CN1636675B - hand tool machine - Google Patents

Abstract

A hand-held power tool (10) has a housing (12), on the underside of which a grinding disk (30) carrying a grinding disk (56) and drivable by an electric motor via an angle drive (37) is movably mounted, wherein the angle drive (37) is formed by an eccentric (34) which drives a pivot lever (42) in a reciprocating manner about a pivot axis (44). The pivot axis (44) runs parallel to the grinding plate (30), wherein the pivot lever (42) is designed as an angle lever, one lever arm of which reciprocates up and down about the pivot axis (44) and the other lever arm of which is angled downward and transmits a reciprocating movement in the horizontal direction back and forth to the grinding plate (30) or to a further tool.

Description

hand tool machine

technical field

The invention relates to a hand-held power tool.

Background technique

EP 0 224 465 discloses a hand-held power tool in which the rotational movement of a drive motor is converted into a rotational pivoting movement of its output shaft. Simultaneously, a grinding tool, such as a grinding disc, connected together with the output shaft performs a rotational oscillating motion synchronously with the output shaft. This movement has a defined frequency and a defined reciprocating rotational path, which makes the operation of the power tool and the control of the tool guide reliable and precise. Here, the tool cannot obtain the linear motion produced by the electric motor.

Contents of the invention

According to the invention, a hand-held power tool is proposed, which has a housing, on the underside of which is movably mounted a grinding disc-carrying device that can be driven by an electric motor via an angular drive (Winkelgetriebe). Grinding disc or other tool that can be driven reciprocatingly, wherein the angular transmission device consists of a swing rod and an eccentric that drives the swing rod to reciprocate around a swing axis, wherein the swing axis is parallel to the grinding disc or said other tool extensions, wherein the swing lever is constructed as an angled lever, one arm of which reciprocates up and down about a swing axis, and the other arm of which deflects downward at an angle and transmits the horizontal back and forth reciprocating motion to Grinding discs or said other tools, wherein said one arm of the swing lever is formed by a ring pivotably mounted about its pivot axis, the circumference of which is at one point movably connected to said The drive eccentric is connected, at another point, to the grinding disc or the other tool in a force-transmittable manner.

According to the invention, an angular transmission for a hand-held power tool is also proposed, which converts the rotational motion of an electric motor into a pivoting motion of a motion transmission element and transmits it to a working part), wherein the motion transmission element Mounted so as to be pivotable about a pivot axis parallel to a virtual workpiece surface, the pivotal movement of the motion transmission element can be converted into a linear reciprocating movement of the working part.

The invention has the advantage that a particularly compact and cost-effective hand-held power tool is provided which has a linearly driven grinding wheel or other reciprocatingly driven tool.

The downwardly deflected lever arm can be positively connected to the grinding wheel or to another tool, so that the angular drive requires little installation space and the hand-held power tool is particularly compact.

The pendulum of the angular transmission device consists of a ring that can swing around its central axis, the circumference of which can be connected to a drive eccentric in a position that transmits motion, and in another position that is deflected by 90° relative to this position. The positional force-transmitting connection to the grinding disc or other reciprocatingly drivable tool means that the angle drive is formed particularly inexpensively from a simple, robust standard part.

The ring is arranged vertically in the housing with its plane parallel to the feed direction of the hand-held power tool, through which the movement transmission for the linear drive of the tool is achieved with a small number of components.

The outer ring of a rolling bearing is used as the ring, by means of which the mounting of the ring can be realized particularly simply.

There is a positive fit not only between the ring and the grinding disc, but also between the ring and the eccentric, wherein the part of the ring which is deflected downwards by 90° has a projection which engages on the grinding disc or other A recess of the tool forms a particularly compact and robust angular drive.

The insertion opening is arranged in an elongated pressure plate, in particular made of metal, which is placed inside or fastened to the grinding disc or other tool, whereby the hand-held power tool is particularly robust.

Between the grinding disc and the housing there are coupling means, in particular a second eccentric, which are supported on the one hand on the housing, in particular in a corresponding opening, and on the other hand on the grinding disc, in particular In an insertion opening, in particular, the oscillating movement of the grinding disc or other tool is converted into a defined orbital movement, through which the tool can acquire a particularly effective movement for grinding or scraping.

Between the grinding disc and the housing there is a coupling device, in particular a projection, which bears on the housing on the one hand, in particular in a corresponding opening, and on the other hand on the grinding disc, in particular in the A longitudinal groove stabilizes the oscillating movement of the grinding disc or other tool, whereby the direction of movement of the tool is particularly stabilized when the tool is driven linearly.

The coupling between the grinding wheel and the housing not only generates an orbital movement, but also prevents rotation, in particular as a longitudinal guide, resulting in a particularly versatile hand-held power tool.

The motion transmission element is pivotably mounted about a pivot axis parallel to the imaginary workpiece surface, wherein the pivot motion of the motion transmission element can be converted into a linear reciprocating motion of the drive element, whereby a particularly compact device for rotating An angular drive that converts motion into reciprocating motion can also be used in other machines.

Description of drawings

The present invention will be further explained below with the aid of an embodiment in conjunction with the accompanying drawings. The accompanying drawings indicate:

Figure 1 A side partial longitudinal sectional view of the hand-held machine tool,

Figure 2 A transverse sectional view of the hand-held machine tool shown in Figure 1,

Figure 3 According to a horizontal partial longitudinal sectional view of Figure 1,

Figure 4 is a three-dimensional schematic diagram of the angle transmission device of the hand-held machine tool,

Fig. 5 The bottom view of the grinding disc of the handheld machine tool,

Fig. 6 The bottom view of the grinding disc of the handheld machine tool,

Fig. 7 Bottom view of another grinding disc of the hand tool machine.

Detailed ways

FIG. 1 shows a side sectional view of an electric storage superfinishing machine 10 with a flat, narrow, box-shaped housing 12 . It serves as a handle, and the operating hand is placed on the upper surface 11 of the housing 12 in such a way that the front side 14 of the housing points in the feed direction and a switch key 16 located on the front side 14 of the housing 12 can be comfortably Touch it with your hands. An electrical on and off switch 17 located in the housing 12 can be actuated via this switch key 16 .

On the back side 18 of the casing 12, two insertion openings 20 are arranged parallel to the upper surface 11 for the insertion of two accumulators. . Arranged within the housing 12 is an electric motor 24 , in particular a DC motor, which is mounted in a base 26 . The base 26 is coupled downwardly via an elastic support ring 28 to a grinding disc 30 which engages in its grinding disc 31 so that it cannot be lost.

Viewed from the viewing direction, a motor shaft 32 protrudes to the right from the motor 24, a first eccentric 34 is fixed on the motor shaft in a non-rotatable manner, and an eccentric pin 36 is mounted on its free end. The eccentric pin together with a roller bearing 42 , which is at least partially rotatably mounted in the base 26 , form a novel angular transmission 37 . To this end, the eccentric pin 36 engages in a transverse groove 38 of the outer ring 40 of the rolling bearing 42 , so that the outer ring 40 can be driven upwards or downwards by a small rotational angle relative to the inner ring 41 .

The inner ring 41 is fixedly connected to the base 26 via a bearing shaft 44 relative to the housing. On the outer ring 40 there is a projection 46 pointing downwards as seen in the viewing direction, which engages in an engagement opening 48 on the grinding disc 31 or on an elongated pressure plate 29 which mechanically reinforces the grinding disc . The insertion opening 48 can be formed as a circular bore, so that the cam 46 oscillating clockwise and counterclockwise as seen in the viewing direction drives the grinding wheel 30 in a linear drive towards the front side 14 or towards the rear side 18 .

Arranged on the left side towards the rear side 18 as seen in the viewing direction is a second eccentric 49 which has a balancing mass 50 whose upper pin 51 protrudes upwards into an insertion opening 55 which is fixed relative to the housing. , its eccentric pin shaft 52 is embedded downwards in another embedding opening 54 on the grinding sheet 31 or on the elongated pressing plate 29 . The eccentric 49 is excited by the reciprocating movement of the grinding disc 30 to impart an orbital movement to the rear area of the grinding disc, in such a way that the eccentric 49 forms a passive eccentric drive for the battery-operated grinding device 10 .

The grinding disc 30 has an elastic grinding pad 35 on its grinding base 31 made of hard elastic material, which has a hook and loop fastener 58 on the underside, a fleece back of a grinding blade 56 Can be adhesively fixed on the hook and loop.

Fig. 2 shows a cross-section of the electric storage superfinishing device 10, wherein clearly shows two accumulators 22 arranged parallel to the upper surface 11 of the housing 12, in addition clearly shows the connection with the accumulators 22 and an electric motor 24 arranged parallel to the grinding disc 30 . It can also be seen that the support ring 28 extends along the longitudinal side inside the housing 12 and serves as an elastic suspension of the grinding wheel 30 relative to the base 26 . In addition, it can be seen that on the upper surface of the elastic, firm grinding base 31 of the grinding disc 30, an elongated pressure plate 29 for force transmission or reinforcement of the grinding disc 30 is arranged, the first eccentric 34 The eccentric pin 36 and the eccentric pin shaft 52 of the second eccentric 49 are force-transmittingly embedded in the elongated pressure plate.

FIG. 3 shows a horizontal longitudinal sectional view according to FIG. 1 , the housing 12 of the accumulator superfinishing device 10 is constructed as a narrow elongated box, which houses inside it the The motor 24 , the motor causes the outer ring 40 of the rolling bearing 42 to rotate and swing through the eccentric 34 , and the protrusion 46 of the outer ring is inserted into the insertion opening 48 of the elongated pressing plate 29 .

The arrangement of the bearing shaft 44 of the rolling bearing 42 and its bearing position on the base 26 can also be clearly seen. It can furthermore be seen that the outer ring 40 of the rolling bearing 42 has a transverse groove 38 into which the eccentric pin 36 of the first eccentric 34 engages, so that its circular motion is converted into a linear reciprocating motion of the outer ring 40 .

In the region of the rear side 18 of the housing 12 , a second eccentric 49 can be seen, the eccentric pin 52 of which engages in the engagement opening 54 of the elongated pressure plate 29 of the grinding wheel 31 .

The passive pivotal drive of the grinding disc 30 by the second eccentric 49 is brought about by the reciprocating movement of the grinding disc 30 driven by the first eccentric 34 . Here, the grinding disc 30 acts like a connecting rod and the second eccentric 49 acts like a crankshaft. The interaction of these two movements is coordinated structurally so that a defined linear path of the grinding wheel 30 produces a defined rotational path of the eccentric 50 and thus a defined orbital movement of the grinding wheel 30 .

In order to avoid a dead center fixed position of the second eccentric 50, at least one of its supports remains elastic, so that the eccentric 50 can occupy an inclined position from which it can always easily move the first eccentric The promotion of 34 is transformed into a circular motion.

However, it is also possible to elastically prestress the grinding disc 30 at the side relative to the housing 12, so that the rear end of the grinding disc 30 always tries to pivot laterally relative to the housing 12 in such a way that the eccentric 50 does not remain suspended. Instead of a straight dead center position, it is always deflected laterally and can thus be actuated with a straight stroke.

In the rear region of the accumulator superfinishing device 10, instead of the eccentric 49, a straight pin fixed relative to the housing can engage in a groove arranged as a longitudinal guide on the elongated pressure plate 29, which instead of The circular insertion opening 54 provided on the eccentric pin shaft 52 .

In this way, the grinding disc 30 is forced to carry out a rectilinear pivoting movement which is linearly guided back and forth, without additional orbital movement.

The rolling bearing 42 shown in detail in FIG. 4 is the core part of the new angular transmission device 37, and its outer ring 40 has an upwardly directed, radially erected projection 46, looking at the outer ring 40 in the viewing direction. The transverse groove 38 of the first eccentric device 34 is deflected to the left, and the eccentric pin 36 of the first eccentric device 34 is embedded in the transverse groove so that its eccentric circular motion is converted into a back-and-forth reciprocating rotary swinging motion of the outer ring 40, thereby being converted into a lug 46 reciprocating rotary swinging motions.

The outer ring 40 has a further transverse groove 382 on its underside in the viewing direction, by means of which the rolling bearing 42 can be inserted into a different eccentric according to the design application requirements, or the first transverse groove 38 can be worn In the case of , the first transverse groove is replaced by rotating the outer ring.

The cam 46 for driving the grinding disc 30 is spherical so that it contacts as large a surface as possible when inserted into the insertion opening 48 , so that wear is reduced.

In an unshown embodiment of this novel angle transmission device, the rolling bearing 42 can also be rotated 90° around its transverse axis, at this time, an axially erected projection must be provided on its outer ring 40 , which is used to convert the rotational swing motion of the outer ring 40 into the linear motion of the part to be driven.

FIG. 5 shows a bottom view of a grinding disc 301 of iron-shaped configuration, on which either a single-piece, identically shaped grinding disc or a multi-part Assembled abrasive discs with approximately coincident contours.

Figure 6 shows an iron-shaped grinding disc 56 consisting of two parts 561, 562, i.e. an equilateral triangle with arched outer edges and one connected to it separated by a predetermined breaking line 563. The remainder of the composition.

FIG. 7 shows another iron-shaped grinding disc 302, which has through-holes 60 arranged on a pitch circle for sucking out dust, and a separate diamond-shaped tip section 313, which can be Interchangeable with the tip section of the same type, which can be adhered to the Velcro fastener, this tip section is the point of greatest wear of the grinding disc and thus may need to be renewed more frequently than the rest of the grinding disc.

Claims (17)

1. A hand-held power tool (10), having a housing (12), on the lower side of the housing, a grinding blade (56) is movably mounted, which can pass through an angle transmission device (37) ) a grinding disc (30) driven by an electric motor or a reciprocatingly driven other cutter, wherein the angular drive (37) consists of a swing lever (42) and a drive that drives the swing lever (42) around a swing axis (44) A reciprocating eccentric (34) is formed, wherein the pivot axis (44) extends parallel to the grinding disc (30) or said other tool, wherein the pivot lever (42) is configured as an angle lever, its One lever arm reciprocates up and down around the swing axis (44), and its other lever arm is angled downwards and transmits the horizontal back and forth reciprocating motion to the grinding disc (30) or said other tool, characterized by In that, the said one arm of the rocker (42) consists of a ring (40) which is mounted pivotably about its pivot axis (44), the circumference of which is in a position transferable to the eccentric It is connected to the grinding disc (30) or to the other tool at another position in a force-transmitting manner. 2 . The hand-held power tool as claimed in claim 1 , characterized in that the downwardly angled lever arm is positively connected to the grinding wheel ( 30 ) or the other tool. 3 . 3. The hand-held power tool as claimed in claim 2, characterized in that the ring (40) is arranged vertically in the housing (12), the plane of which extends parallel to the feed direction of the hand-held power tool. 4. The hand-held power tool as claimed in claim 2 or 3, characterized in that the ring (40) is an outer ring of a rolling bearing (42). 5. The hand-held power tool according to claim 2 or 3, characterized in that not only between the ring (40) and the grinding disc (30) but also between the ring (40) and the eccentric (34) All have a positive fit, wherein the part of the ring that is deflected downward by 90° has a projection (46) that fits into the insertion opening (48) of the grinding disc (30) or of the other tool )middle. 6. The hand-held power tool as claimed in claim 5, characterized in that the insertion opening (48) is arranged in an elongated pressure plate which is located in the other tool or grinding disc (30) or is fixed On said grinding disc (30) or said other tool. 7. The hand-held power tool according to claim 1, characterized in that coupling devices are arranged between the grinding disc (30) or the other tool and the housing (12), which are supported on the one hand on on the housing (12), on the other hand it bears on the grinding disc (30) or said other tool and converts the oscillating motion of said grinding disc (30) or said other tool into a defined orbital motion . 8. The hand-held power tool as claimed in claim 7, characterized in that the coupling device is a second eccentric (49). 9. The hand-held power tool as claimed in claim 7, characterized in that the coupling device is mounted on the housing (12) in a corresponding opening (55). 10. The hand-held power tool according to claim 7, characterized in that the coupling device is mounted on the grinding disc (30) in an insertion opening (54). 11. The hand-held power tool according to claim 7, characterized in that coupling devices are arranged between the grinding disc (30) and the housing (12), which are supported on the one hand on the housing (12) On the other hand, it is supported on the grinding disc (30) and stabilizes the oscillating movement of the grinding disc (30). 12. The hand-held power tool as recited in claim 11, wherein the coupling device is a cam. 13. The hand-held power tool as claimed in claim 11, characterized in that the coupling device is mounted on the housing (12) in a corresponding opening (55). 14. The hand-held power tool as claimed in claim 11, characterized in that the coupling device is mounted on the grinding disc (30) in a longitudinal groove. 15. The hand power tool as recited in claim 1, wherein the other position is offset by 90° relative to the one position. 16. The hand-held power tool of claim 6, wherein the elongated pressure plate is made of metal. 17. Angle transmission (37) for a hand-held power tool, characterized in that it is designed according to an angle transmission as claimed in one of claims 1 to 16.

Images