FR3024063A1 - ELECTROPORTATIVE MACHINE WITH AN IMPROVED ABRASIVE DISC, AND ANTI-VIBRATION MOUNTING DEVICE FOR AN ABRASIVE DISC ON AN ELECTROPORTATIVE MACHINE - Google Patents

Abstract

A power tool (1) for performing surfacing such as grinding or sanding, of the type comprising a rotating mandrel (4), associated with an engine block (3), around which are mounted, an abrasive disc (2), and a clamping nut (5) for holding and locking in position said abrasive disk (2). According to the invention, the electric machine (1) comprises a member (13) of elastomeric material cooperating with the mandrel (4), and arranged radially between the abrasive disc (2) and said mandrel (4) so as to absorb vibrations tangential transmitted to the mandrel (4).

Description

TECHNICAL FIELD The present invention relates to the technical sector of abrasive disc machines and electrical appliances, intended for the execution of the invention. The present invention relates to the technical field of abrasive disc machines and appliances intended for the execution of the invention. BACKGROUND OF THE INVENTION work such as sanding, cleaning, surfacing, grinding, drilling on any type of walls or surfaces to be treated or renovated. The present invention more particularly relates to an improved power tool in that it generates, in use, less vibration than the power tools of the current state of the art. The present invention also relates to a device for providing anti-vibration mounting of an abrasive disc on a power tool. PRIOR ART It is known from the state of the art of electric power tools, for example at high frequencies, such as sanding machines or grinders to carry out work such as sanding, grinding, etc. These electric machines can advantageously, to be connected to vacuum units. Such a power-generating machine generally comprises a rotating mandrel, associated with an engine block, around which are mounted, an abrasive disk, and a clamping nut for holding and locking in position said abrasive disk 30. makes it possible to drive an abrasive disk in rotation in order to carry out operations of surfacing materials such as concrete, plaster, etc. However, such a power-generating machine has the disadvantage of being, during its use, subject to vibrations, which The vibrations cause discomfort to the user and also reduce the service life of the electric motor of the power tool. Another disadvantage of this type of power tool is that during surfacing work, abrasive disk slip effects occur. The differential speed between the abrasive disk and the mandrel causes degradation of said abrasive disk, mandrel, and some other engine components. SUMMARY OF THE INVENTION One of the aims of the invention is therefore to remedy at least one of the aforementioned drawbacks by proposing a portable abrasive disc machine whose vibrations during its use are reduced.

Another object of the invention is to provide such a machine which eliminates the slip effects of the abrasive disk. Finally, the invention aims to provide such a power tool that is simple, safe and rational design. To this end, it has been developed a power tool, intended for performing surfacing such as grinding or sanding, of the type comprising a rotating mandrel, associated with a motor block, around which are mounted, an abrasive disc, and a clamping nut for holding and locking in position said abrasive disc. According to the invention, the electric machine comprises a member of elastomeric material cooperating with the mandrel, and arranged radially between the abrasive disc and said mandrel so as to absorb tangential vibrations transmitted to the mandrel.

Advantageously, and to further reduce the vibrations during use of the electric machine, the latter comprises a member of elastomeric material cooperating with the mandrel, and arranged axially between the abrasive disc and the clamping nut so as to absorb axial vibrations transmitted to the mandrel.

According to a particular embodiment of the invention, the axial vibration absorption member is in the form of a washer having an internal diameter adjusted to the diameter of the mandrel.

In order to avoid the effects of slippage of the abrasive disk during use of the power tool, the latter comprises an intermediate coupling disk mounted between the abrasive disk and the mandrel for securing said abrasive disk. The intermediate coupling disk is arranged radially between the tangential vibration absorbing member and the abrasive disk. Advantageously, and to further reduce the vibrations during the use of the electrical machine, the vibration absorption member tangential comprises a washer adapted to perform an axial support on a portion of the abrasive disc, or on a portion of the intermediate coupling disc.

According to a particular embodiment, the tangential vibration absorption member comprises a cylindrical sleeve, adjusted to the diameter of the mandrel, and comprising an internal portion of non-circular section intended to cooperate with a complementary shape on the mandrel for s'. subject to rotation of said mandrel.

The invention also relates to a device for providing anti-vibration mounting of an abrasive disc on a power-generating machine of the type comprising a rotating mandrel, associated with an engine block, around which the abrasive disc must come to mate directly. or by means of an intermediate coupling disc, and around which a tightening nut is adapted to be screwed to hold and lock in position said abrasive disc. According to the invention, the anti-vibration mounting device comprises a member made of elastomeric material shaped to cooperate with the mandrel, and to be arranged radially between the mandrel and the abrasive disk or the intermediate coupling disk, to absorb tangential vibrations transmitted to the mandrel. Advantageously, and in order to make it possible to further reduce vibrations when using a power-operated machine, the device according to the invention comprises a washer made of elastomer material intended to be mounted around the mandrel, and to be arranged axially between the disc abrasive and clamping nut so as to absorb axial vibrations transmitted to the mandrel.

According to a particular embodiment, the tangential vibration absorption member is in the form of a cylindrical sleeve, having an internal diameter intended to be adjusted to the diameter of the mandrel, and comprising an intermediate washer intended to produce axial support on the abrasive disk or on the intermediate coupling disk. The tangential vibration absorption member is secured in any suitable manner to the rotation of the mandrel. According to a particular embodiment, the cylindrical sleeve of said tangential vibration absorption member has an inner portion of non-circular section intended to cooperate with a complementary shape on the mandrel to secure the rotation of said mandrel. BRIEF DESCRIPTION OF THE DRAWINGS Other characteristics and advantages of the invention will emerge clearly from the description which is given hereinafter, by way of indication and in no way limitative, with reference to the appended figures in which: FIG. 1 is a view diagrammatic perspective view of an anti-vibration electric machine according to the invention; - Figure 2 is a schematic perspective exploded view and seen from above, the anti-vibration mounting of the abrasive disk of the power tool according to the invention; FIG. 3 is a schematic representation similar to that of FIG. 2, said anti-vibration assembly being illustrated from below; FIG. 4 is a diagrammatic representation in partially truncated perceptive of the engine block portion of the anti-vibration machine according to the invention. DETAILED DESCRIPTION OF THE INVENTION With reference to FIG. 1, the invention relates to a power-operated machine (1) with an abrasive disc (2), such as, for example, a sander or an arm-type grinder. The electric machine (1) comprises, in a general manner, a motor unit (3) capable of driving in rotation an active head portion receiving an abrasive disc (2). The machine (1) is intended for the execution of works such as sanding, cleaning, surfacing, grinding, drilling on any type of walls or surfaces to be treated or renovated. This machine (1) is, advantageously, intended to be connected to a vacuum unit (not shown). With reference to FIGS. 2 to 4, the power-driven machine (1) generally comprises a rotating mandrel (4) associated with the motor unit (3), around which are mounted an abrasive disc (2), and a clamping nut (5) for holding and locking in position said abrasive disk (2). The abrasive disk (2) is well known in the state of the art. It comprises, in a general manner, a bottom wall (2a) having a central orifice (6) intended, on the one hand, to allow the passage of the mandrel (4) of the electric power machine (1), and, on the other hand, to cooperate with an intermediate coupling disc (7) for coupling as such to the mandrel (4). The bottom wall (2a) is extended by an intermediate wall (2b), of partially conical configuration, provided with a plurality of radial slots (8) for the flow of dust and residues from surfacing work. The radial slots (8) are evenly distributed over the surface of the abrasive disk (2) and relative to the center of said abrasive disk (2). The intermediate wall (2b) is extended by a peripheral ring (2c), parallel to the bottom wall (2a). This peripheral ring (2c) receives a plurality of abrasive members (9) protruding axially from the peripheral ring (2c), and in a direction opposite to the bottom wall (2a). The abrasive members (9) are regularly distributed over the circumference of the peripheral ring (2c). The intermediate disk (7) is used to couple the abrasive disk (2) to the mandrel (4), while performing a keying said abrasive disk (2) to avoid the effects of slippage of said abrasive disk (2) during use of the electric machine (1).

For this purpose, the intermediate coupling disc (7) comprises a cylindrical seat (7a) intended to fitly engage with the central opening (6) of the abrasive disc (2). The cylindrical bearing surface (7a) comprises two bosses (10), extending radially and in a diametrically opposite manner, able to engage in two complementary cutouts (11) extending the central orifice (6) of the abrasive disk. (2). This feature allows the keying of the abrasive disc (2) and avoid skid effects. The cylindrical surface (7a) is traversed by an axial bore (12) intended, firstly, to receive a tangential vibration absorption member (13), and secondly to allow the passage of the mandrel (4). ) of the power tool (1) for the coupling as such. The cylindrical bearing (7a) is extended by a peripheral ring (7b), able to bear against the bottom wall (2a) of the abrasive disc (2). This peripheral ring (7b) extends radially and comprises a plurality of axially extending teeth (14), in correspondence with the plurality of radial slots (8) that comprise the abrasive disc (2), so that said teeth (14) engage 3024063 6 inside said radial lumens (8). This feature ensures better keying and rotation of the abrasive disk (2). According to the invention, and in order to reduce the vibrations during the use of the electric machine (1), the latter comprises, as mentioned above, a member (13) made of elastomer material mounted around the mandrel (4), and arranged radially between the intermediate coupling disc (7) and said mandrel (4) so as to absorb tangential vibrations transmitted to the mandrel (4).

This member (13) of elastomeric material comprises a cylindrical sleeve (13a) having an outer diameter fitted to the diameter of the bore (12) of the cylindrical bearing surface (7a) of the intermediate coupling disc (7) to be engaged therein . The member (13) for absorbing tangential vibrations further comprises a washer 15 (13b) extending radially, and adapted to perform an axial bearing on the peripheral ring (7b) of the intermediate coupling disc (7). This washer (13b) is defined on an intermediate portion of the cylindrical sleeve (13a) so as to define an upper cylindrical sleeve on one side of the washer (13b), and a lower cylindrical sleeve on the other side of the washer ( 13b). This washer (13b) makes it possible to further reduce the vibrations and in particular to also absorb the axial vibrations transmitted to the mandrel (4) during the use of the power-operated machine (1). The peripheral ring (7b) of the intermediate coupling disk (7) has a circular housing (7c) for receiving the washer (13b) of the tangential vibration absorption member (13).

The cylindrical sleeve (13a), and in particular the upper cylindrical sleeve comprises an inner portion (15) of non-circular section, for example rectangular, intended to cooperate with a complementary shape (4a) on the mandrel (4) for securing the rotation of said mandrel (4).

The power tool (1) comprises another elastomer material member (16) mounted around the mandrel (4) and arranged axially between the abrasive disc (2) and the clamping nut (5) so as to absorb vibrations. axial forces transmitted to the mandrel (4). This axial vibration absorbing member (16) is in the form of a washer having an internal diameter adjusted to the diameter of the mandrel (4), and an outer diameter, preferably, fitted to the outer diameter of the mandrel (4). tightening nut (5). The clamping nut (5) is conventional, and well known in the state of the art. This clamping nut (5) is screwed to the free end of the mandrel (4). Thus, when using the power tool (1), the axial and tangential vibrations transmitted by the abrasive disk (2) to the mandrel (4) are absorbed by the elastomeric material members (13, 16). The use for the user is therefore more comfortable. The vibrations transmitted by the mandrel (4) to the electric motor are thus reduced, which makes it possible to preserve said electric motor and to increase its life span.

Claims (7)

REVENDICATIONS1. A power tool (1) for performing surfacing such as grinding or sanding, of the type comprising a rotating mandrel (4), associated with an engine block (3), around which are mounted, an abrasive disc (2), and a clamping nut (5) for holding and locking in position said abrasive disc (2), characterized in that it comprises a member (13) of elastomeric material cooperating with the mandrel (4), and arranged radially between the disc abrasive (2) and said mandrel (4) so as to absorb tangential vibrations transmitted to the mandrel (4). Power-operated machine (1) according to claim 1, characterized in that it comprises a member (16) of elastomeric material cooperating with the mandrel (4), and arranged axially between the abrasive disk (2) and the clamping nut ( 5) so as to absorb axial vibrations transmitted to the mandrel (4). Power-operated machine (1) according to claim 2, characterized in that the member (16) for absorbing axial vibrations is in the form of a washer having an internal diameter adjusted to the diameter of the mandrel (4). Power-operated machine (1) according to one of the preceding claims, characterized in that it comprises an intermediate coupling disk (7) mounted between the abrasive disk (2) and the mandrel (4) to provide a keying of said abrasive disk (2), said intermediate coupling disc (7) being arranged radially between the tangential vibration absorbing member (13) and the abrasive disc (2). Grinding machine (1) according to one of the preceding claims, characterized in that the member (13) for absorbing tangential vibrations comprises a washer (13b) adapted to perform an axial bearing on a portion (2a) of the abrasive disc (2), or on a part (7b) of the intermediate coupling disc (7). Power-operated machine (1) according to one of the preceding claims, characterized in that the member (13) for absorbing tangential vibrations comprises a cylindrical sleeve (13a), adjusted to the diameter of the mandrel (4), and comprising a portion internal member (15) of non-circular section intended to cooperate with a complementary shape (4a) on the mandrel (4) for securing the rotation of said mandrel (4). Device for ensuring an anti-vibration mounting of an abrasive disc (2) on a power-operated machine (1) of the type comprising a rotating mandrel (4), associated with an engine block (3), around which, the abrasive disc (2) must come 10 2. 15 3. 20 4. 25 5. 30 6. 35 7. 40 3024063 9 58. 9. 20 10. 25 coupling directly, or by means of an intermediate coupling disc (7), and around which a tightening nut (5) is intended to be screwed to maintain and lock in position said abrasive disc (2), characterized in that it comprises a member (13) made of elastomeric material shaped to cooperate with the mandrel (4), and to be arranged radially between the mandrel (4) and, the abrasive disc (2) or the intermediate coupling disc (7), so as to absorb tangential vibrations transmitted to the mandrel (4). Anti-vibration mounting device according to claim 8, characterized in that it comprises a washer (16) of elastomer material intended to be mounted around the mandrel (4), and to be arranged axially between the abrasive disc (2) and the clamping nut (5) so as to absorb axial vibrations transmitted to the mandrel (4). Anti-vibration mounting device according to one of claims 7 and 8, characterized in that the tangential vibration absorbing member (13) is in the form of a cylindrical sleeve (13a) having an internal diameter for to be adjusted to the diameter of the mandrel (4), and comprising an intermediate washer (13b) for performing axial support on the abrasive disc (2), or on the intermediate coupling disc (7). Anti-vibration mounting device according to claim 9, characterized in that the cylindrical sleeve (13a) has an inner portion (15) of non-circular section intended to cooperate with a complementary shape (4a) on the mandrel (4) for subject to rotation of said mandrel (4).