GB2122118A - Tool changing apparatus for machine tools - Google Patents

Abstract

An automatic tool changer has a tool change carrier (4) which travels on a rail system (5, 6, 7) provided between a tool magazine (1) and a main spindle (3) of the machine tool. The characteristic feature of said automatic tool exchanger is that its tool exchange carrier (4) is designed to move vertically together with a portion (7) of the rail to the location of the main spindle head (12) of the column so that the tools can be exchanged without necessitating the change in the position of the main spindle (3) in the middle of the processing work. <IMAGE>

Description

SPECIFICATION Spindle tracking automatic tool changer for machine The present invention relates to an automatic tool exchanger, and particularly to an improved automatic tool changer (hereinafter, referred to as ATC) for choosing a tool optionally from a number of tools stored in a tool magazine and for freely exchanging tools by mounting and dismounting them onto and from a main spindle of a machine tool.

The conventionally used types of ATC include that wherein the exchanging arm is attached directly to the tool magazine for delivering and receiving the tools to and from the main spindle, that wherein only the tool magazine is provided and the main spindle moves to directly go and get the tool, and that wherein the rail is provided between the specified position of the main spindle and the tool magazine and the tool exchange is performed by means of the tool exchange carrier.

Of those types mentioned above, that using the tool exchange carrier is applicable also to the large size of tool magazine and the tool exchanging operation can be done reliably. However, when the linear rail alone is used for it, the tool magazine must be disposed in parallel with the main spindle, and also, because the positioning of the tool magazine too close to the main spindle causes the hindrance in operation, the large distance must be provided between them. Thus, this system was disadvantageous in that it requires the expansion of the floor area.

Previously, in order to obviate the aforesaid disadvantages of the prior art, the inventor of the present invention had developed a system wherein the tool magazine is provided at the side of the machine tool and through the combined use of the linear rail and the curved rail, the special relay arm is unnecessitated. The said system was offered by the inventor in the Patent Application 1979 No. 1 12243.

The ATC system proposed by the present invention is similar to the abovementioned system provided previously in its plan layout, but the marked difference lies in its layout in vertical plan that characterizes the present invention. In other words, it differs in the position for exchanging tools from the carrier to the main spindle. That is, as to the position of the carrier in relation to the main spindle in exchange of tools, in the conventional system, the position of the guide rail was fixed to be stationary so that the main spindle head can always be exchanged at the upper end, while in the present invention, the followup travelling system is employed so that the carrier can be moved vertically to the position of the main spindle head no matter where the main spindle is located along the gamut of its vertical movement.

Thus according to the present invention there is provided a spindle tracking automatic tool changer comprising: a tool magazine; a main spindle of a machine tool; a rail provided between the tool magazine and said main spindle of the machine tool; and a tool exchange carrier that runs between said tool magazine and said main spindle of the machine by way of said rail for performing the automatic exchange of tools and is designed to be movable together with a portion of said rail in parallel with the travelling track of the main spindle head of the column whereby making it possible to exchange the tools without requiring the shift in the position of the main spindle during the machining operation.

In the accompanying drawings: Figure 1 is a plan view showing an embodiment of the invention with the ATC provided for a horizontal boring machine; Figure 2 is a front view showing the tool magazine; and Figure 3 is a front view showing the main spindle.

Detailed description will hereunder be given of the embodiment of the ATC system according to the present invention with reference to the drawings. As should be apparent from Figure 1, the tool magazine 1 is disposed at the side of the horizontal boring machine column 2, and the main spindle 3 of the horizontal boring machine is directed to the right side in the figure, with the angle different by 90 degrees from that of the tool magazine 1. With positioning arranged as mentioned above for the ATC system in its layout, even when the machining operation is carried out with large motion in front of the main spindle 3, the work can be performed without getting any interference because the tool magazine 1 is hidden behind the flank of the colum 2.In this system, the exchange of the tools between the tool magazine 1 and the main spindle 3 is conducted by the automotive tool exchange carrier 4 (hereinafter referred to as the carrier), and the carrier 4 runs shuttling on the rail system composed of the linear rail 5, the curved rail 6, provided on the magazine side, the linear rail 7 provided on the main spindle side.

As shown in Figure 2, the carrier 4 is equipped with the chuck arm 9 having the chuck claws 8, 8' on the right and left sides, and the said chuck arm 9 rotates 180 degrees centering around the spindle 10 and also moves backward as well as forward for serving to mount and dismount the tools 11 between the tool magazine 1 and the main spindle 3. Consequently, the tool mounting/dismounting position A of the tool magazine 1 and the tool mounting/dismounting position B of the main spindle 3 must come to the exactly same horizontal plane to share each other.

For that purpose, conventionally, it was designed that the main spindle head 12 slides vertically over the column to use the position of the main spindle at the uppermost location of the sliding range as the tool mounting/dismounting position B mentioned above. Therefore, when to exchange the tools in the middle of the processing operation, the main spindle 3 had to be moved to the tool mounting/dismounting position B from the working position C, then, after exchanging the tools, again, the main spindle 3 had to be returned to the working position. Such movement of the main spindle 3 in the middle of the processing operation is undesirable because it not only invites the wasting of the processing time as well as the wear of the sliding surface, but also causes the degradation of the accuracy of machining operation.

The present invention is featured in that the improvement is worked out to move the tool carrier in accordance with the position of the main spindle without requiring to change the position of the main spindle during the processing operation, and that the carrier is moved vertically together with a portion of the rail adjacent to the main spindle side, in parallel with the vertical movement of the main spindle. Its structural embodiment is shown in Figure 1 through Figure 3. That is, of the rails for the travelling of the carrier 4, the linear rail 7 of the main spindle side is cut off from the other rails, and made to be movable in a manner to follow up the main spindle.In other words, 2 guide rails 13, 13 for vertical movement are provided in parallel to each other at the main spindle side flank of the column 2, and the installing base 14 for the linear rail 7 of the main spindle side moves up and down along the guide rails 13, 13. The driving device 1 5 for the said up and down movement is the electric motor or the hydraulic motor, with the chain gear 16. For the conformity with the main spindle position, the coordination bracket 17 is provided on the main spindle head 12 side, while the stopper 18 is disposed on the installing base side.

Next, the description on the operating steps for this system will be given. In Figure 1, the necessary tool 1 1 is moved to the specified position A of the tool magazine 1 and stopped there; at this point, the carrier 4 is moved to the left and caused to grasp the tool 11 with the chuck claw 8; then, carrier 4 goes towards right side; and travels on the magazine side rails, from the linear rail 5 to the curved rail 6 until it reaches to the linear rail 7 on the main spindle side; and gets to the position marked with single dot chain line in the figure.Right after then, as shown in Figure 3, the carrier 4 goes down along the guide rail 13, together with the installing base 14 and the main spindle side linear rail 7 until reaching to the spot exactly beside the position C of the main spindle 3, that is marked with double dot chain line: and stops when the stopper 18 comes into contact with the coordination bracket (17).

Furthermore, the carrier 4 approaches up to the position marked with double dot chain line in Figure 1; grasps with its chuck claw 8' the tool 11 mounted on the main spindle; then the chuck arm 9 moves forward as well as rotates 180 degrees and aligns the tool 1 1 to be exchanged by the chuck claw 8 with the main spindle 3; after then, retreats and inserts the said tool 11 into the main spindle 3.When the exchange is completed, again, the carrier 4 returns to the position marked with single dot chain line in Figure 1; and moves up until the linear rail 7 on the main spindle side comes to meet the curved rail 6; then, returns horizontally onto the linear rail 5 on the magazine side; and stops at the position marked with solid line; there, returns the tool 1 1 to the specified empty position of the tool magazine 1 by turning the direction of the chuck claw 180 degrees; thereafter, proceeds to the position marked with the solid line; and completes the one cycle of operation by taking the stand-by position for the next move.

The carrier 4 is of the automotive type, and same as in the conventional models, its movement is controlled electrically by means of the limit switches and the electric signals. When the signal for exchanging the tool to be used next is given, the operation starts by taking the steps mentioned above. Therefore, wherever the main spindle 3 is located, the carrier can be moved freely to follow up that location, thereby making it feasible to exchange the tools without changing the working position of the main spindle 3.

The ATC system according to the present invention is characterized in the design that the carrier is capable to move in tuning with the vertical movement of the main spindle so that, as was mentioned above, the exchange of the tools can be done without shifting the position of the main spindle during the processing operation, and also the improvement in the working accuracy as well as the cutting down in the time for exchanging the tools can be achieved.

Furthermore, because the carrier can be separated optionally from the position of the main spindle during the processing operation by keeping it in the stand-by position, the system can be prevented from getting dusty by the chips during the machining operation or getting stained with the oil and the water for cooling. In addition, while usually, the ATC system provided for the horizontal boring machines or other machine tools are mediated by many relay arms in its operation to deliver and receive the tools to and from the main spindle, the ATC system according to the present invention can perform such operation by letting the tool exchange carrier hold the tool just once, therefore, the system can be simplified, and also the safety of the operation can be improved as the accident by dropping the tools during the exchange can be avoided.

Claims (3)

1. A spindle tracking automatic tool changer comprising: a tool magazine; a main spindle of a machine tool; a rail provided between the tool magazine and said main spindle of the machine tool; and a tool exchange carrier that runs between said tool magazine and said main spindle of the machine by way of said rail for performing the automatic exchange of tools and is designed to be movable together with a portion of said rail in parallel with the travelling track of the main spindle head of the column whereby making it possible to exchange the tools without requiring the shift in the position of the main spindle during the machining operation.

2. A spindle tracking automatic tool changer according to Claim 1, wherein said rail comprises a first portion adjacent to said tool magazine, a second portion curved toward said main spindle and a third portion vertically movable with said carrier, said third portion being adjacent to said main spindle.

3. A spindle tracking automatic tool changer, substantially as hereinbefore described with reference to the accompanying drawings.