JPH0552256B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a bending device for resin molded products used when forming inclined shapes during injection molding of resin molded parts.

Prior Art Fig. 5a is a back view of a resin body case used in a general glasses-type hearing aid, Fig. 5b is a top view of the case, Fig. 5c is a front view of the same case, and Fig. 6 is the same case. FIG. 3 is a top view of the case folded to make it easier to use.

Conventionally, when attempting to injection mold the resin main body case 1 in a folded state as shown in FIG.
Since two separate molds are required, one for extracting in the direction B and the other for extracting in the B direction, the structure of the die is extremely complicated.

Therefore, a mold is made for the resin body case in the shape shown in Figure 5, and injection molding is performed, but in order to make this molded product into the finished product shape shown in Figure 6, it is necessary to perform bending processing. . FIG. 7 shows an apparatus used in the bending method considered in the prior art. The configuration of this device will be explained below with reference to FIG. 7. In FIG. 7, numeral 5 is a pedestal for the resin body case 1, and 6 is a holding block, which has a concave shape of the resin body casing. It is designed to be able to move up and down. 7 and 8 are hot air generators, and 9 is a push plate that can move in the direction of arrow 11.

Next, the operation of the bending device and the bending method will be explained. 5 to 7, first, after positioning and placing the resin body case 1 on the pedestal 5, pressurize the holding block 6 downward (arrow 10) to hold the resin body case 1 so that it does not move. Fix it.
Next, the vicinity of the bent portion 4 of the resin body case 1 is heated to a temperature higher than the heat deformation temperature by the hot air generators 7 and 8 to soften it, and then pressurized while moving the push plate 9 in the direction of the arrow 11. , the resin body case 1 is bent along the corner 12 of the pedestal 5.
By continuing to hold the push plate 9 in this state and cooling it, the bent portion 4 of the resin main body case 1 is hardened, and the processing is completed.

Problems to be Solved by the Invention However, in the above method, (1) The bent portion 4 of the resin main body case 1 is thick and requires heating time to raise the temperature to the heat deformation temperature up to the center.

(2) When heating with hot air, the temperature is unstable and it is difficult to obtain uniform bending accuracy.

(3) The outer skin of the bent portion 4 of the resin main body case 1 and the peripheral thin-walled portions 2 and 3 become hotter than necessary, and are likely to be distorted or damaged during the bending process.

(4) In order to perform bending by moving the push plate 9 of the bending device in the direction of arrow 11, the resin body case 1
Since the push plate 9 and the push plate 9 do not make uniform contact, the contact surface of the resin main body case 1 is easily damaged.

There were problems such as.

The present invention is a method for eliminating the problems of the conventional example, and aims to improve the quality of bending of a resin main body case and reduce the number of processing steps.

Means for Solving the Problems In order to achieve the above object, the present invention provides a holder for mounting a resin molded product in which only the thick part has plasticity and the thin part has hardened due to residual heat during injection molding, and A pedestal for holding the thin part of the molded product together with the holder, a push plate for pressing the outer skin of the thick part of the resin molded product, and a means for rotating the push plate, and after being removed from the molding die. The thick portion of the resin molded product is bent.

Effects According to the above configuration, the present invention performs processing to give an inclined shape at a time when the thin wall part of the resin body case hardens during injection molding and only the thick wall part has plasticity, thereby improving the bending quality. The number of processing steps will be reduced.

Embodiment The configuration of an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a perspective view of a bending device for resin molded products according to an embodiment of the present invention. In FIG. 1, 14 is a holder for the resin body case 1;
It is fixed to the base of 20. Reference numeral 15 denotes a pedestal, which is fixed to a mounting plate 16. 16 is guided by a guide pin 19 embedded in the base 20 and can move up and down. 17 is a toggle mechanism, and when a lever 18 is pushed down, the mounting plate 16 is lowered in conjunction with the lever 18. 24
is an arm that swings around the pin 22,
It swings by pushing down the handle 21. Next, the arm 25 swings around the pin 23 embedded in the arm 24. And push plate 2
6 is attached to the arm 25.

FIG. 2 shows a partial sectional view of FIG. 1,
The resin body case 1 is set in the holder 14. Here, a portion 14a of the holder 14 into which the resin body case 1 is set is made of urethane rubber. Further, the contact surface 26a of the resin main body case 1 of the push plate 26 is similarly lined with urethane rubber, so that it can easily fit into the resin main body case 1. FIG. 3 is a partial cross-sectional view of FIG. 1, showing the state in which the resin body case 1 is fixed by the pedestal 15, and FIG. 4 shows the state in which it is being bent.

Next, the method of the above embodiment and the operation of the bending device will be explained.

In FIGS. 1 to 4, the resin material used for the resin main body case 1 of the spectacle hearing aid is a cellulose resin, has thermoplasticity, and is injected at about 230°C. Using this material, the resin body case 1 is injection molded into the shape shown in Fig. 5.The mold temperature is 20℃ to 30℃ higher than normal molding conditions.
Molding is performed by setting the temperature to a high value. The resin body case 1 thus molded is taken out from the mold, set in the bending device shown in FIG. 1, and the bending process is started after 50 to 60 seconds. During this time, the cooling progresses and the thin parts 2 and 3 of the resin body case 1 are in a hardened state, and the outer skin of the thick part (bent part) 4 is also hardening. Heat is stored inside and a softened state is maintained. Therefore, the bent portion 4 of the resin main body case 1 is in a bendable state, and the thin walled portions 2 and 3 are in a state that is difficult to deform. A bending process is performed in the state of the resin main body case 1 described above.

Next, the operation of the bending apparatus shown in FIGS. 1 to 4 and the bending method will be explained.

First, the resin main body case 1 is attached to the holder 14 in FIG. A partial sectional view at this time is as shown in FIG. Next, by lowering the lever 18 of the toggle mechanism 17, the pedestal 15 fixed to the mounting plate 16 is lowered, and as shown in FIG. It is fixed in a sandwiched state with the pedestal 15. Next, by pushing down the handle 21 in FIG. 1, the pin 23 swings upward about the pin 22 via the arm 24. The push plate 26 moves up via the arm 25 to support this movement, and the urethane rubber 26a shown in FIG. go. During this bending process, the surface of the urethane rubber 26a of the push plate 26 changes in angle following the change in the angle of the contact surface of the bent portion 4 of the resin body case 1. This angle change is provided by the arm 25 to which the push plate 26 is attached rotating about the pin 23. By doing so, a uniform bending force can be applied to the bent portion 4 of the resin main body case 1. Next, after bending the resin main body case 1 by the above-described operation, the finished product shape shown in FIG. 6 can be obtained by keeping the resin body case 1 in that state for a required period of time and cooling it. Next, open the handle shown in FIG.
After the pedestal 15 is opened upward by pushing up, the resin body case 1 is taken out and the work is completed.

According to this embodiment, (a) residual heat from injection molding is used as the heat necessary for bending the resin main body case, so there is no need for reheating.

(b) Since the heat dissipation and cooling of the resin main case starts from the outer skin, the thick outer skin and thin wall parts can be processed in a hard state during bending, so that distortions and scratches other than the specified bending are less likely to occur.

(c) Using residual heat from injection molding provides a more stable temperature than applying heat from outside.

(d) In the bending device, the push plate for bending performs oscillating motion, so that the bending part can be pressurized uniformly without distortion.

(e) Since urethane rubber is used on the contact surfaces of the holder and push plate with the resin body case, scratches are less likely to occur during bending.

There are advantages such as

Effects of the Invention As is clear from the above embodiments, the present invention takes out a resin body case having a thick part and a thin part from the mold at a temperature higher than the normal takeout temperature after injection during mold molding. Since a part of the resin body case is pressed and bent to create an inclined shape around this thick part, the thin part of the resin body case hardens during injection molding, and only the thick part has plasticity. Since the bending process is performed to give the bending shape an inclined shape, the bending quality is improved and the number of processing steps is reduced.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a bending device for resin molded products according to an embodiment of the present invention, FIGS. 2 to 4 are sectional views showing the bending process of the same embodiment, and FIG. Figure 5b is a top view of the resin body case used for hearing aids, Figure 5c is a front view of the case, Figure 6 is a top view of the case folded to make it easier to use. FIG. 7 is a top view of a conventional bending device for resin molded products. 1...Resin main body case, 2...Peripheral thin wall part, 4
...Bending portion, 14... Holder, 15... Rest, 16... Mounting base, 17... Toggle mechanism, 1
8...Lever, 19...Guide pin, 20...Base, 21...Handle, 22...Pin, 23...
...Pin, 24...Arm, 25...Arm, 26
...Push board.

Claims (1)

[Claims] 1. A holder for mounting a resin molded product in which only the thick part becomes plastic and the thin part is hardened due to residual heat during injection molding, a holder for holding the thin part of the resin molded product together with the holder, and the resin molded product. A press plate for pressing the outer skin of the thick part of the resin molded product and a means for rotating the press plate are provided, and the thick part of the resin molded product which has become plastic due to the residual heat during injection molding after being taken out from the molding die. A bending device for resin molded products that performs bending processing.