JP2006308578A - Equalizing valve for measuring differential pressure, and differential pressure type flowmeter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an equalizing valve for measuring differential pressure and a differential pressure type flowmeter, capable of making size compact, of simplifying, and of reducing the cost. <P>SOLUTION: The first inlet passage 361 is extended along the axial direction of a valve stem 351, in the equalizing valve 35 assembled in the differential pressure type flowmeter, and a tapered part 351H provided around an axis of the valve stem 351 is advanced and retreated along the axial direction, to conduct switching from a differential pressure condition to an equalized condition. The equalizing valve 35 is made compact therein by the overlapped section where the advanced and retreated section for the valve stem 351 is overlapped with a valve passage 352. Pressure unevenness, caused by flow delays between the first lead-out passage 371 and the second lead-out passage 372, is reduced, since a distance between the first lead-out passage 371 and the second lead-out passage 372 is shortened by making compact. A valve element of the equalizing valve 35 is also easy to be assembled to contribute to reliability and cost reduction, because the valve element has simple structure, such as the tapered part 351H. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pressure equalizing valve for measuring a differential pressure and a differential pressure type flow meter for detecting a flow rate of a fluid to be detected.

Conventionally, differential pressure flow meters that measure the flow rate inside equipment piping have been used to optimize the operation and save energy of building air conditioning, cold / hot water equipment, factory exhaust systems, and dust collectors. ing.
Such a differential pressure type flow meter includes a differential pressure generating means disposed in a flow path through which the fluid to be detected passes. That is, when a stationary object is placed in the flow path through which the fluid to be detected passes, a differential pressure is generated before and after that. By applying this, a throttling mechanism such as an orifice that has a fixed flow rate relative to the generated differential pressure, The flow rate can be measured by generating a differential pressure by a differential pressure generating means such as a Pitot tube, a wake Pitot tube, or a laminar flow element.
A conventional differential pressure type flow meter includes a differential pressure generating means and a differential pressure sensor (for example, Patent Document 1 and Patent Document 2). In such a flow meter, an orifice is provided in the middle of the flow path, and the pressure of the fluid is taken out through the pressure guiding pipe before and after the orifice, and the taken out pressure is measured by a differential pressure sensor. In order to adjust the zero point, a pressure equalizing pipe connecting the pressure guiding pipes is provided, and a pressure equalizing valve is disposed in the pressure equalizing pipe. That is, the pressure equalizing valve is opened during zero point adjustment, the pressure of the fluid to be detected before and after the differential pressure generating means is equalized, and the differential pressure is measured after the zero point adjustment.

Here, in Patent Document 1, a fluid pressure resistor is provided in the pressure guiding tube, and the zero point adjustment can be performed by using only the resistor and the pressure equalizing valve without using a three-way valve or the like.
Further, Patent Document 2 proposes a pressure equalizing valve (shuttle valve) provided at a connection portion between the high pressure side path and the pressure equalizing communication path, and the pressure equalizing valve is interlocked so that the open / close states are opposite to each other. Each has a valve body on each end. The valve body portion of the pressure equalizing valve has an inclined surface formed on the valve body at the tip of the valve rod inserted into the valve box, and the valve box also has an inclined surface corresponding to the inclined surface. These inclined surfaces are brought into pressure contact with each other according to the advancement and retreat of the valve rod, thereby opening and closing the valve. The valve stem is advanced and retracted by a cylinder / piston having a spring.

On the other hand, since the differential pressure type flow meter as described above cannot detect the density change of the fluid to be detected due to the temperature or pressure change of the fluid to be detected, it can only measure the volumetric flow rate in the temperature and pressure conditions during flow rate measurement. As it is, it cannot be used as a mass flow meter.
That is, in order to measure the mass flow rate, it is necessary to measure the temperature, pressure, and flow rate of the fluid to be detected. Therefore, in addition to the differential pressure type flow meter as described above, a temperature sensor and these differential pressure type flow meters And a flow rate measuring system including a central device connected to a temperature sensor via a network has been proposed (Patent Document 3). In this flow measurement system, the temperature data measured by the temperature sensor is input to the differential pressure type flow meter via the central device, and the differential pressure type flow meter calculates the flow rate using the pressure data and the temperature data, and the flow rate data Is output to the central unit.

Japanese Patent Laid-Open No. 8-201206 (FIGS. 1, 2, and 3) JP-A-7-243930 (FIGS. 6 and 7) JP 2003-240616 A (Claim 1, FIG. 1)

  As described above, differential pressure type flow meters are widely used in building, factory, and plant processes, and have a simple structure, small size, and low cost so that they can be easily attached to these pipes. Things were desired. In addition, since the zero point adjustment using a pressure equalizing valve is usually indispensable for the differential pressure measurement, it is desired to be able to perform the zero point adjustment and the differential pressure measurement quickly and easily.

Here, in the flow meter of Patent Document 1, only a pressure equalizing valve is necessary, but a resistor is necessary as a premise thereof, and it is difficult to say that the structure is simplified. Since the structure is not simple, the cost may increase.
Further, in the configuration in which the high pressure side path is connected to the shuttle valve mechanism via the pressure equalizing communication path as in Patent Document 2, the high pressure side path connection port and the low pressure side path connection port at both ends of the communication path. Are arranged at positions separated from each other by the length of the communication path, so the differential pressure transmission path consisting of the high-pressure side path, the pressure equalization communication path, and the low-pressure side path is provided as a body (valve box). There is a limit to downsizing when mounted on. For this reason, it is difficult to reduce the size of the valve unit itself. In the first place, in the configuration of Patent Document 2, a valve body operating mechanism including a pneumatic cylinder device and a spring is provided outside the device body, which makes it more difficult to reduce the size of the device.

Furthermore, the flow rate measurement system of Patent Document 3 has a large and complicated structure in which a central device, a temperature sensor, and a differential pressure type flow meter are respectively arranged, and these devices and instruments must be separately constructed. Therefore, it takes time for instrumentation-related work including connection to the network, leading to high costs.
In such a differential pressure type flow meter, if the pressure equalizing valve or the flow meter itself is not sufficiently small, the distance between the pressure guiding pipes is large, so that the flow is delayed and it is difficult to equalize the pressure. is there.
On the other hand, in the configuration using the temperature sensor as in Patent Document 3, the temperature sensor is easily affected by the temperature of the flow rate detection unit to which the temperature sensor is attached, so that the reliability of the flow rate correction is impaired.

  In view of such problems, an object of the present invention is to provide a pressure equalizing valve for measuring a differential pressure that can be reduced in size, simplified in structure, and reduced in cost, and a differential pressure type flow rate provided with the pressure equalizing valve. To provide a total.

  The pressure equalizing valve for measuring the differential pressure according to the present invention is a valve box having a valve passage formed therein, and a rod-like member inserted from an insertion port provided on one end side of the valve passage in the valve box. And a valve rod having a valve body around an axis and partitioning the valve passage by the valve body in accordance with advancement and retreat in the axial direction, and the valve box communicates with the valve passage A first introduction path and a second introduction path into which the fluid pressure is introduced, respectively, and a first lead-out path and a second lead-out path through which the fluid pressure is discharged from the valve passage, respectively, are formed, and the first introduction path is formed. And the first lead-out path constitutes a first path, and the position in the axial direction of the valve stem of the one opening on the valve passage side and the other opening on the valve passage side is different from each other, 2 introduction path and the second lead-out path constitute a second path, and according to the advance and retreat of the valve stem, A differential pressure state in which the first path and the second path are partitioned to measure a differential pressure between the first path and the second path, and the first lead-out path is partitioned from the first introduction path. And is switched to a pressure equalization state in which the first lead-out path and the second lead-out path are pressure-equalized by communicating with the second path.

According to the present invention, the positions of the openings on the valve passage side of the first introduction path and the first lead-out path are shifted from each other, and the valve body provided around the shaft of the valve rod is only advanced and retracted along the axial direction. Thus, it is possible to easily switch from the differential pressure state to the pressure equalization state.
In the pressure equalization state, the first lead-out path on the first path side and the second lead-out path on the second path side communicate with each other, and the detected fluid is pressure-equalized in this communication space. This pressure equalization eliminates the pressure difference of the fluid to be detected in the first path and the second path, and with this, the zero point adjustment of the differential pressure measurement is performed, so that the differential pressure measurement can be appropriately performed.
That is, a valve body is inserted into one of the first introduction path and the first lead-out path to partition the first lead-in path and the first lead-out path, and in the communication space in the pressure equalization state, the detected side on the second path side on one side is detected. Since only the pressure of the fluid acts and the pressure on the first path side does not act, no fluid flows in the communication space (pressure equalization path). In this way, by shutting off one introduction path (here, the first introduction path) of the first path and the second path, fluid flows between the first introduction path and the second introduction path during pressure equalization. The pressure equalization path between the first introduction path and the second introduction path can be prevented from being throttled to generate a differential pressure.

  Here, since the section in which the valve stem advances and retreats overlaps the valve passage used for pressure equalization, the overlap, the valve passage or valve box, and the valve stem can be shortened. Miniaturization can be achieved. Thereby, it becomes possible to arrange | position the 1st derivation path and the 2nd derivation path close, and size reduction of a pressure equalization valve is promoted.

  Further, the pressure equalizing valve is closed by the valve body moving forward from the position between the first path and the second path to the first introduction path, or retreating to the insertion port side along the valve path. The structure may be simple, such as an annular member along the axis of the valve stem, or a tapered surface inclined in the axial direction along the axis. As a result, assembly is facilitated, so that reliability can be improved and cost reduction can be promoted.

  Note that either the first path or the second path can be the low pressure side (or the high pressure side).

  In the pressure equalizing valve of the present invention, the valve body is elastic and is a seal portion interposed between an outer peripheral surface of the valve stem and the valve box, and the seal portion is in the differential pressure state. And a first seal part that partitions the first path and the second path, and a second seal part that is disposed on the insertion port side and seals the pressure of the fluid in the valve passage. It is preferable.

  Here, the seal portion may be a part of the valve stem, or may be a separate member from the valve stem body. In the case of another member, an annular member such as a so-called O-ring can be used as the seal portion. Examples of the material for the seal portion include a rubber material that is resistant to the fluid to be detected, for example, a rubber material such as NBR (acrylonitrile butadiene rubber) or fluorine rubber.

According to the present invention, since the seal portion is in close contact with the inner peripheral surface of the valve passage due to the elasticity of the seal portion, the valve is surely opened and closed, and the differential pressure can be accurately measured.
The first seal portion is disposed between the first path and the second path in the differential pressure state, and is disposed in either the first introduction path or the valve path in the pressure equalization state. That is, the valve passage is partitioned by the first seal portion regardless of the differential pressure state or the pressure equalization state.

  In the pressure equalizing valve of the present invention, the seal portion includes a third seal portion provided at one end side in the extending direction of the valve passage with respect to the first seal portion, and the third seal portion is configured to be the pressure equalizing valve. It is preferable that the first introduction path is disposed in the pressure state.

  According to this invention, in the differential pressure state, the valve passage is partitioned by the first seal portion, while in the pressure equalization state, the valve passage is partitioned by the third seal portion. As a result, when the first seal portion is disposed between the first path and the second path at the time of measuring the differential pressure and moved to be inserted into the first introduction path from this position, the pressure is equalized. In comparison, the dimension (stroke) in which the valve stem advances and retracts can be shortened, and the valve stem operation can be simplified.

  In the pressure equalizing valve of the present invention, the valve passage extends from one end to the other end along the axial direction of the valve stem, and the first lead-out path is the first seal in the pressure-equalized state. It is preferable to extend along the radial direction of the valve passage, which is a direction intersecting the axial direction of the valve stem, between one of the first and third seal portions and the second lead-out path.

According to this invention, regarding the position where the first lead-out path is formed, between the first seal part and the second lead-out path, or when the third seal part is provided, the third seal part and the second A first lead-out path is formed along the radial direction of the valve passage at a position between the lead-out path. That is, by arranging the first lead-out path so as to intersect the valve passage in this way, the first lead-out path and the second lead-out path can be made sufficiently close to each other. Since the overlap margin between a part and the valve passage becomes large, the space efficiency required for the differential pressure transmission configuration including the first path and the second path is improved, and the entire configuration of the pressure equalizing valve can be further reduced in size. .
In addition, since the first lead-out path and the second lead-out path can be made sufficiently close in this way to shorten the distance between the first and second lead-out paths, the first lead-out path and the second lead-out path can be reduced during pressure equalization. Pressure unevenness due to a delay with the lead-out path can be reduced. That is, the pressure equalization state can be achieved quickly and appropriately.

  In the pressure equalizing valve of the present invention, the second introduction path and the second lead-out path are separated from each other at positions intersecting the valve path, and the second introduction path and the second lead-off path are in the pressure-equalized state. It is preferable that the lead-out path is partitioned.

  According to the present invention, since the second lead-out path is partitioned from the second introduction path, pulsation does not occur and the pressure is extremely stable, so that the pressure difference of the fluid to be detected is quickly and easily set to “0”. Can do.

In the pressure equalizing valve of the present invention, the seal portion includes a fourth seal portion provided between the second introduction path and the second lead-out path in the valve passage, and the fourth seal section It is preferable that the second introduction path and the second lead-out path are partitioned when the pressure is equalized.
According to this invention, the fourth seal portion can partition the second introduction path and the second lead-out path with a simple structure.

  In the pressure equalizing valve of the present invention, the valve box includes a cylindrical member into which the valve rod is inserted, and the cylindrical member includes the first lead-out path, the second lead-in path, and the second lead-out path. It is preferable that it is provided along the valve passage in the vicinity of at least one of the above.

According to the present invention, since the cylindrical member is provided, the valve is provided at the communication portion with the valve passage such as the first lead-out passage, the second lead-in passage, and the second lead-out passage formed so as to intersect the valve passage. The rod does not come into contact, and the trouble such as the valve rod being caught by the edge of the communicating portion (edge) and being damaged is prevented, and the valve rod can be smoothly advanced and retracted.
That is, when the first lead-out path, the second lead-in path, the second lead-out path, etc. are drilled in the valve box with a drill or the like, burrs or the like are likely to occur. It is effective to provide such a cylindrical member.

  In the pressure equalizing valve according to the aspect of the invention, the seal portion other than the second seal portion may include at least an opening end where the first lead-out path, the second lead-in path, and the second lead-out path communicate with the valve passage, respectively. It is preferable to arrange it with a gap.

According to this invention, since there is a gap between the inner wall surface of the communication portion of the communication portion and the first to third seal portions in the valve passage and does not contact each other, these seal portions are not caught on the edge of the communication portion, The valve stem can be smoothly advanced and retracted. Thereby, it is possible to effectively prevent the seal portion from being cut by a burr caused by perforating the first lead-out path, the second lead-in path, and the second lead-out path.
Even if the above-described tubular member is provided, the seal portion can be disposed with a gap from the inner wall surface of the communication portion of the valve passage.

In the pressure equalizing valve of the present invention, it is preferable that the valve stem has a knob protruding from the insertion port along the axial direction thereof.
According to the present invention, since the knob protrudes from the insertion port, an operation for moving the valve rod forward and backward by grasping the knob is easy, and it is possible to surely switch between the differential pressure state and the pressure equalization state.
Further, by forming scales or letters on the knob, it is possible to easily determine the size of the valve rod inserted into the valve passage. In addition, the insertion dimension of the valve stem into the valve passage can be determined by color-coded display instead of the scale, and these scale, character, and color-coded display may be used in combination.

  In the pressure equalizing valve of the present invention, the opening end of the insertion port is provided with a plate-like member having an insertion hole, and the knob has a reduced diameter at the axial end of the valve stem, It is preferable that the movement of the valve rod to the outside of the insertion port is restricted by being inserted through the insertion hole.

  According to the present invention, the diameter of the valve stem is enlarged on the base end side where the knob is formed, and when the valve stem is retracted toward the insertion port, the enlarged diameter portion comes into contact with the plate member and is inserted. Movement to the outside of the hole is restricted. Thereby, the detachment | leave from the valve case of a valve stem can be prevented.

  In the pressure equalizing valve of the present invention, it is preferable that an urging means for urging the valve rod along the axial direction is provided.

According to the present invention, the valve rod pushed into the valve passage against the urging force of the urging means or pulled out from the valve passage is returned to the original position by the urging force, so that the opening and closing operation of the valve is ensured. It can be carried out.
Further, by providing the urging means inside the valve passage in this way, it is unnecessary to provide a valve rod actuating device such as a cylinder / piston or solenoid for moving the valve rod outside the valve box. . For this reason, downsizing of the pressure equalizing valve is not hindered.
As the biasing means, a coil spring can be exemplified, and a valve rod can be inserted inside such a coil spring, or a coil spring can be incorporated inside the valve rod.

In the pressure equalizing valve according to the present invention, the knob has a substantially cylindrical cross section, and a fitting portion that fits the insertion hole is formed along an axial direction on an outer peripheral surface of the base end side. Is rotated around the axis in a state in which the fitting portion is disengaged from the insertion hole, and the fitting portion is preferably locked to the plate-like member by the urging force of the urging means. .
Here, the fitting portion of the knob is, for example, a convex rib formed on the outer peripheral surface of the valve stem, and this convex rib is fitted into a concave notch formed in the insertion hole of the plate member. It can be set as the structure to do. On the contrary, a concave groove or the like may be formed in the valve stem, and a convex protrusion formed in the insertion hole may be fitted into the groove.

  According to this invention, the valve rod is pushed into the valve passage against the urging force of the urging means or pulled out from the valve passage, and the valve rod is pivoted in a state where the valve rod and the insertion hole are not fitted. By rotating around, the fitting portion that is about to return to the original position by the urging force is brought into contact with and locked on the plate surface of the plate-like member. That is, with a simple structure such as a fitting portion, the position of the valve stem can be held at one of the differential pressure state or the pressure equalization state even when no external force is applied to the valve stem.

  A differential pressure type flow meter of the present invention includes a flow rate detection unit having a differential pressure generating means for generating a differential pressure in a fluid to be detected passing therethrough, and a differential pressure sensor that measures a differential pressure generated in the fluid to be detected by the flow rate detection unit. A sensor unit having a gauge pressure sensor for measuring the gauge pressure of the fluid to be detected, a temperature sensor for measuring the temperature of the fluid to be detected, and an absolute pressure sensor for measuring atmospheric pressure, and the sensor unit transmits the sensor pressure. A differential pressure type flow meter including a calculation means for calculating a flow rate of the fluid to be detected based on a signal and a display calculation unit having a display means for displaying the flow rate calculated by the calculation means. A pressure valve is provided.

According to the present invention, since the pressure equalizing valve described above is provided and the differential pressure sensor, the gauge pressure sensor, the temperature sensor, and the absolute pressure sensor for measuring atmospheric pressure are incorporated, the mass flow rate and the standard volume flow rate (0 ° C. Although it is a high-performance flowmeter that can measure at 1 atm or at 20 ° C. and 1 atm), as described above, miniaturization, simplification of structure, and cost reduction are promoted. The range of use of the flow meter can be further expanded.
Here, the differential pressure sensor, gauge pressure sensor, temperature sensor, and absolute pressure sensor for measuring atmospheric pressure can be installed to detect changes in the density of the detected fluid due to changes in the temperature and pressure of the detected fluid. The mass flow rate can be measured.
It is also possible to obtain a high resolution in a low flow rate region by connecting differential pressure sensors having different differential pressure ranges in parallel and selecting two or more appropriate differential pressure sensors according to the flow rate. At the same time, since the accuracy of the differential pressure sensor can be determined by each sensor, the flow rate range ability that can guarantee the flow rate accuracy can be widened.

In the differential pressure type flow meter of the present invention, the sensor unit and the display calculation unit are integrated and configured as a main body unit, and are joined to the flow rate detection unit, and the flow rate detection unit includes the differential pressure generating unit. And a flow path connection portion connected to the flow path of the fluid to be detected, and a main body attachment portion joined to the main body portion. The main body attachment portion has an upstream of the differential pressure generating means. Each extraction hole is formed in communication with the flow path on the side and on the downstream side to extract the pressure of the fluid to be detected into the sensor unit, and one of the extraction holes is connected to the main body of the flow rate detection unit. The temperature sensor extends linearly toward the flow path at a substantially central position of the joint surface, and the temperature sensor is formed in a rod shape and has a temperature-sensitive element on one end side, and is disposed at a substantially central position of the joint surface. One end side is inserted into the extraction hole, and the Temperature element faces the flow path, wherein the main body portion and the flow rate detection unit, it is preferable even when the temperature sensor is rotated together in the axial be joined.
The differential pressure generating means can be arbitrarily selected from a throttling mechanism such as an orifice, a pitot tube, a wake pitot tube, a laminar flow element, and the like.

According to this invention, a differential pressure sensor, a gauge pressure sensor, a temperature sensor, an absolute pressure sensor, a pressure equalizing valve, and the like are mounted on the main body, and no sensors are mounted on the flow rate detection unit. It is possible to mechanically separate the unit, simplify the structure, and easily perform the instrumentation-related work.
Further, since the temperature sensor is provided in the portion of the extraction hole using the pressure extraction hole of the fluid to be detected, it is not necessary to separately provide a temperature sensor attachment member and the like, and the structure can be further simplified.
In addition, it is preferable to provide the differential pressure sensor and the gauge pressure sensor by using the above-described extraction hole (shared with the extraction hole provided with the temperature sensor) in order to simplify the structure. When the pressure is introduced to the differential pressure sensor or gauge pressure sensor through the take-out hole provided with the temperature sensor, the diameter of the temperature sensor is taken from the diameter of the take-out hole so that the pressure is also transmitted to the differential pressure sensor and the gauge pressure sensor. Can also be reduced.

Further, by arranging the temperature sensor so that the position of the temperature sensing element is variable from the position facing the flow path to the position before the fluid passage portion in the differential pressure generating means, the temperature sensing element is Since it does not protrude toward the center of the flow path or obstruct the flow of the detected fluid, and the flow of the detected fluid in the flow path is not disturbed, the flow rate of the detected fluid can be accurately measured.
Here, regarding the arrangement of the temperature sensor, this temperature sensor is for measuring the temperature of the fluid, and is usually installed so that the temperature sensing element is located at the approximate center of the cross section with respect to the flow of the fluid. In the invention, since the temperature sensor is built in and the temperature sensor is arranged by utilizing the take-out hole of the body mounting portion, the temperature sensor and the differential pressure generating means are close to each other, and the temperature sensor is installed at substantially the center of the cross section of the flow of the channel If this happens, turbulence may occur. For this reason, it is very effective to provide the temperature sensing element at a position facing the flow path or a position slightly protruding from the take-out hole.

  In addition, since the take-out hole into which the temperature sensor is inserted is provided at substantially the center position of the joint surface of the main body mounting portion of the flow rate detection portion with the main body portion, the end of the main body portion is usually contacted with the fluid in the flow path. Since the main body and the flow rate detection unit can be rotated with the temperature sensor provided so as to protrude from the center as the central axis, the flow rate detection unit can be used regardless of the orientation in which the flow rate detection unit is attached to piping or the like. The main body attaching portion and the main body portion can be joined. In other words, the flow rate detector needs to be attached to the pipe in a direction that matches the flow direction determined by the type and specification of the differential pressure generating means, but the body part can be freely oriented, and the display direction of the display means can be changed. Since it can be made appropriate, the installation location of the flowmeter is not limited.

In addition, the shape of the joint surface between the flow rate detection unit and the main body unit is arbitrary. For example, the main body unit is made symmetrical with respect to the center point of the joint surface, such as a regular polygon or a circle, so that the main body unit is made to be a flow rate detection unit. The main body part overlaps the joint surface of the flow rate detection part even when rotated relative to the flow rate detection part, and the flow rate detection part and the main body part can be easily fixed at the outer peripheral part by means such as screwing.
Further, the main body portion may include an adapter or the like, and the main body portion may be joined to the flow rate detection portion by the adapter or the like.

In the differential pressure type flow meter of the present invention, it is preferable that a low thermal conductivity member having a low thermal conductivity is disposed between the temperature sensitive element and the inner peripheral surface of the extraction hole.
Here, as the low thermal conductivity member, a resin-based material such as Teflon (registered trademark) can be adopted.

According to this invention, the heat conduction between the temperature sensing element and the main body attachment portion is suppressed by the low thermal conductivity member being interposed between the temperature sensing element and the inner peripheral surface of the take-out hole. Therefore, it is difficult to be influenced by the temperature of the flow rate detection unit, and the temperature of the fluid to be detected can be accurately measured. In particular, a remarkable effect can be obtained when the flow rate detector is made of metal or the like and has a high thermal conductivity.
By using a jig or the like, it is possible to take out the temperature sensor and insert it into the hole with the low thermal conductivity member provided around the temperature sensitive element.

  In the differential pressure type flow meter of the present invention, an annular seal member that seals the fluid to be detected inside the take-out hole is provided on the inner circumference of the take-out hole, and the seal member is disposed on the inner circumferential surface thereof. It is preferable to have a plurality of protrusions and to hold and fix the temperature sensitive element between these protrusions.

According to the present invention, the sealing member is crushed by sandwiching the sealing member between the main body portion and the flow rate detection portion and tightening with a screw or the like, and the fluid to be detected is sealed in the extraction hole, so that the pressure leaks from the extraction hole. Can be prevented. In addition, since the temperature sensor is held between the protrusions formed on the seal member and does not come into contact with the inner peripheral surface of the take-out hole of the main body mounting portion, the influence of the temperature change of the flow rate detection portion on the temperature sensor is reduced. The temperature of the fluid can be measured accurately. Since the temperature sensor is held in a scattered manner between the plurality of formed protrusions, the take-out hole is not blocked.
Further, as the sealing member, like the above-described low thermal conductivity member, a seal member made of a material having low thermal conductivity is preferable.

  In the differential pressure type flow meter of the present invention, the flow rate detection unit is provided with the differential pressure generating means and connected to the flow path of the fluid to be detected, the upstream side of the differential pressure generating means, Each of the extraction holes is connected to the flow path on the downstream side and formed with respective extraction holes for extracting the pressure of the fluid to be detected to the sensor unit. The temperature sensor extends in a straight line toward the flow path, and the temperature sensor is formed in a rod shape and has a temperature sensing element on one end side, and one end side is inserted into one of the extraction holes extending in the straight line shape. A temperature element faces the flow path, and the one take-out hole is provided with a holding member that holds the temperature sensor along the longitudinal direction, and at least one of the outer peripheral surface and the inner peripheral surface of the holding member, It extends along the longitudinal direction of the temperature sensor. The through extraction hole and communicating, it is preferable that the communicating path capable of transmitting the pressure of the detected fluid is formed Te.

According to the present invention, in the configuration in which the fluid pressure extraction hole connecting the sensor unit and the flow path is formed in the pressure guiding unit of the flow rate detection unit, and the rod-shaped temperature sensor is inserted into the extraction hole, By providing the holding member that holds the sensor along the longitudinal direction, it is possible to prevent the temperature sensor from swinging obliquely with respect to the longitudinal direction. That is, even when the flow rate of the fluid in the flow rate detection unit is high or when the extraction hole has a long dimension that penetrates the main body mounting unit, the temperature sensor is held in a stable posture and the temperature sensing element at the tip of the temperature sensor flows. It can be maintained at a position facing the road or a position slightly protruding from this position to the flow path side. In addition, since the temperature sensor is held by the holding member in this way, it is possible to prevent the temperature sensor from being damaged due to vibration of the pipe and the like, and vibration resistance can be improved.
Even if such a holding member is provided in the take-out hole, since the communication path is formed in the holding member, the fluid pressure in the flow path can be taken out without any problem. The communication path can be constituted by, for example, a groove formed on the outer peripheral surface or the inner peripheral surface of the holding member, or can be constituted by a hollow portion formed in the thick portion of the holding member.

  In the differential pressure type flow meter of the present invention, the holding member is formed in a substantially cylindrical shape into which the temperature sensor is inserted, and has a slit along the axial direction of the holding member. The slit is preferably constituted by the slit.

  According to the present invention, the holding member has a substantially cylindrical shape having a slit, so that the temperature sensor can be held inside the cylindrical shape and the pressure of the fluid in the flow path can be transmitted along the slit. The configuration can be simplified. For example, the holding member can be easily formed by injection molding or the like, and the component cost can be suppressed. In addition, by forming the communication path by the slit, it becomes possible to provide both the temperature sensor and the holding member in the take-out hole without changing from the diameter size of the take-out hole when the holding member is not provided. Not disturbed.

  In the differential pressure type flow meter of the present invention, the holding member is a flange portion whose side surface is in contact with the inner peripheral surface of the extraction hole, and a portion other than the flange portion, and has an outer diameter that is larger than the inner diameter of the extraction hole. It is preferable to have a small-diameter portion.

  According to the present invention, by providing the small-diameter portion that does not contact the inner peripheral surface of the take-out hole, it is possible to reduce the temperature effect due to the heat transmitted from the main body attachment portion to the temperature sensor via the holding member. The flange portion can be formed at an arbitrary position in the axial direction of the holding member, but the flange portion is respectively provided at both ends in the axial direction rather than being formed at one substantially central portion in the axial direction of the holding member. When the portion is formed, the holding member is stably held on the inner peripheral surface of the take-out hole, and the holding of the temperature sensor by the holding member is also stabilized.

  In the differential pressure type flow meter of the present invention, it is preferable that the holding member is formed of a low thermal conductivity material having a low thermal conductivity.

According to the present invention, even if the main body mounting portion is made of a material having a high thermal conductivity such as a metal, the temperature influence from the main body mounting portion to the temperature sensor can be reduced as much as possible, so that high accuracy can be realized in flow rate measurement.
Examples of the low thermal conductivity material include resin-based materials such as PTFE (polytetrafluoroethylene) and POM (polyoxymethylene).

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
In the description of the second and subsequent embodiments, the same components as those of the first embodiment described below are denoted by the same reference numerals, and description thereof is omitted or simplified.
FIG. 1 is a perspective view of a flow meter 1 in the present embodiment, and FIG. 2 is a side sectional view of the flow meter 1. In FIG. 2, the case 43 is removed.
The flow meter 1 is a differential pressure type that is attached to the pipe 100 (FIG. 2) and measures the flow rate of the fluid FL inside the pipe 100 using the differential pressure generated in the fluid FL that has passed through the differential pressure generating means. .
This flow meter 1 includes a flow rate detection unit 10 attached to a pipe 100, a main body unit 30 having an adapter 20 that is provided with a sensor unit 31 and joined to the flow rate detection unit 10, and a signal transmitted from the sensor unit 31. And a display calculation unit 40 (FIG. 1) for calculating and displaying the flow rate. The display calculation unit 40 is incorporated in the case 43.

FIG. 3 is a side sectional view of the flow rate detector 10.
The flow rate detection unit 10 is made of metal such as SUS, and includes a pipe member 11 having a female screw portion 111 at both ends as a flow path connection unit for connection to the pipe 100, and the inside of the pipe has a flow of the fluid FL. A path 13 is formed. Further, a SUS orifice 14 as a differential pressure generating means is provided at the approximate center of the flow path 13 in the pipe member 11 so as to face the flow of the fluid FL. Further, a plate-like portion 12 as a main body attachment portion is welded to the side surface of the pipe member 11.

The orifice 14 is a disk-like member having a circular hole 141 formed in the substantially center, and the fluid FL passes through the flow hole 141 along the direction of arrow A in FIG. The flow is narrowed. Thereby, the pressure of the fluid FL on the downstream side of the orifice 14 becomes lower than that on the upstream side of the orifice 14. In the present embodiment, the cross-sectional shape of the hole 141 of the orifice 14 is such that the diameter on the downstream side is increased, but is not limited thereto.
In addition, upstream and downstream of the orifice 14 are communicated with the flow path 13 so that an upstream extraction hole 131 and a downstream extraction hole 132 for extracting the pressure of the fluid FL penetrate the plate-like portion 12 respectively. Is formed.

As shown in FIG. 4, the plate-like portion 12 has a square shape in a plan view, a pressure extraction portion 15 having a circular shape in a plan view is formed at a substantially center, and screws for attaching the main body portion 30 at four corners. Each hole 121 is formed.
A concave portion 154 that is recessed in a circular shape in plan view is formed inside the peripheral edge portion 153 in the pressure extraction portion 15. An extraction portion 151 through which the extraction hole 131 passes is disposed in the center of the recess 154, and the remaining portion of the recess 154 is an extraction portion 152 through which the extraction hole 132 passes. These extraction parts 151 and 152 are arranged on concentric circles.
The take-out part 151 is formed in a cylindrical shape surrounding the take-out hole 131.
On the other hand, an extraction hole 132 passes through the bottom 154A of the recess 154 in the extraction portion 152.

FIG. 5 is a side sectional view of the main body 30 and the adapter 20 fixed to each other, and FIGS. 6 and 7 are views showing a state in which the main body 30 is attached to the flow rate detection unit 10 by the adapter 20. FIG. 8 is a view showing the back surface 32 </ b> B (joint surface with the adapter 20) of the main body 30.
The adapter 20 is a plate-like member for attaching the main body 30 to the flow rate detection unit 10, and has one surface joined to the flow rate detection unit 10, the flow rate detection side joint 21 having a substantially square shape in plan view, and the other. The surface is a main body side joint portion 22 having a substantially rectangular shape in plan view and joined to the back surface 32 </ b> B of the main body portion 30.
Further, an extraction hole 201 communicating with the extraction hole 131 of the flow rate detection unit 10 is formed so as to pass through substantially the center of the adapter 20 in the plane, and the extraction of the flow rate detection unit 10 is at a position slightly away from the extraction hole 201. An extraction hole 202 communicating with the hole 132 is formed.

As shown in FIGS. 6 and 7, in the flow rate detection side joining portion 21, the pair of sides are exposed from the main body 30 having a rectangular shape in plan view, and through holes 211 are formed at the four corners, respectively. . These through-holes 211 overlap the screw holes 121 of the plate-like portion 12, and the flow rate detection side joining portion 21 and the plate-like portion 12 are screwed into the screw holes 121 via the through-holes 211. , Fixed to each other.
In addition, annular grooves 214A and 215A in which large and small diameter rubber O-rings 214 and 215 are respectively disposed are formed on the joint surface 213 (FIG. 5) of the flow rate detection side joint 21 to the plate-like portion 12. These O-rings 214 and 215 are crushed in a state where they are in contact with the peripheral portion 153 (FIG. 2) and the end 151A (FIG. 2) of the take-out portion 151 when the screw 212 (FIG. 6) is tightened. Thus, each extraction hole 201, 202 is sealed as a pressure guiding path for the fluid FL.

  Here, the flow detection side joint 21 and the plate-like part 12 of the flow rate detection unit 10 are both square in plan view, so that the flow rate detection side joint 21 is attached to the flow rate detection unit 10. As shown in FIG. 6 and FIG.

On the other hand, through holes (not shown) are formed at the four corners of the main body side joining portion 22 at positions overlapping with the screw holes 324 (FIG. 8) formed at the four corners of the back surface 32B of the main body portion 30, respectively. By screwing a screw 222 (FIG. 5) into the screw hole 324, the main body side joining portion 22 and the main body portion 30 are fixed to each other.
In addition, on the joint surface 223 of the main body side joint portion 22 to the main body portion 30, annular grooves in which rubber O-rings 224 and 225 are respectively disposed are formed around the take-out holes 201 and 202. When the screws 224 and 225 are crushed when the screw 222 is tightened, the extraction holes 201 and 202 are sealed as pressure guiding paths.

Next, as shown in FIGS. 5 and 8, the main body 30 includes a substantially rectangular plate-like base 32 on which the sensor unit 31 is mounted, and is attached to the base 32 so as to cover the sensor unit 31. 40 and a case 43 (FIG. 1) in which a battery (not shown) is incorporated.
The sensor unit 31 includes a differential pressure sensor 311 that measures the differential pressure generated in the fluid FL by the flow rate detection unit 10, a gauge pressure sensor 312 that measures the gauge pressure of the fluid FL, and a temperature sensor 313 that measures the temperature of the fluid FL. And an absolute pressure sensor 314 (FIG. 9) for measuring atmospheric pressure.

Further, as shown in the rear view of FIG. 8, the base 32 has an extraction hole 321 communicating with the extraction hole 201 of the adapter 20 at substantially the center, and the extraction hole 202 at a position slightly away from the extraction hole 321. An extraction hole 322 communicating with each other is formed through.
Here, the take-out hole 321 and the take-out hole 322 communicate with each other by a passage 323 formed inside the base 32, and a pressure equalizing valve 35 having the base 32 as a valve box is provided in the passage 323. .

The passage 323 extends from the end surface of the base 32 along the planar direction of the base 32, and one end side is an insertion port 323A into which the valve rod 351 of the pressure equalizing valve 35 is inserted, and the vicinity of the insertion port 323A is an enlarged diameter portion. It is 323B. In addition, a sensor disposition hole 323D in which the gauge pressure sensor 312 is disposed is formed on the other end side of the passage 323.
The take-out hole 321 is enlarged in diameter on the surface 32A side of the base 32, and a screw for fixing the temperature sensor 313 is engraved on the inner peripheral surface of the enlarged diameter portion 321A.

Here, the pressure guiding path of the fluid FL related to the pressure equalizing valve 35 will be described. First, in the passage 323, the extraction hole 131 and the extraction hole are arranged upstream from the extraction hole 321 to the end of the valve rod 351. 201 and a first introduction passage 361 for introducing the pressure of the fluid FL taken out through the extraction hole 321 into the valve passage 352. That is, the first introduction path 361 extends along the axial direction of the valve rod 351.
The passage 323 branches between the position where the extraction hole 321 intersects the passage 323 and the position where the extraction hole 322 intersects the passage 323 and penetrates to the surface 32A side of the base 32. This is a first outlet path 371 for leading the pressure of the fluid FL taken out through the first inlet path 361 to the differential pressure sensor 311.
The passage 323 is formed with an inclined surface that gradually decreases in diameter from the second lead-out path 372 side toward the first lead-out path 371 side at a position between the first lead-out path 371 and the second lead-out path 372. This portion is a reduced diameter portion 323C.

The take-out hole 322 extends so as to intersect the passage 323 in the thickness direction of the base 32, and the second introduction passage for introducing the pressure of the fluid FL into the valve passage 352 from the back surface 32 </ b> B side of the base 32 to the passage 323. 362 and the base 32 surface 32A side from the passage 323 is a second lead-out path 372 for leading the fluid FL taken out through the second introduction path 362 to the differential pressure sensor 311.
The pressure equalizing valve 35 equalizes the pressure of the fluid FL that is led to the differential pressure sensor 311 through the first lead-out path 371 and the fluid FL that is led to the differential pressure sensor 311 through the second lead-out path 372. It is provided to compress.

FIG. 9 is a conceptual diagram of the sensor unit 31 and the flow rate detection unit 10, and the configuration of the sensor unit 31 will be described with reference to FIG. 9 and FIG.
The differential pressure sensor 311 is provided so as to seal each opening of the first and second lead-out paths 371 and 372 of the surface 32A of the base 32, and measures the differential pressure generated in the fluid FL by the flow rate detection unit 10. That is, there are pressure guiding spaces for extracting the pressure of the fluid FL from the upstream side of the flow rate detection unit 10 through the extraction holes 131, 201, 321, or from the upstream side of the flow rate detection unit 10 through the extraction holes 132, 202, 322, respectively. It is configured.

  The gauge pressure sensor 312 protrudes from the element portion 312A inserted into the sensor placement hole 323D and the surface 32A of the base 32, and measures the gauge pressure of the fluid FL. The measured gauge pressure is added to the atmospheric pressure measured by the absolute pressure sensor 314 in addition to being displayed on the display calculation unit 40, and is used for calculating the mass flow rate and the standard volume flow rate as the absolute pressure of the fluid FL.

  As shown in FIG. 5, the temperature sensor 313 is provided on a rod-like main body 313A inserted into the take-out hole 321, a cylindrical screw member 313B fixed around the main body 313A, and one end of the main body 313A. A thermosensitive element 313G that penetrates the base 32 and the adapter 20 and protrudes to the outside is provided, and the other end side of the main body 313A is connected to the display calculation unit 40 by wiring 313D.

FIG. 10 is an enlarged view of FIG. 5 and shows the attachment of the temperature sensor 313 to the take-out hole 321.
As shown in FIG. 10, the main body 313A is inserted into the extraction hole 321 with a clearance SP1 between the main body 313A and the inner peripheral surface of the extraction hole 321, and the screw 313F carved on the outer periphery of the screw member 313B is inserted into the extraction hole. The screw member 313B is screwed into the enlarged diameter portion 321A, and the end surface of the screw member 313B is pressed against the proximal end portion 321B of the enlarged diameter portion 321A, thereby being fixed to the take-out hole 321.

Here, a Teflon (registered trademark) low thermal conductivity member and an annular packing 313E as a seal member are provided at a position where the main body 313A is inserted into the enlarged diameter portion 321A, and a screw member 313B is screwed. At this time, the packing 313E is crushed between the screw member 313B and the base end 321B, and the space between the main body 313A and the take-out hole 321 is sealed.
Further, the packing 313E is crushed, and the main body 313A is held by the packing 313E without being in contact with the inner peripheral surface of the take-out hole 321.

  FIG. 11 is a cross-sectional view of the temperature sensor 313 taken along line XI-XI in FIG. As shown in FIG. 11, the aforementioned O-ring 224 has three protrusions 224C that protrude from the inner peripheral surface 224B toward the inside at substantially equal intervals. The temperature sensor 313 is held in a state in which the temperature sensor 313 is not in contact with the inner peripheral surface of the take-out hole 321 of the base 32 by the tip portions of the protrusions 224C. Since the temperature sensor 313 is held in a scattered manner by the protrusions 224C, the take-out hole 321 is not blocked, and the fluid FL can be guided inside the take-out hole 321.

  Further, the temperature sensing element 313G is inserted into the take-out hole 131 of the flow rate detection unit 10 when the main body 30, the adapter 20, and the flow rate detection unit 10 are assembled. Here, as shown in FIG. 2, the tip 313H of the temperature sensing element 313G does not protrude to the approximate center of the cross section of the flow path 13 in the pipe 100, and flows from a position facing the flow path 13 at the opening of the extraction hole 131. It is provided so as to slightly protrude toward the path 13 side.

As shown in FIG. 1, the case 43 is an aluminum member formed in a rectangular box shape in plan view, and includes a display calculation unit 40 and a battery storage unit (not shown).
On the front side of the case 43, a liquid crystal panel unit 431 as a display means in the display calculation unit 40 in which the flow rate of the measured fluid FL, monitor information such as operation mode, battery voltage drop, alarm output, etc. is displayed; An operation panel unit 432 for performing mode switching and various settings is provided.
In the case 43, a circuit block on which a liquid crystal panel unit 431, an operation panel unit 432, a drive circuit (not shown) of the sensor unit 31, an arithmetic unit 41 (FIG. 9), and the like are mounted is provided. Is stored in a battery storage (not shown). When the power source is not a battery, a terminal for connecting the power source is provided instead of the battery housing portion.

Next, the pressure equalizing valve 35 will be described.
FIG. 12 is a side view of the pressure equalizing valve 35.
The valve rod 351 of the pressure equalizing valve 35 is a tapered portion 351H as a valve body having a tapered shape at one end side, and a communication portion where the first introduction path 361 and the first lead-out path 371 communicate with each other from the insertion port 323A. Up to 352D is defined as a valve passage 352, and the valve rod 351 advances and retreats along the valve passage 352 as shown in FIGS. As a result, the valve passage 352 is partitioned in the tapered portion 351H, so that the pressure equalizing valve 35 functions as an on-off valve that blocks or permits the flow of the guided pressure of the fluid FL.

The valve stem 351 is a member having a substantially cylindrical cross section, a valve stem main body 351A having a tapered portion 351H, and a threaded portion formed on the insertion port 323A side of the valve stem main body 351A and screwed on the outer periphery. When the valve stem 351 is retracted in the vicinity of the insertion port 323A of the enlarged diameter portion 351C and the enlarged diameter portion 351C, the enlarged diameter portion 351C formed in the valve passage 352 in accordance with the diameter of the enlarged diameter portion 323B (FIG. (B)) It has a knob 353 protruding from the insertion port 323A.
When the valve stem 351 moves forward (FIG. 12A), the tapered portion 351H comes into contact with the reduced diameter portion 323C on the valve passage 352 side, thereby cutting off the pressure of the fluid FL.

  The valve stem body 351 </ b> A has a diameter smaller than the diameter of the valve passage 352, and a gap SP is opened between the outer peripheral surface thereof and the inner peripheral surface of the valve passage 352. That is, as shown in FIG. 12A, even if the valve stem body 351A crosses the extending direction of the second introduction path 362 and the second lead-out path 372, the second introduction path 362 and the second lead-out path 372 Pressure can be introduced between the two.

The screw portion 351B is formed between the valve stem main body 351A and the enlarged diameter portion 351C, and is screwed into a screw 352A engraved on the inner peripheral surface of the valve passage 352 so that the valve stem 351 advances and retreats. It has become.
A groove portion 351E having a diameter reduced in the radial direction is formed in the enlarged diameter portion 351C, and a second seal portion 382 that is a ring-shaped rubber is disposed around the groove portion 351E. The second seal portion 382 seals the pressure guiding space in the passage 323 (FIG. 5).

  A groove 353A is formed in the head of the knob 353, and a screw portion 351B can be screwed into the valve passage 352 by inserting a screwdriver into the groove 353A and rotating the knob 353. .

  Here, when the knob 353 is turned to advance the valve rod 351 into the valve passage 352, the tapered portion 351H comes into contact with the reduced diameter portion 323C as shown in FIG. At this time, if the first introduction path 361 and the first lead-out path 371 are the first path P1, and the second introduction path 362 and the second lead-out path 372 are the second path P2, these first and second paths P1 and P2 Are partitioned from each other by the taper portion 351H, the pressure of the fluid FL is cut off, and the pressure equalizing valve 35 is closed. This is a differential pressure state in which the differential pressure of the first path P1 and the second path P2 can be measured in the differential pressure sensor 311.

  In such differential pressure measurement, when performing zero point adjustment, the knob 353 is rotated in the opposite direction to retract the valve rod 351. Accordingly, as shown in FIG. 12B, the tapered portion 351H is separated from the reduced diameter portion 323C, the first path P1 and the second path P2 are communicated with each other, and the pressure equalizing valve 35 is opened. This state becomes a pressure equalization state in which the zero point of the differential pressure sensor 311 can be adjusted by equalizing the pressure of the fluid FL in the first path P1 and the second path P2. That is, when the knob 353 of the pressure equalizing valve 35 is rotated to gradually retract the valve rod 351 from the valve passage 352, the first path P1 and the second path P2 communicate with each other, and the pressure is gradually equalized.

When the differential pressure type flow meter 1 described above is used, the zero point adjustment for the differential pressure measurement in the differential pressure sensor 311 is performed as described above.
After the zero point adjustment, when the knob 353 of the pressure equalizing valve 35 is returned to the original position, the first path P1 and the second path P2 are separated from each other, and the differential pressure type flow meter 1 can be used.

  Then, in the flow path 13 in the pipe 100, the differential pressure generated in the fluid FL before and after the passage of the orifice 14 is measured by the differential pressure sensor 311. As shown in FIG. Sent to. Further, the gauge pressure sensor 312 measures the pressure upstream of the orifice 14 measured under atmospheric pressure conditions, and transmits the measured value to the display calculation unit 40. Similarly, the temperature sensor 313 measures the temperature of the fluid FL on the upstream side of the orifice 14, and the absolute pressure sensor 314 measures the atmospheric pressure, and these measured values are transmitted to the display calculation unit 40.

  Next, in the display calculation unit 40, based on the signal transmitted from the sensor unit 31, that is, based on the relationship between the differential pressure of the fluid FL, the gauge pressure, the temperature, the atmospheric pressure, and the flow rate with respect to the generated differential pressure of the orifice 14. The flow rate of the FL is calculated, and the flow rate is displayed on the liquid crystal panel unit 431 in the form of a digital numerical value display or a bar display. When the flow rate exceeds a predetermined value, an alarm is output according to the mode.

According to such 1st Embodiment, there exist the following effects.
(1) According to the pressure equalizing valve 35 incorporated in the differential pressure measurement type flow meter 1, the first introduction path 361 extends along the axial direction of the valve stem 351 and is provided around the axis of the valve stem 351. The taper portion 351H can be easily switched from the differential pressure state to the pressure equalization state simply by advancing and retreating along the axial direction.
In the pressure equalization state, the first lead-out path 371 on the first path P1 side and the second lead-out path 372 on the second path P2 side communicate with each other, and the fluid FL is pressure-equalized in this communication space. This pressure equalization eliminates the pressure difference of the fluid FL in the first path P1 and the second path P2, and the zero point adjustment of the differential pressure measurement is performed with this, so that the differential pressure measurement can be appropriately performed.

  Here, since the section in which the valve stem 351 advances and retreats overlaps with the valve passage 352 used for pressure equalization, the overlap, the valve passage 352 or the base 32, and the valve stem 351 can be shortened. The pressure equalizing valve 35 can be downsized. Due to this downsizing, the distance between the first lead-out path 371 and the second lead-out path 372 is shortened, so that the pressure unevenness due to the delay between the first lead-out path 371 and the second lead-out path 372 can be reduced, It is possible to quickly and appropriately equalize the pressure of the fluid FL in the first lead-out path 371 and the second lead-out path 372.

  Further, the pressure equalizing valve 35 is opened by the taper portion 351H retreating from the position between the first path P1 and the second path P2 along the valve passage 352 toward the insertion port 323A. A simple structure such as a tapered portion 351H can be obtained. As a result, the flow meter 1 can be easily assembled, so that reliability can be improved and cost reduction can be promoted.

(2) Since the knob 353 protrudes from the insertion port 323A and the groove 353A is formed in the knob 353, the valve rod 351 can be easily screwed back and forth with respect to the valve passage 352, and the differential pressure state and the pressure equalization It is possible to switch to the state reliably.

(3) Since the gap SP is opened between the valve stem main body 351A and the valve passage 352, when the valve stem 351 advances and retreats with respect to the valve passage 352, the second introduction passage 362 and the valve passage 352 The valve stem body 351A does not contact the open ends (edges) 362B and 372B through which the second lead-out path 372 passes. As a result, it is possible to prevent problems such as the valve rod 351 moving back and forth smoothly due to contact with the open end 372B.
In addition, the valve stem body 351A can be effectively prevented from being damaged by burrs or the like due to drilling when forming the first lead-out path 371, the second lead-in path 362, and the second lead-out path 372.
The valve stem 351 of the present embodiment has a threaded portion 351B, and advances and retracts by screwing with the screw 352A on the inner peripheral surface of the valve passage 352. The valve rod 351 can be advanced and retracted while maintaining a clearance SP between 351A and the inner peripheral surface of the valve passage 352.

(4) Since the differential pressure type flow meter 1 includes the pressure equalizing valve 35 and further includes the differential pressure sensor 311, the gauge pressure sensor 312, the temperature sensor 313, and the absolute pressure sensor 314, it has a high function capable of measuring a mass flow rate. Although the flow meter 1 is used, as described above, downsizing, simplification of the structure, and cost reduction are promoted, and the usage range of the flow meter 1 can be further expanded.
Here, the differential pressure sensor 311, the gauge pressure sensor 312, the temperature sensor 313, and the absolute pressure sensor 314 for measuring atmospheric pressure are installed, so that changes in the density of the fluid FL due to changes in the temperature and pressure of the fluid FL are detected. The mass flow rate can be measured.

(5) In the differential pressure type flow meter 1, the sensor unit 31 and the display calculation unit 40 are integrated as the main body unit 30, and no sensors are mounted on the flow rate detection unit 10. And the sensor unit 31 can be mechanically separated, the structure can be simplified, and the construction work related to instrumentation can be easily performed.
Further, since the temperature sensor 313 is provided inside the pressure extraction holes 321, 201, 131 of the fluid FL, it is not necessary to separately provide a mounting member for the temperature sensor 313, and the structure can be further simplified.

(6) Furthermore, since the temperature sensor 313 is disposed so that the temperature sensitive element 313G slightly protrudes from the position facing the flow path 13 toward the flow path 13, the temperature sensitive element 313G is directed toward the center of the flow path 13. The flow of the fluid FL is not disturbed, and the flow of the fluid FL is not disturbed. Therefore, the flow rate of the fluid FL can be accurately measured.
Here, regarding the arrangement of the temperature sensor 313, the temperature sensor 313 is for measuring the temperature of the fluid FL, and is usually installed so that the temperature-sensitive element 313G is located at the approximate center of the cross section with respect to the flow of the fluid FL. However, in the present embodiment, the temperature sensor 313 is built in the main body 30 and the temperature sensor 313 is arranged using the take-out holes 321, 201, 131 of the flow rate detection unit 10, so the temperature sensor 313 and the orifice 14 are arranged. When the temperature sensor 313 is installed at the approximate center of the cross section of the flow path 13, turbulence may occur. For this reason, it is very effective to provide the temperature sensitive element 313G at a position facing the flow path 13 or a position slightly protruding toward the flow path 13 in this way.

(7) In addition, since the take-out holes 321, 201, 131 into which the temperature sensor 313 is inserted are provided at substantially the center position of the joint surface with the main body 30 of the flow rate detection unit 10, normally, The main body 30 and the flow rate detection unit 10 can be rotated with respect to each other about a temperature sensor 313 provided so as to protrude from the end of the main body 30 so as to contact the fluid FL. Accordingly, the main body 30 can be joined to the flow rate detection unit 10 regardless of the direction in which the flow rate detection unit 10 is attached to the pipe 100. That is, the flow rate detection unit 10 must be attached to the pipe 100 or the like in a direction that matches the flow direction determined by the type and specification of the differential pressure generating means such as the orifice 14, but the body unit 30 can be freely oriented. Since the display direction of the liquid crystal panel unit 431 can be made appropriate, the installation location of the flow meter 1 is not limited.

(8) The plate-like portion 12 of the flow rate detection unit 10 and the flow rate detection-side joining portion 21 of the adapter 20 joined to the plate-like portion 12 are both square in plan view, and the flow rate detection unit 10 and the adapter The screw holes formed at the four corners of these plate-like parts 12 even if the main body part 30 is rotated by 90 ° with respect to the flow rate detection part 10 because it has a symmetric shape with respect to the center point of the joint surface with 20. 121 and the positions of the through holes 211 formed at the four corners of the flow rate detection side joint 21 are not displaced, and can be securely fixed with screws.

(9) Heat conduction between the temperature sensing element 313G and the base 32 is achieved by placing a Teflon (registered trademark) packing 313E between the temperature sensing element 313G and the inner peripheral surface of the extraction hole 321. Therefore, compared to the case where the temperature sensor 313 is provided only with the metal screw member 313B, the temperature of the fluid FL can be accurately measured as it is less affected by the temperature of the base 32.

(10) Since the temperature sensor 313 is held between the protrusion 224C and the protrusion 224C formed on the O-ring 224 and does not contact the inner peripheral surface of the take-out hole 201 of the adapter 20, the temperature change of the adapter 20 The influence on the sensor 313 can be reduced, and the temperature of the fluid FL can be accurately measured.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, the structure of the valve body and the valve stem in the pressure equalizing valve 55 is different from that in the above embodiment.
FIG. 13 is a side sectional view of the pressure equalizing valve 55 in the present embodiment. In addition, the cross-sectional display (hatch line) in the valve stem 551 is omitted for convenience of drawing.

  First, the valve passage 552 of the pressure equalizing valve 55 is a space in which the diameter is increased from the intermediate portion 361A of the first introduction passage 361 to the insertion port 323A in the passage 323 (FIG. 5) formed in the base 32. In this valve passage 552, a step between the first lead-out path 371 and the second lead-in / lead-out path 362, 372 is reduced in diameter from the second lead-out / lead-out path 362, 372 side to the first lead-out path 371 side. A portion 552A is formed.

The valve rod 551 in the pressure equalizing valve 55 includes a valve rod body 551A having a substantially cylindrical cross section, a seal holding portion 551B that holds a first seal portion 581 as a valve body on one end side of the valve rod body 551A, and a valve rod body. A seal holding portion 551C for holding the second seal portion 382 on the other end side of 551A and a knob 553 are configured.
The valve rod 551 advances and retreats along the valve passage 552 as shown in FIGS. 14A and 14B, and the valve passage 552 is partitioned by the first seal portion 581, so that the pressure equalizing valve 55 is guided to the fluid FL. It functions as an on-off valve that shuts off or permits.
Here, the first lead-out path 371 is provided at a position between the first seal portion 581 and the second lead-out path 372 in the pressure equalized state shown in FIG. 14B, and extends along the radial direction of the valve passage 552. It extends. By arranging the first lead-out path 371 and the second lead-out path 372 with respect to the valve passage 552, the first lead-out path 371 and the second lead-out path 372 are disposed sufficiently close to each other in the fairly small pressure equalizing valve 55. Can be realized. Thereby, while being able to contribute to size reduction of the pressure equalizing valve 55, the pressure nonuniformity by delay can be made small, Therefore A pressure equalization can be performed rapidly and appropriately.

  The valve stem main body 551A has a narrower shaft than the seal holding portions 551B and 551C, and a compression coil spring 554 as an urging means is provided around the shaft. The coil spring 554 is locked between an annular plate 552B disposed in a step 552A on the valve passage 552 side and a seal holding portion 551C, and the valve rod 551 is connected to the valve passage 552 as shown in FIG. The valve rod 551 is urged toward the insertion port 323A while being pushed inside. There is a gap SP2 between the valve stem main body 551A and the coil spring 554 and the inner peripheral surface of the valve passage 552, and it is possible to conduct pressure from the second introduction path 362 to the second lead-out path 372. .

The seal holding portions 551B and 551C are each formed with a radially reduced groove portion, and the first seal portion 581 and the second seal portion 382, which are ring-shaped rubbers, are respectively formed around the groove portion of the valve passage 552. It is interposed between the inner walls.
The knob 553 is formed with a diameter smaller than the diameter of the seal holding portion 551C.
Further, a plate-like member 555 having an insertion hole 555A through which the knob 553 is inserted is provided, and this plate-like member 555 is attached around the insertion port 323A with screws 555B.

  In such a pressure equalizing valve 55, when the coil spring 554 is restored as shown in FIG. 14A, the first seal portion 581 is positioned between the first lead-out path 371 and the second introduction / lead-out paths 362 and 372. Since the first path P1 and the second path P2 are partitioned by the first seal portion 581, the first path P1 and the second path P2 are closed, and the differential pressure between these paths can be measured. It is in a state.

In order to change from the differential pressure state to the pressure equalization state, the knob 553 is pushed into the valve passage 552 so that the end portion of the seal holding portion 551B is in contact with the intermediate portion 361A of the first introduction passage 361. As a result, the first seal portion 581 slides between the first introduction path 361 and the first lead-out path 371, and the guiding pressure between these introduction and lead-out paths 361 and 371 is blocked by the first seal portion 581. On the other hand, the first lead-out path 371 communicates with the second lead-in path 362 and the second lead-out path 372 and is in a state where pressure is equalized.
At this time, the first seal portion 581 is inserted into the first introduction path 361 to partition the first introduction path 361 and the first lead-out path 371, and in the communication space in the pressure equalized state, the fluid on the second path P2 side on one side Since only the pressure of FL acts and the pressure on the first path P1 side does not act, the flow of the fluid FL does not occur in the communication space (pressure equalizing path). As described above, when the first introduction path 361 is interrupted, fluid flows between the first introduction path 361 and the second introduction path 362 during pressure equalization, and the first introduction path 361 and the second introduction path 361 It is possible to prevent the pressure equalization path between the 362 and the 362 from becoming a throttle and causing a differential pressure.
As described above, the valve passage 552 is partitioned by the first seal portion 581 regardless of the differential pressure state or the pressure equalization state.

Here, when the valve rod 551 is pushed into the valve passage 552, the coil spring 554 contracts between the plate 552B and the seal holding portion 551C. Therefore, when the application of the external force pushing the valve rod 551 is stopped, the spring of the coil spring 554 The valve stem 551 is quickly retracted by the force, and the knob 553 protrudes from the insertion port 323A again. This shifts to the differential pressure state.
When the valve rod 551 is biased by the coil spring 554 and returns to the original position, the seal holding portion 551C comes into contact with the plate-like member 555, so that the valve rod 551 does not come out of the insertion port 323A.

According to this embodiment, in addition to the effect by 1st Embodiment, there exist the following effects.
(11) Since the first seal portion 581 used as the valve body of the pressure equalizing valve 55 is in close contact with the inner peripheral surface of the valve passage 552 due to its elasticity, the pressure equalizing valve 55 is reliably opened and closed, and differential pressure measurement is performed. Can be done accurately.

(12) After the valve rod 551 is pushed into the valve passage 552 to equalize the pressure, when the external force application to the valve rod 551 is stopped, the valve rod 551 returns to the original position by the biasing force of the coil spring 554. The opening / closing operation can be performed more reliably.

(13) Further, a plate-like member 555 is provided in the insertion port 323A, and the tab 553 is inserted into the plate-like member 555, whereby the seal holding portion 551C having a larger diameter than the knob 553 is moved to the outside of the insertion port 323A Therefore, detachment of the valve stem 551 from the base 32 can be prevented.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS.
The pressure equalizing valve of this embodiment is provided with a cylindrical member through which a valve rod is inserted in the pressure equalizing valve 55 of the second embodiment.
FIG. 15 is a side sectional view of the pressure equalizing valve 65 in the present embodiment.
In the valve passage 552 of the pressure equalizing valve 65, a cylindrical member 656 extending between the first lead-out path 371 and the second introduction / lead-out paths 362 and 372 is provided along the inner peripheral surface.

The cylindrical member 656 is made of SUS, and the corners inside the opening ends on both ends are chamfered, and a contacted surface 656B on which the valve rod 651 is contacted is formed between these chamfered portions 656A. Yes.
A groove for fitting a rubber O-ring 656C is formed on the outer peripheral surface of the cylindrical member 656, and the cylindrical member 656 is held in close contact with the inner peripheral surface of the valve passage 552 by the O-ring 656C. . Further, the pressure in each of the first path P1 and the second path P2 is sealed by the O-ring 656C.
A plate 656D is disposed on the end surface of the cylindrical member 656 on the insertion port 323A side.

In the present embodiment, the tubular member 656 is disposed in the valve passage 552. The diameter of the valve stem body 651A is smaller than the size in the second embodiment. The configuration is substantially the same as the configuration of the valve stem 551 in the second embodiment. That is, the valve stem 651 includes a valve stem main body 651A, seal holding portions 651B and 551C on both ends of the valve stem main body 651A, and a knob 553 formed continuously with the seal holding portion 551C. A coil spring 554 is provided around the axis of the valve stem body 651A.
The valve stem main body 651A has an enlarged diameter on the insertion port 323A side, and an inclined surface 651E is formed in this portion.

  As the diameter of the valve stem body 651A is reduced, a portion of the valve passage 552 that is closer to the first introduction path 361 than the diameter at the intersection 371A between the first introduction path 361 and the first lead-out path 371. The diameter is reduced, and the diameter of the reduced diameter portion 361B corresponds to the diameter of the first seal portion 581 disposed in the seal holding portion 651B.

  In such a pressure equalizing valve 65, when the coil spring 554 is restored as shown in FIG. 16A and the valve rod 651 is pulled out from the valve passage 552, the first seal portion 581 is brought into contact with the tubular member 656. The pressure equalizing valve 65 is in close contact with the surface 656B and is in close contact. That is, the differential pressure between the first path P1 and the second path P2 can be measured.

  When changing from the differential pressure state to the pressure equalization state, the knob 553 is pushed into the valve passage 552 to bring the end of the seal holding portion 651B into contact with the intermediate portion 361A of the first introduction path 361. On the opposite side of the valve stem body 651A, the inclined surface 651E of the valve stem body 651A faces the chamfered portion 656A of the tubular member 656. In this state, the guiding pressure between the first introduction path 361 and the first lead-out path 371 is blocked by the first seal portion 581, while the first lead-out path 371 has the second lead-in path 362 and the second lead-out path 372. The pressure is equalized.

  Here, when the valve rod 651 advances and retreats along the valve passage 552, the first seal portion 581 passes through the inside of the cylindrical member 656, and then the intersection between the first introduction path 361 and the first outlet path 371. In 371A, it passes through a position away from the opening end 371B of the first lead-out path 371. That is, there is no possibility that the first seal portion 581 is damaged and cut by the opening end 371B.

According to this embodiment, in addition to the effects of the above-described embodiments, the following effects can be obtained. (14) Since the cylindrical member 656 is disposed in the vicinity of the opening end 371B of the first outlet passage 371, problems such as the first seal portion 581 being caught by the opening end 371B and being damaged are prevented, and the valve rod 651 is prevented. Can be smoothly advanced and retracted.
That is, when the first lead-out path 371 or the like is drilled in the base 32 with a drill or the like, burrs or the like are likely to occur, but in order to prevent damage to the first seal portion 581 due to the burrs or the like, such a cylindrical member It is effective to provide 656.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIGS.
The pressure equalizing valve 75 according to the present embodiment is a valve rod 651 of the pressure equalizing valve 65 according to the third embodiment in which a third seal portion 783 is provided on the more advanced side of the valve rod 651 than the first seal portion 581.
FIG. 17 is a side sectional view of the pressure equalizing valve 75 in the present embodiment.
A seal holding portion 751D is formed at the tip of the valve rod 751 of the pressure equalizing valve 75, and a third seal portion 783 is disposed on the seal holding portion 751D. Thus, by providing the third seal portion 783, the length of the valve stem 751 is longer than the valve stem 651 in the third embodiment, and the reduced diameter portion in the tip of the valve stem 751 and the first introduction path 361. The distance from 361B is shortened.
The other configuration of the valve stem 751 is substantially the same as the configuration of the valve stem 651 in the third embodiment.
Note that the first lead-out path 371 is provided at a position between the third seal portion 783 and the second lead-out path 372 in the pressure equalized state shown in FIG. 18B, and along the radial direction of the valve passage 652. It extends. By arranging the first lead-out path 371 and the second lead-out path 372 with respect to the valve passage 552, the first lead-out path 371 and the second lead-out path 372 can be disposed sufficiently close to each other, and the pressure equalizing valve 75 can be downsized. , And speeding up and optimizing pressure equalization.

  In such a pressure equalizing valve 75, when the valve rod 751 is pulled out from the valve passage 652 as shown in FIG. 18A, the first seal portion 581 is covered by the tubular member 656 as in the third embodiment. The pressure equalizing valve 75 is in close contact with the contact surface 656B, and is in a closed state. That is, the differential pressure between the first path P1 and the second path P2 can be measured.

  When changing from the differential pressure state to the pressure equalization state, the knob 553 is pushed into the valve passage 652 as described above. Then, the first seal portion 581 moves to the intersection 371A between the first introduction path 361 and the first lead-out path 371. At this time, since the third seal portion 783 provided at the tip of the valve stem 751 is in close contact with the reduced diameter portion 361B in the first introduction path 361, the push amount is shorter than the push amount of the valve rod in each of the above embodiments. The first introduction path 361 and the first lead-out path 371 are blocked, and the first lead-out path 371 is communicated with the second introduction path 362 and the second lead-out path 372 so that the pressure is equalized. That is, since it is not necessary to move the first seal portion 581 to the first introduction path 361 to block the first introduction path 361 and the first lead-out path 371, the stroke for moving the valve rod 751 forward and backward can be reduced.

  According to this embodiment, in addition to the effects of the above-described embodiments, the following effects can be obtained. (15) In the differential pressure state, the valve passage 652 is partitioned by the first seal portion 581, while in the pressure equalization state, the valve passage 652 is partitioned by the third seal portion 783. Accordingly, the first seal portion 581 is disposed between the first lead-out path 371 and the second introduction / lead-out paths 362 and 372 during differential pressure measurement, and moves so as to be inserted into the first lead-in path 361 from this position. As a result, the dimension (stroke) in which the valve stem 751 advances and retreats can be shortened and the operation of the valve stem 751 can be simplified compared to the case where the pressure is equalized.

[Fifth Embodiment]
Next, a fifth embodiment of the present invention will be described with reference to FIGS.
In the pressure equalizing valve 85 of the present embodiment, a part of the configuration of the pressure introduction path and the lead-out path is different from that of each of the embodiments described above, and a new seal member is arranged accordingly.

FIG. 19 is a side sectional view of the pressure equalizing valve 85 in the present embodiment.
First, in the present embodiment, the positions where the second introduction path 362 and the second lead-out path 372 intersect with the valve passage 652 are separated from each other. Specifically, the second introduction path 362 intersects the valve passage 652 between the second lead-out path 372 and the insertion port 323A.

A cylindrical member 856 is provided along the valve passage 652 so as to straddle both side portions where the second outlet passage 372 intersects the valve passage 652.
FIG. 20 is a perspective view of the tubular member 856. FIG.
A reduced diameter portion 856E is formed at the center of the cylindrical member 856, and this reduced diameter portion 856E matches the position of the opening end 372B communicating with the valve passage 652 of the second outlet passage 372 as shown in FIG. Are arranged as follows. The reduced diameter portion 856E is formed with a hole 856F penetrating along the direction in which the second lead-out path 372 extends.
Grooves into which the O-ring 656C is fitted are respectively formed on the outer peripheral surfaces of both sides of the reduced diameter portion 856E in the cylindrical member 856.

  On the other hand, the valve stem 851 is formed with a seal holding portion 851E between the first seal portion 581 and the second seal portion 382, and the fourth seal portion 884 is disposed on the seal holding portion 851E. The diameter of the fourth seal portion 884 corresponds to the inner diameter of the cylindrical member 856.

In such a pressure equalizing valve 85, when the valve rod 851 is pulled out from the valve passage 652 as shown in FIG. 21A, the first seal portion 581 is covered by the tubular member 856 as in the fourth embodiment. The pressure contact valve 656B is in close contact with the contact surface 656B and is closed as the pressure equalizing valve 85. That is, the differential pressure between the first path P1 and the second path P2 can be measured.
At this time, since the fourth seal portion 884 is located in the enlarged space in the valve passage 652 between the end portion of the tubular member 856 and the insertion port 323A, the second introduction path 362, the second lead-out path 372, and the like. A space between them is a communication space in which pressure can be guided through a hole 856F of the cylindrical member 856.

When changing from the differential pressure state to the pressure equalization state, the knob 553 is pushed into the valve passage 652. Then, as described above, the third seal portion 783 is in close contact with the reduced diameter portion 361B in the first introduction path 361, and the first introduction path 361 and the first outlet path 371 are blocked.
At this time, the fourth seal portion 884 is brought into close contact with the abutted surface 656B of the cylindrical member 856, and the second introduction path 362 and the second lead-out path 372 are blocked.
As a result, the first introduction path 361 and the first lead-out path 371 are blocked in the first path P1, and the second lead-in path 362 and the second lead-out path 372 are blocked in the second path P2, and the first lead-out path 371. Only the second lead-out path 372 communicates with each other.

  In addition, since the cylindrical member 856 is provided when the valve rod 851 is advanced and retracted, the first seal portion 581 and the fourth seal portion 884 are the opening end 371B of the first outlet passage 371 and the second outlet passage 372, respectively. The first seal portion 581 and the fourth seal portion 884 do not break at the open ends 371B and 372B.

According to this embodiment, in addition to the effects of the above-described embodiments, the following effects can be obtained. (16) Since the second lead-out path 372 is partitioned from the second introduction path 362, pulsation is prevented and the pressure is extremely stable, so that the pressure difference of the fluid FL can be quickly and easily set to “0”. .
In addition, the fourth seal portion 884 can partition the second introduction path 362 and the second lead-out path 372 with a simple structure.

[Sixth Embodiment]
Next, a sixth embodiment of the present invention will be described with reference to FIG.
The present embodiment is different from the above embodiments in the introduction of fluid pressure, the layout of the derivation path, and the like.
FIG. 22 is a side sectional view of the pressure equalizing valve 95 in the present embodiment. The first lead-out path 962 extends along the extending direction of the valve passage 352 and forms a first path P1 together with the first lead-in path 961 extending in a direction intersecting with the first lead-out path 962. As for the second path P2, as in the fifth embodiment, the positions of the second introduction path 362 and the second lead-out path 372 intersecting with the valve passages 352 are different, and the second lead-out path 372 has a valve path 352. , The first introduction path 961 and the second introduction path 362 are formed.

On the other hand, the pressure equalizing valve 95 is provided with a seal portion 980 at the tip of the valve rod 351.
Further, the knob 953 is formed in a hexagonal cross section, and a hole 953A having a rectangular shape in plan view is formed on the end face of the knob 953, and the knob 953 can be easily turned with a tool such as a wrench. As a result, the valve stem 351 is screwed forward and backward.
Other configurations of the pressure equalizing valve 95 are the same as those of the pressure equalizing valve 35 in the first embodiment.
Also according to this embodiment, substantially the same effect as that of the first embodiment can be obtained.

[Seventh Embodiment]
Next, a seventh embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 23, the flowmeter 2 of the present embodiment is characterized in that a holding member 73 that holds a temperature sensor 313 is provided. FIG. 23 is a diagram corresponding to FIG. 2 illustrating the first embodiment. In FIG. 23, the main body 30 is covered with a case 43 in which the display calculation unit 40 is incorporated.
The flow meter 2 includes a flow rate detection unit 70 instead of the flow rate detection unit 10 provided in the flow meter 1 of the first embodiment.

The flow rate detection unit 70 is of a type that is sandwiched and attached between two pipes 110, a pipe member 71 having a flow path connection part 711 at each end to which a flange 110A of the pipe 110 is attached, and a pipe member 71 and a metal pressure guiding portion 72 which is joined to the main body 30 (FIG. 2) via the adapter 20 and has an upstream extraction hole 721 and a downstream extraction hole 722 formed therein.
Here, the axial length of the pipe member 71 of the flow meter 2 of the present embodiment is shorter than the length of the case 43 in the same direction. That is, the axial length of the pipe member 71 is so short that the case 43 does not fit between the flange 110A and the flange 110A. For this reason, the thickness dimension of the pressure guiding part 72 is provided thicker than the dimension in which the flange 110 </ b> A protrudes outside the opening of the pipe 110. Accordingly, the length of the temperature sensor 313 and the length of the extraction hole 721 into which the temperature sensor 313 is inserted are increased.

FIG. 24 is a perspective view of the holding member 73 that holds the temperature sensor 313. The holding member 73 is formed in a substantially cylindrical shape as an injection-molded product made of PTFE (polytetrafluoroethylene), which is a low heat conductive material, and has a slit 731 formed along the axial direction. That is, the holding member 73 has a substantially C-shaped cross section, and the temperature sensor 313 is inserted therein. At this time, the slit 731 constitutes a communication path communicating with the internal space of the take-out hole 721, and the pressure of the fluid FL can be transmitted from the inside of the pipe member 71 to the sensor unit 31 through the slit 731.
The material of the holding member 73 is selected in consideration of the corrosion resistance against the fluid FL and the heat conduction efficiency. PTFE, which is the material of the holding member 73 of this embodiment, has a thermal conductivity as low as about 10 times that of air.

  Flange portions 732 and 733 are formed on both axial ends of the holding member 73, and a small diameter portion 734 is formed between the flange portions 732 and 733. Here, only the side surfaces of the flange portions 732 and 733 are in contact with the inner peripheral surface of the extraction hole 721. An enlarged diameter portion 732 </ b> A having an outer diameter larger than the diameter of the extraction hole 721 is formed on the outer peripheral portion of the one flange portion 732. Further, the end portion 732B on the flange portion 732 side of the holding member 73 is formed to be stepped with respect to the enlarged diameter portion 732A.

24, the holding member 73 is inserted into the take-out hole 721 from the lower flange portion 733 side, and the temperature sensor 313 is inserted into the holding member 73 from the upper flange portion 732 side. At this time, approximately half of the flange portion 732 enters the take-out hole 721 and the enlarged diameter portion 732A is hooked on the edge of the take-out hole 721, and the holding member 73 is not inserted into the take-out hole 721 any more. That is, the enlarged diameter portion 732A serves as a stopper. In this state, an O-ring 735 (FIG. 23) is disposed around the enlarged diameter portion 732 </ b> A, and the space between the pressure guiding portion 72 and the adapter 20 is sealed by the O-ring 735. In addition, since the dimension in which the enlarged diameter portion 732A protrudes from the extraction hole 721 is smaller than the thickness of the elastically deformed O-ring 735, the sealing performance of the O-ring 735 is not hindered.
Further, when the adapter 20 is attached, the end portion 732B of the holding member 73 protruding from the take-out hole 721 functions as a positioning guide.

  The outer diameters of the flange portions 732 and 733 are slightly larger than the inner diameter of the take-out hole 721, but the holding member 73 can be squeezed at the slit 731 and inserted into the take-out hole 721. In addition, the inner diameter of the holding member 73 is slightly larger than the outer diameter of the temperature sensor 313, but when the holding member 73 is inserted into the take-out hole 721, the interval between the slits 731 is narrowed. Since the outer diameter of the temperature sensor 313 is substantially the same, the temperature sensor 313 is securely held.

  According to this embodiment, in addition to the effects of the above-described embodiments, the following effects can be obtained. (17) By providing the holding member 73 around the temperature sensor 313, the temperature sensor 313 can be prevented from swinging obliquely with respect to the longitudinal direction. That is, the temperature sensor 313 is held in a stable posture even when the thickness of the pressure guiding portion 72 is large and the extraction hole 721 is long as in the present embodiment. Here, even when the flow rate of the fluid FL in the flow rate detection unit 70 is high, the temperature sensing element 313G at the tip of the temperature sensor 313 can be maintained at a position facing the flow path 13 or a position slightly protruding toward the flow path 13. . Further, since the temperature sensor 313 is held by the holding member 73 as described above, it is possible to prevent the temperature sensor 313 from being damaged due to vibration of the pipe 110 and the like, and to improve vibration resistance.

(18) Since the holding member 73 is simply configured as having a substantially cylindrical shape and having a slit 731 so that the temperature sensor 313 can be held and the pressure of the fluid FL can be taken out. 73 component costs can be reduced. Further, since the communication path capable of transmitting the pressure of the fluid FL is formed by the slit 731, the extraction hole having a diameter that is not significantly different from the diameter of the extraction hole 131 when the holding member 73 is not provided (such as FIG. 2). Since both the temperature sensor 313 and the holding member 73 can be provided in the 721, downsizing of the flow meter 2 is not hindered.

(19) Further, since the holding member 73 is configured to include the flange portions 732 and 733 and the small diameter portion 734 that does not contact the inner peripheral surface of the take-out hole 721, the holding member 73 is removed from the pressure guiding portion 72. Thus, the temperature influence on the flow rate measurement due to the heat transmitted to the temperature sensor 313 can be reduced.

(20) Since the material of the holding member 73 is formed of PTFE having a low thermal conductivity, the temperature influence from the metal pressure guiding portion 72 to the temperature sensor 313 can be minimized, and high accuracy can be realized in the flow rate measurement. it can.

[Modification of the present invention]
Although the best configuration, method and the like for carrying out the present invention have been disclosed in the above description, the present invention is not limited to this. That is, the invention has been illustrated and described primarily with respect to particular embodiments, but may be configured for the above-described embodiments without departing from the scope and spirit of the invention. Various modifications and improvements can be made by those skilled in the art in terms of materials, quantity, and other detailed configurations.

For example, in the pressure equalizing valve 55 in the second embodiment, a plate-like member 555 is provided in order to prevent the valve rod 551 from coming off from the valve passage 552, but FIG. 25 using this plate-like member 555 is used. With the structure shown, the pushing amount of the valve rod 551 into the valve passage 552 can be regulated to a predetermined amount.
25 is a perspective view showing the plate-like member 555 and the knob 553, and the plate-like member 555 is formed with a substantially circular insertion hole 555A through which the knob 553 is inserted. Note that screws 555B (FIG. 13) are inserted through the two through holes 555C formed at both ends of the plate-like member 555.
Here, a concave notch 955D is formed as a fitting portion in the insertion hole 555A of the plate-like member 555, and a convex rib 953F that fits the notch 955D is provided on the outer peripheral surface of the knob 553 as a shaft. It is formed along the direction.

According to such a configuration, the valve rod 551 is pushed into the valve passage 552 against the biasing force of the coil spring 554 (FIG. 13), and the rib 953F of the knob 553 and the notch 955D of the insertion hole 555A are fitted. When the knob 553 is rotated around the axis in a state where it is not, the rib 953F of the knob 553 that attempts to return to the original position by the urging force is brought into contact with the plate surface of the plate-like member 555 and locked. That is, with a simple structure such as concave-convex fitting, the position of the valve stem 551 can be held at a predetermined position where differential pressure can be measured even when no external force is applied to the valve stem 551. By changing the length of the rib 953F, the amount of insertion of the valve rod 551 into the valve passage 552 can be appropriately changed.
The structure shown in FIG. 25 can be applied to the third to seventh embodiments.

In each of the embodiments described above, the orifice 14 is used as the differential pressure generating means. However, the present invention is not limited to this, and a pitot tube, a wake pitot tube, a laminar flow element, or the like may be used.
Furthermore, although the coil spring 554 of the compression spring is used in the above-described embodiment, the means for biasing the valve rod is not limited to this, and a tension spring is used according to the introduction of pressure, the arrangement of the outlet path, and the like. It is also possible to do.

  Further, as described above, the flow meter 1 (FIG. 1) in the above embodiment has an aluminum case 43 and is driven by a battery stored in the case 43, and is a liquid crystal display type display. Although the calculation part 40 was incorporated in the case 43, in the flowmeter of this invention, the material of a case, the kind of power supply, the form of mounting regarding a display calculation part and a sensor part, etc. are not limited to these at all. For example, a resin case can be favorably employed, and a display means such as an LED (Light Emitting Diode) can be employed in addition to the liquid crystal panel in the display calculation unit. The display panel and operation panel of the display calculation unit, the circuit board for driving these panels, the drive circuit board of the sensor unit, and the circuit block on which calculation means such as a CPU are mounted are all provided in the base 32 of the sensor unit 31. The case may be attached to the base 32 of the sensor unit 31 so as to cover the circuit block. Of course, an external power source can be used as a power source for driving such a circuit block.

  Finally, the description limited to the shape, material and the like disclosed above is an example for easy understanding of the present invention, and does not limit the present invention. The description by the name of the member which removed the limitation of part or all of the material and the like is included in the present invention.

  The pressure equalizing valve of the present invention can be used for a differential pressure type flow meter, and can be used by being incorporated in a fluid control system or the like as required.

The perspective view of the flowmeter in 1st Embodiment of this invention. The sectional side view of the flowmeter in the embodiment. The sectional side view of the flow volume detection part in the embodiment. The perspective view of the flow volume detection part in the said embodiment. The sectional side view of the main-body part and adapter in the said embodiment. The figure which shows the one state which attaches a main-body part to a flow volume detection part with an adapter in the said embodiment. The figure which shows the other state which attaches a main-body part to a flow volume detection part with an adapter in the said embodiment. The figure which shows the joint surface with the adapter of the main-body part in the said embodiment. Conceptual diagram of sensor unit and flow rate detection unit in the embodiment The elements on larger scale of FIG. Sectional drawing of the temperature sensor by the XI-XI line of FIG. The side view of the pressure equalization valve in the said embodiment. (A) shows the differential pressure state with the pressure equalizing valve closed, and (B) shows the pressure equalized state with the pressure equalizing valve opened. The sectional side view of the pressure equalizing valve in 2nd Embodiment of this invention. The side view of the pressure equalization valve in the said embodiment. (A) shows the differential pressure state with the pressure equalizing valve closed, and (B) shows the pressure equalized state with the pressure equalizing valve opened. The sectional side view of the pressure equalizing valve in 3rd Embodiment of this invention. The side view of the pressure equalization valve in the said embodiment. (A) shows the differential pressure state with the pressure equalizing valve closed, and (B) shows the pressure equalized state with the pressure equalizing valve opened. The sectional side view of the pressure equalizing valve in 4th Embodiment of this invention. The side view of the pressure equalization valve in the said embodiment. (A) shows the differential pressure state with the pressure equalizing valve closed, and (B) shows the pressure equalized state with the pressure equalizing valve opened. The sectional side view of the pressure equalizing valve in 5th Embodiment of this invention. The perspective view of the valve rod of the pressure equalizing valve in the said embodiment. The side view of the pressure equalization valve in the said embodiment. (A) shows the differential pressure state with the pressure equalizing valve closed, and (B) shows the pressure equalized state with the pressure equalizing valve opened. The side view of the pressure equalization valve in 6th Embodiment of this invention. (A) shows the differential pressure state with the pressure equalizing valve closed, and (B) shows the pressure equalized state with the pressure equalizing valve opened. The sectional side view of the flowmeter in 7th Embodiment of this invention. The perspective view of the holding member in the said embodiment. The figure which shows the structure which concerns on the discipline of the pushing amount to the valve channel | path of the valve stem in the modification of this invention.

Explanation of symbols

1 and 2 Flowmeters 10 and 70 Flow rate detection parts 11 and 71 Pipe member 12 Plate-like part (main body attachment part)
13 Channel 14 Orifice (Differential pressure generating means)
20 Adapter 22 Body side joint 30 Body part 31 Sensor part 32 Base (valve box)
35 Pressure equalizing valve 40 Display calculation section 41 Calculation means 43 Case 72 Pressure guiding section 73 Holding member 100, 110 Pipe 111 Female thread section (flow path connection section)
131, 132, 721, 722 Extract hole 201, 202 Extract hole 213 Joint surface 224 O-ring (seal member)
224B Inner peripheral surface 224C Protrusion 311 Differential pressure sensor 312 Gauge pressure sensor 313 Temperature sensor 313G Temperature sensing element 313E Packing (low thermal conductivity member)
314 Absolute Pressure Sensors 321 and 322 Extraction Hole 323A Insertion Port 351 Valve Rod 351H Taper (Valve)
352 Valve passage 353 Knob 361 First introduction path 362 Second introduction path 371 First outlet path 371B Open end 372 Second outlet path 382 Second seal part 431 Liquid crystal panel part (display means)
554 Coil spring (biasing means)
555 Plate-like member 555A Insertion hole 581 First seal portion 656 Tubular member 711 Flow path connection portion 731 Slit 732, 733 Flange portion 734 Small diameter portion 783 Third seal portion 884 Fourth seal portion 955D Notch (fitting portion)
953F Rib (fitting part)
FL fluid P1 first path P2 second path SP clearance

Claims (20)

A valve box having a valve passage formed therein;
In this valve box, a rod-shaped member inserted from an insertion port provided on one end side in the extending direction of the valve passage, having a valve body around an axis, and the valve according to advancement and retraction in the axial direction A valve stem that partitions the valve passage by a body,
The valve box has a first introduction path and a second introduction path through which the fluid pressure is introduced and communicated with the valve passage, and a first lead-out path and a second passage through which the fluid pressure is discharged from the valve passage, respectively. A lead-out path is formed,
The first introduction path and the first lead-out path constitute a first path, and the position in the axial direction of the valve rod between the one opening on the valve passage side and the other opening on the valve passage side is Different from each other
The second introduction path and the second lead-out path constitute a second path,
According to the advance and retreat of the valve stem,
A differential pressure state in which the first path and the second path are partitioned to measure a differential pressure between the first path and the second path;
The first derivation path is partitioned from the first introduction path and communicated with the second path, and is switched to a pressure equalization state in which the first derivation path and the second derivation path are equalized. A pressure equalizing valve for measuring differential pressure. In the pressure equalizing valve for differential pressure measurement according to claim 1,
The valve body is elastic and is a seal portion interposed between an outer peripheral surface of the valve stem and the valve box,
The seal portion is disposed on the insertion port side to seal the pressure of fluid in the valve passage, and the first seal portion that partitions the first path and the second path in the differential pressure state. A pressure equalizing valve for measuring a differential pressure, comprising a second seal portion. In the pressure equalizing valve for differential pressure measurement according to claim 2,
The seal portion is configured to include a third seal portion provided on one end side in the extending direction of the valve passage from the first seal portion,
The pressure equalizing valve for differential pressure measurement, wherein the third seal portion is disposed in the first introduction path when in the pressure equalized state. In the pressure equalizing valve for differential pressure measurement according to claim 2 or 3,
The valve passage extends from one end to the other end along the axial direction of the valve stem,
The first lead-out path is a direction that intersects the axial direction of the valve stem between one of the first seal part and the third seal part in the pressure equalized state and the second lead-out path. A pressure equalizing valve for measuring a differential pressure, characterized by extending along a radial direction of the passage. In the pressure equalizing valve for differential pressure measurement according to any one of claims 1 to 4,
The second introduction path and the second lead-out path are separated from each other at positions intersecting the valve passage,
The pressure equalizing valve for differential pressure measurement, wherein the second introduction path and the second lead-out path are partitioned in the pressure equalization state. In the pressure equalizing valve for differential pressure measurement according to claim 5,
The seal portion includes a fourth seal portion provided between the second introduction path and the second lead-out path in the valve passage,
The pressure equalizing valve for measuring a differential pressure, wherein the second introduction path and the second lead-out path are partitioned by the fourth seal portion in the pressure equalization state. In the pressure equalizing valve for differential pressure measurement according to any one of claims 1 to 6,
The valve box has a cylindrical member into which the valve stem is inserted,
The tubular member is provided along the valve passage in the vicinity of at least one of the first lead-out path, the second lead-in path, and the second lead-out path. Pressure valve. In the pressure equalizing valve for differential pressure measurement according to any one of claims 2 to 7,
The seal portion other than the second seal portion has a gap with at least one of the first lead-out path, the second lead-in path, and the open end where the second lead-out path communicates with the valve passage. A pressure equalizing valve for measuring a differential pressure, which is arranged. In the pressure equalizing valve for differential pressure measurement according to any one of claims 1 to 8,
The pressure equalizing valve for measuring a differential pressure, wherein the valve stem has a knob protruding from the insertion port along an axial direction thereof. The pressure equalizing valve for differential pressure measurement according to claim 9,
A plate-like member having an insertion hole is provided at the opening end of the insertion port,
In the knob, the diameter of the axial end of the valve stem is reduced, and the movement of the valve stem to the outside of the insertion port is restricted by being inserted through the insertion hole. A pressure equalizing valve for differential pressure measurement. In the pressure equalizing valve for differential pressure measurement according to any one of claims 1 to 10,
A pressure equalizing valve for differential pressure measurement, characterized in that a biasing means for biasing the valve stem along the axial direction is provided. The pressure equalizing valve for differential pressure measurement according to claim 11,
The knob has a substantially cylindrical shape in cross section, and a fitting portion that fits the insertion hole is formed along the axial direction on the outer peripheral surface of the proximal end.
The valve stem is rotated around the shaft in a state in which the fitting portion is disengaged from the insertion hole, and the fitting portion is locked to the plate-like member by the urging force of the urging means. A pressure equalizing valve for measuring a differential pressure. A flow rate detector having differential pressure generating means for generating a differential pressure in the fluid to be detected that passes;
A differential pressure sensor that measures a differential pressure generated in the fluid to be detected by the flow rate detection unit, a gauge pressure sensor that measures the gauge pressure of the fluid to be detected, a temperature sensor that measures the temperature of the fluid to be detected, and atmospheric pressure A sensor unit having an absolute pressure sensor for measuring
A differential pressure type flow meter including a calculation unit that calculates a flow rate of the fluid to be detected based on a signal transmitted from the sensor unit, and a display calculation unit that has a display unit that displays the flow rate calculated by the calculation unit Because
A differential pressure type flow meter comprising the pressure equalizing valve for measuring the differential pressure according to any one of claims 1 to 12. The differential pressure type flow meter according to claim 13,
The sensor unit and the display calculation unit are integrated and configured as a main body unit, and are joined to the flow rate detection unit,
The flow rate detection unit includes a flow channel connection unit that is provided with the differential pressure generating unit and is connected to a flow channel of the fluid to be detected, and a main body attachment unit that is joined to the main body unit,
The main body attachment portion is formed with respective extraction holes that communicate with the flow path on the upstream side and the downstream side of the differential pressure generating means, respectively, and extract the pressure of the fluid to be detected to the sensor portion,
One of the extraction holes extends linearly toward the flow path at a substantially central position of a joint surface with the main body of the flow rate detection unit,
The temperature sensor is formed in a rod shape and has a temperature sensing element on one end side, and one end side is inserted into the take-out hole arranged at a substantially central position of the joint surface so that the temperature sensing element faces the flow path. ,
The differential pressure type flow meter, wherein the main body part and the flow rate detection part can be joined even in a state where the temperature sensor is rotated around an axis. The differential pressure type flow meter according to claim 14,
A differential pressure type flow meter, wherein a low thermal conductivity member having a low thermal conductivity is disposed between the temperature sensitive element and the inner peripheral surface of the extraction hole. The differential pressure type flow meter according to claim 14 or 15,
An annular seal member that seals the fluid to be detected inside the extraction hole is provided on the inner periphery of the extraction hole,
The seal member has a plurality of protrusions on its inner peripheral surface, and the temperature sensitive element is held and fixed between these protrusions. The differential pressure type flow meter according to any one of claims 13 to 16,
The flow rate detection unit is provided with the differential pressure generating means and communicates with the flow path connecting portion connected to the flow path of the fluid to be detected, and the flow path upstream and downstream of the differential pressure generating means. And each of the extraction holes for taking out the pressure of the fluid to be detected into the sensor part, and a pressure guiding part formed respectively.
One of the extraction holes extends linearly from the sensor part toward the flow path,
The temperature sensor is formed in a rod shape and has a temperature sensing element on one end side, one end side is inserted into one of the linearly extending extraction holes, and the temperature sensing element faces the flow path,
The one take-out hole is provided with a holding member that holds the temperature sensor along the longitudinal direction,
At least one of the outer peripheral surface and the inner peripheral surface of the holding member is formed with a communication path that extends along the longitudinal direction of the temperature sensor, communicates with the take-out hole, and can transmit the pressure of the detected fluid. A differential pressure type flow meter characterized by having The differential pressure type flow meter according to claim 17,
The holding member is formed in a substantially cylindrical shape into which the temperature sensor is inserted, and has a slit along the axial direction of the holding member,
The differential pressure type flow meter, wherein the communication path is constituted by the slit. The differential pressure type flow meter according to claim 17 or 18,
The holding member has a flange portion whose side surface contacts the inner peripheral surface of the take-out hole, and a small-diameter portion that is a portion other than the flange portion and has an outer diameter smaller than the inner diameter of the take-out hole. Differential pressure flow meter. The differential pressure type flow meter according to any one of claims 17 to 19,
The differential pressure type flow meter, wherein the holding member is made of a low thermal conductivity material having a low thermal conductivity.

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