JPH05142703A - Fitting structure for molding component, molding component, and sprocket for film unit with lens - Google Patents

Abstract

PURPOSE:To easily assemble the tip fitting part of a sprocket shaft and the sprocket. CONSTITUTION:Slanting surfaces 47 and 52 for insertion guidance are formed in the shaft hole 46 and at the tip fitting part 44a of the sprocket 45. A step surface 65 formed of a metallic mold division surface in the shaft hole 46 is provided more inside than the intersection D of the prolongation B of the shaft hole 46 and the prolongation A of the slanting surface 52. The length of the slanting surface 47 of the tip fitting part 44a of the sprocket shaft 44 is made longer than the distance between the intersection D and the end point E of the slanting surface 52 positioned on the side of the intersection D. Even when the step surface 54 formed of the metallic mold division surface is formed in the shaft hole 46, the insertion of the sprocket shaft 44 is not disable owing to the abutting of its tip on the step surface. Consequently, even if components slightly deviate in axis, the deviation is allowed and the insertion is securely performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fitting structure for molded parts, and more particularly to a fitting structure for a sprocket and a sprocket shaft of a lens-fitted film unit.

[0002]

2. Description of the Related Art A film unit with a lens that has a built-in photo film and a simple shooting function so that you can easily take pictures even when you are not carrying a camera (for example, trade name " This is a photo shoot H
i ") is marketed by the applicant. This lens-fitted film unit needs to be provided at a price that is not so different from the purchase of a normal color film, so that the entire film unit has a simple structure. In addition, a structure is adopted that allows automatic assembly as much as possible so that mass production is possible.

In this lens-fitted film unit, the knob is rotated to wind up the film, and the film transfer force at this time is converted into a rotational force by a sprocket engaging the perforations to charge the shutter mechanism. I am trying. When a film having a length corresponding to one frame is fed, the shutter mechanism restricts the rotation of the sprocket, whereby the unexposed film is set in the exposure frame.

[0004]

The above sprocket has the following problems.
It is located in the sprocket storage recess at a position corresponding to perforation in the film transfer path of the unit main body. The sprocket is formed with a shaft hole in the shape of a square hole, and the tip of the sprocket shaft linked to the shutter mechanism is fitted into the shaft hole. When assembling this sprocket and the sprocket shaft,
First, after loading the sprocket in the storage recess, insert the sprocket shaft from the bearing of the unit body, align the sprocket shaft with the shaft hole of the sprocket, and fit the tip of the sprocket shaft into the shaft hole. There is. Since the sprocket shaft hole is formed of a square hole so that the sprocket shaft does not run idle, there is a problem that it is difficult to align the sprocket shaft for insertion into the shaft hole. In particular, since it is necessary to align the two with the sprocket in the storage recess, it is not possible to visually check the shaft hole, and the work must be done by groping. There is a problem of reduced efficiency. Further, since it is necessary to align the two, there is a problem in performing automatic assembly, and there is a problem that the sprocket cannot be efficiently incorporated in the unit main body.

On the other hand, at the tip of the shaft and the edge of the shaft hole,
It may be possible to facilitate the fitting of the two by forming an inclined surface (tapered surface) and using it as a guide surface for insertion. However, as the sprocket for the lens-fitted film unit, a plastic molded product is used in order to reduce cost and weight. Further, when it is attempted to form the slopes on the front and back of the sprocket in order to allow the sprocket shaft to be inserted regardless of the front and back of the sprocket, as shown in FIG. At one end of the sprocket 1, a step surface 4 which is a split surface of the mold is formed between the inclined surface 2 and the hole edge 3a of the shaft hole 3. Therefore, when trying to insert the sprocket shaft 5 into the shaft hole 3 in a state where the cores of both are displaced, the tip end of the sprocket shaft 5 hits the step surface 4 and the insertion of the sprocket shaft 5 is prevented. Therefore, there is a problem that the sprocket 1 made of a plastic molded product using a mold cannot cope well with automatic assembly.

The present invention is intended to solve the above problems, and when the shafts are inserted into the shaft holes to assemble the molded products, even if the cores are misaligned between them, automatic insertion is possible. It is an object of the present invention to provide a fitting structure for a molded product.

[0007]

In order to achieve the above object, the present invention provides a male fitting component and a female molding component having an insertion hole into which a tip fitting portion of the male fitting component is fitted. In the fitting structure of the molded part, the tip fitting portion and the insertion hole are formed with slopes for guiding these insertions, and the mold dividing surface in the insertion hole Is provided deeper than the intersection of the extension line of the inner surface of the insertion hole and the extension line of the slope, and the slope of the male fitting part is larger than the distance between the intersection and the end point of the slope located on the intersection side. Is formed long.

The present invention is also applied to a molded part for inserting an insertion part having a tapered tip. In this case, a sloped surface that guides the tip of the insertion part is formed at the opening edge of the insertion hole provided in the molded part, and a stepped portion having an inner diameter larger than that of the insertion hole is provided at the back of the sloped part to increase the length of the sloped part. The length is made shorter than the inclined surface of the tip of the insertion part, and the step surface that connects the step portion and the inner surface of the insertion hole is aligned with the dividing surface of the molding die of this molding part.

Further, when a sprocket for a lens-fitted photo film unit is used as the molded component and the drive shaft for transmitting the rotation of the sprocket to the shutter charge mechanism is the inserted component, the assembly is simplified. For this purpose, it is advantageous to penetrate the insertion hole of the drive shaft into the front and back of the sprocket so that the drive shaft can be inserted from both the front and the back, and for this reason, a sloping surface for guiding is formed at each opening edge. .. In order to integrally form a guiding slope on each of the opening edges, the dividing surface of the molding die is inside the insertion hole. However, in the present invention, a step portion having an inner diameter larger than the insertion hole is formed at the back of one slope. Is formed so that the length of the inclined surface is shorter than that of the tip of the insertion part, and the stepped surface connecting the stepped portion and the inner surface of the charging hole is aligned with the dividing surface of the molding die.
Therefore, regardless of whether the drive shaft is inserted from the front side or the back side of the sprocket, the insertion work can be easily performed without being affected by burrs or the like generated during molding.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 shows a lens-fitted film unit (hereinafter, simply referred to as a film unit) embodying the present invention. The film unit 10 is composed of a unit main body 11 having a photographing mechanism and an outer case 12 for accommodating the same, and a photograph is taken with the outer case 12 kept in the case. The outer case 12 is a film unit 1
This is to make the appearance of 0 clean, and uses a paper box with the outer surface printed. The outer case 12 has a taking lens 13, an objective side finder window 14, an eyepiece side finder window 15, a shutter button 16, and a photographing number display plate 1.
7, holes for exposing the winding knob 18, and the strobe light emitting portion 19 are provided.

FIG. 4 shows the unit main body 11. The unit body 11 includes a body portion 20, a front cover 21,
And a rear cover 22. On the front surface of the body portion 20, a shutter unit 25 in which the taking lens 13 is arranged and a strobe unit 26 holding the light emitting portion 19 are provided. Further, a cartridge chamber, an exposure chamber, and a film chamber (not shown) are formed on the back surface side of the main body portion 20 from the left side in the drawing, and the film with a cartridge 23 is loaded on the back surface side of the main body portion 20. Rear cover 2 in this state
2 is detachably attached to the main body portion 20 by a claw.
The rear cover 22 is provided with a bottom lid 24 which can be opened and closed so as to take out the cartridge in which the film is wound after the photographing is finished. The film transfer path 27 is located at a position where the perforations 23a of the film 23 pass.
A sprocket escape recess 27a is formed.

Referring to FIG. 5 showing the shutter unit 25, the shutter unit base 3 having an exposure opening 28 is shown.
No. 0 has a positioning hole 31 for positioning when it is attached to the main body 20, and claw receiving portions 30a and 30b integrally formed on both sides of the exposure opening 28. The shutter unit base 30 has a plastic shutter blade 34 which is urged counterclockwise by a spring 33.
Is rotatably pivoted, and a shutter cover 35 for holding the taking lens 13 is attached to the shutter unit base 30 so that the shutter blades 34 do not fall off.

Shafts 30c and 30d and a bearing 30e are formed on the shutter unit base 30. A shaft 30c is provided with a photograph number display plate 38 and a shutter drive cam 39 having a shutter drive lever 39a, and a shaft 30d is provided with a locking lever 41 rotatably screwed by a spring 40 in a clockwise direction. Has been done. The locking lever 41 is normally engaged with the shutter drive lever 39a biased counterclockwise by the spring 40 to prevent the shutter drive cam 39 from rotating, and the shutter button (see FIG. 3).
(See) 16 is pressed, shutter drive lever 39a
To disengage from. When the shutter drive lever 39a is disengaged from the locking lever 41, the shutter drive lever 39a is rotated counterclockwise by the spring 40, and the arcuate pressing surface 39b formed on the shutter drive lever 39a is clawed on the shutter blade 34. The portion 34a is pressed.

A sprocket shaft 44 which is a shaft of a cam 43 which engages with the locking lever 41 is inserted through the bearing 30e. The sprocket shaft 44 is fitted into the shaft hole 46 of the driven sprocket 45 via the tip fitting portion 44a. Therefore, the film winding knob 18 (see FIG.
When the film is wound up by rotating the cam arm 39c formed on the shutter drive cam 39, the sprocket 45 rotates counterclockwise, and the cam 43 also rotates counterclockwise. The shutter drive lever 39a returns to the initial position via the
8 rotates one scale.

As shown in FIG. 6, the sprocket shaft 4 is
A chamfered slope 47 is formed on the tip end fitting portion 44a of No. 4. The inclined surface 47 is formed as a conical surface by chamfering the tip in a conical shape, and serves as a guide surface when the tip fitting portion 44 a is inserted into the shaft hole 46 of the sprocket 45. The sprocket shaft 44 is integrally rotated by the rotation of the sprocket 45, and is used as a drive shaft for driving the shutter charge mechanism and the counter mechanism by the rotation of the sprocket 45.

The driven sprocket 45 is formed with a disc 50 for alignment on both end faces thereof so as to project concentrically with the shaft hole 46. Further, as shown in FIG. 7, chamfered slopes 51 and 52 are formed at the opening edges at both ends of the shaft hole 46. The driven sprocket 45 is manufactured by injection molding using a mold, as is well known. Therefore, as shown in FIG. 2, conventionally, a step surface 4 is formed on one of the slopes 2 by the dividing surface of the molding die. The step surface 4 was formed between the edge of the shaft hole 3 and the slope 2 so that burrs at the time of molding do not occur in the direction orthogonal to the center line CL1 of the shaft hole 3. In the invention, as shown in FIG.
A step portion having an inner diameter larger than that of the shaft hole 46 is formed in the inner side of the shaft hole, and a step surface 54 serving as a split surface is formed on the inner side of the intersection D between the extension line A of the slope 52 and the extension line B of the inner surface of the shaft hole 46. It is set. In addition, the length of an extension line A (line segment DE) connecting the end point E on the far side of the slope 52 and the intersection point D is defined by the sprocket shaft 44.
The length is set shorter than the length of the slope 47 of the tip fitting portion 44a.

As a result, as shown in FIG. 7, even when the center line CL1 of the sprocket 45 and the center line CL2 of the sprocket shaft 44 do not coincide with each other and are displaced by the displacement amount Δ, the tip end 44b of the sprocket shaft 44 remains. The sprocket shaft 44 can be smoothly inserted into the sprocket 45 because it is guided into the shaft hole 46 without hitting the step surface 54. At this time, the allowable deviation amount Δa is the heights C1 and C of the two slopes.
The sum of 2 is less than C1 + C2, and the allowable amount is increased by C2 as compared with the conventional case shown in FIG. 2, and even if the misalignment amount is increased, this can be dealt with.

As shown in FIG. 6, the driven sprocket 45 is
Is inserted into a sprocket housing recess 60 that is recessed on the back side of the shutter base 30. Sprocket storage recess 60
Is composed of an arc-shaped groove having an inner diameter slightly larger than the outer diameter of the sprocket 45. The sprocket housing recess 60 is provided with a driven sprocket 4 inside the recess 60.
5, when the tooth 45a of the sprocket 45 is slightly projected from the film transfer path 27 (see FIG. 3), it is formed with a depth to engage with the perforation 23a of the film 23 passing through the film transfer path 27. There is. The sprocket housing recess 60 is provided with a positioning disc 50 when the sprocket 45 is inserted into the housing recess 60.
Guide groove 6 in which the positioning disk 50 is inserted at a position corresponding to
1 is provided. A semicircular positioning groove 62, which is concentric with the shaft hole 46 and has substantially the same diameter as the disk 50, is provided in the innermost portion of the guide groove 61. Further, the edge 60a of the storage recess 60 is formed as a slope 60a that gradually opens toward the outside, so that the sprocket 45 can be easily inserted into the storage recess 60.

Next, the sprocket 45 is accommodated in the recess 6
0, and the end fitting portion 4 of the sprocket shaft portion 44
The assembling work for inserting the 4a into the shaft hole 46 of the sprocket 45 will be described. First, as shown in FIG. 6, the sprocket 45 is inserted into the storage recess 60. At the time of this insertion, since the slope 60a serves as a guide, the sprocket 45 can be easily inserted into the recess 60. In the recess 60, the disk 50 is positioned by the positioning groove 62, so that the shaft hole 65 of the bearing 40e of the shutter base 30 and the shaft hole 46 of the sprocket 45 are aligned with each other. In this state, when the sprocket shaft 44 is inserted into the shaft hole 65 and the sprocket 45 is rotated, the tip fitting portion 44 a of the sprocket shaft 44 and the shaft hole 4 of the sprocket 45 are rotated.
When 6 and 6 match, the tip fitting portion 44a is easily inserted into the shaft hole 46. At this time, as shown in FIG. 7, the sloped surface 52 of the shaft hole 46 and the sloped surface 47 of the tip fitting portion 44a serve as a guide during insertion. Therefore, even if the sprocket shaft 44 is inserted into the shaft hole 46 with the core misaligned, the tip fitting portion 44a moves while being guided by the inclined surface 52, so that the tip end does not hit the step surface 54 and the insertion is performed. Is easily done.

The operation of the lens-fitted film unit thus configured will be described. When the shutter button 16 is pressed, the locking lever 41 is pressed in conjunction with this as shown in FIG. As a result, the locking lever 4
1 moves, and the shutter drive lever 39a disengaged by this movement is rotated counterclockwise from the initial position by the spring 40. The pressing surface 39b engages with the pawl portion 34a and presses the pawl portion 34a, thereby instantaneously rotating the shutter blade 34. As a result, the claw portion 34a is pressed rightward, so that the shutter blade 34 is rotated clockwise and the exposure opening 28 is opened. Thereafter, when the shutter blade 34 is further rotated clockwise, the pressing surface 39b is released from the engagement with the claw portion 34a. When this engagement is released, the shutter blades 34 are rotated counterclockwise by the springs 33, returned to the position where the exposure opening 28 is closed, and the photographing is completed. The shutter drive lever 39a is used for the cam arm 3
When 9c contacts the cam 43, its rotation is stopped.

After the photographing is completed, the winding knob 18 is rotated, and when the film 23 is wound in the cartridge, the driven sprocket 45 is rotated counterclockwise through the perforations 23a. This causes the cam 43 to move to the spring 4.
It rotates counterclockwise against the bias of 0 and rotates the shutter drive lever 39a clockwise. If the shutter drive lever 39a comes into contact with the claw portion 34a during this rotation, the shutter drive lever 39a is deformed upward and gets over this. Then, when the shutter drive lever 39a is returned to the initial position and the shutter charge is performed, the next shooting preparation is completed.

In the above embodiment, the present invention is applied to the fitting structure of the sprocket 45 of the lens-fitted photo film unit and the sprocket shaft 44 inserted therein. When inserting a male fitting member such as a shaft into the inside, the dividing surface of the molding die must be positioned on the slope of the hole or recess due to restrictions such as the direction of pulling out the molding part and the molding die. The present invention can be applied to any situation. Further, the shaft hole is not limited to a square hole, but may be a round hole.

[0023]

As described above, according to the present invention,
When fitting the sprocket and its molded parts such as its shaft, the mold dividing surface in the insertion hole is more than the intersection of the extension line of the inner surface of the insertion hole and the extension line of the slope. Since the slope of the male fitting part is formed longer than the distance between this intersection and the end of the slope located on the side of the intersection, even if a step due to the mold dividing surface occurs in the shaft hole. The step prevents the tip of the male fitting component such as the shaft from hitting and becoming impossible to insert. As a result, even if a slight misalignment occurs between the two parts in the automatic assembly, the misalignment can be allowed and the insertion can be reliably performed.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a main part of a fitting structure of a sprocket and a sprocket shaft embodying the present invention.

FIG. 2 is a sectional view showing a state in which a sprocket shaft is inserted into a conventional sprocket.

FIG. 3 is a perspective view showing the outer appearance of a lens-fitted film unit.

FIG. 4 is an exploded perspective view showing a unit main body.

FIG. 5 is an exploded perspective view showing a shutter unit.

FIG. 6 is a perspective view showing a state in which a sprocket is installed in a sprocket storage recess.

FIG. 7 is a sectional view showing a state in which the sprocket shaft is inserted into the sprocket of the present invention.

[Explanation of symbols]

 44 sprocket shaft 44a tip fitting part 45 driven sprocket 46, 65 shaft hole 47, 51, 52 slope 50 disk 60 sprocket storage recess 61 guide groove 62 positioning groove

Claims (3)

[Claims] 1. A male fitting component and a female molding component having an insertion hole into which a tip fitting portion of the male fitting component is fitted, the mounting being performed by fitting the tip fitting portion and the insertion hole. In a fitting structure of a molded part in which a sloped surface is formed to guide these insertions, the mold dividing surface in the insertion hole is defined by an extension line of the hole inner surface of the insertion hole and an extension line of the sloped surface. A fitting structure for a molded part, characterized in that it is provided at a position deeper than the intersection with and the slope of the male fitting is formed longer than the distance between the intersection and the end point of the slope located on the side of the intersection. 2. A molded part having an insertion hole for inserting an insertion part having a tapered bevel at the tip, which serves as a guide when the tip of the insertion part is received at the opening edge of the insertion hole. In addition to forming a slope, a step portion having an inner diameter larger than that of the insertion hole is provided at the back of the slope to make the length of the slope shorter than the slope of the tip of the insertion part, and connect the step portion and the inner surface of the insertion hole. A molded part characterized in that the step surface is matched with the dividing surface of the molding die of this molded part. 3. An injection-molded product, wherein a pawl that engages with film perforation is integrally formed on the outer periphery, and a fitting hole for fitting a drive shaft for driving the shutter charge mechanism is formed in the central portion. In a sprocket for a lens-fitted film unit that rotates following the feeding of the film and charges the shutter via the drive shaft, the fitting hole is passed through the front and back, and the drive shaft is inserted into each opening edge. An insertion guide is formed by forming a sloped surface that serves as a guide surface when performing Shorter than the slope for
A sprocket for a lens-equipped film unit, wherein a step surface that connects the step portion and the inner surface of the fitting hole is matched with a split surface of the sprocket molding die.