JP4062677B2 - Gas flow meter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas flow meter provided with an electric on-off valve.
[0002]
[Prior art]
The conventional gas flow meter shown in FIG. 6 divides the inside of the case 1 into a flow path 2 and a component housing chamber 3 by a main partition wall 4, and further, a plurality of the interiors of the flow path 2 are divided by sub-compartment walls 7. The structure is divided into rooms. And the electric on-off valve 6 assembled in the valve mounting hole 5 of the main partition wall 4 is disposed opposite to the gas hole penetratingly formed in the sub-compartment wall 7, and when abnormal, the electric on-off valve 6 operates to close the gas hole, Shut off gas flow.
[0003]
Note that the present invention is an improvement of the product of the applicant of the present application, and no prior art document could be found.
[0004]
[Problems to be solved by the invention]
By the way, in the above-described conventional gas flow meter, the mounting flange 6F provided in the electric on-off valve 6 is screwed from the component housing chamber 3 side to the edge of the valve mounting hole 5. For this reason, screwing operation must be performed inside the component storage chamber 3, and the assembly work of the gas flow meter has been difficult.
[0005]
The present invention has been made in view of the above circumstances, and an object thereof is to provide a gas flow meter capable of easily assembling an electric on-off valve.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a gas flowmeter according to the invention of claim 1 includes a main partition wall that divides the interior of the case into a flow path and a component housing chamber, and the interior of the flow path into a plurality of rooms. A sub partition wall, wherein a valve mounting hole is formed in a portion of the main partition wall facing the sub partition wall, and an electric on-off valve is assembled to the valve mounting hole. A gas flow meter that has a gas hole penetrating through it at the opposite position and that always passes through the gas hole and flows inside the case. Is composed of a plurality of case components with a dividing surface between the main partition wall and the sub partition wall, and the mounting flange provided for the electric on-off valve is directed from the dividing surface side to the edge of the valve mounting hole. It is characterized by being screwed.
[0007]
According to a second aspect of the present invention, in the gas flowmeter according to the first aspect, the electrically operated on-off valve is formed by screwing a part of the valve body to the rotating shaft of the motor, and the valve body is directly moved by the rotation of the rotating shaft. It has the characteristic in the place comprised.
[0008]
The invention of claim 3 is characterized in that, in the gas flowmeter of claim 2, the motor is a stepping motor.
[0009]
[Action and effect of the invention]
<Invention of Claim 1>
In the gas flow meter according to the first aspect, when the case is disassembled into a plurality of case constituent bodies, the main partition wall is exposed at the dividing surface. In the exposed part, the mounting flange of the electric on-off valve can be screwed to the edge of the valve mounting hole, so that the mounting operation of the electric on-off valve can be performed more easily than the conventional one. it can.
[0010]
<Inventions of Claims 2 and 3>
In the gas flow meter according to claim 2, the valve body is moved directly by a screwed structure of the rotating shaft of the motor and a part of the valve body, so that the valve body is moved by a solenoid type direct drive source. The electric on-off valve can be reduced in size as compared with the case of direct movement. Specifically, the motor is preferably a stepping motor (invention of claim 3).
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, a case 10 provided in the gas flow meter of the present embodiment is configured by assembling a measurement unit 12 on the lower surface of a main body unit 11. The main body 11 has a rectangular parallelepiped shape that is flat in the front-rear direction, and the inside of the main body 11 is partitioned by a main partition wall 13 into a flow path 14 and a component housing chamber 15. Specifically, the main partition wall 13 is formed at a position spaced inward from the left and right side walls of the main body 11 and a position spaced upward from the lower surface of the main body 11. A space surrounded by the upper wall of the main body 11 is a component housing chamber 15. The front surface of the component storage chamber 15 is open, and the open portion is closed by a lid 16 attached to the front surface of the main body 11. A circuit board 17 is accommodated on the back surface of the lid 16. In addition, the space extending vertically on both sides of the component storage chamber 15 forms flow paths 14 and 14, and the flow paths 14 and 14 communicate with a pair of cylindrical portions 18 and 18 erected from both sides of the upper surface of the main body 11. is doing.
[0012]
As shown in FIG. 1, the measuring unit 12 has a configuration in which a flat flow tube 19 is assembled inside an outer casing 21 having an open upper surface, and an inner casing 20 having a lower opening is assembled from above.
[0013]
Details of the inner housing 20 are shown in FIG. The upper wall of the inner housing 20 constitutes a sub partition wall 24 according to the present invention, and the flow path 14 in the main body 11 has a measurement chamber 20B below the sub partition wall 24 and an upper gas guide chamber. It is divided into 20C. A step portion 20D (not shown in FIG. 1) is provided at an intermediate portion of the sub partition wall 24 in the left-right direction in FIG. The upper side of the step part 20 </ b> D is in close contact with the main partition wall 13 of the main body 11, while the lower stage side is opposed to the main partition wall 13 with a gap. Further, an exhaust gas hole 23 aligned with one cylindrical portion 18 is formed on the upper stage side of the sub partition wall 24, and an injection gas hole 28 is formed on the lower stage side at a position near the stepped portion 20D. ing. A gas pipe (not shown) is connected to both the cylindrical portions 18 and 18 of the main body portion 11, and as shown by the arrows in FIG. 28 flows into the measurement room 20B, passes through the flat flow tube 19, and is discharged from the discharge gas hole 23 to the outside of the measurement room 20B. The injection gas hole 28 has an edge protruding upward and a flat surface on the upper surface.
[0014]
The flat flow tube 19 extends from a position closer to one end in the longitudinal direction to a position closer to the other end in the measuring unit 12, and includes a flat space that is thinner in the vertical direction than the width dimension. In addition, a pair of ultrasonic sensors 22, 22 are provided inside the measuring unit 12 so as to face the open ports at both ends of the flat flow tube 19, and electric wires extending from the ultrasonic sensors 22 are connected to the circuit. It is connected to the substrate 17. The time until the ultrasonic wave transmitted from one ultrasonic sensor 22 is received by the other ultrasonic sensor 22 and the ultrasonic wave transmitted from the other ultrasonic sensor 22 are received by the one ultrasonic sensor 22. And the flow velocity / flow rate of the gas flowing in the flat flow tube 19 is detected based on the difference.
[0015]
Now, a valve mounting hole 25 is formed through a portion of the main body portion 11 facing the injection gas hole 28 in the main partition wall 13, and an electric on-off valve 30 is mounted here. As shown in FIG. 4, the valve mounting hole 25 has a round hole shape, and screw holes 27, 27 are formed at two positions on the main partition wall 13 with the valve mounting hole 25 interposed therebetween.
[0016]
The electric on-off valve 30 is shown in FIG. 5. For example, a male screw (not shown) is formed on the rotating shaft of the stepping motor 32, and a nut portion (not shown) provided on a part of the valve body 31. Is screwed onto the male screw. The valve body 31 and the motor main body 32A are connected to each other by a coil spring 33 so as not to rotate. Thereby, when the rotating shaft of the stepping motor 32 rotates, the valve body 31 moves directly in the axial direction of the rotating shaft. Further, a mounting flange 34 projects from the lower end portion of the motor main body 32A to the side, and the mounting flange 34 has two screw insertion holes 34A, 34A corresponding to the screw holes 27, 27 (FIG. 1). Reference) is formed. Furthermore, the connection terminal 35 (refer FIG. 5) has protruded from the side surface of the motor main body 32A toward the side.
[0017]
Next, the operation of the present embodiment configured as described above will be described.
In order to assemble the gas flow meter of this embodiment, as shown in FIG. 1, the main body part 11 and the measurement part 12 are divided. Thereby, the part which formed the valve attachment hole 25 among the main partition walls 13 is exposed. Here, for example, the main body 11 is turned upside down so that the dividing surface faces upward, and the packing 26 is laid on the opening edge of the valve mounting hole 25. The electric on-off valve 30 is tilted and inserted into the valve mounting hole 25 from the connection terminal 35, and the mounting flange 34 of the electric on-off valve 30 is directed to the opening edge of the valve mounting hole 25. In this state, the screw inserted through the screw insertion hole 34 </ b> A of the mounting flange 34 is tightened into the screw hole 27 formed in the main partition wall 13. Thereby, the electric on-off valve 30 is assembled to the main body 11.
[0018]
On the other hand, the ultrasonic sensor 22 is assembled to the measurement unit 12, the measurement unit 12 is assembled to the lower surface of the main body unit 11, and electric wires extending from electric parts such as the electric on-off valve 30 and the ultrasonic sensor 22 are connected to the circuit. Connect to substrate 17. Then, the assembly of the gas flow meter is completed by placing the circuit board 17 on the back side of the lid 16 and attaching the lid 16 to the main body 11.
[0019]
As described above, according to the gas flow meter of the present embodiment, when the case 10 is disassembled into the main body portion 11 and the measurement portion 12, the main partition wall 13 is exposed at the dividing surface. And since the mounting flange 34 of the electric on-off valve 30 can be addressed and screwed to the edge of the valve mounting hole 25 at the exposed portion, the mounting operation of the electric on-off valve 30 can be performed as compared with the conventional one. It can be done easily.
[0020]
<Other embodiments>
The present invention is not limited to the above-described embodiment. For example, the embodiments described below are also included in the technical scope of the present invention, and various other than the following can be made without departing from the scope of the invention. It can be changed and implemented.
(1) The electric on-off valve 30 of the above embodiment has a configuration in which the valve body 31 is directly moved by a screwed structure of the rotating shaft of the stepping motor 32 and the valve body 31, but the valve is a solenoid type direct acting actuator. You may move your body.
[0021]
(2) In the above embodiment, the ultrasonic gas flow meter is applied to the present invention. However, other than the ultrasonic flow meter may be used as long as it is a gas flow meter.
[Brief description of the drawings]
1 is an exploded perspective view of a gas flow meter according to an embodiment of the present invention. FIG. 2 is a side sectional view of the gas flow meter. FIG. 3 is a plan sectional view of the gas flow meter. Fig. 5 is a side view of the electric on-off valve. Fig. 6 is an exploded perspective view of a conventional gas flow meter.
10 ... Case 11 ... Main body (case structure)
12 ... Measuring unit (case structure)
DESCRIPTION OF SYMBOLS 13 ... Main partition wall 14 ... Flow path 15 ... Parts accommodation chamber 24 ... Sub opposing wall 25 ... Valve mounting hole 26 ... Packing 28 ... Injection gas hole 30 ... Electric on-off valve 31 ... Valve body 32 ... Stepping motor 34 ... For attachment Flange

Claims (3)

A main partition wall that divides the interior of the case into a flow path and a component storage chamber, and a sub partition wall that divides the interior of the flow path into a plurality of rooms,
A valve mounting hole is formed in a portion of the main partition wall that faces the sub partition wall, and an electric on-off valve is assembled to the valve mounting hole. Through the gas holes,
In a gas flow meter that always passes through the gas hole and gas flows through the case, and at the time of abnormality, the gas on-off valve closes the gas hole and shuts off the gas flow,
The case is formed by assembling a plurality of case components having a dividing surface between the main partition wall and the sub partition wall, and an attachment flange provided in the electric on-off valve is connected to the valve from the dividing surface side. A gas flowmeter characterized by being screwed to the edge of the mounting hole. 2. The electric on-off valve is configured such that a part of a valve body is screwed to a rotating shaft of a motor, and the valve body is directly moved by rotation of the rotating shaft. Gas flow meter. The gas flowmeter according to claim 2, wherein the motor is a stepping motor.

Images