Thermostat for an engine cooling system

Abstract

A thermostat for an engine cooling system is arranged between an engine and a radiator. The thermostat may include: a housing having a coolant inlet through which inflow coolant flows in from the engine and a radiator side outlet; a main valve provided in the housing and coupled to one side of a wax to open and close the radiator side outlet by a change in volume of the wax; and a heating unit coupled to the other side of the wax to supply heat to the wax.

Claims

1. A thermostat for an engine cooling system arranged between an engine and a radiator, the thermostat comprising: a housing having a coolant inlet through which inflow coolant flows in from the engine, a radiator side outlet, and a bypass outlet to circulate the inflow coolant introduced through the coolant inlet to the engine; a main valve supported by a bracket in the housing and coupled to a first side of a wax in the bracket to open and close the radiator side outlet by a change in a volume of the wax; a bypass valve coupled to a second side of the wax in the bracket in the housing to open and close the bypass outlet; and a heating unit including a heater to heat the wax, wherein the heating unit is disposed adjacent to the bypass outlet such that a decrease of a flow rate of the coolant flowing to the radiator side outlet is avoided and a low temperature of the coolant flowing in a peripheral portion is maintained, wherein the heating unit further comprises a connector provided outside the housing and electrically connected to the heater to control the heater, and wherein a first end of the heater is coupled to the second side of the wax and is arranged through the bypass valve and a second end of the heater extends through the housing to the connector, the second end of the heater being further away from the radiator side outlet than the first end of the heater.

2. The thermostat according to claim 1, further comprising a sensor arranged at a side of the coolant inlet to detect a temperature of the inflow coolant.

3. The thermostat according to claim 1, wherein an O-ring is installed between the housing and the connector.

4. The thermostat according to claim 1, wherein the bypass valve provided in the housing is configured to open and close the bypass outlet by the change in the volume of the wax.

5. The thermostat according to claim 1, wherein the heater is press-fit into a through-hole of the housing.

6. The thermostat according to claim 1, wherein the heater is integrally formed with the housing.

7. The thermostat according to claim 1, further comprising a main valve spring to elastically support the main valve in the housing and return the main valve to its original position.

8. The thermostat according to claim 7, further comprising a bypass valve spring to elastically support the bypass valve in the housing and return the bypass valve to its original position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above and other objects, features, and other advantages of the present disclosure will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

(2) FIG. 1 shows an example of an engine cooling system;

(3) FIG. 2 is a graph showing reduction of a flow rate of a coolant in a conventional electronic thermostat; and

(4) FIG. 3 is a schematic view of a thermostat for an engine cooling system according to an embodiment of the present disclosure.

DESCRIPTION OF SPECIFIC EMBODIMENTS

(5) In order to fully understand the present disclosure, operational advantages of the present disclosure, and objects achieved by implementing the present disclosure, one should refer to the accompanying drawings exemplifying embodiments of the present disclosure and contents described in the accompanying drawings.

(6) In describing the embodiments, detailed description of technology known in the art or iterative description may be presented in short or may be omitted to avoid obscuring the subject matter of the present disclosure.

(7) FIG. 3 is a schematic view of a thermostat for an engine cooling system, such as the engine cooling system shown in FIG. 1, according to an embodiment of the present disclosure. Hereinafter, the thermostat for an engine cooling system according to the embodiment of the present disclosure will be described with reference to FIG. 3.

(8) The thermostat 100 according to the embodiment of the present disclosure is arranged in a flow path between an engine (engine head and engine block) and a radiator of an engine cooling system as shown in FIG. 1. The thermostat 100 is configured such that a valve supported by a bracket 160 is operated by a change in the volume of wax 120 in a housing 110 of the thermostat. The valve in turn controls a flow path and a flow rate of the coolant.

(9) The housing 110 is formed with a coolant inlet 111, a bypass outlet 112, and a radiator side outlet 113.

(10) In addition, two valves, i.e., a main valve 131 and a bypass valve 132, are provided to control opening/closing and the flow rate of the radiator side outlet 113 and the bypass outlet 112, respectively.

(11) The main valve 131 is arranged to open and close the radiator side outlet 113. Specifically, the main valve 131 is coupled to one side of the wax 120 in the bracket 160, i.e., a top side of the wax in the figure, so that it moves upward and downward in the figure by a change in the volume of the wax 120. The main valve 131 in turn opens and closes the radiator side outlet 113. After the main valve 131 changes position, the main valve is returned elastically to its original position by means of a main valve spring 151 supported on the bracket 160.

(12) Further, the bypass valve 132 is arranged to open and close the bypass outlet 112. Specifically, the bypass valve 132 is coupled to the other side of the wax 120 in the bracket 160, i.e., a bottom side of the wax in the figure so that it moves upward and downward in the figure by a change in the volume of the wax 120. The bypass valve 132 in turn opens and closes the bypass outlet 112. After the bypass valve 132 changes the position, the bypass valve is returned elastically to its original position by means of a bypass valve spring 152 coupled to the bottom side of the bracket 160.

(13) The thermostat 100 in this embodiment of the present disclosure is an electronic thermostat for controlling circulation of coolant to the bypass outlet 112 and the radiator side outlet 113 in response to operating conditions of the engine, such as load of the engine and environmental factors, by means of the main valve 131 and the bypass valve 132. To this end, the thermostat comprises a heating unit as a heat source for supplying heat to the wax 120.

(14) The heating unit includes a heater 171 and a connector 172. In order to control the heater 171, a sensor 140 for detecting a temperature of the coolant is arranged at the coolant inlet 111 side.

(15) Further, in this embodiment of the present disclosure, the heater 171 is coupled to the other side of the wax 171, i.e., the bottom side of the wax in the figure, rather than the radiator side outlet 113 that is the top side of the main valve 131, as in the conventional thermostat, and arranged through the bypass valve 132 and the housing 110.

(16) In addition, the connector 172 provided outside the housing 110 is electrically connected to the heater 171 to control the heater 171. An O-ring 173 is provided between the housing 110 and the connector 172 as viewed in the section through the housing 110.

(17) The heater 171 may be press-fit into a through-hole of the housing 110 without the O-ring 173. In addition, the heater may be integrally formed with the housing 110.

(18) Consequently, in the embodiment of the present disclosure, the heater 171 does not decrease the flow rate of the coolant flowing to the radiator side outlet 113. In addition, since the heater is arranged at the bypass outlet 112 side, and thus the temperature of the coolant in the peripheral portion is low, it is advantageous in terms of temperature, sealing performance, and vibration. The reason for not decreasing the flow rate of the coolant is that the heater does not generate flow resistance.

(19) Moreover, since the length of the heater 171 can be shortened compared to the conventional heater, it is simpler and more stable in terms of structure.

(20) On the other hand, the bypass flow path (or bypass line) may not be required in the engine cooling system. In such a case, the thermostat according to embodiments of the present disclosure can be configured such that a bypass valve, a bypass valve spring, and a bypass outlet are omitted. In this case, the heater can be configured to be coupled to the connector outside the housing without the bypass valve, the bypass valve spring, and the bypass outlet.

(21) Although the present disclosure has been described above with reference to the drawings illustrated by way of an example, the present disclosure is not limited to the disclosed embodiments. It should be apparent to those of ordinary skill in the art that various modifications and variations can be made to the present disclosure without departing from the spirit and scope of the disclosure. Therefore, such modifications or variations fall within the scope of the present disclosure as claimed and the scope of the present disclosure should be interpreted based on the appended claims.