JPS61175027A - Apparatus for bending resin molded item - Google Patents

Abstract

PURPOSE:To improve the bent quality of a resin case main body and to reduce the number of the processing stages, by taking a resin main body case having a thick-wall section and a thin-wall section out from a mold at a temperature higher than the usual removal temperature, and pushing and bending part of the resin main body case about the thick-wall section so that an inclined shape may be formed. CONSTITUTION:A resin main body case 1 is mounted to a holder 14, and when a lever 18 of a toggle mechanism 17 is lowered, a receiving table 15 fixed to an attaching plate 16 if lowered, and the resin main body case 1 is pinched firmly between the receiving table 15 and a urethane rubber section 14a of the holder 14. Then when a handle 21 is pushed down, a pin 23 is swung upward about a pin 2 via an arm 24. By this movement, a pushing plate 26 is lifted via an arm 25, and as a result a urethane rubber 26a pushes a corner 15a of the receiving table 15 as a fulcrum. This change in the angle is given by a rotational movement of the arm 25 having the pushing plate 26 about the arm 25.

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.

Conventional technology FIG. 5(a) is a back view of a resin body case used in a general glasses-type hearing aid, FIG. 5(b) is a top view of the same case,
FIG. 5(C) is a front view of the same case, and FIG. 6 is a top view of the same case bent 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. 6, two separate molds are required: one for extracting in the A direction and one for extracting in the B direction. Therefore, the mold structure is extremely complicated.

Therefore, the resin body case is molded into the shape shown in FIG. 5, and injection molding is performed, but in order to make this molded product into the finished product shape shown in FIG. 6, it is necessary to perform bending. 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, 5 is a pedestal for the resin body case 1, 6 is a holding block, and has a concave shape of the resin body case;
It is designed to be able to move up and down via a guide bin 13 embedded in it. 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, the presser block 6 is moved downward (
Apply pressure in the direction of arrow 10) to hold and fix the resin body case 1 so that it does not move.

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
By applying pressure 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 50.

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 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 bending.

(4) Since the bending process is performed by moving the push plate 9 of the bending device in the direction of the arrow 11, the resin body case 1 and the push plate 9 do not come into uniform contact, so the contact surface of the resin body case 1 is easily damaged. .

There were other problems.

The present invention is a method for eliminating the problems of the above conventional example,
In addition to improving the bending quality of the resin body case,
The purpose is to reduce the number of processing steps.

Means for Solving the Problems In order to solve the above problems, the bending device for resin molded products of the present invention includes a resin main body case having a thick wall portion and a thin wall portion.
After injection during mold molding, it is taken out of the mold at a temperature higher than the normal take-out temperature, and a part of the resin body case is pressed and bent so that it has an inclined shape around this thick part. .

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

EXAMPLE Below, the configuration of an example of the present invention will be explained 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 main body case 1, which is fixed to the holder 20. Reference numeral 15 indicates a support plate, which is fixed to a mounting plate 16, and reference numeral 16 indicates a guide pin 19 embedded in the pace 20.
can move up and down guided by. 17 is a toggle mechanism, and by pushing down the lever 18, the mounting plate 1 is
6 are arranged to descend in conjunction with each other. 24 is pin 2
It is an arm that swings around 2, and swings when the handle 21 is pushed down. Next, the arm 25 swings around the pin 23 embedded in the arm 24.

The push plate 26 is attached to the arm 25.

FIG. 2 shows a partial sectional view of FIG. 1, with the resin main body case 1 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 sectional view of FIG. 1, and shows that the resin body case 1 is
Fig. 4 shows the state in which it is fixed, 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 Figure 5, and the molding conditions are set at a mold temperature 20 to 30 degrees Celsius higher than normal molding. . 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, cooling progresses and the resin body case 1
The thin parts 2 and 3 of the thick part 4 are in a hardened state, and the outer skin of the thick part (bent part) 4 is still hardening, but the inside of the thick part 4 has accumulated heat and is , the 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 portion 2.3 is 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, as shown in FIG.
Attach to. 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 state where it is sandwiched between the urethane rubber part 14a of No. 4 and the pedestal 15. Next, by pushing down the handle 21 in FIG.
It swings upwards with 2 as the center. Do this exercise with arm 2
5, the push plate 26 rises, and the urethane rubber 26a shown in FIG. 4 pushes up the bent portion 4 of the resin body case 1.
The bending process is performed using the corner 1.5a of the pedestal 15 as a fulcrum. 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 folded 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 rotates about the pin 23. By doing so, a uniform bending force can be applied to the folded portion 4 of the resin main body case 1. next,
After the resin main body case 1 is bent by the above operation, the finished product shape shown in FIG. 6 can be obtained by holding the resin main body case 1 in that state for a required period of time and cooling it. Next, by opening the handle shown in FIG. 1 and pushing up the lever 18 of the toggle mechanism 17, the pedestal 15 is opened upward, and then the resin body case 1 is taken out to complete the work.

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 those caused by predetermined 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, since the push plate for bending performs rocking motion, the bending portion 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 provides a resin body case having a thick wall portion and a thin wall portion after injection during mold molding.
Removed from the mold at a temperature higher than the normal removal temperature,
Since a part of the resin body case is pressed and bent so as to have an inclined shape around this thick part, the thin part of the resin body case hardens during injection molding, and only the thin part has plasticity. This process is performed to give the bending shape an inclined shape, which has the effect of improving the bending quality and reducing the number of processing steps.

[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. 5(a) is a general Figure 5 (b) is a top view of the resin main body case used for spectacle hearing aids, Figure 5 (C) is a front view of the case, and Figure 6 is a view of the case to make it easier to use. FIG. 7 is a top view of a conventional bending apparatus for resin molded products. 1... Resin main body case, 2... Surrounding thin wall part, 4...
・Bending part, 14... Holder, 15... Receiver is stand, 16... Mounting stand, 17... Toggle mechanism, 18...
・Lever, 19... Kite bin, 20... Base,
21... Handle, 22... Bottle, 23... Pin, 24... Arm, 25... Arm, 26... Push plate. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure t<

Claims (1)

[Claims] A resin body case that has a thick wall part and a thin wall part and is taken out from the mold at a temperature higher than the normal take-out temperature after injection during mold molding, and a holding means for holding a portion; and a pushing arm that presses a portion of the resin main body case that is not held by the holding means by operating an arm, and rotates around the thick part so that the resin main case has an inclined shape. A bending device for resin molded products, comprising a plate.