JP2023150468A - Positioning turn table device - Google Patents

Abstract

To provide a rotary positioning turn table device which can constantly maintain a state where no gap exists when a rotary table is stopped and has a simple structure.SOLUTION: A positioning turn table device includes: a rotary table having a slide surface; a device body having a holding surface which faces the slide surface of the rotary table and is perpendicular to a center axis in a vertical direction and configured to hold the slide surface of the rotary table with the holding surface; an oil groove which is formed on at least one of the holding surface and the slide surface so as to extend on a circumference around the center axis; a hydraulic mechanism which supplies an oil to the oil groove and applies a predetermined oil pressure; and a drive mechanism which is disposed at the device body and applies drive force to the rotary table. The above problem is solved by the positioning turn table device.SELECTED DRAWING: Figure 1

Description

The present invention relates to a positioning turning table device.

Patent Document 1 (Japanese Unexamined Patent Publication No. 2020-60248) and Patent Document 2 (Japanese Patent Application Laid-open No. 5128314) disclose a circle that can guarantee the rotation angle of the rotary table with high accuracy when the rotating disk-shaped rotary table rotates. A table apparatus is disclosed. The rotary table devices disclosed in these patent documents are devices that rotate a rotary table around a vertical axis using a drive mechanism such as a servo motor that rotates around an axis perpendicular to the vertical direction.

Patent Document 1 discloses a so-called barrel cam type rotary table device. In a barrel cam type rotary table device, cam followers are arranged intermittently around the circumference of a rotating rotary table, and a cam shaft is connected to a motor and has a spiral cam groove that fits into the cam follower. The rotary table is rotated by the movement of the cam follower in the cam groove by the rotation of the camshaft.

Further, Patent Document 2 discloses a ball reducer which is a drive mechanism that rotates around a rotating rotary table in which bearings are arranged on the circumference and a worm gear that extends along an axis perpendicular to the vertical direction. discloses a rotary table device that rotates a rotary table.

JP2020-60248A Patent No. 5128314 specification

For example, in conventional rotary table devices typified by Patent Document 1 and Patent Document 2, a thrust bearing is disposed below the rotary table in order to reduce frictional force caused by vertical loads. In particular, the thrust bearing for the rotary table of the rotary table device supports a large load, so it naturally becomes large in size, and the cost of bearing parts increases.

Furthermore, if the thrust bearing is pressed by the clamp mechanism when the rotary table is stopped, deformation due to the pressing force is unavoidable. Deformation of the thrust bearing leads to deformation of the upper surface of the table surface, making it impossible to achieve highly accurate positioning.

In conventional rotary table mechanisms typified by Patent Document 1 and Patent Document 2, the cam groove and the cam follower are fitted in such a manner that there is no gap. If a gap occurs, it will lead to a decrease in positioning accuracy.

Generally, it is not easy to maintain a state where there is no gap at all times when the cam groove and the cam follower fit together, both when turning and when stopping.

On the other hand, when operating a rotary table, there are overwhelmingly many uses that require precision in the stopping angle when stopping. It is easier to manufacture the fit between the cam groove and the cam follower so that there is no gap only when the cam is stopped, compared to a method that maintains a state where there is no gap at all times both when turning or when the cam follower is stopped.

In other words, in order to ensure high rotation angle accuracy and high position accuracy both when the rotary table rotates and when it stops, high accuracy is required in all processes of design, parts processing, and assembly, which increases costs. A problem arises. For example, if an index table device is realized using the rotation mechanism of a conventional rotary table device such as those disclosed in Patent Document 1 and Patent Document 2, in order to achieve high accuracy in design, parts processing, and assembly, it is necessary to The entire process is time-consuming and costly.

Therefore, there is a need for a rotary positioning table device with a simple structure that can maintain a gap-free state at all times when stopped.

a rotary table having a sliding surface; a holding surface that faces the sliding surface of the rotary table and is perpendicular to a vertical central axis; the sliding surface of the rotary table is held by the holding surface; an oil groove formed in at least one of the holding surface or the sliding surface so as to extend circumferentially around the central axis; The problem is solved by a positioning turning table device including a hydraulic mechanism capable of applying hydraulic pressure and a drive mechanism disposed in the device main body and applying driving force to the rotary table.

According to the present invention, it is possible to realize a rotary positioning swivel table device with a simple structure that can always maintain a gap-free state when the rotary table is stopped.

1 shows a positioning turning table device 1 which is an embodiment of the present invention. 1 is a cross-sectional view of a positioning turning table device 1 according to an embodiment of the present invention, taken along the cross-section AA in FIG. 1. FIG. 1 is a cross-sectional view of a positioning turning table device 1 according to an embodiment of the present invention, taken along the cross-section BB in FIG. 1. FIG. It is a figure showing the oil groove 33 of the positioning turning table device 1 which is an embodiment of the present invention. FIG. 3 is a diagram showing an example in which an oil reservoir 33a is arranged in an oil groove 33 of the positioning rotary table device 1 according to an embodiment of the present invention. FIG. 3 is a diagram showing an example in which an oil reservoir 33b is arranged in an oil groove 33 of the positioning rotary table device 1 according to an embodiment of the present invention. 2A is an enlarged view of a portion of the hydraulic mechanism 6 in the cross-sectional view of the positioning turning table device 1 shown in FIG. 2A, showing a state in which the piston cylinder 62 is retracted from the oil chamber 61. FIG. 2A is an enlarged view of a portion of the hydraulic mechanism 6 in the sectional view of the positioning turning table device 1 shown in FIG. 2A, showing a state in which the piston cylinder 62 has entered the oil chamber 61. FIG. FIG. 2 is an enlarged cross-sectional view of a cam groove 51 and a cam follower 52 as an example of the drive mechanism 5 of the positioning turning table device 1 according to the embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a cam groove 51 and a spherical cam follower 53 as an example of the drive mechanism 5 of the positioning turning table device 1 according to the embodiment of the present invention.

[Embodiment]
(Positioning turning table device 1)
A positioning turning table device 1 as an embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. FIG. 1 shows a positioning turning table device 1 which is an embodiment of the present invention. FIG. 2A is a sectional view of the positioning turning table device 1 according to the embodiment of the present invention, taken along the cross section AA in FIG. 2 is a cross-sectional view of the turning table device 1, taken along the cross-section BB in FIG. 1. FIG.

The positioning turning table device 1 includes a rotary table 2, a device main body 3, a drive mechanism 5, and a hydraulic mechanism 6. The positioning turning table device 1 has a positioning state and a non-positioning state. The positioning state is a state in which the rotary table 2 is stopped and positioned at a predetermined position with high precision, and the rotary table 2 is held and fixed. The rotary table 2 is a positioning table having a disk-shaped surface set horizontally. It is arranged to be rotatable around the center of the disk shape.

The predetermined position is a position rotated by a predetermined angle from a predetermined reference axis on the surface of the rotary table 2 around the rotation center axis. The non-positioning state is a state other than the positioning state, and includes a state in which the rotary table 2 is actually rotating to position it at a predetermined position (operating state), and a state in which it is not actually rotating but has started rotating. It includes a preparation state and a preparation state (preparation state) in which rotation is stopped and the positioning state is entered.

(Rotary table 2)
The rotary table 2 is capable of continuous rotation, but during rotation during operation in the positioning operation state, it rotates within a maximum range of 180 degrees as indicated by the arrow in FIG. The center of the disk-shaped surface is defined as the center axis in the vertical direction, which is the center of rotation of the rotary table. The disk-shaped surface is the uppermost surface in the vertical direction, and a workpiece can be clamped on the disk-shaped surface.

The rotary table 2 has a sliding surface 2a. The sliding surface 2a is typically a surface formed on the opposite side of the disk-shaped surface, a surface parallel to the disk-shaped surface, and a surface extending in the horizontal direction.

(Device body 3)
The apparatus main body 3 has a holding surface 3a that is a horizontal surface that faces the sliding surface 2a of the rotary table 2 and is perpendicular to the vertical central axis. The holding surface 3a is, for example, a donut-shaped surface, and a rotary shaft mechanism that defines the rotation axis of the rotary table 2 is inserted into a hole in the center of the donut portion, and is held by, for example, a bearing. Thus, rotation of the rotary table 2 is guaranteed.

The sliding surface 2a of the rotary table 2 is supported and held by the holding surface 3a of the apparatus main body 3. Thereby, the rotary table 2 is rotatably held by the apparatus main body 3 such that the sliding surface 2a of the rotary table 2 slides on the holding surface 3a of the apparatus main body 3.

Next, the oil groove 33 will be explained with reference to FIGS. 3A to 3C. FIG. 3A is a diagram showing the oil groove 33 of the positioning rotary table device 1 according to the embodiment of the present invention. FIG. 3B is a diagram showing an example in which an oil reservoir 33a is arranged in the oil groove 33 of the positioning turning table device 1 according to the embodiment of the present invention. FIG. 3C is a diagram showing an example in which an oil reservoir 33b is arranged in the oil groove 33 of the positioning turning table device 1 according to the embodiment of the present invention.

As shown in FIG. 4A, the holding surface 3a includes an oil groove 33 formed circumferentially around the central axis so as to extend over the entire circumference. The oil groove 33 is formed as a groove having a uniform depth on the holding surface 3a. The oil groove 33 is arranged on the holding surface 3a over the entire circumference of the rotary table 2. As will be described later, oil (lubricating oil) is supplied to the oil groove 33, and the oil (lubricating oil) is supplied to the entire area between the sliding surface 2a of the rotary table 2 and the holding surface 3a of the device main body 3. Ru.

The oil groove 33 is as shown in FIG. The groove width is typically the same width, but as long as oil (lubricating oil) can be supplied to the entire area between the sliding surface 2a of the rotary table 2 and the holding surface 3a of the device main body 3, it is not necessarily the same width over the entire area. It doesn't have to be the same width. The oil groove 33 may have an oil reservoir 33a having a large groove width disposed in a part thereof. As an example of an oil reservoir 33a having a large width, circular oil reservoirs 33a as shown in FIG. 4B can be arranged at various locations in the oil groove 33, for example. The oil reservoir 33a can typically be circular, but the shape is not limited as long as the volume of the oil reservoir 33a is defined as a partially large portion. For example, the oil reservoir 33b may have an elongated shape as shown in FIG. 4C.

The oil groove 33 is typically arranged only on the holding surface 3a. However, as long as they are arranged circumferentially around the central axis, they may be arranged partially on the sliding surface 2a. That is, the oil grooves 33 can be arranged alternately on the sliding surface 2a and the holding surface 3a, and thereby arranged along the entire circumference around the central axis.

The oil groove 33 has an opening over the entire circumference, and the opening is always located between the sliding surface 2a of the rotary table 2 and the holding surface 3a of the device main body 3. If the oil groove 33 is arranged on the holding surface 3a, the sliding surface 2a of the rotary table 2 will be in contact with the opening of the oil groove 33, and if the oil groove 33 is arranged on the sliding surface 2a, the oil groove 33 will be in contact with the opening of the oil groove 33. 3a also contacts the opening of the oil groove 33.

(Hydraulic mechanism 6)
Next, the hydraulic mechanism 6 will be explained with reference to FIGS. 2A, 4A, and 4B. FIG. 4A is an enlarged view of the hydraulic mechanism 6 in the cross-sectional view of the positioning turning table device 1 shown in FIG. It is. FIG. 4B is an enlarged view of the hydraulic mechanism 6 in the cross-sectional view of the positioning turning table device 1 shown in FIG. 2A, showing a state in which the piston cylinder 62 has entered the oil chamber 61. It is.

The device main body 3 includes a hydraulic mechanism 6 that supplies oil (lubricating oil) to the oil groove 33. The hydraulic mechanism 6 includes an oil chamber 61, a piston cylinder 62, and an oil conduit 63. The oil chamber 61 and the oil groove 33 are fluidly communicated through an oil conduit 63. The oil conduit 63 is provided with a check valve 63a that supplies oil to the oil groove 33 and prevents the oil supplied to the oil groove 33 from flowing back.

The oil chamber 61 is arranged at the tip of the piston cylinder 62 such that the piston cylinder 62 is inserted into the oil chamber 61. The oil supply source and the oil chamber 61 are in fluid communication through an oil conduit 64. The inside of the oil chamber 61 is filled with oil. The oil conduit 64 supplies oil from the oil supply source to the oil chamber 61, and is equipped with a check valve 64a that prevents the oil supplied to the oil chamber 61 from flowing back to the oil supply source.

The piston cylinder 62 of the hydraulic mechanism 6 operates to repeatedly advance and retreat within the oil chamber 61. As shown in FIG. 4A, as the piston cylinder 62 retreats from the oil chamber 61, the volume of the oil chamber 61 expands and the oil pressure in the oil chamber 61 decreases. Then, oil is introduced into the oil chamber 61 from an oil supply source to supplement this.

As shown in FIG. 4B, when the piston cylinder 62 is pushed into the oil chamber 61 and advances, the volume of the oil chamber 61 is compressed, and the oil pressure in the oil chamber 61 increases. Here, the check valve 64a prevents the oil supplied to the oil chamber 61 from flowing back to the oil supply source.

Subsequently, the piston cylinder 62 retracts from the oil chamber 61 and further oil is introduced into the oil chamber 61 from the oil supply source, but here, the check valve 63a causes the oil supplied to the oil groove 33 to There is no backflow to chamber 61.

When the rotary table 2 is turned, the hydraulic mechanism 6 increases the oil pressure in the oil chamber 61 due to the forward and backward movement of the piston cylinder 62 at the start of the turn, and supplies oil to the oil groove 33 at a predetermined oil pressure. That is, by pushing the tip of the piston cylinder 62 into the oil chamber 61, oil in the oil chamber 61 is introduced into the oil groove 33 through the oil conduit 63. At this time, the sliding surface 2a of the rotary table 2 is pushed up against the holding surface 3a of the device main body 3 due to the pushing pressure of the oil into the oil groove 33, and the sliding surface 2a of the rotary table 2 is pushed up against the holding surface 3a of the device main body 3. It is separated from the holding surface 3a. That is, when the hydraulic mechanism 6 operates, an oil film is formed between the sliding surface 2a and the holding surface 3a formed by the oil supplied to the oil groove 33. By supplying oil to the oil groove 33, the rotary table 2 is slightly raised by the amount of oil film. Since oil is supplied to the oil groove 33 and an oil film is formed between the sliding surface 2a and the holding surface 3a, the sliding surface 2a and the holding surface 3a are in a non-contact state from a microscopic perspective. . Strictly speaking, when the rotary table 2 rotates in this state, the sliding surface 2a and the holding surface 3a move relative to each other without contacting each other. The sliding surface 2a and the holding surface 3a are held by contacting each other through an oil film formed between the sliding surface 2a and the holding surface 3a, and the rotary table 2 rotates. Sometimes, the sliding surface 2a is expressed as sliding against the holding surface 3a.

(Drive mechanism 5)
Next, the drive mechanism 5 will be described with reference to FIGS. 2B, 5, and 6. FIG. 5 is an enlarged cross-sectional view of a cam groove 51 and a cam follower 52 as an example of the drive mechanism 5 of the positioning turning table device 1 according to the embodiment of the present invention. FIG. 6 is an enlarged cross-sectional view of a cam groove 51 and a spherical cam follower 53 as an example of the drive mechanism 5 of the positioning turning table device 1 according to the embodiment of the present invention.

The device main body 3 includes a motor 4 and a drive mechanism 5. The motor 4 applies driving force to the drive mechanism 5, and the drive mechanism 5 applies the driving force received from the motor 4 to the rotary table 2. This driving force causes the rotary table 2 to rotate around the central axis.

The drive mechanism 5 includes a drive shaft 50 that is connected to the motor 4, has a rotation center axis that is perpendicular to the vertical direction, and extends rotatably around the rotation center axis. The drive shaft 50 has a cam groove 51 on its periphery. The cam groove 51 is typically a helical cam groove having a predetermined width defined between threads.

The rotary table 2 includes a cam follower 52 that fits into the cam groove 51. A plurality of cam followers 52 are arranged circumferentially around the rotation center of the rotary table 2. The number of cam followers can be determined based on the ratio of the rotary table rotation angle to the drive shaft rotation angle and the reduction ratio.

The cam follower 52 has a tapered shape that is thickest at the base and tapers toward the rotation center of the drive shaft 50. That is, for example, the cam follower 52 typically has a truncated conical shape as shown in FIG. 5, and its cross section is tapered.

Further, at this time, the taper angle of the cam groove 51 can be set according to the shape of the cam follower 52. The angle of the upper entrance of the cam groove 51 is gentle, and a plurality of tapered angles of inclination are formed toward the rotation center of the drive shaft 50 so that the angle becomes steeper depending on the depth direction of the cam groove 51. It can be set to have an inclination angle of .

For example, typically in a non-positioning state, when oil is supplied to the oil groove 33, the cam follower 52 rises due to the oil film formed between the sliding surface 2a and the holding surface 3a. It is separated from the cam groove 51 by a gap corresponding to the oil film. On the other hand, in the positioning state, the oil to the oil groove 33 is stopped, the oil film formed between the sliding surface 2a and the holding surface 3a disappears, and the sliding surface 2a and the holding surface 3a come into contact with each other. The cam follower 52, which had been raised by the same amount, approaches the cam groove 51.

The width of the base of the cam follower 52 (in the case of a typical truncated cone shape, the diameter) is such that the oil supply to the oil groove 33 is stopped and the oil film formed between the sliding surface 2a and the holding surface 3a is The width of the cam groove 51 is set so that the sliding surface 2a and the holding surface 3a are in contact with each other and are in an interference fit with the width of the cam groove 51. The cam groove 51 only needs to be in contact with the cam follower 52 without a gap when the rotary table 2 is fixed in the positioning state.

The clamp mechanism 31 includes a clamp head 31a. The clamp head 31a has, for example, a hollow donut-like shape. The rotary table 2 includes a radially protruding flange 2b at least in part, preferably over the entire circumference. The rotary table 2 is a hollow part of the clamp head 31a, and is inserted into the vertically upper side of the flange 2b.

In the positioning state where oil is stopped flowing into the oil groove 33, the sliding surface 2a and the holding surface 3a are in contact with each other. In this state, the clamp mechanism 31 moves the clamp head 31a toward the sliding surface 2a, and applies a pressing force to the sliding surface 2a with the clamp head 31a. The sliding surface 2a is pressed against the holding surface 3a by the pressing force applied by the clamp head 31a, and the rotary table 2 is placed in a state where the rotary table 2 cannot rotate (clamped state).

Contrary to the clamped state, in the non-positioning state, in preparation for rotating the rotary table 2, the clamp mechanism 31 moves the clamp head 31a away from the sliding surface 2a, and the clamping mechanism 31 moves the clamp head 31a away from the sliding surface 2a. Release the pressure on the By releasing the pressing force from the clamp head 31a, the sliding surface 2a becomes in a state where its movement with respect to the holding surface 3a is not restricted, and the rotary table 2 is placed in a rotatable state (unclamped state).

In the unclamped state of the clamp mechanism 31, the clamp head 31a releases the pressing force on the sliding surface 2a, so oil is supplied to the oil groove 33 with a predetermined hydraulic pressure by the hydraulic mechanism 6, and the sliding surface 2a and the clamp head 31a are released. An oil film is formed between the cam groove 51 and the cam follower 52, and a gap is created between the cam groove 51 and the cam follower 52, allowing smooth rotation without resistance to rotational movement.

That is, in the present invention, when the hydraulic mechanism 6 stops supplying oil to the oil groove 33, the oil film between the sliding surface 2a and the holding surface 3a disappears, and the width of the cam groove 51 and the width of the cam follower 52 disappear. As a result, so-called backlash gaps are eliminated, and highly accurate positioning is possible. When the hydraulic mechanism 6 stops supplying oil to the oil groove 33 and there is no oil film between the sliding surface 2a and the holding surface 3a, the clamping mechanism 31 holds the sliding surface 2a of the rotary table 2. It is pressed and fixed against the surface 3a.

When oil is supplied to the oil groove in the hydraulic mechanism 6, an oil film is formed between the sliding surface 2a and the holding surface 3a, and the sliding surface 2a rises from the holding surface 3a by the thickness of the oil film. A gap is created between the width of the cam groove 51 and the width of the cam follower 52, and this gap becomes backlash, and the engagement between the cam groove 51 and the cam follower 52 becomes smooth, eliminating resistance to rotational movement. , smooth rotation is possible. That is, the relationship between the tapered shape of the cam follower 52 and the cam groove 51 depends on the thickness of the oil film between the sliding surface 2a and the holding surface 3a depending on whether or not oil is supplied to the oil groove 33 by the hydraulic mechanism 6. , is defined to correspond to the presence or absence of a gap between the width of the cam groove 51 and the width of the cam follower 52.

According to the present invention, costs can be reduced, the amount of deformation of the rotary table can be greatly reduced, and deformation of the upper surface of the rotary table can also be reduced.

The tapered shape of the cam follower 52 may be a shape that tapers linearly toward the center of the drive shaft 50, such as a truncated cone shape as described above, that is, a shape other than a tapered cross section. For example, the tapered shape may be a curved shape that tapers toward the center of the drive shaft 50. Furthermore, in this case, in particular, the curved surface can be a spherical surface.

When the tapered shape is a spherical surface, as shown in FIG. 6, a spherical hole may be bored in the rotary table 2, and a spherical cam follower 53 such as a steel ball may be attached to the rotary table. In this case, the diameter of the spherical cam follower such as a steel ball may be read as the width of the base of the truncated cone-shaped cam follower 52. The spherical cam follower 53 also has a spherical curved surface, and has the same effect as a curved surface that is thickest at the root and tapers toward the center of rotation of the drive shaft 50.

Even in this case, the supply of oil to the oil groove 33 is stopped, the oil film formed between the sliding surface 2a and the holding surface 3a disappears, and the sliding surface 2a and the holding surface 3a come into contact with each other. It is only necessary to set the width of the cam groove 51 so that the width of the cam groove 51 and the width of the cam groove 51 are tightly fitted.

1 Positioning turning table 2 Rotary table 2a Sliding surface 3 Device body 3a Holding surface 31 Clamp mechanism 31a Clamp head 32 Bearing 33 Oil groove 4 Motor 5 Drive mechanism 50 Drive shaft 51 Cam groove 52 Cam follower 6 Hydraulic mechanism 61 Hydraulic chamber 62 Piston Cylinder 63 Oil conduit

Claims (8)

a rotating table having a sliding surface;
an apparatus main body having a holding surface perpendicular to a vertical central axis opposite to the sliding surface of the rotating table, and holding the sliding surface of the rotating table with the holding surface;
an oil groove formed in at least one of the holding surface or the sliding surface so as to extend circumferentially around the central axis;
a hydraulic mechanism capable of supplying oil to the oil groove and applying a predetermined hydraulic pressure;
A positioning turning table device comprising: a drive mechanism disposed in the device main body and applying driving force to the rotary table. The positioning turning table device according to claim 1,
The hydraulic mechanism supplies oil to the oil groove, and in a state where an oil film is formed between the sliding surface and the holding surface formed by the oil, the sliding surface of the rotary table is connected to the holding surface. A positioning rotary table device in which the rotary table is held by a surface and rotates around the central axis by the driving force. The positioning turning table device according to claim 1, wherein the drive mechanism comprises:
a drive shaft connected to the motor and having a cam groove portion on its periphery;
a cam follower disposed on the rotary table and fitted into the cam groove;
The cam follower has a tapered shape toward the center of rotation of the drive shaft. The positioning turning table device according to claim 3,
When the hydraulic mechanism stops supplying oil to the oil groove, the oil film between the sliding surface and the holding surface disappears, and the cam groove matches the width of the cam follower. The positioning turning table device according to claim 3,
When the hydraulic mechanism is supplying oil to the oil groove, the sliding surface rises from the holding surface by the thickness of the oil film between the sliding surface and the holding surface, and the cam groove and the cam A positioning turning table device that creates a gap between the width of the follower and the width of the follower. The positioning turning table device according to claim 3,
a positioning rotation comprising a clamp mechanism for fixing the rotary table to the device main body in a state where the hydraulic mechanism stops supplying oil to the oil groove and there is no oil film between the sliding surface and the holding surface; table equipment. The positioning turning table device according to any one of claims 1 to 6,
The hydraulic mechanism includes a piston cylinder, an oil chamber disposed at the tip of the piston cylinder and filled with the oil, and an oil conduit that fluidly communicates the oil groove and the oil chamber,
A positioning turning table device in which the oil in the oil chamber is introduced into the oil groove through the oil conduit by pushing the tip of the piston cylinder into the oil chamber. 7. The positioning turning table device according to claim 3, wherein the tapered shape is a curved surface.

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