JPS5915056B2 - Manufacturing method of hinge device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a synthetic resin hinge with elasticity (automatic opening/closing function) by integral injection molding.

5. Many of the conventional hinges were thought of simply as a fulcrum for opening and closing.

When these hinges are actually used as parts of a product, metal springs and the like are often prepared separately and incorporated into the product depending on the purpose. In addition, the number of hinges manufactured from synthetic resin materials that are similar to metal hinges is decreasing as the strength of synthetic resin materials increases, but the number of parts is still the same as that of conventional metal products, so the cost is low. There was a desire to develop a hinge that would reduce the number of man-hours required. 15 Therefore, recently, as shown in FIG. 1, a hinge formed into a cylinder with a slit has been used.

However, in this case, although it is manufactured at a low cost, the elasticity of the cylindrical part does not work efficiently, which limits its uses.
Ivy. In view of this, the inventors have invented a method of integrally molding and manufacturing a synthetic resin hinge that automatically opens or closes the hinge, which is proposed here.

25, the method of the present invention will be explained below based on example diagrams.

In FIG. 2, reference numeral 1 denotes the outer frame of the hinge device manufactured by the method of the present invention, and has an opening 3 in the center through which the inner frame 2 formed as a protrusion of the actuating part can pass through. have

The inner frame 2 is integral with the outer frame 1 via a hinge 4 which is constantly subjected to bending stress. The contact end 5 at one end of the inner frame 2 contacts the opening front edge 6 that functions as a stopper of the opening 3,
35 is set so as not to easily pass through the opening 3, thereby forming the hinge device T. This hinge device T is manufactured by integrally injection molding an elastic synthetic resin material using an upper mold 8 and a lower mold 9. The upper mold 8 includes the upper surface portion V of the outer frame 1, the opening portion 3, and the upper surface portion 2 of the inner frame 2.
The lower die 9 defines the lower surface 1// of the outer frame 1 and the lower surface 27/ of the inner frame 2 to form an L-shaped continuous molding space. Here, the inner frame 2 is set to have an included angle α of 900 mm or slightly smaller than this with respect to the outer frame 1 of the base in consideration of demoldability and elasticity of the hinge 4. The hinge 4 is made slightly thinner than other parts, has a convex lower surface and a concave upper surface, and is in a stress-free state when die-cut. From this state, when the inner frame 2 is rotated about the hinge in the direction of the opening 3 (clockwise in FIG. 4), the back surface 5' of the abutting end 5 at the tip of the inner frame 2 will move in front of the opening. It comes into contact with the bottom tip 6/ of the edge 6. When further force is applied to push up the inner frame 2, due to the elasticity of the inner frame 2 itself and the elasticity of the hinge 4 (particularly the elasticity obtained structurally),
The contact end 5 is pushed back slightly toward the hinge 4 and pushed out onto the upper surface of the outer frame 1. This is the mode shown in FIG. 2. At this time, the hinge 4 is bent by approximately 90 degrees, and sufficient bending stress is applied. The abutting end 5 abuts against the front edge 6 of the opening, which is a stopper, and does not rotate toward the lower surface of the outer frame 1. This hinge 4 always springs the inner frame 2 against the outer frame 1 by the elastic force generated by bending stress, and even if the inner frame 2 is in an open state, it will automatically close when no external force is applied. . Next, the embodiment shown in FIG. 3 will be described. Reference numeral 10 denotes an outer frame, which has an opening 3 on the outside of the hinge 4.

An inner frame 11 serving as an operating part is divided into two parts, with the hinge 4 as a boundary, a supporting part 12 formed as a projecting piece and an opening/closing part 13. The support portion 12 of the inner frame 11 normally comes into contact with the opening front edge 6 of the opening portion 3 to regulate the maximum open position of the opening/closing portion 13. The hinge device 14 shown by this embodiment is
This is the opposite of the hinge device 7 explained in the figures, and it automatically operates in the opening direction. The hinge device 14 is manufactured by the same method as in the above-mentioned embodiment, but the shape of the mold is slightly different due to the difference in the operating direction, so it will be explained based on FIG. do. The upper mold 15 defines the outer frame 10 , its opening 3 , the opening/closing part 13 , the upper surface of the support section 12 , and the upper surface of the hinge 4 , and the lower mold 16 defines the lower surface of the outer frame 10 and the upper surface of the support section 12 . A lower surface portion and a lower surface portion of the hinge 4 are defined.

Further, it is desirable that the opening/closing part 13 of the inner hood 11 be shaped perpendicularly to the outer frame 10 serving as a base. This is because injection molding is performed using two molds, an upper mold 15 and a lower mold 16, so that mold cutting of the product is taken into consideration. Support part 1
2 may be arbitrarily set according to the required maximum opening degree β, but in consideration of the bending stress applied to the hinge 4, it is desirable to set it to an acute angle of 900 or close to 90 degrees. When integral injection molding is performed using this mold, a hinge device 14 having the shape shown in FIG. 3 is manufactured. In the die-cut state, the hinge 4 is still in a stress-free state, and when the opening/closing part 13 is rotated by applying force in the closing direction (clockwise in FIG. 5), the contact end 12/ of the tip of the support part 12 The back surface abuts the lower end of the opening front edge 6 of the opening 3, but the support part 12
Since the support part 12 is set only slightly longer than the support part 12
Due to the elasticity and the above-mentioned hinge structure, it passes through to the upper surface side of the outer frame 10 and comes into contact with the front edge 6 of the opening, which is a stopper there.
This position is the aforementioned maximum opening degree. With this configuration, the hinge device 14 has the function of closing when an external force is applied to the opening/closing portion 13, and automatically opening to the above position due to the elastic force of the hinge 4 when the external force is no longer applied. In an example in which polypropylene is used as the material for this hinge device, sufficient durability can be guaranteed without any functional deterioration even after repeated opening and closing tests tens of thousands of times.

As described above, the hinge device manufactured by the method of the present invention can reliably perform a specific operation by integrally injection molding the structure by making good use of a synthetic resin material having elasticity. The manufacturing process is simple, so we can provide products at low prices.

In addition, the strength, size, shape, etc. can be freely set according to the purpose, and the range of applications is wide. In the explanation of the hinge 4, the lower surface side is convex and the upper surface side is concave, but this case is intended to have a large degree of curvature during normal use due to the structure, and the reverse is also possible. It has a similar effect,
For example, it may be formed into an S-shape, so this shape is not particularly limited.

[Brief explanation of drawings]

Fig. 1 is a side view of a conventional product, Fig. 2 is a vertical sectional view showing an embodiment of a hinge device configured to automatically close, and Fig. 3 shows an embodiment of a hinge device configured to automatically open. 4 is a sectional view showing a method of manufacturing the hinge device of FIG. 2, and FIG. 5 is a sectional view of a method of manufacturing the hinge device of FIG. 3. DESCRIPTION OF SYMBOLS 1, 10... Outer frame, 2, 11... Inner frame, 3... Opening, 4... Hinge, 5... Contact end, 6... Opening front edge, 7, 14 ...Hinge device, 8, 15... Upper mold, 9, 16... Lower mold, 12... Support part, 13...
Opening/closing part.

Claims (1)

[Claims] 1 An opening having an arbitrary punched shape is formed inside the outer frame, and a curved hinge is formed at a part of the inner peripheral edge of this opening, and the tip of the inner frame integrally extended from this hinge is formed. When manufacturing a synthetic resin hinge device configured to engage with the inner circumferential edge of the opening on the opposite side of the hinge by the elastic action of the hinge, the shapes of the upper mold and the lower mold for molding this hinge device are as described above. 90 with respect to the longitudinal direction of the molding space that forms the opening and outer frame of the hinge device and this molding space.
It consists of a hinge with an acute angle of 90° or close to 90° and a continuous molding space that forms an inner frame connected to the hinge.Furthermore, the continuous molding space in the lower mold is filled with synthetic resin to form a mold with an opening. A spare product for the hinge device is obtained by integrally injection molding the outer frame, hinge, and inner frame, and then in this spare product, the inner frame is brought close to the outer frame while being bent at the hinge, and the tip of the inner frame forms an opening in the outer frame. A method for producing a hinge device in which the tip side of the inner frame is moved to the back side of the outer frame by further forcibly bending the hinge device when it comes into contact with the inner peripheral edge of the frame.