JPH0611939U - Automatic tool changer - Google Patents

Abstract

(57) [Abstract] [Purpose] An automatic tool changer for the purpose of easily returning an emergency stopped transfer line to its original position in a transfer line composed of a large number of machine tools with automatic tool changer such as a machining center. It is an object of the present invention to provide an automatic tool changer which constantly monitors the operation position of the revolving arm and enables the output of an appropriate operation signal and the return operation at the revolving arm stop position by simply pressing the return button. [Structure] Swiveling of swivel arm B and tool insertion / removal operation A shaft of a rotary encoder E and a cam shaft 3 fixed to a bracket 13 mounted on a side surface of an automatic tool changer A for constantly monitoring the rotational angular position of a drive cam. The rotation of is synchronized with the synchro belt 12.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an automatic tool changer attached to a numerically controlled machine tool.

[0002]

[Prior art]

 An arm swiveling type automatic tool changer is known in which a swivel arm and a tool inserting / removing operation are driven by a brake motor or the like using a roller gear cam, a groove cam or the like. This method is used as a method to determine the swivel movement of the swivel arm and the operation timing of the hydraulic cylinder that clamps and unclamps the tool mounted on the spindle. When the swivel arm's original position detection proximity switch and the proximity switch are turned off. It was necessary to have a circuit to measure the time within the timer interrupt routine in order to compare the experimental data during steady operation with how many seconds after which the tool for spindle attachment should be unclamped.

Therefore, the time required for the motor that drives the automatic tool changer that stops during turning to reach steady rotation varies with the unclamping operation timing of the spindle-mounted tool, and the automatic tool changer returns to its original position. Is becoming even more difficult.

[0004]

[Problems to be solved by the device]

 The conventional method cannot automatically return the automatic tool changer to the original position when the automatic tool changer is in an emergency stop or the power is turned off during operation.

For this reason, it is necessary for the operator to make a judgment, and the automatic tool exchanging device while individually judging the returning direction of the cam axis of the automatic tool exchanging device that stops during turning and the variation of the unclamping timing of the tool equipped with the spindle. Is returning to its original position. For this reason, it takes a long time to return to the original position, and if the operation of returning to the original position is mistaken, it causes problems such as dropping an expensive tool and damaging the work.

In particular, in a transfer line composed of a plurality of machine tools with an automatic tool changer, it is necessary to consider the control software of the device that stops at various operation timings, and also the opportunity to make an emergency stop. Because of the increase, the conventional method that cannot return the original position of the entire transfer line without returning the automatic tool changer to the original position has a big problem that it requires a lot of labor and time.

[0007]

[Means for Solving the Problems]

 Means for solving the above problems is an absolute type rotary encoder capable of constantly monitoring the rotational angle position of a cam for driving a swing arm and outputting a confirmation signal at any position. By using the control circuit and the program for returning to the original position, the returning direction of the rotating arm stopped at an arbitrary position and the unclamping timing of the tool equipped with the spindle are made to correspond, and the original position can be easily returned by the push button operation. It is a featured automatic tool changer.

[0008]

[Action]

 When the automatic tool changer of a machine tool with an automatic tool changer makes an emergency stop during operation The output signal of the rotary encoder that recognizes the cam position during the tool change operation is the previous process when the operator presses the original position return operation button. It is mounted on the spindle depending on whether the tool changer is returned to the original position by returning the original position return program that determines whether to return to the original position or to advance to the subsequent process, and by rotating the stopped rotating arm in either direction from the stop position. Whether the tool is clamped or unclamped at appropriate swivel arm operation timing is performed according to a pre-assembled control circuit, and the original position of the transfer line composed of multiple machine tools with automatic tool changer can be easily restored. be able to.

[0009]

【Example】

 An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an external view of a swivel arm B of an automatic tool changer A according to the present invention as viewed from the mounting side. FIG. 2 is an external view of the numerically controlled machine tool equipped with the automatic tool changer A as seen from the spindle S side. 3 and 4 are cross-sectional views of the essential parts of the automatic tool changer A, and FIG. 5 is an operation diagram showing the turning of the turning arm B and the tool withdrawing stroke ST.

The rotational force of the brake motor D is transmitted to the intermediate shaft 1 via the gear and is transmitted to the cam shaft 3 meshing with the gear 2 fixed to the intermediate shaft 1. A roller gear 5 fixed to the cam shaft 3 meshes with the roller 6 to rotate the rotating arm shaft 7. The lever 8 swings the cam follower 9 by means of a groove cam formed on the bottom surface of the gear 4 that meshes with the gear 2 fixed to the cam shaft 3, and the roller 10 at the tip of the lever causes the swivel arm shaft 7 to axially move the tool. It is structured such that it can operate only the pull-out stroke ST.

The turning motion of the turning arm B and the operation timing of the tool withdrawing stroke ST are as shown in FIG. 5, and the gripping claws of the turning arm at the stop position P1 of the turning arm B shown in FIG. During one cycle, the schematic of the swivel arm shows the stop position of the swivel arm gripper pawls, and the arrow shows the next direction of movement of the swivel arm. Further, U represents the unclamping operation range of the tool mounted on the spindle, and C represents the clamping operation range of the tool mounted on the spindle.

The synchro pulley 11 fixed to the cam shaft 3 is connected to the rotary encoder E fixed to the bracket 13 via the synchro belt 12, and the rotational angle position of the cam shaft 3 can be constantly monitored by the rotary encoder E. There is.

Conventionally, when an emergency stop is applied during tool exchange, the swivel arm is swung in a predetermined direction by inching to a position where the tool can be removed from the spindle, and then the The tool is removed, the swivel arm is rotated in the forward direction for one cycle, the tool number is checked against the actual machine, and the original position of the automatic tool changer is completed. Only after that, the entire transfer line could be restored to its original position.

In the present invention, by constantly monitoring the rotational angle position of the cam shaft 3 with a rotary encoder, it is dependent on the operator to judge the return rotational direction of the revolving arm B and to remove the tool as in the prior art. It is an automatic tool changer that can incorporate a home position return program and control circuit that can return the home position of the entire transfer line by operating the home position return push button once. In this embodiment, the rotation of the cam shaft is transmitted to the rotary encoder by the synchro belt, but it goes without saying that the design can be changed by directly mounting the rotary encoder on the cam shaft.

[0015]

[Effect of device]

 As described in detail above, the automatic tool changer according to the present invention constantly monitors the rotation angle position of the drive cam shaft for arm rotation and tool insertion / removal operation by the rotary encoder, so an emergency stop occurs during the tool change operation. It is possible to easily return to the original position even by applying. In particular, in the transfer line consisting of the numerical control machine tool with the device of the present invention, it is not necessary to return the original position of the automatic tool changer to the original position as in the past, and the entire transfer line is temporarily moved to the original position. This is an automatic tool changer that can be returned and can greatly reduce the labor and time required for conventional home position return.

[Brief description of drawings]

FIG. 1 is an external view of an automatic tool changer according to the present invention.

FIG. 2 is an external view of a numerically controlled machine tool equipped with the automatic tool changer of the present invention.

3 is a cross-sectional view as seen from the III-III cross section of FIG.

FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG.

FIG. 5 is an operation diagram showing swivel arm swivel and tool withdrawal operations, and spindle clamp and unclamp timing.

[Explanation of symbols]

 A Automatic Tool Changer B Swing Arm C Spindle Clamping Operating Range D Brake Motor E Rotary Encoder M Tool Magazine P1 to P4 Swinging Arm Stop Position S Spindle ST ST Tool Extraction Stroke U Spindle Unclamping Operating Range 1 Intermediate Axis 2, 4 Gear 3 Cam Axis 5 Roller gear 6,10 Roller 7 Revolving arm shaft 8 Lever 9 Cam follower 11 Synchro pulley 12 Synchro belt 13 Bracket

Claims (1)

[Scope of utility model registration request] 1. A clamp for a tool mounted on a spindle by using a cam for pivoting a pivot arm and inserting / removing a tool.
In an automatic tool change type machine tool that performs unclamping operation with a separate actuator such as a hydraulic cylinder, the rotation of the swing arm and the tool insertion / removal operation An absolute type rotary encoder is attached to the axis that can constantly monitor the rotation angle position of the drive cam, and an emergency stop is performed. An automatic tool changer that outputs a confirmation signal of the arm stop position at the time to the numerical control device and can automatically return to the original position with one push button operation via the control circuit and the original position return program.