JPS6229737Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a solenoid valve that switches fluid flow paths.

As a conventional solenoid valve, the output pressure of the first three-way switching valve is used as pilot pressure to drive the valve body of the second three-way switching valve, so that the entire valve functions as a four-way switching valve. Those configured as follows are publicly known.

However, in the above electromagnetic valve, when the piston packing, which is driven using the output pressure of the first three-way switching valve as pilot pressure, and the valve body, which is switched and driven by the piston packing, are integrated, the following problem occurs. be. That is, in order to start the piston seal from a stationary state, it is necessary to overcome not only the starting resistance of the piston seal itself but also the starting resistance of the valve body.
Therefore, the starting resistance as a whole becomes extremely large, and unless the output pressure (pilot pressure) from the first three-way valve is made sufficiently large, the second
However, there was a problem in that the piston packing and valve body in the three-way switching valve could not be stably driven, or the fluid flow path could not be switched by driving them.

The present invention provides a solenoid valve that can reliably switch the fluid flow path in the second three-way valve described above even when the output pressure from the first three-way valve is relatively small. This is what we are trying to provide.

In order to achieve this purpose, the solenoid valve of the present invention includes a first three-way switching valve driven by a solenoid, and a second three-way switching valve driven by applying its output pressure as pilot pressure. The second three-way switching valve includes a piston packing driven by the pilot pressure and a valve body that is switched and driven by the piston packing to switch the output port into communication with the input port and the exhaust port. The valve body is constructed by engaging the piston seal and the valve body through mutually movable play in the axial direction.

In the solenoid valve of the present invention, only the piston seal in the second three-way valve is first driven by the output pressure from the first three-way valve, and after the piston seal has stroked by the amount of play described above, the valve body is moved. It will hit and drive it,
The fluid flow path in the second three-way valve is thereby switched.

As described above, according to the solenoid valve of the present invention, there is no need to shake off the starting resistance of the piston seal and the valve body at the same time, and therefore, the small output pressure from the first three-way valve can be used to control the second three-way valve. can be switched reliably and with good response. In other words, in order for the piston seal to start, it only needs to overcome its own starting resistance and does not need to overcome the starting resistance of the valve body.Therefore, the piston seal starts with good response and reliably, and then the piston seal engages the valve body. However, since the piston packing is supported by inertia, the valve body can be easily driven against the starting resistance.

Therefore, if the pressure-receiving area of the piston packing is made the same as that of the conventional one, the pressure of the supplied fluid can be lowered, and the working pressure range of the supplied fluid can be widened. When the pressure is made equal to that of a conventional valve, the piston packing has a small pressure-receiving area, and the entire valve can be downsized. Further, since the piston packing and the valve body are engaged with each other without being completely separated, the postures of both can be properly maintained before and after switching and during the switching process by mutual cooperation.

Hereinafter, embodiments of the present invention will be described in detail based on the drawings. In FIGS. 1 and 2, 1 is a solenoid, 2 is a valve part, and the fluid flow path in the valve part 2 is caused by the excitation and demagnetization of the solenoid 1. can be switched.

The solenoid 1 has a bobbin 4 wound with an excitation coil 3, and a fixed iron core 5 is fitted and fixed into a hole 4a at the center of the bobbin 4, and a movable iron core 6 biased by a return spring 7 is slidably inserted. It is fitted.

On the other hand, the valve body 10 of the valve section 2 has a fluid input port 11, first and second output ports 12, 1
3, and first and second exhaust ports 14 and 15. Thus, in the first three-way switching valve, the valve body 17 that moves toward and away from the valve seat 16 provided on the first input path 11a from the input port 11 is connected to the movable iron core 6.
The movable core 6 is attached to the valve chamber 18, and the valve chamber 18 and the first output port 12 are communicated with each other, and the valve chamber 18 is opened to the atmosphere through a passage in the fixed core 5. The valve seat 21 is connected to the first exhaust port 14 and is provided at the inner end of the flow path within the fixed core 5.
It is constructed by providing the movable iron core 6 with a valve body 22 that moves toward and away from the movable core 6. This first 3-way switching valve obtains an output pressure at the first output port 12, and this output pressure is also used as a pilot pressure for the second 3-way switching valve. It drives the valve body 30 of the one-way switching valve, and therefore the valve chamber 18 is communicated with the piston chamber 31 of the second three-way switching valve.

The second three-way switching valve is provided with a valve body 30 made of an elastic body in a valve chamber 33 with which the second input path 11b from the input port 11 communicates.
is a valve seat 34 provided in a flow path from the input path 11b to the second output port 13, and a valve seat 34 provided in the flow path from the input path 11b to the second output port 13.
The valve seat 35 is placed in contact with and separated from a valve seat 35 provided in a flow path leading to an exhaust port 15, and one side is opened while the other is closed. Then, one end of this valve body 30 is connected to the piston seal 36 which is driven by the output pressure of the first three-way switching valve within the piston chamber 31.
They are engaged through mutually movable play in the axial direction.

That is, the valve body 30 includes a connecting rod 30a having an enlarged portion 30b at its tip, and the expanded tip 30b of the connecting rod 30a is press-fitted into a locking hole 36a formed in a piston packing 36 made of an elastic material. By engaging in a locking state, the stroke a
Stretched state separated by (≒b) (see Figure 1)
and the shortened state where they come into close contact with each other (see Figure 2)
Therefore, the stroke a functions as play between the piston packing 36 and the valve body 30.

Next, the operation of the solenoid valve having the above configuration will be explained.

In the demagnetized state of the solenoid 1, as shown in FIG.
1a is closed, the pressure fluid at the first output port 12 is discharged from the first exhaust port 14 via the valve chamber 18, and the fluid flowing from the input port 11 to the second input path 11b is discharged from the valve chamber 33. It is guided to the second output port 13. That is, in the demagnetized state of the solenoid 1, the movable core 6 is separated from the fixed core 5 by the biasing force of the return spring 7, the valve body 17 closes the valve seat 16, and the valve body 22 closes the first exhaust port. 14 is opened. Therefore, the valve chamber 18
The fluid inside flows out from the first exhaust port 14 and the pressure decreases, and the pressure in the piston chamber 31 also decreases, so the piston seal 36 moves to the upper position in FIG. 1 due to its own elastic restoring force. The valve body 30 is pulled up to open the valve seat 34, and the valve seat 3
5, the fluid coming in from the second input channel 11b is delivered through the second output port 13.

When the solenoid 1 is energized, it is switched to the state shown in FIG. That is, by the excitation of the solenoid 1, the movable iron core 6 is attracted to the fixed iron core 5, and the valve body 17 opens the valve seat 16, and the valve body 2
2 closes the valve seat 21, so that fluid from the input port 11 is supplied to the first output port 12 through the valve chamber 18. Further, since the fluid pressure in the valve chamber 18 is introduced into the piston chamber 31, the piston seal 36 bulges downward and absorbs the stroke a as the play, and then presses the valve body 30 and moves downward. let me,
As a result, the valve body 30 closes the valve seat 34 and simultaneously opens the valve seat 35. Therefore, the fluid in the second output port 13 is discharged from the exhaust port 15 through the valve chamber 33 and the valve seat 35.

After this, if the solenoid 1 is demagnetized, the state shown in FIG. 1 is restored.

Thus, when the piston packing 36 and the valve body 30 are switched from the state shown in FIG. 1 to the state shown in FIG. 2, the switching is reliably performed by a slight increase in pressure in the piston chamber 31. That is, when the solenoid 1 is energized, the pressure in the valve chamber 18 and the piston chamber 31 increases as the valve seat 16 opens, and the piston seal 36 bulges downward due to the increase in pressure. Since it is only necessary to overcome the starting resistance of Furthermore, after the piston seal 36 is displaced by the stroke a as the play, the piston seal 36 hits the valve body 30 and the two stroke together as one, but the piston seal 36 is moved by the inertia force. Because it hits the body 30,
The starting resistance of the valve body 30 is easily overcome, and the valve body 30 is easily driven by the piston packing 36.

FIG. 3 shows a different embodiment of the invention. That is, in the embodiment shown in FIGS. 1 and 2, the peripheral edge of the piston packing 36 is supported by the valve body, but the piston packing 41 in the embodiment shown in FIG. It is slidably inserted. Note that the other configurations are substantially the same as those of the embodiment described above, and accordingly, the same parts are denoted by the same reference numerals and the description thereof will be omitted.

Further, the valve body 30 in the second three-way switching valve in the above embodiment is entirely made of an elastic body, but as shown in FIG. The valve body 45 can also be constructed by integrally attaching a sheet member 44 made of a material by baking or other means.

FIG. 5 shows a different connection means between the piston seal and the valve body, which is opposite to the above embodiments.
A connecting rod 47a is provided protrudingly on the piston packing 47, and an engagement hole 48a is provided on the end surface of the valve body 48.
These strokes a (≒
b) They are engaged with a movable play.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an embodiment of the present invention in a non-energized state, Fig. 2 is a sectional view of the energized state, Fig. 3 is a sectional view of main parts of a different embodiment of the invention, and Fig. 4 is a valve body. FIG. 5 is a partial sectional view showing different engagement states of the piston packing and the valve body. 1... Solenoid, 30... Valve body, 36... Piston seal.

Claims (1)

[Scope of utility model registration request] A first three-way switching valve driven by a solenoid and a second three-way switching valve driven by applying its output pressure as pilot pressure, the second three-way switching valve The piston packing is driven by the pilot pressure and the valve body is switched and driven by the pilot pressure to switch the output port to the input port and the exhaust port, and the piston packing and the valve body are connected to the shaft. A solenoid valve characterized in that the solenoid valve is engaged through play so as to be mutually movable in directions.