Valve and fluid control apparatus
A valve includes a lower valve housing, a diaphragm, and an upper valve housing. A top surface of a piezoelectric pump is bonded to a bottom surface of the lower valve housing. A circular hole portion is provided in a central portion of a region of the diaphragm that opposes a projecting portion of the lower valve housing. The diaphragm is bonded to the upper valve housing and the lower valve housing, and a divided interior of a valve housing configures a first lower valve chamber, a second lower valve chamber, a first upper valve chamber, and a second upper valve chamber. A groove is located in a wall portion of the upper valve housing that opposes the diaphragm in the first upper valve chamber.
1. A valve comprising:
a valve housing including a first opening portion and a second opening portion; and
a diaphragm including a hole portion and configured to define in the valve housing a first valve chamber configured to communicate with the first opening portion and a second valve chamber configured to communicate with the second opening portion; wherein
a portion of the diaphragm surrounding the hole portion is in contact with a portion of the valve housing such that the portion of the valve housing covers the hole portion; and
a flow channel formation portion is provided in at least a portion of a wall portion of the second valve chamber, a portion of the flow channel formation portion being arranged to oppose a portion of the hole portion, the flow channel formation portion defining a flow channel connecting the first valve chamber and the second valve chamber when the portion of the diaphragm surrounding the hole portion makes contact with the wall portion.
2. The valve according to claim 1 , wherein the diaphragm is anchored to the valve housing so that the portion of the diaphragm surrounding the hole portion makes contact with or separates from the valve housing due to a difference between a pressure in the first valve chamber and a pressure in the second valve chamber.
3. The valve according to claim 1 , wherein
the flow channel formation portion includes a groove; and
the groove extends from a region of the wall portion that opposes the hole portion in the diaphragm to a region of the wall portion that opposes a portion of the diaphragm spaced away from the hole portion.
4. The valve according to claim 1 , wherein
the flow channel formation portion includes a projection; and
the projection extends from a region of the wall portion that opposes the hole portion in the diaphragm to a region of the wall portion that opposes a portion of the diaphragm spaced away from the hole portion.
5. The valve according to claim 1 , wherein a width of the flow channel formation portion is smaller than a diameter of the hole portion.
6. The valve according to claim 1 , wherein
the valve housing is provided with a projecting portion that projects toward the diaphragm side in the first valve chamber; and
the portion of the diaphragm surrounding the hole portion makes contact with the projecting portion.
7. The valve according to claim 6 , wherein the first valve chamber, the second valve chamber, and the projecting portion each have cylindrical or substantially cylindrical shapes when viewed from above in a direction perpendicular or substantially perpendicular to the diaphragm.
8. The valve according to claim 6 , further comprising:
a first adhesive sheet; and
a second adhesive sheet; wherein
the valve housing includes a first valve housing in which the first opening portion is provided and a second valve housing in which the second opening portion is provided;
the first valve housing and the diaphragm are bonded to each other by the first adhesive sheet and the diaphragm and the second valve housing are bonded to each other by the second adhesive sheet;
a first through-hole is provided in a region of the first adhesive sheet that faces the first valve chamber and a second through-hole is provided in a region of the second adhesive sheet that faces the second valve chamber;
an outer circumference of the first through-hole is greater than an outer circumference of the projecting portion and smaller than an outer circumference of the first valve chamber; and
an outer circumference of the second through-hole is greater than the outer circumference of the projecting portion and smaller than an outer circumference of the second valve chamber.
9. The valve according to claim 6 , further comprising:
a first adhesive sheet; and
a second adhesive sheet; wherein
the valve housing includes a first valve housing in which the first opening portion is provided and a second valve housing in which the second opening portion is provided;
the first valve housing and the diaphragm are bonded to each other by the first adhesive sheet and the diaphragm and the second valve housing are bonded to each other by the second adhesive sheet;
a first through-hole is provided in a region of the first adhesive sheet that faces the first valve chamber and a second through-hole is provided in a region of the second adhesive sheet that faces the second valve chamber;
an outer circumference of the first through-hole is greater than an outer circumference of the projecting portion and equal to an outer circumference of the first valve chamber; and
an outer circumference of the second through-hole is greater than the outer circumference of the projecting portion and equal to an outer circumference of the second valve chamber.
10. The valve according to claim 1 , wherein the flow channel formation portion has a shape that is one of an elongated, narrowed shape, a cross shape, a polygon shape, and an oval shape.
11. The valve according to claim 1 , wherein the flow channel formation portion includes a projection or a groove.
12. A fluid control apparatus comprising:
a pump provided with an ejection hole; and
the valve according to claim 1 ; wherein
the first opening portion of the valve is connected to the ejection hole of the pump; and
the second opening portion of the valve is connected to a fluid holding portion that holds a fluid.
13. The fluid control apparatus according to claim 12 , wherein the fluid is one of a gas and a liquid.
14. The fluid control apparatus according to claim 12 , wherein the diaphragm is anchored to the valve housing so that the portion of the diaphragm surrounding the hole portion makes contact with or separates from the valve housing due to a difference between a pressure in the first valve chamber and a pressure in the second valve chamber.
15. The fluid control apparatus according to claim 12 , wherein
the flow channel formation portion includes a groove; and
the groove extends from a region of the wall portion that opposes the hole portion in the diaphragm to a region of the wall portion that opposes a portion of the diaphragm spaced away from the hole portion.
16. The fluid control apparatus according to claim 12 , wherein
the flow channel formation portion includes a projection; and
the projection extends from a region of the wall portion that opposes the hole portion in the diaphragm to a region of the wall portion that opposes a portion of the diaphragm spaced away from the hole portion.
17. The fluid control apparatus according to claim 12 , wherein a width of the flow channel formation portion is smaller than a diameter of the hole portion.
18. The fluid control apparatus according to claim 12 , wherein
the valve housing is provided with a projecting portion that projects toward the diaphragm side in the first valve chamber; and
the portion of the diaphragm surrounding the hole portion makes contact with the projecting portion.
19. The fluid control apparatus according to claim 18 , wherein the first valve chamber, the second valve chamber, and the projecting portion each have cylindrical or substantially cylindrical shapes when viewed from above in a direction perpendicular or substantially perpendicular to the diaphragm.
20. The fluid control apparatus according to claim 18 , further comprising:
a first adhesive sheet; and
a second adhesive sheet; wherein
the valve housing includes a first valve housing in which the first opening portion is provided and a second valve housing in which the second opening portion is provided;
the first valve housing and the diaphragm are bonded to each other by the first adhesive sheet and the diaphragm and the second valve housing are bonded to each other by the second adhesive sheet;
a first through-hole is provided in a region of the first adhesive sheet that faces the first valve chamber and a second through-hole is provided in a region of the second adhesive sheet that faces the second valve chamber;
an outer circumference of the first through-hole is greater than an outer circumference of the projecting portion and smaller than an outer circumference of the first valve chamber; and
an outer circumference of the second through-hole is greater than the outer circumference of the projecting portion and smaller than an outer circumference of the second valve chamber.