JPS6322392Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure switching solenoid valve that can quickly switch the pressurizing source pressure for the load in a pipeline.

A conventional example of this type of curved valve is a three-port solenoid valve as shown in FIG. That is, pressurized fluid, for example, supplied from the line 1 is normally cut off by a valve body closing the port to the line 1 by means of a spring 2, and when the solenoid 4 is energized, a low pressure source, e.g. atmospheric pressure The port to the line 5 communicating with the lower tank is closed and the load, for example the nozzle 6, is rapidly supplied with pressurized liquid. When the solenoid 4 is de-energized, the valve body 3 quickly opens the pipe 5, and the pressurized liquid returns to the low pressure source without being injected. However, in this type of solenoid valve, electric power is required to constantly excite the solenoid in order to maintain the valve body in the switching position.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a pressure switching solenoid valve that can increase or decrease the internal pressure of a pipe line at high speed with a small amount of electric power.

Next, the present invention will be explained based on the illustrated embodiments.

FIG. 2 shows a longitudinal cross-sectional view of the pressure switching electromagnetic valve according to the present invention, which is manufactured by assembling the same structural parts in a left-right and left-right arrangement.

Of these, 11 and 11' have the same structure, and have a cavity for forming the valve chambers 12 and 12' and slots 15 and 1 that communicate with the outside from this cavity.
6, 17, 15', 16', and 17'. At the tips of the slots 16, 16', the valve chambers 12, 12' are opened with small apertures in the orthogonal direction into the raised portions of the cavity walls for the valve chambers 12, 12'.
2' ports 18, 18' are formed. Similarly, the tips of the slots 15, 17, 15', 17' form ports 19, 20, 19', 20', each having a larger diameter at the outer end to fit into an external conduit. 21 and 21' are valve chamber 1, respectively.
It is a valve body that can open and close ports 18 and 18' with elastic parts 22 and 22' for preventing wear provided at the tips in respective cavities for ports 18 and 12'. Diaphragms 23, 2 are connected to such valve bodies 21, 21'.
3' and insert it into the respective cavities for the valve chambers 12, 12', and further insert the guides 24, 24' from behind and fit them with the outer peripheral edges of the cases 11, 11'. , 12'.
The valve bodies 21, 21' are further provided with plungers 27, 2.
7' are connected to each other, and these plungers 2
7 and 27' are inserted into the bobbin 28 of the solenoid 26 with compressed springs 29 housed in their respective rear recesses. Therefore, the respective plungers 27, 27' are pressed outward against each other,
When the solenoids 26 are energized, they are attracted inwardly against this spring force. Also, the guides 24, 2
4' fits into the mounting plates 31, 31' of the plate-shaped external metal fitting 30, and the bobbin 28 is also fixed at a predetermined position on the plate-shaped external metal fitting 30. Furthermore, during such an assembly process, the slot 17' of the valve chamber 12' which communicates with the low pressure source is covered so as not to be used, and the slot 17' of the valve chamber 12 which communicates with the high pressure source is closed.
6' are connected by a pipe line 52 (FIG. 3) to complete the solenoid valve according to the present invention.

As is clear from the figure, the pressure receiving surface formed by the cross section of the valve body 21 and the diaphragm 23 is much wider than the cross-sectional area of the port 18 in the valve chamber 12. That is, when the port 18 is opened under a predetermined pressure, the pressure receiving surface of the valve body 21 that is effective for opening the port 18 is larger than when it is closed, and the pressure receiving surface of the valve body 21 is larger in the opening direction corresponding to the area ratio. In response to the pressing force, the open state is maintained even when the solenoid 26 is de-energized. In other words, in a predetermined pressure range, the pressing force of the spring 29 in the closing direction is greater than the pressing force of the opening direction corresponding to the cross-sectional area of the port 18 in the valve body 21.
8 can be closed, but the force is set to such a degree that it cannot resist the pressing force corresponding to the pressure receiving surface when opened, and causes the valve body 1 to retreat. The flange 32 of the plunger 27 is for restricting such retreat of the valve body 21. Valve body 2 is intentionally placed on the valve chamber 12' side.
1' need not be constructed to induce such a self-retaining effect.

Next, we will discuss an application example when the pressure switching solenoid valve shown in Fig. 2 is used in an ink jet recording device.
This will be explained based on the diagram.

An ink tank 42 supplied with ink from an ink container 41 supplies ink to a pump 45 through a pipe line 43, and this pump 45 compares the ink pressure detected by a pressure sensor 47 attached to a pipe line 46 with a set value. By controlling the drive motor according to the comparison output of the comparator 53, ink at a set pressure can be delivered. The conduit 46 is further provided with an accumulator 48 for removing pulse pressure from the pump 45 and increasing the capacity. Pipe line 46 is valve chamber 1
2, and the port 19 is connected to the recording section 50 having the injection nozzle 49 through the conduit 54.
Connect to. A port 19' of the valve chamber 12' is connected to a conduit 51 that connects to the ink tank 42.

When recording, the pump 45 is driven in advance to increase the internal pressure of the pipe line 46 and to accumulate pressure in the accumulator 48, and when the internal pressure detected by the pressure sensor 47 reaches a set value, the pump 45 is driven. Let it stop. In this state, the port 18 of the valve chamber 12 is closed because the pressing force by the spring 29 is greater than the pressing force in the opening direction corresponding to its cross-sectional area. Then, when the solenoid 26 is momentarily excited for about 10 ms, for example, the plungers 27 and 27' are attracted to each other against the spring force, and both ports 18 and 18' are opened.
Therefore, pressurized ink flows into the valve chamber 12,
The spring 29 is pushed in the opening direction by a large force corresponding to a pressure receiving surface approximately equivalent to the area of the diaphragm 23, while the valve chamber 12' is communicated with the ink tank 42 under atmospheric pressure through a conduit 51, and the valve Since the valve chamber 12 is connected to the valve chamber 12 via a conduit 52 having a large resistance, the internal pressure of the valve chamber hardly increases instantaneously. As a result, when the solenoid 26 is de-energized, the port 18' of the valve chamber 12' immediately closes, but the valve body 21 of the valve chamber 12 remains retracted in the opening direction, and each of the recording sections 50 Ink is ejected from the nozzle 49.

When recording stops, if the solenoid 26 is energized for a longer time than when recording starts, for example, for about 0.5 seconds, the valve chamber 12
is communicated with the tank 42 under atmospheric pressure via the pipe 52, valve chamber 12' and pipe 51, the internal pressure of which is lowered, and the nozzle 4 with a small diameter for recording is connected.
From 9 onwards, ink cannot be ejected immediately. Even after the excitation of the solenoid 26 is finished, the internal pressure in the valve chamber 12 is falling, so the pressure does not momentarily rise to a high level, and the port 18 is closed by the pressure of the spring 29, and the ink jetting immediately stops.

FIG. 4 shows another embodiment of the present invention, 1
A load port 62, a pressurization source port 63, and a low pressure source port 64 are provided in each valve chamber 61, and both ports 63 and 64 each have a dedicated solenoid 6.
Valve bodies 69, 70 are provided with valve bodies 5, 66 and are pressed in the closing direction by springs 67, 68. In particular, the diaphragm 71 of the valve body 69 for the pressurization source
is formed wider than the other diaphragm 72 in order to make the pressure receiving surface when opened larger than when closed. Then, when pressurizing, only the solenoid 65 is momentarily excited, and when the pressure is being reduced, only the solenoid 66 is momentarily excited.

In the embodiment shown in FIG. 2, the solenoid 26 is not shared, but dedicated solenoids are provided for the plungers 27 and 27', so that the plunger 27 is operated during pressurization and the plunger 2 is operated during depressurization.
7' can also be activated instantaneously.

As is clear from the above explanation, once the valve element is opened according to the present invention, its pressure-receiving surface becomes larger in the valve chamber, so that it remains open even when the solenoid is not energized at a pressure higher than a predetermined pressure, and other valves By self-maintaining the open state until the pressure inside the valve chamber is instantaneously reduced by the body, high-speed pressurization can be performed on the load connected to the valve chamber with a small amount of electric power.

[Brief explanation of drawings]

Fig. 1 is a principle diagram of a conventional pressure switching solenoid valve, and Fig. 2 is a longitudinal cross-sectional view of a pressure switching solenoid valve according to the present invention.
FIG. 3 shows an application example of the solenoid valve according to FIG. 2, and FIG. 4 shows another embodiment of the invention. 18, 18', 63, 64: Port, 12, 1
2', 61: Valve chamber, 21, 21', 69, 70: Valve body, 23, 23', 71, 72: Diaphragm,
26, 65, 66: Solenoid.

Claims (1)

[Claims for Utility Model Registration] (1) A valve chamber having a load port, a pressure source port, and a valve body driven by a solenoid to open the pressure source port, the pressure source port Once opened within a predetermined pressure range, the pressure-receiving surface of the valve body that is effective for opening the valve body becomes wider than when it is closed to the extent that it can maintain the open state against the spring force; 1. A pressure switching solenoid valve, characterized in that it is connected to a low pressure source by a separate valve element that is common to the solenoid or is driven by another solenoid. (2) Utility model registration claim 1, characterized in that the other valve element is provided in another valve chamber that communicates with the valve chamber, and is driven by a common solenoid with the valve element. The pressure switching solenoid valve described. (3) The pressure switching solenoid valve according to claim 1, wherein the other valve element is provided in a common valve chamber with the valve element, and further includes another solenoid.