JP2004100417A - Hydraulic circuit for small-bore pipe burying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an allowance in space inside an underground pipe by reducing the number of hydraulic circuit hoses to a leading pipe when burying work is executed in a small-bore pipe propulsion method, to shorten a time for setting the underground pipe, and to reduce dangerous parts where leakage of oil or the like is expected to occurs. <P>SOLUTION: A hydraulic oil is supplied from an hydraulic unit installed outside a shaft using at least a hydraulic hose to a plurality of hydraulic devices mounted inside the leading pipe and driving non-concurrently by combining the necessary number of direction changeover valves and destination changeover valves, and to a plurality of hydraulic devices mounted inside the leading pipe and having different driving pressure by combining the necessary number of adaptation pressure reducing valves and the direction changeover valves. The hydraulic oil discharged from a plurality of hydraulic driving devices which are mounted inside the leading pipe is gathered at a discharging line side by using a check valve, and is collected from the leading pipe at the hydraulic unit installed outside the shaft using at least a hydraulic hose. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hydraulic circuit in a front pipe of a small diameter pipe propulsion method.
[0002]
[Prior art]
There is a method of burying relatively small diameter pipes such as water and sewage pipes and conduit pipes in the ground by excavating the ground at the burial point along the entire length of the pipeline. Violently and violently, adversely affecting the surrounding environment. In addition, when the burial position is deep, earth retaining is required at the time of excavation, extra work costs are required, and land subsidence is likely to occur at a nearby private house in a narrow work place.
[0003]
On the other hand, the ground was excavated in the horizontal direction from the inside of the pit excavated from the ground surface by a cutter head provided at the tip of the front pipe, and the excavated earth and sand was laid in the front pipe and the buried pipe where the excavated soil was directly passed through a screw conveyor or the like. Connect the buried pipe to the leading pipe and push it from the rear through the discharge pipe or muddy excavated earth and sand from the pit through the sending and discharging mud pipe, and push the buried pipe sequentially from underground to go underground. There is a buried propulsion method.
[0004]
According to this method, a mud pipe for excavated earth and sand, an air line for operation such as a pinch valve, a transportation line for excavation aid such as a lubricant, a hydraulic hose, two signal cables of a drive system and a detection system, a propulsion direction are provided in a buried pipe. A confirmation target path must be provided.
[0005]
[Problems to be solved by the invention]
However, with the above-mentioned propulsion method, the problem caused by the above-mentioned excavation can be solved.However, when trying to bury a small-diameter pipe having a diameter of 300 mm or less, the pipe diameter is small, and the above-described excavation / discharge There is also a need to secure space for pipes, hoses, signal cables, etc., and a target for confirming the digging course, and the size of the hydraulic hose and coupler is limited.
[0006]
When the diameter of the hydraulic hose is limited, for example, when the inner diameter becomes 15 mm or less, the pipe resistance per unit distance increases depending on the hydraulic oil flow rate, and a considerable pressure drop occurs when the pressure loss of the coupler or the like is added. Therefore, there is a problem that the excavating ability rapidly decreases as the excavation progresses. Further, since the number of connecting points increases in proportion to the number of hydraulic hoses, there is also a problem that there is a danger that oil leaks from the connecting portions of the hydraulic hoses and the couplers come off. On the other hand, the nervousness of the builder has been heavily used for dealing with the pressure loss of the hydraulic line and for oil leakage.
[0007]
Furthermore, in the small-diameter pipe propulsion method, the procedure of once disconnecting the hydraulic hose in the process of extending the buried pipe and repeating the procedure for setting it through the extended buried pipe is repeated. The time required increases, and the net result is an increase in the time required for construction.
[0008]
Here, the number of hydraulic hoses to be laid in the buried pipe in the conventional method is six, for example, when there are three hydraulic drive components in the leading conduit and when designed with a normal hydraulic circuit configuration. . In the case of a primitive piping configuration, the number of hydraulic hoses is twice the number of hydraulic drive actuators.
[0009]
In order to reduce the number of hydraulic hoses, for example, in Japanese Patent No. 3219740, a hydraulic unit for driving a direction correcting jack and a water shutoff bypass valve for a feed / drainage pipe is temporarily laid in a buried pipe by mounting a hydraulic unit in a front pipe. Hydraulic hose is eliminated. However, Japanese Patent Application Laid-Open No. 2000-328876 states that if the buried pipe diameter is 300 mm or less, it is considered that mounting the hydraulic unit in the front pipe becomes difficult spatially, and therefore it is preferable to install the hydraulic unit on the ground.
[0010]
Further, in these patent examples, a method is employed in which the rotational driving force of the cutter head is obtained from an electric motor mounted in the front conduit. This is because the electric wiring is smaller in diameter than hydraulic piping or the like, has a large space for use, and has an advantage of being easy to handle. However, the construction site is in a muddy mud environment, and using large power at the tip of the underground excavation is not preferable because there is a danger of electric leakage due to cable damage, cutting accident, insulation failure and the like.
[0011]
The present invention has been made to solve the problems of the above-described conventional technology, and has been made to reduce the number of hoses of hydraulic oil supplied to the leading conduit of the small-diameter pipe propulsion method, and to reduce the number of hoses in the buried pipe at the time of burying work. An object of the present invention is to provide a sufficient space to reduce the time required for setting a buried pipe and to reduce a danger point such as an oil leak to half or less.
[0012]
Another object of the present invention is to make it possible to increase the size of hydraulic hoses / couplers and the like, thereby minimizing an increase in pressure loss caused by pipe resistance due to the extension of buried pipes, and facilitating operation management.
[0013]
[Means to solve the problem]
As a means for solving the above-mentioned problems, the present invention combines a required number of directional switching valves and a destination switching valve into a plurality of non-simultaneously driven hydraulic devices mounted in a front conduit, and also mounted in the front conduit. For a plurality of hydraulic devices with different driving pressures, the required number of compatible pressure reducing valves and direction switching valves are combined to supply hydraulic oil from a hydraulic unit installed outside the shaft with at least one hydraulic hose. Hydraulic oil discharged from a plurality of hydraulic drive units mounted in the front conduit was collected on the discharge line side using a check valve, and was installed outside the shaft with at least one hydraulic hose from the front conduit. It is to collect it in the hydraulic unit.
[0014]
By doing so, the number of hydraulic hoses temporarily laid in the buried pipe can be reduced to at least half or less, and the above-mentioned problem can be solved, so that the work efficiency can be significantly improved.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an outline of a propulsion device will be described first with reference to a conceptual drawing showing small diameter pipe burying, and then a hydraulic circuit of a conventional device will be described first with reference to the drawings for comparison with the present invention.
[0016]
FIG. 3 is a conceptual view showing an entire propulsion device with a small-diameter pipe buried as an example. A hydraulic motor 3 connected to a cutter head 2 is mounted in a front pipe 1. Here, the case of the conventional method will be described. The hydraulic motor 3 and the hydraulic unit 5 are connected by two hydraulic hoses, and 7c is a piping on the discharge side of a hydraulic pump 6 provided in the hydraulic unit 5. Reference numeral 7d denotes a pipe in which hydraulic oil returns from the hydraulic motor 3 to the hydraulic unit 5.
[0017]
Four cylinders for correcting the excavation direction are attached to the cutter head 2 at the top, bottom, left, and right. Two hydraulic hoses (7a, 7b) for discharge and return are piped from the hydraulic unit 5 for this drive.
[0018]
Further, it is necessary to temporarily stop the sending and discharging of excavated mud when the buried pipe is added, and two hydraulic hoses (7e, 7f) for supplying and discharging from the hydraulic unit 5 are used to operate the bypass valve of the sending and discharging mud pipe. A total of six hydraulic hoses are laid in the buried pipe.
[0019]
The cross section of the front pipe taken from the direction of arrow A is shown in the figure. As is clear from the figure, in addition to the above-mentioned six hydraulic hoses 7, the pipe 20 for sending and discharging the excavated earth and sand is provided in the pipe. 21 Drilling aid (lubricant etc.) supply pipe 23, detection signal cable 25, drive signal cable 26 and other space for target 27 for excavation course correction are required, and it is difficult to take play space. Therefore, it is common that the outer diameter of the hydraulic hose 7 is also significantly restricted.
[0020]
FIG. 2 shows, as an example, a configuration diagram of the conventional hydraulic circuit shown in FIG. 3, in which three hydraulic drive components (the hydraulic motor 3, the direction correcting jack 4, and the mud pipe bypass valve 10) are provided. Each is composed of an independent hydraulic system.
[0021]
First, in the auger section, hydraulic oil is sent from the hydraulic pump 6b to the hydraulic motor 3 via the direction switching valve 9b, and a rotary excavating force is applied to the cutter head 2. Reverse rotation can be achieved by switching the direction switching valve 9b between the discharge side and the return side.
[0022]
Next, as a correcting unit, the hydraulic oil from the hydraulic pump 6a is sent to the designated direction correcting jack 4 through the direction switching valve 9a and the opening / closing instruction valve 8, and the direction correcting jacks 4a, 4b, 4c, and 4d. In the desired direction. At this time, the four direction correcting jacks 4a, 4b, 4c, and 4d attached to the four directions of the open / close instruction valves 8a, 8b, 8c, and 8d are adjacent to the predetermined upper, lower, left, and right directions. Two open indications are made through the signal cable and actuated thereby. After the correction is completed, the direction switching valve 9a on the hydraulic pump 6a side is reversed to return the hydraulic jack 4 to the original state, and the construction is continued.
[0023]
The third hydraulically driven component, the excavated sediment sending / discharging pipe bypass valve 10, sets off the mud staying in the sending / discharging pipes 20 and 21 at the bottom of the pipe at the time of stopping the feeding / discharging when the buried pipe 19 is added. In order to cause clogging of the line, it is necessary to replace the inside of the sending / discharging pipe with water or a solid-filtration / recovery liquid before stopping the sending / discharging. Therefore, before the feeding and discharging mud is stopped, the hydraulic oil is sent from the hydraulic pump 6c to the feeding and discharging mud pipe bypass valve 10 via the directional switching valve 9c to put the feeding and discharging mud line into a bypass state to remove the sediment in the pipe. Is When the refilling of the buried pipe 19 is completed and the excavation is started, the direction switching valve 9c is switched between the discharge side and the return side to return to the original line.
[0024]
Although the construction method is the same as the conventional method, an example of the embodiment with the hydraulic circuit configuration of the present invention will be described based on FIG. One hydraulic pump 6A is installed in the hydraulic unit 5 outside the starting shaft, and a relief valve 11 for adjusting pressure on a discharge side and a return side of hydraulic oil and an unload valve for preventing heat accumulation of hydraulic oil during unloading. 16 and two paths. The two hydraulic hoses (outlet 7A and return 7B) from the hydraulic unit 5 are connected to the hydraulic hose 7 temporarily laid in the buried pipe by the coupler 12, and further connected by the coupler 12 to the hydraulic oil in the destination pipe 1. It is configured to guide. Then, the discharge side is divided into two parts in the leading conduit, one of which is received via the direction switching valve 9A to the direction correcting jack 4 and the other via the pressure reducing valve 15 via the rear direction switching valve 9B. The piping is arranged so that hydraulic oil is sent to the hydraulic motor 3 or the bypass valve 10 for the sending and discharging mud pipe by the destination switching valve 14A.
[0025]
Here, the flow and function of the hydraulic oil will be described. The discharge from the hydraulic pump 6A is returned to the hydraulic oil return tank 17 by an amount equal to or higher than the set pressure by the relief valve 11, and the hydraulic oil at the set pressure is connected by the coupler 12. After passing through one supply line 7A in the buried pipe, it reaches the inlets of four direction correcting jacks 4 mounted on the upper, lower, left and right sides via a directional switching valve 9A mounted in the front pipe 1. Here, when it is necessary to correct the direction, the opening / closing instruction valve is opened through a driving signal cable so as to drive the two adjacent 4A-4B, 4A-4C, 4B-4D or 4C-4D described above. A signal is sent, hydraulic pressure is applied to the direction correcting jack 4 (any one of 4A-4B, 4A-4C, 4B-4D, and 4C-4D), and the cutter head 2 moves in the required direction. At this time, the hydraulic oil discharged from the opposite side of the jack 4 (any one of 4A-4B, 4A-4C, 4B-4D, and 4C-4D) passes through the discharge side of the direction switching valve 9A to the check valve 13. It is sent and joins the discharge line of the hydraulic motor 3 at that time by the action of the check valve 13. Then, when the direction correction is completed, the discharge and discharge of the direction switching valve 9A are reversed to apply a reverse pressure to the two driven direction correction jacks 4 to return to the original position. At this time, the hydraulic oil discharged from the positive side of the direction correcting jack 4 (any one of 4A-4B, 4A-4C, 4B-4D, and 4C-4D) is discharged from the direction switching valve 9A in the direction. It is sent to the check valve 13 via the same line as that at the time of correction, and joins the discharge line of the hydraulic motor 3 at that time.
[0026]
Next, similarly to the above, the hydraulic motor 3 discharges oil from the hydraulic pump 6A through the hydraulic oil supply hose 7A in the buried pipe 19 connected by the coupler 12, passes through the hydraulic jack 3 for direction correction in the front pipe 1. Through the pressure reducing valve 15 (dropped to the set pressure of the hydraulic motor) attached to the part branched from the line, through the direction switching valve 9B, and further through the receiving destination switching valve 14A between the hydraulic motor 3 and the bypass valve. It is supplied to the hydraulic motor 3. When the direction of the direction switching valve 9B is switched, the reverse rotation of the hydraulic motor can be performed.
[0027]
The hydraulic oil discharged from the hydraulic motor 3 returns from the destination switching valve 14B to the hydraulic unit 5 via the direction switching valve 9B, the hydraulic oil discharge hose 7B laid in the buried pipe. Further, the drain discharged from the hydraulic motor 3 is distributed to the hydraulic oil discharge side of the hydraulic motor 3 by the check valve 13, so that the drain merges with the discharged oil and returns to the hydraulic unit 5.
[0028]
Then, when the buried pipe is added, the hydraulic motor 3 stops by switching the hydraulic oil supply to the sending / draining pipe bypass valve 10 by the destination switching valve 14A, and the bypass valve 10 is opened to open the sending / draining pipe. 21 and 22 are connected at that portion, and the earth and sand in the line are removed and replaced. At this time, the hydraulic oil discharged from the hydraulic operating portion of the bypass valve 10 returns to the hydraulic unit 5 from the destination switching valve 14B via the direction switching valve 9B, the hydraulic oil discharge hose 7B laid in the buried pipe.
[0029]
When the extension is completed, and before the excavation is resumed, the bypass valve 10 is returned to the original state by switching the direction switching valve 9B so that the supply side and the discharge side are reversed and the hydraulic oil flows through the destination switching valve 14B. The hydraulic oil discharged at this time returns to the hydraulic unit 5 through the hydraulic oil discharge hose 7B laid in the buried pipe via the destination switching valve 14A and the direction switching valve 9B.
[0030]
Thereafter, the destination switching valves 14A and 14B are switched to the hydraulic motor 3 side, and the supply side and the discharge side of the direction switching valve 9B are reversed and returned to the original state, and the excavation and burial is promoted.
[0031]
By constructing such a hydraulic circuit, in this example, the hydraulic hose 7 temporarily laid in the buried pipe 19 is reduced to one-third and the coupler 12 is also reduced to one-third accordingly. , Set and offset times are reduced, and danger points such as oil leaks and coupler 12 detachment can be reduced to one third. Also, one hydraulic pump 6 is sufficient.
[0032]
Furthermore, for example, in the case of burying a φ200 mm pipe, the number of hydraulic hoses can be reduced from six to two, and the hydraulic hose of 20.4 mm in outer diameter × 12.7 mm in inner diameter conventionally used for burying pipes of this diameter is used. Even if you use two hydraulic hoses with an outer diameter of 28.7 mm and an inner diameter of 19 mm, which are two steps larger than the six pipes, the occupied area of the space inside the buried pipe can be reduced and the coupler size can be one step higher, so the inner diameter of the hose The pressure loss per 100 m together with the expansion could be reduced from about 4 MPa reciprocation to about 1.5 MPa at a hydraulic oil flow rate of 22.5 L / min.
[0033]
If the pressure loss is about 1.5 MPa for reciprocation, there is no need to worry about the allowable pressure of the hydraulic motor. It is not necessary to pay attention to the loss of excavation ability due to loss.
[0034]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
{Circle around (1)} The number of hydraulic hoses is reduced, and the time for setting and offsetting the buried pipes can be reduced.
{Circle around (2)} The decrease in the number of set hoses can be used for increasing the diameter of the hose (including the increase in the size of the coupler), so that the pressure loss in the path accompanying the longer distance can be reduced.
{Circle around (3)} By reducing the number of hose connection locations, danger locations such as oil leakage and coupler disconnection are reduced by half.
{Circle around (4)} By subtracting the total sectional area of the hydraulic hose according to the method of the present invention from the total sectional area of the hydraulic hose according to the conventional method, it becomes positive, and the use space can be expanded.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a hydraulic circuit according to the present invention.
FIG. 2 is a configuration diagram of a conventional hydraulic circuit.
FIG. 3 is a conceptual diagram showing the entire propulsion device for burying a small-diameter pipe.
(The uppercase alphabetic letters attached to the symbols of valves, jacks, pumps, etc. refer to the present invention, and the lowercase letters refer to conventional methods.)
DESCRIPTION OF SYMBOLS 1 Lead pipe 2 Cutter head 3 Hydraulic motor 4 Direction correction jack 5 Hydraulic unit 6 Hydraulic pump 7 Hydraulic hose 8 Opening / closing instruction valve 9 Direction switching valve 10 By-pass valve for sending and discharging mud pipe 11 Relief valve 12 Coupler 13 Check valve 14 Destination switching Valve 15 Pressure reducing valve 16 Unloading valve 17 Hydraulic oil return tank 18 Propulsion device 19 Buried pipe 20 Mud feed pipe 21 Drain pipe 27 Target 30 Starting shaft

Claims (1)

In a pipe burial device that pushes and buries a small-diameter pipe into the ground, a required number of directional switching valves and destination switching valves are combined with a plurality of non-simultaneously driven hydraulic devices mounted in the front pipe, and For a plurality of hydraulic devices with different driving pressures mounted on the shaft, the required number of compatible pressure reducing valves and directional control valves are combined, and the hydraulic unit installed outside the shaft is hydraulically operated with at least one hydraulic hose. Hydraulic oil that supplies oil and is discharged from a plurality of hydraulic drive units placed in the front pipe is collected on the discharge line side using a check valve, and the shaft is connected with a minimum of one hydraulic hose from the front pipe. A small-diameter pipe burying device, which is collected in a hydraulic unit installed outside.

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