EP0861131B1

EP0861131B1 - Industrial washing-machine

Info

Publication number: EP0861131B1
Application number: EP96935726A
Authority: EP
Inventors: Johnny Johansson
Original assignee: JHV Tekniska AB
Current assignee: JHV Tekniska AB
Priority date: 1995-10-19
Filing date: 1996-10-18
Publication date: 2001-09-19
Anticipated expiration: 2016-10-18
Also published as: EP0861131A1; AU7354296A; SE9503674L; ATE205757T1; SE505487C2; DE69615391T2; SE9503674D0; DE69615391D1; WO1997014515A1

Abstract

An industrial washing-machine (1) comprises a washing chamber (14) for washing workpieces (45). The chamber (14) has an upper chamber opening, side walls and a bottom wall, of which walls at least one has perforations. The washing chamber (14) is arranged on a first conveyor (2). A second conveyor (3) is arranged in parallel with the first conveyor (2) and comprises an endless conveyor belt (24), which has a lower run, whose underside shuts the chamber opening tight. The lower run is held down against the chamber opening by a stationary slide plate (29), which abuts against the upper side of the lower run. The endless belt (24) has perforations and an injection means (31) is arranged in the slide plate (29) for injection of washing liquid into the washing chamber through the perforations of the belt (24), at least one of the conveyors (2, 3) being adapted to drive the washing chamber (14) past the injection means (31).

Description

The present invention relates to an industrial washing-machine according to the preamble of claim 1.
In cutting of metal parts, use is advantageously made of a so-called cutting lubricant which by lowering the working temperatures permits a larger degree of removal and, thus, shorter working times. After the actual working, the finished parts are in many cases washed in a solvent bath, such as a trichloroethylene bath, thereby removing cutting lubricant residues and also remaining chips. For small worked parts, use is sometimes made of baskets, in which the parts are placed to be immersed batchwise in the solvent bath.
A drawback of the above-mentioned batchwise washing with the aid of baskets is that merely immersion in a solvent bath is not enough to remove remaining chips. For the purpose of improving the cleaning effect, agitation, such as stirring, of the bath therefore takes place, but it has still been found difficult to reach a satisfactory result in this manner, especially for complicated parts comprising bores and grooves, in which especially remaining chips but also cutting lubricant residues tend to adhere.
A further disadvantage of the described washing in batches is that it is not very kind to the washed parts, which especially on powerful agitation of the solvent bath are colliding with each other and thus run the risk of being damaged. Both drawbacks hit especially such parts as are located in the very centre of the basket and are, in the shade of the surrounding parts, affected only by the negative consequences of the agitation in the form of impacts on the surrounding parts and not by its positive effects in the form of reinforced lubricant motion.
The two drawbacks mentioned above, together with the restricted possibilities of the above-described washing in batches, of integration in a continuous manufacturing process, have resulted in industrial washing-machines, in which the parts that are to be washed are instead arranged and continuously advanced in an upwardly open chute, extending from a feeding station on one side of the machine, via a washing and drying station, to a discharge station on the opposite side of the machine. The arrangement of a feeding and a discharge station and the continuous advancing of the parts between these stations, as well as the possibility of arranging between these stations a practically closed washing and drying station, in which the parts are flushed with a pressurised washing liquid and from which no unhealthy vapours are emitted, render this type of industrial washing-machine particularly suitable for washing of parts in direct connection with a working machine, such as a multi-operation machine, which together with the washing-machine continuously discharges worked parts which can be directly supplied for mounting or be packed and dispatched.
A drawback of the last-mentioned type of industrial washing-machine is that it is relatively non-flexible, since the chute used must be specially adapted to the washed part to make it possible for this to be advanced through the washing and drying station. Therefore, when changing parts, also the chute must be exchanged, which causes costs both for the new chute and for the time required for dismounting the old chute and mounting the new one. In practice, there is thus no possibility of using the washing-machine for washing a different part, if required.
From US-A-4 327 756 an industrial washing machine is known according to the preamble of claim 1. The washing machine according to this US-patent provides for washing workpieces in a continuous process but is limited to washing only workpieces of the same kind because the lower run of the second conveyor is arranged to hold down the workpieces during washing.
The object of the invention is, on the basis of the deficiencies of the known technical solutions, to provide an industrial washing-machine, which obviates the deficiencies of the known solutions and which in one and the same machine combines the advantages that have still existed in the known solutions.
This object is achieved by an industrial washing-machine according to claim 1.
By accommodating the washing chamber between two conveyors, of which the upper closes the washing chamber, it will in a simple manner be possible to provide a hermetically sealed washing chamber, in which a worked part can be flushed with washing liquid with no risk that the part falls out of the chamber during washing. Moreover, it will be possible to use for the chamber relatively soft materials which will not damage a washed part even if it is not fixed in the chamber during washing and therefore can move therein.
Preferably, also an air supply means is arranged in the first slide plate for injection of air into the washing chamber through the perforations of the belt.
This solution permits in a simple fashion drying of the washed parts in a closed system, from which no emission of washing liquid vapours takes place.
Preferably, also the first conveyor comprises an endless belt, which has perforations and an upper run, which is supported by a second stationary slide plate, which abuts against the underside of the upper run and comprises drainage openings or ducts for draining or sucking out the washing liquid from the washing chamber through the perforations in the belt of the first conveyor, the belts of the two conveyors being driven synchronously.
It will be appreciated that this is the simplest and best solution from many aspects, particularly if the lower conveyor is also used for supplying the parts into the washing-machine and discharging them therefrom.
Besides, the second slide plate preferably has air exhaust openings or ducts for discharging the air injected into the washing chamber through the perforations in the belt of the first conveyor.
It will easily be appreciated that for discharging the drying air it is easiest to choose a solution corresponding to the one for draining or sucking out the washing liquid and to use the perforations in the belt of the first conveyor.
Preferably, an insert, which is adapted to hold the workpieces to be washed, is insertable into the washing chamber.
This solution is especially suited when more than one part should be washed simultaneously in one and the same washing chamber or when very complicated parts are to be washed, which for optimum washing results require a special arrangement relative to the injection means.
Finally, preferably a plurality of washing chambers are fixedly arranged on the first conveyor.
It will be appreciated that such a solution confers many advantages by making it possible, for instance, to supply one part, wash another, dry a third and discharge a fourth, all at the same time.
An embodiment of the invention will now be described in more detail with reference to the accompanying schematic drawings, in which:

Fig. 1 is a side view with certain portions broken away, showing parts of an inventive washing-machine;
Fig. 2 is a corresponding top plan view, also with certain portions broken away;
Fig. 3 is a side view of a detail in a washing chamber;
Fig. 4 is a sectional end view of chamber components according to Fig. 3, and a lateral injection nozzle connected thereto;
Fig. 5 is a top plan view with certain portions broken away, showing part of a wall portion of a washing chamber; and
Fig. 6 is a sectional side view of a single washing chamber and an insert arranged therein, and two parts to be washed inserted into the insert.

The industrial washing-machine 1 shown in Figs 1 and 2 comprises a lower or first conveyor 2 and an upper or second conveyor 3.
The lower conveyor 2 is formed as a belt conveyor, whose belt 4 is clamped between two rollers 5, 6, of which at least one is operable both clockwise and anticlockwise according to Fig. 1. The upper and lower runs 7, 8 of the belt 4 are horizontally arranged, and between the two rollers 5, 6, the underside of the upper run 7 abuts in a slidable manner against a metal sheet 9 which is also horizontally arranged. The metal sheet has a width corresponding to the width of the belt 4 and is included as an upper wall in a parallelepipedal box 10 which by means of a pipe socket 11 is connected to a suction member (not shown).
As is evident from Fig. 2, both the belt 4 and the metal sheet 9 have perforations, the perforations 12 of the belt 4 having a relatively small diameter and the perforations 13 of the metal sheet 9 having a relatively large diameter.
In the embodiment illustrated, the belt 4 is divided into a plurality of washing chambers 14. These are parallelepipedal and integrated with the belt 4 and have a chamber opening 15, side walls 16, 17, 18, 19 and a bottom wall 20, of which walls the bottom wall 20 is perforated (the previously mentioned perforations 12).
For driving the belt round the rollers 5, 6, the side walls 16, 18 extending in parallel with the travelling direction of the belt 4 are sectioned, i.e. they consist of wall slats 16', 16" ..., 16ⁿ and 18', 18", ..., 18ⁿ, respectively. When the washing chambers 4 are horizontally arranged, the wall slats engage tightly with each other by means of groove and tongue members 21, 22, which, seen from above (Fig. 5), are slightly bevelled for reduction of friction.
In the illustrated embodiment, the individual washing chambers 14 are spaced apart by a groove 23, which is formed in the upper side of the wall between two neighbouring chambers 14. As is evident, the wall is formed of the side walls 17, 19 of two juxtaposed chambers, the side walls preferably being made in one piece. This is, however, as the expert will realise, possible only if the wall thickness is not too great.
The side walls 16, 17, 18, 19 of the chambers 14 have, especially when the belt 4 travels over the horizontal metal sheet 9, exactly the same height and thus constitute a plane which is parallel with the metal sheet 9.
The above-mentioned upper conveyor 3 is also formed as a belt conveyor, whose belt 24 is clamped between two free-running rollers 25, 26. The upper and lower runs 27, 28 of the belt 24 are horizontally arranged, and between the two rollers 25, 26, the upper side of the lower run 28 abuts in a slidable manner against a stationary, horizontally arranged slide plate 29. The slide plate 29 has a width corresponding to the width of the belt 24, which in turn is identical with the belt width of the lower conveyor 2.
As shown in Fig. 2, the belt 24 has perforations 30, the size of which corresponds to that of the perforations 12 in the belt 4. The slide plate 29 comprises two tubular members 31, 32, which extend transversely of the slide plate 29 and the belt 24 and whose underside is flattened and arranged flush with the underside of the slide plate 29. The underside of the tubular members 31, 32 is formed with apertures 33, 34, which in the longitudinal direction of the tubular members 31, 32 are arranged to match the perforations 30 in the belt 24. The tubular members 31, 32 have closed ends and are connectible by means of tube-coupling nipples 35, 36 to a pump (not shown), which under high pressure feeds a cleaning liquid, such as trichloroethylene, to a compressor (not shown) which emits pressurised drying air.
The slide plate 29 has a length which essentially corresponds to the distance between the two rollers 25, 26 and is arranged in parallel with the metal sheet 9. Together with the metal sheet 9, the slide plate 29 forms a nip, whose opening corresponds to the space required by the belt 4 and chamber 14 of the lower conveyor 2 and the belt 24 of the upper conveyor 3 in vertical as well as horizontal direction. In the nip, the slide plate 29 holds the belt 24 down in sealing engagement with the flat upper side of the chambers 14 of the subjacent belt 4 by means of a pressure pad 37, which is filled with a pressurised fluid or with compressed air and acts on the upper side of the slide plate 29 by a very uniformly distributed pressure, which is adjustable by regulating the pressure of the fluid or air.
The rollers 25, 26 of the upper conveyor 3 are, as mentioned above, free-running, i.e. they have no drive means of their own. Therefore, the belt 24 is instead driven by the lower belt 4 by means of a tooth arrangement (Figs 3, 4). This comprises a toothed strip-shaped sealing strip 38, 39 along each of the two longitudinal edges of the belt 24 and a corresponding sealing groove 40, 41 each in the upper side of the side walls 16, 18 of the washing chambers, the two sealing strips 38, 39 and the sealing grooves 40, 41 besides serving in lateral direction to seal the chambers.
While the sealing strips 38, 39 serve to drive as well as to seal, other projections formed on the belt 24 of the upper conveyor 3 only serve to seal. In respect of these projections, beads 42, 43 (Fig. 4) are involved, which are semicircular in cross-section and extend in the longitudinal direction of the belt and transversely thereof, respectively. The longitudinal beads 42 are arranged on the inside of the belt 24 precisely opposite the sealing strips 38, 39 and engage sealingly but slidably with corresponding recesses 44 in the slide plate 29, and the transverse beads 43 are arranged in the longitudinal direction of the belt at such a distance that they sealingly engage in the above-mentioned groove between or in the chamber walls 17, 19.
The above-described industrial washing-machine 1 comprises a plurality of spaced-apart washing chambers 14, which are arranged on an endless belt 4. Since this is longer than the superimposed belt 24 which is adapted to close the washing chambers 14, the washing chambers 14 are easily accessible both before and after the belt 4 for unimpeded supply and discharge of parts 45 to be washed.
The parts 45 can either be arranged separately in a washing chamber 14 of their own or according to Fig. 5, for instance, in pairs in an insert 46, which is specially adapted to the washed part 45 and supports this in a manner which is advantageous for achieving a desirable cleaning result. Thus, there are different inserts 46 for different parts 45, but suitably all inserts 46 still have the same outer dimensions adapted to the size of the washing chamber 14.
In the above-described embodiment, the washed part 45 is flushed only from above through the belt 24. Preferably, also injection means, however, are arranged at the sides of the chambers 14 and also under the chambers 14 in the metal sheet 9.
The injection means under the chambers can have the same appearance as the above-described tubular members 31, 32 and will therefore not be described in more detail.
The injection means arranged at the sides of the chambers 14 preferably comprise a nozzle 47, which is arranged centrally in one of the above-mentioned wall slats 16', 16", ..., 16ⁿ and 18', 18", ..., 18ⁿ and opens, on the outside of the slat, into a projection 48 which is undercut in a dovetailed manner. The projection 48 is adapted to engage, slidably in the longitudinal direction of the belt 4, with a correspondingly dovetailed rail 14 which is adapted, when passing a projection 48, to inject a dose of pressurised washing liquid into the nozzle 47 and, thus, the chamber 14.
In the above-described industrial washing-machine 1 according to the invention, the two conveyors 2, 3 always operate synchronously with one another and preferably continuously at a steady speed in the feeding or travelling direction indicated by arrow 50. It will be appreciated, however, that there is nothing to prevent, for instance when washing and drying, short stops from being put into the feeding in order to achieve a satisfactory result, also in particularly difficult cases. Also the supplying and discharging of parts 45 on the same side of the upper conveyor 3 is, of course, possible but requires the travelling direction to be reversible.

Claims

An industrial washing-machine comprising at least one washing space for washing workpieces, said space being arranged between a first conveyor (2) and a second conveyor (3), which is in parallel with the first conveyor (2) and comprises an endless belt (24) having a lower run (28), whose underside shuts said space, an injection means (31) being arranged for injecting washing liquid into the washing space through perforations (30) in said belt (24), at least one of the conveyors (2, 3) being adapted to drive said space past the injection means (31) for washing said workpieces, characte rised in that the washing space is a chamber (14) having an upper chamber opening (15), side walls (16, 17, 18, 19) and a bottom wall (20) which has perforations (12), that the lower run (28) of the endless belt (24) is held down against the chamber opening (15) by a first stationary slide plate (29), which abuts against the upper side of the lower run (28) and has a greater width and length than the chamber opening (15), and that the injection means (31) is arranged in the slide plate (29).
The industrial washing-machine as claimed in claim 1, characterised in that an air supply means (32) is arranged in the first slide plate (29) for injecting air into the washing chamber (14) through the perforations (30) of the belt.
The industrial washing-machine as claimed in claim 1 or 2, characterised in that the first conveyor (2) comprises an endless belt (4) having perforations (12) and an upper run (7), which is supported by a second stationary slide plate (9), which abuts against the underside of the upper run (7) and has drainage openings (13) or ducts for draining or sucking out the washing liquid from the washing chamber (14) through the perforations (12) in the belt (4) of the first conveyor, the belts (4, 24) of the two conveyors being driven synchronously.
The industrial washing-machine as claimed in claim 3, characterised in that the second slide plate (9) comprises air exhaust openings (13) or ducts for discharging the air injected into the washing chamber (14) through the perforations (30) in the belt (24) of the first conveyor.
The industrial washing-machine as claimed in any one of claims 1-4, characterised in that an insert (46), which is adapted to accommodate the workpieces (45) to be washed, is insertable in the washing chamber (14).
The industrial washing-machine as claimed in any one of claims 1-5, characterised in that a plurality of washing chambers (14) are fixedly arranged on the first conveyor (2).