FR2571440A1 - ELECTRONIC MODULE STRUCTURE AND ITS ASSEMBLY ON THE DISTRIBUTOR OF INTERNAL COMBUSTION ENGINES - Google Patents

Abstract

THE STRUCTURE OF ELECTRONIC MODULE 4 CONSISTS OF A METAL BODY 5-7, ACTING AS A THERMAL RADIATOR AND WHICH IS FIXED TO BODY 1 OF THE IGNITION DISTRIBUTOR THROUGH A THERMAL INSULATION SUPPORT. THE TEMPERATURE OF THE MODULE IS NOT INFLUENCED BY THAT OF THE DISTRIBUTOR AND, THANKS TO THE RADIATOR BODY 5-7, IT IS MAINTAINED AT A LEVEL COMPATIBLE WITH THE OPERATING TEMPERATURE OF ITS COMPONENTS. APPLICATION OF THE MODULE BY MOUNTING ON AUTOMOTIVE VEHICLE IGNITION DISTRIBUTORS FOR BETTER TEMPERATURE REGULATION AVOIDING THERMAL SHOCKS OF ELECTRONIC COMPONENTS.

Description

The present invention relates to an electronic module structure

  and its mounting on the ignition distributor of combustion engines

  internally, particularly those of motor vehicles.

  It is well known that in electronic ignition

  biles, the electronic module constitutes the control device of the ignition coil. For this purpose, it is electrically connected, on one side to the switch of the distributor and, on the other, to the coil and the battery of the vehicle. One of the problems with the design of electronic modules is to avoid their excessive warming, which would

  damage to the electronic components that constitute them.

  To keep warming within acceptable limits, the provisions

  classic sitifs were made on metal plate mounted on a

  metal bracket for the purpose of dissipating the heat of the module. The con-

  electrical connection of the module to the distributor is then carried out by means of

a cable.

  However, such a solution supposes the presence of a support for

  tightening and a connecting cable whose presence leads well

  obviously problems of cost and size.

  In order to eliminate the special support and the cable, the object of this

  The invention is to propose the direct mounting of the module on the

  tor. In this case, the metal plate of the module is in contact with the body of the distributor, which then acts as a dissipating support for

heat.

  Nevertheless, in practical operation, the body of the distributor is warmed by the engine-thermal on which it is mounted and the

  direct contact between the metal plate of the module and the body of the

  scorer therefore creates a heat passage from the dispenser to the module,

  so that the temperature of the latter depends not only on the warming

  not only its electronic components but also the warming

of the distributor.

  In practice, the module is actually maintained at the same temperature as

  the distributor. For the time being, if this condition does not present any

  as long as the vehicle is running, thanks to the natural ventilation which ensures sufficient cooling of the distributor and therefore of the module, it is no longer acceptable when the vehicle is stopped with the engine

  on, especially after a highway or hill climb.

  In fact, the temperature of the private ventilation distributor can reach because of "heat stroke", very high peaks incompatible with

  electronic components of the module.

  The object of the present invention is to provide a module structure for electronic ignition and its mounting on the ignition distributor which eliminates the aforementioned drawbacks, whatever the con-

  use of the vehicle and the operation of the engine.

  In particular, the object of the invention is to make the temperature and temperature gradients of the module independent of those of the distributor,

  keeping the temperature at levels compatible with its components

electronic health.

  According to the invention, the aforementioned object is achieved by means of an electronic module structure consisting of a metal body having functions

  radiator, so as to dissipate the external heat of the

  generated by the electronic components of the module and by fixing such a structure to the body of the ignition distributor by means of a thermal insulating means, so as to eliminate the direct transfer of heat

  of the engine through the valve body.

  According to a very simple embodiment of the invention, the radia-

  is in the form of an open box whose interior is partly occupied by the electronic components of the module and available in

  part for electrical interconnections.

  Preferably, the thermal insulating means is formed of a frame-shaped support which defines a closure face of the inner side of the body

  radiator, so as to provide protection of the module.

  The advantages and later characteristics of the module structure and

  of its montage will be evident from the description of the

  illustrated by drawings of one of the embodiments

presented in a non-limiting way.

In the accompanying drawings,

  FIG. 1 is a schematic side view of an ignition distributor.

  mage partially cut at the point of connection with the electronic module,

  FIG. 2 is a sectional view of the dispenser of FIG.

  FIG. 3 is a sectional view of the external side of the module. FIG. 4 is a view of the module of FIG. 3 on the side of the terminal contacts. FIG. 5 is a sectional view of the internal side of the module. Fig. 6 is a sectional view along line VI-VI of Fig. 5; Fig. 7 is a diagram showing the temperature curve in degrees;

  of the distributor body, the body of the

  and the ambient temperature as a function of time in minutes when the vehicle is moving, and Figure 8 shows the same diagram when the vehicle is moving.

in other conditions.

  In the ignition distributor shown diagrammatically in FIGS. 1 and 2, which is assumed to be mounted on an automobile combustion engine, reference numeral 1 indicates the cylindrical body normally made of aluminum, reference 2

  0 the dispensing cap and the mark 3 the impeller which can be n '"im-

  door which known type, for example magnetic (magnetic impeller),

  mechanical (interrupter) or Hall effect.

  Par 4 is indicated the electronic module comprising, according to the invention,

  a container or metal body 5, whose subject is an agent of dis-

  thermal persion, for example aluminum, which is connected to the body 1 of the

  dispenser through a thermal insulating material.

  The body 5 has the shape of an open box with at least a part

  external area provided with cooling fins 7.

  The inside of the box 5 is occupied in part, see 8, by the components

  3 electronic components of the module, and the other part, see 9, is available

  for electrical interconnections 10.

  The electronic components of the module are embedded in a mechanical protection resin with which they form a mass 11 filling

the hollow 8 of the box.

  The terminal contacts 12 of the module are connected, on one side, to the

  blower 3 by the conductors 13 and, on the other hand, to the electrical installation

  of the vehicle by the conductors 14, and in particular to the coil

  ignition and the battery pack (not shown).

  The function of the electronic module is well known. It develops the phase signal 0 which is transmitted to it by the impeller 3 and interrupts the passage

  current in the coil at the instant of ignition.

  To make it easier to access the part 8, the body 5 has on the bottom a lateral opening 16 which will be closed by a wall of material

  insulating 6, as will be seen later.

  : 5 The box-shaped body 5 and the part 11 are mounted together with

  the open side on the body 1 by means of a small plate 6 which constitutes

  kills the thermal insulating means interposed between the body 1 and the module 4.

  In this way, the heat of the dispenser can not be transmitted by

  conduction to the module, so that the temperature of the module is practically

  o independently from the distributor in any

  operating condition of the engine and the vehicle.

  Obviously, in order to satisfy these conditions, both the thickness and the material are suitably selected, for example a polyester

  thermosetting, for insulating plate 6.

  Not influenced by the heating of the dispenser, the module 4 will have a temperature that will depend solely on the warming of its electronic components.

  To ensure that such warming remains within

  the radiator body 5 is provided with cooling fins 7,

  O10, the area of which will be used for the dissipation of heat is

  calculated to guarantee such conditions.

  Plate 6 also has the function of defining an area of protection

  the electronic part of the module or the closing of the hollow

8 and 9.

  In a simplified embodiment, the plate 6, as seen in FIGS. 1 and 2, has the shape of a frame whose edge, on one side is in contact with the body i of the distributor, and on the side opposite, with

  the inner edge of the radiator body 5.

  The frame makes it possible to have a free space 15 between the body 1 and the module 4 (see FIG. 1), which, besides making it easier to insert and connect the conductors 13 and 14, creates an air cushion between the distributor and the module capable of braking the transfer

  of heat between the different parts.

  In addition, to make it easier to access the box 9 during opera-

  above mentioned, the radiator body 5 has an opening

  16 or bottom aperture which, after mounting the module on the dis-

  tributor, remains closed by the wall 17 in the form of a plate pro

  In this way, the inside of box 5, and parti-

  Part 9 is protected against any splashing of water, foreign bodies, etc. In Figures 3 to 6, the module 4 is presented as a unit in itself, ie separate from the distributor. In these drawings, the corresponding elements

  are indicated with the same numerical references.

  The mounting of the module 4 on the body of the dispenser by means of the insulating frame 6 can be achieved in any way, for example by means of nails, screws, etc. In FIGS. 1 and 2, an assembly is shown by means of the screws 17, of the frame 6 on the body of the distributor and, by means of screws 18, of the body of the module.

on the frame 6.

7144 Q

  All practical tests to verify the thermal behavior of the electronic module produced and assembled in accordance with the invention have

been made.

  During these tests, the distributor with the annex module was mounted on the engine of a vehicle running at ambient temperature of 30 C. The results of these tests are illustrated in the diagrams of FIGS. 7 and 8, in which the curves A- A ', BB' and CC 'respectively show

  the evolution as a function of time of the temperature of the body 1 of the

  tor, the body 5 of the module and the ambient distributor, that is to say

the atmosphere below the engine.

Diagram of Figure 7.

  These are temperature readings from a moving vehicle

  on highway at maximum speed and after stop 28 minutes after departure.

  It is immediately noted that the curve B representing the temperature of the body 5 of the module 4 is, both during walking and after stopping the vehicle, always below the curve A. Before stopping, the body temperature 1 (see curve A) does not exceed C; this is due to the natural ventilation produced by the moving vehicle. But, after 28 minutes of walking, when the vehicle stops, curve A is suddenly raised due to "heat stroke" which manifests itself in the body of the dispenser following the cessation of ventilation and heat transferred by the engine. In

  this phase, the temperature of the body 1 reaches and exceeds 120 C.

  With the arrangements suggested by the invention, which provide on one side the thermal insulation of the module 4 of the distributor body by means of the frame 6, and on the other hand an effective dissipation of the heat of the module using the finned body 5, the curve B, as noted in the diagram, is maintained below the curve A of 25 to 30 C, also

  well when the vehicle rolls only after stopping.

  In addition, the thermal gradient observed on the module in the beginning phase of the "heat stroke" (rise slope of the curve B with respect to the curve A) is significantly lower than that which would result on the module

  directly applied to the distributor.

  These lower temperature and thermal gradient effects allow

  to obtain a significant profit on the reliability in operation of the com-

electronic components of the module.

  In the diagram, we also show the curve C which represents the evolution

  the temperature of the box, where is housed the distributor.

71440

Diagram of Figure 8.

  These are temperature readings taken on a vehicle during a

  mountainous course with maximum load and after stop.

  Note that in this case also the curve B 'is always below the curve A', even if the temperature values are higher compared to those of the curves A and B of the diagram of FIG. 7, because of the harsh driving conditions of the vehicle and ventilation

  reduced motor due to low speed. This justifies the thermal rise

  after stop, which concerns the curves A 'and C' and

  Thus, the adaptation of the curve B 'to the curve C' is faster.

Claims (6)

CLAIMS.   1. Electronic module structure and its mounting on an ATM distributor   ignition of an internal combustion engine, particularly for motor vehicles, characterized in that the structure consists of a metallic body (5) functioning as a heat radiator which is fixed to the body (1) of the distributor by means of a means ( 6)   thermal insulation, said radiator being able to dissipate to the outside   the heat generated by the electronic components of the module (11).   2. Electronic module structure according to claim 1, characterized in that at least a part of the surface of the radiator body (5)   has the outer side of the cooling fins.   3. Electronic module structure according to claim 1 or 2, characterized   characterized in that the radiator body has the shape of an open box whose interior is partly (8) occupied by the electronic components of the module (11) and partly (9) available to house   electrical interconnections (10).   4. Electronic module structure according to claim 3, characterized in that the box has a lateral opening (16) to be able to   access the housing (9) of the electrical interconnections (10).   5. Electronic module structure according to one of claims 1 to 3,   characterized in that the thermal insulating means-consists of a plate (6) which defines a protective area on the inner side of the body containing the module (11).   6. Electronic module structure according to claims 4 and 5, characterized   characterized in that the plate is in the form of a frame (6) having a protruding wall (17) for closing the lateral opening (16) of the box-shaped body and providing a free space (15) between   the distributor body (1) and the module (11).