FR2814201A1 - LIQUID CONTROL VALVE COMPRISING A CENTRAL LEAKAGE DRAIN - Google Patents

Abstract

A liquid control valve comprising a metering valve and a metering valve control valve. A pressure check valve (2) performs several functions. On the one hand, it defines a standby pressure for the metering valve and evacuates leaks from the metering valve. It also evacuates leaks from the control valve. The pressure of the leakage liquid from the control valve is significantly lower than that from the metering valve. The pressure check valve is made so that the two leakage liquids are brought together with different pressure levels to be discharged.

Description

STATE OF THE ART The present invention relates to a valve

  The invention relates in particular to an injector of a so-called common rail injection system, controlled by pressure. Such injectors generally include a 3/2 way slide valve or distributor as a metering valve for the quantity of fuel to be injected, as well as a solenoid valve for controlling the metering valve. During the operation of the injection, we meet

  leaks from both the metering valve and the solenoid valve.

  However, these leaks must be eliminated. As in operation, the sou-

  metering valve and solenoid valve work at different pressure levels

  For example, a separate leak line must be provided for each valve. The metering valve is at a higher pressure level than i5 the solenoid valve. The two separate leak lines cannot simply be joined together, because due to the higher pressure level of the

  metering valve, compared to that of the solenoid valve,

  would mage or deteriorate the solenoid valve or create a reaction

beach. Advantages of the invention

  The object of the present invention is to remedy these drawbacks.

  come and concerns for this purpose a valve of the type defined above, ie

  characterized in that it includes a metering valve for metering a

  quantity of fuel to be injected, a control valve for

  applying the metering valve and a pressure relief valve with a valve seat, a valve member and a spring element, the pressure relief valve being designed to generate a standby pressure for the metering valve, for discharging a quantity of end of control and / or a first quantity of leaking liquid from the metering valve, and for discharging a second quantity of leaking from the control valve, at a pressure level lower than the first quantity

  end of order / leakage liquid.

  The liquid control valve according to the invention pre-

  feels the advantage over the state of the art of having only one branch

  Common leakage check for the metering valve and the control valve. There is provided a pressure relief valve having a valve seat, a valve member and a spring member. The pressure check valve is used on the one hand to create a standby pressure for the metering valve and on the other hand to discharge the quantity of end-of-order liquid and / or a first quantity of leaking liquid from the metering valve. The pressure relief valve is used for

  in addition to evacuating a second quantity of leakage from the control valve

  mande. The second amount of leaking liquid is at a lower pressure level than the first amount of leaking liquid or end of order quantity. The pressure check valve according to the invention thus makes it possible to receive the second quantity of leakage liquid which is at a different pressure level and to lead this quantity of leakage to a common leakage connection. This reduces in particular the cost of manufacturing an additional leakage pipe and the assembly and

  valve treatment according to the invention are considerably simplified

fied.

  To achieve a specific choking effect, the sou-

  pressure retaining pope preferably comprises a separate throttling device. This makes it possible to determine the throttling effect which also depends on the degree of opening of the valve element of the

  pressure check valve, and reaching pressure states

  completed. It is particularly advantageous that the throttle device is installed in the valve seat in front of the valve element. The pressure relief valve preferably has

  a retaining element for retaining and guiding the valve element at the level

  valve seat calf. This ensures that the element

valve and guide this item.

  Preferably, the retaining element comprises a central outlet hole. This outlet hole evacuates the quantities of

  leak from the metering valve and the control valve.

  The retaining element preferably has a cylindrical zone in which the central outlet hole is made and

  which is used to guide the spring element.

  The spring element is preferably a cylindrical helical spring which bears against the cylindrical region of the retaining element

which guides him very well.

  Preferably, an arrival of the second quan-

  There is a leakage liquid from the control valve at the retainer. This ensures that the cylindrical area of the retaining element which receives the spring element is always surrounded by liquid, protecting the spring element against pressure pulsations acting on the pressure retaining valve, since the liquid around

  the spring element absorbs pulsations. This prevents pre-wear

  of the spring element. To have a simple connection between the arrival of the second quantity of liquid leaking from the control valve and the central outlet hole, the retaining element comprises

  preferably one or more through holes.

  To prevent the valve element from moving too far from its seat, and the pressure retaining valve no longer closes or the valve element is separated from the retaining element, provision is made

  preferably a stroke limitation on the retainer to limit

ter the course of it.

  According to a preferred embodiment of the present invention, the pressure retaining valve includes a guide washer to provide additional guidance of the retaining element and define a

  preload of the spring element.

  Preferably, the pressure check valve

  sion is a pre-assembled set. This allows the pressure check valve to be checked for proper functioning before mounting.

  in the valve to control the liquid.

  In addition, this modular construction allows a replacement

  quick cementing of the pressure relief valve, for example in the event of a malfunction. It also makes it simple,

  according to the customer's wishes, to provide special connection possibilities

  specific on the pressure check valve. As a connection to the leakage pipe, it is possible, for example, to provide a thread or a quick connection means. For a simple connection of the leakage pipe of the control valve, the external periphery of the pressure-retaining valve made as a constructive assembly has an annular groove. This annular groove is connected on its side by a hole

  transverse to the actual pressure relief valve.

  It should also be noted that the control valve is preferably produced as a solenoid valve and the metering valve preferably in the form of a 3/2 valve or distributor valve

tract.

  According to the invention, there is thus a pressure retaining valve in particular for an injector of a common rail system which is able to combine two leakage currents of different pressure levels, which reduces to a single leakage connection. on the injector. The pressure relief valve can be fully integrated into

  the injector or even be made as a whole.

  Drawings The present invention will be described below with the aid of different embodiments shown in the accompanying drawings, in which: - Figure 1 is a schematic sectional view of a pressure relief valve produced in the form of 'an assembly corresponding to a first embodiment of the invention, - Figure 2 is a partial detail view of the pressure relief valve of Figure 1 in the assembled state, - Figure 3 is a view in partial section of a pressure check valve corresponds to a second embodiment of the invention in the assembled state, - Figure 4 is a partial sectional view of a pressure check valve corresponding to a third example of realization of

the invention, in the assembled state.

  Description of the exemplary embodiments

  Figures 1 and 2 show a valve for controlling

  liquids with a check valve 2 according to the present invention.

  According to FIG. 1, the pressure check valve 2 is produced in the form of a compact assembly comprising a connection nozzle 3 with a connection device 4. According to FIG. 2, the connection device 4 is a connection device fast for

  the quick connection of a common pipe for the evacuation of the

  what to do in the direction of arrow A. The connection nozzle 3

  comprises a central bore 5 receiving the different parts of the support

pressure retaining valve 2.

  According to FIG. 1, the pressure check valve 2 comprises

  carries a valve seat 6, a ball forming a closure member 7, a retaining element 8, a cylindrical helical spring 19 and a guide washer 18. The guide washer 18 is housed in the bore 5 of the nozzle 3 for example by a pressed seat and serves as a spring seat for

the helical spring 19.

  According to FIG. 1, the retaining element 8 comprises a segment

  retaining ment 27 for the valve ball 7, a first guide segment 9, a second guide segment 10 and a cylindrical zone 11. The cylindrical zone 11 is located between the first guide segment 9 and the second segment of guide 10. Two through holes 14 are

  made in the cylindrical zone 11. In addition, there are two holes for connection

  sound 13 near the retaining zone 27 of the retaining element 8. The second guide segment 10 is located with the inner periphery with the guide washer 18 in contact with the first guide segment 9

  in the receiving hole 5 (see figure 1). Therefore, the rete-

  nude 8 is guided in two points, which allows precise positioning and

reliable ball 7 placed free.

  To prevent the ball 7 forming a shutter member from lifting too far from its seat and moving away from the retaining element 8, the latter has a stop 23 to limit its travel. As the stop 23 comes into contact with the guide washer 18, this limits the travel of the retaining element 8. It should be noted that by the choice of the axial thickness of the guide washer 18, it is possible to adjust to both the race of

  the retaining element 8 and the preload of the spring element 19.

  As appears in particular in FIG. 2, the leakage of the metering valve (not shown) is thus provided for metering the quantity of fuel to be injected and / or the quantity of end of control of

  the metering valve via line 21 to the pressure check valve

  sion 2. Thus, the pressure check valve 2 provides pressure

  constant at the metering valve. The leak or the quantity

  corresponding to the end of control of the metering valve will be as shown in Figure 2, supplied in the direction of arrow B, by the line

  21 to the pressure check valve 2. The pressure check valve

  sion 2 opens against the force of the spring 19 making it possible to evacuate the leak.

  As appears in particular in FIG. 1, upstream of the ball 7, a throttling installation 17 is provided for throttling the desired pressure in the pipe 21. The throttling installation 17 is formed in the valve seat 6 The leakage from the metering valve is transmitted by the two connecting holes 13 to the central evacuation hole 12 and from there the leakage is evacuated in the direction of arrow A. A leakage from the control valve (not shown) to control the metering valve is transmitted as shown in Figure 2, by a leakage pipe 20 in the direction of arrow C to the pressure relief valve 2. In the connection nozzle 3, a groove is provided peripheral annular 16 provided with connection holes 15 so that the leakage pipe 20 communicates with the receiving hole 5. Through through holes 14 made in the cylindrical zone 11 of the retaining element 8, the control valve leaks and also passes through the central discharge hole 12 in the direction of the arrow A. As during the operation of the valve 1, there are often pressure pulsations acting on the valve pressure retaining valve 2, there is a risk of damaging the coil spring 19. To avoid this, the quantity of control end of the metering valve is evacuated by the central bore 12. There is also a leak to prevent it from establish a back pressure in the spring chamber of the first

  guide segment 9, between the fixing element 8 and the receiving bore

  tion 5, so that the leakage liquid also arrives at the helical spring 19. This ensures shock absorption on the

  pressure relief valve 2 by the liquid surrounding the helical spring

  coidal 19. In addition, the helical spring 19 is guided relatively-

  ment narrow in the cylindrical area 1 1 of the retainer 8, so

  that the helical spring 19 can neither shift nor deform. We re-

  thus further reduces the risk of damage to the coil spring 19.

  The pressure check valve 2 made as in-

  seems constructive, according to the first exemplary embodiment of FIG. 2,

  is screwed into a thread 22 of the valve 1. To prevent leakage of liquid

  outwardly, a seal 24 is provided between the connection nozzle 3 of the check valve 2 and the valve 1. It is possible to

  consider here an implementation in the form of a rapid connection.

  Thus, a common pipe or connection 4 is provided for leaks from the metering valve and the control valve to compensate for the different pressure levels of the leaks.

  through the pressure check valve 2. In the outlet line

  mune, there will be a pressure corresponding essentially to the pressure

  in line 20 of the control valve or a lower pressure

dre.

  FIG. 3 shows a valve 1 for controlling lines

  that with a pressure relief valve 2 according to the invention cor-

  corresponding to a second exemplary embodiment. The same parts

  bear the same references as in the first exemplary embodiment.

  As the second example of embodiment corresponds essentially to the

  first, only the differences will be described below.

  Unlike the first embodiment, the second

  example includes a connection device 4 for the connection nozzle

  dement 3 produced in the form of a thread. This means that the pipe that is joined to the nozzle 3 will be fixed using the thread 4 of the nozzle 3. For the rest, the second embodiment corresponds to the first, so

  that it is not necessary to detail it below.

  FIG. 4 shows a valve 1 for controlling the lines

  quides comprising a pressure retaining valve 2 corresponding to a third embodiment of the invention. The same elements

  that in the first exemplary embodiment bear the same references.

  As the third exemplary embodiment corresponds essentially to the exemplary embodiments described above, only the differences will be detailed below in 350s.

  Unlike the first two exemplary embodiments, i5 the pressure relief valve of the third exemplary embodiment is not an assembly but it is formed from the assembly of different parts directly in the valve 1. According to FIG. 4, the leakage pipe 21 of the metering valve does not arrive in the central position in the pressure check valve 2. The throttle member 17 is made as 351 as in the first two exemplary embodiments, upstream of the ball 7 in the valve seat 6. The details of the pressure relief valve 2 correspond to the details of the exemplary embodiment described above.

  The leakage liquid from the control valve is transmitted by pipes (not shown \ 351sent \ 351es) and the through hole 14, to the central exhaust outlet 12 of the pressure check valve 2. The central outlet bore 12 is connected \ 351 by the outlet pipes 26 \ 340 the nozzle 25 made \ 351alis \ 351 on the valve 1 for the connection of the pipes (see FIG. 4). Thus, for leaks from the metering valve and the control valve, a common leakage line 26 is provided. For the rest, the valve 1 with the pressure relief valve 2 according to the third exemplary embodiment corresponds to the exemplary embodiments described above, so that the description will not be described. 351taill \ 351st.

  Thus, the present invention relates to a valve for controlling liquids, having a metering valve and a control valve for controlling the metering valve. There is also a pressure relief valve 2 performing several functions.

  2814201 8 On the one hand, the pressure check valve 2 \ 351 establishes a standby pressure of the metering valve and \ 351does leaks from the metering valve. The pressure relief valve 2 \ 351 also leaks \ 351 from the control valve. The pressure of the leakage liquid from the control valve 5 is much lower than the pressure of the leakage liquid from the metering valve. The pressure check valve 2 according to the invention is designed to combine leaking liquids with different pressure levels and to evacuate the assembly by a common leakage pipe.

  The above description of the exemplary embodiments according to the invention corresponds only to an explanation and does not limit the invention in any way. Within the scope of the invention, it is possible to envisage various modifications and variants without departing from the scope of the invention.

Claims (4)

CLAIMS 1 \ 260) Liquid control valve characterized \ 351ris \ 351e in that it comprises a metering valve for metering a quantity \ 351 of fuel \ 340 injected, a control valve for controlling the metering valve and a pressure check valve (2) with a valve seat (6), a valve \ 351l \ 351ment (7) and a spring \ 351l \ 351ment \ 340 (19), the valve pressure relief valve (2) \ 351 as soon as \ 351alis \ 351e to generate a waiting pressure for the metering valve, to \ 351 release a quantity of end of 10 orders and / or a first quantity \ 351 of liquid leaking from the metering valve, and for discharging a second quantity \ 351 of leakage from the control valve, \ 340 a pressure level lower than the first quantity \ 351 of liquid end / leakage.   2 \ 260) Liquid control valve according to claim 1, characterized \ 351ris \ 351e in that the pressure relief valve (2) further comprises a throttling device (17).   20 3 \ 260) Liquid control valve according to claim 1, characterized \ 351ris \ 351e in that the pressure relief valve (2) has a \ 351l \ 351ment retaining element (8) for retaining and guiding the \ 351l \ 351ment of valve (7) on its seat \ 350ge (6).   25 4 \ 260) Liquid control valve according to claim 3, characterized in that the retaining element (8) comprises a central drainage hole (12).   5 \ 260) Liquid control valve according to claim 3, 30 characters \ 351ris \ 351e in that the retaining \ 351l \ 351ment (8) has a cylindrical zone (11) to guide a \ 351l \ 351ment spring (19) constituted \ 351 by a cylindrical h \ 351lico \ 357dal spring.   35 6 \ 260) Liquid control valve according to claim 3, characterized \ 351ris \ 351e in that an arrival (351e (20) of the second quantity \ 351 of liquid leaking from the mouth control valve in the restraint area (351l \ 351ment (8)). 2814201 10   7 \ 260) Liquid control valve according to claim 4, characterized in that the retaining element (8) is provided with a through hole (14) for adjusting it. ser the communication between the second quantity \ 351 of leaking liquid and the central drain \ 351 drain (12).   8 \ 260) Liquid control valve according to claim 3, characterized in that the retaining element (8) has a purpose \ 351e (23) to limit the stroke of 10 l \ 351l \ 351ment retainer (8).   9 \ 260) Liquid control valve according to claim 8, characterized \ 351ris \ 351e in that the pressure retaining valve (2) has a guide washer 15 (18) for guiding the retaining \ 351l \ 351ment (8) and to determine the preload of the h \ 351lico \ 357dal spring (19).   10 \ 260) A valve according to claim 1, characterized \ 351ris \ 351e in that the pressure relief valve (2) is a preassembled assembly 351. NotAvailable