JPH07269510A - Double acting type two step opening and closing actuator - Google Patents

Abstract

PURPOSE:To provided the double acting type two step opening and closing actuator which can surely open and close a valve at the three positions of a fully closed, an intermediate and a fully opened position, is in a balanced shape, and is less in the amount of pressure fluid consumption. CONSTITUTION:A cylinder means 5 allowing a piston rod 2 to be reciprocated by a small diameter piston 6, is connected to one side of a motion converting mechanism 4, and a cylinder mechanism 7 the inner cross sectional area of which is roughly five times as large as that of the cylinder means, is connected to the other side of the mechanism, the piston rod 2 is penetrated through the center hole 8a of the aforesaid large diameter piston 8, and a locking section 9 is provided at the head of the rod. The movement of the large diameter piston 8 until it is brought into contact with a stopper means 19 permits a valve to be opened up to an intermediate position, under which condition, the valve is opened up to a fully opened position, and is also closed to the intermediate position while a small diameter piston 6 is being reciprocated over a remaining stroke, and after that, the valve is fully closed only with the small diameter piston 6 operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-acting two-stage open / close actuator used for opening / closing a valve in three positions, ie, a fully closed position, an intermediate position and a fully opened position.

[0002]

2. Description of the Related Art Conventional conventional double-acting rotary actuators are for operating a ball valve or a butterfly valve from fully closed to fully open, and from fully open to fully closed. The flow rate could not be adjusted. For this reason, a double-acting two-stage open / close rotary actuator that can open the valve at an intermediate opening has been developed. 4, 5, and 6 are cross-sectional views showing an example of these double-acting two-stage open / close rotary actuators disclosed in Japanese Utility Model Publication No. 61-19206.

4 to 6, pistons 32 and 33 of a double-acting cylinder device 31 are connected to a connecting rod 34, and the motion converting device 35 acts to reciprocate the pistons 32 and 33 and the connecting rod 34. The movement is converted into rotational movement of the output shaft 36, and the output shaft 36 rotates the stems of the ball valve and the butterfly valve to open and close these valves. The piston rod 39 fixed to the piston 38 of the cylinder device 37 for intermediate opening projects into one cylinder chamber 40 of the double-acting cylinder device 31.

FIG. 4 shows the state when the valve is fully closed. The pressure fluid from the pressure fluid supply source 41 is sent to the cylinder chamber 43 through the electromagnetic switching valve 42, and the piston 32 is pressurized. When pushed by the fluid, the piston 33 connected thereto pushes the piston rod 39, and the piston 38 fixed thereto moves to the right until it comes into contact with the adjusting bush 44, and by the action of the motion conversion device 35. The output shaft 36 fully closes the valve. Therefore, the adjusting bush 44 serves as a stopper for the rightward movement of the double-acting cylinder device 31. To adjust the position of the stopper, loosen the cap nut 46 and the nut 45, screw the adjusting bush 44 into the end cap 47,
Then screw it out. The stopper for the leftward movement of the double-acting cylinder device 31 is the bolt 48, and the stopper position is adjusted by screwing the bolt 48 into or out of the head cap 49. The reason why the cylinder chamber 43 is cross-hatched is to show that this portion is in a pressurized state. In FIG. 5 and FIG. 6 as well, the cross-hatched portions are similarly pressurized portions.

FIG. 5 shows a state in which the valves are fully opened. From the state shown in FIG. 4, electromagnetic switching valves 42 and 50 are shown.
The pressure fluid from the pressure fluid supply source 41 is sent to the cylinder chambers 40 and 51, and the pistons 33 and 38 are switched.
Are both pushed to the left and moving. The piston 33 is moved until the piston 32 comes into contact with the bolt 48, and the valve is fully opened by the action of the motion conversion device 35. The movement of the piston 38 is until the nut 52 screwed into and fixed to the piston rod 39 comes into contact with the right end of the adjustment bush 44, and the nut 52 adjusts the movement of the piston 38 to the left together with the nut 53. Is provided.

FIG. 6 shows a state in which the valve has reached an intermediate opening. The electromagnetic switching valve 42 is switched from the state of FIG. 5, and the pressure fluid from the pressure fluid supply source 41 is sent to the cylinder chamber 43. The piston 32 is pushed to the right, and the piston 33 moves to the right until it abuts the piston rod 39 while discharging the fluid in the cylinder chamber 40 to the outside. The pressure fluid continues to act on the cylinder chamber 51. In this state, the cylinder chamber 4
Since 3 and 51 have the same pressure, the force that pushes the piston 32 to the right by the pressure fluid is more to the right from the piston 38 of the piston rod 39 than the force that pushes the piston 38 to the left due to fluid pressure. It is large by the force obtained by multiplying the cross-sectional area of the protruding portion 39a by the pressure of the pressure fluid. Therefore,
If there is no resistance to these moving parts, these moving parts will move to the right. In reality, the double-acting cylinder device 31 consumes much of the output to move the pistons 32 and 33, the motion conversion device 35, and the valve, and the force that pushes the piston rod 39 to the right is Even if the force obtained by multiplying the pressure receiving area of the piston 32 by the pressure of the pressure fluid is large, it is only 75%. On the other hand, the cylinder device 37 for the intermediate opening degree is also smaller than the force obtained by multiplying the pressure receiving area of the piston 38 by the pressure of the pressure fluid due to the frictional resistance of the moving portion, but even if it is small, it is 90%. Due to the force relationship, the piston 32 cannot push the piston rod 39 to the right and move further from the state shown in the figure. Therefore, the valve is maintained at the intermediate opening degree.

The actuator shown in FIGS. 4 to 6 is
The double-acting two-stage opening / closing rotary actuator as described above is unstable due to the delicate action of the intermediate stop as described above, and the cylinder device 37 for the intermediate opening has a double action. Since the actuator is provided outside the operating cylinder device 31, the entire actuator is extremely long, and there is a problem that the left and right are not balanced with respect to the output shaft 36. However, since the cylinder unit 37 for intermediate opening consumes the pressure fluid for each operation, the consumption amount of the pressure fluid is large, and there is a drawback that the equipment cost and the operating cost therefor are increased.

[0008]

SUMMARY OF THE INVENTION As described above, the present invention is directed to the fact that the conventional double-acting rotary actuator cannot have an intermediate opening, and the double-acting two-stage opening / closing capable of having an intermediate opening. Type double-acting two-stage rotary actuator that solves problems such as extremely long shape, unbalanced left and right, unstable stop at intermediate opening, large consumption of pressure fluid, etc. The purpose of the present invention is to provide an opening / closing actuator.

[0009]

In order to solve the above problems, the present invention has a double-acting two-stage open / close type actuator configured as follows. On one side of the motion conversion mechanism that converts the reciprocating motion of the piston rod into the rotary motion of the output shaft,
A small-diameter piston fixed to the piston rod is connected to a double-acting cylinder device that alternately applies a pressure fluid to the piston rod to reciprocate the piston rod. A cylinder mechanism that is approximately twice the inner cross-sectional area of the device is connected, the piston rod penetrates the center hole of this large-diameter piston, and the pressurized fluid acts on the large-diameter piston to move the piston rod After moving a fixed distance, the cylinder device can reciprocate the rest of the stroke in this state, and the cylinder device moves the piston rod to its full stroke with no pressure fluid acting on the large diameter piston. It has a two-stage open / close type so that the stroke can be reciprocated.

In this case, the cylinder device and the cylinder mechanism are provided with stopper devices for adjusting the positions of both ends of the stroke of the reciprocating motion of the piston rod, and the cylinder mechanism is provided with stopper devices for adjusting the moving distance of the large diameter piston. preferable.

[0011]

Since the present invention is configured as described above, in the closed state in which the pressure fluid is fed into the cylinder chamber on the side closer to the motion conversion mechanism than the small diameter piston of the cylinder device, the large diameter piston of the cylinder mechanism is operated. When the pressure fluid is fed into the cylinder chamber on the side closer to the motion conversion mechanism, the inner cross-sectional area of the cylinder mechanism is almost twice the inner cross-sectional area of the cylinder device,
Since the cylinder mechanism has a larger output, the large-diameter piston moves, pushes the retaining lock of the piston rod, moves the piston rod toward the cylinder mechanism by a certain distance, and opens the valve in the middle. Every time. During this time, the pressure fluid in the cylinder chamber on the side closer to the motion converting mechanism than the small diameter piston of the cylinder can be returned to the piping system of the pressure fluid without being discharged to the outside.

Next, when the connection of the pressure fluid to the cylinder device is switched to the opposite side of the small diameter piston, the small diameter piston slides the piston rod through the center hole of the large diameter piston, moves the remaining stroke, and fully opens the valve. Put in a state. During this time, the pressure fluid in the cylinder chamber on the side closer to the motion conversion mechanism than the small diameter piston of the cylinder is discharged to the outside.

Next, when the connection of the pressure fluid to the cylinder device is switched to the opposite side of the small diameter piston (the side close to the motion conversion mechanism), the small diameter piston has the piston rod retaining locking portion first for a certain distance. The valve moves to an intermediate opening by moving until it moves to the large-diameter piston that has moved. Further, when the pressure fluid of the cylinder mechanism is discharged to the outside, the small-diameter piston holds the piston rod and the locking portion pushes the large-diameter piston to move the valve until the valve is fully closed.
During the valve closing stroke of the small diameter piston, the pressure fluid in the cylinder chamber on the side farther from the motion converting mechanism than the small diameter piston of the cylinder device is discharged to the outside.

The operation of the double-acting two-stage open / close type actuator that opens in two stages and closes in two stages has been described above. It is also possible to open and close in two stages or open in two stages and close in one stage, and it is also possible to perform one-stage opening and one-stage closing only by the cylinder device without feeding pressure fluid to the cylinder mechanism.

This actuator has a balanced shape by providing a double-acting cylinder device on one side of the motion converting mechanism and a cylinder mechanism for intermediate opening on the other side. By making the inner cross-sectional area of the cylinder almost twice as large as the inner cross-sectional area of the cylinder, there is almost no change in the output throughout the stroke, and at the intermediate opening, the cylinder device and cylinder mechanism on both sides pull the piston rods in opposite directions. In addition, the piston rod is stopped in a state of being moved by a certain distance by the cylinder mechanism, and is in an extremely stable state.

Further, as described above, this actuator can return the pressure fluid discharged from the cylinder device to the piping system of the pressure fluid without being discharged to the outside when rotating from the closed state to the intermediate opening degree. Therefore, consumption of the pressure fluid is small throughout. Therefore, the facility cost and the operating cost for the pressure fluid can be reduced accordingly.

[0017]

1 and 2 are sectional views showing an embodiment of a double-acting two-stage open / close type actuator of the present invention, and these three drawings are the same for explanation. It shows different states. The cross-hatched portions in these figures are the portions in the pressurized state. 1 to 3, 1 is a double-acting two-stage opening / closing actuator, 2 is a piston rod, 3 is an output shaft, and 4 is a motion conversion mechanism for converting reciprocating motion of the piston rod 2 into rotational motion of the output shaft 3. Is. Reference numeral 5 is a cylinder device connected to one side of the motion converting mechanism, 6 is a small diameter piston, and the small diameter piston is fixed to one side of the piston rod 2, and the pressure fluid is alternately applied to both sides of the small diameter piston. Then, the piston rod 2 is reciprocated.

Reference numeral 7 is a cylinder mechanism connected to the other side of the motion converting mechanism 4, 8 is a large-diameter piston thereof, and the inner cross-sectional area of the cylinder mechanism 7 is almost 2 times the inner cross-sectional area of the cylinder device 5.
The cylinder chamber on the side close to the motion conversion mechanism 4 of the large-diameter piston 8 has the piston rod 2 penetrating the center hole 8a of the large-diameter piston 8 and the retaining locking portion 9 formed at the tip thereof. The large-diameter piston 8 is moved to the left by applying pressure fluid to the large-diameter piston 10, the large-diameter piston 8 pushes the retaining locking portion 9, and the piston rod 2 is moved to the left until the large-diameter piston 8 contacts the stopper 11. Can be moved to.

In this state, the piston rod 2 can reciprocate the remaining stroke to the left and to the right by the action of the cylinder device 5. Further, the piston rod 2 can reciprocate the entire stroke by the action of the cylinder device in the state where the pressure fluid is not fed into the cylinder mechanism 7 and the pressure fluid is not acting on the large diameter piston 8.

Bolts 12 attached to the cylinder device 5
The nut 13 and the nut 13 are a stopper device 14 that adjusts the position of the right end of the stroke of the reciprocating motion of the piston rod 2, and as shown in the figure, the stopper 11
The bolt 16 and the nut 17 attached via the cap 15 and the cap 15 are a stopper device 18 for adjusting the position of the left end of the stroke of the reciprocating motion of the piston rod 2. Also,
The stopper 11 is a stopper device 19 that adjusts the moving distance of the large-diameter piston 8 attached to the cylinder mechanism 7.

Next, the operation of the double-acting two-stage open / close type actuator 1 will be described with reference to FIGS. FIG. 1 shows a state in which the valve is fully closed. The pressure fluid sent from the pressure fluid supply source 21 to the cylinder chamber 20 on the left side of the small diameter piston 6 of the cylinder device 5 through the electromagnetic switching valve 22. Flows in to move the small-diameter piston 6 to the right, and the valve is fully closed via the piston rod 2, the motion conversion mechanism 4, and the output shaft 3.

In this state, when the electromagnetic switching valve 23 is moved to the cylinder chamber 10 as shown in FIG. 2, the inner cross-sectional area of the cylinder mechanism 7 becomes almost twice the inner cross-sectional area of the cylinder device. Since the output of the cylinder mechanism 7 is larger, the large-diameter piston 8 moves to the left and pushes the retaining lock 9 of the piston rod 2 to push the piston rod 2 into contact with the stopper 11. The valve is set to an intermediate opening degree via the piston rod 2, the motion conversion mechanism 4, and the output shaft 3 until the valve is brought into contact with the valve. FIG. 2 shows a state when the valve has an intermediate opening degree in this way. While the state of FIG. 1 is changed to the state of FIG. 2, the pressure fluid in the cylinder chamber 20 is not discharged to the outside, but flows into the cylinder chamber 10 via the electromagnetic switching valve 22 and then the electromagnetic switching valve 23.

Next, when the pressure fluid is fed into the cylinder chamber 24 on the right side of the piston small diameter 6 of the cylinder device 5 as shown in FIG. 3 by the electromagnetic switching valve 22, the small diameter piston 6 causes the piston rod 2 to have a large diameter. The center hole 8a of the piston 8 is slid to move the remaining stroke until the piston rod 2 contacts the bolt 16 to fully open the valve. FIG. 3 shows a state in which the valve is fully opened in this way. Note that the pressure fluid in the cylinder chamber 20 is discharged to the outside through the electromagnetic switching valve 22 while the state of FIG. 2 is changed to the state of FIG.

Next, when the pressure switching fluid is fed into the cylinder chamber 20 by setting the electromagnetic switching valve 22 as shown in FIG. 2, the small diameter piston 6 is moved by the retaining locking portion 9 as shown in FIG. It moves to the right until it comes into contact with the large-diameter piston 8, and the valve is returned to the intermediate opening degree via the piston rod 2, the motion conversion mechanism 4, and the output shaft 3. The state at this time is the same as that in FIG. During the transition from the state of FIG. 3 to the state of FIG. 2, the pressure fluid in the cylinder chamber 24 is discharged to the outside through the electromagnetic switching valve 22.

Next, when the electromagnetic switching valve 23 is as shown in FIG. 1, the pressure fluid in the cylinder chamber 10 of the cylinder mechanism is discharged to the outside through the electromagnetic switching valve 23, and the small diameter piston 6 is stored in the cylinder chamber 20. The valve is fully closed by being pushed by the pressurized fluid and moving to the right while pushing the large-diameter piston 8 to the right with the retaining locking portion 9 until the piston rod 2 contacts the bolt 12. At this time, the position of the large-diameter piston 8 is slightly different, but the state is as shown in FIG. While the state in FIG. 2 is changed to the state in FIG.
Is released to the outside via

The operation of the double-acting two-stage open / close type actuator for opening the valve in two stages, the intermediate opening and the full opening, and the two-stage closing to the intermediate opening and the full closing, has been described above. The valve can be opened in one stage and closed in two stages, or can be opened in two stages and closed in one stage by continuously connecting before and after the state of the intermediate opening shown in FIG. It is also possible to open the valve in one stage and close the valve in one stage by switching the feeding of the pressure fluid to the cylinder device 5 by the electromagnetic switching valve 22 while keeping the switching valve 23 in the state shown in FIG.

[0027]

As described above, the double-acting two-stage open / close type actuator of the present invention is provided with the cylinder device on one side and the cylinder mechanism on the other side around the motion conversion mechanism. Since it has a balanced shape, and the inner cross-sectional area of the cylinder mechanism is twice as large as that of the internal cutting device of the cylinder device, the output hardly changes throughout the stroke, and both cylinder devices and the cylinder mechanism do not change at the intermediate opening. The piston rods are attracted to each other, and are stopped in a state where they are moved by a certain distance by the cylinder mechanism, and are in an extremely stable state. An even greater effect is that the pressure fluid discharged from the cylinder device is not discharged to the outside during the period from the valve closed state to the intermediate opening degree, and can be returned to the piping system of the pressure fluid, so the consumption amount of the pressure fluid is small. That is, the facility cost and operating cost for the pressure fluid can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a double-acting two-stage open / close type actuator of the present invention.

FIG. 2 is a cross-sectional view showing a state when the valve of FIG. 1 is set to an intermediate opening degree.

3 is a cross-sectional view showing a state in which the valve of FIG. 1 is fully opened.

FIG. 4 is a vertical sectional view showing an example of a conventional double-acting two-stage open / close rotary actuator.

5 is a sectional view showing a state when the valve of FIG. 4 is set to an intermediate opening degree.

6 is a cross-sectional view showing a state where the valve of FIG. 4 is fully opened.

[Explanation of symbols]

 1 Double-acting two-stage open / close actuator 2 Piston rod 3 Output shaft 4 Motion conversion mechanism 5 Cylinder device 6 Small diameter piston 7 Cylinder mechanism 8 Large diameter piston 8a Center hole 9 Detent locking part 14, 18, 19 Stopper device

Claims (2)

[Claims] 1. A piston rod is operated by alternately applying a pressure fluid to both sides of a small-diameter piston fixed to the piston rod, on one side of a motion converting mechanism that converts the reciprocating motion of the piston rod into the rotary motion of the output shaft. A double-acting cylinder device for reciprocating motion is connected, and the inner cross-sectional area of the other side of this motion conversion mechanism is approximately 2 times the inner cross-sectional area of the cylinder device.
Double the cylinder mechanism, connect the piston rod through the center hole of this large-diameter piston, and apply pressure fluid to the large-diameter piston to move the piston rod a certain distance of its stroke. With the cylinder device, the piston rod can reciprocate the rest of the stroke, and the cylinder device can reciprocate the entire stroke of the piston rod with no pressure fluid acting on the large diameter piston. A double-acting two-stage open / close type actuator characterized by being configured as a two-stage open / close type. 2. The cylinder device and the cylinder mechanism are provided with stopper devices for adjusting the positions of both ends of the stroke of the reciprocating motion of the piston rod, and the cylinder mechanism is provided with stopper devices for adjusting the moving distance of the large diameter piston. The double-acting two-stage open / close type actuator according to claim 1.