JPH0774634B2 - Liquid pump - Google Patents

Description

TECHNICAL FIELD The present invention relates to a small, lightweight, and highly reliable liquid pump using a shape memory alloy.

[Prior Art] A device for long-term unmanned operation, such as a space station,
In devices used for artificial satellites and the like, high reliability is required for each device constituting the device. Furthermore, since the space station and artificial satellites are launched into outer space by rockets,
There are severe weight restrictions, and space equipment is required to be highly compact and lightweight.

A liquid pump is mentioned as one of the space equipment, and the liquid pump is used for a cooling water circulation system or the like and is indispensable.

[Problems to be Solved by the Invention] Although an electric liquid pump is generally used as a conventional liquid pump, an electric liquid pump has a large number of mechanically movable parts, supporting parts for the movable parts, electrical contacts, and the like. , There is a problem in terms of reliability. Furthermore, when trying to improve the reliability, there is no choice but to increase the accuracy of parts and the like, which is expensive.

In view of the above circumstances, the present invention is to provide a liquid pump having a simple structure, small size, light weight, and high reliability.

[Means for Solving the Problems] The present invention accommodates a pump actuation body for inducing a volume change in a container body, connects an expandable body made of a shape memory alloy to the pump actuation body, and connects the pump actuation body to the pump actuation body. A return means is provided so as to face the expandable body, and a suction line and a discharge line for sucking and discharging the liquid by the operation of the pump operating body are connected to the container body through a check valve to energize the expandable body. The feature is that it can be shut off.

[Operation] When electricity is applied to the stretchable body, the shape is changed by heating, the shape change causes the pump operating body to change in volume, and liquid is discharged or sucked. When the power supply is stopped, the stretchable body cools and the pump is restored by the return means. The working body is restored, and the liquid is sucked or discharged.

1 for each of the suction line and the discharge line connected to the container body
Since it has a structure in which one check valve is provided, it is sufficient to arrange check valves according to the number of suction lines and discharge lines. The structure is simple and the pump can be constructed in a short time.

[Examples] Examples of the present invention will be described below with reference to the drawings.

In FIG. 1, one end of a bellows 3 is fixed to a bottom surface 2 of a pump casing 1, and the other end of the bellows 3 is fixed to a floating plate 4. A sufficient gap is formed between the outer edge of the floating plate 4 and the inner peripheral surface of the pump casing 1 for the fluid to flow therethrough. Floating plate 4
Is a structure in which the insulating plate 5 is sandwiched between the upper and lower conductive plates 6 and 7,
At least two discharge elastic bodies 8 are provided between the lower conductive plate 7 and the bottom surface 2, and at least two suction elastic bodies 10 are provided between the upper conductive plate 6 and the ceiling surface 9. The lower conductive plate 7 and the discharge elastic body 8 and the upper conductive plate 6 and the suction elastic body 10 are electrically connected to each other, and between the discharge elastic body 8 and the bottom surface 2 and between the suction elastic body 10 and the ceiling surface. Insulating spacers 1 between 9
1,12 are intervening.

The bellows 3 is provided in a liquid-tight manner, and the inside of the bellows 3 communicates with the outside through a through hole 13. A suction line 14 is connected to the pump casing 1 via a check valve 15, and a discharge line 16 is connected to the pump casing 1 via a check valve 17.

The discharge stretchable body 8 and the suction stretchable body 10 are both shape memory alloys that return to the molded shape when the temperature exceeds a predetermined temperature. The discharge stretchable body 8 is connected to a power source 19 via a switch 18 and sucked. Power supply for telescopic body 10 with switch 20
Connect to 19.

Next, the operation will be described.

FIG. 1 shows a state in which the switch 20 is closed and the switch 18 is opened to energize the inhalation elastic body 10.

Since the inhalation stretchable body 10 has an electric resistance, it is heated by emitting Joule heat when energized. When heated and exceeds a predetermined temperature, it expands and contracts as shown in FIG. On the other hand, since the discharge expansion / contraction body 8 is not energized and is cooled by the liquid 21 filling the pump casing 1, there is little change resistance when it is reduced. The expansion of the inhalation elastic body 10 pushes down the floating plate 4 to reduce the volume of the bellows 3. The decrease in the bellows volume is an increase in the remaining volume in the pump casing 1 filled with the liquid, and the liquid 21 is sucked.

Next, the switch 20 is opened and the switch 18 is closed. When the switch 20 is opened, the heating of the inhalation stretchable body 10 is stopped, and conversely, it is cooled by the liquid 21. On the other hand, the discharge expansion / contraction body 8 is heated when the switch 18 is closed to start energization. When the heating / discharging elastic body 8 reaches a predetermined temperature by this heating, the second
Expand as shown. The expansion plate 8 is pushed up by the extension of the discharge elastic body 8 and the bellows 3 increases in volume. Thus, the remaining volume decreases, and the liquid corresponding to the decrease is discharged from the discharge line 16 through the check valve 17.

As described above, the liquid can be sucked and discharged by alternately energizing the suction stretchable body 10 and the discharge stretchable body 8 to alternately perform the extension operation.

3 and 4 show another embodiment, in which the pump casing 1 is a cylinder, and the pump actuating member shown by a bellows is a piston 22, and two pump chambers 23 partitioned by the piston 22 are provided. , 24 are connected to the suction lines 14, 14 and the discharge lines 16, 16 respectively, and the piston 22 is reciprocated by the expansion and contraction of the elastic bodies 25, 25, and the liquid is sucked and discharged by the reciprocating and returning movements of the piston 22, respectively. It is designed to be performed.

FIG. 5 shows still another embodiment, in which the floating plate 4 fixed to one end of the bellows 3 is supported by the open frame 26 via the elastic bodies 8 and 10. In this example, the bellows 4 The pump is operated by using the increase and decrease of the internal volume.

Further, in FIG. 6, a return spring 28 is provided so as to face the expandable body 27.

A coil spring-shaped expandable body 27 is provided concentrically with the bellows 3, and an insulating spacer 29 is interposed between the expandable body 27 and the pump casing 1 to insulate the expandable body 27 and the floating plate 4 from each other. Further, the floating plate 4 and the pump casing 1 are electrically connected via the bellows 3 or the return spring 28.

Then, the expansion body 27 and the pump casing 1 are connected to the power supply 19.

In this embodiment, when the expansion body 27 is energized, the bellows 3 expands and the liquid is discharged, and when the energization is stopped, the expansion body 27 is cooled and the return spring 28 contracts the bellows 3 and the liquid is discharged. Is sucked.

FIG. 7 shows still another embodiment, which is a bellows 3
The coil-shaped stretchable body 27 is provided inside through the insulating plates 30 and 30,
Similarly, the return spring 28 is also provided via insulating spacers 29, 29, and both are electrically insulated from the pump casing 1. Further, the expansion / contraction body 27 and the return spring 28 are electrically connected and connected to the power supply 19.

Therefore, electricity can be supplied through the return spring 28, and the bellows 3 can be expanded and contracted by opening and closing the switch.

In this embodiment, the suction line 14 and the discharge line 16 are also communicated with the inside of the pump casing 1 and the bellows 3, respectively, and the change in the internal volume of the bellows 3 is also utilized to cause the pump action.

Further, the above-mentioned liquid pumps can be provided in parallel, and if a plurality of liquid pumps are provided in parallel, the pump operation will be smooth.

In each of the above examples, the stretchable body was made to expand by heating, but it goes without saying that it may be made to shrink by heating.

[Effects of the Invention] As described above, according to the present invention, not only the shape memory alloy is energized to drive the pump, but also the structure is extremely simple, so that it is lightweight and highly reliable, and the container body is also obtained. Since the suction line and the discharge line connected to each are provided with one check valve respectively, the check valves may be arranged according to the number of the suction lines and the discharge lines. Since the number of valves is small, the structure of the liquid pump is simple and the pump can be manufactured in a short time.

[Brief description of drawings]

FIG. 1 is an explanatory view of a first embodiment of the present invention, FIG. 2 is an explanatory view of the operation before the same, FIGS. 3 and 4 are explanatory views of a second embodiment,
FIG. 5 is an explanatory view of the third embodiment, FIG. 6 is an explanatory view of the fourth embodiment, and FIG. 7 is an explanatory view of the fifth embodiment. 3 is a bellows, 4 is a floating body, 8 is a discharge elastic body, 10 is a suction elastic body, 18 and 20 are switches, 19 is a power source, 22 is a piston, and 27 is an elastic body.

Claims (1)

[Claims] Claim: What is claimed is: 1. A pump actuating body for inducing a volume change is housed in a container body, and an expander made of a shape memory alloy is connected to the pump actuating body, and the pump actuating body is opposed to the expandable body to provide a restoring means. A suction line and a discharge line for sucking and discharging liquid by the operation of a pump actuating body are connected to the container body through a check valve so that the telescopic body can be energized and shut off. Liquid pump to.