JP4384924B2 - Membrane gas meter rotary valve - Google Patents

Description

  The present invention relates to an improvement in planar accuracy of a bottom surface of a rotary valve of a membrane gas meter, that is, a contact surface with a valve seat.

  First, the operation principle of the membrane gas meter will be described. As shown in FIG. 6, the gas passes through the rotary valve 3 and the distribution chamber 4 from the inlet 2 of the meter body 1 and enters one of the front and rear measuring chambers 5. Since each measuring chamber 5 is divided into a front chamber 7 and a rear chamber 8 by a membrane 6, the gas in the chamber into which the gas has entered widens due to the movement of the membrane due to the pressure difference, while the gas in the chamber narrowed due to the movement of the membrane. Is discharged again to the outlet 9 through the distribution chamber 4 and the rotary valve 3. As shown in FIGS. 8 and 9, a blade 10 is connected to the membrane 6, and the reciprocating motion of the membrane 6 is changed to the swing motion of the blade 10 in the measuring chamber 5, and then the link mechanism outside the measuring chamber 5. 11 and the rotary valve 3 is rotated by the link mechanism. The rotation of the valve 3 is transmitted to the counter unit 13 via the crankshaft 12, the counter unit 13 counts the rotation, and finally the meter indicating unit (not shown) is driven. Further, as shown in FIG. 6, when the rotary valve 3 rotates by a predetermined angle in accordance with the movement of the link mechanism 11, the way of communication between the rotary valve 3 and the distribution chamber 4 is changed, and the measuring chamber 5 communicating with the inlet 2 is changed. The room is switched and the room communicating with the exit 9 is switched. Accordingly, the room in which the gas enters and exits changes in the order of (a) to (d) in FIG. 6 and FIG. 7 as the gas is used, and the front and rear membranes reciprocate in sequence. Is done. 6 and 7 correspond to each other.

  As described above, the rotary valve 3 for switching the gas path to the measuring chamber is provided on the distribution chamber 4. As shown in FIG. 10, the rotary valve 3 rotates in contact with a valve seat 14 formed on the distribution chamber side. As shown in FIG. 11, a gate 16 for guiding gas to the metering chamber is provided on the outer portion of the bottom plate 15. Is formed in a relay chamber 18 that opens downward from the central portion of the bottom plate 15 to the opposite side of the gate 16 and the inside of the raised portion 17. It is. In the relay chamber 18, a portion corresponding to the opposite side of the gate is a relay inlet 19, and a portion corresponding to the center portion of the bottom plate is a relay outlet 20. On the other hand, as shown in FIG. 3 or 10, the valve seat 14 has a concentric seal portion 21 bulging immediately below the rotary valve 3, and the outer peripheral portion of the seal portion 21 is radially divided every 90 degrees. The distribution port 22 communicating with each of the four chambers of the measuring chamber is formed, the central portion of the seal portion 21 is used as the intake port 23, and the gas from the gate 16 of the rotary valve is taken in from any of the four distribution ports 22 The metered gas is sent from another distribution port 22 to the relay inlet 19 of the rotary valve, and the gas discharged downward from the relay outlet 20 is guided to the outlet 9 of the meter body through the intake port 23. Reference numeral 24 is a flow path extending from the lower side of the distribution port toward the gas outlet.

By the way, since negative pressure is generated in the measuring chamber when the gas is used, the bottom surface of the rotary valve rotates in close contact with the seal portion of the valve seat. Therefore, it is required to stabilize gas metering by reducing the contact area with the seal portion to reduce the driving force required to rotate the rotary valve and to reduce the gas pressure loss as much as possible. In the conventional rotary valve, as shown in FIGS. 10 and 11, the arc portion 25 surrounding the outer periphery of the gate is thinned by scraping the bottom surface to reduce the driving force. Incidentally, the present applicant knows the above prior art, but does not know the location of the information. Then, the above-mentioned conventional example was searched by FI / F term search in the electronic library of the JPO, but the same one was not found. The search conditions were: material type: patent, theme: 2F030, condition: G01F3 / 22 @ A. The number of hits was 151, and 78 cases were released until 1993. The closest ones are listed below.
Japanese Patent Laid-Open No. 2002-122462 (FIG. 2) Japanese Patent Laid-Open No. 05-164589 (FIG. 2) JP 2003-65822 A (FIG. 12)

  However, as shown in FIG. 11 (b), if only a part of the entire outer circumference of the bottom surface of the bottom plate, that is, only the arc portion 25 is formed thin, that portion of the bottom surface floats more than the other portions. . If this happens, when the rotary valve is picked and the bottom surface is lapped, there is a possibility that the bottom surface will be lapped in a slightly tilted state due to the thin part. It becomes easy.

  The present invention has been developed in view of the above circumstances, and the problem to be solved is to improve the planar accuracy of the bottom surface by lapping by making a structure of the rotary valve, and to make gas difficult to leak.

  The rotary valve of the present invention comprises a circular bottom plate and a raised portion that rises upward from the bottom plate. The bottom plate is brought into contact with a concentric seal portion of the valve seat, and a fan-shaped gate is vertically arranged on the outer peripheral side of the bottom plate. It is formed so as to penetrate, and a raised portion is formed on the opposite side of the gate from the center of the bottom plate, and the inside of the raised portion is formed in a relay chamber that opens downward, corresponding to the opposite side of the gate in the relay chamber. The part is used as a relay inlet, the part corresponding to the center of the bottom plate in the relay chamber is used as a relay outlet, and the gas taken in from the meter main body flows into one of the four distribution ports on the outer peripheral side of the seal part through the gate. The gas discharged from another distribution port is temporarily taken into the relay chamber via the relay inlet, discharged from the relay outlet to the intake port inside the seal portion, and finally the gas is directed to the outlet of the meter body. It assumes shall.

  And the circular arc part surrounding the outer periphery of the gate of the bottom plate is formed by floating the inner peripheral side corresponding to directly above the seal part from the seal part, and the outer peripheral side is continuous with the contact surface to the seal part. Are formed in the same plane.

  In the present invention, since the outer peripheral side of the bottom surface of the arc portion is formed in the same plane as the contact surface to the seal portion, the same plane is continuous with the entire circumference in the circumferential direction of the bottom surface of the circular bottom plate. It becomes easy to lapping the plane of the bottom plate, the plane accuracy is improved as compared with the conventional one, and gas is less likely to leak.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that components having the same functions as those of the conventional example are denoted by the same reference numerals. The basic configuration and operating principle of the membrane gas meter are the same as those of the conventional example already described.

  As shown in FIG. 8, the valve seat 14 serves to partition the upper space and the lower space (metering chamber) in the meter body 1, and as shown in FIG. 1, FIG. 2, or FIG. A concentric seal portion 21 composed of a circle 27 protrudes upward, and the space between the inner circle 26 and the outer circle 27 is partitioned by a partition 28 every 90 degrees to form four fan-shaped distribution ports 22. Mouth 22 leads to a separate room in the weighing chamber. The inside of the inner circle 26 is an intake port 23, and the flow channel 24 extends from the lower side of the intake port 23 to the side (the right side in FIGS. 2 and 3), and the flow channel 24 passes just below the distribution port 22. The gas eventually leads to the outlet 9 of the meter body. A cylindrical lower receiving portion 30 is provided at the center of the inner circle 26 to accommodate and support the lower portion of the shaft 29, and the rotary valve 3 can be rotated at the upper portion of the shaft 29 protruding upward from the lower receiving portion 30. To support. Further, since the connecting piece 31 extends radially from the lower receiving portion 30 toward the inner circle 26, the intake port 23 is divided into three when viewed in plan, but as shown in FIG. Since the height width of the piece 31 is shortened, all sections are in communication with each other below.

  As shown in FIG. 1, FIG. 4 or FIG. 5, the rotary valve 3 is formed such that the diameter of the circular bottom plate 15 is slightly larger than the outer circle 27 of the valve seat. The gate 16 having a shape corresponding to the opening 22 opens in a fan shape opened 90 degrees, and a raised portion 17 is formed on the opposite side of the gate 16 from the center of the bottom plate 15, and the inside of the raised portion 17 faces downward. It is formed in the relay chamber 18 that opens to the center. When viewed from the bottom, the relay chamber 18 has a portion corresponding to the opposite side of the gate 16 as a relay inlet 19 having a shape corresponding to the distribution port 22, while a portion corresponding to the central portion of the bottom plate 15 is a valve seat intake port. The relay outlet 20 has a shape corresponding to 23. Reinforcing ribs 32 extend radially on the upper surface of the raised portion 17 and on both sides of the gate 16 in the circumferential direction.

  As shown in FIG. 4, the raised portion 17 has an upper receiving portion 33 that rotatably accommodates the upper portion of the shaft 29, and an engaging portion 34 that is associated with the link mechanism 11. More specifically, an upper receiving portion 33 and an engaging portion 34 that are recessed stepwise from a portion corresponding to the shaft 29 toward a part of the outer periphery are continuously formed on the upper surface of the raised portion 17. The portion 33 is formed in a cylindrical shape, and the engaging portion 34 is formed in a groove shape. In the bottom of the upper receiving portion 33, there is provided a through hole 35 penetrating vertically through the upper portion of the shaft 29. As shown in FIG. 29 is inserted in a state of surrounding. Further, the crank 36 projects a rotating piece 38 laterally from the sleeve 37 and the rotating piece 38 is inserted into the engaging portion 34, and the movement of the membrane 6 due to the use of gas is transferred from the link mechanism 11 to the rotating piece 38. The rotary valve 3 is rotated instead of rotating. In the crank 36, a gear 39 at the upper end of the sleeve 37 meshes with the gear 40 of the counter unit 13, the arm 41 extends outward from the top of the gear 39, and the crank pin 42 projects upward from the tip of the arm 41. The link mechanism 11 is connected.

  Further, as shown in FIG. 1 or FIG. 5, the arc portion 25 surrounding the outside of the gate 16 is formed wider than the outer circle 27 of the seal portion 21, and the true portion of the seal portion outer circle 27 is the bottom of the bottom portion. The inner circumferential side 43 corresponding to the upper side is cut and formed so as to float above the outer circle 27, the outer circumferential side 44 is made lower than just above the outer circle 27, and is formed at the same height as the seal portion 21. The outer peripheral edge portion 45 is cut again and formed higher than the seal portion 21. When the bottom plate 15 is viewed from below as shown in FIG. 5, except for the gate 16, the inner peripheral side 43 of the arc portion 25, the inner hole 35 of the upper receiving portion 33, the relay inlet 19, the relay outlet 20, and the outer peripheral edge 45. Are formed in the same plane, and the others are used as a contact surface 46 to the seal portion 21. Strictly speaking, the outer peripheral side 44 is not in contact with the seal portion 21 above the outer circle 27.

It is a longitudinal cross-sectional view which shows the rotary valve of this invention. It is a top view which shows the positional relationship of a rotary valve and a valve seat. It is a top view of a valve seat. It is a top view of a rotary valve. It is a bottom view of a rotary valve. It is sectional drawing which shows that the room in which gas goes in and out switches in order of (I) (B) (C) (D). It is explanatory drawing which shows that the relationship of the motion of a link mechanism and the rotational motion of a valve | bulb, and the rocking | fluctuation motion of a wing | blade changes in order of (a) (b) (c) (d). It is the front view which notched a part which shows the whole film | membrane type gas meter. It is the side view which notched a part which shows the whole film | membrane type gas meter. It is sectional drawing which shows the relationship between the conventional rotary valve and a valve seat. (A) is a plan view showing a conventional rotary valve, (b) is a bottom view, and (c) is a cross-sectional view taken along line AA.

Explanation of symbols

1 Meter body 2 Inlet 3 Rotary valve 4 Distributing chamber 9 Outlet 14 Valve seat 15 Bottom plate 16 Gate 17 Raised portion 18 Relay chamber 19 Relay inlet 20 Relay outlet 21 Sealing portion 22 Distributing port 23 Inlet port 25 Arc portion 43 Inner peripheral side 44 Outer peripheral side 46 Contact surface

Claims (1)

It consists of a circular bottom plate (15) and a raised portion (17) rising upward from the bottom plate. The bottom plate (15) is brought into contact with the concentric seal portion (21) of the valve seat (14) and the outer peripheral side of the bottom plate. Is formed with a fan-shaped gate (16) penetrating vertically, a ridge (17) is formed on the opposite side of the gate from the center of the bottom plate, and the interior of the ridge is opened downward (18), the portion corresponding to the opposite side of the gate in the relay chamber is the relay inlet (19), the portion corresponding to the center of the bottom plate in the relay chamber is the relay outlet (20),
The gas taken in from the inlet (2) of the meter body (1) flows into one of the four distribution ports (22) on the outer peripheral side of the seal portion through the gate (16), and from another distribution port (22). The exhausted gas is once taken into the relay chamber (18) through the relay inlet (19), discharged from the relay outlet (20) to the inlet (23) inside the seal portion, and finally the gas is supplied to the meter body. In the rotary valve of the membrane gas meter that is directed to the outlet (9) of
The arc part (25) surrounding the outer periphery of the gate (16) of the bottom plate (15) is formed by floating the inner peripheral side (43) corresponding to the position directly above the seal part from the seal part (21). In addition, the rotary valve of the membrane gas meter is characterized in that the outer peripheral side (44) is formed on the same plane continuous with the contact surface (46) to the seal portion.

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