JP2002346824A - Device for cutting existing pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and easily adjust the unit feed per revolution of a cutting tool holder to a predetermined unit feed per revolution, even though rotational resistance caused at each bearing portion is varied by manufacturing tolerances, errors or the like. SOLUTION: This device is provided with a passive rotor 9 giving corresponding rotation to the unit feed per revolution to a thread-operated feed mechanism D, and also a means E for adjusting slide resistance adjusting the slide resistance between a slidable guide portion 6 and a cutting tool holder 5, by engaging the slidable guide portion 6 guiding a cutting tool holder 5 retaining a cutting tool 2 in the direction of a pipe diameter slidably, a thread-operated feed mechanism D making the cutting tool holder 5 slidable along the said slidable guide portion 6 and an engaging portion 7 provided in a fixing portion next the rotational route of the cutting unit A in the cutting unit A provided with the cutting tool 2 cutting the peripheral wall of an existing pipe along a circumferential direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an existing pipe cutting apparatus which is used, for example, for cutting and removing a part of an existing water pipe in a sealed housing in a water-free state. A cutting unit provided with a cutting tool for cutting the peripheral wall along the circumferential direction, a guide support unit rotatably supporting the cutting unit around the pipe axis, and a driving unit for driving and rotating the cutting unit. The cutting unit, a sliding guide portion for guiding a tool holder for holding the cutting tool slidably in the pipe diameter direction, a screw-type feed mechanism for moving the tool holder along the sliding guide portion, The present invention relates to an existing pipe cutting device in which a screw-type feed mechanism is provided with a passive rotary body that imparts rotation corresponding to a unit feed amount by engagement with an engaging portion provided on a fixed portion beside the rotation path of the cutting unit. .

[0002]

2. Description of the Related Art In a conventional existing pipe cutting apparatus, a sliding guide groove in the form of a dovetail along the pipe diameter direction is formed in a cutting rotating body of a cutting unit rotatably supported by a guide support portion. A moving guide portion is attached, and a bite holder is slidably fitted in a sliding guide groove of the sliding guide portion with a fixed sliding resistance (for example, see Japanese Patent Application Laid-Open No. 11-82859).

[0003]

In the existing pipe cutting apparatus of this type, when the cutting rotary body of the cutting unit is driven and rotated, the passive rotary body provided in the cutting unit is fixed on the side of the rotation path of the cutting unit. It rotates by engaging with the engaging part provided in the part, and the rotation is transmitted to the screw type feed mechanism, and the tool holder is fed by the unit feed amount to the pipe shaft core side along the guide groove of the sliding guide part. However, the rotational resistance at the bearing that rotatably supports the passive rotary body, the rotational resistance at the support of the screw-type feed mechanism, or the rotation transmission system from the passive rotary body to the screw-type feed mechanism If the rotational resistance and the rotational resistance of the cutting rotator of the cutting unit fluctuate due to manufacturing tolerances, errors, etc., the unit feed amount of the tool holder will fluctuate. Unit feed There When fluctuates increasing side, is likely to lead to interruption of the cutting operation by biting damage to the cutting tool.

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and its main problem is that even if the rotational resistance at each bearing portion fluctuates due to manufacturing tolerances or errors, a bite holder is used. An object of the present invention is to provide a useful existing pipe cutting device that can efficiently and easily adjust the unit feed amount to the set unit feed amount.

[0005]

According to a first aspect of the present invention, there is provided a cutting unit having a cutting tool for cutting a peripheral wall of an existing pipe along a circumferential direction, and connecting the cutting unit around a pipe axis. A guide support section that supports the
A drive unit for driving and rotating the cutting unit, wherein the cutting unit includes a sliding guide portion that guides a cutting tool holder that holds the cutting tool so as to be slidable in the pipe diameter direction; Passive rotation that imparts rotation equivalent to the unit feed amount to the screw-type feed mechanism by engagement between the screw-type feed mechanism that slides the tool holder and the engaging part provided on the fixed part beside the rotation path of the cutting unit. An existing pipe cutting device provided with a body, wherein a sliding resistance adjusting means for adjusting a sliding resistance between the sliding guide portion and the tool holder is provided.

[0006] According to the above-mentioned characteristic configuration, the rotational resistance at the support portion rotatably supporting the passive rotary member, the rotational resistance at the support portion of the screw-type feed mechanism, or the rotation resistance from the passive rotary member to the screw-type feed mechanism. Even if the rotational resistance in the rotation transmission system or the rotational resistance of the cutting rotary body of the cutting unit fluctuates due to manufacturing tolerances or errors, etc. The sliding resistance with the tool holder can be suppressed by adjusting the sliding resistance adjusting means.

Therefore, even if the rotational resistance at each bearing part fluctuates due to manufacturing tolerances and errors, the simple operation of adjusting the sliding resistance between the sliding guide part and the tool holder can be performed. Can be easily and efficiently adjusted to the set unit feed amount.

According to a second aspect of the present invention, there is provided an existing pipe cutting apparatus, wherein the sliding resistance adjusting means has a sliding guide surface facing a sliding guide groove of a sliding guide portion and a bite holder opposed thereto. A sliding guide plate interposed between the sliding surface of
The sliding guide plate is configured to include a pressing operation mechanism capable of performing a pressing adjustment operation on the sliding surface side of the tool holder.

According to the above-mentioned feature, the pressing operation mechanism is operated to change the pressing state of the sliding guide plate against the sliding surface of the bite holder, so that the sliding guide portion and the bite holder can slide. Resistance can be easily adjusted, and part of the sliding surface of the tool holder is guided through the sliding guide plate, so that part of the pressing mechanism directly contacts the sliding surface of the tool holder. The sliding of the cutting tool holder can be maintained in a smooth state without performing.

According to a third aspect of the present invention, the existing pipe cutting device is characterized in that the pressing operation mechanism is constituted by pressing operation bolts provided at a plurality of positions in a longitudinal direction of the guide groove of the sliding guide portion. The slide guide plate is provided with a concave portion with which the tip of each pressing operation bolt is engaged.

[0011] According to the above-mentioned feature, the tip of each pressing operation bolt is engaged with the plurality of recesses of the sliding guide plate, so that the sliding guide plate is engaged and held by the sliding guide portion. In addition to stabilizing the sliding of the holder, the structure for this can be manufactured simply and advantageously in terms of manufacturing cost by using the pressing operation bolts constituting the pressing operation mechanism.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIGS.
After cutting and removing a part of the existing pipe 1 such as a water pipe in the sealed housing H, the existing pipe cutting and replacing equipment for attaching the replacement pipe section 13 to a portion corresponding to the cut and removed removing pipe section 12, and 1 shows an existing pipe cutting apparatus of the present invention used in the apparatus.

The existing pipe cutting device is disposed on the left and right sides of the housing H to cut both ends of a portion corresponding to the removal pipe section of the existing pipe 1. As shown in FIG.
Of the joint tube member 16 slidably fitted to the exchange tube portion 13 by an operation from the outside of the existing tube 1 and the exchange tube portion 1.
A feeder mechanism G that slides up to the seam portion 3 is provided. Further, a holding elevating device J that moves up and down while holding the removal pipe section 12 and the exchange pipe section 13 separately is provided at the upper part of the housing H. ing.

As shown in FIGS. 2 to 10, the existing pipe cutting apparatus includes a cutting unit A having a cutting tool 2 for cutting a peripheral wall 1A of an existing pipe 1 along a circumferential direction. And a driving unit C for driving and rotating the sprocket wheel 3 of the cutting unit A. The guide support unit B rotatably supports the sprocket wheel 3 as a cutting rotator around the pipe axis X of the existing pipe 1. At the same time, a sliding part for guiding a tool holder 5 for detachably holding the cutting tool 2 in a radial direction of the existing pipe 1 is provided on a mounting portion K provided on the sprocket wheel 3 of the cutting unit A. A sliding guide portion 6 having a dynamic guide groove 6a, a screw type feed mechanism D for sliding the cutting tool holder 5 along the sliding guide portion 6, and a fixing portion beside the rotation path of the cutting unit A The engagement between the engaging portion 7, and the passive rotary member 9 which imparts rotation equivalent to the unit feeding amount to the feed screw shaft 8 of the screw-type feed mechanism D is provided.

Further, the rotation transmission system from the passive rotating body 9 to the feed screw shaft 8 of the screw type feed mechanism D, that is, between the passive rotating body 9 and the feed screw shaft 8, the rotation of the passive rotating body 9 A worm 42 provided on the transmission shaft 11;
A speed reduction mechanism 10 comprising a worm wheel 41 provided on a feed screw shaft 8 of a screw type feed mechanism D is interposed in a state in which the sliding guide portion 6 and the bite holder 5 slide. Is provided with a sliding resistance adjusting means E for adjusting the sliding resistance.

As shown in FIGS. 1 to 4, the housing H has a lower housing 14 having an upward opening and hermetically surrounding a portion corresponding to a removal pipe portion of the existing pipe 1 and an opening / closing opening of the lower housing 14. An upper housing 1 which is detachably mounted in a sealed state via an operable operation gate valve F.
Further, the lower housing 14 includes a first cover member 14A positioned above the existing pipe 1 and a second cover positioned below the existing pipe 1 in order to sandwich the existing pipe 1 from above and below. The cover member 14B is formed in two parts, and a semicircular notch that exposes a pair of through holes 24 through which the existing pipe 1 penetrates is provided at a connection portion of each of the cover members 14A and 14B. A portion 24A is formed.

Each of the through holes 24 in the lower housing 14
Each of the annular gaps formed between the outer pipe 1 and the outer peripheral surface of the peripheral wall 1A of the existing pipe 1 is configured to be closed by a closing ring 25 externally fitted to the existing pipe 1. The cylindrical portion 25A of the ring 25 is externally fitted and fixed to the outer peripheral surface of the peripheral wall 1A of the existing pipe 1 via the first packing 26, and the flange portion 25B of the closing ring 25 is connected to the lower housing 14 via the second packing 27. Is fixedly connected to the outer surface of the side wall.

Further, on the inner peripheral surface of the closing ring 25,
A tapered surface having a larger diameter toward the opening side is formed, and between the tapered surface and the outer peripheral surface of the peripheral wall 1A of the existing pipe 1, the existing pipe 1 and the closing ring 25 are adjusted to be coaxial. Ring 28 having a tapered surface for insertion. The closing ring 25 and the centering ring 28 are used to sandwich the existing pipe 1 from above and below.
Each is formed in two in the circumferential direction.

As shown in FIGS. 1 to 4, the guide support portion B includes a cylindrical pedestal 29 which is bolted and fixed to the inner surface of the side wall of the lower housing 14 together with the flange portion 25 B of the closing ring 25. And a ring-shaped guide disk 30 that is concentrically fixed to the free end side of the cutting unit A and guides the sprocket wheel 3 of the cutting unit A in a fitted state so as to be relatively rotatable around the pipe axis X of the existing pipe 1. And a through hole 31 formed in the center of the guide disc 30
The existing pipe 1 is configured to pass through the through hole 32 of the pedestal 29.

On one side of the sprocket wheel 3, there is formed a recess 33 for fitting the guide disc 30 of the guide support portion B from the direction of the tube axis X, and the opening of the recess 33 is formed. A contact piece 36 for preventing the sprocket wheel 3 fitted and mounted by contact with the guide disk 30 from being pulled out is attached to the outer peripheral portion. Further, a concave portion 33 of the sprocket wheel 3 and the contact piece 36 and the guide are provided. A low friction material 37 made of a synthetic resin or the like for reducing frictional resistance is interposed between the sliding surfaces facing the disk 30.

The guide support B and the cutting unit A
Because the sprocket wheel 3 is assembled to the existing pipe 1 from the outside in the pipe diameter direction, the guide support portion B is composed of a pair of divided guide support portions formed in two in the pipe diameter direction. The sprocket wheel 3 is composed of a pair of split sprocket wheels 3A divided into two in the radial direction of the tube.

As shown in FIGS. 3 to 8, the mounting portion K mounted on one of the split sprocket wheels 3A has at least the feed screw shaft 8 of the screw type feed mechanism D in a state where the mounting portion K also serves as a sliding guide portion. And a second mounting portion 4 for rotatably supporting the rotary transmission shaft 11. The first mounting portion 6 and the second mounting portion 4 are rotatable. First fixedly connecting
The fixing means 17 is provided with flexibility to allow the relative movement of the mounting portions 4 and 6 in the connection surface direction within a certain range.
The two mounting portions 4, which are fixedly connected by the first fixing means 17,
There is provided a second fixing means 18 for fixing and connecting the mounting portions 4 and 6 while maintaining the relative positional relationship of the fixing portions 6.

The first mounting portion 6 includes a mounting base 6A having a dovetail-shaped sliding guide groove 6a for guiding the tool holder 5 slidably in the pipe diameter direction, and a second mounting portion 4.
Plate-shaped third bracket 6 having a mounting surface 6b for
B and a screw-type fourth fixing means 39 for fixing and connecting one end of the mounting base material 6A to the third bracket 6B.

Fifth fastening bolts for fixing the mounting substrate 6A to the split sprocket wheel are provided at a plurality of locations (two locations in this embodiment) of the mounting flange portions 6c formed on the left and right sides of the mounting substrate 6A. (An example of a screw-type fifth fixing means) An insertion hole 6d for 40 is formed, and one end of the mounting base 6A in the guide groove longitudinal direction and a plurality of locations of the third bracket 6B (6 locations in this embodiment). ), A screw hole 6e and an insertion hole 6f for the fourth fastening bolt constituting the fourth fixing means 39 are formed,
Further, the third bracket 6B has a bearing hole 6 for rotatably supporting the intermediate shaft portion 8a of the feed screw shaft 8 in a penetrating state.
g and a recess 6h into which a part of the worm 42 supported by the second mounting portion 4 enters.

An L-shaped main bracket 4A having a first bearing hole 4a for rotatably supporting one end of the rotary transmission shaft 11 so that the second mounting portion 4 penetrates one end of the rotary transmission shaft 11; And a plate-shaped sub-bracket 4B having a second bearing hole 4b for rotatably supporting the other end of the bracket 4A in a penetrating state.
A screw-type third fixing means 38 for fixing and connecting B is provided.

The main bracket 4A and the third bracket 6B oppose each other at a plurality of opposing positions (two positions in this embodiment) of the first fixing means 17 with the insertion holes 4c for the first fastening bolts. A screw hole 6m is formed, of which an annular gap formed between the inner peripheral surface of the insertion hole 4c of the main bracket 4A and the outer peripheral surface of the first fastening bolt 17 connects the mounting portions 4 and 6 together. The above-mentioned accommodation that allows relative movement in a plane direction within a certain range is configured.

Therefore, the worm 42 and the worm wheel 41 constituting the speed reduction mechanism 10 are separately mounted on the first mounting portion 6 and the second mounting portion 4 of the split mounting portion K, respectively. By fixing and connecting the portions 6 and 4 with the first fastening bolts of the first fixing means 17 having flexibility, the engagement between the worm 42 and the worm wheel 41 due to a manufacturing error, an assembly error, or the like is prevented. Even in the case of occurrence, the worm 42 and the worm wheel 41 are moved by the relative movement or relative movement of the mounting portions 6 and 4 along the direction of the mounting surface 6b within the range of the allowance provided in the first fixing means 17. The meshing condition can be corrected naturally or artificially.

The second fixing means 18 is shown in FIGS.
As shown in (b), a plurality of opposing portions (two in this embodiment) of the main body portion of the main bracket 4A and the third bracket 6B fixedly connected by the first fastening bolts 17 are drilled and tapered reamer. Post-processed tapered hole 18
a and a taper pin 18b that is dropped into and fixed to each taper hole 18a.

After the main body of the main bracket 4A and the third bracket 6B are fixedly connected by the first fastening bolt 17 of the first fixing means, each of the four brackets 4A and 6B is formed by post-processing. By dropping and fixing the tapered pin 18b into the tapered hole 18a, the first and second fixing means 17 can be firmly fixed and connected while maintaining the relative positional relationship between the two 4A and 6B corrected by the flexibility.
Even when an external force such as a driving force or a cutting reaction force acts, the worm 42
And the worm wheel 41 can be maintained in a corrected and favorable state.

Further, as shown in FIG. 6, a third fixing means 3 is provided at a plurality of opposing positions (two positions in the present embodiment) of the main body portion of the main bracket 4A and the sub bracket 4B.
A screw hole 4f and an insertion hole 4e are formed for the third fastening bolts that make up the 8th embodiment.

As shown in FIGS. 2, 6 and 7, the third bracket 6B of the first mounting portion 6 and the main bracket 4A of the second mounting portion 4 oppose each other, that is,
The one end in the longitudinal direction of the third bracket 6B and the end of the main body of the main bracket 4A orthogonal to the third bracket 6B are separately abutted from two directions orthogonal to each other to restrict the relative rotation of the two 6B and 4A. The position restricting portions 6j and 4g are integrally formed so as to protrude.

That is, the position restricting portion 6j on the third bracket 6B side contacts the end surface of the main bracket 4A from the direction along the width direction of the sliding guide groove 6a as shown in FIG. The position restricting portion 4g on the side of the bracket 4A is configured to contact the end face of the third bracket 6B from a direction along the axis of the rotary transmission shaft 11.

As shown in FIGS. 7 and 9, the tool holder 5 slides along a slide guide groove 6a of a mounting base 6A constituting a first mounting portion (sliding guide portion) 6, as shown in FIGS. A mounting groove 5 for detachably holding the sliding portion 5a having a trapezoidal cross section and the cutting tool 2 in a state in which the cutting tool 2 cannot be relatively moved (in an integrated state).
b, through-hole 5c into which male screw portion 8b of feed screw shaft 8 enters
Are formed, and in the through hole 5c,
A screw cylinder shaft 5A screwed with the male screw portion 8b of the feed screw shaft 8 is fixed with screws or the like. Further, the tool holder 5 has a plurality of bolts 5B for fixing the cutting tool 2 mounted in the mounting groove 5b. It is screwed.

As shown in FIG. 7, the worm wheel 41 cannot be rotated relative to the shaft of the feed screw shaft 8 via a key on the shaft protruding from the bearing hole 6g of the third bracket 6B (integrally). After the outer screw is attached to the feed screw shaft 8 and the worm wheel 41, the feed screw shaft 8 and the worm wheel 41
The bracket 6B is rotatably supported relative to the bracket 6B.

As shown in FIG. 8, a flange 11a which comes into contact with the periphery of the first bearing hole 4a of the main bracket 4A, and a rotation applying tool such as a power tool or a spanner are provided at one end of the rotary transmission shaft 11. And an operation engaging portion 11b for performing a rotation operation is formed at an intermediate portion of the rotation transmission shaft 11.
A worm 42 and a star wheel, which is an example of the passive rotating body 9, are externally fitted via a key in a state where they cannot rotate relative to each other (in an integrally rotating state). A washer 54 and a bolt 55 are provided across and the sub-bracket 4B for detachably mounting the rotation transmission shaft 11 only for rotation.

When checking the sliding state of the cutting tool holder 5 or returning the cutting tool 2 to the initial position (set cutting start position), the operating tool formed at the end of the rotary transmission shaft 11 is used. By engaging the rotation imparting tool with the engaging portion 11b, the rotation transmission shaft 11 can be rotated quickly and easily via the rotation imparting tool. Workability can be improved.

The sliding resistance adjusting means E is shown in FIGS.
As shown in FIG. 9, a pair of inclined sliding guide surfaces 6k facing the sliding guide grooves 6a of the metal mounting base material 6A constituting the first mounting portion (sliding guide portion) 6, and A metal sliding guide plate 60 is interposed on one side between the two sliding surfaces 5d of the metal bite holder 5 opposed to each other in the guide groove width direction, and a plurality of longitudinal guide grooves of the mounting base 6A are provided. Screw holes 6n communicating with the intervening space of the sliding guide plate 60 in the guide groove width direction are formed at locations (two locations in the embodiment), and the sliding guide plate 60 is formed in each screw hole 6n.
The pressing operation bolt 61 which is an example of a pressing operation mechanism capable of performing a pressing adjustment operation is screwed into the sliding surface 5d of the bite holder 5 from the guide groove width direction.

Then, the rotation resistance at the bearing for rotatably supporting the star wheel 9 and the rotation resistance at the bearing of the screw type feed mechanism D, or the rotation transmission system from the star wheel 9 to the screw type feed mechanism D Resistance at cutting, cutting unit A
Even if the rotational resistance of the sprocket wheel 3 fluctuates due to manufacturing tolerances, errors, etc., the fluctuation of the unit feed amount of the bite holder 5 due to this fluctuation is determined by the sliding resistance between the mounting base 6A and the bite holder 5. It can be suppressed by adjusting the pressing operation bolt 61 of the sliding resistance adjusting means E, and a part of the sliding surface 5d of the tool holder 5 is guided through the sliding guide plate 60. The tip of the pressing operation bolt 61 does not directly contact the sliding surface 5d of the tool holder 5, and the sliding of the tool holder 5 can be maintained in a smooth state.

Further, a lock nut 62 is provided on each pressing operation bolt 61, and the sliding guide plate 60
A concave portion 60a with which the tip of each pressing operation bolt 61 is engaged is formed. Then, each recess 60 of the sliding guide plate 60
The sliding guide plate 60 is engaged and held on the side of the mounting base material 6A by engaging the distal end portion of the pressing operation bolt 61 with “a”, so that the sliding of the tool holder 5 is stabilized.

As shown in FIGS. 3 and 4, the driving section C includes an electric motor 44 mounted on an outer surface of a side wall of the lower housing 14, and a lower housing which is operatively connected to an output shaft of the electric motor 44. Output shaft 45 rushing into 14
And a driving sprocket 46 fixed to the end of the output shaft 45 and the sprocket wheel 3 of the cutting unit A.
And an endless chain 47 wound around the endless chain.

As shown in FIG. 10, a plurality of (five in this embodiment) protruding pieces 9A are radially formed on the star wheel 9 at equal intervals in the circumferential direction.

As shown in FIGS. 2 to 4 and FIG. 10, the engaging portion 7 is located near the rotation path of the sprocket wheel 3 of the cutting unit A and on the inner surface of the side wall of the lower housing 14 as a fixing portion. A pair of plate pieces 48 arranged close to each other along the rotation direction of the sprocket wheel 3 is attached to a pedestal 49 fixed to a specific location by bolts. A is arranged so as to sequentially engage with the protruding piece 9A of the star wheel 9 as the A rotates.

When one protruding piece 9A of the star wheel 9 engages with the first plate piece 48A on the upper side in the rotation direction with the driving rotation of the cutting unit A, the protruding piece 9A and the first plate piece 48A However, the star wheel 9 is rotated to the normal rotation side until the engagement is released by their relative movement, and the subsequent protruding piece 9A of one protruding piece 9A is rotated to the second plate piece 48B on the lower side in the rotation direction. Star wheel 9 until it engages
After the rotation of the star wheel 9 is stopped and the succeeding protruding piece 9A and the second plate piece 48B are engaged, the star wheel 9 rotates to the normal rotation again until the engagement is released by their relative movement. .

The angular velocity of the star wheel 9 during forward rotation is reduced via the worm 42 and the worm wheel 41, and the external thread 8b of the feed screw shaft 8 rotates at an angular velocity lower than the angular velocity of the star wheel 9. While rotating by a predetermined angle with respect to the screw cylinder shaft 5A of the bite holder 5, the bite holder 5 moves toward the pipe axis X of the existing pipe 1 along the sliding guide groove 6a, and the cutting bite 2 moves therewith. Moves to the pipe axis X side of the existing pipe 1.

The sum of the two movements of the bite holder 5 toward the tube axis X when the star wheel 9 rotates twice forward while sequentially engaging with both plate pieces 48 of the engagement portion 7. But,
This corresponds to the unit feed amount of the bite holder 5 of the screw type feed mechanism D.

As shown in FIG. 11, the feeder mechanism G includes an operated arm 19 connected to the joint tubular member 16 and
A feed screw shaft 20 which is screwed into a screw hole provided in the operated arm 19, a stopper plate 21 fixedly connected to the exchange pipe portion 13 in a state capable of contacting one end of the feed screw shaft 20, and A rotary operating body 22 for engaging the other end of the feed screw shaft 20 and rotating the same, and the rotary operating body 22 is provided on a side wall of the lower housing 14. The guide shaft 23 is reciprocally movable and rotatably held with its distal end projecting to the outside, and an angular shaft formed at a portion of the rotating operation body 22 projecting to the outside. By rotating the portion, the joint tubular member 16 of the replacement pipe portion 13 attached to a portion corresponding to the removal pipe portion in place of the resection tube portion 12 is slid to the joint portion between the existing pipe 1 and the replacement pipe portion 13. be able to.

When the joint tubular member 16 is fixed in a state of straddling the existing pipe 1 and the exchange pipe section 13, the inner peripheral surface of the joint tubular member 16 and the outer peripheral faces of the existing pipe 1 and the exchange pipe section 13 are fixed. Is formed between the inner peripheral surface of the joint tubular member 16 and the outer peripheral surface of the existing pipe 1 by an elastic sealing material 16A.
And an elastic sealing material 16B interposed between the inner peripheral surface of the joint tubular member 16 and the outer peripheral surface of the exchange pipe portion 13, so that the external sealing can be achieved.

Next, the working steps of the existing pipe cutting and replacing equipment configured as described above will be described. As shown in FIG.
A pit for mounting the housing H is excavated at a specific location of the existing pipe 1 buried underground, and, for example, the existing pipe 1 including the gate valve 50 to be replaced is exposed. In this case, the gate valve 50 and a part of the existing pipe 1 connected to the gate valve 50 correspond to the removal pipe section 12.

Next, as shown in FIGS. 1, 3, and 13,
The first cover member 14A and the second cover member 14B of the lower housing 14 are attached to the existing pipe 1 in a state in which a portion corresponding to the removal pipe portion of the existing pipe 1 is jacketed.
The closing ring 25 is mounted over the lower housing 14 and the centering of the closing ring 25 with respect to the existing pipe 1 by the centering ring 28.

The two sets of guide support portions B and the cutting unit A are assembled to the lower housing 14 so that the cutting bit 2 of the cutting unit A is located at a predetermined cutting position with respect to the peripheral wall 1A of the existing pipe 1. With the electric motor 44
The endless chain 47 is wound around the drive sprocket 46 of the cutting unit A and the sprocket wheel 3 of the cutting unit A.

As shown in FIG. 13, the lifting rod 57 of the holding / elevating device J provided in the upper housing 15 is lowered to hold the removal pipe portion 12 before cutting by the holding attachment 58, and then the lower housing 14 The inside of the housing H is sealed by sealingly mounting the upper housing 15 in the opening.

The cutting unit A is driven by the electric motor 44.
To rotate the cutting tool 2 in the circumferential direction of the peripheral wall 1 </ b> A of the existing pipe 1, and the engaging part 7 and the passive rotating body 9, that is, the pair of plate pieces 48 and the star wheel 9. The forward rotation of the star wheel 9 due to the engagement with the protruding piece 9A causes the speed reduction mechanism 10 to feed the feed screw shaft 8 of the screw type feed mechanism D.
The cutting tool 2 is fed to the peripheral wall 1A side of the existing pipe 1 while being rotated at a reduced speed to the normal rotation side, and cuts the removal pipe section 12.

At this time, when the water flowing out of the cut portion of the existing pipe 1 fills the housing H, no further outflow occurs.
Water distribution through the existing pipe 1 is maintained. That is, the removal pipe section 12 can be cut in a water-free state.

After the cutting unit 12 has been cut by the cutting tool 2, the cutting unit A is driven in reverse by the electric motor 44 to cut the cutting tool 2 into the peripheral wall 1 A of the existing pipe 1.
Of the screw type feed mechanism D by the speed reduction mechanism 10 by the reversal of the star wheel 9 caused by the engagement of the pair of plate pieces 48 and the projecting piece 9A of the star wheel 9 in the circumferential direction of the star wheel 9. The cutting tool 2 is moved back while rotating the shaft 8 to the reverse rotation side, and the cutting tool 2 is moved to the existing pipe 1.
Is moved away from the peripheral wall 1 </ b> A of the existing pipe 1 to a position where it does not come into contact with the joint tubular member 16 that is slid to the joint between the pipe and the exchange pipe 13.

As shown in FIG. 14, the elevating rod 57 of the holding / elevating device J is raised until the removing tube portion 12 is located in the inner region of the upper housing 15, and the work provided on the upper portion of the lower housing 14 is operated. By closing the gate valve F, the lower housing 14 is moved relative to the upper housing 15.
Then, the upper housing 15 is removed from the lower housing 14. In this state, even when the upper housing 15 is removed from the lower housing 14, the flow of water in the existing pipe 1 is maintained. That is, the uninterrupted water state can be continued.

After the upper housing 15 is opened and the removal pipe 12 held by the holding attachment 58 is removed, a new gate valve 50 is attached to the holding attachment 58.
And an exchange pipe part 13 provided with a joint tubular member 16 at both ends thereof, and again, as shown in FIG. 15, the upper housing 15 is hermetically mounted in the opening of the lower housing 14, and the working gate valve F is The opening operation is performed to communicate the upper housing 15 and the lower housing 14.

Then, as shown in FIGS. 15 and 16, the elevating rod 57 of the holding elevating device J is lowered, and the exchange pipe portion 13 held by the holding attachment 58 is connected to the existing pipe 1.
The joint cylinder member 16 is slid to the joint between the existing pipe 1 and the exchange pipe section 13 by operating the feeder mechanism G from the outside of the housing H.

After removing the upper housing 15 from the lower housing 14, the existing pipe cutting device A is disassembled and the lower housing 14 is removed from the existing pipe 1.
By the above work process, the replacement of a part of the existing pipe 1
The process is completed without obstructing the flow of the fluid in the existing pipe 1, here, tap water.

[Other Embodiments] In the first embodiment described above, when the cutting unit A is rotatably supported around the tube axis X, the guide support portion B and the electric motor 44 of the drive portion C are both connected to the lower housing. 14
Although the existing pipe cutting device fixed to the above has been described, the existing pipe cutting device is not limited to this, and the driving unit C may be provided in the holding elevating device J.

The screw type feed mechanism D is not limited to the configuration described in each of the above embodiments.
A rotary transmission system from the passive rotating body 9 to the screw shaft 8 of the screw-type feed mechanism D has a reduction mechanism 10 interposed therebetween, and the cutting tool 2 can be moved in the pipe diameter direction by the rotation of the passive rotating body 9. If so, the structure can be appropriately changed.

The speed reduction mechanism 10 is not limited to the combination of the worm 42 and the worm wheel 41, but may be, for example, a combination of a small-diameter bevel gear and a large-diameter bevel gear, or a small-diameter sprocket wheel and a large-diameter sprocket wheel. A combination of a sprocket wheel having a diameter and an endless chain wound around the two sprocket wheels, or a combination of a pulley having a small diameter and a large diameter pulley and an endless belt wound around the two pulleys may be employed.

In the above-described first embodiment, the sliding resistance adjusting means E is provided with the inclined sliding guide surface 6 k facing the sliding guide groove 6 a of the sliding guide portion 6 and the sliding of the bite holder 5 opposed thereto. Sliding guide plate 60 interposed between moving surface 5d
And the sliding guide plate 60 is connected to the sliding surface 5 d of the bite holder 5.
Although the pressure adjusting mechanism 61 is configured so as to be capable of freely adjusting the pressure, the present invention is not limited to this configuration, and any mechanism capable of adjusting the sliding resistance between the sliding guide portion 6 and the bite holder 5 can be used. The sliding resistance adjusting means E may have any structure.

In the above-described first embodiment, the engagement portion 7 in which the pair of plate pieces 48 are arranged close to each other along the rotation direction of the sprocket wheel 3 has been described. However, depending on the conditions such as the material of the existing pipe 1, Alternatively, only one plate piece may be provided, and three or more plate pieces may be provided.

In each of the above-described embodiments, after a part of the existing pipe 1 is cut and removed in the sealed housing H, the exchange pipe part 1 is provided at a position corresponding to the cut and removed pipe part 12.
Although the existing pipe cutting device used in the existing pipe cutting and replacing equipment for mounting 3 has been described, the existing pipe cutting device of the present invention is limited to a device that cuts and removes a part of the existing pipe 1 in the sealed housing H. It is not something to be done.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of an existing pipe cutting apparatus of the present invention, and is a front sectional view of an existing pipe cutting and replacing facility.

FIG. 2 is a side sectional view of a main part of an existing pipe cutting and replacing facility.

FIG. 3 is an enlarged front sectional view of a main part before a cutting step.

FIG. 4 is an enlarged front sectional view of a main part at the end of cutting.

FIG. 5 is an enlarged view of a star wheel side of the cutting unit.

FIG. 6 is a partially cutaway front view of a main part of the cutting unit.

FIG. 7 is an expanded sectional view of a main part of the cutting unit.

8A is a partially cutaway plan view showing a fixed connection state by the first fixing means. FIG. 8B is a plan view showing a fixed connection state by the second fixing means.

FIG. 9 is an enlarged cross-sectional view of a mounting part and a main part of a screw-type feed mechanism.

FIG. 10 is an enlarged side view of an engagement portion and a star wheel.

FIG. 11 is an enlarged front sectional view showing a feeder mechanism.

FIG. 12 is a schematic view showing a process of replacing an existing pipe by the existing pipe cutting and replacing equipment.

FIG. 13 is a schematic diagram showing a work process of replacing an existing pipe by the existing pipe cutting and replacing equipment.

FIG. 14 is a schematic view showing a process of replacing an existing pipe by the existing pipe cutting and replacing equipment.

FIG. 15 is a schematic view showing a process of replacing an existing pipe by the existing pipe cutting and replacing equipment.

FIG. 16 is a schematic diagram showing a process of replacing an existing pipe by the existing pipe cutting and replacing equipment.

[Explanation of symbols]

 Reference Signs List A Cutting unit B Guide support part C Drive part D Screw feed mechanism E Sliding resistance adjusting means X Pipe shaft 1 Existing pipe 1A Peripheral wall 2 Cutting bite 5 Tool holder 5d Sliding surface 6 Sliding guide part (first mounting part) 6a sliding guide groove 6k sliding guide surface 7 engaging portion 9 passive rotating body (star wheel) 60 sliding guide plate 60a concave portion 61 pressing operation mechanism (pressing operation bolt)

Claims (3)

[Claims] 1. A cutting unit provided with a cutting tool for cutting a peripheral wall of an existing pipe in a circumferential direction, a guide support section rotatably supporting the cutting unit around a pipe axis, and driving the cutting unit. A driving unit for rotating the cutting unit, wherein the cutting unit includes a sliding guide portion for guiding a tool holder for holding the cutting tool so as to be slidable in the pipe diameter direction, and sliding the tool holder along the sliding guide portion. A screw type feed mechanism to be moved, and a passive rotating body that applies rotation corresponding to a unit feed amount to the screw type feed mechanism by engagement with an engaging part provided on a fixed part beside the rotation path of the cutting unit. An existing pipe cutting device, comprising: a sliding resistance adjusting means for adjusting a sliding resistance between the sliding guide portion and a tool holder. 2. A sliding guide plate wherein said sliding resistance adjusting means is interposed between a sliding guide surface facing a sliding guide groove of a sliding guide portion and a sliding surface of a bite holder opposed thereto. 2. The existing pipe cutting device according to claim 1, further comprising: a pressing operation mechanism capable of adjusting and pressing the sliding guide plate on the sliding surface side of the cutting tool holder. 3. The pressing operation mechanism is constituted by pressing operation bolts provided at a plurality of positions in the longitudinal direction of the guide groove of the sliding guide portion, and the sliding guide plate has a tip of each pressing operation bolt. The existing pipe cutting device according to claim 1 or 2, wherein a concave portion with which the groove engages is formed.