JP2002155693A - Cleaning swivel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning swivel, in which the lifetime of a rod-sub or the like is lengthened, maintenance such as seal exchange is facilitated and overall length is shortened and which has a simple mechanism and is economical. SOLUTION: The cleaning swivel is composed of a cylindrical rod-sub in which a front end is connected to a drill rod and a base end can be connected to a rotary percussion drill, a down the hole drill or the like, a cleaning swivel case with a fluid send-in port and a discharge opening for water, air or the like and a sealing case detachably assembled into the cleaning swivel case while being rotatably installed to the rod-sub under the sealed state. A surface hardened layer consisting of a material different from a base material for the rod-sub and having thickness of 0.1 mm or more and hardness HV of 800 or more is formed integrally or separately to the sealing surface of the rod-sub. In the cleaning swivel case, the fluid send-in port is formed to the outside diameter section of an intermediate sealing case, and formed to communicate with the fluid send-in hole of the rod-sub by a fluid send-in path in a space section between the cleaning swivel case and the rod-sub.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning swivel required for a boring operation using a rotary percussion drill or a down-the-hole drill.

[0002]

2. Description of the Related Art A conventional cleaning swivel for a double pipe method such as a rotary percussion drill or a down-the-hole drill is shown in FIG. The extension rod 1 is screwed to the tip of the rod sub 2,
A male screw or female screw 1a screwed to the inner tube is cut at the tip. Further, a coupling 3 which is externally inserted into the extension rod 1 and whose base end is screwed to the tip of the rod sub 2 is provided, and an outer tube is screwed to the tip of this.

A cleaning swivel case 4 is rotatably mounted on the outer periphery of the rod sub 2 via sliding bearings 7 and 8 while being sealed by the rod sub 2 and the packing 5, and has a base end provided with a ring-shaped retainer. The movement in the axial direction was prevented via 6. On the outer surface of the rod sub 2, a hard chrome plating having a thickness of 0.1 mm or less was applied to a carburized and quenched base material.

The cleaning swivel case 4 has a fluid inlet 4a and a fluid outlet 4b, which communicate with the gap 3a between the outer tube and the inner tube and the space 1b of the inner tube, respectively. The base end of the rod sub 2 was provided with a screw 2a for connecting to a drill head such as a rotary percussion drill or a down-the-hole drill. Then, the rod sub 2 is connected to a rotary percussion drill or a down-the-hole drill, etc.
a, the fluid discharge port 4b is connected to a fluid injection hose and a fluid discharge hose, respectively, and is rotated and fed by a rotary percussion drill or a down-the-hole drill.
With the fluid inlet 4a and the fluid outlet 4b stopped, the double pipe rod is rotated and fed.

The conventional cleaning swivel having such a configuration has the following disadvantages. (1) As the wear of the sliding bearing progresses, the cleaning swivel case comes into contact with the rod sub, the packing groove wall of the cleaning swivel case is worn and damaged, and the life of the seal is shortened. Along with this, water leakage occurs during excavation, resulting in inconvenience in use.

(2) Both the packing groove and the part where the sliding bearing is to be assembled must be precisely machined on the cleaning swivel case, which is costly.

(3) Even if the outer diameter sealing surface of the rod sub is worn, fluid leakage occurs similarly to (1), which is a problem. Since the wear time of the sealing surface is proportional to the thickness of the hardened layer on the sealing surface, sufficient life cannot be obtained with hard chrome plating of 0.1 mm or less on the outer surface of the rod sub, and the rod sub is an expensive component. It was uneconomical.

(4) Normally, the seal at the lower end near the excavation surface is severely worn, and the degree of wear is large in the order of the intermediate seal and the upper seal. For this reason, even if it is desired to replace only the lower end seal portion, it is necessary to remove the entire cleaning swivel case fixed with 6 to 8 bolts, which wastes time and labor.

(5) The positions of the fluid inlet and the fluid outlet are arranged at positions sandwiching the two packing parts in the middle part, and the space in the longitudinal direction overlaps and is large.

(6) Repair spraying after the wear becomes severe requires a large amount of build-up, requires the steps of machining, carburizing, quenching, polishing, plating, and polishing, resulting in a large cost and a long manufacturing time. .

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems by using a simple mechanism that has a long service life of a rod sub and the like, facilitates maintenance such as seal replacement, and has a short overall length. It is to provide a typical cleaning swivel.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a tubular rod sub which is connected to a drill rod at a distal end and has a proximal end connectable to a rotary percussion drill or a down-the-hole drill. Or a cleaning swivel case having a fluid inlet and a discharge port for air or the like, and a seal case that is removably incorporated in the cleaning swivel case and is rotatably mounted in a sealed state on the rod sub. A surface hardened layer made of a material different from the base material of the rod sub is integrally formed on the sealing surface of the rod sub or provided separately.

The hardened surface layer of the rod sub has a thickness of 0.1 mm or more and an altitude of HV 800 or more, and the seal case has a sliding bearing function.

Further, the lower end seal case is characterized in that it can be attached and detached while the cleaning swivel is mounted on a rotary percussion drill or a down-the-hole drill.

Further, the invention is characterized in that the surface hardened layer is formed by thermal spraying.

Further, in the cleaning swivel case, a fluid inlet is provided at an outer diameter portion of the intermediate seal case, and a fluid inlet of the cleaning swivel case and the rod sub communicates with a fluid inlet of the rod sub. It is characterized by doing.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. As shown in FIG. 1, a cleaning swivel according to an embodiment of the present invention includes seal units 30, 40, 50, which are seal portions of a cleaning swivel case 20, and a fluid inlet 23 and a fluid inlet 25. Except for this, it has the same configuration as the conventional cleaning swivel (FIG. 2).

The cleaning swivel of the present invention has a circular tube shape having a screw 11 whose tip is connected to a drill rod (not shown) and a screw 12 whose base end is connectable to a rotary percussion drill or a down-the-hole drill (not shown). Cleaning swivel case 2 having rod sub 10, fluid inlet 23 and fluid outlet 24
0, a lower end seal case 30 which is removably incorporated in the cleaning swivel case 20 and is rotatably mounted in a sealed state with the rod sub 10;
It is composed of an intermediate seal case 40 and an upper end seal case 50.

The lower end and intermediate seal cases 30, 4
Reference numerals 0 are sealed by O-rings 90 and 91, respectively, and are fixed to the inside of the cleaning swivel case 20 by bolts 21, respectively. The upper end seal case 50 is sealed by an O-ring 91 and is fixed inside the cleaning swivel case 20 by a retainer 60 and a bolt 22 via a cushion rubber 70 provided on an upper end surface. The lower end seal case 30 is configured to be detachable while the cleaning swivel is mounted on a rotary percussion drill or a down-the-hole drill.

On the sealing surface of the rod sub 10, a hardened surface layer made of a material different from the base material of the rod sub 10 is integrally formed or provided separately. The surface hardened layer is formed by thermal spraying to have a thickness of 0.1 mm or more and a height of HV 800 or more in order to improve abrasion resistance. The lower end seal case 30, the intermediate seal case 40, and the upper end seal case 50 have a sliding bearing function with respect to the rod sub 10, and are configured to be capable of grease lubrication.

The cleaning swivel case 20 includes:
The fluid inlet 23 is located at the outer diameter of the intermediate seal case 40, and as shown in FIGS. 2 and 3, the fluid inlet 25 in the space between the cleaning swivel case 20 and the rod sub 10 as shown in FIG. The rod sub 10 shown
Fluid communication hole 13. Such a configuration makes it possible to reduce the overall length of the cleaning swivel.

The fluid inlet 23 and the fluid outlet 24 are
The cleaning swivel case 20 and the rod sub 10
And the fluid supply passage 25, the fluid discharge passage 26, and the fluid discharge hole 14 of the rod sub 10. Then, the rod sub 10 is connected to a rotary percussion drill or a down-the-hole drill, and the fluid inlet 23 and the fluid outlet 24 are connected to a fluid injection hose and a discharge hose (not shown), respectively, and rotated by a rotary percussion drill or a down-the-hole drill. When the fluid is fed, the double pipe rod is rotated and fed with the fluid inlet 23 and the fluid outlet 24 stopped.

[0023]

According to the present invention described in detail above,
The following excellent effects are provided. (1) The surface hardened layer on the rod sub-seal surface has a thickness of 0.1
mm and higher than HV800
The wear resistance of the rod sub is improved and the service life is extended. In particular,
Since the surface hardened layer is sprayed at the time of manufacture, the amount of overlay is less than the conventional use and repair after overlaying, and the polishing process of machining → carburizing and quenching → polishing → plating → polishing is performed once. This can be omitted, reducing cost and production time.

(2) The seal case is configured to be detachable. In particular, the lower end seal case can be detached independently with the cleaning swivel mounted on a rotary percussion drill or a down-the-hole drill, so that maintenance such as packing replacement is short. Can be done easily on time.

(3) The seal case also has a bearing function,
Since the wall thickness is larger than that of the conventional bearing, the trouble that the swivel case contacts the rod sub due to bearing wear is eliminated.

(4) The inner diameter machining of the swivel case is simplified, and the overall length can be shortened by arranging the fluid inlet port near the fluid outlet port, so that the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view showing a cleaning swivel according to an embodiment of the present invention.

FIG. 2 is a front view (including a partial vertical cross-sectional view) of the cleaning swivel (FIG. 1) according to one embodiment of the present invention as viewed from the upper end.

FIG. 3 is a partial cross-sectional view of a cleaning swivel (FIG. 2) according to an embodiment of the present invention, where (a) is a cross-sectional view along AA,
(B) is BB sectional drawing of (a).

FIG. 4 is a longitudinal sectional view of a conventional cleaning swivel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Extension rod 1a Male thread 1b Inner tube space 2 Rod sub 2a, 11, 12 Female thread 3 Coupling 3a Gap 4, 20 Cleaning swivel case 4a, 23 Fluid inlet 4b, 24 Fluid outlet 5, 80 Packing 6, 60 Retainer 13 Fluid Inlet 14 Fluid Outlet 21, 22 Bolt 25 Fluid Inlet 26 Fluid Discharge 30 Lower Seal Case 31, 41, 51 Packing Groove 32, 52 Preliminary Packing Groove 33, 42, 53 Surface Hardened Layer 40 Intermediate Seal Case 50 Upper end seal case 70 Cushion rubber 90, 91 O-ring

Claims (5)

[Claims] 1. A cylindrical swivel rod having a distal end connected to a drill rod and a proximal end connectable to a rotary percussion drill or a down-the-hole drill, and a cleaning swivel case having a fluid inlet and an outlet for water or air. A seal case detachably incorporated in the cleaning swivel case and rotatably mounted in a sealed state with the rod sub, and a surface made of a material different from the base material of the rod sub on a sealing surface of the rod sub. A cleaning swivel characterized in that a hardened layer is integrally formed or provided separately. 2. The hardened surface layer of the rod sub has a thickness of 0.1 mm.
2. The cleaning swivel according to claim 1, wherein the height is 1 mm or more and the height is HV800 or more, and the seal case has a sliding bearing function. 3. The seal case according to claim 1, wherein a plurality of the seal cases are provided, and the lower seal case is detachable with a cleaning swivel mounted on a rotary percussion drill or a down-the-hole drill. A cleaning swivel according to claim 1 or claim 2. 4. The cleaning swivel according to claim 1, wherein the hardened surface layer is formed by thermal spraying. 5. The cleaning swivel case has a fluid inlet at an outer diameter of the intermediate seal case, and communicates with a fluid inlet of the rod sub through a fluid inlet of a space between the cleaning swivel case and the rod sub. The cleaning swivel according to claim 1, wherein the cleaning swivel is performed.