JP5765207B2 - Manufacturing method of high-pressure tank - Google Patents

Description

  The present invention relates to a high pressure tank.

  When forming a high-pressure tank, a technique is known in which a joining portion of a liner component member is preheated and then joined by laser welding (Patent Document 1).

JP 2006-283968 A

  However, in the conventional laser welding method, it has been difficult to perform the welding operation so as not to cause welding defects such as insufficient welding and generation of burrs.

  The present invention has been made to solve at least a part of the above-described problems, and an object thereof is to reduce poor welding.

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. According to one form of this invention, the manufacturing method of a high pressure tank including the process of joining two division | segmentation liner structural members using laser welding is provided. The method for manufacturing a high-pressure tank is a method for manufacturing a high-pressure tank including a step of joining two split liner constituent members using laser welding, and the two split liner configurations are formed from an opening of one split liner constituent member. A step of inserting a laser displacement sensor into a central portion of a cross-sectional position including a welded portion that is welded by a laser in a hollow portion of the member; and a step of irradiating the welded portion from the outside of the two liner constituting members; Using the laser displacement sensor, a distance from the laser displacement sensor to an inner surface of at least one of the two divided liner components, and a welding surface of the divided liner, the laser and the distance to the welding surface facing the displacement sensor, by measuring, the two in the weld portion divided La Including gaps between toner components, and a step of laser welding the welding portions while monitoring the welding condition including the occurrence of burrs, a. According to this embodiment, since the two liner constituent members can be welded while monitoring the welding state of the welded portions of the two liner constituent members, it is possible to reduce welding defects such as insufficient welding and occurrence of burrs due to excessive welding. I can do it.

[Application Example 1]
A method of manufacturing a high-pressure tank including a step of joining two divided liner constituent members using laser welding, wherein a laser is formed in the hollow portion of the two divided liner constituent members from an opening of one of the divided liner constituent members. A step of inserting a laser displacement sensor into a central portion of a cross-sectional position including a welded portion to be welded, a step of irradiating the welded portion from the outside of the two liner constituting members, and the laser displacement sensor. And a step of laser welding the welded portion while monitoring the gap between the two divided liner constituting members in the welded portion and the degree of welding including the generation amount of burrs.
According to this application example, since the two liner constituent members can be welded while monitoring the welding state of the welded portions of the two liner constituent members, it is possible to reduce welding defects such as insufficient welding and occurrence of burrs due to excessive welding. I can do it.

  In addition, this invention can be implement | achieved with various forms, for example, can be implement | achieved with forms, such as a laser welding apparatus and a laser welding method other than the manufacturing method of a high pressure tank.

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 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 pressure sensor vicinity (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 division | segmentation liner 300a manufactured. It is explanatory drawing of welding of the division | segmentation liner 300a, 300b. It is explanatory drawing which shows an example of judgment of the welding condition. It is explanatory drawing which shows a transition in welding condition. It is explanatory drawing which shows the flowchart of a welding process. It is explanatory drawing which shows the flowchart when judging the welding condition using the image processing monitor 840. FIG. It is a modification of the flowchart shown in FIG.

  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 on one split liner 300a, and the base 100 may not be provided on 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 with 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 split 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 split 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, it is preferable that the split liner 300a is formed so that the end portion of the outer layer of the split liner 300a is positioned above the flange 110. If it carries out like this, when the division | segmentation liner 300a heat-shrinks, the outer layer of the division | segmentation liner 300a will be applied to the upper side of the collar 110. As a result, since the brim 110 is sandwiched between the inner layer and the outer layer, the bonding between the brim 110 and the split liner 300a is strengthened. Similarly, the split liner 300b having the base 100 is manufactured.

  Next, as shown in FIG. 3D, the split liners 300a and 300b to which the cap 100 is attached are joined. Specifically, the opposite sides of the split liners 300a and 300b to which the cap 100 is attached are aligned. Next, for example, a laser torch is used to irradiate the joint between the two split liners 300a and 300b with a laser torch. As a result, the resin at the joint between the two split liners 300a and 300b is heated to weld the two split liners 300a and 300b. In the case of the present embodiment, one split liner 300a is formed of a laser light transmitting resin, and the other split liner 300b is formed of a laser light non-transmitting resin. Therefore, the split liner 300a is transparent and the split liner 300b is non-transparent to the laser light. 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. Thereby, welding of the division | segmentation liner 300a and the division | segmentation liner 300b becomes easy. Further, in this case, it is preferable that the resin materials of the split liner 300a and the split liner 300b are the same, and a pigment is added to the resin material of one of the split liners 300b so as to provide laser light absorbability. This is because there is no difference in strength between the split liner 300a and the split liner 300b if the material of the split liner 300a and the split liner 300b is the same. In this embodiment, nylon is used as the resin and carbon black is used as the pigment. Note that ferrous oxide (FeO) may be used instead of carbon black.

  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 this 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 a female die of an injection molding apparatus for forming the split liner 300a. The female mold 400 is used as a fixed mold when the split liner 300a is manufactured. FIG. 4A is an explanatory view showing a cross section of the female mold 400. The female mold 400 includes a recess 401, a runner 405, a resin injection device 410, 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 groove 445 is provided at the bottom of the female mold 400. The groove 445 connects the side surface of the recess 401 and the outside of the mold 400.

  FIG. 4B is an explanatory diagram when the female mold 400 shown in FIG. 4A is viewed from above. In FIG. 4B, 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 grooves 445 are provided, but various values can be adopted for this number.

  FIG. 5 is an explanatory view showing a male mold of an injection molding apparatus for forming the split 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 the present embodiment, the resin injection device 410, the runner 405, and the groove 445 are provided in the female mold 400, but may be provided in the male mold 500. Alternatively, the resin injection device 410 and the runner 405 may be provided in the female die 400 and the groove 445 may be provided in the male die 500 in a dispersed manner.

  FIG. 6 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. Note that this inclination preferably coincides with the inclination of the tapered 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”.

  FIG. 7 is an explanatory diagram showing an enlarged view of the vicinity of the pressure sensor in FIG. 6 (portion indicated by a broken line W1). 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. The groove 445 is used as an exhaust path for exhausting air from the cavity when resin is injected into the cavity 310. 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. 8 is an explanatory view showing a state in which resin is started to be injected from the resin injection device 410. FIG. 8A is an explanatory diagram showing an overall view of the mold, and FIG. 8B is an explanatory diagram showing an enlarged vicinity of the tip of the resin 700 (portion surrounded by a broken line X1). The resin injection device 410 injects the resin 700 into the cavity 310 through a path passing from the runner 405 through the main gate 407 (see FIG. 6).

  FIG. 9 is an explanatory diagram showing a state where the tip of the resin has reached the position of the pressure sensor. FIG. 9A is an explanatory view showing an overall view of the mold, and FIG. 9B is an explanatory view showing the vicinity of the tip portion of the resin 700 (the portion surrounded by the broken line Y1) in an enlarged manner. In the state shown in FIG. 9B, 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 resin injection device 410 stops the resin injection.

  FIG. 10 is an explanatory view showing the manufactured divided liner 300a. The split liner 300a may be formed with a burr at a position corresponding to the groove 445. However, since the burr is not yet welded to the split liner 300b, the burr can be easily removed. The split liner 300b can be manufactured in the same procedure. In addition, the shape of the female metal mold | die and male mold | die for manufacturing the division | segmentation liner 300b is united with the shape of the division | segmentation liner 300b. Further, the resin injected into the cavity 310 is different in that it contains a pigment and is a laser light non-transparent resin. For example, carbon black or ferrous oxide (FeO) can be used as the pigment contained.

  FIG. 11 is an explanatory diagram of welding of the split liners 300a and 300b. The laser irradiator 800 is disposed outside the radial direction of the welded portions of the split liners 300a and 300b. Further, the laser displacement sensor 810 is disposed inside the split liners 300a and 300b. The laser displacement sensor 810 is located at the center of the cross section 830 of the welded portion of the split liners 300a and 300b. The laser displacement sensor 810 is attached to a support bar 820 inserted from the base 100. Note that the laser displacement sensor 810 can be moved along the support rod 820. An image processing monitor 840 is disposed outside the welded portions of the split liners 300a and 300b. A stepping motor 850 for rotating the split liners 300a and 300b is disposed on the right side of the split liner 300a. The split liners 300a and 300b are held by a split liner support portion 855 and connected to a stepping motor 850. The split liner support portion 855 may be formed of a transparent member so as to transmit laser light. The operations of the laser irradiator 800 and the stepping motor 850 are controlled by the control unit 860 based on a signal from the laser displacement sensor 810 or the image processing monitor 840.

  FIG. 12 is an explanatory diagram illustrating an example of determination of the degree of welding. The laser displacement sensor 810 scans the welding range and measures the distance from the laser displacement sensor 810 to the welding surface 301b of the split liner 300b or the welding surface 301a of the split liner 300a. When a gap exists between the welding surface 301b of the split liner 300b and the welding surface 301a of the split liner 300a, the scanning position of the laser displacement sensor 810 is switched from the welding surface 301b of the split liner 300b to the welding surface 301a of the split liner 300a. Since the measurement distance changes suddenly at the position, a peak occurs in the signal. Therefore, it can be determined that welding is insufficient while this peak is present. This peak is referred to as “welding insufficient peak signal S1”. When the divided liner 300a and the divided liner 300b are welded, the interval W between the welded surface 301a and the welded surface 301b gradually approaches zero, so that the welding shortage peak signal S1 becomes almost zero. That is, it is possible to determine the degree of welding between the divided liner 300a and the divided liner 300b by monitoring the welding shortage peak signal S1.

  In addition, when a burr | flash generate | occur | produces by excessive welding, an unevenness | corrugation will arise in a welding part and the distance of the division | segmentation liner 300b and the laser displacement sensor 810 will become short. At this time, an excessive welding peak signal S2 is generated in the opposite direction to the insufficient welding peak signal S1. Therefore, it is possible to easily determine whether or not the excessive deposition peak signal S2 has been detected by monitoring the excessive deposition peak signal S2.

  The image processing monitor 840 photographs the welded portion from the outside and monitors the number or area of the black spots 710 generated when the divided liners 300a and 300b are welded. As welding of the divided liners 300a and 300b proceeds, the number of black spots 710 increases and the total area of the black spots 710 increases. Therefore, by monitoring the number or area of the black spots 710, it is possible to determine the degree of welding between the divided liner 300a and the divided liner 300b. In addition, since the division | segmentation liner 300a located outside in a welding part is transparent, the number and area of the black spot 710 can be monitored easily.

  FIG. 13 is an explanatory diagram showing a transition in the welding condition. FIG. 13A shows a state of insufficient welding. In this state, since the interval W between the welding surface 301a and the welding surface 301b is not zero, an insufficient welding peak signal S1 is generated. Further, the number of black spots 710 is small and the area is small. FIG. 13B shows a good welded state. In this state, since the interval W between the welding surface 301a and the welding surface 301b is substantially zero, the welding insufficient peak signal S1 is substantially zero. Also, the number of black spots 710 is small and the area is large. FIG. 13C shows the state of excessive welding as a reference. In this state, burrs are formed on the inner side of the weld between the split liner 300a and the split liner 300b, and the black spots 710 are generated in almost the entire area of the weld. Actually, by monitoring the insufficient welding peak signal, or by monitoring the number of black spots 710 or the total area of the black spots 710, the degree of welding is judged, so that the excessive welding state shown in FIG. To control.

  FIG. 14 is an explanatory diagram showing a flowchart of the welding process. In step S <b> 100, the control unit 860 starts irradiation with laser light using the laser irradiator 800. Since the split liner 300b is opaque, when the laser beam energy is received, the resin melts and is welded to the split liner 300a. In step S110, the control unit 860 determines the degree of welding using the welding deficiency peak signal S1 from the laser displacement sensor 810. When the welding shortage peak signal S1 is equal to or less than a predetermined threshold value, the control unit 860 determines that the welding is good, and the process proceeds to step S130. If the welding deficiency peak signal S1 is larger than a predetermined threshold value and it is determined that welding is insufficient, the control unit 860 proceeds to step S120 to continue the laser beam irradiation, and then performs the processing again in step S110. Shift to step and judge the welding condition.

  In step S130, the control unit 860 uses the stepping motor 850 to rotate the divided liners 300a and 300b. In step S140, control unit 860 determines whether or not a new laser irradiation point has already been welded. This determination is the same as the determination in step S110. If welding has already been performed at a new laser irradiation point, it can be determined that the welding by the laser beam has been completed over the entire circumference of the split liners 300a and 300b. Therefore, the control unit 860 shifts the process to step S150 and ends the laser light irradiation. On the other hand, in the case where welding is not performed at a new laser irradiation point, the control unit 860 proceeds to step S120. In the determination in step S110, the presence or absence of burrs may be determined based on the distance between the divided liner 300b and the laser displacement sensor 810, and the degree of welding may be determined.

  As described above, according to this embodiment, the laser displacement sensor 810 is used to determine the degree of welding by the laser beam, and the divided liners 300a and 300b are welded. Therefore, insufficient welding and excessive welding are suppressed, resulting in poor welding. Can be reduced.

  FIG. 15 is an explanatory diagram showing a flowchart for determining the degree of welding using the image processing monitor 840. In step S <b> 200, the control unit 860 starts irradiation with laser light using the laser irradiator 800. Step S200 is the same as step S100 described in FIG. In step S210, the control unit 860 uses the monitor image of the image processing monitor 840 to count the number of black spots 710 or calculate the total area of the black spots 710. When these values are equal to or greater than a predetermined threshold value, the control unit 860 determines that the welding is good, and the process proceeds to step S230. If the number of black spots 710 or the total area of the black spots 710 has not reached a predetermined threshold value, the control unit 860 determines that welding is insufficient, moves the process to step S220, and performs laser beam irradiation. Then, the process proceeds to step S210 again to determine the welding condition.

  In step S230, the control unit 860 rotates the split liners 300a and 300b using the stepping motor 850. In step S240, control unit 860 determines whether or not a new laser irradiation point has already been welded. This determination is the same as the determination in step S210. The subsequent flow is the same as that described with reference to FIG.

  As described above, according to the present embodiment, the image processing monitor 840 is used to determine the degree of welding by the laser beam, and the divided liners 300a and 300b are welded. Therefore, insufficient welding and excessive welding are suppressed, and defective welding is prevented. Can be reduced. Note that both the laser displacement sensor 810 and the image processing monitor 840 may be used in combination, or only one of them may be used.

  FIG. 16 is a modification of the flowchart shown in FIG. In this flowchart, step S115 is executed between steps S110 and S120 in the flowchart shown in FIG. 14, and step S125 is provided between steps S110 and S130. Step S115 increases the intensity of the laser beam when the welding condition by the laser beam is insufficient. Thereby, welding is promoted. Step S125 lowers the intensity of the laser beam so that the welding does not become excessive when the welding condition by the laser beam becomes good. Thus, if the intensity | strength of a laser beam is changed, the division | segmentation liner 300a and 300b can be welded in a short time. Similarly, in the flowchart shown in FIG. 15, it is possible to change the intensity of the laser beam.

    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 301a, 301b ... Welding surface 305 ... Opening part 310 ... Cavity 311-314 ... 1st-4th cavity Part 312a ... Normal 315 ... Connection end part 400 ... Female mold 401 ... Recess 405 ... Runner 407 ... Main gate 410 ... Resin injection device 445 ... Groove 447 ... Valve gate 450 ... Parting line 500 ... Male mold 501 ... Convex part 510 ... Pressure sensor 700 ... Resin 705 ... Tip part 710 ... Black spot 800 ... Laser irradiator 810 ... Laser displacement sensor 820 ... Support rod 830 ... Cross section 840 ... Image processing monitor 850 ... Stepping motor 855 ... Split liner support part 860 ... Control unit W ... interval W1 Dashed X1 ... dashed Y1 ... dashed S1 ... welding lack peak signal S2 ... welding excessive peak signal

Claims (1)

A method for manufacturing a high-pressure tank including a step of joining two split liner components using laser welding,
Inserting a laser displacement sensor into the center of the cross-sectional position including the welded portion that is welded by laser in the hollow portion of the two divided liner constituting members from the opening of one divided liner constituting member;
Irradiating the laser to the welded portion from the outside of the two liner constituting members;
Using the laser displacement sensor, a distance from the laser displacement sensor to an inner surface of at least one of the two divided liner components, and a welding surface of the divided liner, the laser displacement and the distance to the welding surface facing the sensor, by measuring the gap between the two split liner constituting member in the weld portion, and laser welding the welding portions while monitoring the welding condition including the occurrence of burrs And a process of
A method for manufacturing a high-pressure tank.

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