JP2017160826A - Cooling device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device for an engine capable of suppressing deterioration of detection accuracy of a temperature of cooling water immediately after it passes through the engine, even if a thermostat and an on-off valve are in the closed state.SOLUTION: A cooling device for an engine includes: a first path in which cooling water is circulated from a water pump to the engine, a radiator and a thermostat in this order; a second path in which cooling water is circulated from the water pump to the engine, an on-off valve, a heater core and the thermostat in this order and which is merged with part of the first path in the engine and branched from the first path in the engine; and a water temperature sensor having a temperature sensing part for detecting a temperature of the cooling water. The second path includes: a heater core path communicated with the heater core from the engine; a return path communicated with the thermostat from the heater core; and a bypass path communicating the heater core path with the return path and bypassing the heater core. The temperature sensing part is located in a section from an inlet of the heater core path through an inlet of the bypass path to an outlet of the bypass path.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an engine cooling apparatus.

  As a cooling device for the engine, the cooling water circulates in the order of the engine, the opening / closing valve, the heater core, and the thermostat from the water pump in the first path through which the cooling water circulates in the order from the water pump to the engine, the radiator, and the thermostat. One having a second path that joins the first path is known. In such a cooling device, a water temperature sensor is provided at a position immediately after the downstream side of the engine and before the first and second paths branch (for example, see Patent Document 1). Thereby, the temperature of the cooling water immediately after passing through the engine can be detected, and for example, whether or not the engine needs to be warmed up can be determined.

Japanese Patent Laying-Open No. 2015-209792

  For example, in order to warm up the engine, the on-off valve on the upstream side of the heater core may be closed to suppress the heat radiation of the cooling water in the heater core. When the thermostat is also closed when the on-off valve is closed in this way, the circulation of the cooling water is stagnated in both the first and second paths, and the cooling water around the water temperature sensor is also stagnant and immediately after passing the engine. There is a possibility that the detection accuracy of the temperature of the cooling water will be lowered.

  Accordingly, an object of the present invention is to provide an engine cooling device in which a decrease in the accuracy of detecting the temperature of cooling water immediately after passing through the engine is suppressed even when the thermostat and the on-off valve are closed.

  The object is to provide a first path through which cooling water circulates from the water pump in the order of the engine, radiator, and thermostat, and from the water pump, cooling water circulates in the order of the engine, the on-off valve, the heater core, and the thermostat. A second path branched from the first path within the engine and a water temperature sensor having a temperature sensing unit for detecting the temperature of the cooling water, The second path includes a heater core path communicating from the engine to the heater core, a return path communicating from the heater core to the thermostat, and a bypass path communicating the heater core path and the return path to bypass the heater core. And the temperature sensing part is connected to the bypass from the inlet of the heater core path through the inlet of the bypass path. Are located in the interval to the outlet of the scan path can be achieved by the cooling system for an engine.

  With the above configuration, even when both the on-off valve and the thermostat are closed, as long as the water pump is driven, the cooling water circulates through the bypass path of the second path and bypasses at least from the inlet of the heater core path. The cooling water flows in the section from the path entrance to the bypass path exit. Thus, by positioning the temperature sensing part of the water temperature sensor in the section where the cooling water flows even when the on-off valve and the thermostat are closed, a decrease in the detection accuracy of the temperature of the cooling water immediately after passing through the engine is suppressed. ing. Even when only the on-off valve is closed, the cooling water flows from the inlet of the heater core path to the outlet of the bypass path at least from the inlet of the heater core path, as in the case where both the on-off valve and the thermostat are closed. The cooling water flows in the section. For this reason, even if only the on-off valve is in a closed state, a decrease in the detection accuracy of the temperature of the cooling water immediately after passing through the engine is suppressed.

  The heater core path includes a first outlet pipe attached to the engine, and the return path includes a return pipe attached to the engine and a flow path formed in the engine in communication with the return pipe. A second outlet pipe that communicates with the flow path and is attached to the engine, and the bypass path includes a bypass pipe that communicates the first outlet pipe and the return pipe. The configuration may be such that the outlet pipe and the return pipe are attached to the cylinder head of the engine.

  ADVANTAGE OF THE INVENTION According to this invention, even if a thermostat and an on-off valve are a closed state, the engine cooling device by which the fall of the detection accuracy of the temperature of the cooling water immediately after passing an engine was suppressed can be provided.

FIG. 1 is a schematic configuration diagram of an engine cooling apparatus according to the present embodiment. FIG. 2 is an enlarged view of the outlet portion. 3A and 3B are enlarged views of the outlet portion in the first and second modifications, respectively. It is. FIG. 4 is a schematic configuration diagram of a cooling device according to another embodiment.

  FIG. 1 is a schematic configuration diagram of an engine cooling device 1 (hereinafter referred to as a cooling device) according to the present embodiment. The cooling device 1 includes an ECU (Electronic Control Unit) 3, a radiator 20, a thermostat 30, a water pump 40, an outlet 50, an on-off valve 60, a heater core 70, and the like. In the cooling device 1, paths Wa and Wb through which the cooling water circulates are provided. When the water pump 40 is driven, the cooling water circulates through the paths Wa and Wb. The water pump 40 may be a mechanical type driven by the driving force of the engine 10 or may be an electric type driven by the supply of electric power controlled by the ECU 3.

  First, the route Wa will be described. The path Wa is an example of a first path through which cooling water circulates in order from the water pump 40 to the engine 10, the radiator 20, and the thermostat 30. Specifically, the cooling water is discharged from the water pump 40 and flows through the water jackets 11w and 13w formed in the cylinder block 11 and the cylinder head 13 of the engine 10, respectively.

  On the downstream side of the water jacket 13w, the branch channels 13wa and 13wb branch, and the branch channels 13wa and 13wb communicate with the radiator 20 and the heater core 70, respectively. The branch flow paths 13wa and 13wb are included in the paths Wa and Wb, respectively.

  The cooling water that has passed through the branch flow path 13wa is discharged from the outlet pipe 15 attached to the cylinder head 13, and flows from the outlet pipe 15 to the radiator 20 through the path 1w. The cooling water is cooled by heat exchange with the outside air by the radiator 20. The cooling water that has passed through the radiator 20 flows to the thermostat 30 via the path 2w. The cooling water flowing through the thermostat 30 in the path Wa returns to the water pump 40 and circulates in the path Wa when the thermostat 30 is open. The thermostat 30 will be described later in detail.

  Next, the route Wb will be described. The path Wb is an example of a second path through which cooling water circulates from the water pump 40 to the engine 10, the on-off valve 60, the heater core 70, and the thermostat 30 in this order. Specifically, in the path Wb, the cooling water circulates from the water pump 40 in the order of the engine 10, the on-off valve 60, the heater core 70, the engine 10, and the thermostat 30. In the paths Wa and Wb, the thermostat 30, the water pump 40, and the water jackets 11w and 13w are shared.

  A part of the cooling water that has passed through the branch flow path 13wb flows from the outlet pipe 51 of the outlet portion 50 to the heater core 70 via the path 5w as long as the later-described on-off valve 60 is open. It flows to the bypass pipe 55 of the section 50. The outlet part 50 and the bypass pipe 55 will be described in detail later.

  The cooling water that has flowed into the heater core 70 is cooled by heat exchange with the air blown into the vehicle compartment in the heater core 70. Accordingly, the outlet pipe 51 and the path 5w are an example of a heater core path communicating from the engine 10 to the heater core 70. The outlet pipe 51 is provided with a water temperature sensor S, which will be described in detail later. The on-off valve 60 is provided on the upstream side of the heater core 70 in the path 5w, and the flow rate of the cooling water passing through the heater core 70 is adjusted by the opening degree of the ECU 3 being controlled.

  The cooling water that has passed through the heater core 70 flows into the flow path 14w formed in the cylinder head 13 via the path 6w and the return pipe 53 of the outlet portion 50. The flow path 14w is not in direct communication with the water jacket 13w. The cooling water that has passed through the flow path 14 w flows to the thermostat 30 through the outlet pipe 17 attached to the cylinder head 13 and the path 7 w connected to the outlet pipe 17.

  Therefore, the path 6 w, the return pipe 53, the flow path 14 w, the outlet pipe 17, and the path 7 w are examples of a return path that communicates from the heater core 70 to the thermostat 30. The outlet pipe 51 is an example of a first outlet pipe attached to the engine 10, and the outlet pipe 17 is an example of a second outlet pipe attached to the engine 10 in communication with the flow path 14 w.

  The cooling water flowing to the thermostat 30 in the path Wb flows to the engine 10 side regardless of whether the thermostat 30 is opened or closed. In this way, the path Wb bypasses the radiator 20 and communicates with the heater core 70. Further, in the paths Wa and Wb, the thermostat 30, the water pump 40, and the water jackets 11w and 13w join together.

  Next, the thermostat 30 will be described. The thermostat 30 is a wax type thermostat that opens and closes according to the temperature of the cooling water. Specifically, the thermostat 30 is operated by the expansion and contraction of a thermo wax (such as paraffin wax) in the heat sensitive part.

  When the temperature of the cooling water in the thermostat 30 is lower than a predetermined valve opening temperature, the thermostat 30 is closed. Thereby, the cooling water in the path Wa is blocked by the thermostat 30 and does not circulate, but the cooling water circulates through the thermostat 30 in the path Wb. For this reason, the cooling water cooled by the radiator 20 does not flow through the engine 10, but the high-temperature cooling water bypassing the radiator 20 flows again into the engine 10 and the engine 10 is warmed up.

  When the temperature of the cooling water in the thermostat 30 is equal to or higher than the valve opening temperature, the thermostat 30 is opened. Thereby, the cooling water circulates in both the paths Wa and Wb. Since the opening degree of the thermostat 30 is adjusted according to the temperature of the cooling water, the mixing ratio of the cooling water in the paths Wa and Wb is adjusted, and the engine 10 is kept at an appropriate temperature.

  Next, the outlet unit 50 will be described. The outlet unit 50 includes an outlet pipe 51 and a return pipe 53 attached to the side surface of the cylinder head 13, and a bypass pipe 55 communicating with the outlet pipe 51 and the return pipe 53. The outlet unit 50 is attached to the engine 10 in order to allow cooling water to flow from the engine 10 to the heater core 70 and return from the heater core 70 into the engine 10. The bypass pipe 55 communicates with the outlet pipe 51 and the return pipe 53 and bypasses the heater core 70. For this reason, the bypass pipe 55 is an example of a bypass path that communicates with the heater core path and the return path and bypasses the heater core 70.

  Here, the outlet pipe 51 and the return pipe 53 are both attached to the cylinder head 13, and the outlet pipe 51 and the return pipe 53 are adjacent to each other. For this reason, the enlargement of the outlet part 50 is suppressed. Further, the outlet pipe 51, the return pipe 53, and the bypass pipe 55 are integrally formed, and workability when the outlet portion 50 is attached to the engine 10 is improved.

  The path from the heater core 70 to the thermostat 30 includes a flow path 14w formed in the engine 10. In this way, the length of the path 6w and the path 7w is suppressed by using the flow path 14w formed in the engine 10. The flow path 14w is formed not in the cylinder block 11 but in the cylinder head 13. For this reason, compared with the case where the flow path 14w is formed over the cylinder block 11 from the cylinder head 13, it is suppressed that the structure in the engine 10 becomes complicated. This description is not intended to exclude the configuration in which the flow path 14w is formed from the cylinder head 13 to the cylinder block 11. When the flow path 14 w is formed from the cylinder head 13 to the cylinder block 11, the outlet pipe 17 is attached to the cylinder block 11.

  Next, the water temperature sensor S will be described. As described above, the water temperature sensor S is provided in the outlet pipe 51 of the outlet unit 50. The water temperature sensor S detects the temperature of the cooling water flowing through the outlet pipe 51 and outputs it to the ECU 3. The ECU 3 controls various devices according to detection values from the water temperature sensor S and outputs from various other sensors. For example, when the detected value of the water temperature sensor S is lower than a predetermined temperature, the ECU 3 determines that the engine 10 is in a cold state, and the ECU 3 closes the on-off valve 60 to release heat from the cooling water in the heater core 70. And the engine 10 is warmed up.

  Next, details of the outlet unit 50 will be described. FIG. 2 is an enlarged view of the outlet unit 50. The paths 5w and 6w are omitted. The outlet pipe 51 has an inlet 51a connected to the branch flow path 13wa on the cylinder head 13 side and an outlet 51b connected to the path 6w. The inlet 51a of the outlet pipe 51 is an example of the inlet of the heater core path. The return pipe 53 has an inlet 53a connected to the path 6w and an outlet 53b connected to the flow path 14w on the cylinder head 13 side. The bypass pipe 55 has an inlet 55 a connected to the outlet pipe 51 and an outlet 55 b connected to the return pipe 53. The inlet 55a and outlet 55b of the bypass pipe 55 are examples of the inlet and outlet of the bypass path, respectively.

  Next, the position of the water temperature sensor S will be described. The water temperature sensor S is provided with a temperature sensing portion Sa for detecting the temperature of the cooling water at the tip. The temperature sensing part Sa is located in the outlet pipe 51 and faces the inlet 55a of the bypass pipe 55.

  Next, circulation of the cooling water in the outlet part 50 when both the thermostat 30 and the on-off valve 60 are closed will be described. Since the bypass pipe 55 is provided in the present embodiment, the cooling water is routed through the bypass pipe 55 as long as the water pump 40 is driven even when both the thermostat 30 and the on-off valve 60 are closed. Circulate Wb.

  FIG. 2 shows the flow direction of the cooling water when the thermostat 30 and the on-off valve 60 are closed and the cooling water circulates in the path Wb. In FIG. 2, a section G from the inlet 51 a of the outlet portion 50 to the outlet 55 b of the bypass pipe 55 through the inlet 55 a of the bypass pipe 55 is indicated by hatching. In FIG. 2, a typical flow direction of the cooling water in the section G is indicated by an arrow F.

  When the thermostat 30 and the on-off valve 60 are in the closed state, from the paths 5w and 6w, the section from the inlet 55a of the bypass pipe 55 to the outlet 51b of the outlet pipe 51 in the outlet pipe 51, and the inlet 53a in the return pipe 53 In the section up to the outlet 55b of the bypass pipe 55, the cooling water hardly flows. This is the same even when only the on-off valve 60 is closed.

  On the other hand, the section G is a section in which the cooling water flows in the direction of arrow F even when both the thermostat 30 and the on-off valve 60 are closed or only the on-off valve 60 is closed. . In the present embodiment, the temperature sensing portion Sa of the water temperature sensor S is positioned in the section G. For this reason, even if both the thermostat 30 and the on-off valve 60 are closed or only the on-off valve 60 is closed, cooling water from the engine 10 flows around the temperature sensing portion Sa of the water temperature sensor S, A decrease in detection accuracy of the temperature of the cooling water that has passed through the engine 10 is suppressed.

  When the on-off valve 60 is in the open state, most of the cooling water flowing through the outlet pipe 51 flows toward the heater core 70, but the temperature sensing portion Sa of the water temperature sensor S is located in the outlet pipe 51, so It is in a position where it is also exposed to cooling water flowing to the side. For this reason, even in this case, the detection accuracy of the temperature of the cooling water that has passed through the engine 10 is ensured.

  Further, when the on-off valve 60 is in the open state, the cooling water after passing through the heater core 70 does not flow around the temperature sensing portion Sa. This is because the temperature sensing part Sa is not located in the return pipe 53 through which the cooling water after passing through the heater core 70 flows. For this reason, the temperature of the cooling water before passing through the engine 10 and flowing into the heater core 70 can be detected with high accuracy, and for example, temperature control when the vehicle interior is heated by the heater core 70 can be accurately performed. In addition, the temperature sensing part Sa of the water temperature sensor S may be in any position as long as it is within the section G in which the cooling water flows.

  Next, outlet parts 50A and 50B according to a modification will be described. In addition, about a modification, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol as the Example mentioned above. 3A and 3B are enlarged views of outlet portions 50A and 50B in the first and second modifications, respectively.

  As shown in FIG. 3A, the temperature sensing part Sa of the water temperature sensor S may be located upstream of the inlet 55a and downstream of the inlet 51a. Further, as shown in FIG. 3B, the water temperature sensor SB may be provided in the bypass pipe 55B, and the temperature sensing part Sa may be located in the bypass pipe 55B. This is because even when the temperature sensing part Sa is located in the bypass pipe 55B, the cooling water flows through the bypass pipe 55B regardless of the open / close state of the on-off valve 60.

  In the present embodiment and the modified example, the water temperature sensors S and SB are provided in the outlet pipe 51 and the bypass pipe 55B, respectively, but the position where the water temperature sensor itself is provided does not matter.

  Next, a cooling device 1C according to another embodiment will be described. FIG. 4 is a schematic configuration diagram of a cooling device 1C according to another embodiment. Unlike the cooling device 1, the outlet 50C of the cooling device 1C does not include the return pipe 53 and the bypass pipe 55, and the flow path 14w is not formed in the engine 10C. The path Wbc has a path 8w that connects the heater core 70 and the thermostat 30 without passing through the engine 10C, and a path 9w that communicates with the outlet pipe 51 and bypasses the heater core 70 and communicates with the path 8w. .

  The path 8w is an example of a return path communicating from the heater core 70 to the thermostat 30. The path 9w is an example of a bypass path that communicates with the outlet pipe 51 and the path 8w and bypasses the heater core 70. Further, the upstream end of the path 9w communicating with the outlet pipe 51 corresponds to the inlet of the bypass path, and the downstream end of the path 9w communicated with the path 8w corresponds to the outlet of the bypass path.

  As described above, even when the cooling water that has passed through the heater core 70 flows directly to the thermostat 30, the temperature sensing portion Sa of the water temperature sensor S passes from the inlet of the outlet pipe 51 through the inlet of the path 9 w to the path 9 w. It suffices if it is located in the section to the exit. Also in this case, even if the thermostat 30 and the on-off valve 60 are closed, the cooling water flows from the outlet pipe 51 to the path 9w as long as the water pump 40 is driven. The water temperature sensor S may be provided on the path 9w, and the temperature sensing unit Sa may be located in the path 9w.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

DESCRIPTION OF SYMBOLS 1 Engine cooling device 10 Engine 30 Thermostat 40 Water pump 50 Outlet part 51 Outlet pipe (1st outlet pipe)
55 Bypass pipe (bypass route)
60 On-off valve 70 Heater core S Water temperature sensor Sa Temperature sensing part G section

The above-mentioned object is that a coolant is circulated in the order of a water pump, an engine, a radiator, and a thermostat, and the opening and closing of the path is switched by opening and closing the thermostat, and the engine, the on-off valve, the heater core, The cooling water circulates in the order of the thermostat, the path is opened regardless of opening and closing of the thermostat, and the part of the first path is joined in the engine and branched from the first path in the engine. And a water temperature sensor having a temperature sensing part for detecting the temperature of the cooling water, wherein the second path communicates from the engine to the heater core and from the heater core to the thermostat. and the return path, the path between the engine and the on-off valve in the heater core path the A bypass path that bypasses the heater core by communicating with the heater path, and the temperature sensing unit is in a section from the inlet of the heater core path to the outlet of the bypass path through the inlet of the bypass path. It can be achieved by the engine cooling system being located.

Claims (2)

A first path through which cooling water circulates from the water pump to the engine, radiator, and thermostat;
From the water pump, the coolant circulates in the order of the engine, the on-off valve, the heater core, and the thermostat, and merges with a part of the first path in the engine and branches from the first path in the engine. The second path;
A water temperature sensor having a temperature sensing part for detecting the temperature of the cooling water,
The second path includes a heater core path that communicates from the engine to the heater core, a return path that communicates from the heater core to the thermostat, and a bypass path that communicates the heater core path and the return path to bypass the heater core. Have
The temperature sensing unit is an engine cooling device that is located in a section from an inlet of the heater core path to an outlet of the bypass path through an inlet of the bypass path. The heater core path has a first outlet pipe attached to the engine;
The return path includes a return pipe attached to the engine, a flow path formed in the engine in communication with the return pipe, a second outlet pipe in communication with the flow path and attached to the engine, Have
The bypass path has a bypass pipe communicating the first outlet pipe and the return pipe,
The engine cooling apparatus according to claim 1, wherein the first outlet pipe and the return pipe are attached to a cylinder head of the engine.

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