JP4080246B2 - Flowmeter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an insert part for a joint and a flow meter, and more particularly to an insert part for a joint and a flow meter that require a sealing property with a case body.
[0002]
[Prior art]
FIG. 7 is an enlarged view of the embedded part of the insert part. When the joint 2 is formed on the synthetic resin case main body 1, the joint insert part 3 is formed of metal, and the joint insert part 3 is attached to the case main body 1. The joint strength of the joint insert part 3 is increased at the same time as the molding of the joint.
[0003]
By the way, in the joint 2 of such a flow meter, an external force in the rotational direction or the pulling-out direction acts on the joint insert part 3 via a connector (not shown) connected to the joint. A mesh-like knurling 4 is engraved on the outer peripheral surface of the joint insert part 3 so as to counter such external force.
[0004]
[Problems to be solved by the invention]
Since the joint insert part in a conventional flow meter or the like is configured as described above, when the case body 1 is molded by the knurled unevenness formed on the outer peripheral surface in order to obtain the rotational strength of the insert, The flow of the resin is disturbed on the peripheral surface of the joint insert part 3, the adhesion between the joint insert part 3 and the case body 1 is poor, and the sealing performance is lowered. In order to ensure sealing performance, it is possible to press-insert insert parts using an O-ring. However, the number of manufacturing steps increases, the resin is cracked by press-fitting insert parts, and the punching strength cannot be obtained. There was a problem.
[0005]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a joint insert component that is firmly coupled to the case body and that provides sufficient sealing performance.
[0006]
[Means for Solving the Problems]
The flowmeter according to the present invention has a flow path formed in the synthetic resin case main body, an insert part for a joint embedded in the synthetic resin case main body as an inlet port and an outlet port of the flow path, and facing the flow path. The joint insert component is provided with a knurled carved on the outer peripheral surface of the metal tube, and an annular recess provided in the middle in the axial direction of the outer peripheral surface, A boundary between the synthetic resin case main body and the joint insert part is formed on an end surface of the synthetic resin case main body, and an elastic member is provided between the synthetic resin case main body and the joint, and the joint insert When attaching the joint to a component, the elastic member is provided and sealed so as to cover the boundary .
[0007]
The flow meter according to the present invention has a plurality of annular grooves formed on the bottom surface of the annular recess.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below.
Embodiment 1 FIG.
1 is a conceptual exploded perspective view of a flowmeter in which a joint insert part according to the present invention is embedded, FIG. 2 is a longitudinal sectional view thereof, FIG. 3 is a sectional view taken along line AA in FIG. 2, and FIG. It is the perspective view which showed embodiment of insert components.
[0011]
As shown in FIG. 1, the flow meter includes a lid 11 whose one end is rotatably supported by the case body 10, a circuit board 12 attached to the case body 10, and the like.
[0012]
As shown in FIG. 1, the case body 10 has a recess 13 that opens upward at the top. A groove 15 that opens upward is formed in the bottom wall 14 of the recess 13, and holes 16 and 17 that extend downward are formed on the bottom surfaces of both ends of the groove 15. These holes 16, 17 constitute portions 18 a, 18 b of the flow path 18, and the lower ends of the holes 16, 17 are communicated with ports 19, 20 formed on the end surface of the case body 10, respectively.
[0013]
The ports 19 and 20 are formed by joint insert parts 21 and 21 embedded in the case body 10. This insert part 21 is formed of a metal tube. As shown in FIG. 4, the metal tubular body has an annular recess 23 formed in the middle in the axial direction of the outer peripheral surface, and an annular notch 24 formed on the outer peripheral surface of one end. A mesh knurling 25 is engraved on the outer peripheral surface excluding the recesses 23 and the notches 24. A female thread 26 is formed on the inner peripheral surface of each joint insert component 21.
[0014]
The joint insert part 21 formed in this way is embedded at the same time when the case body 10 of the flow meter is molded.
[0015]
In the flowmeter in which the joint insert part 21 is embedded in the case body 10 in this way, as shown in FIG. 5, the resin of the case body 10 enters the eyes of the knurl 25 and resists external force in the rotational direction. In addition, since the resin of the case body 10 enters the annular recess 23 and forms a labyrinth there, the sealing performance is high, and it is possible to sufficiently resist the external force in the removal direction.
[0016]
In the flow meter, the width c of the groove 15 and the widths of the holes 16 and 17 are the same, and the depth a of the groove 15 is set smaller than the gap b of the holes 16 and 17. A rib 27 is formed on the bottom wall 14 of the recess 13 along the periphery of the opening of the groove 15.
[0017]
On the other hand, as shown in FIG. 1, the lid body 11 has shafts 11 a and 11 a formed on the sides of one end, and the shafts 11 a and 11 a are formed in the side walls 28 and 28 of the recess 13. The case body 10 is rotatably supported by being inserted into the case body. A claw 11 b is formed at the tip of the lid 11.
The lid 11 closes the opening of the recess 13 by engaging the claw 11 b with a notch 28 b formed in the side wall 28 of the recess 13.
[0018]
The circuit board 12 is a ceramic board. On the upper surface of the circuit board 12, a connector 29 and elements having various functions are mounted. The circuit board 12 has an electric circuit (not shown) in the center of the lower surface. The microflow sensor 30 connected to the connector 29 is disposed by bonding or the like.
The microflow sensor 30 is a flow sensor in which a temperature measuring resistance element is arranged so as to sandwich a heater element, for example.
[0019]
Then, the circuit board 12 is placed on the rib 27 at the periphery of the opening of the groove 15 formed in the bottom wall 14 of the recess 13 and is fixed to the bottom wall 14 of the recess 13 by the adhesive 31 as shown in FIG. Is done. In this case, when the circuit board 12 is bonded to the rib 27, the excessive adhesive 31 is prevented from entering the flow path 18 by the rib 27, so that the peripheral surface of the circuit board 12 and the recess 13 are The gap between the side wall 28 and the circuit board 12 is securely bonded.
[0020]
In this way, the installed circuit board 12 completely closes the opening of the groove 15 and forms the flow path portion 18c of the flow path 18 with the circuit board 12 as one wall surface.
[0021]
The circuit board 12 is accommodated in the main body case 10 by covering the recess 13 with the lid 11 and engaging the claw 11 b of the lid 11 with the notch 28 b of the side wall 28.
[0022]
As shown in FIG. 5, in the flow meter configured in this way, a joint 33 of a hose 32 having, for example, a suction pad (not shown) at the tip is screwed onto the female thread 26 of the inlet port 19, A joint 35 of a hose 34 connected to a female pump 26 of the outlet port 20 is connected to a vacuum pump (not shown) or the like.
At that time, gaskets 36 and 36 as elastic members are interposed between the joint 33 and the case main body 10 and between the joint 35 and the case main body 10, respectively.
[0023]
When the vacuum pump is operated, the fluid is sucked from the inlet port 19 to the flow channel portion 18a of the flow channel 18, and then sucked to the vacuum pump through the flow channel portions 18c and 18b and the outlet port 20.
At that time, the fluid is first drifted in the flow path portion 18a. Next, a laminar flow is formed in the flow path portion 18c having a shallow depth and a reduced cross-sectional area of the flow path, and the flow state of the fluid is measured by the sensor 30, for example. The measured value is sent to a controller (not shown) via the connector 29, where a flow velocity value, that is, a flow rate is calculated.
For example, the flow rate is maximum when nothing is sucked into the suction pad, and the flow rate is almost zero when an object is sucked into the suction pad. Can be judged.
[0024]
In the present embodiment, an annular recess 23 is formed on the peripheral surface of the joint insert part 21 so as to constitute a labyrinth and to counter external forces in the pulling direction. As shown in FIG. If the annular groove 37 is formed on the bottom surface of the annular recess 23, the sealing effect can be further enhanced by increasing the area of the plane portion.
[0025]
Further, by covering the boundary T between the joint insert part 21 and the resin with the inside of the gasket 36, that is, with the gasket, leakage from the boundary T can be reliably prevented.
[0026]
【The invention's effect】
As described above, according to the present invention, the flow path formed in the synthetic resin case body, the joint insert part embedded in the synthetic resin case body as the inlet port and the outlet port of the flow path, and the flow path The joint insert component includes a knurling carved on the outer peripheral surface of the metal tube and an annular recess provided in the middle in the axial direction of the outer peripheral surface. Provided on the end surface of the synthetic resin case main body is a boundary between the synthetic resin case main body and the joint insert part, and an elastic member is provided between the synthetic resin case main body and the joint. when mounting the joint to the insert part for fittings, wherein the elastic member is so constructed as to seal provided so as to cover the boundary, embedded in a resin case body In this state, the resin sufficiently flows into the annular recess to ensure the seal between the case body and the insert part, and can sufficiently resist the external force applied to the insert part in the pulling direction. There is an effect.
Further, there is an effect that leakage from the boundary can be surely prevented as well as leakage from the boundary.
[0027]
According to the present invention, since a plurality of annular grooves are formed on the bottom surface of the annular recess, a labyrinth is formed between the annular recess and the case main body, and there is an effect that the sealing performance is further enhanced.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view conceptually showing a flow meter in which a joint insert part according to an embodiment of the present invention is embedded.
FIG. 2 is a longitudinal sectional view of the flow meter shown in FIG.
FIG. 3 is a cross-sectional view taken along line AA in FIG.
FIG. 4 is a perspective view showing an embodiment of a joint insert part according to the present invention.
FIG. 5 is a cross-sectional view showing a state in which a connector is connected to a joint of a flow meter according to the present invention.
FIG. 6 is a sectional view showing another embodiment of a joint insert part according to the present invention.
FIG. 7 is a cross-sectional view of a main part showing a state in which a conventional joint insert part is embedded in a case body such as a flow meter.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Case main body 2 Joint 3 Joint insert part 4 Knurl 10 Case main body 11 Lid 11a Shaft 11b Claw 12 Circuit board 13 Recess 14 Bottom wall 15 Groove 16, 17 Hole 18 Channel 18a, 18b, 18c Channel part 19, 20 Port 21 Insert component 23 Annular recess 24 Notch 25 Knurl 26 Female thread 27 Rib 28 Side wall 28a Hole 28b Notch 29 Connector 30 Microflow sensor 31 Adhesive 32 Hose 33 Joint 34 Hose 35 Joint 36 Gasket (elastic member)
37 annular groove

Claims (2)

A flow path formed in the synthetic resin case body,
Insert parts for joints embedded in the synthetic resin case body as the inlet port and outlet port of this flow path,
In a flowmeter having a sensor provided facing the flow path,
The joint insert part is provided with a knurled carved on the outer peripheral surface of the metal tube, and an annular recess provided in the middle in the axial direction of the outer peripheral surface,
A boundary between the synthetic resin case main body and the joint insert part is formed on an end surface of the synthetic resin case main body,
An elastic member is provided between the synthetic resin case body and the joint, and the elastic member is provided and sealed so as to cover the boundary when the joint is attached to the joint insert part. Flow meter . 2. The flowmeter according to claim 1, wherein the joint insert part has a plurality of annular grooves formed on a bottom surface of the annular recess.

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