JPH0288886A - Measuring device for quantity of soil removed of shield excavator - Google Patents

Abstract

PURPOSE:To simplify a measuring mechanism, and to reduce cost by installing a plurality of pressure sensors detecting soil-sand flow resistance pressure to a soil removing pipeline mounted in the soil removing path of a shield and fitting soil-removing quantity computing elements to the sensors. CONSTITUTION:A cutter head 11 is turned by a drive 12 disposed to the front of a shield body 10, and shield excavation is executed. Excavated soil and sand (a) are force-fed to a soil-removing pipeline 16 through a screw conveyor 13 driven by a driving motor 14. A plurality of pressure sensors 21 set up outside the pipeline 16 detect soil-sand flow resistance pressure in the pipeline 16, and outputs a signal 21a over a soil-removing quantity computing element 22. The computing element 22 arithmetically operates the quantity of soil removed on the basis of the detecting signal 21a. Excavated soil and sand (a) are carried and discharged onto a belt conveyor 17 from the pipeline 16, and housed in a truck 18 and carried to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an earth removal amount measuring device applied as ancillary equipment to an earth removal device of a shield excavator.

(Prior technology) Earth pressure system shield 9 of shield excavator (Tonosho type shield,
As shown in Fig. 8, the conventional earth removal measuring device and method for the earth pressure shield of a shield excavator is a belt conveyor (1
)K, a frame (2) is provided to support the excavated earth (a) that is continuously conveyed in the direction of the arrow, and the weight of earth and sand on the frame (2) is detected by a load meter (funnel 9 cells) (3), and the load is calculated. The discharge amount per hour is measured based on the weight detected by the meter (3), belt speed, etc. As shown in Fig. 9, an ultrasonic transmitter/receiver (4) etc. is arranged above the excavated earth (a) being conveyed in the direction of the arrow on the conveyor (1). 4), the cutting projected area of the excavated earth (al) directly below is detected, and the amount of earth removed per hour is measured by multiplying by the belt speed.As shown in Fig. 10, the primary earth removal system of the earth pressure system shield is The number of revolutions of the screw blades (6) is detected in the screw conveyor (5) which is set to
As shown in Figure 1, the excavated earth (a) pushed by the piston (8) of the pressure pump (7), which is the secondary earth evacuation system of the earth pressure shield, is advanced through the pipe, and at this time, There are various devices and methods, such as multiplying the number of cycles of the piston by the displacement volume generated by the reciprocating motion to find the theoretical amount of soil removed.

(Problem to be Solved by the Invention) The conventional soil removal amount measuring device reduces the voids when the soil is in a state where voids are likely to occur due to the influence of the properties of the excavated soil, the influence of the transportation mode, etc. This requires a mechanism and becomes a complicated device.

If the soil is conveyed in an open state using a belt conveyor or the like, the amount of soil to be discharged cannot be accurately determined due to the scattering of soil along the way, and a mechanism for preventing scattering is required.

Measurement detectors are expensive, and the equipment is complicated, resulting in high costs due to maintenance costs, etc. The method of correcting the theoretical value has problems with measurement accuracy, such as the need to change the correction coefficient depending on the operating condition.

The present invention was developed to address the above-mentioned problems, and its purpose is to simplify the measurement mechanism, reduce costs, and improve measurement performance and reliability of a shield tunneling machine. To provide a soil removal measuring device.

(Means for Solving the Problems) The present invention provides an earth removal pipe with a constant internal cross-sectional area for pumping excavated soil in the earth removal route of an earth pressure system shield in a shield excavator, and the earth and sand flow in the earth removal pipe. A plurality of pressure sensors that output resistance pressure detection signals are attached at intervals in the transportation direction, and an earth removal amount calculator is connected to each of the pressure sensors and calculates the amount of earth removed based on the pressure difference caused by the detection signals. By force-feeding the excavated soil through the earth removal pipe provided in the earth removal route, the excavated earth eliminates voids and prevents scattering, etc., and the earth removal pipe is spaced apart in the transport direction. By detecting the soil flow resistance pressure by the attached pressure sensor and calculating the amount of soil removed based on the detection by the soil removal amount calculator,
The measurement performance of the amount of soil removed has been improved and reliability has been achieved.

(Function) The excavated earth and sand are transported by the earth pressure system shield 1 in the shield excavator.
The earth is pumped through the earth removal pipe installed in the earth removal route, which reduces air gaps and prevents scattering, increasing detection accuracy. The earth flow resistance pressure of the excavated earth in the earthen pipe is properly detected, and the amount of earth to be removed is accurately calculated by the earth removal calculator based on the pressure difference resulting from each of the detections.

Detection and calculation of the amount of soil removed by the pressure sensor and the amount calculator are performed continuously by applying general theoretical formulas and in accordance with the soil properties of the excavated soil, etc., resulting in excellent accuracy. In addition, the seal excavator is operated properly and earth removal and shield excavation are carried out smoothly.

(Embodiment) A first embodiment of the present invention is shown in FIGS. 1 and 2. The cutter head (30) is a segment assembled and connected in a ring shape, which propels a plurality of propulsion jacks (therefore the shield body 0o) not shown, and
The cutter head (11) k rotates to carry out shield excavation, and the excavated soil (a) is transferred to a screw conveyor installed in the earth discharge path of the earth pressure system shield (±pressure type shield, mud type Geelby) and driven by the drive motor 04). 03), is connected to the rear gate 09 of the screw conveyor α■, and is conveyed to the belt conveyor αη via the discharge pipe Q6) with a constant internal cross-sectional area for pumping the excavated soil, and then discharged onto the underground track (19 It is a shield excavator that is housed in the upper cart Oa and carried outside.

Further, on the outside of the soil discharge pipe (16), there are a plurality of pressure sensors 121) 121 for detecting internal soil flow resistance pressure.
) are attached at an interval (1) in the transportation direction, and the pressure sensor I
21)? υ is connected with an earth removal amount calculator (23) that calculates the earth removal amount (Q) based on the pressure difference (Pl-P2) based on the detection signals (21a) (21a) Ic of the pressure sensor (213C) 1). ing.

The earth discharge pipe (16) is a screw conveyor α□□□
The trough is connected in series to the rear gate α9 of the trough and is formed into a cylindrical flow rate measuring trough with a constant internal cross-sectional area, through which the excavated earth (a) is pumped by the screw (13a) of the screw conveyor Q3).

The pressure sensors (21), (21) are connected to the earth discharge pipe 0.
The pressure gauge is attached to the outer wall surface of ω at a predetermined distance l in the transportation direction, and detects and outputs the flow resistance pressure of the excavated soil being pumped through the wall surface of the earth removal pipe 00.

The earth removal amount calculator is connected to the pressure sensor CυCυ, receives the detection signal (21a) (21a), and calculates the earth removal amount q based on the theory described later.

The theory of calculation of the amount of earth removed by the earth removal amount calculator (22) is explained in detail: (1) If the excavated earth and sand sent from the screw container αJ has a soil quality that contains a large amount of water, Bernoulli's formula is applied. .

That is, the sediment flow velocity in the earth discharge pipe 0e is V, and the gravitational acceleration is g.
, the inner diameter d of the earth removal pipe, the detection interval (interval in the transportation direction) of the pressure sensor (2I) eυ, and the excavated earth (a) in the earth removal pipe.
), the unit volume weight is γ, and the friction coefficient is λ1. If the pressure difference due to detection is pl-p2, then is a modification of Renoulli's equation and can be obtained by calculation, so from equation (2), the amount of soil discharged (
Flow rate) Q can be calculated by Q = A --- (3) A: Internal cross-sectional area of earth discharge pipe = upper πd2.

Further, equation (3) is expressed as follows and rearranged: Q == A1°3°r - (5) A1 is a constant determined geometrically.

The internal cross-sectional area of the earth removal pipe (le is constant), and K is an experimental coefficient determined by the soil properties and the condition of the earth removal pipe Oe.

Therefore, the amount of soil removed Q is calculated using Pl-P2 as the pressure sensor (2I).
Based on the detection by CD, it is calculated by an electrical arithmetic circuit according to equation (5).

(2) When the excavated earth and sand sent out from the screw conveyor 03 is considered to be a Bingham body of soil that can maintain a viscous fluid state, the average velocity in the pipe of the Bingham body [Va] is expressed by the following formula.

Further, by modifying equation (9), in order to obtain the amount of soil removed, μ = Plastic viscosity τ7 = Shear stress yield value γ A = Radius where the shear stress is equal to the yield value Also, the pressure difference, that is, the pressure loss p1-p2 is , is expressed by the following equation.

Here, γ = specific weight V, = average flow velocity α = (2 red 2) 11 constant number Simplifying this, Q = A ・ζ ・(Pt −P2) −−−−
(12rA2 is a constant determined by the shape, ζ is an experimental coefficient, and by setting each in advance, the amount of soil removed can be calculated immediately at P by detection, -P2,
Measurement becomes possible. When the flow becomes turbulent, the formula (
5) and each constant and coefficient in equation α2 can be changed to obtain the correct result.

(3) If the excavated soil sent out from the screw conveyor α moat is considered to be a solid with no fluidity, that is, if it is considered as the movement of a solid, F-foam, according to the equation of motion. ---(13) Here, F = Acting force W = Mold weight = Acceleration etc. According to the equation of acceleration motion, v2 = v2 + 2αL -+-04) Here
V - Final speed VQ = initial speed change speed movement distance Due to the frictional resistance in the earth removal pipe, the relationship between F and W is F = f1
-μ・W ---(15) Here, F =
The force that pushes the block of w'l is f1 - The force that pushes the screw controller (Y) on W = μ = the coefficient of friction between the earth and sand and the pipe wall of the earth removal pipe, and by transforming the formula θ■ and substituting it into the formula 04) To summarize, the amount of earth removed Q is expressed as: K = 2・Lg (constant) 1) - N = Vo (constant) P - screw pitch N = screw rotation number, and further, β = correlation coefficient p = Pipe pressure (detected value), formula 0e becomes as follows, and the amount of soil discharged is calculated.

In the present invention, an electric calculation circuit that can switch and calculate equations (5), α■, and (18) and set constants and coefficients of each equation as desired is equipped as an earth removal amount calculation unit (c), Even under any conditions, the amount of soil removed can be instantly and accurately calculated and measured and displayed based on the values detected by the pressure sensors (21) (21).

Figures 3 to 7: Show other examples of (pressure sensor (21) t21) arrangement, and as shown in Figure 3, the pressure sensor (2+a) (21a) A pressure sensor (2
1b) (21b) are installed on the left and right sides of the earth removal pipe 06), and pressure sensors (21c) (21) are installed as shown in FIG.
c) are installed on the upper and lower sides of the earth removal pipe 0e, and in order to further increase the detection sensitivity of the earth flow resistance pressure in the earth removal pipe 06), as shown in FIG. Earth removal pipe (
A recess is provided in 16) and a pressure sensor (21a) is attached thereto,
As shown in Figure 7, a pressure sensor (
21a) can also be provided.

(Effects of the Invention) The present invention has been purchased as described above, and excavated soil is pumped through the earth removal pipe provided in the soil removal route of the earth pressure system of the earth pressure system in the earth pressure system of the earth excavation machine. Detection signals of sediment flow resistance pressure are output at multiple locations in the soil removal pipe by multiple pressure sensors attached at intervals in the transportation direction, and the soil removal amount calculation unit calculates the amount of soil discharged based on the pressure difference between the detection signals. is calculated accurately, the influence of the properties of excavated soil, transportation mode, scattering, etc. is eliminated, and the detection accuracy and reliability are significantly improved. This is done based on the pressure difference from the detection signals of multiple pressure sensors, and by applying a general theoretical formula,
Continuous measurements are performed in response to the soil properties of the excavated soil, significantly improving the performance and reliability of measuring the amount of soil removed.

The mechanism has been significantly simplified and costs have been significantly reduced. Combined with improved emissions measurement performance, the shield excavator can be operated properly and earth removal and shield excavation can be carried out smoothly, greatly increasing work efficiency. be enhanced.

Although the present invention has been described above for implementation (flJ K), the present invention is of course not limited to such embodiments, and various design changes may be made without departing from the spirit of the present invention. It is scaly.

[Brief explanation of the drawing]

FIG. 1 is an overall longitudinal mechanical diagram showing the first embodiment of the present invention;
Figure 2 is an enlarged mechanical diagram of the earth removal piping part in Figure 1, and Figure 3 (
A+(B) and Fig. 4(A)(B) and Fig. 5(A)(
B) is l1l of FIG. 2 showing each embodiment of the pressure sensor arrangement.
sectional views of a-Illa and mb-mb corresponding parts,
Figures 6 and 7 are an enlarged side view and an enlarged vertical cross-sectional view of the earth discharge pipe showing other embodiments of pressure sensor arrangement, Figure 8 is a side view mechanical diagram of a conventional example, and Figure 9 is another example. 10 is a longitudinal sectional view showing another conventional example, and FIG. 11 is a longitudinal sectional view showing still another conventional example. 13--17: Earth removal route (screw conveyor, conveyor, etc.) 16: Earth removal pipe 21: Pressure sensor 22: Earth removal amount calculator Agent Patent attorney Shige Okamoto 2 outsiders Figure 3

Claims (1)

[Claims] An earth removal pipe with a constant internal cross-sectional area for pumping excavated soil is installed in the earth removal route of the earth pressure system shield in the shield excavator.
A plurality of pressure sensors that output detection signals of soil flow resistance pressure are attached to the earth discharge pipe at intervals in the transportation direction, and
An earth removal amount measuring device for a shield excavator, characterized in that an earth removal amount calculator is provided which is connected to each of the pressure sensors and calculates the earth removal amount based on the pressure difference based on the detection signal.