JP2001262969A - Excavating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothen supply of a cooling fluid to an excavating position to keep satisfactory excavation efficiency. SOLUTION: A direct motor 2 is formed of a cylindrical rotor 17 having a cylindrical rotating shaft 11 extending through, a cylindrical stator 18 provided on the circumference of the rotor 17, a rotary joint 21 rotatably connected to the rear end of the rotating shaft 11 and having a passage 22 for guiding the compressed air supplied from a compressed air supplying device through a tube 24 to a nozzle 33 provided within the through-hole 11a of the rotating shaft 11. A cylindrical core bit 13 having a bit 15 at the tip is mounted on the rotating shaft 11, and the compressed air is expanded and blown out from the tip of the nozzle 33 into the through-hole 11a of the rotating shaft 11 while rotating the cylindrical shaft 11 at a high speed, and sent to the tip direction of the rotating shaft 11 so as to cool the excavating position by the bit 15 and also discharge chips to the outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavator having a cylindrical core bit having a cutting edge for excavating an object to be excavated in a ring shape.

[0002]

2. Description of the Related Art In recent years, as a method of reinforcing an existing concrete wall, first, the wall is largely pierced, and an iron brace is provided in the opening thus pierced. There is a method in which an anchor disposed on the inner peripheral surface of the opening and an anchor disposed on the inner surface of the opening are integrated with each other by hardening with concrete to thereby reinforce the entire wall. At this time, the anchor is disposed by being accommodated in an anchor hole provided on the inner peripheral surface of the opening. An anchor hole for arranging the anchor has an annular blade 5 made of diamond, a carbide tip or the like at the tip of a cylindrical member as shown in FIG.
0a, and a geared motor 51 for rotating the core bit 50 about its axis. That is, the blade 50a provided at the tip of the core bit 50 is rotated while contacting the concrete 52, which is the object to be excavated, to form the cylindrical core core 53, and the root 53a of the formed core core 53 is manually held. Then, the anchor hole having a diameter of about 20 mm to 35 mm and a depth of about 200 mm is formed.

[0003] When drilling an anchor hole in a structure using this type of drilling equipment, it has been practiced to blow compressed air, liquid nitrogen, or the like to the drilling location by the blade 50a to cool the drilling, thereby increasing drilling efficiency. In the above-described excavator, when spraying the compressed cooling air or liquid nitrogen to the cutting edge, the nozzle is disposed from the outside of the excavation point to the excavation point, and the compressed air or liquid nitrogen is ejected from the nozzle. .

[0004]

However, as described above, if the compressed air or liquid nitrogen is jetted with the nozzle directed to the cutting edge, the adiabatic expansion can be performed not only in the case of liquid nitrogen but also in the case of jetting compressed air. As a result, the temperature of the nozzle is lowered, and the nozzle is frozen by moisture in the surrounding air, so that the jetting may not be performed smoothly, and there is a problem that the excavation efficiency is reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an excavator capable of smoothly extruding a cooling fluid and excavating with good excavation efficiency.

[0006]

According to one aspect of the present invention, there is provided an excavator having a cylindrical core bit having a bit for excavating an object to be drilled in a ring shape, and a motor for rotating the core bit. A drilling rig comprising:
The motor has a cylindrical rotor through which a cylindrical rotating shaft having the core bit attached thereto at a distal end thereof, and a cylindrical stator provided around the outer periphery of the rotor,
A nozzle for injecting the low-temperature fluid toward the front end side is provided in the through hole of the rotating shaft.

As described above, since the cooling fluid is expanded and ejected from the nozzle toward the tip of the rotating shaft in the through-hole of the rotating shaft, when the cooling fluid is ejected from the nozzle, the temperature is increased by adiabatic expansion. Even if the temperature drops, the heat generated inside the motor freezes the surrounding water at the tip of the nozzle and reliably prevents poor cooling fluid jetting caused by the nozzle clogging. Fluid supply can be performed smoothly, whereby good excavation of the excavated object can be maintained. Also,
The cooling of the motor can be performed together with the cooling of the bit, and a cooling structure such as a cooling fan provided in the motor can be eliminated.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An excavator according to an embodiment of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, reference numeral 1 denotes an excavator, and reference numeral 2 denotes a direct motor (motor) constituting the excavator 1. The excavator 1 has a structure in which a support 4 erected on a base 3 supports the direct motor 2 via an up-down mechanism 5.
Are moved along the support 4.

The direct motor 2 has a cylindrical rotating shaft 11 at the center thereof, and a core bit 13 is detachably connected to the tip of the rotating shaft 11 via an adapter 12. The core bit 13 has a structure in which a bit 15 made of a diamond bit is integrally provided in a circumferential direction at a distal end portion of a tube 14 formed in a hollow shape. That is, this direct motor 2
Is a core bit 13 which is a tool directly connected to the rotating shaft 11.
It is a direct type motor that directly rotates. The bit 15 constituting the core bit 13 is, for example, a diamond bit obtained by hardening diamond abrasive grains using a metal bond or a resin bond as a binder.

The rotating shaft 11 is inserted into an insertion hole 17a formed at the center of the rotor 17, and is integrally fixed by, for example, press-fitting into the insertion hole 17a. As shown in FIG. 3, the stator 18 includes magnets M arranged at intervals in the circumferential direction and a steel yoke Y provided between the magnets M to support the magnets M at a predetermined position. Have.

Inside the upper wall 16a and the lower wall 16b of the housing 16, bearings 19a and 19b for rotatably supporting the rotor 17 are provided, respectively. That is, the bearings 19a and 19b support the vicinity of the upper and lower ends of the rotating shaft 11 inserted into the center of the rotor 17, and act on the rotating shaft 11 and the rotor 17 through which the rotating shaft 11 is inserted. It is configured to be able to receive a thrust force and a radial force.

A rotary joint 21 is provided at the rear end of the direct motor 2. The rotary joint 21 is connected to the upper wall 16 a of the housing 16.
, And rotatably connected to the rear end of the rotating shaft 11.

The rotary joint 21 is formed with a flow path 22 communicating with the through hole 11a at the center of the rotary shaft 11, and this flow path 22
1 is open to the side. A tube 24 is connected to the opening 23 opened to the side, and compressed air (cooling fluid) is sent from the tube 24. In addition, a nozzle 33 made of a thin tube having a narrowed portion 32 formed at the tip thereof is provided at an opening 31 of the rotary joint 21 on the side of the through hole 11 a of the flow path 22. The nozzle 33 is provided with the throttle unit 3
The diameter of the tip of the rotary shaft 2 is further increased and is directed toward the tip of the rotating shaft 11.

The compressed air sent from the tube 24 to the flow path 22 of the rotary joint 21 passes through the flow path 22 of the rotary joint 21 and passes through the nozzle 3
3 and the throttle section 32 at the tip of the nozzle 33
And is expanded and injected into the through hole 11a. The air injected from the nozzle 33 is supplied from the inside of the through-hole 11 a to the tube 1 of the core bit 13 connected to the distal end of the rotating shaft 11 via the adapter 12.
4 and supplied to the excavation point by the bit 15.

The direct motor 2 has a rotating shaft 1.
A cooling fan 26 is provided at the distal end of the housing 1, and when the rotating shaft 11 is rotated, air is drawn into the housing 16 from an air inlet 27 formed at the distal end of the housing 16, and is introduced into the direct motor 2. Spraying, then
It is passed through the gap between the stator 18 and the rotor 17 and the space between the magnet M and the yoke Y of the stator 18 and the housing 16, and is discharged to the outside through a discharge port 28 formed in the upper wall 16 a of the housing 16. ing. Reference numeral 25 denotes a housing 16 of the direct motor 2.
On the upper side in such a way that it contacts the rotating shaft 11,
The brush portion is provided in the circumferential direction, and a driving current is supplied from the brush portion 25.

The direct motor 1 having the rotor 17 and the stator 18 may be a brush motor or a brushless motor. Also,
When the rotor 17 has a coil, the stator 18 may be either a magnet or a coil. On the other hand, when the rotor 17 is a magnet, the stator 18 may have a coil.

For one of the rotor 17 and the stator 18 having a magnet, a neodymium-iron-boron-based or samarium-cobalt-based rare earth high-density magnet is used as the magnet.

Next, a case will be described in which a hole is drilled in the concrete C, which is an object to be excavated, using the excavator 1 having the above configuration. First, the direct motor 2 positioned above the column 4 is positioned at a predetermined drilling position of the concrete C so that the axis of the rotating shaft 11 is aligned, and the base 3 is fixed to the concrete C.

When the excavator 1 is installed on the concrete C, the coil of the rotor 17 (or the stator 18) of the direct motor 2 is energized, and the rotor 17
The tube 24 is rotated at a high speed of 2,000 rpm and a tube 24 is supplied from a compressed air supply device (cooling fluid supply source) (not shown).
Compressed air is sent through. In this way, the compressed air sent from the compressed air supply device through the tube 24 is supplied to the nozzle 33 disposed in the through hole 11a of the rotary shaft 11 through the flow path 22 of the rotary joint 21.
And then the throttle section 3 at the tip of the nozzle 33
2, is expanded and injected into the through-hole 11 a and supplied to the tip of the core bit 13.

In this state, the direct motor 2 is lowered by the moving mechanism 5 so that the bit 1 of the core bit 13 connected to the tip of the rotating shaft 11 is moved.
5 is brought into contact with the surface of concrete C. In this way, an annular hole H is formed in the concrete C by the bit 15 rotating at a high speed.

Here, the excavation point by the bit 15 is as follows:
The compressed air expanded and ejected from the nozzle 33 is cooled by being sent in, and the chips are smoothly discharged to the outside by the compressed air, whereby the excavation in the bit 15 is performed smoothly. When the compressed air is ejected from the nozzle 33, the temperature of the nozzle 33 becomes low due to adiabatic expansion.
Is disposed in the through hole 11a of the rotating shaft 11 of
The direct motor 2 is heated by the heat generated when the rotary motor is driven to rotate, and the defective ejection at the nozzle 33 due to the freezing of the water around the nozzle 33 is reliably prevented. Moreover, the direct motor 2 itself is also cooled by the compressed air whose temperature is lowered by adiabatic expansion.

As described above, according to the above-described excavator 1,
Since the structure is such that compressed air is expanded and ejected from the nozzle 33 provided in the through hole 11a of the rotating shaft 11 toward the tip of the rotating shaft 11, the temperature is lowered by adiabatic expansion when ejecting from the nozzle 33. Even if the heat generated inside the direct motor 11
It is possible to reliably prevent compressed air jetting failure caused by surrounding water being frozen at the tip end of the nozzle and clogging the nozzle 33, and to smoothly supply compressed air to the excavation site by the bit 15. Thereby, good excavation of the concrete C can be maintained. Also, bit 13
The cooling of the direct motor 2 can be performed together with the cooling of the direct motor 2, and the cooling structure of the direct motor 2 can be made unnecessary.

In the above example, compressed air is ejected from the nozzle 33 as a cooling fluid. However, for example, a low-temperature fluid such as liquid nitrogen may be supplied and vaporized from the nozzle 33 and ejected. . Also, in the above example,
Although the structure is such that the cooling is performed by the cooling fan 26, the cooling fan 26 may not be provided, and the cooling may be performed only by the cooling fluid ejected from the nozzle 33.

[0024]

As described above, according to the excavator of the present invention, the following effects can be obtained. Claim 1
According to the excavator described, since the cooling fluid is expanded and ejected from the nozzle toward the tip of the rotating shaft in the through-hole of the rotating shaft, the temperature is increased by adiabatic expansion when ejected from the nozzle. Even if the pressure drops, the heat generated inside the motor freezes the surrounding water at the nozzle tip and reliably prevents poor cooling fluid jetting caused by the nozzle clogging. The supply of the cooling fluid can be carried out smoothly, whereby good excavation of the object to be excavated can be maintained. Also,
The cooling of the motor can be performed together with the cooling of the bit, and a cooling structure such as a cooling fan provided in the motor can be eliminated.

[Brief description of the drawings]

FIG. 1 is a side view of an excavator for explaining a configuration and a structure of an excavator according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the direct motor illustrating a configuration and a structure of the direct motor included in the excavator according to the embodiment of the present invention.

FIG. 3 is a cross-sectional view of the direct motor illustrating the configuration and structure of the direct motor according to the embodiment of the present invention.

FIG. 4 is a sectional view of a geared motor illustrating a conventional geared motor to which a core bit is connected.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drilling apparatus 2 Direct motor (motor) 11 Rotating shaft 11a Through hole 13 Core bit 15 Bit 17 Rotor 18 Stator 33 Nozzle C Concrete (excavation object)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshio Imaoka 681 Saedo-cho, Tsuzuki-ku, Yokohama-shi, Kanagawa Prefecture Japan Diamond Co., Ltd. (72) Inventor Kyushu Sato 5-3-13 Sotokanda, Chiyoda-ku, Tokyo Onda Building 201 F-term (reference) 2D029 AA02 5H607 AA02 BB01 BB09 BB14 CC01 CC05 FF10 FF12

Claims (1)

[Claims] 1. An excavating apparatus comprising: a cylindrical core bit having a bit for excavating an object to be excavated in an annular shape; and a motor for rotating the core bit, wherein the motor has the core bit attached to a tip end thereof. And a cylindrical stator provided around the outer periphery of the rotor. A cooling fluid is provided in the through hole of the rotary shaft at a tip side. An excavator characterized by being provided with a nozzle that inflates and jets toward the surface.