JP2735296B2 - Centrifugal impact crusher - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a centrifugal impact crusher for impact crushing rocks, ores, etc., and more particularly, to a collision plate having a long life and suppressed early wear. The present invention relates to a centrifugal impact crusher provided.

(Prior art)

As shown in FIG. 6, the centrifugal impact crusher 1 has a vertical shaft 15 provided inside the main body casing 2.
The rotor chamber 3 fixed at a high speed rotates in the arrow K direction. A discharge port 5 is formed in the peripheral wall of the rotor chamber 3, and rocks 4 are ejected from the discharge port 5 by centrifugal force.
A collision plate 6 having a collision surface portion 7 against which the rock 4 collides is provided in the main body casing 2 around the rotor chamber 3. The collision surface 7 is arranged at an appropriate distance from the rotor chamber 3 perpendicular to a tangent line from the rotor chamber 3, that is, a projection line of the rock 4.

Accordingly, the rock 4 in the rotor chamber 3 is first discharged from the discharge port 5 and then crushed by colliding with the collision surface 7 of the collision plate 6 located on the projection line.

Thus, the collision plate 6 used under severe conditions is
A chromium-based metal material with relatively high wear resistance is widely used as its material, and a cemented carbide chip made of cemented carbide is mounted on a mounting base that is detachably fixed over the entire impact surface of the impact plate. Measures have been taken to reduce wear due to rock impact by joining by silver brazing.

[Problems to be solved by the invention]

However, in the centrifugal impact crusher 1 as described above,
When joining the cemented carbide tip and the mounting base, inevitable thermal stress remains due to the difference in the coefficient of thermal expansion between the two. When an impact force due to a rock collision is applied thereon, the carbide tip may be damaged.

Further, since the cemented carbide used for the cemented carbide tip is originally a brittle material, the larger the cemented carbide tip, the more likely it is to crack.

Therefore, in order to prevent these, it is necessary to appropriately determine the shapes and sizes of the cemented carbide tip and the mounting table, and to select a brazing material having less thermal distortion.

On the other hand, the thrown out rock 4 sometimes collides with the outer peripheral side of the collision surface where the mounting base is fixedly attached, and wears the outer peripheral side.

For this reason, even if the cemented carbide chip mainly subjected to the collision of the rock 4 has a long life, the cemented carbide chip disposed on the outermost side of the collision surface may fall off from the collision surface together with its mounts. is there.

Such a cemented carbide tip is uneconomical, because if one part is broken or dropped, the corresponding collision plate must be replaced even if the other part is good.

Accordingly, an object of the present invention is to extend the life of the entire collision plate by preventing chipping, cracking, or early wear of the carbide tip and the collision surface portion.

[Means for solving the problem]

In order to achieve the above object, the main means adopted by the present invention is a rotor chamber that rotates around the axis of a vertical axis provided in a casing, and is disposed at an appropriate distance around the rotor chamber. A centrifugal impact crusher for crushing the object to be crushed ejected from the rotor chamber against the collision plate by crushing the object to be crushed, wherein , A Rockwell A hardness of 85 or more, a bending strength
A centrifugal gist has a point that a wear-resistant material of 60 kgf / mm ² or more is fixedly provided and a point that a coating or a projection having a higher hardness than the cemented carbide tip is formed on the collision surface of the cemented carbide tip. It is a type impact crusher.

[Operation] According to the present invention, in the first invention, a Rockwell A hardness of 85 or more and a bending strength of 60 are provided on the outer peripheral side of the collision surface of the collision plate.
Since the wear-resistant material of kg · f / mm ² or more is fixed, the outer peripheral side portion does not wear due to the impact of the rock.

Thereby, the cemented carbide tips fixed near the outer peripheral side portion do not fall off.

In the second aspect, since a coating or a projection having a higher hardness than the cemented carbide tip is formed on the collision surface of the cemented carbide tip, wear of the cemented carbide tip itself is reduced. As a result, the life of the entire collision plate can be extended.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. Here first
FIG. 1A is a plan view of a collision plate provided in a centrifugal impact crusher according to one embodiment of the first invention, FIG. 2B is a front view of the collision plate, and FIG. FIG. 2 is a front view of a cemented carbide tip according to one embodiment of the second invention, and FIG. 3 is a diagram showing a relationship between a material of a projection formed on the cemented carbide tip and a maximum wear amount. FIG. 4 is a graph showing the relationship between the thickness of the coating layer formed on the cemented carbide tip and the wear amount of the cemented carbide tip according to another embodiment of the second invention, and FIG. It is a table | surface which shows the crack probability according to the shape dimension of a chip.

In the following description, the same elements as those of the centrifugal impact crusher 1 shown in FIG. 6 are denoted by the same reference numerals, and the description thereof will be omitted.

Further, the following embodiments are merely examples embodying the present invention, and do not limit the technical scope of the present invention.

In this embodiment, the impact plate 6 _a to be provided to the centrifugal impact crusher 1, as shown in FIG. 1 (a) to FIG. (C), the collision surface is a front square shaped impingement plate preform On the surface of the rotor chamber 3 on the side of 10, a square block-shaped mounting base 9 is screwed in a grid. The mounting base 9 has a cross-shaped groove formed on the joint surface with the collision surface portion 10 and is fitted removably with a lattice-like projection formed on the collision surface portion 10. Further, a cemented carbide tip 8 is joined to the surface of the mounting base 9 on the rock collision side by silver brazing.

Reinforcing members 16 made of silicon nitride as a wear-resistant material are fixed to the four outer peripheral side portions of the collision surface portion 10 with an adhesive. Such impingement plate 6 _a, as the impact surface 7 _a of the hard tip 8 which receives the collision of rock 4 is orthogonal to the dispensing line of rock 4, at a suitable distance around the rotor chamber 3 body It is fixed to the casing 2 via an attachment member 12.

Thus, the impingement plate 6 _a is constructed as mentioned above, receipt of an impact rock 4 thrown out from the rotor chamber 3, carbide inserts 8 are gradually worn, the reinforcing member 16 hardly worn. Thereby, the collision surface portion 10 supporting the mounting table 9 is not damaged. Therefore, the carbide tip 8
Does not fall off from the collision surface portion 10 of the mounts 9.

The reinforcing member 16 may be made of any material having physical properties such as a Rockwell A hardness of 85 or more and a bending strength of 60 kg · f / mm ² or more, such as the above-mentioned nitrogen silicon. For example, zirconia, alumina, silicon carbide, etc. Ceramic may be used. That is, a reinforcing member using a material having a bending strength of less than 60 kg · f / mm ² was broken by a continuous impact crushing test for three months, and any reinforcing member of any material was cracked.
If it was less than 85, the progress of the initial wear was remarkable, and it was not usable.

Subsequently, in one embodiment of the second invention, a cemented carbide tip
8 _a, the hard tip 8 _a projection further having a high hardness columnar than 17 is embedded joined to the collision surface 7 _a. The protrusion
17 is satisfactory if it is disposed over the impact surface 7 _a whole surface, if satisfying predetermined conditions, as in the present embodiment, need only be arranged in a row in the vicinity of the outer periphery of the impact surface 7 _a .

That is, one side of the hard tip 8 _a is L, and the thickness is T, the diameter of the protrusion 17 D ^phi (D one side in the case of prismatic)
And the thickness is t. Further, the collision surface of the projection 17
Arrangement on 7 _a is within the distance l from each side of the impact surface 7 _a, the gap between the projections 17 comrades when the d, may be satisfied with all of the following conditional expressions.

D <L (1) d <t (2) (L−2l) / D ^φ ≧ 9 (3) (L−2l) / d ≧ 9 (4) 0 ≦ l ≦ d (5) This is as a matter of course the formula (1), the formula hard tip 8 _a when not satisfied (2) cause initial damage, or the formula (3) satisfies Although equations (4) and (5) Is not satisfied, _a test result that a long life of the carbide tip 8a cannot be expected is obtained.

For example, FIG. 3 shows the results of a continuous impact crushing test for three months using various materials of the projections 17. The conditions at this time are as _follows: the collision surface 7 of the carbide tip 8a having a side L of 48 mm and a thickness T of 15 mm.
_a , at _{a position} where the distance l from each side is 4.5 mm, a diameter D ^φ 4 mm
× The protrusions 17 having a thickness of t15 mm are arranged with a gap d of 3 mm.
Further, Rockwell A hardness of hard tip 8 _a is 88.5, the ultra hard tip 8 _a 16 the tested every material of the projections 17, to measure the maximum wear amount of each of the chips, their average The values are shown in the figure.

According to the report, the material harder than carbide inserts 8 _a projection 17
The amount of wear of the impact plate 6 _a can be greatly reduced, in particular the hardness of the material used for the projections 17 by disposing a; is as the effect larger (Rockwell A HRA) becomes large. That is, here, the hardness of the material used for the hard tip 8 _a (HRA) is 88 to 91, the hardness of the material used for the protrusions 17 (HRA) 9
One or more is appropriate.

Next, a collision plate according to another embodiment of the second invention will be described. The impingement plate is made of a hard coating by ceramic spraying of titanium boride (T _i B ₂₎ is made is formed on the incident surface of the carbide tips. The thickness of the hard coating is set to 10 to 1000 μ.

This is because, as shown in FIG. 4, when the film thickness is less than 10 μm, no improvement in wear resistance is observed, and when the film thickness is more than 1000 μm, the rigidity of the hard film decreases, and It is for peeling off from.

Accordingly, the cemented carbide tip sprayed with a ceramic film having an appropriate film thickness as described above has a long life since "chip" due to collision of the rock 4 does not occur in the initial use stage.

In the ceramic spraying described above, for example, titanium carbide (T _i C),
Alumina (Al ₂ O _3), it may be employed titanium nitride (T _i N) and the like. The number of film layers is not limited to one, and may be two or more. Further, the above-mentioned respective coating materials may be used in combination. Further, instead of the ceramic spraying, a coating may be formed by coating using the respective coating materials.

Previously, the ultra hard to impact surface 7 _a of the hard tip 8, 8 _a chip
By forming the harder projection 17 or the hard coating than 8, 8 _a, but the do attempted to extend the life of the carbide inserts 8, 8 _a, shape and physical properties of the hard tip 8, 8 _a itself The following describes an example in which the abrasion resistance is improved by setting the value appropriately, which leads to the extension of the service life.

Such a cemented carbide tip has a hardness (HRA) of 85 or more and a bending strength of 80 kg · f / mm ² .
Assuming that one side is L and the thickness is T, L / T ≦ 5 (6) T ≦ 8 (7) It is set so as to simultaneously satisfy the equations (6) and (7). As a result, as shown in FIG. 5, the cemented carbide tip satisfying the above conditions was subjected to a three-month continuous impact crushing test without cracking or chipping, and exhibited abrasion resistance and impact resistance. Excellent results.

In each of the collision crushing tests described above, the peripheral speed of the rotor chamber 3 was 60 m / sec, and the rock 4 introduced into the rotor chamber 3 had a maximum particle size of 40 mm.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention, the rotor chamber which rotates around the axis of a vertical axis provided in the casing, and is disposed at an appropriate distance around the rotor chamber, and the carbide tip can be attached to and detached from the collision surface portion And a collision plate fixed to the rotor plate. The centrifugal impact crusher crushes the object to be crushed projected from the rotor chamber by colliding with the collision plate, and locks the outer peripheral side portion with the collision surface portion. A centrifugal impact crusher wherein a wear-resistant material having a well A hardness of 85 or more and a bending strength of 60 kg · f / mm ² or more is fixed, Since the centrifugal impact crusher is characterized by forming a high hardness film or projection, chipping, cracking, or early wear of the carbide tip and the impact surface can be reduced. Thereby, the life of the entire collision plate can be extended.

[Brief description of the drawings]

1A is a plan view of a collision plate provided in a centrifugal impact crusher according to one embodiment of the first invention, FIG. 1B is a front view of the collision plate, and FIG. FIG. 2 is a side view of the collision plate, FIG. 2 is a front view of a cemented carbide tip according to one embodiment of the second invention, and FIG. 3 is a graph showing the relationship between the material of a projection formed on the cemented carbide tip and the maximum wear amount. FIG. 4 is a graph showing the relationship, FIG. 4 is a graph showing the relationship between the thickness of the coating layer formed on the cemented carbide tip according to another embodiment of the second invention and the wear amount of the cemented carbide tip, and FIG. FIG. 6 is a perspective view of a conventional centrifugal impact crusher as an example of the background of the present invention. [Explanation of Signs] 1... Centrifugal impact crusher 2... Body casing 3... Rotor chamber 4... Rock (crushed object) 6,6 _a ... Impact plate 7,7 _a . 8 _a Carbide tip 10 Collision surface 15 Vertical axis 16 Reinforcement member (abrasion resistant material) 17 Projection

Claims (2)

(57) [Claims] 1. A rotor chamber provided in a casing and rotating around an axis of a vertical shaft, and disposed at an appropriate distance around the rotor chamber so that a carbide tip can be detachably attached to a collision surface portion. A centrifugal impact crusher for crushing the object to be crushed projected from the rotor chamber against the collision plate, wherein a rock well is provided on an outer peripheral side of the collision surface portion. A hardness 85 or more,
A centrifugal impact crusher characterized by having an abrasion-resistant material with a bending strength of 60 kg · f / mm ² or more fixed. 2. The centrifugal impact crusher according to claim 1, wherein a coating or a projection having a higher hardness than that of the cemented carbide tip is formed on a collision surface of the cemented carbide tip.