GB2115917A - Testing device for engine cooling - Google Patents

Abstract

A testing device for testing engine cooling systems which include coolant flow passages normally operating at above atmospheric pressure, comprises a cap 10 or other closure member which releasably fits and seals with an opening in the coolant flow passages and includes an overload device 24 to restrict the maximum pressure in the passages. A non-return valve 13 is incorporated into the cap to introduce pressurised air to the passages and the valve has means for releasably connecting a source of air to the valve. In one form of the invention (Fig. 1) the device is directly connectable to the opening of a vehicle radiator. In another arrangement the device fits to a vehicle expansion bottle either directly (Fig. 2) or through an adaptor (Fig. 3). <IMAGE>

Description

SPECIFICATION Testing device for engine cooling system This invention relates to a testing device for engine cooling systems and in particular for testing cooling systems for leakages.

Conventionally vehicle cooling systems are fitted with a cap on the radiator and the cap has a pressure release device should the system become overpressurised. Alternatively vehicle cooling systems have an expansion bottle or tank to obviate periodic topping up with water. Normal expansion and contraction of the coolant is accommodated in the bottle which is sealed from atmosphere by a pressure release valve in a cap fitted in the bottle. Such a cooling system does not have an overflow pipe nor a conventional radiator pressure cap but pressure testing is still desirable as part of the routine servicing of the system.

An object of the invention is to utilise the radiator or bottle cap facility for pressurising the cooling system to test for leakage in the system.

According to the invention a testing device for engine cooling systems including coolant flow passages in which the coolant is normally at above atmosphere pressure during engine running, comprises a cap or closure member arranged to be releasably fitted to an opening in the coolant passages, the cap or closure element normally sealing the coolant flow passage from the atmosphere and including an overload device whereby upon the pressure in the passages exceeding a predetermined level the device operates to restrict the maximum pressure in the passages, the cap or closure element further including a non-return valve having connection means for releasably connecting a source of pressurised air to the valve whereby air may be introudced into the passages to pressurise the passages to said predetermined level.

In one arrangement the cooling system has a heat exchanger including an opening to which the cap or closure element is releasably attachable.

In another arrangement the cooling system has an expansion container from which coolant can pass to a heat exchanger and the container has an opening to which the cap or closure element is releasably attachable. In this arrangement the cap or closure element may include a vacuum release valve whereby upon a lower than atmospheric pressure arising in the contianer, air is drawn into the container.

Alternatively the device may include an adaptor member releasably secured to the expansion container, the cap or closure member being releasably securable to the adaptor member.

Preferably the non-return valve includes a valve body extending through the cap or closure member whereby an inlet at one end of the body having the connection means extends from one side of the member and externally of said passages in use, the other end of the body including an outlet in communication with the coolant flow passages in use, and the valve body incorporating non-return valve means whereby air can only pass from the inlet to the outlet.

Conveniently the connection means includes an externally screw-threaded portion to which an air pump or air supply line is attachable.

Further features of the invention appear from the following description of various embodiments of the invention given by way of example only and with reference to the drawings, in which: Fig. is a longitudinal part sectional view of a testing device, Fig. 2 is a longitudinal sectional view of another form of testing device, Fig. 3 is a longitudinal sectional view of an adaptor for use with the device of Fig. 1,and Fig. 4 is a perspective view of the adaptor of Fig. 3 fitted to a vehicle expansion bottle.

Referring to Fig. 1 of the drawings, a device for fitting to the conventional opening of a heat exchange radiator of a vehicle cooling system is shown and includes a cap element 10 generally of the form which fits to the radiator opening (not shown) and disc - shaped having a peripheral turned over rim 11 and a dished central portion 12. In the centre of the dished portion 12 is fitted a non-return or inflation valve 13, which, in this case, is a cycle valve. The valve 13 includes a body 23 which has at one end, the air inlet end, a dust cap 14 and a cap retainer nut 15 fitting an externally screw-threaded portion of the valve body. The valve body 23 passes through an opening 22 in the central portion 12 of the element 10 so that limited relative movement between said body and the element can take place, the nut 15 limiting the extent of said movement.At its other, air outlet end, the valve 13 is secured to a base member 17. A sleeve 18 around the body 23 engages the member 17 at one end and the retaining nut 15 at the other end. A sealing member 19 is located by a headed portion 20 of the valve body which engages the member 19 to locate the member relative to the valve body 23. The member 19 engages with and seals against the radiator opening in use.

A compression spring 24 is located around the valve body 23 between the cap element 10 and the base member 17 to provide an overload device whereby the testing device will release any excess pressure in the radiator to atmosphere when the pressure exceeds a predetermined level determined by the form of spring 24 employed.

Release of excess pressure in the radiator is achieved by the pressure in the radiator, when it overcomes the rated resistance of the spring 24, causing the seal 19 to be unseated from the opening and moved with the base member 17 towards the cap element 10, the sleeve 18 and valve body 23 moving through the opening 22 during such movement.

The screw-threaded portion of the body 23 at said air inlet end of the valve is arranged for releasable connection to a source of pressurised air for example the adaptor of an air pump, such as a foot or cycle pump, or the air supply line from a compress ed air reservoir.

In carrying out pressure testing of a radiator and associated cooling system for leakage, the device can be quickly fitted to a radiator opening in place of the normal cap. Air under pressure can then be introduced into the radiator and cooling system at a pressure which may be of the order of 15 Ibs per square inch whereupon any leakage is made apparent by escape of air and water either from the radiator and especially from flexible hose connections between the radiator and engine. Any air at excess pressure admitted into the radiator is relieved by the action of the overload device so that damage to the system is avoided. After testing the device is removed and the normal cap replaced on the radiator.

Referring nowto Fig. 2 an alternative form of testing device is shown suitable for fitting directly to a vehicle cooling system expansion bottle (not shown in Fig. 2) when present. In this arrangement the device includes a moulded plastics cap 35 which is screw - threaded at 36 to be releasably secured to the conventional screw - threaded opening of the expansion bottle having a seal 37 to achieve the necessary sealing engagement. The cap 35 defines an internal space 38 having a partition 39 on one side 39A of which the space communicates with the interior of the expansion bottle, the other side 39B of which partition is in direct communication with atmosphere through an opening 40 in the top of the cap.

The spaces 39A and 39B intercommunicate through valves 42 and 43, valve 42 being a pressure release valve and valve 43 being a vacuum release valve. The valve body 42A of valve 42 includes openings 44 into the space 39A whereby pressure air in the expansion bottle enters the body 42Ato act on a spring - loaded valve member 45, a spring 46 being so tensioned to enable the valve member 45 to be unseated from an opening (not seen) in the valve body 42A communicating with space 39B when the pressure in the expansion bottle exceeds a predeter mined value.

Similarly the vacuum release valve 43 includes a valve body 43A having openings 47 into the space 39B. A spring - loaded valve member 48 is held by a spring 49 in sealing engagement with an opening (not seen) in the valve body 43A communicating with space 39A. Thus when the pressure in the expansion bottle falls below a predetermined value air is drawn through the valve 43 from atmosphere.

The partition 39 carries the valve bodies 42A and 43A and has a central opening in which is secured a non - return valve 50. The valve 50 includes a valve body 51 in which is located a non - return valve means (not shown) which may take any convenient form. The valve body 51 has at one end 52 an air inlet and said end 52 is formed with an external screw thread whereby a source of pressurised air may be releasably attached to the body 51. The body 51 passes through the opening 40 and is spaced therefrom to define an annular inlet into the space 39B from the atmosphere.

The other end 54 of the valve body 51 is the air outletfrom which pressurised air is released into the space 39A and hence into the expansion bottle. The end 54 of the body 51 is secured to the partition 39 by means of a head portion 55 at one side of the partition and sealed thereto by a seal 56 and a nut 57 at the other side of the partition 39.

It will be appreciated that the testing device of Fig.

2 may be permanently secured to the expansion bottle whereby pressure testing of the associated cooling system may be effected at any time simply by attaching a source of pressurised air to the inlet end of the valve 50. During a pressure testing operation the pressurised air is introduced through the valve 50 until the rated pressure of the system is reached whereupon the valve 42 will operate to prevent an excess pressure build up in the system during testing.

Referring now to Figs. 3 and 4 an adaptor is shown which is suitable for fitting to vehicle cooling systems incorporating an expansion bottle, using the testing device of Fig. 1. Thus the device described in relation to Fig. 1 is fitted to an adaptor 25 which is adapted to be fitted to an expansion bottle 26 of a 'sealed' cooling system employing such a bottle 26. The adaptor has a neck member 27 in a form similar to neck members as fitted to cooling systems employing conventional filler caps, and the member 27 having an outwardly directed flange 28.

The neck member 27 is engaged by a device as shown in Fig. 1. The neck member 27 is secured to a body member 30 which is formed with an internal screw thread 31 at one end which is dimensioned to be screwed onto the neck of the expansion bottle 26.

The body member 30 also has an outwardly directed flange 32 the outer surface of which is knurled to provide grip for when the member is being screwed on and off the bottle.

The member 30 is soldered or otherwise secured to the neck member 27 to seal and unite the two members together.

For testing cooling systems having expansion bottles the cap of the expansion bottle is removed and the adaptor 25 is secured on the bottle in its place and the test device of Fiy.1 is then fitted onto the adaptor and used as previously indicated.

As will be appreciated effective leakage testing can be quickly carried out for detecting leaks which would not be otherwiseapparentfrom inpection of the stationary vehicle, even with the engine running, but which can cause considerable loss of water or develop into large leakswhen the vehicle is being driven especially at high engine speed with the cooling system operating at full pressure.

Leakage testing by the device can be quickly carried out during vehicle servicing or whenever a leak is suspected e.g. during a stop for refueling at a service station.

As will also be apparent from the foregoing the device can be inexpensively produced by adapting standard components for use as the cap element 10 and the inflation valve 13, although if desired a specially constructed cap andlor inflation valve may be employed e.g. for specialised applications.

Although primarily intended as a device for use in servicing or testing radiators and engine cooling systems of motor vehicles, it is also capable of use in carrying out pressure testing of radiators during their manufacture.

Claims (9)

1. Atesting device for engine cooling systems including coolant flow passages in which the coolant is normally at above atmospheric pressure during engine running, comprising a cap or closure element arranged to be releasably fitted to an opening in the coolant flow passages, the cap or closure element normally sealing the coolant flow passages from the atmosphere and including an overload device whereby upon the pressure in the passages exceeding a predetermined level the device operates to restrict the maximum pressure in the passages, the cap or closure element further including a non return valve having connection means for releasably connecting a source of pressurised air to the valve whereby air may be introduced into the passages to pressurise the passages to said predetermined level.

2. A testing device according to claim 1 wherein the cooling system has a heat exchanger including an opening to which the cap or clusure element is releasably attachable.

3. A testing device according to claim 1 wherein the cooling system has an expansion container from which coolant can pass to a heat exchanger and the container has an opening to which the cap or closure element is releasably attachable.

4. Atesting device according to claim 3 wherein the cap or closure element includes a vacuum release valve whereby upon a lower than atmospheric pressure arising in the container, air is drawn into the container.

5. Atesting device according to any one of the preceding claims wherein the non - return valve includes a valve body extending through the cap or closure member whereby an inlet at one end of the body having the connection means extends from one side of the member and externally of said passages in use, the other end of the body including an outlet in communication with the coolant flow passages in use, and the valve body incorporating non - return valve means whereby air can only pass from the inlet to the outlet.

6. Atesting device according to any one of the preceding claims wherein the connection means includes an externally screw - threaded portion to which an air pump or air supply line is attachable.

7. Atesting device according to any one of the preceding claims wherein the overload device includes a base member resiliently urged towards sealing engagement with said opening and carrying the body of the non - return valve, and a cap element through which the non - return valve body extends, the base member being movable towards the cap element against said resilient bias under pressure overload conditions and the valve body being movable relative to the cap element.

8. Atesting device according to claim 3 comprising an adaptor member releasably securable to the expansion container, the cap or closure member being releasably securable to the adaptor member.

9. Atesting device forenginecooling systems substantially as described with reference to Fig. l, Fig. 2, or Figs. 3 and 4.