HOWA MACHINERY H3EF, Инструкция по эксплуатации, Страница: 36 / 52

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2.5.5 Balance
When the chuck is additionally machined or equipped with jigs, ensure that the chuck weight is
balanced. Unbalanced chuck will cause vibration and fail to maintain required machining
accuracy. When machining an unbalanced work piece, take the eccentric mass of the work
piece into consideration and rotate the chuck at a low speed. This is because the centrifugal
force due to eccentric mass applies to the top jaws. The chuck balance described in this
manual is based on the standard balance quality (4 mm/s) defined in JIS B0905-1992, and the
unbalance amount of the chuck periphery is specified as shown in Table 4.
(International Standards that correspond to JIS B0905-1992 are ISO1940-1: 1986 and
ISO8821: 1989.)
Table 4
Chuck size 6 8
Max. unbalance (g) 2 3
3. Precautions For Use
3.1 Selecting Top Jaws
The chuck is equipped with a set of standard soft top jaws. We are ready to prepare standard
soft jaws and special top jaws as optional accessories at your request. If necessary, place an
order your from nearest Howa representative. We disclaim all the warranties and responsibility
for accidents caused by use of the top jaws not prepared by Howa.
When using the top jaws that are higher than the standard top jaws,
lower the cylinder force in inverse proportion to the top jaw height.
If the distance H (from the chuck front end face to the gripping position)
is greater than the height X of the standard soft top jaws (dimension X in
the following figure or in the table of dimensions), a force larger than the
allowable value is applied to the top jaw installation bolts even when the
chuck is operated within the permissible cylinder force (specified in the
specification or product catalogue). As a result, the installation bolts may
be broken and the top jaws and/or work piece may come off. This may;
in turn, cause severe personal injury or death to the operator or
bystanders. Even if the top jaws' installation bolt does not break, the
great force exerted upon the sliding portion of the draw bar, due to this
peculiar application procedure, will shorten service life considerably.
Fig.7
For all the chuck parts including consumables, place an order with
Howa Machinery, Ltd.
Howa assumes no responsibility for accidents caused by use of the parts
not prepared by Howa. Any and all warranties are void unless only Howa
genuine parts are used.
Do not use any top jaws which are heavier than those supplied with
this chuck.
If the mounted jaws are heavier than the standard soft jaws or standard
hardened jaws, the chuck will lose extra gripping force by the centrifugal
force due to excess in weight. This, in turn, may cause the ork piece to
fly off and may cause severe personal injury or death to the operator or
bystanders.
WARNING
WARNING
WARNING