JP2009150095A - Bottom enlarged bucket - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bottom enlarged bucket capable of preventing a rod from being worn and reducing cost of maintenance of the bottom enlarged bucket. <P>SOLUTION: In this bottom enlarged bucket, a thruster 50 moves and reciprocates in the longitudinal direction (vertical direction (not shown) in Fig.2) of the rod 40 and is provided with a thruster inner 53 constituted into a cylindrical shape by using rolled steel for general structure (SS400). The thruster inner 53 is externally fitted into the rod 40 constituted by carbon steel for mechanical structure (S45C). For this reason, since the thruster inner 53 is more worn than the rod 40, wear of the rod 40 is suppressed. Since the worn thruster inner 53 has a simpler shape when compared with a shape of the rod 40, manufacturing cost of the thruster inner 53 is suppressed to low cost. Consequently, product cost of the thruster inner 53 to be replaced is suppressed to low cost. As a result, cost of maintenance of the bottom enlarged bucket can be reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bottom expansion bucket, and more particularly to a bottom expansion bucket that can prevent rod wear and reduce maintenance costs for the bottom expansion bucket.

  2. Description of the Related Art Conventionally, a bottom-up bucket used for constructing a pile with an enlarged tip shape is known. For example, in Japanese Patent Publication No. 63-65797, a slider (thruster) 15 externally fitted to a prism 12 (rod) 12 is moved up and down by a hydraulic cylinder (part of a lifting mechanism) 13 to move the slider 15. A technique relating to a bottom expansion bucket that is transmitted to an expansion blade (bottom expansion blade) 32 via a link 16 and performs expansion or contraction operation of the expansion blade 32 is described.

  The bottom expansion bucket 11 is lowered from the ground surface toward the lower part of the vertical hole with the diameter of the expansion blade (bottom expansion blade) 32 being reduced, and the slider (thruster) 15 is moved to the hydraulic cylinder (one of the lifting mechanisms) at the lower part of the vertical hole. Part) 13 is lowered and the bottom of the vertical hole is excavated by rotating the bottom expansion bucket 11 while expanding the expansion blade 32 via the link 16 to form a space of a predetermined diameter in the lower part of the vertical hole. To do.

Thereafter, the diameter reduction operation of the expansion blade (bottom expansion blade) 32 is performed, and the excavated mud is accommodated in the case (main body portion) 30 and then pulled up from the lower portion of the vertical hole to the ground surface (Patent Document 1).
Japanese Examined Patent Publication No. 63-65797 (Column 5, lines 29 to 36)

  Here, the slider (thruster) 15 is externally fitted on a prism 12 (rod) disposed inside the case (main body part) 30 and slides in the vertical direction inside the case (main body part) 30. It is possible.

  However, since the excavated mud is accommodated in the case (main body portion) 30, mud is placed in the sliding gap between the slider (thruster) 15 and the prism (rod) 12 disposed therein. And the slider (thruster) 15 and the prism (rod) 12 were worn.

  Therefore, the fitting between the slider 15 and the prism 12 is loosened, the positional accuracy of the enlarged blade (bottom blade) 32 attached to the slider 15 via the link 16 is lowered, and it becomes difficult to obtain the targeted bottom diameter. It was.

  As a result, in order to maintain the positional accuracy of the expansion blade (bottom expansion blade) 32, it is necessary to periodically replace the slider (thruster) 15 and the prism (rod) 12, and the maintenance cost of the bottom expansion bucket 11 increases. was there.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a bottom expansion bucket that can prevent rod wear and reduce the maintenance cost of the bottom expansion bucket.

  In order to achieve this object, the bottomed bucket according to claim 1 is inserted into a vertical hole having a constant cross section excavated in the ground, and the bottom of the vertical hole is rotated in order to expand the diameter of the bottom of the vertical hole. A bottom expansion bucket for excavation, a main body portion, a bottom expansion blade that is rotatably connected to the main body portion, a rod that has an axial center and is configured in a columnar shape, and a rod that is disposed inside the main body portion A thruster that is externally fitted to the rod and reciprocally moved along the axis of the rod, an actuator that applies a driving force for reciprocating the thruster, and the thruster and the bottom wing are coupled to each other. The thruster comprises a thruster main body configured in a cylindrical shape and through which the rod is inserted, and a thruster inner disposed between the thruster main body and the rod, The thrust tie Na is detachably attached to the thruster body portion with constituted by the rod of the outer surface configuration to lower hardness than the material the material a.

  According to a second aspect of the present invention, in the widened bucket according to the first aspect, the thruster inner is formed in a cylindrical shape that is fitted into the thruster body and fitted to the rod.

  The widened bucket according to claim 3 is the widened bucket according to claim 1 or 2, wherein the rod includes a sliding portion where the thruster inner slides and a pair of extensions coupled to both ends of the sliding portion. The sliding part is made of a material having higher hardness than the pair of extended parts.

  According to the widened bucket according to claim 1, the driving force is applied from the actuator to the thruster that is lowered to the bottom of the vertical hole and is externally fitted to the rod, so that the thruster is externally fitted to the rod. The widened wing reciprocated along the axis and expanded in diameter by the forward movement of the thruster is rotated at the bottom of the vertical hole, and the vertical hole is excavated and expanded in diameter by the expanded wing. Then, the diameter of the bottom wing is reduced by the return movement of the thruster, and the excavated mud is accommodated in the main body by the bottom wing and pulled up from the bottom of the vertical hole.

  According to the first aspect of the present invention, the thruster includes a thruster body portion that is configured in a cylindrical shape and through which the rod is inserted, and a thruster inner disposed between the thruster body portion and the rod. Since the thruster inner is made of a material whose hardness is lower than that of the material constituting the outer surface of the rod, seizure caused by sliding between the rod and the thruster inner can be suppressed, and the number of rod replacements can be reduced. it can. Therefore, there is an effect that the maintenance cost of the bottom expansion bucket can be reduced.

  Furthermore, since the thruster inner is configured to be detachable with respect to the thruster body, the thruster inner that slides against the rod is worn to prevent the rod from being worn, and only the worn thruster inner is replaced. Can do.

  Therefore, compared with the case where both the rod and the thruster main body are replaced, the number of parts to be replaced can be reduced to one, so that the replacement part cost can be kept low. As a result, there is an effect that the maintenance cost of the bottom expansion bucket can be reduced.

  According to the widened bucket of claim 2, in addition to the effect produced by the widened bucket of claim 1, the thruster inner is configured in a cylindrical shape that is fitted into the thruster body and fitted to the rod. Therefore, since the load applied to the thruster inner from the rod can be received by the thruster inner and the thruster main body, the strength of the thruster can be efficiently ensured.

  According to the third aspect of the present invention, in addition to the effect produced by the first and second aspect of the present invention, the rod is connected to the sliding portion where the thruster inner slides and to both ends of the sliding portion. When the entire rod is made of a material having high hardness, the sliding portion is made of a material having a higher hardness than the pair of extension portions. In comparison, the manufacturing cost of the rod can be suppressed and the product cost of the rod can be reduced. Therefore, there is an effect that the product cost of the bottomed bucket can be reduced.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. First, with reference to FIG. 1, the earth drill machine 1 provided with the bottom expansion bucket 19 is demonstrated. FIG. 1 is a side view showing a side surface of the earth drill machine 1 according to the first embodiment of the present invention, and shows a state in which the bottom expansion bucket 19 is expanded in order to facilitate understanding.

  As shown in FIG. 1, the earth drill machine 1 of 1st Embodiment performs the operation | work which excavates the bottom expansion hole for shape | molding a bottom expansion pile, Specifically, the bottom part of the excavated vertical hole A space having a diameter larger than that of the vertical hole is excavated. This excavation work is a process of the earth drill method. By excavating only the bottom part with a large diameter, the excavation work can be saved compared to the case of excavating the entire vertical hole with a large diameter, thereby shortening the construction period and cost. Is possible.

  As shown in FIG. 1, the earth drill machine 1 mainly stands with respect to a lower main body 11 that can travel, an upper revolving body 12 that can turn with respect to the lower main body 11, and the upper revolving body 12. Boom 13 mounted in a state, a front frame portion 14 provided on the boom 13, a rod-like kelly bar 15 suspended from the upper part (the upper end in FIG. 1) of the boom 13, and the kerry bar 15 being driven to rotate. And a hydraulic hose (not shown) for supplying oil to a pair of hydraulic actuators 21 (see FIG. 2), which will be described later, connected to the lower part of the kelly bar driving device 16 and connected to the front frame portion 14. A hose reel 17 that winds or unwinds, a hose reel base 18 on which the hose reel 17 is mounted, and a lower tip of the kelly bar 15 (lower in FIG. 1) And a rotary joint 20 that supplies oil at the bottomed bucket 19 side and the kellybar driving device 16 side. Yes. The rotary joint 20 is provided to supply hydraulic pressure to a hydraulic actuator 21 (see FIG. 2A) provided on the bottom expansion bucket 19.

  The rotary joint 20 is composed of a non-rotating outer cylinder fixed to the hose reel base 18 and an inner cylinder that is rotatably fitted inside the outer cylinder, and between the outer cylinder and the inner cylinder. A groove-shaped flow path is formed in the upper surface. Note that the rotation of the inner cylinder rotates as the kelly bar 15 is rotated by the kelly bar driving device 16.

  Next, the configuration of the bottomed bucket 19 will be described with reference to FIG. FIG. 2A is a side view of the bottomed bucket 19 in a reduced diameter state, and FIG. 2B is a side view of the bottomed bucket 19 in a state of increased diameter. FIG.2 (c) is sectional drawing of the bottom expansion bucket 19 in the IIc-IIc line | wire of FIG.2 (b).

  2A and 2B, a part of the link 70 is shown by a two-dot chain line for the sake of simplicity. Moreover, the dashed-two dotted line of FIG.2 (c) has shown the bottom expansion bucket 19 of the diameter-reduced state shown to Fig.2 (a). 2A is a side view from the direction of arrow IIa shown in FIG. 2C, and the side view of FIG. 2B is from the direction of arrow IIb shown in FIG. 2C. FIG.

  As shown in FIGS. 2 (a) and 2 (b), the bottom-expanded bucket 19 is lowered to the bottom of the excavated vertical hole and rotates while the kelly bar 15 (see FIG. 1) rotates. Then, the sand is excavated while expanding the bottom wing 60 by the extension of the hydraulic actuator 21, and the excavated earth and sand is pulled up by reducing the diameter of the bottom wing 60 by shortening the hydraulic actuator 21, and is pulled up. Thus, the diameter of the bottom of the vertical hole is increased.

  In addition, when it is necessary to excavate a space having a volume larger than the volume of earth and sand accommodated in the frame body 30, a plurality of ascending and descending operations are performed, and the diameter of the expanded hole is gradually enlarged. During excavation, a bentonite stabilizing liquid is filled in the excavation hole for the purpose of preventing the side surface of the vertical hole from collapsing.

  2 (a), 2 (b), and 2 (c), the bottom expansion bucket 19 is a frame having a rectangular outer shape mainly when viewed from the side (viewed in the vertical direction in FIG. 2 (a)). A frame body 30 configured as follows, a pair of widened wings 60 that are disposed on both sides of the frame body 30 (left and right sides in FIG. 2B) and excavate a widened hole, and the frame body 30 and a pair of widened wings 60 And a shaft F (see FIG. 3) that is pivotably coupled to the pair of bottom expanded blades 60 with respect to the frame 30, and the upper portion of the frame 30 (see FIG. a) A rod 40 configured in a cylindrical shape that is fitted to the upper portion and is locked to the frame 30 by the pin P, and is fitted on the rod 40 in the longitudinal direction (vertical direction in FIG. 2). The thruster 50 that can be reciprocated, and the thruster 50 and the upper part of the frame body 30 (upper part of FIG. 2A) are connected. The hydraulic actuator 21 that reciprocates the thruster 50 by expanding and contracting in the longitudinal direction of the rod 40 by the hydraulic pressure of oil supplied from the rotary joint 20 via the hydraulic pipe 22, and reciprocatingly moved by the hydraulic actuator 21. A link 70 is provided between the thruster 50 and the expanded bottom blade 60 to open and close the expanded bottom blade 60 in conjunction with the reciprocating movement of the thruster 50.

  As shown in FIGS. 2B and 2C, when the hydraulic actuator 21 is extended by the hydraulic pressure transmitted from the hydraulic piping 22, the thruster 50 is lowered (moved downward in FIG. 2B). Then, the diameter of the bottom expanded blade 60 is expanded via the link 70. On the other hand, when the hydraulic actuator 21 is shortened by the hydraulic pressure transmitted from the hydraulic pipe 22, the thruster 50 rises (moves upward in FIG. 2A), and the bottom expanded blade 60 is moved via the link 70. The diameter is reduced.

  Next, with reference to FIG.3 and FIG.4, the connection structure of the bottom expansion blade 60 and the frame 30 is demonstrated. FIG. 3 is an enlarged side view of the bottom expanded blade 60 and the frame 30 in which the portion indicated by III in FIG. FIG. 4A is a partial cross-sectional view showing a part of a cross section of the bottom expanding blade 60 and the frame body 30 along the IVa-IVa line in FIG. 3, and the frame body pipe 32 welded to the frame body 30 is illustrated. Has been. In FIG. 3, the positions of the welded portions on the outer periphery of the frame body collar 35 and the bottom wing collar 65 are indicated by a group of straight lines shown on the outer periphery of the frame body collar 35 and the bottom wing collar 65.

  FIG. 4B is a partial cross-sectional view showing a part of the cross section of the bottom expanding blade 60 and the frame body 30 along the line IVb-IVb in FIG. 3, and the bottom expanding blade pipe 63 welded to the bottom expanding blade 60. Is shown. 4A and 4B, the positions of the welded portions on the outer periphery of the frame collar 35 and the bottom wing collar 65 are represented by a group of straight lines that are shown on the outer periphery of the frame collar 35 and the bottom wing collar 65. Show.

  As shown in FIG. 3 and FIG. 4A, the frame body 30 and the bottom expanded wing 60 are connected by a shaft F so as to be rotatable.

  The frame 30 has a quadrangular shape when viewed from the side (FIG. 2A, viewed in the direction perpendicular to the paper surface), and the outer peripheral surface 30a of the vertical frame is configured to have an arc shape when viewed from the top. (See FIG. 2 (a) and FIG. 2 (c)).

  As shown in FIG. 4 (a), the frame 30 has a base 31 welded to the inside of the outer peripheral surface 30a and configured in an L-shaped cross section, and a plurality (first embodiment) attached to the base 31 by welding. In this embodiment, three frame hinges 32 and a plurality (six in the first embodiment) frame collars 35 are provided.

  The frame collar 35 is formed in a flat plate shape having a circular outer shape in plan view, and has a frame color hole 35a that is a through hole having a circular outer shape in plan view and a concentric circle in plan view.

  As shown in FIG. 4A, the frame hinge 32 includes a frame pipe 33 (see FIG. 3) configured in a cylindrical shape, and a frame pipe reinforcement portion 34 welded to the frame pipe 33. ing. The frame pipe reinforcement 34 is welded to the pedestal 31, and a frame collar 35 is tack welded to both end faces (upper and lower end faces in FIG. 3) of the frame pipe 33.

  As shown in FIG. 4, tack welding is welding in which welded portions and non-welded portions are alternately arranged, and the welded portion W is a frame body color in the circumferential direction centering on the axis of the frame body pipe 33. It is disposed in the range of 45 degrees along the outer periphery of 35. The welded portions W are arranged at four positions shifted by 90 degrees in the circumferential direction around the axis of the frame pipe 33. Therefore, compared to welding the entire circumference of the frame collar 35, the welding time for attaching the frame collar 35 and the fusing time for removing the frame collar 35 can be shortened. Therefore, since the welding (melting) energy cost required for welding the frame collar 35 and the labor cost of the welding operator can be reduced, the maintenance cost of the bottomed bucket 19 can be reduced.

  As shown in FIG. 3, a plurality of (three in the first embodiment) frame hinges 32 are arranged at predetermined intervals in the axial direction of the frame pipe 33 (the vertical direction in FIG. 3). An expanded bottom hinge 62 described later is disposed between the frame hinges 32.

  The widened wing 60 has a triangular shape when viewed from the side (FIG. 2B, viewed in the direction perpendicular to the plane of the paper) and an arc shape when viewed from above (FIG. 2C, viewed in the direction perpendicular to the plane of the paper). 2 (c)), a plurality of excavation blades 61 attached to the triangular hypotenuse 60a and a plurality of excavation blades 61 attached to the machining surface 60b opposite to the excavation blade 61 (right side in FIG. 3) (first embodiment) (4 in the embodiment) and a plurality (eight in the first embodiment) of the expanded wing collars 65.

  The widened wing collar 65 is formed in a flat plate shape having a circular outer shape in plan view, and has a widened wing collar hole 65a that is a through hole having a circular outer shape in plan view and a concentric circle in plan view.

  As shown in FIG. 4B, the bottom wing hinge 62 includes a bottom wing pipe 63 configured in a cylindrical shape and a bottom wing pipe reinforcing portion 64 welded to the bottom wing pipe 63. The bottom wing pipe reinforcing portion 64 is welded to the bottom wing blade 60, and the bottom wing collar 65 is tack welded to both end faces (upper and lower end faces in FIG. 3) of the bottom wing pipe 63. Therefore, as in the case of the frame collar 35, it is possible to reduce the welding (melting) energy cost and the labor cost of the welding operator required for welding the bottom expanding blade collar 65, thereby reducing the maintenance cost of the bottom expanding bucket 19. be able to.

  As shown in FIG. 3, a plurality (four in the first embodiment) of expanded bottom wing hinges 62 are arranged at predetermined intervals in the axial direction (upward and downward direction in FIG. 3) of the expanded wing pipe 63. The above-described frame hinge 32 is disposed between the expanded wing pipes 63.

  The shaft F is fitted into the alternately arranged frame hinges 32 and expanded wing hinges 62, thereby forming a hinge structure and the expanded wings 60 can be rotated with respect to the frame 30. . The upper end and the lower end of the shaft F are screwed together with retaining caps C configured in a flange shape, and by sandwiching the uppermost and lowermost widening blade collars 65 of the hinge structure at the flange portions, The shaft F is prevented from coming off in the vertical direction (the vertical direction in FIG. 3).

  For example, in the case where the same number of bottom wing hinges 62 and frame hinges 32 are provided, when the frame hinges 32 are disposed at the top, the frame hinges 32 and the bottom wing hinges 62 are alternately disposed. Therefore, the lowermost portion is the expanded wing hinge 62. In that case, when the gap between the frame hinge 32 and the expanded wing hinge 62 is large, the position of the expanded wing hinge 62 is lowered with respect to the frame hinge 32. Accordingly, the bottom C of the bottom wing collar 65 (hereinafter referred to as the “bottom bottom wing collar”) welded to the lower end of the bottom wing hinge 62 disposed at the lowermost portion is screwed to the lower end of the shaft F. Pressed against.

  Therefore, the weight of the bottom expanded wing 60 is applied to the stopper C at the lower end, and a downward force is applied to the shaft F. A frame collar 35 (hereinafter referred to as “uppermost frame color”) welded to the upper surface of the frame hinge 32 provided with a stopper C screwed to the upper end of the shaft F by the downward force. ).

  Therefore, when the bottom wing 60 rotates with respect to the frame 30, the lowermost bottom wing collar rotates with respect to the uppermost frame collar, so that a pair of pull-outs integrated with the shaft F are integrated. Stop C slides with respect to either the bottom bottom wing collar or the top frame collar or both. As a result, the lowermost widened wing collar and the uppermost frame color are worn.

  On the other hand, according to the first embodiment, the expanded wing 60 includes the four expanded wing hinges 62, and the frame 30 includes the three frame hinges 32. When the 62 and the frame hinges 32 are alternately arranged, the expanded wing hinges 62 are arranged at the uppermost part and the lowermost part of the hinge structure. The shaft F has a bottom expansion collar 65 (hereinafter referred to as the “top bottom expansion collar”) welded to the upper surface of the top bottom expansion blade hinge 62 and a bottom bottom expansion collar, which is narrowed through a retaining C. It becomes the composition to have.

  Therefore, even if the gap between the frame hinge 32 and the expanded wing hinge 62 is large, the shaft F and the retaining ring C hold the expanded wing hinge 62 disposed at the uppermost portion and the lowermost portion. Thus, it moves together with the expanded wing 60.

  Therefore, even if the bottom wing 60 rotates with respect to the frame body 30, the pair of retaining stoppers C does not slide with respect to the top bottom wing collar and the bottom bottom wing collar. Further, the dead weight of the bottom wing 60 is applied to the frame collar 35 welded to the upper end of the frame pipe 33 through the bottom wing collar 65 welded to the lower end of the bottom wing pipe 63, so that the shaft F and the retaining C In this case, the weight of the bottom expanded wing 60 is not applied.

  As a result, since the bottom bottom wing collar and the top bottom wing collar are not worn, the hardness of the bottom bottom wing collar and the top bottom wing collar can be reduced with respect to the other bottom wing collar 65. .

  Further, when the frame hinge 32 is disposed at the uppermost part and the lowermost part of the hinge mechanism in place of the expanded wing hinge 62, it is disposed at the lowermost part in the same manner as when the expanded wing hinge 62 is disposed. A frame collar 35 (hereinafter referred to as “lowermost frame color”) that is welded to the lower end of the frame hinge 32, and the uppermost frame collar will not be worn. Thus, the hardness of the lowermost frame color and the uppermost frame color can be reduced.

  Thus, the frame body hinges 32 and the bottom expanded wing hinges 62 are alternately arranged in the axial direction (vertical direction in FIG. 3), so that the frame body 30 has an upper end surface (FIG. 3). The weight of the bottom expansion blade 60 is supported by the frame collar 35 that is tack-welded to the upper surface.

  On the other hand, the bottom wing 60 supports the weight of the bottom wing 60 by a bottom wing collar 65 that is tack-welded to the lower end surface (lower surface in FIG. 3) of the bottom wing pipe 63. Therefore, since the frame collar 35 and the bottom wing collar 65 are in contact with each other, it is possible to prevent the bottom end surface of the bottom wing pipe 63 and the top end surface of the frame body pipe 33 from contacting each other. As a result, by wearing the bottom expanding blade collar 65 and the frame collar 35, it is possible to prevent the bottom expanding blade pipe 63 and the frame pipe 33 from being worn.

  Therefore, unlike the conventional case, there is no need to replace the bottom wing pipe 63 and the frame body pipe 33, and only the bottom wing collar 65 and the frame body 35 need to be replaced, so that the labor of replacement can be saved. Therefore, the maintenance cost of the bottomed bucket 19 can be reduced.

  The bottom wing collar 65 and the frame collar 35 are welded to the end faces of the bottom wing pipe 63 and the frame pipe 33, and the welding strength of the bottom wing collar 65 and the frame collar 35 is respectively the bottom wing pipe 63. As long as it does not rotate relative to the frame pipe 33, it is simpler than the welding of the bottom wing pipe 63 and the frame pipe 33 to the bottom wing 60 and the frame 30 (the amount of welding penetration is reduced). Less).

  Therefore, it is possible to save the labor of welding for attaching the bottom wing collar 65 and the frame collar 35. Furthermore, since the bottom wing collar 65 and the frame collar 35 are attached by simple welding, the time and labor of fusing to remove the bottom wing collar 65 and the frame collar 35 can be saved. Therefore, since the trouble of exchanging the bottom expanding blade collar 65 and the frame collar 35 can be saved, the maintenance cost of the bottom expanding bucket 19 can be reduced.

  The bottom wing pipe 63 and the frame body pipe 33 are members for rotating the bottom wing 60 and the frame body 30 and need to be inserted through the shaft F. Therefore, when the bottom wing pipe 63 and the frame body pipe 33 are replaced, it is necessary to accurately determine the respective positions where the bottom wing pipe 63 and the frame body pipe 33 are welded with respect to the bottom wing blade 60 and the frame body 30. It takes time and effort.

  On the other hand, according to the first embodiment, since the bottom wing collar 65 and the frame collar 35 are exchanged, the bottom wing collar 65 and the frame collar 35 can be easily positioned. That is, since the bottom wing collar 65 and the frame collar 35 are members attached to the already-installed bottom wing pipe 63 and the frame body pipe 33, the mounting positions of the bottom wing collar 65 and the frame collar 35 are the bottom expansion. The holes of the bottom wing collar 65 and the frame collar 35 on the end faces of the wing pipe 63 and the frame body pipe 33 may be located at positions corresponding to the bottom wing pipe 63 and the frame body pipe 33. As compared with the case where each is positioned with respect to the bottom expanding blade 60 and the frame 30, the positioning of the bottom expanding blade collar 65 and the frame collar 35 can be facilitated.

  Therefore, it is possible to save the trouble of attaching the bottom expanding blade collar 65 and the frame collar 35, and therefore the maintenance cost of the bottom expanding bucket 19 can be reduced. Thus, since the bottom wing collar 65 and the frame body collar 35 are attached, the labor for attachment can be saved compared with the case where the bottom wing pipe 63 and the frame body pipe 33 are attached. Therefore, the maintenance cost of the bottomed bucket 19 can be reduced.

  Also, since the bottom wing collar 65 and the frame collar 35 are attached to the end face of the bottom wing pipe 63 and the end face of the frame pipe 33 by welding, processing such as bolt holes and bolts for attachment can be omitted. It is possible to reduce the processing cost and attachment parts cost for attaching the bottom expanding blade collar 65 and the frame collar 35. Therefore, the product cost of the bottomed bucket 19 can be reduced.

  Further, since a material with high hardness and high material cost can be used only for the bottom wing collar 65 and the frame body collar 35, compared with the case where a high hardness material is used for the bottom wing pipe 63 and the frame body pipe 33. Thus, the product cost of the bottomed bucket 19 can be reduced.

  Further, the bottom wing collar 65, the frame body collar 35, the bottom wing pipe 63, and the frame pipe 33 are made of a carbon steel material for machine structural use (S45C) that has been subjected to quenching. The strength of the bottom wing collar 65 and the frame collar 35 is set higher than that of the bottom wing pipe 63 and the frame pipe 33.

  Therefore, since the bottom wing collar 65 and the frame collar 35 have higher hardness than the bottom wing pipe 63 and the frame pipe 33, compared with the case where the end face of the bottom wing pipe 63 and the end face of the frame pipe 33 are brought into contact with each other. The amount of wear of the bottom wing collar 65 and the frame collar 35 can be suppressed, and the number of replacements of the bottom wing collar 65 and the frame collar 35 can be reduced. Therefore, the maintenance cost of the bottomed bucket 19 can be reduced.

  In addition, as described above, tack welding can reduce the entire welding amount as compared to the case where the outer periphery is welded all around.

  For this reason, the hardened material of the bottom wing collar 65 and the frame body color 35 can reduce the amount of heat transmitted to the bottom wing collar 65 and the frame body color 35 due to the small number of welds. It is possible to minimize the change in hardness that occurs when the frame collar 35 is annealed.

  Therefore, the hardness of the bottom wing collar 65 and the frame collar 35 can be stabilized, so that the wear of the bottom wing collar 65 and the frame collar 35 can be stabilized. As a result, since it is possible to easily predict the replacement timing of the bottom expanding blade collar 65 and the frame collar 35, it is possible to easily estimate the maintenance cost of the bottom expanding bucket 19.

  Next, the configuration of the thruster 50 will be described with reference to FIGS. 5A is a top view of the thruster 50, and FIG. 5B is an exploded side view showing the exploded state of the thruster 50 from the side. 6A is a top view of the thruster inner 53, and FIG. 6B is a cross-sectional view of the thruster inner 53 taken along the line VIb-VIb of FIG. 6A.

  As shown in FIGS. 5A and 5B, the thruster 50 is reciprocated in the longitudinal direction (vertical direction in FIG. 2) of the rod 40 by the driving force transmitted from the hydraulic actuator 21 (see FIG. 2). Is. The thruster 50 is made of a general structural rolled steel (SS400), and includes a thruster lower 51, a thruster upper 52, and a thruster inner 53.

  As shown in FIG. 5B, the thruster lower 51 includes an insertion pipe 54, a fastening plate 55, a base plate 56, and a thruster bearing 57. The insertion pipe 54 is configured as a cylindrical body having a square cross section, and a lower flange portion 54a projecting in a direction perpendicular to the axial direction of the insertion pipe 54 (the left-right direction in FIG. 5A) is formed at the upper end of the opening. I have.

  As shown in FIG. 5A, the base plate 56 is formed in a flat plate shape and includes a through-hole 56 a having the same shape as the cross-sectional shape of the insertion pipe 54, and the through-hole 56 a corresponds to the cross-sectional shape of the insertion pipe 54. Are welded to the lower end of the opening of the insertion pipe 54 (below in FIG. 5B).

  A plurality of fastening plates 55 (four in the first embodiment) are arranged on both sides of the insertion pipe 54 and are welded to the upper surface of the base plate 56 (the upper surface in FIG. 5B) and the outer surface of the insertion pipe 54. Yes. Therefore, the base plate 56 and the insertion pipe 54 can be firmly fixed.

  As shown in FIG. 5A, the thruster bearing 57 is a member for connecting the thruster 50 to the link 70 (see FIG. 2), and the thruster upper 52 in the top view (see FIG. 5A). Are arranged on both sides (FIG. 5A, left and right sides). Therefore, due to the reaction of the force acting on the link 70, a couple force acts on the thruster 50, so that the thruster 50 acts on a rotational force centered on the axial center of the thruster upper 52.

  As shown in FIG. 5B, the thruster bearing 57 has a pair of bearing plates 57a erected from the base plate 56 in the axial direction of the insertion pipe 54, and a shaft shape that is supported between the bearing plates 57a. The bearing shaft 57b is a shaft perpendicular to the axial direction (FIG. 5 (b) vertical direction) of the insertion pipe 54 (FIG. 5 (b) horizontal direction). The bearing shaft 57b has a through hole 57c that is formed through the insertion pipe 54 in the axial direction.

  Therefore, the second clevis shaft 75 (see FIG. 8A) provided in the second clevis portion 72 (see FIG. 8A) of the link 70 (see FIG. 8A) described later is inserted into the through hole 57c. Then, the link 70 can be rotated in two orthogonal directions around the thruster bearing 57. That is, the rotation about the bearing shaft 57b and the rotation about the through hole 57c can be performed simultaneously.

  Further, a bottom expansion blade bearing 67 (see FIG. 2A), which is a bearing equivalent to the thruster bearing 57, is attached to the inner surface of the bottom expansion blade 60 (see FIG. 2B). The mounting position of the bearing 67 is such that the axial center direction of the bottom expanded blade bearing shaft 67b (see FIG. 2B) having the same configuration as the bearing shaft 57b is the axial center direction of the insertion pipe 54 (vertical direction in FIG. 2B). The position is at a right angle.

  Therefore, when the bottom expanding blade 60 rotates with respect to the frame body 30, the shaft center of the bottom expanding blade bearing shaft 67 b rotates about the axis centering on the shaft center of the insertion pipe 54, and thus the shaft center of the bearing shaft 57 b. It becomes a twisted positional relationship. Therefore, in order to absorb the twist, the link 70 connected to the bottom blade bearing shaft 67b and the bearing shaft 57b has a bearing shaft on the side connected to the bottom blade bearing shaft 67b with the axis of the link 70 as the center. A mechanism that rotates with respect to the side connected to 57b is provided.

  As shown in FIG. 5B, the thruster upper 52 is a stopper for restricting the position of the thruster 50, and is configured as a cylindrical body having a square cross section, and has a lower end of the opening (lower end of FIG. 5B). Is provided with an upper flange portion 52a projecting in a direction perpendicular to the axial direction of the thruster upper 52 (the lower end in FIG. 5B).

  As shown in FIGS. 6 (a) and 6 (b), the thrust inner 53 is formed as a cylindrical body having a square cross section with a rolled steel material for general structure (SS400), and the upper end of the opening (FIG. 6 (a). ) At the upper end) is provided with an inner flange portion 53a projecting in a direction perpendicular to the axial center direction of the thruster inner 53 (the left-right direction in FIG. 6A).

  As shown in FIG. 6B, the inner flange portion 53a is formed in an annular shape having an outer shape of a square in a top view and an inner shape of a square in a top view, and the axial center direction of the thruster inner 53 (FIG. 6B). It has a plurality (eight in the first embodiment) of inner flange through-holes 53b that are through-molded in the direction perpendicular to the paper surface.

  Further, as shown in FIG. 5B, the outer shape of the thruster inner 53 corresponds to the inner shape of the insertion pipe 54. The outer dimension of the thruster inner 53 is smaller than the inner dimension of the insertion pipe 54 to such an extent that a gap can be fitted into the insertion pipe 54. Therefore, the thruster inner 53 is fitted in the insertion pipe 54, and the position is determined by contacting the lower flange portion 54a and the inner flange portion 53a.

  The lower flange portion 54a, the inner flange portion 53a, and the upper flange portion 52a are formed in a flat surface shape and have the same outer shape. A through hole is formed on the flat surface. When the lower flange portion 54a, the inner flange portion 53a, and the upper flange portion 52a are overlapped so as to coincide with each other, the respective through holes are arranged at corresponding positions. Therefore, the upper flange portion 52a is overlapped with the inner flange portion 53a overlapped with the lower flange portion 54a. Then, the bolts B are inserted into the through holes, the flange portions are fastened, and the thruster 50 is assembled. Thus, since the thruster inner 53 is configured to be detachable, only the thruster inner 53 can be replaced when worn.

  Next, the rod 40 will be described with reference to FIG. FIG. 7A is a side view showing the side surface of the rod 40, and FIG. 7B is a bottom view showing the bottom surface of the rod 40. In addition, the hatching shown to Fig.7 (a) has shown the site | part to which the flame quenching and tempering (JIS heat processing symbol: HQF * HT) process is performed.

  As shown in FIGS. 7A and 7B, the rod 40 has a cylindrical shape having an outer shape that is square when viewed from the bottom and an inner shape that is circular when viewed from the bottom. Therefore, the rod 40 can be made lighter than when the rod 40 is configured as a solid column.

  The rod 40 transmits the rotational force of the Keriba 15 (see FIG. 1) to the frame 30 and guides the thruster 50. The rod 40 is mainly composed of carbon steel for mechanical structure (S45C), An upper extension 44, a central heat treatment part 45, and a lower extension 46 are provided.

  The upper extension portion 44 is a portion on the upper end side of the rod 40, and the first first rod spacer 41a configured in an L shape from a rolled steel material for welding structure (SM490) is provided at the four corners of the upper end of the upper extension portion 44. Are arranged (eight in the first embodiment). A total of eight first rod spacers 41a are arranged at the four corners at the upper end of the upper extension 44 and four at the four corners below the upper end by a predetermined dimension (downward in FIG. 7A). . Further, a plurality of second rod spacers 41b formed in a flat plate shape from a rolled steel material for welded structure (SM490) are provided in the circumferential direction on the side surface of the rod 40 below the first rod spacer 41a by a predetermined dimension (first order). 4 in one embodiment).

  In the upper part of the upper extension 44 (the upper part in FIG. 7A), a rod through hole 42 is formed by penetrating in a direction perpendicular to the longitudinal direction of the rod 40 (FIG. 7A). After the rod 40 is fitted into the fitting hole, a kelly pin (not shown) is inserted into the rod through-hole 42 so that the rod 40 is locked to the lower end portion (the lower end portion in FIG. 1) of the kelly bar 15 (see FIG. 1). Is done.

  The central heat treatment part 45 is a part that extends from the lower end of the upper extension part 44 and slides with the inner peripheral surface of the thruster inner 53 of the thruster 50. Therefore, flame quenching / tempering (JIS heat treatment symbol: HQF / HT) treatment is performed on the outer peripheral surface of the central heat treatment portion 45. Therefore, since only the central heat treatment part 45 is subjected to flame quenching / tempering treatment, the rod 40 is manufactured in comparison with the case where the entire rod 40 is subjected to flame quenching / tempering treatment (JIS heat treatment symbol: HQF / HT). The cost can be suppressed and the product cost of the rod 40 can be reduced. As a result, the product cost of the bottom expansion bucket 19 can be reduced. The lower extension portion 46 is a portion extending below the central heat treatment portion 45.

  As described above, the inner peripheral surface of the thruster inner 53 is constituted by the general structural rolled steel (SS400). That is, since the thruster inner 53 is made of a material whose hardness is lower than that of the outer peripheral surface of the central heat treatment portion 45, the seizure between the central heat treatment portion 45 and the thruster inner 53 is suppressed, and the number of times the rod 40 is replaced. Can be reduced. Therefore, the maintenance cost of the bottomed bucket 19 can be reduced.

  Further, as described above, since the thruster inner 53 is configured to be detachable from the thruster lower 51, the thruster inner 53 that slides on the rod 40 is worn to prevent and wear the rod 40. Only the thruster inner 53 can be replaced.

  Therefore, compared with the case where both the rod 40 and the thruster lower 51 are replaced, the number of parts to be replaced can be reduced to one, so that the replacement part cost can be kept low. As a result, the maintenance cost of the bottom expansion bucket 19 can be reduced.

  Next, the link 70 will be described with reference to FIG. FIG. 8A is a partial side view showing a part of the link 70, and FIG. 8B is a partial sectional view of the link 70 taken along the line VIIIb-VIIIb of FIG. 8A. The arrows schematically show the grease flow. In addition, the hatching to the cross section of the seal ring R is abbreviate | omitted for simplification of drawing. FIG.8 (c) is a fragmentary sectional view of the link 70 in the VIIIc-VIIIc line | wire of Fig.8 (a). The link 70 is a member having a function of adjusting the positional relationship between the thruster 50 and the expanded wing 60 and a function of transmitting the reciprocating operation of the thruster 50 as the expanding / contracting operation of the expanded wing 60.

  As shown in FIG. 8A, the link 70 includes a main shaft portion 80 and a first clevis portion 71 screwed into one end (left end in FIG. 8A) of both ends of the main shaft portion 80. The second clevis part 72 screwed to the other end (the right end in FIG. 8A) opposite to the one end part to which the first clevis part 71 is screwed, the second clevis part 72 and the main shaft A pair of seal rings R (see FIG. 8B) configured in a ring shape by a rubber-like elastic body interposed between the portions 80 are provided. The main shaft portion 80 includes a first shaft portion 81, a second shaft portion 82, a right nut RN, and a left nut LN.

  As shown in FIG. 8C, the first shaft portion 81 is formed from a shaft base 83 configured in a columnar shape and one end face (left end face in FIG. 8C) of both end faces of the shaft base 83. The right male screw portion 84 that is convex and configured in a columnar shape, and the same axial center as the right male screw portion 84 that is provided so as to protrude from the other end surface (the right end surface in FIG. 8C) that is the surface opposite to the one end surface. And a left male thread portion 85 configured in a cylindrical shape.

  A right screw thread 84 a is formed on the outer peripheral surface of the right male screw portion 84, and a left screw thread 85 a is formed on the outer peripheral surface of the left male screw portion 85. The right thread 84a and the left thread 85a are configured as thread threads of a metric coarse thread having an outer diameter of 52 mm and a pitch of 5 mm. The right thread 84a is configured as a right thread, and the left thread 85a is configured as a left thread.

  As shown in FIG. 8A, FIG. 8B, and FIG. 8C, the second shaft portion 82 is formed in a columnar shape, and one end (FIG. 8A) of both ends of the columnar shape. ) A left female screw hole 86 that is recessed at the left end) and a trapezoidal male screw portion 87 that is convex and provided at the other end (the right end in FIG. 8 (a)) that is opposite to one end. Yes.

  As shown in FIG. 8C, the left female screw hole 86 is a bottomed hole, and a left screw thread 86a is formed on the inner peripheral surface of the left female screw hole 86 on the opening side. The left thread 86a is a left thread, and is configured as a metric coarse thread having a valley diameter of 52 mm and a pitch of 5 mm.

  Further, the left female screw hole 86 is screwed into the left male screw portion 85. Therefore, the first screwed into the first shaft portion 81 is adjusted by adjusting the screwing allowance between the left male screw portion 85 of the first shaft portion 81 and the left female screw hole 86 of the second shaft portion 82. The distance between the clevis portion 71 and the second clevis portion 72 screwed to the second shaft portion 82 is adjusted.

  As shown in FIG. 8B, the trapezoidal male screw portion 87 has a trapezoidal screw thread 87a formed on the outer peripheral surface. The trapezoidal thread 87a is a left-hand thread, and is configured as a trapezoidal thread having an outer diameter of 52 mm and a pitch of 8 mm.

  As shown in FIGS. 8A and 8C, the first clevis portion 71 includes a first clevis shaft 73 and a right female screw hole 74 that is recessed on the opposite side of the first clevis shaft 73. I have. The first clevis shaft 73 is formed in a columnar shape and has an axis in a direction perpendicular to the axis direction of the right male thread portion 84 (FIG. 8A, the direction perpendicular to the paper surface).

  Further, the first clevis shaft 73 is slidably fitted in a through-hole formed in the bottom expansion blade bearing shaft 67b (see FIG. 2) of the bottom expansion blade bearing 67 (see FIG. 2).

  As described above, the through-hole penetrates in the direction (FIG. 2 (b) vertical direction) perpendicular to the axial center direction (FIG. 2 (b) left-right direction) of the bottom expanded blade bearing shaft 67b. Therefore, the link 70 is centered on the first clevis shaft 73 as a center and the direction of rotation centered on the axis of the bottom expanding blade bearing shaft 67b and the direction orthogonal to the axis of the bottom expanding blade bearing shaft 67b. It can be rotated in two directions with the rotation direction.

  As shown in FIG. 8C, the right female screw hole 74 is a bottomed hole, and a right screw thread 74 a is formed on the inner peripheral surface on the opening side of the right female screw hole 74. The right thread 74a is a right thread, and is configured as a thread of a metric coarse thread having a valley diameter of 52 mm and a pitch of 5 mm.

  Further, the right female screw hole 74 is screwed into the right male screw portion 84. Therefore, the first clevis portion 71 and the first shaft portion 81 are adjusted by adjusting the screwing allowance between the right male screw portion 84 of the first shaft portion 81 and the right female screw hole 74 of the first clevis portion 71. The distance from the second clevis portion 72 screwed through the second shaft portion 82 is adjusted.

  As shown in FIGS. 8A and 8B, the second clevis portion 72 includes a second clevis shaft 75, a trapezoidal female screw hole 76 that is recessed on the opposite side of the second clevis shaft 75, and A grease nipple 77 that injects grease into the trapezoidal female screw hole 76 and a discharge hole 78 that is configured as a through-hole and discharges the grease from the trapezoidal female screw hole 76 are provided. The grease nipple 77 includes an injection hole 77 a formed as a through hole that communicates the inside and the outside of the trapezoidal female screw hole 76.

  The second clevis shaft 75 is formed in a cylindrical shape and has a shaft center in a direction perpendicular to the axial direction of the right male threaded portion 84 (FIG. 8 (a) perpendicular to the paper surface), and the bearing shaft 57b of the thruster bearing 57. And is slidably fitted in a through hole 57c (see FIG. 5B) formed through.

  As described above, the through-hole 57c penetrates in the direction (FIG. 5 (b) vertical direction) orthogonal to the axial direction (FIG. 5 (b) left-right direction) of the bearing shaft 57b. Therefore, the link 70 is centered on the second clevis shaft 75 and pivoted about the axis of the bearing shaft 57b, and pivoted about the direction orthogonal to the axis of the bearing shaft 57b. (See FIG. 5B).

  As shown in FIG. 8B, the trapezoidal female screw hole 76 is a hole with a bottom, and a pair of seal ring grooves 79 are recessed in the inner peripheral surface on the opening side of the trapezoidal female screw hole 76. A trapezoidal thread 76a is formed on the bottom side (the right side in FIG. 8B) of the seal ring groove 79. A grease storage chamber 76b, which is a space on the bottom side of the trapezoidal female screw hole 76, is coupled to the bottom side of the trapezoidal screw thread 76a. The trapezoidal thread 76a is a left-hand thread and is configured as a trapezoidal thread with a valley diameter of 52 mm and a pitch of 8 mm. The trapezoidal female thread hole 76 is screwed into the trapezoidal male thread portion 87. ing.

  For example, when the positions of the discharge hole 78 and the grease nipple 77 are switched, the grease pressure-fed from the grease nipple 77 is pressure-fed toward both the trapezoidal screw thread 87a of the trapezoidal male screw portion 87 and the seal ring R. The In this case, in order to make the grease reach the trapezoidal screw thread 87a of the trapezoidal male thread portion 87, it is necessary to pump the grease with a high pressure. However, when the grease is pumped at a high pressure, the grease pumped from the seal ring R leaks, and there is a problem that the grease is difficult to reach the trapezoidal screw thread 87a of the trapezoidal male screw portion 87.

  On the other hand, according to the first embodiment, the grease pumped from the grease nipple 77 is stored in the grease storage chamber 76b and is pumped only to the trapezoidal screw thread 87a of the trapezoidal male screw portion 87. Therefore, it is possible to set a high pressure for feeding the grease, and the grease passes through the gap between the trapezoidal screw thread 87a of the trapezoidal male screw portion 87 and the trapezoidal screw thread 76a of the trapezoidal female screw hole 76, thereby forming a trapezoidal female screw hole 76. To the opening side (left side in FIG. 8B). Therefore, grease is attached to the trapezoidal thread thread 87a of the trapezoidal male thread portion 87. Since the grease pushed out from the gap between the trapezoidal screw thread 76a and the trapezoidal screw thread 87a is sealed by the seal ring R, it does not flow out from the opening side of the trapezoidal female screw hole 76 but is discharged from the discharge hole 78.

  As a result, the trapezoidal thread 87a of the trapezoidal male thread 87 can be sufficiently lubricated, so that the trapezoidal thread 87a of the trapezoidal male thread 87 and the trapezoidal thread 76a of the trapezoidal female thread hole 76 are suppressed. Thus, the durability of the link 70 can be improved.

  The pressure-fed grease reaches the discharge hole 78 through a gap between the trapezoidal screw thread 87a of the trapezoidal male screw portion 87 and the trapezoidal screw thread 76a of the trapezoidal female screw hole 76. Further, the pressure applied to the grease reaching the discharge hole 78 passes through the gap due to pressure loss due to the gap between the trapezoidal thread 87a of the trapezoidal male thread 87 and the trapezoidal thread 76a of the trapezoidal female screw hole 76. The pressure is sufficiently lower than the previous pressure on the grease nipple 77 side. Therefore, the seal ring R prevents the grease from leaking and the grease is discharged only from the discharge hole 78. Therefore, leakage of grease from the seal ring R when the grease is pumped from the injection hole can be prevented.

  As shown in FIG.8 (c), the right nut RN and the left nut LN are comprised by the cylindrical shape, and a pair of parallel surfaces are formed in the cylindrical outer peripheral surface. A right thread RNa is formed on the inner peripheral surface of the right nut RN, and a left thread LNa is formed on the inner peripheral surface of the left nut LN. These right thread RNa and left thread LNa are configured as thread threads of a metric coarse thread having a valley diameter of 52 mm and a pitch of 5 mm. The right thread RNa is configured as a right thread thread, and the left thread LNa is configured as a left thread thread. The right nut RN and the left nut LN are screwed into the right male screw portion 84 and the left male screw portion 85.

  Therefore, in a state where the first clevis portion 71 is screwed to the right male screw portion 84, the right nut RN screwed to the right male screw portion 84 is placed on the first clevis portion 71 side (left side in FIG. 8C). In the state where the second shaft portion 82 is screwed to the left male screw portion 85, the left nut LN screwed to the left male screw portion 85 is moved to the second shaft portion 82 side (right side in FIG. 8C). When tightened, the first shaft portion 81 is fixed so as not to rotate with respect to the first clevis portion 71 and the second shaft portion 82, and the entire length of the link 70 is fixed to the adjusted length.

  As a result, the diameter-expanded dimension of the bottom-expanded blade 60 whose diameter is expanded by the lowering of the thruster 50 (the maximum diameter of the bottom-expanded blade 60) is the position of the thruster 50 (see FIG. 2B) in the vertical direction (FIG. 2B). It is possible to accurately correspond to the dimension between the outer end portions.

  Further, when the bottom expanding blade 60 rotates with respect to the frame body 30, the positional relationship between the bottom expanding blade bearing 67 of the bottom expanding blade 60 and the thruster bearing 57 of the thruster 50 becomes a twisted positional relationship (see FIG. 2). Therefore, since the trapezoidal female screw hole 76 and the trapezoidal male screw portion 87 are screwed together without being fixed in the rotation direction, the rotation of the trapezoidal female screw hole 76 and the trapezoidal male screw portion 87 is utilized. The first clevis portion 71 and the second clevis portion 72 are rotated about the axis of the right male threaded portion 84 to absorb the twist.

  For example, when the overall length of the link 70 is adjusted to be long, the trapezoidal female screw hole 76 and the trapezoidal male screw portion 87 are adjusted by rotating the trapezoidal female screw hole 76 and the trapezoidal male screw portion 87 to adjust the overall length of the link 70. There is a problem in that it is difficult to secure the strength of the link 70 because the screwing length is shortened.

  In order to secure the screwing length, at least one of the first clevis portion 71 or the second clevis portion 72 is removed from the expanded wing 60, and the first clevis portion 71 and the right male screw portion 84 are connected to the entire length of the link 70. Is relatively rotated in the rotational direction in which the length of the link 70 is increased, and the trapezoidal female screw hole 76 and the trapezoidal male screw portion 87 are relatively rotated in the rotational direction in which the overall length of the link 70 is shortened (screwing length is increased). Therefore, there is a problem that it takes time to adjust the overall length of the link 70.

  Here, in the first embodiment, since the trapezoidal female screw hole 76 and the trapezoidal male screw portion 87 are provided, the first clevis portion 71 and the right male screw portion 84 are screwed together, and the second shaft portion 82. The total length of the link can be adjusted by screwing with the left male thread portion 85. Therefore, it is possible to prevent the screwing length between the trapezoidal female screw hole 76 and the trapezoidal male screw portion 87 from being changed along with the adjustment of the overall length of the link. For this reason, the screwing length can be set to an optimum length in terms of the strength of the link 70, the adjustment of the overall length of the link 70 can be facilitated, and the strength of the link 70 can be ensured.

  Further, the right male screw portion 84 and the right female screw hole 74, and the left male screw portion 85 and the left female screw hole 86 are portions for adjusting the overall length of the link 70, so that the overall length of the link 70 is finely adjusted. Therefore, the amount of screwing per rotation of the right male screw portion 84 and the left male screw portion 85 is made smaller than the screwing amount of the trapezoidal male screw portion 87.

  That is, the pitches of the right thread 84a of the right male thread portion 84 and the right thread 74a of the right female thread hole 74 are determined by the pitch of the trapezoidal thread 87a of the trapezoidal male thread 87 and the trapezoidal thread 76a of the trapezoidal female thread hole 76. Since it is made smaller, there is a problem that the right screw thread 84a of the right male screw portion 84 and the right screw thread 74a of the right female screw hole 74 are damaged by the compressive force and tensile force caused by the reciprocating movement of the thruster 50.

  As described above, in the conventional product, as a method of fixing the entire length of the link 70, a method of fixing the rotation of the right male screw portion 84 and the right female screw hole 74 with a key is taken. There was a gap (play) between the right screw thread 84 a and the right screw thread 74 a of the right female screw hole 74. As a result, the compressive force / tensile force caused by the reciprocating movement of the thruster 50 causes the right screw thread 84a of the right male screw portion 84 and the right screw thread 74a of the right female screw hole 74 to collide with each other. is there.

  The same problem occurs with respect to the left thread 85a of the left male thread portion 85 and the left thread 86a of the left female thread hole 86.

  On the other hand, according to the first embodiment, the right male threaded portion 84 is tightened by the right female threaded hole 74 and the right nut RN. Play with the right thread 74a can be eliminated. That is, by eliminating play, the right screw thread 84a of the right male screw portion 84 and the right screw thread 74a of the right female screw hole 74 are brought into close contact with each other, and the right screw thread 84a and the right female screw hole 74 of the right male screw portion 84 are brought into close contact with each other. Can be prevented from colliding with the right screw thread 74a, and the generation of impact force can be suppressed. As a result, it is possible to improve the durability of the link 70 by suppressing damage to the right thread 84a of the right male thread portion 84 and the right thread 74a of the right female thread hole 74.

  Similarly, since the left male thread portion 85 is tightened by the left female thread hole 86 and the left nut LN, damage to the left thread 85a of the left female thread 85 and the left thread 86a of the left female thread hole 86 is suppressed. The durability of the link 70 can be improved.

  On the other hand, the trapezoidal male screw portion 87 and the trapezoidal female screw hole 76 are portions for absorbing the twist of the link 70 accompanying the rotation of the bottom expanded wing 60. When the screw portion 87 is tightened with the trapezoidal female screw hole 76 and the nut, the trapezoidal male screw portion 87 cannot rotate with respect to the trapezoidal female screw hole 76 and the twist of the link 70 cannot be absorbed. Therefore, it is necessary to improve the strength of the trapezoidal screw thread 87a of the trapezoidal male screw part 87 and the trapezoidal screw thread 76a of the trapezoidal female screw hole 76 in a state where the trapezoidal male screw part 87 is rotatable with respect to the trapezoidal female screw hole 76. is there.

  On the other hand, according to the first embodiment, the trapezoidal screw thread 87a of the trapezoidal male screw portion 87 and the trapezoidal screw thread 76a of the trapezoidal female screw hole 76 are configured as screw threads of a trapezoidal screw. As compared with the case where the trapezoidal male thread portion 87 is used, the strength of the trapezoidal screw thread 87a of the trapezoidal male thread portion 87 and the trapezoidal thread thread 76a of the trapezoidal female screw hole 76 can be improved. Therefore, damage to the trapezoidal thread 87a of the trapezoidal male thread portion 87 and the trapezoidal thread 76a of the trapezoidal female screw hole 76 can be suppressed, and the durability of the link can be improved.

  For example, the right screw thread 84a of the right male screw portion 84 and the left screw thread 85a of the left male screw portion 85 are a screw (right screw and right screw, or left screw and left screw) having a spiral winding in the same direction. In this case, the first clevis portion 71 and the second clevis portion 72 are fixed to the bottom expanded blade 60 and the thruster 50, and the first shaft portion 81 is centered on the axis of the first shaft portion 81. When rotating clockwise toward the portion 71, the first clevis portion 71 and the second clevis portion 72 move in the same direction with respect to the first shaft portion 81. That is, since the first clevis part 71 and the second clevis part 72 are screwed to both ends of the first shaft part 81, the second clevis part 72 is separated from the first shaft part 81 and the first clevis part 71 approaches the main shaft portion 80.

  Therefore, when the pitches of the right screw thread 84a of the right male screw part 84 and the left screw thread 85a of the left male screw part 85 are the same, the first shaft part 81 of the first clevis part 71 and the second clevis part 72 is used. Therefore, the positional relationship between the first clevis portion 71 and the second clevis portion 72 does not change. That is, the total length of the link 70 is not adjusted.

  In this case, the link 70 is removed from at least the bottom widened blade 60 or the thruster 50, and the first clevis portion 71 and the second clevis portion 72 are rotated in different directions with respect to the first shaft portion 81, respectively. Can be adjusted.

  However, it is necessary to remove the first clevis portion 71 and the second clevis portion 72 from the expanded bottom blade 60 or the thruster 50, and to assemble the link 70 on the expanded bottom blade 60 or the thruster 50 after adjusting the overall length of the link 70 alone. Therefore, there is a problem that the work cost increases.

  Further, since the total length of the adjusted link 70 is not a length that takes into account the displacement of the position of the assembly portion, the accuracy of positioning of the bottom expansion blade 60 is higher than when the link 70 is not removed. There is a problem of being inferior.

  On the other hand, when the pitches of the right thread 84a of the right male thread 84 and the left thread 85a of the left male thread 85 are different, the first clevis part 71 and the second clevis part 72 have a first pitch as described above. Although the movement direction with respect to the 1 shaft part 81 is the same direction, the movement amount with respect to the 1st shaft part 81 of the 1st clevis part 71 and the 2nd clevis part 72 differs. That is, since the movement amount of the other of the first clevis portion 71 and the second clevis portion 72 is larger than the movement amount of one of the first clevis portion 71 and the second clevis portion 72, the difference between the movement amounts is the first clevis portion 71 and the second clevis portion 72. The total length of the link 70 can be adjusted.

  However, when the total length of the link 70 is to be adjusted within the range of the predetermined adjustment allowance, the length of the screw portion screwed into the first clevis portion 71 and the second clevis portion 72 is greater than the predetermined adjustment allowance. Since it does not have to be lengthened, there is a problem in that unnecessary machining occurs and manufacturing efficiency deteriorates as the thread portion is lengthened.

  On the other hand, according to the first embodiment, the right thread 84a of the right male thread portion 84 is configured as a right thread, and the left thread 85a of the left male thread portion 85 is configured as a left thread. Even when the link 70 is connected to the bottom expanded blade 60 and the thruster 50, when the first shaft portion 81 is rotated clockwise or counterclockwise with respect to the first clevis portion 71, the first clevis portion 71 and the second clevis portion 72. Can be close or separated.

  Therefore, the operation cost for adjusting the position of the bottom expansion blade 60 can be reduced by omitting the operation of attaching / detaching the link 70 to / from the bottom expansion blade 60 or the thruster 50. Further, since the total length of the link 70 can be adjusted while the link 70 is attached to the bottom expanding blade 60 or the thruster 50, the alignment accuracy of the bottom expanding blade 60 can be improved and the total length adjustment of the link 70 is efficient. Can be done automatically.

  Further, since the right thread 84a of the right male thread portion 84 and the left thread 85a of the left male thread portion 85 can all be used for adjustment of the total length of the link 70, the above-described spiral windings having the same direction are provided. Compared with screws (right and right threads, or left and left threads), the right thread 84a of the right male thread 84 and the left thread 85a of the left male thread 85 can be shortened even with the same adjustment allowance. it can. Therefore, unnecessary processing can be omitted and manufacturing efficiency can be improved.

  In addition, the left thread 86a of the left female thread hole 86 screwed into the left thread 85a of the left male thread 85 is configured in a shape corresponding to the left male thread 85 left thread 85a. The right screw thread 74a of the right female screw hole 74 screwed into the right screw thread 84a of the right male screw part 84 is also configured in a shape corresponding to the right screw thread 84a of the right male screw part 84.

  Next, a second embodiment will be described with reference to FIG. FIG. 9 is a partial cross-sectional view showing a part of the cross section of the bottom expanded wing 60 and the frame body 30 in the second embodiment, and FIG. 9A is a cross-sectional view of FIG. FIG. 9B corresponds to a partial cross-sectional view showing a part of the cross section of the bottom expanded wing 60 and the frame body 30 along line IVa, and FIG. 9B illustrates the bottom expanded wing 60 along line IVb-IVb in FIG. This corresponds to a partial cross-sectional view showing a part of the cross section between the frame body 30 and the frame 30. In FIGS. 9A and 9B, the positions of the welded portions on the outer periphery of the frame body collar 235 and the bottom wing collar 265 are represented by a group of straight lines indicating the outer periphery of the frame body collar 235 and the bottom wing collar 265. Show.

  In the first embodiment (see FIG. 4), the frame collar 35 and the bottom wing collar 65 are configured to include the frame collar hole 35a and the bottom wing collar hole 65a, which are through holes, but in the second embodiment, The bottom wing collar 265 and the frame collar 235 are configured to include a communication portion K for removing the bottom wing collar 265 and the frame collar 235 from the shaft F. In addition, the same code | symbol is attached | subjected to the part same as said each embodiment, and the description is abbreviate | omitted.

  For example, in the first embodiment, the bottom wing collar 65 and the frame collar 35 have a bottom wing collar hole 65a that is a through hole and a frame collar hole 35a that is a through hole. 65a and the frame collar hole 35a are externally fitted to the shaft F. Therefore, when replacing the bottom wing collar 65 and the frame collar 35, the shaft F needs to be extracted from the bottom wing pipe 63 and the frame pipe 33. there were.

  On the other hand, according to the second embodiment, the bottom wing collar 265 and the frame collar 235 include the outer edge of the bottom wing collar 265 and the outer edge of the frame collar 235, the bottom wing collar hole 265a, and the frame body collar hole 235a. And the opening dimension T of the communication part K is configured to be equal to or larger than the diameter dimension D of the shaft F.

  For this reason, the bottom expansion blade collar 265 and the frame collar 235 can be removed from or attached to the shaft F by using the communicating portion K of the bottom expansion blade collar 265 and the frame body collar 235. As a result, the bottom wing collar 265 and the frame collar 235 can be removed from the shaft F and replaced without removing the shaft F from the bottom wing pipe 63 and the frame pipe 33. As a result, the trouble of removing the shaft F from the bottom expanding blade 60 and the frame 30 can be saved, and the maintenance cost of the bottom expanding bucket 19 can be reduced.

  As shown in FIGS. 9A and 9B, the welded portion 2W1 of the bottom wing collar 265 and the frame collar 235 has a circumferential direction centering on the axis of the bottom wing pipe 63 and the frame pipe 33. In addition, the welding is performed in the range of 45 degrees along the outer peripheries of the bottom widened blade collar 265 and the frame body collar 235 and is located only at one position on the opposite side of the communication portion K.

  The welded portion 2W2 of the bottom wing collar 265 and the frame body collar 235 is arranged on the outer circumference of the bottom wing collar 265 and the frame body collar 235 in the circumferential direction around the axis of the bottom wing pipe 63 and the frame body pipe 33. It is welding of the range of 30 degrees along, and is located in two places shifted from the place on the opposite side of the communication part K by 90 degrees in both directions along the outer periphery of the bottom wing collar 265 and the frame collar 235.

  For example, if the position of the bottom wing collar 265 and the frame collar 235 close to the communication portion K is a welded portion, the bottom wing collar 265 and the frame collar 235 provided with the communication portion K are C-shaped, and thus from the welded portion. The part to the communication part K is divided into a short part and a long part. For this reason, the short part has a faster temperature rise due to the heat of welding than the long part, and there is a risk of annealing and deformation, so the welding range cannot be widened.

  On the other hand, according to the second embodiment, the welded portion 2W1 that is the opposite side of the communicating portion K is welded in a range of 45 degrees, and the welded portion 2W2 that is closer to the communicating portion K than the welded portion 2W1 is 30 degrees. Therefore, it is possible to prevent a partial increase in temperature due to the heat of welding of the bottom wing collar 265 and the frame collar 235, and to prevent annealing and deformation of the bottom wing collar 265 and the frame collar 235. Can do.

  Further, the communication portion K of the frame body collar 235 is formed on the outer surface side (lower side in FIG. 9A) of the frame body 30 of the shaft F. Therefore, the bottom expansion blade collar 265 is located inside the bottom expansion blade 60. Can be removed. Further, since the communicating portion K of the bottom wing collar 265 is formed on the outer surface side (lower side in FIG. 9B) of the bottom wing 60 of the shaft F, the bottom wing collar 265 is located inside the bottom wing 60. Can be removed.

  Next, a third embodiment will be described with reference to FIG. FIG. 10 is a partial cross-sectional view showing a part of the cross section of the bottom expanded wing 60 and the frame body 30 in the third embodiment. FIG. 10 (a) is a view of FIG. FIG. 10B corresponds to a partial cross-sectional view showing a part of the cross section between the expanded wing 60 and the frame 30 taken along the line IVa. FIG. 10B shows the expanded wing 60 taken along the line IVb-IVb in FIG. This corresponds to a partial cross-sectional view showing a part of the cross section between the frame body 30 and the frame 30. In FIGS. 10A and 10B, the positions of the welded portions on the outer periphery of the frame body collar 335 and the bottom wing collar 365 are represented by a group of straight lines on the outer periphery of the frame body collar 335 and the bottom wing collar 365. Show.

  In the first embodiment (see FIG. 4), the frame collar 35 and the bottom wing collar 65 are provided with the frame collar hole 35a that is a through hole and the bottom wing collar hole 65a that is a through hole. In the third embodiment, the bottom wing collar 365 and the frame collar 335 are configured in a pair of half-moon shapes. In addition, the same code | symbol is attached | subjected to the part same as said each embodiment, and the description is abbreviate | omitted.

  For example, as described above, in the first embodiment, the shaft F needs to be extracted in order to replace the bottom wing collar 65 and the frame collar 35.

  On the other hand, according to the third embodiment, since the bottom wing collar 365 formed in a half moon shape and the frame body color 335 formed in a half moon shape are provided, the bottom wing collar 265 and the frame body color 235 are provided. It can be removed from or attached to the shaft F. Therefore, the bottom expansion blade collar 365 and the frame collar 335 can be detached from the shaft F and replaced without removing the shaft F from the bottom expansion blade pipe 63 and the frame body pipe 33. As a result, the trouble of removing the shaft F from the bottom expanding blade 60 and the frame 30 can be saved, and the maintenance cost of the bottom expanding bucket 19 can be reduced.

  The welded portion 3W1 of the bottom wing collar 365 and the frame collar 335 is welded in the range of 45 degrees along the outer periphery of the bottom wing collar 365 and the frame collar 335, and the divided bottom wing collar 365 and frame body are divided. The collar 335 is located only at one central portion in the circumferential direction.

  The welded portion 3W2 of the bottom wing collar 365 and the frame body color 335 is welded in a range of 30 degrees along the outer periphery of the bottom wing collar 365 and the frame body color 335. It is located at two positions shifted from the center in the circumferential direction by 60 degrees in both directions along the outer peripheries of the bottom wing collar 365 and the frame collar 335.

  For example, if a portion near the ends of the bottom wing collar 365 and the frame collar 335 is a welded portion, the bottom wing collar 365 and the frame collar 335 are half-moon shaped and thus have a short and long portion from the welded portion. Divided into parts. Therefore, the short part has a higher temperature rise due to welding heat than the long part, and there is a risk of annealing or deformation. Therefore, it is not possible to widen the welding range of short parts.

  On the other hand, according to the third embodiment, the welded portion 3W1 in the center in the circumferential direction of the bottom expanding blade collar 365 and the frame collar 335 is welded in a range of 45 degrees, and the welded portion 3W1 has a bottom expanding blade collar. 365 and the welded portion 3W2 close to the end of the frame collar 335 are welded in a range of 30 degrees, so that a partial temperature rise due to the heat of welding is prevented, and the bottom wing collar 365 and the frame collar 335 are annealed. In addition, deformation can be prevented.

  The frame collar 335 is disposed on the outer surface side (the lower side in FIG. 9A) and the inner side surface (the upper side in FIG. 9A) of the frame body 30 of the shaft F, so The collar 365 can be removed on the inside and outside of the bottom wing 60. Further, since the bottom wing collar 365 is disposed on the outer surface side (the lower side in FIG. 9B) and the inner side surface (the upper side in FIG. 9B) of the bottom wing 60 of the shaft F, the bottom wing blade is provided. The collar 365 can be removed on the inside and outside of the bottom wing 60.

  Next, a fourth embodiment will be described with reference to FIG. FIG. 11A is a partial side view showing a part of the link 470. FIG. 11B corresponds to FIG. 8A, and FIG. 11B shows the link 470 taken along the line XIb-XIb in FIG. FIG. 8 is a partial cross-sectional view corresponding to FIG. Moreover, FIG.11 (c) is a fragmentary sectional view of the link 470 in the XIc-XIc line | wire of Fig.11 (a), and respond | corresponds to FIG.8 (c).

  In the first embodiment (see FIG. 8), the first shaft portion 81 is provided with a left male screw portion 85 at one end, and the left male screw portion 85 is connected to the left female screw hole 86 of the second shaft portion 82 and the left nut LN. However, in the fourth embodiment, the first shaft portion 81 and the second shaft portion 82 are integrally formed. In addition, the same code | symbol is attached | subjected to the part same as said each embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 11A, the link 470 mainly includes a main shaft portion 480 and a first clevis screwed to one end (left end in FIG. 11A) of both ends of the main shaft portion 480. Part 71 and a second clevis part 72 screwed to the other end (the right end in FIG. 8A) opposite to the one end part to which the first clevis part 71 is screwed. The part 480 includes a right nut RN.

  As shown in FIG. 11 (a), the main shaft portion 480 is a right male screw projecting from one end surface (the left end surface in FIG. 8 (a)) of both end surfaces of the main shaft portion 480 and configured in a cylindrical shape. And a trapezoidal male screw having the same axis as the right male screw portion 484 and projecting from the other end surface (the right end surface in FIG. 8A) that is the surface opposite to the one end surface Part 487.

  A right thread 484 a is formed on the outer peripheral surface of the right male thread portion 484. The right thread 484a is a thread of a right thread, and is configured as a thread of a metric coarse thread having an outer diameter of 52 mm and a pitch of 5 mm. The right male screw portion 484 is screwed into the right female screw hole 74.

  As shown in FIG. 11 (b), the trapezoidal male thread portion 487 has a trapezoidal thread 487a formed on the outer peripheral surface. The trapezoidal thread 487a is a left-hand thread and is configured as a trapezoidal thread having an outer diameter of 52 mm and a pitch of 8 mm. The trapezoidal male screw portion 487 is screwed into the trapezoidal female screw hole 76.

  For example, in the first embodiment, a left male screw portion 85 is provided at one end of the first shaft portion 81, and the left female screw hole 86 of the second shaft portion 82 and the left nut LN are screwed into the left male screw portion 85. Therefore, it takes time and labor to process the left male screw portion 85 and the left female screw hole 86 and to manufacture the left nut LN.

  On the other hand, according to the fourth embodiment, the left male screw portion 85 and the left female screw hole 86 which are screwed portions of the first shaft portion 81 and the second shaft portion 82 are omitted, and the first shaft portion 81 is omitted. And the second shaft portion 82 are integrated to form a main shaft portion 480.

  Therefore, the labor for processing the left male screw portion 85 and the left female screw hole 86 and the labor for manufacturing the left nut LN can be saved, and the manufacturing cost of the link 70 can be reduced. Therefore, the product cost of the bottomed bucket 19 can be reduced.

  For example, when the right screw thread 484a of the right male screw portion 484 and the trapezoid screw screw thread 487a of the trapezoid male screw portion 487 are the same pitch right screw and right screw, or the same pitch left screw and left screw combination. When the right male screw portion 484 and the trapezoidal male screw portion 487 are rotated with respect to the first clevis portion 71 and the second clevis portion 72, the amount of screwing and the direction of the right male screw portion 484 and the trapezoidal male screw portion 487 are changed. Since it becomes the same, the full length of the link 470 is not adjusted.

  In this case, the link 470 is removed from at least the bottom wing 60 or the thruster 50, and the first clevis part 71 and the second clevis part 72 are rotated in different directions with respect to the right male screw part 484 and the trapezoidal male screw part 487, respectively. Thus, the overall length of the link 470 can be adjusted. However, since the operation | work which removes the link 470 and the operation | work which assembles the link 470 again are needed, there exists a malfunction that work cost increases. In addition, since the total length of the adjusted link 470 is not a length that takes into account the displacement of the position of the assembly portion, the accuracy of alignment of the bottom wing 60 is higher than when the link 470 is not removed. There is a problem of being inferior.

  On the other hand, in the fourth embodiment, the right male screw portion 484 includes the right screw thread 84a, and the trapezoidal male screw portion 487 includes the trapezoidal screw thread 87a. Therefore, the main shaft portion 480 is connected to the first clevis portion 71. , The positional relationship between the first clevis part 71 and the second clevis part 72 changes, and the overall length of the link 470 is adjusted. Thereafter, the right nut RN screwed to the right male screw portion 484 is screwed to the first clevis portion 71 side (left side in FIG. 11 (c)), and the right male screw portion 484 is fixed to the main shaft portion 480. To do.

  Since the first clevis part 71 and the second clevis part 72 screwed to both ends of the main shaft part 480 are pivotally supported by the frame body 30 and the bottom expanded blade 60, the main shaft part 480 is connected to the first clevis part 71. If it fixes only with respect to, since it can prevent that the main shaft part 480 rotates and pulls out, the screwing of the 2nd clevis part 72 and the main shaft part 480 can be made rotatable.

  Therefore, it is possible to reduce the manufacturing cost of the link 70 by eliminating the trouble of processing the left male screw portion 85 and the left female screw hole 86 and the trouble of manufacturing the left nut LN after solving the above-described problems. it can. Therefore, the product cost of the bottomed bucket 19 can be reduced.

  In the fourth embodiment, the total length is adjusted by a combination of a right screw having a pitch of 5 mm and a left screw having a pitch of 8 mm. In the first embodiment, a combination of a right screw having a pitch of 5 mm and a left screw having a pitch of 5 mm is adjusted. Adjust the length with. Therefore, from the viewpoint of finely adjusting the overall length of the link 70, the first embodiment that can finely adjust the overall length of the link 70 is more preferable than the fourth embodiment.

  The present invention has been described above based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. Can be easily guessed.

  For example, the numerical values (for example, the number, size, angle, etc. of each component) given in the above embodiments are merely examples, and other numerical values can naturally be adopted.

  In each of the above embodiments, the case where the thruster inner 53 is configured as one member has been described. However, the present invention is not necessarily limited to this, and the thruster inner 53 is divided into two along the axial direction. Also good.

  In this case, after the thruster 50 is lowered while the thruster 50 is fitted to the rod 40, the thruster upper 52 and the thruster lower 51 are disassembled to raise the thruster upper 52, and the space formed by raising the thruster upper 52. Is used to pull out the thruster inner from the thruster lower 51.

  Then, the thrust inner can be removed from the rod 40 by dividing the thrust inner into left and right. Therefore, since the thruster inner 53 can be replaced without removing the rod 40, the labor for replacing the thruster inner can be saved and the maintenance cost of the bottomed bucket 19 can be reduced.

  Further, in each of the above-described embodiments, the thruster inner 53 is connected to the thruster lower 51, the thruster upper 52, and the inner flange 53a that is in contact with the lower flange 54a by further abutting the upper flange 52a with a bolt. However, the present invention is not limited to this. The inner flange portion 53a of the thruster inner 53 is directed downward, and the thruster inner 53 is moved from the through hole 56a side of the base plate 56 to the thruster lower. The inner flange 53a may be inserted and fastened to the base plate 56 with a bolt.

  In this case, it is not necessary to divide the thruster 50 into the thruster upper 52 and the thruster lower 51. Therefore, since the number of parts constituting the bottom expansion bucket 19 can be reduced, the product cost of the bottom expansion bucket 19 can be reduced.

  Further, in each of the above embodiments, the case where the thruster lower 51 is configured by the general structural rolled steel (SS400) has been described. However, the present invention is not necessarily limited thereto, and the welded structural rolled steel (SM490) or the machine You may comprise by structural carbon steel materials (S45C).

  In this case, it is possible to improve the hardness of the thruster lower 51 and suppress the deformation of the thruster lower 51 as compared with the case where the thruster lower 51 is made of the general structural rolled steel (SS400). Therefore, the amount of movement of the hydraulic actuator 21 can be accurately transmitted to the expanded bottom blade 60, and the diameter expansion accuracy of the expanded bottom blade 60 can be improved.

  In each of the above-described embodiments, the case where the rod 40 is configured in a cylindrical shape has been described. However, the configuration is not necessarily limited thereto, and the rod 40 may be configured in a solid column shape.

  In this case, the processing of the rod 40 can be omitted as compared with the case where the rod 40 is formed in a cylindrical shape. Therefore, the product cost of the bottom expansion bucket 19 can be reduced by reducing the processing cost of the rod 40.

  In each of the above embodiments, the case where the threads of the right male screw portion 84, the right female screw hole 74, the left male screw portion 85, and the left female screw hole 86 are configured as coarse threads has been described. It is not restricted to this, You may comprise with a fine screw.

  In this case, the amount of screwing per rotation of the shaft base 83 can be reduced as compared with the case where the screw is constituted by coarse screws. Therefore, the diameter expansion position of the bottom expansion blade 60 with respect to the hydraulic actuator 21 can be adjusted with high accuracy.

  In each of the above-described embodiments, the case where the right male screw portion 84 is configured as a male screw and the right female screw hole 74 is configured as a female screw has been described. However, the present invention is not necessarily limited thereto, and the right male screw portion 84 is not necessarily limited thereto. The female screw may be configured as a female screw, and the right female screw hole 74 may be configured as a male screw.

  Further, in each of the above embodiments, the case where the left male screw portion 85 is configured as a male screw and the left female screw hole 86 is configured as a female screw has been described. The portion 85 may be configured as a female screw, and the left female screw hole 86 may be configured as a male screw.

  In each of the above embodiments, the case where the trapezoidal male screw portion 87 is configured as a male screw and the trapezoidal female screw hole 76 is configured as a female screw has been described. The portion 87 may be configured as a female screw, and the trapezoidal female screw hole 76 may be configured as a male screw.

  Further, in the first embodiment, the second embodiment, and the third embodiment, the case where the trapezoidal screw thread 76a and the trapezoidal screw thread 87a are configured as left-hand screw threads has been described. The trapezoidal thread 76a and the trapezoidal thread 87a may be configured as a right-hand thread.

  In each of the above embodiments, the right thread 74a, the right thread 84a, and the right thread RNa are configured as right thread threads, and a trapezoidal thread 76a, a trapezoidal thread 87a, a left thread 86a, and a left thread. Although the case where the thread 85a and the left-hand thread LNa are configured as the thread of the left-hand thread has been described, the present invention is not necessarily limited to this, and the right-hand thread 74a, the right-hand thread 84a, and the right-hand thread RNa are used as the left-hand thread. The thread may be configured as a trapezoidal thread 76a, a trapezoidal thread 87a, a left thread 86a, a left thread 85a, and a left thread LNa as a right thread.

It is the side view which showed the side surface of the earth drill machine in 1st Embodiment of this invention. (A) is a side view of the bottom-up bucket in a state where the diameter has been reduced, and (b) is a side view of the bottom-up bucket in a state where the diameter has been enlarged. (C) is sectional drawing of the bottom-up bucket in the IIc-IIc line | wire of FIG.2 (b). FIG. 3 is an enlarged side view of a bottomed wing and a frame body in which a portion indicated by III in FIG. 2B is enlarged. (A) is the fragmentary sectional view which showed a part of cross section of the bottom wing and the frame in the IVa-IVa line of FIG. 3, and the frame pipe welded to the frame is illustrated. (B) is the fragmentary sectional view which showed a part of cross section of the bottom expansion blade and frame in the IVb-IVb line | wire of FIG. 3, and the bottom expansion blade pipe welded to the bottom expansion blade is illustrated. (A) is the top view of a thruster, (b) is the decomposition | disassembly side view which showed the decomposition | disassembly state of the thruster from the side surface. (A) is sectional drawing of a thruster inner, (b) is a bottom view of the thruster inner in the VIb-VIb line | wire of Fig.6 (a). (A) is the side view which showed the side surface of the rod, (b) is the bottom view which showed the bottom face of the rod. (A) is the partial side view which showed a part of link, (b) is the fragmentary sectional view of the link in the VIIIb-VIIIb line | wire of Fig.8 (a), (c) is FIG.8 ( It is a fragmentary sectional view of the link in the VIIIc-VIIIc line of a). (A) And (b) is the fragmentary sectional view which showed a part of cross section of the bottom expansion wing | blade and frame in 2nd Embodiment. (A) And (b) is the fragmentary sectional view which showed a part of cross section of the bottom expansion wing | blade and frame in 3rd Embodiment. (A) is the partial side view which showed a part of link, (b) is the fragmentary sectional view of the link in the XIb-XIb line | wire of Fig.11 (a), (c) is FIG.11 ( It is a fragmentary sectional view of the link in the XIc-XIc line of a).

Explanation of symbols

1 Earth drill machine 19 Bottom-up bucket 21 Hydraulic actuator (actuator, part of lifting mechanism)
30 Frame (main part)
32 Frame hinge (part of hinge structure)
33 Frame pipe (second hinge pipe)
35, 235, 335 Frame color (second color)
35a, 235a, 335a Frame collar hole (hole into which shaft is inserted)
40 Rod 44 Upper extension (part of extension)
45 Central heat treatment part (sliding part)
46 Lower extension (part of extension)
50 thruster (thruster, part of lifting mechanism)
51 Thruster lower (part of thruster body)
52 Thruster upper (part of thruster body)
53 Thruster inner 60 Expanded wing 62 Expanded wing hinge (part of hinge structure)
63 Expanded bottom wing pipe (first hinge pipe)
65,265,365 Expanded wing collar (first color)
65a, 265a, 365a Expanded wing collar hole (hole into which the shaft is inserted)
70,470 link 71 first clevis part (first clevis part)
72 Second clevis part (second clevis part)
74 Right female screw hole (first female screw hole)
76 Trapezoidal female screw hole (2nd female screw hole)
77a Injection hole 78 Discharge holes 80, 480 Main shaft portion (main shaft portion)
81 First shaft portion (first shaft portion)
82 Second shaft portion (second shaft portion)
84,484 Right male thread (first male thread)
85 Left male thread (third male thread)
86 Left female screw hole (third female screw hole)
87,487 trapezoidal male thread (second male thread)
87a, 487a Trapezoidal thread (group of threads, square thread)
D Diameter dimension F Shaft K Communication part T Opening dimension RN Right nut (first nut)
LN Left nut (second nut)
R Seal ring W, 2W1, 2W2, 3W1, 3W2 Welded part (welded part, part of welded part)

Claims (3)

A bottom expansion bucket that is inserted into a vertical hole having a constant cross-section excavated in the ground, and rotates and excavates the bottom of the vertical hole in order to expand the bottom of the vertical hole. A bottom wing that is pivotally connected, a rod that has an axial center, is configured in a columnar shape, and is disposed inside the main body, and is fitted around the rod and extends along the axial center of the rod. A bottom expansion bucket comprising: a thruster that is reciprocally moved; an actuator that applies a driving force to reciprocate the thruster; and a link that connects the thruster and the bottom expansion blade.
The thruster includes a thruster body portion configured in a cylindrical shape and through which the rod is inserted, and a thruster inner disposed between the thruster body portion and the rod,
The above-mentioned thruster inner is constituted by a material whose hardness is lower than a material constituting the outer surface of the rod, and is configured to be detachable from the thruster main body.   2. The widened bucket according to claim 1, wherein the thruster inner is configured in a cylindrical shape that is fitted into the thruster main body and fitted onto the rod. The rod includes a sliding portion where the thruster inner slides, and a pair of extended portions coupled to both ends of the sliding portion,
3. The widened bucket according to claim 1, wherein the sliding portion is made of a material having higher hardness than the pair of extended portions.

Images