JPH0120509Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion device having a burner nozzle.

Figure 1 shows the structure of the tip of a conventional burner nozzle.
Referring to FIG. 3, the back plate 2 and spray plate 3 are brought into close contact with the burner nozzle main body 1, and then assembled by tightening with a threaded cap 4.

To explain in detail the state after assembly until operation, Fig. 3a shows a state in which no stress is applied to the cap 4 during disassembly, and Fig. 3b shows a state in which no stress is applied to the cap 4 during assembly (at room temperature). Fig. 3c shows a state in which the cap 4 is distorted due to the spray plate 3 and the spray plate 2 after assembly.
Indicates operation when the temperature is higher. In the case of FIG. 3c, the distortion is smaller than that of FIG. 3b. Even in this state of thermal expansion, the tightening force must remain, so it is necessary to tighten it sufficiently.

In the past, both the cap 4 and the spray plate 3 were made of steel, so there was no problem even if they were tightened sufficiently, but if the spray plate 3 was made of ceramic in order to extend the life of the spray plate 3, the following problems would occur.

(1) Since the coefficient of thermal expansion of ceramic is smaller than that of steel, the degree of decrease in strain when changing from the state shown in Figure 3b to the state shown in Figure 3c is large, so it is necessary to tighten it more strongly. .

(2) Ceramic is more brittle than steel, so there is a high possibility that it will break in the state shown in Figure 3b.

The present invention was devised in view of the above-mentioned situation, and includes a combustion apparatus of the type in which a back plate and a spray plate are pressed and fixed to the burner nozzle body by a cap screwed onto the burner nozzle body. It is characterized by providing a slit in the center direction and a groove in the circumferential direction formed on the outer surface of the slit in order to relieve stress during press fixation by screwing.

According to the present invention, the rigidity of the cap is reduced, so that even if the spray plate is made of ceramic, it will not break.

The present invention will now be described in detail with reference to preferred embodiments thereof, which are illustrated in the accompanying drawings.

A cap 4 shown in FIG. 4 is used in place of the burner nozzle cap shown in FIGS. 1 to 3. That is, the cap 4 shown in FIG. 4 is screwed onto the burner nozzle body 1, and the back plate 2 and spray plate 3 are pressed against the burner nozzle body 1 (see FIGS. 1 and 2). As shown in FIG. 4, this cap 4 has a female thread 7 inside its rear end, and is screwed into the burner nozzle body 1 by means of this female thread 7. Several short slits 5 are formed in the axial direction at the front end. As shown in the figure, these slits 5 are preferably formed at equal intervals in the circumferential direction, and their length is approximately half the length of the cap in the illustrated example. A circumferential groove 6 is also formed on the outer surface of the cap. In the illustrated example, three grooves 6 are provided, and the depth thereof is about half the thickness of the cap.

The present invention has the above-mentioned structure, and since the slit 5 in the axial direction is provided at the front end of the cap 4, the rigidity of the cap 4 is reduced. Furthermore, since the circumferential groove 6 is provided on the outer surface of the cap, the rigidity of the cap 4 is further reduced.

Therefore, even if the cap 4 is strongly tightened in a state where no heat is applied, the rigidity of the cap is small, so there is no risk of breaking even the spray plate 3 made of ceramic.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the tip of the combustion device, Fig. 2 is a side view of the tip, with the cap shown in longitudinal section;
3a to 3c are sectional views for explaining the function of the cap, and FIG. 4 is a partially cutaway perspective view of the cap of the present invention. 1... Burner nozzle body, 2... Back plate, 3... Spray plate, 4... Cap, 5
...slit, 6...groove, 7...female thread.

Claims (1)

[Scope of utility model registration request] In a combustion device of the type in which a back plate and a spray plate are pressed and fixed to the burner nozzle body by a cap screwed onto the burner nozzle body, the cap has an axial slit formed at its front end and a circumferential slit formed on its outer surface. 1. A combustion device characterized in that a groove is provided in order to relieve stress during press fixing by screwing.