RU2251623C1 - Electrically controlled thermostat - Google Patents

Abstract

FIELD: transport engineering; automobile engine cooling systems.

SUBSTANCE: invention relates to devices for control and regulation of temperature of medium circulating in cooling systems of internal combustion engines. Proposed thermostat connected with control unit has housing with branch pipes to let in and out of cooling liquid, cover with branch pipe to supply cooling liquid to radiator rigidly secured on housing. Housing accommodates rotary electromagnet with flat main and auxiliary valves installed on rotor. Main rotary valve consists of movable and fixed diaphragms. Auxiliary rotary valve is formed by outlet hole of housing outlet branch pipe and second movable diaphragm.

EFFECT: simplified control of engine cooling, improved reliability of cooling system.

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Description

The invention relates to devices for monitoring and controlling the temperature of a moving medium, and in particular to thermostats of a cooling system for automotive internal combustion engines.

Known thermostats for automotive engines according to patents No. 2312739 A, Great Britain (priority from 01/30/1997) and No. 19844711 A1, Germany (priority from 09/29/1998), consisting of a housing with elements for connecting to the cooling system of automobile engines. Inside the body, the main and auxiliary valves are located, which are actuated by a temperature sensor filled with a thermoset solid filler (for example, a thermal wax) and equipped with an electric resistor as a heating element. The resistor is installed inside the housing of the temperature sensor in the immediate vicinity of its rod and may take the form of a sleeve, a tablet or individual film resistors located around the sensor rod. Depending on the temperature of the liquid in the cooling system, the thermosetting filler changes its volume and through the sensor rod changes the position of the valves, directing or regulating the fluid flow in a small circle or a large circle through the radiator. The heating element, if necessary, accelerates the process of volume expansion of the thermosetting filler and shifts the opening temperature of the main valve.

The closest technical solution is the "Control system for cooling internal combustion engines" according to patent EP 0978641 A1, European Patent Agency (priority from 08/06/1998), which includes a control unit with sensors for monitoring the temperature of the coolant and the position of the opening angle of the engine throttle , electric motor, gearbox, clutch mechanism, thermostat, consisting of a housing with a nozzle for supplying coolant from the engine, rigidly fixed to the housing of the cover with a nozzle for cooling barrier liquid to the radiator, disposed within the casing rotary throttle valve return spring, the throttle angle sensor rotation of the rotary valve. In this system, the thermostat controls the amount of coolant flow passing through the radiator, depending on external factors (coolant temperature, engine throttle opening angle, etc.) as follows. When external factors change, the control unit generates a signal for rotation of the electric motor. The electric motor through the clutch mechanism and gearbox rotates the rotary throttle valve to the position specified by the control unit, which is fixed by the angle sensor. In the event of an emergency, the clutch disengages the electric motor and the return spring sets the rotary valve to the open position.

The disadvantage of the above system is that the use of an electric motor requires additional elements of the system (clutch mechanism, gearbox, etc.), which significantly increases the size and reduces the reliability of the engine cooling system.

The technical task of the invention is to expand the functionality of the thermostat and simplify the control system for cooling the engine, increasing its reliability.

The technical result is achieved by the fact that in the proposed device the housing has a nozzle for draining the coolant into a small circle, and the outlet of the small circle nozzle is made in the form of segment cutouts, the main rotary valve consists of two diaphragms (movable and stationary) with segment cutouts, the movable diaphragm is pressed against the fixed torsion return spring, the auxiliary rotary valve is formed by the outlet of the nozzle of the small circle of the housing and the second movable diaphragm, which Torai is pressed to the outlet by a compression spring, a rotary electromagnet, consisting of a magnetic circuit, an armature, an electric coil and a shaft, with rotary valves installed at the ends of the shaft, is located inside the housing and is locked from axial movement by a lock washer, the terminals of the electric coil are connected to the connector mounted on case.

Figure 1 presents a simplified diagram of a thermostat with electric control in its original position.

In the housing 1 with nozzles for supplying coolant from the engine and exhaust to the radiator, the outlet of the small circle nozzle is made in the form of segment cutouts (see Fig. 2), a rotary electromagnet 2 with the main and auxiliary valves located coaxially with the electromagnet rotor is installed. Cover 3 with a nozzle for draining the coolant to the radiator is rigidly fixed to the body 1 by screws 4. The main rotary valve consists of two diaphragms having segment cutouts similar to the cutouts of the body 1. The fixed diaphragm 5 of the main valve is mounted coaxially to the rotor of the electromagnet 2 and is fixed motionless between the body 1 and cover 3. The movable diaphragm 6 of the main valve is installed on the rotor side of the electromagnet 2 and is pressed against the stationary diaphragm 5 by a torsion spring 7, the hook of which is fixed in from the rotor of the electromagnet 2 and is fixed by a lock washer 8. The auxiliary rotary valve is formed by the outlet of a small circle with segment cutouts and a second movable diaphragm 9, also having segment cutouts, mounted on the other side of the electromagnet rotor, which is pressed against the outlet of the small circle of the housing 1 by a spring compression 10. The lock washer 11 prevents the axial movement of the rotor of the electromagnet 2. The conclusions of the electromagnet 2 are connected to the connector 12 mounted on the housing 1 with an external ones.

The thermostat with electric control operates as follows.

In the initial position, in the absence of a DC signal at the input of the coil (car ignition is not turned on), the main valve of the thermostat is normally open - the segment cutouts of the diaphragms 8, 9 are aligned, the auxiliary valve is normally closed, the segment cutouts of the diaphragm 12 are rotated 90 degrees relative to the cutouts of housing 1. V when the engine starts, signals from electronic sensors (coolant temperature, ambient temperature, speed, engine load, etc.) are sent to the electronic control unit, into the cat An optimal algorithm for regulating the temperature of the coolant is formed, and the DC control signal is supplied to the thermostat by the control unit, the value of which corresponds to the complete closure of the main valve, the electromagnet drives the movable diaphragms of the valves in a clockwise direction. When the main valve is completely closed, the segment cutouts of the diaphragms are shifted by 90 degrees and the auxiliary valve is fully opened. The engine warms up.

With increasing temperature of the coolant (or increasing engine load, etc.), the control unit decreases the direct current value, therefore, the electromagnet moment decreases, the return spring 9 opens the main valve and closes the auxiliary valve. When the engine is fully warmed up, which corresponds to the specified operating mode, the thermostat practically does not consume electrical energy.

In addition, the design of the proposed thermostat is such that in the case of filling the cooling system with coolant through a normally open main valve, an unhindered removal of air from the system occurs, which significantly reduces the time loss during the installation of the thermostat and its possible failure (for example, breakdown of the coil conductors) . The valves return torsion spring back to its original position, which ensures safe failure of the thermostat.

Thus, an electrically controlled thermostat constantly monitors and regulates the temperature of the engine coolant depending on the signals of electronic sensors (coolant temperature, ambient temperature, taking into account the current speed value, etc.) in real time. By changing the amount of current load, the electronic control unit gives the command to open or close the main and auxiliary valves of the thermostat, which ensures the optimal specified thermal operating mode of the engine, optimizes fuel consumption and reduces the content of harmful substances in the exhaust gas.

The proposed thermostat is compact, has a low inertia, can significantly improve the economic and environmental performance of automotive internal combustion engines in general.

Claims (1)

An electrically controlled thermostat connected to the control unit, comprising a housing with a nozzle for supplying coolant from the engine, a main rotary valve located inside the housing, a cover rigidly fixed to the housing with a nozzle for draining coolant to a large circle (radiator), a return spring that differs the fact that the thermostat housing has an additional nozzle of the small circle of the cooling system, a rotary electromagnet is located inside the thermostat housing, on the rotor of which there are flat new and auxiliary valves, the main rotary valve consists of two diaphragms, movable and stationary, with segment cutouts, the auxiliary rotary valve is formed by the outlet of the small circle nozzle made in the form of segment cutouts, and the second movable diaphragm with segment cutouts, on the outside of the housing connector for connecting the control unit to the rotary electromagnet.

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