JPS6011514Y2 - power element - Google Patents

Description

[Detailed description of the invention] This invention includes, for example, a temperature sensing part that senses the temperature of a controlled part;
The power element consists of a capillary tube that transmits the sealed gas pressure corresponding to the temperature of the temperature sensing part to a pressure responsive body (for example, a bellows), and a pressure responsive body that expands and contracts in proportion to the transmitted gas pressure. This relates to a power element with an improved connection part (bellows).

The conventional method for connecting a capillary tube and a bellows is to first connect the bellows bottom plate made of brass or the like with a braze, etc., and then solder the bellows bottom plate to which the capillary tube is connected and the end peripheral surface of the bellows. Previously, the method used was to bond the parts by soldering, etc., but since this method requires soldering in the later process, it is necessary to bond in the previous process by brazing, which has a higher melting temperature than soldering. Brazing has the disadvantage that the bellows bottom plate is annealed and pinholes, cracks, etc. occur.

In order to eliminate the above drawbacks, this invention does not require brazing,
Moreover, the connection is completely sealed and the connection structure is devised to prevent gas leakage, in order to provide a power element that is superior in terms of both quality and production.

The present invention will be explained below with reference to illustrated embodiments.

Since the capillary tube 1 is made of copper, it has flexibility. For example, as shown in FIG. Furthermore, after tightening with the second vise 6, the first
When pressure is applied with a hammer or the like in the direction of the vise 5, a flange portion 7 in which the portion 1 bulges outward is formed.

The capillary tube 1 is inserted into the through hole 4a of the bellows bottom plate 4 and locked on the flange 7, and the capillary tube above the flange 7 is attached to the second flange portion 8 in contact with the bottom plate 4 by the above operation. As shown in FIG. 3, the bellows bottom plate 4 is sandwiched between the collars 7 and 8 of the capillary tube to form a combined body.
Next, the bellows end peripheral surface 3 is attached to the inner surface 4b of the bellows bottom plate of the combined body.
a, and after charging solder 9 into the bellows bottom plate, the solder is melted by heating with hot air from the outside of the bottom plate, and the bellows and the bottom plate, as well as the capillary tube and the bottom plate, are simultaneously bonded with solder.

With the above configuration, the bellows bottom plate 4 and the capillary tube 1 do not need to be brazed, so there will be no annealing of the bottom plate or pinhole cracks in the brazing, and the connection between the bellows bottom plate 4 and the capillary tube 1 will be made at the flange. At steps 7 and 8, the position of the capillary tube is stabilized, and the circumferential surface of the collar 8 is bonded to the bottom plate 4, so the bonding area is wide and the connection is secure, and the solder also enters the bonded area between the bellows 3 and the bottom plate 4 at the same time. It is then glued together.

As described above, the present invention eliminates brazing and solders the bellows and bellows bottom plates after soldering the bellows bottom plate and the capillary tube. Finally, the bellows bottom plate and the capillary tube, and the bellows bottom plate and the bellows are bonded together with solder at the same time.This eliminates defects such as deterioration of the bellows bottom plate and also contributes to improving production efficiency.

[Brief explanation of the drawing]

FIG. 1 is an external view showing an example of a power element. FIG. 2 is an explanatory diagram showing an example of creating a flange of a capillary tube. FIG. 3 is an explanatory sectional view showing the joining of the capillary tube and the bellows bottom plate according to the present invention. FIG. 4 is a sectional view showing the capillary tube and the bellows bottom plate, and the soldering state of the bellows and the bellows bottom plate according to the present invention. 1... Capillary tube, 2... Temperature sensing part, 3... Bellows, 4... Bellows bottom plate, 7, 8... Tsuba , 9... solder.

Claims (1)

[Scope of utility model registration request] A temperature sensing part that detects the temperature of the controlled part, a capillary tube that transmits the pressure of the sealed gas corresponding to the temperature of the temperature sensing part to the bellows,
In a power element consisting of a bellows that expands and contracts in proportion to the transmitted pressure, the bellows bottom plate is sandwiched between two-stage flanges formed on a capillary tube that passes through the bellows bottom plate, and one end of the capillary tube is attached to the bottom plate. open inward,
A bellows is installed so that the end circumferential surface of the bellows is in contact with the inner circumferential surface of the bellows bottom plate, and the nozzle charged inside the bellows bottom plate is heated with hot air from the outside of the bottom plate, and the capillary tube and the bellows bottom plate as well as the bellows and the bellows bottom plate 4 are heated. A power element characterized by being made by simultaneously soldering and gluing.