EP1016504A2 - Electric power tool, especially an angle grinder - Google Patents

Abstract

The electric tool is provided with air suction slits (31), for the cooling of the electric motor (14), designed so that the air suction slits (31) are arranged at the second end of the motor housing (22). Facilities (72,76, fig.5) are provided for sealing the motor housing at its second end at the second end opposite the handle part (25). The handle part is rotatable, compared to the motor housing.

Description

The invention relates to a power tool, in particular an angle grinder, with an elongated motor housing in which a Electric motor is included, with a gear housing on one first end of the motor housing for receiving a transmission to drive a work spindle, with a handle part that is attached to a second end of the motor housing and in which a handle switch is arranged, and with air intake slots for cooling the electric motor.

Such a power tool, which is designed as an angle grinder is from the brochure "FEIN Power Tools 1997/98 "by the applicant and is known as MSfa666 distributed.

Such angle grinders are known as two-hand angle grinders in use, whereby with a back hand the Handle part is gripped in which a handle switch with a Switch button for activating the motor is provided, and will be held with a front hand on an additional handle, which is designed as a handle. With such angle grinders is from the fan of the electric motor cooling air Air intake slots sucked in, which are in the handle part in the immediate Located near the handle switch. This cooling air flows through the electric motor and occurs in the area of the gear head out of the device via suitable air outlet slots out.

Because such angle grinders are often used for rough work in strong contaminated environment must be used Danger that dust particles, Chips or the like are sucked in, resulting in a Damage to the power tool or at least to the detriment the life of the same can lead. So can dirt particles sucked in over time the function of the in the handle section provided affect the Soiling the electric motor or even impairing its function.

The object of the invention is therefore an electric tool to improve in accordance with the type mentioned at the beginning, that the risk of contamination of the power tool is reduced becomes.

This task is performed with a power tool according to the mentioned type according to the invention solved in that the air intake are arranged at the second end of the motor housing.

The object of the invention is completely achieved in this way. Because the air intake slots are no longer like conventional ones Power tools arranged in the area of the handle switch are soiled the handle switch and thus Functional impairment avoided. This will be additional still supported if, according to further training of the invention means for sealing the motor housing its second end are provided opposite the handle part.

In an additional development of the invention, the handle part arranged rotatably relative to the motor housing. By a such measure known per se in the prior art (compare DE 195 46 328 A1) it is made possible, for example a particularly ergonomic posture for an angle grinder for both rough grinding and cut grinding to take. Especially when such a rotatable handle part is provided, the arrangement of the invention Air intake slots outside the handle section in the motor housing from Special advantage, since otherwise dirt particles may be sucked in could heavily contaminate the twisting mechanism and to a difficult rotation of the handle part could lead to the motor housing.

According to a second variant of the invention, the object is at a power tool according to the type mentioned solved that at least in the flow area of the air intake slots a baffle plate for particle separation is provided.

In this way too, the object of the invention is accomplished solved. According to the invention, at least through the arrangement a baffle plate directly in the flow area of the Air intake slots separate dirt particles, chips and other impurities in the area of Air intake is reached, preventing the ingress of contaminants clearly in the sensitive areas of the power tool is reduced.

If such a design additionally with the previously explained Characteristics is combined, i.e. the air intake slots are arranged at the second end of the motor housing, is additional at the same time the risk of pollution for the in Handle part provided handle switch reduced.

In a further development of the invention, the baffle plate designed as a cooling plate for cooling electronic components.

This measure makes the baffle plate in two ways exploited, namely on the one hand to separate dirt particles and other contaminants and secondly for cooling of electronic components. This leads to a particularly favorable one Heat dissipation from electronic components provided in the power tool and thus to higher operational safety the same.

In an advantageous development of the invention, two are on each other opposite sides of the motor housing air intake slots provided, an insertion element with a base plate is provided, which is essentially over the cross section extends of the motor housing and at the air intake slots facing sides each provided a baffle plate is.

This measure has the advantage that a larger cross section for sucking in cooling air is available and at the same time due to the insert element, an inexpensive installation option for Electronic components in the cooling air area is guaranteed.

In an additional development of the invention, the motor housing has one on its end facing the handle circular passage for cable entry to the handle part, which is covered by the base plate of the insert element, with a sealing element for air sealing within the passage is provided.

This measure seals off the motor housing the handle part guaranteed even if this on Motor housing is rotatably received. With such a seal the ingress of dust and other dirt particles in the area of the handle switch located in the handle part avoided, which increases its operational safety becomes.

According to a further embodiment of the invention, the motor housing has a front and a rear engine housing part on the rear engine housing part the air intake slots and that contains at least one baffle.

By this measure, the construction and assembly of the Power tool significantly simplified.

Fig. 1

eine perspektivische Ansicht eines erfindungsgemäßen Elektrowerkzeuges am Beispiel eines Winkelschleifers;

Fig. 2

eine Ansicht des Elektrowerkzeuges gemäß Fig. 1, auf der lediglich das dem Griffteil zugewandte Ende des Motorgehäuses und das Griffteil erkennbar ist, wobei eine Gehäusehälfte des Griffteils abgenommen wurde;

Fig. 3

eine Explosionsdarstellung der rechten Gehäusehälfte des Griffteils mit Verriegelungstaste und zugehöriger Feder, sowie des Griffschalters, der mit dem Arretierungshebel zu einer Einheit montiert ist;

Fig. 4

eine Ansicht des Motorgehäuses vom Griffteil aus und

Fig. 5

eine Explosionsdarstellung des Motorgehäuses mit vorderem Motorgehäuseteil, hinterem Motorgehäuseteil und einem Einschubelement für das hintere Motorgehäuseteil nebst Zubehörteilen.

It goes without saying that the features of the invention mentioned above and those yet to be explained below can be used not only in the respectively specified combination but also in other combinations or on their own without departing from the scope of the invention. Further features and advantages of the invention result from the following description of a preferred exemplary embodiment with reference to the drawing. Show it:

Fig. 1

a perspective view of a power tool according to the invention using the example of an angle grinder;

Fig. 2

a view of the power tool according to FIG 1, on which only the end of the motor housing facing the handle part and the handle part can be seen, wherein a housing half of the handle part has been removed;

Fig. 3

an exploded view of the right housing half of the handle part with locking button and associated spring, and the handle switch, which is mounted with the locking lever to a unit;

Fig. 4

a view of the motor housing from the handle part and

Fig. 5

an exploded view of the motor housing with the front motor housing part, rear motor housing part and an insertion element for the rear motor housing part together with accessories.

1 shows a power tool according to the invention in perspective shown and designated overall by the number 10. The illustrated power tool 10 is a Angle grinder, the so-called two-hand angle grinder is executed and at its rear end has a handle part designated overall by the number 25, in which a handle switch is provided (see. Fig. 2). At the top A pushbutton 28 is provided at the end of the handle part Function will be explained in more detail below.

The power tool 10 further includes an overall number 22 designated engine case, which is a front engine case 23 for receiving an electric motor 14, and a rear Has motor housing part 24, on which the handle part 25th connects. The front engine housing part 23 closes a gear housing 12 in which a gear 16 for driving a work spindle is provided, which only with the number 18 is indicated schematically. On the left side of the gearbox 12 also shows a receptacle 20 in FIG which can be screwed in a handle-shaped additional handle, so that the power tool 10 with a front hand on the auxiliary handle and held on the grip part 25 with a rear hand can be. It goes without saying that on the opposite right side of the gear housing 12 another receptacle for the additional handle is provided so that the power tool 10 either for right-handed or left-handed operation suitable is.

In Fig. 1, the one basically provided for an angle grinder Protective hood not shown for the sake of clarity.

The grip part 25 has a first, left grip housing part 26 and a second, right handle housing part 27, whose function will be explained in more detail below.

The handle part 25 can be seen from that shown in Fig. 1 Basic position in which the handle button 33 according to FIG. 2 is down points twice to the left by an angle of 90 ° each, i.e. counterclockwise, twist and once out of the Fig. 1 shown basic position by 90 ° to the right, i.e. in the Turn clockwise.

Due to this twisting possibility, a switch between one Rough grinding, where a surface with a grinding wheel is worked flat, and between a separation, in which a workpiece with the end face of a cutting disc is severed. It can also be rotated the grip part 25 by 2 x 90 ° in one direction, i.e. So by 180 °, the handle switch on the top of the Turn the power tool 10. Such a grip position is especially for working on rough grinding on ceilings and Ceiling projections are an advantage.

The twisting mechanism that causes twisting of the grip part 25 compared to the motor housing 22 and a locking in the predetermined Angular positions enabled, will be closer in the following described with reference to FIGS. 2 to 4.

In Fig. 2, the grip part 25 is together with the rear motor housing part 24 shown enlarged in a view, wherein the left handle housing part 26 is removed so that the inner Structure, which is shown somewhat simplified, is recognizable.

The rear motor housing part 24 has an approximately circular Cross section on (see FIG. 4) and is at its front end, which can be assembled with the front engine housing part 23, cut obliquely downwards, so that there is an oblique Truncated cone results. On both sides of the rear engine case 24 is a plurality of air intake slots laterally 31 arranged one above the other and within the rear engine housing part 24 at a short distance from the air intake slots 31 each provided a baffle plate 30, the front End in Fig. 2 from the rear motor housing part 24 after protruding from the front. The function of these baffles 30 is explained in more detail below.

The rear motor housing part 24 has a central cylindrical Pin 44, which projects into the grip part 25. This pin 44 serves as a passage 62 (see FIG. 4) for implementation electrical cable 50 between the motor housing and the Handle part and also serves as a pivot bearing for rotatable mounting of the handle portion 25 on the rear engine housing part 24. Das rear motor housing part 24 has a handle part 25 facing End face 21 with which an annular flange 42 below Formation of an intermediate space 51 via radially extending webs 29 connected is. This ring flange 42 has a slightly smaller one Outside diameter as the rear engine housing part 24 its end face 21, but has a significantly larger Diameter than the coaxial pin 44.

The ring flange 42 has a total of four radial cutouts 43 on, each offset by an angle of 90 ° to each other are (see FIG. 4).

On these recesses 43, the grip part 25 is by means of a Locking lever 54 in the predetermined by the recesses 43 Angular positions with the rear engine case 24 lockable.

Furthermore, a locking lever 38 is provided which on a Pivot axis 37 is pivotally received and the first of the pivot axis 37 towards the front in the direction of the transmission housing 12 protruding part has the push button 28 on the front End a projection 41 is formed, which is in alignment Alignment with a recess 43 can be inserted therein. The locking lever 38 also has a second, rigid with the push button 28 connected part, which is approximately rectangular protrudes down to the push button 28 and the on his interacts with the handle switch 32.

The handle switch 32 has a handle button 33 on the rear lower end of the grip part 25 about a pivot axis 45 is pivotally fixed. The handle button 33 works with one Switch module 34 together, which is arranged above the handle button 33 is, the handle button 33 by a spring 36 after is biased at the bottom and against a movement upwards one arranged on the underside of the switch module 34 Switch pin 35 for switching the electric motor 14 on and off works.

The handle button 33 has on its front, the rear motor housing part 24 facing ends on the right and left each have an extension 59 through a crossbar 46 on the outer End connected to each other, so that overall at the front End of the handle button 43 an approximately rectangular recess is formed, in which the lower end of the second part 39 of the Locking lever 38 is movable by a certain amount.

At its lower end, the second part 39 of the locking lever 38 has a projection 48 which acts as a stop for the Cross bar 46 of the handle button 33 is used.

The locking lever 38 is by a spring 47 which on the second part 39 acts, biased such that the locking lever 38 in the illustration according to FIG. 2 clockwise is applied so that the push button 28 biased upwards is.

In the position shown in FIG. 2, the projection 41 is aligned the push button 28 with one of the recesses 43 so that the Push button 28 already by pressing into the activation position shown could be transferred. By impressing the push button 28 could handle 33 with its crossbar 46 on the projection 48 of the second part 39 of the locking lever over against the force of the spring 36 upwards can be moved so as to operate the switch module 34 to the Turn on power tool 10.

Once this position has been reached, the push button 28 be released because the locking lever swings back 38 under the action of the force of the spring 47 from its activation position is prevented in its rest position by that a front surface 49 of the second part 39 of the locking lever 38 strikes from the inside on the crossbar 46 of the handle button 33.

This results in a continuous operating position, in which only the handle button 33 must be kept tightened to to enable constant work with the power tool 10.

From this position shown in Fig. 2, the handle button 33 released, the handle button 33 moves under the action of the spring 36 down so that its crossbar 46 on the projection 48 of the second part 39 of the locking lever 38 is moved past and now the locking lever 38 from its activation position under the action of spring 47 pivoted into its rest position or starting position. Is assumed this position, the handle button 33 can not can be moved upward more because the crossbar 46 on the projection 48 of the second part 39 of the locking lever 38 strikes.

If the motor is to be switched on, the first must be Push button 28 are pressed, causing the locking lever 38 pivoted counterclockwise according to FIG. 2, see above that now the handle button 33 with its crossbar 46 on the projection 48 can be pivoted upwards to the Switch pin 35 of the switch module 34 to operate.

In Fig. 2 is also the locking lever at the lower end of the handle portion 25 54 recognizable, the one with a receptacle 58 Pivot axis 55 of the second or right handle housing part 27 is pivotally received (see also FIG. 3). This Locking lever 54 is biased by a spring 56 such that he aligns the handle portion 25 with one of the radial recesses 43 with a projection 57 in the relevant Recess 43 engages on the rear motor housing part 24 and the grip part 25 against rotation relative to the rear engine housing part 24 locks.

The locking lever 54 causes rotation of the Handle part 25 relative to the motor housing 22 is only possible then is when the locking lever 54 is pressed specifically. Subsequently the handle part 25 can be rotated until after one The locking lever can be turned by 90 ° or a multiple thereof 54 again with a radial recess 43 of the ring flange 42 is aligned and the projection 57 of the locking lever 54 under the action of the spring 56 with its projection 57 engages in the radial recess 43 of the ring flange 42 and the handle part 25 locked against further rotation. The function of locking the grip part 25 in one of the predetermined angular position on the motor housing 22 is on this Decoupled from the function of the push button 28, which as Switch-on lock to prevent the Serves electric motor.

The grip part 25 is through of both grip housing parts 26, 27 inwardly projecting webs 52, 53 on the pin 44 on the one hand and guided on the ring flange 42 on the other hand. As in 3 recognizable, the right handle housing part 27 has two to each other parallel ring webs 52 on which a first guide cause the surface of the pin 44, and also on its a plurality of ends facing the rear motor housing part 24 of circumferentially extending ring web sections 53 which in the space 51 between the end face 21 and the annular flange 42 intervene.

Since the ring flange 42 has individual radial ribs 29 connected to the end face 21 of the rear motor housing part 24 is, this results in a reduced contact area of the Web 53 and in connection with the parallel to each other Web 52, which rest on the pin 44, an extreme Reliable rotation guide for the handle part 25 on the rear motor housing part 24, but with a relatively low frictional resistance.

Between the handle part 25 and the rear motor housing part 24 a rotation angle limitation is also provided, which by a Projection 60 on the right handle housing part 27 (see FIG. 3) and by a radial rib 61 (see FIG. 4) on the rear motor housing part 24 is formed, which is between the pin 44th and the outer edge of the ring flange 42 extends. So that will it avoided that the grip part 25 in one direction by 360 ° or more can be rotated.

In Fig. 5 are the front motor housing part in an exploded view 23, the rear motor housing part 24 and an in the rear motor housing part 24 insertable insertion element 70 and accessories are shown and are described in more detail below explained.

The front motor housing part 23 serves to accommodate the electric motor 14. In contrast, in the rear engine housing part 24 that Insert element 70 is added, which consists of a Cross section of the motor housing part 24 extending base plate 72 exists, with the electronic components 74 for controlling the Power tool 10 are shed and on their left and on the right side an impact plate made of aluminum sheet 30 protrudes forward.

When operating the power tool 10 is via the louvers 31 on both sides of the rear engine housing part 24 cooling air sucked in, initially on the immediately behind the air intake vents 31 arranged baffle plates 30 hits what for Separation of dust particles and other contaminants leads, if necessary, when working in a heavily polluted environment could also be sucked in. (The air doesn't overflow Air slots shown in the area of the gear housing 12 out again). This arrangement has an advantageous effect on the service life of the electric motor 14. The baffles 30 are also at the same time as a heat sink for individual electronic components 74 trained so that these are sucked in by the Air flow can be cooled additionally. This contributes to operational security of electronic components 74.

While with conventional angle grinders, the air intake slots previously in the handle part 25, i.e. in the immediate vicinity of the Handle switch 32 were, the air intake slots 31 are now fluidically separated from the handle part 25 in the rear Motor housing part 24 is provided. The implementation 62 for the cable 50, which with a plug 68 for connection with provided corresponding connector pins 40 on the switch module 34 are (see FIG. 3) through the base plate 72 of the insertion element 70 largely closed. In addition, it is elastic Sealing disc 76 is provided, which is attached to the cable 50 and together with these within the passage 62nd of the pin 44 is in addition to this at a To seal rotation of the grip part 25.

In this way it is avoided that polluted air in the Area of the handle switch 32 arrives and thus its function impaired prematurely.

The fact that the motor housing 22 in two parts with a front Engine housing part 23 and a rear motor housing part 24 are formed is the manufacture and assembly is greatly simplified. Insert element 70 with the electronic components 74 and the flapper 30 is in the rear engine case 24 used, while the electric motor 14 in the front motor housing part 23 is mounted; then both components by screwing in screws in the rear part of the engine housing 24 screw holes 64 in screw receptacles 66 in the form of pins on the front motor housing part 23 firmly together connected.

Claims (8)

Power tool, in particular angle grinder (10), with an elongated motor housing (22) in which an electric motor (14) is received, with a gear housing (12) at a first end of the motor housing (22) for receiving a gear (16) for driving a work spindle (18), with a handle part (25) at a second end the motor housing (22) is fixed and in which a handle switch (32) is arranged, and with air intake slots (31) for cooling the electric motor (14), characterized in that that the air intake slots (31) at the second end of the motor housing (22) are arranged. Power tool according to claim 1, characterized in that means (72, 76) for sealing the motor housing (22) provided at its second end opposite the handle part (25) are. Power tool according to claim 1 or 2, characterized in that that the handle part (25) relative to the motor housing (22) is rotatable. Power tool, especially angle grinder after a of the preceding claims, with an elongated motor housing (22) in which an electric motor (14) is added with a gear housing (12) at a first end of the motor housing (22) for receiving a gear (16) for driving a work spindle (18), with a handle part (25) attached to a second end of the motor housing (22) and in which a handle switch (32) is arranged is, and with air intake slots (31) for cooling the Electric motor (14), characterized in that in the flow area the air intake slots (31) at least one Baffle plate (30) is provided for particle deflection. Power tool according to claim 4, characterized in that the baffle plate (30) as a cooling plate for cooling Electronic components (74) is formed. Power tool according to claim 4 or 5, characterized in that on two opposite sides the motor housing (22) air intake slots (31) are provided are that an insertion element (70) with a base plate (72) is provided, which is essentially over the Cross section of the motor housing (22) extends and at the the air intake slots (31) facing sides each Baffle plate (30) is provided. Power tool according to one of claims 4 to 6, characterized characterized in that the motor housing (22) at its the Handle part (25) facing end face (21) a circular Passage (62) for cable entry to the handle (25) through the base plate (72) of the insertion element (70) is covered and that within the Passages (62) a sealing element (76) for air sealing is provided. Power tool according to one of the preceding claims, characterized in that the motor housing (22) a front (23) and a rear (24) engine housing part has, wherein the rear motor housing part (24) Air intake slots (31) and the at least one baffle plate (30) contains.

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