JPS5923071B2 - Manufacturing method of cartridge heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a cartridge heater, and its purpose is to securely hold the bobbin inside the metal tube in the center and to securely hold the bobbin inside the metal tube in the center while manufacturing the cartridge heater. The purpose is to prevent poor proximity between the tip and the bottom plate of the metal tube.

A conventionally known method for holding the bobbin in the center of the metal tube of a cartridge heater is as shown in FIG.
At the inner tip of the metal tube 1, the terminal rod 3 was protruded from the end of the bobbin 4 and inserted into a hole made in the guide plate 9 to hold the bobbin 4 in the center.
Insulation failure has occurred due to the proximity of the terminal bar 3 and the tip of the terminal bar 3.
Further, due to variations in the hole diameters of the guide plate 9 and the bobbin 4, there was a drawback that the bobbin 4 became eccentric with respect to the inner diameter of the metal tube 1.

The present invention has been made to eliminate such drawbacks, and the drawings are explained below. 1 is a metal tube, 2 is a bottom plate connected to the end surface of the metal tube 1, 3 is a heat-resistant metal terminal bar, and 4 is a metal tube.
5 is a metal resistance heating wire; 6 is a heating element consisting of the bobbin 4, heating wire 5, and terminal bar 3; T is a heat-resistant insulation powder; 8 is a sealing material; 1 `` is a guide plate formed by molding heat-resistant insulating powder and has a pair of protrusions on one side, and further has a pair of terminal rod insertion holes, an outer peripheral piece, and a biting part; 11 is the outer periphery of the guide plate 1. Piece, 1
2 is a protrusion of the guide plate 1'', 13 is a terminal rod insertion hole of the guide plate 10, and 14 is a biting portion of the guide plate 10.

Next, in the manufacturing method of the embodiment according to the present invention, first, the terminal bar 3
A heating wire 5 is attached to the outer periphery of the bobbin 4, which has a pair of holes that pass through the bobbin 4.
After winding, insert both ends into the terminal rod insertion hole of the bobbin 4, and further insert the terminal rod 3 to form a heating element i in which the two are connected by contact within the terminal rod insertion hole. , the terminal rod 3 is inserted to a depth where it slightly indents from the tip surface of the bobbin 4, and the tip of the heating element 6 is held in the center of the metal tube 1 by aligning with the terminal rod insertion hole in this biting part. A guide plate 10 having a protrusion 12 on one side is attached.

By slanting the peripheral side surface into a conical shape, this protrusion 12 can eliminate variations in the inner diameter of the terminal rod insertion hole, and the outer diameter of the outer peripheral piece 11 of the guide plate 10 is smaller than the inner diameter of the metal tube 1. The bite portions 14, which are somewhat small and are provided alternately with the outer peripheral pieces 11, are cutouts for passing the insulating powder T through the back side of the guide plate 1-0. The guide plate 10 is further provided with l pairs of terminal rod insertion holes 13 for holding the lead-out side of the terminal rod 3 of the heating element body (1) in the center of the metal tube 1.
Guide plate 1 by matching protrusion 12 on one side.
When the heating element 0 is inserted and fixed, the other terminal rod 3 is passed through the terminal rod insertion hole 13ffC of another guide plate ('', and the guide plate V'' is fixed. −
0, a heating element 5, and another id plate 1 are loaded into the metal tube 1 up to the bottom plate 2, and then the insulating powder 7 is inserted from the opening of the metal tube 1.
fills the internal space. This is a method of manufacturing a cartridge heater in which the outer diameter of the metal tube 1 is later reduced and a sealing material 8 is applied. As is clear from the above, the present invention is a method of fixing a heating element in a metal tube by using a protrusion of a peel-off plate at one end of the heating element, and using a protrusion of the same type at the other end. By using the terminal rod insertion hole on the guide plate, the heating element can be easily held in the center of the metal tube, and filling the insulation powder can be done easily. The bobbin can be fixed by matching the guide plate regardless of variations in the inner diameter of the terminal rod insertion hole of the bobbin.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a conventional guide plate, FIG. 2 is a perspective view showing a conventional guide plate, FIG. 3 is a longitudinal cross-sectional view according to the present invention, and FIG. 4 is a perspective view showing a guide plate according to the present invention. be. The explanation of the symbols in the figure is as follows. 1: Metal tube, 3: Terminal bar, 6: Heating element, 7: Insulating powder,
10: Guide plate, 12: Projection, 13: Insertion hole.

Claims (1)

[Claims] 1 In a cartridge heater in which a heating element is inserted into a bottomed cylindrical metal tube and filled with a heat-resistant insulator, the metal tube 1
Before being loaded into the interior, only the protrusion 12 of the guide plate 10 having the terminal rod insertion hole 13 and the protrusion 12 is inserted and fixed into the tip located on the bottomed side of the metal tube of the heating element 1, and the other lead-out A cartridge heater made by passing the side terminal rod 3 through the insertion hole 13 of the guide plate 10 of the same type, loading these together into the metal tube 1, filling it with heat-resistant insulating powder 7, and processing the metal tube 1 to reduce its diameter. manufacturing method.