US 6,453,859 B1 · Multi-mode control system for variable camshaft timing devices

Abstract

A variable camshaft timing apparatus (10) includes a pulse actuating circuit (24A,50,44,56,60,24R and 24R,52,46,54,58,24A) for oscillating the variable camshaft timing apparatus in reaction to fluid under pulsation, and includes a pressure actuating circuit (30,34,36,40,44,50,24A,24R,52,46,66,80/180,32 and 30,34,38,42,46,52,24R,24A,50,44,64,80/180,32) for oscillating the variable camshaft timing device in reaction to fluid under pressure. Advance and retard valves (44,46) are interconnected with the pulse and pressure actuating circuits for independently and simultaneously activating the pulse and pressure actuating circuits. Finally, an exhaust valve (80,180, 280) is positioned in fluid communication with the pulse and pressure actuating circuits, such that the variable camshaft timing device may be oscillated using one or both of the pulse actuating and pressure actuating circuits, and may be maintained in position using one or both of the pulse actuating and pressure actuating circuits.

Claims18

Dependent claims

A variable camshaft timing apparatus comprising:

pulse actuating means for oscillating said variable camshaft timing device in reaction to fluid under pulsation;
pressure actuating means for oscillating said variable camshaft timing device in reaction to fluid under pressure;
and
switching means for independently and simultaneously activating said pulse actuating means and said pressure actuating means;
whereby said variable camshaft timing device may be oscillated using one or both of said pulse actuating means and said pressure actuating means, and said variable camshaft timing device may be maintained anywhere in position between a fully advanced and a fully retarded condition, using one or both of said pulse actuating means and said pressure actuating means.

2 more elements

A control system for a variable camshaft timing apparatus connected to a fluid pressure source (30), said control system comprising:

an advance chamber (24A);
a retard chamber(24R);
a pulse actuating means for oscillating said variable camshaft timing apparatus, said pulse actuating means interconnecting said advance and retard chambers, wherein said pulse actuating means comprises:
a retarding pulse means (50,44,56) for conveying fluid under pulsation from said advance chamber to said retard chamber, said retarding pulse means including means (60) for preventing counterflow from said retard chamber;
and
an advancing pulse means (52,46,54) for conveying fluid under pulsation from said retard chamber to said advance chamber, said advancing pulse means including means (58) for preventing counterflow from said advance chamber;
a pressure actuating means for oscillating said variable camshaft timing apparatus, said pressure actuating means comprising:
a retarding pressure supply means (34,46,52) for supplying fluid from said fluid pressure source to said retard chamber;
a retarding pressure exhaust means (50,44,64,180,32) for exhausting fluid from said advance chamber back to said fluid pressure source;
an advancing pressure supply means (34,44,50) for supplying fluid from said fluid pressure source to said advance chamber;
an advance pressure exhaust means (52,46,66,180, 32) for exhausting fluid from said retard chamber back to said fluid pressure source;
and
means (40, 42) for preventing counterflow from said advance and retard chambers back to said fluid pressure source.

10 more elements

A variable camshaft timing apparatus attached to a camshaft (26), said variable camshaft timing apparatus comprising:

a hub (16) attached to said camshaft and being rotatable but not oscillatable with respect to said camshaft;
a housing (12) circumscribing said hub to define at least one fluid chamber (24) therebetween, said housing being rotatable and oscillatable with respect to said camshaft;
said hub having at least one vane member (22) dividing said at least one fluid chamber into at least one advance chamber (24A) and at least one retard chamber (24R);
a fluid pressure source (30) in fluid communication with said at least one advance and retard chambers, said fluid pressure source having a inlet side (30I) and an outlet side (30O) opposite said inlet side;
a fluid supply passage (34) in fluid communication with said outlet side of said fluid pressure source, said fluid supply passage having at least one check valve (40, 42) for preventing counterflow of fluid back to said fluid pressure source;
an advance valve (44) having a supply port (44S) in fluid communication with said fluid supply passage, said advance valve further having a control port (44C) communicable with said supply port, said advance valve further having an exhaust port (44E) communicable with said control port;
an advance chamber passage (50) having one end in fluid communication with said control port of said advance valve and having an opposite end in fluid communication with said at least one advance chamber;
a retard valve (46) having a supply port (46S) in fluid communication with said fluid supply passage, said retard valve further having a control port (44C) communicable with said supply port, and an exhaust port (44E) communicable with said control port;
a retard chamber passage (52) having one end in fluid communication with said control port of said retard valve and having an opposite end in fluid communication with said at least one retard chamber;
a retard pulse passage (56) having one end in fluid communication with said exhaust port of said advance valve and having an opposite end in fluid communication with said at least one retard chamber, said retard pulse passage having a check valve (60) therein for permitting flow from said at least one advance chamber and for preventing flow from said at least one retard chamber;
an advancing pulse passage (54) having one end in fluid communication with said exhaust port of said retard valve and having an opposite end in fluid communication with said at least one advance chamber, said advancing pulse passage having a check valve (58) therein for permitting flow to said at least one advance chamber and for preventing flow from said at least one advance chamber;
a retard exhaust passage (64) having one end in fluid communication with said exhaust port of said advance valve, said retard exhaust passage terminating in an opposite end;
an advancing exhaust passage (66) having one end in fluid communication with said exhaust port of said retard valve, said advancing exhaust passage terminating in an opposite end;
an exhaust valve (80,180) in fluid communication with said opposite ends of said retard and advancing exhaust passages for exhausting flow from said at least one advance chamber during fluid pressure actuated retarding of said variable camshaft timing device and for exhausting flow from said at least one retard chamber during fluid pressure actuated advancing of said variable camshaft timing device;
and
a sump (32) in fluid communication with said exhaust valve and said inlet side of said fluid pressure source and being interposed therebetween;
said hub being oscillatable with respect to said housing in response to fluid pulsations from one of said at least one advance and retard chambers to other of said at least one advance and retard chambers;
said hub being oscillatable with respect to said housing in response to fluid pressure from said fluid pressure source to one of said at least one advance and retard chambers;
and
said hub being maintainable in position with respect to said housing in response to fluid pressure from said fluid pressure source to both of said at least one advance and retard chambers.

17 more elements

A variable camshaft timing apparatus attached to a camshaft (26), said variable camshaft timing apparatus comprising:

a hub (16) attached to said camshaft and being rotatable but not oscillatable with respect to said camshaft;
a housing (12) circumscribing said hub to define at least one fluid chamber (24) therebetween, said housing being rotatable and oscillatable with respect to said camshaft;
said hub having at least one vane member (22) dividing said at least one fluid chamber (24A) into at least one advance chamber and at least one retard chamber (24R);
a fluid pressure source (130) in fluid communication with said at least one advance and retard chambers, said fluid pressure source having a inlet side (130I) and an outlet side (130O) opposite said inlet side;
a fluid supply passage (134) in fluid communication with said outlet side of said fluid pressure source, said fluid supply passage having at least one check valve (140 or 142) for preventing counterflow of fluid back to said fluid pressure source;
a spool valve (145) having a supply port (145S) in fluid communication with said fluid supply passage, said spool valve further having a retard exhaust port (145R), and an advance exhaust port (145A);
an advance chamber passage (150) having one end in fluid communication with said advance exhaust port of said spool valve and having an opposite end in fluid communication with said at least one advance chamber;
a retard chamber passage (152) having one end in fluid communication with said retard exhaust port of said spool valve and having an opposite end in fluid communication with said at least one retard chamber;
a retard pulse passage (156) having one end in fluid communication with said supply port of said spool valve and having an opposite end in fluid communication with said at least one retard chamber, said retard pulse passage having a check valve (160) therein for permitting flow from said at least one advance chamber and for preventing flow from said at least one retard chamber;
an advance pulse passage (154) having one end in fluid communication with said supply port of said spool valve and having an opposite end in fluid communication with said at least one advance chamber, said advance pulse passage having a check valve (158) therein for permitting flow to said at least one advance chamber and for preventing flow from said at least one advance chamber;
an exhaust valve (180) in fluid communication with said advance and retard exhaust ports of said spool valve, said exhaust valve for exhausting flow from said at least one advance chamber during fluid pressure actuated retarding of said variable camshaft timing device and for exhausting flow from said at least one retard chamber during fluid pressure actuated advancing of said variable camshaft timing device;
and
a sump (132) in fluid communication with said exhaust valve and said inlet side of said fluid pressure source and being interposed therebetween;
said hub being oscillatable with respect to said housing in response to fluid pulsations from one of said at least one advance and retard chambers to other of said at least one advance and retard chambers;
said hub being oscillatable with respect to said housing in response to fluid pressure from said fluid pressure source to one of said at least one advance and retard chambers;
and
said hub being maintainable in position with respect to said housing in response to fluid pressure from said fluid pressure source to both of said at least one advance and retard chambers.

14 more elements

Dependencies are inferred from the claim text.

Multi-mode control system for variable camshaft timing devices

Life of this patent

Multi-mode control system for variable camshaft timing devices

Life of this patent

Abstract

Claims18