EP0618362A1 - Control device for a fluid pressure booster - Google Patents

Abstract

Regulation and control device for a liquid pressure booster system with a pressure generating unit (1) with a pump (5) driven by a motor (4), the suction connection (6) of which the working fluid to be increased in pressure can be supplied and the pressure connection (7 ) is connected to a check valve (13), an operationally adjustable pressure relief valve (19) and a pressure switch (26) with a large ON-OFF switching differential, via which the motor (4) is connected to the mains and one with the outlet side (13a) of the check valve (13) contains a connected first cylinder-piston arrangement (27), the piston rod of which can be brought to bear against an intermediate member which is movably mounted in the switch frame and is biased by a first spring in the direction of a first limit position and which is coupled to a movable contact carrier via a snap arrangement. <IMAGE>

Description

The invention relates to a regulating and control device for a liquid pressure booster system, in particular a high pressure cleaning system, comprising
a pressure generating unit with a pump driven by a motor, the suction port of which the working fluid to be increased in pressure can be supplied and the pressure port is connected to a check valve, the outlet side of which is connected to the pressure outlet of the system, from which the working fluid is at a high level Pressure can be removed
an operationally adjustable pressure relief valve, the inlet of which is connected to the pressure connection, the outlet of which is connected to the suction connection and the control inlet of which is connected to the outlet side of the check valve
and a pressure switch with a large ON-OFF switching difference, via which the motor is connected to the mains and which contains a first cylinder-piston arrangement connected to the outlet side of the check valve, the piston rod of which can be brought into contact with an intermediate element which is movably mounted in the switch frame which is biased towards a first limit position by a first spring and which is coupled to a movable contact carrier via a snap arrangement,
wherein the intermediate member during a movement, which starts from the first limit position assumed in the depressurized state of the cylinder-piston arrangement and is directed to the second limit position, transfers the contact carrier from its ON position to an OFF position, and wherein the intermediate member is reversed , by the drive of the first spring and against the counteracting force of the cylinder-piston arrangement, the contact carrier is transferred to the ON position at a first lower pressure before reaching the first limit position,
and the intermediate member, starting from a position predetermined by the first cylinder-piston arrangement, from an external force, only by overcoming the sum of the spring forces of the first spring and snap arrangement, can be moved further in the direction of its second limit position.

Such regulating and control devices are known. By using a pressure switch with a large ON-OFF switching differential, which goes, for example, at a pressure of 150 bar in the OFF position and a pressure of 20 bar in the ON position (or by using two separately set pressure switches for the switch-on and the switch-off process), these at least to a limited extent eliminate the problem of short-period switch-on and switch-off processes (go-and-stop operation). The reason for this is that the pressure booster systems generally do not contain any storage components, such as a gas-laden storage container. In this sense, practically only hose connections that may exist in the system, which slightly expand the enclosed volume when the pressure increases due to expansion of the walls. If the pump has the working fluid at a nominal pressure of e.g. 150 bar brought and was then switched off by the pressure switch, so with the commercially available pressure switches, a minimal leakage at the outlet valve was sufficient to bring about a large pressure drop and thus to cause the pump to be switched on again. This harmful effect is mitigated by pressure switches with a large ON-OFF switching difference, since this increases the switching periods.

It is customary in the known control and regulating devices to make the working pressure provided by the system variable by adjusting the response pressure of the relief valve. Without further precautions, however, setting the working pressure of the relief valve to a value below the switch-off pressure of the pressure switch means that the pressure switch can never go into the OFF position. The motor and the pump therefore remain switched on continuously, even if no working fluid is removed from the system. In the latter case, the Pump a relatively small volume of working fluid in a closed circuit, which leads from the pump pressure connection via the relief valve back to the pump suction connection. Therefore, after a short time there is a strong heating of this liquid volume and, among other things, the pump, which in particular has a detrimental effect on the piston seals of the pump and, together with their continuous operation, can lead to their premature failure.

A known attempt to solve this problem is to use a specially designed relief valve which contains a limit switch which is controlled by the valve spindle, which is movable in a pressure-dependent manner against the valve spring. The limit switch switches off the motor for a given, generally small spindle stroke. Since the spindle responds even with small pressure changes and thus also causes the pressure switch to change its switching state, the motor is continuously switched on and off. Again, it is known to counteract this switching on and off by means of a further pressure switch. A plurality of pressure switches is therefore required, to which a contactor is added, since the force available on the spindle of the relief valve is only sufficient to drive an auxiliary limit switch.

The object of the invention is to develop a regulating and control device of the type mentioned in such a way that there is no longer-lasting circulation promotion and thus overheating of the working fluid and it is unnecessary to make the pressure switch operationally adjustable with regard to its switch-off pressure or to also have to adjust the pressure switch if this is used to adjust the pressure at the pressure outlet of the System used relief valve is changed in its pressure setting.

The solution to this problem according to the invention is characterized by a stationary second cylinder having a second cylinder-piston arrangement, the pressure connection of which is connected to the outlet side of the check valve, the piston-piston rod biased by a second spring against an inner stop defining the retracted state. When the pressure connection is subjected to a second lower pressure, the unit lifts off the inner stop and, when the second upper pressure is slightly higher, comes to rest on an outer stop,
a stationary third cylinder having a third cylinder-piston arrangement, the pressure connection of which is connected to the pressure connection of the pressure generating unit, the piston-piston rod unit, which is biased by a third spring against an inner stop defining the retracted state, when the pressure connection is acted upon a third lower pressure lifts off the inner stop and, at a slightly higher third upper pressure, comes to bear against an outer stop, the third upper pressure being greater than the first lower pressure (switch-on pressure) and less than the second upper pressure,
a transmission arrangement which is driven by the second piston-piston rod unit and by the third piston-piston rod unit and has a triggering element which can be brought into engagement on the intermediate element of the pressure switch,
the trigger member being movable from an inactive limit position outside the path of movement of the intermediate member into an active limit position in which it engages with a pressure surface on the intermediate member in the sense of its movement to its second limit position and with a force sufficient to overcome the spring forces acting on the member and
wherein the transmission arrangement transfers the trigger member into its active limit position only when the second piston-piston rod unit is in contact with its outer stop and the third piston-piston rod unit is in contact with its inner stop.

In this way, short periodic switching on and off processes (go and stop behavior) can also be avoided.

It is known to provide a water heater for heating the permeated working fluid in a system of the type mentioned at the outset, which can contain, for example, an oil burner as the heat source. To avoid damage to the system due to overheating, it should be ensured that the water heater only becomes effective when the working fluid to be heated is under a certain pressure and, in addition, a minimum amount of working fluid is also passed through, ie. H. Working fluid escapes at the pressure outlet of the system (e.g. at the spray nozzle of a manual valve).

In a further development according to the invention, this problem is solved in that a limit switch with one of its actuating levers in the movement path the third piston-piston rod unit fixed cam is arranged that the cam brings the limit switch to the ON position when this piston-piston rod unit is at or near its outer limit position, which corresponds to the system at the outer stop and that electrical connections of the water heater are connected in series with the electrical connections of the limit switch and the pressure switch to the mains or a main switch.

Preferably, the electrical connections of the water heater are connected to a time switch, which in turn are connected in series with the electrical connections of the limit switch and pressure switch and that the time switch applies voltage to the electrical connections of the water heater after a time delay after its own excitation.

• Fig. 1 ein Schaltbild der gesamten Anlage;
• Fig. 2 eine schematische und teilweise geschnittene Ansicht der in Fig. 1 veranschaulichten Druckschalter-Aggregats;
• Fig. 2A bis Fig. 2D der Fig. 2 entsprechende Ansichten des Druckschalter-Aggregats in verschiedenen Betriebszuständen;
• Fig. 3 eine schematische und teilweise geschnittene Ansicht des in der Ventil-Baugruppe enthaltenen Entlastungs-Ventils, Rückschlagventils und des als Handventil ausgebildeten Auslaßventils;
• Fig. 4 eine schematische und teilweise geschnittene Ansicht des Druckschalter-Aggregats mit einer abgeänderten Ausbildungsform der darin enthaltenen Getriebe-Anordnung und
• Fig. 4A eine der Fig. 4 entsprechende Ansicht der abgeänderten Ausbildungsform in einem anderen Betriebszustand.

Further features and advantages of the invention emerge from the claims and the following description of exemplary embodiments of the invention with reference to the drawings. The drawings show:

• Fig. 1 is a circuit diagram of the entire system;
• Fig. 2 is a schematic and partially sectioned view of the pressure switch assembly illustrated in Fig. 1;
• 2A to 2D of FIG. 2 corresponding views of the pressure switch unit in different operating states;
• 3 shows a schematic and partially sectioned view of the relief valve, check valve and the outlet valve embodied as a manual valve, contained in the valve assembly;
• Fig. 4 is a schematic and partially sectioned view of the pressure switch unit with a modified embodiment of the gear arrangement contained therein and
• 4A is a view corresponding to FIG. 4 of the modified embodiment in a different operating state.

The following description of the exemplary embodiments is to be preceded by the explanations which also apply to the claims:

A number of specific print specifications are provided for better understanding. However, only the staggering of the pressures is important for the function of the subject matter of the invention, while the numerical size of the individual pressures depends on the specific area of application of the system.

Unless expressly stated otherwise, the indication "stationary" means that the position of a component in the operating state of the device is fixed in relation to the switch frame of the pressure switch.

The various assemblies, referred to as "cylinder-piston arrangements", can be replaced by technically equivalent arrangements which, depending on the pressure of a fluid acting on them, change the spatial position of a link in a preferably linear movement, for example membrane or bellows arrangements.

“Working liquid” or “liquid” is to be understood as the liquid which has passed through the system and is delivered to its pressure outlet, which liquid generally consists of water which can contain additives such as cleaning agents or the like.

As shown in FIG. 1, the entire system comprises the following assemblies, which are explained in more detail below with reference to the other figures:
A pressure generating unit designated in its entirety by 1,
a valve assembly designated in its entirety with 2 and
a pressure switch unit designated in its entirety by 3.

The pressure generating unit 1 (Fig. 1) contains a pump 5 driven by a motor 4 with a suction port 6 and a pressure port 7. The suction port 6 is acted upon by the working fluid. The working fluid is usually supplied with a relatively low pressure (a few bar), for example by connecting to a drinking water supply network. Between the pressure connection 7, at which the working fluid leaves the pressure generating unit and the suction connection 6, a safety valve (pressure relief valve) 8 is switched on, which is set to a trigger pressure p-ü of 165 bar.

Optionally, the pressure generating unit 1 can also contain a water heater 9, which serves to heat the working fluid and which preferably has an oil burner as the heat source 10. The heat source is switched on by applying a voltage to its electrical connections 11a, 11b. However, the water heater 9 is advantageously arranged such that the working fluid flows through it as one of the last components before it leaves the valve assembly 2 and thus the entire system at its pressure outlet 12.

The valve assembly 2 (FIGS. 1 and 3) is connected with its pressure inlet 7a to the pressure connection 7 of the pressure generating unit 1. It contains, one after the other in the direction of flow of the working fluid, a check valve 13 connected to the pressure inlet and an outlet valve 14 connected to its outlet side 13a. The outlet valve 14 serves to block or to release those provided by the system at its pressure outlet 12, working fluid under high pressure. In the majority of applications, the outlet valve is formed by a manual valve which is connected to the outlet side 13a of the check valve 13 via a hose 15 and which contains an actuating lever 16, a valve plug controlled thereby and a spray nozzle 17. The outlet valve can also be designed differently, for example as a solenoid valve
The valve assembly 2 also contains a relief valve 19, which with its inlet 20 to the pressure inlet 7a, with its control inlet 21 to the outlet side 13a of the check valve 13 and with its outlet 22 to the suction port 6 of the pressure generating unit 1 connected. The relief valve contains a piston 23 displaceable in a cylinder bore, which a valve spring 24, which is adjustable in its force, prestresses in the direction of a first limit position and which, depending on its pressurization via the control inlet 21, counteracts the spring action in the direction of a second limit position is displaceable and thereby lifts a valve body 25 from its seat and opens a flow path for the working fluid from the inlet 20 to the outlet 22 and thus to the suction port 6.

The pressure switch unit 3 (Fig. 1 and Fig. 2) contains a pressure switch 26 (Fig. 2), which is designed for a large on-off difference, i.e. at a switch-on pressure p-1a of 20 bar, it transfers its movable contacts 26a to an ON position in which they establish a connection between its electrical connections 26b, 26c and it transfers at a switch-off pressure p-1b (nominal pressure of the system) from 150 bar to an OFF position. The pressure desired by the operator at the pressure outlet 12 of the system is carried out by adjusting the relief valve (changing the tension of the valve spring 24). With such a pressure setting, it is not necessary to adjust the pressure switch 26 accordingly or to make it operationally adjustable.

The pressure switch 26 has a first cylinder-piston arrangement, designated 27 in its entirety, with a longitudinal axis A (which also defines the pressure switch longitudinal axis). This arrangement contains a first cylinder 29 fixed to the switch frame 28, which in the area of its otherwise closed bottom has a first pressure connection 30 for the application of the working liquid, which is connected to the outlet side 13a of the check valve 13. In the area of its free cylinder end facing away from the ground, the cylinder 29 is connected to the free atmosphere. A piston 31 is displaceable in the cylinder and is fixedly connected to a piston rod 32, which is designed as a fork-shaped body 33 at its free end. On one side, the stroke of the piston-piston rod unit 31, 32 is limited by an inner stop which defines a first limit position and which is formed by the contact of the body 33 with the free end of the cylinder 29.

During a movement originating from the inner stop, the body 33, after a predetermined free stroke, strikes a prestressed strong working spring 34 supported on the switch frame 28. An intermediate member 35 is pivotally mounted in the switch frame about a pivot axis D perpendicular to the longitudinal axis A, which is supported by a further spring 36 (hereinafter referred to as the first spring) is biased in the direction of a first limit position and which, via a snap arrangement 37, drives a contact carrier 38 which holds the movable contacts 26a and is movably mounted in the switch frame. The intermediate member 35 is pressed by the first spring 36 onto rollers 39 supported by the body 33. It follows a positive movement of the body 33 starting from the first limit position, but can also be influenced by an external actuating force N (see also the triggering element described later) which is sufficient to overcome the spring 36 and the tension of the snap arrangement 37 be moved to its second limit position, lifting it off the rollers 39. Even before the second limit position is reached, the snap arrangement 37 causes the contact carrier 38 to be brought into its OFF position.

The pressure switch assembly 2 further comprises a second cylinder-piston arrangement, designated 40 in its entirety, with a longitudinal axis B. This contains a stationary second cylinder 42, which in the otherwise closed area of its base 43 has a pressure connection 44 for the application of the working fluid which is connected to the outlet side 13a of the check valve 13. In the area of the free cylinder end 45 facing away from the floor, a relief opening 46 is provided which is connected to the free atmosphere. A second piston 47 is displaceable in the cylinder 42 and is fixedly connected to a piston rod 48. The stroke of the second piston-piston rod unit 47, 48 is limited by an outer stop 49 in the direction of the free cylinder end and an inner stop 50 in the direction of the cylinder bottom 43.

A second spring 51 is fixedly supported at one end and, at the other end, biases the second piston-piston rod unit 47, 48 in the direction of the cylinder base 43, that is to say to the inner stop 50. This spring is designed so that the piston-piston rod unit 47, 48 is present at the inner stop 50 up to a second lower pressure p-2a of approx Moved towards the outer stop 49 and comes to bear against the outer stop at a second upper pressure p-2b of 40 bar. In the event of a further increase in pressure, the piston-piston rod unit remains in its position specified by the outer stop, this stop 49 absorbing the force exerted by the piston 47.

The pressure switch unit 2 further comprises a third cylinder-piston arrangement, designated in its entirety by 52, with a longitudinal axis C. This contains a stationary third cylinder 53, which in the otherwise closed area of its base 54 has a pressure connection 55 for the application of the working fluid , which is connected to the pressure inlet 7a of the valve assembly 2. In the region of the free cylinder end 56 facing away from the floor, a relief opening 57 is provided which is connected to the free atmosphere. A third piston 58 is displaceable in the cylinder 53 and is fixedly connected to a piston rod 59. An external stop 60 in the direction of the free cylinder end and an inner stop 61 in the direction of the cylinder base 54 limit the stroke of the third piston-piston rod unit 58, 59.

A third spring 62 is fixedly supported at one end and biases the second piston-piston rod unit 58, 59 towards the cylinder bottom 54, ie towards the inner stop 61, at its other end. This spring is designed in such a way that the piston-piston rod unit 58, 59 is present at the inner stop 61 up to a third lower pressure p-3a of approx. 28.5 bar at the pressure connection 55, and lifts off this stop when the pressure increases further moves in the direction of the outer stop 60 and at a third upper pressure p-3b of 30 bar comes to bear against the outer stop. In the event of a further increase in pressure, the piston-piston rod unit remains in the position predetermined by the outer stop, this stop absorbing the force exerted by the piston 58.

In the preferred embodiment shown in the drawing, the free end of the second and third cylinders 42/53 is provided with a cover 63/64, in the central bore of which the piston rod 48/59 is guided and the spring 51/62 is designed as a helical compression spring , which, surrounding the piston rod 48/59, is clamped between the inside of the cover and the piston 47/58. Furthermore, the inner stop 50/61 is formed by a central projection on the bottom of the piston which can come to bear on an inner surface of the cylinder bottom 43/54 and it is the outer stop 49/60 by a member projecting from the inner wall of the cylinder 65/66 formed (e.g. a sleeve surrounding the spring and supported on the cover) on which the piston can come to rest.

The longitudinal axes A, B, C of the first, second and third cylinder-piston arrangements 27/40/52 lie in a common longitudinal plane and run parallel to one another. All three cylinder-piston arrangements 27/40/52 are directed in the same direction, i.e. their piston-piston rod units 31.32 / 47.48 / 58.59 move in the same direction when the pressure is increased.

The pressure switch unit also comprises a gear arrangement, designated in its entirety by 67, which is driven by the second piston-piston rod unit 47, 48 and by the third piston-piston rod unit 58, 59. The gear arrangement 67 contains a movable trigger member 68 which has a pressure surface 69 which can be moved from the gear arrangement 67 from a first inactive limit position to a second active limit position (and back).

In the inactive limit position, the pressure surface 69 or the trigger member 68 is outside and in the active limit position within the path of movement of the intermediate member 35 of the pressure switch 26. The arrangement is also such that the pressure surface 69 moves from the inactive to the active limit position can exert on the intermediate member 35 by exerting a compressive force N and can move it towards its second limit position at least to such an extent that the snap arrangement 37 transfers the movable contacts 26a to the OFF position, ie acts on the intermediate member in the same way as the first piston-piston rod unit 31, 32 by means of its rollers 39. As already explained earlier, the intermediate member 35 lifts off the rollers 39 so that it, without the pistons Need to drag the piston rod unit 31, 32 only by overcoming the sum of the forces exerted by the first spring 36 and the snap arrangement 37 on the intermediate member.

The basic function of the gear arrangement 67 is that it determines the position of the trigger member 68 depending on the position which the second and third piston-piston rod units 47, 48 / 59.60 assume. More precisely, the transmission arrangement transfers the triggering member into the aforementioned active limit position only when the second piston-piston rod unit 47, 48 is located on its outer stop 49 (or is immediately adjacent to it) and the third piston Piston rod unit 59,60 bears against its inner stop 61 (or is directly adjacent to it).

This also means that the trigger member 68 is then brought into the active limit position by the gear arrangement 67 and thereby brings the pressure switch 26 into its OFF position when the pressure on the outlet side 13a of the check valve 13 (which corresponds to the pressure at the system outlet valve 14) is equal to or greater than the upper second pressure p-2b of 40 bar, in any case greater than the lower second pressure p-2a of 38 bar and if as a second condition the pressure at the pressure inlet 7a Valve assembly 2 is equal to or less than the lower third pressure p-2a of 28.5 bar, in any case less than the upper third pressure p-2b of 30 bar.

A person skilled in the art is readily able, on the basis of the above-described mode of operation, to implement a gear arrangement 67 suitable for the invention. A particularly simple embodiment of the gear arrangement 67 illustrated in FIG. 2 consists of a lever 70 which is fastened at its first end to the third piston rod 59 with a joint, the joint axis E of which is parallel to the pivot axis D of the intermediate member contained in the pressure switch 26 35 and perpendicular to the common longitudinal plane containing the longitudinal axes A, B, C of the three cylinder-piston arrangements. The lever 70 can therefore perform a pivoting movement in the latter plane (practically the plane of the drawing in FIG. 2).

At the second, free end of the lever 70 is the pressure surface 69, which is designed to reduce friction as a roller 71 with an axis of rotation F parallel to the joint axis E. Between the two ends of the lever 70 there is a contact surface 72 on which the free end of the second Piston rod 48 abuts. The lever 70 therefore also forms the trigger member 68 with its region adjoining the free end.

A limit switch 73, for example a microswitch, is arranged with its actuating lever 74 in the movement path of a cam 75 fastened to the third piston-piston rod unit 58, 59 in such a way that it establishes a conductive connection between its electrical connections 73a, 73b when it is established the piston-piston rod unit has lifted from its inner stop 59 and is approaching its outer stop 60. The limit switch 73 is therefore always brought into the ON position when the pressure in the third cylinder-piston arrangement 52 and thus the pressure at the pressure inlet 7a of the valve assembly 2 reaches the third lower pressure p-3a of FIG. Exceeds 5 bar.

A timer switch (timer relay) 76 is connected in series with the electrical connections 26b, 26c / 73a, 73b of the pressure switch 26 and the limit switch 73 to the mains or to a main switch. This timer is in turn connected to the electrical connections 11a, 11b of the heat source (oil burner) 10 of the water heater 9, in such a way that the heat source is only activated after a predetermined time delay after the timer 76 has received voltage, i. H. after the pressure switch 26 and the limit switch 73 have reached the ON position.

Has the first spring 36 a relative to the design of the pressure switch 26 cooperating with the gear arrangement 67 strong compressive force and / or the second cylinder-piston arrangement 40 is designed so that its compressive force is just sufficient to bring the intermediate member 35 into its second limit position via the transmission arrangement, an unstable equilibrium position of this cylinder-piston arrangement can be detrimental to affect the function. The mentioned lability occurs when the value p-2b of 40 bar is reached when the second pressure drops and the hydraulic force on the piston 47 is in equilibrium with the force of the second spring 51 (force-free application of the second piston-piston rod unit 47.48 on the outer stop 49). If the third piston-piston rod unit moves to its inner stop 61 in this state, a force is exerted via the lever 70, which is supported on its pressure surface 69 on the intermediate member 35, which force the second Kolbeb piston rod unit in the direction of its inner stop 50 shifts.

This problem can be solved with little effort in a modified embodiment, as is illustrated in FIGS. 4 and 4A, namely by means of a locking device, generally designated 77. This could also be implemented in other ways, for example by means of a slidably mounted bolt.

According to the embodiment illustrated in the drawing, a two-armed angle lever 78 is provided as the locking device, which can be pivoted about a fixed joint axis G. This penetrates the angle lever near the junction of its two legs 78a and 78b. The first leg 78a lies against the free end of the second piston-piston rod unit 47, 48. The second leg 78b has at its free end a sliding surface 79 which bears on the contact surface 72 of the lever 70. This contact surface 72 contains a section 72a, which as one of the boundary surfaces of a triangular notch of the lever 70 is formed. The position and orientation of the section 72a and the position of the hinge axis G of the angle lever 78 is selected so that with a second piston-piston rod unit 47, 48 resting on the outer stop and a third piston-piston rod unit 58 resting on the inner stop 61 , 59 the sliding surface 79 on the second leg 78b touches the section 72a and that a straight line which is laid through the point of contact and through the hinge axis G is at least approximately perpendicular to the section.

As a result, the lever 70 is supported via the hinge axis G, so that the lever (regardless of whether the second piston-piston rod unit 47, 48 is in an unstable state) with its contact surface section 72a is articulated around the sliding surface 79 can rotate and its trigger member 68 brings into the active limit position (conditionally OFF position of the limit switch 26) when the third piston-piston rod unit 58, 59 moves to its inner stop 61.

A return spring (not shown in the drawing) or a non-positive or positive connection of the second leg to the second piston-piston rod unit causes the angle lever 78 to leave its locking position when it returns to the retracted position.

• A. Der Hauptschalter wird eingeschaltet, der Motor 4 über den Druckschalter 26 ans Netz gelegt und die Pumpe 5 beginnt zu laufen.
• B. Der Pumpendruck steigt über 28,5 bar ; die dritte Kolben-Kolbenstangen-Einheit 58, 59 der dritten Zylinder-Kolbenanordnung 52 bewegt sich zum äußeren Anschlag 61 und erreicht diesen bei 30 bar (Fig. 2 A bzw. Fig. 4); dabei bringt der Nocken 75 den Endschalter 73 in EIN-Stellung; die Wärmequelle 10 des Wassererhitzers 9 wird über das Zeitschaitwerk 76 eingeschaltet.
• C. Der Pumpendruck steigt über 38 bar; die zweite Kolben-Kolbenstangen-Einheit 47, 48 der zweiten Zylinder-Kolbenanordnung 40 bewegt sich zum äußeren Anschlag 60 und erreicht diesen bei 40 bar ( und wird in der anbgeänderten Ausführungsform in dieser Lage vom Winkelhebel 78 verriegelt).
• D. Der Pumpendruck erreicht 100 bar; das Entlastungs-Ventil 19 öffnet und leitet die geförderte Arbeitsflüssigkeit zurück zum Sauganschluß 6 der Pumpe 5; der hierdurch bewirkte Abfall des Pumpendrucks auf einen Wert nahe Null (auch Druck vor Rückschlag-Ventil); dieser Druckabfall führt zu einer Rückkehr der zweiten Kolben-Kolbenstangen-Einheit zum inneren Anschlag; er ist ohne Einfluß auf die Offenstellung des Entlastungs-Ventils, da dessen Steuer-Zulauf 21 an der Auslaßseite 13a des Rückschlag-Ventils 13 angeschlossen ist und von diesem der ursprüngliche Druck von 100 bar aufrechterhalten wird; aus dem gleichen Grund bleibt auch die zweite Kolben-Kolbenstangen-Einheit 47, 48 an seinem äußeren Anschlag.
• E. Aufgrund der obigen Stellungen der zweiten und dritten Kolben-Kolbenstangen-Einheiten wird von der Getriebe-Anordnung 67 das (am Hebel 70 gelegene) Auslöseglied 68 in seine aktive Grenzstellung gebracht; hierdurch wird das Zwischenglied 35 des Druckschalters 26 so weit in Richtung von dessen zweiter Grenzlage bewegt, daß der Druckschalter in AUS-Stellung geht; der Motor wird ausgeschaltet.
• F. Durch Öffnung des Auslaßventils 14 der Anlage (oder Leckage) sinkt der Druck an der Rückschlagventil-Auslaßseite 13a auf 40 bar; die zweite Kolben-Kolbenstangen-Einheit 47,48 bewegt sich zu seinem inneren Anschlag; die Getriebe-Anordnung 67 bewegt das Auslöseglied 68 in seine inaktive Stellung; das Zwischenglied 35 wird freigegeben;
• G. Der Druck sinkt auf 20 bar; der Druckschalter 26 geht in EIN-Stellung: der Motor 4 wird eingeschaltet, die Pumpe 5 fördert wieder.
• I. Bei weiterhin offenen Auslaßventil 14 (und einem gewissen Strömungswidertstand; z.B aufgrund einer angeschlossenen Spritzdüse) steigt der Druck, geregelt durch das Entlastungs-Ventil 19, an der Rückschlagventil-Auslaßseite 13a auf die eingestellten 100 bar; dabei wird ein Teil der von der Pumpe geförderten Arbeitsflüssigkeit zum Sauganschluß 6 der Pumpe rezirkuliert.
• K. Wird das Auslaßventil 14 der Anlage geschlossen, beginnt ein Zyklus analog zu vortehender Ziffer E. und folgende.

The mode of operation of the regulating and control device results from FIG. 2 and FIGS. 2A to 2D which illustrate the further operating states (for the modified embodiment from FIGS. 4 and 4A). It is therefore sufficient to explain them in key words. The following initial arrangement (Fig. 2 or Fig. 4) is assumed:
The system is separated from the mains by the main switch;
the system is without pressure; the outlet valve 14 is closed;
the safety valve 8 is set to a pressure p-ü of 165 bar;
The pressure switch 26 is designed for a switch-on pressure p-1a of 20 bar and for a switch-off pressure p-1b of 150 bar and is in the ON position
the second piston-piston rod unit 47, 48 of the second cylinder-piston arrangement 40 is up to a pressure p-2a of 38 bar at the inner stop 50, begins to extend when the pressure increases and reaches a pressure p-2b of 40 bar the outer stop 49;
the third piston-piston rod unit 58, 59 of the third cylinder-piston arrangement 52 is up to a pressure p-3a of 28.5 bar at the inner stop 61, begins to extend as the pressure increases and reaches a pressure of 30 bar the outer stop 49;
the relief valve is set to 100 bar.

• A. The main switch is turned on, the motor 4 is connected to the mains via the pressure switch 26 and the pump 5 starts to run.
• B. The pump pressure rises above 28.5 bar; the third piston-piston rod unit 58, 59 of the third cylinder-piston arrangement 52 moves to the outer stop 61 and reaches it at 30 bar (FIGS. 2A and 4); the cam 75 brings the limit switch 73 to the ON position; the heat source 10 of the water heater 9 is switched on via the timer 76.
• C. The pump pressure rises above 38 bar; the second piston-piston rod unit 47, 48 of the second cylinder-piston arrangement 40 moves to the outer stop 60 and reaches it at 40 bar (and in the modified embodiment is locked in this position by the angle lever 78).
• D. The pump pressure reaches 100 bar; the relief valve 19 opens and directs the pumped working fluid back to the suction port 6 of the pump 5; the resultant drop in pump pressure to a value close to zero (also pressure before check valve); this pressure drop leads to a return of the second piston-piston rod unit to the inner stop; it has no influence on the open position of the relief valve, since its control inlet 21 is connected to the outlet side 13a of the check valve 13 and from this the original pressure of 100 bar is maintained; for the same reason, the second piston-piston rod unit 47, 48 remains at its outer stop.
• E. Due to the above positions of the second and third piston-piston rod units, the trigger arrangement 68 (located on the lever 70) is brought into its active limit position by the gear arrangement 67; as a result, the intermediate member 35 of the pressure switch 26 is so far in Direction of its second limit position moves that the pressure switch goes to the OFF position; the engine is switched off.
• F. By opening the system outlet valve 14 (or leakage), the pressure on the check valve outlet side 13a drops to 40 bar; the second piston-piston rod unit 47, 48 moves to its inner stop; the gear assembly 67 moves the trip member 68 to its inactive position; the link 35 is released;
• G. The pressure drops to 20 bar; the pressure switch 26 goes into the ON position: the motor 4 is switched on, the pump 5 delivers again.
• I. With the outlet valve 14 still open (and a certain flow resistance; for example due to a connected spray nozzle), the pressure, regulated by the relief valve 19, increases on the check valve outlet side 13a to the set 100 bar; part of the working fluid delivered by the pump is recirculated to the suction port 6 of the pump.
• K. If the outlet valve 14 of the system is closed, a cycle begins analogously to the preceding number E. and the following.

List of the reference symbols used

1

Pressure generating unit

2nd

Valve assembly

3rd

Pressure switch unit

4th

engine

5

pump

6

Suction connection of the pump or the pressure generating unit

7a

Pressure inlet, the valve assembly

8th

Safety valve

9

Water heater

10th

Heat source, the water heater (oil burner)

11a, 11b

Connections, electrical, the heat source designed as an oil burner

12th

Pressure outlet, of the entire system, for removing the high-pressure working fluid

13

check valve

13a

Outlet side of the check valve

14

Exhaust valve

15

tube

16

Actuating lever of the outlet valve designed as a manual valve

17th

Spray nozzle, the outlet valve designed as a manual valve

18th

free

19th

Relief valve

20th

Inlet of the relief valve

21

Control inlet of the relief valve

22

Outlet, of the relief valve

23

Piston, the relief valve

24th

Valve spring, adjustable, of the relief valve

25th

Valve body, the relief valve

26

Pressure switch

26a

Contacts, movable, the pressure switch

26b, 26c

Connections, electrical, of the pressure switch

27

Cylinder-piston arrangement, first, whole

28

Switch frame

29

Cylinder, first, more firmly on the switch frame of the pressure switch

30th

Pressure connection, first, the pressure switch or the first cylinder-piston arrangement

31

Piston, first, the first cylinder-piston arrangement

32

Piston rod

31.32

Piston-piston rod unit, first

33

Body, fork-shaped, on the first piston rod

34

Working spring, in the stroke area of the body

35

Pivotal link

36

Spring, first, prestresses pontic

37

Snap arrangement

38

Contact carrier, pivoted

39

Rolls, supported by the body

40

Cylinder-piston arrangement, second, entirety

41

free

42

Cylinder, second, more stationary, the second cylinder-piston arrangement

43

Bottom of the second cylinder

44

Pressure connection, second, the second cylinder-piston arrangement

45

Cylinder end, free, of the second cylinder-piston arrangement

46

Relief opening

47

Piston, second, the second cylinder-piston arrangement

48

Piston rod, second

47.48

Piston-piston rod unit, second

49

Stop, outer, the second piston-piston rod unit

50

Stop, inner, the second piston-piston rod unit

51

Spring, second, preloads the second piston-piston rod unit

52

Cylinder-piston arrangement, third, entirety

53

Cylinder, third, more stationary, the third cylinder-piston arrangement

54

Bottom of the third cylinder

55

Pressure connection, third, the third cylinder-piston arrangement

56

Cylinder end, free, of the third cylinder-piston arrangement

57

Relief opening

58

Piston, third, the third cylinder-piston arrangement

59

Piston rod, third

58.59

Piston-piston rod unit, third

60

Stop, outer, the third piston-piston rod unit

61

Stop, inner, the third piston-piston rod unit

62

Spring, third, biases third piston-rod assembly

63

Cover of the second cylinder

64

Cover of the third cylinder

65

Limb, protruding, of the second cylinder

66

Link, protruding, of the third cylinder

67

Gear arrangement, entirety

68

Trigger link

69

Pressure surface, of the trigger member

70

lever

71

Roll, on the lever

72

Contact surface, the lever

72a

Part of the contact surface

73

Limit switch (microswitch)

73a, 73b

Connections, electrical, of the limit switch

74

Operating lever, of the limit switch,

75

Cam, on third piston-piston rod unit

76

Timer

77

Locking device

78

Angle lever

78a

Thigh, first, of the angle lift

78b

Leg, second, of the bell crank

79

Sliding surface, at the free end of the second leg

A

Longitudinal axis, the first cylinder-piston arrangement, also pressure switch longitudinal axis

B

Longitudinal axis, the second cylinder-piston arrangement

C.

Longitudinal axis, the third cylinder-piston arrangement

D

Pivot axis of the intermediate link, perpendicular to the first longitudinal axis

E

Joint axis, the lever, perpendicular to the common longitudinal plane of the cylinder-piston arrangements

F

Axis of rotation, the roller on the lever

G

Articulated axis of the angle lever

N

Operating force, external, overcomes effective spring forces on the pontic

p-1a

Switch-on pressure (20 bar), first, lower, of the pressure switch, on the first cylinder-piston arrangement

p-1b

Switch-off pressure (150 bar), first, upper, of the pressure switch, on the first cylinder-piston arrangement and nominal pressure of the system

p-2a

Pressure (38 bar), second, lower, on second cylinder-piston arrangement

p-2b

Pressure (40 bar), second, upper, on second cylinder-piston arrangement

p-3a

Pressure (28.5 bar), third, lower, third cylinder-piston arrangement

p-3b

Pressure (30 bar), third, upper, third cylinder-piston arrangement

p-ü

Pressure (165 bar), trigger pressure set on safety valve?

Claims (8)

Regulation and control device for a liquid pressure booster system, in particular a high-pressure cleaning system, containing
a pressure generating unit (1) with a pump (5) driven by a motor (4), the suction connection (6) of which the working fluid to be increased in pressure can be supplied and the pressure connection (7) is connected to a check valve (13), whose outlet side (13a) is connected to the pressure outlet (12) of the system, from which the working fluid can be removed under high pressure,
an operationally adjustable pressure relief valve (19), its inlet (20) with the pressure connection (7), its outlet (22) with the suction connection (6) and its control inlet (21) with the outlet side (13a) the check valve (13) is connected
and a pressure switch (26) with a large ON-OFF switching difference, via which the motor is connected to the mains and which contains a first cylinder-piston arrangement (27) connected to the outlet side (13a) of the check valve (13), the Piston rod (32) can be brought into contact with an intermediate member (35) which is movably mounted in the switch frame (28) and which is biased by a first spring (36) in the direction of a first limit position and via a snap arrangement (37) with a movable contact carrier (38) is coupled,
the intermediate member (35) during a movement which starts from the first limit position assumed in the depressurized state of the cylinder-piston arrangement (27) and is directed towards the second limit position, the contact carrier (38) from its ON position to an OFF position. Position transferred and wherein the intermediate member in an inverted, by the drive of the first spring (36) and against the opposing force of the cylinder-piston arrangement, the contact carrier before reaching the first Grenziage at a first lower pressure (p-1a) in transferred the ON position,
and the intermediate member (35), starting from a position predetermined by the first cylinder-piston arrangement (27), from an external force (N) only by overcoming the sum of the spring forces of the first spring (36) and snap arrangement (37) , can be moved further in the direction of its second border, characterized by
a second cylinder-piston arrangement (40) having a stationary second cylinder (42), the pressure connection (44) of which is connected to the outlet side (13a) of the check valve (13), the second valve (51) against an inner, the piston-rod unit (47, 48), which defines the retracted state, lifts the piston-piston rod unit (47, 48) from the inner stop when the pressure connection is acted on by a second lower pressure (p-2a) and at a slightly higher second upper pressure (p-2b) comes to rest against an outer stop (49),
a stationary third cylinder (53) having a third cylinder-piston arrangement (52), the pressure connection (55) of which is connected to the pressure connection (7) of the pressure generating unit (1), the third spring (62) against one internal piston stop (61), which defines the retracted state, lifts the piston-piston rod unit (58, 59) from the inner stop when the pressure connection is acted on by a predetermined third lower pressure (p-3a) and at a slightly higher third upper pressure (p -3b) comes to rest against an outer stop (60), the third upper pressure (p-3b) being greater than the first lower pressure (switch-on pressure) (p-1a) and less than the second upper pressure (p-2a) is
a gear arrangement (67) which is driven by the second piston-piston rod unit (47,48) and by the third piston-piston rod unit (58.59) and one for engagement on the intermediate member (35) of the pressure switch (26) has a releasable trigger member (68),
wherein the trigger member can be moved from an inactive limit position outside the path of movement of the intermediate member (35) to an active limit position in which it has a pressure surface (69) on the intermediate member in the sense of its movement to its second limit position and one to overcome the am Limb effective spring force attacks sufficient force (N) and
wherein the gear arrangement (67) transfers the trigger member (68) into its active limit position only when the second piston-piston rod unit (47, 48) on its outer stop (49) and the third piston-piston rod unit (58, 59) abuts its inner stop (61). Regulation and control device for a liquid pressure booster system, in particular a high-pressure cleaning system, according to claim 1, characterized in that the longitudinal axes (B, C) of the second and third cylinder-piston arrangements (40, 52) essentially in a common Longitudinal plane and parallel to each other, that the second and third cylinder-piston arrangements point in the same direction and that the gear arrangement (67) contains a lever (70) which at its first end via a joint with one to the common Longitudinal plane perpendicular hinge axis (E) is attached to the third piston rod (59), the second end provided with the pressure surface (69) forms the trigger member (68) and which has a contact surface (72) between the first and second ends, on which the free end of the second piston rod (48) can be brought to bear under pressure. Regulation and control device for a liquid pressure booster system, in particular a high-pressure cleaning system, according to claim 1, characterized in that the common longitudinal plane of the second and third cylinder-piston arrangement (40, 52) in the longitudinal axis (A) of the in the pressure switch (26) contained first cylinder-piston arrangement (27) is located that the second and third cylinder-piston arrangements point in the same direction as the first cylinder-piston arrangement and that the intermediate member (35) in the switch frame (28th ) of the pressure switch is rotatably mounted about a pivot axis (D) which is perpendicular to the common longitudinal plane. Regulation and control device for a liquid pressure booster system, in particular a high-pressure cleaning system, according to one of claims 1 to 3, characterized in that between the second piston-piston rod unit (47, 48) on the one hand and the gear arrangement (67) on the other Device for keeping the second piston-piston rod unit (47, 48) free is arranged at least in its extended position by retroactive forces. Regulation and control device for a liquid pressure booster system, in particular a high-pressure cleaning system, according to one of claims 1 to 3, characterized in that the gear arrangement (67) contains a locking device (77) which the trigger member (68) after reaching locked in its active limit position and which releases the lock when the second piston-piston rod arrangement (47, 48) assumes its retracted position. Regulation and control device for a liquid pressure booster system, in particular a high-pressure cleaning system, according to claim 2, 4 and 5, characterized in that the lever (70) of the gear arrangement (67) with the second piston-piston rod unit (47 , 48) is coupled via an angle lever (78), the hinge axis (G) of which is stationary and penetrates the angle lever near the junction of its two legs (78a, 78b) such that the first leg (78a) of the angle lever at the free end of the second piston - Piston rod unit (47, 48) rests that the second leg (78b) of the angle lever with a sliding surface (79) formed at its free end rests on the contact surface (72) of the lever (70), that at least that when the second is extended Piston-piston rod unit (47, 48) and, when the third piston-piston rod unit (58, 59) is retracted, the section (72a) of the contact surface (72) touched by the sliding surface (79) extends essentially perpendicular to a straight line which extends the hinge axis (G) cuts perpendicularly and which goes through the point of contact and that the angle lever of a return spring or through its positive or non-positive connection with the second piston-piston rod unit is tracked when it returns from the extended to the retracted position. Regulation and control device for a liquid pressure booster system, in particular a high-pressure cleaning system, according to claim 6, characterized in that the section (72a) of the contact surface (72) forms one of the boundary surfaces of a notch which is cut out of the lever (70) . Regulation and control device for a liquid pressure booster system, in particular a high-pressure cleaning system according to claim 1, with a water heater contained in the system which can be put into operation by applying a voltage to its electrical connections for heating the working fluid, characterized in that a limit switch (73) with its actuating lever (74) is arranged in the movement path of a cam (75) fixed to the third piston-piston rod unit (58, 59), so that the cam moves the limit switch to the ON position when these piston Piston rod unit is located at or near its outer limit position, which corresponds to the system at the outer stop (60) and that the electrical connections (11a, 11b) of the water heater (9) in series with the electrical connections (73a, 73b; 26b, 26c) of the limit switch (73) and the pressure switch (26) are connected to the mains or to a main switch.

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