GB2095767A - Measuring apparatus for injection pumps - Google Patents

Abstract

A measuring apparatus for testing injection pumps comprises a drum 3 which is designed as a polygon and on which are arranged measuring glasses 5. The number of measuring glasses per drum corresponds to the number of measuring operations. A plurality of drums 3 are arranged one behind the other in accordance with the number of injection nozzles. The filling of the measuring glasses 5 takes place via an injection jet trap 7 which has two chambers of which the last chamber has a collar and a filter. Thus, the injection jet arrives in the measuring glasses 5 air-free. The entire apparatus permits a very rapid testing of injection pumps. <IMAGE>

Description

SPECIFICATION Measuring apparatus for injection pumps STATE OF THE ART The invention originates from a measuring apparatus according to the preamble to the main claim. Measuring apparatuses for injection pumps are already known in which the measuring jet is conveyed through an injection jet trap directly into the measuring glass. In order to provide an accurate measuring result time must elapse with the known apparatus until air included in the injection liquid has escaped from the liquid. Only then is the measuring result readable. After the measuring, the measuring glass is inverted and the injection liquid flows out. In order to guarantee a correct measuring sequence, time must elapse until the measuring glass is completely drained.

Such measuring apparatuses have the disadvantage that a long time elapses between the measuring of two injection pumps. Thus, fewer injection pumps can be measured.

ADVANTAGES OF THE INVENTION As opposed to this, the apparatus in accordance with the invention comprising the characterising features of the main claim has the advantage that the measurement proceeds really rapidly and a quicker measuring cycle is therefore possible.

By arranging the measuring glasses on a drum, one section of the measuring glasses can be drained whilst further measuring glasses are already being filled. Due to the construction of the injection jet trap there is a guarantee that the injection liquid arrives in the measuring glasses free of air so that they are readable directly.

Advantageous further developments and improvements of the apparatus set forth in the main claim are made possible by the measures set forth in the sub-claims. It is of particular advantage to so design the drum as a polygon that the number of sides of the polygon correspond to the number of measuring regions. A hexagonal or square formation has proved to be especially preferable since with this arrangement there is sufficient time available for the glasses to drain. If a plurality of injection ducts are to be measured, then it is preferable to arrange a plurality of polygons in series and to arrange for them to be rotatable together.Then each injection duct can be tested simultaneously. in order to provide a definitive measured quantityforfilling the measuring glasses it is advantageous to provide a jet discharge which can preferably be switched in in accordance with the stroke operations of the injection pumps. Furthermore, it is favourable to fix the measuring glasses on the rotatable polygon in an exchangeable manner so that fresh measuring glasses of other volumes or damaged measuring glasses can easily be exchanged.

The injection jet trap preferably has a first collecting chamber provided with an overflow by which the injection liquid arrives in an outer collecting chamber provided with a jet collector. In that way the injection liquid loses a large part of its air content. This apparatus may be improved by providing the outer collecting chamber with a collar which acts similarly to a syphon. Further air bubbles may be held back in the outer collecting chamber by means of a filter. In order to prevent a further air inclusion, the outer collecting chamber likewise has an overflow which is connected to the jet collector. The overflows are preferably ventilated so that discharging gas can escape. The filter in the outer collecting chamber is preferably arranged between the collar and the chamber wall. Thus, further fixing means are not required.A simple construction is produced when the connection between the first collecting chamber and the outer collecting chamber is provided by a cavity with an annular cross-section.

The injection jet trap is preferably arranged above the rotatable polygon so that the injection liquid can flow directly into the measuring glasses.

In order to prevent a fresh intake of air by the injection liquid, it is preferable to arrange the measuring glasses slighly inclined in the filling position. In that way, the liquid jet from the injection jet trap strikes the outer wall of the measuring glass so that a fresh air inclusion is prevented. The polygon and the number of glasses arranged on the polygon is preferably so selected that it corresponds to the number of measuring regions. Furthermore, it is an advantage for the number of glasses and injection jet traps arranged in an horizontal direction to correspond to the number of injection ducts of the injection pumps to be tested.

DRAWING An embodiment of the invention is illustrated in the drawing and is described in detail in the following specification. Figure 1 shows a side view of the apparatus according to the invention, Figure 2 is a front view of the apparatus according to the invention and Figure 3 is a preferred form of the injection jet trap.

DESCRIPTION OF THE EMBODIMENT In Figure 1 the measuring apparatus is illustrated from the side. A drum 3 formed as a polygon on a carrier 2 is arranged in a housing 1.

The drum 3 is mounted on a shaft 4. In the embodiment, the drum is made hexagonal.

However, the drum can also be made square, triangular or octagonal according to its use.

Holders 6 to which are fixed measuring glasses 5 are arranged on each side of the drum. The measuring glasses are of different volumes according to the value to be measured. The measuring glasses are rotated below the injection jet trap 7 by the drum. A jet discharge 8 ensures that the jet liquid is discharged through a tube 9 onto the floor of the housing 1. Only during the measuring operation is the jet discharge 8 pivoted away so that the injection quantity is collected in the measuring glasses 5.

For measuring, the jet discharge is pivoted away during a predetermined number of strokes of the piston of an injection pump (not shown). The quantity of liquid collected by the injection jet trap 7 during this period flows through a jet collector 25 in the injection jet trap 7 into the measuring glass. Preferabiy, in so doing, the measuring glass is not upright below the injection jet trap but the drum inclines the measuring glass somewhat towards the front. Thus, the liquid does not strike the base of the measuring glass but rather the upper edge of the measuring glass and runs from there onto the base of the measuring glass. In that way, additional air is not admixed with the injection liquid.After a certain running time of the injection pump the jet discharge is pivoted forwards once again so that any further injection liquid discharges onto the floor of the housing. The drum is then slightly further rotated so that the measuring glass 5 stands upright. The level of the measured liquid can then be easily read off. The other measuring glasses 5 make it possible to test the injection pump under different load conditions and working conditions. For this purpose, a fresh measuring glass is swung below the injection jet trap by the drum 3. The previously required measuring glass is pivoted away downwardly so that the next measuring sequence can be carried out. After a further rotation of the drum 3, the measuring glass is directed with its opening towards the housing 4, so that the liquid in the measuring glass runs out and can also be drained.

The injection liquid leaves the housing 1 through the outlet opening 10.

The measuring operations can then be carried out continuously. After measuring, the measuring glass is simply pivoted away downwards and after further rotation is emptied. Whilst a fresh measuring is carried out, there is time available so that the measuring glass can be completely emptied.

Figure 2 shows a front view of the apparatus according to Figure 1. Once again, the housing 1 and the outlet opening 10 located in the floor of the housing are visible. The drum 3 on which the measuring glasses 5 are located is mounted on the shaft 4. Six injection jet traps 7 are provided which are for conveying injection liquid into measuring glasses 5. Thus, six injection ducts can be tested simultaneously with the illustrated apparatus. The shaft 4 is driven, for example, by a step-by-step mechanism (not shown).

Injection pumps for a six cylinder engine, for example, can be tested by the illustrated arrangement. The measuring apparatus can be altered as desired according to corresponding requirements. If only four measuring regions are required, a square drum, for example, is suitable. If injection pumps for four cylinder engines are to be tested then the arrangement of four parallel injection jet traps 7, with which corresponding measuring glasses are associated, is sufficient.

The size of the measuring glasses is determined substantially in accordance with the quantity of injection liquid which is to be expected during the performance of the particular test. By these measures, it is possible to achieve an accurate reading of the injection liquid.

Due to the high pressure present during the injection operation enrichment of the injection liquid with air, which settles in the measuring cylinder as oil foam, cannot be avoided. If it is desired to prevent oil foam forming in the measuring cylinder then an appropriate form of injection jet trap 7 is of advantage. An embodiment of an injection jet trap 7 is illustrated in Figure 3. The injection jet trap 7 has an inlet opening 1 3 to which is connected a liquid line which leads to the injection pump to be tested.

The liquid arrives through the nozzle 14 in a first collecting chamber 12 which is centrally arranged with respect to an outer collecting chamber. The first collecting chamber 12 is completely filled with injection liquid. An overflow 1 5 is located at the upper edge of the first collecting chamber 12 so that the injection liquid can flow through a cavity 1 7 to the outer chamber 1 8. The overflow 1 5 is ventilated by ventilation bores 1 6. The cavity 1 7 is produced by inserting in an outer cylindrical vessel, which forms the outer chamber at its lower part, a further cylindrical vessel of smaller diameter which forms the first collecting chamber 12.Radial bores 21, through which the liquid can arrive in the outer chamber 1 8, are located at the lower end of the cavity 1 7. The outer chamber 1 8 has a filter 1 9 which is arranged between the chamber wall and a collar 20. The collar 20 is made cylindrical and has the effect of a syphon.

The outer chamber 18 has a further overflow 23 which is likewise ventilated by a ventilation tube 24. The overflowing injection liquid arrives in the jet collector 25 which conveys it to the corresponding measuring glasses. The jet discharge 8 can also be seen at the lower edge of Figure 3.

The injection quantity delivered by the injection pump and brought in through the inlet opening 13 and the nozzle 14 is collected in the first collecting chamber 12 until the latter overflows. The quantity of liquid collected in the said chamber serves as a damping volume for the liquid arriving in the chamber at high pressure. The overflowing injection liquid flows along the outside of the first chamber 12 downwards through the cavity 17 and fills the outer chamber 1 8 through the radial bores 21. Air which escapes from the first chamber 12 or the oil foam 22 which escapes into the cavity 1 7 can arrive at the outside through the ventilation bores 1 6. Lighter oil foam and smaller air bubbles which arrive in the outer chamber 1 8 are held back and broken up by the filter located between the collar and the outer wall as well as by the collar 20 projecting into the outer chamber 1 8.

Air bubbles which may still be present are discharged through the ventilation tube 24. Thus, only bubble-free injection liquid arrives through the overflow 23 in the jet collector 25 so that only bubble-free injection liquid arrives in the measuring glass. The measuring result can be read off immediately in the measuring glasses, there is no waiting time until the foam has dissolved in the injection liquid and even reading errors no longer exist. Oil is used as an injection liquid in the normal manner.

The measuring apparatus, especially the housing 1 and the drum 3 together with the measuring glasses 5 as well as the injection jet trap 7 can be designed as regards their dimensions completely as desired in accordance with requirements.

Claims (17)

1. A measuring apparatus for testing injection pumps comprising an injection jet trap and measuring glasses into which the injection jet can be conducted, characterised in that, the measuring glasses are fixed at the edge of at least one drum rotatable in a vertical direction and that a respective measuring glass is rotated below an injection jet trap by the drum.

2. Measuring apparatus according to claim 1, characterised in that, the drum is formed as a hexagon, square or triangle.

3. Measuring apparatus according to claim 1 or 2,- characterised in that, a plurality of drums are arranged in a row and are rotatable together.

4. Measuring apparatus according to one of claims 1 to 3, characterised in that, a jet discharge is provided.

5. Measuring apparatus according to one of claims 1 to 4, characterised in that, the measuring glasses are exchangeably fixed to the rotatable drum.

6. Measuring apparatus for testing injection pumps comprising an injection jet trap and measuring glasses into which the injection jet can be conducted, especially according to one of claims 1 to 5, characterised in that, the injection jet trap has a first collecting chamber provided with an overflow and the injection liquid is conveyed through an outer collecting chamber to a jet collector.

7. Measuring apparatus according to claim 6, characterised in that, the outer collecting chamber has a collar.

8. Measuring apparatus according to claim 6 or 7, characterised in that, the outer collecting chamber has a filter.

9. Measuring apparatus according to one of claims 6 to 8, characterised in that, the outer collecting chamber has an overflow to which is connected the jet collector.

10. Measuring apparatus according to one of claims 6 to 9, characterised in that, the overflows are ventilated.

11. Measuring apparatus according to one of claims 8 to 10, characterised in that, the filter is arranged between the collar and the chamber wall of the outer collecting chamber.

12. Measuring apparatus according to one of claims 6 to 11, characterised in that, the connection between the first collecting chamber and the outer collecting chamber is provided by a cavity having a circular annular cross-section.

1 3. Measuring apparatus according to one of claims 1 to 12, characterised in that the injection jet trap is arranged above the rotatable drum.

14. Measuring apparatus according to one of claims 1 to 13, characterised in that, the measuring glasses arranged on the drum are slightly inclined in the filling position.

1 5. Measuring apparatus according to one of claims 1 to 14, characterised in that, the number of measuring glasses arranged on the drum corresponds to the number of measuring operations.

1 6. Measuring apparatus according to one of claims 1 to 15, characterised in that, the number of the horizontally arranged measuring glasses and of the injection jet traps corresponds to the number of injection pump ducts to be tested.

17. Measuring apparatus for testing injection pumps substantially as herein described with reference to the accompanying drawings.