JPH0355833Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a bellows type air pump reducer using a metal bellows.

BACKGROUND ART A bellows is a cylindrical body with a smooth chevron-shaped continuous cross-section wall.A bellows-type air pump using a metal bellows expands and contracts the bellows repeatedly in the axial direction, and pumps out external air when the bellows is stretched. Since the air is inhaled and the bellows is contracted, the inhaled air is discharged to perform a pumping action. I have an idea.

Problems that the invention attempts to solve Utility Model Application No. 1983-103678 (Utility Model Application No. 1983-10278)
The idea is to increase the number of ridges of a metal bellows with wall thickness in a continuous cross-section in the shape of a smooth ridge, to form a small amount of expansion and contraction per ridge, and to create a structure within the bellows that has a slight play with the inner diameter of the bellows. Provided with a reducer that fits into the bellows and reduces the volume of space within the bellows,
The bellows is formed so that the amount of expansion and contraction of the bellows is large compared to the space volume within the bellows, so that air can be discharged with a high discharge pressure. This actual request from 1986
In the bellows compressor of No. 103678 (Japanese Utility Model Publications No. 63-10278), there is also an extra space inside the chevron of the bellows that is not affected by the expansion and contraction of the bellows. Therefore, there is a problem that the discharge pressure cannot be increased.

Means for Solving the Problems This invention consists of a metal bellows having a smooth chevron-shaped continuous cross-section wall, which is slightly loosely fitted into the small diameter part of the inner circumference of the bellows, and has a suction valve inside. In a bellows-type air pump reducer equipped with a discharge valve, a ring is formed with an outer diameter slightly larger than the large diameter part of the inner periphery of the bellows, and an inner diameter the same as the small diameter part of the inner periphery of the bellows. The thickness of the ring is such that when the bellows is compressed, both sides of the ring come into contact with the chevron-shaped inner surface, and the side surface shape of the outer peripheral edge of the ring has the same curvature as the periphery of the large diameter portion. form, and
The bellows is characterized in that a space reducer made of an elastic body and having a cut in a part of the ring in the radial direction is pressed into contact with a large diameter part of the inner peripheral part of the bellows.

Function In the device configured in this way, the outer peripheral edge of the space reducer, which is a ring, comes into pressure contact with the large diameter part of the inner peripheral part of the bellows, and when the bellows is compressed,
Both surfaces of the space reducer come into pressure contact with the inner surface of the angular shape of the bellows, and the space volume inside the angular shape that is not affected by the expansion and contraction of the bellows is reduced.

Embodiments This invention will be explained in detail based on illustrated embodiments.

FIG. 1 is a diagram showing an embodiment of this invention. In FIG. 1, 1 is a bellows, 2 is a reducer, 3 is a space reducer, 4 is a bellows lid, 5 is a mounting plate, and 6 is a filter. The bellows 1 is made of a non-rust metal, for example, a copper alloy such as bronze, or a non-rust steel such as stainless steel, and is formed with a large number of threads. In other words, by keeping the amount of expansion and contraction to less than 1 to 1/2 of the allowable amount of expansion and contraction for each smooth mountain-shaped continuous cross-section wall,
The length is formed sufficiently long in the axial direction. Bellows 1
is formed so that the space reducer 3 is inserted and locked in the large diameter part of the inner peripheral part.

As shown in FIGS. 2 and 3, the space reducer 3 is formed of an elastic material into a ring shape that remains elastic even after molding. Further, the space reducer 3 is formed with a cut 7 in a part of its radial direction so that the ring diameter can be expanded and contracted. Furthermore, the side shape of the outer peripheral edge 8 of the ring is changed to a bellows 1.
It is formed to have the same curvature as the area around the large diameter part of the inner periphery.
Further, the ring thickness is formed in accordance with the amount of expansion and contraction of the bellows 1. That is, when the bellows 1 is contracted, both sides of the ring of the space reducer 3 are in contact with the smooth chevron-shaped inner surface of the bellows 1, and when the bellows 1 is expanded, both sides of the ring of the space reducer 3 are in contact with the smooth inner surface of the bellows 1. It is formed so as to face the chevron inner surface with an allowance. In other words, the thickness is approximately 1/2 between the inner sides of the chevron. In addition, the outer diameter of the space reducer 3 is formed to be slightly larger than the maximum diameter of the smooth chevron-shaped inner surface of the bellows 1, so that the outer peripheral edge 8 of the space reducer 3 has a slight mutual surface pressure, and the bellows 1 Formed in contact with a smooth chevron-shaped inner surface. In addition, the inner diameter of the ring of the space reducer 3 is formed to be the same as the diameter of the valley on the smooth chevron-shaped inner surface of the bellows 1, that is, the small diameter part of the inner circumference, so that the inner circumferential edge of the ring protrudes inward from the valley of the chevron. Form it so that it does not. The space reducer 3 is inserted into the angular shape of the bellows by shifting the cut 7 to reduce the ring diameter, and is secured to the inside of the angular shape of the bellows 1 by the elastic force of the space reducer 3 itself. Further, the space reducer 3 may be inserted into all the smooth chevrons of the bellows 1, or a plurality of space reducers 3 may be inserted depending on the discharge pressure of the air pump. The bellows 1 has one open end sealed with a disc-shaped bellows lid 4, and a lid boss 9 is provided at the center of the disc of the bellows lid 4, and the lid boss 9 has a bottomed screw that opens on the outside of the lid boss 9. A hole 10 is provided. Further, the bellows 1 is provided with a flange joint-shaped mounting plate 5 provided with a flange extending in the radial direction at the other open end. The reducer 2 is for reducing the space volume inside the bellows 1 due to expansion and contraction of the bellows 1, and has a flange 11 having the same outer diameter as the flange outer diameter of the mounting plate 5, and a flange 11 that is connected to the flange 11 and has a diameter smaller than the inner diameter of the bellows 1. It is formed by providing a solid rod-like block 12 having a slightly smaller outer diameter.
The block 12 is provided with spaced apart and parallel suction holes 13 and discharge holes 14 which open at the end face of the flange 11 and pass through the block 12. The suction hole 13 is provided with a suction valve 15, and the discharge hole 14 is provided with a discharge valve 16. In this case, the axial positional relationship between the bellows 1 and the reducer 2 is such that the flange of the mounting plate 5 provided on the bellows 1 overlaps the back surface of the flange 11 of the reducer 2, and the bellows cover 4 of the bellows 1 and the block 12 overlap. The bellows 1 is formed so that the distance from the end face corresponds to the amount of expansion and contraction of the bellows 1. That is, when the bellows 1 is compressed, the inner surface of the bellows lid 4 is formed to be close to the end surface of the block 12 of the reducer 2, leaving a very small distance.
The bellows 1 locks the space reducer 3 on the inside of the smooth chevron, and with the reducer 2 inserted therein, the bellows 1 is removably fixed to the front lid 18 of the outer box 17 formed into a cylindrical shape. , through holes are provided at positions corresponding to the suction holes 13 and discharge holes 14 of the reducer 2, and the suction holes 13 and the discharge holes 14 are opened to the outside air. The filter 6 is located on the outer surface of the front lid 18 of the outer box 17, and is located between the suction hole 13 and the discharge hole 14.
A filter cover 19 is provided in the area surrounding the front lid 18 and fixed to the front lid 18. In this case, a discharge nozzle 20 is provided in the discharge hole 14 so as to extend to the outside of the filter cover 19, and the discharge nozzle 20 is provided so as to extend through the filter cover 19. It is formed so that outside air is drawn in through a gap between the nozzle 20 and the protrusion. Also bellows 1
A tensile force and a compressive force are applied alternately with a constant stroke in the axial direction of the bellows 1 to the lid boss 9 provided on the bellows lid 4 through a bottomed screw hole 10 that opens on the outer surface of the bellows lid 4. Connect the prime mover.

Next, to explain the operation, when this bellows type air pump regulator is not in operation, both the suction valve 15 and the discharge valve 16 are closed, and when it is in operation, the bellows 1 is compressed and the suction valve 15 is closed. The discharge valve 16 is opened. Air within the bellows 1 passes through the discharge hole 14 and is discharged from the discharge nozzle 20. During intake, the bellows 1 is extended, and external air passes through the filter 6 and the intake valve 15, which is in an open state.
be introduced within. The discharge valve 16 is closed, and the introduced air flows through the bellows lid 4 and the block 1 of the reducer 2.
2 and the gap space between the smooth chevron-shaped side surface of the bellows 1 and the ring surface of the space reducer 3. When the bellows 1 is in the compressed state, the bellows lid 4 and the block 1 of the reducer 2
2 and the gap space between the smooth chevron-shaped side surface of the bellows 1 and the ring surface of the space reducer 3 become "zero", and the external air introduced into this part is discharged. FIG. 4 is a discharge amount-hydraulic head diagram illustrating the function of the space reducer 3 from the viewpoint of effectiveness. The vertical axis shows the discharge amount in liters per minute, and the horizontal axis shows the discharge pressure in meters. A line with a steep slope indicates a bellows type air pump without a space reducer 3, and a line with a gentle slope indicates one without a space reducer 3. Both have the same structure in other respects including dimensions. As shown in the figure, the space reducer 3
The discharge pressure is limited to 2 meters water column in the case without the space reducer 3, but it was able to increase to 4 meters water column in the case with the space reducer 3.

Effects In this invention, the space reducer is provided inside the smooth chevron of the bellows, so
It becomes possible to reduce the unnecessary space inside the chevron. Since the external air introduced into the inner side of the chevron during the suction stroke of the air pump is also completely discharged during the compression stroke, there is no surplus space that is not related to the pump action. Therefore, according to this invention, the effect of increasing the discharge pressure can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway sectional view showing an embodiment of this invention. Figure 2 is an enlarged sectional view of the bellows and space reducer, Figure 3 is a side view and front view of the space reducer,
FIG. 4 is a comparison diagram of discharge amount vs. discharge pressure. 1...Bellows, 2...Register, 3...
Space reducer, 4... Bellows lid, 5...
...Mounting plate, 6...Filter, 7...Cut,
8...Outer periphery.

Claims (1)

[Scope of utility model registration request] For bellows-type air pumps that fit slightly loosely into the small diameter part of the inner periphery of a metal bellows that has a smooth chevron-shaped continuous cross-sectional wall thickness, and are equipped with a suction valve and a discharge valve inside. In the reducer, the outer diameter is slightly larger than the large diameter part of the inner circumference of the bellows, and the inner diameter is formed to be the same as the small diameter part of the inner circumference of the bellows to form a ring, and the thickness of the ring is set such that when the bellows is compressed, , both surfaces of the ring are formed so as to be in contact with the chevron-shaped inner surface, and the side surface shape of the outer peripheral edge of the ring is formed to have the same curvature as the periphery of the large diameter part, and a part of the ring in the radial direction 1. A reducer for a bellows type air pump, characterized in that a space reducer made of an elastic body and having a slit is pressed into contact with a large diameter portion of an inner peripheral portion of the bellows.