JPH03200234A - Diaphragm device - Google Patents

Abstract

PURPOSE:To reduce the cost of a device by forming a plate-like material in a cylindrical body by roll forming, etc., and providing a yoke which forms a coupling part or an abutting part by mechanical engagement on the peripheral surface of the cylindrical body. CONSTITUTION:The yoke 7-2 is constituted as the cylindrical body provided with a joint which is obtained by forming the plate-like material in the cylindrical body, and the coupling part (or the abutting part) 7-2A consisting of two opposed edges which have complementary shapes each other is formed on the peripheral surface of the cylindrical body. Then, the coupling part (or the abutting part) 7-2A in the yoke 7-2 is constituted of a recessed part 7-2B and a tongue piece 7-2C fitting in the recessed part 7-2B, and the coupling part (or the abutting part) 7-2A is constituted by mechanical engagement or mutual fitting not by permanent fixing method such as welding or adhesion. Thus, a low-prices diaphragm device is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an aperture device installed in an optical device such as a video camera.

[Conventional technology]

An electric aperture device installed in a video camera or the like has a structure as shown in FIG. 7, for example. In FIG. 7, 1 is the main plate of the aperture device, 2 and 3 are a pair of aperture blades arranged to move on the aperture blade arrangement surface la of the main plate 1, and 4 is the groove 2a of the aperture blades 2 and 3; A diaphragm blade drive lever that has bins 4a and 4b at both ends that are inserted separately into the diaphragm blade drive lever 3a and rotates around a boss 4C.
Reference numeral 5 denotes a motor whose shaft 5-1 is fitted into the shaft hole 4d of the boss 4c of the lever 4. In this known electric aperture device, when the shaft 5-1 of the motor 5 is rotated within a predetermined angle range, the aperture blades 2 and 3 are moved to the aperture blade arrangement surface 1' of the base plate 1 via the aperture blade drive lever 4. Move on a and move to the main plate 1
The opening area of the optical path hole 1b is increased or decreased.

In FIG. 7, reference numerals 1c and 1d are guide bins inserted into the long grooves 2b and 2c of the aperture blade 2 to guide the linear movement of the aperture blade 2.

As shown in FIG. 7(b), the motor 5 includes a cylindrical yoke 5-2. A pair of coil bobbins 5-3 and 5 housed in the yoke 5-2 and fixed to the main plate 1.
-4. Stator coils 5-5 and 5-6 are wound in coil winding grooves of coil bobbins 5-3 and 5-4, respectively. A permanent magnet rotor 5-7, which is rotatably arranged between opposing surfaces of the coil bobbins 5-3 and 5-4 and is integrally formed with the shaft 5-1. The motor end plate 5-82 is fitted into one end of the yoke 5-2 and has a bearing hole 5-88 for the shaft 5-1.
-2 is such that the base plate 1 yoke support is fixed to the part.

In the known aperture device as described above, the yoke 5-2 of the motor 5 has conventionally been manufactured by the following method. That is, the yoke 5-2 is manufactured by roll-forming a strip-shaped flat plate material to form a cylindrical body, then seam welding the peripheral surface of the cylindrical body to join the rice grains, and then cutting the cylindrical body. Ta.

However, the yoke manufactured by the above manufacturing method is relatively expensive in terms of manufacturing cost.
Furthermore, the conventional motor 5 has a capacity greater than that required for the diaphragm, so it was not preferable from a cost performance standpoint. In other words, as mentioned above, conventional yokes manufactured using the same manufacturing method as seam welded pipes require annealing to relieve stress at the seam weld, which takes time to manufacture, and requires additional manufacturing equipment. It also costs a lot of money. In addition, the conventional motor as described above is capable of continuous rotation of 360°C or more, but in general, the rotation angle range of the rotor of the motor may be narrow in the throttle device as described above, so the conventional motor is not necessary. It can be said that it has more functions than those described above. Therefore, there has been a problem in that the cost of the motor in the conventional aperture device is higher than the cost commensurate with the function required to drive the aperture blades.

An object of the present invention is to have the minimum functions necessary for driving the aperture blades and to be able to manufacture the device at a lower cost than conventional devices. An object of the present invention is to provide an improved diaphragm device.

[Means to solve the problem]

In the aperture device according to the present invention, the yoke of the motor for driving the aperture blades is configured as a jointed cylinder having a butt portion or a joint portion on the circumferential surface, and the butt portion or the joint portion is formed by bonding or welding. It is characterized in that it is constructed by a mere mechanical engagement relationship without using the complete fixing method. The yoke of the drive motor of the drawing device of the present invention can be manufactured by punching and roll forming, so it can be manufactured without the need for seam welding equipment or annealing equipment, and it can be manufactured in a shorter time than conventional yoke manufacturing methods. You can manufacture yokes.

Therefore, the aperture device according to the present invention is lower in cost than the conventional device, and has performance suitable for driving the aperture blades.
It has optimal cost performance.

(Embodiment) An embodiment of the aperture device of the present invention will be described below with reference to FIGS. 1 to 6. Components in FIGS. 1 and 3 that are designated by the same reference numerals as in FIG. 7 are the same as the components of the conventional diaphragm shown in FIG. 7, and therefore their explanations will be omitted.

In FIG. 1, 7 is a motor, and 6 is a printed wiring board for a drive circuit of the motor 7.

As shown in FIG. 1(a), the yoke 7-2 is a cylindrical yoke 7-2. A pair of coil bobbins 7-3 and 7-4 housed in the yoke 7-2 and fixed to the coil bobbin fixing rods 1f and 1g of the main plate 1, the coil bobbin 7
- Stator coils 7-5 and 7-6, coil bobbins 7-3 and 7, wound in the coil winding grooves of -3 and 7-4, respectively.
A rotor-7 made of a permanent magnet, which is arranged between opposing surfaces of -4 and whose shaft 7-1 is inserted into the shaft hole 1e of the main plate 1;
It is composed of various parts. In addition, yoke 7-2
The cylindrical yoke support protruding from the main plate 1 is installed on the part lh, and the motor end plate 7-8 is screwed into the holes made at the tips of the coil bobbin fixing rods if and 1g by screws 81 and B2. are coil bobbin fixing rods 1f and 1
It is designed to be attached to g. In addition, screw holes 1k and 1fL are drilled at the ends of the pillars 1i and 1j that protrude from the base plate 1, respectively, and by screwing screws B3 and B4 into the screw holes, a printed wiring board 6 for the motor circuit is formed. is fixed to the pillar.

The yoke 7-2 is constructed as a jointed cylindrical body formed from a flat material into a cylindrical shape, and the cylindrical body has a joint portion ( or abutting portion) 7-2A is formed. In the yoke 7-2 of this embodiment, as shown in FIG. 1(b), the joint portion (or butt portion) 7-2A
is a recess 7-2B and a tongue piece 7-2 that fits into the recess 7-2B.
0, and the joint part (or butt part) 7-2A is constructed by mechanical engagement (or mutual fitting) without using a permanent fixing method such as welding or gluing. .

Therefore, since there is a minute gap between the surfaces a and b of the recess 7-2B and the tongue 7-2C (that is, the surfaces parallel to the axis of the yoke 7-2), the magnetic flux φ generated within the yoke 7-2 On the other hand, the air gap becomes a magnetic resistance, and the torque T generated by the rotor 7-7 in the range X where the joint portion 7-2 is affected becomes the minimum as shown in FIG. Therefore, in the aperture device of the present invention, the joint portions 7-28 are arranged at a position unrelated to driving the aperture blades, at the original stop position of the rotor, or at a position between the coils (a position between the coil bobbins). In this case, the joint part 7-28 is connected to the yoke 7-2 as shown in FIG.
It is arranged between two magnetic closed paths C1 and C2 formed across the coil bobbin and the coil bobbin (that is, the position between the coil bobbins). Note that the aperture blade drive range may be set to avoid the range X where the joint portion 7-2 is affected.

As described above, in the aperture device of the present invention, the aperture blade drive range is set to a range that does not include the range X, so the motor 7 of this embodiment is not suitable for rotation at 360°C, but As a source, it exhibits the same performance as the motor 5 of a conventional throttling device.

On the other hand, in the yoke two 2 of this embodiment, a notch 7-2D is formed in the end face of the yoke within the range It is designed so that the 1m piece fits into it. That is,
The protruding piece 1m and the notch 7-2D constitute yoke positioning means for the yoke support portion 1h of the base plate 1. In this embodiment, the protruding piece 1m is located between the coil bobbins,
As shown in FIG. 3, it is located between two magnetic closed circuits C1 and C2 formed across the yoke 7-2 and the coil bobbin.

As explained in the above embodiment, the motor installed in the drawing device of the present invention forms a flat material into a cylindrical body by roll forming or the like, and forms a joint by mechanical engagement with the circumferential surface of the cylindrical body. Alternatively, since it has a yoke with a rice grain joint formed therein, it can be manufactured at a lower cost than a conventional motor having a welded yoke. A throttling device can be provided.

4 and 5 show modified embodiments of the yoke.

The yoke 7-9 shown in FIG. 4 has a joint portion 7-98 consisting of a serrated locking edge, and the end surface of the yoke 7-9 adjacent to the joint portion 7-98 has a positioning portion. Notch 7-9D
is formed.

The yoke 7-10 shown in FIG. 5 has only one complementary device mating part constituting the joint part 7-10A, and this yoke 7-10 also has a yoke positioning cutout adjacent to the joint part 7-10A. It has a cutout 7-10D.

It is clear that the yoke 7-10 shown in FIGS. 4 and 5 constitutes a motor with substantially the same characteristics as the yoke 7-2 (see FIG. 2).

FIG. 6 shows a yoke 7-11 in which a joint portion 7-11A is formed substantially spirally around the entire circumference. This yoke 7-11 does not produce a large magnetic resistance only within a narrow range of the circumferential surface like the yokes of the previous embodiments, but the 611 magnetic resistance is almost the same along the yoke axis; A large range of is shifted in the axial direction.

Therefore, the yoke 7-11 of this embodiment does not constitute a motor with the characteristics as shown in FIG. 6, but constitutes a motor with the same characteristics as the conventional motor, so it is necessary to provide a positioning notch like the yoke described above. There is no.

(Effects of the Invention) As explained in the above embodiment, the motor installed in the drawing device of the present invention forms a flat material into a cylindrical body by roll forming or the like, and mechanically engages the surface of the cylindrical body. Since it has a yoke with a welded joint or abutment, it can be manufactured at a lower cost than a motor with a conventional welded yoke, and is therefore more cost-effective and less expensive than a conventional throttling device. A cost-effective throttling device can be provided.

[Brief explanation of drawings]

FIG. 1(a) is an exploded perspective view of essential parts of the throttle device of the present invention, FIG. 1(b) is an enlarged view of the yoke of the motor included in the throttle device, and FIG. 2 is the same as that of FIG. 1(b). A diagram showing the relationship between the torque of a motor having a yoke and a joint part of the yoke, FIG. 3 is a diagram showing the relative positional relationship of the yoke within the motor, and FIG. 4 is a diagram showing a second embodiment regarding the yoke. 5 is a diagram showing the third embodiment regarding the yoke, FIG. 6 is a diagram showing the fourth embodiment regarding the yoke, and FIGS.
Figure (b) is an exploded perspective view of a conventional throttle device. 1... Main plate 2.3... Aperture blade 4...
Aperture blade drive lever 5...Motor 6...Printed wiring board 7...
・Motor 7-2...Yoke 7-2A...
Joint part 7-2D...Positioning notch 7-9 7-10 7-11...Yoke Figure 1 (a) Other 4 people Figure 4 Ugi Figure 5 Figure 6

Claims (1)

[Claims] 1. In a throttle device equipped with a drive source composed of a stator coil, a rotor with magnets, and a yoke, the yoke is configured as a cylinder having a butt portion or a joint portion on the circumference. and that the abutting part or the joint part is constructed by mere mechanical engagement, mechanical fitting, jigsaw fitting, etc., without using a permanent fixing method such as adhesive or welding. Features a diaphragm device. 2. The aperture device according to claim 1, wherein the butt portion or the joint portion includes a portion parallel to the axis of the yoke and a portion non-parallel to the axis of the yoke. 3. Claim 1, wherein a portion of the abutment portion or the joint portion that maximizes the magnetic resistance in the yoke is located corresponding to the original stop position of the rotor or the position between the stator coils. The aperture device described.