EP2834044B1 - Handheld machine-tool device - Google Patents

Description

State of the art

It is in DE 196 41 618 A1 or in US 2007/084613 A1 already a hand machine tool device with a drive motor, a tool spindle, a hand machine tool housing, a monitoring unit, which is intended to detect an inadmissible housing movement state, and with a motor controller, which is connected to the monitoring unit and which is intended to output power of the drive motor at the to at least reduce the inadmissible housing movement state.

It is in DE 10 2009 000 065 A1 propelling a spindle lock has been proposed, which allows opening of a drill chuck without operating an additional spindle lock by hand.

Disclosure of the invention

The invention is based on a handheld power tool device with a drive motor, a tool spindle, a handheld power tool housing, a monitoring unit, which is intended to detect an inadmissible housing movement state, and with a motor control, which is connected to the monitoring unit and which is intended to output power to at least reduce the drive motor in the inadmissible housing movement state.

It is proposed that the hand-held machine tool device have a torque lock, which is provided for the tool spindle in the rotational direction with the hand-held power tool housing in the inadmissible housing movement state depending on a torque transmitted to the tool spindle. A “drive motor” is to be understood in particular as a motor which, in at least one operating state, drives the tool spindle, in particular via a gear of the hand-held machine tool device, in a rotating manner. In particular, a "tool spindle" is to be understood as a component which, in at least one operating state, transmits the torque transmitted from the drive motor to the tool spindle, in particular directly to a tool holder of the hand-held power tool device. The tool spindle preferably fastens the tool holder rotatably relative to the handheld power tool housing. A “handheld power tool housing” is to be understood in particular as a housing that connects at least one stator of the drive motor and a handle of the handheld power tool device in a rotationally fixed manner. In particular, a “monitoring unit” is to be understood as a unit that is intended to monitor a force transmitted from the handle to an operator, an acceleration of the handle and / or a movement of the handle. Such a monitoring unit is for example in DE 196 41 618 A1 described. As an alternative or in addition, the monitoring unit could detect a current flowing through the drive motor and / or a power consumed by the drive motor in order to detect the inadmissible housing movement state. “Provided” is to be understood in particular to be specially programmed, designed and / or equipped. An “impermissible housing movement state” is to be understood in particular to mean an operating state in which the handheld power tool housing has a rotational movement about an axis of rotation of the tool spindle, in which a safe grip of an operator on the handheld power tool housing is unlikely. The monitoring unit and / or the motor control have a threshold value of an acceleration and / or a change in orientation of the handheld power tool housing, the exceeding of which indicates the inadmissible housing movement state. In particular, the inadmissible state of housing movement is caused by an uncontrolled blocking situation. In particular, an “uncontrolled blocking case” is to be understood to mean an operating state in which an insert tool, for example a drill, which is driven in rotation during a working process is caught in a workpiece, the holding force currently applied by the operator being too low to accelerate the rotation and / or a rotary movement of the hand machine tool housing to prevent more than an uncritical value. In particular, in the case of the impermissible housing movement state, a rotational energy of one Drive train of the handheld power tool device is converted into a rotational energy of the handheld power tool housing and elements of the handheld power tool device that are fixedly connected to the handheld power tool housing. A “motor control” is to be understood in particular as a device which at least controls and / or regulates in particular a power output by the drive motor in the direction of the tool holder. In particular, a "power output of the drive motor" is to be understood as a power which the drive motor delivers in the direction of the tool spindle, in particular to the torque lock or advantageously to the transmission. In particular, the drive motor delivers the power in the form of a rotary movement. In particular, “at least reduce” should be understood to mean that the motor control, in the inadmissible housing movement state, reduces a torque given off by the drive motor in the direction of the tool spindle, stops a torque output and / or causes a torque in the opposite direction in the direction of the tool spindle. The drive motor is preferably short-circuited for stopping and / or advantageously switched off. In particular, a "torque lock" is to be understood to mean a device which is intended to establish a connection for transmitting a torque between the tool spindle and the handheld power tool housing in at least one operating state. The torque lock is preferably at least substantially corresponding to that in FIG DE 10 2009 000 065 A1 disclosed spindle lock driving and / or in particular in accordance with another spindle lock driving which appears to be useful to the person skilled in the art. The torque lock preferably connects the tool spindle directly to the handheld power tool housing in at least one operating state. Alternatively or additionally, the torque lock could connect the tool spindle to the handheld power tool housing in at least one operating state via the gear and / or via the tool holder. The torque lock is preferably designed to be usable in both possible directions of rotation of the tool holder in the event of uncontrolled locking cases. Alternatively, the torque lock could be designed to be usable in one of the possible directions of rotation of the tool holder, particularly in clockwise rotation, in the event of uncontrolled blocking. “In the case of the inadmissible housing movement state” is to be understood in particular to mean that first the motor control reduces the power output of the drive motor and then advantageously the torque lock connects the tool spindle to the handheld power tool housing. The phrase "connect in the direction of rotation" should in particular be understood to mean that the Torque lock transmits a force that counteracts a rotational movement of the hand machine tool housing relative to the tool spindle, which is non-rotatably connected to the workpiece in the inadmissible housing movement state. In particular, “dependent on a torque” should be understood to mean that the torque lock reacts to a change in torque, advantageously to a change in torque, which is caused in particular by the reduction in the power output of the drive motor. The torque lock preferably connects the tool spindle and the handheld power tool housing when the handheld power tool housing and the tool spindle have a rotational movement relative to one another, a torque emanating from the drive motor counteracting the rotational movement of the handheld power tool housing. In particular, the torque emanating from the drive motor counteracts the rotary movement when the drive motor is stopped by friction or when the drive motor has changed a drive direction. The torque lock preferably connects the tool spindle to the handheld power tool housing when the torque between the drive motor and the tool spindle is essentially zero. The torque lock is preferably provided to connect the tool spindle to the hand-held machine tool housing in a purely mechanically dependent manner, in particular purely mechanically, based on the torque transmitted to the tool spindle. The torque lock preferably only has mechanically active components. As an alternative or in addition, the torque lock could record the torque electrically, in particular in a way that appears to be useful to the person skilled in the art. A “torque transmitted from the drive motor to the tool spindle” is to be understood in particular as a torque which acts at a point between the drive motor and the tool holder, but preferably a torque acting at the torque lock. The inventive design of the hand-held power tool device allows movement of the hand-held power tool housing to be limited particularly effectively in the case of the inadmissible housing movement state. This enables a particularly controllable hand tool to be provided.

In a further embodiment, it is proposed that the torque lock transmit torque from the drive motor to the tool spindle during operation, so that the dependence on the torque can be achieved in terms of design. In particular, “to transmit a torque from the drive motor to the tool spindle” should be understood to mean that the torque during operation from the drive motor, in particular via the transmission, to the torque lock acts and acts from the torque lock, advantageously directly, on the tool spindle. The torque lock is preferably arranged between the gear and the tool spindle. Alternatively, the torque lock could be arranged between the drive motor and the transmission. The torque lock is preferably formed separately from the transmission. Alternatively, the torque lock could be formed at least partially in one piece with the transmission.

Furthermore, it is proposed that the torque lock automatically disconnects a connection between the tool spindle and the hand-held power tool housing during a restart, depending in particular on the torque transmitted to the tool spindle, which makes the restart particularly easy. “Recommissioning” is to be understood in particular to mean an operating state after the tool spindle has come to a standstill by connecting the tool spindle to the handheld power tool housing, in which the motor controller starts to output the drive motor, in particular because the operator actuates an operating element. In particular, “automatically solve” is to be understood to mean that the operator only has to actuate the control element for controlling the drive motor for a work process that follows the impermissible housing movement state. In particular, the torque lock is provided to release the connection between the tool spindle and the handheld power tool housing as a function of a torque of the drive motor.

Furthermore, it is proposed that the motor controller be provided to change a drive direction of the drive motor in the inadmissible housing movement state, as a result of which movement of the handheld power tool housing can be reduced particularly quickly in the inadmissible housing movement state. “Change a drive direction of the drive motor” is to be understood in particular to reverse a sense of direction of a torque output by the drive motor in the direction of the tool spindle.

Furthermore, it is proposed that the motor control stop the power output of the drive motor at the latest when the housing movement state is inadmissible as soon as the tool spindle is stationary relative to the handheld power tool housing, as a result of which wear can be avoided. In particular, "stop the power output of the drive motor" should be understood to mean that the drive motor, as soon as the tool spindle is stationary relative to the hand machine tool housing, no torque is produced in the direction of the tool spindle. "Standstill" is to be understood here in particular to mean an operating state in which the tool spindle is stationary relative to the handheld power tool housing.

In addition, it is proposed that the torque lock act directly on the tool spindle, whereby advantageous positioning and great effectiveness can be achieved. In this context, “direct” is to be understood in particular to mean that the torque lock is at least temporarily in contact with the tool spindle and / or is at least partially formed in one piece with the tool spindle.

Furthermore, it is proposed that the torque lock have at least one clamping body, which clamps the tool spindle when the housing movement is inadmissible, as a result of which particularly high torques can be transmitted with little wear via the torque lock. A “clamp body” is to be understood in particular as a component of the torque lock that creates a connection between the handheld power tool housing and the tool spindle by clamping between two surfaces. The clamping bodies are preferably designed as rolling bodies. Alternatively or additionally, the torque lock could have clamping bodies which are slidably mounted for the connection between the handheld power tool housing and the tool spindle.

In an advantageous embodiment of the invention, it is proposed that the hand-held power tool device comprise a gearbox, which is arranged between the torque lock and the drive motor, whereby advantageous positioning and great effectiveness are possible. A “gearbox” is to be understood in particular as a device which is intended to translate a rotational speed of a rotor of the drive motor into at least one rotational speed which differs from the rotational speed, in particular the tool spindle.

drawing

Further advantages result from the following description of the drawing. In the drawing, an embodiment of the invention is shown. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into useful further combinations.

Fig. 1

eine Handwerkzeugmaschine mit einer erfindungsgemäßen Handwerkzeugmaschinenvorrichtung in einer schematischen Schnittdarstellung,

Fig. 2

einen Antriebsmotor, eine Überwachungseinheit und eine Motorsteuerung der Handwerkzeugmaschinenvorrichtung aus Figur 1 in einer schematischen Darstellung,

Fig. 3

eine Momentensperre der Handwerkzeugmaschinenvorrichtung aus Figur 1 in einer Schnittdarstellung und

Fig. 4

die Momentensperre in einer perspektivischen Explosionsdarstellung.

Show it:

Fig. 1

a handheld power tool with a handheld power tool device according to the invention in a schematic sectional view,

Fig. 2

a drive motor, a monitoring unit and a motor controller of the hand machine tool device Figure 1 in a schematic representation,

Fig. 3

a moment lock of the hand machine tool device Figure 1 in a sectional view and

Fig. 4

the moment lock in a perspective exploded view.

Description of the embodiment

Figure 1 shows a handheld power tool 28 with a handheld power tool device 10 according to the invention and a battery coupling means 30. The handheld power tool 28 is designed as a drill driver. Alternatively or additionally, the handheld power tool 28 could be designed as an impact drill and / or as a hammer drill. The handheld power tool 28 has a hammer mechanism, not shown in detail here. Alternatively, the handheld power tool 28 could have a catch mechanism. The battery coupling means 30 is provided to receive an operating energy from a handheld tool battery 32 coupled to the battery coupling means 30.

The handheld power tool device 10 comprises a drive motor 12, a tool spindle 14, a handheld power tool housing 16, a monitoring unit 18, a motor control 20, a torque lock 22, a gear 26 and a tool holder 34. A rotor 36 of the drive motor 12 drives during operation the transmission 26. The transmission 26 is arranged between the torque lock 22 and the drive motor 12. The transmission 26 drives parts of the torque lock 22. The torque lock 22 drives the tool spindle 14. The tool spindle 14 is rotatably connected to the tool holder 34. The handheld power tool housing 16 is pistol-shaped. The handheld power tool housing 16 connects a stator 38 of the drive motor 12, part of the transmission 26 and part of the torque lock 22 to one another in a rotationally fixed manner.

The tool holder 34 is designed as a drill chuck. Alternatively, the tool holder 34 could be designed as an SDS tool holder. The tool holder 34 is provided to fasten an insert tool 48 in a rotationally fixed manner. The tool holder 34 is provided to release the insert tool 48 by an unlocking force applied in the circumferential direction by an operator. Alternatively, the tool holder 34 could be provided to release the insert tool 48 by an unlocking force applied by an operator in the axial direction.

In the Figure 2 Monitoring unit 18, shown in more detail, is intended to detect an impermissible housing movement state. For this purpose, the monitoring unit 18 has an acceleration sensor 40, a current sensor 42, a voltage sensor 44 and an evaluation unit 46. The acceleration sensor 40 detects at least one rotational acceleration about an axis of rotation of the insert tool 48. The current sensor 42 detects a current drawn by the drive motor 12. The voltage sensor 44 detects a voltage that is present at the drive motor 12. The evaluation unit 46 recognizes through the sensors of the monitoring unit 18 whether there is an impermissible housing movement state. The monitoring unit 18 is connected to the motor controller 20 and transmits a parameter to the motor controller 20 with information as to whether there is an impermissible housing movement state. The monitoring unit 18 can be formed at least partially in one piece with the engine control 20.

The motor controller 20 is provided to control the drive motor 12 during operation. The motor controller 20 is connected to an operating unit 50 of the hand machine tool device 10. An operator controls a speed and a direction of rotation of the tool holder 34 via the operating unit 50. The motor controller 20 is provided to drive the drive motor 12 with two different torque directions drive. When there is an improper housing movement condition, the motor controller 20 reduces power output of the drive motor 12 by reversing the torque direction of the drive motor 12. As soon as the tool spindle 14 is stationary relative to the handheld power tool housing 16, the motor controller 20 stops the power output of the drive motor 12.

The in the Figures 3 and 4 Torque lock 22, shown in more detail, transmits a torque from the drive motor 12 to the tool spindle 14 during operation. For this purpose, the torque lock 22 has drivers 52, which transmit the torque to a driving structure 54 of the tool spindle 14 during operation. The torque lock 22 thus acts directly on the tool spindle 14 during operation. The connection between the drivers 52 and the driver structure 54 has a defined play in the direction of rotation. The drivers 52 of the torque lock 22 are non-rotatably connected to part of the transmission 26. Here, the drivers 52 are integrally formed with a planet carrier 56 of the transmission 26.

Furthermore, the torque lock 22 comprises clamping bodies 24, a locking ring 58, clamping surfaces 60 and clamping body guide means 62. The clamping bodies 24 are designed as rolling bodies. The locking ring 58 is non-rotatably connected to the hand tool machine housing 16. The clamping surfaces 60 are formed by part of a surface of the tool spindle 14. The clamping bodies 24 are each arranged between the locking ring 58 and one of the clamping surfaces 60. The clamping body guide means 62 are connected to the drivers 52 in a rotationally fixed manner. The clamping body guide means 62 are each partially arranged between two of the clamping bodies 24. During an operation, that is, when the drive motor 12 transmits a torque in the direction of the tool spindle 14, the clamping body guide means 62 guide the clamping bodies 24 and thus prevent the clamping bodies 24 from becoming jammed between the clamping surfaces 60 and the locking ring 58.

During the operation, the drive motor 12 rotates the tool spindle 14 relative to the hand-held power tool housing 16 by means of a torque. In the event of an impermissible housing movement state, the insert tool 48 hooks into a workpiece. The handheld power tool housing 16 is accelerated in rotation by the torque of the drive motor 12. The monitoring unit 18 recognizes the impermissible state of the housing movement and outputs a parameter with this information to the engine control 20. The engine control 20 detects the parameter. Thereupon, the motor controller 20 changes the drive direction of the drive motor 12. The power output of the drive motor 12 is reduced. The torque transmitted from the drive motor 12 or the gear 26 to the tool spindle 14 is thereby reduced to zero. From a point in time at which the transmitted torque is reduced to zero, the hooked insert tool 48 rotates the tool spindle 14 relative to the hand tool machine housing 16 by means of a changed torque. The changed torque starts from the insert tool 48. The tool spindle 14 transmits the torque via the torque lock 22 to the drive motor 12, the drive motor 12 counteracts the torque. The hand tool machine housing 16 has kinetic energy at this time.

The connection between the drivers 52 and the driver structure 54 has a defined play in the direction of rotation. Due to the change in the torque and the play, the drivers 52 and the driver structure 54 move relative to one another. As a result, the clamping body guide means 62 move relative to the clamping surfaces 60. The clamping body guide means 62 release the clamping bodies 24 to such an extent that they clamp between the clamping surfaces 60 arranged on the tool spindle 14 and the locking ring 58 when the housing movement is inadmissible. The clamping bodies 24 briefly slide over the clamping surfaces 60, as a result of which the kinetic energy of the hand tool machine housing 16 is partially converted into thermal energy. Thus, the torque lock 22 is provided to connect the tool spindle 14 in the direction of rotation to the hand-held machine tool housing 16 depending on a torque transmitted to the tool spindle 14 in the inadmissible housing movement state.

The motor controller 20 stops outputting the drive motor 12 as soon as the tool spindle 14 is stationary relative to the handheld power tool housing 16. The motor controller 20 ignores operator inputs via the operating unit 50 from the detection of the impermissible housing movement state until it is put back into operation. The handheld power tool device 10 can then be put into operation again. The torque lock 22 automatically releases a connection between the tool spindle 14 and the handheld power tool housing 16 when it is restarted. A torque applied to the tool spindle 14 originates from the drive motor 12. The clamp body guide means 62 move the clamp body 24 from a blocking position.

Claims (12)

1. Portable power tool device having a drive motor (12), a tool spindle (14), a portable power tool housing (16), a monitoring unit (18), which is intended to identify an impermissible housing movement state, and having a motor controller (20), which is connected to the monitoring unit (18) and is intended at least to reduce a power output of the drive motor (12) in the event of the impermissible housing movement state, characterized by a torque lock (22) having drivers (52), which transmit the torque to an entrainment structure (54) during operation, and at least one clamping body (24), which clamps the tool spindle (14) in the event of the impermissible housing movement state, wherein, in the event of the impermissible housing movement state, first of all the motor controller (20) reduces the power output of the drive motor (12) and subsequently the torque lock (22) connects the tool spindle (14) to the portable power tool housing in a manner dependent on a torque transmitted to the tool spindle (14) and thus reacts to a change in torque of the drive motor (12).
2. Portable power tool device according to Claim 1, characterized in that, upon restarting, the torque lock (22) automatically releases a connection between the tool spindle (14) and the portable power tool housing (16), wherein a torque applied to the tool spindle (14) is output by the drive motor (12).
3. Portable power tool device according to either of the preceding claims, characterized in that clamping-body guide means (62) are each arranged partially between two clamping bodies (24) and are intended to move the clamping bodies (24) out of a blocking position.
4. Portable power tool device according to one of the preceding claims, characterized in that the motor controller (20) is intended to change a drive direction of the drive motor (12) in the event of the impermissible housing movement state.
5. Portable power tool device according to Claim 4, characterized in that, in the event of the impermissible housing movement state, the motor controller (20) stops the power output of the drive motor (12) at the latest as soon as the tool spindle (14) is stationary relative to the portable power tool housing (16).
6. Portable power tool device according to one of the preceding claims, characterized in that the torque lock (22) acts directly on the tool spindle (14).
7. Portable power tool device according to one of the preceding claims, characterized by a transmission (26), which is arranged between the torque lock (22) and the drive motor (12).
8. Portable power tool device according to one of the preceding claims, characterized in that the torque lock (22) has clamping faces (60), which are formed by a part of a surface of the tool spindle (14).
9. Portable power tool device according to Claim 8, characterized in that the clamping bodies (24) are each arranged between the locking ring (58) and one of the clamping faces (60).
10. Portable power tool device according to one of the preceding claims, characterized in that the torque lock has drivers, which transmit the torque to an entrainment structure of the tool spindle during operation.
11. Portable power tool device according to one of the preceding claims, characterized in that the locking ring (58) is connected to the portable power tool housing (16) in a rotationally fixed manner.
12. Portable power tool, in particular drill driver, having a portable power tool device (10) according to one of the preceding claims.

Images