EP1360032B1 - Hand-held machine tool for grinding, polishing or the like - Google Patents

Description

State of the art

The invention relates to a hand tool for grinding, polishing or the like according to the preamble of claim 1. Such a power tool is off WO 94/07654 A known.

It is known to design a hand tool of the type mentioned in the introduction so that both a sanding disc movement of an orbital sander and a sanding disc movement of an eccentric sander can be realized with it. The grinding plate movement of an orbital sander is characterized by an orbital or also eccentrically named movement, and the grinding-plate movement of an eccentric sander is characterized by an orbital and a rotating movement. A hand tool that can be used both as a sander and as an orbital sander, represents a so-called multi-sander.

The choice of the respective Schleußerellerbewegungsart takes place in such a power tool by the attachment of a correspondingly shaped grinding plate.

Furthermore, from the WO 94/07654 a hand tool machine is known, which has a switching device by means of which two types of sanding disc movement are selectable.

Advantages of the invention

The invention relates to a power tool for grinding, polishing or the like, with a drive motor, coupled to the drive motor gear and operatively connected to the grinding sanding pad, wherein the transmission has a switching device by means of at least two types of sanding pad movements are preselected, the Switching device cooperates with two meshing gears, one of which is connected to the sanding pad, and wherein the switching device comprises at least one locking bolt, which cooperates with at least one recess of the first or the second gear.

It is proposed that the switching device has a first locking bolt for engagement in a recess of the first gear and a second locking bolt for engagement in a recess of the second gear. A hand tool of such a design has the advantage that without assembly work, an adaptation of the machine to the required type of movement of the grinding divider is possible, without changing the grinding plate. The hand tool according to the invention thus provides a high ease of use and a great deal of flexibility in terms of conditions of use.

In an advantageous embodiment of the hand tool according to the invention, an orbital movement of the grinding disc takes place in at least one selectable movement. In this case, the user has an orbital sander available in at least one preselectable operating mode.

With at least one preselectable movement type, a rotation of the sanding pad can take place. The rotation can be triggered either by the orbital movement of the sanding pad or, when the sanding pad is in rotation with a freewheel, by the machining of a surface. With a freewheel with respect to the rotation, a particularly high quality of the surface treated by means of the machine tool can be achieved, since the freewheel leads to a gentle surface treatment in that the sanding pad may optionally yield rotationally.

If an orbital movement of the sanding plate triggers a self-rotation of the sanding pad, the sanding pad is subjected to a so-called forced drive. This is usually done in such a way that an additional self-rotation is imposed on the sanding plate via an armature shaft of the drive motor and an eccentric sleeve connected thereto.

It is also conceivable that by means of the switching device, for example, a pure rotary motion or only a self-rotation of the grinding plate is preselected.

Furthermore, it is conceivable that by means of the switching device different eccentric strokes or different grinding disc speeds are preselected.

The hand tool according to the invention may be designed so that by means of the switching device, the rotation of at least one of the gears can be prevented. Thus, the rotational behavior of the two gears and the relative movement of these mutually influenced in an advantageous manner, and thus the Schleelzellerbewegungsart be adjusted.

A structurally particularly simple and space-saving embodiment of the hand tool according to the invention is when the first gear connected to the sanding pad has an outer toothing that meshes with an internal toothing of the second gear. The first gear is then so-called planetary gear and the second gear is formed as a so-called ring gear. By appropriate selection of the gears, a transmission ratio is adjustable, which advantageously allows a high oscillation frequency of the sanding disc at the same time low sanding disc speed.

Suitably, the gear is arranged with the internal toothing in a sliding bearing ring. On the one hand, this represents a space-saving storage of this gear wheel and, on the other hand, has the advantage that only slight frictional forces have to be overcome during rotation of this gear wheel. It is also conceivable, for example, that the gear is arranged with the internal toothing in a rolling bearing.

In the case of a trained as a planet gear with external teeth, which is on the one hand with the drive shaft of the drive motor and the other hand with the sanding plate in connection, is mounted eccentrically and meshes with the internal teeth of a ring gear, causes the engagement of the locking bolt in the recess of the planetary gear, which to compensate for the eccentric drive movement expediently has a larger diameter than the locking bolt, a vibratory grinding or a purely orbital motion of the grinding plate, wherein the ring gear is slidably carried in the sliding bearing ring.

However, the locking bolt engages in a recess of the Xohlrads, whereby its rotation is prevented in the sliding bearing ring, the planetary gear in its eccentric motion is imposed a self-rotation. There is therefore a so-called forced drive. The eccentric movement of the planetary gear is thus superimposed by a self-rotation of the same.

If the locking bolt engages neither in a recess of the planetary gear nor in a recess of the ring gear, then the planetary gear is in freewheeling. The one with the planetary gear Connected sanding pad can thus also rotate freely.

Advantageously, the switching device for displacing the at least one locking bolt comprises a switching ring. The switching ring represents the actuating device for the at least one locking bolt. The switching ring is mounted for example in a preferably two-part housing of the transmission and actuated in the circumferential direction.

Preferably, the switching ring has at least one axial, circular arc-shaped recess in which a locking bolt is guided. If the switching device has two locking bolts, the switching ring preferably has two recesses, into each of which a locking bolt is guided.

Advantageously, the switching ring in the region of the at least one axial, circular arc-shaped recess has a ramp-like slope, by means of which the at least one locking bolt is axially displaceable by rotating the switching ring. By appropriate arrangement of the bevels, it is possible that a larger diameter with an area on the upper part of the switching ring resting latch bolt in a position of the switching ring in a recess of the first gear and the other locking bolt in a different position Switching rings engages in a recess of the second gear.

In order to keep the at least one locking bolt in position, this is preferably loaded by a spring in the axial direction.

A particularly simple embodiment of such a spring is in a spring plate, which engages in a recess or a slot of the locking bolt and this axially loaded.

The switching ring can be manually operated, so that it can be brought by simple manual offset in the particular desired switching position, or it can also be operated with a control and / or regulating unit via an actuator.

In order to be able to use the hand tool according to the invention in a comfortable manner in a variety of surfaces with different layouts without changing the sanding pad, the sanding pad preferably has a plan, which has at least one straight boundary edge and at least one arcuate boundary edge.

drawing

Further advantages emerge from the following description of the drawing. In the drawing, an embodiment of the invention is shown. The drawing, 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 meaningful further combinations.

Fig. 1

eine schematisch dargestellte Schleifmaschine nach der Erfindung im Exzenterschleifbetrieb im Teilschnitt,

Fig. 2

die Schleifmaschine nach Fig. 1 im Schwingschleifbetrieb mit Freilauf in einer Fig. 1 entsprechenden Darstellung,

Fig. 3

die Schleifmaschine nach Fig. 1 im Schwingschleifbetrieb in einer Fig. 1 entsprechenden Darstellung,

Fig. 4

eine perspektivische Darstellung einer Schaltvorrichtung der Schleifmaschine nach Fig. 1,

Fig. 5

eine schematische Explosionsdarstellung der Schaltvorrichtung nach Fig. 4 mit zwei kämmenden Zahnrädern und

Fig. 6

eine manuelle Betätigungsvorrichtung der in Fig. 4 und 5 dargestellten Schaltvorrichtung in einer Seitenansicht.

Show it:

Fig. 1

a schematically illustrated grinding machine according to the invention in the eccentric grinding operation in partial section,

Fig. 2

the grinder after Fig. 1 in vibratory grinding operation with freewheel in one Fig. 1 appropriate representation,

Fig. 3

the grinder after Fig. 1 in vibratory grinding operation in one Fig. 1 appropriate representation,

Fig. 4

a perspective view of a switching device of the grinding machine according to Fig. 1 .

Fig. 5

a schematic exploded view of the switching device according to Fig. 4 with two meshing gears and

Fig. 6

a manual actuator of in Fig. 4 and 5 illustrated switching device in a side view.

In Fig. 1 to 3 a hand grinder 10 is shown. The hand grinder 10 comprises a not visible here electric motor, which is arranged in a device housing 12 and an armature shaft 14 drives. The armature shaft 14 rotatably engages in an eccentrically arranged recess 16 of a so-called eccentric sleeve 18.

At the in Fig. 1 to 3 shown below, the eccentric sleeve 18 has a centrally disposed bore 20, in which a screw 22 engages, which serves for fastening a first gear 24. The first gear 24 is rotatably mounted on the eccentric sleeve 18 via a ball bearing 26 and rotatably connected to a sanding pad 28.

The sanding pad 28 may have different embodiments depending on the application. So is in Fig. 1 and 2 in each case a sanding disc for eccentric sanding operation shown. On the other hand is in Fig. 3 a sanding pad 28 shown for vibratory grinding operation. However, a suitably suitable sanding pad can also be used for all preselectable operating modes.

Due to the staggered arrangement of the recess 16 and the bore 20 of the eccentric sleeve 18, the sanding pad 28 is mounted eccentrically relative to the armature shaft 14. The axis of the grinding plate 28 therefore always performs in operation an eccentric movement, a so-called orbital motion, to the axis of the armature shaft.

The grinding machine 10 has a switching device 30, by means of the different types of movement of the grinding plate 28 are preselected and the in 4 to 6 is shown in enlarged views. The switching device 30 has a two-part housing 32, which communicates with the device housing 12 in conjunction or forms with this a structural unit and which, among other things, the first gear 24 encloses. Furthermore, a sliding bearing ring 36 is received in an annular groove 34 of the housing 32, which serves as a bearing for a relative to the sliding bearing ring 36 concentrically arranged second gear 38 with an internal toothing, not shown in the drawing. The thus formed as a so-called ring gear second gear 38 meshes with the first gear 24, which also has an external toothing, not shown in the drawing and represents a so-called planetary gear. The meshing region of the two gears 24 and 38 shown in the drawing is each provided with the reference numeral 40.

The second gear 38 is further provided with circumferentially regularly arranged, axial bores 42 which are formed like a blind hole ( 4 to 5 ). The gear 24 with the external toothing is also provided with circumferentially regularly arranged, axial bores 44. However, these are formed as through holes.

The switching device 30 has a so-called switching ring 96, which is guided displaceably in the housing 32 in the circumferential direction. The switching ring 46 has an actuating handle 48, which passes through a radial slot 50 of the housing 32 and is arranged displaceably in the circumferential direction of the housing 32 in the radial slot 50.

The switching ring 46 is arranged eccentrically relative to the housing 32 and serves to select different types of movement of the grinding plate 28. For this purpose, the switching ring 46 has two arcuate, the switching ring 46 axially sweeping recesses 52 and 54. In the region of the recesses 52 and 54, two ramp-shaped bevels 56 and 58 are formed on the upper side of the switching ring, which connect an upper switching level 60 with a lower switching level 62 , In the recesses 52 and 54 each extending in the axial direction locking bolt 64 and 66, respectively. The locking bolt 64, which is slightly longer than the locking bolt 66, serves to engage in one of the bores 42 of the second gear 38. On the other hand, the locking bolt 66 is used to engage in one of the bores 44 of the first gear 24.

The locking bolts 64 and 66 each have a head 76 and 78, which rests on the top of the switching ring 46, in particular depending on the position of the switching ring 46 either on the upper switching level 60 or on the lower switching level 62.

The locking bolts 64 and 66 are each loaded by a trained as a spring plate spring 68 and 70 in the direction of engagement position in the holes 42 and 44 in the axial direction. The springs 68 and 70 engage in slots 72, 74 on the heads 76, 78 of the bolts 64, 66 and are clamped with their ends facing away from the locking bolt in the housing 32.

At the in Fig. 1 illustrated switching position is the switching ring 46 in a rotational position in which the head 76th of the locking bolt 64 rests on the lower switching level 62, the locking bolt 64 is thus in the lowered position and engages with its lower end in one of the blind holes 42 of the second gear 38. Thus, the second gear 38 is secured against rotation. By contrast, the head 78 of the locking bolt 66 is located on the upper switching level 60 of the switching ring 46, so that the first gear 24 can rotate. In this switching position of the grinding plate 28 is subjected to the operation of the grinding machine 10 of an eccentric movement and due to a force exerted on the first gear 24 by means of the second gear 38 positive drive a self-rotation.

At the in Fig. 2 shown switching position of the switching ring 46 in a rotational position in which both the head 76 of the locking bolt 64 and the head 78 of the locking bolt 66 rest on the upper switching level 60. Thus, neither the second gear 38 nor the first gear 24 is secured against rotation, so that the first gear 24 is in free-running with respect to its self-rotation. In this switching position, the sanding pad 28 is subjected to an eccentric movement during operation of the grinding machine 10, wherein the sanding pad 28 can rotate freely about its axis of rotation.

At the in Fig. 3 illustrated switching position is the head 76 of the locking bolt 64 on the upper switching level 60 and the head 78 of the locking bolt 66 on the lower switching level 62 of the switching ring 46. Thus, the locking bolt 66 engages in a bore 44 of the first gear 24, whereby the latter is secured against rotation. The diameter of the locking bolt 66 is less than that of the holes 44, so that the eccentric movements of the first gear 24 can be compensated for the armature shaft 14 during operation of the grinding machine. In this switching position of the sanding pad 28 is subjected during operation of the grinding machine 10 a vibratory grinding movement or a pure eccentric movement.

reference numeral

10

grinding machine

12

device housing

14

armature shaft

16

recess

18

eccentric

20

drilling

22

screw

24

gear

26

ball-bearing

28

sanding pad

30

switching device

32

casing

34

ring groove

36

plain bearing ring

38

gear

40

meshing area

42

drilling

44

drilling

46

switching ring

48

Handle

50

slot

52

recess

54

recess

56

slope

58

slope

60

upper switching level

62

lower switching level

64

locking bolt

66

locking bolt

68

feather

70

feather

72

slot

74

slot

76

head

78

head

Claims (12)

1. Portable power tool for sanding, polishing or the like, having a drive motor, a gearing coupled to the drive motor, and a sanding plate (28) operatively connected to the gearing, the gearing having a control device (30), by means of which the at least two types of movement of the sanding plate can be preselected, the control device (30) interacting with two intermeshing gears (24, 38), of which one (24) is connected to the sanding plate (28), and the control device comprising at least one locking pin (64, 66) which interacts with at least one aperture (42, 44) of the first gear (24) or the second gear (38), characterized in that the control device (30) has a first locking pin (64) for engaging in an aperture (44) of the first gear (24) and a second locking pin (66) for engaging in an aperture (42) of the second gear (38).
2. Portable power tool according to Claim 1, characterized in that, with at least one preselectable type of movement, an orbital movement of the sanding plate (28) is effected.
3. Portable power tool according to Claim 1 or 2, characterized in that, with at least one preselectable type of movement, independent rotation of the sanding plate (28) is effected.
4. Portable power tool according to one of Claims 1 to 3, characterized in that, with one preselectable type of movement, an orbital movement of the sanding plate (28) initiates independent rotation of the sanding plate (28).
5. Portable power tool according to Claim 1 or 2, characterized in that, with one preselectable type of movement, an orbital movement of the sanding plate (28) is effected and the sanding plate (28) is in a freewheeling mode with regard to its independent rotation.
6. Portable power tool according to Claim 1, characterized in that rotation of at least one of the gears (24, 38) can be stopped by means of the control device (30).
7. Portable power tool according to one of the preceding claims, characterized in that the gear (24) connected to the sanding plate (28) has an external tooth system, which meshes with an internal tooth system of the other gear (38).
8. Portable power tool according to Claim 7, characterized in that the gear (38) having the internal tooth system is arranged in a plain bearing ring (36).
9. Portable power tool according to Claim 1, characterized in that the control device (30) comprises a control ring (46), by means of which the at least one locking pin (64, 66) can be controlled.
10. Portable power tool according to Claim 9, characterized in that the at least one locking pin (64, 66) is guided in an axial, circular-arc-shaped aperture (52, 54) of the control ring (46).
11. Portable power tool according to Claim 10, characterized in that, in the region of the axial, circular-arc-shaped aperture (52, 54), the control ring (46) has a ramp-like slope (56, 58), by means of which the at least one locking pin (64, 66) can be axially displaced by rotating the control ring (46).
12. Portable power tool according to one of Claims 1 to 11, characterized in that the sanding plate (28) has a horizontal projection which has at least one straight boundary edge and at least one curved boundary edge.

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