EP0345484B1 - Knocker with self-control - Google Patents

Description

The invention relates to a pneumatically operating knocker, in particular for knocking off dust-like material from container walls, for example bunker walls, with an elongated spring chamber with spring enclosing a vent hole and closed on one side by a top wall with a hole, a valve wall with a connection hole, with a against the pressure of the spring by means of compressed air towards the upper wall of the piston and with a quick exhaust valve located in the area of the valve wall, which vents the space under the piston by means of an air line into the spring chamber.

With pneumatic knockers of the type described above, dust-like materials in silos or other storage containers are detached from the walls if the stored materials stick or tend to form bridges. A powerful blow to the outer wall of the storage container can loosen the dusty material, destroy the bridge and make the material flow out.

Compressed air interval knockers currently on the market, as are known from DE-A-2549551, consist of a cylinder tube closed at the bottom on the container side with a baffle plate and at the top with a cover, in which the baffle plate and cover have a larger diameter than the outside diameter of the cylinder tube and are provided with four holes on the circumference, through which anchor bolts are inserted. A reversing valve is screwed onto the cover of the interval tapper, to which the compressed air supply line leads on the inlet side and from which a connecting nipple is branched off on the outlet side. A connection nipple is also inserted into the cylinder tube above the baffle plate, and a hose connects the two connection nipples to one another. The control of the known interval knocker could be automated to a certain extent, the control took place with the disadvantage, however, of a rod or a control pin on the piston, which necessitated complicated assembly and unreliable individual parts. In addition, it was not possible to control the beat interval or the pauses between one or between a group of hits with simple means, especially not in explosion-proof rooms. The control effort is particularly high if pneumatic controls are required, since two time relays are generally required, for the charging time and for the pause time.

Knockers are already on the market, in which the control is achieved in a complicated way by means of an internal reversal, namely by means of a needle valve built into the device, via drilled control lines. Due to the vibrations during operation when knocking, these needle valves adjust easily. A control or readjustment is very complex, since the knockers are often installed in an inaccessible place in a bunker. Another disadvantage is remote control, e.g. interval control from a distance is not possible.

The invention is therefore based on the object to improve a pneumatically operating knocker of the type mentioned in such a way that the control options can be expanded without negatively influencing the flow conditions insofar as automatic cycle controls of the piston strokes become possible without mechanical parts interacting with the piston.

The object is achieved in that a control bore in the housing side wall is arranged radially running in the assembly side third of the height of the housing and is connected via a control line with a 3/2-way air valve in the compressed air supply line and that the 3/2-way air valve with the connection hole in the valve wall is connected.

If air, compressed air, air valve or the like is mentioned here, it is understood by the person skilled in the art that of course other gases, in particular nitrogen, or also flow agents can generally be used in the sense of the invention.

It was explained at the outset that, with the knockers according to the invention, dust-like materials can be detached from walls and made to flow out. Of course, therefore, the knockers must be mounted on the walls of the container, the so-called "lower" part of the knocker being attached to the wall in the sense of the description given here. In general, the knocker has an elongated shape, so that, for the purposes of the description given here, the quick exhaust valve is arranged "up" and the piston strikes against the underside, namely against the lower surface of the knocker, which is arranged opposite the quick exhaust valve and which is attached to the container wall is. This lower surface of the knocker is referred to here as the assembly side. If you now consider the height of the housing and break it down into thirds, then it goes without saying that the assembly-side third of the height is the lower area with which the knocker is mounted on the wall of the silo or the like.

According to the teaching of the invention, a control bore is provided in the housing side wall, running radially through this, in said third of the height of the housing on the assembly side.

Of course, the knocker can be attached to the wall of a storage container in any position, and the explanations chosen with "above" or "below" are not intended to limit the arrangement or position of the knocker according to the invention.

The elongated space in which the piston moves back and forth can be polygonal, oval or versatile in cross-section with rounded corners, but this space is preferably cylindrical, because experience has shown that cylindrical pistons are easier to manufacture. In the lid-side 1 1/2 thirds of this interior there is the spring space mentioned above, in which the compression or compression spring is located, and in the lower third of this cavity in the housing there is a so-called "space under the piston". It is understood that when the knocker is actuated, the space under the piston can even be completely filled by the piston in a special embodiment.

The control bore mentioned in the housing side wall is therefore in the lower region of the housing. In contrast to oscillating piston vibrators, the knocker according to the invention effects individual impacts at adjustable intervals. Strong blows with low air consumption can advantageously be brought about. If the measures mentioned above are now used, the knocker according to the invention allows simple remote control in a very inexpensive and reliable manner. Because of the lower control bore mentioned in the knocker housing, a regulation for triggering a knocking blow can take place when the piston is shortly before the end position reached during loading. Then the control bore is under the piston freely outside the piston, and the air pressure under the piston actuates the 3/2-way air valve in the sense of venting the connection hole and thus triggering the knock.

Simply by creating this control bore without a linkage, without electrical drives, fields or the like, a control option is created according to the invention such that the knocker also works at intervals. All you have to do is switch off the compressed air supply by means of an inexpensive controller, which may be located remotely in the compressed air supply line, and the knocker stops operating.

It is also advantageous if a radial piston bore is arranged in the side wall of the hollow part of the piston. The control bore in the lower area of the housing and the piston bore are at approximately the same height after the knocker has struck and the piston located at the bottom in the final state. This facilitates air passage into the spring chamber. Although this is also present if there is no very good sealing seal in the upper, hollow part of the piston, but only a guide ring, for example, the throttling effect between the inner wall of the housing and the side wall of the hollow part of the piston is evidently bypassed if this piston bore in the side wall of the Piston is arranged.

The interval control according to the invention can also be used safely and inexpensively in explosion-proof rooms. For example, it is expedient if a throttle is arranged in the compressed air supply line between the air supply connection and the 3/2-way air valve. Since there are very precisely adjustable throttles, which are very inexpensive, the time for lifting the piston during the charging process can also be set quite precisely by regulating the throttle. The piston speed in the direction of the spring and thus the stroke interval can thus be regulated by the throttle. This system is particularly advantageous if a valve for the compressed air supply is installed between the air supply connection and the throttle in order to start or end the stroke intervals.

The control option described above is significantly improved compared to the known knockers. The new and inexpensive control is particularly advantageous if only one knocker is to be actuated at a time.

When using the commercially available work break control, which controls a valve located between the air supply connection and the throttle, the self-control function can also be used to cause the knocker to strike several times during a time sequence that would otherwise only trigger a blow. Very little resources are therefore sufficient for this purpose, whereas in the case of the knockers known hitherto, such a control required a great deal of effort.

The impact strength can also be regulated using a pressure regulator in the compressed air supply line.

The control according to the invention can be used with various knockers. There are knockers, for example, whose housings consist of a cylinder tube closed with a baffle plate at the bottom and top wall at the top, the quick-exhaust valve being screwed onto the top of the top wall. With such a knocker, vent holes are axially arranged in the top wall, because there is enough space here next to the quick vent valve accommodated in the cover area.

In this embodiment with the baffle plate arranged at the bottom, an optimal impact of the impact can be achieved, the piston striking the wall over the baffle plate like a steel hammer.

However, it can sometimes be preferred to provide sound insulation for the pneumatic knocker, in which its effect is slightly weaker, but the impact is noise-dampened like that of a rubber hammer. The baffle plate does not have such a second embodiment on the assembly side, rather the housing is open on the assembly side.

Figur 1

einen vertikalen Längsschnitt durch eine erste Ausführungsform eines Kopfers mit der erfindungsgemäßen Steuerung und

Figur 2

eine ähnliche Ansicht wie Figur 1, wobei jedoch eine zweite Ausführungsform eines Klopfers mit integriertem Gehäuse gezeigt ist, die Steueranlage jedoch in gleicher Weise vorgesehen wird.

Further advantages and possible uses of the present invention result from the following description of preferred embodiments in connection with the drawings. Show it:

Figure 1

a vertical longitudinal section through a first embodiment of a header with the control according to the invention and

Figure 2

a view similar to Figure 1, but showing a second embodiment of a knocker with an integrated housing, but the control system is provided in the same way.

The first embodiment of the invention shown in FIG. 1 shows a knocker with a housing 1 with a cylinder tube 1b, in which a piston 2 is movably mounted. In the rest position, the piston 2 is pressed upwards against the force of the spring 9 by compressed air acting against the piston head and entering the space 22 under the piston 2 in the direction of the double arrow, so that the side walls 2a of the hollow part 2b of the piston 2 Reduce spring space 13. The spring 9 is thereby tensioned. The knocker is "loaded".

The spring is attached to the top wall 20 with hole 10, which is connected at the top to a sleeve-shaped valve wall 3 with connection hole 8. In this wall 3, the quick exhaust valve with control membrane 11 and valve chamber 15 is arranged. The compressed air supply to the connection hole 8 takes place via the line 29, which creates the connection between the connection hole 8 mentioned and a 3/2-way valve 16. In the position of the valve 16 shown in the figures, compressed air is supplied via the compressed air supply line 19.

At the end of the cylinder tube 1 opposite the top wall 20 there is the baffle plate 1d, which is slidably inserted in the inner wall of the cylinder tube within certain limits by means of the seal 4.

The top wall 20 and the baffle plate 1d are secured by anchor bolts 21 held together. Between the nuts placed on the ends of the anchor bolts 21 and the upper wall 20 there are springs 23 which absorb the shock when actuated. The baffle plate 1d is connected to the wall of the storage container or the like either directly or via a damping material. The openings 27 intended for the insertion of screws are used for fastening. The space above the baffle plate 1d or below the piston is designated by 22 and is connected to the quick exhaust valve in the wall 3 via a connecting piece and a pipe 14.

On the piston seals 6 are provided radially at the bottom and a guide 12 at the top. You can also see the vent hole 7, with which the spring chamber 13 is in communication with the environment.

In the assembly-side third of the height H of the housing 1, a control bore 17 is arranged on the right-hand side according to FIG. 1, which is connected via a control line 18 to the 3/2-way air valve 16 in the compressed air supply line 19. The 3/2-way air valve 16 is connected to the connection hole 8 in the wall 3 via the line 29 mentioned.

In the other embodiment according to FIG. 2, the housing is constructed with integrated components, and the knocker shown there also differs from the embodiment in FIG. 1 in that the housing is open on the assembly side and the baffle plate 1d is omitted.

The same parts again have the same reference numbers. In both figures, the piston 2 is just in a state shortly before it hits the mounting level 24 below or hits the baffle plate 1d (FIG. 1) or after it has left it again during the upward stroke. The spring 9 is located in the hollow part 2b of the piston 2 within the side walls 1a and is supported against the solid part of the piston 2 on one side while it is on the on the opposite side against the upper wall 20 of the housing, in which a hole 10 is provided, which is surrounded at the top by a cylinder jacket-shaped collar 25.

According to FIG. 2, the approximately cylindrical jacket-shaped side walls 1a of the housing 1 end upwards in a somewhat widening collar 26 which is provided with an internal thread. The cover 3 is screwed into this, leaving a valve chamber 15. The cover can also be attached by radial screws.

The circular collar 26 lies coaxially with the collar 25 with the hole 10 lying further inwards. In the top wall 20, four air channels 14, for example evenly spaced over the circumference, open, which extend from the space 22 under the piston 2 to almost the entire height H of the housing 1 extend into the valve chamber 15. The housing 1 is expanded approximately rectangular at the bottom and has four screw holes 27, via which the housing 1 can be screwed to a wall of a storage container, not shown, with the interposition of the seal 4.

A seal 5 is also provided on the cover side, as is a seal 6 on the lower open end of the piston 2 and a guide ring 12 is arranged opposite on the cover-side hollow part 2b of the piston 2.

The ventilation holes 7 are arranged in the upper third (cover side) of the height H of the housing 1, radially extending through the side wall 1a, in such a way that a connection of the spring chamber 3 and, when the control membrane 11 is lifted off, also the air channels 14 to the outside air is ensured. The diameter of the vent hole 7 is preferably considerably smaller than that of the air channels 14.

In alignment with the hole 10 and coaxially there is a valve bore in the cover 3, in which a control membrane 11 made of rubber, plastic or another elastomer in the axial direction is slidably received up and down. The control membrane 11 can be pressed down so far that it lies on the annular end face of the collar 25 and seals the hole 10 at the appropriate pressure. In the middle of the cover and coaxially to this hole 10 and to the valve bore, the connection hole 8 is provided, to which the line 29 connects, which only provides a connection, between the connection hole 8 and a 3/2-way valve 16. This, in turn, lies in the line between the connection hole 8 and the compressed air supply line 19. A throttle 20 and an air supply connection 30 are also arranged in this, as shown in FIG. 2.

The control membrane 11 practically seals the valve chamber 15 more or less against the chamber 14a above the membrane 11. With a corresponding pressure difference between the two spaces 14a and 15, air can flow past the edges of the control membrane 11. This is desirable, as will be explained in the operating function.

The figures also show the valve spring 16a and the control bore 17, to which the control line 18 is connected, for example by screwing.

In operation, the knocker works according to both the one and the other embodiment (Figures 1 and 2) as follows.

Compressed air passes through the supply line 19 and the valve 16 through the connection hole 8 to the flexible control membrane 11, which is thereby pressed against the hole 10 to the spring chamber 13 and is pressed against the valve chamber 15 on the annular end face of the collar 25 while sealing the spring chamber 13 . Since the spring chamber 13 is connected to the ambient and outside air via the vent hole 7, the pressure on the control diaphragm 11 from the loaded side (from above) is greater than the pressure (from below) through the hole 10 resulting differential pressure ensures the pressure of the control membrane 11 on the collar 25 and thus the sealing of the hole 10. The compressed air which is present passes the flexible outer edge of the control membrane 11 via the channels 14 in the housing 1, which are, for example, drilled or cast or flanged as a hose in the embodiment of FIG. 1, under the piston 2 and presses it against the compression spring 9.

If the 3/2-way valve 16 used to actuate the knocker is closed, i.e. moved against the force of the spring 16a to the left from the position shown in the figures, so the connection hole 8 is vented for the compressed air. The space 14a located above the control membrane 11 is now in communication with the outside air. This increases the pressure under the control membrane 11 and raises it. The compressed air located under the piston 2 can now suddenly escape through the air channels 14 into the spring chamber 13 and from there via the vent hole 7 to the outside. The spring 9 can now shoot the piston 2 against the clamping surface or mounting surface 24. This causes the mass to accelerate, e.g. the wall to which the knocker is attached.

Near or at any distance from the knocker between the lines 29 and 19, the 3/2-way air valve 16 is mounted so that its air outlet A is connected to the connection hole 8 for compressed air. In the position shown, the valve 16 is open, i.e. the air outlet A is connected to P and the knocker is charged as soon as the air supply connection 30 can supply air.

With a control, not shown, e.g. By means of a ball valve, which can be arranged between the air supply connection 30 and the adjustable throttle 20, the compressed air supply line 19 can be placed under operating pressure.

Shortly before the cover-side or upper end position of the piston 2 reached during loading, the control bore 17 is then below the position of the seal 6 that is then reached in this way, a connection between the space 22 under the piston 2 and the control connection Z of the valve 16 is provided via the control line 18.

From the position shown in the figures, the valve 16 moves against the force of the spring 16a to the left (FIG. 2) or downwards (FIG. 1), so that the valve closes the line from P to A and the connection from A to R opens. So that the knocker is actuated, because the connection hole 8 is vented.

After the impact, that is, when the force in the spring 9 has moved the piston 2 downward, a piston bore 15a, which is shown in the embodiment of FIG. 2 in the side wall 2a of the hollow part 2b of the piston 2, passes radially into the Area of the control bore 17. As a result, the valve 16 can be vented via the control line 18 via the spring chamber 13 and the vent bore 7. The spring 16a now returns the valve 16 to the position shown. The game can start again.

The throttle 20 arranged in the compressed air supply line 19 between the air supply connection 30 and the valve 16 regulates the piston speed and thus also the stroke interval.

It goes without saying that the control line 18, which extends schematically outside the housing 1 in FIG. 2, can also be placed in the housing jacket. In the embodiment of Figure 2, the quick exhaust valve is integrated in the cover end of the housing 1; in the embodiment of FIG. 1, it is screwed onto the top wall 20.

With the new control, the knocker can be used for special applications. For example, bakeries sometimes need smaller knockers, in which it is also desirable that the container is almost completely emptied of the filling material, for example flour or baking powder, namely if another filling material is to be filled in after emptying.

The knocker can then be adjusted to knock five times for residual emptying of the container simultaneously during container emptying with no control other than a throttle. Opening cylinders and knockers could be supplied via the same valve.

Claims (3)

1. Pneumatically operating knocker, particularly for knocking pulverulent material off container walls, for instance bunker walls, with a housing (1) which is closed on one side by an upper wall (20) with a hole (10) and which encloses an elongate spring space (13) with a spring (9) and having a vent bore (7), a valve wall (3) with a connecting hole (8) with a piston (2) which is movable by means of compressed air towards the upper wall (20) against the pressure of the spring (9) and with a rapid vent valve (3,8,10,11,14a,15) which is disposed in the vicinity of the valve wall (3) and which vents the space (22) below the piston (2) by means of an air line (14) into the spring space (13), characterised in that a control bore (17) is arranged in the housing side wall (1a) extending radially within the one third of the height (H) on the mounting side of the housing (1) and is in communication via a control line (18) with a 3/2-way air valve (16) in the compressed air supply line (19) and that the 3/2-way air valve (16) is connected to the connecting hole (8) in the valve wall (3).
2. Knocker as claimed in claim 1, characterised in that the piston (2) has an axially extending hollow portion (2b) defined by a side wall (2a) of the piston (2), a radially extending piston bore (15a) being arranged in the side wall (2a) of the hollow portion (2b) of the piston (2).
3. Knocker as claimed in claim 1 or 2, characterised in that a throttle (20) is arranged in the compressed air supply line (19) between the air supply connector (30) and the 3/2-way air valve (16).

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