Material release system and material release method

Abstract

Efficiently backfill the excavated hole. [Solution] The material discharge system 100 comprises an outer tube 10 extending along a borehole 2, a transport unit 16 movable within the outer tube 10 and whose downward movement is restricted by the outer tube 10 at a predetermined depth, and a working fluid supply device 18 capable of supplying working fluid to the transport unit 16. The transport unit 16 has an inner tube 20, a housing 40 movable downward within the inner tube 20, a pressure chamber 28 partitioned within the inner tube 20 above the housing 40 and into which working fluid is guided, and an opening / closing door 25 provided to open and close the lower opening of the inner tube 20. The material is contained within the housing 40, and the opening / closing door 25 is pushed open by the housing 40 moving downward due to the pressure of the working fluid in the pressure chamber 28.

Description

Technical Field

[0001] The present invention relates to a material discharge system and a material discharge method.

Background Art

[0002] Patent Document 1 discloses a material discharge device that discharges materials into a drilled hole.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, when conducting a boring survey to confirm geological structures or the like, the boring holes drilled are backfilled with materials such as fillers after the survey. The backfilling of the boring holes is performed, for example, as described in Patent Document 1, by transporting a container containing the material to a predetermined depth in the boring hole and then opening the discharge port of the container to discharge the material. To backfill the boring hole, the container has to be lifted and lowered in the boring hole multiple times. However, in a boring hole where the hole wall is likely to collapse, the container may not be able to be lowered to the predetermined depth due to the collapse of earth and sand, or the container may be buried in the collapsed earth and sand and cannot be recovered, which may reduce the working efficiency of the operation of backfilling the boring hole.

[0005] An object of the present invention is to efficiently backfill a drilled hole.

Means for Solving the Problems

[0006] The present invention relates to a material discharge system for discharging material into a borehole, comprising: a cylindrical outer tube extending along the borehole; a transport unit movable within the outer tube and whose downward movement is restricted by the outer tube at a predetermined depth; and a working fluid supply device capable of supplying working fluid to the transport unit. The transport unit comprises: a cylindrical inner tube movable within the outer tube; a housing provided within the inner tube so as to be movable downward; a pressure chamber partitioned within the inner tube above the housing and through which working fluid is introduced; and an opening / closing door provided to open and close the lower opening of the inner tube. The material is contained within the housing, and the opening / closing door is pushed open by the housing, which moves downward due to the pressure of the working fluid in the pressure chamber.

[0007] Furthermore, the present invention relates to a material discharge method for discharging material into a borehole, comprising the steps of: adjusting the lower end position of a cylindrical outer tube extending along the borehole according to the depth to which the material is to be discharged; a cylindrical inner tube movable within the outer tube; a housing provided within the inner tube so as to be movable downward; a pressure chamber partitioned within the inner tube above the housing and through which a working fluid is introduced; and an opening / closing door provided so as to be able to open and close the lower opening of the inner tube, wherein the conveying unit containing material in the housing is inserted into the outer tube and moved downward until its downward movement is restricted by the outer tube; a working fluid is supplied to the conveying unit; the opening / closing door is pushed open by moving the housing downward with the pressure of the working fluid in the pressure chamber; and the material in the housing is discharged into the borehole through the lower opening. [Effects of the Invention]

[0008] According to the present invention, excavated holes can be backfilled efficiently. [Brief explanation of the drawing]

[0009] [Figure 1]This is a schematic diagram showing the overall configuration of a material release system according to an embodiment of the present invention. [Figure 2] This is a cross-sectional view of the outer tube of a material discharge system according to an embodiment of the present invention. [Figure 3] This is a cross-sectional view of a transport unit of a material discharge system according to an embodiment of the present invention. [Figure 4] This figure shows an enlarged view of the cross-section along line AA in Figure 3. [Figure 5] This is an enlarged view of the cross-section along line BB in Figure 3. [Figure 6] This figure shows an enlarged view of the cross-section along the CC line in Figure 3. [Figure 7] This figure shows a material release method according to an embodiment of the present invention, in chronological order. [Figure 8] This diagram illustrates the fracture process of a fragile component, showing the state of the fragile component before it fractures. [Figure 9] This diagram illustrates the fracture process of a fragile component and shows the state of the component after it has fractured. [Figure 10] This figure shows a material release method according to an embodiment of the present invention in chronological order, and represents the state following Figure 7. [Figure 11] This figure shows a material release method according to an embodiment of the present invention in chronological order, and represents the state following Figure 10. [Figure 12] This figure shows a time-series diagram illustrating a material release method according to an embodiment of the present invention, and depicts the state following Figure 11. [Figure 13] This figure shows a modified example of a transport unit for a material discharge system according to an embodiment of the present invention. [Figure 14] This figure shows another modification of the transport unit of the material discharge system according to an embodiment of the present invention. [Figure 15] This is an enlarged view of the cross-section along the DD line in Figure 14. [Figure 16] This diagram shows another variation of the transport unit with the movement restrictions removed. [Figure 17] It is a figure showing a reference example of a material discharging system.

Embodiments for Carrying out the Invention

[0010] Hereinafter, referring to the drawings, a material discharging system and a material discharging method according to an embodiment of the present invention will be described.

[0011] First, referring to FIGS. 1 to 6, the overall configuration of a material discharging system 100 according to an embodiment of the present invention will be described. The material discharging system 100 is a so-called dump beller system that conveys and discharges a filler such as bentonite into a bored hole 2 excavated in the ground 1, for example, to backfill a boring hole excavated for confirming a geological structure or the like. The depth of the bored hole 2 excavated for geological survey reaches several hundred meters, and its inner diameter may be a small diameter of about 20 cm, but the bored hole 2 to which the material discharging system 100 is applied is not limited thereto.

[0012] As shown in FIG. 1, the material discharging system 100 includes a cylindrical outer tube 10 extending along the bored hole 2, a conveying unit 16 that is movable within the outer tube 10 and conveys and discharges a material 5 such as bentonite downward into the bored hole 2, and an operating fluid supply device 18 that supplies an operating fluid such as pressurized water into the outer tube 10 to supply the operating fluid to the conveying unit 16.

[0013] The conveying unit 16 includes a cylindrical inner tube 20 formed to be movable within the outer tube 10, a cylindrical piston 46 provided within the inner tube 20, a storage chamber S partitioned within the inner tube 20 below the piston 46 and storing a material 5 such as bentonite, and a pressure chamber 28 partitioned within the inner tube 20 on the side opposite to the storage chamber S with the piston 46 interposed therebetween and into which a working fluid is introduced. Further, the conveying unit 16 shown in FIG. 1 further includes a housing 40 provided to be movable within the inner tube 20, and the piston 46 is fixed to the housing 40 via a fragile pin 55 described later.

[0014] As shown in FIG. 2, the outer tube 10 is a hollow tubular member and is composed of a plurality of extension tubes 11 connected to each other by screwing or the like, and a restricting tube 12 attached to the lowermost end of the extension tube 11.

[0015] The restricting tube 12 restricts the downward movement of the conveying unit 16 at a predetermined depth. As shown in FIG. 2, a restricting step 13 for restricting the downward movement of the conveying unit 16 by abutting a switching member 30 (described later) provided on the inner tube 20 and a locking groove 14 for locking a latch portion 63 (described later) of the conveying unit 16 are formed on its inner peripheral surface. On the other hand, the inner peripheral surface of the extension tube 11 is a smooth surface without irregularities. The restricting step 13 is a step formed by making the inner diameter of the restricting tube 12 on the lower side smaller than the inner diameter of the restricting tube 12 on the upper side, and functions as a movement restricting portion for restricting the downward movement of the conveying unit 16 and, as will be described later, functions as a position switching portion for switching the position of the switching member 30.

[0016] The lower end position of the restricting tube 12 in the excavation hole 2 is adjusted by changing the number of connected extension tubes 11 and the protruding length of the extension tube 11 from the ground surface. By changing the lower end position of the restricting tube 12 in this way and changing the position of the restricting step 13 that restricts the movement of the conveying unit 16, the depth at which the material 5 is discharged from the conveying unit 16 can be changed.

[0017] Next, with reference to Figures 3-6, the specific configuration of the transport unit 16 will be described. In the following, as shown in Figure 3, the lower part of the transport unit 16 that is on the lower side when inserted into the outer tube 10 will be referred to as "bottom," "downward," or "downward side," and the opposite side will be referred to as "top," "upward," or "upward side."

[0018] The inner tube 20 is a cylindrical member having multiple cylindrical sections. As shown in Figure 3, the inner tube 20 has a first cylindrical section (first inner tube cylindrical section) 21, a second cylindrical section (second inner tube cylindrical section) 22 located above the first cylindrical section 21, and a third cylindrical section (third inner tube cylindrical section) located further above the second cylindrical section.

[0019] The inner diameter of the first cylindrical portion 21 is larger than the inner diameter of the second cylindrical portion 22, the inner diameter of the second cylindrical portion 22 is larger than the inner diameter of the third cylindrical portion 23, and the inner diameter of the first cylindrical portion 21 is larger than the inner diameter of the third cylindrical portion 23. Furthermore, the outer diameter of the first cylindrical portion 21 is larger than the outer diameter of the second cylindrical portion 22, the outer diameter of the second cylindrical portion 22 is larger than the outer diameter of the third cylindrical portion 23, and the outer diameter of the first cylindrical portion 21 is larger than the outer diameter of the third cylindrical portion.

[0020] The first cylindrical portion 21 holds the housing 40 so that it can slide vertically on its inner circumferential surface 21a, and holds the piston 46 so that it can move vertically via the housing 40. The third cylindrical portion 23 is formed in a shape that can hold the fragile member 50, which will be described later.

[0021] Inside the inner tube 20, a pressure chamber 28 is formed in a region surrounded by the second cylindrical portion 22, the third cylindrical portion 23, the housing 40, and the lid portion 61 (described later), through which a working fluid such as pressurized water is introduced. The upper surface 40a of the housing 40 faces the pressure chamber 28. Therefore, when the pressure of the working fluid in the pressure chamber 28 acts on the upper surface 40a of the housing 40, a load is generated that pushes the housing 40 downward. When the fragile member 50 breaks as described later, the housing 40 moves downward along the first cylindrical portion 21 due to this load.

[0022] Below the inner tube 20, an opening / closing door 25 is mounted so as to be rotatable around a support pin 26 for opening and closing the lower opening. The end of the opening / closing door 25 opposite to the end where the support pin 26 is provided is fixed to the first cylindrical portion 21 via a fragile pin 57, which will be described later, thus closing the lower opening of the inner tube 20.

[0023] The inner circumferential surface 21a of the first cylindrical portion 21 is a sliding surface that the outer circumferential surface of the housing 40 slides against. A lower step 21b (restricting portion) is provided at the lower end of the inner circumferential surface 21a to restrict the downward movement of the housing 40, and an upper step 21c is provided at the upper end of the inner circumferential surface 21a to restrict the upward movement of the housing 40.

[0024] The position of the lower step 21b is set so that, as described later, the housing 40, when stopped at the lower step 21b, protrudes a predetermined length from below the inner tube 20 in order to push open the opening / closing door 25 by the housing 40. Note that the position where the upper step 21c is provided is not limited to the position shown in Figure 3, and may be provided, for example, near the middle of the first cylindrical portion 21 in the vertical direction.

[0025] The inner circumferential surface 23a of the third cylindrical portion 23 is an insertion hole into which the fragile member 50 is inserted, and the lid portion 61 of the head portion 60, described later, is attached to the outer circumferential surface of the third cylindrical portion 23. The lid portion 61 functions as a lid member that seals the inner circumferential surface 23a of the third cylindrical portion 23 into which the fragile member 50 is inserted from the outside, preventing the working fluid supplied into the outer tube 10 from flowing into the inner tube 20 through the opening that opens at the upper end surface of the third cylindrical portion 23.

[0026] As shown in Figure 4, the second cylindrical portion 22 has multiple passages 29 that extend radially through it, and a cylindrical switching member 30 capable of closing the passages 29 is provided on the outer circumference of the second cylindrical portion 22. Below the switching member 30, in an axial view (see Figure 4), multiple through holes 31 that extend radially through are formed at positions that are aligned with the passages 29 formed in the second cylindrical portion 22.

[0027] Furthermore, a crescent-shaped or rod-shaped key member 32 is positioned between the second cylindrical portion 22 and the switching member 30 to restrict the rotation of the switching member 30 relative to the second cylindrical portion 22. A accommodating groove for housing the key member 32 is formed on the outer circumferential surface of the second cylindrical portion 22, while a sliding groove for the key member 32 is formed along the axial direction on the inner circumferential surface of the switching member 30.

[0028] Therefore, when the switching member 30 moves upward from the state shown in Figure 3, in other words, when the lower end of the switching member 30 comes into contact with the limiting step 13 of the outer tube 10, the second cylindrical portion 22 moves downward relative to the switching member 30 from the state shown in Figure 3, the passage 29 and the through hole 31 come into communication, and the pressure chamber 28 formed inside the second cylindrical portion 22 comes into communication with the outside through the passage 29 and the through hole 31, that is, it becomes possible to supply a working fluid such as pressurized water into the pressure chamber 28 from the outside. Specifically, as shown in Figure 8 described later, the working fluid supplied into the outer tube 10 is supplied to the pressure chamber 28 through the gap formed between the inner circumferential surface of the outer tube 10 and the outer circumferential surface of the third cylindrical portion 23 and / or the lid portion 61, the gap formed between the inner circumferential surface of the outer tube 10 and the switching member 30, the through hole 31 and the passage 29.

[0029] To summarize the relationship between the passage 29 and the through-hole 31 of the switching member 30, the passage 29 formed in the inner tube 20 of the transport unit 16 is a passage that connects the inside of the inner tube 20 (pressure chamber 28 side) and the outside of the inner tube 20 (inside the outer tube 10 and outside the inner tube 20), and serves as a flow path for the working fluid. The switching member 30 can block the flow of the working fluid flowing through the passage 29 by closing the passage 29, and can also allow the flow of the working fluid flowing through the passage 29 by opening the passage 29 by connecting the passage 29 and the through-hole 31.

[0030] Furthermore, the through-hole 31 of the switching member 30 does not need to be a radially penetrating hole, as long as it functions as a passage connecting the inside and outside of the inner tube 20 by communicating with the passage 29. It may be a notch formed along the radial direction, or a recess or V-shaped groove that opens on the upper end surface and inner circumferential surface of the switching member 30.

[0031] Furthermore, the position of the switching member 30 switches from a closed position, where the lower end of the switching member 30 abuts against the limiting step 13 of the outer tube 10, thereby closing the passage 29, to an open position, where the passage 29 is opened. As a result of this switching of the position of the switching member 30, the passage 29 becomes open and communicates with the through hole 31. Thus, the limiting step 13 functions as a position switching part that switches the position of the switching member 30.

[0032] Furthermore, O-rings 34 and 35 are positioned on the outer circumferential surface of the second cylindrical portion 22, on the upper and lower sides of the passage 29, respectively. As a result, as shown in Figure 3, when the passage 29 is blocked by the switching member 30, the O-rings 34 and 35 prevent working fluids such as pressurized water or liquids such as groundwater from entering the passage 29 through the gap between the outer circumferential surface of the second cylindrical portion 22 and the inner circumferential surface of the switching member 30. In other words, the pressure in the pressure chamber 28 is maintained at a constant, relatively low pressure until working fluid is supplied from the working fluid supply device 18 through the passage 29, as will be described later.

[0033] Furthermore, a lower step 22a is provided at the lower end of the outer circumferential surface of the second cylindrical portion 22 to restrict the downward movement of the switching member 30, and an upper step 22b is provided at the upper end of the outer circumferential surface of the second cylindrical portion 22 to restrict the upward movement of the switching member 30. In the example shown in Figure 3, the lid portion 61 attached to the third cylindrical portion 23 constitutes the upper step 22b, but the upper step 22b may be a plurality of protrusions formed protruding from the outer circumferential surface of the second cylindrical portion 22, or the upper step 22b may be a stepped portion formed by making the outer diameter of the inner tube 20 on its upper side larger than the outer diameter of the inner tube 20 on its lower side.

[0034] The position where the lower step 22a is formed is set such that when the switching member 30 is in contact with the lower step 22a, the passage 29 is sealed by the switching member 30 and the O-rings 34 and 35. The position where the upper step 22b is formed is set such that when the switching member 30 is in contact with the upper step 22b, the passage 29 and the through hole 31 are in communication.

[0035] Furthermore, an O-ring 33 is positioned on the outer circumferential surface of the second cylindrical portion 22 below the lower step 22a, which is compressed by the inner tube 20 and the outer tube 10. By providing the O-ring 33 below the passage 29 in this way, groundwater and the like are prevented from flowing through the gap between the inner circumferential surface of the outer tube 10 and the outer circumferential surface of the first cylindrical portion 21 into the gap between the inner circumferential surface of the outer tube 10 and the outer circumferential surface of the switching member 30, and into the gap between the inner circumferential surface of the outer tube 10 and the outer circumferential surface of the second cylindrical portion 22. At the same time, working fluids such as pressurized water are prevented from flowing out through the gap between the inner circumferential surface of the outer tube 10 and the outer circumferential surface of the switching member 30, and into the gap between the inner circumferential surface of the outer tube 10 and the outer circumferential surface of the second cylindrical portion 22.

[0036] This prevents the working fluid, such as pressurized water supplied from above, from flowing downwards, and as a result, the working fluid can be efficiently introduced into the pressure chamber 28. Furthermore, since the O-ring 33 is positioned below the lower step 22a, and the switching member 30's movement is restricted by contacting the lower step 22a even when it moves downward, the O-ring 33 will not be damaged by the switching member 30. The O-ring 33 may also be positioned on the outer circumferential surface of the first cylindrical portion 21.

[0037] Thus, the inner tube 20 is provided with a passage 29 that allows working fluid such as pressurized water supplied from the working fluid supply device 18 to be guided to the pressure chamber 28, and the transport unit 16 has a switching member 30 that can switch this passage 29 from a closed state to an open state.

[0038] The housing 40 is a cylindrical member having a first cylindrical portion (first cylindrical portion of the housing) 41 that holds the piston 46 so as to be slidable in the vertical direction, and a second cylindrical portion 42 (second cylindrical portion of the housing) that supports a rod 47 extending upward from the piston 46. Inside the housing 40, a storage chamber S is partitioned by the inner circumferential surface 41a of the first cylindrical portion 41 and the lower end surface 46a of the piston 46, in which a material 5 such as pelletized bentonite is contained. Thus, the storage chamber S and the pressure chamber 28 are partitioned inside the inner tube 20 with the piston 46 in between.

[0039] The inner circumferential surface 41a of the first cylindrical portion 41 is a sliding surface against which the outer circumferential surface of the piston 46 slides, and a lower step 41b is provided at the lower end of the inner circumferential surface 41a that abuts against the lower end surface 46a of the piston 46, thereby restricting the downward movement of the piston 46. On the other hand, the upward movement of the piston 46 is restricted by the upper end surface 46b of the piston 46 abutting against a step 43 formed between the inner circumferential surface 41a of the first cylindrical portion 41 and the inner circumferential surface 42a of the second cylindrical portion 42. In other words, the piston 46 is housed in the housing 40 with its annular upper end surface 46b, formed on its upper surface, in contact with the step 43 of the housing 40.

[0040] Furthermore, the lower step 41b is not annular, but rather has a discontinuous shape in the circumferential direction, as shown in Figure 5. Specifically, the lower step 41b is formed, for example, by cutting out multiple notches along the inner circumferential surface 41a in the axial direction from a step that was initially formed in an annular shape. In this way, by not making the lower step 41b that protrudes radially inward annular, it is possible to prevent the lower step 41b from hindering the movement of the material 5 when the material 5 contained in the storage chamber S is pushed out by the piston 46, as will be described later.

[0041] Furthermore, a stepped portion 41c is formed on the outer circumferential surface of the first cylindrical portion 41, which can abut against the lower step 21b formed on the inner tube 20 to restrict the downward movement of the housing 40. In other words, the downward movement of the housing 40 relative to the inner tube 20 is restricted by the step 41c abutting against the lower step 21b. It is preferable that the outer circumferential surface of the portion of the first cylindrical portion 41 above the stepped portion 41c is formed to have the same diameter as the outer circumferential surface of the second cylindrical portion 42.

[0042] Furthermore, a pressing portion 44 is provided at the lower end of the first cylindrical portion 41 to press against the opening / closing door 25. The pressing portion 44 is the part that first comes into contact with the opening / closing door 25 when the housing 40 moves downward inside the inner tube 20.

[0043] Here, as shown in Figure 6, the opening / closing door 25 is fixed to the first cylindrical portion 21 of the inner tube 20 via a fragile pin 57 that penetrates both the opening / closing door 25 and the first cylindrical portion 21 of the inner tube 20. In other words, if the fragile pin 57 breaks, the opening / closing door 25 rotates around the support pin 26, opening the lower opening of the inner tube 20, that is, making it possible to release the material 5 contained in the containment chamber S.

[0044] In other words, the pressing portion 44 is provided to generate a load between the first cylindrical portion 21 and the opening / closing door 25 that will break the fragile pin 57. For this reason, the pressing portion 44 is shaped to contact the portion of the opening / closing door 25 closer to the fragile pin 57, and to concentrate the load on this portion. Specifically, as shown in Figure 3, the lower edge of the first cylindrical portion 41 is formed to be inclined so as to protrude downward toward the fragile pin 57, and the portion that protrudes the most downward is the pressing portion 44.

[0045] The piston assembly 45 is a stepped rod-shaped member in which the piston 46 and a rod 47 extending upward from the piston 46 are integrated. The rod 47 is fixed to the second cylindrical portion 42 via a fragile pin 55, thereby fixing it to the housing 40. In other words, if the fragile pin 55 breaks, the piston 46 can move vertically within the housing 40.

[0046] Furthermore, a fragile member 50 is attached to the upper end of the rod 47.

[0047] The fragile member 50 is a member made of a relatively low-strength material such as an aluminum alloy, and has a flange portion 51 with a diameter larger than the inner circumferential surface 23a of the third cylindrical portion 23, an insertion portion 52 that is inserted into the rod 47, and a constricted portion 53 provided between the flange portion 51 and the insertion portion 52. As shown in Figure 3, the fragile member 50 is installed so that the constricted portion 53 is housed inside the third cylindrical portion 23, and the amount of insertion of the insertion portion 52 into the rod 47 is set so that the housing 40 contacts the upper step 21c of the inner tube 20.

[0048] The fragile member 50 is provided to fix the housing 40, which is integrated with the piston assembly 45 via a fragile pin 55, to the inner tube 20. In other words, if the fragile member 50 breaks at the constricted portion 53, the housing 40 and piston assembly 45 become movable within the inner tube 20.

[0049] The head portion 60, which is attached to the upper part of the inner tube 20 via the lid portion 61, constitutes part of the transport unit 16 and has a pair of latch portions 63 and a spearhead 65 used when lifting the transport unit 16.

[0050] The pair of latch portions 63 are a pair of plate-shaped members attached via support pins 63a to extension portions 62 that extend upward from the lid portion 61, and each is rotatable around the support pins 63a. The upper ends of the pair of latch portions 63 are biased radially outward by springs (not shown).

[0051] The spearhead 65 is fixed via a fixing pin 66 to the upper part of a cylindrical member 64 that surrounds the extension portion 62, and its upper end is shaped to allow connection of the lifting dock of the overshot assembly used when retrieving the transport unit 16.

[0052] The cylindrical member 64 is connected to the extension portion 62 so as to be movable in the vertical direction via a connecting pin 67 that passes through an elongated hole 62a formed in the extension portion 62 along the vertical direction. The cylindrical member 64 also has a pair of slits 64a formed therein so that a pair of latch portions 63 can protrude radially outward.

[0053] Therefore, when a load that pulls up the spearhead 65 acts on the cylindrical member 64 via the spearhead 65, as shown in Figure 12 described later, the cylindrical member 64 is pulled upward together with the spearhead 65, and the lower ends of the pair of slits 64a come into contact with the pair of latch portions 63, causing the upper ends of the pair of latch portions 63 to move radially inward against the biasing force of the spring.

[0054] Thus, the pair of latches 63 provided on the head portion 60 are configured to be able to engage with and release the locking grooves 14 provided on the inner circumferential surface of the regulating pipe 12. In other words, the latches 63 are components that can be moved in and out radially from the conveying unit 16.

[0055] When the pair of latches 63 are locked in the locking groove 14, the upward movement of the transport unit 16 is restricted. Therefore, even if, for example, groundwater pressure acts on the underside of the transport unit 16, creating an upward force, the transport unit 16 is prevented from moving upward. In this way, the locking groove 14 functions as a movement restrictor that limits the upward movement of the transport unit 16.

[0056] Furthermore, the downward movement of the transport unit 16 is restricted when the switching member 30 comes into contact with the limiting step 13 of the regulating pipe 12, and the upward movement of the switching member 30 is restricted by the upper step 22b. In other words, the upper step 22b provided on the transport unit 16 engages with the limiting step 13 provided on the regulating pipe 12 of the outer tube 10 via the switching member 30, thereby restricting the downward movement of the transport unit 16 to a predetermined depth. In this way, the limiting step 13 functions as a movement limiting unit that restricts the downward movement of the transport unit 16.

[0057] In this embodiment, the restricting step 13 functions as a position switching unit for switching the position of the switching member 30, and also as a movement restricting unit that restricts the downward movement of the transport unit 16. Alternatively, two different stepped sections may be provided in the restricting pipe 12 of the outer tube 10, with one stepped section functioning as a position switching unit for switching the position of the switching member 30, and the other stepped section functioning as a movement restricting unit that restricts the downward movement of the transport unit 16.

[0058] Furthermore, the position switching section and the movement limiting section are not limited to parts formed in a stepped shape, such as the limiting step 13, but may also be formed in a groove shape in the regulating pipe 12 of the outer tube 10, as shown in the modified examples in Figures 14 to 16 described later.

[0059] On the other hand, when the pair of latches 63 are released from their engagement with the locking groove 14, the transport unit 16 becomes capable of moving upward.

[0060] The working fluid supply device 18, which supplies working fluid to the transport unit 16 configured as described above, is a pressurized pump that pressurizes water and supplies pressurized water as working fluid to the transport unit 16 through the outer tube 10. Note that the working fluid is not limited to pressurized water and may be other pressurized fluids.

[0061] Next, with reference to Figures 7 to 12, a material release method using the material release system 100 with the above configuration will be described.

[0062] First, as shown in Figure 7(a), the outer tube 10 is inserted into the borehole 2 to a predetermined depth. Specifically, the lower end position of the outer tube 10, i.e., the position of the regulating pipe 12, is adjusted by pushing the outer tube 10 down or up depending on the depth to which the material 5 is to be discharged (adjustment step). In addition, extension pipes 11 may be added or removed as needed.

[0063] If a collapse occurs within the borehole 2 and the outer tube 10 cannot be inserted to a predetermined depth, the collapsed soil may be removed beforehand, for example, by a known wireline method. In this case, the outer tube 10 may also be used as a drilling rod.

[0064] Once the outer tube 10 is installed, the next step is to proceed as shown in Figure 7(b), The transport unit 16, containing the material 5 in the containment chamber S, is inserted into the outer tube 10 and moved downward (movement process). The transport unit 16 descends inside the outer tube 10 due to its own weight, but if downward movement is hindered by the water pressure of groundwater, pressurized water may be supplied from the working fluid supply device 18, and the transport unit 16 may be moved downward by the pressure of the pressurized water.

[0065] Furthermore, while the transport unit 16 is moving downward, the passage 29 is closed by the switching member 30, and the gap between the outer surface of the second cylindrical portion 22 and the inner surface of the switching member 30 is sealed by the O-rings 34 and 35. Therefore, even if groundwater or the like enters the outer tube 10, it is prevented from entering the pressure chamber 28 through the passage 29. In addition, because the switching member 30 is biased radially outward by the repulsive force (restoring force) of the O-rings 34 and 35, the position of the switching member 30 is prevented from switching from a position that closes the passage 29 to a position that opens it while the transport unit 16 is moving downward.

[0066] When the transport unit 16 reaches a predetermined depth, its downward movement is restricted by a restricting pipe 12 located at the lowest end of the outer tube 10, as shown in Figure 7(c).

[0067] Specifically, the switching member 30 comes into contact with the limiting step 13 of the regulating pipe 12, and after the switching member 30 moves upward relative to the transport unit 16 and the inner tube 20, further upward movement of the switching member 30 is restricted by the upper step 22b, thereby restricting the downward movement of the transport unit 16.

[0068] At the same time, the pair of latches 63 engage with the locking grooves 14 provided on the inner circumferential surface of the regulating pipe 12, thereby restricting the upward movement of the transport unit 16.

[0069] By restricting downward and upward movement in this way, the transport unit 16 remains stationary at a predetermined position.

[0070] When it is confirmed that the transport unit 16 has reached a predetermined depth and stopped, pressurized water is supplied from the working fluid supply device 18 (supply process). Whether or not the transport unit 16 has reached a predetermined depth and stopped is determined by detecting, for example, the impact sound generated when the switching member 30 comes into contact with the limiting step 13, the impact sound generated when the switching member 30 comes into contact with the upper step 22b, and the impact sound generated when the pair of latch parts 63 engage with the locking groove 14. Alternatively, a beacon transmitter may be provided on the transport unit 16, and it may be determined whether or not the transport unit 16 has reached a predetermined depth by detecting its position.

[0071] When the switching member 30 comes into contact with the limiting step 13 of the outer tube 10 and moves relatively upward relative to the inner tube 20, and then comes into contact with the upper step 22b, the transport unit 16 stops inside the outer tube 10, as shown in Figure 8, the passage 29 and the through hole 31 are in communication, that is, pressurized water (working fluid) can be supplied into the pressure chamber 28 through the passage 29 and the through hole 31.

[0072] In this state, the pressurized water supplied from the working fluid supply device 18 passes through the gap between the inner surface of the regulating pipe 12 and the outer surface of the switching member 30, as shown by the arrows in Figure 8, through the through hole 31 and the passage 29, and into the pressure chamber 28.

[0073] In this embodiment, the downward movement of the transport unit 16 is restricted by the limiting step 13 provided in the outer tube 10, and at almost the same time, the through hole 31 of the switching member 30 and the passage 29 become connected, and the passage 29 that guides the working fluid to the pressure chamber 28 becomes open. In other words, the passage 29 becomes open when the downward movement of the transport unit 16 is restricted by the limiting step 13 which functions as a movement limiting part, and when the position of the switching member 30 is switched from a closed position to an open position by the limiting step 13 which functions as a position switching part, and as a result the working fluid is guided to the pressure chamber 28 through the passage 29.

[0074] However, by providing a plug made of an elastic material such as rubber inside the through-hole 31 or the passage 29, which is removed with a slight time delay after the pressure of the working fluid acts on the through-hole 31, it is possible to create a slight time difference between restricting the downward movement of the transport unit 16 and opening the passage 29. In this way, it is possible to make the passage 29 open almost simultaneously with, or with a slight time delay, the downward movement of the transport unit 16 being restricted by the outer tube 10.

[0075] The pressurized water supplied into the pressure chamber 28 acts on the upper surface 40a (pressure-receiving surface) of the housing 40 facing the pressure chamber 28, generating a load that pushes the housing 40 downward. This downward load on the housing 40 acts on the piston assembly 45 via the upper end surface 46b of the piston 46 that abuts against the stepped portion 43 of the housing 40. As a result, the downward load caused by the pressure of the pressurized water in the pressure chamber 28 acts on the fragile member 50 via the rod 47 of the piston assembly 45.

[0076] When the load acting on the fragile member 50 via the rod 47, that is, the load pulling the insertion portion 52 of the fragile member 50 downwards, exceeds the breaking load of the constricted portion 53, the constricted portion 53 breaks, as shown in Figure 9. When the constricted portion 53 breaks, in addition to the upper surface 40a of the housing 40, the upper end surface of the rod 47 facing the pressure chamber 28 and the upper surface of the broken fragile member 50 become pressure-receiving surfaces that receive the pressure of the pressurized water in the pressure chamber 28. The pressure acting on these pressure-receiving surfaces generates a load that moves the housing 40 and the piston assembly 45 downwards, and the housing 40, together with the piston assembly 45, moves downwards inside the inner tube 20.

[0077] The breaking load of the constricted portion 53 is predetermined based on the pressure of the pressurized water supplied from the working fluid supply device 18, the size of the pressure-receiving surface of the housing 40 facing the pressure chamber 28, the cross-sectional area of ​​the constricted portion 53, etc., so that the constricted portion 53 breaks when pressurized water of a predetermined pressure is supplied from the working fluid supply device 18.

[0078] The downward movement of the housing 40 is restricted by the contact between the stepped portion 41c of the housing 40 and the lower step 21b of the inner tube 20, as shown in Figure 10. In other words, at the contact point between the stepped portion 41c of the housing 40 and the lower step 21b of the inner tube 20, a reaction force is generated that resists the load corresponding to the pressure in the pressure chamber 28 acting on the upper surface 40a of the housing 40. As a result, the housing 40 is stopped relative to the inner tube 20.

[0079] Furthermore, before the stepped portion 41c contacts the lower step 21b, the pressing portion 44 of the housing 40 contacts the portion of the opening / closing door 25 near the fragile pin 57, causing the fragile pin 57 to break. As a result, the opening / closing door 25 is pushed open by the housing 40 protruding from the lower end of the inner tube 20, as shown in Figure 10.

[0080] The breaking load of the fragile pin 57 is predetermined based on the pressure of the pressurized water supplied from the working fluid supply device 18, the size of the pressure-receiving surfaces of the housing 40 and piston assembly 45 on which the pressurized water acts, the contact area between the opening / closing door 25 and the pressing part 44, the distance between the position where the pressing part 44 contacts the opening / closing door 25 and the installation position of the fragile pin 57, the cross-sectional area of ​​the fragile pin 57, etc., so that the fragile pin 57 breaks when a predetermined load is applied to the opening / closing door 25.

[0081] With the movement of the housing 40 relative to the inner tube 20 restricted, the upper end surface of the rod 47 facing the pressure chamber 28 and the upper surface of the fractured weak member 50 become pressure-receiving surfaces that receive the pressure of the pressurized water in the pressure chamber 28, i.e., the pressure-receiving surfaces of the piston assembly 45. The pressurized water supplied to the pressure chamber 28 acts on these pressure-receiving surfaces, as indicated by the arrows in Figure 10, generating a load that pushes the piston assembly 45 further downward relative to the housing 40.

[0082] When this load exceeds the breaking load of the fragile pin 55, which is provided through the rod 47 of the piston assembly 45 and the second cylindrical portion 42 of the housing 40, and the fragile pin 55 breaks, as shown in Figure 11, the upper end surface 46b of the piston 46 separates from the stepped portion 43 of the housing 40, and the piston assembly 45 moves downward within the housing 40 until the lower end surface 46a of the piston 46 contacts the lower step 41b of the housing 40.

[0083] The breaking load of the fragile pin 55 is predetermined based on the pressure of the pressurized water supplied from the working fluid supply device 18, the size of the pressure-receiving surface of the piston assembly 45 facing the pressure chamber 28, the cross-sectional area of ​​the fragile pin 55, the breaking load of the constricted portion 53, etc., so that the fragile pin 55 breaks when pressurized water at a predetermined pressure is supplied from the working fluid supply device 18 after the constricted portion 53 has broken.

[0084] As shown in Figure 11, the upper end surface of the rod 47 facing the pressure chamber 28 and the upper end surface 46b of the piston 46 become pressure-receiving surfaces that receive the pressure of the pressurized water in the pressure chamber 28. As the piston 46 moves downward within the housing 40 due to the load corresponding to the pressure acting on these pressure-receiving surfaces, the material 5 contained in the containment chamber S is pushed out into the borehole 2 by the piston 46.

[0085] The material 5, such as bentonite, extruded into the borehole 2 rapidly swells upon contact with groundwater, allowing it to backfill the borehole 2 by a predetermined amount. The material 5 contained in the containment chamber S is not limited to pelletized bentonite; any material with physical properties capable of backfilling the borehole 2 may be used. Furthermore, the material 5 may include materials that suppress contact between groundwater flowing into the housing 40 when the opening / closing door 25 is opened and the bentonite, and materials that suppress the swelling rate of the bentonite, in order to prevent the bentonite from swelling inside the housing 40.

[0086] Once the material 5 has been released, the transport unit 16 is pulled up from inside the outer tube 10 to the ground and recovered for refilling with material 5 (recovery process).

[0087] The transport unit 16 is lifted by a lifting dock of an overshot assembly (not shown), which is inserted into the outer tube 10 from above (from the ground) and moved downward, and the spearhead 65 is lifted upward as indicated by the arrow in Figure 12.

[0088] Furthermore, as the spearhead 65 is pulled upward, the cylindrical member 64 is also pulled upward, and the lower ends of the pair of slits 64a come into contact with the pair of latch portions 63. As a result, the upper ends of the pair of latch portions 63 move radially inward against the biasing force of the spring, and the locking of the pair of latch portions 63 to the locking groove 14 is released, allowing the transport unit 16 to be recovered to the ground relatively easily.

[0089] Once the transport unit 16 is recovered, the lower end position of the outer tube 10 is adjusted again according to the depth to which the material 5 is released, as shown in Figure 7(a) (adjustment step). Specifically, the outer tube 10 is raised according to the amount of material 5 released into the borehole 2. In addition, the extension pipe 11 is removed on the ground if necessary.

[0090] Once the adjustment of the lower end position of the outer tube 10 is complete, the transport unit 16 containing the material 5 in the storage chamber S is inserted back into the outer tube 10.

[0091] In this way, by using the material discharge system 100 with the above configuration, each of the above processes (adjustment process, transfer process, supply process, extrusion process, and recovery process) is repeated in sequence, and the excavated hole 2 is efficiently backfilled.

[0092] According to the above embodiments, the following effects are achieved.

[0093] According to the material discharge system 100 of this embodiment, after the downward movement of the transport unit 16 is restricted at a predetermined depth by the outer tube 10 extending along the borehole 2, the piston 46 moves downward due to the pressure of pressurized water (working fluid) supplied to the pressure chamber 28 inside the transport unit 16, and the material 5 contained in the containment chamber S is pushed out into the borehole 2 by the moved piston 46.

[0094] By providing the outer tube 10 in this manner, the inner tube 20 of the transport unit 16 does not come into contact with the wall surface of the excavation hole 2 when the transport unit 16 containing the material 5 is lowered to a predetermined depth, and when the transport unit 16 that has released the material 5 is raised for retrieval, thereby preventing the excavation hole 2 from collapsing.

[0095] This makes it possible to reliably transport and release the material 5 to a predetermined depth, and as a result, efficiently backfill the borehole 2.

[0096] Furthermore, the following modifications are also within the scope of the present invention, and it is possible to combine the configurations shown in the modifications with the configurations described in the embodiments described above, or to combine the configurations described in the following different modifications.

[0097] In the above embodiment, the piston 46 is slidably held by the housing 40. Alternatively, the piston 46 may be slidably held by the inner tube 20, as shown in the modified example in Figure 13.

[0098] In the transport unit 116 shown in Figure 13, the storage chamber S in which the material 5 is contained is partitioned by the inner circumferential surface 21a of the inner tube 20 and the lower end surface 46a of the piston 46, and the movement of the piston 46 is restricted by the lower step 21b and upper step 21c of the inner tube 20. However, this transport unit 116 is configured similarly to the transport unit 16 of the above embodiment, and comprises a cylindrical inner tube 20 formed to be movable within the outer tube 10, a piston 46 provided inside the inner tube 20, a storage chamber S partitioned inside the inner tube 20 below the piston 46 in which the material 5 is contained, and a pressure chamber 28 partitioned inside the inner tube 20 on the opposite side of the piston 46 from the storage chamber S in which the working fluid is introduced.

[0099] Therefore, in this modified example as well, when the constricted portion 53 of the fragile member 50 breaks, the piston 46 moves downward inside the inner tube 20 due to the load generated by the pressure of the working fluid in the pressure chamber 28, and the material 5 contained in the containment chamber S is pushed out into the borehole 2 by the piston 46.

[0100] In this modified example, the opening / closing door 25 is pushed open via the material 5 which is pressed downward by the piston 46. However, in order to ensure that the opening / closing door 25 is reliably opened, it is preferable to provide a rod-shaped member 49 (shown as a dashed line in Figure 13) that extends downward from the piston 46 toward the location where the fragile pin 57 is provided.

[0101] Furthermore, if there is no risk of groundwater entering the containment chamber S, it is not necessary to provide an opening / closing door 25, in which case the transport unit 116 can be made into a relatively simple configuration.

[0102] As shown in Figure 13, when using the transport unit 116, the excavated hole 2 can be backfilled efficiently, similar to the embodiment described above.

[0103] Furthermore, in the above embodiment, the limiting step 13 provided in the restricting pipe 12 of the outer tube 10 functions as a position switching unit that switches the position of the switching member 30, and also functions as a movement limiting unit that restricts the downward movement of the transport unit 16. Alternatively, the position switching unit and the movement limiting unit may be a locking groove 113 formed in a groove shape on the inner circumferential surface of the restricting pipe 12 of the outer tube 10, as shown in the modified examples from Figures 14 to 16. Figure 14 is a diagram corresponding to the state in Figure 8 described above, showing a state in which the downward movement of the transport unit 216 is restricted by the restricting pipe 12 of the outer tube 10. Figure 15 is a diagram showing an enlarged cross-section along the DD line in Figure 14, and Figure 16 shows a state in which the release of the material 5 is complete and the movement restriction of the transport unit 216 has been released.

[0104] In this modified example, the inner circumferential surface of the restricting pipe 12 is provided with a locking groove 113 formed as an annular groove, instead of the restricting step 13 in the above embodiment, and the transport unit 216 is provided with a switching member 130 that can engage with the locking groove 113, instead of the switching member 30 in the above embodiment.

[0105] As shown in Figure 15, the switching member 130 is a member with a shape that can be inserted into a passage 129 with a substantially rectangular cross-section that is formed to penetrate radially through the second cylindrical portion 22 of the inner tube 20, and is constantly biased radially outward of the second cylindrical portion 22 by an elastic member such as a spring (not shown). The passage 129 is formed in two locations opposite each other on the axis of the second cylindrical portion 22, and the switching member 130 is provided in each passage 129. Note that there may be three or more passages 129, in which case the passages 129 are evenly distributed in the circumferential direction.

[0106] Furthermore, the switching member 130 has a notched groove 131 that opens on its upper surface and on the surface facing the pressure chamber 28. As shown in Figures 14 and 15, when the switching member 130 is pressed against the bottom surface of the locking groove 113 by the biasing force of an elastic member (not shown) and engages with the locking groove 113, the pressure chamber 28 is in communication with the outside through the passage 129 and the notched groove 131, that is, it is possible to supply a working fluid such as pressurized water into the pressure chamber 28 from the outside.

[0107] On the other hand, until the switching member 130 engages with the locking groove 113, that is, while the transport unit 216 is moving downward inside the outer tube 10, it is in contact with the inner circumferential surface of the outer tube 10 and is pushed into the passage 129 by a predetermined length. The shape of the notched groove 131 that opens on the upper surface of the switching member 130 is formed so that the switching member 130 is covered by the passage 129 when it is pushed into the passage 129 by a predetermined length.

[0108] Therefore, while the transport unit 216 is moving downward inside the outer tube 10, the passage 129 is closed by the switching member 130, preventing liquids such as groundwater from flowing into the pressure chamber 28 through the passage 129. When the switching member 130 is pushed into the passage 129, a sealing member such as an O-ring may be provided on the outer surface of the switching member 130 or on the inner surface of the passage 129 to seal the gap formed between the switching member 130 and the passage 129.

[0109] Thus, the switching member 130, like the switching member 30 in the above embodiment, can switch the passage 129 from a closed state to an open state. The position of the switching member 130 switches from a closed position, where the switching member 130 closes the passage 129 by engaging with the locking groove 113 of the outer tube 10, to an open position, where the passage 129 is opened. As the position of the switching member 130 is switched in this way, the passage 129 becomes open and communicates with the notch groove 131, so the locking groove 113 functions as a position switching part that switches the position of the switching member 130.

[0110] Furthermore, the downward movement of the transport unit 216 is restricted when the switching member 130 engages with the locking groove 113. In other words, in this modified example, the locking groove 113 provided in the regulating pipe 12 functions as a position switching unit that switches the position of the switching member 130, and also functions as a movement restricting unit that restricts the downward movement of the transport unit 216. Note that a restricting step may be provided in the regulating pipe 12 below the locking groove 113 to restrict the downward movement of the transport unit 216. In this case, the switching member 130 engages with the locking groove 113 almost simultaneously with the downward movement of the transport unit 216 being restricted by the restricting step. In this case, the locking groove 113 with which the switching member 130 engages functions only as a position switching unit. Alternatively, the downward movement of the transport unit 216 may be restricted by engaging, for example, a member equivalent to the switching member with a groove formed on the inner circumferential surface of the regulating pipe 12, separate from the locking groove 113.

[0111] Furthermore, the upward movement of the transport unit 216 is also restricted by the engagement of the switching member 130 with the locking groove 113. In other words, in this modified example, the locking groove 113 provided in the regulating pipe 12 also functions as a movement restricting part that restricts the upward movement of the transport unit 216. For this reason, in this modified example, it is unnecessary to provide the above-mentioned latch portion 63 on the transport unit 216, and it is also unnecessary to form the locking groove 14 in the regulating pipe 12 with which the latch portion 63 engages. If the latch portion 63 is not provided, the lifting and lowering of the transport unit 216 may be performed by a lifting device (not shown) via a cable (not shown). However, in order to reliably restrict the upward movement of the transport unit 216, it is preferable to provide the above-mentioned latch portion 63 and the locking groove 14 with which the latch portion 63 engages.

[0112] Furthermore, a wire 136 for releasing engagement with the locking groove 113 is attached to the switching member 130. The wire 136 is, for example, a steel wire rope, and as shown in Figure 14, one end is attached to the end face of the switching member 130 facing the pressure chamber 28, and the other end is attached to the upper end of the rod 47 of the piston assembly 45.

[0113] In this manner, the wire 136 attached to the switching member 130 and the rod 47 becomes taut between the switching member 130 and the rod 47 when the fragile member 50 breaks and the piston assembly 45 moves downward.

[0114] Then, as the piston assembly 45 moves downward within the housing 40 until the lower end surface 46a of the piston 46 contacts the lower step 41b of the housing 40 (see Figure 11), the tensile force acting on the switching member 130 via the wire 136 exceeds the biasing force of a spring (not shown) acting radially outward on the switching member 130, and the switching member 130 is pulled into the pressure chamber 28 and moves away from the locking groove 113, as shown in Figure 16.

[0115] Furthermore, the path of the wire 136 is appropriately redirected by pulleys, pin members, etc., so that the force with which the piston assembly 45 pushes down the wire 136 acts on the switching member 130 along the radial direction of the second cylindrical portion 22. In addition, the length of the wire 136 is predetermined so that when the lower end surface 46a of the piston 46 comes into contact with the lower step 41b of the housing 40, the switching member 130 separates from the locking groove 113 and the engagement is released.

[0116] This releases the engagement of the switching member 130 with the locking groove 113, thereby releasing the restriction on the upward movement of the transport unit 216, making it possible to pull the transport unit 216 upward and retrieve it.

[0117] Thus, in this modified example, as in the above embodiment, the downward movement of the transport unit 216 is restricted by the locking groove 113 which functions as a movement limiting part, and the position of the switching member 130 is switched from a closed position to an open position by the locking groove 113 which functions as a position switching part, thereby guiding the working fluid to the pressure chamber 28 through the passage 129. As a result, after the downward movement of the transport unit 216 is restricted at a predetermined depth by the outer tube 10 which extends along the borehole 2, the piston 46 moves downward due to the pressure of the pressurized water (working fluid) supplied to the pressure chamber 28 inside the transport unit 216, and the material 5 contained in the containment chamber S is pushed out into the borehole 2 by the moved piston 46.

[0118] Furthermore, in the above embodiment, pressurized water is supplied to the pressure chamber 28 of the transport unit 16 through the outer tube 10, but pressurized water may also be supplied to the pressure chamber 28 through a water supply pipe directly connected to the transport unit 16. In this case, pressurized water is supplied from the working fluid supply device 18 through the water supply pipe when the transport unit 16 stops at a predetermined depth. A valve device that allows pressurized water to be supplied through the water supply pipe when the transport unit 16 stops at a predetermined depth may be provided in the water supply pipe or in the passage connecting the pressure chamber 28 and the water supply pipe in the transport unit 16.

[0119] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0120] Furthermore, in the above embodiment, the outer tube 10 is provided extending along the borehole 2, but if there is no risk of the borehole 2 collapsing, the outer tube 10 may not be provided, as shown in the reference example in Figure 17.

[0121] The material discharge system 200 in this reference example differs from the material discharge system 100 according to the above embodiment in that the outer tube 10 is not required. In Figure 17, components with the same reference numerals as in the above embodiment function in the same way.

[0122] The transport unit 316 of the material discharge system 200 shown in Figure 17 is lowered to a predetermined depth in the borehole 2 via a cable 70 and a lifting device (not shown). Pressurized water is supplied to the pressure chamber 28 of the transport unit 316 through a water supply pipe 72 directly connected to the transport unit 316.

[0123] Therefore, once it is confirmed that the transport unit 316 has been lowered to a predetermined depth by the lifting device, pressurized water is supplied from the working fluid supply device 18 through the water supply pipe 72, and then, following the same process as in the above embodiment, the material 5 contained in the containment chamber S is pushed into the borehole 2 by the piston 46.

[0124] In this reference example, compared to the above embodiment, the outer tube 10 is unnecessary, as are the passage 29 formed in the second cylindrical portion 22, the switching member 30, and the pair of latch portions 63. This reduces the cost required for backfilling the excavated hole 2. Furthermore, similar to the above embodiment, the excavated hole 2 can be backfilled efficiently. [Explanation of Symbols]

[0125] 100... Material release system 2. Drilled hole 5...Material 10. Outer tube 13. Restriction level (movement restriction section, position switching section) 16,116,216... Transport Units 18. Working fluid supply device 20... Inner tube 21b...Lower step (restriction part) 25...Opening and closing doors 28. Pressure chamber 29,129a...Aisle 30... Switching component 40.. Housing 45... Piston Assembly 46...piston 50... fragile components 55... Fragile pins 57... Fragile pin 61...Lid part 113... Locking groove (movement limiting section, position switching section) S... Confinement Chamber

Claims

1. A material discharge system that discharges material into a borehole, A cylindrical outer tube extending along the aforementioned borehole, A transport unit that is movable within the outer tube and whose downward movement is restricted by the outer tube at a predetermined depth, The transport unit is equipped with a working fluid supply device capable of supplying working fluid to the transport unit, The aforementioned transport unit is A cylindrical inner tube that can move within the outer tube, A housing is provided within the inner tube so as to be movable downward, A pressure chamber is located above the housing, within the inner tube, through which the working fluid is introduced. The lower opening of the inner tube is provided with an opening / closing door that can be opened and closed, The material is housed within the housing, The opening and closing door is pushed open by the housing, which moves downward due to the pressure of the working fluid in the pressure chamber. Material release system.

2. The transport unit further includes a switching member capable of switching the passage that guides the working fluid to the pressure chamber from a closed state to an open state. The switching member opens the passage when the downward movement of the transport unit is restricted by the outer tube. The material discharge system according to claim 1.

3. The transport unit further includes a switching member that switches between a closed position that closes the passage that guides the working fluid to the pressure chamber and an open position that opens the passage. The outer tube has a movement limiting section that restricts the downward movement of the transport unit, and a position switching section that switches the position of the switching member. The downward movement of the transport unit is restricted by the movement limiting unit, and the position of the switching member is switched from the closed position to the open position by the position switching unit, thereby guiding the working fluid through the passage to the pressure chamber. The material discharge system according to claim 1.

4. A material discharge method for releasing material into a borehole, A step of adjusting the position of the lower end of the cylindrical outer tube extending along the borehole according to the depth from which the material is discharged, A transport unit comprising a cylindrical inner tube movable within the outer tube, a housing provided within the inner tube so as to be movable downward, a pressure chamber partitioned within the inner tube above the housing and through which the working fluid is introduced, and an opening / closing door provided to open and close the lower opening of the inner tube, wherein the transport unit containing the material within the housing is inserted into the outer tube and moved downward until its downward movement is restricted by the outer tube, A step of supplying the working fluid to the transport unit, The process of pushing open the opening / closing door by moving the housing downward using the pressure of the working fluid in the pressure chamber, The process includes releasing the material inside the housing into the borehole through the lower opening, Material release method.

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