JP2869244B2 - Control device for shield machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control apparatus for controlling a direction of a shield machine having a center folding mechanism.

[0002]

2. Description of the Related Art Conventionally, the center folding operation of a shield machine has all relied on the operation of an operator. The operator operates the valve of the hydraulic circuit of the folding jack, which is the actuator of the folding mechanism, while monitoring the meter display of the folding angle on the operation panel or the reading of the scale installed in the shield machine. The shield main body is bent until the designated folding angle is reached, and one ring is usually dug while maintaining the folding angle.

[0003]

In the construction of a tunnel with a sharp curve, as shown in FIG. 18 (a), when the shield body 1 is bent between the front trunk 1A and the rear trunk 1B and excavated. The ground reaction force f acting on the side surface of the front trunk 1A generates a component force fx toward the inside of the curve, and the component force fx causes the moment M1 generated in the shield main body 1 to be added to the moment M2 caused by pushing the shield jack halfway. It becomes easier to turn. In addition, since the surplus amount s may be small, the loosening of the ground can be minimized. On the other hand, when the center folding is not performed, as shown in FIG. 18B, the moment for bending the shield main body 1 is only the moment M2 due to the one-side pushing of the shield jack. s also needs to be larger. As described above, in the case of sharp curve construction, the shield body needs to be folded in the middle, and the state of the folded middle is a major factor in determining the direction of excavation.

[0004] The half-fold angle is determined by calculating the required amount from the construction curvature, but the determined half-angle is not always optimal for the construction conditions due to the magnitude of the ground reaction force, the bending of the shield machine, and the like. It may not be an angle. Also, when the shield body is restrained by the surrounding ground, it is not possible to obtain the required angle at the start of the excavation, or the angle changes during excavation due to internal leaks of the jack. There is also. For these reasons, the following problems occur in the construction work.

[0005] The bending angle cannot be made sufficiently large because the angle of the center folding is too small.

[0006] The bending angle is too large and the construction curvature becomes larger than necessary.

[0007] Operators typically address the above problem by modifying the pattern of the shield jack used.
However, there are cases where it is not enough to correct the jack pattern alone. Even in such a case, the excavation of one ring is completed while maintaining the half-fold state set at the start of excavation, and the angle of halfway is corrected at the start of excavation of the next ring Often do.

This is partly because it is cumbersome to change the angle of the folding halfway during the excavation, but also because the operator does not quantitatively grasp the excess or deficiency of the angle of the folding, the shield jack is not provided. It is conceivable that the determination of whether or not the angle of the folding half can be dealt with by the pattern correction alone may be delayed, and one ring excavation may be completed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to automatically determine whether the angle of a half-bending angle cannot be dealt with only by correcting the pattern of a shield jack, or during excavation with the assistance of an operator. It is an object of the present invention to provide a shield machine control device capable of making corrections in the above-described manner and obtaining a construction curvature as planned.

[0010]

According to the first aspect of the present invention,
As shown in FIG. 1, in a control device for controlling the excavation direction of a shield excavator having a center folding mechanism, the control device is used in accordance with a deviation between a target control amount and an actual control amount of direction control during excavation. When the jack pattern control means for correcting the pattern of the shield jack and the jack pattern control means cannot meet the pattern correction request, determine the degree of excess or deficiency of the actual control amount with respect to the target control amount,
A half-fold angle change instruction unit that outputs a half-fold angle change instruction value corresponding to the determination result, and the half-fold angle control amount is determined based on the half-fold angle change instruction value and the half-fold state measurement value of the shield. And a control unit for changing a folding angle, which controls a valve of a hydraulic circuit that operates the actuator of the folding mechanism until the change instruction value is reached.

According to a second aspect of the present invention, there is provided a control apparatus for controlling the direction of excavation of a shield excavator having a center folding mechanism, as shown in FIG. A jack pattern control means for correcting the pattern of the shield jack used in accordance with the deviation from the control amount, and a half angle angle for the operator when the jack pattern control means cannot satisfy the pattern correction request. And a middle angle angle excess / shortage warning means for warning of excess / shortage.

[0012]

According to the first aspect of the present invention, when the jack pattern control means cannot respond to the pattern correction request during excavation, the half angle angle change instruction means sets the actual control amount to the target control amount for the direction control. The degree of excess or deficiency is determined, a half-fold angle change instruction value corresponding to the determination result is output, and the half-fold angle change control means operates the actuator of the half-fold mechanism until the half-fold angle change instruction value is reached. By controlling the valve of the hydraulic circuit, the correction of the half angle required for achieving the target control amount of the direction control is automatically performed during the excavation.

According to the second aspect of the present invention, if the jack pattern control means cannot respond to the pattern correction request during the excavation, the half-fold angle excess or shortage warning means informs the operator of the half-fold angle. By warning the excess or deficiency, the operation of the operator is supported so that the correction of the half angle required for achieving the target control amount of the direction control can be performed during the excavation.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows an example of a shield machine to which the present invention is applied. This example is a shield excavator of a type in which the shield body 1 is divided into a front body 1A and a rear body 1B and then the shield jack 7 is supported by the body 1B, and the type of shield is muddy. The front head 1A has a cutter head 2,
The cutter drive motor 3, the agitator 4, the mud pipe 5, and the drain pipe 6 are provided. At the time of excavation, the cutter head 2 is rotated to excavate the ground, and the muddy soil supplied by the mud pipe 5 is formed. The material and the excavated earth are stirred and mixed with the agitator 4,
The shield jack 7 supported by the rear trunk 1B is extended while being transported rearward by the mud pipe 6, and the segments 8 assembled in the rear trunk 1B are propelled as reaction force receivers. Front torso 1
Between the A and the rear trunk 1B, a center folding jack 9 which is an actuator of a center folding mechanism is attached. In addition, the cutter head 2 is equipped with a copy cutter 10 for performing extra excavation during curve construction. Assembling of segment 8 is performed on rear body 1
This is performed by the erector 11 mounted on B.

FIG. 3 shows a state in which segment assembly for one ring has been completed and the next ring is to be dug. At this time, there is a margin x for assembling the segment between the spreader 12 provided at the rod end of the shield jack 7 and the face side end surface of the segment 8, and this is the idle pushing of the shield jack 7 before the start of excavation. It becomes a stroke.

FIG. 4 shows an example of the arrangement of the shield jack 7 and the center folding jack 9 on the IV-IV section of FIG. 3. In this example, ten shield jacks and eight center folding jacks are provided. The shield main body 1 is arranged symmetrically with respect to a horizontal center line X and a vertical center line Y (subscripts indicate respective jack numbers). The direction control of the shield is usually performed by selecting the number and position (jack pattern) of the shield jacks 7 to be used. The selection of the jack pattern to be used for controlling the direction of excavation of the shield in this way is referred to as jack pattern control in this specification. In addition, the angle at which the shield body 1 is bent (the angle between the axes of the front body 1A and the rear body 1B).
Are center folding jacks 9-1 to 9-4 and 9
It is determined by the stroke difference of -5 to 9-8. In this specification, controlling a valve of a hydraulic circuit that operates a half-folding jack to set or change the half-folding angle according to an instruction value is referred to as half-folding control.

FIG. 5 shows an example of the system configuration of the jack pattern control system. In FIG. 5, a sequencer 13 directly controls a digging actuator including a cutter driving motor 3, an agitator 4, and a system jack 7. When digging, a jack pattern control signal from an external control device 14 and a jack push from an operation panel 15 are pushed. The shield jack 7 is selectively operated by an operator operation signal for instructing the operation to perform propulsion. The jack pulling operation at the time of segment assembly and the jack emptying operation at the start of excavation are performed by an operator operation signal from the operation panel 15. The start and stop of the cutter drive motor 3 and the agitator 4 are also performed by an operator operation signal from the operation panel 15. The external control device 14 receives signals from the sequencer 13 indicating the actuator operation state such as the presence or absence of cutter rotation, the number of jacks used, the jack push / pull state, and the like, and various measuring instruments (gyrocompass, pitching) installed in the shield machine. Meter, shield jack stroke sensor, etc.) 16
The signal transmitter 17 amplifies and converts the control state measurement data such as the shield excavation direction (azimuth angle, pitching angle) and shield jack stroke from the external control device 14.
Sent to Based on these input information and the control target values of the directional control stored in the target value file 18 (the target azimuth angle, the target pitching angle, etc. at the end of the excavation of one ring), the external control device 14 sets the initial jack at the start of the excavation. The pattern is determined and the jack pattern is corrected during the excavation. The external control device 14 is connected to a pattern database 19 for initial jack pattern determination and a jack database 20 for jack pattern correction.

An external control device 14 installed in a control room or the like on the ground communicates with a later-described half-fold controller and copy cutter controller in addition to the jack pattern control function described above, and collects data during excavation. An excavation management function is provided, such as transferring measurement data to the measurement data file 21 as management data every time one ring excavation is completed.

FIG. 6 shows an example of the system configuration of the hydraulic circuit of the center folding jack and the center folding control system. The center folding jacks 9-1 to 9-4 and 9-5 to 9-8 shown in FIG.
Receives the supply of pressure oil from the hydraulic pump 24 via the half-fold operation valves 22 and 23 each composed of a 4-port electromagnetic switching valve, and performs a push-pull operation. In the past, the operator had to switch the half-fold operation valve using a cam switch or the like on the operation panel while monitoring the meter display and scale reading of the half-fold angle. In this embodiment, this half-fold operation is automated. For this purpose, a center folding controller 25 and a sequencer 26 are provided, and the switching solenoids a and b of the center folding operation valves 22 and 23 are selectively excited by an output signal of the sequencer 26 based on the control output of the center folding controller 25. ing. The half-fold controller 25 is connected to the external control device 14 shown in FIG.
The transmission of the center folding angle instruction value, the change instruction value, the half folding set, the change instruction, and the like is performed to 5, and the half folding controller 25 transmits the middle folding set, the change end, and the like to the external control device 14. Further, the half-fold controller 25 receives the half-fold state measurement data from the half-fold stroke sensor 27 for measuring the half-fold angle of the shield main body and the pressure sensor 28 for measuring the operating oil pressure of the half-fold jack. , 30.

FIGS. 7 and 8 show an example of a control flow in a shield machine in which a shield jack is supported by a rear trunk.

Before starting the excavation, the center folding is set by the following program on behalf of the operator. The procedure for setting the half-fold when shifting from straight line construction to curve construction starts by inputting a pre-calculated half-fold angle instruction value to the half-fold controller 25 (step 101). There are a method of inputting the half-bend angle instruction value online from the external control device 14 and a method of manually inputting the half-bend controller 25 directly. In the present embodiment, in order to automate the excavation by the copy cutter, the excavation instruction value is similarly input to a copy cutter controller (not shown) (step 102).
Excavation control is started simultaneously with the rotation of the cutter (step 10)
3). Then, the external control device 14 (or the operation panel 15)
The middle folding controller 25 selects the middle folding operation valves 22 and 23 through a sequence 26 (step 104) and excites the valves (step 10).
5) is performed, and based on the half-fold angle instruction value input in advance and the measurement data of the half-stroke stroke sensor 27 and the pressure sensor 28, whether the control amount of the half-fold angle has reached the instruction value (step 106). It is determined whether the operating oil pressure has exceeded the set value (Step 107), and the left and right groups are controlled until the control amount of the folding angle reaches the indicated value or the operating oil pressure rapidly increases due to the restraining force received by the shield body even within the indicated value. Of the folding jacks 9-1 to 9-4 and 9-5 to 9-8 are selectively operated. Generally, the operation speed of the half-fold jack is slow,
High accuracy of the folding angle is not required (for example, ± 0.2
Therefore, the sequence control for turning on and off the hydraulic valve is sufficient for the center folding control.

The above valve operation is completed (step 10).
8) When the fact is received from the center folding controller 25,
The external control device 14 determines an initial jack pattern (step 109).

The initial jack pattern is determined, for example, by calculating a target azimuth angle θh and a target pitching angle θv in one ring excavation as described in Japanese Patent Application No. 3-65949. Shield azimuth θ
h ′, target control amount (horizontal) Δθh = θh−θh ′ calculated from pitching angle θv ′, target control amount (vertical) Δ
Using θv = θv−θv ′ as a basic parameter, the degree of single pressing in each of the horizontal and vertical directions required to achieve the target control amount by a fuzzy control rule and a membership function determined in advance (the degree of single pressing = the jack used) Determine the sum of the distance from the shield center line / the number of jacks used, where the longest distance from the shield center line of the jack is 1), and use the corresponding degree of required horizontal push and vertical push. Calculate the jacking pattern in advance for each jack pattern in the horizontal and vertical directions for all jacking patterns,
This is performed by searching from the registered pattern database 19.

After the initial jack pattern is determined, excavation is started (step 110). Then, it is determined whether or not the half-fold setting has been completed when the specified stroke has been excavated (steps 111 and 112). If the half-fold angle has not reached the designated value, the excavation is temporarily stopped (step 113) until the half-fold setting is completed. Steps 105 to 112 are repeatedly executed. After that, in order to cope with the deviation between the target control amount and the actual control amount of direction control during excavation, the jack pattern is modified at specified intervals (for each check stroke) until the shield jack reaches the end stroke and excavation ends Control is performed (steps 114 to 119).

As described in the above-mentioned Japanese Patent Application No. 3-65949, for example, the jack pattern is corrected from the control state measurement data of the direction control taken for each check stroke with respect to one ring excavation end stroke. The excavation rate α indicating how much excavation has been performed, the control amounts Δθhi and Δθvi indicating how many times the shield has been controlled in each of the horizontal and vertical directions from the start of excavation of one ring, and the current jack pattern from the start of excavation of one ring. When maintained, the control prediction amounts θhi and θvi representing how many control amounts can be obtained in each of the horizontal and vertical directions are calculated, and these values are used as parameters by a fuzzy control rule and a membership function determined in advance. Determine the degree of single-sided pressing to be corrected in each of the horizontal and vertical directions. If it is determined that it is necessary to correct the jacks, the jacks corresponding to the corrected one-sided pressing degrees in the horizontal and vertical directions are changed in the horizontal and vertical directions when the jacks are added and removed in advance for each jack. The amount is calculated and selected by searching the registered jack database 20, and the selected modified jack is added to the current pattern (on control) or deleted from the current pattern (off control). At this time, if the jack to be controlled has already been turned on or off and there is no controllable correction jack even though the pattern needs to be corrected, further improvement of the control state can be expected. Absent. In this case, in the present embodiment, the folding angle is changed (step 120).

FIG. 9 and FIG. 10 show an example of the flow of the change of the folding angle. Here, it is first determined whether the need to change the half-bend angle has arisen due to an excessive control amount of the direction control or due to an insufficient control amount (step 121). Thereafter, a level evaluation for determining the degree of excess or deficiency of the control amount is performed (steps 122 and 123 in FIG. 9 and steps 127 and 12 in FIG. 10).
8), determine the half angle control amount corresponding to the result (steps 124 to 126 in FIG. 9 and step 1 in FIG. 10)
29-131). The relationship between the level evaluation and the half-fold angle control amount is determined in advance as shown in Table 1 below, for example, and is incorporated in the program.

[0028]

[Table 1]

Here, the determination of the excess or deficiency of the control amount of the direction control and the level evaluation are, for example, as shown in FIG. 11, a control calculated based on the control amount (actual control amount) measured in the i-th check stroke. This is performed by comparing the predicted amount with the target control amount at the end of excavation. The control prediction amount is a control amount obtained as a result of performing linear or non-linear prediction from the current control state. FIG. 11 shows an example in which linear prediction is performed from the control state at the i-th check stroke.

After determining the above-described half-fold angle control amount, the external control device 14 transmits the determined half-fold angle control amount as the half-fold angle change instruction value to the half-fold controller 25 and instructs the half-fold angle change. , Receiving this, Midori controller 2
5 executes the center folding control (step 132). The procedure of the half-fold control performed here is the same as the control procedure at the time of the half-fold setting (steps 104 to 108). -1 to 9-4 and 9-5 to 9-8 are selectively operated. When this center folding control is completed and the fact is received from the center folding controller 25, the external control device 14 proceeds to the next step of the control flow.

As described above, according to the present embodiment, it is possible to automatically perform the setting of the center folding at the start of excavation and the change of the center bending angle corresponding to the excessive or insufficient control amount of the direction control during excavation by the program. .

In the case where the off-line operation support is performed by a half-fold angle excess or shortage warning instead of the control of the half-fold angle change, the flow is as shown in FIG. 12 and FIG. FIG. 12, FIG.
In 3, the "change of the folding angle" (step 120) in FIGS. 7 and 8 is replaced with the "warning output" (step 133). FIG. 14 shows an example of a monitor screen display by this warning output. In this example, a half-fold state model display 31 of the shield, a control state message 32 such as “the half-angle angle is out of the indicated value”, a half-angle angle indicated value, the current half-angle angle, the left stroke, The data display 33 includes a right stroke, a copy cutter remaining excavation amount, and the like. From this screen display, the operator recognizes whether the half-fold angle is excessive or insufficient, manually inputs a half-fold angle change instruction value to the half-fold controller 25, and By giving the half-bend angle change instruction, it is possible to correct the excess or deficiency of the half-bend angle during excavation. The content of the warning is not limited to the above example, and may be any content that supports the operator operation.

FIG. 15 shows another example of a shield machine to which the present invention is applied. In this example, the shield body 1 is the front body 1
A, the middle trunk 1B and the rear trunk 1C are divided into three parts.
The shield jack 7 is supported by the front trunk 1A, and the center jack 9 is mounted between the front trunk 1A and the rear trunk 1C.
The shield is of earth pressure type, and a screw conveyor 34 for discharging the earth is provided on the front body 1A.

FIG. 16 shows an example of a system configuration of a hydraulic circuit and a center folding control system of the center folding jack when the present invention is applied to a shield machine in which the shield jack is supported by the front body as described above. As in FIG. 6, in order to selectively supply the pressure oil from the hydraulic pump 24 to the center folding jacks 9-1 to 9-4 and 9-5 to 9-8 for each of the left and right groups, a four-port solenoid-operated switching valve is used. The center folding operation valves 22 and 23 are provided. Further, middle folding release valves 36 and 37 each composed of a normally closed two-port electromagnetic switching valve are connected between the push-side and pulling-side ports of each center folding jack and the return oil pipe 35, and the center folding operation valves 22 and 23 and middle folding release valve 3
6 and 37 are switched by an output signal of the sequencer 26 based on the control output of the center folding controller 25.

The control flow of the shield machine in which the shield jack is supported by the front fuselage is basically the same as that of the rear fuselage support type, but the valve operation of the center folding set is different. The flow up to the end stroke determination (step 114) is replaced by FIG. FIG.
In the flow shown in Fig. 7, when moving from straight line construction to curved line construction,
First, the center folding angle instruction value is input to the center folding controller 25 (step 201). As described above, there are a method of inputting the half-fold instruction value online from the external control device 14 and a method of manually inputting the half-fold controller 25 directly.

In response to an instruction to set the center fold from the external control device 14 or the operation panel 15, the center fold controller 25 excites the center fold release valves 36 and 37 through the sequencer 26,
The valve is opened (step 202). Thereafter, the excavation is started through the procedure of input of an instruction for excavation (step 203), rotation of the cutter, start of excavation control (step 204), and determination of an initial jack pattern (step 205) (step 2).
06). When the center folding release valves 36 and 37 are opened, the center folding jacks 9-1 to 9-8 are all in a free state, so that after excavation starts, the shield body 1 is bent along the tunnel line. Here, the half-fold controller 25 determines whether or not the control amount of the half-fold angle has reached the indicated value from the measurement value of the half-stroke stroke sensor 27 (Step 207).
When the indicated value is reached, the center folding release valves 36 and 37 are closed to stabilize the center folding angle (step 208). Thereafter, the control flow shifts to the end stroke determination (step 114) in FIGS.

The change of the half-fold angle is performed by changing the half-fold operation valve 22,
23, and the center jacks 9-1 to 9-4 and 9-5 for each of the left and right groups until the control amount of the half-fold angle reaches the half-fold angle change instruction value input to the half-fold controller 25.
This is performed by selectively operating 9-8.

[0038]

According to the first aspect of the present invention, when the jack pattern control means cannot respond to the pattern correction request during excavation, the degree of excess or deficiency of the actual control amount with respect to the target control amount of direction control. , The correction of the folding angle is automatically performed according to the above, and the target control amount of the direction control can be more accurately achieved.

According to the second aspect of the present invention, when the jack pattern control means is unable to respond to the pattern correction request during excavation, the operator is warned of an excessive or insufficient half-fold angle, thereby allowing the operator to operate the apparatus. , The correction of the folding angle is performed without delay, and the target control amount of the direction control can be more accurately achieved.

Further, according to the third aspect of the present invention, it is possible to automate a half-folding set at the start of excavation, which has been conventionally performed by an operator, so that the burden on the operator can be reduced.

[Brief description of the drawings]

FIG. 1 is a functional block diagram corresponding to claim 1;

FIG. 2 is a functional block diagram corresponding to claim 2;

FIG. 3 is a longitudinal sectional view showing an example of a shield machine to which the present invention is applied.

FIG. 4 is a diagram showing an example of the arrangement of a shield jack and a center folding jack on the IV-IV section of FIG. 3;

FIG. 5 is a block diagram illustrating an example of a system configuration of a shield jack control system.

FIG. 6 is a diagram showing an example of a system configuration of a hydraulic circuit of a center folding jack and a center folding control system.

FIG. 7 is a diagram (part 1) illustrating one example of a control flow according to the present invention;

FIG. 8 is a diagram (part 2) illustrating one example of a control flow according to the present invention;

FIG. 9 is a diagram (part 1) illustrating an example of a flow of changing a folding angle in FIG. 8;

FIG. 10 is a diagram (part 2) illustrating one example of a flow of changing the half angle in FIG. 8;

FIG. 11 is a graph showing a control state of direction control at the time of jack pattern correction.

FIG. 12 is a diagram (part 1) illustrating another example of the control flow according to the present invention.

FIG. 13 is a diagram (part 2) illustrating another example of the control flow according to the present invention.

FIG. 14 is a diagram showing an example of a screen display by a warning output in FIG. 13;

FIG. 15 is a longitudinal sectional view showing another example of the shield machine to which the present invention is applied.

FIG. 16 is a diagram showing another example of the system configuration of the hydraulic circuit of the center folding jack and the center folding control system.

FIG. 17 is a diagram showing still another example of the control flow according to the present invention.

FIGS. 18A and 18B are diagrams showing the effect of the half-folding of the shield. FIG. 18A is a state diagram at the time of half-folding, and FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Shield body, 7 ... Shield jack, 9 ... Center folding jack, 14 ... External control device for jack pattern control and excavation management, 22, 23 ... Center folding operation valve, 25 ...
Half-fold controller, 27 ... Half-fold stroke sensor, 28
... pressure sensors, 36, 37 ... center release valve, 104 ~
108, 112, 113, 202, 207, 208... Control procedures corresponding to the half-fold setting control means, 114 to 11
9 ... Control procedure corresponding to jack pattern control means, 1
21 to 131: a control procedure corresponding to the half-fold angle change instructing means; 132, a control procedure corresponding to the half-fold angle change control means; 133: a control procedure corresponding to the half-fold angle excessive / insufficient warning means.

──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Hitoshi Takahashi 650, Kandamachi, Tsuchiura-shi, Ibaraki Pref. Hitachi Construction Machinery Co., Ltd. Tsuchiura Plant (58) Fields investigated (Int. Cl. ⁶ , DB name) E21D 9/06 301

Claims (3)

(57) [Claims] A control device for controlling the direction of a shield machine having a half-folding mechanism, comprising: a shield jack used in accordance with a deviation between a target control amount and an actual control amount of direction control during excavation. When the jack pattern control means for performing pattern correction and the jack pattern control means cannot satisfy the pattern correction request, the degree of excess or deficiency of the actual control amount with respect to the target control amount is determined, and the determination result is corresponded. A half angle change instruction means for outputting a half angle angle change instruction value, and a half angle angle control amount based on the half angle angle change instruction value and the half angle state measurement value of the shield until the control amount of the half angle angle reaches the change instruction value. A control device for a shield excavator, comprising: a control unit for changing a folding angle, which controls a valve of a hydraulic circuit that operates an actuator of the folding mechanism. 2. A control device for controlling the direction of a shield excavator having a center folding mechanism, comprising: a shield jack for use in correspondence with a deviation between a target control amount and an actual control amount of direction control during excavation. Jack pattern control means for performing pattern correction; and half-fold angle excess / deficiency warning means for warning an operator of an excessive or insufficient half-fold angle when the jack pattern control means cannot satisfy the pattern correction request. A control device for a shield excavator, comprising: 3. The actuator of the half-fold mechanism is operated based on the half-fold angle instruction value input at the start of excavation and the half-fold state measurement value of the shield until the half-fold angle control amount reaches the instruction value. The control device for a shield machine according to claim 1 or 2, further comprising a control unit for setting a half-fold setting for controlling a valve of the hydraulic circuit.