GB2262277A - Improvements in engine test monitoring systems. - Google Patents

Abstract

An automated oil sampling apparatus comprises pumping means 42 for removing oil from an engine at preselected intervals; measuring means 46 in fluid communication with said pumping means, for measuring a predetermined quantity of said removed engine oil; and dispensing means 48, in fluid communication with said measuring means, for dispensing said measured quantity of oil into a sample container. An oil levelling system and an exhaust gas emmission monitoring apparatus are also described. <IMAGE>

Description

Improvements in Engine Test Monitoring Systems This invention relates to improvements in engine test monitoring Systems.

It is common to test engines in order to evaluate the effectiveness of a particular type of engine oil. This testing can be carried out for many hours and under high rpm running conditions. During such testing it is necessary periodically to take a sample of the engine oil for analysis. Also, due to the fact that engine oil is being regularly removed, and consumed by the engine it is necessary to ensure that the oil level in the engine remains at a constant level; this is known as "oil levelling. Exhaust emissions from the engine may also need to be analysed.

The oil samples are usually taken manually by an operator. This requires the operator to work in close proximity to the engine and to handle fluids which may be at temperatures well over 150 centigrade.

The efficiency and safety of engine oil testing operations would be considerably improved if the sampling and levelling of the oil could carried out automatically.

According to one aspect of the invention there is provided an automated oil sampling apparatus which comprises: pumping means for removing oil from an engine at preselected intervals; measuring means, in fluid communication with said pumping means, for measuring a predetermined quantity of said removed engine oil; and dispensing means, in fluid communication with said measuring means, for dispensing said measured quantity of oil into a sample container.

Advantageously, the measuring means comprises a piston and cylinder arrangement. This has the advantage that the cylinder can be dimensioned to a specific size related to the predetermined quantity of oil, while the piston can act as a pump to pump the oil to the dispensing means.

The dispensing means preferably includes an on/off valve which is actuated after the measuring means has filled with oil. The dispensing means may also include a nozzle through which the oil can be dispensed to the sample container. The sample container may be a simple PYREX bottle. It is preferred that the nozzle is movable between two positions: a sample position and a dump position. The nozzle is kept in the dump position when a sample is not being taken so that extraneous drops of oil from the nozzle do not contaminate the sample.

Desirably the dispensing means further comprises a rotatable support (eg a carousel-type arrangement) containing a plurality of said sample containers arranged in a circular manner about the rotational axis of the support. The rotatable support may be caused to rotate after a sample has been taken in order to place an empty sample container under the sample position of the nozzle.

The rotatable support may be provided with a weighing mechanism to weigh each sample container either during sampling, or after the sample has been taken: this ensures that the correct quantity of sample has been taken. It is preferred that the sample is weighed during sampling. To this end, the rotatable support may be provided with an aperture which receives the weighing device and on which the sample container rests. When a sample is taken, the support may be lifted by the weighing device to facilitate weighing and to cause the nozzle to be disposed inside the container; this helps to prevent splashing of the oil being dispensed.

The pumping means may comprise a conventional pump, such as a metering pump.

In a preferred construction the pumping means, the measuring means and the dispensing means are disposed in an oil flow line which extends from a withdrawal point on the engine to a return point on the engine. Oil can be withdrawn from the engine at the withdrawal point and can be returned to the engine at the return point. It is desirable that the pumping means, the measuring means and the dispensing means are disposed sequentially in the oil flow line, with the pumping means being closest to the withdrawal point. This arrangement enables a steady flow of oil to be maintained through the oil sampling apparatus and back to the engine before a sample is taken; this helps to ensure that the oil sample is truly representative of the oil in the engine; and it also ensures that the measuring means is full of oil before dispensing begins.

Preferably an on/off valve valve is disposed between the withdrawal point and the pumping means. An on/off valve is desirably disposed between the pumping means and the measuring means, and between the dispensing means and the return point.

The oil sampling apparatus preferably includes an electronic controller which can monitor the sampling operation and shut down the engine in the event that a potentially unsafe situation develops. Examples of such situations include: overfilling of sample containers; dispenser nozzle out of correct position; measuring means piston out of correct position; pressure increased due to blocked oil flow line; sample container missing; and power loss.

According to another aspect of the invention there is provided an automated oil levelling apparatus for maintaining a preselected oil level in an engine, comprising: monitoring means for monitoring the oil level in an engine; an oil reservoir; measuring means in fluid communication with the oil reservoir, for measuring a predetermined quantity of oil; and pumping means, in fluid communication with the measuring means for pumping the measured oil to the engine.

Advantageously the pumping means comprises an air supply at higher pressure than the oil in the measuring cylinder, and which is applied to an inlet of the measuring cylinder to pump the oil from the measuring cylinder to the engine. This method of pumping helps to avoid contamination of the fresh oil.

The oil levelling apparatus preferably includes an oil flow line which extends from the reservoir to the inlet of the measuring means and from an outlet of the measuring means to the engine; preferably the oil flow line also extends from the outlet of the measuring means back to the reservoir. The pumping means may be disposed in the oil flow line between the reservoir and the inlet of the measuring means. A further pumping means (which may be a conventional pump such as a metering pump) is preferably disposed in the oil flow line between the outlet of the measuring means and the reservoir. The purpose of the additional pump and the oil flow line from the outlet of the measuring means to the reservoir is to enable the oil to be circulated through the measuring means back to the reservoir in order to ensure that the measuring means is properly filled.

On/off valves may be disposed in the oil flow line between the reservoir and the pumping means; between the measuring means and the engine; between the measuring means and the further pumping means; and between the further pumping means and the reservoir.

According to another aspect of the invention there is provided an automated apparatus for monitoring exhaust gases from an engine, which comprises a manually operated exhaust gas instrument which has been modified to enable the controls to be software operated. This enables the gas samples to be taken automatically and emulates the following functions: purge instrument with clean air; zero instrument; span instrument; measure contents of exhaust gas sample; and reset instrument to standby. A Horiba Mexa 201-GE instrument is suitable for such modification.

All the above three apparatus can be combined in a single unit which will perform all three functions. When the oil sampling apparatus is combined with the oil levelling apparatus the pumping means for the sampling apparatus may be the same as the further pumping means for the levelling apparatus. In this embodiment a purge air supply can be connected to the oil flow line of the levelling apparatus between the further pumping means and the reservoir. This purge is activated before the measuring means of the levelling apparatus is filled, to remove oil from the coincident parts of the two apparatus in order to avoid cross contamination.

The entire system, or any part thereof may be driven and controlled by a programmable logic controller. Such controllers have the ability to communicate with an engine test host computer.

Reference is now made to the accompanying drawing which is a schematic flow diagram of an oil sampling apparatus and an oil levelling apparatus according to the invention.

Referring to the drawing an engine 10 contains engine oil 12. The oil sampling system will be described first.

The oil sampling apparatus includes oil flow lines 14 (which is connected at one end to a wihdrawal point 10a on the engine 10), 16, 20, 22, 24, 26, 30, 32 (which is connected at one end to a return point 10b on the engine 10) and 34. An on/off valve 36 is disposed between lines 14 and 16; an on/off valve 38 is disposed between lines 22 and 24; and an on/off valve 40 is disposed between the lines 26 and 30.

Pumping means in the form of a metering pump 42 is disposed between the lines 16 and 20. The pump 42 circulates oil through the oil flow lines 14-34.

Measuring means in the form of a piston 44 and a cylinder 46 is disposed between the lines 24 and 26; the capacity of the cylinder is preselected to be a particular value, typically 50 ml.

Dispensing means is provided which comprises an on/off valve 48 connected to line 34, a nozzle 50, a plurality of sample bottles 52 (of which only one is shown), and support 54, which is rotatable about an axis 56. The support 54 is sub-stantially circular in the plane normal to the axis 56, and the bottles 52 are arranged thereon in a circular arrangement. The line 34 communicates with the line 26.

The nozzle 50 has two positions 58 and 60 indicated by the dotted lines. When in position 58 the nozzle 50 can dispense oil into one of the sample bottles 52; when in position 60 the nozzle 50 can dispense oil into a dump 62.

The oil levelling apparatus will now be described. It includes the lines 14, 16, 20 and 32, together with the on/off valve 36 and the pump 42 of the sampling apparatus. It also includes a line 64 which joins with line 16 and extends to an on/off valve 66. A line 68 joins the line 64, and is connected at its other end to an on/off valve 70. A line 72 connects a purge air supply 74 to the on/off valve 70.

A line 76 connects the on/off valve 66 to an inlet of an oil reservoir 78. The reservoir 78 has an outlet which is connected to an on/off valve 82 via a line 80. The on/off valve 82 is, in turn, connected to a measuring cylinder 84 by a line 86. A line 88 joins the line 86, and is connected at its other end to an on/off valve 90. A line 92 connects a clean air supply 94 to the on/off valve 90.

The air supplies 74 and 94 may be identical.

The measuring cylinder 84 is connected to a line 96, which joins a line 98. The line 98 connects two on/off valves 100 and 102. The on/off valve 100 is connected to lines 20 and 22 via line 104, while the on/off valve 102 is connected to the lines 30 and 32 via line 106.

The operation of the oil sampling apparatus will now be described. Initially all valves are closed and the nozzle 50 is in position 60. Valves 36, 38 and 40 are then opened and pump 42 pumps fluid from engine withdrawal point 10a to engine return point 10b. After a predetermined peroid of time (sufficient to clear the oil flow lines of any previous oil and to fill measuring cylinder 46) valves 36, 38 and 40 are closed and the pump 42 is stopped. At this time the measuring cylinder contains 50ml of oil. Nozzle 50 is now moved to position 58, and valve 48 is opened. Piston 44 is driven towards the outlet of the cylinder 46 (leftwards in the drawing) to expel oil therefrom through the nozzle 50 into bottle 52. When the movement of the piston 44 is complete, the nozzle moves back to position 50, the valve 48 is closed and the piston 44 is drawn back to its rightmost position.During dispensing the sample bottle 52 is lifted and weighed by a weighing mechanism (not shown).

If the sample size desired is 50ml, then the support 54 is rotated about the axis 56 until the next bottle 52 is in position. If a multiple of 50 ml is required (100ml, 150ml, 200ml, etc) then the sample bottle 52 remains in position and the sampling method is repeated.

Samples are taken automatically, at predetermined intervals, throughout the operation of the engine. The system is completely automatic (and therefore economical and safe) because no human input is required until all the sample bottles 52 have been used.

The operation of the oil levelling apparatus will now be described. It should be noted that the oil levelling apparatus does not operate when the sampling apparatus is taking a sample.

The level of oil in the engine is continually monitored by sensors (not shown) and when the level reaches a predetermined value the oil levelling apparatus is activated. Initially all valves are in the closed position. Upon activation the valves 70, 100 and 102 are opened to flush the lines 16, 20, 22, 64, 104, 98, 106 and 32 with air to remove oil which may remain from the sampling operation. Valves 70, and 102 are then closed, while valves 66, 82 are opened; pump 42 is activated to pump oil (anticlockwise) from the reservoir 78 through the measuring cylinder 84 and back into the reservoir 78.

This is carried out for a sufficient period of time to ensure that the measuring cylinder 84 is full. At this point the valves 66, 82 and 100 are closed and the pump 42 is turned off. The valves 90 and 102 are then opened so that high pressure air pumps the oil from the measuring cylinder 84 to the engine 10 via lines 96, 98, 106 and 32. If the engine oil level is still too low then the cycle is repeated until the level is correct.

Claims (16)

1. An automated oil sampling apparatus which comprises: pumping means for removing oil from an engine at preselected intervals; measuring means, in fluid communication with said pumping means, for measuring a predetermined quantity of said removed engine oil; and dispensing means, in fluid communication with said measuring means, for dispensing said measured quantity of oil into a sample container.

2. Apparatus according to claim 1, wherein the measuring means comprises a piston and cylinder arrangement.

3. Apparatus according to claim 1 or 2, wherein the dispensing means includes an on/off valve which is actuated after the measuring means has filled with oil.

4. Apparatus according to claim 1, 2 or 3, wherein the dispensing means includes a nozzle through which the oil can be dispensed to the sample container.

5. Apparatus according to claim 4, wherein the nozzle is movable between two positions: a sample position in which the nozzle is aligned to dispense oil into the sample container, and a dump position in which the nozzle is out of alignment with the sample container.

6. Apparatus according to any preceding claim, wherein the dispensing means further comprises a rotatable support containing a plurality of said sample containers arranged in a circular manner about the rotational axis of the support.

7. Apparatus according to claim 6, wherein the rotatable support is provided with a weighing mechanism to weigh each sample container after the sample has been taken.

8. Apparatus according to any preceding claim, wherein the pumping means, the measuring means and the dispensing means are disposed in an oil flow line which extends from a withdrawal point on the engine to a return point on the engine.

9. Apparatus according to claim 8, wherein the pumping means, the measuring means and the dispensing means are disposed sequentially in the oil flow line, with the pumping means being closest to the withdrawal point.

10. An automated oil levelling apparatus for maintaining a preselected oil level in an engine, comprising: monitoring means for monitoring the oil level in an engine; an oil reservoir; measuring means in fluid communication with the oil reservoir, for measuring a predetermined quantity of oil; and pumping means, in fluid communication with the measuring means for pumping the measured oil to the engine.

11. Apparatus according to claim 10, wherein the pumping means comprises an air supply at higher pressure than the oil in the measuring cylinder, and which is applied to an inlet of the measuring cylinder to pump the oil from the measuring cylinder to the engine.

12. Apparatus according to claim 11 or 12, further comprising oil flow line which extends from the reservoir to the inlet of the measuring means and from an outlet of the measuring means to the engine.

13. Apparatus according to claim 13, wherein the oil flow line also extends from the outlet of the measuring means back to the reservoir.

14. Apparatus according to claim 13, wherein the pumping means is disposed in the oil flow line between the reservoir and the inlet of the measuring means.

15. Apparatus according to claim 12, 13 or 14, further comprising a further pumping means disposed in the oil flow line between the outlet of the measuring means and the reservoir, said further pumping means enabling the oil to be circulated through the measuring means back to the reservoir in order to ensure that the measuring means is properly filled.

16. Apparatus according to any of claims 10 to 15, further comprising an automated oil sampling apparatus as claimed in any of claims 1 to 9.

17 Apparatus according to any of claims 10 to 16, further comprising an automated exhaust gas emmission monitoring system.