FR2626619A1 - OVERPRESSURE VALVE DEVICE FOR THE COOLING CIRCUIT OF A LIQUID COOLED INTERNAL COMBUSTION MACHINE - Google Patents

Abstract

Pressure relief valve device for the cooling circuit of a liquid-cooled internal combustion machine, with a closing cover 12 which can be screwed onto the filler neck 11 of a coolant tank 10 and carrying a relief valve. built-in overpressure 14. The valve closure element 16 guided in a guide sleeve 25 is held on the closure cover by means of a pre-stressed return spring 15. The guide sleeve 25 can be applied in a sealed manner, with an outer annular collar 26, against the front face 30 of the filler neck 11. The closure cover 12 is attached, in positive engagement in the axial direction, to the sleeve. guide 25, while leaving an axial play L which becomes effective when opening the closing cover 12, at least one prestressed spring 31, the rigidity of which is greater than that of the return spring 15 being disposed between the two elements . At the start of unscrewing the closing cover 12, the spring keeps the guide sleeve 25 in the sealing position, the return spring 15 then being released and the valve closing element 16 being able to be lifted under the action of system pressure to relieve overpressure in the cooling system.

Description

Pressure relief valve device for the cooling circuit

  The invention relates to a pressure relief valve device for the cooling circuit of a liquid-cooled internal combustion machine, with a closure cover which can be screwed onto the manifold. filling a coolant tank and carrying an integrated pressure relief valve, the valve closing element of which is guided in a guide sleeve and pushed, under the action of a return spring bearing on the cover closure, against a seal placed on an end shoulder of the guide sleeve, said guide sleeve having an annular collar projecting radially outwards and being able to be placed in a sealed manner on the front face of the tubing filling,

  by means of a seal, said collar an-

  ring then being urged by the closure cover.

  There is known a pressure relief device of this kind with a two-stage pressure relief valve (DE-OS 3 422 705) as well as a device of this kind with a valve

  one-stage overpressure (DE-OS 3 717 715) in which the

  filling bulb is mounted in the retracted position and therefore submerged so as to save space. When loosening the closing cover of a hot cooling system and therefore under overpressure, it is possible, under the effect of the overpressure in the air mattress placed above the coolant level, that liquid is ejected through the filler neck. A

  such loss of coolant is not desired

  table since it implies the need to refuel to compensate for the amount lost. In addition, there are

risk of burns.

  The object of the invention is to create a pressure relief valve device of the aforementioned kind which allows, during the

  unscrewing the closing cover, a reduction in the

  pressure in the air mattress above the coolant level without said coolant

  can then escape from the filler neck.

  According to the invention, for a pressure relief valve device of the aforementioned type, this object is achieved by the fact

  that the closing cover is attached, with positive engagement

  tif in the axial direction, to the guide sleeve, while leaving

  sant an axial clearance which becomes effective during the opening of the closure cover, and that, during unscrewing, said closure cover can be moved axially from the

  guide sleeve, with simultaneous discharge of the spring.

  return and opening of the valve closing element,

  said guide sleeve remaining in its sealing position.

  Another advantageous feature is that between the guide sleeve and the closure cover is arranged at least one prestressed spring between the two elements, the

  stiffness is greater than that of the return spring.

  This results in an overpressure valve device which is extremely simple and economical and which allows a simple and reliable reduction of the overpressure in

  the tank when unscrewing the closure cover.

  When the closing cover is unscrewed in the presence

  of an overpressure, a reduction of this overpressure is ob-

  held without ejection of coolant. Thus, the guide sleeve firstly remains in a position which,

  afterwards as before, ensures watertightness, while only the

  closing ring is axially spaced from the guide sleeve, which results in a discharge of the return spring acting on the valve closing element in such a way that said valve closing element can open and that the overpressure can be eliminated without ejection of coolant. This avoids using simple means

  ejection of coolant with all the drawbacks

  resulting from it. The overpressure valve device

  sion is extremely simple. In view of the fact that all

  elements are integrated in the over-valve device

  pressure and therefore in the pressure relief valve which is main-

  held in the closing cover, it is also pos-

  sible. to replace a posteriori of the closure covers with pressure relief valve existing by the variant according to the invention.

  According to another particular characteristic, the dis-

  positive pressure relief valve includes at least one spring

  which consists of a spring washer. He is then

  tagous that said spring rests on the end face of the

  annular collar opposite the valve closure member.

  In another feature, said spring is dis-

  installed & rests on the end of the guide sleeve

  located opposite the end which carries the shoulder, in par-

  especially the annular shoulder, with the seal,

  and directed to the closure cover.

  It is advantageous if the pressure relief valve is

  held on the closing cover by means of an assembly

snap-on wiring.

  According to a characteristic of the invention, it is provided that the guide sleeve comprises, for example in the

  annular collar region, protruding lugs.

  outwardly and the closure cover is provided with at least one projection or a plurality of projections which extend radially inwardly and in the region

  radial of the guide bushing stops

  which projections come into abutment when opening the

  closing cover, after playing the game, on the ta-

  stop quets arranged on the guide sleeve in the

dragging in the axial direction.

  It is advantageous that the stops of the guide sleeve are located at an axial distance and above the annular surface applied against the seal and that they then protrude radially from the circumference of

said annular surface.

  According to another characteristic of the invention, the

  closure cover present, on the inner side direct

  towards the annular collar of the guide sleeve, an annular axial bearing surface through which the cover

  closure can push against the upper side of the collar.

  the guide sleeve, which is directed axially

towards said closure cover.

  Another particular feature of the invention consists in that the projection and respectively the projections of the cover of

  are arranged at an axial distance from the surface of the

then axial interior.

  According to the invention, it is advantageous that the closure cover has, at an axial distance from the internal axial bearing surface, a collar which protrudes radially towards

  the interior and is shaped projecting cooperating with the ta-

  guide bushing quets.

  According to a particular characteristic, the invention

  provides that the collar carries, from the city opposite the surface of ap-

  then axial interior, an annular surface through which the

  closing cover can lie flat on the front side

filling tubing size.

  Another feature of the valve device

  overpressure according to the invention consists in that the collar an-

  of the guide sleeve has annular clearance

  the soil dug from its upper surface and in which

  is centered at least one spring, in particular a washer-

  spring. 25. According to an advantageous feature of the invention,

  it is intended that the seal is made on the shoulder

  Lement, in particular on the annular shoulder, of the guide sleeve in the form of a sealing ring

  molded, with roughly cylindrical inner housing in-

  which can start and end with its opening

  nale, the terminal reduction of an overflow pipe in the coolant tank arranged, by

  example, coaxially with the filler neck.

  All the features mentioned in the.

  description above and below, as well as the details

  tears emerging only from the drawings constitute

  additional elements of the invention.

  The following description, next to the drawings

  appendices by way of nonlimiting examples, will allow good

  understand how the invention can be put into practice.

  FIG. 1 schematically represents a sectional view of a coolant tank for liquid-cooled internal combustion machines, with screwed closure cover and with pressure relief valve, & to the right of the center line in the closed state and to the left of the center line in an open position; Figure 2 shows, schematically and on a larger scale, a perspective view and partially in

  section of a guide sleeve of the pressure relief valve.

  Fig. 1 schematically represents a reservoir of

  coolant 10 which is intended as a reservoir

  see compensation for a coolant circuit

  ment of an internal combustion machine cooled by liquid.

  Other details of the coolant circuit are not shown, nor is a coolant radiator. The coolant tank 10 can also be

  replaced by a collecting tank of the liquid radiator.

  The coolant tank 10 is provided with a filling pipe 1i which is arranged here in a retracted manner and therefore submerged so as to save space. The arrangement is similar to that shown in DE-OS 3 517 715. The coolant tank-10 is

  produced, for example, in the form of a molded part made of

  plastic, the filling tube 11 being conformed thereto

  even in one piece. Having regard to publication DE-OS 3 517 715 at

  which is referred to here, the other details of the re-

  coolant supply 10 do not require

a more detailed explanation.

  The filling pipe 11 can be closed by means of a closing cover 12 which can, for example, be screwed and respectively unscrewed by means of a thread 13. On the closing cover 12 is held, by means

  of a snap-in assembly explained below, a

  pressure relief valve 14 which is of the one-stage type and produced,

  for example, according to the detailed description given

  in DE-OS 3,517,715 or also in the two-stage variant

  described in DE-OS 3 422 705. The details of the relief valve

  pressure 14 which are irrelevant in the context of this

  invention therefore do not require a more detailed description-

  lée. The valve closing element 16 made in the shape of a piston and loaded by a return spring 15 bearing on the closing cover 12 can be actuated by pressure

  of the system prevailing inside 17 of the reservoir 10.

  Inside the tank 10 is disposed an overflow pipe 18 which has a pipe section 19 oriented obliquely upwards, approximately

  to the highest point of the interior space of the reservoir

  see 10, followed by a pipe section 20 which goes up -

  near to the center of the filler neck 11. The

  overflow line 18 opens freely, with an opening

  Terminal structure 21 located at the end of the pipe section 19, in the interior space 17 of the tank 10, at the highest point thereof. In this region, above the level of the liquid indicated by broken lines, an air mattress is contained in the interior space 17. The overflow pipe 18 opens freely, with its other terminal opening 22 located at the end of the other pipe section 20, in the filling pipe 11. In the region of this terminal opening 22, the closing element 16 of the pressure relief valve 14 is subjected to the action of the pressure of the system through the conduct of

overflow 18.

  The valve closing element 16 is guided in a guide sleeve 25 which is produced, for example, in accordance with that according to publication DE-OS 3 422 705

  for a two-story variant or the one according to the publica-

  DE-OS 3,517,715 for the variant & one floor. The socket

  guide 25 has at the upper end a collar an-

  ring 26 protruding radially outwards and, A. ex-

  opposite lower hopper, an annular terminal shoulder 27 projecting radially inward and carrying a seal

  sealing 28. The return spring 15 disposed between the

  valve closing ment 16 and closing cover

2 6266 19

  12 is here configured as a cylindrical spring which engages centrally, at least for the most part, in the interior space of the valve closure element 16 in the form

  of pot. By means of this return spring 15, the element

  valve closing ment 16 is applied against the seal

  seal 28 on the annular shoulder 27. In the posi-

  closing position (fig. 1, to the right of the center line>, the guide sleeve 25 is applied with its annular collar

  26 in a leaktight manner, by means of a sealing joint

  sheaity 29, against the upper front face "S of the tube

  11. ha filling lure upper side of the annular collar

  26 is then urged by the closing cover 12.

  The closure cover 12 is axially attached, with positive engagement, to the guide sleeve 25 leaving

  remain an axial clearance "L" which becomes effective when

  closing cover 12. When unscrewing the

  closing cover 12, this can be moved axially-

  guide sleeve 25 which remains in its posi-

  sealing, namely in fig. I upwards, with simultaneous discharge of the return spring 15 and opening of

  the valve closing member 16 thus made possible.

  At least one spring 31 is arranged between the guide bush 25 and the closing cover 12 which is produced here under

  the shape of a spring washer. Spring 31. is pre-

  trapped between the two pieces. Its rigidity is chosen more

  larger than that of the return spring 15. The end of the spring

  fate 31 rests on the face of the annular collar 26 which is op-

  posed i that which carries the seal 29. The collar

  annular 26 has an annular clearance 33 hollowed A by-

  shot from its upper face 32 and in which the res is centered

  sort 31. The end of said spring then rests on the bottom

34 of the annular clearance 33.

  The pressure relief valve 14 is kept on the

  closure cover 12 by means of a snap-on assembly

  dearly. To this end, the guide sleeve 25 comprises, for example in the region of the annular collar 26, stop lugs 35 projecting radially outwards. Since, according to DE-OS 3 422 705, different radial channels

8 -

  36 are hollow in the upper face of the annular collar

  26, the cleats 35 form different segments of an-

  water separated from each other by the radial channels.

  There are associated with the catches 35 of the guide bush 25 projections 37 arranged on the closing cover and protruding radially inwards and in the radial zone of the catches 35. It is then possible to provide different projections 37 arranged at a distance from each other. others in the circumferential direction. In the embodiment shown, the closure cover 12 is provided

  a continuous collar 37 projecting radially inward.

  and interrupted in the circumferential direction by slits

  dials-arranged apart from each other. When the closing cover 12 is opened, the collar 37, after having passed the gauge referenced by L in FIG. 1, to the right of the center line, abuts on the stop lugs 35 arranged on the guide sleeve 25 by driving them in

the axial direction.

  As is apparent in particular from FIG. 2, the cleats

  stop 35 of the guide sleeve 25 are arranged at

  axially and above the annular surface 38 bearing

  the seal 29, the stoppers 35 protruding

  dialing the circumference of said annular surface 38.

  The closure cover 12 has, on the underside

  directed towards the annular collar 26 of the guide sleeve 25, an axial annular bearing surface 39. In the closed state (fig. 1, to the right of the center line), the cover of

  closure 12 can push axially with this ap-surface

  then 39 against the upper face 32 of the annular collar 26 of the guide sleeve 25 which faces it, which has the effect that the annular surface 38 of the annular collar 26 is pressed against the seal? 9 which is applied from sealingly against the front face 30 of the filling pipe 1I. The collar 37 of the closure cover 12 is disposed at an axial distance from the bearing surface 39 so that, in this closed position, the collar 37 is located at the greatest possible axial distance from the stoppers.

  which corresponds to the set L. The collar 37 wears; on the oppo- side

  the interior bearing surface 39 and directed towards the front face 30 of the filling pipe 11, an annular surface 40. In the closed state <FIG. 1, to the right of the

  center line}, the closure cover 12 can be applied

  with this annular surface 40 against the front face 30

  ia filler neck 11 ensuring sealing.

  The seal 28 disposed on the shoulder an-

  ring 27 of the guide sleeve 25 is produced analogously to the publications DE-OS 3 422 705, 3 517 715 under the

  form of a molded sealing ring 41 which has a lo-

  roughly cylindrical inner housing 42. For example, the conical terminal reduction 23 of section 20 of the pipe

  overflow 18 arranged coaxially with respect to the tube

  filling lure 1I can engage in the internal housing

  laughter 42 and lead to it with its terminal opening 22. The terminal reduction 23 is then tightly enclosed

  in the molded sealing ring 41.

  For a cold internal combustion machine and

  both for a cold coolant, the level of the liquid is on the discontinuous line 43 which corresponds to the lower edge of the filler neck II. With

  the heating of the cooling system, 10th level of the

  quide cooling inside the tank 10 gradually rises to that of line 44 indicated by broken lines, which also causes an increase

  corresponding pressure in the cooling system

  is lying. Above line 44 is located inside the line

  servoir 10, an air mattress which, due to the expansion of the coolant following heating, is

  subjected to a corresponding pressure which acts on the 616-

  closing 16 of the pressure relief valve 14 by the

  intermediate of the overflow pipe 18 with the pipe sections 19, 20 sealed from the liquid. As soon as the operating pressure of 0.6 bar is reached, for example, the closing element. of valve-16 is moved relative to the guide sleeve 25, against the force of the return spring, and opened so that air from the air mattress can escape to the outside through the pipe sections 19, and by the pressure relief valve 14, in accordance with the layout indicated in broken lines in FIG. 1. However,

  coolant cannot escape to the outside

  laughing because the overflow pipe 18 does not communicate, in the region of the terminal opening 21, with the coolant in the reservoir 10 and because it is sealed in the region of the other terminal opening 22, by the molded sealing ring 41 which is applied in leaktight manner against the underside of the guide sleeve 25 and tightly encloses the terminal reduction 23 placed

in the interior housing 42.

  When the cooling system is under pressure

  the opening of the closing cover 12 by unscrewing

  also does not eject coolant

  15th. At the beginning of this opening movement, the spring 31 considerably stiffer compared to the return spring

  first push the guide sleeve 25 with its collar

  let annular 26 against the seal 29 and the latter

  against the annular surface 30 such that a seal

  happiness is ensured in this area. The molded sealing ring 41 ensures, as described, the sealing of the terminal reduction 23 with the terminal opening 22 of the

  overflow line 18. Unscrewing the iron cover

  step 12 simultaneously causes a progressive discharge of the

  return spring 15 weaker compared to spring 31, this

  which results in a reduction in the force applied to the.

  valve closing ment so that said element

  valve 16 opens and allows the cancellation

  overpressure without ejection of coolant

  sement. Given the action of the spring 31, the sleeve of

  guide 25 remains in this sealing position for as long

  time that the clearance L between the collar 37 and the lugs

  is not yet crossed when unscrewing the cover of -

  closing 12. When this clearance is crossed, during the

  subsequent closure cover 12, the collar 37 abuts, from below, against the locking tabs 35 of the guide sleeve 25 so that the guide sleeve is driven in the axial direction and pulled upwards At 1i

  measure that the unscrewing of the closure cover 12 can

  follows. The annular collar 26 is then lifted from the seal

  size 29 and the front face 30 of the filler neck

  wise He. In addition, the molded sealing ring 41 emerges from

  the terminal reduction 23 with the terminal opening 22.

f S626i

REVDICATIONS.

  1. - Pressure relief valve device for the

  coolant circuit of a combustion machine

  internal liquid-cooled, with an iron cover

  strap (12) which can be screwed onto the filler neck

  (Il1) of a coolant tank (10) and'por-

  both an integrated pressure relief valve (14), the element

  closing valve (16) is guided in a guide ring

  dage (25) and pushed, under the action of a return spring (15) bearing on the closure cover (12) against a seal (28) disposed on an end shoulder of the sleeve guide (25), said guide sleeve (25) having an annular collar (26) projecting radially towards

* outside and can be installed in a waterproof manner on the -

  front face (30) of the filling pipe (11), by

  by means of a seal (29), said collar an-

  ring then being biased by the closing cover (12) c a r a c t 6 r i s 6 e n a e that the closing cover (12) is attached, positively engaged in the axial direction, to the guide bush (25), while leaving a clearance

  axial (L) which becomes effective when the cover is opened

  closing ring (12) and that, during unscrewing, said neck

  closing ring can be moved axially away from the bushing

  guide (25), with simultaneous discharge of the return spring.

  (15) and opening of the valve closing element (16),

  said guide sleeve remaining in its 6'-position

  chéitâ. 2, - Pressure relief valve device according to the

  claim. 1, characterized in that between the guide sleeve

  dage (25) and the closure cover (12) is arranged at least one spring (31) prestressed between the two elements, the rigidity of which is greater than that of the return spring (15). 3. - Pressure relief valve device according to claim 2, characterized in that it comprises at least one

  spring (31) which is constituted by a spring washer.

  4. - Pressure relief valve device according to one

  claims 2 or 3, characterized in that it comprises at

  minus a spring (31) which rests on the end face of the

  annular collar (26) opposite the bottom closure member

  pope {16). 5. - Pressure relief valve device according to one

  claims 2 to 4, characterized in that the spring

  (31) is disposed at and bears on the end of the guide sleeve (25) located opposite the end which carries the shoulder, in particular the annular shoulder

  (27), with the seal (28), and directed towards the cou-

closing ring (12).

  6. - Pressure relief valve device according to one

  claims 1 to 5, characterized in that the pressure relief valve

  overpressure {14) is maintained on the closing cover

  (12) by means of a snap-on assembly.

  7. - Pressure relief valve device according to one

  claims 1 to 6, characterized in that the socket

  guide (25) comprises, for example in the region of the annular collar (261, stop lugs (35) projecting radially outwards and that the closure cover (12) is

  provided with at least one projection (37) or with a plurality of sail-

  lees advancing radially inward and into the

  radial region of the locking tabs (35) of the guide sleeve

  (25) which projections come into abutment when opening

  ture of the closing cover (12), after having passed the clearance <L), on the stop cleats (35). arranged on the socket

  guide (25) by driving them in. the axial direction.

  8. - Pressure relief valve device according to claim 7, characterized in that the stop lugs (35} of the guide sleeve (25) are located at an axial distance and above the annular surface (38) applied against the seal (29) and that they then protrude radially from the circumference of said annular surface

(38).

  9. - Pressure relief valve device according to one

  claims 7 or 8, characterized in that the cover

  closure (12) present, on the inner face directed k626619 towards the annular collar (26) of the guide sleeve (25),

  an annular axial bearing surface (39) through which the

  closing ring (12) can push against the upper side

  lower (32) of the annular collar (26) of the guide sleeve (25), which is directed axially towards said closure cover. 10. Pressure relief device according to

  one of claims 7 to 9, characterized in that the sail-

  lie (37) and respectively the projections of the closure cover

  ture (12) are arranged at an axial distance from the surface of ap-

inner axial well (39).

  11. - Pressure relief device according to

  one of claims 7 & 10, characterized in that the neck

  closing ring (12) present, i axial distance from the

  internal app-axial surface (39), a collar (37) which

  passes radially inward and is projecting

  cooperating with the locking tabs (35) of the guide sleeve

dage (25).

  12. - Pressure relief valve device according to claim 11, characterized in that the collar (37) carries, on the opposite side, the internal axial bearing surface (39),

  an annular surface (40) -by which the closure cover-

  ture (12) can rest i flat on the front face (30) of the

filler neck (l1} .-

  13, - Pressure relief device according to

  one of claims 1 to 12, characterized in that the collar

  the annular let (26) of the guide sleeve (25} has a

  annular clearance (33) hollowed out from its upper face

  (32) and in which at least one spring is centered

  (31), in particular a spring washer.

  14. - Pressure relief device according to

  one of claims 1 to 13, characterized in that the

  seal (28) is formed on the shoulder, in par-

  particular on the annular shoulder (27) of the guide sleeve

  dage (25) in the form of a molded sealing ring (41), * with an interior housing (42) & roughly cylindrical in

  which can start and end with its opening

  nale (22), the terminal reduction (23) of an overflow line

  full (18 to 20) in the coolant tank

  ment (10} arranged, for example, coaxially with the filling pipe-11).