CN1974141A - Reversing unit for a hand-held power tool - Google Patents

Abstract

The invention relates to a reversing unit for a hand-held power tool with a reversing device (38) for reversing an output direction (34, 36) in which a tool unit (22) can be driven by a The drive unit (28) drives the rotation at least half a turn. The invention proposes that the reversing unit of the hand-held power tool has a protection unit (40), which is designed to reverse the drive of the tool unit (22) in a driven direction (34, 36) The directional balancing drive is at least partially balanced at least partially automatically.

Description

Reversing unit for hand-held machine tools

technical field

The invention relates to a hand-held power tool reversing unit with a reversing device. Furthermore, the invention relates to a hand power tool with such a hand power tool reversing unit.

Background technique

Hand-held power tools, in particular drilling machines with an additional screw function, are known. In such a hand power tool, the tool can be rotationally driven in two different output directions. For reversing the output direction, the hand-held power tool is provided with a mechanical reversing device which includes an operating element. After the output direction has been reversed by the operator, the drive of the tool in the reverse output direction is initiated by additionally actuating the drive switch.

Contents of the invention

The invention relates to a reversing unit for a hand-held power tool with a reversing device for reversing the output direction in which the tool unit can be driven by a drive unit Rotate at least half a turn.

The invention proposes that the reversing unit of the hand-held power tool has a protective unit, which is designed to at least partially automate the drive of the tool unit in a driven direction by means of a compensating drive in the opposite direction. ground balance. This makes it possible to achieve a high degree of safety when operating a hand-held power tool, in particular when operating a drilling machine. In particular, the balanced drive prevents hair, body parts and/or clothing from being pulled strongly into the rotating cutter unit, which could lead to serious injuries to the operator. In this sense, a "tool unit" is to be understood in particular as an element or component unit of a hand-held power tool which is connected in a rotationally fixed manner to the output shaft of the hand-held power tool, for example a tool, a tool holder , an additional unit for insertion into the tool holder, etc.

The protective unit is advantageously designed to automatically switch on the compensating drive as a function of a stop signal which signals a stop of the drive in the output direction. If the operator perceives a hazard, such as hair, clothing and/or body parts being pulled in, when the knife unit is driven, this enables a rapid activation of the balancing drive. Protection modes of the hand-held power tool are conceivable in which a stop signal is generated, for example by actuating an emergency circuit breaker or by releasing a drive switch.

In a further embodiment of the invention it is provided that the protective unit is provided for automatically switching on the compensating drive in the opposite direction after a pre-set rotational path of the tool unit in one output direction has been carried out. This makes it possible to achieve a high level of safety when operating the hand-held power tool, which is especially suitable for domestic work with children. For example, a child-proof mode can be provided in which a small swivel stroke of the knife unit is set before operation and the balancing drive is switched on automatically without the intervention of the child after the swivel stroke has been carried out. The swivel path can be configured as a swivel angle or as a number of revolutions of the tool unit.

Furthermore, it is proposed that the protective unit is provided to at least substantially balance the rotational path performed by the tool unit during a drive by the balancing drive. This is advantageously suitable for the use of hand-held power tools which work with small rotational strokes of the tool unit, such as in particular in household work with children. When the tool unit is driven in the opposite direction after performing at least 70%, preferably more than 80%, especially more than 90%, of the rotational travel, the rotational travel is preferably substantially balanced.

In a further embodiment of the invention it is provided that the reversing unit of the hand-held power tool has an adjusting unit which is provided for adjusting the rotational path of the tool unit. This makes it possible to achieve a high level of operating comfort for the hand-held power tool. The maximum rotational travel of the drive in the output direction and/or the maximum rotational travel of the compensating drive in the reverse direction can be adjusted by means of the adjusting unit.

Furthermore, it is proposed that the reversing unit of the hand-held power tool comprises an adjusting unit which is provided for setting the protective mode, whereby a high degree of flexibility in the use of the hand-held power tool can be achieved.

Another embodiment provides that the reversing device is provided for reversing the driven direction during operation of the drive unit. This advantageously reduces delays when changing the output direction, which delays are attributable to the inertia of the drive element when the drive unit is stopped and started.

In this context, it is provided that the reversing device comprises a clutch device, whereby existing and cost-effective components can be used for the reversing device.

The clutch device preferably has at least two clutch elements which are arranged to rotate in opposite directions relative to one another during operation of the drive unit. A particularly simple construction of the clutch arrangement can thus be achieved. For example, a driven element which is connected in a rotationally fixed manner to the tool unit can be displaceably arranged between the clutch elements. Depending on the desired output direction, the driven element is coupled to one of the clutch elements during a reversing change.

An advantageous flexibility when using the hand-held power tool is achieved if the protective unit can be switched on and off.

According to the invention, a hand-held power tool is also proposed, with a hand-held power tool reversing unit, which has a reversing device for reversing the driven direction, in which In the driving direction, the tool unit can be driven to rotate at least half a turn by a drive unit, wherein the reversing unit of the hand-held power tool has a protection unit, which is arranged to pass the drive of the tool unit in a driven direction The balancing drive in the opposite direction is at least partially balanced at least partially automatically.

Description of drawings

Further advantages emerge from the following description of the figures. An embodiment of the invention is shown in the drawing. The drawings, the description and the claims contain numerous features in combination. A professional can also expediently examine these features one by one and conclude in other meaningful combinations.

The accompanying drawings indicate:

Figure 1 is a side view of a drilling machine with some internal components,

An adjustment unit of the drilling machine in Fig. 2 Fig. 1, and

A clutch device of the drilling machine in Fig. 3 Fig. 1 .

Detailed ways

FIG. 1 shows a hand-held power tool 10 designed as a drilling machine. The hand power tool has a housing 12 with a handle 14 and a drive switch 16 . Furthermore, a tool holder 18 and a tool 20 fastened in the tool holder 18 can be seen. The tool holder 18 and the tool 20 form a tool unit 22 . The tool 20 is designed as a drill bit in this figure. The tool unit 22 is connected in a rotationally fixed manner to an output shaft 24 . The driven shaft is coupled via a transmission unit 26 to a drive unit 28 which includes an electric motor 30 and a drive shaft 32 . The tool unit 22 can be driven by the drive unit 28 via the driven shaft 24 in a driven direction 34 (clockwise) and in a driven direction 36 opposite to the driven direction 34 (clockwise) by at least half a turn. When the hand-held power tool 10 is used as a drilling machine, the tool unit 22 is driven in the driven direction 34 .

Furthermore, hand power tool 10 is provided with a hand power tool reversing unit 37 . The hand-held power tool reversing unit has a reversing device 38 which is arranged in the transmission unit 26 and serves to reverse the output direction 34 or 36 during operation of the hand-held power tool 10 . The structure and operating principle of the reversing device 38 are described in detail with reference to FIG. 3 . The hand-held power tool reversing unit 37 additionally includes a protective unit 40 , which is provided for driving the tool unit 22 in the output direction 34 or 36 via a drive in the opposite output direction 36 or 34 . The balancing drive is at least partially balanced at least partially automatically. For this purpose, a protective unit 40 is provided with an electronic control unit 42 , which is electrically connected to the electric motor 30 , the reversing device 38 and a sensor unit 44 assigned to the drive switch 16 . Furthermore, the control unit 42 is connected to an adjustment unit 46 which is integrated in the handle 14 .

The control unit 42 is programmable by the operator via the adjustment unit 46 shown in front view in FIG. 2 . The adjustment unit has operating elements 48 and an LED indicator 50 . The operator can switch the protection unit 40 on or off via the adjustment unit 46 . When the protective unit 40 is switched off, the control unit 42 has no influence on the drive unit 28 and the reversing device 38 , wherein the hand-held power tool 10 can be operated like a conventional drilling or screwing machine. With the protective circuit 40 switched on, the operator can select a specific protective mode of the protective unit 40 by means of the operating element 48 and the LED indicator 50 .

It is initially assumed that hand power tool 10 is used by a child for domestic work, for example to drill a workpiece. The operator can select the child protection mode by means of the adjustment unit 46 . When operating in this child protection mode, which corresponds to a high safety level, the knife unit 22 is driven with a predetermined limited number of revolutions in the output direction 34 when the drive switch 16 is actuated. This number of revolutions can also be entered by the operator via the operating element 48 . After a predetermined rotational path of the tool unit 22 in the output direction 34 has been carried out, the control unit 42 automatically switches on the balancing drive of the tool unit 22 . To this end, the control unit 42 controls the reversing device 38 and the drive unit 28 . In this balancing drive, the tool unit 22 is driven in the driven direction 36 at the same predetermined rotational speed. After the balancing drive has been terminated, the control unit 42 switches on again the drive in the output direction 34 with a predetermined number of revolutions, which is then balanced again by a balancing drive in the output direction 36 , etc. This cycle of driving and balancing driving is repeated until the child releases the driver switch 16 . In this child protection mode, the risk of body parts and/or clothing being pulled in violently is reduced by limiting the number of revolutions—advantageously to a small number of revolutions—and switching on the balancing drive fully automatically by the control unit 42 .

Furthermore, it is also conceivable to switch from the child protection mode to another mode by means of an access authorization, for example by entering a code by means of the adjustment unit 46 . This prevents children from deactivating the child protection mode specifically selected for their domestic work and using hand-held power tool 10 in a mode with a lower safety level.

It is now assumed that hand power tool 10 is used by an adult. By means of the adjusting unit 46 , the user can select a corresponding protection mode, which corresponds to a medium security level. In this protection mode, the tool unit 22 can be driven in the output direction 34 without limitation of the number of revolutions. After this drive has stopped, a compensating drive of the tool unit 22 in the driven direction 36 is started. This is achieved by means of a sensor unit 44 and a control unit 42 connected to the drive switch 16 . If the operator releases the drive switch 16 during the drive, for example in a dangerous situation, the sensor unit 44 sends a stop signal to the control unit 42 . The control unit then controls the reversing device 38 and the drive unit 28 , whereby the balancing drive is switched on. In this balancing drive, the tool unit 22 is driven at a predetermined number of revolutions in the driven direction 36 . This number of revolutions can also be predetermined by the operator via the regulating unit 46 .

Furthermore, the protection unit 40 is provided with another protection mode, which corresponds to a low security level. In this protection mode, a stop signal can be transmitted to the control unit 42 and the balancing drive can thus be started by the operator actuating an emergency circuit breaker 52 . Hand-held power tool 10 can be used by an operator like a conventional hand-held power tool until emergency disconnector 52 is actuated.

The structure and operating principle of the reversing device 38 are explained with the aid of FIG. 3 . The reversing device 38 is provided for reversing the driven direction of the tool unit 22 during operation of the drive unit 28 . To this end, the reversing device 38 comprises a clutch device 54 with a first clutch element 56 configured as a clutch disc, which can be driven in rotation by the drive unit 28 in the output direction 34 or 36 a second clutch element 58 designed as a clutch disc, which can be driven simultaneously in rotation by the drive unit 28 in the output direction 36 or 34 ; Furthermore, the clutch device 54 also has a driver element 60 which is connected in a rotationally fixed manner to the output shaft 24 . The driver element is arranged displaceably in the axial direction 61 between the clutch elements 56 , 58 and is displaceable until it comes into contact with the first or second clutch element 56 , 58 . To this end, the driver element 60 is movable in translation in the axial direction 61 on the driven shaft 24 . The first clutch element 56 can be driven in rotation in the output direction 34 or 36 by the drive shaft 32 of the drive unit 28 via a transmission 62 . The second clutch element 58 can be driven in rotation in the output direction 36 or 34 via a toothed intermediate shaft 64 . The driver element 60 passes through the first clutch element 56 . In order to drive the drive element 60 in a translational movement, the reversing device 38 is provided with a displacement unit 66 which is controlled by the control unit 42 when reversing the driven direction. For this purpose, the displacement unit 66 is connected to the control unit 42 via an electrical connection 68 .

List of Reference Designators

10 Hand-held machine tool 40 Protection unit

12 Housing 42 Control unit

14 handle 44 sensor unit

16 Drive switch 46 Adjustment unit

18 tool holder 48 operating elements

20 Tool 50 LED indicator

22 Tool unit 52 Emergency circuit breaker

24 Driven shaft 54 Clutch device

26 Transmission unit 56 Clutch element

28 drive unit 58 clutch element

30 Electric Motor 60 Driving Components

32 Drive shaft 62 Transmission

34 Driven direction 64 Intermediate shaft

36 Driven direction 66 Shift unit

37 Hand tool machine reversing unit 68 Connection device

38 Reversing device

Claims (11)

1. Hand-held power tool reversing unit with a reversing device (38) for reversing the driven direction (34, 36) in which the tool unit (22) can be driven by a drive unit ( 28) Drive to rotate at least half a turn, characterized in that a protection unit (40) is provided for driving the tool unit (22) in a driven direction (34, 36) through a reverse The balancing drive in the direction is at least partially balanced at least partially automatically. 2. The hand-held power tool reversing unit according to claim 1, characterized in that the protection unit (40) is configured to automatically switch on the balancing drive as a function of a stop signal, which sends out a driven direction ( 34, 36) on the signaling of drive stop. 3. The hand-held power tool reversing unit according to claim 1 or 2, characterized in that the protective unit (40) is provided for switching the tool unit (22) in a driven direction (34, 36) The balancing drive in the reverse direction is automatically switched on after the preadjusted swivel path has been executed. 4. The reversing unit for the hand-held power tool as recited in claim 1, characterized in that the protective unit (40) is designed to drive the rotary stroke performed by the tool unit (22) in one drive by means of a balancing drive is at least substantially balanced. 5. The hand-held power tool reversing unit according to claim 1, characterized in that an adjusting unit (46) is provided which is provided for adjusting the rotational travel of the tool unit (22). 6. The reversing unit for the hand-held power tool as claimed in claim 1, characterized in that an adjusting unit (46) is provided which is provided for adjusting the protection mode. 7. The reversing unit for the hand-held power tool as claimed in claim 1, characterized in that the reversing device (38) is designed to set the output direction (34, 36) during operation of the drive unit (28). ) commutation. 8. The hand-held power tool reversing unit according to claim 7, characterized in that the reversing device (38) comprises a clutch device (54). 9. The hand-held power tool reversing unit according to claim 8, characterized in that the clutch device (54) has at least two clutch elements (56, 58), which are arranged in the drive unit (28) Rotate in opposite directions relative to each other during operation. 10. The hand-held power tool reversing unit as claimed in claim 1, characterized in that the protective unit (40) can be switched on and off. 11. Hand tool machine with a hand tool machine reversing unit (37) having a reversing device (38) for reversing the driven direction (34, 36) , in the driven direction, the tool unit (22) can be driven by a drive unit (28) to rotate at least half a circle, and it is characterized in that: the hand-held power tool reversing unit (37) has a protection unit (40), the The protection unit is designed to at least partially balance the drive of the tool unit (22) in a driven direction (34, 36) at least partially automatically by means of a compensating drive in the opposite direction.

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