GB2025520A

GB2025520A - Cooling air conveying system for internal combustion engines

Info

Publication number: GB2025520A
Application number: GB7921986A
Authority: GB
Original assignee: Xaver Fendt and Co
Current assignee: Xaver Fendt and Co
Priority date: 1978-07-15
Filing date: 1979-06-25
Publication date: 1980-01-23
Also published as: DE2831184A1; FR2430864A1

Abstract

A sound absorbing casing (2) substantially surrounds an engine (1) behind and in front of which are first and second fans (5, 4). The casing (2) serves as a cowling for the fans (5, 4) which convey air forward of the vehicle through openings 6 and a duct (7) to provide a flow of air for cooling the transmission gearing (8), radiator (9), engine (1) and auxiliary engine fittings. <IMAGE>

Description

SPECIFICATION Cooling-air conveying system for internalcombustion engines The invention relates to a cooling-air conveying system for internal-combustion engines, more especially for vehicles, having a fan which conveys the air current through the radiator forwardly into the open air.

German Patent No. 2,411,225 discloses a cladding for the fan of an internal-combustion engine in which the fan wheel is designed as a suction fan which sucks air in from the atmosphere axially through the radiator so that the air is conveyed by way of the internalcombustion engine chamber along the internal-combustion engine back once more into the atmosphere. A disadvantage of this known cooling-air conveying system is the fact that the cooling air which heats up upon passage through the radiator and subsequent sweeping past the internal-combustion engine leads to a heating of the driver's cab, which is undesirable more especially in summer. Furthermore the driver is disturbed by engine noise carried to the cab.

German Patent No. 2,459,486 discloses a cooling-air conveying system in which the cooling air is sucked in by means of a fan through the cladding of the internal-combustion engine chamber and is forced in the direction of travel of the vehicle through the radiator. This type of cooling-air conduction has the advantage that the working noises of the fan no longer pass into the interior of the vehicle. The disadvantage of this arrangement however is the fact that the cooling air sucked in through the radiator substantially circumvents the internal-combustion engine so that the auxiliary units arranged in the immediate vicinity of the internal-combustion engine, such as for example injection pump and fuel lines, are only inadequately cooled with a consequent reduction in the performance of the internal-combustion engine.

To prevent undesirable radiation of sound from an internal-combustion engine it is also known to surround the internal-combustion engine wholly or partially with a noise-damping cladding or cowling. Although this provides an effective insulation of the noise emanating from the internal-combustion engine a resulting disadvantage is that the housing of the internal-combustion engine under the cowling can heat up very severely, whereby the durability of the sound-absorbing material used is considerably reduced.

An aim of the present invention is to provide a cooling-air conveying system for enclosed internal-combustion engines with which an effective cooling of the internal combustion engine as of the fuel supply installation thereof, such as filter, injection pump and fuel lines, is possible, with simultaneously improved sound insulation.

According to the present invention there is provided a cooling-air conveying system for motor vehicle internal-combustion engines, comprising two fans operative to convey air through a radiator of the engine forwardly into the open air, and a casing which in use substantially surrounds the internal-combustion engine is spaced relative to the housing of the internal-combustion engine and serves as a cladding for a first of the fans disposed behind the internal-combustion engine and for a second of the fans disposed in front of the internal-combustion engine.

This measure makes it possible to convey the cooling air in a specifically directed flow past the internal-combustion engine. The resulting reduction in temperature in the space between the internal-combustion engine and the enclosure or capsule, limits the heat loading of the material of the capsule to permissible values. In a particularly advantageous manner, in this respect the necessary duct for the air current is formed by the capsule itself, which thus serves two purposes.By splittingup the overall delivery of air between two fans which are arranged a fairly large spacing from one another a uniform quiescent air current is produced, in which respect the fans needed for this purpose, although the volume of the air conveyed is markedly greater than before on account of the now higher heat abstraction, do not differ in their external dimensions substantially from the fan previously used for this purpose.

With regard to the noises emanating from the fan arranged behind the internal-combustion engine, it is advantageous if the radiator is arranged in front of this fan in the air current. In this case, the radiator then acts as insulation against noise radiated rearwardly from the capsule. Moreover, then the difference between the cooling water flowing through the radiator and the cooling air is the greatest.

The invention will hereinafter be further described by way of example with reference to the accompanying drawing which is a schematic elevation of a tractor incorporating a system in accordance with the invention. The driving motor of the tractor (which tractor is of conventional construction) an internal-combustion engine 1, is accomodated in the front part of the vehicle and together with, auxilliary appliances such as injection pump substantially is surrounded or enclosed by a capsule or cowling 2 formed from sounddeadening material which is open only at the front and rear ends. Provided between the housing of the internal-combustion engine 1 and the walls of the capsule 2 is a sufficiently large gap 3 for cooling air flowing around the internal-combustion engine 1.

A fan 4 is inserted in such a way into the front opening of the capsule 2 that the cap sule 2 provides an outer cladding or ducting for the fan 4. Inserted in the rear opening of the capsule 2 is a fan 5 which is clad in the same way as the fan 4 by the capsule 2. Both fans 4 and 5 are so coordinated to one another in their delivery that at least half of the entire performance to be applied is undertaken by the rear-fan 5.

The cooling air conveyed by the two fans 4 and 5 is sucked in from the atmosphere by way of two cooling-air supply ducts 6 and 7 which unite in front of the fan 5. In this respect, the cooling-air supply duct 6 communicates, as is known directly by way of slots in the lateral cladding of the internal-combustion engine with the free atmosphere, whilst the cooling-air supply duct 7 is conducted, prior to the-uniting with the cooling-air supply duct 7 is conducted, prior to the uniting with the cooling-air supply duct 6, past heat-conditioning surfaces of the gearing 8.

The radiator 9 which is necessary for the internal cooling of the internal-combustion engine 1 is arranged in the cooling-air current in front of the fan 5 at at a point at which the two cooling-air supply ducts 6 and 7 have already united. Arranged in this way the radiator 9 acts as a further sound barrier for noise radiated away from the internal-combustion engine chamber in the direction of the driver's cab of the tractor.

Claims

1. A cooling-air conveying system for motor vehicle internal-combustion engines, comprising two fans operative to convey air through a- radiator of the engine forwardly into the open air, and a casing which in use substantially surrounds the internal-combustion engine is spaced relative to the housing of the internal-combustion engine and serves as a cladding for a first of the fans disposed behind the internal-combustion engine and for a second of the fans disposed in-front of the internal-combustion engine.

2. A system as claimed in--claim 1, in which the radiator is associated with the first fan arranged behind the internal-combustion engine.

3. A system as claimed in claims 1 or 2, in which the delivery of the first fan is equal to our greater than that of the second fan.

4. A system as claimed in any preceding claim in which the first fan is operative to suck air through two cooling-air supply ducts one of which communicates directly with the atmosphere and the other of which lies adjacent heat-conducting surfaces of the transmission gearing of the motor vehicle, which surfaces form part of the walling of said other cooling-air supply duct.

5. A cooling air conveying system for motor vehicle internal conbuction engines, -sub- stantially as hereinbefore described-with reference tor and as illustrated in the -accompanying drawing.