GB2026610A

GB2026610A - An internal combustion engine having an improved electrical circuit for the drive of a cooling air blower

Info

Publication number: GB2026610A
Application number: GB7921426A
Authority: GB
Original assignee: PROSCHE AG HCF
Current assignee: PROSCHE AG HCF
Priority date: 1978-06-22
Filing date: 1979-06-20
Publication date: 1980-02-06
Also published as: GB2026610B; IT7923365A0; FR2429325A1; IT1120942B; DE2827373A1; FR2429325B3

Abstract

The cooling air blower is driven by at least two separate electric motors 10, 11, which are controlled by a temperature sensor 1 which operates relays 6, 9 via switches 3, 4, so that the motors are connected in series upon a lower temperature range being reached and connected in parallel upon a higher temperature range being reached. <IMAGE>

Description

SPECIFICATION An internal combustion engine having an improved electrical circuit for the drive of a cooling air blower The invention relates to an internal combustion engine having an improved electrical circuit for the drive of cooling air blowers in an internal combustion engine driven by at least two separate electric motors.

In the driving of a cooling air blower for a water-cooled internal combustion engine in which the blower is driven by at least two separate electric motors, it is known to switch on the motors stepwise by means of a temperature sensor located in the coolant and an electronic control device actuated thereby. In this case one electric motor is switched on first when a lower temperature range has been reached, and the second electric motor is switched on additionally when a higher temperature range has been reached. If the temperature of the coolant is above the lower temperature range with the ignition switched off the first motor continues to run until the temperature of the coolant drops below the lower temperature range. To reduce noise, a resistor is connected in front of the first electric motor, so that this motor continues to run at a reduced speed.It has, however, proved particularly disadvantageous in this arrangement as the resistor gives rise to an appreciable loss of efficiency.

The object of the invention is to provide a drive for a cooling air blower in an internal combustion engine that retain the advantages of the conventional drive and eliminates the disadvantages thereof in a simple manner.

The present invention consists in an internal combustion engine which is cooled by an air blower driven by at least two separate electric motors, including an electrical circuit for the motors wherein the latter are connected in series upon a lower temperature range being reached and connected in parallel upon a higher temperature range being reached.

This arrangement ensures that within the lower temperature range two electric motors operate at half the operational voltage and in the upper temperature range at the full operational voltage of the motor vehicle. If the temperature drops once more into the lower temperature range the two motors will again operate at half the operational voltage of the motor vehicle. In addition to optimal cooling efficiency this circuit has the advantages of low noise within the lower temperature range, as well as of considerably less power consumption for substantially the same air throughput as for conventional blower drives.

Preferably, the engine is of the watercooled type and the electrical circuit comprises a temperature sensor responsive to the temperature of the cooling water and an electronic control device including a temperature switch effective upon the lower temperature range being reached and a further temperature switch effective upon the upper temperature range being reached, said first-mentioned temperature switch energising a relay which connects the electric motors in series, and said further switch corresponding to the upper temperature range energising a relay which connects the electric motors in parallel.

The accompanying drawing shows an electrical circuit for the drive to a cooling air blower of an internal combustion engine according to the present invention.

The circuit includes a temperature sensor 1 which is responsive to the temperature of the coolant in a water-cooled internal combustion engine and an electronic control device 2 which comprises a temperature switch 3 effective at a lower temperature range, e.g. from 750C upwards and a temperature switch 4 which is effective at an upper temperature range, e.g. from 900C upwards. The temperature switch 3 is connected to a closing contact 5 actuated by a relay 6, and the temperature switch 4 is connected to a double-throw switch 7 and 8 actuated by a relay 9. Electric motors 10, 11 drive a cooling air blower (not shown). An ignition switch 12 and a storage battery 13 also form part of the circuit.

The arrangement operates as follows: If the temperature of the coolant in a watercooled internal combustion engine, taking as the starting point the temperature ranges given above by way of example, with the ignition switch closed, has reached 750C, this information is passed by the temperature sensor 1 to the electronic control device 2, and the temperature switch 3 closes. The relay 6 is then energised, closing the contact 5 so that the electric motors 10 and 11 are connected in series, at 6.5 V assuming an operational voltage of 13 V. If the temperature of the cooling water reaches 900C the temperature switch 4 will likewise close thus energising the relay 9.The double-throw switches 7 and 8 are now closed and the two electric motors 10 and 11 are connected in parallel at the operational voltage of 13 V, so that the cooling effect of the blower is increased.

If the internal combustion engine is switched off by opening the ignition switch 1 2 and the temperature of the coolant is above 759C, although the relay 9 is de-energised, due to the opening of the ignition switch 12, the temperature of the coolant being over 750C, the voltage applied to the relay 6 causes the latter to remain energised so that the serially-connected electric motors 10 and 11 will continue operating until the temperature of the coolant falls below 750C. Only then will the temperature switch 3 open, the relay 6 be de-energised, and the electric motors 10 and 11 switched off.

1. An internal combustion engine which is cooled by an air blower driven by at least two separate electric motors, including an electrical circuit for the motors wherein the latter are connected in series upon a lower temperature range being reached.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION An internal combustion engine having an improved electrical circuit for the drive of a cooling air blower The invention relates to an internal combustion engine having an improved electrical circuit for the drive of cooling air blowers in an internal combustion engine driven by at least two separate electric motors. In the driving of a cooling air blower for a water-cooled internal combustion engine in which the blower is driven by at least two separate electric motors, it is known to switch on the motors stepwise by means of a temperature sensor located in the coolant and an electronic control device actuated thereby. In this case one electric motor is switched on first when a lower temperature range has been reached, and the second electric motor is switched on additionally when a higher temperature range has been reached. If the temperature of the coolant is above the lower temperature range with the ignition switched off the first motor continues to run until the temperature of the coolant drops below the lower temperature range. To reduce noise, a resistor is connected in front of the first electric motor, so that this motor continues to run at a reduced speed.It has, however, proved particularly disadvantageous in this arrangement as the resistor gives rise to an appreciable loss of efficiency. The object of the invention is to provide a drive for a cooling air blower in an internal combustion engine that retain the advantages of the conventional drive and eliminates the disadvantages thereof in a simple manner. The present invention consists in an internal combustion engine which is cooled by an air blower driven by at least two separate electric motors, including an electrical circuit for the motors wherein the latter are connected in series upon a lower temperature range being reached and connected in parallel upon a higher temperature range being reached. This arrangement ensures that within the lower temperature range two electric motors operate at half the operational voltage and in the upper temperature range at the full operational voltage of the motor vehicle. If the temperature drops once more into the lower temperature range the two motors will again operate at half the operational voltage of the motor vehicle. In addition to optimal cooling efficiency this circuit has the advantages of low noise within the lower temperature range, as well as of considerably less power consumption for substantially the same air throughput as for conventional blower drives. Preferably, the engine is of the watercooled type and the electrical circuit comprises a temperature sensor responsive to the temperature of the cooling water and an electronic control device including a temperature switch effective upon the lower temperature range being reached and a further temperature switch effective upon the upper temperature range being reached, said first-mentioned temperature switch energising a relay which connects the electric motors in series, and said further switch corresponding to the upper temperature range energising a relay which connects the electric motors in parallel. The accompanying drawing shows an electrical circuit for the drive to a cooling air blower of an internal combustion engine according to the present invention. The circuit includes a temperature sensor 1 which is responsive to the temperature of the coolant in a water-cooled internal combustion engine and an electronic control device 2 which comprises a temperature switch 3 effective at a lower temperature range, e.g. from 750C upwards and a temperature switch 4 which is effective at an upper temperature range, e.g. from 900C upwards. The temperature switch 3 is connected to a closing contact 5 actuated by a relay 6, and the temperature switch 4 is connected to a double-throw switch 7 and 8 actuated by a relay 9. Electric motors 10, 11 drive a cooling air blower (not shown). An ignition switch 12 and a storage battery 13 also form part of the circuit. The arrangement operates as follows: If the temperature of the coolant in a watercooled internal combustion engine, taking as the starting point the temperature ranges given above by way of example, with the ignition switch closed, has reached 750C, this information is passed by the temperature sensor 1 to the electronic control device 2, and the temperature switch 3 closes. The relay 6 is then energised, closing the contact 5 so that the electric motors 10 and 11 are connected in series, at 6.5 V assuming an operational voltage of 13 V. If the temperature of the cooling water reaches 900C the temperature switch 4 will likewise close thus energising the relay 9.The double-throw switches 7 and 8 are now closed and the two electric motors 10 and 11 are connected in parallel at the operational voltage of 13 V, so that the cooling effect of the blower is increased. If the internal combustion engine is switched off by opening the ignition switch 1 2 and the temperature of the coolant is above 759C, although the relay 9 is de-energised, due to the opening of the ignition switch 12, the temperature of the coolant being over 750C, the voltage applied to the relay 6 causes the latter to remain energised so that the serially-connected electric motors 10 and 11 will continue operating until the temperature of the coolant falls below 750C. Only then will the temperature switch 3 open, the relay 6 be de-energised, and the electric motors 10 and 11 switched off. CLAIMS

2. An internal combustion engine as claimed in claim 1 , wherein the engine is of the water-cooled type and the electrical circuit comprises a temperature sensor responsive to the temperature of the cooling water and an electronic control device including a temperature switch effective upon the lower temperature range being reached and a further temperature switch effective upon the upper temperature being reached, said firstmentioned temperature switch energising a relay which connects the electric motors in series, and said further temperature switch corresponding to the upper temperature range energising a relay which connects the electric motors in parallel.

3. An internal combustion engine substantially as described with reference to, and as illustrated in, the accompanying drawing.