JP7111356B2 - Drilling rigs and rotary excavators - Google Patents

Description

The present invention relates to drilling rigs and rotary drilling machines. More specifically, the impact force is improved compared to a conventional drilling device (hereinafter referred to as "conventional device"), and the drilling device breaks in a hole drilled during drilling work (hereinafter referred to as "drilled hole"). It relates to a device capable of suppressing an accident in which a part remains in an excavated hole (hereinafter referred to as "fracture residual accident").

In recent years, especially in construction work in urban areas, vibration and noise generated during excavation work accompanying foundation pile driving, etc. have become a problem. proposes a rotary excavator described in . The excavator of this rotary excavator is shown as an excavator 9 in FIG.

The excavator 9 performs excavation work (hereinafter referred to as "rotary excavation work") by being imparted with rotational motion by a rotary drive device (not shown). and has a plurality of bits consisting of a bit arranged at the center of rotation (hereinafter referred to as "central bit 91") and bits arranged around this central bit (hereinafter referred to as "peripheral bit 92"). , each bit is configured to be impact-driven with a time lag from each other. Compared to conventional down-the-hole hammers that hit the ground by moving a single bit of approximately the same diameter as the drilled hole, this makes the bit hitting cycle faster, instead of the bit hitting once. By reducing the impact on the ground caused by each impact, it is possible to perform excavation work with low vibration and low noise.

JP 2007-92447 A

By the way, when the inventors of the present invention operated a rotary excavator using the excavator 9, it was found that the excavator 9 sometimes strikes the central bit 91 and the peripheral bit 92 at the same time. There was found. Even if such simultaneous impacts occur, excavation work can be performed with less vibration and noise than the conventional down-the-hole hammer. Prototype 93, which is an improved version of 9, was produced.

A prototype machine 93 shown in FIG. 12(a) does not have a central bit on the excavating surface, and has corners 933 formed by expanding the striking surface 931 of the peripheral bits in the direction of the rotation axis of the prototype machine 93. The tip angles of the corners 933 of the bit are located at the rotation axis 9R, and the corners 933 are arranged so as to face each other (a peripheral bit having such a configuration is hereinafter referred to as "excavation bit 930"). In general, a plurality of chips made of cemented carbide are implanted on the striking surface of the drilling bit to form convex portions with respect to the striking surface. The excavation bit 930 of the trial machine is similarly configured to have a tip 934 implanted therein.

When the inventors of the present invention operated a rotary excavator using the prototype machine 93, it was found that the prototype machine 93 had a first problem related to impact force and a second problem related to a fracture residual accident. There was found.

The first problem is that when the inventors of the present invention perform excavation work using the prototype machine 93, the excavation work of the ground that is predicted to consist of a soft layer (hereinafter referred to as "soft layer") composed of earth, sand, soft rock, etc. It turned out when I hit an unexpected hard rock.

The prototype machine 93 enables excavation work with low vibration and low noise by reducing the impact on the ground caused by each impact of the excavation bit 930. , the hard rock cannot be crushed due to insufficient striking power, or it takes time to crush the hard rock, or the excavation direction deviates along the slope of the hard rock because it cannot be crushed ( hereinafter referred to as "obstacles such as inability to crush hard rock due to insufficient striking power").

In such a case, it is possible to remove the prototype machine 93 once, replace it with a single bit type down-the-hole hammer with a large impact force, replace it again with the prototype machine 93 after crushing the hard rock, and restart the excavation work. , it took extra time and effort. During the work with the single bit type down-the-hole hammer, large vibration and noise were generated.

The second problem was discovered when the prototype machine 93 was similarly used for excavation work, and an accident occurred in which the prototype machine 93 was broken in the excavated hole and the tip remained in the excavated hole.

The prototype machine 93 has a structure in which the joint portion between the device main body and the object to be welded (for example, an air tank) is flat and connected in the longitudinal direction by connecting bolts. When it rotates inside, it is resisted by the earth pressure, and a shear load is applied in the longitudinal direction of the prototype 93, so that a large shear force is applied to the connection bolt.

If this state continues, the connecting bolt may break, and when the connecting bolt is broken, when the prototype machine 93 is pulled up from the excavated hole, the tip of the prototype machine 93 will remain (left behind) in the excavated hole rather than the broken part. In order to continue the excavation work, it is necessary to lift the remaining part, but the remaining part is also quite heavy and is in a state that it is contained in a narrow hole, so the labor, time, and cost required for the lifting work will be burdened. was big. It should be noted that there is a possibility that a similar accident may occur in the excavator 9 as well.

The present invention has been devised in view of the above points, and provides an excavating apparatus that has improved striking force compared to conventional apparatuses and that can suppress fracture and residual accidents that occur in an excavated hole during excavation work, and , the purpose of which is to provide a rotary excavator.

In order to achieve the above object, the excavator of the present invention is a columnar body rotatable in the axial direction around the rotation axis, and has a drive unit storage part around the rotation axis parallel to the rotation axis. It has a plurality of drive units that are individually stored in the body and the drive unit storage, and that can supply driving force using air as a power source. A first joint portion is formed on one end face of the body portion, an air introduction hole communicating with the drive unit storage portion is formed on the same end face, and a second joint portion is formed on the other end face of the body portion. an apparatus main body, an air introduction section that is attached to rotate together with the apparatus main body and that can introduce air from outside the apparatus, and a first joint section that is joined to the first joint section with a fitting structure and is in a fitted state. an air tank formed with a third joint including a detachment restraint structure for restraining the detachment of the air tank; and a fourth joint attached to rotate together with the apparatus body and joined to the second joint. A chuck guide in which a plurality of through-holes are formed so as to communicate with the storage portion, a connection shaft portion to be attached to the chuck guide, and a head portion including a striking surface provided at the tip of the connection shaft portion. each of which receives a driving force from a drive unit through a connecting shaft portion inserted into each guide hole and moves forward and backward in the axial direction; An air distribution part capable of distributing air to be supplied to the drive unit is provided so that all move forward and backward at different timings.

Here, the drilling apparatus of the present invention has the following effects by including the apparatus main body having the aforementioned drive unit, body, first joint and second joint.

The body can store a plurality of drive units for each of the plurality of drive unit storages formed therein. The drive units can each supply a driving force to a plurality of drilling bits to move the corresponding drilling bits back and forth. Also, the air introduction hole can introduce air, which is the power source of the drive unit, from the air tank into the drive unit storage section.

Further, since the drive unit storage section is provided parallel to the rotation axis, the drive force from the drive unit is transmitted linearly to the excavation bit, and the loss of power transmission can be reduced. In addition, since the drive unit storage section is provided around the rotation axis, when rotary motion is applied to the entire drilling rig using a rotary table or the like, vibration due to shaft shake or vibration due to shaft shake may occur. Unnecessary expansion of the drilled hole can be suppressed.

Furthermore, unlike the conventional device, the body is not a hollow cylinder, but a substantially solid column except for the drive unit storage section. As a result, the striking force against an object to be excavated such as the ground to be excavated (hereinafter referred to as "object to be excavated") is improved. In addition, due to the substantially solid structure, the rigidity is higher than that of the conventional device, and breakage due to the body is less likely to occur, so that the service life can be extended.

In addition, "substantially solid structure except for the drive unit storage part" means that the drive unit storage part and the liquid flow path, etc. are formed in addition to the drive unit storage part. It means an embodiment in which the portion to be removed has a solid structure, and is used in the sense of including a solid structure.

The first joint portion can be joined to the third joint portion with a fitting structure to join the apparatus main body and the air tank. Further, the second joint portion can be joined to the fourth joint portion to attach the chuck guide to the apparatus main body, thereby joining the apparatus main body and the chuck guide.

In the drilling apparatus of the present invention, since the air tank has the air introduction portion, it can be connected to an external device such as a compressor through the air introduction portion to introduce air. Moreover, the air tank can be attached so as to rotate together with the apparatus main body by having the third joint portion.

Furthermore, the third joint is joined to the first joint by a fitting structure, so that the joint between the air tank and the device body is integrated and reinforced by the fitting structure, thereby improving the shear strength. , it is possible to reduce the possibility of occurrence of a fracture residual accident in the above-mentioned excavated hole due to the connection point seen in the conventional device. In addition, the detachment restraint structure can restrain detachment (disengagement) of the joined air tank and apparatus main body.

In the drilling apparatus of the present invention, since the chuck guide has the guide holes, a drilling bit can be attached to each guide hole. Since each guide hole is a through hole that communicates with the drive unit storage portion, the connection shaft portion of the drilling bit can be inserted so as to move forward and backward in the axial direction, and the drive unit stored therein can be inserted. can be transmitted to the drill bit. Moreover, the chuck guide can be attached so as to rotate together with the apparatus main body by having the fourth joint portion.

In the drilling apparatus of the present invention, the connecting shaft portion inserted into the chuck guide advances and retreats along the guide hole, and the drilling bit as a whole including the head portion also advances and retreats accordingly. hits the object to be excavated ahead of the excavator to excavate the object to be excavated.

The chuck guide described above is arranged such that each guide hole communicates with the drive unit storage section, and each drive unit storage section is formed around the rotation axis. are arranged around the rotation axis of the chuck guide. Therefore, by performing the excavation work while rotating the excavator, the object to be excavated that is hit by each excavation bit can be excavated evenly.

The air distribution section can distribute the air supplied to the drive unit so that the drilling bits strike at different timings, whereby the drilling bits alternately strike the object to be excavated, Since it is difficult for the drilling bits to hit the object to be drilled at the same time, the drilling work can be performed with less vibration and less noise than a conventional down-the-hole hammer.

It should be noted that "some or all of the drilling bits have different timings" means that all the drilling bits advance and retreat at different timings, and that some of the drilling bits advance and retreat at different timings. It is used in the sense of including both.

The arrangement of the air distribution section is not particularly limited. It fits well and is unlikely to be damaged by an external force, so it is more preferable from the standpoint of maintenance.

Also, a first arrangement mode in which the striking surfaces of each drilling bit are arranged around the rotation axis of the chuck guide and only one of the striking surfaces is arranged to overlap the rotation axis, or the striking surface A corner is formed on the side of the rotation axis, and only the edge on the side of the rotation axis of a pair of striking surfaces arranged opposite to each other across the rotation axis overlaps the rotation axis, and the tip of the corner is are arranged so as not to overlap with the rotation axis, and the edges of the striking surfaces on the rotation axis side are assembled so as to be close to each other near the rotation axis. In some cases, each drilling bit may be mounted with little clearance between and near the axis of rotation.

According to this arrangement configuration of the drilling bits, even if the drilling bits arranged in the center of the drilling surface in the conventional device are eliminated, the drilling bits can uniformly drill the object to be drilled, especially hard rock. During excavation, it is possible to make the bottom of the excavated hole substantially flat without forming a convex undigged portion (hereinafter referred to as "central convex portion") at the center of the deep side of the excavated hole.

The central protrusion will be described in detail with reference to FIG. 12 . The present inventor further improved the excavator 9 and created a prototype 93 (see FIG. 12(a)) having the above-described configuration. When the inventor of the present invention performed excavation work using the prototype 93, he accidentally hit a hard rock in the ground. was formed (see FIG. 12(c)).

In addition, the vicinity of the corner portion 933 of each excavation bit 930 was worn away, and the striking surface 931 itself also had a central deformed portion H7 in a depressed state (see FIG. 12(b)). At a later date, when the excavation work on the hard rock was tried again, the formation of the central convex portion H6 and the occurrence of the central deformed portion H7 of the prototype 93 were again confirmed.

Although the reasons for the formation of the central convex portion H6 and the occurrence of the central deformed portion H7 are not necessarily clear, it is presumed that they are due to the following reasons.
(a) During the operation of the prototype machine 93, each of the excavation bits 930 arranged at the excavation side end of the excavation device 9 individually moves forward and backward at different timings. In other words, the drilling bits 930 in the retracted state and the advanced state are mixed, and as a result, the loads (shaft load due to self-weight, impact load due to impact) applied to each drilling bit 930 are not evenly distributed, but are distributed in the advanced state. will concentrate on the drilling bit 930 of
(b) In addition, the edge of the striking surface 931 of the drilling bit 930 in the advanced state, or a portion close to the edge, is more likely to be worn away than other flat portions. the weaker the strength. In addition, since the corners and their vicinity are tapered and have a narrower area than the other portions, if the tips 934 are arranged at the same density as the other portions, the number of implantable tips 934 is reduced.
(c) As described above, the load concentrates on the drilling bit 930 in the advanced state, and furthermore, the load tends to concentrate on the corner 933 of the drilling bit 930 in the advanced state. A smaller number of the tips 934 that are formed are subjected to a greater load than the rest of the tips, which causes the tips 934 to wear out or break, such as the tips 934 falling off, at an earlier stage than the rest of the parts.
(d) The breakage of the tip 934 significantly reduced the excavation force near the corner 933 , causing a difference in excavation force from the other portions of the striking surface 931 , and directly In the excavating state, the corner portion 933 and its vicinity are worn or plastically deformed together with the base portion, further reducing the excavating force.
(e) As a result, due to the difference in excavation force between the vicinity of the rotation axis 9R and other portions of the striking surface 931, the central convex portion H6 of the hole bottom surface H3 of the excavated hole H1 has a shape in which the central portion swells more than the outer periphery. is formed and
(f) Further, the end of the excavated object side of the prototype machine 93 during excavation work is subjected to a strong pressing force due to the weight of the machine itself or the load from the outside of the machine. On the other hand, it is considered that the prototype machine 93 continued to rotate while the hitting surface 931 near the corner 933 mentioned above was in contact, causing plastic deformation or uneven wear, and the central deformation part H7 was generated on the hitting surface 931. .

However, according to the drilling apparatus of the present invention, each drilling bit is arranged such that the edge of each striking surface on the side of the rotation axis is aligned with the rotation axis of the chuck guide in either the first arrangement mode or the second arrangement mode. Because of the configuration in which the rocks are gathered in the vicinity of the , it is possible to excavate even hard rock, and it is possible to suppress the formation of a central protrusion at the center of the deep side of the excavated hole. It is possible to suppress the occurrence of a central deformed portion (that is, deformation and uneven wear of the drilling bit) caused by the formation of the convex portion.

That is, when each drilling bit is configured in the first arrangement mode, only one of the striking surfaces is arranged so as to overlap the rotation axis of the chuck guide (hereinafter referred to as "rotational axis overlapping arrangement"). The striking surface can always overlap the rotation axis and its vicinity. According to this rotation axis overlapping arrangement, during rotary excavation work, excavation is performed in a state in which a portion of the striking surface reliably overlaps and passes through the rotation axis of the chuck guide and its vicinity at all times. The center of the hole can be excavated at all times, and the concentration of load on the corner is alleviated. As a result, even when excavating hard rock, the formation of the central convex portion is suppressed, and accordingly the occurrence of the central deformed portion is also suppressed.

When each drilling bit is configured in the second arrangement mode, a corner portion is formed on the striking surface on the side of the rotation axis of the chuck guide, and a pair of striking surfaces arranged opposite to each other with the rotation axis interposed therebetween. Only the edge on the side of the rotation axis overlaps the rotation axis, and the tip of the corner is arranged so as not to overlap the rotation axis. An arrangement that does not overlap with the center (hereinafter referred to as "non-overlapping arrangement of the rotation axis on the striking surface"), and the long edge instead of the tip of the corner is intermittently or substantially continuous between the rotation axis and its vicinity. can pass through. As a result, the center of the surface to be excavated is excavated by the edge of the chuck guide on the rotation axis side of the set of striking surfaces opposed to each other and the striking surfaces along the edges, and the striking surfaces are concentrated. The load can be distributed over a plurality of (at least two) striking surfaces, and the concentration of the load on the corners can be alleviated. Along with this, the occurrence of the central deformed portion is also suppressed.

Further, the driving unit may be a drilling bit whose striking surface overlaps with the rotation axis in the first arrangement mode, or whose striking surface overlaps only the rotation axis side edge in the second arrangement mode. If it is set so as to apply the maximum impact force among the plurality of drilling bits to any one of the drilling bits that are overlapped, the drilling bits that are overlapped around the rotation axis Striking power is especially enhanced.

With the above settings, the impact force imparted by all excavation bits is not uniform, and the impact force can be differentiated. The drilling bit crushes hard rock, or the first blow causes it to crack and the subsequent blows of other drilling bits break it into small pieces (these effects are hereinafter referred to as "breaking hard rock, etc."). By doing so, it is possible to further enhance the effects of suppressing the formation of a central protrusion and suppressing the occurrence of a central deformed portion during excavation of hard rock.

By the way, in order to improve the impact force of all drilling bits, it is necessary to take measures such as increasing the size of each part (piston, etc.) of the drive unit. However, since the present invention is configured to improve the striking force of at least one of the drilling bits, the size of the entire device is increased and the air consumption of the drive unit is increased. can be minimized.

In addition, as described above, conventional devices such as the drilling device 9 may cause problems such as inability to crush hard rocks due to insufficient striking power when hitting unexpected hard rocks, but the drilling device of the present invention Since hard rock can be dealt with by each drilling bit set in one of the above-mentioned modes, it is possible to deal with both soft layers and hard rock without replacing the equipment. It is possible to omit unnecessary labor and time due to the replacement of .

In addition, when each drilling bit is formed with a ridge striking portion projecting from the striking surface toward the object to be excavated along the outer peripheral edge of the drilling bit when viewed in the direction of the rotation axis of the chuck guide. can apply the initial impact to the excavated object with the ridge striking part that concentrates the load along the ridge, so that the striking power is further improved than that of striking with a flat striking surface. Even if the object to be excavated is hard rock in an excavation hole, the hard rock can be crushed by this impact.

The striking surface of each excavating bit described above is not limited to a single flat surface. A mode such as one including a surface may be used. In addition, the drilling bit having the ridge striking portion is at least one or more of the respective drilling bits, and naturally includes a mode in which all the drilling bits are formed with the ridge striking portion. Each drilling bit may have a drilling portion on its side surface (for example, a portion for drilling the inner wall of the hole), but the drilling portion on the side does not correspond to the striking surface described above.

In addition, the first joint portion is configured by a substantially cylindrical convex portion having a smaller diameter than the outer diameter of the middle portion in the longitudinal direction of the body, and a male screw is provided on the side surface of the convex portion. 3. If the joint is an opening with an inner diameter that fits the first joint and has a structure in which a female screw is provided on the inner surface near the opening, a simple structure consisting of a male screw and a female screw, which is a detachment prevention structure, can be used. Although it has a simple structure, the air tank and the main body of the device can be firmly joined, and workability during assembly and disassembly is also good.

Further, since the structure does not require connection bolts for joining the air tank and the apparatus main body, there is no possibility of the above-described accident of remaining fracture caused by the connection bolts. In addition, since the structure is such that the first joint portion of the device main body is fitted and screwed into the third joint portion of the air tank, the first joint portion enters the third joint portion without any gap and is integrated, and stress is applied to the entire fitting portion. can be dispersed (in other words, stress concentration at a specific location can be suppressed), and the possibility of a fracture residual accident occurring can be reduced.

In addition, the second joint portion is formed by cutting out a disk-shaped convex portion having a smaller diameter than the outer diameter of the middle portion in the longitudinal direction of the body portion, along the extending direction of the guide hole. , when the fourth joint portion is formed in a recessed shape in which the second joint portion is just accommodated in the end face of the chuck guide in the apparatus main body direction, the second joint portion of the apparatus main body and the fourth joint portion of the chuck guide are , can be joined with a fitting structure by unevenness.

According to this fitting structure, the second joint enters and integrates with the fourth joint, and stress is dispersed over the entire fitting portion against external force applied in a direction intersecting the longitudinal direction of the excavator (in other words, Then, it is possible to suppress the concentration of stress on a specific portion), and the possibility of occurrence of a fracture residual accident can be reduced. Further, since the convex portion of the second joint portion is notched in the concave curved surface along the extension direction of the guide hole, it does not hinder the advancing and retreating movement of the excavating bit.

In addition, if the contact surface where the second joint portion and the fourth joint portion abut against each other is provided with an anti-rotation structure, the second joint portion and the fourth joint portion will not come into contact with each other during the operation of rotating the excavator. Mutual slipping rotations at the tangent surfaces can be prevented. As a result, the rigidity against shearing stress generated at the seam between the device main body and the chuck guide can be improved, and the possibility of residual fracture accidents occurring between the device main body and the chuck guide can be reduced.

In order to achieve the above object, the rotary excavator of the present invention is a columnar body rotatable in the axial direction around the rotation axis, and a drive unit arranged around the rotation axis in parallel with the same rotation axis. A plurality of storage sections are formed, and the portions other than the drive unit storage section are substantially solid. Including a drive unit, a first joint is formed on one end face of the body, an air introduction hole communicating with the drive unit storage part is formed on the same end face, and a second joint is formed on the other end face of the body. is formed, an air introduction section that is attached to rotate together with the apparatus body and can introduce air from outside the machine, and a first joint that is joined with a fitting structure and is in a fitted state An air tank in which a third joint including a detachment suppression structure for suppressing detachment of the joint is formed, and a fourth joint is formed so as to rotate together with the apparatus body, and is joined to the second joint. A chuck guide having a plurality of through-holes that communicate with the unit storage section, a connection shaft that is attached to the chuck guide, and a head section that includes a striking surface provided at the tip of the connection shaft. a plurality of excavation bits each moving forward and backward in the axial direction by receiving a driving force from a drive unit through a connecting shaft portion inserted into each guide hole; An excavator having an air distribution section capable of distributing air supplied to a drive unit so as to move forward and backward with a drive unit;

Here, the rotary excavator of the present invention is provided with the above-described excavator having the apparatus main body, air tank, chuck guide, excavation bit, and air distribution section, and a rotary drive device, thereby exhibiting the following effects. .

Since the excavator of the present invention has the body portion, it is possible to store a plurality of drive units in each of the plurality of drive unit storage portions. The drive units can each supply a driving force to a plurality of drilling bits to move the corresponding drilling bits back and forth. Also, the air introduction hole can introduce air, which is the power source of the drive unit, from the air tank into the drive unit storage section.

Further, since the drive unit storage section is provided parallel to the rotation axis, the drive force from the drive unit is transmitted linearly to the excavation bit, and the loss of power transmission can be reduced. In addition, since the drive unit storage section is provided around the rotation axis, when rotary motion is applied to the entire drilling rig using a rotary table or the like, vibration due to shaft shake or vibration due to shaft shake may occur. Unnecessary expansion of the drilled hole can be suppressed.

Furthermore, unlike the conventional device, the body is not a hollow cylinder, but a substantially solid column except for the drive unit storage section. , the impact force against the excavated object is improved. In addition, due to the substantially solid structure, the rigidity is higher than that of the conventional device, and breakage due to the body is less likely to occur, so that the service life can be extended.

The first joint portion can be joined to the third joint portion with a fitting structure to join the apparatus main body and the air tank. Further, the second joint portion can be joined to the fourth joint portion to attach the chuck guide to the apparatus main body, thereby joining the apparatus main body and the chuck guide.

Since the air tank has the air introduction portion, the excavator can be connected to an external device such as a compressor through the air introduction portion to introduce air. Moreover, the air tank can be attached so as to rotate together with the apparatus main body by having the third joint portion.

Furthermore, the third joint is joined to the first joint by a fitting structure, so that the joint between the air tank and the device body is integrated and reinforced by the fitting structure, thereby improving the shear strength. , it is possible to reduce the possibility of occurrence of a fracture residual accident in the above-mentioned excavated hole due to the connection point seen in the conventional device. In addition, the detachment restraint structure can restrain detachment (disengagement) of the joined air tank and apparatus main body.

Since the chuck guide has guide holes, the drilling apparatus can attach a drilling bit to each guide hole. Since each guide hole is a through hole that communicates with the drive unit storage portion, the connection shaft portion of the drilling bit can be inserted so as to move forward and backward in the axial direction, and the drive unit stored therein can be inserted. can be transmitted to the drill bit. Moreover, the chuck guide can be attached so as to rotate together with the apparatus main body by having the fourth joint portion.

In the drilling rig, the connecting shaft portion inserted into the chuck guide advances and retreats along the guide hole, and the entire drilling bit including the head portion also advances and retreats accordingly. It is possible to excavate the object to be excavated by hitting the object to be excavated at the tip of the . Further, each drilling bit attached to the chuck guide is arranged around the rotation axis of the chuck guide. Therefore, by performing the excavation work while rotating the excavator, the object to be excavated that is hit by each excavation bit can be excavated evenly.

Since the drilling apparatus has the air distribution section, it is possible to distribute the air supplied to the drive unit so that the impact timings of the drilling bits are different. Since the drill bit hits the object to be excavated at the same time, it is difficult for the drill bits to strike the object at the same time, so that the excavation work can be performed with less vibration and less noise than a conventional down-the-hole hammer.

Furthermore, since the rotary excavator of the present invention is provided with the above-described rotary drive device, it is possible to rotate the drilling device in combination with the rotary drive device. An excavation method can be carried out by applying an impact force to an object.

According to the excavator and the rotary excavator of the present invention, the impact force can be improved as compared with the conventional equipment, and it is possible to suppress the fracture and residual accident that occurs in the excavated hole during the excavation work.

It is a front view which shows the rotary excavator of this invention. 1. It is sectional view explanatory drawing which disassembles and shows the excavator (1st Embodiment) shown in FIG. 1 for every component. FIG. 3 is an explanatory view showing a joining structure between the air tank and the apparatus main body shown in FIG. 2; FIG. 2 is an explanatory cross-sectional view of the excavator shown in FIG. 1 ; Fig. 2 shows the arrangement of the striking surfaces of the drilling bit of the drilling rig, where (a) is a bottom view of the first embodiment, and (b) is a bottom view of another mode (modification 1) of the drilling bit shown in (a). is. Fig. 2 shows the arrangement of the striking surface of the drilling bit of the drilling rig (second embodiment), (a) is a bottom view of the second embodiment, and (b) is another aspect (deformation) of the drilling bit shown in (a). It is a bottom view of example 2). Fig. 12 shows the arrangement of the striking surface of the drilling bit of the drilling rig (third embodiment), (a) is a bottom view of the third embodiment, and (b) is another aspect (deformation) of the drilling bit shown in (a). FIG. 8C is a bottom view of Example 3), and FIG. 8C is a bottom view of another embodiment (Modification 4) of the excavating bit shown in FIG. Fig. 10 shows a drilling bit of a drilling rig (fourth embodiment), (a) is a side view, (b) is a bottom view showing the arrangement of the striking surface of the drilling bit, and (c) is a drilling bit shown in (a). It is a bottom view of another aspect (modification 5) of. FIG. 10 is an explanatory cross-sectional view showing an excavating device (fifth embodiment) and showing an enlarged joint structure between the device main body and the chuck guide. FIG. 10 is an explanatory diagram showing, from a perspective direction, a joint structure between the apparatus main body and the chuck guide shown in FIG. 9; It is a perspective view which shows the excavator of patent document 1 description. (a) is a perspective view showing the prototype of the excavator before the present invention, (b) is an explanatory diagram comparing the excavation bit before and after the excavation work of the prototype shown in (a), and (c) is shown in (a). It is explanatory drawing which shows the inside of the excavation hole excavated by the prototype machine shown.

Embodiments of the present invention will be described in further detail with reference to FIGS. 1 to 10. FIG. The following description will be given in the order of [first embodiment] to [fifth embodiment]. In addition, the reference numerals in each figure of the drawings are attached within the scope of reducing complexity and facilitating understanding. .

A rotary excavator 1 shown in FIG. Each part is described in detail below.

[First Embodiment]
(drilling equipment)
See Figures 1-5. The drilling device 2 includes an air tank 21 , a device main body 22 , a chuck guide 25 , a plurality of drilling bits 26 and an air distributor 27 .

(air tank)
The air tank 21 is joined to one end side of the device main body 22, and is arranged so as to be the upper part of the drilling rig 2 in FIG. Figure 1-4).

The air tank 21 temporarily stores high-pressure air introduced from an air supply source such as an external compressor (not shown) and supplies it to the apparatus main body 22. shaped tank body 210, an air introduction part 211 provided on the lid on one end side (upper side in FIG. 2 etc.) of the tank body 210, provided on the other end side (lower side in FIG. 2 etc.) of the tank body 210 It has a structure having a third joint portion 212 provided on the tank body portion 210 and a spiral blade 213 provided on the side surface of the tank body portion 210 .

In this embodiment, the air tank 21 has a structure in which a detachable cylindrical attachment (reference numerals omitted) is fitted onto the outside, and the spiral blade 213 appearing on the side surface of the air tank 21 in FIG. 1 etc. is provided on the attachment. However, it is not limited to this. For example, instead of the spiral blade 213, a flat bar or the like extending in the longitudinal direction of the device may be provided, or the spiral blade may be directly attached to the surface of the air tank 3 without using an attachment. It may be provided.

Since the tank body 210 has a smaller diameter than the device body 22, the maximum diameter portion 21M of the tank body 210 and the maximum diameter portion 22M of the device body 22 are the same or the tank body 210 has a slightly larger diameter. (hereinafter referred to as “substantially the same”) (see FIG. 4, etc.). The soil is lifted up via the spiral blades and discharged without increasing the hole diameter of the hole H1. The tank body 30 has an airtight structure, and can temporarily store air supplied from the outside in a high pressure state.

The air introduction part 211 is a hexagonal prism-shaped connecting joint whose rotational axis coincides with the rotational axis of the air tank 21 , and the base end is attached to the air tank 21 . The air introduction portion 211 is formed with an opening 214 having a free end, and a flow path 215 communicating from the opening 214 to the inside of the air tank 21 is formed (see FIG. 4). The air introduction portion 211 rotatably connects the air tank 21 and a suspension shaft 34 to be described later. Air is supplied to (see FIGS. 1 and 4).

The third joint portion 212 is an opening having an inner diameter that accommodates a first joint portion 222, which will be described later, and has a structure in which a female screw 216 is provided on the inner surface near the opening (see FIG. 3B). As a result, the first joint portion 222 is fitted inside the third joint portion 212, and the female screw 216 and the male screw 225 provided on the side surface of the first joint portion 222, which will be described later, are screwed together. can.

(device body)
The apparatus main body 22 has a structure having four drive units 220 and a trunk section 221 that houses each drive unit 220 . The trunk portion 221 is provided with a first joint portion 222 on one end face (upper end face in FIG. 2 etc.) and a second joint portion 223 on the other end face (lower end face in FIG. 2 etc.). .

A drive unit housing portion 224 is provided in the body portion 221 . The drive unit storage sections 224 are through holes arranged parallel to the rotation axis around the rotation axis of the apparatus main body 22. A total of four drive unit storage sections 224 are provided at equal intervals, and the drive unit 220 fitted therein is exactly inserted. It is made large enough to fit. 2 etc., the drive unit 220 can be fitted into the drive unit storage part 224 from the opening in the lower end face in FIG. The area is gradually narrowed, and the tip portion opens into the tank body portion 210 of the air tank 21 to form an air introduction hole 226 through which air can be introduced.

Since the drive unit storage part 224 is provided parallel to the rotation axis, the drive force from the drive unit 220 is transmitted linearly to the excavation bit 26, and the loss of power transmission is small. In addition, since the drive unit storage section 224 is provided around the rotation axis and in parallel with the rotation axis, when the rotation drive device 3 is used to apply a rotary motion to the entire excavator 2, the shaft blurring occurs. Vibration caused by the shaft and unnecessary expansion of the drilled hole due to shaft vibration are suppressed.

The body portion 221 is a cylindrical body made of metal, and the portion other than the drive unit storage portion 224 has a substantially solid structure (see FIGS. 2 and 4). By adopting this structure, the excavator 2 has a larger weight (approximately twice the weight of the conventional device) compared to the conventional device (the body is a hollow cylinder) even though the volume is the same. It has improved striking power against excavated objects. In addition, since the trunk portion 221 has a substantially solid structure, it has high rigidity and is hardly deformed by an external force, so that the service life can be extended.

Furthermore, a surface material (not shown) made of a high-strength steel plate is attached to the surface of the body portion 221 . By having this surface material, the body part 221 itself is treated so as not to be worn, and when the surface material is worn or damaged, the surface material can be replaced or repaired to recover the wear resistance. be able to.

The first joint portion 222 is provided on one end surface of the body portion (the upper end of the body portion 22 in FIG. 2 and the like), and has a shape that fits with the third joint portion 212. The third joint portion in a joined state. It is a structure including a detachment suppression structure that suppresses the detachment of 212 . The first joint portion 222 can be fitted with the third joint portion 212 with a fitting structure, that is, the air tank 21 and the apparatus main body 22 can be connected.

In this embodiment, the first joint portion 222 is a substantially cylindrical convex portion having an outer diameter that is smaller than the outer diameter of the middle portion in the longitudinal direction of the trunk portion 22 and that fits exactly in the opening of the third joint portion 212. , and a male screw 225 (a paired part of the detachment restraint structure) is provided on the side surface. Thereby, the first joint portion 222 can be fitted into the third joint portion 212 and screwed with the female thread 216 and the male thread 225 . The height from the base end to the upper end of the first joint portion 222 is set to about 20 cm.

As a result, it is suppressed that the air tank 21 and the device main body 22 that are connected to each other due to screwing of the female screw 216 and the male screw 225 are prevented from coming off (separating). In addition, compared with the conventional device, the structure does not require connection bolts for joining the air tank 21 and the device main body 22, so the possibility of occurrence of fracture residual accidents in the excavated hole is reduced. Moreover, since the fitting structure is a simple structure, workability during assembly and disassembly is good.

Furthermore, according to this fitting structure, the first joint portion 222 enters the third joint portion 212 without gaps and is integrated, thereby dispersing the stress in the entire fitting portion (in other words, stress concentration at a specific point is prevented). (suppression) improves the shear strength, and this also reduces the possibility of residual fracture accidents.

The second joint portion 223 is provided on the other end surface of the trunk portion 22 (the lower end of the trunk portion 22 in FIG. 2 and the like). In this embodiment, the second joint portion 223 is a flat surface, and with this, the apparatus main body 22 and the chuck guide 25 can be connected by bringing the upper surface of the chuck guide 25, which is also a flat surface, into contact without a gap. . A connection bolt 251 is used to connect the device main body 22 and the chuck guide 25 .

The drive unit 220 has a structure capable of supplying a driving force using air as a power source, and adopts a piston structure in this embodiment. The drive unit 220 has substantially the same structure as a known down-the-hole hammer drive mechanism (for example, described in Japanese Patent Application Laid-Open No. 61-92288), and includes a cylinder, piston, check valve, air distributor, valve spring, makeup ring, It is a structure having an O-ring, a piston retainer ring, a bit retainer ring (reference numerals omitted), and the like.

Briefly explaining the operation of the drive unit 220, the air that has flowed into the drive unit 220 first passes through the side of the piston and goes around the drilling bit side (lower side of the drive unit 220 in FIG. Move to Next, as the piston moves, air flows toward the air tank side of the piston, and air is discharged from the air inlet 263 of the connecting shaft portion 260 of the drilling bit 26 to be described later to the opening air outlet 264 of the striking surface 262. This causes the piston to move from the air tank side to the drilling bit side.

By repeating this action, the piston advances and retreats, and when the piston moves toward the drilling bit, an impact force (corresponding to the aforementioned driving force) is applied to the drilling bit 26, and the drilling bit 26 is driven by this impact force. Further, the drive unit 4 is set so that the timing of inflow of air is adjusted by the air distributor 27 so that the pistons advance and retreat at different timings.

(chuck guide)
The chuck guide 25 has a substantially circular shape in a plan view with a notch formed on the side to be excavated and has a predetermined thickness, and has a plurality of guide holes 250 formed therein. Note that the upper surface of the chuck guide 25 is substantially flat and constitutes the fourth joint portion 252 . Also, the chuck guide 25 is connected to the device main body 22 via the second joint portion 223 using a fastening tool consisting of a connection bolt 251 and a nut (reference numerals omitted).

The guide holes 250 are through holes formed around the rotation axis of the chuck guide 25, parallel to the rotation axis, and communicating with the drive unit storage section 224. A total of four guide holes 250 are provided at equal intervals, It is formed to have a width in which a connection shaft portion 260 of the excavation bit 26, which will be described later, can be accommodated.

The guide hole 250 has a hexagonal inner diameter portion with a predetermined length extending from the opening in the lower end face in FIG. 260 can be inserted, and the connection shaft portion 260 can advance and retreat along the guide hole 250 in the inserted state.

That is, the chuck guide 25 can attach the drilling bit 26 through each guide hole 250, and the driving force from the drive unit 220 stored in the drive unit storage part 224 at the position communicating with the guide hole 250 is applied to the chuck guide 25 for drilling . Bit 26 can be conveyed.

(drilling bit)
Please refer to FIGS. 2, 4 and 5(a). The excavation bit 26 has a connecting shaft portion 260 and a head portion 261 provided at the lower end portion of the connecting shaft portion 260 (opposite direction to the drive unit 220) in FIG. 2 and the like, a hitting surface 262 is provided at the lower end portion of the head portion 261 (opposite direction to the connecting shaft portion 260), and an air discharge port 264 is formed substantially in the center.

The connection shaft portion 260 has a substantially cylindrical outer shape that can be fitted into the guide hole 250, the distal end is a free end formed with an air inlet 263, and the proximal end is fixed to the upper portion of the head portion 261. It is a connection means with the drive unit 220 . In addition, the flow path in the connection shaft portion 260 and the flow path formed in the head portion 261 communicate with each other to form an air flow path 265 . The air flow path 265 has an air inlet 263 as a starting point and an air outlet 264 as an end point, and a check valve (not shown) is provided in the flow path to prevent backflow of air toward the head portion 261 . .

More specifically, the connecting shaft portion 260 has a hexagonal outer peripheral surface from the axial center to the head portion 261 side in a cross-sectional view. , and is configured not to hinder forward and backward movement of the connecting shaft portion 260. As shown in FIG. Further, the connection shaft portion 260 is mounted so as not to come off from the guide hole 250 by the hammer bit retainer ring and the O-ring described above.

The head portion 261 has a substantially pentagonal prism shape, and the striking surface 262 also has a substantially pentagonal shape. The striking surface 262 has an arcuate portion along a portion of the outer circumference of the excavator 2 in a bottom view in a state of being attached to the chuck guide 25 (hereinafter simply referred to as "attached state" in this paragraph). , and a corner portion 267 having a right-angled tip is provided in the opposite direction of the arc-shaped portion (that is, toward the rotation axis of the excavator 2). The corner portion 267 has the same length on both sides sandwiching the same corner portion (equilateral).

In the head portion 261, button-shaped cemented carbide chips (reference numerals omitted) are implanted at predetermined intervals in the entire hitting surface 262 and in a portion of the sidewall rising from the hitting surface 262 near the hitting surface. (distributed arrangement).

The air discharge port 264 is formed substantially in the center of the striking surface 262, and the air passing through the air flow path 265 is discharged from here. Also, the air discharge port 264 is formed with two exhaust guide grooves 266 extending from the mouth edge toward the side edge direction of the striking surface 262 . The exhaust guide groove 266 guides the air discharged from the air discharge port 264 in the excavated hole H1 toward the outer surface of the excavator 2 between the hole bottom surface H3 and efficiently diffuses the air in the hole. Discharge of soil can be promoted.

In the drilling bit 26 configured as described above, the connecting shaft portion 260 advances and retreats along the guide hole 250, and the entire drilling bit 26 including the head portion 261 also advances and retreats accordingly. Excavation is performed by hitting the object to be excavated in front of the device 2 .

The four excavation bits 26 are arranged around the rotation axis 2R of the device main body so that the corners 267 are butted against each other. . In this embodiment, each excavation bit 26 has an arrangement in which the tips of the corners 267 are close to each other in the vicinity of the rotation axis 2R and none of the corners 267 overlaps the rotation axis 2R (hereinafter referred to as "rotational axis non-overlapping arrangement"). ).

In the drilling device 2, the drilling bits 26 are arranged in the above-described configuration, so that the striking surfaces 262 of the drilling bits 26 come together in close proximity to each other near the rotation axis 2R of the device main body. However, the structure is such that there are no extra gaps. According to this configuration, by performing the excavation work while rotating the excavator 2, the object to be excavated that is hit by each excavation bit 26 can be excavated evenly.

Since each drilling bit 26 has the same structure, there is no need to manufacture, purchase, or store two types of drilling bits, unlike the drilling bits 26a to 26f2 described later, and only one type of drilling bit can be procured. As a result, for example, when used as a replacement part or a spare part, even if any drilling bit is lost, only one type of drilling bit needs to be prepared. In addition, space can be saved during storage, and the number of replacement parts and the like to be brought to the site can be reduced.

(Air distributor)
The air distribution portion 27 is arranged on the upper surface of the first joint portion 222 inside the air tank 21 and has an air receiving portion 270 and a support base portion 271 . The air receiving portion 270 has a flat plate shape and a concave curved surface is formed on the upper portion thereof. The support base portion 271 has a cylindrical shape, supports the lower surface of the air receiving portion 270 at its upper end, and is fixed to the upper surface of the first joint portion 222 at its lower end. The air distribution portion 27 controls the flow direction of air supplied through the air introduction portion 211 in the air tank 21 .

Specifically, first, the air receiving portion 270 directly receives the air supplied from the direction of the air introducing portion 211, and then the air hits the air receiving portion 270, changes its direction of flow, and swirls within the air tank 21. Air circulation is controlled by flowing into the air introduction hole 226 of the device main body 22 at different timings. By changing the flow of air in the air tank 21 in this way, the arrival time of the air introduced from the air tank 21 to the drive unit 220 also changes, and the pistons of the drive unit 220 advance and retreat at different timings.

(rotation drive device)
In the present embodiment, the rotary drive device 3 includes a body portion 30 having a rotary table 31 formed with an insertion hole 311 penetrating in the vertical direction, and a support leg 32 having an outrigger structure for supporting the body portion 30. . The rotary table 31 has a driving portion (not shown) configured by a hydraulic motor, a gear device, and the like. Also, an engaging projection (not shown) is formed on the inner wall of the insertion hole 311 of the rotary table 31 in a direction along the central axis of the insertion hole 311 .

The rotation drive device 3 has the above-described configuration, so that when the drilling device 2 is passed through the insertion hole 311 of the rotary table 31, the locking projection provided in the device and the spiral blade 213 of the drilling device 2 are aligned. The locking recesses (reference numerals omitted) formed in are slidably locked, whereby the drilling device 2 attached to the rotary drive device 3 can be lowered by its own weight. Since the locking projection and the locking recess are in the locked state, the driving force from the rotary drive device 3 is applied to the excavator 2, and the excavator 2 can be driven to rotate in the horizontal direction. Note that the rotary drive device 3 has a known structure as disclosed in, for example, Japanese Patent Application Laid-Open No. 2011-26955, so the description of the structure and action is limited to the above-mentioned outline description, and the details are omitted.

[Modification 1]
Please refer to FIG. A drilling rig 2a shown in the figure is another aspect (modification 1) of the drilling rig 2, and differences will be described based on the drawings. Except for differences described later, the structure and effects of each part are substantially the same as those of the drilling rig 2, and thus the description thereof will be omitted.

The excavator 2a has three excavation bits 26a of the same shape. When viewed from the bottom, the drilling bit 26a has a corner portion 267a formed at an obtuse angle (approximately 120°) and has the same length on both sides sandwiching the corner portion 267a (equilateral). As a result, the striking surfaces 262a of the drilling bits 26a are arranged in a three-pronged manner with equal intervals in the circumferential direction.

Along with this difference, portions corresponding to the number of drilling bits 26a (drive unit storage portion 224 of body portion 221 of device main body 22, drive unit 220, air introduction hole 226, guide hole 250 of chuck guide 25) ) are also configured to have three each.

[Second embodiment]
Please refer to FIG. A drilling rig 2b shown in the figure is another aspect (second embodiment) of the drilling rig 2, and differences will be described based on the drawings. Except for differences described later, the structure and effects of each part are substantially the same as those of the drilling rig 2, and thus the description thereof will be omitted.

The drilling rig 2b is formed by combining two sets of drilling bits 26b1 and 26b2 having different shapes (four in total), and is a mode in which the second arrangement mode described above is applied to the arrangement of the striking surfaces. The drilling bits 26b1 and 26b2 have striking surfaces 262b1 (striking surface of the drilling bit 26b1) and 262b2 (striking surface of the drilling bit 26b2) arranged around the rotation axis 2R of the device main body, and have the same shape. The bits are arranged so that they are not adjacent to each other (that is, the drilling bits 26b1 are not adjacent to each other and the drilling bits 26b2 are not adjacent to each other).

The drilling bit 26b1 has a corner portion 267b1 on the striking surface 262b1, and the corner portion 267b1 has different lengths on both sides sandwiching the same corner portion (unequal sides). The drilling bit 26b2 has a corner portion 267b2 on the striking surface 262b2, and the corner portion 267b2 has the same length on both sides sandwiching the same corner portion (equilateral). The excavation bits 26b1 and 26b2 are collectively arranged so that the corners 267b1 and 267b2 face the direction of the rotation axis 2R of the device main body and are close to each other near the rotation axis 2R so that there is no gap. there is

The respective excavation bits 26b1 are arranged opposite to each other across the rotation axis 2R of the device main body, only the long sides of the corner portions 267b1 overlap with the rotation axis 2R of the device main body, and the tips of the corner portions 267b1 are located on the device main body. It is arranged so as not to overlap with the rotation axis 2R. The drilling bits 26b2 are arranged to face each other across the rotation axis 2R of the device body between the drilling bits 26b1 so that the tips and both sides of the corner portions 267b2 do not overlap the rotation axis 2R of the device body. are placed.

According to the drilling bits 26b1 and 26b2 arranged in the second arrangement mode, the striking surfaces 262b1 and 262b2 are attached to the rotation axis 2R of the device main body and its vicinity with almost no gap. According to this configuration, the object to be excavated H hit by the excavation bits 26b1 and 26b2 is excavated evenly, and the excavation hole H1 formed by the excavation work is substantially flat without forming a central protrusion on the inner bottom. become something.

Further, the excavation bits 26b1 and 26b2, which are arranged so that the rotation axis does not overlap, intermittently or substantially continuously rotate the rotation axis 2R of the device main body and the vicinity thereof during rotary excavation work. The long edge portion and the striking surfaces 262b1 and 262b2 along the portion are used for excavation. As a result, the load concentrated on the striking surface in the vicinity of the rotational axis 2R of the device main body is dispersed at a plurality of locations (two in this embodiment), and the concentration of the load on a small number of tips at the corners is alleviated. As a result, the formation of the central convex portion H6 is suppressed even when excavating hard rock, and accordingly the occurrence of the central deformed portion H7 is also suppressed.

The drilling bits 26b1 and 26b2 have different shapes and sizes of striking surfaces (the drilling bit 26b2 is smaller than the drilling bit 26b1). Only the long side portion of the drilling bit 26b1 is arranged close to the rotation axis 2R of the device body, while both sides of the drilling bit 26b2 sandwiching the same corner as the corner portion 267b2 are both close to the rotation axis 2R of the device body. It is not arranged (in other words, arranged apart from the rotation axis 2R of the apparatus main body).

The tips of the corners of the excavation bits 26b1 and 26b2 are located at positions that are about 6% of the distance from the rotation axis 2R of the device main body to the outer peripheral end of the body 221, with the rotation axis 2R of the device main body as a reference. set to be placed.

[Modification 2]
See FIG. 6(b). A drilling rig 2c shown in the figure is another aspect (modification 2) of the drilling rig 2b, and differences will be described based on the drawings. Except for differences described later, the structure and effects of each part are substantially the same as those of the drilling rig 2b, and thus the description thereof is omitted. Further, in the second modification, as in the first modification, the number of portions corresponding to the number of drilling bits (the drive unit housing portion, the drive unit, the air introduction hole, and the guide hole in the chuck guide 25) is also three. It is configured to have each.

The excavator 2c is formed by combining two sets of excavating bits 26c1 and 26c2 (three in total) having different shapes, and is a mode in which the first arrangement mode described above is applied to the arrangement of the striking surfaces. The drilling bits 26c1 and 26c2 have striking surfaces 262c1 (striking surface of the drilling bit 26c1) and 262c2 (striking surface of the drilling bit 26c2) arranged around the rotation axis 2R of the device main body. are arranged in a three-pronged manner with equal intervals in the circumferential direction.

The drilling bit 26c1 has a corner portion 267c1 on the striking surface 262c1, and the corner portion 267c1 has the same length on both sides sandwiching the same corner portion (equilateral). The drilling bit 26c2 has a corner portion 267c2 on the striking surface 262c2, and the corner portion 267c2 has different lengths on both sides sandwiching the same corner portion (unequal sides). The excavation bits 26c1 and 26c2 are collectively arranged so that the corners 267c1 and 267c2 face the direction of the rotation axis 2R of the device body and are close to each other in the vicinity of the rotation axis 2R so that there is no gap. there is

The striking surface 262c1 is formed slightly larger than the striking surface 262c2, and the tip of the corner portion 267c1 extends beyond the rotation axis 2R of the apparatus body (including the rotation axis). It is an overlapping arrangement. That is, only the corner portion 267c1 is arranged so as to overlap the rotation axis 2R of the apparatus main body, and the corner portion 267c2 is arranged so as not to overlap the rotation axis 2R of the apparatus main body. Each hitting surface 262c2 is arranged such that one side edge of the corner portion 267c2 is adjacent to the diameter line, and the other side edge is adjacent to the corner portion 267c1.

According to the drilling bits 26c1 and 26c2 arranged in the first arrangement mode, the striking surfaces 262c1 and 262c2 are attached to the rotation axis 2R of the device main body and its vicinity with almost no gap. According to this configuration, the object to be excavated H hit by the excavation bits 26c1 and 26c2 is excavated evenly, and the excavation hole H1 formed by the excavation work is substantially flat without forming a central protrusion on the inner bottom. become something.

Further, the drilling bits 26c1 and 26c2 drill while the striking surface 267c1 of the drilling bit 26c1 always passes through the rotation axis 2R of the device main body and its vicinity during rotary drilling work. As a result, the load concentrated on the striking surface in the vicinity of the rotational axis 2R of the device main body is received by the corner 267c1, which is relatively wide and has a large number of chips, so that the load concentration is alleviated. Also during excavation, the formation of the central protrusion H6 is suppressed, and along with this, the occurrence of the central deformed portion H7 is also suppressed.

The tips of the corners of the excavation bits 26c1 and 26c2 are about 5.4% of the distance from the rotation axis 2R of the device main body to the outer peripheral end of the body 221, with the rotation axis 2R of the device main body as a reference. It is set to be placed in place.

[Third Embodiment]
Please refer to FIG. A drilling rig 2d shown in the figure is another aspect (a third embodiment) of the drilling rig 2, and differences will be described based on the drawings. Except for differences described later, the structure and effects of each part are substantially the same as those of the drilling rig 2, and thus the description thereof will be omitted.

Like the drilling rig 2b, the drilling rig 2d is formed by combining two sets of drilling bits 26b1 and 26b2 having different shapes (four in total), and is a mode in which the second arrangement mode described above is applied to the arrangement of the striking surfaces. . In the excavator 2d, the four drive units 220a, 220b, 220c, and 220d are arranged in each excavation bit in which the striking surface overlaps the rotation axis only at the edge on the rotation axis side. It has a structure that gives the maximum impact force.

The drive units 220a, 220b, 220c, and 220d are set so that the cylinders have different diameters and the weights of the built-in pistons are different.

Specifically, with the excavation bit 26b1 located on the lower right side of FIG. , and the drive unit 220b that supplies drive to its clockwise circumferentially adjacent drill bit 26b2 has a diameter of 6 inches (152.4 mm) and weighs 23 kg and its clockwise circumferentially adjacent drill bit. The drive unit 220c that supplies drive to 26b1 is 8 inches (203.8 mm) in diameter and weighs 31 kg, and its clockwise circumferentially adjacent drill bit 26b1 is driven by: It has a diameter of 5 inches (127 mm) and a weight of 9.4 kg.

In this way, the drive unit 220a having the largest piston is attached to the largest striking surface (the striking surface 262b1 of the excavating bit 26b1) among the drilling bits 26b1 and 26b2, and the maximum striking force is applied. , during a rotary drilling operation, the drilling bit 26b1 crushes the hard rock H4, or cracks the hard rock H4 so that it can be broken into small pieces by subsequent impacts of other drilling bits 26b1, 26b2.

According to the excavator 2d, the increase in the weight of the entire apparatus and the increase in the consumption of working fluid (air) are suppressed to the necessary minimum, while suppressing the formation of the central convex portion H6 and the occurrence of the central deformation portion H7 during excavation of hard rock. Each effect of suppression can be further enhanced.

[Modification 3]
Refer to FIG. 7(b). A drilling rig 2e shown in the figure is another aspect (modification 3) of the drilling rig 2d, and differences will be described based on the drawings. Except for differences described later, the structure and effects of each part are substantially the same as those of the drilling rig 2d, and thus the description thereof is omitted. Further, in the third modification, as in the first modification, the number of portions corresponding to the number of drilling bits (the drive unit housing portion, the drive unit, the air introduction hole, and the guide hole in the chuck guide 25) is also three. It is configured to have each.

Like the drilling rig 2c, the drilling rig 2e is formed by combining two sets of drilling bits 26c1 and 26c2 having different shapes (three in total), and is a mode in which the first arrangement mode described above is applied to the arrangement of the striking surfaces. . The excavator 2e has a structure in which the three drive units 220e, 220f, and 220g apply the maximum striking force among the excavating bits to the excavating bits whose striking surfaces overlap the rotation axis. It's becoming

The drive units 220e, 220f, and 220g are set so that the cylinders have different diameters and the weights of the built-in pistons are different.

Specifically, with the excavation bit 26c1 positioned at the bottom center of FIG. , and the drive unit 220f that supplies drive to its clockwise circumferentially adjacent drill bit 26b2 has a diameter of 8 inches (203.8 mm) and weighs 31 kg and its clockwise circumferentially adjacent drill bit. The drive unit 220g that supplies drive power to 26b2 has a diameter of 6 inches (152.4 mm) and a weight of 23 kg.

The excavator 2e also suppresses the formation of the central convex portion H6 and the occurrence of the central deformed portion H7 during hard rock excavation, while minimizing the increase in the weight of the entire device and the increase in the consumption of working fluid (air). Each effect of can be further enhanced.

[Modification 4]
Refer to FIG. 7(c). A drilling rig 2f shown in the figure is another aspect (modification 4) of the drilling rig 2d, and differences will be described based on the drawings. Except for differences described later, the structure and effects of each part are substantially the same as those of the drilling rig 2d, and thus the description thereof is omitted. Also in Modification 4, as in Modification 1, the number of portions corresponding to the number of drilling bits (the drive unit storage portion, the drive unit, the air introduction hole, and the guide hole in the chuck guide 25) is two. It is configured to have each.

The excavator 2f is formed by combining two sets of excavating bits 26f1 and 26f2 having different shapes (two in total), and is a mode in which the first arrangement mode described above is applied to the arrangement of the striking surfaces. The striking surfaces of the drilling bits 26f1 and 26f2 are substantially semicircular, and the striking surface 262f1 of the drilling bit 26f1 is larger than the striking surface 262f2 of the drilling bit 26f2. The edge of the striking surface 262f1 of the excavating bit 26f1 on the side of the rotation axis 2R of the device main body extends beyond the rotation axis 2R of the device main body (in other words, including the rotation axis). Cardiac overlapping placement. That is, only the striking surface 262f1 overlaps the rotation axis 2R of the device main body, and the striking surface 262f2 is arranged so as not to overlap the rotation axis 2R of the device main body.

In the excavator 2f, the two drive units 220h and 220i are set so that the cylinders have different diameters and the weights of the built-in pistons are different. It has a structure that gives the maximum impact force among each drilling bit to each drilling bit.

Specifically, with the excavation bit 26f1 positioned on the lower left side of FIG. , the drive unit 220i, which provides drive to the adjacent drilling bit 26f2, is set to have a diameter of 8 inches (203.8 mm) and a weight of 31 kg.

Although the drilling rig 2f yields to the other drilling rigs described above in terms of quietness and low vibration, it has less vibration and noise than a single-bit down-the-hole hammer, and has a greater impact force than the other drilling rigs. , can be suitably used for excavated objects containing a large amount of hard rock. The excavator 2f also suppresses the formation of the central convex portion H6 and the deformation of the central deformed portion H7 during hard rock excavation, while minimizing an increase in the weight of the entire device and an increase in the consumption of working fluid (air). Each effect of occurrence suppression can be further enhanced.

In this modification, the drive unit of the excavator 2f is set so that the cylinder diameter and the piston weight are different, but this is not restrictive. may be in the same manner.

[Fourth Embodiment]
Refer to FIGS. 8(a) and 8(b). A drilling rig 2g shown in the figure is another aspect (fourth embodiment) of the drilling rig 2, and differences will be described based on the drawings. Except for differences described later, the structure and effects of each part are substantially the same as those of the drilling rig 2, and thus the description thereof will be omitted.

The drilling rig 2g differs from the drilling rig 2 in the structure of the drilling bit, and the drilling rig 2g is a combination of four drilling bits 26g. Each excavation bit 26g is formed with a ridge striking portion 268 protruding from the striking surface 262g toward the object to be excavated along the outer peripheral edge of the excavation bit 26g as viewed in the direction of the rotation axis.

The ridge striking portion 268 has an inclined surface formed between it and the flat portion of the striking surface 262g. The projection height of the ridge striking portion 268 is set to 3 cm from the flat portion.

The drilling rig 2g can apply an initial impact to the drilled object with a ridge striker 268 that concentrates the load along the ridge at each drilling bit 26g, thus providing more impact than a flat striking surface. The force is improved, and even if the object to be excavated is hard rock in an excavation hole, the hard rock can be crushed by this impact.

In addition, since the drilling device 2g has the ridge striking portion 268, it is possible to cope with both soft layers and hard rocks without having to replace the equipment. can be omitted. Also, when excavating hard rock, excavation work can be performed with relatively low noise and low vibration. In addition, the ridge striking portion 268 is set to the above-described inclination angle and projection height, so that it has a structure that is resistant to chipping and exhibits excellent durability.

[Modification 5]
See FIG. 8(c). A drilling rig 2h shown in the figure is another aspect (modification 5) of the drilling rig 2g, and differences will be described based on the drawings. Except for differences described later, the structure and effects of each part are substantially the same as those of the drilling rig 2, and thus the description thereof will be omitted.

The excavator 2h has three excavation bits 26h of the same shape, and is arranged in a three-pronged manner at regular intervals in the circumferential direction when viewed from the bottom. Each excavation bit 26h is formed with a ridge striking portion 268 protruding from the striking surface 262h toward the object to be excavated along the outer peripheral edge of the excavation bit 26g as viewed in the rotation axis direction. The ridge striking portion 268 has an inclined surface formed between it and the flat portion of the striking surface 262h. The projection height of the ridge striking portion 268 is set to 3 cm from the flat portion.

Due to this difference, the number of parts corresponding to the number of drilling bits 26h (the drive unit storage section, the drive unit, the air introduction hole, and the guide hole in the chuck guide) is also three. there is

[Fifth embodiment]
Please refer to FIGS. The drilling rig 2i shown in the figure is another aspect (fifth embodiment) of the drilling rig 2, and the differences will be described based on the drawings. Except for differences described later, the structure and effects of each part are substantially the same as those of the drilling rig 2, and thus the description thereof will be omitted.

In the excavator 2i, a welded portion 217 is formed by welding on the outer surface of the joint portion between the lower end of the air tank 21 and the upper end of the device main body 22 . This welded portion 217 improves wear resistance, rigidity against shear stress, and locking force at the joint between the lower end of the air tank 21 and the upper end of the device main body 22 .

Further, in the excavator 2i, the second joint portion 223i of the device main body 22 forms a disc-shaped convex portion having a diameter smaller than the outer diameter of the middle portion in the longitudinal direction of the body portion 221, and is recessed along the extension direction of the guide hole 250. The upper surface of the chuck guide 25 (the end surface in the direction of the apparatus main body 22) is formed with a concave portion in which the second joint portion 223i is just received. It is a structure having a fourth joint portion 252i.

By having this structure, the second joint portion 223i and the fourth joint portion 252i are joined with a fitting structure by unevenness, and the second joint portion 223i enters and integrates with the fourth joint portion 252i, so that the excavator 2i is formed. It can disperse the stress over the entire fitting portion (in other words, suppress the stress concentration at a specific point) against the external force applied in the direction that intersects the longitudinal direction, reducing the possibility of residual fracture accidents. be able to. Further, since the convex portion of the second joint portion 223i is cut into a concave curved surface along the extension direction of the guide hole 250, the forward and backward movement of the connecting shaft portion 260 of the excavation bit is not hindered.

Furthermore, the excavator 2i is provided with a detent structure 4 on a contact surface where the second joint portion 223i and the fourth joint portion 252i abut. The anti-rotation structure 4 includes first fitting holes 41 (three in total) provided in the second joint portion 223i and second fitting holes provided in the fourth joint portion 252i at positions corresponding to the first fitting holes 41. 42 (three places in total) are formed, and a detent shaft 43 having a length and a thickness that can be just fitted in both mutually aligned holes is fitted.

By having the anti-rotation structure 4, it is possible to prevent the second joint portion 223i and the fourth joint portion 252i from sliding against each other on the contact surfaces during rotary excavation work of the excavator 2i. As a result, the rigidity against shearing stress generated at the seam between the device main body 22 and the chuck guide 25 is improved compared to a structure in which the connection bolt 251 is joined alone, and a fracture residual accident occurs between the device main body 22 and the chuck guide 25. Possibility can be reduced.

A recess 253 is formed along the edge of the fourth joint portion 252i and the guide hole 250, and a rubber ring 254 slightly larger in width and depth than the recess is press-fitted into the recess. , it is configured to suppress rattling and exhibit a cushioning effect.

The excavator 2-2i has two to four drive units 220-220i housed in the device main body 22, but is not limited to this, and may have, for example, five or more. In that case, the number of drive unit housings, the number of excavation bits, etc. may be appropriately changed to match this number.

The device main body 22 is provided with a flat bar parallel to the longitudinal direction of the outer periphery of the body portion 221, but is not limited to this. Various modifications such as a mode in which spiral blades are provided and a mode in which reinforcing ribs are provided between spiral blades are not excluded.

As an example of the first joint portion, the apparatus main body 22 has a structure composed of a substantially cylindrical convex portion having a smaller diameter than the outer diameter of the middle portion in the longitudinal direction of the trunk portion, but it is not limited to this. Instead, it may be, for example, an elliptical columnar protrusion, a triangular columnar protrusion, a square or other polygonal columnar protrusion, and the shape of the third joint of the air tank 21 may also be changed to match the shape of the first joint. . In this case, for the detachment restraint structure, for example, known means such as fixing with a locking pin penetrating both the third joint portion and the first joint portion may be applied.

In addition, although the first joint portion 222 has a height of about 20 cm from the base end to the upper end, it is not limited to this. The height is preferably in the range 10 cm-30 cm. If it is less than 10 cm, the fitting part becomes small, and the effect of improving the shear strength by dispersing the stress as a whole cannot be expected much, which is not preferable. This is also not desirable because the tank capacity will be smaller.

Furthermore, the second joint portion of the apparatus main body 22 and the fourth joint portion of the chuck guide 25 may have a structure in which the unevenness is reversed (the second joint portion is a concave portion and the fourth joint portion is a convex portion). And, the shape of the convex portion is not limited to the shape described above, and may be appropriately changed to another shape.

The drilling bits 26-26h have one air discharge port provided on the striking surfaces 262-262h, but this is not a limitation. may be provided two or more. When two or more air discharge ports are provided, it is possible to facilitate the diffusion of excavated debris in the circumferential direction at the bottom of the excavated hole, thereby further promoting the efficiency of earth removal.

Further, the drilling bits 26 to 26h are formed so that the exhaust guide grooves 266 are oriented in different directions from the rim of the air discharge port 264 (the two lines join together around the air discharge port 264, so it can be expressed as one line). However, it is not limited to this. For example, the number of exhaust guide grooves may be one or three or more, and the exhaust guide grooves 266 may be oriented in the same direction. good too.

Furthermore, although the excavation bits 26-26h have chips dispersedly planted on the striking surfaces 262-262h, the present invention is not limited to this. As a result of connecting the flat surface and the recessed portion, the flat surface may be substantially a convex portion and substitute for the function of the chip.

When each drilling bit is arranged in the first arrangement mode or the second arrangement mode, each drilling bit is arranged so that the tip of the corner thereof is positioned relative to the rotation axis 2R of the device main body. Although it is set to be placed at a location that is about 6% of the distance from 2R to the outer peripheral edge of the body 221, it is not limited to this, and for example, the distance is 5% to 30% of the radius. It is preferably set so as to fit inside the area. If it is less than 5%, the corner portion is too close to the center of rotation, and a central protrusion H6 is formed at the center of the deep side of the excavated hole during hard rock excavation, as shown in FIG. 12(c). On the other hand, if it exceeds 30%, there is a possibility that the drilling bit will be smaller than the diameter of the piston member, and the transmission efficiency of the impact force will decrease. It is also not preferred because of the risk of

The drilling bits 26-26h have striking surfaces 262-262h formed in a pentagonal or substantially semicircular shape, but are not limited to this. It may be rectangular or the like, and when a plurality of drilling bits are attached to the drilling device, the portions of the drilling bits in the direction of the rotation axis 2R of the device body are close to each other in the vicinity of the rotation shaft and form a gap. It is sufficient that they are collectively arranged so that there is no empty space. Further, the head portion is not limited to a prism shape, and may be a truncated cone shape whose bottom surface serves as a striking surface.

The ridge striking part 268 provided on the excavation bit has an inclined surface with an inclination angle of 35°, but the inclination angle is not limited to this, and may be, for example, within a range of 20° to 60°. , more preferably 30° to 50°. If the angle of inclination is less than 20°, the entire inclined surface of the striking surface portion becomes too wide and flat as a whole. On the other hand, if the angle of inclination exceeds 60°, the ridge striking portion protrudes too sharply, and the ridge striking portion tends to be chipped when hitting hard rock, which is also undesirable. be.

In addition, the projection striking part 268 has a projection height of 3 cm from the flat portion of the striking surface, but is not limited to this. It is preferably 3 to 5 cm, more preferably 3 to 5 cm. If the protrusion height is less than 2 cm, the protrusion height from the flat portion is low, so it is not preferable because it is difficult to exert a striking force that bites into hard rock. This is because the ridge hitting part is likely to be chipped when hitting hard rock, which is also not preferable.

The illustrated air distribution portion 27 has a cup shape, but it is not limited to this. 222, which is rotatably mounted along the upper surface of the device body 22 and intermittently closes the air introduction hole 226 formed in the apparatus main body 22 as it rotates; There is no particular limitation as long as it is designed with a shape or structure that does not allow the air in the air tank to flow into the drive unit at the same timing, such as a structure that changes the inflow timing by dividing the length of the path. do not have.

The illustrated rotary drive device 3 is of a mode that imparts a rotational force to the excavating devices 2a-2i so that they can be lowered by their own weight, but is not limited to this. A mode having a mechanism for pushing the excavator toward the object to be excavated may be used. Although the illustrated rotation drive device 3 is provided in a table shape, it is not limited to this. The device is not particularly limited as long as it can apply a rotational force to the excavator, such as a rotary drive device that applies a rotational force to the excavator.

The terms and expressions used in the specification and claims are for the purpose of description only and are not limiting in nature. There is no intention to exclude some equivalent terms or expressions. Moreover, it goes without saying that various modifications are possible within the scope of the technical idea of the present invention. Also, the terms first, second, etc. do not imply a degree or importance, but are used to distinguish one element from another.

Reference Signs List 1 rotary excavator 2, 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i excavator 2R rotation axis of device main body 21 air tank 210 tank body 211 air introducing portion 212 third joint 213 spiral Blade 214 Opening 215 Flow passage 216 Female thread 217 Welded portion 21M Maximum diameter portion of tank body 22 Device main body 220, 220a, 220b, 220c, 220d, 220e, 220f, 220g, 220h, 220i Drive unit 221 Body 222 1 joint portion 223, 223i 2nd joint portion 224 drive unit storage portion 225 male screw 226 air introduction hole 22M maximum diameter portion of device body 25 chuck guide 250 guide hole 251 connection bolt 252, 252i fourth joint portion 253 recess 254 rubber ring 26, 26a, 26b1, 26b2, 26c1, 26c2, 26f1, 26f2, 26g, 26h Drilling bit 260 Connection shaft 261 Head 262, 262a, 262b1d, 262b2, 262c1, 262c2, 262f1, 262f2, 262g, 262h Striking surface 263 Air inlet 264 Air outlet 265 Air channel 266 Exhaust guide groove 267 , 267 a , 267 b 1 , 267 b 2 , 267 c 1 , 267 c 2 Corner portion 268 Projection hitting portion 27 Air distribution portion 270 Air receiving portion 271 Support base portion 3 Rotation drive device 30 Body Part 31 Rotating Table 311 Insertion Hole 32 Supporting Leg 34 Hanging Shaft 341 Air Supply Pipe 4 Anti-rotation Structure 41 First Insertion Hole 42 Second Insertion Hole 43 Anti-rotation Shaft 9 Drilling Device 91 Central Bit 92 Peripheral Bit 93 Prototype 930 drilling bit 931 striking surface 933 corner 934 chip 9R rotation axis H object to be drilled H1 drilling hole H6 central protrusion H7 central deformation

Claims (7)

A columnar body rotatable in an axial circumferential direction about a rotation axis, and a plurality of drive unit storage sections are formed around the rotation axis in parallel with the rotation axis, and the drive unit storage section is excluded. A body having a substantially solid structure, a plurality of drive units individually stored in the drive unit storage section and capable of supplying a driving force using air as a power source, and a second drive unit on one end surface of the body. an apparatus main body in which a first joint portion is formed, an air introduction hole communicating with the drive unit storage portion is formed in the same end surface, and a second joint portion is formed in the other end surface of the body portion;
An air introduction part that is attached so as to rotate together with the apparatus main body and is capable of introducing air from the outside of the apparatus, and a disengagement of the first joint part that is joined to the first joint part with a fitting structure and is in a fitted state. an air tank formed with a third joint including a detachment suppression structure that suppresses
A chuck mounted so as to rotate together with the apparatus main body, formed with a fourth joint portion joined to the second joint portion, and formed with a plurality of through guide holes arranged to communicate with the drive unit storage portion. a guide and
It has a connection shaft portion which is a portion to be attached to the chuck guide, and a head portion including a striking surface provided at the tip of the connection shaft portion. a plurality of drilling bits each axially moved forward and backward by receiving a driving force from the drive unit;
an air distribution unit capable of distributing the air supplied to the drive unit so that part or all of the drilling bits advance and retreat at different timings ;
The second joint portion is formed by cutting out a disk-shaped convex portion having a smaller diameter than the outer diameter of the middle portion in the longitudinal direction of the body portion into a concave curved surface along the extension direction of the guide hole. In addition, the fourth joint portion is formed in a recessed shape in which the second joint portion is just accommodated in the end face of the chuck guide in the apparatus main body direction.
drilling rig. a first arrangement mode in which the striking surfaces of each of the drilling bits are arranged around the rotation axis of the chuck guide, and only one of the striking surfaces is arranged to overlap the rotation axis; or A corner portion is formed on the rotation axis side of the striking surface, and only the edges on the rotation axis side of the pair of striking surfaces arranged opposite to each other across the rotation axis overlap with the rotation axis. and a second arrangement mode in which the tips of the corners are arranged so as not to overlap the rotation axis, and the edge of each of the striking surfaces on the rotation axis side is the rotation axis. 2. Drilling rig according to claim 1, in a contiguously clustered configuration near the core. The driving unit is the excavating bit in which the striking surface overlaps with the rotation axis in the first arrangement mode, or the striking surface is arranged on the side edge of the rotation axis in the second arrangement mode. 3. The excavation according to claim 2, wherein the excavation according to claim 2 is set so as to apply a maximum striking force among the plurality of excavation bits to one of the excavation bits arranged so as to overlap with the rotation axis only at a portion thereof. Device. Each of the excavation bits has a ridge striking portion projecting from the striking surface toward the object to be excavated along a position corresponding to the outer peripheral edge of the excavation bit when viewed in the direction of the rotation axis of the chuck guide. A drilling rig according to claim 1, claim 2 or claim 3. The first joint portion is configured by a substantially cylindrical projection having a smaller diameter than the outer diameter of the middle portion in the longitudinal direction of the body, and a male screw is provided on the side surface of the projection,
1, 2, 3 or claim 1, 2, 3, or claim 3, wherein the third joint is an opening having an inner diameter that accommodates the first joint, and a female screw is provided on the inner surface near the opening. Item 5. The drilling rig according to item 4. A detent structure is provided on a contact surface where the second joint portion and the fourth joint portion abut.
A drilling rig according to claim 1, claim 2, claim 3, claim 4 or claim 5. A columnar body rotatable in an axial circumferential direction about a rotation axis, and a plurality of drive unit storage sections are formed around the rotation axis in parallel with the rotation axis, and the drive unit storage section is excluded. A body portion having a substantially solid structure, a plurality of drive units individually stored in each of the drive unit storage portions and capable of supplying a driving force using air as a power source, and a first end face of the body portion. An apparatus main body in which a first joint portion is formed, an air introduction hole communicating with the drive unit storage portion is formed in the same end surface, and a second joint portion is formed in the other end surface of the body portion, together with the apparatus main body An air introduction part that is rotatably attached and capable of introducing air from outside the machine, and a detachment that is joined to the first joint part with a fitting structure and suppresses separation of the first joint part in the fitted state. An air tank formed with a third joint including a restraint structure, mounted to rotate together with the apparatus main body, formed with a fourth joint that joins with the second joint, and communicates with the drive unit housing. a chuck guide in which a plurality of through-holes are formed in such an arrangement that the head portion includes a connecting shaft portion to be attached to the chuck guide; and a hitting surface provided at the tip of the connecting shaft portion A plurality of excavation bits, each of which receives a driving force from the drive unit through the connecting shaft portion inserted into each of the guide holes and moves forward and backward in the axial direction, and part or all of the excavation bits are timing. It has an air distribution portion capable of distributing the air supplied to the drive unit so as to move forward and backward differently, and the second joint portion has a smaller diameter than the outer diameter of the longitudinally intermediate portion of the body portion. The disc-shaped convex portion is formed by cutting a concave curved surface along the extension direction of the guide hole, and the fourth joint portion is formed on the end face of the chuck guide in the direction of the main body of the apparatus, and the second A drilling rig that is configured in a concave shape in which the joint portion fits exactly;
and a rotary drive device that imparts a rotary force to the drilling device.
rotary excavator.

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