JP2001082619A - Check valve holding structure - Google Patents

Abstract

(57) [abstract] (with correction) [PROBLEMS] To provide excellent disassembly workability, easy cleaning of the on-off valve, no need to adjust the clamping pressure on the O-ring during assembly, and a sufficient check effect. Is provided. SOLUTION: A valve seat 151 having a fluid opening at a peripheral position on a concentric circle through an O-ring 136 on an outlet side in a flow direction at a bottom inside a cylindrical hole of a valve case 131.
And a valve receiving sheet 152 having a fluid through hole at the inlet side in the flow direction so that the fluid opening and the fluid through hole do not overlap each other. In the check valve structure that pushes the pushing member 134, a part of the outer peripheral surface of the cylindrical pushing member and a part of the inner wall of the cylindrical hole on the valve case side into which the member is inserted form a receiving step. A stopper portion D is provided so that the pushing depth of the distal end of the small diameter portion of the pushing member into the cylindrical hole of the valve case is always constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to, for example, medical equipment,
The present invention relates to a small-sized microfluid supply device for use in a chemical analysis instrument and the like, and particularly has a non-return valve mechanism for stably controlling supply of a carrier even when liquid / gas and both fluids are alternately used. The present invention relates to a valve mechanism which is a micropump and which can be immediately removed and easily repaired and regularly maintained even if a check valve portion is deteriorated or malfunctions, and an assembly thereof.

[0002]

2. Description of the Related Art Conventionally, a micropump for sending a very small amount of liquid has a number of mechanical principles. For example, a reed valve type or a valveless type is used for a valve mechanism, and a small motor is used for a drive system. 2. Description of the Related Art Small pumps having a diaphragm type mechanism, such as Japanese Patent Application Laid-Open No. 62-291484, have been generally known for some time. This type of micropump is used as a microfluid supply device for medical equipment and chemical analysis equipment, and is used for the constant injection of chemicals and for transporting fluids such as reaction mixture gas. The development of a versatile micropump is underway.

FIG. 9 is an example of a sectional side view of a pump portion of a conventional diaphragm type micropump developed earlier by the present applicant. Although not shown in the drawing, a pump mechanism portion shown in a side cross section is a small motor such as a coreless motor as a driving portion side, and a cam for converting a driving shaft rotation motion of the small motor into a reciprocating piston motion as a pump driving portion side. It comprises a mechanism and a crankshaft for transmitting the reciprocating operation to the diaphragm 132, and further comprises a pump section 130 having suction and discharge valve mechanisms at two locations in the valve case 131 as shown in the figure.

[0004] The operating principle of the pump section 130 is as follows. The pump unit 130 blocks the chamber space provided in the lower part of the valve case 131 using a disk-shaped diaphragm 132 made of an elastic sheet material such as synthetic rubber,
Here, an intermediate storage portion 137 for temporarily storing fluid is formed, and the center portion of the diaphragm 132 is fixed to the tip of a crankshaft that reciprocates in the vertical direction, and elastically deforms to move with amplitude. Is possible and
The outer periphery of the diaphragm circle is held on the valve case 131 side at the outer periphery of the outer diameter of the chamber 133.

[0005] Further, the valve structure following the suction hole 133a and the discharge hole 133b penetrating the upper two places of the chamber 133 is provided with a valve seat 151 having different hole arrangements made of elastic rubber through an O-ring 136. Valve seat 152
Is configured as an on-off valve, and the O-ring 136 is laminated and inserted into a cylindrical hole portion in the valve case 131 so that the O-ring 136 is located on the downstream side in the flow direction of the suction-side and discharge-side valve mechanisms. At 134, the structure is clamped and fixed.

Here, the pushing member 134 has a suction port 140a and a suction port 13 of a suction side nozzle 140A (a broken line portion in FIG. 9).
3a, and a discharge path 135b connecting the discharge port 140b of the discharge side nozzle 140B (also shown by the broken line in FIG. 9) and the discharge hole 133b is provided in a part, and the outer shape is cylindrical. It is.

That is, the pump unit 130 vertically displaces the central plane portion of the diaphragm 132 by the crankshaft to increase or decrease the volume of the intermediate storage unit 137, and utilizes the pressure fluctuation in the chamber 133 generated at that time. This is a pump that sends a fluid in one direction by repeating a series of operations from a suction port 140a to a discharge port 140b.

Here, the structure of a check valve as an on-off valve will be described in detail. The check valve 150 is, as shown in FIGS. 4 and 5, overlaid on a valve seat 151 made of a flat elastic sheet such as a rubber sheet, and an opposing surface on the upstream side in the flow direction of the valve seat 151. And a valve seat 152 made of rubber having the same diameter. The valve seat 151 is provided with a plurality of openings 151a in a concentric peripheral portion, and the valve receiving seat 152 has a small-diameter hole 1
52a are provided, the opening 151a and the hole 152 of both sheets are provided.
They are arranged so that they do not communicate with each other when they overlap.

That is, in the above configuration of the check valve 150, 2
The operating principle of a single sheet valve is as follows.
(Only the suction side in FIG. 9 will be described below for the sake of simplicity.) First, when the diaphragm 132 is displaced downward, that is, when the volume in the chamber 133 is increased, the check valve 150 (open / close valve) is naturally used. ), The inside of the closed chamber is decompressed, and the valve seat 151 on the suction side (in side) is pushed by the fluid sent from the external suction port 140a via the suction passage 135a, When the pressure pushed out from the central hole 152a of the valve receiving seat 152 exceeds the limit of the elastic deformation strength of the valve seat 151, the valve seat 151 elastically deforms in an arc shape. That is, the chamber 133 bends toward the room and expands.

At this time, a gap is formed between the opposed surfaces of the valve seat 151 and the valve receiving seat 152, and the hole 152a and the opening 151a are formed.
Is connected through the gap, the fluid flows from the suction port 140a through the suction passage 135a, through the check valve 150, through the suction hole 133a into the intermediate storage 137 in the chamber 133, and is closed by the diaphragm 132. The interior is filled with fluid.

Next, when the diaphragm 132 is in a stationary state where it is not displaced, or conversely when it is displaced upward,
If the pressure on the suction path 135a side and the intermediate storage section 137 side are equal across the 150, or the pressure on the intermediate storage section 137 side increases due to the upward displacement of the diaphragm 132, the valve seat on the suction side
151 is the valve receiving seat 1 that the elastic deformation returns to the original and faces
In order to completely close the center hole 152a of the 52, the structure is such that the fluid in the intermediate storage part 137 does not flow back to the suction passage 135a side. The combination of this check valve structure functions normally as a pump function.

[0012]

By the way, not only the diaphragm type micro pump as described above, but also the following three use cases can be considered as general micro pump applications. First, there are two cases: a case where only a liquid flows and a case where only a gas flows, and a total of three cases where both liquid / gas fluids are alternately flown. In the past, there was a liquid-specific micropump and a gas-specific micropump, respectively. However, a functionally superior liquid / gas-type micropump has not been developed. There has been no alternative but to use or to use separate liquid dedicated machines and gas dedicated machines by alternately switching paths.

However, if a gas dedicated machine is also used,
In the above-described check valve structure of the sheet-like elastic rubber shown in FIGS. 4 and 5, for example, the liquid is stopped once after flowing, the fluid is switched, and the gas is intermittently flowed thereafter. In the case of a stop, for example, the liquid component remaining in the flow path or inside the pump is not covered by the valve seat 15 of the check valve.
There was a risk that the air would be dried in the gap between the valve seat 1 and the valve receiving sheet 152 and the opposing surfaces of the planar valve seat made of elastic rubber would be physically stuck together.

In this state, an operation failure (failure) in which the on-off valve does not open at the time of restart may occur, and the device may become unusable. Therefore, the pump used in such a situation requires disassembly and repair of the on-off valve part as every time,
For repair and maintenance, it is impossible to disassemble even with a general model, and special tools and specialized skills are required for disassembly and repair and assembly, and further, a replacement for a failed pump is also necessary. Therefore, it takes a great deal of time and cost, and the failure of the on-off valve portion and the maintenance have been serious problems.

Normally, in the operation of the micropump using such an on-off valve, the movement of the valve itself is fairly precise. In particular, in the case of the combination of the above-mentioned on-off valves made of a sheet-like elastic body, it is difficult to incorporate the valve into the valve case. The adjustment has a subtle effect. In other words, the check valve has a structural sealing effect due to surface contact between the valve seat and the valve receiving seat. Further, since the airtightness in the passage is maintained while being sealed by the O-ring, the check valve becomes a packing portion. It is delicately necessary to adjust the allowance (clamp pressure) for the O-ring.

However, in the conventional structure shown in FIG. 9, the valve head 200 is mechanically screwed and fixed to the valve case 131 side via the gasket 220 member. The pushing amount of the pushing member 134, that is, the allowance for the crushing of the opening / closing valve outer peripheral portion (mainly the O-ring) (in other words, the clamping pressure applied to the O-ring) is not constant, and a fine adjustment of the screw tightening torque is required. In addition, a special jig and a measuring instrument are required for the adjustment, and it is not possible to adjust the crushing allowance (clamp pressure) to a fixed amount and to obtain a suitable arrangement. Including such problems, conventionally, maintenance of the on-off valve of the pump has not been easy.

Accordingly, the present invention is excellent in the function of the disassembling operation and the cleaning (maintenance) of the on-off valve even in the problem of malfunction of the on-off valve portion caused by the severe condition of alternately flowing gas / liquid. An object of the present invention is to provide a check valve holding structure that is easy, does not require a clamping pressure adjustment operation for an O-ring of an on-off valve portion during assembly, and can obtain a sufficient check effect. Further, by using the holding structure of the check valve, even if it is disassembled and cleaned every time the pump is used for maintenance of the pump, it is not troublesome, and the opening / closing valve portion of the pump which can satisfactorily transport both liquid and gas fluids. Maintenance inspection becomes easier. It is another object of the present invention to always provide a reliable micropump which can reduce repair and maintenance costs and has no failure.

[0018]

According to the first aspect of the present invention, there is provided a valve receiving sheet which is located at an inlet side of a fluid flow direction and has a hole through which a fluid passes. A valve seat that is located on the outlet side of the fluid flow direction and has an opening through which the fluid passes at a peripheral position on a concentric circle, in a combination in which the arrangement of the holes and the openings does not overlap with each other; Into a cylindrical hole of a valve case having a hole for suction and discharge for passing the fluid through a single O-ring on the outlet side in the flow direction, and further into the valve case, a cylinder having the same diameter. In a check valve structure constituted by pushing a cylindrical pushing member, a part of an outer peripheral surface of a cylindrical pushing member for bringing the valve seat into close contact with the valve receiving seat; A stopper part is provided on a part of the inner wall of the cylindrical hole on the valve case side into which the pushing member is inserted, and a stopper portion serving as a receiving step is provided, and the pushing depth of the tip of the small diameter portion of the pushing member with respect to the inside of the cylinder of the valve case. Is always constant.

In the check valve holding structure described above, for example, by providing a step portion (stopper portion D) shown in FIGS. 1 and 2, the pushing depth of the tip end side of the pushing member 134 with respect to the bottom position E in the valve case is provided. Is always constant regardless of the screw tightening torque of the bolt 202 for fixing the valve head 200. For this reason, if the thickness of the valve seat 151 and the valve receiving seat 152 is always constant, the O-ring 136 receives the clamping pressure from the pushing member 134 side with a certain amount of squeezing margin, and functions as a packing while being elastically deformed appropriately. Thus, the airtightness inside the fluid path can be maintained, and the preferable operation of the on-off valve (check valve) of the combination can be incorporated with good reproducibility.

Further, even if the fluid material is clogged and does not flow due to unfavorable conditions, the pushing member 134 can be relatively easily extracted by loosening the bolt 202 of the pump head 200 and the gasket 220 and disassembling and removing the same. Therefore, disassembly and assembly of the internal on-off valve portion are simplified, the maintenance work efficiency is improved, and the on-off valve portion can be easily repaired without special technical skills.

Here, the valve seat 151, the valve receiving seat 152 and the O-ring 136 are stacked in three stages as shown in FIG. 1 with respect to the suction and discharge directions. When assembling the parts, care must be taken to ensure that the suction and discharge sides are arranged.

Further, the check valve structure according to the first aspect may be more specifically a structure according to the second aspect. That is, the check valve holding structure according to claim 2 is the first step portion formed as the stopper portion D by making at least a part of the bottom side of the valve case cylindrical hole small in diameter. In addition, there is provided a second step portion formed by increasing the diameter of the upper receiving side of the pushing member inserted into the valve case hole. In addition, the steps may be provided on the entire circumference or may be provided partially.

In addition, as an effective means functioning as a step portion, a step portion to be combined is formed into a tapered surface with an inclination at the height position of the step portion, and a stopper step portion is formed at a sliding position of the tapered surface. There is also a way to make it work.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A check valve holding structure according to the present invention will be described below with reference to FIGS.

As shown in the schematic cross-sectional views of FIGS. 1 and 2 and the partial cross-sectional view of the entire pump of FIG. 3, the check valve 150 is used as a check means at, for example, the position of the pump section 130 of the micropump mechanism section 100. The O-ring 136 and the valve seat 151 (elastic seat) constituting the check valve 150 are provided in a cylindrical hole provided in the metal valve case 131.
Are inserted so as to be arranged in the above-described order from the downstream side in the flow direction, and a metal pushing member 134 is inserted and inserted into the hole.

Here, above the pushing member 134,
As in the conventional example, a gasket 220 and a metal valve head 200 are stacked, and the valve head 200 is fixed to the valve case 131 side by bolts 202.

As shown in the schematic sectional view of FIG. 6, the cylindrical two deep holes of the valve case 131 have a circular hole having a portion H having a larger diameter on the opening side and a smaller diameter than the portion H on the opening side. In addition, holes 133a and 133b communicating with the inside of the chamber 133 are formed at the bottom of the deep hole.

Further, as shown in FIG. 7 (external view and cross-sectional view), the two pushing members 134 combined with each other have a cylindrical side surface and a suction passage communicating with the suction / discharge port.
The valve case 131 has an introduction portion G serving as a discharge passage 135b at one location, and has an external shape that is fitted with a step portion having a large or small diameter of the inner diameter portion of the valve case 131. A step portion (stopper portion D) composed of a large diameter portion R is provided.

The non-return valve holding structure is used, for example, in a small-sized microfluid supply device used for medical equipment, chemical analysis equipment, etc. Although there is a pump type, more specifically, a micro pump mechanism 10 as shown in FIG.
At 0, the pump unit 130 is used as a check valve holding structure.

FIG. 8 shows an embodiment in which only the check valve holding part of the present invention is actually incorporated. In the figure, the basic dimensional setting management of the check valve holding structure is as follows. The stopper portion D is a first step portion formed by reducing the diameter of at least a part of the bottom side inside the cylindrical hole of the valve case 131, and the upper receiving portion of the pushing member 134 pushed into the inside of the cylindrical hole. A second step portion formed by increasing the diameter of the side is provided.

With the configuration of the stopper portion D described above, the check valve holding structure can accurately control the height W of a portion W of each cylindrical hole of the valve case 131. In practice, the value of the dimension W of the check valve insertion portion is the value of the valve case 13 shown in FIG.
It is actually controlled by the difference between the dimension T of 1 and the dimension V of the pushing member 134 shown in FIG.

As a result, there is no need for the above-described structure to perform structural adjustments in the assembling operation, such as the management of the height dimension of the pushing member by the tightening torque of the bolts, as well as the confirmation using a dedicated jig or a measuring machine. . Similarly, it is easy to disassemble and repair due to failure, etc., and the crushing allowance (clamp pressure) for the O-ring laminated with the on-off valve
Is inevitably constant, even for non-technical experts. Therefore, the inside airtightness is maintained without fine adjustment, and the holding structure is excellent in maintainability.

Here, it should be added that the valve molded body (for example, the valve seat 151 and the valve receiving sheet 152) in the present invention is made of an elastic rubber (for example, Viton rubber or the like) having excellent chemical resistance. Partly,
Alternatively, all parts may be made of metal.

In the case of a metal check valve structure, irrespective of liquid / fluid, granules of a solvent mixture composed of a hard material of about several microns (for example, ceramic powder, crow beads,
It is also possible to send a fluid containing diamond powder or the like.

[0035]

As described above, according to the check valve structure of the present invention, even in the problem of malfunction of the on-off valve portion caused by the severe condition of alternately flowing gas / liquid, the function of the disassembling operation can be improved. Of a check valve that is excellent in cleaning performance, easy to clean (maintenance) of the open / close valve, does not require a clamping pressure adjustment operation on the O-ring of the open / close valve portion during assembly, and provides a sufficient check effect. can do.

Further, by using the holding structure of the check valve, it is not troublesome to disassemble and clean the pump every time it is used for maintenance of the pump. Maintenance inspection of the on-off valve part becomes easier. In addition, repair and maintenance costs can be reduced, and a reliable micropump free from failure can always be provided.

[Brief description of the drawings]

FIG. 1 is a schematic side sectional view showing a check valve holding structure according to an embodiment of the present invention.

FIG. 2 is a schematic front sectional view showing a check valve holding structure according to an embodiment of the present invention.

FIG. 3 is a schematic partial cross-sectional view showing the entire configuration of a pump using a check valve holding structure according to an embodiment of the present invention.

FIG. 4 is a front external view and a schematic side sectional view illustrating an example of a shape of a valve receiving sheet forming a check valve structure.

FIG. 5 is a front external view and a schematic side sectional view illustrating an example of a shape of a valve seat forming a check valve structure.

FIG. 6 is a schematic side sectional view for explaining a configuration of a stopper portion of the valve case of the present invention.

FIG. 7 is a front external view and a schematic side sectional view illustrating a configuration of a stopper portion of the pushing member of the present invention.

FIG. 8 is a schematic side sectional view showing a height dimension when a valve case and a pushing member, which are components of the check valve holding structure of the present invention, are combined.

FIG. 9 is a schematic front sectional view showing a conventional check valve holding structure.

[Explanation of symbols]

 100 Pump mechanism 120 Cam mechanism 121 Crankshaft 130 Pump section 131 Valve case 132 Diaphragm 133 Chamber 133a, b Suction hole, discharge hole 134 Pushing member 135a, b Suction path, discharge path 136 O-ring 137 Intermediate storage section 140A, B nozzle 140a, b inlet, outlet 151 valve seat 152 valve receiver seat 152a, b hole 200 valve head 202 volt 220 gasket

Continued on the front page F term (reference) 3H051 AA01 BB02 BB03 CC11 CC16 DD01 FF11 3H058 AA14 BB37 CA03 CA23 CA33 CB19 CB25 CD26 EE14 EE20 3H071 AA01 BB01 BB17 CC28 CC32 CC35 DD04 DD12 DD13 DD14 DD52

Claims (2)

[Claims] 1. A valve receiving seat which is located at an inlet side of a fluid flow direction and has a hole through which a fluid passes, and an opening which is located at an outlet side of a fluid flow direction and through which a fluid passes is formed concentrically. With the valve seat having a peripheral position of the, facing the combination of the arrangement of the hole and the opening does not overlap,
These are dropped into a cylindrical hole of a valve case having a suction / discharge hole for transmitting the fluid at the bottom through one O-ring on the outlet side in the flow direction, respectively, and further the same size is inserted into the valve case. In a check valve structure constituted by pushing in a cylindrical pushing member having a diameter, a part of an outer peripheral surface of a cylindrical pushing member for bringing the valve seat into close contact with the valve receiving seat, and the pushing member inside. A part of the inner wall of the cylinder inner hole on the valve case side to be inserted is provided with a stopper part which serves as a receiving step, so that the pushing depth of the tip of the small diameter portion of the pushing member is always constant with respect to the inside of the cylinder of the valve case. A check valve holding structure, characterized in that the check valve is configured to hold a check valve. 2. The check valve structure according to claim 1, wherein the stopper portion is a first step portion formed by reducing at least a part of a bottom side inside the valve case cylindrical hole to a small diameter. And a second step portion formed by increasing the diameter of an upper receiving side of the pushing member pushed into the cylindrical hole.