JPS6160235B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mining bit for the mining industry, and more particularly to a longwall mining bit used for cutting coal, potash or trona formations. For mining operations, it consists of a shank for insertion into the tool holder and a front working part on the shank for engaging the material layer. In order to increase the life of the bits for cutting into and cutting out coal or mineral beds, individual inserts of hard wear-resistant material have been provided on the front working part.

In longwall mining bits, the insert is oriented in the direction of rotation of the bit and has a cutting edge on the insert for impacting the mineral formation. A relief surface is provided at the rear of the insert to reduce the friction of the front working part against the mineral layer as the bit passes through the mineral layer.

A plurality of cutters are usually mounted on a drum, and the cutters are typically rotated at 60 revolutions per minute while the drum is driven into and along the coal seam at a speed of about 20 to 40 feet per minute. .

The front working portion of the cutter typically penetrates the coal seam by 2 to 4 inches. As the drum rotates and is moved along the face of the coal seam, the coal seam is removed by cutting, picking and hammering.

Typically, in coal seam longwall mining,
The drum moves along the face of the coal seam, and workers can only access the drum at the end of each movement.

As the cutter bit is used, wear develops across the front working portion of the bit and extends from the front cutting edge of the insert rearwardly across the flank. Reduced relief increases friction and wear of the front working part against the coal seam and generates excessive heat, often causing insert failure due to thermal cracking. The development of wear scars across the flank of the bit increases the power consumption of the machine and sometimes causes the machine to stop.

The cutting edge of the insert on the cutter bit is oriented in the direction of rotation of the bit, and when viewed from the front, the cutting edge tapers outwardly towards the shank and is preferably V-shaped or U-shaped, with the cutting edge being V- or U-shaped. It opens towards the shank. It is desirable to retain this configuration over the life of the bit, rather than allowing the cutting edge to wear flat. As the cutting edge wears flat, not only more power is required, but also more dust is often generated in the mine.

One object of this invention is to provide a cutter bit that is more durable than conventional mining bits.

Another object of this invention is to increase the life of the cutter bit by reducing the heat generated by the friction of the flank against the coal seam.

Yet another object of the invention is to increase the life of the cutter bit by controlling flank wear to provide self-sharpening cutter bits.

Still another object of the invention is to make the life of the cutter bit more predictable and to allow the bit to be replaced at the easily accessible end of the cutter drum's travel.

The present invention includes a cutter bit having a shank for insertion into a tool holder and a front working part having a bulk insert, at least a cutting lead insert having a cutting edge for removing hard and abrasive mineral layers. .

The insert is constructed of a hard, wear-resistant material such as cemented carbide, and the lead insert is mounted on the front working portion of the bit and projects in a predetermined direction of travel of the bit.

A relief surface is placed behind the hard wear resistant lead insert to reduce wear on the mineral layer being removed.

In accordance with the invention, the lead insert is a single carbide insert or a laminated insert having at least two individual inserts joined to the cutter body.

Further in accordance with the invention, an additional insert is mounted in the rear flank of the insert and has a cutting edge thereon. The high volume insert reduces wear on the front working section behind the lead insert and increases the life of the bit by maintaining the taper on the front working section of the bit.

The benefit of maintaining a taper on the front section is to create a self-scratching effect and reduce the heat generated by friction of the bit through the coal or mineral bed. This reduces insert failure due to thermal cracking and the wear resistance of the insert is more fully utilized. An additional insert mounted on the flank may project beyond the flank and have its own cutting edge at the beginning of bit life. Additional inserts that control flank wear patterns help reduce lead insert wear and create a self-sharpening effect, which reduces the power required per unit volume of mineral or coal produced.

The additional insert placed in the flank includes forming a recess in the flank behind the lead insert and securing into the recess an insert of hard wear-resistant material projecting above the flank, the insert being The material is preferably a wear-resistant sintered hard metal carbide, but materials such as ceramic, diamond, hardfacing materials, etc. may also be used.

The recess formed in the flank may take the form of a cylindrical hole, a series of cylindrical holes, an elongated slot or a plurality of slots, or an additional insert may be attached to the rear surface in the direction of travel of the lead insert.

Along with possible cutting edges on the additional insert in the flank, the invention further includes a lead insert consisting of at least two inserts, the cutting edges being placed in mutually adjacent relationship, so that one insert cannot fail. If so, the second insert provides its cutting edge to the material to be removed.

A preferred embodiment is to arrange at least two inserts with cutting edges as described above to form a laminated insert on the front working part of the bit, and at least two individual inserts are brazed to the metal shim. . The cutting edges of the individual inserts are arranged to point in the direction of rotation of the bit and are arranged one after the other so that if the leading cutting edge becomes worn or cracked, the trailing cutting edges work against the mineral formation. . The leading cutting edge is preferably thicker and narrower than the trailing cutting edge, thereby providing greater wear resistance in the central portion of the cutting edge.

A preferred embodiment of the invention includes at least one cylindrical insert mounted in the flank, with its uppermost tip projecting above the lead cutting tip and forming an included angle of 6 degrees with a plane perpendicular to the longitudinal axis of the bit. In addition, it must intersect with a line passing through the apex of the cutting edge of the lead insert.

Preferably, each cutting insert is constructed from a sintered metal carbide material and has a metal shim member separating the two inserts.

The carbide insert is brazed to the metal shim member and the entire assembly is brazed into a pocket formed on the front working portion of the cutter.

In a preferred embodiment, the lead insert is constructed from a tough, impact resistant carbide material and the other is constructed from a wear resistant carbide material.

The nature of the invention will become more apparent by reference to the following detailed description taken in conjunction with the accompanying drawings.

Referring to the drawings, Fig. 1 shows Katsutabitsu 1.
0 is shown in a cut-away side view of the bit 10, which has a front working section 1 with a flat rectangular shank section 12 and an oblique or curved clearance surface 24.
4. A cutting insert 16 is mounted on the front working part 14, and a cutting edge 18 is formed on the insert 16. The insert 16 is typically constructed of a hard wear resistant material, such as a sintered hard metal carbide material, and is brazed into a pocket 20 formed on the front working portion 14.

The direction of movement of the bit 10 is indicated by the arrow 22, and the bit 1 is driven against the layer to be crushed.
A front working part 14 is located behind the cutting blade 18 in the direction of movement.
The escape route 24 is located.

The relief surface 24 is shaped to reduce friction on the rearmost portion of the front working portion 14 of the cutter bit 10 as the cutter bit 10 is driven through the mineral formation.

In accordance with the invention, a hard wear resistant device 26 is mounted in and projects from the flank 24 and is located behind the hard wear insert 16. Hard wear resistant device 26 is preferably a sintered hard metal carbide material and is positioned adjacent rear surface 28 of insert 16 when installed in place.

FIG. 2 shows more clearly a cut-away side view of the front working part 14 with a hard wear-resistant device 26 arranged in the flank 24. However, individual carbide inserts 30, 32
form a composite or laminated insert, each insert being brazed to a metal shim member 34.
Preferably, the inserts 30, 32 are formed from a sintered hard carbide material and are brazed to the steel shim member 34.

Hard wear resistant device 26 is preferably constructed from a hard wear resistant metal carbide material.

The advantage of composite or laminated inserts is that some materials, such as sintered metal carbides, which are hard and wear resistant, are susceptible to failure due to thermal cracking. By making the lead insert a composite of at least two individual inserts shim-bonded or brazed to each other, the temperatures experienced in each carbide insert are reduced, which reduces the tendency for thermal cracking. Furthermore, in the event that a crack occurs in the individual carbide parts, propagation is prevented by the metal shims or brazed joints separating the two individual inserts 30, 32.

FIG. 3 is a plan view of the cutter of FIG. 2 showing insert 30, shim member 34 and second insert 32. FIG. Elongated slot 36 is configured such that hard wear resistant device 26 is placed into slot 36 and brazed into place.
The hard wear-resistant device 26 is positioned firmly against or adjacent the rearmost portion of the insert 32.

FIG. 4 shows the front working part 14 and the steel shim 3.
Laminated or composite insert 3 brazed to 4
Another cutter bit 40 is shown having a number of 0.32.

In this figure, the wear-resistant device has a cylindrical hole 42
and a cylindrical insert 44 is brazed into the hole. The insert 44 has a rounded outer surface and is also mounted in and projects upwardly from the rear flank surface 24 of the laminated inserts 30,32.

FIG. 4A is a plan view of the cutter of FIG. 4, showing the insert 30 brazed to shim 34,
32 and a hard wear-resistant device 44 located on the rear flank surface 24 of the insert.

FIG. 5 shows another embodiment of a flat cutter according to the invention. Katsutabitsu 50
has a rectangular shank 52 and a front working portion 54 on which inserts 56, 58 are mounted. Inserts 56, 58 are brazed to shim member 60 and form a laminated insert on cutter bit 50. The direction of rotation is still arrow 62
is shown. Immediately behind the inserts 56, 58 is a hard wear-resistant device 64, which is arranged directly behind the insert 58 in the direction of movement of the cutter bit 50.

FIG. 5A is a partial front view of the cutter bit of FIG. 5, showing portions of insert 56, shim member 60, and insert 58. Cutting edges 66 are formed on the inserts 56, 58 and are shaped to taper outwardly toward the shank 52 of the cutter bit 50 and are generally U-shaped or V-shaped when viewed from the front. Of all the inserts mentioned above,
This is the preferred form of the cutting edge when viewed from the front, irrespective of whether a single insert or a laminated insert is arranged in the front working part of the cutter.

Specifically, as shown in FIG. 5, when the inserts 56, 58 are in place on the cutter bit 50, the cutting edges on both inserts are V-shaped, tapering outwardly toward the shank 52. Shaped to form a cutting edge. Hard wear-resistant device 6
4, when placed in the concave slot 67 of the front working part 54, serves to maintain the tapered cutting edge 66 over the life of the cutter bit. It is believed that maintaining a tapered cutting edge provides a more effective or proper cutter bit than previously known bits.
As shown in FIG. 5A, the cutting edge 66 is inserted into the insert 5.
It is narrower than the cutting edge 61 on 8, thereby providing greater wear resistance in the central part of the cutter bit.

6 and 7 show plan views of different embodiments of the multiple insert cutter bit according to the invention.

FIG. 6 shows a plan view of a cutter bit 70, which has a single insert 72 mounted in its front working portion 74;
An elongated wear-resistant device 76 is disposed immediately behind the
It is mounted in a specially shaped slot 78 to hold a hard wear resistant device 76.

FIG. 7 also shows a cutter bit 80 having a single insert 82 mounted on the front working portion 84 of the bit. In this case, a cylindrical hard wear-resistant device 86 is mounted in a cylindrical bore 88 behind the insert 82 from the direction of movement of the bit 80.

FIG. 8 shows a front working portion 90 of a further embodiment of a multi-insert cutter bit according to the invention.
It is shown.

8 and 9 show the lead insert 92 installed in front of the second insert 94, each of the inserts having a flank 9 of the cutter bit 100.
Each shim member 96 attached to the front part of 8 is brazed. Immediately behind insert 94 is 2
Two cylindrical inserts 102, 104 are arranged which protrude from the flank and form a hard wear resistant device which serves to maintain the tapered cutting edge 106 on the cutter bit 100 as previously described.

Details of the structure of FIG. 7 are shown in FIG. 10, and a modification of such a bit is shown in FIG.

In FIG. 10, bit 105 is block 10.
6 and has a forward-most carbide compact 108 and a second carbide powder compact 110 positioned behind the forward-facing feature 108 .

The molded body 110 has a substantially cylindrical shape, and a carrier portion 111 is disposed on the front side of the molded body, and a cutting blade 11 is provided on the molded body.
2 is starting to form. The cutting edge 112 is located approximately on a 4-6 degree line drawn along the back rake of the bit 105. This angle is determined by constructing a plane perpendicular to the longitudinal axis of the bit shank and passing it through the apex of the cutting edge of the lead insert.

Testing of these bits has shown that the flank wears approximately on a 4-6 degree line when compared to a horizontal line parallel to the base block 106 into which the bit 105 is inserted. Therefore, the cutting edge of the rear insert 110 should be placed on a line approximately 4 to 6 degrees from the flank surface, so that the insert 1
10 has a cutting action similar to that of the front molded body 108 and prevents wear along the flank surface.
The illustrated conformal angle preferably varies from 4 degrees to 6 degrees, but may vary depending to a large extent on the feed of the cutting drum along the face of the coal to be cut.
For many feeds, 4 to 6 degrees has been found to be suitable, but the farther the drum feed is along the coal face, the larger the angle must be to achieve optimal cutting. Dew.

Another modified bit 120 is shown in FIG.
2. This bit has a lead insert 124, a second cylindrical insert 126 as shown in FIG.
126 each has a flat portion formed thereon;
Cutting edges 112, 128 are adapted to be provided on the insert.

Again, as shown, it is considered desirable for all inserts to perform the cutting action simultaneously during use, so the inserts 110, 126 have their cutting edges 112, 128 aligned with the flank of the bit 120. It is arranged on a line inclined by 4 to 6 degrees.

Figures 10A and 11A show plan views of Figures 10 and 11, respectively. In FIG. 10A, front insert 108 is shown with a cylindrical insert 110 having a cutting edge 112. In FIG. Similarly,
In FIG. 11A, an insert 110 with a cutting edge 112 and an insert 1 with a cutting edge 128 are shown.
10 with a rear insert 126 is shown. Again, it is desirable to place the entire cutting edge near or above the 6 degree line from the horizontal 125.

FIG. 12 shows another variant in which a third insert 126 is shown in its position.
However, insert 127 is shown as a cylindrical plug, tapered from top to bottom in side view and inserted into hole 129 and brazed in place with solder 131.

By locating the insert 127 in the bit in this manner, it is believed that the insert itself will have a self-sharpening effect as it wears. In other words, a new cutting edge is always provided for the tapered portion or the finished material to be cut.

FIG. 13 shows an insert 1 shown in end view as a cylindrical plug and tapered from one end to the other.
31 is shown.

FIG. 13A shows a side view of an insert 131 that tapers from one end to the other.

As shown in FIG. 11, the 6 degree included angle is constructed by forming a plane perpendicular to the longitudinal axis of the shaft of the bit 120 and passing this plane through the top tip of the forward cutting insert 124. sell.

The 6 degree line shown in FIG. 11 then intersects the plane and has cutting points 112, 128 that coincide with or approximate the 6 degree angle.

Many modifications may be made within the scope of the claims.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view of the cutter bit according to the present invention. FIG. 2 is a partially cutaway side view of the Katsutabit according to the present invention. FIG. 3 is a plan view of the cutter bit according to the present invention. FIG. 4 is a side view of one embodiment of the multi-insert cutter bit according to the present invention. FIG. 4A is a partial plan view of the cutter of FIG. 4; Fifth
The figure is a side view of another embodiment of the multi-insert cutter bit of the present invention. FIG. 5A is a partial front view of the cutter of FIG. 5. FIG. 6 and 7 are plan views of different embodiments of the multi-insert cutter bit according to the present invention. FIG. 8 is another side view of the cutter bit according to the present invention. Figure 9 is the 8th
FIG. FIG. 10 is a side view of a bit of the type shown in FIG. 1st
0A is a plan view of FIG. 10. FIG. 11 is a side view of a modified bit of the type shown in FIG. FIG. 11A is a plan view of FIG. 11. 1st
FIG. 2 is a side view of yet another modified form of the bit according to the present invention. FIG. 13 is an end view of the cutting insert according to the present invention. FIG. 13A is a side view of the cutting insert according to the present invention. 10... Katsutabitsu, 12... Shank part, 14... Working part, 16... Cutting insert, 18... Cutting blade, 20... Pocket, 24...
Flank surface, 26... Wear-resistant device, 30, 32...
Insert, 34...Shim member, 36...Slot, 40...Katsuta bit, 42...Insert, 50...Katsuta bit, 52...Shank,
54... Working part, 56, 58... Insert,
60...Shim member, 64...Abrasion resistant device, 66
... Cutting blade, 67 ... Slot, 70 ... Cutting bit, 72 ... Insert, 74 ... Working part,
76...Abrasion resistant device, 78...Slot, 80
...Katsutabitsuto, 82...Insert, 94...
...Working part, 86... Wear-resistant device, 88...
Hole, 90... Working part, 92... Lead insert, 94... Insert, 96... Shim member, 9
8...Fleeing surface, 100...Katsutabitsuto, 10
2,104...Insert, 106...Cutting blade, 1
08,110... Carbide molded body, 112... Cutting blade, 120... Bit, 122... Holder, 12
4... Lead insert, 110, 126... Insert, 112, 128... Cutting blade.

Claims (1)

Claims: 1. A shank device and an abutment device for insertion into a tool holder, and a front working part on the shank device for engaging the material to be cut;
a first cutting edge having a side tapering outwardly toward the shank device when viewed from the front;
A cutter bit having a hard wear-resistant device on the front working part and a clearance surface behind the cutting edge, wherein an insert of hard wear-resistant material is installed in the flank surface behind the hard wear-resistant device. , the insert has an end portion projecting above the flank surface;
The cutter bit is characterized in that the wear rate of the first cutting edge is thereby reduced and its taper is maintained throughout the life of the bit. 2. Claims in which the insert mounting comprises an elongated slot extending rearwardly from the direction of rotation of the bit and located rearwardly of the hard wear-resistant device, and an elongated insert mounted in the slot. Katsutabitsu as described in Section 1. 3. The Katsutabi according to claim 2, wherein the hard wear-resistant material comprises a sintered hard metal carbide. 4. The hard wear-resistant device forming the cutting edge comprises at least two separate wear-resistant inserts and a device for holding the inserts together, each of the inserts having a diameter of about 10 mm when viewed from the front. A cutter bit according to claim 1, having a cutting edge that tapers outward toward the shank device. 5. The cutter bit of claim 4, wherein the device for holding the inserts together comprises a shim member between the two inserts and a device for securing the insert to the shim member. 6. The method of claim 1, wherein mounting the insert comprises forming a first cylindrical recess in the flank and mounting an elongated cylindrical insert of hard wear-resistant material into the recess. Katsutabitsuto. 7. Claim 7 further comprising: a second cylindrical recess formed in the flank behind the first cylindrical recess; and a second elongated cylindrical insert mounted in the second recess. Katsutabitsu as described in Scope No. 6. 8 The cutting edge of the first separated insert forming the hard wear resistant device is lower than the cutting edge of the second separated insert forming the hard wear resistant device when the two separate inserts are viewed from the front. Katsutabitsu according to claim 4, which has a narrower scope. 9. The cutter bit of claim 1 further comprising a cutting edge formed on the end portion of the insert and projecting from the flank. a first plane formed perpendicular to the longitudinal axis of the shank of 10 bits and forming an included angle of 2 to 10 degrees with a second plane passing through the tip of the hard wear-resistant device on the front working part; 10. The cutter bit of claim 9 further comprising a portion of the cutting edge of the second insert disposed through or adjacent to the cutting edge. 11. The Katsudabit according to claim 10, wherein the first plane and the second plane form an included angle of 4 to 6 degrees. 12 comprising at least two inserts mounted in the flank, each of the two inserts having a cutting edge and a tip of each of the cutting edges being in or adjacent to the first plane; The cutter bit according to claim 11, wherein the cutter bit is arranged as described in claim 11. 13. The cutter bit of claim 9, wherein the insert in the flank comprises an elongated cylindrical plug member. 14. Claim 1, wherein the plug member has a flat portion formed thereon, and the flat portion intersects with one end of the plug member to form a cutting edge.
Katsutabitsu described in item 3. 15. The cutter bit according to claim 14, wherein the flat surface of the flat portion tapers away from the center line of the plug member as it moves away from the cutting edge.