JP2003336713A - Rotary positioning mechanism - Google Patents

Abstract

(57) [Summary] [PROBLEMS] It is possible to simultaneously satisfy both high rigidity of positioning rigidity and high speed of positioning speed.
Provide a rotary positioning mechanism having excellent durability. A rotation positioning mechanism for determining a rotation position of a rotating body. The rotary driving device 6 includes two moving bodies 4 and 5 that move linearly on one straight line, and a link 7 provided between the rotating body 3 and one moving body 4. The rotating body 3 is pivotally mounted on the other moving body 5 of the rotary driving device 6 so as to be rotatable around an axis perpendicular to the moving direction of the moving bodies 4 and 5. Both ends of the link 7 are oscillated about an axis parallel to the rotation center line of the rotator 3 so that the rotator 3
Are pivotally attached to the portion deviated from the rotation center line and to one of the moving bodies 4, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary positioning mechanism used for NC machine tools, for example.

[0002]

2. Description of the Related Art Conventionally, a gear device has been used as a spindle head of a 5-axis control machining center or a rotary positioning mechanism for a rotating body in an NC machine tool such as a tilt table.

[0003]

However, in the gear device, in order to increase the positioning rigidity, it is necessary to increase the reduction ratio, and it is necessary to increase both the positioning rigidity and the positioning speed. There is a problem that they cannot be satisfied at the same time. Further, there is a problem that the gear teeth are easily worn and the durability is poor. Further, there is a problem that the positioning accuracy is not sufficient due to the influence of gear backlash.

An object of the present invention is to solve the above-mentioned problems and to provide a rotary positioning mechanism capable of satisfying both high positioning rigidity and high positioning speed at the same time and having excellent durability. To do.

[0005]

The rotary positioning mechanism according to the invention of claim 1 is a rotary positioning mechanism for determining the rotational position of a rotating body, and comprises two movements linearly moving on one straight line. A rotary drive device having a body and a link provided between the rotary body and one of the moving bodies, and the rotary body forms a right angle with the other moving body of the rotary drive device. A part that is rotatably pivoted about the axis of rotation and that is offset from the center of rotation of the rotating body so that both ends of the link can swing about an axis parallel to the center of rotation of the rotating body. Each of them is pivotally attached to the moving body.

According to the rotation positioning mechanism of the first aspect of the invention, the one moving body to which one end of the link is pivotally attached is
By moving the rotating body with respect to the other moving body that is pivotally attached, the rotating body can be rotated to determine its rotational position. Moreover, by moving the other moving body to which the rotating body is pivotally attached and moving both moving bodies so that the two moving bodies do not move relative to each other, the rotating body is linearly moved on the one straight line. It can be moved to determine the linear position. Here, if the spindle head is attached to the rotating body, it is possible to configure a machining center having both vertical and horizontal characteristics, and it is possible to configure a five-side processing machine in combination with a rotary table.

Since the rotary positioning mechanism according to the first aspect of the present invention is configured as described above, it is possible to satisfy both the high positioning speed of the rotating body and the high positioning rigidity. .

According to a second aspect of the present invention, in the rotary positioning mechanism according to the first aspect of the present invention, the rotary drive device includes two linear guide rails and two linear guide rails that are attached to the guide rails and move along the guide rails by rolling guides. A moving body, a ball screw shaft arranged parallel to the guide rail and non-rotating, and provided on each moving body so as to move therewith, and fitted through a plurality of circulating balls around the ball screw shaft. A ball nut and a servomotor provided on each moving body and rotating the ball nut.The rotating body is rotatably attached to the other moving body via a rolling bearing, and both ends of the link are It is pivotally attached to the rotating body and one moving body via rolling bearings.

The rotary positioning mechanism according to the second aspect of the present invention has only the rolling contact portion and does not have the sliding contact portion which is likely to be worn. Therefore, the durability is higher than that of the conventional gear device. improves. Moreover, since there is no sliding contact portion, rattling is prevented, and rigidity and positioning accuracy are improved as compared with the case where a conventional gear device is used.

A rotary positioning mechanism according to a third aspect of the present invention is a rotary positioning mechanism for determining the rotational position of a rotating body, and has one moving body that linearly moves in a direction perpendicular to a rotation center line of the rotating body. A rotary drive device and a link provided between the rotary body and the moving body are provided, and both ends of the link can swing about an axis parallel to the rotation center line of the rotary body. The rotating body is pivotally attached to a portion of the rotating body that is deviated from the rotation center line and the moving body.

According to the rotary positioning mechanism of the third aspect of the present invention, by moving the moving body, the rotating body can be rotated and the rotational position thereof can be determined. Here, if the spindle head is attached to the rotating body, it is possible to configure a machining center having both vertical and horizontal characteristics, and it is possible to configure a five-side processing machine in combination with a rotary table.

Since the rotary positioning mechanism according to the third aspect of the present invention is configured as described above, it is possible to satisfy both the high positioning speed of the rotating body and the high positioning rigidity. .

According to a fourth aspect of the present invention, in the rotary positioning mechanism according to the third aspect of the present invention, the rotating body driving device is attached to the linear guide rail and is moved along the guide rail by rolling guide. Body, a ball screw shaft arranged in parallel with the guide rail and rotatably supported by a fixed portion via a rolling bearing, and a plurality of circulating balls provided on the moving body and around the ball screw shaft. And a servo motor for rotating the ball screw shaft, and both ends of the link are pivotally attached to the rotating body and the moving body via rolling bearings.

Since the rotary positioning mechanism according to the invention of claim 4 has only the rolling contact portion and does not have the sliding contact portion where abrasion is likely to occur, it is more durable than the case where the conventional gear device is used. improves. Moreover, since there is no sliding contact portion, rattling is prevented, and rigidity and positioning accuracy are improved as compared with the case where a conventional gear device is used.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 This embodiment is shown in FIGS. 1 to 6, and the rotary positioning mechanism according to the present invention is applied to a rotating body to which a spindle head of an NC machine tool is attached. 1 to 3
Shows the overall configuration of the rotary positioning mechanism of the first embodiment, FIGS. 4 and 5 show the essential parts thereof, and FIG. 6 shows the electrical configuration of the rotary positioning mechanism. In the description of the first embodiment, the upper and lower sides and the left and right sides of FIG. 1 are referred to as the upper and lower sides and the left and right sides, respectively, and the left side of FIG.

1 to 3, a rotary positioning mechanism of an NC machine tool determines a rotary position of a rotary body (3) provided on the front surface of a column (1) and having a spindle head (2) attached thereto. And a rotary drive device (6) having two moving bodies (4) and (5) that move vertically on one straight line extending in the vertical direction.
And a link (7) provided between the rotating body (3) and the upper moving body (4).

The rotation drive device (6) is provided on the front surface of the column (1).
It is equipped with a pair of linear guide rails (8) that are attached at intervals in the left-right direction and extend in the up-down direction, and each moving body (4) (5) straddles both guide rails (8). It is attached and is adapted to move vertically along both guide rails (8). Also, rotary drive (6)
Is a vertically extending ball screw shaft (9) arranged in a vertically extending groove (1a) formed on the front surface of the column (1) between both guide rails (8), and each moving body (4 ) (5) and a ball nut (10) fitted through a plurality of circulating balls (not shown) provided with preload around the ball screw shaft (9), and each moving body (4) ( 5) Provided on the ball nut
A servo motor (11) for rotating (10) is provided. Both ends of the ball screw shaft (9) are fixed to a support (1b) fixedly provided on the bottom surface of the concave groove (1a) so as not to rotate.

As shown in FIG. 4, the rotating body (3) is a rolling element.
A rolling bearing (12) having a preload applied to (12a) is pivotally attached to a lower moving body (5) around an axis extending in the left-right direction. That is, the mounting portion (13) protruding forward is fixed to the upper end of the lower moving body (5), and the mounting portion (13) is formed with a through hole (13a) extending in the left-right direction. Further, at one end of the rotating body (3), a support portion (3a) is provided at intervals in the left-right direction, and a through hole (3b) extending in the left-right direction is formed in the support portion (3a). . Then, the mounting portion (13) of the moving body (5) is arranged between both supporting portions (3a) of the rotating body (3), and the mounting portion (13) and the through holes (13a) of both supporting portions (3a) ( 3
The shaft (14) passed through b) is attached to the mounting part via the rolling bearing (12).
It is rotatably supported by (13) and both supporting portions (3a).

Both ends of the link (7) are connected to the other end of the rotating body (3) and the lower end of the upper moving body (4) through a rolling bearing (12) in which a preload is applied to the rolling body. Each is rotatably pivoted about an axis extending in the left-right direction. That is, through holes (not shown) extending in the left-right direction are formed at both ends of the link (7). Further, at the other end of the rotating body (3) and at the lower end of the moving body (4), two supporting portions (3c) (4a) are provided at intervals in the left-right direction. Each of (3c) and (4a) has a through hole (not shown) extending in the left-right direction. Then, as in the case shown in FIG. 4, both ends of the link (7) are arranged between the support parts (3c) and (4a) of the rotating body (3) and the moving body (4), and the link (7)
And the shaft (14) passed through the through holes of both support parts (3c) (4a),
Link (7) and both supports (3c) through rolling bearing (12)
It is rotatably supported by (4a).

On the rear surface of each of the moving bodies (4) and (5), four runners (15) having a U-shaped cross section and which are guided by the guide rail (8) to move are fixed. As shown in FIG. 4, ball guide grooves (16) are formed on the inner side surfaces of the left and right rising portions (15a) of each runner (15). Also, check the runners on the left and right sides of the guide rail (8).
(15) Ball guide groove (16) and corresponding ball guide groove (1
7) has been formed. Ball guide groove (1
6) and the corresponding ball guide groove on the guide rail (8)
A ball outward path (18) is formed by (17). Also,
Hole-like ball return path (19) on the outer side in the left-right direction from the ball guide groove (16) at the rising portion (15a) of each runner (15).
Are formed. The end of the ball outward path (18) and the end of the ball return path are connected by ball reversal paths (not shown) formed at the upper and lower ends of each runner (15) to form an endless ball circulation path (20 ) Is formed and the ball circuit (20)
A plurality of circulating balls (21) are enclosed in. Ball outbound
At (18), the ball (21) is preloaded.

As shown in FIG. 5, the servomotor (11) includes a motor housing (22) fixed to the moving bodies (4) and (5), a rotor (23), and a stator (24). . A hollow rotary shaft (25) is arranged in the motor housing (22) such that both upper and lower ends of the hollow rotary shaft (25) project outside the motor housing (22). ). The upper and lower ends of the rotary shaft (25) are rotatably supported by the angular contact ball bearings (26) and (27) with respect to the motor housing (22). Both angular ball bearings (26) and (27) respectively support a radial load and a unidirectional thrust load, and are formed as a front combination. Axis of rotation
A rotor (23) is provided on the outer circumference of the (25), and a stator (24) is provided on the inner circumference of the motor housing (22) around the rotor (23). Preload is applied to the balls (26a) and (27a) of the angular contact ball bearings (26) and (27), respectively. At the lower end of the rotary shaft (25),
The ball nut (10) is connected through the coupling (28). When the rotary shaft (25) is rotated by the servo motor (11), the ball nut (10) rotates and the ball screw shaft
It moves in the longitudinal direction of (9), which causes the coupling (2
8), the moving bodies (4) and (5) are moved in the vertical direction via the rotary shaft (25) and the motor housing (22).

According to the rotary positioning mechanism having the above construction, it is possible to construct a machining center having both vertical and horizontal characteristics, and it is possible to construct a five-face machining machine in combination with a rotary table. Become.

As shown in FIG. 6, the rotary positioning mechanism of the NC machine tool has a computer numerical control unit (CNC unit) (3
0) and controls the servo motors (11) and controls the servo motors (11A) and (31A) (31B) and the output power of each control device (31A) (31B) is amplified to the servo motor (11). Two power amplifiers (32A) (32B) for output and two position detectors (33A) connected to each control device (31A) (31B) and detecting the position and speed of each moving body (4) (5) ) (33B). Each controller (31
A) (31B) is a position control unit (34A) (34B) that controls the position of each moving body (4) (5), and a speed control unit (35A) (35B) that controls the speed.
Includes and.

In the rotary positioning mechanism of the NC machine tool configured as described above, the CNC unit (30) generates a function for the input target value (angle and position of the rotating body (3)), and each movement is performed by coordinate conversion. The amount of movement is distributed to each of the bodies (4) and (5), and the control devices (31A) and (31B) supply the power corresponding to this to each power amplifier (3
Output to each servo motor (11) via 2A) and (32B). Then, the ball nut (10) is rotated and both moving bodies (4) (5)
Moves linearly, and the rotating body (3) also moves linearly. Here, when the moving speed and the moving direction of both moving bodies (4) and (5) are the same, the rotating body (3) does not rotate and only moves linearly. On the other hand, when the moving speed or moving direction of both moving bodies (4) (5) is different, due to the action of the link (7),
The rotating body (3) is rotated by a predetermined angle in addition to being linearly moved. At this time, the position and speed of both moving bodies (4) (5) are detected by the position detectors (33A) (33B), and the position control units (34A) (34B) and the respective control devices (31A) (31B) and It is fed back to the speed control units (35A) and (35B). Then, each control device (31A) (31B)
In order to obtain the required position and speed of both moving bodies (4) (5) based on this position data and speed data, each servo motor (11) is connected via each power amplifier (32A) (32B). Adjust the power output to. The position detectors (33A) and (33B) are the rotation center (for detecting the rotation angle position) of the rotating body (3) and the rotating body (3).
May be attached to the moving body (5) (for linear position detection) to which is pivotally attached.

Embodiment 2 This embodiment is shown in FIGS. 7 to 9, and the rotary positioning mechanism according to the present invention is applied to a rotating body to which a spindle head of an NC machine tool is attached. 7 and 8 show the entire configuration of the rotary positioning mechanism of the second embodiment, and FIG. 9 shows the essential parts thereof. In the description of the second embodiment, the upper and lower sides and the left and right sides of FIG. 7 are referred to as the upper and lower sides and the left and right sides, respectively, and the left side of FIG. 9 is referred to as the front side and the right side is referred to as the rear side.

7 and 8, the rotary positioning mechanism of the NC machine tool determines the rotational position of the rotary body (42) provided on the rotary body fixture (40) and having the spindle head (41) attached thereto. It is a moving body that moves linearly in the left and right direction (43)
A rotary drive device (44) having a rotary body (42) and a moving body (43)
And a link (45) provided between and.

The rotating body attachment (40) includes a horizontal wall portion (40a) and
It is composed of a pair of hanging wall parts (40b) provided on both front and rear edges of the horizontal wall part (40a), and the rotating body (42) is provided with rolling bearings (46) in which the rolling elements are preloaded. Rotator attachment
The hanging wall (40b) of the (40) is pivotally attached to the lower end of the hanging wall (40b) about an axis extending in the front-rear direction. That is, the shaft (47) extending in the front-rear direction is fixed between both hanging wall parts (40b) of the rotating body attachment (40), and one end of the rotating body (42) is attached to the shaft.
It is mounted around (47) via rolling bearings (46).

The rotation drive device (44) is a linear guide rail (48) having a substantially U-shaped cross section and extending in the left-right direction, which is attached to the lower surface of the horizontal wall portion (40a) of the rotating body attachment (40). The moving body (43) is arranged in the guide rail (48) and moves in the left-right direction along the guide rail (48). Further, the rotation drive device (44) is provided with a guide rail (48).
It is rotatable via rolling bearings (50) in which the rolling elements are preloaded to a support (49) that is placed inside and parallel to this and has both ends inside the guide rail (48). And a ball screw shaft (51) supported by the movable body (43) and a plurality of circulating balls (not shown) preloaded around the ball screw shaft (51). Servo motor which is attached to the ball nut part (52) (see FIG. 9) and the one support (49) and rotates the ball screw shaft (51).
(53) and are provided. When the ball screw shaft (51) is rotated by the servo motor (53), the ball nut portion
(52) moves in the left-right direction, and the moving body (43) integrated with this also moves in the left-right direction.

As shown in FIG. 9, upper and lower rows of ball guide grooves (54) are formed on the inner side surfaces of the hanging parts (48a) on the front and rear sides of the guide rail (48). Ball guide grooves (55) in two rows, which correspond to the ball guide grooves (54) of the guide rail (48), are formed on both front and rear surfaces of the moving body (43). A ball forward path (56) is formed by the ball guide groove (54) of the guide rail (48) and the ball guide groove (55) of the moving body (43) corresponding thereto. Two upper and lower rows of hole-like ball return paths (57) are formed inward of the upper and lower ball guide grooves (55) of the moving body (43) in the front-rear direction. And
An upper end and a lower end of each ball forward path (56) and each ball return path (57) are formed at both ends in the moving direction of the moving body (43).
An endless ball circulation path (58) is formed by being connected by two inversion paths (not shown), and a plurality of balls (59) are enclosed in the ball circulation path (58). Preload is applied to the ball (59) in the ball outward path (56). A mounting portion (60) having a substantially inverted U-shaped cross section is fixed to the lower surface of the moving body (43).

Both ends of the link (45) are connected to the other end of the rotating body (42) and the mounting portion (60) of the moving body (43) through the rolling bearing (61) in which the rolling element is preloaded. , Each of which is rotatably pivoted about an axis extending in the front-rear direction. That is, as shown in FIG. 9, through holes (45a) extending in the front-rear direction are formed at both ends of the link (45). Further, two supporting portions (42a) are provided at the other end of the rotating body (42) at intervals in the front-rear direction. These supporting portions (42a)
Through holes (not shown) that extend in the front-rear direction are formed in each. Further, through holes (60b) extending in the front-rear direction are formed in both hanging parts (60a) of the attachment part (60). And
Both ends of the link (45) are arranged between both supporting parts (42a) of the rotating body (42) and between both hanging parts (60a) of the mounting part (60).
(45) and the through holes (6a) of both support parts (42a) and both hanging parts (60a).
The shaft (62) passed through 0b) is rotatably supported by the link (45), both supporting parts (42a) and both hanging parts (60a) via the rolling bearing (61).

According to the rotary positioning mechanism having the above construction, it is possible to construct a machining center having both vertical and horizontal characteristics, and it is possible to construct a five-face machining machine in combination with a rotary table. Become.

The electrical construction of the rotary positioning mechanism of the second embodiment is different from that of the first embodiment except that it has one servo motor (53), and therefore has one controller, one power amplifier, and one position detector. This is similar to the case of the first embodiment.

In the rotary positioning mechanism of the NC machine tool having the above-mentioned configuration, the CNC section performs a function generation with respect to the input target value (angle of the rotating body (42)), and the moving body (43) is moved by coordinate conversion. The amount is calculated, and the control device outputs the corresponding power to the servo motor (53) via the power amplifier. Then, the ball screw shaft (51) is rotated to move the moving body.
The (43) moves linearly, and the action of the link (45) causes the rotating body (42) to rotate by a predetermined angle. At this time, the moving body (4
The position and speed in 3) are detected by the position detector and fed back to the position controller and speed controller of the control device. Then, the control device adjusts the electric power output to the servo motor through the power amplifier so that the required position and speed of the moving body (43) can be obtained based on the position data and the speed data.

Embodiment 3 This embodiment is shown in FIG. 10, and the rotary positioning mechanism according to the present invention is applied to a tilt table of an NC machine tool. In the description of the third embodiment, the upper and lower sides and the left and right sides in FIG. 10 are referred to as the upper and lower sides and the left and right sides, respectively. In FIG. 10, the rotational positioning mechanism of the NC machine tool determines the rotational position of the tilting table (71) provided on the upper surface of the base (70), and the left and right moving horizontally on one straight line It is provided with a rotary drive device (6) having two moving bodies (5) and (4), and a link (7) provided between the tilt table (71) and one moving body (4). The rotary positioning mechanism is the same as that of the first embodiment except that the base (70) is used instead of the column (1) and the tilt table (71) is used instead of the rotating body (3). Therefore, the same parts are denoted by the same reference numerals, and duplicate description will be omitted. In FIG. 10, the right moving body (4) corresponds to the upper moving body (4) of the first embodiment, and the left moving body (5) also corresponds to the lower moving body (5). Further, the supporting portions (3a) and (3c) of the rotating body (3) in the first embodiment correspond to the supporting portions (71a) and (71b) of the tilt table (71).

[Brief description of drawings]

FIG. 1 is a front view showing a rotary positioning mechanism according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway side view of the same.

FIG. 3 is a side view showing a rotary positioning mechanism in which the position of the moving body is different from that in FIG.

FIG. 4 is an enlarged sectional view taken along line IV-IV of FIG.

5 is a sectional view taken along line VV of FIG.

FIG. 6 is a block diagram showing an electrical configuration of the rotary positioning mechanism of the first embodiment.

FIG. 7 is a partially cutaway front view showing a rotary positioning mechanism according to a second embodiment.

8 is a partially cutaway front view showing a rotary positioning mechanism in which the position of the moving body is different from that in FIG. 7. FIG.

9 is an enlarged sectional view taken along line IX-IX in FIG.

FIG. 10 is a front view showing a rotary positioning mechanism according to a third embodiment.

[Explanation of symbols]

(3) (42): Rotating body (4) (5) (43): Mobile (6) (44): Rotary drive (7) (45): Link (8) (48): Guide rail (9) (51): Ball screw shaft (10) (52): Ball nut (11) (53): Servo motor (12) (61): Rolling bearing (71): Tilt table

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Claims (4)

[Claims] 1. A rotary positioning mechanism for determining the rotational position of a rotating body, comprising: a rotary drive device having two moving bodies that linearly move on one straight line; and between the rotating body and one of the moving bodies. The rotating body is rotatably attached to the other moving body of the rotary drive device so as to be rotatable about an axis that is perpendicular to the moving direction of the moving body, and both ends of the link rotate. A rotary positioning mechanism that is pivotally attached to a portion of the rotating body that is offset from the rotation center line and one of the moving bodies so as to swing about an axis parallel to the rotation center line of the body. 2. A rotary drive device is arranged parallel to a linear guide rail, two moving bodies attached to the guide rail and moving along the guide rail by rolling guides, and parallel to the guide rail and non-rotating. A ball screw shaft, a ball nut mounted on each moving body so as to move therewith, and fitted through a plurality of circulating balls around the ball screw shaft, and a ball nut mounted on each moving body and rotating the ball nut. The rotating body is rotatably pivoted to the other moving body via the rolling bearings, and both ends of the link are pivotally attached to the rotating body and one of the moving bodies via the rolling bearings. The rotary positioning mechanism according to claim 1, which is provided. 3. A rotary positioning mechanism for determining the rotational position of a rotating body, comprising: a rotary drive device having one moving body that linearly moves in a direction perpendicular to a rotation center line of the rotating body;
The rotating center of the rotating body is provided so that both ends of the link can swing around an axis parallel to the center of rotation of the rotating body. A rotary positioning mechanism that is pivotally attached to the part displaced from the line and the moving body. 4. A rotary body driving device includes a linear guide rail, a moving body attached to the guide rail and moving along the guide rail by rolling guide, and a moving body arranged parallel to the guide rail and via a rolling bearing. A ball screw shaft rotatably supported by the fixed portion, a ball nut provided on the moving body and fitted around the ball screw shaft via a plurality of circulating balls, and a servomotor for rotating the ball screw shaft. 4. The rotary positioning mechanism according to claim 3, further comprising: both ends of the link being pivotally attached to the rotating body and the moving body via rolling bearings.