JPH0112744Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a pressure switch for automatic operation of pumps, etc., and its purpose is to delay the opening of contacts during operation to prevent frequent stoppages of the pump and to improve its durability. do.

Conventional pumps operate and stop using pressure switches with predetermined closed and open circuit pressures to control the pressure inside the connected tank within a certain range, but depending on conditions such as the pump's capacity and the amount of water used, Pumps frequently stop operating due to pressure fluctuations over time, often resulting in poor durability due to contact welding or burnout.
In particular, recently there has been a strong demand for miniaturization, which has reduced the amount of air built into the tank, resulting in the pump having to be operated more frequently. Therefore, in the present invention, a plunger is engaged with the overhanging part of the upper flange by a spring, and the pressure receiving chamber is divided into an inner chamber and an outer chamber, and the pressure increase in the outer chamber is delayed and transmitted to the inner chamber, and the pressure rise in the outer chamber is The contacts do not respond to short-term pressure changes, reducing the frequency of opening and closing of the pump and pressure switch.

For example, even if the pressure difference between closed and open circuits is small, such as pumps used with water heaters and instantaneous water heaters that require as constant a pressure as possible, the frequency of opening and closing can be reduced. decrease,
Durability can be improved.

To explain the embodiment of the present invention shown in FIG.
is a diaphragm, which drives the contact opening/closing portion C by the presser 2 placed thereon in response to pressure changes. 3 is an upper flange that holds the peripheral edge of the diaphragm 1 and has an overhanging portion 3A in the middle; 4 is a lower flange connected to the upper flange 3 via a packing 5; 7 is a plunger;
It is constantly biased by a spring 6 installed between A and A,
The conical portion 7B on the upper surface is engaged with the conical concave surface 3C on the inner surface of the overhanging portion 3A of the upper flange 3, closing the communication hole 3B at the center of the upper flange 3 and dividing the pressure receiving chamber into an inner chamber D and an outer chamber E. partition into. A narrow groove 7A is provided on the side surface of the conical portion 7B of the plunger 7 to communicate the inner and outer chambers D and E.

Next, regarding the operation, when the pump is operated and the pressure increases, the plunger 7 is pushed up by the action of the spring 6 and the flow of water, and its conical portion 7B is pressed against the conical concave surface 3C of the upper flange 3. Since the water flow gradually enters only through the narrow groove 7A of the plunger conical portion 7B, the pressure Pd in the inner chamber D is lower than the pressure Pe in the outer chamber E, as shown in FIG.
After a considerable time delay, the diaphragm 1 and the pusher 2 operate to open the contact C and stop the pump. After that, the pressures in both the inner and outer chambers reach an equilibrium state, but when the amount of water in the tank decreases due to the use of water and the pressure decreases, the water flow flowing down from the central hole 3B resists the elasticity of the spring 6 and pushes the plunger. 7 is pushed down, and the pressure in the inner chamber D decreases at approximately the same speed as the pressure in the outer chamber E (the pressure in the inner chamber D decreases at approximately the same speed as the pressure in the outer chamber E). When the predetermined closing pressure is reached (as shown by the descending line from OFF to ON in Figure 3), diaphragm 1
Then, the pusher 2 returns, the contact portion C closes again, and the pump starts. That is, when the pressure increases, the conical part 7B of the plunger 7 comes into close contact with the corresponding concave surface 3C of the upper flange 3, and the inner and outer chambers D and E are communicated only through the narrow groove 7A, and pressure is transmitted. ,
Although its speed is delayed, when the pressure decreases, the conical part 7B of the plunger 7
Away from C, the inner and outer chambers D and E are widely circulated, and the pressure in both chambers is uniformly reduced.

Note that the thin groove 7 on the side surface of the conical portion 7B of the plunger 7
Instead of A, if a narrow groove is provided in the concave surface 3C of the overhanging portion 3A of the upper flange 3, or if a slight difference is made in the shape of this concave surface and the corresponding conical portion side surface of the plunger, the flow can be improved. It is possible and has the same effect as above.

Next, FIG. 2 shows the proposed device to be used in addition to an existing pressure switch, in which a mounting screw portion 13C to be screwed into the existing pressure switch 20 is provided at the tip of the upper flange 13, and a conical portion of the plunger 7 is provided. 7B
is engaged with the concave surface 13B of the upper flange 13 to divide the pressure receiving chamber into an inner chamber D and an outer chamber E. And the pressure switch 20 is the same as described above.
Although the opening operation is delayed, this is caused by the pressure difference between the inner and outer chambers, so regardless of the set pressure of the pump, it can be added to the conventional pressure switch in any case to improve the life of the existing pump. be able to.

That is, in the conventional pressure switch, as shown in FIG. 3, since the diaphragm directly responds to external pressure, the contacts open and close immediately due to short-term pressure fluctuations, causing the pump to frequently stop operating. For this reason, as shown in FIG. 4, for example, there is a cutout 31A in the middle of the pressure receiving chamber.
An adjustment screw body 31 is provided to partition the inner chamber D.
It has been proposed to delay the pressure Pd of the external pressure Pe from fluctuations in the external pressure Pe, but as shown in Fig. 3, this is delayed both when the pressure rises and falls. If the external pressure drops significantly, the pump will start after the pressure has dropped even further than the predetermined closed circuit pressure, which may cause problems such as not being able to pump water to high-rise water usage locations.

However, in the present invention, as shown in Figure 3, when the pressure increases, the internal chamber pressure Pd is delayed to reduce the frequency of pump operation, and when the external pressure Pe decreases, the internal chamber pressure Pd is also decreased at the same time. Since the pressure is reduced and the circuit is closed at a predetermined pressure, the aforementioned defects are eliminated.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view of the pressure switch of the present invention, Fig. 2 is a partially cutaway front view of the present invention used in conjunction with an existing pressure switch, Fig. 3 is a conventional pressure switch, and 3 is a pressure switch of the present invention. FIG. 4 is a partially cutaway front view of a conventional pressure switch. 1; flange, 2; pusher, C; contact opening/closing part,
3; Upper flange, 3A; Overhang portion, 3B; Communication hole, 3C; Conical concave surface, 4; Lower flange, 4
A: step, 6: spring, 7: plunger, 7A: narrow groove, 7B: conical portion, D: inner chamber, E: outer chamber.

Claims (1)

[Scope of utility model registration request] A thin groove is provided on either the side surface of the conical part on the upper surface of the plunger or the conical concave surface on the inner surface of the upper flange projecting part, and a spring elastically installed between the side surface of the conical part on the upper surface of the plunger and the stepped part of the lower flange allows the conical part of the plunger to be The pressure receiving chamber formed by the lower flange and the diaphragm on which the presser for driving the contact opening/closing section is mounted is divided into an inner chamber and an outer chamber by engaging the shaped portion with the concave surface of the upper flange extension portion. A pressure switch that delays operation when pressure increases.