JP2009113245A - Injection molding machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably manufacture a decorative molded product of uniform quality. <P>SOLUTION: When a lower die 30Y with a decorative film F stretched by covering the opening of a molding recessed portion 100 is driven by an air cylinder 45 to move upward to the half-tightened position, the circular cutting edge 111 of an upper die 30X presses the decorative film F onto the opening edge of the molding recessed portion 100 and keeps them in contact with each other. After molten resin P is ejected from a supply port 114, the both dies 30X, 30Y are finally tightened to mold a decorative molded product. Struck portions 70 are mounted at the corners diagonally to a lower die plate 31Y, while striking portions 73 are mounted in the predetermined high positions of vertical frames 12. At the end when the lower die 30Y moves upward to the half-tightened position, the struck portions 70 abut on the striking portions 73 from downward. The lower die 30Y thereby always stops in a constant rising position. At that time, a clearance having a predetermined dimension s slightly narrower than thickness of the decorative film F is left between the top end of the circular cutting edge 111 and the upper surface of the lower die 30Y. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an injection molding machine used for manufacturing a decorative molded product.

Conventionally, what shape | molds a decorative molded product with an injection molding machine is well-known (for example, refer patent document 1). As an example, as shown in FIG. 11, an upper die 1 and a lower die 2 that are opposed to each other vertically are provided, a molding concave portion 3 is provided on the opposing surface of the lower die 2, and the opposing surface of the upper die 1 is provided. Is formed with an annular cutting blade 5 that can be tightly fitted into the opening edge of the molding recess 3 at the outer peripheral edge of the front end surface of the molding projection 4. A resin supply port 6 is opened inside.
Then, after the decorative film F is stretched so as to cover the opening of the molding recess 3 of the lower mold 2 in the mold open state, the lower mold 2 is moved up to the half-clamping position. At this time, the molding protrusion of the upper mold 1 When the ring-shaped cutting blade 5 4 presses the decorative film F and presses it against the opening edge of the molding recess 3 of the lower mold 2, the tip of the ring-shaped cutting blade 5 is brought into close contact with the decorative film F. In this state, the molten resin is injected from the resin supply port 6 of the upper mold 1, the molten resin is injected into the space between the decorative film F and the molding protrusion 4, and then the lower mold 2 is in the final fastening position. The ring-shaped cutting blade 5 is tightly fitted into the opening edge of the molding recess 3, and the decorative film F sticks to the inner surface of the molding recess 3, while the molding recess 3 and the molding protrusion 4. The molten resin is spread and filled throughout the cavity, and the peripheral edge of the decorative film F is cut. After that, when the molten resin is solidified, a decorative molded product in which a decorative film F is stretched on one surface of the resin molded product is manufactured.

On the other hand, an injection molding machine normally requires a stroke for obtaining a corresponding mold opening amount and a holding of a clamping pressure for a driving source of a molding die. The mold clamping and mold opening of the mold are performed by driving an air cylinder, and the clamping pressure is maintained by hydraulic pressure driven by air via an air-hydraulic converter. We proposed what to do with a cylinder.
If an injection molding machine equipped with such a drive source is to be used for the production of the above-mentioned decorative molded product, an air cylinder is used for half-tightening the lower mold 2 and a hydraulic cylinder is used for subsequent final fastening. Is possible.
Japanese Patent Laid-Open No. 2002-1768

However, when the lower die 2 is moved to the half-tightened position by the air cylinder, the stop position is likely to vary. For example, when the upper die 1 is too close, the ring-shaped cutting blade 5 is decorated as shown in FIG. 12A. The decorative film F is scratched by strongly pressing the film F, and as shown in FIG. 12B, when the molten resin P is poured, the decorative film F breaks and leaks. A gap is formed between the decorative film F and the decorative film F, which also leads to the leakage of the molten resin P, which may result in a defective product.
The present invention has been completed based on the above circumstances, and an object of the present invention is to make it possible to stably produce a decorative molded product of a certain quality.

  The injection molding machine according to the present invention includes a first mold and a second mold which are arranged to face each other, wherein a molding concave portion is formed on a facing surface of the first mold, and a tip is formed on a facing surface of the second mold. The outer peripheral edge of the first mold is provided with a molding protrusion and a resin supply port that can be fitted into the opening edge of the molding recess, and the surface of the first mold opposite to the side facing the second mold A die plate disposed between the die plate and the first die, and a hydraulic cylinder capable of being driven by air as a drive source via an air-hydraulic converter, and connected to the die plate. An air cylinder that moves the first mold together with the hydraulic cylinder between a half-clamping position adjacent to the second mold and a mold opening position spaced apart from the second mold; Between the die plate of the first mold and the second mold when the mold is half-tightened A receiving frame having receiving portions facing each other that can be clamped, a receiving position where the two molds in a half-tightened state are inserted between the receiving portions, and the both molds Is provided with a drive mechanism for relatively moving between the receiving portion and the receiving release position where it is removed from between both receiving portions, and covers the opening of the molding recess of the first mold in the mold open state. After the decorative film is stretched, the first mold is moved to a half-tightened position, and the molten film is supplied from the resin supply port of the second mold in a state where the receiving frame is moved to the receiving position. After the injection between the molding projection and the molding projection, the mold is brought into a final tightening state in which the molding projection is fitted into the opening edge of the molding recess by driving the hydraulic cylinder. And the first gold is driven by the air cylinder. Stopper means is provided for stopping the first mold at a position close to the second mold by a predetermined distance when the first mold is moved to the half-tightened position. However, it has characteristics.

The decorative molded product is manufactured as follows. After the decorative film is stretched to cover the opening of the molding recess of the first mold in the mold open state, the first mold is moved to the half-clamping position by driving the air cylinder. At this time, the first mold is stopped at a position close to the second mold by a predetermined distance by the stopper means. Thereby, the front-end | tip outer periphery of the shaping | molding protrusion of a 2nd metal mold | die presses a decoration film, it presses with the moderate force with respect to the opening edge of the shaping | molding recessed part of a 1st metal mold | die, and the front-end | tip outer periphery of a shaping | molding protrusion is decorated. It will be in the state contact | adhered with respect to the film. At the same time, the receiving frame is moved to the receiving position.
In this state, the molten resin is injected from the resin supply port of the second mold, and the molten resin is injected into the space between the decorative film and the molding protrusion while the decorative film faces the inner surface of the molding recess. . Subsequently, the two molds are finally tightened by driving the hydraulic cylinder, and the molding protrusion is fitted into the opening edge of the molding recess. The molten resin is spread and filled in the entire area in the cavity formed between the two parts. When the molten resin is solidified, a decorative molded product in which a decorative film is stretched on one surface of the resin molded product is manufactured.

In the manufacturing process described above, when the first mold is moved to the half-clamping position, the stop position can vary. For example, if the first mold is too close to the second mold, the outer peripheral edge of the tip of the molding protrusion is a decorative film. Press strongly to damage the decorative film and break when molten resin is injected, causing leaks, or conversely, if the degree of proximity is low, there will be a gap between the molded protrusion and the decorative film. Similarly, there is a risk of molten resin leaking.
In contrast, in the present invention, when the first mold is moved to the half-tightened position, the stopper means is provided so that the first mold is always stopped at a position close to the second mold at a predetermined distance. Thereby, the front-end | tip outer periphery of the shaping | molding protrusion of a 2nd metal mold | die can always press a decorating film with normal force, and is the state closely_contact | adhered with respect to the decorating film, without damaging a decorating film. Retained. Therefore, it is avoided that leakage occurs during the subsequent injection of the molten resin, and the manufacture of defective products is prevented.

The following configuration may also be used.
(1) The molding protrusion of the second mold is provided with an annular cutting blade that can be tightly fitted into the opening edge of the counterpart molding recess.
When both molds are finally tightened, the decorative cutting film is cut by tightly fitting the annular cutting blade into the opening edge of the molding recess. Simultaneously with the molding of the resin molded product, so-called trimming can be performed to remove unnecessary portions of the decorative film.

(2) The second mold is disposed above the first mold in the main body frame, and the air cylinder is vertically disposed between the die plate of the first mold and a horizontal base. The second mold is supported so as to be floatable with respect to the main body frame, and the main body frame is provided with a bumped portion provided on the die plate from below. The stopper means is configured by providing an abutting portion that abuts.
When the air cylinder is extended from the mold open state and the die plate is pushed up, the first mold is raised toward the half-tightened position, and the abutted portion of the die plate is moved to the abutting portion provided on the main body frame. When hit from below, the first mold is accurately stopped at a position close to the second mold at a predetermined distance. When the hydraulic cylinder is extended after the receiving frame is moved to the receiving position, the die plate is lowered while compressing the working air and contracting the air cylinder, and is received by the receiving portion on the lower side of the receiving frame. At the same time, the second mold floats and is received by the upper receiving portion, and the first mold is further pushed up from this state, whereby both molds are finally tightened.

  (3) The said abutting part of the said die plate is provided in two places on the substantially opposite side across the center in the outer peripheral part of the same die plate. Since two locations on the opposite side across the center of the outer periphery of the die plate are abutted against the abutting portion, the die plate and thus the first mold can be stopped in its original posture without tilting. it can.

(4) A die plate is provided on the upper surface of the second mold, and positioning plates are vertically provided at both ends of the die plate protruding from the second mold, and the die plate is A surface that is placed over the upper ends of the two vertical frames while the positioning plates are applied to the outer surfaces or inner surfaces of the two opposing vertical frames of the main body frame, and the positioning plates of the vertical frames are applied to the positioning frames. A horizontal bar protrudes from the positioning plate, and a vertically long slot through which the horizontal bar is inserted is opened in the positioning plate.
The second mold is positioned and supported by the main body frame, and the horizontal bar can float while moving relatively up and down in the long hole.

  According to the injection molding machine of the present invention, it is possible to stably produce a decorative molded product of a certain quality.

<Embodiment>
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. In this embodiment, a vertical injection molding machine of an injection compression molding type is illustrated.
In FIG. 1, reference numeral 10 denotes a main body frame which is installed on a predetermined installation surface via a leg portion (not shown). The main body frame 10 has a structure in which four vertical frames 12 are erected on a horizontal base 11 so as to form a plane square. The main body frame 10 includes a pair of upper mold 30X and lower mold 30Y. Equipped. Here, the upper mold 30X corresponds to the second mold of the present invention, and the lower mold 30Y corresponds to the first mold of the present invention.

As shown in detail in FIG. 8, a molding recess 100 is formed at the center of the upper surface of the lower mold 30Y. The molding recess 100 is formed in a disk shape having a predetermined thickness, and an opening-side region on the inner peripheral surface of the molding recess 100 is an upright vertical surface 101, and a region on the bottom side following this is formed. The R surface 102 has an inner diameter that gradually decreases toward the bottom.
On the other hand, a molding protrusion 110 is formed concentrically with the molding recess 100 on the lower surface of the upper mold 30X. An annular cutting blade 111 is formed on the peripheral edge of the lower surface of the molding protrusion 110, and the outer periphery of the tip of the annular cutting blade 111 is tightly fitted into the vertical surface 101 on the inner peripheral surface of the molding recess 100. It is like that. In addition, the ceiling surface of the recessed portion 112 surrounded by the ring-shaped cutting blade 111 in the molding projection 110 is a pair on the opposite side of the center of the ceiling surface and at the hem position of the ring-shaped cutting blade 111. A dead-end vertical hole 113 is formed.

  As will be described in detail later, when the upper and lower dies 30X and 30Y are finally tightened, the tip of the annular cutting blade 111 in the molding projection 110 of the upper mold 30X is within the opening edge of the molding recess 100 of the lower mold, that is, vertically. A cavity having a predetermined shape is formed by the clearance between the molding protrusion 110 and the molding recess 100 at the time when the surface 101 is closely fitted into the surface 101. In addition, a molten resin supply port 114 is opened at the center of the ceiling surface of the recess 112 of the upper mold 30X.

  The upper mold 30X is attached to the center of the lower surface of the upper die plate 31X. The upper die plate 31X has a flat rectangular shape, and angle-shaped positioning members 32 are fixed to the four corners of the lower surface by bolts 33. In detail, each positioning member 32 is left and right on both the front and rear sides. It is provided in the direction to be back to back. The upper die plate 31X is placed on the upper end surface of the vertical frame 12 while the vertical portions 32A of the positioning members 32 that are paired on the left and right sides are sandwiched between the outer surfaces of the left and right vertical frames 12 on both the front and rear sides. After the die plate 31X is positioned in the left-right direction, the die plate 31X is placed on the vertical frame 12.

In addition, bolts 34 facing in the left-right direction are attached to the upper end portions of the vertical frames 12 so as to protrude from the inner surface to the outer surface side, while the bolts 34 protrude from the vertical portion 32A of the positioning member 32. A longitudinal slot 35 that can be inserted through the end is formed. As a result, the upper die plate 31X is also positioned in the front-rear direction, and the projecting end of the lateral bolt 34 moves up and down relatively in the elongated hole 35, and can float a little with the upper die 30X.
A resin supply head 38 is provided on the upper surface side of the upper die plate 31X, and the resin supply head 38 supplies, for example, molten resin generated by a screw type resin injection machine 39 toward the supply port 114. The molten resin is injected at a low pressure from the supply port 114 toward the molding recess 100 of the lower mold 30Y facing the supply port 114.

A mounting plate 40 projects from the upper positions of the left and right side surfaces of the upper mold 30X, and tie bars 41 are suspended from the mounting plates 40.
The lower die 30Y is attached to the upper surface side of the lower die plate 31Y with a hydraulic cylinder 50 described later interposed therebetween. The lower die plate 31Y is a planar rectangle that is slightly smaller than the upper die plate 31X. Specifically, as shown in FIG. 2, the left and right width dimensions are smaller than the left and right intervals of the vertical frame 12, and The dimension in the depth direction is set to be approximately equal to the dimension between the outer surfaces of the vertical frames 12 facing in the front-rear direction.
Insertion holes 42 are opened at the left and right ends of the lower die plate 31Y, and the tie bars 41 suspended from the upper mold 30X side are slidably inserted into the insertion holes 42.

An air cylinder 45 is provided upward at the center of the base 11 and the tip of the piston rod 46 of the air cylinder 45 is connected to the center of the lower surface of the lower die plate 31Y. A buffer member 43 made of a compression coil spring is provided at the lower end of the tie bar 41.
When the piston rod 46 of the air cylinder 45 is extended, as shown in FIG. 1, the lower die 30Y rises along the tie bar 41 in both the lower die plate 31Y and the hydraulic cylinder 50 and approaches the upper die 30X, as described later. When the piston rod 46 is contracted in a half-tight state, the lower die 30Y is lowered and separated from the upper die 30X, that is, the die is opened as shown in FIG.

  As shown in FIGS. 1 and 8, the normal rising position of the lower mold 30Y in the above-described half-tightened state is that of the ring-shaped cutting blade 111 provided on the upper surface of the lower mold 30Y and the molding protrusion 110 of the upper mold 30X. It is a position approaching the front end with an interval of a predetermined dimension s in the vertical direction, and the dimension s is slightly smaller than the thickness of the decorative film F to be applied. In addition, in each figure, the thickness of the decorating film F is described larger than actual so that an understanding of an effect | action etc. may become easy.

Now, in the present embodiment, means is provided for always stopping the lower mold 30Y at the normal raised position when half-tightened as described above.
Therefore, as shown in FIGS. 1 and 2, the abutted portions 70 are provided at the right front corner portion and the left back corner portion of the lower die plate 31 </ b> Y. The abutted portion 70 is formed in a horizontally long block shape, and at the corner on the right front side of the lower die plate 31Y, the left end side of the abutted abutting portion 70 is applied to the side surface on the near side, and two bolts 71 are provided. The right end side protrudes to the front side of the front side surface of the vertical frame 12 on the right front side. On the other hand, at the corner on the left back, the right end side of the abutted portion 70 is applied to the side surface on the back side and is similarly fixed with two bolts 71, and the left end side is the back side surface of the vertical frame 12 on the left back. It protrudes on the back side.
The two abutting portions 70 are provided in a symmetrical posture at diagonal positions across the center of the lower die plate 31Y.

On the other hand, at the predetermined height positions in the vertical frame 12 on the right front side and the vertical frame 12 on the left rear side, the abutting portions 73 that abut each of the abutted portions 70 are provided. The abutting portion 73 is formed in a vertically long block shape, and the abutting portion 73 is applied to the front-side surface of the vertical frame 12 on the right front side and is fixed by two upper and lower bolts 74. The left rear vertical frame 12 is fixed with two upper and lower bolts 74 with the abutting portion 73 applied to the inner surface.
Then, as described above, when the piston rod 46 of the air cylinder 45 is extended, the lower die 30Y rises along the tie bar 41 together with the die plate 31Y and the hydraulic cylinder 50, and approaches the upper die 30X. The outwardly projecting ends of the abutted portions 70 provided at the right front and left corners of the lower die plate 31Y abut against the lower surfaces of the corresponding abutting portions 73 provided on the vertical frame 12 and stopped. The lower mold 30Y can always be stopped at the above-mentioned regular raised position.
The extension stroke of the piston rod 46 of the air cylinder 45 is slightly larger than the distance required for the lower mold 30Y to reach the normal raised position from the mold opening position.

  Four hydraulic cylinders 50 are installed, and as shown in FIG. 3, a piston 53 formed at a substantially central portion in the longitudinal direction of the rod 52 is tightly and freely slidable in a short cylinder body 51. The ring 54 is screwed at a position slightly below the upper end of the upper rod 52X. A hydraulic connection port 56 is opened in the lower surface chamber 55 </ b> Y of the piston 53, and a return spring 57 is mounted in the upper surface chamber 55 </ b> X, and the rod 52 is always urged downward by the elasticity of the return spring 57. The ring 54 is stopped by contacting the rod cover 58X. At this time, the lower end of the lower rod 52Y projects downward from the head cover 58Y.

  The hydraulic connection port 56 of each hydraulic cylinder 50 is connected to the output side of a common air-hydraulic converter 60 (hereinafter referred to as a booster 60) by a high-pressure hose 61. The booster 60 simply converts the air pressure as a driving source into a high hydraulic pressure several times to several tens of times. In FIG. 3, when operating air is supplied to the first port P1, the ram 62 advances. When high hydraulic pressure is generated and acts on the lower surface chamber 55Y of the hydraulic cylinder 50, the rod 52 moves up with high thrust, and when operating air is supplied to the second port P2, the ram 62 moves backward to release the hydraulic pressure and return. The rod 52 is returned downward by the elasticity of the spring 57.

  Such hydraulic cylinders 50 are respectively arranged at the four corners of the upper surface of the lower die plate 31Y. Specifically, the hydraulic cylinders 50 are placed on the upper surface of the lower die plate 31Y while fitting the lower projecting ends of the lower rod 52Y into the escape holes 44. The four corners of the lower surface of 58Y are fixed with screws. On the other hand, the screw portion 59 above the ring 54 in the upper rod 52X is fixed by being screwed into a screw hole formed in the base portion 30Ya of the lower die 30Y, that is, the ring 54 fixed to each upper rod 52X is lower die. The upper protruding end of the upper rod 52X is integrally coupled to the lower mold 30Y while receiving the four corners of 30Y.

  Further, the main body frame 10 is equipped with a C frame 20 that functions to receive a reaction force of high-pressure final fastening. As shown in FIG. 4, the C frame 20 includes a pair of left and right side plates 21 having a substantially C-shaped side surface with the same distance as the distance between the hydraulic cylinders 50 in the left and right direction. It is assembled integrally by fastening with bolts 22, and as a whole, the shape is such that the rear ends of the horizontal upper and lower receiving parts 23, 24 are connected by a vertical connecting part 25. .

A pair of rails 14 extending in the front-rear direction are laid at an intermediate position between the left and right vertical frames 12 on the base 11, and left and right sliding legs 27 provided at the lower end of the C frame 20 are rails. 14, the C frame 20 is supported so as to be freely movable in the front-rear direction along the rail 14.
Here, the height position of the receiving surface 23 </ b> A of the upper receiving portion 23 in the C frame 20 is larger than the height position of the upper surface of the upper die plate 31 </ b> X before the hydraulic cylinder 50 is driven, as shown in FIG. 1. S1 (for example, 2 mm) is set higher. The height position of the receiving surface 24A of the lower receiving portion 24 in the C frame 20 is higher than the height position of the lower surface of the lower die plate 31Y when the lower mold 30Y is finally tightened as the air cylinder 45 is extended. Is set to be lower by dimension S2 (for example, 4 mm).
In other words, when the upper and lower molds 30X and 30Y are half-tightened by the air cylinder 45, there is a clearance of S1 between the upper die plate 31X and the receiving surface 23A of the upper receiving portion 23 of the C frame 20, There is a clearance of S2 between the lower die plate 31Y and the receiving surface 24A of the lower receiving portion 24 of the C frame 20.

On the other hand, an air-type rodless cylinder 65 is mounted in a posture facing the front-rear direction at a position behind the vertical air cylinder 45 on the base 11 and between the rails 14. .
The lower end portion of the connecting portion 25 of the C frame 20 is coupled to the sliding table 66 protruding from the upper surface of the rodless cylinder 65, and the C frame 20 is moved back and forth as the sliding table 66 reciprocates back and forth. 4 is the same as the receiving position R1 in which the half-tightened molds 30X and 30Y (including the die plates 31X and 31Y) are inserted between the upper and lower receiving portions 23 and 24, as shown by the solid line in FIG. As shown by the chain line in the figure, the half-tightened molds 30X and 30Y (including the die plates 31X and 31Y) are removed from the receiving release position R2 where they are removed from the upper and lower receiving portions 23 and 24. It is designed to be driven back and forth.

  In the final fastening of the upper and lower molds 30X and 30Y, the C frame 20 moves to the receiving position R1, and the half-clamped molds 30X and 30Y (including the die plates 31X and 31Y) are the upper and lower receiving parts 23 and 24. The hydraulic cylinders 50 are driven, that is, the rods 52 are moved upward in a state where the molten resin is injected into the cavity between the molds 30X and 30Y. When the rod 52 of the hydraulic cylinder 50 moves upward, the working air that is the working fluid of the air cylinder 45 is compressible on the lower side of the hydraulic cylinder 50, and therefore the working air is compressed and the piston rod 46 of the air cylinder 45 is compressed. The lower die plate 31Y is pushed down while being contracted, and is received by the receiving surface 24A of the lower receiving portion 24. On the other hand, on the upper side of the hydraulic cylinder 50, the lower die 30Y rises and the tip of the ring-shaped cutting blade 111 of the fitting projection 110 of the upper die 30X is fitted into the opening edge of the molding recess 100, that is, final tightening is performed. In this state, the molten resin in the cavity is compressed, and the upper die along with the lower die 30Y and the upper die 30X is moved while the tip of the lateral bolt 34 of the vertical frame 12 is relatively moved down in the long hole 35. The plate 31X is pushed up and received by the receiving surface 23A of the upper receiving portion 23.

In other words, when the hydraulic cylinder 50 is driven from a state in which both molds 30X and 30Y are half-tightened, the upper and lower die plates 31X and 31Y are sandwiched and received by the upper and lower receiving portions 23 and 24 of the C frame 20, The upper and lower molds 30X and 30Y are held in a high-pressure state in the final fastening state in which the tip of the ring-shaped cutting blade 111 is fitted into the opening edge of the molding recess 100 by a predetermined size.
Further, the extension stroke of the rod 52 of the hydraulic cylinder 50 is at least filled with clearances S1 and S2 between the upper and lower die plates 31X and 31Y and the upper and lower receiving surfaces 23A and 24A of the corresponding C frame 20, and It is sufficient to move the die 30 </ b> Y from a position where the annular cutting blade 111 is separated from the upper surface of the lower die 30 </ b> Y by a predetermined dimension s to a position where the tip of the annular cutting blade 111 fits within the opening edge of the molding recess 100. Distance is required.

Then, the effect | action of this embodiment is demonstrated.
Initially, the C frame 20 is retracted to the receiving release position R2 as shown by a chain line in FIG. 4, and as shown in FIG. 5, the piston rod 46 of the air cylinder 45 is contracted to be in the mold open state. The decorative film F is stretched so as to cover the opening of the molding recess 100 of the lower mold 30Y in the mold open state. Thereafter, the piston rod 46 of the air cylinder 45 is extended, and the lower die plate 31Y and the hydraulic cylinder 50 are both pushed up toward the half-tightened position, and when reaching the final stage, as shown in FIG. When the abutted portion 70 fixed to the die plate 31Y abuts against the abutting portion 73 fixed to the vertical frame 12 from below, the lower die plate 31Y and the lower die 30Y are prevented from being lifted, and the lower die 30Y is Stop at the normal ascent position. When the lower die 30Y is in the normal raised position, in other words, when it is in a normal half-tightened state, the vertical direction between the upper surface of the lower die 30Y and the ring-shaped cutting blade 111 of the molding protrusion 110 of the upper die 30X is Since the predetermined dimension s slightly smaller than the thickness of the decorative film F is taken, the tip of the ring-shaped cutting blade 111 of the forming protrusion 110 of the upper mold 30X is shown in detail in FIG. Presses the decorative film F with an appropriate force against the opening edge of the molding recess 100 of the lower mold 30Y, and the tip of the ring-shaped cutting blade 111 is in close contact with the decorative film F.

Next, the sliding table 66 of the rodless cylinder 65 is driven forward, and the C frame 20 moves to the receiving position R1 indicated by the solid line in FIG. In this state, the molten resin is injected from the supply port 114 of the upper mold 30X at a low pressure, and the decorative film F and the molded film F are molded while pressing the decorative film F toward the bottom surface of the molded recess 100 as shown in FIG. The molten resin P is injected into the space between the protrusions 110.
When a predetermined amount of molten resin P is injected and the injection is stopped, each hydraulic cylinder 50 is driven. When the rod 52 of the hydraulic cylinder 50 moves upward, the upper and lower die plates 31X and 31Y are sandwiched and received by the upper and lower receiving portions 23 and 24 of the C frame 20 as shown in FIG. 30Y is in a final tightening state in which the tip of the ring-shaped cutting blade 111 is fitted into the opening edge of the molding recess 100 by a predetermined size, and is held in this state at high pressure.

  With this final tightening operation, as shown in FIG. 10, the peripheral edge portion of the decorative film F is cut by the ring-shaped cutting blade 111, and the decorative film F sticks to the inner surface of the molded concave portion 100, and the molded concave portion 100. The molten resin P spreads and fills the entire area in the cavity formed between the molding protrusion 110 and the molding protrusion 110. When the predetermined time passes and the molten resin P is solidified, a decorative molded product in which the decorative film F is stretched on one surface of the resin molded product is molded.

Thereafter, the drive of the hydraulic cylinder 50 is released, and both molds 30X and 30Y return to the half-tightened state shown in FIG. 1, and the upper and lower die plates 31X and 31Y and the upper and lower receiving portions 23 and 24 in the C frame 20 A clearance is secured between them. From this state, when the sliding table 66 of the rodless cylinder 65 is driven rearward, the C frame 20 moves to the receiving release position R2 as shown by a chain line in FIG.
Finally, when the piston rod 46 of the air cylinder 45 contracts to the original position, the lower mold 30Y is lowered to the original position, that is, the mold is opened (see FIG. 5). The decorative molded product is temporarily held, for example, on the upper mold 30X side, and is ejected toward a predetermined extraction position by a protruding rod (not shown) provided on the upper mold 30X side.
Thereafter, the above operation is repeated.

  As described above, according to the present embodiment, when the lower die 30Y is raised to the half-tightened position, the abutted portion 70 of the lower die plate 31Y is brought into contact with the abutting portion 73 of the vertical frame 12 at the end of the ascent. The lower die 30Y is always stopped at a normal position where a predetermined dimension s is opened between the upper surface thereof and the annular cutting blade 111 of the upper die 30X. Thereby, the ring-shaped cutting blade 111 can always press the decorative film F against the opening edge of the shaping | molding recessed part 100 with normal force, and is closely_contact | adhered with respect to the decorative film F, without damaging the decorative film F. Is kept in the state. Therefore, it is avoided that leakage or the like occurs during the subsequent injection of the molten resin P, and manufacture of defective products is prevented.

When stopping the ascent of the lower die plate 31Y, two diagonal positions sandwiching the center of the outer periphery of the lower die plate 31Y are made to abut against the abutting portion 73. Therefore, the lower die plate 31Y and thus the lower die 30Y It can be stopped while maintaining the horizontal posture without tilting.
Moreover, since the unnecessary part of the decorative film F is cut, that is, trimming is performed together in the final fastening process to form the resin molded product, the manufacturing process can be simplified.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) For the ring-shaped cutting blade provided on the molding protrusion of the upper die, the final tightening process is performed in the final fastening process by taking a predetermined radial distance from the inner peripheral surface of the molding recess or by rounding the tip. Trimming for cutting unnecessary portions may not be performed, and trimming may be performed in a later process.
(2) Stopper means for locking to the lower die plate and stopping its rise is not limited to those exemplified in the above embodiment, but may have other structures such as directly contacting the outer periphery of the lower die plate. Also good.

(3) In the case of providing two locations for the stopper means, the number is not necessarily limited to the two locations on the opposite side across the center, and the number of locations itself is one or three or more.
(4) The structure for supporting the upper die plate in a floatable manner is not limited to that shown in the above embodiment. For example, while the guide pins are vertically arranged on the upper surface of the vertical frame, the guide pins are inserted into the upper die plate. Other structures may be employed, such as forming a guide hole.
(5) The present invention can also be applied to a horizontal injection molding machine in which a pair of molding dies are opposed to each other so as to be able to contact and separate in the horizontal direction.

The partially cutaway front view of the injection molding machine which concerns on one Embodiment of this invention Plan sectional view showing the arrangement of stopper means Cross section of hydraulic cylinder with booster Partially cutaway side view of injection molding machine Partially cutaway front view showing mold open Partially cutaway front view showing half-tightened state Partially cutaway front view showing the final tightening state Sectional view of the mold in the half-tightened state Cross-sectional view during injection of molten resin The same sectional view in the final tightened state Sectional view of a mold according to a conventional example Sectional view of an example of the half-tightened state Cross section of the molten resin at the time of injection

Explanation of symbols

10 ... Body frame 11 ... Base 12 ... Vertical frame 20 ... C frame (receiving frame)
23, 24 ... receiving part 30X ... upper mold (second mold)
30Y ... Lower mold (first mold)
31X ... Upper die plate 31Y ... Lower die plate 32 ... Positioning member 32A ... Vertical part (positioning plate)
34 ... Bolt (horizontal bar)
35 ... long hole 45 ... air cylinder 50 ... hydraulic cylinder 52 ... rod 60 ... booster (pneumatic-hydraulic converter)
65 ... Rodless cylinder (drive mechanism)
70: Abutted part (stopper means)
73 ... Abutting part (stopper means)
DESCRIPTION OF SYMBOLS 100 ... Molding recessed part 110 ... Molding protrusion 111 ... Ring-shaped cutting blade 114 ... Resin supply port F ... Decorating film P ... Molten resin R1 ... Receiving position R2 ... Receiving release position

Claims (5)

A first mold and a second mold disposed opposite to each other, wherein a molding recess is formed on the facing surface of the first mold, and an outer peripheral edge of a tip of the facing surface of the second mold is the molding recess. The one provided with a molding protrusion and a resin supply port that can be fitted in the opening edge,
A die plate disposed on a surface of the first mold opposite to the side facing the second mold;
A hydraulic cylinder provided between the die plate and the first mold and capable of being driven with air as a drive source via an air-hydraulic converter;
Air that is connected to the die plate and moves with the hydraulic cylinder between a half-clamping position close to the second mold and a mold opening position spaced apart from the second mold. A cylinder,
A receiving frame having receiving portions opposed to each other capable of clamping between the die plate of the first mold and the second mold in a state where the both molds are half-tightened;
The receiving frame includes a receiving position where the molds in a half-tightened state are inserted between the receiving parts, and a receiving release position where the both molds are removed from between the receiving parts. And a drive mechanism for relatively moving between,
After the decorative film was stretched to cover the opening of the molding recess of the first mold in the mold open state, the first mold was moved to the half-tightened position, and the receiving frame was moved to the receiving position. In this state, after the molten resin is injected between the decorative film and the molding projection from the resin supply port of the second mold, the molding projections are molded by the molding cylinder by driving the hydraulic cylinder. It is configured to be in a final tightened state fitted in the opening edge of the recess,
Further, when the first mold moves to the half-clamping position by driving the air cylinder, the first mold is separated from the second mold by a predetermined dimension by being locked to the die plate. An injection molding machine characterized in that stopper means for stopping at a close position is provided. 2. The injection molding machine according to claim 1, wherein the molding protrusion of the second mold is provided with an annular cutting blade that can be tightly fitted in an opening edge of the molding recess of the counterpart. 3. . In the main body frame, the second die is disposed above the first die, and the air cylinder is provided vertically between the die plate of the first die and a horizontal base. And the second mold is supported to be floatable with respect to the main body frame,
Further, the stopper means is configured by providing the main body frame with an abutting portion that abuts the abutted portion provided on the die plate from below. Item 3. The injection molding machine according to Item 2. 4. The injection molding machine according to claim 3, wherein the abutted portions of the die plate are provided at two locations on opposite sides of the center of the outer periphery of the die plate. A die plate is provided on the upper surface of the second mold, and positioning plates are vertically provided at both end portions of the die plate protruding from the second mold, and the die plate is disposed on the main body frame. The positioning plate is placed over the upper ends of the two vertical frames while the positioning plates are applied to the outer surfaces or the inner surfaces of the two opposed vertical frames. The injection molding machine according to claim 3 or 4, wherein a rod is protruded and a longitudinally long hole through which the horizontal rod is inserted is opened in the positioning plate.

Images