JP3457559B2 - Expanded bottom bucket - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bottom expanding bucket for excavating the bottom of a vertical hole to be excavated by an earth drill.

[0002]

2. Description of the Related Art A ground drill for excavating a vertical hole for foundation pile driving is to excavate a vertical hole at the lower end of a kerry bar to a predetermined depth with a bucket for axial excavation, and then use the bucket for axial excavation as a bottom expanding bucket. Instead, the bottom of the hole is enlarged and excavated in a tapered shape. The bottom expanding bucket is provided with bottom expanding blades with excavating claws that are opened and closed by a hydraulic cylinder (hereinafter referred to as a bottom expanding cylinder) on the side surface of the bucket, and the bottom expanding cylinder supplies pressure oil from the base machine via a hydraulic hose. The bottom expanding blade is opened and closed by receiving and expanding. Such expanding bottom buckets are disclosed in Japanese Examined Patent Publication No. 63-65797 and Japanese Examined Patent Publication 3-47.
No. 398 and Japanese Patent Publication No. 3-77359.

[0003]

According to the above-mentioned conventional bottom expanding bucket, if the maximum bottom expanding diameter is increased without changing the diameter when accommodating the bottom expanding blade, in order to increase the bottom expanding rate, the bottom expanding blade is enlarged. The height of the bucket and the length of the bottom expanding blade in the height direction are increased due to the restriction of the angle of the inclined portion of. However, since the bottom expanding blades are formed in a tapered shape, the bottom expanding blades are tilted so that the upper part of the bottom expanding blades is closer to the center and the lower part of the bottom expanding blades is also accommodated in the bucket when stored in the bucket. It is stored in a posture and its tilt angle cannot be changed, so if the length of the bottom expanding blade increases, the top of the bottom expanding blade interferes with the frame of the bucket when the bottom expanding blade is stored in the bucket, and the bottom expanding blade is stored within the specified diameter. There was a problem that it could not be done.

In view of the above problems of the prior art, it is an object of the present invention to provide a bottom expanding bucket having a structure capable of increasing the maximum bottom expanding diameter without changing the bucket diameter when storing the bottom expanding blades.

[0005]

According to the bottom expanding bucket of claim 1, the bottom expanding blade of the bottom expanding bucket for earth drill is divided into a plurality of stages in the height direction, and each of the divided bottom expanding blades is independently provided around the rotation axis. It is rotatably attached, and the rotation angle from the maximum diameter expansion state of the topmost bottom expanding blade to the storage state in the bucket is set to be smaller than the rotation angle of the bottom expanding blades of the stages below the topmost expanding blade. Is characterized by.

As described above, the bottom expanding bucket is divided into a plurality of stages in the height direction, and the rotation angle from the maximum expanded state of the top expanding blade to the storage state in the bucket is lower than that of the top expanding blade. If the rotation angle of the bottom expanding blade of the step is set to be smaller than the rotation angle, it is possible to prevent the upper end of the bottom expanding blade of the uppermost step from coming into contact with the frame of the bucket in the storage state in the bucket.

In the bottom expanding bucket of claim 2, the bottom expanding blades of the bottom expanding bucket for earth drills are divided into upper and lower parts, and the upper and lower bottom expanding blades are independently rotatably mounted around a rotation axis and connected to an opening / closing device for the bottom expanding bucket. The drive bottom blade is on the lower side, and the driven bottom blade is on the upper side.When the bottom blade is opened, the rotary power transmission part for opening is provided at the position where the driven bottom blade starts to rotate later than the drive bottom blade. It is characterized by that.

In this way, the bottom expanding bucket is divided into upper and lower parts, and the lower bottom expanding blade is connected to the opening / closing device.
The driven bottom blade is closed by providing a closed bottom power transmission section at the position where the driven bottom blade starts to rotate with a delay relative to the drive bottom blade when the bottom blade is opened. When opening from the state, the driven bottom expanding blade starts to open after rotating to some degree in the opening direction of the drive bottom expanding blade, so that the entire driven bottom expanding blade does not rotate closer to the bucket center side than the upper end of the drive bottom expanding blade, and the driven bottom expanding blade does not move. The upper ends of the wings are prevented from contacting the bucket frame.

Further, since the bottom expanding portion is formed in a tapered shape, the amount of excavation is larger in the lower part of the bottom expanding part and smaller in the upper part. Therefore, when the bottom expanding blade is opened, the driven bottom expanding blade is opened to some extent and then the driven bottom expanding is performed. It is practical to start opening the wings, and since the drive expansion blade is larger in scale including the support part than the upper driven expansion blade on the upper side, a storage space is required. With this configuration, the drive expanding blade and the driven expanding blade can be compactly housed in the bucket without increasing the diameter of the bucket.

A bottom expanding bucket according to a third aspect of the present invention is the one according to the first or second aspect, in which a rotary power transmission portion for transmitting the rotation of the driving bottom expanding blade to the driven bottom expanding blade is provided independently for opening and closing the bottom expanding blade. It is characterized by

As described above, by independently providing the rotary power transmission parts, the delay of the driven bottom expanding blades due to the opening and closing of the driving bottom expanding blades can be individually set, and the degree of freedom in design is increased.

A bottom expanding bucket according to a fourth aspect of the present invention is characterized in that, in any one of the first to fourth aspects, the axis of the rotary shaft of each of the divided bottom expanding blades is matched.

In this way, by making the axes of the rotating shafts of the bottom expanding blades coincide with each other (either one rotating shaft is commonly used for the bottom expanding blades, or the axes of a plurality of rotating shafts are matched). , It is possible to eliminate the risk of bending of the bottom expanding blade and unevenness of the excavated surface.

A bottom expanding bucket according to a fifth aspect of the present invention is, in any one of the first to fourth aspects, wherein a guide plate for introducing earth and sand is fixed to the rear side of the bottom expanding blade at the lowermost stage, and the guide plate and the body portion are connected to each other. Another feature is that one or more guide plates for introducing earth and sand are interposed between the inner surface and the inner surface so as to be relatively movable in the opening / closing direction.

By thus dividing the guide plates, the individual guide plates can be shortened, and the length of the individual guide plates in the opening / closing direction is prevented from becoming long even if the bottom enlargement ratio is increased. You can

According to a sixth aspect of the present invention, there is provided a bottom expanding bucket according to any one of the first to fourth aspects, in which a first guide plate for introducing earth and sand is fixed to the rear side of the bottom expanding blade, and the first guide plate and the body portion are fixed. The second for earth and sand introduction between and
The guide plate is interposed so as to be relatively movable in the opening / closing direction with respect to the body portion and the first guide plate, and the relative movement limit positions in the opening direction and the closing direction between the first guide plate and the second guide plate are respectively set. A stopper for limiting is provided, and a stopper is provided between the rear portion of the second guide plate and the body portion to prevent a gap from being generated between the front edge of the body portion and the second guide plate. It is characterized in that a stopper is provided between the second guide plate and the body portion to restrict the limit position of the second guide plate in the closing direction.

As described above, the guide plate for introducing the earth and sand into the bucket is relatively moved in the opening / closing direction between the first guide plate fixed to the rear portion of the bottom expanding blade and the body of the bucket body and the first guide plate. By freely interposing it and dividing it into the second guide plate, the individual guide plates can be shortened, and even if the bottom enlargement ratio is increased, the length of the individual guide plates in the opening / closing direction is prevented from becoming long. be able to.

The stopper provided between the first guide plate and the second guide plate plays a role of interlocking the second guide plate with the movement of the first guide plate in the opening / closing direction by the opening / closing device such as the bottom expanding cylinder. . The stopper between the rear part of the second guide plate and the body part of the bucket body should have a gap between the rear edge of the second guide plate and the front end edge of the body part even when the bottom expanding blade is wide open. Prevent.

Further, if a stopper for restricting the limit position of the second guide plate in the closing direction is provided, the position where the second guide plate enters the bucket body is restricted, so that the bucket body and the second guide plate are separated from each other. Interference is prevented.

According to a seventh aspect of the present invention, there is provided a bottom expanding bucket according to the fifth or sixth aspect, in which the inside and the outside of the adjacent guide plates are arranged between
Alternatively, a guide portion is provided between the body portion and the guide plate to regulate relative movement in the vertical and inward and outward directions.

As described above, by regulating the vertical and inward and outward positions of the guide plate, the guide plate can be opened and closed without rattling.

According to an eighth aspect of the present invention, in the bottom expanding bucket according to the seventh aspect, the guide portion comprises groove-shaped guide portions provided above and below one guide plate, and the groove-shaped guide portion has the other guide plate. The upper and lower guide portions are slidably fitted, and the end portions of the groove-shaped guide portions are cut away to form the earth and sand discharging portion.

As described above, by constructing the earth and sand discharging portion by omitting the end portion of the groove-shaped guide portion, accumulation of earth and sand in the groove-shaped guide portion is prevented and the guide plate is slid smoothly. be able to.

According to a ninth aspect of the present invention, in the bottom expanding bucket according to the seventh or eighth aspect, a projecting guide portion is provided in an opening / closing direction on a surface of the guide plate adjacent to the inside / outside or a guide plate of the body portion facing each other. The guide plate or the body portion facing the guide portion is provided with a guide portion slidably fitted to the projecting guide portion.

As described above, by forming the concave-convex fitting structure between the guide plates or between the guide plate and the body portion, it is possible to eliminate rattling in the vertical direction and to smoothly slide the guide plate. .

[0026]

1 is a front view showing an embodiment of a bottom expanding bucket according to the present invention, FIG. 2 is a rear view thereof, and FIG.
2 is a cross-sectional view taken along the line H-H in FIG. 1 showing the closed bottom blade in a closed state, and FIG. 4 is a cross-sectional view taken along the line C-C in FIG. Figure 1
4 to 4, reference numeral 1 denotes a central shaft connected to a kelly bar (not shown) through a stabilizer (not shown) for preventing runout during excavation, and a vertical frame 2 is provided below the central shaft 1. Is fixed. Lateral frames 3 protruding laterally are fixed to these vertical frames 2 in multiple stages. At both ends of each horizontal frame 3,
Bearings 4 are provided, and a support arm that supports a drive expanding blade 6A, which is a lower expanding blade, and a driven expanding blade 6B, which is an upper expanding blade, on a single rotating shaft 5 fixed to each bearing 4. The base ends of 7A and 7B are rotatably attached.

Reference numeral 8 denotes a bottom expanding cylinder composed of a hydraulic cylinder provided as an opening / closing device for opening / closing the drive expanding blade 6A. The bottom expanding cylinder 8 is a lateral arm on the side opposite to the supporting arm 7A and the mounting side of the supporting arm 7A. It is attached between the end of the frame 3. A body 9 for accommodating earth and sand is fixed to the lower end of a rotary shaft 5 fixed to the bearings 4 at both ends of the horizontal frame 3. The central shaft 1, the vertical frame 2, the horizontal frame 3, and the body portion 9 constitute a bucket body 10. Reference numeral 11 is a bottom lid of the bucket.

As shown in FIG. 5 which is a view taken in the direction of arrow B in FIG.
Between the drive expanding blade 6A and the driven expanding blade 6B, the turning force when the expanding blade opens in the direction of the arrow X is formed by the projection 12 at the upper end of the drive expanding blade 6A and the projection 13 at the lower end of the driven expanding blade 6B. The transmission unit 14 is configured. A gap G is set between the protrusions 12 and 13 when the bottom expanding blade is fully closed.

FIG. 2 and A— in FIG. 2 showing the closed bottom blade closed state.
As shown in FIG. 6 which is a cross-sectional view taken along the line A, the brackets 15 and 16 that come into contact with each other when closing the bottom expanding vane are respectively attached to the support arm 7A at the upper end of the drive expanding vane 6A and the support arm 7B at the lower end of the driven expanding vane 6B. Is fixed, and these brackets 15 and 16 constitute a turning power transmission portion 17 for closing.

In FIG. 3, 20 is a scraper rotatably attached to the rotary shaft 5, 20a is an auxiliary scraper rotatably attached to the tip thereof, and 21 is a connecting bottom expanding blade 6A and the main scraper 20. It is a link. In FIG. 3, when the bottom expanding blade 6A opens as shown by the arrow R, the scraper 20 also opens in the direction of the arrow r by the link 21,
The auxiliary scraper 20a rotates in the direction of arrow s by the pressure of the earth and sand and the resistance of the ground to introduce the earth and sand into the bucket. On the contrary, when the bottom expanding blade 6A is closed in the anti-R direction, the main scraper 20 and the auxiliary scraper 20a are respectively in the anti-r direction,
It rotates in the counter s direction and stores the earth and sand remaining in the scrapers 20, 20a in the bucket.

In this configuration, when the bucket is rotated while extending the bottom expanding cylinder 8 from the closed state of the bottom expanding blade shown in FIG. 6, the drive expanding blade 6A in FIG.
The projection 12 of the drive expanding blade 6A moves in the direction
Until it abuts on the protrusion 13 of B, only the drive expansion blade 6A projects from the inside of the bucket and excavates only the lower part of the bottom of the vertical hole to be excavated to the predetermined diameter. When the projections 12 and 13 are in contact with each other, as shown in FIG. 7, the cutter 6c of the drive expansion blade 6A and the cutter 6d of the driven expansion blade 6B are aligned in series. In this way, only the drive expansion blade 6A excavates up to a certain excavation diameter. In bottom-drilling, the bucket is rotated while gradually expanding the amount of bottom-blading bulge,
Since the lower hole wall is excavated, only the drive expanding blade 6A needs to be expanded at the beginning of bottom expanding. By further extending the bottom expanding cylinder 8 from this state, the rotational force of the drive expanding blade 6A is transmitted to the driven expanding blade 6B via the projections 12 and 13, and the drive expanding blade 6A and the driven expanding blade 6B are excavated integrally. Drill while expanding the diameter.

When the earth and sand in the bucket are almost filled in this way, the earth and sand in front of the drive expanding blade 6A in the rotational direction are taken in while the bottom expanding cylinder 8 is contracted.
At this time, the bottom expanding cylinder 8 is contracted at a stretch to store the drive expanding blade 6A and the driven expanding blade 6B in the bucket.

Before the storage of the bottom expanding blades 6A, 6B as described above, as shown in FIG. 7, since the brackets 15, 16 constituting the turning power transmission portion for closing are separated from each other, the initial closing operation is performed. In, only the drive expanding blade 6A moves in the closing direction. When the bracket 15 of the drive expanding blade 6A comes into contact with the bracket 16 of the driven expanding blade 6B, thereafter, the drive expanding blade 6A and the driven expanding blade 6B are integrally closed.

FIG. 8 shows the rotation angle .theta.1 of the drive bottom expanding blade 6A and the rotation angle of the driven bottom expanding blade 6B from the maximum expanded state of the bottom expanding blades 6A and 6B shown by the two-dot chain line to the storage state in the bucket shown by the solid line. FIG. 6 is a plan view showing the rotation angle θ1 in comparison with θ2.
Is larger than θ2 (θ1> θ2).

The difference between the rotation angles θ1 and θ2 is determined as follows. That is, when the bottom expanding cylinder 8 is in a fully contracted state, the tip position of the cutter 6c at the lower end of the drive expanding blade 6A and the driven expanding blade 6 are
The tip position of the cutter 6d at the lower end of B is set to a position within the bucket (shaft diameter). As a result, the entire driven expansion blade 6B does not rotate closer to the center of the bucket than the upper end of the drive expansion blade 6A, and the upper end of the driven expansion blade 6B can be prevented from coming into contact with the bucket frame.

In carrying out the present invention, the number of dividing stages of the bottom expanding blade may be two or more, and in any case, the rotation angle θ2 of the bottom expanding blade of the uppermost stage is smaller than that of the bottom expanding blades of the stages lower than the uppermost stage. The configuration. Further, a bottom expanding cylinder may be provided for each of the divided bottom expanding blades, but as in the present embodiment, the bottom expanding cylinder 8 is attached only to the bottom bottom expanding blade, and the upper bottom expanding blade has a rotating power. By transmitting the rotational force by the transmission units 14 and 17, it is not necessary to provide a tuning circuit as in the case of providing the bottom expanding cylinders for the respective bottom expanding blades, and the configuration is simplified.

As shown in the sectional view of FIG. 3 and the side view of FIG. 9A, the first guide plate having an arc-shaped planar shape is provided on the side opposite to the cutter 6c at the tip of the drive expanding blade 6A, that is, on the rear side. 24 is fixed by welding or the like. A second guide plate 25 having an arcuate planar shape is fixed between the first guide plate 24 and the body 9.

As shown in the side view of FIG. 9A and the YY sectional view of FIG. 9B, the first guide plate 24 is formed.
There are groove-shaped guide portions 24h and 24i on the upper and lower sides of the outer surface of the second guide plate 25, and guide portions 25h and 25i that are the upper and lower edges of the second guide plate 25 are movably fitted to these guide portions 24h and 24i. It By providing the cutout portions 24m and 24n at the ends of the groove-shaped guide portions 24h and 24i, the earth and sand accumulated in the groove-shaped guide portions 24h and 24i can be discharged from the cutout portions 24m and 24n, and smooth sliding can be performed. I am able to move.

The projecting guide portion 24j provided at the intermediate portion of the outer surface of the first guide plate 24 is provided with the guide portion 25.
It is configured to smoothly move between the first guide plate 24 and the second guide plate 25 by being slidably sandwiched between i and the intermediate guide portion 25j.

FIG. 10 which is a sectional view taken along line DD of FIG.
As shown in (A) and (B), the first guide plate 24
Between the drive guide blade 25 and the second guide plate 25.
A stopper 24a that abuts the front end of the second guide plate 25 when closing, and stoppers 24b and 25a that abut against each other when the drive expanding blade 6A opens, on the first guide plate 24 and the second guide plate 25, respectively. It is fixedly installed.

Further, as shown in FIGS. 10A and 10B, the limit position of the second guide plate 25 in the opening direction is regulated so that the rear end edge of the second guide plate 25 and the front end edge of the body portion 9 are controlled. In order to prevent a gap from being generated between the second guide plate 25 and the rear end of the second guide plate 25, there is provided a stopper 25b that comes into contact with the stopper 9a at the front end of the body 9 (end of the entrance of the drive expanding blade 6A). It is provided. In addition, EE of FIG.
As shown in FIGS. 10C and 10D which are cross-sectional views and FIGS. 11A and 11B which are FF cross-sectional views of FIG. 9A, the second guide plate 25 is closed. In order to regulate the limit position, a stopper 25c that comes into contact with the stopper 9b at the rear of the body 9 is provided at the front end of the second guide plate 25.

In this structure, when the bottom expanding cylinder 8 is gradually extended and the drive expanding blade 6A is gradually opened to perform bottom expanding excavation while rotating the bucket, the drive expanding blade 6A is housed in the bucket body. When the bottom expanding cylinder 8 is extended from the closed state, the support arm 7A and the drive expanding blade 6A rotate around the rotary shaft 5 and operate in the opening direction. With the movement of the drive expanding blade 6A in the opening direction, the first guide plate 2 provided at the rear portion of the drive expanding blade 6A.
4 and the second guide plate 25 from the inside of the body 9 in FIG.
It moves in the opening direction as shown by the arrow a in (A). Then, the bottom expanding cylinder 8 is extended as it is, and the drive expanding blade 6A is formed as shown in FIG.
When it continues to open as indicated by the arrow b of 0 (B), the stopper 25b at the rear portion of the second guide plate 25 comes into contact with the stopper 9a provided at the front end portion of the body portion 9, and the second guide plate 25 is further moved. Opening stops. This allows the second
A gap is prevented from being generated between the rear end edge of the guide plate 25 and the front end edge of the body portion 9, and the earth and sand introduced into the bucket is prevented from leaking to the outside of the bucket. When the bottom expanding blade 6 is further opened from this state, the first guide plate 24 is
The guide portions 24h, 24i and the projecting guide portion 24j are opened while sliding on the guide portions 25h, 25i, 25j in the upper and lower portions and the middle portion of the second guide plate 25. By the relative movement of the first and second guide plates 24 and 25 in this manner, both can be moved without rattling.

In the case of FIGS. 10A and 10B, the first guide plate 24 and the second guide plate 25 are simultaneously opened in an overlapping state. Depending on the sliding resistance between the first guide plate 2 and the second guide plate 25, as shown in FIGS.
Only 4 may open as shown by arrow c. In this case, the first guide plate 24 has the guide portion 24
At h and 24i, the first guide plate 24 independently opens while sliding on the upper and lower guide portions 25h and 25i of the second guide plate 25. By such an opening operation, as shown in FIG.
As shown in FIG. 0 (D), when the stopper 24b provided at the rear portion of the first guide plate 24 comes into contact with the stopper 25a at the front end portion of the first guide plate 25, the second guide plate 25 also becomes the first guide plate 24. It is pulled by and it opens like the arrow d.

On the other hand, regarding the closing operation of the drive expanding blade 6A, the first guide plates 24 and 25 are interlocked with the initial stage of the closing operation due to the soil resistance in the bucket, as shown in FIG.
In the case of (B), the first guide plate 24 may be closed first, and then the second guide plate 25 may be closed in conjunction.

In the case of FIGS. 11A and 11B, the resistance of the earth and sand in the bucket is small, and when the bottom expanding blade is stored,
That is, during the closing operation, as shown by the arrow e in FIG. 11 (A), the first guide plate 24 and the second guide plate 2
5 closes at the same time in a spread state. By such a closing operation, as shown in FIG. 11B, the stopper 25c on the outer surface of the second guide plate 25 is changed to the stopper 9c of the body portion 9.
When it comes into contact with, the further movement of the second guide plate 25 stops, and then only the first guide plate 24 moves in the closing direction.

In the case of FIGS. 11C and 11D, the resistance of the sediment in the bucket is large. In this case, the resistance of the sediment prevents the movement of the second guide plate 25 in the closing direction by the sediment. Therefore, as shown by the arrow g in FIG. 11C, the stopper 24a of the first guide plate 24 is moved to the second position.
Only the first guide plate 24 moves in the closing direction until it comes into contact with the front edge of the guide plate 25. The stopper 24a of the first guide plate 24 is the second guide plate 2
After abutting against the front edge of No. 5, while the second guide plate 25 is being pushed by the first guide plate 24, as shown by the arrow i in FIG. Move in the closing direction.

Thus, by dividing the guide plate for introducing the earth and sand into the bucket into two, the length of the guide plate in the opening / closing direction can be reduced. Therefore, even if the maximum expanded diameter is increased, the guide plate can be housed in the bucket body, and the expanded expanded diameter can be increased.

In the above embodiment, the guide portions 24h and 24i are provided between the first guide plate 24 and the second guide plate 25. However, the guide portions 24h and 24i are provided between the body portion 9 and the second guide plate 25. May be provided. Also, a plurality of guide plates may be provided between the first guide plate 24 and the body portion 9.

[0049]

According to the first aspect of the present invention, the bottom expanding blades of the bottom expanding bucket for earth drill are divided into a plurality of stages in the height direction, and the respective divided bottom expanding blades are attached so as to be independently rotatable around the rotation axis. , The rotation angle from the maximum diameter expansion state of the topmost bottom expanding blade to the storage state in the bucket is set to be smaller than the rotation angle of the bottom expanding blades of the stages below the topmost expanding blade, so that the topmost expanding blade is expanded. The upper ends of the wings are prevented from contacting the bucket frame. Therefore, the maximum bottom diameter can be increased without changing the bucket diameter when storing the bottom blade.

According to the second aspect, the bottom expanding blades of the bottom expanding bucket for earth drill are divided into upper and lower parts, and the upper and lower expanding blades are independently rotatably mounted around the rotation axis and are connected to the opening / closing device of the bottom expanding bucket. When the drive bottom blade is opened from the closed state, the drive bottom blade starts to open after the drive bottom blade rotates to some extent, so that the drive bottom blade starts to open. Does not rotate more toward the bucket center side than the upper end of the drive bottom expanding blade, and the upper end of the driven bottom expanding blade is prevented from coming into contact with the frame of the bucket. Therefore, the maximum bottom diameter can be increased without changing the bucket diameter when storing the bottom blade.

Further, since the rotary power transmission portion for opening is provided at the position where the driven bottom blade starts rotating later than the drive bottom blade when the bottom blade is opened, the bucket diameter does not have to be increased. Also, the drive expansion blade and the driven expansion blade can be compactly housed in the bucket.

Further, since the driven expansion blades are moved with a time difference to the drive expansion blades via the rotary power transmission section, a tuning circuit is not required when a expansion cylinder is provided for each expansion blade, and the structure is reduced. It will be easy.

According to the third aspect of the present invention, in the first or second aspect, the rotary power transmission section for transmitting the rotation of the driving bottom expanding blade to the driven bottom expanding blade is provided independently for opening and closing the bottom expanding blade. The delay of the driven bottom expanding blades due to the opening and closing of the driving bottom expanding blades can be individually set, which increases the degree of freedom in design.

According to claim 4, in any one of claims 1 to 3, since the axes of the rotating shafts of the divided bottom expanding blades are made to coincide with each other, the bending of the bottom expanding blades and the unevenness of the excavated surface occur. It is possible to eliminate the fear of.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, a guide plate for introducing earth and sand is fixed to the rear portion of the bottom expanding blade at the lowermost stage, and the inner surface of the guide plate and the body portion is fixed. Since another one or a plurality of guide plates for introducing earth and sand are interposed between the and, so as to be relatively movable in the opening and closing direction with respect to the body and the first guide plate,
It is possible to shorten each guide plate, and it is possible to prevent the length of each guide plate in the opening / closing direction from increasing even if the bottom enlargement ratio is increased. Therefore, there is no restriction on the increase of the bottom expansion rate in the sediment introducing section, the bottom expansion rate can be increased, and the taper angle of the inclined surface of the bottom expansion section can be set large.

According to a sixth aspect of the present invention, in any one of the first to fourth aspects, the guide plate is interposed between the first guide plate fixed to the drive expansion blade and the bucket body and the first guide plate. The second guide plate,
Since the stopper is used to regulate the relative movement position between the guide plate and the body, the position where the second guide plate enters the bucket body is regulated, so that the bucket body interferes with the second guide plate. Is prevented. In addition, the length of the guide plate in the opening / closing direction can be shortened to make it compact, the maximum diameter of bottom expansion can be increased, the ratio of bottom expansion can be increased, and the taper angle of the inclined surface of the bottom expansion part can be set large. it can.

According to the seventh aspect, in the fifth or sixth aspect, since the guide portions for restricting the relative movement in the vertical and inward / outward directions between the guide plates or between the body portion and the guide plate are provided, the guide plates are provided. It can be opened and closed without rattling.

According to an eighth aspect of the present invention, in the seventh aspect, the guide portion includes groove-shaped guide portions provided above and below one guide plate, and the groove-shaped guide portion of the other guide plate. Fit the upper and lower guide parts slidably,
Since the earth and sand discharging portion is configured by omitting the end portion of the groove-shaped guide portion, accumulation of earth and sand in the groove-shaped guide portion is prevented, and the guide plate can be slid smoothly.

According to a ninth aspect of the present invention, in the seventh or eighth aspect, a projecting guide portion is provided in the opening / closing direction on a surface of the inner and outer adjacent guide plates facing each other or the guide plate of the body portion. Since the guide portion slidably fitted to the projecting portion is formed on the guide plate or the body portion where the guide portions face each other, there is no rattling in the vertical direction, and the guide plate slides smoothly. be able to.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a bottom expanding bucket according to the present invention.

2 is a rear view showing the embodiment of FIG. 1. FIG.

FIG. 3 is a cross-sectional view showing a state in which the bottom expanding blade is closed in the HH cross section of FIG. 1.

FIG. 4 is a sectional view taken along line CC of FIG.

5 is a view on arrow B of FIG. 2. FIG.

6 is a cross-sectional view taken along the line AA of FIG.

FIG. 7 is a cross-sectional view showing a state in which the bottom expanding blade is opened, taken along the line AA in FIG.

FIG. 8 is a plan view showing the rotation angles of the driven and driven bottom expanding blades from the maximum diameter expanded state to the housed state in the bucket in comparison with each other in the embodiment.

9A is a side view showing a lower portion of the bottom expanding bucket of FIG. 1, and FIG. 9B is a sectional view taken along line YY of FIG.

10A and 10B are cross-sectional views showing an example of the opening operation of the present embodiment, taken along the line D-D in FIG. 9. 9C and 9D are cross-sectional views showing another example of the opening operation of the present embodiment, taken along the line EE in FIG. 9.

11A and 11B are cross-sectional views showing an example of the closing operation of the present embodiment, taken along the line FF in FIG. 9. 10C and 10D are cross-sectional views showing another example of the closing operation of the present embodiment, taken along the line FF in FIG. 9.

[Explanation of symbols]

1: central axis, 2: vertical frame, 3: horizontal frame, 4: bearing, 5: rotary shaft, 6A: drive expansion blade, 6B: driven expansion blade, 6c, 6
d: Cutter, 7A, 7B: Support arm, 8: Bottom expanding cylinder, 9: Body part, 9a, 9b: Stopper, 10: Bucket body, 11: Bottom lid, 12, 13: Protrusion, 14: Turning power transmission part, 15, 16: bracket, 17: rotation power transmission part,
20: main scraper, 20a: auxiliary scraper, 21:
Link, 24: First guide plate, 24a, 24b:
Stoppers, 24h, 24i: Groove-shaped guide portions, 24j:
Protruding guide part, 24m, 24n: cutout part, 25: second
Guide plate, 25a to 25c: stopper, 25h,
25i: guide part, 25j: projecting guide part

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) E21B 11/00 E21B 10/32

Claims (9)

(57) [Claims] 1. A bottom expanding blade of a bottom expanding bucket for an earth drill is divided into a plurality of stages in the height direction, and each of the divided bottom expanding blades is attached so as to be independently rotatable around a rotation axis. A bottom expanding bucket, wherein a rotation angle from a maximum diameter expanding state to a storage state in a bucket is set to be smaller than the rotation angle of a bottom expanding blade in a stage lower than an uppermost bottom expanding blade. 2. A bottom expanding blade of a bottom expanding bucket for an earth drill is divided into upper and lower parts, and upper and lower expanding blades are independently rotatably mounted around a rotation axis, and drive bottom expanding blades connected to an opening / closing device for the bottom expanding blade are provided. The lower side and the driven bottom expanding blade are on the upper side, and when the bottom expanding blade is opened, a rotary power transmission part for opening is provided at a position where the driven bottom expanding blade starts rotating later than the drive bottom expanding blade. Expanded bottom bucket. 3. A bottom expanding bucket according to claim 2, wherein a rotational force transmitting portion for transmitting the rotation of the driving bottom expanding blade to the driven bottom expanding blade is provided independently for opening and closing the bottom expanding blade. 4. A bottom expanding bucket according to any one of claims 1 to 3, wherein the axis of the rotating shaft of each of the divided bottom expanding blades is made to coincide with each other. 5. The guide plate for introducing earth and sand according to claim 1, wherein a guide plate for introducing earth and sand is fixed to the rear side of the bottom expanding blade at the lowest stage, and between the guide plate and the inner surface of the body, A bottom expanding bucket characterized in that another one or more guide plates for introducing earth and sand are interposed so as to be relatively movable in the opening / closing direction. 6. The first guide plate for introducing earth and sand according to claim 1, wherein a first guide plate for introducing sand is fixed to the rear side of the bottom expanding blade at the lowermost stage, and the inner surface of the first guide plate and the body is A second guide plate for introducing earth and sand is interposed between the body and the first guide plate so as to be relatively movable in the opening / closing direction, and an opening direction between the first guide plate and the second guide plate is provided. , A stopper for limiting the relative movement limit position in the closing direction is provided, and a gap is formed between the rear portion of the second guide plate and the body portion and between the front edge of the body portion and the second guide plate. And a stopper for preventing the contact between the second guide plate and the body portion.
A bottom expanding bucket characterized by having a stopper for restricting the limit position of the guide plate in the closing direction. 7. The guide part according to claim 5 or 6, wherein a guide part is provided between the guide plates adjacent to the inside and the outside, or between the body part and the guide plate, for restricting relative movement in the vertical and inward and outward directions. A characteristic bottom expanding bucket. 8. The guide unit according to claim 7, wherein the guide unit comprises a groove-shaped guide unit provided above and below one guide plate, and the groove-shaped guide unit serves as a guide unit above and below the other guide plate. A bottom expanding bucket characterized in that it is slidably fitted and the end portion of the groove-shaped guide portion is removed to form a sediment discharge portion. 9. The projecting guide portion according to claim 7 or 8, wherein a projecting guide portion is provided in an opening / closing direction on a surface of the guide plate adjacent to the inside / outside or a guide plate of the body portion facing each other. A bottom expanding bucket characterized in that a guide portion slidably fitted to the projecting guide portion is formed on the guide plate or the body portion.