JP2005307777A - Pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pump to increase a discharge flow rate and improve an output in a range of a load pressure lower than a load pressure to give a maximum output, in a micropump wherein a pipe line element to generate an inertia effect of fluid is situated right behind the discharge side of a pump chamber instead of a check valve. <P>SOLUTION: The pump 10 is provided with a pump chamber 90 formed that a volume is variable by a diaphragm 50; an inlet flow passage 32 through which operating fluid flows in the pump chamber 90; an outlet flow passage 22 through which operating fluid flows out from the pump chamber 90; and a first fluid resistance element 40 situated between the inlet flow passage 30 and the pump chamber 90. A connection flow passage 28 to guide operating fluid not through the first fluid resistance element 40 is situated in a manner to join with the outlet flow passage 22. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pump that moves a working fluid by changing the volume of a pump chamber using a diaphragm, and more particularly to a small high-power pump.

  Conventionally, in a small pump that moves the working fluid by changing the volume of the pump chamber by means of a diaphragm, a pipe element that generates an inertia effect of the fluid is provided immediately after the discharge side of the pump chamber instead of a check valve. Output micropumps have been developed. (See Non-Patent Document 1 and Patent Document 1) Further, a jet pump that pumps up another low-energy fluid by a fluid jetted with energy is generally known.

JP 2002-322986 A “High output of micropump using inertial effect of fluid” The Japan Society of Mechanical Engineers Robotics Mechatronics Lecture '03 Proceedings 2A1-2F-E4

  In a small pump that moves the working fluid by changing the volume of the pump chamber by a diaphragm, a micropump in which a pipe element that generates an inertia effect of the fluid is provided immediately after the discharge side of the pump chamber instead of a check valve. As shown in Non-Patent Document 1, the output flow rate does not increase so much even if the load pressure decreases, and there is a maximum output point at a load pressure of 400 kPa or more. Therefore, when this pump is operated at a load pressure lower than the load pressure that gives the maximum output, there is a problem that only a smaller output than the maximum output can be obtained.

  An object of the present invention is to provide a range of a load pressure lower than a load pressure that gives a maximum output in a micropump in which a pipe element that generates an inertia effect of a fluid is provided immediately after the discharge side of a pump chamber instead of a check valve. Thus, it is an object to provide a pump with an improved output by increasing the discharge flow rate.

  The pump according to the present invention includes a pump chamber whose volume can be changed by a diaphragm, an inlet flow path for flowing the working fluid into the pump chamber, an outlet flow path for flowing the working fluid from the pump chamber, and the inlet flow path And a first fluid resistance element between the pump chamber and a connection flow path that guides the working fluid without passing through the first fluid resistance element. It is characterized by being.

  According to the present invention, the connection flow path that guides the working fluid without passing through the first fluid resistance element is provided so as to merge with the outlet flow path, and thus flows out from the pump chamber through the outlet flow path. Using the high energy of the working fluid, the working fluid can be introduced into the pump discharge side from the connection flow path, and the discharge flow rate increases when the load pressure is low.

  In the above-described structure, it is preferable that a second fluid resistance element is provided in the middle of the connection flow path.

  According to this structure, when the load pressure is relatively high, it is possible to reduce the flow rate that flows backward in the connection flow path from the discharge side to the suction side. Therefore, the flow rate increased by introducing the working fluid from the connection flow path to the pump discharge side using the high energy of the working fluid flowing out from the pump chamber through the outlet flow path without being lost by the backflow. Can be discharged.

  In the above structure, it is preferable that a nozzle connected to the outlet channel is provided inside the connection channel.

  According to this structure, the working fluid passing through the outlet channel can be ejected from the pump chamber, and the high energy can be effectively transferred to the working fluid existing around the nozzle. The flow rate is increased.

  In the above-described structure, it is preferable that one end of the connection channel is connected to the inlet channel.

  According to this structure, the pump can be configured in a small size while obtaining the above-described discharge flow rate increasing effect.

  In the above structure, the first fluid resistance element is preferably a check valve.

  According to this structure, since the pressure in the pump chamber can be sufficiently increased, the energy of the working fluid flowing out from the pump chamber through the outlet channel can be further increased, and the energy can be utilized. Thus, more working fluid from the connection channel can be introduced to the pump discharge side.

  In the above structure, the second fluid resistance element is preferably a check valve.

  According to this structure, when the load pressure is high, the back flow from the discharge side to the suction side can be prevented in the connection flow path. Therefore, the flow rate increased by introducing the working fluid from the connection flow path to the pump discharge side using the high energy of the working fluid flowing out from the pump chamber through the outlet flow path without being lost by the backflow. Can discharge reliably.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 2 show a pump according to an embodiment of the present invention.

  FIG. 1 is a longitudinal sectional view of the pump of the first embodiment. The direction of the arrow indicating the left direction in the figure is the direction in which the working fluid flows during pump operation. In FIG. 1, the pump 10 includes, as a basic configuration, a diaphragm 50 that changes the volume of a pump chamber 90 by expansion and contraction of an actuator 60, an outlet channel 22 through which a working fluid flows out, and a part of a connection channel 28. The pump chamber body 20 formed, the outlet channel nozzle 21 press-fitted into the opening of the outlet channel 22 of the pump chamber body 20, and the inlet connection pipe 31 formed with the inlet channel 32 into which the working fluid flows The outflow connection pipe 35 in which a part of the connection flow path 28 is formed, and the actuator housing 80 provided with the actuator 60.

  The pump chamber body 20 includes a pump chamber 90 and a valve seat chamber 23 that is a space formed by intersecting the check valve 40, the pump chamber 90, and the outlet channel 22 in the center. An outlet channel 22 is provided on the left side of the valve seat chamber 23 in the figure. The connecting portion between the valve seat chamber 23 and the pump chamber 90 is an opening 24 on the valve seat chamber side of the pump chamber 90, and the intersection 25 between the outlet flow path 22 and the opening 24 is a fluid resistance of the working fluid. It is rounded to reduce.

  A check valve 40 (first fluid resistance element) that opens and closes the connection with the inlet channel 32 is press-fitted and fixed to the right side of the valve seat chamber 23 in the drawing. The check valve 40 may employ a plate-like lead, a ball, or the like as an opening / closing member. In particular, by using a ball valve using a ball, when the working fluid passes through the ball valve, resistance to the working fluid due to bending of the flow hardly occurs, and the working fluid can flow smoothly. One end of the connection flow path 28 is opened between the connection portion with the inflow connection pipe 31 and the check valve 40. Further, a check valve 41 as a second fluid resistance element is press-fitted and fixed to the other opening of the connection flow path 28 in the pump chamber body 20. Here, the check valve 41 can be the same as the check valve 40.

  An outlet channel nozzle 21 formed therein with a reduced diameter portion for increasing the flow velocity of the working fluid is press-fitted and fixed to the outlet channel 22 opening of the pump chamber body 20 while being connected to the outlet channel 22. The outer shape of the outlet channel nozzle 21 is formed so as to become thinner toward the tip, and the thickness of the tip is 200 μm or less.

  Further, the outflow connection pipe 35 is press-fitted and fixed to the pump chamber body 20 so as to surround the outlet flow path nozzle 21 so that the inner surface of the outflow connection pipe 35 is substantially coaxial with the outer surface of the outlet flow path nozzle 21. . In addition, a part of the connection flow path 28 is provided inside the outflow connection pipe 35 and is press-fitted and fixed to the pump chamber body 20, whereby the connection flow path 28 and the outflow connection pipe 35 on the pump chamber body 20 side. The connection channel 28 on the side is connected via a check valve 41. Further, a narrow gap of 0.5 mm or less is maintained between the outer surface of the outlet channel nozzle 21 and the inner surface of the outflow connection pipe 35, and the working fluid flowing in from the connection channel 28 passes through the gap. It is possible to flow out from the outflow connection pipe 35. Furthermore, the inner surface of the outflow connection pipe 35 is reduced in diameter near the tip of the outlet channel nozzle, and then gradually increases in the downstream direction.

  In the opening of the pump chamber 90 of the pump chamber body 20, a thin disk-like diaphragm 50 formed of stainless steel or the like is closely fixed in a recess 26 provided at the periphery of the pump chamber 90. A convex portion 81 provided in the actuator housing 80 is press-fitted into the concave portion 26, and the pump chamber body 20 and the actuator housing 80 are integrated while pressing the diaphragm 50.

  The actuator housing 80 has a container-like shape with one open, and one end of the actuator 60 is fixed to the other sealed inner bottom surface. The actuator 60 is a piezoelectric element, and expands and contracts by receiving a drive voltage from an external control circuit (not shown). An actuator base 70 is fixed to the other end of the actuator 60, and the actuator base 70 is in close contact with the diaphragm 50.

  Although not shown, the inflow connection pipe 31 is connected to an external connection pipe to introduce a working fluid, and the outflow connection pipe 35 is also connected to an external connection pipe (not shown) to discharge the working fluid.

  Next, the operation of the pump of the present invention will be described.

  First, when the diaphragm 50 operates in a direction to reduce the volume of the pump chamber 90, the pressure in the pump chamber 90 and the valve seat chamber 23 increases according to the compressibility of the working fluid. Then, the check valve 40 is closed and the fluid resistance increases, so that the working fluid flows out from the check valve 40 into the inlet flow path 32 to be minute or zero.

  On the other hand, in the outlet channel 22 including the outlet channel nozzle 21, the flow rate at which the working fluid flows out from the valve seat chamber 23 increases according to the pressure difference between the pressure in the valve seat chamber 23 and the load pressure. At this time, since the flow paths inside the outlet flow path 22 and the outlet flow path nozzle 21 are formed narrowly and the working fluid inside thereof is difficult to accelerate, the pump is operated at a high load pressure that gives the maximum output. Like time, the pressure in the valve seat chamber 23 can be sufficiently increased. The working fluid having high kinetic energy is ejected from the end face of the outlet channel nozzle 21 by the increased pressure.

  The ejected working fluid gives kinetic energy to the working fluid around the end face of the outlet channel nozzle 21 and accelerates the working fluid around the end face of the outlet channel nozzle 21 in the discharge direction to the outflow side of the outflow connection pipe 35. Flowing. At this time, since kinetic energy is given to all the working fluids in the circumferential direction of the outlet channel nozzle 21, the structure of this embodiment has good energy transmission efficiency. As a result, a low pressure region is generated between the outlet channel nozzle 21 and the outflow connection pipe 35, and the check valve 41 that has been closed is opened to reduce the fluid resistance. The working fluid flows into the outflow connection pipe 35 through the connection flow path 28. As a result, a working fluid having a flow rate greater than or equal to the ejection flow rate from the outlet channel nozzle 21 can be discharged from the outflow connection pipe 35.

  Next, the volume of the working fluid in which the ejection flow rate from the outlet channel nozzle 21 is excluded by the displacement of the diaphragm 50 due to the inertia effect due to the kinetic energy stored in the working fluid in the outlet channel 22 (hereinafter referred to as the excluded volume). When the pressure of the working fluid in the pump chamber 90 and the valve seat chamber 23 is lower than the pressure in the inlet flow path 32, the check valve 40 is opened to reduce the fluid resistance, and from the inlet flow path 32. The working fluid flows into the valve seat chamber 23.

  Next, when the diaphragm 50 operates in the direction of increasing the volume of the pump chamber 90, the working fluid flowing into the valve seat chamber 23 from the already opened check valve 40 increases, and the valve seat chamber 23 and the pump chamber 90 are increased. Fully fill the interior with working fluid.

  Further, when the flow velocity of the working fluid ejected from the outlet channel nozzle 21 is reduced and the kinetic energy is decreased and becomes minute, the action on the working fluid around the end surface of the outlet channel nozzle 21 becomes weak, and the outlet channel nozzle The low pressure region between 21 and the outflow connection pipe 35 disappears. As a result, the check valve 41 is closed and the fluid resistance is increased, so that the working fluid flows out from the check valve 41 to the inlet flow path 32 side to be minute or zero. Therefore, even when the load pressure is high, the increased flow rate can be reliably discharged without losing the reverse flow.

  As described above, according to the pump of this embodiment, the pressure in the valve seat chamber 23 is sufficiently increased as when operating a pump that uses the inertial effect of a conventional fluid at a high load pressure that gives a maximum output. Can do. Then, the working pressure given high kinetic energy can be ejected from the outlet flow channel nozzle 21 by the increased pressure, and the kinetic energy of the ejected fluid is used to flow out the working fluid at a flow rate higher than the ejection flow rate. It can be discharged from the connecting pipe 35. Therefore, the discharge flow rate can be increased more than before. Also, the lower the load pressure, the greater the effect of increasing the flow rate.

  In the above embodiment, the check valve is used as the first fluid resistance element and the second fluid resistance element. However, the check valve can be changed depending on the load pressure to the pump. If the load pressure is low, a diffuser type fluid resistance element having a different fluid resistance depending on the flow direction may be used. In particular, if the load pressure is very small, the second fluid resistance element may be omitted. An effect can be obtained.

  Next, a second embodiment of the pump of the present invention will be described with reference to FIG. Example 2 is based on the structure of Example 1 (see FIG. 1), and is characterized in that an opening of a connection channel is provided in a part of the tube wall of the channel connected to the outlet channel. Yes. The same functional parts as those in the first embodiment are assigned the same numbers, and the description of the common parts with the first embodiment is omitted below.

  FIG. 2 is a longitudinal sectional view of the pump 10 of the second embodiment. In FIG. 2, the outflow connection pipe 350 is press-fitted and fixed to the pump chamber body 20. Inside the outflow connection pipe 350, connected to the outlet flow path 22, is a diameter-reduced portion 351 that gradually reduces the diameter to increase the flow velocity, an enlarged diameter portion 352 that decelerates the increased flow velocity and restores pressure, A part of the connection flow path 28 connected to the stop valve 41 is provided, and the opening of the connection flow path 28 is provided in the vicinity of the diameter of the reduced diameter portion 351 that is substantially the smallest.

  In the pump operation of the second embodiment, a portion different from the first embodiment will be described.

  The diaphragm 50 operates in a direction to reduce the volume of the pump chamber 90, the check valve 40 is closed, and the valve seat chamber 23 is at a sufficiently high pressure as when the pump is operated at a high load pressure that gives a maximum output. When the internal pressure is increased, the working fluid having high kinetic energy flows through the reduced diameter portion 351 in the discharge direction.

  Then, the working fluid that flows in the discharge direction through the reduced diameter portion 351 gives kinetic energy to the working fluid in the connection flow path 28 at the opening of the connection flow path 28, and the working fluid in the connection flow path 28 in the discharge direction. Shed. These working fluids pass through the enlarged diameter portion 352, recover pressure, and flow in the discharge direction.

  As a result, a low-pressure region is generated on the outflow connection pipe 350 side of the check valve 41, the check valve 41 that has been closed is opened, and the working fluid flows out from the inlet channel 32 through the connection channel 28. It flows into the connecting pipe 350. As a result, a working fluid having a flow rate greater than that of the reduced diameter portion 351 can be discharged from the outflow connection pipe 350.

  Further, when the flow velocity of the working fluid flowing through the reduced diameter portion 351 is reduced and the kinetic energy is decreased and becomes minute, the action of the connection channel 28 on the working fluid becomes weak at the opening of the connection channel 28, and as a result. The check valve 41 is closed. Therefore, even when the load pressure is high, the increased flow rate can be reliably discharged without losing the reverse flow.

  As described above, according to the pump of this embodiment, the pressure in the valve seat chamber 23 is sufficiently increased as when operating a pump that uses the inertial effect of a conventional fluid at a high load pressure that gives a maximum output. Can do. The increased pressure gives high kinetic energy to the working fluid flowing through the reduced diameter portion 351, and uses the kinetic energy to supply a larger amount of working fluid than the flow rate of the working fluid flowing through the reduced diameter portion 351 to the outflow connection pipe 35. It is possible to discharge more. Therefore, the discharge flow rate can be increased more than before. Also, the lower the load pressure, the greater the effect of increasing the flow rate.

  In the above embodiment, the check valve is used as the first fluid resistance element and the second fluid resistance element. However, the check valve can be changed depending on the load pressure to the pump. If the load pressure is low, a diffuser type fluid resistance element having a different fluid resistance depending on the flow direction may be used. In particular, if the load pressure is very small, the second fluid resistance element may be omitted. An effect can be obtained.

  The present invention is not limited to the first and second embodiments described above, but includes modifications and improvements as long as the object of the present invention can be achieved.

  For example, in the above-described first and second embodiments, the volume of the pump chamber 90 is changed by the diaphragm 50, but not only the diaphragm but also a piston can be employed.

  As described above, according to Example 1 and Example 2 described above, the pump that can discharge the working fluid more than the outflow amount from the outlet channel by using the kinetic energy of the working fluid flowing out from the outlet channel. Can be provided.

  The pump 10 of the present invention can be used as a cooling device for electronic equipment such as a projector, a water jet knife, a fluid actuator, a power source for a piston of a micro hydraulic press, and the like.

1 is a longitudinal sectional view of a pump according to Embodiment 1 of the present invention. The longitudinal cross-sectional view of the pump which concerns on Example 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Pump, 20 ... Pump chamber body, 21 ... Outlet flow path nozzle (nozzle), 22 ... Outlet flow path, 28 ... Connection flow path, 32 ... Inlet flow path, 35, 350 ... Outflow connection pipe, 40 ... Check Valve (first fluid resistance element), 41 ... Check valve (second fluid resistance element), 50 ... Diaphragm, 90 ... Pump chamber.

Claims (6)

A pump chamber whose volume can be changed by a diaphragm,
An inlet channel for flowing a working fluid into the pump chamber;
An outlet channel for allowing the working fluid to flow out of the pump chamber;
A first fluid resistance element between the inlet channel and the pump chamber;
A pump characterized in that a connection flow path for guiding the working fluid without passing through the first fluid resistance element is provided so as to join the outlet flow path. The pump according to claim 1, wherein
A pump characterized in that a second fluid resistance element is provided in the middle of the connection flow path. The pump according to any one of claims 1 to 2,
A pump characterized in that a nozzle connected to the outlet channel is provided inside the connection channel. The pump according to any one of claims 1 to 3,
One end of the connection flow path is connected to the inlet flow path. The pump according to any one of claims 1 to 4,
The pump according to claim 1, wherein the first fluid resistance element is a check valve. The pump according to any one of claims 1 to 5,
The pump according to claim 2, wherein the second fluid resistance element is a check valve.

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