JPS62837Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a structure that can withstand unbalanced loads in the clamped and unclamped states of the index table of a machine tool.

BACKGROUND TECHNOLOGY In general, an index table in a machine tool is a workpiece on which a workpiece is placed and fixed, and the index table is unclamped and rotated at a predetermined angle.
Thereafter, the index table is clamped, the workpiece is positioned, and a predetermined process is performed. The index table is provided with an indexing mechanism in order to accurately position the workpiece in the clamped and unclamped state.

The indexing mechanism of the conventional index table will now be described with reference to the accompanying drawings.

FIG. 1 shows the clamped state of the index table. In the drawings, reference numeral 1 denotes a central axis, and a flange portion 2 is formed approximately at the midpoint in the longitudinal direction. Reference numeral 3 designates a turning gear, the inner peripheral edge 4 of which is screwed onto the flange 2 of the central shaft 1. A ring-shaped protrusion 6 protruding downward is formed on the back surface of the outer peripheral edge 5 of this turning gear 3, and a toothed part 8 is formed on the outer circumferential surface of the lowermost end 7 of this ring-shaped protrusion 6.
A worm or pinion (not shown) is attached to the toothed portion 8.
are mated. 9 is an index table,
A T-slot 11 is provided on the top surface 10, and a workpiece (not shown) is placed on the top surface 10 of the index table 9 via a T-nut (not shown) fitted into the T-slot 11. It is tightened and fixed with bolts, etc. This index table 9 is fitted and fixed to the central shaft 1. Reference numeral 12a designates a precision coupling for indexing, which is a precision indexing plate for positioning for positioning a workpiece placed and fixed on the index table 9, and has teeth 14 on its lower surface 13a.
a, and is screwed near the outer periphery of the lower surface 15 of the turning gear 3. Reference numeral 16 denotes an upper thrust bearing, which is a bearing member, and is fitted onto the central shaft 1 and attached to the lower end surface of the base of the flange portion 2 of the central shaft 1. Reference numeral 17 denotes a first cylindrical member having a flange portion, which is fitted onto the central shaft 1, and the upper thrust bearing 16 is fitted into a recess 18 formed on the upper end surface of the first cylindrical member 17. ing. Note that the flange portion of the first cylindrical member 17 serves as a piston 19. Reference numeral 20 denotes a disc-shaped member having a ring-shaped projection 21 formed on its upper end surface, which is screwed onto the lower end surface 22 of the central shaft 1, and has a lower end portion of the first cylindrical member 17 inside the ring-shaped projection 21. 2
3 is inserted. Reference numeral 24 denotes a cylinder member, which has a recess formed on its inner circumferential surface, into which the piston 19 is fitted so as to be able to move up and down. The recess is separated by the piston 19 into an upper cavity 25 and a lower cavity 25'. A lower thrust bearing 26 is attached to the lower end surface of the cylinder 24. Reference numeral 27 denotes a table stand 27 having a cross-sectional shape as shown in the figure, and the outer peripheral surface of the cylinder member 24 is attached and fixed to this table stand 27. 12b is the precision coupling ring 12 for indexing.
This is a precision coupling ring for indexing, which is disposed opposite to A and is screwed to the upper end surface 28 of the table base 27, and has a tooth portion 14b on the upper surface 13b. Reference numerals 29 and 29' denote hydraulic pipes, which are bored in the table stand 27 and the cylinder member 24, respectively.The inlet and outlet of the pipe 29 open into the upper cavity 25 in the cylinder member 24, and the pipe 29 The inlet and outlet of ' are opened to a lower cavity 25' in the cylinder 24.

The operation of the conventional index table indexing mechanism having the above configuration will be described below with reference to the drawings.

FIG. 1 shows a state in which the index table is clamped. In this state, oil is sent from a hydraulic pump (not shown) along the pipe line 29 in the direction of the solid arrow in the figure, and the oil is pumped into the cylinder member 24. It is injected into the upper cavity 25. As a result, the piston 19 descends, and the central shaft 1 descends via the disc-shaped member 20. Then, the index table 9 and the turning gear 3 are lowered as well, and the turning gear 3 is lowered.
The teeth 14a of the precision indexing coupling 12a screwed to the lower end surface 15 of the table base 27 fit into the teeth 14b of the precision indexing coupling 12b screwed to the upper end surface 28 of the table base 27. Precision couplings 12a, 12b are clamped. As described above, the index table 9 is brought into a clamped state as shown in the figure, and a predetermined process is performed on the workpiece placed and fixed on the index table 9. After this predetermined machining is completed, the index table 9 must be rotated by a predetermined angle in order to perform the next machining. Therefore, in order to unclamp the index table 9, oil is fed from a hydraulic pump (not shown) along the pipe line 29' in the direction of the broken arrow in the figure, and the cylinder member 2
It is injected into the lower cavity 25 of No. 4. As a result, the piston 19 rises, and the central shaft 1 rises via the disc-shaped member 20. That is, the ring-shaped projection 21 of the disc-shaped member 20 rises until the outer upper end surface contacts the lower thrust bearing 26 . The index table 9 and the turning gear 3 are raised in the same way as the center shaft 1, and the gear 14a of the indexing precision coupling 12a screwed to the lower end surface 15 of the turning gear 3 is raised to the upper end surface of the table base 27. The precision indexing couplings 12a and 12b are separated upwardly from the teeth 14b of the precision couplings 12b screwed to the indexing precision couplings 12b, and the precision couplings 12a and 12b are unclamped. As described above, the index table 9 is in an unclamped state, and the worm or pinion is fitted into the teeth 8 provided on the outer peripheral surface of the lowermost end 7 of the ring-shaped protrusion 6 formed on the turning gear 3. (not shown) rotates by a predetermined angle, the turning gear 3 turns by a predetermined angle, and at the same time, the index table 9 rotates to determine the desired position relative to the workpiece, and the index table 9 is returned to the clamped state as described above. Then, perform the following processing.

However, in the conventional index table indexing mechanism described above, as shown in FIG. Precision coupling ring 1
Because it is small compared to the diameter D of 2a and 12b,
The moment difference became large, which placed a large constraint on the unbalanced load in the unclamped state. That is, the weight of the workpiece may be greater than the outer diameter of the upper thrust bearing, which is a bearing member, and may deviate outward, which places an excessive load on the bearing member, which adversely affects the flatness of the index table. In addition, when the index table 9 is in a clamped state for processing a workpiece, the upper end surface 10 of the index table 9 is not completely flat, and a concave flexure is generated in the center, and this flexure causes the workpiece to be It was not possible to accurately position the machine, resulting in a decrease in machining accuracy. In other words, in the clamped state of the index table, the center axis is pulled down and the index table is supported by pressing the back surface of the index table and the outer circumference against the table base, so a large force is applied to the center of the index table. acts to deform the center of the index table into a concave shape, which disturbs the flatness of the upper end surface of the index table. As described above, the conventional mechanism has the drawbacks that the ability to withstand unbalanced loads of the workpiece placed and fixed on the index table 9 is low and that the flatness of the index table becomes irregular.

Problems to be solved by the invention This invention has been developed in view of the above-mentioned conventional problems, and has been developed to improve the unbalanced load resistance of the workpiece placed and fixed on the index table, and to improve the ability of the index table to withstand unbalanced loads. An object of the present invention is to provide an unbalanced load-resistant structure for an index table that reduces flatness deviations.

Means for Solving the Problems The present invention provides a positioning precision indexing plate for positioning a workpiece placed and fixed on the index table with the index table in a clamped or unclamped state. The diameter of the bearing member that supports the load applied when unclamping the index table is made as close as possible to the diameter of the bearing member (the closer d/D is to 1, the larger the load capacity is), and It is characterized in that a large number of rollers are arranged radially around the index table support portion of each member. In this way, the above object can be easily achieved and sufficient effects can be obtained.

Embodiments The unbalanced load resistant structure of the index table device for a machine tool according to the present invention will be explained as follows based on the embodiments shown in the accompanying drawings.

FIG. 2 shows the clamped state of the index table. In the figure, 27' is a table base having a cross-sectional shape as shown, and 30 is a first cylindrical member having a flange portion 31 at its lower end, into which the central shaft 1 is fitted via a radial needle bearing 32. The flange portion 31 is attached to the table base 27'.
It is screwed on. 33 is a second cylindrical member having an outer circumferential flange portion, which is different from the first cylindrical member 30.
and is screwed onto the upper end surface of the flange portion 31 of the first cylindrical member 30. The first cylindrical member 30 and the second cylindrical member 33 constitute a support member that supports the central shaft 1 of the index table 9. Note that the flange portion of the second cylindrical member 33 serves as a piston 34. Reference numeral 35 denotes a cylinder member which is a bearing member, and a recess is formed on the inner circumferential surface, and the piston 34 is fitted into this recess, and the cylinder member 35 is provided so as to be movable up and down relative to the piston 34. There is. The recess is formed by the piston 34 into an upper cavity 36 and a lower cavity 3.
6'. A large number of rollers 38 are disposed radially around the upper outer circumferential surface of the cylinder member 35. Reference numeral 39 denotes a third cylindrical member, which is screwed on the lower surface 15 of the turning gear 3 close to the inside of the indexing precision coupling, and the roller 38 is inserted into a recess formed on the inner circumferential surface of the third cylindrical member. is inserted. Further, a cylinder member 35 is provided below the concave portion.
A disk-shaped member integrally formed with the lower part of the roller 38 is also fitted on the outside of the roller 38, and presses the third cylindrical member 39 downward. 40, 40' are hydraulic pipes, which connect the first and second cylindrical members 30, 33.
The outflow inlet of the pipe line 40 is connected to the cylinder 35.
The outlet opening of the pipe line 40 opens into the lower cavity 36' within the cylinder member 35. For configurations other than those mentioned above, the same reference numerals indicate the same parts as in the prior art.

The operation of the unbalanced load resistant structure of the index table device according to the present invention with the above configuration will be explained below.

Figure 2 shows the index table in a clamped state. In this state, oil is fed from a hydraulic pump (not shown) along the pipe 40' in the direction of the solid arrow in the figure, and the oil is pumped into the bearing member. It is injected into the lower cavity 36' within the cylinder member 35. As a result, the cylinder member 35 is lowered, the third cylindrical member 39 is pulled down, and the precision indexing coupling 12a is lowered via the turning gear 3. As a result, the indexing precision coupling 12
Tooth part 14a of indexing precision coupling ring 12b
The teeth 14b of the indexing precision coupling rings 12a, 12b are clamped. As described above, the index table 9 is brought into a clamped state as shown in the figure, and a predetermined process is performed on the workpiece placed and fixed on the index table 9. After completing this predetermined machining, the index table 3 must be rotated by a predetermined angle in order to carry out the next machining.
Therefore, in order to unclamp the index table 19, a hydraulic pump (not shown) is used.
From there, oil is fed along the pipe line 40 in the direction of the arrow shown by the broken line, and the oil is fed into the upper cavity 36 in the cylinder member 35.
injected into. As a result, the cylinder member 35 rises, and the roller 38 attached to the upper part of the cylinder member 35 pushes up the third cylindrical member 39, so that the precision indexing coupling 12a rises via the turning gear 3. , the tooth portion 14a of the precision index coupler 12a is separated upward from the tooth portion 14b of the precision index coupler 12b, and the precision index couplers 12a, 12b are unclamped. As described above, the index table 9 is in an unclamped state, and the worm or pinion ( (not shown) rotates by a certain angle, the turning gear 3 turns by a certain angle, and at the same time, the index table 9 is rotated to determine the desired position relative to the workpiece, and the index table 9 is clamped again as described above. condition and perform the next processing.

Effects of the Invention As explained above, in the present invention, the diameter of the precision indexing plate for positioning, which positions the workpiece placed and fixed on the index table with the index table in the clamped or unclamped state, is By making the diameters of the roller array of the bearing member, that is, the cylinder member, which supports the load applied when unclamping the index table as close as possible, the moment difference becomes smaller than in the past, and therefore It is possible to reduce the deflection of the upper end surface of the index table for processing a workpiece when the index table is in a clamped state or in an unclamped state. This makes it possible to accurately position the workpiece, dramatically improving machining accuracy, and overwhelmingly improves the unbalanced load resistance of the workpiece placed and fixed on the index table in the unclamped state. In addition, in this invention, by arranging a large number of inexpensive rollers radially around the circumference of the index table support member of the bearing member, sufficient effects such as being able to supply the index table which is a machine tool at a low cost are achieved. get.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an indexing mechanism of a conventional index table, and FIG. 2 is a sectional view showing an example of an indexing mechanism of an index table according to the present invention. 9... Index table, 12a, 12b
...Precision index plate for positioning, 35...Cylinder member (bearing member), 38...Roller, D...Diameter of precision index plate for positioning, d...Diameter of circular arrangement of rollers.

Claims (1)

[Scope of utility model registration request] An index table which has a turning gear fitted to a worm or pinion on the back side, and whose central axis is rotatably and vertically supported by the table base; and the turning gear and table cart. A machine tool comprising: a precision coupling for indexing consisting of a pair of precision indexing plates for positioning that are arranged in a circle on opposing surfaces and that engage and disengage as the index table moves up and down; and a means for moving the index table up and down. In the index table device, a support member is provided which supports the center axis of the index table and is integrally structured with the table base and has a piston integrally on the outer circumferential surface, and a rear surface of the rotation gear of the index table, and A third cylindrical member having a concave portion on the inner peripheral surface is installed close to the inner surface of the precision coupling for dispensing, and the third cylindrical member is provided so as to be movable up and down between the support member and the third cylindrical member, and the upper outer periphery is movable. A cylinder member of the piston includes a plurality of rollers arranged radially around the circumference of the surface, and a cylinder member of the piston having a disc-shaped member formed at the lower part of the roller row, and inside the recess of the third cylindrical member. . An unbalanced load resistant structure, characterized in that the roller and the disc-shaped member are positioned, and a hydraulic conduit is opened in the cylinder member and in the gap above and below the piston.