Fluid injection or aspiration device

Abstract

The object of the invention is to reduce the cylinder movement speed using a simple configuration while limiting the increase in physical dimensions and the reduction in fluid injection or suction volume. The fluid injection or suction device is provided with a cylinder (11); a piston (12) inserted into the cylinder (11) to separate the interior of the cylinder (11) into a fluid chamber (19) and a fluid chamber (20); guide members (13, 14) supporting the piston (12) and guiding the movement of the cylinder (11), and comprising a first internal flow channel (26) connecting the first fluid chamber (19) to a first external tube (37) and a second internal flow channel (30) connecting the second fluid chamber (20) to a second external tube (38); and nozzles (24, 25) communicating with the fluid chambers (19, 20), respectively, wherein the configuration is such that the tubes in the external tubes (37, 38) communicating with the fluid pressure source (41) are switched in turn; the flow channels from the fluid pressure source (41) to the nozzles (24, 25) comprise a short-circuit flow channel short-circuiting the flow channels communicating with the fluid pressure source (41) and the flow channels not communicating with the fluid pressure source (41), and the short-circuit flow channel is provided with a throttling unit for throttling the flow channels.

Description

Technical Field

[0001] This invention relates to a fluid injection or aspiration device for injecting or aspirating fluid. Background Technology

[0002] As described, for example, in Patent Document 1, a fluid injection or aspiration device is known, in which two nozzles communicate with the outside of a column, each nozzle being supplied to each of two spaces divided by a piston inserted into the column, and fluid is injected or aspirated through the two nozzles between the outside of the column and the two spaces. In this fluid injection or aspiration device, the piston is fixed, and during fluid injection, fluid is supplied from a high-pressure source to one of the spaces, or during fluid aspiration, fluid is aspirated from one of the spaces to a low-pressure source. The fluid injection or aspiration device uses volume changes in the two spaces to move the column.

[0003] Reference List

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-203111 Summary of the Invention

[0006] Technical issues

[0007] In the fluid injection or aspiration device described in Patent Document 1, the column can move at a constant speed when the fluid injection or aspiration volume remains constant. However, for some reason, it is assumed that there are situations where it is necessary to reduce the column's moving speed.

[0008] The column's movement speed can be reduced by adjusting the pressure generated from either a high-pressure or low-pressure source. However, during fluid injection, reducing the column's movement speed by decreasing the pressure generated from the high-pressure source results in a smaller fluid injection volume. Conversely, during fluid aspiration, increasing the column's movement speed by increasing the pressure generated from the low-pressure source results in a smaller fluid aspiration volume.

[0009] The column movement speed can also be reduced by designing the column to increase the maximum volume of the two spaces within the column or by designing the nozzle to have a smaller diameter. However, as the maximum volume of the two spaces within the column increases, the column diameter also increases, which may limit installation space, or as the nozzle diameter decreases, this may lead to a reduction in the fluid injection or aspiration volume.

[0010] In view of the above problems, the object of the present invention is to provide a fluid injection or aspiration device that can reduce the column movement speed with a simple configuration, while preventing an increase in body size and a decrease in fluid injection or aspiration volume.

[0011] Solution to the problem

[0012] The fluid injection or aspiration device according to the present invention injects fluid into or aspirates fluid from a target space via a nozzle. The device comprises: a column formed in the shape of a hollow tube and closed by a sealing member at opposing open ends; a piston inserted into the column in a relatively movable manner between opposing open ends, dividing the interior of the column into a first fluid chamber and a second fluid chamber; a guide extending from the piston inserted into the column, penetrating the sealing member to the outside of the column, and fixed to support the piston and guide movement of the column in a sliding contact with a through-hole in the sealing member, the guide including a first internal flow channel and a second internal flow channel, the first internal flow channel externally connecting the first fluid chamber to a first external tube for communication with each other, and the second internal flow channel externally connecting the second fluid chamber to a second external tube for communication with each other, the guide having a circumferentially external shape area smaller than the circumferentially external shape area of ​​the piston; a first nozzle and a second nozzle. Two nozzles, a first fluid chamber and a target space are interconnected via the first nozzle, and a second fluid chamber and a target space are interconnected via the second nozzle, wherein a pipe connected to a fluid pressure source that generates fluid at a predetermined pressure is configured to switch between a first pipe and a second pipe; and a flow passage from the fluid pressure source to the first nozzle and the second nozzle, comprising a short-circuit flow passage that short-circuits the first fluid chamber and the second fluid chamber, and the short-circuit flow passage enables bidirectional fluid flow, and the short-circuit flow passage has a throttling unit that throttles the flow passage, and the throttling unit is configured to allow fluid to flow from the high-pressure side fluid chamber to the low-pressure side fluid chamber according to an internal pressure difference, the internal pressure difference being generated between one fluid chamber in the first fluid chamber and the second fluid chamber that is connected to the fluid pressure source and another fluid chamber in the first fluid chamber and the second fluid chamber that is not connected to the fluid pressure source, so as to allow relative piston movement while reducing the volume reduction rate of the low-pressure side fluid chamber.

[0013] Advantages of the present invention

[0014] The fluid injection or aspiration device according to the present invention can reduce the column movement speed with a simple configuration, while preventing an increase in the body size and a decrease in the fluid injection or aspiration volume. Attached Figure Description

[0015] [ Figure 1 The illustration shows a schematic configuration of a fluid injection or aspiration device according to the first embodiment.

[0016] [ Figure 2 [Illustration] is an explanatory diagram illustrating the movement of a movable cylinder in direction D1 during injection mode.

[0017] [ Figure 3 [This is an explanatory diagram illustrating the D1 constraint state of a movable cylinder in injection mode.]

[0018] [ Figure 4 [This is an explanatory diagram illustrating the movement of a movable cylinder in direction D2 during injection mode.]

[0019] [ Figure 5 [This is an explanatory diagram illustrating the D2 constraint state of a movable cylinder in injection mode.]

[0020] [ Figure 6 [This is an explanatory diagram illustrating the movement of a movable cylinder in direction D1 during suction mode.]

[0021] [ Figure 7 [This is an explanatory diagram illustrating the D1 constraint state of the movable cylinder in the suction mode.]

[0022] [ Figure 8 [This is an explanatory diagram illustrating the movement of a movable cylinder in direction D2 during suction mode.]

[0023] [ Figure 9 [This is an explanatory diagram illustrating the D2 constraint state of the movable cylinder in the suction mode.]

[0024] [ Figure 10 [Illustrated schematically] is a cross-sectional view of a relevant portion of a fluid injection or aspiration device according to a second embodiment.

[0025] [ Figure 11 [This is a cross-sectional view of the device in the insertion assembly state.]

[0026] [ Figure 12 [Illustrated cross-sectional view of a first variant of the device]

[0027] [ Figure 13 [Illustration 1] is a cross-sectional view illustrating the plug-in assembly state in the first variant.

[0028] [ Figure 14 [Illustrated cross-sectional view] is a schematic representation of a second variant of the device.

[0029] [ Figure 15 [Illustrative image] is a cross-sectional view schematically illustrating a third variation of the device.

[0030] [ Figure 16 [This is a cross-sectional view illustrating the plug-in assembly state in the third variation.]

[0031] [ Figure 17[This is a cross-sectional view illustrating the assembly state of multiple connectors in the third variant.]

[0032] [ Figure 18 [Illustrated diagram] is a schematic configuration diagram of a fluid injection or aspiration device according to a third embodiment.

[0033] [ Figure 19 [This is a schematic diagram illustrating another configuration of the device.]

[0034] [ Figure 20 [Illustrated diagram] is a schematic configuration diagram of a fluid injection or aspiration device according to a fourth embodiment.

[0035] [ Figure 21 [This is a schematic diagram illustrating another configuration of the device.] Detailed Implementation

[0036] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0037] [First Embodiment]

[0038] Reference Figures 1 to 5 The first embodiment describes a fluid injection or aspiration device. Figure 1 This is a cross-sectional view illustrating a schematic configuration of a fluid injection or suction device according to a first embodiment. The fluid injection or suction device (hereinafter simply referred to as the "fluid device") 1 is incorporated into a filter device, for example, as a filter cleaning function. The fluid device 1 is used to remove trapped material deposited on the filter by the filtration function of the filter device by injecting fluid into the filter or by suctioning fluid through the filter. In the schematic configuration, the fluid device 1 includes a piston-cylinder mechanism 2, an external piping system 3 connected to the piston-cylinder mechanism 2, and a control system 4.

[0039] (Piston-cylinder mechanism)

[0040] The piston-cylinder mechanism 2 is a mechanism that injects fluid while moving the fluid injection position or draws fluid while moving the fluid aspiration position. The piston-cylinder mechanism 2 is located in the fluid injection or aspiration target space (hereinafter referred to as the "target space") E. The piston-cylinder mechanism 2 mainly consists of a movable cylinder 11, a piston 12, a first guide member 13, and a second guide member 14.

[0041] Specifically, the movable cylinder 11 is formed in a uniform hollow tube shape in cross-section, and the piston 12 (wherein the circumferential outer shape of the piston 12 is formed along the inner circumferential surface of the movable cylinder 11) is inserted into the movable cylinder 11 in a relatively movable manner between the opposing open ends of the movable cylinder 11. The first guide 13 and the second guide 14 are formed to extend in a uniform solid rod shape in cross-section, and the first guide 13 and the second guide 14 are formed to have an area of ​​the circumferential outer shape smaller than the area of ​​the circumferential outer shape of the piston 12, and the first guide 13 and the second guide 14 are connected to the piston 12 or integrally formed with the piston 12 to enter the state described below. That is, the first guide 13 extends outward from the portion of the inserted piston 12 pointing towards one open end of the movable cylinder 11 through that one open end. The second guide 14 extends outward from the portion of the inserted piston 12 facing the other open end of the movable cylinder 11 through that other open end. At least one of the first guide member 13 and the second guide member 14 (the second guide member 14 in the illustrated example) is fixed to an external structure F outside the piston-column mechanism 2 (or in the target space E. This also applies below). The piston 12 is supported by at least one of the guide members 13 and 14. Thus, the piston-column mechanism 2 is configured such that the movable column 11 is guided by the guide members 13 and 14 to perform reciprocating motion while in sliding contact with the piston 12.

[0042] In the following description, for ease of explanation, it is assumed that the movable column 11 is formed in a straight tube shape, and that the guides 13 and 14 extend straight outward from the piston 12 inserted into the movable column 11, passing through the rear of the opposite open ends of the movable column 11 along the shape of the movable column 11. With this configuration, the movable column 11 can move straight in a direction D1 from the piston 12 toward the first guide 13 or in a direction D2 from the piston 12 toward the second guide 14. The directions D1 and D2 can be selected from various directions, such as vertical and horizontal, depending on the installation orientation of the piston-column mechanism 2.

[0043] One open end of the movable column 11 is closed by a first closing member 15, while the other open end of the movable column 11 is closed by a second closing member 16. A first guide member 13 penetrates the first closing member 15 in a relatively movable manner. A second guide member 14 penetrates the second closing member 16 in a relatively movable manner. The guide members 13 and 14 guide the movement of the movable column 11 by sliding contact on their outer circumferential surfaces with the inner circumferential surfaces of the through holes in the closing members 15 and 16, respectively.

[0044] An annular sealing member 17 (such as an O-ring) is held in a groove formed as a recess that extends across the entire inner circumferential surface of a through-hole in the first sealing member 15, opposite the outer circumferential surface of the first guide member 13. A similar annular sealing member 18 is held in a groove formed as a recess that extends across the entire inner circumferential surface of a through-hole in the second sealing member 16, opposite the outer circumferential surface of the second guide member 14. These sealing members 17 and 18 are configured to contact the outer circumferential surfaces of the guide members 13 and 14, respectively, to maintain a liquid-tight or airtight seal between the interior and exterior of the movable column 11.

[0045] The internal space of the movable cylinder 11, enclosed by the two sealing members 15 and 16, is divided into two spaces by the inserted piston 12: a first fluid chamber 19 and a second fluid chamber 20. Specifically, the first fluid chamber 19 is defined by the piston 12, the first sealing member 15, the movable cylinder 11, and the first guide member 13, while the second fluid chamber 20 is defined by the piston 12, the second sealing member 16, the movable cylinder 11, and the second guide member 14. For example, assuming that the external cross-sectional shapes of the guide members 13 and 14 do not overlap with the external cross-sectional shape of the piston 12 when viewed from direction D1 or direction D2, then the first fluid chamber 19 and the second fluid chamber 20 are cylindrical spaces.

[0046] To precisely divide the internal space of the movable cylinder 11 into two spaces: a first fluid chamber 19 and a second fluid chamber 20, an annular sealing member 21 (such as an O-ring) is held in a recess formed as a concave portion extending over the entire outer circumferential surface of the piston 12 opposite to the inner circumferential surface of the movable cylinder 11. The sealing member 21 is configured to slide in contact with the inner circumferential surface of the movable cylinder 11 as the movable cylinder 11 moves along the guides 13, 14, and to maintain a liquid-tight or airtight seal between the first fluid chamber 19 and the second fluid chamber 20.

[0047] In a movable element (such as a movable column 11 and enclosing members 15, 16) that moves relative to a stationary element (such as piston 12 and guide members 13, 14), a first communication channel 22 is formed, through which a first fluid chamber 19 communicates with a target space E. In the example shown, the first communication channel 22 is drilled in the first enclosing member 15. In the movable element, a second communication channel 23 is also formed, through which a second fluid chamber 20 communicates with the target space E. In the example shown, the second communication channel 23 is drilled in the second enclosing member 16.

[0048] The first connecting channel 22 is provided with a first nozzle 24 protruding toward the target space E and having a hollow tube shape. Similarly, the second connecting channel 23 is provided with a second nozzle 25 protruding toward the target space E and having a hollow tube shape. The first nozzle 24 and the second nozzle 25 inject fluid from the fluid chambers 19 and 20 into the target space E, or draw fluid from the target space E into the fluid chambers 19 and 20, depending on the type of fluid pressure source (described later) of the external piping system 3 connected to the piston-cylinder mechanism 2. The first nozzle 24 has a flow channel cross-sectional area that is significantly smaller than the effective area of ​​the inner surface of the first fluid chamber 19, to which the fluid pressure in the first fluid chamber 19 is applied in direction D1 (hereinafter referred to as the "first effective pressure receiving area"). The second nozzle 25 has a flow channel cross-sectional area that is significantly smaller than the effective area of ​​the inner surface of the second fluid chamber 20, to which the fluid pressure in the second fluid chamber 20 is applied in direction D2 (hereinafter referred to as the "second effective pressure receiving area"). In the following description, for ease of explanation, the first effective pressure receiving area and the second effective pressure receiving area are defined as equal effective column pressure-bearing areas S, and the flow channel cross-sectional area of ​​the first nozzle 24 and the flow channel cross-sectional area of ​​the second nozzle 25 are defined as equal to each other.

[0049] A first internal flow channel 26 is formed within the first guide member 13, connecting the first fluid chamber 19 and the external piping system 3 for communication. Specifically, the first internal flow channel 26 extends from a first internal opening 27 to a first external opening 28. The first internal opening 27 opens towards the first fluid chamber 19 at a portion of the first guide member 13 near the piston 12, and the first external opening 28 opens towards the outside of the piston-column mechanism 2 at the extended end of the first guide member 13. The first external opening 28 is provided with a first connector 29, which connects the first internal flow channel 26 to the external piping system 3 for communication.

[0050] A second internal flow channel 30 is formed within the first guide member 13, the piston 12, and the second guide member 14. This second internal flow channel 30 connects the second fluid chamber 20 and the external piping system 3, enabling communication between them. Specifically, the second internal flow channel 30 extends from a second internal opening 31 to a second external opening 32. The second internal opening 31 opens towards the second fluid chamber 20 at a portion of the second guide member 14 near the piston 12, while the second external opening 32 opens towards the outside of the piston-column mechanism 2 at another extended end of the first guide member 13 spaced apart from the first external opening 28. A second connector 33 is provided at the second external opening 32, connecting the second internal flow channel 30 to the external piping system 3, enabling communication between them.

[0051] The piston-cylinder mechanism 2 configured as described above has a configuration substantially the same as the fluid supply and suction unit disclosed in Japanese Patent Application Publication No. 2016-203111. However, the piston-cylinder mechanism 2 differs from that fluid supply and suction unit in that it includes an orifice flow channel 34 drilled in the piston 12. The orifice flow channel 34 includes a short-circuit flow channel and an orifice (throttling section). The short-circuit flow channel connects (short-circuit) the first fluid chamber 19 and the second fluid chamber 20 for mutual communication, and the orifice (throttling section) serves as a throttling unit for throttling the short-circuit flow channel. The cross-sectional area of ​​the orifice flow channel 34 is set to a value much smaller than the effective cylinder pressure receiving area S described above.

[0052] The piston 12 also functions as a stop, which constrains the movement of the movable cylinder 11 by abutting the second closing member 16 when the movable cylinder 11 moves in direction D1, or by abutting the first closing member 15 when the movable cylinder 11 moves in direction D2. The position of the first closing member 15 when the movement of the movable cylinder 11 in direction D1 is restricted is referred to as the "D1 restricted position". The state of the fluid device 1 when the movement of the movable cylinder 11 is restricted at this position is referred to as the "D1 restricted state". The position of the second closing member 16 when the movement of the movable cylinder 11 in direction D2 is restricted is referred to as the "D2 restricted position". The state of the fluid device 1 when the movement of the movable cylinder 11 is restricted at this position is referred to as the "D2 restricted state".

[0053] Under the D2 constraint state, it is assumed that the first sealing member 15 closes the first internal opening 27, making it difficult for fluid to flow between the target space E and the first internal flow channel 26. Considering this assumption, the first sealing member 15 includes a first protrusion 35 that partially protrudes from the first sealing member 15 toward the first fluid chamber 19. The first protrusion 35 has a protrusion amount set such that when the first protrusion 35 abuts against the piston 12 under the D2 constraint state, the first sealing member 15 is spaced from the piston 12 to a position that prevents the first sealing member 15 from completely closing the first internal opening 27.

[0054] Under the D1 constraint state, it is assumed that the second sealing member 16 closes the second internal opening 31, making it difficult for fluid to flow between the target space E and the second internal flow channel 30. Considering this assumption, the second sealing member 16 includes a second protrusion 36 that partially protrudes from the second sealing member 16 toward the second fluid chamber 20. The second protrusion 36 has a protrusion amount set such that when the second protrusion 36 abuts the piston 12 under the D1 constraint state, the second sealing member 16 is spaced from the piston 12 to a position that prevents the second sealing member 16 from completely closing the second internal opening 31.

[0055] (External piping system)

[0056] The external piping system 3 includes a first external pipe 37, a second external pipe 38, a pressure connection pipe 39, a flow channel switching valve 40, and a fluid pressure source 41. The first external pipe 37 is connected at one end to the first connector 29 and at the other end to the flow channel switching valve 40. The second external pipe 38 is connected at one end to the second connector 33 and at the other end to the flow channel switching valve 40. The pressure connection pipe 39 is connected at one end to the flow channel switching valve 40 and at the other end to the fluid pressure source 41. A three-way solenoid valve is used as the flow channel switching valve 40. The three-way solenoid valve includes a first port connected to the first external pipe 37, a second port connected to the second external pipe 38, and a pressure source port connected to the pressure connection pipe 39. The three-way solenoid valve is configured to close at least one of the first or second ports via external control. Switching between the ports of the three-way solenoid valve allows fluid to flow between the fluid pressure source 41 and the target space E via the piston-pole mechanism 2 through the first or second flow channel system. The first flow channel system includes a first outer pipe 37, a first inner flow channel 26, a first fluid chamber 19, a first connecting channel 22, and a first nozzle 24. The second flow channel system includes a second outer pipe 38, a second inner flow channel 30, a second fluid chamber 20, a second connecting channel 23, and a second nozzle 25.

[0057] As the flow channel switching valve 40, a two-unit bidirectional solenoid valve can be used instead of a three-way solenoid valve. Specifically, the pressure connection pipe 39 connected to the fluid pressure source 41 can be branched into two pipes, so that the branch port of one of the two branch pipes can be connected to the first external pipe 37 through one of the bidirectional solenoid valves, and the branch port of the other branch pipe can be connected to the second external pipe 38 through the other bidirectional solenoid valve. When the bidirectional solenoid valve connected to the first external pipe 37 is open, and the bidirectional solenoid valve connected to the second external pipe 38 is closed, fluid can flow between the fluid pressure source 41 and the target space E via the piston-column mechanism 2 through the first flow channel system. Conversely, when the bidirectional solenoid valve connected to the first external pipe 37 is closed, and the bidirectional solenoid valve connected to the second external pipe 38 is open, fluid can flow between the fluid pressure source 41 and the target space E via the piston-column mechanism 2 through the second flow channel system. In short, the flow channel switching valve 40 can be of any type, as long as it is an externally controllable solenoid valve that allows fluid to flow between the fluid pressure source 41 and the target space E via the piston-column mechanism 2 through the first or second flow channel system.

[0058] As a fluid pressure source 41, a high-pressure source is used when fluid is injected from fluid chambers 19 and 20 into target space E through nozzles 24 and 25, while a low-pressure source is used when fluid is drawn from target space E into fluid chambers 19 and 20 through nozzles 24 and 25.

[0059] The pressure of the high-pressure source in the target space E (hereinafter referred to as "target space pressure") P tgt Fluid is generated under high pressure. Specifically, the generation pressure from the high-pressure source is set to be higher than the target space pressure P. tgt The pressure (P) calculated by taking into account the flow path loss from the high-pressure source to the nozzles 24, 25 (such as the first flow path system or the second flow path system) and other factors Δp. tgt +Δp). For example, a high-pressure source includes a fluid storage tank containing fluid, and a pump that pressurizes the fluid in the storage tank to a given pressure, and may further include a regulator, a buffer tank, and other means of regulating the pressure to a given level. However, relative to the target space pressure P tgt The pressure (P) calculated by taking into account the flow path loss from the high-pressure source to the fluid chamber and other factors Δp. tgt When the pressure (+Δp) is lower than atmospheric pressure, the high-pressure source can be omitted, and the pressure source port can be opened to the atmosphere.

[0060] The low-pressure source is at a pressure P higher than the target space pressure. tgtFluid is generated at a lower pressure. Specifically, the generation pressure from the low-pressure source is set to be lower than the target space pressure P. tgt The pressure (P) calculated by taking into account the flow channel losses from nozzles 24 and 25 to the low-pressure source (such as the first or second flow channel system) and other factors Δp. tgt -Δp). For example, a low-pressure source includes a vacuum pump and may also include a regulator, a buffer tank, and other devices to regulate the pressure to a given level. However, when the target space pressure P tgt When the pressure is higher than that calculated by adding the flow channel loss from nozzles 24 and 25 to the low-pressure source and other factors Δp to atmospheric pressure, the low-pressure source can be omitted and the pressure source port can be opened to the atmosphere.

[0061] (Control system)

[0062] The control system 4 includes a first proximity detector 42, a second proximity detector 43, and a controller 44. The first proximity detector 42 is positioned and configured to output a detection signal when it detects that the movable cylinder 11 has moved to the D1 limit position. The second proximity detector 43 is positioned and configured to output a detection signal when it detects that the movable cylinder 11 has moved to the D2 limit position. Various detection methods can be used for the proximity detectors 42 and 43, including contact methods using limit switches or similar devices, and non-contact methods using proximity sensors that employ optical, magnetic, or electrostatic induction. The controller 44 switches between the ports of the flow channel switching valve 40 by outputting a control signal based on the two output signals from the first proximity detector 42 and the second proximity detector 43.

[0063] The controller 44 includes a microcomputer, which includes a processor such as a CPU (Central Processing Unit). The microcomputer includes ROM (Read-Only Memory), RAM (Random Access Memory), input / output interfaces, and other devices connected to the processor via an internal bus, enabling these devices to communicate with the processor. The controller 44 controls the operation of the fluid device 1 by executing software processing in which the microcomputer's processor reads the operation control program of the fluid device 1 from the ROM to the RAM and executes the operation control program. However, the operation control of the fluid device 1 in the controller 44 can be partially or entirely performed through the hardware configuration of the fluid device 1.

[0064] As described above, various types of fluids can be used as the fluid injected or drawn into the fluid device 1, which includes the piston-cylinder mechanism 2, the external piping system 3, and the control system 4, suitable for the intended use of the fluid device 1. For example, for cleaning purposes, in addition to water, water-soluble detergents, organic solvents, or oils can be used, and further, in gaseous form, air or various other types of gases can be used. For coating purposes, various coatings can be used. For spraying purposes, various types of spray solutions can be used. When the fluid is in liquid form, preferably, the fluid has a viscosity of 0.2 cP to 1000 cP.

[0065] (Fluid injection operation)

[0066] Next, refer to Figures 2 to 5 The injection mode is described. The injection mode is the operating method of the fluid device 1 when fluid is injected from fluid chambers 19 and 20 into the target space E through nozzles 24 and 25. In the injection mode, as described above, a pressure P higher than that of the target space is present. tgt Pressure P H and feed flow Q H The high-pressure source is used as the fluid pressure source 41. In the following description, it is assumed that the first and second flow channel systems are filled with fluid. Unless otherwise specified, the potential energy and pressure loss of the fluid are not considered.

[0067] Figure 2 The diagram illustrates the state in which the movable cylinder 11 moves along direction D1 in injection mode. In this state, the controller 44 outputs a control signal to the three-way solenoid valve to close its second port, thereby moving the movable cylinder 11 along direction D1. With the second port of the three-way solenoid valve closed, the high-pressure source and the first external pipe 37 are interconnected and connected through the first port of the three-way solenoid valve. Therefore, fluid is supplied from the high-pressure source to the first fluid chamber 19. When fluid is supplied from the high-pressure source to the first fluid chamber 19, due to the increase in internal pressure within the first fluid chamber 19, the fluid within the first fluid chamber 19 is injected into the target space E through the first nozzle 24. Simultaneously, the volume of the first fluid chamber 19 increases, causing the movable cylinder 11 to move in direction D1. Then, the volume of the second fluid chamber 20 decreases, and therefore, the fluid in the second fluid chamber 20 is injected into the target space E through the second nozzle 25.

[0068] By using the pressure P generated from a high-pressure source H The internal pressure P in the second fluid chamber 20 B1The balance between the frictional force R (>0) and the effective column pressure receiving area S, applied in injection mode to the movable column 11 moving at a given velocity V1 in direction D1, is expressed by the following equation (1). The left side of the following equation (1) represents the force applied to the movable column 11 in direction D1, while the right side represents the force applied to the movable column 11 in direction D2. In the following equation (1), the pressure P generated from the high-pressure source H The internal pressure P used in the first fluid chamber 19 A1 Without considering the pressure loss as described above, frictional force R1 is generated between the movable column 11 and the piston 12 (or sealing member 21), or between the closing member 15 (or sealing member 17) and the guide member 13, and between the closing member 16 (or sealing member 18) and the guide member 14.

[0069] P H ×S=P B1 ×S+R1…(1)

[0070] By modifying the above equation (1), the internal pressure P in the first fluid chamber 19 is... A1 With the internal pressure P in the second fluid chamber 20 B1 The pressure difference ΔP1 (=P) between them A1 -P B1 The internal pressure P in the first fluid chamber 19 is expressed as the following equation (2), where P is the pressure inside the first fluid chamber 19. A1 The value is equal to the pressure P generated by the high-pressure source. H The value of . According to this equation, it can be understood that the internal pressure P in the first fluid chamber 19 is . A1 The internal pressure P becomes higher than that in the second fluid chamber 20. B1 (P A1 >P B1 ).

[0071] ΔP1=P A1 -P B1 =R1 / S…(2)

[0072] By using the feed flow rate Q of the high-voltage source H The injection flow rate Q of the first nozzle 24 A1 The injection flow rate Q of the second nozzle 25 B1 The balance between the inflow and outflow in the movable column 11 is expressed by the following equation (3). The left side of the following equation (3) represents the inflow to the movable column 11, while the right side represents the outflow from the movable column 11.

[0073] Q H =Q A1 +Q B1 …(3)

[0074] The volume of the second fluid chamber 20 decreases at a rate of [m]. 3 The rate of volume reduction decreases by [ / s], and the rate of volume reduction [m] 3 [ / s] is expressed as a value obtained by multiplying the velocity V1 of the movable column 11 by the effective column pressure receiving area S. However, due to the internal pressure P of the first fluid chamber 19... A1 The internal pressure P of the second fluid chamber 20 is higher than that of the second fluid chamber. B1 Therefore, a small fluid flow rate q1 (>0) flows from the first fluid chamber 19 into the second fluid chamber 20 through the orifice flow channel 34. Based on the cross-sectional area of ​​the orifice flow channel 34 and the pressure difference ΔP1 (=P) between the orifice flow channel 34 and the flow channel 34, the flow rate is determined. A1 -P B1 The minute flow rate q1 is determined by factors including the injection flow rate Q and others. Since the flow rate of the fluid injected by the second nozzle 25 is obtained by adding the rate of volume reduction of the second fluid chamber 20 to the minute flow rate q1, the injection flow rate Q... B1 The following equation (4) holds true.

[0075] Q B1 =S×V1+q1…(4)

[0076] The above equation (4) is modified into the following equation (5) to obtain the velocity V1 of the movable column 11.

[0077] V1=(Q B1 -q1) / S…(5)

[0078] Next, in order to understand the effect of the fluid device 1 in injection mode due to the orifice flow channel 34, the relationship between the velocity of the movable column 11, the injection flow rate of the first nozzle 24, and the injection flow rate of the second nozzle 25 without the orifice flow channel 34 will be described.

[0079] Similar to equation (1) above, by using the pressure P generated from the high-pressure source H The internal pressure P in the second fluid chamber 20 B1 The balance between the frictional force R1' and the effective column pressure receiving area S, applied to the movable column 11 moving in direction D1 at a given velocity V1', is expressed by the following equation (6). The left side of the following equation (6) represents the force applied to the movable column 11 in direction D1, while the right side represents the force applied to the movable column 11 in direction D2.

[0080] P H ×S=P B1 '×S+R1'…(6)

[0081] Similar to equation (3) above, by using the feed flow rate Q of the high-pressure source H The injection flow rate Q of the first nozzle 24 A1 'Injection flow rate Q of the second nozzle 25 B1 The balance between the inflow and outflow in the movable column 11 is expressed by the following equation (7). The left side of the following equation (7) represents the inflow to the movable column 11, while the right side represents the outflow from the movable column 11.

[0082] Q H =Q A1 '+Q B1 '…(7)

[0083] Similarly, the volume of the second fluid chamber 20 decreases at a rate [m] 3 The rate of volume reduction decreases by [ / s], and the rate of volume reduction [m] 3 [ / s] is expressed as a value obtained by multiplying the velocity V1' of the movable cylinder 11 by the effective cylinder pressure receiving area S. However, in the absence of the orifice flow channel 34 in the piston-cylinder mechanism 2, no fluid flow occurs between the first fluid chamber 19 and the second fluid chamber 20. Therefore, since the second nozzle 25 injects fluid at a flow rate equal to the volume reduction rate of the second fluid chamber 20, the injection flow rate Q... B1 The following equation (8) holds true.

[0084] Q B1 '=S×V1'…(8)

[0085] The frictional forces generated between the movable cylinder 11 and the piston 12, or between the sealing member 15 and the guide member 13, and between the sealing member 16 and the guide member 14, vary precisely according to the velocity of the movable cylinder 11. However, the internal pressure P in the second fluid chamber 20 is the force applied to the movable cylinder 11 along direction D2 (see the right side of equations (1) and (6) above). B1 P B1 'The frictional force R1' is more dominant than the frictional force R1'. In view of this, in the above equations (1) and (6), the frictional force R1' applied to the movable column 11 moving at a speed of V1' and the frictional force R1 applied to the movable column 11 moving at a speed of V1 are considered to be equal values ​​(R1' = R1), and then the following equation (9) holds based on the above equations (1) and (6).

[0086] P B1 '=P B1 …(9)

[0087] The injection flow rate of the second nozzle 25 is determined by the internal pressure of the second fluid chamber 20 and the target space pressure P. tgt The pressure difference between them varies, therefore, as shown in equation (9) above, at P B1 '=P B1 In the case of [condition], the following equation (10) holds. From this equation, it can be understood that when the orifice flow channel 34 is absent, the injection flow rate Q of the second nozzle 25 is [value]. B 'Equals the injection flow rate Q of the second nozzle 25 when the orifice flow channel 34 is present.' B .

[0088] Q B1 '=Q B1 …(10)

[0089] Substitute the above equation (10) into the above equation (8), and then modify equation (8) into the following equation (11) to obtain the velocity V' of the movable column 11.

[0090] V1'=Q B1 / S…(11)

[0091] Therefore, based on equations (5) and (11) as described above, the velocity difference ΔV1 (=V1'-V1) between the velocity V1' of the movable column 11 when the orifice flow channel 34 is absent and the velocity V1 of the movable column 11 when the orifice flow channel 34 is present is obtained through the following equation (12). From this equation, it can be understood that the velocity V of the movable column 11 when the orifice flow channel 34 is present is lower than the velocity V' of the movable column 11 when the orifice flow channel 34 is absent.

[0092] ΔV1=V1'-V1=q1 / S…(12)

[0093] Equation (13) below holds based on equations (3), (7), and (10) above. According to this equation, the injection flow rate Q of the first nozzle 24 when the orifice flow channel 34 is absent is... A1 'Injection flow rate Q of the first nozzle 24 when the orifice flow channel 34 is present A1 equal.

[0094] Q A1 '=Q A1 …(13)

[0095] The fluid device 1 includes an orifice flow channel 34 in the manner described above, such that when the movable column 11 moves in the direction D1 in injection mode, the fluid device 1 can reduce the speed of the movable column 11 while preventing a reduction in the injection flow rate of the first nozzle 24 and the injection flow rate of the second nozzle 25.

[0096] Figure 3 The illustration shows the movable cylinder 11 in the D1 restricted state during injection mode. In this state, the movable cylinder 11 stops at the D1 restricted position, maximizing the volume of the first fluid chamber 19 and minimizing the volume of the second fluid chamber 20, and then the volume change stops. When the movable cylinder 11 stops at the D1 restricted position, fluid is initially still supplied to the first fluid chamber 19 from the high-pressure source, and therefore, fluid from the first nozzle 24 continues to be injected. On the other hand, since the volume change of the second fluid chamber 20 stops, the small amount of fluid that enters the second fluid chamber 20 from the first fluid chamber 19 through the orifice flow channel 34 flows out only from the second nozzle 25 to the target space E.

[0097] When the controller 44 detects that the movable column 11 has stopped at the D1 limit position based on the output signal from the first proximity detector 42, the controller 44 outputs a control signal to the three-way solenoid valve to close its first port so as to switch the movement direction of the movable column 11 to direction D2.

[0098] Figure 4 The diagram illustrates the state of the movable cylinder 11 moving in direction D2 during injection mode. In this state, the controller 44 controls and closes the first port of the three-way solenoid switching valve, so the high-pressure source and the second external pipe 38 are interconnected and connected through the second port of the three-way solenoid switching valve. Therefore, fluid is supplied from the high-pressure source to the second fluid chamber 20. When fluid is supplied from the high-pressure source to the second fluid chamber 20, due to the internal pressure P of the second fluid chamber 20... B1 As the volume of the first fluid chamber 19 decreases, the fluid in the second fluid chamber 20 is injected into the target space E through the second nozzle 25. Simultaneously, the volume of the second fluid chamber 20 increases, causing the movable column 11 to move in direction D2. Then, as the volume of the first fluid chamber 19 decreases, the internal pressure P... A1 As the volume increases, the fluid in the first fluid chamber 19 is injected into the target space E through the first nozzle 24.

[0099] When the movable cylinder 11 moves at a given speed V in direction D2, the above equations (1) to (13) are valid by the method described below. That is, in the above equations (1) to (13), the internal pressure P of the first fluid chamber 19 is... A1 P A1 'and the internal pressure P of the second fluid chamber 20 B1 P B1 'Interchange, injection flow rate Q of first nozzle 24' A1 Q A1 'Injection flow rate Q of the second nozzle 25 B1 Q B1'Interchange.' Therefore, the fluid device 1 includes an orifice flow channel 34, and thus the velocity of the movable column 11 in direction D2 can be reduced, while preventing a reduction in the injection flow rate of the first nozzle 24 and the injection flow rate of the second nozzle 25.

[0100] Figure 5 The illustration shows the movable cylinder 11 in the D2 restricted position during injection mode. In this state, the movable cylinder 11 stops at the D2 restricted position, minimizing the volume of the first fluid chamber 19 and maximizing the volume of the second fluid chamber 20, and then the volume change stops. When the movable cylinder 11 stops at the D2 restricted position, fluid is initially supplied from the high-pressure source to the second fluid chamber 20, and thus injection continues from the second nozzle 25. On the other hand, since the volume change of the first fluid chamber 19 stops, the small amount of fluid that enters the first fluid chamber 19 from the second fluid chamber 20 through the orifice flow channel 34 flows out only from the first nozzle 24 to the target space E.

[0101] When the controller 44 detects that the movable cylinder 11 has stopped at the D2 limit position based on the output signal from the second proximity detector 43, the controller 44 outputs a control signal to the three-way solenoid valve to close its second port, thereby switching the movement direction of the movable cylinder 11 to direction D1. Through this operation, as... Figure 2 As shown, the movable cylinder 11 moves again in direction D1.

[0102] (Fluid suction operation)

[0103] Next, refer to Figures 6-9 Describe the suction mode. The suction mode is an operating method for the fluid device 1 when it draws fluid from the target space E into the fluid chambers 19 and 20 via nozzles 24 and 25. In the suction mode, as described above, a pressure P is generated. L Target space pressure P tgt Low and suction flow rate Q L The low-pressure source is used as a fluid pressure source 41.

[0104] Figure 6The diagram illustrates the state in which the movable column 11 moves along direction D1 in suction mode. In this state, the controller 44 outputs a control signal to the three-way solenoid valve to close its first port. With the first port of the three-way solenoid valve closed, the low-pressure source and the second external pipe 38 are interconnected and connected through the second port of the three-way solenoid valve. Therefore, fluid is drawn from the second fluid chamber 20 into the low-pressure source. As fluid is drawn from the second fluid chamber 20 into the low-pressure source, due to the decrease in internal pressure of the second fluid chamber 20, fluid in the target space E is drawn into the second fluid chamber 20 through the second nozzle 25. Simultaneously, the volume of the second fluid chamber 20 decreases, causing the movable column 11 to move in direction D1. Then, the volume of the first fluid chamber 19 increases, so fluid in the target space E is drawn into the first fluid chamber 19 through the first nozzle 24.

[0105] By using the pressure P generated from a low-pressure source L The internal pressure P in the first fluid chamber 19 A2 The balance between the frictional force R2 (>0) and the effective column pressure receiving area S, applied in suction mode to the movable column 11 moving at a given velocity V2 in direction D1, is expressed by the following equation (14). The left side of the following equation (14) represents the force applied to the movable column 11 in direction D1, while the right side represents the force applied to the movable column 11 in direction D2. In the following equation (14), the pressure P generated from the low-pressure source... L The internal pressure P used in the second fluid chamber 20 B2 However, the pressure loss mentioned above is not considered.

[0106] P A2 ×S=P L ×S+R2…(14)

[0107] The internal pressure P in the first fluid chamber 19 A2 With the internal pressure P in the second fluid chamber 20 B2 The pressure difference ΔP2 (=P) between them A2 -P B2 The above equation (14) can be modified to the following equation (15), where the internal pressure P in the second fluid chamber 20 is... B2 The value is equal to the pressure P generated from the low-pressure source. L The value of . From this equation, it can be understood that the internal pressure P in the first fluid chamber 19 is . A2 The internal pressure P becomes higher than that in the second fluid chamber 20. B2 (P A2 >P B2 ).

[0108] ΔP2=P A2-P B2 =R² / S…(15)

[0109] By using a low-pressure source, the suction flow rate Q L The suction flow rate Q of the first nozzle 24 A2 and the suction flow rate Q of the second nozzle 25 B2 The balance between the inflow and outflow in the movable column 11 is expressed by the following equation (16). The left side of the following equation (16) represents the outflow from the movable column 11, while the right side represents the inflow into the movable column 11.

[0110] Q L =Q A2 +Q B2 …(16)

[0111] The volume of the first fluid chamber 19 increases at a rate of [m] 3 As the volume increases by [ / s], the rate of increase in volume [m] 3 [ / s] is expressed as a value obtained by multiplying the velocity V2 of the movable column 11 by the effective column pressure receiving area S. However, due to the internal pressure P of the first fluid chamber 19... A2 The internal pressure P of the second fluid chamber 20 is higher than that of the second fluid chamber. B2 Therefore, a small flow rate q2 (>0) of fluid flows from the first fluid chamber 19 into the second fluid chamber 20 through the orifice flow channel 34. Based on the cross-sectional area of ​​the orifice flow channel 34 and the pressure difference ΔP2 (=P) between the orifice flow channel 34 and the flow channel 34, the flow rate is determined. A2 -P B2 The minute flow rate q2 is determined by adding the rate of increase in volume of the first fluid chamber 19 by the first nozzle 24 to the minute flow rate q2. Therefore, for the suction flow rate Q... A2， The following equation (17) holds true.

[0112] Q A2 =S×V² + q²…(17)

[0113] The above equation (17) is modified to the following equation (18) to obtain the velocity V2 of the movable column 11.

[0114] V2=(Q A2 -q2) / S…(18)

[0115] Next, in order to understand the effect of the fluid device 1 in the suction mode caused by the orifice flow channel 34, the relationship between the velocity of the movable column 11, the suction flow rate of the first nozzle 24, and the suction flow rate of the second nozzle 25 when the orifice flow channel 34 is not provided will be described.

[0116] Similar to equation (14) above, by using the pressure P generated from the low-pressure source L The internal pressure P in the first fluid chamber 19 A2 The balance between the force applied to the movable column 11 moving in the direction D1 at a given velocity V2' in the suction mode, the frictional force R2', and the effective column pressure receiving area S is expressed by the following equation (19).

[0117] P A2 '×S=P L ×S+R2'…(19)

[0118] Similar to equation (16) above, by using the suction flow rate Q of a low-pressure source L The suction flow rate Q of the first nozzle 24 A2 ' and the suction flow rate Q of the second nozzle 25 B2 The balance between the inflow and outflow in the movable column 11 is expressed by the following equation (20).

[0119] Q L =Q A2 '+Q B2 '…(20)

[0120] Similarly, the volume of the first fluid chamber 19 increases at a rate of [m] 3 As the volume increases by [ / s], the rate of increase in volume [m] 3 [ / s] is expressed as a value obtained by multiplying the velocity V2' of the movable cylinder 11 by the effective cylinder pressure receiving area S. Conversely, since the piston-cylinder mechanism 2 does not include the orifice flow channel 34, no fluid flow occurs between the first fluid chamber 19 and the second fluid chamber 20. Therefore, the first nozzle 24 draws fluid at a flow rate equal to the rate of increase in volume of the first fluid chamber 19, thus the drawdown flow rate Q A2 'It satisfies the following equation (21).

[0121] Q A2 '=S×V2'…(21)

[0122] As described above, in the above equations (14) and (19), the frictional force R2' applied to the movable column 11 moving at a speed of V2' and the frictional force R2 applied to the movable column 11 moving at a speed of V2 are considered to be equal values ​​(R2' = R2). Then, based on the above equations (14) and (19), the following equation (22) holds.

[0123] P A2 '=P A2 …(twenty two)

[0124] Because the suction flow rate of the first nozzle 24 is related to the internal pressure of the first fluid chamber 19 and the target space pressure P tgt The corresponding value of the pressure difference between them, therefore, as shown in equation (22) above, at P A2 '=P A2 In the case of [condition], the following equation (23) holds. According to this equation, the suction flow rate Q of the first nozzle 24 when there is no orifice flow channel 34 is [value]. A2 'The suction flow rate Q of the first nozzle 24 when the orifice flow channel 34 is present A2 equal.

[0125] Q A2 '=Q A2 …(twenty three)

[0126] Substitute the above equation (23) into the above equation (20), and then modify equation (20) into the following equation (24) to obtain the velocity V2' of the movable column 11.

[0127] V2'=Q A2 / S…(24)

[0128] Therefore, based on equations (18) and (24) as described above, the velocity difference ΔV2 (=V2'-V2) between the velocity V2' of the movable column 11 when the orifice flow channel 34 is absent and the velocity V2 of the movable column 11 when the orifice flow channel 34 is present is obtained by the following equation (25). From this equation, it can be understood that the velocity V2 of the movable column 11 when the orifice flow channel 34 is present is lower than the velocity V2' of the movable column 11 when the orifice flow channel 34 is absent.

[0129] ΔV2=V2'-V2=q2 / S…(25)

[0130] Equation (26) below holds based on equations (16), (20), and (23) above. According to this equation, the suction flow rate Q of the second nozzle 25 when the orifice flow channel 34 is absent is... B2 'The suction flow rate Q of the second nozzle 25 when the orifice flow channel 34 is present B2 equal.

[0131] Q B2 '=Q B2 …(26)

[0132] The fluid device 1 includes an orifice flow channel 34 in the manner described above, such that when the movable column 11 moves in the direction D1 in the suction mode, the fluid device 1 can reduce the speed of the movable column 11, while preventing a decrease in the suction flow rate of the first nozzle 24 and the second nozzle 25.

[0133] Figure 7 The illustration shows the movable column 11 in the D1 restricted state during suction mode. In this state, the movable column 11 stops at the D1 restricted position, maximizing the volume of the first fluid chamber 19 and minimizing the volume of the second fluid chamber 20, and then the volume change stops. When the movable column 11 stops at the D1 restricted position, fluid is initially still drawn from the second fluid chamber 20 to the low-pressure source, and thus fluid suction continues through the second nozzle 25. On the other hand, since the volume change of the first fluid chamber 19 stops, the minute amount of fluid flowing from the first fluid chamber 19 through the orifice flow channel 34 to the exit of the second fluid chamber 20 enters the first fluid chamber 19 only from the target space E via the first nozzle 24.

[0134] When the controller 44 detects that the movable column 11 has stopped at the D1 limit position based on the output signal from the first proximity detector 42, the controller 44 outputs a control signal to the three-way solenoid valve to close its second port so as to switch the movement direction of the movable column 11 to direction D2.

[0135] Figure 8 The diagram illustrates the state in which the movable column 11 moves along direction D2 in suction mode. In this state, the controller 44 controls and closes the second port of the three-way solenoid switching valve, so the low-pressure source and the first external pipe 37 are interconnected and connected through the first port of the three-way solenoid switching valve. Therefore, fluid is drawn from the first fluid chamber 19 into the low-pressure source. When fluid is drawn from the first fluid chamber 19 into the low-pressure source, due to the internal pressure P of the first fluid chamber 19... A2 As the pressure decreases, the fluid in the target space E is drawn into the first fluid chamber 19 through the first nozzle 24. Simultaneously, the volume of the first fluid chamber 19 decreases, allowing the movable column 11 to move in direction D2. Then, as the volume of the second fluid chamber 20 increases, the internal pressure P... B2 The fluid in the target space E is reduced, so the fluid in the target space E is drawn into the second fluid chamber 20 through the second nozzle 25.

[0136] When the movable cylinder 11 moves in direction D2 at a given speed V2, the above equations (14) to (26) are maintained by the following method. That is, the internal pressure P of the first fluid chamber 19... A2 P A2 'and the internal pressure P of the second fluid chamber 20 B2 P B2 'Interchange, suction flow rate Q of first nozzle 24' A2 Q A2 ' and the suction flow rate Q of the second nozzle 25 B2 Q B2By substitution, equations (14) to (26) above hold. Thus, the fluid device 1 has an orifice flow channel 34, and is therefore able to reduce the velocity of the movable column 11 in the direction D2, while preventing a reduction in the suction flow rate of the first nozzle 24 and the second nozzle 25.

[0137] Figure 9 The illustration shows the movable column 11 in the D2 limiting position during suction mode. In this state, the movable column 11 stops at the D2 limiting position, minimizing the volume of the first fluid chamber 19 and maximizing the volume of the second fluid chamber 20, and then the volume change stops. When the movable column 11 stops at the D2 limiting position, fluid is initially still drawn from the first fluid chamber 19 to the low-pressure source, and therefore, fluid suction continues through the first nozzle 24. On the other hand, since the volume change of the second fluid chamber 20 stops, the small amount of fluid flowing out of the second fluid chamber 20 through the orifice flow channel 34 into the first fluid chamber 19 enters the second fluid chamber 20 only from the target space E through the second nozzle 25.

[0138] When the controller 44 detects that the movable cylinder 11 has stopped at the D2 limit position based on the output signal from the second proximity detector 43, the controller 44 outputs a control signal to the three-way solenoid valve to close its first port, thereby switching the movement direction of the movable cylinder 11 to direction D1. Through this operation, as... Figure 6 As shown, the movable cylinder 11 moves again in direction D1.

[0139] [Second Embodiment]

[0140] refer to Figure 10 and Figure 11 The fluid apparatus according to the second embodiment is described. Furthermore, the fluid apparatus 1a according to this embodiment has the same configuration as the fluid apparatus 1 according to the first embodiment, except for some of its parts, and therefore this identical configuration is labeled with the same reference numerals and the description is omitted or simplified. This also applies to the following embodiments.

[0141] like Figure 10 and Figure 11 As shown, the piston-column mechanism 2a of the fluid device 1a differs from the piston-column mechanism 2 in that a through hole 45 is drilled in the piston 12, which penetrates from the portion of the piston 12 facing the first fluid chamber 19 to the portion of the piston 12 facing the second fluid chamber 20, and a separate connector 46 is removably fitted into the through hole 45, wherein the connector 46 has an orifice flow channel 34 formed therein. Figure 10 The diagram shows the relevant components of the piston-cylinder mechanism 2a before the assembly of the connector. Figure 11The diagram shows the relevant parts of the piston-cylinder mechanism 2a in the plug-in assembly state.

[0142] exist Figure 10 and Figure 11 In a specific example, a generally cylindrical connector 46 is screwed into and fitted into a through-hole 45 having a circular cross-sectional shape. The connector 46 can be removed from the through-hole 45 by screwing in or out an external thread 47 (formed in a helical shape around the threaded axis of rotation of the connector 46 on the outer axial surface of the connector 46) into or out of an internal thread 48 having a generally circular cross-sectional shape formed on the inner circumferential surface of the through-hole 45. An orifice flow channel 34 is formed between the opposing end faces 49 and 50 of the connector 46 in its axial direction. By threading the connector 46 into the through-hole 45, the first fluid chamber 19 and the second fluid chamber 20 communicate with each other through the orifice flow channel 34.

[0143] The mounting groove 51 is formed as a recess on an end face 49 (hereinafter referred to as the "first end face"), which is one of the opposing end faces 49, 50 of the connector 46 in its axial direction and faces the first fluid chamber 19. The mounting groove 51 is an engagement portion for mounting the tip of a shaft tool and transmitting the axial rotational force of the shaft tool to rotate the connector 46 and screw it into or out of the through hole 45. The cross-sectional shape of the mounting groove 51 matches the shape of the tip of the shaft tool used. For example, the mounting groove 51 is a hexagonal hole for mounting the tip of a hex wrench as a shaft tool, or a recess for mounting the tip of a flathead screwdriver as a shaft tool. The orifice flow channel 34 can be configured not to interfere with the mounting groove 51. However, unless there is sufficient area allowance on the first end face 49, the orifice flow channel 34 can be provided in the manner described below. That is, as Figure 10 and Figure 11 As shown, the orifice flow channel 34 can extend from the bottom portion of the mounting groove 51 (e.g., the bottom portion of the hexagonal hole therein where the tip of a hexagonal wrench is fitted) to the end face 50 facing the second fluid chamber 20 (hereinafter referred to as the "second end face").

[0144] A working through-hole 52 is drilled in the first sealing member 15, which is opposite to the first end face 49 of the connector 46, which is threaded into the through-hole 45, and is associated with the first fluid chamber 19. The working through-hole 52 is used when replacing the connector 46. The connector 46 is inserted into the machined through-hole 52 by fitting the tip of a shaft tool into the fitting groove 51 of the connector 46, and thus the connector 46 can be threaded into the through-hole 45. Except during the replacement of the connector 46, the working through-hole 52 is closed by a normally closed cap 53 threaded into its internal threads or by other means.

[0145] Based on the above equations (12) and (25), the speed reduction of the movable column 11 is set according to the values ​​of the minute flow rates q1 and q2 of the orifice flow channel 34, and the values ​​of the minute flow rates q1 and q2 vary according to the cross-sectional area of ​​the flow channel 34. Therefore, if multiple connectors 46 are prepared in advance and the orifice flow channels 34 of the connectors 46 are formed with various flow channel cross-sectional areas, then a connector 46 with an appropriate flow channel cross-sectional area can be selected from these connectors 46 and assembled into the through hole 45, thereby enabling the speed reduction of the movable column 11 to the desired amount.

[0146] Next, refer to Figure 12 and Figure 13 ,describe Figure 10 and Figure 11 The first variation of the piston-column mechanism 2a in the model. Figure 12 The diagram shows the relevant parts of the piston-cylinder mechanism 2a before the assembly of the connector. Figure 13 The illustration shows the relevant parts of the piston-column mechanism 2a in the plug-in assembly state. The plug-in 46a of this variant differs from plug-in 46 in that the second end face 50 of plug-in 46 has a tapered surface 54 protruding coaxially with the axis and in a conical or truncated conical shape. The through hole 45a of this variant differs from through hole 45 in that through hole 45a has opposing conical surfaces 55 as part of its inner circumferential surface. When plug-in 46a is threaded into through hole 45a, the opposing conical surfaces 55 are opposite to the conical surfaces 54 of plug-in 46a. The opposing conical surfaces 55 also have a shape that extends along the shape of the conical surfaces 54 of plug-in 46a.

[0147] The opening 56 of the orifice flow channel 34 in the connector 46a, which opens toward the second fluid chamber 20, is formed such that when the connector 46a is threaded into the through hole 45a, it faces the gap 57 formed between the tapered surface 54 and the opposing tapered surface 55. With this configuration, the gap 57 formed between the tapered surface 54 and the opposing tapered surface 55 forms part of the orifice flow channel 34. Multiple openings 56 opening toward the second fluid chamber 20 can be formed. In this case, as illustrated in the figures, the orifice flow channel 34 can branch into multiple paths within the connector 46a, and the multiple paths can connect to individual openings 56, or each opening 56 can individually have an orifice flow channel 34.

[0148] Minor flow rates q1 and q2 of fluid flow between the first fluid chamber 19 and the second fluid chamber 20 via an orifice flow channel 34 in the connector 46a, which includes a gap 57. The interval of the gap 57 varies depending on the amount of screwing in of the external thread 47 of the connector 46a relative to the internal thread 48 on the through hole 45a. With this configuration, the orifice flow channel 34 has a variable throttling valve that functions as a throttling unit and uses the interval of the gap 57 as a throttling opening for the flow channel. Therefore, by adjusting the aforementioned screwing in amount, the speed of the movable column 11 can be reduced by a desired amount. This eliminates the need to replace the connector. Since the orifice flow channel 34 is provided with a variable throttling valve obtained by using the gap 57, the orifice flow channel 34, which omits the throttling orifice, can be simply used as a short-circuit flow channel that connects (short-circuits) the first fluid chamber 19 and the second fluid chamber 20 so that they communicate with each other.

[0149] Next, refer to Figure 14 ,describe Figure 10 and Figure 11 The second variation of the piston-column mechanism 2a in the model. Figure 14 The illustrations essentially depict the relevant parts of the piston-cylinder mechanism 2a before the assembly of the connector, and also show the connector assembled via dashed lines. The connector 46b in this variant differs from the connector 46 described above in that its second end face 50 has a conical surface 54a recessed into a conical or truncated conical shape coaxial with the axis. A conical structure 58 is supported on the piston 12 in such a way that it prevents the through-hole 45 from being closed on the side of the connector 46b near the second fluid chamber 20. This conical structure 58 is formed such that when the connector 46b is threaded into the through-hole 45, it forms a opposing conical surface 55a opposite to the conical surface 54a. An orifice flow channel 34 is formed on the axis of the connector 46b for uniformly supplying fluid to the gap 57a formed between the conical surface 54a and the opposing conical surface 55a. The gap 57a connected to the orifice flow channel 34 forms part of the orifice flow channel 34.

[0150] Minor flow rates q1 and q2 of fluid flow through an orifice flow channel 34 within a connector 46b, including a gap 57a, between the first fluid chamber 19 and the second fluid chamber 20. The interval of the gap 57a varies depending on the amount of screwing in of the external thread 47 of the connector 46b relative to the internal thread 48 on the through hole 45. With this configuration, the orifice flow channel 34 has a variable throttling valve that functions as a throttling unit and uses the interval of the gap 57a as a throttling opening for the flow channel. Therefore, by adjusting the aforementioned screwing in amount, the connector 46b can reduce the speed of the movable column 11 by a desired amount. This eliminates the need to replace the connector. Since the orifice flow channel 34 is provided with a variable throttling valve obtained by using the gap 57a, the orifice flow channel 34, without the throttling orifice, can be simply used as a short-circuit flow channel that connects (short-circuits) the first fluid chamber 19 and the second fluid chamber 20 so that they communicate with each other.

[0151] Next, refer to Figure 15 and Figure 16 ,describe Figure 10 and Figure 11 The third variation of the piston-column mechanism 2a in the model. Figure 15 The diagram shows the relevant parts of the piston-cylinder mechanism 2a before the assembly of the connector. Figure 16 The illustration shows the relevant parts of the piston-pole mechanism 2a in its inserted assembly state. In this variant, the piston-pole mechanism 2a includes a valve body 59, which is located near the side of the connector 46 facing the second fluid chamber 20 when the connector 46 is fitted into the through hole 45b. The valve body 59 has the function of allowing fluid to flow from the first fluid chamber 19 into the second fluid chamber 20 through the orifice flow channel 34 and preventing fluid from flowing from the second fluid chamber 20 into the first fluid chamber 19 through the orifice flow channel 34.

[0152] In contrast, the difference between through-hole 45b and through-hole 45 is that the connector 46 is configured to be screwed into only half of the through-hole 45b from the first fluid chamber 19 toward the second fluid chamber 20. In the portion of through-hole 45b closer to the second fluid chamber 20 than the second end face 50 of the connector 46 threaded into through-hole 45b, the valve body 59 is held such that it is movable in a penetration direction parallel to through-hole 45b. The valve body 59 includes one or more fluid passage holes 60 through which fluid flowing from the orifice flow passage 34 in the connector 46 threaded into through-hole 45b reaches the second fluid chamber 20. The valve body 59 is formed so that when the valve body 59 moves toward the connector 46 threaded into through-hole 45b (see...), Figure 16The valve body 59 (shown by the dashed line) closes the opening of the orifice flow channel 34 that faces the second end face 50, or closes the intermediate flow channel (not shown) connected to the opening. That is, the fluid channel hole 60 is formed such that the fluid channel hole 60 does not overlap with the opening of the orifice flow channel 34 that faces the second end face 50, or overlaps with the aforementioned intermediate flow channel (not shown) in the penetration direction of the through hole 45b.

[0153] When the internal pressure P in the first fluid chamber 19 A1 P A2 The internal pressure P becomes higher than that in the second fluid chamber 20. B1 P B2 At this time, the valve body 59 moves away from the connector 46. Through this movement, fluid in the first fluid chamber 19 flows through the orifice flow channel 34 and the fluid passage orifice 60, and then flows to the second fluid chamber 20. Conversely, when the internal pressure P in the second fluid chamber 20... B1 P B2 The internal pressure P becomes higher than that in the first fluid chamber 19. A1 P A2 At this time, the valve body 59 moves in the direction toward the connector 46. Since the valve body 59 closes the opening of the orifice flow channel 34 that opens toward the second end face 50, or closes the aforementioned intermediate flow channel (not shown), fluid is prevented from flowing from the second fluid chamber 20 to the first fluid chamber 19. In the manner described above, the valve body 59 allows the movement speed of the movable column 11 in direction D1 to be selectively reduced in both injection and suction modes.

[0154] In both injection and aspiration modes, if the reduction in the moving speed of the movable cylinder 11 is set for directions D1 and D2 respectively, the following can be used: Figure 17 The configuration shown is such that a through hole 45b' is drilled in the piston 12 at a position spaced apart from the through hole 45b. The through hole 45b' is formed such that a connector 46', similar to a plug 46, can be screwed into the first fluid chamber 19 from the second fluid chamber 20, extending only halfway through the through hole 45b'. Then, when the connector 46' is fitted into the through hole 45b', a valve body 59', similar to a valve body 59, can be provided on the side of the connector 46' near the first fluid chamber 19.

[0155] When the internal pressure P in the first fluid chamber 19 A1 P A2 The internal pressure P becomes higher than that in the second fluid chamber 20. B1 P B2 At that time, the valve body 59' moves in the direction toward the connector 46'. For example... Figure 17As shown, because the valve body 59' closes the opening of the orifice flow passage 34' that opens toward the second end face 50', or closes the intermediate flow passage (not shown) connected to the opening, fluid is prevented from flowing from the first fluid chamber 19 to the second fluid chamber 20. Conversely, when the internal pressure P in the second fluid chamber 20... B1 P B2 The internal pressure P becomes higher than that in the first fluid chamber 19. A1 P A2 At this time, the valve body 59' moves away from the connector 46'. Through this movement, the fluid in the second fluid chamber 20 flows through the orifice flow channel 34' and the fluid channel hole 60', and then flows to the first fluid chamber 19. Therefore, as long as the cross-sectional areas of the flow channels in the two holes of the orifice flow channel 34' are different from each other, the reduction in the moving speed of the movable column 11 can be set for directions D1 and D2 respectively.

[0156] The valve bodies 59 and 59' in this variant can also be applied to the first variant in which the connector 46a is assembled into the through hole 45a and the second variant in which the connector 46b is assembled into the through hole 45. That is, the inner circumferential surface of the through hole 45b can be deformed to provide an intermediate flow channel communicating with the gaps 57 and 57a, and the valve bodies 59 and 59' can be provided to close the intermediate flow channel.

[0157] Valve bodies 59, 59' are not limited to having Figures 15 to 17 The configuration is shown. Valve bodies 59, 59' can be made of a flexible material that closes the openings of orifice flow channels 34, 34' that are respectively open toward the second end faces 50, 50'. For example, when the internal pressure P in the first fluid chamber 19... A1 P A2 The internal pressure P becomes higher than that in the second fluid chamber 20. B1 P B2 When the valve body 59 elastically deforms, it releases the opening of the orifice flow channel 34 facing the second end face 50, allowing fluid in the first fluid chamber 19 to flow through the orifice flow channel 34 to the second fluid chamber 20. On the other hand, if the internal pressure P of the second fluid chamber 20... B1 P B2 The internal pressure P becomes higher than that of the first fluid chamber 19. A1 P A2 Then the valve body 59 closes the opening of the orifice flow channel 34 that is open to the second end face 50, thereby preventing fluid from flowing from the second fluid chamber 20 to the first fluid chamber 19 through the orifice flow channel 34.

[0158] [Third Embodiment]

[0159] Reference Figure 18 and Figure 19 The fluid apparatus according to the third embodiment is described. The fluid apparatus 1b according to this embodiment differs from the first embodiment in that, instead of the orifice flow channel 34, a short-circuit flow channel is formed via a short-circuit pipe 61 located outside the movable column 11, short-circuiting the first and second flow channel systems. A flow regulating valve 62 is provided on the short-circuit pipe 61. The flow regulating valve 62 is a throttle valve capable of steplessly regulating the flow rate of the channel by changing its throttle valve opening. Furthermore, the flow regulating valve 62 is an electrically operated valve whose throttle valve opening is controllable by a controller 44. Figure 19 For convenience, the illustrations of protrusions 35 and 36 have been omitted.

[0160] For example, such as Figure 18 As shown, the short-circuit pipe 61 connects the first external pipe 37 and the second external pipe 38 to allow the first external pipe 37 and the second external pipe 38 to communicate with each other, and a flow regulating valve 62 is provided inside the short-circuit pipe 61. As another example, such as... Figure 19 As shown, the short-circuit pipe 61 connects connectors 64 and 66, enabling connectors 64 and 66 to communicate with each other. Connector 64 is connected to the first fluid chamber 19 via a connecting channel 63, and connector 66 is connected to the second fluid chamber 20 via a connecting channel 65. A flow regulating valve 62 is disposed within the short-circuit pipe 61. In short, in the fluid device 1, the short-circuit pipe 61 can short-circuit the first flow channel system and the second flow channel system by connecting movable elements, such as the movable column 11, to each other to enable communication; or by connecting fixed elements that are stationary relative to the movable elements to each other to enable communication.

[0161] A flow regulating valve 62, located in the short-circuit pipe 61, opens with a predetermined throttling valve opening, allowing the aforementioned minute flow rates q1 and q2 to flow between the first and second flow channel systems, similar to the orifice flow channel 34. With this configuration, when the movable column 11 moves in injection mode, its speed can be reduced, while preventing a decrease in the injection flow rate of the first nozzle 24 and the second nozzle 25. Conversely, when the movable column 11 moves in suction mode, its speed can be reduced, while preventing a decrease in the suction flow rate of the first nozzle 24 and the second nozzle 25.

[0162] Based on equations (12) and (25) above, the reduction in velocity of the movable column 11 is set according to the values ​​of the minute flow rates q1 and q2 of the orifice flow channel 34, and the values ​​of the minute flow rates q1 and q2 vary according to the cross-sectional area of ​​the flow channel 34. Therefore, by appropriately adjusting the throttle valve opening of the flow regulating valve 62, the velocity of the movable column 11 can be reduced by the desired amount.

[0163] [Fourth Embodiment]

[0164] Reference Figure 20 and Figure 21 The fluid device according to the fourth embodiment is described. The fluid device 1c according to this embodiment differs from the first embodiment in that: instead of the orifice flow channel 34, a short-circuit flow channel is formed via two short-circuit pipes 61a and 61b located outside the movable column 11, short-circuiting the first and second flow channel systems; a first flow regulating valve 62a is provided in the first short-circuit pipe 61a, and a second flow regulating valve 62b is provided in the second short-circuit pipe 61b. The flow regulating valves 62a and 62b are electrically operated valves similar to the flow regulating valve 62.

[0165] For example, such as Figure 20 As shown, a first flow regulating valve 62a is provided in the first short-circuit pipe 61a connecting the pressure connecting pipe 39 and the first external pipe 37 to allow them to communicate with each other. Additionally, a second flow regulating valve 62b is provided in the second short-circuit pipe 61b connecting the pressure connecting pipe 39 and the second external pipe 38 to allow them to communicate with each other. As another example, if two bidirectional solenoid valves 40a and 40b are used as the aforementioned flow channel switching valve 40, such as... Figure 21 As shown, the first flow regulating valve 62a bypasses the two-way solenoid valve 40a and is installed on the first short-circuit pipe 61a. This first short-circuit pipe connects one of the two branch pipes of the pressure connection pipe 39 to the first external pipe 37 to enable communication between them. Similarly, the second flow regulating valve 62b bypasses the two-way solenoid valve 40b and is installed on the second short-circuit pipe 61b. This second short-circuit pipe connects the other branch pipe of the pressure connection pipe 39 to the second external pipe 38 to enable communication between them.

[0166] When fluid flows between the fluid pressure source 41 and the target space E through the first flow channel system, the second flow regulating valve 62b opens with a predetermined throttle opening, allowing the aforementioned minute flow rates q1 and q2 to flow between the first and second flow channel systems, similar to the orifice flow channel 34. Conversely, when fluid flows between the fluid pressure source 41 and the target space E through the second flow channel system, the first flow regulating valve 62a opens with a predetermined throttle opening, allowing the aforementioned minute flow rates q1 and q2 to flow between the first and second flow channel systems, similar to the orifice flow channel 34. With this configuration, when the movable column 11 moves in injection mode, the speed of the movable column 11 can be reduced, while preventing a decrease in the injection flow rate of the first nozzle 24 and the second nozzle 25. Conversely, when the movable column 11 moves in suction mode, the speed of the movable column 11 can be reduced, while preventing a decrease in the suction flow rate of the first nozzle 24 and the second nozzle 25.

[0167] Based on equations (12) and (25) above, the speed reduction of the movable column 11 is set according to the values ​​of the minute flow rates q1 and q2 of the orifice flow channel 34, which vary according to the cross-sectional area of ​​the flow channel 34. Therefore, by appropriately adjusting the throttle opening of the first flow regulating valve 62a, the speed reduction of the movable column 11 moving in direction D2 in injection mode and in direction D1 moving in suction mode can be set to desired values. Conversely, by appropriately adjusting the throttle opening of the second flow regulating valve 62b, the speed reduction of the movable column 11 moving in direction D1 in injection mode and in direction D2 in suction mode can be set to desired values. Using this configuration, the amount of speed reduction of the movable cylinder 11 can be set to different values ​​between the injection mode and the aspiration mode when the movable cylinder 11 moves along direction D1 and when the movable cylinder 11 moves along direction D2.

[0168] Although the present invention has been specifically described with reference to its preferred embodiments, it is apparent that, based on the basic technical spirit and teachings of the present invention, those skilled in the art can adopt various modifications as described below.

[0169] In the first to fourth embodiments described above, instead of forming the movable cylinder 11 into a straight tube shape and the guides 13 and 14 into straight lines, these elements can be formed as described below. That is, the movable cylinder 11 can be formed into a circular tube shape, and the guides 13 and 14 can extend outward from the piston 12 inserted into the movable cylinder 11 along the shape of the movable cylinder 11 through the opposite open ends of the movable cylinder 11, and then extend in an arcuate curved shape. With this configuration, fluid can still be injected or aspirated into the target even when the injection or aspiration target is curved into an arcuate shape.

[0170] In the movable column 11, a single nozzle is provided for each of the fluid chambers 19 and 20, such that the nozzle communicates with each of the fluid chambers 19 and 20. However, multiple nozzles can be provided for each individual fluid chamber, such that the nozzle communicates with each individual fluid chamber. Furthermore, nozzles 24 and 25 can be directly provided on the movable column 11 without passing through the sealing members 15 and 16 (without passing through the connecting channels 22 and 23), such that nozzles 24 and 25 communicate with the fluid chambers 19 and 20 respectively.

[0171] Instead of determining whether the movable column 11 has reached the D1 limit position or the D2 limit position based on the output signals from the first proximity detector 42 and the second proximity detector 43, the controller 44 can estimate the D1 limit position and the D2 limit position based on the count output of the timer.

[0172] The flow channel switching valve 40 and the flow regulating valves 62, 62a, and 62b can be manually operated valves, rather than externally controllable solenoid or electric valves. In this case, the operator can visually confirm that the movable column 11 has stopped at the D1 or D2 limit position, and then operate the flow channel switching valve 40. This makes the controller 44 unnecessary.

[0173] Instead of the external openings 28 and 32 in the first guide member 13, external openings 28 and 30 can be provided in the second guide member 14, and correspondingly, internal flow channels 26 and 30 can be formed to extend from these openings to the internal openings 27 and 31, respectively. In order to reduce the external cross-sectional shape of the guide members 13 and 14, external opening 28 or external opening 32 can be provided in the second guide member 14, and correspondingly, internal flow channels 26 and 30 can be formed to extend from these openings to the internal openings 27 and 31, respectively.

[0174] When the piston-cylinder mechanism 2 is located in, for example, a cylindrical filter to inject fluid into or draw fluid from the inner circumferential surface of the filter through nozzles 24, 25, the piston-cylinder mechanism 2 is configured as follows: In order for the movable cylinder 11 to perform rotational movement along the outer circumferential surfaces of the piston 12 and guide members 13, 14 in addition to the reciprocating motion described above, the through holes in the sealing members 15, 16, the piston 12, the guide members 13, 14, and the cylinder 11 are formed with respect to each other in a circular cross-sectional shape.

[0175] From the viewpoint of reducing the moving speed of the movable column 11 to the desired value, the technical spirit explained in the first to fourth embodiments described above can be appropriately combined without causing any contradiction. For example, suppose there is a situation where, although an orifice flow channel 34 is drilled in the piston 12, the moving speed of the movable column 11 cannot be reduced to the desired value. For this assumption, the insufficient reduction in moving speed can be compensated by placing the flow regulating valve 62 in the short-circuit pipe 61 that short-circuits the first flow channel system and the second flow channel system, or by placing the flow regulating valves 62a and 62b in the short-circuit pipes 61a and 61b that connect the pressure connecting pipe 39 to the first external pipe 37 and the second external pipe 38 so that they are interconnected.

[0176] List of reference numerals

[0177] 1. 1a, 1b, 1c fluid device; 11 movable column; 12 piston; 13 first guide; 14 second guide; 15 first sealing member; 16 second sealing member; 19 first fluid chamber; 20 second fluid chamber; 24 first nozzle; 25 second nozzle; 26 first internal flow channel; 30 second internal flow channel; 34, 34' orifice flow channel; 37 first external pipe; 38 second external pipe; 39 pressure connection pipe; 40 flow channel switching valve; 41 fluid pressure source; 45, 45a, 45b, 45b' through holes; 46, 46a, 46b, 46' plug-in; 47 external thread; 48 internal thread; 54, 54a conical surface; 55, 55a opposite conical surface; 57, 57a gap; 59, 59' valve body; 61, 61a, 61b short-circuit pipe; 62, 62a, 62b flow regulating valve; E target space.

Claims

1. A fluid injection or aspiration device, said fluid injection or aspiration device injecting fluid into a target space or aspirating fluid from said target space through a nozzle, said device comprising: A column, the column being formed in the shape of a hollow tube and closed at opposite open ends by a closing member; A piston is inserted into a column in a relatively movable manner between the opposing open ends, and divides the interior of the column into a first fluid chamber and a second fluid chamber. A guide member extends from the piston inserted into the cylinder, penetrates the closure member to the outside of the cylinder, and is fixed to support the piston and guide the movement of the cylinder in a sliding contact with a through-hole in the closure member. The guide member includes a first internal flow channel and a second internal flow channel. The first internal flow channel externally connects the first fluid chamber to a first external tube to communicate with it, and the second internal flow channel externally connects the second fluid chamber to a second external tube to communicate with it. The area of ​​the circumferential external shape of the guide member is smaller than the area of ​​the circumferential external shape of the piston. The first nozzle, the first fluid chamber, and the target space are in communication with each other through the first nozzle; and The second nozzle, the second fluid chamber, and the target space are connected to each other through the second nozzle. A pipe, connected to a fluid pressure source that generates fluid at a predetermined pressure, is configured to switch between a first external pipe and a second external pipe. A flow passage from a fluid pressure source to the first nozzle and the second nozzle, the flow passage including a short-circuit flow passage that short-circuits the first fluid chamber and the second fluid chamber, and the short-circuit flow passage enabling bidirectional fluid flow, and the short-circuit flow passage being provided with a throttling unit to restrict the flow passage, and... The throttling unit is configured to cause the fluid to flow from the high-pressure side fluid chamber to the low-pressure side fluid chamber based on an internal pressure difference. The internal pressure difference is generated between one fluid chamber in the first fluid chamber and the second fluid chamber that is connected to the fluid pressure source and another fluid chamber in the first fluid chamber and the second fluid chamber that is not connected to the fluid pressure source, so as to cause relative movement of the piston while reducing the volume reduction rate of the low-pressure side fluid chamber.

2. The fluid injection or aspiration device according to claim 1, wherein, The short-circuit flow channel is formed in the piston.

3. The fluid injection or aspiration device according to claim 2, wherein, The fluid injection or suction device includes an orifice that serves as the throttling unit.

4. The fluid injection or aspiration device according to claim 2 or 3, wherein, A through hole is drilled, extending from the side facing the first fluid chamber through the piston to the side facing the second fluid chamber, and a connector can be removably installed into the through hole. The short-circuit flow channel is formed in the connector, and the first fluid chamber and the second fluid chamber are connected to each other through the short-circuit flow channel.

5. The fluid injection or aspiration device according to claim 4, wherein... The connector is screwed into and assembled into the through hole. The connector includes a tapered surface coaxial with its axis of rotation, and the through hole includes opposing tapered surfaces, wherein when the connector is fitted into the through hole, the opposing tapered surfaces are opposite each other. The short-circuit flow channel is formed to include a gap formed between the conical surface and the opposing conical surface, and The short-circuit flow channel includes a variable throttle valve as the throttling unit, the variable throttle valve having an interval of the gap that varies according to the amount of screwing of the connector relative to the through hole.

6. The fluid injection or aspiration device according to claim 4, wherein, The valve body is located near the side of the connector facing the second fluid chamber to allow fluid to flow from the first fluid chamber into the second fluid chamber through the short-circuit flow channel, and to prevent fluid from flowing from the second fluid chamber into the first fluid chamber through the short-circuit flow channel.

7. The fluid injection or aspiration device according to claim 6, wherein... A separate through-hole is drilled in the piston, through which the first fluid chamber and the second fluid chamber communicate with each other, and the connector can be removably fitted into the separate through-hole as an additional connector. The valve body is positioned near the side of the additional connector facing the first fluid chamber to allow fluid to flow from the second fluid chamber into the first fluid chamber through the short-circuit flow channel, and to prevent fluid from flowing from the first fluid chamber into the second fluid chamber through the short-circuit flow channel.

8. The fluid injection or aspiration device according to claim 1, wherein... The short-circuit flow channel is formed by a short-circuit pipe existing outside the column, and The fluid injection or suction device includes a flow regulating valve disposed in the short-circuit pipe as a throttling unit.

9. The fluid injection or aspiration device according to claim 5, wherein, The valve body is located near the side of the connector facing the second fluid chamber to allow fluid to flow from the first fluid chamber into the second fluid chamber through the short-circuit flow channel, and to prevent fluid from flowing from the second fluid chamber into the first fluid chamber through the short-circuit flow channel.

10. The fluid injection or aspiration device according to claim 9, wherein... A separate through-hole is drilled in the piston, through which the first fluid chamber and the second fluid chamber communicate with each other, and the connector can be removably fitted into the separate through-hole as an additional connector. The valve body is positioned near the side of the additional connector facing the first fluid chamber to allow fluid to flow from the second fluid chamber into the first fluid chamber through the short-circuit flow channel, and to prevent fluid from flowing from the first fluid chamber into the second fluid chamber through the short-circuit flow channel.

11. The fluid injection or aspiration device according to claim 4, wherein, The first sealing member of the sealing member is drilled with a working through hole in which the plug can be inserted and removed. The first sealing member closes one open end of the column, and the working through hole is closed by a normally closed cover in a manner that can be opened and closed.

12. The fluid injection or aspiration device according to claim 11, wherein... The connector is screwed into and assembled into the through hole. The connector includes a tapered surface coaxial with its axis of rotation, and the through hole includes opposing tapered surfaces, wherein when the connector is fitted into the through hole, the opposing tapered surfaces are opposite each other. The short-circuit flow channel is formed to include a gap formed between the conical surface and the opposing conical surface, and The short-circuit flow channel includes a variable throttle valve as the throttling unit, the variable throttle valve having an interval of the gap that varies according to the amount of screwing of the connector relative to the through hole.

13. The fluid injection or aspiration device according to claim 12, wherein, The valve body is located near the side of the connector facing the second fluid chamber to allow fluid to flow from the first fluid chamber into the second fluid chamber through the short-circuit flow channel, and to prevent fluid from flowing from the second fluid chamber into the first fluid chamber through the short-circuit flow channel.

14. The fluid injection or aspiration device according to claim 13, wherein... A separate through-hole is drilled in the piston, through which the first fluid chamber and the second fluid chamber communicate with each other, and the connector can be removably fitted into the separate through-hole as an additional connector. The valve body is positioned near the side of the additional connector facing the first fluid chamber to allow fluid to flow from the second fluid chamber into the first fluid chamber through the short-circuit flow channel, and to prevent fluid from flowing from the first fluid chamber into the second fluid chamber through the short-circuit flow channel.

15. The fluid injection or aspiration device according to claim 11, wherein, The valve body is located near the side of the connector facing the second fluid chamber to allow fluid to flow from the first fluid chamber into the second fluid chamber through the short-circuit flow channel, and to prevent fluid from flowing from the second fluid chamber into the first fluid chamber through the short-circuit flow channel.

16. The fluid injection or aspiration device according to claim 15, wherein... A separate through-hole is drilled in the piston, through which the first fluid chamber and the second fluid chamber communicate with each other, and the connector can be removably fitted into the separate through-hole as an additional connector. The valve body is positioned near the side of the additional connector facing the first fluid chamber to allow fluid to flow from the second fluid chamber into the first fluid chamber through the short-circuit flow channel, and to prevent fluid from flowing from the first fluid chamber into the second fluid chamber through the short-circuit flow channel.

17. A fluid injection or aspiration device, said fluid injection or aspiration device injecting fluid into or aspirating fluid from said target space through a nozzle, said device comprising: A column, the column being formed in the shape of a hollow tube and closed at opposite open ends by a closing member; A piston is inserted into a column in a relatively movable manner between the opposing open ends, and divides the interior of the column into a first fluid chamber and a second fluid chamber. A guide member extends from the piston inserted into the cylinder, penetrates the closure member to the outside of the cylinder, and is fixed to support the piston and guide the movement of the cylinder in a sliding contact with a through-hole in the closure member. The guide member includes a first internal flow channel and a second internal flow channel. The first internal flow channel externally connects the first fluid chamber to a first external tube to communicate with it, and the second internal flow channel externally connects the second fluid chamber to a second external tube to communicate with it. The area of ​​the circumferential external shape of the guide member is smaller than the area of ​​the circumferential external shape of the piston. The first nozzle, the first fluid chamber, and the target space are in communication with each other through the first nozzle; and The second nozzle, the second fluid chamber, and the target space are connected to each other through the second nozzle. A pipe, the pipe being connected to a fluid pressure source that generates fluid at a predetermined pressure, the pipe being configured to switch between a first external pipe and a second external pipe, and The fluid injection or aspiration device includes a short-circuit pipe and a flow regulating valve. The short-circuit pipe connects the first external pipe and the second external pipe to enable communication between them. The flow regulating valve is disposed in the short-circuit pipe as a throttling unit to throttle the flow channel.

18. A fluid injection or aspiration device, said fluid injection or aspiration device injecting fluid into a target space or aspirating fluid from said target space through a nozzle, said device comprising: A column, the column being formed in the shape of a hollow tube and closed at opposite open ends by a closing member; A piston is inserted into a column in a relatively movable manner between the opposing open ends, and divides the interior of the column into a first fluid chamber and a second fluid chamber. A guide member extends from the piston inserted into the cylinder, penetrates the closure member to the outside of the cylinder, and is fixed to support the piston and guide the movement of the cylinder in a sliding contact with a through-hole in the closure member. The guide member includes a first internal flow channel and a second internal flow channel. The first internal flow channel externally connects the first fluid chamber to a first external tube to communicate with it, and the second internal flow channel externally connects the second fluid chamber to a second external tube to communicate with it. The area of ​​the circumferential external shape of the guide member is smaller than the area of ​​the circumferential external shape of the piston. The first nozzle, the first fluid chamber, and the target space are in communication with each other through the first nozzle; and The second nozzle, the second fluid chamber, and the target space are connected to each other through the second nozzle, wherein... A pipe connected to a fluid pressure source, which generates fluid at a predetermined pressure, is configured to switch between a first external pipe and a second external pipe via a flow channel switching valve, the flow channel switching valve being connected to the fluid pressure source via a pressure connection pipe. The flow path from the fluid pressure source to the first nozzle and the second nozzle includes a short-circuit flow path that short-circuits the flow path connected to the fluid pressure source and the flow path not connected to the fluid pressure source. The short-circuit flow channel includes a first short-circuit pipe and a second short-circuit pipe. The first short-circuit pipe bypasses the flow channel switching valve and connects the pressure connection pipe to the first external pipe to enable communication between them. The second short-circuit pipe bypasses the flow channel switching valve and connects the pressure connection pipe to the second external pipe to enable communication between them. The flow regulating valves are respectively installed in the first short-circuit pipe and the second short-circuit pipe as throttling units that throttle each flow channel.

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