Integration of a thermostat in the recycling system of the vehicular exhaust gas recirculation (EGR) system

• US 20050145228A1
• Filed: 12/29/2003
• Published: 07/07/2005
• Est. Priority Date: 12/29/2003
• Status: Active Grant

• Current Assignee: Wahler Metalurgica Limiteda
• Original Assignee: Wahler Metalurgica Limiteda
• Inventors: Ieda, Joao Jose Cardinali
• Granted Patent: US 7,108,193 B2
• Time in Patent Office: Days
• US Class Current: 123/568.120
• CPC Class Codes: F02M 26/32 Liquid-cooled heat exchangers
• CPC Class Codes: F02M 26/33 controlling the temperature of the recirculated gases
• CPC Class Codes: Y10T 137/7737 Thermal responsive

Abstract

The invention relates to the control of the temperature of recirculated exhaust gas and oil, by means of the placement of a thermostat between an oil/water heat exchanger and a water/exhaust gas exchanger. The thermostat comprises a multifaceted casing (1), in which there is a tubular portion (2) having access to a chamber (7); and, at the bottom of the chamber (7), there is a smaller diameter by-pass passage (11), through which the chamber is linked to a connection duct (12) having access to the output channel (13) that is projected along the tubular projection (14), wherein the thermostatic valve is integrated to the casing (1) by being placed inside the chamber (7), along the tubular portion (2).

Claims

1. A thermostat assembly for integration in an exhaust gas recirculating system of a vehicle comprising:

a casing having a multifaceted body having a tubular portion which defines a thermostatic valve housing, a nozzle for fixing a closing/sealing terminal having a central projection containing a centered blind hole, the tubular portion providing access to a chamber having a ring wall supporting a shaped flange having holes for receiving screws therein, a smaller diameter by-pass passage located at a bottom of the chamber and aligned with a central axis of the tubular portion for linking the chamber to a connection duct for providing access to a coolant output channel projected along a tubular projection, a cylinder shaped central projection located at a bottom of the smaller diameter bypass passage having a tip having a blind hole.

2. The thermostat assembly of claim 1 wherein the thermostatic valve is placed inside the chamber, along the tubular portion with the lesser diameter cylindrical extension inserted in the centered blind hole, the center pin inserted in the tip blind hole, the thermostatic valve biased by a spring.

3. The thermostat assembly of claim 1 wherein the nozzle of the tubular portion is fixed by a snap ring or pressed ring to a cylindrical terminal having a groove for receiving a sealing ring therein.

4. The thermostat assembly of claim 1 wherein the lesser diameter extension is supported on a conical spring.

5. The thermostat assembly of claim 1 wherein the thermostat has a hollow body having an inlet nozzle having a groove for receiving a sealing ring, two shaped legs projecting perpendicularly from a bottom of the cavity, the legs arranged on two diametrically opposing sides to form a rabbet to support a supporting arch of the thermostatic valve, the cavity defining a chamber for receiving the thermostatic valve, a convex elevation having an inner central opening having a conical or radial edge for supporting a blockage area of the thermostatic valve, a wall provided between the body'"'"'s cavity and the convex elevation having a central opening having a conical or radial edge for supporting a blockage area of the thermostatic valve, a flange located above the circular body having holes for receiving fixing screws, an outlet tubular extension projected from the convex elevation having a channel linked to an interior of the convex elevation.

6. The thermostat assembly of claim 1 wherein the thermostat has a tubular extension for diverting to a hollow circular body provided with a half spherical shaped elevation having a cylindrical projection in an interior thereof, and having a blind hole in a tip thereof to center the thermostatic valve, the hollow circular body having an extension and an inlet nozzle with a groove to receive a sealing ring, a declivity projected at the nozzle for forming a rabbet to support a supporting arch of the thermostatic valve, wherein a central pin is inserted in the blind hole, a wall between the body'"'"'s cavity and the half spherical shaped elevation having an opening having a conical or radial edge for supporting a blockage area of the thermostatic valve, a flange around the extension having holes for receiving fixing screws therein.

7. The thermostat assembly of claim 1 wherein the closing/sealing terminal is fixed to the thermostatic valve housing by a structure selected from the group consisting of threads, a snap ring, a pressed ring, an elastic ring with joint sealant or by re-spiking.

8. A thermostat assembly system for cooling an exhaust gas for a vehicle exhaust gas recirculation system comprising:

an engine oil cooler having means for receiving cooling water therein for cooling engine oil and means to discharging the cooling water;

a thermostat assembly having means for receiving the cooling water discharged form the engine oil cooler, and having a thermostatic valve therein for controlling the water flow there through in response to a temperature thereof and having means for discharging the cooling water therefrom;

a recirculation exhaust gas cooler for receiving the cooling water discharged from the thermostat assembly when the thermostat valve is opened, such that the engine oil and the recirculated exhaust gas are cooled when the engine has reached a thermostatic valve opening temperature.