Engine cooling device

Abstract

To provide an engine cooling device that is suppressed in cost of manufacture.SOLUTION: An engine cooling device includes: a water pump for pumping cooling water; a first passage through which the cooling water circulates between the water pump and a heater core; a second passage through which the cooling water circulates between the water pump and an engine; and a valve mechanism for opening and closing the second passage in accordance with pressure of the cooling water from the water pump.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an engine cooling device. [Background technology]

[0002] 2. Description of the Related Art An engine cooling device is known that is provided with a multifunction valve capable of switching a flow path of cooling water (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-031817 A Summary of the Invention [Problem to be solved by the invention]

[0004] Multi-function valves have a complicated structure and their control is also complicated, which may increase manufacturing costs.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an engine cooling device that can be manufactured at reduced costs. [Means for solving the problem]

[0006] The above objective can be achieved by an engine cooling device comprising a water pump that pressure-pumps coolant, a first path that circulates the coolant between the water pump and a heater core, a second path that circulates the coolant between the water pump and an engine, and a valve mechanism that opens and closes the second path in response to the pressure of the coolant from the water pump. Effect of the Invention

[0007] According to the present invention, it is possible to provide an engine cooling device with reduced manufacturing costs. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of a cooling device. [Diagram 2] 2A and 2B are explanatory diagrams of the valve mechanism. [Diagram 3] FIG. 3A is an explanatory diagram of the cooling water flow path when the passage is closed by the valve mechanism, and FIG. 3B is an explanatory diagram of the cooling water flow path when the passage is opened by the valve mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Outline of cooling system configuration] FIG. 1 is a schematic diagram of a cooling device 1. The cooling device 1 is mounted on, for example, a hybrid vehicle. The cooling device 1 includes a cooling passage 3, an electric water pump 11, a valve mechanism 12, a heater core 13, an electric heater 14, an engine 15, a radiator 16, and a thermostat 17. The cooling passage 3 includes passages 31 to 38. The passage 31 connects the valve mechanism 12 and the heater core 13. The passage 32 connects the heater core 13 and the electric heater 14. The passage 33 connects the electric heater 14 and the passage 38. The passage 34 connects the heater core 13 and the engine 15. The passage 35 connects the valve mechanism 12 and the radiator 16. The passage 36 connects the passage 35 and the engine 15. The passage 37 connects the radiator 16 and the engine 15. The thermostat 17 is provided on the passage 37 .

[0010] Electric water pump 11 is an electric pump that pressure-feeds coolant toward valve mechanism 12. Valve mechanism 12 will be described in detail later. Heater core 13 heats the vehicle interior by heat exchange between the coolant and the air in the vehicle interior. Electric heater 14 heats the coolant. Engine 15 is cooled by the coolant. Engine 15 is the driving power source for the hybrid vehicle. Radiator 16 cools the coolant by heat exchange between the coolant and outside air. Thermostat 17 opens when the coolant temperature is equal to or higher than a predetermined temperature and closes when the coolant temperature is below the predetermined temperature.

[0011] The electric water pump 11 and the electric heater 14 are electrically connected to an ECU (Electronic Control Unit) 50. The ECU 50 includes a storage device such as a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and a flash memory. The ECU 50 controls the output of the electric water pump 11 according to the driving state. When the temperature of the coolant is low and the heater core 13 cannot obtain the heat required for heating, the ECU 50 drives the electric heater 14 to heat the coolant. The ECU 50 also controls the engine 15 and a motor for running (not shown) according to a control program previously stored in the ROM, based on information from sensors and information previously stored in the ROM or the storage device.

[0012] [Valve mechanism configuration] 2A and 2B are explanatory diagrams of the valve mechanism 12. The valve mechanism 12 includes a housing 121, a valve body 125, and a coil spring 126. Flow paths 122, 123, and 124 are formed within the housing 121. Coolant flows through the flow path 122 from the electric water pump 11. The flow path 122 communicates with the flow paths 123 and 124. The flow path 123 communicates with the passage 31. The flow path 124 communicates with the passage 35.

[0013] A valve body 125 and a coil spring 126 are disposed at a communication portion between the flow passage 122 and the flow passage 124. One end of the coil spring 126 is fixed to the valve body 125, and the other end of the coil spring 126 is fixed to the housing 121. The coil spring 126 can expand and contract in a direction in which the flow passage 122 extends. When the coil spring 126 is at its natural length, the valve body 125 is located at a portion where the flow passage 122 and the flow passage 124 communicate with each other, and the valve body 125 is in a closed position where the flow passage 124 is closed. When the coil spring 126 contracts, the valve body 125 retreats from the portion where the flow passage 122 and the flow passage 124 communicate with each other, and the valve body 125 moves to an open position where the flow passage 124 is opened. The valve body 125 opens and closes the flow passage 124 in response to the pressure of the coolant received from the electric water pump 11 via the flow passage 122.

[0014] FIG. 2A shows a state where the valve body 125 is in a closed position. When the force that the valve body 125 receives from the cooling water is equal to or less than the biasing force of the coil spring 126, the valve body 125 is maintained in the closed position. As a result, the cooling water flows from the flow path 122 to the flow path 123. FIG. 2B shows a state where the valve body 125 is in an open position. When the force that the valve body 125 receives from the cooling water is greater than the biasing force of the coil spring 126, the valve body 125 moves from the closed position to the open position. As a result, the cooling water flows from the flow path 122 to the flow path 123 and the flow path 124. Here, as described above, the output of the electric water pump 11 is controlled by the ECU 50. Therefore, the flow path 124 is opened and closed depending on the output of the electric water pump 11. That is, the valve mechanism 12 opens and closes the passage 35 depending on the discharge amount of the electric water pump 11. Since the valve mechanism 12 has a simple structure including the valve body 125 and the coil spring 126, the manufacturing cost of the cooling device 1 is suppressed.

[0015] 3A is an explanatory diagram of the flow path of the coolant when the passage 35 is closed by the valve mechanism 12. In this state, the coolant pumped from the electric water pump 11 to the valve mechanism 12 flows to the heater core 13 through the passage 31. A part of the coolant that flows into the heater core 13 flows to the electric heater 14 through the passage 32. The coolant that flows into the electric heater 14 flows back into the electric water pump 11 through the passages 33 and 38. A part of the coolant that flows into the heater core 13 flows to the engine 15 through the passage 34. The coolant that flows into the engine 15 flows back into the electric water pump 11 through the passage 38. In this way, the coolant circulates through the heater core 13, the electric heater 14, and the engine 15. The passages 31 to 33 and 38 are an example of a first path.

[0016] 3B is an explanatory diagram of the flow path of the coolant when the passage 35 is opened by the valve mechanism 12. In this state, the coolant circulates through the heater core 13, the electric heater 14, and the engine 15, and also circulates from the valve mechanism 12 through the engine 15 and the radiator 16 via the passages 35-38. When the thermostat 17 is closed, the coolant circulates through the heater core 13, the electric heater 14, and the engine 15. The passages 35, 36, 37, and 38 are an example of a second path. The flow rate of the coolant passing through the engine 15 is greater in the state of FIG. 3B than in the state of FIG. 3A.

[0017] As described above, the cooling device 1 is mounted on a hybrid vehicle. The driving mode of the hybrid vehicle can be switched between a hybrid driving mode in which the engine 15 is driven, and a motor driving mode in which the engine 15 is stopped. In the motor driving mode, there is little need to cool the engine 15. For this reason, by controlling the output of the electric water pump 11 to a low level, the flow rate of the cooling water to the engine 15 can be suppressed as shown in Figs. 2A and 3A, while ensuring the flow rate of the cooling water to the heater core 13 and the electric heater 14, allowing heating to be used.

[0018] In the hybrid driving mode, it is necessary to cool the engine 15. For this reason, by controlling the output of the electric water pump 11 to be high, the flow rate of the cooling water to the engine 15 and the flow rate of the cooling water to the heater core 13 and the electric heater 14 are ensured as shown in Fig. 2B and Fig. 3B, so that the engine 15 can be cooled while heating is utilized. Note that the ECU 50 increases or decreases the output of the electric water pump 11 above the output of the electric water pump 11 at which the valve mechanism 12 opens the passage 35. This makes it possible to change the flow rate of the cooling water circulating through the engine 15 and the radiator 16.

[0019] The electric water pump 11 and the valve mechanism 12 may be integrated into a common housing. The electric water pump 11 and the valve mechanism 12 may be in communication with each other via piping.

[0020] 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 variations are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0021] 1 Cooling device 3 Cooling passage 11 Electric water pump 12 Valve mechanism 13 Heater core 14 Electric heater 15 Engine 31, 32, 33, 38 Passages (1st Route) 35, 36, 37, 38 Passages (2nd Route)

Claims

[Claim 1] A water pump that pumps cooling water; a first passage for circulating cooling water between the water pump and a heater core; a second passage for circulating cooling water between the water pump and an engine; a valve mechanism that opens and closes the second path in response to a pressure of the cooling water from the water pump.

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