Method of and Apparatus for Feeding Oil to a Turret Punch Press

The present invention relates to an oil feeder for a machine tool, and more particularly to a method of and an apparatus for feeding cutting oil to a turret punch press.

One well known type of a turret punch press 1 is shown in FIG. 3. This turret punch press 1 comprises an upper rotatable turret 2, a sleeve 5 slidably received in the upper rotatable turret 2, a punch body 4 slidably received in the sleeve 5 and having an upper tool 3 on its lower end which is slidably extendable through a bottom end of the sleeve 5, a lower rotatable turret 6, and a cylindrical die 11 fastened to the lower turret 6 and comprising a lower tool 7. A material A is interposed between the upper and lower turrets 2 and 6 and superposed on the upper face of the lower tool 7. A flange 8 provided on the upper end of the sleeve 5 determines the extent to which the sleeve 5 can be vertically lowered. A compression spring 10 is interposed between the flange 8 and another flange 9 provided on the upper end of the punch body 4, such that the punch body 4 is biased upwardly. In order to effect punching, a striking force is exerted on the upper end face of the punch body 4 by a hammer 12 disposed over the punch body 4, such that the punch body 4 is vertically lowered to such an extent that the upper tool 3 fits in the lower tool 7.

In a turret punch press of this type, the sleeve 5 is in sliding contact with the punch body 4, and the upper turret 2 is in sliding contact with the sleeve 5. Thus, it is conventionally considered necessary to periodically manually feed lubricating oil between these contact surfaces. In addition, it has been necessary to provide cutting oil to the upper tool 3 and the lower tool 7, and in attempting to do so, many difficulties have been encountered. In order to prevent these tools from seizing up on each other, it is most common to apply cutting oil to the surfaces of material A.

In order to feed the lubricating oil more efficiently, it is also common to connect a pressurized air supply source 13 and a pressurized oil supply source 14 to the hammer 12 by means of an oil pipe 15 as shown in FIG. 3. The punch body 4 is provided with a main oil passage 16 and a branch oil passage 17. As can be seen in FIG. 3 the passages 16 and 17 are disposed such that they are effective to feed lubricating oil to the upper tool 3 and the space between the punch body 4 and the sleeve 5. Furthermore, the sleeve 5 is formed with an oil passage 18 extending from the space between the punch body 4 and the sleeve 5 to the space between the sleeve 5 and the upper turret 2 so as to further supply lubricating oil to the space between the sleeve 5 and the upper turret 2.

Although hand lubrication has the advantage of being relatively inexpensive in cost, the disadvantage of hand lubrication is that the labor required therefor is not negligible. Furthermore, one is occasionally so absentminded that he fails to carry out hand lubrication. The automatic lubrication described in the preceding paragraph also has its merits and demerits. Although the automatic lubrication serves to improve the working efficiency, the alterations required to adapt the apparatus for automatic lubrication involve high installation costs. Another disadvantage to the automatic lubrication is that it is impossible to feed both lubricating oil and cutting oil to the proper places at the same time. Still another disadvantage to automatic lubrication is that the products and the equipment are fouled and the work environment is spoiled by pressurized oil splashing out of the apparatus.

Yet still another disadvantage to automatic lubrication is that it is difficult to set the rate of oil flow and the timing of oil outflow in a CAM system, such that the oil feed cannot be smoothly and precisely effected.

Thus, none of the prior art apparatuses is capable of satisfactorily feeding cutting oil to the upper tool and the lower tool. In order to prevent these tools from seizing up on each other, it is common to either make do with lubricating oil in place of cutting oil or to apply cutting oil to the surfaces of the material so that at least a small portion of the cutting oil may be supplied to the cut edges of the material.

The present invention is based on a concept that, in order to improve working efficiency and product quality and make the turret punch press more durable, it is desirable to feed generous streams of the proper kinds of oils to the proper places. It is an object of the present invention, therefore, to provide a method and an apparatus of the general type described above which retains the above-mentioned desirable characteristics. It is another object of the present invention to provide a method and an apparatus by which effective and smooth oil feed can be effected without spoiling the work environment.

To accomplish the above-described objects, a method in accordance with the present invention comprises the steps of fixedly placing, in a prescribed position in a lower turret, a cylindrical die in which a lower tool is formed, providing an upper tool and upper turret to support the upper tool in such a manner as to allow the upper tool to be repeatedly moved vertically, disposing the upper tool over the lower tool so that the upper tool, when vertically lowered, may fit in the lower tool, feeding lubrication oil by a suitable means to the sliding contact surface of the upper tool, positioning a flat material on the upper face of the cylindrical die so as to allow the flat material to mask the lower tool, and feeding atomized cutting oil upwardly from below to a space defined by the flat material and the lower tool.

Further, the present invention relates to an oil feeder for a turret punch press, wherein the turret punch press includes a lower tool member consisting of a lower turret and a cylindrical die which has a lower tool formed in an upper end thereof and which is fastened to the lower turret, and an upper tool member vertically slidably supported by an upper turret and having an upper tool adapted to fit in the lower tool. The oil feeder comprises a lubricating oil feeder means disposed in the vicinity of the contact surfaces at which the upper tool member and a supporting member therefor make sliding contact with one another and a means for feeding atomized cutting oil to the inside space of the cylindrical die.

The contact surfaces at which the upper tool member and the supporting member therefor make sliding contact with one another are fed with lubricating oil suitable for these contact surfaces. A flat material is positioned on the upper face of the cylindrical lower tool member so as to allow the flat material to mask the lower tool member. Suitable cutting oil is fed in an atomized state in the form of upward intermittent spurts from below to a space defined by the flat material and the lower tool member. The flat material masking the lower tool member prevents the cutting oil from splashing to the outside. For the purpose of feeding the upper tool with a generous stream of cutting oil, upward spurts of cutting oil continue to be supplied until the upper tool, after it has been fitted in the lower tool, is moved away from the lower tool.

The above-mentioned and other objects of the present invention are more fully set forth in the following detailed description of a presently preferred embodiment of the present invention, which description is presented with reference to the accompanying drawings.

FIG. 1 is a vertical section illustrating an embodiment of an oil feeder according to the present invention for a turret punch press;

FIG. 2 is a vertical section showing the cooperative relation between an upper tool and a lower tool of the turret punch press; and

FIG. 3 is a vertical section of a conventional turret punch press.

As shown in FIG. 1, the turret punch press per se is in every respect similar to the conventional turret punch press described above with reference to FIG. 3. In the drawings, like numerals are employed to designate like parts throughout the views. A turret punch press 1 includes an upper rotatable turret (upper support element) 2, a sleeve (supporting member) 5 slidably received in a vertical hole formed in the upper turret 2, and a punch body (or upper tool member) 4 vertically slidably received in the sleeve 5. The punch body 4 has an upper tool 3 formed on its lower end, which is slidably extendable through a lower end of the sleeve 5.

A cylindrical die (or lower tool member) 11 having a lower tool 7 on its upper end is fastened to a lower rotatable turret (lower support element) 6. A flange 8 provided on the upper end of the sleeve 5 determines the extent to which the sleeve 5 can be vertically lowered. A compression spring 10 is interposed between the flange 8 and another flange 9 provided on the upper end of the punch body 4, such that the punch body 4 is biased upwardly. In order to effect punching, a striking force is exerted on the upper end face of the punch body 4 by a hammer 12 disposed over the punch body 4, such that the punch body 4 is vertically lowered to such an extent that the upper tool 3 fits in the lower tool 7. A flat material A is disposed between the upper and lower turrets 2 and 6 and is superposed on the upper face of the lower tool 7 so as to allow the flat material A to mask the cylindrical die 11. In use, the upper tool 3 is vertically lowered against the flat material A to such an extent that the upper tool 3 punches a hole in the flat material A and extends into the lower tool 7.

The contact surfaces a at which the sleeve 5 and the punch body 4 make sliding contact with one another, and the contact surfaces b at which the upper turret 2 and the sleeve 5 make sliding contact with one another are fed with lubricating oil suitable for such contact surfaces. For this purpose, it is common to periodically carry out hand lubrication or, alternatively, use an appropriate pressurized oil supply source.

The present invention consists in the provision of an oil pipe 21, an outlet end of which is disposed immediately below an opening in the bottom surface of the cylindrical die 11. The outlet end of the pipe 21 is directed substantially upwardly toward a space defined by the flat material A and the lower tool 7. The oil pipe 21 is connected at its inlet end to a pressurized air supply source 22. A branch line 21' connects between a cutting oil supply source 23 and a bottom of the pipe 21 intermediate the inlet and outlet ends of the pipe 21.

In operation, cutting oil is supplied by the oil pipe 21 from the moment when the flat material A is positioned to mask the cylindrical die 11. The cutting oil from the oil supply source 23 is mixed with air and is fed in an atomized state in the form of upward intermittent spurts from the pressurized air supply source to the interior of the cylindrical die 11, such that it sticks to the lower tool 7. Then the upper tool 3 is vertically lowered against the flat material A to such an extent that the upper tool 3 punches a hole in the flat material A and extends partially into the lower tool 7, while the interior of the cylindrical die 11 continues to be supplied with atomized cutting oil. As a result, a sufficient amount of the cutting oil is also stuck to the upper tool 3. The supply of atomized cutting oil is cut off at the moment when the upper tool 3 moves upwardly away from the lower tool 7. Thus the periodic supply of cutting oil is timed to the masking of the cylindrical die 11 with the material A. With conventional turret punch presses of this type, it has been difficult to punch a hole in an aluminum plate having a thickness of 3 mm. The present invention eliminates this difficulty by the provision of a method and an apparatus constructed and arranged as described herein. Furthermore, any splashing of the cutting oil to the outside is prevented by the flat material masking the cylindrical die.

Thus, in accordance with the present invention, the means for feeding cutting oil to a space defined by the flat material and the lower tool member is a different means than the means for feeding lubrication oil to the contact surfaces at which the upper tool member and the supporting member therefor make sliding contact with one another. Consequently, it is possible to feed a sufficient amount of both lubricating oil and cutting oil to the proper places in a turret punch press.

Before a hole is punched in the flat material, the upper face of the cylindrical die is masked by the flat material. After a hole is punched in the flat material, the cylindrical die is masked by the upper tool extending into the lower tool. Therefore, the cutting oil will not leak through the upper port of the cylindrical die and the work environment will not become spoiled by oil splashing out of the apparatus.