JPH0226155Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement of a plate-shaped infrared heater used as a heat source for various industrial heaters, dryers, space heaters, etc.

(Prior Art) As a heat source for various industrial heaters, dryers, room heaters, etc., infrared heaters in which coiled resistance heating elements are attached to meandering grooves provided on ceramic plates are widely used. This type of infrared heater usually has a semicircular end portion of the boundary wall provided between the straight portions of the meandering grooves. (For example, in 1987-
(No. 26194) However, when the end of the boundary wall is semicircular in this way, when the coiled resistance heating element is installed in the meandering groove, the inside of the bent part of the coiled resistance heating element is attached to the end of the boundary wall. Because it is difficult to engage closely and the spring back force is weak, the coiled resistance heating element floats up at the bend, making it difficult to attach it to the meandering groove, and depending on how it is installed, the coils on the inside of the bend may There was a problem in that the batteries were placed in close contact with each other, causing local temperature rise during use with electricity, resulting in thermal damage.

Furthermore, as shown in Japanese Patent Application Laid-Open No. 60-246582, an infrared heater is known in which a heating wire is locked inside a groove with an inverted Ω-shaped cross section using the springback effect, but the manufacturing process is slow. In addition to being complicated, there were problems in that the heating wire was easily deteriorated by oxidation during use.

(Problems that the invention attempts to solve) This invention solves these conventional problems,
This was completed to provide a plate-shaped infrared heater that is easy to manufacture and has a long life.

(Means for Solving the Problems) The present invention, which was devised to solve the above-mentioned conventional problems, is an infrared ray heating element in which a coiled resistance heating element is attached to a meandering groove with a corrugated cross section provided on a ceramic plate. In the heater, both corners of the end of the boundary wall provided between the straight parts of the meandering groove are formed into substantially right angle parts, and the inside of the bent part of the coiled resistance heating element is closely engaged with the end. In addition to holding the coiled resistance heating element by the springback effect, the coiled resistance heating element is embedded inside the meandering groove with a heat-resistant filler, and ball-shaped locking ends are formed at both ends of the coiled resistance heating element to secure these engagements. It is characterized in that the toe portion is locked to the intermediate narrowed portion of the rectilinear portion located approximately in the center of the ceramic plate body.

(Function) The device configured in this way can be used in various industrial heaters, driers, space heaters, etc., as well as conventional infrared heaters of this type in which coiled resistance heating elements are attached to meandering grooves provided on a ceramic plate. It can be used by attaching it to a frame such as, etc., and connecting the lead wire connected to the coiled resistance heating element to a power source.

(Example) Next, to explain the present invention in detail with reference to the illustrated example, 1 in the figure shows a heat-resistant material obtained by press-molding cordierite-based raw material powder in a mold and sintering the molded base. , approximately 2mm thick with excellent thermal shock resistance
The ceramic plate 1 has meandering grooves 3 for mounting a heating element on its non-radiation surface side, and bent portions such that an appropriate number of parallel straight portions 3a are formed. 3b, the thickness of each part is substantially uniform, and the cross section is corrugated and has an uneven surface 2. And each straight section 3a,
The boundary wall 4 provided between the ends 3a has substantially right-angled portions 4b, 4b at both corners of its end portion 4a, and the outer edge of the bent portion 3b is semicircular. Incidentally, the substantially right-angled portion 4b may be slightly rounded by about 0.5R to 1R to prevent cracking. Further, a straight portion 3a located approximately in the center of the ceramic plate 1
An intermediate narrow portion 5, 5 is formed by bulging out the opposing positions of the boundary walls 4, 4. Reference numeral 6 denotes a coiled resistance heating element such as a nichrome wire installed in the meandering groove 3, and the base ends of heat-resistant metal stranded wires are twisted together and welded at the ends to form a lead wire 8 at both ends of the coiled resistance heating element. The welded portions at both ends are formed into ball-shaped locking end portions 7, and the locking ends 7, 7 are locked to the intermediate narrow portions 5, 5. The ceramic plate 1 may have a completely flat shape or may have a gently curved shape. Then, the coiled resistance heating element 6 is attached to the inside of the meandering groove 3 while applying tension, and the coiled resistance heating element 6 is provided with the substantially right-angled portions 4b, 4b of the boundary wall 4 due to the springback effect. The end portion 4a is closely engaged with the inside of the bent portion. In addition, the coiled resistance heating element 6 is made of a ceramic plate 1.
It is preferable to adjust the amount of heat generated by making the coil pitch larger at the center than at the outer periphery to prevent local heating due to thermal interference in the center.Furthermore, the width of the boundary wall 4 is also set so that the center is wider than the outer periphery. It is also possible to make the temperature uniform on the radiation surface by widening it. In addition, after the coiled resistance heating element 6 is installed in the meandering groove 3, a material such as a colloidal silica-based embedding material mixed with a sodium silicate-based or aluminum phosphate-based adhesive is placed inside the meandering groove 3. A heat-resistant filler 9 that hardens at room temperature is embedded to prevent the coiled resistance heating element 6 from being oxidized and deteriorated due to contact with outside air.

(Effect of the invention) Such an infrared heater is made of ceramic plate 1.
Since both corners of the end portion 4a of the boundary wall 4 provided between the rectilinear portions 3a, 3a of the meandering concave line 3 provided in the meandering groove 3 are formed into substantially right angle portions 4b, 4b, the locking ends at both ends The coiled resistance heating element 6, which is fixed by locking the members 7, 7 to the intermediate constricted parts 5, 5 of the straight section 3a, has an approximately right angle on the inside of the bent part even if the meandering groove 3 is complex. It is closely engaged with the end portion 4a having the shaped portions 4b, 4b by a strong spring back effect, and can be easily and accurately installed and held in the meandering groove 3 without using a special insertion jig. It will be done. Moreover, in the bent portion 3b of the meandering groove 3, the inner side of the bent portion of the coiled resistance heating element 6 is branched about the substantially right angle portions 4b, 4b of the end portion 4a of the boundary wall 4, so that the coil at the bent portion The space is expanded,
Unlike when the end of the boundary wall is semicircular, the coils do not come into close contact with each other inside the bent portion, and there is no risk of local temperature rise and thermal damage during energized use. In addition, a coiled resistance heating element 6
The ends of the lead wires 8, 8 are welded to both ends to form ball-shaped locking ends 7, 7, and these locking ends 7, 7 are connected to the linear portion 3 located approximately in the center of the ceramic plate 1.
Since the lead wires 8, 8 can be easily led out through the insulating collar for attaching the heater provided approximately at the center of the non-radiation surface side, the lead wires 8, 8 can be easily led out, making it possible to reduce the wall thickness and weight. This simplifies the wiring assembly work, and since the central portion of the ceramic plate 1, which tends to be locally overheated due to thermal interference from the outer periphery, has no heat generation between the intermediate narrow portions 5, 5. The radiation surface can be made uniform without adjusting the coil pitch of the coiled resistance heating element 6 or the width of the boundary wall 4, resulting in a product with a long life and good temperature distribution.

Furthermore, since the coiled resistance heating element 6 is embedded inside the meandering groove 3 with the heat-resistant filler 9, the coiled resistance heating element 6 does not come into contact with the outside air, and its oxidation deterioration can be prevented, and it is possible to Unlike the case where the heating element is locked inside a groove with a complicated cross-sectional shape, it is extremely easy to embed and fix the coiled resistance heating element 6.

Therefore, the present invention has great practical value as it solves the problems of conventional infrared heaters of this kind.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view showing an embodiment of the present invention, Fig. 2 is a partially cutaway front view of the main part, and Fig.
The figure is a partially cutaway perspective view showing the engagement portion between both ends of the coiled resistance heating element and the ceramic plate. 1...Ceramics plate body, 3...Meandering groove, 3
a... Straight section, 4... Boundary wall, 4a... End, 4
b...Substantially right-angled part, 5... Intermediate narrowed part, 6... Coiled resistance heating element, 7... Locking end.

Claims (1)

[Scope of utility model registration request] In an infrared heater in which a coiled resistance heating element 6 is attached to a meandering groove 3 having a wave-shaped cross section provided on a ceramic plate 1, straight portions 3a, 3 of the meandering groove 3 are provided.
Both corners of the end 4a of the boundary wall 4 provided between the spaces 4a and 4b are formed into substantially right-angled parts 4b, and the inside of the bent part of the coiled resistance heating element 6 is tightly engaged with the end 4a to form a spring back. At the same time, the coiled resistance heating element 6 is held by the heat-resistant filler 9 inside the meandering groove 3, and ball-shaped locking ends 7, 7 are formed at both ends of the coiled resistance heating element 6. An infrared heater characterized in that these locking end portions 7, 7 are locked to intermediate narrow portions 5, 5 of a rectilinear portion 3a located approximately at the center of the ceramic plate 1.