WO2017167829A1 - Verfahren zur herstellung rotationssymmetrischer, nicht zylindrischer bohrungen mit einem honwerkzeug und honmaschine, die zur konifizierung einer zylindrischen bohrung ausgebildet und eingerichtet ist - Google Patents
Verfahren zur herstellung rotationssymmetrischer, nicht zylindrischer bohrungen mit einem honwerkzeug und honmaschine, die zur konifizierung einer zylindrischen bohrung ausgebildet und eingerichtet ist Download PDFInfo
- Publication number
- WO2017167829A1 WO2017167829A1 PCT/EP2017/057458 EP2017057458W WO2017167829A1 WO 2017167829 A1 WO2017167829 A1 WO 2017167829A1 EP 2017057458 W EP2017057458 W EP 2017057458W WO 2017167829 A1 WO2017167829 A1 WO 2017167829A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- bore
- honing
- diameter
- stroke
- actual
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B33/00—Honing machines or devices; Accessories therefor
- B24B33/02—Honing machines or devices; Accessories therefor designed for working internal surfaces of revolution, e.g. of cylindrical or conical shapes
- B24B33/025—Internal surface of conical shape
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B33/00—Honing machines or devices; Accessories therefor
- B24B33/08—Honing tools
- B24B33/087—Honing tools provided with measuring equipment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B33/00—Honing machines or devices; Accessories therefor
- B24B33/08—Honing tools
- B24B33/088—Honing tools for holes having a shape other than cylindrical
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B49/00—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation
- B24B49/02—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation according to the instantaneous size and required size of the workpiece acted upon, the measuring or gauging being continuous or intermittent
- B24B49/04—Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring equipment, e.g. for indicating the start of the grinding operation according to the instantaneous size and required size of the workpiece acted upon, the measuring or gauging being continuous or intermittent involving measurement of the workpiece at the place of grinding during grinding operation
Definitions
- the invention relates to a method for the conification of a cylindrical bore with a honing tool and a
- a honing process is known with the help of the cylinder bore of an internal combustion engine receives a bottle shape.
- a bottle shape while a form is referred to, in which the cylinder bore has two cylindrical portions which have a different diameter. The smaller diameter portion is provided in the area of the cylinder head, while the larger diameter portion is provided in the crankshaft area. Between these areas is a
- the invention is based on the object to provide a honing process, which is the cost-effective and
- the invention has for its object to provide a trained and equipped honing machine.
- the method should allow a variety of user specified cylinder bore geometries accurately and
- the geometries predefined by the user can be, for example, a truncated cone, a bottle shape or a generatrix of the "cylinder bore" of an internal combustion engine that can be predetermined by a polynomial of the nth order.
- a honing tool is used, which has measuring devices which it
- the honing stones have a length which is less than one third of the length of the bore to be machined. The smaller the honing stone length, the more
- the short-wave can be the desired shape course, since with increasing strip length, the wavelengths of the desired shape, which are smaller than the honing stone length, are mechanically filtered out.
- the measuring devices are usually arranged between the honing stones, so that where the material removal takes place and the bore diameter is detected.
- the method according to the invention comprises the steps:
- Perfect measurement means that during the honing process, the diameter of the hole is recorded continuously, as well as with high temporal and spatial resolution. As a result, the actual shape of the hole being processed is already available during honing in real time for controlling the honing process.
- Manipulated variable of the control loop according to the invention is the stroke OP - UP of the honing tool.
- the stroke of the honing tool is from a top turning point OP and a bottom
- the inventive method comprises the steps according to claim 1. More specifically, these steps are explained in the
- Reversal points OP n , UP n no longer being processed. In this way, it is ensured that only one or more regions of the bore are further processed, in which the actual diameter D ACT (y) is still smaller than the desired diameter DSO LL (y) desired there.
- the reduction of the stroke can be done in several ways.
- a control technology very easy relaisierbare
- the stroke H n is always reduced by a predetermined amount DeltaH to one
- the amount of DeltaH is usually chosen as a function of the total length of the hole to be honed. Also, the desired generatrix may affect the amount of DeltaH.
- the hub H n + i is further reduced if n + i, UP n + i of the actual diameter D is at a further reversal point OP (n + i) of the last honed bore portion is equal to the nominal diameter D So ii UPn + i of the bore at this reversal point is OP n + i, UP n + i.
- Interface then forms the new reversal point OP, UP of the honing tool.
- the bore is generally machined over the entire length, so that the inventive method emanating from a cylindrical bore.
- working bore can be used as a mathematical function, e.g. are given as n-th order polynomial as a function of the Y-axis (longitudinal axis of the bore).
- n-th order polynomial as a function of the Y-axis (longitudinal axis of the bore).
- FIGS. 1 a and 1 b schematic representations of an originally cylindrical bore which has been butted with the aid of the method according to the invention
- FIG. 2 an embodiment of the invention
- Figure 5 a similar view as in Figure 2 and the
- FIGS. 6a to d show a further embodiment of the invention
- Bore 1 has a diameter D 0 .
- the diameter D 0 corresponds to the diameter of the bore after prehone when the
- Honing the invention bore the hole over the entire length L conical.
- the generatrix of the conically honed bore is designated by 1 in FIG.
- the same reference numerals for the same components apply to all figures
- the largest diameter D Max is at the lower end of the bore.
- the example with the number 5 is intended to make it clear that rotationally symmetrical bores can also be produced whose largest diameter lies neither at the top nor at the bottom end of the bore.
- the largest diameter D MAX is in this embodiment between the upper and the lower end of the bore.
- the production according to the invention is a non-cylindrical one
- the generatrix of the bore is provided with the reference numeral 1.
- the bore has at its upper end a cylindrical portion and at its lower end another cylindrical
- the diameter in the region of the upper portion b is smaller than the diameter D So ii in the lower section c.
- the starting point of the process according to the invention is a
- Diameter D is , o is used.
- the hole is honed over the entire length of the hole. The turning points of the
- Honing tool or its honing stones are denoted by OPi and UPi (see Figure 2 a).
- the method according to the invention provides for reducing the stroke of the honing tool so that the region b is no longer machined.
- Permant spre also takes a permanent Hubverlagerung to smallest path changes, thereby creating a continuous, stepless shape curve.
- the respective path change is limited only by the resolution of the travel sensor for the lifting movement, which, however, is much smaller than the local slope of the desired shape curve.
- the subsequent smoothing which takes place over the entire length of the bore, the previously developed form is machined to the desired final roughness profile.
- the "stages" shown in FIGS. 2c and 2d are greatly exaggerated
- FIG. 3 illustrates a first variant of the reduction of the stroke according to the invention. This variant is referred to as the "default constant DeltaH for determining DeltaX".
- the honing tool or the honing stones belonging to the honing tool 5 are once in the upper
- the stroke of the honing stones corresponds to the distance OPl and UP when the bore is honed over its entire length.
- An air measuring nozzle which belongs to the honing tool has been provided in Figures 3 and 4 with the reference numeral 7.
- the amount DeltaH can be entered by the operator of the honing machine as a parameter in the control.
- Turnaround point OP2 results from the fact that the previous upper reversal point OP1 is shifted by the amount DeltaH in the direction of the lower turnaround point UP.
- the second setpoint diameter D So ii, 2 is equal to the nominal diameter of the bore at the reversal point OP2.
- the amount of DeltaX is not constant, but depends on the slope of the generatrix in the upper turning point OPl and the new upper turning point OP2. Because the surface line of the bore in the machine control - for example, as a polynomial or as a table of values - is behind, can be at each reversal point OP, UP the associated nominal diameter in
- the reduction of the stroke is more or less large, depending on how much the surface line in the area between the current upper reversal point OP n and the new upper reversal point OP n + 1 changes.
- FIGS. 5 a to d and FIGS. 2 a to d have many similarities. The principle will be explained with reference to FIGS. 2 a to d; in the figures 5a to d of erfindungsgenzeße algorithm with the associated
- the hatched areas 9 lr 9 2 and 9 3 are intended
- Cylinder bores are pressed, their are from the
- Cylinder bore consists in this example of a
- the desired target shape is designated 36.
- thin-walled portion 34 is radially expanded and the desired desired shape according to the line 36 is produced by the method according to the invention, then the bore springs back radially after the end of honing and there is an actual shape according to the line 38 in Figure 6b ,
- Sollform 40 is.
- the corrected nominal shape is the shape which the
- Cylinder bore must accept during honing, so that they have the desired desired shape 36 after the end of the honing and without radial expansion.
- the corrected desired shape is obtained by adding to the desired shape 36 (especially in the region of the thin-walled portion 34) the radial expansion.
- the corrected nominal shape has the reference numeral 42 in FIG. 6c
- the corrected nominal shape 42 compensates for these locally different radial deformations
- the corrected nominal shape 42 can be determined empirically or by calculation. In the case of an empirical determination, it is possible to change iteratively to the corrected desired shape on the basis of the respectively achieved results, starting from the desired shape, by setting the desired shape in small numbers at a plurality of interpolation points
- Steps are corrected until the actual shape (see 38 in Fig. 6c) in the relaxed state of the cylinder bore of the desired shape (see 36 in Fig. 6c) corresponds.
- thin-walled region 34 are determined at least roughly and this expansion is added to the desired shape 36.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Geometry (AREA)
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
- Constituent Portions Of Griding Lathes, Driving, Sensing And Control (AREA)
Abstract
Description
Claims
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US16/088,521 US20190111540A1 (en) | 2016-03-29 | 2017-03-29 | Method for producing rotationally symmetrical, non-cylindrical bores with a honing tool, and honing machine which is designed and equipped for making a cylindrical bore into a conical bore |
MX2018011879A MX2018011879A (es) | 2016-03-29 | 2017-03-29 | Método para producción de agujeros no cilíndricos con simetría rotativa mediante herramienta de bruñido, y máquina de bruñido que está configurada y equipada para conificación de agujero cilíndrico. |
EP17714708.9A EP3436215B1 (de) | 2016-03-29 | 2017-03-29 | Verfahren zur herstellung rotationssymmetrischer, nicht zylindrischer bohrungen mit einem honwerkzeug |
CN201780020240.XA CN108883514B (zh) | 2016-03-29 | 2017-03-29 | 利用珩磨工具生产旋转对称的非圆柱形孔的方法及珩磨机 |
KR1020187031046A KR102279990B1 (ko) | 2016-03-29 | 2017-03-29 | 호닝 툴 및 호닝 머신을 사용하여 원통형 보어를 원추화하도록 설계되고 배치된 회전 대칭의 비-원통형 보어를 생성하기 위한 방법 |
JP2018551315A JP7023240B2 (ja) | 2016-03-29 | 2017-03-29 | ホーニングツール及びホーニング機械を使用して円筒形ボアに傾斜をつけるように設計、構成された回転対称で非円筒形ボアの形成方法 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE102016105717.7A DE102016105717B4 (de) | 2016-03-29 | 2016-03-29 | Verfahren zur Herstellung rotationssymmetrischer, nicht zylindrischer Bohrungen mit einem Honwerkzeug |
DE102016105717.7 | 2016-03-29 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2017167829A1 true WO2017167829A1 (de) | 2017-10-05 |
Family
ID=58461310
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2017/057458 WO2017167829A1 (de) | 2016-03-29 | 2017-03-29 | Verfahren zur herstellung rotationssymmetrischer, nicht zylindrischer bohrungen mit einem honwerkzeug und honmaschine, die zur konifizierung einer zylindrischen bohrung ausgebildet und eingerichtet ist |
Country Status (8)
Country | Link |
---|---|
US (1) | US20190111540A1 (de) |
EP (1) | EP3436215B1 (de) |
JP (1) | JP7023240B2 (de) |
KR (1) | KR102279990B1 (de) |
CN (1) | CN108883514B (de) |
DE (1) | DE102016105717B4 (de) |
MX (1) | MX2018011879A (de) |
WO (1) | WO2017167829A1 (de) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
MX2017015027A (es) * | 2015-05-26 | 2018-04-13 | Gehring Technologies Gmbh | Metodo para la produccion de orificios con simetria rotativa no cilindricos usando una herramienta de bruñido. |
DE102017210187A1 (de) * | 2017-06-19 | 2018-12-20 | Elgan-Diamantwerkzeuge Gmbh & Co. Kg | Honverfahren und Bearbeitungsmaschine zum Konturhonen |
DE102018211685A1 (de) | 2018-07-13 | 2020-01-16 | Elgan-Diamantwerkzeuge Gmbh & Co. Kg | Honverfahren und Bearbeitungsmaschine zum Konturhonen |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4945685A (en) * | 1987-09-19 | 1990-08-07 | Toyota Jidosha Kabushiki Kaisha | Honing apparatus having electrically operated actuator for relative reciprocating movement between honing head and workpiece |
EP1321229A1 (de) * | 2001-12-20 | 2003-06-25 | Maschinenfabrik Gehring GmbH & Co. | Verfahren zur Herstellung einer Bohrung und Honmaschine zur Durchführung des Verfahrens |
US20050130560A1 (en) * | 2003-12-10 | 2005-06-16 | Gehring Gmbh + Co. Kg | Method of Honing Bores |
DE102011076213A1 (de) * | 2011-05-20 | 2012-03-15 | Gehring Technologies Gmbh | Werkzeug mit Zustelleinrichtung und Kraftmesseinrichtung für ein Bearbeitungszentrum |
EP2170556B1 (de) | 2007-08-04 | 2014-06-04 | Gehring Technologies GmbH | Maschine zur erzeugung nicht zylindrischer bohrungsflächen |
WO2014146919A1 (de) * | 2013-03-18 | 2014-09-25 | Elgan-Diamantwerkzeuge Gmbh & Co. Kg | Honverfahren und honwerkzeug |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2020812A (en) * | 1933-05-13 | 1935-11-12 | John W Turner | Boring machine |
US3727927A (en) * | 1968-09-06 | 1973-04-17 | Int Harvester Co | Ring manufacture, productive of line contact seal |
US3971165A (en) * | 1971-11-05 | 1976-07-27 | International Harvester Company | Ring manufacture, productive of face contact seal |
JP2884048B2 (ja) * | 1995-08-08 | 1999-04-19 | 旭ダイヤモンド工業株式会社 | ホーニング砥石 |
JP2001353655A (ja) * | 2000-06-09 | 2001-12-25 | Makino J Kk | ホーニング加工工具及びその工具を用いた加工方法 |
JP2007015036A (ja) * | 2005-07-05 | 2007-01-25 | Nissan Motor Co Ltd | ホーニング加工装置およびホーニング加工方法 |
JP2008023596A (ja) * | 2006-06-23 | 2008-02-07 | Nissan Motor Co Ltd | 微細凹部加工方法 |
KR20120083232A (ko) * | 2011-01-17 | 2012-07-25 | 그롭-베르케 게엠베하 운트 코. 카게 | 정밀 보링과 호닝을 결합한 가공 방법 및 상기 방법의 실시를 위한 가공 장치 |
DE102015203051A1 (de) | 2015-02-20 | 2016-08-25 | Elgan-Diamantwerkzeuge Gmbh & Co. Kg | Honverfahren und Bearbeitungsmaschine zum Formhonen |
DE102015209609B4 (de) | 2015-05-26 | 2024-05-16 | Gehring Technologies Gmbh + Co. Kg | Verfahren zur Konfizierung einer zylindrischen Bohrung und Prozesskette zur formgebenden Bearbeitung von zylindrischen Bohrungen |
CN105221283B (zh) * | 2015-09-22 | 2017-12-05 | 江苏大学 | 一种发动机缸孔及其加工方法 |
-
2016
- 2016-03-29 DE DE102016105717.7A patent/DE102016105717B4/de active Active
-
2017
- 2017-03-29 US US16/088,521 patent/US20190111540A1/en active Pending
- 2017-03-29 EP EP17714708.9A patent/EP3436215B1/de active Active
- 2017-03-29 WO PCT/EP2017/057458 patent/WO2017167829A1/de active Application Filing
- 2017-03-29 MX MX2018011879A patent/MX2018011879A/es unknown
- 2017-03-29 JP JP2018551315A patent/JP7023240B2/ja active Active
- 2017-03-29 KR KR1020187031046A patent/KR102279990B1/ko active IP Right Grant
- 2017-03-29 CN CN201780020240.XA patent/CN108883514B/zh active Active
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4945685A (en) * | 1987-09-19 | 1990-08-07 | Toyota Jidosha Kabushiki Kaisha | Honing apparatus having electrically operated actuator for relative reciprocating movement between honing head and workpiece |
EP1321229A1 (de) * | 2001-12-20 | 2003-06-25 | Maschinenfabrik Gehring GmbH & Co. | Verfahren zur Herstellung einer Bohrung und Honmaschine zur Durchführung des Verfahrens |
US20050130560A1 (en) * | 2003-12-10 | 2005-06-16 | Gehring Gmbh + Co. Kg | Method of Honing Bores |
EP2170556B1 (de) | 2007-08-04 | 2014-06-04 | Gehring Technologies GmbH | Maschine zur erzeugung nicht zylindrischer bohrungsflächen |
DE102011076213A1 (de) * | 2011-05-20 | 2012-03-15 | Gehring Technologies Gmbh | Werkzeug mit Zustelleinrichtung und Kraftmesseinrichtung für ein Bearbeitungszentrum |
WO2014146919A1 (de) * | 2013-03-18 | 2014-09-25 | Elgan-Diamantwerkzeuge Gmbh & Co. Kg | Honverfahren und honwerkzeug |
DE102013204714A1 (de) | 2013-03-18 | 2014-10-02 | Elgan-Diamantwerkzeuge Gmbh & Co. Kg | Honverfahren und Honwerkzeug |
Also Published As
Publication number | Publication date |
---|---|
KR20180126051A (ko) | 2018-11-26 |
MX2018011879A (es) | 2018-12-17 |
EP3436215A1 (de) | 2019-02-06 |
EP3436215B1 (de) | 2023-10-25 |
US20190111540A1 (en) | 2019-04-18 |
CN108883514A (zh) | 2018-11-23 |
DE102016105717A1 (de) | 2017-10-05 |
EP3436215C0 (de) | 2023-10-25 |
CN108883514B (zh) | 2021-08-10 |
JP7023240B2 (ja) | 2022-02-21 |
KR102279990B1 (ko) | 2021-07-22 |
JP2019513563A (ja) | 2019-05-30 |
DE102016105717B4 (de) | 2024-05-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP2976184B1 (de) | Honverfahren und honwerkzeug | |
EP0565742B1 (de) | Verfahren zur Feinbearbeitung von Werkstück-Oberflächen | |
EP1275864B2 (de) | Werkstück mit einer tribologisch beanspruchbaren Fläche und Verfahren zur Herstellung einer solchen Fläche | |
DE10358150B4 (de) | Verfahren zum Honen von Bohrungen | |
EP3164244B1 (de) | Honwerkzeug und honverfahren | |
DE102006062665A1 (de) | Verfahren zur formändernden Bearbeitung einer Bohrung | |
DE102015221714A1 (de) | Verfahren und Vorrichtung zur Herstellung nicht zylindrischer Bohrungen mit mindestens einer Aussparung durch Honen | |
EP3436215B1 (de) | Verfahren zur herstellung rotationssymmetrischer, nicht zylindrischer bohrungen mit einem honwerkzeug | |
DE102015209609B4 (de) | Verfahren zur Konfizierung einer zylindrischen Bohrung und Prozesskette zur formgebenden Bearbeitung von zylindrischen Bohrungen | |
EP3641985B1 (de) | Honverfahren und bearbeitungsmaschine zum konturhonen | |
DE102015203051A1 (de) | Honverfahren und Bearbeitungsmaschine zum Formhonen | |
DE102015203052B4 (de) | Honverfahren zum Formhonen | |
WO2020011541A1 (de) | Honverfahren und bearbeitungsmaschine zum konturhonen | |
EP3271097B1 (de) | Verfahren zur herstellung rotationssymmetrischer, nicht zylindrischer bohrungen mit einem honwerkzeug | |
EP3181249B1 (de) | Verfahren und vorrichtung zum umformen eines werkstücks durch fliesspressen | |
DE102010052271B4 (de) | Honwerkzeug und Verfahren zum Honen der Innenfläche einer Bohrung in einem Werkstück | |
DE19743627A1 (de) | Verfahren zur Herstellung einer Verengung in der Zylinderbohrung einer Zylinderlaufbuchse sowie Zylinderlaufbuchse | |
DE19509912B4 (de) | Verfahren und Vorrichtung zum zielgerichteten Einbringung von Spannungen beim Walzen von Ringen | |
EP0549821A1 (de) | Verfahren zum Honen von Bohrungen und Honwerkzeug zur Durchführung des Verfahrens | |
DE102016104754A1 (de) | Verfahren zur Herstellung rotationssymmetrischer, nicht zylindrischer Bohrungen mit einem Honwerkzeug | |
DE102004046537A1 (de) | Verfahren und Honwerkzeug zur Honbearbeitung, insbesondere von Pleueln | |
DE102014225164A1 (de) | Feinbearbeitungsverfahren zum Herstellen einer rotationssymmetrischen Bohrung mit axialem Konturverlauf |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
WWE | Wipo information: entry into national phase |
Ref document number: MX/A/2018/011879 Country of ref document: MX |
|
ENP | Entry into the national phase |
Ref document number: 2018551315 Country of ref document: JP Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
ENP | Entry into the national phase |
Ref document number: 20187031046 Country of ref document: KR Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2017714708 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 2017714708 Country of ref document: EP Effective date: 20181029 |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 17714708 Country of ref document: EP Kind code of ref document: A1 |