JPH023878B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a monitoring and control device for a shield tunneling machine. Excavation using a shield excavator includes not only the original excavation but also extra excavation to change direction.
A display device and a viewing window are provided in the cab of the shield tunneling machine to detect the current digging position and direction. Examples of detection using conventional viewing windows and display devices will be described below, focusing on the case of over-excavation. When excavating in a straight line with a shield excavator,
It is sufficient to excavate a cross-sectional area of the same diameter as the outer diameter of the shield excavator while rotating the cutter head in the forward or reverse direction. We have to dig deeper and be able to change direction. For this reason, in a shield excavator, an overcutter is installed near the outer periphery of the cutter head, which expands and contracts as needed, so that the rotational force of the cutter head can be used to overcut the outer periphery of the shield excavator. It is configured. The means for expanding and contracting the overcut can be roughly divided into two types: using a hydraulic jack and using a screw jack. In either case, since the over cutter is built into the rotating cutter head, its movement cannot be directly observed from the operator's cab, which is installed in the non-rotating position of the shield body. Due to this, extra digging work was being carried out. FIG. 1 shows a conventional shield excavator configured so that the amount of expansion and contraction of the overcutter and its rotational position can be confirmed. In FIG. 1, an overhead 1 is installed at the front of a shield body 2, and is rotatably supported by the shield body 2 via a turning wheel 3. As shown in FIG. 4 is an over cutter installed in the rotating cutter head 1,
This over cutter 4 is configured to be extended and contracted by a hydraulic jack 5. Although not shown, the hydraulic jack 5 connects to the shield body 2 via a rotary joint 6.
It is connected to an internal hydraulic power source. Reference numeral 7 denotes an expansion/contraction detection device which is connected to the hydraulic jack 5 to detect the amount of expansion/contraction of the over cutter 4, and is installed on the cutter head 1 side. Further, a viewing window 8a is provided in the partition wall 8 of the shield body 2, and the amount of expansion and contraction of the expansion/contraction amount detection device 7 can be visually observed through the viewing window 8a. The cutter head 1 has a drive device 9 installed on the shield body 2 side and a reduction gear 10 installed on the cutter head 1 side.
As a result, the shield body 2 is rotated relative to the shield body 2.
Along with this, the over cutters 4 are rotated as one. In order to detect the rotational position of the over cutter 4, a rotational position detector 11 is mounted on the reduction gear 10. By visually observing the pointer of this rotational position detector 11, the rotational position of the over cutter 4 can be determined. Next, the extra digging work using the apparatus shown in FIG. 1 will be explained. First, the shield excavator is stopped, and the cutter head 1 is rotated to a position where the expansion/contraction amount detection device 7 can be visually observed through the viewing window 8a, and then stopped at that position. Next, when the hydraulic jack 5 is extended, the expansion/contraction amount detection device 7 extends at the same time as the overcutter 4, so while checking the amount of extension, the overcutter 4 is extended by the necessary over-digging depth, and the over-digging amount is set. do. Next, the cutter head 1 is rotated forward and backward while observing the pointer of the rotational position detector 11 that detects the rotational position of the overcutter 4 to advance into the excavated hole. When the over-digging work is carried out in this manner, the shape of the over-digging is shown in FIG. 2. S indicates the amount of excess excavation, and D indicates the outer diameter of the shield excavator. As described above, this conventional shield excavator performs over-digging work while checking the amount of expansion and contraction of the overcut and its rotational position, resulting in poor work efficiency and requiring skill to operate. In order to improve the problems of this conventional example, the applicant has
Both filed an application for a shield excavator equipped with a display section that could display the progress of excavation (patent application filed in 1982).
103619.Shield excavator). The features of this shield tunneling machine are as follows. In a shield excavator that excavates a face by rotating a cutter head that is rotatably installed in the front part of the shield body, an over cutter that expands and contracts with a hydraulic jack is installed in the cutter head, and the over cutter is extended and contracted by a hydraulic jack. The shield body includes a display meter that continuously displays the amount, and an over-digging mode setting device that can freely set the over-digging mode determined by the over-digging depth based on the amount of expansion and contraction of the overcut cutter and the over-digging range based on the amount of rotation. The cutter head is installed in the operator's cab, and is characterized in that excavation control in the set over-digging mode can be performed by an electric control circuit regardless of the direction of rotation of the cutter head. The details will be explained below. First, a display meter that continuously displays the amount of expansion and contraction of the overcut will be explained. FIG. 4 shows the hydraulic control circuit for the hydraulic jack 5 that extends and retracts the over cutter 4. On the downstream side of the hydraulic pump 13 driven by the electric motor 12, there is a relief valve 14 that sets the circuit pressure, and a hydraulic jack. An electromagnetic valve 15 as a directional switching valve for switching between expansion/contraction and stop of 5 is provided. Drive lines 16 and 17 are provided downstream of the solenoid valve 15. The pipe line 16 side is connected to the head chamber of the hydraulic jack 5 via the rotary joint 6, and the pipe line 17 side is connected to the rod chamber of the hydraulic jack 5 via the simulating hydraulic jack 18 and the rotary joint 6. The hydraulic jack 18 has the same specifications as the hydraulic jack 5, and its head chamber is connected to the pipe line 17.
The rod chamber is connected to the rod chamber of the hydraulic jack 5 via a rotary joint 6. Thus, the hydraulic jack 18 simultaneously contracts by the same amount when the hydraulic jack 5 extends, and simultaneously extends by the same amount when it contracts. The conduits 16 and 17 are provided with flow rate adjustment valves 20 and 20 that can minutely adjust the expansion and contraction speeds of the hydraulic jack 5. A return line 21 from the solenoid valve 15 is connected to an oil tank 22.
Also, the piston rod 18a of the hydraulic jack 18
is connected via a potentiometer 23 to an expansion/contraction amount indicator 24 installed in the driver's cab. Therefore, the solenoid part SOL1 of the solenoid valve 15
When energized, the solenoid valve 15 is switched to position a, so that the oil discharged from the hydraulic pump 13 is transferred to the drive line 1.
6 to the head chamber of the hydraulic jack 5, the over cutter 4 is extended, and the amount of extension is continuously displayed on the display meter 24. Similarly, when the solenoid part SOL2 of the solenoid valve 15 is energized, the solenoid valve 15 is switched to position b, so that the oil discharged from the hydraulic pump 13 is supplied to the rod chamber of the hydraulic jack 5 through the drive line 17. As the overcut 4 is reduced, the amount of reduction is continuously displayed on the display 24. Therefore,
By switching the solenoid valve 15 while looking at the pointer of the expansion/contraction amount indicator 24 installed in the operator's cab, the amount of expansion/contraction of the over cutter 4 can be freely set. Next, a description will be given of an over-digging mode setting device that can freely set an over-digging mode determined by the over-digging depth based on the amount of expansion and contraction of the overcut cutter and the over-digging range based on the amount of rotation. As shown in FIG. 5, a rotational position detector 11 is installed on the reduction gear 10 on the cutter head 1 side, and its output shaft is configured to rotate at the same time as the cutter head 1. A synchro oscillator 25 is connected to the output shaft of the rotational position detector 11. The synchro receiver side is connected to a rotation pointer installed in the driver's cab that continuously displays the rotational position of the overcut. FIG. 6 shows the over-digging configuration setting device 26 installed in the driver's cab. 24 is the expansion/contraction amount detector of the over cutter 4 mentioned above, and 27 is an angle scale divided equally on the circumference (180° to the right, 180° to the left).
A scale plate 28 is engraved with . The rotational position of this pointer 28 is over cutter 4.
The rotation position is displayed. Movable contacts L1 to L8 are installed on the outer periphery of the scale plate 27, and these movable contacts L1 to L8 are set on the outer periphery of the scale plate 27 by adjusting setting knobs S1 to S8 installed at the lower part of the scale plate 27. It is designed to be able to slide. Movable contact L1~ set in this way
It is sufficient to configure an operation control circuit that controls the amount of expansion and contraction of the over cutter 4 when the rotation pointer 28 overlaps L8. Now, the case where this shield excavator is used to perform excavation in the ideal over-excavation shape shown in FIG. 3 will be described. First, the setting knobs S1 to S8 are adjusted to set the setting angles of the movable contacts L1 to L8 to the positions shown in FIG. Next, when the rotation pointer 28 overlaps each set movable contact, the over cutter 4
Set the expansion/contraction control for .

【table】

[Table] The operation of Table 1 will be explained below in an easy-to-understand manner. Table 1 separately shows the case where the pointer 28 in FIG. 6 rotates to the right and the case where the pointer 28 rotates to the left. In either case, the overcutter 4 is controlled to extend or contract depending on the rotational position of the pointer 28. In clockwise rotation, the pointer 28 moves from L1→
The position moves as L2→...→L8→L1→...→L8→.... When turning left, the pointer 28 moves from L8→L7→...
→L1→L8→…L1→…The position moves as follows.
Since the operation content is essentially the same for both clockwise and counterclockwise rotations, the relationship between the pointer 28 and the control of the overcut cutter 4 will be explained using an example of clockwise rotation. In clockwise rotation, the over cutter 4 extends when the pointer 28 overlaps the position L1. The over cutter 4 moves from L1 to L2 and when the pointer 28 overlaps the L2 position, the over cutter 4 that has been extended until now stops extending. While remaining in this extended state, the pointer 28 moves from L2 to L3. The over cutter 4 contracts when it reaches L3. As it moves further, the reduction stops at the L4 position, and the over cutter 4 starts extending again at the L5 position. L6
At the position, it stops in its extended state, and
This state is maintained between L6 and L7. Start reducing at the L7 position, and over cutter 4 at the L8 position.
The reduction of will be stopped. Below, L1 → L2 →...L8
→ The over cutter is automatically operated according to the rotational position, and overcutting as shown by the dotted line in FIG. 7 is achieved. The position confirmation of each position L1 to L8 and intermediate positions thereof by the pointer 28 and the accompanying control of extension, contraction, etc. of the overcut are performed by an electric circuit. Similarly, for counterclockwise rotation, the over cutter 4 is rotated according to each position of the pointer 28.
The expansion, reduction, etc. of the image are controlled. According to this shield excavator, operation is much easier, and additional excavation work can be carried out more accurately and quickly. However, there are problems as follows. The amount of expansion and contraction of the overcut cutter and the rotational position of the rotary cutter were displayed on separate displays.
Therefore, it has been difficult to intuitively judge what shape the excess excavation amount actually takes. Moreover, the extension/retraction control of the overcut can only be carried out if there are mechanical restrictions on the setting range of the rotation angle of the extension/retraction position. Therefore, not all practical overcut shapes are possible. For example, as shown in Figure 12, the extended and retracted positions of the overcut are separated into left and right areas from the center, or as shown in Figure 13, the extended and retracted positions are 1/4 of the total. In the case of shapes that are concentrated within a region, it is mechanically difficult to implement. The purpose of the present invention is to
In other words, the present invention provides a monitoring and control device for a shield excavator that allows the over-excavation shape to be viewed directly and improves the efficiency of over-excavation work. The gist of the present invention is to acquire the overcutter position from an overcutter position detector and the overcutter stroke length from a stroke detector that detects the stroke of the overcutter, and display a two-dimensional overcutter tip trajectory. The point is that we made them do it. Further, in the present invention, the extension and contraction of the overcut can be controlled from the outside by setting the rotation angle position and stroke amount. The present invention will be explained in detail below. FIG. 8 shows an embodiment of the present invention. The constituent elements will be explained in order below. Overcutter position detector 101...Detects the rotational position of the overcutter, and is, for example, a synchro transmitter. Stroke detector 102...Detects the stroke of the overcut, and is, for example, a potentiometer, a synchro transmitter, an encoder, or the like. Digital angle calculator 103: receives the output of the detector 101 and converts the rotation angle into a digital signal. Forward/reverse setting device 104: Indicates the rotation direction of the over cutter to the comparator 105. Comparison calculator 105: outputs an expansion or contraction signal at a set angle position. Memory erasure circuit 107: An output signal generation circuit for erasing the tip trajectory of the overcut cutter on the display 108 at a fixed position (for example, 0°) every rotation. Overcutter display 108: Displays the trajectory of the tip of the overcutter, including its rotational position and stroke. Use a memory scope, etc. that has an afterimage phenomenon to display the trajectory. Digital angle setting device 109: Sets the “extension” or “retraction” position of the overcut. Arithmetic units 110, 111... "Extension" or "Shrinkage"
The signal and stroke upper and lower limit signals are used as control signals for the overcut. Stroke calculator 112: A device that receives the signal from the detector 102 and converts the stroke amount into an analog signal. Stroke upper limit setter 113: something that determines the upper limit of the stroke amount. Stroke lower limit setter 114: determines the lower limit of the stroke amount. Analog angle calculator 117: receives the signal from the detector 101 and converts the rotation angle into an analog signal. Display calculation unit 115: A unit that simultaneously receives the rotation angle signal and the stroke signal and calculates the position of the tip of the overcut. Mode setting device 116: A mode setting device that selects and sets whether the overcutter "extends" once or twice in one rotation of the overcutter. There are two types of settings: "Mode 1" and "Mode 2". With the above configuration, the over cutter position detector 10
1 corresponds to a synchro oscillator that performs the detector function in FIG. The stroke detector 102 corresponds to the expansion/contraction detection device 7 in FIG. 1 or the potentiometer 23 in FIG. 4. First, a method of displaying the over-excavation shape will be explained with reference to FIG. 8. Over cutter position detector 10
1 (for example, a synchro oscillator, encoder, potentiometer) is converted into an analog signal corresponding to a rotation angle by an analog angle calculator 117. On the other hand, the output of a stroke detector 102 (for example, a potentiometer, an encoder, a synchro transmitter) that measures the expansion and contraction stroke of the overcut is converted by a stroke calculator 112 into an analog signal corresponding to the stroke amount. By simultaneously obtaining these two signals (angle and stroke amount), the position of the tip of the overcut can be determined two-dimensionally (on a plane). This calculation is performed by the display calculator 115, and the tip position is processed to have two analog values, a value in the X direction and a value in the Y direction. The contents of the calculation by the display calculation unit 115 are as follows. By tracking the analog signal corresponding to the rotation angle, the rotation locus of the overcutter 4 can be obtained. On the other hand, the analog signal corresponding to the stroke amount is the amount of expansion and contraction of the overcut on each rotation locus.
The display calculator 115 takes in an analog signal corresponding to the rotation angle and an analog signal corresponding to the stroke.
Calculates values in the X and Y directions for display. This calculation involves calculating the tip position of the overcut cutter 4 from an analog signal corresponding to the stroke amount, and further,
This calculation result and an analog signal corresponding to the rotation angle are combined to obtain X and Y coordinate values for two-dimensional display. The first calculation is to calculate the tip position of the overcut cutter 4 corresponding to the stroke amount, using the tip position when the stroke is reduced to the maximum as a reference. Of course, the reference may be set at any intermediate position between the maximum stroke extension and the minimum stroke reduction. The second calculation is a process of associating the tip position obtained in this manner with an analog signal corresponding to the rotation angle to obtain X and Y coordinate values for display. These calculations are naturally performed in real time. By continuously inputting the values in the X direction and Y direction indicating the locus of the tip position obtained by the display calculator 115 to the over cutter display 108 (for example, a memory scope), as shown in FIG. The locus of the tip can be drawn on the display screen 108A. On the display screen 108A, Ta is the tip trajectory,
Tb is the current value of the trajectory. In the figure, an example of clockwise rotation is shown as indicated by a dotted line (this dotted line is not displayed and is for explanation purposes only).
The trajectory Ta shows a so-called over-digging shape. In addition, when displaying, the following artificial operations are added to make it easier to observe the over-excavation shape. Compared to the distance from the center point of the tip trajectory to the tip position, the amount of variation in the tip trajectory due to variation in stroke amount due to expansion and contraction is relatively small. Therefore, by calibrating only the trajectory of over-digging to be larger than the actual value, detailed observation of the over-digging state becomes possible. This calibration is performed by changing the gain setter to the display 10.
8 or by incorporating it into the arithmetic unit 115. According to the gain setting device, the magnitude of the trajectory of over-digging can be freely adjusted. The trajectory needs to be cleared every time it makes one rotation (360 degrees). This can prevent overlapping trajectories. In the figure, the memory erase circuit 107 has this role, and the memory erase circuit 107 has the role of
0°), a reset signal is sent to the display 108 to erase the displayed value before that point. FIG. 10 shows an embodiment of a panel in which an operation section and a display screen are housed on an integrated panel.
On this panel, there are a display screen 108A, an operation button (or operation display lamp) 104A for the forward/reverse setting device 104, an operation button 109A for the digital angle setting device 109, and an operation button (or operation display lamp) 116A for the mode setting device 116. , stroke upper limit setter 113, stroke lower limit setter 11
4 display sections 113A and 114A are provided. Next, a description will be given of control for automatically expanding and contracting the overcutter in conjunction with its rotational position. There are two types (modes) of expansion and contraction in conjunction with the rotational position of the overcutter. The first mode is 1
The second mode is a case where there is one expansion and contraction during one rotation, and the second mode is a case where there is two expansions and contractions during one rotation. The mode setter 116 determines which of these two modes to use. First, control in the first mode will be described. This first mode is an example as shown in FIG. In FIG. 8 (FIG. 10), mode setting device 1
16 to set "1". The forward/reverse rotation setting device 104 is used to set the rotation direction of the over cutter to either "forward" or "reverse". However, this
It can also be automatically input from the control device of the shield tunneling machine. The digital angle setting device 109 is used to set the angle of the desired start position of expansion and contraction. In the case of "Mode 1", points A and C during forward rotation in Fig. 12,
Set four points, A' and C' points for reversal. other than this,
In order to control the stroke amount, an upper limit value SH. and a lower limit value SL. are set by a stroke upper limit setter 113 and a lower limit setter 114. The comparison calculator 105 is the digital angle calculator 1
The digital signal corresponding to the rotation angle of 03, the digital signal of the setting angle of the digital angle setting device 109, and the forward or reverse instruction signal of the forward/reverse setting device 104 are taken in, and the expansion/contraction control signal of the over cutter is set. Output to 111. Setting of the over cutter expansion/contraction control signal by the comparator 105 is performed by the following process. The comparison calculator 105 is
It has an internal register that temporarily stores the set angle given by the digital angle setter 109.
Furthermore, it has a comparator. This comparator converts the digital signal corresponding to the actual rotation angle of the over cutter from the digital angle calculator 103 (hereinafter referred to as rotation angle) and the digital setting angle stored in the register into the positive or reverse direction of the forward/reverse setting device 104. Based on the instruction of the reverse rotation command signal, successive comparisons are made along the rotation direction. To explain using the example shown in FIG. 12, A and C are stored in the register. Now, if a clockwise rotation command is issued and the tip of the overcutter is located at point M, the comparator outputs a reduction maintenance signal to keep the stroke of the overcutter reduced until point A is reached. When point A is reached, the comparator issues a stroke extension signal. This stroke extension signal becomes an extension amount setting signal for the overcutter via the computing unit 110, and is applied to the drive system of the overcutter, so that the overcutter is extended. B→C
The state of the amount of extension is maintained during this period, and when the point C is reached, the comparator generates a stroke reduction signal. This stroke reduction signal is passed through the arithmetic unit 111 and becomes a signal for setting the amount of contraction of the overcutter, and is applied to the overcutter drive system to reduce the overcutter. The arithmetic unit 110 applies a restriction so that the stroke extension output is not greater than the upper limit value of the upper limit setter 113, and the arithmetic unit 111 is used to impose a restriction so that the stroke reduction output is not less than the lower limit value of the lower limit setter 114. It adds Therefore,
The determination of point B and point D will be automatically performed by this arithmetic unit. Next, the reduced state is maintained from point D to point A. The above operating situation will be comprehensively explained again using FIG. 11. Consider the case in figure A, where the overcut is rotating in the normal direction. As the "forward rotation" signal is input and the rotation occurs, the set angle A of the extension signal
When the point is reached, an overcut signal is output and the overcut begins to extend. When it continues to extend while rotating and reaches the set stroke upper limit SH., the extension signal stops. This point becomes B. The over cutter continues to rotate in this state, and when the set angle of the shrinkage signal reaches point C, a shrinkage signal is output. As a result, the overcut begins to shrink, and stops shrinking when it reaches the set lower limit stroke value SL. This point becomes D. In this way, one cycle of "mode" and "normal rotation" is completed. If the settings remain unchanged, the above state will be repeated for each point. As a result, an over-excavation shape as shown in FIG. 12 is obtained. A
Various shapes in "Mode 1" can be obtained by appropriately changing the point, C point, and SH.SL. still,
l is the upper and lower limit stroke expansion/contraction amount. The flow of these signals is as shown in FIG. If you want the over cutter to reverse as shown in figure B, input the "reverse" signal and the set A′,
The same operation as above occurs at SH (B'), C', and SL (D'), and the same shape as in the case of forward rotation can be obtained. As shown in FIG. 13, a case in which there is expansion and contraction twice during one rotation (this will be referred to as "mode 2") will be explained. By setting "2" in the mode setter 116, and in the angle setting device 109, A, C,
Perform the same operations as in "Mode 1" except that you need to set 8 points (see Figure 13): points E and G and points A', C', E', and G' at the time of reverse rotation. As a result, an over-excavation shape as shown in FIG. 13 can be obtained. As described above, by appropriately setting numerical values and signals in the mode setting device 116, forward/reverse setting device 104, digital angle setting device 109, and stroke upper/lower limit setting devices 113, 114, any practically required values can be set. It becomes possible to easily obtain an over-excavation shape. Next, the relationship between control using set values and display will be described. The figure displayed by the overcutter display 108 is the locus of the tip position of the overcutter. The locus of this tip position is the setting device 109, 104, 1
13, 114, and 116 or depending on the setting mode. Therefore, by observing the locus of the tip position of the overcut indicator 108, it is possible to know the over-digging state in accordance with the above setting conditions. The results of observation of displayed figures are actively used as described below. According to the displayed graphic, it can be determined whether the setting conditions such as the over-digging shape and the over-digging position are suitable. If the setting conditions such as the shape and the over-digging position are suitable, the over-digging is continued as is, or the setting conditions for the over-digging are given. If the setting conditions are not suitable, it is possible to determine which factors in the setting conditions are not suitable, and new setting conditions can be created and set. By observing the displayed figure, you can understand the condition of the ground in addition to the conditions set by the setting device, and it can be used to judge whether or not the excavation route can be successfully passed, the overall operating condition of the shield excavator, the condition of the ground, etc. You can also get In the above embodiments, the display is analog and the control is digital, but it may be entirely analog or entirely digital. This all-digital system includes the use of microcomputers and CRT display devices. Further, other predetermined positions may be displayed instead of the tip position of the overcut. Further, the control based on the upper and lower limit values is performed by a computing unit 110,
111, but it is also possible to use a direct mechanical restriction mechanism for upper and lower limit values. Display 108
By importing the setting conditions of the setting device 109, etc. as input data and displaying them on the screen at the same time as real measured values, it is possible to directly compare the setting conditions with the actual state and check the operation of the detection system. It is also possible to realize roles such as According to the present invention, 1. The position of the tip of the overcut can be displayed two-dimensionally on a plane, taking into account its expansion and contraction, and the shape of the overcut can be seen directly, allowing accurate overcutting. . 2. Just by setting numerical values through simple operations on the operation panel, almost all over-excavation shapes that are practically required can be easily created.

[Brief explanation of drawings]

Figure 1 is a cross-sectional side view of a conventional shield tunneling machine.
Figures 2 and 3 are explanatory diagrams of the over-digging shape, Figure 4 is a system diagram of stroke detection, Figure 5 is a cross-sectional side view of another shield excavator, Figure 6 is an example configuration of the display section, Fig. 7 is an explanatory diagram of its operation, Fig. 8 is an embodiment of the present invention, Fig. 9 is an example of a display screen, Fig. 10 is an example of panel configuration, and Fig. 11 A and B are explanatory diagrams of the tip trajectory. , FIG. 12, and FIG. 13 are diagrams showing the shape of over-digging. 101... Over cutter position detector, 102
... Stroke detector, 105 ... Comparison calculator,
109... Digital angle setter, 108... Over cutter display, 115... Display calculator.

Claims (1)

[Scope of Claims] 1. A shield main body, a cutter head rotatably installed in the front part of the shield main body, and an overcutter installed in the cutter head that expands and contracts with a jack. In a shield excavator that excavates a face by extending and contracting a vine, an over-cutter position detector that continuously detects the rotational position of the over-cutter, and a stroke detector that continuously detects the amount of expansion and contraction of the over-cutter. , a display calculator that calculates the two-dimensional coordinate values of the overcutter based on detection signals from the overcutter position detector and the stroke detector, and a display screen that displays the trajectory of the overcutter based on the output signal from this calculator. A monitoring/control device for a shield excavator, characterized by being provided with an overcut indicator as shown above. 2. The monitoring and control device for a shield excavator according to claim 1, wherein the locus of the overcut is a tip locus of the overcut. 3. A shield main body, a cutter head rotatably installed in the front part of the shield main body, and an over cutter installed in the cutter head that expands and contracts by means of a jack; A shield excavator for over-excavating a face includes an over-cutter position detector that continuously detects the rotational position of the over-cutter, a stroke detector that continuously detects the amount of expansion and contraction of the over-cutter, and an over-cutter position detector. a display calculator that calculates the two-dimensional coordinate values of the overcut based on the detection signals from the stroke detector and the stroke detector; A vine display device, an angle setting device for setting the rotational position at which the overcut vine should start extending and a rotational position at which reduction should start, and a stroke setting device for setting the upper and lower limit values for the extension and contraction of the overcut vine. , the output signal of the over cutter position detector and the output signal of the angle setting device are compared and calculated, and the output signal of the stroke detector and the output signal of the stroke setting device are compared and calculated to extend/retract. - A monitoring control device for a shield excavator, characterized in that it is provided with a comparison calculation means for outputting a stop signal.