JP5262954B2 - Injection molding apparatus, method for manufacturing molded body, and molded body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress poor weld in jointing two molded bodies. <P>SOLUTION: This injection molding equipment for forming the molded body 300a transmitting laser beams includes: a female mold 400 for forming a cavity 310 for filling a material; a male mold 500; a main gate 407 provided in either of the female mold 400 or the male mold 500 to fill the material in the cavity 310; and a valve gate 447 provided in either of the female mold 400 or the male mold 500 and connected to a cavity end part 315 which is an end of the cavity 310 to form a connection part 325 for connecting the molded body formed by the cavity 310 with another molded body by laser welding. After the material is filled in the cavity 310 from the main gate 407, the material is filled from the valve gate 447 with respect to the cavity 310 in the direction opposite to the filling direction of the material from the main gate 407, to push back a nontransparent portion generated during the material filling from the main gate 407 to the main gate side. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a molded body used for a tank or the like, a manufacturing method thereof, and a manufacturing apparatus.

  The liner for the tank can be formed, for example, by forming a pair of semi-hollow bodies by injection molding and joining them. Here, when forming a semi-hollow body by injection molding, a technique is known in which a joint for joining with another semi-hollow body is not bent (for example, Patent Document 1).

JP 2003-112332 A

  However, in the prior art, the non-transparency of the resin generated during the injection molding has not been sufficiently studied. That is, when forming a transparent semi-hollow body, a transparent resin is injected into the mold cavity. At this time, a part of the resin may be altered by heat and become opaque. If this non-transparent resin is present at the joint end with the other semi-hollow body, even if two laser beams are used to weld the two semi-hollow bodies, the laser light is blocked by the non-transparent resin, The laser beam does not reach the joint surface between the two half-hollow bodies. As a result, there has been a problem that poor welding of the two semi-hollow bodies occurs. Such a problem is not limited to a hollow molded body, and is generally a problem common to the formation of a transparent molded body.

  An object of the present invention is to solve at least a part of the above-described problems and suppress the occurrence of poor welding in the joining of two molded bodies.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
An injection molding apparatus for forming a molded body that transmits laser light, a female mold for forming a cavity for injecting a material, a male mold, the female mold, and a male mold A main gate for injecting material into the cavity, the female mold, and a valve gate provided in any of the male molds, at the end of the cavity. A valve gate connected to a cavity end for forming a connection part for connecting the molded body formed by the cavity and another molded body by laser welding, and material from the main gate to the cavity After the injection of the material into the cavity from the valve gate in the direction opposite to the direction of the material injection from the main gate, the non-transparency caused at the time of material injection from the main gate Pushing back the partial to the main gate side, the injection molding apparatus.
According to this application example, the non-transparent portion can be pushed back from the connection portion to the main gate side, and the non-transparent portion can be eliminated from the end portion for forming the connection portion. It becomes possible to suppress the occurrence of poor welding in joining the bodies.

[Application Example 2]
In the injection molding apparatus according to Application Example 1, the timing for starting injection of wood charge to the cavity from the valve gate, when injected material from the main gate has reached the cavity end of the valve near the gate Is an injection molding device.
According to this application example, the material injected from the valve gate is associated with the material injected from the main gate in a state of high temperature and fluidity. Therefore, it is easy to suppress the occurrence of welds.

[Application Example 3]
The injection molding apparatus according to Application Example 1 or Application Example 2 further includes a sensor for detecting an injection state of material from the main gate to the cavity, and the injection molding apparatus receives a signal from the sensor. An injection molding device used to start injecting material from the valve gate.
According to this application example, it is possible to easily obtain the timing of starting the injection of material from the valve gate.

[Application Example 4]
In the injection molding apparatus according to Application Example 3, the sensor is a pressure sensor, and the injection molding apparatus detects the valve gate when a pressure measured by the pressure sensor is equal to or higher than a predetermined pressure. Injection molding device that starts injecting material from.
For example, a pressure sensor can be used as the sensor.

[Application Example 5]
In the injection molding apparatus according to Application Example 1, the timing of the injection molding apparatus starts injecting wood charge to the cavity from the valve gate is predetermined from the start of the injection of material into the cavity from the main gate The injection molding device when the time has passed.
According to this application example, the sensor can be omitted.

[Application Example 6]
A method of manufacturing a molded body that transmits laser light, comprising: (1) a step of closing a mold; (2) a step of injecting a material from a main gate into a cavity of the mold; and (3) an end of the cavity. The material from the main gate to the cavity from the valve gate connected to the end of the cavity forming a connecting portion that connects the molded body formed by the cavity and the other molded body by laser welding A step of pushing back a non-transparent portion of the material generated at the time of material injection from the main gate toward the main gate by injecting the material in a direction opposite to the injection direction; and (4) opening the mold and forming the molded body A method for producing a molded body comprising:
According to this application example, the non-transparent portion can be pushed back from the connection portion to the main gate side, and the non-transparent portion can be eliminated from the end portion for forming the connection portion. It becomes possible to suppress the occurrence of poor welding in joining the bodies.

[Application Example 7]
A molded body made of a material that transmits laser light, and has an end connected to another molded body by laser welding, and is generated when the molded body is formed. A molded body having a transparent portion at a position away from the end.
According to this application example, since the non-transparent portion is not provided at the end portion but at a position away from the end portion, it is possible to suppress the occurrence of poor welding in joining the two molded bodies by laser light. Is possible.

[Application Example 8]
The molded body according to Application Example 7, wherein the molded body is a hollow molded body, and includes a first portion having a cylindrical shape and a second portion having a ring shape along a conical surface, One end is connected to one portion, the second portion is inclined so that the normal line in the ring shape intersects outside the hollow molded body, and one end is connected to the other end of the second portion, and the outside Is a third part having a ring shape formed with a convex curved surface, and a fourth part having a hollow cylindrical shape in which one end is connected to the other end of the third part and forms the outermost side wall of the hollow molded body. The end portion is formed at the other end of the fourth portion, and the non-transparent portion is provided in a portion excluding the end portion of the fourth portion. The molded body.
According to this application example, the non-transparent portion is provided in the portion excluding the end portion of the fourth portion joined to the other molded body.

  The present invention can be realized in various forms. For example, in addition to an injection molding apparatus, the present invention can be realized in various forms such as a method for manufacturing a molded body and a molded body.

It is explanatory drawing which shows the external appearance of the tank produced in one Example of this invention. It is explanatory drawing which shows the cross section of a tank. It is explanatory drawing explaining the manufacturing process of a tank. It is explanatory drawing which shows joining by a laser beam. It is explanatory drawing which shows the female metal mold | die of the injection molding apparatus for forming the division | segmentation liner 300a. It is explanatory drawing which shows the male metal mold | die of the injection molding apparatus for forming the division | segmentation liner 300a. It is explanatory drawing which shows the state which closed the metal mold | die. It is explanatory drawing which expands and shows the part shown with the broken line W1 of FIG. It is explanatory drawing which shows the state which started injecting resin from the resin injection apparatus 410. FIG. It is explanatory drawing which shows the state which the front-end | tip part of resin reached the position of the pressure sensor. It is explanatory drawing which shows the state which started pouring resin from the resin injection apparatus 420 in reverse direction. It is explanatory drawing which shows the division | segmentation liner 300a taken out from the metal mold | die. It is explanatory drawing which shows the connection edge part part 315 vicinity when filling the cavity in the cavity in a comparative example. It is explanatory drawing which compares the laser welding of the division | segmentation liner 300a300b in a present Example and a comparative example.

  FIG. 1 is an explanatory diagram showing the appearance of a tank created in one embodiment of the present invention. FIG. 2 is an explanatory view showing a cross section of the tank. The tank 10 includes a base 100, an outer cylinder 200, and a liner 300. The base 100 is used for filling the tank 10 with gas or discharging the gas from the tank 10. A flange 110 (flange) is formed on the outer periphery of the base 100 near the center in the direction of the central axis 101 of the base 100. The collar 110 is formed to protrude to the outer periphery along a plane perpendicular to the central axis 101. Further, the flange 110 has a tapered shape or a substantially trapezoidal shape such that the tip end side of the flange is thin.

  The liner 300 is an inner shell for sealing the inside of the tank. The liner 300 has a substantially cylindrical shape. Here, the liner 300 includes two divided liners 300a and 300b. A base 100 is attached to the upper and lower portions of the liner 300. Note that the base 100 may be provided only in one split liner 300a, and the base 100 may not be provided in the other split liner 300b. The liner 300 is made of a heat-shrinkable material such as nylon, ethylene vinyl alcohol copolymer (EVOH), or polyethylene. The configuration of the liner 300 may include a plurality of layers including an outer layer made of a heat-shrinkable material and an inner layer made of a non-heat-shrinkable material such as epoxy, glass, or metal. .

  The outer cylinder 200 is formed outside the liner 300 and functions as a pressure-resistant shell of the tank 10. As a material of the outer cylinder 200, fiber reinforced plastic (FRP) can be used. The end portion of the liner 300 and the end portion of the outer cylinder 200 are in close contact with each other so as to sandwich the flange 110 of the base 100, and gas leakage from the joint portion between the base 100 and the liner 300 is suppressed. In FIG. 1, the liner 300 is covered by the outer cylinder 200.

  FIG. 3 is an explanatory diagram for explaining a manufacturing process of the tank. First, as shown in FIG. 3A, a base 100 and a split liner 300a are prepared. For example, the split liner 300a is manufactured using, for example, an injection molding apparatus. The process of manufacturing the divided liner 300a will be described later. The split liner 300a has a cylindrical shape, and one opening 305 of the split liner 300a is narrowed. The base 100 is joined to the narrowed opening 305.

  Next, as shown in FIG. 3B, the base 100 is press-fitted into the opening 305 of the split liner 300a. Next, as shown in FIG. 3C, the divided liner 300a is heat-treated. Thereby, the split liner 300a is thermally contracted, and the end portion of the split liner 300a and the flange 110 of the base 100 are joined. When the split liner 300a includes a plurality of layers, the split liner 300a is preferably formed so that the end of the outer layer of the split liner 300a is positioned above the flange 110. In this way, when the divided liner 300a is thermally contracted, the outer layer of the divided liner 300a is applied to the upper side of the flange 110. As a result, since the brim 110 is sandwiched between the inner layer and the outer layer, the joint between the brim 110 and the divided liner 300a is strengthened. Similarly, the divided liner 300b having the base 100 is manufactured.

  Next, as shown in FIG. 3D, the divided liners 300a and 300b to which the cap 100 is attached are joined. Specifically, the opposite sides of the divided liners 300a and 300b on the side where the cap 100 is attached are aligned. Next, for example, a laser torch is used to irradiate the joint between the two divided liners 300a and 300b. As a result, the resin at the joint between the two divided liners 300a and 300b is heated to weld the two divided liners 300a and 300b. In the present embodiment, one of the divided liners 300a is formed of a laser light transmissive resin, and the other divided liner 300b is formed of a laser light non-transmissive resin. Therefore, the split liner 300a is transparent to the laser light, and the split liner 300b is non-transparent. The laser light passes through the split liner 300a and is absorbed by the split liner 300b. As a result, the temperature of the split liner 300b is increased due to the energy of the laser beam. This facilitates the welding of the divided liner 300a and the divided liner 300b. Further, in this case, it is preferable that the resin material of the divided liner 300a and the divided liner 300b is the same, and a pigment is added to the resin material of one of the divided liners 300b so that the laser light absorbability is provided. This is because if the material of the divided liner 300a and the divided liner 300b is the same, no difference in strength occurs between the divided liner 300a and the divided liner 300b. As the pigment, for example, carbon black or ferrous oxide (FeO) can be used.

  Next, as shown in FIG. 3E, the reinforcing fiber impregnated with the resin is wound around the liner 300. As fibers for reinforcing the resin, glass fibers, carbon fibers, and aramid fibers (for example, polyparaphenylene terephthalamide fibers (Kevlar fiber, Kevlar is a registered trademark)) can be used. In addition, as a resin reinforced with fibers, an epoxy resin, an epoxy acrylate resin, or a polyester resin can be used. In addition, it is possible to adjust mechanical properties, such as tensile strength of the outer cylinder 200, with the pattern of the reinforcing fiber winding. Next, as shown in FIG. 3F, the reinforcing fibers wound around the liner 300 are heat-cured. Thereby, the reinforced fiber impregnated with the resin becomes FRP and forms the outer cylinder 200. In the present embodiment, the step of winding the reinforcing fiber impregnated with resin around the liner 300 and then heat-curing it to obtain the outer cylinder 200 is called a filament winding step.

  FIG. 4 is an explanatory view showing bonding by laser light. FIG. 4A is an explanatory view showing a state in which the opposite sides of the split liners 300a and 300b to which the cap 100 is attached are combined. FIG. 4B is an explanatory diagram showing, in an enlarged manner, a portion surrounded by a broken line V1 in FIG. FIG. 4C is an explanatory view of the portion shown in FIG. 4B viewed from the radial direction of the liner. In the joint portion, at the joint portion between the two split liners 300a and 300b, the split liner 300a formed of the laser light transmitting resin is positioned on the outer side, and the split liner 300b formed of the laser light non-transmitting resin is positioned on the inner side. Yes.

  As shown in FIG. 4B, the joint surfaces 301 of the split liners 300a and 300b are inclined with respect to the direction of the cylinders of the split liners 300a and 300b. By making the joining surface 301 oblique in this way, it is possible to increase the contact area between the two divided liners 300a and 300b. Moreover, it is preferable that the joining surface 301 is flat. When joining the divided liners 300a and 300b, laser light is irradiated from the laser light irradiation area 302 on the divided liner 300a toward the bonding surface 301. The laser light reaches the bonding surface 301. Here, since the divided liner 300b is formed of a laser beam non-transmissive resin, it absorbs the energy of the laser beam and generates heat. The split liners 300a and 300b are melted and welded at the joint surface 301 by this heat.

  By the way, the divided liners 300a and 300b are generally formed by injection molding in which a resin is injected into a cavity of a mold. When performing injection molding, a part of the resin may be changed by heat to become non-transparent. This non-transparent portion 303 is generally likely to occur at the front end of the resin flow. Since the split liner 300b contains a pigment, there is no problem even if the resin becomes non-transparent at the time of injection molding. However, since the divided liner 300a is transparent, a problem may occur depending on the position where the non-transparent portion 303 occurs. That is, when the non-transparent portion 303 is present at the joint with the split liner 300b, the laser light is blocked by the non-transparent portion 303, so that the laser light does not reach the joint surface 301 and the split liners 300a and 300b are welded. It may become defective. Therefore, as shown in FIG. 4B, it is preferable to form the split liner 300a so that the non-transparent portion 303 exists at a position other than the joint portion even if the non-transparent portion 303 occurs.

  FIG. 5 is an explanatory view showing a female mold of an injection molding apparatus for forming the divided liner 300a. The female mold 400 is used as a fixed mold when the divided liner 300a is manufactured. FIG. 5A is an explanatory view showing a cross section of the female mold 400. The female mold 400 includes a recess 401, a runner 405, resin injection devices 410 and 420, a valve device 430, and a groove 445. The concave portion 401 receives the convex portion of the male mold to be paired. The runner 405 is a resin flow path. The resin injection device 410 is connected to the bottom of the recess 401 via a runner 405. The resin injection device 420 and the valve device 430 are disposed in the side surface direction of the recess 401. The valve device 430 is connected to the resin injection device 420. The valve device 430 includes a runner 435 and a needle 440. By moving the position of the needle 440, it is possible to control the presence or absence of resin passing through the valve device 430. The groove 445 is connected to the valve device 430 and the side surface of the recess 401.

  FIG. 5B is an explanatory diagram when the female mold 400 shown in FIG. 5A is viewed from above. In FIG. 5B, the runner 405 and the groove 445 are shown through. In the present embodiment, the runner 405 branches in 8 directions. It should be noted that various values can be adopted for the number of branches. In the present embodiment, four valve devices 430 and four grooves 445 are provided, but various values can be adopted for this number.

  FIG. 6 is an explanatory view showing a male mold of an injection molding apparatus for forming the divided liner 300a. The male mold 500 is used as a moving mold. A convex portion 501 having a cylindrical shape and a pressure sensor 510 are provided. The pressure sensor 510 is disposed at the base of the convex portion 501. Note that it is possible to freely select which of the female mold and the male mold is the fixed mold and the movable mold. In this embodiment, the resin injection devices 410 and 420, the runner 405, the valve device 430, and the groove 445 are provided in the female die 400, but may be provided in the male die 500. Alternatively, the resin injection device 410 and the runner 405 may be provided in the female die 400, and the resin injection device 420, the valve device 430, and the groove 445 may be provided in the male die 500 in a dispersed manner.

  FIG. 7 is an explanatory view showing a state in which the mold is closed. A cavity 310 is formed between the concave portion 401 (see FIG. 4) and the convex portion 501 (see FIG. 5). The cavity 310 includes four cavity portions 311 to 314. The first cavity portion 311 is on the center side and has a hollow cylindrical shape. One end of the second cavity portion 312 is connected to the end of the first cavity portion 311. The second cavity portion 312 has a ring shape along the conical surface. The ring shape of the second cavity portion 312 is inclined so that the normal line 312 a in the ring shape intersects outside the cavity 310. The inclination preferably coincides with the inclination of the taper shape or the substantially trapezoidal shape of the flange 110 of the base 100. This makes it possible to strengthen the bonding between the liner 300 formed in the cavity 310 and the flange 110. One end of the third cavity portion 313 is connected to the other end of the second cavity portion 312. The third cavity portion 313 has a ring shape formed with a convex curved surface on the outside. The fourth cavity portion 314 is connected to the other end of the third cavity portion 313. The fourth cavity portion 314 is on the outermost periphery of the cavity 310 and has a hollow cylindrical shape. A runner 405 is connected to a connection position between the second cavity portion 312 and the third cavity portion 313. From here, resin is injected into the cavity 310. The boundary between the runner 405 and the cavity 310 is called a “main gate 407”. Further, a boundary where the female mold 400 and the male mold 500 are in contact is referred to as a “parting line 450”. The valve mechanism 430 described above is adjacent to the parting line 450.

  FIG. 8 is an explanatory diagram showing, in an enlarged manner, a portion indicated by a broken line W1 in FIG. The other end of the fourth cavity portion 314 that is not connected to the third cavity portion 313 is referred to as a “connection end portion 315”. The connection end portion 315 is used for joining with the split liner 300b (see FIG. 4). The groove 445 is connected to the connection end portion 315. When the female mold 400 and the male mold 500 are closed, the groove 445 functions as a runner. The pressure sensor 510 is disposed at the connection end portion 315. The boundary between the groove 445 and the connection end portion 315 is referred to as a “valve gate 447”.

  FIG. 9 is an explanatory view showing a state in which resin is started to be injected from the resin injection device 410. FIG. 9A is an explanatory diagram showing an overall view of the mold, and FIG. 9B is an explanatory diagram showing an enlarged vicinity of the front end portion of the resin 700 (portion surrounded by a broken line X1). The female mold 400 moves the needle 440 of the valve device 430 and closes the valve device 430. Next, the resin 700 is injected into the cavity 310 from the runner 405 through the main gate 407 (see FIG. 7). At this time, as shown in FIG. 9B, a part of the resin in the vicinity of the front end portion 705 of the resin may be denatured to generate a non-transparent portion 303.

  FIG. 10 is an explanatory diagram showing a state where the tip of the resin has reached the position of the pressure sensor. FIG. 10A is an explanatory diagram showing an overall view of the mold, and FIG. 10B is an explanatory diagram showing an enlarged view of the vicinity of the tip of the resin 700 (portion surrounded by a broken line Y1). As shown in FIG. 10B, the non-transparent portion 303 exists in the connection end portion 315. Further, the number of non-transparent portions 303 is larger than that shown in FIG. In the state shown in FIG. 10B, the tip portion 705 of the resin 700 is in contact with the pressure sensor 510. For this reason, the pressure sensor 510 can detect the pressure from the resin 700. When this pressure is detected, the female mold 400 moves the needle 440 of the valve device 430 and opens the valve device. Then, the resin 710 is injected from the resin injection device 420 into the connection end portion 315 of the cavity 310 through the valve device 430 and the groove 445. The injection direction of the resin 710 at this time is opposite to the direction in which the resin 700 flows.

  FIG. 11 is an explanatory view showing a state in which the resin injection starts from the resin injection device 420 in the reverse direction. FIG. 11A is an explanatory diagram showing an overall view of the mold, and FIG. 11B is an explanatory diagram showing an enlarged view of the vicinity of the boundary between the resins 700 and 710 (portion surrounded by the broken line Z1). It can be seen that the front end portion 705 of the resin 700 is pushed back by the resin 710. As a result, the non-transparent portion 303 moves to a position away from the connection end portion 315 in the fourth cavity portion 314. In addition, the line which shows the front-end | tip part 705 of the resin 700 is drawn for convenience of explanation, and it is preferable that this front-end | tip part 705 is actually invisible.

  FIG. 12 is an explanatory view showing the divided liner 300a taken out from the mold. The split liner includes a first portion 321 to a fourth portion 324. These four portions 321 to 324 correspond to the first to fourth cavity portions 311 to 314, respectively. A connection end portion 325 is formed from the connection end portion 315 of the fourth cavity portion 314. Note that the connection end 325 is a part of the fourth portion 324. The front end portion 705 of the resin 700, that is, the boundary between the resin 700 and the resin 710 exists at a position excluding the connection end portion 325 of the fourth portion 324. The non-transparent portion 303 is also present at a position excluding the connection end 325 of the fourth portion 324.

  FIG. 13 is an explanatory view showing the vicinity of the connection end portion 315 when the cavity is filled with resin in the comparative example. The mold in the comparative example does not include the valve device 430, the groove 445, and the valve gate 447. Therefore, the injection direction of the resin 700 is one direction, and the resin 700 is not pushed back, so that the non-transparent portion 303 may exist in the connection end portion 315.

  FIG. 14 is an explanatory diagram for comparing laser welding of the divided liners 300a and 300b in the present embodiment and the comparative example. FIG. 14A is an explanatory diagram showing this embodiment, and FIG. 14B is an explanatory diagram showing a comparative example. In this embodiment, since there is no non-transparent portion 303 at the connection end 325, the laser light reaches the joint surface 301 of the two divided liners 300a and 300b. As a result, the temperature of the resin forming the split liner 300b at the joining surface 301 rises, and the split liners 300a and 300b can be welded. On the other hand, in the comparative example, the non-transparent portion 303 exists at the connection end 325. Therefore, the laser beam is blocked by the non-transparent portion 303 and does not reach the joint surface. Therefore, the temperature of the resin that forms the split liner 300b does not rise at the joint surface 301, and it becomes difficult to weld the split liners 300a and 300b. In addition, since the non-transparent part 303 receives a laser beam, temperature rises with the energy. Therefore, in the non-transparent portion 303, the resin dissolves, but since the melting location is not the joining surface 301, it does not contribute to the welding of the divided liners 300a and 300b.

  As described above, according to this embodiment, the mold has the main gate 507 and the valve gate 547 provided in the vicinity of the end of the fourth cavity 314. When the split liner 300 is formed, the resin 700 is injected into the cavity 310 from the main gate 507. Thereafter, the resin 710 is injected from the valve gate 447 into the cavity 310 in the direction opposite to the injection direction of the resin 700 from the main gate 507, and the non-transparent portion 303 generated when the resin 700 is injected from the main gate 507 Push back to 407 side. Therefore, it can suppress that the non-transparent part 303 exists in the connection end part 325 of the division | segmentation liner 300a. As a result, it is possible to suppress the occurrence of poor welding when the divided liners 300a and 300b are welded.

  In this embodiment, the resin 710 is injected from the valve gate 447 when the resin 700 injected from the main gate 407 reaches the connection end portion 315. Therefore, it is possible to associate the resins 700 and 710 with the resin 710 still having high temperature and high fluidity. Therefore, it is possible to suppress the occurrence of welds at the contact portion between the resins 700 and 710. A weld is a boundary that occurs when two fluids are losing fluidity and their tips meet. In this embodiment, since the temperature of the resin 710 is high and the fluidity is large, it is possible to suppress welds.

  In this embodiment, the pressure sensor 510 is used to detect how far the resin 700 is filled. Therefore, it becomes easy to determine when the resin 710 starts to be injected from the valve gate 447. In the present embodiment, the pressure sensor is employed, but other sensors such as a temperature sensor and a contact sensor may be employed.

  In this embodiment, the pressure sensor 510 is used to control the injection timing of the resin 710, but time control may be performed without using the pressure sensor 510. That is, the resin 710 may start to be injected after a certain time from the start of the injection of the resin 700 from the main gate. In this way, the pressure sensor 510 can be omitted.

  The divided liner 300 a formed according to the present embodiment has a non-transparent portion 303 generated when the resin 700 is injected in a portion other than the connection end portion 325. Therefore, since the laser beam reaches the bonding surface 301 when the divided liners 300a and 300b are bonded, it is possible to suppress the occurrence of poor welding.

  The embodiments of the present invention have been described above based on some examples. However, the above-described embodiments of the present invention are for facilitating the understanding of the present invention and limit the present invention. It is not a thing. The present invention can be changed and improved without departing from the spirit and scope of the claims, and it is needless to say that the present invention includes equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... Tank 100 ... Base 101 ... Center axis 110 ... Collar 200 ... Outer cylinder 300 ... Liner 300a, 300b ... Split liner 301 ... Joining surface 302 ... Laser beam irradiation area 303 ... Non-transparent part 305 ... Opening part 310 ... Cavity 311 314 ... cavity portion 312a ... normal line 315 ... connection end portion 321-324 ... part 325 ... connection end portion 400 ... female mold 401 ... concave 405 ... runner 407 ... main gate 410 ... resin injection device 420 ... resin injection device 430 ... Valve device 435 ... Runner 440 ... Needle 445 ... Groove 447 ... Valve gate 450 ... Parting line 500 ... Male mold 501 ... Convex part 507 ... Main gate 510 ... Pressure sensor 547 ... Valve gate 700 ... Resin 705 ... Tip part 710 ... Resin V1 ... Broken line W1 ... Broken line X1 ... Line Y1 ... dotted line Z1 ... dotted line

Claims (8)

An injection molding apparatus for forming a molded body that transmits laser light,
A female mold for forming a cavity for injecting material, a male mold,
A main gate for injecting material into the cavity, provided in either the female mold or the male mold;
A valve gate provided in one of the female mold and the male mold, which is connected to a molded body formed by the cavity at the end of the cavity and another molded body by laser welding. A valve gate connected to the cavity end to form a connection;
With
After injecting material from the main gate into the cavity, the material is injected from the valve gate into the cavity in the direction opposite to the direction of material injection from the main gate. An injection molding apparatus that pushes the non-transparent portion back to the main gate side. The injection molding apparatus according to claim 1,
The timing from the valve gate wood charge to the cavity to initiate injection, injected material from the main gate is when it reaches the cavity end of the valve gate near an injection molding apparatus. The injection molding apparatus according to claim 1 or 2, further comprising:
A sensor for detecting the state of material injection from the main gate into the cavity;
The injection molding apparatus starts injection of material from the valve gate using a signal from the sensor. In the injection molding device according to claim 3,
The sensor is a pressure sensor;
The injection molding apparatus starts injection of a material from the valve gate when a pressure measured by the pressure sensor becomes equal to or higher than a predetermined pressure. The injection molding apparatus according to claim 1,
Timing at which the injection molding apparatus starts injecting wood charge to the cavity from the valve gate is when from the main gate has passed a predetermined time from the start of the injection of material into the cavity, the injection molding apparatus . A method for producing a molded body that transmits laser light,
(1) closing the mold;
(2) injecting material from the main gate into the mold cavity;
(3) From the valve gate connected to the end of the cavity, which forms a connection portion for connecting the formed body formed by the cavity and another formed body by laser welding, to the cavity Injecting a material in a direction opposite to the material injection direction from the main gate to push back a non-transparent portion of the material generated during the material injection from the main gate in the main gate direction;
(4) opening the mold and taking out the molded body;
The manufacturing method of a molded object provided with. A molded body made of a material that transmits laser light,
Having an end connected by laser welding to another molded body;
A molded body, which has a non-transparent portion that does not transmit laser light, which is generated when the molded body is formed, at a position away from the end. In the molded article according to claim 7,
The molded body is a hollow molded body,
A first portion having a cylindrical shape;
A second portion having a ring shape along a conical surface, wherein one end is connected to the first portion, and a normal line in the ring shape is inclined so as to intersect outside the hollow molded body. 2 part,
A third portion having a ring shape in which one end is connected to the other end of the second portion and the outside is formed by a convex curved surface;
A fourth portion having a hollow cylindrical shape with one end connected to the other end of the third portion and forming an outermost sidewall of the hollow molded body;
With
The end is formed at the other end of the fourth portion;
The molded object which has the said non-transparent part in the part except the said edge part of the said 4th part.

Images