JP3944441B2 - Pipe cutting machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pipe cutting machine that is mounted on a pipe having a relatively large diameter and can cut the pipe by a field work, and more particularly, to an ignition prevention mechanism at the time of cutting for a pipeline of a flammable fluid.
[0002]
[Prior art]
As a device for cutting a pipe used for a gas pipe or a water pipe, a structure for cutting with a cutting tool moving in the circumferential direction on the pipe peripheral surface (for example, Patent Document 1), a structure capable of cutting with a saw tooth (for example, Patent Document 2). In addition to these configurations, cutting may be performed by operating a cutter such as a saw blade by human power.
[0003]
In the configuration as shown in Patent Document 1, the support mechanism for moving the cutting tool in the circumferential direction becomes large, and since it is a cutting tool, it is subject to various loads of moving force and cutting force. As a result, the driving force is required, and as a result, the size of the apparatus cannot be denied, and installation labor, installation and removal time tend to be great, and the price of the apparatus itself is high.
Unlike the case of Patent Document 1, the configuration as shown in Patent Document 2 is only a reciprocating movement of the saw blade, so that the configuration is relatively simple, but the cutting time tends to be long. Therefore, it is conceivable to increase the reciprocating speed of the saw blade in order to shorten the cutting time, in other words, the cutting work time, but in this case, an adverse effect due to heat generation appears.
As a configuration to improve the problems in each configuration described above, a drive unit provided with a rotary cutter is provided in a chain provided with a roller movable in the circumferential direction while being mounted on the peripheral surface of the pipe, and this drive unit is arranged in the circumferential direction. The present applicant has proposed a configuration (for example, Patent Document 3) in which the rotary cutter rolls on the peripheral surface by moving the rotary cutter to the peripheral surface.
[0004]
[Patent Document 1]
JP 2001-162432 A ("0010" column, FIG. 2)
[Patent Document 2]
JP 2002-79481 A ("0015" column, FIG. 1)
[Patent Document 3]
JP-A-8-25127 ("0027" column, "0028" column, FIG. 3)
[0005]
[Problems to be solved by the invention]
By the way, when the pipe is cut using the configuration shown in the above publication, the active gas present in the pipe by the spark when the temperature rises to a temperature at which the spark is generated by the frictional heat generated between the blades, for example, In the case of gas pipes, there is a risk of gas ignition. In particular, in the case of a metal pipe, if the blade is operated at a high speed for the purpose of shortening the working time, the amount of heat generation increases accordingly, and there is a possibility of causing the worst situation such as explosion due to ignition.
In view of this, conventionally, a configuration has been proposed in which an inert gas is supplied to the peripheral portion of the cut portion (for example, Patent Document 3 described above).
However, the inert gas only deactivates the gas that leaks from the cutting position of the pipe and cannot suppress heat generation due to friction, and if this causes a situation where the inert gas is not satisfied, the risk of ignition still remains. Will remain.
[0006]
An object of the present invention is to provide a pipe cutting machine having a configuration capable of reliably preventing the risk of ignition due to frictional heat in view of the problems in the conventional pipe cutting machine.
[0007]
The invention according to claim 1 is a pipe cutting machine provided with a cutting machine main body for rotating the cutter while rotating around the outer periphery of the pipe to be cut to sequentially cut the pipe to be cut over the entire circumference. A cutting portion in the pipe, a blade portion of the cutter that cuts the portion, and a structure for supplying cooling liquid to the cutter surface other than the portion, and the cutter is a fluid that flows in the pipe at the cutting portion of the pipe It is characterized in that it is stopped when a leak is detected .
[0008]
According to a second aspect of the present invention, in addition to the first aspect of the invention, the cooling liquid is attached to a cover member that covers the cutter and has a peripheral edge facing the outer peripheral surface of the pipe to be cut. The cooling liquid supplied by a liquid supply means having a nozzle and supplied to a portion other than the cutting portion is supplied in a state of being applied to the side surface of the cutter.
[0009]
According to a third aspect of the present invention, in addition to the first or second aspect of the present invention, the amount of the cooling liquid to be supplied and at least the supply amount of the supply position are changed according to the amount of frictional heat generated in the cutter. It is characterized by.
[0010]
According to a fourth aspect of the present invention, in addition to the first aspect of the present invention, the cutter is configured to be stopped when the supply of the cooling liquid is stopped. It is characterized by that.
[0011]
The invention described in claim 5 is characterized in that, in addition to the invention described in claim 3, the supply amount of the cooling liquid can be changed at the start of cutting by the cutter and at other times.
[0012]
According to a sixth aspect of the present invention, in addition to the first aspect of the present invention, the cooling liquid supply position includes a blade portion and other than that with the cutter interposed therebetween. Any one of both sides or one side of each position, the blade portion of the cutter, and a position that can be supplied collectively to other positions can be selected.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a main part of a pipe cutting machine main body 1. The configuration shown in FIG. 1 is based on the configuration described in Patent Document 3 filed earlier by the present applicant.
In FIG. 1, a pipe cutting machine main body 1 is mainly composed of a cutting machine main body 1, a support arm 2, a belt-type self-propelled device 3, a roller-equipped chain 4 and the like mounted along the outer peripheral surface of the pipe P to be cut. Therefore, rotational power is transmitted to the cutting machine body 1 through a power transmission tube 5 from a drive engine or a hydraulic pump (not shown) installed near the pipe P to be cut.
[0015]
The cutting machine body 1 has a centrifugal clutch capable of interrupting the rotational power input through the flexible shaft in the power transmission tube 5 at the time of overload, and a speed reduction mechanism for reducing the rotational power input through the centrifugal clutch. As shown in FIG. 2, a cutter rotating shaft 1b and a wheel driving shaft 1c that are driven at a reduced speed via a speed reducing mechanism protrude from the casing 1a.
[0016]
The cutter rotating shaft 1b is located behind the cutting machine body 1 in the moving direction (lower side in FIG. 2) and protrudes from a boss 1d on one side (right side in FIG. 2) of the casing 1a. A disk-shaped diamond cutter 6 is detachably fixed to the disk. Further, the wheel drive shaft 1c is located on the front side of the cutting machine body 1 in the traveling direction (upper side in FIG. 2) and protrudes on both sides of the casing 1a, and V pulleys 3a and 3a as drive wheels are fixed to both ends thereof. Has been.
[0017]
The support arm 2 is disposed on both the left and right sides of the casing 1a of the cutting machine main body 1 and has one end pivotably mounted around the wheel drive shaft 1c and the other end rearward in the traveling direction of the cutting machine main body 1. It is a pair of left and right facing (lower side in FIG. 2), and the shape of the side faces a semicircular arc shape bulging upward and straddles the boss 1d of the casing 1a (see FIG. 1). The other ends of the pair of left and right support arms 2 and 2 are connected to each other via a connecting shaft 7. The connecting shaft 7 has a pair of left and right rolling wheels 8 that roll on the outer peripheral surface of the pipe P to be cut. 8 and a chain connection fitting 9 are mounted.
[0018]
The chain connecting bracket 9 is obtained by connecting the other end portions of a pair of left and right connecting arms 9a, 9a, one end of which is pivotally attached to the connecting shaft 7, by two connecting shafts 9b, 9c. A pair of left and right rolling wheels 9d, 9d capable of rolling on the outer peripheral surface of the pipe P to be cut is mounted on 9b, and similar rolling wheels 9e, 9e are mounted on the connecting shaft 9c.
[0019]
Here, in the cutting machine body 1, the cutter rotating shaft 1b on the rear end side is swingable up and down around the wheel drive shaft 1c on the front end side with respect to the pair of left and right support arms 2, 2. The diamond cutter 6 is cut into the pipe P to be cut as the rotating shaft 1b swings downward. Therefore, in order to set the cutting amount of the diamond cutter 6 according to the thickness of the pipe P to be cut, a screw is provided between the rear part of the pair of left and right support arms 2 and 2 and the rear part of the casing 1a of the cutting machine body 1. A fixed stop type cutting amount setting device 17 is provided.
[0020]
As shown in FIG. 3, a support shaft 3b is disposed in front of the cutting machine body 1 in the traveling direction (upper side in FIG. 3), and the same corresponding to the V pulleys 3a and 3a is provided at both ends of the support shaft 3b. A pair of left and right V pulleys 3c, 3c having a diameter are rotatably mounted. Between the V pulleys 3c and 3c and the V pulleys 3a and 3a, a pair of left and right V belts 3d and 3d whose lower surfaces are in frictional contact with the outer periphery of the pipe P to be cut are wound. A self-propelled device 3 is configured.
[0021]
The chain 4 with a roller has a predetermined length and a predetermined width wound around the outer periphery of the pipe P to be cut, and each connecting pin 4a extending in the width direction has an outer peripheral surface of the pipe P to be cut. A pair of left and right rollable rollers 4b and 4b are rotatably mounted, and a pair of left and right hook pieces 4c and 4c are fitted and mounted on the connecting pin 4a at one end. The chain with roller 4 has hook pieces 4c, 4c at one end engaged and connected to the connecting shaft 9b of the chain connecting bracket 9, wound around the outer peripheral surface of the pipe P to be cut, and the other end having a length. It is connected to the support shaft 3 b of the belt-type self-propelled device 3 through the adjustment fitting 10.
[0022]
The length adjusting bracket 10 has a connecting block 10b with a bolt insertion hole 10a fitted and attached to the connecting pin 4a at the other end of the roller-attached chain 4, and a screw 10c for fitting and attaching to the support shaft 3b. The connecting block 10d has a connecting bolt 10e that is inserted into the bolt insertion hole 10a and screwed into the female screw 10c. The other end of the chain 4 with a roller is adjusted by adjusting the screwing amount of the connecting bolt 10e. The length of the support shaft 3b is adjustable.
[0023]
Here, as shown in FIGS. 2 and 4, the cutting machine main body 1 includes a cover member 11 that covers the diamond cutter 6, and a cutting portion that is a cutting portion of the diamond cutter 6 (for convenience, denoted by P ′ in FIG. 5). And nozzles 12 and 12 ′ for supplying cooling water that is a cooling liquid toward the side surface of the diamond cutter 6. In FIG. 2, only one 12 of the nozzles is shown.
[0024]
The cover member 11 is integrally formed in the shape shown in FIG. 4 using flexible synthetic rubber or synthetic resin as a material, and has a hollow circular shape having a diameter and thickness that can cover the periphery of the diamond cutter 6 with a margin. A main body 11a, a peripheral edge portion 11b in which a part of the outer periphery of the main body 11a is cut out in a circular arc shape along the outer peripheral surface of the pipe P to be cut, and a boss portion 1d of the cutting machine main body 1 projecting from the center of one surface of the main body 11a A mounting cylinder portion 11c that can be fitted to the main body 11a. On one surface of the main body 11a, a separation portion 11d that reaches from the mounting cylinder portion 11c to the center of the peripheral edge portion 11b is formed. Insertion holes 11e and 11e 'are formed.
[0025]
And this cover member 11 inserts the diamond cutter 6 in the opening surrounded by the peripheral part 11b, opens the separating part 11d, and fits the mounting cylinder part 11c to the boss part 1d of the cutting machine body 1, The outer periphery is attached to the cutting machine main body 1 by tightening with an appropriate fastener such as a clip 13 (see FIG. 2).
[0026]
On the other hand, the nozzles 12 and 12 ′ are provided with an on-off valve mechanism and a tilting mechanism (not shown) so that the cooling water supply amount can be changed by the on-off valve mechanism and the injection direction can be changed by the tilting mechanism. If only the uniform cutting conditions are used, the supply amount and the supply position can be made constant.
As shown in FIG. 5, the nozzles 12 and 12 ′ are connected to a water injection device 20 installed in the vicinity of the pipe to be cut P via a hose 21, and the operation state is controlled by a control unit 22 described later. It is set up.
[0027]
As shown in FIG. 2, the nozzles 12 and 12 ′ are fixed to the outer periphery of the boss portion 1 d of the cutting machine body 1 via a universal stay 15, and the universal stay 15 includes three L-shaped brackets 15 a and 15 b. 15c are connected to each other by screws, and the distal end L-shaped bracket 15a can be three-dimensionally adjusted with respect to the proximal-end L-shaped bracket 15c by tightening the screws at any integrated movement position. It is like that.
[0028]
As shown in FIG. 4, the nozzle 12 ′ for injecting cooling water toward the side surface of the diamond cutter 6 corresponding to a portion other than the cut portion that is the cut portion of the diamond cutter 6 among the nozzles 12 and 12 ′, It is located at a position higher than the cut portion of the diamond cutter 6 and can be supplied with cooling water over almost the entire side surface of the diamond cutter 6. Is set to an amount that can be applied. That is, it is a supply amount necessary for suppressing the generation of frictional heat at the cutting point, and a supply amount that can be applied in a state where the entire side surface of the diamond cutter 6 is covered with cooling water except for the cutting point. It is considered that the relationship is larger than the supply amount at other locations. In addition, the cooling water supplied to the side surface of the diamond cutter 6 may be set to an amount that can be sprayed instead of being jetted when the diamond cutter 6 is intended to be cooled by using evaporation due to heat storage of the diamond cutter 6. Is possible. By setting this amount, the amount of cooling water that has not contributed to cooling travels along the side surface of the diamond cutter 6 and hangs down to the peripheral portion to prevent the softening of the soil around the laying position of the pipe P to be cut and the working environment by scattering. Prevention can be achieved. Further, regarding the change of the supply position, when it is relatively difficult to determine a high temperature position on the side surface of the diamond cutter 6 or in order to cause a rapid temperature drop, the nozzle 12 ′ is periodically swung, so-called It is also possible to perform a swing motion.
[0029]
Regarding the above-described cooling water supply position, (A) the cutting position of the diamond cutter 6 and the side surface of the upper portion of the cutting position corresponding to the other portion, both sides or one side of the diamond cutter 6, and (B) the cutting Any one of the positions that can be supplied from one place by combining the positions and the upper portions of the cut positions corresponding to other positions can be selected. The supply positions listed in (A) are the vertical positions on one side and the vertical positions on both sides of the diamond cutter 6, as shown in FIG. 4, and the supply positions listed in (B) are, for example, the neck of the nozzle It can be set by swinging or adopting a configuration in which a plurality of nozzles are provided at one place. In any case, the position can be selected based on the installation space and cost of the nozzle, and the position where the optimum cooling effect can be obtained can be set .
[0030]
The pipe cutting machine main body 1 according to the present embodiment is provided with a control system shown in FIG.
In FIG. 5, the control system includes a control unit 22, and the input of the control unit 22 has a leak that detects a leak of a fluid in the pipe to be cut, in this case, a gas in the vicinity of the cut portion of the pipe to be cut P. A detection sensor 23, a tachometer (not shown) of an electric or hydraulic motor, and a temperature sensor 24 such as an infrared sensor for detecting the surface temperature of the diamond cutter 6 are connected, and the water injection device 20 and the electric or hydraulic motor are connected to the output unit. The drive part of the drive source unit 25 is connected. In FIG. 5, reference numeral 26 indicates a sealing member such as a sealing bag disposed in the vicinity of the cutting point P ′ in the pipe P to be cut.
[0031]
In the control unit 22, the following control contents are executed in the operation control of the diamond cutter 6 and the water injection control of the water injection device 20.
(1) Supply amount of cooling water and supply positions of the nozzles 12 and 12 ′ according to the amount of frictional heat generated in the diamond cutter 6.
(2) The diamond cutter 6 is stopped when the cooling water supply is interrupted.
(3) The diamond cutter 6 is stopped when a leaked gas flowing in the vicinity of the cut portion, that is, a so-called crossover gas is detected. The detected concentration of the leaked gas in this case is set to a concentration that is lower than the lower explosion limit concentration of the natural gas for city gas and about ¼ of the lower explosion limit temperature, thereby increasing safety.
[0032]
Regarding the supply amount of the cooling water mentioned in (1), it takes into account that the temperature rise mode of the diamond cutter 6 is different between when the diamond cutter 6 starts cutting and when the cutting is continued, and is proportional to the amount of heat stored. The relationship is to increase supply. In other words, the temperature rise is most noticeable at the start of cutting. In this case, the amount of supply is increased, and when the cutting starts continuously, in other words, when the change in temperature gradient becomes small, When it is maintained at a temperature lower than the generation temperature, the supply amount is smaller than that at the start of cutting. Thereby, wasteful consumption of cooling water is suppressed.
Further, the supply position means that the nozzle direction is set so that the cooling water can be jetted to a position effective for lowering the temperature of the diamond cutter 6. Regarding these settings, information from the temperature sensor 24 for the diamond cutter 6 is used.
The supply amount and the supply position are both set to prevent the occurrence of sparks by enhancing the cooling effect of the diamond cutter 6 and the cut portion that have risen in temperature due to frictional heat.
[0033]
The contents listed in (2) are treatments in the case where the cooling water cannot be supplied due to an unforeseen situation, thereby preventing the occurrence of sparks due to abnormal temperature rise of the diamond cutter 6 in advance. it can. Regarding the setting in this case, although not shown, a water level sensor in the water injection device 20 and a pressure sensor for the nozzle are used.
[0034]
The contents listed in (3) are treatments for preventing the passing gas from being ignited by sparks, and at least the diamond cutter 6 can be stopped to suppress the occurrence of sparks. In this case, it is possible to continue supplying the cooling water until the diamond cutter 6 is stopped using the temperature sensor 23 of the diamond cutter 6.
[0035]
In the present embodiment, in the configuration as described above, when the cutting machine body 1 is mounted on the pipe P to be cut, the V belts 3d and 3d of the belt-type self-propelled device 3 are brought into frictional contact with the outer periphery of the pipe P to be cut. By rotating, it circulates along the outer periphery of the pipe P to be cut, and at the same time, the diamond cutter 6 is driven to rotate, and the pipe P to be cut can be sequentially cut.
[0036]
On the other hand, at the same time as the diamond cutter 6 is driven to rotate, the cooling water is supplied from the water injection device 20 toward the nozzles 12 and 12 ', the cooling water is injected from the nozzles 12 and 12' toward the cutting point, and Cooling water is applied to the side surface of the diamond cutter 6 other than the cut portion, and the entire side surface is covered with the cooling water. Thereby, the cutting part of the to-be-cut pipe P, the blade part of the diamond cutter 6 cut into this part, and the surface of the diamond cutter 6 other than this part are cooled.
At this time, the supply amount of the cooling water is set according to the temperature information from the temperature sensor 23, and since the temperature of the diamond cutter 6 is not so high at the beginning of the cutting, it is made slightly smaller than when it is continued. However, since it depends on the temperature of the diamond cutter 6 to the last, for example, in the case of continuous cutting work, the temperature of the diamond cutter 6 may be high even at the cutting start timing at different positions. Needless to say, the supply amount required for cooling is set.
[0037]
After the cutting is started, the conditions listed in the above (1) to (3) are monitored by the control unit 22, and the cooling water supply control from the nozzles 12 and 12 'and the drive control of the diamond cutter 6 are executed. The
[0038]
When this inventor compared with the case where a cooling water is not used regarding the temperature in the pipe cutting machine by this embodiment, the result shown in FIG. 6 was obtained.
FIG. 6 is a diagram showing a result of comparison between the case according to the present embodiment and the case where a new diamond cutter 6 is used in the configuration shown in Patent Document 3, and as is apparent from FIG. As a result of the embodiment, the temperature rise of the diamond cutter 6 can be suppressed as compared with the conventional configuration. In particular, when a new diamond cutter is used, although not shown in the figure, a cooling water supply temperature that is lower than the generation temperature of sparks can be obtained even without water, unlike the configuration of this embodiment. Otherwise, as shown in FIG. 6, a result of a rapid temperature increase was obtained.
[0039]
【The invention's effect】
According to the first aspect of the present invention, since the cooling liquid is supplied to the cut portion and other portions of the pipe, heat generation at the cutter and the cut portion is suppressed. As a result, even when the temperature rises due to heat generation, the difference from the spark generation temperature can be increased, so that ignition of the fluid in the pipe can be reliably prevented. In addition to the unexpected situation when the cooling liquid is used, the cutting operation can be automatically stopped when a leakage accident occurs in the pipe, so that the risk of ignition can be avoided.
[0040]
According to the second aspect of the present invention, the cooling liquid is supplied by the liquid supply means having the nozzle attached to the cover member provided so as to cover the cutter and the peripheral edge faces the outer peripheral surface of the pipe to be cut. Since the cooling liquid supplied to other than the part is applied to the side surface of the cutter, the cutter is not immersed in the cooling liquid. As a result, the movement resistance of the cutter is not increased, and heat generation can be suppressed while preventing a reduction in cutting efficiency.
[0041]
According to the third and fifth aspects of the present invention, since the cooling liquid supply amount is set according to the frictional heat amount of the cutter, it is possible to prevent the occurrence of sparks by optimizing the cooling efficiency and suppressing the temperature rise due to heat generation. Since the supply amount necessary for suppressing heat generation can be set, it is possible to prevent the generation of sparks while preventing the waste of the cooling liquid.
[0042]
According to the fourth aspect of the present invention, when the supply of the cooling liquid is interrupted, the cutter is stopped. Therefore, it is possible to prevent an abnormal temperature rise and reduce the risk of ignition.
[0043]
According to the sixth aspect of the present invention, the supply position of the cooling liquid can be selected, so that it is possible to reliably avoid the risk of ignition by sparks without adversely affecting the installation space and cost increase. It becomes possible.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an overall schematic structure of a pipe cutting machine according to an embodiment of the present invention.
FIG. 2 is an enlarged plan view of a cutting machine main body showing a mounting state of a cover member and a nozzle of the pipe cutting machine shown in FIG.
FIG. 3 is a plan view of the vicinity of the main body of the pipe cutting machine shown in FIG. 1;
4 is a cross-sectional view of a main part showing a configuration of a cover member used in the pipe cutting machine shown in FIG. 1;
FIG. 5 is a schematic diagram for explaining a system configuration used for the pipe cutting machine shown in FIG. 1;
6 is a diagram for explaining the result of comparing the operation of the system configuration shown in FIG. 5 with a conventional configuration. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cutting machine main body 1a Casing 1b Cutter rotation shaft 1c Wheel drive shaft 1d Boss part 2 Support arm 3 Belt-type self-propelled device 4 Chain 5 with a roller Power transmission tube 6 Diamond cutter 9 Chain coupling metal 11 Cover member 12, 12 'Nozzle 13 Clip 21, 21 ′ Hose 22 Control unit 23 Leak detection sensor 24 Temperature sensor 25 Drive source unit

Claims (6)

In a pipe cutting machine equipped with a cutting machine body that rotates around the circumference of the pipe to be cut while rotating the cutter and cutting the pipe to be cut sequentially over the entire circumference,
A configuration for supplying a cooling liquid to the cutting portion of the pipe to be cut and the blade portion of the cutter that cuts the portion and the cutter surface other than the portion ,
The pipe cutter according to claim 1, wherein the cutter is stopped when leakage of a fluid flowing in the pipe is detected at a cutting position of the pipe . The pipe cutter according to claim 1, wherein
The cooling liquid is supplied by liquid supply means having a nozzle attached to a cover member that covers the cutter and has a peripheral edge facing the outer peripheral surface of the pipe to be cut. The pipe cutting machine is characterized in that the cooling liquid supplied to is supplied in a state of being applied to the side surface of the cutter. In the pipe cutting machine according to claim 1 or 2,
A pipe cutting machine characterized in that at least a supply amount and a supply amount of the cooling liquid are changed in accordance with a frictional heat amount generated in the cutter. In the pipe cutting machine according to one of claims 1 to 3,
The pipe cutter has a configuration in which the cutter is stopped when the supply of the cooling liquid is stopped. In the pipe cutting machine according to claim 3,
A pipe cutting machine characterized in that the cooling liquid supply amount can be changed at the start of cutting by the cutter and at other times. In the pipe cutting machine according to any one of claims 1, 2, 3, and 5,
The supply position of the cooling liquid is either one of the blade part and the other side or one side of the other position across the cutter, the blade part of the cutter, and any position that can be supplied together. Pipe cutting machine characterized by being selectable.

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