JPH0745146B2 - Manufacturing method of reflector for antenna - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a reflector for an antenna used for receiving satellite broadcasts and the like.

(Prior Art) In the above-mentioned parabolic antenna used for receiving satellite broadcasting, the reflector must have a predetermined strength and a radio wave reflection function, and also has a good weather resistance for outdoor installation. Sex is required.

Therefore, for example, in Japanese Patent Laid-Open No. 1-144704, the antenna body is installed in a mold, and a thin leaf body obtained by coating a weather-resistant film on a conductive metal sheet is used as a radio wave reflection member made of the conductive sheet. A technique is disclosed in which a layer is placed so as to be fitted to a reflection surface of an antenna body, and the antenna body and the thin leaf body are integrated by vacuum pressure forming to manufacture a parabolic antenna.

According to this, the antenna reflection plate including the radio wave reflection layer and the weather resistant layer covering the radio wave reflection layer can be manufactured all at once by the vacuum pressure forming step.

However, in the above reflection plate manufacturing method, the antenna main body and the thin leaf body are first manufactured in separate steps, and then the both are integrated by the vacuum pressure forming, so that the number of steps is increased and the cost is increased. As the temperature rises, the manufacturing becomes complicated and there is a drawback that it is not efficient.

For this, the fixed mold is clamped to the movable mold with the thermoplastic resin film having the radio wave reflection layer and the weather resistant layer adsorbed on the cavity forming surface of the movable mold, It is conceivable to inject the molten resin into the cavity from the side to form the antenna main body with the molten resin and at the same time to deposit the above resin film on the surface of the antenna main body. According to this method, it is not necessary to separately manufacture the antenna body, the manufacturing process of the reflector is simplified, and the cost is reduced.

(Problems to be solved by the invention) By the way, in the production of the reflector by the above-mentioned injection molding, the cavity forming surface of the movable die is a convex parabolic curved surface imitating the radio wave reflection surface of the reflector, and the movable die is The air between the resin film sent to the cavity and the cavity structure surface is evacuated and discharged, and the resin is injected while the resin film is adsorbed on the cavity structure surface, and the resin is heated by the heat and pressure of the injected resin. The film is deformed while being stretched so as to be completely adhered to the cavity forming surface, and in that state, the resin film A is coated on the surface of the resin molded product B which is the antenna body as shown in FIGS. 11 and 12. Will be dressed.

However, in the reflection plate C, the web E and the flange F (some of which have no flange) are usually provided on the periphery of the radio wave reflection surface D from the viewpoint of the strength of the main body. The resin film A will be adhered to the web E and the flange F, but in that case,
In the product, the seam G between the resin film A and the resin molded product B is exposed on the end surface of the flange F, and the resin film X may be peeled from the seam G.

Then, this invention makes it a subject to provide the manufacturing method of the reflector for antennas which does not expose the joint of an antenna main body and the resin film adhered to this on the end surface of a reflector.

(Means for Solving the Problem) That is, the present invention conveys a thermoplastic resin film in which a radio wave reflection layer and a weather resistant layer are laminated on one surface of a film substrate between a fixed mold and a movable mold. After clamping the fixed die and the movable die, a molten resin is injected from the fixed die into a cavity formed between the two dies to form an antenna body having a web portion around the radio wave reflection surface. A method for manufacturing an antenna reflector, in which the resin film is adhered to the surface of the antenna body, wherein the adsorption head is for cutting a film in the state where the film substrate side of the resin film is adsorbed to the adsorption head. By joining the molds,
A film cutting step of cutting out a resin film into a circular shape slightly larger than the radio wave reflection surface of the antenna body, and a film conveying step of carrying in the cut resin film on the front surface of the cavity forming surface of the movable mold while adsorbing it by the adsorption head And a film for separating the resin film from the suction head by bringing the suction head into pressure contact with a movable die, sandwiching the peripheral edge of the resin film between them, and sucking air between the cavity forming surface and the resin film. After the setting step and the suction head is retracted from the front position of the movable mold, the fixed mold and the movable mold are clamped together,
A mold clamping step of clamping the peripheral edge of the resin film, and a molten resin is injected from a fixed mold into a cavity formed between the two molds, and the peripheral edge of the clamped film is clamped by the pressure of the molten resin. A resin molding step in which the peripheral edge of the film is embedded on the inner surface of the outer peripheral edge of the web portion of the antenna main body so that the peripheral surface and the surface of the web portion are flush with each other by pulling out from the portion. It is characterized by consisting of and.

(Operation) According to the above method, the resin film is cut out into a circle having a size slightly larger than the radio wave reflection surface of the antenna body, and the cut out resin film has its peripheral edge when the fixed mold and the movable mold are clamped. The part is clamped and set between the fixed mold and the movable mold, and the peripheral edge of this film is pulled out from the clamp part by the pressure of the molten resin accompanying the injection from the fixed mold into the cavity and pushed into the cavity. The web portion is formed by covering the tip of the peripheral edge of the film with resin. Therefore, the resin film is embedded on the inner surface of the outer peripheral edge of the web portion so that the surface of the peripheral portion and the surface of the web portion are flush with each other. The joint with the body (resin molded product) is not exposed to the outside.

(Example) Next, the Example of this invention is described based on drawing.

FIG. 1 shows an injection molding die apparatus embodying the method of the present invention, in which a movable die 2 is disposed so as to be separable from and in contact with a fixed die 1, and at a position directly above both dies 1, 2. With the suction head 3 and the film preforming die 4 arranged, and the movable die 2 is separated from the fixed die 1, the suction head 3 can be moved up and down between a raised position shown by a solid line and a lowered position shown by a chain line. ing.

The adsorption head 3 adsorbs the thermoplastic resin film X described below in an ascended state, cuts the film X into a predetermined shape in cooperation with the film preforming die 4, preforms it, and performs a movable die after the preforming. 2 is moved down to the front surface and the resin film X is carried in.

Here, as an example of the resin film X, as shown in FIG. 2, a base material sheet X ₁ made of a resin of the same material as the injection resin, for example, a polystyrene resin, an aluminum sheet and an acrylic resin are used. It is conceivable that a sheet made of resin or the like is laminated by adhesion, and the radio wave reflection layer X ₂ made of the aluminum sheet is used as an intermediate layer, and the weather resistant layer X ₃ is formed thereon by an acrylic resin sheet.
Further, depending on the thickness of the aluminum sheet, an aluminum sheet reinforcing layer such as a polyester sheet may be provided between the reflective layer X ₂ and the weather resistant layer X ₃ . However, as long as the method of the present invention described later can be applied, the resin film X
Is not limited to the above. For example, the weather resistant layer X ₃ and the reflective layer X _{2 made of the} above acrylic resin sheet.
On the other hand, a resin film provided with an adhesive layer instead of the material sheet X ₁ can also be used as the resin film.

The suction head 3 is supported by an elevating table 5, and the elevating table 5 is connected with a piston rod 7 of a fluid pressure cylinder 6 whose upper end is connected to a fixing portion (not shown). The elevating table 5 is moved up and down by the expansion and contraction operation.

Further, the suction head 3 is configured to come into contact with and move away from the movable die 2 in a lowered state, so that the rods 8 and 8 connected to the back surface of the suction head 3 are laterally attached to the lifting table 5 as shown in FIG. In addition to being slidably supported, the lift table 5 is equipped with solenoids 9 and 9 for pushing and pulling these rods 8 and 8. The excitation head 3 contacts the movable die 2 by exciting the solenoids 9 and 9. The movable member 2 is moved in the direction and is returned to the direction in which it is separated from the movable mold 2 by the force of the spring members 10 and 10 when the excitation is released.

In addition, the film preforming die 4 described above is attached to the suction head 3.
A large number of small-diameter air holes 11 are formed on the film suction surface 3a facing the ...
11 are opened at equal pitches, and these ventilation holes 11 ... 11 are connected to an air flow path 12 formed inside the suction head, and an air hose 13 is connected to this air flow path 12. The air hose 13 is switched and connected to the vacuum pump 15 and the compressor 16 by a three-way switching valve 14. The vacuum pump 15 applies an air suction force to the adsorption head 3 via the air hose 13 to adsorb the resin film X to the adsorption head, and the compressor 16 sends compressed air to the adsorption head 3 to cause a film vacuum described later. Resin film X adsorbed during pressure molding
Is released from the suction head 3 by pressure. The film suction surface 3a is coated with Teflon in order to ensure good film releasability at the time of vacuum vacuum forming of the film.

Further, the film suction surface 3a of the suction head 3 is provided with
And a flat portion 18 that surrounds the convex base portion 17, and a peripheral portion of the convex base portion 17 is a curved portion 17a that is continuous with the flat portion 18,
Further, the outer corner portion of the flat portion 18 is used as an edge portion 19 for cutting the film.

In addition, in the suction head 3, a clamp plate is provided so as to surround the film suction surface 3a composed of the convex base portion 17 and the flat portion 18.
20 is attached, and this clamp plate 20 is a spring member 21, 21
Is always urged toward the film preforming die 4 side with respect to the suction surface 3a.

On the other hand, the film preforming die 4 is composed of a holder 22 and a die body 23 built in the holder 22. The holder 22 is supported by a support frame 24 via a fluid pressure cylinder 25A, and the holder 22 is Locating pin 26 on top of
Is projected. The mold body 23 is a fluid pressure cylinder 25B.
The mold main body 23 includes a film molding portion 27 that can be protruded and retracted from the holder 22 by the projection 22, and that is fitted with the convex base portion 17 of the suction head 3 and a film molding portion 28 that is in contact with the flat portion 18. An inner corner portion of the holder 22 that is formed by recessing in the front surface of the mold body 23 and surrounds the die body 23 serves as an edge portion 29 for cutting a film.

The film preforming die 4 is brought into and out of contact with the suction head 3 by the operation of the fluid pressure cylinders 25A and 25B. In preparation for this joining, the head 3 is raised to the suction head 3 side. At this time, the groove 30 that engages with the support frame 24
And a pin hole 31 into which the positioning pin 26 projects.

In the fixed die 1 and the movable die 2 described above, the fixed die 1 is a fixed platen.
32, the movable die 2 is attached to the movable plate 33, and the movable plate 33 is fixed to the fixed plate 32 by the fluid pressure cylinders 34, 34.
The movable mold 2 and the fixed mold 1 are moved by moving them away from each other.
And are opened and closed using a tie bar (not shown) as a guide. When the two molds 1 and 2 are joined, a parabolic antenna-shaped cavity is formed between the molds.

In the fixed mold 1 described above, as shown in FIG. 4, the cavity plate 35 is held by the support block 36, and the cavity plate 35 is surrounded by the mold matching surface 37 of the support block 36 and has a concave curved cavity forming surface 38. And a gate for resin injection is opened in the cavity forming surface 38, while a spool bush 39 provided in the support block 36 is formed.
The sprue 40 is communicated with the gate, whereby the molten resin supplied from the injection nozzle 41 to the sprue 40 is injected into the aforementioned cavity from the gate.

Further, on the cavity forming surface 38, the flange portion Yb of the reflector main body shown in FIG.
An annular recess 42 for forming a portion (corresponding to the flange F in the figure) is formed.

In the movable mold 2, the cavity plate 43 is held by the support block 44, and the cavity plate 43
In addition, a convex curved cavity forming surface 45 facing the cavity forming surface 38 of the fixed mold 1 is formed. Further, the ring block 46 is fitted onto the cavity plate 43. On the other hand, a plurality of recesses 44a, 44a are formed on the back surface of the support block 44 at positions surrounding the cavity plate 43, and one ends of slide rods 47, 47 penetrating the support block 44 back and forth engage with these recesses 44a, 44a. Being these slide rods 4
With 7,47 being able to slide back and forth by a certain amount,
The other ends of these slide rods 47, 47 are connected to the ring block 46. In that case, spring members 47a, 47a are provided between the support block 44 and the ring block 46,
The ring block 46 is urged so as to project toward the fixed mold 1 side with respect to the cavity plate 43.

Further, a film suction portion 49 (in order to clarify the existence of this suction portion 49 is shown by a concave shape in FIG. 7 and FIG. 8 on the mold matching surface 48 surrounding the cavity plate 45 of the ring block 46). Is formed),
A concave portion 50 continuous with the film suction portion 49 is formed on the inner peripheral surface of the ring block 46, and the ring block 4 is resisted against the spring members 47a, 47a by clamping the fixed die 1 and the movable die 2 together.
When the 6 is retracted, the recessed portion 50 is formed so as to be continuously connected to the peripheral portion of the cavity forming surface 45 (state shown in FIG. 8). It should be noted that the recessed portion 50 is formed by the resin Ya when the resin is being formed.
The part corresponding to) is for molding.

In the movable mold 2, the air suction passages 51 and 52, which open to the cavity forming surface 45 through the sliding contact portion between the cavity plate 43 and the ring block 46, and open in the film suction portion 49, are provided at regular intervals in the circumferential direction. It is provided. The air suction passages 51 and 52 are guided to the back of the cavity plate 43 and communicated with an air suction means (not shown) via an annular air passage 53 provided in the portion.

Next, a molding operation in the mold device having the above structure will be described.

As shown in FIG. 1, the stationary die 1 and the movable die 2 are separated from each other with a constant space, and the suction head 3 is in the raised position. In this standby state, the support frame 24 is engaged with the engaging groove 30 of the suction head 3 as shown in FIG. 3, and the suction head 3 is positioned with respect to the film preforming die 4.

From this state, on the front surface of the suction head 3 and the preforming die 4
And the thermoplastic resin film X is supplied by an appropriate means. With the supply, the three-way switching valve 14 connects the vacuum pump 15 to the suction head 3 to apply an air suction force to the head, thereby causing the suction head 3 to move. Suction air through the ventilation holes 11 ... 11,
The resin film X is adsorbed to the film adsorption surface 3a by the adsorption force. In addition, this adsorption is the base sheet of the resin film X.
It is performed so that X ₁ is brought into close contact with the adsorption surface 3a.

After the suction, the film preforming die 4 is advanced with respect to the suction head 3 by the operation of the fluid pressure cylinder 25A, the positioning pin 26 is projected into the pin hole 31, and the preforming die 4 and the suction head 3 are aligned. Both are joined together in the closed state.

In this joining, first, the peripheral portion of the resin film X is sandwiched between the clamp plate 20 on the suction head 3 side and the holder 22, and the holder 22 further advances to retract the clamp plate 20 against the spring member 21. As a result, the flat portion 18 and the respective edge portions 19 and 29 of the holder 22 are engaged with each other, and the resin film X is cut around the film suction surface 3a. And
After that, the fluid pressure cylinder 25B is operated, the die main body 23 is moved forward, and the film forming portions 27 and 28 are fitted to the convex base portion 17 and the flat portion 18, as shown in FIG. Molding for X is done.

With this molding, as shown in FIG. 6, the resin film X is cut out into a circle that is slightly larger than the radio wave reflection surface of the antenna body, and a curved portion Xa and a flat portion Xb are formed in the peripheral portion of the cut out resin film X. Is imprinted.

Next, as the film preforming die 4 is moved backward and separated from the suction head 3, the suction head 3 descends to the position of the chain line in FIG. 1 while adsorbing the preformed resin film X, The resin film X is carried in on the front surface of the movable mold 2.

Then, the solenoids 9 and 9 are excited, and the suction head 3 moves forward toward the movable mold 2 and comes into close contact therewith. As a result of this contact, the flat portion 18 and the clamp plate 20 contact the ring block 46 as shown in FIG.
The projecting state is maintained by the force of 47a and it does not retreat. The preformed curved portion Xa of the resin film X is fitted into the concave portion 50 of the movable die 2, and the flat portion Xb is fed to the front surface of the cavity forming surface 45 in close contact with the film suction surface 149.

From this state, the vacuum pressure molding of the resin film X is performed. That is, in the movable mold 2, the air suction means is operated,
The air between the resin film X and the cavity constituting surface 45 is discharged to the outside from the air passage 53 through the air suction passages 51 and 52. Then, after the space between the resin film X and the cavity forming surface 45 is evacuated, compressed air is sent from the compressor 16 to the suction head 3 through the air hose 13 by switching the three-way switching valve 14 in the suction head 3. Air is ejected from the ventilation holes 11 ... 11. Therefore, the suction action due to the vacuum being drawn between the resin film X and the cavity constituting surface 45 and the air pressure blown from the suction head 3 separates the resin film X from the film sucking surface 3a and presses it against the cavity constituting surface 45. By the action, the resin film X is adsorbed in a state of substantially following the cavity forming surface 45. Since the base material sheet X ₁ side of the resin film X was adsorbed by the adsorption head 3, the weather resistant layer X ₃ faces the cavity constituting surface 45.

After the vacuum pressure forming, the suction head 3 retracts and rises. However, in the movable mold 2, the air suction force by the air suction means is continuously exerted between the resin film X and the cavity forming surface 45 to maintain the suction state of the film, and the air suction is continued until the injection of the molten resin is completed. Let
Therefore, the flat portion Xb of the preformed peripheral portion of the resin film X is attracted to the film attracting surface 49 of the movable die 2, and the curved portion Xa is continuously attracted to the concave portion 50.

After the suction head 3 is lifted, the fixed die 1 and the movable die 2 are clamped. By this mold clamping, the ring block 46 is retracted against the spring members 47a, 47a, and the recessed portion 50 is continuously connected to the convex curved surface of the cavity forming surface 45 as shown in FIG. Further, in the clamped state, the flat portion Xb of the resin film X is
Are clamped by the film suction surface 49 of the movable mold 2.
However, the clamping force at this portion does not prevent the flat portion Xb from being dragged into the cavity during the resin injection described below. Then, the molten resin Y is injected from the gate into the cavity, and the heat and pressure at that time cause the resin film X to completely adhere to the cavity constituting surface 45 while exhibiting an appropriate expansion, and in this state, the antenna body is resin-molded. In this molding, the base material sheet X ₁ of the resin film X is melted and integrated with the injection resin, so that the resin film X is attached to the antenna body (resin molded product) (see FIG. 9). Shown).

By the way, during the above resin injection, the preformed flat portion Xb of the resin film X is clamped by the molds 1 and 2 on the film suction surface 49 of the movable mold 2. However, when the resin is injected into the cavity, The flat portion Xb is pulled out from the clamp portion by the pressure of the resin and dragged into the concave portion 50 in the cavity. Therefore, the resin Y is molded so as to cover the film tip Xc of the flat portion Xb as shown in FIG. 9, and in the obtained product, the resin film X is more than the outer peripheral edge of the web Ya. Since the surface of the film peripheral edge and the surface of the web portion are embedded in the inner surface so as to be flush with each other, the joint between the resin film X and the molding resin Y is not exposed to the outside. As a result, in the manufactured antenna reflector, the resin film X is not peeled off from the joint.

In the resin molding in the above embodiment, the antenna body was provided with the web Ya and the flange Yb, but it is also possible to provide only the web Ya, in which case the shape shown in FIG. 11 is an example. Considered as.

(Effect of the Invention) As is clear from the above description, according to the present invention,
The resin film is cut into a circle that is slightly larger than the radio wave reflection surface of the antenna body, and the cut resin film is clamped at the peripheral edge of the film when the fixed mold and the movable mold are clamped. The peripheral edge of the film is pulled out from the clamp part by the pressure of the molten resin that accompanies injection from the fixed mold into the cavity and is pushed into the cavity. The web portion is molded. Therefore, the resin film is embedded on the inner surface of the outer peripheral edge of the web portion so that the surface of the peripheral portion and the surface of the web portion are flush with each other. Main body (resin molded product)
The joint with is not exposed to the outside. Therefore, there is no possibility that the resin film is peeled off from the seam, and the product quality is improved.

[Brief description of drawings]

The drawings show an embodiment of a method for manufacturing a reflection plate for an antenna according to the present invention. FIG. 1 is a schematic configuration diagram of a resin injection molding die apparatus embodying the method of the present invention, and FIG. 2 is used for the method of the present invention. FIG. 3 is an enlarged view of the suction head portion in FIG. 1, FIG. 4 is an enlarged view of the mold in FIG. 1, and FIGS. 5 to 9 are explanatory views of the molding operation. FIG. 5 is a film preforming operation explanatory view, FIG.
FIG. 7 is a cross-sectional view of a preformed resin film, FIG. 7 is an explanatory view of a film suction operation on a movable mold, FIG. 8 is an explanatory view of a mold clamping operation, FIG. 9 is an explanatory view of resin injection molding operation, and FIG. FIG. 7 is a cross-sectional view showing a modified example of the antenna reflection plate. FIG. 11 is a perspective view of a reflector for an antenna manufactured by the prior art, and FIG. 12 is an enlarged cross-sectional view of the main part of the reflector. X ... Resin film, Xa, Xb ... Film peripheral portion (Xa is curved portion, Xb is flat portion), Y ... Molten resin, Ya ... Web, 1 ...
Fixed type, 2 movable type, 3 suction head, 4 film forming type, 45 cavity forming surface.

Continuation of the front page (56) Reference JP-A 64-89603 (JP, A) JP-A 1-151306 (JP, A) JP-A 61-63425 (JP, A) JP-A 62-196113 (JP , A)

Claims (1)

[Claims] 1. A thermoplastic resin film having a radio wave reflection layer and a weather resistant layer laminated on one surface of a film substrate between a fixed die and a movable die to convey the fixed die and the movable die. After tightening, molten resin is injected from the fixed mold into the cavity formed between the two molds to mold the antenna main body having the web portion around the radio wave reflection surface, and the above-mentioned structure is formed on the surface of the antenna main body. A method of manufacturing a reflector for an antenna, comprising depositing a resin film, comprising: adhering a film cutting die to the adsorption head while adsorbing the film substrate side of the resin film to the adsorption head. And a film cutting step of cutting out the above into a circular shape slightly larger than the radio wave reflection surface of the antenna body, and a cavitation in a movable type while the cut out resin film is sucked by the suction head. A film conveying step of carrying in the front surface of the constituent surface, and the suction head is brought into pressure contact with a movable mold so as to sandwich the peripheral edge portion of the resin film therebetween, and sucks air between the cavity constituent surface and the resin film. And a film setting step of separating the resin film from the suction head, and after retracting the suction head from the front position of the movable mold, the fixed mold and the movable mold are clamped, and the peripheral portion of the resin film is clamped. In the mold clamping step, the molten resin is injected from the fixed mold into the cavity formed between the two dies, and the peripheral edge of the film clamped by the pressure of the molten resin is pulled out from the clamp portion, thereby the peripheral edge of the film. The inner surface of the antenna body with respect to the outer peripheral edge of the web portion, and the surface of the peripheral portion and the surface of the web portion are flush with each other. Method for producing antenna reflector which characterized by comprising a resin molding step of embedded cormorants.