Abstract: A cooling water control apparatus is a cooling water control apparatus for controlling a cooling apparatus having a first pipe which circulates cooling water through an engine; a second pipe which circulates the cooling water not through the engine; and a switching valve whose state is changed between opened and closed states, and has: a detecting device which detects first temperature of the cooling water in a pipe portion of the first pipe between the engine and the switching valve; and a determining device which determines that there is failure of the switching valve whose state is the closed state, if required period from the output of the command for changing the state of the switching valve from the opened state to the closed state until the first temperature reaches predetermined temperature is larger than predetermined target period.

Abstract: A cooling water control apparatus controls a cooling apparatus having first pipe which circulates cooling water through an engine; second pipe which circulates cooling water not through the engine; a switching valve whose state is changed between opened and closed states; and a supplying mechanism which supplies cooling water, and has a determining device which determines whether there is failure of the switching valve based on difference between first temperature of cooling water in first pipe and second temperature of cooling water in second pipe after the command for changing the state of the switching valve from closed state to opened state is outputted; and a controlling device which controls the supplying mechanism to supply cooling water even after the engine stops, when the engine stops while the determining device determines whether there is failure of the switching valve.

Abstract: A coolant control device includes: first control means for, at warm-up of an internal combustion engine, circulating coolant in a first passage bypassing the engine and stopping coolant circulation in the second passage passing through the engine; second control means for, at engine warm-up and when the quantity of heat required by a heater core is smaller than or equal to a predetermined threshold, circulating coolant in the first passage while adjusting the flow rate of coolant circulating in the first passage and stopping coolant circulation in the second passage; and third control means for, at engine warm-up and when the required quantity of heat exceeds the predetermined threshold, circulating coolant in the first passage without decreasing the flow rate of coolant circulating in the first passage and circulating coolant in the second passage while adjusting the flow rate of coolant circulating in the second passage.

Abstract: A heat management system for vehicles comprises: a first circulation circuit which cools an engine body of an internal combustion engine and includes a first pump for pressure-feeding a refrigerant; a second circulation circuit including an exhaust heat recovery apparatus for recovering exhaust heat from the internal combustion engine, a heater core used for air-conditioning of a vehicle, and a second pump for pressure-feeding the refrigerant; communication passages allowing the first circulation circuit to communicate with the second circulation circuit; and an on-off valve provided in the first communication passage, and switching between the communication between the first circulation circuit and the second circulation circuit and the preventing of communication therebetween, wherein the on-off valve is controlled such that the refrigerant temperature of the first circulation circuit is higher than that of the second circulation circuit.

Abstract: A cooling apparatus comprises a first cooling conduit branching off from a downstream side connection conduit to cool the cylinder head, a second cooling conduit branching off from the downstream side connection conduit, is provided in parallel with the first cooling conduit, an intermediate cooling conduit being connected to the first and second cooling conduits, is provided with an EGR cooler, a third cooling conduit running from a connection point of the intermediate cooling conduit and the first cooling conduit to an upstream side connection conduit, a fourth cooling conduit running from a connection point of the intermediate cooling conduit and the second cooling conduit to the upstream side connection conduit, and a changeover valve for adjusting the flow resistance of the second cooling conduit. And the direction of coolant flow in the intermediate cooling conduit is changed over by operating the changeover valve.

Abstract: A cooling water control apparatus is a cooling water control apparatus for controlling a cooling apparatus having a first pipe which circulates cooling water through an engine; a second pipe which circulates the cooling water not through the engine; and a switching valve whose state is changed between opened and closed states, and has: a detecting device which detects first temperature of the cooling water in a pipe portion of the first pipe between the engine and the switching valve; and a determining device which determines that there is failure of the switching valve whose state is the closed state, if required period from the output of the command for changing the state of the switching valve from the opened state to the closed state until the first temperature reaches predetermined temperature is larger than predetermined target period.

Abstract: A cooling water control apparatus controls a cooling apparatus having first pipe which circulates cooling water through an engine; second pipe which circulates cooling water not through the engine; a switching valve whose state is changed between opened and closed states; and a supplying mechanism which supplies cooling water, and has a determining device which determines whether there is failure of the switching valve based on difference between first temperature of cooling water in first pipe and second temperature of cooling water in second pipe after the command for changing the state of the switching valve from closed state to opened state is outputted; and a controlling device which controls the supplying mechanism to supply cooling water even after the engine stops, when the engine stops while the determining device determines whether there is failure of the switching valve.

Abstract: A cooling apparatus comprises a first cooling conduit branching off from a downstream side connection conduit to cool the cylinder head, a second cooling conduit branching off from the downstream side connection conduit, is provided in parallel with the first cooling conduit, an intermediate cooling conduit being connected to the first and second cooling conduits, is provided with an EGR cooler, a third cooling conduit running from a connection point of the intermediate cooling conduit and the first cooling conduit to an upstream side connection conduit, a fourth cooling conduit running from a connection point of the intermediate cooling conduit and the second cooling conduit to the upstream side connection conduit, and a changeover valve for adjusting the flow resistance of the second cooling conduit. And the direction of coolant flow in the intermediate cooling conduit is changed over by operating the changeover valve.

Abstract: A coolant control device includes: first control means for, at warm-up of an internal combustion engine, circulating coolant in a first passage bypassing the engine and stopping coolant circulation in the second passage passing through the engine; second control means 0 for, at engine warm-up and when the quantity of heat required by a heater core is smaller than or equal to a predetermined threshold, circulating coolant in the first passage while adjusting the flow rate of coolant circulating in the first passage and stopping coolant circulation in the second passage; and third control means for, at engine warm-up and when the required quantity of heat exceeds the predetermined threshold, circulating coolant in the first passage without decreasing the flow rate of coolant circulating in the first passage and circulating coolant in the second passage while adjusting the flow rate of coolant circulating in the second passage.