EP0199883A2 - Motor-driven hand tool - Google Patents

Motor-driven hand tool Download PDF

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Publication number
EP0199883A2
EP0199883A2 EP85810591A EP85810591A EP0199883A2 EP 0199883 A2 EP0199883 A2 EP 0199883A2 EP 85810591 A EP85810591 A EP 85810591A EP 85810591 A EP85810591 A EP 85810591A EP 0199883 A2 EP0199883 A2 EP 0199883A2
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EP
European Patent Office
Prior art keywords
motor
housing
bearing block
hand tool
gear shaft
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP85810591A
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German (de)
French (fr)
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EP0199883B1 (en
EP0199883A3 (en
Inventor
Werner Klingenbeck
Anton Neumaier
Hans-Jürgen Hoereth
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Hilti AG
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Hilti AG
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Publication date
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Publication of EP0199883A2 publication Critical patent/EP0199883A2/en
Publication of EP0199883A3 publication Critical patent/EP0199883A3/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
    • B25B23/00—Details of, or accessories for, spanners, wrenches, screwdrivers
    • B25B23/14—Arrangement of torque limiters or torque indicators in wrenches or screwdrivers
    • B25B23/147—Arrangement of torque limiters or torque indicators in wrenches or screwdrivers specially adapted for electrically operated wrenches or screwdrivers
    • 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

Definitions

  • the invention relates to a motor-operated hand tool with a housing, a motor arranged therein, a drive shaft set in rotation by the motor and a transmission arranged between the motor and the drive shaft.
  • Motor-operated hand tools are used for various purposes, such as drilling, grinding, sawing, milling and the like.
  • the reaction moment that occurs must be applied by the operator. Under normal circumstances this is easily possible. In special situations, such as when the tool suddenly jams or jams, this reaction moment can increase very quickly and very strongly. If the operator is not prepared for this, this can lead to accidents with more or less serious consequences.
  • Another known solution is to provide weakening points on the housing or on the handle of the hand tool, the deformation of which is measured, for example, by means of a strain gauge. It is therefore not the torque that is measured, but rather the resulting deformation of the housing or the handle. The results of such measurements can be falsified, for example, by the operator holding and guiding the hand tool not only by the handles, but by the housing. This method also does not enable the forces and moments that occur to be precisely determined.
  • the motor is movably mounted in the housing and is supported in the housing by at least one support bearing that receives the reaction torque of the electric motor.
  • the support bearing contains a pressure sensor made of electrically conductive plastic material, the electrical resistance of which changes depending on the pressure exerted.
  • the reaction torque occurring at the motor is measured with this solution. Since the required power is mainly achieved in hand tools for weight reasons due to a very high motor speed, the torque that occurs on the motor shaft is usually very small. This means that the reaction forces that occur on the motor are also relatively low. As a result of friction, inertia of the masses to be accelerated and the like, such disturbing influences occur that the reaction torque that actually occurs on the tool cannot be determined exactly at this point.
  • the invention has for its object to detect the reaction torque occurring on the tool accurately and without a time delay in a hand tool.
  • this object is achieved in that at least one gear shaft is mounted in a bearing block which is limitedly movable in the housing and is supported on the housing via electrical force measuring elements in the direction of the reaction forces which occur due to the torque transmission.
  • this transmission shaft is located in the "drive chain" of the transmission to the work spindle, the more precisely and quickly the torque occurring on the work spindle can be detected. In principle, it is sufficient to provide a single force measuring element. However, if the hand tool has a possibility of reversing the direction of rotation, two force measuring elements are preferably to be provided, which can be arranged, for example, in pairs opposite one another.
  • the bearing block is expediently rotatably mounted about a pivot axis running parallel to the gear shaft. Due to a pivot axis running parallel to the gear shaft, skewing of the gear shaft when moving it is practically avoided.
  • the gear shaft mounted in the bearing block is at least in engagement with another shaft via toothings.
  • the pivot axis of the bearing block advantageously runs coaxially with the axis of rotation of a gearwheel which is in engagement with the gear shaft.
  • the movement of the pedestal thus corresponds in principle to that of the web of a planetary gear
  • the effective displacement or swivel path in the area of the force measuring elements can be very small and usually only be a few tenths of a millimeter.
  • the force measuring elements are expediently made of piezoceramic for an accurate detection of the forces occurring.
  • an electrical charge is created when deformed by external force. This charge is proportional to the deformation or the force that occurs and can be converted into a voltage by suitable amplifiers.
  • the deformation path of such elements is a few ⁇ m.
  • the signal of the force measuring elements can be evaluated differently depending on the demands placed on the ease of use of the hand tool. For example, it is sufficient for certain applications to emit an optical or acoustic signal when a certain value is exceeded.
  • the signal from the force measuring elements is preferably used to generate control functions of the hand tool. In this case, for example, a clutch interrupting the torque transmission or a brake converting the still existing rotational energy of the transmission shafts into heat can be actuated.
  • the hand tool shown in FIGS. 1 and 2 has a housing, generally designated 1, to which a handle 2 is detachably connected.
  • the handle 2 has a push button 3 for switching the hand tool on and off and a feed line 4 for the electrical power supply of the hand tool.
  • a motor generally designated 5
  • a motor pinion 5a meshes with a gear 6.
  • the gearwheel 6 is firmly connected to a crankshaft, denoted overall by 7.
  • the crankshaft 7 is mounted on the one hand in a radial bearing 8 and on the other hand in a bearing plate 5b of the motor 5.
  • the radial bearing 8 is arranged in a bearing block, designated overall by 9, which is pivotably mounted in a bore la of the housing by means of an extension 9a.
  • the crankshaft 7 is provided with a toothing 7a which is in engagement with a spur gear 10.
  • the spur gear 10 is fixedly connected to a pinion shaft, designated overall by 11.
  • the pinion shaft 11 is also supported in the bearing block 9 via an angular contact ball bearing 12. Since the bearing block 9 is pivotally mounted about the axis of the crankshaft 7, the spur gear 10 and the toothing 7a remain unchanged in engagement with any pivoting movement of the bearing block 9.
  • the pinion shaft 11 carries a bevel pinion 11a which is in engagement with a bevel gear 13.
  • the bevel gear 13 is non-rotatably connected to a cylinder 14 and secured against axial displacement by means of a locking ring 15.
  • the cylinder 14 is mounted on the bevel gear 13 by means of a needle bearing 16 in the housing 1.
  • an excitation piston 17 is axially displaceably guided.
  • the excitation piston 17 is connected by means of a connecting rod 18 to a crank pin 7b of the crankshaft 7 and is set in a reciprocating motion when the crankshaft 7 is rotated.
  • a percussion piston 19 is also axially displaceably guided in the cylinder 14.
  • a drill 22 is inserted, which is acted upon by the percussion piston 19. The rotary movement is transmitted to the drill 22 via the cylinder 14.
  • FIG. 2 shows the projection 9a of the bearing block, which is pivotably mounted in the bore 1a of the housing 1. Since the crankshaft 7 is mounted coaxially in the bearing block 9, the position of the radial bearing 8 is not changed by the pivoting of the bearing block 9.
  • the part of the bearing block 9 which receives the angular contact ball bearing 12 is provided with two opposing support surfaces 9b.
  • Force measuring elements 23 arranged in recesses 1b of the housing 1 are stressed by the reaction forces arising during the torque transmission from the crankshaft 7 to the pinion shaft 11.
  • the signal from the force measuring elements 23 is used to generate control functions of the hand tool and can be used, for example, to switch off the energy supply, to actuate a clutch or brake and the like.
  • the force measuring elements 23 are preferably made of piezoceramic. Such elements generate an electrical charge when subjected to pressure, which can be converted into a voltage. By arranging two opposing force measuring elements 23, the forces occurring in both directions of rotation can be detected when the direction of rotation of the motor 5 is reversed.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Drilling And Boring (AREA)
  • Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)
  • Percussive Tools And Related Accessories (AREA)

Abstract

1. A motor-operated hand tool with a housing (1), a motor (5) arranged therein, a driving shaft (14) which is set rotating by the motor (5) and a gearing with torque measuring device arranged between the motor (5) and the driving shaft (14), characterised in that the torque measuring device comprises a gear shaft (11), a toothed wheel (6, 7a) which meshes with the gear shaft (11) and which is connected securely to a crankshaft (7) and a bearing block (9) which is mounted rotatably about the crankshaft which extends parallel to the gear shaft (11) as well as stands coaxially with the axis of rotation of the toothed wheel (6, 7a) and meshes with a motor pinion (5a), the gear shaft (11) and the crankshaft (7) being mounted in the bearing block (9) and the bearing block (9) being supported on the housing (1) by way of electrical force-measuring elements (23) made of piezoceramics.

Description

Die Erfindung betrifft ein motorisch betriebenes Handwerkzeug mit einem Gehäuse, einem darin angeordneten Motor, einer vom Motor in Drehung versetzten Antriebswelle und einem zwischen dem Motor und der Antriebswelle angeordneten Getriebe.The invention relates to a motor-operated hand tool with a housing, a motor arranged therein, a drive shaft set in rotation by the motor and a transmission arranged between the motor and the drive shaft.

Motorisch betriebene Handwerkzeuge werden für unterschiedliche Zwecke, wie Bohren, Schleifen, Sägen, Fräsen und dgl eingesetzt. Beim Arbeiten mit solchen Geräten von Hand muss das auftretende Reaktionsmoment von der Bedienungsperson aufgebracht werden. Unter normalen Umständen ist dies ohne weiteres möglich. In besonderen Situationen, wie beispielsweise bei einem plötzlich auftretenden Klemmen oder Blokkieren des Werkzeuges, kann dieses Reaktionsmoment sehr rasch und sehr stark ansteigen. Ist die Bedienungsperson darauf nicht vorbereitet, so kann dies zu Unfällen mit mehr oder weniger schweren Folgen führen.Motor-operated hand tools are used for various purposes, such as drilling, grinding, sawing, milling and the like. When working with such devices by hand, the reaction moment that occurs must be applied by the operator. Under normal circumstances this is easily possible. In special situations, such as when the tool suddenly jams or jams, this reaction moment can increase very quickly and very strongly. If the operator is not prepared for this, this can lead to accidents with more or less serious consequences.

Um dies zu vermeiden, ist es bekannt, die Handwerkzeuge mit Sicherheitskupplungen zu versehen, welche bei einem vorbe- st:nmten Wert die Drehmomentübertragung vom Motor auf das Werkzeug unterbrechen. Diese bei Ueberlast schaltenden Kupplungen sind meist relativ träge und können Unfälle somit sehr oft nicht wirksam verhüten. Ausserdem sind die meisten Kupplungen auf ein bestimmtes Auslösemoment ausgelegt, das den unterschiedlichen Arbeitsverhältnissen der Werkzeuge nicht angepasst werden kann.In order to avoid this, it is known to provide the hand tools with safety clutches, which are st: nmten value interrupt the torque transmission from the motor to the tool. These clutches that switch when overloaded are usually relatively slow and therefore very often cannot effectively prevent accidents. In addition, most couplings are designed for a specific triggering torque that cannot be adapted to the different working conditions of the tools.

Eine weitere bekannte Lösung besteht darin, am Gehäuse bzw am Handgriff des Handwerkzeuges Schwächungsstellen vorzusehen, deren Verformung beispielsweise mittels Dehnmessstreifens gemessen wird. Es wird somit nicht das Drehmoment, sondern die sich daraus ergebende Verformung des Gehäuses bzw des Handgriffes gemessen. Die Resultate solcher Messungen können beispielsweise dadurch verfälscht werden, dass die Bedienungsperson das Handwerkzeug nicht nur an den Handgriffen, sondern am Gehäuse hält und führt. Damit ermöglicht auch diese Methode keine genaue Bestimmung der auftretenden Kräfte und Momente.Another known solution is to provide weakening points on the housing or on the handle of the hand tool, the deformation of which is measured, for example, by means of a strain gauge. It is therefore not the torque that is measured, but rather the resulting deformation of the housing or the handle. The results of such measurements can be falsified, for example, by the operator holding and guiding the hand tool not only by the handles, but by the housing. This method also does not enable the forces and moments that occur to be precisely determined.

Bei einem weiteren bekannten Elektrowerkzeug ist der Motor im Gehäuse beweglich gelagert und über wenigstens ein das Reaktionsdrehmoment des Elektromotors aufnehmendes Stützlager im Gehäuse abgestützt. Das Stützlager enthält dabei einen Drucksensor aus elektrisch leitendem Kunststoffmaterial, dessen elektrischer Widerstand sich abhängig vom ausgeübten Druck ändert. Bei dieser Lösung wird somit im Prinzip das am Motor auftretende Reaktionsmoment gemessen. Da bei Handwerkzeugen die erforderliche Leistung hauptsächlich aus Gewichtsgründen aufgrund einer sehr hohen Motordrehzahl erzielt wird, ist das an der Motorwelle auftretende Drehmoment meist sehr klein. Somit sind auch die am Motor auftretenden Reaktionskräfte relativ gering. Infolge Reibung, Massenträgheit der zu beschleunigenden Massen und dgl treten derartige Störeinflüsse auf, dass an dieser Stelle das effektiv am Werkzeug auftretende Reaktionsmoment nicht genau bestimmt werden kann.In a further known power tool, the motor is movably mounted in the housing and is supported in the housing by at least one support bearing that receives the reaction torque of the electric motor. The support bearing contains a pressure sensor made of electrically conductive plastic material, the electrical resistance of which changes depending on the pressure exerted. In principle, the reaction torque occurring at the motor is measured with this solution. Since the required power is mainly achieved in hand tools for weight reasons due to a very high motor speed, the torque that occurs on the motor shaft is usually very small. This means that the reaction forces that occur on the motor are also relatively low. As a result of friction, inertia of the masses to be accelerated and the like, such disturbing influences occur that the reaction torque that actually occurs on the tool cannot be determined exactly at this point.

Der Erfindung liegt die Aufgabe zugrunde, bei einem Handwerkzeug das am Werkzeug auftretende Reaktionsmoment genau und ohne zeitliche Verzögerung zu erfassen.The invention has for its object to detect the reaction torque occurring on the tool accurately and without a time delay in a hand tool.

Gemäss der Erfindung wird diese Aufgabe dadurch gelöst, dass wenigstens eine Getriebewelle in einem im Gehäuse begrenzt beweglichen, in Richtung der durch die Drehmomentübertragung auftretenden Reaktionskräfte über elektrische Kraftmesselemente am Gehäuse abgestützten Lagerbock gelagert ist.According to the invention, this object is achieved in that at least one gear shaft is mounted in a bearing block which is limitedly movable in the housing and is supported on the housing via electrical force measuring elements in the direction of the reaction forces which occur due to the torque transmission.

Je näher sich diese Getriebewelle in der "Antriebskette" des Getriebes an der Arbeitsspindel befindet, desto genauer und rascher kann das an der Arbeitsspindel auftretende Drehmoment erfasst werden. Im Prinzip genügt es, ein einziges Kraftmesselement vorzusehen. Falls das Handwerkzeug jedoch eine Möglichkeit zur Drehrichtungsumkehr aufweist, sind vorzugsweise zwei Kraftmesselemente vorzusehen, die beispielsweise paarweise einander gegenüberliegend angeordnet sein können.The closer this transmission shaft is located in the "drive chain" of the transmission to the work spindle, the more precisely and quickly the torque occurring on the work spindle can be detected. In principle, it is sufficient to provide a single force measuring element. However, if the hand tool has a possibility of reversing the direction of rotation, two force measuring elements are preferably to be provided, which can be arranged, for example, in pairs opposite one another.

Für gewisse Anwendungen genügt es, Bewegungen des Lagerbockes durch Vorsehen von Betriebsspiel zu ermöglichen. Da es dabei nicht möglich ist, den Lagerbock genau zu führen, ist zweckmässigerweise der Lagerbock um eine parallel zur Getriebewelle verlaufende Schwenkachse drehbar gelagert. Durch eine parallel zur Getriebewelle verlaufende Schwenkachse wird ein Schiefstellen der Getriebewelle bei deren Verschieben praktisch vermieden.For certain applications, it is sufficient to enable movements of the bearing block by providing operating play. Since it is not possible to guide the bearing block precisely, the bearing block is expediently rotatably mounted about a pivot axis running parallel to the gear shaft. Due to a pivot axis running parallel to the gear shaft, skewing of the gear shaft when moving it is practically avoided.

Die im Lagerbock gelagerte Getriebewelle steht zumindest mit einer weiteren Welle über Verzahnungen im Eingriff. Um durch das Schwenken des Lagerbockes die Eingriffsverhältnisse an den Zahnflanken nicht zu verändern, verläuft vorteilhafterweise die Schwenkachse des Lagerbockes koaxial zur Drehachse eines mit der Getriebewelle in Eingriff stehenden Zahnrades. Die Bewegung des Lagerbockes entspricht somit im Prinzip derjenigen des Steges eines Planetengetriebes. Der effektive Verschiebeweg bzw Schwenkweg im Bereich der Kraftmesselemente kann sehr gering sein und meistens nur einige Zehntelsmillimeter betragen.The gear shaft mounted in the bearing block is at least in engagement with another shaft via toothings. In order not to change the engagement conditions on the tooth flanks by pivoting the bearing block, the pivot axis of the bearing block advantageously runs coaxially with the axis of rotation of a gearwheel which is in engagement with the gear shaft. The movement of the pedestal thus corresponds in principle to that of the web of a planetary gear The effective displacement or swivel path in the area of the force measuring elements can be very small and usually only be a few tenths of a millimeter.

Für eine genaue Erfassung der auftretenden Kräfte bestehen die Kraftmesselemente zweckmässigerweise aus Piezokeramik. In solchen aus Piezokeramik bestehenden Kraftmesselementen entsteht bei Verformung durch äussere Krafteinwirkung eine elektrische Ladung. Diese Ladung ist proporticnal zur Verformung bzw zur auftretenden Kraft und kann durch geeignete Verstärker in eine Spannung umgesetzt werden. Der Verformungsweg solcher Elemente beträgt einige µm.The force measuring elements are expediently made of piezoceramic for an accurate detection of the forces occurring. In such force measuring elements made of piezoceramic, an electrical charge is created when deformed by external force. This charge is proportional to the deformation or the force that occurs and can be converted into a voltage by suitable amplifiers. The deformation path of such elements is a few µm.

Je nach den an den Bedienungskomfort des Handwerkzeuges gestellten Ansprüchen kann das Signal der Kraftmesselemente unterschiedlich ausgewertet werden. So genügt es beispielsweise für gewisse Anwendungen, bei Ueberschreiten eines bestimmten Wertes ein optisches oder akustisches Signal abzugeben. Vorzugsweise dient das Signal der Kraftmesselemente der Erzeugung von Steuerfunktionen des Handwerkzeuges. Dabei kann beispielsweise eine die Drehmomentübertragung unterbrechende Kupplung oder eine die noch vorhandene Rotationsenergie der Getriebewellen in Wärme umwandelnde Bremse betätigt werden.The signal of the force measuring elements can be evaluated differently depending on the demands placed on the ease of use of the hand tool. For example, it is sufficient for certain applications to emit an optical or acoustic signal when a certain value is exceeded. The signal from the force measuring elements is preferably used to generate control functions of the hand tool. In this case, for example, a clutch interrupting the torque transmission or a brake converting the still existing rotational energy of the transmission shafts into heat can be actuated.

Die Erfindung soll nachstehend anhand einer sie beispielsweise wiedergebenden Zeichnung näher erläutert werden. Es zeigen:

  • Fig. 1 ein erfindungsgemässes Handwerkzeug, teilweise aufgeschnitten dargestellt;
  • Fig. 2 einen Querschnitt durch das in Fig. 1 dargestellte Handwerkzeug entlang der Linie II-II, in vergrössertem Masstab.
The invention will be explained in more detail below with the aid of a drawing, for example. Show it:
  • 1 shows a hand tool according to the invention, partially cut away;
  • Fig. 2 shows a cross section through the hand tool shown in Fig. 1 along the line II-II, on an enlarged scale.

Das aus den Fig. 1 und 2 ersichtliche Handwerkzeug weist ein insgesamt mit 1 bezeichnetes Gehäuse auf, mit dem ein Handgriff 2 lösbar verbunden ist. Der Handgriff 2 weist einen Drücker 3 zum Ein- und Ausschalten des Handwerkzeuges sowie eine Zuleitung 4 zur elektrischen Stromversorgung des Handwerkzeuges auf. Im unteren Teil des Gehäuses 1 ist ein insgesamt mit 5 bezeichneter Motor angeordnet. Ein Motorritzel 5a steht mit einem Zahnrad 6 im Eingriff. Das Zahnrad 6 ist mit einer insgesamt mit 7 bezeichneten Kurbelwelle fest verbunden. Die Kurbelwelle 7 ist einerseits in einem Radiallager 8 und andererseits in einem Lagerschild 5b des Motorr 5 gelagert. Das Radiallager 8 ist in einem insgesamt mit 9 bezeichneten Lagerbock angeordnet, der mittels eines Ansatzes 9a in einer Bohrung la des Gehäuses schwenkbar gelagert ist. Die Kurbelwelle 7 ist mit einer Verzahnung 7a versehen, die mit einem Stirnrad 10 in Eingriff steht. Das Stirnrad 10 ist mit einer insgesamt mit 11 bezeichneten Ritzelwelle fest verbunden. Die Ritzelwelle 11 ist über ein Schrägkugellager 12 ebenfalls im Lagerbock 9 abgestützt. Da der Lagerbock 9 um die Achse der Kurbelwelle 7 schwenkbar gelagert ist, bleiben das Stirnrad 10 und die Verzahnung 7a bei einer allfälligen Schwenkbewegung des Lagerbockes 9 unverändert in Eingriff. Die Ritzelwelle 11 trägt ein Kegelritzel lla, das mit einem Kegelrad 13 in Eingriff steht. Das Kegelrad 13 ist mit einem Zylinder 14 drehfest verbunden und mittels eines Sicherungsringes 15 gegen axiales Verschieben gesichert. Der Zylinder 14 ist über das Kegelrad 13 mittels eines Nadellagers 16 im Gehäuse 1 gelagert. Im Zylinder 14 ist ein Erregerkolben 17 axial verschiebbar geführt. Der Erregerkolben 17 ist mittels eines Pleuels 18 mit einem Kurbelzapfen 7b der Kurbelwelle 7 verbunden und wird beim Drehen der Kurbelwelle 7 in eine hin- und hergehende Bewegung versetzt. Im Zylinder 14 ist ebenfalls ein Schlagkolben 19 axial verschiebbar geführt. Zwischen dem Erregerkolben 17 und dem Schlagkolben 19 befindet sich ein Luftpolster 20, das zur Uebertragung der Schlagenergie vom Erregerkolben 17 auf den Schlagkolben 19 dient. In einen Werkzeughalter 21 ist ein Bohrer 22 eingesetzt, der vom Schlagkolben 19 beaufschlagt wird. Die Uebertragung der Drehbewegung auf den Bohrer 22 erfolgt über den Zylinder 14.The hand tool shown in FIGS. 1 and 2 has a housing, generally designated 1, to which a handle 2 is detachably connected. The handle 2 has a push button 3 for switching the hand tool on and off and a feed line 4 for the electrical power supply of the hand tool. In the lower part of the housing 1, a motor, generally designated 5, is arranged. A motor pinion 5a meshes with a gear 6. The gearwheel 6 is firmly connected to a crankshaft, denoted overall by 7. The crankshaft 7 is mounted on the one hand in a radial bearing 8 and on the other hand in a bearing plate 5b of the motor 5. The radial bearing 8 is arranged in a bearing block, designated overall by 9, which is pivotably mounted in a bore la of the housing by means of an extension 9a. The crankshaft 7 is provided with a toothing 7a which is in engagement with a spur gear 10. The spur gear 10 is fixedly connected to a pinion shaft, designated overall by 11. The pinion shaft 11 is also supported in the bearing block 9 via an angular contact ball bearing 12. Since the bearing block 9 is pivotally mounted about the axis of the crankshaft 7, the spur gear 10 and the toothing 7a remain unchanged in engagement with any pivoting movement of the bearing block 9. The pinion shaft 11 carries a bevel pinion 11a which is in engagement with a bevel gear 13. The bevel gear 13 is non-rotatably connected to a cylinder 14 and secured against axial displacement by means of a locking ring 15. The cylinder 14 is mounted on the bevel gear 13 by means of a needle bearing 16 in the housing 1. In the cylinder 14, an excitation piston 17 is axially displaceably guided. The excitation piston 17 is connected by means of a connecting rod 18 to a crank pin 7b of the crankshaft 7 and is set in a reciprocating motion when the crankshaft 7 is rotated. A percussion piston 19 is also axially displaceably guided in the cylinder 14. Between the exciter piston 17 and the percussion piston 19 there is an air cushion 20 which is used for transmission the impact energy from the excitation piston 17 to the percussion piston 19 is used. In a tool holder 21, a drill 22 is inserted, which is acted upon by the percussion piston 19. The rotary movement is transmitted to the drill 22 via the cylinder 14.

Der in Fig. 2 dargestellte, vergrösserte Querschnitt zeigt den Ansatz 9a des Lagerbockes, der in der Bohrung la des Gehäuses 1 schwenkbar gelagert ist. Da die Kurbelwelle 7 koaxial im Lagerbock 9 gelagert ist, wird durch das Schwenken des Lagerbockes'9 die Lage des Radiallagers 8 nicht verändert. Der das Schrägkugellager 12 aufnehmende Teil des Lagerbockes 9 ist mit zwei einander gegenüberliegenden Stützflächen 9b versehen. In Ausnehmungen lb des Gehäuses 1 angeordnete Kraftmesselemente 23 werden durch die bei der Drehmomentübertragung von der Kurbelwelle 7 auf die Ritzelwelle 11 entstehenden Reaktionskräfte beansprucht. Das Signal der Kraftmesselemente 23 dient der Erzeugung von Steuerfunktionen des Handwerkzeuges und kann beispielsweise zum Abschalten der Energiezufuhr, zum Betätigen einer Kupplung oder Bremse und dgl verwendet werden. Die Kraftmesselemente 23 bestehen vorzugsweise aus Piezokeramik. Solche Elemente erzeugen bei Druckbeanspruchung eine elektrische Ladung, die in eine Spannung umgesetzt werden kann. Durch das Anordnen von zwei einander gegenüberliegenden Kraftmesselementen 23 können bei einer allfälligen Drehrichtungsumkehr des Motors 5 die auftretenden Kräfte in beiden Drehrichtungen erfasst werden.The enlarged cross section shown in FIG. 2 shows the projection 9a of the bearing block, which is pivotably mounted in the bore 1a of the housing 1. Since the crankshaft 7 is mounted coaxially in the bearing block 9, the position of the radial bearing 8 is not changed by the pivoting of the bearing block 9. The part of the bearing block 9 which receives the angular contact ball bearing 12 is provided with two opposing support surfaces 9b. Force measuring elements 23 arranged in recesses 1b of the housing 1 are stressed by the reaction forces arising during the torque transmission from the crankshaft 7 to the pinion shaft 11. The signal from the force measuring elements 23 is used to generate control functions of the hand tool and can be used, for example, to switch off the energy supply, to actuate a clutch or brake and the like. The force measuring elements 23 are preferably made of piezoceramic. Such elements generate an electrical charge when subjected to pressure, which can be converted into a voltage. By arranging two opposing force measuring elements 23, the forces occurring in both directions of rotation can be detected when the direction of rotation of the motor 5 is reversed.

Claims (5)

1. Motorisch betriebenes Handwerkzeug mit einem Gehäuse, einem darin angeordneten Motor, einer vom Motor in Drehung versetzten Antriebswelle und einem zwischen dem Motor und der Antriebswelle angeordneten Getriebe, dadurch gekennzeichnet,dass wenigstens eine Getriebewelle (11) in einem im Gehäuse (1) begrenzt beweglichen, in Richtung der durch die Drehmomentübertragung auftretenden Reaktionskräfte über elektrische Kraftmesselemente (23) am Gehäuse (1) abgestützten Lagerbock (9) gelagert ist.1. Motor-operated hand tool with a housing, a motor arranged therein, a drive shaft set in rotation by the motor and a transmission arranged between the motor and the drive shaft, characterized in that at least one transmission shaft (11) delimits one in the housing (1) movable bearing bracket (9) supported in the direction of the reaction forces occurring by the torque transmission via electrical force measuring elements (23) on the housing (1). 2. Werkzeug nach Anspruch 1, dadurch gekennzeichnet, dass der Lagerbock (9) um eine parallel zur Getriebewelle (11) verlaufende Schwenkachse drehbar gelagert ist.2. Tool according to claim 1, characterized in that the bearing block (9) is rotatably mounted about a pivot axis running parallel to the gear shaft (11). 3. Werkzeug nach Anspruch 2, dadurch gekennzeichnet, dass die Schwenkachse des Lagerbocks (9) koaxial zur Drehachse eines mit der Getriebewelle (11) in Eingriff stehenden Zahnrades (6) verläuft.3. Tool according to claim 2, characterized in that the pivot axis of the bearing block (9) extends coaxially to the axis of rotation of a gear wheel (6) which is in engagement with the gear shaft (11). 4. Werkzeug nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, dass die Kraftmesselemente (23) aus Piezokeramik bestehen.4. Tool according to one of claims 1 to 3, characterized in that the force measuring elements (23) consist of piezoceramic. 5. Werkzeug nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, dass das Signal der Kraftmesselemente (23) der Erzeugung von Steuerfunktionen des Handwerkzeuges dient.5. Tool according to one of claims 1 to 4, characterized in that the signal of the force measuring elements (23) is used to generate control functions of the hand tool.
EP85810591A 1985-03-29 1985-12-12 Motor-driven hand tool Expired - Lifetime EP0199883B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19853511437 DE3511437A1 (en) 1985-03-29 1985-03-29 MOTORIZED HAND TOOL
DE3511437 1985-03-29

Publications (3)

Publication Number Publication Date
EP0199883A2 true EP0199883A2 (en) 1986-11-05
EP0199883A3 EP0199883A3 (en) 1988-04-20
EP0199883B1 EP0199883B1 (en) 1990-08-08

Family

ID=6266683

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85810591A Expired - Lifetime EP0199883B1 (en) 1985-03-29 1985-12-12 Motor-driven hand tool

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Country Link
EP (1) EP0199883B1 (en)
JP (1) JPS61226278A (en)
DE (2) DE3511437A1 (en)

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FR2647978A1 (en) * 1989-05-31 1990-12-07 Peugeot Outillage Elect Electric machine with torque limitation, especially screwdriver and/or drill
WO1992018291A1 (en) * 1991-04-12 1992-10-29 Robert Bosch Gmbh Hand-held power tool with jamming-detection sensor
FR2767737A1 (en) * 1997-09-01 1999-03-05 Bosch Gmbh Robert POWER TOOL
DE10316844A1 (en) * 2003-04-11 2004-11-04 Hilti Ag Control of an electric hand machine tool
US7938194B2 (en) 2003-04-24 2011-05-10 Black & Decker Inc. Safety mechanism for a rotary hammer
DE102010041313A1 (en) * 2010-09-07 2012-03-08 Robert Bosch Gmbh Machine tool, in particular hand tool
US8316958B2 (en) 2006-07-13 2012-11-27 Black & Decker Inc. Control scheme for detecting and preventing torque conditions in a power tool
EP2669061A1 (en) * 2012-05-29 2013-12-04 Makita Corporation Power tool
USD703017S1 (en) 2011-01-07 2014-04-22 Black & Decker Inc. Screwdriver
US9199362B2 (en) 2010-01-07 2015-12-01 Black & Decker Inc. Power tool having rotary input control
US9266178B2 (en) 2010-01-07 2016-02-23 Black & Decker Inc. Power tool having rotary input control
US9475180B2 (en) 2010-01-07 2016-10-25 Black & Decker Inc. Power tool having rotary input control
US10589413B2 (en) 2016-06-20 2020-03-17 Black & Decker Inc. Power tool with anti-kickback control system
US11697200B2 (en) 2017-07-24 2023-07-11 Festool Gmbh Power tool and method

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DE3707051A1 (en) * 1987-03-05 1988-09-15 Bosch Gmbh Robert Method for interrupting the drive activity, in particular at least the percussive-drive activity, of a powered hand tool
EP0303651B2 (en) * 1987-03-05 1999-12-01 Robert Bosch Gmbh Process for interrupting the operation of a hand tool, in particular percussion and/or rotation thereof
DE3707052A1 (en) * 1987-03-05 1988-09-15 Bosch Gmbh Robert Method for interrupting the drive activity, in particular rotary-drive activity, of a powered hand tool
DE10348397A1 (en) * 2003-10-17 2005-05-19 Robert Bosch Gmbh Schlagwerk for a hand tool
US7552781B2 (en) 2004-10-20 2009-06-30 Black & Decker Inc. Power tool anti-kickback system with rotational rate sensor
EP2163355A1 (en) 2008-09-12 2010-03-17 AEG Electric Tools GmbH Electric tool comprising an oscillating drive or crank drive with reduced mass
JP5534783B2 (en) 2009-11-10 2014-07-02 株式会社マキタ Electric tool
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WO1992018291A1 (en) * 1991-04-12 1992-10-29 Robert Bosch Gmbh Hand-held power tool with jamming-detection sensor
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US7938194B2 (en) 2003-04-24 2011-05-10 Black & Decker Inc. Safety mechanism for a rotary hammer
US8555997B2 (en) 2003-04-24 2013-10-15 Black & Decker Inc. Safety mechanism for a rotary hammer
US8316958B2 (en) 2006-07-13 2012-11-27 Black & Decker Inc. Control scheme for detecting and preventing torque conditions in a power tool
US9475180B2 (en) 2010-01-07 2016-10-25 Black & Decker Inc. Power tool having rotary input control
US9321156B2 (en) 2010-01-07 2016-04-26 Black & Decker Inc. Power tool having rotary input control
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US9211636B2 (en) 2010-01-07 2015-12-15 Black & Decker Inc. Power tool having rotary input control
US9266178B2 (en) 2010-01-07 2016-02-23 Black & Decker Inc. Power tool having rotary input control
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CN102398254A (en) * 2010-09-07 2012-04-04 罗伯特·博世有限公司 Machine Tool, Particularly Handheld Machine Tool
DE102010041313A1 (en) * 2010-09-07 2012-03-08 Robert Bosch Gmbh Machine tool, in particular hand tool
DE102010041313B4 (en) 2010-09-07 2021-09-23 Robert Bosch Gmbh Machine tool, in particular hand machine tool
USD703017S1 (en) 2011-01-07 2014-04-22 Black & Decker Inc. Screwdriver
US9505097B2 (en) 2012-05-29 2016-11-29 Makita Corporation Power tool
EP2669061A1 (en) * 2012-05-29 2013-12-04 Makita Corporation Power tool
US10589413B2 (en) 2016-06-20 2020-03-17 Black & Decker Inc. Power tool with anti-kickback control system
US11192232B2 (en) 2016-06-20 2021-12-07 Black & Decker Inc. Power tool with anti-kickback control system
US11697200B2 (en) 2017-07-24 2023-07-11 Festool Gmbh Power tool and method

Also Published As

Publication number Publication date
DE3511437A1 (en) 1986-10-02
EP0199883B1 (en) 1990-08-08
EP0199883A3 (en) 1988-04-20
DE3579160D1 (en) 1990-09-13
JPS61226278A (en) 1986-10-08

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