JP2537133Y2 - Removable drilling blade - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a detachable cutting blade suitable for a cutting head such as an earth auger of a rock drilling machine.

[0002]

2. Description of the Related Art Various types of detachable cutting blades used for rock excavation have been conventionally provided.
As an example thereof, one described in Japanese Utility Model Laid-Open No. 58-115592 is known.

As shown in FIGS. 14 and 15, the detachable excavating blade 1 of the above example includes a holder 3 welded to the outer peripheral portion of a spiral earth auger (hereinafter abbreviated as auger) 2,
The cutter bit 4 is detachably attached to the holder 3 and is roughly constituted. The cutter bit 4 has a blade portion 5 for excavating rock at the tip end side, and a pair of flanges 6 and 7 extending rearward along both widthwise edges of the cutter bit 4 are formed at the rear end side. Have been. On the other hand, a cutter bit 4
A rectangular plate-like support wall portion 8 is formed in close contact with one side surface 6a, 7a of the flanges 6, 7 described above. An extended fitting projection 9 is formed, and the fitting projection 9 and a fitting recess 10 formed between the opposed wall surfaces 6b, 7b of the flanges 6, 7 of the cutter bit 4 are fitted in the front-rear direction. After that, the plurality of bolts 11 are inserted between them in the width direction and tightened, whereby the holder 3 and the cutter bit 4 are firmly fixed, and the detachable drilling blade 1 is configured.

[0004] In the detachable excavating blade 1 configured as described above, the holder 3 is welded with its support wall 8 butted against the outer periphery of the auger 2 as shown in detail in FIG. As a result, the cutter 5 is attached to the excavator in a state where the blade 5 of the cutter bit 4 is directed obliquely downward along the spiral direction of the auger 2. It is sent to the tip side for rock excavation. Further, when the blade portion 5 is worn to the limit or damaged by the continuation of excavation, the bolt 11 is loosened and the cutter bit 4 is removed from the holder 3, and
A new cutter bit 4 is mounted on the holder 3.

[0005]

In the conventional detachable drilling blade 1 described above, the blade 5 of the cutter bit 4 receives a great resistance during excavation.
Must be installed quite firmly. For this reason,
Conventionally, a reinforcing material (not shown) is provided between the detachable digging blade 1 and the auger 2 and welded to the auger 2 so that
Attachment strength has been increased. However,
Since the cutter bit 4 is assumed to be replaced, the reinforcing member cannot be welded, and the improvement of the mounting strength depends on how strongly the holder 3 can be reinforced.

In this regard, in the above-described detachable digging blade 1, the fitting projection 9 arranged at the center in the width direction of the holder 3 is sandwiched between the pair of flanges 6 and 7 of the cutter bit 4. The side surfaces 9a and 9b of the convex portion 9 are covered with the flanges 6 and 7, so that the reinforcing member cannot be welded. Further, as for the fitting projection 9, only the side surface 9c facing the height direction is exposed to the outside from between the flanges 6 and 7, but as is clear from FIG. In this case, the reinforcement is directed to the outer peripheral side of the auger 2, so that it is difficult to pass the reinforcing material between the auger 2 and the auger 2. From the above, the reinforcing material is exclusively the holder 3.
And is welded between the rear end of the auger 2 and the auger 2. However, since the rear end of the holder 3 is farthest from the blade portion 5 which receives the excavation resistance, the effect is thin, and The strength could not be improved sufficiently. That is,
In order to support the holder 3 or the like against the excavation resistance, it is effective to provide a reinforcing material as close to the blade portion 5 as the action point of the excavation resistance as much as possible.

The present invention has been made under such a background, and an object of the present invention is to provide a detachable excavating blade capable of welding a reinforcing member to a position closer to a blade portion of a cutter bit than before.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a detachable excavating blade according to the present invention has a fitting projection of a holder formed along one edge in the width direction of the holder. The side face of the portion facing outward in the holder width direction is exposed to the outside from the fitting recess of the cutter bit.

[0009]

[0010]

According to the detachable digging blade of the above construction, the fitting projection of the holder extends along one edge in the width direction of the holder and the side surface facing outward in the width direction is formed on the outside of the detachable digging blade. When the holder is mounted on an excavating head such as an auger, the reinforcing material can be welded not only to the rear end of the holder but also to the side surface of the fitting projection that faces outward in the width direction.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In addition, the detachable excavating blade according to the present embodiment can be attached to the spiral auger 2 shown in FIG. The mounting state of is referred to FIG.

As shown in FIG. 1, the detachable digging blade 20 according to the present embodiment comprises a holder 21 and a cutter bit 22, and the rear end of the holder 21 is formed in a rectangular parallelepiped shape. A cutting part 23 is formed on the tip side of the bit 22, and the fitting projection 24 on the tip side of the holder 21 and the fitting concave part 25 of the cutter bit 22 are fitted to each other. A bolt 11a inserted in the width direction of the holder 21 from above (from above) and a nut 11b arranged on the holder 21 side are screwed together and tightened, so that the cutter bit 22 is detachably attached to the holder 21. This is common to the above-described conventional example shown in FIG.

However, the detachable digging blade 20 has different features in the fitting projection 24 of the holder 21 and the fitting recess 25 of the cutter bit 22 from the conventional one. Hereinafter, the configuration of the holder 21 and the cutter bit 22 will be described centering on the fitting projection 24 and the fitting recess 25.

As shown in FIG. 1 to FIG.
Is composed of a substantially rectangular parallelepiped base 26 welded to the auger 2, a rectangular flat plate-like support wall 27 formed on the tip side of the base 26, and the fitting projection 24. It is. The fitting projection 24 is formed on the inner surface 2 of the support wall 27.
It is formed in the shape of a prism having a rectangular cross section projecting upward at a constant height from 7 a, extending straight from the tip of the holder base 26 along one edge in the width direction of the holder 21 to the tip of the support wall 27. The side surface 24 a of the fitting projection 24 facing outward in the holder width direction is flush with the side surface 26 a of the holder base 26. Here, the width direction of the holder 21 refers to the vertical direction in FIG. 1, that is, the direction orthogonal to the direction in which the cutter bit 22 is inserted into the holder 21, and the direction parallel to the inner surface 27 a of the support wall 27.

A side surface 24b of the fitting projection 24 facing the center of the holder in the width direction is formed as a flat surface orthogonal to both the inner surface 27a of the support wall 27 and the front end surface 26b of the holder base 26. A curved concave portion 2 which is depressed in an arc shape toward the rear end side of the holder at the intersection of the base 26 and the front end surface 26b of the base 26.
8 are formed. On the other hand, a groove 29 is formed on the tip end side of the fitting projection 24 by cutting the fitting projection 24 by about half in the width direction from the side surface 24a. It reaches the side surface 24 c of the portion 24 and the outer surface 27 b of the support wall portion 27. A notch 30 is formed at the tip end of the fitting projection 24 adjacent to the groove 29 and depressed toward the rear end of the holder. Further, the fitting protrusion 2
4, a plurality (four in the figure) of bolt holes 32 for inserting the bolts 11a for fixing the cutter bit 22 is formed.

A mounting hole 33 is formed in the holder base 26 and extends in the front-rear direction of the holder and opens to the front end surface 26b. A bit restraining pin 34 is fitted in the mounting hole 33. As shown in more detail in FIG.
Is formed by coaxially fitting three spring pins 34a to 34c having different outer diameters.
3 and is fixed to the holder base 26.

As shown in FIGS. 1, 6, 7 and 8,
The cutter bit 22 has the blade portion 23 formed on the front end side, and one flange 35 extending rearward of the cutter bit 22 formed on the rear end side.
One side of the flange 35 in the width direction is fixed to the center of the cutter bit 22 in the width direction over a substantially entire length of the flange 35 by a predetermined width S.
The fitting recess 25 is formed only on one end side in the bit width direction.

As shown in detail in FIGS. 6 to 8, a first projection 36 is formed on the tip side of the fitting recess 25 so as to project in the same direction as the flange 35. Also, the first projection 3
Between the flange 6 and the flange 35, a curved concave portion 38 which is depressed in an arc shape toward the tip end side of the cutter bit 22 is formed,
A second projection 39 is formed below the center. The width dimension S of the fitting recess 25 is set to be equal to the width W of the fitting projection 24 of the holder 21 described above, and its depth dimension, that is, from the rear end of the cutter bit 22 to the second projection 39. The distance H is also set equal to the total length L of the fitting projection 24 (see FIG. 1).

Further, the flange 35 is provided with the flange 3
5, a fitting hole 40 extending in the front-rear direction is formed, and one end thereof is opened to the rear end face 35a of the flange 35. The flange 35 has four bolt holes 41 penetrating the flange 35 in the width direction corresponding to the bolt holes 32 of the holder 21.
The enlarged diameter part 41a for accommodating the head of a is formed.

Then, the holder 2 configured as described above is used.
As shown in FIG. 1, the fitting protrusion 24 and the fitting recess 25 are fitted from the holder front-rear direction so that the side surface 24 b of the fitting protrusion 24 and the side surface 35 of the flange 35 are connected to each other.
b, and in this state, the bolt 11a is inserted from the bolt hole 41 of the cutter bit 22 toward the bolt hole 32 of the holder 21, and the tip end of the bolt 11a is connected to the open end of the bolt hole 32 of the holder 21. Is tightly connected to each other to form the detachable digging blade 20. On this occasion,
The first projection 36 of the cutter bit 22 fits into the groove 29 of the holder 21, and the second projection 39 engages with the notch 30 of the holder 21. Further, the fitting hole 40 of the cutter bit 22 fits with the bit restraining pin 34 of the holder 21.

Here, in the detachable excavating blade 20 of the present embodiment, the fitting projection 24 of the holder 21 is formed along one edge of the holder width direction, so that the fitting projection 24 is formed by the cutter bit 22. The side surface 24 a of the fitting projection 24 is exposed outward in the width direction of the detachable digging blade 20 even in the state of fitting with the fitting recess 25. Therefore, when the holder 21 is welded to the auger 2, the reinforcing material can be passed between the side surface 24 a and the auger 2 and welded, whereby the holder 21 can be fixed to the auger 2 more firmly than before.

In addition, in the detachable digging blade 20 of this embodiment,
Since the first and second protrusions 36 and 39 are formed on the cutter bit 22 and are engaged with the groove 29 and the notch 30 of the holder 21, the cutter bit 22 moves in the width direction and the height direction. Is reliably prevented. Further, a bit restraining pin 34 is embedded in the holder base 26 so that the cutter bit 2
2 is fitted in the fitting hole 40 of the cutter bit 2.
The movement of the rear end of the cutter bit 22 in the width direction at the rear end is more reliably prevented, and the rigidity of the cutter bit 22 attached to the holder 21 is increased. Moreover, since the bit restraining pin 34 has a configuration in which a plurality of spring pins 34a to 34c are coaxially combined, the allowable shear force is larger than when a single spring pin is used, and the mounting strength is further improved. I can make it.

In this embodiment, fitting portions such as the groove 29 and the first protrusion 36 are provided in addition to the fitting projection 24 and the fitting recess 25. If the cutter bit 22 can sufficiently prevent the floating movement of the cutter bit 22 with respect to the holder 21 by using only the concave portion 25, these may be omitted. In this embodiment, the bit restraining pin 34 is provided to prevent the rearward movement of the cutter bit 22. However, the present invention is not limited to this. For example, as shown in FIG. Even if the inclined surface 42 is provided, the floating of the cutter bit 22 can be prevented.

By the way, in the detachable excavating blade 20 shown in the above embodiment, the bolt 11a connecting the holder 21 and the cutter bit 22 is screwed with the nut 11b which is in close contact with the side surface 24a of the holder 21. As shown in FIG. 10, when the holder 21 is attached so that the side surface 24a faces the tip side of the auger 2, the excavation surface F excavated by the blade portion 23 is formed.
And the nut 11b are extremely close to each other.
b may be damaged and the nut 11b and the bolt 11a may adhere. Then, under such circumstances, the cutter bit 22
Need to be replaced, it is necessary to cut the nut 11b by gas and remove the bolt 11a.

However, when gas cutting is performed, the side surface 24a of the holder 21 is melted by the heat at the time of cutting and the holder 2 is cut.
1 is likely to be damaged. Therefore, in the detachable digging blade 20, as shown in FIGS. 10 to 13, a concave portion 50 is formed in the side surface 24 a of the holder 21, and a stainless steel reinforcing plate 51 is attached to the concave portion 50 so as to be in close contact with the nut 11 b. Good to let. According to the reinforcing plate 51 made of stainless steel, there is no possibility of melting by the heat at the time of gas cutting.
This is because it is possible to prevent damage to the device 1 and reliably use it. In addition, as a method of attaching the reinforcing plate 51, the nut 11
b, the reinforcing plate 51 may be tightened and held, or the reinforcing plate 51 may be welded to the holder 21.

[0026]

As described above, according to the present invention, the side of the fitting projection of the holder facing outward in the width direction is exposed to the outside of the detachable digging blade. When mounting, not only the rear end of the holder,
Reinforcing material is also welded to the side of the fitting projection that faces outward in the width direction, so that the holder mounting strength can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a view as seen from an arrow II in FIG. 1;

FIG. 3 is a view as seen from the direction of arrow III in FIG. 1;

FIG. 4 is a view as viewed from an arrow IV in FIG. 2;

FIG. 5 is an enlarged view of a portion C in FIG. 4;

FIG. 6 is a plan view of the cutter bit shown by a two-dot chain line in FIG.

FIG. 7 is a view as seen from the direction of the arrow VII in FIG. 6;

FIG. 8 is a view as seen from the direction of arrow VIII in FIG. 6;

FIG. 9 is a plan view showing another example of the present invention.

FIG. 10 is a view showing a state in which the detachable excavation blade shown in FIG. 1 is attached to an outer peripheral portion of the auger.

11 is a side view of the detachable digging blade shown in FIG.

FIG. 12 is a view as seen from the XII direction in FIG. 11;

FIG. 13 is a view as seen from the direction of the arrow XIII in FIG. 11;

FIG. 14 is a view showing a conventional detachable digging blade, and FIG.
Is a side view, and FIG. 2B is a plan view.

FIG. 15 is a view showing an auger in a state where a detachable digging blade is attached.

[Explanation of symbols]

 2 Earth Auger (Drilling Head) 20 Detachable Drilling Blade 21 Holder 22 Cutter Bit 23 Blade 24 Fitting 25 Fitting

Claims (1)

(57) [Scope of request for utility model registration] 1. A cutting tool comprising: a holder having a rear end attached to an excavating head of an excavator; and a cutter bit having a cutting edge provided on a front end side, wherein a rear end of the cutter bit is provided from a rear end surface of the cutter bit. A fitting concave portion that is depressed toward the distal end is formed, and a fitting convex portion that enters the fitting concave portion of the cutter bit and is in close contact with the wall surface of the fitting concave portion is formed at the distal end portion of the holder. In the detachable digging blade, the fitting protrusion of the holder is formed along one edge in the width direction of the holder, and a side surface of the fitting protrusion which faces outward in the holder width direction is formed by the cutter bit. A detachable digging blade, which is exposed to the outside from a fitting recess.