JP3548738B2 - Rotary actuator with intermediate stop mechanism - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rotary actuator with an intermediate stop mechanism driven by a fluid pressure, which can stop the oscillation of an output shaft in an intermediate manner with a simple configuration, thereby enabling three or four stops.
[0002]
[Prior art]
There are many demands for intermediate stopping of a fluid pressure driven rotary actuator.However, since a piston or the like is driven by fluid pressure, it is necessary to intermediately stop the piston by some means. Is complicated. In order to cope with such a problem, the present inventor has previously proposed a rotary actuator with an intermediate stop mechanism as Japanese Patent Application No. 2000-106468. A structure that can be driven by pressure is required.
[0003]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION The present invention has been made to satisfy such a demand, and the technical problem thereof is to basically provide a simple and compact structure capable of intermediately stopping the swing of the output shaft, thereby achieving three points. Another object of the present invention is to provide a rotary actuator with an intermediate stop mechanism driven by fluid pressure, which can stop at four points.
Another technical object of the present invention is to provide a fluid-driven rotary actuator with an intermediate stop mechanism which can realize swinging and intermediate stop of an output shaft by supplying and discharging fluid of a single pressure. .
[0004]
[Means for Solving the Problems]
A rotary actuator with an intermediate stop mechanism according to the present invention for solving the above-mentioned problems has a pair of cylinders arranged in parallel in a main body, and a pair of main pistons sliding in the cylinders provided with racks, respectively. In a rotary actuator, the rack is meshed with a pinion disposed between a pair of cylinders, and the main piston is driven by the supply and discharge of the pressurized fluid to output a swing rotation from an output shaft of the pinion. The end is a supply / discharge port, and the inner end of a ventilation pipe extending through the main piston from one end of each of the pair of cylinders is opened to a pressure chamber on the side of the cylinder through the main piston. The open end of at least one of the cylinders to the pressure chamber of the ventilation pipe, as a stopper for setting an intermediate stop position, An auxiliary piston is slidably fitted in the pressure chamber, and a supply / discharge port for intermediate stop is opened in the auxiliary pressure chamber partitioned by the auxiliary piston on the side opposite to the main piston. .
[0005]
In the rotary actuator having the above configuration, in a state where the pressure fluid is not supplied to the sub-pressure chamber, the pressure fluid is supplied from the supply / discharge port to one pressure chamber of the pair of main pistons through the ventilation pipe, and the pressure of the other main piston is reduced. When the chamber is opened to the atmosphere, the main pistons are driven in opposite directions to each other, and the pinions meshing with the racks provided on the pair of main pistons are driven to rotate, and the rotation is taken out from the output shaft. Conversely, when a pressure fluid is supplied to the pressure chamber that has been opened to the atmosphere and the pressure chamber that has been supplying the pressure fluid is opened to the atmosphere, the pair of main pistons are driven in opposite directions, and the pinion is turned on. It will rotate in reverse. The two rotational positions in these cases correspond to the stroke ends of the respective main pistons.
[0006]
Also, when the pressure fluid is supplied to the pressure chamber in the other cylinder while the pressure fluid is supplied to the sub-pressure chamber in one cylinder, the sub-piston moves to the stopper at the tip of the vent pipe by the fluid pressure in the sub-pressure chamber. The main piston is driven by the pressure of the fluid supplied to the pressure chamber. On the other hand, the fluid pressure acting area of the main piston in the pressure chamber is smaller than the fluid pressure acting area with respect to the sub piston by the sectional integral of the ventilation pipe. The main piston moves to a position where the main piston comes into contact with the sub-piston, and as a result, both main pistons stop at an intermediate position determined by the position of the stopper, so that the output shaft of the pinion can be intermediately stopped.
[0007]
In the rotary actuator, a flow path for synchronously supplying and discharging the pressure fluid is provided at opposite ends of the pair of main pistons, and acts on the sub-piston by feeding the pressure fluid to the sub-pressure chamber. An augmenting means for increasing the driving force can be provided, whereby the fluid pressure for driving can be applied to the pair of main pistons, and the driving force can be increased. As the augmenting means, it is preferable that an auxiliary piston is mechanically connected to the auxiliary piston and an auxiliary pressure chamber for applying a fluid pressure to the auxiliary piston is formed in communication with the auxiliary pressure chamber. Can supply the pressure fluid supplied to the pressure chamber of the main piston as it is to the sub-pressure chamber and the auxiliary pressure chamber as it is.
[0008]
In the rotary actuator, the positions of the open ends of the ventilation pipes in the pair of cylinders to the pressure chambers are changed, and each of the open ends is used as a stopper for setting an intermediate stop position. The auxiliary shaft is slidably inserted into the shaft, and the supply shaft for the intermediate stop is opened in each of the sub-pressure chambers defined on the side opposite to the main piston by both sub-pistons, thereby causing the output shaft to swing. Can be stopped at two intermediate stop positions determined by the respective stopper portions of the pair of ventilation pipes and at four points at both ends determined by the stroke ends of the main piston.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
1 to 4 show different operation states of the first embodiment of the rotary actuator with an intermediate stop mechanism according to the present invention.
The rotary actuator according to the first embodiment includes a pair of cylinders 2A and 2B arranged in parallel in a main body 1, and both ends of the cylinders 2A and 2B are closed by end covers 3 and 4 fixed to the main body 1. In the cylinders 2A and 2B, main pistons 6A and 6B are air-tightly and slidably fitted by seal members provided at both ends thereof, respectively. Are provided with racks 7A and 7B, respectively.
[0010]
On the other hand, in the main body 1, an opening 11 is provided in which a wall between the pair of cylinders 2A and 2B is removed, and the opening 11 meshes with the racks 7A and 7B of the pair of main pistons 6A and 6B. The pinion 12 is rotatably supported. Although not shown, the output shaft of the pinion 12 protrudes from the main body 1 to the outside, and when the main pistons 6A and 6B are driven by supplying and discharging fluid pressure described later into the cylinder, necessary swings are generated. The dynamic rotational movement is output to the outside.
[0011]
The end cover 3 at one end of the main body 1 is provided with ventilation pipes 15A, 15B extending into the respective cylinders 2A, 2B with outer ends serving as pressure fluid supply / discharge ports 16A, 16B, and the ventilation pipes 15A, 15B. Is penetrated through the main pistons 6A and 6B, and the inner ends thereof are opened to the pressure chambers 17A and 17B on the side penetrating the main pistons.
[0012]
On the end cover 4 side of the main pistons 6A, 6B in the pair of cylinders 2A, 2B, the open ends of the ventilation pipes 15A, 15B to the pressure chambers 17A, 17B are set to the intermediate stop positions of the main pistons 6A, 6B. Sub-pistons 19A and 19B, which are essential parts of the intermediate stop mechanism, are slidably fitted into the pressure chambers 17A and 17B as stoppers 18A and 18B for setting. In order to separately supply and discharge the pressure fluid to the sub-pressure chambers 20A and 20B defined on the side opposite to the end covers 4A and 6B (end cover 4 side), the end cover 4 is provided with intermediate supply and discharge ports 21A and 21B. Has been established. The auxiliary pistons 19A and 19B are airtightly slidable in the cylinders 2A and 2B via seal members, like the main pistons 6A and 6B.
[0013]
In the first embodiment, the auxiliary pistons 19A and 19B are fitted into both of the pair of cylinders 2A and 2B. However, the auxiliary piston can be fitted into only one of the cylinders 2A and 2B.
In the drawing, reference numerals 24A and 24B denote breathing chambers formed on the end cover 3 side of the main pistons 6A and 6B, and reference numerals 25A and 25B denote positions for setting stroke ends of the auxiliary pistons 19A and 19B on the end cover 4 side. The adjustable stoppers 26A and 26B represent small holes that allow the inside of the ventilation pipes to communicate with the pressure chambers 17 and 17B even when the auxiliary pistons 19A and 19B are in contact with the tips of the ventilation pipes 15A and 15B. .
[0014]
In the rotary actuator having the above configuration, as shown in FIG. 1, in a state where the pressure fluid is not supplied to the sub-pressure chambers 20A and 20B, the pressure fluid (compressed air) is supplied from the supply / discharge port 16B to the pressure chamber 17B through the ventilation pipe 15B. When the other pressure chamber 17A is opened to the atmosphere through the supply / discharge port 16A, the main piston 6B is driven by the fluid pressure acting on the annular pressure receiving surface facing the pressure chamber 17B, and the rack in the main piston 6B is driven. 7B, the main piston 6A is driven in the opposite direction via the pinion 12 and the rack 7A of the other main piston 6A, the main piston 6A moves to a position where it comes into contact with the sub piston 19A, and stops. Twelve revolutions are taken from the output shaft.
[0015]
Contrary to the above, when the pressure fluid is supplied to the pressure chamber 17A opened to the atmosphere through the supply / discharge port 16A and the pressure chamber 17B supplied to the pressure fluid is opened to the atmosphere through the supply / discharge port 16B, as shown in FIG. As shown in FIG. 4, the pair of main pistons 6A and 6B are driven in directions opposite to those in FIG. 1, and the pinion 12 rotates in the reverse direction.
1 and 4 correspond to the stroke ends of the respective main pistons 6A and 6B.
[0016]
Further, as shown in FIG. 2, when the pressure fluid is supplied to the pressure chamber 17B of the other cylinder 2B while the pressure fluid is supplied to the sub-pressure chamber 20A of one cylinder 2A from the supply / discharge port 21A for intermediate stop. The auxiliary piston 19A abuts the stopper 18A at the tip of the vent pipe 15A due to the fluid pressure in the auxiliary pressure chamber 20A, while the main piston 6B is driven by the pressure of the fluid supplied to the pressure chamber 17B. Since the fluid pressure acting area of the main piston 6B at 17B is smaller than the fluid pressure acting area of the sub piston 20A in the sub-pressure chamber 20A by the sectional integral of the ventilation pipe 15B, the main piston 6B is driven through the pinion 12 through the pinion 12. As a result, the main piston 6A moves to a position where it comes into contact with the auxiliary piston 20A, and as a result, the position of the stopper portion 18A increases. Both main piston 6A in the middle position of the determined Figure 2, 6B is stopped, therefore, it can be an intermediate stop the output shaft of the pinion 12 at that position.
[0017]
FIG. 3 shows a state where the pressure fluid is supplied from the supply / discharge port 21B to the sub-pressure chamber 20B in one cylinder 2B and the pressure fluid is supplied to the pressure chamber 17A in the other cylinder 2A, contrary to the case of FIG. In this case, the positions of the two main pistons 6A and 6B are substantially the same as those in FIG. 2, so that the rotational position of the output shaft of the pinion 12 is also the same. Therefore, even if the sub-piston is inserted into only one of the pair of cylinders 2A and 2B, the intermediate stop position can be secured by the operation state shown in FIG. 2 or FIG.
As described above, according to the rotary actuator of the first embodiment, the output shaft can be stopped at three positions including one intermediate stop position.
[0018]
The second embodiment shown in FIG. 5 differs from the first embodiment in the intermediate stop position in FIGS. 2 and 3, and as a result, the output shaft is moved to the intermediate two positions and the stroke ends of the main pistons 6A and 6B. It is designed to be able to stop at a total of four positions of two positions. For such a four-position stop, in the second embodiment, the length of the ventilation pipes 27A, 27B corresponding to the ventilation pipes 15A, 15B of the first embodiment is changed, and accordingly, the stopper at the tip of the ventilation pipe is changed. The positions of the portions 28A and 28B are different. In the second embodiment, the intermediate stop position can be changed only by changing the attachment position of the ventilation pipes 27A, 27B to the end cover 3 by the screws 29A, 29B and the like.
[0019]
Other configurations and operations of the rotary actuator of the second embodiment are the same as those of the first embodiment except that the stop position of the output shaft corresponding to FIGS. 2 and 3 is different. The same reference numerals as in the first embodiment denote the same parts, and a description thereof will be omitted.
[0020]
In the rotary actuators of the first and second embodiments described above, the rotational driving force of the output shaft depends on the fluid pressure acting on only one of the main pistons 6A, 6B. On the other hand, in the third embodiment shown in FIGS. 6 to 9, the rotational driving force of the output shaft is obtained by the fluid pressure acting on both of the pair of main pistons. Further, with the increase in the driving force of the main piston, it is necessary to increase the force for pressing the sub piston against the stopper. Therefore, an augmenting means for increasing the driving force acting on the sub piston is provided. I have.
[0021]
The configuration and operation of the rotary actuator according to the third embodiment will be described focusing on differences from the first embodiment. First, one ends of a pair of cylinders 32A and 32B arranged in parallel in the main body 31 are connected to the first end. Although it is closed by the same end cover 33 as in the first embodiment, flow paths in ventilation pipes 45A and 45B having supply and discharge ports 46A and 46B of the pressurized fluid at the outer ends are branched in the end cover 33. Specifically, as can be seen from FIGS. 6, 8, and 9, the vent pipe 45A inserted into one cylinder 32A penetrates through the main piston 36A and has a pressure at the tip similarly to the first embodiment. At the same time as having a flow path for opening into the chamber 47A, a flow path 61A for flowing out from the ventilation pipe 45A to the periphery is formed in the end cover 33, and a flow path 6 formed in the end cover 33 is further formed. A, through 63A, and communicates with the pressure chamber 54B between the main piston 36B and the end cover 33 in the other cylinder 32B.
[0022]
Therefore, when the pressure fluid is supplied from the supply / discharge port 46A, the pressure fluid is introduced into the pressure chamber 47A through the ventilation pipe 45A penetrating through the main piston 36A, and at the same time, the flow paths 61A, 62A branched in the end cover 33. , 63A into the pressure chamber 54B of the other cylinder 32B, whereby the pressurized fluid is supplied synchronously to the two pressure chambers 47A, 54B at the opposite ends of the pistons 36A, 36B, so that the respective main piston 36A , 36B, a larger rotational driving force is applied to the output shaft 65 connected to the pinion 42 than in the first embodiment.
[0023]
On the other hand, the ventilation pipe 45B inserted into the cylinder 32B has a flow path that penetrates through the main piston 36B and opens the distal end to the pressure chamber 47B, and at the same time, flows out from the ventilation pipe 45B inside the end cover 33. A flow path 61B is formed, and further communicates with a pressure chamber 54A between the main piston 36A and the end cover 33 in the other cylinder 32A through flow paths 62B and 63B formed in the end cover 33.
Therefore, when the pressure fluid is supplied from the supply / discharge port 46B while the pressure fluid is discharged from the supply / discharge port 46A, the pressure fluid is introduced into the pressure chamber 47B through the ventilation pipe 45B, and at the same time, the branched flow path 61B , 62B, 63B, is also introduced into the pressure chamber 54A of the cylinder 32A, and a large rotational driving force is applied to the output shaft 65 by the fluid pressure acting on the respective main pistons 36B, 36A in the two pressure chambers 47B, 54A.
[0024]
As in the first embodiment, the pinion 42 meshing with the racks 37A and 37B of the pair of main pistons 36A and 36B is provided in the opening between the pair of cylinders 32A and 32B. The output shaft 65 of the pinion 42 is protruded outward from the main body 31 and connected to a table 66 rotatably supported on the main body 31 as shown in FIG. It can transmit an oscillating rotational movement.
Although the table structure is not shown in the first and second embodiments, it is substantially the same as that shown in FIG.
[0025]
On the end cover 34 side of the main pistons 36A, 36B in the pair of cylinders 32A, 32B, open ends of the ventilation pipes 45A, 45B to the pressure chambers 47A, 47B are set, and intermediate stop positions of the main pistons 36A, 36B are set. The auxiliary pistons 49A, 49B are slidably fitted into the pressure chambers 47A, 47B to define the auxiliary pressure chambers 50A, 50B, and the shafts provided in the auxiliary pistons 49A, 49B. 70A, 70B are formed in the end cover 34 from the sub-pressure chambers 50A, 50B in an airtight manner through bearing walls 71A, 71B provided between the end portions of the cylinders 32A, 32B and the end cover 34. The auxiliary pistons are introduced into the auxiliary pressure chambers 72A, 72B, and the auxiliary pistons 73A, 73B are attached to the ends of the shafts 70A, 70B, so that the auxiliary Emissions 49A, 49B and the auxiliary piston 73A, is mechanically linked to 73B.
[0026]
Further, the end cover 34 is used to apply fluid pressure to the auxiliary pistons 49A, 49B and the auxiliary pistons 73A, 73B to press the auxiliary pistons 49A, 49B against stoppers 48A, 48B at the ends of the ventilation pipes 45A, 45B. Are provided with supply / discharge ports 74A and 74B for the intermediate stop pressure fluid, which open to the auxiliary pressure chambers 72A and 72B. The auxiliary pressure chambers 72A, 72B are communicated with the auxiliary pressure chambers 50A, 50B by communication paths 75A, 75B provided inside the shafts 70A, 70B of the auxiliary pistons 49A, 49B. When the pressurized fluid is supplied from the discharge port 74A or 74B, the pressurized fluid is supplied to both the auxiliary pressure chambers 72A and 72B and the auxiliary pressure chambers 50A and 50B, and is supplied to the auxiliary pistons 73A and 73B and the auxiliary pistons 49A and 49B. The sub-pistons 49A, 49B are pressed against the stoppers 48A, 48B with the increased driving force.
[0027]
In the third embodiment, as described above, the driving force of the output shaft is increased so that the rotational driving force of the output shaft 65 can be obtained by the fluid pressure acting on both the pair of main pistons 36A and 36B. However, when such an enhancement is performed, it becomes necessary to increase the force of pressing the sub pistons 49A, 49B against the stoppers 48A, 48B as compared with the first embodiment.
However, in the third embodiment, the auxiliary pistons 73A and 73B are mechanically connected to the auxiliary pistons 49A and 49B, and the auxiliary pistons are provided with an augmenting means for simultaneously applying fluid pressure to both pistons. In addition, the output shaft can be stably stopped intermediately.
In the third embodiment, as in the second embodiment, the output shafts can be stopped at two intermediate positions by providing a difference between the lengths of the ventilation pipes 45A and 45B.
[0028]
【The invention's effect】
According to the rotary actuator with the intermediate stop mechanism of the present invention described in detail above, the swing of the output shaft can be intermediately stopped with a simple and compact configuration, thereby enabling three or four points of stop. Further, the swinging and the intermediate stop of the output shaft can be realized by supplying and discharging the fluid having a single pressure.
[Brief description of the drawings]
FIG. 1 is a plan sectional view showing a first embodiment of a rotary actuator with an intermediate stop mechanism according to the present invention.
FIG. 2 is a plan sectional view showing another operation state of the first embodiment.
FIG. 3 is a plan sectional view showing still another operation state of the first embodiment.
FIG. 4 is a plan sectional view showing still another operation state of the first embodiment.
FIG. 5 is a plan sectional view showing a second embodiment of the rotary actuator with an intermediate stop mechanism according to the present invention.
FIG. 6 is a plan sectional view (a half section of a sub piston and an auxiliary piston) showing a third embodiment of the rotary actuator with an intermediate stop mechanism according to the present invention.
FIG. 7 is a sectional view taken along line AA in the third embodiment of FIG. 6;
FIG. 8 is a side view of the third embodiment.
FIG. 9 is a sectional view of a main part of the third embodiment.
[Explanation of symbols]
1, 31 Main body 2A, 2B, 32A, 32B Cylinder 3, 4, 33, 34 End cover 6A, 6B, 36A, 36B Main piston 7A, 7B, 37A, 37B Rack 12, 42 Pinion 15A, 15B, 27A, 27B , 45A, 45B Vent pipes 17A, 17B, 47A, 47B Pressure chambers 18A, 18B, 28A, 28B, 48A, 48B Stoppers 19A, 19B, 49A, 49B Sub pistons 20A, 20B, 50A, 50B Sub pressure chambers 21A, 21B , 74A, 74B Supply / discharge ports 61A-63A, 61B-63B Flow paths 72A, 72B Auxiliary pressure chambers 73A, 73B Auxiliary piston

Claims (4)

A pair of cylinders are arranged in parallel in the main body, a rack is provided on each of a pair of main pistons sliding in the cylinders, and these racks are meshed with a pinion disposed between the pair of cylinders. In a rotary actuator, a piston is driven by supply and discharge of a pressurized fluid to output a swing rotation from an output shaft of the pinion.
The outer end is a supply / discharge port, and the inner end of a ventilation pipe extending through the main piston from one end of each of the pair of cylinders is opened to a pressure chamber on the side of the cylinder through the main piston,
An opening end of at least one of the pair of cylinders to the pressure chamber of the ventilation pipe is slidably fitted into the pressure chamber as a stopper for setting an intermediate stop position. An intermediate stop supply / discharge port has been opened in the sub-pressure chamber defined on the side opposite to the main piston,
A rotary actuator with an intermediate stop mechanism. The rotary actuator with an intermediate stop mechanism according to claim 1,
At the opposite ends of the pair of main pistons, a flow path for synchronously supplying and discharging the pressure fluid is provided,
The auxiliary piston is provided with an augmenting means for increasing the driving force acting on the auxiliary piston by feeding the pressure fluid to the auxiliary pressure chamber,
A rotary actuator with an intermediate stop mechanism. The rotary actuator with an intermediate stop mechanism according to claim 2,
An augmenting means attached to the auxiliary piston, wherein an auxiliary piston is mechanically connected to the auxiliary piston, and an auxiliary pressure chamber for applying fluid pressure to the auxiliary piston is formed in communication with the auxiliary pressure chamber;
A rotary actuator with an intermediate stop mechanism. The positions of the open ends of the vent pipes to the pressure chambers in the pair of cylinders are changed, and each of those open ends is slidably movable as a stopper for setting an intermediate stop position. Inset,
An intermediate stop supply / discharge port has been opened in each of the two sub-pressure chambers, which are separated from the main piston by the two sub-pistons,
The rotary actuator with an intermediate stop mechanism according to any one of claims 1 to 3, wherein:

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