JP2011214333A - Pile hole drill head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To visually confirm the oscillation of two excavating arms on the ground by transmitting the oscillations of the excavating arms through cams as upward/downward movement of one operation rod and observing this upward/downward movement on the ground.SOLUTION: The pile hole drill head 1 includes a coupling portion 18 to be coupled to a lower end portion of an excavating rod at the upper end of a head body 2 having the first excavating arm 14 and a second excavating arm 15; and a head operation body 3 continued thereto to confirm the positions of the excavating arms 14, 15. Extension excavation is performed by reversely rotating and largely oscillating the excavating arms 14, 15. The head operation body 3 is provided with cams 23-26. The oscillation of the excavating arm 14 is transmitted through the first cam 23 and the third cam 25, the oscillation of the excavating arm 15 is transmitted through the second am 24 and the third cam 25, and these oscillations are transmitted as upward/downward movement of one operation rod 27 through the third cam 25 and the fourth cam 26.

Description

  The applicant has proposed a drilling head in which a drilling arm provided with a drilling blade at the tip is swung by earth pressure to change a drilling diameter in the swinging direction (Patent Documents 1 and 2).

  Also, the applicant attaches a first sensor to the surface of the head body side of the excavating arm for the purpose of grasping the rocking state of the excavating arm on the ground, and when the excavating arm swings, A drilling head equipped with a combined second sensor has been proposed (Patent Document 1). This is based on the first sensor as a reference point, and in response to the swing of the excavating arm, the first sensor, which is the reference point, sends data on the ground where the first sensor is located within the swing range of the second sensor. The swing angle of the excavating arm can be confirmed on the ground.

  Furthermore, the applicant forms a stopper on the excavating arm so that the diameter of the excavation can be expanded more reliably and can be reduced easily thereafter, and a holding portion corresponding to the excavation diameter is provided on the stopper receiver that can be moved up and down by lifting operation from the ground. An excavation head that is formed and has a holding portion and a stopper corresponding to each other is also proposed (Patent Document 2). This is because when the excavating rod is rotated, the excavating arm swings to one side or the other side according to the direction of rotation, and the stopper angle is held by the stopper receiver, thereby maintaining a preset swing angle on one side or the other side. The pile hole can be reliably excavated with a predetermined excavation diameter set by the first oscillation angle and the second oscillation angle. Further, the state of the excavating arm can be visually observed from the ground by the raising / lowering state of the operation rod interlocked with the vertical movement of the stopper receiver.

JP 2008-150834 A JP 2008-179971 A

  With the above proposal, when excavating with a reliable enlarged diameter or visually checking the swing angle of the excavating arm, means that can be immediately confirmed on the spot with a member such as an operating rod is important ( Patent Document 2). In the case of the excavation head of Patent Document 2, it is necessary to connect two operation rods corresponding to each excavation arm to the stopper receiver.

  In general, since the digging is performed at a depth of 50 to 70 m from the ground, it is necessary to add the operation rod in order to dig while adding the excavating rod (usually 10 m or less per unit). Accordingly, the connection of the two operating rods, the operation work, and the like are complicated. In addition, various functions other than excavation are performed on the excavation head. For example, a container that collects the filling of the rooting portion and stores it as a sample may be provided. In this case, the opening and closing of the container is operated. The operation rod to be used is necessary, and there is a problem that the combined use becomes difficult. Furthermore, there is a demand for means for grasping the swing angle of the excavating arm on the ground while reducing the number of operating rods from the viewpoint of manufacturing cost.

  Therefore, the present invention solves the above-mentioned problem because the positions of the two excavating arms are indicated by raising and lowering one operating rod in combination with a plurality of cams.

That is, this invention is a pile hole excavation head characterized by having the connection part for connecting with the lower end part of an excavation rod, and having comprised it as follows.
(1) The excavation head is configured by connecting a head operation body having the connecting portion to an upper end of a head body having first and second excavation arms.
(2) The head main body is attached to the horizontal axis provided at the upper end of the head main body so that the first excavation arm and the second excavation arm are rotatable, and the head main body side to which the first excavation arm is attached The surface of the head main body side to which the second excavation arm is attached is the second side surface.
(3) In the head operating body, the surfaces of the head operating body corresponding to the first side surface and the second side surface of the head body are defined as a first side surface and a second side surface, respectively, and a side surface perpendicular to the first side surface is configured as a third side surface. It was set as the structure made into the side surface and the 4th side surface.
(4) The head operating body is configured to pivotally support the first cam on the first side of the head operating body, the second cam on the second side, and the third and fourth cams on the third side.
(5) The first cam and the second cam are configured to rotate according to the swing of the first operation arm and the second operation arm, respectively.
(6) The third cam is rotated according to the rotation of the first cam and the second cam, and the fourth cam is rotated according to the rotation of the third cam.
(7) The fourth cam is configured to be attached with an elevating member having an upper end projecting to the ground.

Moreover, in the above, it is a pile hole excavation head characterized by comprising all the following requirements.
(1) The first and second excavating arms have upper protrusions formed at their upper ends.
(2) A first protrusion and a second protrusion are formed on the first and second cams, respectively, and the first protrusions are in contact with and interlock with the upper protrusions.
(3) forming a first protrusion, a second protrusion and a third protrusion on the third cam, the first protrusion of the third cam contacting and interlocking with the second protrusion of the first cam; The second protrusion of the third cam contacts and interlocks with the second protrusion of the second cam.
(4) forming a first protrusion and a second protrusion on the fourth cam, wherein the first protrusion of the fourth cam contacts and interlocks with the third protrusion of the third cam; A lifting member is attached to the second protrusion.

Further, in the above, each upper protrusion has a protruding end on the left side, the apex of the protrusion is a reference point, the upper side is above the reference point, the lower side is formed below,
(1) The positions of the first excavation arm, the second excavation arm, and the elevating member when the projecting end portions contact the first projection of the first cam and the first projection of the second cam, respectively. As a reference position,
(2) When the excavation rod is rotated forward and the first and second excavation arms swing to one side to enter a small-diameter excavation state, the upper side portions are respectively the first protrusion of the first cam, the first In contact with the first projection of the two cams,
(3) When the excavation rod is rotated in the reverse direction and the first and second excavation arms are swung to the other side to be in a large-diameter excavation state, the lower side portions are respectively the first protrusion of the first cam, The pile hole excavation head is characterized in that the shape of the upper protrusion is set so as to contact and interlock with the first protrusion of the second cam.

  In another aspect of the invention, between the upper protrusion of the first excavation arm and the first protrusion of the first cam, and between the upper protrusion of the second excavation arm and the first protrusion of the second cam. A pile hole excavation head characterized by providing interlocking means.

Furthermore, another invention is a pile hole excavation head characterized by having a connecting portion for connecting to the lower end portion of the excavating rod and configured as follows.
(1) The excavation head is configured by connecting a head operation body having the connecting portion to an upper end of a head body having first and second excavation arms.
(2) A single lifting member having an upper end protruding above the ground is attached to the head operating body, and a plurality of cams for transmitting the movement of the first excavating arm and the movement of the second excavating arm to the lifting member are provided. A set is combined and attached to the head main body or the head operating body.

  According to the present invention, the rocked excavating arm is held at a predetermined angle by interlocking the excavating arm and the cam, and the cam interlocking is transmitted to the lifting member, and the swinging angle of the excavating arm is converted into the lifting / lowering of the lifting member. Therefore, there is an effect that the lifting member can be visually confirmed on the ground.

  In addition, since the swinging of both excavating arms can be confirmed with a single operating rod, the manufacturing cost can be reduced, and other aspects can be effectively utilized.

  Further, by providing the interlocking means between the excavating arm and the cam, the cam swing range is restricted, and there is an effect that the position of the excavating arm can be specified without the cam moving to an unexpected position.

It is a figure which shows the state of the excavation head in a reference position, Comprising: (a) The perspective view seen from the left front, (b) The perspective view seen from the right front. It is a figure which shows the state of the excavation head in a small diameter excavation state, Comprising: (a) The perspective view seen from the left front, (b) The perspective view seen from the right front. It is a figure which shows the state of the excavation head in a large diameter excavation state, Comprising: (a) The perspective view seen from the left front, (b) The perspective view seen from the right front. It is a front view of an excavation head, (a) The figure which shows the state of the excavation head in a reference position, (b) The figure which shows the state of the excavation head in a small diameter excavation state, (c) The state of the excavation head in a large diameter excavation state FIG. It is a right side view of the excavation head, (a) a diagram showing the state of the excavation head at the reference position, (b) a diagram showing the state of the excavation head in the small-diameter excavation state, (c) the excavation head in the large-diameter excavation state The figure which shows a state. It is a left side view of the excavation head, (a) a diagram showing the state of the excavation head at the reference position, (b) a diagram showing the state of the excavation head in the small-diameter excavation state, (c) the excavation head in the large-diameter excavation state The figure which shows a state. It is a rear view of an excavation head, (a) The figure which shows the state of the excavation head in a reference position, (b) The figure which shows the state of the excavation head in a small diameter excavation state, (c) The state of the excavation head in a large diameter excavation state FIG. It is a front view of an excavation head concerning other examples of the present invention, (a) a figure showing a state of an excavation head in a standard position, (b) a figure showing a state of an excavation head in a small diameter excavation state, (c) The figure which shows the state of the excavation head in a large diameter excavation state. It is a rear view of the excavation head concerning other examples of the present invention, (a) a figure showing a state of an excavation head in a standard position, (b) a figure showing a state of an excavation head in a small diameter excavation state, (c) The figure which shows the state of the excavation head in a large diameter excavation state. It is a front view of the excavation head concerning other one examples of the present invention, (a) The figure showing the state of the excavation head in the standard position, (b) The figure showing the state of the excavation head in the small diameter excavation state, c) The figure which shows the state of the excavation head in a large diameter excavation state. It is a rear view of the excavation head according to another embodiment of the present invention, (a) a diagram showing a state of the excavation head at a reference position, (b) a diagram showing a state of the excavation head in a small-diameter excavation state, c) The figure which shows the state of the excavation head in a large diameter excavation state.

  The pile hole excavating head 1 of the present invention has a connecting portion 18 for connecting to the lower end portion of the excavating rod 5 at the upper end of the head body 2 having the first excavating arm 14 and the second excavating arm 15. A head operating body 3 for confirming the positions of 14 and 15 is provided in series (FIG. 1).

  The head main body 2 has a first excavation arm 14 and a second excavation arm 15 rotatably attached to a horizontal shaft 13 provided at the upper end portion of the head main body 2, and the head main body 2 side to which the first excavation arm 14 is attached. The surface is the first side surface 6 and the surface on the head body 2 side to which the second excavation arm 15 is attached is the second side surface 7 (FIGS. 4 and 7). Further, the first and second excavating arms 14 and 15 have upper protrusions 17 formed at the upper ends thereof (FIG. 1).

  The head operating body 3 includes a first side face 19 and a second side face 20 respectively corresponding to the first side face 6 and the second side face 7 of the head body 2, and a side face perpendicular to the first side face 19. It was set as the 3rd side surface 21 and the 4th side surface 22 (FIG. 1, FIG. 6). Further, the first cam 23 is supported on the first side 19 of the head operating body 3, the second cam 24 is supported on the second side 20, and the third cam 25 and the fourth cam 26 are supported on the third side 21 (see FIG. 1).

  First protrusions 23a, 24a and second protrusions 23b, 24b are formed on the first cam 23 and the second cam 24, respectively, and the first protrusions 23a, 24a are in contact with the upper protrusions 17, respectively. The configuration is linked. Therefore, the first cam 23 and the second cam 24 rotate according to the swinging of the first operating arm 14 and the second operating arm 15 (FIGS. 4 to 7).

  A first protrusion 25 a, a second protrusion 25 b, and a third protrusion 25 c are formed on the third cam 25, and the first protrusion 25 a of the third cam 25 contacts the second protrusion 23 b of the first cam 23. The second protrusion 25b of the third cam 25 is in contact with the second protrusion 24b of the second cam 24 to be interlocked. Accordingly, the third cam 25 rotates according to the rotation of the first cam 23 and the second cam 24 (FIG. 5).

  A first protrusion 26 a and a second protrusion 26 b are formed on the fourth cam 26, and the first protrusion 26 a of the fourth cam 26 contacts and interlocks with the third protrusion 25 c of the third cam 25. The operation rod 27 is attached to the second protrusion 26b of the cam 26, and the upper end thereof protrudes to the ground (FIG. 1). Therefore, the fourth cam 26 rotates according to the rotation of the third cam 25 (FIG. 5).

  An embodiment of the present invention will be described with reference to FIGS.

1. Configuration of Excavation Head 1 The excavation head 1 is configured as follows (FIG. 1).

1-1 Head body 2

  The head main body 2 is formed by connecting a square columnar head operating body 3 to the upper end of a square columnar base 2a, and forming a flat bulging portion 4 continuously with the lower edge of the base 2a. The base portion 2a has one side surface facing the first side surface 6 and the second side surface 7 and the other side surfaces 8 and 8 facing each other adjacent to the one side surface.

  A horizontal shaft 13 is formed to protrude from the first side surface 6 and the second side surface 7 of the base portion 2 a of the head body 2. The base end portions of the first excavation arm 14 and the second excavation arm 15 are attached to the horizontal shaft 13 in a swingable manner. The horizontal shaft 13 may be either an integral shaft or a divided shaft as long as the first side surface 6 and the second side surface 7 coincide with each other. Further, the horizontal shaft 13 only needs to be formed so that the first and second excavating arms 14 and 15 can be rotated. Therefore, the horizontal shaft 13 is provided on the excavating arms 14 and 15 and the bearing is provided on the head body 2. Also good.

  The base portion 2a is dimensioned so that the widths of the other side surfaces 8 and 8 are reduced so that the first side surface 6 and the second side surface 7 approach toward the lower side, and continuously expands at the lower end of the base portion 2a. It reaches the exit part 4. The bulging portion 4 bulges in the horizontal direction and is formed so that the widths of the first side surface 6 and the second side surface 7 are increased. The lower edge of the bulging portion 4 is formed in an arc along the swinging trajectory of the excavating arms 14 and 15, and fixed excavating blades 10 and 10 are attached to the lower edge downward (FIGS. 1 and 4). Further, the stirring blades 11 and 12 are inclined on the other side surfaces 8 and 8 of the head main body 2 and the mounting heights are different on the other side surfaces 8 and 8 (the stirring blade 11 is positioned above the stirring blade 12). Attached) (FIG. 1).

  A first stopper 9a that restricts swinging of the excavating arm during normal rotation is provided on the upper end of the head body 2 on the first side surfaces 6 and 7 side. Moreover, the 2nd stopper 9b which controls the rocking | fluctuation at the time of reverse rotation is provided (FIG. 4).

1-2 Excavating arms 14, 15

  Each of the first and second excavating arms 14 and 15 has a base end portion with a large diameter around the horizontal axis, a middle portion with a small width, and a wide end portion. The excavating arms 14 and 15 are deformed along the deformation of the surface shape of the first side surface 6 and the second side surface 7 of the head body 2, and the shape changes of the base portion 2 a and the bulging portion 4 of the head body 2 (towards downward). (The first side surface 6 and the second side surface 7 are formed so as to approach each other), and the excavating arms 14 and 15 are bent so as to approach each other, and conversely, outward at the lower part of the bulging portion 4. The excavating blade 16 is protruded in such a direction (so that the first excavating arm 14 and the second excavating arm 15 are separated) (FIGS. 1, 5, and 6).

  The first and second excavating arms 14 and 15 form upper protrusions 17 and 17 at their upper ends, respectively, and each of the upper protrusions 17 and 17 has a protruding protrusion 17a on the left side. Using the apex of the portion 17a as a reference, an upper side 17b is formed on the upper side of the reference point, and a lower side 17c is formed on the lower side (FIGS. 1 and 2).

1-3 Head operating body 3

  The head operating body 3 has a quadrangular shape, and has a connecting portion 18 for connecting to the lower end portion of the excavation rod 5 at the upper end thereof, and is connected to the upper end of the head main body 2. The head operating body 3 has the first side face 19 and the second side face 20 corresponding to the first side face 6 and the second side face 7 of the head main body 2, respectively, and the first side face 19 of the head operating body 3. The side surfaces perpendicular to the third side surface 21 and the fourth side surface 22 are configured.

1-4 Cam

  The first cam 23 is on the first side 19 of the head operating body 3 with the axis A, the second side 20 with the second cam 24 on the axis B, the third side 21 with the third cam 25 on the axis C, and the third side. The fourth cam 26 is pivotally supported on the axis 21 by the axis D. Each of the axes A, B, C, and D is protruded at right angles to the side surface that is supported.

  First protrusions 23a, 24a and second protrusions 23b, 24b are formed on the first cam 23 and the second cam 24, respectively, and the first protrusions 23a are in contact with the upper protrusions 17, 17, respectively. It is designed to be linked.

  A first protrusion 25a, a second protrusion 25b, and a third protrusion 25c are formed on the third cam 25. The first protrusion 25 a of the third cam 25 contacts and interlocks with the second protrusion 23 b of the first cam 23, and the second protrusion 25 b of the third cam 25 is in contact with the second protrusion 24 b of the second cam 24. It comes to contact and interlock.

  A first protrusion 26 a and a second protrusion 26 b are formed on the fourth cam 26. The first protrusion 26 a of the fourth cam 26 contacts and interlocks with the third protrusion 25 c of the third cam 25, and an operation rod 27 is attached to the second protrusion 26 b of the fourth cam 26. The raising / lowering position of the operation rod 27 can be confirmed on the ground by the rotation. The positions of the first to fourth cam shafts are as follows.

(1) The axis A of the first cam 23 is substantially directly above the axis position (horizontal axis 13) of the excavating arms 14 and 15, and is coaxial with the axis B of the second cam 24. The axis A is substantially the same height as the third cam 25 and substantially C, and is positioned below the axis D of the fourth cam 26.
(2) The axis B of the second cam 24 is substantially directly above the axis position (horizontal axis 13) of the excavating arms 14 and 15, and is coaxial with the axis A of the first cam 23. The axis B is substantially the same height as the axis C of the third cam 25 and is positioned below the axis D of the fourth cam 26.
(3) The axis C of the third cam 25 is above the axis position (horizontal axis 13) of the excavating arms 14 and 15, and is substantially the same height as the axes A and B of the first cam 23 and the second cam 24. Located in. Further, it is located below the axis D of the fourth cam 26.
(4) The axis D of the fourth cam 26 is located above the axes A and B of the first cam 23 and the second cam 24 and is located on the upper left side of the axis C of the third cam 25.

2. Use of drilling head 1

Subsequently, the use of the excavation head 1 of the present invention will be described.
A drilling rod 5 is attached to an excavator (not shown), a connecting portion 18 of the drilling head 1 is attached to a lower end of the drilling rod 5, an operation rod 27 is extended upward along the drilling rod 5, and a pile hole is formed. Excavate. Assuming that the first and second excavation arms 14 and 15 are in a suspended state as the reference positions of the excavation arms 14 and 15 and the cams 23 to 26, the relationship between the shafts and the protrusions in the cams 23 to 26 is as follows. It becomes like this.

2-1 Reference position

(1) The first protrusion 23 a of the first cam 23 is formed downward on the left side of the axis A of the first cam 23. The second protrusion 23b is formed in the right direction below the axis A of the first cam 23 (FIG. 4A).

(2) The first protrusion 24 a of the second cam 24 is formed downward on the left side of the axis B of the second cam 24. The second protrusion 24b is formed in the left direction above the axis B of the second cam 24 (FIG. 7A).

(3) The first protrusion 25 a of the third cam 25 is formed in a diagonally lower left direction with respect to the axis C of the third cam 25. Further, the second protrusion 25b is formed in an oblique upper right direction with respect to the axis D of the third cam 25, and the third protrusion 25c is formed substantially directly above the axis C of the third cam 25 (FIG. 5 ( a)).

(4) The first protrusion 26 a of the fourth cam 26 is formed downward on the right side of the axis D of the fourth cam 26. The second protrusion 26b is formed in the right direction below the axis D of the fourth cam 26 (FIG. 5A).

(5) Moreover, the positional relationship of the protrusions between the cams 23 to 26 is as follows.

The second protrusion 23b of the first cam 23 is in contact with the upper surface of the first protrusion 25a of the third cam 25 (FIG. 1A).
The second protrusion 24b of the second cam 24 is in contact with the lower surface of the second protrusion 25b of the third cam 25 (FIG. 1 (b)). The second protrusion 24b of the second cam 24 is higher in position than the second protrusion 23b of the first cam 23 (FIG. 1B).
The third protrusion 25c of the third cam 25 and the first and second protrusions 26a, 26b of the fourth cam 26 are higher in position than the second protrusions 23b, 24b of the first and second cams (FIG. 1 ( a), (b)).

2-2 Small-diameter excavation position

(1) When the excavation rod 5 is rotated forward, the first excavation arm 14 swings to one side as indicated by an arrow 28 due to earth pressure generated in the excavation blades 16 and the excavation arms 14 and 15, and the second excavation arm 15. Swings to one side as shown by arrow 28 (FIGS. 4B and 7B). At this time, the upper protrusions 17 and 17 of the excavating arms 14 and 15 hit the first stoppers 9a and 9a, respectively, to maintain the swing angle at this time.

(2) The relationship between the shaft and the protrusion in each cam at this time is as follows.
The first protrusion 23a of the first cam 23 moves leftward from the reference position. Further, the second protrusion 23b moves downward from the reference position (FIG. 4B).
The first protrusion 24a of the second cam 24 moves to the left from the reference position. Further, the second protrusion 24b moves upward from the reference position (FIG. 7B).
The first protrusion 25a of the third cam 25 moves (rotates) to the right from the reference position. Further, the second protrusion 25b moves (rotates) leftward from the reference position, and the third protrusion 25c moves (rotates) leftward from the reference position (FIG. 5B).

(3) Further, the positional relationship of the protrusions between the cams is as follows.
The second protrusion 23b of the first cam 23 is in contact with the upper surface of the first protrusion 25a of the third cam 25 (FIG. 2A).
-The 2nd protrusion 24b of the 2nd cam 24 is contacting in the surface below the 2nd protrusion 25b of the 3rd cam 25 (FIG.2 (b)).
The position of the second protrusion 24b of the second cam 24 is higher than that of the second protrusion 23a of the first cam 23 (FIG. 2).
The position of the third protrusion 25c of the third cam 25 and the second protrusion 26b of the fourth cam 26 is higher than the positions of the second protrusions 23b and 24b of the first cam 23 and the second cam 24 (FIG. 2).
-The 2nd protrusion 24b of the 2nd cam 24 is located in the substantially same height as the 1st protrusion 26a of the 4th cam 26 (FIG. 2).

(4) Therefore, in conjunction with the third protrusion 25c of the third cam 25, the first protrusion 26a of the fourth cam 26 moves to the left, and the second protrusion 25b moves downward. At this time the operating rod 27 is lowered in conjunction with the second projection 25b of the fourth cam (Figure 5b), if it is confirmed that the operating rod 27 on the ground is lowered, predetermined drilling diameter D ₁ It can be confirmed that the pile hole has been excavated.

2-3 Large-diameter excavation position

(1) After excavating to a predetermined depth, when the excavating rod 5 stops rotating and then the excavating rod 5 is reversely rotated, the first excavating arm 14 is caused by the earth pressure generated in the excavating blade 16 and the excavating arms 14 and 15. The second excavating arm 15 swings in the direction of arrow 29 (FIGS. 4C and 7C). At this time, the upper protrusions 17 and 17 of the excavating arms 14 and 15 hit the second stoppers 9b and 9b, respectively, and the swing angle at this time is maintained.

(2) The relationship between the shaft and the protrusion in each cam at this time is as follows.
The first protrusion 23a of the first cam 23 moves to the right from the reference position. The second protrusion 23b moves upward from the reference position (FIG. 4C).
The first protrusion 24a of the second cam 24 moves to the right from the reference position. Further, the second protrusion 24b moves downward from the reference position (FIG. 7C).
The first protrusion 25a of the third cam 25 moves (rotates) upward from the reference position. Further, the second protrusion 25b moves (rotates) downward from the reference position, and the third protrusion 25c moves (rotates) to the right of the reference position (FIG. 5C).
-The 4th cam 26 1st protrusion 26a moves to a right direction rather than a reference position, and the 2nd protrusion 26b moves upwards rather than a reference position (Drawing 5 (c)).

(3) Moreover, the positional relationship of the protrusions between the cams is as follows.
The second protrusion 23b of the first cam 23 is in contact with the upper surface of the first protrusion 25a of the third cam 25 (FIG. 3A).
-The 2nd protrusion 24b of the 2nd cam 24 is contacting in the surface below the 2nd protrusion 25b of the 3rd cam 25 (FIG.3 (b)).
The second protrusion 23b of the first cam 23 is higher in position than the second protrusion 24b of the second cam 24 (FIG. 3).
The positions of the third protrusion 25c of the third cam 25 and the first protrusion 26a and the second protrusion 26b of the fourth cam 26 are greater than the positions of the second protrusions 23b and 24b of the first cam 23 and the second cam 24. High (Figure 3).

(4) Accordingly, in conjunction with the third protrusion 25c of the third cam 25, the first protrusion 26a of the fourth cam 26 moves to the right, and the second protrusion 25b moves upward. At this time, since the operating rod 27 rises in conjunction with the second protrusion 25b of the fourth cam (FIG. 5C), if it can be confirmed that the operating rod 27 is raised on the ground, a predetermined excavation diameter is obtained. pile holes in D ₂ can be confirmed to have been drilled.

(5) From the above, whether the first excavation arm 14 and the second excavation arm 15 are in the position for small-diameter excavation (FIG. 2), the position for large-diameter excavation (FIG. 3), or drooped downward Whether it is in the state (reference position) (FIG. 1) can be grasped by checking the rotation direction of the excavating rod 5 and whether the operating rod 27 is in the raised state or the lowered state. Therefore, by grasping the state of the operation rod 27 on the ground, the states of the first excavation arm 14 and the second excavation arm 15 can be recognized more reliably.

3. Other examples

(1) In the embodiment, interlocking means may be provided between the first excavation arm 14 and the first cam 23 and between the second excavation arm 15 and the second cam 24.
As shown in FIGS. 8 and 9, the interlocking means is provided with protrusions 30, 30 on the upper protrusion 17 of the first excavating arm 14 and the first protrusion 23 a of the first cam 23, and the protrusion 30 has a plate-like shape. The interlocking plate 31 is loosely attached with some play. Similarly, a protrusion 30 is provided on the upper protrusion 17 of the second excavating arm 15 and the first protrusion 24a of the second cam 24, and the protrusion 30 is plate-like interlocking. The plate 31 is configured to be loosely attached with some play.
As shown in FIGS. 10 and 11, the interlocking means is provided with hooks 32, 32 on the upper protrusion 17 of the first excavating arm 14 and the first protrusion 23 a of the first cam 23. 33, similarly, hooks 32, 32 are provided on the upper protrusion 17 of the second excavating arm 15 and the first protrusion 24 a of the second cam 24, and the wire 33 is attached to the hook 32.
With each of the above-described configurations, the upper protrusion 17 of the first excavation arm 14 and the first protrusion 23a of the first cam 23 are always in contact with each other or are not greatly separated from each other. The first protrusion 24a of the second cam 24 comes into contact with the second cam 24 when necessary. Therefore, the swing range of each of the first cam 23 and the second cam 24 is restricted, and the first cam 23 and the second cam 24 are not disposed at unexpected positions. The position of the arm 15 can be specified reliably.

(2) Further, the connecting means (the interlocking plate 31 or the hook 32) is provided between the first cam 23 and the third cam 25, between the second cam 24 and the third cam 25, and between the third cam 25 and the third cam 25. It can also be directed between the four cams (not shown).

DESCRIPTION OF SYMBOLS 1 Pile hole excavation head 2 Head main body 2a Head main body 3 Head operation body 4 Swelling part 5 Excavation rod 6 Head main body first side surface 7 Head main body second side surface 8 Head main body other side surface 9a First stopper 9b First Two stoppers 10 Fixed excavating blade 11 Stirring blade 12 Stirring blade 13 Horizontal shaft 14 First excavating arm 15 Second excavating arm 16 Excavating blade 17 Upper projecting portion 17a Projecting end portion 17b Upper side 17c Lower side 18 Connecting portion 19 First side surface of the head operating body 20 Second side surface 21 of the head operating body Third side surface 22 of the head operating body Fourth side surface 23 of the head operating body First cam 23a First projection portion 23b of the first cam Second projection portion 24 of the first cam Second cam 24a First projection 24b of the second cam Second projection 25 of the second cam Third cam 25a First projection 25b of the third cam Second projection 25c of the third cam Third projection 26 of the third cam 4th cam 2 Second projection 27 the operating rod 30 projecting 31 interlock plate of the first peak 26b fourth cam a fourth cam (interlock means)
32 hook (interlocking means)
33 wire (interlocking means)
A Axis of first cam B Axis of second cam C Axis of third cam D Axis of fourth cam

Claims (5)

A pile hole excavation head having a connecting portion for connecting to the lower end portion of the excavating rod and configured as follows.
(1) The excavation head is configured by connecting a head operation body having the connecting portion to an upper end of a head body having first and second excavation arms.
(2) The head main body is attached to the horizontal axis provided at the upper end of the head main body so that the first excavation arm and the second excavation arm are rotatable, and the head main body side to which the first excavation arm is attached The surface of the head main body side to which the second excavation arm is attached is the second side surface.
(3) In the head operating body, the surfaces of the head operating body corresponding to the first side surface and the second side surface of the head body are defined as a first side surface and a second side surface, respectively, and a side surface perpendicular to the first side surface is configured as a third side surface. It was set as the structure made into the side surface and the 4th side surface.
(4) The head operating body is configured to pivotally support the first cam on the first side of the head operating body, the second cam on the second side, and the third and fourth cams on the third side.
(5) The first cam and the second cam are configured to rotate according to the swing of the first operation arm and the second operation arm, respectively.
(6) The third cam is rotated according to the rotation of the first cam and the second cam, and the fourth cam is rotated according to the rotation of the third cam.
(7) The fourth cam is configured to be attached with an elevating member having an upper end projecting to the ground. The pile hole excavation head according to claim 1, comprising all the following requirements.
(1) The first and second excavating arms have upper protrusions formed at their upper ends.
(2) A first protrusion and a second protrusion are formed on the first and second cams, respectively, and the first protrusions are in contact with and interlock with the upper protrusions.
(3) forming a first protrusion, a second protrusion and a third protrusion on the third cam, the first protrusion of the third cam contacting and interlocking with the second protrusion of the first cam; The second protrusion of the third cam contacts and interlocks with the second protrusion of the second cam.
(4) forming a first protrusion and a second protrusion on the fourth cam, wherein the first protrusion of the fourth cam contacts and interlocks with the third protrusion of the third cam; A lifting member is attached to the second protrusion. Each upper protrusion has a protruding end on the left side, the apex of the protruding end as a reference point, an upper side above the reference point, a lower side on the lower side,
(1) The positions of the first excavation arm, the second excavation arm, and the elevating member when the projecting end portions contact the first projection of the first cam and the first projection of the second cam, respectively. As a reference position,
(2) When the excavation rod is rotated forward and the first and second excavation arms swing to one side to enter a small-diameter excavation state, the upper side portions are respectively the first protrusion of the first cam, the first In contact with the first projection of the two cams,
(3) When the excavation rod is rotated in the reverse direction and the first and second excavation arms are swung to the other side to be in a large-diameter excavation state, the lower side portions are respectively the first protrusion of the first cam, The pile hole excavation head according to claim 1 or 2, wherein the shape of the upper protrusion is set so as to contact and interlock with the first protrusion of the second cam.   Interlocking means are provided between the upper protrusion of the first excavation arm and the first protrusion of the first cam, and between the upper protrusion of the second excavation arm and the first protrusion of the second cam. The pile hole excavation head according to claim 3, wherein: A pile hole excavation head having a connecting portion for connecting to the lower end portion of the excavating rod and configured as follows.
(1) The excavation head is configured by connecting a head operation body having the connecting portion to an upper end of a head body having first and second excavation arms.
(2) A single lifting member having an upper end protruding above the ground is attached to the head operating body, and a plurality of cams for transmitting the movement of the first excavating arm and the movement of the second excavating arm to the lifting member are provided. A set is combined and attached to the head main body or the head operating body.

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