JP3338584B2 - 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 method for excavating a ground by rotating a cutter disk concentrically with the axis of an excavator and crushing gravel contained in excavated earth and sand by an eccentrically rotating cone rotor. The present invention relates to an improvement of the configured excavator.

[0002]

2. Description of the Related Art The applicant of the present invention can deal with all types of soil from bedrock to boulders and cohesive soil.
We have developed an excavator that is effective for excavating clayey soil (Japanese Patent Publication No. 7-995). This excavator has a cutter disk attached with a roller bit and rotates concentrically with the axis of the main body, a cone rotor that rotates eccentrically with respect to the axis of the main body, and a crankshaft having a preset eccentric part, The cutter disc is mounted non-rotatably on the tip of the crankshaft, and the cone rotor is rotatably mounted on the eccentric part of the crankshaft.

[0003] The excavator is provided with thrust by a main pushing device installed in a starting shaft, excavates rock or boulder layers or viscous soil by a roller bit attached to a cutter disk, and takes in earth and sand into a shaving chamber to cut the soil. It is possible to excavate tunnels or lay pipes in the ground by crushing the gravel contained in the earth and sand taken into the earth chamber by an eccentrically rotating cone rotor and discharging the crushed stones and earth and sand to the outside. It is.

In the above-mentioned excavator, the shaft is formed as a cantilever-shaped crankshaft, and an eccentric portion is formed in a cross section of the support portion supported by the partition wall, and the same as the support portion in the cross section of the eccentric portion. A tip having an axis is formed. For this reason, the crankshaft must be formed by sequentially reducing the diameter of the eccentric portion, which is the mounting portion of the cone rotor, and the tip portion, which is the mounting portion of the cutter disk, formed from the support portion toward the front end portion.

On the other hand, the power for driving the cutter disk when excavating the ground is transmitted through the crankshaft, so that the diameter of the distal end of the crankshaft and the coupling structure between the distal end and the cutter disk are transmitted. It is designed according to design conditions such as power to be driven and the number of revolutions.

[0006]

When power is transmitted to a cutter disk via a shaft, it is common that both are connected by a key or a spline. However, when the depth of the key groove increases with respect to the shaft diameter, the shape factor increases and the stress concentration on the groove increases. Therefore, in the excavator, the shaft and the cutter disk are connected by a spline.
For this reason, it is necessary to machine the multi-slots forming the spline on the tip end of the shaft and the boss of the cutter disk with accurate dimensions and parallelism, and there is a problem that the machining cost increases.

The cone rotor is supported on a crankshaft via roller bearings, and the bearings are lubricated by an oil bath method. For this reason, a sealing device is provided at both end surfaces of the cone rotor to prevent leakage of lubricating oil or to prevent intrusion of muddy water in the earth shaving chamber. This sealing device has to be a complicated mechanism due to the eccentric rotation of the cone rotor, and there is a problem that the processing cost and the replacement cost due to the consumption of the sealing device are high.

An object of the present invention is to provide an excavator capable of reducing the cost by reducing the machining of the shaft and the machining of the seal portion.

[0009]

In order to solve the above problems, an excavator according to the present invention comprises a cutter disc for excavating the ground, a cone rotor for crushing excavated gravel, and a shaft for mounting the cutter disc and the cone rotor. In the excavator having an excavator, the shaft is configured as an eccentric shaft including a shaft portion substantially coinciding with the axis of the excavator and an eccentric portion eccentrically eccentric from the shaft portion by a predetermined distance, and the boss of the cutter disk has the eccentric shaft. A hole having an eccentric amount equal to the eccentric amount of the eccentric portion in the eccentric shaft is formed, the cone rotor is rotatably mounted on the eccentric portion of the eccentric shaft, and the cutter disc is inserted through the hole. It is configured so as to be non-rotatably mounted on the tip of the eccentric shaft.

[0010]

In the above-mentioned excavator, the shaft is formed as an eccentric shaft composed of a shaft portion coinciding with the axis of the excavator and an eccentric portion eccentric from the shaft portion. Can be made approximately equivalent. Also, a hole with an eccentric amount equal to the eccentric amount of the eccentric shaft is formed in the boss of the cutter disk,
By fitting the tip of the eccentric shaft to this hole and attaching the cutter disk, the cutter disk can be mounted so as not to rotate with respect to the eccentric shaft, and the cutter disk can be concentrically rotated with the excavator. Therefore, it is possible to make the tip of the eccentric shaft thicker than the tip of the crankshaft, and it is possible to improve the degree of freedom of the structure when connecting the tip and the cutter disk. That is, since the shaft diameter of the tip portion can be increased, when a groove is formed, the ratio of the groove to the shaft diameter is reduced, and the shape factor can be reduced to reduce stress concentration. Therefore, the cutter disk can be key-coupled, and the cutter disk can be coupled by processing one keyway, thereby reducing the processing on the shaft and the processing cost.

By mounting both the cutter disk and the cone rotor on the eccentric portion of the eccentric shaft, there is no relative eccentric rotation between the two. For this reason, the configuration of the seal portion can be simplified, and the processing cost can be reduced.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the above excavator will be described below with reference to the drawings. FIG. 1 is a view for explaining the overall configuration of the excavator,
FIG. 2 is a diagram illustrating the main part of the excavator.

An excavator A shown in the figure is propelled by a main pushing device installed in a starting shaft (not shown). In this propulsion process, the cutter disk 16 is driven to excavate the ground, and is included in the excavated earth and sand. The crushed gravel is discharged to the outside while being crushed to form a tunnel in the ground, or the excavator A can be followed by a plurality of fume pipes so as to lay a pipeline by the pipes.

The excavator A is constructed such that the shield body 1 and the tail shield 2 are connected by two hydraulic jacks 3 and a rod (not shown) so as to be able to bend. When the excavator A deviates from the planned laying line during propulsion, pressure oil is independently supplied to each hydraulic jack 3 to deflect the shield body 1 and the tail shield 2 to a desired angle to control the direction. It is configured to go and match the planned laying line.

A partition wall 4 is provided at a predetermined position of the shield main body 1. A earth shaving chamber 5 is formed on the front side (left side in FIG. 1) of the partition wall 4, and the cabin is mounted on the rear side (right side in FIG. 1). A chamber 6 is formed. The partition walls 4 are arranged at a predetermined distance from each other,
A casing member 7 having an axial center coinciding with the axial center of the shield main body 1 is fixed to the plates 4a and 4b.
A pair of bearings 7a and 7b are disposed on the casing member 7, and the eccentric shaft 8 is rotatably supported by these bearings 7a and 7b.

A support wall 9 is provided at a predetermined position of the shield body 1 on the side of the cabin 6, and a motor 10 a as a driving means for driving the eccentric shaft 8 and a reduction gear 10 b are fixed to the support wall 9. . The output shaft 10c of the driving means is formed as a spline shaft, and is configured to be able to transmit the power of the motor 10a to the eccentric shaft 8 by engaging with a spline 8a formed at the shaft end of the eccentric shaft 8. .

In the cabin 6, there is disposed an optical system 11 for monitoring a deviation from a scheduled laying line accompanying the propulsion of the excavator A and for monitoring a correction amount when directional control is performed. The optical system 11 includes a plurality of mirrors 11a to 11c and a target 11d.
And a television camera 11e. An incident spot of the laser beam 12 irradiated along the planned laying line and a reflection spot from the mirror 11a are imaged on a target 11d, and these spots are monitored by the television camera 11e while excavating. When two spots are separated from the scheduled laying line of the machine A due to a deviation, the hydraulic jack 3 is operated so as to make these spots coincide with each other, so that the direction control can be performed.

The eccentric shaft 8 is supported by bearings 7a and 7b provided on the casing member 7 and is rotatably concentric with the axis of the shield main body 1. The eccentric shaft 8 is formed on the front side of the support portion 8b and has a shaft. Eccentric part 8c eccentric by a predetermined distance from the center
And an end portion 8d formed in front of the eccentric portion 8c and having the same axis as the eccentric portion 8c. The amount of eccentricity of the eccentric portion 8c with respect to the supporting portion 8b is set in advance in the design stage according to the size of the gravel to be crushed.

A pair of bearings 13 are arranged on the eccentric portion 8c.
A cone rotor 14 is rotatably mounted on the bearing 13. That is, the cone rotor 14 is configured to freely rotate about the eccentric portion 8c of the eccentric shaft 8 without applying a special driving force.

The cone rotor 14 crushes the gravel with the tapered portion 1a formed at the front end of the shield body 1, and a large load acts on the bearing 13 when the gravel is crushed. For this reason, the cone rotor 14 has a partition wall 4 inside.
An oil chamber 14a is formed which communicates with the inside of the casing member 7 provided in the housing 13. The bearing 13 is lubricated by an oil bath method.

A sealing member 15a having an outer diameter equal to the eccentric outer diameter of the cone rotor 14 is provided on a surface of the casing member 7 facing the cone rotor 14, and faces the casing member 7 of the cone rotor 14. Spring 15c on the surface
The sealing material 15b urged toward the sealing material 15a is disposed by the sealing material 15a, and the sealing materials 15a and 15b prevent the leakage of the lubricating oil and the intrusion of the muddy water in the earth shaving chamber 5 into the oil chamber 14a. .

A cutter disk 16 is non-rotatably mounted on the tip 8d. The cutter disk 16 has a plurality of roller bits 17 for excavating rock and boulder layers, and a plurality of bits for excavating cohesive soil.
18 is installed.

The cutter disk 16 is composed of a boss 16a connected to the tip 8d of the eccentric shaft 8 and a rotary disk 16b fixed to the boss 16a. The boss 16a has a support portion on the eccentric shaft 8. A hole 16c having an eccentric amount equal to the eccentric amount of the eccentric portion 8b and the eccentric portion 8c is formed. And turntable 16
hole with the axis of b being aligned with the axis of the shield body 1
The cutter disk 16 is non-rotatably connected to the eccentric shaft 8 by fitting the tip 16c to the tip portion 8d and connecting them by the key 19.

A seal cap 20 is attached to a surface of the cone rotor 14 facing the cutter disk 16. A lip packing 21 that is in contact with the eccentric portion 8c of the eccentric shaft 8 is provided on an inner peripheral surface of the seal cap 20.
The leakage of the lubricating oil filled in the oil chamber 14a of the cone rotor 14 is prevented. Floating seals 22 are provided on opposite surfaces of the cone rotor 14 and the cutter disk 16 so as to be in contact with each other.
Thus, a secondary seal is formed to substantially completely prevent the leakage of the lubricating oil and the intrusion of the muddy water in the earth shaving chamber 5 into the oil chamber 14a.

In the excavator A constructed as described above, the eccentric shaft 8 rotates when the motor 10a is driven while applying a thrust by the main pushing device. With the rotation of the eccentric shaft 8,
The cone rotor 14 mounted on the eccentric portion 8c of the shaft 8 rotates eccentrically around the axis of the shield body 1.

The hole 16c of the cutter disk 16 has an eccentric portion 8c.
The tip 8d has an eccentric amount equal to the eccentric amount of the shield body 1 and the axis of the turntable 16b is aligned with the axis of the shield body 1.
The cutter disk 16 rotates concentrically with the axis of the shield main body 1 with the rotation of the eccentric shaft 8.

The ground facing the disk 16 is excavated by the rotation of the cutter disk 16, and the earth and sand is taken into the earth shaving chamber 5 from a hole (not shown) formed in the rotary disk 16b.
In the shaving chamber 5, the excavated soil is compacted by the tapered surface 1a of the shield body 1 and the cone rotor 14, and the gravels contained in the excavated soil are crushed. The water is discharged from the chamber to the outside of the excavator A by the exhaust pipe 23.

In the above configuration, in order to rotate the cone rotor 14 eccentrically with respect to the shield main body 1 and to rotate the cutter disk 16 concentrically with the shield main body 1, the cutter disk 16 is formed without using the eccentric shaft 8 as a crankshaft. The diameter of the tip 8d of the eccentric shaft 8 is made substantially equal to the diameter of the eccentric portion 8c by forming an eccentric hole 16c in the boss 16a, that is, the diameter of the tip of the crank shaft is made larger. Therefore, even if the cutter disk 16 and the tip 8d are joined by the key 19, the ratio of the depth of the key groove to the shaft diameter of the tip 8d is reduced, so that the concentration of stress can be reduced. It becomes possible. For this reason, the degree of freedom in selecting the coupling method between the cutter disk 16 and the tip 8d is improved, and the processing cost can be reduced when the coupling method using a key is adopted.

Also, the cutter disk 16 and the cone rotor
14 are arranged concentrically. For this reason, no slippage occurs in the radial direction on the surfaces facing each other, and no relative slippage occurs unless rotation of the cone rotor 14 around the eccentric portion 8c due to crushing of the gravel occurs. Therefore, the sealing method between the cutter disk 16 and the cone rotor 14 can be simplified with the floating seal 22 arranged in contact with each other. In other words, when the portion to be sealed is eccentrically rotated like the cone rotor 14 and the casing member 7, circumferential sliding and radial sliding occur, so that a mechanical seal capable of following sliding in both directions is provided. is necessary. However, if the part to be sealed is merely a slide in the circumferential direction, it is possible to seal with the floating seal 22. Therefore, the structure of the seal portion between the cone rotor 14 and the cutter disk 16 is simple and the durability can be improved, and the processing cost of the seal portion can be reduced.

[0030]

As explained in detail above, in the excavator according to the present invention, the shaft for mounting the cone rotor and the cutter disk is configured as an eccentric shaft, so that the selection of the coupling system between the cutter disk and the eccentric shaft can be made. The degree of freedom can be improved, and when the key combination method is adopted,
The processing cost of the eccentric shaft and the cutter disk can be reduced.

Further, since the cone rotor and the cutter disk are arranged concentrically, only circumferential slippage occurs between the two, thereby simplifying the lubricating oil sealing structure and improving the durability. I can do it. For this reason, it is characterized in that the processing cost of the seal portion can be reduced and the running cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an overall configuration of an excavator.

FIG. 2 is a diagram illustrating a main part of the excavator.

[Explanation of symbols]

 A Excavator 1 Shield body 2 Tail shield 3 Hydraulic jack 4 Partition wall 5 Earth shaving room 6 Inner machine room 7 Casing member 8 Eccentric shaft 8a Spline 8b Support portion 8c Eccentric portion 8d Tip 9 Support wall 10a Motor 10b Reduction gear 10c Output shaft 11 Optical system 12 Laser beam 14 Cone rotor 15a, 15b Seal material 16 Cutter disk 16a Boss 16b Turntable 17 Roller bit 18 bit 19 Key 20 Seal cap 21 Lip packing 22 Floating seal 23 Drain pipe

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) E21D 9/06 301 E21D 9/06 311 E21D 9/08 E21D 9/12

Claims (1)

(57) [Claims] 1. An excavator having a cutter disk for excavating the ground, a cone rotor for crushing excavated gravel, and an axis for mounting the cutter disk and the cone rotor, wherein the axis substantially coincides with the axis of the excavator. A eccentric shaft composed of a shaft portion and an eccentric portion eccentric by a predetermined distance from the shaft portion, and a hole having an eccentric amount equal to the eccentric amount of the eccentric portion in the eccentric shaft in the boss of the cutter disk. An excavator wherein the cone rotor is formed and rotatably mounted on an eccentric portion of the eccentric shaft, and the cutter disc is non-rotatably mounted on a tip of the eccentric shaft through the hole.