KR20110071264A - Drop preventing means for ram head attachment of machining center - Google Patents

Abstract

PURPOSE: An apparatus for preventing drop of an attachment for a ram head of a machining center is provided to prevent the drop of the attachment even if oil is leaked, since the apparatus is fastened to the side of the ram head and the attachment. CONSTITUTION: An apparatus for preventing drop of an attachment for a ram head of a machining center comprises one or more attachment drop preventing units. The attachment drop preventing unit consists of a stepped unit(130), a pin(122) and a clamp(120). The stepped unit is formed on one side of a ram head(30). When the attachment(20) is coupled to the ram head, the pin is protruded and moved to the stepped unit. When the attachment is separated from the ram head, the pin is separated from the stepped unit and moved back. The clamp is formed on one side of the attachment corresponding to the location of the stepped unit.

Description

Drop preventing means for ram head attachment of machining center

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

Computerized Numerical Control (CNC) devices have been developed and are now widely used in addition to computer control functions. In particular, a device that directly processes a three-dimensional shape by exchanging a plurality of attachments, which is distinguished from a lathe device in charge of simple machining, is also called a double column type machining center.

1 shows an example of a three-dimensional machine tool commonly used. According to FIG. 1, a conventional machine tool includes a ram head 30 on which an attachment is detachably mounted, a ram 40 on which a ram head 30 is mounted at a tip end, and a ram 40 on which a ram 40 is mounted. And a pair of columns 70 supporting the cross rails 60 at both ends thereof, including a saddle 50 for driving the up and down, a cross rail 60 for movably supporting the saddle 50 from side to side. In addition, such a structure can be suitably controlled through the control unit 80 for controlling the overall machine tool, thereby processing a three-dimensional product having a desired shape.

The tool for processing the workpiece is provided in the form of an attachment to the ram head 30, the details of which attachment 20 and ram head 30 are shown in Figs.

Referring to Figures 2 and 3, the attachment 20 is a tool 22 for directly machining the workpiece is formed at the bottom of the main body 24, the coupling of a plurality of stud bolts 28, such as the top of the main body 24 The fastening part 26 in which the means was formed is formed. For example, the shape of the fastening part 26 is uniform for all attachments, and the shape of the tool 22 under the fastening part 26 is applied differently.

The ram head 30 having a structure for mounting such an attachment 20 includes hydraulic means called collets 32 as coupling means. For example, as shown in the figure, the groove of each of the stud bolts 28 formed at the four upper surfaces of the fastening portion 26 of the attachment 20 is accommodated on the surface of the ram head (the lower end of the ram head) corresponding to the fastening portion 26. Four are formed, and the collet 32 which can hold and fix the stud bolt 28 hydraulically in the groove is formed.

An example in which attachment 20 is mounted to ram head 30 through engagement of stud bolt 28 and collet 32 is illustratively shown in FIG. 4.

In the left part of FIG. 4, it can be seen that the collet 32 is formed around the stud bolt 28. When attachment 20 is engaged for mounting on ram head 30, collet 32 located around stud bolt 28 expands by hydraulic pressure, causing stud bolt 28 to fall below ram head 30. In the case of being firmly fixed so as not to go out and being detached to replace the attachment, the hydraulic pressure applied to the collet 32 is released so that the stud bolt 28 can be freely released. It is also evident that other additional coupling structures may be used in addition to the coupling of the stud bolts 28 and the collet 32, but it is clear that the main engagement of the attachment mounting in general depends heavily on the hydraulic coupling of the stud bolts and the collet. .

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

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

For example, in case that a problem occurs in the hydraulic circuit (eg, hydraulic pump, hydraulic conduit, hydraulic valve, etc.) supplied into the apparatus in that the force for operating the collet 32 is caused by hydraulic pressure, The expansion force, that is, the force holding the stud bolt 28 is lowered, which may cause the attachment 20 to fall off from the ram head 30.

Since the attachment 30 has a considerable weight, the attachment 30 may be greatly affected in proportion to the falling height, and thus the main body constituting the attachment is easily damaged. An example of such a damaged body is illustrated in FIG. 5. 5 shows a cylindrical body constituting the main body 24 of the attachment, in which a crack is generated in the body by the impact.

In addition, unlike the damage to the main body of the attachment in this way, the fall of the attachment may damage the corresponding point of the machine tool, or may even be injured by the attachment falling by the operator. In particular, if the fall of the attachment occurs in the case of mounting or replacing the attachment manually, it can lead directly to the injury of the operator can be developed into a safety problem apart from the cost problem.

Therefore, the technical problem to be achieved by the present invention is to provide a means for preventing the attachment fall when mounting / replacing the attachment.

In addition, the present invention is to provide a machine tool configured to be easily carried out mounting / replacement of the attachment even if the attachment fall prevention means is configured.

Machine tool according to an embodiment of the present invention for achieving the above technical problem, the main body 24 is formed with a tool 22 for processing a workpiece, the fastening portion 26 formed on the upper portion of the main body, and the fastening portion An attachment 20 having a plurality of stud bolts 28 protruding from the upper surface; And a ram head 30 having a plurality of collets 32 detachably coupled to each stud bolt at a lower end corresponding to an upper surface of the fastening part 26 of the attachment. A ram 40 to which the ram head 30 is mounted at the tip; Ram 40 is mounted, the saddle 50 for driving the ram up and down; A cross rail 60 supporting the saddle 50 to be movable from side to side; And a pair of columns 70 supporting the cross rails 60 at both ends thereof.

In addition, the present invention further includes a means for preventing the fall of the attachment, the fall prevention means includes a step 130 formed on one side of the ram head 30; When the attachment 20 is coupled to the ram head 30, it protrudes forward in the direction toward the step 130, and when the attachment is separated from the ram head, it has a pin 122 to escape from the step and back, And a clamp 120 formed on one side of the attachment corresponding to the formation position of the step 130.

In addition, the detail of the attachment fall prevention means which concerns on this invention is as follows. The clamp 120 includes a main body 110 extending vertically from one side of the attachment 20 to the step 130, a hollow 112 having a predetermined diameter opened at the lower end of the main body 110, and A drive rod converting means which is inserted into the hollow and is driven up and down, and is formed at an upper end of the shaft rod 124 to convert an up / down drive of the shaft rod into a reverse / forward drive of the pin 122. And 140.

In addition, the hollow in the body of the clamp 120 has an enlarged portion 114 of a larger diameter in a predetermined region, and the shaft rod 124 has a stop 126 protruding in a radial direction corresponding to the expanded portion 114. With the elastic means 128 interposed in the space between the stopper 126 and the expansion part 114, the shaft rod is elastically pressed downward by the elastic means to protrude and advance the pin 122. .

In addition, in the present invention, the driving direction converting means 140 is formed on the upper end of the shaft rod 124 and guide groove 144 inclined upward in the direction toward the step 130, and the rear of the pin 122 The key 142 is formed at the end and engaged with the guide groove 144.

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

Machine tool according to the present invention made as described above, in addition to the conventional hydraulic coupling of the stud bolt and the collet, in addition to the attachment and the side of the ram head to support the mounting state, even in case of emergency such as hydraulic leakage The attachment can be prevented from falling.

In addition, since the fall of the attachment can be prevented, damage to the attachment due to the fall, damage to the machine tool at the dropping portion, and injury to the worker that can occur can be prevented.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings.

Like reference numerals refer to like elements throughout.

6 is an exemplary view of the attachment and the ram head shown in the attachment drop prevention means according to the present invention, Figures 7 and 8 are exemplary views showing a state in which the drop prevention means is operating.

According to the drawings, the attachment 20 is coupled to the lower end of the ram head 30 through the combination of the stud bolt 28 and the collet 32, and in addition to the clamp 120 formed on one side of the attachment 20 and The mounting state is supported by drop prevention means formed of a pair of steps 130 formed on one side of the ram head 30.

The detailed structure of the fall prevention means is as follows.

The fall prevention means is largely divided into a step 130 formed on one side of the ram head 130 and a clamp 120 formed on a corresponding side of the attachment 20. The clamp 120 has a pin 122 that can be driven forward / reverse toward the step 130, which pin 122 drives the up and down reciprocating movement of the shaft rod 124. It is driven back and forth by receiving it through back and forth reciprocating motion.

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

In detail, when the shaft rod 124 moves downward, the key 142 fitted in the guide groove 144 moves backward along the guide groove 144, whereby the pin 122 moves backward. Out of step 130. On the contrary, when the shaft rod 124 moves upward, the key 142 fitted in the guide groove 144 moves forward along the guide groove 144, whereby the pin 122 is stepped in the ram head 30. It will fit into 130 and engage.

In addition, the structure of the clamp 120 will be described in more detail as follows. The clamp 120 is coupled to one side of the attachment 20 and has a main body 110 extending upward to a position corresponding to the step 130 of the corresponding ram head when the attachment / ram head is coupled. There is formed a hollow 112 of a predetermined diameter extending along the longitudinal direction so that the shaft rod 124 can be fitted. This hollow 112 has an extension 114 having a larger diameter at a certain point, for example at its central part, with the extension 114 intervening in a compressed state with elastic means 128 such as a spring. do. In addition, a stop 126 protruding in a radial direction to a size corresponding to the diameter of the extension 114 is formed at one point of the shaft rod 124, wherein the lower boundary of the extension 114 is a stop In conjunction with 126, the lower limit of the moving range of the shaft rod 124 is defined.

Specifically, the elastic 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 major factor for moving the shaft rod 124 downward.

On the other hand, when the shaft rod 124 is moved downward by the pressure of the elastic means 128, the lower end of the shaft rod 124 is formed to a length sufficient to expose the outside of the clamp body (110). At this time, the length of the shaft rod 124 exposed to the outside of the main body 110 is left between the upper end of the hollow 112 and the upper end of the shaft rod 124 in the state in which the shaft rod 124 is moved downward downward. It should be less than or equal to the height of the space (ie, the distance between the top of the hollow 112 and the top of the shaft rod).

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

First, the fastening portion of the attachment 20 is coupled to the lower end of the ram head 30, and at this time, hydraulic pressure is applied to the collet 32 having the shape of wrapping the stud bolt 28 so that the collet 32 applies the stud bolt 28. By firmly gripping and engaging, the attachment 20 is mounted to the ram head 30. The attachment 20 is mounted on the ram head 20 in a state of being placed on a so-called automatic tool changer (ATC), and the ram head is moved up and down after the attachment, so that the attachment 20 is an automatic tool changer. Detached from and separated.

When the attachment 20 is disengaged from the automatic tool changer, the elastic means 128 of the drop preventing means is stretched to the maximum to push the shaft rod 124 downward, which causes the lowering of the shaft rod 124 in the driving direction. It is connected to the advancing of the pin 122 through the conversion means, and eventually the pin 122 is advanced toward the step 130 of the ram head 30 to engage. As such, in the state where the pin 122 is engaged with the step 130, the attachment 20 can remain attached to the ram head 30 even if the collet and the stud bolt are released in the event of a hydraulic leak. Will be. For example, unlike the combination of the collet and the stud bolts acting under an external force such as hydraulic pressure, since the drop preventing means of the present invention acts only by a mechanical structure, it is securely attached without being affected even in the event of a hydraulic leak. Can prevent falling.

Therefore, the attachment drop prevention means according to the present invention can prevent the attachment fall in case of emergency can fundamentally prevent damage to the attachment itself, breakage of the drop point in the machine tool, or injury to the operator.

On the other hand, the following procedure is performed to remove the attachment from the ram head by replacing the attachment.

When the attachment 20 is placed in an accommodating part such as an automatic tool changer (ATC), the lower end of the shaft rod 124 that protrudes out of the clamp main body 110 has an accommodating surface 150 of the automatic tool changer (ACT). Is pressurized, and the shaft rod 124 moves upward because such pressurization is greater than the elastic force of the elastic means 128. In this case, it can be seen that the elastic means 128 ′ is compressed and a space is opened between the stop 126 of the shaft rod 124 and the lower end of the hollow expansion part 114.

On the other hand, when the shaft rod 124 is raised, the key 142 fitted in the guide groove 144 of the shaft rod 124 is moved rearward (for example, in the opposite direction to the step), and the key 142 and The pins 122 moving together move away from the step 130 so that the fall prevention means is released.

After the fall prevention means is released, or at the same time, by removing the hydraulic pressure applied to the collet 32, the engagement between the collet and the stud bolts is released, and the attachment 20 can be completely separated from the ram head 30. have. In addition, the present embodiment has been described with reference to an example in which one fall preventing means is formed on one side of the attachment and the ram head, but the number may be freely configured.

As described above, since the actuation and release of the fall prevention means are simply performed based on the vertical movement of the shaft rod 124, the attachment / detachment of the attachment 20 to the ram head 30 is automatically performed. It can be applied regardless of whether it is performed by hand or manually. In particular, since the actuation and release of the drop preventing means can be easily associated with an automatic tool changer that accommodates a plurality of attachments, it can be easily applied to machine tools that frequently change attachments, such as three-dimensional processing devices.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains can understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. will be.

Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is represented by the following detailed description, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

Attachment fall prevention means according to an embodiment of the present invention can be used in a machine tool for replacing / mounting a variety of attachments.

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

2 and 3 are perspective views showing examples of ram heads and attachments, respectively, employed in the apparatus of FIG. 1;

Figure 4 is a side cross-sectional view showing a state in which the ram head and the attachment is coupled;

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

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

7 and 8 are exemplary views illustrating a state in which the attachment drop preventing means of FIG. 6 is activated / deactivated.

(Explanation of symbols for the main parts of the drawing)

10: machine tool 20: attachment

22: tool 24: main body

26: fastening part 28: stud bolt

30: ram head 32: collet

40: ram 50: birds

60: cross rail 70: column

80: control unit 110: main body

112: hollow 114: extension part

120: clamp 122: pin

124: shaft rod 126: stop

128, 128 ': elastic means 130: step

140: driving direction converting means 142: key

144: guide groove 150: storage surface

Claims (3)

Attachment 20 having a main body 24 having a tool 22 for processing a work piece, a fastening portion 26 formed on an upper portion of the main body, and a plurality of stud bolts 28 protruding from an upper surface of the fastening portion. ); And A ram head 30 having a plurality of collets 32 detachably coupled to respective stud bolts at a lower end corresponding to an upper surface of the fastening part 26 of the attachment; In the ram head of the machine tool comprising: A step 130 formed at one side of the ram head 30; A pin 122 protruding forward in the direction toward the step 130 when the attachment 20 is coupled to the ram head 30 and exiting 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; Ramhead attachment fall prevention device of the machine tool further comprising one or more attachment fall prevention means consisting of a pair of. The method of claim 1, The clamp 120 includes a main body 110 extending vertically from one side of the attachment 20 to the step 130, and a hollow 112 having a predetermined diameter opened at a lower end of the main body 110. And a shaft rod 124 inserted into the hollow of the main body and driven up and down, and formed at an upper end of the shaft rod 124 to drive the up / down driving of the shaft rod to the reverse / forward driving of the pin 122. Drive direction converting means 140 for converting to, The hollow in the main body of the clamp 120 has an enlarged portion 114 having a larger diameter in a predetermined region, and the shaft rod 124 has a stop portion protruding in a radial direction corresponding to the expanded portion 114. 126, and the elastic rod 128 is interposed in the space between the stopper portion 126 and the expansion portion 114 so that the shaft rod is elastically pressed downward by the elastic means so that the pin 122 is disposed. Ram head attachment fall prevention device of the machine tool to project forward. 3. The method of claim 2, The driving direction converting means 140 is formed at the upper end of the shaft rod 124 and formed at the rear end of the pin 122 and the guide groove 144 inclined upward in the direction toward the step 130. And a key (142) engaged with the guide groove (144) and fastened to each other.

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