JPS60237282A - Synthetic resin made check valve for pump - Google Patents

Abstract

PURPOSE:To permit to improve the resistance to corrosion of the check valve for pump by forming all of the valve body of check valve by synthetic resin. CONSTITUTION:The valve body 4 of the check valve is constituted of a disc- type valve disc 23, a leg 33, and a sealing body 24 pinched by the disc and the led and made by an elastic body while the valve disc 23 and the leg 33 are welded by supersonic welding. The leg 33 is formed with three pieces of guide legs 26, sliding along the internal periphery of an inflow path 6, and a groove 28 as well as a holding section 30, which are holding said sealing body 24 in water-tight. The valve disc 23 is formed with a guide rod 32, sliding in a guide hole 14, a bar-type valve rod 22 and a disc-type valve disc 20. Said leg 33 and valve disc 23 are formed by synthetic resin forming, therefore, machining after forming becomes unnecessary and the productivity of the valve may be improved.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to check valves for pumps, and in particular to check valves used for pressurizing tap water, etc., which have been improved with the aim of improving productivity. related to what was done.

[・Background of the invention]

Conventionally, for example, JIS B
A centrifugal pump such as No. 8314 (electric well pump for shallow wells) has been used, but recently, this pump has been increasingly used for pressurized tap water supply. Conventional check valves for vortex pumps have been made of copper alloys such as brass. However, when vortex pumps began to be used to pressurize tap water, chlorine for sterilization was mixed into the tap water, and this chlorine content caused the tap water to become an electrolyte for copper alloys, causing desorption. Produces corrosive effects such as zinc phenomenon. As a result, the above-mentioned check valve corrodes after being used for a short period of time, resulting in a problem that the sealing performance is significantly reduced.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks of the prior art, it is an object of the present invention to provide a pump reverse valve with excellent corrosion resistance.

[Summary of the invention]

The present invention comprises a valve body holding a sealing body such as an elastic body, a valve chamber housing the valve body, a valve seat in which the sealing body abuts in the valve chamber, and a valve seat communicating with the valve seat. In a check valve having a structure including an inflow passage and an outflow passage opening downstream of the valve seat, the valve body is moved into the inflow passage by three guide legs and a holding portion for the sealing body. and a valve disk part also made of synthetic resin, which has a flat plate-shaped valve disk that comes into contact with the sealing body and a guide rod that slides into a guide hole provided on the outflow path side. The leg and the valve disk are integrally formed by joining them (by ultrasonic welding or the like), and an opening leading to the outside from the vicinity of the ultrasonic weld is provided in the leg or the valve disk. It was established.

[Embodiments of the invention]

FIG. 1 is a sectional view showing an embodiment of a synthetic resin check valve according to the present invention, in which a valve body 4 made of thermoplastic synthetic resin is housed in a valve chamber 2. In FIG. The valve chamber 2 is constructed by attaching a body 10 having an inlet passage 6 and a valve seat 8 to a cover 16 having an outlet passage 12 and a guide hole 14 via a backing 18i made of an elastic material such as rubber. It is configured.

Further, the valve body 4 is pressed against the valve seat 8 by a pressure spring 19 to improve sealing performance.

As shown in FIG. 2, the valve body 4 has a disc-shaped valve disk portion 2.
3 and leg portions 33 sandwich a sealing body 24 made of an elastic body, and the valve disk portion 23 and leg portions 33 are integrated by ultrasonic welding.

The leg portion 33 is formed with three guide legs 26 that slide along the inner periphery of the inflow channel 6, a groove portion 28 that holds the sealing body 24t in a watertight manner, and a holding portion 3o. On the other hand, the valve disk portion 23 is formed with a guide rod 32 that slides within the guide hole 14, a rod-shaped valve stem 22, and a disc-shaped valve disk 20.

As shown in FIG. 6, which will be described later, the valve stem 22 has a diameter that gradually becomes smaller from the valve plate 20 side to the guide rod 32 side, and the leg portion similarly has an undercut in the axial direction. It has no shape. Therefore, when the leg portion 33 and the valve disk portion 23 are molded from synthetic resin, machining after molding is not necessary, and productivity can be improved.

As shown in FIG. 3, the holding portion 30 of the valve body 4 has an outer radius "e" that is smaller than the radius R of the circumscribed circle of the three guide legs 26. As shown, even if the center line 34 of the valve body 4 deviates from the center line 36 of the valve seat 8, the holding part 30 of the valve body 4 may ride up on the valve seat 8 and cause a sealing failure. As in the prototype valve body 4' shown in FIG. In the case of the dimensions, when the valve body 4' is shifted to the right as much as possible as shown in FIG.
Due to the difference in curvature from the outer radius r of 0, the valve body 4' is larger than the dimensional difference between the circumscribed circle of the guide leg 26 and the inner circumference of the valve seat 8 (the gap between the guide leg 26 and the valve seat 8). As a result, the deviation increases by the dimension δ. On the other hand, as mentioned above, the holding part 3
This problem can be solved by making the outer radius r of 0 smaller than the radius R of the circumscribed circle of the guide leg 26 by an appropriate dimension.

FIG. 6 shows the valve disk portion 23 and leg portions 33 that constitute the valve body 4.
This figure shows the state of ultrasonic welding. Legs 3
3, two stepped welded portions 38 are provided above the groove portion 28, and two diagonal stepped welded holes 40 are provided on the lower surface of the valve disk portion 23 opposite to the welded portions 38. ing,
A cylindrical stand 42 is attached to the inside of the guide leg 26 to hold the holding part 3.
0, and applying ultrasonic waves of about 20 KHz while pressing the upper surface of the valve plate part 23 with the oscillator 44. Then,
Vibration frictional heat is generated at the contact portion between the welding portion 38 and the welding hole 40, and the valve plate portion 23 and the leg portion 33 are fused to each other to form an integral structure.

The above-mentioned guide legs 26 have cylindrical legs and are arranged to face each other in parallel, thereby stably fixing and positioning the legs 33 to the table 42, thereby allowing good ultrasonic welding work. . In addition, there are fewer changes in direction of the flowing water flowing between the guide legs 26, and flow resistance is also reduced.

Further, the welded portion 38 is formed so that its outer diameter Dw is smaller than the outer diameter d of the holding portion 30. This is done by positioning the welding part 38 and the welding hole 4o on the inner periphery side of the outer periphery of the stand 42 and the oscillator 44, which contact the holding part 30, so that the direct vibration is applied from the oscillator 44. Also, consideration has been given to improving welding efficiency and obtaining good welding strength. Further, the outer diameter Dw of the welded portion 38 is smaller than the inner diameter of the inflow path 6. This is done in order to prevent pressure from the discharge side from being applied to the ultrasonic welded portion when the valve body 4 is closed, and to maintain the pressure resistance of the welded portion.

The inner diameter of the sealing body 24 is made smaller than the outer diameter of the groove 28, and the fit between the two is a tight fit.
The hermeticity of the groove portion 28 is maintained.

Further, the ultrasonic welding part 38 is located inside the groove part 28 of the sealing body 24. This is done so that even if ultrasonic welding is not performed over the entire area of the welded part 38 and the watertightness of the welded part 38 is insufficient, the sealing action of the valve seat 8 of the valve body 4 will not be adversely affected. It is something.

Further, in the vicinity of the welded portion 38, the leg portion 33 and the valve plate portion 2
If a gap 46 is provided between the oscillator 44 and the oscillator 44, the surplus of the welded resin will be stored in the gap 46, thereby preventing the high temperature molten resin from adhering to the oscillator 44 or damaging the sealing body due to heat. Nor.

Also, an opening 48 leading from the vicinity of the welded portion 38 to the outside.
By providing this, the gas and air generated when the ultrasonic wave first hits can be smoothly discharged. This is because when the gas is confined inside in a compressed state, it becomes high pressure and generates internal stress. This was done in order to prevent damage to the resin over time and creep deformation. Note that the opening 48 may be provided in the valve plate portion 41 instead of the leg portion 33.

〔Effect of the invention〕

As explained above, the present invention provides a synthetic resin check valve that has excellent corrosion resistance and can be used with high reliability.
It also provides a practical and significant effect in improving the reliability and quality of BOOZ.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the synthetic resin check valve according to the present invention, Fig. 2 is a partial sectional view of its valve body, Fig. 3 is a bottom view of Fig. 2, and Fig. 4 is a main view of the valve body. FIG. 5 is a bottom view of FIG. 4, and FIG. 6 is an explanatory diagram of an ultrasonic welding process for a valve body. 2...Valve chamber, 4...Valve body, 6...Inflow path, 8...
・Valve seat, 12...Outflow path, 14...Guide hole, (1
... Valve seat part, 24 ... Sealing body, 26 ... Guide leg, 3
2...Guide rod, 33...Legs, 48...Opening. Agent Patent Attorney Akio Takahashi 6 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A valve body that holds a sealing body such as an elastic body, a valve chamber that houses the valve body, a valve seat that the sealing body abuts in the valve chamber, and a valve seat that is in contact with the sealing body; A check valve comprising an inflow passage communicating with a seat and an outflow passage opening on the downstream side of the valve body, wherein the valve body has legs and a valve plate made of thermoplastic synthetic resin, respectively. The leg portion has three guide legs that slide into the inflow channel and a holding portion for the sealing body, and the valve plate portion has a flat valve that abuts the sealing body. It has a disc and a guide rod that slides in a guide hole provided on the outflow path side, and the valve body is integrally formed by joining the leg parts and the valve disc part by ultrasonic welding or the like. Synthetic resin check valve for pumps. 2. In the synthetic resin check valve for a pump according to claim 1, the legs of the valve body and the valve disk are joined by ultrasonic welding, and the vicinity of the ultrasonic welded portion is 1. A synthetic resin check valve for a pump, characterized in that an opening communicating with the outside is provided in the leg portion or the valve plate portion.