Pressure device

Abstract

To perform control of pressure inside a pressure container in a holding step with good accuracy.SOLUTION: A piston axial force information detecting part 53 detects piston axial force information concerning axial force acting on a piston main body 21. A friction information memorizing part 62 memorizes friction information concerning friction force between a piston seal 23 and a pressure container 10 when the piston main body 21 moves with respect to the pressure container 10. A driving control part 65 controls a driving device 40 on the basis of the piston axial force information and the friction information. In a holding step of controlling pressure inside the pressure container 10 so that the pressure is held constant, the driving control part 65 controls the driving device 40 so that the piston main body 21 reciprocates with respect to the pressure container 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pressurizing device for pressurizing the inside of a pressure vessel. [Background technology]

[0002] For example, Patent Document 1 describes a pressurizing device that pressurizes the inside of a pressure vessel with a piston. In the technology described in this document, the relationship between the pressure inside the pressure vessel (internal vessel pressure) and the amount of piston distortion when the piston is pushed in and pulled out is measured in advance. The packing resistance is calculated from the relationship between the internal vessel pressure and the amount of piston distortion. When the piston is pushed in (in the pressurizing stroke), the packing resistance is subtracted from the amount of piston distortion, and when the piston is pulled out (in the depressurizing stroke), the packing resistance is added to the amount of piston distortion, thereby measuring the internal vessel pressure (Claim 1 of the same document). Furthermore, in the technology described in the same document, the internal vessel pressure is controlled to a target pressure (set pressure) (paragraphs

[0016] to

[0021] of the same document). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3254256 Summary of the Invention [Problem to be solved by the invention]

[0004] The document does not describe how to control the pressure inside the vessel during the pressure holding step. It is desirable to control the pressure inside the pressure vessel with high accuracy during the pressure holding step.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a pressurizing device that can accurately control the pressure inside the pressure vessel during the holding process. [Means for solving the problem]

[0006] The pressurizing device comprises a pressure vessel, a piston body, a piston seal, a piston axial force information detection unit, a drive unit, a friction information storage unit, and a drive control unit. The piston body is fitted inside the pressure vessel so as to be movable toward the insertion side and the withdrawal side relative to the pressure vessel. The piston seal is provided on the piston body and seals the gap between the piston body and the pressure vessel. The piston axial force information detection unit detects piston axial force information related to the axial force acting on the piston body in the direction of movement of the piston body relative to the pressure vessel. The drive unit moves the piston body relative to the pressure vessel. The friction information storage unit stores friction information related to the friction force between the piston seal and the pressure vessel when the piston body moves relative to the pressure vessel. The drive control unit controls the drive unit based on the piston axial force information detected by the piston axial force information detection unit and the friction information stored in the friction information storage unit. The drive control unit controls the drive device so that the piston body reciprocates relative to the pressure vessel during a pressure maintaining process in which the pressure inside the pressure vessel is controlled to be constant. [Effects of the Invention]

[0007] With the above configuration, the pressure inside the pressure vessel can be controlled with high precision during the holding step. [Brief explanation of the drawings]

[0008] [Figure 1] 1A and 1B are diagrams showing a cross-sectional view of a pressure device 1 and the like. [Figure 2] FIG. 2 is a block diagram showing a controller 60 and other components shown in FIG. 1. [Figure 3] 2 is a graph showing information obtained by a preliminary measurement using the pressure device 1 shown in FIG. 1. [Figure 4] 3 is a graph showing the set pressure set in the set pressure setting unit 63 shown in FIG. 2, etc.; [Figure 5] 5 is a graph showing the internal pressure of the container during the holding step and the like shown in FIG. 4. [Figure 6] This is a view equivalent to FIG. 5, but with a different internal pressure in the container from the example shown in FIG. [Figure 7] 5 when the piston body 21 shown in FIG. 1 is reciprocated before the start of the holding stroke shown in FIG. 5. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] The pressure device 1 will be described with reference to FIGS.

[0010] The pressurizing device 1 is a device that pressurizes an object O to be pressurized in a pressure vessel 10. The pressurizing device 1 is a piston-type pressurizing device that applies pressure by the pressing force of a piston 20.

[0011] The pressurizing device 1 is, for example, an isostatic pressing (IP) device. The pressurizing device 1 isostatically pressurizes the workpiece O3 in the pressure vessel 10 by pressurizing the pressure medium O1 in the pressure vessel 10, thereby processing the workpiece O3. For example, the pressurizing device 1 may be a hot isostatic pressing (HIP) device (e.g., a piston-type hot isostatic pressing device). In this case, the pressurizing device 1 may be an ultra-high pressure hot isostatic pressing device that pressurizes the pressure medium O1 to approximately 1000 MPa, or an ultra-ultra-high pressure hot isostatic pressing device that pressurizes the pressure medium O1 to an even higher pressure. For example, the pressurizing device 1 may be a warm isostatic pressing (WIP) device or a cold isostatic pressing (CIP) device. The pressure medium O1 may be a gas (e.g., a noble gas). The pressure medium O1 may be a liquid, for example, a liquid that solidifies at room temperature (for example, molten salt).

[0012] The pressurizing device 1 does not necessarily have to pressurize the object to be pressurized O3 by pressurizing the pressure medium O1. The object to be pressurized O does not have to include the pressure medium O1 and the object to be pressurized O3. The pressurizing device 1 may also be a device (such as a measuring device or an experimental device) that measures the state of the object to be pressurized O. Specifically, the pressurizing device 1 may be a device that reproduces the state of magma underground, or a device that pressurizes and heats the same material as the magma contained in the pressure vessel 10. The pressurizing device 1 may also be a single crystal growth furnace. For example, the pressurizing device 1 may be a device for producing a compound semiconductor single crystal of GaN (gallium nitride). Specifically, the pressurizing device 1 may be a device for performing a high-temperature, high-pressure synthesis method in which nitrogen gas is dissolved in a gallium solution under an ultra-high-pressure nitrogen gas atmosphere and crystals are grown in a supersaturated state. The following mainly describes the case in which the object to be pressurized O includes the pressure medium O1 and the object to be pressurized O3.

[0013] (Direction definition) As will be described later, the piston 20 moves relative to the pressure vessel 10. The direction of movement of the piston 20 relative to the pressure vessel 10 is defined as the axial direction Z. In the axial direction Z, the side (facing) where the piston 20 is inserted into the pressure vessel 10 is defined as the insertion side Z1, and the opposite side (opposite direction) is defined as the withdrawal side Z2. The withdrawal side Z2 is the side where the piston 20 is withdrawn from the pressure vessel 10. The axial direction Z may be, for example, an up-down direction (vertical direction), a horizontal direction, or a direction inclined relative to the up-down direction and the horizontal direction. When the axial direction Z is an up-down direction, the insertion side Z1 may be either the upper side or the lower side (the same applies to the withdrawal side Z2). The axis passing through the center of the piston 20 and extending in the axial direction Z is defined as the central axis A. The diameter direction of an imaginary circle (not shown) on a plane perpendicular to the central axis A and centered on the central axis A is defined as the "radial direction."

[0014] This pressurizing device 1 includes a frame 5, a pressure vessel 10, a piston 20, a pressure vessel internal member 30, a drive unit 40, a piston position information detection unit 51, a piston axial force information detection unit 53, a controller 60, and a pressure notification unit 70. During preliminary measurement, which will be described later, the pressurizing device 1 includes a pressure detection member 80.

[0015] The frame 5 is a structure that receives (supports) forces in the axial direction Z. The frame 5 supports the pressure vessel 10 and the drive unit 40 (more specifically, the fluid pressure cylinder 41 (described later)). The frame 5 supports the pressure vessel 10 and the fluid pressure cylinder 41 from both sides (e.g., top and bottom) outside the axial direction Z. For example, the frame 5 is oval-shaped (not shown). In this case, the frame 5 includes two semicircular or approximately semicircular yoke sections and two linear column sections connecting the two yoke sections. In this case, the frame 5 shown in FIG. 1 is part of the yoke section (yoke frame). Note that the frame 5 does not have to be oval-shaped, and the frame 5 shown in FIG. 1 does not have to be a yoke frame.

[0016] The pressure vessel 10 is a vessel that contains an object to be pressurized O. The pressure vessel 10 contains a pressure vessel internal member 30. The pressure vessel 10 is configured to form a space surrounded by the pressure vessel 10 and a piston 20. For example, the pressure vessel 10 includes a pressure vessel body 11 and a pressure vessel lid 13.

[0017] The pressure vessel body 11 is a tubular (for example, cylindrical) member extending in the axial direction Z.

[0018] The pressure vessel lid 13 closes (seals) an opening on one side (e.g., the upper side) of the pressure vessel body 11 in the axial direction Z. When the pressure vessel lid 13 is provided on the upper portion of the pressure vessel 10, the pressure vessel lid 13 is an "upper lid." The pressure vessel lid 13 may have a hole (e.g., a gas inlet, not shown) for introducing the pressure medium O1.

[0019] The piston 20 is a member that applies pressure to the inside of the pressure vessel 10. The piston 20 closes (seals) the opening on the other side of the pressure vessel body 11 in the axial direction Z (the side opposite to the side on which the pressure vessel lid 13 is provided). When the piston 20 is provided in the lower part of the pressure vessel 10, the piston 20 is a "lower lid." The piston 20 comprises a piston body 21 and a piston seal 23.

[0020] The piston body 21 is the main body portion of the piston 20. The piston body 21 is fitted (inserted) into the pressure vessel 10. The piston body 21 is fitted into the pressure vessel 10 via a piston seal 23. The piston body 21 is movable toward an insertion side Z1 and a withdrawal side Z2 with respect to the pressure vessel 10. The piston body 21 is slidable relative to the pressure vessel 10 via the piston seal 23. For example, the piston body 21 includes a piston body columnar portion 21a and a piston body base portion 21b. The piston body columnar portion 21a is the insertion side Z1 portion of the piston body 21. At least a portion of the piston body columnar portion 21a is inserted into the pressure vessel 10. The piston body columnar portion 21a is columnar (for example, cylindrical) and extends in the axial direction Z. The piston body base portion 21b is the withdrawal side Z2 portion of the piston body 21. The piston body base portion 21b is not inserted into the pressure vessel 10. The piston body base portion 21b protrudes radially outward from the piston body columnar portion 21a.

[0021] The piston seal 23 is a member (packing) that seals the gap between the piston body 21 and the pressure vessel 10. The piston seal 23 is provided on the piston body 21, and on the piston body columnar portion 21a. The piston seal 23 is provided on the insertion side Z1 portion of the piston body columnar portion 21a. The piston seal 23 is provided on the radially outer surface (e.g., the outer peripheral surface) of the piston body columnar portion 21a. For example, the piston seal 23 is made of an elastic member (e.g., rubber, resin, etc.). The piston seal 23 is annular (e.g., circular). The piston seal 23 moves in the axial direction Z integrally with the piston body 21. The piston seal 23 slides relative to the pressure vessel 10.

[0022] This piston seal 23 contacts the pressure vessel 10. More specifically, the piston seal 23 contacts the inner surface (e.g., the inner circumferential surface) of the pressure vessel body 11. The piston seal 23 receives pressure from the object to be pressurized O (e.g., the pressure medium O1), deforms, and presses the inner surface of the pressure vessel 10 radially outward. The frictional force between the piston seal 23 and the pressure vessel 10 is called the "piston seal frictional force." This piston seal frictional force is of a magnitude that cannot be ignored in controlling the pressure inside the pressure vessel 10 (referred to as the "vessel internal pressure"). Therefore, the vessel internal pressure is controlled based on information related to the piston seal frictional force (friction information) (described below).

[0023] The pressure vessel internal member 30 is a member provided inside the pressure vessel 10. For example, when the pressurizing device 1 is a hot isostatic pressing device, the pressure vessel internal member 30 includes a support 31, a heat insulating layer 33, and a heating device 35.

[0024] The support 31 supports the article O3 to be treated and the like relative to the piston body 21. The support 31 supports the article O3 to be treated so that the article O3 to be treated is positioned closer to the insertion side Z1 than the piston body 21. The support 31 supports the heat insulating layer 33 and the heating device 35 in the same manner as the article O3 to be treated.

[0025] The insulating layer 33 stores the product to be treated O3. The insulating layer 33 provides insulation between the space within the insulating layer 33 and the space within the pressure vessel 10 but outside the insulating layer 33. The insulating layer 33 is configured to transmit pressure between the space within the insulating layer 33 and the space within the pressure vessel 10 but outside the insulating layer 33. For example, a gap may be provided between the insulating layer 33 and the support 31.

[0026] The heating device 35 (heater, heater element) heats the inside of the pressure vessel 10. For example, the heating device 35 heats the inside of the insulating layer 33 and heats the workpiece O3 to be treated. The heating device 35 is arranged inside (radially inside) the insulating layer 33. The heating device 35 is arranged around (radially outside) the workpiece O3 to be treated. Note that if the pressurizing device 1 is a cold isostatic pressing device, the insulating layer 33 and the heating device 35 do not need to be provided, and for example, a member (such as a rubber mold) for accommodating the workpiece O3 to be treated may be provided.

[0027] The drive device 40 is a device that moves (drives) the piston body 21 relative to the pressure vessel 10. The drive device 40 moves the piston body 21 in the axial direction Z. The drive device 40 may be a fluid pressure drive device that moves the piston body 21 by the pressure (fluid pressure) of a working fluid. For example, the drive device 40 may be a hydraulic drive device that moves the piston body 21 by hydraulic pressure. The drive device 40 may also be a device that moves the piston body 21 by power other than fluid pressure (for example, electricity). The following mainly describes the case where the drive device 40 is a fluid pressure drive device. The drive device 40 includes a fluid pressure cylinder 41, fluid pressure piping 43, a fluid pressure detection unit 45, and a fluid pressure control unit 47.

[0028] The fluid pressure cylinder 41 uses fluid pressure to move the piston body 21. The fluid pressure cylinder 41 is, for example, a hydraulic cylinder, etc. The fluid pressure cylinder 41 includes a cylinder body 41a, a cylinder seal 41b, a ram 41c, and a ram seal 41d.

[0029] The cylinder body 41a accommodates the portion of the ram 41c on the withdrawal side Z2. The cylinder body 41a includes a head side chamber 41a1 and a ram side chamber 41a2. The head side chamber 41a1 is a space (e.g., an oil chamber) to which hydraulic fluid is supplied when the ram 41c (the piston body 21) moves toward the insertion side Z1. The head side chamber 41a1 is a space inside the cylinder body 41a and closer to the withdrawal side Z2 than the ram base 41c1 (described later). The ram side chamber 41a2 is a space (e.g., an oil chamber) to which hydraulic fluid is supplied when the ram 41c (the piston body 21) moves toward the withdrawal side Z2. The ram side chamber 41a2 is a space inside the cylinder body 41a and closer to the insertion side Z1 than the ram base 41c1. Note that the movement of the ram 41c (of the piston body 21) toward the withdrawal side Z2 does not necessarily have to be performed by fluid pressure. For example, the movement of the ram 41c (of the piston body 21) toward the pull-out side Z2 may be performed by the elastic force of a spring (not shown), or by the weight of the piston 20 itself.

[0030] The cylinder seal 41b is a member (packing) that seals the gap between the cylinder body 41a and the ram 41c. The cylinder seal 41b is provided on the piston body 21, and more specifically, on the radially inner portion (e.g., inner peripheral portion) of the insertion side Z1 portion of the piston body 21. The cylinder seal 41b contacts the ram 41c, and more specifically, on the radially outer surface (e.g., outer peripheral surface) of the ram column portion 41c2 (described later). For example, the cylinder seal 41b is made of an elastic member (e.g., rubber, resin, etc.). The cylinder seal 41b is annular (e.g., circular).

[0031] The ram 41c moves the piston body 21 in the axial direction Z. For example, the ram 41c may be separate from the piston body 21 and fixed to the piston body 21. In this case, the ram 41c is connected to the piston body 21 in the axial direction Z. The ram 41c is provided on the withdrawal side Z2 relative to the piston body 21. Also, for example, the ram 41c may be formed integrally with the piston body 21. The ram 41c moves integrally with the piston body 21. For example, the ram 41c includes a ram base 41c1 and a ram columnar portion 41c2. The ram base 41c1 is a portion of the ram 41c on the withdrawal side Z2. The ram base 41c1 is disposed inside the cylinder body 41a. The ram base 41c1 divides (partitions) the interior of the cylinder body 41a into a head side chamber 41a1 and a ram side chamber 41a2. The ram pillar portion 41c2 is provided to extend from the ram base portion 41c1 toward the insertion side Z1. The ram pillar portion 41c2 protrudes from the inside to the outside of the cylinder body 41a toward the insertion side Z1. The ram pillar portion 41c2 is pillar-shaped (for example, cylindrical) extending in the axial direction Z.

[0032] The ram seal 41d is a member (packing) that seals the gap between the ram 41c and the cylinder body 41a. The ram seal 41d prevents the flow of hydraulic fluid between the head side chamber 41a1 and the ram side chamber 41a2. The ram seal 41d is provided on the ram 41c, and more specifically, on the radially outer portion (e.g., outer peripheral surface) of the ram base 41c1. The ram seal 41d contacts the cylinder body 41a, and more specifically, on the radially inner surface (e.g., inner peripheral surface) of the cylinder body 41a. For example, the ram seal 41d is made of an elastic member (e.g., rubber, resin, etc.). The ram seal 41d is annular (e.g., circular). The ram seal 41d moves in the axial direction Z integrally with the ram 41c. The ram seal 41d slides relative to the cylinder body 41a.

[0033] The fluid pressure pipe 43 is a pipe through which the working fluid passes. The fluid pressure pipe 43 supplies and discharges the working fluid between the fluid pressure control unit 47 and the fluid pressure cylinder 41 (more specifically, the head side chamber 41a1). Note that a pipe (not shown) may be provided to supply and discharge the working fluid between the fluid pressure control unit 47 and the ram side chamber 41a2.

[0034] The fluid pressure detection unit 45 detects the pressure of the fluid supplied to the fluid pressure cylinder 41. More specifically, the fluid pressure detection unit 45 detects the pressure (fluid pressure) of the working fluid supplied to the fluid pressure cylinder 41 when the piston body 21 moves to the insertion side Z1. The fluid pressure detection unit 45 outputs (transmits) the detected value (e.g., an electrical signal) to the fluid pressure control unit 47. The fluid pressure detection unit 45 is, for example, a pressure transmitter. The fluid pressure detection unit 45 may detect the fluid pressure inside the cylinder body 41a (more specifically, inside the head side chamber 41a1), or may detect a fluid pressure (e.g., the fluid pressure inside the fluid pressure piping 43) that is the same as or approximately the same as this fluid pressure.

[0035] The fluid pressure control unit 47 controls the operation of the fluid pressure cylinder 41. The fluid pressure control unit 47 controls the operation of the piston body 21 by controlling the operation of the fluid pressure cylinder 41. The fluid pressure control unit 47 controls the operation of the fluid pressure cylinder 41 based on the fluid pressure detected by the fluid pressure detection unit 45. For example, the fluid pressure control unit 47 is a device (fluid pressure unit) that includes multiple fluid devices. For example, the fluid pressure control unit 47 includes a pump, a valve (e.g., a relief mechanism), and a control device that controls the pump and the valve based on a signal input to the fluid pressure control unit 47.

[0036] The piston position information detection unit 51 detects position information (details will be described later) of the piston body 21 relative to the pressure vessel 10. The piston position information detection unit 51 detects position information of the piston body 21 in the axial direction Z. As will be described later, the piston body 21 performs a slight reciprocating motion (reciprocating movement) during the holding stroke. The piston position information detection unit 51 is configured to be able to grasp the slight movement of the reciprocating motion of the piston body 21. For example, the piston position information detection unit 51 detects the position information in a non-contact manner. For example, the piston position information detection unit 51 detects the position information using electromagnetic waves. For example, the piston position information detection unit 51 may detect the position information using light (e.g., laser light) or may detect the position information using radio waves. The piston position information detection unit 51 may detect the position information of the piston body 21 by contacting the piston body 21 or the ram 41c (a contact-type sensor may be used).

[0037] When piston position information detection unit 51 detects position information by electromagnetic waves (for example, light), piston position information detection unit 51 includes sensor main body 51a and reflector 51b.

[0038] The sensor main body 51a emits and receives (e.g., receives light) electromagnetic waves. The sensor main body 51a emits electromagnetic waves in the axial direction Z. The sensor main body 51a is provided on the pressure vessel 10 or the piston body 21. In the example shown in FIG. 1, the sensor main body 51a is provided on (e.g., attached to) the pressure vessel 10. For example, the sensor main body 51a may be provided on a portion (e.g., an end) of the pressure vessel body 11 on the withdrawal side Z2. For example, the sensor main body 51a may be provided on a radially outer portion of the pressure vessel body 11 (not shown).

[0039] The reflecting portion 51b has a surface (e.g., a flat surface) that reflects the electromagnetic waves emitted from the sensor main body 51a. The reflecting portion 51b is disposed at a position facing the sensor main body 51a in the axial direction Z. The reflecting portion 51b is provided on the pressure vessel 10 and the piston main body 21 on the side opposite to the side on which the sensor main body 51a is provided. In the example shown in FIG. 1, the reflecting portion 51b is provided on the piston main body 21 (e.g., the piston main body base 21b). For example, the reflecting portion 51b is separate from the piston main body 21. For example, the reflecting portion 51b may be plate-shaped (a reflecting plate) or may not be plate-shaped (e.g., a block shape). Furthermore, for example, the reflecting portion 51b may be provided integrally with the piston main body 21. For example, the reflecting portion 51b may be part of the piston main body base 21b. The reflecting portion 51b may be provided on the ram 41c (or may be provided on the piston main body 21 via the ram 41c). Alternatively, the sensor main body 51a may be provided in the piston main body 21, and the reflecting part 51b may be provided in the pressure vessel 10. For example, the sensor main body 51a detects the distance Dz in the axial direction Z from the sensor main body 51a to the reflecting part 51b.

[0040] The piston axial force information detection unit 53 detects piston axial force information. The piston axial force information is information about the axial force in the axial direction Z (the force applied in the axial direction Z) that is applied to the piston main body 21 (referred to as the "piston axial force"). The piston axial force is the sum of the force due to the internal pressure of the container that is applied to the piston main body 21 and the piston seal friction force. Strictly speaking, the piston axial force is affected by forces other than the internal pressure of the container and the piston seal friction force, such as the weight of the piston main body 21. However, the influence of forces other than the internal pressure of the container and the piston seal friction force on the piston axial force is so small that it can be ignored.

[0041] The reason why the piston axial force information is detected by the piston axial force information detection unit 53 is as follows: In the pressurizing device 1, it is important to control the internal vessel pressure so that it approaches the set pressure (target pressure) as closely as possible. However, during actual operation of the pressurizing device 1 (described later), it is impossible or difficult to directly detect the internal vessel pressure. An example of the reason is as follows: [When the internal vessel pressure is detected outside the vessel] For example, a pressure derivation member De (e.g., a pipe) is provided to deliver a high-pressure (e.g., 1000 MPa class) pressure medium O1 from the inside of the pressure vessel 10 to the outside. Then, a pressure detection member 80 (described later) detects the pressure delivered by the pressure derivation member De (or a pressure obtained by reducing this pressure) outside the pressure vessel 10. In this case, the pressure derivation member De has a short lifespan and may not be able to withstand long-term actual operation. [When the internal vessel pressure is detected inside the vessel] For example, a pressure detection member 80 is disposed inside the pressure vessel 10 and detects the pressure of the pressure medium O1. As a result, there is a risk that the pressure detection member 80 will not be able to withstand long periods of actual operation. Therefore, it is impossible or difficult to directly detect the internal pressure of the container during actual operation of the pressurizing device 1 (described later). Therefore, during actual operation of the pressurizing device 1, the piston axial force information detection unit 53 detects piston axial force information that can be converted into the internal pressure of the container. Then, the internal pressure of the container is controlled based on the piston axial force information and the like (details of the control will be described later).

[0042] The piston axial force information detected by the piston axial force information detection unit 53 may be a value of the piston axial force. The piston axial force information may also be information related to (correlated with) the piston axial force. For example, the piston axial force information may include information convertible to the piston axial force, or may include information convertible from the piston axial force. Specifically, for example, the piston axial force information may include the amount of strain of the piston body 21 in the axial direction Z. The axial force of the piston body 21 can be calculated from the amount of strain of the piston body 21 in the axial direction Z using an equation of material mechanics. Furthermore, for example, the piston axial force information may include information related to the force with which the drive device 40 presses the piston body 21 toward the insertion side Z1 (see the modified example described later). The piston axial force information may also include a pressure (converted pressure) obtained by converting the piston axial force into internal pressure of the container. For example, when the piston axial force information includes the amount of strain of the piston body 21 in the axial direction Z, the piston axial force information detection unit 53 includes a strain gauge 53a.

[0043] The strain gauge 53a detects strain in the axial direction Z of the piston body 21. The strain gauge 53a is attached (for example, adhered) to the piston body 21. More specifically, the strain gauge 53a is attached to the radially outer surface (for example, the outer peripheral surface) of the piston body columnar portion 21a.

[0044] The controller 60 is a device (computer) that inputs and outputs signals, stores information, and performs calculations (calculation, determination, etc.). For example, the controller 60 may be a personal computer or a programmable controller. For example, the functions of the controller 60 are realized by a calculation unit executing a program stored in a storage unit of the controller 60. As shown in FIG. 2, the controller 60 includes a piston position information calculation unit 61, a friction information storage unit 62, a set pressure setting unit 63, a pressure calculation unit 64, and a drive control unit 65. In the following, components of the pressurizing device 1 other than the controller 60 will be described with reference to FIG. 1, and the controller 60 and its components will be described with reference to FIG. 2.

[0045] The piston position information calculation unit 61 performs calculations related to the position information of the piston body 21 from the detection value of the piston position information detection unit 51. For example, the position information is used for selecting friction information, which will be described later. The position information may include information (value, coordinates, etc.) on the position of the piston body 21. The position information may include information on the movement (change in position) of the piston body 21. The position information may include information indicating whether the piston body 21 is moving. The position information may include information on the direction of movement of the piston body 21 (whether to the insertion side Z1 or the withdrawal side Z2). The position information may include information on the movement speed (magnitude of the movement speed) of the piston body 21.

[0046] The friction information storage unit 62 stores friction information, which is information relating to piston seal frictional force (details will be described later).

[0047] The set pressure setting unit 63 sets the set pressure inside the pressure vessel 10. The set pressure is a target pressure inside the pressure vessel 10 (target internal vessel pressure) (details will be described later). For example, the set pressure setting unit 63 may set the set pressure in response to the operation of the controller 60, or may set the set pressure based on information input to the controller 60 from outside the controller 60.

[0048] The pressure calculation unit 64 (pressure calculator) calculates (estimates) the pressure inside the container based on the piston axial force information detected by the piston axial force information detection unit 53 and the friction information stored in the friction information storage unit 62 (details will be described later).

[0049] The drive control unit 65 controls the drive device 40. The drive control unit 65 controls the drive device 40 based on the piston axial force information detected by the piston axial force information detection unit 53 and the friction information stored in the friction information storage unit 62 (details will be described later).

[0050] The pressure notification unit 70 (see FIG. 1) notifies information related to the pressure inside the container. For example, the pressure notification unit 70 notifies the pressure calculation unit 64 of the calculated value of the pressure inside the container. The notification by the pressure notification unit 70 may be a display (the pressure notification unit 70 may be, for example, a pressure indicator). The notification by the pressure notification unit 70 may also be an audio notification.

[0051] The pressure sensing member 80 (pressure measurement element) (see FIG. 1) detects the pressure inside the vessel. The pressure sensing member 80 is used to directly detect the pressure inside the vessel during preliminary measurements, which will be described later. The pressure sensing member 80 is provided so as to be removable from the pressure vessel 10. The pressure sensing member 80 may be arranged inside the pressure vessel 10 and attached to the pressure vessel 10 inside the pressure vessel 10 (details will be described later). The pressure sensing member 80 may also be arranged outside the pressure vessel 10 and attached to the pressure vessel 10 via a pressure lead-out member De.

[0052] The pressure sensing member 80 is, for example, a member for which the relationship between the pressure around the pressure sensing member 80 and its electrical resistance is known in advance. The pressure sensing member 80 may also be a member for which the relationship between temperature and electrical resistance is known in advance. For example, the pressure sensing member 80 is a member for which the electrical resistance of the pressure sensing member 80 is proportional or approximately proportional to the pressure around the pressure sensing member 80. Specifically, the pressure sensing member 80 may be made of a copper alloy containing 12 to 18 mass% manganese and 1.5 to 4 mass% nickel. The pressure sensing member 80 does not need to be a member for which the electrical resistance of the pressure sensing member 80 is proportional or approximately proportional to the pressure around the pressure sensing member 80. For example, the pressure sensing member 80 may be an alloy (constantan) containing 45 to 50 mass% nickel and 50 to 55 mass% copper (the total proportion of nickel and copper is 100 mass% or less). The pressure sensing member 80 does not need to be provided when the pressurizing device 1 is in actual operation (described later).

[0053] (Activated) The pressurizing device 1 is configured to operate as follows. A preliminary measurement and an actual operation (normal operation) are performed in the pressurizing device 1. The components of the pressurizing device 1 other than the controller 60 will be described with reference to FIG. 1, and the controller 60 and the components of the controller 60 will be described with reference to FIG. 2.

[0054] (Pre-measurement) The preliminary measurement is a measurement (operation of the pressurizing device 1) for acquiring friction information to be stored in the friction information storage unit 62. When the preliminary measurement is performed, the pressurizing device 1 is a friction information acquisition device for acquiring friction information. The preliminary measurement is performed before (in advance of) the actual operation. In the preliminary measurement, a pressure detection member 80 is provided inside or outside the pressure vessel 10. In the preliminary measurement, the relationship (preliminary measurement acquisition relationship R (see FIG. 3)) between the piston axial force information detected by the piston axial force information detection unit 53 and the internal pressure (referred to as the "actual pressure inside the vessel") detected by the pressure detection member 80 is measured.

[0055] (Scope of acquisition of pre-measurement acquisition relationship R) The pre-measured and acquired relationship R shown in FIG. 3 is acquired over the range of piston axial force information during actual operation (used axial force range). The pre-measured and acquired relationship R is acquired so as to include the entire used axial force range. For example, if the piston axial force information is a converted pressure (described later) converted from the axial force of the piston body 21 to a container internal pressure, the pre-measured and acquired relationship R is acquired over the range of converted pressures during actual operation (used converted pressure range). The pre-measured and acquired relationship R is acquired over the range of actual container internal pressures during actual operation (used actual container internal pressure range). The pre-measured and acquired relationship R is acquired so as to include the entire used actual container internal pressure range.

[0056] (Whether or not the piston body 21 moved in advance and the direction of movement) In the preliminary measurement, the preliminary measurement-obtained relationship R is obtained when the piston body 21 moves in the axial direction Z relative to the pressure vessel 10. It is preferable that the preliminary measurement-obtained relationship R is obtained for each direction of movement of the piston body 21 relative to the pressure vessel 10. More specifically, it is preferable to obtain the "relationship Ra when moving on the insertion side Z1" described below and the "relationship Rc when moving on the withdrawal side Z2" described below. In the preliminary measurement, the "relationship Rb when stationary" which is the preliminary measurement-obtained relationship R when the piston body 21 is stationary relative to the pressure vessel 10 may be obtained.

[0057] (Movement speed of piston body 21 measured in advance) In the preliminary measurement, the preliminary measurement-obtained relationship R may be obtained for one pattern of the movement speed of the piston body 21. In this case, it is preferable that the movement speed of the "one pattern" is the same as or approximately the same as the movement speed of the piston body 21 during actual operation. In the preliminary measurement, the preliminary measurement-obtained relationship R may be obtained for each of a plurality of patterns of the movement speed of the piston body 21. In this case, a plurality of patterns of a graph such as that shown in FIG. 3 are obtained.

[0058] (Specific example of pre-measurement acquisition relationship R) A specific example of the pre-measurement-acquired relationship R (the relationship between piston axial force information and actual pressure inside the container) will be described. In the example shown in FIG. 3, the piston axial force information is a converted pressure. The converted pressure is calculated, for example, as follows: The axial force of the piston body 21 is calculated from the strain amount of the piston body 21 obtained from the strain gauge 53a. As described above, the axial force of the piston body 21 is the sum of the piston seal friction force and the force due to the pressure received by the piston body 21. The converted pressure is the value obtained by dividing the axial force of the piston body 21 by the pressure-receiving area of ​​the piston body 21. The "pressure-receiving area" is the area of ​​the portion of the piston body 21 that receives pressure in the axial direction Z from the pressurized object O (pressure medium O1). Specifically, for example, the pressure-receiving area is the area of ​​the piston body columnar portion 21a when viewed from the insertion side Z1.

[0059] The pre-measurement acquired relationship R includes a relationship Ra during movement on the insertion side Z1, a relationship Rb during stationary state, and a relationship Rc during movement on the withdrawal side Z2. In the example shown in FIG. 3, the pre-measurement acquired relationship R is obtained in the following order (process): relationship Ra during movement on the insertion side Z1, relationship Rb during stationary state, and relationship Rc during movement on the withdrawal side Z2. Note that the pre-measurement may be started with the pressure vessel 10 in a pre-pressurized state, and the pre-measurement acquired relationship R may be obtained in the following order: relationship Rc during movement on the withdrawal side Z2, and relationship Ra during movement on the insertion side Z1. The following mainly describes the case where the piston axial force information is a converted pressure.

[0060] A discrepancy occurs between the converted pressure and the actual pressure inside the container. The amount of this discrepancy is referred to as the discrepancy amount α. The discrepancy amount α is the amount of discrepancy between the converted pressure and the 100% efficiency line L. The 100% efficiency line L is a linear graph showing the relationship between the actual pressure inside the container and the converted pressure, assuming that the actual pressure inside the container and the converted pressure are the same. The discrepancy amount α is caused by the piston seal friction force. Specifically, the discrepancy amount α is the value obtained by dividing the piston seal friction force by the pressure-receiving area of ​​the piston body 21.

[0061] The relationship Ra during movement of the insertion side Z1 is the pre-measured relationship R when the piston body 21 moves to the insertion side Z1 relative to the pressure vessel 10 (pressurization stroke (details of each process will be described later)). In the relationship Ra during movement of the insertion side Z1, the greater the actual pressure, the greater the converted pressure. The deviation amount α in the relationship Ra during movement of the insertion side Z1 is defined as deviation amount αa. The deviation amount αa becomes larger as the converted pressure (the greater the actual pressure). The deviation amount αa is the value obtained by subtracting the actual pressure in the vessel from the converted pressure. Note that when the piston body 21 starts to move to the insertion side Z1 (at the start of the pressurization stroke), the piston body 21 does not move to the insertion side Z1, and the actual pressure in the vessel does not increase, until it is pushed against the insertion side Z1 with a force that exceeds the piston seal friction force (see the lower left part of the graph).

[0062] The relationship Rb at rest is the relationship R obtained by pre-measurement when the piston body 21 is stationary (holding stroke) relative to the pressure vessel 10. In the relationship Rb at rest, the actual pressure is maintained at a constant (or approximately constant) pressure P2. Note that the relationship Rb at rest does not have to be obtained in pre-measurement.

[0063] The relationship Rc during movement on the withdrawal side Z2 is the pre-measured relationship R when the piston body 21 moves to the withdrawal side Z2 relative to the pressure vessel 10 (decompression process). In the relationship Rc during movement on the withdrawal side Z2, the converted pressure decreases as the actual pressure in the vessel decreases. The deviation amount α in the relationship Rc during movement on the withdrawal side Z2 is referred to as the deviation amount αc. The deviation amount αc increases as the converted pressure increases (as the actual pressure increases). The deviation amount αc is the value obtained by subtracting the converted pressure from the actual pressure in the vessel. In the example shown in Figure 3, the deviation amount αc when the actual pressure in the vessel is a certain pressure P1 is larger than the deviation amount αa when the actual pressure in the vessel is this pressure P1. Note that when the actual pressure in the vessel is a certain pressure P1, the deviation amount αc may be smaller than the deviation amount αa or may be equal to the deviation amount αa.

[0064] The graphs of the relationship Ra during movement on the insertion side Z1, the relationship Rb when stationary, and the relationship Rc during movement on the withdrawal side Z2 are linear in the example shown in Figure 3, but they are not necessarily linear and may be curved. For example, there are cases where the graph of at least one of the relationship Ra during movement on the insertion side Z1 and the relationship Rc during movement on the withdrawal side Z2 bends significantly near the holding stroke.

[0065] (Examples of advance measurement) In the preliminary measurement, the actual pressure inside the vessel is detected by the pressure sensing member 80. The pressure sensing member 80 may be disposed inside the pressure vessel 10 or outside the pressure vessel 10.

[0066] A specific example of a case where the pressure sensing member 80 detects the actual pressure inside the pressure vessel 10 outside (a case where friction information is acquired with the pressure sensing member 80 disposed outside the pressure vessel 10) is as follows: A pressure derivation member De (e.g., a pipe) is provided to deliver a pressure medium O1 at a high pressure (e.g., 1000 MPa class) from the inside of the pressure vessel 10 to the outside. For example, the pressure derivation member De is provided in a hole in the pressure vessel 10 (more specifically, the pressure vessel lid 13). The pressure sensing member 80 then detects the pressure delivered by the pressure derivation member De (or a pressure resulting from a reduction of this pressure) outside the pressure vessel 10. In this example, a high pressure (e.g., 1000 MPa class) is applied to the pressure derivation member De. The pressure derivation member De may not be able to withstand long periods of actual operation. On the other hand, the pressure derivation member De is (or is made of a member that can withstand) preliminary measurements (e.g., several tens of pressurizations) that are shorter than the actual operation. It is preferable that the pressure lead-out member De is used in the preliminary measurement and then removed from the pressure vessel 10 when the pressure vessel 10 is used for actual operation.

[0067] A specific example of a case where the pressure sensing element 80 detects the actual pressure inside the pressure vessel 10 (a case where friction information is acquired while the pressure sensing element 80 is disposed inside the pressure vessel 10) is as follows: The pressure sensing element 80 is disposed inside the pressure vessel 10 so that it can be removed from the interior of the pressure vessel 10. Wiring (not shown) is connected to the pressure sensing element 80. This wiring is, for example, wiring for measuring the electrical resistance of the pressure sensing element 80. This wiring is connected to the pressure sensing element 80 and led to the outside of the pressure vessel 10, for example, via a feedthrough. The pressure sensing element 80 then detects the pressure inside the pressure vessel 10. After being used for preliminary measurements, the pressure sensing element 80 is preferably removed from the pressure vessel 10 when the pressure vessel 10 is in actual operation. During actual operation, the temperature inside the pressure vessel 10 may exceed the heat resistance of the pressure sensing element 80, which may affect the pressure detection performance of the pressure sensing element 80, resulting in a decrease in the accuracy of detecting the actual pressure inside the vessel or making detection impossible.

[0068] (Other conditions of pre-measurement) It is preferable to make the conditions that affect the friction information as similar as possible between the preliminary measurement and the actual operation. For example, it is preferable to make the temperature of the piston seal 23 as similar as possible between the preliminary measurement and the actual operation. Specifically, for example, if the inside of the insulating layer 33 reaches 2000°C during actual operation, the inside of the pressure vessel 10 and the outside of the insulating layer 33 may reach approximately 100°C, and the piston seal 23 may also reach approximately 100°C. In this case, it is preferable to set the temperature of the piston seal 23 to 100°C or approximately 100°C during the preliminary measurement. If the impact on the friction information is small, if the piston seal 23 reaches 100°C or approximately 20°C during actual operation, the piston seal 23 may be set to room temperature (approximately 20°C) during the preliminary measurement. Note that the above temperature values ​​are merely examples, and the above temperatures can be set to various values. Conditions that have no or almost no impact on the friction information do not need to be the same between the preliminary measurement and the actual operation. For example, it is not necessary to place the pressure vessel internals 30 or the workpiece O3 inside the pressure vessel 10 during the preliminary measurement.

[0069] (Friction information stored in the friction information storage unit 62) The friction information stored in the friction information storage unit 62 includes information about the piston seal friction force when the piston body 21 moves relative to the pressure vessel 10. The friction information is acquired (set) based on the pre-measurement acquired relationship R obtained by pre-measurement. The friction information may be the pre-measurement acquired relationship R, or may be information calculated (derived) from the pre-measurement acquired relationship R.

[0070] For example, the friction information is the relationship (e.g., a graph, a map, etc.) between piston axial force information and the magnitude of a value related to piston seal friction force. The friction information may also be the relationship between piston axial force information and a deviation amount α. In this case, the deviation amount α is also referred to as "pressure correction value data." The friction information may also be the relationship between piston axial force information and a value obtained by adding or subtracting the deviation amount α from the converted pressure (an estimated value of the pressure inside the container). The friction information may also be the relationship between piston axial force information and the magnitude of piston seal friction force.

[0071] The friction information storage unit 62 preferably stores friction information for each direction of movement of the piston body 21. In this case, the friction information storage unit 62 stores friction information when the piston body 21 moves toward the insertion side Z1 relative to the pressure vessel 10. This friction information is set based on the relationship Ra during movement toward the insertion side Z1. The friction information storage unit 62 also stores friction information when the piston body 21 moves toward the withdrawal side Z2 relative to the pressure vessel 10. This friction information is set based on the relationship Rc during movement toward the withdrawal side Z2. Note that the friction information storage unit 62 does not have to store (but may store) friction information based on the relationship Rb when stationary.

[0072] The friction information storage unit 62 preferably stores friction information for each of a plurality of patterns of movement speed of the piston body 21. More specifically, the friction information storage unit 62 preferably stores friction information for each of a plurality of patterns of movement speed of the piston body 21 relative to the pressure vessel 10.

[0073] (Calibration of friction information) The friction information may be calibrated (corrected or updated) when necessary. For example, after an actual operation has been performed, preliminary measurements may be performed again as necessary to calibrate the friction information. In this case, the pressurizing device 1 can maintain highly accurate control of the internal pressure of the container.

[0074] (Actual driving) The actual operation is the operation of the pressurizing device 1 that controls the pressure inside the container based on the friction information. When the pressurizing device 1 is a device that processes the processed item O3, the actual operation is the operation for processing the processed item O3. When the pressurizing device 1 is a device that measures the state of the object O to be pressurized, the actual operation is the operation for measuring the state of the object O to be pressurized.

[0075] (Outline of actual operation) An outline of the procedure for actual operation is as follows, for example. A set pressure (target pressure) is set in the set pressure setting unit 63, and a set pressure pattern, for example, is set (see FIG. 4). The set pattern is information regarding the relationship between the set pressure and time. The piston 20 is inserted into the pressure vessel 10. An object to be pressurized O (e.g., a pressure medium O1 and a processing object O3) is placed in the pressure vessel 10. The heating device 35 starts heating (is turned on) the inside of the pressure vessel 10 before or simultaneously with the start of the pressurization step. Then, the pressurizing device 1 performs a pressurization step, a holding step, and a depressurization step according to the set pattern (see FIG. 4). The pressurization step may be performed in one stage or multiple stages (the same applies to the depressurization step). In the example shown in FIG. 4, the pressurizing step is performed in two stages and the depressurization step is performed in one stage. In the example shown in FIG. 4, the pressurizing device 1 performs each step in the following order: pressurization step, holding step, pressurization step, holding step, and depressurization step.

[0076] (Overview of vessel internal pressure control) The drive control unit 65 controls the drive unit 40 based on the piston axial force information and friction information during each of the pressurization stroke, the pressure retention stroke, and the depressurization stroke. By controlling the drive unit 40, the drive control unit 65 controls the movement of the piston body 21 in the axial direction Z, thereby controlling the internal vessel pressure. Because the internal vessel pressure is controlled based on the piston axial force information and friction information, there is no need to directly detect the internal vessel pressure (by the pressure detection member 80). Therefore, the internal vessel pressure can be controlled with high accuracy without outputting the pressure inside the pressure vessel 10 to the outside of the pressure vessel 10 or providing a pressure detection member 80 inside the pressure vessel 10.

[0077] (pressurization stroke) The drive control unit 65 controls the drive device 40 so that the piston body 21 moves to the insertion side Z1 during the pressurizing stroke. The direction of movement of the piston body 21 during the pressurizing stroke is limited to the insertion side Z1 (limited to one direction). Note that the piston body 21 may reciprocate during the pressurizing stroke (described later) (see FIG. 7). During the pressurizing stroke, the pressure inside the container increases over time. Changes in the pressure inside the container during the pressurizing stroke are almost exclusively due to the movement of the piston body 21 (the same applies to the depressurizing stroke). Strictly speaking, during the pressurizing stroke, the pressure inside the container changes due to temperature changes inside the pressure vessel 10, for example, due to heat from the heating device 35. However, changes in the pressure inside the container due to factors other than the movement of the piston body 21 are negligibly small (ignoring these changes has no or almost no effect on the control of the pressure inside the container) (the same applies to the depressurizing stroke). The control of the drive device 40 by the drive control section 65 during the pressurizing stroke is similar to the control of the drive device 40 during the movement of the piston body 21 toward the insertion side Z1 during the reciprocating motion during the holding stroke described later.

[0078] (Decompression process) The drive control unit 65 controls the drive unit 40 so that the piston body 21 moves toward the withdrawal side Z2 during the decompression stroke. The direction of movement of the piston body 21 during the decompression stroke is limited to the withdrawal side Z2 (limited to one direction). Note that the piston body 21 may reciprocate during the decompression stroke. During the decompression stroke, the pressure inside the container decreases over time. The control of the drive unit 40 by the drive control unit 65 during the decompression stroke is similar to the control of the drive unit 40 when the piston body 21 moves toward the withdrawal side Z2 during the reciprocating motion of the piston body 21 during the holding stroke described below.

[0079] (holding process) The drive control unit 65 controls the drive device 40 so as to maintain the pressure inside the container at a substantially constant level during the holding stroke. The drive control unit 65 causes the piston body 21 to reciprocate at a substantially constant position during the holding stroke (the reciprocating movement will be described in detail later).

[0080] For example, if the pressurizing device 1 is an isostatic pressurizing device for treating the object O3, the most critical step among the pressurizing step, holding step, and depressurizing step is the holding step. During the holding step, it is important to maintain the object O3 at a target temperature and to maintain the pressure applied to the object O3 at a set pressure. The goal of the holding step is to achieve a uniform temperature distribution within the object O3 at a target temperature (e.g., 2000°C). To achieve this, the goal of the holding step is to maintain the temperature distribution within the pressure vessel 10 at a steady state (e.g., a state in which a constant amount of heat is continuously released from the inside of the insulating layer 33 to the outside). However, the temperature distribution within the pressure vessel 10 does not reach the target state immediately after the holding step begins. The holding step is performed for a long period of time (e.g., several hours) to ensure that the temperature distribution within the pressure vessel 10 reaches the target state. Even if the pressurizing device 1 is not a device for treating the object O3, maintaining the interior of the pressure vessel 10 at a set pressure and target temperature may be important.

[0081] (Problem when the piston body 21 is stationary) It is difficult to accurately control the pressure inside the vessel when the piston body 21 is stationary relative to the pressure vessel 10. The reasons for this include the difficulty in estimating the pressure inside the vessel (see [Example Problem 1] below) and the difficulty in having the piston body 21 follow changes in the pressure inside the vessel (see [Example Problem 2] below).

[0082] [Example Problem 1] As shown in Figure 3, in the stationary relationship Rb, which can be obtained by prior measurement, the piston body 21 remains in a fixed position, and the actual pressure inside the vessel is a constant pressure P2. However, during actual operation, even if the position of the piston body 21 is fixed, the actual pressure inside the vessel does not remain constant but changes (fluctuations). For example, the temperature inside the pressure vessel 10 inevitably changes over time and in distribution. For example, when the heating device 35 heats the object to be pressurized O, the temperature distribution inside the pressure vessel 10 changes. Furthermore, at this time, the average temperature inside the pressure vessel 10 increases over time. When the temperature inside the pressure vessel 10 changes, the internal pressure of the vessel also changes according to Boyle's law. Therefore, even if the position of the piston body 21 is fixed, the actual pressure inside the vessel will not be constant.

[0083] As is clear from FIG. 3, in the stationary relationship Rb, the converted pressure is not determined to be a single value for a given actual container pressure value (e.g., pressure P2). Specifically, during the holding stroke, it is unclear whether the piston axial force information value (converted pressure) fluctuates (higher, lower) or remains the same relative to the 100% efficiency line L. This is equivalent to the fact that even if the converted pressure is determined to be a single value, the actual container pressure is not determined to be a single value. Therefore, it is difficult to accurately calculate (estimate) the container pressure from the converted pressure. As a result, it is difficult to accurately control the container pressure when the piston body 21 is stationary relative to the pressure vessel 10.

[0084] [Example Problem 2] Generally, static friction is greater than kinetic friction. Therefore, when the piston body 21 is stationary relative to the pressure vessel 10, it tends to remain stationary relative to the pressure vessel 10 even if the internal pressure of the vessel changes. More specifically, if the temperature inside the pressure vessel 10 rises, the internal pressure of the vessel will tend to increase according to Boyle's law. If the piston seal friction is smaller than the force due to the internal pressure of the vessel that the piston body 21 receives, the piston body 21 will move toward the draw-out side Z2, the internal pressure of the vessel will decrease, and the internal pressure of the vessel will approach the set pressure. However, if the piston seal friction is greater than the force due to the internal pressure that the piston body 21 receives, the piston body 21 will not move toward the draw-out side Z2 even if the internal temperature of the pressure vessel 10 rises. This will increase the internal pressure of the vessel, causing it to deviate from the set pressure. Similarly, if the temperature inside the pressure vessel 10 decreases, the internal pressure of the vessel will decrease, causing it to deviate from the set pressure. As a result, when the piston body 21 is stationary relative to the pressure vessel 10, it is difficult to control the pressure inside the vessel with high precision.

[0085] (Outline of reciprocating motion) Therefore, the pressurizing device 1 of this embodiment is configured to operate as follows during the holding stroke. The drive control unit 65 controls the drive device 40 so that the piston body 21 moves back and forth (moves back and forth in the axial direction Z) relative to the pressure vessel 10. The drive device 40 causes the piston body 21 to move back and forth relative to the pressure vessel 10. The piston body 21 moves back and forth relative to the pressure vessel 10. The piston body 21 moves back and forth in the axial direction Z in small increments (fine movements).

[0086] During the holding stroke, the piston body 21 reciprocates relative to the pressure vessel 10, so that the pressure inside the vessel can be controlled with high precision. The reason for this is as follows, for example.

[0087] [Reason Example 1] Because the piston body 21 reciprocates relative to the pressure vessel 10, friction information when the piston body 21 moves in the axial direction Z can be used. With friction information when the piston body 21 moves in the axial direction Z, if the value of the piston axial force information is determined to be one, the pressure inside the vessel is determined to be one value (see Figure 3). Therefore, the pressure inside the vessel can be calculated (estimated) with high precision. As a result, the pressure inside the vessel can be controlled with high precision.

[0088] [Reason 2] Furthermore, because the piston body 21 reciprocates relative to the pressure vessel 10, the piston seal friction force is a kinetic friction force that is smaller than the static friction force. Therefore, the position of the piston body 21 can easily follow changes in the vessel internal pressure due to temperature changes within the pressure vessel 10. For example, when the temperature inside the pressure vessel 10 rises and the vessel internal pressure tends to increase, the piston body 21 (e.g., the center position of the reciprocating motion of the piston body 21) tends to move toward the withdrawal side Z2. Furthermore, when the temperature inside the pressure vessel 10 drops and the vessel internal pressure tends to decrease, the piston body 21 (e.g., the center position of the reciprocating motion of the piston body 21) tends to move toward the insertion side Z1. Therefore, because the position of the piston body 21 easily follows changes in the vessel internal pressure, the vessel internal pressure can be brought closer to the set pressure. As a result, the vessel internal pressure can be controlled with high precision.

[0089] (Details of reciprocating motion) As described above, the drive control unit 65 controls the drive device 40 based on the piston axial force information and friction information. Details of this control are as follows.

[0090] (Detection of the piston body 21) The piston position information detection unit 51 detects piston axial force information (for example, distortion of the piston main body 21) and outputs the detected value to the controller 60. For example, the controller 60 calculates a converted pressure (see FIG. 3) (an example of piston axial force information) from the detected value of the piston axial force information detection unit 53.

[0091] For example, the piston position information detection unit 51 may detect position information of the piston main body 21 and output the detected value to the controller 60. The piston position information calculation unit 61 may determine whether the piston main body 21 is moving or not, based on the detected value of the piston position information detection unit 51. The piston position information detection unit 51 may determine whether the direction of movement of the piston main body 21 is the insertion side Z1 or the withdrawal side Z2, based on the detected value of the piston position information detection unit 51. The piston position information detection unit 51 may calculate the movement speed of the piston main body 21 (more specifically, the magnitude of the movement speed) based on the detected value of the piston position information detection unit 51.

[0092] (Acquisition and selection of friction information) The drive control unit 65 acquires friction information from the friction information storage unit 62. Here, in the preliminary measurement, the pressurizing device 1 performs a pressurizing stroke to obtain the relationship Ra (see FIG. 3) for the movement of the insertion side Z1, and the pressurizing device 1 performs a depressurizing stroke to obtain the relationship Rc (see FIG. 3) for the movement of the withdrawal side Z2. The reciprocating movement of the piston body 21 during the holding stroke in actual operation is a repetition of the movement of the insertion side Z1 of the piston body 21 and the movement of the withdrawal side Z2 of the piston body 21. Therefore, the reciprocating movement of the holding stroke is essentially the same as the pressurizing stroke and depressurizing stroke in terms of the movement of the insertion side Z1 and the withdrawal side Z2 of the piston body 21. Therefore, the friction information acquired from the pressurizing stroke and depressurizing stroke in the preliminary measurement can be used to control the reciprocating movement of the piston body 21 during the holding stroke in actual operation. The friction information used in the holding step may be exactly the same as the friction information used in the pressurizing step (or depressurizing step), or may be corrected friction information used in the pressurizing step (or depressurizing step).

[0093] The drive control unit 65 preferably selects friction information corresponding to the direction of movement of the piston body 21 relative to the pressure vessel 10 (the insertion side Z1 or the withdrawal side Z2). The direction of movement of the piston body 21 is acquired directly or indirectly. [Orientation Acquisition Example 1] For example, the direction of movement of the piston body 21 is preferably detected directly by the piston position information detection unit 51. In this case, it is possible to reliably detect that the piston body 21 is moving in the axial direction Z. [Orientation Acquisition Example 2] The direction of movement of the piston body 21 may also be acquired indirectly. [Orientation Acquisition Example 2a] The direction of movement of the piston body 21 may also be acquired based on information related to the drive of the drive device 40 (e.g., the direction of flow of the working fluid, pressure, etc.). [Orientation Acquisition Example 2b] The direction of movement of the piston body 21 may also be acquired based on a command from the controller 60 to the drive device 40 (e.g., a signal indicating the drive direction of the piston body 21, etc.).

[0094] The drive control unit 65 preferably selects friction information corresponding to the movement speed (movement speed in the axial direction Z) of the piston body 21 relative to the pressure vessel 10. The movement speed of the piston body 21 is acquired directly or indirectly. [Speed ​​Acquisition Example 1] The movement speed of the piston body 21 may be directly detected by the piston position information detection unit 51. In this case, the movement speed of the piston body 21 in the axial direction Z can be reliably detected. For example, the movement speed of the piston body 21 is calculated based on the position of the piston body 21 detected by the piston position information detection unit 51. [Speed ​​Acquisition Example 2] The movement speed of the piston body 21 may be acquired indirectly. [Speed ​​Acquisition Example 2a] The movement speed of the piston body 21 may be acquired based on information related to the drive of the drive device 40 (e.g., the flow rate of the working fluid, etc.). [Speed ​​Acquisition Example 2b] The movement speed of the piston body 21 may be acquired based on a command from the controller 60 to the drive device 40 (e.g., a signal indicating the drive speed of the piston body 21, etc.).

[0095] When the moving speed of the reciprocating motion of the piston body 21 is constant (except when the direction of movement is switched and the time therearound), there is no need to select friction information corresponding to the moving speed of the piston body 21. Furthermore, in the preliminary measurement, there is no need to acquire friction information for each of a plurality of patterns of moving speed of the piston body 21. Therefore, the number of preliminary measurements (required number of times) for acquiring friction information can be reduced.

[0096] (Instruction to the driving device 40) The drive control unit 65 sets (calculates) the content of the instruction to be output to the drive unit 40. Based on the piston axial force information and friction information, the drive control unit 65 sets the content of the instruction to the drive unit 40 so that the pressure inside the container becomes the set pressure. The content of the instruction to the drive unit 40 is, for example, as follows. [Instruction Example 1] The instruction to the drive unit 40 may be information indicating the position of the piston body 21 in the axial direction Z. [Instruction Example 2] The instruction to the drive unit 40 may be information regarding the force with which the drive unit 40 presses the piston body 21. [Instruction Example 2a] The instruction to the drive unit 40 may be an instruction for the pressure of the working fluid (an instruction for the pressure in the head-side chamber 41a1) with which the drive unit 40 presses the piston body 21. [Instruction Example 2b] The instruction to the drive unit 40 may be a "instructed pressure" (see FIG. 4). The instructed pressure is a target value for the pressure inside the container when it is assumed that there is no piston seal frictional force. In reality, there is piston seal frictional force. Therefore, when the piston body 21 moves toward the insertion side Z1, the command pressure is set to be greater than the set pressure. On the other hand, when the piston body 21 moves toward the withdrawal side Z2, the command pressure is set to be less than the set pressure. Specifically, for example, FIG. 5 shows the relationship between the command pressure, the set pressure, and the actual pressure in the container. In the example shown in FIG. 5, during the holding stroke, command pressures greater than the set pressure and command pressures less than the set pressure are alternately commanded (with the set pressure sandwiched between them). Then, the piston body 21 reciprocates, and the actual pressure in the container repeatedly rises (pressurizes) and falls (depressurizes).

[0097] The drive device 40 is driven in response to instructions output from the drive control unit 65. Specifically, for example, the fluid pressure control unit 47 of the drive device 40 controls the pump, the relief mechanism, and the like in response to instructions output from the drive control unit 65. Then, the fluid pressure cylinder 41 drives the piston body 21 in response to operation of the fluid pressure control unit 47. As a result, the pressure inside the container is controlled to approach the set pressure. The control of the drive device 40 by the drive control unit 65 (control of the pressure inside the container) can be performed by various methods.

[0098] (Example 1 of controlling the internal pressure of a container) For example, the friction information may include the relationship between the converted pressure (an example of piston axial force information) shown in FIG. 3 and pressure correction value data (deviation amount α). In this case, the controller 60 calculates the converted pressure from the detection value of the piston axial force information detection unit 53. The controller 60 also selects friction information corresponding to the direction of movement of the piston 20. The controller 60 determines pressure correction value data (deviation amount α) corresponding to the converted pressure based on the selected friction information. The pressure calculation unit 64 calculates (estimates) the container internal pressure based on the converted pressure and the pressure correction value data (deviation amount α). Specifically, for example, when the piston body 21 moves to the insertion side Z1, the pressure calculation unit 64 calculates the container internal pressure by subtracting the deviation amount αa from the converted pressure. When the piston body 21 moves to the withdrawal side Z2, the pressure calculation unit 64 calculates the container internal pressure by adding the deviation amount αc to the converted pressure. The drive control unit 65 then controls the drive device 40 so that the estimated container internal pressure becomes the set pressure.

[0099] (Example 2 of controlling the internal pressure of a container) The friction information does not need to include the pressure correction value data (deviation amount α) itself, but may include information that can be converted into pressure correction value data. For example, the friction information may include the relationship between the converted pressure and the internal pressure of the container. In this case, the pressure calculation unit 64 calculates (estimates) the internal pressure of the container corresponding to the converted pressure based on the friction information. Then, the drive control unit 65 controls the drive device 40 so that the estimated internal pressure of the container becomes the set pressure.

[0100] (Example 3 of controlling the internal pressure of a container) The friction information does not need to include the converted pressure. For example, the friction information may include the relationship between the strain amount of the piston body 21 (an example of piston axial force information) and the container internal pressure. In this case, the pressure calculation unit 64 calculates (estimates) the container internal pressure corresponding to the strain amount detected by the strain gauge 53a based on the friction information. Then, the drive control unit 65 controls the drive device 40 so that the estimated container internal pressure becomes the set pressure. Note that the above-mentioned method of controlling the container internal pressure is merely a specific example, and various methods of controlling the container internal pressure are possible.

[0101] (Notification of vessel internal pressure) When the pressure calculation unit 64 calculates (estimates) the internal pressure of the container, the pressure notification unit 70 may notify the calculated internal pressure of the container (the same applies to the pressurization step and the depressurization step).

[0102] (Continued back and forth motion) The drive control unit 65 controls the drive device 40 so that the piston body 21 performs reciprocating motion continuously (multiple times). The drive control unit 65 may continue the reciprocating motion throughout the entire holding stroke (from start to finish) (see FIG. 4). The drive control unit 65 continues to move (does not stop) the piston body 21 relative to the pressure vessel 10 except for the moment when the piston body 21 switches its moving direction. Note that the drive control unit 65 may temporarily stop the reciprocating motion of the piston body 21 during the holding stroke. For example, the drive control unit 65 may stop the reciprocating motion of the piston body 21 only for a short period of time that causes only a slight change in the pressure inside the vessel (for example, to an extent that does not affect the processing of the processed product O3).

[0103] (Gradual decrease in reciprocating motion) The drive control unit 65 preferably controls the drive device 40 so that the reciprocating distance (amplitude) of the reciprocating motion of the piston body 21 gradually decreases. Specifically, for example, as shown in Fig. 5, the drive control unit 65 gradually decreases the difference between the command pressure and the set pressure (gradually decreases the amplitude of the set pressure). As a result, the amplitude of the reciprocating motion of the piston body 21 gradually decreases, and the amplitude of the change (rise and fall) in the actual pressure inside the container gradually decreases.

[0104] The reason why it is preferable to gradually decrease the amplitude of the reciprocating motion of the piston body 21 is as follows. For example, immediately after the start of the holding stroke, the internal conditions of the pressure vessel 10 (specifically, the temperature distribution) change significantly. Furthermore, at or immediately after the start of the holding stroke, the unidirectional movement of the piston body 21 stops. At this time, the piston seal friction force changes from kinetic friction force to static friction force. Therefore, immediately after the start of the holding stroke, the accuracy of the friction information may be insufficient. Specifically, for example, the difference between the converted pressure and the actual pressure inside the vessel (actual deviation amount α) shown in FIG. 3 may differ from the pressure correction value data (deviation amount α) set as the friction information. For example, the actual deviation amount α may be larger than the pressure correction value data (deviation amount α) set as the friction information. Therefore, immediately after the start of the holding stroke, the piston body 21 is reciprocated significantly, setting the piston body 21 in a movement state similar to that during the pressurization stroke and depressurization stroke, thereby increasing the accuracy of the friction information. This tends to reduce the difference between the actual deviation amount α and the pressure correction value data (deviation amount α). Thereafter, the pressure inside the container can be made to smoothly approach the set pressure by gradually reducing the amplitude of the reciprocating motion of the piston body 21. Note that the drive control unit 65 may gradually reduce the amplitude of the reciprocating motion of the piston body 21 at a timing other than immediately after the start of the holding stroke (e.g., during the holding stroke).

[0105] The amplitude of the reciprocating motion of the piston body 21 can be gradually reduced (e.g., the amplitude of the command pressure) in various ways (modes) (see FIG. 5 ). [Amplitude Example 1] The amplitude may be gradually reduced from the start to the end of the holding stroke. [Amplitude Example 2] The amplitude may be gradually reduced from the start of the holding stroke until halfway through the holding stroke. For example, the amplitude may be gradually reduced from the start of the holding stroke until the amplitude has decreased to a predetermined magnitude. Thereafter, the amplitude of the reciprocating motion of the piston body 21 may be kept constant. [Amplitude Example 3] The amplitude may decrease proportionally with time, or may decrease in a non-proportional manner. [Amplitude Example 4] The amplitude may be set (changed) according to some condition (e.g., the internal pressure of the container). The amplitude may be set by feedback control. The amplitude may be set by, for example, PID (Proportional Integral Differential) control.

[0106] The period of the reciprocating movement of the piston body 21 (for example, the period of the indicated pressure) can be set in various ways. [Example 1 of Period] This period may be constant or approximately constant. [Example 2 of Period] This period may be changed according to the magnitude of the amplitude. For example, the period may be set longer as the amplitude increases, and shorter as the amplitude decreases. For example, the period may gradually decrease as the amplitude gradually decreases. [Example 3 of Period] This period may be set according to some condition other than the amplitude (for example, the pressure inside the container).

[0107] (Example of the relationship between indicated pressure and internal pressure of the container) As an example of control of the internal pressure of the container by the drive control unit 65, a case will be described in which the internal pressure of the container is controlled in accordance with the pressure commanded by the drive control unit 65 to the drive device 40. As described above, in the example shown in Fig. 5, the drive control unit 65 alternately commands a command pressure higher than the set pressure and a command pressure lower than the set pressure, gradually decreasing the amplitude of the command pressure. As a result, the amplitude of the reciprocating movement of the piston body 21 gradually decreases, and the amplitude of the internal pressure of the container gradually decreases.

[0108] In the example shown in Figure 5, at the start of the holding step (end of the pressurization step), the pressure inside the container matches or nearly matches the set pressure. Then, during the holding step, the pressure inside the container gradually approaches the set pressure while repeatedly increasing and decreasing pressure. In this example, the center of oscillation of the pressure inside the container gradually approaches the set pressure from a value lower than the set pressure.

[0109] FIG. 6 shows another example in which the pressure inside the container is controlled in accordance with the pressure commanded from the drive control unit 65 to the drive device 40. Differences between this example and the example shown in FIG. 5 will be described. In the example shown in FIG. 6, at the start of the holding step, the pressure inside the container is higher than the set pressure. Then, during the holding step, the drive control unit 65 alternately commands a command pressure higher than the set pressure and a command pressure lower than the set pressure, sandwiching the set pressure therebetween, gradually decreasing the amplitude of the command pressure (similar to FIG. 5). In this case, the center of oscillation of the pressure inside the container is the same as or approximately the same as the set pressure.

[0110] FIG. 7 shows another example in which the pressure inside the container is controlled in accordance with the pressure commanded by the drive control unit 65 to the drive device 40. Differences between this example and the example shown in FIG. 6 will be described. In the example shown in FIG. 7, the drive control unit 65 causes the piston body 21 to reciprocate from the stroke before the holding stroke through the holding stroke. Specifically, for example, the drive control unit 65 alternately commands a command pressure higher than the set pressure and a command pressure lower than the set pressure from the stroke before the holding stroke. As a result, the piston body 21 reciprocates from the stroke before the holding stroke through the holding stroke. The "stroke before the holding stroke" may be a pressurization stroke or a depressurization stroke. The drive control unit 65 may or may not gradually decrease the amplitude of the reciprocation of the piston body 21 in the stroke before the holding stroke.

[0111] (Effects of the first invention) The effects of the pressurizing device 1 of this embodiment shown in Figure 1 are as follows. The pressurizing device 1 includes a pressure vessel 10, a piston body 21, a piston seal 23, a piston axial force information detection unit 53, a drive unit 40, a friction information storage unit 62, and a drive control unit 65. The piston body 21 is fitted inside the pressure vessel 10 so as to be movable toward the insertion side Z1 and the withdrawal side Z2 relative to the pressure vessel 10. The piston seal 23 is provided on the piston body 21 and seals the gap between the piston body 21 and the pressure vessel 10. The piston axial force information detection unit 53 detects piston axial force information related to the axial force acting on the piston body 21, which is the axial force in the movement direction of the piston body 21 relative to the pressure vessel 10 (axial direction Z). The drive unit 40 moves the piston body 21 relative to the pressure vessel 10.

[0112] [Configuration 1-1] Friction information storage unit 62 (see FIG. 2) stores friction information related to the frictional force (piston seal frictional force) between piston seal 23 and pressure vessel 10 when piston body 21 moves relative to pressure vessel 10. Drive control unit 65 (see FIG. 2) controls drive device 40 based on piston axial force information detected by piston axial force information detection unit 53 and friction information stored in friction information storage unit 62 (see FIG. 2).

[0113] [Configuration 1-2] The drive control unit 65 (see Figure 2) controls the drive device 40 so that the piston body 21 reciprocates relative to the pressure vessel 10 during a maintenance process in which the pressure inside the pressure vessel 10 is controlled to be kept constant.

[0114] In the above [Configuration 1-1], the drive control unit 65 (see FIG. 2) controls the drive device 40 based on friction information stored in the friction information storage unit 62 (see FIG. 2). This friction information is friction information when the piston body 21 moves relative to the pressure vessel 10. Then, in the above [Configuration 1-2], the drive control unit 65 causes the piston body 21 to reciprocate (i.e., move) relative to the pressure vessel 10 during the holding stroke (see FIG. 5). Therefore, the friction information when the piston body 21 moves relative to the pressure vessel 10 can be applied to the control of the drive device 40 during the holding stroke. Therefore, the pressurizing device 1 can more accurately control the pressure inside the pressure vessel 10 (internal vessel pressure) during the holding stroke compared to when the piston body 21 is stationary relative to the pressure vessel 10 during the holding stroke.

[0115] In the above [Configuration 1-2], the piston body 21 is caused to reciprocate (i.e., move) relative to the pressure vessel 10, so the piston seal friction force is a kinetic friction force that is smaller than the static friction force (except when the direction of movement of the piston body 21 is changed). Therefore, the piston body 21 easily moves in response to temperature changes inside the pressure vessel 10. Therefore, even if the temperature inside the pressure vessel 10 changes during the holding stroke, the pressure inside the vessel is easily maintained. Therefore, the pressurizing device 1 can more accurately control the pressure inside the pressure vessel 10 (vessel internal pressure) during the holding stroke than when the piston body 21 is kept stationary relative to the pressure vessel 10 during the holding stroke.

[0116] (Effects of the second invention) [Configuration 2] The friction information storage unit 62 (see FIG. 2) stores friction information when the piston body 21 moves to the insertion side Z1 relative to the pressure vessel 10, and friction information when the piston body 21 moves to the withdrawal side Z2 relative to the pressure vessel 10. The drive control unit 65 (see FIG. 2) selects friction information corresponding to the direction of movement of the piston body 21 relative to the pressure vessel 10, and controls the drive device 40 based on the selected friction information.

[0117] The above-mentioned [Configuration 2] provides the following effect. The piston seal friction force may differ depending on the direction of movement of the piston body 21 relative to the pressure vessel 10 (see FIG. 3). In the above-mentioned [Configuration 2], the drive device 40 is controlled based on friction information corresponding to the direction of movement of the piston body 21. Therefore, the pressurizing device 1 can more accurately control the pressure inside the vessel.

[0118] (Effect of the third invention) [Configuration 3] Friction information storage unit 62 (see FIG. 2) stores friction information for each of a plurality of patterns of movement speed of piston body 21 relative to pressure vessel 10. Drive control unit 65 selects friction information corresponding to the movement speed of piston body 21 relative to pressure vessel 10, and controls drive device 40 based on the selected friction information.

[0119] The above [Configuration 3] provides the following effect. The piston seal friction force may differ depending on the moving speed of the piston body 21 relative to the pressure vessel 10. In the above [Configuration 2], the drive device 40 is controlled based on friction information corresponding to the moving speed of the piston body 21. Therefore, the pressurizing device 1 can more accurately control the pressure inside the vessel.

[0120] (Effect of the fourth invention) [Configuration 4] The pressurizing device 1 includes a piston position information detection unit 51. The piston position information detection unit 51 detects position information of the piston main body 21 relative to the pressure vessel 10.

[0121] In the above [Configuration 4], the piston position information detection unit 51 detects position information of the piston body 21 relative to the pressure vessel 10. Therefore, the piston position information detection unit 51 can reliably (directly) detect that the piston body 21 is moving relative to the pressure vessel 10. Therefore, the piston position information detection unit 51 can detect (confirm, guarantee) that a state in which the drive device 40 can be controlled is available based on friction information when the piston body 21 moves relative to the pressure vessel 10. As a result, the pressurizing device 1 can more accurately control the pressure inside the vessel.

[0122] When the pressurizing device 1 is equipped with the above [Configuration 2] and [Configuration 4], the following effects are obtained. In the above [Configuration 2], the drive control unit 65 (see FIG. 2) controls the drive device 40 based on friction information corresponding to the direction of movement of the piston body 21 relative to the pressure vessel 10. In the above [Configuration 4], the piston position information detection unit 51 detects position information of the piston body 21 relative to the pressure vessel 10, thereby being able to reliably (directly) detect the direction of movement of the piston body 21 relative to the pressure vessel 10. As a result, the pressurizing device 1 can more accurately control the pressure inside the vessel.

[0123] When the pressurizing device 1 is equipped with the above [Configuration 3] and [Configuration 4], the following effects are obtained. In the above [Configuration 3], the drive control unit 65 (see FIG. 2) controls the drive device 40 based on friction information corresponding to the moving speed of the piston body 21 relative to the pressure vessel 10. In the above [Configuration 4], the piston position information detection unit 51 detects the position information of the piston body 21 relative to the pressure vessel 10, thereby being able to reliably (directly) detect the moving speed of the piston body 21 relative to the pressure vessel 10. As a result, the pressurizing device 1 can more accurately control the pressure inside the vessel.

[0124] (Effect of the fifth invention) [Configuration 5] The piston axial force information detection unit 53 includes a strain gauge 53a. The strain gauge 53a is attached to the piston body 21 and detects the strain of the piston body 21.

[0125] The strain gauge 53a in the above [Configuration 5] can directly detect piston axial force information. Therefore, the accuracy of the piston axial force information can be improved. Specifically, for example, when the piston axial force information is the pressure of the working fluid of the drive device 40 that drives the piston body 21 (described later), the piston axial force information is affected by the frictional force of the RAM seal 41d. On the other hand, in the above [Configuration 5], the piston axial force information acquired from the strain gauge 53a is not affected by the frictional force of the RAM seal 41d. Because the piston axial force information can be directly detected by the strain gauge 53a, the drive control unit 65 (see FIG. 2) can more accurately control the drive device 40 (the above [Configuration 1-1]) based on the piston axial force information and the frictional information. As a result, the pressurizing device 1 can more accurately control the pressure inside the container.

[0126] (Effect of the seventh invention) [Configuration 7] The drive control unit 65 (see FIG. 2) controls the drive device 40 so that the reciprocating distance of the reciprocating motion of the piston body 21 relative to the pressure vessel 10 gradually decreases during the holding stroke.

[0127] By the above [Configuration 7], the drive control unit 65 (see FIG. 2) can gradually reduce the difference between the target internal pressure of the container (e.g., the above-mentioned "set pressure") and the actual internal pressure of the container. Therefore, the drive control unit 65 (see FIG. 2) can control the internal pressure of the container so that it appropriately approaches the target internal pressure of the container. As a result, the pressurizing device 1 can more accurately control the internal pressure of the container.

[0128] (Effect of the eighth aspect of the invention) [Configuration 8] The pressurizing device 1 includes a pressure sensing member 80. The pressure sensing member 80 is provided so as to be removable from the pressure vessel 10. The pressure sensing member 80 detects the pressure inside the pressure vessel 10 (internal vessel pressure). Friction information is acquired based on piston axial force information detected by the piston axial force information detection unit 53 when the piston body 21 moves relative to the pressure vessel 10, and the pressure inside the pressure vessel 10 detected by the pressure sensing member 80.

[0129] The above [Configuration 8] makes it possible to reliably acquire friction information based on the actual measurement value of the internal pressure of the container (actual internal pressure of the container) detected by the pressure detection member 80. As a result, the pressurizing device 1 can more accurately control the internal pressure of the container.

[0130] In the above [Configuration 8], the pressure sensing member 80 is detachable from the pressure vessel 10. Therefore, even if the pressure sensing member 80 or the pressure derivation member De cannot withstand long-term actual operation, for example, the pressure sensing member 80 or the pressure derivation member De can be detached from the pressure vessel 10 after the friction information has been acquired and before the actual operation begins.

[0131] (Effect of the ninth invention) [Configuration 9] The pressure sensing member 80 is disposed inside the pressure vessel 10 so as to be removable from the inside of the pressure vessel 10. Friction information is acquired with the pressure sensing member 80 disposed inside the pressure vessel 10.

[0132] With the above [Configuration 9], the pressure sensing member 80 can more directly sense the actual pressure inside the pressure vessel 10 while it is disposed inside the pressure vessel 10. As a result, the accuracy of the friction information can be improved. As a result, the pressurizing device 1 can more accurately control the pressure inside the vessel.

[0133] In the above [Configuration 9], the pressure sensing member 80 can be removed from the pressure vessel 10. Therefore, even if the pressure sensing member 80 cannot withstand long-term actual operation, for example, the pressure sensing member 80 can be removed from the pressure vessel 10 after the friction information has been acquired and before the actual operation.

[0134] (Variation) In the above embodiment, the piston axial force information detected by the piston axial force information detection unit 53 includes information obtained by directly detecting the axial force of the piston body 21 or information that can be converted from this information. Specifically, for example, the piston axial force information includes information related to the detection value of the strain gauge 53a. On the other hand, the piston axial force information detected by the piston axial force information detection unit 53 may include information related to the force with which the drive device 40 presses the piston body 21 toward the insertion side Z1. For example, if the drive device 40 is a device that drives the piston body 21 using fluid pressure, the piston axial force information may include information related to the pressure of the working fluid that presses the piston body 21 toward the insertion side Z1.

[0135] In the following, a case will be described in which the piston axial force information detected by the piston axial force information detection unit 53 is information about the pressure of the working fluid for pressing the piston main body 21 toward the insertion side Z1. For example, the piston axial force information may be information about the pressure of the working fluid in the head-side chamber 41a1. The piston axial force information may be information about the fluid pressure detected by the fluid pressure detection unit 45. The piston axial force information detection unit 53 that detects the piston axial force information may also serve as the fluid pressure detection unit 45 for controlling the drive unit 40. Note that the piston axial force information detection unit 53 does not have to also serve as the fluid pressure detection unit 45. More specifically, the piston axial force information detection unit 53 that detects information about the pressure of the working fluid for pressing the piston main body 21 toward the insertion side Z1 as the piston axial force information may be provided separately from the fluid pressure detection unit 45. In the following, a case will mainly be described in which the piston axial force information detection unit 53 also serves as the fluid pressure detection unit 45.

[0136] When the piston axial force information is information related to the fluid pressure for pressing the piston body 21 toward the insertion side Z1, the piston axial force information includes the influence of the frictional force between the ram seal 41d and the cylinder body 41a (ram seal frictional force). More specifically, the piston axial force information includes the influence of the axial force of the piston body 21 due to the pressure inside the container, the axial force of the piston body 21 due to the piston seal frictional force, and the axial force of the piston body 21 due to the ram seal frictional force.

[0137] In this modification, friction information that takes into account the ram seal frictional force is acquired in the preliminary measurement. More specifically, in the preliminary measurement, information related to the fluid pressure detected by the piston axial force information detection unit 53 (e.g., the fluid pressure detection unit 45) is acquired as piston axial force information that includes the influence of the ram seal frictional force. The relationship between this piston axial force information and the actual pressure inside the container (preliminary measurement acquisition relationship R (see FIG. 3)) is acquired. Based on this preliminary measurement acquisition relationship R, friction information is acquired to be stored in the friction information storage unit 62 (see FIG. 2).

[0138] In this modification, in actual operation, as in the preliminary measurement, information related to the fluid pressure detected by the piston axial force information detection unit 53 (e.g., the fluid pressure detection unit 45) is acquired as piston axial force information. Then, the drive control unit 65 (see FIG. 2) controls the drive unit 40 based on the piston axial force information including the influence of the ram seal frictional force and the friction information taking the ram seal frictional force into account. In this way, the drive control unit 65 can control the drive unit 40 in the same way as in the above embodiment. As a result, the pressurizing device 1 can accurately control the pressure inside the container.

[0139] As in the above embodiment, it is preferable to make the conditions that affect the friction information as similar as possible between the preliminary measurement and the actual operation. For example, it is preferable to keep the temperature of the working fluid in the drive unit 40 the same or approximately the same between the preliminary measurement and the actual operation. Also, for example, in the preliminary measurement, friction information may be obtained at various working fluid temperatures. Then, during the actual operation, the drive control unit 65 (see FIG. 2) may select friction information corresponding to the detected working fluid temperature and control the drive unit 40 based on the selected friction information.

[0140] (Effect of the sixth aspect of the invention) The effects of the pressurizing device 1 of this modified example are as follows. The drive device 40 includes a fluid pressure cylinder 41, a fluid pressure detection unit 45, and a fluid pressure control unit 47. The fluid pressure cylinder 41 moves the piston body 21 by fluid pressure. The fluid pressure detection unit 45 detects the fluid pressure supplied to the fluid pressure cylinder 41. The fluid pressure control unit 47 controls the operation of the fluid pressure cylinder 41 based on the fluid pressure detected by the fluid pressure detection unit 45.

[0141] [Configuration 6] The piston axial force information detected by the piston axial force information detection unit 53 includes the fluid pressure detected by the fluid pressure detection unit 45.

[0142] In the above [Configuration 6], the piston axial force information includes the fluid pressure of the hydraulic oil detected by the fluid pressure detection unit 45 for controlling the operation of the fluid pressure cylinder 41. Therefore, the piston axial force information detection unit 53 can serve as both the fluid pressure detection unit 45. Therefore, there is no need to provide a sensor (such as a strain gauge 53a) for acquiring the piston axial force information in addition to the fluid pressure detection unit 45 for controlling the operation of the fluid pressure cylinder 41. Therefore, the pressurizing device 1 can have a simple configuration.

[0143] Furthermore, when a piston axial force information detection unit 53 (for example, a strain gauge 53a) separate from the fluid pressure detection unit 45 is provided, maintenance of both the fluid pressure detection unit 45 and the piston axial force information detection unit 53 is required. Specifically, for example, the strain gauge 53a deteriorates over time, so maintenance of the strain gauge 53a is required. On the other hand, when the piston axial force information detection unit 53 and the fluid pressure detection unit 45 are combined into one unit, the effort and time required for maintenance can be reduced.

[0144] (Other variations) The above-described embodiment and modified examples may be further modified in various ways. For example, the number of components in the above-described embodiment may be changed, or some of the components may not be provided. For example, components may be fixed or connected directly or indirectly. For example, the connections between the components shown in FIG. 2 may be changed. The arrangement of the components shown in FIG. 1 may be changed. For example, the inclusion relationships between the components may be changed in various ways. For example, a component described as a lower-level component included in a higher-level component may not be included in the higher-level component, but may be included in another component. For example, what is described as multiple different members or parts may be combined into a single member or part. For example, what is described as a single member or part may be provided as multiple different members or parts. For example, various parameters (specifically, the amplitude and period of the reciprocating motion of the piston body 21, for example) may be preset in the controller 60 or may be manually set directly by an operator. The various parameters may be calculated by the controller 60 based on information detected by a sensor (for example, the piston axial force information detection unit 53, etc.). For example, the various parameters may not be changed, may be changed by manual operation, or may be changed automatically by the controller 60 in response to certain conditions. For example, each component may have only a part of each characteristic (function, arrangement, shape, operation, etc.).

[0145] (First Measure) A pressure vessel; a piston body fitted inside the pressure vessel so as to be movable toward an insertion side and a withdrawal side with respect to the pressure vessel; a piston seal provided in the piston body and sealing a gap between the piston body and the pressure vessel; a piston axial force information detection unit that detects piston axial force information related to an axial force acting on the piston body in a moving direction of the piston body relative to the pressure vessel; a drive device that moves the piston body relative to the pressure vessel; a friction information storage unit that stores friction information relating to a friction force between the piston seal and the pressure vessel when the piston body moves relative to the pressure vessel; a drive control unit that controls the drive device based on the piston axial force information detected by the piston axial force information detection unit and the friction information stored in the friction information storage unit; Equipped with the drive control unit controls the drive device so that the piston body reciprocates relative to the pressure vessel during a pressure maintaining process in which the pressure inside the pressure vessel is controlled to be constant. Pressure device.

[0146] (Second Measure) The pressure device of the first means, the friction information storage unit stores the friction information when the piston body moves toward an insertion side relative to the pressure vessel, and the friction information when the piston body moves toward a withdrawal side relative to the pressure vessel, the drive control unit selects the friction information corresponding to a direction of movement of the piston body relative to the pressure vessel, and controls the drive device based on the selected friction information. Pressure device.

[0147] (Third Measure) The pressure device of the first or second means, the friction information storage unit stores the friction information for each of a plurality of patterns of movement speed of the piston body relative to the pressure vessel, the drive control unit selects the friction information corresponding to a moving speed of the piston body relative to the pressure vessel, and controls the drive device based on the selected friction information. Pressure device.

[0148] (Fourth Measure) A pressure device of any one of the first to third means, a piston position information detection unit that detects position information of the piston body relative to the pressure vessel, Pressure device.

[0149] (Fifth Measure) A pressure device according to any one of the first to fourth means, the piston axial force information detection unit includes a strain gauge attached to the piston body and detecting a strain of the piston body. Pressure device.

[0150] (Sixth Measure) A pressure device according to any one of the first to fifth means, The drive device is a fluid pressure cylinder that moves the piston body by fluid pressure; a fluid pressure detection unit that detects the fluid pressure supplied to the fluid pressure cylinder; a fluid pressure control unit that controls the operation of the fluid pressure cylinder based on the fluid pressure detected by the fluid pressure detection unit; Equipped with the piston axial force information detected by the piston axial force information detection unit includes a fluid pressure detected by the fluid pressure detection unit; Pressure device.

[0151] (Seventh Measure) A pressure device according to any one of the first to sixth means, the drive control unit controls the drive device so that a reciprocating distance of the reciprocating motion of the piston body relative to the pressure vessel gradually decreases during the holding stroke. Pressure device.

[0152] (Eighth Measure) A pressure device according to any one of the first to seventh means, a pressure sensing member that is detachably provided from the pressure vessel and that senses the pressure inside the pressure vessel; the friction information is acquired based on the piston axial force information detected by the piston axial force information detection unit and the internal pressure of the pressure vessel detected by the pressure detection member when the piston body moves relative to the pressure vessel. Pressure device.

[0153] (9th measure) The pressure device of the eighth means, the pressure sensing member is disposed inside the pressure vessel so as to be removable from the pressure vessel; the friction information is acquired in a state where the pressure sensing member is disposed inside the pressure vessel; Pressure device. [Explanation of symbols]

[0154] 1. Pressure device 10 Pressure vessels 21 Piston body 23 Piston seal 40 Drive unit 41 Fluid pressure cylinder 45 Fluid pressure detection unit 47 Fluid pressure control section 51 Piston position information detection unit 53 Piston axial force information detector 62 Friction information storage unit 65 Drive control unit 80 Pressure sensing member

Claims

1. A pressure vessel; a piston body fitted inside the pressure vessel so as to be movable toward an insertion side and a withdrawal side with respect to the pressure vessel; a piston seal provided in the piston body and sealing a gap between the piston body and the pressure vessel; a piston axial force information detection unit that detects piston axial force information related to an axial force acting on the piston body in a moving direction of the piston body relative to the pressure vessel; a drive device that moves the piston body relative to the pressure vessel; a friction information storage unit that stores friction information related to a friction force between the piston seal and the pressure vessel when the piston body moves relative to the pressure vessel; a drive control unit that controls the drive device based on the piston axial force information detected by the piston axial force information detection unit and the friction information stored in the friction information storage unit; Equipped with the drive control unit controls the drive device so that the piston body continuously reciprocates multiple times relative to the pressure vessel during a maintaining process of controlling the pressure inside the pressure vessel to be constant. Pressure device.

2. The pressure device according to claim 1, the friction information storage unit stores the friction information when the piston body moves toward an insertion side relative to the pressure vessel, and the friction information when the piston body moves toward a withdrawal side relative to the pressure vessel, the drive control unit selects the friction information corresponding to a direction of movement of the piston body relative to the pressure vessel, and controls the drive device based on the selected friction information. Pressure device.

3. The pressure device according to claim 1, a piston position information detection unit that detects position information of the piston body relative to the pressure vessel, Pressure device.

4. The pressure device according to claim 1, the piston axial force information detection unit includes a strain gauge attached to the piston body and detecting a strain of the piston body. Pressure device.

5. A pressure vessel; a piston body fitted inside the pressure vessel so as to be movable toward an insertion side and a withdrawal side with respect to the pressure vessel; a piston seal provided in the piston body and sealing a gap between the piston body and the pressure vessel; a piston axial force information detection unit that detects piston axial force information related to an axial force acting on the piston body in a moving direction of the piston body relative to the pressure vessel; a drive device that moves the piston body relative to the pressure vessel; a friction information storage unit that stores friction information related to a friction force between the piston seal and the pressure vessel when the piston body moves relative to the pressure vessel; a drive control unit that controls the drive device based on the piston axial force information detected by the piston axial force information detection unit and the friction information stored in the friction information storage unit; Equipped with the drive control unit controls the drive device so that the piston body reciprocates relative to the pressure vessel during a pressure maintaining step in which the pressure inside the pressure vessel is controlled to be constant; the friction information storage unit stores the friction information for each of a plurality of patterns of movement speed of the piston body relative to the pressure vessel, the drive control unit selects the friction information corresponding to a moving speed of the piston body relative to the pressure vessel, and controls the drive device based on the selected friction information. Pressure device.

6. A pressure vessel; a piston body fitted inside the pressure vessel so as to be movable toward an insertion side and a withdrawal side with respect to the pressure vessel; a piston seal provided in the piston body and sealing a gap between the piston body and the pressure vessel; a piston axial force information detection unit that detects piston axial force information related to an axial force acting on the piston body in a moving direction of the piston body relative to the pressure vessel; a drive device that moves the piston body relative to the pressure vessel; a friction information storage unit that stores friction information related to a friction force between the piston seal and the pressure vessel when the piston body moves relative to the pressure vessel; a drive control unit that controls the drive device based on the piston axial force information detected by the piston axial force information detection unit and the friction information stored in the friction information storage unit; Equipped with The drive device is a fluid pressure cylinder that moves the piston body by fluid pressure; a fluid pressure detection unit that detects the fluid pressure supplied to the fluid pressure cylinder; a fluid pressure control unit that controls the operation of the fluid pressure cylinder based on the fluid pressure detected by the fluid pressure detection unit; Equipped with the piston axial force information detected by the piston axial force information detection unit includes a fluid pressure detected by the fluid pressure detection unit, the drive control unit controls the drive device so that the piston body reciprocates relative to the pressure vessel during a pressure maintaining step in which the pressure inside the pressure vessel is controlled to be constant. Pressure device.

7. A pressure vessel; a piston body fitted inside the pressure vessel so as to be movable toward an insertion side and a withdrawal side with respect to the pressure vessel; a piston seal provided in the piston body and sealing a gap between the piston body and the pressure vessel; a piston axial force information detection unit that detects piston axial force information related to an axial force acting on the piston body in a moving direction of the piston body relative to the pressure vessel; a drive device that moves the piston body relative to the pressure vessel; a friction information storage unit that stores friction information related to a friction force between the piston seal and the pressure vessel when the piston body moves relative to the pressure vessel; a drive control unit that controls the drive device based on the piston axial force information detected by the piston axial force information detection unit and the friction information stored in the friction information storage unit; Equipped with the drive control unit controls the drive device so that the piston body reciprocates relative to the pressure vessel and so that a reciprocating distance of the reciprocating motion of the piston body relative to the pressure vessel gradually decreases during a maintaining stroke in which control is performed to maintain the pressure inside the pressure vessel constant. Pressure device.

8. A pressure vessel; a piston body fitted inside the pressure vessel so as to be movable toward an insertion side and a withdrawal side with respect to the pressure vessel; a piston seal provided in the piston body and sealing a gap between the piston body and the pressure vessel; a piston axial force information detection unit that detects piston axial force information related to an axial force acting on the piston body in a moving direction of the piston body relative to the pressure vessel; a drive device that moves the piston body relative to the pressure vessel; a friction information storage unit that stores friction information related to a friction force between the piston seal and the pressure vessel when the piston body moves relative to the pressure vessel; a drive control unit that controls the drive device based on the piston axial force information detected by the piston axial force information detection unit and the friction information stored in the friction information storage unit; a pressure sensing member that is detachably provided from the pressure vessel and that senses the pressure inside the pressure vessel; Equipped with the friction information is acquired based on the piston axial force information detected by the piston axial force information detection unit and the pressure inside the pressure vessel detected by the pressure detection member when the piston body moves relative to the pressure vessel, the drive control unit controls the drive device so that the piston body reciprocates relative to the pressure vessel during a pressure maintaining step in which the pressure inside the pressure vessel is controlled to be constant. Pressure device.

9. The pressure device according to claim 8, the pressure sensing member is disposed inside the pressure vessel so as to be removable from the pressure vessel; the friction information is acquired in a state where the pressure sensing member is disposed inside the pressure vessel; Pressure device.

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