AU779307B2

AU779307B2 - Tank for a system for injection supply of LPG for internal-combustion engines

Info

Publication number: AU779307B2
Application number: AU33009/02A
Authority: AU
Inventors: Mario Ricco
Original assignee: Centro Ricerche Fiat SCpA
Current assignee: Centro Ricerche Fiat SCpA
Priority date: 2001-04-13
Filing date: 2002-04-10
Publication date: 2005-01-13
Anticipated expiration: 2022-04-10
Also published as: AU3300902A

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: C.R.F. Societa Consortile per Azioni Actual Inventor(s): Mario Ricco Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: TANK FOR A SYSTEM FOR INJECTION SUPPLY OF LPG FOR INTERNAL-COMBUSTION

ENGINES

Our Ref: 666207 POF Code: 192558/291744 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1- 6006a "Tank for a system for injection supply of LPG for internal-combustion engines" TEXT OF DESCRIPTION The present invention relates to systems for injection supply of LPG for internal-combustion engines.

The invention relates in particular to a system for injection supply of LPG, of the type comprising a hollow structure having a top opening closed by a service flange that carries means for the hydraulic and electrical connections of the tank to the fuel-supply system.

Tanks of the type specified above are described, for example, in the European patent EP-B-0 922 851 in the name of the present applicant and in the corresponding US patent US-A-6 050 237.

The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the priority date of each claim of this application.

20 One purpose of the present invention is to simplify the structure of the tank and in particular the structure of the aforesaid service flange. A further purpose is to improve the efficiency of the various parts associated to the tank, with particular regard to the reliability and precision of operation of the levelsensing device.

25 According to a first aspect, the present invention provides a tank for a system for injection supply of LPG for internal-combustion engines, including a hollow structure having a top opening closed by a service flange that carries means for hydraulic and electrical connections of the tank to a fuelsupply system, said means including: a first hole for connection with a pipe for delivery of LPG to injectors of the fuel-supply system; an assembly including a flow-limiting valve and a shutoff solenoid valve, associated to said first connection hole; W:Edn~heiS, wonN'i627 $pS0CoC a second hole for connection with a pipe for flow back into the tank of excess LPG fed to the injectors; a return valve associated to said second connection hole; a solenoid valve for filling of the tank; a safety valve for preventing pressure inside the tank from exceeding a pre-set threshold value; and an electrical connection device, wherein said valve assembly includes the shutoff solenoid valve and the flow-limiting valve, as well as said return valve and said filling valve, each having a structure set entirely underneath the service flange and fixed against the bottom surface of the latter, without having any parts mounted via through holes of the service flange.

Thanks to the above-mentioned characteristics, the structure and conformation of the service flange are extremely simplified as compared to those adopted in the known solutions.

In one embodiment, with a view to achieving the further purpose specified above, the aforesaid sensor device is of a capacitive type and has a structure rigidly connected to the structure of tank, independently of the aforesaid service flange. Thanks to this characteristic, a better precision of the 20 sensor is achieved, without moreover having to resort to the use of a float, unlike the case of known solutions which, instead, do use a sensor with a float.

The said float must in fact be made of a material with a low specific weight, given that the LPG has a specific weight which is approximately one half that of water. Consequently, the case of known solutions the risk arises that the light 25 material of the float may collapse on account of the pressure to which it is e *..subjected, thus reducing in volume. The use of the sensor of a capacitive type according to the invention provides a radical solution to said problem.

Preferably, moreover, also the electrically operated pump which is set inside the tank is rigidly connected to the structure of the latter, unlike what occurs in the case of known solutions, in which the pump is secured to the service flange.

Further characteristics and advantages of the present invention will emerge from the ensuing description, with reference to the attached drawings, which are provided purely by way of non-limiting example and in which: W:TnMhinWh6mni882O7 SPOc.-c Figure 1 is a schematic cross-sectional view of a tank according to the prior art: Figure 2 is a schematic cross-sectional view W:WEtn~otMSh&fMfl620 1PC~dOC of a tank according to the invention; and Figure 3 is a view at an enlarged scale and partially sectioned of a detail of an embodiment of the tank according to the invention.

In Figure 1, the reference number 1 designates, as a whole, an LPG tank, built according to the prior art, for supplying LPG to a plurality of injectors I associated to the various cylinders of the engine. The tank 1 has a hollow structure 2 made in such a way as to guarantee tightness at the operating pressures envisaged for a system of the type in question. The hollow structure 2 has a top opening closed by a service flange 3 which carries the various connector elements and unions for connection between the tank and the fuel-supply system. For this purpose, the tank 1 built in accordance with the prior art has a first through opening 4 through which is mounted the structure of an assembly 5 connected to a line 6 for delivery of LPG to a distribution manifold or rail 7, which distributes the LPG among the various injectors I. The assembly 5 includes a shutoff solenoid valve 8, which is designed to shut, thus interrupting communication of the tank with the outside environment in pre-determined emergency conditions, as well as a flow-limiting valve 9. The assembly 5 receives the LPG through a line 10 from an electrically operated pump 11, the structure of which is carried, via a connection element 12, by the service flange 3. The pump 11 in turn carries the structure of a sensor device which detects the level of the fuel 13. Electrical supply to the solenoid valve 8, to the pump 11, and to the sensor 13 is guaranteed by an electrical connector 14, which is mounted by means of a through opening of the service flange 3. The latter moreover has a through opening 16, inside which there is mounted an assembly 17, which includes two valves 18, 19.

The valve 18 is a return valve, which is connected to a line 20 for reflow into the tank of the excess LPG supplied to the rail 7. The valve 19 is the valve used for filling the tank and is associated to a further level sensor 21. Also associated to the flange 3 is a safety valve 22, which prevents the pressure inside the tank from exceeding a predetermined threshold value.

".."Figure 2 is a schematic illustration of how the tank is modified according to the invention. In Figure 2, the parts in common with those illustrated in Figure 1 are designated by the same reference numbers.

The main difference with respect to the solution illustrated in Figure 1 lies in the fact that the assembly 5, the valve 18 and the valve 19 (which in this case are mounted in separate positions) each present a structure entirely set beneath the service flange 3 and fixed against the S"bottom surface of the latter. In particular, in the case of the example illustrated, the assembly the valve 18 and the valve 19 have respective attachment flanges 5a, 18a, 19a which are fixed by means of screws (not illustrated) to the flange 3.

In positions corresponding to the said elements, then, the flange 3 has only connectors 40, 160A, 160B, and the said elements are not mounted via through openings of the flange as, instead, may be seen in the case of Figure 1. The mounting that may be seen in Figure 1 remains unaltered only as regards the safety valve 22 and the electrical connector device 14, since for the said elements this type of installation cannot be avoided.

According to a further characteristic of the invention, the level sensor, designated by 130 in Figure 2, is for example a capacitive-type sensor and has a structure rigidly connected to the pump 11, which in this case is in turn connected to the bottom wall of the tank 2, to the advantage of the operating precision of the sensor.

Figure 3 is a cross-sectional view of a practical embodiment of the service flange 3, of the valve 19 and of the assembly 5. In this case, each of said elements has a resting surface S"pressed against the bottom surface 3a of the S•service flange 3, with interposition of an O-ring by means of screws 60 which are screwed in S"threaded holes made in the flange 3 and have their heads resting against plates 70 that press the structures of the aforesaid elements against the bottom surface of the flange 3.

Of course, without prejudice to the principle of the invention, the details of construction and the embodiments may vary widely with respect to what is described and illustrated herein purely by way of example, without thereby departing from the scope of the present invention.

Claims

2. A tank according to claim 1, wherein set inside the tank is an 25 electrically driven pump the structure of which is fixed to a bottom wall of the structure of the tank.
3. A tank according to claim 1 or 2, wherein said tank includes within it a level-sensor device of a capacitive type, the structure of which is rigidly connected to the tank structure.
4. A tank according to claim 3, wherein said capacitive sensor is carried by the structure of the pump. W:%EonwunShmn88O7 speroC 8 A tank substantially as hereinbefore described with reference to the embodiment illustrated in Figures 2 and 3. Date: 18 June, 2004 Phillips Ormonde Fitzpatrick Attorneys For: C.R.F. Societa Consortile per Azioni Wi.EIWQUWUA5Swm,~84827 00ee.