Suction appliance and method for operating same

Abstract

The present invention relates to a suction appliance comprising a collection container, a filter for cleaning the air flow loaded with suctioned material, and a motor for driving a turbine, the turbine being designed to generate a negative pressure and thus an air flow for suctioning in the suctioned material. The suction appliance comprises a plunger, which is designed to be movable in order to perform a filter cleaning process and opens a first channel in a suction-mode position and closes the first channel when moved into a filter-cleaning position, the air between the plunger and the filter being compressed such that an ejection of compressed air is pushed through the filter and the filter is cleaned thereby. In a second aspect, the invention relates to a method for operating such a suction appliance, in which filter cleaning can be brought about by moving a single plunger.

Description

[0001] SUCTION DEVICE AND METHOD FOR ITS OPERATION

[0002] The present invention relates to a suction device with a collecting container, with a filter for cleaning the air flow laden with suction material, and with a motor for driving a turbine, wherein the turbine is designed to generate a vacuum and thus an air flow for sucking in the suction material. The suction device has a piston which is designed to be movable in order to carry out filter cleaning and which, in a suction operating position, opens a first channel and, by moving into a filter cleaning position, closes the first channel, wherein the air between the piston and the filter is compressed in such a way that a burst of compressed air is forced through the filter and the filter is thus cleaned. In a second aspect, the invention relates to a method for operating such a suction device, in which filter cleaning can be effected by the movement of an individual piston.

[0003] Background of the invention:

[0004] In the field of industrial or construction vacuum cleaners, it is well known that the filters of the vacuum cleaners must be cleaned regularly to ensure efficient operation of the device. Various systems and methods are known in the art for cleaning the filters. The most common mechanisms include backwashing or mechanically shaking the filter.

[0005] In mechanical shaking, a special device such as a comb, a shaker or the like is often provided to cause mechanical shaking of the filter.

[0006] Backflushing usually involves introducing external air into the vacuum cleaner, with the external air preferably being passed abruptly through the vacuum cleaner in the opposite direction of the suction flow. This allows the filter to be rinsed and cleaned. The disadvantage of backflushing, however, is that the suction flow must be reversed or paused during cleaning in order to clean the filter. This means that the suction function of the vacuum cleaner is limited during cleaning. If the vacuum cleaner is connected to a machine tool to extract the dust generated during operation of the machine tool, the dust exposure for the machine tool user can increase during filter cleaning.

[0007] Until now, this disadvantage was often addressed by using two filters and two cleaning systems in vacuum cleaners. With these two-filter systems, one filter can remain active at all times, allowing the suction flow to pass through this active filter while the other, "inactive" filter is cleaned. However, the disadvantage of these two-filter systems is that they are space-intensive and take up a lot of room in a construction vacuum cleaner because the corresponding cleaning system must be installed twice, one for each filter.

[0008] The object underlying the present invention is to overcome the above-described deficiencies and disadvantages of the prior art and to provide an alternative method or mechanism for cleaning a filter in a vacuum cleaner. This eliminates the need for mechanical shaking and a two-filter system. In particular, an effective, compact, and space-saving cleaning mechanism is to be provided, allowing suction operation to be maintained even during the cleaning process.

[0009] The problem is solved by the subject matter of the independent claims. Advantageous embodiments of the subject matter of the independent claims can be found in the dependent claims.

[0010] Description of the invention:

[0011] According to the invention, a suction device is provided, wherein the suction device comprises a collecting container for receiving suction material, a filter for cleaning the air flow laden with suction material and a motor for driving a turbine, wherein the turbine is designed to generate a vacuum and thus an air flow or suction flow for sucking in the suction material. The suction device has a piston which is designed to be movable for carrying out filter cleaning and which, in a suction operation position, opens a first channel and closes the first channel by moving into a filter cleaning position, wherein the air between the piston and the filter is compressed in such a way that a burst of compressed air is forced through the filter and the filter is thus cleaned.

[0012] The piston is preferably designed to open the first channel in the suction mode position and to close the first channel in the filter cleaning position. Within the meaning of the invention, the piston can preferably also be referred to as a single piston. This wording is intended to preferably express that the suction device comprises precisely one piston for carrying out the filter cleaning. The invention thus departs from filter cleaning systems known from the prior art, in which two pistons are provided, each cleaning a filter or a filter section of a filter, while the suction operation is maintained via the other filter or filter section.The single-piston design described here allows for a particularly space-saving and compact filter cleaning mechanism that, moreover, requires a very small amount of backwash air while still achieving a good cleaning effect. Surprisingly, by providing a second channel, designed as a bypass channel and described further below, suction operation can also be maintained during filter cleaning. The present invention further realizes the advantages of so-called dual-filter systems without the disadvantages, such as high space requirements.

[0013] According to the invention, it is preferred that air laden with suction material is sucked in through an opening within the suction device ("suction inlet") and forms a suction flow. The suction flow flows through the collecting container for suction material ("dust collection container"), where a large portion of the suction material or dust is deposited. The suction flow is then passed through a filter, through which the suction flow is further cleaned. The suction flow is generated by a turbine driven by a motor of the suction device. The turbine and the motor are arranged behind the filter in the suction direction, whereby the proposed suction device can have a piston chamber directly behind the filter and then an intermediate section before the turbine and the motor are connected. In other words, the suction device can have an intermediate section arranged between the motor and the piston chamber, whereby the intermediate section forms a partial section of the first channel.A possible design of the suction device is shown in the figures.

[0014] The suction device can be connected to a machine tool, such as a drill, a saw, a chisel, or a cutting or grinding device, wherein the suction device is configured to vacuum the dust generated during work with the machine tool. Thus, the vacuumed material can particularly comprise dust or dust particles. However, it can also be preferred for the suction device to be designed as a wet / dry vacuum cleaner and can vacuum wet dust or a mixture of vacuumed material and liquid. The machine tool and the suction device can be communicatively, mechanically, and / or electrically connected to one another in a known manner. The suction device comprises a piston that is designed to be movable for carrying out filter cleaning.In the context of the invention, this preferably means that the piston can move back and forth at least between a suction mode position and a filter cleaning position, whereby the movement of the piston from the suction mode position to the filter cleaning position can initiate a filter cleaning or a filter cleaning process. The movement of the individual piston can be caused, for example, by incoming external air or by guided process air, i.e., air present in the suction device.

[0015] In the context of the invention, it is preferred that the filter to be cleaned has no contact with the air used to move the piston. Advantageously, in the context of the present invention, the filter is not exposed to external air. Rather, the filter is cleaned by a pressure pulse generated by the movement of the piston and by the compression of the air in the compression zone. This compressed air is forced through the filter with the help of the piston, so that the filter is both mechanically shaken and backwashed by the pressure pulse. In this way, the proposed filter cleaning system with a single piston combines the advantages of known cleaning systems without being space-intensive and without the suction coming to a standstill during filter cleaning.In particular, the invention offers an alternative possibility for a filter cleaning mechanism, which is particularly suitable when a compact filter cleaning unit is desired for a suction device or when little installation space is available.

[0016] According to the invention, it is preferred that the first channel is arranged between the motor of the suction device and the filter, wherein the first channel is designed as a suction channel and runs at least in sections through a piston chamber of the suction device. The piston chamber is preferably arranged behind the filter and in front of the motor or turbine in the direction of the suction flow. The piston of the suction device can be movably received in the piston chamber so that the piston can perform a linear or axial movement in the piston chamber. Depending on the design of the suction device, the piston can move, for example, from top to bottom or sideways. An intermediate section of the first channel can be arranged between the piston chamber and the motor or turbine. The first channel is a suction channel for the suction flow, wherein the first channel is preferably designed to take up a larger proportion of the suction flow and to direct it in the direction of the motor or turbine.the turbine, while a second channel is designed to take out a smaller portion of the suction flow and direct it in the direction of the motor or the turbine. According to the invention, it is preferred that the suction device comprises a second channel which is designed as a bypass channel, wherein the second channel is designed to bypass the piston and / or the piston chamber of the suction device. In this way, the suction of suction material, which according to the invention is preferably referred to as “suction operation”, can advantageously be maintained even during filter cleaning. It is a significant advantage that the invention can provide a suction device with a small, compact filter cleaning mechanism, in which it is nevertheless possible for the suction operation to be maintained during filter cleaning through the second channel of the suction device.Tests have shown that the achieved filter cleaning effect is very good. Within the meaning of the invention, it is preferred that the phrases "the second channel is designed as a bypass channel" and "the second channel bypasses the piston or piston chamber of the suction device" be used synonymously in the context of the present application. This preferably means that the second channel does not run through the piston chamber. In particular, there should be no fluidic connection between the piston chamber and the second channel. Rather, the second channel can be configured to connect the filter of the suction device to the first channel, the intermediate section, or an anteroom of the motor of the suction device.

[0017] According to the invention, the size of the cross-sectional area of ​​the second channel is in a range of 1-25%, preferably in a range of 2-15%, and most preferably in a range of 3-10% of the cross-sectional area of ​​a motor inlet of the suction device, the motor inlet delimiting the first channel on the turbine side. Preferably, the cross-section of the second channel can be much smaller than the cross-section of the first channel, measured at the motor inlet, i.e., at the transition from the first channel to the motor of the suction device. In a particularly preferred embodiment of the invention, the cross-section of the bypass channel can be between 3 and 10% of the cross-section of the first channel in the region of the motor inlet.This size ratio of the cross-sections of the channels has proven to be particularly advantageous if the invention is intended to maintain effective suction operation during filter cleaning, but at the same time also to provide effective filter cleaning.

[0018] According to the invention, it is preferred that the first channel is delimited on the engine side by an engine inlet, wherein the engine inlet has a cross-sectional area. The first channel, which according to the invention is preferably also referred to as the "suction channel", preferably begins at the turbine, wherein the transition between the turbine and the first channel is preferably referred to as the engine inlet. An intermediate section of the suction channel can be arranged between the turbine and the piston chamber. This intermediate section can, for example, have a tapered cross-section. According to the invention, this preferably means that the cross-section of the intermediate section at the engine inlet is larger than in the region in which the intermediate section opens into the piston chamber of the suction device. According to the invention, this opening region can preferably be referred to as the engine opening of the first channel or the piston chamber.In other words, the intermediate section of the first channel is delimited on the turbine or engine side by an engine inlet and on the piston chamber side by the engine opening. The first channel preferably leads through the piston chamber, with the filter and, if applicable, the collection container for the suction material being connected to the piston chamber. It should be noted that this description of the first channel is in the opposite flow direction of the suction flow. In the suction direction, the air flow laden with suction material is sucked into the suction device via a suction inlet and initially guided through the collection container, where most of the suction material is separated. The air flow is then sucked through the filter in suction mode, where the air flow is further cleaned. The air flow is then guided through the piston chamber in the direction of the turbine, with a gap being formed between the piston chamber or engine opening on the one side and the turbine orAn intermediate section of the first channel can be arranged on the other side of the engine inlet. From the perspective of the engine opening, the cross-section of the intermediate section can increase toward the turbine or toward the engine inlet, so that the cross-section of the intermediate section is larger in the area of ​​the engine inlet than in the area of ​​the engine opening.

[0019] According to the invention, it is preferred that the cross-section or cross-sectional area of ​​the second channel is substantially constant over its length. In other words, the bypass channel has substantially the same or a similar cross-section at different points. The second channel can, for example, begin in the intermediate section of the first channel or - depending on the point of view - open into it. In particular, the second channel can run through the suction device in such a way that the bypass channel bypasses the piston or the piston chamber. According to the invention, the term "bypass" preferably means that the second or bypass channel does not pass through the piston chamber, but rather avoids it. According to the invention, however, it can also be preferred that there is no fixed spatial separation between the piston chamber and the second channel.According to the invention, it is preferred that there is no direct fluidic connection between the piston chamber and the second channel of the suction device. However, it can also be preferred that there is a limited, minimal fluidic connection between the second channel and the piston chamber. While a first end of the bypass channel can open into the intermediate section of the first channel, a second end of the bypass channel preferably opens into the filter of the suction device. In other words, the second channel connects the first suction channel to the filter, wherein according to the invention it is particularly preferred that the second channel connects the intermediate section of the first channel to the filter. This means that when the suction device is in suction mode, a small part of the air flow can flow through the bypass channel, while a larger part of the air flow can flow through the first channel.

[0020] According to the invention, it is preferred that at least one contact surface be provided in the piston chamber, which limits the movement of the piston from the suction operation position to the filter cleaning position. If the movement of the piston from the suction operation position to the filter cleaning position represents a movement from top to bottom, the at least one contact surface can be arranged, for example, on an underside of the piston chamber, so that the piston is decelerated by the contact surface when the piston moves from the suction operation position to the filter cleaning position to perform the filter cleaning.

[0021] According to the invention, it is preferred that the piston chamber has a compression zone, wherein the compression zone extends between the at least one contact surface and an engine opening of the piston chamber. According to the invention, it is particularly preferred that the compression zone extends between the at least one contact surface and a lower edge of an engine opening of the piston chamber. The compression or air volume that can be compressed by the movement of the piston is present in the compression zone. This compression or compression of the compression volume preferably takes place in a so-called compression phase of the filter cleaning process, which preferably begins with the piston moving from the suction operation position to the filter cleaning position. During this movement, the piston sweeps over the engine opening of the piston chamber and closes it.This cuts off most of the suction flow from the turbine, causing it to come to a complete standstill. By providing the second channel, which is not currently closed by the movement of the piston, the suction operation can continue even when the first channel is closed. As a result, the suction operation is so minimally restricted by the piston closing the motor opening or its movement that the suction operation can continue almost unnoticed by the user during filter cleaning.

[0022] When the piston moves from the suction operation position to the filter cleaning position and closes the motor opening between the first channel and the piston chamber, the suction operation through the first channel is interrupted. However, the piston does not end its movement after sweeping over and closing the motor opening, but continues its movement in the direction of the filter. This movement is preferably very rapid or sudden, so that the air in the compression zone is compressed by the piston movement. The continued piston movement pushes this compressed air through the filter of the suction device, this process being preferably referred to as a "shock" in the sense of the invention. This shock causes a backwash of the filter, i.e. an air flow through the filter in a direction that is opposite to the direction of the suction flow in suction operation.In addition, the impact causes a mechanical vibration of the filter. This dual effect of the impact allows for particularly effective filter cleaning, even though only one piston and a very small amount of backflushing air are used. The continuation of the piston movement beyond the motor opening occurs over a length h, which is preferably referred to as the "height of the compression zone". In the sense of the invention, it is preferred that the piston moves a length L during the movement from the suction operation position to the filter cleaning position, wherein the length L corresponds at least to the sum of the diameter of the motor opening and the height of the compression zone.

[0023] It is preferred in the sense of the invention that a height h of the compression zone [in mm] is in a range of less than (1 / 1,500-mm) of a cross-sectional area of ​​the piston [in mm 2] . Preferably, the height of the compression zone is measured between the at least one contact surface and the lower edge of the engine opening of the piston chamber (see figures). It was completely surprising that with such a low height of the compression zone and with only a single piston, such a strong pressure surge can be generated that effective filter cleaning is possible. In one embodiment of the invention, the height of the compression zone can, for example, be in a range of 2 - 17 mm, while the cross-sectional area of ​​the piston ("piston area") is, for example, 250 cm 2 or 25,000 mm 2 Thus, the height h of the compression zone corresponds to less than 1 / 1 ,500 of the piston area, taking into account the corresponding or the same units of measurement. In this comparison, the height h of the compression zone in the unit mm is compared with the piston area in the unit mm. 2 compared with each other.

[0024] In a second aspect, the invention relates to a method for operating a proposed suction device. The terms, definitions, and technical advantages introduced for the suction device preferably apply analogously to the operating method for the suction device. The operating method is characterized by the following method steps: a) providing the suction device and operating the suction device in a suction mode, b) carrying out a filter cleaning process by moving a piston from a suction mode position to a filter cleaning position, wherein this movement closes a first channel so that air between the piston and a filter is compressed such that a burst of compressed air is forced through the filter and the filter is thus cleaned.

[0025] In other words, in addition to providing the suction device and operating it in suction mode, the method also comprises moving the piston from a suction mode position to a filter cleaning position, wherein this movement of the piston initiates filter cleaning. The movement of the piston closes the first channel, which receives the majority of the suction flow during suction mode, so that the suction drive can be maintained by a second channel during filter cleaning. The filter cleaning process preferably begins with closing the motor opening of the piston chamber, thereby closing the first channel. This is preferably followed by the compression phase, during which the air in the compression volume of the piston chamber is compressed and pushed through the filter.After the filter cleaning process is complete, the piston returns to its original position, which preferably corresponds to the suction mode position of the piston. It was completely surprising that the invention can maintain effective suction mode during filter cleaning while simultaneously providing effective filter cleaning.

[0026] According to the invention, during suction operation, a larger portion of the suction flow flows through the first channel and a smaller portion of the suction flow flows through a second channel. Preferably, the second channel is designed as a bypass channel, wherein the second channel is particularly configured to bypass or avoid the piston chamber of the suction device.

[0027] During suction operation of the vacuum cleaner, the suction flow preferably flows through the first and a second channel, with a larger proportion of the suction flow flowing through the wider, i.e. larger, first channel, while a smaller proportion of the suction flow flows through the second channel, which preferably has a smaller cross-section than the first channel. The suction operation of the vacuum cleaner therefore differs from filter cleaning (“filter cleaning process”) preferably in that during suction operation the suction flow flows through the suction channel and the bypass channel, whereas during a filter cleaning process the suction flow only flows through the second channel, i.e. the bypass channel. This switching off of the first channel, i.e. the suction channel, is brought about in particular by the movement of one piston, which can move back and forth in a piston chamber of the vacuum cleaner.Depending on the design of the piston chamber, this can be an up-down (i.e. up-down) or sideways movement of the piston. The piston is preferably designed to perform a linear movement in order to start or carry out a filter cleaning process. The movement of the piston can close the first channel so that there is no longer any fluid connection between the motor of the suction device and the filter. To do this, the piston can stroke over the motor opening of the piston chamber, thereby closing the motor opening and thus the first channel. In this way, there is no longer any suction flow flowing through the first channel. The suction operation of the suction device is maintained during a filter cleaning process, i.e. in the filter cleaning phase, by the second channel, which preferably bypasses the piston chamber. The second channel forms a bypass ora targeted bypassing of the piston chamber of the suction device. This is advantageously made possible by the second channel being guided past the piston chamber, for example, on the outside.

[0028] The statement that the suction operation is maintained by the bypass channel does not contradict the statement that the suction flow flows through the first and a second channel during the suction operation of the vacuum cleaner, while during a filter cleaning process the suction flow flows only through the second channel, i.e., the bypass channel. The suction operation or suction phase of the vacuum cleaner is preferably characterized in that the vacuum cleaner only sucks, but the filter is not cleaned. The filter cleaning phase of the vacuum cleaner is preferably characterized in that the filter of the vacuum cleaner is cleaned while the suction operation of the vacuum cleaner is maintained through the second or bypass channel—in a kind of special operation. This maintenance of the suction operation during the implementation of a filter cleaning process represents a particular advantage of the invention.

[0029] According to the invention, it is preferred that the piston is returned pneumatically and / or mechanically to a starting position. The piston is returned to its starting position, in particular after the filter cleaning process has been completed. The starting position preferably corresponds to the suction operation position of the piston. The piston can be returned in various ways. For example, the piston can be returned mechanically. In an alternative embodiment of the invention, the piston can be returned pneumatically to its starting position. The return of the piston to its starting position represents, in particular, a countermovement to the movement with which the piston is moved from the suction operation position to the filter cleaning position.In other words, the piston is returned from the filter cleaning position to the suction operation position, with the suction operation position representing the starting position of the piston.

[0030] Further advantages emerge from the following description of the figures. The figures, the description, and the claims contain numerous features in combination. Those skilled in the art will also expediently consider the features individually and combine them into further meaningful combinations. In the figures, identical and similar components are numbered with the same reference numerals. They show:

[0031] Fig. 1 View of a preferred embodiment of the suction device in suction mode

[0032] Fig. 2 View of a preferred embodiment of the suction device at the beginning of the filter cleaning Fig. 3 View of a preferred embodiment of the suction device during the filter cleaning

[0033] Implementation examples and figure descriptions:

[0034] Figure 1 shows a preferred embodiment of the suction device 10 in suction mode. The suction device 10 can be designed as a vacuum cleaner or as an industrial vacuum cleaner and includes a motor 16 that generates an air or suction flow 18. The suction device 10 can consist of an upper part (suction head) and a lower part, wherein the lower part of the suction device 10 can include a collection container 12 for suction material 14, such as dust. An opening (not shown) can be provided in the suction device 10, which can be connected to a suction hose (not shown). The suction hose can be connected to a floor nozzle or a power tool (not shown) so that the suction device 10 can be used to clean a floor or vacuum up dust generated during work with the power tool. The dust 14 is sucked into the suction device 10 by means of the suction flow 18, whereby a large portion of the dust 14 can be deposited in the collection container 12.The suction flow 18 is then passed through a filter 20 within the vacuum cleaner 10, where the suction flow 18 is further cleaned by the filter 20. As the suction flow 18 passes through the filter 20, individual dust particles 14 may become trapped in the filter, so that these dust particles 14 are filtered out of the air flow 18. In the event of heavy dust exposure, the filter 20 of the vacuum cleaner 10 may become clogged, which may reduce the performance of the vacuum cleaner 10 or its suction power. In the field of industrial vacuum cleaners, it is therefore known to regularly clean the filter(s) 20 of the vacuum cleaner 10. In the context of the present invention, it is proposed that a piston 22 be moved toward the filter 20. This movement of the piston 22 is indicated in Figure 2 by an arrow with the letter "v".The piston 22 can move in particular linearly in a piston chamber 26 and have a piston surface 42 with a specific cross-sectional area on its underside. If the piston 22 moves, for example, from top to bottom in the piston chamber 26, the air in the compression zone 38 can be pressed together or compressed in a compression zone (see Fig. 2). This is achieved in particular because the filter 20 initially represents a resistance for the air in the compression zone 38, whereby this resistance can, however, be overcome by the downward movement of the piston 22 and the increase in the pressure on the air. The continued movement of the piston 22 can force the compressed air through the filter 20 in a pulsed manner. This advantageously achieves two effects: firstly, a so-called backflushing of the filter 20 occurs, i.e. air is passed through the filter 20 in the opposite direction of suction.On the other hand, the passage of the impact of compressed air causes a mechanical vibration of the filter 20. Both effects of the piston movement lead to an effective cleaning of the filter 20, whereby any adhering filter cake can be detached from the filter 20 and falls into the collecting container 12.

[0035] However, the invention not only provides effective filter cleaning. By arranging a first channel 24 and a second channel 28, as described below, the suction operation of the suction device 10 can be maintained even while filter cleaning is being carried out. The first channel 24, which is preferably also referred to as the "suction channel" within the meaning of the invention, is designed to receive a larger portion 18a of the suction flow 18. The second channel 28, which is preferably also referred to as the "bypass channel" within the meaning of the invention, is designed to receive a smaller portion 18b of the suction flow 18. The larger portion 18a of the suction flow 18 is shown in Figure 1 with a thicker dashed line than the smaller portion 18b of the suction flow 18. The smaller portion 18b and the larger portion 18a together form the suction flow 18, as indicated by the curly brackets in Figure 1.The larger portion 18a of the suction flow 18 is guided in the first channel 24 by the filter 20 in the direction of the motor 16 or the turbine (not shown) of the suction device 10. In suction mode, the suction flow 18a passes through the piston chamber 26 and leaves the piston chamber 26 through a motor opening 40, wherein the motor opening 40 has a diameter d. An intermediate section 44 of the first channel 24 can be arranged between the piston chamber 26 and the motor 16 (see Figure 3), through which the larger portion 18a of the suction flow 18 is guided. At the end of the intermediate section 44 there is a motor inlet 34 which has a cross-sectional area 32. In other words, the intermediate section 44 can be delimited on the turbine side by the motor inlet 34, while the intermediate section 44 on the piston chamber 26 side is delimited by the motor opening 40.Thus, the intermediate section 44 extends between the engine opening 40 on one side and the engine inlet 34 on the other side. The intermediate section 44 can have a tapered profile, wherein a cross-section 32 of the engine inlet 34 can be larger than a cross-sectional area of ​​the engine opening 40, wherein the engine opening 40 has a diameter d. In the sense of the invention, this preferably means that the cross-section of the first channel 24 or its intermediate section 44 in the region of the engine inlet 34 is larger than a cross-section of the first channel 24 or its intermediate section 44 in the region of the engine opening 40, wherein the engine opening 40 marks or forms the transition between the intermediate section 44 or the engine 16 on one side and the piston chamber 26 on the other side.It has proven particularly advantageous if the cross-sectional area 30 of the second channel 28 is significantly smaller than the cross-sectional area 32 of the engine inlet 34. Preferably, the size of the cross-sectional area 30 of the second channel 28 can be in a range of 3 - 10% of a cross-sectional area 32 of the engine inlet 34. If the cross-sectional area 32 of the engine inlet 34 is, for example, 100 cm. 2 the cross-sectional area 30 of the second channel 28 can be, for example, in a range between 3 and 10 cm 2It has been shown that such a ratio of the cross-sectional areas allows for a good distribution between the larger part 18a and the smaller part 18b of the suction flow 18. This allows, on the one hand, effective backwashing of the filter 20 for the purpose of filter cleaning to be achieved, and, on the other hand, the suction operation of the suction device 10 via the second channel 28 can be maintained to such an extent that further suction material 14 can be sucked into the suction device 10 with sufficient suction force.

[0036] In addition to the first channel 24, the suction device 10 can have a second channel 28, which extends, for example, between the intermediate section 44 and the filter 20. The second channel 28 is designed in particular as a bypass channel in order to bypass the piston chamber 26 and to direct a smaller part of the suction flow 18b past the piston chamber 26 from the filter 20 to the turbine or to the motor 16 of the suction device 10. By providing the second channel 28, the suction operation can be maintained even when the filter 20 of the suction device 10 is being cleaned. The first channel 24 is preferably closed during filter cleaning, specifically by the piston 22, which moves in the piston chamber 26 from a suction operation position to a filter cleaning position in order to start filter cleaning.In other words, the piston 22 is configured to start filter cleaning by moving the piston 22 from a suction operation position to a filter cleaning position. To do this, the piston 22 can, for example, move from a higher suction operation position to a lower filter cleaning position, i.e., perform a movement from top to bottom, following the force of gravity. Figure 1 shows, in particular, a suction device 10 in which the piston 22 is in the suction operation position in the piston chamber 26. In the exemplary embodiment of the invention shown in Figure 1, this means that the piston 22 is arranged in an upper region of the piston chamber 26 during suction operation.The larger part 18a of the suction flow 18 can only flow in the suction mode position of the piston 22, while the smaller part 18b of the suction flow 18 can flow in the suction mode position (Figure 1), as well as in the intermediate position (Figure 2), and in the filter cleaning position (Figure 3) of the piston 22. The flow of the larger part 18a of the suction flow 18 through the first channel 24 is interrupted in particular by the downward movement of the piston 22, which initiates the filter cleaning. Preferably, in the context of the present invention, only a much smaller suction flow 18 flows during filter cleaning compared to the suction mode.

[0037] When the piston 22 moves from the suction operation position to the filter cleaning position, the piston 22 preferably sweeps over the motor opening 40 of the piston chamber 26, thereby closing the motor opening 40. In this way, the suction flow 18a through the first channel 24 stops, while the suction flow 18b can continue to flow through the second channel 28. In the exemplary embodiments of the invention illustrated in the figures, the second channel 28 has a substantially constant diameter over its length. As a result, the cross-sectional area 30 of the second channel 28 is also substantially constant over its length.

[0038] The situation in which the piston 22 moves downwards and closes the motor opening 40 of the piston chamber 26 is shown in Figure 2. The (downward) movement of the piston 22 is symbolized in particular by the downward-pointing arrow, which is marked with the letter "v". Figure 2 thus shows an intermediate position of the piston 22, which is located between the suction operation position and the filter cleaning position. In this intermediate position, the compression zone 38, which comprises a compression volume, is located below the piston 22 or the piston surface 42. The compression volume is formed by the air located in this lower region of the piston chamber 26. In other words, a lower region of the piston chamber 26, which is located between the filter 20 and the piston 22 orthe piston surface 42, form the compression zone 38, which comprises a specific amount of air that can be compressed by the continued movement of the piston 22 - in the embodiment shown in Figure 2: in a downward spatial direction. The air in the compression zone 38 is thereby compressed. The spatial directions O (upward) and U (downward) are symbolized in Figure 2 by the double arrow, with the tips of the double arrow pointing in the upward spatial direction (O) or in the downward spatial direction (U).

[0039] The compression zone 38 has a height h, wherein the height h can, for example, correspond to the distance between the at least one contact surface 36 and the lower edge of the engine opening 40. In other words, the compression zone 38 can extend in the top-bottom orientation between the engine opening 40 (top) and the at least one contact surface 36 (bottom). It is preferred within the meaning of the invention that the height h of the compression zone 38 lies in a range of less than 1 / 1,500 mm of a cross-sectional area 42 of the piston 22. The height h of the compression zone 38 is given in millimeters [mm], while the cross-sectional area 42 of the piston 22 is given in square millimeters [mm 2 ] The optimum height h of the compression zone 38 in the unit mm can thus be determined by dividing the area of ​​the piston (in the unit mm 2) is multiplied by the factor (1 / 1,500 mm). The movement of the piston 22, for example, has a length L, which is shown in Figure 1. The length L of the movement of the piston 22 can correspond to the sum of the height h of the compression zone 38 and the diameter d of the engine opening 40, i.e. L = h + d.

[0040] As the piston 22 moves further downward in the piston chamber 26, toward the filter 22, the piston 22 pushes the compressed air ahead of it. The compressed air creates a blast of compressed air that can move through the filter 20 and thus clean the filter 20. The blast of compressed air or compressed air pulse acts in two ways: firstly, the blast of compressed air backwashes the filter 20, so that any filter cake is loosened and can fall into the collection container 12 of the suction device 10. Secondly, the blast of compressed air can cause a mechanical vibration of the filter 20, which can also cause any adhering filter cake to detach from the filter 20.

[0041] The movement of the piston 22 ends when the piston 22 strikes the at least one contact surface 36 and thereby comes to a stop. The piston 22 has then reached its filter cleaning position. The filter cleaning position of the piston 22 is shown in Figure 3.

[0042] The second channel 28 is advantageously not closed by the downward movement of the piston 22. This is ensured by the support surfaces 36, which can be provided, for example, above the filter 20 in the piston chamber 26. The support or abutment surfaces 36 slow the movement of the piston 22 so that the piston 22 comes to rest on the support surfaces 36. In this filter cleaning position of the piston 22, only the smaller part 18b of the suction flow 18 can flow, whereby the suction operation of the suction device 10 can be maintained via this smaller part 18b of the suction flow 18 and the suction device 10 can continue to be used to suck in suction material 14 even during filter cleaning. After filter cleaning is complete, the piston 22 can be returned pneumatically and / or mechanically to its starting position, whereby the starting position preferably corresponds to the suction operation position of the piston 22.

[0043] Figure 2 shows a possible embodiment of the suction device 10 at the beginning of the filter cleaning process, with the piston 22 in an intermediate position, while Figure 3 shows a possible embodiment of the suction device 10 during the filter cleaning process, with the piston 22 in a filter cleaning position.

[0044] 10 suction device

[0045] 12 collection containers

[0046] 14 Suction material

[0047] 16 Engine

[0048] 18 Suction flow

[0049] 18a larger part of the suction flow

[0050] 18b smaller part of the suction flow

[0051] 20 filters

[0052] 22 pistons

[0053] 24 first channel

[0054] 26 Piston chamber

[0055] 28 second channel

[0056] 30 Cross-sectional area of ​​the second channel

[0057] 32 Cross-sectional area of ​​the engine inlet

[0058] 34 Engine intake

[0059] 36 contact surface

[0060] 38 compression zone

[0061] 40 Engine opening of the piston chamber

[0062] 42 Cross-sectional area of ​​the piston

[0063] 44 Intermediate section h Height of the compression zone d Diameter of the engine opening L Length of the piston movement v Movement of the piston

[0064] O Spatial direction upwards

[0065] U spatial direction downwards

Claims

Patent claims 1. Suction device (10) with a collecting container (12) for receiving suction material (14), with a filter (20) for cleaning the suction flow (18) and with a motor (16) for driving a turbine, wherein the turbine is designed to generate a vacuum and thus a suction flow (18) for sucking in the suction material (14), characterized in that the suction device (10) has a piston (22) which is designed to be movable in order to carry out filter cleaning and which, in a suction operation position, opens a first channel (24) and closes the first channel (24) by moving into a filter cleaning position, wherein air between the piston (22) and the filter (20) is compressed in such a way that a pulse of compressed air is forced through the filter (20) and the filter (20) is cleaned in this way.

2. Suction device (10) according to claim 1, characterized in that the first channel (24) is arranged between the motor (16) of the suction device (10) and the filter (20), wherein the first channel (24) is designed as a suction channel and runs at least in sections through a piston chamber (26) of the suction device (10).

3. Suction device (10) according to claim 2, characterized in that the suction device (10) comprises a second channel (28) which is designed as a bypass channel, wherein the second channel (28) is designed to bypass the piston (22) and / or the piston chamber (26) of the suction device (10).

4. Suction device (10) according to claim 2 or 3, characterized in that the suction operation is maintained during filter cleaning through the second channel (28).

5. Suction device (10) according to one of claims 2 to 4, characterized in that a size of a cross-sectional area (30) of the second channel (28) in a range of 1 - 25%, preferably in a range of 2 - 15% and most preferably in a range of 3 - 10% of a cross-sectional area (32) of an engine inlet (34).

6. Suction device (10) according to claim 5, characterized in that the motor inlet (34) delimits the first channel (24) on the turbine side.

7. Suction device (10) according to one of the preceding claims, characterized in that at least one contact surface (36) is provided in the piston chamber (26), which limits the movement of the piston (22) from the suction operation position into the filter cleaning position.

8. Suction device (10) according to claim 7, characterized in that the piston chamber (26) has a compression zone (38), wherein the compression zone (38) extends between the at least one contact surface (36) and a motor opening (40) of the piston chamber (26).

9. Suction device (10) according to claim 8, characterized in that a height h of the compression zone (38) is in a range of less than (1 / 1,500 mm) of a cross-sectional area (42) of the piston (22).

10. Suction device (10) according to one of the preceding claims, characterized in that a length of movement of the piston (22) is greater than or equal to a sum of the height h of the compression zone (38) and a diameter d of the motor opening (40).

11. Suction device (10) according to one of the preceding claims, characterized in that the suction device (10) has an intermediate section (44) which is arranged between the motor (16) and the piston chamber (26), wherein the intermediate section (44) has a Partial section of the first channel (24).

12. Method for operating a suction device (10) according to one of the preceding claims, characterized by the following method steps: a) providing the suction device (10) and operating the suction device (10) in a suction mode, b) carrying out a filter cleaning process by moving a piston (22) from a suction mode position into a filter cleaning position, wherein this movement closes a first channel (24) so that air between the piston (22) and a filter (20) is compressed such that a burst of compressed air is forced through the filter (20) and the filter (20) is cleaned in this way.

13. Method according to claim 12, characterized in that in suction operation a larger portion of a suction flow (18) flows through the first channel (24) and a smaller portion of the suction flow (18) flows through a second channel (28), 14. Method according to claim 13, characterized in that the suction operation is maintained during the filter cleaning process through the second channel (28).

15. Method according to one of claims 12 to 14, characterized in that the piston (22) is returned pneumatically and / or mechanically to an initial position.

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