JPH04154073A - Heater block - Google Patents

Abstract

PURPOSE:To prevent a break and extending/contracting deformation by press- hardening fine ceramics to mold a base unit, providing an mounting groove sunk in parallel to a heating surface of the base unit, and fixing a heating wire buried in the mounting groove. CONSTITUTION:Spirally molded heating wires 5 are fixedly buried in a plurality of mounting grooves 4 provided sunk in parallel to a heating surface of a base unit 3 molded by press-hardening fine ceramics in cubical shape, and a heater main unit 2, whose external surface excepting the heating surface of the base unit 3 is coated with a heat insulating material 8, is provided. A cover 10, in which the heater main unit 2 is stored and mounted in a stationary state in a condition that a total area of the heating surface is exposed to protrusively provide a holder piece 13 for mounting to an external surface, is provided. Thickness of the base unit 3 in an opposite side to the heating surface is set to a value larger than a depth of the mounting groove 4 relating to the heating unit 5. In this way, thermal deformation of the heater main unit 1 of burying the heating unit 5 is prevented while maintaining high heating efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a heater block used as a heating source for a heating device, and more specifically, to a structure of a heater block that heats an object using radiant heat. It is something.

[Conventional technology]

Heating devices are used to achieve softening for secondary processing or melting for melting of synthetic resin products.

Conventionally known heating elements used in heating devices for heating synthetic resin products include bobbin heaters, sheathed heaters, quartz tube heaters, and the like.

A bobbin heater is a small heating element with a high heat capacity, which is constructed by wrapping a heating wire heater around a bobbin (straight core material) in a uniform manner.
Generally, one wire is installed directly above the object to be heated and perpendicular to the radiation angle of the copper wire, and is used in combination with a heat-reflecting member.

A sheathed heater is a heating element that has a heating wire formed into a spiral shape and inserted into a vibrator, which is fixed by filling the vibrator with an insulating material, and is configured in the shape of a vibrator that can be curved. A predetermined radius (large and small 2) is placed above the heating element.
They are used in combination with a heat-retaining and reflective member.

The principle of quartz tube heaters is almost the same as that of sheathed heaters, but the difference is that the exterior of sheathed heaters is metal, whereas the exterior of quartz tube heaters is a vibrator made of quartz glass, resulting in better thermal efficiency. , you can easily obtain a high-temperature heat source.

[Problem to be solved by the invention]

In the case of a bobbin heater, a predetermined amount of heat is uniformly applied over the entire length of the object to be heated by the drop in heat generation at both ends of the bobbin heater that occurs when the full load of the power source is not applied to each bobbin heater that is divided and arranged on a set straight line. The heating wire is exposed directly to the outside air, resulting in severe deterioration due to oxidation; and the heating wire is subject to gas deterioration due to self-generated defective gas when the object to be heated softens.
Since the heating wires are exposed, there is a lot of heat dissipation in all directions, which causes poor energy efficiency.Moreover, the assembly is simply fixed by inserting pins etc. into both ends of the perforated bobbin. , the mounting strength is insufficient, and
There are problems with installation, such as unstable posture.

In the case of sheathed heaters, bending is performed under hot conditions, but due to repeated cycles between room temperature and high temperature, it becomes impossible to maintain a constant curved curvature.
Particularly when the object to be heated is thin, it is sensitive to thermal effects, so due to the change in the curvature of the sheathed heater as an opposing heating source, the opposing positional relationship between the object to be heated and the center of the sheathed heater The sheathed heater itself expands and contracts due to temperature changes, so at least one side of the sheathed heater must be held so that it can slide freely to follow this expansion and contraction, or it must be held with a fixture. It is necessary to provide a flexible function to the sheathed heater, and it is extremely difficult to secure an installation location.Even if the sheathed heater can be installed, the sheathed heater itself will soften due to heat generation, stretch under its own weight, and loosen downward. If the deformation is significant, there is a risk of grounding or mechanical damage.Although the deformation of the sheathed heater may stabilize after long-term use, mechanical and electrical adjustments must be made until the deformation stabilizes. Even if it is possible to use the sheathed heater, if it becomes necessary to replace the sheathed heater due to damage or deterioration, the sheathed heater will not be compatible, and the longer the sheathed heater, the more the expansion and contraction deformation will occur. (If you divide it into appropriate lengths, you will need to curve the end into an L-shape with the smallest possible radius of curvature to secure the terminal.)
Considering the prevention of disconnection of the heating wire, the minimum bending radius of the pipe material is 2.5 to 3.0 times the pipe diameter. Therefore, the space between adjacent sheathed heaters becomes a blind spot in heating, resulting in the inconvenience of uneven heating and interruption of heating. In addition, a large number of sheathed heater supports and irradiation heat reflecting plates are required, resulting in an increase in the size of the device.

Furthermore, in the case of quartz tube heaters, they have the same problems as the sheathed heaters mentioned above, are easily damaged by shocks and vibrations that occur in the equipment to which they are attached, and expand and contract depending on the temperature, but the support terminals are made of ceramics. Since the quartz heater is made of wood and the expansion/contraction deformation part is made of glass, it is extremely difficult to firmly support the quartz heater and maintain its shape (maintain the curved shape, prevent it from loosening downward due to its own weight), etc. There is a point.

Therefore, the present invention has been devised to solve the above-mentioned problems in the conventional technology.It almost eliminates the expansion and contraction deformation of the heater block as a whole due to temperature, and also uses the heat generated from the heating wire to heat the object to be heated. The technical challenge is to achieve an effective, strong and stable installation, which allows the object to be heated to be heated accurately, stably and with high efficiency, and which is convenient to handle and has excellent compatibility. The purpose is to obtain.

[Means to solve the problem]

The means of the present invention to solve the above technical problem is to compact fine ceramics such as silica or alumina molded into fibers into a desired three-dimensional shape to form a base body, and to form a base body in parallel with the heat generating surface of this base body. For multiple recessed assemblies, a heating wire formed in a spiral shape is embedded and fixed in the groove, and the heater main body is covered with a heat insulating material on the outer surface of the base body except for the heat generating surface. , be fixedly housed and assembled with the entire heating surface exposed, and have a cover with a holder piece protruding from the outside surface for attachment, and be opened to the heating element and opposite to the heating surface of the heater body. When installing, set the thickness of the side base body to a value greater than the depth of the groove.

In order to increase the ability to maintain the mechanical appearance shape of the heater body,
For assembly, it is preferable that a surface coating layer is formed over the entire surface of the base body, in which the heating wire is embedded and fixed in the groove, and then hardened.

The heater body is not limited in its external shape;
The base body is molded into a horizontally long three-dimensional shape, and when multiple assemblies are assembled on one flat surface with a large vertical width, the exterior shape is such that grooves are laid horizontally in parallel, or the base body is formed with semicircular grooves on the lower surface of the horizontally long solid body. It is molded into a shape that is recessed in the horizontal direction, and when multiple assemblies are installed on this semicircular groove surface, the external shape is such that the grooves are horizontally installed in parallel, and the external shape is that the base body is molded into a rectangular parallelepiped shape that is curved at a constant curvature. It is best to set it according to the purpose and conditions of use of the heater block.

[Effect]

The base body, which holds the heating wire in a fixed position, is made by compacting fiber-shaped fine ceramics such as silica or alumina into the desired three-dimensional shape. It can be set relatively freely, and at the same time as the entire compaction is formed, the groove is formed into a desired shape during assembly.

The assembly is achieved by embedding and fixing the heating wire in the groove using cement made from ceramic powder, which is the same material as the fine ceramics that is the molding material for the base body.

Cement made from this ceramic powder solidifies in a relatively soft state, so when the heating wire undergoes expansion/contraction deformation, it will be pushed by the expanded/contracted heating wire, and will be pushed by the amount of expansion/contraction deformation that occurs around the heating wire. However, since the heating wire is formed in a spiral shape,
The expansion and contraction deformation that occurs in the heating wire results in an increase or decrease in the diameter of the coil, and therefore, all of the expansion and contraction deformation that occurs in the heating wire is absorbed within the groove during assembly. In addition, since the cement made from ceramic powder is mainly composed of the same material as the molding material of the base body, it has a strong adhesive force to the base body, and therefore the heating wire is assembled into the groove. achieve and maintain strong retention.

The surface coating layer is formed by coating fine ceramic powder materials such as silica and alumina dissolved in cement made from ceramic powder, and coats the surface of the base body, which is simply pressed fiber-like fine ceramics. It is hardened to make its physical properties stable, and is coated and molded onto the entire surface of the base body to which the heating wire is assembled.

The surface coating layer certainly solidifies the surface of the base body and stabilizes the physical form of the surface of the base body, but its hardness is not necessarily sufficient and it is brittle, so it cannot be used as it is. Easily damaged by contact with other objects. The heat insulating material, which is assembled to the base body by covering the outer surface of the base body excluding the heat generating surface where the heat generating wire is arranged, protects the mechanically fragile base body from external impact forces. This is to increase the insulation effect between the heater body, which is composed of a base body and a heat insulating material, and the cover that attaches the heater body to a predetermined location. It has a very low thermal conductivity and is hard enough to exhibit moderate wear resistance.

The cover is used to securely and stably attach the heater body to a predetermined location.The cover is designed to securely and securely mount the heater body in a predetermined location.
It is fixed in place using screws or other means, and is manufactured from a highly heat-resistant metal material such as stainless steel.

Since the heating wire is buried inside the base body, the heat from this heating wire is transmitted through the base body and radiated from the surface of the base body, but the heating wire is buried inside the base body with bias towards the heating surface. Therefore, the heat from the heating wire is radiated from the heating surface more quickly. In addition, the heating wires are buried in the base body with a bias toward the heating surface, but the degree of this bias is such that the thickness of the base body on the side opposite to the heating surface is larger than the depth of the groove when assembled. Therefore, the heat transferred from this heating wire in a direction other than the heating surface will only heat the vicinity of this heating wire, and a large amount of heat will not be transferred to the surface of the base body other than the heating surface. Therefore, most of the heat from the heating wire is radiated from the heating surface. In other words, since the base body is made of fine ceramics molded into fibers that have high heat resistance and extremely low thermal conductivity, during the initial operation of the heating wire,
The area around this heating wire is heated uniformly, but the spread rate of the area of the base body heated by this heating wire is slow, and the area heated to a temperature almost equal to the heating temperature of the heating wire gradually spreads around the heating wire. It will spread evenly. For this reason, the heating part of the base body that gradually spreads has a heating line that is biased toward the heating surface, so it reaches the heating surface first, and releases heat from this heating surface to the outside of the base body by radiation. do. In this way, when heat starts to be released from the heat generating surface, almost all of the heat from the heat generating wire is prevented from being transmitted in directions other than the heat generating surface due to its high heat. It is released from.

Even though the entire heater body is made of a material with extremely low thermal conductivity, this does not mean that the cover will not be heated at all by the heat from the heating wire; the cover will also be heated to some degree when the heating wire is in operation. become. Since the cover is made of metal, it expands and deforms due to this heating.
Since the heater body hardly deforms, sliding displacement occurs between the contact surfaces of the heater body and the cover. However, since the contact surface of the heater body with the cover is formed of a heat insulating material molded with sufficiently high hardness, this heat insulating material acts as a mechanical protection material between the heater body and the cover. To reliably prevent damage to the heater body due to sliding displacement that occurs during In addition, when assembling the heater body to the cover, the cover hugs the entire heater body, rather than fixing it at multiple locations with screws, etc. Therefore, if the cover expands and deforms due to heat, the heater body is Even if the grip of the cover loosens, no tightening force is generated from the cover to the heater body.

The heating wire is buried inside the heater body, and the heating surface of the heater body heated by the heating wire becomes a heating source for the object to be heated, so even though the heater body uses multiple heating wires, First, a substantially planar heating source is formed for the object to be heated.

In addition, the heating wire is embedded and fixed inside the base body of fine ceramics 9m, and the way the heating wire is buried and fixed inside the base body is such that it can freely expand and contract due to the heating of the heating wire inside the base body. This is achieved by preventing the heater body from expanding or contracting due to the heat of the heating wire, or from softening and sagging downward due to its own weight, and the heater body always maintains a constant shape.

Furthermore, since the heating wire is buried and fixed within the heater body, it does not come into contact with the outside air, so there is no deterioration due to oxidation or corrosive gas generated from the heated object during heating, so it can last for a long time. Demonstrates stable heating operation over a long period of time.

Although the heating wire is formed into a spiral shape, it is a normal nichrome wire, so when drawing out the wire as a terminal, the heating wire must be laid along the entire length of the heater body, and the end edge of the heater body must be pulled out. As a result, when a plurality of heater blocks are connected in series, there will be no heating non-operating area at the heater block connection portion.

The cover that attaches the heater body to a predetermined position in a predetermined posture holds the heater body in a manner that envelops the heater body, so it is easy to attach and remove the heater body from the cover. It is possible to replace only the heater main body with respect to the cover attached to the heater block, and thereby only the heater main body can be replaced without disassembling the heating device constructed by combining a large number of heater blocks.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

In the illustrated embodiment, four grooves 4 are recessed horizontally in parallel on the outer surface, which is the heat generating surface side, of the base body 3 formed in three dimensions.
In this assembly, a heating wire 5 formed into a spiral shape with a coil winding outer diameter regulated within 10 times the wire diameter is embedded and fixed by a fixing member 6 in a groove 4.

When assembling, the heating wire 5 buried and fixed in the groove 4 is attached to the base body 3.
However, the greater the bias of the buried position of the heating wire 5 toward the heating surface side, the more effectively the heat from the heating wire 5 can be radiated to the heated object K. You will be able to do so.

However, increasing the deviation of the heating wires 5 means increasing the thickness of the base body 3 itself, consuming a large amount of material to manufacture one base body 3, and increasing the manufacturing cost. Therefore, in practice, the thickness from the heating wire 5 to the surface of the base body 3 opposite to the heating surface should be approximately three times the thickness from the heating wire 5 to the heating surface of the base body 30. suitable.

For assembly, use the fixing material 6 in the groove 4 to generate heat I! A surface coating layer 7 is formed over the entire surface of the base body 30 in which the base body 30 is embedded and fixed. Since it is individually molded, the inner part is the base body 3.
It becomes individualized in a state in which it penetrates into the interior, and is thereby strongly bonded to the base body 3.

The heat insulating material 8 is assembled to cover the outer surface of the base body 3 coated with the surface coating layer 7 other than the heat generating surface. 9 is assembled in a fixed state to the heat insulating material 8.

A cover 10 made of stainless steel that houses and holds the heater body 2 has a hollow rectangular parallelepiped shape with one side open, into which the heater body 2 can be loosely inserted, and has a heat insulating material. A cover piece 11 having an angular cross-section and abutting on the piece 9 is detachably assembled with a set screw 12.

This cover piece 11 is attached to the heater body 2 with respect to the cover lO.
This cover piece 1 holds the insertion and assembly of
The heat insulating material piece 9 is provided so that the heat insulating material piece 9 does not come into direct contact with the surface of the base body 3 and damage the surface of the base body 3.

A holder piece 13 is integrally protruded and stepped over the entire length of the cover 10 at a suitable location on the outer surface of the cover 10, and the heater block 1 can be attached to a predetermined location using this holder piece 13.

When attaching the heater block 1 to a predetermined location using this holder piece 13, the cover 10 expands and deforms due to the heat generated by the heat generating wire 5, so the cover 10 flexibly absorbs the expansion and contraction deformation due to the heat generated. In order to prevent the heater block 1 from being installed in a defective manner, the mounting holes 14 formed in the holder piece 13 are elongated holes that are elongated along the length of the heater block 1. It becomes.

In the embodiment shown in FIGS. 1 to 4, the heater body 2 has a horizontally elongated rectangular parallelepiped shape, and one flat outer surface with a large height and width is used as a heat generating surface, and the heat generating surface provided on this heat generating surface is The lines 5 are laid horizontally in parallel at intervals of 400 mm.

Fifth! ! 1 shows an example of the configuration of a heating device configured by combining a plurality of heater blocks 1 having the configurations shown in FIGS. 1 to 4. A pair of heater blocks 1 connected in series are connected at regular intervals. The heater blocks are arranged immovably with their heat-generating surfaces facing each other, and an object K to be heated such as a synthetic resin product molded into a cylindrical shape is rotated at a constant speed in a desired direction by a conveyor H at an intermediate position between both groups of heater blocks. By moving the object while moving, the entire object to be heated is uniformly heated to a desired temperature. In addition, in FIG. 5, the outer wall of the heating device is not shown.

Figures 6 to 8! ! In the embodiment shown in I, the base body 3 is formed into a shape in which a semicircular groove is recessed over the entire length at the center of the lower surface of a rectangular parallelepiped that is curved with a constant curvature in the horizontal plane, and the groove surface of the semicircular groove is formed. Four heat-generating wires 5 are buried and fixed in parallel along the length direction at equal intervals, and this semicircular groove surface is used as a heat-generating surface.

Therefore, in the embodiments shown in FIGS. 6 to 8, the radiant heat from the heating surface is concentrated at the center of this semicircular groove-shaped heating surface, and it is possible to This is optimal for intensively heating a location, and since the heating space is formed by the heater block 1 itself, the entire heating device becomes extremely compact.

FIG. 9 shows an example of the configuration of a heating device in which a plurality of heater blocks 1 having the configurations shown in FIGS. 6 to 8 are arranged in series. The heating surface forms an arc-shaped heating space with a constant curvature, and the carrier H is a pair of vices attached to a turntable. A tube guide H1 is attached to each of the pair of vises that are the conveying body H, and the open end of the tube that is the object to be heated is flattened and protruded upward from both sides. The tube is held between vices, and the open end of the tube that protrudes upward is positioned at the center of the heating space formed by the heater block 1.

〔Effect of the invention〕

Since the present invention has the above-described configuration, it has the following effects.

The heating wire, which is the heat source, is buried in the fine ceramic material, so there is no deterioration due to oxidation due to contact with outside air or gasification due to contact with gas generated from the heated object, and it is reliable and stable over a long period of time. Demonstrates excellent heating operation.

The heat generated from the buried heating wire is not radiated in all directions, but is radiated only from a fixed heating surface, which is energy efficient and does not require a reflector.
There is no problem of a decrease in heating efficiency due to deterioration of the reflection efficiency of the reflector, and as a result, high heating efficiency can be maintained for a long period of time, and since the reflector is not required, the entire heating device can be used efficiently. It can be downsized to

The heater body in which the heating element is buried will not be deformed due to heat.
This heater body is assembled in a manner that it is enclosed within a metal cover, and the installation is achieved using this cover with high mechanical strength, so that the installation strength can be sufficiently increased, and the installation can be done in a stable position. It can be done.

Since the mechanically fragile heater body is surrounded by a metal cover, it can exhibit sufficiently high durability against external impacts.

When a heating device is configured by arranging a plurality of heater blocks in series, the missing area of the heat generating portion at each heater block connection portion is extremely small, so that uniform heating of the object to be heated is hardly deteriorated.

When a heating device is constructed by combining a plurality of heater blocks, the heater bodies of each heater block do not undergo thermal deformation, so it is possible to replace the heater bodies of individual heater blocks, and the replacement work is extremely easy. This makes it possible to maintain the heating device well and is economical.

[Brief explanation of drawings]

Figures 1 to 4 show the structure of an embodiment of the heater block according to the present invention, with Figure 1 being a front view, Figure 2 being a plan view, Figure 3 being a side view, and Figure 4 being a side view. is an enlarged vertical side view. FIG. 5 is a partial perspective view showing an example of a heating device constructed using the embodiment shown in FIGS. 1 to 4. FIG. 6 to 8 show the structure of other embodiments of the heater block according to the present invention, in which FIG. 6 is a plan view and FIG.
The figure is a front view, and FIG. 8 is an enlarged longitudinal sectional side view. FIG. 9 is a partial perspective view showing an example of a heating device constructed using the embodiment shown in FIGS. 6 to 8. FIG. Explanation of symbols 1; heater block; 2; heater body; 3; base body;
4; Assembly groove, 5; Heat generating wire, 6; Fixing material, 7; Surface coating layer, 8; Insulating material, 9; Insulating material piece, 10; Cover, 11; Cover piece, 12; Fixing bolt, 13; Holder piece, 14; mounting hole, H; carrier, Hl; tube guide, K: object to be heated.

Claims (6)

[Claims] (1) A base body (3) is formed by compacting fine ceramics such as silica or alumina formed into a fiber shape into a desired three-dimensional shape, and the base body (3) is recessed in parallel to the heat generating surface of the base body (3). A heater body in which spirally shaped heating wires (5) are buried and fixed in a plurality of assembly grooves (4), and the outer surface of the base body (3) except for the heating surface is covered with a heat insulating material (8). (2), the heater body (2) is immovably housed and assembled with the entire heat generating surface exposed, and a cover (2) with a holder piece (13) protruding from the outer surface for attachment
10), and the thickness of the base body (3) on the side opposite to the heat generating surface opened to the heat generating element (5) is set to a value larger than the depth of the assembly groove (4). A heater block made up of (2) A surface coating layer (7
) The heater block according to claim 1, wherein the heater block is coated and cured. (3) The base body (3) is formed into a horizontally elongated three-dimensional shape, and a plurality of assembly grooves (4) are formed on one flat surface with a large vertical width.
The heater block according to claim 1 or 2, wherein the heater block is arranged horizontally in parallel. (4) The base body (3) is formed into a shape in which a semicircular groove is recessed in the horizontal direction on the lower surface of the oblong solid body, and a plurality of assembly grooves (4) are horizontally formed in parallel on the semicircular groove surface. Claim 1 or 2
Heater block as described in. (5) The heater block according to claim 3 or 4, wherein the base body (3) is formed into a rectangular parallelepiped shape. (6) The heater block according to claim 3 or 4, wherein the base body (3) is formed into a rectangular parallelepiped shape curved with a constant curvature.