JPH07111202B2 - Double piston type torque actuator - Google Patents

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. 8, pistons 2 and 3 that can move independently are arranged on both sides of the driven rotary shaft 1, and piston arms parallel to each other so as to sandwich the driven rotary shaft 1 from both pistons 2 and 3. The piston arms 2a, 3a are connected to each other, and the piston arms 2a,
Driven elongated holes 7 and 8 into which drive pins 5 and 6 projecting from 3a are fitted are provided. 9 is a cylinder, 10
Is a stopper bolt for piston advance limit, 11 is a stopper bolt for piston retreat limit, 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 there.

In this torque actuator, as shown in FIG. 7, a direction in which the pistons 2 and 3 are separated from each other by supplying pressurized air to the piston inner cylinder chamber 13 from a state where the 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 via 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. 8, and one piston 3 comes into contact with the piston advance limit stopper bolt 10 and stops. From this state, when pressure air is supplied to the piston outer cylinder chambers 15A and 15B to move the pistons 2 and 3 back and forth in a direction in which they approach each other, the driving pins 5 and 6 of the piston arms 2a and 3a are driven. Both ends of the driven arm 4 are pressed in opposite directions via the elongated holes 7 and 8 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. 7, 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. 8, 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 is in the vertical posture with respect to the cylinder axis, the driven elongated hole 7 of the driven arm 4 under load,
By the pressing action of the driving pins 5 and 6 on the oblique side surface of 8, the component force F to the side where the driven rotary shaft 1 is located acts on the positions of the driving pins 5 and 6 of the piston arms 2a and 3a. . Of course, the component force F becomes smaller 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 in which the posture tilts in the opposite direction from the posture perpendicular to the axial direction, the component force F
The direction of action of becomes 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 an outward component force. 2a, 3a)
Since it is configured to prevent the tilting of the piston arms 2a and 3a, the contact point P between the piston arms 2a and 3a and the driven rotary shaft 1 will be described. 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 to move from the retreat limit position or the advance limit position where the component force F is the maximum, the component force F causes a large contact point P with the driven rotary shaft 1 as a fulcrum. The moment acts on the piston arms 2a and 3a,
This moment causes an extremely large lateral pressing force f between the pistons 2, 3 and the cylinder 10, and this extremely large lateral pressing force f significantly increases the sliding friction of the pistons 2, 3. , The mechanical efficiency of this torque actuator was to be significantly reduced.

Further, as shown in FIG. 8, even when the pistons 2 and 3 at the advance limit position start to retreat, the component force F acting on the piston arms 2a and 3a is applied to the driven rotary shaft 1.
In order to receive the above, the inner 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 in the advance limit position. Therefore, it is necessary to extend the piston arms 2a and 3a rearward from the mounting positions of the drive pins 5 and 6 as shown in the figure, and the length that is originally long enough to mount the drive pins 5 and 6 is required. 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. 7, the distance between the pistons 2 and 3 at the retracted limit position becomes long, the cylinder length for obtaining the necessary piston stroke becomes long, and 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 are shown by the reference numerals of the embodiments described later. The double-piston type torque actuator of the present invention includes pistons 28, 2 which are movable on both sides of a driven rotary shaft 21.
9 are provided, and the driven rotary shaft 21 is
Parallel to each other so as to sandwich the piston arm, and driving arms projecting from the piston arms are provided at both ends of the driven arms (26a, 26b) extending from the driven rotary shaft 21 to both sides in the diametrical direction. In a double piston type torque actuator provided with driven long holes 32 and 33 into which pins 30 and 31 are fitted, a pair of left and right piston arms (28a, 28b) (29a, 29b) are arranged side by side, and Each of the driving pins 30 and 31 has a pair of left and right piston arms (28a and 28b) (29a and 29a).
b) installed between the two pistons 28, 29 and inside the cylinder 20 between the two pistons 28, 29, one pair of left and right piston arms (28
a, 28b) to the other left and right pair of left and right piston arms (29a, 29b), and a guide member 22 formed of a single plate body through which the driven rotary shaft 21 penetrates through the central portion of the guide member 22 It is characterized in that it is internally fitted and fixed in a position, and elongated guide holes 24 and 25 into which the central portions of the drive pins 30 and 31 are fitted are provided in the guide member 22 in parallel with 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 10 and 11 described in FIG. 7 are omitted. . In FIGS. 1 to 3, reference numeral 20 denotes a cylinder, and a driven rotary shaft 21 is supported in a state of penetrating the center of the cylinder. A drive shaft of a butterfly valve or the like is connected to the one-end square hole portion 21a of the driven rotary shaft 21.

Reference numeral 22 is a guide member formed of a single plate body, which is fitted and fixed in the diametrical direction at the center of the cylinder 20, and as shown in FIGS. 3A and 3B, the driven rotary shaft 2 is provided at the center.
1 has a hole 23 penetrating therethrough, and elongated guide holes 24, 25 are provided on both upper and lower sides in parallel with the cylinder axis direction. Driven arms 26a, 2 that sandwich the guide member 22 and extend to both sides in the diametrical direction are attached to 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).
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, and these piston arms 28a to 29b are driven by the driven shafts. As shown in FIG. 1B, the driven arm 26a, the driven arm 26a,
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 arm 28a, 28b side are formed. 30 is
One of the driven elongated holes 32 and the guiding elongated hole 2 of the guide member 22.
5, the driving pin 31 on the side of the piston arms 29a and 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 formed in a portion of the driving 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 two pistons 28, 29 are moved forward in a direction in which they are separated from each other, the driving pins 30, 31 of the respective piston arms 28a, 28b and 29a, 29b are driven via the driven elongated holes 32, 33. 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 the pistons 28 and 29 back and forth in a direction in which they approach each other, As shown in FIG. 1A, the driving pins 30, 31 of the piston arms 28a, 28b and 29a, 29b press the opposite ends of the driven arms 26a, 26b in opposite directions via the driven elongated holes 32, 33, respectively. 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, as a result, 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 force component 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 pistons 28 and 29 have the driving pins 30 and 25 in the elongated guide 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 the stop rings 36 in the circumferential grooves formed at both ends thereof, and 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 come into contact with 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 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. A small-diameter shaft portion 40 is formed, and a pin hole 41 having an inner diameter through which the driving pins 30 and 31 can be inserted is machined in the piston arms 28a, 28b and 29a, 29b, and press-fitted and fixed in the pin hole 41. A bush 42 having an outer diameter which allows the outer diameter to be fitted to the small-diameter shaft portion 40 and is press-fitted and fixed to the pin hole 41 so as to be fitted to the small-diameter shaft portion 40 of the drive pins 30 and 31. The drive pins 30, 31 having a length that does not project from the piston arms 28a, 28b and 29a, 29b are attached to the piston arms 28a, 28b by the bushes 42. Fine-29a, it can be fastened missing for 29b.

In the embodiment shown in FIG. 6, 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 instead 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 by supplying pressurized air to the cylinder chamber 37 between the pistons 28, 29, the pistons 28, 29 are connected to the springs 47a, 47a.
By moving the piston chamber 37b forward against the urging force of the cylinder 47b to open 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 biased in the retreat direction by springs.

[0018]

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 pin is generated. Since it is received by the side surface of the guide long 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 axis direction by fitting the guide elongated hole parallel to the cylinder axis direction and the driving pin, and there is no risk of tilting.

Further, according to the structure of the present invention, since the guide member is a component separate from the cylinder, the guide member alone can be machined with high precision. Therefore, the two guide pins for guiding the driving pin can be processed. Since it is easy to secure the parallelism and dimensional accuracy of the long guide holes, and of course, the surface hardening treatment is easy, the guide member can be manufactured at low cost, and the guide member due to wear can be easily replaced. However, in particular, since the pair of left and right piston arms are arranged side by side and the guide member is composed of a single plate body that is internally fitted and fixed in the center position of the cylinder so as to be loosely fitted between them, In addition, by simply processing both side surfaces of the plate-shaped guide member parallel to the cylinder axis direction to arc-shaped surfaces that contact the inner peripheral surface of the cylinder, the guide member fitted inside the cylinder automatically Center position Would be accurately positioned, the incorporation accuracy of the guide member relative to the cylinder can be easily increased.

The pair of left and right piston arms are
Since it reciprocates with the plate-shaped guide member accurately positioned at the cylinder center position as described above,
The plate-shaped guide member can also prevent the piston arm projecting cantilevered from the piston from swinging in the plate-thickness direction of the plate-shaped guide member. Therefore, the smooth movement of the piston is not obstructed by the swing of the piston arm. Furthermore, since the arms of both pistons are guided by one plate-shaped guide member, relative twist in the cylinder circumferential direction does not occur between both pistons.

For the above reasons, according to the torque actuator of the present invention, the friction of the piston during driving is eliminated and the sliding resistance of the piston is remarkably reduced, which is far more mechanically efficient than the torque actuator of the conventional construction. An excellent torque actuator can be obtained extremely easily, easily and inexpensively. In particular, the actuator of the type in which the piston is apt to generate, that is, the double piston type torque actuator of the type in which the piston is biased by the spring in the retracting direction as shown in FIG.
The configuration of the present invention is extremely effective.

[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 the guide member, and FIG. 3B is a vertical sectional side view of the same.

FIG. 4 is a partial vertical cross-sectional 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 vertical cross-sectional side view for explaining an embodiment applied to a torque actuator combined with a spring.

FIG. 7 is a vertical cross-sectional side view showing a torque actuator having a conventional configuration in a state where both pistons are in a retracted limit position.

FIG. 8 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 Long Guide Hole 25 Long Guide 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 use 33 long hole for driven 34 roller (needle bearing) 35 roller (needle bearing) 40 small diameter shaft part at both ends of drive pin 42 bush 47a piston biasing spring 47b piston biasing spring

Claims (1)

[Claims] 1. A movable piston is provided 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. at both ends of the driven arms extending diametrically opposite sides, the pin drive protruding from the respective piston arm at the double piston type torque actuator comprising providing a driven long hole to be fitted, each Pisuton'a
A pair of left and right arms are arranged side by side, and the drive pins are
Installed between each pair of left and right piston arms,
In the cylinder between the two
Between the left and right pair of piston arms
One plate which is continuous and has the driven rotary shaft passing through the central portion thereof
A guide member consisting of a body is fitted and fixed at the center of the cylinder.
However, the central portion of each drive pin is
Long guide holes that fit together are provided parallel to the cylinder axis.
Double piston type torque actuator comprising Te.