Transfer press and method of driving its slides

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a transfer press and a method of driving slides thereof, and more particularly, to a transfer press, in which a plurality of slides are provided, and a method of driving slides used in the transfer press, or to a transfer press, in which a plurality of units each composed of a crown, slide and a bed are arranged linearly and uprights are provided between adjacent units to be common thereto, and a method of driving slides used in the transfer press.

2. Description of the Related Art

Conventionally, a transfer press has been known, in which slides conformed to at least one working station. Such transfer press is frequently used in the case where stations are large in number, the case where workpieces are large in size, the case where an overall pressing force is great, or the case where a blanking station is provided for use of a coiled stock.

In such transfer press, respective slides are driven substantially at the same time by one main motor common to all the slides. Also, provided in the transfer press are a set of a flywheel rotated constantly by the main motor, a clutch for intermittently transmitting energy of the flywheel to the respective slides, and a brake for stoppage of movements of the slides, in addition to the main motor.

Also, in recent years, a transfer press has been known, in which units each composed of a set of a crown, slide and a bed are modularized and uprights are provided between adjacent units to be common thereto. In this transfer press, combination of the modularized units in accordance with the specification of the press enables achieving an improvement in use for various purposes, which is achieved by diversification in need and easiness in modification of specification, cost reduction and an improvement in property of transportation.

In such transfer press, slides in the respective units are also driven substantially at the same time by one main motor common to all the units. Also, provided in transfer press are a set of a flywheel rotated constantly by a main motor, a clutch for intermittently transmitting energy of the flywheel to the respective slides, and a brake for stoppage of movements of the slides, in addition to the main motor.

In the above-mentioned transfer press, however, all the slides are driven at the same time by one main motor, so that the main motor is made large in size and the flywheel, clutch and the brake are also made large in size. Accordingly, there is caused a problem that purchasing of these parts involves much labor and high cost, for example, production is impeded because the transfer press cannot but be stopped for a long period of time in the case where these parts must be exchanged in a transfer press actually in use.

Also, since all the slides in the transfer press are driven substantially at the same time without phase difference, restrictions are imposed on manufacture of metallic molds and configuration of workpieces, thus causing a problem that various workings cannot be accommodated.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a transfer press, in which it is possible to reduce the size of drive means for driving slides and to realize various workings, and a method of driving slides thereof.

A transfer press according to a first aspect of the invention is provided with a plurality of slides, and comprises slide drives being drive sources provided every slide, and control means for controlling the slide drives to synchronously drive and/or singly drive the slides individually.

In the transfer press provided with a plurality of slides, according to the first aspect of the invention, the slide drives containing drive sources are provided every slide, and so the drive source suffices to drive one slide and has no need of so large capacity as that in the prior art, by which considerably small-sized drive sources used for various purposes can be used to reduce labor and cost required for purchasing.

Also, the respective slides are driven in various modes by controlling the slide drives provided every slide.

For example, in addition to the case where the respective slides are driven at the same time as in the prior art (synchronously drive without phase difference), the slides can be synchronously driven with optional phase difference, or stopped a predetermined time every cycle at a top dead point, or singly driven individually. Accordingly, one press can perform working in a tandem press and a single press as well as working of a transfer press, whereby various workings can be accommodated. The above-mentioned object can be attained as described above.

A transfer press according to a second aspect of the invention is one, in which a plurality of units each composed of a crown, a slide and a bed are arranged along a workpiece transfer direction and uprights are provided between adjacent units to be common thereto, and which comprises slide drives being drive sources provided every slide; and control means for controlling the slide drives to synchronously drive and/or singly drive the slides individually.

According to the second aspect of the invention, the slide drives are provided every unit, and so the drive source constituting the slide drive suffices to drive a slide in one unit, by which considerably small-sized drive sources used for various purposes can be used to reduce labor and cost required for purchasing as described with respect to the first aspect of the invention.

Also, control of the slide drives with the control means enables the slides to be synchronously driven with optional phase difference, or stopped a predetermined time every cycle at a top dead point, or singly driven individually, in addition to the case where the slides provided every unit are driven at the same time as in the prior art (synchronously drive without phase difference). Accordingly, by driving the slides with phase differences, which are conformed to levels, at which workpieces are worked, dimensions of metallic molds or the like, or singly driving the slides, one press can achieve working in a tandem press and a single press as well as working of a transfer press, whereby various workings can be accommodated. The above-mentioned object can be attained as described above.

A method of driving slides of a transfer press provided with a plurality of slides, according to a third aspect of the invention, comprises the steps of driving the slides by means of drive sources provided every slide, and controlling slide drives, which include the drive sources, to synchronously drive and/or singly drive the slides individually.

The third aspect of the invention provides a slide driving method that can be realized by means of the transfer press of the first aspect of the invention, and therefore attains the object of the invention as described with respect to the first aspect of the invention. In addition, included in the invention are the case where all the plurality of slides are synchronously driven without phase difference, the case where all the plurality of slides are synchronously driven with predetermined phase differences, the case where all the plurality of slides are singly driven, and the case where synchronous drive without phase difference, synchronous drive with phase difference, synchronous drive, in which the slides are stopped a predetermined time every cycle at a top dead point, and single drive are combined optionally, the single drive including the case where the slides are maintained in stoppage.

A method of driving slides of a transfer press, in which a plurality of units each composed of a crown, a slide and a bed are arranged along a workpiece transfer direction and uprights are provided between adjacent units to be common thereto, according to the third aspect of the invention, comprises the steps of driving the slides by means of drive sources provided every slide, and controlling slide drives, which include the drive sources, to synchronously drive and/or singly drive the slides individually.

The fourth aspect of the invention of provides a slide driving method that can be realized by means of the transfer press of the second aspect of the invention, and therefore attains the object of the invention as described with respect to the second aspect of the invention of. In addition, included in the invention are the case where all the plurality of slides are synchronously driven without phase difference, the case where all the plurality of slides are synchronously driven with predetermined phase differences, the case where all the plurality of slides are singly driven, and the case where synchronous drive without phase difference, synchronous drive with phase difference, synchronous drive, in which the slides are stopped a predetermined time every cycle at a top dead point, and single drive are combined optionally, the single drive including the case where the slides are maintained in stoppage.

A method of driving slides of a transfer press, according to the fifth aspect of the invention, is one according to the third or fourth aspect of the invention, wherein when at least a pair of slides are to be synchronously driven, the slide drives are controlled so that at least a slide is synchronously driven while stopping a predetermined time every cycle at a top dead point.

In such method, it is possible to make a transfer press function as a tandem press, and since idle stations are not necessarily required between the working stations, a space for installation is small and productivity is high.

A method of driving slides of a transfer press, according to a sixth and seventh aspect the invention, is one according to any one of the third through fifth aspects of the invention, where in the case where at least a pair of slides are to be synchronously driven, the slide drives are controlled so that the slides are synchronously driven with phase difference.

In such method, in the case where one slide is driven earlier in phase than the other slides, the one slide has been terminated in working to be returned to a higher level when working in the other slides is terminated. Accordingly, even a workpiece having a larger height of working can be surely transferred in the working station, in which the one slide is present, without interference between the workpiece and a metallic mold.

Also, when phase difference is optionally set in all the units, the transfer press will function as a tandem press, and use of the press for various purposes is surely promoted.

A method of driving slides of a transfer press, according to the invention of any one of seventh through eleventh aspects of the invention, is one according to any one of the third through sixth aspects of the invention, wherein other slides are driven in a state, in which any one slide is stopped.

Such method makes it possible for a transfer press to function as a single press, and stoppage of slides not in use reduces load, for which the slides must be driven, and energy consumption in the slide drives to lead to economy.

A method of driving slides of a transfer press, according to the invention of any one of the 12th through 15th aspects of the invention is one according to any one of the third through seventh aspects of the invention, wherein other slides are driven in a state, in which any one slide is stopped and the drive source therefor is stopped.

A slide can be maintained in stoppage by releasing a clutch so as to prevent energy of a rotating flywheel from being transmitted to the slide side and causing a brake to hold the slide, in which case energy for rotating the flywheel with the use of a drive source is consumed to lead to want of economy.

In contrast, the invention is economical because the drive source is also stopped to eliminate wasteful energy consumption.

Respective embodiments of the invention will be described below with reference to the drawings.

In addition, the same constituent members in second to fourth embodiments described later as those in a first embodiment and constituent members having the same function in the second to fourth embodiments as that of the constituent members in the first embodiment are denoted by the same characters as those in the first embodiment, and an explanation therefor is omitted.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1

is a general, perspective view showing a transfer press according to a first embodiment of the invention schematically;

FIG. 2

is a front view showing the transfer press of the first embodiment and an operating configuration of a transfer feeder;

FIG. 3

is a front view showing the transfer press of the first embodiment and another operating configuration of the transfer feeder;

FIG. 4

is a plan view showing the transfer press of the first embodiment;

FIG. 5

is a side elevational view showing the transfer press of the first embodiment;

FIG. 6

is a perspective view showing an essential part of the transfer feeder of the first embodiment as viewed from below;

FIG. 7

is a front view showing a transfer press according to a second embodiment of the invention;

FIG. 8

is a plan view showing the transfer press of the second embodiment;

FIG. 9

is a perspective view showing an essential part of the transfer feeder used in the second embodiment as viewed from below;

FIG. 10

is a plan view showing an offset device used in a third embodiment;

FIG. 11

is a side elevational view showing the offset device of the third embodiment;

FIG. 12

is a front view showing a modification of the invention;

FIG. 13

is a plan view showing the above modification;

FIG. 14

is a front view showing a transfer press according to a fourth embodiment of the invention; and

FIG. 15

is a plan view showing the transfer press of the fourth embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[First Embodiment]

FIG. 1

is a general, perspective view schematically showing a transfer press

1

according to the first embodiment of the invention.

FIGS. 2 and 3

are front views showing the transfer press

1

and different operating conditions of a transfer feeder.

FIGS. 4 and 5

are a plan view and a side view showing the transfer press

1

.

FIG. 6

is a perspective view of an essential part of the transfer feeder as viewed from below.

First, the transfer press

1

will be described below in detail.

In

FIGS. 1

to

5

, the transfer press

1

comprises a plurality (four in this embodiment) of modularized press units

2

arranged in a workpiece transfer direction, and is provided with working stations W

1

to W

4

, which correspond to the respective press units

2

.

Mounted on the transfer press

1

are a stacker device for workpiece feeding (not shown) and a transfer feeder

10

described later as well as a controller

3

(

FIG. 1

) as control means composed of a control panel and an operating panel. In such transfer press

1

, a workpiece

11

is transferred toward a right side from a left side in the drawings (an upstream side in the left side and a downstream side in the right side in the drawings).

The respective press units

2

constituting the transfer press

1

comprises a set composed of a crown

4

, in which a drive force transmitting mechanism such as a crank mechanism, an eccentric mechanism or a crank mechanism is housed, a slide

5

connected to the drive force transmitting mechanism in the crown

4

and mounting thereon an upper mold, and a bed

6

, in which a moving bolster

6

A mounting thereon a lower mold can be received. However, an ordinary bolster fixed to the bed

6

is in some cases used instead of the moving bolster

6

A. Also, illustration of metallic molds is omitted in the respective figures.

Two uprights

7

common to the respective press units

2

are provided upright between adjacent press units

2

to be opposed to each other in a direction perpendicular to the workpiece transfer direction as viewed in a plan view. Tie rods

8

extend vertically through the uprights

7

, and are used to connect together the crown

4

, bed

6

and the uprights

7

in a press unit

2

. Adjacent press units

2

are connected to each other by clamping of tie bolts (not shown) in the workpiece transfer direction. Vertically openable, protective fences

9

(

FIG. 5

) are provided between the uprights

7

.

In addition, these uprights

7

and tie rods

8

are provided two to upstream and downstream ends in the workpiece transfer direction as shown in the figure.

As shown in

FIGS. 1 and 5

, the slide

5

in the respective press units

2

is driven by a slide drive

20

(not shown in

FIGS. 2 and 3

) provided every press unit

2

.

The slide drive

20

is composed of a main motor

21

as a drive source, a flywheel

22

rotated by the main motor

21

, a clutch (not shown) for intermittently transmitting rotational energy of the flywheel

22

to the drive force transmitting mechanism in the crown

4

, and a brake

23

for stopping movements (slide motion) of the slide

5

, the slide drive being arranged on, for example, an upper portion of the crown

4

.

These main motor

21

, flywheel

22

, clutch, and the brake

23

are considerably small in size as compared with the prior arrangement, in which all slides are driven together and a lengthy, large-scale transfer bars are driven, and smaller in drive force consumption even when a lift shaft servomotor

14

and a linear motor

16

are added to them.

The controller

3

serves to control slide drives

20

of the press units

2

for driving of the slides

5

, and comprises W

1

to W

4

control means

3

A to

3

D for individually controlling the slide drive

20

every press unit

2

, and overall control means

3

E for controlling these W

1

to W

4

control means

3

A to

3

D overall, the controller being fabricated by the control technique making use of a computer.

Each of W

1

to W

4

control means

3

A to

3

D has the function equivalent to that of control means in general single presses, and controls the slide drive

20

of a corresponding one of the working stations W

1

to W

4

irrespective of other slide drives

20

to drive the slide

5

singly.

The overall control means

3

E functions to controllingly link two or more control means (

3

A to

3

D) optionally selected from W

1

to W

4

control means

3

A to

3

D together, and controls the slide drives

20

of the working stations (W

1

to W

4

) corresponding to the selected control means (

3

A to

3

D) to synchronously drive the respective slides

5

without phase difference or under different conditions.

Accordingly, such controller

3

enables <1> control for synchronously driving the slides

5

in all the working stations W

1

to W

4

without phase difference (synchronous drive mode without phase difference), <2> control for optionally setting drive conditions of the slides

5

in all the working stations W

1

to W

4

to synchronously drive the slides together (synchronous drive mode under different conditions), <3> control for singly driving the slides

5

in all the working stations W

1

to W

4

(single drive mode), and <4> control (multi-drive mode), in which synchronous drive without phase difference, synchronous drive under different conditions and single drive are combined optionally, and the W

1

to W

4

control means

3

A to

3

D enable maintaining the slides

5

in stoppage when the slides

5

are driven singly.

And in the controller

3

, any one of the drive modes is selected by way of the operating panel or the like to start up the control means (

3

A to

3

E) conformed to a selected drive mode to control the operation of the transfer press

1

. Also, the controller

3

is provided with T

1

to T

4

control means

3

F to

3

I for controlling the transfer feeder

10

.

The transfer feeder

10

will be described below in detail.

The transfer feeder

10

transfers workpieces

11

, which having been worked in the respective working stations W

1

to W

4

, to a downstream side in transfer areas T

1

to T

4

set between centers of the respective working stations W

1

to W

4

, the transfer feeder being composed of four feed units

12

arranged in the respective transfer areas T

1

to T

4

.

The feed units

12

comprise a pair of lift beams

13

(correspond to conventional transfer bars but the transfer bars themselves in the invention do not have the transfer function but only the lift function, and so they will be called hereinbelow “lift beams”) arranged in parallel along the workpiece transfer direction and spaced horizontally from each other not to interfere with slide motions, lift shaft servomotors

14

for driving the lift beams

13

vertically, carriers

15

mounted on the respective lift beams

13

, linear motors

16

(

FIG. 6

) for moving the carriers

15

lengthwise of the lift beams

13

, a cross bar

17

bridging transversely between the carriers

15

, and a vacuum cup device

18

mounted on the cross bar

17

, the vacuum cup device

18

being constructed to attract a workpiece

11

at several (four in the embodiment) locations.

The lift beams

13

have a small length corresponding to about a half of a conventional transfer bar so that proximate portions thereof in the workpiece transfer direction are disposed every one of the respective transfer areas T

1

to T

4

.

Concretely, the lift beams

13

are somewhat longer than a length (length in the workpiece transfer direction) of the transfer areas T

1

to T

4

, and disposed such that portions having substantially the same length extend beyond the transfer areas T

1

to T

4

toward upstream and downstream sides.

Also, as shown in

FIG. 4

, the lift beams

13

in the transfer areas T

2

and T

4

are disposed inside the lift beams

13

in the transfer areas T

1

and T

3

, so that as viewed in plan view, ends of the lift beams

13

adjacent to each other in the workpiece transfer direction are opposite to one another in positions (shown by alternate long and short dash lines in the figure) corresponding to centers of the working stations W

1

to W

4

and in a direction (up and down direction in

FIG. 4

) perpendicular to the workpiece transfer direction.

Provided on undersides of such lift beams

13

are longitudinally continuous, horizontal flange-shaped guides

131

as shown in FIG.

6

.

The lift shaft servomotors

14

are supported through support members

141

by the uprights

7

, and used to rotate pinions (not shown) whereby vertical rods

142

formed with racks adapted to mesh with the pinions are moved up and down to move the lift beams

13

vertically. Timing of start-up and rotational speed of the servomotors

14

are preset with the use of a suitable input means provided on the operating panel or the like and controlled by the controller

3

.

In addition, while one lift beam

13

is moved vertically by two servomotors

14

, one or three servomotors

14

may serve provided that the arrangement is able to move the lift beam

13

vertically in a natural and stable position, and the number of servomotors

14

and a connecting structure of the servomotors and the lift beams

13

may be determined optionally when put to practical use.

The linear motors

16

comprise a carrier-side constituent portion

16

A and a lift beam-side constituent portion

16

B as shown in FIG.

6

. The carrier-side constituent portion

16

A engages with and moves on the guide

131

of the lift beam

13

, timing and speed of movement thereof being preset and controlled by the controller

3

. With such linear motors

16

, a primary coil is provided on the carrier-side constituent portion

16

A and a secondary conductor or secondary permanent magnet is provided on the lift beam-side constituent portion

16

B on the underside of the lift beam

13

to be opposite to the primary coil.

In addition, the primary coil may be provided on the lift beam-side constituent portion

16

B and the secondary conductor or secondary permanent magnet may be provided on the carrier-side constituent portion

16

A to be opposite to the primary coil.

The carrier

15

is mounted integrally on the underside of the carrier-side constituent portion

16

A of the linear motor

16

to move together with the carrier-side constituent portion

16

A.

The cross bar

17

and the vacuum cup device

18

mounted thereon are the same as those used for conventional transfer feeders and have a suitable rigidity and forces (attracting) for surely holding a workpiece.

Referring now to

FIG. 1

, the T

1

to T

4

control means

3

F to

3

I on the controller

3

function to control the servomotors

14

and the linear motors

16

in the transfer areas T

1

to T

4

and to individually drive the lift beams

13

and the carriers

15

every one of the respective transfer areas T

1

to T

4

under drive conditions composed of a predetermined timing of drive, driving speed, drive amount (quantity of lift, quantity of feed).

And the T

1

to T

4

control means

3

F to

3

I also provide for mutual control between the servomotors

14

and the linear motors

16

every one of the respective transfer areas T

1

to T

4

so that movements of the lift beams

13

are linked with movements of the carriers

15

.

Also, the overall control means

3

E of the controller

3

functions to controllingly link two or more control means (

3

F to

3

I) optionally selected from the T

1

to T

4

control means

3

F to

3

I together, and controls the servomotors

14

and the linear motors

16

corresponding to the selected control means (

3

F to

3

I) to synchronously drive the respective servomotors

14

and the linear motors

16

between the transfer areas T

1

to T

4

without phase difference or under optionally selected drive conditions.

Further, the overall control means

3

E can controllingly link the W

1

to W

4

control means

3

A to

3

D and the T

1

to T

4

control means

3

F to

3

I together, and links slide motions in the working stations W

1

to W

4

with movements of the lift beams

13

and the carriers

15

in the transfer areas T

1

to T

4

.

Accordingly, such controller

3

enables <1> control for synchronously driving the lift beams

13

and the carriers

15

in all the transfer areas T

1

to T

4

without phase difference and under the same drive conditions such as timing of drive, driving speed, drive amount (synchronous drive mode without phase difference), <2> control for optionally setting drive conditions of the lift beams

13

and the carriers

15

in all the transfer areas T

1

to T

4

to synchronously drive them together (synchronous drive mode under different conditions), <3> control for optionally setting drive conditions and singly driving all the lift beams

13

and the carriers

15

every one of the transfer areas T

1

to T

4

(single drive mode), and <4> control (multi-drive mode), in which synchronous drive without phase difference, synchronous drive under different conditions and single drive are combined optionally, and when single drive is effected by the T

1

to T

4

control means

3

F to

3

I, the lift beams

13

and the carriers

15

can be maintained in stoppage state.

And in the controller

3

, any one of the drive modes is selected by way of the operating panel or the like to start up the control means (

3

E to

3

I) conformed to a selected drive mode to control the operation of the transfer feeder

10

.

Here, an explanation will be given to a typical method of transferring workpieces

11

with the transfer feeder

10

constructed in the above manner.

First, when working in the working station W

1

is terminated in the transfer area T

1

and the slide

5

turns to rise, the carriers

15

on the lift beams

13

disposed at a predetermined level are moved along the lift beams

13

to reach ends on the side of the working station W

1

(refer to the carriers

15

A and the cross bar

17

A shown by two-dot chain lines in

FIGS. 2

,

3

and

4

), and the vacuum cup device

18

is positioned on a center of the working station W

1

, in which position the lift beams

13

are lowered to afford attracting the workpiece

11

.

Subsequently, the lift beams

13

are raised, the carriers

15

are moved to ends on the side of the working station W

2

(refer to the carriers

15

B and the cross bar

17

B shown by two-dot chain lines in FIG.

4

), and the vacuum cup device

18

is positioned on a center of the working station W

2

, in which position the lift beams

13

are lowered to afford releasing the workpiece

11

. Subsequently, before the slide

5

in the working station W

2

is fully lowered, that is, before working in the working station W

2

is started, the lift beams

13

are raised and the carriers

15

are returned to approximately a center of the transfer area T

1

not to interfere with the slide

5

and metallic molds.

Subsequently, when working in the working station W

2

is terminated, the lift beams

13

and the carriers

15

in the transfer area T

2

are also driven in the same manner as the feed unit

12

in the transfer area T

1

.

And carrying-in and carrying-out are made in all the transfer areas T

1

to T

4

by driving the feed units

12

also in the transfer areas T

3

and T

4

in the same manner, and finally the workpiece is forwarded to a carrying-out device (not shown) from the transfer area T

4

.

In addition, actually, movements of the carriers

15

are not made in a state, in which the lift beams

13

are standstill, but are made while the lift beams

13

are moved up and down. Thereby, efficient transfer is enabled to increase the working speed.

Typical configurations among the operating configurations of the transfer press

1

and the transfer feeder

10

will be described below together with the drive modes. Operating configuration A (both the transfer press and the transfer feeder are operated in “synchronous drive mode without phase difference”)

In this operation, the slides

5

, lift beams

13

and the carriers

15

are synchronously driven between all the press units

2

and the feed units

12

without phase difference, and the transfer press

1

and the transfer feeder

10

are operated in the same manner as in the prior art.

More specifically, the slides

5

are synchronously driven without phase difference therebetween in all the working stations W

1

to W

4

to apply working to the workpieces

11

substantially at the same time. Immediately after working of the workpieces

11

is terminated and the respective slides

5

turns to rise substantially at the same time, the lift beams

13

and the carriers

15

in the transfer feeder

10

are also synchronously driven without phase difference therebetween and at the same driving speed and drive amount in all the transfer areas T

1

to T

4

to forward the workpieces

11

all together to next steps.

At this time, all the W

1

to W

4

control means

3

A to

3

D and the T

1

to T

4

control means

3

F to

3

I are started up in the controller

3

, and the overall control means

3

E controllingly links all these control means

3

A to

3

D,

3

F to

3

I together.

Such operating configuration A is implemented by selecting drive modes of both of the transfer press

1

and the transfer feeder

10

as “synchronous drive mode without phase difference” in the operating panel of the controller

3

. Operating configuration B (the transfer press: “synchronous drive mode without phase difference”, the transfer feeder: “synchronous drive mode under different conditions”)

In this operation, the transfer press

1

is operated in the same manner as in the prior art, and the transfer feeder

10

is operated in the same manner as in a transfer device in a tandem press line. The manner in such operating configuration is shown in FIG.

2

.

In

FIG. 2

, the slides

5

in all the working stations W

1

to W

4

of the transfer press

1

are synchronously driven without phase difference therebetween.

Meanwhile, the lift beams

13

and the carriers

15

in the transfer feeder

10

are synchronously driven at the same driving speed and drive amount in the transfer areas T

1

, T

2

. In contrast, carrying-out from the working station W

3

is made in the transfer area T

3

under the same driving conditions as those in the transfer areas T

1

, T

2

, and carrying-in into the working station W

4

is made under driving conditions with driving speed and drive amount different from those in the transfer areas T

1

, T

2

. Also, carrying-out from the working station W

4

is made in the transfer area T

4

under driving conditions with driving speed and drive amount different from those in the transfer areas T

1

, T

2

, and discharge to a discharge device (not shown) is made under the same driving conditions as those in the transfer areas T

1

, T

2

.

With such operating configuration in the transfer areas T

1

, T

2

, when working of all the workpieces

11

is terminated substantially at the same time and the slides

5

turns to rise, the lift beams

13

and the carriers

15

are simultaneously driven to begin carrying-out.

However, for example, in the case where the metallic mold in the working station W

4

is somewhat larger in size than those in the other working stations W

1

to W

3

, a workpiece

11

in the transfer area T

3

is discharged from the working station W

3

at the same timing as that in the transfer areas T

1

, T

2

. After such discharge, the lift beams

13

and the carriers

15

in the transfer area T

3

are once stopped in positions, where there is no interference between the metallic mold and the workpiece

11

, or driven at low speed taking account of interference to delay carrying-in of the workpiece

11

into the working station W

4

until the slide

5

in the working station W

4

becomes adequately high in level.

Meanwhile, the operation in the transfer area T

4

is such that until the slide

5

becomes adequately high in level, the lift beams

13

and the carriers

15

are once stopped or driven at low speed so as to avoid interference to delay carrying-out of a workpiece

11

from the working station W

4

, and after being discharged, the workpiece

11

is carried onto a discharge device (not shown) at the same timing as that in the transfer areas T

1

, T

2

.

Thereby, even if the metallic mold in the working station W

4

is somewhat large in size, transfer of the workpiece

11

is smoothly performed without interference with the metallic mold.

In addition, after the slides

5

in the transfer areas T

3

, T

4

have become adequately high in level, the lift beams

13

and the carriers

15

may be driven at higher speed in that motion, in which acceleration applied on the vacuum cup devices

18

is restricted, whereby it is possible to complete carrying-in and carrying-out of workpieces

11

in all the transfer areas T

1

to T

4

substantially at the same time and to instantaneously drive all the slides

5

for subsequent working.

Also, in the case where metallic molds in any one of the remaining working stations as well as in the working station W

4

are large in size, transfer of workpieces

11

can be smoothly performed by way of the same control as that described above.

At this time, all the W

1

to W

4

control means

3

A to

3

D and the T

1

to T

4

control means

3

F to

3

I are also started up in the controller

3

, and the overall control means

3

E controllingly links all these control means

3

A to

3

D,

3

F to

3

I together.

However, the operating panel of the controller

3

is used to select“synchronous drive mode without phase difference” as the drive mode of the transfer press

1

, “synchronous drive mode under different conditions” as the drive mode of the transfer feeder

10

, and which of the lift beams

13

and the carriers

15

should be made different in drive conditions. Operating configuration C (the transfer press: “synchronous drive mode under different conditions”, the transfer feeder: “synchronous drive mode without phase difference”)

In this operation, a part or all of the transfer press

1

is operated in the same manner as a tandem press, and the transfer feeder

10

is operated in the same manner as in the prior art. The manner in such operating configuration is shown in FIG.

3

.

First, synchronous driving of the respective slides

5

with an optional phase difference, among the configurations of driving under different conditions, will be described.

In

FIG. 3

, the slide

5

in the working station W

4

is synchronously driven an amount of preset phase difference earlier than the slides

5

in the working stations W

1

to W

3

in the transfer press

1

. At this time, the slides

5

in the other working stations W

1

to W

3

are synchronously driven without phase difference therebetween.

Meanwhile, the transfer feeder

10

is operated such that the lift beams

13

and the carriers

15

in all the transfer areas T

1

to T

4

are synchronously driven without phase difference and under the same driving condition.

In such operating configuration, the slide

5

in the working station W

4

is first lowered, and subsequently the respective slides

5

in the working stations W

1

to W

3

are lowered all together. Thereafter, when working of the workpieces

11

in the working stations W

1

to W

3

is terminated and the slides

5

turns to rise, all the lift beams

13

and the carriers

15

are driven all together to begin transfer.

Thereby, in the transfer area T

4

, the slide

5

in the working station W

4

is positioned higher than the slides

5

in the working stations W

1

to W

3

when the lift beams

13

and the carriers

15

are driven for attraction of a workpiece

11

, whereby a workpiece

11

is smoothly carried out without interference with a metallic mold or the like even when working, for example, deep drawing is applied so that the workpiece

11

subjected to working in the working station W

4

will have a large height (vertical dimension).

In addition, in the case where the workpiece

11

in any one of the remaining working stations as well as in the working station W

4

has a large height, transfer of the workpieces

11

can be smoothly performed by way of the same control as that described above.

Subsequently, stoppage at top dead point every cycle, among the configurations of driving of the respective slides

5

under different conditions, will be described.

For example, it is assumed that deep drawing is effected in the working station W

1

. It is required in the working station W

1

that the slide

5

be driven at low speed so as not to cause crack in a workpiece

11

. However, it is required in the other working stations W

2

to W

4

that the slides

5

be rapidly raised in order to facilitate transfer of workpieces. Also, it is necessary to make cycle time consistent in the both cases. Therefore, after the slides

5

in the working stations W

2

to W

4

are more rapidly driven than in the working station W

1

, they are stopped at top dead points to make cycle time consistent with that in the working station W

1

.

Thereby, mold design is made easy to enhance working accuracy relative to productivity, and reduction in mold service life, due to the enhanced productivity, can be suppressed.

In such operation, the overall control means

3

E controllingly links the W

1

to W

4

control means

3

A to

3

D and the T

1

to T

4

control means

3

F to

3

I together, and the operating panel of the controller

3

is used to select “synchronous drive mode under different conditions” as the drive mode of the transfer press

1

, and to select which of the slides

5

should cause phase shift and “synchronous drive mode without phase difference” as the drive mode of the transfer feeder

10

. Operating configuration D (both the transfer press and the transfer feeder are operated in “single drive mode”)

In this operation, any one slide or slides

5

, lift beams

13

and carriers

15

as selected are singly driven, for example, the slides

5

, lift beams

13

and the carriers

15

are driven only in the working station W

1

and in the transfer area T

1

, and all the operations in the other working stations W

2

to W

4

and in the transfer areas T

2

to T

4

are stopped.

In this configuration, one press unit

2

and one feed unit

12

form a single press (line).

In this case, the same working as in a single press is performed in the working station W

1

as driven, and, for example, the working station W

2

on a downstream side is used as a station where workpieces

11

having been subjected to working are stacked. Then drive conditions for the lift beams

13

and the carriers

15

are set so that interference between the workpieces

11

and metallic molds is avoided and the workpieces

11

having been subjected to working can be stacked.

And the main motors

21

of the slide drives

20

themselves are stopped in the press units

2

in the working stations W

2

to W

4

as stopped, and the flywheels

22

are also not rotated, which achieves energy saving.

In addition, as slides

5

to be driven one or two or more slides

5

may be driven individually. Also, in the case where a plurality of slides are to be driven, the adjacent slides

5

may be driven or the spaced slides

5

may be driven.

Further, the transfer feeder

10

may be operated such that the lift beams

13

and the carriers

15

in the transfer areas T

1

to T

4

in positions corresponding to the slides

5

to be driven are driven. For example, in the case of driving only one slide

5

, the lift beams

13

and the carriers

15

may be driven in all the transfer areas T

1

to T

4

, so that after a workpiece

11

is carried into the transfer press

1

from a stacking device disposed on a most upstream side and subjected to working at an optional location, the workpiece

11

can be discharged by a carrying-out device disposed on a most downstream side.

In the controller

3

, the W

1

, T

1

control means

3

A,

3

F corresponding to the working station W

1

and the transfer area T

1

are started up and the overall control means

3

E is started up to link the former control means, but the other W

2

to W

4

, T

2

to T

4

control means

3

B to

3

D,

3

G to

3

I are not started up.

The operating panel of the controller

3

is used to select “single drive mode” as the drive mode of both the transfer press

1

and the transfer feeder

10

, and which of the slides

5

, the lift beams

13

and the carriers

15

should be driven.

The present embodiment provides the following effects:

(1) The transfer press

1

provides the main motors

21

every press unit

2

, and so the main motors

21

can be made markedly small in size as compared with a prior main motor

21

, which is used to drive all slides

5

. Also, by virtue of the main motors

21

being made small in size, the flywheel

22

, clutch and the brake

23

, which constitute the slide drive

20

, can be small in size as compared with the prior art.

Accordingly, these parts constituting the slide drive

20

are further usable for various purposes, and so can be purchased quickly and inexpensively. Further, spare parts for such parts can be easily stocked in factories or the like, and production can be prevented from being crippled because rapid countermeasures are taken without stopping the production line over a long term in the case where replacement is needed due to failure or the like.

(2) Also, since the transfer press

1

can be operated in many configurations such as the operating configurations A to D by controlling the main motors

21

of the respective press units

2

with the respective control means

3

A to

3

I of the controller

3

, it can accommodate various workings such that it serves partly as a tandem press to accommodate deep drawing in addition to conventional transfer working and functions as a single press.

(3) The lift beams

13

and the carriers

15

in the transfer areas T

1

to T

4

can be driven under optional drive conditions by using the respective control means

3

A to

3

I of the controller

3

to control not only the respective slides

5

in the transfer press

1

but also the servomotors

14

and the linear motors

16

in the transfer feeder

10

. Accordingly, the lift beams

13

and the carriers

15

can be always driven in a state of avoiding interference with metallic molds, by virtue of being controlled in accordance with the metallic molds used in the working stations W

1

to W

4

, so that conventional restrictions on metallic molds are mitigated to enable providing great freedom in mold design.

(4) Also, owing to mitigation of restrictions on metallic molds, even metallic molds used in conventional tandem presses and single presses can be applied for other uses without substantial reconstruction, and so labor and cost for fabricating new metallic molds can be reduced.

(5) The transfer press

1

and the transfer feeder

10

can be operated in a conventional manner by synchronously driving the slides

5

, lift beams

13

and the carriers

15

in all in the working stations W

1

to W

4

and the transfer areas T

1

to T

4

without phase difference, as in the above-mentioned operating configuration A.

(6) Even in the case of using somewhat large-sized metallic molds, carrying-in and carrying-out of workpieces

11

can be terminated in the transfer areas T

1

to T

4

at the same timing to keep transfer efficiency favorable when the lift beams

13

and the carriers

15

are shifted in timings of start-up and stoppage and driven at high speed in motions, by which acceleration applied on the vacuum cup devices

18

is suppressed, as described in the operating configuration B.

(7) When the slide or slides

5

are driven with advanced phase as in the operating configuration C, working, such as deep drawing or the like, having been conventionally difficult in press units

2

with advanced phase can be realized and workpieces

11

formed thereby can be smoothly carried out even in the case where metallic molds of the same size essential in the transfer press

1

are used and the lift beams

13

and the carriers

15

are driven by original movements of the transfer feeder

10

(synchronously driven at the same driving speed and drive amount and without phase difference). Further, stoppage at top dead points every cycle makes it possible to surely perform working, such as deep drawing or the like, while ensuring productivity.

(8) By performing single driving of all the slides

5

, the lift beams

13

and the carriers

15

as in the operating configuration D, the respective press units

2

and the feed units

12

can be handled as a single press machine and a single feed device, so that even when transfer working is not performed, it is possible to surely accommodate various working provided that metallic molds for a single press machine are set for working and the lift beams

13

and the carriers

15

are driven under drive conditions conformed to sizes of the metallic molds.

(9) Since the transfer feeder

10

adopts shorter lift beams

13

than and in place of conventional, lengthy, large-scaled transfer bars, the small-sized servomotors

14

for moving the lift beams

13

up and down and the linear motors

16

moving along the lift beams

13

suffice to be driven to transfer workpieces

11

, so that all the servomotors

14

and the linear motors

16

combined can reduce power consumption markedly and promote energy saving as compared with the case where conventional transfer bars are driven by a main large motor and a large servomotor.

(10) Since all the main motors

21

can also be made small in size, the above-mentioned servomotors

14

and the linear motors

16

combined can make power consumption markedly smaller than in the prior art, which can promote energy saving further.

(11) Since adjacent portions in the workpiece transfer direction are provided every one of the respective working stations W

1

to W

4

, the lift beams

13

are small in length every one of the respective transfer areas T

1

to T

4

, so that the more small-sized and lightweight the lift beams

13

are, the further the servomotors

14

can be made small-sized.

Since the magnitudes and number of the lift beams

13

, servomotor

14

rods

142

, carriers

15

, linear motors

16

and the vacuum cup device

18

except the cross bar

17

are common to the respective feed units

12

, kinds of members can be reduced to facilitate manufacture of the respective feed units

12

.

Also, since the transfer feeder

10

is composed of the feed units

12

in the respective transfer areas T

1

to T

4

, optimum feed motions can be created every one of the transfer areas T

1

to T

4

to make freedom in mold design considerably great, thus enabling facilitating formation of metallic molds. Further, since it suffices to take account of adjacent transfer areas T

1

to T

4

when feed motions are to be created, acceleration generated on the lift beams

13

can be made to the minimum and the lift beams

13

are made lightweight, which makes it possible for the transfer feeder

10

to surely follow high speed operation of the transfer press

1

.

(12) Since adjacent ends of the lift beams

13

along the workpiece transfer direction face each other in a direction perpendicular to the workpiece transfer direction as viewed in plan view in adjacent transfer areas T

1

to T

4

, the vacuum cup devices

18

on upstream and downstream sides can be made together to get onto central positions of the working stations W

1

to W

4

when the carriers

15

on the respective lift beams

13

are alternately caused to move toward the facing areas. Accordingly, workpieces

11

are mounted and dismounted in the above positions so that transfer can be surely implemented without any special offset devices.

[Second Embodiment]

An explanation will be given to a transfer feeder

10

according to a second embodiment of the invention with reference to

FIGS. 7

,

8

and

9

.

In

FIGS. 7 and 8

, lift beams

13

used in the transfer feeder

10

of the embodiment have a somewhat smaller length than that of transfer areas T

1

to T

4

set at equal pitch (length in a workpiece transfer direction). Also, as shown in

FIG. 8

, adjacent ends of the lift beams

13

along the workpiece transfer direction as viewed in plan view are positioned to correspond to centers of working stations W

1

to W

4

and to face each other in the workpiece transfer direction (right and left direction in

FIG. 4

) in spaced relationship to be disposed on straight lines through the respective transfer areas T

1

to T

4

.

In

FIG. 9

, carrier type offset devices

30

are provided on carriers

15

in the present embodiment.

The carrier type offset devices

30

also serve as the carriers

15

, and comprise a base plate

31

having a predetermined length and provided with a guide groove

31

A along the workpiece transfer direction, a motor

32

provided on an underside of one lengthwise end of the base plate

31

, an encoder

33

provided on an underside of the other lengthwise end of the base plate

31

, a shaft

34

connected at one end thereof to the motor

32

through a coupling

34

A and having the other end thereof supported by the encoder

33

through the coupling

34

A, and a movable block

35

adapted to thread on male threads

34

B formed on an outer surface of the shaft

34

and fitted into the guide groove

31

A of the base plate

31

, to which movable block

35

an end of the cross bar

17

is connected.

In such carrier type offset devices

30

, the motor

32

drives the shaft

34

while the carriers

15

are traveling, so that the movable block

35

threaded on the shaft is caused to slide along the guide groove

31

A.

More specifically, in the respective lift beams

13

, when the carriers

15

are positioned at an upstream side end in the workpiece transfer direction, the movable blocks

35

are also moved toward the upstream side (refer to the carriers

15

A and the cross bar

17

A shown by two-dot chain lines in FIGS.

7

and

8

), and the vacuum cup devices

18

mounted on the cross bars

17

are moved to centers of the working stations W

1

to W

4

.

On the other hand, when the carriers

15

are positioned at a downstream side end, the movable blocks

35

are also moved toward the downstream side (refer to the carriers

15

B and the cross bar

17

B shown by two-dot chain lines in FIGS.

7

and

8

), and the vacuum cup devices

18

mounted on the cross bars

17

are moved to centers of the working stations W

2

to W

4

(a suitable position on a carrying-out device (not shown) in the transfer area T

4

).

Thereby, the vacuum cup devices

18

are made offset in the workpiece transfer direction, and workpieces

11

are mounted and dismounted at the centers of the working stations W

1

to W

4

to be surely transferred.

In addition, control of offset is implemented by virtue of the controller

3

controlling rotational frequency of the motors

32

on the basis of outputs of the encoders

33

.

Then an explanation will be given to operating configurations of a transfer press

1

and the transfer feeder

10

in the present embodiment. Operating configuration E (both the transfer press and the transfer feeder are operated in “synchronous drive mode under different conditions”)

In this operating configuration, the transfer press

1

and the transfer feeder

10

in combination are caused to function in the same manner as in a tandem press line, the manner of this operation being shown in FIG.

7

.

In such operation, the lift beams

13

and the carriers

15

are driven under different drive conditions in accordance with mold sizes in the working stations W

1

to W

4

and vertical dimensions of workpieces

11

after working). And these drive conditions are set so that taking account of relative positions of the slides

5

, interference with metallic molds is eliminated and useless movements are not generated.

At this time, all the W

1

to W

4

control means

3

A to

3

D and the T

1

to T

4

control means

3

F to

3

I are started up in the controller

3

, and the overall control means

3

E controllingly links all these control means

3

A to

3

D,

3

F to

3

I together.

The operating panel of the controller

3

is used to select “synchronous drive mode under different conditions” as the respective drive modes of the transfer press

1

and the transfer feeder

10

.

In addition, while only the operating configuration E has been explained in the present embodiment, the operating configurations A to D in the first embodiment can be of course realized by suitably selecting a drive mode. The present embodiment provides the following effects:

(13) Since the slides

5

are synchronously driven under different conditions and the lift beams

13

and the carriers

15

are driven under optional drive conditions in the present embodiment, the operating configuration E can be implemented, so that the transfer press

1

and the transfer feeder

10

in combination can be caused to function in the same manner as in a tandem press line.

(14) Also, since selection of drive mode makes it possible to implement the operating configurations A to D as in the first embodiment, one transfer press

1

and one transfer feeder

10

enable realizing the original function of a transfer press, the function of a tandem press line and the function of an independent press line, so that it is possible to accommodate various workings.

(15) Since the transfer feeder

10

is constructed such that the lift beams

13

are disposed linearly along the workpiece transfer direction, cross bars having a single kind of length suffice in the present embodiment while the cross bars

17

having two kinds of lengths are necessary in the first embodiment. Thus all the feed units

12

can be made the same in constituent parts, which can dissolve complexity in manufacture.

(16) Also, since the lift beams

13

are disposed on straight lines, widthwise spaces of the transfer areas T

1

to T

4

interposed between pairs of the lift beams

13

can be made larger than those in the first embodiment, so that there is produced margin between the lift beams

13

and metallic molds to facilitate mold design further.

(17) Further, since the carriers

15

mount thereon the carrier type offset devices

30

, workpieces

11

can be mounted and dismounted at centers of the working stations W

1

to W

4

for sure transfer by making the vacuum cup devices

18

offset even if adjacent ends of the lift beams

13

in adjacent transfer areas T

1

to T

4

are opposed to each other in the workpiece transfer direction.

[Third Embodiment]

FIGS. 10 and 11

shown another embodiment of offset devices.

These devices are constituted by crossover type offset devices

40

provided on the cross bars

17

, and comprise a pair of guide members

41

fixed on the cross bar

17

with a spacing in a longitudinal direction thereof, a motor

42

provided on one end side of the cross bar

17

, an encoder

43

provided on the other end side of the cross bar, a shaft

44

connected at one end thereof to the motor

42

through a coupling

44

A and having the other end thereof supported on the encoder

43

through a coupling

44

A, the shaft being rotatably supported by the guide members

41

, pinions

45

provided corresponding to the respective guide members

41

and adapted to rotate together with the shaft

44

, and movable bars

46

inserted between the pinion

45

and the guide members

41

and formed on upper surfaces thereof with a rack

46

A, which mesh with the pinion

45

, and sections of the vacuum cup device

18

are mounted on both lengthwise (workpiece transfer direction) ends of the movable bars

46

.

With such crossover type offset device

40

, the motor

42

on the cross bar

17

rotates the pinions

45

to move the movable bars

46

, which mesh with the pinions

45

, upstream or downstream in the workpiece transfer direction.

Thereby, the sections of the vacuum cup device

18

move to centers of the working stations W

1

to W

4

to be made offset, so that workpieces

11

can be surely mounted and dismounted to be transferred, thus obtaining the above-mentioned effect (

17

) likewise.

In addition, control of offset amount at this time is performed by using the controller

3

to control the rotational frequency of the motor

42

on the basis of output from the encoder

43

.

Also, the following effect is provided by the crossover type offset device

40

:

(18) That is, the provision of the crossover type offset device

40

on the cross bar

17

enables the constitution composed of one motor

42

and one encoder

43

to make the same inexpensive. Also, the use of one motor

42

makes it hard for offset amounts to generate errors, and can make transfer of workpieces

11

favorable because no torsional force acts on the cross bar

17

even if an error generate.

[Fourth Embodiment]

FIG. 14

is a front view showing another transfer press

1

, which is different from that in the first embodiment of the invention.

FIG. 15

is a plan view showing the transfer press

1

.

In

FIGS. 14 and 15

, the transfer press

1

comprises a plurality (five locations) of working stations W

1

to W

5

, and two slides

5

, that is, an upstream-side slide

5

corresponding to the working stations W

1

, W

2

, and a downstream-side slide

5

corresponding to the working stations W

3

to W

5

.

Arranged in the transfer press

1

are a controller

3

(

FIG. 14

) as control means composed of a control panel and an operating panel, a transfer feeder

10

, and a stacking device (not shown) for feeding of workpieces.

Uprights

7

are provided on an upstream side, a substantially middle portion and a downstream side of the transfer press

1

, and areas upstream and downstream of the central upright

7

are referred to as an upstream block and a downstream block, respectively. Also, the transfer press

1

is composed of crowns

4

, in which a drive force transmitting mechanism such as a crank mechanism, an eccentric mechanism or a linkage mechanism is housed every block, slides

5

each provided every block to be connected to the drive force transmitting mechanism in the crown

4

through a plunger

5

A and mounting thereon an upper mold, and beds

6

, in which moving bolsters

6

A every block mounting thereon lower molds can be received. Tie rods

8

extend vertically through the uprights

7

, and are used to connect together the crowns

4

, beds

6

and the uprights

7

.

In addition, metallic molds are omitted in the respective figures. Also, the number of blocks is not two composed of the upstream and downstream block, but may be three or more. Also, the crowns

4

, slides

5

, and beds

6

and the uprights

7

in the respective blocks are not fabricated as a unit, but are uniquely fabricated as parts of the entire transfer press

1

, in which point the constitution is considerably different from that in the first embodiment.

As shown in

FIG. 14

, the slides

5

are driven by slide drives

20

provided every block.

The slide drives

20

comprise a main motor

21

as a drive source, a flywheel

22

rotated by the main motor

21

, a clutch

23

A for intermittently transmitting rotational energy of the flywheel

22

to the drive force transmitting mechanism in the crown

4

, and a brake (not shown) for stopping movements (slide motion) of the slide

5

, the slide drives being arranged on, for example, upper sides of the crowns

4

.

The controller

3

serves to control the slide drives

20

for driving of the slides

5

, and comprises an upstream block control means

3

K and a downstream block control means

3

L, which individually control the slide drives

20

every block, and an overall control means

3

J for controlling these control means overall, the controller being fabricated by the control technique making use of a computer.

Each of the control means

3

K,

3

L in the respective blocks has the function equivalent to that of control means in general single presses, and controls one of the slide drives

20

irrespective of the other of the slide drives

20

to drive the slides

5

singly.

The overall control means

3

J functions to controllingly link the control means

3

K,

3

L, and controls the slide drives

20

in the respective blocks to synchronously drive the respective slides

5

without phase difference or under different conditions.

Accordingly, such controller

3

enables <1> control for synchronously driving the slides

5

in both blocks without phase difference (synchronous drive mode without phase difference), <2> control for optionally setting drive conditions of the slides

5

in the both blocks to synchronously drive the slides together (synchronous drive mode under different conditions), <3> control for singly driving the slides

5

in the both blocks (single drive mode), and <4> control (multi-drive mode), in which synchronous drive without phase difference, synchronous drive under different conditions and single drive are combined optionally, and the control means

3

K,

3

L enable maintaining the slides

5

in stoppage when the slides

5

are driven singly.

And in the controller

3

, any one of the drive modes is selected by way of the operating panel or the like to start up the control means (

3

J to

3

L) conformed to a selected drive mode to control the operation of the transfer press

1

. Also, the controller

3

is provided with T′

1

to T′

6

control means

3

M to

3

R for controlling the transfer feeder

10

. These control means have the same function as those of the T

1

to T

4

control means

3

F to

3

I (FIG.

1

), and such function has been described, so an explanation therefor is omitted here.

According to the present embodiment, the same effect as that described with respect to the first and second embodiments is provided likewise although there is a difference therebetween that the slide drives

20

are provided every one of the working stations W

1

to W

5

(for example,

FIGS. 1 and 7

) or every block. Also, the constitution peculiar to the present embodiment provides the following effect:

(19) Drawing step is in many cases first implemented in press working. Therefore, in many cases, a drive force transmitting mechanism in an upstream block adopts a linkage mechanism and a drive force transmitting mechanism in a downstream block adopts an eccentric mechanism. The linkage mechanism is constructed such that the slides

5

slowly descend and rapidly ascend so as to facilitate deep drawing. Accordingly, when the slides

5

are to descend, they descend to a level below a level required for transfer of workpieces at an early timing, which makes it difficult for transfer of workpieces to be performed in a manner not to interfere with the slides. Hereupon, in the present embodiment, the slides

5

in the respective blocks are driven by separate slide drives

20

in synchronous drive, in which the upstream block is later in phase than the downstream block, whereby transfer of workpieces can be balanced in timing between the upstream block and the downstream block, in which the eccentric mechanism is used.

Also, with the transfer press

1

in the present embodiment, the slide

5

in the downstream block is stopped a predetermined time every cycle at a top dead point whereby transfer of workpieces can be balanced in timing between the downstream block and the upstream block, in which the linkage mechanism is used.

In addition, the invention is not limited to the respective embodiments described above but contains other constitutions capable of attaining the object of the invention and including the following modifications.

For example, while the transfer feeders

10

in the first and second embodiments comprise a pair of lift beams

13

every one of the transfer areas T

1

to T

4

, the transfer feeder according to the invention may include two or more pairs in total, that is, a pair on the upstream side and a pair on the downstream side. Accordingly, while a pair of lift beams

13

are provided in the transfer area T

1

as shown in, for example,

FIGS. 12 and 13

, lift beams extending over a plurality of transfer areas may be used such that a pair of continuous lift beams

13

′ are provided in the transfer areas T

2

to T

4

.

In this case, however, it is desirable to provide every one of the transfer areas T

1

to T

4

a pair of carriers

15

for moving of the vacuum cup device

18

and a cross bar

17

bridging across the carriers in order to perform transfer of workpieces

11

.

Also, other operating configuration for operation of the transfer press

1

and the transfer feeder

10

than the operating configurations A to E described in the respective embodiments are as follows:

More specifically, the transfer press and the transfer feeder, respectively, are operated in “multi-drive mode” such that the slides

5

the working stations W

1

, W

2

and in the transfer areas T

1

, T

2

are operated in “synchronous drive under different conditions” and the lift beams

13

and the carriers

15

are operated in “synchronous drive under different conditions”, whereby the press units

2

and the feed units

12

are caused to function as a tandem press line. Also, all the members are stopped in the working station W

3

and in the transfer area T

3

to be used for stacking of workpieces. Further, the slide

5

, the lift beams

13

and the carriers

15

in the working station W

4

and in the transfer area T

4

are operated in “single drive mode” to function as a single press.

Of course, “synchronous drive without phase difference” may be effected in the working stations W

1

, W

2

and in the transfer areas T

1

, T

2

. In a word, it is optional to implement which drive mode should be implemented in any one of the working stations W

1

to W

4

and the transfer areas T

1

to T

4

.

While in the operating configuration A in the first embodiment all the slides

5

are driven in transfer working, the slides

5

in the working stations W

1

, W

2

, W

4

except the working station W

3

are driven in “synchronous drive without phase difference” and the slide

5

in the working station W

3

is stopped in the case where, for example, the working station W

3

is used as an idle working station even when transfer working is to be performed. And the lift beams

13

and the carriers

15

in all the transfer areas T

1

to T

4

may be driven in “synchronous drive without phase difference”.

Also, while the main motor

21

itself stops in the press unit

2

, in which the slide

5

is not driven, as described in the operating configuration D in the first embodiment, the slide drive method according to claim 4 of the invention covers the case where the main motor

21

and the flywheel

22

are driven and the slide

5

is maintained in stoppage by controlling the clutch and the brake

23

. However, it is desired in terms of energy saving that the main motor

21

itself be stopped.

While the main motors

21

are used as a drive source according to the invention in the respective press units

2

in the above-mentioned embodiments, the respective press units

2

may be constituted as free-motion presses, in which slide motions can be set optionally, by the use of hydraulic cylinders, servomotors or the like as drive sources. And also in this case, various workings can be realized because the slides

5

in the respective press units

2

are synchronously driven with optional phase difference (including the case without phase difference), synchronously driven in optional slide motions or singly driven to thereby make the press units function as a transfer press, tandem press or a single press as a whole.

Number	Name	Date	Kind
3967483	Kuroyahagi et al.	Jul 1976	A
4089205	Mizumoto et al.	May 1978	A
4585389	Watanabe et al.	Apr 1986	A
4770572	Ohkawa et al.	Sep 1988	A
4957019	Kubo	Sep 1990	A
4995255	Noda	Feb 1991	A
5586495	Ogawa et al.	Dec 1996	A
5913932	Takayama	Jun 1999	A
6101861	VanderZee et al.	Aug 2000	A
6520074	Sunata et al.	Feb 2003	B1

Transfer press and method of driving its slides

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

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US

International Classifications

Abstract

Description

Claims

Priority Claims (1)

US Referenced Citations (10)