EP2263834B1

EP2263834B1 - Apparatus for extracting injectors of diesel engines

Info

Publication number: EP2263834B1
Application number: EP10154416.1A
Authority: EP
Inventors: Antonio Verillo; Davide Verillo; Marco Mitrati
Original assignee: Govoni SRL
Current assignee: Govoni SRL
Priority date: 2009-02-27
Filing date: 2010-02-23
Publication date: 2016-06-29
Anticipated expiration: 2030-02-23
Also published as: ITMO20090049A1; ES2593906T3; DE202010018283U1; EP2263834A1

Description

The present invention relates to an apparatus for extracting injectors of diesel engines.
In the field of car repair shop equipment, extractor tools are known which are used to remove the injectors of diesel engines, which are generally accommodated with an interlocking coupling in corresponding seats formed on the casings of such engines, each connected to a corresponding cylinder.
To extract these injectors it is necessary to apply traction, discharging the reaction onto the engine casing.
Single extractor tools are known for performing these interventions which essentially consist of a substantially tubular body which has an end that is adapted to abut against the engine casing and inside which there is a fixed female thread with which an externally threaded shank mates which lies along the axis of the tubular body and has an end that can be connected temporarily to the injector to be extracted and is directed toward such end of the tubular body. The combined rotary and translational motion of the threaded shank is actuated manually by means of the rotation of an actuation nut, which is mated therewith and is arranged against a fixed abutment.
These single extractor tools are not free from drawbacks, which include the fact that if it is necessary to remove a plurality of injectors they must be repositioned in each instance so as to ensure correct supporting of the end of the tubular body on the casing, with consequent increase of the time needed to perform these interventions.
Moreover, in view of the limited maneuvering spaces, if it is not possible to position the extractor tool so as to ensure that the tubular body abuts appropriately against the casing, one runs the risk of damaging such casing or the injector during extraction.
Of course, identifying the correct position of the extractor tool is entrusted to the discretion of the assigned worker and therefore, if such worker has a limited experience, the risk of damage of the involved components increases.
Double extractor tools are also known which substantially consist of a supporting structure provided with two female threads arranged in a fixed position, with which respective externally threaded shanks of the type described above are mated.
However, these double extractor tools are designed to perform interventions on engines that require simultaneous disassembly of a pair of injectors and are sized specifically for these applications; moreover, they still need to be repositioned to disassemble each pair of injectors of the engine, with the drawbacks described above. Injector extractor arrangements, with one or more extractors, are disclosed in documents DE 20 2008012338 U1 and EP 1 797 999 A2 .
The aim of the present invention is to eliminate the drawbacks cited above of known extractor tools, by devising an apparatus for extracting injectors of diesel engines which is multiple, i.e., makes it possible to operate on all of the injectors that are present in the diesel engine being worked on as a consequence of a single positioning operation, so as to reduce the time and costs of such interventions.
Within this aim, an object of the present invention is to ensure correct positioning with respect to the engine being worked on, so as to limit the risks of damage of the involved mechanical parts.
A further object of the present invention is to be flexible in use as the geometric characteristics of the engine being worked on vary.
Another object of the present invention is to have a structure which is simple, relatively easy to provide in practice, safe to use and effective in operation regardless of the experience and skills of the assigned operators, and also has relatively low costs.
This aim and these and other objects which will become better apparent hereinafter are achieved by the present apparatus for extracting injectors of diesel engines, according to the invention, that has the features set forth in claim 1.
Further characteristics and advantages of the present invention will become better apparent from the following detailed description of two preferred but not exclusive embodiments of an apparatus for extracting injectors of diesel engines, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a schematic exploded perspective view of a first embodiment of an apparatus according to the invention;
Figure 2 is a schematic perspective view of the apparatus of Figure 1 in the assembled condition;
Figure 3 is a schematic and partially exploded perspective view of a second embodiment of the apparatus according to the invention;
Figure 4 is a schematic perspective view of the apparatus of Figure 3 in the assembled condition.

With reference to the figures, the reference numeral 1 generally designates an apparatus for extracting injectors of diesel engines.
The apparatus 1 comprises a supporting structure 2, which can be associated with a conventional diesel engine, at least one female thread assembly 3, which is associated with the supporting structure 2, at least one externally threaded shank 4 that is mated with the female thread assembly 3, means 5 for temporarily connecting the shank 4 to an injector during extraction, not shown because it is of a known type, and means for actuating the rotary and translational actuation of the shank 4 with respect to the female thread assembly 3.
In the embodiments shown, the apparatus 1 has a single female thread assembly 3 with a respective shank 4, but it is possible to provide the apparatus with two or more female thread assemblies 3 which are mated to respective shanks 4 to allow simultaneous extraction of two or more injectors.
The supporting structure 2 is adapted to abut against the casing of the diesel engine being worked on in order to discharge thereon the force of reaction to the traction applied by means of the shank 4 on the injector being extracted. The supporting structure 2 can be shaped in various manners depending on the specific geometry of the diesel engine being worked on, so as to optimize the distribution and extension of the areas of contact between the supporting structure 2 and the casing, reducing the risk of damage.
The female thread assembly 3 has a thick washer 6, in the through hole of which there is a seat for accommodating a radial bearing 7, the internal ring of which is provided internally with a female thread which engages the shank 4. There is also a ring 8 for retaining the bearing 7 in its seat.
According to the invention, the shank 4 is associated with the supporting structure 2 with at least one degree of freedom in translational motion along an axis (designated with the double arrow A in the figures) that is transverse and preferably perpendicular to the longitudinal extension of the shank. The shank 4, which is jointly connected for translational motion along the axis A to the female thread assembly 3 with which it is engaged, can therefore vary continuously its working position within a path that lies along such axis.
In practice, the apparatus 1 is arranged so that the axis A is aligned, in plan view, with the direction along which the injectors to be extracted in the diesel engine being worked on are distributed.
The supporting structure 2 has guiding means 9 for the alternating sliding of the shank 4 along such path, which consists of an elongated slot that runs along the axis A and forms such path.
The shank 4 is inserted so as to pass through the slot 9 and the washer 6 is arranged so as to rest slidingly on the peripheral region of such slot.
In greater detail, the supporting structure 2 comprises two strips 10, which are arranged parallel to the axis A and lie on a plane which is perpendicular to the longitudinal extension of the shank 4; the strips 10 are kept mutually spaced by the interposition of two blocks 11 at the mutually opposite ends, so as to form a sort of quadrangular frame that delimits the slot 9. The washer 6 is therefore arranged so as to rest slidingly on the strips 10. The strips 10 and the blocks 11 are assembled to each other by means of connecting screws 12 which are inserted so as to pass through such blocks.
However, possible alternative embodiments of the supporting structure 2 are not excluded which have for example a plate in which the slot 9 is cut directly.
The supporting structure 2 further has first means 13 for resting contact against the casing of the diesel engine being worked on which are arranged in a fixed position.
Advantageously, the supporting structure 2 can have second means 14 for resting contact against the casing of the diesel engine being worked on, which can move along the axis A and are adapted to abut against such casing proximately to the current working position of the shank 4, so as to reduce the stress of the shank and of the injector during extraction.
The temporary connection means 5 can be implemented in different ways depending on the shape of the injector being extracted.
The temporary connection means 5 generally have a male threaded element 15, which is associated with the end of the shank 4 and, during use, is directed toward the diesel engine being worked on and which is adapted to be associated temporarily with a corresponding female thread provided on the injector being extracted. The male threaded element 15 is preferably formed monolithically with the shank 4, consisting of a tang which is threaded at such end.
Moreover, the temporary connection means 5 can have, in addition to or as an alternative to the male threaded element 15, a female threaded element 16, which is associated with the shank 4 and is adapted to be associated temporarily with a corresponding male thread provided on the injector being extracted. In particular, the female threaded element consists of an internally threaded ring 16, which is fitted along the shank 4 proximately to such end.
It is in fact noted that the body of the injector is generally provided with an internally threaded seat for mating with a valve element, which is removed to prepare the injector for extraction, freeing a female thread in which the male threaded element 15 can engage. Moreover, the injector body is usually provided with an externally threaded collar for mating with an electrical connection element, which is removed to prepare the injector for extraction, by clearing a male thread in which the threaded female element 16 can engage.
For differently shaped injectors, the temporary connection means 5 can have, in addition to, or as a substitute for, the male threaded element 15 and/or the female threaded element 16, an element for reversible interlocking connection of the injector associated with the shank 4. Such element, which is not shown, is sized specifically depending on the geometry of the injector being extracted.
Finally, in the illustrated embodiment, the actuation means are of the manual type and consist of an actuation nut 17, which is associated with the shank 4 in a fixed axial position, in abutment against the washer 6.
The figures illustrated two embodiments of the apparatus 1 which differ in terms of the configuration of the first and second resting contact means, respectively 13 and 14, designed in relation to the geometry of the diesel engine being worked on according to methods that are known to the person skilled in the art, so as to ensure the stability of the apparatus 1 during execution of the intervention.
In a first embodiment (Figures 1 and 2), the first resting contact means 13 consist of a pair of feet arranged at the mutually opposite ends of the slot 9 and the second resting contact means 14 provide a foot which is arranged along such slot.
Each foot 13 or 14 consists of a cylinder 18, to the base of which a lamina 19 is fixed which is positioned along the slot 9 and is fixed by means of a screw 20, which enters such cylinder, pressing a perforated plate 21 into abutment against the strips 10.
The foot 14 is moved in each instance along the slot 9 for positioning the respective lamina 19 in abutment against the casing as closely as possible to the injector being extracted.
It is noted that the laminae 19 have different shapes in order to adapt to the geometry of the diesel engine being worked on.
In a second embodiment (Figures 3 and 4), the first resting contact means 13 have a contoured plate 22 which supports the strips 10 at one end of the slot 9 and the block 11 between them.
The second resting contact means 14 have a foot which consists of an abutment element 23, which is arranged along the slot 9 and is fixed by means of a screw 24, which enters such element, pressing a perforated plate 25 in abutment against the strips 10.
The operation of the present invention is as follows.
In use, the apparatus 1, provided with suitable first resting contact means 13 and with optional second resting contact means 14 which are sized and shaped as a function of the geometry of the diesel engine being worked on, is positioned on the casing so that the slot A is superimposed in plan view on the direction along which the injectors are distributed.
To perform the extraction of each injector, the shank 4 is subjected to a translational motion jointly with the female thread assembly 3 along the slot 9, so as to arrange it at such injector (vertically superimposed thereon).
If provided, the movable foot 14 is arranged along the slot 9 proximately to the shank 4.
By operating on the actuation nut 17, with the aid of wrenches or other known tools, the shank 4 is thus screwed onto the female thread assembly 3 so as to move the temporary connection means 5 toward such injector until they engage with it.
By operating on the actuation nut 17 in the opposite direction, the shank 4 is unscrewed from the female thread assembly 3, causing its spacing from the diesel engine being worked on, with entrainment of the injector being extracted.
Once extracted, the injector is freed from the temporary connection means 5 and the apparatus 1 can be used to remove another injector simply by repositioning the shank 4 and the female thread assembly 3 along the slot 9, without the need to reposition the supporting structure 2.
In practice it has been found that the described invention achieves the intended aim and objects, and in particular the fact is stressed that the invention proposes an apparatus which is flexible to use, allows the extraction of a plurality of injectors with minimal downtimes linked to the positioning of the apparatus.
The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.
Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

An apparatus (1) for extracting injectors of diesel engines, comprising: a supporting structure (2) that can be associated with a diesel engine; at least one female thread assembly (3) that is associated with said supporting structure (2); at least one externally threaded shank (4) mated with said female thread assembly (3); means (5) for temporary connection to at least one injector during extraction, which are associated with said shank (4); means (17) for actuating the rotary and translational motion of said shank (4) with respect to said female thread assembly (3), said shank (4) being associated with said supporting structure (2) with at least one degree of freedom in translational motion along at least one axis (A) that lies transversely to the longitudinal extension of said shank, the shank (4) being jointly connected for translational motion along said axis (A) to the female thread assembly (3) and being able to vary continuously the working position within a path that lies on said axis; and guiding means (9) that comprise at least one elongated slot (9) for the reciprocating sliding of said shank (4) along said path, characterized in that said elongated slot (9) runs along said axis (A) and defines said path, said shank (4) being inserted through said slot (9) and said female thread assembly (3) being arranged so as to rest slidingly on the peripheral region of said slot (9).
The apparatus (1) according to claim 1, characterized in that said supporting structure (2) comprises first fixed resting contact means (13), which are adapted to abut against said engine.
The apparatus (1) according to claim 2, characterized in that said supporting structure (2) comprises second resting contact means (14), which can move along said axis (A) and are adapted to abut against said engine proximately to the current working position of said shank (4).
The apparatus (1) according to one or more of the preceding claims, characterized in that said temporary connection means (5) comprise a male threaded element (15), which is associated with one end of said shank (4) and is adapted to be associated temporarily with a corresponding female thread provided on the injector.
The apparatus (1) according to one or more of the preceding claims, characterized in that said temporary connection means (5) comprise a female threaded element (16), which is associated with said shank (4) and is adapted to be associated temporarily with a corresponding male thread provided on the injector.
The apparatus (1) according to claim 5, characterized in that said female threaded element comprises an internally threaded ring (16) that is fitted along said shank (4).
The apparatus (1) according to one or more of the preceding claims, characterized in that said temporary connection means (5) comprise an element for reversible interlocking connection of the injector associated with said shank (4).
The apparatus (1) according to one or more of the preceding claims, characterized in that said actuation means comprise an actuation nut (17), which is associated with said shank (4) in a fixed axial position.