JPH03144151A - Positioning device - Google Patents

Abstract

PURPOSE:To obviate a motor which is exclusively used for positioning by installing a position correcting holding mechanism which restrains a driven body at a prescribed position with high reproducibility during the stop period of the driven body,on a driving shaft connected through a gear with the input shaft of a Geneva gear device. CONSTITUTION:The driving wheel 16a of a Geneva gear device 16 is driven by an input shaft 16b driven by a motor 18, and a driven wheel 16c is revolved intermittently by 1/4 revolution for one revolution of the driving wheel 16a. A turntable 11 is connected with the output shaft 16d of the driven wheel 16c. Four holes 15 for the engagement of a pin are drilled at equal intervals in the circumferential direction on the turntable 11. A driving shaft 20 is connected through a bevel gear 17 with the input shaft 16b, and a cam 19 is connected with the driving shaft 20, and the cam 19 is turned in one revolution during one revolution of the input shaft 16b, and a positioning pin 12 is raised and lowered in correspondence with the revolution of the cam 19. The period in which the positioning pin 12 is raised and inserted into the engagement hole 15 is adjusted so as to be equal to the stop period of the turntable 11, and correct positioning is performed.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention is applicable to all industrial fields, such as handling, delivery, processing, testing and inspection of articles, etc., in which articles are placed one after another at a fixed pitch in a fixed position. The present invention relates to a positioning device used in a process that requires stopping.

(Conventional technique fr) When stopping and positioning an article continuously and accurately at a certain position, it is necessary to simply detect the stopping position, turn off the motor,
If you just apply the brakes at the same time to stop the vehicle, there will be variations in overrun.

Due to play in the power transmission system, it is difficult to accurately ensure the stopping position, and there is usually a position error of several millimeters to more than ten millimeters.

Conventionally, in order to improve the stopping position accuracy, the stopper, positioning pin, clamp mechanism, etc. were operated by a drive system separate from the drive of the main body, and the stopping position of the driven object that had stopped - degree was corrected. has been used.

An example of this positioning device is shown in Fig. 3. This positioning device accurately stops the rotary table every 1/3 rotation, and the nine-rotary table (1) is driven by a motor (9) via a gear (8). be done. The brake (10) is used to reduce overrun when stopping and keep the stopped position.To stop at a predetermined position, the dog (3) fixed to the rotary table (1) is connected to the position sensor (2). ) is detected.

To correct the position of the rotary table to an accurate position after it has stopped, release the brake (10) to release the restraint of the rotary table (1), and then use another motor (7) to move the rotary table (1) through the rack and pinion (6). to raise the positioning pin (4), and insert the positioning pin (4) into the guide hole (5) of the rotary table (1).
) to engage and insert. The tip of the positioning pin (4) and the entrance of the guide hole (5) are tapered to facilitate engagement.

As mentioned above, after the rotary table (1) is stopped at an approximate position by the signal from the position sensor (2), another quick-acting system is used to stop the rotary table (1).
) The positioning pin (4) is inserted into the guide hole (5) on the top (5) using a taper, and the position is corrected to improve the stopping accuracy.

(The main body (rotary table (1)) for the active positioning pin that the invention seeks to solve
A drive system including a motor separate from the drive of the rotary table (1) is required, and the positioning pin (4) is raised in response to a signal to stop the rotation of the rotary table (1), and rotated in response to a lowering signal for the positioning pin (4). The table (1) must be rotated, and a position detection sensor is required near the rotary table (1) and the positioning pin (4). This is particularly true when used in nuclear power-related fields (1), for example, in equipment where high-level waste assimilates are placed on a rotary table and rotated, or in equipment that is used near the assimilates (1).
05 to 1O'R/11), it is almost impossible to use normally commercially available limiter switches, photoelectric sensors, proximity sensors, etc.

In addition, even if the final positional accuracy is secured by inserting a positioning pin, the stopping position by the brake must be within a range that allows at least the engagement of the pin with the hole. ) and the position sensor (2) required fine relative position adjustment.

Therefore, the present invention (a) does not require a dedicated motor to drive positioning elements such as positioning pins, abutment stoppers, and clamp mechanisms, and (b) provides a stop that is easily susceptible to radiation damage near the driven body. To realize a positioning device that satisfies the following conditions: does not require the placement of a position sensor, does not require fine adjustment of the CC) stop position sensor or the dock that operates it, and can improve the stopping accuracy of a constant pitch drive system. This is the object of the present invention.

[Structure of the invention]

(Means for Solving the Problems) The positioning device of the present invention includes a Geneva gear device that intermittently displaces a driven body driven by a motor and connected to an output side at a constant pitch, and an input of the Geneva gear device. The structure includes a position correction and holding mechanism that is driven by a drive shaft connected to the shaft via a gear and that reproducibly holds the driven body in a predetermined position during the period when the driven body is stopped. .

(Function) In the positioning device of the present invention, when the input shaft of the Geneva gear device rotates one revolution by the motor, the output shaft also rotates one half only during the 1/N rotation period during which the input shaft and the output shaft mechanically engage. During the (1-1/N) rotation period of the input shaft, only the input shaft rotates, and the output shaft is kept in a stopped dz state. In other words, the driven body is displaced during the 1/N rotation period of the input shaft, (1=
l/N) The rotation period is stopped. The position correction and holding mechanism, in which the drive shaft is connected to the input shaft of the Geneva gear device via a gear, is configured so that the driven body stops within the (1-1/N) rotation period of the input shaft of the Geneva gear device, that is, after the driven body is displaced. During this period, the locking means is activated and engages with the stopped driven body to slightly correct the position of the driven body and hold it in a predetermined position.

(Example) Hereinafter, the present invention will be described in detail based on the example shown in the drawings.

A positioning device according to an embodiment of the present invention is shown in FIG.

In FIG. 1, the Geneva gear assembly fa (16) is of a type that uses a four-groove driven wheel, and the drive wheel (ltia) has its input shaft (16b) driven by a motor (18).

The driven wheel (16c) rotates intermittently at a rate of 174 rotations per rotation of the drive wheel (16a). A rotary table (11) is connected to the output shaft (16d) of the driven wheel (16c), and rotates intermittently by 174 revolutions for every revolution of the input shaft (16b) of the Geneva gear device (26). Rotary table (1
1) has four pin engagement holes (15) equally spaced in the circumferential direction.
is dawning.

In addition, an IH drive shaft (20) is connected to the input shaft (16b) of the Geneva gear device (16) via a bevel gear (17), and a cam (19) is attached and fixed to this quick drive shaft. has been done.

Furthermore, a positioning pin (12) is provided which is raised and lowered by this cam (19) and which engages with a pin engagement hole (15) of the rotary table (11) when raised. Furthermore, (13)
is a guide for the positioning pin (11), and (14) is a spring for retracting the positioning pin (11). The quick-acting shaft (20), cam (+9), positioning pin (1)
2), the spring (14), and the guy F (13) constitute a position correction holding mechanism.

The operation of the positioning device according to the present invention constructed as described above will be described below. When the input shaft (16b) of the riser gear device (16) rotates once by the motor (18), there is a mechanical engagement period of 1/4 rotation during which the driving wheel (16a) and the driven wheel (1 (ic)) engage. During the remaining 374 rotations, only the input shaft (16b) rotates and the output shaft (16d) remains stationary.In other words, the output shaft (16d) Directly connected rotary table (
11), the input shaft (16b) rotates 174 times during 174 rotations during one rotation, and is stopped during the remaining 3/4 rotation period.

The rotation of the input shaft (16b) of the Geneva gear device (16) is branched by a bevel gear (17), which is attached to the shaft (20).
A fixed cam (19) rotates once for every revolution of the input shaft (16b). The positioning pin (12) is connected to the cam (19
) rises and falls in response to the rotation of the The period during which the positioning pin (12) rises and is inserted into the pin engagement hole (+5) of the rotary table (11) is
), the timing of the cam (19) is adjusted so that the output shaft (16d) of the rotary table (11) is stopped, that is, the rotary table (11) is stopped, as shown in FIG. ) during the stop period of the locating pin (12)
is inserted into the pin engagement hole (15) and one rotation table (1
1) The stop position can be corrected with high precision and held at an accurate position.

Although not shown in Fig. 1, there is also a rotary table (
The signal for turning off the power of the motor (18) in order to keep the motor (11) stopped is obtained from the quick-acting shaft (20) connected to the input shaft (16b) via a bevel gear (17).
A dog is attached to the rotary table (11), and the position sensor is activated while the positioning pin (12) is inserted into the pin engagement hole (15) of the rotary table (11). Since the timing of transmitting this signal may be during the insertion period of the positioning pin (12), there is no need for any particular fine adjustment. Furthermore, the dog and position sensor can be mounted sufficiently far away from the rotary table (11), and if necessary, the effects of radiation can be cut using a shield such as a button. Suitable for use in the nuclear field.

As described above, the positioning device according to one embodiment of the present invention includes (a
) Since the power is branched from the input shaft (16b) of the Geneva gear device (16) to drive the position correction and holding mechanism, a dedicated motor for positioning is not required and the device is simplified; (b)
By using the Geneva gear system 1ff (16),
The output shaft (16b) is stopped mechanically.

The timing at which the motor (18) is stopped in order to continue the stopped state of the rotary table (11) is determined by the positioning pin (
12) during the insertion period, and there is no need for fine adjustment of the mounting position of this stop signal dog and position sensor. Since it is only necessary to detect the movement of the connected quick-acting shaft (20), it is possible to place it away from the rotary table (11) which is the driven object, and the high-level waste assimilation body is rotated by the rotary table. When used in the nuclear field, it is easy to prevent damage caused by radiation.
It has the following effects.

〔Effect of the invention〕

As detailed above, according to the present invention, there is provided a Geneva gear device which intermittently displaces a driven body driven by a motor and connected to the output side at a constant pitch, and a gear on the input shaft of the Geneva gear device. A positioning device is provided with a position correction holding tank that is driven by a quick-acting shaft connected through the drive shaft and reproducibly holds the driven body in a predetermined position during the period when the driven body is stopped. The power is branched from the input shaft of the Geneva gear device to drive the position correction and holding mechanism, which simplifies the device by eliminating the need for a dedicated positioning motor.The output shaft of the Geneva gear device instantly moves the driven object. The stop of the motor is performed mechanically, and the timing to stop the motor in order to continue the stopped state of the driven body may be during the operation period of the position correction holding mechanism. does not require fine adjustment of the mounting position, and since the position sensor only needs to detect the movement of the quick-acting shaft connected to the input shaft of the Geneva gear device via a gear, it can be placed away from the driven body. Even when used in the nuclear field, it is possible to obtain the first-class effect of easily preventing damage caused by radiation.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a perspective view showing a positioning device according to an embodiment of the present invention;
Figure 2 shows a time chart 1 of the operation of each part of the device in Figure 1.
1. FIG. 3 is a perspective view showing a conventional positioning device. 11... Rotating table, 12... Positioning pin, 1
5... Pin engagement hole, 16... Geneva gear device, 16a... Oscillating wheel. 16c...driven wheel, 17...bevel gear, 19...cam,

Claims (1)

[Claims] A Geneva gear device which is driven by a motor and which intermittently displaces a driven body connected to the output side at a constant pitch, and a drive shaft which is connected to the input shaft of this Geneva gear device via a gear and driven by A positioning position comprising a position correction and holding mechanism that reproducibly restrains the driven body in a predetermined position during a period when the driving body is stopped.