JP2004308870A - Operation range setting mechanism for actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an operation range setting mechanism for an actuator having the relatively simple structure with a small number of parts items and to be fitted with one operation without using a tool and allowing to remove and to change the operation range. <P>SOLUTION: This operation range setting mechanism 30 is formed of a cam holder 36 to be fitted to an output shaft 26 of the actuator 26, a cam 37, a scale board 38, a closing switch 40 and an opening switch 41 arranged in a fitting plate 39 opposite to each other through the cam 37. The cam holder 36 and the cam 37 are turnably and disconnectably connected to each other by a snap-fit mechanism 46 formed of an engagement piece 45 and an engagement hole 46. Furthermore, the cam 37 is connected to the cam holder 36 freely to adjust angle thereof by a tilt mechanism 66 formed by engaging projecting bodies 54 and 64, which have a triangle cross section and radially formed in the peripheral part of a surface of a flange part of the cam holder 36 and the peripheral part of a lower surface of the cam 37, with each other. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an operation range setting mechanism of an actuator used for an electric valve or the like that controls a flow rate of a fluid such as hot water, cold water, steam, or the like flowing in a pipe of an air conditioner in a building.
[0002]
[Prior art]
Electric actuators that adjust the opening of valves such as butterfly valves and ball valves that control the flow rate of fluids such as hot water, cold water, and steam flowing in the piping of air conditioning equipment in the building are driven by drive signals from the control unit. A drive motor to be driven, an output shaft rotated by the drive motor, and an operation range setting mechanism for setting an operation range (rotation angle) of the output shaft, and transmitting rotation of the output shaft to a valve shaft. Is configured to control the opening and closing of the motor-operated valve.
[0003]
The actuator operation range setting mechanism is used to stop the opening and closing operation of the valve so that it does not open and close excessively when the electric valve is fully closed, fully opened, or at an arbitrary opening position. The drive valve is fully closed, fully open, or held at a predetermined opening position by closing and opening the valve drive control circuit of the actuator by turning on and off the limit switch by the cam. (For example, see Patent Documents 1, 2, and 3). The applicant could not find prior art documents closely related to the present invention by the time of filing, except for the prior art documents specified in the prior art document information described in the present specification.
[0004]
[Patent Document 1]
JP-A-8-21555
[Patent Document 2]
JP 2000-104848 A
[Patent Document 3]
JP-A-11-44379
[0005]
The valve actuator described in Japanese Patent Application Laid-Open No. H8-21555 is configured to change the operation range of the actuator by changing the switch on / off timing by a cam by changing the position of a limit switch. It is. Specifically, the rotation of the drive shaft of the drive motor is sequentially transmitted to the main output shaft and the sub output shaft via a gear train, and two stopper cams are fixed to the sub output shaft. A rotatable moving mechanism is provided, and a limit switch that is turned on and off by each stopper cam is attached to the moving mechanism. In changing the operation range, the moving mechanism is rotated to change the mounting position of the limit switch with respect to the stopper cam.
[0006]
On the other hand, there is also known an operation range setting mechanism in which a switch is fixedly arranged with respect to a cam and an operation range of an actuator is changed by adjusting a mounting angle of the cam with respect to an output shaft.
[0007]
FIGS. 18A and 18B show a conventional example of an operation range setting mechanism in which the mounting angle of a cam is adjusted. In the drawing, the reference numeral 1 designates an entire operation range setting mechanism for an actuator. The operation range setting mechanism 1 is capable of changing a fully closed angle (−45 °) and a fully open angle (45 °) of a drive valve and a full operation. The figure shows a fixed angle (90 °) type operation mechanism in which the variable range of the fully closed and fully opened angles is ± 5 °. 2 is an output shaft of the actuator, 3 is a base plate fixed to the end face of the output shaft 2, 4 is a cam attached to the base plate 3 by a set screw 5, and 6 and 7 are plates 8 opposed to each other with the cam 4 interposed therebetween. And a closed switch and an open switch which are fixed to the switch. The cam 4 is attached to the base plate 3 so as to be adjustable in an angle range of ± 5 ° by a long hole 9 and a set screw 10 which are long in the circumferential direction.
[0008]
FIG. 18A shows the positional relationship between the cam 4, the closing switch 6, and the opening switch 7 at the time of the intermediate opening when the full closing angle of the drive valve is set to −45 ° and the full opening angle is set to 45 °. Is shown. In this state, the rollers 11 and 12 of the closing switch 6 and the opening switch 7 ride on the large-diameter portion 4a of the cam 4 and hold these switches 6 and 7 in the ON state. In FIG. 2B, the set screw 10 is loosened and the cam 4 is rotated in the opening direction (counterclockwise) by a maximum angle (+ 5 °) to change the drive valve to a full closing angle of −50 ° and a full opening angle of 40 °. 3 shows the positional relationship between the cam 4 and the close-side switch 6 and the open-side switch 7 at the time of the intermediate opening in the case. When the cam 4 is rotated in the closing direction (clockwise) by the maximum angle (−5 °), the drive valve can be changed to a fully closed angle of −40 ° and a fully open angle of 50 °.
[0009]
[Problems to be solved by the invention]
The valve actuator described in Japanese Patent Application Laid-Open No. H8-21555 has a problem that the number of components constituting the operation range setting mechanism is large, and the mechanism is complicated and expensive. In particular, since the rotation of the drive shaft of the drive motor is transmitted to the main output shaft and the sub-output shaft via a gear train, many gears are required, and these backlashes affect the angle setting and have high precision. Angle setting is difficult. Also, the mounting and dismounting operations and the operation of changing the operation range are cumbersome and require a long time. Further, there are many problems such as a need to secure a space around the cam for rotating the moving mechanism.
[0010]
In the operation range setting mechanism 1 shown in FIG. 18, when changing the operation range, the operator rotates and adjusts the cam plate 4 within the range of the long hole 9 by eye examination. When the angle is adjusted to a desired angle smaller than (± 5 °), it is difficult to accurately confirm the number of rotations. Further, when changing the operation range, it is necessary to loosen the set screw 10 with a tool such as a screwdriver to perform adjustment.
[0011]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has as its object a relatively simple structure with a small number of parts, one-touch mounting without any tools, removal work and operation. An object of the present invention is to provide an operation range setting mechanism of an actuator capable of performing a range changing operation.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a first aspect of the present invention is an operation range setting mechanism for setting an operation range of an output shaft of an actuator, wherein a cam holder attached to the output shaft, a cam attached to the cam holder, A pair of switches that are fixedly disposed so as to face each other and are turned on and off by the cam, respectively, and a scale plate attached to the cam holder and displaying an opening scale corresponding to an operation angle of the output shaft, By connecting the cam holder and the cam with a snap-fit mechanism and a tilt mechanism, the cam can be changed in angle by a predetermined angle with respect to the cam holder.
[0013]
According to a second aspect of the present invention, in an operation range setting mechanism for setting an operation range of an output shaft of an actuator, a cam holder mounted on the output shaft, a cam mounted on the cam holder, and fixedly arranged so as to face each other via the cam. A pair of switches each turned on and off by the cam, and a scale plate attached to the cam holder and displaying an opening scale corresponding to the operating angle of the output shaft, wherein the cam holder is attached to the output shaft. The cam is formed into a ring shape which is fitted to the outer periphery of the cylindrical portion of the cam holder, and the cam is formed on a part of the outer peripheral surface. A protrusion for turning on and off each of the switches is integrally protruded, and the flange of the cam holder and the cam are snap-fitted with an engagement piece and a long hole into which the engagement piece is engaged. The cam holder is detachably and rotatably connected by a mechanism, and the cam is held by the cam holder by a tilt mechanism formed by a plurality of ridges formed radially on surfaces of the flange portion and the cam that are in close contact with each other and meshing with each other. Are connected so that the angle can be changed by a certain angle.
[0014]
According to a third aspect of the present invention, in an operation range setting mechanism for setting an operation range of an output shaft of an actuator, a cam holder attached to the output shaft, first and second cams attached to the cam holder, and via these cams. First and second switches which are fixedly arranged so as to face each other and are turned on and off by corresponding cams, respectively, and a scale plate attached to the cam holder and displaying an opening degree scale corresponding to an operation angle of the output shaft. Wherein the cam holder comprises a cylindrical portion fitted to the output shaft, and a flange integrally provided on the outer periphery of the cylindrical portion, and the first and second cams are formed by a cylinder of the cam holder. A protrusion for turning on and off the first and second switches is integrally formed on a part of the outer peripheral surface so as to be fitted to the outer periphery of the outer periphery of the flange. The second , The second cam is detachably and rotatably coupled by a snap-fit mechanism including an engagement piece and an elongated hole into which the engagement piece is engaged, and the flange is connected to the first and second flanges. The first and second cams are connected to the cam holder so as to be able to change the angle by a predetermined angle by a tilt mechanism formed by a plurality of ridges formed radially on the surfaces of the cams which are in close contact with each other and meshing with each other. Things.
[0015]
In the first, second, and third inventions, since the cam holder and the cam are connected by the snap-fit mechanism, a screw for fixing the cam to the cam holder is not required, and the cam can be attached or detached with one touch. it can.
In the second and third inventions, since the tilt mechanism is constituted by the ridges that mesh with each other, when the cam is rotated to change the meshing state of the ridges, the width (pitch) of the ridges is reduced. The operation range can be changed by a corresponding angle.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings.
FIG. 1 is a front view of a valve provided with an actuator according to the present invention, FIG. 2 is an exploded perspective view showing an embodiment of an operation range setting mechanism of the actuator, FIG. 3 is a front view of a cam holder, and FIG. 5, FIG. 5 is a bottom view of the same cam holder, FIG. 6 is a sectional view taken along the line VI-VI of FIG. 4, and FIG. 8 is a plan view of the cam, FIG. 9 is a side view of the cam, FIG. 10 is a bottom view of the cam, FIG. 11 is an enlarged view of FIG. 8 as viewed from the direction of the arrow B, and FIG. FIG. 13 is a graph showing the relationship between the angle and the lift amount of the valve shaft, FIG. 13 is a graph showing the relationship between the operation angle of the output shaft and the lift amount of the valve shaft, and FIGS. FIG. In this embodiment, an example will be described in which the present invention is applied to an actuator used for an electric drive valve that controls a flow rate of a fluid flowing in a pipe of an air conditioner in a building.
[0017]
In FIGS. 1 and 2, what is indicated by reference numeral 20 is a direct-acting drive valve. The drive valve 20 has a valve body 21 that forms a fluid flow path, and is vertically movable within the valve body 21. The valve shaft 22 includes a valve shaft 22 having an upper end protruding outside, a valve plug 23 attached to the inner end of the valve shaft 22 and controlling opening and closing of a flow path in the valve body 21. Are connected to an output shaft 26 of an actuator 25 via a crank mechanism 24. The opening degree of the drive valve 20 is a full closing angle of −80 °, a full opening angle of 80 °, and a full operating angle of 160 °, and the adjustable angle range of the full closing angle and the full opening angle by the actuator 25 is ± 5 ° and 1 °. It is adjusted by one. The crank mechanism 24 includes first and second links 24A and 24B. The crank mechanism 24 converts the rotation of the output shaft 26 into a linear motion and transmits it to the valve shaft 22.
[0018]
In this case, the present embodiment shows an example in which the valve shaft 22 is applied to the direct drive valve 20 in which the valve shaft 22 linearly reciprocates as a drive valve that is controlled to be opened and closed by the actuator 25. In the drive valve 20, the fully closed and fully opened states cannot be displayed directly by angles. However, the lift amount of the valve shaft 22 depends on the rotation angle θ of the output shaft 26 (first link 24A) and the rotation fulcrum P of the first link 24A. ₁ , P ₂ Distance R and the pivot point P of the second link 24B ₂ , P ₃ Since the distance L is determined by the distance L (see FIGS. 12 and 13), the operation angle of the output shaft 26 will be described here as the fully closed angle and the fully opened angle of the drive valve 20. When the present invention is applied to a rotary drive valve such as a ball valve or a butterfly valve, the crankshaft 24 is not required, and the valve shaft 22 and the output shaft 26 may be directly connected by coupling.
[0019]
The actuator 25 includes a housing 28 installed on a frame 27 provided above the drive valve 20, a cover (not shown) covering an opening of the housing 28, and the actuator 25 is provided in the housing 28. A drive motor 29, the output shaft 26 rotated forward and reverse by the drive motor 29, an operation range setting mechanism 30 for variably setting an operation range of the output shaft 26 within a range of ± 5 °, and a terminal block 31. , A circuit board and the like not shown. One end 26A of the output shaft 26 projects outside the housing 28, and the first link 24A is fixed. The other end 26B of the output shaft 26 has an oblong (oval) cross-sectional shape by forming flat surfaces facing each other on the peripheral surface, and the operating range setting mechanism is attached to the other end 26B. A part of a plurality of parts constituting the part 30 is attached.
[0020]
The operation range setting mechanism 30 includes a cam holder 36 fitted to the other end 26B of the output shaft 26 and fixed by a set screw 33, a cam 37 and a scale plate 38 detachably attached to the cam holder 36. , And two limit switches (fully closed switch, fully open switch) 40 and 41 fixed to the mounting plate 39 via the cam 37.
[0021]
2 to 7, the cam holder 36 has a cylindrical main body 36A (36A) integrally formed by injection molding of a synthetic resin. _-1 , 36A _-2 ) And a disk-shaped flange 36B integrally protruding from the outer peripheral surface of the longitudinally intermediate portion of the main body 36A. The main body 36A has a base end portion 36A fitted to the other end portion 26B of the output shaft 26. _-1 Are circular in cross section, and a tip portion 36A is larger than a portion to which the cam 37 is attached. _-2 Are formed in an oval cross section (oval shape). For this reason, the tip portion 36A _-2 Have flat surfaces 42 facing each other in parallel. On the other hand, the base end 36A _-1 , A pair of parallel anti-rotation walls 44 (FIG. 6) protruding from the flat surface 43 provided on the other end portion 26B of the output shaft 26 and facing each other in parallel.
[0022]
A pair of elastic engaging pieces 45 are integrally provided on the surface of the flange 36B. These engaging pieces 45 are provided at the distal end portions 36A of the cam holder 36. _-2 The protruding member is provided so as to be shifted 180 ° in the circumferential direction so as to face back to back via a vial, and a claw 45a having a triangular side cross-sectional shape is integrally protruded from the tip.
[0023]
In addition, since the cam holder 36 in the present embodiment is used as a common component for an operation range setting mechanism having a 90-degree full operation angle, which will be described later, a pair of cam holders 36 are similarly provided on the lower surface side of the flange 36B. Are vertically provided integrally. These engagement pieces 47 are provided at the base end 36A of the cam holder 36. _-1 The hook 47a is integrally and downwardly provided downward so as to face back to back with a claw 47a having a triangular side cross-sectional shape integrally formed at the lower end thereof. The engagement pieces 45 on the front side and the engagement pieces 47 on the back side are alternately provided by being shifted by 90 ° in the circumferential direction of the cam holder 36.
[0024]
Further, ridges 54 and 55 are formed on the outer peripheral edges of the front and back surfaces of the flange 36B, respectively. These ridges 54 and 55 constitute a tilt mechanism of a cam attached to the front and back surfaces of the flange 36B, respectively, and are arranged radially over the entire circumference of the flange 36B, in other words, at regular intervals in the circumferential direction. And a plurality of ridges having a triangular cross section formed so as to extend in the radial direction. For this reason, the ridges 54 and 55 are formed such that the width of the outer end is maximum and gradually narrows toward the center of the flange 36B. Such ridges 54 and 55 can be formed simultaneously with molding of the cam holder 36 or by knurling or the like. The pitch of the outer peripheral end is, for example, 0.241 mm, the height is about 0.2 mm, and 360 ridges are formed. This allows one ridge to adjust the angle of 1 °.
[0025]
2 and 8 to 11, the cam 37 is formed in a disk shape by a molded product of a synthetic resin, and the base 37 of the cam holder 36 is provided at the center. _-1 Has a circular center hole 60 that fits into the front end portion. The cam 37 has two engaging holes 61 into which two engaging pieces 45 protruding from the front side of the flange portion 36B are engaged, and a projecting portion 62 forming a large-diameter cam portion. ing. The engagement holes 61 are formed so as to be shifted by 180 ° so as to face each other with the center hole 60 interposed therebetween. The engaging hole 61 is formed as a long hole in the shape of an arc that is long in the circumferential direction of the cam 37, and the cam 37 is connected to the cam holder 36 with the engaging hole 61 and the engaging piece 45 of the cam holder 36. The snap-fit mechanism 46 which is detachably connected to be rotatable at a certain angle is constituted. The rotatable angle of the cam 37 by the engagement hole 61 is 10 ° at the maximum, and thereby the variable range of the fully closed angle and the fully open angle of the drive valve 20 by the operation range setting mechanism 30 is ± 5 °. Accordingly, the fully closed angle is variably set in the range of -85 ° to -75 °, and the fully open angle is variably set in the range of 75 ° to 85 °.
[0026]
The protruding portion 62 is composed of a substantially trapezoidal projection in a plan view, which is integrally provided on a part of the outer peripheral surface of the cam 37 toward the radial direction and the rear surface side. 62b, and an arc-shaped cam surface 62c connecting the both side surfaces 62a and 62b. Further, a plurality of ridges 64 are radially formed on the outer peripheral edge of the rear surface of the cam 37 corresponding to the ridges 54 provided on the front side of the flange 36B of the cam holder 36 over the entire circumference. The ridges 64 have the same shape, size, pitch and number as the ridges 54, and constitute a tilt mechanism 66 that meshes with each other to enable the angle adjustment of the cam 37 with respect to the cam holder 36. . The meshing state of the ridges 54 and 64 is maintained by the coupling force between the cam holder 36 and the cam 37 by the snap-fit mechanism 46, and the cam 37 is manually turned to mesh the ridges 54 and 64. Is changed, the tilt angle of the cam 37 with respect to the cam holder 36 is adjusted by 1 ° each time the engagement between the ridges 54 and 64 is shifted by one. At the center of the surface of the protrusion 62, a pointer 67 for indicating the operation angle of the output shaft 26 is provided.
[0027]
In FIG. 2, the scale plate 38 is formed in a disk shape and has a front end portion 36 </ b> A of the cam holder 36 in the center. _-2 There is a total of four tongue-shaped locking pieces 71 at the edge of the hole, which bite into the flat surface 42 to prevent the scale plate 38 from coming off. It protrudes toward the center so as to face each other. Also, on the surface of the scale plate 38, scale lines 72a and 72b indicating the fully closed angle and the fully opened angle of the drive valve 20, and a reference line 72c are displayed.
[0028]
The close-side switch 40 and the open-side switch 41 are three-terminal limit switches with rollers, and are fixed to the mounting plate 39 so as to face each other via the cam 37.
[0029]
To assemble the operation range setting mechanism 30 having such a structure, first, the clutch is disengaged and the output shaft 26 is made rotatable with respect to the drive motor 29. Next, the base end portion 36A of the cam holder 36 _-1 Is fitted to the other end 26 </ b> B of the output shaft 26 and is fixed by a set screw 33. Next, the cam holder 36 and the cam 37 are connected by a snap-fit mechanism 46 and a tilt mechanism 66 so as to be detachable and angle-adjustable. That is, the cam 37 is connected to the distal end portion 36A of the cam holder 36. _-2 36A from the side _-1 And a pair of engaging pieces 45 are engaged with the engaging holes 61. Then, when the cam 37 is pressed against the surface of the flange portion 36B to engage the ridges 54 and 64 with each other, the engaging piece 45 protrudes from the engaging hole 61 and the claw 45a engages with the surface of the cam 37, and the cam holder The cam 36 and the cam 36 are detachably connected and can be adjusted in angle.
[0030]
Next, the scale plate 38 is connected to the tip 36A of the cam holder 36. _-2 And the cam 37 is rotated such that the reference line 72c and the pointer 67 of the cam 37 coincide with each other. When the pointer 67 and the reference line 72c coincide with each other, it means that the opening degree of the drive valve 20 is set to the full closing angle −80 ° and the full opening angle 80 °. When changing the fully open angle, for example, when setting the fully closed angle to -85 ° and the fully open angle to 75 °, the cam 37 is rotated by 5 ° in the opening direction from the state where the hands 67 and the reference line 72c coincide. The angle change at this time can be adjusted by 1 ° by shifting the meshing state of the ridges 54, 64 by one, so that the cam 37 is rotated to shift the meshing state of the ridges 54, 64. It is possible to accurately know the adjustment angle by counting the click feeling felt by the fingertip when touching.
[0031]
Next, the close-side switch 40 and the open-side switch 41 are respectively fixed to predetermined positions so as to face the mounting plate 39 via the cam 37, and these switches 40 and 41 are turned on by the cam 37 when fully closed and fully open. , Confirm whether to turn off. In this checking operation, first, the output shaft 26 is manually rotated to position the protrusion 62 of the cam 37 between the close switch 40 and the open switch 41. FIG. 14A shows this state. In this state, the lift amount of the valve shaft 22 is half and the valve opening is 50% (the rotation angle of the output shaft 26 is 0 °). At this time, the closing switch 40 and the opening switch 41 are not in contact with the cam 37, and both are kept off.
[0032]
Next, the output shaft 26 is rotated in the closing direction from the state where the valve opening is 50%. For example, when the output shaft 26 rotates 75.02 ° in the closing direction, the left side surface 62a of the protrusion 62 comes into contact with the roller 80 of the closing switch 40 and starts pressing (FIGS. 14B and 14C). When the output shaft 26 rotates by 80 °, the closing switch 40 is turned on immediately before the roller 80 rides on the cam surface 62c of the projection 62 as shown in FIG. Therefore, it can be confirmed that the drive valve 20 is in the fully closed state (valve opening degree 0%). Conversely, when the output shaft 26 is rotated counterclockwise by 80 ° from the state in which the valve opening is 50%, the roller 81 of the open switch 41 immediately before riding on the cam surface 62c from the right side surface 62b of the projection 62. The opening switch 41 is turned ON. Accordingly, it is possible to confirm that the drive valve 20 is fully opened (the valve opening degree is 100%). If the timing at which the close switch 40 and the open switch 41 are turned on is off, the rotation fulcrum P ₁ , P ₂ Between the distance R and the pivot point P of the second link 24B ₂ , P ₃ Adjust the distance L between them.
[0033]
As described above, in the operation range setting mechanism 30 according to the present invention, when the cam 37 is fitted into the cam holder 36 and pressed against the flange 36B, the cam holder 36 and the cam 37 are snap-fitted with the engagement piece 45 and the engagement hole 61. Since the coupling is separable by the mechanism 46, the work of attaching the cam 37 to the cam holder 36 can be performed easily and in a short time without the need for a set screw, a driver, and the like. Also, when removing, when the engagement with the cam 37 is released by pressing the claw 45a of the engagement portion 45 with a fingertip, the engagement with the cam 37 is released from the coupling state by the snap-fit mechanism 46. The cam 37 can be easily removed from the cam holder 36 without using it.
[0034]
In addition, since the cam 37 is connected to the cam holder 36 so that the angle can be adjusted by the tilt mechanism 66 formed by the engagement between the ridges 54 and 64, the cam 37 is turned with a fingertip to engage the ridges 54 and 64 with each other. If the position is shifted, the mounting angle of the cam 37 changes, and the operating range of the output shaft 26 can be easily changed. In addition, since the meshing state between the ridges 54 and 64 can be adjusted by 1 ° by shifting the mesh by one, the number of click sensations transmitted to the fingertip when the ridges 54 and 64 are shifted can be counted to know exactly how many changes have been made. be able to.
[0035]
FIG. 15 is an exploded perspective view showing another embodiment of the present invention, and FIGS. 16 (a), (b) and (c) are a plan view, a front view, a bottom view and an enlarged view of arrow B of the cam. FIG. 17 is a diagram showing the positional relationship between the cam and the switch when the valve opening is 50%. The same or similar members as those of the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.
This embodiment shows an example of an operation range setting mechanism applied to a rotary drive valve (for example, a ball valve or a butterfly valve) of a fully-closed, fully-opened, or fully-operated variable angle type. Has first and second cams 90 and 91, these cams 90 and 91 are respectively attached to the front side and the back side of the flange 36B of the cam holder 36, and the fully closed angle is -45 ° and the fully opened state. The other structures are the same except that the angle is 45 °, the total operating angle (variable) is 90 °, and the variable range is ± 30 °.
[0036]
The first and second cams 90 and 91 have exactly the same shape, and the first cam 90 is detachably attached to the upper surface of the flange portion 36B with the lower surface side down by the snap-fit mechanism 46. The cam 91 is turned upside down and detachably attached to the lower surface of the flange 36B by the snap fit mechanism 46. The first and second cams 90 and 91 are connected to the flange 36B by tilt mechanisms 46 and 48 formed by engagement of the ridges 54 and 64 and 55 and 64 so as to be adjustable in angle. .
[0037]
The first cam 90 is formed in a disc shape. The cam 90 has a center hole 60, a pair of engagement holes (elongated holes) 61, a projection 93 constituting a large diameter portion, and a pointer 67. have. The projecting portion 93 is formed in a substantially parallelogram shape having a left-right asymmetric shape in a plan view, so that two side surfaces 94 a and 94 b inclined substantially in parallel and an arc-shaped cam surface connecting the two side surfaces 94 a and 94 b are formed. 94c. The two side surfaces 94a and 94b are inclined in the closing direction when the first cam 90 is installed on the flange portion 36B with the front side facing up, and the right side surface 94b is turned by the turning in the opening direction. When the roller 81 contacts and presses the roller 81, the roller 81 rides on the cam surface 94c to turn on the open switch 41.
[0038]
On the other hand, the second cam 91 has the same shape as the first cam 90 but is turned upside down and attached to the lower surface side of the flange 36B, so that the right side surface 94b of the projection 93 is on the left side as shown in FIG. When the output shaft rotates in the closing direction, the output shaft contacts and presses the roller 80 of the closing switch 40. For this reason, the roller 80 rides on the cam surface 94c to turn on the close-side switch 40.
[0039]
When changing the fully closed angle and the fully opened angle of the drive valve, the first and second cams 90 and 91 may be adjusted by turning the cams 90 and 91 by a required angle in the closing direction or the opening direction, respectively. When only the first cam 90 is rotated, only the full closing angle can be variably set in the range of −75 ° to −15 °, and when only the second cam 91 is rotated, Only the fully open angle can be variably set within the range of 15 ° to 75 °, and when the first and second cams 90 and 91 are rotated, the fully closed angle is −75 ° to −15 °, The angle can be variably set within a range of 15 ° to 75 °. That is, since the first and second cams 90 and 91, each of which can independently adjust the angle, are provided, it is possible to provide an operation range setting mechanism of a fully-closed, fully-opened, and all-operable-angle variable type.
[0040]
In the above-described embodiment, an example is shown in which the engagement pieces 45 and 47 are protruded from the cam holder 36 and the elongated holes 61 are formed in the cam 37. However, the present invention is not limited to this. And vice versa.
In the above-described embodiment, the present invention is applied to an electric drive valve of an air conditioner. However, the present invention is not limited to this. For example, the present invention can be applied to a combustion device or a damper that opens and closes an exhaust port of a duct.
[0041]
【The invention's effect】
As described above, the operating range setting mechanism of the actuator according to the present invention is configured such that the cam holder and the cam are detachably connected by the snap-fit mechanism, and the cam is connected to the cam holder by the tilt mechanism so as to be adjustable in angle. It is not necessary to use screws, etc., and the assembling, removing, and changing of the operation range of the cam with respect to the cam holder can be easily and quickly performed.
Also, since the snap-fit mechanism is constituted by an engagement piece having a claw and a long hole, and the tilt mechanism is constituted by a ridge provided on the cam holder and the cam and meshing with each other, the structure of both these mechanisms is extremely simple, The number of parts can be reduced.
[Brief description of the drawings]
FIG. 1 is a front view of a valve provided with an actuator according to the present invention.
FIG. 2 is an exploded perspective view showing an embodiment of an operation range setting mechanism of the actuator.
FIG. 3 is a front view of a cam holder.
FIG. 4 is a plan view of the cam holder.
FIG. 5 is a bottom view of the cam holder.
FIG. 6 is a sectional view taken along line VI-VI of FIG. 4;
FIG. 7 is an enlarged view as viewed in the direction of arrow A in FIG. 5;
FIG. 8 is a plan view of a cam.
FIG. 9 is a side view of the cam.
FIG. 10 is a bottom view of the cam.
FIG. 11 is an enlarged view as viewed in the direction of arrow B in FIG. 8;
FIG. 12 is a diagram showing a relationship among a rotation angle of a link, an operation angle of an output shaft, and a lift of a valve shaft.
FIG. 13 is a graph showing a relationship between an operation angle of an output shaft and a lift amount of a valve shaft.
FIGS. 14A to 14D are diagrams for explaining the operation of the closing switch.
FIG. 15 is an exploded perspective view showing another embodiment of the present invention.
FIGS. 16 (a), (b), (c) and (d) are a plan view, a front view, a bottom view and an enlarged view of arrow B of the cam.
FIG. 17 is a diagram showing a positional relationship between a cam and a switch when the valve opening is 50%.
FIGS. 18 (a) and (b) are plan views showing a conventional example of an operation range setting mechanism for adjusting a mounting angle of a cam.
[Explanation of symbols]
Reference numeral 20: drive valve, 22: valve shaft, 25: actuator, 26: output shaft, 30: operation range setting mechanism, 36: cam holder, 36A: main body, 36B: flange, 37: cam, 38: scale plate, 45: Engaging piece, 46: snap-fit mechanism, 47: engaging piece, 48: snap-fit mechanism, 54, 55, 61: engaging hole (long hole), 62: protruding part, 64: protruding body, 66: tilt Mechanism, 67 ... pointer.

Claims (3)

In the operation range setting mechanism that sets the operation range of the output shaft of the actuator,
A cam holder attached to the output shaft, a cam attached to the cam holder, a pair of switches fixedly arranged to face each other via the cam and turned on and off by the cam, respectively; and the output shaft attached to the cam holder. And a scale plate on which an opening scale corresponding to the operation angle of is displayed.
An operation range setting mechanism for an actuator, wherein the cam holder and the cam are connected by a snap-fit mechanism and a tilt mechanism so that the angle of the cam can be changed by a predetermined angle with respect to the cam holder. In the operation range setting mechanism that sets the operation range of the output shaft of the actuator,
A cam holder attached to the output shaft, a cam attached to the cam holder, a pair of switches fixedly arranged to face each other via the cam and turned on and off by the cam, respectively; and the output shaft attached to the cam holder. And a scale plate on which an opening scale corresponding to the operation angle of is displayed.
The cam holder comprises a tubular portion fitted to the output shaft, and a flange integrally provided on the outer periphery of the tubular portion,
The cam is formed in a ring shape that fits on the outer periphery of the cylindrical portion of the cam holder, and a part that turns on and off the respective switches on a part of the outer peripheral surface is integrally provided, and a projection is provided.
The flange and the cam of the cam holder are detachably and rotatably coupled to each other by a snap-fit mechanism including an engagement piece and an elongated hole into which the engagement piece is engaged. The cam is connected to the cam holder by a tilt mechanism constituted by a plurality of ridges formed radially on the surfaces in contact with each other and meshing with each other so as to be able to change the angle by a predetermined angle. Operating range setting mechanism. In the operation range setting mechanism that sets the operation range of the output shaft of the actuator,
A cam holder attached to the output shaft, first and second cams attached to the cam holder, and first and second cams fixedly arranged to face each other via these cams and turned on and off by corresponding cams, respectively. Switch, and a scale plate attached to the cam holder and displaying an opening scale corresponding to the operating angle of the output shaft,
The cam holder comprises a tubular portion fitted to the output shaft, and a flange integrally provided on the outer periphery of the tubular portion,
The first and second cams are formed in a ring shape that fits around the outer periphery of the cylindrical portion of the cam holder, and a projection that turns on and off the first and second switches respectively is integrated with a part of the outer peripheral surface. Protruding into
The first and second cams are detachably and rotatably coupled to the front and back surfaces of the flange portion of the cam holder by a snap fit mechanism including an engagement piece and an elongated hole into which the engagement piece is engaged. In addition, the first and second cams are tilted by a tilt mechanism formed by a plurality of ridges formed radially on the surfaces of the flange portion and the first and second cams that are in close contact with each other and meshing with each other. An operation range setting mechanism for an actuator, wherein the mechanism is connected to the cam holder so that the angle can be changed by a predetermined angle.

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