JP7469165B2 - Extension belt conveyor - Google Patents

Description

The present invention relates to an extension belt conveyor, and in particular to an extension belt conveyor for transporting excavation waste during tunnel excavation.

Conventionally, an extension belt conveyor is known for transporting excavation waste (rock blocks, soil, sand, etc. excavated from the ground) during tunnel excavation (see, for example, Patent Document 1).

The above-mentioned Patent Document 1 discloses a continuous belt conveyor device (extended belt conveyor) in which a crusher car, a tailpiece car, a storage cassette, and a main drive are arranged at intervals from the face side to the mine mouth side. Excavated waste is fed into the crusher car, crushed into small pieces, and then fed into the tailpiece car. The conveyor belt attached to the tailpiece car is advanced by the main drive, so that the excavated waste is transported along with the conveyor belt. When the face position advances, the tailpiece car is advanced. At this time, a new belt is paid out from the storage cassette and extended.

Although not explicitly stated in the above Patent Document 1, a head pulley device is usually provided at the tunnel entrance, and the conveyor belt circulates between the tailpiece cart and the head pulley device. The excavation waste sent to the head pulley device is then transported outside the continuous belt conveyor device.

Patent No. 6426813

Although not described in the above Patent Document 1, conventional extension belt conveyors are very long, with a total length of approximately 130 m, for example, and the extension belt conveyor (particularly the equipment group including the tailpiece cart, storage cassette, main drive, and head pulley device) cannot be installed during the initial tunnel excavation. For this reason, after first excavating a certain amount (usually about 200 m) to secure installation space inside the tunnel, tunnel construction is temporarily halted and the extension belt conveyor installation work is carried out. The construction period required for the installation work is, for example, about one month.

As tunnel construction must be interrupted to install the conveyor, losses occur in the tunnel construction process, leading to reduced economic efficiency. In addition, during the initial excavation, the excavation waste cannot be transported using the extension belt conveyor, reducing the efficiency of the transport work. For this reason, it is desirable to reduce the initial overall length of the extension belt conveyor. If the extension belt conveyor can be installed with a shorter initial excavation distance, the decrease in transport work efficiency can be reduced. In addition, if the extension belt conveyor can be installed in a space that can be secured before excavation begins, it will be unnecessary to interrupt initial excavation and tunnel construction to perform the installation work, which is expected to shorten the construction process and achieve high transport work efficiency from the start of excavation.

This invention was made to solve the above problems, and one object of the invention is to provide an extension belt conveyor that can suppress the initial overall length.

In order to achieve the above object, the extension belt conveyor of the present invention is an extension belt conveyor capable of extending the transport distance for transporting excavation waste during tunnel excavation, and is equipped with a head pulley device arranged on the rear side in the excavation direction, a tailpiece cart arranged movably on the front side in the excavation direction and with a conveyor belt stretched between it and the head pulley device, and a belt storage arranged between the head pulley device and the tailpiece cart for storing the excess portion of the conveyor belt so that it can be removed, the tailpiece cart includes a belt support section that supports the conveyor belt at its rear end and a storage area provided below the belt support section, and at least a portion of the front side of the belt storage is configured to be storable in the storage area.

In the extension belt conveyor of the present invention, by configuring it as described above, the belt storage, which stores the excess part of the conveyor belt so that it can be fed out, can be stored in a storage area provided below the belt support part of the tailpiece cart located at the front. In other words, the installation range of the tailpiece cart in the tunnel excavation direction and the installation range of the belt storage can be overlapped in the storage area, so the initial overall length can be reduced by the amount of overlap of the installation ranges. This makes it possible to provide an extension belt conveyor that can reduce the initial overall length. Note that since the tailpiece cart moves forward (extends) as the tunnel is excavated, it is sufficient that the belt storage is located in the storage area immediately after installation, and it is not necessary for it to be located in the storage area at any time during excavation.

In the extension belt conveyor according to the present invention, the belt storage preferably includes a fixed pulley bucket arranged on the rear side in the excavation direction and a movable pulley bucket arranged on the front side in the excavation direction, and stores the excess length stretched between the fixed pulley bucket and the movable pulley bucket, and the movable pulley bucket is arranged in the storage area with at least the maximum amount of excess length stored. With this configuration, the movable pulley bucket can be arranged in the storage area of the tailpiece cart, so that the installation space for the belt storage can be effectively reduced. Therefore, the initial overall length of the extension belt conveyor can be effectively reduced.

In this case, preferably, the belt storage further includes a tensioning mechanism that applies tension to the slack portion of the conveyor belt between the fixed pulley bucket and the movable pulley bucket by pulling the movable pulley bucket forward, and in a state where at least the maximum amount of slack portion is stored, in addition to the movable pulley bucket, a part of the tensioning mechanism is arranged in the storage area. With this configuration, in addition to the movable pulley bucket, the tensioning mechanism can also be arranged in the storage area of the tailpiece cart, so that the installation space of the belt storage can be further effectively reduced.

In the configuration in which the tensioning mechanism is disposed in the storage area of the tailpiece dolly, the tensioning mechanism preferably has a wire winding machine disposed rearward of the fixed pulley bucket, a pulley disposed forward of the movable pulley bucket, and a wire member connected to the wire winding machine from the movable pulley bucket via the pulley. With this configuration, the front pulley can be disposed in the storage area of the tailpiece dolly, and the wire winding machine that applies tension to the conveyor belt by towing can be disposed rearward. The pulley can be made smaller than the wire winding machine, so the space occupied by the tensioning mechanism (pulley) in the storage area can be reduced. In addition, even when the pulley is reinstalled to increase the storage capacity of the belt storage during the tunnel excavation process, the wire winding machine does not need to be moved, so the work process can be shortened.

In the above-mentioned belt storage including a fixed pulley bucket on the rear side in the excavation direction and a movable pulley bucket on the front side in the excavation direction, preferably, a support is provided with a rail section that supports the movable pulley bucket so that it can be moved along the tunnel excavation direction, and a support frame section that supports the conveyor frame that supports the conveyor belt that passes above the belt storage, and the multiple supports are configured to be connected sequentially as the tunnel is excavated. With this configuration, supports provided with the rail section of the movable pulley bucket and the support frame section that supports the conveyor frame can be installed as unit structures. This allows the length of the rail section to be extended, so that the amount of storage in the belt storage can be reduced immediately after the installation of the extension belt conveyor to make it as compact as possible, and when sufficient space is secured by excavation, the extended rail section can be used to increase the amount of storage in the belt storage. Furthermore, by providing the support frame section of the conveyor frame on the support, the work of extending the rail section and the work of installing the support frame section to support the conveyor frame can be performed together, improving work efficiency.

In a configuration in which the belt storage includes a fixed pulley bucket on the rear side in the excavation direction and a movable pulley bucket on the front side in the excavation direction, preferably, the fixed pulley bucket includes a main body portion provided with a plurality of pulleys around which the excess length of the conveyor belt is wound, and a belt drive portion provided in the main body portion and circulatingly driving the conveyor belt. With this configuration, the belt drive portion that circulates the conveyor belt can be incorporated into the belt storage (fixed pulley bucket). This makes it possible to effectively reduce the initial overall length of the extension belt conveyor, compared to a configuration in which the belt storage and the belt drive portion (main drive) are provided separately, for example as in Patent Document 1 above.

According to the present invention, as described above, it is possible to provide an extension belt conveyor that can suppress the initial overall length.

1 is a diagram showing an overall configuration of an extension belt conveyor according to a first embodiment. FIG. FIG. 2 is an enlarged view showing the front portion of the tailpiece carriage and belt storage in FIG. 1 in the excavation direction. FIG. 2 is an enlarged view showing a rear portion of the belt storage in the excavation direction and a head pulley device in FIG. 1 . 3 is a schematic cross-sectional view taken along line 400-400 in FIG. 2. This is a schematic diagram showing the initial state of an extension belt conveyor (A), the first extension limit (B), the belt storage in the belt storage (C), and the subsequent state during excavation (D). FIG. 13 is a diagram showing the overall configuration of an extension belt conveyor according to a second embodiment. FIG. 7 is an enlarged view of the crusher-integrated tailpiece truck of FIG. 6 . 7 is a schematic cross-sectional view taken along line 450-450 in FIG. 6. This is a schematic diagram showing the initial state of an extension belt conveyor (A), the first extension limit (B), the belt storage in the belt storage (C), and the subsequent state during excavation (D).

The following describes an embodiment of the present invention with reference to the drawings.

[First embodiment]
The configuration of an extension belt conveyor 100 according to a first embodiment will be described with reference to Figures 1 to 5. The extension belt conveyor 100 is a conveyor device capable of extending the transport distance for transporting excavation debris EM during tunnel excavation. The excavation debris EM is rock masses, earth and sand excavated from the ground during tunnel excavation.

(Outline of the extended belt conveyor)
The stretch belt conveyor 100 according to the first embodiment reduces the installation space of the stretch belt conveyor 100 by suppressing the initial overall length. FIG. 1 exemplarily shows an example in which the stretch belt conveyor 100 is installed (installed) outside the tunnel before the tunnel excavation starts. The stretch belt conveyor 100 may be installed by utilizing the space formed by performing the initial excavation before the installation. Even in this case, as described below, the initial excavation distance can be reduced by suppressing the initial overall length, and the stretch belt conveyor 100 can be installed early.

As shown in FIG. 1, the extension belt conveyor 100 includes a mobile crusher 10, a tailpiece cart 20, a belt storage 30, and a head pulley device 40.

The extension belt conveyor 100 is a transport system in which a conveyor belt 5 for transporting excavation waste EM is wound between a tailpiece cart 20 arranged at the front of the excavation direction (the tunnel excavation surface 1 side in FIG. 1) and a head pulley device 40 arranged at the rear of the excavation direction. While the head pulley device 40 is fixedly installed, the tailpiece cart 20 is installed movably and moves with the advancement of the face. The conveyor belt 5 is a circular endless belt. The conveyor belt 5 is formed longer than the transport length at the initial installation of the extension belt conveyor 100 (the path length from the tailpiece 24 of the tailpiece cart 20 to the head pulley 41 of the head pulley device 40), and in this specification, the excess length of the conveyor belt 5 is called the excess part. As described later, the excess part is stored in the belt storage 30 so that it can be operated out.

In the following explanation, the up-down direction (vertical direction) is referred to as the Z direction, the front-to-back direction along the tunnel excavation direction is referred to as the X direction, and the direction perpendicular to the Z direction and X direction (tunnel width direction) is referred to as the Y direction. Within the X direction, the front side of the excavation direction is referred to as the X1 direction, and the rear side of the excavation direction is referred to as the X2 direction.

In FIG. 1, a mobile crusher 10, a tailpiece cart 20, a belt storage 30 and a head pulley device 40 are arranged in this order toward the rear of the tunnel excavation face 1 in the excavation direction.

(Mobile crusher)
The mobile crusher 10 receives excavated debris EM, crushes it, and breaks it into small pieces, supplying it to an extended belt conveyor 100 at the rear. The mobile crusher 10 has a structure in which a vehicle frame 12 is mounted on crawlers (endless tracks) 11 for movement, and a hopper feeder 13 and a crusher 14 at the rear of the vehicle frame 12 are disposed on the vehicle frame 12. The mobile crusher 10 also has a discharge conveyor 15 extending rearward from the bottom of the crusher 14. The hopper feeder 13 receives debris and supplies it to the crusher 14, where the crusher 14 crushes the debris, and the crushed debris is discharged rearward by the discharge conveyor 15.

(Tailpiece dolly)
The tailpiece cart 20 is disposed behind the mobile crusher 10. The tailpiece cart 20 is disposed movably at the front side in the excavation direction of the extension belt conveyor 100, and the conveyor belt 5 is stretched between the tailpiece cart 20 and the head pulley device 40. As shown in Fig. 2, the tailpiece cart 20 includes a crawler (endless track) 21 for movement, and a body frame 22 mounted on the crawler 21. The body frame 22 is provided with a hopper 23, a tailpiece 24, a tailpiece inclination section 25, and a work platform 26.

The tailpiece 24 defines the front end of the conveyor belt 5 in the excavation direction and has a tail pulley around which the conveyor belt 5 is wound. The tailpiece inclined portion 25 is arranged to extend diagonally upward and rearward from the tailpiece 24 and is configured to support and guide the conveyor belt 5.

A workbench 26 is disposed at the rear end of the tailpiece inclined portion 25. The workbench 26 is provided at a height position corresponding to the rear end of the tailpiece inclined portion 25, so as to protrude rearward from the body frame 22. A conveyor frame 62 that supports the conveyor belt 5 is provided on the workbench 26. The workbench 26 provides an assembly work area for assembling additional conveyor frames 62 as the tailpiece cart 20 extends as it advances through the tunnel. The conveyor belt 5 is supported from the tailpiece 24 to the head pulley device 40 by the tailpiece inclined portion 25 and the conveyor frame 62 that extends rearward from the workbench 26.

The hopper 23 receives the excavated debris EM discharged from the discharge conveyor 15 (see Figure 1) of the mobile crusher 10 and supplies it to the tailpiece inclined section 25. The excavated debris EM fed onto the conveyor belt 5 of the tailpiece inclined section 25 is transported through the tailpiece inclined section 25 and the work platform 26 to the head pulley device 40 (see Figure 1) on the rear side in the excavation direction.

In the first embodiment, the tailpiece cart 20 includes a belt support section 20a that supports the conveyor belt 5 at the rear end in the excavation direction, and a storage area 20b provided below the belt support section 20a. In the example of FIG. 2, the belt support section 20a is configured by a workbench 26. The storage area 20b is the space below the workbench 26. The tailpiece inclined section 25 positions the support position of the conveyor belt 5 above the belt storage 30, and the workbench 26 is provided so as to protrude rearward at a height position corresponding to the support position of the conveyor belt 5, thereby securing the storage area 20b. In the first embodiment, as described below, at least a portion of the front side of the belt storage 30 is configured to be storable in the storage area 20b.

(Belt storage)
Returning to Fig. 1, the belt storage 30 is disposed between the head pulley device 40 and the tailpiece cart 20, and stores the slack portion of the conveyor belt 5 so that it can be removed. The belt storage 30 includes a fixed pulley bucket 31 disposed on the rear side in the excavation direction, and a movable pulley bucket 32 disposed on the front side in the excavation direction, and is configured to store the slack portion stretched between the fixed pulley bucket 31 and the movable pulley bucket 32.

The fixed pulley bucket 31 (see FIG. 3) and the movable pulley bucket 32 (see FIG. 2) each have multiple pulleys. The conveyor belt 5 is crisscrossed between the multiple pulleys to store the excess. The amount of belt storage (length of belt that can be paid out) varies depending on the distance D (see FIG. 1) between the fixed pulley bucket 31 and the movable pulley bucket 32. The excess is paid out as the movable pulley bucket 32 approaches the fixed pulley bucket 31. In the first embodiment, the movable pulley bucket 32 is placed in the storage area 20b (see FIG. 2) with at least the maximum amount of excess stored.

Specifically, as shown in FIG. 4, the work platform 26 stores the movable pulley bucket 32 and the rail section 51 in a gate-shaped straddling structure. On both sides of the movable pulley bucket 32, a part of the vehicle body frame 22 supporting the work platform 26 protrudes rearward (see FIG. 2). As a result, the movable pulley bucket 32 is placed in the storage area 20b below the work platform 26.

As shown in FIG. 2, the movable pulley bucket 32 has a main body 32a provided with multiple (multiple stages) pulleys around which the excess length of the conveyor belt 5 is wound. The movable pulley bucket 32 is installed on a rail portion 51 and is configured to be movable in the front-rear direction (X direction) along the rail portion 51.

The belt storage 30 includes a tensioning mechanism 33 that applies tension to the excess portion of the conveyor belt 5 between the fixed pulley bucket 31 and the movable pulley bucket 32 by pulling the movable pulley bucket 32 forward in the excavation direction. In the first embodiment, in addition to the movable pulley bucket 32, the tensioning mechanism 33 is arranged in the storage area 20b.

Specifically, the tensioning mechanism 33 has a wire winding machine 33a arranged on the rear side (X2 direction side) of the fixed pulley bucket 31 shown in FIG. 3, a pulley 33b arranged on the front side (X1 direction side) of the movable pulley bucket 32 shown in FIG. 2, and a wire member (wire rope) 33c connected from the movable pulley bucket 32 to the wire winding machine 33a via the pulley 33b. In FIG. 2 and FIG. 3, for convenience, the wire member 33c is shown by a dashed line, and the conveyor belt 5 is shown by a two-dot chain line. As shown in FIG. 2, the wire member 33c is turned 180 degrees from the movable pulley bucket 32 by the pulley 33b, and is pulled by the wire winding machine 33a (see FIG. 3) installed on the rear side (X2 direction side). The pulley 33b is stored in the storage area 20b between the movable pulley bucket 32 and the tailpiece dolly 20. The wire winding machine 33a shown in FIG. 3 is located further back in the excavation direction than the head pulley device 40 (below the transport conveyor 70). This reduces the space occupied by the tensioning mechanism 33 between the tailpiece cart 20 and the head pulley device 40.

When the distance D between the fixed pulley bucket 31 and the movable pulley bucket 32 becomes large, the stored conveyor belt 5 may sag due to gravity if only the tensioning mechanism 33 is used. For this reason, a belt support 34 (see FIG. 3) that supports the stored conveyor belt 5 is provided between the fixed pulley bucket 31 and the movable pulley bucket 32. This prevents the belts from coming into contact with each other.

In the first embodiment, as shown in FIG. 3, the fixed pulley bucket 31 includes a main body 31a having multiple (multiple stages) pulleys around which the excess length of the conveyor belt 5 is wound, and a belt drive unit 31b provided on the main body 31a and driving the conveyor belt 5 in a circulating manner.

The belt drive unit 31b is configured to drive one conveyor belt 5 wound around each pulley of the tailpiece cart 20 (tailpiece 24), the head pulley device 40 (head pulley 41), and the belt storage 30. The belt drive unit 31b is the main drive source for driving the conveyor belt 5 of the extension belt conveyor 100 in a circulating manner. The belt drive unit 31b is configured to circulate the conveyor belt 5 by, for example, combining an electric motor and a reducer to rotate the drive pulley 31c around which the conveyor belt 5 is wound.

In the first embodiment, the extension belt conveyor 100 includes a support 50 provided with a rail section 51 that supports the movable pulley bucket 32 so that it can move along the tunnel excavation direction, and a support frame section 52 that supports the conveyor frame 62 that supports the conveyor belt 5 that passes above the belt storage 30. Therefore, in the installation range of the belt storage 30, the rail section 51 and the support frame section 52 are constructed together as part of the support 50. The multiple supports 50 are configured to be sequentially connected as the tunnel is excavated. By connecting the supports 50, the conveyor frame 62 can be extended and the range of movement of the movable pulley bucket 32 can be expanded.

As described above, the belt storage capacity of the belt storage 30 is determined by the interval D (see FIG. 1). In the belt storage 30 of the first embodiment, immediately after the installation of the extension belt conveyor 100 shown in FIG. 1, the interval D is set to a first interval D1, which is smaller than the standard value. As the excavation progresses, the supports 50 (see FIGS. 2 and 3) are sequentially connected and the rail portion 51 is extended, thereby expanding the interval D to the standard value of the second interval D2 (see FIG. 5(C)). This makes it possible to shorten the installation length (interval D) of the belt storage 30 in the early stages of excavation, and then expand the installation length of the belt storage 30 to increase the belt storage capacity when sufficient installation space has been secured.

(Head pulley device)
3, the head pulley device 40 includes a head pulley 41. The head pulley 41 defines the rear end, in the excavation direction, of the conveyor belt 5. A fixed-length (non-extending) transport conveyor 70 is provided behind the head pulley 41, and the transported excavated waste EM is transferred onto the transport conveyor 70.

The head pulley device 40 further includes a belt cleaning device 42, a belt joining stand 43, and a stand frame 44. The belt cleaning device 42 cleans the belt after it has made a U-turn and been transported by the head pulley 41. The belt joining stand 43 provides a work area for performing belt cutting and joining operations when extending the belt in the belt storage 30. The head pulley device 40 has a two-tier structure with the stand frame 44, with the head pulley 41 and belt cleaning device 42 arranged on the upper tier and the belt joining stand 43 arranged on the lower tier.

In the above configuration, the conveyor belt 5 circulates along the following path shown in Figures 1 to 3: tailpiece 24, tailpiece inclined portion 25, work platform 26, head pulley 41, belt cleaning device 42, belt drive unit 31b, belt joint stand 43, belt storage 30 (moving back and forth multiple times between fixed pulley bucket 31 and movable pulley bucket 32), work platform 26, tailpiece inclined portion 25, tailpiece 24. The path from the tailpiece 24 to the head pulley 41 is the transport path for the excavated waste EM toward the mine mouth. The path from the head pulley 41 through the belt storage 30 and back to the tailpiece 24 is the return path toward the front of the excavation direction.

(Extending operation of the extension belt conveyor)
5(A) to (D) show the state of the extension belt conveyor 100 at each stage of tunnel excavation. Fig. 5(A) shows the same state as Fig. 1, and shows the state at the time of installation.

When the stretched belt conveyor 100 is installed, the movable pulley bucket 32 (see FIG. 2), wire member 33c, and pulley 33b (see FIG. 2) of the belt storage 30 are stored in the storage area 20b below the workbench 26 at the rear of the tailpiece dolly 20. In addition, the distance D between the fixed pulley bucket 31 and the movable pulley bucket 32 of the belt storage 30 is set to a first distance D1 that is smaller than the standard value. In other words, the initial position of the movable pulley bucket 32 relative to the fixed pulley bucket 31 is set so that the distance D is the first distance D1. As a result, the initial overall length of the stretched belt conveyor 100 becomes L1, as shown in FIG. 5(A).

Figure 5 (B) shows the state after the tunnel excavation has started. As the tunnel excavation progresses, the mobile crusher 10 and the tailpiece cart 20 advance in the excavation direction. Meanwhile, in the belt storage 30, the excess part of the conveyor belt 5 is unwound according to the movement distance of the tailpiece cart 20. In other words, the mobile pulley bucket 32 moves toward the fixed pulley bucket 31 compared to the initial state of Figure 5 (A), and the interval D becomes smaller than the first interval D1. The conveyor belt 5 is unwound by the amount of the reduction in the interval D. Figure 5 (B) shows a state in which the mobile pulley bucket 32 of the belt storage 30 moves toward the fixed pulley bucket 31 by 1/2 the movement distance of the mobile crusher 10 and the tailpiece cart 20 in response to the advancement of the mobile crusher 10 and the tailpiece cart 20. As the tailpiece cart 20 moves forward, the movable pulley bucket 32 and tensioning mechanism 33 (pulley 33b) move out of the storage area 20b and are left in a standalone state.

As the excess length is unwound, the movable pulley bucket 32 moves toward the fixed pulley bucket 31 (the gap D becomes smaller), but the tensioning mechanism 33 (wire winder 33a) pulls the movable pulley bucket 32 via the wire member 33c, so that the conveyor belt 5 is always given the appropriate belt tension.

When the mobile crusher 10 and the tailpiece cart 20 move forward, an intermediate member 60 is additionally installed, as shown in FIG. 4, which is composed of a plurality of rollers 61 and a conveyor frame 62 that support the conveyor belt 5. The rollers 61 include an upper carrier roller that supports the portion of the conveyor belt 5 that transports the excavated debris EM to the rear (X2 direction), and a lower return roller that supports the portion of the conveyor belt 5 that is returned to the front (X1 direction) after transporting the excavated debris EM, and are each rotatably attached to the conveyor frame 62. The intermediate member 60 is assembled on the workbench 26 at the rear of the tailpiece cart 20, and is sequentially connected to the tip of the existing intermediate member 60.

As shown in FIG. 5(B), in the initial stage when the spacing D of the belt storage 30 during initial excavation is not yet the standard value of the second spacing D2 (see FIG. 5(C)), the intermediate member 60 (conveyor frame 62) is supported by the support base 52 provided on the support 50. In other words, the intermediate member 60 is assembled on the workbench 26 and supported by the support base 52 of the support 50 additionally installed below the workbench 26. In this way, the support 50 and intermediate member 60 are constructed and extended sequentially as excavation proceeds. Additional supports 50 are installed until the spacing D of the belt storage 30 can be expanded to the second spacing D2.

As the tunnel is excavated, the mobile crusher 10 and tailpiece cart 20 continue to move forward, and when the belt storage amount corresponding to the first interval D1 of the belt storage 30 runs out, the mobile crusher 10 and tailpiece cart 20 cannot be extended any further. Figure 5 (B) shows the initial extension limit, and the mobile pulley bucket 32 of the belt storage 30 has reached its travel limit.

In the first embodiment, the belt storage amount (first interval D1) of the belt storage 30 at the time of initial installation is set to an extension length that allows the interval D of the belt storage 30 to be expanded to the standard value of the second interval D2 (see FIG. 5(C)). Therefore, when the extension limit of FIG. 5(B) is reached, the rail portion 51 is extended to a length that allows the movable pulley bucket 32 to be relocated to a position that is the second interval D2 away from the fixed pulley bucket 31.

Then, the conveyor belt 5 is restored to the belt storage 30. First, the pulley 33b is moved to the front end of the rail section 51 (see FIG. 5C). Then, in the belt jointing frame 43 of the head pulley device 40, the conveyor belt 5 is cut, and one end of a newly prepared belt roll (not shown) is joined to the face side end of the cut section. Then, the movable pulley bucket 32 of the belt storage 30 is moved toward the face, so that the belt of the belt roll (not shown) is transferred to the belt storage 30 and stored (replenished). At this time, the movable pulley bucket 32 is moved forward to a position that is the second distance D2 (see FIG. 5C) from the fixed pulley bucket 31. Finally, in the belt jointing frame 43, the other belt end of the belt roll (not shown) is joined to the mouth side end of the cut section. This completes the restoration (replenishment) and endless of the conveyor belt 5.

Figure 5 (C) shows the state in which the conveyor belt 5 has been re-stored in the belt storage 30. The total length L2 of the extension belt conveyor 100 in this state is the regular length.

Figure 5 (D) shows the actual excavation state after the extension belt conveyor 100 is set to the normal length. After the extension belt conveyor 100 is extended to the normal length, only the mobile crusher 10 and the tailpiece cart 20 advance along with the tunnel excavation. Since there is no need to add rail sections 51, the intermediate members 60 that are added as the tunnel is excavated are supported and fixed by a support material called a knee rest 65 (see Figure 5 (D)) installed on the tunnel wall, and no additional supports 50 are installed. In other words, the conveyor belt 5 is supported and circulated between the tailpiece cart 20 and the belt storage 30 by the intermediate members 60 attached to the knee rest 65.

(Effects of the First Embodiment)
In the first embodiment, the following effects can be obtained.

In the first embodiment, as described above, the tailpiece cart 20 includes a belt support part 20a that supports the conveyor belt 5 at the end on the rear side in the tunnel excavation direction, and a storage area 20b provided below the belt support part 20a, and at least a part of the front side of the belt storage 30 is configured to be stored in the storage area 20b. As a result, the belt storage 30 that stores the excess part of the conveyor belt 5 so that it can be fed out can be stored in the storage area 20b provided below the belt support part 20a of the tailpiece cart 20 arranged at the front. In other words, the installation range of the tailpiece cart 20 in the tunnel excavation direction and the installation range of the belt storage 30 can be overlapped in the storage area 20b, so that the initial total length L1 can be suppressed by the amount of overlap of the installation ranges. As a result, it is possible to provide an extension belt conveyor 100 that can suppress the initial total length L1.

In the above example, from Figures 5(A) and 5(C), it can be seen that if the extension belt conveyor 100 is installed with its normal length (total length L2), initial excavation of the tunnel is required up to the position shown in Figure 5(C). In contrast, in the first embodiment, the initial total length L1 of the extension belt conveyor 100 is shortened, making initial excavation unnecessary.

In the first embodiment, as described above, the belt storage 30 includes a fixed pulley bucket 31 arranged on the rear side in the excavation direction and a movable pulley bucket 32 arranged on the front side in the excavation direction, and stores the excess portion stretched between the fixed pulley bucket 31 and the movable pulley bucket 32, and the movable pulley bucket 32 is arranged in the storage area 20b when at least the maximum amount of excess portion is stored. This allows the movable pulley bucket 32 to be arranged in the storage area 20b of the tailpiece cart 20, so that the installation space for the belt storage 30 can be effectively reduced. Therefore, the initial overall length L1 of the extension belt conveyor 100 can be effectively suppressed.

In addition, in the first embodiment, as described above, the belt storage 30 further includes a tensioning mechanism 33 that applies tension to the excess portion of the conveyor belt 5 between the fixed pulley bucket 31 and the movable pulley bucket 32 by pulling the movable pulley bucket 32 forward, and in addition to the movable pulley bucket 32, the tensioning mechanism 33 is arranged in the storage area 20b. As a result, in addition to the movable pulley bucket 32, the tensioning mechanism 33 can also be arranged in the storage area 20b of the tailpiece cart 20, so that the installation space of the belt storage 30 can be further effectively reduced.

In the first embodiment, as described above, the tensioning mechanism 33 has a wire winding machine 33a arranged on the rear side of the fixed pulley bucket 31, a pulley 33b arranged on the front side of the movable pulley bucket 32, and a wire member 33c connected to the wire winding machine 33a from the movable pulley bucket 32 via the pulley 33b. This allows the front pulley 33b to be arranged in the storage area 20b of the tailpiece cart 20, and the wire winding machine 33a, which applies tension to the conveyor belt 5 by pulling, to be arranged on the rear side. The pulley 33b can be made smaller than the wire winding machine 33a, so the space occupied by the tensioning mechanism 33 (pulley 33b) in the storage area 20b can be reduced. In addition, even when the pulley 33b is reinstalled to increase the storage capacity of the belt storage 30 during the tunnel excavation process, the wire winding machine 33a does not need to be moved, so the work process can be shortened.

In the first embodiment, as described above, the support 50 is provided with a rail portion 51 that supports the movable pulley bucket 32 movably along the tunnel excavation direction, and a support frame portion 52 that supports the conveyor frame 62 that supports the conveyor belt 5 passing above the belt storage 30. The multiple supports 50 are configured to be sequentially connected as the tunnel is excavated. This allows the support 50, which is provided with the rail portion 51 of the movable pulley bucket 32 and the support frame portion 52 that supports the conveyor frame 62, to be additionally installed as a unit structure. This allows the length of the rail portion 51 to be extended, so that the amount of storage in the belt storage 30 is reduced immediately after the installation of the extension belt conveyor 100 to make it as compact as possible, and when sufficient space is secured by excavation, the extended rail portion 51 can be used to increase the amount of storage in the belt storage 30. Furthermore, by providing the support base portion 52 of the conveyor frame 62 on the support body 50, the extension work of the rail portion 51 and the installation work of the support base portion 52 can be performed together, improving work efficiency.

In addition, in the first embodiment, as described above, the fixed pulley bucket 31 includes a main body 31a provided with a plurality of pulleys around which the excess length of the conveyor belt 5 is wound, and a belt drive unit 31b provided on the main body 31a and driving the conveyor belt 5 in a circulating manner. This allows the belt drive unit 31b that drives the conveyor belt 5 in a circulating manner to be incorporated into the belt storage 30 (fixed pulley bucket 31). Therefore, for example, compared to a configuration in which the belt storage and the belt drive unit (main drive) are provided separately, the initial overall length of the extension belt conveyor 100 can be effectively suppressed.

[Second embodiment]
Next, a second embodiment will be described with reference to Figures 6 to 9. In this second embodiment, unlike the first embodiment in which the mobile crusher 10 and the tailpiece cart 20 are provided separately, an example in which a crusher is provided on the tailpiece cart 120 will be described. In the drawings, the same components as those in the first embodiment are shown with the same reference numerals as those in the first embodiment, and the description thereof will be omitted.

As shown in FIG. 6, the stretched belt conveyor 200 of the second embodiment is provided with a crusher-integrated tailpiece cart 120, a belt storage 30, and a head pulley device 40, in this order, behind the tunnel excavation face 1. In other words, the stretched belt conveyor 200 of the second embodiment does not have a mobile crusher 10, and instead of the tailpiece cart 20 of the first embodiment, a crusher-integrated tailpiece cart 120 is provided.

As shown in FIG. 7, the tailpiece cart 120 includes a crawler (endless track) 121 for movement, and a vehicle body frame 122 mounted on the crawler 121. The vehicle body frame 122 is provided with a hopper feeder 123, a crusher 124, and a discharge conveyor 125. The hopper feeder 123 receives excavated debris EM and supplies it to the crusher 124. The crusher 124 is disposed behind the hopper feeder 123, and crushes the supplied excavated debris EM into small pieces. The discharge conveyor 125 sends the debris crushed by the crusher 124 to the hopper 126 at the rear.

The vehicle frame 122 is further provided with a hopper 126, a tailpiece 127, and a tailpiece inclination section 128. The hopper 126 receives the waste sent out from the discharge conveyor 125 and supplies it to the tailpiece inclination section 128 arranged below. The tailpiece 127 is the front end section in the excavation direction of the extension belt conveyor 200, and has a tail pulley around which the conveyor belt 5 is wound. The tailpiece inclination section 128 is arranged to extend diagonally upward and rearward from the tailpiece 127, and is configured to support and guide the conveyor belt 5.

A workbench 129 is provided behind the tailpiece inclined portion 128 for assembling the additional conveyor frame 62 that is installed when the tailpiece carriage 120 advances in conjunction with tunnel excavation. In the second embodiment, the workbench 129 is connected to the tailpiece carriage 120 at a position away from the tailpiece carriage 120 so as to move integrally with the tailpiece carriage 120.

As shown in FIG. 8, the work platform 129 is provided with a sled 129b at the bottom and is connected to the tailpiece cart 120 (body frame 122) via a towing beam 129c. As a result, the work platform 129 moves together with the tailpiece cart 120 by being towed by the tailpiece cart 120. The length of the towing beam 129c is set so that the work platform 129 is located at the rear end of the tailpiece inclined portion 128. The work platform 129 may be towed by a fixed method in which it is fixed integrally to the body frame 122 instead of the towing beam 129c, or may be equipped with wheels or the like instead of the sled 129b. For convenience, the belt storage 30 shown in FIG. 6 is omitted in FIG. 7. On the other hand, FIG. 8 also illustrates the belt storage 30 (mobile pulley bucket 32) located below the work platform 129.

The tailpiece cart 120 includes a belt support section 120a that supports the conveyor belt 5 at the rear end in the excavation direction, and a storage area 120b provided below the belt support section 120a. In the second embodiment, the belt support section 120a is composed of a work table 129 and a tailpiece tilt section 128. The storage area 120b is the space below the work table 129 and the tailpiece tilt section 128.

The tailpiece inclined portion 128 extends obliquely upward and rearward from the vehicle frame 122, forming a storage area 120b below the tailpiece inclined portion 128. As shown in FIG. 8, the workbench 129 includes a gate-shaped frame 129a having a pair of legs with a sled 129b, and an intermediate member 60 is installed on the upper surface of the frame 129a. The frame 129a is formed in a shape that straddles the belt storage 30 in a gate shape. Inside this gate-shaped frame 129a, a storage area 120b is formed to store the mobile pulley bucket 32, the rail portion 51, and the pulley 33b. Although not shown, the rear portion of the vehicle frame 122 that supports the tailpiece inclined portion 128 is also formed to straddle the belt storage 30 in a gate shape. As a result, at least a portion of the belt storage 30 on the front side in the excavation direction can be stored in the storage area 120b.

The configuration of the belt storage 30 and head pulley device 40 is the same as in the first embodiment described above, so a description will be omitted.

(Extending operation of the extension belt conveyor)
As shown in Fig. 9(A), when the stretch belt conveyor 200 of the second embodiment is installed, the movable pulley bucket 32, the wire member 33c, and the pulley 33b of the belt storage 30 are stored in the storage area 120b provided at the rear of the tailpiece dolly 120 and below the tailpiece inclined portion 128. In the second embodiment, the entire movable pulley bucket 32 is stored inside the storage area 120b. In addition, in the initial installation state of Fig. 9(A), the initial position of the movable pulley bucket 32 relative to the fixed pulley bucket 31 is set so that the interval D of the belt storage 30 becomes the first interval D1. As a result, the initial overall length L3 of the stretch belt conveyor 200 is shortened.

As shown in FIG. 9(B), when the tailpiece cart 120 and the work platform 129 move forward in conjunction with excavation, the movable pulley bucket 32, the wire member 33c, and the pulley 33b move out of the storage area 20b.

The rest of the configuration is the same as in the first embodiment above, so only an overview will be explained.

Figure 9(B) shows the initial extension limit. The movable pulley bucket 32 of the belt storage 30 has reached its movement limit. The support 50 added between Figures 9(A) and 9(B) has caused the rail portion 51 to reach an extension length that allows the belt storage 30 to be expanded to the second interval D2. Therefore, when the conveyor belt 5 is to be re-stored in the belt storage 30, the movable pulley bucket 32 is moved to a position that is the second interval D2 from the fixed pulley bucket 31. Then, the belt of a newly prepared belt roll (not shown) is transferred to the belt storage 30, and the conveyor belt 5 is re-stored in the belt storage 30 at a standard storage amount that is larger than the initial storage amount.

Figure 9 (C) shows the state in which the conveyor belt 5 has been re-stored in the belt storage 30. The total length L4 of the extension belt conveyor 100 in this state is the regular length.

Figure 9 (D) shows the actual excavation state after the extension belt conveyor 100 has been set to the regular length and excavation has continued. Leaving the belt storage 30 behind, only the tailpiece cart 120 and the work platform 129 move forward with the tunnel excavation. Between the tailpiece cart 120 (work platform 129) and the belt storage 30, the intermediate member 60, which is added as the extension proceeds, is supported by a knee rest 65 installed on the tunnel wall, thereby supporting and circulating the conveyor belt 5.

(Effects of the Second Embodiment)
In the second embodiment, the following effects can be obtained.

In the second embodiment, as in the first embodiment, the tailpiece cart 120 includes a belt support portion 120a at the rear end in the excavation direction and a storage area 120b provided below the belt support portion 120a, and at least a portion of the front side in the excavation direction of the belt storage 30 is configured to be stored in the storage area 120b, thereby providing an extension belt conveyor 100 that can reduce the initial overall length L3.

In addition, in the second embodiment, as described above, the tailpiece cart 120 is equipped with a crusher 124, so the initial overall length L3 required to install the extension belt conveyor 200 can be further shortened compared to the configuration in which the tailpiece cart 20 and the mobile crusher 10 are separately provided and arranged side by side as in the first embodiment.

In addition, in the second embodiment, as described above, the entire movable pulley bucket 32 is stored in the storage area 120b, so the overlapping portion (the length of the stored portion) of the installation area between the belt storage 30 and the tailpiece cart 120 can be made larger. The larger the overlapping portion of the installation areas, the more effectively the initial overall length L3 of the extension belt conveyor 200 can be shortened.

The other effects of the second embodiment are the same as those of the first embodiment.

[Modification]
The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than the description of the above embodiments, and further includes all modifications (alternatives) within the meaning and scope of the claims.

For example, in the first and second embodiments described above, the fixed pulley bucket 31 is provided with a belt drive unit 31b that drives the conveyor belt 5 in a circulating manner, but the present invention is not limited to this. In the present invention, the fixed pulley bucket 31 and the belt drive unit 31b may be provided separately.

In the above first and second embodiments, an example is shown in which the head pulley device 40 is provided with the belt connection stand 43, but the present invention is not limited to this. In the present invention, the head pulley device 40 and the belt connection stand 43 may be provided separately.

In the above first and second embodiments, an example was shown in which the tensioning mechanism 33 was arranged in the storage area 20b (120b) of the tailpiece carriage 20 (120), but the present invention is not limited to this. In the present invention, the tensioning mechanism 33 may be arranged outside the storage area 20b (120b).

In the above first and second embodiments, the tensioning mechanism 33 is configured with the wire winder 33a, the pulley 33b, and the wire member 33c, but the present invention is not limited to this. For example, the wire winder 33a may be arranged instead of the pulley 33b, and the wire winder 33a may pull the movable pulley bucket 32 without using the pulley 33b. In this case, the wire winder 33a may be arranged in the storage area 20b (120b). In addition, the tensioning mechanism 33 may be configured to apply tension to the excess portion of the conveyor belt 5 using, for example, a hydraulic jack mechanism.

In the above first and second embodiments, an example of a configuration is shown in which the support 50 provided with the rail portion 51 and the support base portion 52 is sequentially connected as the tunnel is excavated until the extension belt conveyor 100 is extended to the standard length, but the present invention is not limited to this. In the present invention, the rail portion 51 and the support base portion 52 may be constructed separately without using the support 50.

In the above first and second embodiments, the tailpiece inclined portion 25 (128) is used to guide and support the conveyor belt 5 above the storage area 20b (120b), but the present invention is not limited to this. Instead of the tailpiece inclined portion, the tailpiece may be disposed at a position above the storage area to guide and support the conveyor belt 5 horizontally rearward. In this case, the tailpiece cart may be provided with an ascending conveyor that transports the input excavated debris EM upward to the installation position of the tailpiece above the storage area, or the input position of the excavated debris EM (installation position of the hopper) itself may be set above the storage area.

5 Conveyor belt 20, 120 Tailpiece cart 20a, 120a Belt support section 20b, 120b Storage area 30 Belt storage 31 Fixed pulley bucket 31a Main body section 31b Belt drive section 32 Movable pulley bucket 32a Main body section 33 Tensioning mechanism 33a Wire winding machine 33b Pulley 33c Wire member 40 Head pulley device 50 Support 51 Rail section 52 Support frame section 62 Conveyor frame 100, 200 Extension belt conveyor

Claims (6)

An extension belt conveyor capable of extending the conveying distance for conveying excavation waste during tunnel excavation,
A head pulley device arranged on the rear side in the excavation direction;
A tailpiece cart is movably arranged at the front side in the excavation direction, and a conveyor belt is stretched between the tailpiece cart and the head pulley device;
a belt storage disposed between the head pulley device and the tailpiece cart, for storing an excess portion of the conveyor belt in a retractable manner;
The tailpiece cart includes a belt support portion at a rear end portion thereof for supporting the conveyor belt, and a storage area provided below the belt support portion,
An extension belt conveyor, wherein at least a portion of a front side of the belt storage is configured to be stored in the storage area. The belt storage includes a fixed pulley bucket arranged on the rear side in the excavation direction and a movable pulley bucket arranged on the front side in the excavation direction, and stores the excess portion stretched between the fixed pulley bucket and the movable pulley bucket,
2. The stretch belt conveyor of claim 1, wherein the movable pulley bucket is positioned in the storage area with at least a maximum amount of the slack stored therein. The belt storage further includes a tensioning mechanism that applies tension to the excess portion of the conveyor belt between the fixed pulley bucket and the movable pulley bucket by pulling the movable pulley bucket forward in the excavation direction,
3. The stretch belt conveyor of claim 2, wherein a portion of the tensioning mechanism is disposed in the storage area in addition to the movable pulley bucket with at least a maximum amount of the slack stored . The stretch belt conveyor according to claim 3, wherein the tensioning mechanism includes a wire winder arranged rearward of the fixed pulley bucket, a pulley arranged forward of the movable pulley bucket, and a wire member connected from the movable pulley bucket to the wire winder via the pulley. The conveyor belt storage further includes a support provided with a rail portion that supports the movable pulley bucket movably along the tunnel excavation direction, and a support frame portion that supports a conveyor frame that supports the conveyor belt that passes above the belt storage,
The stretch belt conveyor according to any one of claims 2 to 4, wherein a plurality of said supports are configured to be sequentially connected together as the tunnel is excavated. The stretchable belt conveyor according to any one of claims 2 to 5, wherein the fixed pulley bucket includes a main body having a plurality of pulleys around which the excess length of the conveyor belt is wound, and a belt drive unit provided on the main body for driving the conveyor belt in a circulating manner.

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