JPH06147128A - Diaphragm pump - Google Patents

Abstract

PURPOSE:To provide a structure suitable for a depressurization pump using a diaphragm by preventing the unnecessary deformation of the diaphragm even at the time of a pump chamber being depressurized. CONSTITUTION:A diaphragm 8 whose section is of a U-shape and whose projecting shape 8a is faced toward a pump chamber 7 side, makes an annular shape as a whole, and is fitted as if to surround a piston 6 and also that its inner side surfaces may come into contact with at least part of the outer periphery surface of the piston 6 and the inner wall surface of the pump chamber 7 respectively. Accordingly, even if the piston 6 is in the right side piston position or in the left side piston position, unnecessary deformation is not generated at the 8a portion of the diaphragm 8 due to depressurization in the pump chamber 7. Accordingly, the durability of the diaphragm 8 is not damaged, and an efficient depressurization pump can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small-sized pump using a diaphragm.

[0002]

2. Description of the Related Art A conventional small pump of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 62-291484. It has a structure as shown in FIG. In other words, the crankshaft 23 attached to the output shaft 22 of the motor 21 is provided with the drive shaft 24 inclined by a predetermined angle.
A disk-shaped drive body 25 is rotatably attached to the disk 4. Further, a plurality of cup-shaped diaphragm portions 26 each having an opening upward are arranged on the outer peripheral portion of the driving body 25 at substantially equal intervals. 27 is a valve, 28 is another tubular valve, 29 is an inlet, and 30 is an outlet.

In such a small-sized pump, when the motor 21 is driven, the driving body 25 moves the driving shaft 24 in a countersink motion, whereby the root 26a of the diaphragm portion 26 moves up and down. This movement changes, for example, between the state shown at the right end and the state shown at the left end of the diaphragm. By the movement of the diaphragm, the gas in the diaphragm is pressurized by the suction port 29 in the process of shifting to the state at the left end in FIG. Send out. At this time, the bubble 29 is closed. In this way, each diaphragm is pumped by repeating suction and delivery of gas at regular time intervals.

[0004]

When used as an exhaust type pressure pump, the pump having the above structure can generate high pressure with extremely high efficiency. However, when used as a vacuum pump for suction, the following problems occur. FIG. 4 is a cross-sectional view showing a part of a decompression type pump using the above-mentioned principle. In such a pump, the gas is sucked into the suction port 31 by driving the driving body 25 and moving the diaphragm 26 as described above.
The gas is further sucked into the diaphragm by opening the valve 21, pressurizes the gas in the diaphragm, and opens the valve 28 to discharge the gas. In this way, a vacuum pump can be obtained by the same principle as that shown in FIG. However, in this decompression type pump, since the wall surface 26a of the diaphragm 26 is made of an elastic material such as rubber and has a small thickness, when the inside 26b of the diaphragm 26 is decompressed, the wall surface 26a is deformed inward as shown in the drawing. However, the pump efficiency is significantly lowered, and while the pumping action is continued, the problem of durability arises by repeating the deformation of the state shown in FIG. 4 and the original state. Therefore, the pump using the cup-shaped diaphragm as shown in FIG. 3 has a practical drawback for use as a vacuum type.

An object of the present invention is to provide a pump using a diaphragm and having a structure suitable as a decompression type pump.

[0006]

A pump of the present invention comprises a plurality of pump chambers formed at equal intervals on the circumference, and pistons respectively held so as to be reciprocable in the respective pump chambers. A piston drive mechanism for reciprocating each piston at a predetermined time interval (shifting the phase) is provided. The piston drive mechanism is a crank base rotated about an output shaft, and the crank base. It consists of a drive shaft that is tilted and supported on the drive shaft, and a plate-shaped drive body that is rotatably attached to the drive shaft. Each piston is connected to the periphery of this drive body. Are connected at the peripheral portion of the driving body at a predetermined interval as described above. In the pump of the present invention, the inner wall surface of the pump chamber and the outer peripheral surface of the piston are connected to each other by a diaphragm made of a thin elastic material to hold the piston so that the piston can reciprocate. The shape does not cause

The desirable shape of the diaphragm holding the piston by connecting the inner wall surface of the pump chamber and the outer wall surface of the piston is such that the cross section thereof is U-shaped and the bent portion faces the pump chamber. It is conceivable that a part of the outer surface of each end is joined to the inner wall surface of the pump chamber and the outer wall surface of the piston.

The pump of the present invention performs the pumping action by moving the driving body in the same manner as in the conventional example, but there is no problem even if the pressure in the room is reduced, and it is suitable for a pressure reducing pump. The pump of the present invention can also be used as a pressure pump.

[0009]

Embodiments of the diaphragm pump of the present invention will now be described with reference to the drawings.

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a partially enlarged sectional view thereof, wherein 1 is a driving motor, 2 is a motor output shaft, and 3 is a crank base fixed to the output shaft 2. Four
Is a drive shaft inclined with respect to the crank base 3, 5 is a disk-shaped drive member rotatably attached to the drive shaft 5, and 6 are arranged in the peripheral portion of the drive member 5 at equal intervals. The plurality of pistons are located in each of the plurality of pump chambers 7 arranged along the circumference and can reciprocate. 8 is a diaphragm for connecting and holding the pump chamber 7 and the piston 6 so that the pump chamber 7 is kept airtight, and 9 is a check valve 11
An intake port 10 communicating with the pump chamber 7 via the exhaust port 10 is an exhaust port communicating with the pump chamber 7 via the check valve 15. Here, the diaphragm 8 has a U-shaped cross-section as shown in FIG. 1 or FIG. 2, and its convex shape 8a is directed to the pump chamber side. It is mounted so as to surround 6 and its inner surface is in contact with the outer peripheral surface of the piston 6 and the inner wall surface of the pump chamber 7 at least partially. Therefore, regardless of whether the piston 6 is located on the left side piston position in FIG. 1 or on the right side piston position (piston position in FIG. 2), unnecessary deformation does not occur in the portion 8a of the diaphragm 8 due to pressure reduction in the pump chamber.

In this embodiment, similarly to the pump shown in FIG. 3, the crank base 3 is rotated by the rotation of the motor 1 and the pistons are alternately reciprocated by the driving shaft 4 by the disc rotating motion of the driving body 5 with a constant time interval. do. By the reciprocating motion of this piston, air is taken in through the intake port 8 and acts as a decompression pump. Here, as described above, even when the pump chamber is depressurized, the diaphragm is not deformed, and the problem that the efficiency of the pump is lowered does not occur.

In FIG. 1, 11, 12, 14, and 15 are all check valves, and 13 is a passage connecting one pump chamber to another pump chamber. Further, in this embodiment, the diaphragm 8 is integrally formed with the piston 6, the plurality of pistons 6 are integrally connected by the diaphragm 8, and the peripheral portion 8b of the diaphragm is formed with the main body 16 forming the pump chamber 7 and the crank base 3, The drive mechanism portion including the drive shaft 4 and the drive body 5 is fixed by being sandwiched by a case 17 which houses the drive mechanism portion. However, the diaphragm may have another shape, and its fixing may be performed by other means such as adhesion.

[0013]

According to the pump of the present invention, the shape of the diaphragm for reciprocatingly holding the reciprocating piston in the pump chamber hardly deforms other than the deformation for the normal movement of the piston. The durability is not impaired, and since there is no deformation of the pump chamber during pressure reduction, an efficient pressure reduction pump can be constructed.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a diaphragm portion of the above embodiment.

FIG. 3 is a sectional view of a conventional diaphragm pump.

FIG. 4 is a sectional view when the principle of the pump shown in FIG. 3 is applied to a decompression pump.

[Explanation of symbols]

 1 Motor 2 Output Shaft 3 Crank Base 4 Drive Shaft 5 Driver 6 Piston 7 Pump Chamber 8 Diaphragm 9 Intake Port 10 Exhaust Port

Claims (2)

[Claims] 1. A plurality of pump chambers arranged at regular intervals on the circumference, pistons respectively held reciprocally with respect to the respective pump chambers, and one end of each piston is fixed. A plate-shaped drive body, and a drive shaft having one end rotatably attached to the drive body and the other end inclined and attached to a crank that rotates about an output shaft,
An intake port communicating with the pump chamber via a check valve,
A diaphragm that has an exhaust port communicating with the pump chamber via a check valve, connects the inner wall of the pump chamber and the outer surface of the piston, and holds the piston while keeping the pump chamber airtight. And a diaphragm pump which prevents unnecessary deformation of the diaphragm even when the pressure of the pump chamber is reduced by the piston. 2. A diaphragm pump according to claim 1, wherein said diaphragm has a U-shaped cross section and its convex shape faces the inside of the pump chamber.