JP2998529B2 - Resin molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molding apparatus for producing a resin molded article having an undercut portion, a positioning rib and the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG.
b is formed, and the attachment portion Wb is an undercut portion Wc for preventing resin sink. Further, a rib Wd for positioning on a mating member main body (not shown) is protrudingly provided on the back surface of the flat surface portion Wa of the resin molded body W.

[0003] Such a resin molding W is usually molded by a resin molding apparatus shown in Fig. 10 equipped with a slide die for removing the undercut portion Wc from the die. FIG.
0 indicates a state where the resin molding apparatus 100 is opened. As shown in FIG.
And a movable mold 120 having a cavity and a slide mold 130 together with the fixed mold 110, and an extrusion mechanism 1 for releasing the resin molded body W formed on the movable mold 120 from the mold.
40.

Here, the configuration of the slide mold 130 will be described with reference to FIGS. FIG. 11 is a plan view of the slide mold 130, and FIG.
13 is a cross-sectional view along the line BB of FIG. 11, and FIG. 14 is a cross-sectional view showing a state where the slide mold 130 has moved. As shown in these figures, the slide die 130 has an undercut shaping portion 132 at its end.
have. The slide mold 130 has a slide recess 133 (FIG. 11) formed therein, and the movable protrusion 122 of the movable mold 120 is slidably fitted in the slide recess 133. The rib forming recess 122a is formed on the forming surface 131a of the movable mold projection 122.

Returning to FIG. 10, the extruding mechanism 140 is an extruding device for releasing a product, and also a mechanism for moving the slide mold 130 and the like. This pushing mechanism 140
A first extruded plate 141 and a second extruded plate 142 fitted to the first extruded plate 141 are provided. The first and second push plates 141 and 142 are movably attached to the movable mold 120 by being pressed by a rod 150 of an advance / retreat drive mechanism (not shown). An extruding pin 143 is fixed to the first extruding plate 141.
The first and second extruding plates 141 and 142 are movable
When it moves to the side, it penetrates through the extrusion pin through hole 121b and projects from the molding surface 121a. Further, a return pin 144 is fixed to the first push plate 141. The return pin 144 is configured to be able to pass through the return pin through hole 121c of the movable die 120.

Next, a molding process performed by the resin molding apparatus 100 will be described. First, the fixed mold 110
Then, the movable mold 120 is clamped and injection molded into the cavity C to form the resin molded body W. Then, the movable mold 1
20 is opened with respect to the fixed mold 110, and the rod 150 of the advance / retreat drive mechanism pushes the first and second extrusion plates 141 and 142 toward the movable mold 120, and the resin molding W is pushed by the extrusion pin 143. To the molding surface 12 of the movable mold 120.
1a, the undercut shaping portion 132 of the slide mold 130 is moved to the undercut portion Wc of the resin molded body W.
From the undercut portion Wc. At this time, the rib Wd is simultaneously pulled out from the rib forming recess 122a of the movable mold 120 as shown in FIG.

After the resin molding W is removed, the rod 150 of the advance / retreat driving mechanism is retracted and the mold is clamped in order to proceed to the next molding step. At the same time as the mold closing is completed, the first and second extrusion plates 141 and 142 are retracted to the original positions. Thereby, one cycle of a series of resin molding steps is completed.

[0008]

However, in the above-mentioned conventional resin molding apparatus 100, in order to form the rib Wd, a slide-type recess 133 is formed in the slide-type mold 130, and the movable-type recess 133 is formed in the slide-type recess 133. 120 movable protrusions 12
2 is slidably fitted. For this reason, the planar connection portion of the slide mold 130 is reduced, and sharp corners are formed, and the strength at the corners is reduced. Moreover, the slide type 130
Although heat treatment such as nitriding treatment is added to increase the strength, there is a problem that the heat deformation of the slide mold 130 is easily caused during this heat treatment.

Further, since the slide recesses 133 of the slide mold 130 slide relative to each other with respect to the movable projection 122 of the movable mold 120, a high surface accuracy is required for the sliding surfaces, resulting in an increase in cost. There was also.

An object of the present invention is to solve the problems of the prior art described above, and is an apparatus for manufacturing a resin molded article having an undercut portion and a rib by a slide mold.
It is an object of the present invention to provide a resin molding apparatus capable of increasing the strength of a slide mold and facilitating a sliding surface between a movable mold and a slide mold.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a resin molded article having an undercut portion projecting from an end of a resin body and a rib projecting from an inner surface of the resin body. In a resin molding apparatus to be manufactured, a fixed mold and a movable mold each having a molding surface are slidably fitted to the movable mold, and an undercut portion is formed together with the molding surfaces of the fixed mold and the movable mold. A sliding die having a surface, a driving means for moving the slide die in a predetermined direction with respect to the movable die so as to retreat from an undercut portion of the resin molded resin body, A through hole formed in the same direction as the predetermined direction of the slide die, and a rod-shaped member slidably fitted in the through hole and fixed to the movable die, A mold member having a groove forming recess, and wherein the through hole has a distance between an end of the through hole on the undercut portion side and the rib forming recess, for retreating from the undercut portion. It is characterized in that it is formed to be larger than the movement amount of the slide type.

[0012]

The resin molding apparatus according to the present invention produces a resin molded body having an undercut portion and a rib.
In this apparatus, a resin is injected into a cavity formed by the molding surfaces of the fixed mold and the movable mold and the molding surface of the slide mold, and a resin molded body having an undercut portion is molded. In addition, a through hole is formed in the slide type,
A mold member is slidably fitted in the through hole.
A rib forming recess is formed on the tip end surface of the mold member. The rib is formed on the inner surface of the resin molded body by the rib forming recess.

[0013] After the resin molding is molded, the slide die is moved in a predetermined direction by the driving of the driving means so as to retreat from the undercut portion. At this time, since the mold member is fixed to the movable mold, a space is formed in the portion of the slide-type through hole. Since the through hole is formed such that the distance between the end on the undercut portion side and the rib forming recess is larger than the moving distance of the slide die, the rib formed by the rib forming recess is the rib forming recess. After moving out of the space, move in the space. Therefore, the rib does not hinder the slide type movement.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to further clarify the structure and operation of the present invention described above, preferred embodiments of the present invention will be described below.

FIGS. 1 to 3 show a resin molding apparatus 10 according to an embodiment of the present invention. FIG. 1 shows a state in which the resin molding apparatus 10 is clamped, FIG. 2 shows a state in which the mold is opened, and FIG. Indicates a state of sliding. As shown in these drawings, the resin molding apparatus 10 is an apparatus for manufacturing a resin molded body W having an undercut portion Wc (see FIG. 9), and includes a fixed mold section 20, a movable mold section 30, Slide type part 4
0, a pushing mechanism 50, and an advance / retreat driving mechanism (not shown) are the main components. With the configuration of the resin molding apparatus 10, the movable mold portion 30 is clamped to the fixed mold portion 20, and is injected into the cavity C to form a resin molded body W. Further, the movable mold portion 30 is opened. After that, the resin molded body W is taken out by the slide mold part 40 and the forward / backward drive mechanism.

Hereinafter, the configuration and operation of each part of the resin molding apparatus 10 will be described. The fixed mold part 20 includes a fixed mold 23 fixed to a fixed mold mounting plate 21, and a molding surface 23 a forming a part of the cavity C is formed on the fixed mold 23. The movable mold part 30 includes a movable mold 33 fixed to a movable mold mounting plate (not shown) and having a molding surface 33a, and the mounting plate 34 is fastened and fixed by a bolt 36 via a leg 35. I have.

Further, a slide mold part 40 is assembled to the movable mold part 30. FIG.
It is a top view which shows the core type | mold 41 of FIG. As shown in the cross-sectional view of FIG. 5 along the line CC in FIG. 4, the movable mold 33 is formed with a fitting recess 33b and a sliding hole 33c, and the sliding recess 33b is formed in the fitting recess 33b. The core die 41 of the part 40 is fitted, and the movable rod 42 fixed to the core die 41 is slidably fitted in the sliding hole 33c. The core die 41 is slidably moved in the direction of the angle θ by the movement of the movable rod 42, so that the undercut shaping portion 41 formed at the end thereof is formed.
b is slid in the direction of arrow a.

As shown in FIG. 6, which is a cross-sectional view taken along the line DD of FIG. 4, the core mold 41 has an inclined hole 41e. The inclined hole 41e is connected to an extrusion pin through hole 33d formed in the movable die 33, and its angle θ is set in the same direction as the sliding hole 33c, that is, the core die 41.
Is the same as the moving direction. A fixed rod 43 is slidably fitted in the inclined hole 41e. That is, the base end 43a of the fixed rod 43 is screwed and fixed to the screw sleeve 43d at the lower end of the movable die 33. On the other hand, the other end of the fixed rod 43 is a forming surface 43b, and a rib forming recess 43c is formed in the forming surface 43b. The rib forming recess 43c is a recess that forms the rib Wd of the resin molded body W. Therefore, when the core mold 41 is pushed up by the movable rod 42, the fixed rod 43 is fixed to the movable mold 33 via the screw sleeve 43d. Are recessed with respect to the flat portion 41a. In addition,
The inclined holes 41 e and the fixed rods 43 are provided by the number of the ribs Wd formed on the resin molded body W.

Here, in determining the diameter of the inclined hole 41e, the position of the rib forming recess 43c and the sliding amount of the core mold 41 in the direction of the arrow a are considered. That is, as shown in FIG. 8, the distance between the end of the fixed rod 43 on the side of the undercut shaping portion 41b and the rib forming recess 43c is L.
Assuming that L1 is 1, and the amount of movement of the core mold 41 in the direction of arrow a is L2, L1> L2. In addition, a water passage 46 through which cooling water flows is formed near the undercut shaping portion 41b of the core mold 41.

Next, a process of manufacturing the resin molded body W having the undercut portion Wc and the rib Wd using the resin molding apparatus 10 will be described. As shown in FIG.
0 is moved to the fixed mold part 20 side, and the mold is clamped to form the cavity C. At this time, the core mold 4 of the slide mold part 40
1 is stored in the fitting recess 33b. In this closed state, the resin is injected into the cavity C via a nozzle of an injection molding machine (not shown), and the resin molded body W is molded.
The resin molded body W has an undercut portion Wc and a rib Wd.
(See FIG. 6) is formed.

After the resin molded body W is cooled and solidified,
The movable mold part 30 moves to the position of FIG. 2 and opens the mold.
Subsequently, the advance / retreat drive rod 61 of the advance / retreat drive mechanism advances to the movable mold part 30 side, and pushes the first and second extruding plates 51 and 52 of the extrusion mechanism 50 toward the movable mold 33 side. Release of W is performed (state of FIG. 3). That is, when the first and second extruding plates 51 and 52 move, the movable rod 42 attached to the first extruding plate 51 via the slide mechanism 44 is pushed while sliding in the direction of arrow b, so that the core mold 41 is pressed. Moves in the direction of arrow c. At this time,
Since the fixed rod 43 slides with respect to the inclined hole 41e, it guides the movement of the core mold 41. Thereby, the resin molding W is moved in the direction of arrow d by the extrusion pins 53 attached to the first extrusion plate 51, and the core mold 41 is slid in the direction of arrow a to form the undercut shaping portion 41b. The body W exits from the undercut portion Wc (the state of FIG. 8).

At this time, as shown in FIG. 7, the rib Wd of the resin molding W formed by the rib forming recess 43c of the fixed rod 43 comes off from the rib forming recess 43c, and further, the movement of the core mold 41 is performed. And the upper part of the inclined hole 41e formed together with it. Then, as shown in FIG. 8, when the undercut shaping portion 41b comes off from the undercut portion Wc, the rib Wd has not yet hit the inclined hole side wall 41f. It does not hinder. Thereby, the resin molding W is released from the core mold 41.

Then, when the movable die 33 moves in the closing direction after the forward / backward drive rod 61 of the forward / backward drive mechanism is retracted, the movable die 33 pushes the return pin 73, and the first and second push plates 51 and 52 are moved. , Until it comes into contact with the mounting plate 34. Thereby, the core mold 41 and the push pin 53 return to the original positions shown in FIG. The resin molding W is molded by repeating the operation of the resin molding device 10.

Therefore, according to the above embodiment, when the resin molded body W is released from the mold, the undercut portion Wc comes off due to the sliding operation of the undercut shaping portion 41b of the core die 41. At this time, the rib Wd
It moves relatively in the inclined hole 41e and does not interfere with the core mold 41. Therefore, the core mold 41 can release the resin molded body W without breaking the rib Wd.

Further, since the inclined hole 41e is formed in the core mold 41 and the rib forming recess 43c is formed at the tip of the fixed rod 43 fitted in the inclined hole 41e, the core mold 41 is formed.
Can have a constant cross-sectional shape. Therefore, as described in the related art, the core mold 41 does not have to have a deformed shape as described in the related art in order to form the rib Wd, so that the mold has high strength and durability. Excellent and excellent in manufacturability.

According to the resin molding apparatus 10, the inclined hole 4
Since 1e may be formed in the same direction as the mounting recess 41d of the core mold 41, it can be easily formed with high accuracy. Since the fixed rod 43 fitted into the inclined hole 41e formed with high precision as described above also serves as a guide when the core mold 41 moves, the core mold 41 can be smoothly moved in the angle θ direction.

Also, since the inclined hole 41e is formed in the core mold 41 and the rib forming recess 43c is formed at the tip of the fixed rod 43 fitted in the inclined hole 41e,
Can have a constant cross-sectional shape. Therefore, in the core mold 41 having a constant cross-sectional shape, the water passage 46 can be formed near the undercut shaping portion 41b as shown in the figure, and the cooling effect of the water passing through the water passage 46 allows the water passage 46 to be formed. It is possible to prevent sink marks easily formed in the cut portion Wc.

[0028]

As described above, according to the resin molding apparatus of the present invention, a through hole is formed in a slide die, and a mold member having a rib forming recess is slidably fitted in the through hole. Since the ribs of the resin molded body are formed by pressing, it is not necessary to make the outer wall of the slide mold uneven, and the strength of the slide mold is large. Further, in order to form the ribs, the outer wall of the slide mold is formed into an uneven shape, and the sliding surface with the movable mold does not need to be formed on the outer wall, so that the sliding surface of the movable mold and the slide mold can be easily formed. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a clamped state of a resin molding apparatus according to one embodiment of the present invention.

FIG. 2 is a sectional view showing a mold opening state of the resin molding apparatus.

FIG. 3 is a cross-sectional view showing a state where the slide mold is moved from the state of FIG. 2;

FIG. 4 is a plan view showing a core type.

FIG. 5 is a sectional view taken along the line CC of FIG. 4;

FIG. 6 is a sectional view taken along line DD of FIG. 4;

FIG. 7 is a sectional view showing a state where the core mold has moved from the state of FIG. 6;

FIG. 8 is a sectional view showing a state in which the core mold has further moved from the state of FIG. 7;

FIG. 9 is a perspective view showing a resin molded body.

FIG. 10 is a sectional view showing a state in which the mold of the conventional resin molding apparatus is opened.

FIG. 11 is a plan view showing a conventional core type.

FIG. 12 is a sectional view taken along the line AA of FIG. 11;

FIG. 13 is a sectional view taken along the line BB of FIG. 11;

FIG. 14 is a sectional view showing a state in which the core mold has moved from the state of FIG. 13;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Resin molding apparatus 20 ... Fixed mold part 21 ... Mold frame 23 ... Fixed mold 23a ... Molding surface 30 ... Movable mold part 33 ... Movable mold 33a ... Molding surface 33b ... Fitting recess 33c ... Sliding hole 33d ... Extrusion pin Through-hole 34 ... Mounting plate 35 ... Leg 36 ... Bolt 40 ... Slide type part 41 ... Core type 41a ... Flat part 41b ... Undercut shaping part 41d ... Mounting recess 41e ... Slope hole 41f ... Slope hole side wall 42 ... Movable Rod 43: fixed rod 43a: base end 43b: molding surface 43c: rib forming recess 43d: screw sleeve 44: slide mechanism 46: water passage 50: extrusion mechanism 51, 52: first and second extrusion plates 53: extrusion Pin 61: Forward / backward drive rod

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B29C 45/26-45/44 B29C 33/44

Claims (1)

(57) [Claims] 1. A resin molding apparatus for producing a resin molded body having an undercut portion protruding from an end of a resin main body and a rib protruding from an inner surface of the resin main body, wherein a fixed mold and a movable mold each having a molding surface. A sliding mold which is slidably fitted to the movable mold and has a molding surface for shaping an undercut portion together with the molding surfaces of the fixed mold and the movable mold; and an undercut of the resin molded article Driving means for moving the slide die in a predetermined direction with respect to the movable die so as to retreat from the portion; and a through-hole formed in the slide die and formed through the slide die in the same direction as the predetermined direction. A rod-shaped member slidably fitted in the through-hole and fixed to the movable die, and having a rib-forming recess on a tip end surface thereof; A resin molding apparatus, wherein a distance between an end of the through-hole on the undercut portion side and a rib forming recess is formed to be larger than an amount of movement of a slide die for retreating from the undercut portion. .