JPS5927308B2 - Automatic tool changer for machine tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic tool changer that can be mainly applied to a machine tool having a vertical spindle, and utilizes the axial movement function of the spindle to change a turret-type machining center, This can be done on any single-axis machine.

A typical vertical machine tool consists of a spindle and spindle head that move up and down, and a table and saddle that move left and right and back and forth.

On the other hand, automatic tool changers are essentially equipped with a rotatable magazine for storing a large number of tools to be replaced, and can be divided into two types: those with and without tool transfer arms.

A device having a tool transfer arm supports a tool magazine at a position apart from the main shaft, and has the above-mentioned arm that pivots between the tool magazine and the main shaft,
Tools attached to the spindle are removed through extremely complex movements such as expansion and contraction, vertical movement, etc., transported back to the tool magazine, removed the tool to be replaced from the magazine, and transported to and mounted on the spindle. Disadvantages are that the time required for replacement is long and that the device structure is complicated and expensive.

In a method that does not use a tool transfer arm, a tool magazine is installed close to the spindle, and tools are exchanged directly between the tool magazine and the end of the spindle, which reduces the time required for tool exchange. Because the tools stored in the table cover the table or the workpiece on the table, there is an operational defect that interferes with the measurement of tools and workpieces, and the operation of attaching and removing force objects.

The purpose of the present invention is to eliminate the above-mentioned defects, and by attaching a tool magazine to the tip of a rotating arm, the tool magazine is moved directly under the spindle by the rotating arm only when changing tools, and the tool magazine is moved directly under the spindle when the machine is cutting. Measurement of tools, loading and unloading of workpieces on the table, measurements, etc. are performed after the tool magazine is moved to the standby position using a rotating arm.An example of this is as follows. be.

FIG. 1 is a schematic plan view common to the first and second embodiments of the present invention, in which 1 is a machine tool, 1a is a table, 1b is a vertical guide for the spindle head 2, 3 is a spindle, and 22.22a is a Swivel arm, 23 is a vertical axis forming the center of rotation of the arm, 36.36
a is a tool magazine.

The above spindle head was shown as a single-shaft type, but 6 to 8
You can also make it into a crette shape that holds the main axis of the book.

2 to 7 show a first embodiment of the present invention, in which a chuck mounting screw 4 is provided at the center of a spindle 3 rotatably supported inside a spindle head 2.

The spindle 3 moves up and down along with the spindle head 2 at an arbitrarily set stroke to perform operations such as drilling holes in the workpiece, and when exchanging tools, moves between an exchanging position a and a raised position as shown in FIG. 3.

Reference numeral 6 denotes a known non-stop chuck in which a mounting head 8 is inserted from the end face of the main shaft 3 and secured by tightening with the mounting screw 4, and a key groove 9a formed in the collar 9 is fitted into the key 5 stuck to the end face of the main shaft 3. Apply a rotation stopper.

This non-stop chuck 6 consists of a chuck body 7 including a mounting head 8 and a flange 9, and an outer cylinder 13.The mounting head 8 has a mounting shaft 10 formed below the flange 9. The lower end is expanded into a tapered shape, and a truncated cone-shaped mounting hole 11 is bored from the lower end surface, and the upper and lower two stages of retaining balls 12 that protrude outward from the outer peripheral wall or protrude into the mounting hole 11 are freely movable. Fit it into.

Further, the outer cylinder 13 is fitted onto the outer periphery of the mounting shaft portion 10 so as to be freely movable in the axial direction, and when moved downward by the spring 15 as shown in FIG. As shown in FIG. 5, the engaging ball 12 is released from being pushed out when the blade is moved slightly toward the upper edge, and a flange 14 is formed at the upper end thereof.

The tool holder 16 is provided with a truncated conical shank 17 at its upper end to be inserted into the mounting hole 11, and a tool 21 at its lower part.
A fastening ring 19 is provided on the outer periphery of the shank 17, and an oval hole 18 is provided on the outer periphery of the shank 17, and movement in the rotational direction is restrained by the engagement ball 12 in the upper stage, and movement in the axial direction is restrained by the engagement ball 12 in the lower stage. An annular groove 20 is formed on the outer periphery of the fastening ring 19.

Reference numeral 22 denotes a swing arm supported on the machine tool 1 by a vertical shaft 23 so as to swing between a tool change angle I and a standby angle H as shown in FIG. The pivoting movement is controlled by engaging the rack rod 26.

A vertical rotating shaft 27 to which a grooved pulley 28 is fixed is provided at the tip of the swing arm 22, and a tool magazine 36 made of a circular plate is fixed to the lower end. A belt 3 is installed between the groove pulley 30 fixed to the output shaft and the groove pulley 28.
1 to act as a rotating device for the tool magazine 36, and further to control the lowering and raising of the positioning pin 34, which forms a stop angle indexing device, on a bracket 32 that wraps around the circumference of the rotating shaft 27 and is fixed to the swing arm 22. A small cylinder 33 that controls the movement of the lever 43 and a small cylinder 35 that controls the rise and fall of the two-pronged lever 43 are installed, and a plurality of index holes 37 (FIG. 7) are formed in the tool magazine 36 around the rotating shaft 27 using the positioning pin 34. A stop angle indexing device is provided at equal intervals so as to correspond to the lower part of the tool exchange angle I, and a stop angle indexing device is provided at the peripheral edge thereof. The same number of tool storage grooves 38 as the index holes 37 are provided at equal intervals on the circumferential surface of the annular groove 20 of the tool holder 16 attached by the chuck 6 so as to fit through the openings 39. A spring 40 that holds the tool holder 16 stored along one side groove edge of the lower surface of the groove 38
Install.

An index switch 41 supported by the pivot arm 22 is attached to the upper end of the rotating shaft 27.

Further, the outer periphery of the tool magazine 36 is covered with a circular cover 42 attached to the rotating arm 22 to prevent stored tools from flying out due to excessive centrifugal force. Opening port 39 of groove 38
Then, the portion corresponding to the tip of the forked lever 43 is removed.

The aforementioned two-pronged lever 43 always fits into the lower surface of the flange 14 on the outer cylinder 13 of the non-stop chuck 6 at the exchange position a when the pivot arm 22 rotates to the tool exchange angle with the piston of the small cylinder 35 being lowered. be consistent.

In the first embodiment, the spindle 3 is moved by a motor (
(not shown) is lowered to the tool exchange position a (Fig. 4) and stopped, and the swing arm 22, which is at the standby angle ■, is rotated to the tool exchange angle I by driving the cylinder 25 and moving the rack rod 26 in one direction. As shown in FIG. 4, the empty tool storage groove 38 in which no tool holder 16 is stored is inserted into the annular groove 20 of the tool holder 16 to store it so that it cannot move up and down, and at the same time, the two-pronged lever 43 is held in the non-stop chuck. The small cylinder 35 is then immediately driven to raise the piston and the two-pronged lever 43.

At this time, the outer cylinder 13 rises as shown in FIG. 5 to release the engagement ball 12 from being forced into the mounting hole 11.
The tool holder 16, which had been clamped to prevent axial and rotational movement within the mounting hole 11 of the mounting head 8 by receiving the pawl 12 in the hole 18 of the truncated conical shank 17 and the annular groove 18a, is in a free state. Nari tool magazine 36
It is pushed and held by the spring 40 only by the tool storage groove 38.

At this time, when the main spindle 3 is raised to the raised position by the driving of the moving motor, the tool 44 and the rudder 16 remain in the tool magazine 36, and the top chuck 6 rises together with the main spindle 3.
Gaisho 13 is pushed down by spring 15 (Figure 6)
.

Therefore, at this time, the small cylinder 33 is driven to pull out the positioning pin 34 upward from the index hole 37, and the geared motor 29
By driving ■, the tool magazine 36 is rotated via the belt 31, and the tool storage groove 38 storing the tool holder 16 of the tool 21 to be replaced is moved to directly below the main shaft 3 in the raised position, and the caddy moke 29 is stopped. The movement is confirmed by the indexing switch 41, and the small cylinder 33 is driven in the opposite direction, and the positioning pin 34 is lowered to cause the indexing hole 37 to fit into the indexing hole 37. Then, the main shaft 3 is moved to the replacement position by driving the moving motor. Descend to a.

At that time, the outer cylinder 13 brings the flange 14 into contact with the upper surface of the two-pronged lever 43 and moves upward while compressing the spring 15.
In addition, the chuck body 7 is lowered while receiving the shank 17 of the tool holder 16 into the mounting hole 11, so after confirming the lowering, the small cylinder 35 is driven to lower the two-pronged lever 4.
Lower 3.

At this time, the outer cylinder 13 is pushed down by the spring 15 and pushes out the upper and lower two engagement poles 12 into the mounting hole 11. At the same time, the machine tool's low-speed rotation function causes the main shaft 3 to be pushed out.
and the chuck body 7 are rotated at a low speed to cause the engagement ball 12 to rotate, thereby moving the upper engagement ball 12 into the hole 1.
8, fit the lower engagement ball into the annular groove 18a, clamp the shank 17, and move the tool holder 16 to the main shaft 3.
(Figure 4).

At step 5, the swing arm 22 is driven by the cylinder 25 to swing to the standby position (3), and the tool magazine 36 is removed from the lower surface of the spindle 3, completing one automatic tool exchange.

8 to 10 show a second embodiment of the present invention, in which a main spindle 3 rotatably supported by a main spindle head 2 is provided with a tool change angle indexing device 51, and a tool change angle indexing device 51 is installed inside the main spindle 3, and a tool holder is moved in the axial direction. The tool holder 71 has a conical shank 72 in a tapered mounting hole 64 formed from the end surface of the main shaft 3.
A known device is used in which the engaging neck portion 74 at the head end is clamped by the clamping device 61.

The main shaft 3 has a rotating gear 56 that meshes with a gear 55, and the tool exchange angle indexing device 51 has an indexing groove 53 (inverted V-shaped The index pin 54 rises from the position shown by the chain line and fits into the index groove 53 as shown by the solid line.

When changing tools, the main shaft 3 stops, the rotating gear 56 is raised by the gear shift device, and the main shaft 3 becomes free.
Next, when the indexing pin 54 rises and enters the lower widening part of the indexing groove 53, the main shaft 3 freely rotates to the right or left, and at the same time the indexing pin 54 engages the upper end of the indexing groove 53, the indexing occurs. The range of vertical movement is set so that it is held at an angle and moves between the exchange position a and the raised position.

The attachment hole 64 of the tool holder is formed at the lower end of the center hole 62 of the main shaft 3, and a large diameter hole 63 for the purpose of releasing the clamp is provided at the boundary portion thereof.

The tool holder γ1 includes a retaining shaft 7 having an engaging neck portion 74 at the head end of a conical shank 72 that fits tightly into the mounting hole 64.
3 protrudes, and the engaging neck portion 74 enters through the large diameter hole 63 to the center hole 62, and within the center hole 62 is a clamp shaft 65 whose vertical movement is controlled by a cylinder or the like (not shown). is loosely inserted into the shaft 65, the protrusion on the outside of the lower end is inscribed in the hole wall of the center hole 62, and the claw 67 on the inside of the lower end is bitten into the engagement neck 74 to lift the tool holder 11. Install the elastic clamp finger 66.

The clamp shaft 65 descends to move most of the clamp finger 66 into the large diameter hole 63, whereby the clamp finger opens the claw 66 by its own elasticity and releases the clamp on the tool holder 71. , the clamp shaft 65 and the clamp finger 66 constitute the Franz device 61 described above.

A retaining key 68 is protruded from the end face of the main shaft 3.

The key 68 always assumes a certain angle, which will be described later, whenever the tool change angle indexing device 51 is activated.

The conical shank 72 of the tool holder 71 is fixed by fitting a collar 75 into the part that protrudes from the lower blade when it is fitted into the mounting hole 64 of the main spindle 3, and the engaging key 68 of the main spindle 3 is fixed to this in the upper part.
A key groove 76 is provided in which the key groove 76 is fitted.

The configuration of each part described above is well known. The swing arm 22a and the tool magazine 36a rotatably supported at its tip are basically the same as the swing arm 22 and the tool magazine 36 of the first embodiment, except that the small cylinder 35 and the two-pronged lever 43 are omitted. Instead, an angular retainer 77 consisting of a roller that fits into the lower part of a key groove 76 formed in the collar 75 of the tool holder 71 is attached to the groove edge of each tool storage groove 38 of the tool magazine 36a as shown in FIG. Install.

Other parts that are the same as those in the first embodiment are given the same reference numerals.

To explain the operation of the second embodiment, when changing a tool, the tool changing angle indexing device 51 indexes the angular phase of the engagement key 68 of the main shaft 3 as described above so that it is at a predetermined angle, and It is lowered to the replacement position a (Fig. 8) and stopped.

At that time, the key groove 76 provided in the collar 75 of the tool holder 71
is an angle that matches the engager 7T provided on the groove edge of the corresponding tool storage groove 38 of the tool magazine 36a, so the swing arm 22a is pivoted from the standby angle ■ to the tool exchange angle I, and the main shaft 3 Tsuba 7 of tool holder 71 attached to
The empty tool storage groove 38 of the tool magazine 36a is located on the lower surface of the tool magazine 36a.
is inserted through the opening 39 to house the holder 71, and at the same time the engaging element 77 is inserted into the key groove 7 in which the engaging key 68 is engaged.
6 into the lower part of the tool holder 71 as shown in the figure.
stop moving around.

Thereafter, the clamp shaft 65 descends within the center hole 62, opens the clamp finger 66 with its own elasticity, releases the grip on the engagement neck 74, and then the spindle head 2 and the spindle 3 move toward the raised position. When the ascent starts, the tool holder 71
is left on the tool magazine 36.

Thereafter, the upward movement of the positioning pin 34, the rotation of the tool magazine 36a, and the downward fitting of the positioning pin 34 into the index hole 37 are controlled in the same order as described in the first embodiment, and the tool holder of the tool to be replaced is controlled. 71 directly below the spindle 3, the spindle head 2 and spindle 3 are lowered to the replacement position a, and the conical shank 72 of the tool holder 71 is relatively inserted into the mounting hole 64 of the large diameter hole of the retaining shaft 73. 63, causing relative penetration between the pawls 67 of the elastic clamping fingers 66, and as the pawls 67 accommodate around the engagement neck 74, the clamping shaft 65 is raised and clamped as shown in FIG. .

At that time, the engagement key 68 fits into the keyway 16 of the collar 75 to prevent rotation.

After the above operations are completed, the swing arm 22a and the tool magazine 36a are turned to the standby angle.

The automatic tool change operation according to the fixed procedure of the first and second embodiments described above is, in principle, performed by program control with limit switches placed at the respective operating poles, but this is not applicable to single-axis machine tools. In some cases, since the scale is small, semi-automatic control can be used.

The raising and lowering of the main shaft 3 is an inherent function of a machine tool controlled by a moving motor, and as in the first embodiment, the main shaft 3 is slowed down to engage the upper engagement ball 12 with the hole 18 of the tool boulder 16. The same applies to the rotation, angle indexing device 51, clamping device 61, etc. of the second embodiment.

One of the features of the present invention is that the various motion ranges described above are set among the configurations and functions of the spindle head 2, spindle 3, and other machine tools.

As clarified by the description of the above embodiments, in the first aspect of the present invention, a tool magazine is rotatably supported at the tip of a swing arm that moves between a tool exchange angle and a standby angle. A rotating device and a stop angle indexing device are provided between the swivel arm and the tool magazine, and the tool magazine uses the rotating device and the stop angle indexing device to rotate one of the many tool storage grooves at the tool exchange angle of the main spindle. Corresponds directly below,
When rotating together with the rotating arm from a standby angle to a tool exchange angle or vice versa, the tool accommodating groove is inserted into the circumferential surface of the tool holder attached to the main shaft through the open opening, or escapes from the circumferential surface. There is no risk of the tool holder accidentally falling out of the tool storage groove, and there is no need for the swing arm to have a complex structure with multiple motions like the conventional tool transport arm, so the tool does not fall off. Since the main control is performed by the axial movement of the machine tool spindle head, the tool magazine itself has the advantage of being easily configured, and this invention also provides a device for automatic tool exchange from the machine tool table except when changing tools. can be removed so that loading, removing, and other operations of workpieces will not be hindered at all.

Further, the second invention has a specific configuration that simplifies implementation when a non-stop ball chuck is used in the first invention, and the third invention has a structure in which mounting and dismounting are controlled by a clamp device on the spindle side. The present invention has the advantage of having a specific configuration that simplifies implementation when using a tool holder, and eliminates the complexity of the respective automatic tool change operations.

[Brief explanation of the drawing]

The accompanying drawings show embodiments of the present invention, FIG. 1 is a schematic plan view, FIGS. 2 to 7 show the first embodiment, and the second embodiment is shown in FIG.
The figure is a partially cutaway plan view of the main part, FIG. 3 is a cross-sectional view taken along the line A-A in FIG. FIG. 2 is a developed view cut along line B-B. 8 to 10 show a second embodiment, FIGS. 8 and 9 are partially cutaway front views of essential parts, and FIG. 10 is a plan view of a part of the tool magazine. 1...Machine tool, 2...Spindle head, 3.
...Main shaft, a...-exchange position, b...
・Rising position, 6...Nonstop chuck, 7
...Chuck body, 11...Mounting hole,
12... Engagement ball, 13... Outer cylinder,
14°゛°°°flange, 15...spring, 16
...Tool holder, 17...Truncated conical shape 18...Hole, 18a...Annular groove, 20...Annular groove , 21...tools,
22... Swivel arm, 27... Rotating shaft, 28... Groove pulley, 29... Geared motor, 30... Groove pulley, 31・・・・・・
・■Belt, 34...Positioning pin, 36...
...Tool magazine, 37... Index hole, 38
......Tool storage groove, 39...Opening mouth, 4
3... Two-pronged lever, 51... Tool exchange angle indexing device, 61... Clamping device, 65...
... Clamp shaft, 66 ... Elastic clamp finger, 68 ... Engagement key, 71 ...
...Tool holder, 72...Conical shank,
73...--Engagement shaft, 76...Keyway, 7
7... Engagement.

Claims (1)

[Claims] 1. A tool magazine is rotatably supported at the tip of a swing arm that moves between a tool exchange angle and a standby angle, and a rotation device and a stop angle for the tool magazine are provided between the swing arm and the tool magazine. An indexing device is installed, and the tool magazine has a number of tool storage grooves that are aligned so that when the swivel arm rotates to the tool exchange angle, the tool holder attached to the main shaft of the machine tool fits into the tool holder from the open opening on the circumference. The tool attachment/detachment is performed by the movement of the spindle head, which is provided with a tool chuck or tool clamp device that is provided corresponding to a plurality of indexing angles by the stop angle indexing device and that releases and fixes the tool holder by moving in the axial direction. An automatic tool changer for a machine tool, characterized in that it is configured to perform main control. 2. In the device according to claim 1, the device is mounted on the chuck body and pushes the engagement ball into the tool holder mounting hole as it moves due to the spring force, and releases the extrusion of the retaining ball as it moves against the spring force. A ball-type non-stop chuck with a tube (spindle head) is attached to the rotating arm, and the tool storage groove of the tool magazine is fitted into the circumferential surface of the chuck holder, and at the same time a two-pronged chuck is fitted around the outer cylinder of the chuck. An automatic machine tool characterized in that a lever is installed so as to be movable in the axial direction of the outer cylinder, and the two-pronged lever controls the movement of the outer cylinder to assist in attachment and detachment of the tool holder. Tool changer. 3. The device according to claim 1, comprising: a tool exchange angle indexing device; a clamping device that moves in the axial direction to control clamping and unclamping of the tool holder;
The main shaft is provided with a locking key on the end surface, and the tool holder is provided with a flange with a key groove for receiving the engagement key when inserted into the main shaft. An automatic tool changer for a machine tool, characterized in that it is provided with an angular engagement element that fits into the keyway.