JPH0325516Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention relates to a disc-type steam trap that is attached to a steam piping system and automatically discharges condensate generated therein, and specifically uses bimetal to prevent air locking. Concerning what to do.

A disc-type steam trap automatically controls a valve disc, which separates from and seats against a valve seat surface consisting of an inner and outer ring valve seat, to open and close the valve based on pressure changes in a variable pressure chamber formed behind the valve disc. It drains water automatically.

In this disc type steam trap,
Even if low-temperature condensate or air flows in during startup, the valve disc cannot be opened due to the air remaining in the variable pressure chamber, and if air flows into the variable pressure chamber during operation, steam As in the case, the valve closes instantaneously, and once the valve is closed, unlike steam, air does not cause condensation, so even if condensate flows in, the valve cannot be opened, resulting in so-called air locking.

Conventionally, bimetals have been used to eliminate this air locking. this is,
By utilizing the bending effect of the bimetal due to temperature changes, the valve disk is forcibly pushed up to open the valve when the temperature is low, and the valve disk is prevented from interfering with the valve disk when the temperature is high.

At this time, the bimetal must have a large displacement force and amount of displacement, and must be small. In other words, a large force is required to overcome the closing force of the valve disc, and the valve disc must be opened wide to eliminate air locking in a short period of time. This is because it is necessary to make it small so as not to increase its shape.

Prior Art Therefore, the present applicant previously proposed a technique for eliminating air locking by using a small bimetal with a large displacement force and amount of displacement, as published in Japanese Utility Model Application No. 61-70698.

A housing hole is made in the annular groove between the inner and outer valve seats, and a double helical bimetal is placed between the valve disk and the long strip-shaped plate. However, when the temperature is low, the bimetal expands and forces the valve disk up to open the valve.
This prevents it from contracting and interfering with the valve disk at high temperatures.

Bimetal is made by forming long strips of plate material into a double spiral shape, so even if a large number of bimetals are used, it can be made small.Also, even if it is small, a large number of bimetals are used, so the displacement force and displacement can be reduced. The amount becomes larger.

Problem that the invention aims to solve: In this case, the bimetal is bent sideways,
There is a problem that air locking cannot be prevented. That is, the lower part of the bimetal is guided by the surrounding wall of the receiving hole, but the upper part is located in the annular groove and tends to tilt, making it impossible to obtain the desired amount of displacement to push up the valve disk. Further, in this state, the valve disk is struck by the impactful seating and deforms.

Therefore, the technical problem of the present invention is to make the bimetal small and have a large displacement force and amount of displacement, and to prevent it from bending laterally.

Means for Solving the Problems The technical means of the present invention taken to solve the above technical problems is to install a guide rod in the annular groove between the inner and outer ring valve seats that extends close to the inner and outer ring valve seat surfaces. A double helical bimetal made of a long strip of plate material spirally wound is placed around the stand and guide rod, and when the temperature is low, the bimetal expands and forces the valve disk upward. The valve is opened and contracts at high temperatures to prevent it from interfering with the valve disk.

Effect The operation of the above technical means is as follows.

Bimetal is made by forming a long strip of plate material into a double helical shape, so it can be made compact even if a large number of bimetals are used.Even if it is small, a large number of bimetals are used, so the displacement force and amount of displacement can be reduced. is large.

In addition, a guide rod extending from the bottom of the annular groove to near the inner and outer valve seating surfaces is set up, and a double helical bimetal is placed around the guide rod. It never bends.

Effect of invention The present invention produces the following specific effects.

Since the bimetal of the present invention is formed into a double helical shape, the displacement force and amount of displacement are large, and low-temperature condensate and air at startup can be removed in a short time, reducing startup time.

Furthermore, since the displacement force and amount of displacement are large, precise dimensional accuracy is not required, and manufacturing costs can be reduced.

Furthermore, since the bimetal does not bend laterally, it can maintain good air locking function over a long period of time, resulting in a longer service life.

Example An example showing a specific example of the above technical means will be described.

Embodiment 1 (See FIGS. 1 to 4) An inlet 2 and an outlet 3 provided substantially on the same axis in a main body 1, and a recess 5 into which a valve seat member 4 is attached are formed. The inlet 2 communicates with the center of the recess 5 through the screen 6, and the outlet 3 communicates with the periphery of the recess 5.

A valve seat member 4 is disposed in the recess 5 through a two-ring annular gasket, and is fastened to the main body 1 with an inner cover 7 screwed onto the inner peripheral side wall of the recess 5 through the gasket. A variable pressure chamber 8 is formed between the valve seat member 4 and the inner lid 7.

An inflow hole 9 is provided through the center of the valve seat member 4 to communicate with the inflow port 2, and an annular groove 10 is provided around the periphery.
An annular inner valve seat 12 is formed between the inflow hole 9 and the annular groove 10, and an annular outer ring seat 13 is formed outside the annular groove 10. A valve disk 14 is placed in the variable pressure chamber 8 and is seated on and off the inner and outer ring valve seats 12 and 13 at the same time. An outer cover 15 is screwed onto the outside of the inner cover 7 via a gasket to form a heat preservation chamber 17 that communicates with the inlet 2 through a through hole 16.

A housing hole 18 is provided on the opposite side of the annular groove 10 to the outflow hole 11.
will be established. A guide rod 19 is press-fitted into the bottom wall of the accommodation hole 18 and erected. The upper end of the guide rod 19 extends close to the inner and outer ring valve seat surfaces. A bimetal 20 is arranged around the guide rod 19. The bimetal 20 is formed by forming a long strip-shaped plate into a helical shape as shown in FIG. 2, and further into a helical shape as shown in FIG. The bottom of the bimetal 20 is the guide rod 19
It is caught between the stepped parts of the wall to prevent it from slipping out.

The operation of the above embodiment will be explained.

At startup, the temperature inside the trap is low, and the bimetal 20 expands as shown in Figures 1 and 4.
Its upper end protrudes from above the surfaces of the inner and outer ring valve seats 12 and 13, and pushes up the valve disk 14 to open the valve.
A large amount of low-temperature condensate and air flowing in through the inlet 2 and the inflow hole 9 are discharged in a short time through the annular groove 10, the discharge hole 11, and the outlet 3. Next, when high-temperature condensate flows in, the bimetal 20 is heated and contracts, so that it does not come out onto the surfaces of the inner and outer ring valve seats 12 and 13 and does not interfere with the valve disk 14. Thereafter, based on the operating principle of the well-known disc steam trap, steam is not released and condensate is discharged. During operation, air leaks into the variable pressure chamber 8.
When the temperature inside the variable pressure chamber 8 drops below a predetermined temperature, the bimetal 20 expands and opens the valve disk 14.
Eliminate air locking.

In this embodiment, since the bimetal 19 is arranged in the annular groove 10 eccentrically with respect to the valve disk 14, the lever principle provides a large valve closing deterrent force that eliminates air locking.

Embodiment 2 (See FIG. 5) In this embodiment, an operating rod 21 that can be vertically displaced is arranged around a guide rod 19, and a double helical bimetal 20 is connected to the valve disk 1 via the operating rod 21.
This is designed to push up the number 4. According to this embodiment, since the operating rod 21 is interposed between the valve disk 14 and the bimetal 20, it is possible to prevent the valve disk 14 from directly colliding with the bimetal 20 and causing it to be deformed or damaged. Components corresponding to the first embodiment shown in FIGS. 1 to 4 are given the same reference numerals, and detailed explanations are omitted.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a disc-type steam trap according to an embodiment of the present invention, Figures 2 and 3 are diagrams showing the manufacturing process of the double helical bimetal of Figure 1, and Figure 2 is a strip of steam trap. Figure 3 is a front view of a bimetal with a flat plate shaped into a single helical shape, Figure 3 is a plan view of Figure 1 which is a double helical shape made by further spiraling the one in Figure 2, and Figure 4 is FIG. 1 is an enlarged sectional view of the valve seat member portion, and FIG. 5 is a sectional view similar to FIG. 4 of another embodiment of the present invention. 4... Valve seat member, 8... Variable pressure chamber, 10... Annular groove, 12... Inner ring valve seat, 13... Outer ring valve seat, 14
... Valve disk, 18 ... Accommodation hole, 19 ... Guide rod, 20 ... Double helical bimetal.

Claims (1)

[Scope of utility model registration request] A guide rod that extends close to the inner and outer valve seats is placed in the annular groove between the inner and outer valve seats, and a long strip of plate material is wound around the guide rod into a spiral shape. This is a disc-type steam trap in which a type of bimetal is arranged, and when the temperature is low, the bimetal expands and forces the valve disk to open, and when the temperature is high, it contracts and does not interfere with the valve disk.