EP-4741643-A1 - ENGINE SYSTEM WITH THERMOSTAT ARRANGEMENT FOR CONTROLLING COOLANT FLOW THROUGH A BYPASS CIRCUIT

EP4741643A1EP 4741643 A1EP4741643 A1EP 4741643A1EP-4741643-A1

Abstract

The present disclosure provides an engine system (10) comprising an engine (11), a primary coolant circuit (9) and a thermostat arrangement (20). A main coolant circuit (12) extends between the engine and a heat exchanger (14) for circulating coolant therebetween. A main bypass circuit (13) directs coolant through the engine whilst bypassing the heat exchanger. The thermostat arrangement is mounted in the primary coolant circuit for controlling coolant flow through the main bypass circuit. The thermostat arrangement is configurable between a first state for enabling coolant flow through the main coolant circuit and through the main bypass circuit and a second state for enabling coolant flow through the main coolant circuit and blocking coolant flow through the main bypass circuit.

Inventors

Felgate, Karl Lesley
Lester, Ben

Assignees

Caterpillar Shrewsbury Limited

Dates

Publication Date: 20260513
Application Date: 20251010

Claims (15)

An engine system comprising: an engine; a primary coolant circuit comprising: a main coolant circuit extending between the engine and a heat exchanger for circulating coolant therebetween; and a main bypass circuit for directing coolant through the engine whilst bypassing the heat exchanger; and a thermostat arrangement mounted in the primary coolant circuit for controlling coolant flow through the main bypass circuit and configurable between: a first state for enabling coolant flow through the main coolant circuit and through the main bypass circuit; and a second state for enabling coolant flow through the main coolant circuit and blocking coolant flow through the main bypass circuit.
The engine system of claim 1 wherein the thermostat arrangement is configured to be in the first state when coolant is below a predetermined temperature and in the second state when the coolant is above the predetermined temperature.
The engine system of claim 1 or claim 2 wherein the main coolant circuit extends from the engine, through the thermostat arrangement and to the heat exchanger.
The engine system of any preceding claim wherein the first state is for directing at least 75% of the coolant flow through the main coolant circuit and less than 25% of the coolant flow through the main bypass circuit.
The engine system of any preceding claim wherein the main bypass circuit comprises a bypass inlet located in the main coolant circuit and the thermostat arrangement is mounted adjacent to the bypass inlet.
The engine system of claim 5 wherein the main coolant circuit is at least partially formed by a main coolant channel extending through the engine, wherein the bypass inlet is located in the main coolant channel.
The engine system of claim 5 or claim 6 wherein the thermostat arrangement comprises a valve configurable between the first state, in which the valve is separated from the bypass inlet for allowing coolant flow through the main bypass circuit via the bypass inlet, and the second state, in which the valve blocks the bypass inlet for blocking coolant flow through the main bypass circuit.
The engine system of any preceding claim wherein the thermostat arrangement comprises a diversion adapter mounted to the engine, the diversion adapter comprising: an external opening for directing coolant to the heat exchanger; at least one diversion aperture for receiving coolant flow in the first and second states; and an adapter channel for directing fluid from the at least one diversion aperture to the external opening.
The engine system of claims 7 and 8 wherein diversion adapter comprises an internal opening and the valve is mounted to the diversion adapter at the internal opening.
The engine system of any one of claims 7 to 9 wherein the valve is configured to selectively allow the flow of coolant through the valve such that in the first state the valve blocks coolant flow through the valve, whilst in the second state the valve allows coolant flow through the valve.
A diversion adapter for the thermostat arrangement of the engine system of any one of the preceding claims, the diversion adapter comprising: a hollow adapter body comprising an adapter channel extending therethrough, the hollow adapter body and adapter channel extending between internal and external openings, the internal opening being for receiving a valve of the thermostat arrangement; and at least one diversion aperture extending through the adapter body configured to enable coolant to flow from external to the diversion adapter, through the at least one diversion aperture and into the adapter channel, bypassing the valve.
A diversion adapter as claimed in claim 11 wherein the adapter channel comprises an internal screw thread adjacent to the internal opening configured to receive the valve.
A diversion adapter as claimed in claim 11 or claim 12 wherein the adapter body comprises: an internal portion comprising the internal opening and configured to be mounted inside an engine of the engine system, wherein the at least one diversion aperture extends through the inner portion; and/or an external portion comprising the external opening and configured to be mounted outside of the engine, wherein the external portion is configured such that at least one conduit of the main coolant circuit can be sealingly mounted to the external portion.
A thermostat arrangement comprising the diversion adapter as claimed in any one of claims 11 to 13 and a valve mounted in the internal opening, wherein the valve is configurable between first and second states, wherein the valve is configured to selectively allow the flow of coolant through the valve such that in the first state the valve is configured to block coolant flow through the valve and in the second state the valve is configured to allow coolant flow through the valve.
A method of operating an engine system, the engine system comprising: an engine; a primary coolant circuit comprising: a main coolant circuit extending between the engine and a heat exchanger for circulating coolant therebetween; and a main bypass circuit extending through the engine for directing coolant through the engine whilst bypassing the heat exchanger; and a thermostat arrangement mounted in the primary coolant circuit for controlling coolant flow through the main bypass circuit, wherein the method comprises operating the thermostat arrangement between: a first state in which coolant flows through the main coolant circuit and through the main bypass circuit; and a second state in which coolant flows through the main coolant circuit and coolant flow through the main bypass circuit is blocked.

Description

Technical Field This disclosure is directed towards an engine system with a thermostat arrangement for controlling coolant flow through a main bypass circuit and a main coolant circuit, a thermostat arrangement for such an engine system, a diversion adapter for such a thermostat arrangement and a method of operating an engine system with the thermostat arrangement. Background Vehicles and machines, including backhoe loaders, excavators, loaders and the like, commonly comprise an engine assembly including an engine, particularly an internal combustion engine, for providing power for driving the machine and operating its components. Engines are typically designed to operate effectively within a range of temperatures and thus a coolant system is typically provided to maintain the engine temperature within such an operational range. During warm up, the coolant system may recirculate coolant through the engine to retain heat therein. Once the engine has reached a sufficient temperature, the coolant system redirects the coolant to a radiator, where the coolant is cooled and returned to the engine for providing cooling to the engine. Thermostat valves are commonly incorporated into the coolant system and switch the coolant flow between recirculation through the engine and circulation to the radiator, based on the coolant temperature. For example, US2023251675A1 discloses a thermostatic device, US11002176B2 discloses a temperature regulator and US11493941 B2 discloses a thermostatic valve. It has been found that the thermostatic valve arrangement is not suitable for all applications. In particular, the coolant system may need to be reconfigured to supply coolant to components requiring it when the engine is at low temperatures, such as by implementing secondary coolant systems with coolant flows controlled separate to the thermostat valves and directed only to those components, without ever passing through the engine. Summary An object of the present disclosure is therefore to provide an engine system with an improved cooling system. A further object of the present disclosure is to provide an engine system with more flexibility when suppling coolant to components other than the engine. The present disclosure therefore provides an engine system, diversion adapter, thermostat arrangement and method in accordance with the claims. In the present disclosure, the engine system comprises an engine, a primary coolant circuit and a thermostat arrangement mounted in the primary coolant circuit. The primary coolant circuit comprises a main coolant circuit and a main bypass circuit and the thermostat arrangement is for controlling coolant flow through the main bypass circuit. The main coolant circuit extends between the engine and a heat exchanger for circulating coolant therebetween. The main bypass circuit may extend at least partially through the engine and is for directing coolant through the engine whilst bypassing the heat exchanger. The thermostat arrangement is configurable between first and second states. In the first state the thermostat arrangement is for enabling coolant flow through the main coolant circuit and through the main bypass circuit. In the second state the thermostat arrangement is for enabling coolant flow through the main coolant circuit and for blocking coolant flow through the main bypass circuit. As a result, the coolant flow is always supplied through the main coolant circuit, such as to at least one cooler therein. This enables components of the engine system to be directly mounted in the main coolant circuit, simplifying the design thereof and reducing the need for complex secondary coolant systems. Yet furthermore, the main coolant circuit can have components located therein that warm up quickly and thus can supply heat to the engine itself whilst the engine is warming up, thereby accelerating overall system warm up. The present disclosure also provides a diversion adapter comprising a hollow adapter body and at least one diversion aperture extending through the adapter body. The adapter body comprises an adapter channel extending therethrough. The hollow adapter body and adapter channel extend between internal and external openings. The internal opening is for receiving a valve of the thermostat arrangement. The at least one diversion aperture is configured to enable coolant to flow from external to the diversion adapter, through the at least one diversion aperture and into the adapter channel, bypassing the valve. The present disclosure further provides a thermostat arrangement comprising the diversion adapter disclosed herein and a valve mounted in the internal opening. The valve is configurable between first and second states. The valve may be configured to selectively allow the flow of coolant through the valve such that in the first state the valve is configured to block coolant flow through the valve and in the second state the valve is configured to allow coolant flow through the valve.