FR2486238A1 - IMPROVEMENTS ON TEMPERATURE-SENSITIVE ELECTRICAL CONTACT DEVICES - Google Patents

Abstract

TWO PUSH-BUTTONS 20, 21 MUST BE RELEASED AT SUCCESSIVE THRESHOLDS OF THE TEMPERATURE OF A FLUID, SUCH AS THE COOLING WATER OF A VEHICLE ENGINE. A SINGLE WAX THERMOSTAT 7, WHOSE CAPSULE 11 IS LICKED BY THIS FLUID, MOVES A SLIDER 28 WHICH CARRIES RAMPS 30, 31 ACTING RESPECTIVELY ON THE PUSHBUTTONS 20, 21.

Description

248623 &

  The subject of the invention is a stepped thermocontact, that is to say an electrical contact device capable of establishing at least two different electrical circuits at successive temperature thresholds, and it relates more particularly but not exclusively, among these

  stepped thermocontacts, those associated with the installation

  engine cooling of a motor vehicle

  bile and are arranged to start at medium vi-

  and at full speed the electric motor of a fan

  depending on whether the vehicle engine temperature reaches

  dyes a first threshold or a second threshold higher than the first. To start at medium speed or full

  speed the electric motor of the fan, use up to

  that here two different thermostatic organs to evaluate

  the two temperature thresholds. It would be better to use

  read, as control parameter, the temperature of the liquid

  cooling system which circulates inside the radiator of the installation. This requires drilling in the box

  water from the radiator, as many holes as there are thermo-

  mostatic. However, it is difficult and expensive to drill such holes. This is the reason why we usually only plan a hole in the water boot right now.

  of the radiator for the adaptation of one of the thermo-

  static, of the wax type, so that this organ measures ef-

  actually the temperature of the coolant while the second thermostatic member is placed in the air stream having passed through the radiator under the effect of the fan. Unlike the first, the second organ

  thermostatic is therefore not directly sensitive to the

  coolant temperature, which causes

  Difficulties in tuning the two thermic organs

  mostatic, in particular according to the latitude (outside temperature) of the place where the motor vehicle is to be used. a

  The object of the invention is to shout / thermocontact

  ge that is sensitive to a single temperature. -The invention also aims to create a stepped thermocontact which only requires drilling a single hole in the water box

  of a radiator, while being sensitive to two different thresholds

  the temperature of the water circulating in this ra-

  diator. To this end, the stepped thermoswitch in accordance with the invention is essentially characterized in that it comprises a case at one end of which is a wax thermostat so that the capsule of this thermostat is located at the outside the case and the thermostat piston more or less penetrates the interior

  of the housing according to the temperature of the cireuso coDi- material

  held in the capsule; in that the housing coeticent a tactor comprising an entry and at least two exits and associated control organs respectively audited exits; in that the input and the outputs of the contactor are respectively connected to connection terminals ac

  transferable outside the shoemaker; and in that a mechanistic

  is interposed between the above piston and the control members so as to actuate successively these members during the movement of penetration of the piston inside

of the bootmaker.

  This gives a stepped thermocontact which does not include

  wears only a wax thermostat, which lowers its price by

returns and facilitates its adjustment.

  Preferably, the body of the contactor is fixed relative to the case and the above mechanism is movable in

  translation inside the case, parallel to the pis-

  tone of the thermostat. It is preferable to constitute the mechanic

  essentially by a slide guided in translation parallel to the thermostat piston and urged by a spring towards this piston. According to an advantageous construction,

  the contactor body is approximately parallel-

  pedic and the slide fits this body so as to be

guided by it.

  When the mechanism is constituted by a coulis-

  bucket, it pays to have him carry two ramps coop-

  respectively with the control elements of the con-

  tactor, the assembly being such that one of the ramps attacks

  one of the controls before the other ramp

  than the other control member, during the output movement of the wax thermostat piston. In accordance with a particularly simple embodiment, the organs of

  contactor control consist of buttons-

  pushers carried by a face of the body which is parallel to the piston of the thermostatic member and the ramps carried

  by the slide are oblique to the axis of the pis-

  your. To facilitate the adjustment of the temperature thresholds, each ramp can be constituted by an elastic blade

  the inclination of which, at the corresponding push button

  dant, is adjustable, in particular using a screw. Finally, it may be advantageous to constitute the elastic blades in one piece with a common bar used to

attach to the slide.

  The invention will now be described in more detail.

  tail using the accompanying drawings.

  Figure 1 shows the motor used to drive the fan of a cooling installation for the

  motor vehicle engine as well as the fuel system

tation of this engine.

  Figure 2 shows in longitudinal section a thermo-

  stepped contact which is associated with the supply circuit of FIG. 1 and which is established according to an embodiment

particular of the invention.

  Figure 3 shows a detail of this thermostat,

  in section along line III-III of Figure 2.

  A cooling system for a motor vehicle engine includes a passing liquid circuit

  by a radiator. This radiator is cooled in case of

  care by a fan which is driven by an electric motor 1. This motor 1 is supplied by a current source (battery) 2, via a contact 3 of the vehicle coupled with the ignition contact of the engine / and either a contact 4 with a resistor 5 in series, or a contact 6 without a resistor 5 in series, both

  contacts 4 and 6 being actuated as a function of the temperature

  at least one point in the cooling system

  is lying. It would also be possible to replace contact 4 with a group of contacts suitable for being closed to

  different temperatures and to put resistors in series

  these of different values. Anyway, when the con-

  tact 6 is closed, motor 1 drives the fan at full speed. When contact 4 (or when one of the contacts in the above group) is closed, motor 1 drives

  the fan at an intermediate speed.

  The object of the invention is to activate the con-

  tacts 4 and 6 using a thermostatic or thermostatic

  single wax mostat 7, so as to constitute a thermocon-

tact layered.

  As shown in Figures 2 and 3, this thermocon-

  tact storied 8 comprises a two-part housing 9 and 10, at one end of which is fixed the wax thermostat 7 so that the capsule 11 of this thermostat 7 is located outside the housing 9, 10 and that the thermostat piston 12 penetrates more or less inside the housing 9, 10 depending on the temperature of the waxy material 13 contained in the capsule 11. A membrane 14 is interposed between the

  material 13 and the piston 12 which is housed in a guide 15.

  In accordance with French patent 78 07432 / 2.420.124, the useful stroke of the piston 12 is preferably at most equal

1.1 times its diameter.

  The case 9, 10 contains a contactor 16 comprising

  both an entrdel7, two outputs 18 and 19 (see also Figure 1) and control elements or pushbuttons

  and 21 (FIG. 3) associated respectively with said outlets

  ties 18 and 19. Contactor 16 includes the two contacts

  4 and 6 of Figure 1 with which are associated respectively-

  the outputs 18 and 19 and the push buttons 20 and 21.

  The input 17 and the outputs 18 and 19 are constituted by conductors which pass through the upper part 9 of the case 9, 10 so as to form terminals for connection to

the outside of the shoemaker.

  Finally, a mechanism which will be described below is interposed between the piston 12 and the push-buttons 20,

  21 so as to successively actuate these push-buttons

  evenings 20, 21 during the lifting of the piston 12.

  The lower part 10 of the case is fixed to the upper part 9 thereof using for example a crimp 22. The capsule 11 of the thermostat 7 is itself

  fixed for example by a crimp 23 to the lower part

  lower 10 of the shoemaker. In the vicinity of thermostat 7, the

  lower tie 10 is provided on the one hand with a threaded seat 24 which allows it to be fixed by screwing into the wall 25

  from the radiator water boot and secondly from a six-

  sides 26 intended to receive a tightening key. The guide 15 passes through the lower part 10 of the shoemaker at the level of the

  threaded seat 24, with interposition of a seal

tee 27.

  The body of the conductor 16, of approximate shape-

  parallelepiped, is fixed relative to the housing 9,

  10. A slider 28 fits this body so as to be guided

  dice in translation by the latter, parallel to the axis of

  translation (vertical in Figure 2) of piston 12. The neck

  beam 28 is biased towards piston 12 by a spring

  29 bearing on the body of the switch 16.

  The slide 28 carries laterally two ramps or partially oblique elastic blades 30 and 31 (see also Figure 3) whose positions and / or shapes are such that the blade 30 first attacks the push button 20, then the blade 31 attacks the push button 21, when the

  piston 12 lifts. According to the embodiment shown

  felt, the pushbuttons 20 and 21 protrude at the same height on a lateral face of the body of the contactor 16 and the blades 30 and 31 have different and adjustable inclinations preferably using each of a screw such as 32 , passing through the slide 28. The two blades 30 and 31 can be made in one piece with a bar 33, the latter being fixed to the slide 28 using screws

  or rivets 34. Opposite the adjusting screws 32, the part above

  bottom 9 of the shoemaker 9, 10 includes an access opening

  which is normally closed by a 3- cap.

  A thermal switch 8 is thus obtained, the function of which

  operation is as follows. Before installing it on a water box, the operating threshold of the

  contacts by tilting the blades 30, 31 more or less with

  of screws 32. Then the thermoswitch is put in place by screwing it using the threaded seat 24, the capsule II containing the waxy material 13 thus being licked by the water

  cooling circulating in the water box.

  When the temperature of this water is below a first threshold, the piston 12 is sufficiently pressed into the guide 15 so that the two blades 30, 31 carried by the slide 28 do not touch the push buttons 20, 21. The contacts 4 and 6 of figure 1 are then opened

  both and fan motor 1 is not energized.

The fan is therefore stopped.

  When the temperature rises above a first threshold but remains below a second threshold, the piston 12 lifts the slider 28 sufficiently so that

  the blade 30 depresses the push button 20, which corresponds to

  lays when the contact 4 of FIG. 1 is closed, the contact 6 remaining open. Motor 1 is therefore supplied by

  through resistor 5 and drives ventilation

medium speed.

  When the temperature rises above the second threshold, the piston 12 raises the slide 28 enough for the blade 31 to push the push button 21, which corresponds to the closing of the contact 6 of FIG. 1. The motor 1 is therefore directly supplied by the source

current 2.

  The same operations occur in reverse when the water temperature drops above the

  second threshold, then the first threshold.

  Instead of individually adjusting the two temperature thresholds using the screws 32, the ramps 30 and 31 could first of all be set up so that they determine a predetermined difference between the thresholds of

  temperature corresponding to the triggering of the buttons-

  push-buttons 20 and 21, then adjust only the first temperature threshold by blasting (or controlled local depression) of capsule II of thermostat 7. The screws 32 and the plug

are then deleted.

Claims (8)

  1. Staged thermal switch, intended in particular to switch on at medium speed and at full speed the   electric motor of the ventilation system   motor vehicle engine cooling depending on whether the temperature of the latter engine reaches and exceeds a first threshold or a second threshold higher than the first, characterized in that it comprises a housing (9, 10) at one end of which is fixed a wax thermostat   (7) so that such as the capsule (11) of this thermo-   stat (7) is located outside the housing (9, 10) and the piston (12) of the thermostat (7) penetrates more or less inside the housing (9, 10) depending on the temperature of the material polisher (13) contained in the capsule (11); in this   that the housing (9, 10) contains a contactor (16) comprising   both an input (17) and at least two outputs (18, 19) and control members (20, 21) associated respectively with said outputs (18, 19); in that the entry (17) and the   outputs (18, 19) of the contactor (16) are connected respectively   connection to accessible connection terminals outside the housing (9, 10); and in that a mechanism (28, 30, 31) is interposed between the aforesaid piston (12) and the control members (20, 21) so as to successively actuate these members (20, 21) during the movement of penetration of   piston (12) inside the housing (9, 10).   2. A thermal switch according to claim 1, ca2rac-   terized in that the contactor body (16) is fixed by   with respect to the housing (9, 10) and in that the above-mentioned mechanism   me (28, 30, 31) is movable in translation inside the housing (9, 10), parallel to the piston (12) of the thermostat (7).   3. Thermocontact according to one of claims 1   and 2, characterized in that the mechanism is essential-   ment constituted by a slide (28) guided in translation   parallel to the piston (12) of the thermostat (7) and stressed   tee by a spring (29) towards this piston (12).   4. Thermocontact according to all the claims   tions 3 and 4, characterized in that the body of the contactor (16) is approximately parallelepipedic and in that the slide (28) fits this body so as to be guided by this one.   5. Thermocontact according to one of claims 3   and 4, characterized in that the slide (28) carries two ramps (30, 31) cooperating respectively with the control members (20, 21) of the contactor (16), the assembly being such that one of the ramps ( 30) attacks one of the control members (20) before the other ramp (31) attacks the other control member (31), during the exit movement piston (12).   6. Thermocontact according to claim 5, charac-   terized in that the contactor control members (16) consist of push buttons (20, 21) carried by a face of the body which is parallel to the piston (12) and in that the ramps (30, 31) carried by the slide   (28) are oblique to the axis of the piston (12).   7. Thermocontact according to claim 6, charac-   terized in that each ramp is formed by a blade   elastic (30, 31) whose inclination, at the level of the button-   corresponding push-button (20, 21), is adjustable, in particular using a screw (32).   8. Thermocontact according to claim 7, charac-   terized in that the elastic blades (30, 31) are   titled in one piece with a common bar (33)   used to fix them to the slide (28).