JPH07188673A - Cutter for rod pitch - Google Patents

Abstract

PURPOSE:To provide a cutter for a rod pitch whereby a cut rod pitch having edge-free nonburred cutting edges and high drop impact strength is produced even from a rod pitch of a large diameter by arranging edges of a specified shape equidistantly and symmetrically on a pair of rotating rolls. CONSTITUTION:This cutter is one used for cutting a continuous rod pitch into a shaped and cut rod pitch of a specified length and consists of a pair of synchronously rotating rolls spaced from each other at a specified distance, and shaping and cutting edges arranged equidistantly on each roll and arranged symmetrically with the opposed edges on the mating roll, the opposed edges 5 on the mating rolls being adapted so that the above continuous rod pitch may be shaped and cut when the edges 5 are in mesh with each other. Each edge 5 has a spherical top face 5b and at least one pair of recesses 7 extending from the top face to the inside and being symmetrical in relation to the direction of rotation and movement of the edge, and adapted so that at least the inside surface part 5C at the boundry of the adjoining recesses 7 may from a roundish surface or a conical surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting device for manufacturing a rod-shaped pitch by forming and cutting a continuous rod-shaped pitch.

[0002]

2. Description of the Related Art Conventionally, there are various methods for producing solid pitch ("Aromatic and Tar Industry Handbook", December 1978, published by Japan Aromatic Industry Association). Among them, in the vertical cooling tank type as a manufacturing method of the rod-shaped pitch, after cooling the pitch manufactured in the previous step to some extent, it is made to flow out from the pitch nozzle into the water in the cooling tank, and the pitch solidified into a rod shape is cooled in the cooling tank It is cut by a screw conveyor with a cutter installed near the bottom and carried out of the cooling tank by a bucket elevator. The final product was obtained by drying these pellets.

However, in the above-described rod-shaped pitch manufacturing method, since the pitch is cut by the cutter many times in the cooling tank, powder, debris, etc. are generated, resulting in poor yield and working environment. There was a problem that it was also bad. Also, this pitch has a corner (edge) on the end face.
Therefore, there is a problem that the end face is crushed and pulverized in the transportation work, and the product yield is lowered, the product quality is lowered, and the working environment is deteriorated. Further, since such a pitch is rapidly solidified by cooling, the diameter of the rod is thin, and there is a problem that holes, cavities, or moisture are likely to remain inside and the strength is weak.

Then, a method of cutting and forming the pitch shape in water is disclosed in, for example, JP-A-60-101190, JP-B-61-23957 and JP-A-63-139981.

However, the pitch obtained by these methods is not a rod-like shape but a substantially spherical shape, is weaker to drop impact (prone to powdering) than a bar-like product, and has a small angle of repose and thus is unstable at the time of storage (mounting height). Cannot be increased), which is a problem in handling characteristics. In addition, since the pitch in the molten state with low viscosity is extruded into the water in the cooling tank and cut at the same time as extruding, it is deformed by the resistance due to water, and the density change during rapid solidification is large and residual stress and internal voids are generated. There is a problem that there is a high possibility that defects are likely to occur.

As a method for solving the above problems, Japanese Patent Application No. 4-241556 discloses a method of gradually cooling a pitch,
After adjusting the viscosity to 1,000 to 100,000 poise, extrusion molding from a die and cutting with a guillotine type or roll type cutter (flat plate blade) to produce a rod-shaped pitch with excellent strength, formability, and compactness. The method is successful.

In this method, the shape of the cut surface is improved as compared with the conventional method, but in such a cutter device with a flat blade, when the viscosity increases during pitch cutting, the thread may be pulled. However, the problem of producing edges and burrs in the diameter direction of the rod is not completely solved. In particular, as the cut surface is large and the rod diameter of the pitch is large, the edge relaxation effect due to the surface tension of the pitch is difficult to proceed, that is, the edge portion is likely to remain.

[0008]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and manufactures a rod-shaped pitch which is resistant to a drop impact without causing edges or burrs on the end face even with a rod-shaped pitch having a large diameter. It is an object of the present invention to provide a cutting device.

[0009]

That is, the present invention is a device for cutting a continuous rod-shaped pitch while forming it into a rod-shaped pitch having a predetermined length, and a pair of synchronously rotated rolls separated by a predetermined distance. , Forming cutting blades arranged on each roll at equal intervals and symmetrically between the opposing rolls, and the corresponding blades on the opposing rolls form and cut the continuous bar pitch when they meet. Each blade has a spherical top surface, has at least one pair of recesses symmetrical from the top surface to the inside in the rotational movement direction of the blade, and at least the inner surface portion adjacent to each other is rounded. The present invention provides a rod-shaped pitch cutting device having a curved surface or a conical surface.

[0010]

The continuous rod-shaped pitch extruded from a die or the like is fed to a pair of rotating rolls by a blade symmetrically arranged on both rolls and equidistantly arranged on each roll. When the blades on both rolls are rotationally associated with each other, the rod-like pitch having a predetermined length is cut by adjusting the rotation speed of the roll. At this time, the blade arranged on the roll has a shape that can be cut while molding the end portion of the continuous rod-shaped pitch to be cut. As a result, edges and burrs do not occur on each of the cut rod-shaped pitches, and because they are well-shaped, they will not be chipped or powdered when dropped after handling or during handling. A rod-shaped pitch is obtained.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The rod pitch cutting device according to the present invention will be described in detail below with reference to the preferred embodiments and experimental examples shown in the drawings. Conventionally, a flat blade 1 as shown in FIG. 1 is formed on a pair of rolls 2 and 2 as shown in FIG. 2 by a rotary cutter in which blades on each roll are symmetrically arranged at substantially equal intervals. The continuous rod-shaped pitch 4 supplied from 3 or the like was cut. At this time, as described above, the cut rod-shaped pitch had a problem as described above. It turned out that there was a problem with the shape or structure of the blade. Only three blades on each roll are shown and the others are omitted.

Therefore, in the present invention, the shape and structure of the blade arranged on the roll is changed. The conventional blade has a flat plate shape, and merely has an effect of cutting the rod-shaped pitch, and therefore the edge portion and the burr are formed on the cut bar-shaped pitch. The blade used in the present invention is formed and cut when cutting a continuous rod pitch. The blade used in the present invention will be described below.

First, examples of the structure of the blade used in the present invention are shown as 5 and 6 in FIGS. 3 and 4, respectively. In both the examples shown in FIGS. 3 and 4, the overall shape is a semi-cylindrical shape, the bottom surfaces 5a and 6a are mounted on the roll 2, and the top surfaces 5b and 6b rotate on the roll 2 and meet each other. A spherical surface is formed so as to be in close contact.

In the example shown in FIG. 3, the semicylindrical blade 5 is formed with a concave portion 7 serving as a blade for molding and cutting from the spherical top surface side, and this concave portion has a spherical concave surface 5c. ..
As will be described later, the line formed by the top surface 5b of the blade 5 and the concave portion 7 having this spherical surface becomes the cutting line 5d, and the spherical concave surface 5c becomes the molding surface. Further, the concave portions 7 of the spherical concave surfaces 5c, 5c are formed on one blade vertically and symmetrically in the rotational direction as shown in FIG. These adjacent recesses 7, 7 are independent at the ends of the recesses and are not continuous. As a result, the continuous bar-shaped pitch is clearly cut into adjacent bar pitches between the both recesses.

In the example shown in FIG. 4, the surfaces 6c, 6c of the recess 7 are
Is similar to the example shown in FIG.

In FIG. 5, the blades 5 having the concave portions 7, 7 having the spherical surface 5c shown in FIG. 3 are arranged at equal intervals on the rolls 2, 2 and the blades 5 on each roll are symmetrical. 1 shows an example of a cutting device according to the invention arranged. The continuous rod-shaped pitch 4 supplied from the die 3 is cut while being formed by the blade 5. The cutting is performed where the blades 5 and 5 on both rolls 2 and 2 meet with each other. Only three blades on each roll are shown and the others are omitted.

This state will be described with reference to FIG. Figure 6
The moment when the continuous rod-shaped pitch 4 is cut is shown. The upper pitch is a continuous rod-shaped pitch 4, the lower pitch is a cut rod-shaped pitch 4a, and this rod-shaped pitch 4a has its lower end surface 4c formed by the concave surface of the leading blade 5 which has already passed, and is cut into clear pieces. You can see that it is done.

As shown in FIG. 6, continuous rod-shaped pitch 4
Starts to come into contact with the recesses 7, 7 of the blades 5, 5 due to the approach of the blades 5, 5 on the rolls 2, 2 by rotation, and the continuous rod-shaped pitch 4
Is gradually narrowed by the cutting lines 5d, 5d of the concave portions 7, 7, and at the same time, the portion narrowed by the spherical surfaces 5c, 5c is molded and finally cut by the association of the cutting lines 5d, 5d. The operation of forming and cutting with such blades 5 and 5 has not been performed by the conventional cutting blade and apparatus shown in FIGS.

Further, as shown in FIG. 6, it is considered that the concave portion 7 of the blade 5 forms a guide portion 7a and a molding cutting portion 7b for the continuous rod-shaped pitch 4. The diameter of the recess 7 is larger than the diameter of the continuous rod-shaped pitch 4, and the recess 7 has a guide portion 7a.
After passing through, it seems that they are contacted and molded and cut. Considering that point, the guide portion 7a is not necessarily shown in FIGS.
It is not necessary to form a spherical surface or a conical surface as exemplified in 1., but it may be a cylindrical shape. Therefore, it suffices that the portion 7b involved in molding cutting has a spherical shape or a conical shape.

The surface shape of the cut-and-formed portion 7b of the concave portion 7 is not limited to the shape illustrated in FIGS. 3 and 4, and may be any shape that allows the cut and formed, and should have a rounded concave surface. Good. Therefore, the rounded shape is not limited to a spherical shape, and may be an elliptical shape or any other rounded shape whose curvature cannot be clearly defined.

Here, the blade 7 may be made of any material as long as it can cut the pitch, but it is preferably made of a metal material such as stainless steel.

According to the examples shown in FIGS. 3 and 4, since the blade of the roll type cutter has a spherical shape as shown in FIG. 3 or has a conical shape as shown in FIG. 4, the pitch section has a spherical shape or a substantially conical shape. As a result, the bar pitch can be manufactured without an edge portion. Here, when the cutter has a spherical shape, it is desirable to set the radius of curvature to about 1.2 to 3 times the rod pitch diameter in terms of high strength of the cut portion against a drop impact. Further, in the case of conical shape, if the apex angle of the conical portion is designed to be 3.1 to 6.1 steradian, the surface tension of the pitch also contributes to provide an excellent shape during molding.

The viscosity of the rod-shaped pitch cut by the cutting device of the present invention is preferably 1,000 to 100,000 poises. When the melt pitch viscosity is lower than 1,000 poise, the pitch falls in a molten state and the shape of the molding pitch becomes a tear drop shape, so that it easily breaks during transportation.
Further, when the viscosity of the molten pitch is higher than 100,000 poise, the pitch is almost solid, the cutter is overloaded, the life of the blade is shortened, and the fracture surface is also smoothed by the surface tension. It cannot be obtained and the shape becomes poor.

The present invention will be described in more detail below. (Invention Example 1) In this example, in the rotary cutter shown in FIG. 5, the radius from the rotary shaft to the tip of the blade is 250 m.
m, and the radius of curvature of the spherical surface portion of the concave portion of the blade was 30 mm. Softening point (Ring & Ball method JIS K 2425)
The melt pitch of 108 ° C. was adjusted by a screw extrusion type cooling molding device to adjust the temperature to 20,000 poise, and then the mixture was extruded downward into the air by screw extrusion from a die having a circular cross section with a diameter of 15 mm. 80m in length by adjusting the amount of pitch extrusion and the number of rotations of the rotary cutter.
A bar pitch of m and a diameter of 15 mm was obtained. The amount of pitch processing at this time was about 40 kg / hr.

(Invention Example 2) In this example, the rotary cutter shown in FIG. 5 has a radius from the rotary shaft to the tip of the blade of 250 mm and a radius of curvature of the spherical surface portion of the concave portion of the blade of 30 mm. . Softening point (Ring & Ball method JI
SK 2425) adjusts the temperature of the molten pitch of 108 ° C by a screw extrusion type cooling molding device,
After adjusting to Poise, extrude downward into the air by screw extrusion from a die with a circular cross section with a diameter of 22 mm,
Molded with this rotary cutter, the pitch extrusion amount and the rotation number of the rotary cutter were adjusted to obtain a bar pitch having a length of 80 mm and a diameter of 22 mm. The pitch processing amount at this time was about 80 kg / hr.

(Comparative Example 1) In this example, the blade was replaced with a flat plate cutter (the apparatus shown in FIG. 2 using the blade shown in FIG. 1) under the same conditions as in Example 1 of the present invention.

(Comparative Example 2) In this example, the blade was replaced with a flat plate cutter (the apparatus of FIG. 2 using the blade shown in FIG. 1) under the same conditions as in Example 2 of the present invention.

In each of Examples 1 and 2 of the present invention, which are application examples of the present invention, a pitch having no edge in the cross section was obtained, and the molding effect of the present invention was confirmed. On the other hand, in the case of the conventional rotary blade type rotary cutter, in the case of the comparative example 1, the one having a small edge can be manufactured, but in the case of the comparative example 2 having a large bar diameter, it has a sharp edge. This indicates that the bar pitch was crushed as the cutter cut the pitch. When the rod diameter is small, the crushed portion is small, so it seems that the tension is relaxed during the cooling process. Table 1 shows the results of the impact dusting test at three levels, in which the conventional water tank quenching method was added to the above-mentioned prototype sample. From this, the powder generation rate decreased in the order of Conventional method> Comparative example> Experimental example of the present invention, and the prevention of pulverization by suppressing the edge of the cross section was confirmed as the effect of the present invention.

[0029]

[Table 1]

[0030]

EFFECTS OF THE INVENTION According to the present invention, the cutting surface has a rounded shape in order to cut the melted pitch having a high viscosity, which is different from the conventional one, while the cutter forms the rounded surface while cutting it.
No edges remain. For this reason, it is resistant to drop impact, powdering during handling does not occur easily, and the yield and working environment are improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a conventional flat blade.

2 is a schematic side view of a cutting device using the flat blade of FIG. 1. FIG.

FIG. 3 is a perspective view of an example of a cutter blade of the cutting device of the present invention.

FIG. 4 is a perspective view of another example of the cutter blade of the cutting device of the present invention.

5 is a schematic side view of a cutting device of the present invention using the blade of FIG.

FIG. 6 is an explanatory view showing the action of the blade of the cutting device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flat blade 2 Roll 3 Forming die 4 Continuous rod pitch 5,6 Blades used in the device of the present invention 5a, 6a Bottom surface 5b, 6b Top surface 5c, 6c Spherical, conical surface 5d, 6d Cutting line 7 Recess 7a Guide portion 7b Molded cutting part

Claims (2)

[Claims] 1. A device for cutting a continuous rod-shaped pitch while forming it into a rod-shaped pitch having a predetermined length, which comprises a pair of synchronously rotated rolls spaced apart by a predetermined distance and facing each other at equal intervals. Forming blades symmetrically arranged between the rolls, the corresponding blades on the opposing rolls are configured to form and cut the continuous rod pitch when they meet, each blade having a spherical top. At least one pair of concave portions having a surface and symmetric with respect to the rotational movement direction of the blade from the top surface to the inside, and at least the inner surface portion adjacent to each other of the concave portions forms a rounded surface or a conical surface. Characteristic rod-shaped pitch cutting device. 2. The rod pitch cutting device according to claim 1, wherein the rounded surface is spherical or elliptical.