JPS581444B2 - Actuator Seigiyokikou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an actuator that performs reciprocating motion within a finite range to drive an operated object, and when the output of the actuator exceeds a preset value or when the actuator reaches a predetermined limit. This invention relates to an actuator control mechanism that automatically stops an actuator when the actuator moves to a certain position.

Such an actuator control mechanism not only operates in the event of an abnormality such as an accident, but also has the function of determining the reciprocating range and stop position of the actuator.

To explain an actuator that opens and closes a valve as an example, when the valve body connected to the actuator is driven to the valve closing position, that is, the position where it comes into close contact with the valve seat,
Since the movement of the valve body is stopped, the output of the actuator becomes larger than the set value and the drive of the actuator is stopped.

Furthermore, if a stopper or the like that engages with the valve body is provided even in the valve open position, the stop position of the actuator can be determined by the actuator control mechanism using excessive output.

When the opening degree of the valve is desired to be set arbitrarily, the reciprocating range and stop position of the actuator can be arbitrarily determined by using an actuator control mechanism based on the operating position.

Such control mechanisms are rarely used alone;
Usually, an actuator control mechanism based on excessive output and an actuator control mechanism based on operating position are used together, and control operations are performed in conjunction with each other.

If each control mechanism operates a separate control element when performing this linked control operation, a logic circuit must be provided to determine and select the output of each control element according to the control mode of the operated object. Therefore, a configuration in which each control mechanism operates the same control element and the selection of the control mechanism is mechanically set has been put into practical use.

However, this type of actuator control mechanism generally has a very complex structure.

In particular, the malfunction prevention mechanism that prevents the control mechanism from malfunctioning due to excessive output at startup when the operated object is driven to its extreme position, stopped, and then begins to move in the opposite direction is complex and frequently malfunctions.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome these drawbacks of conventional devices and provide an actuator control mechanism having the above-mentioned functions with an extremely simple configuration.

Next, an embodiment in which the present invention is applied to a valve driving actuator will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention.

In the figure, reference numeral 1 denotes a power source for the actuator, which applies rotational torque to a worm shaft 2 serving as an output shaft.

This worm shaft is slidable in the axial direction and is engaged with an elastic member (not shown).

The rotation of the worm shaft 2 is transmitted to the worm wheel 3 via the worm 2', and drives the main shaft 4.

The main shaft 4 is connected to the valve, but when the load applied to the main shaft 4 increases, the worm shaft 2 is displaced by the axial thrust applied thereto.

When the elastic force generated in the elastic member due to this displacement and the magnitude of the load are balanced, the axial displacement of the worm shaft 2 is stopped and the main shaft 4 is driven.

In this way, the worm shaft 2 is always displaced in the axial direction in proportion to the output of the actuator.

On the other hand, in order to detect the rotational position of the main shaft 4, the position detection worm 5 attached to the king shaft 4 transmits rotation proportional to the rotation of the main shaft 4 to the engaged position detection worm wheel 6, and the position The limit shaft 7 coupled to the detection worm wheel 6 is also rotated.

Further, a torque push rod 8 mounted on the axis of the worm shaft 2 so as to be slidable in the axial direction transmits a deflection proportional to the output of the operating device to the control mechanism according to the invention.

Next, a mechanism for transmitting a displacement proportional to the output of the actuator will be explained with reference to FIG.

FIG. 2 shows a cross section of a portion that converts the axial displacement transmitted by the torque push rod 8 into rotational displacement.

In the figure, reference numeral 9 denotes a mounting base plate, one end of the lever base 10 is attached to this base plate 9 with a screw 11, and the other end of the lever base is attached to a set screw 12 and a tightening screw 13 that widen the distance from the base plate. is fixed to the base plate.

A lever 15 is supported by a pin 14 on the lever base 10 so as to be rotatable, and a spring 16 applied between the lever base 10 and the lever 15 is configured to constantly push the torque push rod 8.

A portion a of the lever 15 engages with a hole b of the link plate 17.

This engaged state is as shown in the side view of FIG.

When the valve connected to the main shaft 4 is driven toward the closed position and the torque push rod 8 is displaced to the right in FIG. is displaced upward.

When the valve is driven in the opening direction and the torque push rod 8 is displaced to the left by the driving torque, the lever 15 is rotated clockwise by the action of the spring 16 and the link plate 17 is displaced downward.

A coupler 18 is connected to a torque shaft 20 at its center and has a coupling pin 19 at its peripheral end.

The torque shaft 20 is engaged with an elongated hole C of the link plate 17, and the coupling pin 19 is engaged with a groove d provided at a side end of the elongated hole C.

Therefore, when the link plate 17 is displaced upward, the coupling pin 19 is engaged with the groove d, so the coupler 18 and the torque shaft 20 are rotated clockwise, and when the link plate 17 is displaced downward, Torque axis 2
0 rotates counterclockwise.

In this way, the axial displacement of the torque push rod is converted into a rotational displacement of the torque shaft 20 by the lever 15, the link plate 17 and the coupler 18.

Next, a section for setting the limit output of the actuator and a mechanism for operating the control element when the output of the actuator exceeds the limit output will be explained.

As shown in FIG. 1, a torque puller 21 is fixed to the other end of the torque shaft 20.

FIG. 4 is a view of the AA' cross section in FIG. 1 viewed from the right side, and the torque force puller 21 has a hollow structure inside.
A notch is provided in the peripheral wall.

Reference numeral 23 denotes a torque setting plate rotatably fitted onto the torque shaft 20, and a protrusion f of this torque setting plate engages with one end e of the notch.

The projection f is constantly pressed by the spring 22 against the end e of the torque puller.

Therefore, the normal torque setting plate 23 rotates integrally with the torque shaft 20.

Further, the upper end portion of the torque setting plate 23 is formed in an arc shape centered on the torque shaft 20, and a torque setting scale is provided in this portion.

FIG. 5 is a view of the BB' cross section of FIG. 1 viewed from the right side.

In the figure. 26 and 26' are torque setting pieces,
Each of them is rotatably fitted to the torque shaft 20.

The upper ends of both torque setting pieces protrude upward from the scale portion of the torque setting plate and act as torque setting guides.

24 and 24' are torque adjustment screws, which are screwed into female screw members g, h and g', h', respectively, which are fixed to the torque setting plate.

Before screwing in the adjustment screw, the female screw members g and g' are slightly deformed in the direction of the screw axis.
The adjustment screw is screwed in so that the pitches between the screws do not match, and the tightening effect due to the mismatch in pitch phase serves as a lock for the adjustment screw to loosen.

Reference numeral 25 denotes a spring that always presses the torque setting pieces 26 and 26' against the torque adjustment screw 24.24'. The amount of deviation from the center of the torque setting plate can be adjusted as desired.

Reference numeral 27 denotes a control element driving member, which is rotatably fitted around the torque shaft.

28 and 28' are control elements for stopping or driving the power source of the actuator.

This control element is connected to a solenoid valve that opens and closes a pressure oil supply path when the power source is a hydraulic motor, etc., and is connected to a control circuit such as an electromagnetic switch when an electric motor is used as the power source. .

The control element drive member 27 has two protrusions i and j, the protrusion i contacting the actuating parts of the control elements 28 and 28', respectively.

Therefore, the control element drive member 27 is normally held in a constant neutral position.

The protrusion j is located between the torque setting piece 26 and the torque setting piece 26'.

Next, the operation of the actuator control mechanism activated by this excessive output will be explained.

When the output of the actuator is zero, each member is in a neutral state as shown in Figure 5, but when the load applied to the valve increases after the actuator operates and the output of the actuator increases, the torque is set by the mechanism described above. The plate 23 rotates by an amount proportional to the output depending on the direction of movement of the actuator.

When this amount of rotation becomes equal to the opening angle from the center of the torque setting plate 23 to the torque setting piece, the torque setting piece comes into contact with the protrusion j of the control element drive member 27, and when the output of the actuator further increases, the torque setting piece protrudes. Since part j is pressed, the control element drive member rotates and the control element is actuated by the protruding section.

This state is shown in FIG.

FIG. 6 shows that when the valve is being driven toward the closed position, the output torque increases and the torque shaft rotates clockwise.
This is a state in which the torque striker 27 is driven to the control element operating position.

As mentioned above, the limit output is set by adjusting the opening angle from the center line xx' of the torque setting plate 23 to the torque setting piece, so when the output of the actuator is zero, this center line -X' is the control element driving member 27
It must be located over the center of the protrusion j provided in the.

If this position deviates, it can be adjusted by the mechanism shown in FIG. 2 that converts the linear displacement of the torque push rod 8 into a rotational displacement.

That is, in FIG. 2, when the output of the actuator is zero and the torque push rod 8 is kept at a constant position,
When the tightening screw 13 is loosened and the set screw 12 is rotated to adjust the opening between the mounting base plate 9 and the lever base 10, the torque shaft 20 is slightly rotated accordingly. center line x-x' and protrusion J
can be aligned with the center of

The actuator control mechanism based on excessive output has been described above, and next, the actuator control mechanism based on the operating position and the linked operation thereof will be explained.

In Fig. 1, 7 is a limit shaft that rotates in proportion to the amount of rotation of the main shaft 4, and the exposed part is threaded, and this part has a nut-shaped limit actuator (hereinafter referred to as 32 (referred to as a limit nut) is screwed in.

The limit nut 32 is provided with a groove k, and a rod-shaped end portion of a limit striker 35 rotatably fitted onto the torque shaft 20 is engaged with this groove k.

This limit striker 35 is normally held at a neutral position by a link return spring 33 and a pin 34 fixed to the housing.

29 is a clamper fitted into the groove k of the limit nut 32, and has a structure as shown in FIG.

Oval holes are provided on both sides of the clamper 29, and the limit shaft 7 is engaged with these holes.

Therefore, the clamper 29 can slide using the groove k of the limit nut as a guide, and is configured to constantly press the rod-shaped end of the limit striker 35 by the spring 30.

Furthermore, claws l and l' are provided on both sides of the clamper 29.

Reference numerals 36 and 36' designate limit setting members for determining the operating range of the actuator, each of which comprises an engaging nut m, a washer n, and a tightening nut 0.

This limit setting member can be moved to any position on the limit shaft by loosening tightening nut 0, and can be fixed to the limit shaft by tightening washer n and engagement nut m with tightening nut 0. can be done.

FIG. 8 is a cross-sectional view taken along the line CC' in FIG. 1, viewed from the right side. In the figure, 37 and 37' are limit control elements.

This limit control element is connected to an auxiliary circuit such as an actuator operation end position display circuit, and the power source of the actuator is stopped by operating the control elements 28 and 28' by an interlocking mechanism to be described later. ing.

In this embodiment, an actuator control mechanism using excessive output is used to detect when the valve is fully closed and stop the actuator drive line, and also to detect when the valve is fully closed and to stop the actuator drive line. An actuator control mechanism based on the operating position is used to stop the drive source.

Therefore, when the valve is driven to the closed position, the control mechanism based on the operating position only operates the aforementioned limit control element, and the actuator control mechanism based on excessive output stops the drive source of the actuator.

However, in this case, when driving the valve in the opening direction again, the starting torque becomes a very large value, and there is a risk that the actuator control mechanism may malfunction due to excessive output.

Therefore, a mechanism to prevent this is required.

Next, this mechanism will be explained with reference to the embodiment shown in the figure. In FIG. 1, when the main shaft 4 is driven once by the actuator in the direction of the solid line arrow (direction to close the valve), the worm 5 and the worm wheel 6 The rotation is transmitted to the limit shaft 7, and the limit shaft 7 rotates in the direction of the solid line arrow.

Since the limit nut 32 is prevented from rotating by the engagement between the groove k and the limit striker 35, it moves linearly to the left in FIG. 1 due to the rotation of the limit shaft.

When the limit nut 32 approaches the limit setting member 36, the claw l of the clamper 29 fits into a circular groove p provided in the engagement surface of the engagement nut m.

This state is shown in FIG. Figure 9 is D'-D' of Figure 1.
FIG. 3 is a cross-sectional view seen from the right side.

When the limit shaft further rotates from this state, the protrusion q of the engagement nut m engages with the protrusion r provided on the side surface of the limit nut 32, so the limit nut 32 is connected to the limit shaft via the limit setting member 36. It rotates in unison with 7.

When the limit nut 32 rotates, the rod-shaped end of the limit striker 35 that has been engaged with the groove k of the limit nut comes off from the groove and rides on the circumferential surface of the limit nut 32, as shown in FIG.

At this time, the end of the link return spring 33 is pushed open, so the limit striker 35
2 and the clamper 29 is pressed against the spring 30
, the claw l fits into the groove S provided on the peripheral end of the engagement nut m, and the end of the oval hole provided on the side of the clamper hits the limit shaft, so the first
It will stop in the state shown in Figure 0.

The position of the groove S is adjusted in advance so as to correspond to the claw of the clamper when the projection q of the engagement nut and the projection r of the limit nut are engaged.

The retaining nut of the limit setting member 36 and the engaging nut of the limit setting member 36' have the same shape, and the groove S' is formed so that the actuator operates in the opposite direction so that the limit nut 32
This is a groove into which the claw l' of the clamper 29 is fitted when the clamper 29 engages with the limit setting member 36'.

In this way, the limit nut 32 is a member that detects the operating position of the actuator, and when it moves to a preset position, it engages with the limit setting member 36 or 36' and rotates to apply a torque to the limit striker 35. It is rotated by a certain amount around the shaft 20.

When the limit striker 35 rotates by a certain amount, either one of the limit control elements is actuated by the limit striker, as shown in FIG.

FIG. 11 shows the state when the valve is driven to the closed position.

When the valve starts to operate in the opposite direction after reaching the closed position and stopping, the claw l of the clamper 31 enters the groove m of the engagement nut and the limit shaft 7 and the limit nut 32 are connected to each other, as shown in FIG. Because it is in a state where it is combined,
There is no possibility that the limit nut will be left behind and only the limit shaft will rotate.

When the rod-shaped end of the limit striker 35 fits into the groove k of the limit nut again and returns to the neutral position, the clamper 29 is pressed by the rod-shaped end of the limit striker 35, so that the claw l of the clamper moves into the groove k of the engagement nut. It deviates from the

Therefore, the connection between the limit shaft and the limit nut is released, and the limit nut moves linearly in the axial direction by rotation of the limit shaft and engages with the limit setting member on the opposite side.

When the actuator operates to its limit position and then stops, the movement of the limit striker 35 is detected to indicate which limit position it has reached.

That is, in FIG. 1, 39 is an indicator scale plate, and a pointer 40 and a connecting piece 41 are fixed to a shaft 42.

The shaft 42 is rotatably supported by the limit shaft 7 and the indicator scale plate 39.

One end of the limit striker 35 is shown in Fig. 12 (F in Fig. 1).
-F' section viewed from the right side), the connecting piece 4
It is engaged with the groove t of No. 1.

Therefore, when the limit striker 35 rotates, the coupling piece 41 and the pointer 40 are pressed by it and rotate about the shaft 42, thereby indicating the direction of the stop position of the actuator.

The example shown in FIG. 13 is a case where the actuator is used to drive a valve, and the pointer 40 indicates the operating state of "SHUT" when the valve is closed and "OPEN" when the valve is opened.

Figure 13 shows the torque striker 27 when the valve is closed.
When the valve hits the valve seat in the closed position and the output torque of the actuator increases, the torque shaft 20 rotates clockwise, and as mentioned above, the torque setting piece adjusts the protrusion of the torque striker 27. Part j is pressed,
The control element 28 is actuated by the projection i.

Actuation of this control element 28' causes the actuator to stop.

At this time, the limit striker 35 rides on the circumferential end of the limit nut 32, as described above, and rotates a certain amount clockwise.

43 is a blocking member screwed into the torque striker 27, and when the torque striker 27 is in the neutral position, it is located outside the rotation orbit of the limit striker, and the torque striker 27 is rotated counterclockwise to control it. Element 2
The limit striker 35 is arranged so as to move within the clockwise rotational trajectory of the limit striker 35 when the limit striker 35 reaches the operating position No. 8.

FIG. 13 is a diagram illustrating the function of this blocking member 43.

After the valve is driven to the closed position and the actuator stops, when starting to drive the valve to the open position, the actuator generates a fairly large starting torque due to the valve's inertia or hydraulic pressure. If the torque is larger than the setting value of the torque control mechanism, the torque striker will actuate the control element 28 and stop the actuator if the blocking member 43 is not provided.

When the blocking member 43 is attached to the above-mentioned position,
As shown in FIG. 14, when the torque striker 27 rotates counterclockwise due to the initial torque, the blocking member 43 hits the limit striker 35, thereby preventing the torque striker 27 from rotating to the control element operating position. .

Note that even if the torque striker 27 is prevented from rotating at this time, the force applied thereto is only the elastic force of the spring 16 of the linear displacement/rotational displacement conversion mechanism shown in FIG. There is no risk of damage.

That is, when the valve is driven toward the open position, the excessive output of the actuator causes the torque push rod to be displaced to the left in FIG. Since the displacement per rotation is converted, even if the rotation of the torque striker 27 is blocked by the blocking member 43, the torque push rod only moves to the left, and no excessive force is applied to the control mechanism. I can't tell you.

Since the limit striker has returned to the neutral position while the valve is being driven in the opening direction, the torque striker can rotate in response to excessive output caused by an accident, etc., and actuate the control element 23. .

In the figure, 44 is an engagement member screwed into the limit striker 27, and is arranged so as to be located on the rotational trajectory of the limit striker 35 when the torque striker is in the neutral position.

Next, the function of this engaging member 44 will be explained.

When the valve is driven toward the open position, the limit nut 32 moves linearly to the right in FIG. Rotate in the opposite direction.

This state is shown in FIG.

As shown in the figure, the limit striker 35 rides on the peripheral end surface of the limit nut 32 and rotates a certain amount counterclockwise about the torque shaft 20.

At this time, the engaging member 44 engages this limit striker 35.
Since the engaging member 44 is pressed by the limit striker 35, the torque striker rotates counterclockwise, actuating the control element 28, and stopping the drive of the actuator. .

When the valve starts to be driven again from the open position toward the closed position, an excessive starting torque is generated in the actuator, but in this case, since the engaging member 44 is in contact with the limit striker 35, the torque striker 27 is prevented from rotating in the opposite direction and activating the control element 28.

In this case, the excessive output occurs while driving the valve toward the closed position, so the torque push rod 8' is displaced to the right in FIG. Torque coupler 2 through 20
1.

However, the torque coupler 21 and the torque setting plate 23 are not directly connected, and the protrusion f of the torque setting plate is connected to the spring 2.
Since the torque is applied by pressing the notched end e of the torque coupler 2 with the torque coupler 2, only the torque coupler 21 rotates and no excessive force is transmitted to the torque striker, as shown in FIG. , there is no risk of damage to the control mechanism.

In the above embodiment, taking the case of opening and closing a valve as an example, when the actuator is driven toward the valve closing position, the actuator control mechanism due to excessive output stops the driving source, and the actuator is driven toward the valve opening position. Although the case has been described in which the drive source is stopped by the actuator control mechanism depending on the operating position when being driven, the torque striker 27 may be provided with a blocking member and an engaging member in both rotational directions of the limit striker 35, respectively. Since the female threaded hole is provided, various control methods can be implemented depending on the drive mode of the operated object by selectively attaching the blocking member and the engaging member to the torque striker 27.

As described above, according to the present invention, the extremely simple configuration in which the engaging member and the blocking member are selectively attached to specific positions on the torque striker 27 allows the actuator control mechanism and excessive output to be controlled depending on the operating position. The control mechanism of the actuator can be operated in conjunction with the control mechanism of the actuator, and the function of preventing malfunction of the control mechanism due to excessive output at the time of starting can be provided.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIG. 2 is a cross-sectional view of a linear displacement/one-rotation displacement converter, FIG. 3 is a side view of the link plate 17, and FIG. 4 is an A of FIG. 1. -A' sectional view, 5th
The figure is a BB' sectional view of FIG. 1, FIG. 6 is a BB' sectional view in an operating state, and FIG. 7 is a perspective view of the clamper 29.
Fig. 8 is a cross-sectional view of CC' in Fig. 1, and Fig. 9 is a cross-sectional view of D--D in Fig. 1.
D' sectional view, FIG. 10 is a sectional view of the main part of D-D' in the operating state, FIG. 11 is a sectional view of the main part of C-C' in the operating state, and FIG. 12 is the main part of F-F' in FIG. 13, FIG. 14, and FIG. 15 are sectional views of main parts taken along the line EE' in the operating state, and FIG. 16 is a sectional view of the main parts taken along the line AA' in the operating state. 1... Actuator power source, 2... Output worm shaft,
3... Worm wheel, 4... Main shaft, 5... Worm for position detection, 6... Worm wheel for position detection, 7...
...Limit shaft, 8...Torque push rod, 9
...Mounting base plate, 10...Lever base, 15...
Lever, 17...Link plate, 16...Coupler, 19...Coupling pin, 20...Torque shaft, 21
... Torque coupler, 23 ... Torque setting plate, 24,
24'... Torque adjustment screw, 26, 26'... Torque setting piece, 27... Control element drive member, 28, 28'... Control element, 29... Clamper, 32... Limit nut, 35... Limit Striker, 36, 36'... Limit setting member, 37, 37'... Limit control element, 4
3... Blocking member, 44... Engaging member.

Claims (1)

[Claims] 1. Normally, the actuator is resiliently held in a neutral position and operates reciprocatingly. When the operating torque exceeds a preset value, the actuator rotates in either direction around the rotation axis depending on the actuator's operating direction. A cylindrical torque striker, a pair of control elements that operate when the torque striker or a member that rotates integrally with the torque striker is engaged with the torque striker when the torque striker rotates in either direction, and a control element that is normally neutral. position, and when the actuator operates beyond a predetermined extreme position, the cylinder has a cylindrical shape that rotates in either direction depending on the operating direction of the actuator around a support shaft installed parallel to the fore-fertilization rotation axis. a limit actuating body which is removably engaged with the limit actuating body and is rotatable in any direction about the rotational axis of the torque striker depending on the operating direction of the actuator; A lever-shaped limit strike force that rotates so that it is released from the limit actuating body when the torque striker rotates, and a limit striker that is detachably attached to the outer circumferential surface of the torque striker and when the torque striker is in the neutral position. a retaining member that is mounted so as to be positioned on the rotational trajectory of the torque striker and that engages with the limit striker when the limit striker rotates to rotate the torque striker to a control element operating position; When the torque striker is in a neutral position, the torque striker is mounted so as to be located outside the rotational trajectory of the limit striker, and when the torque striker rotates in a certain direction to actuate the control element and rotates in the opposite direction. A blocker that engages with a limit striker that is detached from the limit actuating body due to rotation and whose rotation in the opposite direction is prevented by the limit actuator, thereby preventing rotation of the torque striker in the opposite direction. When the engaging member is attached, the control element is operated by the rotation of the limit striker, and when the blocking member is attached, the actuator is operated beyond the limit position and the limit actuating body is rotated. When the limit striker is rotated in the direction in which the limit striker is separated from the limit actuating body and the limiting element is operated, the torque striker is prevented from rotating in the opposite direction and reaching the operating position of the other side control element. Characteristic actuator control mechanism.