Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D16/00—Portable percussive machines with superimposed rotation, the rotational movement of the output shaft of a motor being modified to generate axial impacts on the tool bit
  • B25D16/006—Mode changers; Mechanisms connected thereto
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D2216/00—Details of portable percussive machines with superimposed rotation, the rotational movement of the output shaft of a motor being modified to generate axial impacts on the tool bit
  • B25D2216/0007—Details of percussion or rotation modes
  • B25D2216/0015—Tools having a percussion-only mode
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D2216/00—Details of portable percussive machines with superimposed rotation, the rotational movement of the output shaft of a motor being modified to generate axial impacts on the tool bit
  • B25D2216/0007—Details of percussion or rotation modes
  • B25D2216/0023—Tools having a percussion-and-rotation mode
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D2216/00—Details of portable percussive machines with superimposed rotation, the rotational movement of the output shaft of a motor being modified to generate axial impacts on the tool bit
  • B25D2216/0007—Details of percussion or rotation modes
  • B25D2216/0038—Tools having a rotation-only mode
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D2216/00—Details of portable percussive machines with superimposed rotation, the rotational movement of the output shaft of a motor being modified to generate axial impacts on the tool bit
  • B25D2216/0007—Details of percussion or rotation modes
  • B25D2216/0046—Preventing rotation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
  • B25D—PERCUSSIVE TOOLS
  • B25D2250/00—General details of portable percussive tools; Components used in portable percussive tools
  • B25D2250/065—Details regarding assembling of the tool

Definitions

• the invention relates to a structural unit for a power tool according to the preamble of patent claim 1 and to a power tool equipped with such a structural unit according to patent claim 10.
• a rotary hammer with chisel function is known in which different operating modes are switchable by means of a slide switch.
• the chisel function is realized in that a driven gear rotatably fixed to the drill spindle is pushed axially into a locking position with a housing-fixed locking ver ⁇ .
• a rotary hammer in which the different operating modes are switchable by means of a rotary switch, wherein the rotational movement of the rotary switch is converted via a switching plate in an axial movement.
• the switching plate is mounted displaceably in the housing and is moved over an eccentrically arranged on the rotary switch cams be ⁇ .
• a locking plate fastened to the gear housing is provided, the toothed area of which, by engagement with the teeth of the driven gearwheel of the drill spindle, holds it against rotation. In a "Zahn ⁇ on-tooth position" between locking plate and Abtriebs ⁇ gear, the latter can not be moved into the locking position.
• the invention has for its object to propose a structural unit for a power tool, is ensured by the simple assembly of the power tool.
• the object underlying the invention is to propose a power tool, in particular electric hand tool such as hammer drill with chisel function, which is ein ⁇ fold to assemble.
• the invention is based on the idea of creating a preassemblable unit in the form of a synchronization and switching unit for a rotary knob for switching different operating modes, which on the one hand has a locking element with which a part rotating with the tool spindle, in particular the output gear, on the other hand with a switching plate with switching curve for converting a rotational movement of the rotary switch is provided in an axial movement to the circuit of different operating modes for the realization of a chisel.
• eccentric cams are arranged on the rotary switch with respect to the axis of rotation of the rotary switch, which cooperate with the Weg ⁇ curves of the shifters.
• the locking element for the perception of the drill spindle lock in the chisel function is to be designed such that it meshes with a larger number of gear gaps of a driven gear on the drill spindle, for example over a quarter circle or a Eighth circle to secure the chisel position wear-free.
• the assembly has two, preferably parallel to each other an ⁇ ordered, axially displaceable button, wherein a switching plate for connecting and disconnecting the percussion drive and a switching plate for the axial displacement of a Abretestechnikra ⁇ is formed on the tool spindle.
• the output gear is movable with this switching plate in an axial position in which it is not in engagement with the drive gear of the countershaft and on the other hand is not yet locked by means of the locking element.
• bit position search position the desired angle of rotation of the bit can be selected, in which the output gear is to be blocked in a further switching position.
• the unit comprises a guide rod, along which the locking element and at least one switching plate against each spring force are axially displaceable. Due to the fact that the locking element is not fixed in its position, but rather is arranged axially displaceable against a spring force, a synchronization device between output gear and locking element is created in a surprisingly simple and effective manner. In the event that during the axial movement of the locking element along the boring spindle into the locking position the teeth of the locking element should be aligned with the teeth of the drive gear, the locking element is displaced axially against the spring force.
• the installation of the assembly in a power tool can be done simply by the guide rod is taken with its two end in a respective bearing in the housing, in particular is locked.
• the axial Federkraftbeetzschlagung at least one control panel also provides a synchronization device. If the output gear wheel can not be brought into engagement with the drive gear of a countershaft because of its angular position, the rotary switch can still be rotated into the corresponding position due to the design according to the invention. As soon as the rotary drive is switched on, the output gear wheel, due to the axial spring load, snaps into meshing engagement with the drive gear of the countershaft. In the same way, the connection and disconnection mechanism for the percussion drive can be synchronized if the switching plate provided for the circuit of the percussion drive is designed to be axially spring-loaded.
• the shifters are forcibly guided only in one direction of movement, so that switching through the rotary knob is possible independently of the angular position of the toothed wheels or coupling elements relative to one another.
• the switching plate which moves the output gear axially, should be loaded in such a manner that the driven gear is spring-loaded in the direction of the drive gear, so that the switching plate is positively driven out of the rotational drive position.
• the switching plate which is responsible for the connection and disconnection of the percussion drive. Also, this switching plate should be forced out only from the engaged position.
• the locking element and at least one switching plate in each case a coaxially arranged Weg ⁇ rod spring, preferably coil spring, is assigned, each coil spring arranged with one end to one on the shift rod Stop, in particular a Si cherungsring supported. It is advantageous if the An ⁇ impact for a switching plate associated coil spring simultaneously forms an axial stop for the locking element and / or the stop for a switching plate associated coil spring simultaneously forms an axial stop for another switching plate.
• the locking teeth are arranged symmetrically with respect to a central axis which is perpendicular to a longitudinal axis of the guide rod. This ensures that the locking element is acted upon symmetrically with respect to the guide rod and can not be twisted or folded against it.
• a headband may be provided, which in the
• a particularly resilient and low-wear locking element according to the invention is obtained when the Arretierele ⁇ element by means of the metal injection molding method (MIM) is made.
• MIM metal injection molding method
• metal powder is first mixed with plastic powder and injected into a mold, whereupon the plastic is baked.
• FIG 3 is a perspective view of the front sectionbe ⁇ empire of a hammer drill in the switch position "drilling with impact drive” (drill hammers),
• FIG. 4 is a perspective view of the front Operabe ⁇ empire of a hammer drill in the switch position "drilling without percussion drive",
• 5 is a perspective view of the front sectionbe ⁇ empire of a hammer drill in the switch position "chiselling" with locked drilling spindle
• 6 is a perspective view of the front sectionbe ⁇ empire of a hammer drill in the switch position "chiselling" at a "tooth-on-tooth position”zwi ⁇ 's output gear and locking element
• FIG. 7 is a perspective view of the front Operabe ⁇ empire of a hammer drill in the switch position "chisel position search" and
• the structural unit 1 consists of a guide rod 2 on which a locking element 3 with locking teeth 4, as well as a first switching plate 5 and a second switching plate 6 are mounted axially displaceably.
• the guide rod 2 is guided for this purpose by an integrally formed with the locking element 3 bearing sleeve 7.
• the shifters 5, 6 are arranged parallel to each other and in each case via orthogonal to the shrouds 5, 6 aligned th tabs 8, 9, 10, 11 held captive and displaceable on the guide rod 2, wherein the guide rod 2 through a respective through hole in the tabs 8, 9, 10, 11 is guided.
• the second switching plate 6 is arranged between the first Weg ⁇ plate 5 and a rotary knob 12, wherein the second switching plate is provided with a 90 ° angled and parallel to the guide rod 2 extending connecting plate 13 which engages over the first switching plate 5 and the second
• Switch plate 6 with the tabs 10, 11 connects.
• the tab 10 of the second th shift plate 6 between the tabs 8, 9 of the first shift plate on the guide rod 2 is arranged.
• Each switching plate 5, ⁇ has a guide curve 14, 15, which cooperate with a respective transverse to the guide rod 2 extending cam 16, 17 of the rotary switch 12.
• the first shift plate 5 is displaced against the spring force of a coil spring 18 on the guide rod 2 in the direction of locking element 3.
• the cam 17 is in the switch position shown not engaged with the associated guide cam 15.
• the shrouds 5, 6 are zwangsge ⁇ leads only in one axial direction.
• the locking teeth 4 of the locking element 3 are arranged over a circular segment.
• the locking element 3 rests against a retaining ring 19, which is held in a groove of the guide rod 2 and forms an axial stop for the locking element 3.
• the securing ring 19 simultaneously forms a stop for the spiral spring 18 of the first switching plate 5, as a result of which the spiral spring 18 is supported on the securing ring 19 and on the lug 8.
• the locking element 3 is associated with a coaxial with the guide rod 2 and the bearing sleeve 7 arranged coil spring 20 which is supported at one end to a held in a circumferential groove of the guide rod 2 retaining ring 21 and with its other end laterally on the locking element 3.
• the locking element 3 two axially and parallel to the guide rod 2 extending Bolt 22, 23 provided, which can engage in corresponding recesses in the housing.
• the second switching plate 6 is associated with a coil spring 24 which, like all coil springs 18, 20 coaxial with the guide rod 2 is arranged.
• the spiral spring 24 is supported on a circlip 25 held in a groove of the guide rod 2 and laterally on the lug 10 of the second switch plate 6.
• the securing ring 25 simultaneously forms an axial stop for the first switching plate 5.
• the axial stop for the second switching plate 6 is formed by a securing ring 26.
• FIGS. 3 to 7 only the partial area of a rotary hammer is shown in fragmentary form.
• the unillustrated drive motor is in a fixed rotary engagement with a countershaft 27 via a shaft 28, wherein the countershaft 27 causes both the rotary drive for the drill spindle 29 and the impact drive.
• the percussion drive is realized by means of a Taumella ⁇ designed in a conventional manner 30, which acts via a wobble finger on a Kol ⁇ ben a striking mechanism.
• the countershaft 27 is guided centrally through the swash bearing 30 and mounted rotatably with respect to this.
• the swash bearing 30 can be brought via a jaw clutch 31 in rotationally fixed engagement with the Vorgele ⁇ waves 27, as shown for example in Fig. 3.
• the dog clutch 31 has an axially displaceable on the countershaft 27 and rotationally fixed on this mounted coupling sleeve 32 with two axially projecting
• Clutch cam 33 which can engage in corresponding grooves of a Kupp ⁇ lungsussi speakings 35.
• the coupling piece 35 is rotatably connected to the swash bearing 30.
• the second switching plate 6 engages with the tab 10 in a um ⁇ running groove 36 of the coupling sleeve 32, whereby the second switching plate 6 and the coupling sleeve 32 of the dog clutch 31 can perform a coupled axial movement.
• a drive gear 37 is arranged rotatably, which meshes in Fig. 3 with a driven gear 38.
• the output gear 38 is rotatably mounted on the drill spindle 29.
• a slip clutch 39 is provided in a known manner in order to avoid injuries when tilting the drill during the drilling operation.
• the slip clutch and thus the output gear 38 and the first shift plate 5 are coupled together in the axial direction.
• the first switching plate 5 engages with the tab 8 in a circumferential groove 40 of the slip clutch 39, so that the output gear 38 is indeed rotatable relative to the unit 1, but in the axial direction of movement is positively connected to the first switching plate.
• the operating mode "drilling with impact drive” (rotary hammers) is shown in Fig. 3.
• the shifters 5, 6 abut with the tabs 8, 11 on the securing rings 25, 26, whereby the output gear 38 of the drill spindle 29 meshes with the drive gear 37 of the countershaft 27, which in turn transmits the rotary motion of the drive gear 37 via the output gear 38 to the drill spindle 29 (drilling).
• the dog clutch 31 is closed.
• the coupling sleeve 32 engages with the coupling cam 33 in grooves of the Kupplungsge ⁇ gen administrats of the swash bearing 30, whereby the rotational movement of the countershaft 27 is transmitted to the swash bearing 30, wo ⁇ by again a wobble finger acts on a percussion piston, not shown (hammering).
• the rotary switch 12 is rotated into the switching position "bores", whereby the second switching plate 6 has been displaced axially against the spring force of the spring 24 on the guide bar 2 in the direction of the locking element 3, as compared to FIG. by the cam 17 having been moved along the guide curve 15.
• the coupling sleeve 32 forcibly coupled to the second shift plate has been displaced axially along the countershaft 27 in the direction of the drive gear 37, whereby the coupling cams 33 of the coupling sleeve 32 are disengaged from the grooves 36 of the coupling counterpart 35
• the axial position of the first shift plate 5 has not been changed compared to the operating mode shown in FIG. whereby the drive gear 37 continues to mesh with the output gear 38 of the drill spindle 29.
• Fig. 6 shows the same switch position as in Fig. 5.
• the output gear 38 could not be brought into engagement with the locking teeth 4 of the locking element 3, since the teeth of the output gear 38 and the locking teeth 4 were cursing in Fig.
• the rotary switch 12 is rotated into the "cutter position position.”
• the first shift plate 5 has been displaced axially, to such an extent that the driven gear 38 is positioned in the axial direction between the drive gear 37 and the arresting element 3
• the rotary drive is decoupled, however, the drill spindle 29 with the output gear 38 is manually rotatable so that the desired bit position can be searched before the rotary switch 12 is rotated by another 45 ° into the "bit position" shown in FIG "is twisted.
• FIG. 8 shows a retaining clip 41, which is fastened to a housing flange 46 with a fastening leg 42.
• the retaining bar 41 has a securing leg 44 which engages around the switching plate 5 in a front contact area 45. In this position, it is thus ensured that the slip coupling 39 is held positively in position via the groove 40 with the leg 8 of the switching plate 5. Without such Retaining clip 41, the slip clutch 39 is held only kraft ⁇ conclusively on the coil spring 18 on the locking ring 25, so that in the case of a shock stress there is the risk that the driven gear 38 disengages. An increase in the spring force to reduce this Ge ⁇ separates, otherwise the switching forces are too high.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Percussive Tools And Related Accessories (AREA)
• Drilling And Boring (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=35641946

Family Applications (1)

Country Status (5)

Cited By (2)

Families Citing this family (12)

Citations (7)

Family Cites Families (5)

• 2004
  • 2004-10-27 DE DE200410052329 patent/DE102004052329A1/de not_active Withdrawn
• 2005
  • 2005-10-27 EP EP05799747A patent/EP1814699B1/de not_active Not-in-force
  • 2005-10-27 CN CN2005800369937A patent/CN101111350B/zh not_active Expired - Fee Related
  • 2005-10-27 RU RU2007119551/02A patent/RU2360788C2/ru not_active IP Right Cessation
  • 2005-10-27 WO PCT/EP2005/011527 patent/WO2006045611A1/de active Application Filing

Patent Citations (8)

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