Foam generating device for a high-pressure cleaning device and high-pressure cleaning system having a foam generating device

Abstract

A foam generating device for a high-pressure cleaning device (12) comprising a reservoir (68) for a cleaning chemical, an admixture (70) for adding the cleaning chemical to a cleaning fluid conveyed by the high-pressure cleaning device (12), and a foam nozzle (72), wherein the foam generating device (14) has an inlet channel (74) in which an injector (78) is arranged, which is in flow communication with a first suction line (80) immersed in the reservoir (68). The foam generating device is configured for use both for providing cleaning agent foam and for providing a cleaning chemical that can be added to the cleaning fluid by the high-pressure cleaning device (12).For this purpose, the foam generation device (14) has a second suction line (90) immersed in the storage container (68) and an outlet channel (96) for the cleaning chemical, wherein the second suction line (90) is in flow communication with the outlet channel (96) bypassing the injector (70), which can be detachably connected to a chemical connection device (62) of the high-pressure cleaning unit (12). Furthermore, a high-pressure cleaning system (10) with this foam generation device (14) and a high-pressure cleaning unit (12).

Description

[0001] The invention relates to a foam generation device as an accessory for a high-pressure cleaning device with a reservoir for a cleaning chemical, an admixture device for adding the cleaning chemical to a cleaning fluid conveyed by the high-pressure cleaning device, and with a foam nozzle for foaming and dispensing the mixture of the cleaning fluid and the cleaning chemical, wherein the foam generation device has an inlet channel extending from a cleaning fluid inlet to the foam nozzle and in which an injector is arranged which is in flow communication with a first suction line immersed in the reservoir for drawing the cleaning chemical from the reservoir.

[0002] Furthermore, the invention relates to a high-pressure cleaning system comprising a high-pressure cleaning device having a motor and a pump driven by the motor, and a foam generation device of the type mentioned above.

[0003] A high-pressure cleaner can be used to pressurize a cleaning fluid, preferably water, and direct it onto an object to be cleaned. The high-pressure cleaner comprises a motor, for example, an electric motor, and a pump driven by the motor. The pump has a pump inlet to which a supply hose can be connected. The cleaning fluid can be supplied to the pump of the high-pressure cleaner via the supply hose. The cleaning fluid can be pressurized by the pump and then discharged via a pressure hose. A dispensing device, such as a spray gun, a washing brush, or a high-pressure or low-pressure nozzle, can be connected to the free end of the pressure hose to apply the pressurized cleaning fluid. The dispensing device has one or more dispensing openings for applying the cleaning fluid.The pressure of the cleaning fluid pumped by the high-pressure cleaner depends on the size of at least one outlet opening. When using a relatively small outlet opening, as with a high-pressure nozzle, the pump operates in high-pressure mode, where the pressure of the pumped cleaning fluid is relatively high and can be, for example, at least 80 bar. Conversely, when using a relatively large outlet opening, as with a low-pressure nozzle or a washing brush, the pump operates in low-pressure mode, where the pressure of the pumped cleaning fluid is relatively low and, for example, a maximum of 10 bar.

[0004] To enhance cleaning effectiveness, high-pressure cleaning devices are known in which a cleaning chemical, such as a soap solution, can be added to the cleaning fluid, allowing the high-pressure cleaning device to dispense a mixture of cleaning fluid and cleaning chemical. This mixture can be directed onto the object to be cleaned via a dispensing device. In particular, a washing brush may be used as the dispensing device, for example, for cleaning a vehicle, with the high-pressure cleaning device supplying the washing brush with the mixture of cleaning fluid and cleaning chemical, which can then be applied to the vehicle. WO 2007 / 042154 A1 discloses a high-pressure cleaning device for generating such a mixture, which has a chemical connection device connected to an injector arranged in the pump's outlet line.Injectors of this type for adding a cleaning chemical to the pressurized cleaning fluid are known to those skilled in the art. They have a cross-sectional constriction, and in the region of this constriction, during low-pressure operation of the high-pressure cleaning device, a cleaning chemical supplied to the injector can be added via a transverse bore due to the Venturi effect occurring in the constriction. For storing the cleaning chemical, WO 2016 / 102075 A1 proposes a high-pressure cleaning device with a receptacle for a storage container on its exterior. The storage container can be inserted into the receptacle and connected via a supply line to the injector located in the pump's outlet line.

[0005] To enhance cleaning effectiveness, foam generating devices are also known. These devices are accessories for high-pressure cleaners and can be connected, for example, to the free end of a spray gun. The foam generating devices have a reservoir for the cleaning chemical and a mixing device for adding the cleaning chemical to the cleaning fluid supplied by the high-pressure cleaner. Furthermore, the foam generating devices have a foam nozzle for creating and dispensing the mixture of cleaning fluid and cleaning chemical as a cleaning agent foam. The cleaning agent foam can then be applied to the object to be cleaned, such as a vehicle.The mixing device has an inlet channel extending from a cleaning fluid inlet to the foam nozzle, in which an injector is arranged. This injector is in flow communication with a suction line immersed in the reservoir for drawing the cleaning chemical from the reservoir. Such foam-generating devices are known, for example, from EP 2 986 364 B1 and EP 3 003 541 B1.

[0006] The object of the present invention is to further develop a generic foam generation device as an accessory for a high-pressure cleaning device in such a way that it can be used both to provide a cleaning agent foam and to provide a cleaning chemical that can be mixed with the cleaning fluid by the high-pressure cleaning device.

[0007] This problem is solved according to the invention in a foam generation device of the type mentioned at the outset by the fact that the foam generation device has a second suction line immersed in the storage container and an outlet channel for the cleaning chemical, wherein the second suction line is in flow connection with the outlet channel bypassing the injector of the mixing device and the outlet channel is detachably connectable to a chemical connection device of the high-pressure cleaning device.

[0008] The foam-generating device according to the invention makes it possible, firstly, in a first operating mode, to generate a cleaning agent foam that can be directed onto an object to be cleaned. Secondly, in a second operating mode, the foam-generating device can supply a cleaning chemical to a high-pressure cleaning device, which can then be mixed with a cleaning fluid by the high-pressure cleaning device, so that a mixture of cleaning fluid and cleaning chemical can be dispensed by the high-pressure cleaning device.

[0009] To generate cleaning agent foam, the foam generation device according to the invention can, for example, be connected to a spray gun, which is in flow communication with the pump outlet of the high-pressure cleaner via a pressure hose. The cleaning fluid pumped by the high-pressure cleaner can be supplied to the foam generation device via the pressure hose and the spray gun. For this purpose, the foam generation device has a cleaning fluid inlet, to which an inlet channel is connected, extending to the foam nozzle of the foam generation device. The cleaning chemical can be mixed with the cleaning fluid pumped by the high-pressure cleaner by means of an injector arranged in the inlet channel.The injector is connected to the interior of the reservoir via a first suction line that extends into the reservoir, allowing the cleaning chemical to be drawn from the reservoir and mixed with the pumped cleaning fluid. The mixture of cleaning fluid and cleaning chemical can then be foamed using the foam nozzle, which dispenses a cleaning foam.

[0010] If a cleaning chemical is to be added to the cleaning fluid pumped by the high-pressure cleaner, but no cleaning agent foam is to be generated, the outlet channel of the foam generation device can be connected to the chemical connection device of the high-pressure cleaner, which is in flow communication with a fixed injector of the high-pressure cleaner. Under the influence of the cleaning fluid flowing through the fixed injector, the cleaning chemical can be drawn from the reservoir via the outlet channel and the second suction line of the foam generation device during low-pressure operation of the high-pressure cleaner and mixed with the cleaning fluid by means of the fixed injector. The foam generation device according to the invention thus offers improved application possibilities.

[0011] It is advantageous if the end section of the foam generator's outlet channel forms a connection nipple. This connection nipple facilitates the creation of a liquid-tight connection between the outlet channel and the chemical inlet of the high-pressure cleaner. For example, the connection nipple can be designed to be inserted into the chemical inlet with a sealing ring in between.

[0012] It is advantageous if the foam generation device has a fastening device for detachably attaching it to the high-pressure cleaner. With such an embodiment of the invention, the foam generation device can be attached directly to the high-pressure cleaner and assume a parked position on the high-pressure cleaner. If cleaning agent foam is to be generated using the foam generation device, it can be detached from the high-pressure cleaner and, for example, connected to a spray gun. If such use is not desired, the foam generation device can assume its parked position on the high-pressure cleaner.

[0013] In a preferred embodiment of the invention, the mounting device has a housing that circumferentially surrounds an end section of the outlet channel. This allows the connection of the outlet channel to the chemical connection device of the high-pressure cleaner to be established simultaneously when the foam generation device is attached to the high-pressure cleaner. Furthermore, the housing protects the end section of the outlet channel from damage.

[0014] It is advantageous if the mounting device has at least one fastening element located within the housing. This fastening element allows the foam generator to be easily attached to the high-pressure cleaner.

[0015] It is advantageous if the mounting device has two mounting elements, between which the end section of the outlet channel is positioned. The use of two mounting elements increases the load-bearing capacity of the foam generation device's attachment to the high-pressure cleaner. By positioning the end section of the outlet channel between the two mounting elements, stress on this end section can be minimized.

[0016] Preferably, the end section of the outlet channel is positioned centrally between the two fastening elements. This minimizes the torsional and tilting moments acting on the end section of the outlet channel when the foam generation device is in its parked position. This prevents the end section of the outlet channel from jamming when inserted into the chemical connection device.

[0017] The at least one fastening element can, for example, be designed in the shape of a hook. This makes it easier to attach the foam generation device to the high-pressure cleaner.

[0018] It is advantageous if at least one of the fastening elements has an undercut. When attaching the foam generator to the high-pressure cleaner, the undercut can be engaged by a connecting element of the high-pressure cleaner. For example, the high-pressure cleaner may be provided with a locking hook or a retaining rib, whereby the locking hook or retaining rib engages the undercut of the fastening element.

[0019] It is advantageous if the at least one fastening element is movable back and forth between a fastening position and a release position. In the fastening position, the undercut of the at least one fastening element can be engaged by a connecting element of the high-pressure cleaner, so that the foam generation device is locked to the high-pressure cleaner, and in the release position, the undercut can release the connecting element so that the foam generation device can be separated from the high-pressure cleaner.

[0020] Advantageously, the fastening device comprises an actuating element that is coupled to the at least one fastening element, wherein the at least one fastening element can be moved from the fastening position to the release position by actuating the actuating element against a spring-elastic restoring force.

[0021] The actuating element can, for example, be designed in the form of a push button.

[0022] In a particularly preferred embodiment of the foam-generating device, a first closing valve is arranged in the flow path of the cleaning chemical between the reservoir and the injector of the foam-generating device, and a second closing valve is arranged in the flow path of the cleaning chemical between the reservoir and the free end of the outlet channel, wherein both closing valves close automatically when there is no load due to a pressure differential. When the foam-generating device is used to produce cleaning agent foam, the cleaning chemical is drawn from the interior of the reservoir via the first suction line, so that downstream of the first closing valve arranged in the flow path between the reservoir and the injector, the pressure is lower than upstream of the first closing valve.The first shut-off valve is thus subjected to a pressure differential, under the influence of which the first shut-off valve automatically switches to the open position. If the foam generation device is used to supply the cleaning chemical to a fixed injector of the high-pressure cleaner, the cleaning chemical is drawn from the interior of the reservoir via the second suction line and the outlet channel, so that downstream of the second shut-off valve, which is located in the flow path between the reservoir and the free end of the outlet channel, there is a lower pressure than upstream of the second shut-off valve. The second shut-off valve is thus subjected to a pressure differential, under the influence of which the second shut-off valve assumes its open position. If the shut-off valves are not subjected to a differential pressure load, they automatically assume their closed position.This ensures that the cleaning chemical cannot unintentionally escape from the reservoir. The two shut-off valves form a leak-proof mechanism for the foaming device, preventing the cleaning chemical from leaking out unintentionally.

[0023] The two shut-off valves can, for example, be located at the free ends of the two suction lines.

[0024] In particular, it may be provided that the two shut-off valves are designed as check valves, for example as a beak valve or ball check valve. Such check valves are known to those skilled in the art and therefore do not require further explanation here.

[0025] As mentioned at the outset, the invention also relates to a high-pressure cleaning system comprising a high-pressure cleaning device and a foam generation device of the type mentioned above. The high-pressure cleaning device has a motor and a pump driven by the motor, as well as a chemical connection device which can be detachably connected to the outlet channel of the foam generation device and is in flow communication with a device-mounted injector.

[0026] The outlet channel of the foam generator can be connected to the chemical inlet of the high-pressure cleaner. When cleaning fluid flows through the injector, the cleaning chemical can be drawn from the foam generator's reservoir via the chemical inlet, the outlet channel, and the second suction line during low-pressure operation of the high-pressure cleaner. The chemical chemical is then mixed with the cleaning fluid using the injector. The high-pressure cleaner can dispense the mixture of cleaning fluid and cleaning chemical without producing cleaning foam, with the foam generator supplying the cleaning chemical to the high-pressure cleaner.

[0027] It is advantageous if the high-pressure cleaner has an accessory holder for the detachable attachment of the foam generator. With this design, the foam generator can be stored in a parking position on the high-pressure cleaner, where it can supply the cleaning chemical.

[0028] In an advantageous embodiment of the high-pressure cleaning system according to the invention, the accessory holder has a connecting device that circumferentially surrounds the chemical connection device and can be pluggably connected to a mounting device of the foam generation unit. The mounting device circumferentially surrounds an end section of the outlet channel of the foam generation unit, preferably designed as a connecting nipple. To hold the foam generation unit on the high-pressure cleaning unit, the mounting device can be inserted into or attached to the connection device of the high-pressure cleaning unit, forming a flow connection between the end section of the outlet channel and the chemical connection device. This facilitates handling of the high-pressure cleaning system when attaching the foam generation unit to the high-pressure cleaning unit.

[0029] It is advantageous if the connection device has a receiving shaft in which the chemical connection device is arranged and into which the fastening device of the foam generation device can be inserted.

[0030] Preferably, the fastening device can be inserted into the receiving shaft forming a rotationally fixed connection, so that the foam generation device can be held rotationally fixed on the high-pressure cleaning device.

[0031] It is advantageous if the connection device of the high-pressure cleaning device receives the fastening device of the foam generation device in a form-fitting manner.

[0032] Preferably, the connecting device has at least one connecting element that can be detachably connected to a fastening element of the foam generation device.

[0033] The at least one connecting element is preferably located in the receiving shaft.

[0034] In particular, it may be provided that the connecting device has two connecting elements which are arranged in the receiving shaft and each interact with a fastening element of the foam generation device.

[0035] Preferably, the chemical connection device is arranged centrally between the two connecting elements.

[0036] The at least one connecting element can be designed, for example, as a locking hook or retaining rib.

[0037] In an advantageous embodiment of the high-pressure cleaning system according to the invention, the end section of the outlet channel of the foam generation device forms a connection nipple, and the chemical connection device has a connection channel into which the connection nipple can be inserted, wherein a check valve is arranged in the connection channel, which has a closing element pre-tensioned to a closed position by means of a valve spring, wherein the closing element in the closed position is in liquid-tight contact with a sealing ring arranged in the connection channel and can be moved into an open position spaced apart from the sealing ring by inserting the connection nipple into the connection channel, wherein the connection nipple passes through the sealing ring and the latter seals the connection nipple against the channel wall of the connection channel in a liquid-tight manner.In this configuration of the high-pressure cleaning system, the check valve located in the connection channel closes the chemical connection device when the foam generator is disconnected from the high-pressure cleaner. For this purpose, the closing element of the check valve, in its closed position, forms a liquid-tight seal against a sealing ring located in the connection channel. When the foam generator is attached to the high-pressure cleaner, the end section of the foam generator's outlet channel, designed as a connection nipple, enters the connection channel, passes through the sealing ring, and moves the closing element into an open position spaced apart from the sealing ring. The sealing ring then comes into contact with the outside of the connection nipple, sealing the connection nipple against the channel wall of the connection channel.The sealing ring thus has a dual function: firstly, it forms the valve seat of the closing element, against which the closing element rests in a liquid-tight manner in the closed position; and secondly, it seals the connection nipple against the channel wall of the connecting channel when the connection nipple is inserted into the connecting channel. This dual function saves installation space and costs.

[0038] The following description of advantageous embodiments of the invention, in conjunction with the drawing, serves for further explanation. The drawing shows: Figure 1: a front view of a high-pressure cleaning system with a high-pressure cleaning unit and a foam generating device; Figure 2: a side view of the high-pressure cleaning system made of Figure 1 Figure 3: a perspective view of the high-pressure cleaning device made of Figure 1 Figure 4: a perspective view of the foam generation device made of Figure 1Figure 5: a first perspective view of the foam generation device made of Figure 1 , with a storage container hidden; Figure 6: a side view of the foam-generating device made of Figure 5 in the direction of arrow A; Figure 7: a sectional view of the foam-generating device along line 7-7 in Figure 6 Figure 8: a sectional view of the foam generation device along line 8-8 in Figure 6 Figure 9: a second perspective view of the foam-generating device made of Figure 1 , wherein the reservoir is hidden and the fastening elements of a fastening device of the foam generating apparatus are in a fastening position; Figure 10: a third perspective view of the foam generating apparatus made of Figure 1, wherein the reservoir is hidden and the fastening elements of a mounting device of the foam generating unit are in a release position; Figure 11: a sectional view of a chemical connection device of the high-pressure cleaning unit made of Figure 3 Figure 12: a sectional view of the chemical connection device made of Figure 11 with an attached, partially illustrated foam-generating device.

[0039] In the Figure 1 and 2 Figure 10 schematically illustrates an advantageous embodiment of a high-pressure cleaning system according to the invention. The high-pressure cleaning system 10 comprises an advantageous embodiment of a high-pressure cleaning device 12, which is arranged in Figure 3 schematically illustrated, and an advantageous embodiment of a foam generation device 14 according to the invention, which is shown in the Figures 4 to 10 is shown schematically.

[0040] The high-pressure cleaning device 12 has a housing 16 with a front 18, a back 20, a first longitudinal side 22 and a second longitudinal side 24, as well as a bottom 26 and a top 28. The longitudinal sides 22 and 24 extend from the back 20 to the front 18 and from the bottom 26 to the top 28, respectively.

[0041] A handle 30 is arranged on the upper side 28, immediately adjacent to the rear side 20.

[0042] A wheel 32, 34 is arranged on each of the first longitudinal side 22 and the second longitudinal side 24. The two wheels 32, 34 are mounted to rotate freely about a common axis of rotation 36.

[0043] The procedure for the high-pressure cleaning device 12 can be derived from the one described in the Figure 1 , 2 and 3The upright position shown in the illustration can be tilted backwards around the common axis of rotation 36 of the running wheels 32, 34 into a transport position, similar to a sack truck.

[0044] The device housing 16 contains an electric motor 38 and a pump 40 driven by the electric motor 38, which are arranged in Figure 1 The lines are shown as dashed lines. A cleaning fluid, preferably water, can be pressurized using pump 40.

[0045] The pump 40 has a pump inlet 42 that protrudes from the first longitudinal side 22 of the housing 16 and to which a supply hose, known per se and therefore not shown in the drawing for the sake of clarity, can be connected. The cleaning fluid to be pressurized can be supplied to the pump 40 via the supply hose.

[0046] A hose reel 44 is rotatably mounted on the rear 20 of the device housing 16. A [missing information] can be placed on the hose reel 44. Figure 2 The illustrated pressure hose 45 can be wound up and, if necessary, unwound from the hose drum 44.

[0047] The electric motor 38 is supplied with energy via an electrical cable not shown in the drawing, which is wound onto a storage device 46 arranged on the first longitudinal side 22 and can be removed from it for the operation of the high-pressure cleaning device 12.

[0048] On the front 18 of the device housing 16, a first accessory holder 48, a second accessory holder 50 and a third accessory holder 52 are arranged for holding accessories of the high-pressure cleaning device 12. The first accessory holder 48 serves to hold a spray gun known per se, the second accessory holder 50 serves to hold a spray nozzle known per se, and the third accessory holder serves to hold a spray lance known per se.

[0049] For dispensing the pressurized cleaning fluid, the pump 40 has an outlet line 54 which is in flow connection with the pressure hose 45, so that the pressurized cleaning fluid can be dispensed via the pressure hose 45. A dispensing device, for example a spray gun or spray nozzle or a foam generator 14, can be connected to the free end of the pressure hose 45.

[0050] The foam generation device 14 forms a further accessory of the high-pressure cleaning device 12 and can assume a parking position on the first longitudinal side 22 of the device housing 16, as shown in the Figure 1 and 2 is shown, and can be removed from the first long side 22 if necessary.

[0051] To detachably hold the foam generation device 14 on the high-pressure cleaning device 12, a further accessory holder 56 is arranged on the first longitudinal side 22, which has a recess 58 and a connecting device 59 arranged above the recess 58. The connecting device 59 has a receiving shaft 60 in which a chemical connection device 62 and two connecting elements 64, 66 are arranged, which are explained in more detail below.

[0052] The foam generation device 14 has a storage container 68 for holding a cleaning chemical and an mixing device 70 for mixing the cleaning chemical with the cleaning fluid pressurized by the high-pressure cleaning device 12. The foam generation device 14 also has a foam nozzle 72, with the aid of which the mixture of cleaning fluid and cleaning chemical can be foamed and then applied.

[0053] The mixing device 70 has a base body 71 that forms an inlet channel 74. The inlet channel 74 extends from a cleaning fluid inlet 76 to the foam nozzle 72. An injector 78 is arranged in the inlet channel 74 at a distance from the cleaning fluid inlet 76. The injector 78 forms a throttling point in the form of a cross-sectional constriction of the inlet channel 74 in a known manner. A first suction line 80 of the foam generation device, which extends into the reservoir 68, opens into the area of ​​the cross-sectional constriction. The first suction line 80 extends from the injector 78 into the interior of the reservoir 68. It has a rigid first line section 82, which is formed by the base body 71, and to which a flexible second line section 84 is connected, which also extends into the reservoir 68. The second line section 84 can, for example, be designed in the form of a suction hose.

[0054] In addition to the first suction line 80, the foam generation device 14 has a second suction line 90 that extends into the reservoir 68. The second suction line 90 also has a rigid first section 92, formed by the base body 71, to which a flexible second section 94 is connected. The flexible second section 94 extends into the reservoir 68. Unlike the first suction line 80, the second suction line 90 does not extend to the injector 78; instead, an outlet channel 96 of the foam generation device 14 is connected to the second suction line 90, the free end of which forms a connection nipple 98. The outlet channel 96 is also formed by the base body 71.

[0055] The outlet channel 96 is oriented transversely to the inlet channel 74, with the connecting nipple 98 being surrounded by a housing 100 of a fastening device 102 of the foam generation device 14. This is particularly evident from Figure 7 Clearly. The fastening device 102 is designed and configured for the detachable fastening of the foam generation device 14 to the high-pressure cleaning device 12. For this purpose, the fastening device 102 can be pluggably connected to the connecting device 59. In the illustrated embodiment, the housing 100 of the fastening device 102 can be inserted into the receiving shaft 60 of the device housing 16 in a form-fitting and rotationally fixed manner.

[0056] The fastening device 102 comprises a base part 101, which is formed by the base body 71, and a fastening part 109, which is attached to the base part 101 between a Figure 7 , 8 and 9 illustrated mounting position and one in Figure 10The release position shown is held movable back and forth. The base part 101 forms a bottom wall 103 and two opposing side walls 105, 107 of the housing 100 of the fastening device 102.

[0057] The fastening element 109 has a ceiling wall 112 of the housing 100 and two fastening elements 104, 106, which are hook-shaped and between which the connecting nipple 98 of the outlet channel 96 is arranged centrally. The fastening elements 104, 106 interact with the connecting elements 64, 66 arranged in the receiving shaft 60. For this purpose, the fastening elements 104, 106 each have an undercut 108 which can be engaged by a connecting element 64, 66 when the housing 100 is inserted into the receiving shaft 60.

[0058] In addition to the ceiling panel 112 and the fastening elements 104, 106, the fastening part 109 has an actuating element 113, which is rigidly connected to the fastening elements 104, 106 via a coupling element 115 slidably mounted on the base part 101. The actuating element 113 is designed in the form of a push button 116. By actuating the push button 116, the fastening part 109 can be moved from the fastening position to the release position against a spring-elastic restoring force exerted by a return spring 118. The return spring 118 is supported on one side by an underside of the push button 116 and on the other side by an adjusting element 120 of the mixing device 70.

[0059] The adjusting element 120 is pivotably mounted on the base body 71. The mixing ratio between the cleaning fluid and the added cleaning chemical can be adjusted using the adjusting element 120.

[0060] In the fastening position, the fastening elements 104, 106 are located at a greater distance from the bottom wall 103 of the housing 100 than in the release position. This is particularly evident from the Figure 9 and 10 Clearly. In the fastening position, the connecting elements 64, 66 can engage the undercuts 108 of the fastening elements 104, 106, so that the foam generating device 14 is locked onto the high-pressure cleaning device 12. In the release position, the undercuts 108 are spaced away from the connecting elements 64, 66, meaning that the fastening elements 104, 106 release the connecting elements 64, 66, so that the foam generating device 14 can be detached from the high-pressure cleaning device.

[0061] In the illustrated embodiment of the foam-generating device 14, a first closing valve 109 is arranged at the free end of the first suction line 80, and a second closing valve 111 is arranged at the free end of the second suction line 90. In the absence of a pressure differential, the closing valves 109 and 111 automatically assume their closed position. This ensures that the cleaning chemical cannot unintentionally escape from the storage container 68 via the suction lines 80 and 90.

[0062] The chemical connection device 62 has a connection channel 122 that extends through a side wall 124 of the housing 16 of the high-pressure cleaning device 12 and in which a check valve 126 is arranged, which has a closing element 128 that is in a Figure 11In the closed position shown, the valve spring 130 acts as a liquid-tight seal against a sealing ring 132 located in the connection channel 122. The sealing ring 132 forms a valve seat for the check valve 126. The check valve 126 automatically assumes the closed position when the foam generation device 14 is disconnected from the high-pressure cleaning device 12. When the foam generation device 14 is connected to the high-pressure cleaning device 12, the connecting nipple 98 enters the connection channel 122, passes through the sealing ring 132, and moves the closing element 128 against the spring force of the valve spring 130 into a position shown in Figure 12The open position shown is such that the closing element 128 is spaced apart from the sealing ring 132, and the sealing ring 132 comes into contact with the outside of the connecting nipple 98, sealing it against a channel wall 134 of the connecting channel 122 in a liquid-tight manner. The sealing ring 132 thus has a dual function: firstly, it forms the valve seat of the check valve 126, and secondly, it seals the connecting nipple 98 against the channel wall 134 of the connecting channel 122 when the foam generation device 14 is in its parked position on the high-pressure cleaning device 12.

[0063] As already mentioned, a cleaning agent foam can be generated by means of the foam-generating device 14, which can be directed onto an object to be cleaned, for example, a vehicle surface. To generate the cleaning agent foam, the foam-generating device 14 can be detached from the high-pressure cleaning device 12 and, for example, connected to a spray gun, so that cleaning fluid can be supplied to the mixing device 70 of the foam-generating device 14 from the high-pressure cleaning device 12. The cleaning fluid can flow through the inlet channel 74 and, in particular, the injector 78. The injector 78 forms a cross-sectional constriction in a known manner.This results in the cleaning chemical being drawn from the reservoir 68 at the cross-sectional constriction due to the Venturi effect occurring via the first suction line 80 and mixed with the cleaning fluid supplied by the high-pressure cleaning device 12. The mixture then reaches the foam nozzle 72, with the aid of which the mixture can be foamed in a known manner and subsequently discharged via a nozzle outlet 110 of the foam nozzle 72. The first closing valve 109 assumes an open position, thus allowing the flow path of the cleaning chemical from the reservoir 68 to the injector 78.

[0064] The cleaning chemical located in the reservoir 68 can be added to the cleaning fluid not only to create a cleaning agent foam. In some cases, while it is helpful to add a cleaning chemical to the cleaning fluid supplied by the high-pressure cleaner 12 to increase the cleaning effect, the mixture should not be additionally foamed and applied as a cleaning agent foam, but rather directed directly onto the object to be cleaned. For example, the mixture can be applied to the object to be cleaned using a washing brush connected to the free end of the pressure hose 45.

[0065] To mix the cleaning chemical with the pressurized cleaning fluid inside the high-pressure cleaning device 12, the foam generation device 14 can extend its Figure 1The foam generator 14 assumes the parking position shown. As already mentioned, in the parking position, the housing 100 of the mounting device 102 is positively engaged in the receiving shaft 60 of the high-pressure cleaner. This results in the connecting nipple 98 of the foam generator 14, surrounded by the housing 100 of the mixing device 70, being inserted into the chemical connection device 62 with the sealing ring 132 interposed. The chemical connection device 62 is in flow communication via a connecting line 112 with a fixed injector 114 of the high-pressure cleaner 12, which is located in the outlet line 54 of the pump 40.By means of the fixed injector 114, the cleaning chemical can be drawn from the reservoir 68 of the foam generation device 14 during low-pressure operation of the high-pressure cleaning device 12 by means of the cleaning fluid flowing through the fixed injector 114. The cleaning chemical then reaches the fixed injector 114 via the second suction line 90, the connection nipple 98, the chemical connection device 62, and the connecting line 112. The second shut-off valve 111 assumes its open position, thus allowing the flow path of the cleaning chemical from the reservoir 68 to the connection nipple 98.

[0066] By means of the device-mounted injector 114, a mixture of cleaning fluid and cleaning chemical can be produced, which can be directed at an object to be cleaned without forming a cleaning agent foam.

[0067] The cleaning chemical is drawn in by the fixed injector 114 during low-pressure operation of the high-pressure cleaner 12. Such low-pressure operation occurs when the cleaning fluid is dispensed via a nozzle with a relatively large outlet opening, as is the case, for example, with a wash brush connected to the free end of the pressure hose 45. If the nozzle has only a relatively small outlet opening, a relatively high fluid pressure builds up in the outlet line 54 of the pump 40 and the connected pressure hose 45. As a result, no cleaning chemical can be drawn from the reservoir 68 by the fixed injector 114.

[0068] The high-pressure cleaning system 10 enables the dispensing of a pressurized cleaning fluid, a mixture of cleaning fluid and a cleaning chemical, or a cleaning agent foam. A cleaning agent foam can be generated using the foam generation device 14, or a cleaning chemical can be provided that can be mixed with the pressurized cleaning fluid by the high-pressure cleaning unit 12.

Claims

1. Foam generating device as an accessory for a high-pressure cleaning device with a reservoir (68) for a cleaning chemical, an admixture (70) for adding the cleaning chemical to a cleaning fluid conveyed by the high-pressure cleaning device (12), and with a foam nozzle (72) for foaming and dispensing the mixture of the cleaning fluid and the cleaning chemical, wherein the foam generating device (14) has an inlet channel (74) extending from a cleaning fluid inlet (76) to the foam nozzle (72) and in which an injector (78) is arranged, which is in flow communication with a first suction line (80) immersed in the reservoir (68) for drawing the cleaning chemical from the reservoir (68), characterized by the fact thatThe foam generation device (14) has a second suction line (90) immersed in the storage container (68) and an outlet channel (96) for the cleaning chemical, wherein the second suction line (90) is in flow connection with the outlet channel (96) bypassing the injector (70) of the mixing device (70) and the outlet channel (96) is detachably connectable to a chemical connection device (62) of the high-pressure cleaning device (12).

2. Foam generating device according to claim 1, characterized by the fact that an end section of the outlet channel (96) forms a connection nipple (98).

3. Foam generating device according to claim 1 or 2, characterized by the fact that the foam generating device (14) has a fastening device (102) for detachably fastening the foam generating device (14) to the high-pressure cleaning device (12).

4. Foam generating device according to claim 3, characterized by the fact thatthe fastening device (102) has a housing (100) that surrounds an end section of the outlet channel (96) in a circumferential direction.

5. Foam generating device according to claim 4, characterized by the fact that the fastening device (102) has at least one fastening element (104, 106) arranged in the housing (100), and in particular characterized byat least one of the following: - the fastening device (102) has two fastening elements (104, 106) between which the end section of the outlet channel (96) is arranged; - the at least one fastening element (104, 106) forms an undercut (108); - the at least one fastening element (104, 106) is movable back and forth between a fastening position and a release position, wherein the fastening device (102) preferably has an actuating element (113) which is coupled to the at least one fastening element (104, 106), wherein the at least one fastening element (104, 106) can be moved from the fastening position to the release position by actuating the actuating element (113) against a spring-elastic restoring force.

6. Foam generating device according to one of the preceding claims, characterized by the fact thata first closing valve (109) is arranged in the flow path of the cleaning chemical between the storage container (68) and the injector (78), and a second closing valve (111) is arranged in the flow path of the cleaning chemical between the storage container (68) and the free end of the outlet channel (96), wherein the two closing valves (109, 111) close automatically when there is no pressure differential.

7. Foam generating device according to claim 6, characterized by the fact that at least one of the following applies: - the first closing valve (109) is arranged at the free end of the first suction line (80) and the second closing valve (111) is arranged at the free end of the second suction line (90); - the two closing valves (109, 111) are designed as check valves, in particular as a beak valve or ball check valve.

8. High-pressure cleaning system comprising a high-pressure cleaning device (12) comprising a motor (38) and a pump (40) driven by the motor (38), and comprising a foam generating device (14) according to one of the preceding claims, characterized by the fact that the high-pressure cleaning device (12) has a chemical connection device (62) which can be detachably connected to the outlet channel (96) of the foam generation device (14) and is in flow communication with a device-fixed injector (114) of the high-pressure cleaning device (12).

9. High-pressure cleaning system according to claim 8, characterized by the fact that the high-pressure cleaning device (12) has an accessory holder (56) for detachably holding the foam generation device (14).

10. High-pressure cleaning system according to claim 9, characterized by the fact thatthe accessory holder (56) has a connecting device (59) that surrounds the chemical connection device (62) in a circumferential direction and can be pluggably connected to a fastening device (102) of the foam generation device (14), wherein the fastening device (102) surrounds an end section of the outlet channel (96) of the foam generation device (14) in a circumferential direction, in particular characterized by the fact that the connecting device (59) has a receiving shaft (60) in which the chemical connection device (62) is arranged and into which the fastening device (102) of the foam generation device (14) can be inserted, and preferably characterized by the fact that the fastening device (102) can be inserted into the receiving shaft (60) forming a rotationally fixed connection.

11. High-pressure cleaning system according to claim 10, characterized by the fact thatthe connecting device (59) has at least one connecting element (64, 66) which can be detachably connected to a fastening element (104, 106) of the foam generating device (14).

12. High-pressure cleaning system according to claim 11, characterized by the fact that that at least one connecting element (64, 66) is arranged in the receiving shaft (60).

13. High-pressure cleaning system according to claim 12, characterized by the fact that the connecting device (59) has two connecting elements (64, 66) which are arranged in the receiving shaft (60) and each interact with a fastening element (104, 106) of the foam generating device (14).

14. High-pressure cleaning system according to claim 13, characterized by the fact that The chemical connection device (62) is arranged centrally between the two connecting elements (64, 66).

15. High-pressure cleaning system according to one of claims 8 to 14, characterized by the fact thatThe end section of the outlet channel (86) of the foam generation device (14) forms a connection nipple (98), and the chemical connection device (62) has a connection channel (122) into which the connection nipple (98) can be inserted, wherein a check valve (126) is arranged in the connection channel (122) which has a closing element (128) biased into a closed position by means of a valve spring (130), wherein the closing element (128) in the closed position is in a liquid-tight manner against a sealing ring (132) arranged in the connection channel (122) and can be moved into an open position spaced apart from the sealing ring (132) by inserting the connection nipple (88) into the connection channel (122), wherein the connection nipple (98) extends through the sealing ring (132) and the sealing ring (132) protects the connection nipple (98) from a channel wall (134) of the connection channel (122). It seals liquid-tight.

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