JP3191122B2 - Conveyor belt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conveyor belt, and more particularly, to a steel cord which is formed at the time of damage by improving the permeability of rubber and the like into the inside of the steel cord to reduce air permeation in the steel cord. The present invention relates to a conveyor belt in which corrosion is prevented and the life is improved.

[0002]

2. Description of the Related Art In general, a conveyor belt used for conveying relatively lightweight foods or the like is a belt strong ST.
-500 to ST-2000 conveyor belts are used.A plurality of steel cords are buried in parallel along the longitudinal direction of a belt-shaped belt made of rubber, plastic, etc. Is configured.

[0003] By the way, conventionally used belt strong
As a spiral type steel cord used in the conveyor belt of ST-500 to ST-2000, for example,
Around three adjacent element wires having the same diameter adjacent to each other, three first element wires having the same diameter disposed at positions facing the contact portions of the central elements, and the three first element wires having the same diameter. And three second side wires of the same diameter, which are arranged between the first side wires and have a smaller diameter than the first side wires, the first side wires and the second side wires. Around the wires, twelve third side wires having the same diameter are arranged.

In this steel cord, a first side wire, a second side wire, and a third side wire are arranged around three center wires, and the same length, the same twist length and the same length are simultaneously formed. The cord structure is usually 3+ (3
+3) +12, which is expressed as 1 × W (21) in a broad sense from the manufacturing method. W stands for Warrington type, and this steel cord has all strands laid in parallel.

[0005]

However, the above-mentioned conveyor belt having a spiral-type steel cord is excellent in rupture resistance, but has a third side strand constituting the steel cord. The diameter is the same,
In addition, since the first strand, the second strand, and the third strand are twisted in the same twist length, in the same twist direction, and in parallel twist, and the strands are in line contact with each other, the third strand is in contact with the third strand. The permeability of rubber and the like to the inside is worse than that of the strand, leaving voids inside the steel cord.As a result, the air permeability inside the steel cord increases, and if the conveyor belt is damaged, moisture will , Corrosion of the steel cord occurs, and the strength of the belt and the adhesiveness to the belt are reduced, so that the life of the conveyor belt is significantly reduced.

The present invention has been devised in view of the conventional problems described above, and improves the permeability of rubber and the like into the inside of a steel cord to reduce air permeation in the steel cord, thereby reducing the possibility of breakage. It is an object of the present invention to provide a conveyor belt that prevents corrosion of a generated steel cord to improve the life of the steel cord and also has excellent breaking resistance.

[0007]

According to the present invention, in order to achieve the above object, a steel cord is formed around three adjacent center wires having the same diameter and opposed to each other at a contact portion between the center wires. Three first side wires having the same diameter disposed at the same position, and three same diameters disposed between the three first side wires and having a smaller diameter than the first side wires. , And 9-1 around the first and second side wires.
The center strand, the first strand, and the second strand of a conveyor belt including five third strands having the same diameter are formed in the same twisting direction, and the center strand is formed. Wire, first side strand,
The gist is that the twist length of the second strand is 0.6 to 0.9 times the twist length of the third strand.

[0008]

The present invention is configured as described above, and has a central element wire,
The first strand and the second strand are configured in the same twist direction, and the twist length of the center strand, the first strand, and the second strand is set to the third strand. 0.6 to 0.9 times the twist length of the third strand and the cross strand, the third strand and the first strand inside the third strand and the The two side strands are in point contact with each other to form a gap between the strands, so that the permeability of rubber and the like at the time of forming the conveyor belt can be improved.

Also, since the permeability of rubber and the like into the steel cord is good, the voids remaining inside the steel cord are reduced, the air permeability is reduced, and the amount of air permeated is reduced. Obedience
Therefore, even if the conveyor belt is damaged, it is difficult for moisture to penetrate into the steel cord, preventing corrosion of the steel cord, suppressing reduction in belt strength and adhesion to the belt, and reducing the conveyor belt. Long life can be maintained.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partially cutaway perspective view of a conveyor belt according to the present invention. As shown in FIG. 1, a conveyor belt 1 includes a belt body 2 made of rubber, plastic, or the like, and a belt body 2 for reinforcing the belt body 2. And a plurality of spiral-type steel cords 3 buried in parallel along the longitudinal direction.

[0011] This steel cord 3 is shown in FIGS.
As shown in (c), three center wires 3a having the same diameter adjacent to each other and arranged around the three center wires 3a at positions facing the contact portions between the center wires 3a. Three first strands 3b having the same diameter, and three strands disposed between the three first strands 3b and having a diameter smaller than the first strand 3b. And the second side strand 3c having the same diameter.

Around the first side wire 3b and the second side wire 3c, 9 to 15 third wires having the same diameter are provided.
A side strand 3d is provided. This third side wire 3d is 9-1
If the number of wires is less than 9, the wire diameter of the third side wire 3d becomes large, so that the generated bending stress increases and the durability against bending fatigue decreases. If the number of wires exceeds 15, the wire diameter of the third side wire 3d becomes thin, so that the cross-sectional area reduction rate due to internal wear increases, and the durability decreases.

In the steel cord 3, the central strand 3a, the first strand 3b, and the second strand 3c are formed in the same twisting direction, and the third strand 3d is connected to the center. The twist length is configured to be larger than the twist length of the strand 3a, the first strand 3b, and the second strand 3c. That is, the center strand 3a, the first side strand 3b, and the second
The side strands 3c are in line contact with each other and twisted in parallel,
The third side wire 3d is a centrally twisted central wire 3a,
The first side wires 3b and the second side wires 3c are twisted in the same twisting direction so as to have a small gap therebetween while intersecting with the third side wires 3c.

The twist length of the center strand 3a, the first strand 3b, and the second strand 3c is 0.6 to 0.5 times the twist length of the third strand 3d. 9 times, that is, the center strand 3a, the first side strand 3b, and the second side strand 3c twisted in parallel with each other, and the center strand 3a, the first side strand 3b,
The twist length ratio between the second side wire 3c and the third side wire 3d intersecting with the second side wire 3c is 0.6 to 0.9.

If the twist length ratio is less than 0.6, the air permeation amount of the steel cord 3 is extremely low, which is good, but the cutting load of the steel cord 3 is low and the rupture resistance is reduced (substantially inferior). On the other hand, if the twist length ratio exceeds 0.9, the amount of air permeation through the steel cord 3 cannot be sufficiently suppressed. Thus, the center strand 3a, the first
The side strand 3b and the second side strand 3c are configured in the same twist direction, and the twist length of the center strand 3a, the first side strand 3b, and the second side strand 3c is set to Since the twist length of the three-side strand 3d is set to 0.6 to 0.9 times, a structure having a parallel twisted portion and a cross-twisted portion is provided, and the third side strand 3d and the first wire inside the third side wire 3d are formed. The side strands 3b and the second side strands 3c are in point contact with each other to form a gap between the strands, thereby improving the permeability of rubber and the like to the steel cord 3 when the conveyor belt 1 is formed. I can do it.

Further, the voids remaining inside the steel cord 3 after the vulcanization molding of the conveyor belt are reduced, the air permeability is reduced, and the air permeability inside the steel cord is reduced.
You. Therefore, even if the conveyor belt 1 is damaged, moisture hardly penetrates into the steel cord 3, preventing corrosion of the steel cord 3 and suppressing reduction in belt strength and adhesion to the belt body 2. Thus, the life of the conveyor belt 1 can be maintained long.

Since the steel cord 3 is twisted in two steps by changing the twist length of the third strand 3d, the name is 1 ×.
CW (21), 1 × CW (18), 1 × CW (24),
That is, it is described as covered Warrington. Next, as shown in FIG. 2, each steel cord (1 × CW (21),
× CW (18), 1 × CW (24)) as a reinforcing material, prototyped a conveyor belt having the specifications shown in Table 1 below, under the conditions shown below, an air permeation test of steel cord in the belt, and internal wear. A test, an internal corrosion test, and a belt durability test were performed.

[0018] 1. Air permeation test The produced conveyor belt was cut into a length of 500 mm in the longitudinal direction, and as shown in FIG. 3, 0.5 kgf / cm ² of air was passed from one end of a steel cord section in the conveyor belt.
The amount of air exiting from the other end was measured and indicated by the amount of air permeated per minute. 2. Internal Abrasion Test As shown in FIG. 4, one steel cord taken out of the produced conveyor belt is bent into a semi-arc shape, and one end is rotated by a motor M in the bent state. Every one rotation, the relative position of each strand constituting the steel cord changes, and wear occurs between the strands. (1). Test time (number of cord revolutions) 90 million times (2). Measurement items a) Cutting load of steel cord b) Reduction rate of cross-sectional area of third strand (3). The radius at which the steel cord is bent is 700 times or more the representative strand diameter in order to eliminate the influence of bending stress. Seven 10019 72 2. Internal Corrosion Test As shown in FIG. 5, the center of one steel cord taken out of the produced conveyor belt is scratched with a scalpel until the steel cord reaches from the surface of the steel cord to the inside of the steel cord. The steel cord is bent into a semicircular arc, and one end is rotated by a motor M in a state where the steel cord is immersed in a 10% concentration of salt water. If there is a gap inside the steel cord, the salt water penetrates into the inside of the steel cord from the wound part inserted with a scalpel, and each strand of the steel cord is corroded by the salt water. The steel cord after the corrosion test is disassembled, and the corrosion degree of the wire of the steel cord at the damaged portion is observed and determined. (1). Judgment criteria No corrosion 0 Very slight corrosion 1 Moderate corrosion (only on one side) 2 Significant corrosion (on both sides) 3 (Rubber adhesion is also reduced and practically unusable) Very corrosive (over the entire surface) 4 (Rubber adhesion) (2). Test time 1 million times (steel cord rotation speed) (3). The radius at which the steel cord is bent is 700 times or more the representative strand diameter in order to eliminate the influence of bending stress. 4. Belt durability test Use two pulleys with a pulley diameter of 500 mm.
The conveyor belt produced was attached to each of the pulleys (safety factor: 7.0), and the cutting load (kgf / piece) of the steel cord after 5 million times of passing through the pulley was measured. 1 x CW
(21) The test results of the examples performed by changing the twist length for each steel cord of 1 × CW (18) and 1 × CW (24) are shown in the following tables including the conventional example and the comparative example. 2, Table 3 and Table 4. In addition, the twist reduction rate (%) of the used steel cord and the raw cord cutting load (kgf / piece) before use are also shown for reference.

[0019]

[0020]

As apparent from Table 2, 1 × CW (2
1) In the case of a steel cord having a structure, the twist length ratio is 0.1 mm.
At 6 to 0.9 times, rubber permeability is good,
20cc / m air permeation rate of steel cord in beer belt
in or less, and the internal corrosion degree of the steel cord was evaluated as 2 or less, which was good. Furthermore, the reduction rate of the wire cross-section due to the internal wear of the steel cord is as small as 10% or less, the breaking force of the steel cord can be kept as high as 95 or more, and a conveyor belt having a long life and excellent durability can be obtained. You can see that it can be done.

In the comparative example having a twist length ratio of 0.5, the air permeability of the steel cord was small and the rubber permeability was good, but the cross section of the strand was reduced due to internal wear of the steel cord. The rate was as large as 30%, and the breaking strength of the steel cord was 90, which was an index value, and was greatly reduced, which was not a level that would practically endure a long life. On the other hand, 1 × W (21) which is a conventional example in which the twist length ratio is 1.0 times
In the case of the configuration, the air permeability of the steel cord is 85cc / m
In, the rubber permeability was poor, and the degree of internal corrosion of the steel cord was evaluated as 4, which was worse, and was not at a level that would practically endure a long life.

Further, 1 × C having a different steel cord structure
Even in the case of W (18), 1 × CW (24), Table 3
As is evident from Table 4 and Table 4, as in the above, the air permeability of the steel cord was small, the rubber permeability was good, and the internal corrosion degree of the steel cord was good, as described above. Further, it can be seen that the reduction rate of the wire cross-section due to the internal wear of the steel cord is small, the breaking force of the steel cord can be kept high, and a conveyor belt having a long life and excellent durability can be obtained.

[0024]

According to the present invention, the center wire, the first side wire and the second side wire are formed in the same twist direction, and the center wire, the first side wire and the second side wire are formed in the same twist direction. By setting the twist length of the side strand to 0.6 to 0.9 times the twist length of the third side strand ,
It has the following excellent effects. (1) A structure having a portion where wires are twisted in parallel and in contact with each other and a portion where wires are cross-twisted and in point contact with each other, the third wire and the first wire inside the third wire and the second wire A gap is formed between the side wires and the side wires, so that the permeability of rubber and the like into the steel cord is improved when the conveyor belt is formed. Since (2) permeability of rubber or the like into the scan steel code is good,
The air gap remaining inside the steel cord of the conveyor belt is reduced, reducing air permeability and reducing air permeability.
Therefore, even if the conveyor belt is damaged, moisture hardly penetrates into the steel cord, prevents corrosion of the steel cord, suppresses the strength of the belt and lowers the adhesive strength with the belt body, Long life
I can do it. (3) As long as the twist length ratio between the third strand and the first strand and the second strand inside the third strand is maintained at 0.6 to 0.9, the conventional Warrington type Breaking strength close to that of steel cord can be maintained .

[0025]

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of a conveyor belt according to the present invention.

FIGS. 2A, 2B, and 2C each show a code structure of 1 × CW (21), 1 × CW (18), and 1 × CW
It is sectional drawing of the (24) steel cord.

FIG. 3 is an explanatory diagram illustrating an air permeation amount test of a steel cord.

FIG. 4 is an explanatory diagram illustrating an internal wear test of a steel cord.

FIG. 5 is an explanatory diagram illustrating an internal corrosion test of a steel cord.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conveyor belt 2 Belt main body 3 Steel cord 3a Center strand 3b 1st strand 3c 2nd strand 3d 3rd strand

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B65G 15/30-15/58

Claims (1)

(57) [Claims] 1. A belt-shaped belt body, and a plurality of steel cords embedded in the belt body in parallel in a longitudinal direction, wherein the steel cords are adjacent to each other and have three central elements having the same diameter. Three first wires of the same diameter arranged around the wire at positions facing the contact portions of the central strands
A side strand, and these three first side strands are arranged between each other;
And three second side wires having the same diameter smaller than the first side wire, and 9 to 15 third sides having the same diameter around the first and second side wires. In a conveyor belt provided with strands, the central strand, the first side strand, and the second strand
And the side strands are configured in the same twist direction, and the center strand,
A conveyor belt, wherein the twist length of the first strand and the second strand is 0.6 to 0.9 times the twist length of the third strand.