JPH07139471A - Gas pressure driven micro pump - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce pressure shock, to make low flow rate and delivery speed accurate, and to facilitate adjustment of delivery speed. [Structure] A flow path means (10) having a first port (11), a second port (12) and a flow-through space (13) communicating therewith; along the flow-through space (13) Arrayed diaphragms (2
1a to 21e); Diaphragm supporting means (2) having a plurality of working gas spaces (22a to 22e) facing the back surface of each diaphragm.
0); a plurality of reciprocating motion means for individually applying gas pressure vibration to each of the working gas spaces (22a to 22e); and a reciprocating motion means in which the top dead center changes in the arrangement direction. Drive means for reciprocating with a phase difference;

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro pump for feeding and driving a fluid at a low flow velocity (flow rate / time), and more particularly,
The present invention relates to a low flow pump that has less pressure shock due to pumping.

[0002]

2. Description of the Related Art For example, continuous monitoring is preferable when monitoring the living blood supplied to the dialysis machine or the blood returned to the living body from the dialysis machine during artificial dialysis. In this case, the blood is separated from the dialysis flow path. It is necessary to flow it and supply it to the monitor device. Since blood to which reagents and the like have been added by the monitor device is discarded, it is preferable to continuously supply blood to the monitor device so that continuous monitoring can be performed and at a flow rate as low as possible. In addition, it is preferable that the pressure vibration, particularly the impact pressure, be as small as possible in order to prevent thrombus and to improve the accuracy of measurement and inspection. In addition, continuous injection, low flow rate and low pressure vibration may be required when continuously injecting a small amount of drug or auxiliary liquid into the living body.

To meet this type of demand, hitherto, a resilient tube was pressurized with a roller mounted at the tip of a rotor (three or four radially extending rotating arms). Roller pumps have been proposed. Further, a plurality of push plates are arranged in the direction in which the elastic tube extends, and each push plate is ejected and driven by a cam plate which is rotationally driven by an electric motor. The peristaltic movement is caused and the tu
There has been proposed a finger pump that delivers the fluid in the tube by squeezing the tube.

[0004]

Both the roller pump and the finger pump described above push the elastic tube and suck the driven fluid by the restoring force of the tube. Therefore, in principle, There is a limit to low flow rate. To make the flow rate low, the smaller the tube diameter, the dimensional error of the tube,
Variations in flow rate due to mounting errors of rollers, push plates, etc. become large, making flow rate adjustment difficult. Further, the delivery flow rate decreases and the flow rate fluctuation easily occurs as the tube elasticity decreases. Further, the pressure shock is absorbed to some extent by the elasticity of the tube, but this shock absorbing capacity is reduced.

A first object of the present invention is to reduce pressure shock, a second object is to make a low flow rate and a delivery amount accurate, and a third object is to facilitate adjustment of the delivery amount. To aim.

[0006]

A gas pressure driven micropump according to the present invention has a first port (11), a second port (12) and a flow space (13) communicating with each other. Channel means (1
0); respectively, from the first port (11) to the first port (11) along the flow-through space (13), the surface of which is exposed to the flow-through space (13) and can be bulged / retracted from the space. A plurality of diaphragms (21a to 21e) arranged in the direction of two ports (12);
Diaphragm support means (20) having a plurality of working gas spaces (22a to 22e) arranged on the opposite side of the flow space (13) with respect to (21a to 21e) and facing the back surface of each diaphragm; A plurality of reciprocating means (Fig. 1: 60, 73a to 7) for individually applying gas pressure oscillation to each of the gas spaces (22a to 22e).
3e / Fig. 4: 55 in 53a to 53e / Fig. 5: 60, 75a to 75e, 76a to 76e);
Each of the reciprocating means is connected to the first port (1
Driving means for reciprocating with a phase difference in a relationship in which the top dead center gives a high pressure peak to the working gas space (22a-22e) in the direction from the one close to 1) to the second port (12) (Figure
1: 72a to 72e, 90a to 90e, 100 / Fig. 4: 72a to 72e, 90a to 90e, 100 /
5:96, 97); In addition, in order to facilitate understanding, the symbols of the corresponding elements of the examples shown in the drawings and described later are entered in parentheses for reference.

[0007]

The driving means includes the first and second reciprocating means respectively.
A high-pressure peak is applied to the working gas space (22a to 22e) in the direction from the one close to the port (11) to the one close to the second port (12). When you drive
Each pressure of the working gas space (22a-22e) oscillates high and low, and the high pressure peak is close to the first port (11)
It moves sequentially from (22a) to the working gas space (22b) near the second port (12). Corresponding to the pressure oscillation of the working gas space (22a to 22e), the diaphragm (21a to 21e) bulges with respect to the flow space (13) at high pressure and retracts from the flow space (13) at low pressure. , The bulge sequentially moves from the diaphragm (21a) near the first port (11) to the diaphragm (21b) near the second port (12). As a result, the fluid in the flow-through space (13) will flow through the first port.
It is squeezed out from (11) toward the second port (12).

There is a working gas space (22a to 22e) between the reciprocating body and the diaphragm, and the gas (air) in the space is compressible (contracts when the pressure increases and expands when the pressure decreases).
Therefore, even if the reciprocating body reciprocates in a pulsed (two-position) manner, the pressure applied to the diaphragm is smoothed into a sine wave (sine wave) by the contraction / expansion of the gas, and the operation is performed. The bulging / retracting movement of the diaphragms (21a to 21e) with respect to the gas space (22a to 22e) is smooth and soft, and the fluid delivered by this causes a pressure vibration or pressure shock in a frequency region higher than the reciprocating vibration of the diaphragm. Virtually never occurs. The fluid delivered will be closer to a static flow.

Since the gas in the working gas space (22a-22e) is compressible, no sharp pressure is applied to the diaphragm, and the probability that the diaphragm will be broken by the pressure shock is low. Therefore, the diaphragm may be thin and small in size.
The thinner and smaller the diaphragm, the lower the flow rate.
Nevertheless, the flow rate can be adjusted by adjusting the repetitive cycle of the vibration of the reciprocating body in addition to the fact that the flow rate does not substantially fluctuate. Therefore, it is possible to realize a micropump having a required low flow rate and an adjustable flow rate. The diaphragm is
Since the shape change with time like the tube of the roller pump does not occur, the delivery amount does not substantially decrease with time.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0011]

FIG. 1 shows a pump mechanism of a first embodiment of the present invention. The flow channel member 10 is generally rectangular and has a rectangular groove-shaped fluid flow channel 13 formed on the inner surface of the bottom wall.
The first and second ports 12 communicate with the left end portion and the right end portion of the driven fluid passage 13. The bottom surface of the fluid flow path 13 has a groove 14 with a circular edge and a spherical bottom surface for receiving a spherical top portion when the diaphragm bulges, at a position where a diaphragm, which will be described later, faces each other. A roughly rectangular silicon plate 20 is inserted inside the flow path member 10 and is pressure-bonded to the bottom surface of the flow path member 10 via heat-sealable adhesive films 41 and 42. The silicon plate 20 includes five working gas chambers 22a to 22a at positions facing the fluid flow path 13.
22e is opened by etching, and the openings of these gas chambers 22a to 22e facing the fluid flow path 13 are closed by diaphragms 21a to 21e, respectively. In this embodiment, the silicon plate 20 having the gas chambers 22a-22e and the diaphragms 21a-21e is manufactured as follows.

(A) SiO ₂ layers are formed on the front and back surfaces of a silicon plate having a thickness of about 250 μm (one silicon plate for forming a plurality of silicon plates 20; hereinafter simply referred to as a silicon plate). At this time, the silicon plate has a base of about 1200 ° C. in order to have a slack in the diaphragm to be generated later.
And King, 5000 Å thickness of about SiO ₂ layer (the layer of surface, the lower layer of the diaphragm after) to form a; (b) the SiO ₂ layer on the surface of the silicon plate, NiCrSi of about 2000Å thick by a sputtering technique Form the layers. A portion of this NiCrSi layer will later become the upper layer of the diaphragm. Until the formation of this NiCrSi layer is completed, the silicon plate is maintained at about 1200 ° C. in order to allow the diaphragm to have slack; (c) After the silicon plate has cooled to about room temperature, NiCrSi
A resist film is formed on the layer, and the resist film is exposed and etched to leave the resist film only in the diaphragm (21a to 21e) region; (d) By dry etching (reverse sputtering), the NiCrSi layer other than directly under the resist film is formed. To remove. The NiCrSi layer remaining in this manner and the SiO ₂ layer immediately below it are the diaphragm (two-layer structure). These two layers generate relatively large internal stress (compressive stress in the SiO ₂ layer and tensile stress in the NiCrSi layer because of different thermal expansion coefficients) in an attempt to shrink due to a decrease in temperature. Since it is integrated with the base portion of the silicon plate, it does not cause slack; A resist film for forming is formed; (f) The working gas chambers 22a to 22a are formed on the rear surface of the silicon plate facing the NiCrSi layer 22 by exposure and etching.
By forming an opening for 22e and further etching (hydrofluoric acid treatment), SiO _{2 in the} opening (the back surface of the silicon plate 20) is formed.
Layers are also removed, then removed the table, the back surface of the resist film; (g) the opening of the back surface of the SiO ₂ layer is etched, the SiO ₂ layer surface holes or working gas chamber 22a reaches the (lower layer of the diaphragm) Open ~ 22e. When the SiO ₂ layer of the diaphragm is etched, the diaphragm (Si
Since the constraint of (O ₂ layer + NiCrSi layer) is removed, the compressive stress acting on the SiO ₂ layer is released and the diaphragm is bent; (h) The SiO ₂ layers on the front and back surfaces are removed, and the silicon plate is formed into a rectangular Cut and separate each unit (plurality). The separated one is the silicon plate 20 shown in FIG. Referring again to FIG. 1, the upper relay plate 30 is pressure-bonded to the lower surface of the silicon plate 20 via the heat-fusible adhesive film 43. Gas passages 31a to 31e communicating with the working gas chambers 22a to 22e are opened in the upper relay plate 30, and fine grooves 32 passing through the centers of the gas passages 31a to 31e are engraved on the lower surface of the relay plate 30. There is. The fine groove 32 has a narrow width and a shallow depth that is not blocked by an O-ring and is scratched by a pin tip.

As described above, inside the flow path member 10,
The silicon plate 20 and the upper relay plate 30 are inserted in this order, and these three members 10, 20 and 30 are integrally fixed.

The lower case 80 is of a generally box-like shape having an open upper side, and a bottom wall has a hole for allowing the plungers 73a to 73e to move up and down. Solenoid 7 based on these holes
0a to 70e are stored in the lower case 80. The solenoid 70a is composed of a core 71a, an electric coil 72a that circulates the core 71a, and a plunger 73a. The small diameter portion of the plunger 73a penetrates the core 71a.
A disk-shaped pad head is provided on the outer side of a and is integrated with the plunger 73a together with the small diameter portion. Other solenoid 70b
.About.70e have the same structure and dimensions as 70a. A thin film 60 made of silicon rubber is placed on the above-mentioned contact heads of the solenoids 70a to 70e, and the lower relay plate 50 is placed on the thin film 60. The lower relay plate 50 has a solenoid 7
Gas chambers 51a to 51e that allow the thin film 60 to be pushed up by the head of 0b to 70e, and gas passages for connecting these gas chambers 51a to 51e to the gas passages 31a to 31e,
In addition, O-ring housing holes for substantially airtightly coupling the gas passages 31a to 31e of the upper relay plate 30 and the gas passages 31a to 31e of the lower relay plate 50 are formed. An O-ring is fitted in the O-ring storage hole.

As described above, inside the lower case 80,
The five solenoids 70a to 70e, the thin film 60, and the lower relay plate 50 are housed in this order from the bottom. By pushing the flow path member 10 incorporating the silicon plate 20 and the relay plate 30 as described above into the upper opening of the lower case 80, the upper relay plate 30 moves the lower relay plate 50 through the O-ring. Press down to push membrane 60 and solenoids 70a-7
0e is pushed on the inner bottom surface of the lower case 80. In this pressed state, the claws 8 of the lower case 80 are inserted into the claw notch grooves 15 and 16 of the flow path member 10.
1, 82 enter and the flow path member 10 and the lower case 80 are integrated.

The lower case 80 is connected to the flow path member 10
When pulling up with a slightly strong force, the claws 81 and 82 will move into the claw groove 1.
The flow path member 10 is disengaged from the lower case 80 by being disengaged from the parts 5 and 16. In this way, the both are made detachable so as to make them disposable (disposable) to prevent infection when used as a medical infusion pump.

When the flow path member 10 is mounted on the lower case 80, the upper relay plate 30 is pushed further downward after the upper relay plate 30 is brought into close contact with the O-ring, so that the working gas chambers 22a to 22e are moved from the gas chambers 51a to 51e. Or the diaphragms 21a to 21e remain expanded, or even if the diaphragms 21a to 21e do not expand at that time, the pressure in the space increases due to the subsequent temperature increase. The diaphragms 21a-21e swell. When the plunger 73a is driven upward in such a bulged state, the pressure in the space may further increase and the diaphragm 21a may burst. If the diaphragm 73a does not burst, the bulging / retracting stroke of the diaphragm 21a with respect to the reciprocating movement of the plunger 73a is small, and the pumping ability is significantly reduced. In order to prevent such a phenomenon, fine grooves 32 are carved in the upper relay plate 30. When the flow path member 10 is attached to the lower case 80, the upper relay plate 30 is pushed further downward after the upper relay plate 30 is brought into close contact with the O-ring, so that the working gas chambers 22a to 22a are moved from the gas chambers 51a to 51e.
When the air pressure in the space reaching to 22e becomes higher than the atmospheric pressure, the air in the space passes through the gap between the fine groove 32, the upper relay plate 30 and the lower relay plate 50, the flow path member 10 and the lower case 80. -Escape outside the room. When the pressure in the space rises or falls due to temperature rise or fall after the passage member 10 is attached to the lower case 80, a flow is generated between the space and the outside air through a similar path. Therefore, when not in use, the diaphragms 21a to 21e always maintain a predetermined flexible shape (FIG. 1).

The diaphragms 21a to 21e are the bases of the silicon plate when the above-mentioned SiO ₂ layer is formed in the unused state.
Due to the king, it has a shape with a bend at room temperature as shown in FIG. When the pressure of the gas chambers 22a to 22e rises in this state, the diaphragm bulges in the direction of entering the fluid flow path 13, but the top part thereof enters the groove 14 and the top part does not hit the bottom surface of the fluid flow path 13. Absent. If the bulging top portion of the diaphragm hits the flat bottom surface of the fluid flow path 13, the top portion of the diaphragm is deformed from a spherical shape to a flat shape, and bending strain is repeatedly applied to shorten the diaphragm life and reduce the pumping efficiency (with respect to the vibration of the diaphragm). Although the driven fluid delivery amount is low, the diaphragm 14 does not contact the bottom surface due to the presence of the groove 14, and further, the diaphragm bulges to the top dead center in a spherical shape, so that such an adverse effect does not occur.

FIG. 2 shows the solenoids 70a to 70e described above.
To the electric coils 72a to 72e of the diaphragm 21a to
21e shows an electric circuit for energizing to vibrate 21e. The pulse generator 94 of the energization control device 100 has an electric pulse A having a cycle corresponding to the resistance value of the potentiometer 95.
To occur. Please refer to FIG. 3 for the electric signals generated by the circuit elements of the energization control device 100. 5
The advance counter 93 counts this electric pulse A. The counter 93 counts up from the initial state (count value 0) to count values 1, 2, 3, and 4 each time one pulse A arrives, and automatically returns to count value 0 when the count value becomes 5, and Further, it is a circulation counter which counts up to 1, 2, ..., And count data showing count values 0 to 5 is given to the decoder 92. Decorator 92
Keeps its output signal B0 at a high level H and the other output signals B1 to B4 at a low level L while the count data is 0. When the count data is 1 to 4, the output signals B1 to B4 are set to H, and the other output signals are set to L.
To maintain. Among the output signals B0 to B4, those adjacent to each other in the H generation order are given to the augments 91a to 91e, and their outputs become the signals C1 to C5 shown in FIG.
These signals C1 to C5 are applied to the solenoid drivers 90a to 90e, respectively. Solenoid driver 9
0a to 90e are signals H1 to C5, respectively.
During that time, each of the electric coils 72a to 72e is energized.

For example, when the electric coil 72a is energized (C1 = H) at the time t1 shown in FIG. 3, the plunger 73a is activated.
Is sucked by the core 71a, and the contact head at the upper end of the plunger 73a pushes up the thin film 60 inward of the gas chamber 51a. As a result, the pressure of the working gas chamber 22a rises through the gas passage 31a, and the diaphragm 21a has a bulging shape that projects from the flexible shape (FIG. 1) to the inside of the driven fluid flow path 13. That is, the diaphragm 21a is the fluid flow path 13
Swell to. As a result, the driven fluid on the upper side of the diaphragm 21a is partially pushed in the direction of the first port 11 and partially pushed in the direction of the diaphragm 21b.

At the next time t2, the diaphragm 21a is still bulging, but the electric coil 72b is energized and the diaphragm 21b is moved to the fluid flow path 13 in the same manner as described above.
Swell to. At this time, most of the driven fluid on the upper side of the diaphragm 21b is pushed toward the diaphragm 21c because the diaphragm 21a is bulging.

At the next time t3, since the electric coil 72a is de-energized, the plunger 73a is returned downward by the repulsive force of the thin film 60, which causes the chamber 51a to have a negative pressure and the diaphragm 21a to retreat. Input port 11
The driven fluid is sucked by the diaphragm 21a. Since the diaphragm 21b is bulged, the driven fluid on the diaphragm 21b side is not substantially sucked. At time t3, the electric coil 72c is energized, and the diaphragm 21c is moved to the fluid flow path 13 in the same manner as described above.
Swell to. At this time, most of the driven fluid on the upper side of the diaphragm 21c is pushed toward the diaphragm 21d because the diaphragm 21b is bulging.

At the next time t4, since the electric coil 72b is de-energized, the plunger 73b is returned downward by the repulsive force of the thin film 60, which causes the chamber 51b to have a negative pressure and the diaphragm 21b to retract. Diaphragm 2
The driven fluid on 1a is sucked by the diaphragm 21b. Since the diaphragm 21c is bulged, the driven fluid on the diaphragm 21c side is not substantially sucked.
At time t4, the electric coil 72d is energized, and the diaphragm 21d is moved to the fluid flow path 1 in the same manner as described above.
Bulge to 3. At this time, since the driven fluid above the diaphragm 21d is bulging in the diaphragm 21c,
Most are pushed in the direction of the diaphragm 21e.

At the next time t5, since the electric coil 72c is de-energized, the plunger 73c is returned downward by the repulsive force of the thin film 60, which causes the chamber 51c to become a negative pressure and the diaphragm 21c to retract. Diaphragm 2
The driven fluid on 1b is sucked by the diaphragm 21c. Since the diaphragm 21d is bulged, the driven fluid on the diaphragm 21d side is not substantially sucked.
At time t5, the electric coil 72e is energized, and the diaphragm 21e moves to the fluid flow path 1 in the same manner as described above.
Bulge to 3. At this time, the driven fluid on the upper side of the diaphragm 21e has the diaphragm 21d bulging,
Most are pushed in the direction of the second port 12.

The next time t6 is the same as the state at time t1 described above. In this way, the swelling / retracting vibrations of the diaphragms 21a to 21e, which repeat one cycle from the time t1 to t6, are similarly repeated, and the driven fluid is the first port 1.
1 is inhaled and delivered to the second port. The adjacent diaphragms are sequentially driven to bulge with a time difference, but there is a period in which both bulges overlap each other. Explaining three adjacent diaphragms, when the central diaphragm bulges. Since the diaphragm on the downstream side (second port side) is bulged and the diaphragm on the upstream side (first port side) is switched to evacuate with respect to the direction in which the driven fluid is fed, the bulging of the downstream diaphragm is corrected. The pressure (discharge pressure) does not substantially propagate to the upstream side, and the negative pressure (suction pressure) due to the retraction of the upstream diaphragm does not substantially propagate to the downstream side, and the driven fluid is fed by the vibration of the diaphragm. High efficiency. When the resistance value of the potentiometer 95 is changed, the period of the pulse A generated by the pulse generator 94 changes to long or short, and the time of one cycle (time t6-t1) becomes long or short. Generally speaking, the longer the delivery speed (flow rate / time), the shorter the delivery speed, and the faster the delivery speed can be adjusted with the potentiometer 95.

In the case of the energizing circuit shown in FIG. 2, the energizing duty (continuous energizing time in one cycle × 100/1 cycle time%) is 40% (2 × 100/5), which cannot be changed. . Therefore, in the modified example of the first embodiment, for example, the energization control circuit 100 is a control circuit using a computer mainly composed of a CPU and an input board for inputting numerical values by using an energization circuit capable of changing the energization duty. Instead, the energizing duty may be changed. Even in this case, while the intermediate one of the three adjacent diaphragms is bulging, the upstream diaphragm switches to the retreat and the downstream diaphragm switches to the expansion even if there is a relative time difference.
The energization duty is 1 × 10 5 with 2 × 100 / n% (n is the number of diaphragms arranged, n = 5 in the first embodiment) as the center.
It is preferable to set the range of more than 0 / n% to less than 3 × 100 / n% in order to improve the driving efficiency, and for example, when the energizing duty is 2 × 100 / n%, the delivery speed becomes peak. , Energizing duty is 1 × 100 / n% and 3 × 100 / n%, 2
Since the delivery speed is almost half that of × 100 / n%, 1
The delivery speed is roughly set by adjusting the cycle time, and the
Finely set the delivery speed by adjusting within the range of 1 x 100 / n% to 2 x 100 / n% of the tee. The reverse is also possible. Thereby, the delivery speed can be adjusted more finely. FIG. 4 shows the pump mechanism of the second embodiment of the present invention. The structures of the flow path member 10 of the second embodiment and the silicon plate 20 and the upper relay plate 30 inside thereof are the same as those of the first embodiment described above. In the second embodiment, the lower relay plate 52 and the tubular body 53 communicating with the gas passages 31a to 31e of the upper relay plate 30.
a to 53e are erected, and the lower ends of the tubular bodies 53a to 53e are supported by a support plate 54 below. The support plate 54 is hollow, and the space communicates with the inner spaces of the pipe bodies 53a to 53e, and the inner space of the support plate 54 and the pipe bodies 53a to 53e.
The magnetic fluid 55 is stored in e. Tubular bodies 53a to 53
Each of the electric coils 72a to 72e and each of the ring-shaped permanent magnets 74a to 74e are attached to each of e. That is, for example, with respect to the tubular body 53a, the tubular body 53 penetrates through the center holes of the ring-shaped permanent magnet 74a and the electric coil 72a. Permanent magnets 74a-74
e is polarized and magnetized in a direction in which the tubular bodies 53a to 53e extend (may be radial polarized magnetization).

When the electric coils 72b and 72c are energized, the magnetic force generated by them causes the tubular bodies 53b and 5c
The magnetic fluid 55 of 3c is pulled up, whereby the diaphragms 21b and 21c swell as shown in FIG.
Although the amount of magnetic fluid in the tubes 53b and 53c increases, the amount of magnetic fluid in the other tubes decreases, but the total amount of magnetic fluid in the support plate 54 and tubes 53a to 53e is It is, of course, constant. The electric circuits shown in FIG. 2 are energized to the electric coils 72a to 72e shown in FIG. 4, as in the first embodiment. Therefore, the diaphragm 72
The operations a to 72e are the same as in the case of the first embodiment.
Since the magnetic fluid is used in place of the plunger in this second embodiment, for example, FIG. 4 shows time t3 to t4 shown in FIG.
However, since the energization of the electric coil 72b is stopped and the energization of the electric coil 72d is started at time t4, the magnetic fluid in the pipe body 53d is pulled up and the pipe body 53 is drawn.
The magnetic fluid of b falls, but since the pulling up and the fall are in a complementary relationship (one helps the other), the energy required to drive the magnetic fluid is small and the energy loss is low. The other actions, effects, and modified examples are the same as those in the above-described first embodiment.

FIG. 5 shows the pump mechanism of the third embodiment of the present invention. The structure of the flow path member 10, the silicon plate 20, the upper relay plate 30, the lower relay plate 50, and the thin film 60 in the third embodiment is the same as that of the first embodiment. In the third embodiment, the upper end surfaces of the push rods 75a to 75e supported by the guide plate 56 so as to be movable in the vertical direction hit the thin film 60. The lower surfaces of the push rods 75a to 75e are in contact with the peripheral surfaces of cam-shaped cams 76a to 76e having peripheral surfaces. The cams 76a to 76e are fixed to the rotary shaft. The cams 76a to 76e have exactly the same peripheral surfaces, but are fixed to the rotary shaft 96 with an angular difference of 72 ° between adjacent cams. The rotary shaft 96 is connected to the output shaft of a flat electric motor unit 97 (the output shaft of the reduction gear mechanism) which incorporates the reduction gear mechanism. The rotating shaft 9 is viewed from the side of the electric motor unit 97.
6 is driven to rotate clockwise. In the state shown in FIG. 5, the cam 76b has its peak aligned with the rod 75b, and the rod 75b is at the top dead center. Cam 76a
Is rotated by 72 ° in the clockwise direction with respect to the cam 76b, the cam 76c is rotated by 72 ° in the clockwise direction with respect to the cam 76b, and the cam 76d is rotated by the cam 7d.
It is rotated by 72 ° in the clockwise direction with respect to 6c, the short axis of the cam 76d is aligned with the rod 75d, and the rod 75d is at the bottom dead center. Cam 76e
Is rotated by a delay of 72 ° in the clockwise direction with respect to the cam 76d. That is, the mounting angles of the cams 75a to 75e are sequentially shifted in this order by 72 ° in the clockwise direction.

Therefore, from the state shown in FIG.
Is further rotated clockwise by 72 °, the rod 75a is lowered to the bottom dead center, and in this process, the diaphragm 21a is retracted to suck the driven fluid from the first port 11 and the rod 75b.
Is lowered by half the stroke of the reciprocating stroke, and in this process the diaphragm 21b begins to retract and the suction of the driven fluid is started. The rod 75c reaches the top dead center and the diaphragm 2b is reached in this process.
1c pushes the driven fluid, and rod 75d reciprocates.
Halfway up, the diaphragm 21d starts to bulge and starts pushing the driven fluid in this process, the rod 75e reaches the top dead center, and the diaphragm 21e sends the driven fluid to the second port in this process. And it stops. In this manner, the rotation of the rotary shaft 96 in the clockwise direction by the electric motor 97 causes the rods 75a to 75e to reach the top dead center closer to the first port 11 and the second port 12 in order. , And the diaphragm 21a ~
The swelling of 21e changes, and the driven fluid in the fluid passage 13 is sent to the second port 12 while the driven fluid is sucked from the first port 11. One rotation of the rotating shaft 96 causes the rod 75
a to 75e reciprocates twice. That is, the diaphragms 21a-21e vibrate for two cycles. When the rotation speed of the electric motor 97 is increased, the number of repetitions of this feed vibration (times / hour) increases, and the delivery speed of the driven fluid increases. Other actions and effects are similar to those of the above-mentioned first embodiment.

[0030]

EFFECTS OF THE INVENTION There is a working gas space (22a to 22e) between the reciprocating body and the diaphragm, and the gas (air) in the space is compressible (contracts when the pressure increases and expands when the pressure decreases). Therefore, even if the reciprocating body reciprocates in a pulsed (two-positional) manner, the pressure applied to the diaphragm is sine wave (sine wave) due to contraction / expansion of gas.
The bulging / retracting motion of the diaphragm (21a-21e) with respect to the working gas space (22a-22e) is smooth and soft, and the fluid delivered by this has a higher frequency than the reciprocating vibration of the diaphragm. Virtually no pressure oscillations or pressure shocks in the area occur. The fluid delivered will be closer to a static flow.

Since the gas in the working gas space (22a-22e) is compressible, no sharp pressure is applied to the diaphragm, and the probability that the diaphragm will be broken by the pressure shock is low. Therefore, the diaphragm may be thin and small in size.
The thinner and smaller the diaphragm, the lower the flow rate.
Nevertheless, the flow rate can be adjusted by adjusting the repetitive cycle of the vibration of the reciprocating body in addition to the fact that the flow rate does not substantially fluctuate. Therefore, it is possible to realize a micropump having a required low flow rate and an adjustable flow rate. The diaphragm is
Since the shape of the tube of the conventional roller pump does not change with time, the delivery amount does not substantially decrease with time.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a pump mechanism of a first embodiment of the present invention.

FIG. 2 shows electric coils 72a to 7 shown in FIGS.
It is a block diagram which shows the electric circuit which energizes 2e.

3 is a time chart showing electric signals of respective parts of the energization control circuit 100 shown in FIG.

FIG. 4 is a vertical sectional view showing a pump mechanism of a second embodiment of the present invention.

FIG. 5 is a vertical sectional view showing a pump mechanism of a third embodiment of the present invention.

[Explanation of symbols]

10: Flow path member 11: First port 12: Second port 13: Driven fluid flow path 15, 16: Claw groove 20: Silicon plate 21a to 21e: Diaphragm 22a to 22e: Gas chamber 30: Upper relay plate 31a to 31e: Gas passage 32: Fine groove 41 to 43: Adhesive film 50: Lower relay plate 51a to 51e: Gas chamber 52: Lower relay plate 53a to 53e: Tubular body 54: Support plate 55: Magnetic fluid 56 : Guide plate 60: Thin film 70a to 70e: Solenoid 71a: Core 72a to 72e: Electric coil 73a: Plunger 74a to 74e: Permanent magnet 76a to 76e: Cam 80: Lower case 81, 82: Claw 96: Rotation shaft 97 : Electric motor unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshinori Naruse 5-50, Hachikencho, Kariya city, Aichi Prefecture Aisin Cosmos Research Institute

Claims (7)

[Claims] 1. A flow path means having a first port, a second port, and a flow-through space for communicating them; each surface is exposed to the flow-through space and swells with respect to the space. A plurality of diaphragms that can be retracted and that are arranged in the direction from the first port to the second port along the flow space; disposed on the opposite side of the flow space with respect to the diaphragm; A diaphragm supporting means having a plurality of working gas spaces facing the back surface of the diaphragm; a plurality of reciprocating means for individually applying gas pressure vibration to each of the working gas spaces; and each of the reciprocating means. , A drive means for reciprocatingly driving with a phase difference in a relationship in which the top dead center for giving a high pressure peak to the working gas space changes in the direction from the one close to the first port to the one close to the second port. Pressure driven micropon . 2. A flow path means having a first port, a second port, and a flow-through space communicating with them; each surface of the flow-path means is exposed in the flow-through space and bulges with respect to the space. A plurality of diaphragms that can be retracted and that are arranged in the direction from the first port to the second port along the flow space; disposed on the opposite side of the flow space with respect to the diaphragm; A diaphragm supporting means having a plurality of working gas spaces facing the back surface of the diaphragm; an elastic thin film body for individually applying gas pressure vibration to each of the working gas spaces;
A plurality of solenoids, each of which is individually associated with each of the working gas spaces, including a plunger that impinges on the resilient thin film body and an electrical coil that drives the plunger to eject to cause the gas pressure oscillations; A plurality of solenoid drivers for individually energizing each of the solenoids; and a top dead center for applying a high pressure peak to the working gas space in the direction from the one close to the first port to the one close to the second port. A gas pressure-driven micropump, comprising: an energization control means for applying an energization signal to the solenoid driver with a phase difference in the relationship of the transition. 3. A flow path means having a first port, a second port, and a flow-through space for communicating them; each surface is exposed to the flow-through space and swells with respect to the space. A plurality of diaphragms that can be retracted and that are arranged in the direction from the first port to the second port along the flow space; disposed on the opposite side of the flow space with respect to the diaphragm; Diaphragm support means having a plurality of working gas spaces facing the back surface of the diaphragm; magnetism housed in each of the spaces communicating with each of the working gas spaces so as to be movable in a direction approaching the working gas space and in the opposite direction. A plurality of magnetic drive means each including an electric coil for driving the magnetic body in a direction of reducing the volume of the space communicating with the respective working gas space and a magnet for driving the electric coil in the opposite direction;
A plurality of solenoid drivers for individually energizing each of the electric coils; and top deadening for applying a high pressure peak to the working gas space in the direction from the one close to the first port to the one close to the second port. A gas pressure driven micropump, comprising: an energization control means for applying an energization signal to the solenoid driver with a phase difference in a relationship in which points change. 4. A flow path means having a first port, a second port, and a flow-through space for communicating them; each surface is exposed in the flow-through space and swells with respect to the space. A plurality of diaphragms that can be retracted and that are arranged in the direction from the first port to the second port along the flow space; disposed on the opposite side of the flow space with respect to the diaphragm; A diaphragm supporting means having a plurality of working gas spaces facing the back surface of the diaphragm; an elastic thin film body for individually applying gas pressure vibration to each of the working gas spaces;
A rod that strikes the resilient thin film body and a cam that drives the rod to eject to cause the gas pressure oscillations;
A plurality of cam / rod assemblies, each of which is individually associated with each of the working gas spaces; and a working gas space in the direction from the one closer to the first port to the one closer to the second port A gas pressure driven micropump comprising: a rotary shaft to which the cam is fixed with a rotation angle difference and an electric motor for rotationally driving the rotary shaft in a relationship in which a top dead center for giving a high pressure peak changes. 5. A gas pressure driven micropump according to claim 1, claim 2, claim 3 or claim 4, which has a fine gas escape channel communicating with the working gas space. 6. The diaphragm supporting means is a silicon plate; the diaphragm has a coefficient of thermal expansion lower than that of the silicon plate; claim 1, claim 2, claim 3, claim 4 or. The gas pressure driven micropump according to claim 5. 7. The gas pressure driven micropump according to claim 6, wherein the diaphragm includes a SiO ₂ layer produced in a high temperature atmosphere.