JPH032619B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a rotary indexing device used for indexing a small rotary table, indexing a rotary head, etc., and relates to a device that is small and capable of high-speed indexing.

Conventional technology The Geneva mechanism is widely used for rotary indexing of rotary tables, but in order to ensure accuracy and rigidity, a positioning means using locate pins is required, and since it is an external Geneva mechanism, it is large and requires timing control. This makes it impossible to speed up indexing.

Furthermore, it requires multiple driving sources and has a complicated structure.

Problems to be Solved by the Invention The object of the invention is to use a Geneva mechanism to perform simple, compact, and high-speed indexing.

Means for Solving the Problems In order to achieve the above object, the present invention employs an internal Geneva method in which the indexing drive part and the locking part are shifted in the axial direction, so that they can be freely rotated in a fixed frame such as a casing, base, or column. The Geneva wheel, which is supported on The Geneva arm, which is integrated with the drive shaft, has
A locking device consisting of an indexing member such as a roller that moves in and out of a radial groove to drive the Geneva wheel, an arcuate locking surface that is located within the rotation range of the locking roller and contacts the locking roller, and a notch that allows the locking roller to move. By fitting the Geneva wheel and Geneva arm in the axial direction, rotational indexing was achieved simply by turning the drive shaft.

Then, high-speed indexing is achieved using the inner Geneva method,
Intermittent indexing drive and indexing lock are achieved with a simple configuration of a Geneva wheel and a Geneva arm, and the objective is achieved with a single drive source.

Example The illustrated example is the drive shaft (output shaft) of a motor with a reducer.
Taking advantage of the fact that the motor is eccentric, the Geneva arm and Geneva wheel are housed in a casing with a cross section that is approximately the same shape as the motor, making it compact.

Referring to the drawings, a drive shaft 12 protrudes integrally with the motor 1 from the speed reducer 11 at an eccentric position.

The center hole 25 of the Geneva arm 2 is connected to this drive shaft 12.
The dog plate 8 is fixed with screws 27 and 81 using a key 13 to prevent displacement in the rotational direction. 26 is a groove into which a key is fitted, and 27' is a screw hole.

A locking wheel 21 consisting of a notch 23 and a locking surface 24 is provided in the middle of the Geneva arm 2, and a cam follower 22 is provided in a hole 22' at the upper end.
is installed.

On the other hand, a driven shaft 5 is rotatably supported by an angular bearing in a casing 6 that covers the Geneva arm 2 and is fixed to the reducer 11 without play.

7 is a bearing holder.

A center hole 51 and a positioning hole 5 are provided at the lower end of the driven shaft 5.
2, a center pin 41 and a positioning pin 42 are fitted therein, and the support plate 4 is fixed with screws 43.

A substantially cup-shaped Geneva wheel 3 is mounted on the support plate 4.
is fitted in the recess 33 and fixed by the pudge 35.

The Geneva wheel 3 has a center hole 31 and a cross-shaped radial groove 32 formed therein, and a cam follower 34 is attached to a hole 34' at the lower end.

35' is a screw hole.

The cam follower 22 is located at the radial groove 32 and the center hole 31, and the locking wheel 21 is located at the cam follower 34.

A notch 61 is provided at one location on the open end of the casing 6.
is formed, and a sensor 9 (proximity switch) attached to the holder 91 enters to detect the dog plate 8.

When assembling as shown in the first figure, the Geneva arm 2 may be inserted near the center of the Geneva wheel 3 (shifting the Geneva wheel slightly to the left in the figure) and then moved to the position shown in the figure.

In this embodiment, such an assembly is possible, but
If the index table cannot be moved, as shown by the one-dot chain line in FIG.
If the Geneva arm 2 is inserted from here, it can be assembled without shifting.

The reason why the stubs 36 are provided at two locations is to improve the ease of assembly by providing two locations where assembly can be performed.
It can be anywhere.

Next, the operation will be explained. Figures 1 and 2 show the indexing operation in progress, and Figure 3 shows the indexing completed state. The drive shaft 12 is designed to stop when the sensor 9 detects the dog plate 8. Figure 3 shows the drive shaft 12
rotates clockwise, the sensor 9 detects the dog plate 8, and the motor 1 is stopped. At this point, the cam follower 22 is located in the center hole 31 of the Geneva wheel, and the two cam followers 34, 34 lock the locking wheel. The contact surface 24 makes it impossible for the Geneva wheel 3 to rotate.

The driven shaft 5 is therefore indexed.

When performing the next indexing from this state, the motor 1 is driven to rotate the Geneva arm 2.

With this rotation, the cam follower 22 enters the radial groove 32 from the center hole 31 and rotates the Geneva wheel 3 by 90 degrees.

After turning 90 degrees, the cam follower 22 enters the center hole 31 again and the Geneva wheel 3 stops.

During this operation, one side of the cam follower 34 faces the notch 23 and the other side faces the lock surface 24, allowing the Geneva wheel 3 to rotate freely, and when it has turned 90 degrees, the two cam followers 34, 34 come into contact with the lock surface 24. At this time, the sensor 9 detects the dog plate 8, stops the motor 1, and completes the indexing.

In this example, the dog plate 8 is formed wide,
The above operation is possible no matter which direction the drive shaft rotates, a motor stop signal is output from the sensor 9, and the shaft 12 rotates a little until the motor stops, but the cam followers 34 and 34 come in contact with the lock surface. The condition of Geneva arm 2 does not change even if its position deviates slightly from that shown in FIG.

Modified Example FIG. 9 shows a modified example in which the position of the locking wheel 21 and the position of the locking roller 340 are on the lower side.

A bearing 220 is attached to the upper end of the Geneva arm 2, and a bearing 340 is attached downward to the lower end of the Geneva wheel 3, each having the same function as the cam follower.

Further, the dog 800 is configured to control a micro switch 900.

The micro switch 900 is fixed to a holder 910, and the holder 910 is fixed to the reducer 11 together with the casing 6.

The operation of this example is similar to that of the above example, but this structure improves machining and assembly, and since the locking wheel is brought closer to the motor, the locking rigidity is also improved.

In addition, in the above example, (1) The number of locking rollers (cam followers, bearings, etc.) is not limited to the number of indexes; for example, they may be doubled and each roller may be used exclusively for the indexing position.

(2) The drive shaft is not limited to the output shaft of the motor, but also includes gears,
It may also be transmitted from another source using a belt, etc.
This configuration is particularly easy to use for table indexes and the like.

(3) The Geneva wheel may be divided into parts and assembled into one piece, and workability will be improved if the radial grooves extend all the way to the outer periphery.

Effects The present invention is as described above; it is compact and has a simple configuration; it can speed up indexing by using the internal Geneva method; and it can achieve high precision with a single drive source without requiring separate locking means. It has various effects such as being able to perform indexing.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the present invention, Fig. 2 is a sectional view in the middle of indexing, Fig. 3 is a sectional view of the indexed state, Fig. 4 is a plan view of the Geneva wheel, and Fig. 5 is the same cross section. 6 is a bottom view of the same, FIG. 7 is a sectional view of the Geneva arm, FIG. 8 is a bottom view of the same, and FIG. 9 is a sectional view of a modified example. 5 is a driven shaft, 6 is a casing, 8 is a dog plate, and 9 is a sensor.

Claims (1)

[Claims] 1. A Geneva wheel is rotatably supported on a frame,
The Geneva wheel is provided with equally spaced radial grooves passing through the center and locking rollers of at least the number of radial grooves on the same circumference, shifted in the axial direction, and the Geneva arm is fixed to a drive shaft provided at an eccentric position, The Geneva arm is provided with an eccentric indexing member that enters and exits the radial groove, and a locking wheel that is located within the rotation range of the locking roller and consists of a locking surface that comes into contact with the locking roller and a notch that allows the locking roller to move. , a rotary indexing device offset in the axial direction. 2. The rotary indexing device according to claim 1, wherein the indexing member is a rotatable roller provided at an eccentric position of the Geneva arm.