JP2003312823A - Air-floatable belt conveyor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air-floatable belt conveyor capable of maintaining friction between a conveyor belt and a trough at a low level for a long period. <P>SOLUTION: In this air-floatable belt conveyor A, air is sent into between the trough 5 and the conveyor belt 1 to let the conveyor belt 1 float. On the surface of the trough 5 on the side to get in contact with the conveyor belt 1, a coating layer 10 having low friction performance and abrasion resistance performance is formed. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air levitation type belt conveyor for supplying air between a trough and a conveyor belt to levitate the belt, and carrying an object to be conveyed on the belt. It is about.

[0002]

2. Description of the Related Art An air levitation type belt conveyor is generally constructed as shown in FIGS. 2 (a) and 2 (b). That is, a pair of pulleys 2 and 3 arranged at a considerable distance.
In the meantime, a continuous annular / endless conveyor belt 1 is bridged, and the pulleys 2 and 3 (either or both) are rotationally driven to circulate and move the belt 1. On the upper surface of the wound belt 1 on the upper side, the transported object X
The object X to be conveyed can be conveyed by placing the. Troughs 4 and 5 are arranged along the lower surface of the belt 1 on the upper and lower paths along which the belt 1 moves. A curved surface (or a cylindrical surface) shown in FIG. 2B is formed on the upper surfaces of the troughs 4 and 5, and the belt 1 is curved so that the upper surfaces thereof are concave. In order to reduce the friction between the belt 1 and each trough 4.5, the trough 4
5, pressurized air is sent from below, and the trough 4
An air layer is formed between the upper surface of 5 and the lower surface of the conveyor belt 1. Reference numerals 4a and 5a in the drawing are a plurality of air supply holes formed on the center line along the longitudinal direction of the troughs 4 and 5, and reference numeral 6 is an air supply source such as an air compressor,
Reference numeral 7 is an air supply pipe connecting the air supply source and each air supply hole.

A general anticorrosive paint is applied to the metal portion of the air floating type belt conveyor for the purpose of rust prevention and corrosion prevention, and the upper surface of the trough is generally treated in the same manner. In addition, in Japanese Unexamined Patent Publication No. 2001-48330, a Teflon sheet (“Teflon” is a registered trademark The same applies to the following) is also proposed to attach a low friction member.

[0004]

According to the research conducted by the inventors, it has been found that in the air floating belt conveyor, the upper surface of the trough or the like is worn more than expected when the usage conditions are not appropriate. It is that the belt moves at a high speed of several meters per second, and if particles or powder in the conveyed object gets between the belt and the trough for some reason, it tends to promote wear, It seems that there is a reason. Also, when the object to be transported is not placed, the belt tends to be flat, so that the left and right edges of the belt (left and right with respect to the belt feeding direction) easily come into contact with the trough. Depending on the relationship with the situation etc., contact between the belt and the trough may occur quite frequently, causing wear.

When such inconvenient conditions are met, the conveyor is operated even if a trough coated with a general rust preventive paint or a low friction member such as a Teflon sheet is used as in the conventional case. Then, the layer of the paint or the low friction member may be worn or worn out in a short period of time. Then, with the contact between the belt and the trough, even if a low-friction member is attached, the friction increases after the abrasion, and therefore the required driving force of the belt also increases, and further, the belt driving force increases. Noise often occurs as the user moves.

The present invention provides an air levitation type belt conveyor capable of keeping the friction between the conveyor belt and the trough at a low level for a long period of time.

[0007]

An air levitation type belt conveyor according to claim 1 is an air levitation type belt conveyor for supplying air between a trough and a conveyor belt to levitate the belt. It is characterized in that a coating layer having low friction and abrasion resistance is formed on the surface of the trough on the contact side. The low frictional property here means that the coefficient of dynamic friction between the same rubber as the conveyor belt and the coating layer is 0.8 or less. Also, abrasion resistance means JIS-K7204.
In the wear resistance test specified in 1
g, rotation speed of test piece 72 rpm, total number of rotations 100
When using 0 times and using # 180 abrasive paper on the outer circumference of the wear wheel, the weight reduction amount (wear mass) is 1.5 g
It means the following properties. It is desirable that the coating layer and the trough have an adhesive force of 10 _kgf / cm ² or more.

According to such an air levitation type belt conveyor, the friction between the conveyor belt and the trough can be kept at a low level for a long period of time, and it is possible to prevent generation of abnormal noise and increase in required power for a long time. This is because the coating layer having not only low friction properties but also abrasion resistance as described above is formed on the upper surface of the trough, that is, the surface in contact with the belt. If the coating layer has abrasion resistance, the belt moves at a high speed as described above, and even if powder particles or the like enter between the belt and the trough or the belt and the trough come into frequent contact with each other, The coating layer having low friction does not wear or wear in a short period of time, and therefore the belt can be smoothly fed for a long period of time. According to the research conducted by the inventors, if the wear resistance and the low friction property satisfy the above-mentioned standards, the practicality of the belt conveyor is remarkably improved.

In the air levitation type belt conveyor according to a second aspect of the present invention, as the coating layer, a Ni-P plating (nickel-phosphorus composite plating) layer in which fluororesin or BN (boron nitride) is dispersed is applied. It is characterized by having done.

Since the coating layer has both abrasion resistance due to Ni-P plating and low abrasion resistance due to fluororesin or BN which is a dispersion substance, in such an air floating type belt conveyor, the space between the conveyor belt and the trough is reduced. The friction can be kept at a low level for a long time.
The plating thickness is preferably in the range of 0.05 to 0.5 mm. If it is thinner than 0.05 mm, film defects such as pinholes are likely to occur, and if it is thicker than 0.5 mm, the plating layer is likely to peel off due to the residual stress of plating.

The air levitation type belt conveyor according to a third aspect of the present invention includes, as the coating layer, a sprayed coating of Co (cobalt) containing WC (tungsten carbide) or Cr ₃ C ₂ (chromium carbide), or WC. Alternatively, it is characterized in that a sprayed coating of NiCr (nickel chrome alloy) containing Cr ₃ C ₂ and having a polished surface is applied.

The above-mentioned thermal spray coating has a very high abrasion resistance because it contains a hard substance, and has the property that the abrasion is less likely to progress than that of an ordinary iron plate or the like. It is also sufficiently preferable for low friction against rubber and the like. Since the surface of such a sprayed coating is used by polishing instead of being in the sprayed state, there is no fear that the hard coating will wear the rubber surface of the conveyor belt. The thickness of this thermal spray coating is also preferably in the range of 0.05 to 0.5 mm. If it is thinner than this range, coating defects such as pinholes are likely to occur, and if it is too thick, the thermal spray coating is likely to crack and peel off.

The air levitation type belt conveyor according to a fourth aspect is characterized in that a coating material containing glass flakes is applied as a coating layer.

Since the coating material containing glass flakes contains a hard material, it has high wear resistance and can be made thicker than general rust preventive paint.
Withstands long-term use until it wears out even under the condition of contact with a conveyor belt. It is also perfect in terms of low friction with the belt. Further, since coating (spraying or brush coating) is used instead of plating or thermal spraying, there is an advantage that the coating layer can be easily formed at the installation site of the conveyor. The film thickness of this coating is 0.5-
It is preferably within the range of 5 mm. If it is thinner than this range, coating defects such as pinholes are likely to occur, and if it is thicker, the coating is likely to crack and peel off.

The air levitation type belt conveyor according to a fifth aspect is characterized in that a thick film epoxy paint is applied as a coating layer.

The thick film epoxy paint is preferable in low friction property, has excellent abrasion resistance unlike ordinary epoxy paint, and can be applied with a thickness of about 1 mm in one day. Preferred as a coating layer on a belt conveyor. Further, the coating layer of this paint can be easily formed on an existing conveyor by a simple operation. Since it is painting (spraying or brush painting), construction at the installation site of the conveyor is easy, and when coating on general rust preventive paint that has already been painted, it is sufficient to paint in a short period of time. This is because it has durability. For this paint as well, for the same reason as the above-mentioned paint, the film thickness is 0.5 to 5 mm.
It is preferable to be in the range.

The air levitation type belt conveyor according to claim 6 is a resin sheet of polyethylene (ultra high molecular weight polyethylene having a molecular weight of 3,000,000 to 6,000,000) or a glass mat-containing FRP sheet (for example, unsaturated polyester) as a coating layer. , A vinyl ester resin or an epoxy resin impregnated with a glass mat) is applied.

The polyethylene resin sheet or the glass mat-containing FRP sheet has excellent low friction and abrasion resistance, and can be made thicker (for example, 2 mm or more) than paints. Also, these sheets can be easily attached to the surface of the trough (unpainted or unpainted) using an adhesive, and at that time it is not difficult to give sufficient adhesion to the trough. There is an advantage that it can be easily applied to an existing conveyor or the like at the installation site of the conveyor and functions as a coating layer. The thickness of each sheet described above is 0.5 to 10 m.
It is preferably within the range of m. If it is thinner than 0.5 mm, resin defects are likely to occur and the service life until abrasion may be insufficient. If it is thicker than 10 mm, the rigidity of the resin becomes too high and it is suitable for the trough. This is because it becomes difficult to bond them easily.

The air levitation type belt conveyor according to a seventh aspect of the present invention is such that only a portion of the surface of the trough which is in contact with the left and right edges of the conveyor belt (refers to the left and right with respect to the traveling direction) (including the periphery thereof). The above-mentioned coating layer (any one of claims 1 to 6) is formed.

By forming the coating layer only on a part of the surface of the trough (the upper surface of the trough which is in contact with the belt) and not on the whole surface, the cost required for applying the coating layer is reduced. Can and is economical. In spite of the low cost construction, this belt conveyor allows the friction between the conveyor belt and the trough to be kept at a low level for a long period of time. When the conveyor belt has an irregular shape due to how the transported object is placed, or when the conveyor belt tries to spread out in a plane because the transported object does not load, both are generally left and right of the conveyor belt. Only near the edges of the contact the trough. Therefore, if the above coating layer is formed only on the part that contacts the left and right edges of the conveyor belt and its periphery, the friction between the conveyor belt and the trough can be significantly reduced, and that state can be maintained for a long period of time. It becomes. The upper surface of the trough, where the coating layer is not formed, may be generally coated with rust preventive paint or the like, but the low friction member (Teflon sheet or the like, as described above) is provided in the range where the conveyor belt passes above. It does not have to be highly wearable).

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view of a part of the conveyor belt 1 and the trough 5 as seen from above. On the other hand, FIG. 2 is a conceptual diagram showing the air floating type belt conveyor A, FIG. 2 (a) is an overall side view, and FIG. 2 (b) is a sectional view taken along line bb in FIG. 2 (a). The overall structure of the air floating type belt conveyor A is as described above with reference to FIG.

In such a conveyor A, as illustrated in FIG. 1, a coating layer 10 having a low friction property and a high wear resistance is formed on the upper surface of a carbon steel trough 5 (and a trough 4 shown only in FIG. 2). Was formed. In the illustrated example, the coating layer 10 is a portion having a width of about 100 mm including a portion of the upper surfaces of the troughs 5 and 4 in contact with the left and right edge portions of the conveyor belt 1 (such a portion as shown in FIG. Although it was formed only in two places, trough 5.4
A coating layer may be formed on the entire upper surface of the. Alternatively, the coating layer 10 may be formed only on the lower trough 5 on which the conveyor belt 1 moves without placing the object X (FIG. 2B). This is because when the transported object X is not placed, the conveyor belt 1 spreads so as to approach the planar shape, so that the left and right edges are more likely to contact the trough 5 than when the transported object X is placed. Forming the coating layer 10 only on the upper surface of the lower trough 5 in contact with the left and right edges of the conveyor belt 1 and in the vicinity thereof is a method of obtaining a preferable effect while minimizing the construction cost of the same layer 10. is there.

What kind of film or the like is to be formed as the coating layer 10 is selected from the following (1) to (3) and applied. Whichever is adopted, the friction between the constructed trough and the conveyor belt 1 is kept at a low level for a long period of time. Which of the above is selected depends on the construction cost, the durability of the coating layer 10, and whether the conveyor A is an existing one or a new one (the surface of the trough 5 or 4 should be made into a certain state). Can be applied to the coating layer 10) and the like. The following is an example of construction shown for comparison.

A sheet of ultra-high molecular weight polyethylene resin is attached onto the trough with an adhesive on the upper surface of the trough from which dirt and deposits have been wiped off. The thickness of the sheet is 2.0 mm. A paint containing glass flakes is applied by spraying on the upper surface of the trough that has been subjected to appropriate substrate adjustment to a film thickness of 0.5 mm. A glass mat-containing FRP coating is applied to a film thickness of 2.0 mm on the upper surface of the trough that has been appropriately adjusted. A NiCr sprayed coating containing WC is formed by plasma spraying on the upper surface of the trough that has undergone appropriate substrate adjustment, and then the surface is polished to a thickness of 100 μm. Ni-P on the top of the trough that has been appropriately adjusted
Electroless plating with fluororesin dispersed in the plating layer,
Apply a film thickness of 0.1 mm. A thick film of epoxy paint is applied to the upper surface of the trough coated with general anticorrosive paint or chlorinated rubber paint to a film thickness of 1.0.
Apply only mm. When the coating layer 10 is not applied, the upper surfaces of the troughs 5 and 4 are coated with a chlorinated rubber-based paint to a film thickness of 160 μm.

The following tests were conducted in order to examine the low friction and wear resistance of the coating layer 10 of the trough 4 or 5 constructed as described above. First, 100 mm
Steel plate with a square width and a thickness of 3 mm (SS according to JIS
A plurality of sheets (made of 400) are adjusted to SIS (Swedish standard) Sa2.5 by shot blasting, and the same coatings as those mentioned above are formed on the surface thereof or a sheet is attached to obtain a test piece. Then, the following tests A and B are performed on each test piece. Test A: Rubber with a constant load (conveyor belt 1
Of the same material as above) is slid on the surface of each test piece to measure the dynamic friction coefficient between the rubber and the coating. Test B: Using a so-called taper wear tester, JI
A wear resistance test specified in S-K7204 is performed. Specifically, the load on the wear wheel was 1 kg, the rotation speed of the test piece was 72 rpm, and the total number of rotations was 1000 times. Measure the mass (weight loss).

The test results for each test piece are as follows. In the table below, the numerical value in column A is the dynamic friction coefficient as a result of test A, and the numerical value in column B is the wear mass (gram) as a result of test B.

[0027]

[Table 1] Note: In the case of the test piece of (1), when the test of (B) was performed, the coating on the portion in contact with the wear wheel disappeared during the test.

[0028]

According to the air levitation type belt conveyor described in claim 1, the friction between the conveyor belt and the trough is kept at a low level for a long period of time, and the generation of abnormal noise and the increase in the required power are long gone. To be prevented.

Having the above advantages is described in claims 2-7.
The same applies to any of the air levitation type belt conveyors described in 1 above. However, since the belt conveyor according to the fourth and fifth aspects forms the coating layer on the trough surface by painting, there is also an advantage that the construction can be easily performed at the conveyor installation site. Further, with the belt conveyor according to claims 5 and 6, it is possible to easily form the coating layer at the installation site of the conveyor, and further, for example, even on a general rust preventive paint that has already been painted on an existing conveyor, It has the advantage that it can be easily implemented in between. With the belt conveyor according to the seventh aspect, the cost required for applying the coating layer can be reduced and the belt conveyor can be constructed at low cost.

[Brief description of drawings]

FIG. 1 is a perspective view of a part of a conveyor belt 1 and a trough 5 of an air floating belt conveyor A, which is an embodiment of the present invention, viewed from above.

2A and 2B are conceptual diagrams showing an air floating type belt conveyor A, FIG. 2A is an overall side view, and FIG. 2B is a sectional view taken along line bb in FIG. 2A.

[Explanation of symbols]

A Air floating belt conveyor X Transported object 1 conveyor belt 4.5 trough 10 coating layer

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Claims (7)

[Claims] 1. An air-floating type belt conveyor for supplying air between a trough and a conveyor belt to levitate the belt, wherein the surface of the trough in contact with the conveyor belt has low friction and abrasion resistance. An air levitation type belt conveyor having a coating layer formed thereon. 2. The air levitation type belt conveyor according to claim 1, wherein the coating layer comprises a fluororesin or BN dispersed in a Ni—P plating layer. 3. The coating layer is WC or Cr ₃
The air levitation type belt conveyor according to claim 1, wherein the sprayed Co coating or the NiCr sprayed coating containing C ₂ has a polished surface. 4. The air levitation type belt conveyor according to claim 1, wherein the coating layer is made of a paint containing glass flakes. 5. The air levitation type belt conveyor according to claim 1, wherein the coating layer is a thick film epoxy paint. 6. The air floating belt conveyor according to claim 1, wherein the coating layer is a polyethylene resin sheet or an FRP sheet containing a glass mat. 7. The air levitation system according to claim 1, wherein the coating layer is formed only on a portion of the surface of the trough which is in contact with the left and right edges of the conveyor belt. belt conveyor.