KR101594628B1 - Drop preventing means for ram head attachment of machining center - Google Patents

Abstract

The present invention relates to a machine tool, and more particularly, to a ram head attachment fall preventive device for a machine tool, which comprises means for preventing the attachment from dropping. To this end, a tool for machining a workpiece An attachment 20 having a plurality of stud bolts 28 protruded on an upper surface thereof; And a ram head (30) having a plurality of collets (32) detachably engaged with the respective stud bolts, wherein the ram head attachment preventing fall preventing device (10) A step 130; With the clamp 120 advancing in the direction toward the step 130 when the attachment 20 is engaged with the ram head 30 and with the pin 122 retracting out of the step when the attachment is detached from the ram head The apparatus according to any one of claims 1 to 3, further comprising at least one attachment drop preventing means formed of a pair of the attachment preventing means, It is possible to prevent an operator from being injured or the like.

Attachment, Ram head, Drop, Stud bolt, Collet

Description

[0001] The present invention relates to a ram head attachment preventing device for a machine tool,

The present invention relates to a machine tool, and more particularly to a ram head attachment fall prevention device for a machine tool, which includes means for preventing the attachment from falling when exchanging various types of attachments for machining a workpiece .

A CNC (Computerized Numerical Control) device capable of automatically performing three-dimensional machining by adding functions of a computer to a Numerical Control (NC) device has been developed and is now widely used. Particularly, a device for directly machining a three-dimensional shape by exchanging a plurality of attachments in a manner different from a lathe apparatus for simple machining is also referred to as a so-called double column type machining center.

FIG. 1 shows an example of a commonly used three-dimensional machine tool. 1, a conventional machine tool comprises a ram head 30 to which an attachment is detachably mounted, a ram 40 to which the ram head 30 is mounted at the front end, a ram 40, A saddle 50 for driving the saddle 50 up and down, a cross rail 60 for supporting the saddle 50 movably in the left and right direction, and a pair of columns 70 for supporting the cross rail 60 at both ends thereof And this structure can be appropriately controlled through a control unit 80 that controls the entire machine tool to process a three-dimensional product of a desired shape.

A tool for machining the workpiece is provided in the form of an attachment mounted to the ram head 30, details of the attachment 20 and the ram head 30 are shown in Figs.

2 and 3, the attachment 20 includes a tool 22 for directly machining a workpiece, which is formed at the lower end of the main body 24, and a plurality of stud bolts 28 A fastening portion 26 having a means is formed. For example, the shape of the fastening portion 26 is uniform for all attachments, and the shapes of the tools 22 under the fastening portions 26 are differently applied.

The ram head 30 having a structure for mounting the attachment 20 includes a hydraulic means called a collet 32 as a coupling means. For example, as shown in the figure, the grooves, in which the stud bolts 28 formed on the upper surface 4 of the fastening portion 26 of the attachment 20 are accommodated, are formed on the surface of the ram head corresponding to the fastening portion 26 And a collet 32 capable of holding and fixing the stud bolts 28 hydraulically is formed in the grooves.

An example in which the attachment 20 is mounted to the ram head 30 through the engagement of the stud bolt 28 and the collet 32 is illustrated by way of example in Fig.

4, it can be seen that the collet 32 is formed around the stud bolt 28. As shown in Fig. When the attachment 20 is engaged to be mounted on the ram head 30, the bolt 32 located around the stud bolt 28 is inflated by hydraulic pressure so that the stud bolt 28 slips down to the bottom of the ram head 30 In the case where the bolts are tightly fixed so as not to come off and the bolts are removed for exchanging the attachment, the hydraulic pressure applied to the collet 32 is released so that the stud bolts 28 can freely escape. It is also clear that, in addition to the coupling of the stud bolt 28 and the collet 32, other additional coupling structures may be used, but it is clear that the primary engagement of the attachment mounts is largely dependent on the hydraulic coupling of the stud bolts and collets .

As such, the attachment 20 can be mounted / exchanged to the ram head 30 through a combination of the stud bolt 28 and the collet 32. [

However, the attachment 20 and the ram head 30, which are mounted through such coupling means, have the following problems.

For example, when a problem arises in a hydraulic circuit (for example, a hydraulic pump, a hydraulic conduit, a hydraulic valve, etc.) supplied to the inside of the apparatus in view of the fact that the force for operating the collet 32 is hydraulic pressure, The force of holding the stud bolt 28 is lowered, and the attachment 20 may be detached from the ram head 30 and fall down.

Since the weight of the attachment 30 is usually large, the impact can be greatly increased in proportion to the height of the fall, and the body or the like constituting the attachment is easily damaged. An example of such a damaged body is illustrated in FIG. 5 shows a cylindrical body constituting the main body 24 of the attachment, and a crack is generated in the body by the impact.

Also, unlike the attachment of the attachment to the main body, the fall of the attachment may cause damage to the corresponding portion of the dropping point of the machine tool, or even injury to the operator due to the dropping attachment. Particularly, if the drop of the attachment occurs when the attachment is manually mounted or exchanged, it can be directly connected to the injury of the operator, resulting in a safety problem without cost problems.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a means for preventing the attachment from dropping during attachment / replacement of the attachment.

Further, the present invention is to provide a machine tool capable of easily mounting or exchanging an attachment, even if the attachment fall preventing means is configured.

According to an aspect of the present invention, there is provided a machine tool including a main body having a tool for machining a workpiece, a fastening portion formed on an upper portion of the main body, An attachment (20) having a plurality of stud bolts (28) protruding from an upper surface thereof; And a plurality of collets (32) detachably coupled to the respective stud bolts at a lower end corresponding to an upper surface of the coupling portion (26) of the attachment; A ram 40 on which the ram head 30 is mounted at the tip; A saddle 50 to which the ram 40 is mounted and drives the ram up and down; A cross rail 60 for supporting the saddle 50 movably in the left and right direction; And a pair of columns 70 for supporting the cross rail 60 at both ends thereof.

Further, the present invention further includes means for preventing the attachment from dropping, wherein the drop preventing means includes a step 130 formed on one side of the ram head 30; Has a pin (122) that protrudes and advances in a direction toward the step (130) when the attachment (20) is engaged with the ram head (30) and moves back out of the step when the attachment is separated from the ram head, And a clamp 120 formed on one side of the attachment corresponding to the position where the step 130 is formed.

Details of the anti-fall device according to the present invention are as follows. The clamp 120 includes a body 110 extending vertically from one side of the attachment 20 to a step 130, a hollow 112 having a predetermined diameter opened at the lower end of the body 110, And a driving direction changing means (122) formed at the upper end of the shaft rod (124) for converting the upward / downward driving of the shaft rod into the forward / backward driving of the pin (122) (140).

The hollow in the body of the clamp 120 also has a larger diameter enlarged portion 114 in a predetermined region and the shaft rod 124 has a stop portion 126 projecting radially corresponding to the enlarged portion 114 And the resilient means 128 is interposed in the space between the stopper 126 and the extension 114 so that the shaft rod can be elastically pressed downward by the resilient means to protrude and advance the pin 122 .

In the present invention, the driving direction conversion means 140 includes a guide groove 144 formed at the upper end of the shaft rod 124 and inclined upward in the direction toward the step 130, And a key 142 formed at an end of the guide groove 144 and engaged with the guide groove 144.

The details of other embodiments are included in the detailed description and drawings.

The machine tool according to the present invention as described above can be mounted on the side surface of the attachment and the ram head in addition to the hydraulic coupling between the stud bolt and the collet, The drop of the attachment can be prevented.

In addition, since the attachment can be prevented from dropping, it is possible to prevent damage to the attachment due to the drop, breakage of the machine tool at the falling portion, and injury of the operator, which may occur.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and how to accomplish them, will become apparent by reference to the embodiments described in detail below with reference to the accompanying drawings.

Like reference numerals refer to like elements throughout the specification.

Fig. 6 is a view showing an attachment of the attachment and a ram head shown in Fig. 6, and Fig. 7 and Fig. 8 are exemplary views showing a state in which the fall preventing means is operated, respectively.

The attachment 20 is coupled to the lower end of the ram head 30 through the engagement of the stud bolt 28 and the collet 32 and is further provided with a clamp 120 formed on one side of the attachment 20 And the mounting state is supported by the fall preventing means formed of the pair of stepped portions 130 formed on one side of the ram head 30. [

The detailed structure of the drop preventing means will be described below.

The fall preventing means is roughly divided into a step 130 formed on one side of the ram head 130 and a clamp 120 formed on the corresponding side of the attachment 20. The clamp 120 has a pin 122 that can be driven forward and backward toward the step 130. The pin 122 moves the up and down reciprocating movement of the shaft rod 124 to the driving direction changing means 140 And is driven back and forth by being transmitted through the forward and backward reciprocating motion.

The driving direction converting means 140 is constituted by a key 142 formed on the rear side of the pin 122 and a guide groove 144 formed on the upper end of the shaft rod 124 and guided by the above- At this time, the guide groove 144 is inclined upward in the direction toward the step 130, so that the upward and downward movement of the shaft rod 124 can be converted into forward and backward movement of the pin 122 and transmitted.

More specifically, when the shaft rod 124 moves downward, a key 142 fitted in the guide groove 144 moves backward along the guide groove 144, and the pin 122 moves backward And deviates from the step 130. When the shaft rod 124 moves upward, the key 142 inserted in the guide groove 144 moves forward along the guide groove 144, (130).

The structure of the clamp 120 will be described in more detail as follows. The clamp 120 has a main body 110 coupled to one side of the attachment 20 and extending upward to a position corresponding to the step 130 of the corresponding ram head when the attachment / A hollow 112 having a predetermined diameter is formed extending along the longitudinal direction so that the shaft rod 124 can be fitted. The hollow 112 has an enlarged portion 114 having a larger diameter at a specific point, for example, at a central portion thereof, to which the resilient means 128, such as a spring, do. A stop 126 protruding in a radial direction with a size corresponding to the diameter of the extension 114 is formed at one point of the shaft rod 124, (126) to define the lower limit of the range of movement of the shaft rod (124).

Specifically, the resilient means 128 is interposed between the upper boundary of the extension 114 and the stop 126 of the shaft rod 124, thereby acting as a main factor for moving the shaft rod 124 downward.

On the other hand, when the shaft rod 124 is moved downward by the urging of the elastic means 128, the lower end of the shaft rod 124 is formed to have a length sufficient to expose the outside of the clamp body 110. The length of the shaft rod 124 that is exposed to the outside of the main body 110 is a distance between the upper end of the hollow 112 and the upper end of the shaft rod 124 in a state where the shaft rod 124 is fully moved downward (I.e., the distance between the upper end of the hollow 112 and the upper end of the shaft rod).

The attachment fall preventing means having the above-described configuration can be operated as follows. Fig. 7 shows an example in which the drop prevention means is engaged and Fig. 8 shows an example in which the drop prevention means is released, respectively.

First, the fastening portion of the attachment 20 is coupled to the lower end of the ram head 30. At this time, hydraulic pressure is applied to the collet 32 in the form of wrapping the stud bolt 28 so that the collet 32 presses the stud bolt 28 The attachment 20 is attached to the ram head 30 by tightly holding and coupling the attachment. The attachment 20 is mounted on the ram head 20 while being placed on a so-called automatic tool changer (ATC), and after the ram head is mounted, the attachment 20 is moved to the automatic tool changer .

When the attachment 20 is released from the automatic tool changer, the resilient means 128 of the fall preventing means pushes the shaft rod 124 downward to its maximum extent, which causes the lowering of the shaft rod 124 The pin 122 is connected to the advance of the pin 122 via the conversion means so that the pin 122 is advanced and engaged toward the step 130 of the ram head 30. [ In this way, when the pin 122 is engaged with the step 130, even if the engagement between the collet and the stud bolt is released in a situation such as the leakage of oil pressure, the attachment 20 can be maintained in the state of being mounted on the ram head 30. [ . For example, unlike the case where the coupling between the collet and the stud bolt acts on an external force such as hydraulic pressure, since the drop prevention means of the present invention works only with a mechanical structure, Can be prevented from falling.

Therefore, the anti-fall device according to the present invention can prevent the attachment from dropping in the event of an emergency, and can fundamentally prevent damage to the attachment itself, breakage of a dropping point in the machine tool, or injury to an operator.

On the other hand, in order to exchange attachments or to terminate the operation and detach from the RAM head, the following procedure is performed.

The lower end of the shaft rod 124 protruding outside the clamp main body 110 is positioned on the receiving surface 150 of the automatic tool changer (ACT) And this pressing is larger than the elastic force of the elastic means 128, so that the shaft rod 124 is moved upward. At this time, it can be seen that the elastic means 128 'is compressed and a space spreads between the stop 126 of the shaft rod 124 and the lower end of the hollow extension 114.

When the shaft rod 124 is lifted, the key 142 inserted in the guide groove 144 of the shaft rod 124 moves rearward (for example, in the direction opposite to the stepped direction) The pin 122 that moves together moves away from the step 130 and the fall prevention means is released.

The engagement between the collet and the stud bolt is released by removing the hydraulic pressure applied to the collet 32 after the drop preventing means is released or at the same time so that the attachment 20 can be completely detached from the ram head 30 have. Although the present embodiment has been described with reference to the example in which the drop preventing means is provided at one side of the attachment and the ram head, it is obvious that the number of the fall preventing means can be freely configured.

As described above, since the operation of the fall preventing means is performed based on the upward and downward movement of the shaft rod 124, the process of attaching / detaching the attachment 20 to / from the ram head 30 is automatically performed Regardless of whether it is performed manually or manually. Particularly, the operation and release of the drop preventing means can be easily associated with the automatic tool changer accommodating a plurality of attachments, so that it can be easily applied to a machine tool, for example, a three-dimensional machining apparatus that frequently exchanges attachments.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. will be.

It is therefore to be understood that the embodiments described above are to be considered in all respects only as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, It is intended that all changes and modifications derived from the equivalent concept be included within the scope of the present invention.

The anti-drop device according to the embodiment of the present invention can be used in a machine tool for exchanging / attaching various kinds of attachments.

1 is a perspective view showing an example of a conventional machine tool.

FIGS. 2 and 3 are perspective views showing examples of a ram head and attachment employed in the apparatus of FIG. 1, respectively; FIG.

4 is a side sectional view showing a state in which the ram head and the attachment are engaged;

5 is a photograph illustrating an example of an attachment body damaged due to the drop of the attachment;

FIG. 6 is a side sectional view showing a combined state of the ram head and the attachment according to the present invention; FIG.

Figs. 7 and 8 are illustrations showing the state in which the attachment fall prevention means of Fig. 6 is activated / released.

DESCRIPTION OF THE REFERENCE NUMERALS (S)

10: Machine tool 20: Attachment

22: Tool 24:

26: fastening part 28: stud bolt

30: ram head 32: collet

40: Rams 50: Saddles

60: Cross rail 70: Column

80: control unit 110:

112: hollow 114:

120: Clamp 122: Pin

124: shaft rod 126:

128, 128 ': elastic means 130: step

140: driving direction converting means 142:

144: guide groove 150: receiving surface

Claims (3)

(20) having a main body (24) formed with a tool (22) for machining a workpiece, a fastening part (26) formed on the upper part of the main body, and a plurality of stud bolts (28) protruding from the upper surface of the fastening part ); And A ram head (30) having a plurality of collets (32) detachably coupled to the respective stud bolts at a lower end corresponding to an upper surface of the coupling part (26) of the attachment; A ram head of a machine tool, A step 130 formed on one side of the ram head 30; A pin 122 that protrudes and advances in a direction toward the step 130 when the attachment 20 is engaged with the ram head 30 and retracts from the step when the attachment is detached from the ram head; A clamp 120 formed on one side of the attachment corresponding to the formation position of the step 130; Further comprising: at least one attachment drop preventing means, The clamp (120) A body 110 extending vertically from one side of the attachment 20 to the step 130, A hollow 112 having a predetermined diameter opened at a lower end of the main body 110, A shaft rod 124 inserted into the hollow of the body and driven up and down, A driving direction converting means 140 formed at an upper end of the shaft rod 124 for converting the upward and downward movement of the shaft rod into reverse and forward driving of the pin 122; And a ram head attachment preventing device for preventing dropping of the ram head attachment of the machine tool. The method according to claim 1, The hollow of the body of the clamp 120 has an enlarged diameter portion 114 in a predetermined region and the shaft rod 124 has a stopper portion protruding in the radial direction corresponding to the extension portion 114 And an elastic means 128 is interposed in a space between the stopper 126 and the extension portion 114 so that the shaft rod is elastically pressed downward by the elastic means, Of the ram head attachment preventing device of the machine tool. The method according to claim 1, The driving direction converting means 140 includes a guide groove 144 formed at the upper end of the shaft rod 124 and inclined upward in the direction toward the step 130, And a key (142) engaged with and engaged with the guide groove (144).

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