JPH035938B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic tool changer in an NC machine tool.

Generally, tool exchange in this type of device involves holding a tool inserted into the spindle and a specific tool called to the tool exchange position of the tool magazine at both ends of a tool exchange arm, and then holding the tool at both ends of the tool exchange arm. The tool is moved forward and backward in the axial direction of the main spindle to be extracted, and the tool exchange arm is reversibly rotated to simultaneously transfer and exchange the tools.

In such an automatic tool changer, a pair of gripping claws that make up the tool change arm move from a standby position to prevent collisions with tools inserted into the spindle to a tool exchange position for used tools and magazines on the spindle. A turning operation is performed to simultaneously grasp the called specific tool, then a turning operation is performed to exchange the positions of these tools, and further an axial forward and backward movement is performed to extract and insert the tool.

Conventionally, as a means for performing these turning operations of the tool changing arm, there is a method in which the arm turning axis of the tool changing arm is turned by the forward and backward movement of the rack by meshing the rack and pinion. In order to obtain the arm rotation angle, two parallel racks are provided perpendicular to the arm rotation axis,
The rack was driven by two types of cylinders with different strokes, and in other words, the selection of these two types of rotation angles involved engaging and disengaging the rack and pinion by sliding movement in the axial direction of the arm rotation axis. was.

In addition to the above-mentioned rack and pinion system, for the same purpose, torque actuators each having two types of rotation angles are provided on the arm rotation shaft, and the torque actuator is controlled by the axial movement of the arm rotation shaft. Two types of turning angles were selected by engaging and disengaging a spline shaft from a gear fitted into the rotor shaft of the motor.

However, since each of these swing systems engages and disengages from the swing drive unit, the former is easy and
In the pinion method, these meshing positions must be maintained accurately at all times, making it difficult to adjust the easy position. Furthermore, in the latter case,
In order to obtain two types of rotation angles, the spline shaft is engaged and disengaged in the same way as described above, so the engagement positions of the splines are limited, and there is a drawback that fine adjustment of the rotation angle of the arm rotation axis cannot be made and it remains fixed. .

The present invention has been made to solve the above-mentioned drawbacks, and in order to obtain two types of rotation angles of the arm rotation axis, a threaded portion is provided at one end of the shaft body that can rotate together with the arm rotation axis. In order to rotate the central shaft by forward and backward movement due to the action of a female screw screwed into the screw part and a cylinder, and further to rotate this central shaft by a combination of a rack and pinion, each of these rotating devices is divided into two parts. A tool changing device is provided.

Embodiments will be described below with reference to the drawings. FIG. 1 is a schematic side view of a machining center equipped with an automatic tool changer of the present invention, and FIG. 2 is a sectional view taken along line AA of the same.

A tool storage magazine 4 is located on the side of the main spindle 3 supported by the column 2 of the machining center 1, and an automatic tool changer 5 is located adjacent to the main spindle 3 and the tool storage magazine 4. This automatic tool changer 5 is supported by the column 2 by a support 6 at its upper position, has a shaft body 8 at its axis, and its outer periphery is covered by a box body 32, and the upper part of the box body 32 is a block 27. , a cover 33 is attached to the lower part. An arm up/down cylinder 30, which is a third cylinder, is rotatably attached to and hangs down from a support member 28 which is arranged in parallel with this box body 32 and protrudes from the block 27.

Further, the automatic tool changer 5 has an arm pivot shaft 7' and a tool exchange arm 7 in the lower part thereof, and this arm pivot shaft 7' has a sliding bearing 40 fitted into a support member 41 protruding from the column 2. It is slidably and rotatably guided by.

The upper and lower parts of the box body 32 are closed by a block 27 and a cover 33, respectively, and the inside of the block 27 constitutes a first cylinder 12, the upper part of which is covered with a cover 34. A collar 37 is fitted inside the cover 33, and the thrust bearings 3 are connected to both upper and lower sides of the collar 37.
The adapters 35 and 35 are attached through the screws 6 and 36, and the upper adapter 35 is brought into contact with the stepped portion C of the shaft body 8, and the other adapter 35 is tightened with a nut 38 near the stepped portion D of the shaft body 8. It will be done. A male screw 9 is formed in the upper part of the shaft body 8, a spline is formed in the lower part, and the nut 3 is connected to the screw in the intermediate part.
8 are screwed together.

A female screw 10 is screwed into the male screw 9, and a pinion 11 is fitted into the outer circumferential surface of the female screw 10, and together with an adapter 16 disposed on the upper end surface of the female screw 10, a positioning pin 17 and a bolt 1 are fitted.
8 is integrally fastened. The pinion 11
A rack 19 provided perpendicularly to the axial direction of the shaft body 8 is engaged with the shaft body 8.

The adapter 16 has a hollow cylindrical shape with a mounting hole at its axis, and the operating rod 14 of the cylinder 12 disposed on the upper part of the adapter 16 has a bearing 4 in the mounting hole.
8 and 48, and is fastened with a nut 15.

A piston 13 is fitted into the other side of the operating rod 14 and fixed with a nut 15.

On the other hand, the lower part of the shaft body 8 has a spline shaft 20.
An arm pivot shaft 7' is fitted and suspended from the spline shaft 20, and a sleeve 22 is screwed to the upper end of the arm pivot shaft 7'.

An adapter 23 is attached to the outer peripheral surface of this sleeve 22.
and the connecting member 2 via the thrust bearings 24, 24.
1 is rotatably attached to the nut 2 with respect to the sleeve 22.
6 is concluded.

The other side of the connecting member 21 is connected to a piston rod 31 of the arm up/down cylinder 30.

Next, FIG. 3 shows a sectional view taken along line B-B in FIG.
2, and pistons 4 are installed at both ends of the rack.
3 and 43 are attached, and the pistons 43 and 43 are slidably fitted into sleeves 44 and 44, respectively,
Cylinder 45, 45a, each of which is a second cylinder
It consists of Further, the outer sides of the sleeves 44, 44 are covered with the case 42, and the case 42 is constructed integrally with the box body 32.

Both ends of the case 42 are screwed and closed with covers 46, 46, and stroke adjusting screws 47, 47 are mounted on the axes of the covers 46, 46, respectively.

To explain the operation of the automatic tool changer with the above configuration, first, a used tool is extracted from the spindle 3, and a tool to be used for the next machining is extracted from the tool storage magazine 4 and inserted into the spindle 3. However, the tool exchange arm 7 waits at a specific position so as not to come into contact with the tool due to the rotation of the main shaft 3. That is, as shown in FIG. 4 1, which is an explanatory diagram of the operation of the tool changing arm 7, it is normally on standby on the side of the main shaft 3, and when changing tools, it rotates, for example, at an angle of 70 degrees in the direction of the arrow, as shown in FIG. 4 2. A tool inserted into the spindle 3 and a tool inserted into a tool pot (not shown) of the tool storage magazine 4 are held simultaneously. Next, as shown in FIG. 4, the tool exchange arm 7 is moved downward in the direction of the arm rotation axis 7' (in the direction of the arrow), and the tools held at both ends of the tool exchange arm 7 are exchanged. As shown in Fig. 4, rotate the tool exchange arm 7 by 180 degrees in the direction of the arrow, and move the tool exchange arm 7 with this positional relationship upward in the direction of the arm rotation axis 7' (in the direction of the arrow) (see Fig. 4 and 5). After inserting it into the tool pot (not shown) of the magazine 4, as shown in FIG. 4, it is rotated by 70 degrees in the opposite direction to the operation shown in FIGS. 2 and 4, and stopped at the standby position.

To functionally explain the above-mentioned rotational movement and arm rotation axis direction movement with reference to FIGS. 2 and 3,
In the figure, the automatic tool changer 5 is supported by the column 2 by the support 6 at the upper position as described above, and the arm pivot shaft 7' is slidable in the axial direction by the support member 41 at the lower position. It is rotatably supported.

Therefore, when an attempt is made to move the operating rod 14 of the cylinder 12 toward the male screw 9 by the action of hydraulic pressure, the adapter 16, which is fastened to the working rod 14 and integrally connected to the female thread member 10 and the pinion 11,
Due to the rack 19 meshing with the pinion 11, it moves in the same direction as the operating rod 14 without rotating.

For this reason, the male screw 9 internally screwed together with the female screw 10 is held in contact with the adapter 35, so that it cannot move in the axial direction and rotates by being screwed with the female screw 10.

The rotation angle at this time is determined by the amount of movement of the operating rod 14 and the lead of the screw, and the rotation direction is determined by the thread cutting direction.

Since the shaft body 8 is thereby rotated, the arm pivot shaft 7' that meshes with the spline shaft 20 is also rotated at the same time. In this way, by rotating the tool by 70 degrees (see FIG. 4, 2) and gripping the tool, and extending the piston rod 31 of the arm up/down cylinder 30, the arm rotation axis 7' and the tool exchange arm 7 will move in the axial direction of the spline shaft 20. (see Fig. 4, 3).

For this reason, the tool inserted into the spindle 3 and the new tool at the tool exchange position P are pulled out at the same time, and in order to exchange these tools with each other, that is, the new tool is inserted into the spindle 3, and the used tool is removed from the spindle 3. 180 degrees in the same direction as above to move the tool to the tool change position P.
This is done by moving the rack 19 in a straight line and rotating the pinion 11.
When the pressure oil on the side 5a is removed and pressure oil is supplied on the side of the cylinder 45, the rack 19 moves downward.

Note that the stroke amount at this time is cylinder 45, 4.
It can be adjusted by stroke adjustment screws 47, 47 disposed on the same axis of 5a.

Therefore, the pinion 1 meshing with this rack 19
1 rotates counterclockwise (with respect to the drawing). Then, the male screw 9 meshes with the female screw 10 on the inside.
Since the movement in the axial direction is restricted by the adapter 35 and the nut 38, the shaft rotates together with the pinion 11.

Subsequently, when the operating rod 14 of the cylinder 12 is moved upward (with respect to the drawing), the arm pivot shaft 7' rotates by 70 degrees in the opposite direction.

In this state, it returns to the original standby state.

As described above, in the present invention, when the arm rotation device is divided into two parts and accurate rotation positioning is required, adjustment can be easily made using adjustable stoppers provided at both ends of the rack.

Furthermore, since there is no engagement and disengagement with the rotation drive unit due to axial movement to obtain two types of rotation angles, reliable operation is possible.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention.
The figure is a schematic side view of a machining center equipped with an automatic tool changer, the second figure is a sectional view taken along line A-A, and the third figure is a schematic side view of a machining center equipped with an automatic tool changer.
The figure is a sectional view taken along the line BB in FIG. 2, and FIG. 4 is an explanatory diagram of the operation of the tool exchange arm. 3...Spindle, 4...Tool storage magazine, 5...
Tool exchange device, 7... Tool exchange arm, 7'...
Arm rotation axis, 8... Shaft body, 9... Male screw, 10
... Female screw, 11 ... Pinion, 12 ... Cylinder (first cylinder), 13 ... Piston, 14
... Operating rod, 19 ... Rack, 20 ... Spline shaft, 21 ... Connection member, 30 ... Cylinder for arm up and down (third cylinder), 31 ... Piston rod, P ... Tool exchange position, 45, 45a...
cylinder (second cylinder).

Claims (1)

[Claims] 1. In an automatic tool changer that uses a tool changer arm to exchange tools inserted into the spindle of a machine tool and tools in a tool storage magazine, the base of the tool changer has a base that is regulated in the axial direction by the base and that a shaft body that is freely supported and has a male screw at one end and a spline that engages with the tool exchange arm so as to be relatively movable in the axial direction at the other end, and is provided parallel to the arm rotation axis of the tool exchange arm; a female screw member having a gear on its outer periphery and screwed onto the male screw of the shaft body so as to be rotatable and movable in the axial direction; a first cylinder to be moved;
a rack provided on the base so as to be movable back and forth in a direction perpendicular to the axial direction of the shaft body and constantly engaged with a gear of the female screw member; and a rack provided on the base so that the female screw member is at a predetermined axial position. a second cylinder for moving the rack forward and backward in order to rotate the shaft; and a second cylinder provided at the base for engaging with the arm pivot shaft of the tool exchange arm and moving the tool exchange arm in the axial direction. An automatic tool changer comprising a third cylinder, and wherein the tool change arm, which is movable in an axial direction, is configured to be pivotable by the operation of the first cylinder or the second cylinder.