JP3680187B2 - Small pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a small pump which is small and can obtain high efficiency.
[0002]
[Prior art]
Conventionally, a small pump operated by a small DC motor driven by a dry cell or the like is used as a pump used in a low-pressure compressor such as a personal blood pressure monitor or a compressor used in an air brush.
[0003]
As a conventional example of this small pump, there is a small pump developed by the present applicant. This is described in Japanese Patent Laid-Open Nos. 62-291484, 63-004383, and 63-066762, and has the structure shown in FIG.
[0004]
In FIG. 2, 1 is a small DC motor, 2 is an output shaft of the motor 1, 3 is a case attached to the surface of the motor 1 on the output shaft side, 4 is a collar fixed to the output shaft 2, and 5 is an output shaft. The drive shaft 6 is fixed to the collar 4 so as to be inclined at a predetermined angle with respect to 2 and its tip is located at the center axis of the output shaft 2. Two drive shafts 6 are formed in a disk shape and provided at intervals of 180 ° A drive body having a hole 7, 8 is a cylindrical support portion extending downward and integrally formed at the center of the drive body 6, and 9 is a steel for reducing friction between the drive shaft 5 and the drive body 6. Ball, 10 is another case screwed into case 3, 11 is a diaphragm main body formed on a disk made of an elastic material such as soft and thin rubber, 12 is an equal angle of 90 °, 120 °, 180 °, etc. Extends downward from the surface of the main body at an interval (180 ° in the figure) and forms a single piece Two bell-shaped pump chambers, 13 is a drive unit, 14 is a head formed at the tip of the drive unit 13 through a thin neck, and 15 is opposite to the pump chamber 12 from the center of the surface of the main body. A cylindrical first valve body extending upward and integrally formed, 16 is a substrate attached to the case 10, 17 is an intake hole formed at a location where the pump chamber 12 of the substrate is located, and 18 is A valve chamber portion formed upward in the center of the substrate 16, 19 is an exhaust hole formed at the tip of the valve chamber portion 18, 20 is a second valve body, and 21 is a valve common to each pump chamber 12. It is a groove | channel which connects the chamber part 18 respectively.
[0005]
Next, the operation of the small pump configured as described above will be described. When the motor 1 is energized and the output shaft 2 rotates, the drive shaft 5 also rotates. As a result, the drive body 6 rotates, and the drive unit 13 of each pump chamber 12 vibrates in the vertical direction with a phase difference of 180 °. . When the volume of the pump chamber is periodically changed by the piston movement of the pump chamber 12 and the drive unit 13 moves downward to increase the volume, the pump chamber 12 is depressurized and the first valve body 15 is In close contact with the chamber portion 18, the second valve body 20 is opened and air flows from the intake hole. Next, when the drive unit 13 moves upward to reduce the volume, the pump chamber 12 is increased in pressure and the second valve body 20 closes in close contact with the substrate 16, whereas the first valve body 15 The portion closing the groove 21 of the pump chamber 12 is opened, and the air in the pump chamber 12 is discharged from the exhaust hole 19 through the common valve chamber portion 18.
[0006]
Each pump chamber performs pumping once with one rotation of the driving body, but the pumping operation is performed twice with a constant phase difference as a whole, and the pulsation of the air flow is reduced and the operation efficiency is good. . In addition, a pump chamber is formed integrally with the motor, and a plurality of pump chambers are arranged around a common chamber at the center, and a driving body is arranged between the motor and the pump chamber. The device and motor are integrated to make the shape very small.
[0007]
[Problems to be solved by the invention]
The conventional small pump described above has a first valve body made of an elastic body formed in a cylindrical shape as shown in FIG. 3, and a substrate on which a valve chamber portion is formed by the action of the first valve body. The fluid such as air is pushed out through the 16 groove portions 21. In order to reduce the resistance due to the valve body at that time, the first valve body 15 has a position corresponding to an intermediate position between the two groove portions 21 provided in the substrate 16 constituting the valve chamber portion 18 as shown in FIG. In some cases, slits 15a are formed. By providing the slit 15a in this way, the valve body 15 can be easily opened when the fluid is pushed out through each groove, thereby reducing the pressure loss.
[0008]
However, when the parts are transported before assembling the small pump based on each part, the valve body 15 is often deformed in transporting the valve body, which is one of the parts. For example, the cylindrical valve body may be crushed, or conversely, the cylindrical valve body may be deformed in the opening direction. Such deformation returns to its original state at the time of assembly due to its elastic force, but the deformed state may remain slightly, and a stable pumping action may not be performed by this slight deformation. As described above, when the valve body is provided with the slit, the tendency becomes strong.
[0009]
The present invention has been made in order to eliminate the above-described drawbacks, and it is an object of the present invention to provide a small pump capable of performing a stable pumping action even when the valve body is deformed as described above.
[0010]
[Means for Solving the Problems]
The small pump of the present invention is a pump using a diaphragm having a plurality of pump chambers as described above, and the inner diameter of the valve chamber portion in the vicinity of the tip portion of the first valve body is the inner diameter of the other portion. Thus, even if the valve body is slightly deformed, the valve body is surely brought into close contact with the inner wall surface of the valve chamber so that a good pumping action is performed.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the small pump of the present invention will be described with reference to the drawings.
[0012]
FIG. 1 is a diagram showing a configuration of a small pump according to the present invention. In the figure, 1 is a small DC motor, 2 is an output shaft of the motor 1, 3 is a case attached to the surface of the motor 1 on the output shaft side, 4 Is a collar fixed to the output shaft 2, 5 is a drive shaft fixed to the collar 4 so as to be inclined with respect to the output shaft 2 by a predetermined angle and its tip is located on the central axis of the output shaft 2, 6 Is a disk-shaped drive body having holes 7 formed at equal intervals, 8 is a cylindrical support portion extending downward and integrally formed at the center of the drive body 6, and 9 is driven with the drive shaft 5. Steel balls for reducing friction between the bodies 6, 10 is another case screwed into the case 3, 11 is a diaphragm body made of an elastic material, and 12 extends downward from the surface of the body at intervals of 180 °, for example. And two pump chambers in the shape of a single bell, 13 A drive unit 14 is a head formed at the tip of the drive unit 13 through a thin neck, and 15 is a first unit integrally formed extending from the center of the surface of the main body to the upper side opposite to the pump chamber 12. A valve body, 16 is a substrate attached to the case 11, and 17 is an intake hole formed at a location of the substrate 16 where the pump chamber 12 is located. The number of pump chambers is not limited to two but may be a plurality of pump chambers arranged at equal angular intervals. For example, three pump chambers at intervals of 120 ° and four pump chambers at intervals of 90 ° may be formed.
[0013]
The small pump of the present invention has the same basic configuration as that of the conventional example shown in FIG. 2, and the pump action is basically the same.
[0014]
However, as shown in FIG. 1, the small pump of the present invention is different from the conventional example shown in FIG. 2 in the shape of the valve chamber portion leading to the discharge port formed in the substrate 16. That is, as shown in FIG. 1, the common valve chamber portion 32 formed inside the exhaust portion 31 that extends in a cylindrical shape above the substrate 16 has the largest inner diameter at the lower portion thereof, and extends upward. Accordingly, the inner diameter is gradually reduced.
[0015]
In the present invention, since the valve chamber portion 32 is configured as described above, the tip portion 15b of the first valve body 15 made of an elastic material and having a cylindrical shape has an inner wall surface (diameter of the valve chamber portion 32). Is held in such a manner that it can be pushed and bent inward by the smaller portion. As a result, even if the first valve body is deformed during transportation and bent inward, it is restored to the substantially original shape of the cylinder by the restoring force due to elasticity, and is further tapered. Pushed inward by the inner wall surface of the valve chamber portion 32, the first valve body 15 is brought into close contact with the inner wall surface of the valve chamber portion 32. Thereby, even if the valve body 15 is deformed during transportation as described above, a sufficiently good pumping action can be performed.
[0016]
The shape of the valve chamber 32 shown in FIG. 1 has a tapered shape in which the diameter gradually decreases from the relatively lower portion (the portion indicated by reference symbol A in the drawing) toward the upper portion (the portion indicated by reference character B in the drawing). However, the present invention is not limited to this.
[0017]
For example, the taper-shaped range may be further increased or decreased, and the valve chamber section may have a curved shape instead of a linear shape as illustrated.
[0018]
In any case, when the first valve body is inserted into the valve chamber portion, the first valve body in a certain range near the tip 15b of the first valve body, for example, in a certain range near C in FIG. Even when the first valve body deformed by making the diameter smaller than the diameter of the valve body is used, the close contact between the valve body and the inner surface of the valve chamber portion is ensured, and a good valve action is possible. In this figure, the first valve body 15 is provided with a slit 15a, but the present invention can also be applied to a pump using the first valve body without a slit. Thus, when it has the slit 15a, it is preferable to make it taper shape from D to C at least.
[0019]
In the illustrated embodiment, a pump comprising two pump chambers having an angular interval of 180 ° between the pump chambers has been described. However, the present invention can be applied to three or more pump chambers and a plurality of pumps. I can do it.
[0020]
【The invention's effect】
The small pump of the present invention is characterized by the shape of the valve chamber, and has the effect that a good pumping action is performed even if the first valve body is deformed during transportation.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a small pump of the present invention. FIG. 2 is a diagram showing a configuration of a conventional small pump. FIG. 3 is a diagram showing a shape of a valve body.
12 Pump chamber 15 First valve body 16 Substrate 21 Exhaust section 22 Valve chamber section

Claims (1)

A diaphragm portion having a plurality of pump chambers installed in the case, a driving body that sequentially moves up and down each pump chamber of the diaphragm portion, and a substrate attached to the case so as to cover the pump chamber of the diaphragm portion And an exhaust hole provided in the center of the substrate, an intake hole formed at a position corresponding to each pump chamber of the diaphragm around the exhaust hole of the substrate, and an exhaust hole of the substrate. The valve chamber portion, a substantially cylindrical first valve body provided in the valve chamber portion, and a second valve body provided in the intake hole of the substrate, and the valve chamber portion A small pump characterized in that when the first valve body is attached, the diameter in the vicinity of the tip portion of the first valve body is smaller than that of the other portions.

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