Abstract:
The pressure regulating valve ( 2 ) proposed here can be designed with the aid of the outflow throttle restriction ( 28 ) downstream of the valve seat ( 22 ) in such a way that the pressure regulating valve ( 2 ), as the fluid flow becomes greater, sets or adjusts a smaller pressure difference at the pressure regulating valve ( 2 ), as a result of which the line losses that can never be avoided can be compensated for. The pressure regulating valve is suitable in particular for a fuel supply system of a motor vehicle having an internal combustion engine.

Description:
FIELD OF THE INVENTION 
     The invention is based on a pressure regulating valve and a method for producing a pressure regulating valve. 
     BACKGROUND OF THE INVENTION 
     German Published, Unexamined Patent Application DE 197 54 243 A1 shows a pressure regulating valve of a fuel supply system. A supply line leads to the pressure regulating valve, and a line extending onward carries the fuel away from the pressure regulating valve. Depending on the change in magnitude of the fluid flow flowing through the pressure regulating valve, the flow resistances in the supply line and in the line leading onward vary. These fluctuations in flow resistances cause troublesome fluctuations in the pressure level that is to be regulated by the pressure regulating valve in the fuel supply system. Because especially the line leading onward is often relatively long and should have the smallest possible cross section, the flow resistances in the line leading onward fluctuate considerably, as a function of the magnitude of the fluid flow. As a result, the pressure level regulated by the pressure regulating valve undesirably fluctuates very greatly as well. 
     Additionally, in the pressure regulating valve shown in DE 197 54 243 A1, a damping device is provided, which is intended to prevent excessive oscillation of the closing body of the pressure regulating valve. However, in the known pressure regulating valve, the damping device has the disadvantage that for lack of an adequate flow through the damper chamber, gas can accumulate, which can very severely impair the damping action of the damping device. Another disadvantage is that the closing body has a complicated shape, making its production relatively complicated and expensive. Another disadvantage is that the tappet connecting the damper piston to the ball is immediately adjacent the closing body in the region of the valve seat, and as a result dimensional imprecisions arise that can lead to leakage, which cannot be allowed. A further disadvantage is that if adequate damping action is to be achieved, the damper piston must be guided with very tight play. This means the pressure regulating valve is severely vulnerable to dirt. 
     OBJECT AND SUMMARY OF THE INVENTION 
     The pressure regulating valve according to the invention and the method for producing a pressure regulating valve have the advantage over the prior art that a substantially simpler to produce and markedly better-functioning pressure regulating valve is available. In particular, excellent values regarding tightness, pressure regulation quality, and the desired small structural size are attainable. 
     In particular, the advantage is obtained that whenever the closing body has lifted at least partly away from the valve seat, a pressure backs up upstream of the outflow throttle restriction, and this backed-up pressure additionally acts on the closing body in the opening direction. This has the advantage that when the fluid flow flowing through the pressure regulating valve increases, the closing body, at a large fluid flow, lifts increasingly far from the valve seat, and that as a result, as the fluid flow becomes larger, the flow resistance through the pressure regulating valve decreases. Since often in the line upstream of the pressure regulating valve and especially in the line downstream of the pressure regulating valve the resistance rises as the fluid flow increases, the possibility exists, because of this decreasing characteristic curve of the pressure regulating valve, of compensating for these flow resistances in the lines, so that the pressure to be regulated by the pressure regulating valve can be kept constant, largely independently of the magnitude of the fluid flow. 
     If the outflow throttle restriction is disposed on one side relative to the fluid opening, this has the advantage that the closing body is pressed unilaterally against its guide. As a result, conditions that are defined precisely in terms of hydraulics and mechanics are advantageously obtained in the region between the closing body and the valve seat and also between the closing body and the closing body guide. This has the advantage that the closing body rests eccentrically on one side on the closing body guide, always in the same way, and that as a result, an easily controlled, unchanging, predictable, constant regulating behavior of the pressure regulating valve is assured. Another advantage is that between the closing body guide and the closing body, always-constant, easily controlled frictional forces are assured. These frictional forces offer the advantage of an additional easily controlled damping. The overall result obtained is a constant, easily controlled regulating behavior of the pressure regulating valve. 
     Because the outflow throttle is provided radially outside the closing body guide, a relatively large annular gap is obtained around the valve seat between the closing body and the dividing wall, so that the fluid flowing through between the closing body and the valve seat can flow through with uniform distribution over the circumference and can then flow tangentially around the closing body in the direction of the outflow throttle restriction and can then flow out in the direction of the fluid continuation. 
     If the closing body guide is formed by a sheath and the outflow throttle restriction is provided in the sheath, in which case the outflow throttle restriction can be formed in a very simple way by a simple hole in the sheath, the overall result is an especially low production cost. 
     If the closing body is formed by at least one ball, this has the advantage of ease of manufacture, and very good quality is also attainable at low effort and expense. 
     If the closing body is formed by at least two balls solidly joined together, this has the advantage that especially good throttling with a relatively large gap is attainable at low production cost and effort for the delivery throttle opening. The relatively large gap that is allowed offers the advantage of less vulnerability to dirt, and production variations, which can never be avoided entirely, are not as critical. Another advantage is that if balls are used, canting of the closing body in the closing body guide need not be feared. 
     With the damping devise, through which the fluid flow flows constantly when the closing body is lifted from the valve seat, having the damper chamber, and with the delivery throttle opening and the discharge throttle opening, the advantage is attained that no gas bubbles can accumulate in the damper chamber. Because the damper chamber has a fluid flow flowing through it, even the smallest air bubbles or outgassing of fuel are entrained constantly by the fluid flow. This has the advantage that the damping action functions highly reliably. 
     Since a fluid flow constantly flows through the damper chamber when the fluid opening is at least partly open, and since where there is a throttle restriction the flow resistance typically rises quadratically as a function of the fluid flow, very good damping action is obtained. The damping action in this damping device is substantially greater than in a damping device that has a damper chamber without a flow through it. As a result, the flow cross-sectional areas of the delivery throttle opening and the discharge throttle opening can be substantially larger than in a damping device with a damper chamber that does not have a fluid flow flowing through it. Production is therefore substantially simpler, and in particular the dimensional and shape tolerances to be adhered to are not as close, and the damping device is substantially less vulnerable to dirt. 
     If the gap between the closing body and the closing body guide is used to act as a delivery throttle opening, this has the advantage that the delivery throttle opening can be produced without additional expense. 
     If the hole that forms the discharge throttle opening is disposed such that it points upward out of the damper chamber, this has the advantage that entrainment of gas bubbles from the damper chamber can be improved still further and is assured highly reliably. 
     The invention will be better understood and further objects and advantages thereof will become more apparent from the ensuing detailed description of preferred embodiments taken in conjunction with the drawing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a longitudinal section through a selected, preferred, especially advantageous exemplary embodiment; 
     FIG. 2 is a graph showing the dependency between the hydraulic supplementary closing force F and the fluid flow Q flowing the damper chamber; and 
     FIGS. 3-5 each show one longitudinal section through three further differently embodied, preferably selected and especially advantageous exemplary embodiments. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The pressure regulating valve embodied according to the invention serves to regulate a pressure in a chamber that contains a fluid, for instance for regulating a pressure difference between a chamber at a higher pressure and another chamber at a lower pressure. The pressure regulating valve is suitable especially in fuel supply systems, and the fluid is preferably a liquid, especially fuel and preferably gasoline, but it can also be diesel fuel. The pressure regulating valve can be used preferably in internal combustion engines in which a pressure of the fuel in the fuel supply system is to be regulated. The pressure regulating valve is mounted at some suitable mounting point in the fuel supply system. The mounting point is for instance an opening in a fuel distributor tube belonging to the fuel supply system, or an opening in a housing of a fuel pump of the fuel supply system, or a cap of a fuel tank, or the pressure regulating valve is installed in the housing of a fuel filter. 
     By means of the fuel supply system, fuel pumped by a fuel pump flows via a pressure line to the mounting point that receives the pressure regulating valve and thus reaches the fluid inlet of the pressure regulating valve. From the fluid continuation of the pressure regulating valve, fuel is returned to the fuel tank, for instance, or flows to a consumer that receives the fuel, such as an injection valve that meters the fuel to an internal combustion engine. The fuel is preferably gasoline, and the engine together with the fuel supply system is preferably installed in a motor vehicle. 
     FIG. 1 shows a longitudinal section through an especially advantageous pressure regulating valve  2  selected as a preferred example for the explanation herein. This exemplary pressure regulating valve  2  is a substantially rotationally symmetrical structure. 
     The pressure regulating valve  2  is built into a housing  4 , for instance, which is shown only in part. The housing  4  is the housing of a fuel filter, for instance. In the housing  4 , there is a fluid inlet  6  and a fluid continuation  8 . From a fuel pump, not shown, the pumped fluid passes via the fluid inlet  6  to the pressure regulating valve  2 , and from the pressure regulating valve  2 , via the fluid continuation  8 , the fluid returns to a fuel tank, not shown. The pressure of the fluid in the fluid inlet  6  should be greater, by a specific pressure difference, than the pressure of the fluid in the fluid continuation  8 . A dividing wall  10  divides the fluid continuation  8  from the fluid inlet  6 . The dividing wall  10  is joined in fluid-tight fashion to the housing  4  via a crimped edge  12  extending all the way around. 
     A thimble-like sheath  14  is solidly joined to the dividing wall  10 , for instance via a materially bonded connection  16 . By way of example, the materially bonded connection  16  is a spot weld, in particular a resistance-welded spot, or an adhesive bond, by way of which the sheath  14  is affixed to the dividing wall  10 . A fluid opening  18  is provided in the dividing wall  10 . Depending on a position of a closing body  20 , the fluid inlet  6  communicates with the fluid continuation  8  through the fluid opening  18 . The closing body  20  has one side  20 c toward the fluid inlet  6  and one side  20   d  remote from the fluid inlet  6 . 
     In the preferred exemplary embodiment, a circular valve seat  22  is provided on the side of the dividing wall  10  toward the fluid continuation  8 , on the circumference of the fluid opening  18 . A spring device  24  urges the closing body  20  against the valve seat  22 . The spring device  24  engages the side  20   d  of the closing body  20  and presses the side  20   c  against the valve seat  22 . In the preferred exemplary embodiment selected, the sheath  14  has an end portion  14   a  remote from the fluid opening  18 , a cylindrical portion  14   b,  and a radially widened portion  14   c  on the end of the cylindrical portion  14   b  remote from the end portion  14   a.  The sheath  14  has a shoulder  14   d  between the cylindrical portion  14   b  and the widened portion  14   c.    
     The inner jacket face of the cylindrical portion  14   b  of the sheath  14  forms a closing body guide  26 . The closing body guide  26  serves to guide the closing body  20 , and at the narrowest point between the closing body  20  and closing body guide  26 , a constriction  37  is formed. As a function of the pressure difference between the pressure in the fluid inlet  6  and the pressure in the fluid continuation  8 , the closing body  20  lifts more or less far away from the valve seat  22 , counter to the force of the spring device  24 . 
     An outflow throttle restriction  28  is provided in the widened portion  14   c  of the sheath  14 . An intermediate pressure chamber  30  extending all the way around is formed, bounded by part of the closing body  20 , by the valve seat  22 , by part of the dividing wall  10 , by the widened portion  14   c  of the sheath  14 , and by the shoulder  14   d  of the sheath  14 . 
     The outflow throttle restriction  28  is formed by a throttle opening  28   a  provided in the widened portion  14   c  or on the widened portion  14   c  of the sheath  14 . The throttle opening  28   a  is easily produced in the form of a slot made on the sheath  14 , or a bore made in the sheath  14 . 
     In the preferred, selected, especially advantageous exemplary embodiment, the closing body  20  comprises a first ball  20   a,  toward the valve seat  22 , and a second ball  20   b.  The first ball  20   a  and the second ball  20   b  are solidly joined together, for instance via a spot weld  20   s.  The side  20   c  is located on the first ball  20   a,  and the side  20   d  is located on the second ball  20   b.    
     The ball  20   a  of the closing body  20  has a face that is surrounded by the valve seat  22  and is acted upon hydraulically by the inflow pressure prevailing in the fluid inlet  6 ; this face will be hereinafter called the inlet pressure face  20   e.    
     Between the valve seat  22  and the narrowest point between the ball  20   a  and the closing body guide  26 , or in other words at the constriction  37 , there is an encompassing annular face  20   z,  which is acted upon by the intermediate pressure prevailing in the intermediate pressure chamber  30 . This face will hereinafter be called the intermediate pressure face  20   z.  Of the intermediate pressure face  20   z,  it is the area component of the cross-sectional area transverse to the direction of motion of the closing body  20  that is hydraulically operative. 
     As the drawing shows, the spring device  24  comprises a helically wound spring  24   a,  which is braced on one end on the end portion  14   a  of the sheath  14  and on the other on the side  20   d  of the second ball  20   b  of the closing body  20 . 
     A damper chamber  32  is formed, bounded in the axial direction by the side  20   d  of the second ball  20   b  of the closing body  20  on one side and by the end portion  14   a  of the sheath  14  on the other, and in the radial direction by the inner jacket face of the cylindrical portion  14   b  of the sheath  14 . 
     At the narrowest point between the first ball  20   a  of the closing body  20  and the closing body guide  26 , a first guidance gap  36   a  is created, and at the narrowest point between the second ball  20   b  and the closing body guide  26 , a second guidance gap  36   b  is created. An intermediate chamber  34  is formed between the two guidance gaps  36   a  and  36   b.  The first guidance gap  36   a  and the second guidance gap  36   b  are connected in series in hydraulic terms and form a delivery throttle opening  36 , which forms constriction  37 . In the end portion  14   a,  a hole  38   a  is provided at the highest point of the sheath  14 , in terms of the installed position. The hole  38   a  forms a discharge throttle opening  38 . 
     If the pressure in the fluid inlet  6  is enough higher than in the fluid continuation  8  that the closing body  20  has lifted from the valve seat  22 , then the fluid flowing out of the fluid inlet  6  through the outflow throttle restriction  28  into the fluid continuation  8  is throttled at the outflow throttle restriction  28 . This creates a pressure in the intermediate pressure chamber  30  that is higher than the pressure in the fluid continuation  8 . The pressure prevailing in the intermediate pressure chamber  30  will hereinafter be called the intermediate pressure. Because of the pressure difference between the intermediate pressure in the intermediate pressure chamber  30  and the pressure in the fluid continuation  8 , some of the fluid flows through the delivery throttle opening  36  into the damper chamber  32  and from there through the discharge throttle opening  38  into the fluid continuation  8 . 
     The outflow throttle restriction  28 , or in concrete terms the throttle opening  28   a,  is disposed such that the fluid flow flowing through the delivery throttle opening  36 , the damper chamber  32 , and the discharge throttle opening  38  rejoins the fluid flow, flowing through the outflow throttle restriction  28 , downstream of the outflow throttle restriction  28 . 
     The cross-sectional areas of the delivery throttle opening  36  and of the discharge throttle opening  38  are adapted to the cross-sectional area of the throttle opening  28   a  of the outflow throttle restriction  28  in such a way that the fluid flow flowing through the damper chamber  32  is substantially less than the fluid flow flowing through the outflow throttle restriction  28 . 
     The intermediate pressure prevailing in the intermediate pressure chamber  30  also acts in the opening direction on the intermediate pressure face  20   z  of the closing body  20 . With increasing overpressure in the fluid inlet  6 , for instance if the fluid flow that is supposed to flow out of the fluid inlet  6  into the fluid continuation  8  is greater, then the first ball  20   a  lifts increasingly far from the valve seat  22 . As a result, the intermediate pressure in the intermediate pressure chamber  30  also rises accordingly, which causes the closing body  20  to lift still farther from the valve seat  22 . With the outflow throttle restriction  28  and by means of the intermediate pressure thus engendered, it can be attained that with increasing magnitude of the fluid flow, the closing body  20  lifts disproportionately far from the valve seat  22 . The effect of the disproportionate lifting of the closing body  20  is that with an increasing fluid flow, the pressure difference between the pressure in the fluid inlet  6  and the pressure in the fluid continuation  8  lessens. Accordingly, a regulated pressure is obtained that decreases as a function of the increasing fluid flow. By a choice of the free cross-sectional area of the outflow throttle restriction  28 , the increase in proportion between the pressure difference at the pressure regulating valve  2  and the fluid flow can be adapted to the flow resistances, which increase as the fluid flow increases, in the lines upstream and downstream of the pressure regulating valve  2  in such a way that overall, regardless of the magnitude of the fluid flow, a constant pressure prevails in the chamber whose pressure is to be regulated with the pressure regulating valve  2 . With the aid of the intermediate pressure in the intermediate pressure chamber  30 , it is easily possible to compensate for line resistances that are dependent on the magnitude of the fluid flow. 
     Because of the shoulder  14   d  of the sheath  14 , the intermediate pressure chamber  30  extending annularly all the way around is given a relatively large cross-sectional area, as FIG. 1 shows. This offers the advantage that the fluid can flow out of the fluid opening  18  over the entire circumference of the fluid opening  18  between the valve seat  22  and the ball  20   a  into the intermediate pressure chamber  30 , and because of the large cross-sectional area of the intermediate pressure chamber  30 , the fluid can flow largely unthrottled through the intermediate pressure chamber  30  to the outflow throttle restriction  28 . Because of the large cross-sectional area of the intermediate pressure chamber  30 , the intermediate pressure can act on the intermediate pressure face  20   z  everywhere and uniformly. 
     It is proposed that only a single throttle opening  28   a  be provided for the outflow throttle restriction  28  in the sheath  14 , preferably in the widened portion  14   c  of the sheath  14 . A plurality of throttle openings distributed uniformly over the circumference in the widened portion  14   c  is possible. The unilateral disposition of the throttle opening  28   a  assures that as soon as the ball  20   a  has lifted from the valve seat  22 , the closing body  20  is pressed radially in the direction of the throttle opening  28   a  against the closing body guide  26 . As a result, a precisely defined location of the closing body  20  is attained that remains constant. Thus hydraulically precisely defined conditions are obtained with regard to the fluid flow flowing through the damper chamber  32 . Also by the contact of the closing body  20  with the closing body guide  26 , mechanical friction is achieved, which makes an additional contribution to the hydraulic damping device  40  to prevent oscillation of the closing body  20 . 
     The delivery throttle opening  36 , the damper chamber  32 , and the discharge throttle opening  38  in cooperation form the damping device  40 . 
     As soon as the closing body  20  has lifted somewhat from the valve seat  22 , some of the fluid flow flows out of the intermediate pressure chamber  30  through the delivery throttle opening  36 , or more precisely through the first guidance gap  36   a  into the intermediate chamber  34  and then through the second guidance gap  36   b,  wherein the guidance gaps  36   a  and  36   b  form constriction  37 , into the damper chamber  32 , and then from the damper chamber  32  through the discharge throttle opening  38  into the fluid continuation  8 . The delivery throttle opening  36  and the discharge throttle opening  38  form two throttles, connected hydraulically in series, as a result of which a pressure arises in the damper chamber  32  that in terms of the pressure value is between the pressure in the fluid inlet  6  and the pressure in the fluid continuation  8 , or between the pressure in the intermediate pressure chamber  30  and the pressure in the fluid continuation  8 . 
     The pressure prevailing in the damper chamber  32  acts hydraulically as a supplementary closing force F, in addition to the force of the spring device  24 , on the closing body  20  in the closing direction. The graph shown in FIG. 2 illustrates the dependency between the hydraulically acting supplementary closing force F and the fluid flow Q flowing through the discharge throttle opening  38 . The dependency is parabolic. 
     Assuming a mean fluid flow Q 1 , as an example, the mean hydraulic supplementary closing force F 1  is obtained. Any possible oscillation of the closing body  20  leads to oscillation of the fluid flow Q flowing through the discharge throttle opening  38 . For the purposes of this explanation, let it be assumed that the fluid flow Q fluctuates by the amount dQ, for instance. Because of the dependency illustrated in FIG. 2, the hydraulic supplementary closing force F then fluctuates by the amount dF. This fluctuation of the supplementary closing force F by the amount dF is oriented counter to the motion of the closing body  20 . Because of the fluid flow Q 1  that flows constantly through the discharge throttle opening  38 , and because of the principle of throttling, even a slight fluctuation dQ in the fluid flow Q produces a relatively major fluctuation dF in the closing force F. It can be seen from FIG. 2 that the fluctuation of the supplementary closing force F by the amount dF depends on the magnitude of the mean fluid flow Q. Without the mean fluid flow Q, the fluctuation dF in the supplementary closing force F would be less; that is, the hydraulic damping would be substantially less effective. The advantages thus obtained that even with a relatively large gap between the closing body  20  and the closing body guide  26 , or in other words despite a relatively large first guidance gap  36   a  and a relatively large second guidance gap  36   b , adequately good damping of the oscillation of the closing body  20  can nevertheless be achieved. Because of the relatively large guidance gaps  36   a  and  36   b  that are possible, the expense for producing the guidance gaps  36   a  and  36   b  is relatively slight, and little sensitivity to dirt is obtained, so that even certain dirt particles in the fluid do not lead to seizing of the closing body  20 . 
     The branching off of the fluid flow, flowing through the damper chamber  32 , from the intermediate pressure chamber  30  has the advantage that, when the fluid opening  18  is at least partly open, and on account of the intermediate pressure backed up in the intermediate pressure chamber  30 , a constant flow through the damper chamber  32  is assured, and nevertheless the advantage is obtained that whenever the closing body  20  is seated on the valve seat  22 , a fluid flow flowing through the damper chamber  32  is reliably prevented. 
     FIG. 3 shows a longitudinal section through a further preferably selected, especially advantageous exemplary embodiment. 
     In all the drawing figures, elements that are the same or function the same are provided with the same reference numerals. Unless otherwise noted or shown in the drawing, what is mentioned and shown in conjunction with one of the drawing figures applies to the other exemplary embodiments as well. Unless otherwise stated in the explanation, the details of the various exemplary embodiments can be combined with one another. 
     In the modified exemplary embodiment shown in FIG. 3, the closing body  20  is embodied by the single ball  20   a.  Here the spring  24   a  of the spring device  24  acts on the single ball  20   a  that forms the closing body  20 . 
     In this exemplary embodiment as well, the outflow throttle restriction  28  is formed by the throttle opening  28   a  provided in the sheath  14 . A closing body guide  26  is again provided on the sheath  14 . For the sake of simplicity in producing the pressure regulating valve  2 , a graduation of the sheath  14  to enlarge the intermediate pressure chamber  30  has been dispensed with in this exemplary embodiment. 
     In this exemplary embodiment, the sheath  14  is firmly retained by a clamping piece  46 . The clamping piece  46  is by way of example a deep-drawn component made from a piece of sheet metal, and it is tubular. The clamping piece  46  is pressed into the cup-shaped dividing wall  10  so far that the clamping piece  46  presses the sheath  14  on its face end against the dividing wall  10 . As a result, the sheath  14  is firmly retained and fixed on the dividing wall  10 . 
     Openings  46   a  are provided in the tubular clamping piece and enable a flow of the fluid flow in the direction of the fluid continuation  8 . The spring  24   a  of the spring device  24  is braced on one end on the clamping piece  46  and on the other on the side  20   d  of the closing body  20 . By plastic deformation of the clamping piece  46  in the axial direction that occurs after assembly, the opening pressure of the pressure regulating valve  2  can be adjusted. 
     FIG. 4 shows a further preferably selected, especially advantageous exemplary embodiment. 
     In this exemplary embodiment, the sheath  14  is embodied as a turned part. This makes it especially easy to provide the widened portion  14   c  between the cylindrical portion  14   b  and the valve seat  22 . As a result, it is easy to make the cross-sectional area of the intermediate pressure chamber  30  relatively large in the circumferential direction, so that the intermediate pressure in the intermediate pressure chamber  30  can act uniformly over the entire circumference on the intermediate pressure face  20   z.    
     The closing body guide  26  is located on the inner jacket face of the cylindrical portion  14   b,  and the throttle opening  28   a,  in the region of the shoulder  14   d,  leads out of the intermediate pressure chamber  30  through the sheath  14  in the direction of the fluid continuation  8 . 
     FIG. 5 shows a longitudinal section through a further preferably selected, especially advantageous exemplary embodiment. 
     In this exemplary embodiment, the sheath  14  is connected firmly to the dividing wall  10  via the materially bonded connection  16 . Resistance welding can for instance be employed as one possible connection method. 
     In the exemplary embodiment shown in FIG. 5, the tube  14  is an especially easily produced turned part or an especially easily produced deep-drawn part, or a cold-headed part which is especially easy to produce by plastic reshaping. However, here as well the sheath  14  can be provided with a graduation, for the sake of enlarging the intermediate pressure chamber  30 . 
     The clamping piece  46 , which serves to retain the spring  24   a  of the spring device  24 , is an easily produced sheet-metal part, which is press-fitted into the cup-shaped inner region of the dividing wall  10 . By pressing the clamping piece  46  more or less far into the dividing wall  10 , the initial tension of the spring  24   a  and thus the opening pressure of the pressure regulating valve  2  can be adjusted or set. 
     In the preferred selected exemplary embodiments, there is play  48  all the way around in the radial direction between the sheath  14  and the inner jacket face of the cup-shaped dividing wall  10 . This play  48  is provided so that before the sheath  14  is fixed relative to the dividing wall  10 , the sheath  14  can be displaced radially relative to the dividing wall  10 . The spacing or play  48  extending all the way around makes it possible to align the sheath  14  relative to the dividing wall  10 . 
     In the exemplary embodiments selected for the drawings, the valve seat  22  is located directly on the dividing wall  10 . However, it should be noted that the pressure regulating valve  2  can also be modified, specifically in such a way that the valve seat  22  is located directly on the dividing wall  10 . This is the case for instance whenever a ring is firmly press-fitted into the fluid opening  18 , specifically in such a way that the valve seat  22  is located on an inner surrounding edge of the tightly press-fitted ring. 
     The following method is proposed for assembling the pressure regulating valve  2 , in the exemplary embodiment shown in FIG.  1 : 
     First, the spring  24   a  and then the closing body  20  are placed in the sheath  14 . Next, the sheath  14  is pressed, together with the spring  24   a  and the closing body  20 , against the face end of the dividing wall  10  with slight force. When the sheath  14  is pressed on its face end against the dividing wall  10 , then the spring  24   a  presses the ball  20   a  into the fluid opening  18  having the valve seat  22  extending all the way around. Pressing the ball  20   a  into the circular fluid opening  18  against the valve seat  22  creates a centering force exerted on the ball  20   a  by the valve seat  22 . By way of the tight play between the ball  20   a  and the closing body guide  26  at the sheath  14 , the centering force also acts on the sheath  14 , with the tendency to center the sheath  14 , and thus the closing body guide  26 , relative to the valve seat  22 . The adequately dimensioned play  48  makes it possible to align the sheath  14 . 
     During the assembly and during the process of aligning the closing body guide  26  relative to the valve seat  22 , the sheath  14  is retained against the dividing wall  10 . As a result, a force hereinafter called the aligning force is created in the radial direction, or in other words transversely to the longitudinal axis of the closing body guide  26 . It should be noted that during the aligning of the closing body guide  26 , the aligning force is less than the centering force. In particular, care must be taken, during the aligning, to press the sheath  14  against the dividing wall  10  only just strongly enough that the aligning force is still less than the centering force. 
     If the aligning force that retains the sheath  14  in the transverse direction is less than the centering force that centers the sheath  14 , then in the manner described, the sheath  14  is centered relative to the valve seat  22  and thus relative to the fluid opening  18  in a simple way but with excellent quality. 
     Once the sheath  14  has been centered relative to the valve seat  22 , the sheath  14  is fixed relative to the dividing wall  10 . The fixation of the sheath  14  relative to the dividing wall  10  can be done by means of the materially bonded connection  16 , for instance. For the materially bonded connection  16 , an attractive option is to retain the sheath  14  on its face end against the dividing wall  10  and to join the sheath  14  solidly to the dividing wall  10  via a resistance welding process. 
     For the assembly of the various exemplary embodiments shown in FIGS. 3 and 4, the following method is proposed: 
     First, the sheath  14  is placed on its face end against the dividing wall  10 . Then the clamping piece  46  is press-fitted into the cup-shaped dividing wall  10 . During this press-fitting of the clamping piece  46 , the spring  24   a  of the spring device  24  is placed between the contact point at the clamping piece  46  and the side  20   d  of the closing body  20 . During the assembly, the sheath  14  can be roughly aligned with the aid of a tool that reaches through the openings  46   a.  As the clamping piece  46  is being press-fitted into the dividing wall  10 , the spring  24   a  presses the ball  20   a  into the fluid opening  18  and against the valve seat  22 . This creates a centering force that acts from the valve seat  22  on the ball  20   a,  counter to the closing force of the spring  24 . This centering force is transmitted from the ball  20   a  to the sheath  14 . The result is excellent centering of the closing body guide  26 , provided on the sheath  14 , relative to the valve seat  22 . In the exemplary embodiments of FIGS. 3 and 4 as well, care must be taken that during the centering operation, the aligning force be kept less than the centering force. 
     Once the sheath  14  has been aligned relative to the valve seat  22 , the clamping piece  46  is press-fitted even substantially more strongly into the cup-shaped dividing wall  10 , causing the clamping piece  46  to clamp the sheath  14  against the dividing wall  10  with such great force that slippage of the sheath  14  relative to the dividing wall  10  can no longer ensue. In a simple way, this assures a fixation of the sheath  14  and thus an excellent-quality alignment of the sheath  14  relative to the valve seat  22 . After that, if the customer wishes it, the sheath  14  can be welded to the dividing wall  10 . 
     In the exemplary embodiment shown in FIG. 5, the following method is proposed for the assembly of the pressure regulating valve  2 : 
     First, the sheath  14  is placed on its face end against the bottom of the cup-shaped dividing wall  10 . Next, the ball  20   a  representing the closing body  20  is placed in the sheath  14 . Then with the aid of the spring  24   a,  the ball  20   a  is pressed against the valve seat  22 . This creates a centering force acting in the radial direction on the closing body  20 . This centering force also acts on the sheath  14  via the ball  20   a  and thus assures centering of the sheath  14  relative to the valve seat  22  and thus relative to the fluid opening  18 . Next, the clamping piece  46  is press-fitted so far into the cup-shaped dividing wall  10  that the spring  24   a  is pre-stressed so much that the desired opening pressure of the pressure regulating valve  2  is assured. During the centering of the sheath  14  and while the sheath  14  is being fixed on the dividing wall  10 , the sheath  14  can be retained with the aid of a tool that reaches the openings  46   a.    
     The foregoing relates to preferred exemplary embodiments of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.