摘要:
When the engine is stopped while the engine is warmed up, the cooling water in the engine stays therein without flowing out of the engine, and the cooling water in the radiator or the bypass passage is used for heating source for the heating operation. In this way, it is possible to heat the passenger compartment continuously even after the engine is stopped and to suppress the temperature of the cooling water from lowering to reduce the emission at restarting of the engine.
摘要:
To be able to control minute flow in a heat exchanger flow control valve without requiring a minute opening portion, an opening surface area of a hot-water inlet pipe into which hot water flows from an engine is restricted by a first restricting portion of a control passage provided in a needle valve of a flow control valve, and along with this, an opening surface area of a hot-water outlet pipe connected to an inlet side of a heat exchanger for heater use is restricted by a second restricting portion of a control passage formed in the needle valve, and a middle portion of these two control passages is constantly connected to a bypass circuit by a third restricting portion. Pressure of the middle portion thereof can thereby be lowered, pressure applied to the heat exchanger can be adequately reduced, and for this reason minute flow through the valve can be controlled even without establishing a minute opening portion using the needle valves Also, change in heat-exchanger hot-water flow can be reduced by structuring the first and second restricting portions in a configuration whereby flow constant is reduced as amount of flow increases and, along with this, structuring the third restricting portion in a configuration whereby flow constant is maintained substantially uniformly even if amount of flow increases.
摘要:
To control fluctuation of blown air temperature of a heat exchanger to a small value without adding a movable mechanism such as a variable restricting valve, a heat exchanger for heating air by exchanging heat between hot water supplied from a water-cooling type engine and air, a flow control valve for controlling a hot water flow amount to the heat exchanger and a bypass circuit for allowing hot water to flow while bypassing the heat exchanger are provided. A pressure-responsive valve is provided on the bypass circuit and an opening degree of the bypass circuit corresponding to a pressure rise of the hot water is increased. The flow of returning hot water from the heat exchanger is blocked by the flow of the bypass side hot water at a merging portion where the bypass side hot water discharged from the pressure-responsive valve merges with the returning hot water discharged from the heat exchanger.
摘要:
A flow-quantity control valve controlling hot-water flow to a heat exchanger and a bypass circuit allowing hot water to bypass the heat exchanger are provided along with a pressure-actuated valve in the bypass circuit which is responsive to a pressure increase of hot water from an engine. Inlet-side opening portions, outlet-side opening portions, and a bypass-side opening portion are provided in a control passage of a valve body of the flow-quantity control valve. Main flow of dynamic pressure of hot water sprayed from portions on a small opening-degree side act upon a valve body side of the pressure-actuated valve. Due to this, dynamic pressure of the hot water in a small opening-degree region of the flow-quantity control valve can be effectively used to increase a valve-lift quantity of the pressure-actuated valve, thereby reducing a fluctuation range of blown-air temperature of the heat exchanger. Also, the flow may be bent so that hot-water flow having a high dynamic-pressure component from the hot-water inlet pipe is not applied directly to the valve body of the differential-pressure valve; thus, lift of the differential-pressure valve can be prevented from becoming excessive, and a drop in heat-exchanger blown-air temperature at a predetermined opening-degree position of a flow-quantity control valve can effectively be suppressed.
摘要:
A heating apparatus of a re-heat type for an air conditioning system for a vehicle provided with an internal combustion engine. The heating apparatus includes a flow control valve for controlling an amount of an engine hot water directed to a heat exchanger for heating. When the degree of the opening of the flow control valve is 2/8 or less and when the target degree of the opening of the flow control valve is 2/8 or more, a control of the degree of the opening of the flow control valve to the target opening plus a predetermined overshoot amount is initially executed, which is followed by a control to the target opening. When both of the initial and target opening is larger than 2/8 or the initial and target opening are identical, the overshoot control is not carried out, i.e., the degree of the opening of the flow control valve is directly controlled to the target value.
摘要:
The total flow rate of the hot water flowing to a first heater core and a second heater core is controlled by a total flow rate control valve, and then the flow rate of the hot water to each of the heater cores is distributed by a distribution valve. According to this configuration, the flow rate of the hot water flowing through each of the heater cores is linearly controlled. Therefore, the heating of the driver's seat space by the first heater core and the heating of the air conditioning of the passenger's seat space by the second heater core can be linearly controlled.
摘要:
A plurality of flow control valves is correspondingly provided to a plurality of heater core portions. Each of the flow control valves is provided with a first restriction portion formed in an inlet for receiving hot water, a second restriction portion in an outlet for introducing hot water to the respective heating heat exchange portions, and a bypass opening opened at an intermediate pressure portion between the first restriction portion and the second restriction portion. Each opening area of the first restriction portion, the second restriction portion, and the bypass openings is regulated by a cylindrical valve. The first and second restriction portions, the bypass openings and the valve bodies are accommodated within a common housing, and a bypass passage communicating with the bypass openings is formed in the common housing.
摘要:
In a vehicle air conditioner, first and second downstream side passages are provided in an air conditioning case to guide air to a defroster opening and a foot opening, respectively. A switching door is capable of switching between a partition position for partitioning the first downstream side passage and the second downstream side passage from each other, and a communication position for establishing communication between the first downstream side passage and the second downstream side passage. An air outlet mode switching device is capable of switching between a foot mode and a foot/defroster mode. In the foot mode, the air outlet mode switching device causes both the foot door and defroster door to be opened and causes the first switching door to be set at the partition position. Therefore, it is possible to prevent a problem due to an air outlet mode door with a small opening degree.
摘要:
In a vehicle air conditioner, a flow control member is disposed in an inlet tank of a heating heat exchanger for heating air to be blown into a passenger compartment using a fluid as a heating source. In the heating heat exchanger, a ratio between a first area where the fluid flows, and a second area where the fluid does not flow is changed by controlling an operation position of the flow control member. Thus, a flow ratio between hot air from the first area of the heating heat exchanger and cool air from the second area thereof can be adjusted, so that the temperature of air blown into the passenger compartment can be adjusted.
摘要:
A heat exchanger has tubes, an inlet tank and an outlet tank. The inlet tank and the outlet tank are coupled to ends of the tubes. The inlet tank and the outlet tank have an inlet port and an outlet port, respectively, on ends thereof. The heat exchanger further has a cover member disposed in at least one of the inlet tank and the outlet tank. The cover member partly covers openings of the ends of predetermined tubes of the tubes, the predetermined tubes being closer to at least one of the inlet port and the outlet port.