JPS6396368A - Digital valve - Google Patents

Abstract

PURPOSE:To prevent that a part of a valve body is torn off to make dust to clog an orifice, by forming the orifice at the upper side of a valve seat and a ring-formed projection with the diameter larger than the orifice diameter at the lower side of the valve body. CONSTITUTION:A valve body 3 fixed at the tip of a plunger 4 is made of an elastic material of a synthetic rubber or the like. The lower end surface of the valve body 3 contacts to or separates from the upper end surface of a valve seat 6 by the up and down movement of the plunger 4, and at the lower end of the valve body 3, is formed a ring-formed projection 6 with the inside diameter larger than the diameter of an orifice 7 of the valve seat 6. Since the diameter of the ring-formed projection 16 is larger than that of the orifice 7, the periphery of the orifice 7 is never squeezed and depressed by the valve body 3.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a binary digital valve, which is a type of control valve used for fluid process control, and particularly relates to improvements in the valve body and valve seat portion. be.

[Conventional technology]

The binary digital valve is described in the literature (magazine "Instrument" 1985
Year, Volume 28. N11l 2. pp26-30 and "Piping Technology J 1986, 1. pp156-159
), it consists of a plurality of element valves (let's say N), and these element valves operate fully open or fully open, and the cross-sectional area ratio of the orifice that defines the flow path of each element valve is , 2° , 21=22 :・・・・・・：2
This is point 1. This is also called an N-bit digital valve. This digital valve has the characteristic that the larger the bit number N, the higher the resolution.

FIG. 2 shows an example of a conventional 4-bit digital valve consisting of, for example, four element valves. Both sides of the extreme end of the valve body 1 are connection ports for connecting to other piping parts.

Here, the connection port on the right side is the inflow port 10 on the inflow side, and the connection port on the left side is the outflow port 11 on the outflow side. An inflow passage 8 formed in the middle of the valve body 1 communicates with an inflow port 10, and an outflow passage 9 formed in the middle of the valve body 1 communicates with an outflow port 11. A partition wall 13 is formed between the inflow channel 8 and the outflow channel 9, and this partition wall 13 has four through holes, each of which has a valve seat 6 (6a, 6b). , 6 c, 6 d) Fitted or screwed. Each of the valve seats 6 has an orifice 7 whose cross-sectional area determines the amount of fluid through which the digital valve passes and is a binary isostop number. In other words, the ratio of the cross-sectional areas of each orifice is 2°:2':
2”:2” (1:2:4:8).

The plunger 4 is moved up and down by an actuator 2 containing a solenoid 5 and a spring 20, and a valve body 3 made of an elastic material is attached to the lower end of the plunger 4. When this valve body 3 is in contact with the aforementioned valve seat 6, the element valve is closed, and when they are apart, the element valve is open. Each element valve assumes either a closed or open state as each plunger 4 moves up and down. Since the orifice cross-sectional area ratio of each of the four element valves is 1:2:4:8,
By opening and closing each element valve, this digital valve changes from fully closed to 1.2.3,4,5°6,...13,
The orifice cross section can be up to 14.15 (1+2+4+8).

Next, the control system of the digital valve (not shown in the drawing) generally detects the flow rate after the outlet 11, compares this signal with a set value, and converts this result into a digital signal. This signal is used to control the plunger 4 by moving it to either the closed or open position via the actuator 2, which is called feedback control.

As described above, with this digital valve, not only precise flow rate control but also constant pressure, constant flow rate, etc. control can be easily performed.

Next, in order to make it easier to machine the orifice of the valve seat for element valves whose orifice diameter is small, measures as shown in FIG. 3 are taken. That is, in order to reduce the axial thickness of the orifice 7 of the valve seat 6, a hole 14 larger than the diameter of the small diameter orifice is formed below the orifice 7; It is thin and easy to process.

[Problem that the invention seeks to solve]

In the conventional digital valve as described above, the valve body 3 of each element valve is pressed against the valve seat 6 to be in a closed state. Here, in an element valve in which the orifice 7 of the valve seat 6 has a small diameter, the thickness of the orifice 7 of the valve seat 6 is also small. If the valve body 3 is repeatedly pressed against the peripheral part of the orifice 7 of the thin valve seat 6, crimped and separated, the peripheral part of the orifice 7 may be slightly dented, and if dented, the effective diameter of the orifice 7 will change. There is a problem. Further, the valve body 3 is made of an elastic material, and when the valve body 3 is pressed against the valve seat 6 and crimped to completely close the element valve, the valve body 3 sinks into the orifice 7 as shown in FIG. A situation occurs. If this condition is repeated, the lower surface of the valve body 3 will be locally subjected to a large load, causing that portion to tear or deteriorate. There is a problem in that a part of the torn valve body 3 becomes dust and blocks the orifice 7.

An object of the present invention is to obtain a digital valve that eliminates the above-mentioned problems.

[Means for solving problems]

The present invention has an inflow port and an outflow port at both ends, and an inflow channel communicating with the inflow port in the middle portion, and an outflow channel communicating with the outflow port separated from the inflow channel by a partition wall. A plurality of through holes are formed in the valve body and the partition wall to communicate the inflow channel and the outflow channel, a valve seat is attached to each of the plurality of through holes, and a valve body made of an elastic material is fixed to the lower tip. and a plurality of plungers that cause the valve body to come into contact with the valve seat by moving up and down, and each valve seat has a cross-sectional area on its upper surface that regulates the flow rate. The digital valve is characterized in that an orifice is formed therein, and the annular projection having an inner diameter larger than the diameter of the orifice is formed on the lower surface of the valve body of each of the plungers.

〔Example〕

FIG. 1 shows an embodiment of a digital valve according to the present invention, and is an enlarged sectional view showing a valve seat 6 and a valve body 3.

The parts of the digital valve not shown in FIG. 1 are the same as the conventional example shown in FIG. Therefore, in this embodiment as well, the element valves are four 4-pinto digital valves.

The valve seats 6 and valve bodies 3 shown in FIG.
, 3c, and 3d. Further, the orifice diameter of each element valve is the same as that in the conventional example.

In FIG. 1, the valve seat 6 is fitted into a through hole in the partition wall 13, and an O-ring 12 is attached to the top of the through hole in the partition wall 13 to seal between the partition wall 13 and the valve seat 6.

The outer diameter of the valve seat 6 forms a step, the lower part of which is the partition wall 1.
The fitting part fits into the through hole 3, and the upper part thereof has a larger diameter than the lower part and projects from the upper surface of the partition wall 13. The inner surface of the valve seat 6 has an orifice 7 at its upper part, and has a length in the axial direction that allows easy drilling of the orifice. The lower part is a hole 14 with a large orifice diameter.
The orifice 7 and the large hole 14 are in continuous contact with each other.

A valve body 3 is fixed to the lower end of the plunger 4, and the plunger 4 is moved up and down by an actuator 2 having a built-in solenoid 5 and a spring 2o, similar to the conventional digital valve shown in FIG.

Normally, the plunger 4 is pushed downward by the spring 20, and the valve body 3 is in a state of being pressed against the valve seat 6, that is, in a closed state. When the solenoid 5 is energized, the electromagnetic force of the solenoid 5 overcomes the pressing force of the spring 20 and the plunger 4 rises. At this time, this element valve is in an open state.

When the solenoid 5 is de-energized, the electromagnetic force disappears, the plunger 4 is lowered by the force of the spring 20, and the element valve is in an open state.

The valve body 3 fixed to the tip of the plunger 4 is made of an elastic material such as synthetic rubber or fluorine resin. The lower end surface of the valve body 3 comes into contact with and separates from the upper end surface of the valve seat 6 as the plunger 4 moves up and down, and there is an annular projection at the lower end of the valve body 3 whose inner diameter is larger than the diameter of the orifice 7 of the valve seat. 16
form.

In the digital valve of the embodiment described above, when each element valve is closed, the annular projection 16 of the valve body 3 and the valve seat 6 are pressed into contact with each other. The diameter of the annular projection 16 is the orifice 7.
Since the diameter of the orifice 7 is larger than the diameter of the valve body 3, the peripheral portion of the orifice 7 does not come into contact with the valve body 3.

Therefore, the peripheral portion of the orifice 7 is not pressed by the valve body 3, so that it is not dented. Further, since the peripheral corner of the orifice 7 and the lower surface of the valve body 3 made of an elastic material are not locally pressed, a part of the valve body 3 will not be torn off, and the orifice 7 will not be blocked by this dust.

〔Effect of the invention〕

As described above, the present invention has the advantage that the effective diameter of the orifice does not change and a portion of the valve body does not break off and turn into dust, blocking the orifice.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of a valve body and valve seat portion of a digital valve showing an embodiment of the present invention, and FIG. 2 is a sectional view showing an example of a conventional digital valve. FIG. 3 is an enlarged sectional view showing the valve body and valve seat portion of a conventional digital valve. Figure 1 14 Large hole Figure 3

Claims (1)

[Claims] 1. An inlet channel having an inlet and an outlet at both ends, an inlet channel communicating with the inlet in the middle, and an outlet communicating with the outlet separated from the inlet channel by a partition wall. a valve body having a flow path, a plurality of through holes formed in the partition wall to communicate the inflow flow path and the outflow flow path, a valve seat attached to each of the plurality of through holes, and a lower tip made of an elastic material. A digital valve comprising a plurality of plungers that fix the valve body and move the valve body up and down to cause the valve body to come into contact with or separate from the valve seat, and each of the valve seats has a valve on its upper surface that regulates the flow rate. A digital valve characterized in that an orifice having a cross-sectional area of 2. The digital valve according to claim 1, wherein the valve body is made of an elastic material, and the valve seat is made of metal or ceramic.