JPH0333566A - Digital valve - Google Patents

Abstract

PURPOSE:To get a digital valve, whose orifice is easy to manufacture and has a shape accurately matched to a resolution of the valve, by fixing an orifice plate removably and tightly inside a valve port which forms an element valve, and by providing an orifice in the orifice plate. CONSTITUTION:A valve seat 2 is screwed into a screw hole 11 provided on a partition wall 1 through an O-ring 12. The valve seat 2 has a screw hole 21 inside its port at its upper side. An orifice plate 3 is screwed into the screw hole 21. A clearance between the orifice plate 3 and the valve seat 2 is sealed tightly by placing an O-ring 4 between an end face of the orifice plate 3 and the valve seat 2. The orifice plate 3 has an orifice 31, whose sectional area is determined so as to correspond to the respective element valves. Because the orifice plate 3 can be mounted and dismounted easily to the valve seat 2, repairs and changes of the orifice 31 can be performed easily. Consequently, the orifice 31 is always kept as the best one.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a binary digital valve, and more particularly to an orifice structure of an element valve of a binary digital valve.

[Conventional structure] A conventional binary digital valve is, for example, a time-opening valve 63-96.
There is a device shown in FIG. 6 disclosed in Japanese Patent No. 366.

In this device, a plurality of on-off valves are provided on the partition wall that partitions the upstream liquid pool and the downstream liquid pool, and the area ratio of the orifices of the on-off valves is set to 2°l 2'l 2"l...2" −°
It is set in the geometric progression. In a digital valve formed in this way, it is necessary to accurately manufacture the orifice cross-sectional area, and an error of ±1% in diameter causes an error of approximately 12% in cross-sectional area, which affects the resolution of the digital valve. For example, in an 8-bit digital valve, the resolution is theoretically 1/255, but in this case, the accuracy of the maximum diameter orifice must be at least 17,510 times the diameter.

In the conventional digital valve described above, the orifice is integrally provided with the valve seat, as shown in FIG. 7, and if the accuracy of the orifice is inadequate, it is replaced together with the valve seat.

[Problems to be Solved by the Invention] In this way, the orifice that is integrated with the valve seat requires precision manufacturing of the orifice as well as the sealing surface of the valve seat with the valve body, and a special jig is required to fix the valve seat. It takes a lot of time and effort to manufacture. Further, if heat treatment or surface treatment is applied to harden the orifice in order to minimize wear, this will have an adverse effect on the sealing surface of the valve seat, such as dimensional changes, so additional processing such as polishing will be required.

Further, even during use of the valve, due to any abnormality such as wear of the orifice or wear of the valve seat surface, the orifice, which is integrally constructed with the valve seat, must be replaced, which is inconvenient.

The present invention aims to solve the above problems.

[Means for Solving the Problems] In order to solve the above problems, the digital valve of the present invention has N (N≧2
) element valves are provided, and the orifice opening area ratio of the element valves is a geometric progression of 2° 2", 2N...2N
-'' is a binary digital valve, characterized in that an orifice plate is replaceably sealed and fixed in a valve port forming the element valve, and the orifice is provided in the orifice plate.

[Function] As the present invention has the above configuration, the orifice is formed on the orifice plate and is sealed and fixed in a replaceable manner within the valve opening. Therefore, the orifice can be easily manufactured and manufactured with high precision, and can match the resolution of the valve. Orifice shape can be obtained.

In addition, since it is provided separately from the valve seat, it can be made of materials such as ceramics or sintered metal, which have excellent wear resistance, and can be manufactured regardless of the material of the valve seat. Furthermore, since it can be easily replaced, the orphis can be easily repaired, and the highly accurate resolution of the digital valve can be maintained at all times.

[Example] Embodiments of the present invention will be described below based on the drawings.

The present invention relates to an orifice that communicates between an upstream liquid pool and a downstream liquid pool, and the overall structure of the digital valve is the same as the conventional one, so a description thereof will be omitted.

FIG. 1 shows a first embodiment, in which a partition wall l is provided with an internal thread II, and a valve seat 2 is attached to this internal thread II via an O-ring 12. The inner surface of the valve opening of the valve seat 2 has a female thread 21 from the upper side of the figure, and the orifice plate 3 is attached to this female thread 21.
It is installed by screwing them together. An O-ring 4 is sandwiched between the end of the orifice plate 3 and the valve seat 2, and the space between the orifice plate 3 and the valve seat 2 is sealed. The orifice plate 3 is provided with an orifice 31. The cross-sectional area of this orifice 31 is set to a size necessary for each element valve. In this way, the orifice plate 3 can be easily attached to and removed from the valve seat 2, so the orifice 31 can be easily repaired or replaced, and can always be maintained at the best orifice position.

FIG. 2 shows a second embodiment, in which a valve seat 2 is screwed to the partition wall 1 on the second side of the figure, as in the first embodiment. A notch 5 having a female thread 51 is provided downstream of the valve port 32 of the partition wall 1, and an orifice plate 3 is sealed and fixed in the notch 5 via an O-ring 4 by screwing an orifice plate holder 6. has been done. The orifice plate 3 is provided with an orifice 31 in the same manner as described above, and the orifice plate 6 is provided with a hole having a larger diameter than the orifice 31. In the case of this embodiment, the orifice plate 3 is screwed together with the orifice plate retainer 6.
is hermetically fixed to the bulkhead 1, so the orifice plate retainer 6
The orifice plate can be easily replaced by attaching and removing the orifice plate, and as in the previous embodiment, the best orifice can always be maintained.

FIG. 3 shows a third embodiment, in which a notch 22 is provided on the inner surface of the valve opening at the end of the valve seat 2, and an orifice plate 3 is installed in this notch 22 via a seal ring 4. It is screwed onto the female thread 11 of the partition wall l.

The orifice plate 3 is provided with an orifice 31, and in this case, the orifice 3I is replaced by removing the valve seat 2 from the partition l.

FIG. 4 shows a fourth embodiment, in which the valve seat 2 is also
A notch 23 is provided on the inner surface of the end valve port, and an orifice plate 3 is installed in this notch 23 via a seal ring 4. The orifice plate 3 is hermetically fixed to the valve port 32 by screwing and fastening the presser foot 6. In this case, the orifice plate 3 can be easily replaced by removing the orifice holder 6 from the lower part of the partition wall l.

FIG. 5 shows a fifth embodiment, in which the valve seat 2 is also
A notch 23 is provided on the inner surface of the valve opening at the end of the valve seat 2, and the orifice plate 3, which is screwed into the internal thread 24 of the notch 23, is screwed into the notch 23 via the seal ring 4. The orifice plate 3 is hermetically fixed within 32. The orifice 31 is provided on the orifice plate 3, and by removing the orifice plate 3 from the valve seat 2, the orifice can be easily replaced or repaired.

In the embodiments shown in FIGS. 1 to 5, the orifice 31 provided in the orifice plate 3 may be formed into a plurality of orifices to provide the optimum orifice for each element valve.

[Effects of the Invention] As explained in section 2 below, in the digital valve of the present invention, the orifice can be easily replaced and repaired, and since the orifice is provided on the orifice plate, it is easy to process, and the orifice can be manufactured accurately and with high precision. , and each element valve can be provided with the best orifice. Furthermore, it is easy to form the orifice using a material with excellent wear resistance and heat change resistance, making it possible to obtain a digital valve with high precision resolution without affecting the valve seat as in conventional valves. .

[Brief explanation of drawings]

Figures 1 to 5 show embodiments of the present invention, and are sectional views of the valve seat portions of each element valve, Figure 6 is a sectional view of a conventional digital valve, and Figure 7 is the element valve of Figure 6. It is a sectional view of the valve seat part in . l...Bulkhead, 2...Valve seat. 3... Orifice plate, 4... Seal ring. 5... Notch, 6... Orifice plate holder. 31... Orifice, 32... Valve. JP-A-3-33566 (4) Figure 2 Figure □ Figure 7

Claims (1)

[Claims] 1) N (N≧2) on the partition wall separating the upstream and downstream liquid pools
) element valves are provided, and the opening area ratio of the orifice of the element valves is a geometric progression 2^0, 2^1, 2^2,...
2^N^-^1, which is a binary digital valve, characterized in that an orifice plate is hermetically fixed in a replaceable manner within a valve port forming the element valve, and the orifice is provided on the orifice plate. . 2) The digital valve according to claim 1, wherein the orifice plate provided with the orifice is screwed to the inner surface of the valve opening of the valve seat forming the element valve. 3) The digital valve according to claim 1, wherein the orifice plate provided with the orifice is clamped within the valve port of the partition wall by an orifice holder screwed to the inner surface of the valve port formed in the partition wall. . 4) In claim 1, it is stated that the orifice plate provided with the orifice is sandwiched between the valve port end of the valve seat forming the element valve and the notch step formed in the partition wall. Features a digital valve. 5) The digital valve according to claims 1 to 4, wherein a plurality of the orifices are provided on the orifice plate.