JP3419608B2 - Segment assembly method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield machine
Tunneling segments imported into
The present invention relates to a method for assembling a segment. [0002] In recent years, tunnels have been constructed by excavating the ground.
In shield construction methods, shield excavators are
Although extensive improvements have been made,
As always, many parts rely on the skills of workers.
In order to automate shield construction,
Automated dressing is an important issue. So this
The segment to be assembled from
) Is transported by the transport device, and the assembly segment
The sheet is gripped by the erector and automatically positioned.
Extend the shield jack installed on the machine
The assembly segment to the existing segment ring segment
Bolts and nuts in this state.
Assembling segment to existing segment using fastening machine
By inserting bolts and temporarily tightening, multiple segment
Assembly from bottom to top
And finally tighten the bolts to complete the segment
Segment assembly device that completes the assembly of the ring
Has been developed and is being provided for implementation. [0003] For example, an assembly segment is connected to an existing segment.
Japanese Patent Application Laid-Open No. 4-2136
No. 99 is disclosed. This prior art
In addition, the positioning of the assembly segment is performed in two stages,
First, in the first stage, the assembly input to the controller in advance
From the design / assembly position / posture of the segment and the coarse position correction amount,
Calculates the target position / posture of the segment gripper of the erector
In accordance with the target position / posture,
Coarsely positioning the assembly segment by moving the
You. Next, in the second stage, three sets of light projections installed on the erecta
Assembly using a visual sensor consisting of a display and a TV camera.
Existing in the tunnel axis direction
Two points at the boundary with the segment along the circumferential direction of the tunnel
Location and assembly segments and the tunnel circumference
Along the tunnel axis direction with the existing segment adjacent to the direction
Illuminate the slit light from one of the projectors
And shoot the slit light image with a TV camera.
I do. And the image data from these TV cameras is
From the coordinate value of the end point of each slit light image obtained by processing
Between the assembly segment and the existing segment
Steps and gaps are detected, and existing steps and gaps are
Deviation and appearance of the assembly segment with respect to the installation segment
Force deviation, and from these deviations the target of the assembly segment
Find the correction amount for the assembly position, and
By moving the actuator of the
Fine positioning of the part. Multiple such positioning controls
By repeating the process, the segment ring is assembled
You. [0004] However, the above-mentioned
The following problems exist in the conventional technology. Generally,
When assembling the segment ring, flatten the cylindrical ring in the axial direction.
Segment of line-shaped shape (A-type segment), one end
One end tapered segment with tapered section
(B-type segment), both ends tapered at both ends
3 such as tapered segment (K type segment)
First, multiple A-type segments
Assemble in an arc shape, then join two B-shaped segments in an arc
Adjacent to the A-shaped segments located at both ends of the shape
Assembling and finally the K segment into two B segment
Using a taper between the
Do. [0005] JP-A-4-213699 described above
According to the prior art of
When trying to assemble one after another, the K-shaped segment
Space for installation is the same as the actual dimensions of the K-shaped segment
Does not accurately position the K-shaped segment
And K type segment by contacting with B type segment
Insertion becomes difficult. In the construction work,
Rubber seals between each segment to prevent infiltration of groundwater
Between each segment, for example, because
Has a slight gap, in which case the K-shaped segment
Space for installation is narrower than actual size of K-shaped segment
And the insertion of the K-segment becomes more difficult. this
When the K-shaped segment is in contact with the B-shaped segment
Segment was damaged when trying to insert with force
As a result, the sealing material is damaged. Also, a set of segments
There is also a problem that the accuracy of the setting is reduced. It is an object of the present invention to provide a
Easier insertion of tapered segments
Damage, seal material breakage, segment assembly accuracy
To provide a segment assembling method that can prevent a decrease in
It is in. Another object of the invention is to provide a final assembly
Facilitates the insertion of segments with tapered ends, and
Make the assembled segment ring into an appropriate ring shape
It is an object of the present invention to provide a segment assembling method. [0008] In order to achieve the above object,
The present invention employs the following configuration. That is, multiple seals
Excavated the ground with a shield machine having a dojack
When constructing a tunnel, the assembly segment
The shield jacket, and then
And extend the assembly segment to the existing segment.
And in this state the assembly segment and
Temporarily fastening bolts by inserting them into the existing segments
Assembles multiple assembly segments from below to above
Assemble the vertical segment ring, and finally,
To complete the assembly of the segment ring.
A plurality of assembly segments.
When assembling components from bottom to top, first
Assemble the vertical segment according to the existing segment
A first step, and after this first step, the assembly segment is moved forward.
Outside the radial direction of the segment of the existing segment ring
Assemble by shifting to the side, and finally a segment with both ends tapered
And a second step of inserting and assembling.
When assembling the segments in the process,
The fastening force of the temporary fastening is that the shield jack is released.
The size that the segment can be displaced in the direction of gravity by its own weight
Set to In the above, in the second step, the assembly segment
To the segment of the existing segment ring in the radial direction.
By assembling by shifting to the outside, both ends are tapered.
The space for incorporating the segment is
Larger than the dimensions, making it easier to insert the segment
Damage to the segment, damage to the sealing material,
Of the assembly accuracy is prevented. In the second step, segments are assembled.
When setting up the bolt, the fastening force of the bolt
When the key is released, the segment moves in the direction of gravity due to its own weight.
The size of the shield
When the jack was released, it was assembled in the second step
The segment is displaced in the direction of gravity from its assembly position,
The assembled segment ring is determined by the segment shape.
It has a round shape. Here, if the bolt fastening force is
Opening the shield jack in the same way as the temporary fastening of the bolt
When the segment is almost displaced in the direction of gravity by its own weight.
If it is not strong enough, set up the segment ring
Is completed and the shield jack is released,
Is hardly displaced from its assembly position in the direction of gravity
Therefore, in the second step, the segment of the existing segment ring
To the outside in the radial direction to position the segment.
In the method of assembling the present invention, the segment
When assembling the segments sequentially, the segment
Spreading radially outwards, resulting in segment ring
The shape gradually elongates and the top of the shield machine
The clearance gradually decreases, and finally the segment
The tring interferes with the shield body of the shield machine
I will. In the present invention, the shield jack is used as described above.
When opened, the segments assembled in the second step
Displaced in the direction of gravity, the assembled segment ring
The shape is determined by the segment shape.
The ring has an appropriate ring shape and is located above the shield machine.
Tail clearance is not reduced,
To prevent the ring from interfering with the shield body.
You. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. 1 and 2, the present embodiment
The segment assembling apparatus according to the first embodiment has an
The erector main body 12 is composed of a plurality of hydraulic shield jaws.
At the rear of a cylindrical shield body 11 having a jack 10
Is placed. The elector body 12 is roughly divided into
A swing mechanism including a ring 13 and a swing motor 16 and a suspension
Pressing mechanism including beam 21 and pressing jack 22
, The horizontal slide frame 24 and the horizontal slide jack 2
5 and the front and rear slide frame 27 and
Front and rear sliding mechanism including the front and rear slide jacks 28 and the ball
Surface frame 29 and attitude control jacks 31, 32, 3
Pitching, rolling, yawing and other postures including 3
Control mechanism, segment gripper 34 and bolt fastening device
70 (see FIG. 6). The electring ring 13 includes a shield body 11.
Outer guide roller 14 and side installed at several places on the inner circumference
Guided by the surface guide roller 15,
Via pinion 17 and ring gear 18
It is driven to turn. The electring ring 13 has two left and right arms.
Arm 19 is attached, and these arms 19
The suspension beam 21 is supported via the
Hydraulic pressing jack between arm 21 and arm 19
22 and the suspension beam 21 is
The Z-axis direction shown in FIG.
Direction). The suspension beam 21 is provided as shown in FIGS.
, The horizontal slide frame via the linear bearing 23
24, the horizontal slide frame 24 and the hanging beads
A hydraulic horizontal slide jack 25 is provided between the
The horizontal slide frame 24 is attached to the horizontal slide jaw.
As shown in FIG.
Moves in the axial direction (tunnel radial direction). The horizontal slide frame 24 is shown in FIGS.
As shown in FIG.
The front and rear slide frame 2
7 and the horizontal slide frame 24
A ride jack 28 is attached,
The arm 27 is moved horizontally by the front and rear slide jacks 28
The X-axis direction shown in FIG.
Slide back and forth in the axial direction). The spherical guide portion of the front and rear slide frame 27
27a incorporates a spherical frame 29,
Hydraulic system between the front and rear slide frame 27
Two attitude control jacks 31, 32 are attached
I have. These attitude control jacks 31, 32 are simultaneously
When stretched or contracted, the sphere as shown in FIGS.
The face frame 29 is rotated about an axis passing through the center G of the spherical surface and parallel to the X axis.
The movement of the segment gripper 34.
Used for ring control. Attitude control jacks 31, 3
2 is contracted and the other is contracted.
As shown in FIG. 4 and FIG.
Left and right around an axis parallel to the Z axis
Is used for yawing control of the segment gripper 34.
You. Also, the spherical frame 29 and the segment gripper 34
Between them, a posture control jack 33 is provided as shown in FIG.
Mounted, spherical frame 29 for hydraulic attitude control
When the jack 33 is tilted around the center axis 30 due to expansion and contraction
This movement is controlled by the pitching control of the segment gripper 34.
Used for The segment holding portion 34 is provided on the spherical frame 29.
And suspended below the erector main body 12.
The segment to be assembled
(Referred to as an assembly segment below).
It has a screw shaft 35 with a matching external thread. Ma
In addition, as shown in FIG.
Drive motor 36 to rotate 35 and drive screw shaft 35
Up and down operation with the motor 36 and the bearing bracket 37
And a lifting jack 38 to be moved.
The grout hole 43 of the assembly segment 42 is determined by the predetermined sensor.
After the screw shaft 35 is centered, the screw shaft 35 is rotated.
Projecting toward the assembly segment 42 while
After the screwing into the out hole 43 is completed, the assembly segment 42 is
Screw shaft 35 until it hits the end face of segment gripper 34
By pulling back, the assembly segment 42 is gripped. The front and rear slide frames 27 are not connected.
A tactile distance meter 60 is provided.
The segment gripper 34 grips the assembly segment 42
Before the installation, the existing
The distance L1 to the inner peripheral surface of the segment 41 is measured. Also,
The erector body 12 detects an angle of the erector rotation position.
An ejector (not shown), and the rotation position of the
Distance from the distance meter 60 to the inner peripheral surface of the existing segment 41
This system measures at the same time as L1, and those measured values are described later.
Output to the control device 52. Distance meter 60 and angle detector meter
The measured value is the tail clearance of the shield machine described later.
And used to determine correction values for positioning control.
You. Here, the tail clearance of the shield machine is
Tail skin play located behind shield body 11
G between the inner surface of the segment 11a and the outer surface of the existing segment 41
(See FIG. 2). FIG. 6 shows the segment gripper 34.
A base 73 shown in FIG.
Bolt feeder 71 and nut runner 7
2, the bolt feeder 71 and the nut runner 72
Actuating multiple hydraulic bolts (not shown)
And a bolt fastening device 70 comprising
You. This bolt fastening device 70
After positioning, extend shield jack 10 and assemble
The existing segment 42 is adjacent to the segment 42 in the tunnel axial direction.
Press it against the segment ring 41L, and in this state
Bolts incorporated in the pre-assembly segment 42
Is fed into the existing segment 41 by the tilt feeder 71
The nut to the bolt using a nut supply device (not shown).
Mounting, temporarily tightening the nut with nut runner 72
It attaches. Here, temporarily tighten the nut
The process of attaching is referred to as temporary fastening of the bolt. Of this bolt
The temporary fastening is performed in the assembly segment 42 and the tunnel axial direction.
And the existing segment 41a adjacent to the
And the existing section adjacent to the
Segment 41a and the adjacent existing segment 41b.
Place, adjacent to the assembly segment 42 in the circumferential direction of the tunnel
With two existing segments 41c
FIG. 7 shows the set segments 41a, 41b, 41c.
See the segment gripper 34 at the six locations above.
For example, four sets of bolt fastening devices 70 can be used to perform bolt fastening.
(Between the assembly segment 42 and the existing segment 41a)
One location and assembly segment 42 and existing segment 41c
The two bolts between the two are connected by a set of bolting devices 7
0) is fixed. The bolts are temporarily
After the assembly has been completed,
Fully tighten the bolts according to the operation. Further, the segment assembling apparatus of the present embodiment
As shown in FIGS. 7 and 8, three sets of projectors 44a, 44
b, 44c and TV cameras 45a, 45b, 45c
A visual sensor, a camera switch 48, and an image input device.
Device 49, an image memory 50, an image processing device 51,
Force device 55, display device 56, main body control device 52,
It has a servo control device 53 and a hydraulic control device 54
You. Light projectors 44a to 44c and television camera 4
5a to 45c are erectors schematically shown in FIG.
A rigid body (not shown) is attached to the segment grip portion 34 of the main body 12.
Has been fixed through. Therefore, the projectors 44a to 44a
4c and TV camera 45a-45c and segment grip
Relative position / posture of the part 34 and the assembly segment 42
Is the assembly segment regardless of the movement of the
G is constant during gripping. The projector 44a is an assembly segment.
Around the tunnel between the port 42 and the existing segment 41a
At one location on the boundary along the direction, the projector 44b is an assembly segment.
Around the tunnel between the segment 42 and the existing segment 41b.
At one location on the boundary along the direction,
Tunnel between the segment 42 and the existing segment 41c
A slit light is applied to each one of the boundaries along the axial direction.
Illuminate, thereby producing slit light on each segment
Images AA *, BB *, and CC * are TV cameras 45a.
To 45c. The image input device 49 is a television camera 45.
Each image data from a to 45c is cut by the camera switch 48.
Select and enter a replacement, and load it into the internal image memory 50
The image processing device 51 stores the image stored in the image memory 50.
The image data is processed to generate slit light images AA * to CC *.
Find the end point coordinates. The input device 55 is a set of segment rings.
Instructions for the execution of the stand, and the data necessary for this execution
Of the assembly sequence of the assembly segments that make up the
Because the data and segment ring have the target ring shape
Design position and attitude of the assembly segment
Data and the bolts
The data of bolt fastening force of the assembly segment at the time of temporary fastening of
Input and assembly of assembly pattern data etc. of assembly segments including
When there is more than one vertical segment
This is a device for selecting one of them, for example, keyboard
Is used. The main controller 52 controls the erector main body 12.
Control device, an instruction signal from the input device 55, image processing
End point coordinate value of slit light obtained by device 51, distance meter
Assemble segment using measured values of 60 and angle detector 61
Predetermined processing related to positioning of
Control is performed and the result is used as an electrical command signal for servo control.
Output to the control device 53. In addition, the memo of the main body control device 52
Data (not shown) input from the input device 55
Is stored. Also, the main body control device 52
At the time of temporary fastening, shield jack is attached to sequencer 8 described later.
An instruction signal for driving the driving circuit 10 is output. Display device 5
6 is tail clearance information of shield machine and group
The segment shape indicating the design position / posture of the vertical segment
indicate. The servo controller 53 is the main controller 52
Swing motor 1 of the erector body 12 in accordance with these command signals.
6 and convert electric signals into hydraulic signals
Pressing jaws of the erector body 12 via the hydraulic control device 54
Jack 22, horizontal slide jack 25, front and rear slide jack
6 axes of jack 28, attitude control jacks 31, 32 and 33
And the bolt fastening device 70 are controlled. The main body control device 52 is provided with a shield
Drilling of machines and transport of earth and sand excavated by cutters not shown
Connected to the sequencer 8 that controls the entire shield machine
The sequencer 8 is provided with the main body control device described above.
Shield jack when the instruction signal from 52 is input
Shield jack command signal for driving
Output to the safety jack controller 9
The key control device 9 controls the sequence according to the command signal from the sequencer 8.
Control the power jack 10. In addition, shield jacket
The key 10 has a built-in stroke meter 10a.
The stroke of the shield jack 10 is measured by the stroke meter 10a.
The rook is detected and sent to the sequencer 8. Next, the data stored in the memory of the main controller 52 is stored.
Design position / posture data and bolt fastening force data
Using the assembly pattern data of the assembly segment including
The segment assembling method of the present embodiment will be described. Assembly of segments in this embodiment
In FIG. 9, as shown in FIG.
Segment with parallel split shape (A-type segment) A
1, A2, A3, A4, A5, A6, A7 and one end
A taper (not shown) inclined to the direction of the tunnel axis
The segment with one end tapered (B-segment
G) B1, B2, and both ends are inclined with respect to the tunnel axis direction.
Tapered ends (not shown)
10 pieces consisting of a segment (K-shaped segment) K
A-type segments A1 to A7
Are assembled in an arc shape, and B-type segments B1 and B2 are A-type.
Assembled adjacent to segments A1 and A7, respectively,
Insert mold segment K between B-type segments B1 and B2
And assemble. At this time, assembly of each segment
Are A-type segments A4, A3, A5, A2, A6, A
1, A7, B type segment B1, B2, K type segment
Perform in the order of K. Also, the assembly segment is
On the opposite side (hereinafter referred to as the ring side)
Bolt at the place (RV in the figure)
(Hereinafter referred to as the piece side) is the existing segment and two places
It is bolted (PV in the figure). The following is an example of two assembly pattern data.
You. (1) Assembly pattern data This assembly pattern is shown in FIGS.
Individual assembly segments so that the
The bolts are positioned and the bolts are temporarily tightened.
In FIG. 10, the solid line indicates the design position of each assembly segment.
The dashed line indicates the existing location adjacent to the tunnel axis direction.
Of each existing segment forming the segment ring 41L
The position / posture is shown. The existing segment ring
41L has a substantially perfect circular shape. The positioning of the individual assembly segments is the next step.
Perform in order. In FIG. 10, first, A-type segments A2
A6 in the same order as above
Segment and tunnel circumference
To the existing segment adjacent in the direction.
You. Subsequently, the A-type segments A1 and A7 are
End surface T on the side in contact with _A1R , T _A7L Outside of
Side end S ₁₂ , S ₆₇ Radially outward (I ₁ ,
I ₇ Direction) to rotate the existing segment ring 41L.
To the existing segment in the radial direction.
You. Subsequently, the end face T of the B-shaped segments B1 and B2
_B1R , T _B2L Are the end faces of the A-type segments A1 and A7.
T _A1L , T _A7R B-type segments B1 and B2
Diameter of the existing segment of the existing segment ring 41L
Position it out of the direction. Finally K-segment
K is inserted between the B-type segments B1 and B2 for positioning.
You. At this time, the assembly segment is shown in FIG.
As shown in FIG.
A hole 42h for bolt fastening is provided to give
The assembly segment is
Of the clearance between the bolt 42v and the bolt fastening hole 42h
Within the range, the position and posture shown by the solid line in FIG.
It is decided. The temporary fastening of the bolts of the individual assembly segments
Proceed as follows. After the assembly segment has been positioned,
Extend the above-mentioned shield jack 10 and assemble the segment
To the existing segment of the existing segment ring 41L.
And press it down in this state.
Bolt and temporarily fasten it. At this time,
The temporary fastening of the bolts is performed by the bolt fastening force as shown in FIG.
U. That is, the A-type segments A2 to A6 are temporarily
When fastening, tighten the bolts on the ring side and the pieces.
A temporary fastening is performed by increasing the fastening force of both bolts
Mold segments A1, A7, B-type segments B1, B2,
When temporarily fastening the K-shaped segment K, use the bolt on the ring side.
And tighten the bolts on the piece side.
Perform temporary fastening. Here, “strong fastening power” means
It is the fastening force in conventional temporary fastening, and it is a shield jack.
10 and extend the positioned assembly segment to the existing
Gment ring 41L pressed against the existing segment
From the state, pull the shield jack 10 (open)
The assembly segment is almost displaced in the direction of gravity by its own weight.
There is no such fastening force. On the other hand, "weak fastening force"
This is because the shield jack 10 is pulled from the same state as above.
When the assembly segment is released (open)
It is a fastening force that can be displaced in the direction. Here, the A-type segments A1, A
7, B-type segments B1, B2 and K-type segment K
When approaching a perfect circle when displaced in the direction of gravity due to weight
The bolts are in a position that is shifted in the direction
There is no problem even if the bolt fastening force of the segment is weakened.
On the other hand, the A-type segments A2 to A6
At a position where the perfect circular shape is displaced in the direction
Therefore, the bolt fastening force of these segments
Even if you pull the lud jack 10, these segments
Same size as before with little displacement in the direction of gravity due to
Need to be done. As described above, the individual assembly segments and
Set K-type segment K by setting
When releasing the shield jack 10 after standing up
Are A-type segments A1, A7, B-type segments B1,
B2, K-shaped segment K is displaced in the direction of gravity by its own weight
The shape of the assembled segment ring is almost perfect
It becomes. [0036] (2) Assembly pattern data This assembly pattern is shown in FIGS.
Individual segments so that the
Positioning vertical segments and temporarily fastening bolts
It is. In FIG. 13, solid lines indicate individual assembly segments.
Indicates the design position / posture, and the broken line is adjacent to the tunnel axis direction
Existing segment that constitutes the existing segment ring 41L
Indicates the position and orientation of the
Each existing segment that composes the segment ring when standing
This shows the position and orientation of the client. The existing segment
The ring 41L has a vertically long oval shape. The positioning of the individual assembly segments is a second step.
Perform in order. In FIG. 13, first, A-type segments A1 to A1
A7 is a vertically elongated oval existing segment in the above order.
Positioning according to the ring 41L. That is, first, A
Segume when mold segment A4 is assembled into a perfect circle
Position to match the string. Then type A
The segments A3 and A5 are in contact with the A-type segment A4.
End face T _A3R , T _A5L Radial inner end S of ₃₄ , S ₄₅ Around
Radially inward (I _Three , I _Five Direction)
That is, the end surface T of the A-type segments A3 and A5 _A3R , T _A5L The diameter
Closes slightly inward and slightly misaligns the position
You. Subsequently, the A-type segments A2 and A6
End surface T on the side contacting the elements A3 and A5 _A2R , T _A6L Diameter
Inside end S _{twenty three} , S ₅₆ Radially inward (I
_Two , I ₆ Direction) to slightly close the positioning.
You. Subsequently, the A-type segments A1 and A7 are
End surface T on the side in contact with _A1R , T _A7L Outside of
Side end S ₁₂ , S ₆₇ Radially outward (I ₁ ,
I ₇ Direction) to slightly open the positioning. Next, the B-type segments B1 and B2 are
End surface T on the side in contact with the _B1R , T _B2L Diameter
Direction outer end S _B1 , S _B7 Radially outward centered on
(I _B1 , I _B2 Direction) and rotate the existing segment ring
To the existing segment of the ring 41L in the radial direction.
Position. Finally, K segment K is B type segment
B1 and B2 for positioning. Temporary fastening of bolts for individual assembly segments
Is performed by a bolt fastening force as shown in FIG. Sand
When temporarily fastening the A-type segments A1 to A7,
Of bolts on the bearing side and bolts on the piece side
And B type segments B1, B2, K type segment
When temporarily tightening the element K, tighten the ring-side bolts.
This is done by weakening the force and increasing the fastening force of the piece side bolt. This
When the bolt is tightened, the shield jack 10 is released.
Adjust so that the above difference does not change. As described above, the design of individual assembly segments
By setting the position / posture and bolt fastening force, K type
After assembling the segment K, the shield jack 10
When released, A-type segments A1 to A7 are incorrect
And the B-type segments B1, B2, K-type
Gment K is displaced in the direction of gravity by its own weight.
The shape of the segment ring thus formed is a vertically long oval. The segment ring has a perfect circular shape and a vertical shape.
The above is the assembly pattern that makes a long oval shape.
In addition, the assembly segment including the above assembly pattern
Multiple with different rotation direction and amount of bolt and bolt fastening force
Individual assembly patterns are set, and
Is stored in the memory of the main controller 52.
You. Next, the assembly segment in the main body control unit 52
FIG. 15 shows a procedure for controlling the assembly of the element 42. here,
Individual sets so that the segment rings are almost circular
Position the vertical segment 42 and temporarily tighten the bolts
Shall be. First, in step 90, the input device 55
Start signal to instruct the execution of segment ring assembly
Judge whether or not a start signal has been input.
If the request is cut off, the procedure proceeds to step 91. Subsequently, in step 91, the assembly segment
42 is a position where it does not contact the existing segments 41a to 41c.
(Hereinafter referred to as coarse position)
Calculates the target position / posture and calculates the target position / posture
To the servo controller 53
Output. The target position and posture of the erector
2 means the target position / posture of the segment gripper 34
I have. Here, the coarse position depends on the turning angle of the
And an element whose origin is the center position of the erector as shown in FIG.
It is represented by a cubic coordinate system (X, Y, Z). Here, the main body control unit 52 operates the assembly segment
The A-type segments A1 to A7 and the B-type
G1, B2, or K segment K
I know what it is. For example, in step 90, a start signal is input.
Determine what assembly segment 42 is when pressed
Initially set the segment judgment counter to 1
Then, this is stored in the memory. Then, a procedure 9 described later.
When the bolt temporary fastening control of 4 is completed, the segment
The counter is incremented and stored in the memory. This place
If the segment judgment counter is 1, the A-segment
Assembly A4, and the segment judgment counter is 2
When assembling the A-type segment A3,
Each time the judgment counter is incremented, the A-segment
A5, A2, A6, A1, A7, B type segment B
Assemble 1, B2, K-shaped segment K. Subsequently, in step 92, the image processing apparatus 5
1 includes an assembly segment 42 and existing segments 41a to 41a.
3c from the light emitters 44a to 44c at the boundary with 1c.
Light generated by the irradiation of the slit light.
Image processing of slit light images AA *, BB *, CC *
Then, the coordinates of the end point are extracted. Subsequently, in step 93, extraction is performed in step 92.
The end point coordinate value input and the memo input from the input device 55
Design position / posture data of the assembly segment stored in the
The assembly segment 42 using the existing segment 4
Positions where bolts can be fastened to
Electa target that is positioned at the bottom
Calculate the position and orientation, and respond
Output to the servo controller 53
I do. The design position / posture data of the assembly segment 42 is
Multiple design position / posture data stored in memory
Selected by the operator is used
But here, it corresponds to the assembly pattern data shown in FIG.
Design position / posture data to be used. Also here
Is displayed on the display device 56 by the operator.
The set displayed on the display device 56 based on the balance information
Segment type indicating the design position / posture of the vertical segment 42
Select and input while looking at the status (described above), but tail clearer
Rotation direction of each assembly segment 42 based on the
The rotation amount may be input. Subsequently, in step 94, the input device 55
Bolting force data input and stored in memory
According to the assembly segment 42 to the existing segment 41
Command value for bolt tightening to perform temporary bolt tightening
Is output to the servo controller 53. Here, the assembly segment
For the bolt fastening force data of
12 corresponding to the input assembly pattern data.
Data is used. Subsequently, in step 95, the data stored in the memory is stored.
K segment from the segment judgment counter
It is determined whether or not the bolt has been temporarily tightened for K,
Procedure when it is determined that the bolts are not temporarily fastened
Return to 91. The rough positioning control procedure of step 91 in FIG.
Details will be described with reference to FIG. First step 100
The distance measured by the distance meter 60 and the angle detector 61, that is, the distance
Distance L1 from distance gauge 60 to inner peripheral surface of existing segment 41
From the rotational position of the
Calculate the tail clearance T of the machine and note this
And the existing segment 41 and the erecta
The deviation of the distance from the main body 12 is obtained, and this is used for positioning control.
Is stored in a memory as a correction value. Subsequently, in step 101, the data is stored in the memory.
Design position and posture of the assembled segment 42
From the position / posture information of the set segment 41c,
Slit 42 on the existing segment 41 and the existing segments 41a to 41c.
The light images AA *, BB *, and CC * are the television camera 4
5a, 45b, 45c into the camera field of view, and
Segment 42 and existing segments 41a to 41c come into contact with each other.
For example, the assembly segment 42 that does not perform
Away from the contacts 41a to 41c, for example, 10 mm to 20 mm
Is calculated, and the assembly segment 42 is
Calculates the target position and posture of the erector to be located at the coarse position
I do. Subsequently, in step 102, the previously obtained
The rotation motor 16 and the pressing
Key 22, horizontal slide jack 25, front and rear slide jack
Key 28, including attitude control jacks 31, 32, 33
Calculate the command value of the axis actuator. Then step 1
03: Servo control of the actuator command value
Output to the device 53, and the servo controller 53
Wait for the eta to finish controlling. Next, the measurement is controlled in a procedure 92 of FIG.
Details of the image processing of the image processing device 51 will be described with reference to FIG.
I do. In the coarse positioning control explained earlier,
Assume that the element 42 is positioned at the position shown in FIG.
You. At this time, the assembly segment 42 and the existing segment 4
1a and 41b at the boundary along the circumferential direction of the tunnel
Between the assembly segment 42 and the existing segment 41c.
One light source at each of the boundaries along the axis of the channel
The slit light of 44a to 44c is irradiated, and this slit light
Irradiation of the assembly segment 42 and the existing segment 4
Slit light images AA *, BB generated on 1a to 41c
*, CC * are surely the TV cameras 45a, 45b,
The camera enters a camera field of view 46a, 46b, 46c of 45c. I
Accordingly, the image processing device 51 includes the television camera 45a,
Camera images 47a, 47b, 4 reflected on 45b, 45c
7c, the above three slit light images AA *, BB
*, C-C * endpoint coordinates on the image coordinate system (xv, yv)
Marks a (ax, ay), a * (ax *, ay *), b (b
x, by), b * (bx *, by *), c (cx, c
y) and c * (cx *, cy *) are extracted. Next, fine positioning control in step 93 in FIG.
Details of the procedure will be described with reference to FIG. First, to step 201
Here, the end point loci extracted by the image processing device 51 are described.
Using the standard values a (ax, ay) to c * (cx *, cy *)
The assembly segment 42 and the existing segments 41a to 41
The amount of deviation from c is calculated. The operation is as follows
Do. That is, first, the end point coordinate value a (ax,
ay) to c * (cx *, cy *)
42 and relative positions of the existing segments 41a to 41c
As the assembly segment 42 and the existing segments 41a-4
1c, Δxa, Δxb, Δyc and step Δz
a, Δzb, Δzc (see FIG. 17) are calculated by the following equations.
It is. Δxa = (ax * −ax) · kx = Δx1 · kx Δxb = (bx * −bx) · kx = Δx2 · kx Δyc = (cy * −cy) · ky = Δy3 · ky Δza = (ay * −ay) · kz = Δy1 · kz Δzb = (by * −by) · kz = Δy2 · kz Δzc = (cx * −cx) · kz = Δx3 · kz where kx, ky and kz are image data in mm. Number of units
This is a coefficient for converting to a value. The above gaps Δxa to Δxc and step Δza
To the existing segments 41a to 41c based on
The position / posture deviation of the assembly segment 42 to be calculated is calculated.
A simple example of the position / posture deviation calculation is shown in the following equation. Edx = (Δxa + Δxb) / 2 edy = Δyc edz = (Δza + Δzc) / 2 eδx = (Δzb−Δza) / (Lya + Lyb) eδy = {(Δza + Δzb) / 2−Δzc} / (Lx
a + Lxc) eδz = (Δxb−Δxa) / (Lya + Lyb) where edx, edy and edz are shown in FIG.
Represents the positional deviation in the x-, y-, and z-axis directions, and e
δx, eδy, eδz are around the x-axis, around the y-axis, respectively.
This represents the attitude deviation around the z-axis. Also, Lxa, Lx
c, Lyz, Lyb are the grip centers of the assembly segment 42
o, slit light images A, B, and C on the assembly segment 42
Distance in x-axis direction and y-axis direction to each end point a, b, c
Is represented. Subsequently, in step 202, the position / form
Power deviations edx, edy, edz, eδx, eδy, eδ
From z, the correction amount dx of the position / posture of the assembly segment 42,
dy, dz, δx, δy, δz are obtained by the following equations.
You. Dx = −edx dy = −edy dz = −edz δx = −eδx δy = −eδy δz = −eδz Subsequently, in step 203, the existing segments 41a-4
1c.
Find the reference position / posture of the assembly segment 42 for combing
You. This calculation is performed as follows. Here, the assembly segment 4 after the coarse positioning is performed.
The position / posture 2 is assumed to be the position in the x-axis direction: P11 The position in the y-axis direction: P12 The position in the z-axis direction: P13 The posture around the x-axis: P14 The posture around the y-axis: P15 The reference position and posture of the assembly segment 42 are as follows: position in the x-axis direction: P21 = P11 + dx position in the y-axis direction: P22 = P12 + dy position in the z-axis direction: P23 = P13 + dz posture around the x-axis: P24 = P14 + δx around the y-axis Posture: P25 = P15 + δy Posture around the z-axis: P26 = P16 + δz. Subsequently, in step 204, the segment size is determined.
The current assembly segment 42 is determined to be an A-segment
A2 to A6 or A-type segments A1, A
7, B-type segments B1, B2, K-type segment K
To determine whether the segment is A-type segment A2 to A6
If so, the process proceeds to step 212, where the A-type segment A1,
A7, B type segment B1, B2, K type segment K
If it is determined that there is, the procedure proceeds to step 205. In step 212, the assembly segment 4
For positioning the position 2 at the reference position / posture P21 to P26
Calculate target position / posture. In step 205, the operator inputs
The assembly path of the assembly segment 42 selected and input from the device 55
Design position / posture of assembly segment 42 corresponding to turn
The data is read from the memory, and the reference position / posture P21 to
The deviation between P26 and the design position / posture is determined. Where the group
The design position and posture of the vertical segment are as follows: x-axis position: P1 y-axis position: P2 z-axis position: P3 x-axis posture: P4 y-axis posture: P5 z-axis posture: P6. At this time, the reference positions / postures P21 to P26
And the design positions / postures P1 to P6 are: Positional deviation in the x-axis direction: Δx = P21−P1 Positional deviation in the y-axis direction: Δy = P22−P2 Positional deviation in the z-axis direction: Δz = P23−P3x Attitude deviation around axis: Δδx = P24−P4 Attitude deviation around y axis: Δδy = P25−P5 Attitude deviation around z axis: Δδz = P26−P6 Subsequently, in step 206, the reference position / shape
Deviation between forces P21 to P26 and design positions / postures P1 to P6
Is set within the threshold value.
Assembling segment 42 can be assembled in total position / posture P1 to P6
Judgment whether the deviation is within the threshold
Proceed to step 207 to move the assembly segment 42 to the design position / shape.
Elector target position / posture to be located at
If the deviation is not within the threshold, proceed to step 208.
No. Here, the deviations Δx, Δy, Δz, Δδ
The threshold values to be compared with x, Δδy, and Δδz are respectively k
1, k2, k3, k4, k5, and k6. This threshold
The values are assembling segment 42 and existing segments 41a-4
Bolts used to fasten 1c and segments
It is set within the range of the gap with the provided bolt hole. example
If the gap between the bolt and the bolt hole is 2mm, the x-axis direction
The threshold values in the direction, y-axis direction and z-axis direction are 2 mm at the maximum.
However, it is set lower than the gap. At this time, -k1≤Δx≤k1 (1) -k2≤Δy≤k2 (2) -k3≤Δz≤k3 (3) -k4≤Δδx≤k4 (4) -k5≤Δδy≤k5 ... (5) -k6 ≦ Δδz ≦ k6 (6) is examined, and if satisfied, the process proceeds to step 207, where
If not, proceed to step 208. In step 208, the assembly segment 4
2 between existing segments 41a-41c
The reference positions / postures P21 to P26 so that
The position / posture P1 to P6 side only for the values k1 to k6
These are referred to as new reference positions / postures P21 to P26.
Then, the assembly segment 42 is moved to the new reference position / posture P.
Elector target position / posture to be positioned at 21 to P26
Calculate. In step 209, in step 206
Reference position / posture P21 to P26 and design position / posture P1
The comparison between the deviation from P6 and the threshold value is performed in the x-axis direction and in the y-direction.
Axial direction, position deviation in z-axis direction, around x-axis, around y-axis,
Judge whether all attitude deviations about z axis are completed
Then, when it is determined that all have been completed, proceed to step 210,
When it is determined that all of them have not been completed, return to step 206
You. Next, in step 210, the current assembly
Procedure when the segment 42 is an A-type segment A2 to A6
Turning according to the target position / posture of the erector obtained in 212
Motor 16, pressing jack 22, horizontal slide jack 2
5. Front and rear slide jack 28, attitude control jack 3
Command values for 7-axis actuators including 1, 32 and 33
The operation is performed, and the current assembly segment 42 becomes the A-type segment A
1, A7, B type segment B1, B2, K type segment
If K, erector calculated in step 207 or 208
According to the target position / posture, the 7-axis actuator
Calculate the command value. Subsequently, in step 211, the 7-axis
The actuator command value is output to the servo controller 53.
Thus, the fine positioning control ends. Next, in step 94 of FIG.
Details of the control procedure will be described with reference to FIG. First, step 301
At a position corresponding to the finely positioned assembly segment 42.
To extend the shield jack 10
42 to the existing segment of the existing segment ring 41L
Shield jack extension finger for pressing and fixing against
Output to the sequencer 8. At this time,
When the shield 8 receives the shield jack extension instruction signal,
Shield jack command signal to shield jack controller 9
And the shield jack control device 9
Extend the shield jack 10 in response to the jacking command signal.
Lengthen. The sequencer 8 is connected to the shield jack 10
Input detection signal of built-in stroke meter 10a
And press the shield jack 10 from the detection signal.
Judge whether or not the pressing is completed, and the pressing is completed
If it is determined that the
Outputs a decompression completion signal. Subsequently, in step 302, the sequencer 8
Whether the shield jack extension completion signal has been input from the
Judge that the shield jack extension completion signal is input.
When it is determined, the process proceeds to step 303. In step 303, the segment determination
From the counter, what the current assembly segment 42 is
Judgment and bolt tightening corresponding to the current assembly segment 42
The binding data is read from the memory, and the bolt fastening device 70 is read.
Are assembled according to the bolt fastening force data.
To temporarily fasten the bolts to the existing segment 41
Outputs the bolt fastening device command value to the servo control device 53
You. At this time, the memory is bolted as shown in FIG.
The result is memorized. That is, the A-type segment A2
A6 to A6 in the same manner as the conventional temporary fastening.
Extend the jack 10 and position the assembled segment.
Press against existing segment of existing segment ring 41L
When the shield jack 10 is pulled from the
Is not displaced in the direction of gravity by its own weight.
A degree of fastening force is stored, and the A-type segment A1,
A7, B type segment B1, B2, K type segment K
On the other hand, the shield jack 10
The assembly segment changes in the direction of gravity due to its own weight when
A fastening force of a magnitude that can be adjusted is stored. The operation of the present embodiment configured as described above will now be described.
explain. As an example, according to the assembly pattern data,
The case of assembling the segment ring will be described. Ma
First, the operator displays the seal displayed on the display device 56.
Seeing the tail clearance information of the excavator, input device 5
5 to select and enter the assembly pattern data.
Instructs the assembly of the cement ring. Then, the main body control device 52 starts the assembly
Segment 42 with respect to the existing segments 41a to 41c.
Calculate command values of 7-axis actuator such as coarse positioning
Output to the servo controller 53. Servo control device 5
3 controls the 7-axis actuator according to the command value
The assembly segment 42 is roughly positioned. Next, the main body control device 52 operates as an image processing device.
51, the end point coordinate values a (ax, ay) to c extracted by
By using * (cx *, cy *), the existing segments 41a-41
Deviation edx to eδ of assembly segment 42 with respect to 41c
z, and based on the deviations edx to eδz, the existing segment
Position of the assembly segment 42 with respect to the elements 41a to 41c
Reference position / posture P21 to P for eliminating placement / posture deviation
Find 26. At this time, the current assembly segment 42
In the case of A-type segments A2 to A6,
D in the reference position / posture P21 to P26.
Of the 7-axis actuator according to the target position / posture
Finds the command value and outputs this command value to the servo controller 53
I do. On the other hand, the current assembly segment 42 is
A1, A7, B type segment B1, B2, K type
In the case of segment K, the operator selects and inputs
Design position / posture P1 corresponding to the assembled assembly pattern data
Read P6 and design with reference position / posture P21 to P26
The deviations Δx to Δδz from the positions / postures P1 to P6 are obtained, and
When the deviations Δx to Δδz of the values are within the threshold values k1 to k6
Moves the assembly segment 42 to the design position / posture P1 to P6.
7-axis actuator according to the target position / posture
Obtain the command value of the tutor, and use this command value in the servo control unit.
Output to the device 53. On the other hand, the deviation Δx to Δδz is the threshold
If not within k1 to k6, the reference position / posture P21
P26 is shifted to the design position / posture P1 to P6 side by the threshold value k1
New reference position obtained by shifting by k6
The postures P21 to P26 are obtained, and the assembly segment 42 is
Elements located at new reference positions / postures P21 to P26
7-axis actuator finger according to the target position and posture of the actuator
And outputs the command value to the servo controller 53.
You. The servo control device 53 operates according to the command value.
The assembly segment 42 is controlled by controlling the seven-axis actuator.
Fine positioning. Next, the main body controller 52 controls the sequencer 8
To output a shield jack extension instruction signal. Do so
And the sequencer 8 feeds the shield jack controller 9
Outputs the jack command signal and controls the shield jack
The device 9 seals according to the shield jack command signal.
Extend the jack 10. And the assembly segment 4
2 has been pressed against the existing segment ring 41L.
Then, the sequencer 8 sends the shield
Outputs the key extension completion signal. Then, the main unit control
The bolt 52 is used to move the bolting device 70.
The device command value is output, and the assembly segment 42 and the existing segment are output.
A bolt is inserted into the ment ring 41L and temporarily fastened. As described above, all the assembly segments 42
Performs positioning and temporary tightening of bolts to form a K-shaped segment.
The bolts are temporarily tightened and the segment rings are assembled.
When it is looked up, shield jack by sequencer 8
After extending the shield excavator by extending 10, the seal
Release the jack 10. At this time,
The segment ring is displaced by its own weight and becomes almost circular.
You. After that, all the temporary provisional fastening by the operator
Of the ring of the segment ring
Complete the setup. According to the above-described embodiment, the following effects can be obtained.
Fruit is obtained. That is, the individual assembly segments 42
When assembled, assembled at the top inside the tunnel
The plurality of assembly segments 42 are connected to the existing segment ring 4.
Displace radially outward with respect to 1L existing segment 41
Position, so the insertion space for the last K-shaped segment K
The gap is larger than the actual size of the K-shaped segment K,
Segment K can be easily inserted, and K-shaped segment K
It is prevented from contacting the B-shaped segments B1 and B2,
Segment damage, seal material breakage, segment assembly
A decrease in standing accuracy is prevented. Also, as described above, the assembly segment 42
When temporarily fastening bolts after positioning, the assembly segment
The bolt fastening force of the bolt 42 is the same as the conventional bolt temporary fastening.
When the shield jack 10 is opened,
To the extent that the cement 42 hardly displaces in the direction of gravity.
Then, the assembly of the segment ring is completed and the system
Even if you open the field jack 10, it will remain at the top of the tunnel
The assembled segment is almost completely removed from its assembly position.
Does not move. As a result, assembled at the top inside the tunnel
A plurality of assembly segments 42 to the existing segment ring.
41L is shifted radially outward with respect to the existing segment 41 of 41L.
To which the present embodiment involves
According to the law, when sequentially assembling segment rings,
Multiple assembly segments located above the segment ring
Gradually spreads outward in the radial direction,
The shape gradually elongates and the top of the shield machine
Le clearance T gradually decreases, and finally Segume
Tring is tail skin plate 1 of shield body 1
a. In the present embodiment, in the tunnel
Of the plurality of assembly segments 42 assembled on the
Release the shielding jack 10 with the bolting force on the locking side
Large enough to be displaced in the direction of gravity by its own weight when
The temporary fastening of the bolts of the K-shaped segment K has been completed.
To release the shield jack 10
The multiple segments assembled at the top of the panel have their own weight
Segment ring displaced in the direction of gravity with
Is a shape determined by the segment shape. Therefore,
Gment ring has the appropriate ring shape and shield
The small tail clearance T at the top of the move
No, the segment ring is tail ski of the shield body 1.
Interference with the template 1a is prevented. In the present embodiment, the assembly segment
The selection of the assembly pattern data depends on the system measured by the operator.
Judgment based on tail clearance information
However, the present invention is not limited to this.
Clearance information and existing segment ring 41L
Automatically determine and select based on assembly information
You may. Also, when fine positioning the assembly segment 42
, Light projectors 44a-44c and television cameras 45a-4
Assembly segment 42 using a visual sensor consisting of 5c
Detecting the relative position with the existing segments 41a to 41c
However, the present invention is not limited to this.
Other sensors such as the distance sensor may be used. According to the present invention, finally assembled
The insertion gap of the segment with both ends tapered increases
Makes it easier to insert the segment,
Damage or breakage of sealing material, low assembly accuracy of segments
Bottom can be prevented. Also, both ends are tapered at the end of assembly
Segment can be easily inserted and the segment
The ring shape to the proper ring shape
And the tail clearance at the top of the shield machine is small
The ring does not become a segment ring on the shield body
Interference is prevented.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front sectional view of an erector main body of a segment assembling apparatus used in an embodiment of the present invention. FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a sectional view taken along line III-III of FIG. 1; FIG. 4 is a sectional view taken along line IV-IV of FIG. 1; FIG. 5 is a detailed sectional view of the segment gripper shown in FIG. 1; FIG. 6 is a view showing a bolt fastening device mounted on the erector body shown in FIG. 1; FIG. 7 is a diagram showing a positional relationship between an assembling segment and an existing segment of a projector and a television camera used for positioning a segment according to the embodiment of the present invention, and a system configuration. FIG. 8 is a block diagram showing details of a system configuration shown in FIG. 7; FIG. 9 is a diagram showing an example of a segment arrangement in the embodiment of the present invention. FIG. 10 is a diagram showing a design position and posture of an assembly segment for making a segment ring a perfect circle in the embodiment of the present invention. 11 is a diagram showing details of the design position and posture of the assembly segment shown in FIG. FIG. 12 is a table showing bolt fastening force when assembling the segments according to the design positions and postures of the assembly segments shown in FIG. 10; FIG. 13 is a view showing a design position and a posture of an assembly segment for forming the segment ring into a vertically long oval shape in the embodiment of the present invention. 14 is a table showing bolt fastening force when assembling the segments according to the design positions and postures of the assembly segments shown in FIG. 15 is a flowchart showing an assembly control procedure of an assembly segment in the main body control device shown in FIG. 7; 16 is a flowchart showing a coarse positioning control procedure shown in FIG. FIG. 17 is an explanatory diagram of the measurement control procedure shown in FIG. 18 is a flowchart showing a fine positioning control procedure shown in FIG. FIG. 19 is a diagram used for position / posture deviation calculation in the fine positioning control procedure shown in FIG. 18; FIG. 20 is a flowchart showing a bolt temporary fastening control procedure shown in FIG. DESCRIPTION OF SYMBOLS 10 Shield jack 11 Shield body 12 Electa body 41, 41a, 41b, 41c Existing segment 41L Existing segment ring 42 Assembly segments 44a, 44b, 44c Projectors 45a, 45b, 45c TV camera 48 Camera switch 49 Image input Device 50 Image memory 51 Image processing device 52 Main control device 53 Servo control device 54 Hydraulic control device 55 Input device 56 Display device 70 Bolt fastening device

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Hisagi Hashimoto 650, Kandate-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. (72) Inventor Hiroki Polymorph 650, Kandate-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Inside the Tsuchiura Plant Co., Ltd. (72) Ken Kamei, Inventor Kenchicho, Tsuchiura City, Ibaraki Prefecture 650, Tsuchiura Plant Hitachi Construction Machinery Co., Ltd. (56) References JP-A-5-106396 (JP, A) JP-A-8-4494 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) E21D 11/40

Claims (1)

(57) [Claim 1] When a tunnel is constructed by excavating the ground with a shield machine having a plurality of shield jacks, an assembly segment is positioned with respect to an existing segment, and then the shield is positioned. By extending the jack and pressing the assembly segment against the existing segment, in this state, inserting bolts into the assembly segment and the existing segment and temporarily fastening them, assembling a plurality of assembly segments from below to above. In the segment assembling method of assembling a snow segment ring and finally finally fastening the bolts to complete the assembly of the segment ring, when assembling the plurality of assembly segments from below to above, the assembly segment is first inserted into the assembly segment. The first step of assembling according to the existing segment After the one step, a second step of assembling the assembly segment by shifting the assembly segment radially outward with respect to the segment of the existing segment ring, and finally inserting a segment having both ends tapered, and assembling; A method of assembling a segment, wherein, when assembling the segment, the fastening force of the temporary fastening of the bolt is set to a size such that the segment can be displaced in the direction of gravity by its own weight when the shield jack is opened.