JPS6236234Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a band heater that is used for heating cylindrical parts such as mold heating and cylinder heating, and is attached by a tightening band.

As is well known, a band heater is attached to an object to be heated using a tightening band. However, in conventional band heaters in which the heater and the tightening band are not integrated into one, the heater is attached to the There was a risk that the tightening band having the elongated hole for pulling out the electric terminal would be misaligned on the circumferential surface of the heater and come into contact with the terminal at the edge of the elongated hole, causing a short circuit accident. Therefore, a band heater is also provided in which the heater and the tightening band are locked and integrated to prevent displacement in the circumferential direction.

For example, some heaters have tightening bands riveted to both widthwise ends of the heater using rivets or the like, but in this method the heating wire that is wound around the insulating plate avoids the riveted parts. Because the need arises,
There was a problem in that the heat generating area of the heater in this portion decreased, and the temperature distribution of the heater in the circumferential direction became non-uniform, causing temperature unevenness. Furthermore, since this method usually involves localized impact when riveting, dents and damage occur on the contact surface with the object to be heated, which impairs the smoothness and causes poor contact.
There was also a risk of overheating and breaking the wire.

Another method is to provide a locking member protruding from the top surface of the heater, provide a hole for the locking member in the tightening band, and insert the locking member into the hole to integrate the locking member. However, this method eliminates all the drawbacks of the above-mentioned riveting method, but since the tightening band is completely fixed and integrated at the locking part, it is independent from the heater. Compared to a tightening band that is in a free state, it is difficult to tighten it, and there is a problem that a good tightening state cannot be obtained for the object to be heated. Furthermore, the tightening band repeats thermal expansion and contraction due to the heat cycle that accompanies use, and loosens due to the hysteresis of the thermal expansion, so it is necessary to retighten it periodically to correct it. A band heater that is completely locked and integrated with the band also has the disadvantage that the above-mentioned additional tightening correction cannot be performed effectively.

Therefore, the purpose of this invention is to have an even temperature distribution without reducing the heating area of the heater, avoid damage caused by processing, and ensure a good tightening condition. Furthermore, it is an object of the present invention to provide a band heater in which a tightening band and a heater are integrated, which can effectively carry out retightening correction.

In order to achieve the above object, in this invention, a locking member is provided protruding from the upper surface of the exterior metal body, and an elongated hole through which the locking member can be inserted is provided to protrude in the circumferential direction on the tightening band. This is designed to integrate the tightening band, and in particular, the tightening band is not completely fixed to the heater as in the past, but is movable in the circumferential direction within the range of the elongated hole mentioned above. A fixed band heater is provided.

Specific embodiments will be described below with reference to the drawings.

Reference numeral 1 denotes an exterior metal body, which is composed of a case 1a and a top plate 1b.Inside this exterior metal body 1, there is an insulating core plate 3 around which a heating wire 2 is wound, and the upper and lower surfaces of this core plate 3 are covered. Insulating plates 4, 4 coated with insulation are installed inside. Reference numeral 5 denotes a locking member made of a U-shaped metal plate, which is protruded from the top plate 1b by means such as welding. In order to fix and protrude the locking member by welding, it is preferable to use a welding method using a capacitor spot welder, since there is no fear of adverse effects on the internal components of the heater. In addition, as another fixation/protrusion method that does not employ welding, for example, the locking member is approximately U as shown in this example.
If it is shaped like a letter, as shown in Fig. 2, a through hole 6 is provided in advance in the top plate 1b, and recesses 7, 7' into which the end of the locking member 5 can be fitted are formed by pressure molding from the inner surface. It may be fixed.

Reference numeral 8 denotes a tightening band for attaching the heater, which has an elongated hole 9 in the circumferential direction of the tightening band into which the locking member is inserted, and the locking member 5 is inserted into the elongated hole 9. As shown in the figure, the heater and the tightening band are integrally locked together while ensuring movement in the circumferential direction within the range of this elongated hole by spreading molding in the width direction of the heater. .

It goes without saying that the elongated hole 9 should be so elongated that the tightening band does not come into contact with the terminals of the heater when the tightening band moves in the circumferential direction of the heater.

Furthermore, the locking member 5 is not limited to the above-mentioned substantially U-shaped member, but may be a claw-like member obtained by dividing the substantially U-shaped member at the top, as shown in FIG. 3, for example. It is easy to bend the heater in the width direction. Alternatively, a locking member having a hole through which a fastener such as a cotter pin can be inserted may be provided protruding from the top plate, and the fastening band and heater may be integrated by the fastener.

In short, a long hole in the circumferential direction is drilled in the tightening band,
What is necessary is to provide a locking member that can be fitted into and locked in this elongated hole and protrudes from the upper surface of the exterior metal body.

As described above, the band heater according to this invention achieves integration of the heater and the tightening band by inserting and locking the locking member protruding from the upper surface of the exterior metal body into the elongated hole of the tightening band. Therefore, unlike the case of riveting, there is no need to specially form a cutout in the insulating plate for inserting the rivet, or to remove the riveted part and wrap the heating wire. Of course, it is possible to obtain a heat distribution state, and since there is no need to apply impact force during processing, as with riveting, there is no dent or damage to the contact surface with the heated object, resulting in a good process. Since the contact state can be maintained, it is possible to completely prevent the occurrence of overheating and disconnection accidents due to poor contact of the heating wire. In addition, since the integrated locking band is movable in the circumferential direction within the range of the long hole, unlike the conventional example in which the band heater is integrated in a non-movable state, when attaching the band heater to the object to be heated, This has the advantage that the tightening band slides on the surface of the heater, and tightening can be performed very easily and reliably, resulting in a good tightening condition and, ultimately, a good contact condition with the surface to be heated. In addition, even when the tightening band loosens due to heat cycles, etc., retightening can be effectively corrected, and good adhesion to the heated object can always be ensured, so it can be used for a long period of time. It is also possible to effectively prevent overheating and disconnection accidents when using this method. Furthermore, since the locking member is inserted and locked into an elongated hole with a certain tolerance, precise and complicated positioning is not necessary and only simple machining is required, making it inexpensive and marketable. It can be supplied to Furthermore, the present invention provides a band heater that can be easily applied to existing band heaters in which the heater and the tightening band are not integrated by post-processing, and has extremely high practical value.

There are two types of band heaters: the so-called one-piece type as shown in Figure 1, and the so-called two-piece type, which is divided into two pieces, but it goes without saying that this idea can be applied to both. .

[Brief explanation of the drawing]

FIGS. 1A to 1C are perspective views showing one embodiment of the band heater according to this invention according to the processing procedure;
FIG. 2 is a sectional view of a main part showing another example of a method of attaching a locking member, and FIG. 3 is a perspective view of a band heater using another locking member. 1... Exterior metal body, 2... Heating wire, 3... Insulating core plate, 4, 4... Insulating plate, 5... Locking member, 8
...Tightening band, 9...Elongated hole.

Claims (1)

[Scope of utility model registration request] In a band heater in which a heating wire is wound around an insulating core plate, at least the upper and lower surfaces thereof are covered with insulating plates, and the band heater is housed in an exterior metal body, a locking member is provided protruding from the upper surface of the exterior metal body, and the Insert and lock the locking member into the long hole drilled in the tightening band for attaching the heater.
A band heater characterized in that a tightening band and a heater are integrated by maintaining a movable state in the circumferential direction within the range of the elongated hole.