CN112368111A

CN112368111A - Grinding block for manual application and system comprising grinding block and grinding tool

Info

Publication number: CN112368111A
Application number: CN201980043537.7A
Authority: CN
Inventors: S·比格尔
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2018-06-28
Filing date: 2019-06-18
Publication date: 2021-02-12
Also published as: WO2020002049A1; DE102018210567A1; EP3814054A1; EP3814054B1; US20210291320A1

Abstract

The application relates to a grinding block (10) for manual use, in particular for manually grinding surfaces, comprising at least one base plate (12) for holding a grinding tool (14) and at least one grinding block body (18) which has a gripping region (20). According to the invention, a battery-operated device (22) for sucking grinding dust is integrated into the grinding block (10), comprising at least one dust box (28), a motor housing (30) in which a drive motor (34) having a fan wheel (32) is arranged, and a battery (26) for supplying the drive motor (34) with current independently of the electrical network.

Description

Grinding block for manual application and system comprising grinding block and grinding tool

Technical Field

The present application relates to a grinding block for manual applications, in particular for manually grinding surfaces.

Background

Surface treatments for grinding as a product or object are known in various industrial fields such as woodworking and automotive. Grinding can be used for different purposes, such as polishing, smoothing, surface shaping, repair or for special applications, such as removal of colour layers or smoothing of body putty.

The tools for grinding are essentially characterized by the presence or absence of a surface configured for grinding action, provided with abrasive material, which is brought into contact with the surface to be treated, thereby grinding the surface to be treated. This can be done manually or mechanically. Furthermore, tools for hand grinding generally have a surface for gripping the tool.

A grinding block provided for manual application, in particular for manually grinding surfaces, having at least one base plate for holding a grinding tool and at least one grinding block body with a gripping region is known, for example, from EP 11182793 a 1. It is also known to construct the grinding block such that it is compatible with the commonly sold 150 mm grinding plates actually used in eccentric grinders and thus can also be used for hand grinding.

Disclosure of Invention

The present application is based on a grinding block for manual application, in particular for manual grinding of surfaces, having: at least one base plate for holding an abrasive article; and at least one grinding block body having a gripping area. According to the invention, a battery-operated device for sucking grinding dust is integrated into the grinding block, said battery-operated device comprising at least one dust box, a motor housing in which a drive motor with a fan wheel is arranged, and a battery for supplying the drive motor with current independently of the electrical network.

The grinding block is used for manual applications, in particular for manual grinding of surfaces. Grinding blocks are also referred to as sanding blocks and are distinguished from orbital and eccentric grinding tools in which automatic or motor grinding is carried out by using a motor, which drives a base plate motor that is mounted so as to be movable relative to the orbital and eccentric grinding tools. In the context of this document, a grinding block is therefore understood to mean a grinding block which does not have a motor for the motor-driven grinding operation. In this sense, the grinding blocks are used for manual application and manual grinding. The grinding block has a grinding block body, which in an embodiment of the grinding block can be realized as a housing of the grinding block. The grinding block body also has a gripping area. The gripping region is used for the user to grip the grinding block in order to enable a controlled guidance of the grinding block during the execution of the manual grinding movement, in particular on the workpiece. The gripping area may be configured as a handle in one embodiment of the sanding block. Alternatively or additionally, the gripping region may be at least partially gel-coated to enhance its gripability.

The base plate of the grinding block serves in particular to hold and fasten the grinding tool on the grinding block during the execution of the grinding process. The base plate is preferably embodied integrally therewith as part of the grinding block body. The base plate is designed to receive a grinding tool or may itself have at least one grinding surface, similar to a metal plane. In an embodiment of the grinding block, the base plate constitutes a substantially flat face. In an embodiment of the grinding block, the base plate has a layer of material suitable for forming a velcro connection, such as a layer of loop tape or a layer of flexible hook tape.

An accumulator operating device for sucking grinding dust is provided in the grinding block in an integrated manner, i.e. arranged in or on the grinding block body and/or at least partially integrated in the grinding block body. The battery-operated device for suction is used to suck grinding dust which forms during the grinding process in the manual application of the grinding block. The battery operating device for suction comprises at least one dust box, a motor housing in which a drive motor with a fan wheel is arranged, and a battery for supplying the drive motor with current independently of the electrical network. In this way, grinding dust falling down during the grinding process can be particularly effectively sucked off from the surface to be machined and collected in the dust box with the use of the battery-operated device for suction.

The drive motor is supplied with energy from the battery at least in the start-up state for a supply current that is independent of the electrical network. A battery is understood within the scope of the present application to be a battery pack which provides electrical energy and comprises at least one electrochemical battery cell. The rechargeable battery is in particular a rechargeable secondary battery which can be recharged when connected to a charging station. Suitable for supplying energy are, for example, batteries with chemical monomers which provide high power and/or high energy density, such as lithium chemical monomers and lithium ion chemical monomers, in particular lithium iron phosphate batteries, lithium-manganese oxide batteries, lithium-nickel-cobalt-manganese oxide batteries, superlithiated lithium-nickel-cobalt-manganese oxide batteries, lithium sulfur batteries, lithium-polymer batteries and lithium oxygen batteries.

In this way, a self-supplied, network-independent, i.e., in particular wirelessly implemented, grinding block can be provided, which has means for sucking away grinding dust. The grinding block thus forms a particularly lightweight, always available tool which can also be used or applied in cleaner environments, since the risk of flying dust and in particular the risk of environmental pollution is minimized on the basis of the battery-operated device for suction. Furthermore, an external device for the grinding block for suction can be dispensed with on the basis of an integrated battery operating device for suction. This makes it possible, in particular, to dispense with an external vacuum cleaner and/or a hose connection from the external vacuum cleaner to the grinding block, which hose connection strongly impedes the use of the grinding block during the manual grinding movement. Furthermore, the integration of the accumulator-operated device for suction can advantageously increase and balance the weight of the grinding block, so that the grinding block is well in the hand of the user during the grinding process, i.e., during the manual grinding movement.

In one embodiment of the grinding block, the dust box can be releasably fastened to the motor housing and can be removed from the grinding block from the outside. In this way, it is achieved that the dust box can be emptied in a simple manner if it is filled with grinding dust. For this purpose, the dust box can be removed from the grinding block, emptied and then inserted into the grinding block again, wherein a releasable fastening on the motor housing is again produced. In an alternative embodiment, the dust box can also be realized in the form of a flexible dust bag or the like, which can be releasably fixed on the motor housing. The dust bag can be received in the grinding block body or fastened to the outside of the grinding block body.

Accordingly, in an alternative or additional embodiment of the grinding pad, the accumulator can also be releasably fastened to the grinding pad body and can be removed from the grinding pad from the outside. In this way, when the battery is discharged, a fully charged further battery can be replaced in a simple manner. In one embodiment of the sanding block, the accumulator and/or the dust box can be received at least in sections in the gripping region of the sanding block, in particular in the handle of the sanding block. In this way, a particularly user-accessible arrangement of the removable parts of the grinding block can be provided, so that the accumulator can be easily replaced and the dust box can be easily emptied.

In one embodiment of the grinding block, an operating element for starting and stopping the drive motor is arranged on the outer surface of the grinding block. The operating element is used to start and stop the gettering. Such an operating element may be, for example, a push switch, a push button, a slide switch, etc. The operating element is arranged in particular on the side of the grinding block which faces the user when the grinding block is in use. Preferably, the operating element is arranged in or on the gripping area, in particular in or on the handle, so that it is always accessible to the user during the execution of the manual grinding movement.

In one embodiment of the grinding block, an air passage opening is formed in the motor housing, to which a dust box can be fastened in a releasable manner, wherein the dust box has at least one further air passage opening, on which a filter medium can be arranged. In this way, a particularly simple design, but a particularly efficient operation of the battery operating device for suction can be provided. The fan wheel, which is set in motion by the drive motor, generates an air flow which is directed from the surface of the workpiece to be machined into the motor housing. The air flow enters the dust box through the motor housing and the air through-openings, wherein dust carried by the air flow is trapped in the filter medium when it leaves the dust box through the further air through-openings.

In one embodiment of the grinding block, the base plate has at least one opening for sucking grinding dust, through which the dust can be sucked. The grinding block, in one embodiment a base plate, in particular has an air guide element for sucking away grinding dust, which is in particular connected to the at least one opening and to a battery operating device for sucking away grinding dust. This makes it possible to suck grinding dust formed during grinding away directly from the surface of the workpiece to be machined at the point of formation. The pollution of the surrounding environment caused by not directly performing dust suction on the workpiece is avoided.

In an alternative or additional embodiment of the grinding block, the grinding block has a dust suction nozzle for sucking away grinding dust, which is arranged on the outer side of the grinding block. The dust suction nozzle is also connected to a battery-operated device for sucking grinding dust, using the air guide element. This makes it possible to achieve a reliable dust suction on the workpiece in a simple manner, depending on the design. The dust suction nozzle can be arranged here, for example, around the grinding block. Alternatively, the dust suction nozzle can also be arranged on a defined side of the grinding block, for example on the lower side of the grinding block, the manual grinding movement preferably taking place in the direction of said side during the grinding process.

The present application also relates to a system comprising at least one grinding block as described above and at least one grinding tool configured to be connectable to a base plate of the grinding block, wherein the base plate and the grinding tool each have at least one opening, preferably a plurality of openings, for sucking off grinding dust.

"abrasive articles" are, for example, coated abrasive articles, in particular grinding paper, grinding foam, grinding fabric, grinding woven fabric, grinding felt, etc. In principle, bonded grinding tools, for example, split and rough grinding disks bonded with synthetic resin, are also conceivable. The grinding tool can be in particular in the form of various finished products, such as grinding disks or grinding belts. In one embodiment of the system, the one opening of the base plate and the one opening of the grinder, in particular the plurality of openings of the base plate and the plurality of openings of the grinder, are substantially congruent (completely overlap) in the state in which the grinder is connected to the base plate of the grinding block.

Drawings

In the following description, the invention is explained in detail on the basis of embodiments shown in the drawings. The figures, description and claims contain a number of combinations of features. Those skilled in the art can also appropriately view and generalize these features alone into other meaningful combinations. Like reference symbols in the various drawings indicate like elements.

The figures show:

FIG. 1 is a perspective view of an exemplary embodiment of a grinding block according to the present invention;

FIG. 2 is a schematic cross-sectional view of an embodiment of a grinding block of FIG. 1 according to the present invention;

figure 3 is a schematic cross-sectional view of an alternative embodiment of a grinding block according to the present invention.

Detailed Description

Fig. 1 shows a grinding block 10 according to the invention in a perspective view. A grinding block 10 for manual application, in particular for manual grinding of surfaces (not shown in detail here), has a base plate 12 for holding a grinding tool 14. The grinding tool 14 is arranged on the base plate 12 by means of a hook-and-loop closure, wherein the base plate 12 and the grinding tool 14 each have a complementary material layer 16 suitable for the formation of a hook-and-loop connection, in particular a loop layer and a flexible hook layer.

The material layer 16 suitable for forming the nylon snap connection is here at least on the underside of the base plate 12, in particular also on the side of the base plate 12. The base plate is in particular shaped here such that it forms at least one right-angled corner, in particular two or four right-angled corners. In the case of right-angled corners, the workpiece can be ground or polished well up to the corner. In order to make the grinding block 10 also compatible with the round grinding tools that are usually offered for sale: a layer of material 16 is also disposed on the side of the base plate 12. In this way, the circular section of the circular grinder 14 projecting beyond the lower side (grinding side) of the base plate 12 is turned up in the lateral direction and fastened to the material layer, wherein at the same time the right-angled corners of the lower side of the base plate 12 are covered by the grinder 14. The dimensions of the base plate 12 are selected here, for example, such that a 150 mm grinding tool 14 can be fastened to the base plate 12 without corrugations, wherein the protruding circle sections can likewise be folded over onto the sides of the base plate 12 without corrugations.

The grinding block 10 has a grinding block body 18, the grinding block body 18 having a grip region 20, wherein the grip region 20 is shaped like a ball (spherical) and is thus particularly well adapted to the hand that wraps the grip region. The surface of the grip region 20 can be glued (not shown in detail here).

The grinding block body 18, as a housing, at least substantially encloses the components of the grinding block 10 that are necessary and/or useful for implementing a battery operating device 22 integrated in the grinding block 10 for sucking grinding dust, see fig. 2. Between the grip region 20 and the base plate 12, a battery receptacle 24 is provided, which projects in particular axially into the grinding block body 18. The battery receptacle 24 serves for the reversible reception of the battery 26, see fig. 2.

Fig. 2 shows a schematic sectional illustration of the embodiment of the grinding block 10 according to the invention from fig. 1 together with the grinding block body 18, the grinding block body 18 having a grip region 20, a base plate 12 and a battery receptacle 24, in the embodiment shown a battery 26 being inserted into the battery receptacle 24. The battery 26 is used to supply energy to the battery operating device 22 for sucking grinding dust. For charging the battery 26 or for changing to another battery 26, the battery 26 can be reversibly removed from the grinding block 10 from the outside, since it is releasably fastened to the grinding block body 18. The accumulator 26 engages, for example, only in sections in the sanding block body 18 and can thus be received at least in sections in the grip region 20 of the sanding block 10. The accumulator 34 is designed in particular in the manner of a replaceable accumulator and can be releasably fastened, for example latched, to the grinding block body 18. The battery 26 illustratively has a nominal voltage of 10.8V, while the available capacity is 1.3Ah, 1.5Ah, 2.0Ah, or 4 Ah. In order to monitor the respective state of charge of the accumulator 34, the grinding block 10 can optionally have a state of charge indicator (not shown in detail here).

A dust box 28 and a motor housing 30 are also provided inside the grinding block 10, in particular the grinding block body 18. The dirt box 28 can be releasably secured to the motor housing 30. At least one fan wheel 32 and a drive motor 34 are arranged in the motor housing 30, wherein the fan wheel 32 is connected in a rotationally movable manner to the drive motor 34, in particular about a central rotational axis (rotational axis). The fan wheel 32 has ribs ("blades", not shown in detail here) which are inclined in the direction of the axis of rotation and accelerate the air from a region near the axis of rotation into a radially further region when the fan wheel 32 rotates (see arrows in fig. 2). The drive motor 34 is supplied with a current independent of the electrical system by the battery 26 during its operation.

On the user-facing side of the grip region 20, i.e. on the outer surface of the grinding block 10, an operating element 36 is arranged for switching the drive motor 34 on and off. The operating element 36 is realized in this embodiment as a capacitive switch which detects the presence of a hand on the grip region and enables/initiates the energy supply of the drive motor 34 after detecting that the hand remains for a defined period of time. For this purpose, the battery 34 is electrically conductively connected via contact elements to an electronics unit (not shown in detail here), which is arranged in the motor housing 30 and is connected to an operating element 36 for starting and stopping the drive motor 34. The electronic unit is at least designed to switch the drive motor 34 on and off and to control the drive motor 34 when the operating element 36 is actuated accordingly.

In the illustration, the motor housing 30 and the dust box 28 form a vacuum cleaner housing which has an air through-opening 38 formed both in the motor housing 30 and in the dust box 28. In the exemplary embodiment shown, the dust box 28 can be releasably connected to the motor housing 30 at this point (interface) or can be connected to it, in particular fastened to it. In the region of the air passage opening 38, preferably between the dust box 28 and the motor housing 30, a viscoelastic seal, in particular an annular rubber gasket (not shown in detail here), is arranged at least for sealing the motor housing 30 and the dust box 28. Which is preferably designed to fix, in particular to latch, the one-way filter medium 40 and/or the filter holder carrying the one-way filter medium 40 in a gas-tight manner to the motor housing 30. The unidirectional filter media 40 is used to enable airflow from the motor housing 30 into the dirt box 28 ("air permeable"), but to inhibit airflow in the opposite direction, i.e., back-flow. In this way, it is ensured that dust 42 already in the dust box 28 cannot be returned into the motor housing 30.

The dust box 28 is configured such that one side of the dust box 28 is implemented as part of the surface 44 of the sanding block body 18. In this way, the dust box 28 is at least sectionally receivable in the gripping area 20 of the grinding block 10. Furthermore, the dust box 28 can thus be both releasably fastened to the motor housing 30 and removed from the grinding block 10. For this purpose, a spring-loaded actuating element 46 is preferably arranged in the region between the actuating element 36 and the dust box 28, preferably also on the user-facing side of the sanding block 10, the actuating element 46 being operable for releasing the dust box 28 fastened to the motor housing 30. If the dust box 28 is filled with dust 42, the dust box 28 can be removed from the sanding block body 18, emptied and then inserted again in a particularly simple manner. An opening is formed in the side of the dust box 28 that is realized as the surface 44 of the grinding block body 18, which opening also serves as an air passage opening 38 and is preferably at least partially covered by a particularly fine filter medium 48. For this purpose, a filter holder (not shown in detail here) carrying the filter medium 48 can be fixed, in particular latched, in a gas-tight manner in the interior of the dust box 28. In this way, an air passage opening 38 is formed in the motor housing 30, and the dust box 28 is releasably fastened to the air passage opening 38, wherein the dust box 28 has at least one further air passage opening 38, on which a particularly fine filter medium 48 can be or can be arranged.

The deflecting device 50 is arranged in the motor housing 30 facing the air through opening 38, wherein the deflecting device 50 is preferably oriented obliquely to the axis of rotation of the fan wheel 32. An air guide element 52 is formed on the motor housing 30 in the region of the axis of rotation of the fan wheel 32, which is provided to guide the air flow from the base plate 12 in the direction of the region of the fan wheel 32 close to the axis of rotation (arrow in fig. 2). In particular, the air flow in this direction (suction effect of the fan wheel 32) is initiated on the basis of the rotational movement of the fan wheel 32.

The base plate 12 of the grinding block 10 has an opening 54, which is visible in the sectional view of the exemplary embodiment shown in fig. 2, i.e., is shown, for sucking away grinding dust. The opening 54 in the base plate 12 is connected to the motor housing 30 via a channel system 56 in the interior of the base plate 12, which channel system likewise forms the air guide element 52, and via the air guide element 52. An air guide element 52 for sucking away grinding dust is provided in particular in connection with the opening 54 and with the battery operating device 22 for sucking away grinding dust.

Fig. 2 also shows a system comprising at least one grinding block 10 and at least one grinding tool 14, which is connected to the base plate 12 of the grinding block 10, wherein the base plate 12 and the grinding tool 14 have at least one opening 54 each, preferably a plurality of openings 54 each, for sucking grinding dust off. The plurality of openings 54 in the base plate 12 and the plurality of openings 54 of the grinder 14 are substantially congruent (superposed so that air is permeable) in the state in which the grinder 14 is connected to the base plate 12 of the grinding block 10.

In an alternative embodiment of the grinding block 10, as shown in fig. 3, a dust suction nozzle 58 for sucking off grinding dust is arranged on the outside of the grinding block 10, in particular on the outside of the base plate 12. In this embodiment, the openings 54 in the abrasive article 14 and base plate 12 are not required to achieve the gettering effect.

During operation of the drive motor 34, an air flow (arrow) is generated which flows along the air guide element 52 into the motor housing 30 via the opening 54 or the dust suction nozzle 58 on the basis of the generated negative pressure and carries the dust 42 present on the workpiece surface into the dust box 28. The airflow enters the dirt box 28 through the diverter device 50. There, the air flow exits the sanding block 10 via the filter medium 48 as a clean air flow, while the dust 42 remains in the dust box 28.

Claims

1. A grinding block (10) for manual applications, in particular for manually grinding surfaces, having:

-at least one base plate (12) for holding a grinder (14); and the number of the first and second groups,

-at least one grinding block body (18) having a gripping area (20),

it is characterized in that the preparation method is characterized in that,

an accumulator operating device (22) for sucking grinding dust (42) is integrated in the grinding block (10), said accumulator operating device comprising at least one dust box (28), a motor housing (30) in which a drive motor (34) having a fan wheel (32) is arranged, and an accumulator (26) for supplying the drive motor (34) with current independently of the electrical network.

2. The grinding block (10) according to claim 1, characterized in that the dust box (28) can be releasably fixed on the motor housing (30) and can be taken out of the grinding block (10) from the outside.

3. The grinding block (10) according to any of the preceding claims, characterized in that the accumulator (26) can be releasably fixed on the grinding block body (18) and can be taken out of the grinding block (10) from the outside.

4. The grinding block (10) according to one of the preceding claims, characterized in that an accumulator (26) and/or a dust box (28) can be received at least in sections in the grip region (20) of the grinding block (10), in particular in the handle of the grinding block (10).

5. The grinding block (10) according to any of the preceding claims, characterized in that an operating element (36) for starting and stopping the drive motor (34) is arranged on the outer surface of the grinding block (10).

6. The grinding block (10) according to one of the preceding claims, characterized in that an air through opening (38) is formed on the motor housing (30), to which air through opening a dust box (28) is fastened in a releasable manner, wherein the dust box (28) has at least one further air through opening (38), on which a filter medium (48) can be arranged.

7. The grinding block (10) according to any of the preceding claims, characterized in that the bottom plate (12) has at least one opening (54) for sucking off grinding dust.

8. The grinding block (10) according to claim 7, characterized in that the grinding block (10), in particular the base plate (12), has an air guide element (52) for sucking away grinding dust, which is connected in particular to the at least one opening (54) and to the battery operating device (22) for sucking away grinding dust.

9. The grinding block (10) according to one of the preceding claims, characterized in that a dust suction nozzle (58) for sucking off grinding dust is provided, which is arranged on the outer side of the grinding block (10), wherein the dust suction nozzle (58) is connected by means of an air guide element (52) to a battery-operated device (22) for sucking off grinding dust.

10. A system comprising at least one grinding block (10) according to one of claims 1 to 9 and at least one grinding tool (14) which is configured to be connectable to a base plate (12) of the grinding block (10), wherein the base plate (12) and the grinding tool (14) each have at least one opening (54), in particular a plurality of openings (54), for suctioning grinding dust.

11. The system according to claim 10, characterized in that the one opening (54) of the base plate (12) and the one opening (54) of the grinding tool (14), in particular the plurality of openings (54) of the base plate (12) and the plurality of openings (54) of the grinding tool (14), are substantially congruent in the state in which the grinding tool (14) is connected to the base plate (12) of the grinding block (10).