DRIVE NOZZLE AND SURFACE CLEANING HEAD WITH ONE DRIVE NOZZLE

Description

[0001] The invention relates to a drive nozzle for a jet pump of a surface cleaning head, wherein pressurized cleaning fluid can be applied to a surface to be cleaned by means of the surface cleaning head and subsequently sucked up by means of the jet pump, wherein the drive nozzle has a nozzle body which can be connected to a supply line for pressurized cleaning fluid and which has a nozzle outlet opening for delivering a cleaning fluid jet.

[0002] Furthermore, the invention relates to a surface cleaning head for cleaning a surface with such a drive nozzle.

[0003] US 4,260,110 A discloses a spray nozzle for dispensing a pressurized liquid in the form of a spray mist. The spray nozzle comprises a housing with an ejection chamber having a nozzle outlet and, as a first turbulence stage, an annular chamber arranged coaxially to a central axis of the nozzle outlet. Supply channels lead from the annular chamber approximately tangentially to the circumference of the ejection chamber. Furthermore, the interior space comprises at least one additional turbulence stage and, between two successive turbulence stages, at least one obstacle that breaks up the liquid flowing from the upstream to the downstream turbulence stage and deflects the liquid from a flow plane through the annular chamber toward the side of the nozzle outlet by an angle of up to 90°.

[0004] DE 20 2016 103 825 U1 discloses a swirl body, particularly for use in a conical nozzle, for example, a full-cone nozzle or a hollow-cone nozzle, for imparting rotation to a fluid flowing through it. The swirl body has a cylindrical base section with a cylindrical outer surface. Adjoining the base section is a conical end section that defines a conical end face. At least one swirl channel is formed in the cylindrical outer surface, extending obliquely to a central longitudinal axis of the swirl body, which is open at one end and opens into the conical end face.

[0005] EP 2 547 463 B1 discloses a surface cleaning head with which a surface can be cleaned by exposing the surface to pressurized cleaning fluid, which can be supplied to the surface cleaning head by a high-pressure cleaning device. The surface cleaning head has a housing surrounding a cleaning chamber in which at least one cleaning nozzle is arranged. The cleaning fluid can be sprayed onto the surface to be cleaned by means of the at least one cleaning nozzle.

[0006] In addition to the at least one cleaning nozzle, the surface cleaning head known from EP 2 547 463 B1 has a jet pump that operates according to the principle of a Venturi nozzle. The jet pump comprises a drive nozzle that can also be supplied with pressurized cleaning fluid. The drive nozzle is arranged in a suction nozzle, and by releasing pressurized cleaning fluid via the drive nozzle, a suction flow can be generated within the suction nozzle. The suction nozzle is in flow communication with the cleaning chamber of the surface cleaning head, so that the cleaning fluid applied to the surface can be sucked up together with the cleaned-off dirt under the effect of the suction flow. An outlet line can be connected to the free end of the suction nozzle, through which the sucked-up cleaning fluid can be discharged together with the cleaned-off dirt.

[0007] To achieve effective suction with the nozzle, it is necessary to supply the nozzle with pressurized cleaning fluid, which is discharged from the nozzle in the form of a conical jet. When using the nozzle with a surface cleaning head, it is desirable to keep the consumption of cleaning fluid required for suction as low as possible, so that the largest possible proportion of the cleaning fluid supplied to the surface cleaning head is available for spraying the surface.

[0008] EP 2 547 463 B1 discloses a propulsion nozzle according to the preamble of claim 1.

[0009] The object of the present invention is therefore to further develop a drive nozzle of the type mentioned at the outset in such a way that it enables good suction with less consumption of cleaning fluid.

[0010] This object is achieved according to the invention in a propulsion nozzle of the generic type in that the nozzle body has an interior space with a conical end section, at the tip of which the nozzle outlet opening is arranged, wherein a nozzle insert is arranged in the conical end section, which has a cylindrical base, to which a truncated cone-shaped extension adjoins in the direction of the nozzle outlet opening, the outer surface of which bears positively against an inner wall of the conical end section, wherein the nozzle insert has a through-channel aligned with the nozzle outlet opening and several swirl channels formed in the outer surface of the extension, wherein the through-channel opens into a swirl chamber located in the conical end section immediately upstream of the nozzle outlet opening and the swirl channels open into the swirl chamber laterally offset from the through-channel,where the flow cross-section of the nozzle outlet opening transmits a maximum of one third of the sum of the flow cross-sections of the through-channel and the swirl channels.

[0011] The propulsion nozzle according to the invention comprises a nozzle body whose interior has a conical end section. At the tip of the conical end section, the nozzle body has a nozzle outlet opening through which pressurized cleaning fluid can be discharged from the propulsion nozzle. A nozzle insert is arranged in the conical end section, which has a cylindrical base and a frustoconical extension adjoining it in the direction of the nozzle outlet opening. A peripheral surface of the frustoconical extension bears positively against an inner wall of the conical end section. The nozzle insert has a through-channel aligned with the nozzle outlet opening, as well as several swirl channels formed into the peripheral surface of the extension. Between the nozzle insert and the nozzle outlet opening, the conical end section of the interior of the nozzle body forms a swirl chamber.The through-channel of the nozzle insert extends collinearly to a central axis of the nozzle insert and opens centrally into the swirl chamber. The swirl channels open into the swirl chamber laterally offset from the through-channel. Part of the cleaning fluid supplied to the drive nozzle enters the swirl chamber via the central through-channel, and another part of the cleaning fluid enters the swirl chamber via the swirl channels. From the swirl chamber, the cleaning fluid is discharged outwards via the nozzle outlet opening in the form of a full-cone jet. It has been shown that particularly good suction can be achieved using the drive nozzle if the flow cross-section of the nozzle outlet opening is a maximum of one-third of the sum of the flow cross-sections of the through-channel and the swirl channels.

[0012] Pressurized cleaning fluid can be supplied to the swirl chamber through relatively large flow cross-sections, and the cleaning fluid can be discharged from the swirl chamber through a relatively small flow cross-section. The cleaning fluid is discharged from the swirl chamber through the nozzle outlet. The flow cross-section of the nozzle outlet is a maximum of one-third of the sum of the flow cross-sections of the through-channel and the swirl channels. This has been shown to achieve particularly effective extraction with relatively low consumption of cleaning fluid.

[0013] In an advantageous embodiment of the drive nozzle according to the invention, the flow cross-section of the nozzle outlet opening is a maximum of one fifth of the sum of the flow cross-sections of the through-channel and the swirl channels.

[0014] Preferably, the flow cross-section of the nozzle outlet opening is at most as large as the flow cross-section of the through-channel and is at most half the sum of the flow cross-sections of the swirl channels.

[0015] It is advantageous if the flow cross-section of the nozzle outlet opening is smaller than the flow cross-section of the through-channel and also smaller than the flow cross-section of each individual swirl channel.

[0016] It is advantageous if the swirl channels are designed to be straight. This helps keep manufacturing costs low.

[0017] It is particularly advantageous if the swirl channels are evenly distributed around the circumference of the extension and the longitudinal axes of the swirl channels are aligned skew to the longitudinal axis of the through-channel. The skew of the longitudinal axes of the swirl channels relative to the longitudinal axis of the through-channel makes it easy to offset the openings of the swirl channels relative to the longitudinal axis of the through-channel, which is aligned with the nozzle outlet opening. This allows the cleaning fluid to be discharged from the drive nozzle in the form of a full cone jet, enabling particularly effective suction.

[0018] The nozzle insert can, for example, have 2, 3, 4, 5 or 6 swirl channels.

[0019] In a preferred embodiment of the drive nozzle according to the invention, its nozzle characteristic is 0.18 l / min to 0.35 l / min, in particular 0.18 l / min to 0.28 l / min, at a reference pressure of 1 bar. The nozzle characteristic is defined here as the flow rate at a specific reference pressure, specifically the flow rate of the cleaning fluid flowing through the drive nozzle at a reference pressure of 1 bar is preferably 0.18 l / min to 0.35 l / min, in particular 0.18 l / min to 0.28 l / min.

[0020] To prevent dirt particles carried along by the cleaning fluid from clogging the propulsion nozzle over time, it is advantageous for the propulsion nozzle to have a filter device located upstream of the nozzle insert in the interior of the nozzle body. The filter device is thus integrated into the propulsion nozzle.

[0021] In a preferred embodiment of the invention, the filter device has a cup-shaped, bell-shaped, or convexly curved filter surface. This allows the installation space required for the filter device to be reduced without the cleaning fluid suffering significant flow losses when flowing through the filter device.

[0022] The filter device preferably has a sieve. The mesh size of the sieve is preferably 0.6 mm, in particular a maximum of 0.3 mm.

[0023] The sieve is preferably made of metal, in particular steel, and / or a plastic material.

[0024] The diameter of the passage channel of the nozzle inlet of the drive nozzle is preferably about 0.8 mm.

[0025] In an advantageous embodiment, the diameter of the nozzle outlet opening of the drive nozzle is approximately 0.7 mm.

[0026] The flow cross-section of the swirl channels is preferably about 0.6 mm 2< to about 0.7 mm 2< .

[0027] As mentioned at the outset, the invention also relates to a surface cleaning head for cleaning a surface, wherein the surface cleaning head has a drive nozzle of the type explained above. The surface cleaning head comprises a housing having a cleaning chamber surrounded by a peripheral wall and open downwards in a horizontal position of use of the surface cleaning head, in which at least one cleaning nozzle is held, which can be subjected to pressurized cleaning fluid and is used to apply cleaning fluid to the surface to be cleaned. The surface cleaning head also comprises a jet pump for sucking away cleaning fluid applied to the surface, wherein the jet pump has a suction nozzle which is in flow connection with the cleaning chamber and which adjoins the peripheral wall and to which an outlet line can be connected, wherein a drive nozzle of the type explained above is arranged in the suction nozzle.

[0028] Pressurized cleaning fluid from a high-pressure cleaning device can be supplied to the surface cleaning head. The surface cleaning head has at least one cleaning nozzle that can be pressurized with cleaning fluid to apply the cleaning fluid to the surface to be cleaned. The applied fluid can then be vacuumed from the surface. For this purpose, the surface cleaning head has a jet pump with a suction nozzle in which a drive nozzle of the type described above is arranged. As already mentioned, the drive nozzle enables an effective suction flow to be generated within the suction nozzle, whereby the required consumption of cleaning fluid can be kept to a minimum.

[0029] The jet pump of the surface cleaning head therefore has very good suction efficiency, so that a large part of the cleaning fluid provided to the surface cleaning head can be used to clean the surface to be cleaned.

[0030] The surface cleaning head preferably has at least one spray arm, which is mounted in the cleaning chamber so as to be freely rotatable about a rotational axis and to which a cleaning nozzle is attached. When cleaning fluid is dispensed, the cleaning nozzle generates a fluid jet directed diagonally downward toward the surface to be cleaned. This jet experiences a recoil, under the effect of which the spray arm is rotated about the rotational axis.

[0031] In an advantageous embodiment of the surface cleaning head according to the invention, two diametrically opposed spray arms are used, each of which has a cleaning nozzle arranged thereon, wherein the cleaning nozzles can be simultaneously supplied with pressurized cleaning fluid.

[0032] It is advantageous if the surface cleaning head has an inlet line for supplying pressurized cleaning fluid, wherein a fluid distribution device is connected to the inlet line and is connected to the drive nozzle via a first supply line and to the at least one cleaning nozzle via a second supply line, wherein an end region of the first supply line facing away from the fluid distribution device projects into the suction nozzle and carries the drive nozzle. Such a design makes it possible to position the drive nozzle within the suction nozzle without it having to be supported on the suction nozzle by support elements. Rather, with such a design, the drive nozzle is completely surrounded in the circumferential direction by an annular space, through which cleaning fluid applied to the surface to be cleaned can flow into the suction nozzle together with the removed dirt.The suction flow is therefore subject to only minimal flow losses in the area of the propulsion nozzle.

[0033] It is advantageous if the nozzle body of the drive nozzle is detachably and fluid-tightly held at the end region of the first supply line projecting into the suction nozzle, with the nozzle insert of the drive nozzle abutting one or more support surfaces of the first supply line. With such a configuration, the nozzle insert abuts with its base against one or more support surfaces of the first supply line, and with the lateral surface of the frustoconical extension abuts the inner wall of the conical end section of the interior of the nozzle body. This allows the nozzle insert to be clamped in the interior of the nozzle body between the inner wall of the end section of the interior and at least one support surface of the first supply line, thereby mechanically securing it.

[0034] It is particularly advantageous if the nozzle body is screwed to the end portion of the first supply line that extends into the suction nozzle. With such a configuration, the nozzle body can be screwed onto the end portion of the first supply line, enclosing the nozzle insert, which is supported on the one hand against the inner wall of the nozzle body and on the other hand against one or more support surfaces of the first supply line.

[0035] It is advantageous if a sealing element is arranged between the nozzle body and the end portion of the first supply line that extends into the suction nozzle. For example, a sealing ring positioned in an annular groove that circumferentially surrounds the end portion of the first supply line can be used as the sealing element.

[0036] The first supply line establishes a flow connection between the fluid distribution device and the drive nozzle. It is advantageous if the first supply line is detachably connected to the fluid distribution device. This allows for easy installation of the first supply line and also makes it possible to remove the first supply line, together with the attached drive nozzle, from the surface cleaning head. The drive nozzle can then be removed from the first supply line, for example, for cleaning purposes or to replace the nozzle insert of the drive nozzle.

[0037] The propellant nozzle is arranged in the suction port of the jet pump of the surface cleaning device. The suction port preferably forms an inlet channel, which is connected to a mixing channel that tapers conically in the direction of flow of the cleaning fluid.

[0038] The mixing channel is advantageously followed by a collecting channel, via which the mixing channel is connected to a diffuser.

[0039] The catch channel is preferably cylindrical in shape.

[0040] The diameter of the collecting channel is preferably at least 20 mm, in particular 20 mm to 50 mm, for example 23 mm.

[0041] The distance between the drive nozzle and the collecting channel is preferably a maximum of 40 mm.

[0042] It is advantageous if the full cone jet emitted by the drive nozzle expands continuously within the mixing channel over the entire length of the mixing channel.

[0043] The following description of preferred embodiments of the invention serves to explain it in more detail in conjunction with the drawings. They show: Figure 1: a perspective view of a surface cleaning head to which an outlet line is connected; Figure 2: a longitudinal sectional view of the surface cleaning head from Figure 1 with connected outlet line; Figure 3: a perspective view of a first supply line of the surface cleaning head, which carries a drive nozzle; Figure 4: a perspective view of the first supply line from Figure 3 , with a nozzle body of the propulsion nozzle hidden; Figure 5: an enlarged view of detail Z from Figure 2 ; Figure 6: a perspective view of a nozzle insert of the propulsion nozzle.

[0044] The drawing schematically illustrates an advantageous embodiment of a surface cleaning head according to the invention and an advantageous embodiment of a drive nozzle according to the invention. The surface cleaning head is shown in a horizontal position of use and is designated overall by the reference numeral 10. As explained in more detail below, with the aid of the surface cleaning head 10, a surface 12 to be cleaned can be subjected to pressurized cleaning fluid in order to clean the surface 12. The applied cleaning fluid can then be sucked up together with the removed dirt by means of a jet pump 44 of the surface cleaning head and discharged via an outlet line 14. The jet pump 44 has an advantageous embodiment of a drive nozzle according to the invention, which is designated overall by the reference numeral 56.

[0045] The surface cleaning head 10 has a hood-like housing 16 on which three support wheels 18, 20, 22 are rotatably mounted. With the help of the support wheels 18, 20, 22, the housing 16 can be supported on the surface 12 to be cleaned and moved along the surface 12.

[0046] The housing 16 has an intermediate wall 24, to which a circular-cylindrical peripheral wall 26 adjoins downwards in the direction of the surface 12 to be cleaned. The peripheral wall 26 surrounds a cleaning chamber 28 and carries, on its edge facing the surface 12 to be cleaned, a circumferential splash guard element 30, which in the illustrated embodiment is designed in the form of a bristle strip.

[0047] Above the partition wall 24, the housing 16 defines a distribution chamber 32, which accommodates a liquid distribution device 34. An inlet line 36 extends into the distribution chamber 32. This inlet line is connected to the liquid distribution device 34 and carries, at its end remote from the liquid distribution device 34, a connecting element 38 to which, for example, a spray lance of a high-pressure cleaning device can be connected. This spray lance is known per se and therefore not shown in the drawing for clarity. A cleaning fluid, preferably water, can be pressurized in a known manner by means of the high-pressure cleaning device and can be supplied to the surface cleaning head via the spray lance.

[0048] The pressure of the cleaning fluid can be, for example, 50 bar to 180 bar, in particular 70 bar to 120 bar.

[0049] The flow rate of the cleaning fluid supplied to the surface cleaning head 10 is preferably about 200 l / h to about 700 l / h.

[0050] The peripheral wall 26 has a lateral opening 40, to which a suction nozzle 42 of a jet pump 44, which is explained in more detail below, is connected.

[0051] The suction nozzle 42 forms an inlet channel 46 directly adjacent to the lateral opening 40. A cylindrical collecting channel 50 is connected to the inlet channel via a mixing channel 48 that tapers conically in the direction away from the inlet channel 46. This mixing channel 50, in turn, is connected to a diffuser 52. The collecting channel 50 is cylindrical, and the diffuser 52 widens conically in the direction away from the collecting channel 50. The outlet line 14 can be connected to the diffuser 52. If necessary, the outlet line 14 can be separated from the diffuser 52.

[0052] The cleaning fluid supplied to the surface cleaning head 10 via the inlet line 36 is divided by the fluid distribution device 34, wherein a first portion of the cleaning fluid is supplied via a first supply line 54 to a drive nozzle 56 of the jet pump 44 arranged in the inlet channel 46 of the suction nozzle 42, and wherein a second portion of the cleaning fluid is supplied via a second supply line 58 to a cleaning nozzle arrangement 60 which is arranged in the cleaning chamber 28.

[0053] The cleaning nozzle arrangement 60 has a first cleaning nozzle 62 and a second cleaning nozzle 64. The first cleaning nozzle 62 is arranged on a first spray arm 66, and the second cleaning nozzle 64 is arranged on a second spray arm 68. The two spray arms 66, 68 are diametrically opposed to one another and are mounted on the second supply line 58 so as to be freely rotatable about an axis of rotation 70 oriented perpendicular to the surface 12 to be cleaned. Pressurized cleaning fluid can be sprayed onto the surface 12 to be cleaned via the first cleaning nozzle 62 and the second cleaning nozzle 64. The cleaning nozzles 62, 64 experience a recoil, under the effect of which the spray arms 66, 68 are set in rotation about the axis of rotation 70.

[0054] The first supply line 54 is detachably connectable to the liquid distribution device 34 by means of a connecting element 72, which is arranged at the end of the first supply line 54 facing the liquid distribution device 34. Additionally, a holding arm 74 is formed approximately centrally on the first supply line 54, which arm can be used to detachably hold the first supply line 54 to the partition wall 24.

[0055] The first supply line 54 extends into the suction nozzle 42 with an end portion 76 facing away from the liquid distribution device 34. The drive nozzle 56 is releasably held at this end portion 76.

[0056] The drive nozzle 56 is designed as a full-cone spray nozzle. As can be seen in particular from Figure 5As is clear, the drive nozzle 56 has a nozzle body 78 which is designed in the manner of a cap or hood and whose interior 80 accommodates the end region 76 of the first supply line 54.

[0057] The nozzle body 78 has an internal thread 82, which can be releasably screwed to a complementary external thread 84 of the end portion 76. To ensure a fluid-tight connection between the end portion 76 and the nozzle body 78, a sealing element in the form of a sealing ring 86 is used, which is arranged in an annular groove 88 of the end portion 76.

[0058] The interior space 80 of the nozzle body 78 has a conical end section 90, at the tip of which a nozzle outlet opening 92 is connected. A nozzle insert 94 is arranged in the conical end section 90, which has a cylindrical base 96, to which a frustoconical extension 98 is connected in the direction of the nozzle outlet opening 92.

[0059] The nozzle insert 94 is penetrated by a through-channel 100 aligned with the nozzle outlet opening 92. The nozzle outlet opening 92 and the through-channel 100 are aligned collinearly with a central axis 102 of the drive nozzle 56. The flow cross-section of the nozzle outlet opening 92 is smaller than the flow cross-section of the through-channel 100.

[0060] The frustoconical extension 98 of the nozzle insert 94 has a circumferential surface 104 that bears positively against the inner wall 106 of the conical end section 90. Four identical, linear swirl channels 108 are formed into the circumferential surface 104 and are evenly distributed around the circumference of the frustoconical extension 98. The longitudinal axes 109 of the swirl channels are skewed relative to the longitudinal axis 101 of the through-channel 100. The flow cross-sections of the swirl channels 108 are larger than the flow cross-section of the nozzle outlet opening 92. Preferably, the flow cross-sections of the swirl channels 108 are also larger than the flow cross-section of the through-channel 100.

[0061] In the preferred embodiment shown, the swirl channels 108 have a U-shaped cross section.

[0062] The nozzle outlet opening 92 has a circular cross-section, and the through-channel 100 also has a circular cross-section. The diameter of the through-channel 100 can be, for example, 0.8 mm, and the diameter of the nozzle outlet opening can be, for example, 0.7 mm.

[0063] Between the nozzle insert 94 and the nozzle outlet opening 92, the conical end section 90 forms a conical swirl chamber 110 into which both the through-channel 100 and the swirl channels 108 open.

[0064] The through-channel 100, which is aligned collinearly with the central axis 102 of the drive nozzle 56, opens centrally into the swirl chamber 110, whereas the swirl channels 108 open into the swirl chamber 110 laterally offset from the through-channel 100, this is particularly evident from Figure 6 clearly.

[0065] The end region 76 of the first supply line 54 has, at its free end, three holding fingers 112, 113, 114 arranged at equal angular spacing from one another and facing the conical end section 90 of the interior space 80. A filter device in the form of a sieve 116 is arranged between the holding fingers 112, 113, 114 and is positioned directly in front of the nozzle insert 94. The nozzle insert 94 is supported on its rear side facing away from the nozzle outlet opening 92 on support surfaces 118 of the holding fingers 112, 113, 114. The nozzle insert 94 is clamped between the support surfaces 118 and the inner wall 106 of the conical end section 90 and holds the sieve 116 in position between the holding fingers 112, 113, 114.

[0066] The sieve 116 is preferably made of metal, in particular steel, and / or a plastic material. The mesh size of the sieve 116 is a maximum of 0.6 mm, preferably a maximum of 0.3 mm.

[0067] The sieve 116 forms a filter or sieve surface 120 through which pressurized cleaning fluid can flow. Preferably, the filter surface 120 is cup-shaped, bell-shaped, or convexly curved.

[0068] As already mentioned, pressurized cleaning fluid can be applied to the surface 12 to be cleaned by means of the cleaning nozzle arrangement 60. The applied fluid can then be sucked up together with the removed dirt by means of the jet pump 44 and discharged via the outlet line 14. For this purpose, pressurized cleaning fluid can be supplied to the drive nozzle 56 via the first supply line 54, with a portion of the supplied cleaning fluid flowing through the through-channel 100 and the remaining portion of the supplied cleaning fluid flowing through the swirl channels 108. In this way, the cleaning fluid reaches the swirl chamber 110, from which the cleaning fluid is discharged via the nozzle outlet opening 92 in the form of a full cone jet.

[0069] The flow cross-section of the nozzle outlet opening 92 is smaller than the flow cross-section of the through-channel 100 and also smaller than the flow cross-section of the individual swirl channels 108. The flow cross-section of the nozzle outlet opening 92 is a maximum of one-third of the sum of the flow cross-sections of the through-channel 100 and the swirl channels 108.

[0070] The flow rate of the cleaning fluid supplied to the drive nozzle 56 via the first supply line 54 is lower than the flow rate of the cleaning fluid supplied to the at least one cleaning nozzle 62, 64 via the second supply line 58. In the illustrated embodiment, the flow rate of the cleaning fluid supplied to the drive nozzle 56 via the first supply line 54 is a maximum of 50% of the flow rate of the cleaning fluid supplied to the cleaning nozzles 62, 64 via the second supply line 58.

[0071] As already mentioned, pressurized cleaning fluid is discharged from the drive nozzle 56 in the form of a full-cone jet. The drive nozzle 56 thus forms a full-cone spray nozzle. The nozzle characteristic of the drive nozzle 56 is 0.18 l / min to 0.35 l / min, in particular 0.18 l / min to 0.28 l / min, at a reference pressure of 1 bar.

[0072] The jet pump 44 has high suction efficiency, meaning it enables the creation of a strong suction flow with relatively low consumption of pressurized cleaning fluid. Approximately one-third of the cleaning fluid supplied to the surface cleaning head 10 is used to generate the suction flow, and approximately two-thirds of the cleaning fluid supplied to the surface cleaning head 10 is sprayed onto the surface 12.

Claims

1. Motive nozzle for a jet pump (44) of a surface cleaning head (10), wherein by means of the surface cleaning head (10) pressurized cleaning liquid is able to be applied to a surface (12) to be cleaned and subsequently be sucked up, wherein the motive nozzle (56) comprises a nozzle body (78), which is connectable to a supply conduit (54) for pressurized cleaning liquid and which comprises a nozzle outlet opening (92) for delivering a cleaning liquid jet, characterized in that the nozzle body (78) comprises a inner space (80) with a conical end portion (90), at the tip of which the nozzle outlet opening (92) is arranged, wherein arranged in the conical end portion (90) is a nozzle insert (94), which comprises a cylindrical base (96) that is adjoined in the direction of the nozzle outlet opening (92) by a truncated cone-shaped extension (98), the outer surface (104) of which abuts against an inside wall (106) of the conical end portion (90) in a positive-locking manner, wherein the nozzle insert (94) comprises a through-channel (100) oriented in alignment with the nozzle outlet opening (92) and comprises a plurality of swirl channels (108) molded into the outer surface (104) of the extension (98), wherein the through-channel (100) opens into a swirl chamber (110) arranged directly upstream of the nozzle outlet opening (92) in the conical end portion (90) and the swirl channels (108) open into the swirl chamber (110) laterally offset from the through-channel (100), and wherein the flow cross section of the nozzle outlet opening (92) amounts to at most one third of the sum of the flow cross sections of the through-channel (100) and the swirl channels (108).

2. Motive nozzle in accordance with Claim 1, characterized in that the flow cross section of the nozzle outlet opening (92) is at most as great as the flow cross section of the through-channel (100) and amounts to at most half the sum of the flow cross sections of the swirl channels (108).

3. Motive nozzle in accordance with Claim 1 or 2, characterized in that the flow cross section of the nozzle outlet opening (92) is smaller than the flow cross section of the through-channel (100) and smaller than the flow cross section of each individual swirl channel (108).

4. Motive nozzle in accordance with Claim 1, 2, or 3, characterized in that the swirl channels (108) are of rectilinear configuration.

5. Motive nozzle in accordance with Claim 4, characterized in that the swirl channels (108) are arranged uniformly distributed over the circumference of the extension (98) and the longitudinal axes (109) of the swirl channels (108) are skew with respect to the longitudinal axis (101) of the through-channel (100).

6. Motive nozzle in accordance with any one of the preceding Claims, characterized in that the nozzle characteristic of the motive nozzle is 0.18 I / min to 0.35 I / min at a reference pressure of 1 bar.

7. Motive nozzle in accordance with any one of the preceding Claims, characterized in that the motive nozzle (56) comprises a filter device, which is arranged upstream of the nozzle insert (94) in the inner space (90) of the nozzle body (78).

8. Motive nozzle in accordance with Claim 7, characterized in that the filter device comprises a cup-shaped, bell-shaped, or convexly curved filter surface (120).

9. Motive nozzle in accordance with Claim 7 or 8, characterized in that the filter device comprises a sieve (116).

10. Surface cleaning head for cleaning a surface (12), comprising a housing (16), which comprises a cleaning space (28) that is surrounded by a circumferential wall (26) and is open toward the bottom in a horizontal use position of the surface cleaning head (10), in which cleaning space at least one cleaning nozzle (62, 64) that is able to be acted upon with pressurized cleaning liquid is held for applying cleaning liquid to the surface (12) to be cleaned, and further comprising a jet pump (44) for suctioning off cleaning liquid applied to the surface (12), wherein the jet pump (44) comprises a suction connection piece (42) in flow connection with the cleaning space (28), which suction connection piece adjoins the peripheral wall (26) and to which an outlet conduit (14) is connectable, wherein a motive nozzle (56) in accordance with any one of the preceding Claims is arranged in the suction connection piece (42).

11. Surface cleaning head in accordance with Claim 10, characterized in that the surface cleaning head (10) comprises an inlet conduit (36) for supplying pressurized cleaning liquid, wherein the inlet conduit (36) is adjoined by a liquid distribution device (34), which is connected to the motive nozzle (56) by way of a first supply conduit (54) and to the at least one cleaning nozzle (62, 64) by way of a second supply conduit (58), wherein an end region (76) of the first supply conduit (54) remote from the liquid distribution device (34) projects into the suction connection piece (42) and bears the motive nozzle (56).

12. Surface cleaning head in accordance with Claim 11, characterized in that the nozzle body (78) of the motive nozzle (56) is held on the end region (76) of the first supply conduit (54) in a releasable and liquidtight manner, wherein the nozzle insert (94) of the motive nozzle (56) abuts against one or more support surfaces (118) of the first supply conduit (54).

13. Surface cleaning head in accordance with Claim 12, characterized in that the nozzle body (78) is screwed to the end region (76) of the first supply conduit (54).