JPH0350652B2 - - Google Patents

Description

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

Conventional technology Machine tools are CNC (Computer Numerical)
Control) devices allow for complex control.

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 (vertical direction) so that workpieces can be easily machined. these are,
Controlled by CNC equipment.

Problems to be Solved by the Invention When using this type of machine tool, for example, when machining a linear groove on the first surface of a rectangular parallelepiped workpiece and machining a circular groove on the second surface adjacent to the first surface. think of.

First, the workpiece is fixed on a table with its first surface facing the tool above. Lower the spindle head, move the table horizontally, and cut a straight groove on the first surface with a tool. Then, raise the spindle head once.

Next, the workpiece is removed from the table and fixed again so that the second surface faces the tool.
Then, the spindle head is lowered, the X and Y tables are moved, and a circular groove is machined on the second surface using a tool.

In order to perform such a variety of machining, the workpiece must be set on the table at least twice.
This hinders the improvement of machining work efficiency and makes it impossible to automate the work.

Purpose of the Invention The purpose of the present invention is to provide a universal head for a machine tool that solves the above problems and is capable of machining curved or straight grooves on a workpiece by setting the workpiece once. shall be.

Summary of the Invention This invention connects one end of the first arm to the spindle head side, and the first arm connects the spindle head to the spindle head or the first arm.
The arm can be rotated by a predetermined angle around the central axis of one end of the arm by a first driving means, the central axis of the other end of the first arm intersects the central axis of the main shaft at a predetermined angle, and the other end of the first arm is connected to one end of a second arm, and the second arm is driven at a predetermined angle by a second driving means around the central axis of the other end of the first arm or the central axis of one end of the second arm. The center axis of the other end of the second arm intersects the center axis of the other end of the first arm at a predetermined angle, and the transmission means is rotatable along each center axis from the inside of the first arm to the inside of the second arm. is supported, one end of the transmission means is connected to the main shaft, and a tool is set at the other end of the transmission means on the other end side of the second arm, so that the tool can be rotated via the transmission means by rotation of the main shaft. The main point of this book is the universal head for machine tools, which has a unique configuration.

Means to solve problems See Figure 3.

One end 26 of the first arm 25 is connected to the spindle head 11 side. The first arm 25 is rotatable by a first driving means 91 relative to the spindle head 11 by a predetermined angle around the main shaft 18 of the spindle head 11 or the center axis L1 of one end of the first arm. A central axis L2 passing through the other end 27 of the first arm 25 intersects with the central axis L1 of the main shaft 18 at a predetermined angle θ1.

A second arm 28 is attached to the other end 27 of the first arm 25.
Connect one end 29 of the. The second arm 28 is rotatable by a predetermined angle relative to the first arm 25 by a second driving means 62 around the central axis L2 of the other end 27 of the first arm 25 or one end of the second arm 28.

The center axis L3 of the other end 30 of the second arm 28 is the first
A predetermined angle θ with the central axis L2 of the other end 27 of the arm 25
2, and from inside the first arm 25 to the second arm 2
Transmission means 31 along each central axis within 8
is supported.

One end of the transmission means 31 is connected to the main shaft 18 and is located on the other end 30 side of the second arm 28.
1, a tool 61 is set at the other end. The tool 61 can be rotated by the rotation of the main shaft 18 via the transmission means 31.

Operation By operating the servo motor 92 of the first drive means 91, the first arm 25 can rotate by a predetermined angle with respect to the spindle head 11. and second driving means 62
By operating the servo motor 63, the second arm 28 can rotate by a predetermined angle with respect to the first arm 25.

Therefore, by rotating the main shaft 18 while directing the tool 61 of the second arm 28 horizontally or vertically, it is possible to machine a curved or straight groove on the workpiece.

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 90 of the universal head 1 has one end connected to the mounting portion 11a of the spindle head 11 with a screw 11b.
It is attached via.

One end 26 of the first arm 25 is connected to the other end of the base 90. One end 26 of the first arm 25
is engaged with the mounting portion 90a of the base portion 90. This first arm 25 is rotatable relative to the base 90.

The first arm 25 is bent at an intermediate position, and the center axis L1 of the main shaft and the other end 2 of the first arm 25 are bent at an intermediate position.
The central axes L2 of 7 intersect at an angle θ1, preferably 45°.

The other end 27 of the first arm 25 has a second arm 2
8 are connected. That is, the second arm 28
The other end 27 of the first arm 25 is inserted into the space 28a, and one end 29 of the second arm 28 is inserted into the other end 27.
It is engaged with the mounting part 27a of. This second arm 28 is rotatable relative to the first arm 25. This second arm 28 is bent at its middle part, and the central axis L2 of one end 29 and the central axis L3 of the other end 30 of the second arm 28 are at an angle θ2,
Preferably they intersect at 45°.

Next, the transmission means 3 supported along each central axis L1 to L3 of the first arm 25 and the second arm 28
1 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 has bearings 35a, 36a, 3 within one end 26 of the first arm 25.
It is rotatably attached via 5 and 36. On the other hand, a shaft 43 is rotatably supported at the other end 27 of the first arm 25 via bearings 38-42.
The central axis of this shaft 43 coincides with the central axis L2. At the upper and lower ends of the shaft 43 are bevel gears 44 and 45.
are set respectively. The bevel gear 44 and the bevel gear 37 attached to the shaft 34 are located in the space 25a of the first arm 25 and mesh with each other.

A shaft 46 is attached to a bearing 47 at the other end of the second arm 28.
It is rotatably supported via ~50. The central axis of this shaft 46 coincides with the central axis L3. A bevel gear 51 is attached to one end of the shaft 46. The bevel gear 51 and the bevel gear 45 are located within the space 28a of the second arm 28 and mesh with each other. The tapered support portion 52 of the shaft 46 includes
A tapered portion 54 of the tool holder 53 is fitted. The pull stud 55 of the tool holder 53 is secured by biasing means 56 provided within the shaft 46. This biasing means 56 consists of a spring 57 and a ball 58. The tool holder 53 has a screw 5
9 and a stopper 60 prevent the shaft 46 from rotating. Furthermore, a tool 61 is attached to the tool holder 53. This tool is, for example, an end mill.

Next, the first driving means 91 will be explained. A servo motor 92 is attached to the other end of the base 90. A worm 93 is attached to an output shaft 95 of the servo motor 92. At one end 26 of the first arm 25,
A worm wheel 94 is attached. The worm wheel 94 and the worm 93 mesh with each other. By rotating the servo motor 92, the first arm 25 can be rotated in the direction of arrow P about the central axis L1.

Next, the second driving means 62 will be explained. The servo motor 63 is attached to the other end 27 of the first arm 25. A worm 65 is attached to the output shaft 64 of the servo motor 63. On the other hand, a worm wheel 66 is attached to one end 29 of the second arm 28. This worm wheel 66 and worm 65
are engaged. By rotating the servo motor 63, the second arm 28 can be rotated in the direction of arrow R about the central axis L2.

The servo motors 63, 92 and the servo motors 9, 10, 14 already mentioned may be, for example, DC servo motors. Further, the main shaft 18 can be rotated by a motor 18a shown in FIG.

Next, servo motors 63, 92, 9, 10, 1
The control system of No. 4 will be explained with reference to FIG.

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. Also, servo motors 9, 10, 14,
Each servo system 69 to 71, 96 that controls the
It is also connected to the CPU.

The servo systems 68 to 71 and 96 are well known and have the same configuration, and the servo system 68 will be explained as a representative. In addition, in the servo system 96, the same symbols 172 to 175 and 180 to 182 are written in the parts corresponding to the symbols 72 to 75 and 80 to 82 of the servo system 68, and the configurations of the servo systems 69, 70, and 71 are shown in the drawings. For the sake of simplicity, illustration thereof is omitted.

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. Based on this NC program, the CPU 67 sends a movement command pulse 72a and a servo motor 63 to the pulse shaping/direction discrimination circuit 73.
A command code 72b is sent to determine the direction of rotation.

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 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.

For example, based on the number of movement command pulses 72a, the second arm 28 moves from the state shown in FIG. 7 relative to the first arm 25 with reference to FIGS. 4, 7 and 8. It can be rotated 180° to change to the state shown in FIG.

Further, like the servo motor 63, the servo motor 92 can also rotate 360 degrees with respect to the base 90, for example, based on the number of movement command pulses 172a.

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, 92 and the main shaft motor 18a are CPU 67
They can be moved separately by commands. In addition, the operation panel 5 is connected to the CPU 67 via the cable 17 (see Fig. 2).
The sequence control section 83 is connected to, for example, a limit switch (not shown) of the main body 3.

Next, a case will be described in which, for example, a circular groove 97 and a linear groove 87 are machined on the upper surface W2 of the workpiece W, and a linear groove 86 is machined on the side surface W1, based on the NC program. (See FIGS. 5 to 8) First, as shown in FIG. 5, the workpiece W is set on the first table 7 via the stopper 85. Press the automatic operation button on the control panel 5 and move to the first table 7.
It is moved in the direction of arrow X by the servo motor 9. (See FIG. 1) 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. On the other hand, the second arm 28 of the universal head 1 has already been rotated 180 degrees from the state shown in FIG. 3 to the state shown in FIG. That is, the tool 61
is directed vertically downward and faces the upper surface W2 of the workpiece W.

Next, the servo motor 14 lowers the spindle head 11 in the direction of arrow Z, and the spindle motor 18a (first
(see figure) to turn the tool 61. The tool 61 cuts into the upper surface W2 to a predetermined depth. Then, the servo motor 92 is operated to connect the first arm 25 and the second arm 2.
8 is rotated 360° with respect to the spindle head 11.

By doing so, a circular groove 97 as shown in FIG. 6 can be formed. After machining, spindle head 11
rise.

The first table 7 and the second table 8 are moved (see FIGS. 1 and 2), the workpiece W is positioned at a new predetermined position as shown in FIG.
is lowered to cut into the upper surface W2 of the workpiece W with the tool 61. Then, the second table 8 is moved in the direction of the arrow in FIG. 2 (rightward) to form the groove 87 in the upper surface W2. Then, the spindle head 11 is raised.

Subsequently, the first table 7 and the second table 8 are moved again. In this way, the workpiece W is further positioned at a new predetermined position as shown in FIG. Second arm 28 of universal head 1
The tool 61 is rotated 180 degrees from the state shown in FIG. 7, and the tool 61 is directed horizontally to the left in the drawing, as shown in FIGS. 3 and 8. Then, the spindle head 1 is moved by the servo motor 14.
1 is lowered so that the tool 61 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 workpiece W. and,
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.

In this way, by simply setting the workpiece W on the first table 7 once and rotating the arm 28 of the universal head 1 by a predetermined angle, the workpiece can be machined on many sides.

The above is just one processing example. By operating the servo motors 92 and 63 simultaneously, three-dimensionally complex curve machining can be performed.

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 W. However, if a universal head with angles θ1 and θ2 set to other than 45° is prepared, the tool 61 can be applied to the upper surface of the workpiece at a desired angle.

Effects of the Invention As explained above, according to the present invention, curved or linear grooves can be formed on a workpiece by simply setting the workpiece on the table once. Additionally, the entire head can be configured simply and smartly.

[Brief explanation of drawings]

Fig. 1 is a front view showing a machine tool equipped with the universal head of the present invention, Fig. 2 is a side view of the same machine tool, Fig. 3 is a sectional view of the universal head, and Fig. 4 is a servo system and CNC device. Diagrams showing etc.
FIG. 5 is a diagram showing an example of machining a workpiece by the universal head, FIG. 6 is a perspective view of the machined workpiece, and FIGS. 7 and 8 are diagrams showing an example of machining the workpiece by the universal head. 1...Universal head, 2...Machine tool,
4...CNC device, 9, 10, 14, 63, 92
... Servo motor, 18 ... Main shaft, 25 ... First
Arm, 28... Second arm, 31... Transmission means, 61... Tool, 62... Second drive means, 90
... base, 91 ... first driving means.

Claims (1)

[Claims] 1. One end of a first arm is connected to the spindle head side, and the first arm is driven at a predetermined angle by a first driving means around the central axis of the spindle or one end of the first arm with respect to the spindle head. It is rotatable, and the central axis of the other end of the first arm intersects the central axis of the main shaft at an acute angle θ1, and one end of the second arm is connected to the other end of the first arm. It is rotatable by a predetermined angle with respect to the first arm around the central axis of the other end of the first arm or around the central axis of one end of the second arm, and the central axis of the other end of the second arm is rotatable by a predetermined angle. It intersects the central axis of the other end of the first arm at an acute angle θ2, and the second
A transmission means is supported along the center axis of each arm, one end of the transmission means is connected to the main shaft, and a tool is set at the other end of the transmission means on the other end side of the second arm. A universal head in a machine tool, which is configured so that the tool can be rotated by the rotation of the tool via a transmission means. 2 The central axis of the other end of the first arm intersects the central axis of the main shaft at an angle of 45°, and the central axis of the other end of the second arm intersects the central axis of the other end of the first arm at an angle of 45°. Universal heads in a machine tool according to claim 1 intersecting at an angle.