Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
  • B23Q11/00—Accessories fitted to machine tools for keeping tools or parts of the machine in good working condition or for cooling work; Safety devices specially combined with or arranged in, or specially adapted for use in connection with, machine tools
  • B23Q11/0078—Safety devices protecting the operator, e.g. against accident or noise
  • B23Q11/0092—Safety devices protecting the operator, e.g. against accident or noise actuating braking or stopping means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25F—COMBINATION OR MULTI-PURPOSE TOOLS NOT OTHERWISE PROVIDED FOR; DETAILS OR COMPONENTS OF PORTABLE POWER-DRIVEN TOOLS NOT PARTICULARLY RELATED TO THE OPERATIONS PERFORMED AND NOT OTHERWISE PROVIDED FOR
  • B25F5/00—Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D63/00—Brakes not otherwise provided for; Brakes combining more than one of the types of groups F16D49/00 - F16D61/00
  • F16D63/006—Positive locking brakes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D67/00—Combinations of couplings and brakes; Combinations of clutches and brakes
  • F16D67/02—Clutch-brake combinations
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
  • B27B—SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR
  • B27B5/00—Sawing machines working with circular or cylindrical saw blades; Components or equipment therefor
  • B27B5/29—Details; Component parts; Accessories
  • B27B5/38—Devices for braking the circular saw blade or the saw spindle; Devices for damping vibrations of the circular saw blade, e.g. silencing
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
  • F16D11/00—Clutches in which the members have interengaging parts
  • F16D11/08—Clutches in which the members have interengaging parts actuated by moving a non-rotating part axially
  • F16D11/10—Clutches in which the members have interengaging parts actuated by moving a non-rotating part axially with clutching members movable only axially

Definitions

• the invention relates to a safety brake device for a machine tool.
• Safety braking devices are known from the prior art, for example from DE 10 2008 054 694 A1.
• the invention relates to a safety brake device for a machine tool for braking a driven by a drive unit, in particular by means of a motor, via an output unit, in particular an output shaft, machining tool.
• the safety brake device comprises at least one decoupling device which is provided to decouple the output unit during a braking operation from the drive unit in order to reduce a rotational mass to be braked and / or rotational energy of the output unit.
• the safety brake device also comprises at least one brake device, having at least a first brake device part and a second brake device part, the first brake device part being arranged on the output unit essentially in a rotationally fixed manner, in particular on the Output shaft of the output unit is arranged essentially rotation test, and wherein the second brake device part is provided to be arranged essentially rotation test related to the machine tool.
• the first braking device part and the second braking device part are provided for mechanically interacting with one another during a braking operation and for braking, in particular stopping or blocking, rotation of the output unit.
• the first brake device part of the Bremsvor direction is made in one piece, in particular in one piece, with the decoupling device.
• a “safety brake device” is to be understood to mean, in particular, a device which brakes or stops a processing tool in a situation in which the processing tool poses a danger to an operator by means of at least the braking device.
• the safety brake device brakes the processing tool when the processing tool is approached or touched by a user.
• the safety brake device further comprises a computing unit and a sensor unit, the computing unit communicating with at least one sensor of the sensor unit, the sensor being intended to present a danger to an operator, in particular an approaching of the operator to the machining tool and / or a touch of the processing tool by the operator.
• Electronics of the safety brake device can then, after detection of an approach by the operator to the machining tool and / or after detection of a contact of the operator with the machining tool, trigger an actuator element, for example, which triggers a braking process using the brake device.
• the actuator element can in particular be implemented as a component of the braking device or else separately.
• a “machine tool” is to be understood to mean in principle any machine tool that uses a drive unit via an output unit, in particular has an output shaft, driven, rotatably mounted machining tool.
• the machining tool can in particular also be implemented as a tool holder.
• the machining tool is essentially non-rotatably connected to the output unit or, at least in an operating state of the machine tool, can be essentially non-rotatably connected to the output unit, for example via a tool holder, so that a torque can be transmitted from the output unit, in particular the output shaft, to the machining tool .
• essentially non-rotatable is to be understood to mean that the machining tool performs a relative rotation of less than 15 °, in particular less than 10 °, in particular less than 5 °, in relation to the output unit in one braking operation.
• the torque is generated by a drive unit, for example an electric motor, in particular a brushless direct current motor (EC motor), and / or another motor which appears useful to the person skilled in the art.
• An output shaft enables the processing tool to rotate by rotating the output shaft about its longitudinal axis. Examples of such machine tools include, in particular, drilling machines, brushcutters, lawn mowers, circular saws, circular table saws, cross-cut saws, miter saws or other machine tools that appear useful to the person skilled in the art.
• the machine tool can be implemented as a hand-held hand machine tool, for example as a cordless cordless circular saw or the like.
• the machine tool can be realized as a hand-held circular saw with a processing tool, which is driven by a motor via an output shaft and is designed as a circular saw blade, and with a sensor plate which detects contact of human skin with the processing tool.
• the output unit in particular the output shaft, is connected to the drive unit, in particular the drive shaft, using a gear or a clutch.
• the decoupling device is provided to decouple the drive unit in a braking process from the drive unit in order to reduce a rotational mass and / or rotational energy to be braked from the drive unit.
• a “decoupling device” in particular a device to be understood, which is intended to interrupt torque transmission between the output unit, in particular the output shaft, and the drive unit, in particular an input shaft or motor shaft, to un interrupt.
• the decoupling device is designed as a claw clutch, as a slip clutch, as a gear clutch (spur gear clutch or crown gear clutch) and / or as another decoupling device that appears sensible to a person skilled in the art.
• the first brake device part is designed as a spur gear or a crown gear.
• the phrase “to decouple in terms of drive” should in particular be understood to mean the interruption of a power flow and / or a power flow between the output unit, in particular the output shaft and the tool holder, and the drive unit.
• the standstill characterizes the first time the zero point of the rotational speed of the drive shaft is reached, regardless of whether a (slight) rotation of the drive shaft then occurs - for example due to material relaxation effects.
• the braking device can also be constructed more compactly and more effectively.
• the decoupling device in the coupled state can act as a transmission which adjusts a rotational speed of the drive shaft, in particular the motor, to a rotational speed of the output unit, in particular the output shaft and the machining tool (for example from 20,000 to 40,000 revolutions per minute to 5,000 Revolutions per minute).
• a “braking device” is to be understood as a device which is used to brake or stop the rotation of the machining tool in the event that an operator detects an approach or touch of the machining tool.
• the braking device is implemented as an at least two-part braking device, having at least a first braking device part and a second braking device part.
• the first brake device part and the second brake device part as complementary components of an at least two-part claw clutch (or equivalent to this: claw brake), the first brake device part and the second brake device part each having at least one toothing element, which are intended to be in engagement with one another during a braking operation and such a rotation to brake the output unit, in particular to stop it.
• a “two-part claw clutch” is to be understood as a clutch that works by means of a positive coupling, in that toothing elements on the two brake device parts are brought into engagement with one another and thus a torque transmission as a result of a relative movement of the two brake device parts to one another, in particular as a result of one Relative movement of the two Bremsvorrich device parts in the direction of rotation to each other, allow.
• a positive connection can be used to carry out a braking process in a particularly fast and safe manner.
• the first brake device part is arranged on the output unit, in particular on the output shaft, essentially in a rotationally fixed manner.
• the first brake device part can be arranged axially movable or in a further embodiment also axially immovable on the output unit.
• the second part of the braking device is provided for the purpose of being substantially non-rotatably connected to another component of the machine tool, in particular for example a housing, a gear housing, a motor housing or another structure of the machine tool, and thus being at least substantially non-rotatably based on the Machine tool to be arranged.
• the second brake device part can be provided to be connected essentially immovably to the other component of the machine tool and thus not only to be arranged in a substantially rotationally fixed manner with respect to the machine tool.
• the second brake device part is designed to be essentially immovable relative to a motor housing of the machine tool.
• free rotation of the second brake device part with respect to the machine tool and also with respect to the drive unit, in particular with respect to the output shaft, and thus with respect to the first non-rotatably connected to the drive unit first Bremsvor direction part can be prevented.
• “Essentially rotation test” is to be understood to mean that a respective brake device part is not substantially displaceable (rotatable) or slidably in the direction of the circumference of the output unit, in particular the output shaft.
• the first brake device part is arranged essentially in a rotationally fixed manner on the output unit” is to be understood to mean that the first brake device part is connected with a rotary movement of the output unit, in particular the output shaft, to the output unit, in particular the output shaft, whereby by “Essentially” a maximum relative movement of the output unit, in particular the output shaft, and the first part of the brake device with respect to one another, which is less than 15 °, in particular less than 10 °, very particularly less than 5 °. In one embodiment, the maximum permissible relative movement of the first brake device part is 12.5 °. In particular, this relative movement only occurs with a very large torque applied to the first brake device part, as can occur during an abrupt braking operation.
• the second brake device part is arranged essentially in a rotationally fixed manner, in particular with respect to the machine tool essentially arranged in a rotationally fixed manner, that a maximum relative movement of the component of the machine tool to which the second brake device part is attached and the second brake device part should be allowed to each other, which is less than 30 °, in particular less than 10 °, very particularly less than 5 °. In one exemplary embodiment, the maximum permissible relative movement of the second brake device part is 15 °.
• “Axially movable / immovable” is to be understood to mean that the first part of the brake device is displaceably or non-displaceably mounted in the axial direction of the output unit, in particular the output shaft.
• “Gear elements” are to be understood as design-related projections of both the first brake device part and the second brake device part, which are intended to be brought into engagement with one another. Since form the gear elements of a brake device part at the same time Gear elements of the other brake device part receiving recesses, so that when the brake device parts interact, projections (gear elements) and recesses (recesses between adjacent gear elements) form mutually complementary pairs.
• the toothing elements are brought into engagement with one another in such a way that by torque transmission between the (at the drive unit) essentially rotatably arranged (co-rotating) first brake device part and the second brake device part arranged at least essentially non-rotatably on the machine tool relative to the output unit Torque transmission can be generated, which counteracts the rotational movement of the first brake device part and thus brakes, in particular stops or blocks, the rotation of the drive unit, in particular the output shaft.
• the toothing elements are provided equidistantly and in particular on the respective brake device part in such a way that they are arranged in a rotationally symmetrical manner with respect to the axis of rotation of the output unit, in particular the output shaft.
• One-piece is to be understood in particular to mean that there is an integral component, which in principle can also be composed of different components that are held together, for example, in a force-fitting and / or positive manner.
• “One-piece” is to be understood in particular to mean that there is an integral, in particular materially integral, component.
• the component does not appear to be composed of a plurality of components which are joined together and which can be detached from one another. Appropriate disassembly cannot take place without destroying the component.
• the first brake device part can be used both for coupling and decoupling the output unit from the drive unit and for performing the braking process.
• the invention thus allows only one assembly (instead of a plurality of assemblies) to be used for the decoupling / coupling function and the braking function.
• the space required for the safety brake device can also be kept low.
• the overall functionality can be significantly improved by directly linking the functions in an assembly braking time will be significantly reduced. Consequently, the invention allows the specification of a safety brake device which is improved with regard to functional integration, space requirements and production outlay.
• the decoupling processing device in particular the location of the drive decoupling, can be arranged particularly close to the machining tool in order to keep a flywheel mass that is to be stopped particularly low.
• the first part of the Bremsvor device is movable in the axial direction on the output unit, in particular on the output shaft, and in the coupled state couples the output unit to the drive shaft of the drive unit.
• the safety brake device comprises a biasing element which is provided to press at least the first brake device part into an initial position in which the output unit and the drive shaft of the drive unit are in a coupled state.
• the safety brake device has at least one actuator element, which is intended to move the first brake device part in the axial direction on the output unit when a user recognizes an approach or touch of the processing tool in such a way that the output unit can be decoupled from the drive shaft is, in particular is decoupled, and the first braking device part, in particular against a restoring force, can be moved toward the second braking device part, in particular is moved, so that the toothing elements of the first braking device part and the toothing elements of the second braking device part are brought into engagement with one another.
• the actuator element advantageously brings about a force in the axial direction of the output unit, in particular the output shaft, on the first brake device part.
• the safety brake device has at least one insulation element which is arranged on or in the first brake device part, the at least one insulation element being provided to electrically isolate the output unit from the drive unit. In this way it can be ensured that the output unit, in particular the output shaft including the machining tool, does not influence a capacitive measurement in particular by means of the sensor of the machine tool.
• the insulation element can be implemented as a plastic layer applied to the decoupling device, in particular to a spur gear.
• the design of the brake device of the safety brake device according to the invention allows a particularly high level of functional integration with particularly high braking effectiveness, i.e. can be achieved in a particularly short time between triggering the braking process and stopping the machining tool.
• the braking device reacts particularly quickly after triggering the actuator element in order to avoid or completely exclude injuries to the operator in the event of an intervention in the moving machining tool.
• the braking device of the safety brake device can be designed in a particularly simple and therefore particularly reliable manner.
• the invention relates to a machine tool, in particular a hand machine tool, in particular a hand-held circular saw with a machining tool designed as a circular saw, comprising an inventive tool Safety brake device.
• a particularly short braking time determined between triggering a braking process and stopping the processing tool, is achieved for braking a movement, in particular a rotation, of the processing tool.
• this maximum braking time (after the braking process has been triggered by the actuator) is less than 5 milliseconds, in particular less than 3 milliseconds, in particular less than 1.5 milliseconds. In one embodiment, the maximum braking time is 2.8 seconds. The safety of a user of the machine tool can thus be significantly increased.
• the machine tool furthermore has a sensor plate which detects an approach or touch of the machining tool by a user, in particular contact of human skin with the machining tool.
• Electronics of the machine tool initiate the detection of the actuator element after detection of an approach or touch of the processing tool by a user, which then triggers a braking operation.
• the actuator element actively moves the first brake device part in order to bring the two brake device parts into engagement with one another during a braking operation and to brake, in particular stop, a rotation of the output unit, in particular the output shaft.
• the actuator element causes the decoupling of the output unit from the drive unit by the movement of the first part of the brake device.
• Figure 1 a machine tool according to the invention in perspective
• FIG. 2 a sectional illustration through parts of the machine tool including the safety device and brake device according to the invention in a schematic illustration
• Figure 3 two schematic views of a decoupling device according to the invention including insulation element.
• FIG. 1 shows a machine tool 10 according to the invention, realized as a hand-held circular saw 10a.
• a machine tool 10 realized as a hand-held circular saw 10a.
• the explanations are not to be understood as limited to a hand-held circular saw 10a, but rather the technical teachings on which the explanations are based, in principle also to any other machine tools which appear sensible to a person skilled in the art, in particular, for example, drilling machines, lawn mowers, brushcutters or the like are portable about.
• the motor housing 12 encloses an interior in which at least one drive unit is arranged in the form of an electric motor drive.
• a motor 22 of the drive unit drives a machining tool 28 (cf. FIG. 1) in a work process via a drive shaft 24, in particular a motor shaft, and an output shaft 26.
• the machining tool 28 is out here as a saw blade, in particular as a circular saw blade.
• a saw blade cover 30 protects against touching the machining tool 28 and against the machining chips 28 ejected workpiece chips of a workpiece (see FIG. 1).
• a safety brake device 32 is provided for braking the machining tool 28 as soon as a contact or approach to a human body part, such as a hand, is detected with a sensor 34 of the circular saw 10a.
• sensor 34 is implemented by a capacitively measuring sensor. The sensor 34 enables a body part approaching the machining tool 28 to be detected on the basis of capacitive measurements (for example by means of an alternating field), a detection signal being generated as a result of a detection and being output to a control device of the portable circular saw 10a (cable connection in FIG. 2).
• the safety brake device 32 comprises an actuator element 36, which is provided to trigger a braking process as a result of detection of a touch or an approach of a human body part to the processing tool 28.
• an actuator element 36 which is provided to trigger a braking process as a result of detection of a touch or an approach of a human body part to the processing tool 28.
• a current flow through the actuator element 36 is initiated by electronics 102 of the safety brake device 32 (not shown in detail here), as a result of which the actuator element 36 triggers a braking process by the actuator element 36 being in the correct order Functionality (ie the rotation) from the drive shaft 26 acts and brakes or stops.
• FIG. 2 also shows a first gear 38 arranged on the drive shaft 24, which meshes with a second gear 40 arranged on the output shaft 26.
• the first gear 38 and second gear 40 form a safety clutch and a gear stage.
• the safety clutch protects the drive unit, in particular the motor 22, from damage which can be caused by the machining tool being blocked.
• the mass and energy to be braked during a braking process can be reduced by means of the safety clutch by the drive shaft 24 being decoupled from the drive shaft 26. In this way, a particularly short braking time can be made possible.
• the safety brake device 32 further comprises a decoupling device 52, which is provided for the output unit, in particular the output shaft 26, in a braking operation from the drive unit, in particular the drive shaft 24, to decouple the drive in order to reduce a rotational mass of the drive unit to be braked.
• the second gear 40 (spur gear) is arranged axially displaceably on the output shaft 26, while it is secured against rotation by profiling both the second gear 40 and the output shaft 26.
• a spring element 54 holds the second gear 40 in a coupled position during normal operation (ie without braking operation) by pressing it against a stop element 104 on the output shaft 26. In the coupled position, a torque can be safely transmitted from the drive shaft 24 via the first gear 38 and the second gear 40 to the output shaft 26.
• the second gear 40 in particular its spur toothing, thus forms the decoupling device 52.
• a force can be exerted on the second gear 40 in the axial direction 100 of the output shaft 26 during a braking operation and decoupling operation.
• the second gear 40 on the output shaft 26 can be moved axially away from the stop 104 until the toothing between the first gear 38 and the second gear 40 disengages. In this way, the output unit, in particular the output shaft 26, can be decoupled from the drive unit, in particular the drive shaft 24.
• the safety brake device 32 has at least one brake device 42, comprising at least a first brake device part 44 and a second brake device part 46.
• the first brake device part 44 is arranged on the drive unit essentially in a rotationally fixed manner, in particular on the drive shaft 26 of the drive unit, essentially arranged in a rotationally fixed manner .
• the second brake device part 46 is arranged essentially in a rotationally fixed manner, in particular essentially in a rotationally fixed manner with respect to the motor housing 12 of the machine tool 10.
• the first braking device part 44 and the second Bremsvorrich device part 46 are provided to interact mechanically with each other during a braking operation and to brake, in particular to stop, a rotation of the output unit, in particular the output shaft 26. As shown in FIG.
• the first braking device part 44 of the braking device 42 is made in one piece, in particular in one piece, with the decoupling device 52.
• Such components required to carry out a braking process are connected to the second gear 40 (in one piece) or are produced directly integrally with the second gear 40 (in one piece).
• the braking device 42 is designed as an at least two-part claw coupling with a first claw coupling part and a second claw coupling part, the first claw coupling part being realized by the first braking device part 44 and being arranged on the output shaft 26 essentially in a rotationally fixed and axially movable manner and the second Claw coupling part is realized by the second Bremsvorrich device part 46 and is arranged substantially rotatably relative to the motor housing 12 of the machine tool 10.
• the two Bremsvorrich device parts 44, 46 each have eight toothing elements 48, which are intended to be in engagement with each other during a braking process and to brake, in particular to stop, a rotation of the output shaft 26.
• the safety brake device 32 has at least one insulation element 106 which is arranged on the first brake device part 44, in particular the decoupling device 52, the at least one insulation element 106 being provided for the drive unit, in particular the output shaft 26, electrically isolate from the drive unit, in particular the drive shaft 24 in particular.
• the output unit, in particular the output shaft 26, can be electrically insulated from the rest of the machine tool 10, so that, in particular, capacitance-measuring sensors 34 are not restricted in their functionality.
• the Isolationsele element 106 is introduced into the second gear 40 and is preferably made of a plastic or ceramic element. The insulation element electrically separates an outer region 108 of the second gear 40 from an inner region

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Forests & Forestry (AREA)
• Braking Arrangements (AREA)
• Auxiliary Devices For Machine Tools (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=68069739

Family Applications (1)

Country Status (5)

Families Citing this family (3)

Family Cites Families (20)

• 2018
  • 2018-09-27 DE DE102018216573.4A patent/DE102018216573A1/de active Pending
• 2019
  • 2019-09-20 US US17/275,714 patent/US11673218B2/en active Active
  • 2019-09-20 CN CN201980063491.5A patent/CN112770871A/zh active Pending
  • 2019-09-20 EP EP19778449.9A patent/EP3856454A1/de not_active Withdrawn
  • 2019-09-20 WO PCT/EP2019/075279 patent/WO2020064524A1/de unknown

Also Published As

Similar Documents

Legal Events