JP3340543B2 - Cylindrical molded body, mold for cylindrical molded body, and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical molded body, a mold for the cylindrical molded body, and a method for producing the same.

[0002]

2. Description of the Related Art A zoom lens barrel is provided with various rotating cylinders for performing zooming and focusing. In a zoom lens barrel which is being developed by the present applicant, during rotation, first and second cylindrical members located on the inner peripheral side thereof are advanced and retracted in the optical axis direction, and the first and second cylindrical members are moved. A rotating cylinder that transmits rotation to the member is used. The rotating cylinder advances and retreats the first cylindrical member in the direction of the optical axis when rotating, and the gear and the like move in the optical axis direction together with the first cylindrical member by an internal gear formed on the inner peripheral surface. To the second cylindrical member.

By the way, if the internal gear is formed on the entire inner peripheral surface of the rotary cylinder, it becomes impossible to form another cam groove or the like on the inner peripheral surface. For this reason, the emergence of a rotating cylinder having an internal gear of a more appropriate shape has been desired. Further, there is a long-felt need for a mold and a method for manufacturing the same, which can easily mold a rotary cylinder having such an internal gear using a resin material.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cylindrical molded body having a more suitable internal gear based on the above problem awareness. Another object of the present invention is to provide a molding die for molding the cylindrical molded body and a method for producing the cylindrical molded body.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a helical internal gear that is inclined with respect to a circumferential direction on an inner peripheral surface of a cylindrical molded body of a resin material; A feature is that a spiral relief groove wider than the tooth width of the internal gear is formed.

[0006] The present invention also relates to a molding die for molding a cylindrical molded body, comprising an upper mold for forming an outer surface of the cylindrical molded body, and a lower mold for forming an inner surface of the cylindrical molded body. A first cylindrical mold portion having a spiral tooth shape portion corresponding to the internal gear; and a second cylindrical mold portion having a spiral flat surface portion corresponding to the relief groove.

Further, the present invention relates to a molding die for molding a cylindrical molded body having a spiral lead groove parallel to an internal gear on an inner peripheral surface thereof, wherein an upper mold for forming an outer surface of the cylindrical molded body. And a lower mold forming an inner surface, and the lower mold has a first cylindrical mold portion having a spiral tooth shape portion corresponding to the internal gear; and a spiral flat surface portion corresponding to the clearance groove. A second cylindrical mold portion having;
And a helical projection corresponding to the lead groove of the second cylindrical mold portion.

The present invention also relates to a method of manufacturing a cylindrical molded body, wherein the first cylindrical body has a spiral tooth mold portion corresponding to an internal gear, which is an upper mold forming an outer surface of the cylindrical molded body. A second cylindrical mold portion having a mold portion and a spiral flat portion corresponding to the clearance groove,
And a first step of combining a lower mold forming the inner surface of the cylindrical molded body; a second step of injecting a resin material into a space formed by the upper mold and the lower mold; when the resin material in the space is cured A third step of rotating the second cylindrical mold part to separate from the upper mold; moving the first cylindrical mold part in the axial direction to separate the tooth form part from the internal gear and position the tooth form part in the clearance groove; 4 steps; and a fifth step of rotating the first cylindrical mold portion to separate from the upper mold.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. In the zoom lens barrel of the present embodiment of the camera, the front lens unit L1 and the rear lens unit L2 constitute a zoom lens system, and focusing is performed by the front lens unit L1.

As shown in FIGS. 7 and 8, a fixed lens barrel 11 integrated with a camera body 10 of a camera to which the present invention is applied has an inner cylinder 11a and an outer cylinder 11b. The rear ends of the inner cylinder 11a and the outer cylinder 11b in the optical axis direction are connected by a connection wall 11c, and the front end is open. From this open end, the rotary cylinder 12 is rotatable around the inner cylinder 11a. It is fitted. The inner cylinder 11a is provided with a straight guide groove 11e in a direction parallel to the photographing optical axis O.

The cylindrical molded body, that is, the rotary cylinder 12, which is a feature of the present invention, is made of a synthetic resin material. As shown in FIG. 9, a circumferential spur gear 12a is integrally provided on the outer periphery thereof, A fine screw 12b is formed integrally with the outer periphery of the tip. On its inner surface, a spiral lead groove 12c inclined in the circumferential direction, a spiral inclined inner gear (internal gear) 12d parallel to the lead groove 12c and inclined with respect to the circumferential direction, A spiral relief groove 12e having a diameter larger than the root circle of the inclined inner gear 12d and wider than the tooth width and adjacent to the inner gear 12d is formed.

At the open front end of the inner tube 11a and the outer tube 11b of the fixed lens barrel 11, a fitting portion 13a with the inner surface of the outer tube 11b is provided.
A screw portion 13b screwed to the fine screw 12b;
A contact portion 13c contacting the outer surface of the outer flange 1a;
A support ring 13 having 3e is fixed. The support ring 13 is pressed toward the fixed lens barrel 11 by an urging means (not shown) and is held at a fixed position. 13d
Is a gear for rotating operation formed on the outer peripheral surface of the support ring 13. With this support ring 13, it is possible to eliminate insufficient strength at the openings of the inner cylinder 11a and the outer cylinder 11b.

A spur gear 1 is provided on the outer cylinder 11b of the fixed lens barrel 11.
A notch 11d for the pinion 11f that meshes with 2a is provided, and a similar notch that exposes the lead groove 12c and the inclined inner gear 12d (FIGS. 1 and 2) is provided in the inner cylinder 11a.

A first advance / retreat cylinder 14 that moves straight in the optical axis direction is fitted on the inner periphery of the inner cylinder 11a of the fixed lens barrel 11. On the outer periphery of the first advancing / retreating cylinder 14, a rectilinear guiding projection 14a which fits into the rectilinear guiding groove 11e of the fixed lens barrel 11 is integrally provided.
Pin 14b that fits into the second lead groove 12c (FIGS. 1 and 2)
Is provided. A female helicoid 14c and a straight guide groove 1 parallel to the optical axis are provided on the inner circumference of the first advance / retreat cylinder 14.
4d (FIGS. 1 and 3) are formed. According to the above relationship, when the rotary cylinder 12 is rotationally driven, the straight guide groove 1
According to 1e and the lead groove 12c, the first advance / retreat cylinder 14 advances / retreats in the optical axis direction without rotating.

On the inner periphery of the first advance / retreat cylinder 14, there is provided the second advance / retreat cylinder 1
5 is fitted. A male helicoid 15a that is screwed to the female helicoid 14c of the first advance / retreat cylinder 14 is formed at the rear of the outer periphery of the second advance / retreat cylinder 15 in the optical axis direction. A rectilinear guide member 16 is located on the inner periphery of the second reciprocating cylinder 15, and a gear support and rectilinear guide plate 17 is fixed to a rear end of the rectilinear guide member 16 with a fixing screw 19. An inner flange 1, which is rotatably held between the rectilinear guide member 16 and the rectilinear guide plate 17, is provided on the second reciprocating cylinder 15.
5b (see FIGS. 7 and 8) are formed. Further, a plurality of linear guide keys 1 formed on a peripheral portion of the linear guide plate 17.
7a is fitted in the straight guide groove 14d of the first advance / retreat cylinder 14. Therefore, the linear guide member 16 and the linear guide plate 17
Is rotatable relative to the second advance / retreat cylinder 15 and moves integrally in the optical axis direction. That is, when the second advance / retreat cylinder 15 rotates, it moves in the optical axis direction while rotating according to the male helicoid 15a and the female helicoid 14c, while the straight guide member 16 and the straight guide plate 17 do not rotate. It moves in the optical axis direction together with the binary retraction cylinder 15.

As shown in FIG. 1, the linear guide member 1
6 has three rectilinear keys 16b and 16b 'extending in a direction parallel to the photographing optical axis O. The front group rectilinear guide member 18 includes three rectilinear keys 18a that engage with the three rectilinear keys 16b and 16b 'and extend in a direction parallel to the photographing optical axis O. The front group straight guide member 18 includes
The shutter block 20 is fixed by the fixing screw 21,
The shutter block 20 further includes a front lens support cylinder 22.
Therefore, the rotation of the shutter block 20 and the front lens group support tube 22 is restricted, and only the movement in the optical axis direction is possible.

As shown in FIGS. 1 and 4, the shutter block 20 has a female helicoid 20a at the shaft thereof, and the male lens of the lens support ring 23 in which the front group lens L1 is fixed to the female helicoid 20a. Helicoid 23a is screwed. The lens support ring 23 forms a front lens frame 45 with a lens press ring 40 screwed to the front end thereof.
A male helicoid 22a for moving the lens support ring 23 in the optical axis direction during zooming is formed at the rear end of the outer peripheral surface of the front lens support cylinder 22. The shutter block 20 has a shutter blade 20c, and a drive signal is supplied to the shutter block 20 via an FPC board 20d.

On the other hand, the front group straight guide member 18 is formed with a rear group guide surface 18b for moving the rear group lens L2 straight in the optical axis direction. The rear group lens L2 is fixed to the rear group lens frame 24.
Then, the rectilinear key 24a engaged with the rear group guide surface 18b
Is provided. And on this straight key 24a,
A cam pin 24b is formed to protrude.

A female helicoid 15c for screwing a male helicoid 22a of the front group lens support cylinder 22 onto the inner peripheral surface of the second advance / retreat cylinder 15 and a cam pin 24 of the rear group lens frame 24
and a cam groove 15d into which the b is inserted. The cam groove 15d is mixed with the helicoid at the same circumferential position so as to cut off a part of the female helicoid 15c. At the time of assembly, the cam pin 24b of the rear lens frame 24 is fitted into the open groove 22b at the rear end of the front lens support cylinder 22, and in this state, the cam pin 24b is inserted into the cam groove 15d, the male helicoid 22a is inserted into the female helicoid 15c, Each is engaged. In this engaged state, the female helicoid 15 c and the male helicoid 22 c
a and the straight key 16 of the straight guide member 16
Due to the rectilinear guide relationship between b and the rectilinear key 18a of the front group rectilinear guide member 18, the front lens support cylinder 22 (front lens L1) moves rectilinearly in the optical axis direction, and the engagement between the cam groove 15d and the cam pin 24b. The rear group lens frame 24 is formed based on the mating relationship and the straight guide relationship between the straight key 24a of the rear group lens frame 24 and the rear group guide surface 18b of the front group straight guide member 18.
(The rear lens group L2) moves along a predetermined locus in the optical axis direction,
Zooming is performed.

As described above, when the rotary barrel 12 is rotationally driven, the first advance / retreat barrel 14 moves straight in the optical axis direction, and when the second advance / retreat barrel 15 rotates with respect to the first advance / retreat barrel 14, the first advance / retreat barrel 15 rotates. It can be seen that the binary retreat cylinder 15 moves in the optical axis direction while rotating, and the front lens group L1 and the rear lens group L2 move straight while changing the air gap, thereby performing zooming.

Next, a drive mechanism for rotating the second advance / retreat cylinder 15 will be described. This rotation drive mechanism basically transmits the rotation of the rotary cylinder 12 to the second advance / retreat cylinder 15. A pair of gear support plates 26 and 27 are fixed to the rear end of the first advancing / retreating cylinder 14 by fixing screws 29. The gear support plate 26 rotatably supports a pinion 30 (see FIGS. 5 and 6) that meshes with the inclined inner gear 12 d of the rotary cylinder 12. The first advance / retreat cylinder 14
A plurality of linear guide keys 14a formed in the circumferential direction at the rear end
The pinion 3 is located between the two straight guide keys 14.
A linear guide protrusion 14a '(FIG. 3) having a pinion storage space 14e for storing the 0 is formed. A part of the tooth surface of the pinion 30 stored in the pinion storage space 14 e protrudes from the outer surface of the first advance / retreat cylinder 14. Rotating cylinder 12
The inner gear 12d (FIG. 2) is parallel to the lead groove 12c.
Even if 4 moves in the optical axis direction, the meshing relationship between the pinion 30 and the inclined inner gear 12d is maintained. A gear train 31 receiving the rotation of the pinion 30 is supported between the gear support plates 26 and 27, and a rotation transmission shaft 32 extending forward is integrally fixed to the shaft of the final gear 31a. I have. The rotation transmission shaft 32 has a non-circular uniform cross section.

On the other hand, a rotation guide shaft 17 fixed to the rear end face of the linear movement guide member 16
The take-out pinion 33, which is freely movable relative to the shaft 2 in the axial direction and rotates integrally, is supported in a state where the movement in the axial direction is restricted. That is, the takeout pinion 33 always moves together with the straight guide plate 17 (and the second advance / retreat cylinder 15) in the optical axis direction. The take-out pinion 33 is connected to the second advance / retreat cylinder 15.
Is meshed with the circumferential inner gear 15e formed on the inner surface of the inner gear. Accordingly, the rotation of the rotary cylinder 12 is performed regardless of the position of the first advance / retreat cylinder 14 in the optical axis direction.
d, pinion 30, gear train 31, rotation transmission shaft 3
2. It is transmitted to the second advance / retreat cylinder 15 via the take-out pinion 33 and the circumferential inner gear 15e.

The zoom lens barrel having the above-described structure is
As described above, when the rotary barrel 12 is driven to rotate in the forward and reverse directions, the first advance / retreat barrel 14 moves straight in the optical axis direction, and the second advance / retreat barrel 15 rotates. When the second advance / retreat cylinder 15 rotates, it moves in the optical axis direction, and the front group lens L1 and the rear group lens L2 move straight while changing the air gap, and zooming is performed. Thus, the front lens group L1 and the rear lens group L2 are
7 can be moved from the storage state of FIG. 7 to the tele end position of FIG. 8, and in the storage state, the first advance / retreat barrel 14 and the second advance / retreat barrel 15 are moved from the outer casing of the main body (camera body 10) and the lens cover barrel 41. Since it does not project, the storage length is extremely shortened.

Next, a molding die for molding the rotary cylinder (cylindrical molded body) 12, which is a feature of the present invention, and a method of manufacturing the same will be described with reference to FIGS. The rotary cylinder 12 shown in FIG. 9 is manufactured using a molding die 35 shown in FIG.
This molding die 35 is an upper die 4 for molding the outer surface of the rotary cylinder 12.
0 and a lower mold 41 for molding the inner surface. The lower die 41 is provided with an inclined inner gear (internal gear) 12 of the rotary cylinder 12.
d, a first cylindrical mold portion 36 having a spiral tooth shape portion 36a corresponding to the spiral groove portion 36a, and a spiral flat surface portion 37 corresponding to the clearance groove 12e.
a and a second cylindrical mold portion 37 having a. This second
The cylindrical mold portion 37 further has a spiral convex portion 37b corresponding to the lead groove 12c.

The first cylindrical mold portion 36 has a small-diameter cylindrical portion 36b having a smaller diameter than the second cylindrical mold portion 37, and a small-diameter cylindrical portion 36.
It has a spiral large diameter portion 36c formed in a spiral with a diameter larger than b. The tooth-shaped portion 36a is formed on the outer peripheral edge of the spiral large-diameter portion 36c. The second cylindrical portion 37 has a fitting hole 37c at the center thereof, and the first cylindrical portion 36 is slidably fitted in the fitting hole 37c. The second cylindrical mold portion 37 has an engagement groove portion 37d between the convex portions 37b of the flat portion 37a. The engagement groove 37
d is spirally formed in the same winding direction as the spiral large diameter portion 36c. The second cylindrical mold portion 37 is
When rotating in the direction of arrow A in FIG. 10 with the helical large diameter portion 36c engaged with d, the helical large diameter portion 36c (the toothed portion 36a) is gradually disengaged from the engagement groove portion 37d and inclined. The toothed portion 36a meshing with the inner gear 12d is
It is left inside and detached from the rotary cylinder 12. Although not shown, the upper mold 40 is configured to be divided into, for example, two split molds at appropriate portions for taking out the completed rotary cylinder 12.

Using the molding die 35 having the above structure, the rotary cylinder 12
The steps in the case of manufacturing are described. First, the upper mold 40, the first cylindrical mold part 36, and the second cylindrical mold part 37 are combined in a predetermined state, and a space for injecting a synthetic resin material (resin material) to form the rotary cylinder 12 is formed. Constitute. In this state, a synthetic resin material is injected into the space, and after the synthetic resin material is cured, the second cylindrical mold portion 37 is rotated in the direction of arrow A in FIG. 10 to gradually separate from the upper mold 40 (FIG. 11
~ FIG. 12). At this time, the second cylindrical mold portion 37 rotates to separate the small-diameter cylindrical portion 36b from the fitting hole 37c while rotating,
The toothed portion 36a that meshes with the inclined inner gear 12d is separated from the rotating cylinder 12 while being left inside the rotating cylinder 12.

Thereafter, as shown in FIG. 13, the first cylindrical mold portion 36 is moved in a direction away from the upper mold 40, and the tooth mold portion 36a is separated from the inclined inner gear 12d, so that the upper surface of the escape groove 12e is removed. Position. From this state, the first cylindrical mold portion 36 is rotated in the same direction as the second cylindrical mold portion 37. Then, the spiral large-diameter portion 36c having the tooth-shaped portion 36a
Is separated from the inside of the rotary cylinder 12 along the spiral of the escape groove 12e. Thereby, the completed rotary cylinder 1 is placed in the upper mold 40.
2 remains, but the rotary cylinder 12 can be taken out by appropriately dividing the upper mold 40.

[0028]

As described above, according to the present invention, it is possible to provide a cylindrical molded body that does not have the internal gear on the entire inner periphery and can form other cam grooves and the like. In addition, since the cylindrical molded body has a clearance groove, the clearance groove can be effectively used when the forming die is separated from the internal gear at the time of forming the internal gear.

Further, according to the mold for forming a cylindrical molded body according to the present invention, an upper mold for forming the outer surface of the cylindrical molded body and a lower mold for forming the inner surface are provided. Since it is provided with a first cylindrical mold part having a corresponding spiral tooth part and a second cylindrical mold part having a spiral flat part corresponding to the clearance groove, it is inclined with respect to the circumferential direction. The formed spiral internal gear and a cylindrical molded body having a clearance groove adjacent to the internal gear can be easily formed.

Further, according to the present invention, according to the molding die for a cylindrical molded body having a spiral lead groove parallel to the internal gear, the upper mold forming the outer surface of the cylindrical molded body and the lower mold forming the inner surface. A first cylindrical mold portion having a spiral tooth mold portion corresponding to the internal gear, and a second cylindrical mold portion having a spiral flat surface portion corresponding to the clearance groove. A helical internal gear that is inclined with respect to the circumferential direction, since the second cylindrical mold portion has a helical convex portion corresponding to the lead groove.
A cylindrical molded body having a clearance groove adjacent to the internal gear and a spiral lead groove parallel to the internal gear can be easily formed.

Further, according to the method for manufacturing a cylindrical molded body according to the present invention, the first cylindrical shape having a spiral tooth mold portion corresponding to the internal gear, which is the upper die forming the outer surface of the cylindrical molded body. Mold part,
A first step of combining a second cylindrical mold portion having a spiral flat surface corresponding to the clearance groove and a lower mold forming the inner surface of the cylindrical molded body; a resin material in a space formed by the upper mold and the lower mold A second step of injecting; a third step of rotating the second cylindrical mold part and separating from the upper mold when the resin material in the space is cured; moving the first cylindrical mold part in the axial direction A fourth step of detaching the tooth mold portion from the internal gear and positioning it in the clearance groove; and a fifth step of rotating the first cylindrical mold portion and detaching from the upper mold, so that the It is possible to easily form a cylindrical molded body having a spiral internal gear inclined and a clearance groove adjacent to the internal gear.

[Brief description of the drawings]

FIG. 1 is a schematic exploded perspective view showing an embodiment of a zoom lens barrel.

FIG. 2 is an enlarged perspective view of a rear portion of the zoom lens barrel.

FIG. 3 is an enlarged perspective view of an intermediate portion of the zoom lens barrel.

FIG. 4 is an enlarged perspective view of a front portion of the zoom lens barrel.

FIG. 5 is a perspective view showing a support mechanism of a power transmission system of the zoom lens barrel.

FIG. 6 is a perspective view showing the relationship of only the gears of the power transmission system.

FIG. 7 is a longitudinally upper half view of a state where the zoom lens barrel is housed.

FIG. 8 is a longitudinally upper half view of the zoom lens barrel in the longest extended state.

FIG. 9 is a perspective view showing a rotary cylinder which is a cylindrical molded body according to the present invention.

FIG. 10 is a perspective view showing a manufacturing process when the same cylindrical molded body is molded by a molding die.

FIG. 11 is a perspective view showing a manufacturing process when the same cylindrical molded body is molded by a molding die.

FIG. 12 is a perspective view showing a manufacturing process when the same cylindrical molded body is molded by a molding die.

FIG. 13 is a perspective view showing a manufacturing process when the same cylindrical molded body is molded by a molding die.

FIG. 14 is a perspective view showing a manufacturing process when the same cylindrical molded body is molded by a molding die.

FIG. 15 is a perspective view showing a manufacturing process when the same cylindrical molded body is molded by a molding die.

[Explanation of symbols]

 Reference Signs List 12 rotating cylinder (cylindrical molded body) 12c lead groove 12d inclined inner gear (internal gear) 12e relief groove 35 molding die 40 upper die 36 first cylindrical die part 36a tooth type part 36b small diameter cylindrical part 36c spiral large diameter part 37 Second cylindrical mold part 37a Flat part 37b Convex part 37c Fitting hole 37d Engaging groove

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02B 7/02 G02B 7/04 G02B 7/10

Claims (5)

(57) [Claims] 1. A helical internal gear inclined with respect to a circumferential direction on an inner peripheral surface of a cylindrical molded body of a resin material; a helical adjoining the internal gear and having a width wider than the tooth width of the internal gear. And a cylindrical relief body. 2. A molding die for molding the cylindrical molded product according to claim 1, comprising an upper die forming an outer surface of the cylindrical molded product, and a lower die forming an inner surface of the cylindrical molded product. The mold is provided with: a first cylindrical mold part having a spiral tooth mold part corresponding to the internal gear; and a second cylindrical mold part having a spiral flat part corresponding to the clearance groove. Mold for a cylindrical molded body. 3. The cylindrical molded product according to claim 1, wherein a spiral lead groove parallel to the internal gear is further formed on the inner peripheral surface. 4. A molding die for molding the cylindrical molded product according to claim 3, comprising an upper die forming an outer surface of the cylindrical molded product, and a lower die forming an inner surface of the cylindrical molded product. The mold includes: a first cylindrical mold portion having a spiral tooth shape portion corresponding to the internal gear; a second cylindrical mold portion having a spiral flat surface portion corresponding to the clearance groove; A helical projection corresponding to the lead groove of the portion. 5. The method for manufacturing a cylindrical molded body according to claim 1, wherein the first die having a spiral tooth mold portion corresponding to the internal gear, which is an upper mold forming an outer surface of the cylindrical molded body. A first step of combining a cylindrical mold part, a second cylindrical mold part having a helical flat surface corresponding to the clearance groove, and a lower mold forming the inner surface of the cylindrical molded body; A second step of injecting the resin material into the space defined by the above; a third step of rotating the second cylindrical mold part to separate from the upper mold when the resin material in the space is hardened; Moving the mold portion in the axial direction to separate the tooth mold portion from the internal gear and position the tooth mold portion in the clearance groove;
And a fifth step of rotating the first cylindrical mold portion to separate from the upper mold.
A method for producing a cylindrical molded body, comprising: