Unlock instant, AI-driven research and patent intelligence for your innovation.

Valve timing adjuster

a timing adjuster and valve technology, applied in valve arrangements, machines/engines, mechanical equipment, etc., can solve the problems of difficult supply of working fluid and lower engine phase stability

Inactive Publication Date: 2009-07-16
DENSO CORP
View PDF4 Cites 26 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, it is difficult to supply the working fluid when negative variable torque, which biases the camshaft in the advance direction relative to the crankshaft, acts on the vane rotor, because the negative variable torque increases the volume of the advance chamber, causing the fluid, which has been supplied into the input port, to flow into the advance chamber through the advance output port.
The back flow also lowers the stability of the engine phase when the valve timing adjuster holds the phase fully retarded by pressing the vane against the appropriate shoe.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Valve timing adjuster
  • Valve timing adjuster
  • Valve timing adjuster

Examples

Experimental program
Comparison scheme
Effect test

first embodiment

[0031]FIG. 1 is a schematic diagram of a valve timing adjuster 1 according to a first embodiment of the present invention. The adjuster 1 is applied to an internal combustion engine of a vehicle. The adjuster 1 is a hydraulic valve timing adjuster using hydraulic oil serving as working fluid. The adjuster 1 adjusts valve timing of an intake valve serving as a “valve” of the engine.

[0032]The basic structure of the valve timing adjuster 1 will be described below. The adjuster 1 includes a drive unit 10 and a control unit 30. The drive unit 10 is fitted to a driving force transmission system for transmitting the driving force of a crankshaft (not shown) of the engine to a camshaft 2 of the engine and is driven with hydraulic oil. The control unit 30 controls the supply of hydraulic oil to the drive unit 10.

[0033]The drive unit 10 includes a housing 12 serving as a first rotor (driving rotor), which has a cylindrical sprocket 12a and shoes 12b to 12e as partitions.

[0034]The sprocket 12a...

second embodiment

[0098]As shown in FIG. 10, a second embodiment of the present invention is a modified form of the first embodiment. The control unit 1030 of the second embodiment has a drain line 1082 in addition to the drain line 82. The drain line 1082 opens into the atmosphere, and hydraulic oil can be drained through this line to the oil pan 5.

[0099]The spool valve 1100 of the control unit 1030 has a drain port 1118 in addition to the drain port 118. The drain port 1118 is open to the atmosphere through the drain line 1082, and hydraulic oil is drained through the port 1118 to the line 1082. As shown in FIG. 11, the drain port 1118 is positioned between the retard output port 114 and the sleeve end 110a.

[0100]As shown in FIG. 10, the spool 1130 of the spool valve 1100 has a junction passage 1260 in addition to the junction passage 260. The junction passage 1260 enables the retard output port 114 to communicate with the drain port 1118. As shown in FIG. 11, the junction passage 1260 extends thr...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A valve timing adjuster includes a first rotor, a second rotor, a spool valve, a connection passage, and a connection check valve. A spool of the spool valve is displaceable to a first position such that the first rotor is rotated relative to the second rotor. The spool is displaceable to a second position to hold the phase of a camshaft at a full phase. The connection passage connects a first output port with a second output port of the spool valve when the spool is positioned at the first position. The connection check valve of the connection passage allows working fluid to flow from the second output port toward the first output port.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application is based on and incorporates herein by reference Japanese Patent Application No. 2008-3604 filed on Jan. 10, 2008.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a valve timing adjuster for adjusting a valve of an internal combustion engine, which is opened and closed by a camshaft of the engine through torque transmission from a crankshaft of the engine.[0004]2. Description of Related Art[0005]Hydraulic valve timing adjusters have been used widely, each of which has a housing serving as a driving rotor (first rotor) and a vane rotor serving as a driven rotor (second rotor). The housing rotates synchronously with the crankshaft of an internal combustion engine. The vane rotor rotates synchronously with the camshaft of the engine. JP-A-2006-177344 corresponding to U.S. Pat. No. 7,124,722 discloses a hydraulic valve timing adjuster having a housing and a vane rotor. An advance...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): F01L1/352
CPCF01L1/3442F01L2001/3443F01L2001/34426
Inventor TAKENAKA, AKIHIKO
Owner DENSO CORP