JPH048247B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a cooling system control device for an internal combustion engine that can be used in a heater device for an automobile engine.

(Prior art) Automotive heater devices use the engine's cooling water as a heat source and transfer heat to the air through a radiator, but the higher the temperature of the water flowing into the heater radiator, or the greater the amount of water flowing into the heater radiator. The amount of heat dissipated is greater.

Conventionally, as a means of increasing the heater circuit flow rate,
Japanese Unexamined Patent Publication No. 165820/1983 discloses a technique in which the bypass circuit is narrowed down when the heater is turned on. However, in this case, the flow supply source for supplying water to the heater circuit is a water pump driven by the crankshaft of the engine, which has the disadvantage that the flow rate decreases at low rotation speeds. Note that it is desirable that the heating by the heater be constant regardless of the operating conditions of the vehicle.

(Problems to be Solved by the Invention) The present invention attempts to solve problems in conventional engine cooling systems, such as a decrease in the flow rate of the heater circuit when the engine rotates at low speeds.

[Structure of the invention]

(Means for Solving the Problems) Therefore, the present invention provides for branching a circulation flow path from a circuit of an engine cooling device having an engine-driven water pump that circulates cooling water, and providing a heater circuit configured on the circulation flow path. An electric water pump driven by an electric motor and a pressure-sensitive one-way valve are arranged in parallel, a radiator and a throttle valve are provided in series with the parallel circuit, and the water temperature is controlled on the water inlet side of the radiator. a sensor and a flow rate sensor in series circuit;
Furthermore, an outside temperature sensor for detecting the outside temperature and a vehicle interior temperature sensor for detecting the interior temperature of the vehicle are installed, and the water pump in the heater circuit is activated in response to signals from each of the sensors according to the set temperature in the vehicle interior. The control unit includes a control unit that determines the rotational speed and the opening degree of the throttle valve and issues command signals to the water pump and the throttle valve, and is used as a means for solving the problem.

(Function) If the flow rate in the heater circuit sent from the engine-driven water pump is insufficient for a given temperature, calculated from the temperature of the water and the outside temperature,
The electric water pump operates and increases the heater circuit flow rate to a predetermined value (throttle valve fully open). On the other hand, if the heater flow rate is high, the electric water pump is stopped and the water is controlled by the throttle valve to a predetermined flow rate. The controller in each case
Control is performed while measuring the heating air temperature.

(Embodiments) The present invention will be described below with reference to embodiments of the drawings. FIGS. 1 and 2 show embodiments of the present invention,
In the heater circuit 20, an electric water pump 7 and a pressure-sensitive one-way valve 9 are arranged in parallel, a radiator (heater radiator) 5 and a throttle valve 1 are provided in series with the parallel circuit, and the radiator It is equipped with a water temperature sensor 12 and a flow sensor 6 provided on the water inlet side of 5, as well as an outside temperature sensor 13 and a vehicle interior temperature sensor 14, and further receives signals from the above-mentioned sensors regarding the vehicle interior temperature. The control unit 8 determines the rotational speed of the electric water pump 7 and the opening degree of the throttle valve 1, and issues command signals. In the figure, 2 is an engine-driven water pump, 3 and 4 are cooling water flow paths in the heater circuit 20, 10 is a conical valve, and 11 is a spring.

Next, to explain the operation, when the heater is OFF, the throttle valve 1 is fully closed, and even if the engine-driven water pump 2 is working, no cooling water flows into the flow paths 3 and 4 of the heater circuit 20. When the heater is turned on and a certain temperature is requested by manual operation inside the vehicle,
The throttle valve 1 opens the heater circuit 20 with a predetermined opening degree, water flows into the radiator 5 due to the water supply action of the engine-driven water pump 2, and hot air is blown into the passenger compartment. When the temperature of the hot air blown out (≒vehicle interior temperature) is lower than the required value, the first step is to move the opening degree of the throttle valve 1 toward the larger direction to increase the flow rates of the flow paths 3 and 4. This flow rate is constantly detected and controlled by a flow rate sensor 6.

Next, if the temperature is still low, the control unit 8 instructs the electric water pump 7 to rotate.
A signal is given from the pump 7, and the pump 7 starts pumping water and works to maintain the required temperature. The opening degree of the throttle valve 1 and the rotation speed of the electric water pump 7 are calculated from the difference between the set temperature and the hot air temperature, the inlet water temperature of the radiator 5, the outside temperature, and the flow rate, and instructions are issued from the control unit 8 as appropriate. Served. The control unit 8 then continues to control so that the difference between the hot air temperature and the set temperature is below a certain value.

Conversely, when the hot air temperature is higher than the set temperature, the electric water pump 7 stops and the throttle valve 1 maintains the opening specified by the control unit 8 in the same manner as described above. Therefore, unlike conventional automatic air conditioners, this embodiment does not turn on and off the hot air blowout intermittently, but continuously adjusts the temperature of the hot air, improving the feeling for the occupants.

FIG. 2 shows a side sectional view showing an example of the one-way valve 9 in FIG.
The conical valve 10 receives pressure on the upstream A side and moves to the left in the drawing against the spring 11, and the cooling water mainly flows through the passage A-C-D-F (a small amount also flows on the pump side). Also, when the pump 7 rotates, C, D,
Since the pressure on the E and F sides becomes higher than on the A and B sides, the conical valve 10 moves to the left in the drawing, and the water flows to the A-
Flows through B-Pump-E-D-F. In other words, the pressure type one-way valve has the function of reducing water flow resistance when the pump is stopped, and the short circuit (B-Pump-E-
D-C-B).

〔Effect of the invention〕

Since the present invention is configured as described in detail above, if the flow rate in the heater circuit sent from the water pump is insufficient for the required temperature based on the temperature of the water and the outside air temperature, the water pump It operates to increase the circuit flow rate to a predetermined value.
If the heater flow rate is high, the water pump is stopped and the water is controlled by the throttle valve to a predetermined flow rate. Therefore, according to the present invention, the heating level of the heater can be kept constant regardless of the engine speed and vehicle speed.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a cooling system control device showing an embodiment of the present invention, and FIG. 2 is a side sectional view showing an example of the one-way valve in FIG. 1. Explanation of the main parts of the diagram, 1... Throttle valve, 3, 4...
...Flow path, 5...Radiator, 6...Flow rate sensor, 7
... Electric water pump, 8 ... Control unit, 9 ... One-way valve, 12 ... Water temperature sensor, 13 ... Outside temperature sensor, 14 ... Vehicle interior temperature sensor.

Claims (1)

[Claims] 1. A circulation flow path is branched from a circuit of an engine cooling system having an engine-driven water pump that circulates cooling water, and a water pump driven by an electric motor and a pressure-sensitive water pump are installed in a heater circuit configured on the circulation flow path. A one-way valve is arranged in parallel, a radiator and a throttle valve are provided in series with the parallel circuit, a water temperature sensor and a flow rate sensor of the series circuit are provided on the water inlet side of the radiator, and the outside temperature is detected. An outside air temperature sensor is installed to detect the temperature inside the car, and an inside temperature sensor is installed to detect the inside temperature of the car. 1. A cooling system control device for an internal combustion engine, comprising a control unit that determines the opening degree of the water pump and the throttle valve and issues command signals to the water pump and the throttle valve.