EP1740348A1

EP1740348A1 - Manual grinding tool

Info

Publication number: EP1740348A1
Application number: EP05740574A
Authority: EP
Inventors: Stephan Rieth
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-03-31
Filing date: 2005-03-30
Publication date: 2007-01-10
Also published as: KR20060133060A; CN1950177B; DE102004040900A1; WO2005095052A1; CN1950177A; US20080045126A1

Abstract

The invention relates to a manual grinding tool comprising a rotating grinding head (7). The inventive grinding device is characterised by a guiding device that is connected to the grinding tool (8) and can be applied to a workpiece (19) in a sliding and/or rolling manner. The grinding head (7) assumes a fixed position in terms of the guiding device which is used to press the grinding tool against the workpiece (19) in at least one direction without tilting.

Description

Description:

"Handschleifvomchtung"

The invention relates to a hand grinding device with a rotating grinding head.

In conventional such grinders with unilaterally stored grinding ^* - head incumbent on the user to the grinding head through his arm movements un "d exercise appropriate holding and pressing forces to conduct as precisely as possible. In order to achieve a high material removal rate, high contact forces are required, the exercise of which runs counter to precise guidance of the grinding head.

The invention has for its object to provide a new grinding device of the type mentioned, which allows workpieces to be machined more precisely at high material removal speed.

The grinding device according to the invention which achieves this object is characterized by a guide device connected to the device, which can be slidably or / and rollingly against a workpiece, in relation to which the grinding head assumes a fixed position and by which the device against the workpiece in at least one direction can be pressed against tilting.

Advantageously, the grinding head of such a device can be guided precisely against the workpiece with a large contact pressure by keeping the axis of rotation of the grinding head stable in at least one direction, the guide device providing degrees of freedom for moving the device by hand in the feed direction of the grinding head and possibly in the direction of delivery that is decisive for the removal depth. The guide device can preferably be pressed against the workpiece with at least three contact points in a tilt-stable manner, so that the grinding head can be guided with a constant inclination with respect to a workpiece surface. The contact points can lie in one plane according to a flat workpiece surface. However, it is also conceivable to place the guide device with three contact points against the outer surface of a cylindrical workpiece, the outer surface or end edge of which is to be machined.

In one embodiment of the invention, the guide device has a contact surface adapted to a workpiece surface, e.g. a flat contact surface that can be placed on one side of a plate-shaped workpiece.

In one embodiment of the invention said workpiece surface abuts a workpiece edge and the grinding head is provided for machining the workpiece edge and / or an edge surface of the workpiece adjacent to the workpiece edge, e.g. an edge surface of a workpiece plate.

In the latter embodiment, the contact surface can e.g. be formed by an annular surface coaxial to the grinding head. As a guide device would also be conceivable a roller with an axis of rotation perpendicular to the axis of rotation of the grinding head, the roller rolling on the workpiece surface adjacent to the edge surface.

The user of the device can exert a contact pressure in such a direction that one component acts on the workpiece surface mentioned and the other component acts on the edge surface to be removed via the grinding head. In particular, due to the component acting on the workpiece surface, the device is held in a tilt-stable manner on the workpiece and can be guided precisely with a large pressing force.

The guide device can further comprise a stop element for bearing against the edge surface. Such a measure can advantageously limit the maximum material removal. In an alternative embodiment, the grinding head is arranged between a plurality of stop elements provided for abutment against a workpiece surface. Such a device can be used for grinding the workpiece surface, the stop elements having different heights can have that the axis of rotation of the grinding head is at a desired angle to the workpiece surface when the stop elements bear against the workpiece surface. In the case of a conical surface of the grinding head, it can thus be ensured that the closest surface line of the grinding head always runs parallel or tangentially to the surface mentioned. Such a grinding device can advantageously be used for the removal of workpiece surfaces from protruding weld seams.

In a further embodiment of the invention, the guide device can be on opposite sides of a workpiece, e.g. a plate or a tube, attacking stop elements, wherein at least one of the stop elements is movable, on the one hand to facilitate the introduction of the workpiece into the space between the stop elements and on the other hand to be able to adapt the guide device to different workpiece thicknesses.

The guide device can be adjustable and, in particular for setting different angles of bevels to be ground, can be pivoted about an axis and locked in the desired pivot positions.

The invention is explained in more detail below with the aid of exemplary embodiments and the accompanying drawings relating to these exemplary embodiments. Show it:

Fig. 1 shows a first embodiment for a grinding device according to the invention with a conical grinding head and an annular guide device, Fig. 2 shows a second embodiment for a grinding device according to the invention with a cylindrical grinding head and an annular guide device, Fig. 3 shows a third embodiment for 4 shows a fourth embodiment of a grinding device according to the invention with a guide device according to FIG. 3 and a conical grinding head, FIG. 5 shows a fifth embodiment for a grinding device according to the invention with a guide device which can be pivoted in its entirety, 6 shows a sixth exemplary embodiment of a grinding device according to the invention with a grinding head arranged between stop elements of a guide device,

7 shows a seventh exemplary embodiment for a grinding device according to the invention, and

8 shows another embodiment for a grinding device according to the invention.

A hand grinding device has a housing 1 for a motor / transmission unit (not visible in the figures), a handle 2 with a switch button 3 and a retaining bracket 4 on the end of the housing facing away from the handle.

A shaft 18 connected to the motor / gear unit is rotatable about an axis 6 in a housing extension 5 extending at right angles to the longitudinal axis of the housing. At its end facing away from the housing 1, the shaft 18 is connected to a grinding head 7.

The grinding head 7 is coaxially surrounded by an annular stop 8 forming a guide with a flat stop surface 15. The housing attachment 5 has a section 9 which comprises the stop 8 and which can be screwed onto the rest of the grinding device. By rotating the section 9, the stop 8 can be axially adjusted and locked by a ring nut 16. Another ring nut 17 is used to connect the grinding head 7 to the shaft 18.

As shown in FIG. 1, a bevel can be ground to an edge 20 of a plate-shaped workpiece 19 with the aid of the grinding device. By adjusting the ring stop 8 in the direction of the axis ό, the point of attack or the area of attack on the grinding head 7 can be shifted, thereby achieving a uniform wear of the conical grinding surface of the grinding head.

To adjust the guide or the stop 8 in the direction of the axis of rotation 6 of the grinding head 7, the section 9 could also be guided against rotation and axially coupled to a freely rotatable threaded nut.

For the purpose of uniform wear of the grinding surface of the grinding head, the guide or the stop 8 could oscillate in the direction of the grinding head axis of rotation 6. A separate drive motor or could be used for oscillating adjustment Pneumatic cylinders can be provided. However, an adjustment drive could also be connected to the drive of the grinding head 7, for example via a planetary or worm gear. The section 9 can be provided with a meandering circumferential groove, in which a guide pin or a roller connected to the drive device engages, so that the circumferential guide pin or the circumferential roller pushes the non-rotatably guided section 9 back and forth. 8 shows a further embodiment with an oscillating grinding head.

When grinding, the user presses the flat contact surface 15 of the ring stop 8 obliquely against the plate surface of the workpiece 19 adjoining the edge 20. A component of the pressing force parallel to the plate surface ensures the desired material removal by the grinding head. A component of the pressing force that is perpendicular to the plate surface ensures a tilt-stable guidance of the grinding head 7, the axis of rotation 6 of which is only displaced in parallel during grinding processing while maintaining its spatial direction. Increasing the contact pressure advantageously leads to an increase in both the material removal rate and the tilting moment, so that the device can be safely guided even with a large contact force and high removal rate.

The ring shape of the stop 8 makes the device particularly suitable for machining concave workpiece edges.

The grinding head 7 is described in detail in DE 102004016565.3, which is included here.

In the following figures, parts that are the same or have the same effect are designated with the same reference number as in FIG. 1, the relevant reference number being accompanied by the letter a, b etc. The grinding device of FIG. 2 differs from the preceding grinding device in that a cylindrical grinding head 7a is provided instead of a conical grinding head 7. With the aid of this device, an edge surface H of a workpiece 19a can be machined. This grinding device can also be safely guided with a large pressing force, a component of the pressing force perpendicular to the plate surface of the workpiece 19a ensuring tilt stability of the axis of rotation of the grinding head and a component parallel to the plate surface ensuring the desired material removal. A hand grinding device shown in FIG. 3 with a housing 1 b has a disk-shaped grinding head 7 b. A support 10, which is connected to a first stop element 11 and a second stop element 12, is attached to a housing attachment 5b as part of a guide device 8b. The stop elements 11 and 12 engage on opposite sides on a workpiece 19b such that they can move in a rolling manner via rotatably mounted balls 26.

The stop element 12 is adjustable to adapt to different workpiece plate thicknesses with the aid of a lockable set screw 21. The stop element 12 also has a cantilever 22 with a stop roller 23. The stop roller 23 can be placed with a conical surface 24 against an edge surface 14b of the workpiece 19b.

By means of the guide device 8b, the grinding device can be held in a tilt-stable manner in relation to the plate surfaces of the workpiece 19b at a desired angle. By moving the device perpendicular to the plane of the paper, the device can be used to grind a chamfer on an edge 20b of the workpiece 19b, the grinding device being tilted relative to the position shown in FIG. 3, so that the grinding wheel 7b is at an angle to the edge 20b in the feed direction stands.

In the exemplary embodiment of FIG. 4, the grinding takes place in such a tilted position that the grinding surface line of a conical grinding head 7c runs parallel to a workpiece edge 20c.

In the exemplary embodiment in FIG. 5, a guide device 8d is designed similarly to the embodiment in accordance with FIGS. 3 and 4. However, the entire guide device 8d can be rotated about an axis 25 and locked in the desired rotational positions. A stop element 12d can be pivoted about an axis 27 with the aid of levers 26. The levers 26 are attached to fork legs 28, between which a grinding head 7d is arranged, which engages in a recess in a stop element 11d. In the stop position of the stop element 12d shown in FIG. 5, the levers 26 engage in a guide 29 in the relevant fork leg 28, as a result of which rotation of the stop element 12d about the axis 27 is blocked. In this position the force of a plate spring 30 acts on the stop element 12d. The contact pressure can be adjusted by the helical spring 30 by means of a knurled nut 31.

With the aid of the device shown in FIG. 5, depending on the pivoting position of the guide device 8d, bevels 20d on workpieces 1d can be ground at different angles.

A hand-held grinding device shown in FIG. 6 has a guide device 8e, which is provided for attachment to a flat surface 32 of a workpiece 19e.

The guide device 8e consists of a support plate 33 connected to a housing extension 5e of the grinding device, from which stop elements 34 and 35 protrude in the form of elongated support feet of different heights. A grinding head 7e with a conical grinding surface is arranged between the stop elements 34 and 35 provided with rollers 36. The height difference between the stop elements 34, 35 is dimensioned such that the respective surface line closest to the workpiece 19e of the conical grinding surface of the grinding head 7e runs parallel to the surface 32.

The grinding head 7e could be displaceable against the rest of the device and acted upon by a spring in such a way that the contact pressure of the grinding head against the workpiece increases by increasing the contact pressure of the device on the surface 32.

6, a weld seam 37 protruding from the surface 32 can advantageously be ground off, the guide device 8e leading the grinding head 7e parallel to the surface 32. In addition, the rollers 36 provide linear guidance along the weld 37.

A grinding device shown in FIG. 7 with a grinding head 7f has a guide device 8f with two rollers 38 and 39. The rollers are attached at one end to a support plate 40 which is perpendicular to the roller axis and which in turn is connected to a holder 41 which can be pivoted about an axis 25f and locked in the desired pivot positions. The holder 41 can be varied in length to adjust the grinding point. The device can be used to machine an end edge of a tubular workpiece 42, the rollers 38 and 39 of the guide device 8f rolling on the outer and inner jacket of the tube piece, while the carrier plate 40 lies against the end of the tube piece. By swiveling the guide device 8f, a bevel angle to be ground can be set, and by adjusting the length of the holder 41, the grinding point on the conical grinding surface of the grinding head 7f can vary.

The workpiece 42 has sufficient play between the rollers 38 and 39 in order to be able to pivot the device for varying the infeed and thus the removal depth.

Instead of two rollers, four rollers could also be attached to a carrier plate and the grinding head displaceable relative to the carrier plate in order to vary the infeed.

In an exemplary embodiment shown in FIG. 8, a drive shaft 18g for a grinding head 7g is connected to a transmission 51 via a drive belt 50. A gear 52 attached to the gear 51 on the output side engages with a gear 53 which is connected to a bushing part 9g. The socket part 9g is rotatably supported at 54 on a housing extension 5g. Another socket part 55, which is arranged between the socket part 9g and the housing extension 5g and is connected to a ring stop 8g, has a curved annular groove 56 into which a cam 57 protruding inwards from the socket part 9g engages. Noses 59 protruding inwards from the socket part 55 engage in longitudinal grooves 60 in the housing extension 5g to form an anti-rotation device.

The gear 51 reduces the speed of the drive shaft 18g to a few revolutions per minute. The cam 57 of the socket part 9g driven via the gear wheels 52 and 53 displaces the further socket part 55 axially according to arrow 58, so that the ring stop 8g executes an oscillating movement.

Claims

claims:

1. Hand grinding device with a rotating grinding head (7), characterized by a guide device (8) connected to the device and slidingly and / or rolling against a workpiece (19), with respect to which the grinding head (7) has a fixed position occupies and through which the device can be pressed against the workpiece (19) in a tilt-stable manner.

2. Grinding device according to claim 1, characterized in that the guide device (8) can be pressed against the workpiece (19) in two directions in a tilt-stable manner at at least three contact points.

3. Grinding device according to claim 1 or 2, characterized in that the guide device (8) has a contact surface (15) adapted to a surface of a workpiece (19).

4. Grinding device according to claim 3, characterized in that the surface of the workpiece (19) adjoins an edge (20) of the workpiece (19) and the grinding head (7) for processing the edge (20) and / or one on the workpiece edge adjacent edge surface (14) of the workpiece (19a) is provided.

5. Grinding device according to claim 4, characterized in that the guide device (8b) comprises a stop element (23) for abutment against the edge surface (14b).

6. Grinding device according to one of claims 3 to 5, characterized in that the contact surface (15) is formed by an annular surface coaxial to the grinding head (7).

7. Grinding device according to one of claims 1 to 3, characterized in that the grinding head (7e) is arranged between a plurality of stop elements (34, 35) of the guide device (8e) provided for abutment against a workpiece surface (32).

8. Grinding device according to claim 7, characterized in that the stop elements (34, 35) have different heights and the axis of rotation of the grinding head (7e) when the stop elements (34, 35) bear against the workpiece surface (32) to the workpiece surface (32 ) is at a desired angle.

9. Grinding device according to one of claims 1 to 3, characterized in that the guide device (8b-8d) on opposite sides of a workpiece (1b-19d) engages stop elements (11, 12).

10. Grinding device according to one of claims 1 to 9, characterized in that the guide device (8, 8a, 8d) is adjustable, in particular for adjusting the angle of bevels to be ground and for adjusting the position of the grinding point on the grinding head (7).

1 1. Grinding device according to claim 10, characterized in that the guide device (8d) for bevel angle adjustment about an axis (25) is pivotable.

12. Grinding device according to claim 10 of 1 1, characterized in that a drive device for adjusting, in particular for oscillating adjustment, the grinding point position is provided.

13. Grinding device according to claim 12, characterized in that the drive device is in drive connection with the drive of the grinding head, preferably via a planetary or worm gear.

4. Grinding device according to claim 12, characterized in that the drive device comprises a separate drive motor or pneumatic cylinder.