JP2006329096A - Check valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a check valve used in a multistage ejector and having high durability for withstanding use for many hours. <P>SOLUTION: This check valve is composed of a metallic base 17 constituting a bulkhead between a suction port of the multistage ejector and a pressure reducing chamber and provided with a communicating hole 17a communicating the suction port with the pressure reducing chamber, a rubber-made valve member 21 having a thick-walled part 21a provided in a central part and thin-walled parts on its both sides, a pin member 22 passing through the overlapped thick-walled part and thin-walled parts of the valve member and provided with large diameter 22b for preventing coming-off in an end part on one side, and a ring member 23 attached to an end part on the other side of the pin member. The valve member 21 is provided on a pressure reducing chamber side for the base 17 and at a position where the thin-walled parts 21c cover the communicating hole 17a of the base. The base 17 and the thick-walled part 21a of the valve member 21 are nipped by a large diameter part 22b of the pin member 22 and the ring member 23. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a check valve for a multistage ejector used as a vacuum pressure generation source.

There is a multi-stage ejector used as a vacuum pressure generator.
For example, the ejector shown in FIG. 5 includes a metal body 1 and a pressurized gas chamber 10, a first decompression chamber 11, a second decompression chamber 12, a third decompression chamber 13, and an exhaust chamber 14 through partition walls. Are adjacent to each other. The first nozzle 3 is provided in the partition between the pressurized gas chamber 10 and the first decompression chamber 11, the second nozzle 4 is provided in the partition between the first decompression chamber 11 and the second decompression chamber 12, and the second nozzle 4. The third nozzle 5 is provided in the partition between the third decompression chamber 12 and the third decompression chamber 13, and the fourth nozzle 6 is provided in series on the same axis in the partition between the third decompression chamber 13 and the exhaust chamber 14. ing. The inner diameters of these first to fourth nozzles are sequentially increased from the first to the fourth nozzles.

Further, a gas supply port 7 that communicates with the pressurized gas chamber 10, a suction port 8 that communicates with the first to third decompression chambers 11 to 13, and an exhaust port 9 that communicates with the exhaust chamber are formed in the base 2. .
Such a main body 1 and the base body 2 are coupled by a coupling means such as a bolt via a seal member 15.
Further, a check valve 16 is provided between the second decompression chamber 12 and the third decompression chamber 13 and the suction port 8 so as to be sandwiched between the main body 1 and the base 2.

As shown in FIGS. 6 and 7, the check valve 16 includes a metal substrate 17 and a rubber valve member 18.
A plurality of communication holes 17 a for communicating the second and third decompression chambers 12, 13 and the suction port 8 and a mounting hole 17 b for the valve member 18 are passed through the substrate 17.
The valve member 18 includes a seat portion 18a and two pin-like convex portions 18b formed integrally with the seat portion 18a at the center thereof, and an annular concave portion 18c is formed at the base of the convex portion 18b. Forming. Further, the outer diameter of the convex portion 18 b is set larger than the inner diameter of the mounting hole 17 b of the substrate 17.

Therefore, the valve member 18 can be fixed to the substrate 17 by passing the convex portion 18b through the mounting hole 17b and matching the concave portion 18c formed at the base with the mounting hole 17b.
In FIG. 6, three valve members 18 are provided on one substrate 17 to form three check valves 16a, 16b, 16c. However, the check valves 16a, 16b are attached to the valve members. The position is indicated by a two-dot line. The check valve 16 a is attached to the second decompression chamber 12, and the other two check valves 16 b and 16 c are attached to the third decompression chamber 13. Here, when it is not necessary to distinguish the individual check valves 16a, 16b, and 16c, the check valves 16 will be described.

  In the multistage ejector apparatus configured as described above, when gas is supplied from the supply port 7, the gas passes through the first nozzle 3 from the pressurized gas chamber 10 and is ejected toward the second nozzle 4. When the air ejected from the first nozzle 3 flows into the second nozzle 4, the air in the first decompression chamber is drawn in, and these gases are ejected from the second nozzle 4 toward the third nozzle 5. . When the gas ejected from the second nozzle 4 flows into the third nozzle 5, the air in the second decompression chamber 12 is drawn in. Similarly, when the gas flows from the third nozzle 5 to the fourth nozzle 6, the air in the third decompression chamber 13 is drawn.

As described above, when pressurized air is supplied from the supply port 7, the air in each of the decompression chambers 11 to 13 is drawn and discharged from the exhaust port 9 to the outside. As a result, each decompression chamber is decompressed, but the degree of vacuum decreases sequentially from the first decompression chamber 11.
When each of the decompression chambers 11 to 13 is decompressed and the degree of vacuum is higher than that of the suction port 8, the valve pair 18 of the check valve 16 is opened as shown by a two-dot chain line in FIG. Air flows into the second decompression chamber 12 and the third decompression chamber 13. As a result, when the degree of vacuum on the suction port 8 side is increased and the degree of vacuum on the suction port 8 side is higher than that on the decompression chamber side, the check valve 16 is closed.

Specifically, at first, all the check valves 16a, 16b, and 16c are in an open state, and air flows from the suction port 8 to the decompression chamber side. When the degree of vacuum on the suction port 8 side increases with the discharge of air and the degree of vacuum becomes higher than that of the third decompression chamber 13, the check valves 16b and 16c of the third decompression chamber 13 are closed, and the suction port 8 and The flow path between the third decompression chamber 13 is blocked. By sucking air through the first decompression chamber 11 and the second decompression chamber 12, the vacuum degree of the suction port 8 is further increased. When the vacuum degree of the second decompression chamber 12 is exceeded, the second decompression chamber 12 The check valve 16 a is also closed, and the air on the suction port 8 side is sucked and discharged only through the first decompression chamber 11. Thus, a high degree of vacuum can be realized more quickly by depressurizing a plurality of decompression chambers in order.
A vacuum chamber can be connected to the suction port 8 configured as described above via a vacuum pipe so that the inside of the chamber can be evacuated or a workpiece can be adsorbed.
Registered Utility Model No. 3022143

  In the case of generating a vacuum with the ejector device as described above, the check valve 16 has a degree of vacuum in the second decompression chamber 12 and the third decompression chamber 13 provided with the degree of vacuum in the suction port 8. Open and close depending on the height. In the opened state of the check valve 16, the seat portion 18 a of the valve member 18 is separated from the substrate 17 as indicated by a two-dot chain line in FIG. 7. In this state, when air flows into the decompression chambers 12 and 13 from the suction port 8, both ends of the sheet portion 18a are pulled toward the decompression chamber by the air flow in the direction of the arrow. On the other hand, the convex portion 18 b provided on the sheet portion 18 a is fixed to the substrate 17.

Therefore, the seat portion 18a of the valve member 18 is pulled toward the decompression chamber side while the convex portion 18b is fixed, and a tension acts on the seat portion 18a, the convex portion 18b, and the connecting portion P1.
Further, both ends of the sheet portion 18a are vibrated by the air current, and the connection portion P1 is rubbed by the mounting hole 17b of the substrate 17 due to the vibration.
As described above, when the sheet portion 18a is repeatedly pulled in the direction away from the substrate or rubbed by the metal substrate 17, the connection portion P1 may be broken.

In addition, when this apparatus is used for vacuum suction of a workpiece, the workpiece can be sucked to the suction port 8 side. However, when removing the sucked workpiece, the degree of vacuum in the decompression chamber and the suction port 8 is reduced. And must be at normal pressure. If the supply of pressurized air from the supply port 7 is stopped and left as it is, the internal vacuum will be reduced due to leakage, but in order to detach the workpiece more quickly, a positive pressure is applied from the path not shown to the suction port 8. May supply air. In particular, when a sticky material such as rubber is used for the adsorption surface that adsorbs the workpiece, the workpiece may be adhered by its adhesive force and may not be detached even if the internal pressure becomes normal pressure. .
In that case, if positive pressure air is supplied into the apparatus from the supply port 8 side, the air opens the check valve 16 and flows into the decompression chambers 12 and 13, and the first to third decompression chambers 11 to 11. As the vacuum of 13 is broken, the suction port 8 is also at a normal pressure or a positive pressure, and the adsorbed workpiece can be easily detached.

As described above, when the second and third decompression chambers 11 and 12 and the suction port 8 are decompressed and the check valve 16 is in the closed state, when the positive pressure is introduced to the suction port 8, the check valve 16 suddenly increases. Will open. At this time, a greater force acts on the seat portion 18a of the valve member 18 of the check valve 16 than when the ejector device is used as a vacuum generation source. Therefore, the sheet part 18a may be torn off from the convex part 18b.
As described above, if a crack occurs between the sheet portion 18a and the convex portion 18b, or if the sheet portion 18a is torn off from the convex portion 18b and removed, the decompression chambers 12 and 13 are connected to the suction port 8. It becomes impossible to regulate the air flow. For this reason, the degree of vacuum in each decompression chamber cannot be quickly increased, and as a result, the degree of vacuum in the suction port 8 cannot be increased.

Accordingly, the valve member 18 must be replaced with a new one before the valve member 18 is damaged. However, in the check valve 16 shown in FIGS. 6 and 7, the durability of the valve member 18 is low, so the valve member 18 or the check valve 16 must be frequently replaced, and the cost of the apparatus increases accordingly. It will be.
An object of the present invention is to provide a check valve for use in a multistage ejector, which has high durability to withstand long-time use.

  According to a first aspect of the present invention, there are provided a plurality of decompression chambers and a plurality of straight tubular nozzles arranged coaxially along a fluid flow direction from the intake port to the exhaust port, and a suction provided at a position off the axis of the nozzle A check valve for restricting the flow of fluid from a decompression chamber to a suction port in a multistage ejector having a port, which forms a partition wall between the suction port and the decompression chamber and communicates the suction port and the decompression chamber A metal substrate provided with a communication hole to be connected, a rubber valve member having a thick portion provided at the center and thin portions on both sides thereof, and the thick portion of the valve member and the substrate are overlapped and penetrated And a pin member having a large-diameter portion for retaining at one end, and a ring member attached to the other end of the pin member, and the valve member on the decompression chamber side with respect to the substrate, And the said thin part is a communicating hole of a board | substrate Provided with a position covering, characterized in that configured by sandwiching a thick portion of the substrate and the valve member by the large-diameter portion and said ring member of said pin member.

  The second invention is based on the first invention and is characterized in that both ends of the thin portions on both sides of the thick portion of the valve member are thicker than the other portions of the thin portion.

According to the first and second inventions, the durability of the valve member is high even with repeated opening and closing, and the durability of the check valve is improved.
According to the second invention, even when the tip of the valve member collides with the nozzle in the decompression chamber when the check valve is opened, it is difficult to be damaged. As a result, the durability of the check valve is further improved.

1 to 4 show an embodiment of the check valve 20 of the present invention.
The check valve 20 is used in the multistage ejector shown in FIG. 5 that functions as a vacuum generation source, like the conventional check valve 16 described above. And it replaces with the check valve 16 shown in FIG. Therefore, FIG. 5 is used also for the following description. That is, the check valve 20 is provided between the second decompression chamber 12 and the third decompression chamber 13 and the suction port 8. And since the effect | action of the check valve 20 in the multistage ejector shown in FIG. 5 is the same as the check valve 17 of a prior art example, the description is abbreviate | omitted here.

The check valve 20 shown in FIG. 1 includes a metal substrate 17, a rubber valve pair 21, and a pin member 22.
The substrate 17 is the same as the conventional substrate 17 shown in FIG. 6, and includes a plurality of communication holes 17 a for communicating the second decompression chamber 12 and the third decompression chamber 13 with the suction port 8, and a pair of valve members 21. And an attachment hole 17b.
And the check valve 20 is comprised by attaching the valve member 18 to this board | substrate 17 so that the said communicating hole 17a may be covered.

  In FIG. 1, three check members 20a, 20b, and 20c are formed by providing three valve members 21 on one substrate 17, but the check valves 20a and 20b are attached to the valve members. The position is indicated by a two-dot line. The check valve 20 a is attached to the second decompression chamber 12, and the other two check valves 20 b and 20 c are attached to the third decompression chamber 13. Here, when it is not necessary to distinguish the individual check valves 20a, 20b, and 20c, the check valves 20 will be described.

As shown in FIG. 2, the valve member 21 of the check valve 20 has a substantially quadrangular sheet shape, and includes a strip-shaped thick portion 21a having a thickness larger than that of other portions at the center. A pair of through holes 21b and 21b corresponding to the mounting holes 17b of the substrate 17 are formed in the thick portion 21a.
Moreover, the both sides of the said thick part 21a are made into the thin part 21c, and the front-end | tip part 21d is made thicker than the other part of the thin part 21c.

As shown in FIG. 3, the pin member 22 includes a large-diameter portion 22b at one end of the shaft portion 22a, and an annular recess 22c at the other end.
Such a valve member 21 is overlaid so as to cover the communication hole 17a of the substrate 17, and the through hole 21b of the valve member 21 and the mounting hole 17b of the substrate 17 are made to coincide with each other, and the shaft portion 22a of the pin member 22 is placed there. To penetrate. Then, a C-ring as a ring member is fitted into the annular recess 22c of the shaft portion 22a protruding from the substrate 17, and the large-diameter portion 22b and the C-ring 23 sandwich the substrate 17 and the valve member 21 to couple them together.

  In the check valve 20 thus configured, the outer diameter of the shaft portion of the pin member 22 is the same as or slightly the same as the inner periphery of the through hole 21b so that air leakage does not occur from the inner periphery of the mounting hole 17b and the through hole 21b. It is large so that there is no gap between the pin member 22 and the through hole 21b. Further, the distance between the annular recess 22c and the large diameter portion 22b is set to be equal to or less than the total thickness of the thick portion 21a and the substrate 17, and the large diameter portion 22b and the C ring 23 are used to When sandwiched, the thick portion 21a is elastically deformed to close the gap.

The amount of deformation of the thick portion 21a is determined by the clamping force of the pin member 22 and the C ring 23 on the thick portion 21a, but can be adjusted by the position of the annular recess 22c in the shaft portion 22a.
For example, when using bolts and nuts instead of using the pin member 22 and the C-ring 23, it takes time to connect the two members so that the tightening force is constant. In addition, in the configuration in which the C ring 23 is fitted in the annular recess 22c, it is easy to make the tightening force constant if the position of the annular recess 22c is determined.

  When the check valve 20 is attached to the ejector shown in FIG. 5 and the second decompression chamber 12 or the third decompression chamber 13 has a higher degree of vacuum than the suction port 8, the check valve 20 shown in FIG. Thus, the valve member 21 is separated from the substrate 17 and is in the open state. Thus, even if the thin part 21c bends on both sides of the thick part 21a of the valve member 21, there is a portion that is pulled in the opposite direction like the connection part P1 (see FIG. 7) of the valve member 18 of the conventional example. Absent. Further, since the valve member 21 has no portion inserted into the mounting hole 17b of the substrate 17, there is no friction portion with the metal.

Therefore, with this check valve 20, even if opening and closing is repeated, the thin portion 21c is not easily broken.
Further, since the thickness of the tip 21d of the thin portion 21c is increased, the valve member 21 is not greatly damaged even if the tip of the valve member 21 is greatly opened and collides with the outer wall of the nozzle in the decompression chamber.
Conventionally, since the valve member 18 having the thin sheet portion 18a is used as a whole, the distal end of the valve member 18 may be broken by repeatedly colliding with the outer wall of the nozzle. In order to prevent the tip of the valve member 18 from hitting the outer wall of the nozzle, the distance between the check valve 16 and the nozzle must be increased, and the decompression chamber is enlarged. If the decompression chamber is large, it is difficult to achieve a high degree of vacuum in a short time. If the tip 21d is made thicker as in this embodiment, the valve member 21 is unlikely to be damaged even if it collides with the outer wall of the nozzle, so there is no need to enlarge the decompression chamber.

  The check valve 20 of the present invention and the check valve 16 of the conventional example were subjected to a durability test that repeatedly opened and closed, and it was confirmed that the durability was improved by the present invention. Under the same conditions, the number of times of opening / closing until the crack is generated in the valve member 21 of the check valve 20 of the present invention is compared with the number of times of opening / closing until the seat portion 18 of the check valve 16 is cracked and removed from the protrusion 18b. Was 10 times or more.

1 is a plan view of an embodiment of the present invention. It is a perspective view of the valve member of an embodiment. It is a perspective view of the pin member of an embodiment. It is the IV-IV sectional view taken on the line of FIG. It is sectional drawing of a multistage ejector. It is a top view of the check valve of a prior art example. It is the VII-VII sectional view taken on the line of FIG.

Explanation of symbols

17 Substrate 17a Communication hole 20 Check valve 20a Check valve 20b Check valve 20c Check valve 21 Valve member 21a Thick part 21b Through hole 21c Thin part 21d Tip part 22 Pin member 22b Large diameter part 22c Annular recess 23 C ring

Claims (2)

  A multi-stage including a plurality of decompression chambers and a plurality of straight tubular nozzles arranged coaxially along the fluid flow direction from the intake port to the exhaust port, and a suction port provided at a position off the axis of the nozzle A check valve for restricting the flow of fluid from a decompression chamber to a suction port in an ejector, which forms a partition wall between the suction port and the decompression chamber and has a communication hole for communicating the suction port and the decompression chamber A rubber valve member having a metal substrate, a thick portion provided in the central portion and thin portions on both sides thereof, and the thick portion of the valve member and the substrate are overlapped to penetrate one end portion. And a ring member attached to the other end of the pin member, and the valve member is on the decompression chamber side with respect to the substrate, and the thin portion is Set in a position that covers the communication hole of the board. Rutotomoni, the pin large diameter portion and the ring member and by a check valve for multi-stage ejector configured by sandwiching a thick portion of the substrate and the valve member of the member   2. The check valve for a multistage ejector according to claim 1, wherein both ends of the thin portion on both sides of the thick portion of the valve member are thicker than other portions of the thin portion.

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