U.S. patent application number 11/697311 was filed with the patent office on 2007-10-18 for abrasive tool for collecting dust.
This patent application is currently assigned to 3M Innovative Properties Company. Invention is credited to HITOSHI OKA, SATORU TAKINAMI.
Application Number | 20070243803 11/697311 |
Document ID | / |
Family ID | 38605389 |
Filed Date | 2007-10-18 |
United States Patent
Application |
20070243803 |
Kind Code |
A1 |
OKA; HITOSHI ; et
al. |
October 18, 2007 |
ABRASIVE TOOL FOR COLLECTING DUST
Abstract
An abrasive tool for collecting dust, comprising: an abrasive
material in sheet form having not less than 20 dust collecting
holes; and a backup pad, including: a base material having a first
major surface, a second major surface opposite to the first major
surface, and at least one hole for collecting dust penetrating
through the first major surface and the second major surface; and a
ventilative member connected to the first major surface of the base
material, having an attaching surface to which the abrasive
material is attached, and a plurality of holes extending from the
attaching surface towards the first major surface of the base
material; the ventilative member working jointly with the base
material and making dust flow out from the attaching surface to the
second major surface of the base material.
Inventors: |
OKA; HITOSHI; (TOKYO,
JP) ; TAKINAMI; SATORU; (SAGAMIHARA-SHI, JP) |
Correspondence
Address: |
3M INNOVATIVE PROPERTIES COMPANY
PO BOX 33427
ST. PAUL
MN
55133-3427
US
|
Assignee: |
3M Innovative Properties
Company
|
Family ID: |
38605389 |
Appl. No.: |
11/697311 |
Filed: |
April 6, 2007 |
Current U.S.
Class: |
451/527 |
Current CPC
Class: |
B24D 11/00 20130101;
B24B 55/102 20130101 |
Class at
Publication: |
451/527 |
International
Class: |
B24D 11/00 20060101
B24D011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 14, 2006 |
JP |
2006-112204 |
Claims
1. An abrasive tool for collecting dust, comprising: an abrasive
material in sheet form having not less than 20 dust collecting
holes; and a backup pad, including: a base material having a first
major surface, a second major surface opposite to the first major
surface, and at least one hole for collecting dust penetrating
through the first major surface and the second major surface; and a
ventilative member connected to the first major surface of the base
material, having an attaching surface to which the abrasive
material is attached, and a plurality of holes extending from the
attaching surface towards the first major surface of the base
material; the ventilative member working jointly with the base
material and making dust flow out from the attaching surface to the
second major surface of the base material.
2. The abrasive tool for collecting dust according to claim 1,
wherein said abrasive material in sheet form and said backup pad
are formed in such a manner that when said abrasive material in
sheet form is attached to said surface for attaching an abrasive
material of said backup pad, the number of dust collecting holes
which have effective openings, where dust collecting holes in the
two overlap, is not less than 30% of the total number of dust
collecting holes in said abrasive material in sheet form.
3. The abrasive tool for collecting dust according to claim 1,
wherein said abrasive material in sheet form has an area of
openings of said dust collecting holes of not less than 1% in the
abrasive surface.
4. The abrasive tool for collecting dust according to claim 1,
wherein said abrasive material in sheet form is attached to said
surface for attaching an abrasive material of said backup pad by
means of a surface fastener.
5. The abrasive tool for collecting dust according to claim 1,
wherein the ventilative member has a plurality of discrete vents
defined with a plurality of ventilative walls.
6. The abrasive tool for collecting dust according to claim 1,
wherein the ventilative member has a total open area on the
attaching surface of not less than 15% based on the whole abrasive
material contacting area.
7. The abrasive tool for collecting dust according to claim 1,
wherein the backup pad has a cavity pocket between the ventilative
member and the base material.
8. The abrasive tool for collecting dust according to claim 1,
wherein the ventilative member has at least 15 discrete vents.
9. The abrasive tool for collecting dust according to claim 1,
wherein said abrasive material has a first abrasive surface region
having said open structure and a second abrasive surface region
having no hole structure on the abrasive surface.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Japanese Application No.
2006-112204, filed on Apr. 14, 2006, the disclosure of which is
incorporated by reference in its entirety herein.
TECHNICAL FIELD
[0002] The present invention relates to an abrasive tool for
collecting dust having an abrasive material in sheet form with
holes for collecting dust and a backup pad for supporting abrasive
materials which has a ventilative member.
BACKGROUND
[0003] Soft coated film, pate and the like are abraded in
automobile repairing work and the like. When a soft coated film,
pate or the like is abraded, a large amount of abraded dust or
swarf is created, and therefore, it is necessary to properly
discharge the abraded swarf to prevent clogging of the ventilation
system. Therefore, in conventional abrasive tools it is known to
have openings for collecting dust.
[0004] Such abrasive tools are generally formed of an abrasive
material in sheet form (abrasive cloth or the like) and a backup
pad for supporting the sheet. About 6 or 7 holes for collecting
dust having a diameter of approximately 10 mm are created at
certain points in the abrasive material and in the backup pad.
Thus, the abrasive material in sheet form is mounted on the surface
for attaching an abrasive material of the backup pad, so that the
holes overlap, and openings which penetrate through to the rear
side are formed in the abrasive surface of the abrasive tool.
[0005] Abrading work is carried out by attaching a sander having a
sucking function to the rear surface of the abrasive tool, and
abraded swarf is sucked through the openings in the abrasive
surface and discharged.
[0006] In the present specification, "effective openings" in the
abrasive surface means the portions where dust collecting holes in
an abrasive material and holes in the surface for attaching an
abrasive material of the backup pad overlap. That is to say,
"effective openings in the abrasive surface" are holes which
penetrate through the abrasive surface of the abrasive tool to the
rear surface, and have the function of sucking abraded swarf when
the sander absorbs. In addition, "holes" means through holes,
excluding recesses.
[0007] "Dust collecting holes" and "holes for collecting dust" are
holes which have at least the function of collecting abraded swarf.
In an abrasive material in donut form, for example, the hole in the
center portion which has no relation to the collection of abraded
swarf is not included in "holes for collecting dust."
[0008] When an abrasive material is mounted on the backup pad, the
work of attaching the abrasive material while confirming the
position of the holes in the pad and in the abrasive material by
the eye and positioning the holes is required, which is
troublesome. In the case where the position of the holes in the
abrasive material does not match with the position of the holes in
the backup pad, the number of dust collecting holes having
effective openings becomes small in the abrasive surface, and
therefore, sufficient dust collecting performance cannot be
obtained. Therefore, when the type of abrasive material is changed,
and the position of the holes for collecting dust or the form of
the holes changes, it becomes necessary to change the backup pad
accordingly.
[0009] In order to solve this problem, for example, the holes for
collecting dust in the backup pad may be made in annular groove
form, so that the time and effort for matching the position of the
holes is reduced. However, support of the abrasive material in
portions with annular grooves becomes insufficient. In addition, in
the case where the holes are not created along concentric circles
in the abrasive material, the positions of the holes do not match
the holes in annular groove form, and thus, the problem is not
sufficiently solved.
[0010] In other applications, the dimensions of the holes in the
backup pad are made larger than the dimensions of the holes in the
abrasive material in order to make positioning easier. In this case
also, it is possible that the position of the holes of the abrasive
material will not match that of the backup pad, thus, this too is
an imperfect solution.
[0011] Meanwhile, further increase in the abrading performance, for
example, the shaving performance and the abrading durability, has
been desired in abrasive tools for collecting dust. In order to
achieve this, it is helpful to increase the dust collecting
performance of the abrasive surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a cross sectional diagram showing the structure
(portion) of an abrasive material in sheet form having dust
collecting holes.
[0013] FIG. 2 is a diagram showing the abrasive surface of an
abrasive material in sheet form used in the present invention.
[0014] FIG. 3 is a diagram showing an example of a surface and a
side for attaching a sander of a base material.
[0015] FIG. 4 is a diagram showing an example of a surface and a
side for attaching an abrasive material of a ventilative
member.
[0016] FIG. 5 is a diagram showing another example of a surface and
a side for attaching an abrasive material of a ventilative
member.
[0017] FIG. 6 is a plan diagram showing an example of the opening
structure of a ventilative member.
[0018] FIG. 7 is a plan diagram showing an example of the opening
structure of a ventilative member.
[0019] FIG. 8 is a cross sectional diagram showing a backup pad
according to one embodiment of the present invention.
[0020] FIG. 9 is a cross sectional diagram showing a backup pad
according to another embodiment of the present invention.
[0021] FIG. 10 is a plan view illustrating the form and arrangement
of bridge piers.
[0022] FIG. 11 is a cross sectional diagram showing a backup pad
according to another embodiment of the present invention.
[0023] FIG. 12 is a diagram showing the surface for attaching an
abrasive material of a backup pad according to another embodiment
of the present invention, and a cross section along A-A'.
[0024] FIG. 13 is a diagram showing the surface for attaching an
abrasive material of a backup pad according to another embodiment
of the present invention, and a cross section along B-B'.
[0025] FIG. 14 is a diagram showing the surface for attaching an
abrasive material of a backup pad according to another embodiment
of the present invention, and a cross section along C-C'.
[0026] FIG. 15 is a diagram showing the surface for attaching an
abrasive material of a backup pad and the abrasive surface of an
abrasive tool for collecting dust according to Example 1.
[0027] FIG. 16 is a diagram showing the surface for attaching an
abrasive material of a backup pad and the abrasive surface of an
abrasive tool for collecting dust according to Example 2.
[0028] FIG. 17 is a diagram showing the surface for attaching an
abrasive material of a backup pad and the abrasive surface of an
abrasive tool for collecting dust according to Example 3.
[0029] FIG. 18 is a diagram showing the surface for attaching an
abrasive material of a backup pad and the abrasive surface of an
abrasive tool for collecting dust according to the comparative
example.
[0030] FIG. 19 is a diagram showing the abrasive surface of an
abrasive material in sheet form used in the present invention.
[0031] FIG. 20 is a diagram showing the abrasive surface of an
abrasive material in sheet form used in the present invention.
[0032] FIG. 21 is a diagram showing the abrasive surface of an
abrasive material in sheet form of comparative example.
DISCLOSURE OF THE INVENTION
[0033] The present invention provides an abrasive tool for
collecting dust having an abrasive material in sheet form having
not less than 20 dust collecting holes, and a backup pad for
supporting the abrasive material. The backup pad includes a base
material having a first major surface, a second major surface
opposite to the first major surface, and at least one hole for
collecting dust penetrating through the first major surface and the
second major surface; and a ventilative member connected to the
first major surface of the base material, having an attaching
surface to which the abrasive material is attached, and a plurality
of holes extending from the attaching surface towards the first
major surface of the base material. The ventilative member works
jointly with the base material and makes dust flow out from the
attaching surface to the second major surface of the base material.
With the backup pad and abrasive material disclosed herein, it is
unnecessary to match the position of the holes when the abrasive
material is attached to the backup pad. In this way, labor is
reduced and dust collection performance is not compromised by
mistakes.
[0034] An abrasive tool for collecting dust according to
embodiments disclosed is a combination of an abrasive material in
sheet form having a large number, not less than 20, of dust
collecting holes, and a backup pad having a ventilative member,
characterized in that matching of the position of the holes when
the two are attached to each other becomes unnecessary, and good
dust collecting performance on an abrasive surface at an arbitrary
attachment position, can be secured.
[0035] Here, in order to effectively implement the abrasive tool
for collecting dust having the above described characteristics, it
is preferable to set the respective opening structures of the
abrasive material in sheet form and the backup pad in such a manner
that when the abrasive material in sheet form is attached to the
surface for attaching an abrasive material of the backup pad, the
ratio of the number of dust collecting holes in the abrasive
material in sheet form having effective openings where the dust
collecting holes of the two overlap (hereinafter referred to as
"ratio of the number of effective openings") becomes not less than
approximately 30% of the total number of dust collecting holes in
the abrasive material in sheet form.
[0036] The ventilative member of the backup pad preferably has not
less than 15 dust collecting holes and has a total opening area of
not less than 15% based on the whole abrasive material contacting
area.
[0037] In the following, respective embodiments of the abrasive
material in sheet form and the backup pad, as well as an embodiment
of the abrasive tool for collecting dust where the two are combined
are described.
Abrasive Material in Sheet Form
[0038] FIG. 1 is a cross sectional diagram showing the structure of
an abrasive material in sheet form having dust collecting holes.
The surface of base 101 is coated with a binder 102, and abrasive
grains 103 are made to adhere to base 101 by means of binder 102. A
large number of dust collecting holes 104, 104' . . . are provided
in the abrasive material.
[0039] It is preferable for the edge of the holes on the abrasive
surface side to be cut off. This is because in the case where the
edge of the holes on the abrasive surface side is sharp or
protrudes, there is a risk that the surface to be abraded may be
scratched.
[0040] The holes are preferably formed by carrying out a punching
process on an abrasive material in sheet form. When an abrasive
material is punched, it is preferable for the blade to enter in the
direction from the abrasive surface to the rear surface of the
base. As a result of this, the edge of the holes on the abrasive
surface side is cut off. In addition, the holes may be formed by
punching out the base in advance.
[0041] The base may be any material which is conventionally used as
a base for an abrasive material in sheet form. For example, a
polymer film, a woven cloth, a non-woven cloth, a sheet of paper,
an impregnated sheet of paper, a polymer coated sheet of paper, an
elastomer in foam form or the like can be used. Particularly
preferable bases are oil impregnated sheets of paper, polymer
coated sheets of paper, polyester films, such as polyethylene
terephthalate, and such sheets of paper and films on which a metal
has been vapor deposited. The thickness of the base in one
embodiment is 12 .mu.m to 5000 .mu.m, and in a further embodiment
is 38 .mu.m to 3000 .mu.m.
[0042] Abrasive grains are made to adhere to the surface of the
base by means of a binder. As for the binder, binders which can
secure sufficient adhesive strength and are conventionally used for
an abrasive material for repairing automobiles are used. Phenol
resin, epoxy resin, polyester resin, urethane resin, acryl resin,
urea resin and the like can be cited as examples.
[0043] Many materials may be appropriate for making the abrasive
grains, for example, aluminum oxide, cerium oxide, silicon carbide,
diamond, alumina oxide, including melt alumina, ceramic alumina
(including sol-gel alumina) and the like can be cited. In addition,
the abrasive grains may be fine particles made of plastic, such as
polymethacrylate ester, polystyrene, polyolefin and the like. As
for the dimensions of the abrasive grains, the average grain
diameter is in one embodiment approximately 500 .mu.m to 0.45
.mu.m. That is to say, the average grain diameter is approximately
500 .mu.m (JIS #36) to 0.45 .mu.m (#20000), and in a further
embodiment the average grain diameter is approximately 5 .mu.m
(#2500) to 300 .mu.m (#60).
[0044] The abrasive material may be formed from a coated abrasive
material wherein the abrasive surface is flat and is manufactured
using a base having no dust collecting holes, and after that, a
number of dust collecting holes are formed in the surface of the
base, and thereby, the abrasive material in sheet form can be
manufactured. Alternatively, a number of dust collecting holes may
be formed in the surface of the base, and this base may be coated
with a binder and abrasive grains, and then heated, so that the
binder hardens, and thereby, the abrasive material in sheet form
may be manufactured.
[0045] FIG. 2 is a diagram showing the abrasive surface of the
abrasive material in sheet form that is used in an embodiment of
the present invention. A large number of dust collecting holes 204
and 204' are provided in the abrading surface of this abrasive
material in sheet form 200. The number of dust collecting holes 204
is at least not less than 20, preferably not less than 30, and more
preferably not less than 50. In the case where an abrasive material
in sheet form having at least not less than 20 dust collecting
holes is combined with the backup pad according to the below
described present embodiment, the ratio of the number of effective
openings of not less than approximately 30% can be obtained at an
arbitrary matching position, that is to say, effective openings can
be obtained for approximately 30% of all of the dust collecting
holes in the abrasive surface of the abrasive material in sheet
form.
[0046] Here, it is not always necessary for the dust collecting
holes to be uniformly arranged throughout the entirety of the
abrasive surface, and they may be placed only in the center
portion, as shown in FIG. 2. As described above, in the case where
an area with openings where dust collecting holes are gathered is
arranged and a no hole area is arranged at the periphery, the area
with openings and the no hole area can be used separately, in
accordance with the state of the material to be abraded. In an
abrading finish process, where the discharged amount of abraded
swarf is small and high precision is required on the abrading
surface, for example, in some cases, it is desirable to abrade
mainly with the no hole area.
[0047] The ratio of the total area of the dust collecting holes to
the total area of one surface of the abrasive material (the ratio
of the area of dust collecting holes) is not less than 1%,
preferably 3% to 50%, and more preferably 5% to 40%. In the case
where the ratio of the area of the dust collecting holes is less
than 1%, it becomes difficult to secure a sufficient effective
opening area on the abrasive surface, making the dust collecting
performance of the abrasive surface poor. In the case where the
ratio of the area of the dust collecting holes exceeds 50%, the
abrading performance of the abrasive surface becomes poor.
[0048] The area per dust collecting hole is in one embodiment 0.5
mm.sup.2 to 350 mm.sup.2. In the case where the area of the dust
collecting holes is within this range, the form of the holes may be
any form, including circular, elliptic, polygonal, fan-shaped, leaf
shaped, arched or the like. In the case where the area per dust
collecting hole is not greater than 0.5 mm.sup.2, it becomes easier
for abraded swarf in lump form to clog, making the performance of
discharging abraded swarf poor.
[0049] In the case where the area per dust collecting hole is not
less than 350 mm.sup.2, the sucking force per hole becomes weak,
and abraded swarf cannot be efficiently discharged, particularly
when the abrasive material is used by being mounted on a sander
having sucking function. As a result, no increase is obtained in
the cutting performance. Here, the same is not true for the area of
a large hole in the center portion of an abrasive material in donut
form. In the case where the area per dust collecting hole is 1
mm.sup.2 to 80 mm.sup.2, an additional increase in the cutting
performance can be obtained.
[0050] The distance between end portions of adjacent dust
collecting holes is in one embodiment 1 mm to 20 mm, preferably 3
mm to 10 mm. In the case where the distance between end portions of
adjacent dust collecting holes is not greater than 1 mm, the sheet
strength between the holes becomes weak, causing breaking of the
sheet. In addition, warping is caused in the portion having many
holes, due to the inconsistency in the stress within the sheet, and
the quality of the abrasive material is negatively affected. As a
result of this, no increase in the cutting performance can be
obtained. In the case where the distance between end portions of
adjacent dust collecting holes is not less than 20 mm, the
frequency at which the holes encounter abraded swarf in the
abrading movement of the abrasive material becomes low, and abraded
swarf cannot be efficiently be discharged. As a result of this
also, no increase in the cutting performance can be obtained.
[0051] An appropriate form in a plan view and the dimensions of the
abrasive material in sheet form may be determined in accordance
with the application. Disc form or square sheet form, for example,
are generally used. This is also true for the below described
backup pad.
Backup Pad
[0052] Next, the configuration of a backup pad which is appropriate
for use in an abrasive tool for collecting dust according to the
present disclosure is described. The backup pad for supporting an
abrasive material has a base material and a ventilative member
connected to the base material, having a surface to which an
abrasive material is attached, as its main constitution. The base
material has a first major surface (major surface) to which the
ventilative member is attached, and a second major surface to which
a sander is attached.
[0053] FIG. 3 is a diagram showing an example of a surface and a
side for attaching a sander of a base material. A bolt 2 for
attaching a sander is mounted in the center portion of base
material 1, and 6 holes 3, 3' . . . for collecting dust which
penetrate through to the main surface are provided.
[0054] The configuration of the base material allows abraded swarf
to be sucked from the main surface side of the surface for
attaching a sander, and in addition, is enough to support a
ventilative member as that described below on the main surface, and
is not limited to the example of FIG. 3. The number of holes for
collecting dust may be, for example, increased or decreased. That
is to say, the number of holes for collecting dust may be 1, or a
multiple hole structure or a mesh structure where a number of holes
for collecting dust are gathered to form an opening structure may
be provided.
[0055] It is preferable for the base material to be formed of a
rigid material. This is so that the driving force of the sander can
be efficiently conveyed to the abrasive material. As for the
material for the base material, plastic, fiber reinforced plastic,
metal and the like are used. As the plastic, thermoplastic resins
such as polyethylene, polypropylene, polystyrene,
acrylonitrile/styrene resin, ABS resin, methacrylate resin, vinyl
chloride, polyamide, polyacetal, ultrahigh molecular weight
polyethylene, polyethylene terephthalate, polybutylene
terephthalate, polymethyl pentene, polycarbonate, modified
polyphenylene ether, polyphenylene sulfide, polyether ether ketone,
polytetrafluoroethylene, polyether imide, polyallylate,
polysulfone, polyether sulfone and polyamide imide, as well as
thermosetting resins such as phenol resin, urea resin, melamine
resin, unsaturated polyester resin, alkid resin, epoxy resin and
diallyl phthalate resin, can be cited as examples. As for the
reinforcing fibers of the fiber reinforced plastic, long fibers and
short fibers of, for example, glass fibers, carbon fibers, aramid
fibers and metal fibers, can be cited, and can be used for
reinforcing plastic, as described above. In addition, an
antioxidant, any of a variety of pigments, an ultraviolet ray
absorbent, a filler and the like may be added to this plastic in
order to increase durability, strength and the like. As for the
metal, stainless steel, an aluminum alloy and a magnesium alloy can
be cited.
[0056] FIG. 4 is a diagram showing an example of a surface and a
side for attaching an abrasive material of a ventilative member.
The ventilative member is in sheet form or plate form, and the
surface for attaching an abrasive material has an open structure.
The form of the holes for collecting dust that form the opening
structure is not particularly limited, as long as the function of
making abraded swarf pass through without hindrance is provided. It
may, for example, be polygonal such as triangular and hexagonal,
rectangular, rhombic, star-shaped or elliptical in addition to
circular through holes 21 as shown in FIG. 4(a) and square through
holes 22 as shown in FIG. 4b).
[0057] The dimensions, number and arrangement of the dust
collecting holes is determined in such a manner that the abrasive
material can be supported at the time of the abrading work and the
opening ratio of the abrasive surface for allowing abraded swarf to
pass through without hindrance can be achieved. Appropriate and
preferable values and modes for these are determined taking the
material of the ventilative member and the like into consideration,
and it is desirable for a large number, at least not less than 15,
and in some embodiments not less than 20, dust collecting holes to
be provided.
[0058] FIG. 5 is a diagram showing another example of a surface and
a side for attaching an abrasive material of a ventilative member.
The abrasive material fitting surface as shown in FIG. 5(a) has
corrugated mesh structure 31. The abrasive material fitting surface
as shown in FIG. 5(b) has grid mesh structure 32. The mesh
structure comprises a plurality of through holes assembled in its
opening structure.
[0059] The opening structure of the ventilative member allows
abraded swarf to pass through and is sufficient as a structure to
which an abrasive material can be attached, and thus, is not
limited to the above described example. FIGS. 6 and 7 are plan
diagrams showing other examples of the opening structure of the
ventilative member. A plurality of openings 41, 51 is assembled in
the abrasive material fitting surface 40, 50 in every structural
example.
[0060] FIG. 6 illustrates circular sheet-like abrasive materials,
wherein (a) is structure made of parallel array of octagonal holes,
(b) is structure such that hexagonal holes are combined with a
grid, (c) is structure made of a diffusive array of hexagonal
holes, (d) is structure made of an array of different sized holes,
(e) is structure made of a plurality of concentric circumferential
holes, (f) is structure made of a plurality of corrugated linear
holes. FIG. 7 illustrates rectangular sheet-like abrasive
materials, wherein (a) is a structure made of a parallel array of
hexagonal holes, (b) is a structure wherein linear holes are
alternately arranged, (c) is structure made of a plurality of
corrugated linear holes, (d) is a structure made of a parallel
array of square holes.
[0061] The ratio of the total opening area on the abrasive material
attaching surface of the ventilative member, based on the whole
abrasive material contacting area (hereinafter referred to as "hole
area ratio") is not limited to, but preferably is not less than
15%, and, in one embodiment 30% to 80%, and in a further
embodiment, 30% to 70%. In the case where the ratio of the hole
area is less than 15%, it becomes difficult to secure the ratio of
the number of effective openings in the abrasive surface of the
abrasive material in sheet form, making the dust collecting
performance of the abrasive surface poor. In the case where the
ratio of the hole area exceeds 70%, support of the abrasive
material becomes difficult.
[0062] The "whole abrasive material contacting area" means the
total area on the backup pad which contacts with the abrasive
material as an abrasive material is attached to the ventilative
member. So when the annular support or the annular wall surrounding
the abrasive material attaching surface of the ventilative member,
described as follows, are present, the area on the annular support
or the annular wall which contacts with an abrasive material are
also comprised in the area.
[0063] The ventilative member may be formed of a material having a
sufficient strength to support an abrasive material and implement
abrading function. As the material of the ventilative member, one
or more types from among, for example, thermoplastic resins such as
polyethylene, polypropylene, polystyrene, acrylonitrile/styrene
resin, ABS resin, methacrylate resin, vinyl chloride, polyamide,
polyacetal, ultrahigh molecular weight polyethylene, polyethylene
terephthalate, polybutylene terephthalate, polymethyl pentene,
polycarbonate, modified polyphenylene ether, polyphenylene sulfide,
polyether ether ketone, polytetrafluoroethylene, polyether imide,
polyallylate, polysulfone, polyether sulfone and polyamide imide,
thermosetting resins such as phenol resin, urea resin, melamine
resin, unsaturated polyester resin, alkid resin, epoxy resin,
diallyl phthalate resin, as well as elastomers which are natural or
synthetic rubber elastomers such as polyurethane, natural rubber,
polybutadiene, polyisoprene, EPDM polymer, polyvinyl chloride
(PVC), polychloroprene, nitrile rubber, silicone rubber, fluorine
rubber and styrene/butadiene copolymer, are used. The ventilative
member is formed of one or more types from among non-woven cloths
made of molded products of these materials, foamed materials having
open cells or closed cells and natural fibers, and thermoplastic
resins. In addition, an antioxidant, any of a variety of pigments,
an ultraviolet ray absorbent, a filler and the like may be added to
these sheet materials for attaching an abrasive material, in order
to increase the durability, the strength and the like.
[0064] The ventilative member is supported on the main surface of
the base material so as to form a backup pad.
[0065] In a preferred embodiment, the ventilative member is
supported so as to be approximately parallel to the main surface
with a gap vis-a-vis the main surface in a supporting structure. In
this manner, a space is formed between the base material and the
ventilative member, and this space connects the opening structure
of the ventilative member to holes for collecting dust in the base
material.
[0066] As a result, abraded swarf that is created during the
abrading work is sucked into dust collecting holes in the abrasive
material, and can be freely moved toward any of the holes for
collecting dust in the base material after passing through the
opening structure, and thus, the efficiency of dust collection is
increased. The space which connects the holes for collecting dust
of the base material to become ventilative channel (cavity pocket)
is referred to as the dust pocket in the present specification.
[0067] The dust pocket connects, for example, at least two holes
which form the opening structure of the ventilative member to at
least one hole for collecting dust of the base material.
Preferably, the dust pocket connects essentially all of the holes
that form the opening structure of the ventilative member to at
least one hole for collecting dust of the base material. Here,
essentially all of the holes mean holes where the connection of air
is maintained in a state where the backup pad is completed. That is
to say, the meaning excludes holes which are clogged by making
contact with a structural material or a binder for supporting the
ventilative member.
[0068] The dust pocket may be divided into a number of spaces.
However, the dust pocket preferably forms one space, and all the
holes that form the opening structure of the ventilative member are
connected to an arbitrary hole for collecting dust in the base
material.
[0069] FIG. 8 is a cross sectional diagram showing a backup pad
according to one embodiment of the present invention. This backup
pad has a base material 1 and a ventilative member 4. The base
material 1 has holes for collecting dust 3, 3' . . . and
ventilative member 4 has an open structure including holes 11, 11'
. . . .
[0070] FIG. 9 is a cross sectional diagram showing a backup pad
according to another embodiment of the present invention. This
backup pad has a base material 1 having an annular support that is
formed and integrated with the outer peripheral portion, a rigid
sheet material 8 which is placed over the annular support, and a
ventilative member 4. The base material 1 has holes for collecting
dust 3, 3' . . . and the ventilative member 4 and the rigid sheet
material 8 have an open structure of matching holes 11, 11' . . .
.
[0071] The ventilative member 4 is supported by the annular support
of the base material 1 and the rigid sheet material 8 so as to be
approximately parallel to the main surface with a gap vis-a-vis the
main surface. In addition, a dust pocket 7 for connecting the holes
for collecting dust from the open structure of holes 11 is formed
so as to be adjacent to the main surface of base material 1.
[0072] Ribs (not shown) may be formed on the surface of the base
material 1 or the rigid sheet material 8, in order to enhance the
rigidity. In addition, bridge piers may be made on the main surface
of the base material 1, in order to support the rigid sheet
material 8 and counteract the pressure at the time of abrading
work.
[0073] FIG. 10 is a plan diagram showing the form and the
arrangement of the bridge piers. FIG. 10(a) to (e) are plan views
exemplifying form and disposition of bridge piers. A plurality of
bridge piers 81 is elected on the major surface 80 of the substrate
sheet material in every example. FIG. 10 shows disposition of
bridge piers, of diffusive linear walls in (a); circumferential
cylinders in (b); diffusive curved walls in (c); circumferential
square poles in (d); and circumferential curved walls in (e).
Furthermore, dust collecting holes 12, 12' . . . may be provided on
the sidewalls of the backup pad so as to enhance the effects of
dust collection.
[0074] The bridge piers may be formed of the same material as, for
example, the base material, the rigid sheet material or the
ventilative member, or may be formed so as to be integrated with
the base material or the rigid sheet material. Appropriate
properties for the bridge piers, for example, elasticity and
strength, may be adjusted, and the bridge piers may be formed of a
rigid material, such as a metal.
[0075] FIG. 11 is a cross sectional diagram showing a backup pad
according to another embodiment of the present invention. This
backup pad has a base material 1, an annular support 9, a rigid
sheet material 8 that is placed over the annular support 9, and a
ventilative member 4. The base material 1 has holes for collecting
dust 3, 3' . . . and the ventilative member and the rigid sheet
material has an open structure of matching holes 11, 11' . . .
.
[0076] The ventilative member 4 is supported by the annular support
9 and the rigid sheet material 8 so as to be approximately parallel
to the main surface with a gap vis-a-vis the main surface. In
addition, a dust pocket 7 for connecting the holes for collecting
dust from the open structure is formed so as to be adjacent to the
main surface of base material
[0077] The supporting structure is made of a bridge and bridge
girder in the embodiments shown in FIGS. 9 and 11, and the bridge
corresponds to the annular support 9 and the bridge girder
corresponds to the rigid sheet material 8. The rigid sheet material
8 has a diameter size that is not shorter than the inner diameter
size of the annular support and not longer than the outer diameter
size. The thickness of the rigid sheet material is determined
taking the strength of this material into consideration, so that
the ventilative member 4 can be appropriately supported.
[0078] The annular support 9 may have any form, for example, it may
have a cylindrical form or a form of which the cross section is
trapezoid, as long as it holds the rigid sheet material 8. In
addition, the annular support may be formed of, for example, the
same material as the bridge pier. Appropriate properties of the
annular support, for example, elasticity and strength, may be
adjusted.
[0079] As the material of the rigid sheet material 8, one or more
types from among, for example, thermoplastic resins such as
polyethylene, polypropylene, polystyrene, acrylonitrile/styrene
resin, ABS resin, methacrylate resin, vinyl chloride, polyamide,
polyacetal, ultrahigh molecular weight polyethylene, polyethylene
terephthalate, polybutylene terephthalate, polymethyl pentene,
polycarbonate, modified polyphenylene ether, polyphenylene sulfide,
polyether ether ketone, polytetrafluoroethylene, polyether imide,
polyallylate, polysulfone, polyether sulfone and polyamide imide,
thermosetting resins such as phenol resin, urea resin, melamine
resin, unsaturated polyester resin, alkid resin, epoxy resin,
diallyl phthalate resin, and fiber reinforcing resins obtained by
reinforcing these resins with long fibers and short fibers of, for
example, glass fibers, carbon fibers, aramid fibers and metal
fibers, as well as elastomers which are natural or synthetic rubber
elastomers, such as polyurethane, natural rubber, polybutadiene,
polyisoprene, EPDM polymer, polyvinyl chloride (PVC),
polychloroprene, nitrile rubber, silicone rubber, fluorine rubber
and styrene/butadiene copolymer, in addition to metals such as
stainless steel, aluminum alloys and magnesium alloys, are used. In
addition, an antioxidant, any of a variety of pigments, an
ultraviolet ray absorbent, a filler and the like may be added in
order to increase the durability, the strength and the like.
[0080] The opening structure of the rigid sheet material 8 is not
limited, as long as it can appropriately support the ventilative
member 4, and has a ratio of openings for allowing abraded swarf to
pass through without hindrance. The form of the holes may be, for
example, a lattice form having a side of not less than 0.5 mm, a
circular form having a diameter of not less than 0.5 mm, a
rectangle, a diamond, a triangle, a quadrilateral, a polygonal, a
star shape, a circle, an ellipse or the like. In addition, the
opening structure may be a mesh structure.
[0081] Ribs, bridge piers, dust collecting holes in the sidewalls
and the like may further be provided to the embodiment of FIG. 11,
in the same manner as the embodiment shown in FIG. 9.
[0082] FIG. 12 is a diagram showing a surface for attaching an
abrasive material of a backup pad according to one embodiment of
the present invention, and a cross section along A-A'. This backup
pad has a base material 1 having holes for collecting dust, a
number of bridge piers 6, 6' . . . which are secured to the top of
the main surface, and ventilative member 4 which is supported by
the bridge piers. An annular wall 5 is provided around the outer
periphery of the ventilative member 4. A dust pocket 7 for
connecting the holes for collecting dust to the opening structure
is formed between the base material and the ventilative member.
[0083] FIG. 13 is a diagram showing a surface for attaching an
abrasive material of a backup pad according to another embodiment
of the present invention, and a cross section along B-B'. This
backup pad has a base material 1 having holes for collecting dust,
an annular support 9 that is secured along the outer peripheral
portion of the main surface, a rigid sheet material 8 that is
placed over the annular support, and a ventilative member 4 that is
secured to the rigid sheet material. An annular wall 5 is provided
around the outer periphery of the ventilative member 4.
[0084] FIG. 14 is a surface for attaching an abrasive material of a
backup pad according to another embodiment of the present
invention, and a cross section along C-C'. In this embodiment,
rigid sheet material 8, which is a bridge girder, is supported by a
number of supports in pillar form 10, 10' . . . which are bridge
piers in the backup pad shown in FIG. 13. As a result of this, the
strength of the rigid sheet material 8 for supporting a ventilative
member 4 is further increased. At this time, ventilative member 8
made of a metal or a resin is provided irrespectively of the
dimensions of an annular support 9. In addition, the annular
support 9 may have any form, including a cylindrical form or a form
of which the cross section is a trapezoid. An appropriate
arrangement pattern, number and material of the supports in pillar
form may be determined.
Abrasive tool for Collecting Dust
[0085] An abrasive material in sheet form as that described above
is secured to a surface for attaching an abrasive material of a
backup pad, and thereby, an abrasive tool for collecting dust
according to the present embodiment is obtained. Conventional
members for fixing an abrasive material may be used. As for a
useful member for fixing an abrasive material, surface fasteners
and adhesives can be cited as examples. In the case where a surface
fastener is used, a clearance is created between the abrasive
material and the backup pad, and this clearance functions as a
channel for collecting abraded swarf, and therefore, the efficiency
of dust collection can further be increased. In the case where a
surface fastener is used, a surface fastener in loop form is
attached to either of the rear surface of the sheet abrasive
material for collecting dust and the surface for attaching an
abrasive material of a backup pad, and a surface fastener in hook
form is attached to the other. The height of the clearance can be
adjusted using the height of the loops, and it can be made to be
not smaller than 0.5 mm, preferably not smaller than 1 mm to 2 mm,
in order to make it function as a channel for collecting dust.
[0086] In the abrasive tool for collecting dust according to the
present embodiment, it is not necessary to make an abrasive
material in sheet form match in position with the holes when it is
attached to the backup pad. The ratio of the number of effective
openings of the abrasive surface, that is to say, the ratio of the
number of dust collecting holes having effective openings to the
total number of dust collecting holes of the abrasive material is
not less than 30%, preferably not less than 40%. That is to say,
whichever the direction in which the abrasive in sheet form for
collecting dust is placed, the area of the effective openings in
the abrasive surface can be secured so as to have not less than a
certain value, and the dust collecting performance of the abrasive
surface is maintained. This is because the abrasive material in
sheet form has an area ratio of dust collecting holes which is not
less than a certain value, and the surface for attaching an
abrasive material of the backup pad has an open structure where a
number of holes are gathered, and therefore, the dust collecting
holes of the abrasive material and the holes in the surface for
attaching an abrasive material of the backup pad easily overlap.
Here, in the case where the ratio of the number of effective
openings is less than 30%, the increase in the dust collecting
performance of the abrasive surface becomes insufficient.
[0087] Though the present invention is concretely described using
the following examples, the present invention is not limited to
these.
EXAMPLES
Example 1
[0088] Holes were created in an abrasive material "Disc Unicut
P400" having a diameter of 125 mm, made by Sumitomo 3M Ltd., and
thereby, the opening structure shown in FIG. 2 was formed. The area
per dust collecting hole that forms the opening structure was 19.6
mm.sup.2, the distance between end portions of adjacent dust
collecting holes was 5 mm, the number of holes is 69, and the area
ratio of the dust collecting holes was 1%.
[0089] Holes were created in a sheet material made of synthetic
leather with a surface fastener made of nylon having a thickness of
1 mm to 2 mm, and this was used as a ventilative member, and
thereby, a backup pad having an opening structure in the surface
for attaching an abrasive material was fabricated. FIG. 15(a) is a
plan diagram showing this surface for attaching an abrasive
material. The area per hole that forms the opening structure was
52.6 mm.sup.2, the distance between end portions of adjacent holes
was 4 mm, the number of dust collecting holes was approximately 65,
and the area ratio of the holes was 28%.
[0090] The above described abrasive material in sheet form was
secured to the surface for attaching an abrasive material of the
backup pad using a surface fastener, so that the clearance became 2
mm, and thus, an abrasive tool for collecting dust was obtained. It
is not necessary to match the position of the holes of the abrasive
material when the abrasive material is attached, and the work of
attachment was easy.
[0091] FIG. 15(b) is a plan diagram showing an example of an
abrasive surface of an abrasive tool for collecting dust. The
openings of the abrasive surface are shown as dark regions. In the
case where the abrasive material in sheet form and the backup pad
are attached to each other in a state where the center of the two
approximately overlaps at an arbitrary rotational position, the
ratio of the dust collecting holes having effective openings from
among the dust collecting holes of the abrasive surface, that is to
say, the ratio of the number of effective openings, was always not
less than 75%, irrespectively of the rotational position.
[0092] This abrasive tool for collecting dust was mounted on a
double action sander "PN3965," made by Sumitomo 3M Ltd., and a pate
("LUC Poly-Putty," made by Kansai Paint Co., Ltd.) was abraded.
Continuous abrading for 3 minutes was carried out six times, and
the weight of the pate that was abraded off was added up as the
abraded amount. The results of the abrading test are shown in Table
1. In the table, the abraded amount is shown as a value that is
calculated so that the abraded amount in the comparative example
becomes 100%.
[0093] Next, an abrasive tool for collecting dust was obtained in
the same manner as described above, except that an adhesive was
used instead of a surface fastener as a member for fixing an
abrasive material, and then, a abrading test was carried out. The
results of the abrading test are shown in Table 1.
Example 2
[0094] Holes were created in a sheet material of which the
thickness and the material were the same as those in Example 1, and
this was used as a ventilative member, and a backup pad having an
opening structure on the surface for attaching an abrasive material
was fabricated. FIG. 16(a) is a plan diagram showing this surface
for attaching an abrasive material. The area per hole that forms
the opening structure was 100 mm.sup.2, the distance between end
portions of adjacent holes was 4 mm, and the area ratio of the
holes was 33%.
[0095] An abrasive tool for collecting dust was obtained in the
same manner as in Example 1, except that this backup pad was used,
and a abrading test was carried out. FIG. 16(b) is a plan diagram
showing an example of the abrasive surface of the abrasive tool for
collecting dust. The effective openings of the abrasive surface are
shown as dark regions. In this case, the ratio of the number of
effective openings of the abrasive surface was always not less than
61%, irrespectively of the position of attachment between the
abrasive material and the backup pad. The results of the abrading
test are shown in Table 1.
Example 3
[0096] Holes were created in a sheet material of which the
thickness and the material were the same as those in Example 1, and
this was used as a ventilative member, and a backup pad having an
opening structure on the surface for attaching an abrasive material
was fabricated. FIG. 17(a) is a plan diagram showing this surface
for attaching an abrasive material. The area per hole that forms
the opening structure was 42.3 mm.sup.2, the distance between end
portions of adjacent holes was 4 mm, and the area ratio of the
holes was 24%.
[0097] An abrasive tool for collecting dust was obtained in the
same manner as in Example 1, except that this backup pad was used,
and a abrading test was carried out. FIG. 17(b) is a plan diagram
showing an example of the abrasive surface of the abrasive tool for
collecting dust. The effective openings of the abrasive surface are
shown as dark regions. In this case, the ratio of the number of
effective openings of the abrasive surface was always not less than
54%, irrespectively of the position of attachment between the
abrasive material and the backup pad. The results of the abrading
test are shown in Table 1.
Example 4
[0098] Holes were created in an abrasive material "Disc Unicut
P400" having a diameter of 125 mm, made by Sumitomo 3M Ltd., and
thereby, the opening structure shown in FIG. 19 was formed. The
area per dust collecting hole that forms the opening structure was
19.6 mm.sup.2, the distance between end portions of adjacent dust
collecting holes was 7 mm, the number of holes is 57, and the area
ratio of the dust collecting holes was 9%.
[0099] An abrasive tool for collecting dust was obtained in the
same manner as in Example 1, except that this abrasive material in
sheet form was used, and a abrading test was carried out. In this
case, the ratio of the number of effective openings of the abrasive
surface was always not less than 52%, irrespectively of the
position of attachment between the abrasive material and the backup
pad. The results of the abrading test are shown in Table 1.
Example 5
[0100] Holes were created in an abrasive material "Disc Unicut
P400" having a diameter of 125 mm, made by Sumitomo 3M Ltd., and
thereby, the opening structure shown in FIG. 20 was formed. The
area per dust collecting hole that forms the opening structure was
38.5 mm.sup.2, the distance between end portions of adjacent dust
collecting holes was 7 mm, the number of holes is 32, and the area
ratio of the dust collecting holes was 10%.
[0101] An abrasive tool for collecting dust was obtained in the
same manner as in Example 1, except that this abrasive material in
sheet form was used, and a abrading test was carried out. In this
case, the ratio of the number of effective openings of the abrasive
surface was always not less than 88%, irrespectively of the
position of attachment between the abrasive material and the backup
pad. The results of the abrading test are shown in Table 1.
Comparative Example 1
[0102] A backup pad ("Disc Pad 5595, 5581") made by Sumitomo 3M
Ltd. was prepared. FIG. 18(a) is a plan diagram showing the surface
for attaching an abrasive material. The area per hole was 95
mm.sup.2, the distance between end portions of adjacent holes was
27 mm, the number of holes was 6, and the area ratio of the holes
was 5%.
[0103] An abrasive tool for collecting dust was obtained in the
same manner as in Example 1, except that this backup pad was used,
and a abrading test was carried out. FIG. 18(b) is a plan diagram
showing an example of the abrasive surface of the abrasive tool for
collecting dust. The effective openings of the abrasive surface are
shown as dark regions. In this case, the ratio of the number of
effective openings of the abrasive surface was 10%. The results of
the abrading test are shown in Table 1.
Comparative Example 2
[0104] Holes were created in an abrasive material "Disc Unicut
P400" having a diameter of 125 mm, made by Sumitomo 3M Ltd., and
thereby, the opening structure shown in FIG. 21 was formed. The
area per dust collecting hole that forms the opening structure was
38.5 mm.sup.2, the distance between end portions of adjacent dust
collecting holes was 12 mm (linear direction), the number of holes
is 17, and the area ratio of the dust collecting holes was 5%.
[0105] An abrasive tool for collecting dust was obtained in the
same manner as in Example 1, except that this abrasive material in
sheet form was used, and a abrading test was carried out. In this
case, the ratio of the number of effective openings of the abrasive
surface was always not less than 88%, irrespectively of the
position of attachment between the abrasive material and the backup
pad. The results of the abrading test are shown in Table 1.
TABLE-US-00001 TABLE 1 x. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 C. Ex. 1 C. Ex.
2 Number of dust collecting 69 69 69 57 32 69 17 holes of dust
collecting abrasive sheet Number of dust collecting About About
About About About 6 About 65 holes of surface for 65 45 69 65 65
attaching abrasive material of backup pad Area ratio of holes of
28% 33% 24% 28% 28% 5% 28% backup pad Minimum ration of 75% 61% 54%
52% 88% 10% 88% number of effective openings of abrasive surface of
abrasive tool for collecting dust Abraded amount (fixed 140% 143%
122% 123% 113% 100% 107% with surface fastener) Abraded amount
(fixed 121% 114% 109% -- -- 100% -- with adhesive)
* * * * *