JPS5912885B2 - How to pivot parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for pivotally connecting members such as links and levers, and provides a method for pivotally connecting two members in a simple and rotatable manner. .

Generally, when connecting links, levers, etc., a stepped screw 1 is used as shown in Figure 1, and the threaded portion 1a of this screw 1 is inserted into a through hole formed in one member 2 such as the link or lever. 3 and into a screw hole 5 formed in the other member 4 such as a link or lever, so that the one member 2 is pivotally connected to the other member 4 so as to be rotatable. However, this type of device requires a separate stepped screw 1, requires a considerable amount of effort to install, and has the disadvantages of loosening the fastened state of the screw 10 due to vibration or other factors. was caused. Therefore, recently, as shown in FIG. 2, one member 6 and the other member 7
are stacked on top of each other, and synthetic resin material is poured into the through holes 8 and 9 formed in these members 6 and T to form 115 pivot shafts 10 by molding, and both members 6 and □ are mutually pivoted. An attempt was made to wear it. However, in all of this type of devices that have been tried so far, the through holes 8 and 9 formed in the members 6 and 7 are
is cylindrical, and therefore, due to the molding shrinkage that occurs during the molding process of the pivot 10, a tensile force as shown by the arrow in FIG. 2 acts on the pivot 10, and the member 6, □ does not rotate smoothly. I had a problem with it becoming like this. The present invention eliminates the above-mentioned conventional drawbacks, and the shape of the through hole formed in the member is a truncated cone shape, and the molding shrinkage that occurs during the molding process of the pivot is used inversely to form the shaft and the member. Rather, the two members are pivotally connected so that they can rotate relative to each other so that a gap is formed between them.

An embodiment of the present invention will be described below with reference to FIGS. 3 and 430.

In the figure, 11 and 12 are members such as links and levers that are pivotally connected to each other, and 13 and 14 are cylindrical parts 1 formed on the members 11 and 12.
3a, 14a and truncated conical portions 13b, 14b;
Reference numeral 15 denotes a pivot shaft formed directly and integrally by pouring a molding material made of synthetic resin into the through holes 13 and 14 and molding the same. Note that the through holes 13 formed between the members 11 and 12
, 14 are stacked on top of each other such that the large diameter portions of the truncated conical portions 13b and 14b are located on the outside.

Therefore, the pivot 15 formed by molding is shaped like a drum. In the above embodiment, the shrinkage rate during molding of the pivot shaft 15 is S, and the cylindrical portion 1 of the through holes 13 and 14 is
If the diameter of 3a, 14a is D, the outer periphery of the columnar portion of the pivot 15 after molding and the columnar portions 13a, 14a of the above-mentioned through holes 13, 14.
A gap t1 expressed by the following equation is formed between .

- On the other hand, as shown in FIG. 4, if the center of the molding shrinkage that occurs during molding of the pivot shaft 15 is O, it will be located at any point A or b of the truncated cone portion 14b of the through hole 14 formed in the member 12 during molding. After molding, the molding material that had been
It will move along the line connecting the above points A and b to C and d, respectively.

This amount of transfer is expressed by the following equation. Now, draw a perpendicular line from the molding shrinkage center 0 on the extension of the line connecting points A and b, and make the intersection point e, and draw a perpendicular line from the molding shrinkage center 0 on the extension of the line connecting points C and d. Assuming that the intersection point is f, the gap T2 formed between the outer periphery of the pivot shaft 15 after molding and the truncated conical portion 14b of the through hole 14 is a distance E,
It becomes f.

Therefore, if the intersection of the horizontal line t and the line segments E and b is set to g, and the angle of inclination between the horizontal line t and the line segment "71" is set to α, the gap T2 becomes as follows.

Then, if the intersections of the horizontal line t and the cylindrical portion 14a of the through hole 14 and the outer periphery of the cylindrical portion of the pivot shaft 15 after molding are I and h, respectively, then the line segment i is .b, and the gap T2 is expressed by the following equation.

In this way, according to the above embodiment, a gap is formed between the through holes 13, 14 formed in the members 11, 12 due to contraction during molding and the pivot shaft 15 after molding, and the members 11, 12 are They are pivotally connected to each other so that they can rotate smoothly.

As is clear from the above embodiments, the present invention involves forming a truncated cone-shaped through hole in each of the two members to be pivotally connected, and integrally molding a pivot into the through hole by molding. A suitable gap is formed between the two due to shrinkage during molding, and the above 2.
Two members are rotatable around a pivot, and two
If the two members are formed with a pivot shaft, the two members will have a structure that can be rotated as is, and will also rotate smoothly, making the pivoting work extremely easy and extremely advantageous in practice.

[Brief explanation of the drawing]

1 and 2 are sectional side views of a conventional pivoting device, FIG. 3 is a sectional side view of an embodiment according to the method of the present invention, and FIG. 4 is an explanatory view of the same pivot molding. 11, 12... Member, 13, 14... Through hole, 13b
, 14b... truncated cone portion, 15... pivot.

Claims (1)

[Claims] 1. Form a truncated cone-shaped through hole in each of the two members to be pivotally connected, overlap the above-mentioned through holes with the large diameter side of each truncated cone shape located on the outside, and then A pivot is directly integrally molded by a molding process by pouring a synthetic resin material into the hole, a gap is formed between the pivot and the hole by contraction during the molding process, and the two members are rotated using the pivot as a fulcrum. A method for pivoting members, which is characterized by allowing the members to pivot freely.