JPS6176246A - Automatic tool changer - Google Patents

Abstract

PURPOSE:To make each tool to be returned from a spindle restorable all to its original housing position and fixed address type tool selection performable, by setting the number of socket housing parts of a magazine down to at least N+1 to the working tool number N. CONSTITUTION:After toll changing, since an empty socket 25, as a tool T1 is pulled out, is left behind in an engaging fork 47, it is necessary to put the tool back to a tool magazine 16, but a holder of a tool T commanded as the first is necessary to be emptied for a working tool T at the final process. Therefore, after the magazine 16 is indexed so as to cause the holder at the (N+1)th address to be situated in a tool setting position P4, the fork 47 is retracted to some extent, and when the socket 25 is put back to the position P1, the socket 25 is engaged with the holder 24 at the (N+1)th address, and since a member 63 comes into contact with a separation preventing member 51, this member 51 turns round counterclockwise against the pressing force, whereby engagement between an engaging groove 53 and a pin 54 is set free. Therefore, any obstacle in a traveling route of the socket 25 is brought to nothing as well as a chain 23 of the magazine 16 is indexed so that the tool is restorable to its original position.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an automatic tool changer that takes out a predetermined tool stored in a tool magazine together with a socket and inserts it into the main shaft of a machine tool.

<Prior Art> In general, there are two types of tool selection methods in automatic tool changers: an address rewriting method and a fixed address method.

The former method is used when a tool stored in a magazine and a tool inserted into a spindle are exchanged at the same time using an exchange arm. In this case, the tool returned from the spindle is inserted into the storage position of the tool extracted from the magazine,
Due to a structural constraint that the tool cannot be returned to its original storage position, a process is performed within the control device to rewrite the number (address) of the returned tool.

For this reason, the control system becomes complicated and costs are inevitably high. Moreover, the arrangement order of the tools in the magazine changes every time the tools are replaced, which is inconvenient when the tools in the magazine are replaced as a result of a setup change accompanying a workpiece change.

On the other hand, the latter method is adopted for those equipped with an intermediate arm that takes out tools from the magazine and transfers them to the exchange arm.When returning a tool that has been removed from the spindle to the magazine, it is necessary to return the tool to the original storage where it was stored. The magazine is indexed so that the position is at the tool removal position, and then the tool return cycle is performed. As a result, all tools are always returned to their original storage positions in the magazine, so the arrangement order of the tools does not change, which is advantageous in changing the setup of magazine tools.

However, it is necessary to transfer the tool to and from the exchange arm, and the method of holding the tool in the intermediate arm requires some ingenuity. A standard holder cannot be used, which impedes the standardization of tools. Also, with the tool taken out with the intermediate arm, 1.
The shank portion of the tool is exposed, and if foreign matter such as chips adheres to it, the spindle insertion accuracy will be deteriorated, and this will also be a factor that impedes normal machining.

Therefore, as a tool holding means for the intermediate arm, there is a method in which the socket is taken out from the magazine, which solves the problem of transferring the tool to and from the exchange arm.

<Problem that the invention seeks to solve> However, it has the following problems.

In order to set the tool selection method to a fixed address type, it is impossible to return all tools to the magazine without leaving any tools in the spindle.

In other words, when there is no tool in the spindle and the tools stored in the sockets are in all storage positions of the magazine, the first tool is taken out with its socket and inserted into the spindle, and the subsequent sockets are returned to their original storage positions. I will have no choice but to return it. The second tool taken out is replaced with the tool in the spindle, that is, the first tool.

Since the empty socket has been returned to the storage position where the tool removed from the spindle should be returned to, it cannot be returned to its original storage position.

Therefore, although a fixed address system is physically impossible, the present invention
This problem has been solved and fixed address type tool selection has been made possible.

Function> In the present invention, the number of socket storage parts of the magazine is set to at least N+1 for the number N of tools used, and the empty socket after the first tool is taken out from the magazine and inserted into the spindle is placed at address N+1. If the tool is stored in the spindle, the original storage position of the tool inserted into the spindle remains empty, and when the second tool is removed and replaced, the second tool is inserted into the spindle and the tool removed from the spindle remains empty. can be placed in the socket 7) and returned to its empty original storage position. This means that the tool returned from the spindle can be returned to its original storage position even when the tool is replaced thereafter.

In addition, when all machining is completed and the last used tool is to be returned from the spindle to the magazine, the empty socket stored at address N+1 is taken out and the exchange arm is operated to transfer the tool on the spindle to the socket. , the original storage location of this tool is now empty, so you can return it here.

In this way, all the tools returned from the spindle can be returned to their original storage positions, so a fixed address system can be used for tool selection, and the tool arrangement order remains unchanged.

<Example> Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a vertical machine tool equipped with an automatic tool changer according to the present invention.
It has a column 1) that slides on it.

A spindle head 12 is guided and supported on the side surface of the column 1) so as to be movable up and down, and the workpiece W placed on the table 15 is moved up and down by moving the rod 12 up and down the spindle while rotating the main shaft 13 on the vertical axis. It is now ready for processing.

Furthermore, a tool magazine 16 is installed on the head 10 to store various tools T inserted into the main shaft 13. A tool transfer device 40 and a known exchange arm 20 are provided between the tool magazine 16 and the main spindle 13.
is installed.

This tool transfer device 40 transfers the tool between the tool exchange position P1 and the tool exchange position P2 while changing the attitude of the tool from a horizontal state to a vertical state. During this period, the tool T is transferred while maintaining its vertical posture.

A specific configuration of the tool magazine 16 is shown in FIG. This tool magazine 16 has a support frame 21 that stands up from above the bed 10. A sprocket wheel is rotatably supported on the upper end of the support frame 21, and a travel rail 22 is fixed to the lower end.
Endless chain 2 between 1 and running rail 22
3 is wound. The sprocket wheel 21 is rotatably driven by a drive motor via a well-known transmission mechanism such as a worm wheel, thereby causing the chain 23 to rotate. As shown in FIG. 3, a socket holder 24 forming a socket housing is fixed on this chain 23.
A tool socket 25 is detachably held at 4. Therefore, as the chain 23 rotates, the socket holder 24
In addition, the tool socket 25 is indexed to the tool insertion/removal position P1.

As shown in FIG. 5, the tool socket 25 has four engaging parts 26 on its outer periphery, and the engaging recesses 26 are inserted into and supported by the socket holder 24, which has a U-shaped cross section. 31, 32, 33, 34 (see FIG. 2), the tool socket 25 will not come off from the socket holder 24.

Further, the tool T is inserted into an insertion hole 27 of the tool socket 25, as shown in FIG. 3, and is configured to be easily inserted and removed.

Here, the number of socket holders 24 in the magazine 16 is set to N+1 where N is the maximum number of tools to be used, and at least one empty socket holder that does not hold a socket 25 is secured. This empty space is needed to return the empty socket after the first tool has been inserted into the spindle, as will be described later.

A tool transfer device 40 shown in FIGS. 3 and 4 is installed behind the tool magazine 16 having such a configuration. This tool transfer device 40 has a guide tube 41, and this guide tube 41
An actuating rod 42 is fitted therein so as to be slidable in the axial direction. Between this operating rod 42 and the guide tube 41,
A rotation mechanism 45 consisting of a U-shaped cam f843 and a cam follower 44 that engages with this cam groove 43 is provided, and the actuating rod 42 is moved forward and backward by a forward and backward cylinder 45 (drive actuator) provided behind it. is made to move helically following this cam groove 43.

An engagement fork 47 is wedged at the tip of the operating rod 42. A pair of engagement pieces 48° 48 are formed at the tip of the engagement fork 47 at a constant interval.
A space through which the tool socket 25 passes is formed between the engaging pieces 48, 48.

Therefore, the chain 23 is moved around and the tool socket 25 is
By positioning the tool socket 25 in the space between the engagement pieces 48 and 48 and moving the engagement fork 47 in the axial direction of the operating rod 42, the tool socket 25 can be engaged with and disengaged from the socket holder 24. ing.

Further, a detachment prevention member 51 having an opening-shaped cross section is pivotally supported on the engagement fork 47 by a pivot pin 50 . This detachment prevention member 51 has a locking groove 53 at its tip, and this locking groove 53 is engaged with and disengaged from the locking pin 54 of the tool socket 25 to prevent the tool socket 25 from falling off from the engagement fork 47. It looks like this. The actuating mechanism 60 of the detachment prevention member 51 includes a plunger 62 built into the engaging fork 47 and to which repulsive force is applied by a spring 61, and an abutment member 63 fixed on the support frame 21. Consisting of This contact member 63 is the engagement fork 47
The length is set such that when the tool socket 25 is at the rearward end, it comes into contact with the detachment preventing member 63 and separates from the detachment preventing member 51 just before the tool socket 25 comes off from the socket holder 24. Therefore, the detachment prevention member 51 rotates in conjunction with the movement of the engagement fork 47, causing the locking groove 53 of the detachment prevention member 51 to engage and disengage from the engagement pin 54 on the tool socket 25. There is.

FIG. 7 shows a control block diagram for controlling the indexing of the tool magazine 16 and the operation of the exchange arm 20 and the intermediate arm 40 as the tool transfer device. 100
1) is a numerical control device, and 1)0 is an exchange device control circuit which issues control signals to the exchange arm drive device 1) 1 and intermediate arm drive device 1) 2.

120 is a magazine indexing control circuit and the magazine drive device 1
A control command is issued in '30.

This indexing control circuit 120 controls the indexing of the magazine using the T code commanded from the numerical control device 100. Normally, the indexing control circuit 120 first calculates the storage address of the tool corresponding to the T code (T code and storage address). ) is indexed to the tool insertion/removal position, the tool is taken out with the socket by the intermediate arm 40, and replaced by the exchange arm 20, and then the storage position to which the tool removed from the spindle should be returned is determined. It's about to come out. A flowchart for performing such processing is shown in FIG.

However, the indexing control when taking out the first tool and when returning the last used tool to the magazine after finishing the final process machining is different from the normal case, so the former case and the latter case are shown in Fig. 8. The determination is made in steps (II and (2)). In the former case, the first control circuit 121 shown in the flowchart of FIG. Control.

Next, the operation of the above configuration will be explained.

FIG. 1 shows a state in which the machine is about to start operating, and in this state, no tool is inserted into the insertion hole of the main shaft 13. Further, at this time, the column 1) has been retreated to the rear tool exchange original position, and the spindle head 12 has also been raised to the upper tool exchange original position. On the other hand, the chain 2 of the tool magazine 16 is controlled by the T code issued from the numerical control device 100.
3 is also rotated, and the tool T to be used first is indexed to the tool loading/unloading position P1. When a tool change command is issued, the engagement fork 47 is moved to the tool insertion/removal position P by the advancing/retracting cylinder 45.
The tool socket 25 indexed at 1 and the tool T move forward while being engaged and supported, and when the tool socket 25 moves forward until just before it comes off from the socket holder 24, the contact member 63 separates from the detachment prevention member 51. As a result, the detachment prevention member 51 rotates clockwise about the pivot pin 50, and the tool socket 25 is prevented from falling off from the engagement fork 47.

When the actuating rod 42 is further advanced, a rotating mechanism 45 consisting of a cam groove 43 and a cam follower 44 imparts a rotational motion to the actuating rod 42, which causes the engaging fork 47 to pivot and be supported by the retaining fork 47. The postures of the tool socket 25 and the tool T are gradually changed from a horizontal state to a vertical state. During this turning, the tool socket 25 is prevented from coming off the engagement fork 47 by the detachment preventing member 51, and there is no fear that the tool socket 25 will fall off.

The retaining fork 47 is advanced to the forward end, and the tool socket 25 and the tool T are positioned at the tool exchange position P2. When the exchange command MO6 is issued from the numerical control device 100, the exchange command 20 moves axially and swivels by 1 tG), and inserts the tool T inserted into the tool socket 25 into the spindle 13. After inserting the first tool T to be used, the spindle head 12 descends and simultaneously moves forward to column 1) 4 to begin machining.

In this state, turn the engagement fork 47 to the tool T1.
An empty tool socket 25 is left after being pulled out, and it is necessary to return this tool socket 25 to the tool magazine 164. However, the socket holder of the first commanded tool T is empty in order to return the tool T used in the final process (it is necessary to return this tool socket and throat to the socket holder in the position from which it was taken out). Therefore, the tool magazine 16 is indexed so that the socket holder at address N+1 is located at the tool loading/unloading position PL, and after the indexing is completed, the engagement fork 47 is moved back by the advancing/retracting cylinder 45, and the empty tool socket 25 is moved back. is returned to the tool loading/unloading position P1.

At the same time as this engaging fork 47 is returned to the rearward end, the tool socket 25 is engaged with the socket holder 24 at address N+1, and at the same time, the contact member 63 abuts against the detachment prevention member 51, so that this detachment occurs. The prevention member 51 turns counterclockwise against the pressing force of the plunger 62, and the engagement groove 53 and the engagement pin 54 are disengaged. Therefore, in this state, there are no obstacles in the travel path of the tool socket 25, and the chain 2 of the tool magazine 16 is
3 is determined.

This operation is controlled by the first control circuit 121. To explain this with reference to FIG. 9, the commanded T-code is stored in the commanded tool register in step (1), and this T-code is compared with the current address indexed to the tool loading/unloading position P1 and they match. The magazine 16 is indexed until (step (2)). The tool commanded by the T code is at position P!
When the intermediate arm 40 is indexed, the intermediate arm 40 is operated and transferred to the position P2, and the exchange arm 20 is operated according to the exchange command MO6 and is inserted into the main shaft (step (3)).

The contents of the command tool register are shifted to the spindle tool register to store the T code of the tool inserted in the spindle (
Step (4)). N to restore the empty socket
After indexing the +1 address, return the intermediate arm and operate it (
Step (51, (61).

Thereafter, when the machining by the tool T is completed, the processing from step (3) in FIG. 8 is performed. Steps (3) and (41) of indexing the second tool to be used are performed, and the commanded tool is positioned at the tool insertion/removal position PI.

As before, the column and spindle head are moved to the tool exchange original position, and at the same time, the forward/backward cylinder is activated to take out the tool socket held in the second socket holder together with the tool T, and then the rotating mechanism moves it horizontally. The posture is changed from the state to the vertical state, and the tool is transferred to the tool exchange position P2. Then, the used tool T inserted into the main spindle and the tool T inserted into the tool socket are exchanged by the exchange arm 20 (step (5)).

After replacing, reinstall column 1) and spindle head 12.
are respectively advanced and lowered, and machining of the workpiece is started. On the other hand, in order to return the used tool T to the socket holder 24, which is its original storage location, the tool magazine 16 is indexed and returned (steps (81, (91)).

After the tool T is returned, the tool magazine 16 is indexed again and the tool T to be used next is indexed to the tool loading/unloading position Pl in preparation for the next exchange operation.

Thereafter, the same operation as above is repeated to sequentially insert the tools T into the spindle.

After the final step of machining is completed, the second control circuit 122 becomes effective in order to return the tool in the spindle to the magazine. This will be explained using the flowchart shown in FIG. The socket in which the tool in the spindle is stored is stored at address N+1, so in order to take it out, the magazine at address N+1 is indexed (step (1)), and this is taken out with the intermediate arm 40 to the tool exchange position. P2, the exchange arm 20 is operated, and the tool in the spindle is transferred to the socket. T of this tool
Since the code is stored in the spindle tool register, the code is shifted to the return tool register and the original storage position of the tool is indexed to the tool removal/removal position in order to return the code (4).
The intermediate arm 40 is moved back to return the tool to the magazine. In the above-mentioned embodiment, an example was explained in which one socket storage section was provided as a storage space for the first empty socket, but this storage space is not limited to one, and it is also effective even if there is a plurality of storage spaces. .

<Effects of the Invention> As described above, according to the present invention, in a tool changer that takes out tools stored in a magazine with their sockets, the number of socket storage sections in the magazine is set to N+1 for the maximum number of used tools N. With the above arrangement, it is possible to secure a storage space for an empty socket after the first tool to be used is removed. As a result, in subsequent tool exchanges, the tool can be returned to the same original storage position as the storage position from which it was taken out, making it possible to use a fixed address system. Therefore, the tool arrangement order within the magazine does not change, so tool setup changes can be performed extremely easily.

In addition, since the tool is taken out with the socket, even if the tool is left on standby at the tool exchange position P2 close to the machining position, foreign matter such as chips can be prevented from adhering to the tool shank, allowing high-precision machining to be maintained over a long period of time. .

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a side view of a vertical machine tool equipped with the tool transfer device of the present invention, FIG. 2 is a front view showing a tool magazine of the vertical machine tool, and FIG. Figure 3 is a sectional view taken along the line m-m in Figure 2, and Figure 4 is a cross-sectional view taken along the line m-m in Figure 2.
5 is a sectional view taken along the line V-V in FIG. 3, FIG. 6 is a sectional view taken along the line VI-VI in FIG. 4, and FIG. 7 is a control of the tool changer. FIG. 8 is a flowchart of the indexing control circuit, FIG. 9 is a flowchart of the first control circuit, and FIG. 10 is a flowchart of the second control circuit. Pl...Tool loading/unloading position, P2...Tool changing position,
T...Tool, 16...Tool magazine, 21...Support machine frame, 25...Tool socket, 40...Tool transfer device (intermediate arm), 42...Operation Rondo, 45...
・Drive actuator (advance/retreat cylinder), 47...
Engagement fork, 43... cam groove, 44... cam follower, 45... rotating mechanism, 51... detachment prevention member,
60... Operating mechanism, 51... Spring, 62...
- Plunger, 63... Contact member, 1) 0... Exchange device control circuit, 120... Index control circuit, 121...
- First control circuit, 122... second control circuit.

Claims (2)

[Claims] (1) A tool magazine that removably holds a plurality of sockets that hold tools to be inserted into the spindle at equal pitches on the circumference, and a tool that takes out the tools together with the sockets from this tool magazine and that is parallel to the axis of the spindle. a tool take-out device that transfers the tool to an exchange position; a tool change arm that allows the tool held in the tool take-out device to be exchanged with a tool inserted in the spindle; In an automatic tool changer equipped with an indexing control circuit that indexes a socket storage part of a tool to be returned to a tool take-out position, the number of socket storage parts of the tool magazine is N+1 or more with respect to the number N of used tools. Automatic tool changer. (2) When no tool is inserted into the spindle, the indexing control circuit extracts the tool from a specific storage section starting from address N+1 using an empty socket after inserting the first tool to be used. A first control circuit that indexes the position, and when returning the tool that was last inserted into the main spindle upon completion of machining, a specific tool storage section from address N+1 onwards is used to take out the tool in order to take out the empty socket. 2. The automatic tool changer according to claim 1, further comprising a second control circuit for indexing the position of the spindle tool and then indexing the original storage position of the spindle tool to the tool removal position.