High-pressure cleaner with a pressure adjustment device

Description

[0001] The invention relates to a high-pressure cleaner with a pressure adjustment device according to claim 1.

[0002] High-pressure cleaners are used to pressurize a cleaning fluid, especially water, and then expel it through a spray nozzle, such as a lance with a nozzle head, to clean objects with the jet of fluid. To generate the pressure, the high-pressure cleaner includes a pump connected at its inlet to a suction line, also called a low-pressure line, and at its outlet to a pressure line, also called a high-pressure line. Fluid is supplied to the pump via the suction line. The pump pressurizes the fluid, which is then transferred from the pump outlet into the pressure line. When the spray nozzle is open, the fluid flows out of the nozzle under high pressure. Document US 2016 / 288148 A1 discloses a spray gun for a high-pressure cleaner. Document WO 2006 / 053414 Al discloses a rotary slide valve for industrial applications.

[0003] High-pressure cleaners are known to allow for pressure adjustment in the pressure line to regulate the flow rate at the spray nozzle. One way to regulate the flow rate is to include a bypass between the pressure line and the suction line. This bypass has an adjustable minimum flow cross-section. When the minimum flow cross-section is increased, there is a greater flow loss to the suction line in the pressure line, which reduces the pressure in the pressure line and thus also the flow rate when the spray nozzle is open. When the bypass is closed, there is no flow loss. The pressure line then operates at maximum pressure, allowing for maximum flow rate when the spray nozzle is open.

[0004] The bypass incorporates a valve to adjust the minimum flow cross-section. This valve comprises a valve seat and a valve body that interacts with the valve seat. When the valve is closed, the valve body rests on the valve seat, thus closing the bypass between the pressure line and the suction line. To open the valve, the valve body is lifted from the valve seat, thereby releasing a minimum flow cross-section. This lifting of the valve body from the valve seat occurs through a translational movement. The valve is designed such that the minimum flow cross-section increases with increasing distance between the valve body and the valve seat, causing a drop in pressure in the pressure line. Such systems are extremely complex and require high manufacturing precision. Consequently, they are quite expensive.Setting a specific pressure in the pressure line has also proven to be extremely difficult.

[0005] The invention is based on the objective of providing a high-pressure cleaner with a pressure adjustment device, wherein the pressure adjustment device has a simple design and at the same time enables a robust adjustment of the pressure in a pressure line of the high-pressure cleaner.

[0006] The invention is solved by a high-pressure cleaner having the features of claim 1.

[0007] The pressure adjusting device for a high-pressure cleaner comprises a valve housing with a valve seat, at least one inlet for supplying a liquid, at least one outlet for discharging the liquid, and a valve body with a longitudinal center axis, wherein the valve body is pivotably mounted in the valve housing about its longitudinal center axis, wherein the valve body has a valve element associated with the valve seat circumferentially with respect to its longitudinal center axis, wherein in a closed position of the valve body the valve seat is closed by the valve element and the flow connection between the inlet and the outlet is interrupted, wherein the valve body is pivotable about its longitudinal center axis from the closed position to an open position, wherein in the open position a flow connection between the inlet and the outlet with a minimum flow cross-section is provided.wherein the minimum flow cross-section is formed by a flow unit formed on the valve element and the valve element is designed such that the size of the minimum flow cross-section is adjustable as a function of a swivel angle of the valve body about its longitudinal central axis.

[0008] The valve of the pressure adjustment device is opened and closed by pivoting the valve element. The flow unit on the valve element is designed such that the size of the minimum flow cross-section is adjustable depending on the pivot angle of the valve body. With conventional, translationally movable valve bodies, even a small movement of the valve body leads to a large change in the minimum flow cross-section. Thus, the pressure adjustment behavior is extremely sensitive and susceptible to manufacturing tolerances. The flow unit on the valve element, which is arranged on the circumference of the valve body, allows the minimum flow cross-section to be adjusted depending on the pivot angle of the valve body. The pressure adjustment behavior is less sensitive and insensitive to manufacturing tolerances of the valve body.Furthermore, the rotary motion principle of the valve body is mechanically easier to implement than the translational displacement of a valve body.

[0009] It is advantageously provided that the swivel angle is in a range of 0° to 360°, particularly from 0° to 270°, preferably from 0° to 180°, and more preferably from 0° to 90°. If the swivel angle is chosen to be too large, this can lead to an excessively long pressure adjustment time. Therefore, the swivel angle for setting the minimum flow cross-section is chosen to be sufficiently small so that the pressure can be adjusted quickly across the entire pressure range. The selected swivel angle allows for simple and quick manual adjustment of the valve body, since the angle to be swiveled by the operator can be achieved with a single hand movement. Thus, it can be advantageously provided that the pressure adjustment device includes an actuating unit acting on the first end of the valve body for swiveling the valve body. Particularly advantageously, the actuating unit includes a detent for stepwise swiveling of the valve body.The detent mechanism has several stages, preferably three. It may also be advantageous to provide more than three stages. The actuating unit has a first pivoting direction and a second pivoting direction opposite to the first. The minimum flow cross-section of the flow unit increases when the valve body pivots from the closed position in the first pivoting direction. When the valve body pivots back in the second pivoting direction, the minimum flow cross-section in the flow unit decreases. Furthermore, the small pivot angle allows for rapid adjustment via an electric motor. Preferably, the actuating unit comprises a servo motor or a stepper motor for pivoting the valve body. Other motors may also be suitable. This enables automatic adjustment of the minimum flow cross-section.

[0010] It is advantageously provided that the flow unit is designed as a cam on a circumferential section of the valve element. Accordingly, a flow connection is established via the cam between the inlet and outlet of the pressure adjusting device. To adjust the minimum flow cross-section, the valve body with the cam must be positioned relative to the valve seat. The cam is preferably designed such that the pressure at the inlet is continuously adjustable. If the valve element with the cam is pivoted from the closed position in the first direction, the minimum flow cross-section increases, thereby reducing the pressure at the inlet. If the valve element with the cam is pivoted in the second direction towards the closed position, the minimum flow cross-section decreases, thereby increasing the pressure at the inlet.

[0011] As the length of the cam profile increases, i.e., the angular distance between its two ends, the resolution for adjusting the minimum flow cross-section increases. Furthermore, the sensitivity of the pressure adjustment device decreases when setting the minimum flow cross-section and the associated pressure at the pressure adjustment device's inlet. This makes the pressure adjustment device less sensitive to high manufacturing tolerances or inaccurate adjustment of the swivel angle. With a decreasing cam profile length, a mechanically faster adjustment of the minimum flow cross-section and the associated pressure at the inlet is possible. Based on these findings, the following values ​​for the cam profile were determined. The cam profile of the valve element extends from its first end to its second end over an angular distance measured with respect to the longitudinal center axis, with this angular distance being at least 30°.Preferably, the angular distance is at least 60°, in particular at least 90°, preferably approximately 120°. Advantageously, the angular distance between the first end and the second end of the cam is at most 270°, preferably at most 180°, in particular at most 150°.

[0012] The minimum angular distance between the ends of the cam ensures that the minimum flow cross-section, and therefore the pressure at the inlet, has a high adjustment resolution. The maximum angular distance between the ends of the cam is chosen such that the resulting adjustment travel is sufficiently short to allow for rapid adjustment of the minimum flow cross-section.

[0013] It is advantageously designed that the valve mechanism is such that the size of the minimum flow cross-section can be adjusted, at least partially linearly, depending on the swivel angle of the valve body around its longitudinal center axis. This makes pressure adjustment very intuitive for the operator.

[0014] It is preferably provided that the valve element has a transverse plane oriented perpendicular to the longitudinal center axis, wherein the transverse plane intersects the valve body with the cam in a cross-sectional area, the cross-sectional area being bounded at the cam by several chords. The chords correspond to the base of the cam. This design of the cam allows the valve element and cam to be manufactured easily, in particular by milling.

[0015] Preferably, the valve seat has a flow channel, the flow channel being arranged relative to the valve member such that, in the open state of the valve member, the flow channel opens into a discharge port of the flow connection. The flow channel can preferably be designed as a nozzle.

[0016] It is particularly provided that a check valve element is provided on the valve body downstream of the valve seat, wherein the check valve element is designed as an O-ring arranged on the valve body. Preferably, the valve body has a first free longitudinal end and a second longitudinal end, wherein the valve body is supported at its second longitudinal end in the direction of the longitudinal center axis by an axial bearing on the valve housing. Preferably, the axial bearing comprises a receptacle formed at the second end of the valve body and at least one ball held in the receptacle, wherein the valve body is supported against the valve housing by the ball. The ball held in the receptacle represents a simple axial bearing design and serves to minimize friction when the valve body pivots. It may also be advantageous to provide several balls for supporting the valve body.

[0017] Further features of the invention will become apparent from the description and the drawing, in which an embodiment of the invention, described in detail below, is illustrated. The drawing shows: Fig. 1 shows a perspective, schematic view of a high-pressure cleaner; Fig. 2 shows a schematic view of a pressure adjusting device connected to a pressure line and a suction line of a high-pressure cleaner; Fig. 3 shows a perspective view of a valve body and a valve seat of the pressure adjusting device. Fig. 2 Fig. 4 shows a perspective, partial view of the valve body with cam; Fig. 5 shows a sectional view of the pressure adjusting device with valve seat; Fig. 6 shows a sectional view along the section line between arrows VI. Fig. 5The pressure adjusting device, Fig. 7 in a sectional view of the valve body with valve seat in closed and reference positions, Fig. 8 in a sectional view of the pressure adjusting device in the reference position, Fig. 9 in a partial sectional view of the arrangement of the valve element and the valve seat in the reference position, Fig. 10 in a sectional view of the pressure adjusting device in the starting position, Fig. 11 in a partial sectional view of the arrangement of the valve element and the valve seat in the starting position, Fig. 12 in a sectional view of the pressure adjusting device in the closed position, Fig. 13 in a partial sectional view of the arrangement of the valve element and the valve seat in the closed position, and Fig. 14 a schematic diagram of the pressure curve as a function of the swivel angle.

[0018] Fig. 1Figure 1 shows a schematic representation of an embodiment of the high-pressure cleaner 1 according to the invention. The high-pressure cleaner 1 comprises a housing 2 that surrounds individual system components of a hydraulic unit and protects them, for example, from splashing water. A low-pressure connection 4 is provided on the housing 2, through which a suction line 5 ( Fig. 2The high-pressure cleaner 1 can be connected to an external liquid connection, in particular a water connection. Accordingly, a cleaning fluid is supplied to the high-pressure cleaner 1 via the low-pressure connection 4 during its operation. The cleaning fluid is preferably water. Other liquids, for example water mixed with a cleaning agent, can also be used as the cleaning fluid. A hose reel 7 is provided on the housing 2 of the high-pressure cleaner 1. A high-pressure hose 8 is wound on the hose reel 7. The high-pressure hose 8 is connected at one end to a pressure line 6 of the high-pressure cleaner 1 ( Fig. 2 ). A pressure connection 9 is provided at the other end of the high-pressure hose 8, to which a spray nozzle 3 ( Figure 2 ), for example, a spray gun with a nozzle head, can be connected.

[0019] As in Fig. 1As shown, the high-pressure cleaner 1 includes an operating switch 60 by means of which the high-pressure cleaner 1 can be switched on and off. In addition, a handle 61 is provided on the top of the housing 2. The high-pressure cleaner 1 can be lifted by its handle 61, in particular carried, or pulled on its wheels 62 located on the underside of the housing 2.

[0020] As in Fig. 2As shown, the high-pressure cleaner 1 comprises a pump 63 driven by a drive motor 64. In this exemplary embodiment, the drive motor 64 is an electric motor. Other types of drive motors 64 are also conceivable in alternative embodiments of the high-pressure cleaner 1. Liquid is supplied to the pump 63 via the suction line 5. Driven by the drive motor, the pump 63 delivers the liquid under high pressure into the pressure line 6. Check valves 65 are provided on the pump 63 to prevent pressure equalization of the liquid between the pressure line 6 and the suction line 5 via the pump 63. When the spray nozzle 3 is closed, the pressure in the pressure line 6 increases. Once a limit pressure is reached in the pressure line 6, the drive motor 64 is switched off. A pressure cut-off valve can be provided for this purpose, for example.When the spray attachment 6 is open, the liquid flows from the pump 63 via the pressure line 6 to the nozzle head of the spray attachment 3 and flows out there at high speed.

[0021] As in Fig. 2 As shown, the high-pressure cleaner 1 includes a pressure adjusting device 10. The pressure adjusting device 10 is functionally arranged between the pressure line 6 and the suction line 5. The pressure adjusting device 10 is designed such that it is in an open state ( Fig. 3) a flow connection 70 between the pressure line 6 and the suction line 5 is opened. Consequently, the cleaning fluid flows under high pressure from the pressure line 6 via the pressure adjusting device 10 to the suction line 5. A leakage flow occurs between the pressure line 6 and the suction line 5, which causes a pressure drop in the pressure line 6. As the pressure in the pressure line 6 decreases, the volume flow at the nozzle head of the spray attachment 3 also decreases, and thus the velocity at which the fluid flows out of the spray attachment 3 also decreases. The pressure adjusting device 10 is designed such that the leakage flow between the pressure line 6 and the suction line 5, and thus also the pressure in the pressure line 6, is adjustable. If the pressure adjusting device 10 is in a closed position 31, the flow connection 70 between the pressure line 6 and the suction line 5 via the pressure adjusting device 10 is closed.In the closed position 31 of the pressure adjusting device 10, there is no flow loss. The pressure in the pressure line 6 is at its maximum when the high-pressure cleaner 1 is in operation in the closed position 31 of the pressure adjusting device. Consequently, the flow rate at the nozzle head of the spray attachment 3 is also at its maximum.

[0022] As in Fig. 2 As shown, the pressure adjusting device 10 comprises a valve housing 11 and a valve body 13 with a valve element 15. The valve body 13 is pivotably mounted in the valve housing 11 about its longitudinal center axis 14. The pressure adjusting device 10 includes a valve seat 12, the valve seat 12 being operatively connected to the valve element 15 of the valve body 13. The pressure adjusting device 10 also includes an inlet 16 for supplying the fluid. The pressure adjusting device 10 includes an outlet 17 for discharging the fluid. As shown in Fig. 2As shown, the inlet 16 of the pressure adjusting device 10 is connected to the pressure line 6 of the high-pressure cleaner 1. The outlet 17 of the pressure adjusting device 10 is connected to the suction line 5 of the high-pressure cleaner 1. In an alternative embodiment of the pressure adjusting device 10, multiple inlets 16 and / or multiple outlets 17 may also be provided.

[0023] As in Fig. 3 As shown, the valve body 13 is designed as a spindle. The valve body 13 extends along its longitudinal center axis 14 from its first longitudinal end 41 to its second longitudinal end 42. An actuating section 49 is formed at the first longitudinal end 31. The actuating section 49 is equipped with an actuating unit 50 ( Fig. 6The valve body 13 can be pivoted about its longitudinal center axis 14 via the actuating unit 50. In the exemplary embodiment, the actuating unit 50 is positively connected to the valve body 13. For this purpose, the actuating section 49 is designed as a flat edge. In an alternative embodiment of the pressure adjusting device 10, it may be advantageous to provide other types of connection, for example a frictional connection, between the actuating unit 50 and the valve body 13.

[0024] As in Fig. 3As shown, the valve body 13 comprises at least one circumferentially formed first bearing section 28. The preferred embodiment of the pressure adjusting device 10 comprises, in addition to the first bearing section 28, a second bearing section 29. Both bearing sections 28, 29 are formed on the circumferential surface of the valve body 13. The first bearing section 28 adjoins the mounting section 49 directly. The second bearing section 29 is formed at the second longitudinal end 42 of the valve body 13. As shown in particular in the Figures 5 and 6As shown, the valve body 13 is pivotably mounted on the valve housing 11 via a bearing arrangement. In the exemplary embodiment, the bearing arrangement comprises two radial bearings 51, 52. The first bearing 51 is located on the first bearing section 28, and the second bearing 52 on the second bearing section 29 of the valve body 13. The number of bearing sections 28, 29 of the valve body 13 corresponds to the number of radial bearings 28, 29. In the preferred embodiment, the bearings 51, 52 are designed as needle bearings. Of course, in an alternative embodiment, the bearings can also be designed as plain bearings, in particular as graphite bearings or similar. It may also be advantageous to provide only one radial bearing or more than two radial bearings.

[0025] As in Fig. 3As shown, the valve body 13 encompasses the valve element 15 with a flow unit 30 on its circumferential side. The valve seat 12 is associated with the valve element 15. The valve seat 12 is formed by a channel insert 39 arranged in the valve housing 11. This simplifies the manufacture of the valve seat 12. It may also be advantageous to form the valve seat 12 directly on the valve housing 11. The channel insert 39 comprises a flow channel 38. One end of the flow channel 38 is directly adjacent to the inlet 16 of the pressure adjusting device 10. The other end of the flow channel 38 is adjacent to the valve element 15.

[0026] When the pressure adjusting device 10 is in the closed position 31, the valve seat 12 is closed by the valve element 15. Accordingly, the valve element 15 rests against the valve seat 12, in particular against the channel insert 39, such that the flow channel 38 is closed at its end facing the valve element 15. The flow connection 70 between the inlet 16 and the outlet 17 is interrupted. When the pressure adjusting device 10 is in the open position 32, the flow connection 70 between the inlet 16 and the outlet 17 is released. In the open position 32 of the pressure adjusting device 10, the valve body 13 is pivoted such that the flow unit 30 of the valve element 15 rests against one end of the flow channel 38. In the open state 32 of the pressure adjusting device 10, the flow channel 38 opens into an outflow opening 25 of the flow unit 30, thereby releasing the flow connection 70 between the inlet 16 and the outlet 17.

[0027] As in the Figures 3 , 5 , 6As shown, the valve body 13 comprises a flow section 56 formed on its circumferential side. The flow section 56 surrounds the flow unit 30. The flow section 56 of the valve body 13 is spaced apart from the valve housing 11. Accordingly, fluid flows in the region of the flow section 56 between the valve housing 11 and the valve body 13. Furthermore, the valve body 13 comprises an inner channel 53. The valve body 13 has a first connecting opening 54 through which the inner channel 53 is fluid-connected to the flow section 56 of the valve body 13. The valve body 13 has a second connecting opening 55, the connecting opening 55 extending from the circumferential side of the valve body 13 to the inner channel 53, thereby fluid-connecting the latter to the outlet 17. The connecting openings 54, 55 are preferably designed as bores.

[0028] As in Fig. 3As shown, the pressure adjusting device 10 is designed such that in its open state 32 the flow connection 70 from the inlet 16 to the outlet 17 is via the flow channel 38, the flow unit 30, the flow section 56, the first connecting opening 54, the inner channel 53 and the second connecting opening 55.

[0029] As in Fig. 5As shown, the flow section 56 is sealed by two seals 57, 58 arranged between the valve body 13 and the valve housing 11. The first seal 57 and the second seal 58 each sit in a groove provided in the valve body 13. In the preferred embodiment, the seals 57, 58 are formed by O-rings. Furthermore, the pressure adjusting device 10 includes a third seal 59. The second connecting opening 55, and thus also the outlet 17, is sealed by the second seal 58 and by the third seal 59. The third seal 59 is also designed as an O-ring and is arranged in a groove of the valve body 13. The entire flow connection 70 is sealed from the first bearing 51 by the first seal 57. The entire flow connection 70 is sealed from the second bearing 52 by the third seal 59.

[0030] As in Fig. 5As shown, the pressure adjusting device 10 comprises a check valve 26, wherein the check valve 26 is functionally arranged upstream of the outlet 17 and prevents flow from the outlet 17 towards the inlet 16. In the preferred embodiment, the check valve 26 is designed as a sealing ring, in particular as an O-ring. The check valve 26 lies in a groove 27 formed on the circumferential side of the valve body 13. The second connecting opening 55 opens into the groove 27. In the exemplary embodiment, the groove 27 is wedge-shaped, with the side surfaces of the groove 27 converging towards the longitudinal center axis 14.The arrangement of check valve element 26 and groove 27 is designed such that, in the closed position 31 of the pressure adjusting device 10, the check valve element 26 seals against the groove 27, and in the open position 32 of the pressure adjusting device 10, the check valve element 26 is expanded radially outwards by the pressure of the liquid, thus releasing the flow connection 70. When, in the closed position 31, pressure of the liquid acts from the outlet 17 towards the inlet 16, the check valve element 26 is pressed against the groove 27, thereby sealing the second connection opening 55. Backflow of the liquid from the outlet 17 to the inlet 16 is prevented.

[0031] As in Fig. 6As shown, the pressure adjusting device 10 comprises the actuating unit 50 for pivoting the valve body 13 about the longitudinal center axis 14. In the exemplary embodiment of the pressure adjusting device 10, the actuating unit 50 is rotationally fixed to the valve body 13 via the actuating section 49 of the valve body 13. In this exemplary embodiment, the actuating unit 50 is designed as a rotary knob. The valve body 13 can be pivoted manually by means of the rotary knob. In the present exemplary embodiment, the rotary knob is held directly on the actuating section 49. It can also be provided that the actuating unit 50 has a gearbox. In such a design, the operating element, here the push button, is operatively connected to the actuating section 50 of the valve body 13. The actuating unit 50 is designed such that stepless pivoting of the valve body 13 is provided.In an alternative embodiment, it may be advantageous for the actuating unit 50 to have a detent. The detent provides several pivoting positions, in particular three pivoting positions. It may also be advantageous to provide more than three pivoting positions, in particular four or five pivoting positions. In a further alternative embodiment of the pressure adjusting device 10, it may be advantageous for the actuating unit 50 to be designed as a push button with a clamping mechanism, in particular a locking clamping mechanism. In such an embodiment, the actuating unit 50 also provides several pivoting positions of the valve body 13. In a further alternative embodiment of the pressure adjusting device 10, not shown in detail, the actuating unit 50 comprises an actuator or a stepper motor for pivoting the valve body 13. The pivoting of the valve body 13 can then be motorized or automatic.The swivel angle is then preferably determined depending on the control element provided on the spray attachment and operated by the operator.

[0032] As in Fig. 5As shown, the valve body 13 is mounted relative to the valve housing 11 in the direction of its longitudinal center axis 14, i.e., in the axial direction of the valve body 13. The pressure adjusting device 10 includes a thrust bearing 43. The thrust bearing 43 is arranged at the second longitudinal end 42 of the valve body 13. The thrust bearing 43 comprises at least one receptacle 44 and at least one ball 45 held in the receptacle 44. The receptacle 44 is aligned coaxially with the longitudinal center axis 14. Thus, the longitudinal center axis 14 of the valve body 13 intersects the ball 45 at its center point. The receptacle 44 is formed by a blind hole 67 in a closure element 66. The closure element 66 is located at the second longitudinal end 42 of the valve body 13. The inner channel 53 is designed as a blind hole.The closing element 66 projects into the inner channel 53, wherein a seal is arranged between the closing element 66 and the valve body 13 to seal the inner channel 53 towards the second longitudinal end 42 of the valve body 13.

[0033] As in Fig. 5As shown, the valve housing 11 has a mounting opening 73 for inserting the valve body 13 into the valve housing 11. Once the valve body 13 is positioned in the valve housing 11, the mounting opening 73 must be closed. For this purpose, the valve housing 11 includes a closure unit 71. The closure unit 71 comprises a sealing screw 76 with a thread 72, an insert 74, and a support ball 75 held in the insert 74. The sealing screw 76 is screwed to the base body 69 of the valve housing 11, with a seal, in particular a sealing ring, arranged between the sealing screw 76 and the base body 69. The insert 74 held in the sealing screw 76 is aligned coaxially with the longitudinal center axis 14. The support ball 75 is also arranged in the insert 74 such that the longitudinal center axis 14 of the valve body 13 intersects the support ball 75 at its center point. The ball 45 and the support ball 75 make contact.The ball 45 is rotatably mounted in its receptacle 44. The support ball 75 is rotatably mounted in its insert. Due to the point contact between the ball 45 and the support ball 75, the frictional forces opposing the pivoting movement of the valve body 13 are minimized.

[0034] In the preferred embodiment, the components of the axial bearing 43 are the receptacle 44, the ball 45, the insert 74 and the support ball 75. The force flow of the acting axial forces runs via the valve body 13, the receptacle 44, the ball 45, the support ball 75, the insert 74, the sealing screw 76 via the thread 72 into the base body 69 of the valve housing 11.

[0035] The pressure adjusting device 10 has a minimum flow cross-section 19 within the flow connection 70 between the inlet 16 and the outlet 17. The minimum flow cross-section 19 is the region of the flow connection 70 in which the minimum flow cross-section exists. The minimum flow cross-section 19 is provided in the flow unit 30. The flow unit 30 is designed such that the minimum flow cross-section is adjustable. Accordingly, the valve element 15, the flow unit 30, and the valve seat 12 form an adjustable throttle valve. Thus, the flow rate of the flow connection 70 between the inlet 16 and the outlet 17 can be adjusted by the flow unit 30, thereby adjusting the pressure at the inlet 16 and thus in the pressure line 6 of the high-pressure cleaner 1.

[0036] In the Figures 3 and 4The flow unit 30 of the valve member 15 is shown. The flow unit 30 comprises the following: In the exemplary embodiment, the flow unit 30 is designed as a cam 18. The cam 18 is formed on a circumferential section 20 of the valve body 13. The cam 18 is designed as a groove. The cam 18 comprises a first side surface 77, a second side surface 78, and a cam base 79 connecting the side surfaces 77 and 78. In the closed position 31 of the pressure adjusting device 10, the valve member 15 is aligned with respect to the valve seat 12 such that the flow channel 38, at its end facing the valve member 15, rests completely on the circumferential section 20 outside the cam 18. The flow channel 38 is closed by the circumferential section 20 of the valve body 13.To release the flow channel 38, the valve body 13 with the valve element 15 must be pivoted until the flow channel 38 opens into the cam 18, in particular into the outflow opening 25 of the cam 18.

[0037] As in Fig. 4As shown, the cam 18 has a varying depth t of the cam base 79. The depth t of the cam base 79 is measured radially to the longitudinal center axis 14. The cam 18 has a width b, which corresponds to the distance between the side surfaces 77, 78, measured in the direction of the longitudinal center axis 14. In the exemplary embodiment, the width b of the cam 18 is constant. Due to the varying depth t of the cam base 79, the size of the minimum flow cross-section 19 is determined depending on a pivot angle α of the valve body 13 and the associated positioning of the valve seat 12 relative to the cam 18. In an alternative embodiment of the pressure adjusting device 10, it may also be advantageous to vary the width b of the cam 18 in order to adjust the minimum flow cross-section 19.

[0038] In Fig. 7A schematic sectional view, viewed along the longitudinal center axis 14, shows the arrangement of the valve body 13 and the valve seat 12 in the open position 32 and in the closed position 31. The valve body 13 is shown with dashed lines in the closed position 31. In the closed position 31, the cam 18 lies outside the end of the flow channel 38 facing the valve member 15. The flow channel 38 is closed by the circumferential section 20 of the valve member 15. The flow connection 70 between the inlet 16 and the outlet 17 of the pressure adjusting device 10 is interrupted. The valve body 13 is to be pivoted from the closed position 31 in a first pivoting direction 47 about the longitudinal center axis 14 of the valve body 13 into the open position 32. In the open state 32, the flow channel 38 flows into the backdrop 18 and the flow connection 70 is released.Preferably, the swivel angle α of the valve body 13 is limited by mechanical stops (not shown in detail). The maximum swivel angle α is the angle through which the valve body 13 swivels from the closed position 31 to the open position 32, in which the minimum flow cross-section 19 is maximized. The maximum swivel angle α lies in a range of 0° to 360°, preferably from 0° to 270°, particularly from 0° to 180°, and most preferably from 0° to 90°. It is particularly preferred that the maximum swivel angle α is at most 90°. It is particularly preferred that the maximum swivel angle α is at least 30°, and more preferably at least 60°.

[0039] As especially in the Figure 4As shown, the cam 18 is formed from three successive sections 81, 82, 83, namely the first section 81, the second section 82, and the third section 83. Sections 81, 82, and 83 each consist of an approximately flat surface that forms the cam base 79. In a preferred embodiment, the valve body 13 is made of a metallic material. In a preferred embodiment, the cam 18 is milled. In a first machining step, the second section 82 is milled, with the second section 82 being located between the first section 81 and the third section 83. Subsequently, the first section 81 and the second section 83 are milled successively. In an alternative embodiment, it may be advantageous for the valve body 13 to be made of plastic. In such an embodiment, the cam 18 can also be milled.Preferably, the cam 18 is already manufactured during the casting process, in particular in an injection molding process of the valve body 13. If the valve body 13 is cast, the flow unit 30 can also be formed in the form of one or more openings in the circumferential section 20 instead of the cam 18.

[0040] In the present embodiment, sections 81, 82, 83 are formed by chords 37, 37', 37" with respect to a cross-sectional area 36 of the valve body 13, as shown in the Figures 8 to 13 As shown in these figures, the valve element 15 is intersected by a transverse plane 35 oriented perpendicular to the longitudinal center axis 14. The transverse plane 35 intersects the valve element 15 at the cam 18 in a cross-sectional area 36. Within the area of ​​the cam 18, the cross-sectional area 36 is bounded by the chords 37, 37', 37" forming the cam 18. Outside the chords 37, 37', 37" the cross-sectional area 36 is bounded by a circular arc 84 of the circumferential section 20.

[0041] The chords 37, 37', 37" each have a distance c" from the longitudinal center axis 14. The distance c of the first chord 37 of the first section 81 of the cam 18 to the longitudinal center axis 14 is greater than the distance c' of the second chord 37' of the second section 82 of the cam 18 to the longitudinal center axis 14. The distance c' of the second chord 37' of the second section 82 of the cam 18 to the longitudinal center axis 14 is greater than the distance c" of the third chord 37" of the third section 83 of the cam 18 to the longitudinal center axis 14.

[0042] As in Fig. 9As shown, the cam 18 of the valve element 15 extends from a first end 21 to a second end 22 over an angular distance β measured with respect to the longitudinal center axis 14. In the exemplary embodiment, the angular distance β is preferably at least 30°. Preferably, the angular distance β is at least 60°, in particular at least 90°, preferably approximately 120°. Advantageously, the angular distance β between the first end 21 and the second end 22 of the cam 18 is at most 270°, preferably at most 180°, in particular at most 150°.

[0043] In the Figures 8 and 9The pressure adjusting device 10 is shown in an open state 32, where the minimum flow cross-section 19 is at its maximum. The valve element 15 is oriented relative to the valve seat 12 such that a first valve opening 85 and a second valve opening 86 are formed on the cam between the cam 18 and the valve seat 12. Accordingly, the flow connection 70 from the flow channel 38 towards the first end 21 of the cam 18 occurs via the second valve opening 86, and towards the second end 22 of the cam 18 via the first valve opening 85. The minimum flow cross-section 19 is essentially determined by the distance between the cam base 79 of the cam 18 and the valve seat 12.The minimum flow cross-section 19 results from a first minimum flow cross-section 19' in the flow direction towards the first valve opening 85 and from a second minimum flow cross-section 19" in the flow direction towards the second valve opening 86. In this open position 32 after . Fig. 9 The first minimum flow cross-section 19' is formed directly at the second valve opening 86 between the valve seat 12 and the first chord 37 of the cam 18. The second minimum flow cross-section 19" is formed between the valve seat 12 at the end of the flow channel 38 and the third chord 37" of the cam 18. Starting from the valve openings 85, 86, the flow connection 70 is established via a flow chamber 87, which is bounded by the flow section 56 of the valve body 13 and the valve housing 11.

[0044] The one in the Figures 8 and 9The open state 32 shown is preferably used in an embodiment of the pressure adjusting device 10 in which the actuating unit 50 is motorized. In such an embodiment, the open state 32 forms a reference position of the valve body 13 relative to the valve seat 12, wherein a stop is preferably provided on the valve body 13 which, in this position, contacts the valve seat 11 or the housing 12. A control unit (not shown in detail) thus detects the position of the valve body 13.

[0045] In the Figures 10 and 11The pressure adjusting device 10 is shown in an open state 32. The valve body 13 is oriented such that the second valve opening 86 is closed. Accordingly, the valve body 13 is positioned relative to the valve seat 12 such that the first end 21 of the cam 18 rests against the valve seat 12. The valve body 13 is oriented such that only the first valve opening 85 is open. In this position of the valve element 15, the minimum flow cross-section 19 is formed by the distance between the second chord 37' of the second section 82 of the cam 18 and the valve seat 12 at the end of the flow channel 38. In the preferred embodiment, this position between the valve element 15 and the valve seat 12 forms the starting position 33 of the pressure adjusting device 10. Accordingly, the pressure loss flow rate is adjusted.The pressure at the inlet 16 of the pressure adjusting device 10 of the valve body 13 is only pivoted between the starting position 33 and the closed position 31. Since at most the first valve opening 85 is open in this angular range, the minimum flow cross-section 19 and thus also the pressure at the inlet 16 can be controlled more easily.

[0046] As in the Figures 10 and 11As shown, the cam 18 is designed such that the minimum flow cross-section 19 decreases when pivoting in the first pivoting direction 48 from the starting position 33 of the valve body 13. The cam 18 is designed such that the size of the minimum flow cross-section 19 decreases at least partially linearly as the valve body 13 pivots in the first pivoting direction 48. The linear increase of the minimum flow cross-section 19 preferably occurs when the valve body 13 pivots from the starting position 33 to an intermediate position 80. The intermediate position 80 is present when the minimum flow cross-section 19 is formed by the distance between a connecting edge 88 and the valve seat 12. The connecting edge 88 is formed between the first chord 37 of the first section 81 and the second chord 37' of the second section 82.A further linear increase in the minimum flow cross-section 19 preferably occurs when pivoting the valve body 13 from the intermediate position 80 to the closed position 31.

[0047] In the Figures 12 and 13 The pressure adjusting device 10 is shown in the closed position. In the closed position 31 of the pressure adjusting device 10, the opening of the flow channel 38 facing the valve element 15 is completely closed by the circumferential section 20 of the valve element 15. The cam 18 is located outside the opening of the flow channel 38 facing the valve element 15. The flow connection 70 between inlet 16 and outlet 17 is interrupted. Therefore, there is no flow loss. The pressure at inlet 16 is at its maximum.

[0048] As in the Figures 10 to 13As shown, the cam 18 is designed such that the minimum flow cross-section 19 decreases continuously when pivoting from the starting position 33 to the closed position 31. Accordingly, the pressure at the inlet 16 increases continuously when pivoting from the starting position 33 to the closed position 31.

[0049] In Fig. 14A diagram is shown depicting the pressure at inlet 16 as a function of the pivot angle α, starting from the reference position 34. The pressure increases continuously from the starting position 33 to the closed position 31. At the intermediate position 80, a slight plateau is formed due to the connecting edge 88 between the first section 81 and the second section 82. If the pressure is adjusted in steps, it is advantageous to provide an intermediate step in the region of the intermediate position 80. In the region of the plateau, the slope of the pressure curve is extremely small, and therefore the pressure change around the intermediate position is also extremely small. This ensures that the desired target pressure for the intermediate position 80 can be reliably achieved even with an imprecise angular position of the actuating unit 50.

[0050] In the reference position 34 of the pressure adjusting device 10, the pressure at the inlet 16 is preferably in a range between 30 and 50 bar. In the starting position 33 of the pressure adjusting device 10, the pressure at the inlet 16 is preferably in a range between 40 and 60 bar. In the intermediate position 80 of the pressure adjusting device 10, the pressure at the inlet 16 is preferably in a range between 70 and 90 bar. In the closed position 31 of the pressure adjusting device 10, the pressure at the inlet 16 is preferably in a range between 120 and 150 bar.

Claims

1. High-pressure cleaner with a pressure-adjusting device, said pressure-adjusting device comprising a valve housing (11) with a valve seat (12), at least one inlet (16) for supply of a liquid, at least one outlet (17) for discharge of the liquid, and a valve body (13) with a longitudinal central axis (14), wherein the valve body (13) is mounted in the valve housing (11) so as to be pivotable about its longitudinal central axis (14), wherein the valve body (13) has a valve member (15), assigned to the valve seat (12), circumferentially in relation to the longitudinal central axis (14), wherein, in a closed position (31) of the valve body (13), the valve seat (12) is closed off by the valve member (15) and the flow connection between the inlet (16) and the outlet (17) is interrupted, wherein the valve body (13) is pivotable about its longitudinal central axis (14) from the closed position (31) into an open state (32), wherein, in the open state (21), a flow connection between the inlet (16) and the outlet (17) is provided with a minimum throughflow cross-section (19), wherein the minimum throughflow cross-section (19) is formed by a flow unit (30) formed on the valve member (15) and the valve member (15) is formed in such a way that the size of the minimum throughflow cross-section (30) is settable as a function of a pivot angle (α) of the valve body (13) about its longitudinal central axis (14).

2. High-pressure cleaner according to Claim 1, wherein the maximum pivot angle (α) lies in a range from 0° to 360°, in particular from 0° to 270°, preferably from 0° to 180°, with preference from 0° to 90°.

3. High-pressure cleaner according to Claim 1 or 2, wherein the flow unit (30) is in the form of a slotted guide (18) on a circumferential portion (20) of the valve member (15).

4. High-pressure cleaner according to Claim 3, wherein the slotted guide (18) of the valve member (15) extends from a first end (21) to a second end (22) over an angular interval (β) measured in relation to the longitudinal central axis (14), wherein the angular interval (β) is at least 30°.

5. High-pressure cleaner according to Claim 4, wherein the angular interval (β) between the first end (21) and the second end (22) of the slotted guide (18) is at most 270°.

6. High-pressure cleaner according to one of Claims 3 to 5, wherein the slotted guide (18) is formed in such a way that the pressure at the inlet (16) is adjustable in a continuous manner.

7. High-pressure cleaner according to one of Claims 1 to 6, wherein the slotted guide (18) is formed in such a way that the size of the minimum throughflow cross-section (19) is, at least partially, settable linearly as a function of the pivot angle (α) of the valve body (13) about its longitudinal central axis (14).

8. High-pressure cleaner according to one of Claims 1 to 7, wherein the valve member (15) has a transverse plane (35) which is oriented perpendicularly to the longitudinal central axis (14), wherein the transverse plane (35) intersects the valve body (13) at the slotted guide (18) on a cross-sectional surface (36), wherein the cross-sectional surface (36) at the slotted guide (18) is delimited by multiple chords (37, 37', 37").

9. High-pressure cleaner according to one of Claims 1 to 8, wherein the valve seat (12) has a flow channel (38), wherein the flow channel (38) is arranged in relation to the valve member (15) in such a way that, in the open state (32) of the valve member (15), the flow channel (38) opens out into an outflow opening (25) of the flow connection (30).

10. High-pressure cleaner according to one of Claims 1 to 7, wherein a non-return element (26) is provided on the valve body (13) downstream of the valve seat (12), wherein the non-return element (26) is in the form of an O-ring arranged on the valve body (13).

11. High-pressure cleaner according to one of Claims 1 to 10, wherein the valve body (13) has a first, free, longitudinal end (41) and a second longitudinal end (42), wherein, at its second longitudinal end (42), the valve body (13) is mounted on the valve housing (11) in the direction of the longitudinal central axis (14) via an axial bearing (43).

12. High-pressure cleaner according to Claim 11, wherein the axial bearing (43) comprises at least one receptacle (44), which is formed at the second longitudinal end (22) of the valve body (13), and at least one ball (45), which is held in the receptacle (44), wherein the valve body (13) is supported in relation to the valve housing (11) via the at least one ball (45).

13. High-pressure cleaner according to one of Claims 1 to 12, wherein the pressure-adjusting device (10) comprises an actuating unit (50) which acts on the first longitudinal end (41) of the valve body (13) and which serves for pivoting the valve body (13).

14. High-pressure cleaner according to Claim 13, wherein the actuating unit (50) comprises an actuating motor or stepper motor for pivoting the valve body (13).

15. High-pressure cleaner according to Claim 13, wherein the actuating unit (50) has a detent means for stepwise pivoting of the valve body (13).