JPH03178725A - Floating holder - Google Patents

Abstract

PURPOSE:To facilitate positioning of a cutting tool and also shorten the time required for processing works by supporting a shaft holding portion to a first holder in such a manner as being moveable perpendicular to the axial direction of the main spindle of the cutting tool, and also supporting a tilting shaft by means of a spherical bearing to a second holder fixed to the shaft holding portion. CONSTITUTION:When the center line of a lower hole H provided through a work W is not identical with that of the main spindle 1 of a machining tool, a shaft holding portion 3 is supported by a thrust bearing 36 together with a tilting shaft 7 and a second holder 5 via a socket 9 and bends a compression spring 33 and is horizontally moved by the distance between the respective center lines of the lower hole H and the main spindle 1. when the main spindle 1 is rotated a ball 4 transmits torque to the shaft holding portion 3 while rolling, because though the centers of rolling channels 23 and 33 are not identical with each other the ball 4 is fitted in both channels 23, 33. The shaft holding portion 3 is rotated while being eccentric with respect to the main spindle 1. When a cutting tool 8 is pulled after processing the work W, the shaft holding portion 3 is horizontally moved by the compression spring 33 by the distance between the respective centers of the rolling channels 23 and 33 and returns to its original point.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a floating holder for holding a tap, a torque wrench socket, etc. on the main shaft of a processing tool.

[Conventional technology] Conventionally, when a processing tool such as a tapping unit was attached to the wrist of an industrial robot and a cutting tool such as a tap was used to process screws, etc., the processing tool was not only held vertically, but also horizontally or inclined. There are many things to do. However, it is difficult to match the position and orientation of the cutting tool to the machining accuracy by controlling the posture of an industrial robot, so the cutting tool is held by a floating holder to prevent excessive force from being applied to the cutting tool even if there is a slight positioning error. ing.

Its structure is such that in order to align the center line of the machined hole and the cutting tool, the cutting tool holder is floated in the axial direction with respect to the main axis of the processing tool via a spring, and in the direction of rotation it is suspended from the main axis of the processing tool. A device configured to transmit torque to a cutting tool holder has been disclosed (for example, Japanese Patent Application Laid-Open No. 61-30
No. 351, Japanese Utility Model Application Publication No. 62-68725).

[Problems to be Solved by the Invention] However, in the above configuration, the means for floating the cutter holder with respect to the spindle relies on a spring that presses the cutter holder in the axial direction. When it is desired to make a parallel movement in a direction perpendicular to the direction, the cutting tool holder tends to tilt at the same time, and if the cutting tool is fed in the axial direction, there is a risk that the cutting tool will remain tilted relative to the workpiece or the prepared hole during machining.

In addition, the spring that presses the tool holder in the axial direction has a weak force to push the tool holder in the direction perpendicular to the axial direction of the spindle after it has tilted or moved in parallel, and it does not return accurately to the origin after machining. When a processing tool is positioned by a controlled robot or the like, the positioning accuracy of the next processing step may deteriorate.

Furthermore, in the above configuration, the allowable deviation length between the center line of the machined hole and the cutting tool is small, for example, the eccentricity between the machined hole and the cutting tool is ±0.3 m.
Since it is necessary to position the device at an angle of about 10 m and the center line, there is a drawback that positioning takes time.

The present invention provides a spring that presses the cutter holder in a direction perpendicular to the axial direction of the spindle to increase the allowable deviation length and ensure return to origin, thereby ensuring accuracy in positioning the cutter holder. The purpose is to provide a high floating holder.

[Means for Solving the Problems] The present invention provides a floating holder for holding a cutting tool on the main shaft of a processing tool, including a cup-shaped first holder 2 fixed to the tip of the main shaft, and a first holder 2 from the first holder 2. A compression spring 34 is provided which presses the shaft holding part 3 in a direction perpendicular to the axial direction of the main shaft l, and a compression spring 34 is provided that is capable of transmitting torque. The first holder 2 is provided with a thrust bearing 36 that supports the shaft holder 3 so as to be able to move in parallel in a perpendicular direction;
A cup-shaped second holder 5 is fixed to the shaft holding part 3,
A tilting shaft 7 capable of transmitting torque from the second holder 5, a spherical bearing 6 supporting the tilting shaft 7 so as to be tiltable with respect to the axial direction of the main shaft l, and the shaft holding portion 3. A thrust spring 74 is provided inside the concave portion 51 of the second holder 5 to press the second holder 5 in the axial direction.

[Operation] The shaft holder is supported by the first holder so as to be movable in a direction perpendicular to the axial direction of the main shaft, and when the shaft holder is moved in parallel in a direction perpendicular to the axial direction of the main shaft, Since the compression spring is bent in a direction perpendicular to the shaft, the shaft holding portion can be moved in parallel without tilting.

In addition, the tilting shaft is attached to a second holder fixed to the shaft holding part.
Since it is supported by a spherical bearing and the shaft end of the tilting shaft is pressed against the conical pivot by a thrust spring via a thrust ball, the cutting tool can be tilted together with the tilting shaft independently of the parallel movement of the second holder. I can do it.

Therefore, since the cutting tool is returned to its original position by the compression springs provided in two directions, one perpendicular to the main shaft and the other in the axial direction, the accuracy of returning to the origin is increased.

[Example] The present invention will be described with reference to embodiments shown in the drawings.

FIG. 1 is a front sectional view showing an embodiment of the present invention, in which a first holder 2 formed in a cup shape is fixed to the tip of a main shaft 1 of a processing tool. The bottom surface 22 of the cup-shaped recess 21 of the first holder 2 has a rolling groove 23 orthogonal to the axis of the main shaft l.
is provided.

The shaft holding portion 3 having a hollow portion is provided in the recessed portion 21, and one end surface 31 of the shaft holding portion 3 facing the bottom surface 22 of the first holder 2 has a rolling portion as shown in FIG. A rolling groove 32 similar to the groove 23 is provided.

While rolling in both the rolling groove 23 and the rolling groove 32,
A ball 4.4 is fitted between the first holder 2 and the shaft holder 3 so as to transmit torque. ball 4.4
are held by a retainer 41 so that the distance between the balls is maintained.

A gap is provided between the outer periphery of the shaft holder 3 and the inner periphery of the recess 21, and spring holes 33 are provided at positions perpendicular to the shaft at positions divided into four equal parts on the outer periphery of the shaft holder 3. . A compression spring 34 is inserted into the spring hole 33, and the compression spring 34 presses the shaft holding portion 3 from the inner circumference of the recess 21 in the axial direction via the ball 35. The opening of the recess 21 is provided with a screw that engages with a holding nut 24, and the holding nut 24 presses the shaft holding part 3 toward the bottom surface 22 via a thrust bearing 36, and the balls 4.4 fit into the rolling groove 23. This is to prevent it from coming off from the fitting of 32.

A shaft 52 is fixed to a hollow portion of the shaft holding portion 3 to which a second holder 5 having a cup-shaped recess 5I is attached. Recess 5
A conical pivot 54 is provided on the bottom surface 53 of the recess 51, and a spherical bearing 6 is provided on the stepped portion of the inner circumference of the recess 51. On the inner periphery between the bottom surface 53 of the recess 51 and the spherical bearing 6,
As shown in FIG. 3, a plurality of ball grooves 5 extending in the axial direction
5 is provided. The fixing part 61 of the spherical bearing 6 is located in the recess 5
1 through the screw provided in the opening of
is fixed to the inner periphery of the recess 51 by.

A tilting shaft 7 is fixed to the shaft hole of the movable part 62 of the spherical bearing 6. A disk portion 71 is formed at one end of the tilting shaft 7,
A spring hole 73 is provided in an end surface 72 of the disc portion 71 facing the pivot 54, into which a thrust spring 74 is inserted. A thrust ball 75 that rolls on the conical surface of the pivot 54 is inserted between the thrust spring 74 and the pivot 54, and the thrust spring 74 presses the tilting shaft 7 in the axial direction via the thrust ball 75. A ball groove 77 is provided in the outer circumferential surface 76 of the disc portion 71, passing through the ball groove 77 in the axial direction. The torque ball 79 is inserted into both the ball groove 77 and the ball groove 55 provided in the second holder 5, and the torque ball 79 is inserted into the recess 51.
The second holder 5 is held by two holding springs 78 and 78 provided between the bottom surface 53 and the spherical bearing 6, so that torque can be transmitted between the second holder 5 and the tilting shaft 7. The outer circumferential surface 76 of the disc portion 71 is sloped so as not to abut against the inner surface of the recess 51 when the tilting shaft 7 is tilted. A socket 9 for attaching a cutting tool 8 such as a tap is attached to the other end of the tilting shaft 7.

Now, when the tip of the cutting tool 8 enters the prepared hole H provided in the workpiece W, and the center line of the prepared hole H and the center line of the main shaft 1 of the processing tool deviate by an amount of eccentricity e, as shown in Fig. 4. As shown, the shaft holder 3 is supported by the thrust bearing 36 together with the tilting shaft 7 and the second holder 5 via the socket 9, and is displaced by an eccentric amount e while deflecting the compression spring 33. .

When the main shaft l is rotated by the processing tool in this state, the rolling groove 2
3 and the center of the rolling groove 32 are offset from each other, but since the ball 4 is fitted into both grooves, the torque from the main shaft 1 is transmitted to the shaft holder 3 while the ball 4 is moving. Shaft holding part 3
rotates eccentrically with respect to the main axis l, and the cutting tool 8 rotates together with the second holder 5 around the axis of the shaft holder 3.

After machining, the main shaft 1 is reversed and the cutting tool 8 is pulled up from the machined hole, but when it is pulled up, the shaft holding part 3 is moved in parallel by the eccentric amount e by the compression spring 33 and returns to the origin.

When the prepared hole H of the workpiece W is tilted by the tilt angle θ with respect to the main shaft 1, as shown in FIG.
At the same time, it enters the second holder 5 following the prepared hole H at an angle of inclination θ about the spherical bearing 6. At this time,
The thrust ball 75 moves its contact point from the center of the pivot 54 and is pressed to a point off the center of the conical surface, compressing the thrust spring 74.

When the main shaft 1 is rotated by the processing tool in this state, the shaft holder 3 rotates eccentrically with respect to the main shaft l as described above.
The second holder 5 rotates around the axis of the shaft holder 3,
The tilting shaft 7 and the cutting tool 9 are moved in a conical manner with their rotational shafts tilted relative to the second holder 5, and rotated while performing a so-called miso-suri motion.

After machining, when the cutter 8 is pulled up from the machined hole, the thrust spring 74 uses compression force to push the thrust ball 75 back to the center from the point off the center of the conical surface of the pivot 54, so the cutter 8 along with the tilting shaft 7 returns to the origin. be returned.

As described above, the shaft holder is supported by the first holder so as to be movable in a direction perpendicular to the axial direction of the main shaft, and the shaft holder is supported by the first holder so as to be movable in a direction perpendicular to the axial direction of the main shaft. Since the compression spring is designed to bend in a direction perpendicular to the shaft when the shaft is rotated, the shaft holding portion can be moved in parallel without tilting, and the accuracy of returning to the origin can be increased.

In addition, the tilting shaft is attached to a second holder fixed to the shaft holding part.
Since it is supported by a spherical bearing and the shaft end of the tilting shaft is pressed against the conical pivot by a thrust spring via a thrust ball, the cutting tool can be tilted together with the tilting shaft independently of the parallel movement of the second holder. This also makes it possible to return to the origin more reliably.

Also, the shaft holding part 3 is approximately 1 to 2 mm away from the first holder 2.
Since the cutting tool can be rotated at an angle of about 1 to 2 degrees with respect to the shaft holder, the permissible deviation length between the center line of the machined hole and the cutting tool can be increased.

In addition, instead of the tilting shaft 7, the direct socket 9 and the shaft holding part 3 are connected by a coil spring 70, as shown in FIG. 6, and the coil spring 70 is bent and tilted so that the cutting tool 8 follows the prepared hole. You can do it like this.

After machining, when the cutter 8 is pulled up from the machined hole, the coil spring 70 causes the cutter 8 along with the socket 9 to return to the origin due to the restoring force of the coil spring 70.

[Effects of the Invention] As described above, according to the present invention, the cutting tool can be tilted independently of parallel movement, and can be reliably returned to its origin, and the allowable length for positioning error can be increased, making it suitable for industrial use. When machining screws using a robot, the positioning of the cutting tool becomes easier and the machining time is reduced.

Brief Explanation of the First Drawing FIG. 1 is a front sectional view showing an embodiment of the present invention, and FIG.
3 is a sectional view along the ■-■ cross section shown in the figure, FIG. 3 is a sectional view along the ■-■ cross section, FIGS. 4 and 5 are illustrations of operation, and FIG. 6 is a front sectional view showing another embodiment. It is.

■ Main shaft, 2 First holder, 21 Recess, 22 Bottom, 23 Rolling groove, 24 Pressing nut, 3 Shaft holding part, 32... rolling groove, 33...
... Spring hole, 34 ... Compression spring, 35 ... Ball, 3
6... Thrust bearing, 4... Ball, 41... Retainer, 5... Second holder, 51... Recess, 52
... Mounting is on shaft, 53 ... bottom surface, 54 ... pivot, 55 ... ball groove, 6 ... spherical bearing, 7 ... tilting shaft, 71 ... disc part, 74 ...・Thrust spring, 7
5... Thrust ball, 77... Ball groove, 78...
...Holding spring, 79... Torque ball, 70... Coil spring, 8... Cutting tool, 9... Socket Figure 4 Figure 6

Claims (1)

[Claims] 1. A floating holder for holding a cutting tool on the main shaft of a processing tool, comprising: a cup-shaped first holder (2) fixed to the tip of the main shaft (1), and the first holder (2). ), and a compression spring (34) that presses the shaft in a direction perpendicular to the axial direction of the main shaft (1); The first holder (2) is provided with a thrust bearing (36) that supports the shaft holding portion (3) so as to be able to move in parallel in a direction perpendicular to the axial direction of the main shaft; A tilting shaft (7) having a cup-shaped second holder (5) fixed to the portion (3) and capable of transmitting torque from the second holder (5), and an axis of the main shaft (1). A spherical bearing (6) that supports the tilting shaft (7) so as to be tiltable in a direction, and a thrust spring (74) that presses the shaft holding part (3) in the axial direction are attached to the second holder (5). ) A floating holder characterized in that it is provided inside a recess (51). 2. The bottom surface (2) of the recess (21) of the first holder (2)
2) has a rolling groove (
23), a shaft holding part (3) having a hollow part in the recess (21), and one end surface (31) of the shaft holding part (3) facing the bottom surface (22) having the shaft holding part (3) provided with a hollow part; A rolling groove (32) facing the rolling groove (23) is provided, and the rolling groove (32) is fitted into both the rolling groove (23) and the rolling groove (32), and the first holder (2) A ball (4) for transmitting torque between the shaft holding part (3) and a retainer (41) for holding the ball is provided, and the outer periphery of the shaft holding part (3) and the recess (21) are provided. A compression spring (34) that presses the shaft holding part (3) in the axial direction via a ball (35) on the outer periphery of the shaft holding part (3), with a gap between the spring and the inner circumference.
), and a holding nut (24) for pressing the shaft holding part (3) toward the bottom surface (22) via a thrust bearing (36) is provided in the opening of the recess (21), and Department (
3) a second holder (
5) is fixed, and a conical pivot (
54), and a spherical bearing (6) is provided on the inner periphery of the recess (51) and fixed by a presser nut (56) provided at the opening of the recess (51), and the bottom surface (53) and A ball groove (55) extending in the axial direction is provided on the inner periphery between the spherical bearing (6) and a tilting shaft (55) is provided in the shaft hole of the movable part (62) of the spherical bearing (6).
7), a disk portion (71) is formed at one end of the tilting shaft (7), and a spring hole is formed in an end surface (72) of the disk portion (71) facing the pivot (54). (73), a thrust spring (74) is provided that presses the tilting shaft (7) in the axial direction via the thrust ball (75), and A ball groove (77) penetrating through the ball groove (77) is provided in both the ball groove (77) and the ball groove (55), and retaining springs (78), ( inserting a torque ball (79) held by the tilting shaft (78) so as to be able to transmit torque between the second holder (5) and the tilting shaft (7); 2. The floating holder according to claim 1, further comprising a socket (9) for attaching a cutting tool (8) to the other end. 3. In a floating holder that holds a cutting tool on the main shaft of a processing tool, a cup-shaped first holder (2) is fixed to the tip of the main shaft (1), and a torque is transmitted from the first holder (2). a compression spring (34) that presses the main shaft in a direction perpendicular to the axial direction of the main shaft (1); A thrust bearing (36) supporting the shaft holding part (3) is provided on the first holder (2) so as to be able to move in parallel in a direction perpendicular to the axial direction of the shaft holding part (3), and the tip of the shaft holding part (3) A floating holder characterized in that a coil spring (70) is provided between the socket (9) and the socket (9) for fixing the cutting tool (8).