JP2560057Y2 - Electric diaphragm device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorized aperture device mounted on a photographing device such as a video camera.

[0002]

2. Description of the Related Art FIG. 2 is an exploded perspective view showing an example of a conventional electric diaphragm device. In the figure, 10 is the ground plane, 2
Reference numeral 0 denotes a motor for driving the diaphragm blades attached to one surface (upper surface in FIG. 2) of the main plate 10, and 30 denotes a motor arranged on the other surface (lower surface in FIG. 2) of the main plate 10. The aperture blade drive levers 40 and 50 which are connected to the rotor shaft 23 and are rotated in the direction of arrow (a) or (b) are locked at both ends of the aperture blade drive lever 30 and rotate the lever 30. The diaphragm blade 60, which moves in the directions of the arrows f1 and f2 according to the movement, is screwed to the other surface of the base plate 10 (that is, the lower surface in FIG. 2) to cover the diaphragm blades 40 and 50. Cover, 70 is aperture blade 4
An ND filter adhered to one end of the opening of No. 0.

The base plate 10 is integrally formed by injection molding of plastic and has an opening 11 through which photographing light passes.
, A yoke support seat 12, and two bearing mounting columns 13, 14.
Is provided. Here, the yoke support seat 12 is
The yoke 21 is for supporting a cylindrical yoke 21 for mounting the motor, and is provided in a cylindrical shape at a position slightly away from the opening 11. A shaft hole 15 through which the rotor shaft 23 of the motor 20 is inserted is provided at a position on the ground plane inside the yoke support seat 12 which is the center of the yoke support seat 12. The rotor shaft 23
Is projected downward from the base plate 10 through the shaft hole 15.

In addition, the two bearing mounting columns 13, 14
Are for fixing the bearing plate 22 of the motor 20, project from the inside of the yoke support seat 12, and have screw holes 13 a, for screw B 1 for fixing the bearing plate 22, at the respective end surfaces. 14a are formed.

A boss 1 is provided on both sides of the main plate 10.
Screw holes 16 a, 17 penetrating in the thickness direction of the base plate 10 are provided in the respective boss portions 16, 17.
a is provided. These screw holes 16a, 17a are for screwing the cover 60 to the base plate 10, and the cover 60 is provided with ear pieces 61, 62 to be brought into contact with the bosses 16, 17, and these ears are provided. Pieces 61, 62
Are provided with holes 61a and 62a through which screws B2 screwed into the screw holes 16a and 17a are inserted.

Further, a hole 63 is provided at one end (right end in FIG. 2) of the cover 60. This hole 63
Corresponds to a screw hole (not shown) provided on the lower surface of the base plate 10, and one end of the cover 60 is fixed to the base plate 1 with a screw B 3.
It is for screwing to zero.

The aperture blade driving lever 30 has a boss 31 with a hole at the center thereof, and pins 32 and 33 for engaging with the above-mentioned aperture blades 40 and 50 project from both ends. I have. The hole 34 of the holed boss 31
, The rotor shaft 23 of the motor 20 is fitted, the pin 32 is slidably inserted into the lateral groove 51 of the diaphragm blade 50, and the pin 33 is slidable in the lateral groove 41 of the diaphragm blade 40. Through. The aperture boss 31 is always provided with the aperture blade drive lever 30 on one side (in the aperture closing direction).
A torsion spring 35 for urging the diaphragm blades 40 and 50 in the initial position direction is mounted.

The aperture blades 40 and 50 have long grooves 42, 43, 44, 52, 53 and 5 in parallel with their side edges.
A guide pin (not shown) projecting from the lower surface of the main plate 10 is inserted into each of these long grooves.

The motor 20 includes a rotor 24 made of a permanent magnet having rotor shafts 23 and 29, a pair of coil bobbins 25 and 26 opposed to each other with the rotor 24 interposed therebetween so as to surround the rotor 24. Each coil bobbin 2
Coils 27 and 28 wound around the coil bobbins 25 and 26, a cylindrical yoke 21 set on the yoke support seat 12 of the base plate 10 so as to surround the coil bobbins 25 and 26, 14 and a bearing plate 22 which is screwed to the distal end.

In the rotor 24, the rotor shaft 23 and the rotor shaft 29 are on the same axis, and the rotor shaft 23 is inserted through the shaft hole 15 of the
By being tightly fitted in the hole 34 of the boss 31 having the zero hole, the boss 31 is connected to the aperture blade drive lever 30. The rotor shaft 29 is provided with a bearing hole 22a of the bearing plate 22.
It is rotatably supported by.

The bearing plate 22 is electrically connected to both ends of the coil 27 and protrudes upward from the upper surface of the coil bobbin 25, in addition to the bearing hole 22a for rotatably supporting the rotor shaft 29. Notch portion 22f through which terminals 27a and 27b are inserted, and hole 22 through which terminals 28a and 28b electrically connected to both ends of coil 28 and projecting upward from the upper surface of coil bobbin 26 are inserted.
d and 22e, and holes 22b through which screws B1 screwed into screw holes 13a and 14a at the tips of the bearing mounting columns 13 and 14 are passed.
22c, and is fixed to the distal ends of the bearing mounting columns 13, 14 by two screws B1.

[0012]

The conventional electric throttle device described above has the following problems (1) and (2).

(1) When assembling the motor 20 to the main plate 10, first, the coil bobbin 2
5 and the coil bobbins 26, and a temporary fixing tape T is wound around the outer periphery of these coil bobbins 25 and 26 to make the rotor
A stator unit is manufactured, and the rotor / stator unit is inserted between the two bearing mounting columns 13 and 14 of the main plate 10. At this time, the rotor shaft 23 is inserted through the shaft hole 15. Then, the yoke 21 and the bearing plate 22 are sequentially fitted to the rotor / stator unit, and
Then, the bearing plate 22 is fixed to the bearing mounting columns 13 and 14 to complete the process.

However, in order to increase the driving force of the motor 20, the coils 2 in the coil bobbins 25 and 26 are required.
It is necessary to increase the number of windings of the coils 7 and 28 so as to approach the rotation center of the rotor 24. In order to secure a space exclusive for the coils 27 and 28, the outer diameters of the bearing mounting columns 13 and 14 are usually used. I have to make it thin. Then, screw holes 13a, 1 are formed in the distal end portions of the small-diameter bearing mounting columns 13, 14.
In the conventional structure equipped with 4a, the thickness of the bearing mounting columns 13, 14 around the screw holes 13a, 14a becomes extremely thin. As a result, when the base plate 10 is integrally molded by plastic injection molding, the flow of the plastic material is increased. May be hindered by the thin portions around the screw holes 13a, 14a, or may be difficult to separate from the mold, or the screw B1 may be tightened when the bearing plate 22 is fixed to the bearing mounting columns 13, 14. As a result, a crack may occur in the thin portion, and the product yield may be reduced. In addition, the screwing of the bearing plate 22 increases the number of parts to be managed and the number of steps in assembling, thus preventing a reduction in production cost of the electric drawing device.

(2) The conventional electric diaphragm device shown in FIG. 2 has a structure in which the cover 60 is screwed to the main plate 10 with three screws (two screws B2 and one screw B3). ,
Since the cover 60 is a thin plate, bending and torsion are likely to occur due to the difference in the tightening force of the three screws for fixing to the base plate 10, and the movement of the diaphragm blades 40 and 50 due to the bending and torsion generated in the cover 60. , There is a risk that the product yield will decrease. Also, the cover 60
However, the number of parts to be managed and the number of steps for assembling are increased due to the screwing, so that the production cost of the electric drawing device is prevented from being reduced.

The present invention has been made in view of the above circumstances, and it is possible to improve the product yield by preventing damage to parts at the time of molding and assembling. It is an object of the present invention to provide an electric throttle device capable of promoting reduction in production cost by reducing the number of processes.

[0017]

According to a first aspect of the present invention, there is provided an electric diaphragm apparatus, comprising: a base plate having an opening for photographing light; and a base plate provided on one surface of the base plate and moved on the base plate. An aperture blade for changing the opening diameter of the opening, and a motor attached to the ground plate as a drive source for moving the aperture blade are provided, and the ground plate rotatably supports a rotor shaft of the motor. The bearing mounting column for fixing the bearing plate is configured to be protruded by integral molding.

A locking projection is provided on one of the bearing plate and the bearing mounting column, and a concave portion for engaging with the locking projection is provided on the other, and the engagement between the locking projection and the concave portion is provided. In some cases, the bearing plate is fixed to a bearing mounting column.

According to a second aspect of the present invention, there is provided an electric diaphragm apparatus, comprising: a base plate having an opening for photographing light; and an opening diameter of the opening provided on one surface of the base plate and moved on the base plate. A diaphragm blade to be changed is provided, and a thin plate-shaped cover attached to the main plate so as to cover the diaphragm blade.

The bottom plate has two ends in the width direction perpendicular to the direction in which the diaphragm blades move, the two ends of the base plate being located at both ends in the width direction perpendicular to the direction in which the diaphragm blades move. A plurality of engaging flanges that engage the ends of the cover on the side of the cover to restrain the cover from moving in the thickness direction, and engage the holes provided in the cover to cover the surface of the cover. And an engaging pin for restraining the movement of the diaphragm is integrally formed, and an engaging flange of the main plate is provided at both ends of the cover in a width direction orthogonal to a moving direction of the diaphragm blade in a thickness direction thereof. A notch portion through which the cover, the flange of the main plate, the engaging pin and the hole of the cover are moved when the cover is moved in the surface direction after being brought close to the main plate so as to pass through the cut portion. The end of the bar is engaged with the flange, and at the same time, the engagement pin is engaged with the hole of the cover, so that the cover is fixed to the main plate. .

[0021]

In the electric throttle device according to the first aspect, it is not necessary to provide a screw hole for fixing the bearing plate of the motor to the bearing mounting column of the base plate, and the thickness of the bearing mounting column can be reduced by providing the screw hole. Can be avoided. Therefore, when the base plate is produced by injection molding of a plastic material, the inconvenience of obstruction of the flow of the plastic material or poor separation from the mold is eliminated, and it is possible to reduce product defects in molding. At the same time, it is possible to avoid the damage of the bearing mounting column caused by the tightening of the screw at the time of assembly, and it is possible to improve the product yield. Further, by eliminating the use of screws as a means for fixing the bearing plate, it is possible to reduce the number of components to be managed and the number of steps in assembling, thereby promoting a reduction in production cost.

In the electric diaphragm device according to the second aspect, the screw is not used as a means for fixing the thin plate-shaped cover to the base plate, and the cover is deformed due to a variation in the tightening force of the screw, and the diaphragm blade is deformed. Can be avoided, and the product yield can be improved.

Furthermore, the elimination of the use of screws as a means for fixing the cover makes it possible to reduce the number of components to be managed and the number of steps in assembling, thereby promoting a reduction in production costs. Can also.

[0024]

FIG. 1 is an exploded perspective view showing the structure of an embodiment of an electric throttle device according to the present invention. In addition, in one embodiment of the present invention, the same components as those of the conventional electric throttle device shown in FIG.

An electric diaphragm device according to one embodiment of the present invention includes a main plate 80, a motor 100 for driving diaphragm blades mounted on the upper surface side of the main plate 80, and a motor disposed on the lower surface side of the main plate 80 and the motor. An aperture blade drive lever 30 connected to the rotor shaft 23 of the aperture 100 and rotated in the arrow (a) or (b) direction, and locked at both ends of the aperture blade drive lever 30 to rotate the lever 30 According to the arrow f1
Diaphragm blades 40, 50 moving in the direction of arrow f2
A cover 90 attached to the lower surface side of the base plate 80 to cover the diaphragm blades 40 and 50; and an ND filter 70 bonded to one end of an opening of the diaphragm blade 40.

The base plate 80 is formed integrally by injection molding of plastic and has an opening 81 through which photographing light passes.
, A yoke support seat 82, and two bearing mounting columns 83, 84.
Is provided. Here, the yoke support seat 82 is
The yoke 21 is for supporting a cylindrical yoke 21 for mounting a motor, and is protruded cylindrically at a position slightly away from the opening 81. A shaft hole 85 through which the rotor shaft 23 of the motor 100 is inserted is provided at a position at the center of the yoke support seat 82 on the ground plane inside the yoke support seat 82, The rotor shaft 2
3 protrudes below the main plate 80 through the shaft hole 85.

The two bearing mounting columns 83, 84
Is for fixing the bearing plate 102 of the motor 100, and protrudes from the inside of the yoke support seat 82, and the locking projections 830, 840 are provided at the respective ends. These locking projections 830 and 840 are for fixing the bearing plate 102 of the motor 100, and are shown in FIG.
As shown in FIG. 4, the fitting shaft portions 83 a and 84 a projecting in the axial direction of the pillars with the diameter slightly smaller than the base ends of the bearing mounting columns 83 and 84, and the respective fitting shaft portions 83.
a, 84a, and locking pieces 83b, 84b projecting from the lower side of the bearing plate 102 in the radial direction. As shown in FIG. 4, each of the locking pieces 83b and 84b has a shape having a slope S on the upper surface side.

The base plate 80 has the cover 90
An engagement flange 86 which contacts an outer surface (a lower surface in FIG. 4) of the cover 90 to restrict the movement of the cover 90 in the plate thickness direction, and an engagement hole provided in the cover 90 (in this embodiment, (Notched) 92 to engage the cover 9
An engagement pin 87 for restraining movement in the plane direction of 0 is protruded by integral molding. As shown in FIGS. 6 and 7, the engagement flange 86 separates the cover 90 from the base plate 80.
And a plate-like flange portion 8 protruding along the surface of the cover 90 from the tip of the post portion 86a.
6b, two on each side of the base plate 80, and one on the one end side of the base plate 80 on which the aperture blade drive lever 30 is provided, for a total of five. The engaging pins 87 are provided one by one on both side edges on one end side of the base plate 80.
The projection length is set to be small (about half the thickness of the cover 90 in the illustrated example) so that the cover 90 is not subjected to excessive deformation exceeding elastic deformation when engaging with the cover 2.

The cover 90 is formed by forming a predetermined hole in a flat metal plate by press working or the like. Except for the structure for fixing to the base plate 80,
It has the same configuration as the conventional cover 60 shown in FIG. In the cover 90 of the embodiment, the structure for fixing the cover 90 to the base plate 80 includes a notch 91 for supporting the cover 90 by the engaging flange 86 and an engaging hole for engaging the engaging pin 87. 92.

To fix the cover 90 to the base plate 80, the cover 90 and the base plate 80 are butted against each other with a slight shift in the longitudinal direction. It is designed so that it can be achieved by a simple operation of sliding with respect to 80. Specifically, the notch 91 is provided with a notch 9 for abutment.
1a and the alignment notch 91b have a stepped shape. Here, the notch 91a for butting is for inserting the flange portion 86b when the cover 90 and the base plate 80 are butted slightly apart from each other in the longitudinal direction. The alignment notch 91b
Is a state in which the cover 90 and the main plate 80 are slightly shifted from each other in the longitudinal direction and butted against each other.
When the cover 90 and the main plate 80 are slid with respect to each other by a certain amount, only the insertion of the support portion 86a is allowed, and the flange portion 86b presses the outer surface of the cover 90. Notch for butt 91
The notch width is set smaller than a. The engaging hole 92 is formed when the cover 90 and the base plate 80 are butted against each other with a slight displacement in the longitudinal direction.
7, the cover 90 and the main plate 80 are slid with respect to the main plate 80 by a predetermined amount from a state where the cover 90 and the main plate 80 are slightly shifted from each other in the longitudinal direction, and are aligned with each other. The position is set so that the engagement pin 87 is engaged just when the operation is performed.

The motor 100 has rotor shafts 23 and 29
, A pair of coil bobbins 25 and 26 opposed to each other across the rotor 24 so as to surround the rotor 24, and each of the coil bobbins 2.
Coils 27 and 28 wound around the coil bobbins 25 and 26, a cylindrical yoke 21 set on a yoke support seat 82 of the base plate 80 surrounding the coil bobbins 25 and 26, and the bearing mounting columns 83 and Bearing plate 1 fixed to the tip of
02, and the constituent members other than the bearing plate 102 are the same as those of the related art, and thus detailed description is omitted.

As shown in FIG. 3, the bearing plate 102 has a bearing hole 102a for rotatably supporting the rotor shaft 29.
In addition, a cut-out portion 102f electrically connected to both ends of the coil 27 and through which terminals 27a and 27b protruding upward from the upper surface of the coil bobbin 25 are inserted, and electrically connected to both ends of the coil 28. And terminals 28a, 28b projecting upward from the upper surface of the coil bobbin 26.
Are formed, and concave portions 102b and 102c that engage with the locking projections 830 and 840 at the tips of the bearing mounting columns 83 and 84 are formed.

Here, the concave portion 102b is
The movable piece 10 which provides a through hole 103 into which the fitting shaft portion 83a fits, and an engaging recess 104 into which the locking piece 83b fits.
And 5. Here, the movable piece 105 is the bearing plate 1
02, which is a part of the peripheral wall, is easily elastically deformed in the radial direction of the bearing plate 102 by slits 106 provided on both sides thereof.

The recess 102c has a through hole 107 into which the fitting shaft 84a of the bearing mounting column 84 fits, and the locking piece 8
Movable piece 109 that provides an engagement recess 108 into which 4b fits
It is composed of Here, the movable piece 109 is a part that forms a part of the peripheral wall of the bearing plate 102, as in the case of the above-described movable piece 105, and the diameter of the bearing plate 102 is determined by slits (not shown) provided on both sides thereof. It is easy to elastically deform in the direction.

Next, the operation of assembling the motor 100 to the main plate 80 will be described. First, a coil bobbin 25 and a coil bobbin 26 are abutted so as to surround the rotor 24, and a temporary fixing tape T is wound around the outer periphery of the coil bobbins 25, 26 to form a rotor-stator unit. It is inserted between the two bearing mounting columns 83 and 84. At this time, the rotor shaft 23
Is inserted through the shaft hole 85. Next, the yoke 21 and the bearing plate 102 are sequentially fitted to the rotor / stator unit.

The yoke 21 is placed on the yoke support seat 82. The bearing plate 102 has a bearing hole 102a in the rotor shaft 29 and a notch 102f in the terminals 27a and 27b.
When the holes 102d and 102e are pushed down to the terminals 28a and 28b, and the through holes 103 and 107 are pushed down to the fitting shafts 83a and 84a at the ends of the bearing mounting columns 83 and 84, respectively, the movable piece is pushed down. The lower ends of 105 and 109 correspond to the slopes S of the locking pieces 83b and 84b of the bearing mounting columns 83 and 84. When further depressed, the movable pieces 105 and 109 are elastically deformed outward, and the locking pieces 83b and 84b are brought into contact with the engagement recesses 1.
Go to 04,108 side.

When the engaging pieces 83b, 84b are fitted into the respective engaging recesses 104, 108, the movable pieces 105, 109
Of the bearing plate 102, the engagement between the recesses 102b, 102c of the bearing plate 102 and the locking projections 830, 840 of the bearing mounting columns 83, 84 is completed.
Are fixed to the bearing mounting columns 83, 84. Thus, the assembly of the motor 100 to the main plate 80 is completed.

After assembling the motor 100 to the main plate 80,
An aperture blade drive lever 30 is attached to the rotor shaft 23, and the aperture blade drive lever 30 is further attached to each aperture blade 40, 50.
Finally, the cover 90 is assembled to the main plate 80.

Next, an operation of assembling the cover 90 to the main plate 80 will be described.

First, as shown in FIG. 5 and FIG. 6, the cover 90 and the base plate 80 are butted to each other with a slight shift in the longitudinal direction.
1a, each flange portion 86b of the main plate 80 is inserted. In that case, as shown in FIG.
, A part of the cover 90 floats from the main plate 80. However, when the cover 90 is slid with respect to the main plate 80 by a predetermined amount while the cover 90 is lightly pressed against the main plate 80, and the cover 90 and the main plate 80 are aligned, as shown in FIGS. Each flange 8
6b presses the outer surface of the cover 90 and the engaging pin 8
7 fits into the engaging hole 92 of the cover 90 and the engaging flange 8
6 and the engagement pin 87 cooperate to cover the base plate 8.
The state is fixed to 0.

When the cover 90 is fixed to the main plate 80, the assembly of the electric diaphragm device of one embodiment is completed.

In the electric throttle device of the embodiment described above, it is not necessary to equip the bearing mounting columns 83 and 84 of the base plate 80 with screw holes for fixing the bearing plate 102 of the motor 100. The thickness of the bearing mounting columns 83 and 84 can be avoided. Therefore, when the base plate 80 is manufactured by injection molding of a plastic material, the inconvenience of obstructing the flow of the plastic material or deteriorating the separation from the mold is eliminated, and product defects in molding can be reduced. At the same time, it is possible to avoid damage to the bearing mounting columns 83 and 84 caused by fastening the screws at the time of assembly.

Also, in the above-described embodiment, even when the thin plate-shaped cover 90 is fixed to the base plate 80, no screws are used, and the cover 90 is deformed due to a variation in the tightening force of the screws. It is also possible to avoid the disadvantage that the operation of the aperture blades 40 and 50 is hindered.

As described above, the product yield can be greatly improved.

Furthermore, the elimination of the use of a screw as a means for fixing the bearing plate 102 and the cover 90 makes it possible to greatly reduce the number of parts to be managed and the number of steps in assembling, thereby reducing production costs. It can also promote cost reduction.

In the above-described embodiment, the bearing mounting column 8
As a fixing means between the bearing mounting plates 83 and 84, the bearing mounting columns 83 and 84 are provided with locking projections and the bearing plate 102 is provided with recesses. It is also conceivable that the bearing plate 102 is provided with a locking projection. Also, the bearing mounting columns 83, 8
The specific structures of the locking projections and the concave portions for fixing the bearing 4 and the bearing plate 102 are not limited to the embodiment, and various known locking mechanisms can be used.

[0047]

As is apparent from the above description, in the electric throttle device according to the first aspect, it is not necessary to provide a screw hole for fixing the bearing plate of the motor to the bearing mounting column of the main plate, and the screw is not required. The thinning of the bearing mounting column due to the provision of the hole can be avoided. Therefore, when the base plate is produced by injection molding of a plastic material, the inconvenience of obstruction of the flow of the plastic material or poor separation from the mold is eliminated, and it is possible to reduce product defects in molding. At the same time, it is possible to avoid the damage of the bearing mounting column caused by the tightening of the screw at the time of assembly, and it is possible to improve the product yield. Further, by eliminating the use of screws as a means for fixing the bearing plate, it is possible to reduce the number of components to be managed and the number of steps in assembling, thereby promoting a reduction in production cost.

In the electric diaphragm device according to the second aspect, a screw is not used as a means for fixing the thin plate-shaped cover to the ground plate, and the cover is deformed due to a variation in the tightening force of the screw, and the diaphragm blade is deformed. Can be avoided, and the product yield can be improved.

Further, the elimination of the use of screws as a means for fixing the cover makes it possible to reduce the number of parts to be managed and the number of steps in assembling, thereby promoting a reduction in production costs. Can also.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an embodiment of an electric throttle device according to the present invention.

FIG. 2 is an exploded perspective view of a conventional electric diaphragm device.

FIG. 3 is an enlarged perspective view of a main part of one embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of one embodiment of the present invention.

FIG. 5 is an explanatory view of mounting the cover according to the embodiment of the present invention;

FIG. 6 is a view as viewed in the direction of the arrow X in FIG. 5;

FIG. 7 is a bottom view of the embodiment of the present invention;

8 is a view as viewed in the direction of the arrow Y in FIG. 7;

[Explanation of symbols]

 23, 29 Rotor shaft 30 Aperture blade drive lever 40, 50 Aperture blade 80 Base plate 83, 84 Bearing mounting column 90 Cover 91 Notch 92 Engagement hole 100 Motor 102 Bearing plate 102b, 102c Recess 830, 840 Locking projection

Claims (2)

(57) [Scope of request for utility model registration] 1. A base plate having an opening for photographing light, an aperture blade provided on one surface of the base plate and changing an opening diameter of the opening by moving on the base plate, A motor attached to the main plate as a driving source for moving operation; and a bearing mounting column for fixing a bearing plate for rotatably supporting a rotor shaft of the motor is provided on the main plate so as to protrude by integral molding. An electric throttle device having a configuration described above, wherein one of the bearing plate and the bearing mounting column is provided with a locking projection, and the other is provided with a concave portion that engages with the locking projection. An electric throttle device wherein the bearing plate is fixed to a bearing mounting column by engagement of a stop projection and a concave portion. 2. A base plate having an opening for photographing light, an aperture blade provided on one surface of the base plate and changing the opening diameter of the opening by moving on the base plate, A thin plate-shaped cover attached to the main plate so as to cover the main plate , wherein the main plate has a width perpendicular to a moving direction of the diaphragm blade.
At both ends of the main plate located at both ends facing
In the width direction perpendicular to the direction of movement of the aperture blade of the bar
Engage so as to hold the end of the cover at both ends
A plurality of engaging fins for restricting the movement of the cover in the thickness direction.
By engaging the flange with the hole provided in the cover,
And an engagement pin for restraining the cover from moving in the surface direction.
The width direction perpendicular to the direction of movement of the aperture blades of the cover
At both ends, the engaging flange of the main plate is
A notch that allows passage in the direction, a flange of the base plate, an engagement pin, and a hole of the cover.
On the main plate so that the cover passes through the notch
When the cover is moved in the surface direction after being brought close,
The end engages the flange, and at the same time, the engaging pin
The cover is fixed to the base plate by engaging the holes of the cover.
An electric diaphragm device, which is arranged so as to be fixed .