EP3612349B1 - Abrasive cut-off machine - Google Patents

Description

The present invention relates to a power cutter with a gear neck for connecting a dust hood equipped with a flange.

Such cut-off machines are basically known from the prior art (see e.g. WO 2017/051893 A1 ). In order to avoid the spread of dust during cutting work, dust hoods are typically equipped with a dust hood through which a substrate material can be extracted from the hood body. Furthermore, dust hoods are known which have a rinsing connection via which rinsing water can be fed into the dust hood for the purpose of removing dust. Both types of dust hoods protect the health of a user of the power cutter.

It is the object of the present invention to provide a cut-off grinder which is set up in particular with a view to operating with a dust hood in order to avoid operating errors.

The object is achieved in that the cut-off machine has a sensor unit, by means of which it can be detected which type of dust hood is connected to the cut-off machine, the cut-off machine also having rotational direction control electronics that are signal-connected to the sensor unit, such that the direction of rotation of a cutting wheel of the cut-off machine depending on the type of dust cover detected by the sensor unit.

The invention includes the knowledge that cutoff grinders of the prior art can be operated in different modes of use, these also depending in particular on the type of cutting and the dust removal. For example, with so-called dry cutting without dust extraction, a cut-off wheel of the cut-off machine is driven in the same direction of rotation. The same is the case with so-called wet cutting, in which rinsing water is brought into the dust hood via a rinsing connection. In the case of dry cutting with dust extraction, however, an opposite direction of rotation of the cut-off wheel of the cut-off machine is preferred.

With the sensor unit provided according to the invention and the electronic direction of rotation control electronics connected to this sensor unit, a direction of rotation of a cutting disc can now be automatically preselected, namely depending on the type of dust hood detected by the sensor unit. As a result, operating errors in preselecting the direction of rotation can be excluded, which significantly increases the safety and health of a user of the cut-off machine.

In a particularly preferred embodiment, the sensor unit can be used to detect whether the dust hood is connected to the power cutter. The rotation control electronics are preferably further designed to prevent rotation of the cutting wheel when no dust hood is connected to the cutting machine.

It has been found to be advantageous if the sensor unit is arranged on a surface of the cut-off machine, preferably close to the gear neck. The sensor unit can be arranged on a handle face of the cut-off machine. Basically, it should be noted that depending on the specific space available on the cut-off machine and depending on the technical feasibility, the position of the sensor unit can be adapted accordingly to the cut-off machine.

It has been found to be advantageous if the sensor unit has a hood contact by means of which it can be detected whether the dust hood is connected to the cut-off machine. The sensor unit can likewise preferably have a hood-type contact, by means of which a preferably mechanical coding of the dust hood connected to the cut-off machine can be read out.

The hood contact and / or the hood-type contact can be provided in the form of a switch, a button, a magnetic contact or a light barrier. A combination of these components is also conceivable. Some preferred configurations are to be described in more detail below.

The hood-type contact can be provided, for example, in the form of an on / off / on slide switch which is arranged on a surface of the power cutter. The slide switch can for example be set up and arranged in such a way that an inclined plane formed on the dust hood actuates the slide switch. In this respect, an inclined plane of a hood can represent a mechanical coding that is read out by the hood-type contact, in the present example the slide switch. Accordingly, different inclined planes are to be provided on different hood types.

As an alternative or in addition to the inclined plane described, mechanical codings in the form of a projection, recess or the like can be provided on the dust hood. The slide switch can be arranged, for example, so that it is pushed to the right when a dust hood with a suction nozzle, which has a first mechanical coding, is connected. It can also be provided that the slide switch is pushed to the left when a dust hood with flushing connection, which has a second coding different from the first coding, is attached. Alternatively or additionally, it can be provided that, if no dust hood is arranged on the cut-off machine, the slide switch remains in the middle position and, caused by the electronic direction of rotation control, rotation of the cut-off wheel is completely prevented.

The invention is also achieved by a system with a cut-off grinder as described above and two dust hoods of different types, the type being defined in each case by a preferably mechanical coding that can be read out by the cut-off machine's sensor unit.

The invention is also achieved by a dust hood which has a preferably mechanical coding on its surface, which can be read out by a sensor unit of a cut-off machine.

In the following, preferred configurations of the cut-off machine are to be described. In all the exemplary embodiments described, it is preferably provided that when the sensor unit detects a dust hood with a flushing connection, a co-rotating direction of rotation of the cutting disc is specified and / or when the sensor unit detects a dust hood with a suction nozzle, the cutting disc is given an opposite rotating direction.

The hood contact and the hood-type contact can be functionally integrated, for example by providing an on / off / on toggle switch, which is preferably to be operated by an elevation on a dust hood. For example, it can be provided that a dust hood with flushing connection actuates the toggle switch to a first on position, whereby an electrical signal is fed to the electronic direction of rotation control electronics, which leads to a co-rotating direction of rotation of the cutting wheel when the cut-off machine is activated.

The toggle switch can be brought into the second on position by attaching a dust hood with a suction nozzle. Accordingly, the cutting wheel rotates in the opposite direction. When the toggle switch is in the off position (middle position), rotation of the cutting disc is preferably completely prevented, since no dust hood is connected to the cutting grinder. From this example it is particularly clear that one and the same switching element, that is to say in the present case the toggle switch, can form both the hood contact and the hood-type contact.

Instead of the on / off / on toggle switch just described, an on / on toggle switch can also be provided. This is preferably actuated by an inclined plane on the hood. In this exemplary embodiment, the toggle switch forms exclusively a hood-type contact, via which the opposite direction of rotation or the same direction of rotation can be specified.

In a further preferred embodiment, the sensor unit can have two buttons, which together realize the hood contact and the hood-type contact. The buttons are preferably arranged in such a way that a first mechanical coding on the dust hood with flushing connection actuates the first button and does not actuate the second button. Whereas a dust hood with suction nozzle has a second coding different from the first coding, which actuates the second button and leaves the first button unactuated. If neither a dust hood with a suction nozzle nor a suction hood with a rinsing connection is connected to the power cutter, both buttons preferably remain unactuated. In this case, rotation of the cutting wheel is prevented by the direction of rotation control electronics as soon as the cut-off machine is activated.

In a further preferred embodiment, the sensor unit of the cut-off machine has only one hood-type contact, which is preferably provided in the form of a button. The direction of rotation control electronics are set up to specify a co-rotating direction of rotation when the button is pressed and to specify an opposite direction of rotation when the button is not pressed.

In a further preferred embodiment, the hood contact and / or the hood-type contact can be provided by one or more light barriers. It is preferably provided that a mechanical coding of the dust hood with flushing connection causes an interruption of the first light barrier and a mechanical coding on the dust hood with suction nozzle causes an interruption of the second light barrier. In this respect, realize the first and second photoelectric switches have a hood-type contact. If neither of the two light barriers is interrupted, this means that none or a non-manufacturer dust hood is connected to the power cutter. The first and second light barriers also realize a cover contact which has the effect that if neither of the two light barriers is interrupted, rotation of the cutting disc is prevented.

In a further embodiment, precisely one light barrier can be provided which only acts as a hood-type contact. It can be provided that a dust hood with a flushing connection interrupts this light barrier, whereas a dust hood with a suction connection does not interrupt the light barrier.

In a further preferred embodiment, the hood contact and / or the hood-type contact can be implemented by one or more magnetic switches that are provided by magnets on the hood. In this respect, the magnetic switches define the sensor unit and the magnet or magnets on the hood a mechanical coding. It is preferably provided that a dust hood with suction nozzle has a first magnetic coding which actuates a first magnetic switch, for example a reed contact. It can further be provided that a dust hood with flushing connection has a second coding different from the first magnetic coding, which is arranged in such a way that the second magnetic switch on the power cutter is activated. If no dust hood is provided on the cut-off machine, the electronic direction of rotation control prevents the cutting wheel from rotating.

The switching functions of the individual contacts explained in the context of the exemplary embodiments can of course also be logically inverted.

According to an aspect that can be independently protected, a power cutter with a gear neck for connecting a dust hood equipped with a flange is provided. The cut-off machine has a sensor unit, by means of which it can be detected whether a dust hood is connected to the cut-off machine, the power cut-off machine also having a rotational direction control electronics which is signal-connected to the sensor unit, such that a rotation of the cutting wheel is prevented if no dust hood is on connected to the power cutter.

• Detektieren, mittels einer von dem Trennschleifer umfassten Sensoreinheit, welcher Typ von Staubhaube am Trennschleifer angeschlossen ist,
• Steuern einer Drehrichtung der Trennscheibe des Trennschleifers in Abhängigkeit des von der Sensoreinheit detektierten Zustands.

The invention is also achieved by a method for operating a cut-off machine with a gear neck for connecting a dust hood equipped with a flange, the method comprising the following steps:

• Detecting, by means of a sensor unit comprised by the power cutter, which type of dust hood is connected to the power cutter,
• Controlling a direction of rotation of the cutting wheel of the cut-off machine as a function of the state detected by the sensor unit.

The step of detecting preferably includes reading out a mechanical coding of the dust hood connected to the power cutter.

The cutoff grinder is preferably a handheld power tool. The power cutter is particularly preferably battery-operated, i.e. in particular without a power cord.

Further advantages emerge from the following description of the figures. Various exemplary embodiments of the present invention are shown in the figures. The figures, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into useful further combinations.

Fig. 1

ein bevorzugtes Ausführungsbeispiel eines erfindungsgemäßen Trennschleifers;

Fig. 2

ein bevorzugtes Ausführungsbeispiel eines Systems mit einem Trennschleifer und zwei Staubhauben unterschiedlichen Typs;

Fig. 3

ein weiteres Ausführungsbeispiel eines erfindungsgemäßen Trennschleifers;

Fig. 4

ein anderes bevorzugtes Ausführungsbeispiel eines erfindungsgemäßen Trennschleifers; und

Fig. 5

ein erfindungsgemäßes Verfahren zum Betreiben eines Trennschleifers.

In the figures, the same and similar components are numbered with the same reference symbols. Show it:

Fig. 1

a preferred embodiment of a power cutter according to the invention;

Fig. 2

a preferred embodiment of a system with a power cutter and two dust hoods of different types;

Fig. 3

a further embodiment of a power cutter according to the invention;

Fig. 4

another preferred embodiment of a power cutter according to the invention; and

Fig. 5

a method according to the invention for operating a cut-off machine.

Embodiments:

A preferred embodiment of a power cutter 200 according to the invention is shown in FIG Fig. 1 shown. Attached to the cut-off machine 200 is a dust hood 100 for covering at least sections of a circular cutting disk 220 on both sides. The dust hood 100 has a suction connection 40 via which a substrate material can be extracted from the hood body 10. The suction nozzle 40 has a flap 45. A suction hose to be inserted into the suction nozzle 40 is shown in FIG Fig. 1 not shown.

The cutoff grinder 200 has a sensor unit 20 which is arranged on a surface OF of the cutoff grinder 200. The cut-off machine 200 also has rotational direction control electronics 230, which are signal-connected to the sensor unit 20 via the signal line 80. The direction of rotation control electronics 230 are set up to predetermine the direction of rotation of the cutting disk 220 as a function of the sensor signal SL originating from the sensor unit 20.

The sensor unit 20 has a hood-type contact 27 in the form of a button, by means of which a mechanical coding 110 of the dust hood 100 can be read out. In the in Fig. 1 The illustrated embodiment, the mechanical coding 110 is implemented by an inclined plane which is formed on the hood body 10 of the dust hood 100.

The direction of rotation control electronics 230 is set up to bring about an opposite direction of rotation GGD of the cutting wheel when the button (hood type contact 27) is actuated. This corresponds to a dry cutting operation with dust extraction.

If, however, instead of the dust hood 100 with suction nozzle 40, for example, a dust hood with a flushing connection (cf. Fig. 2 : Dust hood 100 ') is connected to the cut-off machine, the direction of rotation control electronics 230 would specify a parallel direction of rotation GLD, which would mean a wet cutting operation without dust extraction.

Fig. 2 shows a system 600 with a power cutter 200 and two dust hoods 100, 100 'of different types. Up in Fig. 2 A dust hood 100 with a suction nozzle 40 can be seen. A suction hose 400 can be inserted into the suction nozzle 40, via which a subsurface material UG can be sucked out of the dust hood 100. A first mechanical coding 110 in the form of a simple elevation is formed on the hood body 10 of the dust hood 100.

Bottom right in Fig. 2 Another type of dust hood is shown, namely a dust hood 100 ′ with a rinsing connection 50. A rinsing hose 500 can be connected to the rinsing connection 50. The dust hood 100 'has a second mechanical coding 110' in the form of a double elevation.

On the left of the Fig. 2 The cut-off grinder 200 is shown with a gear neck 210, to which both the dust hood 100 with suction nozzle 40 and the dust hood 110 with flushing connection 50, in each case via its flange 90, can be connected.

In the present exemplary embodiment, the cut-off machine has a sensor unit 20 which has both a hood contact 25 and a hood-type contact 27. For example, the hood contact 25 and the hood contact 27 should be functionally integrated in the form of an on / off / on toggle switch.

The cut-off machine 200 has an electronic direction control unit 230 which is connected to the sensor unit 20 via a signal line 80. The direction of rotation control electronics 230 is set up, the direction of rotation of the cutting disc 220 (cf. Fig. 1 ) as a function of the type of dust hood detected by the sensor unit 20.

The direction of rotation control electronics 230 is further developed, a rotation of the cutting disc (cf. Fig. 1 ) if - as in Fig. 2 shown - none of the dust hoods 100, 100 'are connected to the power cutter 200.

The sensor unit 20, which has the said on / off / on toggle switch, is moved into a first on position when the dust hood 110 with flushing connection 50 is connected and is pushed into the second on position when the dust hood 100 with suction nozzle 40 is connected. If neither of the two dust hoods 100, 100 ′ is connected to the cut-off grinder 200, the toggle switch, not shown in detail here, is in the middle position, which prevents rotation of the cut-off wheel 220 when the cut-off grinder 200 is activated. This is brought about by the correspondingly configured rotational direction control electronics 230.

Fig. 3 shows a further preferred embodiment of a cut-off grinder 200 according to the invention. The cut-off grinder 200 has a sensor unit 20 on a handle face GF, which in the embodiment shown here has only one hood-type contact 27 in the form of a magnetic contact.

The dust hood 100 with suction nozzle 40 shown above the cut-off grinder 200 has a magnet embedded in the hood body as coding 110.

If the dust hood 100 is connected to the power cutter 200, the hood type contact 27 in the form of a magnetic switch is actuated by the coding 110 in the form of a magnet, i.e. electrically closed. The electrical closing of the magnetic switch is evaluated by the rotational direction control electronics 230 in terms of a sensor signal.

In the present exemplary embodiment, the rotational direction control electronics 230 are set up, with the dust hood 100 attached, ie with the magnetic contact closed, the cutting disc 220 (cf. Fig. 1 ) to be driven in the opposite direction of rotation GGD.

Fig. 4 Finally, FIG. 3 shows another preferred exemplary embodiment of a cut-off grinder 200 according to the invention. This has a sensor unit 20 on its surface OF, which in the exemplary embodiment shown here is provided by a hood contact 25 and a hood-type contact 27, each in the form of a discrete button.

The hood contact 25 and the hood-type contact 27 are functionally integrated, which will be explained in more detail below. The mechanical coding 110 on the dust hood 100 with suction nozzle 40 is set up to actuate the lower of the two buttons. The connection of a dust hood (not shown here) with a rinsing connection would activate the upper of the two buttons. In this respect, the two buttons act together as a hood-type contact 27, on the basis of whose switching state the direction of rotation of the cutting disc is specified.

At the same time it is provided that if both buttons remain unactuated, so as in Fig. 4 shown, no dust hood 100 is connected to the power cutter 200, the power cutter 200 remains at rest when activated. In this respect, the buttons, which are not shown in more detail here, also act synergistically as a cover contact 25, by means of which it can be detected whether a dust cover is connected to the cut-off machine.

Fig. 5 Finally, FIG. 4 shows a method according to the invention for operating a power cutter, for example the power cutter 200 described with reference to the previous figures. In a first step S1, a sensor unit comprised by the power cutter detects which type of dust hood is connected to the power cutter. In a second step S2, a direction of rotation of the cut-off wheel of the cut-off machine is controlled as a function of the state detected by the sensor unit.

List of reference symbols

10

Hood body

20th

Sensor unit

25th

Hood contact

27

Hood type contact

40

Suction nozzle

45

flap

50

Flushing connection

80

Signal line

90

flange

100

Dust hood with suction nozzle

100 '

Dust hood with flushing connection

110

Coding on the dust hood with suction nozzle

110 '

Coding on the dust hood with flushing connection

200

Power cutter

210

Gear neck

220

Cutting disc

230

Rotation direction control electronics

240

interface

400

Suction hose

500

Flushing hose

600

system

GF

Handle face

GGD

opposite direction of rotation

GLD

co-rotating direction of rotation

OF

surface

SL

Sensor signal

S1, S2

Procedural steps

Basement

Subsurface removal

Claims (10)

1. Cut-off grinder (200) having a gear neck (210) for connecting a dust hood (100, 100') provided with a flange (90), characterized in that the cut-off grinder (200) has a sensor unit (20) by means of which the type of dust hood (100, 100') connected to the cut-off grinder (200) can be detected, the cut-off grinder (200) also having rotational direction control electronics (230), which are signal-connected to the sensor unit (20) such that the rotational direction (GGD, GLD) of a cutting disc (220) of the cut-off grinder (200) is specified depending on the dust hood type detected by the sensor unit (20).
2. Cut-off grinder (200) according to Claim 1,
   characterized in that it can be detected by means of the sensor unit (20) whether the dust hood (100, 100') is connected to the cut-off grinder (200), the rotational direction control electronics (230) also being designed to prevent rotation of the cutting disc (220) if no dust hood (100, 100') is connected to the cut-off grinder (200).
3. Cut-off grinder (200) according to Claim 1 or 2,
   characterized in that the sensor unit (20) is arranged on a surface (OF) of the cut-off grinder, preferably close to the gear neck (210).
4. Cut-off grinder (200) according to one of the preceding claims,
   characterized in that the sensor unit (20) is arranged on a handle end face (GF) of the cut-off grinder (200).
5. Cut-off grinder (200) according to one of the preceding claims,
   characterized in that the sensor unit (20) has a hood contact (25) by means of which it can be detected whether the dust hood (100, 100') is connected to the cut-off grinder (200).
6. Cut-off grinder (200) according to one of the preceding claims,
   characterized in that the sensor unit (20) has a hood type contact (27) by means of which preferably mechanical coding (110, 110') of the dust hood (100, 100') connected to the cut-off grinder (200) can be read.
7. Cut-off grinder (200) according to Claim 4 or 5,
   characterized in that the hood contact (25) and/or the hood type contact (27) is provided in the form of a switch, a pushbutton, a magnetic contact or a light barrier.
8. System (600) comprising a cut-off grinder (200) according to one of the preceding claims, and two dust hoods (100, 100') of different types, the type being established in each case by a preferably mechanical coding (110, 110'), which can be read by the sensor unit (20) of the cut-off grinder (200).
9. Method for operating a cut-off grinder having a gear neck for connecting a dust hood provided with a flange, the method comprising the steps of:

   - (S1) detecting by means of the sensor unit comprised by the cut-off grinder which type of dust hood is connected to the cut-off grinder,

   - (S2) controlling a rotational direction of the cutting disc of the cut-off grinder depending on the state detected by the sensor unit.
10. Method according to Claim 9,
    characterized in that the detecting step (S1) includes reading a mechanical coding of the dust hood connected to the cut-off grinder.

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