JPS6144549A - Tool replacing device for machine tool - Google Patents

Abstract

PURPOSE:To replace a tool quickly and reliably by retracting the magazine table mounted with a rotary board on the spindle head by necessary stroke and insertion guiding particular tool supported by arm to the tool mounting section of spindle. CONSTITUTION:A rotary board 50 supported rotatably against a magazine table 34 will index necessary tool 30 from plural tool carry arms 60 through forward/ reverse rotation of motor 56 to rotate the arm 60 in a plane perpendicular against the rotary face of said board 50 under energizing function of an operating rod 70 thus to set the axis of tool 30 supported by the arm 60 at the position to be aligned with the axis of spindle and to advance/retract the draw bar horizontally to hold/release the pull stud 74 of tool 30.

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a tool changing device for a machine tool, and more specifically, a magazine stand equipped with a rotary plate for tool indexing is slidably supported on a spindle head. At the same time, a plurality of tool carrying arms capable of rotating in a plane perpendicular to the rotating plate are provided on the circumferential surface of the rotating plate at a predetermined distance apart, and any tool carrying arm can be moved by rotation of the rotating plate. After the spindle is indexed to a position facing the tool mounting portion, the tool transfer arm is rotated by a required angle from its standby position, and the specific tool supported by the tool transfer arm is mounted on the spindle. The present invention relates to a tool changing device configured to guide the jflI through the parts.

Conventional technology Machine tools such as machining centers (MCs), which are configured to multifunctionally perform various types of processing such as milling and drilling on workpieces, are equipped with tools such as price cutters and drills at designated locations. A tool changer (AT) stores a large number of tools in a magazine, selects a desired tool from the magazine at the appropriate time during machining, and automatically exchanges it with the tool that has completed machining.
C) is generally provided. Depending on the design specifications, this tool changer may be of a type such as an armless ATC in which the main shaft moves toward the tool magazine and receives the tools, or a type disclosed in Japanese Patent Application Laid-open No. 120943/1983. According to the invention, a number of tool carrying arms are arranged radially around a rotary plate, and the tool carrying arms are configured to be rotatable in a plane perpendicular to the rotating plate, so that a specific tool can be transported. A rotary indexing device is known.

The problem that the invention aims to solve In the prior art mentioned above, in the former type.

There is a drawback that the spindle head moves significantly away from the workpiece during machining and takes a long time to change tools because it goes to the magazine to receive the tools. In addition, in the latter type, when the tool transfer arm rotates in a plane perpendicular to the rotary plate, the arbor of the tool supported by the arm inevitably moves in an arc, so the arbor moves along the main axis. In order to be able to fit smoothly into the tool mounting portion, it is necessary to connect the swinging arm to the tool carrying arm to give it complicated motion, which has the drawback that the mechanism of the entire device becomes extremely complicated.

For this reason, drawbacks such as frequent failures and increased manufacturing costs have also been pointed out.

Purpose: In view of the above-mentioned drawbacks inherent in the conventional machine tool tool changing device in which a desired tool is indexed by rotating a magazine in which a large number of tools are arranged, the present invention provides a tool changing mechanism. With a simple configuration, the aim is to reduce manufacturing costs and failure frequency, and also to achieve rapid tool exchange.

Means for Solving the Problems As a means for solving the above-mentioned drawbacks, in the present invention, a spindle head rotatably supporting a spindle having a tool mounting portion at one end is attached to a workpiece held on a table. A machine tool that processes the workpiece by relatively reciprocating drive.
A magazine stand equipped with a rotary plate for tool indexing is horizontally slidably supported on the spindle head, and a tool carrying arm rotatable in a plane perpendicular to the rotary plate is attached to the rotary plate. A plurality of tool transfer arms are provided at a predetermined distance on the circumferential surface of the rotating plate η.
1, the tool held by the arm is located in front of the tool mounting part of the spindle, and
In addition, the dimensions are set so that the center axis of the tool is aligned with the axis of the tool mounting portion provided on the main shaft.

In the present invention, in a tool exchange operation, the rotary plate is rotated on the magazine table, and after indexing the tool carrying arm holding the desired tool to a position facing the tool mounting portion of the spindle, the tool is replaced. The transfer arm is rotated from its standby position to a required angle relative to the rotary plate, the tool held by the arm is brought to the front of the tool attachment part of the main spindle, the two axes are aligned, and then the magazine table on which the rotary plate is mounted is moved. Slide back the required stroke on the spindle head. As a result, the specific tool supported by the arm is smoothly inserted and guided into the tool mounting portion of the spindle, and reliable tool mounting is achieved.

Embodiment Next, the details of the tool changing device for a machine tool according to the present invention will be explained in detail by referring to a preferred embodiment and the accompanying drawings. FIG. 1 is a schematic configuration diagram of a machine tool equipped with a tool changer according to the present invention, and FIG.
2 is in the fully retracted position, and the 3rd
The figure shows the magazine platform 34 in its fully advanced position on the main branch head 12.

In the figure, a machine tool on which a tool changer according to the present invention is mounted has a spindle head 12 mounted on a machine base 10 so as to be able to slide in the horizontal direction, and a column 14 erected vertically on the machine base 10. The knee 16 is arranged so that it can be raised and lowered freely, and this knee 16
It basically consists of a table 18 disposed above and horizontally slidable in a direction perpendicular to the spindle head 12. Inside the spindle head 12, as shown in FIG. 3, a spindle 22, which has a tool mounting portion 20 formed of a tapered opening at one end, is supported horizontally so as to be rotatable. It is rotated by a drive motor 24. Further, the spindle head 12 is connected to another motor 2.
6 to move horizontally forward and backward on the machine base 10. That is, the workpiece 28 placed on the table 18 is moved by the movement of the table 18 in the X direction and the Z direction.
The combination of the vertical movement and the movement of the spindle head 12 in the Y direction gives a relative movement to the tool 30 mounted on the spindle head 12, for example a milling cutter, so that the desired cutting process can be performed. There is.

A magazine stand 34 on which a tool group 30 and a rotating plate 50 (described later) are mounted is supported on the spindle head 12 so as to be horizontally slidable along the axis of the spindle 22. That is, two guide bars 36° 36 (both guide bars are shown in FIG. 4) are attached to support protrusions 38 integrally provided on each top side of the rectangular bottom of the magazine table 34. It is inserted and fixed. The guide bars 36, 36 are slidably inserted into sliders 40, 40, which are integrally protruded near the top of each side of the spindle head 12, in a front-back relationship, and the magazine stand 34 is Guide bar 36.3
6 in the axial direction of the main shaft 22. As is clear from FIG. 2, the spindle head 12
A motor 42 for driving the magazine table is disposed inside, and the motor 42 drives the guide bar 3 via a gear train 44 consisting of a plurality of pinions.
It is designed to mesh with rack teeth 46 carved in the rear end of the 6. That is, by driving the motor 42 in forward and reverse directions, the guide bar 36 is moved between the gear train 44 and the rack teeth 4.
The magazine table 34 is also actively driven forward and backward along the axis of the main shaft 22, and these motors 42. Gear train 44.
The rack teeth 46 are collectively referred to as a magazine platform drive member.

The top of the magazine stand 34 is inclined forward at a predetermined angle with respect to the axis of the main shaft 22, as shown in FIGS. oriented. A rotating plate 50 as shown in the figure is rotatably supported on this rotating shaft 48 via bearings 52.52. That is, the rotary plate 50 is rotatably supported with respect to the magazine table 34, and the spur gear 54 integrally formed on the back surface of the rotary plate 50 is connected to the motor disposed obliquely on the magazine table 34. It meshes with a gear (not shown) fixed to a rotating shaft 58 of 56.

By rotating the motor 56 forward and backward, a plurality of tool transfer arms 6 rotatably supported on the rotary plate 50 are provided.
0 (described later), a desired tool 30 is indexed from among these spur gears 54. The motor 56 is collectively referred to as a rotary plate indexing device.

As shown in FIGS. 2 and 4, the rotary plate 50 is provided with a plurality of (six in this embodiment) tool transfer arms 60 in a radial direction centered on the rotational axis of the rotary plate 50. has been done. As shown in an exaggerated manner in FIG. 5, this tool transfer arm 60 is held between two crotches 62 that protrude in the radial direction from the circumferential surface of the rotating plate 50 at one end of the base side, and is pinned. 64, one rotating plate 5
0 (in a plane perpendicular to the plane of rotation) at a required center angle. As can be seen from FIG. 5, one end of the tool transport arm 60 that is pivotally supported by the two crotches 62 is also formed as a two crotch portion 66, and each of the two crotches constituting the two crotches 66 A cutout 68 of a desired shape is bored in the hole. and rotating plate 5
An operating rod 70, which will be described later, faces into the bifurcated portion 66 of the tool transport arm 60 indexed by the rotation of 0, and the operating rod 7
Both free ends of a pin 72 directly inserted and fixed into one end of the pin 72 are received in the notches 68 and 68 of the 2-inch piece, so that they can be engaged and disengaged.

The main body of the tool carrying arm 60 is gently curved outward as shown in FIG. 1, and various tools 30, such as a milling cutter, are held at the other end. Note that, as will be described later, after the tool is indexed by the rotation of the rotary plate 50, the tool transfer arm 60 rotates in a plane perpendicular to the rotational surface of the rotary plate 50 under the biasing action of the operating rod 70. . At this time, when the tool transfer arm 60 reaches the rest position farthest from the rotary plate 50.

The axis of the tool 30 held by the arm is aligned with the main shaft 22.
The positional relationship is set in advance to be aligned with the axis of.

The tool 30 includes a blade portion 30a such as a milling cutter provided at the tip, a shank 30b connected to the blade portion 30a and held by a tool carrying arm 60, and a conical arbor 30c.
This is a known type consisting of a pull stud 74 provided at the rear end, and a tool mounting portion 20 provided at the end of the spindle.
It is designed to be detachably attached to the That is, the tool mounting portion 20 is attached to the aperture 30c of the tool 30.
is formed as a truncated conical opening that allows insertion of the
As shown in FIG. 3, a tool holding member 7 is provided at the tip of a drawbar 76 that is slidably inserted into the hollow portion of the main shaft 22.
8 faces the opening, and the pull stud 74 of the tool 30
For example, the tool holding member 78, which has a mechanism for holding the tool so as to be opened and closed, has a known collet structure in which the neck portion of the pull stud 74 is surrounded by a plurality of balls 80 that can be moved toward and away from the pull stud 74. The pull stud 74 is clamped and released by horizontally moving the draw bar 76 forward and backward. Note that the drawbar 76 is always elastically biased forward of the main shaft by a compression spring 82 interposed therein.

Next, a drive mechanism for rotationally biasing the tool transfer arm 60 with respect to the rotary plate 50 will be described. The tool transfer arm 60 is
As can be seen from Figure 3, the lodging position indicated by the solid line is
It rotates around the pin 64 within the range up to the standing position (standby position) shown by the dotted chain line, and in this embodiment, this rotational movement is caused by the movement of the actuating rod 70 back and forth and the movement of the actuating rod 70. 70 and a notch 68 formed at one end of the tool carrying arm 60. That is, in FIG. 3, the magazine table 34 includes a fluid pressure cylinder 84.
is arranged horizontally, and a first rack 88 is fixed to the tip of a piston rod 86 that faces horizontally into the magazine table. Additionally, a pinion 90 (2
(shown by a dotted chain line) is rotatably supported and meshed with the first rack 88. Furthermore, the rear end of the operating rod 70 faces movably into the magazine stand 34, and a second rack 92 carved in the rear end of the operating rod is connected to the pinion 9.
It meshes with 0. In this case, when the piston rod 86 of the cylinder 84 is retracted into the cylinder tube, as shown in FIG. (left side in the figure) is set in a positional relationship such that it meshes with the pinion 90.

Therefore, if the cylinder 84 is energized, the piston rod 86
is extended, and while the first rack 88 is moved to the left to the position shown by the two-dot chain line, the pinion 90 is rotated counterclockwise, and the second rack 92, which forms part of the actuating rod 70, is also moved to the left at two points. It will be understood that it should be moved to the right (backward in the figure) to the position indicated by the chain line. Note that after the operating rod 70 has retreated to a position where it does not interfere with the tool transfer arm 60, the rotary plate 50
rotates to index the tool, and the actuating rod 70 moves forward toward the indexed tool transport arm 60.
The pin 72 is set in a positional relationship to engage with the notch 68 of the arm.

In the drawings, reference numeral 94 denotes a circular cover that surrounds the rotary plate 50 and the plurality of tool transfer arms 60 that are on standby, and this cover 94 covers the indexed tool transfer arms 60 as is clear from FIG. A notch 96 is provided to allow rotation of the holder. Further, reference numeral 98 indicates a stopper that restricts the retreat of the magazine stand 34 on the spindle head 12 within a predetermined stroke. Furthermore, each tool transfer arm 60
As shown in the figure, an elastic tongue piece {r00} is fixed, and the tongue piece 100 is formed correspondingly to the rotary plate 50 while the arm 60 stands up with respect to the rotary plate 50 and waits for indexing. It is designed to be stably held by engaging with the protruding piece 102 that has been formed.

Next, the operation of the tool changing device for a machine tool according to the present invention constructed as described above will be explained. In FIG. 1, when the tool 30 attached to the spindle mounting part 20 finishes cutting the workpiece 28 placed on the table 18, the spindle head drive motor 26 rotates to move the spindle head 12 to the base. 10
At the top, the tool is driven backward by the amount that the tool is removed and then stopped. At this time, the pull stud 74 of the tool 30 is
8 (spindle head retreats).

Therefore, if a cylinder (not shown) is energized and the drawbar 76 is moved to the left in FIG. moves freely, and the clamping of the pull stud 74 in the tool 30 is released (tool unclamping).
.

Next, the magazine stand drive motor 42 is rotated to engage and drive the gear train 44 and the rack teeth 46, so that the magazine stand 34, which connects the rack teeth 46 to the guide bars 36, 36, is connected to the spindle head 12. Slider 40 provided
．． 40 horizontally forward. At this time, the tool 30 has been unclamped, so the magazine stand 3
4 advances on the spindle head 12, the rotating plate 5
The tool conveying arm 60 attached to the tool holder 0 detaches from the tool mounting part 20 forward in the axial direction while holding the tool 30. As a result, the removal of the tool 30 is completed as shown in FIG. 3 (tool removal). In this case, as shown by the solid line in FIG. rod 86 of cylinder 84 is retracted),
The tip portion provided with the pin 72 is exposed into the bifurcated portion 66 of the tool transfer arm 60.

If the timing at which the removal of the tool 30 from the tool mounting portion 20 is completed is detected by an appropriate sensor and the cylinder 2' cylinder 84 is pressurized, the piston rod 86
extends from the cylinder tube and advances the first rack 88 to the left, the pinion 90 meshing with the first rack 88 rotates counterclockwise, and the pinion 9
The actuating rod 70 with the second rack 92 that engages with the second rack 92 is moved back to the right. That is, as shown in FIGS. 6(a) to 6(d), as the first actuating rod 70 is pulled in one direction to the right and retreats, the pin 72 provided at the tip of the rod
0 into the notch 68 formed.

The tool carrying arm 60 is rotated clockwise about the pivot 64. For example, in FIG. 6(a), the actuating rod 70, which is fully extended to the left as described above, has its tip end provided with the pin 72 brought close to the bifurcated portion 66 of the tool transfer arm 60. I'm letting you do it. As the actuating rod 70 retreats to the right, the pin 72 enters the notch 68 of the bifurcated portion 66 as shown in FIG. Start standing up.

The actuating rod 70 continues to move backward to the right, so the sixth
As shown in Figure (c), the tool transport arm 60 rises significantly in the clockwise direction. The tool transfer arm 60 is then moved to the position shown in FIG.
), the opening direction of the notch 68 is oriented toward the actuating rod 70, so the actuating rod 70 is removed from the notch 70, and the rotational force applied to the arm 60 is released. At this time, the tool carrying arm 60 is stably held on the rotating plate 50 (above the tool carrying arm) because the elastic tongue piece 100 shown in FIG. stand up). As mentioned above, the tip of the actuating rod 70 is retracted to a position where it does not interfere with the bifurcated portion 62 of the rotary plate 50, so it does not interfere with the primary rotation of the rotary plate 50.

Next, the motor 56 rotates to engage and drive the spur gear 54 formed on the rotary plate 50, rotate the rotary plate 50 in a predetermined direction, and index the tool 30.

That is, by rotating the rotary plate 50, the tool transfer arm 60 with the desired tool 30 mounted thereon moves toward the main shaft 22.
(the position of the tool transport arm indicated by the two-dot chain line in FIG. 3) (tool delivery).

The tool transport arm 60 newly indexed in this way moves to the first rack 88 by reversely biasing the cylinder 84.
．． Under the meshing action of the pinion 90 and the second rack 92,
Following the completely reverse process of FIGS. 6(a) to 6(d), it is rotated counterclockwise and lands at the position shown by the solid line in FIG. 3. As described above, the central axis of the tool 30 attached to the indexed tool transport arm 60 is aligned with the axis of the main spindle 22, and the tool holding member 78 located within the hollow part of the main spindle 22 is open and waiting to receive the pull stud 74 (the tool carrying arm is collapsed downward).

Next, when the motor 42 is reversely energized in the state shown in FIG.
The arbor 30c is inserted into the opening of the tool mounting section 20 (magazine table retracted).

As a result, the pull stud 74 enters the tool holding member 78 that is waiting to be released, and seizing this timing, the suppressing bias against the drawbar 76 is released. Therefore, the compression spring 82 returns elastically and slides the drawbar 76 to the right in the axial direction, and the pull stud 74 is moved by the tool holding member 78.
is clamped (tool clamp). Through this series of operations, indexing and mounting of a new tool are all completed, and machining of the workpiece is started.

Effects As described in detail above, according to the tool changer according to the present invention, a magazine stand equipped with a rotary plate for tool indexing is slidably supported on the spindle head, and the magazine base is slidably supported on the spindle head, and A plurality of tool transfer arms that can rotate in a perpendicular plane are provided on the circumferential surface of the rotary plate at a predetermined distance apart, and rotation of the rotary plate causes any tool transfer arm to face the tool mounting portion of the spindle. After being indexed to the position, the tool carrying arm is rotated by a required angle from its standby position, and a specific tool supported by the tool carrying arm is inserted and guided into the tool mounting portion of the spindle. The tool changing device according to the prior art has a complicated mechanism, but it has a simpler structure than the conventional tool changing device, and it is possible to reduce the manufacturing cost and the number of failures. In addition, since the tool magazine is self-propelled relative to the spindle for tool exchange, there is an advantage that the time required for tool exchange is shortened.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of a machine tool equipped with a tool changer according to the present invention, and Fig. 2 is an enlarged view of the tool changer according to the present invention, in which the magazine table is completely retracted above the spindle head. Figure 3 shows the magazine stand in the fully advanced position on the spindle head.
Fig. 4 is a front view of the rotary plate and spindle head on which many tool transfer arms are mounted, as seen from the left side of Fig. 2, Fig. 5 is an enlarged perspective view of the tool exchange mechanism that forms the gist of the present invention, and Fig. 6 Figures (a) to () are explanatory diagrams showing the process in which the tool transfer arm rotates with respect to the rotary plate. 12... Spindle head 18... Table 20
...Tool mounting part 22...Main shaft 28...
Workpiece 30...Tool 34...Magazine stand 50...Rotary plate 60...Tool transfer arm

Claims (1)

[Scope of Claims] A spindle head (12) that rotatably supports a spindle (22) having a tool mounting portion (20) at one end is connected to a table (18).
) A machine tool that processes a workpiece (28) by reciprocating the workpiece (28) held on the workpiece (28), the axis of the spindle (22) on the spindle head (12). a magazine stand (34) supported so as to be slidable in the direction; a drive member (42, 44, 46) that reciprocates the magazine stand (34) along the sliding direction; and the magazine stand (34). A rotating plate (50
), and tools (30) arranged on the rotating plate (50) in a radial direction centered on the rotational axis, and rotatably supported in a plane including the radial line, each having a tool (30) at one end.
and one of the tool carrying arms (60) is attached to the tool mounting part (22) of the spindle (22).
The rotating plate (20) is moved to a position opposite to the rotary plate (
and an indexing device (54, 56) for rotating the tool (50), and a tool (30) of the tool transfer arm (60) moved to a position facing the tool mounting portion (20) of the main shaft (22). Rotating means (70,
84, 88, 90) A tool changing device for a machine tool, comprising: