JP4749811B2 - Spring return type rotary actuator - Google Patents

Description

  The present invention relates to a spring return type rotary actuator, and more particularly to improvement of an actuator used for a rotary valve such as a ball valve or a butterfly valve.

Conventionally, this type of spring return type rotary actuator has a cylinder and a spring device arranged in series, and is actuated by fluid pressure of air, oil, etc. into the cylinder in one direction, and the spring device in the other direction. It can be operated by the elastic repulsive force of the spring. The spring in the spring device is housed in a contracted state against the elastic force.
As such a rotary actuator, for example, as in the conventional examples of FIGS. 8 to 10 in Patent Document 1, a spring is stored in a casing in a compressed state, and the covered portions on both sides of the casing are rods called tie rods. Is fixed by tightening with a nut or the like in a state of being provided outside the casing. In this case, the tie rod is formed shorter than the maximum extension length of the spring, and the tie rod is housed in the spring device while the elastic repulsion force of the spring is maintained by tightening and fixing the tie rod.

For this reason, when disassembling this actuator for maintenance, etc., when the tie rod is removed, the cover part holding the spring by the elastic repulsive force of the spring is blown or the spring pops out and the operator is injured. There is a risk of damage to the instrument.
In order to prevent this, the cylinder type actuator disclosed in Patent Document 1 is formed by screwing a screw and a female screw so that the rod has a long screw-in length, and the spring is already free when the screw is loosened until the screw is released. It is configured to be extended to a long length. This prevents the spring's elastic repulsion from remaining when the rod is loosened when the spring device is disassembled, thereby preventing the spring from jumping out.

In addition, although the rotary actuator of Patent Document 2 is not shown, the spring part and the cylinder part are fixed by a tie rod provided outside the spring part, and the spring part is a cartridge type so that the spring part is a cylinder part. It can be installed and removed from Thereby, when the spring part is removed from the cylinder part, the spring is prevented from jumping out from the spring part.
Japanese Utility Model Publication 3-31842 JP-A-5-52205

  However, since the actuators of Patent Document 1 and Patent Document 2 are both attached to the outside of the actuator, the tie rod can be easily loosened or tightened. There is a problem in safety because the screwed part may be loosened naturally due to removal, contact from the outside, or intentional removal due to mischief or the like. If the spring part is removed from the cylinder part, the spring return function by the spring part does not work, so this must be prevented.

Furthermore, since the cylinder type actuator of Patent Document 1 has a structure in which the cylinder and the spring device are integrated, there is a problem that assembly and disassembly are complicated and maintenance is troublesome.
On the other hand, the rotary actuator of Patent Document 2 makes it possible to disassemble the spring part and the cylinder part by making the spring part a cartridge type, which makes maintenance easier, but the tie rod is attached to the outside of the spring cartridge. The above-mentioned problem of being left was left.

  The present invention has been developed in view of the conventional problems, and an object of the present invention is an actuator that can easily perform maintenance and the like by preventing springs and parts from popping out during disassembly. It is an object of the present invention to provide a spring return type rotary actuator that can exhibit high safety by preventing the tie rod from being removed from the outside, and can be easily disassembled and assembled.

In order to achieve the above object, according to a first aspect of the present invention, there is provided a conversion mechanism in which a spring cartridge is provided in a cylinder device that houses a piston rod, and the movement of the piston rod is housed in the cylinder device. In the spring return type rotary actuator that is converted into a rotational motion by the tie rod disposed inside the spring cartridge portion, the spring cartridge portion is configured, and the connecting portion of the tie rod on the cylinder device side is the inside of the cylinder device. The one end of the spring on the cylinder device side is attached to a retainer housed in the spring cartridge part, and the end of the piston rod is inserted into the retainer, and the tie rod is inserted into the retainer. Let this guide hole form The tie rod and the retainer are formed in a substantially arcuate shape along the wellbore in the winding direction of the spring is a spring return rotary actuator so as not to interfere.

  In the invention according to claim 2, the spring cartridge portion is assembled by a spring case housing the spring, a spring cover provided at both ends and a fixing flange, and both ends of the tie rod provided in the spring case are connected to the spring cover and the fixing flange. This is a spring return type rotary actuator which is fixed and constitutes a spring cartridge part.

  According to a third aspect of the present invention, the cylinder device is a spring return type rotary actuator comprising a case body housing the conversion mechanism and a cylinder portion, and the case body is provided with a mounting flange to be attached to a fixed flange of the spring cartridge portion. .

According to the first aspect of the invention, the actuator can prevent the springs and parts from popping out at the time of disassembly, and can easily perform maintenance and the like without causing the operator to get injured or damage the instrument. This is a spring return type rotary actuator that prevents the tie rod from being removed from the outside and can exhibit high safety.
At the time of maintenance, the cartridge-type spring cartridge can be freely detached from the cylinder device or assembled, and when these are separated, the connection portion of the tie rod can be exposed to the outside for easy maintenance . In addition, the rotational force when the rotational force is applied to the retainer as the spring is compressed or extended can be released, and the retainer and the tie rod do not interfere with each other. The return force by the spring can be reliably transmitted without being dispersed.

According to the invention of claim 2, by disposing the tie rod in the spring cartridge, it is possible to prevent the spring cartridge from being disassembled at normal times. On the other hand, at the time of maintenance, etc., the spring cartridge can be easily removed and the internal parts can be easily removed. Can be inspected and replaced .

According to the invention of claim 3, the cylinder device and the spring cartridge can be easily assembled, and when disassembling, the tool can be easily disassembled while preventing the springs and parts from popping out, and maintenance can be performed. Can be done .

One embodiment of the spring return type rotary actuator in the present invention and its operation will be described with reference to the drawings.
1 to 3, the rotary actuator main body 1 is configured by providing a spring cartridge portion 30 to a cylinder device 10.
The cylinder device 10 includes a case main body 11 and a cylinder portion 12.
The case main body 11 is provided with a mounting flange 11a, and the mounting flange 11a is provided so as to be attachable to a fixed flange 35 formed in the spring cartridge portion 30. A conversion mechanism 15 having a scotch yoke 14 is housed in the case main body 11, and the reciprocating motion of the piston rod 13 is converted into rotational motion of the output shaft 16 by the conversion mechanism 15. The piston rod 13 starts moving forward when air, oil, or the like is supplied from a supply port (not shown) formed in the cylinder portion 12.

  In addition to the mechanism using the scotch yoke 14, the conversion mechanism 15 may use a mechanism using a rack and pinion (not shown), or another conversion mechanism such as a gear mechanism, and is a spring return type rotary actuator. If it exists, it can be set as the cylinder apparatus 10 of various conversion mechanisms 15. FIG.

  In the figure, the housing part of the cylinder portion 12 has a cylinder cylinder 12a, a lid 12b, and a cylinder cover 17, and the housing part and the case body 11 are connected to constitute the housing part of the cylinder device 10. Yes.

The cylinder cover 17 is attached to the end of the cylinder cylinder 12a via an O-ring 40, and a stopper bolt 18 is screwed to the screw 17a via a male screw 18a to be provided on the cylinder cover 17. A nut 19 is screwed onto the male screw 18a, whereby the stopper bolt 18 is positioned and fixed. When the piston rod 13 is reciprocated, a stopper bolt 18 is provided so as to be in contact with the tip portion 13 a of the piston rod 13.
The cylinder cover 17 is fixed to a fixing portion 11b which is a female screw of the case main body 11 with a mounting bolt 20 and a mounting nut 21 with the cylinder cylinder 12a interposed therebetween. The O-ring 41 is mounted on the outer peripheral edge side of the piston member 13b that slides in the cylinder cylinder 12a, and seals between the piston member 13b and the cylinder cylinder 11a. The O-rings 42 and 43 are attached to the lid body 12b, and seal the lid body 12b, the cylinder cylinder 12a, and the case body 11.

  The spring cartridge portion 30 houses a coiled spring 32 in a spring case 31 formed in a pipe shape, and this spring 32 is in a state where one end side is in contact with a retainer 34 that is a portion that presses the piston rod 13. The other end side is housed while being in contact with the inner end portion of the spring cover 33 connected so as to close the spring case 31. The retainer 34 receives one end of the spring 32, and is elastically applied to the piston rod 13 between the attachment side of the spring cover 33 and the fixed flange 35 provided on the other end by the elastic force of the spring 32. Are connected. As described above, the spring cartridge portion 30 is assembled by the spring cover 33 and the fixing flange 35 provided on both sides, and the spring cover 33 and the fixing flange 35 are respectively mounted with O-rings 44 and 45 between the spring case 31. It is installed in the state.

Female threaded portions 33a are provided at a plurality of locations inside the spring cover 33, and a male threaded portion 36a of a tie rod 36 formed in a rod shape is screwed to the female threaded portion 33a. Further, a male screw portion 36b is provided on the other end side of the tie rod 36, and a female screw portion 37a of a fixing nut 37, which is a fastening portion, is screwed to the male screw portion 36b. The fixing nut 37 has a special shape that can be fastened by a special tool (not shown), and is formed in a state that is difficult to loosen with a normal tool. The fixing nut 37 may be fixed by welding means such as spot welding.
A female thread 33b is provided at the center of the spring cover 33, and the male thread 46a of the stopper bolt 46 is screwed onto the female thread 33b and is fastened and fixed by a nut 47 .

The tie rod 36 is inserted into a guide hole 34 a provided through the retainer 34, and further, the fixing nut 37 is inserted from the outside of the fixing flange 35 in a state of being inserted into a through hole 35 a formed in the fixing flange 35. The fixing flange 35, the spring case 31, and the spring cover 33 are integrally connected by screwing. Thus, both ends of the tie rod 36 provided in the spring case 31 are fastened to the spring cover 33 and the fixing flange 35 to constitute the spring cartridge portion 30, and the spring cartridge 32 is maintained in a state in which the resilience of the spring 32 is maintained. The spring 32 is provided so that the piston rod 13 of the cylinder device 10 can be moved twice.
As described above, the spring cartridge portion 30 is configured by the tie rod 36 disposed inside, and the fixing nut 37 that is a connecting portion of the tie rod 36 on the cylinder device 10 side is disposed inside the cylinder device 10. Therefore, the fixing nut 37 can be loosened or tightened only when the spring cartridge portion 30 is separated from the cylinder device 10.

Therefore, the spring cartridge portion 30 is arranged by connecting the fixing nut 37 which is a connection portion inside the cylinder device 10, so that it is accidentally removed when the actuator body 1 is disassembled, or due to external contact or vibration. It is possible to prevent the screwed portion from being loosened naturally or removed by mischief.
Furthermore, since the tie rod 36 is provided inside the spring case 31, damage and contamination of the tie rod 36 can be prevented, and the actuator body 1 can be easily painted. Further, since the tie rod 36 hardly corrodes, it is not necessary to use an expensive material such as SUS, and the tie rod 36 can be provided using a low-cost material.
Further, when the actuator body 1 is disassembled, the tie rod 36 does not get in the way, so that the disassembling work can be facilitated. Furthermore, since the whole can be reduced in size, the actuator main body 1 can be installed in a narrow space.

  The spring 32 may be provided with an annular thrust bearing plate made of PTFE (not shown) having a low frictional resistance on at least one of both end sides, and both ends generated when the spring 32 is compressed and extended. The relative rotational movement between the surfaces can be performed smoothly without difficulty.

The retainer 34 is provided with a taper-shaped alignment portion 38, while the fixed flange 35 is formed with a taper guide portion 39 into which the alignment portion 38 can be fitted.
The taper angle θ of the aligning portion 38 and the taper guide portion 39 is formed at about 45 ° as shown in FIG. 4, and the aligning portion 38 is provided so as to be able to smoothly guide the taper guide portion 39. Yes.
In a state where the spring cartridge portion 30 is removed, the retainer 34 moves to the fixed flange 35 side by the elastic force of the spring 32. At this time, the alignment portion 38 is guided to the taper guide portion 39 as shown in FIG. These are fitted so that the retainer 34 can be aligned.
In this way, the retainer 34 is always adjusted to be aligned in the elastic state, and when the spring cartridge unit 30 and the cylinder device 10 are assembled, the fixing flange 35 of the spring cartridge unit 30 and the mounting flange of the cylinder device 10 are assembled. It is possible to assemble the piston rod 13 while securely inserting the tip end side of the piston rod 13 into the insertion hole 34b for inserting the piston rod 13 formed in the aligned retainer 34 simply by superimposing 11a at the assembly position. . Further, even when the retainer 34 is displaced due to the rotational force of the spring 32, it can be returned to an accurate position while correcting the displacement.

In the spring cartridge portion 30 and the cylinder device 10, in a state where the fixing flange 35 and the mounting flange 11 a are combined , a fixing bolt 25 as a fixing member is inserted into a through hole (not shown) formed in the fixing flange portion 35. Are screwed into a mounting hole (not shown) formed in the mounting flange 11a so that they are fixed together. In this way, the cylinder device 10 and the spring cartridge portion 30 are fixed by the fixing bolt 25, so that the cylinder device 10 and the spring cartridge portion 30 have no means for separating them other than removing the fixing member 25, When separated, the connection portion 37 of the tie rod 36 is exposed.

  The spring cartridge unit 30 is attached to the cylinder device 10 in an independent state as a cartridge. When the fixing member 25 is removed, the spring 32 does not pop out, and the operator may be injured or the instrument may be damaged. Without being separated from the cylinder device 10. In the present embodiment, the spring cartridge unit 30 and the cylinder device 10 are fixed by the fixing bolt 25, but may be fixed by using fixing means other than the fixing bolt 25.

  As shown in FIG. 6, the guide hole 34 a of the retainer 34 is formed in a substantially arc shape along the winding direction of the spring 32, whereby rotational force is applied to the retainer 34 as the spring 32 is compressed and extended. The rotational force at the time of applying can be released, and the retainer 34 and the tie rod 36 do not interfere with each other. Therefore, the elastic force of the spring 32 can be applied to the retainer 34 without decentering, and the return force by the spring 32 can be reliably transmitted without being dispersed.

When assembling the spring cartridge portion 30, the spring cover 33 is mounted in the spring cover 33 in the order of the spring 32, the retainer 34, and the fixing flange 35 while the spring cover 33 is positioned below, and is not shown from the outside of the fixing flange 35. The insertion portion 35b formed on the fixed flange 35 is inserted into the inside of the spring case 31 by pressing with an appropriate press machine, and in this state, the tie rod 36 is screwed onto the female screw portion 33a of the spring cover 33 as described above. Further, the fixing nut 37 is screwed onto the male screw portion 36b of the tie rod 36 for assembly.
At this time, the spring case 31, the spring cover 33, and the fixing flange 35 are firmly sealed, and the O-ring 44 and the O-ring 45 are not cut.

On the other hand, when decomposing the spring cartridge 30, the stopper bolt 46 Remove nuts 47, sampling the stopper bolt 46 from the spring cover 33, and then, the mounting position of the stopper bolt 46 of the total length of the spring cartridge 30 length A longer bolt (not shown) is inserted, and a nut (not shown) is screwed onto the distal end of the long bolt with the through-hole 35a of the fixing flange 35 being passed through to maintain the spring cartridge portion 30 in the length direction. While fixing. Next, after removing the tie rod 36, the spring cartridge portion 30 can be disassembled by gradually loosening the nut of the long bolt. As described above, on-site assembly and disassembly at the actuator installation location are possible.
Since the spring cartridge portion 30 is of a cartridge type, it can be easily detached from the cylinder device 10 and can be easily assembled and disassembled. In addition, since the number of parts is small, the spring return type rotary actuator can be provided which is inexpensive, facilitates piping work, and is easy to operate.

During the operation of the actuator, normally, a power source such as air pressure or hydraulic pressure is supplied into the cylinder portion 12, and the piston rod 13 moves in the direction in which the piston member 13b is pressed. When the supply of a power source such as air pressure or hydraulic pressure is lost, the retainer 34 is pressed by the elastic force of the spring 32 of the spring cartridge portion 30, and the piston rod 13 is pushed by the retainer 34 to be moved backward. Such a reciprocating motion of the piston rod 13 is converted into a rotational motion of the output shaft 16 by a conversion mechanism 15 that converts the reciprocating motion built in the case main body 11 into a rotational motion, and a rotary valve such as a ball valve (not shown) is used. The stem is provided so that it can be rotated.

During this operation, the tip end portion 13a of the piston rod 13 abuts against the stopper bolt 18, while the rear end side of the piston rod 13 abuts against the stopper bolt 46. Therefore, the amount of the stopper bolts 18 and 46 inserted is adjusted. While positioning and fixing, the amount of movement of the piston rod 13 during reciprocation can be adjusted, the amount of rotation of the output shaft 16 at the valve opening / closing position can be limited, and the valve can be opened and closed accurately.

In the present embodiment, four tie rods 36 are mounted, but this number can be changed as appropriate. The spring case 31, the fixing flange 35, and the spring cover 33 may be welded respectively.
The taper angle θ between the aligning portion 38 and the taper guide portion 39 is 45 °. However, when the retainer 34 moves to the fixed flange 35 side by the elastic force of the spring 32, the aligning portion 38 becomes the taper guide portion 39. The angle is not limited as long as the angle can be naturally guided and fitted, and for example, it can be provided at an arbitrary angle of 45 ° or more. Further, although the convex alignment portion is provided on the retainer 34 side and the concave taper guide portion is provided on the fixed flange 35 side, they may be provided on the contrary.

1 is a partially cutaway perspective view showing an embodiment of a spring return type rotary actuator according to the present invention. It is a cross-sectional view of FIG. FIG. 3 is a cross-sectional view of FIG. 2. It is a partially expanded sectional view of FIG. It is sectional drawing which showed the state which the piston rod of FIG. 4 act | operated. It is a front view of a retainer.

DESCRIPTION OF SYMBOLS 1 Actuator main body 10 Cylinder apparatus 11 Case main body 11a Mounting flange 12 Cylinder part 13 Piston rod 15 Conversion mechanism 30 Spring cartridge part 31 Spring case 32 Spring 33 Spring cover 34 Retainer 35 Fixing flange 36 Tie rod 38 Centering part 39 Taper guide part

Claims (3)

In a spring return type rotary actuator in which a spring cartridge part having a built-in spring is provided in a cylinder device that houses a piston rod, and the movement of the piston rod is converted into rotational movement by a conversion mechanism built in the cylinder device. A tie rod disposed inside the spring cartridge portion constitutes a spring cartridge portion, a connecting portion of the tie rod on the cylinder device side is disposed inside the cylinder device, and one end portion of the spring on the cylinder device side is disposed. The retainer housed in the spring cartridge portion is mounted, the end of the piston rod is inserted into the retainer, a guide hole is formed through which the tie rod is inserted, and the guide hole is formed in the winding direction of the spring. Roughly arc along Spring return rotary actuator, wherein the retainer and the tie rod is prevented from interfering with formed.   The spring cartridge part is assembled by a spring case housing the spring, a spring cover provided at both ends, and a fixing flange, and both ends of a tie rod provided in the spring case are fixed to the spring cover and the fixing flange. 2. The spring return type rotary actuator according to claim 1, wherein the spring cartridge part is constituted.   3. The spring return type rotary according to claim 1, wherein the cylinder device includes a case main body and a cylinder portion that house the conversion mechanism, and the case main body is provided with a mounting flange that is attached to a fixed flange of the spring cartridge portion. Actuator.

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