JPH044086B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a universal head for machine tools.

Conventional technology Machine tools are now capable of complex control using CNC equipment.

For example, a machine tool such as a vertical machining center has a table that moves in the X and Y directions and a spindle head that moves in the Z direction (up and down), and these can be controlled by a CNC device to make workpiece machining easier. It's getting old.

The machine tool disclosed in JP-A No. 58-77427 has a first pinion at the end of the main shaft, a second pinion that meshes with the first pinion at the middle part of the intermediate shaft, and a third pinion at the end of the intermediate shaft. A fourth pinion that engages with the third pinion is provided in the intermediate part of the spindle, a part for mounting a tool is provided at the tip of the spindle, and the distance between the second pinion and the third pinion is determined by the axial dimension of the intermediate shaft. The distance between the fourth pinion and the part on which the tool is mounted is set smaller than the dimension in the axial direction of the spindle. Then, the movable disc is fixed to the swivel base, and the second
A movable disk is disposed between the pinion and the third pinion, and the movable disk is rotatably disposed on the carriage.

Problems to be Solved by the Invention Let us consider the case where, for example, a rectangular parallelepiped workpiece is grooved using this type of machine tool.

To form grooves on the adjacent first and second surfaces of a workpiece, the workpiece is first fixed on a table with the first surface facing the tool. After lowering the spindle head and cutting a groove on the first surface with a tool, the workpiece is removed from the table. Then, the workpiece is fixed again on the table with the second surface facing the upper tool, and a groove is machined on the second surface using the tool.

In order to carry out such diverse processing, the workpiece must be divided into two parts.
It is necessary to set the table twice or more times, which hinders the improvement of processing efficiency and prevents automation of the work.

The present invention solves the above-mentioned problems and provides a universal head for a machine tool that can machine a workpiece by directing the tool in the vertical direction or horizontal direction, just by setting the workpiece once on the table. purpose.

Means for Solving the Problems The present invention provides a universal head used for a machine tool having a spindle head 11 and a spindle 18 rotatably disposed inside the spindle head 11, in which a universal head is removably attached to one end of the spindle 18. Mounted holder 32
and a first shaft 34 provided integrally with the holder 32.
, the first bevel gear 37 provided at the end of the first shaft 34, and the spindle head 11 in a shape that wraps around the first shaft 34.
a base 25 provided in the base 25; a second bevel gear 44 that meshes with the first bevel gear 37 within the base 25;
Hollow arm 2 rotatably connected to base 25
8, a motor 63 that is fixed to the base and rotates the arm 28, and a second shaft 43 that has the second bevel gear 44 fixed to one end and extends into the arm 28;
A third bevel gear 45 is fixed to the other end of the second shaft 43 within the arm 28, a fourth bevel gear 51 meshes with the third bevel gear 45 within the arm 28, and the fourth bevel gear 51 is fixed to one end. the third shaft 46 and the third shaft 4
6 has a taper support portion 52 on which a tool holder is removably attached, and the rotation center of the arm 28 and the rotation center of the second shaft 43 coincide with each other, and the second bevel gear 44 and the third bevel gear The distance between the gear 45 and the fourth shaft is set equal to the axial dimension of the second shaft 43.
The gist is a universal head for a machine tool characterized in that the distance between the bevel gear 51 and the tapered support part 52 is set equal to the axial dimension of the third shaft 46.

Embodiment FIGS. 1 and 2 show a machine tool 2 equipped with a universal head 1 according to an embodiment of the invention.

This machine tool 2 has a main body 3 of the machine tool, a CNC
It has a device 4 and an operation panel 5.

The main body 3 is a vertical machining center. A first table 7 and a second table 8 are provided on the base 6 of the main body 3. The first table 7 can be moved on the second table 8 in the direction of arrow X in FIG. 1 by a servo motor 9. The second table 8 can be moved on the base 6 in the direction of arrow Y in FIG. 2 by a servo motor 10. The spindle head 11 of the main body 3 can be moved up and down in the direction of arrow Z in FIG. 2 by a servo motor 14 along the rail 13 of the column 12.

The main body 3 also includes an automatic tool changer 15 and a tool magazine 16.

Universal head 1 is shown in FIG. The universal head 1 is set at the lower end of the spindle head 11.

The main shaft 18 is connected to the main shaft head 1 via bearings 19 to 21.
It is rotatably supported within 1. A sleeve 22 and a tapered support portion 23 are attached within this main shaft 18 . A collector 24 is located inside this sleeve 22.
is interpolated.

The base 25 of the universal head 1 has one end 26 connected to the mounting portion 11a of the spindle head 11 with the screw 1.
It is attached via 1b. The base 25 is bent at an intermediate position, and the center axis L1 of the main shaft and the base 2
The central axes L2 of the other ends 27 of 5 intersect at an angle θ1, preferably 45°.

An arm 28 is connected to the other end 27 of the base 25 . That is, the other end 27 of the base 25 is inserted into the space 28a of the arm 28, and the arm 28
One end 29 is engaged with the mounting portion 27a of the other end 27. This arm 28 is rotatable relative to the base 25. This arm 28 is bent at its intermediate portion, and the central axis L2 of one end 29 and the central axis L3 of the other end 30 of the arm 28 form an angle θ.
2. Preferably intersecting at 45°.

Next, each central axis L1 of the base 25 and the arm 28
- Transmission means 31 supported along L3 will be explained.

A holder 32 is attached to the tapered support portion 23 of the main shaft 18.
A tapered portion 32a is fitted therein. Holder 32
The pull stud 33 is fitted into the collet 24 and pulled upward. Holder 32
The main shaft 18 is prevented from rotating via a stopper 11c and a screw 11d. Each central axis of the holder 32 and its shaft 34 coincides with the central axis L1 of the main shaft 18. The shaft 34 is connected to the base 25
It is rotatably mounted within one end 26 of the holder via bearings 35, 36. On the other hand, a shaft 43 is rotatably supported at the other end 27 of the base 25 via bearings 38-42. The central axis of this shaft 43 is the central axis L
It is consistent with 2. Bevel gears 44 and 45 are set at the upper and lower ends of the shaft 43, respectively. A bevel gear 44 and a bevel gear 37 attached to the shaft 34
are located in the space 25a of the base 25 and mesh with each other.

At the other end of the arm 28, a shaft 46 has bearings 47 to 5.
It is rotatably supported via 0. This shaft 46
The central axis of coincides with the central axis L3. axis 46
A bevel gear 51 is attached to one end. The bevel gear 51 and the bevel gear 45 are located within the space 28a of the arm 28 and mesh with each other. The taper portion 54 of the tool holder 53 is fitted into the taper support portion 52 of the shaft 46 . The pull stud 55 of the tool holder 53 is secured by biasing means 56 provided within the shaft 46.
This biasing means 56 includes a spring 57 and a ball 58.
Consisting of The tool holder 53 is prevented from rotating with respect to the shaft 46 by a screw 59 and a stopper 60. Furthermore, a tool 61 is attached to the tool holder 53. This tool is, for example, an end mill.

Next, the driving means 62 will be explained. Servo motor 6
3 is attached to the other end 27 of the base 25. A worm 65 is attached to the output shaft 64 of the servo motor 63. On the other hand, at one end 29 of the arm 28,
A worm wheel 66 is attached. The worm wheel 66 and the worm 65 mesh with each other. By rotating the servo motor 63, the arm 28 can be rotated in the direction of arrow R about the central axis L2.

As the servo motor 63 and the servo motors 9, 10, and 14 already mentioned, for example, a DC servo motor can be adopted. Further, the main shaft 18 can be rotated by a motor 18a shown in FIG.

Next, a control system for the servo motors 63, 9, 10, and 14 will be explained with reference to FIG. 4.

The CNC device 4 has a built-in central processing unit (hereinafter referred to as CPU) 67, as shown in FIG.

The NC program on the NC tape 76 is read by a tape reader 77, for example, on a floppy disk 79.
address/data bus AD on the floppy disk
It is temporarily stored via .

The servo system 68 that controls the servo motor 63 is
It is connected to the CPU 67 via an address/data bus AD. In addition, each servo system 69 to 71 that controls the servo motors 9, 10, and 14 is also operated by a CPU.
It is connected to.

The servo systems 68 to 71 are well known and have the same configuration, and the servo system 68 will be explained as a representative. Note that the servo system 69 includes the reference numeral 72 of the servo system 68.
The same reference numerals 172 to 175 and 180 to 182 are given to parts corresponding to 75 and 80 to 82, and illustration of the configurations of the servo systems 70 and 71 is omitted to simplify the drawing.

The position control section 72 includes a pulse shaping/direction determining circuit 73, a deviation counter 74, and a D/A converter 75.

The NC program is input from the floppy disk 79 to the CPU 67. The CPU 67 is configured to send a movement command pulse 72a and a command code 72b that determines the rotational direction of the servo motor 63 to the pulse shaping/direction determining circuit 73 based on this NC program.

A speed control section 80 is connected to a subsequent stage of the position control section 72 . The speed control section 80 includes a servo motor 6.
3 is connected. A tacho generator 81 and a pulse generator 82 are connected to the output shaft of the servo motor 63.

The tacho generator 81 is for detecting the rotation speed of the servo motor 63. The output voltage of the tachogenerator 81 is proportional to the rotation speed, and the polarity of the output voltage is determined by the rotation direction of the servo motor 63.

The pulse generator 82 is a servo motor 63
Detects the amount of rotational movement (rotation angle). The number of pulse outputs from the pulse generator 82 is proportional to the amount of rotational movement, and the polarity of the pulse output is determined by the direction of rotational movement of the servo motor 63.

The tachogenerator 81 is connected to the speed control section 80. The pulse generator 82 is connected to a pulse shaping/direction determining circuit 73.

The deviation counter 74 outputs the difference between the number of movement command pulses 72 and the number of movement feedback pulses fed back from the pulse generator 82 (saved pulses) as an error output voltage. The magnitude of this output voltage is proportional to the magnitude of the difference, and the polarity of the output is determined by the polarity of the difference.

The error output voltage, which is this digital value, is the D/A
A converter converts it into an analog value and supplies it to the speed control section 80 as a speed command voltage.

The speed control section 80 compares the speed feedback voltage from the tacho generator 81 and the speed command voltage. The voltage difference between the two is amplified. The speed of the servo motor 63 is controlled so that the voltage difference between the two approaches zero.

When the servo motor 63 starts rotating, the movement command pulse 72a is input to the deviation counter 74 via the pulse shaping/direction determining circuit 73, and the counter 74 integrates the pulses. This droop pulse is converted into a speed command voltage by the D/A converter 75 and inputted to the speed control section 80.

Therefore, the servo motor 63 starts rotating.
When the servo motor 63 starts rotating, pulses proportional to the rotation angle are generated from the pulse generator 82 and input to the deviation counter 74 . As a result, the accumulated pulses in the deviation counter 74 are subtracted.

If the movement command pulse 72a is continuously input, the servo motor 63 rotates continuously and the deviation counter 74 maintains a constant number of droop pulses. The rotation speed of the servo motor 63 is proportional to the frequency of the movement command pulse 72a.

When the input of the movement command pulse 72a stops, the servo motor 63 rotates until the residual pulse of the deviation counter 74 becomes zero, and then stops.

4 to 6, for example, the arm 28 moves from the state shown in FIG. 5 relative to the base 25 based on the number of movement command pulses 72a.
It can be rotated 180 degrees to change to the state shown in FIG.

Servo motors 9, 10 of servo systems 69-71,
14 is similarly controlled. That is, the spindle head 11 and the tables 7 and 8 can each be moved to a predetermined position based on the movement command pulse and the command code.

By the way, the main shaft motor 18a is rotated at a predetermined rotation speed according to a command from the sequence control section 83. This sequence control section 83 is connected to an interface 84.
It is connected to the address/data bus AD of the CPU 67 via. Each servo motor 9, 10, 1
4, 63 and the main shaft motor 18a can be moved separately according to instructions from the CPU 67. Further, the operation panel 5 is connected to a CPU 67, a sequence control section 83, and a limit switch (not shown) of the main body 3 via a cable 17 (see FIG. 2).

Next, the case where, for example, grooves are formed on the side surface W1 and the top surface W2 of the workpiece W, respectively, based on the NC program will be explained with reference to FIGS. 1 to 3, and FIGS. 5 and 6.

First, as shown in FIGS. 1, 2, and 5, the workpiece W is set on the first table 7 via the stopper 85. The automatic operation start button on the operation panel 5 is pressed and the first table 7 is moved in the direction of the arrow X by the servo motor 9. Then, the second table 8 is moved in the direction of arrow Y by the servo motor 10. In this way, the workpiece W is positioned at a predetermined position.

As shown in FIGS. 1, 3 and 5, the tool 61 of the universal head 1 is oriented horizontally to the left in the drawings.

Next, the spindle head 11 is lowered in the direction of arrow Z by the servo motor 14, so that the tool 61 of the universal head 1 and the side surface W1 face each other.

Rotate the main shaft motor 18a to turn the tool 61,
Move the first table 7 to the right in FIG.
1 into the side surface W1 of the work W at a predetermined depth. Then, the second table 8 is moved in the direction of arrow Y (rightward) in FIG. 2 to form a groove 86 in the side surface W1.

Next, the first table 7 is moved to the left in FIG. 5 to remove the tool 61 from the workpiece W, and
Raise the spindle head 11. Note that the workpiece W remains set on the first table 7.

Then, as shown in FIG. 6, a servo motor 63
is actuated to rotate the arm 28 with respect to the base 25, for example, clockwise by 180°. The tool 61 therefore faces vertically downward.

Move the first table 7 and the second table 8,
The workpiece W is positioned at a new predetermined position, the spindle head 11 is lowered, and the tool 61 is cut into the upper surface W2 of the workpiece W to a predetermined depth. Then, move the second table 8 in the direction of arrow Y (rightward) in FIG.
A groove 87 is formed in 2.

In this way, by simply setting the workpiece W on the first table 7 and rotating the arm 28 of the universal head 1 by 180 degrees, two sides of the workpiece can be machined by directing the tool 61 in the vertical and horizontal directions. .

By the way, the servo motor is not limited to a DC servo type, but may be an AC servo type. Further, a stepping motor may be used instead of the servo motor.

Furthermore, if the angles θ1 and θ2 at which the central axes L1, L2, and L3 intersect are set to 45°, the tool 61 can be applied perpendicularly to the top and side surfaces of the rectangular parallelepiped workpiece. However, if a universal head with angles θ1 and θ2 set to other than 45° is prepared, the tool 61 can be brought into contact with the upper surface of the workpiece at a desired angle.

Effects of the Invention As explained above, according to the present invention, by simply setting the workpiece on the table once, the workpiece can be machined by directing the tool in the vertical direction or the horizontal direction. In addition, the entire universal head can be easily attached to and detached from the spindle head of a machine tool.

Also, compared to the machine tool of JP-A No. 58-77427 mentioned above, the second bevel gear 44 and the taper support portion 52 are
You can set a large distance between the

[Brief explanation of drawings]

Fig. 1 is a front view showing a machine tool equipped with a universal head according to the present invention, Fig. 2 is a side view of the machine tool shown in Fig. 1, and Fig. 3 is a sectional view of the universal head shown in Fig. 1. , FIG. 4 is a diagram showing a servo system, CNC device, etc. used in the machine tool of FIG. 1, and FIGS. 5 and 6 are diagrams showing an example of machining a workpiece by the universal head shown in FIG. 1. 1...Universal head, 2...Machine tool,
4... CNC device, 9, 10, 14, 63... Servo motor, 18... Main shaft, 25... Base, 28
... Arm, 31 ... Transmission means, 61 ... Tool,
62...Driving means.

Claims (1)

[Claims] 1 In a universal head used for a machine tool having a spindle head 11 and a spindle 18 rotatably arranged inside the spindle head 11, a holder 32 is detachably attached to one end of the spindle 18, and the holder 32 and The first shaft 34 and the first shaft 3 are integrally provided.
4, the first bevel gear 37 provided at the end of the
A base 25 is provided on the spindle head 11 so as to wrap around the shaft 34, and the first bevel gear 3 is disposed within the base 25.
7, a hollow arm 28 rotatably connected to the base 25, a motor 63 fixed to the base and rotating the arm 28, and the second bevel gear 44 fixed to one end. and a second shaft 43 extending within the arm 28 and a third bevel gear 4 fixed to the other end of the second shaft 43 within the arm 28.
5, a fourth bevel gear 51 that meshes with the third bevel gear 45 within the arm 28, a third shaft 46 with the fourth bevel gear 51 fixed to one end, and a tool holder removably attached to the other end of the third shaft 46. Taper support part 5 attached to
2, the center of rotation of the arm 28 and the second axis 43
The rotation centers of the second bevel gear 44 and the third bevel gear 45 are set equal to the axial dimension of the second shaft 43, and the fourth bevel gear 51
A universal head for a machine tool, characterized in that the distance between the third shaft 46 and the tapered support portion 52 is set equal to the axial dimension of the third shaft 46.