NL2009662C2 - PARTICLE COLLECTION DEVICE AND THEREFORE DEVICE DEVICE. - Google Patents

Description

PARTICLE COLLECTION DEVICE AND THEREFORE DEVICE DEVICE

The invention relates to a device 5 for collecting particles, in particular material and dust particles released from a workpiece by machining, and to a machining device provided with such a particle collection device.

When material 10 is processed with a machining device and particles are removed therefrom, for example by means of planing, sanding, grinding, sawing, etc., it is customary to extract these particles and collect them in a particle collection device.

There are three main categories of dust collection: 15 cheaper models usually collect dust particles in a bag, while more professional models are equipped with an easy-to-empty dust box or a connection for a vacuum cleaner hose.

When a particle collection device fills with dust particles, the dust will accumulate in the collection device and continue to compress until the dust accumulates in the channels of the machining device.

It is desirable for a user to notice the fullness of a particle collection device early so that accumulation of dust particles in the channels of the machining device itself can be prevented by timely emptying of the particle collection device.

The invention now has for its object to provide a particle collection device of the type described above, wherein the disadvantages mentioned do not occur, or at least to a lesser extent. In particular, it is an object of the invention to make a user aware of the fullness of a particle collection device in good time.

2

Said object has been achieved with the device for collecting particles, in particular material and dust particles detached from a workpiece by machining, comprising: a housing with at least one front wall provided with an inlet opening through which the particles enter a volume enclosed by the housing can be inserted; - a collecting bag arranged in the housing which is connected to the inlet opening with a filling opening and which is gas-permeable at least to some extent; - wherein the housing comprises a wall provided with a passage opening through which the collecting bag extends at least in a state filled with collected particles; - wherein the circumference of the collection bag at least at the location of the passage opening in the wall is larger than the circumference of this passage opening, wherein the collection bag: - in a substantially unfilled state allows at least gas passage through the passage opening; and in a state filled with collected particles at a predetermined degree of filling the passage opening closes at least largely for gas passage; - closing the gas passage through the passage opening through the collection bag causes a pressure difference in a compartment of the housing; - wherein at least one gas pressure detection device is provided which is adapted to detect this pressure difference and to indicate via at least one degree of filling indicator that the predetermined degree of filling of the collecting bag has been achieved.

The collection bag is gas permeable to some extent, making it act as a kind of filter: material and dust particles remain in the collection bag, and the gas escapes through the wall of the bag. This gas will spread within the housing of the particle collection device and cause a pressure build-up there which is detectable with the gas pressure detection device.

According to a preferred embodiment, the predetermined degree of filling of the collecting bag, the degree of filling indicating that the predetermined degree of filling of the collecting bag is at least determined by the location where the wall provided with the passage opening is arranged around the collecting bag.

The location where the wall provided with the passage opening is arranged around the collection bag determines at which degree of filling the transition takes place from the first state, wherein the collection bag allows gas passage through the passage opening to the second state, wherein the collection bag at least largely closes the passage opening for gas passage.

In this second state, closing the gas passage through the passage opening through the collection bag causes a pressure difference in a compartment of the housing, to which the gas pressure detection element will respond.

The place where the wall provided with the passage opening is arranged around the collection bag is preferably located between the filling opening of the collection bag and halfway along its length. The designer can choose the exact placement in this range depending on the degree of filling of the collection bag, whereby a change to an indication of a 'full' 1 condition of the collection bag is desired.

According to a further preferred embodiment, the compartment in which the pressure difference is created by closing the passage opening with the collection bag is a first compartment which is at least bounded by the front wall and the wall provided with the passage opening. In this embodiment, the pressure difference arises in the front compartment that borders on the front wall, while optionally a rear compartment can be provided. The rear compartment is in that case separated from the front compartment by the wall provided with the passage opening.

Although it is conceivable that the front wall is curved and connects directly to the rear wall, one or more side walls will normally contribute to the boundary of the first compartment.

According to a still further preferred embodiment, the wall provided with the front opening is the rear wall of the housing. In this embodiment there is only one compartment. This one compartment is located between the front wall and the wall provided with the passage opening. An embodiment with only one compartment has the advantage that the housing can be of a more compact design, and can therefore also be made lighter. Moreover, in a filled state, the collection bag extends beyond the rear wall of the housing, making it easily accessible. The protruding end of the collection bag can for instance be squeezed together, which can facilitate the emptying of the collection bag - whereby it has to be pulled through the passage opening -.

According to a still further preferred embodiment, the wall provided with the passage opening is an intermediate wall arranged in the housing which divides the volume enclosed by the housing into a first, front compartment and a second, rear compartment. An embodiment with both a front and a rear compartment has the advantage that the collection bag is completely protected by the housing. The collection bag can also be completely hidden from view by the housing.

According to yet a further preferred embodiment, the gas pressure detection element comprises a detection element housing, a piston element displaceably arranged in the detection element housing, and wherein the piston element is biased by means of a spring such that the piston element, only when the force exerted thereon by a pressure difference exerts the biasing force of the spring exceeded, moved 10 and operates a fill level indicator.

An incorrect indication can occur in some versions when the machining device is switched off. If the machining device is switched off, there will be no pressure build-up. The degree of filling indicator can then indicate in an embodiment in which it responds to the loss of gas pressure that the collection bag is full, while the gas pressure has not fallen away by closing the passage opening with the collection bag, but only because the machining device 20 is switched off .

In order to prevent an incorrect indication, according to a still further preferred embodiment, the gas pressure detection device is arranged in the first compartment and it is arranged to move the filling degree indicator to a full-indication position when there is a pressure increase in the first compartment.

In this embodiment, the spring introduces a threshold force which initially maintains the degree of filling indicator in a neutral position. The advantage of this neutral position when the machine is off is that it is prevented that a user is misinformed.

6

When the machining device is in operation and the collection bag reaches a certain degree of filling, the collection bag will at least largely limit the gas passage through the passage opening. This creates a pressure difference in the compartment of the housing where the gas pressure detection element is arranged. The gas pressure detector will then move the degree of filling indicator to a full indication position.

According to a still further preferred embodiment 10, the gas pressure detection element is arranged in the second compartment and is arranged to move to a full-indication position in the event of a pressure reduction in the second compartment.

In this embodiment the compartment in which the pressure difference is created by closing the passage opening with the collecting bag is a second compartment which is at least limited by the rear wall of the housing and the wall provided with the passage opening. When the collection bag fills and closes the passage opening 20, gas will hardly be supplied to the second compartment, i.e. the rear compartment. The passage opening is closed, and because the collecting bag is filled in the rear part, hardly any gas will also get through the pores of the collecting bag into the rear compartment.

The gas pressure in the rear compartment thereby drops, as a result of which the force exerted on the filling degree indicator by the spring of the gas pressure detection member will be greater than the force exerted by the gas pressure on the piston of the filling degree indicator. As a result, the degree of filling indicator is moved to a position that is associated with a 'full' state of the collection bag.

7

By arranging the gas pressure detection element in the second compartment, it is in a position that is intuitive and clearly visible to the user.

According to a still further preferred embodiment, the gas pressure detection element is arranged in the second compartment and this gas pressure detection element is in gas communication with the first compartment via a connecting channel, wherein the gas pressure detection element is adapted to change the filling degree indicator to a full indication position when there is a pressure increase in the first compartment. move.

By arranging the gas pressure detection element in the second compartment, it is in a position that is intuitive and clearly visible to the user. On the other hand, the gas pressure detector is in gas communication with the first compartment via a connecting channel, which offers the advantage that the degree of filling indicator will again indicate a neutral filling level if the machining machine is switched off. This prevents a user 20 from being misinformed, as explained in detail above.

According to a still further preferred embodiment, a stirring rod is arranged in the collecting bag which extends over substantially the entire length of the collecting bag to near the filling opening thereof. Because the particles collected in the collecting bag compress to some extent, the collecting bag will be constricted through the passage opening into the wall provided with the passage opening. In addition to the desired gas-tight closure of the passage opening, however, this has the disadvantage that the collection bag closes very tightly in the passage opening, and will therefore give some resistance when, in order to be emptied, it passes through the passage opening in the direction of the filling opening must be pulled from the 8 collection bag. By stirring with a stir bar in the collection bag filled with particles, these particles are loosened. The tension at the location of the constriction at the passage opening can thereby be reduced, as a result of which the collection bag can be pulled through the passage opening. By turning the collection bag inside out, it can then be emptied. The collection bag can then be pushed back into the housing via the stir bar.

According to a still further preferred embodiment, the gas pressure detection element is provided with an overpressure discharge opening. This overpressure discharge opening guarantees a continuous discharge of gas, whereby the air flow that transports the particles from the transport device to the particle collection device 15 remains in motion.

According to a still further preferred embodiment, a whistle element is arranged in the overpressure discharge opening, which whistle generates a whistle sound when passing gas. In this way the user is informed in addition to a visual indication 20 also acoustically that the collecting bag has reached a predetermined degree of filling.

The invention further relates to a machining device, in particular a sanding machine, comprising a particle collection device as described above.

In the following description, preferred embodiments of the present invention are further explained with reference to the drawing, in which:

Figure 1: a perspective view of a machining device with a particle collection device according to the invention;

Figures 2A and 2B: detailed perspective views of the particle collection device shown in Figure 1, wherein the degree of filling indicator is in an "empty" (Figure 2A) and a "full" (Figure 2B) state;

Figure 3: a perspective cross-section of the particle collection device shown in Figure 1; Figures 4 and 5: cross-sections of a first preferred embodiment with an "empty" (Figure 4) and "full" state of the collection bag;

Figures 6 and 7: cross-sections of a second preferred embodiment with an "empty" (Figure 4) and "full" state of the collection bag;

Figures 8 and 9 show cross-sections of the process of emptying the collection bag of a particle collection device according to figures 6 and 7;

Figure 10: a schematic representation of a third preferred embodiment of the invention, wherein the collection bag is 'empty';

Figures 11 and 12: cross-sections of two alternative embodiments of gas pressure detectors in the "empty" state shown in Figure 10; Figure 13: a schematic representation of a third preferred embodiment of the invention, wherein the collection bag is 'full';

Figures 14 and 15: cross sections of two alternative embodiments of gas pressure detectors in the "full" state shown in Figure 13;

Figures 16 and 17: schematic representations of a fourth preferred embodiment of the invention, wherein the collection bag is "empty" (Figure 16) and "full" (Figure 17);

Figure 18: a sectional view of a gas pressure detector in the 'empty' state shown in Figure 16; and 10

Figure 19: a cross-section of a gas pressure detector in the "full" state shown in Figure 17.

The machining device 60 shown in Figure 1 is a sanding machine which is provided with a particle collection device 1 in which material and dust particles released by sanding are collected. The particle collection device 1 has a housing 2 with side walls 6 and a rear wall 8. In the upper side of the housing 2, a gas pressure detection member 26 is arranged. This gas pressure detection device 26 has a detection device housing 27 in which a fill degree indicator 30 in the form of a button can be slidably moved between positions associated with a discrete filling condition of the collection bag: 'full' / 'empty' or 'full' / 'neutral'. Furthermore, a number of openings 42 are provided in the upper side of the housing 2, through which any overpressure in the housing 2 can flow away in a restrictive manner. As a result, the flow remains possible at all times, while the limited gas outflow through the openings 42 allows sufficient pressure build-up in the compartments 22, 24 of the housing 2 for controlling the gas pressure detector 26.

In the detailed views of figures 2A and 2B, the degree of filling indicator 30 is shown in an empty state with indication E (figure 2A) and in a full state with indication F (figure 2B). As will become apparent in the following - depending on the embodiment - an extended state is associated with an empty or neutral state of the particle collection device 1, or precisely with a full state of the particle collection device 1, as is shown for example in Fig. 7.

11

The perspective sectional view of figure 3 shows that the particle collection device 1 comprises a front wall 4, side walls 6 and a rear wall 8. Provided in the front wall 4 is an inlet opening 12 through which the particles discharged by the machining device 60 can be introduced into a volume 16 enclosed by the housing 2.

In the embodiment shown in Figure 3, the volume 16 enclosed by the housing is divided by an intermediate wall 10 into a first compartment 22 and a second compartment 24. The first compartment 22, or the front compartment, is bounded at the front by the front wall 4 and at the rear by the intermediate wall 10. The second compartment 24, or the rear compartment, is bounded by the intermediate wall 10 and the rear wall 8.

In the embodiment shown, the intermediate wall 10 is of double-walled design at the top so that it can close over the single-walled part of the intermediate wall 10 arranged at the bottom. As a result, the intermediate wall 10 can form a substantially gas-tight seal between the two compartments 22, 24.

The intermediate wall 10 is provided with a passage 14 through which the collection bag 18 extends from the first compartment 22 to the second compartment 24.

The collecting bag 18 is connected with its filling opening 20 to the inlet opening 12 which is arranged in the front wall 4 of the housing 2.

A gas pressure detection member 26 is provided in the second compartment 24, while openings 42 are provided in the first compartment 22 through which a possible excess pressure in the first compartment 22 can be discharged outside the housing 2. The openings 42 may, if desired, be provided with a valve which opens only when a certain pressure level is exceeded.

Furthermore, a stirring bar 40 is arranged in the collecting bag 18, which stirrer extends over substantially the entire length of the collecting bag 18, and is fixed on the inside of the bag 18 at the end of bag 18 situated near the filling opening 20. The other end of the stir bar 40 extends close to the filling opening 20.

In the embodiment 10 shown in Figs. 4 and 5, the gas pressure detecting member 26 is arranged in the second, rear compartment 24. When the particle collection device 1 is connected to a machining device 60 (not shown) and it is in operation, particles P will be introduced via the filling opening 20 into the collection bag 18, which will then fill with these collected particles. In the largely unfilled state of the collection bag 18, gas G will pass through the pores of the collection bag 18 into the compartments 22, 24 of the housing 16 (Figure 4).

Because the collecting bag 18 only partially closes the passage opening 14 arranged in the intermediate wall 10, the gas G will spread over both compartments 22, 24 of the housing 2 and press against the piston 28 of the gas pressure detection element 26, as a result of which this piston 28 has an outward exerted directed force on the degree of filling indicator 30. In the state shown in Fig. 4, the force exerted by gas pressure G on the piston 28 will exceed the pre-stressing force of the spring 32, whereby the degree of filling indicator 30 is moved outwards to a state associated with an 'empty' state of the collection bag 18.

Incidentally, it is noted that the filling degree indicator 30 switches in a substantially discrete manner from "empty" or "neutral" to "full." An 'empty' condition should therefore not be interpreted as a completely 'empty' collection bag 18, but as a 'sufficiently empty' collection bag 18 with which the user can continue working for a while.

When the collection bag 18 further fills with particles, it will close the passage opening 14 in the intermediate wall 10 and thus prevent gas flow from the first compartment 22 to the second compartment 24. It is also the case that the collection bag 18 itself will in any case be filled with dust particles in the rear part that is located in the second compartment 24. The gas stream that enters the collection bag will therefore only penetrate to a very limited extent into the rear part of the collection bag 18, and also no longer enter the rear compartment 24 via the pores of the collection bag 18. As a result, the gas pressure in the rear compartment 24 decreases such that the gas pressure exerted on the piston 28 is insufficient to counteract the biasing force of the spring 32. The degree of filling indicator 30 then moves by the spring force to a lower position which is associated with a 'full' state of the collecting bag 18.

A drawback to the embodiment shown in Figs. 4 and 5 is that the gas pressure detection device 26 moves the filling degree indicator 30 to a position associated with a 'full' state when there is insufficient gas pressure in the second compartment 24. Although this indication is correct with a machining device 60 in operation, there will also be no gas pressure in the rear compartment 24 when the machining device 60 is switched off. As a result, with a machining device switched off, it is also indicated that the collecting bag 18 is in a 'full' state, which therefore does not necessarily have to be the case.

14

In order to solve this drawback of the embodiment shown in Figs. 4 and 5, a further preferred embodiment is shown in Figs. 6 and 7, wherein the gas pressure detection device 26 uses the gas pressure in the first compartment 22 for detecting a "full" state of the collection bag 18. In order for a physical location of the gas pressure detector 26 in the rear, second compartment 24 of the housing 16 to be advantageous for the visibility of the degree of filling indicator 30, 10, the gas pressure detector 26 in the rear compartment is shown in the embodiment shown in FIGS. 24, while in gas communication with the first, front compartment 22 via a connecting channel 36.

When the collection bag 18 is in the substantially 'neutral' state shown in Figure 6, gas G can pass through the pores of the collection bag 18 into both compartments 22, 24 and the gas pressure can moreover be transmitted via the in the intermediate wall 10 spread through passage opening 14 over both compartments 22, 24. Via the openings 43 provided in the wall of the second compartment 24, the gas G can escape from the inner space 16 of the housing 2 to the environment outside the housing 2.

When the collecting bag 18 is filled with particles P, and the collecting bag 18 closes the passage opening 14 in the intermediate wall 10 substantially gas-tightly, the gas pressure in the rear compartment 24 will fall away. The pressure in the front compartment 22 will be able to increase even further because the collecting bag 18 in the front compartment 22 will still be partially unfilled, as a result of which gas G can get into the first compartment 22 via the pores of the collecting bag 18. The gas pressure detecting member 26 is in gas communication with the front compartment 22 via a connecting channel 36, which extends via a connecting channel passage opening 38 in the intermediate wall 10 into the first compartment 22. When the gas pressure in the front compartment 22 increases, it will the connecting channel 36 exerts pressure on the piston 28. When this pressure exerted on the piston 28 is accompanied by a force greater than the force exerted by the spring 32, the degree of filling indicator 30 will move outwards to a "full" state associated position are printed.

When the condition shown in Fig. 7 is turned off the machining device 60 (not shown), the gas pressure in the first compartment 22 will fall away and the spring force 32 will exceed the force exerted on the piston 28. In that case, the spring 32 will move the fill degree indicator 30 to the neutral position of the fill degree indicator 30 shown in Figure 6, even though the collection bag 18 is still in the "full" state shown in Figure 7.

When the collection bag 18 is filled with particles and needs to be emptied, the particle collection device 1 is removed from the machining device 60 (Figure 8).

It is noted that figures 8 and 9 relate to the embodiment of figures 6 and 7, which can be noted in that the degree of filling indicator 30 is in the downward 'neutral' state when the gas pressure is lost. Naturally, the emptying of, for example, a device 1 shown in Figs. 4 and 5 takes place in a corresponding manner, but in that case the filling degree indicator 30 would have been in an outwardly moved state, which could be incorrectly associated with a "void" state.

16

Before emptying the collection bag 18, a user can grasp the end of stirring bar 40 located near the filling opening 20 of the collection bag 20 and move it through the collection bag 18 in a movable manner.

As a result, the particles which are in a somewhat compressed state as a result of filling are released and the collecting bag 18 can be pulled more easily through the passage opening 14 in the intermediate wall.

Figure 9 shows how the collection bag 18 is pulled all the way toward an inside-out state to empty the collection bag 18.

The operation of the gas pressure detector 26 is explained in more detail with reference to Figures 10-15. When the collection bag 18 of the particle collection device 1 is substantially filled, gas G can get into the rear compartment 24. This occurs on the one hand via the pores of the collecting bag 18 and on the other hand via the passage opening 14. As already explained with reference to Fig. 4, a biasing force exerted by a spring 32 can be exceeded when the gas pressure exerted on a piston 28 is sufficiently large . The degree of filling indicator 30 will then be pushed outwards against the spring action 32 (Figures 4 and 11).

When the collection bag 18 fills up and closes the passage opening 18 and there is also virtually no gas pressure anymore in the rear compartment 24 via the pores of the collection bag, the gas pressure in the rear compartment 24 will fall away (figure 13). In that case, the gas pressure exerted on the piston 28 will generate too low a force to counteract the spring bias 32, as a result of which the spring 32 pulls the degree of filling indicator 17 into the retracted state shown in Figures 5 and 14.

An alternative embodiment in which the gas pressure detector 26 can be arranged in the rear compartment 24 without having to establish a gas connection with the front compartment 22 is shown in Figs. 12 and 15. The configuration of the gas pressure detector 26 is such that at the loss of gas pressure in the rear compartment 24 moves the fill degree indicator 30 to a neutral position. This embodiment therefore also displays a neutral state with the machining device 60 switched off, thereby preventing an incorrect display. In the embodiment shown in Figs. 11 and 14, with a machining device switched off, it can be erroneously displayed that the collecting bag 18 is in a 'full' state.

When the collecting bag 18 is in the largely unfilled state shown in Fig. 10, gas pressure will build up in the rear compartment 24 which acts on the surface of the piston 28 and thus exerts a force on the spring 32. Below the piston 28 is a compartment 29 which is connected to the environment outside the housing 25 via an overpressure discharge opening 44 and an overpressure discharge channel 46. If the machining device 60 is switched on, and if the collecting bag 18 is sufficiently empty that gas pressure can build up in the rear compartment 24, then the spring action 32 will be sufficiently counteracted via the gas pressure detection element 26 of Fig. 12, as a result of which the degree of filling indicator 30 moves to a neutral state (figure 12).

As soon as the collection bag 18 fills up and the gas pressure in the rear compartment 24 decreases, the spring force 18 will be greater than the force exerted by the gas pressure on the piston 28. As a result, the spring 32 pushes the degree of filling indicator 30 outwards to a state that is associated with a "full" state of the collection bag 18.

In the fourth preferred embodiment shown in Figs. 16-19, the particle collection device 1 has only one single compartment 22 and it is the rear wall 8 of the housing 2 which is provided with the passage opening 14 through which the collection bag 18 is at least in the partially filled condition. When the collection bag 18 fills up and closes the passage opening 14, a pressure will build up in the first compartment 22 of the housing 16 (Figure 17). The gas pressure 15 in the first compartment 22 exerts a force on the filling degree indicator 30 via the surface of the piston 28. As soon as this force exceeds the biasing force 32 of the spring, the fill degree indicator 30 is moved outward (Figure 19). The state of the fill degree indicator 30 shown in Figure 18 corresponds to a "neutral" position, and the state of the fill degree indicator 30 shown in Figure 19 corresponds to a state associated with a "full" collection bag 18.

It is noted that in the embodiments, openings 42 are provided in the housing 2 through which any excess pressure can flow away to keep the gas flow going at all times. Such openings 42 can optionally be provided with a non-return valve which only opens above a certain gas pressure in the housing.

However, it is also conceivable that the gas pressure detecting member is provided with such a passage opening 34 through which excess pressure can be discharged.

19

In a very special embodiment the passage opening 34 can be provided with a whistle element with which an acoustic signal tone can be generated when discharging excess pressure.

The embodiments described above, although showing preferred embodiments of the invention, are only intended to illustrate the present invention and not to limit the description of the invention in any way. In particular, it is noted that a person skilled in the art can combine technical measures of the different embodiments. The rights described are defined by the following claims in the scope of which many modifications are conceivable.

15

Claims (13)

Device (1) for collecting particles, in particular material and dust particles detached from a workpiece by machining, comprising: - a housing (2) with at least one front wall (4) provided with an inlet opening (12) through which the particles can be introduced into a volume (16) enclosed by the housing; 10. a collection bag (18) arranged in the housing (2) which is connected to the inlet opening (12) with a filling opening (20) and which is gas-permeable at least to some extent; - wherein the housing comprises a wall provided with a passage 15 (14) through which the collection bag (18) extends at least in a state filled with collected particles; - wherein the circumference of the collection bag (18) at least at the location of the passage opening (14) in the wall 20 is larger than the circumference of this passage opening (14), wherein the collection bag (18): - in a substantially unfilled state least gas passage through the passage opening (14); and - in a state filled with collected particles at a predetermined degree of filling, the passage opening (14) closes at least largely for gas passage; - wherein closing the gas passage through the passage opening (14) by the collecting bag (18) causes a pressure difference in a compartment (22, 24) of the housing (2); - wherein at least one gas pressure detection member (26) is provided which is adapted to detect this pressure difference and to indicate via at least one degree of filling indicator (30) that the predetermined degree of filling of the collection bag (18) has been achieved. 2. A particle collecting device according to claim 1, wherein the predetermined degree of filling of the collecting bag (18), wherein the filling degree indicator (30) indicates that the predetermined degree of filling of the collecting bag (18) is at least determined by the location where the of the passage opening ( 14) wall is provided around the collection bag (18). 3. A particle collection device according to claim 1 or 2, wherein the compartment in which the pressure difference is achieved by closing the passage opening (14) with the collection bag (18) is a first compartment (22) which is at least limited by the front wall ( 4) and the wall provided with the passage opening (14). Particle collection device according to claim 3, wherein the wall provided with the front opening (14) is the rear wall (8) of the housing (2). Particle collection device according to claim 3 or 4, wherein the wall provided with the passage opening (14) is an intermediate wall (10) arranged in the housing (2) which divides the volume (16) enclosed by the housing (2) into a first , front compartment (22) and a second, rear compartment (24). 30 Particle collection device according to one of the preceding claims, wherein the gas pressure detection element (26) comprises: - a detection element housing (21)} - a piston element (28) which is displaceably arranged in the detection element housing (27); - wherein the piston element (28) is biased by means of a spring (32) such that the piston element (28) only displaces the biasing force of the spring (32) when a force exerted thereon by a pressure difference exceeds the pre-stressing force of the spring (32) and a degree of filling indicator ( 30). 10 7. A particle collection device according to any one of claims 3-6, wherein the gas pressure detection element (26) is arranged in the first compartment (22) and is adapted to change the degree of filling indicator (30) to a full volume when there is a pressure increase in the first compartment (22). to move the indicator position. 8. A particle collection device according to any one of claims 3-7, wherein the gas pressure detection element (26) is arranged in the second compartment (24) and is adapted to move to a full-indication position in the event of a pressure reduction in the second compartment (24). 9. A particle collection device according to any one of claims 5-7, wherein the gas pressure detection element (26) is arranged in the second compartment (24) and is in gas communication with the first compartment (22) via a connecting channel (36), wherein the gas pressure detection element ( 26) is adapted to move the filling degree indicator (30) to a full-indication position when there is a pressure increase in the first compartment (22). 10. Particle-collecting device according to one of the preceding claims, wherein a stirring rod (40) is arranged in the collecting bag (18) which extends over substantially the entire length of the collecting bag near the filling opening (20) thereof. A particle collection device according to any one of the preceding claims, wherein the gas pressure detection member (26) is provided with an overpressure discharge opening (44). 10 A particle collection device according to claim 11, wherein a whistle element is provided in the overpressure discharge opening (44) which generates a whistle tone when passing gas. 15 A machining device, in particular a sanding machine, comprising a particle collection device according to any one of claims 1-12. 20