JPH0675687B2 - Impactor for impact crusher - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a striker for an impact type crusher that impact crushes rocks, ores, etc., and particularly to a cemented carbide material piece provided in the impact part. The present invention relates to a striker for an impact type crusher capable of reducing cracks and cracks.

[Prior Art] A conventional impact type crusher is configured as shown in a schematic side sectional view in FIG.

For example, the rough stone put into the crushing chamber 3 through the raw material supply port 2 installed above the side of the impact crusher 1 is a striker fixed to the outer periphery of the rotary rotor 5 rotating around the main shaft 4. Impact crushed by 6.

The rough stone hit by the rotating rotor 5 is crushed by colliding with the liner 7a attached to the first repulsion plate 7 provided at the upper part of the crushing chamber 3, and the rough stone returning is further rotated. The next striker 6 crushes the striker. Then, the bounced rough stones are liner 8a attached to the second repulsion plate 8 provided in the upper portion of the crushing chamber 3.
Is crushed into smaller pieces.

In the case of the conventional impact type crusher 1 as described above, the impactor 6 formed as an integral body is generally made of high chromium cast iron, or
Hard metal materials such as high manganese cast steel and chrome molybdenum cast steel are used.

However, in such a hitting element 6, since the hard mineral is also contained on the side of the raw ore to be crushed, the impact with the hard raw ore is repeated, as shown in FIG. As described above, the wear gradually occurs.

That is, as shown in FIG. 7 (a), the tip portion 6a of the striker 6 whose initial shape is shown by the solid line is gradually changed as shown by a plurality of broken lines in FIG. 7 (b). It wears out and transforms into a rounded shape.

In the conventional impact type crusher 1, from the viewpoint that it is uneconomical to discard the hitting element 6 in this state, the hitting element 6 is turned upside down as shown in FIG. Continue to use until wear progresses as shown by the broken line in FIG.

[Problems to be Solved by the Invention]

Thus, in the conventional impact type crusher 1, the impact element 6 is
Since the wear resistance of No. 1 was not sufficient, if the impactor 6 wears and the tip 6a becomes rounded, it becomes difficult for the object to be crushed to collide head-on, and the crushing ability deteriorates. There was a drawback that the cost increase would be large.

Further, the frequency of replacement of the hitting element 6 including the reversal of the hitting element 6 is extremely frequent, for example, once every 1.5 to 3 months in the crushing of rocks for aggregates. It was extremely harsh and had the problem of impeding operational efficiency.

In order to reduce the wear of such a hitting element, a hitting element having a hard cemented carbide material attached to the tip of the hitting element has also been developed. Becomes brittle as the hardness increases, and chips and cracks easily occur due to collision with the raw material. Further, there is a problem in that the super hard material is expensive, so that it is not economically attractive.

Therefore, an object of the present invention is to provide a striker for an impact type crusher that has excellent wear resistance and can withstand continuous use for a long time.

[Means for Solving the Problems]

In order to achieve the above object, the main means adopted by the present invention is, as its gist, a rotating rotor that rotates around a main shaft provided inside a casing, and is fixed to an outer peripheral portion of the rotating rotor. A plurality of impactors and a repulsion plate provided around the rotary rotor at an appropriate distance, and the raw material spattered at the tip of the rotating impactor collides with the tip of the impactor and the repulsion plate. In a striker for an impact-type crusher that is crushed by crushing, a piece of cemented carbide material is brazed to each joining table that is detachably attached to the tip of the striker and is divided into a plurality in the direction of the main axis of the rotating rotor, The cemented carbide material piece has a WC group and a sintered alloy containing Co, Ni or Co + Ni as a main component, and the average particle diameter of the WC group powder.
_Wc and Co, Ni or Co + Ni weight ratio X (percent)
Satisfies _wc ≦ −0.45X + 13.5, and the thickness dimension T (mm) and hardness HRA of the cemented carbide material piece are T ≧ 4 (85 ≦ HRA ≦
90.5), T> 7 (90.5 <HRA <93).

〔Example〕

Embodiments embodying the present invention will be described below with reference to the accompanying drawings to provide an understanding of the present invention. The following examples are merely examples embodying the present invention and are not of the nature to limit the technical scope of the present invention.

Here, FIG. 1 shows a main part of a striker for an impact type crusher according to an embodiment of the present invention. FIG. 1 (a) is a front view, FIG. 1 (b) is a side view, FIG. 2 is a side sectional view of the impact type crusher with the above-mentioned impactor attached, and FIG. 3 shows the hardness of the cemented carbide piece attached to the above-mentioned impactor on the initial damage within 10 hours of use. Fig. 4 is a graph showing the influence of the thickness dimension, Fig. 4 is a graph showing the relation between the average particle size _wc of the WC-based powder that constitutes the above-mentioned cemented carbide material piece and the weight ratio X of Co, Ni or Co + Ni, and Fig. 5 is the above. It is a graph which shows the relationship between the thickness dimension T of a superhard material piece, and hardness HRA.

Further, the same symbols are used for the elements common to the conventional impact type crusher 1 shown in FIG. 6, and the description thereof will be omitted.

In the impact type crusher striker according to this embodiment, as shown in FIGS. 1 (a), 1 (b) and 2, a plurality of impact crushers are provided in the direction of the main shaft 4 of the rotary rotor 5 of the impact type crusher 1 '. The divided joining base 9 is detachably attached to the tip of the striker 6 '. In this case, the spigot portion 9 _a of the joining base 9 is fitted to the spigot portion formed at the tip of the striker 6 'is mounted by the non-illustrated bolts.

Then, the cemented carbide tip 10 (piece of cemented carbide material) is fixed to the surface of each of the joining bases 9 by brazing. The cemented carbide tip 10 is formed in a rectangular parallelepiped shape in a plane,
Each corner portion other than the joining surface with respect to the joining table 9 is formed into a curved surface (for example, curvature 4R).

The cemented carbide tip 10 is composed of a WC-based sintered alloy whose main component is a material consisting of Co, Ni or Co + Ni, and the WC-based powder average particle diameter _wc and the weight ratio X of Co, Ni or Co + Ni. (Percent) is configured to satisfy the condition that _wc ≤-0.45X + 13.5.

In this case, TiC, T _a C, VC, C _r3 , C ₂ , H _f C, N _b C
Alternatively, one or two or more kinds of carbide having a strong affinity for C such as Mo ₂ C may be added at a ratio of 0 to 5% to improve the performance.

It should be noted that the ratio of the additives such as TiC is limited to 5% or less because when these additives are added at a ratio of 5% or more,
This is because the toughness of the cemented carbide tip 10 may be significantly impaired and an initial defect may occur.

Further, in terms of shape, the above-mentioned cemented carbide tip 10 is
The thickness T (mm) and the hardness HRA satisfy the relation of T ≧ 4 (85 ≦ HRA ≦ 90.5) ... T> 7 (90.5 <HRA <93).

Next, the details of how the conditions such as the above and the formula are derived will be described in detail below.

As described above, when the cemented carbide tip 10 is attached to the striker 6'of the impact type crusher 1'and used, the following two points are important.

The cemented carbide that forms the cemented carbide tip 10 has a tougher than conventional metal-based wear resistant materials such as high chromium cast iron.
Since it is inferior in impact resistance, it is necessary to form an alloy component excellent in these characteristics and also to consider the shape in order to overcome the characteristics of the superhard material which is originally more brittle than the metal-based abrasion resistant material.

As described above, the conventional striking element made of a metal-based wear resistant material has a relatively low replacement frequency because of its insufficient wear resistance. Therefore, the crushing plant is constructed together with the impact type crusher as described above, and for example, the frequency of replacement of the hitting element 6'can be changed once a year by balancing with the frequency of replacement of wear parts of the crusher such as a jaw crusher. In other words, in other words, it is necessary that the cemented carbide used for the cemented carbide tip 10 has a life of about three times or more as long as that of the metal-based wear resistant material.

From the above-mentioned viewpoint, a crushing test was carried out by an impact crusher 1 ′ equipped with a hitting element 6 ′ brazed with various carbide tips.

As shown in FIG. 1 (b), the wear of the above-mentioned carbide tip 10 due to the impact of rough stones progresses from the position of the corner a of the carbide tip 10 to the plate thickness cross section in an arc as shown by the broken line. To go. In the figure, at the initial stage of wear, carbide tips
10 top sides ▲ ▼ and arc Tangent to X ₁ of At the angle θ ₁ determined by and at the stage where the wear has progressed, the side ▲ ▼ of the joining surface of the cemented carbide tip 10 to the joining base 9
Arc Angle θ determined by the tangent ▲▲ ′ at Xi
i is closely related to the defect of the carbide tip 10.

That is, when wear of the cemented carbide tip 10 progresses and the value of the angle θi decreases below a predetermined value, it is found that when the rough stone collides with the tip of the cemented carbide tip 10, the cemented carbide tip 10 is broken. It was

The angle θi is closely related to the thickness dimension T of the cemented carbide tip 10 and the hardness HRA of the WC-based cemented carbide material. In the above test results, the thickness dimension of the cemented carbide tip 10 is given for a predetermined hardness HRA. It has been found that when T becomes equal to or less than a predetermined value, it is destroyed after 10 hours of continuous use.

FIG. 3 shows the effects of the hardness HRA and the thickness T on the initial fracture of the cemented carbide tip 10 in the above test.

Therefore, as is clear from FIG. 3, the carbide tip 10
The relationship between the thickness T (mm) and hardness HRA of T ≧ 4 (85 ≦ HRA ≦ 90.5) ... T> 7 (90.5 <HRA <93) was derived.

The reason why the hardness HRA of the cemented carbide tip 10 is limited to 85 or more is that the cemented carbide having a hardness of 85 or less significantly increases the required minimum thickness dimension T, and This is because the efficiency and economical efficiency of Also, the hardness HRA is 9
The reason for setting a value of less than 3 is, even if the cemented carbide has high toughness such as ultrafine particle cemented carbide, when the hardness becomes 93 or more,
This is because the risk of causing an initial defect is significantly increased.

Next, the examination is performed from the material side of the cemented carbide tip 10 whose shape is limited as described above.

Compared with the metal-based wear-resistant material that constitutes the conventional hitting element, 3
WC-based powder average particle size so that the life can be more than doubled
_wc and Co, Ni or Co + Ni, TiC, T _a C, VC, C _r3 , C ₂ , H
_A crushing test was performed using a cemented carbide tip 10 formed by changing the thickness dimension T to various values together with the blending ratio of each component of _f C, N _b C, and Mo ₂ C. The wear state of each carbide tip 10 was investigated.

The results are shown in Table 1 below.

In this test, the impacting element 6'attached to the rotary rotor 5 had a peripheral speed of 30 m / s, and the rough stone put into the crushing chamber 3 of the impact type crusher 1'was gravel, and its grain Maximum diameter
It was 60 mm.

In Table 1 above, FIG. 4 shows the relationship between the WC-based powder average particle size _{wc of} various carbide tips 10 and the weight ratio X (percentage) of Co, Ni or Co + Ni.

As is clear from FIG. 4, _wc and the weight ratio X of Co, Ni or Co + Ni satisfy the relation of _wc ≦ −0.45X + 13.5 ... And at the same time, the above equation is also satisfied. As a result, it has been found that a hitting element 6'having a dramatically improved wear resistance as compared with a hitting element using a conventional high chromium cast iron and capable of sufficiently withstanding long-term continuous use.

In this case, the value of the WC-based powder average particle size _wc was not too small, and a preferable result was obtained when the value was at least 0.2 μm or more.

When deriving the above formula, the hardness of the WC-based cemented carbide is closely related to the binding metals such as Co and Ni and the WC grain size in terms of composition. Generally, the hardness is uniquely decreased as the proportion of the binder such as Co increases. That is, hardness
It is known that a linear relationship with a negative slope is established between HRA and the amount of bound metal, and this has been proved by many experiments from the past.

Next, when the amount of the binding metal such as Co and Ni is constant, the hardness uniquely increases as the WC grain size decreases. This can be explained by considering cemented carbide as a kind of dispersion hardening type metal.

Here, in order to satisfy the hardness HRA85 or higher required from the viewpoint of life as a cemented carbide material for a striker in terms of composition, it is necessary to consider both parameters of the amount of bond metal and WC grain size.

That is, in order to increase the amount of Co and satisfy HRA85 or higher, it is necessary to reduce the grain size of WC, while when the WC grains are coarse grains, it is necessary to reduce the binding amount of Co and the like. . From such a viewpoint, WC: 0.5 to 10 μm, Co, Co + Ni, Ni content of 7 to 30
Experiments were conducted by changing to wt% (see Table 1), and the same inequality limit line, that is, the above-mentioned formula was derived with HRA85 as a parameter.

FIG. 5 shows the relationship between the thickness dimension T and the hardness HRA of each of the carbide tips 10 shown in Table 1 above.

As is clear from the figure, the thickness dimension T of the carbide tip 10
However, when the hardness HRA is 85 ≦ HRA ≦ 90.5, excellent wear resistance can be obtained even when the relational expression T ≧ −7.2HRA + 650 is satisfied.

In the hitting element 6'according to the above embodiment, in consideration of economy, the larger the hardness HRA of the cemented carbide tip 10 and the smaller the value of the thickness T, the more cost effective. However, when using a carbide tip 10 with high hardness (for example, HRA92 or higher),
There is a high possibility that the cemented carbide tip 10 will be damaged with respect to a crushed object in which rough stones or iron pieces having a diameter of 200 mm or more are mixed.

Therefore, it is most effective to use the hardness HRA in the range of 90 to 91.5.

〔The invention's effect〕

As described above, the present invention is suitable for a rotary rotor that rotates around a main shaft provided inside a casing, a plurality of hitting elements that are fixedly provided on an outer peripheral portion of the rotary rotor, and a periphery of the rotary rotor. In a striker for a shock-type crusher, which comprises a repulsion plate provided at a distance, and crushes the raw material bounced off at the tip of the rotating impactor by colliding with the impactor tip and the repulsion plate. While brazing a cemented carbide material piece to each joining table divided into a plurality of parts in the direction of the main axis of the rotary rotor detachably attached to the tip of the striker, the cemented carbide material piece is a WC base and Co.Ni or It has a sintered alloy containing Co + Ni as the main component, and the WC-based powder has an average particle size _wc.
And Co, Ni or Co + Ni weight ratio X (percent)
_wc ≤ -0.45X + 13.5 is satisfied, and the thickness dimension T (mm) and hardness HRA of the cemented carbide material piece are T ≥ 4 (85 ≤ HRA ≤ 9
0.5), T> 7 (90.5 <HRA <93), because it is a striking element for impact type crusher characterized by satisfying the relationship, it has excellent wear resistance and long-term continuous use. Can withstand enough.

[Brief description of drawings]

FIG. 1 shows a main part of a striker for an impact type crusher according to an embodiment of the present invention. FIG. 1 (a) is a front view, FIG. 1 (b) is a side view, and FIG. Is a side sectional view of the impact type crusher with the above-mentioned impactor attached, and FIG. 3 shows the hardness and thickness of the cemented carbide piece attached to the above-mentioned impactor on the initial damage within 10 hours of use. A graph showing the impact,
Figure 4 shows the average particle size of the WC-based powder that composes the cemented carbide piece.
A graph showing the relationship between _wc and the weight ratio X of Co, Ni or Co + Ni, and Fig. 5 shows the thickness dimension T and hardness of the above cemented carbide material piece.
FIG. 6 is a side sectional view of a conventional impact-type crusher, and FIG. 7 is an explanatory view showing a state of progress of wear of a conventional hitting element. Explanation of numerals] 1 '... impact crusher 3 ...... crushing chamber 4 ...... spindle 5 ... rotating rotor 6' ...... striker 7 ... first rebound plate 7 _a ...... liner 8 ...... second Repulsion plate 8 _a …… Liner 9 …… Joining table 10 …… Cemented carbide tip (carbide piece).

Claims (1)

[Claims] 1. A rotary rotor rotating around a main shaft provided inside a casing, a plurality of hitting elements fixedly mounted on an outer peripheral portion of the rotary rotor, and provided around the rotary rotor at an appropriate distance. A repulsion plate for an impact type crusher, which comprises a repulsion plate and is crushed by colliding the material spattered at the tip of a rotating impactor with the repulsion plate and the repulsion plate. A piece of cemented carbide is brazed to each of the joining bases that are detachably attached to the rotary rotor and is divided into a plurality of joints in the direction of the main axis of the rotor, and the piece of cemented carbide is composed mainly of WC and Co, Ni or Co + Ni. A WC-based powder having an average particle diameter
The weight ratio X (percentage) of _wc and Co, Ni or Co + Ni satisfies _wc ≤ -0.45X + 13.5, and the thickness dimension T (mm) and hardness HRA of the cemented carbide material piece are T ≥ 4 ( 85 ≦ HRA ≦ 90.5) A striking element for an impact type crusher characterized by satisfying the relationship of T> 7 (90.5 <HRA <93).