JP5831437B2 - High pressure tank inspection method and inspection apparatus - Google Patents

Description

  The present invention relates to a high-pressure tank.

  2. Description of the Related Art Conventionally, a high-pressure tank manufactured by a filament winding method (hereinafter also referred to as “FW method”) is known as a pressure vessel for storing a high-pressure fluid such as high-pressure hydrogen. In the FW method, a reinforcing fiber impregnated with a thermosetting resin such as an epoxy resin is wound around the outer periphery of a tank container (hereinafter also referred to as “liner”) formed of a resin member or the like. And the thermosetting resin of the reinforced fiber is thermosetted to form a reinforcing layer of fiber reinforced resin (hereinafter also referred to as “fiber reinforced resin layer”).

  By the way, when a high-pressure tank is manufactured by the FW method, it is known that a void may be formed between the liner and the fiber reinforced resin layer due to thermal shrinkage of the liner after the thermosetting treatment. Yes. Such voids cause various problems such as a decrease in strength of the high-pressure tank. Patent Document 1 discloses a technique of providing a through hole that penetrates a reinforcing layer in order to suppress high-pressure gas that has permeated through a liner from staying in the gap. Patent Document 2 discloses a technique for filling a gap between the liner and the reinforcing layer by injecting a resin material into the gap.

JP 2008-261414 A Japanese Patent Laid-Open No. 10-231998

  However, although the technique of Patent Document 1 can release the high-pressure gas remaining in the gap between the liner and the fiber reinforced resin layer, the gap itself cannot be lost. On the contrary, the strength of the fiber reinforced resin layer may be reduced by the through-hole provided in the fiber reinforced resin layer. In the technique of Patent Document 2, the resin member cannot be spread over the entire gap, and the gap remains in a dispersive manner, and there is a possibility that the strength reduction of the high-pressure tank cannot be suppressed. If the gap is too large, the resin member may not be able to compensate for the strength reduction caused by the gap. Furthermore, in the technique of Patent Document 2, since a tool and a process for injecting the reinforcing resin member of the high-pressure tank are added, the manufacturing cost of the high-pressure tank may increase.

  Here, when the high-pressure gas tank is used, it is desirable that the gap between the liner and the fiber reinforced resin layer is eliminated or reduced. Moreover, it is desirable that a high-pressure gas tank with a significant gap is detected as a defective product. Therefore, in the inspection of the high-pressure tank after the fiber reinforced resin layer is formed, it is desirable that the size of the gap can be easily and accurately grasped. However, until now, in the inspection of the high-pressure tank, sufficient contrivance has not been made for the inspection of the gap generated between the liner and the reinforcing layer.

  Furthermore, the inventor of the present invention has found that the gap between the liner and the fiber reinforced resin layer may reduce the test accuracy of the pressure test of the high-pressure tank. Conventionally, in order to verify the pressure resistance of a high-pressure tank, changes in the expansion amount of the high-pressure tank with respect to changes in the internal pressure of the high-pressure tank have been measured. As a measuring method of the change in the expansion amount of the high-pressure tank, a water tank type measuring method is known. In the water tank type measuring method, the high-pressure tank is housed in a sealed container filled with pure water. Then, a fluid is supplied to the inside of the high-pressure tank to increase the internal pressure, and the amount of pure water pushed out from the sealed container by the expansion accompanying the change in the internal pressure of the high-pressure tank is measured as the expansion amount of the high-pressure tank.

  However, for the high-pressure tank having a fiber reinforced resin layer, when the amount of expansion is measured by the above water tank type measurement method, in the sealed container, pure water enters the gap between the liner and the fiber reinforced resin layer, Air from the gap may leak. Then, the amount of pure water pushed out from the sealed container fluctuates due to the influence of pure water that has entered the gap and air leaked from the gap, causing an error in the measurement result of the expansion amount of the high-pressure tank. It will be. Until now, in the measurement of the expansion amount of the high-pressure tank, sufficient contrivance has not been made to reduce the influence of the gap between the liner and the thermosetting resin.

  As described above, conventionally, sufficient contrivance has not been made for the inspection method of the high-pressure gas tank in consideration of the gap between the liner and the fiber reinforced resin layer. In addition, for inspection of high-pressure tanks, cost reduction, resource saving, easy inspection process, improved usability of inspection equipment, etc. were desired. Has not been devised.

  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.

[1] According to one aspect of the present invention, there is provided a method for inspecting a high-pressure tank comprising a hollow tank container and a reinforcing layer formed on the outer surface of the tank container. In this inspection method, (a) changing the internal pressure of the tank container, obtaining a relationship representing a change in the expansion amount of the tank container with respect to a change in the internal pressure of the tank container, and (b) the step (a) A linear region in which the amount of expansion of the tank container changes linearly with respect to the internal pressure of the tank container in the relationship acquired in step (b), and a value related to the strength of the high-pressure tank is determined based on the linear relationship in the linear region. Acquiring. According to the inspection method of this aspect, it is possible to easily and highly accurately inspect the gap between the tank container and the reinforcing layer and the strength of the high-pressure tank in which the influence of the gap is suppressed.

[2] In the inspection method of the above aspect, in the step (a), the filling amount of the fluid in the tank container is increased to increase the internal pressure of the tank container, and the internal pressure of the tank container and the filling amount of the fluid are increased. May be obtained as a relationship representing a change in the expansion amount of the tank container with respect to a change in the internal pressure of the tank container; the step (b) may include (b1) the internal pressure of the tank container Detecting a linear region in which the fluid filling amount changes linearly with respect to the internal pressure of the tank container in relation to the fluid filling amount; and (b2) filling the fluid at the beginning of the linear region. Obtaining a quantity as a value when a gap between the tank container and the reinforcing layer disappears; and (b3) a preliminarily prepared amount between the volume of the gap and the filling amount of the fluid. Correspondence Based on, it may be a process including a step of acquiring the void volume for the loading of the value of the fluid obtained in the step (b2) as the value related to the intensity of the high-pressure tank. According to the inspection method of this aspect, the volume of the gap between the tank container and the reinforcing layer in the high-pressure tank can be acquired easily and with high accuracy based on the fluid filling amount.

[3] The inspection method according to the above aspect may further include a step (c1) of outputting a pass / fail result of the high-pressure tank based on the volume of the gap acquired in the step (b3). According to the inspection method of this aspect, the quality result of the high-pressure tank is appropriately output based on the volume of the gap between the tank container and the reinforcing layer. Therefore, for example, a high-pressure tank whose strength is significantly reduced due to the gap can be extracted as a defective product.

[4] In the inspection method of the above aspect, the step (a) includes: (a1) increasing the filling amount of the fluid in the tank container so that the internal pressure of the tank container is changed from the first pressure to the second pressure. Increasing a first relationship representing an increase change in the expansion amount of the tank container relative to a pressure increase change in the internal pressure of the tank container; and (a2) decreasing the filling amount of the fluid in the tank container; Reducing the internal pressure of the tank container from the second pressure to the first pressure, and obtaining a second relationship representing a decrease change in the expansion amount of the tank container with respect to a decrease in the internal pressure of the tank container; In the step (b), the expansion amount of the tank container is linear with respect to the internal pressure of the tank container in each of the first relationship and the second relationship. The first linear region and the second linear region to be detected are detected, and the difference between the first linear relationship and the second linear relationship, which is a linear relationship in each of the first linear region and the second linear region, is detected. The step of acquiring a value relating to the strength of the reinforcing layer may be based on the above. According to the inspection method of this embodiment, since the relation between the internal pressure of the tank container and the expansion amount of the tank container at the time of increasing the internal pressure of the tank container and the high pressure is used, the inspection on the strength of the high-pressure tank can be performed with higher accuracy. Can be done.

[5] In the inspection method of the above aspect, the step (b) extrapolates each of the first linear relationship and the second linear relationship to the first pressure, and The expansion amount of 1 and the second expansion amount are acquired, and the residual expansion amount of the reinforcing layer that is the difference between the first expansion amount and the second expansion amount is acquired as a value related to the strength of the reinforcing layer. It may be a process including a process. According to the inspection method of this embodiment, the residual expansion amount (permanent expansion amount) that is a measure of the strength of the reinforcing layer can be easily obtained. Therefore, the strength of the high-pressure tank can be easily verified with high accuracy.

[6] In the inspection method of the above aspect, in the step (b), the expansion amount of the tank container with respect to the second pressure in the first relationship or the second relationship is further determined as the maximum expansion of the reinforcing layer. It may be a step including a step of obtaining as a quantity and obtaining a permanent increase rate of the reinforcing layer based on the maximum expansion amount and the residual expansion amount. According to the inspection method of this embodiment, it is possible to easily obtain the permanent increase rate that is a measure of the strength of the reinforcing layer.

[7] The inspection method according to the above aspect may further include a step (c2) of outputting a result of the quality of the high-pressure tank based on the permanent increase rate. If it is the inspection method of this form, the quality determination of a high-pressure tank can be accurately performed based on a permanent increase rate.

[8] In the inspection method of the above embodiment, the step (b), in the step of determining the expansion rate of change of the tank container against the inner pressure of the tank vessel in the linear region as a value related to the intensity of the high-pressure tank There may be. If the inspection method of this embodiment, since it is possible to obtain an expansion rate of change of the reinforcement layer against the inner pressure in the tank container as a measure of the strength of the reinforcing layer, performing the inspection of the intensity of the high-pressure tank easily and accurately Can do.

[9] The inspection method according to the above aspect may further include (c3) a step of outputting a result of pass / fail of the high-pressure tank based on the rate of change. If it is the inspection method of this form, the quality determination of a high-pressure tank can be performed easily and with high precision.

[10] In the inspection method of the above aspect, the step (a) may be a step of acquiring a change in volume of the high-pressure tank as a change in expansion amount of the tank container using an optical sensor. If it is the inspection method of this form, the change of the expansion amount of the tank container after the space | gap between a tank container and a reinforcement layer lose | disappears can be easily measured based on the volume change of a high-pressure tank.

[11] In the inspection method of the above aspect, the tank container may be formed of a resin member; the reinforcing layer is a fiber reinforced resin formed by winding a fiber reinforced resin around the tank container and thermosetting the resin. It may be a layer. If this type of inspection method,

[12] According to another aspect of the present invention, there is provided a high-pressure tank inspection apparatus comprising a hollow tank container and a reinforcing layer formed on the outer surface of the tank container. This inspection apparatus changes an internal pressure of the tank container by changing a filling amount of the fluid in the tank container, and obtains a relationship representing a change in the expansion amount of the tank container with respect to a change in the internal pressure of the tank container. A linear region in which the expansion amount of the tank container changes linearly with respect to the internal pressure of the tank container in the relationship acquired by the expansion test unit, and based on the linear relationship in the linear region, A strength verification unit that acquires a value related to the strength of the high-pressure tank. According to the inspection apparatus of this aspect, it is possible to easily and highly accurately inspect the gap between the tank container and the reinforcing layer and the high-pressure tank in which the influence of the gap is suppressed.

  The present invention can also be realized in various forms other than the inspection method. For example, a method for measuring the volume of a gap between a tank container and a reinforcing layer in a high-pressure tank, an inspection device for a high-pressure tank capable of detecting the volume of the gap, a control method for the inspection device, and a computer program for realizing the control method The present invention can be realized in the form of a non-temporary recording medium that records the computer program.

Schematic which shows the structure of the inspection apparatus of a high pressure tank. The schematic sectional drawing which shows the structure of a high pressure tank. Explanatory drawing which shows the process sequence of the inspection process which an inspection apparatus performs. Explanatory drawing for demonstrating the relationship between the internal pressure of a high-pressure tank after the arrival of an initial filling state, and the filling amount of pure water. Explanatory drawing for demonstrating the relationship between the space | gap disappearance filling amount and the volume of the space | gap of a high pressure tank. Schematic which shows the structure of the inspection apparatus of the high pressure tank in 2nd Embodiment. Explanatory drawing which shows the process sequence of the inspection process of the high pressure tank performed in the inspection apparatus of 2nd Embodiment. Explanatory drawing which shows an example of the graph showing the 1st and 2nd relationship. Explanatory drawing for demonstrating the acquisition process of the permanent increase rate of a fiber reinforced resin layer. Explanatory drawing for demonstrating the expansion | swelling change of a fiber reinforced resin layer. Explanatory drawing which shows the process sequence of the inspection process of the high pressure tank as 3rd Embodiment. Explanatory drawing for demonstrating the intensity | strength determination of the high pressure tank in 3rd Embodiment. Schematic which shows the structure of the inspection apparatus of the high pressure tank in 4th Embodiment.

A. First embodiment:

  FIG. 1 is a schematic diagram showing a configuration of a high-pressure tank inspection apparatus 100 according to an embodiment of the present invention. The inspection apparatus 100 fills the high-pressure tank 10 with pure water to increase the internal pressure of the high-pressure tank 10, and based on the relationship between the internal pressure and the amount of pure water charged, a gap (which causes deterioration of the high-pressure tank 10 ( The inspection for details will be described later. The inspection apparatus 100 includes a pure water tank 20, a weight scale 30, a pump 40, a pressure detector 50, a pipe 60, and a control unit 110.

  The high-pressure tank 10 to be inspected is attached to the inspection apparatus 100 by connecting a pipe 60 to the valve 15. The pure water tank 20 is a water storage tank that stores pure water filled in the high-pressure tank 10. The pure water tank 20 is connected to the high-pressure tank 10 through a pipe 60. The weigh scale 30 measures the weight of the pure water tank 20 containing pure water and outputs it to the control unit 110. The pump 40 is provided in the pipe 60 and allows pure water to flow from the pure water tank 20 into the high-pressure tank 10 in response to a command from the control unit 110. The pressure detector 50 detects the pressure in the pipe 60 between the high-pressure tank 10 and the pump 40 and outputs it to the control unit 110.

  The control unit 110 is configured by a microcomputer including a central processing unit (CPU) and a main storage device, and controls each component of the inspection device 100 to inspect the high-pressure tank 10 (described later). ). The control unit 110 includes a filling control unit 111, a measurement unit 112, a recording unit 113, a volume acquisition unit 114, and a determination unit 115 as functional units for executing an inspection process described later.

  The filling control unit 111 controls the supply of pure water to the high-pressure tank 10 by controlling the driving of the pump 40. The measuring unit 112 refers to the decrease in the weight of pure water in the pure water tank 20 based on the detection value of the weigh scale 30 (hereinafter referred to as “pure water filling amount”) filled in the high-pressure tank 10. .) Get as. In addition, the measurement unit 112 acquires the detection value of the pressure detector 50 as the internal pressure of the high-pressure tank 10.

  The recording unit 113 records the filling amount and the internal pressure of pure water in the high-pressure tank 10 acquired by the measuring unit 112 by storing them in a storage unit (not shown). The volume acquisition unit 114 acquires the volume of the gap in the high-pressure tank 10 and the lower limit value of the internal pressure when the high-pressure tank 10 is used based on the record of the filling amount of pure water in the high-pressure tank 10 and the detected value of the internal pressure. Details of these acquisition methods will be described later. The determination unit 115 determines the quality of the high-pressure tank 10 based on the acquired volume of the gap 16.

  FIG. 2 is a schematic cross-sectional view illustrating a configuration of the high-pressure tank 10 that is an inspection target of the inspection apparatus 100. In FIG. 2, the central axis OL of the high-pressure tank 10 is shown by a one-dot chain line. The high-pressure tank 10 is mounted on, for example, a fuel cell vehicle and stores high-pressure hydrogen supplied as fuel gas to the fuel cell. The high-pressure tank 10 includes a liner 11, a fiber reinforced resin layer 12, a valve side base 13, an end side base 14, and a valve 15.

  The liner 11 is a tank container that constitutes the main body of the high-pressure tank 10 and has an accommodation space SP for accommodating high-pressure hydrogen therein. The liner 11 has a substantially cylindrical cylinder part and substantially hemispherical dome parts at both ends thereof. In addition, the opening part to which the nozzle | cap | die parts 13 and 14 are attached is formed in the top part of two dome parts. For example, the liner 11 is formed by a rotational molding method using a resin member such as reinforced plastic. The liner 11 may be made of a light metal such as aluminum instead of the resin member. Further, the liner 11 may be formed by a manufacturing method in which a plurality of divided members are bonded and integrated, instead of an integrated molding manufacturing method such as a rotational molding method.

The fiber reinforced resin layer 12 is a reinforcing layer that covers the outer surface of the liner 11. The fiber reinforced resin layer 12 is composed of a reinforced fiber such as carbon-fiber-reinforced plastic (CFRP) wound around the outer surface of the liner 11 and a thermosetting resin that binds the reinforced fibers. Composed. The fiber reinforced resin layer 12 is formed as follows.
(1) The reinforcing fiber impregnated with the thermosetting resin is wound around the liner 11 by a predetermined winding method such as so-called helical winding or hoop winding.
(2) The liner 11 around which the reinforcing fibers are wound is heated in a thermostatic bath at a high temperature of, for example, about 85 ° C. to thermoset the thermosetting resin in the reinforcing fibers.

  The valve-side base 13 is a connection part for attaching the valve 15, and is fixedly attached to one dome part of the high-pressure tank 10. The valve-side base 13 has a substantially cylindrical main body portion and a flange portion that is fitted between the liner 11 and the fiber reinforced resin layer 12. The opening of the valve side cap 13 is connected to the accommodation space SP of the liner 11, and an internal thread portion that engages with the external thread portion of the valve 15 is formed on the inner peripheral surface thereof. The valve side cap 13 may be formed of a metal member such as stainless steel or aluminum, or may be formed of a resin member such as reinforced plastic. The valve 15 is attached to the valve side cap 13 after the fiber reinforced resin layer 12 is formed on the liner 11.

  The end side cap 14 is a sealing member that seals the opening of the liner 11, and is fixedly attached to the dome portion of the high-pressure tank 10 on the side opposite to the valve side cap 13. . The end-side base 14 has a substantially cylindrical main body portion that fits airtightly into the opening portion of the liner 11, and a flange portion that is fitted between the liner 11 and the fiber reinforced resin layer 12. The end side cap 14 may be formed of a metal member such as stainless steel or aluminum, or may be formed of a resin member such as reinforced plastic. The end side cap 14 has an end portion exposed from the fiber reinforced resin layer 12 to the outside. As a result, the end-side cap 14 functions as a heat radiating portion that guides the heat in the accommodation space SP to the outside.

  By the way, in the manufacturing process of the high-pressure tank 10, the gap 16 may be formed between the liner 11 and the fiber reinforced resin layer 12 after the fiber reinforced resin layer 12 is formed. The void 16 is generated due to the difference between the heat shrinkage amount of the liner 11 after the thermosetting treatment for forming the fiber reinforced resin layer 12 and the heat shrinkage amount of the fiber reinforced resin layer 12. Specifically, it is as follows.

  In the thermosetting treatment, the temperature of the liner 11 is increased by heating in a thermostatic bath and heat generated by the curing reaction of the epoxy resin impregnated in the reinforcing fibers. Usually, the liner 11 is made of a material having a large thermal expansion coefficient, and is likely to cause thermal expansion and contraction. The thermal expansion of the liner 11 is limited by the reinforcing fibers wound around the outer surface during the thermosetting process, but after the thermosetting process, the liner 11 thermally contracts as the temperature decreases. Therefore, a gap 16 in which air is confined is formed between the liner 11 and the fiber reinforced resin layer 12 after the thermosetting treatment.

  If the high-pressure tank 10 is used with a remarkably large gap 16, the liner 11 is greatly distorted, and the liner 11 may be damaged or cracked in a low temperature environment. Therefore, when the high-pressure tank 10 is used, it is desirable that the gap 16 is lost or reduced. Further, at the time of manufacturing the high-pressure tank 10, it is desirable that the high-pressure tank 10 having a remarkably large gap 16 be extracted before shipping as a manufacturing defect.

  Here, the gap 16 of the high-pressure tank 10 can be eliminated or reduced by applying an internal pressure to the liner 11 of the high-pressure tank 10 to expand and deform the liner 11. Therefore, when the high-pressure tank 10 is used, the internal pressure of the high-pressure tank 10 that can eliminate or reduce the gap 16 is defined as the lower limit value, and the internal pressure of the high-pressure tank 10 is controlled so as not to fall below the lower limit value. Is desirable. Therefore, in the inspection before using the high-pressure tank 10, it is desirable that the lower limit value of the internal pressure of the high-pressure tank 10 can be accurately grasped.

  By the way, the size of the gap 16 of the high-pressure tank 10 can be roughly confirmed visually by an image of an X-ray CT scanner. However, in the X-ray CT scanner image, it is not easy to accurately measure the void volume. Further, as a method of measuring the lower limit value of the internal pressure of the high-pressure tank 10 that can eliminate or reduce the gap 16 using an X-ray CT scanner, for example, the state of the gap 16 is confirmed by an image of the X-ray CT scanner. There is a method in which the internal pressure of the high-pressure tank 10 is changed. However, this method is very time-consuming, and it is difficult to measure the appropriate lower limit value of the internal pressure for each high-pressure tank 10 for all the high-pressure tanks 10.

  Therefore, in the inspection apparatus 100 (FIG. 1) of the present embodiment, the size (volume) of the gap 16 of the high-pressure tank 10 and an appropriate lower limit value of the internal pressure of the high-pressure tank 10 are acquired in the inspection process described below. To do. Further, the quality of the high-pressure tank 10 is inspected based on the detection result of the volume of the gap 16. Specifically, it is as follows.

  FIG. 3 is a flowchart illustrating the processing procedure of the inspection process executed by the inspection apparatus 100. In step S10, the filling control unit 111 drives the pump 40 to supply until the accommodation space SP of the high-pressure tank 10 is filled with pure water. Hereinafter, a state in which the accommodation space SP of the high-pressure tank 10 is filled with pure water without applying pressure by the pump 40 is referred to as an “initial filling state”. After the high pressure tank 10 reaches the initial filling state, the filling control unit 111 further continues the supply of pure water to the pump 40 to increase the internal pressure of the high pressure tank 10.

  In step S <b> 20, the recording unit 113 acquires the weight of pure water filled in the high pressure tank 10 and the measured value of the internal pressure of the high pressure tank 10 from the measurement unit 112 and records them. In step S <b> 30, the volume acquisition unit 114 acquires a relationship representing a change in the pure water filling amount with respect to a change in the internal pressure of the high-pressure tank 10 based on the measurement value recorded by the recording unit 113. In this relationship, a predetermined change indicating that the gap 16 has disappeared due to the expansion of the liner 11 is detected.

  FIG. 4 is an explanatory diagram for explaining the relationship between the internal pressure of the high-pressure tank 10 and the pure water filling amount after reaching the initial filling state. FIG. 4 is a graph showing the relationship between the internal pressure of the high-pressure tank 10 and the amount of pure water charged after reaching the initial filling state, where the horizontal axis is the internal pressure of the high-pressure tank 10 and the vertical axis is the pure water in the high-pressure tank 10. It is shown as the filling amount. This graph is obtained by the experiment of the inventors of the present invention. In this graph, the origin is the pressure of the high-pressure gas and the amount of pure water charged when the initial filling state is reached.

  When the inventor of the present invention continues to supply pure water to the high-pressure tank 10 after reaching the initial filling state, the filling amount of pure water changes as follows with respect to the change in the internal pressure of the high-pressure tank 10. I found it. The filling amount of pure water first increases so as to draw a convex curve with respect to the internal pressure of the high-pressure tank 10. When the internal pressure reaches a certain pressure P1, it linearly increases at a certain rate of change with respect to the internal pressure of the high-pressure tank 10. The reason why the pure water filling amount changes in this way with respect to the internal pressure of the high-pressure tank 10 is presumed as follows.

  Immediately after reaching the initial filling state, the liner 11 expands while receiving the reaction force generated by the air in the gap 16 as the internal pressure of the high-pressure tank 10 increases. Then, after the outer surface of the liner 11 reaches the inner surface of the fiber reinforced resin layer 12 and the gap 16 is almost disappeared, the liner 11 and the fiber reinforced resin layer 12 are integrally expanded and deformed. To start.

  Here, in the period in which the gap 16 exists, the reaction force due to the air acting on the liner 11 increases as the gap 16 is reduced. Therefore, during the period, the filling amount of pure water corresponding to the expansion amount of the liner 11 changes in a curve with respect to the internal pressure of the high-pressure tank 10. Then, after the gap 16 has almost disappeared, the liner 11 expands together with the fiber reinforced resin layer 12 while receiving resistance from the fiber reinforced resin layer 12. Therefore, during that period, the filling amount of pure water corresponding to the expansion amount of the liner 11 changes linearly (linearly) with respect to the internal pressure of the high-pressure tank 10.

  From the above inference, the pressure P1 when the change in the filling amount of the pure water with respect to the internal pressure of the high-pressure tank 10 changes from a curvilinear change to a linear change is such that the gap 16 has almost disappeared in the high-pressure tank 10. It is thought that it is the pressure when becoming. Therefore, in the inspection apparatus 100 of the present embodiment, the volume acquisition unit 114 is based on the measurement value recorded by the recording unit 113, and the changing point where the tendency of the change in the amount of pure water with respect to the internal pressure of the high-pressure tank 10 changes. The pressure P1 which is is acquired. Specifically, the volume acquisition unit 114 detects the change point as follows, for example.

  The volume acquisition unit 114 uses the measurement value data recorded by the recording unit 113 to calculate the rate of change of the pure water filling amount with respect to the internal pressure of the high-pressure tank 10 for each minute section. The volume acquisition unit 114 changes the amount of pure water charged with respect to the internal pressure of the high-pressure tank 10 when the rate of change for each minute section converges to a fluctuation range within a substantially constant range in a predetermined section. It is determined that the trend of is linear. And the internal pressure when the said change rate is acquired initially is acquired as pressure P1. The pressure P1 is an appropriate lower limit value of the internal pressure of the high-pressure tank 10 at which the gap 16 of the high-pressure tank 10 is almost lost.

  The filling control unit 111 continues to supply pure water to the high-pressure tank 10 and increases the internal pressure of the high-pressure tank 10 until the pressure P1 is detected by the volume acquisition unit 114 (“NO” in step S30 of FIG. 3). Arrow). And when the pressure P1 is detected by the volume acquisition part 114, the drive of the pump 40 is stopped and supply of the pure water with respect to the high pressure tank 10 is stopped (step S40).

  In step S50, the volume acquisition unit 114 uses the pure water when the internal pressure of the high-pressure tank 10 reaches the pressure P1 from the relationship between the internal pressure of the high-pressure tank 10 and the filling amount of pure water used in step S30 (FIG. 4). The filling amount W1 is acquired. The pure water filling amount W1 is a pure water filling amount capable of almost eliminating the gap 16 in the high-pressure tank 10. Hereinafter, this pure water filling amount W1 is also referred to as “void gap filling amount W1”. The volume acquisition unit 114 further acquires the volume of the gap 16 as described below based on the gap disappearance filling amount W1.

  FIG. 5 is an explanatory diagram for explaining the relationship between the gap disappearance filling amount W1 and the volume of the gap 16 of the high-pressure tank 10. FIG. 5 is a graph showing the relationship between the gap disappearance filling amount W1 and the volume of the gap 16 in the high-pressure tank 10, with the horizontal axis representing the void disappearance filling amount and the vertical axis representing the volume of the gap 16 in the high-pressure tank 10. is there. This graph is obtained by the experiment of the inventor of the present invention.

  The inventor of the present invention measured the void disappearance filling amount W1 and the volume of pure water of the void disappearance filling amount W1 for a plurality of high pressure tanks 10 (hereinafter also referred to as “tank A”) of the same type. Here, the volume of pure water relative to the gap disappearance filling amount W1 corresponds to the expansion volume of the liner 11 that can eliminate the gap 16, that is, the volume of the gap 16.

  The inventor of the present invention has found from the measurement results that there is a linear relationship between the gap disappearance filling amount W1 and the volume of the gap 16 as represented by the graph Ga. If the relationship between the gap disappearance filling amount W1 and the volume of the gap 16 is acquired in advance, the volume of the gap 16 in the high-pressure tank 10 is measured with respect to the measured value of the gap disappearance filling amount W1. Found that you can get.

  In the inspection apparatus 100 of the present embodiment, a map in which a relationship between the gap disappearance filling amount W1 and the volume of the gap 16 for the high-pressure tank 10 is set is stored in advance in a storage unit (not shown). The volume acquisition unit 114 refers to the map and acquires the volume V1 of the gap 16 with respect to the gap disappearance filling amount W1.

  By the way, the inventor of the present invention similarly applies to the gap disappearance filling amount W1 for a plurality of the same type of high-pressure tanks 10 (hereinafter also referred to as “tank B”) whose diameter of the cylinder portion is different from that of the tank A. The volume of pure water having the void disappearance filling amount W1 was measured. And the linear relationship which shows the change rate substantially the same as the graph Ga as shown by the graph Gb was obtained from the measurement result.

  From this result, if the linear relationship between the void disappearance filling amount W1 and the volume of the void 16 for a certain type of high-pressure tank 10 is known, the linear relationship of the different types of high-pressure tanks 10 is based on the linear relationship. It can be seen that can be obtained. Specifically, it is as follows.

  With respect to a certain type of high-pressure tank 10, a set of void disappearance filling amount W1 and a measured value of the volume of the void 16 are acquired, and according to the one set of measured values, the already acquired void disappearing filling amount W1 and the void The graph showing the relationship between the 16 volumes is shifted. Thereby, a linear relationship between the gap disappearance filling amount W1 and the volume of the gap 16 for the high-pressure tank 10 of that type can be obtained.

  In step S60 (FIG. 3), the determination unit 115 determines the quality of the high-pressure tank 10 as a product based on the volume V1 of the gap 16 acquired by the volume acquisition unit 114. Specifically, when the volume V1 is smaller than a predetermined threshold, the determination unit 115 determines that the size of the gap 16 is within an allowable range and determines “good” for the high-pressure tank 10, and determines the result. The data is output to a display unit (not shown). In this case, the control unit 110 ends the inspection process as it is.

  On the other hand, when the volume V1 is equal to or larger than the predetermined threshold, the determination unit 115 determines that the size of the gap 16 is out of the allowable range and the high pressure tank 10 is likely to have insufficient strength. On the other hand, “No” is determined, and the result is output to a display unit (not shown). In this case, the control unit 110 ends the inspection process after executing the warning process in step S80. Regardless of which determination is made, the control unit 110 outputs the volume of the gap 16 of the high-pressure tank 10 and the appropriate lower limit value of the internal pressure of the high-pressure tank 10 to the display unit and the like as inspection results.

  As described above, the inspection apparatus 100 according to this embodiment can easily and accurately measure the volume of the gap 16 by measuring the internal pressure while filling the high-pressure tank 10 with pure water. Therefore, the inspection accuracy for the gap 16 of the high-pressure tank 10 can be improved. Moreover, if it is the test | inspection apparatus 100 of this embodiment, the pressure P1 which is the lower limit value of the internal pressure of the high-pressure tank 10 which can lose | disappear or reduce the space | gap 16 simultaneously with the volume of the space | gap 16 can be acquired. Therefore, it is possible to appropriately determine a usage standard that allows the high-pressure tank 10 to continue to be used appropriately in a state where the gap 16 of the high-pressure tank 10 is almost eliminated.

B. Second embodiment:
FIG. 6 is a schematic diagram showing a configuration of a high-pressure tank inspection apparatus 200 according to the second embodiment of the present invention. The inspection apparatus 200 acquires a relationship representing a change in expansion amount relative to the internal pressure of the liner 11 in the high-pressure tank 10, acquires an evaluation value related to the strength of the high-pressure tank 10 based on the relationship, and based on the evaluation value. Whether the high-pressure tank 10 is good or bad is determined. The configuration of the high-pressure tank 10 is the same as the configuration described in the first embodiment.

  The inspection apparatus 200 includes a pure water tank 210, a weight scale 215, three pipes 221 to 223, two open / close valves 231, 232, a pump 233, a pressure sensor 241, a temperature sensor 242, and a pressure measurement value output. Unit 243 and control unit 250. The pure water tank 210 stores pure water supplied to the high-pressure tank 10. The weigh scale 215 measures the weight of pure water stored in the pure water tank 210 and outputs it to the control unit 250. The weight scale 215 may correct the output value according to the temperature of pure water in the pure water tank 210.

  One end of each of the first and second pipes 221 and 222 is connected to the pure water tank 210 and the other end is connected to one end of the third pipe 223 and merges. The other end of the third pipe 223 is connected to the valve 15 of the high-pressure tank 10. First and second on-off valves 231 and 232 are provided on the first and second pipes 221 and 222, respectively. The first pipe 221 is provided with a pump 233 between the pure water tank 210 and the first opening / closing valve 231. As the pump 233, for example, a booster pump may be employed, and a plunger pump may be employed for shortening the pressurization time.

  When increasing the internal pressure of the liner 11, the inspection device 200 opens the first on-off valve 231 and closes the second on-off valve 232, and supplies pure water in the pure water tank 210 to the first pipe by the driving force of the pump 233. 221 and the third pipe 223 are supplied to the liner 11. Further, the inspection apparatus 200 closes the first opening / closing valve 231 and opens the second opening / closing valve to reduce the internal pressure of the liner 11, and supplies the pure water filled in the liner 11 to the third pipe 223 and the second opening / closing valve. 2 is sent to the pure water tank 210 through the second pipe 222.

  The pressure sensor 241 is attached to the third pipe 223 and detects the pressure of pure water in the third pipe 223 as the internal pressure of the liner 11 in the high-pressure tank 10. The temperature sensor 242 is configured by a thermocouple thermometer, for example, and detects the temperature of pure water in the liner 11. The pressure measurement value output unit 243 receives the detection signal of the pressure sensor 241 and the detection signal of the temperature sensor 242. The pressure measurement value output unit 243 corrects the pressure value corresponding to the detection signal of the pressure sensor 243 according to the detection signal of the temperature sensor 242, and then outputs it to the control unit 250.

  The control unit 250 is configured by a microcomputer including a central processing unit and a main storage device. The control unit 250 includes a filling control unit 251, a measurement value recording unit 252, an evaluation value acquisition unit 253, and a determination unit 254 as functional units for executing an inspection process to be described later. The filling control unit 251 controls the opening and closing of the first and second on-off valves 231 and 232 and the driving of the pump 233 to control the amount of pure water in the high-pressure tank 10, thereby controlling the internal pressure (liner of the high-pressure tank 10. 11 internal pressure).

  The measurement value recording unit 252 records the output value of the pressure measurement value output unit 243 and the output value of the weigh scale 30. Here, the measured value recording unit 252 has a correspondence relationship between the filling amount of pure water in the high-pressure tank 10 and the expansion amount of the volume of the liner 11 of the high-pressure tank 10 in advance. The measurement value recording unit 252 acquires the relationship between the internal pressure and the expansion amount of the liner 11 based on the output value of the pressure measurement value output unit 243 and the output value of the weight scale 30 using the correspondence relationship. Although details will be described later, in the inspection apparatus 200, the internal pressure of the liner 11 is increased for each time of pressure increase (pressurization) for increasing the internal pressure of the liner 11 and for pressure decrease (during pressure decrease). Get the relationship with the amount of expansion.

  The evaluation value acquisition unit 253 acquires the permanent increase rate of the fiber reinforced resin layer 12 as an evaluation value related to the strength of the high-pressure tank 10 using the relationship acquired in the measurement value recording unit 252. The details of the permanent increase rate and its acquisition method will be described later. The determination unit 254 determines the quality of the strength of the high-pressure tank 10 based on the permanent increase rate acquired by the evaluation value acquisition unit 253.

  FIG. 7 is a flowchart showing a processing procedure of the inspection process of the high-pressure tank 10 executed in the inspection apparatus 200 of the second embodiment. Prior to the execution of this inspection process, the high-pressure tank 10 filled with pure water and in the initial filling state (described above) is attached to the inspection apparatus 200.

In step S100, the filling control unit 251 opens the first on-off valve 231 and closes the second on-off valve 232, drives the pump 233 to start supplying pure water to the high-pressure tank 10, and The internal pressure is increased from the initial pressure P ₀ to a predetermined test pressure Pt. The measurement value recording unit 252 records the output value of the weigh scale 215 and the output value of the pressure measurement value output unit 243, and acquires the relationship between the internal pressure and the expansion amount of the liner 11 at the time of pressurization. Hereinafter, the relationship between the internal pressure and the expansion amount of the liner 11 at the time of the pressure increase is also referred to as “first relationship”.

In step S <b> 110, the filling control unit 251 stops driving the pump 233, closes the first opening / closing valve 231, and opens the second opening / closing valve 232. As a result, delivery of pure water from the high-pressure tank 10 is started, and the internal pressure of the liner 11 begins to decrease. The measured value recording unit 252 records the output value of the weigh scale 215 and the output value of the pressure measurement value output unit 243 while the internal pressure of the liner 11 is decreased from the test pressure Pt to the initial pressure P ₀ . The relationship between the internal pressure of the liner 11 and the expansion amount is acquired. Hereinafter, the relationship between the internal pressure and the expansion amount of the liner 11 at the time of pressure reduction is also referred to as a “second relationship”.

  FIG. 8 is an explanatory diagram showing an example of a graph representing the first and second relationships obtained in steps S100 and S110. In FIG. 8, the horizontal axis represents pressure, the vertical axis represents the expansion amount (pure water filling amount), and a graph representing the first relationship obtained when the high-pressure tank 10 is pressurized is shown by a solid line. A graph representing the second relationship obtained at the time of step-down is shown by a one-dot chain line.

The graph representing the first relationship and the graph representing the second relationship are the same as the graph (FIG. 4) representing the relationship between the internal pressure of the high-pressure tank 10 and the amount of pure water described in the first embodiment. Obtained as a simple graph. Each of the graph representing the first relationship and the graph representing the second relationship is a curve region in which the expansion amount of the liner 11 increases in a convex manner with respect to the pressure in the vicinity of the initial pressure P ₀ . A linear region in which the expansion amount of the liner 11 linearly increases with respect to the pressure at the subsequent stage of the curved region.

  Here, in the graph representing the first relationship (solid line) and the graph representing the second relationship (dashed line), the graph representing the second relationship is more linear than the graph representing the first relationship. The slope of the change in is gradual, which makes them inconsistent. This is because once the high-pressure tank 10 expands, the expansion remains without being completely eliminated. It can be said that the strength of the fiber reinforced resin layer 12 is higher as the degree of expansion remains.

  In steps S120 to S150 (FIG. 7), the evaluation value acquisition unit 253 uses the fiber reinforced resin as an evaluation value related to the strength of the high-pressure tank 10 based on the first and second relationships acquired by the measurement value recording unit 252. Obtain the permanent increase rate of layer 12. The “permanent increase rate of the fiber reinforced resin layer 12” is a parameter indicating the degree of expansion remaining in the fiber reinforced resin layer 12 when the high-pressure tank 10 expands and contracts. The permanent increase rate of the fiber reinforced resin layer 12 is acquired as follows.

  FIG. 9 is an explanatory diagram for explaining the process of acquiring the permanent increase rate of the fiber reinforced resin layer 12 in steps S120 to S150. FIG. 9 is a graph showing the first and second relationships similar to FIG. Hereinafter, the processing contents of steps S120 to S150 will be described with reference to FIG.

In step S120, the evaluation value acquisition unit 253 acquires the first and second reference expansion amounts Ea and Eb of the fiber reinforced resin layer 12 based on the first and second relationships. Specifically, the evaluation value acquisition unit 253 detects a linear region in each of the first and second relationships. Then, by extrapolating the linear relationship between the internal pressure and the expansion of the liner 11 in their linear region to the initial pressure P _0, the initial pressure expansion amount obtained for P _0, respectively, first and second Acquired as reference expansion amounts Ea and Eb.

  FIG. 10 is an explanatory diagram for explaining a change in expansion of the fiber reinforced resin layer 12 when an internal pressure is applied. FIG. 10 shows an example of a graph showing a change in the expansion amount of the fiber reinforced resin layer 12 to which an internal pressure is applied, obtained by FEM (Finite Element Method), where the horizontal axis is pressure and the vertical axis is expansion amount. It is shown. When an internal pressure is applied to the fiber reinforced resin layer 12, the amount of expansion linearly increases according to the internal pressure.

  From the relationship shown in the graph of FIG. 10, it can be seen that the linear change in the first and second relationships shown in FIG. 9 is caused mainly by the expansion change of the fiber reinforced resin layer 12. By extrapolating the linear relationship in the linear region to the curved region, the expansion of the fiber reinforced resin layer 12 with respect to the change in the internal pressure of the liner 11 when a gap is generated between the liner 11 and the fiber reinforced resin layer 12. The change in quantity can be estimated.

  That is, the first reference expansion amount Ea can be interpreted as a value indicating the volume of the fiber reinforced resin layer 12 in the initial filling state before the start of the test. The second reference expansion amount Eb can be interpreted as a value indicating the volume of the fiber reinforced resin layer 12 when the internal pressure of the high-pressure tank 10 is increased to the test pressure Pt and then returned to the initial filling state.

  In step S <b> 130 (FIG. 7), the evaluation value acquisition unit 253 acquires the maximum expansion amount Em of the fiber reinforced resin layer 12. Here, “the maximum expansion amount Em of the fiber reinforced resin layer 12” means the maximum value of the volume change of the fiber reinforced resin layer 12 during the test of the high-pressure tank 10. The evaluation value acquisition unit 253 acquires the maximum expansion amount Et of the liner 11 with respect to the test pressure Pt based on the first and second relationships. Then, the evaluation value acquisition unit 253 acquires the difference between the maximum expansion amount Et of the liner 11 and the first reference expansion amount Ea as the maximum expansion amount Em of the fiber reinforced resin layer 12 (Em = Et−Ea).

  In step S140, the evaluation value acquisition unit 253 acquires the permanent expansion amount Ep of the fiber reinforced resin layer 12. Here, the “permanent expansion amount Ep of the fiber reinforced resin layer 12” means the expansion amount remaining in the fiber reinforced resin layer 12 when the internal pressure of the high pressure tank 10 is changed, and the fluctuation of the internal pressure of the high pressure tank 10. It is a volume change amount of the fiber reinforced resin layer 12 before and after. The evaluation value acquisition unit 253 acquires the difference between the second reference expansion amount Eb and the first reference expansion amount Ea as the permanent expansion amount Ep of the fiber reinforced resin layer 12 (Ep = Eb−Ea).

  In step S150, the permanent increase rate Ri of the fiber reinforced resin layer 12 is acquired as a ratio of the permanent expansion amount Ep of the fiber reinforced resin layer 12 to the maximum expansion amount Em of the fiber reinforced resin layer 12 (Ri = Ep / Em). Thus, according to the inspection apparatus 200 of the second embodiment, the permanent increase rate of the fiber reinforced resin layer 12 can be acquired based on the change in the expansion amount of the liner 11 with respect to the change in the internal pressure of the high-pressure tank 10. .

  In step S <b> 160, the determination unit 254 determines pass / fail regarding the strength of the high-pressure tank 10 based on the permanent increase rate Ri of the fiber reinforced resin layer 12 acquired by the evaluation value acquisition unit 253. Specifically, when the permanent increase rate Ri of the fiber reinforced resin layer 12 is smaller than a predetermined threshold, the determination unit 254 assumes that the fiber reinforced resin layer 12 has sufficient strength and Judge “good”. In this case, the control unit 250 outputs the result to a display unit (not shown) and ends the inspection process.

  On the other hand, in step S160, when the permanent increase rate Ri of the fiber reinforced resin layer 12 is equal to or greater than a predetermined threshold, the determination unit 254 assumes that the strength of the fiber reinforced resin layer 12 of the high-pressure tank 10 may be insufficient. Then, “No” is determined for the high-pressure tank 10. In this case, the control unit 250 ends the inspection process after executing the warning process in step S170. In any case, the control unit 250 checks the maximum expansion amount Em, the permanent expansion amount Ep, and the permanent increase rate Ri of the fiber reinforced resin layer 12 on a display unit (not shown) or the like. It may be displayed as a result.

  As described above, according to the inspection apparatus 200 of the second embodiment, the permanent increase rate that is a measure of the strength of the fiber reinforced resin layer 12 can be easily and accurately adjusted by changing the internal pressure of the high-pressure tank 10 on a trial basis. Can be obtained at. In addition, since the strength of the high-pressure tank 10 can be determined based on the permanent increase rate, the determination accuracy for the strength of the high-pressure tank 10 can be improved.

C. Third embodiment:
FIG. 11 is a flowchart showing the processing procedure of the inspection processing of the high-pressure tank 10 as the third embodiment of the present invention. This inspection process is executed in an inspection apparatus having the same configuration as the inspection apparatus 200 (FIG. 6) described in the second embodiment. In this test process, on the basis of the change rate of the fiber-reinforced resin layer 12 with respect to the internal pressure of the high-pressure tank 10, a determination of the intensity of the high-pressure tank 10.

At step S100, in the same manner as described in the second embodiment, the filling control unit 251 boosts the internal pressure of the high-pressure tank 10 from the initial pressure P ₀ to the test pressure Pt, measurement value recording unit 252 is the liner during its boost 11 (first relationship) between the internal pressure and the expansion amount. In step S <b> 105, the evaluation value acquisition unit 253 detects a linear region in the first relationship acquired by the measurement value recording unit 252, and acquires a change rate of the expansion amount with respect to the internal pressure of the liner 11 in the linear region. In step S161, the determination unit 254 performs pass / fail determination on the strength of the high-pressure tank 10 based on the rate of change.

  FIG. 12 is an explanatory diagram for explaining the strength determination of the high-pressure tank 10 in step S161. FIG. 12 shows an example of a graph showing the relationship between the internal pressure and the expansion amount of the liner 11 at the time of pressurization, which is obtained in step S100. FIG. 12 shows an example of the allowable range AR of the change rate α in the linear region with hatching. In FIG. 12, an example of a graph when the determination unit 254 determines “No” (NG determination) is indicated by a broken line.

  As described above, the evaluation value acquisition unit 253 acquires the change rate of the expansion amount with respect to the internal pressure of the liner 11 in the linear region of the first relationship in Step S105. Here, the determination unit 254 stores a reference change rate α in advance. When the change rate acquired by the evaluation value acquisition unit 253 is within a predetermined allowable range with respect to the change rate α (for example, within a range of α ± 10%), the determination unit 254 determines the fiber reinforced resin layer 12. The strength of the high-pressure tank 10 is determined as “good”. On the other hand, the determination unit 254 determines that the strength of the fiber reinforced resin layer 12 is insufficient when the rate of change acquired by the evaluation value acquisition unit 253 is out of the predetermined allowable range. Judgment of “No” is made with respect to the intensity.

  If a determination result of “good” is obtained in step S161, the control unit 250 ends the inspection process as it is, and if a determination result of “no” is obtained, executes a warning process in step S170. After that, the inspection process is terminated. In any determination, the control unit 250 may display the strength level of the fiber reinforced resin layer 12 according to the value of the change rate acquired by the evaluation value acquisition unit 253 as the inspection result.

  As described above, with the inspection process according to the third embodiment, it is possible to easily determine the strength of the fiber reinforced resin layer 12 of the high-pressure tank 10.

D. Fourth embodiment:
FIG. 13 is a schematic diagram showing a configuration of an inspection apparatus 200A for the high-pressure tank 10 as the fourth embodiment of the present invention. The inspection apparatus 200A has the same configuration as that of the inspection apparatus described in the third embodiment except that first and second optical heads 261 and 262 and a head control unit 265 are added. ing. In addition, this inspection apparatus 200A performs the inspection process of the high-pressure tank 10 in the same procedure as described in the third embodiment except for the points described below (FIG. 11).

  Each of the first and second optical heads 261 and 262 is an optical scanner device that includes a light emitting unit that emits laser light and a light receiving unit that receives the reflected light. The first optical head 261 reciprocates in the central axis direction of the high-pressure tank 10 to optically scan the entire high-pressure tank 10 in the central axis direction. The second optical head 262 reciprocates in the radial direction of the high-pressure tank 10 to optically scan the entire radial direction of the high-pressure tank 10.

  The head controller 265 controls the first and second optical heads 261 and 262. The head controller 265 detects the change in the size of the high-pressure tank 10 in the central axis direction and the change in the size of the high-pressure tank 10 in the radial direction by the first and second optical heads 261 and 262. The head controller 265 calculates the amount of change in the volume of the high-pressure tank 10 using the detected value, and outputs it to the controller 250.

  With this configuration, the inspection apparatus 200A of the fourth embodiment optically detects a change in the expansion amount accompanying a change in the internal pressure of the high-pressure tank 10. The measurement value recording unit 252 of the control unit 250 includes a measurement value of the internal pressure of the high-pressure tank 10 received from the pressure measurement value output unit 243, a measurement value of the volume change amount of the high-pressure tank 10 received from the head control unit 265, And the relationship between the internal pressure of the high-pressure tank 10 and the amount of expansion of the fiber reinforced resin layer 12 at the time of pressurization is acquired. This relationship is acquired as a linear relationship similar to the linear region in the graph of FIG.

  The evaluation value acquisition unit 253 acquires the rate of change of the expansion amount of the fiber reinforced resin layer 12 with respect to the internal pressure of the high-pressure tank 10 during pressure increase in the relationship acquired by the measurement value recording unit 252. Based on the rate of change, the strength of the fiber reinforced resin layer 12 is determined in the same manner as described in the third embodiment, and the quality of the high-pressure tank 10 is determined.

  As described above, according to the inspection apparatus 200A of the fourth embodiment, the expansion amount of the high-pressure tank 10 is optically measured by the first and second optical heads 261 and 262. Therefore, since the change amount of the expansion amount can be measured more accurately than the configuration of the third embodiment in which the expansion amount of the high-pressure tank 10 is acquired based on the filling amount of pure water, the inspection accuracy of the high-pressure tank 10 is improved. Can be improved.

E. Variation:
E1. Modification 1:
In each of the above embodiments, the high-pressure tank 10 is filled with pure water in the inspection devices 100, 200, and 200A. However, the inspection devices 100, 200, and 200A may fill the high-pressure tank 10 with a fluid other than pure water. For example, the fluid filled in the high-pressure tank 10 by the inspection apparatuses 100, 200, and 200A may be a high-pressure gas such as high-pressure hydrogen, or may be a powder.

E2. Modification 2:
In the first embodiment, the inspection apparatus 100 uses the filling amount of the pure water when the change in the filling amount of the pure water with respect to the internal pressure of the high-pressure tank 10 changes from a curved change to a linear change. It was acquired as the filling amount of pure water when the outer surface was in contact with the inner surface of the fiber reinforced resin layer 12, that is, when the void 16 was lost in the high-pressure tank 10. However, the inspection apparatus 100 may acquire the pure water filling amount at a timing other than when the change in the pure water filling amount with respect to the internal pressure of the high-pressure tank 10 changes from a curved change to a linear change. The inspection apparatus 100 may acquire the filling amount of pure water when the gap 16 is in a predetermined state. The inspection apparatus 100 observes a predetermined part of the high-pressure tank 10 with, for example, an X-ray CT scanner, and the interval between the liner 11 and the fiber reinforced resin layer 12 is reduced to a predetermined width at the part, and the gap 16 is formed. A decreased state may be detected. In this case, it is possible to acquire the volume corresponding to the decrease in the gap 16, and the inspection apparatus 100 can detect that the gap 16 exceeding the volume exists.

E3. Modification 3:
In each said embodiment, inspection apparatus 100,200,200A determines the quality about the high-pressure tank 10 based on the volume of the acquired space | gap 16, the permanent increase rate of the fiber reinforced resin layer 12, and the change rate in a linear area | region. The result was output. However, the inspection devices 100, 200, and 200 A do not have to execute the determination about the quality of the high-pressure tank 10 and do not need to output the determination result. The inspection devices 100, 200, and 200A may acquire at least values related to the strength of the high-pressure tank 10, such as the volume of the gap 16, the permanent increase rate of the fiber reinforced resin layer 12, and the rate of change in the linear region. For example, the inspection apparatus 200 according to the second embodiment may have a configuration in which only the permanent expansion amount of the fiber reinforced resin layer 12 is obtained and output.

E4. Modification 4:
In each of the above-described embodiments, the high-pressure tank 10 is a test object that is manufactured by the FW method. However, the high-pressure tank 10 to be inspected by the inspection apparatuses 100, 200, and 200A may not be formed by the FW method. The high-pressure tank 10 to be inspected by the inspection apparatuses 100, 200, and 200 A may have a reinforcing layer other than the fiber reinforced resin layer 12 as the reinforcing layer of the liner 11.

E5. Modification 5:
In the first embodiment, the inspection apparatus 100 detects that the change in the filling amount of the pure water with respect to the internal pressure of the high-pressure tank 10 is linear, whereby the gap 16 has disappeared in the high-pressure tank 10. The condition was detected. Here, in a state where “the change tendency of the filling amount of the pure water with respect to the internal pressure of the high-pressure tank 10 is linear”, the inclination and intercept of the approximate straight line of the change are SL and ΔWi, respectively, and the initial filling state When the volume of the accommodation space SP at VSP is V _SP , a state in which an approximate straight line is included in a range sandwiched between the straight lines of the slope SL obtained by adding ± 1% to the intercept ΔWi (a) may be included ( FIG. 4).

  The present invention is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the above effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

E6. Modification 6:
In the inspection process of the high-pressure tank 10 of the second embodiment, the permanent expansion amount and the permanent increase rate are acquired based on the first and second relationships. However, in the inspection process of the high-pressure tank 10, it is not necessary to acquire the permanent expansion amount or the permanent increase rate. In the inspection process of the high-pressure tank 10, a value related to the strength of the fiber reinforced resin layer 12 may be acquired based on the difference in linear relationship between the linear regions of the first and second relationships.

E7. Modification 7:
In the said 3rd Embodiment and 4th Embodiment, the quality determination of the high pressure tank 10 was performed based on the relationship between the internal pressure of the high pressure tank 10 at the time of pressure | voltage rise of an internal pressure, and the expansion amount. However, instead of the relationship between the internal pressure and the expansion amount of the high-pressure tank 10 when the internal pressure is increased, the pass / fail judgment of the high-pressure tank 10 is performed based on the relationship between the internal pressure and the expansion amount of the high-pressure tank 10 when the internal pressure is decreased. Also good.

E8. Modification 8:
In the fourth embodiment, the first and second optical heads 261 and 262 scan the high-pressure tank 10 with laser light to detect the change amount (expansion amount) of the volume of the high-pressure tank 10. However, one of the first and second optical heads 261 and 262 may be omitted. The first and second optical heads 261 and 262 may detect a change in the volume of the high-pressure tank 10 using diffused light that irradiates the entire high-pressure tank 10 instead of scanning with laser light.

DESCRIPTION OF SYMBOLS 10 ... High pressure tank 11 ... Liner 12 ... Fiber reinforced resin layer 13 ... Valve side nozzle 14 ... End side nozzle 15 ... Valve 16 ... Air gap 20 ... Pure water tank 30 ... Weigh scale 40 ... Pump 50 ... Pressure detector 60 ... Piping 100 ... Inspection device 110 ... Control unit 111 ... Filling control unit 112 ... Measurement unit 113 ... Recording unit 114 ... Volume acquisition unit 115 ... Determination unit 200 ... Inspection device 200A ... Inspection device 210 ... Pure water tank 215 ... Weigh scale 221 ... First piping 222 ... second piping 223 ... third piping 231 ... first opening / closing valve 232 ... second opening / closing valve 233 ... pump 241 ... pressure sensor 242 ... temperature sensor 243 ... pressure measurement value output unit 250 ... control unit 251 ... Filling control unit 252 ... Recording unit 253 ... Evaluation value acquisition unit 254 ... Determination unit 261 ... First optical head 262 ... Second optical head De 265 ... head control unit SP ... housing space

Claims (14)

A method for inspecting a high-pressure tank comprising a hollow tank container and a reinforcing layer formed on the outer surface of the tank container,
(A) changing the internal pressure of the tank container and obtaining a relationship representing a change in the expansion amount of the tank container with respect to a change in the internal pressure of the tank container;
(B) detecting a linear region in which the expansion amount of the tank container linearly changes with respect to the internal pressure of the tank container in the relationship acquired in the step (a), and based on the linear relationship in the linear region, Obtaining a value relating to the strength of the high-pressure tank;
An inspection method comprising: The inspection method according to claim 1,
In the step (a), the filling amount of the fluid in the tank container is increased to increase the internal pressure of the tank container, and the relationship between the internal pressure of the tank container and the filling amount of the fluid is determined by the internal pressure of the tank container. Obtaining a relationship representing a change in expansion amount of the tank container with respect to a change,
The step (b)
(B1) detecting a linear region in which the fluid filling amount linearly changes with respect to the internal pressure of the tank container in the relationship between the internal pressure of the tank container and the filling amount of the fluid;
(B2) obtaining a filling amount of the fluid at a starting end of the linear region as a value when a gap between the tank container and the reinforcing layer disappears;
(B3) Based on the correspondence prepared in advance between the volume of the gap and the filling amount of the fluid, the volume of the gap with respect to the value of the filling amount of the fluid acquired in the step (b2) Obtaining a value relating to the strength of the high-pressure tank;
Including an inspection method. The inspection method according to claim 2, further comprising:
(C1) An inspection method comprising a step of outputting a quality result of the high-pressure tank based on the volume of the gap acquired in the step (b3). The inspection method according to claim 1,
The step (a)
(A1) The amount of fluid in the tank container is increased to increase the internal pressure of the tank container from the first pressure to the second pressure, and the expansion amount of the tank container with respect to the increase in the internal pressure of the tank container Obtaining a first relationship representing an increasing change in
(A2) reducing the filling amount of the fluid in the tank container to reduce the internal pressure of the tank container from the second pressure to the first pressure, and the tank container against a decrease in the internal pressure of the tank container Obtaining a second relationship representing a decrease change in the expansion amount of
Including
In the step (b), in each of the first relationship and the second relationship, a first linear region and a second linear region in which an expansion amount of the tank container changes linearly with respect to an internal pressure of the tank container. And detecting the linear region of the reinforcing layer based on the difference between the first linear relationship and the second linear relationship, which is a linear relationship in each of the first linear region and the second linear region. An inspection method, which is a process of acquiring a value. The inspection method according to claim 4,
The step (b) extrapolates each of the first linear relationship and the second linear relationship to the first pressure, and a first expansion amount and a second expansion amount with respect to the first pressure. And obtaining a residual expansion amount of the reinforcing layer, which is a difference between the first expansion amount and the second expansion amount, as a value related to the strength of the reinforcing layer. The inspection method according to claim 5,
The step (b) further obtains the expansion amount of the tank container with respect to the second pressure as the maximum expansion amount of the reinforcing layer in the first relationship or the second relationship, and An inspection method including a step of obtaining a permanent increase rate of the reinforcing layer based on the residual expansion amount. The inspection method according to claim 6, further comprising:
(C2) An inspection method comprising a step of outputting a result of quality of the high-pressure tank based on the permanent increase rate. The inspection method according to claim 1,
Wherein step (b) is a step of obtaining an expansion rate of change of the tank container against the inner pressure of the tank vessel in the linear region as a value related to the intensity of the high-pressure tank, the inspection method. The inspection method according to claim 8, further comprising:
(C3) An inspection method comprising a step of outputting a pass / fail result of the high-pressure tank based on the rate of change. The inspection method according to claim 8 or 9, wherein
The said process (a) is a test | inspection method which is a process of acquiring the volume change of the said high-pressure tank as a change of the expansion amount of the said tank container with an optical sensor. The inspection method according to any one of claims 1 to 9,
The tank container is made of a resin member,
The said reinforcement layer is a test | inspection method which is a fiber reinforced resin layer formed by winding fiber reinforced resin around the said tank container, and making it thermoset. An inspection apparatus for a high-pressure tank comprising a hollow tank container and a reinforcing layer formed on the outer surface of the tank container,
An expansion test unit that changes the internal pressure of the tank container and obtains a relationship representing a change in the expansion amount of the tank container with respect to a change in the internal pressure of the tank container;
A linear region in which the expansion amount of the tank container linearly changes with respect to the internal pressure of the tank container in the relationship acquired by the expansion test unit is detected, and based on the linear relationship in the linear region, the high pressure tank A strength verification unit for obtaining values related to strength;
An inspection apparatus comprising: The inspection apparatus according to claim 12,
The expansion test unit increases the fluid filling amount in the tank container to increase the internal pressure of the tank container, and the relationship between the internal pressure of the tank container and the fluid filling amount changes the internal pressure of the tank container. Obtained as a relationship representing a change in the expansion amount of the tank container with respect to
The strength verification unit
A linear region detecting unit that detects a linear region in which the fluid filling amount linearly changes with respect to the internal pressure of the tank container in the relationship between the internal pressure of the tank container and the fluid filling amount;
The filling amount of the fluid at the beginning of the linear region is obtained as a value when the gap between the tank container and the reinforcing layer disappears, and is between the volume of the gap and the filling amount of the fluid. An inspection apparatus comprising: a void volume acquisition unit that acquires the volume of the void with respect to the value as a value related to the strength of the high-pressure tank based on a correspondence prepared in advance. The inspection apparatus according to claim 12,
The expansion test section is
(I) Increasing the filling amount of the fluid in the tank container to increase the internal pressure of the tank container from the first pressure to the second pressure, and the expansion amount of the tank container with respect to the increase in the internal pressure of the tank container Obtaining a first relationship representing an increasing change in
(Ii) reducing the filling amount of the fluid in the tank container to reduce the internal pressure of the tank container from the second pressure to the first pressure, and the tank container against a decrease in the internal pressure of the tank container Obtaining a second relationship representing a decrease change in the expansion amount of
The strength verification unit includes a first linear region and a second linear region in which an expansion amount of the tank container linearly changes with respect to an internal pressure of the tank container in each of the first relationship and the second relationship. A value relating to the strength of the reinforcing layer is detected based on a difference between the first linear relationship and the second linear relationship, which is a linear relationship in each of the first linear region and the second linear region. Get the inspection device.

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