U.S. patent application number 09/816604 was filed with the patent office on 2001-10-11 for double moving column grinder with simultaneous two wheel grinding.
Invention is credited to Aznal, Salvador.
Application Number | 20010029160 09/816604 |
Document ID | / |
Family ID | 8493083 |
Filed Date | 2001-10-11 |
United States Patent
Application |
20010029160 |
Kind Code |
A1 |
Aznal, Salvador |
October 11, 2001 |
Double moving column grinder with simultaneous two wheel
grinding
Abstract
A grinding machine (1) that comprises two aligned columns (2,3),
each of said columns (2,3) being provided with one wheelhead (4,5)
with its respective grinding wheels (6,7). The columns (2,3) slide
over a base (9) common to both and parallel to at least one
machining table (11), each of the wheelheads (4,5) has its own
vertical drive system and its own transverse drive system and both
grinding wheels (6,7) may work simultaneously.
Inventors: |
Aznal, Salvador; (Deba,
ES) |
Correspondence
Address: |
THE KLINE LAW FIRM, P.C.
14910 Bonner Court
Morgan Hill
CA
95037-5925
US
|
Family ID: |
8493083 |
Appl. No.: |
09/816604 |
Filed: |
March 23, 2001 |
Current U.S.
Class: |
451/194 ;
451/182; 451/231 |
Current CPC
Class: |
B23Q 39/026 20130101;
B24B 27/0076 20130101; B23Q 39/04 20130101; B24B 41/02 20130101;
B23Q 1/012 20130101 |
Class at
Publication: |
451/194 ;
451/182; 451/231 |
International
Class: |
B24B 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 7, 2000 |
ES |
P 200000896 |
Claims
1. A grinding machine for grinding bulky workpieces of considerable
length, such as frames, columns, tables, etc., which comprises: at
least one machining table on which the workpiece to be ground is
placed, at least two columns linked at the bottom to a carriage,
which slides longitudinally over a base parallel to said machining
table; at least one wheelhead with its respective grinding wheel on
each one of said columns, at least one of said wheelheads being
capable of angle movement; in such a way that the vertical and
transverse drives of the wheelheads of each column are independent
of each other and said wheelheads, therefore, are able to work
simultaneously.
2. A grinding machine according to claim 1, wherein said columns
are facing each other.
3. A grinding machine according to claim 1, wherein the movement of
said carriage over the base is effected by means of a hydrostatic
slideway.
4. A grinding machine according to claim 1, wherein the
longitudinal movement of the carriage is governed by means of a
rack and pinion and encoder system.
Description
TECHNICAL FIELD
[0001] The present invention relates to machines for grinding
workpieces, and more specifically to machines for grinding such
workpieces as frames, columns, tables, etc.
PRIOR ART
[0002] The grinding of workpieces of variable height and length
such as frames, columns, tables, etc. requires the use of two
different types of wheelheads: tangential wheelheads and
angle-movement wheelheads (so-called universal wheelheads).
[0003] The use of conventional single-column flat grinders for
grinding workpieces of this type is already known. For this
purpose, besides using the wheel mounted on this column, another
carriage with another wheel is fitted to the side of the grinding
machine column, generally possessing angle movement. The machining
table moves in relation to the column during the grinding
process.
[0004] The conventional grinding machine has the following
disadvantages:
[0005] It cannot work with the two wheels at the same time, as the
vertical drive is common to both wheels.
[0006] It has a single machining table, so it is necessary to
install costly palletizing systems alongside it for change of
workpiece. In addition, the machine has to be shut off while the
palletizing system is working, with the consequent increase in time
during the grinding process.
[0007] The use of bridge grinders for this purpose is also known.
Bridge grinders are grinding machines with two opposing columns,
one on either side of the machining table, and linked transversely
by a cross rail. The cross rail mounts two wheelheads--one of them
generally capable of angle movement--each of them with its own
vertical drives and its own transverse drives (up to a limited
travel), the cross rail that links both columns being fixed or
vertically movable. During the grinding process the machining table
moves in respect of the columns and the bridge. These machines are
suitable for grinding workpieces of considerable width and variable
lengths.
[0008] The use of a bridge grinding machine has the following
disadvantages:
[0009] It cannot work with both wheels at the same time, as,
although the grinding wheels have their own drive carriages, the
actual machine frame with the cross rail prevents the wheels from
working at the same time as they would have to cross over (the
transverse movement of both wheelheads is effected on a single
support bracket).
[0010] It requires costly palletizing systems for changing
workpieces or high-priced dual table systems, with a dual table
actuating system or table hitch and release systems, besides the
fact that workpiece change means that it is alternately on each
side of the machine.
[0011] Taking into account the workpiece change system, it occupies
a tremendous amount of shop floor space.
[0012] It has a high cost.
DISCLOSURE OF THE INVENTION
[0013] The object of the invention is to provide a grinder with
simultaneous grinding with two different wheels, as is defined in
the claims.
[0014] The grinding machine that is the object of the invention
comprises at least two aligned columns on one side of the machining
table or tables on which the workpieces to be ground are placed,
each of said columns being provided with a wheelhead with its
respective grinding wheel. Each one of said wheelheads has its own
vertical and horizontal drive system, at least one of said
wheelheads is capable of angle movement, and both wheels work
simultaneously. It is the columns that move in relation to the
machining table or tables.
[0015] The machine of the present invention offers the following
advantages:
[0016] As the two wheels work simultaneously, output is practically
doubled. In fact, the total grinding time is the grinding time of
the wheel which has the longer process, as the grinding time of the
other wheel is comprised in this.
[0017] Since it is the columns that move and the heads have all
their movements in relation to said columns, the grinding machine
can grind workpieces placed on different aligned machining tables
consecutively. Thus, the machine can be grinding the workpiece of
one machining table, while the operator handles the workpiece of
another table. In this way, the workpiece change time is nil.
[0018] Taking into account the automatic workpiece change, the
space occupied by the machine is smaller than that of a bridge
machine and even less than a conventional grinding machine, as the
latter requires palletizing systems.
[0019] There is a considerable saving in costs especially in
relation to the use of a bridge machine.
DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is an elevational view of an embodiment of the
machine that is the object of the invention.
[0021] FIG. 2 is a profile view of the machine that is the object
of the invention according to section II-II of FIG. 1.
[0022] FIG. 3 is a profile view of the machine that is the object
of the invention according to section III-III of FIG. 1.
DETAILED DISCLOSURE OF THE INVENTION
[0023] With reference to FIG. 1, the machine 1 of the invention has
two facing and aligned columns 2 and 3, column 2 being provided
with a wheelhead 4 and a grinding wheel 6 and column 3 being
provided with a wheelhead 5 and a grinding wheel 7. Both wheelhead
4 and wheelhead 5 have their own vertical drive system and their
own horizontal drive system and can work simultaneously.
[0024] In the embodiment of FIG. 1 the wheelhead 5 only has
tangential movement, while the wheelhead 4 is capable of being
moved in an angular direction as well.
[0025] FIG. 2 shows the column 2 together with the wheelhead 4 with
its respective grinding wheel 6. FIG. 2 shows said head 4 in three
different positions. Wheelhead 4 has a vertical drive according to
direction B and a horizontal drive according to direction C. It may
be seen that the possibility of angle movement possessed by the
wheelhead 4 permits the grinding of workpieces of widely varying
shapes, such as workpiece 12 for instance. Column 2 is linked to
carriage 8, which slides over base 9.
[0026] Wheelhead 4 is a so-called universal wheelhead, as it is
used in other types of machine and has all the movements possessed
by wheelheads of this type.
[0027] The workpiece 12 for grinding is placed on a fixed machining
table 11 (the machine 1 may have more than one machining table 11).
The workpieces 12 to be ground are bulky items of considerable
length, not usually more than one meter wide, such as frames,
columns, tables, etc for machine tools.
[0028] With reference to FIG. 3, the wheelhead 5 of this embodiment
grinds horizontal flat surfaces. FIG. 3 shows said wheelhead 5 in
three different positions. The movements that said wheelhead 5 has
in relation to the column 3 are the usual ones possessed by the
wheelheads on flat surface grinding machines. Thus, said wheelhead
5 has a vertical drive according to direction D and a horizontal
drive according to direction E.
[0029] Grinding wheels 4 and 5 are large diameter wheels (up to 600
mm) and have high-power servomotors. The grinding with both wheels
is carried out at the same time with a single numeric control that
works in two channels with specific software.
[0030] Columns 2 and 3 of machine 1 are linked at the bottom to a
single lengthwise carriage 8 which slides longitudinally over base
9 according to direction A, as shown in FIG. 1. This movement is
effected by means of a hydrostatic slideway so as to be able to
reach typical conventional grinding speeds (30 m/min).
[0031] The hydrostatic slideway enables considerable accelerations
and decelerations to be achieved and, furthermore, it ensures that
the movement of the columns is uniform, thus preventing the
appearance of a buckling effect in said columns. In the embodiment
of FIG. 1 columns 2 and 3 are linked at the top by means of a cross
member 10 to prevent said buckling effect. With the use of a
hydrostatic slideway, said cross member 10 is not necessary.
[0032] The longitudinal movement of carriage 8 is governed, for
instance, by a rack and pinion and encoder system.
[0033] As the assembly formed by carriage 8, columns 2 and 3 and
their respective wheelheads 4 and 5 move en bloc on base 9, it is
possible to install various aligned machining tables 11, each with
its respective workpiece 12, along the whole length of the base 9
and parallel to said base 9. This means that the machine 1 may be
grinding workpiece 12 of one machining table 11, while the operator
is handling the workpiece 12 of another table 11.
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