JP2005315093A - Electromagnetic displacement type pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic displacement type pump alleviating water hammer action of fluid accompanied by opening/closing of a valve and suppressing noise. <P>SOLUTION: In the position where a valve element 40 contacting with and separating from a valve seat 41 by relative displacement is in the openest state, a flow passage cross section A of a portion where a gap between a valve part 42 and a seating part 44 is minimized, which is orthogonal to a flow, is formed so as to be equal to a cross section B of a flow passage of which diameter is smallest among flow passages formed between the valve element 40 and an inner wall face of an opening part. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to an electromagnetic positive displacement pump, and more specifically, an electromagnetic type that repeats the operation of sending and sucking fluid by reciprocating a mover by electromagnetic drive in a pump chamber used for transporting fluid such as gas and liquid. The present invention relates to a positive displacement pump.

In a positive displacement pump that sends or sucks fluid by changing the volume of the pump chamber, for example, when a mover that is reciprocally movable in a cylinder is operated, fluid in the pump chamber is sent and sucked. A check valve is provided in a reverse direction in the flow path (cylinder opening) of the pump chamber where the fluid is fed and sucked. In general, the check valve has a cylinder opening formed by opening and closing a valve body with a pin as a fulcrum shaft (not shown) or an elastically deformable valve body 101 such as a rubber plate in FIG. 7A. A swing valve provided to open and close the valve seat 102. In FIG. 7B, a spherical valve body 105 is freely attached to the valve seat 104 formed on the inner wall of the cylinder chamber 103 in accordance with the fluid pressure. A ball valve provided so as to be movable (see Patent Document 1), and a forced valve (see FIG. 7C) in which a valve element 106 such as a steel ball is urged by a coil spring 107 to close the valve seat 108 and open by fluid pressure ( Patent Document 2) or an electromagnetic valve (not shown) that opens and closes a valve by applying an electromagnetic force to a valve body (mover) by energization is used.
Japanese Patent Laid-Open No. 7-145871 JP-A-10-220605

  In the check valve provided in the positive displacement pump described above, for example, when the check valve on the suction side is opened and the fluid is flowing in the forward direction into the pump chamber, the operation of the mover (piston) is reversed. The fluid flowing in the direction temporarily flows in the opposite direction, and the valve closes. When the valve is closed, a fluid that has flowed in the opposite direction collides with the valve and a high fluid pressure is generated around the valve that is closed to cause a water hammer effect. The high pressure fluctuation due to the water hammer action may damage the parts constituting the flow path or cause noise. In particular, since the ball valve is closed only by the fluid pressure of the fluid, the flow in the reverse direction is large, and the water hammer sound accompanying the pressure fluctuation is large, which tends to be annoying noise.

  The present invention has been made to solve these problems, and an object of the present invention is to provide an electromagnetic positive displacement pump in which the water hammer action of the fluid accompanying the opening and closing of the valve is mitigated to achieve noise reduction. There is.

In order to achieve the above object, the present invention comprises the following arrangement.
A first configuration is an electromagnetic positive displacement pump that repeats the operation of sending and sucking fluid by reciprocating a mover by electromagnetic drive in a pump chamber. In the electromagnetic positive displacement pump, the fluid delivery side opening and the fluid suction side opening of the pump chamber A check valve that opens and closes only by a change in fluid pressure is provided in the opposite direction, and the valve body moves relative to the valve seat and moves toward and away from the valve body. The channel cross-sectional area perpendicular to the flow of the portion where the gap with the part is minimum is formed to be equal to the channel cross-sectional area having the minimum diameter among the channels formed in the valve.
In addition, a guide portion for making the moving direction of the valve body coincide with the direction of fluid flow is formed longer than the moving range of the valve body continuously to the valve seat on which the valve body contacts and separates. .
Further, the guide portion is formed so that the flow passage cross-sectional area formed between the valve body and the guide portion at the position where the valve body is most opened is larger than the flow passage cross-sectional area formed between the valve body and the seating portion. It is formed.
The second configuration is an electromagnetic positive displacement pump that repeats the operation of sending and sucking fluid by reciprocating the mover by electromagnetic drive in the pump chamber, and includes a fluid delivery side opening and a fluid suction side opening in the pump chamber. A check valve that opens and closes only by a change in fluid pressure is provided in the opposite direction, the valve part of the valve body seated on the valve seat has flexibility, and the shape of the seat part on which the valve part contacts and separates is It is characterized by being formed in a tapered surface or an R-surface shape.
Further, the outer shape of the valve body in plan view is characterized in that a concave portion or a convex portion is formed in a part of a circle, or an elliptical shape. Or the planar view external shape of the seating part which a valve body seats to a valve seat has the recessed part or convex part formed in a part of circular shape, or is characterized by the ellipse.
In the third configuration, a check valve that opens and closes only by a change in fluid pressure is provided in the pump chamber on the delivery side opening and the suction side opening, and the mover is moved electromagnetically in the pump chamber. In the electromagnetic positive displacement pump that repeats the reciprocating operation to send and suck the fluid, when the movable element that reciprocates by electromagnetic drive is reversed, the thrust acting on the movable element becomes 1/3 or less of the average thrust. The drive voltage or drive current is adjusted so that
Further, the drive circuit or the magnetic circuit is adjusted so that the thrust acting on the mover immediately after the mover is inverted is equal to or less than the average thrust.

When the electromagnetic positive displacement pump described above is used, the gap between the valve portion and the seating portion is minimized at the position where the valve body is moved relative to the valve seat to move toward and away. Since the cross-sectional area of the flow path orthogonal to the flow of the part is formed to be equal to the cross-sectional area of the smallest diameter of the flow paths formed in the valve, the gap between the valve body and the seating portion is reduced to reduce the fluid By reducing the backflow time and slowing down the fluid speed when closing the valve, the pressure rise due to the water hammer action can be reduced, the water hammer sound can be reduced, and the noise can be reduced. In addition, the smaller the flow path cross-sectional area perpendicular to the flow of the part where the gap between the valve part and the seating part is the smallest at the position where the valve body is most opened, the more the pressure of the fluid when passing through the valve body Loss increases and pump efficiency decreases, but if the channel cross-sectional area is formed to be equal to the channel cross-sectional area that is the smallest diameter among the channel cross-sectional areas formed in the valve, In addition, the flow velocity of the fluid flowing in the forward direction through the gap between the valve body and the seating portion does not increase more than necessary, and the noise associated with the water hammer action can be reduced without increasing the pressure loss so much.
Further, since the valve portion of the valve body seated on the valve seat is flexible, the volume change of the flow path becomes gentle by bending when the valve body is seated, and further, the valve portion is seated. The shape of the seating portion to be formed is a tapered surface or an R-surface shape, so that the volume change of the flow path when the valve is closed becomes gradual, and the slope of the pressure rise gradually changes over time. It is possible to reduce the frequency of noise generated by the hitting action to such an extent that it does not become annoying.
In addition, the planar view of the valve body has a concave or convex portion formed in a part of a circle, or is oval, or the planar view of the seat portion where the valve body sits on the valve seat has a circular shape. If the concave or convex part is formed in the part or is oval, the seated valve part needs to bend before the valve body is completely closed even if a part of the valve part is seated on the seat part. Therefore, since the flow velocity changes slowly and becomes zero, the pressure rise is alleviated and the water hammer sound can be reduced.
In addition, when the guide part for making the moving direction of the valve body coincide with the direction of fluid flow is formed longer than the moving range of the valve body, the valve body is closed. By guiding the axial movement of the valve element with the guide when valved, the valve closes in a short time because it is easy to receive the flow of fluid that the valve element flows backward, thereby reducing the flow rate when the valve element closes. Thus, the pressure rise due to water hammer can be reduced and the noise can be reduced. In addition, if the flow passage cross-sectional area formed between the valve body and the guide portion at the position where the valve body is most opened is larger than the flow passage cross-sectional area formed between the valve body and the seating portion, Road pressure loss can be reduced.
In addition, when the mover that reciprocates by electromagnetic drive is reversed, the drive voltage or drive current is adjusted so that the thrust acting on the mover is 1/3 or less of the average thrust, or the alternating current that flows through the electromagnetic coil When switching the energization direction, the valve element opens and the fluid flows in the forward direction by adjusting the drive voltage or drive current so that the thrust acting on the mover becomes smaller than the average thrust. Therefore, when the moving direction of the mover is reversed, the flow rate of the fluid that temporarily flows backward can be reduced to reduce the pressure increase due to the water hammer effect, thereby reducing the noise.
As described above, the first configuration for adjusting the flow path cross-sectional area of the valve, the second configuration for allowing the volume change of the flow channel when the valve body opens and closes, and the thrust when the mover is reversed are adjusted. According to any of the third configurations, the water hammer effect of the fluid accompanying the opening and closing of the valve can be mitigated by the synergistic effect of these combinations, and the noise can be reduced.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best embodiment of an electromagnetic positive displacement pump according to the present invention will be described in detail with reference to the accompanying drawings. In the electromagnetic positive displacement pump of this embodiment, a mover having a magnet (permanent magnet) is slidably disposed in the cylinder axial direction in a cylinder formed in a cylindrical shape, and an electromagnetic coil disposed on the outer periphery of the cylinder. The electromagnetic force is applied to the mover, and the mover is reciprocated to perform a pump action.

  In FIG. 1, the overall configuration of the electromagnetic positive displacement pump will be described. First, the configuration of the mover 10 will be described. The mover 10 is housed in a sealed cylinder and is provided so as to be able to reciprocate in the axial direction of the cylinder. The mover 10 includes a magnet 12 formed in a disc shape and a pair of inner yokes 14a and 14b that sandwich the magnet 12 in the thickness direction. The magnet 12 is a permanent magnet that is magnetized in the thickness direction (vertical direction in FIG. 1) with one surface as the N pole and the other surface as the S pole. The inner yokes 14a and 14b are formed of a magnetic material, and the outer peripheral surface of the flange portion 14c that stands up in a short cylindrical shape at the peripheral edge of each of the inner yokes 14a and 14b is a magnetic flux action on the movable element 10 side of the magnetic flux generated from the magnet 12. It becomes a surface.

  Next, the configuration of the stator 16 will be described with reference to FIG. A cylindrical cylinder cylinder 20 made of a nonmagnetic material (for example, a metal material such as a resin material or stainless steel) is fitted between the upper case 18a and the lower case 18b made of a pair of nonmagnetic materials, and the upper and lower opening ends are closed. A cylinder is formed. The movable element 10 described above is accommodated in the cylinder cylinder 20 so as to be able to reciprocate. The cylinder may be formed by combining the upper case 18a and the lower case 18b and thermocompression bonding.

  Thus, both end surfaces of the cylinder are closed by the upper case 18a and the lower case 18b, and pump chambers 22a and 22b are formed between both side surfaces in the moving direction of the mover 10 and the inner wall surfaces of the upper and lower cases 18a and 18b, respectively. The The movable element 10 slides in an airtight or liquid tightly sealed state in contact with the inner surface of the cylinder cylinder 20. In order to improve the slidability of the mover 10, the outer yokes 14a and 14b are coated with a coating having both lubricity and rust prevention such as fluorine resin coating and DLC (diamond-like carbon) coating. In addition, a rotation stopper that prevents the mover 10 from rotating in the circumferential direction may be provided.

  A damper (not shown) may be attached to the end surfaces (inner wall surfaces) of the upper and lower cases 18a and 18b. You may provide in the site | part which contact | abuts the inner yoke 14a, 14b of the needle | mover 10 and the inner wall surfaces of the upper and lower cases 18a, 18b.

  A suction check valve 24a and a delivery check valve 26a are provided at the suction opening and the delivery opening of the upper case 18a corresponding to the upper end surface of the cylinder so as to open and close the pump chamber 22a. A suction check valve 24b and a delivery check valve 26b are provided at the suction opening and the delivery opening of the lower case 18b corresponding to the lower end surface of the cylinder so as to open and close the pump chamber 22b. The suction check valves 24a and 24b and the delivery check valves 26a and 26b are attached to the openings in opposite directions.

  The upper case 18a is formed with a suction port 32 for circulating fluid to the pump and a delivery port 34 for sending fluid from the pump. The upper case 18a and the lower case 18b are respectively provided with suction flow paths 28a and 28b communicating between the suction port 32 and the suction check valves 24a and 24b. The upper case 18a and the lower case 18b are respectively provided with delivery channels 30a and 30b communicating between the delivery check valves 26a and 26b and the delivery port 34.

  In FIG. 1, air core electromagnetic coils 36 a and 36 b are fitted around a cylinder cylinder 20. The electromagnetic coils 36a and 36b are slightly spaced apart from each other in the axial direction of the cylinder, and are disposed so as to be at an equal position with respect to the central position of the cylinder cylinder 20 in the axial direction. Note that the winding directions of the electromagnetic coil 36a and the electromagnetic coil 36b are opposite to each other, and currents in opposite directions flow when energized by the same power source. The winding direction of the electromagnetic coils 36a and 36b is reversed because the electromagnetic force acting on the current flowing through the electromagnetic coils 36a and 36b interlinked with the magnetic flux of the magnet 12 is superimposed on the mover 10 as a reaction force. This is because this reaction force becomes a thrust.

The outer yoke 38 is provided in a cylindrical shape so as to surround the outer periphery of the electromagnetic coils 36a and 36b. A magnetic material is used for the outer yoke 38 and is provided in order to increase the number of magnetic fluxes linked to the electromagnetic coils 36 a and 36 b so that the electromagnetic force is effectively applied to the mover 10. Further, since the flange portion 14c is provided upright in the axial direction around the inner yokes 14a and 14b constituting the mover 10, the magnetic flux generated from the magnet 12 is transferred from the inner yokes 14a and 14b to the outer yoke 38. This is to lower the magnetic resistance of the magnetic circuit. As a result, the total amount of magnetic flux acting from the mover 10 is increased (a magnetic path through which the magnetic flux passes is secured), and the magnetic flux generated by the magnet 12 is perpendicular to the current flowing in the electromagnetic coils 36a and 36b and the axial direction. By interlinking, the thrust in the axial direction can be effectively generated in the mover 10. Further, since the mover 10 according to this configuration has a lighter mass than the generated thrust, a high-speed response is possible and the output flow rate can be increased.
When the upper case 18a and the lower case 18b are combined, the electromagnetic coils 36a and 36b and the outer yoke 38 are fitted to the cylinder cylinder 20 in the fitting grooves provided in the upper case 18a and the lower case 18b. It can be assembled concentrically with the cylinder 20.

  The mover 10 is reciprocally driven (moved up and down) by the action of electromagnetic force generated by the electromagnetic coils 36a and 36b by applying an alternating current to the electromagnetic coils 36a and 36b. The electromagnetic force acting on the electromagnetic coils 36a and 36b pushes the mover 10 in one direction and the other depending on the energizing direction of the electromagnetic coils 36a and 36b, so that a control unit (not shown) applies the electromagnetic force to the electromagnetic coils 36a and 36b. By controlling the energization time and the energization direction, the mover 10 can be reciprocated with an appropriate stroke.

  A sensor for detecting the moving position of the mover 10 in the cylinder may be provided, and the reciprocation of the mover 10 may be controlled based on a detection signal from the sensor. For example, a method of providing a magnetic detection sensor for detecting the moving position of the mover 10 outside the cylinder cylinder 20, a method of providing a pressure-sensitive sensor on a damper (not shown), and detecting a point in time when the mover 10 contacts the damper. Is possible. In the electromagnetic pump of the present embodiment, the moving stroke of the mover 10 is relatively small, but the pump chambers 22a and 22b can ensure a relatively large area. It is possible to secure a flow rate.

  Next, the structure of the check valve provided in the pump chambers 22a and 22b and the driving operation of the mover for alleviating the water hammer effect associated with the opening and closing of the valve will be described with reference to FIGS. Hereinafter, among the check valves provided at four locations, the delivery check valve 26a provided on the delivery side of the pump chamber 22a will be described as an example.

  2 (a) and 2 (b), the valve body 40 is provided with a valve portion 42 that sits on the valve seat 41 and blocks the flow path, and a stopper portion 43 that prevents the valve body 40 from flowing by fluid pressure. It has been. The valve body 40 may include a valve portion 42 that contacts and separates from the valve seat 41 and a portion other than the valve portion 42, which includes a plurality of parts. The planar shape of the valve body 40 is formed in a circular shape having one axial core (corresponding to the retaining portion 43 in this embodiment) parallel to the fluid flow path. The valve part 42 and the stopper part 43 are made of different materials or a combination of rubber materials having different hardnesses. Specifically, the valve portion 42 seated on the valve seat 41 is preferably made of a flexible material that is easily deformable or a soft rubber material. The retaining portion 43 is made of a material that is difficult to deform or a hard rubber material. In addition to changing the hardness of the rubber material, the valve portion 42 may be formed with a thin rubber material.

  In addition, the valve body 40 moves relative to the valve seat 41 and moves toward and away from the valve body 40. In the position where the valve body 40 is opened most, the gap between the valve portion 42 and the seating portion 44 is minimized. The cross-sectional area A (see FIG. 2 (a)) perpendicular to the flow path is equal to the cross-sectional area B (see the shaded portion in FIG. 2 (b)) having the smallest diameter among the flow paths formed in the valve. Formed. By reducing the gap between the valve body 40 and the seating portion 44 and shortening the time during which the fluid flows backward to slow the valve body 40 when closing the valve, the pressure increase due to the water hammer action is reduced and water is reduced. The impact sound can be reduced and the noise can be reduced. The smaller the flow path cross-sectional area A is, the more the pressure loss of the fluid when passing through the valve body 40 is increased and the pump efficiency is reduced. However, the flow path cross-sectional area A of the flow path formed in the valve is reduced. If it is formed to be equal to the flow path cross-sectional area B having the minimum diameter, the flow velocity of the fluid flowing in the forward direction through the gap between the valve body 40 and the seating portion 44 does not become larger than necessary when the valve is opened. The noise accompanying the water hammer effect can be reduced without increasing the pressure loss so much. It is important to equalize the channel cross-sectional areas A and B in order to reduce the pressure loss of the fluid passing through the valve. That is, the pressure loss in the flow path is proportional to the square of the flow rate change amount. Since the flow rate of the valve is faster than the flow rate of the flow path before and after the valve, the pressure loss of the valve is the power of (the maximum flow rate in the valve (passing through the valve)-the flow rate of the flow path before and after the valve). Is proportional to If the maximum flow velocity in the valve is not increased, the pressure loss of the valve will not be so great. For example, when the check valve 26a is opened, the flow passage cross-sectional area A between the valve portion 42 and the seating portion 44 is the smallest flow passage cross-sectional area B (the inlet portion of the fluid) of the flow passage cross-sectional areas excluding A. If it is smaller, the maximum flow velocity in the valve is determined by the flow path cross-sectional area B, so that the pressure loss of the valve is not so large. When the channel cross-sectional area A is smaller than the channel cross-sectional area B, the pressure loss of the valve is determined by the channel cross-sectional area A, so that the pressure loss of the valve increases rapidly as the channel cross-sectional area A decreases. Note that there is a tolerance in the outer diameter size and the opening size of the valve body 40, and in particular, since the valve portion 42 is flexible and deforms, the flow path cross-sectional area A is equal to the flow path cross-sectional area B, and at least It is desirable to be within a tolerance range of ± 30%.

  Further, since the valve portion 42 of the valve body 40 seated on the valve seat 41 is flexible, the fluid pressure in the vicinity of the valve body 40 after the valve body 40 is seated on the seat portion 44 as shown in FIG. However, the valve portion 42 is bent as shown in FIG. 4, so that the volume change of the flow path becomes gentle. Further, the shape of the seating portion 44 on which the valve portion 40 is seated is as shown in FIG. The taper surface or the R-surface shape also forms a gentle change in volume of the flow path when the valve is closed, and the slope of the pressure rise gradually changes over time. The frequency of the noise to be generated can be reduced to such an extent that it does not become annoying. For example, the frequency of the water hammer sound generated when the valve is closed is about 300 Hz, which is not so harsh with respect to a human ear having a frequency of about 2 kHz to 4 kHz.

  In addition, as shown in FIG. 5, the outer shape of the valve body 40 in plan view (the outer shape of the valve portion 42) is formed such that a concave or convex portion 42a is formed in a part of a circle, or is elliptical (or the valve body 40 is And the convex part 42a of the valve part 42 is seated on the seating part 44, and the convex part 42a of the valve part 42 is seated on the seating part 44. (See FIG. 3), the convex portion 42a needs to bend before the valve body 40 is completely closed (see FIG. 4). Water hammer sound can be reduced.

  Further, in FIG. 2A, a guide portion 45 for making the moving direction of the valve body 40 coincide with the direction of the fluid flow continuously to the valve seat 41 to which the valve body 40 contacts and separates moves the valve body 40. It is formed longer than the range. When the valve body 40 is closed in a short time by guiding the axial movement of the valve body 40 with the guide portion 45, the valve body 40 can easily receive the flow of fluid flowing backward, and the valve body 40 is closed in a short time. The flow rate of the water can be reduced, the pressure rise due to water hammer can be reduced, and the noise can be reduced. In order to reduce the pressure loss of the flow path, the flow path cross-sectional area C formed between the valve body 40 and the guide portion 45 at the position where the valve body 40 is most opened is between the valve body 40 and the seating portion 44. The guide portion 45 is formed so as to be larger than the formed channel cross-sectional area A (C> A). However, if the flow path cross-sectional area C is too large, the guide function of the valve body 40 is impaired, so it is necessary to make the range in which the guide function can be maintained.

In FIG. 1, when the movable element 10 reciprocally moved by electromagnetic driving is reversed, the drive voltage or the drive current is adjusted so that the thrust acting on the movable element 10 is 1/3 or less of the average thrust. preferable. Furthermore, it is desirable that the drive circuit or the magnetic circuit is adjusted so that the thrust acting on the movable element 10 immediately after the movable element 10 is inverted is equal to or less than the average thrust (see FIG. 6). Here, the magnetic circuit refers to the structure of the mover 10 and the stator 16. For example, even when the current values flowing through the electromagnetic coils 36 a and 36 b are the same, the thrust when the mover 10 moves above or below the moving range is centered. It can be considered that the configuration is such that it is less than the position (for example, the magnetic flux density is reduced).
Thereby, when the moving direction of the needle | mover 10 is reversed from the state which the valve body 40 opens and the fluid is flowing in the forward direction, the flow velocity of the fluid which flows backward temporarily is made small, and the pressure by a water hammer effect | action The rise can be reduced and the noise can be reduced.

  The operation of the above-described electromagnetic positive displacement pump will be described by the action of reciprocating the mover 10 with the electromagnetic coils 36a and 36b, whereby the fluid is alternately sucked into the pump chambers 22a and 22b and sent out. That is, when the mover 10 moves downward in the state of FIG. 1, the suction check valve 24a is opened by the fluid pressure in one pump chamber 22a, and the fluid is introduced at the same time. The delivery check valve 26b is opened by the fluid pressure, and the fluid is delivered. Conversely, when the mover 10 moves upward, the delivery check valve 26a in one pump chamber 22a is opened by the fluid pressure and fluid is delivered, and the suction check valve 24b in the other pump chamber 22b. Opens and fluid is introduced. In this way, when the mover 10 moves to either side, the fluid is sucked and discharged, and the pulsation of the fluid is suppressed and the fluid can be transported efficiently.

  Further, the electromagnetic positive displacement pump of the present embodiment can be used for transporting gas or fluid such as water or antifreeze, and the type of fluid is not limited. Further, when the transport pressure is insufficient with a single mover 10 when used as a fluid transport pump, a multistage in which a plurality of identical unit movers composed of magnets 12 and inner yokes 14a and 14b are connected. A mold movable element 10 may be used. By connecting the unit movers in multiple stages, the mover 10 having a large thrust can be obtained, and an electromagnetic positive displacement pump having a required transport pressure can be obtained.

  Further, a yoke made of a magnetic material may be interposed between the axial end surfaces of the electromagnetic coils 26a and 26b. In this case, since the magnetic circuit is formed by the yoke and the outer yoke 38 adjacent to both axial end surfaces of the electromagnetic coils 26a and 26b, the leakage magnetic flux can be reduced and the magnetic flux can be effectively used. It is possible to improve the pump output efficiency by reliably increasing the number of magnetic fluxes interlinked by energization.

It is sectional drawing which shows the whole structure of the electromagnetic positive displacement pump which concerns on this invention. It is explanatory drawing which shows the structure of a non-return valve. It is explanatory drawing of the state in which the non-return valve was seated. It is explanatory drawing of the state which the check valve bent. It is explanatory drawing which shows the planar view external shape of a valve part. It is a graph which shows the relationship between the displacement of a needle | mover, and thrust. It is explanatory drawing which shows the structure of the conventional valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Movable element 12 Magnet 14a, 14b Inner yoke 14c Flange part 16 Stator 18a Upper case 18b Lower case 20 Cylinder cylinder 22a, 22b Pump chamber 24a, 24b Suction check valve 26a, 26b Sending check valve 28a, 28b Suction Flow path 30a, 30b Delivery flow path 32 Suction port 34 Delivery port 36a, 36b Electromagnetic coil 38 Outer yoke 40 Valve body 41 Valve seat 42 Valve portion 42a Convex portion 43 Retaining portion 44 Seating portion 45 Guide portion

Claims (8)

In the electromagnetic positive displacement pump that repeats the operation of reciprocating the mover by electromagnetic drive in the pump chamber to send and suck fluid,
A check valve that opens and closes only by a change in fluid pressure at the fluid delivery side opening and the fluid suction side opening of the pump chamber is provided in the opposite direction, and the valve body moves relative to the valve seat and moves toward and away. The flow path cross-sectional area perpendicular to the flow of the part where the gap between the valve part and the seating part is the smallest at the position where the valve body is opened is the smallest diameter of the flow paths formed in the valve. An electromagnetic positive displacement pump characterized by being formed to have the same cross-sectional area.   The guide part for making the moving direction of the valve body coincide with the direction of fluid flow is formed longer than the moving range of the valve body in succession to the valve seat on which the valve body contacts and separates. The electromagnetic positive displacement pump according to 1.   The guide portion is formed so that the flow passage cross-sectional area formed between the valve body and the guide portion at the position where the valve body is most opened is larger than the flow passage cross-sectional area formed between the valve body and the seating portion. The electromagnetic positive displacement pump according to claim 2. In the electromagnetic positive displacement pump that repeats the operation of reciprocating the mover by electromagnetic drive in the pump chamber to send and suck fluid,
A check valve that opens and closes only by a change in fluid pressure is provided in a reverse direction at the fluid delivery side opening and the fluid suction side opening of the pump chamber, and the valve part of the valve body seated on the valve seat has flexibility. And the shape of the seating part to which the said valve part contacts / separates is formed in the taper surface or R surface shape, The electromagnetic positive displacement pump characterized by the above-mentioned.   5. The electromagnetic positive displacement pump according to claim 4, wherein the outer shape of the valve body in plan view has a concave part or a convex part formed in a part of a circle, or is elliptical.   5. The electromagnetic positive displacement pump according to claim 4, wherein the seat portion on which the valve body is seated on the valve seat has a circular shape in which a concave portion or a convex portion is formed in a part of a circle, or an elliptical shape. A check valve that opens and closes only by a change in fluid pressure is provided in the pump chamber on the delivery side opening and the suction side opening, and the mover is reciprocated by electromagnetic drive in the pump chamber to deliver fluid. In the electromagnetic positive displacement pump that repeats the suction operation,
The electromagnetic volume, wherein the driving voltage or the driving current is adjusted so that the thrust acting on the moving element is reduced to 1/3 or less of the average thrust when the moving element reciprocating by electromagnetic driving is reversed. Type pump.   9. The electromagnetic positive displacement pump according to claim 8, wherein the drive circuit or the magnetic circuit is adjusted so that the thrust acting on the movable element immediately after the movable element is reversed is equal to or less than the average thrust.

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