FR2609111A1 - FUEL HEATING DEVICE FOR DIESEL ENGINES - Google Patents

Abstract

THE INVENTION RELATES TO A FUEL HEATING DEVICE FOR DIESEL ENGINES OF THE TYPE INCLUDING A BODY 2 IN WHICH A FILTER 3 FOR THE FUEL IS MOUNTED. ACCORDING TO THE INVENTION THE DEVICE INCLUDES A CLOSING CAP 4 FOR THE BODY 2, IN WHICH TWO SETS OF PASSAGES ARE PROVIDED, ONE FOR THE FUEL AND THE OTHER FOR THE WATER OF THE ENGINE COOLING CIRCUIT. THIS LATEST SET OF PASSAGES SHOWS A WATER INLET OPENING 5 DIRECTLY CONNECTED TO AN OUTLET 51 OPENING IN A PRESSURE ZONE OF A THERMOSTAT 6 TO ADJUST THE ENGINE COOLING CIRCUIT.

Description

The present invention relates to a fuel heater and

  relates, in particular, to a device for heating diesel oil for diesel engines. It is known that at low temperatures

  the order of +2 to -20 C, a problem arises in the food

  diesel fuel to the diesel engine given the

  paraffin wax in the filter that is mounted in the

  fuel supply circuit. To solve this problem

  It has been thought to increase the temperature of the diesel fuel especially in the vicinity of the filter. A first solution

  consists of using resistance heating devices

  this electric mounted in or around the body of the filter, while a solution is to use the circuit water

  engine cooling and is carried out by means of tu-

  bes who carry the water in the heat exchanger with

  the filter body and are of relatively large length

  of. These two solutions have disadvantages in that the first entails a certain consumption of

  current, typically during low-speed start-up

  while in the second, given the length

  tubes, the water arrives in the vicinity of the filter at a temperature of

  is not very high so that heat exchange with diesel fuel is low, especially

in the initial stages.

  The object of the present invention is to provide

  a diesel fuel heater which will not have the above-mentioned drawbacks and which will provide a compact and integrated installation for the

  heating the fuel in the filter area, using

  water from the cooling circuit of the

  tor. According to the present invention there is provided a fuel heater for diesel engines of the type comprising a body in which a filter is mounted

  for fuel, characterized in that said body comprises

  a hat in which a first set of pas-

  wise for the fuel and a second set of passages for the water of an engine cooling circuit; because of this, there is a heat exchange between said sets of

  passages and said second set of passages having a

  inlet opening directly connected to an opening

  output in a pressure zone of a thermo-

  mostat to control said cooling circuit of the

engine.

  For a better understanding of the present invention, a preferred embodiment is now described, by way of non-limiting example, with reference to the accompanying drawings, in which: FIG. 1 is a partially sectional view of a heater constructed in accordance with the principles of the present invention; Fig. 2 is a partially sectional plan view of the device of FIG. 1; and 3 is a cut taken along the line

IlIl-IlIl of Figure 2.

  As shown in FIG.

  I generally denotes a fuel heater for diesel engines, comprising a filter body 2 inside which is mounted a filter cartridge 3 and which is closed at the top by a cap 4 in which is formed a first passing set for fuel and a second set of passages for circuit water

  engine cooling. This second set of passages

  carries an inlet opening 5 directly connected to a pressure zone of a thermostat 6 (shown in phantom) to adjust the engine cooling circuit. The body 2 of the filter is made of sheet metal

  and has a cylindrical shape. Cormne this was previously

  As described above, in the body 2 is mounted a filter cartridge 3 of known type and which has a generally annular shape since it is surrounded around a hollow support cylinder 7. The cartridge 3 of the filter is cerned at the end by a small plate 8 having a plurality of small holes 11 formed in correspondence with the * cartridge 3 and a central orifice 12 corresponding to the support cylinder

  7. In the lower part of the body 2 is mounted a

  Indicator 13 with a known type electrode which can be actuated to remove the water possibly present in the carousing tD and which is collected in this lower part of the body 2. The upper edge of the body 2 is folded towards

  inside and is attached to a plate 14 having a file

  central stage within the threaded central through hole 15 coaxial with the cylinder 7 and a plurality of small

  orifices 16 formed in a ring corresponding to the car-

  3. An annular seal 17 is mounted between

  the edge of the orifice 15 in the plate 14 and the upper end

  cylinder 7. On the plate 14 is fixed a small

  metal plate plate 18 having an orifice

  central 21 coaxial with the port 15 and a plurality of pegs

  small orifices (not shown for simplification) formed in a ring corresponding to the ring of the orifices 16 formed in the plate 14. Between the edge of the orifice 21 of the small plate 18 and that of the orifice 15 formed in

  the plate 14 is mounted on an annular seal 22.

  The device I for connecting the body 2 of the filter to the cap 4 comprises a hollow cylinder 23 having a

  outer surface divided into upper and lower zones

  re, separated by a projecting annular flange which presents

  an external thread. In use, the inferred area

  the cylinder 23 is screwed into the orifice 15 of the plate 14 and the intermediate projecting rim co-operates with

  the seal 22. The device 1 comprises the

  skin 4, wherein the heat exchanger is mounted between the water and the fuel, and which has a hollow cylinder 25 having upper and lower portions respectively designated 26 and 27 and separated by a partition wall 28. The lower part 26 is threaded inside and screwed on the upper part of the cylinder 23 and clamped on the seal 22. Around the

  lower part 26 of the cylinder 25 is defined an

  nular 31 delimited above by an annular wall 32 of conical cross section and which extends downwardly from the upper portion 27 of the cylinder 25. In a portion of the wall 32 is formed an opening 33 for the inlet fuel. Inside the chamber 31 are formed several radial ribs 35 which extend from below this wall 32. The cap 4 comprises

  furthermore a cylindrical side wall 35 through which

  pass the opening 33 and whose lower edge rests on the small plate 18 with the interposition of a seal

  sealing ring 39 which is placed in a space

  this annular formed in the plate 18 itself.

  Referring to Figures 1, 2 and 3, fuel

  enters the chamber 31 through the opening 33 and from there

  pours the orifices formed in the small plate 18 and the orifices 16 formed in the plate 14 to flow into the cartridge 3 of the filter from which it flows through the orifices 11 formed in the plate 8 and penetrates

  inside the small cylinder 7. From there, he worked

  pours the cylinder 23 to flow inside the

  lower part 26 of the cylinder 25. The part 26 communicates,

  through an inclined duct 36, with a chamber

  37 o is mounted a thermal expansion valve 41, of known type, whose operating characteristics

  will be described below. Part 27 also communicates

  42, with the chamber 37, so that the fuel, from the portion 26, can enter the portion 27 through the conduit 36, the chamber 37

  and conduit 42. Part 27 constitutes the opening of

  of the fuel and for this purpose is threaded internally for a coupling of known type, not shown. The

  ducts 36 and 42 are arranged near the separating wall

28.

  As shown in Figures 1, 2 and 3, above the chamber 31, in the cap 4, is defined an annular chamber 43, bounded below by the wall

  32 and above by a plate 44 fixed on the upper part

  25 of the cylinder 25. In particular, the peripheral edge

  the plate 44 is pressed against the upper edge of the cylindrical side wall 35 and is fixed by a ring 49 of the Seeger type carried by the part 27. In the chamber 43 are provided protrusions 45 which extend upwards to from the wall 32. As shown in FIG.

  2, the projections 45 describe an arc and in particular

  two protrusions 45 extend on the same circumference centered on the axis of the cylinder 25 and a third projection 45 extends on a circumference concentric to that which has just been described but of larger diameter. In addition, this

  last projection 45 is less high than the first two.

  The cap 4 has a substantially cylindrical portion 46

  come form, having a longitudinal axis practically

  at the side wall 35. The two chambers are formed

  in part 46, one of which is room 37 which

  closes the bulb 41, while the other, referenced by 47,

  has the inlet port 5 which is directly connected

  corded (FIG. 1) to the outlet orifice 51 of the thermostat 6.

  More specifically, the water enters through the opening 51 from

  the cooling circuit in a zone under pres-

  if we. In the chamber 47 is further provided an opening 52 for the passage of water from the chamber 47 to the chamber 43. The chambers 43 and 47 are divided by a wall 53 in which is formed a threaded through orifice 59 in which is screwed the externally threaded portion of the

  bulb 41. The latter has a stem, the outer part of which

  The rod 55 is housed in the chamber 47. This rod, as is known, has a length that can vary depending on the temperature of the bulb 41 so that it is sensitive to the temperature of the diesel fuel that surrounds it. The protruding portion 55 acts on a bottom

  57 of a valve-shaped cup 58 which can move

  translate in translation against the action of a prestressed spring 61 which abuts against the bottom 57 and against a plug 62 for closing the chamber 47. In progress

  of use, with higher fuel temperatures than

  for example, at +23 C, the end 55 of the stem

  a progressive longitudinal displacement which allows the valve 58 to move towards the plug 62 so that its side wall 63 progressively closes the opening 52. In the case of lower fuel temperatures, for example, at + 23 ° C, that is to say, during the starting and heating of the motor, the rod of the bulb 41 is removed by disengaging the opening 52 so that the water can pass from the thermostat 6 and flow inside of the chamber 47 and thence inside the chamber 47 and this chamber inside the chamber 43 o it follows a circular path flowing through the projections 45. The water leaves the chamber 43 by an outlet opening 64 formed in the wall 35 of the cap 4 and returns by a central coupling (not shown) to a vacuum zone of the thermostat 6. In the accompanying drawings, the path followed by the fuel is indicated by solid arrows. , while the path followed by the water is in diamed by arrows in

broken lines.

  In use, the fuel follows the

  described above, while the water in the recirculation circuit

  The cooling follows its path only if the opening 52 is open, that is to say, only if the fuel temperature is below a certain value, for example 23 C. In this case, the heat exchanger enters water and the fuel for the progressive heating of the latter is mounted in the cap 4 through the wall 32 which separates the chambers 31 and 43. The presence of the ribs 34 and

  protrusions 45 increases the heat exchange surface and allows

  thus puts a greater efficiency of this exchange. In addition, the projections 45 ensure a circulation of water in the chamber 43 in a predetermined directional direction which

  allows the water to flow over the entire wall 32.

  From what has been described above, the names

  many advantages obtained with the structure of the present invention.

will be obvious.

  In particular, there is provided in the device 1, a heat exchanger for exchanging heat between the water and the fuel in a compact integrated circuit. In addition, it should be noted that the water inlet opening 5 formed in the cap 4 is directly connected, and this, without the aid of

  tubes, at the outlet opening 51 of the thermostat 6.

  to avoid temperature losses in the water

  present, therefore in Chamber 43, almost the same

  than when it is withdrawn so that

  the effectiveness of the device is more significant, special-

  in the initial stages of operation of the engine

  in which the temperature of the water is still relatively

  low. The presence of the ribs 34 and projections 45 further allows the heat exchange surfaces to be significantly increased. Moreover, in the same cap 4 is provided the control mechanism for closing and opening the

  circulation of water which is directly sensitive to the temperature

  diesel fuel, thus avoiding excessive heating

of it.

  Finally, it is clear that device I describes and

  illustrated here, may have modifications and

  laughing without departing from the scope of this

vention.

Claims (9)

  1. Fuel heating device for   diesel engines, of the type comprising a body (2) in which is mounted a filter (3) of fuel, characterized in that said body (2) comprises a cap (4) in which is mes-   swam a first set of passes for fuel and a se-   cond set of passages for the water of the cooling circuit-   motor, a heat exchange occurring between said sets of passages and said second set of passages   having an inlet opening (5) directly connected   at an outlet opening (51) in a pressure zone of a thermostat (6) for adjusting the engine cooling.   2. Device according to claim 1, characterized   in that, within said cap (4), means (41, 58) are provided for regulating the flow of water through said second set of passages.   3. Device according to claim 1 or 2,   characterized in that said first set of passages comprises a first annular chamber 31 open downwards and   to said filter 3 and in that said second set of passwords   ges comprises a second annular chamber (43) separated from said first chamber (31) by a partition wall (32).   4. Device according to claim 3, characterized   in that said second chamber (43) is provided with a plurality of projections (45) extending towards   the top from said partition wall (32) of   to increase the heat exchange surface.   5. Device according to claim 4, characterized   in that said projections (45) describe at least arcuate sections whose center coincides with the axis   said second chamber (43) so as to define a circular jet for water.   6. Device according to at least one of the claims   3 to 5, characterized in that within said first chamber 31 are formed a plurality of radial ribs 34, so as to increase the heat exchange surface. 7. Device according to claim 2 or one   any of claims 3 to 6 when dependent   of claim 2, characterized in that a part (41)   heat-sensitive means of said circuit adjusting means   water circulation is arranged in an area (37) of said first passing game.   8. Device according to claim 7, characterized   characterized in that said water circulation adjusting means comprise a thermal expansion bulb (41) mounted in a fourth chamber (37) of said cover (4) and an element (58) enclosed in a third chamber (47) and   which can be actuated in translation under the action of a   ge (55) controlled by said bulb (41) against the action of a spring (61) to intercept the flow of water with a portion (63) thereof, said third chamber (47) communicating with said second annular chamber (43) and said water inlet opening (5), and said fourth   chamber (37) being mounted in series with the associated parts   (26, 27) of said first set of passages.   9. Device according to any one of the   cations, characterized in that it comprises temporary coaxial connection means (23) between said body (2) enclosing said filter (3) and said cap (4) and associated external sealing means (39, 22). for the passage of fuel in the different branches said first set of passages.