JPH0429505B2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is an improved automatic tool changer (hereinafter referred to as ATC) used in machining centers, etc.
Regarding.

Prior Art The tool change speed of ATC is usually set to a slow speed suitable for heavy tools in consideration of safety.

Problems to be Solved by the Invention Since a slow tool change speed set in combination with heavy tools directly affects the machine operating rate, a constant slow tool change speed had the problem of inefficiency. .

Means to solve the problem In a machining center, a rotary arm that is rotatable and has a tool attached to its tip is provided with a roller that rolls on the machine base when moving, and a spindle on the back side of the machine base allows it to rotate up and down. A pivotably supported arm is provided, a measurement piece is provided at one end of the arm and is vertically movably inserted through a window of the machine base on the rolling trajectory of the roller, and the measurement piece is urged upward by the arm. a spring for controlling the measuring piece, a means for regulating the upper end of the measuring piece to be flush with the rolling surface and a lower limit position, and a detecting means for outputting a signal when a weight of more than a predetermined value acts on the measuring piece, A drive means controlled by the output of the detection means is provided, and the tool changing speed is switched to a low speed based on the output of the detection means.

Embodiments Hereinafter, embodiments of the present invention will be described based on the drawings. In a known horizontal machining center, a saddle 2 is movably placed on a sliding guide surface in the Z-axis direction cut on the right side of the upper surface of a bed 1.
A rotating table 3 is rotatably and indexably provided on a sliding guide surface in the X-axis direction cut into the upper surface of the rotating table 3.
A rectangular column 4 is erected on the left side of the upper surface of the bed 1, and a spindle head 5 is movably provided on a sliding guide surface in the Y-axis direction cut in the center of the column 4.
A main shaft 6 is rotatably supported on the shaft. Furthermore, a tool magazine device 7 is installed on the side of the column 4, and a magazine pot 8 for storing a plurality of tools T with the tool axis perpendicular to the main shaft 6 is connected endlessly with a link-like chain, and a drive (not shown) is provided. It is indexed to index position A by the indexing device. Further, a sub-arm device 9 is attached to the side surface of the column 4 on the tool magazine side. Sub-arm 1 of sub-arm device 9
It has a gripping claw for gripping the tool T at 0, is movable in the axial direction of the magazine pot by a drive mechanism (not shown), and can be moved in the vertical direction along the guide rail, and is attached to the index position A of the magazine and on the column 4. Tools are exchanged and transported between the magazine-side rotation position B of the ready station device 11, which will be described later.
The swing arm 12 of the lady station device 11 is rotatably supported via a plurality of bearings on a spindle 15 that is vertically fitted to a spindle support 14 fixed on the lady station frame 13, and is supported by a 90° swing actuator 16. The magazine is rotated to the above-mentioned magazine side rotation position B and ATC side rotation position C. Then, a positioning pin 18 integrated with a piston fitted into a positioning cylinder 17 fixed parallel to the lower surface of the swing arm 12 engages with a positioning block 19 fixed at a corresponding position on the reception station frame 13, and the swing position B is reached. C is positioned. Furthermore, the support shaft 2 is attached to the lower surface of the positioning cylinder 17.
0 is fixed vertically, and a weight bearing roller 21 is rotatably provided at the tip of a support shaft 20, and the outer periphery of the roller abuts against the upper surface of the lady station frame 13 to support the weight. Furthermore, a ready station pot 22 is fixed to the tip of the swing arm 12, and a tool clamp cylinder 2 is attached to the underside of the ready station pot.
3 is fixed.

The main spindle 6 is installed between the ATC side rotation position C of the ready station and the tool change position E of the main spindle 6.
The ATC 24 for exchanging tools between the ATC 24 and the lady station pot 22 is fixed to the front surface of the column with the pivot axis of the twin arm 25 parallel to the main shaft 6.
The twin arm 25 has tool gripping portions at both ends, and is able to pivot between a horizontal standby position and a vertical tool insertion/extraction position, and is movable in the direction of the pivot axis.

The twin arm 25 is driven by a variable speed motor provided in a gear box (not shown) having a cam mechanism, and the variable speed motor may be, for example, a pole number changing motor.

Swivel arm 12 of lady station device 11
Trajectory D- on the lady station frame 13 when the weight bearing roller 21 provided at the
A weight discrimination device 26 is installed at the measurement position provided on the D line.
is installed. As shown in FIG. 3, the weight discrimination device 26 has an arm 29 rotatably mounted on a support shaft 27 fitted into a mounting hole 13a drilled in the lady station frame 13 via a support pin 28. A measuring piece 31 supported via a pin 30 at one tip of the measuring piece 31 is fitted into a hole 13b provided on the trajectory D-D line so as to be movable up and down. A limit switch LS is fixed through it. An upward blind hole 29a drilled in the other end of the arm 29 and a downward blind hole 13 bored in a corresponding position on the lower surface of the lady station frame 13
A spring 32 is interposed between the measuring piece 31 and c, so that the measuring piece 31 is always urged to protrude upward, and the stepped portion 31a of the measuring piece 31 comes into contact with the lower surface of the lady station frame 13, and the upper surface of the lady station frame and the measuring piece The upper end is on the same plane, and the lower limit position of the measuring piece 31 is regulated by a positioning bolt 33 provided on the arm 29.

Operation A plurality of tools T necessary for machining are stored in the magazine pot 8 of the tool magazine device 7, and the next tool is indexed to the index position A by the next tool command from the NC device 35. The indexed next tool is extracted from the magazine pot 8 by the sub-arm 10, ascends along the guide rail, and reaches the ready station pot 22 at the tip of the swing arm 12 at the magazine side swing position B.
inserted into. and tool clamp cylinder 23
The pressure oil supplied to the tool T is switched, and the next tool T is clamped by a clamp pin (not shown). Next, the pressure oil in the positioning cylinder 17 is switched, the positioning pin 18 moves back, and the pressure oil is supplied to the rear chamber of the cylinder of the 90° swing actuator 16, and the swing arm 1
2 is turned toward the ATC side turning position C.
The rotating arm 12 is the lady station frame 1
3. The weight of the arm including the next tool T is supported by the weight bearing roller 21 that comes into contact with the upper surface of the arm, moves along line D-D, and stops at turning position C on the ATC side. Swivel arm 1
2, the pressure oil supplied to the positioning cylinder 17 is switched, the positioning pin 18 advances and engages with the positioning block 19, and is positioned, and the next tool waits at this position until a tool change command is issued.

When cutting with the tool T attached to the spindle 6 is completed, the spindle head 5 is positioned at the tool exchange position E, and when a tool exchange command is issued from the NC device 35, the twin arm 25 is connected to the drive variable speed motor provided in the gear box. It is rotated 90 degrees by the spindle 6 to become vertical and simultaneously grips the used tool on the main spindle 6 and the next tool in standby. Next, the clamps on both tools are released, the twin arm 35 moves forward in the direction of the rotation axis, and both tools are extracted simultaneously, and then the twin arm 25
After turning 180 degrees, move back in the axial direction and place the next tool on the spindle 6 and the used tool on the ready station pot 2.
Insert into 2. Next, the twin arm 25 turns 90 degrees, leaving the tool behind, and becomes empty and horizontal, waiting. The tool inserted into the spindle 6 is clamped by a clamping device (not shown), and the spindle head 4 moves in the Y-axis direction, leaves the tool exchange position E, and begins cutting. Then, the used tool inserted into the ready station pot 22 is clamped by switching the pressure oil supplied to the tool clamp cylinder 23, and returned to the magazine pot 8 by the reverse movement described above.

Measuring piece 31 of the weight discrimination device 26 provided in the middle of the D-D line of the lady station frame 13
is pressurized by the passing weight bearing roller 21 and moves downward against the spring 32, and the limit switch LS
move the moving parts of. The limit switch LS is designed to output a signal to the NC when a predetermined weight is added to the measurement piece 31. For example, if the weight of the next tool during transportation is more than a predetermined weight, a signal is output to the NC device, and the NC With the control output signal from the device
The pole number conversion motor for ATC drive is switched to the low speed side, and in response to a tool change command, the pole number conversion motor rotates at a slow speed to perform tool exchange. This slow exchange speed is maintained until the heavy tool finishes machining, becomes used, and is returned to the ready station pot 22, and the next tool is a lightweight tool whose weight does not reach the specified weight.
Even if the limit switch LS does not output a signal, if the used tool on the spindle 6 is a heavy tool, the tool is replaced at a slow speed. Then, only when both the next tool and the used tool are lightweight tools, the pole number changing motor is rotated at a high speed side, and the tool is replaced at a high speed commensurate with the lightweight tools.

This method automatically measures the tool weight, so there is no need to measure and memorize the tool weight in advance, and the tool change speed is set to a fast speed suitable for lightweight tools only when using heavy tools. It becomes possible to switch to a slower speed.

Effects As detailed above, in the present invention, the ATC speed is controlled by providing a means for determining the tool weight, so it is possible to change the tool at a fast speed suitable for the tool weight, and the machine operating rate is improved. This has the effect of improving

[Brief explanation of drawings]

Figure 1 is a top view of the reception station, Figure 2 is a partially cutaway side view of Figure 1, and Figure 3 is a top view of the reception station.
The figure is a cutaway view taken along the line E in FIG. 1, and FIGS. 4 and 5 are views of the horizontal machining center. 24...Automatic tool changer, 26...Weight discrimination device, 34...Tool information reading/writing device, 35...
NC device.

Claims (1)

[Claims] 1 In a machining center, a rotary arm that is rotatably provided and has a tool attached to its tip is provided with a roller that rolls on the machine base when moving, and an arm that is pivotally supported on the back side of the machine base so as to be able to vertically rotate is provided on the back side of the machine base. , a measuring piece is provided at one end of the arm and is vertically movably inserted through a window of the machine base on the rolling trajectory of the roller; a spring is provided on the arm to bias the measuring piece upward; A means is provided for regulating the upper end of the measuring piece to be flush with the rolling surface and at a lower limit position, and a detecting means is provided so as to output a signal when a weight of more than a predetermined value acts on the measuring piece, and the output of the detecting means is What is claimed is: 1. An automatic tool changer, comprising: a drive means controlled by the detection means; the tool change speed is switched to a low speed based on the output of the detection means.