage and the drain passage to the retard supply passage and the advance supply passage, respectively. A recycle check valve enables only a flow of hydraulic oil from the drain passages toward the retard supply passage and the advance supply passage in the recycle passage. The recycle passage is connected to the drain passages at an inside of the hydraulic oil controller.

First claim

What is claimed is:

1. A valve timing adjustment device configured to adjust a valve timing of a valve of an internal combustion engine, the valve timing adjustment device comprising:
a phase converter that has a retard chamber and an advance chamber;
a hydraulic oil supply source that is configured to supply hydraulic oil to the retard chamber and the advance chamber;
a hydraulic oil controller that is configured to control the hydraulic oil supplied from the hydraulic oil supply source to the retard chamber and the advance chamber;
an oil discharge portion that is configured to receive the hydraulic oil discharged from the retard chamber or the advance chamber;
a retard supply passage that connects between the hydraulic oil supply source and the retard chamber through the hydraulic oil controller;
an advance supply passage that connects between the hydraulic oil supply source and the advance chamber through the hydraulic oil controller;
a drain passage that connects the retard chamber and the advance chamber to the oil discharge portion;
a recycle passage that connects the drain passage to the retard supply passage and the advance supply passage; and
a recycle check valve that enables only a flow of the hydraulic oil from the drain passage toward the retard supply passage and the advance supply passage in the recycle passage and limits a flow of the hydraulic oil from the retard supply passage and the advance supply passage toward the drain passage in the recycle passage, wherein:
the recycle passage is connected to the drain passage at an inside of the hydraulic oil controller; and
the hydraulic oil controller includes:
a sleeve that is shaped in a tubular form and holds the recycle check valve, wherein a portion of the retard supply passage and a portion of the advance supply passage radially extend through a peripheral wall of the sleeve; and
a spool that is placed in an inside of the sleeve and is configured to reciprocate relative to the sleeve and the recycle check valve in an axial direction of the spool.

2. The valve timing adjustment device according to claim 1 , wherein:
the spool is shaped in a tubular form and forms a specific space between the spool and the sleeve;
the hydraulic oil controller further includes:
a drain opening that is connected to the specific space in the drain passage and extends from the specific space in a radial direction of the sleeve or the spool; and
a recycle opening that is connected to the specific space in the recycle passage and extends from the specific space toward a side that is opposite to the drain opening; and

the recycle passage is connected to the drain passage in the specific space.

3. The valve timing adjustment device according to claim 2 , wherein at least a portion of the drain opening overlaps with the recycle opening in an axial direction of the sleeve or the spool.

4. The valve timing adjustment device according to claim 2 , wherein:
the drain opening is formed at the spool such that the drain opening inwardly extends from the specific space in the radial direction of the sleeve or the spool; and
the recycle opening is formed at the sleeve such that the recycle opening outwardly extends from the specific space in the radial direction of the sleeve or the spool.

5. The valve timing adjustment device according to claim 2 , wherein:
the spool includes:
a retard supply recess that is radially inwardly recessed from an outer peripheral wall of the spool and forms a portion of the retard supply passage;
a retard drain recess that is radially inwardly recessed from the outer peripheral wall of the spool and forms a portion of the drain passage that communicates the retard chamber to the oil discharge portion;
an advance drain recess that is radially inwardly recessed from the outer peripheral wall of the spool and forms a portion of the drain passage that communicates the advance chamber to the oil discharge portion; and
an advance supply recess that is radially inwardly recessed from the outer peripheral wall of the spool and forms a portion of the advance supply passage;

the retard supply recess, the retard drain recess, the advance drain recess and the advance supply recess are arranged one after another in this order in an axial direction of the spool;
the retard drain recess and the advance drain recess are formed integrally and form the specific space, and
the recycle check valve is placed to correspond with the recycle opening.

6. The valve timing adjustment device according to claim 2 , wherein the sleeve includes an axial supply passage that extends in an axial direction of the sleeve in the retard supply passage and the advance supply passage.

7. The valve timing adjustment device according to claim 6 , wherein the recycle passage connects between the drain passage and the axial supply passage.

8. The valve timing adjustment device according to claim 6 , wherein:
the sleeve includes:
an outer sleeve; and
an inner sleeve that is placed at an inside of the outer sleeve, and

the axial supply passage is located at an interface between the outer sleeve and the inner sleeve.

9. The valve timing adjustment device according to claim 8 , wherein:
one of an inner peripheral wall of the outer sleeve and an outer peripheral wall of the inner sleeve is shaped in a cylindrical form; and
a passage groove, which forms the axial supply passage, is formed at another one of the inner peripheral wall of the outer sleeve and the outer peripheral wall of the inner sleeve.

10. The valve timing adjustment device according to claim 8 , wherein the inner sleeve includes:
a first inner sleeve; and
a second inner sleeve that is placed at an inside of the first inner sleeve, wherein the second inner sleeve has a hardness, which is higher than a hardness of the first inner sleeve.

11. The valve timing adjustment device according to claim 8 , wherein a hardness of the outer sleeve is higher than a hardness of a portion of the inner sleeve while the hardness of the portion of the inner sleeve is a lowest hardness in the inner sleeve.

12. The valve timing adjustment device according to claim 1 , wherein the recycle check valve is resiliently deformable in a radial direction.

13. The valve timing adjustment device according to claim 12 , wherein the sleeve includes a movement limiting portion that is configured to limit movement of the recycle check valve in an axial direction.

14. The valve timing adjustment device according to claim 1 , further comprising a sleeve sealing portion that closes one end of the sleeve and forms a variable volume space between the sleeve sealing portion and the spool while a volume of the variable volume space is variable, wherein the variable volume space is communicated with the drain passage.

15. The valve timing adjustment device according to claim 1 , further comprising a housing that forms the retard chamber and the advance chamber, wherein at least a portion of the hydraulic oil controller is placed at an inside of the housing.

Assignees

• Denso Corp

Inventors

• Mitsutani Tetsuro

Classifications

• F01L2250/04

  the camshaft being driven by belts · CPC title

• F01L2250/02

  the camshaft being driven by chains · CPC title

• F01L2001/3444

  Oil filters · CPC title

• F01L2001/0476

  Camshaft bearings · CPC title

• F01L2301/00

  Using particular materials · CPC title