EP2861383A1

EP2861383A1 - Hand-held machine tool

Info

Publication number: EP2861383A1
Application number: EP13725956.0A
Authority: EP
Inventors: Helmut Burger; Thomas Thanner; Rene Richter
Original assignee: Hilti AG
Current assignee: Hilti AG
Priority date: 2012-06-13
Filing date: 2013-05-29
Publication date: 2015-04-22
Anticipated expiration: 2033-05-29
Also published as: WO2013186045A1; EP2861383B1; CN104507644B; DE102012209919A1; CN104507644A; JP6236072B2; US9905966B2; US20150132988A1; JP2015519213A

Abstract

A hand-held machine tool has an integrated tool or a tool holder (2) to receive a tool. An electric motor (5) drives the tool or the tool holder (2). A battery pack (18) for supplying power to the electric motor can be pushed into a guide (23) in a first direction. Electrical contacts are disposed in a contact holder (36) being offset with respect to each other in a second direction (26). A mounting (47) for the contact holder (36) holds the contact holder (36) so that it can move in the first direction (25) and in a third direction with respect to the mounting (47). The first direction (25), second direction (26) and third direction (28) are orthogonal to each other in pairs. A spring acts upon the contact holder with a force opposite to the first direction (25). An end face (38) oriented opposite to the first direction (25) is provided with a centring means (59) which cooperates with a centring support (60) on the battery pack (18) in order to prevent a relative movement between the end face (38) and the battery pack (18) in the third direction (28).

Description

Hand tool

FIELD OF THE INVENTION

The present invention relates to a hand-held machine tool, e.g. a hammer drill, a saw, a nailing tool. A supply of electrical consumers of the hand-held machine tool, in particular an electric motor is carried out by a battery pack. The battery pack is removable from the power tool. The battery pack can then be used in a charger for charging or replaced by a built-in charged battery pack.

A hammer drill produces strong vibrations, which require a holder and the electrical contacts of the battery pack. The electrical contacts are not only subject to mechanical wear but also due to arcs, which arise when opening and closing the contacts.

DISCLOSURE OF THE INVENTION The portable power tool according to the invention has an integrated tool or tool holder for receiving a tool. An electric motor drives the tool or the tool holder. In a guide along a first direction, a battery pack for powering the electric motor can be inserted. In a contact holder electrical contacts are arranged along a second direction, transversely to the first direction offset from one another. The electrical contacts are preferably arranged with play in the contact holder. A suspension for the contact holder keeps the contact holder movable along the first direction and along a third direction relative to the suspension. The first direction, second direction and third direction are orthogonal to each other in pairs. A spring urges the contact holder against the first direction with a force. An opposite to the first direction facing end face is provided with a centering, which cooperates with a centering support on the battery pack to prevent relative movement between the end face and the battery pack along the third direction. The contact holder is movably mounted on the hand tool in at least two directions. The suspension of the contact holder is constructed such that the movement along the first direction and the third direction is preferably limited to a first path or a second path.

The battery pack inserted in the hand tool machine electrically couples to the electrical contacts and mechanically to the contact holder. First, the battery pack moves the contact holder against the spring, whereby a positive connection is achieved. Furthermore, there is a positive connection of the centering on the contact holder with the centering support on the battery pack. The centering locally holds the end face opposite the battery pack in a fixed position along the third direction.

An embodiment provides that the centering has a mandrel which projects in the first direction and has a surface which is inclined with respect to the third direction and / or a recess which is recessed against the first direction and has a surface which is inclined with respect to the third direction. The inclined surface effect secure centering as compared to a blunt or non-sloped surface. The inclination of the surfaces with respect to the third direction is preferably greater than 30 degrees. For example, the mandrel has an isosceles triangle-shaped tip in cross-section parallel to the first and third directions.

An embodiment provides that the contact holder is pressed against the mandrel and / or the notch on the battery pack and the end face is otherwise spaced from the battery pack. The spacing of the non-sloped faces of the face avoids interference with centering by these non-sloped faces.

An embodiment provides that the contacts are mutually movably arranged in the contact holder. The contacts are preferably with play in the contact holder. Locally occurring vibrations on a contact can be kept away from other contacts.

The contacts may be formed as sockets for receiving sword-shaped contacts of the battery pack. For example, the sockets are slotted along the third direction. The mating contacts are preferably sword-shaped and oriented parallel to the third direction. An embodiment provides that at least one of the contacts is electrically contacted via a Zopflitze.

An embodiment provides that the contact holder is exposed in the first direction. The contact holder is connected in the first direction only non-positively via the spring to the power tool.

BRIEF DESCRIPTION OF THE FIGURES The following description explains the invention with reference to exemplary embodiments and figures. In the figures show:

1 shows a hammer drill Fig. 2 shows a cross section through the hammer drill in the plane II-II

Fig. 3 shows a cross section through the hammer drill in the plane III-III

Fig. 4 is a partial section through a suspension

Fig. 5 is a plan view of a contact holder

Fig. 6 shows a cross section through the hammer drill in the plane V-V Fig. 7 a hammer drill

Fig. 8 shows a cross section through the hammer drill in the plane VII-VII

Identical or functionally identical elements are indicated by the same reference numerals in the figures, unless stated otherwise.

EMBODIMENTS OF THE INVENTION

As an example of a hand-held power tool, FIG. 1 schematically shows a hammer drill 1. The hammer drill 1 has a tool holder 2, into which a shank end 3 of a tool, for example one of the drill bit 4, can be inserted. A primary drive of the hammer drill 1 forms an electric motor 5, which a striking mechanism 6 and a Output shaft 7 drives. A user can perform the hammer drill 1 by means of a handle 8 and take the hammer drill 1 by means of a system switch 9 in operation. In operation, the hammer drill 1 rotates the drill bit 4 continuously about a working axis 10 and can beat the drill bit 4 in the direction of impact 11 along the working axis 10 in a substrate.

The percussion 6 is, for example, a pneumatic percussion 6. A pathogen 12 and a racket 13 are guided in the percussion 6 along the working axis 10 movable. The exciter 12 is coupled via an eccentric 14 or a wobble finger to the motor 5 and forced to a periodic, linear movement. An air spring formed by a pneumatic chamber 15 between exciter 12 and racket 13 couples a movement of the racket 13 to the movement of the exciter 12 at. The racket 13 can strike directly on a rear end of the drill bit 4 or indirectly transfer part of its pulse to the drill bit 4 via a substantially resting intermediate racket 16. The striking mechanism 6 and preferably the further drive components are arranged within a machine housing 17.

The power supply of the electric motor 5 is effected by a battery pack 18. The battery pack 18 has a battery housing 19 which is separate from the hammer drill 1 and in which a plurality of battery cells 20 are arranged. The battery pack 18 can be inserted into a holder 21 of the hammer drill 1 and removed. The holder 21 is preferably formed on a substantially outer surface 22 of the machine housing 17 or the handle 8. The holder 21 has a guide 23 of, for example, two parallel grooves 24, which are oriented along an insertion direction 25 and offset from each other in a second (horizontal) direction 26 are (Fig. 2). The battery case 19 of the battery pack 18 is provided with two parallel rails 27 having an L-shaped profile. The battery housing 19 can be used with its rails 27 in the grooves 24 of the guide 23 and inserted along the predetermined direction of the guide 23 insertion direction 25. The guide 23 and the battery housing 19 engage behind each other mutually along a third (vertical) direction 28. The battery pack 18 is supported by the guide 23 in the direction orthogonal to the insertion direction 25 directions 26, 28 with little or no play.

The holder 21 is provided with recesses oriented perpendicular to the guide 23, in which locking pins 29 of the battery pack 18 can engage (FIG. 3). The locking pins 29 are preferably biased by springs and snap in as soon as the battery pack 18 is inserted into the holder 21 as far as a stop. The Locking pin 29 lock the battery pack 18 against movement along the direction of insertion 25. The user can take the locking pin 29 by pressing a push button 30 out of engagement with the holder 21 to pull the battery pack 18 from the holder 21 against the insertion direction 25 can. The structure of the guide 23 is only an example, in particular, the holder 21 may be provided with the locking pin 29 and / or the bracket 21 with rails 27 of an L-shaped profile.

The holder 21 is provided with electrical contacts 31 which contact electrical mating contacts 32 of the battery pack 18. The contact is made when the battery pack 18 is locked in the guide 23. The contacts 31 preferably lie next to one another along the second direction 26 and otherwise preferably at the same height, in particular along the third direction 28. Expediently, two current-carrying contacts 33 and two or more signal-carrying contacts 34 are provided. The current-carrying contacts 33 are designed for more than 10 amps to power the hammer drill 1. The contacts 31 are made entirely of metal, given the mechanical stresses in a hammer drill 1 of an iron-containing alloy, preferably with a high copper content. The signal-carrying contacts 34 are designed for a lower load, since only currents of less than 10 mA flow through them.

The electrical contacts 31 of the hammer drill 1 are slotted sockets. The opposite jaws 35 of the contact 31 may be resilient. Preferably, when inserting the electrical mating contacts 32 of the battery pack 18 between the jaws 35, these resilient jaws 35 are pushed apart and thus clamped to the mating contacts 32. The electrical contacts 32 of the battery pack 18 may be formed as swords. The slots or swords preferably run parallel to the vertical, third direction 28.

The electrical contacts 31 are inserted into an electrically insulating contact holder 36 (FIG. 5). The contacts 31 are adjacent to each other and are spaced apart in the second direction 26. The contact holder 36 has for each of the electrical contacts 31, in particular the current-carrying contacts 33, a separate receiving space 37. The electrical contact 31 can move in the receiving space 37 along the insertion direction 25, the game is for example in the range of 0, 1 mm up to 0.3 mm. The electrical contacts 31 may spring-projecting in the second direction 26 Have wings with which the electrical contacts 31 are supported on the side walls of the receiving spaces 37. The contacts 31 are due to their movable arrangement within the contact holder 36 to each other movable. The receiving spaces 37 are open at a direction opposite to the insertion direction 25 facing front end face 38. The mating contacts 32 of the battery pack 18 can be inserted through the opening 39 into the receiving spaces 37 and to the electrical contacts 31 arranged therein.

At each of the contacts 31, a strand 40 is crimped or clamped or clamped to the electrical contact 32 (Figure 5). The strands 40 are guided in the contact holder 36 in each case a channel 41. In the illustrated embodiment, a clamping bar 42 is provided in the contact holder 36. The strands 40 are attached at one end to one of the contacts 31 and its other end in the terminal block 42. The terminal strip 42 mechanically decouples the strands 40 from the wiring within the hammer drill 1. In this way, in particular, a transmission of torsional forces of the lines partially twisted when laying on the strands 40 is prevented. The Torisionskräfte could otherwise lead to a jamming of the contacts 32 on side walls of the receiving spaces 37. The strands 40 are composed of braided wires. The plaited braids 40 are preferably for at least 2 cm inside the contact holder 36 without insulating plastic jacket. The braid can be deformed by the introduced torsional forces and thus decouples these from the contacts 31. With a shrink tubing insulated strands or strands with twisted wires prove to be unfavorable, even strands with very fine wires. The clamping strip 42 is arranged, for example, on the end face 38 remote from the end of the contact holder 36. The terminal block 42 may be provided with electromechanical coupling pieces 43. The coupling piece 43 connects the strand 40 with another cable 44, which is guided in the machine housing 17. The coupling piece 43 is formed, for example, as a luster terminal with two screws 45 for fixing the stranded wire 40 and the cable 44. The coupling pieces 43 are immovably inserted in the contact holder 36. The clamping strip 42 may alternatively or in addition to the coupling pieces 43 in the channel 41 have a constriction 46 in which the strand 40 is crimped. The contact holder 36 is suspended from the machine housing 17 movable. A suspension 47 of the contact holder 36 allows limited movement of the contact holder 36 along the direction of insertion 25. The suspension 47 can do so For example, have longitudinal grooves 48 in the machine housing 17, in which guide rails 49 engage the contact holder 36 (Fig. 4). Stops 50, 53 on both sides of the contact holder 36 limit the movement to a distance 51, 54 of a total of, for example, 2 mm to 5 mm. One or more springs 52, such as coil springs, act on the contact holder 36 against the insertion direction 25. If the battery pack 18 is not used, press the springs 52, the contact holder 36 to the front in the insertion direction 25 stop 50. The springs 52 are inserted under bias. When inserting the battery pack 18 of the contact holder 36 is taken from the battery pack 18 against the force of the springs 52 in the insertion direction 25. The distance 51, 54 is dimensioned such that when the lock 29 locks the battery pack 18, the contact holder 36 is still spaced from the rear stop 53 in the insertion direction 53 by a part 54 of the path 51, 54.

The contact holder 36 may also move slightly in the suspension 47 along the second direction 26, as opposed to the battery pack 18 in the holder 21. The clearance for the movement is preferably at least 1 mm in the second direction 26. The distance between the opposite longitudinal grooves 48 is greater by the free space than the width of the contact holder 36 in the region of the guide rails 49. Further, the contact holder 36 can move along the third direction 28 freely between vertical stops. The free distance 55 between the stops is in the range of 0.5 mm to 2 mm. The vertical stops are formed for example by groove walls of the longitudinal grooves 48, the distance to the distance 55 is greater than the dimension guide rails 49 along the vertical direction 28.

The movable contact holder 36 may be alternatively or additionally suspended in a fixed to the handle 8 or machine housing 17 Bock 56. The bracket 56 is arranged in the insertion direction 25 behind the contact holder 36. The contact holder 36 has one or more projecting in the direction of insertion 25 pins 57, which are inserted into sockets 58 of the trestle 56. The sockets 58 are wider and higher than the pins 57 to ensure the mobility of the contact holder 36 in the second direction 26 and third direction 28. The springs 52 may be mounted in the bracket 56 and be supported on the bracket 56. The bracket 56 forms the rear stop 53. The strands 40 or cable 44 may be guided in the block 56 substantially parallel to the insertion direction 25.

The contact holder 36 is provided with a vertical centering 59 on the front end 38. The vertical, ie along the third direction 28, acting centering 59 engages in a complementary centering support 60 on the battery pack 18 a. The springs 52 press the centering 59 in the centering support 60 and positively and positively fix the relative vertical position of the front end face 38 relative to the battery pack 18. The front end face 38 and the holder 21 continue to remain movable relative to the machine housing 17 and the hammer drill 1 , The front end face 38 can move relative to the machine housing 17 about the free path 55 along the vertical third direction 28. The centering 59 is dimensioned along the direction of insertion 25 such that only the centering 59 rests against the battery pack 18. The remaining areas of the contact holder 36 are spaced along the insertion direction 25. The contacts 31, 32 touch each other or are inserted into each other.

The centering 59 shown as an example is realized by means of projecting from the end face 38 thorns 59. The mandrels 59 are wedge-shaped, pyramidal or conical. A machine housing 17 facing upper surface 61 of the mandrel 59 is inclined relative to the third direction 28. The upper surface 61 moves away from the machine housing 17 counter to the insertion direction 25 along the third direction 28. A lower surface 62 facing away from the machine housing 17 may alternatively or in addition to the upper surface 61 be inclined relative to the third direction 28. The lower surface 62 rises against the insertion direction 25 along the third direction 28 to the machine housing 17 at. The mandrels 59 are preferably arranged along the second direction 26 between the contacts 32. In the preferred example, the mandrels 59 directly adjoin the receiving spaces 37 of the current-carrying contacts 33.

The battery pack 18 has a contact carrier 63, which is preferably immovably connected to the battery housing 19. The contact carrier 63 is made of an electrically insulating material, for example. A plastic. In the plastic, the mating contacts 32 are immovably embedded. The mating contacts 32 are preferably designed as swords lying in planes parallel to the insertion direction 25 and the third direction 28. The centering support 60 is arranged, for example, between the mating contacts 32. The pointing in the insertion direction 25 end face 64 of the centering support 60 is provided with a notch, which is formed in the form complementary to the mandrel 59. The notch is preferably prismatic, i. the cross section of the notch is constant along the second direction 26. The centering 59 thus acts only in the third direction 28 and has no influence on a movement along the second direction 26.

The arrangement of the centering 59 and the centering support 60 immediately adjacent to the current-carrying contacts 33 and mating contacts 32 proves to be stiff even Materials for the contact holder 36 and the contact carrier 63 as advantageous to sufficiently suppress a relative movement along the third direction 28 between the current-carrying contacts 33 and mating contacts 32. The centering 59 on the end face 38 of the contact holder 36 may be formed as a notch and the centering support as a mandrel. Furthermore, the centering can have both notches and pins, wherein the centering supports are designed to be complementary.

The strand 40 can be inserted into the channel 41 in a wave form (FIGS. 7, 8). The channel 41 has at least a 50% larger dimension in the second direction 26 compared to the cross section of the strand 40. The strand 40 extends between the terminal block 42 and the contacts 31. However, the length of the strand 40 is at least 10% greater than the distance from terminal strip 42 and the contacts 31. The strands 40 change along the direction of insertion 25 several times their course relative to the second direction 26 or the third direction 28. This was an effective damping of movements in the submillimeter range of the contacts can be achieved. The wires of the strand 40 may be braided into a braid.

The hammer drill 1 is, in addition to a chisel hammer, a nail and bolt setting tool and a reciprocating saw, an example of a battery powered electric power tool that is subjected to strong vibration during operation and may be provided with the movable contact holder 36. The setting tool generated by the striking as a tool on the nails firing pin shocks that can lead to a relative movement of battery pack and machine housing. For saws, especially reciprocating saws, the vibrations are generated by the saw blade and transferred to the machine tool.

Claims

PATENT CLAIMS

Hand tool with

an integrated tool or a tool holder (2) for holding a tool,

an electric motor (5) for driving the tool or the tool holder (2), a guide (23) into which a battery pack (18) can be inserted along a first direction to supply power to the electric motor,

a contact holder (36) in which electrical contacts (31) are arranged offset from one another along a second direction (26),

a suspension (47) for the contact holder (36), the contact holder (36) being movable along the first direction (25) and along a third direction (28) relative to the suspension (47), the first direction (25), second direction (26) and third direction (28) are orthogonal to one another in pairs,

a spring (52) which applies force to the contact holder (36) counter to the first direction (25),

wherein an end face (38) pointing counter to the first direction (25) is provided with a centering (59) which cooperates with a centering support (60) on the battery pack (18) in order to ensure a relative movement along the third direction (28) between the Front side (38) and the battery pack (18) to prevent.

Hand tool according to claim 1, characterized in that the centering (59) has a mandrel (59) projecting in the first direction with a surface inclined relative to the third direction and / or a notch set back against the first direction with a surface inclined relative to the third direction having.

Hand tool according to claim 2, characterized in that the contact holder (36) is pressed against the battery pack with the mandrel (59) and/or the notch and the end face (38) is otherwise spaced from the battery pack.

Hand tool according to one of the preceding claims, characterized in that the contact holder (36) is movable along the first direction (25) for a distance (51) between 2 mm and 5 mm.

5. Hand tool according to one of the preceding claims, characterized in that the contact holder (36) is movable along the third direction (28) for a distance (51) between 0.5 mm and 2 mm.

6. Hand tool according to one of the preceding claims, characterized in that the contacts (31) are arranged with play along the first direction (25) in the contact holder (36).

7. Hand tool according to one of the preceding claims, characterized in that the contact holder (36) has a terminal strip (42), and one end of a stranded wire (40) in the terminal strip (42) and another end of the stranded wire (40). one of the contacts (31) are attached.

8. Hand tool according to one of the preceding claims, characterized in that at least one of the contacts is electrically contacted via a pigtail wire.

9. Hand tool according to one of the preceding claims, characterized in that the contact holder (36) is exposed in the first direction (28).

10. Hand tool according to claim 9, characterized in that the contact holder (36) is only non-positively connected to the hand tool in the first direction (28) via the spring (52) when the battery pack (18) locks in the guide (23). is.