Liquid-dispensing apparatus for a high-pressure cleaning device

Abstract

The invention relates to a liquid-dispensing apparatus (10) for a high-pressure cleaning device, comprising a liquid supply part (12) having an inlet channel (18) oriented coaxially with a longitudinal axis (16), and further comprising a nozzle assembly (32), which can be continuously moved back and forth relative to the liquid supply part (12) between a first end position and a second end position, and which has a main nozzle (66) and at least one additional nozzle (48, 50) arranged to be radially offset from the main nozzle (66). The liquid jet (49, 51) emanating from the at least one additional nozzle (48, 50) is inclined towards the liquid jet (67) emanating from the main nozzle (66). In the first end position of the nozzle assembly (32), the inlet channel (18) is in a flow connection only to the main nozzle (66), and, during the transition of the nozzle assembly (32) from the first end position into the second end position, a flow connection can be enabled in order to continuously increase the volume flow rate of liquid from the inlet channel (18) to the at least one additional nozzle (48, 59). In order to allow a liquid jet to be formed that has an improved jet pattern, the at least one additional nozzle (48, 50) is arranged to be axially offset from the main nozzle (66) in the flow direction (31) of the liquid.

Description

[0001] LIQUID DISPENSER FOR A HIGH-PRESSURE CLEANER

[0002] The invention relates to a liquid dispensing device for a high-pressure cleaning device comprising a liquid supply section with an inlet channel for pressurized liquid aligned coaxially to a longitudinal axis, and further comprising a nozzle arrangement which is continuously displaceable back and forth relative to the liquid supply section between a first end position and a second end position and which has a main nozzle and at least one auxiliary nozzle arranged radially offset to the main nozzle for dispensing the liquid, wherein the liquid jet emanating from the at least one auxiliary nozzle is inclined towards the liquid jet emanating from the main nozzle.and wherein in the first end position of the nozzle arrangement the inlet channel is only in flow communication with the main nozzle and, during the transition of the nozzle arrangement from the first end position to the second end position, a flow connection for the continuous increase of the flow of liquid from the inlet channel to the at least one additional nozzle can be released.

[0003] A liquid dispensing device of this type can be used to dispense liquid that has been pressurized by a high-pressure cleaning device. The liquid dispensing device comprises a liquid supply section with an inlet channel for pressurized liquid that is aligned coaxially with a longitudinal axis, and also includes a nozzle assembly that is continuously displaceable back and forth relative to the liquid supply section between a first end position and a second end position. For dispensing the pressurized liquid, the nozzle assembly has a main nozzle and at least one auxiliary nozzle, the auxiliary nozzle being arranged radially offset from the main nozzle with respect to the longitudinal axis. The at least one auxiliary nozzle is configured and designed such that the liquid jet emanating from the at least one auxiliary nozzle is inclined towards the liquid jet emanating from the main nozzle.In the first end position of the nozzle assembly, the inlet channel is only in flow communication with the main nozzle, meaning that in this first end position, pressurized liquid can only be discharged via the main nozzle. During the transition of the nozzle assembly from the first end position to the second end position, a flow connection is opened to continuously increase the flow of liquid from the inlet channel to the at least one auxiliary nozzle. This means that during the transition of the nozzle assembly from the first end position to the second end position, the inlet channel increasingly comes into flow communication with the at least one auxiliary nozzle as well, so that pressurized liquid can be discharged via the main nozzle and also via the at least one auxiliary nozzle.

[0004] If the liquid supplied to the dispensing device is dispensed only through the main nozzle, it will have a relatively high discharge pressure, which is essentially determined by the flow rate of the high-pressure cleaner and the size of the main nozzle's outlet. If the liquid supplied to the dispensing device is dispensed not only through the main nozzle but also through at least one auxiliary nozzle, the overall discharge pressure will be lower, since the liquid is dispensed not only through the main nozzle but also through the outlet of at least one auxiliary nozzle. By adjusting the nozzle arrangement, the discharge pressure of the liquid can therefore be continuously varied while maintaining a constant flow rate of the high-pressure cleaner.This allows the discharge pressure of the liquid dispensed by the liquid dispensing device to be adjusted to the surface properties of the area to be cleaned. More sensitive surfaces can be treated with liquid at a lower discharge pressure than less sensitive surfaces. The at least one auxiliary nozzle is arranged radially offset from the main nozzle with respect to its longitudinal axis, and the liquid jet emanating from the at least one auxiliary nozzle is inclined towards the liquid jet emanating from the main nozzle, such that the liquid jet from the at least one auxiliary nozzle is directed towards the liquid jet emanating from the main nozzle.This results in the liquid jet emanating from the at least one additional nozzle meeting the liquid jet emanating from the main nozzle at a distance from the liquid dispensing device, and the liquid jets then forming a common liquid jet that can be directed onto the surface to be cleaned.

[0005] A liquid dispensing device of the type mentioned above is known from EP 3 200 928 Bl. In this liquid dispensing device, the liquid jets emanating from the main nozzle and the at least one auxiliary nozzle can be combined into a single liquid jet. However, due to manufacturing tolerances of the main nozzle and the at least one auxiliary nozzle, the combined liquid jet does not always form a uniform jet pattern in the form of a compact liquid jet with a clearly defined geometry. This can impair the achievable cleaning performance.

[0006] The object of the present invention is therefore to design a liquid dispensing device of the type mentioned at the outset in such a way that the liquid dispensing device enables the formation of a liquid jet with an improved jet pattern.

[0007] This problem is solved in a liquid dispensing device of the generic type according to the invention by arranging the at least one auxiliary nozzle axially offset from the main nozzle in the direction of liquid flow. In the liquid dispensing device according to the invention, the at least one auxiliary nozzle is arranged axially offset from the main nozzle in the direction of liquid flow. It has been shown that such positioning of the at least one auxiliary nozzle relative to the main nozzle produces a liquid jet with an improved spray pattern.The invention incorporates the insight that the liquid jets emanating from the main nozzle and the at least one auxiliary nozzle widen with increasing distance from the respective nozzle outlet opening, wherein the liquid jet emanating from the main nozzle has a width in the impact zone of the liquid jet emanating from the at least one auxiliary nozzle that, even taking manufacturing tolerances into account, is at least as large as the width of the liquid jet emanating from the at least one auxiliary nozzle. In the impact zone, the liquid jets emanating from the main nozzle and the at least one auxiliary nozzle merge to form a common liquid jet, the geometry of which is determined by the liquid jet emanating from the main jet, which thus forms a kind of "guide jet".It has been shown that this results in the combined liquid jet having a very compact geometry with a clearly defined jet pattern.

[0008] It may be provided that the nozzle geometry of the at least one auxiliary nozzle is inclined towards the main nozzle. Such an inclination of the nozzle geometry ensures, in a structurally simple manner, that the liquid jet emanating from the at least one auxiliary nozzle is inclined towards the liquid jet emanating from the main nozzle and intersects the liquid jet emanating from the main nozzle at a distance from the liquid dispensing device.

[0009] The angle of inclination of the nozzle geometry of the at least one auxiliary nozzle relative to the main nozzle can be, for example, 3° to 10°, preferably about 8°. For example, the at least one auxiliary nozzle can have an outlet opening that opens into a nozzle slot oriented transversely to the longitudinal axis, which has two opposing slot walls, the slot walls being inclined towards the main nozzle. The angle of inclination can be, for example, 3° to 10°, particularly about 8°.

[0010] In an advantageous embodiment of the invention, the axial offset of the at least one auxiliary nozzle in the flow direction of the liquid relative to the main nozzle is at least 5 mm, in particular at least 8 mm, for example 10 to 14 mm. It has been shown that this results in a particularly compact liquid jet with a defined jet pattern.

[0011] It is advantageous if a nozzle inlet channel is arranged upstream of the main nozzle and upstream of at least one auxiliary nozzle, with the nozzle inlet channels being aligned parallel to each other. This allows for a particularly compact design of the liquid dispensing device and reduces its manufacturing costs.

[0012] Preferably, the main nozzle and the at least one auxiliary nozzle are designed as flat jet nozzles. A fan-shaped liquid jet can be generated using flat jet nozzles. Due to the axially offset arrangement of the at least one auxiliary nozzle relative to the main nozzle in the direction of liquid flow, the fan-shaped liquid jet emanating from the main nozzle has a width in the impact zone of the fan-shaped liquid jet emanating from the at least one auxiliary nozzle that is at least as wide as the liquid jet emanating from the at least one auxiliary nozzle.

[0013] It is advantageous if the opening angle of the fan-shaped liquid jet emanating from the main nozzle is greater than the opening angle of the fan-shaped liquid jet emanating from the at least one auxiliary nozzle. The opening angle of the liquid jet emanating from the main nozzle can, for example, be 22° to 30°, particularly 25°. The opening angle of the liquid jet emanating from the at least one auxiliary nozzle can, for example, be 14° to 21°, particularly 20°.

[0014] It is advantageous if the main nozzle is arranged coaxially to the longitudinal axis of the inlet channel and the nozzle arrangement includes two auxiliary nozzles arranged symmetrically to the longitudinal axis. With respect to the longitudinal axis, the two auxiliary nozzles are offset from the main nozzle in the direction of fluid flow and positioned mirror-symmetrically to each other. It has been shown that this results in a particularly compact, combined fluid jet with a defined spray pattern and a predefinable discharge pressure.

[0015] In an advantageous embodiment of the invention, the nozzle assembly comprises a first nozzle body, which forms the at least one auxiliary nozzle and which has a through-channel aligned coaxially to the longitudinal axis of the inlet channel, in which a second nozzle body, forming the main nozzle, is fixed. In such an embodiment, the nozzle assembly comprises a first component in the form of the first nozzle body and a second component in the form of the second nozzle body, wherein the components can be made of different materials. For example, the first nozzle body can be made of a plastic material and the second nozzle body can be made of metal, for example, steel. The first nozzle body forms the at least one auxiliary nozzle, and the second nozzle body forms the main nozzle. When the nozzle assembly is in its first end position, the inlet channel is only in flow communication with the main nozzle.The main nozzle is therefore subjected to considerable pressure. During the transition of the nozzle assembly from the first end position to the second end position, the inlet channel is in contact not only with the main nozzle but increasingly also with at least one auxiliary nozzle. As a result, fluid is discharged through both the main nozzle and the at least one auxiliary nozzle, thus reducing the pressure of the fluid upstream of the main and auxiliary nozzles while maintaining the same delivery rate of the high-pressure cleaner. Consequently, the auxiliary nozzles are subjected to lower pressure during operation of the fluid dispensing device and can be made of a less pressure-resistant material than the main nozzle.

[0016] It is advantageous if the second nozzle body forms an interference fit with the through-channel of the first nozzle body. In such an embodiment of the invention, the second nozzle body is pressed into the through-channel of the first nozzle body.

[0017] In an advantageous embodiment of the invention, the second nozzle body has a connection section which, in the first end position of the nozzle arrangement, is liquid-tight against a connecting member of the liquid supply part which is in flow communication with the inlet channel and interrupts a flow connection between the connecting member and the at least one additional nozzle, and which, in combination with the connecting member, limits an annular gap of adjustable width and / or adjustable length during the transition of the nozzle arrangement from the first end position to the second end position for the continuous increase of the flow of liquid from the connecting member to the at least one additional nozzle.

[0018] In such an embodiment of the invention, the liquid supply section has a connecting element that is in flow communication with the inlet channel, and the second nozzle body, which forms the main nozzle, has a connecting section. In the first end position of the nozzle assembly, the connecting section is in a liquid-tight seal against the connecting element. This allows pressurized liquid to be supplied to the main nozzle via the inlet channel, the connecting element, and the connecting section, so that the liquid can be discharged through the main nozzle. Simultaneously, in the first end position of the nozzle assembly, the connecting section interrupts the flow connection between the connecting element and the at least one auxiliary nozzle, so that liquid cannot flow to the at least one auxiliary nozzle in the first end position of the nozzle assembly. Thus, in the first end position of the nozzle assembly, only the main nozzle is supplied with liquid.During the transition of the nozzle assembly from the first end position to the second end position, the connecting section, in combination with the connecting element, defines an annular gap whose width and / or length changes continuously during the transition of the nozzle assembly from the first end position to the second end position, thereby continuously increasing the flow of liquid from the connecting element to the at least one auxiliary nozzle. During the transition of the nozzle assembly from the first end position to the second end position, the annular gap, which changes in width and / or length, enables a flow connection from the connecting element to the at least one auxiliary nozzle, with the flow of liquid increasing the closer the nozzle assembly gets to its second end position.The increasing fluid flow rate is achieved by continuously increasing the width and / or decreasing the length of the annular gap as the nozzle assembly transitions from its first to its second end position. Increasing the width and / or decreasing the length of the annular gap reduces the flow resistance it exerts on the fluid, thus allowing the fluid flow rate to increase continuously as the nozzle assembly transitions from its first to its second end position.By moving the nozzle assembly from the first end position towards the second end position, liquid can be supplied not only to the main nozzle but also increasingly to the at least one auxiliary nozzle, so that the liquid can be discharged via the main nozzle and the at least one auxiliary nozzle. With a constant delivery rate of the high-pressure cleaner, the discharge pressure of the liquid decreases progressively as the nozzle assembly approaches its second end position. The user can thus adjust the discharge pressure of the liquid by moving the nozzle assembly. Preferably, the connection section of the second nozzle body protrudes from the first nozzle body in the opposite direction to the flow of the liquid.

[0019] In a preferred embodiment of the invention, the connecting element is designed as a pipe stub.

[0020] In a preferred embodiment of the invention, the liquid supply section comprises a jet tube that forms the inlet channel and has an end section with a cup-shaped recess into which the inlet channel opens. The connecting element is attached to the inlet channel and projects into the recess, and the nozzle assembly is immersed in the recess and axially displaceable within it. In such an embodiment of the invention, the liquid supply section comprises a jet tube that can be connected, for example, to a spray gun, which is connected to a high-pressure cleaning device via a supply line, such as a pressure hose. For this purpose, the jet tube can have a coupling element, such as a bayonet coupling element.At its end facing away from the coupling element, the nozzle tube has a cup-shaped recess into which the inlet channel opens. The connecting element of the second nozzle body is attached to the inlet channel and projects into the recess. On the side of the recess opposite the connecting element, the nozzle assembly enters the recess, where it is held axially displaceable. The nozzle assembly can thus be continuously moved back and forth within the recess between the first and second end positions.

[0021] It is advantageous if the liquid dispensing device has a sleeve that is rotatably and axially displaceably mounted via a thread on the end section of the jet tube forming the recess, and which is rotatably but axially immovably connected to the nozzle assembly. The sleeve provides a handle for the user, allowing the user to continuously move the nozzle assembly back and forth between the first and second end positions. For this purpose, the sleeve is connected via a thread to the end section of the jet tube, into whose recess the nozzle assembly is inserted. By rotating the sleeve around the end section, the sleeve can be axially displaced relative to the end section. The sleeve is rotatably and axially immovably connected to the nozzle assembly, so that an axial movement of the sleeve is transmitted to the nozzle assembly, whereas the rotational movement of the sleeve is not transmitted to the nozzle assembly.

[0022] The connection of the sleeve to the nozzle assembly can be achieved, for example, by the sleeve having an annular groove on the inside into which a flange of the nozzle assembly is inserted.

[0023] The following description of an advantageous embodiment of the invention, in conjunction with the drawing, serves for further explanation. The drawing shows:

[0024] Figure 1: a longitudinal sectional view of a liquid dispensing device;

[0025] Figure 2: a longitudinal sectional view of an outlet section of the liquid dispensing device from Figure 1;

[0026] Figure 3: an enlarged view of detail B from Figure 2, in which a nozzle arrangement of the liquid dispensing device assumes a first end position;

[0027] Figure 4: a representation corresponding to Figure 3, wherein the nozzle arrangement assumes a second end position;

[0028] Figure 5: a perspective view of the outlet section shown in Figure 2; Figure 6: a perspective view of the outlet section during operation of the liquid dispensing device.

[0029] The drawing schematically shows an advantageous embodiment of a liquid dispensing device according to the invention for a high-pressure cleaning device and is labelled with reference numeral 10.

[0030] The liquid dispensing device 10 comprises a liquid supply section 12 with a jet tube 14, which has an inlet channel 18 aligned coaxially with a longitudinal axis 16 and forms a coupling element at a first end region 20, which in the illustrated embodiment is designed as a bayonet coupling element 22. By means of the coupling element, the jet tube 14 can be connected, for example, to a spray gun known per se, which is connected to a high-pressure cleaning device via a pressure hose. Liquid, pressurized by the high-pressure cleaning device, can be supplied to the jet tube 14 via the pressure hose and the spray gun and directed onto a surface to be cleaned by means of the liquid dispensing device 10.

[0031] A second end region 24 of the jet tube 14, facing away from the first end region 20, forms an extension 26 that defines an axially oriented, cup-shaped recess 28. The inlet channel 18 opens into the recess 28. In the direction of fluid flow, a connecting element, coaxially aligned with the inlet channel 18, connects to the recess 28 and is designed as a pipe stub 30 in the illustrated embodiment. The direction of fluid flow is illustrated in the drawing by arrow 31.

[0032] On the side of the recess 28 facing away from the pipe stub 30, a nozzle assembly 32 is inserted into the recess 28, with a sealing ring 34 interposed, which surrounds the nozzle assembly 32 circumferentially. The nozzle assembly 32 has a first nozzle body 36, which is made of a plastic material and has a through-channel 38 aligned coaxially with the longitudinal axis 14, in which a second nozzle body 40 of the nozzle assembly 32 is fixed. The second nozzle body 40 is made of metal, preferably steel, and is pressed into the through-channel 38.

[0033] The first nozzle body 36 has a first nozzle inlet channel 42 and a second nozzle inlet channel 44, which are aligned parallel to the longitudinal axis 16. The first nozzle inlet channel 42 extends from an annular space 46, which circumferentially surrounds the pipe stub 30 within the recess 28, to a first auxiliary nozzle 48, which is formed by the first nozzle body 36. The second nozzle inlet channel 44 extends from the annular space 46 to a second auxiliary nozzle 50, which is also formed by the first nozzle body 36.

[0034] The two additional nozzles 48, 50 are arranged symmetrically to the longitudinal axis 16 and are designed as flat jet nozzles, with the aid of which a liquid jet 49 or 51, respectively, can be discharged in a fan-shaped pattern within a jet plane. This is particularly evident from Figure 6. The opening angle of the liquid jets 49 and 51 is approximately 20° in the illustrated embodiment.

[0035] The first auxiliary nozzle 48 has a first outlet opening 52 which opens into a first nozzle slot 54, which is arranged on an end face 56 of the first nozzle body 36 facing away from the annular space 46 and is oriented transversely to the longitudinal axis 16, wherein the slot walls of the first nozzle slot 54 are inclined at an angle of about 8° to the longitudinal axis 16.

[0036] The second auxiliary nozzle 50 has a second outlet opening 58, which opens into a second nozzle slot 60, which is arranged on the end face 56 of the first nozzle body 36 facing away from the annular space 46 and is oriented transversely to the longitudinal axis 16, wherein the slot walls of the second nozzle slot 60 are also inclined at an angle of about 8° to the longitudinal axis 16.

[0037] The second nozzle body 40 has a connection section 62 facing the pipe stub 30, to which a third nozzle inlet channel 64, aligned coaxially to the longitudinal axis 16, connects via a constriction 63. At its end opposite the connection section 62, the second nozzle body 40 forms a main nozzle 66 with a third outlet opening 68, which opens into a third nozzle slot 70 oriented perpendicular to the longitudinal axis 16. The main nozzle 66 is designed as a flat jet nozzle, with which a liquid jet 67, expanding fan-shaped in a jet plane, can be emitted. The opening angle of the liquid jet 67 is approximately 25°.

[0038] As can be seen particularly from Figure 3, the two additional nozzles 48 and 50 are arranged at the same height with respect to the longitudinal axis 16, whereas they are positioned axially offset to the main nozzle 66 in the flow direction 31 of the liquid, i.e. the two additional nozzles 48, 50 protrude beyond the main nozzle 66 with respect to the longitudinal axis 16 in the flow direction 31 of the liquid.

[0039] As can be clearly seen in Figure 6, the fan-shaped liquid jets 49 and 51 emanating from the auxiliary nozzles 48 and 50 are inclined towards the liquid jet 67 emanating from the main nozzle 66. This is due to the nozzle geometries of the auxiliary nozzles 48 and 50 being inclined to the longitudinal axis 16 and the suction effect that the liquid jet 67 emitted from the main nozzle 66 exerts on the liquid jets emanating from the adjacent auxiliary nozzles 48 and 50, acting like a jet pump.By arranging the auxiliary nozzles 48, 50 such that they are axially offset from the main nozzle 66 in the flow direction 31 of the liquid, it is ensured that the liquid jet 67 emanating from the main nozzle 66 has a width in the impact zone of the liquid jets 49, 51 emanating from the auxiliary nozzles 48, 50 that, even taking manufacturing tolerances into account, is at least as large as, and in particular larger than, the width of the liquid jets 49, 51 emanating from the auxiliary nozzles 48, 50. In the impact zone, the liquid jets 49, 51 and 67 emanating from the main nozzle 66 and the auxiliary nozzles 48, 50 merge to form a common liquid jet, the geometry of which is determined by the liquid jet 67 emanating from the main nozzle 66. The liquid jet 67 emanating from the main nozzle 66 thus forms a kind of "guide jet".

[0040] The nozzle assembly 32 is continuously displaceable back and forth in the recess 28 in the axial direction between a first end position shown in Figures 1, 2, and 3 and a second end position shown in Figure 4. For this purpose, the liquid dispensing device 10 has a sleeve 72 that circumferentially surrounds the outlet section of the liquid dispensing device 10 and is formed from two half-shells 74, 76 that are screwed together. On its inner side, the sleeve 72 has an internal thread 78 that interacts with an external thread 80 located on the outside of the extension 26 of the jet tube 14. The nozzle assembly 32 forms a radially outwardly projecting flange 82 in the area protruding from the recess 28, which engages in an annular groove 84 located on the inner side of the sleeve 72. This is particularly evident in Figure 3.By rotating the sleeve 72 about the longitudinal axis 16 relative to the jet tube 14, the sleeve 72 can be moved in the axial direction, this movement being transmitted to the nozzle assembly 32 via the annular groove 84 and the flange 82. The sleeve 72 forms a handle with which the user can continuously move the nozzle assembly 32 back and forth between its first end position and its second end position.

[0041] In the first end position of the nozzle assembly 32, the pipe stub 30 is inserted into the connection section 62 of the second nozzle body 40, being surrounded by an annular gap 65 which is bounded by the pipe stub 30 and the connection section 62. With its end face 67 facing the main nozzle 66, the pipe stub 30, in the first end position of the nozzle assembly 32, rests fluid-tight against the constriction 63, so that the fluid can only flow from the pipe stub 30 to the main nozzle 66 via the third nozzle inlet channel 64, but cannot enter the annular space 46 from the pipe stub 30. In the first end position of the nozzle arrangement 32, only the main nozzle 66 is in flow communication with the inlet channel 18 via the pipe stub 30, but there is no flow connection to the auxiliary nozzles 48 and 50, so that in the first end position of the nozzle arrangement 32 the liquid can only be discharged via the main nozzle 66.

[0042] During the transition of the nozzle arrangement 32 from the first end position to the second end position, the end face 67 of the pipe nozzle 30 assumes an increasing distance to the constriction 63 of the second nozzle body 40, so that liquid can not only reach the main nozzle 66 via the third nozzle inlet channel 64, but liquid can also reach the auxiliary nozzles 48, 50 via the annular gap 65, the annular space 46 and the nozzle inlet channels 42, 44 and consequently be discharged via both the main nozzle 66 and the two auxiliary nozzles 48, 50. The closer the nozzle arrangement 32 gets to the second end position, the more the length of the annular gap 65 decreases and thus also the flow resistance that the annular gap 65 exerts on the liquid, so that the flow of liquid from the pipe nozzle 30 via the annular gap 65, the annular space 46 and the nozzle inlet channels 42, 44 increases continuously.In the second end position of the nozzle arrangement 32, the length of the annular gap 65 is minimal and the flow of liquid from the pipe nozzle 30 to the additional nozzles 48, 50 is maximum.

[0043] If the liquid supplied to the liquid dispensing device 10 is dispensed only via the main nozzle 66, the liquid has a relatively high discharge pressure, which is essentially determined by the delivery rate of the high-pressure cleaner and the size of the third outlet opening 68. If the liquid supplied to the liquid dispensing device 10 is dispensed not only via the main nozzle 66, but also via the two auxiliary nozzles 48 and 50, the liquid has a lower discharge pressure, since the liquid is dispensed not only via the third outlet opening 68, but also via the second outlet opening 58 and the first outlet opening 52. By moving the nozzle arrangement 32, the discharge pressure of the liquid can thus be continuously changed while maintaining a constant delivery rate.This allows the liquid discharge pressure to be adjusted to the surface properties of the area to be cleaned, by applying liquid at a lower discharge pressure to more sensitive areas than to less sensitive areas. The liquid is discharged regardless of the final position of the nozzle assembly 32, with a clearly defined spray pattern in the form of a compact, fan-shaped liquid jet.

Claims

P A T E N T A N S P R Ü C H E 1. Liquid dispensing device for a high-pressure cleaning device comprising a liquid supply part (12) with an inlet channel (18) for pressurized liquid aligned coaxially to a longitudinal axis (16), and further comprising a nozzle arrangement (32) which is continuously displaceable back and forth relative to the liquid supply part (12) between a first end position and a second end position and which has a main nozzle (66) and at least one auxiliary nozzle (48, 50) arranged radially offset to the main nozzle (66) for dispensing the liquid, wherein the liquid jet (49, 51) emanating from the at least one auxiliary nozzle (48, 50) is inclined towards the liquid jet (67) emanating from the main nozzle (66),and wherein in the first end position of the nozzle arrangement (32) the inlet channel (18) is only in flow communication with the main nozzle (66) and, during the transition of the nozzle arrangement (32) from the first end position to the second end position, a flow connection for continuously increasing the flow of liquid from the inlet channel (18) to the at least one auxiliary nozzle (48, 50) can be opened, characterized in that the at least one auxiliary nozzle (48, 50) is arranged axially offset to the main nozzle (66) in the flow direction (31) of the liquid.

2. Liquid dispensing device according to claim 1, characterized in that the nozzle geometry of the at least one auxiliary nozzle (48, 50) is inclined towards the main nozzle (66).

3. Liquid dispensing device according to claim 1 or 2, characterized in that the axial offset of the at least one auxiliary nozzle (48, 50) relative to the main nozzle (66) is at least 5 mm, in particular at least 8 mm.

4. Liquid dispensing device according to claim 1, 2 or 3, characterized in that a nozzle inlet channel (64, 42, 44) is arranged upstream of the main nozzle (66) and upstream of the at least one auxiliary nozzle (48, 50), wherein the nozzle inlet channels (64, 42, 44) are aligned parallel to each other.

5. Liquid dispensing device according to one of the preceding claims, characterized in that the main nozzle (66) and the at least one additional nozzle (48, 50) are designed as flat jet nozzles.

6. Liquid dispensing device according to one of the preceding claims, characterized in that the main nozzle (66) is arranged coaxially to the longitudinal axis (16) of the inlet channel (18) and the nozzle arrangement (32) has two auxiliary nozzles (48, 50) arranged symmetrically to the longitudinal axis (16).

7. Liquid dispensing device according to one of the preceding claims, characterized in that the nozzle arrangement (32) has a first nozzle body (36) which forms the at least one additional nozzle (48, 50) and which has a through-channel (38) aligned coaxially to the longitudinal axis (16) of the inlet channel (18), in which a second nozzle body (40) is fixed which forms the main nozzle (66).

8. Liquid dispensing device according to claim 7, characterized in that the second nozzle body (40) forms an interference fit with the through channel (38) of the first nozzle body (36).

9. Liquid dispensing device according to claim 7 or 8, characterized in that the second nozzle body (40) has a connecting section (62) which in the first end position of the nozzle arrangement- nung (32) is liquid-tight on a connecting element of the liquid supply part (12) which is in flow communication with the inlet channel (18) and interrupts a flow connection of the connecting element with the at least one additional nozzle (48, 50), and which, when the nozzle arrangement (32) transitions from the first end position to the second end position, in combination with the connecting element, limits an annular gap (65) of adjustable width and / or adjustable length for the continuous increase of the flow of liquid from the connecting element to the at least one additional nozzle (48, 50).

10. Liquid dispensing device according to claim 9, characterized in that the connecting section (62) projects out of the first nozzle body (36) against the flow direction (31) of the liquid.

11. Liquid dispensing device according to claim 9 or 10, characterized in that the connecting element is designed as a pipe fitting (30).

12. Liquid dispensing device according to claim 9, 10 or 11, characterized in that the liquid supply part (12) has a jet tube (14) which forms the inlet channel (18) and which has an end region (24) which forms a cup-shaped recess (28) into which the inlet channel (18) opens, wherein the connecting member is attached to the inlet channel (18) and projects into the recess (28), and wherein the nozzle arrangement (32) is immersed in the recess (28) and is held axially displaceable in the recess (28).

13. Liquid dispensing device according to claim 12, characterized in that the liquid dispensing device (10) has a sleeve (72) which is rotatably and axially displaceably mounted on the end region (20) of the jet tube (14) via a thread (78, 80) and which is rotatably and axially immovably connected to the nozzle arrangement (32).

14. Liquid dispensing device according to claim 13, characterized in that the sleeve (72) has an annular groove (84) on the inside into which a flange (82) of the nozzle arrangement (32) is immersed.

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