JP3343568B2 - Tunnel excavator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel excavator having a cutter head provided at the front of an excavator main body so as to be swingable around a tunnel axis, and a swing mechanism for swinging the cutter head. Things.

[0002]

2. Description of the Related Art In general, a tunnel excavator excavates a ground while rotating a cutter head provided at a front portion of an excavator body. In this case, the cutter head is rotated by transmitting the rotational force of the hydraulic motor or the electric motor to a gear or a sprocket or a rotational torque transmitting mechanism having a function equivalent thereto.

However, in this rotary cutter head, one of these hydraulic motors or electric motors is used.
In the case of a tunnel excavator that requires a large rotation torque because the output torque per unit is small, it is necessary to install a large number of motors to obtain the required drilling rotation torque, or a gear connected to the cutter head. It was necessary to secure a large reduction ratio by increasing the size. For this reason, the drive unit of the cutter head becomes large as a whole, and it is difficult to install the drive unit in the excavator main body, and there is a problem that the manufacturing cost increases.

[0004] As means for solving such problems,
JP-A-10-140979 and Japanese Patent No. 2872
Japanese Patent Application Publication No. 656 proposes a tunnel excavator in which a cutter head provided at a front portion is swingably driven by a jack.

As shown in FIG. 9A, a tunnel excavator 50 proposed in the above-mentioned Japanese Patent Application Laid-Open No. H10-140979 swings a cutter head provided at a front portion to form a rectangular or other irregular cross section. The cutter head swing mechanism includes four brackets 52a, 52b, 52c, 5c fixed to the main shaft 51 of the cutter head.
2d, the brackets 53a, 53b, 53c, 53d fixed to the inner wall surface of the excavator body 57, and the swinging jacks 54a, 54b, 54c mounted between the brackets 52a to 52d; 54d.

The tunnel excavator 5 having such a configuration
0, a pair of the swinging jacks 54a to 54d of the swinging jacks 54a to 54d at diagonal positions to each other.
The cutter head is rotated by a predetermined angle by operating the other pair of swinging jacks 54b and 54d in the contracting direction at the same time as operating the a and 54c in the extending direction (FIG. 9).
(B)) After this rotation, the pair of swing jacks 54
By operating the other pair of swinging jacks 54b and 54d in the extending direction at the same time as operating the a and 54c in the contracting direction, the cutter head is rotated by a predetermined angle in the opposite direction (FIG. 9C). By repeating each operation alternately, the cutter head is caused to perform a swinging motion within a predetermined angle range.

Further, as shown in FIG. 10, a tunnel excavator 61 disclosed in the aforementioned Japanese Patent No. 2872656 excavates a cutter head provided at a front portion by swinging the cutter head around a tunnel axis. There is a hydraulic cylinder 62 whose reciprocating mechanism can linearly reciprocate, a rack 63 reciprocated by the hydraulic cylinder 62, and a reciprocating motion of the rack 63 converted into a reciprocating motion of the cutter head for transmission. And a sprocket 65 attached to the main shaft 64 of the cutter head.

[0008]

However, in the tunnel excavator 50 proposed in Japanese Patent Application Laid-Open No. H10-140979, each of the cutter heads swings at the swing stroke end (FIGS. 9B and 9C). Swing jacks 54a to 54d
Is the position where the output torque cannot be generated most.
Each of the rocking jacks 54a to 54d generates the largest output torque near the center of its stroke.
When this rocking mechanism is applied to a cutter head having a circular cross section, for example, the arrangement of the rocking jack causes the output torque to decrease more remarkably at the rocking stroke end of the cutter head, resulting in insufficient torque and unstable excavation. There is a problem that becomes.
On the other hand, there is a problem that an unnecessarily high output rocking jack is required to obtain a sufficient excavation torque.

In the swinging mechanism of the tunnel excavator 61 disclosed in Japanese Patent No. 2872656,
Since the angular speed of the cutter head with respect to the expansion and contraction speed of the hydraulic cylinder 62 can be kept constant, there is no torque fluctuation due to the rotational position, and stable excavation can be performed. However, the structure is complicated and the swing transmitted to the cutter head is complicated. Since the reaction force of the power acts in a direction in which the hydraulic cylinder 62 is bent, there is a problem that the rigidity of the hydraulic cylinder 62 must be increased. Therefore, the swing mechanism becomes large as a whole.

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem. In a tunnel excavator of the type having an oscillating cutter head, a small and simple oscillating mechanism is sufficient. It is an object of the present invention to obtain an excavating force and to always perform stable excavation irrespective of an excavation cross-sectional shape.

[0011]

To achieve the above-mentioned object, a tunnel excavator according to the present invention comprises a cutter provided at the front of an excavator body so as to be swingable around a tunnel axis. In a tunnel excavator provided with a head and a rocking mechanism for rocking the cutter head, the rocking mechanism includes an arm projecting radially from a drive shaft of the cutter head, and one end pivotally connected to the arm. A cutter swinging jack that is attached and the other end is pivotally attached to the excavator body, and one end is pivotally attached to the arm and the other end is attached to the arm.
Equipped with an assist jack that is pivotally attached to the excavator body,
Assist jack and is characterized that you the torque applied to the cutter head as it approaches the swing stroke end of the cutter head to be swung by the extension and contraction of the cutter oscillating jack is arranged to be larger .

In the present invention, a cutter swing jack, one end of which is pivotally attached to the arm and the other end of which is pivotally attached to the excavator body, is extended and contracted to transmit a swinging power to the arm to swing the cutter head. is dynamic, according to the swing angle of the cutterhead increases, when one end is pivotally connected to the arm DOO
First, the assist jack whose other end is pivotally connected to the excavator body is extended. Thus , the cutter head is
Is rocked by the cutter rocking jack.
While the torque applied to the cutter head is reduced, the torque applied to the cutter head by the assist jack is increased, so that the reduction of the cutter head torque is suppressed.

According to the present invention, there is provided a cutter swinging jack .
Assist jack is provided to compensate for the decrease in torque applied to the cutter head , and the installation space for the swing mechanism can be made compact. A sufficient excavation force can be obtained by suppressing a decrease in torque, and stable excavation can always be performed.

In the present invention, it is preferable that the assist jack is disposed so as to become a dead center near a center of a stroke of the cutter swinging jack. The Rukoto to arranging the assist jack, it is possible to generate a large torque toward the swinging stroke end of the cutter head, an effect capable of performing more stable drilling. Also, with one assist jack,
Since the operation of the two swinging jacks can be assisted, the structure becomes simpler and the control thereof becomes easy.

[0015]

Next, a specific embodiment of a tunnel excavator according to the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a front view of a tunnel excavator 1 according to a first embodiment of the present invention, FIG. 2 is a longitudinal sectional view of the tunnel excavator 1, and FIG. The figures are respectively shown in FIG.

In the tunnel excavator 1 of the present embodiment,
A cylindrical skin plate 2 is provided, and a cutter head 3 is arranged in front of the skin plate 2 so as to be swingable by a cutter head swinging mechanism 4 described later. A sediment discharging device for forming a chamber 6 between the bulkhead 5 and the rear end of the cutter head 3 at the rear end thereof, and discharging the sediment in the chamber 6 rearward from inside the chamber 6 to the rear. (Not shown) is extended. In addition,
The skin plate 2 and the bulkhead 5 constitute an excavator body according to the present invention.

Excavation is performed by extending a propulsion device (not shown) while oscillating the cutter head 3 by the cutter head oscillating mechanism 4. By this excavation, the earth and sand in front of the cutter head 3 is taken into the chamber 6,
The excavated earth and sand stored in the chamber 6 is carried backward by the earth and sand discharging device.

Next, the detailed structure of the cutter head 3 and the cutter head swinging mechanism 4 will be described.

The cutter head 3 of this embodiment is a spoke type cutter head, and has four spokes 7, 8, 9, 1
0 is arranged such that the angle between adjacent spokes is 90 °. Each of the spokes 7 to 10 has a built-in overcutter device 11, and an overcutter 12 provided at the tip of the overcutter 11 protrudes outward from the tips of the spokes 7 to 10 to set a large excavation diameter. Have been able to.

A main shaft (corresponding to a drive shaft in the present invention) 13 of the cutter head 3 is of a center shaft type, and a front part is rotatable around an axis by a bush 14 and a rear part by a bearing 15. It is supported by.

Two arms 16 and 17 projecting in the radial direction of the cutter head 3 are fixed to the outer peripheral surface of the central portion of the main shaft 13 (behind the bulkhead 5).

One end of one cutter swinging jack (hereinafter referred to as a swinging jack) 18, 19 is rotatably connected to each of the arms 16, 17, respectively. The other end of 19 is rotatably connected to the upper rear surface of the bulkhead 5.

One end of one assist jack 20, 21 is rotatably connected to each of the arms 16, 17, respectively.
The other end of 21 is rotatably connected to the lower rear side of the bulkhead 5. The cutter head swing mechanism 4 according to the present embodiment includes the arms 16 and 17 and the swing jack 1.
8 and 19 and assist jacks 20 and 21.

When the swing jacks 18 and 19 are expanded and contracted to the center of the stroke, the assist jacks 20 and 21 are in the most contracted state, and each of the assist jacks 20 and 21 is located at both ends. They are arranged such that a straight line connecting the connection point and the center point of the main shaft 13 is on a straight line, that is, a dead point. Also,
These assist jacks 20 and 21, the generated torque with the actuating the extending direction, the cutter in other words head
3 are arranged so that the torque applied to them increases.

When the swing jacks 18 and 19 are expanded and contracted to the center of the stroke, the one arm 1
The arrangement state of the oscillating jack 18 and the assist jack 20 connected to the arm 6 and the arranging state of the oscillating jack 19 and the assist jack 21 connected to the other arm 17 are indicated by a straight line B passing through the center point of the main shaft 13 (see FIG. 4).

Next, the operation of the cutter head swinging mechanism 4 will be described with reference to FIG.

The state in which the rocking jacks 18 and 19 are expanded and contracted to the center of the stroke is referred to as a rocking reference state (shown by a solid line in the figure), and the rocking jack 18 is operated in the extension direction from the rocking reference state. At the same time, by operating the other swinging jack 19 in the contracting direction, the cutter head 3 is rotated leftward by a predetermined angle (approximately + 15 ° in this embodiment), and when the cutter head 3 reaches the assist start position. By operating the assist jack 20 in the extension direction to assist the swing jack 18 operating in the extension direction, the cutter head 3 is rotated to the swing stroke end (+ 47.5 ° in this embodiment). After this rotation, the cutter head 3 is moved to the right by operating the swinging jack 18 in the contracting direction and simultaneously operating the other swinging jack 19 in the extending direction and further operating the assist jack 20 in the contracting direction. The operation of the assist jack 20 is stopped when the assist jack 20 reaches the assist start position.

Subsequently, when the swing jack 18 is contracted and the swing jack 19 is extended, the swing jack 18 is rotated through a swing reference state by a predetermined angle (about -15 ° in this embodiment) to reach the assist start position. Then, the assist jack 21 is operated in the extending direction so as to assist the swing jack 19 operating in the extending direction, and the cutter head 3 is rotated to the swing stroke end (-47.5 degrees in this embodiment). After this rotation,
By operating the swinging jack 18 in the extending direction and simultaneously operating the other swinging jack 19 in the contracting direction, and further operating the assist jack 21 in the contracting direction,
The operation of the assist jack 21 is stopped when the cutter head 3 is rotated rightward to reach the assist start position. In this manner, the swinging jacks 18 and 19 pass through the swinging reference position, and by repeating these series of operations, the cutter head 3 swings within a predetermined angular range (95 ° in this embodiment). Is performed. FIG. 4 shows the arrangement of the swing jacks 18 and 19 and the assist jacks 20 and 21 when the cutter head 3 is rotated to the swing stroke ends on the left and right sides, respectively, by two-dot chain lines. .

FIG. 5 shows a hydraulic circuit for operating the swing jacks 18, 19 and the assist jacks 20, 21.

The hydraulic pipes 22 and 22 'on the head side and the hydraulic pipes 23 and 2 on the bottom side of the rocking jacks 18 and 19, respectively.
3 'is connected to solenoid valves 25, 25' via pilot check valves 24, 24 '.
5, 25 'are connected to a pump 27 via a P line 26 and to a tank 29 via an R line 28.

The solenoid valves 25 and 25 'have a P line 2
6 connects the bottom hydraulic lines 23 and 23 'and the R line 28 and the hydraulic lines 22 and 22' to extend the rocking jacks 18 and 19; B port for connecting the hydraulic lines 22 and 22 ′ and connecting the R line 28 and the hydraulic lines 23 and 23 ′ for contracting the oscillating jacks 18 and 19, and the oscillating jacks 18 and 19. An H port for stopping the expansion / contraction operation is provided.

Each of the assist jacks 20, 21
Are connected to solenoid valves 33, 33 ', and each of the solenoid valves 33, 33' is connected via a P line 26a having a throttle valve 34. It is connected to the pump 27 and to the tank 29 via the R line 28. The throttle valve 34 is connected to the assist jack 2.
It is provided to prevent the pressure of the entire circuit from decreasing when supplying pressure oil to 0 and 21.

The solenoid valves 33 and 33 'have a P line 2
A port for extending the assist jacks 20, 21 by connecting the R line 28 and the head-side hydraulic pipes 31, 31 'and connecting the R line 28 to the head-side hydraulic pipes 31, 31'; Hydraulic piping 31,
31 ', and the R line 28 and the bottom side hydraulic pipes 32, 32' are connected to contract the assist jacks 20, 21 and the b port, and the operation of the assist jacks 20, 21 is stopped to swing. A J port is provided that can be expanded and contracted by expansion and contraction of the jack 18.

The solenoid valves 25, 25 ', 33, 33' are controlled by signals from a controller 30. For this control, the swing angle of the cutter head 3 detected by a swing angle detecting device (not shown) of the cutter head 3 is input to the controller 30, and each of the solenoid valves 25, Switches 25 ', 33, and 33' are switched to arbitrary ports.

Next, the control procedure of the solenoid valves 25, 25 ', 33, 33' by the controller 30 will be described. First, when the cutter head 3 is rotated leftward from the swing reference position, the electromagnetic valve 25 is connected to the A port,
When the solenoid valve 25 'is simultaneously switched to the B port and the value detected by the swing angle detecting device (swing angle) reaches the assist start position (about + 15 °), the solenoid valve 33 is set to a
Switched to port. When the detected value reaches the swing stroke end (47.5 °), the solenoid valve 25 is switched to the B port, the solenoid valve 25 'is switched to the A port at the same time, and the solenoid valve 33 is switched to the b port. Can be switched.
When the detected value reaches the assist start position, the solenoid valve 33 is switched to the J port.

Subsequently, the detected value is changed to the swing reference position (0
°), and reaches the assist start position (about -15 °), the solenoid valve 33 'is switched to the port a. Thus, the detected value is at the end of the swing stroke (the swing angle is -47.5 °).
At the same time, the solenoid valve 25 is switched to the A port, the solenoid valve 25 'is switched to the B port, and the solenoid valve 33' is switched to the b port. Thus, when the detected value reaches the assist start position, the solenoid valve 33 'is switched to the J port. By repeating these series of controls, the cutter head 3 is controlled to swing.

FIG. 6 is a relationship diagram for explaining the relationship between the swing angle of the cutter head and the torque of the cutter head. FIG. 6 shows a case where the cutter head 3 is swung from the swing reference position to the end of the swing stroke, and then is rotated backward to swing to the swing reference position.

As shown, the swinging jacks 18, 19
When the cutter head is swung by operating only the cutter head, the cutter head torque is gradually decreased by the swing angle. However, the assist jack 2 is moved at the assist start position (about 15 °).
By operating 0 (21), the cutter head torque increases, and the cutter head torque obtained at the swing stroke end (47.5 °) is changed by the swing jacks 18 and 19 in the swing reference state (0 °). It can be made substantially the same as the obtained cutter head torque. In FIG. 6, the torque generated when the assist jack is operated in the extension direction is smaller than the torque generated when the assist jack is operated in the contraction direction. This is because the area for receiving the hydraulic pressure when operating in the contraction direction is smaller than when operating in the expansion direction.

According to this embodiment, the oscillating jacks 18, 1
Assist jack 2 reduces cutter head torque by 9
The operation is compensated by the operation of 0 (21), and there is an effect that torque fluctuation is suppressed and stable excavation can always be performed with sufficient excavation force. Further, according to the present embodiment, the cutter head swinging mechanism 4 has a very simple configuration, and the mounting space thereof can be made compact.

In this embodiment, four spokes 7 to
10 makes an angle of 90 ° between adjacent spokes
Therefore, it is possible to reliably excavate the facet by setting the swing angle to 95 ° (90 ° or more).

In this embodiment, two solenoid valves 25,
25 'through the head-side hydraulic pipes 22, 22' and the bottom-side hydraulic pipes 23, 2 of the rocking jacks 18, 19, respectively.
3 ′ are connected to each other, but the head-side hydraulic pipe 22 of the oscillating jack 18 and the bottom-side hydraulic pipe 2 of the oscillating jack 19 are connected.
3 'and the bottom hydraulic pipe 23 of the oscillating jack 18 and the head-side hydraulic pipe 22' of the oscillating jack 19 may be connected to one solenoid valve for control. It is possible.

In this embodiment, control is performed so that one of the two assist jacks 20, 21 which assists the operation of the swing jack extending only from the swing reference state is operated. However, the present invention is not limited to this, and the two assist jacks 20, 21 may be controlled to operate according to the expansion and contraction of the swinging jacks 18, 19. In this case, the assist jacks 20 and 2
It is necessary to control such that the generated torque does not become too large by operating the motor 1. Further, as described above, it is possible to control two solenoid valves for controlling the operations of the assist jacks 20 and 21 with one solenoid valve.

(Second Embodiment) In the second embodiment, there is basically no difference from the first embodiment except for the configuration of the swinging mechanism 4a of the cutter head 3. Therefore,
Parts common to the first embodiment will be described using the same reference numerals.

FIG. 7 is an explanatory diagram for explaining the operation of the cutter head swinging mechanism 4a according to the second embodiment.

In this embodiment, two arms 16 and 17 projecting in the radial direction of the cutter head 3 are fixed to the outer peripheral surface of the central portion of the main shaft 13 of the cutter head 3 (the rear side of the bulkhead 5). I have. These arms 16,
One end of each of the swinging jacks 18 and 19 is rotatably connected to each of the swinging jacks 17. The other end of each of the swinging jacks 18 and 19 is rotatably connected to the upper rear surface of the bulkhead 5. Have been.

One end of one assist jack 20, 21 is rotatably connected to each of the arms 16, 17, respectively.
The other end of 21 is rotatably connected to the rear side of the bulkhead 5.

The cutter head swinging mechanism 4a includes the arms 16, 17, swinging jacks 18, 19, and assist jacks 20, 21. The assist jacks 20, 21 are connected to the swinging reference. In a state (a state in which the swinging jacks 18 and 19 are expanded and contracted to the center of the stroke) (shown by a solid line in the drawing), a substantially contracted state is obtained.
In addition to being arranged to be operable in the extension direction, the generated torque increases as the assist jack 20 is extended during left rotation and the assist jack 21 is extended during right rotation, and the generated torque is maximized at the end of the swing stroke. Are located in When the swing jacks 18 and 19 are set to the swing reference state, the arrangement state of the swing jack 18 and the assist jack 20 connected to the one arm 16 and the swing jack connected to the other arm 17 are set. The arrangement of the jack 19 and the assist jack 21 is symmetric with respect to a straight line C passing through the center point of the main shaft 13.

Next, the operation of the cutter head swinging mechanism 4a will be described with reference to FIG.

The state in which the rocking jacks 18 and 19 are expanded and contracted to the center of the stroke is referred to as a rocking reference state (indicated by a solid line in the drawing), and the rocking jack 18 is moved in the extending direction from the rocking reference state. At the same time as the actuation, the other swinging jack 19 is actuated in the contracting direction, and the assisting jack 2 is further assisted to actuate the swinging jack 18.
By operating 0 in the extension direction, the cutter head 3 is rotated to the left in the swing stroke end (+ 47.5 ° in this embodiment).

After this rotation, the swing jack 19 is operated in the extension direction, and simultaneously, the swing jack 18 and the assist jack 20 are operated in the contraction direction to swing the cutter head 3 rightward. When the swing reference state is reached, the contracting operation of the assist jack 20 is stopped.

Subsequently, the extending operation of the swinging jack 19 and the contracting operation of the swinging jack 18 are performed, and the assist jack 21 is operated in the extending direction to assist the operation of the swinging jack 19. The cutter head 3 is swung rightward at the end of the stroke (-47.5 in the present embodiment).
°).

After this rotation, the swing jack 18 is operated in the extension direction, and at the same time, the swing jack 19 and the assist jack 21 are operated in the contraction direction to swing the cutter head 3 to the left. When the swing reference state is reached, the contracting operation of the assist jack 21 is stopped. By repeating the above-described operation in this manner, the cutter head 3 is provided with a predetermined angle range (95
°) FIG. 7 shows the swing jacks 18, 19 and the assist jack 2 when the cutter head 3 is rotated to the swing stroke ends on both the left and right sides.
The arrangement states of 0 and 21 are indicated by two-dot chain lines.

In this embodiment, the swinging jack 1
8, 19 and the assist jacks 20, 21 are operated as described above by the same hydraulic circuit as in the first embodiment. That is, the controller 30 controls the assist jack that assists the operation of the swing jack only on the side extending from the swing reference state.

According to the present embodiment, similar to the first embodiment,
Stable excavation can always be performed with sufficient excavating power by suppressing torque fluctuation, and the cutter head swing mechanism 4
Since “a” has a very simple configuration, the mounting space can be made compact. Further, the control of the swing jacks 18, 19 and the assist jacks 20, 21 can be facilitated.

(Third Embodiment) In the third embodiment, there is basically no difference from the first embodiment except for the configuration of the swinging mechanism 4b of the cutter head 3. Therefore,
Parts common to the first embodiment will be described using the same reference numerals.

FIG. 8 is an explanatory diagram for explaining the operation of the cutter head swinging mechanism 4b of the third embodiment.

In this embodiment, one arm 16 'projecting in the radial direction of the cutter head 3 is fixed to the outer peripheral surface of the central portion of the main shaft 13 of the cutter head 3 (the rear side of the bulkhead 5). . One ends of rocking jacks 18 and 19 are rotatably connected to the arms 16 ′, respectively, and the other ends of the rocking jacks 18 and 19 are rotatably mounted on the lower rear side of the bulkhead 5. Are linked. One end of one assist jack 20 'is rotatably connected to the arm 16'. The other end of the assist jack 20 'is rotatably connected to the upper rear surface of the bulkhead 5. Have been.

The cutter head swinging mechanism 4b includes the arm 16 ', swinging jacks 18, 19, and an assist jack 20'. The assist jack 20 'controls the swinging jacks 18, 19. When expanded and contracted to the center of the stroke (indicated by a solid line in the figure), a straight line connecting each connection point on both ends of the assist jack 20 ′ and the center point of the main shaft 13 is aligned, ie, It is arranged so as to be a dead center, and in this state, the assist jack 20 'is in the most contracted state.

Next, the operation of the cutter head swinging mechanism 4b will be described with reference to FIG.

The state in which the rocking jacks 18 and 19 are expanded and contracted to the center of the stroke is referred to as a rocking reference state (shown by a solid line in the drawing). From this rocking reference state, the rocking jack 18 is moved in the extension direction. The cutter head 3 is rotated rightward by a predetermined angle (about + 15 ° in the present embodiment) by operating the other swinging jack 19 in the contracting direction at the same time when the assisting jack 19 is operated. Activate the assist jack 20 'in the extension direction with the cutter head 3
Is rotated to the swing stroke end (+ 47.5 ° in this embodiment) (indicated by a two-dot chain line in the figure).

After the rotation, the swinging jack 18 is operated in the contracting direction, the other swinging jack 19 is operated in the extending direction, and the assist jack 20 'is further operated in the contracting direction. The head 3 is rotated to the left, and the operation of the assist jack 20 'is stopped when the head 3 reaches the assist start position.

Subsequently, when the swing jack 18 is contracted and the swing jack 19 is extended, the swing jack is rotated through a swing reference state by a predetermined angle (about -15 ° in this embodiment) to reach the assist start position. Then again the assist jack 2
The cutter head 3 is rotated to the swing stroke end (-47.5 degrees in the present embodiment) by operating 0 'in the extension direction (indicated by a two-dot chain line in the figure).

After this rotation, the swinging jack 18 is operated in the extending direction, the other swinging jack 19 is operated in the contracting direction, and the assist jack 20 'is further operated in the contracting direction. The head 3 is operated rightward, and when the head reaches the assist start position, the operation of the assist jack 20 'is stopped. By repeating the series of operations described above in this manner, the cutter head 3
Is made to perform a rocking motion within a predetermined angle range (95 ° in this embodiment).

According to this embodiment, the same effects as those of the first and second embodiments can be obtained, and the operation of two swing jacks can be assisted by one assist jack. This has the effect of simplifying the structure and facilitating its control.

In each of the above embodiments, an example in which the cutter head swinging mechanism 4, 4a, 4b is applied to a tunnel excavator for excavating a circular cross section has been described. However, the present invention is not limited to this. It is also possible to apply 4, 4a, 4b to a tunnel excavator for excavating a deformed section such as a rectangular section.

[Brief description of the drawings]

FIG. 1 is a front view of a tunnel excavator according to a first embodiment.

FIG. 2 is a longitudinal sectional view of the tunnel excavator according to the first embodiment.

FIG. 3 is a view taken in the direction of arrow A in FIG. 1;

FIG. 4 is an explanatory diagram for explaining the operation of the cutter head swinging mechanism of the first embodiment.

FIG. 5 is a hydraulic circuit diagram of the cutter head swing mechanism according to the first embodiment.

FIG. 6 is a relationship diagram for explaining a relationship between the swing angle of the cutter head and the torque of the cutter head.

FIG. 7 is an explanatory diagram illustrating the operation of the cutter head swinging mechanism according to the second embodiment.

FIG. 8 is an explanatory diagram illustrating an operation of a cutter head swinging mechanism according to a third embodiment.

FIG. 9 is an explanatory view of cutter head swing mechanisms (a), (b), and (c) in a conventional tunnel excavator.

FIG. 10 is an explanatory diagram of a cutter head swinging mechanism in a conventional tunnel excavator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tunnel excavator 2 Skin plate 3 Cutter head 4, 4a, 4b Cutter head swinging mechanism 5 Bulk head 6 Chamber 7, 8, 9, 10 Spoke 11 Over cutter device 12 Over cutter 13 Main shaft (drive shaft) 14 Bush 15 Bearing 16, 16 17 Arm 18, 19 Swing jack 20, 21, Assist jack 22, 31, Head side hydraulic pipe 23, 32 Bottom side hydraulic pipe 24 Pilot check valve 25, 25 'Solenoid valve 26 P line 27 Pump 28 R line 29 Tank 30 Controller 33 , 33 'Solenoid valve 34 Throttle valve

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takashi Minami 5 Yokaichi-cho, Komatsu-shi, Ishikawa Pref. Komatsu Plant, Ltd. Komatsu Plant (56) References JP-A-10-14079 (JP, A) JP-A-11- 256992 (JP, A) JP-A-2000-192784 (JP, A) Jikken 48-20918 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) E21D 9/08 E21D 9 / 06 301

Claims (2)

(57) [Claims] 1. A tunnel excavator comprising: a cutter head provided at a front portion of an excavator body so as to be swingable around a tunnel axis; and a swing mechanism for swinging the cutter head. An arm protruding radially from the drive shaft of the cutter head, a cutter swinging jack having one end pivotally attached to the arm and the other end pivotally attached to the excavator body, and one end attached to the arm. Pivoted and the other end
Equipped with an assist jack that is pivotally attached to the excavator body.
Tunneling assist jack, characterized that you torque applied to the cutter head is arranged so as to increase toward the swinging stroke end of the cutter head is swung by the expansion and contraction of the cutter oscillating jack Machine. 2. The tunnel excavator according to claim 1, wherein the assist jack is disposed so as to be located near a center of a stroke of the cutter swinging jack.