EP3865263A1 - Appareil de travail, en particulier appareil de travail portable guidé à la main - Google Patents

Appareil de travail, en particulier appareil de travail portable guidé à la main Download PDF

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Publication number
EP3865263A1
EP3865263A1 EP20157429.0A EP20157429A EP3865263A1 EP 3865263 A1 EP3865263 A1 EP 3865263A1 EP 20157429 A EP20157429 A EP 20157429A EP 3865263 A1 EP3865263 A1 EP 3865263A1
Authority
EP
European Patent Office
Prior art keywords
housing
brake drum
protective cover
wall
tool according
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.)
Withdrawn
Application number
EP20157429.0A
Other languages
German (de)
English (en)
Inventor
Jens Kreutzer
Frederik Herrmann
Helmut Schlessmann
Günter Wolf
Michael Zwergal
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Andreas Stihl AG and Co KG
Original Assignee
Andreas Stihl AG and Co KG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Andreas Stihl AG and Co KG filed Critical Andreas Stihl AG and Co KG
Priority to EP20157429.0A priority Critical patent/EP3865263A1/fr
Publication of EP3865263A1 publication Critical patent/EP3865263A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
    • B27B—SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR
    • B27B17/00—Chain saws; Equipment therefor
    • B27B17/08—Drives or gearings; Devices for swivelling or tilting the chain saw
    • B27B17/083—Devices for arresting movement of the saw chain

Definitions

  • the invention relates to a work device, in particular a hand-held work device, with a housing in which at least one drive motor with a drive element is arranged.
  • the drive element protrudes at least partially over a housing wall of the housing of the implement.
  • the drive element drives a tool of the implement.
  • a braking device is provided for the tool, the braking device comprising a brake drum which is drivingly connected to the drive element. When the braking device is active, the tool is braked to a standstill via the brake drum.
  • the brake drum lies in a housing opening in the housing wall of the housing, a gap being formed between the stationary housing wall and the rotating brake drum.
  • the housing wall separates the housing of the implement from an external dirt space in which the drive element for the tool rotates.
  • the tool is a motorized chain saw, for example, the drive pinion of the saw chain, which rotates on a guide rail, is located in the dirt space.
  • the guide rail is clamped to the housing of the implement by means of a sprocket cover.
  • the tool for example a saw chain
  • dirt particles will enter the housing of the implement through the gap between the stationary housing wall and the rotating brake drum. This can be too increased cleaning work during service and, under unfavorable circumstances, lead to premature failure of the drive unit.
  • the invention is based on the object of designing a work device, in particular a carried hand-held work device, in such a way that the entry of dirt particles from the dirt space via a gap between stationary housing parts and rotating drive elements is avoided.
  • a section of the brake drum that protrudes beyond the housing wall of the housing of the implement carries a protective cover which is at least partially outside the housing of the implement in front of the housing wall.
  • the protective cover is arranged in such a way that the protective cover covers the gap between the stationary housing wall of the housing and the rotating brake drum.
  • the design is provided in such a way that at least one area of the protective cover rotating with the brake drum forms a labyrinth seal with the stationary housing wall of the housing.
  • a labyrinth seal or gap seal achieves a seal between a stationary and a rotating component by constructively extending the flow path.
  • This structural design ensures that no dirt particles from the dirt space can enter the gap between the stationary housing wall and the rotating brake drum. Contamination in the housing of the implement is prevented. Malfunctions caused by soiling can largely be avoided.
  • the gap to be sealed by the protective cover between the rotating brake drum and the housing wall is open to a dirt space of the implement.
  • the protective cover provided for sealing the gap is expediently in the Dirt area of the implement.
  • the protective cover covers the gap directly, with only a small distance from the gap.
  • the distance between the protective cover and the gap is in the range from 0.2 mm to 15 mm, in particular 0.5 mm to 1 mm, preferably 0.75 mm.
  • the sealing area of the protective cover is formed by an outer edge of the protective cover designed as a peripheral flange.
  • the peripheral flange engages over an annular wall at least partially surrounding the housing opening in the housing wall.
  • the ring wall is advantageously designed as a closed ring wall.
  • peripheral flange of the protective cover and the annular wall of the housing opening overlap each other by more than 50% of the height of the peripheral flange. This results in an extension of the flow path, which prevents dirt particles from penetrating into the gap.
  • the annular wall of the housing opening is advantageously located in the housing wall within the peripheral flange and below the protective cover. This ensures a safe spatial separation from the dirty area.
  • the peripheral flange of the protective cover is angled towards the housing.
  • An angle open to the housing wall is formed between the plane of the protective cover and the peripheral flange itself. This angle is preferably less than 180 °.
  • An angle range between 60 ° and 120 ° is expedient. In particular, the angle has a size of 90 °.
  • the annular wall is part of an annular groove that is formed in the housing wall.
  • the annular groove is open to the peripheral flange. To increase the sealing effect, at least the outer edge of the peripheral flange engages in the annular groove.
  • the annular groove is designed with groove walls of different heights.
  • the ring wall surrounding the housing opening can form a particularly higher groove wall.
  • the protective cover is advantageously designed as a rotary part, in particular as a protective disk, and is fixed on the brake drum in a rotationally fixed manner.
  • the protective cover rotates together with the brake drum.
  • the brake drum expediently has a raised central area which carries the drive element.
  • the protective cover, in particular the protective disk, is designed with a central opening through which the raised area of the brake drum protrudes.
  • the brake drum is designed with a peripheral wall, the peripheral wall lying in the housing opening of the housing wall of the housing.
  • the gap between the rotating brake drum and the housing wall fixed to the housing is formed between the peripheral wall of the brake drum and the opening edge of the housing opening.
  • the protective cover has a maximum external diameter that is greater than the maximum external diameter of the brake drum.
  • the brake drum of the braking device is formed with a peripheral wall which forms a braking surface.
  • the braking element is expediently provided as a braking band, the braking band wrapping around the circumferential wall of the brake drum by more than 180 °.
  • the brake band is arranged in such a way that the wrap angle is greater than 270 ° up to 450 °.
  • the advantage of the brake band is the increase in the contact force achieved by the rotation of the brake drum and the structural design when the brake device is active after the brake band has been applied.
  • FIG. 1 a power tool according to the invention is shown in parts using the example of a motorized chain saw.
  • the working device 1 has a housing 2 which, in the exemplary embodiment, is essentially composed of a base housing 3 and a housing wall 4.
  • a tree claw 25 can be mounted in the front area of the basic housing 3, which can serve to support the implement 1 on the trunk when it is cut to length.
  • a drive motor 22 which can be an internal combustion engine or - as in the exemplary embodiment - an electric motor, in particular an electric motor powered by a rechargeable battery, is accommodated in the base housing 3.
  • a drive shaft 5 protrudes from the base housing 3.
  • a brake drum 6 and a drive element 7 are fixed in a rotationally fixed manner on the drive shaft 5.
  • the brake drum 6 and the drive element 7 are common by a Securing element 12 secured axially on the drive shaft 5.
  • the drive element 7 is advantageously designed in one piece with the brake drum 6.
  • the drive shaft 5 rotates around a shaft axis 28 ( Fig. 2 ).
  • the drive element 7 is formed by a chain wheel 8.
  • the drive element 7 drives a tool 10.
  • the tool 10 shown in the exemplary embodiment is a saw chain 9, which is shown in FIG Figure 1 is indicated schematically.
  • the saw chain 9 revolves on a guide rail 11.
  • the guide rail 11 is secured by means of a sprocket cover 21 ( Figure 2 ) fixed to the housing 2 of the implement 1. This is how Figure 1 shows - a stud bolt 24 is provided on the housing 2.
  • the brake drum 6 is assigned a braking device 13, which essentially consists of a release mechanism 14, a braking element 15 and a braking spring 16.
  • the release mechanism 14 is actuated, in particular mechanically, by a release lever 17.
  • the release lever 17 is designed as a hand guard 18.
  • the hand guard 18 lies in front of an upper handle section 19 of a front handle 20, which is attached to the base housing 3 of the implement 1.
  • the work device 1 which is shown in the exemplary embodiment as a motorized chain saw, is a hand-held, in particular carried, work device.
  • a working device is referred to as carried working device which can be carried by a user during operation and freely guided in all three spatial directions (x-axis, y-axis, z-axis) during operation.
  • the work device 1 can have a front handle 20 and a rear handle 23.
  • the rear handle is preferably designed at least in part in one piece with the base housing 3.
  • the arrangement of the braking device 13, the release mechanism 14 and the brake drum 6 lies in the basic housing 3 and is at least partially covered by the housing wall 4 towards the outside.
  • the drive element 7 projects at least partially beyond the housing wall 4 of the housing 2.
  • the drive element 7 lies under the sprocket cover 21, which is shown in Figure 2 is partially shown at the top left.
  • the sprocket cover 21 is fixed on the housing 2 or the basic housing 3, for which the housing 2 or the basic housing 3 carries the stud bolt 24 which protrudes beyond the housing wall 4.
  • the sprocket cover 21 bounds with the housing 2 a dirt space 50 in which the drive element 7 rotates.
  • the housing wall 4 separates the arrangement of the braking device 13 and the release mechanism 14 from the dirt space 50 of the working device 1.
  • the brake drum 6 protrudes at least in a partial section over the housing wall 4.
  • the brake drum 6 has a raised area 26.
  • the raised area 26 is advantageously a central area of the brake drum 6.
  • the raised area 26 preferably carries the drive element 7.
  • the drive element 7 is connected to the raised area 26 of the brake drum 6 in a rotationally fixed manner. It can be expedient to form the drive element 7 in one piece at least with the brake drum 6, advantageously with the raised area 26 of the brake drum 6.
  • the raised area 26 protrudes through a central opening 38 in the protective cover 41.
  • a gap 40 is formed between the rotating brake drum 6 and the stationary housing wall 4, which gap ensures that the brake drum 6 can rotate freely.
  • the brake drum 6 is designed with a peripheral wall 36 which, in the exemplary embodiment shown, lies in a housing opening 30 in the housing wall 4.
  • the gap 40 lies between the opening edge 31 of the housing opening 30 and the peripheral wall 36 of the brake drum 6.
  • the gap 40 forms a construction-related connection between the dirt space 50 and the braking device 13 located under the housing wall 4.
  • a brake band 35 is provided on the peripheral wall 36 of the brake drum 6 as a brake element 15.
  • the brake band 35 wraps around the brake drum 6 over more than 180 °.
  • the illustrated brake band 35 wraps around the peripheral wall 36 of the brake drum 6 over more than 270 °, in the illustrated embodiment approx. 450 °.
  • the gap 40 which is open to the dirt space 50 of the implement 1, is covered by a protective cover 41, the protective cover 41 lying outside the housing 2 in front of the housing wall 4.
  • the protective cover 41 lies in the dirt space 50 of the implement 1.
  • the protective cover 41 is attached to the brake drum 6.
  • the brake drum 6 carries the protective cover 41.
  • the protective cover 41 rotates together with the brake drum 6.
  • the protective cover 41 serves to seal the gap 40 that is open to the dirt space 50 a gap seal or labyrinth seal 44 forms.
  • the effect of the labyrinth seal or gap seal is based on an extension of the flow path through the gap to be sealed. This lengthening of the path is advantageously achieved by intermingling between the stationary and the rotating part.
  • the outer edge 43 of the protective cover 41 is configured as a peripheral flange 45.
  • the arrangement is such that the circumferential flange 45 engages over an annular wall 32 which at least partially surrounds the housing opening 30.
  • the ring wall 32 is advantageously designed as a closed ring wall.
  • the ring wall 32 lies below the protective cover 41 within the circumferential flange 45 of the protective cover 41.
  • the overlap ü1 between the circumferential flange 45 of the protective cover 41 and the ring wall 32 is at least 50% of the height h of the circumferential flange 45.
  • the circumferential flange 45 preferably overlaps the ring wall 32 the entire height h of the peripheral flange 45.
  • the annular wall 32 forms the side wall of an annular groove 46 which is provided in the housing wall 4 and is open to the peripheral flange 45.
  • the annular groove 46 is designed in particular with groove walls of different heights, the annular wall 32 forming a higher groove wall. It is advantageously provided that the circumferential flange 45 also overlaps the lower groove wall 47. As in the enlarged view in Figure 3 As shown, the circumferential flange 45 of the protective cover 41 overlaps the lower groove wall 47 over an overlap ü2 of up to 50% of the height h of the circumferential flange 45.
  • the arrangement is provided so that at least the outer edge 43 of the protective cover 41 lies in the annular groove 46.
  • the width N of the annular groove 46 is designed in such a way that the engaging outer edge 43 of the protective cover 41 with only a small lateral distance x, y ( Fig. 3 ) is to the groove walls, so that there is sufficient play for the free rotation of the circumferential flange 45 in the annular groove 46.
  • the design is provided so that the outer edge 43 protruding into the annular groove 46 or the engaging peripheral flange 45 of the protective cover 41 is at a smaller distance y from the annular wall 32 than from the lower groove wall 47.
  • the distance x between the peripheral flange 45 and the groove wall 47 is greater than the distance y of the circumferential flange 45 to the annular wall 32.
  • the distance x is 110% to 150% greater than the distance y.
  • the distance x is preferably 125% to 135% larger, in particular 130% larger than the distance y from the annular wall 32.
  • the distance k of the end face 33 of the circumferential flange 45 facing the groove bottom of the annular groove 32 corresponds approximately to the thickness z of the circumferential flange 45.
  • the distance k advantageously corresponds to 30% to 40%, in particular 35% of the width N of the annular groove 46.
  • the width N of the annular groove 46 in such a way that it corresponds approximately to 2 to 5 times the thickness z of the protruding outer edge 43 or the engaging peripheral flange 45.
  • the width N of the annular groove 46 advantageously corresponds to 2.5 to 3.5 times the thickness z of the engaging peripheral flange 45, in particular 3 times the thickness z of the engaging peripheral flange 45.
  • the outer edge 43 of the protective cover 41 is angled to the housing wall 4 and forms the circumferential flange 45. Between the plane 49 of the protective cover 41 and the circumferential flange 45, an angle 48 open to the housing wall 4 is formed. This angle 48 is provided to be smaller than 180 °. The angle 48 is preferably in a range between 60 ° and 120 °. The angle 48 is preferably provided with a size of 90 °.
  • the maximum outside diameter D of the protective cover 41 is advantageously larger than the maximum outside diameter B of the brake drum 6.
  • the outside diameter D of the protective cover 41 is 105% to 125% larger than the outside diameter B of the brake drum 6 selected so that it is 110% to 115% larger than the outer diameter B of the brake drum 6. This ensures that the gap 40 is reliably covered.
  • the labyrinth seal 44 lies outside the housing opening 30 of the housing wall 4.
  • the labyrinth seal 44 lies at a radial distance A from the gap 40.
  • the distance A between the gap 40 and the labyrinth seal is between 1 mm and 10 mm.
  • the distance A is preferably in a range between 2 mm and 6 mm, in particular between 2.5 mm and 3.5 mm.
  • the distance A corresponds to 1.3 times to 1.5 times the width N of the annular groove 46. In particular, the distance A corresponds to 1.4 times the width N of the annular groove 46.

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  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Wood Science & Technology (AREA)
  • Forests & Forestry (AREA)
  • Braking Arrangements (AREA)
EP20157429.0A 2020-02-14 2020-02-14 Appareil de travail, en particulier appareil de travail portable guidé à la main Withdrawn EP3865263A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP20157429.0A EP3865263A1 (fr) 2020-02-14 2020-02-14 Appareil de travail, en particulier appareil de travail portable guidé à la main

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP20157429.0A EP3865263A1 (fr) 2020-02-14 2020-02-14 Appareil de travail, en particulier appareil de travail portable guidé à la main

Publications (1)

Publication Number Publication Date
EP3865263A1 true EP3865263A1 (fr) 2021-08-18

Family

ID=69630155

Family Applications (1)

Application Number Title Priority Date Filing Date
EP20157429.0A Withdrawn EP3865263A1 (fr) 2020-02-14 2020-02-14 Appareil de travail, en particulier appareil de travail portable guidé à la main

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EP (1) EP3865263A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2610085A1 (de) * 1976-03-11 1977-09-22 Stihl Maschf Andreas Motorsaege, insbesondere motorkettensaege
JPS58104701A (ja) * 1981-12-17 1983-06-22 川崎重工業株式会社 チエンソ−の防塵構造
EP0400768A1 (fr) * 1989-05-30 1990-12-05 Blount, Inc. Scie à chaîne
US20130269673A1 (en) * 2011-10-12 2013-10-17 Andreas Stihl Ag & Co. Kg Cutting chain for a hand-operated implement and hand-operated implement
JP2017132238A (ja) * 2016-01-30 2017-08-03 日立工機株式会社 チェンソー

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2610085A1 (de) * 1976-03-11 1977-09-22 Stihl Maschf Andreas Motorsaege, insbesondere motorkettensaege
JPS58104701A (ja) * 1981-12-17 1983-06-22 川崎重工業株式会社 チエンソ−の防塵構造
EP0400768A1 (fr) * 1989-05-30 1990-12-05 Blount, Inc. Scie à chaîne
US20130269673A1 (en) * 2011-10-12 2013-10-17 Andreas Stihl Ag & Co. Kg Cutting chain for a hand-operated implement and hand-operated implement
JP2017132238A (ja) * 2016-01-30 2017-08-03 日立工機株式会社 チェンソー

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