JP6736026B2 - Pricking roller - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pricking roller in which a tire rubber material is provided with air vent holes.

In a pneumatic tire manufacturing process, a raw cover is formed by laminating a plurality of sheet-shaped rubber materials for tires. However, if air remains between the laminated rubber materials for tires, This causes deterioration of the quality of the product tire after vulcanization.

For this reason, conventionally, a punching process (pricking process) for forming an air vent hole in a rubber material for a tire before forming a raw cover has been performed. For example, a ply roller having a plurality of cones (pins) is provided in a PLY cutter equipment for a bias process for cutting a ply raw fabric at a predetermined angle to produce PLY, and the ply raw fabric before cutting is pricking roller. And a pin on the roller surface is pressed to form a plurality of air vent holes (Patent Document 1).

At this time, if the temperature of the ply original fabric is low, the hole once formed may be closed due to the elasticity of the rubber. Therefore, the pin is heated by heating the pricking roller that performs the perforating process. ..

Conventionally, as a technique for heating such a pricking roller, a rotating roller in which a heating wire is wound around a tubular body made of iron or a rotating roller in which the heating wire is integrally embedded in an aluminum alloy has been used. (Patent Document 2).

JP, 2013-215908, A JP-A-62-37892

However, in the above-mentioned pricking roller, the roller and the heating wire are brought into contact with each other to directly raise the temperature of the roller surface, so that temperature unevenness occurs on the roller surface. Specifically, the temperature of the roller surface near the heating wire increases, while the temperature of the roller surface away from the heating wire decreases. When holes are formed using a roller having such temperature unevenness, holes cannot be formed uniformly, and therefore the quality of the rubber material may become unstable.

Therefore, it is an object of the present invention to provide a pricking roller that can prevent temperature unevenness from occurring on the roller surface and can perform uniform perforation processing.

The invention according to claim 1 is
A pricking roller provided with a plurality of pins on the surface of a cylindrical roller body,
A sheath heater inserted inside the roller body,
A single or a plurality of through holes for inserting the sheath heater are provided so that a gap is formed between the sheath heater and the inner peripheral surface of the roller body, and the sheath heater is inserted through the through hole. A support material that supports in a state,
An insulating insulator disposed between the sheath heater and the support material is provided,
As a transfer medium air in the gap between the sheath heater and the inner peripheral surface of the roller body, it is configured to transfer the heat from the sheath heater to the surface of the roller body ,
The insulator is a ring-shaped insulator,
Furthermore, the sheathed heater is configured by housing a heating wire inside a metal pipe,
An insulating mica washer is provided between the end surface of the metal pipe and the electrode portion that supplies power to the heating wire.
The mica washer is a ring-shaped mica washer, which is a pricking roller.

The invention according to claim 2 is
The pricking roller according to claim 1, wherein a plurality of the sheath heaters are arranged inside the roller body.

The invention according to claim 3 is
The pricking roller according to claim 2, wherein there are four sheath heaters.

The invention according to claim 4 is
The pricking roller according to claim 2 or 3, wherein the sheath heaters are arranged at equal intervals in the circumferential direction.

The invention according to claim 5 is
The pricking roller according to any one of claims 1 to 4, wherein the insulator is made of porcelain or ceramics.

The invention according to claim 6 is
The pricking roller according to any one of claims 1 to 5, wherein the roller body is made of stainless steel.

According to the present invention, it is possible to provide a pricking roller that can prevent temperature unevenness from occurring on the roller surface and can perform uniform perforation processing.

It is a figure which shows typically the cross-section of the pricking roller which concerns on one embodiment of this invention. It is a figure which shows the state which decomposed|disassembled the pricking roller of FIG. FIG. 2 is a perspective view showing a sheath heater and a support member of the pricking roller of FIG. 1. It is a figure which shows typically the cross-section of the periphery of the support material of the pricking roller of FIG. It is a graph which shows the relationship between the heater temperature and the surface temperature of the pricking roller.

1. Background to the Present Invention Prior to describing the embodiments of the present invention, the background to the present invention will be described.

The inventor first of all, in order to prevent temperature unevenness from occurring on the roller surface, a rod-shaped metal wire (sheath) containing a heating wire and an insulating material (for example, magnesia) for preventing electric leakage, It was considered to insert the sheathed heater into the cylindrical roller body and support the sheathed heater so that a gap is provided between the inner peripheral surface of the roller body and the sheathed heater.

In this case, the heat of the sheath heater is transferred to the roller body by using the air in the gap between the inner peripheral surface of the roller body and the sheath heater as a transmission medium, and the heat generated from the sheath heater is appropriately dispersed in the air in the gap. Unlike the conventional technique in which the roller and the heating wire are in contact with each other, the temperature does not rise only in the vicinity of the heating wire, and it is possible to prevent uneven temperature on the roller surface.

However, when such a sheath heater is used, there is a new problem that the electric current supplied to the sheath heater may leak into the inside of the roller body.

Specifically, in order to properly carry out the perforating process for the rubber material for tires, it is required to raise the surface temperature of the pricking roller to about 140° C., but as shown in FIG. When the surface temperature of the product reaches 130°C or higher, the heater temperature reaches 400°C or higher. The heating temperature of 400° C. or higher exceeds the insulation limit temperature of the leakage preventing insulating material filled in the heater, and thus does not function as an insulating material. In this case, the heating wire inside the sheathed heater may be electrically connected to the roller body via the metal pipe of the sheathed heater and the support material that supports the sheathed heater to cause a leakage trouble.

Therefore, the present inventor has further studied in order to prevent the occurrence of an electric leakage trouble that occurs when a sheathed heater is used, and arranges an insulator made of an insulating material between the sheathed heater and the support material to reduce the heater temperature. Even when the temperature exceeds the insulation limit temperature of the insulating material, the inventors came to the idea of preventing the current from flowing from the heating wire to the roller body, and completed the present invention.

2. Pricking Roller According to this Embodiment Hereinafter, the pricking roller according to one embodiment of the present invention will be specifically described.

FIG. 1 is a diagram schematically showing a cross-sectional structure of the pricking roller according to the present embodiment, and FIG. 2 is a diagram showing a state in which the pricking roller of FIG. 1 is disassembled. Further, FIG. 3 is a perspective view showing a sheath heater and a supporting material of the pricking roller of FIG. 1, and FIG. 4 is a diagram schematically showing a sectional structure around the supporting material.

(1) Overall Configuration As shown in FIG. 1, in the pricking roller 1 according to the present embodiment, a plurality of sheath heaters 3 are inserted inside a roller body 2. In this embodiment, four sheathed heaters 3 are used (see FIG. 3).

The roller main body 2 is a tubular member, and a plurality of pins 2a are provided on the outer peripheral surface thereof at a predetermined interval. By inserting the pins 2a into a rubber material for tire (not shown), An air vent hole is formed in the rubber material. It is preferable to use a stainless steel cylinder for the roller body 2.

Bearings 9 are attached to both ends of the roller body 2, and the support shaft 6 is inserted into the bearings 9. The pricking roller according to the present embodiment is a so-called free roller in which the roller body 2 that is the outer tube portion rotates around the support shaft 6 by the bearing 9.

The sheathed heater 3 is a rod-shaped heater in which a coil of a heating wire (for example, a nichrome wire) 3a as a heating element is housed inside a metal pipe 3b (see FIG. 4). The inside of the metal pipe 3b of the sheathed heater 3 is filled with an insulator (for example, magnesia) for preventing electric leakage.

Although not shown, the sheath heater 3 in the pricking roller is connected to a control mechanism, and the sheath heater 3 is connected to the sheath heater 3 so that the surface temperature of the roller body 2 is maintained at a set temperature (for example, 140° C.). The supply of electricity is controlled.

The pricking roller according to the present embodiment is characterized by the following two points.

(2) First feature The pricking roller according to the present embodiment supports the sheathing heater 3 so that a gap is formed between the sheathing heater 3 and the inner peripheral surface of the roller body 2. The first feature is that the heat from the sheath heater 3 is transferred to the surface of the roller body 2 by using the air in the gap as a transfer medium.

Specifically, as shown in FIG. 3, the support member 5 is two disk-shaped members having a plurality of through holes, and the support shaft 5 is inserted into the center through hole. The sheathed heater 3 is inserted into and supported by each of the through holes around the support shaft 6.

As shown in FIG. 1, in the present embodiment, five support members 5 having the above-described structure are provided at predetermined intervals along the axial direction of the sheathed heater 3, and the sheathed heater 3 supports each of them. It is inserted inside the roller body 2 while being supported by the material 5.

Thus, by supporting each of the plurality of sheathed heaters 3 with the support member 5, a gap is formed between the sheathed heater 3 and the inner peripheral surface of the roller body 2. In the present embodiment, the heat from the sheath heater 3 is transferred to the surface of the roller body 2 using the air in the gap as a transfer medium. At this time, since the heat from the sheath heater 3 is dispersed while the air is being transmitted, unlike the conventional roller, the roller surface and further the pin 2a are uniformly heated without causing temperature unevenness. be able to.

As a result, when the rubber material for a tire (not shown) is pierced with the pin 2a to provide holes for venting air, the holes can be uniformly provided, so that a rubber material having stable quality can be easily manufactured. ..

(3) Second Feature Next, as a second feature, the pricking roller according to the present embodiment includes an insulator that insulates the sheath heater and the support material.

As shown in FIGS. 3 and 4, the insulator 103 is a ring-shaped member fitted in the through hole of the support member 5, and the sheath heater 3 is inserted into the center hole of the insulator 103. The insulator 103 with the sheathed heater 3 inserted therein is held by being sandwiched between the two support members 5.

The insulator 103 is made of an insulating material (for example, alumina porcelain or ceramic) that does not lose its insulating function even when the sheathed heater 3 is in a severely high temperature state, and the sheathed heater 3 and the supporting member 5 are energized. To prevent that.

In the present embodiment, since the insulating insulator 103 is arranged between the sheath heater 3 and the support member 5 in this manner, the temperature of the sheath heater 3 is controlled by the insulation of the insulator in the metal pipe 3b. Even when the temperature exceeds the limit temperature, current does not flow from the sheath heater 3 to the support member 5, and leakage of electricity into the inside of the roller body 2 is prevented.

(4) Other configurations (a) Parts for earth leakage measures When the sheathed heater 3 is used as in the present embodiment, it is preferable to use parts for earth leakage measures in addition to the insulator 103 described above. .. Specifically, as shown in FIGS. 3 and 4, in order to supply electric power to the heating wire 3 a inside the heater, the electrode portion 106 connected to the power supply cord 11 is attached to the end surface of the sheathed heater 3. However, there is a possibility that the electrode portion 106 and the metal pipe 3b, which is the outer pipe of the sheath heater 3, are energized to cause electric leakage.

To prevent such energization between the electrode portion 106 and the metal pipe 3b of the sheathed heater 3, a ring shape made of an insulating material is formed between both end faces of the sheathed heater 3, that is, between the electrode portion 106 and the metal pipe 3b. It is preferable to arrange the mica washer 101.

The ring-shaped mica washer 101 can insulate the electrode portion 106 and the metal pipe 3b, while energizing the electrode portion 106 and the heating wire 3a of the sheath heater 3.

The mica washer 101 also plays a role of preventing the mica tube 102 from falling out of the sheath heater 3.

(B) Number and Arrangement of Sheath Heaters In the above-described embodiment, four sheath heaters 3 are used as shown in FIG. 3, but the number of sheath heaters is not particularly limited and may be one. .. However, in consideration of heating efficiency and the like, it is preferable to use a plurality of sheath heaters.

When using a plurality of sheathed heaters, it is preferable that the sheathed heaters are arranged at equal intervals in the circumferential direction. As a result, the surface of the roller body can be heated more uniformly and the temperature unevenness on the roller surface can be more appropriately prevented.

Although the present invention has been described above based on the embodiment, the present invention is not limited to the above embodiment. Various modifications can be made to the above-described embodiment within the same and equivalent scope as the present invention.

1 Pricking Roller 2 Roller Main Body 2a Pin 3 Sheath Heater 3a Heating Wire 3b Metal Pipe 5 Support 6 Support Shaft 9 Bearing 11 Power Cord 101 Mica Washer 102 Mica Tube 103 Insulator 106 Electrode Part

Claims (6)

A pricking roller provided with a plurality of pins on the surface of a cylindrical roller body,
A sheath heater inserted inside the roller body,
A single or a plurality of through holes for inserting the sheath heater are provided so that a gap is formed between the sheath heater and the inner peripheral surface of the roller body, and the sheath heater is inserted through the through hole. A support material that supports in a state,
An insulating insulator disposed between the sheath heater and the support material is provided,
As a transfer medium air in the gap between the sheath heater and the inner peripheral surface of the roller body, it is configured to transfer the heat from the sheath heater to the surface of the roller body ,
The insulator is a ring-shaped insulator,
Furthermore, the sheathed heater is configured by housing a heating wire inside a metal pipe,
An insulating mica washer is provided between the end surface of the metal pipe and the electrode portion that supplies power to the heating wire.
A pricking roller characterized in that the mica washer is a ring-shaped mica washer. The pricking roller according to claim 1, wherein a plurality of the sheath heaters are arranged inside the roller body. The pricking roller according to claim 2, wherein the number of the sheath heaters is four. The pricking roller according to claim 2 or 3, wherein the sheath heaters are arranged at equal intervals in the circumferential direction. The pricking roller according to any one of claims 1 to 4, wherein the insulator is made of porcelain or ceramics. The pricking roller according to claim 1, wherein the roller body is made of stainless steel.

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