JPS5926252Y2 - Flow nozzle installation structure - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a structure for mounting a flow nozzle in a flow rate detection device.

The structure of conventional flow nozzle installation is as shown in Figures 1 and 2. The flow nozzle 02 is pushed into the same inner diameter part of the installation pipe 01 with the inlet end of the nozzle first, and the holding ring 03 is inserted. Push the ring 03 further and fit it into the fitting outer diameter provided on the outer periphery of the nozzle 02. Using a jig, take out one dimension as shown in the figure and position the ring 03.
The ring 03 was welded to the mounting pipe 01 with only the ring 03 pushed in slightly.

Next, pull out the nozzle 02 using a jig, tighten it tightly to the ring 03, and then drill a pin hole in the mounting pipe 01, ring 03, and nozzle 02 from the outer circumference of the mounting pipe 01, and insert the pin 04 into the pin hole. was press-fitted and then welded to the outer periphery of the mounting pipe 01.

The above installation requires a large number of parts in terms of structure and installation work, requires special jigs, and requires careful attention to the depth of the pin hole, as if it is too deep, it may penetrate the nozzle. It becomes unusable.

Furthermore, if the depth of the hole is shallow, there are drawbacks and problems, such as the possibility that the position of the nozzle may shift during operation.

The present invention was made to eliminate the drawbacks and problems of the conventional method described above. The flow nozzle is welded and fixed using the formed annular shoulder as a positioning reference for the nozzle.The number of parts is small, no jig is required, and installation is extremely easy.The installation of the flow nozzle has a simple structure. provide.

The present invention will be explained below based on an embodiment shown in FIGS. 3 to 5.

Reference numeral 1 indicates a flow nozzle attachment pipe, 3 indicates a flow nozzle, and 6 and 6' indicate fluid pressure outlets disposed at the inlet and outlet sides of the flow nozzle 1, respectively.

Inside the mounting pipe 1 of the flow nozzle, an annular shoulder 2 is formed by an annular step provided on the inner surface of the pipe at the nozzle mounting position, and the inner diameter d2 of the pipe on the downstream side is the inner diameter d1 of the pipe on the upstream side. Make the diameter larger.

The flow nozzle 3 has a trumpet-shaped cross section, and its outer diameter matches the pipe inner diameter d2 of the large diameter portion of the attached pipe 1, and the distance t between the starting point 4 of the curved inner wall at the inlet end and the outer diameter is as described above. This is made to match the step size of the annular shoulder portion 2.

Note that a corner cut 7 is added to the corner between the inlet end surface and the outer periphery.

(See FIG. 4) Therefore, the corner drop 7 on the nozzle further ensures the accuracy of the actual installation dimensions.

To install the flow nozzle 3 into the installation pipe, push the flow nozzle 3 into the inside of the large-diameter part of the installation pipe 1 with its artificial end first, making sure that the inlet end is in close contact with the annular shoulder 2. Weld the outer circumferential part of the nozzle 3 to the inner wall of the large diameter part of the mounting pipe 1 5
and fix it.

Since the position of the annular shoulder 2 is set in advance at a distance from the outlet end of the attachment tube 1, the distance l between the nozzle outlet end and the attachment tube outlet end in the installation state of the nozzle is precisely determined. The dimensions have been obtained.

Since the present invention is constructed as described above, there is no need for jigs for inserting, positioning and welding the flow nozzle 3 into the mounting pipe 1, and the flow nozzle 3 can be accurately pressed into contact with the annular shoulder 2. Positioning is performed and welding can be easily performed simply in that state.

In addition, since the distance t between the starting point 4 of the curved inner wall and the outer diameter of the flow nozzle 3 is made to match the step dimension of the annular shoulder 2, the surface that transitions from the small inner diameter part of the attachment pipe 1 to the flow nozzle 3 is smooth, and the flow of fluid is smooth. It can make the flow smoother.

In addition, the present invention does not require holding rings or pin parts like conventional ones, and the installation work is easy because there is no drilling of pin holes or welding of pins, which requires great care and skill. And the cost is low.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of the structure of a conventional flow nozzle installation, Fig. 2 is a view taken along the line II-II in Fig. 1, and Fig. 3 is a longitudinal cross-section showing an embodiment of the present invention. Figure 4 is a partially detailed sectional view of the flow nozzle in Figure 3, and Figure 5 is a detailed cross-sectional view of the flow nozzle in Figure 3.
It is a view taken along the line ■-■ in the figure. 1: Mounting pipe, 2: Annular shoulder, 3: Flow nozzle, 5: Welding, 6, 6': Fluid pressure outlet.

Claims (1)

[Scope of utility model registration request] A flow rate detection device comprising a flow nozzle mounting pipe, a flow nozzle inserted and fixed into the mounting pipe, and fluid pressure outlets respectively arranged on the mounting pipe wall at the front and rear positions of the flow nozzle, wherein the flow nozzle For installation, the inner diameter of the mounting pipe on the downstream side of the position is larger than the inner diameter of the mounting pipe on the upstream side, and a step is added at the boundary to form an annular shoulder.On the other hand, the outer diameter of the flow nozzle is The inlet diameter of the nozzle hole is formed to match the upstream inner diameter of the mounting pipe, so that the inlet end of the flow nozzle is in close contact with the annular shoulder, and the outer periphery of the outlet side of the nozzle is in close contact with the annular shoulder. The installation structure of the flow nozzle is characterized by being fixed by welding to the inner diameter inner wall of the downstream side of the pipe.