JPH10315077A - Horizontal type machining center - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain the favorable movability and stable processing accuracy of a main spindle. SOLUTION: An X axis slide table is provided horizontally and movably on the front surface of a fixed column 3 erected on a main body bed 2 and a Y axis slide table 16 is provided vertically and movably on the front surface of the X axis slide table. In this Y axis slide table 16, a spindle head 22 with a hexagonal section is formed integrally in a Z axis direction and the spindle 23 with the same hexagonal section is loosely inserted movably in the Z axis direction independently. Further, a tool replacement device 5 is provided on the fixed column 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal machining center that performs machining by performing NC control of a horizontally disposed spindle in three directions of X, Y, and Z axes.

[0002]

2. Description of the Related Art Usually, a horizontal machining center is provided with a movable column on a main body bed which can move linearly in the left-right direction (X-axis direction) and back and forth (Z-axis direction), and the main shaft is rotatably provided on the movable column. A moving column type in which a spindle head is provided so as to be able to linearly move up and down (Y-axis direction) is well known. In addition, a tool changing device including a tool magazine and a tool changing arm is integrally provided above the moving column. However, in this case, the vertical dimension of the moving column is increased by the amount of the tool changing device, and the center of gravity of the moving column is increased. In addition, there is a problem that the stability and mobility of the movable column are reduced due to an increase in the weight of the tool changing device and the position of the tool changing arm. Therefore, real fairness 7-302
Japanese Patent No. 60 gazette discloses that a magazine supporting base is provided on a main body bed separately from a moving column, and a tool exchanging device is provided on the magazine supporting base, so that only the moving column is moved alone. There is disclosed a device for lowering the height of a vehicle and improving stability and mobility.

[0003]

However, even in the above-mentioned invention, since the movement of the X and Z axes is obtained by the movement of the movable column itself, there is a limit to the improvement of the mobility due to the weight of the movable column, and the speed is high. At the time of control, the influence of the inertial force also occurs.
Also, since the moving part is large, the distance from the main shaft to the sliding surface of the moving column is long, mechanically unstable and rigidity is reduced, which is susceptible to errors due to thermal deformation etc. Connect. Furthermore, since it is necessary to increase the area of the main body bed in order to secure the moving space for the moving column, when forming a transfer line adjacent to a similar machining center or the like, there is a problem that a loss occurs in the delivery time of the processed work. is there. In addition, during processing, chips accumulate on the bed between the processing unit and the moving column.However, the moving structure of the moving column makes it difficult to discharge chips, which also causes a reduction in the mobility of the moving column. ing. On the other hand, the separation between the moving column and the tool changing device increases the distance between the center of the spindle and the tool changing position. Therefore, it is necessary to lengthen the tool change arm, and the swing at the time of change becomes large, so that the tool change time cannot be reduced.

Accordingly, the present invention makes the moving part of the main shaft compact, maintains good mobility and stable machining accuracy, makes the whole machine compact, and further facilitates the discharge of chips. It is an object of the present invention to provide a horizontal machining center in which the influence of the accumulation is eliminated.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, a column is fixed.
An X-axis slide table movable in the horizontal direction is provided on the front surface of the fixed column, and a Y-axis slide table movable in the vertical direction is provided on the front surface of the X-axis slide table. It is characterized by being provided integrally with the slide table and capable of independently moving in the Z-axis direction. Further, in addition to the object of the first aspect, the invention according to the second aspect is characterized in that the Y-axis slide table is provided with a Y-axis slide table in order to more effectively obtain the rigidity and stability of the main shaft that independently moves in the Z-axis direction. A cylindrical body having a polygonal cross section that penetrates the axis slide table in the Z-axis direction is integrally provided, and the main shaft is made to have a polygonal cross section that matches the cylindrical body so that the cylindrical body can be freely moved in the Z-axis direction. It is inserted. Claim 3
In addition to the object of claim 1 or 2, in addition to the object of claim 1 or 2, the tool change device in order to shorten the tool change time and reduce the height of the entire device, A tool change arm provided between the tool magazine provided on the main shaft and the main shaft; and a control axis for controlling rotation and movement of the tool change arm in the Z-axis direction. Is decentered by a predetermined amount from the axis of the control shaft toward the main shaft.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall view of a horizontal machining center 1 according to the present invention. A fixed column 3 is provided upright on a main body bed 2, and a front side of the fixed column 3 (FIG.
On the left front side), a three-axis unit 4 having a spindle 23 is formed, and a tool changing device 5 is installed above the fixed column 3. In front of the fixed column 3, there is provided a processing unit 8 which is rotatable in the A-axis and B-axis directions and has a processing table 7 on which a processing work 6 is placed. First, the three-axis unit 4 of the fixed column 3 will be described. As shown in FIG. 2, a pair of upper and lower parallel X-axis linear guides 9, 9 are projected from the front surface of the fixed column 3 from which the cover 3a is removed. An X-axis slide table 10 is provided which can move in the horizontal direction (X-axis direction) while holding the 9 and 9). The X-axis slide table (hereinafter referred to as X
An X-axis ball screw 11 rotatably mounted on the front surface of the fixed column 3 in parallel with the X-axis guides 9 and 9 is screwed to the X-axis ball screw 10 at a screwing portion 10a. Bevel gear 12 integrally fixed to the end of 11
By meshing with the drive gear 14 at the tip of the motor shaft of the X-axis servo motor 13 housed in the fixed column 3, X
The drive gear 1 is driven by the drive of the shaft servomotor 13.
4. The X-axis ball screw 11 rotates via the bevel gear 12,
The X-axis table 10 can be screw-fed in the X-axis direction.

On the front surface of the X-axis table 10, a pair of right and left vertical Y-axis linear guides (hereinafter referred to as Y-axis guides) 1 is provided.
5 and 15 are projected, and the Y-axis guides 15 and 1 are provided.
A Y-axis slide table (hereinafter, referred to as a Y-axis table) 16 is provided, which is capable of gripping and moving in the vertical direction (Y-axis direction). Further, on the front surface of the X-axis table 10, a Y-axis ball screw 17 parallel to the Y-axis guides 15, 15 is installed in a rotationally fixed state. On the other hand, a Y-axis servomotor 18 is integrally fixed to the lower end of the Y-axis table 16, and a drive gear 19 provided on the motor shaft of the Y-axis servomotor 18 in a lower portion of a hexagonal spindle head 22 described later. However, through the idle gear 20, the nut gear 2
1 is engaged. The nut gear 21 is rotatably supported by a ball bearing (not shown) on the back surface of the Y-axis table 16 and is screwed to the Y-axis ball screw 17. Therefore, the drive of the Y-axis servo motor 18 causes the drive gear 19 and the idle gear 20 to drive the nut gear 2
1 rotates and moves along the Y-axis ball screw 17 so that the Y-axis table 16 and the Y-axis
It will move in the axial direction.

[0008] Then, as shown in FIG.
At the center of 6, a cylindrical spindle head 22 whose inner surface is a regular hexagonal cross section and a pair of parallel two surfaces are horizontal is formed integrally in a shape penetrating in the front-rear direction (Z-axis direction),
The spindle head 22 accommodates a spindle 23 having a regular hexagonal cross section and a main shaft that can move back and forth in the Z-axis direction. This spindle 23
Is a built-in type in which a motor and a rotating shaft (not shown) are coaxially built in a quill having a regular hexagonal cross section.
Is protruding. A bracket 25 projects from the lower surface of the spindle 23, and one end of a Z-axis ball screw 26 parallel to the axis of the spindle 23 is attached to the bracket 25 in a rotationally fixed state. Similarly, a Z-axis servomotor 27 parallel to the axis of the spindle 23 is fixed to the lower surface of the spindle head 22, and a nut gear 29 meshing with a drive gear 28 of the motor shaft is not shown on the lower surface of the spindle head 22. It is rotatably supported by a ball bearing, and is screwed with a Z-axis ball screw 26. Therefore, by driving the Z-axis servo motor 27,
When the nut gear 29 rotates via the drive gear 28, the Z-axis ball screw 26 screwed to the nut gear 29
The screw is fed in the axial direction, and the spindle 23 slides in the spindle head 22 through the bracket 25 in the Z-axis direction. X-axis table 10 and fixed column 3
Are formed at the front surface thereof with openings 10b and 3b allowing at least the movement of the spindle head 22 and the spindle 23 in the Y-axis direction and the X-axis direction, respectively.

On the other hand, the tool changing device 5 on the fixed column 3
An ATC unit 30 located directly above the fixed column 3,
The ATC unit 30 has an offset gear box 31
And a tool magazine 33 provided on the ATC unit 30.
First, as shown in FIG. 4, the ATC unit 30 includes a drive motor 34, and is installed in parallel with the axis of the spindle 23 by well-known drive control, and an ATC spindle 35 as a control shaft penetrating the offset gear box 31.
Is rotated and moved back and forth in the axial direction. This A
The TC spindle 35 is axially supported by ball bearings 36 and 36 in the offset gear box 31 and has a spindle gear 37 fixed thereto. The movement in the axial direction is integral with the offset gear box 31.

A in the offset gear box 31
On the opposite side of the TC unit 30, the ATC spindle 3
An offset spindle 38, which is parallel to 5 and arranged obliquely below, has an axial movement freely inserted integrally, and an offset gear 40 is fixed to one end supported by ball bearings 39, 39. And is engaged with the spindle gear 37. At the other end of the offset spindle 38, the center of a tool change arm 32 having tool grips 41, 41 formed at both ends is fixedly attached.
The tool change described later is made possible by the rotation and axial movement of 5. In particular, here, the tool change arm 3
The offset spindle 38 serving as the center of rotation of the
By eccentrically approaching the spindle 23 side with an eccentric amount X just below the C spindle 35, the radius of the tool change arm 32 is minimized, and the moving distance of the two gripping portions 41 accompanying the turning of the tool change arm 32 is minimized. ing. That is, as shown in FIG. 5, by moving the center of rotation of the tool change arm 32 closer to the delivery position on the spindle 23 side by the amount of eccentricity X, the radius P of the conventional tool change arm 32a is changed from the radius L of the conventional tool change arm 32a.
= (LX), and the tool magazine 33 can be made closer to the ATC unit 30 side by 2X, which is twice the amount of eccentricity, to reduce the overall height. . In FIGS. 1 and 4, reference numeral 42 denotes an ATC spindle which is provided in the ATC unit 30 in parallel with the ATC spindle 35 and is loosely inserted into the offset gear box 31;
Gearbox 31 associated with the axial movement of 5
A guide bar for guiding the front and rear movement of
3 is each tool holder 33a of the tool magazine 33, 33a
・ ・ Servo motor for feed control.

The horizontal machining center 1 having the above-described structure controls the X-axis table 10 horizontally by the NC control of the three-axis servo motors, that is, in the X-axis direction, by the drive control of the X-axis servo motor 13 as described above. Slide in the direction
In the axial direction, the Y-axis table 16 is slid vertically by the drive control of the Y-axis servo motor 18, and in the Z-axis direction, the spindle 2 is driven by the drive control of the Z-axis servo motor 27.
By sliding only 3 in the axial direction in the spindle head 22, the movement of the spindle 23 to a predetermined machining position or the delivery position of the tool can be controlled. These are only the spindle 23 or each slide table 10,
Since the movement is performed with a minimum configuration such as 16 or the like, the responsiveness of the lightened spindle 23 is improved, good mobility is obtained, and the influence of inertia is less likely to occur even during high-speed control. In particular, since only the spindle 23 can be independently moved in the Z-axis direction, the
Since the distance from the machining position to the sliding surface with the spindle head 22 becomes very short, and the spindle is located at the center of the sliding surface, the influence of thermal deformation and the like is minimized,
Good processing accuracy can be maintained. In addition, since the column remains fixed, the stability of the fixed mold can be maintained as it is, and since the distance between the processing work and the triaxial unit does not always change, the discharge of chips becomes easy,
Has no effect on processing. Further, here, since the spindle 23 and the spindle head 22 have a hexagonal cross section, the rigidity of the spindle 23 is secured even when the spindle 23 is independently moved in the Z-axis direction, and the durability against the reaction force during cutting is improved. . Of course, there is no problem with high-speed rotation.

In the tool changer 5, normal tool change control is performed. First, a desired tool is set at the delivery position by rotation of the tool magazine 33 by the servo motor 43, and the spindle 2 is controlled by the three-axis unit 4.
3 is set to the delivery position, the drive motor 34 is driven to rotate the ATC spindle 35, and the tool change arm 32 is rotated. Then, as shown in FIG. 5A, the grippers 41, 41 grip the tool at the delivery position, respectively, up and down. Next, when the ATC spindle 35 is moved forward in the axial direction, the offset spindle 38 and the tool change arm 32 advance together with the offset gear box 31, and the tool at the delivery position is removed from the tool holders 33a and 24, respectively.
Then, when the ATC spindle 35 is rotated to rotate the tool change arm 32 by 180 ° from the position, the positions of the upper and lower tools are switched. Therefore, if the ATC spindle 35 is retracted in the axial direction and the tool change arm 32 is retracted together, the replaced tools will be in the tool magazine 3 respectively.
3 and the spindle 23 are mounted on the tool holders 33a and 24, and the tool exchange is completed.

In the tool change control, since the offset spindle 38 which is the center of rotation of the tool change arm 32 is eccentric from the ATC spindle 35 toward the spindle 23 as described above, the center of rotation of the tool change arm 32 is 23 and at the same time, Tool Magazine 3
3 can be brought closer to the fixed column 3 side. Therefore, the radius of the tool changing arm 32, that is, the moving distance of the grip portion 41 is shortened, so that the tool can be changed in the shortest time, and the overall height of the horizontal machining center 1 can be reduced. In addition, since it is a fixed column type, when a movable column is used, there is no need to separately provide a support base or the like for mounting a tool changer around the outer periphery of the movable column.
Can be small. Particularly, when a transfer line or the like in which a plurality of horizontal machining centers 1 and the like are arranged in parallel as in the present invention, the machining centers of adjacent stations are brought close to each other as much as possible, thereby shortening the delivery time of the processed work. Is advantageous. Further, since the stability of the fixed column 3 can be maintained, even when the transfer line is formed, even if a tool change or the like is performed during machining at an adjacent machining center, the influence of vibration or the like does not occur.

The spindle head 22 and the spindle 23
As the polygonal shape described above, a regular hexagonal cross section in which a pair of two surfaces are horizontal as in the above embodiment is preferable because stability and movement error during movement and high rigidity can be obtained, but other regular pentagons and regular octagons are preferable. Other polygonal shapes such as a square shape may be used. Also, the moving structure of each slide table in the three-axis unit is not limited to the above-described embodiment.
These may not be a pair but may be only one. Furthermore, offset spindle 3 in tool changer
The design of the eccentric structure 8 can be changed as appropriate, for example, the eccentric structure is not obliquely downward but directly below, as in the above embodiment.

[0015]

According to the first aspect of the present invention, the main axis is set together with the slide table for the X and Y axes or independently.
Since it can be moved in the axial direction, good mobility and stable processing accuracy not affected by thermal deformation or the like can be obtained. In addition, because it is a fixed column, it can easily discharge chips and eliminate the effects of its accumulation, and in addition to preventing the entire machine from becoming larger than a moving column, deliver processed workpieces when applied to a processing line. It is also possible to improve work efficiency such as shortening time. According to the second aspect of the present invention, in addition to the effect of the first aspect, the main shaft and the cylindrical body have the polygonal cross section, so that the rigidity of the main shaft that moves independently in the Z-axis direction is improved. Stability can be obtained more effectively. According to the invention described in claim 3, in addition to the effect of claim 1 or 2, the rotation center of the tool change arm is
By eccentricity from the control shaft to the main shaft side, the radius of the tool changing arm and the moving distance of the tool due to its rotation are shortened, the tool changing time can be shortened, and the height of the entire apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is an overall explanatory view of a horizontal machining center.

FIG. 2 is an explanatory diagram of a structure of a three-axis unit in X and Y-axis directions.

FIG. 3 is an explanatory diagram of a structure of a three-axis unit in a Z-axis direction.

FIG. 4 is an explanatory diagram of a tool changing device in which a tool magazine is omitted.

FIG. 5A is an explanatory view of a tool change arm of the present invention. (B) It is explanatory drawing of the conventional tool change arm.

[Explanation of symbols]

1. Horizontal machining center 2. Body bed 3.
· Fixed column, 4 · · · 3 axis unit, 5 · · · Tool changer, 10 · · · X axis slide table, 11 · · · X axis ball screw, 13 · · · X axis servo motor, 16 · · · Y axis slide table, 17 ··· Y axis ball screw, 18 ·· Y axis servo motor, 22 ·· spindle head, 23 ·· spindle, 26 ··· Z axis ball screw, 27 ··· Z axis servo motor, 30 ·· ATC unit, 31 ·· Offset Gearbox, 32 tool exchange arm, 33 tool magazine, 35 ATC spindle, 38 offset spindle.

Claims (3)

[Claims] 1. A horizontal machining center in which a fixed column is erected on a main body bed, a spindle is provided on a front surface of the fixed column, and a tool changing device is provided above the fixed column. , An X-axis slide table movable in the horizontal direction is provided, and a Y-axis slide table movable in the vertical direction is provided on the front surface of the X-axis slide table, so that the main shaft is integrated with the Y-axis slide table. A horizontal machining center provided independently movable in the Z-axis direction. 2. A cylindrical polygonal body having a polygonal cross section penetrating the Y-axis slide table in the Z-axis direction is provided integrally with the Y-axis slide table, and the main shaft is formed into a polygonal cross-section that matches the cylindrical body. 2. The horizontal machining center according to claim 1, wherein the horizontal machining center is loosely inserted into the cylindrical body so as to be movable in the Z-axis direction. 3. A tool changing arm comprising: a tool changing arm provided between a tool magazine provided on an upper side and the main spindle; and a control axis for controlling rotation and movement of the tool changing arm in the Z-axis direction. The horizontal machining center according to claim 1 or 2, wherein a rotation center of the tool change arm is decentered from the axis of the control shaft toward the spindle by a predetermined amount.