JP5058043B2 - Soil sample extraction device and extraction method - Google Patents

Description

  The present invention relates to an apparatus and method capable of taking out a soil sample from a core tube so as not to generate a compressive force, a shearing force, or the like when the soil sample taken by boring is taken out from a core tube.

  Prior to building the building, ground investigation and ground improvement are conducted. In this ground survey, and in the post survey after the ground improvement, a boring survey is conducted. In this boring survey, core boring is performed in-situ, and after observing in laboratory tests, a soil sample is taken out, and uniaxial compressive strength test and triaxial compressive test are performed as physical property tests and mechanical tests. A triaxial test is repeatedly performed to confirm the effect. In general, when a soil sample is taken out from a core tube collected from the original position, a hydraulic tube extracting device or a horizontal sample extracting device is used as an extruding device for the soil sample.

  However, when extruding a soft sample using these two devices, both of them will apply a compressive force to the soil sample in the tube, and physical property tests such as a water permeability test and strength to be performed thereafter. It may affect the results of the test and this effect cannot be ignored. Here, the soft sample means a sample collected from a low-strength ground such as sand ground or viscous soil having a low adhesive strength or a relatively high compressibility, or a ground improved to a low strength.

For example, a method and an apparatus have been proposed in which a sample cylinder is inserted into the soil, the soil sample is accommodated in the sample cylinder and collected, the sample extrusion disk is pushed in from one end of the sample cylinder, and the soil sample is pushed out from the other end. (See Patent Document 1). This apparatus is characterized in that a plurality of sample extruding discs having a predetermined thickness are prepared, and the sample extruding discs can be separated and collected according to the depth depending on the number of pushed-in sample extruding discs.
JP 2001-124672 A

  In the prior art, only means and methods for taking out soil samples by extruding from one side have been proposed, and there is an influence of turbulence during compression and sample collection, so both ends are cut off and only the center part is tested. Has been adopted as a body.

  However, as shown in FIG. 1, when the extrusion plate 1 is moved in the direction indicated by the arrow A and pushed out, the soil sample at the center also receives a compressive force, and the soil sample 2 and the tube 3 come into contact with each other. Friction occurs on the surface, and shearing force also acts in the direction indicated by the arrow B opposite to the arrow A. For this reason, even if the extrusion of the soil sample 2 is successful and the shape is not collapsed, the soil sample 2 is receiving a compressive force and a shearing force, and the water permeability and strength of the extracted soil sample 2 are underestimated or overestimated. there's a possibility that.

  For example, a soft sample with a lot of moisture or a soft soil sample becomes dense due to compression and increases its strength. Even if it is a sample with strength, if it is subjected to shearing force due to friction with the tube during extrusion, Even if the soil sample can be successfully taken out, the physical property test and strength test of the subsequent soil sample may not be performed or the strength may be lowered.

  When extruding, it is not clear that the compressive force is acting on the whole soil sample, and how much influence remains on the soil sample. In addition, the quantitative effects on soil samples have not been clarified. As described above, the conventional methods and apparatuses affect the soil sample due to the compressive force and the shearing force, and the effective take-out method and apparatus are not widely used at present.

  Therefore, it is desired to provide an apparatus and a method that can take out a soil sample without affecting the soil sample by compressive force or shear force.

  As a result of intensive studies, the present inventor does not force the soil sample collected in the tube, and does not exert any influence on the soil sample by cutting the tube at two locations simultaneously and only the tube. And found out that it can be taken out.

  By adjusting the protruding amount of the cutting member so that the cutting member such as a cutter does not reach the soil sample, cutting can be performed in a short time. Moreover, since it can cut with a cutting member in the state which fixed the tube with the exclusive groove | channel for mounting and fixing a tube, a spacer, and a fixing jig, it can cut stably.

  That is, according to the present invention, a device for taking out a soil sample accommodated in a tube, the bottom surface having a constant curvature and having a tube groove adjacent to the outer peripheral surface of the tube, for accommodating and fixing the tube There is provided an apparatus for taking out a soil sample, including a base member, a cutting member for cutting the tube, and a slider for sliding the cutting member in the longitudinal direction of the tube.

  Furthermore, in order to suppress the movement of the tube in the longitudinal direction, a pressing member disposed at both ends of the tube can be further provided. Moreover, it can also fix using a tube spacer between a tube and its pressing member.

  The slider is a slide rail including an outer rail having a rail groove and an inner rail that fits and slides in the rail groove, and either the outer rail or the inner rail is attached to the base member along the tube groove. The slide rail includes a cutting member mounting portion that extends perpendicularly to the surface of the base member and that disposes the cutting member so as to protrude from the side surface toward the tube. The other rail is attached.

  Two sliders and two cutting members are provided so as to face each other through the tube, and the two cutting member mounting portions are connected to each other by a connecting table. A nut joined to the connecting table and a hole of the nut are connected to each other. A threaded shaft extending through the threaded shaft, a plurality of balls disposed between the threaded groove of the threaded shaft and the threaded groove of the nut, and a handle attached to one end of the threaded shaft for rotating the threaded shaft in a certain direction And a ball screw. By using this ball screw, two places can be cut simultaneously.

  In the present invention, in addition to a soil sample take-out device, a soil sample take-out method can also be provided. In this method, a tube containing a soil sample is accommodated in a tube groove in which a bottom surface provided on a base member has a constant curvature and is adjacent to the outer peripheral surface of the tube, and only the tube is attached to one end of the tube. Adjusting the position of the tip of the cutting member so as to cut, and cutting the tube while sliding the cutting member in the longitudinal direction of the tube by the slider.

  The method further includes the step of disposing pressing members at both ends of the tube in order to inhibit movement of the tube in the longitudinal direction. At this time, a tube spacer can be inserted and fixed between the tube and the pressing member.

  The step of adjusting the position of the distal end portion of the cutting member includes the step of adjusting the protruding amount of the cutting member from the side surface of the cutting member attachment portion.

  In the stage of cutting the tube, by rotating the handle in a certain direction, the nut can be moved in the longitudinal direction of the screw shaft, and the two cutting members can be slid in the longitudinal direction of the tube while simultaneously cutting the tube at two locations. it can. Moreover, after cutting two places simultaneously, the tube can be rotated 90 °, and the step of adjusting and the step of cutting can be repeated, and a total of four places can be cut. This is because the soil sample housed in the tube may not be successfully removed by cutting at only two locations.

  The soil sample take-out device of the present invention can take out the soil sample as a core specimen without giving any impact, vibration, damage and breakage to the soil sample in the tube collected by core boring.

  In a general hydraulic tube extracting device or horizontal sample extracting device, a compressive force acts directly on a soil sample, but in the device and method of the present invention, compressive force, shear force, bending, etc. act directly on the soil sample. The sample can be taken out easily and safely.

  Also, by providing the slider, the tube can be cut stably and horizontally compared to manually cutting the tube, and can be cut accurately in a short time. By disposing the pressing members at both ends of the tube, the movement of the tube in the longitudinal direction can be suppressed and fixed. Further, by using a ball screw and providing two cutting members and two sliders, two tubes can be cut simultaneously, and a soil sample can be efficiently taken out.

  The soil sample taking-out apparatus and method of the present invention will be described in detail with reference to the drawings. As mentioned above, when building a building, the ground is surveyed. If the soil is contaminated, soil purification is performed. If the soil strength is insufficient, solidification materials such as cement are injected to improve the ground. Is done. Thereafter, a follow-up survey is performed to confirm whether the soil has been purified or has a predetermined strength.

  In this investigation, using a boring device, the core tube, which is a hollow circular tube, is inserted into the soil while rotating, the soil is collected in the tube, the collected soil is used as a test sample, Performed by conducting physical property tests and mechanical tests. At that time, the soil sample must be taken out from the tube, but if it is compressed during removal, accurate physical properties and mechanical properties cannot be obtained. Must be taken out. Since the soil sample take-out device of the present invention can be easily taken out from the tube without applying such force and without damaging the soil sample, accurate physical properties and mechanical characteristics can be obtained. Can do.

  2-4 is the figure which showed the structural example of the taking-out apparatus of the soil sample of this invention. 2 is a plan view, FIG. 3 is a side view thereof, and FIG. 4 is a front view thereof. This device is a device that removes a soil sample from the tube without damaging the soil sample without applying a compressive force or a shearing force to the soil sample accommodated in the tube 10, and the bottom surface has a constant curvature. A base member 12 for housing and fixing the tube 10, a cutting member 13 for cutting the tube 10, and a sliding member 13 slid in the longitudinal direction of the tube 10. And a slider 14 for making it move.

  2 to 4, in order to suppress the movement of the tube 10 in the longitudinal direction, a pressing member 15 disposed at both ends of the tube 10 is further provided, and between the tube 10 and the pressing member 15, a tube is provided. The spacer 10 is sandwiched and fixed so that the tube 10 does not move in the longitudinal direction. However, in the side view shown in FIG. 3, the tube spacer 16 is omitted for easy understanding of the shape of the tube groove 11, the position of the cutting member 13, the position of the pressing member 15, and the like.

  In this apparatus, since the tube 10 is cut by the cutting member 13, the tube 10 must be made of a material that can be easily cut by the cutting member 13. For this reason, the material of the tube 10 is preferably a plastic resin. In addition, even if it is a plastic resin, since it must be able to insert and rotate a soil sample in the soil, it must have a predetermined | prescribed intensity | strength. Therefore, hard plastic is preferable, and examples thereof include hard polyvinyl chloride, acrylic resin, polypropylene, polystyrene, and polycarbonate.

  2 to 4, the base member 12 is plate-shaped and may be made of any material such as wood, ceramics, plastic resin, steel, rubber, but the tube 10 made of plastic resin is a cutting member. A material having a frictional resistance between the tube 10 and the rubber is preferable so that the tube 10 does not move when it is cut by 13. Even if the base member 12 is not made of rubber, it can be prepared by attaching a rubber sheet to the wood or ceramics.

  The cutting member 13 can be a cutter that is tapered toward the tip and is sharpened. The cutter may have a blade on only one side so as to be cut only in one direction, or may have a blade on both sides so that it can be cut in both directions. The slider 14 may be a slide rail 17 including an outer rail having a rail groove and an inner rail that fits and slides in the rail groove. In this case, one of the outer rail or the inner rail is separated from the tube groove 11 by a predetermined distance, and is attached to the base member 12 along the tube groove 11 in parallel with the tube groove 11.

  The slide rail 17 includes a cutting member attaching portion 18 that extends perpendicularly to the surface of the base member 12 and arranges the cutting member 13 so as to protrude from the side surface toward the tube 10. The other of the outer rail and the inner rail is attached to the bottom surface of the cutting member attachment portion 18. That is, if the rail attached to the base member 12 is an outer rail, the inner rail is attached, and if the rail attached to the base member 12 is an inner rail, the outer rail is attached. These attachments can be performed with screws, adhesives, or the like.

  Two sliders 14 and two cutting members 13 are provided so as to face each other through the tube 10, and the two cutting member attachment portions 18 are connected to each other by a connection table 19 made of a steel flat plate. Note that the upper surfaces of these two cutting member attachment portions 18 are attached to both ends of one surface of the connection table 19. The cutting member mounting portion 18 can adjust the protruding amount by causing the cutter, which is the cutting member 13, to protrude toward the tube 10, or to house the cutter in the cutting member mounting portion 18 on the contrary, An adjustment screw 20 is provided for fixing the adjusted cutter. The adjustment screw 20 is screwed into a pitch screw hole, which will be described later, provided in the cutter, after the threaded hole provided in the cutting member mounting portion 18, and fixes the cutter.

  The take-out device includes a steel nut 21 joined to the center of the other surface of the connection table 19, a steel screw shaft 22 extending through the hole of the nut 21, and a screw shaft 22. A plurality of steel balls disposed between the screw groove and the screw groove of the nut 21, and a handle 23 attached to one end of the screw shaft 22 and for rotating the screw shaft 22 in a predetermined direction. A ball screw 24 is further included. As a result, the tube 10 can be simultaneously cut at two locations using the ball screw 24.

  The slider 14 is not limited to the configuration provided with the slide rail 17 described above, and includes a long and narrow groove provided in the base member 12 along the tube 10 and a protrusion provided on the bottom surface of the cutting member mounting portion 18. Or a configuration including a rail provided on the base member 12 along the tube 10 and a roller provided with a groove formed on the bottom surface of the cutting member mounting portion 18 for fitting the rail. it can.

  In addition to the nut 21, the screw shaft 22, and the ball, the ball screw 24 requires a circulating component for circulating the ball infinitely. Circulating parts are classified according to the circulation method. In this method, a tube method in which a ball is circulated by providing a tube, and a hole for scooping back the ball to end caps attached to both ends of the nut 21 are provided. The end cap system in which the scooped ball is guided to the other hole through the through hole of the nut 21 and returned from the other hole, and the ball is circulated in the nut 21. A space in which the ball can move to the adjacent screw groove in the nut 21. In other words, a top method in which a ball is circulated by providing a deflector (top) can be used.

  A method for taking out a soil sample collected in the tube 10 using the take-out apparatus illustrated in FIGS. 2 to 4 will be described in detail. First, the tube 10 is accommodated in the tube groove 11 and fixed to the base member 12. Since this base member 12 has a tube groove 11 adjacent to the outer peripheral surface of the tube 10 having a constant curvature on the bottom surface, the base member 12 is accommodated in a state in which the tube 10 is fitted in the tube groove 11 and the tube 10 is rolled. The tube 10 can be fixed to the base member 12 while being suppressed. Next, the tube spacers 16 are disposed adjacent to both ends of the tube 10 and are pressed and fixed by the pressing member 15 from the outside. Thereby, the movement to the longitudinal direction of the tube 10 is suppressed.

  Next, the protruding amount of the cutting member 13 is adjusted at one end of the tube 10. This is because the tube 10 is cut from one end to the other end. The thickness of the tube 10 is about 3 to 4 mm, and the amount of protrusion can be adjusted according to this thickness and fixed with the adjusting screw 20. By adjusting in this way, the tube 10 can be cut at once. In order not to damage the soil sample in the tube when the wall thickness of the tube 10 is large, instead of cutting at once, the cutting member 13 is protruded little by little and cut in several degrees. You can also For example, it can be adjusted to cut about 1 mm. By cutting in several degrees in this way, the risk of damage to the soil sample can be avoided, and the tube 10 can be cut without damaging the surface of the soil sample.

  The height from the surface of the base member 12 to the cutting member 13 is the same as the height from the flat surface of the base member 12 to the center of the circular tube 10 when the tube 10 is accommodated in the tube groove 11. It has been adjusted in advance. The height of the position where the cutting member 13 is attached in the cutting member attaching portion 18 can be adjusted, and at this stage, the height can be adjusted so as to be the same height as the center of the tube 10. Also in this case, the cutting member 13 can be fixed to the height after height adjustment using an adjustment screw.

  In this take-out device, it is assumed that a tube 10 having a predetermined diameter and a predetermined length is used. For example, the diameter of the tube is about 86-125 mm (3-5 inch tube) and its length is about 1 m. Some length difference can be adjusted by the tube spacer 16, but for a tube having a longer length or a tube having a different diameter, the base member 12 adapted to the size of the tube 10 is used. It is possible to cope with it.

  After adjusting the protruding amount of the cutting member 13 and fixing the cutting member 13, the handle 23 is rotated in a certain direction in order to slide the slider 14 to which the cutting member 13 is attached. A screw shaft 22 is continuous with the handle 23, and the ball accommodated in the screw groove moves with the rotation of the screw shaft 22, and accordingly, the position of the nut 21 is moved in the longitudinal direction of the tube 10. . The nut 21 is joined to the connecting table 19 by welding or the like, and the connecting table 19 also moves, and the slider 14 also moves accordingly. In this way, the cutting member 13 attached to the cutting member attachment portion 18 of the slider 14 moves and cuts the tube 10. The tube 10 is cut from one end of the tube 10 to the other end. When the tube 10 is cut by the apparatus shown in FIGS. 2 to 4, since the two cutting members 13 are arranged to face each other via the tube 10, the tube 10 is cut at two places simultaneously. .

  The screw pitch of the screw shaft 22 is determined as a pitch amount appropriate for cutting. The tube spacer 16 has a width smaller than the diameter of the tube 10. Therefore, the tube spacer 16 is not cut, and the tube 10 can be cut at an appropriate speed from one end to the other end at a time.

  In this take-out device, the ball screw 24 is cut by moving the cutting member 13 by manually rotating the handle 23. However, even if not manually, the drive motor or the like is connected to the screw shaft 22, The tube 10 can also be cut by moving the cutting member 13 at a constant speed by controlling the rotation speed. Further, by connecting a drive motor or the like to the screw shaft 22 via a torque coupling, trouble such as a failure of the device can be avoided by the torque coupling when excessive torque is generated.

  Next, the case of cutting in several times instead of cutting once will be described. The protruding amount of the cutting member 13 is adjusted by the position of the pitch screw hole provided in the cutting member 13 to which the adjusting screw 20 is screwed. As shown in FIG. 5, the cutting member 13 is provided with a plurality of pitch screw holes 25, and the protruding amount of the cutting member 13 is obtained by screwing the adjusting screw 20 into any one of the pitch screw holes 25. And the cutting member 13 can be fixed. The pitch screw holes 25 can be provided at intervals of 1 mm, for example. As long as the cutting member 13 can be fixed, a substantially conical pin or the like may be used instead of the adjusting screw 20.

  When adjusting the protruding amount of the cutting member 13, if the thickness of the tube 10 is about 3 mm, first, the cutting member 13 is protruded toward the center of the tube 10 as shown in FIG. Then, the tip of the cutting member 13 and the tube 10 are stopped at a position where they overlap each other by about 1 mm, and the adjusting screw 20 is screwed into the pitch screw hole 25 to fix the cutting member 13. Then, the handle 23 is manually rotated in a certain direction, and the tube 10 is cut from one end to the other end in the longitudinal direction. After the cutting member 13 cuts to the other end, the cutting member 13 is removed, the handle 23 is rotated in the direction opposite to the previous rotation, and the cutting member 13 is returned to one end of the tube 10 again.

  Next, as shown in FIG. 5 (b), the adjusting screw 20 is screwed into the pitch screw hole 25 on the one outer side, and is stopped at a position where the tip of the cutting member 13 and the tube 10 overlap each other by about 2 mm, The adjusting screw 20 is screwed into the pitch hole 25 to fix the cutting member 13. Then, the handle 23 is manually rotated in a certain direction, and the tube 10 is cut from one end to the other end in the longitudinal direction. After the cutting member 13 cuts to the other end, the cutting member 13 is removed, the handle 23 is rotated in the direction opposite to the previous rotation, and the cutting member 13 is returned to one end of the tube 10 again.

  Next, as shown in FIG. 5 (c), the adjusting screw 20 is screwed into the pitch screw hole 25 on the further outer side, and is stopped at a position where the tip of the cutting member 13 and the tube 10 overlap each other by about 3 mm. The cutting screw 13 is fixed by screwing the adjustment screw 20 into the pitch hole 25. Then, the handle 23 is manually rotated in a certain direction, and the tube 10 is cut from one end to the other end in the longitudinal direction.

  Thus, by cutting in several times, it is possible to reliably take out the soil sample as an internal test body without damaging it. Since the two cutting members 13 are provided facing each other, the tube 10 can be cut into two by cutting in this way. The soil sample can be taken out by removing the upper tube of the cut tube 10 and rotating the tube 10 about 180 ° to remove the lower tube.

  In this case, when removing the upper tube, it is performed while putting air between the soil sample and the upper tube, but the upper tube must be shifted slightly. However, this takes time.

  When the strength of the soil sample accommodated in the tube 10 is sufficient, even if some force is applied when removing the upper tube, there is almost no influence on the soil sample, but as shown in FIG. When the upper tube 10a is removed, if it is slid in the direction of the arrow C, the shear force acts on the soil sample 27 in the direction indicated by the arrow D even if the force is slight. Therefore, it is preferable to avoid it as much as possible.

  Therefore, first, after cutting two places, the tube 10 is rotated about 90 °, and further, two places are cut simultaneously, and a total of four places are cut. By finely cutting in this way, air easily enters between the soil sample and the tube 10, and the tube 10 is easily removed from the soil sample. As a result, the soil sample can be taken out without affecting the soil sample. However, since it becomes difficult to cut the tube 10 when the number to be cut increases, it is preferable to cut about 3 to 8 places.

  First, as shown in FIG. 7A, two cutting members 13 facing each other through the tube 10 are simultaneously cut in the longitudinal direction of the tube 10. Next, the tube 10 is rotated by approximately 90 ° and fixed, and as shown in FIG. 7B, two cutting members 13 facing each other through the tube 10 are simultaneously cut in the longitudinal direction of the tube 10. . In this way, as shown in FIG. 7C, the tube segment 26a having a size of about ¼ can be easily detached without applying much force. Similarly, the tube segment 26b having a size of about 1/4 can be removed. Thereafter, the soil sample is gently rotated about 90 °, the tube piece 26c is removed, and further, the soil sample is gently rotated about 90 °, the tube piece 26d is removed, and the compressive force and shear are not damaged without damaging the soil sample. It can be taken out without receiving power.

  The soil sample taking-out apparatus and method of the present invention have been described in detail with reference to the embodiments shown in the drawings so far, but the present invention is not limited to the above-described embodiments, and other embodiments are described. It is possible to make modifications within the scope that can be conceived by those skilled in the art, such as forms, additions, changes, and deletions, and any aspect is included in the scope of the present invention as long as the effects and effects of the present invention are exhibited. is there. This apparatus and method can be applied not only to a low-strength soil sample but also to a soil sample of any strength, and the tube 10 is not limited to an even number such as two or four. It can also be cut to odd numbers.

The figure which showed the place which put out the extrusion board in the conventional tube, pushed out the extrusion board, and took out the soil sample. The top view which showed the structural example of the taking-out apparatus of the soil sample of this invention. The side view which showed the structural example of the taking-out apparatus of the soil sample of this invention. The front view which showed the structural example of the taking-out apparatus of the soil sample of this invention. The figure which showed the place which is adjusting the protrusion amount of a cutting member. The figure which showed the place where a shear force acts on a soil sample, when removing an upper side tube. The figure which showed the place which cuts the tube 4 places.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Extrusion board, 2 ... Soil sample, 3 ... Tube, 10 ... Tube, 11 ... Tube groove, 12 ... Base member, 13 ... Cutting member, 14 ... Slider, 15 ... Holding member, 16 ... Tube spacer, 17 ... Slide Rail, 18 ... Cutting member mounting portion, 19 ... Connection table, 20 ... Adjustment screw, 21 ... Nut, 22 ... Screw shaft, 23 ... Handle, 24 ... Ball screw, 25 ... Pitch screw hole, 26a to 26d ... Tube fragment 27 ... Soil samples

Claims (10)

An apparatus for taking out a soil sample contained in a tube,
A base member for accommodating and fixing the tube, the bottom surface having a constant curvature and having a tube groove adjacent to the outer peripheral surface of the tube;
A cutting member for cutting the tube;
An apparatus for taking out a soil sample, comprising: a slider for sliding the cutting member in the longitudinal direction of the tube.   The apparatus according to claim 1, further comprising pressing members disposed at both ends of the tube to inhibit movement of the tube in the longitudinal direction.   The slider is a slide rail that includes an outer rail having a rail groove and an inner rail that fits and slides into the rail groove, and one of the outer rail or the inner rail extends along the tube groove to the base. The device according to claim 1 or 2, wherein the device is attached to a member.   The slide rail includes a cutting member mounting portion that extends perpendicularly to the surface of the base member and disposes the cutting member so as to protrude from the side surface toward the tube, and is provided on a bottom surface of the cutting member mounting portion. The apparatus of claim 3, wherein the other of the outer rail or the inner rail is attached. The slider and the cutting member are provided two by two so as to face each other through the tube, and the two cutting member attachment portions are connected to each other by a connection table,
The soil sample take-out device is arranged between a nut joined to the connection table, a screw shaft extending through the hole of the nut, and a screw groove of the screw shaft and a screw groove of the nut. A ball screw comprising: a plurality of balls, and a handle attached to one end of the screw shaft and for rotating the screw shaft in a certain direction;
The apparatus according to claim 4 , wherein the tube is cut at two locations simultaneously using the ball screw. A method for taking out a soil sample contained in a tube,
The tube containing the soil sample is stored and fixed in a tube groove adjacent to the outer peripheral surface of the tube having a constant curvature on the bottom surface provided on the base member;
Adjusting the position of the tip of the cutting member so as to cut only the tube at one end of the tube;
Cutting the tube while sliding the cutting member in the longitudinal direction of the tube with a slider.   The method according to claim 6, further comprising disposing pressing members at both ends of the tube to inhibit movement of the tube in the longitudinal direction. The slider is a slide rail including an outer rail having a rail groove and an inner rail that fits and slides in the rail groove, and the slide rail extends perpendicularly to the surface of the base member, and has a side surface. A cutting member mounting portion for disposing the cutting member so as to protrude from the tube toward the tube,
The method according to claim 6 or 7, wherein the step of adjusting the position of the distal end portion of the cutting member includes the step of adjusting a protruding amount of the cutting member from a side surface of the cutting member attachment portion. The slider and the cutting member are provided two by two so as to face each other through the tube, and the two cutting member mounting portions are connected to each other by a connecting table, and a nut is joined to the connecting table. A screw shaft is inserted into the hole of the nut, a plurality of balls are disposed between the screw groove of the screw shaft and the screw groove of the nut, and the screw shaft is disposed at one end of the screw shaft. A handle for rotating in a certain direction is provided,
In the step of cutting the tube, the handle is rotated in a certain direction to move the nut in the longitudinal direction, and the two cutting members are slid in the longitudinal direction, and the tube is moved in two places. The method according to claim 8 , wherein cutting is performed simultaneously.   The method according to claim 9, further comprising the step of rotating the tube 90 degrees after cutting the two locations simultaneously, and repeating the adjusting step and the cutting step.

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