JPH05321912A - Double piston type torque actuator - Google Patents

Abstract

PURPOSE:To improve mechanical efficiency by providing long guide holes parallel with the axial direction of the cylinder in which piston arm driving pins are fitted on the guide member fixed to the cylinder between the pistons on both sides of a driven rotary shaft. CONSTITUTION:While a torque actuator is activated, with respect to a side(s) in slots 32, 33 for driven arms 26a, 26b inclining against the axial center direction of a cylinder, driving pins 30, 31 move in the axial center direction of the cylinder to press, and thereby lateral component of force acts at the positions of the drive pins 30, 31 toward a side of a driven rotary shaft 21. This component of force, however, is received by long guide holes 24 and 25 through rollers 34 and 35 at the positions of the piston arm driving pins 30 and 31, whereby moment is not generated in piston arms 28a, 28b, 29a, and 29b. Since the piston arm driving pins 30 and 31 are fitted in the long guide holes 24 and 25 parallel to the axial direction of the cylinder through the rollers 34 and 35, there is no fear that pistons 28 and 29 are inclined. Therefore, the impulses resistance can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double piston type torque actuator used as a driving means for a butterfly valve or the like, and more particularly to a scuff choke type tokule actuator.

[0002]

2. Description of the Related Art A double piston type torque actuator called a scout choke type is shown in FIG.
As shown in FIG. 10, separately movable pistons 2 and 3 are arranged on both sides of the driven rotary shaft 1, and piston arms parallel to each other sandwiching the driven rotary shaft 1 from both pistons 2 and 3. The piston arms 2a and 3a are connected to each other, and the piston arms 2 are attached to both ends of a driven arm 4 whose center portion is fixed to the driven rotating shaft 1 and which extends to both sides in the diametrical direction.
Driven elongated holes 7 and 8 into which driving pins 5 and 6 projecting from a and 3a are fitted are provided. 9 is a cylinder,
Reference numeral 10 is a piston advance limit stopper bolt, 11 is a piston retreat limit stopper bolt, 12 is a supply / exhaust passage communicating with the piston inner cylinder chamber 13, and 14 is a supply / exhaust passage communicating with a pair of piston outer cylinder chambers 15A, 15B. Is.

In this torque actuator, as shown in FIG. 9, a direction in which both pistons 2 and 3 are separated from each other by supplying pressurized air to the piston inner cylinder chamber 13 from a state where both pistons 2 and 3 are in the retracted limit position. When the piston arm 2a, 3a is moved forward, the driving pins 5, 6 pull the opposite ends of the driven arm 4 in opposite directions through the driven elongated holes 7, 8 to move the driven rotary shaft 1 clockwise. It will be driven to rotate. When the driven rotary shaft 1 rotates about 90 degrees, the pistons 2 and 3 reach the advance limit position as shown in FIG. 10, and one piston 3 comes into contact with the piston advance limit stopper bolt 10 and stops. From the state concerned
When pressurized air is supplied to the piston outer cylinder chambers 15A and 15B to move both pistons 2 and 3 back and forth in a direction in which they approach each other, the driving pins 5 and 6 of the respective piston arms 2a and 3a move into the driven long holes 7 , 8 are used to press both ends of the driven arm 4 in opposite directions to drive the driven rotary shaft 1 to rotate counterclockwise. When the driven rotary shaft 1 rotates about 90 degrees, the pistons 2 and 3 reach the retreat limit position as shown in FIG. 9, and one piston 2 comes into contact with the piston retreat limit stopper bolt 11 and stops. ..

As described above, in the double piston type torque actuator for rotating the driven rotary shaft 1 forward and backward in the range of about 90 degrees by the reciprocating movement of the pistons 2 and 3, FIG.
When the pistons 2 and 3 in the retract limit position move forward in the direction of separating from each other, as shown in FIG. 10, or in the direction of the approach of the pistons 2 and 3 in the advance limit position as shown in FIG. When moving in and out, in the first half of the moving stroke until the driven arm 4 takes a vertical posture with respect to the cylinder axis, the driven arm 4 with respect to the oblique side surfaces of the driven elongated holes 7 and 8 of the driven arm 4 is loaded. By the pressing action of the drive pins 5 and 6, a component force F to the side where the driven rotary shaft 1 is present acts on the positions of the drive pins 5 and 6 of the piston arms 2a and 3a. Of course, the component force F decreases as the driven arm 4 rotates, and when the driven arm 4 is oriented perpendicular to the cylinder axis, the component force F becomes zero. In the latter half of the movement stroke of tilting from the posture perpendicular to the axial direction to the opposite direction, the acting direction of the component force F is opposite (outward).

In the conventional torque actuator of this type, the inner side surfaces of the piston arms 2a and 3a are brought into contact with the peripheral surface of the driven rotary shaft 1, and the driven rotary shaft 1 receives the inward component force F shown in the drawing. In addition, the outer surfaces of the free ends of the piston arms 2a and 3a are brought into contact with the inner surface of the cylinder 9 so that the cylinder 9 receives the outward component force. 2a, 3a)
Since it is configured so as to prevent the tilting of the piston arm 2, the contact point P between the piston arms 2a and 3a and the driven rotary shaft 1 will be described, for example, in the case where the component force F acts inward as shown in the figure. When the positions of the driving pins 5 and 6 which are the acting positions of the component force F are separated from each other in the cylinder axial direction,
That is, when the pistons 2 and 3 start moving from the retreat limit position or the advance limit position where the component force F becomes maximum, the component force F
As a result, a large moment acting on the contact point P with the driven rotary shaft 1 as a fulcrum acts on the piston arms 2a, 3a, and this moment acts between the pistons 2, 3 and the cylinder 10 in a laterally large pressing force f. Is generated, and this extremely large lateral pressing force f is applied to the piston 2,
The sliding friction of No. 3 was remarkably increased, and the mechanical efficiency of this torque actuator was significantly reduced.

Further, as shown in FIG. 10, even when the pistons 2 and 3 at the advance limit position start to move in and out, the component force F acting on the piston arms 2a and 3a is applied to the driven rotary shaft 1.
In order to allow the pistons 2 and 3 to be received, the inner side surfaces of the piston arms 2a and 3a must be in contact with the driven rotary shaft 1 even when the pistons 2 and 3 are at the advance limit position. Therefore, as shown in the drawing, the piston arms 2a and 3a need to extend rearward longer than the mounting positions of the drive pins 5 and 6, and the lengths that are originally long enough to mount the drive pins 5 and 6 are necessary. What is sufficient is that the piston arms 2a and 3a must be made longer by the length L as shown in the figure. Therefore, as shown in FIG. 9, the distance between the pistons 2 and 3 at the retracted limit position becomes long, and the cylinder length for obtaining the necessary piston stroke becomes long, so that the overall size of the actuator is reduced. Was difficult.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and its features will be shown by the reference numerals of the embodiments described later. The double-piston type torque actuator of the present invention comprises pistons 28, 2 which are movable on both sides of a driven rotary shaft 21 separately.
9 are provided, and the driven rotary shaft 21 is
Piston arms (28a, 2
8b) (29a, 29b) are arranged in a row, and a driven arm (2) extending from the driven rotary shaft 21 to both sides in the diametrical direction.
6a, 26b) at both ends thereof, the driven elongated holes 3 into which the driving pins 30, 31 projectingly provided on the respective piston arms are fitted.
In a double-piston type torque actuator having two pistons 2 and 33, a guide member 22 is fixedly mounted inside the cylinder 20 between the pistons 28 and 29, and the guide member 22 has a driving pin for both piston arms. 30, 3
1 is provided with elongated guide holes 24 and 25 which are parallel to the cylinder axis direction.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings, but in this embodiment, the parts corresponding to the stopper bolts 11 and 12 described in FIG. 9 are omitted. .. 1 to 3, reference numeral 20 denotes a cylinder, and a driven rotary shaft 21 is supported in a state of penetrating the center portion thereof in a transverse manner. A drive shaft of a butterfly valve or the like is connected to the one-end square hole portion 21a of the driven rotation shaft 21.

Reference numeral 22 is a guide member consisting of a single plate member, which is fitted and fixed in the diametrical direction at the central portion of the cylinder 20, and as shown in FIGS. 3A and 3B, the driven rotary shaft 2 is provided at the central portion.
1 has a hole 23 penetrating therethrough, and elongated guide holes 24, 25 parallel to the cylinder axis direction are provided on both upper and lower sides. Driven arms 26a, 2 that sandwich the guide member 22 and extend to both sides in the diametrical direction are mounted on the driven rotary shaft 21.
6b is attached via the key 27.

Numerals 28 and 29 are a pair of pistons, which are fitted in the cylinder 20 so as to be separately movable on both sides of the driven rotary shaft 21 (guide member 22), and one piston 28
From the left, a pair of left and right piston arms 28a, 28b sandwiching one end of the driven arms 26a, 26b from both left and right sides.
A pair of left and right piston arms 29a and 29b sandwiching the other ends of the driven arms 26a and 26b from the left and right sides are continuously provided from the other piston 29. These piston arms 28a and 28b and the piston arm 2
9a and 29b are extended in the cylinder axis direction between the driven rotary shaft 21 and the cylinder 20 so as to sandwich the driven rotary shaft 21 from above and below, but these piston arms 28a to 29b are driven by the driven shafts. As shown in FIG. 1B, the driven arm 26 a, the driven arm 26 a,
It is configured so that it does not come into contact with the boss portion that projects to the left and right of 26b.

Reference numeral 30 denotes the piston arms 28a and 28b.
Is a drive pin erected between the tip portions of the piston arms, and 31 is a drive pin erected between the tip portions of the piston arms 29a and 29b. Driven long holes 32, 33 are formed in the both ends of the driven arms 26a, 26b along the diametrical direction of the driven rotary shaft 21 so as to be cut out from both ends, and drive pins on the piston arms 28a, 28b side are formed. 30 is
One driven long hole 32 and one guiding long hole 2 of the guide member 22.
5 and the driving pin 31 on the side of the piston arms 29a, 29b penetrates the other driven elongated hole 33 and the guiding elongated hole 24 of the guide member 22. A roller having a slightly smaller outer diameter than the width of the long holes 24, 25 (a needle bearing or the like can be used) 3 is provided in a portion of each of the drive pins 30, 31 penetrating the long guide holes 24, 25.
4,35 are supported.

Reference numeral 36 is a supply / exhaust passage communicating with a cylinder chamber 37 between the pistons 28, 29, and 38 is a supply / exhaust passage communicating with outer cylinder chambers 39A, 39B of the pistons 28, 29. The peripheral wall and the end plate of 20 are perforated.

The torque actuator constructed as described above supplies pressurized air to the cylinder chamber 37 with both pistons 28 and 29 in the retracted position as shown in FIG. When the pistons 28, 29 are moved forward in the direction of separating from each other, the driving pins 30, 31 of the respective piston arms 28a, 28b and 29a, 29b are moved through the driven slots 32, 33 to move the driven arms. Pull both ends of 26a, 26b in opposite directions,
As shown in FIG. 2, the driven arms 26a and 26b are rotated clockwise by approximately 90 degrees. On the contrary, Fig. 2
When both pistons 28 and 29 are in the advance limit position as shown in FIG. 2, when compressed air is supplied to both cylinder chambers 39A and 39B to move both pistons 28 and 29 back and forth in a direction in which they approach each other, The driving pins 30 and 31 of the piston arms 28a and 28b and 29a and 29b press the opposite ends of the driven arms 26a and 26b in opposite directions through the driven elongated holes 32 and 33, as shown in FIG. 1A. The driven arms 26a and 26b are rotated counterclockwise by approximately 90 degrees. The forward and reverse rotations of the driven arms 26a and 26b are transmitted to the driven rotary shaft 21, and the driven rotary shaft 2
A butterfly valve or the like, which is linked to 1, is opened and closed.

Even when the above torque actuator is operated, the driving pins 30, 31 are attached to the side surfaces of the driven slots 32, 33 of the driven arms 26a, 26b inclined with respect to the cylinder axis direction. Moves and pushes in the axial direction of the cylinder, resulting in piston arms 28a, 28b and 2
At the positions of the driving pins 30 and 31 of 9a and 29b, a lateral component force to the side where the driven rotary shaft 21 is present acts. However, this lateral component force is received by the side surfaces of the elongated guide holes 24, 25 of the guide member 22 via the rollers 34, 35 at the positions of the drive pins 30, 31 which are the generation positions thereof. These piston arms 28a, 28b
And 29a and 29b do not generate a moment. Of course, both the pistons 28 and 29 are provided with the drive pins 30 and the guide elongated holes 24 and 25 parallel to the cylinder axis direction.
Since 31 is fitted through the rollers 34 and 35, only linear movement in the cylinder axis direction is possible and there is no risk of tilting.

As shown in FIG. 1B, the drive pins 30 and 31 are fitted with stop rings 36 in the circumferential grooves formed at both ends thereof, and the stop pins 36 are pulled out from the piston arms 28a, 28b and 29a, 29b. However, in this method, the driving pin 30 is prevented so that both ends of the driving pin 30, 31 projecting from the piston arms 28a, 28b and 29a, 29b and the stop ring 36 do not contact the cylinder 20. , 31 closer to the cylinder axis, and the piston arms 28a-29b, the guide member 22, the driven arms 26a, 26b, and the like are made thinner, which is unfavorable.

In order to solve such a problem, for example, as shown in FIGS. 4 and 5, drive pins 30 and 31 are provided.
Has a total length equal to the distance between the outer surfaces of the pair of left and right piston arms 28a, 28b and 29a, 29b, and has a length substantially equal to the thickness of the piston arms 28a-29b at both ends of the drive pin 30, 31. The small-diameter shaft portion 40 is formed, and the piston arms 28a, 28b and 29a, 29b are formed with pin holes 41 having an inner diameter through which the driving pins 30, 31 can be inserted, and press-fitted and fixed in the pin holes 41. A bushing 42 having an outer diameter that allows the outer diameter to be fitted to the small diameter shaft portion 40 is press-fitted and fixed to the pin hole 41 so as to be fitted to the small diameter shaft portion 40 of the driving pins 30 and 31. The drive pins 30 and 31 having a length that does not project from the piston arms 28a and 28b and 29a and 29b are attached to the piston arms 28a and 28b by the bushes 42. Fine 29a, 29b for retaining fixed to it can be.

6 and 7 show a modification of the guide member. The guide member 43 shown in this drawing is a tubular member provided on both left and right sides of the piston arms 28a, 28b and 29a, 29b and provided with left and right side wall portions 44a, 44b having the elongated guide holes 24, 25, respectively. It is formed of a body, and is internally fitted and fixed to the cylinder 20 in a state where the arcuate peripheral wall portions 45a and 45b connecting the both side wall portions 44a and 44b are in contact with the inner surface of the cylinder 20. Then, both ends of the drive pins 30, 31 projecting from the piston arms 28a, 28b and 29a, 29b to the left and right sides are provided with the left and right side wall portions 4 via rollers 34 and 35, respectively.
4a and 44b are fitted in the respective guiding long holes 24 and 25. In this case, one driven arm 26 having both ends fitted between the pair of left and right piston arms 28a and 28b and between the piston arms 29a and 29b is attached to the driven rotary shaft 21.

In the embodiment shown in FIG. 8, both pistons 28,
29 is configured to be urged by a spring in the retreat direction. That is, a spring case 46 is attached to the end of the cylinder 20 on the piston 28 side in place of the end face plate, and, for example, double compression coil springs 47a and 47b of the inner and outer sides are interposed between the spring case 46 and the piston 28. Then, the pistons 28 and 2 are interlocked so as to move in opposite directions via the driven arms 26a and 26b.
9 is biased in the retreat direction by the springs 47a and 47b. In this case, both cylinder chambers 39A, 39B
Is constantly opened to the atmosphere via a passage 38 and supplies pressurized air to a cylinder chamber 37 between the pistons 28, 29, thereby causing the pistons 28, 29 to move to a spring 47a,
By advancing and moving against the urging force of 47b and opening the cylinder chamber 37 to the atmosphere, both pistons 28,
29 can be moved back and forth by the urging force of the springs 47a and 47b. Of course, both pistons 28 and 29 can be urged in the retreat direction by springs.

[0019]

As described above, in the double piston type torque actuator of the present invention, the piston side is driven with respect to the side surface of the driven elongated hole of the driven arm which is inclined with respect to the cylinder axis direction. As a result of the pin moving and pressing in the axial direction of the cylinder, a very large lateral component force acting on the drive pin position of the piston arm is fixed to the cylinder at the position of the drive pin, which is the position where the force is generated. Since it is received by the side surface of the guide elongated hole in the guide member, the reaction force thereof does not act on the piston arm provided with the drive pin, and therefore no moment is generated in the piston arm. Of course, both pistons can only move linearly in the cylinder axial direction by fitting the guide elongated hole parallel to the cylinder axial direction and the driving pin, and there is no fear of tilting.

From the above, according to the torque actuator of the present invention, there is no possibility that an extremely large lateral pressing force acts between the piston and the cylinder at the time of driving, and the stiffness of the piston at the time of driving is eliminated. Therefore, the sliding resistance of the piston is significantly reduced, and it is possible to obtain a torque actuator having a mechanical efficiency far superior to that of the conventional torque actuator. In particular, the structure of the present invention is applicable to an actuator of a type in which a piston is easily damaged, that is, a double piston type torque actuator of a type in which a piston is biased in a retracting direction by a spring as shown in FIG. It is extremely effective.

Further, according to the structure of the present invention, the piston arm is provided with a drive pin so that the inner side surface of the piston arm can contact the driven rotary shaft even when the piston moves to the advance limit position as in the conventional case. Since it is not necessary to extend it rearward from the mounting position, and it is sufficient that the driving pin can be mounted, the length of the piston arm is only L compared to the conventional structure shown in FIG. Can be made short. Therefore, the distance between the two pistons can be shortened when both pistons are in the retracted limit position, so that the overall size and weight of the actuator can be reduced.

In summary, according to the present invention, a smooth operation of the piston can be realized, and a torque actuator having a very small size and a high output can be obtained.

[Brief description of drawings]

FIG. 1A is a vertical sectional side view when both pistons are in a retracted limit position, and B is a vertical sectional front view.

FIG. 2 is a vertical cross-sectional side view when both pistons are at the advance limit position.

FIG. 3 is a front view of a guide member, and FIG. 3 is a vertical side view of the same.

FIG. 4 is a partially longitudinal front view of a main portion for explaining another embodiment of the drive pin retaining structure.

5 is a perspective view showing the drive pin of FIG. 4 and a bush fitted on one side. FIG.

FIG. 6 is a partial vertical cross-sectional side view of a main portion for explaining another embodiment of the guide member.

FIG. 7 is a vertical sectional front view of the same portion.

FIG. 8 is a vertical cross-sectional side view for explaining an embodiment applied to a torque actuator of a combined spring type.

FIG. 9 is a vertical cross-sectional side view showing a torque actuator of a conventional configuration in a state where both pistons are in a retracted limit position.

FIG. 10 is a vertical cross-sectional side view showing a torque actuator having a conventional configuration in a state in which both pistons are in an advance limit position.

[Explanation of symbols]

 20 Cylinder 21 Driven Rotating Shaft 22 Plate-shaped Guide Member 24 Guide Long Hole 25 Guide Long Hole 26a Driven Arm 26b Driven Arm 28a Piston Arm 28b Piston Arm 29a Piston Arm 29b Piston Arm 30 Drive Pin 31 Drive Pin 32 Driven Long hole for driving 33 long hole for driving 34 roller (needle bearing) 35 roller (needle bearing) 40 small diameter shaft part at both ends of drive pin 42 bushing 43 cylindrical guide member 47a piston biasing spring 47b piston biasing spring

Claims (4)

[Claims] 1. A movable piston is arranged on both sides of a driven rotary shaft, and piston arms parallel to each other are sandwiched between the pistons so as to sandwich the driven rotary shaft. In a double-piston type torque actuator comprising driven arms extending on both sides in the diametrical direction, provided with elongated driven holes into which driving pins projecting from the piston arms are fitted, on both ends of the driven arms. Double piston type torque actuator in which a guide member is fixedly installed in the cylinder, and a long guide hole parallel to the cylinder axis direction is provided in the guide member so that the drive pins of both piston arms are fitted therein. .. 2. A pair of left and right piston arms are arranged side by side, the driving pins are bridged between the pair of left and right piston arms, and the guide member is arranged between the pair of left and right piston arms. It consists of a single plate,
2. The double piston type torque actuator according to claim 1, wherein a central portion of the drive pin penetrates a long guide hole of the guide member. 3. The guide member comprises a cylindrical body provided on both left and right sides of the piston arm and having left and right side wall portions each having the elongated guide hole, and projects from the piston arm to both left and right sides. 2. The double piston type torque actuator according to claim 1, wherein both ends of the driving pin are fitted into the respective guiding long holes of the left and right side wall portions. 4. A roller fitted into a long guide hole of the guide member is supported by the drive pin.
A double-piston torque actuator according to any one of 1.