[0001] The present invention relates to a hydraulically driving machine tool which can perform
a plurality of machining operations, and more particularly to a hydraulically operating
machine tool which has a base, a column, a die set holder rotatably mounted on the
column and adapted to fixedly hold a plurality of die sets, a frame and a hydraulically
driving device fixed to the frame which are arranged in such a way that a selected
one of the die sets is brought to a single working station right under the hydraulically
driving device by rotating the die set holder and can be fixed onto the base, whereby
a plurality of workpieces can be machined in required different manners at the single
working station as the hydraulically driving device is operated.
[0002] Conventional hydraulically driving machine tools, each of which can perform a plurality
of machining operations, are disclosed in Japanese Unexamined Utility Model Application
Publication No. 54-163147 and Japanese Unexamined Utility Model Application No. 2-114132,
for example.
[0003] The machine tool disclosed in Unexamined Utility Model Application Publication No.
54-163147 includes a main body having a hydraulically operated ram and a moving body
operated integrally therewith. The main body is provided with a cutting device, and
the moving body is provided with a notching device and a bending device so that a
plurality of machining operations can be performed by a single machine tool. The machine
tool disclosed in Unexamined Utility Model Application Publication No. 2-114132 is
adapted to detachably mount various dies on the base of the machine tool so that required
die sets are attached to the machine tool to perform required machining operations.
[0004] In the former machine tool, however, such machining devices as the cutting device,
the notching device and the bending device are moved simultaneously as the ram is
operated. Thus, these machining devices must be surrounded by covers for safety, increasing
the cost of products. Further, this machine tool is encountered with a problem in
that an operator must move to the working position in front of the machining device
with which the required machining operation is to be performed in order to perform
the required machining operation, resulting in poor operation efficiency.
[0005] With the latter machine tool, the die set must be changed every time the kind of
the machining operation is altered. Thus, it takes a long time to change the die sets,
and thus the changing operation is very troublesome.
[0006] The object of the present invention is to provide a hydraulically driving machine
tool in which various die sets each used for a specific machining operation is removably
fixed to a respective die set holder and workpieces can be machined according to the
various contents of machining operations at a single working station of the machine
tool so that a small machine tool which is operated at a high efficiency can be manufactured
at a low cost.
[0007] In order to achieve the object of the present invention, the present invention provides
a hydraulically driving machine tool comprising a base, a frame having a lower end
fixed onto the base and an upper end, a plurality of die set stations at which a plurality
of die sets for holding and machining workpieces to be machined differently from each
other are provided and a hydraulically driving device mounted on the upper portion
of the frame, for operating the die sets so as to machine the workpiece, wherein a
machining station is provided on the base and right under the hydraulically driving
device and a die set holder at required positions of which the die set stations are
provided is slidably mounted on the upper surface of the base in such a manner that
the die sets held at the corresponding die set stations are moved to the machining
station on the base to be positioned thereto.
[0008] In the hydraulically driving machine tool according to the present invention, the
die set holder for fixedly holding a plurality of die sets is rotatably mounted on
the column of the machine tool, the required die set is moved to the working station
by rotating the die set holder and fixed onto the base, and the die set is operated
by the hydraulically driving device to perform the predetermined machining operation
on the corresponding workpiece. This provides a hydraulically driving machine tool
having a simpler and less expensive structure than the conventional machine tool in
which the cutting device, the notching device and the bending device are moved simultaneously
by the operation of the ram. With the conventional machine tool, the operator must
move to the machining station at which the next machining is to be performed. On the
contrary, various machining operations can be performed only at one machining station
in the machine tool of the present invention. Thus, the invented machine tool has
excellent operativeness and exhibits a technical effect in that the die sets can be
changed simply when the machining operation is required to be changed.
Brief Description of the Drawings
[0009]
Fig. 1 is a lateral side view of a hydraulically driving machine tool according to
one embodiment of the present invention;
Fig. 2 is a plan view of the hydraulically driving machine tool shown in Fig. 1;
Fig. 3 is a side view of a holding device used on the machine tool as shown in Figs.
1 and 2 together with a cross sectional view of the portion of the machine tool related
to the holding device;
Fig. 4 is a front view of the hydraulically driving machine as shown in Figs. 1 and
2;
Fig. 5 is a bottom view of a die set holder used on the machine tool as shown in Figs.
1 and 2;
Fig. 6 is a lateral side view of the die set holder shown in Fig. 5, with a half portion
cross-sectioned;
Fig. 7 is a plan view of the die set as shown in Fig. 5;
Fig. 8 is a lateral side view of the die set as shown in Fig. 5; and
Fig. 9 is a cross sectional view of the portion of the hydraulically driving machine
tool showing the hydraulically driving device and a die set at a machining station
on the base of the hydraulically operating apparatus.
[0010] A hydraulically driving machine tool according to the present invention includes
sections comprising a base, a frame, a column, a die set holder, a die set and a hydraulically
driving device. The general structure and operation of an electrically driving machine
tool according to one embodiment of the present invention will be described with reference
to Figs. 1 to 4, and then the sections of the hydraulically driving machine tool will
be described in detail.
[0011] As shown in Fig. 1, a frame 2 has an upper portion 2e bent at its intermediate portion
and extending therefrom substantially in parallel with the upper surface 1a of a base
1 and has a lower end fixed to one end portion of the upper surface 1a of the base
1 by means of bolts 2c. On the substantially central portion of the base 1 is provided
an upright column 3 disposed between the base 1 and the upper portion 2e of the frame
2. The upper portion of the column 3 is fixed to the base 1 by threadably engaging
a male set screw 3b formed on the lower end of the column 3 with a female set screw
1b formed in the base 1, and lower portion of the column 3 is fixed to the upper portion
2e of the frame 2 by means of a male set screw 3c formed on the upper end portion
of the column 3 and a nut 4 threadably engaging the male set screw 3c. The nut 4 is
prevented from being loosened by means of a locking screw 4a.
[0012] A hydraulically driving device 5 is detachably mounted in the free end part of the
upper portion 2e of the frame 2. As shown in Fig. 2, a die set holder 6 having radially
extending horizontal arms 61, 62 and 63 forming a star shape in total is provided
so as to be rotatable around the column 3. A die set 20 is provided in a space between
each pair of adjacent arms and fixed to the adjacent arms. The spaces between the
respective adjacent arms 61 and 62, 62 and 63, and 63 and 61 are hereinafter referred
to as "die set stations S1, S2 and S3".
[0013] In a free state, the die set holder 6 is lifted slightly from the upper surface of
the base 1 by means of a compression coil spring 8 disposed between the base 1 and
the die holder 6.
[0014] A vertical groove 7 is formed in the front end portion of each of the arms 61, 62
and 63 of the die set holder 6. After holding devices 9 have been erected and received
by the grooves 7 in the corresponding arms 61, 62 and 63 of the die set holder 6,
the die set holder 6 can be firmly connected to the base 1 by tightening set screws
10 each forming a fixed position determining device. The fixed positioning determining
device is not limited to the set screws 10 but may be a clamping device or other suitable
fixing means. A washer 30 and a dust seal 31 are provided in the upper end of the
central portion of the central hole of the die holder 6.
[0015] Die sets 20 (only one shown in Fig. 1) performing different machining operations
are mounted at the corresponding die set stations S1, S2 and S3 and can be fixed to
the arms at both sides of the die set stations S1, S2 and S3 by means of screws (not
shown). The die set holder 6 takes a slightly floating state over the base 1 by the
urging force of the compression coil spring 8 when the die set holder 6 is not fixed
to the base 1 by means of the holding devices 9, i.e., when the die set holder 6 is
in the free state so that the die set holder 6 can be easily rotated around the column
3 even if the heavy die sets 20 are attached to the die set holder 6.
[0016] A machining station P is defined right under the hydraulically driving device 5.
When the die set holder 6 is rotated and the selected die set 20 arrives at the machining
station P, the positions of the grooves 7 of the arms 61, 62 and 63 of the die set
holder 6 coincide with the positions of the corresponding holding devices 6. After
the holding devices 9 have been inserted in the vertical grooves 7 in this state,
the set screws 10 are tightened to fixedly position the die sets 20 at the corresponding
die set stations S1, S2 and S3. As the hydraulically driving device 5 is actuated,
the piston of the hydraulically driving device 5 lowers a punch in the die set 20
disposed right under the hydraulically driving device 6, and the die set 20 performs
a predetermined machining operation in cooperation with a die in the die set 20 at
the machining station P. In this case, a force equal to a reaction exerted on the
base 1 and the frame 2 is applied to the column 3, thereby preventing the base 1 and
the frame 2 from being deformed.
[0017] Next, the holding devices 9 are loosened and the die set holder 6 is rotated again
to move the next die set 20 to the machining station P right under the hydraulically
driving device 5. Then, the holding devices 9 are inserted in the corresponding grooves
7 of the die set holder 6 and the set screws 10 are tightened. Thus, the die set 20
which is to be machined next is positioned and fixed at the working station P. As
the hydraulically driving device 5 is actuated again to lower the piston, a workpiece
on the die set 20 newly set at the machining station P is machined in the similar
manner as described above.
[0018] Since the machine tool according to the present invention has a plurality of die
set stations, a plurality of die sets, the machining contents* of which are different
from each other, can be provided on the respective die sets previously or the die
sets can be easily replaced with the suitable ones when the machining operations are
to be changed. The positioning of the die sets can be performed merely by fitting
the holding devices into the grooves 7 in the free end portions of the arms 61, 62
and 63 of the die set holder 6.
*(machining purpose or function)
[0019] Then, the die set holder 6 is rotated around the column 3 to bring the die set 20
to which a workpiece is to be fixed to the machining station P right under the hydraulically
driving device 5. The workpiece is machined in the predetermined way by actuating
the hydraulically driving device 5. In this case, it is unnecessary to move the whole
die set stations together because workpieces at the die set stations other than the
machining station are not machined. Since, therefore, piston mechanisms for machining
the workpieces at the die set stations other than the machining station are not required,
the size of the hydraulically driving machine tool can be reduced in this aspect.
[0020] In this embodiment, the die set stations are defined between the adjacent arms of
the die set holder 6. Since the die sets 20 at the die set stations are disposed on
the upper surface of the base 1, the height of the frame 2 and the frame 2 are made
lower than the case in which the die sets 20 are located on the die holder 6, by an
amount equal to the height of the die set holder 6, thereby reducing the size of the
hydraulically operating machine tool, too.
Structure of the Base
[0021] As shown in Figs. 1 and 2, the base 1 has a planar shape. The upper surface 1a of
the base 1 forms a smooth flat surface, and a threaded insertion hole 1d in which
the lower portion of the column 3 is inserted is formed in the central portion of
the central portion of the base 1. In the portion of the base 1 which is under the
threaded insertion hole 1d is formed the threaded female hole 1b for threadably engaging
the male set screw 3b formed on the lower end of the column 3 so that the column 3
is fixed to the base 1. As shown in Figs. 2 and to 3, a pair of holding devices 9
which are fitted in the respective grooves 7 formed in the free ends of the arms 61,
62 and 63 of the die set holder 6 are provided on both side portions of the base 1
so as to be raised and lowered.
[0022] In Fig. 2, the holding devices 9 at the upper side and the lower side are shown in
a standing state and a falling state (lowered state), respectively. As the set screws
10 of the holding devices 9 which are in a state engaging with the grooves 7 of the
die set holder 6 as shown in Fig. 3 are tightened, the die set holder 6 is moved downward
against the urging force of the compression coil spring 8, and the die set holder
6 can be firmly connected to the base 1. A depression 1f is formed in a portion of
the upper surface 1a of the base 1 which is at the upper end of the threaded insertion
hole 1d so as to hold the lower portion of the compression coil spring 8. The end
portion of the upper surface 1a of the base 1 which is opposite to the end portion
of the upper surface 1a of the base 1 to which the column 2 is fixed forms an inclined
portion 1e for rejecting chips produced from a workpiece by the die sets 20.
[0023] Each holding means for fixing the die set holder 6 to the base 1 is not limited to
the holding device 9 as described above, but may be a clamp or any other suitable
holding means as long as it can fix the die set holder 6 to a predetermined position.
The number of the holding devices can be selected according to the size or other factors
of the machine tool.
Structure of the Frame
[0024] The frame 2 is provided in its lower portion with threaded holes 2d and is fixed
to the base 1 by bolts 2c threadably engaging the threaded holes 2d. The frame 2 has
an L-shaped configuration, and its upper portion 2e is bent at its intermediate portion
so as to extend substantially in parallel with the flat upper surface 1a of the base
1. A column inserting hole 2a is formed in the portion of the upper portion 2e of
the frame 2 which is disposed above the centre of the base 1. Another hole 2b for
removably receiving the hydraulically driving device 5 is formed in the free end portion
of the upper portion 2e of the frame 2.
Structure of the Column
[0025] The column 3 has a large diameter intermediate portion 3a. The portions of the column
3 higher and lower than the large diameter intermediate portion 3a form an shaft portion
3g for supporting the frame 2 and another shaft portion 3h for supporting the die
set holder 6, respectively. The shaft portion 3h rotatably holds the die set holder
5 and is provided on its lower end with the male set screw 3b threadably engaging
the threaded hole 1b in the base 1. The shaft portion 3g for supporting the frame
2 is inserted in the column inserting hole 2a and the upper end portion of the shaft
portion 3g projecting upwardly from the hole 2a is formed with a screw 3c. A nut 4
is threadably engaged with the screw 3c so as to fix the frame 2 to the column 3 with
the upper surface 3e of the large diameter intermediate portion 3a of the column 3
abutted against the lower surface of the upper portion 2e of the frame 2. In the nut
4 there is provided a locking mechanism comprising a slit 4b and locking screw 4a
inserted therein.
[0026] The upper end portion 3f of the shaft portion 3h for supporting the die set holder
6 is formed larger than the shaft portion 3h itself so as to hold the washer 30. The
fixing means for fixing the column to the base is not limited to a set screw but may
be one of various fixing means.
Structure of the Die Holder
[0027] As shown in Fig. 5 showing a bottom view and Fig. 7 showing a side view with a half
portion cross sectioned, the die set holder 6 has a cylindrical central portion 6e
formed with a central through hole 6a in which the shaft portion 3h of the column
3 is inserted. Arms 61, 62 and 63 are arranged at the same circumferential intervals
on the central portion 6e end extend horizontally and radially outward from the outer
peripheral wall of the central portion 6b. Each arm is formed on both sides with threaded
holes 6b opening toward the adjacent arms. A die set 20 is fixed on both sides thereof
to each pair of the adjacent arms by means of screws so that each die set 20 is fixedly
provided between the corresponding adjacent arms. In Fig. 5, only one die set 20 is
shown which is fixed to the corresponding pairs of the arms 62 and 63. The portions
between the adjacent arms 61 and 62, 62 and 63 and 63 and 61 at which the die sets
20 are provided define the die set stations S1, S2 and S3, as already described.
[0028] In the lower part of the central portion 6e of the die set holder 6 is formed a large
diameter hole 6c for receiving the compression coil spring 8. As shown in Figs. 1
and 3, washers 8a and 8b are provided in depression 1f in the upper surface 1a of
the base 1 and the upper end portion of the large diameter hole 6c, respectively,
and the compression coil spring 8 is housed in the large diameter hole 6c with the
lower end portion of the spring 8 received in the depression 1f. When the die set
holder 6 is made rotatable around the central portion 6e of the column 3, that is,
when the die set holder 6 is not fixed to the base 1, the die set holder 6 is raised
slightly from the base 1 by the urging force of the compression coil spring 8. In
this state, the die set holder 6 can be rotated around the column 3 easily because
frictional force between the die set holder 6 and the base 1 is reduced. In this state,
the die set holder 6 is urged downward through the washer 30 by the upper portion
3f of the shaft portion 3h of the column 3 for supporting the die set holder 6 so
that the die set holder 6 is not lifted unnecessarily. A bushing 6d is fitted in the
through hole 6a of the die set holder 6.
[0029] A vertical groove 7 is formed in the front end portion or the free end portion of
each of the arms 61, 62 and 63. A holding device 9 is fitted in the groove 7 of the
corresponding one of the arms and the set screw 10 of the holding device 9 is tightened.
Thus, the die set holder 6 is firmly connected to the base 1 and the die sets 20 are
set to the required positions.
Structure of the Die Sets
[0030] Figs. 7 and 8 are, respectively, a plan view and a lateral side view of a die set
20 for performing cutting operation. Die sets for performing bending operation and
notching operation can also be used. These die sets have same structures as the well-known
conventional ones, the detailed description thereof being omitted, and only a die
set for performing cutting operation will be described.
[0031] The die set 20 as shown in Figs. 7 and 8 has legs 21 extending laterally outward
and horizontally from both sides of the lower portion of the die set 20. Each die
set 20 can be fixed to the die set holder 6 by fixing the legs 21 to the corresponding
adjacent arms on both sides of the die set 20 by means of screws or the like. A die
22 is fixed to each die set 20, and a punch 23 for cutting a workpiece W in cooperation
with the die 22 is vertically slidably provided in the die set 22 so as to cut a workpiece
W in cooperation with the die set 22. As the punch 23 is lowered by the hydraulically
driving device 5 with the workpiece W mounted on the die 22, the workpiece W is cut
by the die 22 and the punch 23.
Structure of the Hydraulically Driving Device
[0032] As shown in Fig. 9, the hydraulically driving device 5 has a vertical cylinder 51
and a piston 52. When a hydraulic pressure is supplied to the interior of the cylinder
51 through a coupling (not shown) from a hydraulic pressure source, the piston 52
is lowered and the die set 20 is operated.
[0033] The piston 52 is slidably provided in the cylinder 51. A stop 53 for determining
the lower limit of the piston 52 is provided in the lower portion of the cylinder
51. A compression coil spring 54 for returning the piston 52 to the original position
is provided between the stop 53 and the piston 52.
[0034] A flange 55 is formed on the lower end of the cylinder 51, and the hydraulically
driving device 5 can be fixed to the frame 2 by connecting the flange 55 to the free
end portion of the frame 2 by means of bolts 56. A vent 57 is formed in the stop 53.
A driving device using compressed air can be used in place of the hydraulically driving
device.
[0035] The units having the above-mentioned structures as described above will be assembled
together with reference to Figs. 1 and 9.
[0036] First, the die set holder 6 provided with the washer 30, the bushing 6d and the dust
seal 31 are mounted on the column 3. After the washer 8b, the compression coil spring
8 and the washer 8a have been mounted on the column 3, the male set screw 3b of the
lower end of the column 3 is threadably engaged with the threaded insertion hole 1d
whereby the column 3 is fixed to the base 1. Next, the upper axial shaft portion 3g
is fitted in the inserting hole 2a and the lower end portion of the frame 2 is fixed
to the base 1 by means of bolts 2c. Then, the nut 4 is threadably mounted on the screw
3c of the upper end portion of the column 3 which extends through the upper portion
2e of the frame 2 , thereby fixing the frame 2 to the column 3. In this way, the assembly
of the base 1, the frame 2 and the column 3 is completed. The hydraulically driving
device 5 is fixed to the free end portion of the upper portion 2e of the so assembled
frame 2 by means of the screws 56, and die sets 20 are arranged at the die set stations
S1, S2 and S3 and are fixed to the corresponding arms 61, 62 and 63. In this way,
the manufacture of the electrically driving machine tool is completed.
[0037] The cutting operation will be described. The required die set 20 is moved to the
machining station P right under the hydraulically driving device 5 by rotating the
die set holder 6. The holding devices 9 pivoted on the base 1 are raised to be fitted
into the grooves 7 formed in the corresponding arms 61, 62 and 63 to be set in position.
As the set screws 10 of the holding devices 9 are tightened in this state, the die
set holder 6 is moved downward against the urging force of the compression coil spring
8, and the undersurface of the die set holder 6 abuts against the flat upper surface
1a of the base 1, whereby the die set holder 6 is fixedly connected to the base 1.
[0038] As a workpiece W is set in the die set 20 and then the hydraulically driving device
5 is operated, the piston 52 is lowered to descend the punch 23 of the die set 20,
whereby performing the predetermined machining operation on the workpiece W (cutting
operation in this case). After the machining operation has been finished, the holding
devices 9 are released. The die set holder 6 is made free and is rotated. The die
set 20 which is to perform the next machining operation is moved to the machining
station P right under the hydraulically driving device 5 and is fixed thereto. The
machining operation is repeated in the similar way to the above-mentioned cutting
operation.
[0039] As mentioned above in the present invention, a plurality of die sets 20 are previously
set on the die set holder 6. The die set holder 6 is rotated to bring a required die
set 20 to the machining station P. Workpieces W to be machined in different ways can
be processed so that the operator can perform different machining operations at only
one position, i.e., without changing the machining position. The die set holder 6
may be adapted to be rotated in one direction or in the forward and reverse directions.
The number of the die sets provided on the die set holder in this embodiment is three
but may be more than three by increasing the number of the arms and the die set stations
according to their necessity. On the other hand, two arms and two die set stations
can be used. The present invention is applicable to various embodiments and modifications
without being departed from the spirits and the principal features of the present
invention. The embodiment as described above is an example only in all respects and
should not be interpreted as being limited thereto. When, in particular, the height
of the hydraulically driving machine tool need not be considered, the die set holder
may be formed in a disc-like shape, a polygonal shape or other shapes and the die
set stations are formed on the outer peripheral portions or the corners of the upper
surface of the die set holder. Further, the die set holder may be moved linearly in
one direction or in both opposite directions in place of rotational movement of the
die set holder.
1. A hydraulically driving machine tool comprising a base (1) having an upper surface
(1a), a frame (2) having a lower end fixed to said base (1) and an upper portion (2e),
a plurality of die set stations (S1, S2, S3) at which a plurality of die sets (20)
for holding and machining workpieces (W) to be worked at different machining operations
from each other are provided, and a hydraulically driving device (5) provided in said
upper portion (2e) of said frame (2), for operating said die sets (20),
characterised in that
a machining station (P) is provided on said base (1) and right under said hydraulically
driving device (5), and a die set holder (6) provided at required positions thereof
with said die set stations (S1, S2, S3) is slidably moved on said upper surface (1a)
of said base (1) to position said die sets (20) at said machining station (P).
2. The hydraulically driving machine tool according to claim 1, characterised in that
at least one holding device (9) for fixing said die set holder (6) to said base (1)
is provided on said base (1) so as to be engageable with and disengageable from said
die set holder (6) when a required one of said die sets (20) is positioned at said
machining station (P).
3. The hydraulically driving machine tool according to claim 2, characterised in that
urging means (8) for lifting said die set holder (6) from said upper surface (1a)
of said base (1) when said holding device (9) is disengaged from said die set holder
(6) is provided between said base (1) and said die set holder (6).
4. The hydraulically driving machine tool according to claim 3, characterised in that
said urging means comprises a compression coil spring (8).
5. The hydraulically driving machine tool according to claim 3 or claim 4, characterised
in that said holding device (9) has one end pivoted on said base (1) so as to take
a horizontal state and a vertical state, and said die set holder (6) is provided with
at least one groove (7) for engaging said holding device (9) when said holding device
(9) takes said vertical state and disengaging from said holding device (9) when said
holding device (9) takes said horizontal state.
6. The hydraulically driving machine tool according to claim 5, characterised in that
said holding device (9) is provided with a fixing position determining device (10)
for fixing said die set holder (6) to said base (1).
7. The hydraulically driving machine tool according to any one of the preceding claims,
characterised in that a column (3) for supporting said frame (2) is provided between
said base (1) and said upper portion (2e) of said frame (2), and said die set holder
(6) is provided on said column (3) so as to be rotated therearound.