JPH0730217U - Bucket elevator for conveying foundry sand - Google Patents

Abstract

(57) [Summary] [Purpose] To extend the service life of bucket elevators for the transfer of foundry sand. [Structure] For a given number of buckets 4 attached to the belt 5, the lateral width thereof is larger than that of the other buckets, and
The sweeper bucket 6 in which a highly wear-resistant metal plate 63 is attached to the rake faces of the front upper part 61 and the side upper part 62 of the opening is arranged. [Effect] The foundry sand was deposited on the bottom of the case and hardened, and the rake face of the bucket was abraded intensively. Since the surface of is scraped off so that it does not come into contact with other buckets, the entire service life is greatly extended. Only the worn sweeper bucket can be updated as appropriate.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bucket elevator used for transporting a fluid of solid matter, particularly foundry sand.

[0002]

[Prior art]

 As shown in Fig. 3, the bucket elevator vertically supports two pulleys 2 and 3 (or sprockets) in a vertically oriented box-shaped case 1 and connects either one with a drive source. It is freely rotatable. A belt 5 (or a chain link or the like) is endlessly wound between the both parts, and the belt 5 moves up and down in the case in accordance with the rotation of the pulleys which are engaged with both ends. One side surface of the lower part of the case is cut out to form an input port 11 for receiving a conveyed product, and the other side surface of the case is opened to form a discharge port 12. Other transport means, for example, a belt conveyor C, is connected to the input port and the transport port to deliver the transported product.

The objects to which the bucket elevator is applied are used in a wide range of industrial fields such as construction, civil engineering sites, crushed stone sites, dredging sites, and other factory facilities. It is one of the devices. Therefore, there are a wide variety of goods to be transported, such as earth and sand, grains, and chemical substances. As shown in the figure, the bucket elevator is equipped with a bucket 4 that scoops up the transported material supplied from the input port and moves it to the upper side as it is at intervals such as a belt. The rake face that touches the tip of the opening of the bucket 4 is always in contact with the particles of the transported object and is abraded while the bucket elevator is in use, so it is unavoidable that it gradually wears, but generally it is sand. However, when grains or other particles are in a dry state, they do not adhere to each other and are highly fluid, so there is no great resistance even when scooping, and wear on the rake face is not a serious problem. Once installed, they can usually be used continuously for a considerable period of time.

When the conveyed product is not a dry material having good flowability and is sticky, a considerable obstacle may be encountered in the function of the bucket elevator. In the conventional technique disclosed in Japanese Utility Model Laid-Open No. 62-86327, the material supplied from the inlet to the case and scooped by the rake face of the bucket is lifted to the upper outlet, and the bucket is reversed as the belt rotates. Then, the material scooped inside is discharged toward the discharge port, but not all of the material is discharged at this time, and a part of it often spills and adheres to the inner surface of the case. If some amount of adhered matter in the middle of this process accumulates on its own, it will drop by its own weight and accumulate at the bottom.Therefore, the driving force that raises and lowers the belt momentarily causes an overload, which causes damage to the equipment. .

In this prior art, as a means for solving this problem, as shown in FIG. 4, one or a plurality of buckets 4a attached to a belt 5a have abrasion resistance and flexibility in which tips are extended to a position close to the inner surface of the case. A rubber-made scraping plate 101 having a property of being attached is attached, and when the bucket 4a is moved up and down, the scraping plate is used to scrape off and remove the deposits adhering to the inner surface of the case. It is said that a guide member 102 extending to a position close to the movement locus of the outer opening edge of 4a is attached to prevent the conveyed object from falling when the conveyed object is loaded into and discharged from the bucket elevator.

[0006]

[Problems to be solved by the device]

 It can be certainly evaluated that the structure is modified so that the adhesion to the inner wall surface of the case of the bucket elevator is minimized when handling sticky items. However, this alone is far from a complete solution depending on the type and nature of the transported object. This also applies to the transfer of foundry sand, which is the subject of the present invention. As for molding sand, various additives are mixed with silica sand having a desired particle size as a molding material, well kneaded by a kneader and supplied to the site of the molding process. The compounding amount and amount of foundry sand vary depending on the molding method.For example, bentonite and clay are used as binders with an appropriate amount of water, and self-hardening molds are water glass. In order to enable high-strength molding at the time of molding, highly adhesive components are mixed. Of course, the point of adhesion, which was a problem in the above-mentioned conventional technology, must be taken into consideration, but it should not be overlooked that there is a larger element than that.

Foundry sand is not only sticky when supplied, but also has the property of hardening over time. Because of this property, the strength after molding is high, and even if it encounters molten metal that is injected at high speed, it can maintain its shape until it solidifies.However, in the bucket elevator, bucket wear, especially the rake face of the bucket. Gives a strong wear effect to. Although silica sand itself has a high hardness and a strong abrasion effect, as described above, since it has a high fluidity in a dry state, the resistance is small even when it is scooped, and there is little concern that the abrasion effect due to rubbing will occur early. When deposited and hardened naturally, the sand grains harden while sticking to each other, so the frictional wear due to the inherent high hardness of silica sand directly acts on the contact surface of the bucket.

[0008] The progress of wear is concentrated on the rake face of the bucket, that is, the upper front face and the upper side face near the upper edge of the opening of the bucket. The foundry sand constantly supplied from the inlet is deposited near the bottom of the case and accumulates, and the bucket plunges into this deposit while the opening is tilted downward from the bottom and pivoted while rotating. Since the rake face at the tip of the bucket moves, the sand that is not raked is always left in the arc portion outside the trajectory drawn by the rake face (the hatched portion in Fig. 4 of the prior art), and it hardens with time. Form a hard arc-shaped curved surface. Obviously, the leading edge of the bucket, which always rubs against this surface and passes by, is subject to concentrated wear. The surface of the hardened deposited layer is porous like sponge because it is not compacted like a mold, but it is hard and strong, so the surface is covered with a flexible rubber plate as in the prior art. If it is stroked, the effect of removing it will not appear. In particular, at the bottom portion of the case shown in FIG. 5, since the central portion P is constantly scooped out, the remarkable hardening does not proceed, while the corner portions Q on both sides spill without rake. Since the sand is densified and tends to form a hard and strong layer, the action of abrasion is particularly violent and easy to proceed. FIG. 6 is a perspective view showing the state of the bucket 4a which has lost its function due to this wear, and the corners where the front upper part 41a and the side upper part 42a intersect are missing. Since all the buckets installed in the bucket elevator are affected by this catastrophe, it is necessary to replace all the buckets at an appropriate time, and it becomes impossible to carry the transportation work.

In order to solve the above-mentioned problems, the present invention limits the progress of wear to a local part, and the wear resistance of that part is abnormally high. An object of the present invention is to provide a bucket elevator for transporting foundry sand, which can regenerate a part.

[0010]

[Means for Solving the Problems]

 A casting elevator for conveying foundry sand according to the present invention is a case 1 that is vertically installed and has a carrier inlet 11 on one lower side and a carrier outlet 12 on the opposite side to the upper side. In a bucket elevator consisting of a belt 5 endlessly wound between pulleys 2 and 3 rotatably supported in the upper and lower directions in the case 1 and equipped with a large number of buckets at regular intervals, A sweeper bucket 6 having a lateral width larger than that of the other buckets 4 to the left and right for each number of pieces and having a highly wear-resistant metal plate 63 attached to the casting sand rake face of the front upper part 61 and the side upper part 62 is provided. The above problem was solved by.

[0011]

[Action]

 The cause of the most wear on the rake face of the bucket 4 is the arcuate curved surface drawn by the trajectory of the rake face, but among the many buckets 4 mounted on the bucket elevator belt, the sweeper is swept at a certain rate at regular intervals. Since the sweeper bucket 6 has a larger width than the normal bucket 4, the effect of scraping off the arc surface of the foundry sand that has accumulated and solidified is created. Therefore, the arcuate surface retreats inward from the locus of the rake face of the normal bucket 4 and does not come into contact therewith, so that no abrasion and wear occur at all. Naturally, the rake face of the sweeper bucket 6 that scrapes off the circular arc surface is subject to concentrated wear, but since all of the rake face is attached with a metal plate with high wear resistance, it does not wear as much as a normal bucket 4. However, if it still wears, the original wear resistance and shape can be easily reproduced by replacing only this sweeper bucket.

[0012]

【Example】

 FIG. 1 is a perspective view showing an embodiment of the present invention, and FIGS. 2 (A) and 2 (B) are a vertical side view and a front view in the vicinity of an input port of the embodiment. The upper part of FIG. 1 is a normal bucket 4, which is completed by press forming and welding assembly of a normal SS steel plate. Each of the buckets 4 is fastened to a predetermined position of the belt 5 at predetermined intervals with bolts 7, and the rake face of the foundry sand to be opened is formed by a front upper part 41 and a side upper part 42.

Shown at the bottom of FIG. 1 is a sweeper bucket 6, which is a feature of the present invention. A high wear-resistant metal plate 63 having a tungsten powder sprayed on the surface is welded to the upper front surface 61 and the upper side surface 62, which are the rake surfaces of the sweeper bucket 6, and the corners of the side surface and the front surface are made of chrome. The fillet weld 64 of the fillet made of carbide metal such as carbide is applied so that the part where the wear is most concentrated is countered with the best wear resistance.

In this embodiment, four bucket buckets 6 each having a width of 500 mm are attached to the bucket elevator, and four sweeper buckets 6 having a width of 520 mm and attached with the above-mentioned high-wear-resistant plate of tungsten spray treatment, As a result of installing them at equal intervals, it was conventionally necessary to replace 67 buckets due to wear in 1.4 years after new installation, whereas in the embodiment of the present invention, it was used for 1.9 years. However, abnormal wear on the rake face of the super bucket 6 was not observed, and it is reported that the outlook for the final life is unclear. According to a comparison test of wear resistance by a wear tester, it is reported that this tungsten sprayed plate had about 18 times the durability of the SS steel plate, but the results are still consistent with the results.

[0015]

[Effect of device]

 As described above, the present invention has the effect of greatly extending the useful life of the bucket against wear and maintaining its function as a bucket elevator for a long time without changing it. Also, even if the life of the rake face of the sweeper bucket is exhausted, it is sufficient to remove the bolts fastening only the four sweeper buckets and renew it. The advantage of contributing to the improvement of the productivity of the foundry itself is significant, such as shortening the stop time of a large bucket elevator to the extent that it is completed within the break time.

[Brief description of drawings]

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

FIG. 2 is a vertical sectional side view (A) and a front view (B) in the vicinity of an input port of the embodiment.

FIG. 3 is a vertical sectional side view showing a general structure of a bucket elevator.

FIG. 4 is a vertical cross-sectional side view illustrating one of the conventional techniques.

FIG. 5 is a vertical cross-sectional front view of the vicinity of the bottom of the case, showing a problem of the conventional technique.

FIG. 6 is a perspective view of a bucket showing a problem of the conventional technique.

[Explanation of symbols]

 1 Case 2 Pulley 3 Pulley 4 Bucket 5 Belt 6 Sweeper Bucket 11 Inlet 12 Outlet 41 Front upper part 42 Side upper part 61 Front upper part 62 Side upper part 63 Metal plate 64 Overlay welding C Belt conveyor

Claims (1)

[Scope of utility model registration request] 1. A case 1 which is vertically installed and has a carrier inlet 11 on one side surface and a carrier outlet 12 on the opposite side surface of the upper portion, and a case 1 which is vertically rotatable in the case 1. In a bucket elevator consisting of a belt 5 endlessly wound between pulleys 2 and 3 pivotally supported on a plurality of buckets mounted at regular intervals, the lateral width of a constant number of buckets 4 is larger than that of other buckets 4. A bucket elevator for transporting foundry sand, characterized in that a sweeper bucket 6 in which a metal plate 63 having high wear resistance is attached to the foundry sand rake face of the front upper part 61 and the lateral upper part 62, which is large in the left and right, is disposed.