JPS6289921A - Helicoid member for lens - Google Patents

Abstract

PURPOSE:To eliminate helicoid play even if a helicoid screw has such shape that the helicoid play may occur because the precision after formation of the helocoid screw is low, by forming a part of the helicoid screw into a spring which has the spring effect utilizing flexural elasticity. CONSTITUTION:Since the helicoid screw 12 is provided on the outside peripheral surface of a helicoid cylinder part 11 formed integrally with a synthetic resin and the elasticity (spring function) in the radial direction is given to the helocoid screw 12, the structure of the helicoid screw 12 continuously provided on the outside peripheral surface of the helicoid cylinder part 11 at a conventional constitution is not used but the screw 12 is divided into three to provide interrupted helicoid screws 12. Clearance grooves 14 are provided on the outside peripheral surface of the helicoid cylinder part 11 to give the elasticity (spring function) in the radial direction at the open end parts 12a of individual helicoid springs 12, and an elastic part (spring part) 13 is formed at each end part 12a of helicoid screws 12.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a helicoid member for a lens of an optical device, and more particularly to a helicoid member for a lens that can prevent rattling of a helicoid screw in a helicoid member integrally molded from a synthetic resin material. .

[Prior art]

For the purpose of eliminating defects in the thread stacking of helicoids integrally molded from synthetic resin materials, the helicoid members shown in Figures 1 to 4 were disclosed in Japanese Patent Application Laid-open No. 56-9710 (Japanese Patent Application No. 1983-1983).
No. 85174), a helicoid member for a lens in an optical device was proposed.

Thus, the helicoid member shown in the first figure has a helicoid screw 2 screwed on the outer periphery of a helicoid cylinder portion 1, and a part a in which the bits and teeth of the helicoid screw 2 are slightly changed, and is made of plastic material. It is constructed by integrally molding.

In the case of such a helicoid member, in the engagement between the members screwed into the helicoid screw 2, even if there is a dimensional error during the molding process of the helicoid screw 2 or play due to wear occurs, the above-mentioned part of the slight The different portions a can absorb looseness.

The helicoid member shown in FIG. 2 has a helicoid screw 2 screwed around the outer periphery of a helicoid cylinder portion 1, and a part of the helicoid screw 2 has a slightly different leet angle, and is integrally molded from a plastic material. It is constructed by

In the case of this helicoid member, it is intended to prevent the occurrence of backlash by absorbing it through portions with slightly different lead angles.

The helicoid member shown in FIG. 3 is the same in that the helicoid screw 2 is screwed into the helicoid cylinder portion 1, but a portion C of the helicoid screw 2 has a different thread shape from the others ( The screw thread is wider than the width of the screw thread), and the part C is intended to absorb play and prevent play from occurring.

Furthermore, FIG. 4 is a partially enlarged view of the helicoid screw provided in the helicoid member.
The groove 3 gives elasticity to the screw thread in the direction of the arrow, thereby preventing rattling due to the reaction force when the screw is pressed in the thrust direction. .

[Problem that the invention seeks to solve]

However, each configuration of the helicoid member described above has the following drawbacks.

(1) Even if the pitch, lead angle, or thread shape is partially changed, the screw of the member that is screwed into the helicoid screw will not have the above-mentioned pinch, lead angle, or thread shape change part of the helicoid screw. Since the helicoid screw also engages and slides, if the helicoid screw wears out, the interface between the pitch, lead angle, or thread shape will also wear out, so it is necessary to prevent backlash due to helicoid wear. I can't.

(2) Providing parts with different shapes etc. in a part of the helicoid screw means that the entire effective part of the threaded thread will not slide evenly from the viewpoint of threading and sliding operation, so the pitch, lead angle, thread Screw threads in parts with different thread shapes wear out faster.

Therefore, it becomes difficult to maintain the initial setting value for the rotational torque of the helicoid.

(3) Regarding the absorption of changes in the mechanical strength due to temperature changes by the backlash absorbing part, since the normal screw part also deforms and the threaded part of the backlash absorbing part deforms as well, in practice, the above mentioned absorption Setting the thread shape of the part is quite difficult due to the setting of the rotational torque of the helicoid.

Furthermore, it is extremely difficult to set the shape and dimensions of the screw of the backlash absorbing portion and the regular screw portion of 1Ffi, taking into account the amount of deformation of the mold.

(4) Each of the above-mentioned backlash absorbing parts, which includes a structure in which grooves are provided in the threads of the helicoid and elasticity is imparted to the threads, has a smaller meshing clearance than other parts.
The rotational torque of the helicoid becomes heavier.

Therefore, if the engagement length of the helicoid that is screwed into the backlash absorbing portion changes as the helicoid is extended or inserted, the rotational torque of the helicoid cannot be kept constant, and uneven rotation cannot be avoided.

(5) In the case of a structure in which a helicoid thread is provided with a groove to give it elasticity, the shape of a helicoid screw is usually about 11 mm in height and 7 mm in width of the thread. If a groove is provided and the bending elasticity of the screw thread is used, the size selection range is too small, and the spring constant cannot be freely set.

Therefore, when the forebank is designed to optimize the rotational torque of the helicoid, it is very difficult to determine the shape of the groove.

Therefore, it is an object of the present invention to provide a helicoid member for a lens that can effectively obtain the desired functions and effects without the above-mentioned drawbacks.

[Means and effects for solving the problem] In a helicoid member for a lens having a helicoid screw integrally formed in a helicoid cylinder portion, at least a part of the helicoid screw has a screw effective diameter larger than the screw effective diameter of the engaging member. By providing a threaded portion having a threaded portion and forming a gap between the threaded portion and the helicoid cylinder portion, elasticity in the radial direction is imparted to the threaded portion.

〔Example〕

Examples of the helicoid member for a lens according to the present invention will be described in detail below with reference to the drawings.

5 to 7 show a first embodiment of the present invention, in which a helicoid screw 12 is screwed on the outer periphery of a helicoid cylinder portion 11 integrally molded from synthetic resin, and elasticity in the radial direction is applied to the helicoid screw 12. In order to provide a spring action, instead of the usual structure in which screws are continuously provided on the outer periphery of the helicoid cylinder part 11, three screws are installed as shown in Fig. 5.6.
The divided and intermittent helicoid 12 is screwed.

The open end portion L2a of each helicoid screw 12 is formed by providing a groove 14 on the outer peripheral surface of the helicoid cylinder portion 11.
Each end 12 of the helicoid screw 12 is configured to be able to impart elasticity (spring action) in the radial direction.
An elastic part (spring part) 13 is formed on the part a.

Further, each elastic portion 13 is provided with a slit 15 so that uniform elasticity can be exhibited.

Further, regarding the shape of the screw thread of each elastic portion 13, examples of the shape shown in FIG. 7 can be cited, and in the case of FIG.
7C shows that the screw grooves 13a between each screw thread are formed to become gradually shallower as they reach the open end 12a, and FIG. An example will be shown in which the height is gradually increased as the height increases.

8 to 10 show a second embodiment of the present invention, in which the screw threads 13b connected to each other in each elastic portion 13 in the first embodiment are configured to be independent from each other. This is an example of the case.

That is, by providing a slot 21 between each thread 16 of each elastic portion 13, each thread 16 is made independent.

However, the embodiment in which the threads 16 are made independent from each other can of course be implemented with a structure in which a plurality of threads (for example, a structure in which every two or three pitches are separated from each other) are separated.

Further, as shown in FIGS. 10a and 10b, each thread 16 of each elastic portion 13 is curved outward at its open end 16a, or the height of each thread 16 is adjusted so that the open end 16a
It is possible to form the helicoid screw 12 by gradually increasing the height until the helicoid screw 12 reaches , and to cause interference when it engages with a member that engages with the elastic portion 13 of the helicoid screw 12, for example, a so-called inner helical helical.

Figures 11 and 12 show a third embodiment of the present invention, in which each helicoid screw 12 is divided into three parts on the outer periphery of the helicoid cylinder part 11 and is screwed intermittently to form an elastic part. Each open end 19 of each helicoid screw 12, which has an effective screw diameter larger than the effective screw diameter of the engaging member that meshes with the helicoid screw 12, is used as a fulcrum, and the threaded portion between the open ends 19 is provided with radial elasticity (spring). It is constructed by imparting a function).

That is, by providing a gap 17 (gap) that is longer than the helicoid thread portion between both open ends 19 of each helicoid screw 12 along each thread direction, both open ends of each helicoid screw 12 are An elastic part with part 19 as a fulcrum (
It is possible to configure arrow a) in Fig. 11.

In the figure, 18 indicates a side groove.

FIG. 13 shows a fourth embodiment of the present invention. In this embodiment, the effective diameter of the screw is larger than the effective diameter of the meshing member that meshes with each helicoid screw 12 in the elastic portion A of the third embodiment. Compared to a configuration in which the threads 30 of each helicoid screw 12 are connected to each other, there is a slot free 2 between each thread 30.
By providing 0, it is shown that they are configured independently from each other.

Note that the embodiments shown in Figures 11 to 13 are based on the case where both open ends 19 of each helicoid screw 12 are used as fulcrums.
It is also possible to use either one as a fulcrum and the other end to be in a free state similar to the above-mentioned Embodiment 1.2. It is also possible to implement the configuration with the radially raised thread as shown.

Furthermore, although the third and fourth embodiments above show examples in which the helicoid screw is divided into three parts, the helicoid screw screwed on the outer periphery of the helicoid cylinder portion 11 has the same effective screw diameter of the engaging member that engages with this helicoid screw. In addition to multi-dividing or irregularly dividing the helicoid screw with the same effective diameter, it is also possible to partially divide the helicoid screw with the same effective diameter screwed continuously on the outer periphery of the helicoid cylinder portion 11. By configuring each elastic part in the threaded part, which has a thread effective diameter larger than the thread effective diameter of the engaging member that meshes with the helicoidal thread described above, and which has a negated part (gap), or not only a part but a plurality of elastic parts. This can be implemented by configuring an elastic part on the threaded part at an arbitrary location.

Therefore, when a member (engaging member) that is screwed into the helicoid screw 12 of the helicoid member having the above-mentioned configurations, for example, a so-called inner helical member, meshes and slides thereon, the thread of the inner helical member is connected to the elastic portion 13 of the helicoid screw 12, It interferes with A and pushes it down, causing elastic deformation of bending in the radial direction.

Therefore, when the two are in meshing and sliding contact, the elastic portions 13 and 1 continue to press each other due to action and reaction forces, so that play in the hemlock screw 12 can be prevented.

As is clear from the above description, according to the present invention, the following actions and effects can be obtained.

(1) By making a part of the helicoid screw a screw that has a spring effect using bending elasticity, even if the helicoid screw has a low precision after molding and has a screw shape that causes helicoid backlash, the parts that mesh with it ( Since the meshing member) can be pressed, helicoid play can be eliminated.

(2) The threaded part with the spring effect can be integrally molded with the helicoid cylinder member, and the gap formed between the threaded part and the helicoid cylinder part is opened in the direction of removal of the molding die, so the molding cost is reduced. remains the same and mass production is possible.

(3) Even if the helicoid screw precision after molding is low, helicoid backlash after assembly can be eliminated by only the molding process, that is, the lapping process is not necessary, so the number of assembly steps can be reduced.

C4) Except for a part of the helicoid screw, it is possible to give the screw a spring effect over the entire circumference, so that rattling of the screw can be evenly prevented.

(5) Since it is possible to give the helicoid screw a continuous spring effect in the forward and backward movement direction of the helicoid, a constant pressing force can be applied regardless of the helicoid being fed out and put in, thereby eliminating uneven rotation of the helicoid. does not produce

(6) Even if the helicoid screw wears and the play of the screw increases, the screw part, which already has a spring effect, develops a pressing action due to the reaction force of bending, so fluctuations in the helicoid's rotational torque can be suppressed to a small level. can. Even if the helicoid screw wears out, the rattling prevention effect is maintained.

(7) When imparting elasticity to a helicoidal screw, it is possible not only to make the adjacent threads act as a unit, but also to make each adjoining thread act as a spring acting independently, so there is a degree of freedom in selecting the spring constant. In many cases, it is possible to easily deal with optimization of the rotational torque of the helicoid.

(8) In addition to the normal shape, the thread shape of the bulge part that has a spring effect in a helicoid screw has a shape in which the height of the thread or the depth of the thread root is not constant, and it interferes with the screw that is meshed and fitted. It is also possible to change the rotational torque of the meshing member appropriately.

(9) With regard to changes in the helicoidal thread pitch due to temperature changes, there is no change in the helicoid thread pitch from that at room temperature, and the threaded portion having the spring effect of the present invention prevents rattling of the thread.

[Brief explanation of drawings]

1 to 4 are plan views and partially enlarged perspective views showing the helicoid tube portion of a conventional helicoid member, FIGS. 5 to 13 show embodiments of the present invention, and FIGS. 5.6 show the first embodiment. A plan view of a helicoid member showing an example, a partially longitudinal side view, and Fig. 7a-
c is an enlarged plan view of the elastic part, Figs. 8 and 9 are plan views and partially longitudinal side views showing the second embodiment, Fig. 10 is an enlarged plan view of the elastic part, and Figs. 11 and 12 are the third embodiment. FIG. 13 is a plan view and a partially longitudinal sectional side view showing an example, and FIG. 13 is a partially longitudinal sectional view showing a fourth embodiment. 11... Helicoid cylinder portion 12... Helicoid screw 12a... Open end portion 13... Elastic portion 13a... Screw groove 13b... Screw thread 14... Nige groove 15... Slit 16...・Thread thread 16a...Open end 17...Negated part 18...Side groove 19...Open end (fulcrum) 20...Suriwari 21...Suriwari. 19 Figure 2 g3 Figure! ! Figure 4 Figure 6 Figure 5 Error 7F! ! J Figure 9 Figure 8 l110!

Claims (1)

[Claims] (1) In a helicoid member for a lens having a helicoid screw integrally molded in a helicoid cylinder portion, at least a portion of the helicoid screw is provided with a threaded portion having an effective screw diameter larger than the effective screw diameter of the engaging member, and the threaded portion and 1. A helicoid member for a lens, characterized in that a gap is formed between the helicoid cylinder part and the threaded part has elasticity in a radial direction.