JP2013053473A - Self-propelled drilling machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce equipment costs by dispensing with preparation of a plurality of drilling machine bodies corresponding to diameters of underground holes, even when drilling underground holes with different diameters.SOLUTION: A self-propelled drilling machine, which has a pointed head part 20 provided on the front end side of a cylindrical barrel part 10, is configured to move forward while forming an underground hole in a form which makes the head part 20 protrude from/recede into the barrel part 10. A cover body C, which is formed in such a cylindrical shape that a maximum diameter is larger than a diameter of the barrel part 10 and the front end side and back end side of which are formed in such a cone shape as to have diameters smaller toward an end, is detachably provided in a drilling machine body J. The cover body C is configured to protrude/recede integrally with the head part 20 when the drilling machine body J moves forward.

Description

In the present invention, a pointed head portion is provided on the front end side of the cylindrical body portion and a bottom wall portion is provided on the rear end side, and the head portion moves back and forth in the axial direction of the body portion. The structure is freely provided and urged in the retraction direction, and is slidable along the axial direction inside the body part, and gives an impact force to the head part or the bottom wall part. It has a through-hole machine body provided with a free piston,
A pressurized gas for driving the piston to the front end side or the rear end side of the body part is supplied to the through-hole machine body by a compressor, and the piston is moved to the front end side of the body part to move to the head part. Applying an impact force, the head unit moves forward and backward while forming a ground hole in a form in which the head unit moves forward and backward with respect to the body unit, and the piston is moved to the body unit. The present invention relates to a self-propelled through-hole machine configured to move to the rear end side to apply an impact force to the bottom wall portion and to move backward in the underground hole drilled by the through-hole machine body.

Such a self-propelled through-hole machine drills an underground hole starting from the start side shaft and ending at the end side shaft without opening the ground, for example, for laying a gas pipe or the like.
A self-propelled through-hole machine has a through-hole machine body, and advances or retreats in the ground by supplying pressurized gas intermittently from the compressor to the through-hole machine body.
More specifically, the penetrating machine main body is provided with a pointed head portion on the front end side of the cylindrical body portion, provided inside the body portion, and slidably moved along its axial direction. A flexible piston moves forward while forming an underground hole in a state in which an impact force is applied to the head portion by the pressurized gas supplied from the compressor and the head portion is moved back and forth relative to the body portion. To do.
Further, the through-hole machine body has a bottom wall portion provided on the rear end side of the cylindrical body portion, and the piston gives an impact force to the bottom wall portion by the pressurized gas supplied from the compressor. Then, the drilled underground hole is moved backward (see, for example, Patent Document 1).

JP-A-9-136705

  Conventionally, the diameter of the underground hole that can be drilled by the self-propelled through-hole machine configured as described above is that of the cylindrical body part of the through-hole machine body and the pointed head part provided on the front end side thereof. Since it was defined by the diameter, it was necessary to prepare a plurality of through-hole machine bodies corresponding to the intended diameter of the underground hole and selectively use them. For this reason, in order to drill underground holes with a plurality of different diameters, it is necessary to prepare a plurality of through-hole machine bodies corresponding to the diameter of the target underground hole, which increases the equipment cost. .

  The present invention has been made in view of the above circumstances, and the object thereof is to make it unnecessary to prepare a plurality of through-hole machine bodies corresponding to the diameters even when drilling underground holes having different diameters. It is to realize reduction of equipment cost.

The first characteristic configuration of the self-propelled through-hole machine according to the present invention for achieving the above object is that a pointed head portion is provided on the front end side of the cylindrical body portion, and a bottom wall portion is provided on the rear end side. And the head portion is slidably moved along the axial direction inside the body portion, and is configured to be movable in and out in the axial direction of the body portion and biased in the retracting direction. It is configured to have a through-hole machine body provided with a piston that is movable and movable, and is capable of imparting an impact force to the head portion or the bottom wall portion,
A pressurized gas for driving the piston to the front end side or the rear end side of the body part is supplied to the through-hole machine body by a compressor, and the piston is moved to the front end side of the body part to move to the head part. Applying an impact force, the head unit moves forward and backward while forming a ground hole in a form in which the head unit moves forward and backward with respect to the body unit, and the piston is moved to the body unit. It is configured to move to the rear end side to apply an impact force to the bottom wall portion and to retreat the underground hole drilled by the through-hole machine body,
A cover body that is formed in a cylindrical shape whose maximum diameter is larger than that of the body portion, and whose front end side and rear end side are formed in a conical shape having a smaller diameter toward the end portion, Removably provided on the front end side,
The said cover body exists in the point comprised so that the said head part may move in and out integrally at the time of the forward movement of the said through-hole machine main body.

  That is, the maximum diameter is larger than that of the fuselage portion on the front end side of the through-hole machine body in which the pointed head portion is provided on the front end side of the cylindrical body portion and the bottom wall portion is provided on the rear end side. A cover body that is formed in a cylindrical shape and that moves in and out integrally with the head portion when the through-hole machine body moves forward is mounted. Therefore, when the penetrating machine main body moves forward, an underground hole having a diameter of the cover body whose maximum diameter is larger than that of the body portion can be drilled.

  If one or more cover bodies having a diameter larger than the diameter of the through-hole machine main body are prepared for one through-hole machine main body, However, it is not necessary to prepare a through-hole body having a plurality of diameters. Since the cover body has a simpler structure than the through-hole machine body and is less expensive to manufacture, the cover body can be attached to the through-hole machine body as in the first feature configuration, Compared with preparing a plurality of through-hole machine bodies having different diameters, the equipment cost can be reduced.

  In short, according to the first characteristic configuration, even when drilling underground holes of different diameters, it is not necessary to prepare a plurality of through-hole machine bodies corresponding to the diameters, and the equipment cost can be reduced.

  The second characteristic configuration of the self-propelled through-hole machine according to the present invention includes, in addition to the first characteristic configuration described above, an outer peripheral stone with respect to the movement of the cover body in the axial direction on the outer peripheral portion of the cover body. Is provided with a resistance portion that generates a resistance between them.

  In other words, the movement of the cover body in the axial direction is suppressed by the resistance between the resistance portion provided on the outer peripheral portion of the cover body and the earth and stone around the cover body. The cover body moves in and out integrally with the head portion of the through-hole machine body, but when the head portion retreats during the forward movement of the through-hole body, the cover body and the surrounding debris If the resistance between them is small, there is a risk that the cover body that moves in and out integrally with the head portion will retreat in a state of being pulled toward the body portion, and it is difficult for the through hole machine body to move forward. On the other hand, according to the second characteristic configuration, resistance is generated between the cover body and the surrounding earth and stone by the resistance portion, so that when the head portion retreats during the forward movement of the through-hole machine body, the cover The body is restrained from moving in the axial direction between the surrounding earth and stone, and the cover body draws the body part in the forward direction while the position of the cover body is fixed in the underground hole. Therefore, the underground hole can be efficiently drilled in a form in which the cover body is moved in and out integrally with the head portion of the through hole machine main body.

  The third characteristic configuration of the self-propelled through-hole machine according to the present invention is that, in addition to the second characteristic configuration, the resistance portion is a plurality of grooves along the circumferential direction of the cover body.

  That is, since the resistance portion is constituted by a plurality of groove portions along the circumferential direction of the cover body, the surface of the groove portion along the radial direction of the cover body or the cover for the movement in the axial direction of the cover body or the cover A surface inclined with respect to the outer peripheral surface of the body causes resistance to surrounding debris. Moreover, since the resistance portion has a simple configuration in which the groove portion is formed in the circumferential direction with respect to the cover body, the cost required for processing can be reduced.

A fourth feature configuration of the self-propelled through-hole machine according to the present invention is that, in addition to any of the first to third feature configurations, the cover body has an inner peripheral surface of a conical portion on the front end side thereof. It is formed in a shape along the outer peripheral surface of the head part,
A holding means for holding the cover body in the axial direction with respect to the through-hole machine body when the through-hole machine body moves backward in the mounted state of the cover body is provided.

That is, since the inner peripheral surface of the conical portion on the front end side of the cover body is formed in a shape along the outer peripheral surface of the head portion, when the head portion protrudes from the body portion, the conical shape on the front end side of the cover body The cover body projects and moves integrally with the head portion from the body portion in a state where the inner peripheral surface of the portion is in contact with the outer peripheral surface of the head portion.
Further, since the holding means holds the cover body in the axial direction with respect to the through-hole machine body when the through-hole body is moved backward with the cover body mounted, when the through-hole body is moved backward, In this case, the cover body is held in the axial direction with respect to the through hole machine body by the holding means, and even if the through hole machine body moves backward, the position of the cover body does not change in the axial direction from the through hole machine body. That is, the cover body and the through-hole machine main body can be moved backward integrally without causing a state in which only the through-hole machine main body moves backward while leaving the cover body at the original position in the stone. .

According to a fifth feature of the self-propelled through hole machine according to the present invention, in addition to the fourth characteristic structure, the cover body has a front end side portion and a rear end which are on the front end side in the longitudinal direction of the through hole machine body. A rear end side portion which is a side, the front end side portion and the rear end side portion are connected in a mounted state, the front end side portion and the rear end side portion of the cover body, In the connected state, a groove portion that is continuous along the inner peripheral surface of the cover body and that is recessed radially outwardly has a boundary between the front end side portion and the rear end side portion as viewed in the axial direction. In the configuration that becomes the wall of
When the cover body is attached to the body portion, an annular locking body as the holding means is configured to be interposed in a state of fitting into the groove portion.

  That is, since the cover body is composed of a front end side portion that is the front end side and a rear end side portion that is the rear end side in the longitudinal direction of the through hole machine body, the cover body is attached to the through hole machine body. When the front end side portion of the cover body is inserted from the front end side of the through hole machine body, the rear end side portion is inserted from the rear end side of the through hole body and the front end side portion and the rear end side portion are inserted. Are connected in a mounted state. Thus, in a state where the front end side portion and the rear end side portion of the cover body are connected, the boundary between the front end side portion and the rear end side portion is one wall surface in the axial direction view, and the cover body Since a groove portion that is continuous along the inner peripheral surface and is recessed radially outward is formed, the front end side portion and the rear end side portion are not connected in a state where the front end side portion and the rear end side portion are not connected. It is possible to fit an annular locking body, which will be described later, from the boundary surface side, and in a state where the front end side portion and the rear end side portion are connected, the locking body is fitted into the groove portion and the through-hole machine body It will be in the state where the movement to the axial direction of is suppressed. Therefore, when attaching the cover body to the body portion, it becomes possible to easily fit the annular locking body as the holding means in the groove portion, and after attaching the cover body to the body portion, The locking body is fitted into the groove, and the position of the cover body in the axial direction of the through-hole machine body can be appropriately maintained.

  The sixth feature configuration of the self-propelled through-hole machine according to the present invention is such that, in addition to the fifth feature configuration, the annular locking body is configured to be split into two semicircular portions, and those 2 Each of the two semicircular portions is formed of a magnetic material that can be magnetically attracted to the through-hole body.

  That is, since the annular shape can be maintained by adsorbing the annular locking body configured to be split into two semicircular portions to the through-hole machine body, the cover body is attached to the through-hole body. Sometimes, the locking body is first mounted in an annular shape along the outer periphery of the through-hole machine body, and then the cover body is mounted with the locking body interposed between the through-hole body. be able to. Therefore, for example, a complicated procedure such as fixing the two semicircular portions to each other with an adhesive tape to maintain the annular shape or fixing the two semicircular portions to each other with a fastener or the like becomes unnecessary. When attaching the cover body to the hole machine main body, it is possible to simplify the work of interposing the annular locking body between the through-hole machine main body and the cover body.

Diagram showing the state of use of the self-propelled through-hole machine The figure explaining the composition of a through-hole machine body The figure explaining the relationship between a through-hole machine main body and a cover body The figure explaining the two semicircle parts of a latching body

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a state in which an underground hole 52 is drilled while the through hole body J is moved forward from the start side shaft 50 toward the end side shaft 51.
As shown in FIG. 2, the through-hole machine body J includes a pointed head portion 20 on the front end side of the cylindrical body portion 10 and a bottom wall portion 10T on the rear end side. Yes.
The head portion 20 is provided so as to be movable in and out in the axial direction of the body portion 10 and is urged in the retraction direction by a spring SP.

A piston 10P is provided inside the body portion 10 so as to be slidable and movable along the axial direction of the body portion 10 and can apply an impact force to the head portion 20 or the bottom wall portion 10T.
One end side of a pressurized gas supply hose 10H that supplies pressurized gas that drives the piston 10P to the front end side or the rear end side of the body portion 10 is connected to the rear end side of the through-hole machine body J to supply pressurized gas. The other end of the hose 10H is connected to a compressor K that compresses air and sends it to the pressurized gas supply hose 10H.

The piston 10P is connected to the front end side of the through-hole machine main body J by pressurized gas (specifically, compressed air compressed by the compressor K) supplied from the compressor K through the pressurized gas supply hose 10H. The rear end side of the through hole machine body J is slidably moved so as to apply an impact force.
Although not shown in the drawing regarding the structure for feeding the pressurized gas, the piston is intermittently fed so as to move shockably from the bottom wall side to the head side during forward movement, and the piston is moved from the head side to the bottom wall side during backward movement. It is configured to be intermittently fed so as to move shockingly.
Specifically, when the impact force is applied to the front end side of the through hole body J by the compressed air, the piston 10P strikes the head portion 20 provided so as to be movable in and out of the body portion 10. Then, the head portion 20 is caused to project and move from the body portion 10 to generate a propulsive force toward the front end side of the through hole machine body J. Thereafter, the head portion 20 is retreated to the body portion 10 by the protruding distance by the urging force of the spring SP, and returns to the state before the impact force is applied.
Further, when an impact force is applied to the rear end side of the through hole machine main body J by the compressed air, the piston 10P strikes the bottom wall portion of the body part 10 and the rear end part of the through hole body main body J Generate driving force toward the side.

[Cover body]
A cover body C shown in FIGS. 1 to 3 is detachably configured on the front end side of the through-hole machine main body J.
As shown in FIGS. 1 and 2, the cover body C is composed of a front end side portion 30 that is the front end side and a rear end side portion 31 that is the rear end side in the longitudinal direction of the through hole machine body J, and has a maximum diameter. It is formed in a cylindrical shape having a larger diameter than the diameter of the body portion 10. Further, the front end of the front end side portion 30 is formed as a conical portion 30S having a smaller diameter toward the end portion, and the rear end of the rear end side portion 31 is formed as a conical portion 31S having a smaller diameter toward the end portion. The inner diameter of the conical portion 30S is approximately matched to the outer diameter shape of the head portion 20, and a structure that decreases in diameter toward the tip end side is employed. Therefore, the conical portion 30S (and thus the cover body C) moves forward as the head portion 20 advances. The front end side portion 30 and the rear end side portion 31 are configured to be coupled by screwing.

  A plurality of groove portions 31T along the circumferential direction are provided in a part of the outer peripheral portion of the cover body C excluding the conical portion 31S of the rear end side portion 31. The groove portion 31T has a rectangular shape in a cross-sectional view along the axial direction of the cover body C, and the surface along the radial direction of the cover body C is a surrounding earth and stone with respect to the movement of the cover body C in the axial direction. It acts as a resistance part that generates resistance between the two.

The inner peripheral surface 30N of the conical portion 30S in the front end side portion 30 is formed in a shape along the outer peripheral surface 20G of the head portion 20. Further, the inner peripheral surface of the rear end side portion 31 is formed in a shape along the outer peripheral surface 10G of the body portion 10 over the entire length in the longitudinal direction.
Further, in a state where the front end side portion 30 and the rear end side portion 31 are connected, the groove portion 30M that is continuous along the inner peripheral surface of the cover body C and is recessed radially outwardly is formed in the front end side portion 30 and the rear end portion. A boundary surface with the end side portion 31 (end surface 31M of the rear end side portion 31) is configured to be a wall surface in the axial direction view.
Thus, in a state where the front end side portion 30 and the rear end side portion 31 are not connected, an annular locking body 32 to be described later is fitted from the boundary surface side between the front end side portion 30 and the rear end side portion 31. In the state where the front end side portion 30 and the rear end side portion 31 are connected, the locking body 32 is fitted in the groove 30M, and the locking body 32 is moved toward the cover C axis. Movement will be restricted. That is, the annular locking body 32 functions as a holding means that holds the cover body C in the axial direction with respect to the through-hole machine main body J when the through-hole machine main body J is moved backward in the mounted state of the cover body C. .

[Locking body]
As shown in FIG. 4, the locking body 32 is formed of an annular magnetic body that is configured to be divided into two semicircular portions 32α and 32β. 4A shows a divided state, and FIG. 4B shows an integrated state. In the state of being adsorbed to the through-hole machine body J, the two semicircular portions 32α and 32β are respectively shown. However, as shown in FIG.4 (b), it is comprised so that the cyclic | annular form may be maintained and the latching body 32 may be comprised.
The locking body 32 is configured such that, when fitted to the groove 30M, the front end surface 32K located on the front end side of the cover body C protrudes radially inward and contacts the rear end surface 20K of the head portion 20. ing. As a result, when the through hole machine main body J moves backward, the cover body C is substantially separated from the through hole machine main body J (the body part 10 and the head part 20) via the head part 20 at a predetermined axial position. In other words, the locking body 32 is configured to retreat integrally with the cover body and the through-hole machine body.

[Usage of self-propelled through-hole machine]
Next, the usage mode of the self-propelled through-hole machine according to the present invention will be described.
When using a self-propelled through-hole machine, as shown in FIG. 1, the depth of the underground hole to be drilled should be deeper than the depth from the ground surface at the start and end sides of the underground hole to be drilled. The formed start side shaft 50 and the end side shaft 51 are drilled. At this time, the length in the formation direction of the underground hole 52 of the start side shaft 50 is such that the through hole body J can take an initial posture toward the target end position in the start side shaft 50. The start side shaft 50 is drilled.

[Drilling with a diameter that can be drilled only with the punch body J]
When the diameter of the underground hole 52 to be drilled is a diameter (for example, 65 mm) that can be drilled only by the through-hole machine main body J, the cover shaft C is not attached to the through-hole machine main body J, and Arrange at a predetermined position.
Thereafter, when compressed air is intermittently sent as pressurized gas from the compressor K, the piston 10P moves to the front end side of the body portion 10 and strikes the head portion 20. The head part 20 projects forward from the body part 10 by an impact force and pushes away the earth and stone. Subsequently, the through hole machine main body J automatically exhausts the compressed air, and the head portion 20 moves back to the original position by the urging force of the spring SP. At this time, a space is formed in front of the head portion 20. Then, when compressed air is sent again from the compressor K, the head portion 20 protrudes forward to push the earth and stone, and the trunk portion 10 moves forward by being pulled by the protruding operation, filling the space in front. By repeating the above operation, the through-hole machine main body J propels the underground, and the underground hole 52 is formed.

Next, the case where the through-hole machine main body J reaches the end side vertical shaft 51 will be described.
When the length of the end side shaft 51 in the direction of the underground hole 52 is sufficiently longer than the length of the through hole machine body J in the longitudinal direction, the through hole machine body J is pulled out from the underground hole 52 and the pressurized gas is supplied. Remove the hose 10H and collect the through-hole machine body J. Moreover, the pressurized gas supply hose 10H left in the underground hole 52 can be recovered by being pulled out from the start side shaft 50 side.

When the length of the terminal shaft 51 in the underground hole 52 direction is shorter than the length of the through hole machine body J in the longitudinal direction, the through hole machine body J cannot be pulled out from the underground hole 52. The through hole machine body J is operated so as to move backward in the hole 52. Specifically, the compressed air supply direction is switched to a direction in which the piston 10P strikes the bottom wall portion 10T of the body portion 10 of the through hole body J using a compressed air supply direction switching means (not shown). This switching can be performed near the compressor K on the ground.
When compressed air is sent from the compressor K with the compressed air supply direction switched, the piston 10P strikes the bottom wall 10T, and the through hole machine main body J moves backward toward the start side shaft 50 by the reaction.

[Drilling with the cover body attached to the through-hole machine body J]
When the diameter of the underground hole 52 to be drilled is larger than the diameter that can be drilled only by the through-hole machine body J (for example, 75 mm), as described above, the through-hole machine body J and the cover body C The cover body C is attached to the through-hole machine main body J with the locking body 32 interposed therebetween, and is arranged at a predetermined position of the start side shaft 50.
Thereafter, when compressed air is intermittently sent from the compressor K, the piston 10P moves to the front end side of the body portion 10 and strikes the head portion 20. The head part 20 protrudes forward from the body part 10 by an impact force. Since the outer peripheral surface 20G of the head portion 20 protruding from the body portion 10 is in contact with the inner peripheral surface 30N of the conical portion 30S in the front end side portion 30 of the cover body C, the cover body C is connected to the head portion 20. It integrally protrudes and moves (FIG. 3B). Subsequently, the through hole machine main body J automatically exhausts the compressed air, and the head portion 20 tries to move back to the original position by the urging force of the spring SP. At this time, since the rear end side portion 31 of the cover body C is provided with a plurality of groove portions 31T along the circumferential direction, the movement of the cover body C in the axial direction is suppressed, and the body portion 10 is covered by the cover portion C. The robot moves forward while being attracted to the body C. By repeating the above operation, the cover body C is propelled through the ground in a state where the cover body C moves out and with the head portion 20 of the through hole machine body J, and the underground hole 52 is formed.

Next, the case where the through-hole machine main body J equipped with the cover body C reaches the end side shaft 51 will be described.
When the length of the terminal shaft 51 in the direction of the underground hole 52 is sufficiently longer than the length in the longitudinal direction of the through hole machine main body J, as in the case of the through hole machine main body J without the cover body C attached. The through hole machine main body J is pulled out from the underground hole 52, the pressurized gas supply hose 10H is removed, and the through hole machine main body J is recovered. Moreover, the pressurized gas supply hose 10H left in the underground hole 52 can be recovered by being pulled out from the start side shaft 50 side.

When the length of the terminal shaft 51 in the underground hole 52 direction is shorter than the length of the through hole machine body J in the longitudinal direction, the through hole machine body J cannot be pulled out from the underground hole 52. In order to move backward in the hole 52, the compressed air supply direction is changed in the direction in which the piston 10P strikes the bottom wall portion 10T of the body portion 10 of the through hole body J using a compressed air supply direction switching means (not shown). Switch.
When compressed air is sent from the compressor K with the compressed air supply direction switched, the piston 10P strikes the bottom wall 10T, and the through hole machine main body J moves backward toward the start side shaft 50 by the reaction. At this time, as described above, the through hole machine main body J is in a state where the through hole machine main body J does not fall off from the cover body C by the contact between the front end surface 32K of the locking body 32 and the rear end surface 20K of the head portion. And the cover body C are integrally moved backward and returned to the start side shaft 50 side, and the through-hole machine body J and the cover body C can be recovered.

[Another embodiment]
(1) In the above embodiment, the compressed air is used as the pressurized gas, and the head portion 20 or the bottom wall portion 10T is hit by the piston 10P. However, the present invention is not limited to such a configuration. A gas other than air may be used under pressure, or a fluid such as water or oil may be used. In addition, various configurations can be applied as long as an impact force can be applied to the head portion 20 or the bottom wall portion 10T.

(2) In the above embodiment, a plurality of groove portions 31T along the circumferential direction are provided in a part of the outer peripheral portion of the rear end side portion 31 of the cover body C excluding the conical portion 31S. Although the configuration in which the groove portion 31T acts as the resistance portion is illustrated, the configuration is not limited to such a configuration. For example, the conical portion 30S of the front end side portion 30 and the conical shape of the rear end side portion 31 in the cover body C are used. It is good also as a structure which provides the groove part 31T in the whole outer peripheral part except the part 31S. Moreover, it is good also as a structure provided with several protrusion part instead of several groove part 31T as a resistance part. Alternatively, this type of resistance portion may not be provided.

(3) In the embodiment described above, the outer peripheral surface 20G of the head portion 20 is in a state of being in contact with the inner peripheral surface 30N of the conical portion 30S in the front end side portion 30 of the cover body C. However, instead of such a configuration, the head portion and the cover body C may be fixedly connected by, for example, screwing or bolting. In addition, when comprised in this way, the latching body 32 becomes unnecessary.

(4) In the above embodiment, the locking body 32 is formed of an annular magnetic body that can be divided into two semicircular portions 32α and 32β, and each of the two semicircular portions 32α and 32β is adsorbed to form an annular shape. However, the present invention is not limited to such a configuration. For example, the two semicircular portions 32α and 32β are fixed to each other with an adhesive tape to form an annular shape. It is good also as a structure which hold | maintains each of the two semicircle parts 32 (alpha) and 32 (beta) by a mutually greasy-like member or a wedge-shaped member, and maintains an annular form.

(5) In the above-described embodiment, the head portion 20 is configured to be urged in the direction of retreating to the body portion 10 by the spring SP. However, the configuration is not limited to such a configuration. Various urging methods such as urging using an elastic body or a part of the compressed gas from the compressor K used for projecting and moving the head portion 20 from the body portion 10 can be applied.

(6) In the above embodiment, the front end side portion 30 and the rear end side portion 31 of the cover body C are connected by screwing. However, the present invention is not limited to such a configuration. Various connection mechanisms, such as a configuration in which the front end side portion 30 and the rear end side portion 31 are connected by a connecting member having a shape, can be used.

(7) In the above embodiment, the through hole machine main body J is of a standard capable of drilling a 65 mm underground hole, and the cover body C is capable of drilling a 75 mm underground hole. However, the present invention is not limited to such a form. For example, an underground hole having a diameter of 75 mm or more can be drilled in a standard through-hole machine body J capable of drilling a 65 mm underground hole. It is good also as a structure which can mount | wear with a simple cover body C, and it can also comprise so that several cover bodies C corresponding to the diameter of a required underground hole may be prepared.

  According to the present invention, even when drilling underground holes of different diameters, it is not necessary to prepare a plurality of through-hole machine bodies corresponding to the diameters, and the self-propelled penetration that can realize reduction in equipment costs. It becomes possible to provide a punching machine.

DESCRIPTION OF SYMBOLS 10 Body part 10T Bottom wall part 20 Head part 10P Piston J Through-hole machine main body K Compressor C Cover body 31T Groove part (resistance part)
30 Front end side portion 31 Rear end side portion 32 Locking body 32α, 32β Semicircular portion

Claims (6)

A pointed head portion is provided on the front end side of the cylindrical body portion and a bottom wall portion is provided on the rear end side, and the head portion is provided so as to be movable in and out in the axial direction of the body portion. A piston that is urged in the retraction direction, is slidable along the axial direction inside the body portion, and can impart an impact force to the head portion or the bottom wall portion. It has a through-hole machine body provided,
A pressurized gas for driving the piston to the front end side or the rear end side of the body part is supplied to the through-hole machine body by a compressor, and the piston is moved to the front end side of the body part to move to the head part. Applying an impact force, the head unit moves forward and backward with respect to the body part, and the through-hole machine body moves forward while forming an underground hole, and the piston is moved to the rear end of the body part. A self-propelled through-hole machine configured to move to the side and apply an impact force to the bottom wall portion and to move backward through the underground hole drilled by the through-hole machine body,
A cover body that is formed in a cylindrical shape whose maximum diameter is larger than that of the body portion, and whose front end side and rear end side are formed in a conical shape having a smaller diameter toward the end portion, Removably provided on the front end side,
The cover body is a self-propelled through-hole machine configured to move in and out integrally with the head portion when the through-hole machine body moves forward.   The self-propelled through-hole machine according to claim 1, wherein a resistance portion that generates resistance with surrounding earth and stone with respect to movement of the cover body in the axial direction is provided on an outer peripheral portion of the cover body.   The self-propelled through-hole machine according to claim 2, wherein the resistance portion is a plurality of grooves along the circumferential direction of the cover body. The cover body is formed in a shape in which the inner peripheral surface of the conical portion on the front end side is along the outer peripheral surface of the head part,
The holding means which hold | maintains the said cover body to an axial direction position with respect to the said through-hole machine main body at the time of the backward movement of the through-hole machine main body in the mounting state of the said cover body. The described self-propelled through-hole machine. The cover body is composed of a front end side portion which is a front end side and a rear end side portion which is a rear end side in the longitudinal direction of the through-hole machine body,
The front end side portion and the rear end side portion are configured to be connected in a mounted state,
In a state where the front end side portion and the rear end side portion of the cover body are connected, a groove portion that is continuous along the inner peripheral surface of the cover body and is recessed radially outwardly is formed with the front end side portion. In the configuration where the boundary with the rear end side portion is one wall surface in the axial direction view,
5. The apparatus according to claim 4, wherein when the cover body is mounted on the through-hole machine body, an annular locking body serving as the holding means is interposed in a state of being fitted into the groove portion. Traveling through-hole machine.   The annular locking member is configured to be divided into two semicircular portions, and each of the two semicircular portions is a magnetic material that can be magnetically attracted to the through-hole machine body so as to maintain an annular shape. The self-propelled through-hole machine according to claim 5, which is formed.

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