JP2011106324A - Electromagnetic piston pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic piston pump reducing the axial length of the electromagnetic piston pump and preventing fluid sucked once from undesirably flowing reversely to an outside of a suction port. <P>SOLUTION: The electromagnetic piston pump 1 includes: a casing 3 including the suction port 4 and a discharge port 2; and, in the casing 3, a hollow piston 12 with a suction and discharge valve 11, an exciting coil 5 wound around a bobbin 8, a soft iron flange 6 comprising a flange projection part 61 and a flange base part 62, a support shaft 9 reciprocatably supporting the piston 12, a permanent magnet 7 attached to one end of the support shaft 9, a piston shaft 10 fitted to another end of the support shaft 9, conical shape coil springs 15, 18 elastically supporting the piston 12, a holding plate 16 including a plurality of projection parts 161 and fixed on the piston 12, a suction chamber 13 sucking fluid from the suction port 4, and a pump chamber 17 discharging the fluid from the discharge port 2. The suction port 4 is blocked by the piston 12 at an early stage of expansion stroke. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electromagnetic piston pump that sucks and discharges fluid by reciprocating movement of a piston, and more particularly to an electromagnetic piston pump that uses a conical coil spring as a spring that reciprocally supports a piston.

  As a pump, an electromagnetic piston pump that sucks and discharges fluid by reciprocating movement of a piston is known (see, for example, Patent Document 1). In such an electromagnetic piston pump, a piston rod is connected to a piston disposed in a cylinder, and this piston rod is elastic so that it can be moved in the axial direction with respect to a casing by a cylindrical coil spring. It is supported. For example, it is of the movable wire ring type, and the piston is reciprocated through the piston rod by a linear motor consisting of an electromagnetic coil provided on the piston rod and a permanent magnet fixed on the casing side, and is partitioned by the piston in the cylinder. The fluid in the pump chamber is discharged by changing the volume of the formed pump chamber.

  In addition, although what is shown by patent document 1 is related to a large sized cooler, a cylindrical coil spring is used.

  As described above, an electromagnetic piston pump having a relatively large and powerful discharge port is known and generally used. However, a relatively small, so-called handy type electromagnetic piston pump, There is nothing affordable and its development is desired. That is, for example, it is expected to provide an inexpensive electromagnetic piston pump that can be used for cooling a small semiconductor electronic device with a size of a thumb. Needless to say, it can be applied up to the size of a fist.

  For this purpose, first, it is necessary to be able to operate under a frequency of 50 Hz or 60 Hz of a general commercial power supply without requiring a special power supply means for generating a required alternating voltage. In providing such an electromagnetic piston pump, there is no need for special power supply means for the mover, and the stator has a movable permanent magnet having an exciting coil that generates an alternating magnetic field under the frequency of a commercial power source. A magnet-type electromagnetic piston pump is considered.

  Since the exciting coil is driven under the frequency of the commercial power supply, the mover composed of permanent magnets needs to be reciprocated at a period corresponding to the frequency, and the mechanical system including the piston constituting the pump The magnitude of inertia is taken into account and the vibration period is commensurate with it.

  On the other hand, it is an essential requirement that the oscillating stroke be commensurate with the amount of fluid discharged, and obtaining the vibration cycle of the mechanical system under the stroke is an absolute requirement.

  Further, it is strongly desired that the fluid sucked into the suction chamber by the pump from the suction port from the fluid supply source in accordance with the reciprocation of the piston constituting the pump is effectively discharged to the discharge port. Furthermore, especially during the expansion stroke, as much as possible, the fluid sucked into the suction chamber from the suction port is undesirably reversed from the suction port toward the fluid supply source in accordance with the reciprocation of the piston. It is necessary to deter.

  As disclosed in Patent Document 1 described above, a so-called cylindrical coil spring is used as a spring that supports the movable element so as to vibrate. However, according to the inventor's experience, in the case of the cylindrical coil spring, the length in the compression direction of the spring when it is most compressed is, for example, about 1/3 under the uncompressed state, and the vibration stroke If you try to make it larger, there will be a limit. In the case of a cylindrical coil spring, the repulsive force corresponding to the compression is proportional to the compressed length. For this reason, during compression, the repulsive force increases from the middle of the compression, and a strong repulsive force may be generated even in the initial release when the compression of the spring is released. I found that I could not expect it.

  In a relatively small electromagnetic piston pump, the vibration cycle of the mechanical system should be commensurate with the frequency of the commercial power supply, and the vibration stroke is expected to be as large as possible.Furthermore, during the expansion stroke of the pump piston, In order to close the suction port as quickly as possible by moving the piston so that the fluid in the suction chamber in which the fluid is stored does not flow back through the suction port, a spring instead of the cylindrical coil spring is used. It turns out that the body needs to be used.

  Furthermore, it is necessary to devise so that the movement of the valve of the electromagnetic piston pump can be performed freely and quickly without being greatly influenced by the pressure increase / decrease associated with the fluid flow in the pump. It has been found.

JP-A-8-326651

  In the electromagnetic piston pump disclosed in Patent Document 1, a storage space for a cylindrical coil spring is formed, and the cylindrical coil spring is attached to the end face plate of the housing and the bottom of the storage space for the piston. However, in such an electromagnetic piston pump, the contact height (compression height) which is the length of the cylindrical coil spring in the most contracted state between the end face plate of the housing and the outer end face of the piston, It is necessary to secure at least a distance including a stroke in which the piston reciprocates. Further, although the elastic force of the cylindrical coil spring acts on the thrust of the piston, the elastic force of the cylindrical coil spring is substantially linearly proportional to the displacement length of the spring. Therefore, it is expected that the stroke will become smaller as the axial distance that the piston reciprocates is reduced and the device is miniaturized, and that a particularly strong repulsive force is obtained at the initial stage of release when the compression of the spring is released. Can not be expected. As a result, there has been a problem in reducing the size of the electromagnetic piston pump.

  The present invention provides an electromagnetic piston pump capable of reducing the axial length of piston reciprocation of an electromagnetic piston pump and ensuring a stroke in the axial direction of piston thrust and piston reciprocation. With the goal.

  In order to achieve the above object, an electromagnetic piston pump according to the present invention includes a hollow cylindrical casing having a suction port through which fluid is sucked and a discharge port through which fluid is discharged, and a fluid in the casing. A hollow piston with a suction / discharge valve that sucks in and discharges out of the casing, a support shaft that is fitted to one end of the piston so as to be able to reciprocate, and a support shaft insertion hole through which the support shaft is inserted. A flange made of a magnetic material formed in the casing, a bobbin wound with an exciting coil and provided in the casing, and a permanent magnet fixed to the other end of the support shaft and reciprocating in the bobbin The excitation piston, which is formed in a column shape as a part of the flange and is wound around the bobbin, is supplied with an alternating current to generate an alternating magnetic field on the bobbin. A flange projection magnetized in accordance with the flange base, and a flange base formed as a part of the flange and formed integrally with the flange projection, forming a flange together with the flange projection, and fixed in the casing; A first conical coil spring that is penetrated and supported by the support shaft and interposed between the permanent magnet and the flange convex portion, and supported by being penetrated by the support shaft and interposed between the piston and the flange base portion. The second conical coil spring to be mounted, and the piston in the position before the piston contacts the flange base, the piston is closed, and the piston is in a position where it is moving away from the position. The suction port formed so as to be opened at the inlet, the suction chamber for sucking fluid from the suction port into the casing, and the fluid flowing from the suction chamber in order to discharge the fluid from the discharge port The pump chamber, the fluid outlet from which the fluid flows from the pump chamber, the discharge port formed to be discharged from the pump chamber, and the space in the casing divided into a suction chamber and a pump chamber in two, Formed on the pump chamber side of the piston, the piston shaft connecting the piston and one end of the support shaft, the piston bottom portion formed on the suction chamber side of the piston, A piston head, a through-hole formed so as to pass through the opening of the piston bottom and the opening of the piston head, and a disk-shaped and disposed on the side of the piston head to be fixed. A plate, a suppressor hole formed as a hole in the center of the suppressor, a protrusion formed as a plurality of protrusions on the end surface on the through hole side of the suppressor, an end of the through hole, and a protrusion of the suppressor And move freely between The suction / discharge valve is accommodated in the piston head portion.

  According to the electromagnetic piston pump of the present invention, by using the conical coil spring, a necessary stroke can be ensured at a smaller distance in the axial direction of the reciprocating motion of the piston than when a cylindrical coil spring or the like is used. Therefore, the electromagnetic piston pump can be reduced in size.

  Further, since the conical coil spring can supplementarily apply a large thrust to the axial movement of the piston during the reciprocating motion of the piston, the piston can quickly close the suction port, and the fluid once sucked It is possible to shorten the time for the reverse flow from the suction port to the fluid supply source side. Thereby, it is possible to suppress the backflow of fluid from the suction port, and it is possible to realize an electromagnetic piston pump excellent in suction and discharge efficiency.

It is a longitudinal cross-sectional view which shows the structure of an electromagnetic piston pump. It is a longitudinal cross-sectional view which shows the structure of an electromagnetic piston pump. It is a cross-sectional view of an electromagnetic piston pump. It is a figure which shows an example of a conical coil spring.

  1 and 2 are longitudinal sectional views showing the configuration of an electromagnetic piston pump 1 according to an embodiment of the present invention. In particular, FIG. 1 shows the arrangement of components during the compression stroke of the electromagnetic piston pump 1, and FIG. 2 shows the arrangement of components during the expansion stroke.

  The electromagnetic piston pump 1 shown in FIG. 1 and FIG. 2 is configured as a movable magnet type in which a small permanent magnet is arranged in a movable portion in order to reduce the size. In the electromagnetic piston pump 1, for example, a casing 3 formed in a hollow cylindrical shape, a piston 12 in the casing 3, an excitation coil 5 wound around a bobbin 8, a support shaft 9 that supports the piston 12, Made of soft iron comprising a permanent magnet 7 attached to one end of the support shaft 9, a piston shaft 10 provided to drive the piston 12 to the other end of the support shaft 9, a flange convex portion 61 and a flange base portion 62. Flange 6 and conical coil springs 15 and 18. And it has the cover body 19 corresponding to the casing 3. FIG.

  In the casing 3, the piston 12, the support shaft 9, the flange 6, the conical coil spring 15, the permanent magnet 7, and the bobbin 8 are respectively attached as shown below.

  The piston 12 is slidably fitted into the casing 3 in order to suck fluid into the hollow cylindrical casing 3 and discharge (discharge) the fluid out of the casing 3. The detailed description of the piston 12 will be described later.

  The support shaft 9 is made of, for example, a non-magnetic metal, and the outer diameter of the support shaft 9 is slightly smaller than the diameter of the support shaft insertion hole 63 provided in the flange 6. The support shaft 9 is inserted into the support shaft insertion hole 63 of the flange base portion 62 and the flange convex portion 61, and the permanent magnet 7 is fixed to one end with the conical coil spring 15 interposed. A piston shaft 10 is fitted in a substantially cross shape at the other end of the support shaft 9.

  The permanent magnet 7 is formed in a cylindrical shape, for example, and when the side fixed to the support shaft 9 is an N pole, the other side is magnetized to an S pole.

  The piston 12, the support shaft 9, and the permanent magnet 7 can move integrally so that the piston 12 can reciprocate in the axial direction (the direction of the one-dot chain line TT ′ shown in FIGS. 1 and 2). Thus, each is provided coaxially within the casing 3, and the conical coil spring 15 is interposed between the flange convex portion 61 and the permanent magnet 7.

  The flange convex portion 61 is formed in a cylindrical shape, and the flange base portion 62 is formed in a disk shape. The flange 6 is formed by integrally forming a flange convex portion 61 and a flange base portion 62. The flange 6 is made of soft iron, for example, and alternately generates N poles or S poles on the end face of the flange convex portion 61 according to an alternating current conducted to the exciting coil 5. Needless to say, a repulsive force acts when the direction of the magnetic pole and the magnetic pole of the permanent magnet 7 is the same, and an attractive force acts when the magnetic pole is different, depending on the magnetic pole generated in the flange protrusion 61. .

  The bobbin 8 is made of a hollow cylindrical resin material, and the exciting coil 5 having a predetermined number of turns is wound around the bobbin 8. The bobbin 8 around which the exciting coil 5 is wound is fixed to the inner peripheral surface of the hollow cylinder of the casing 3. The exciting coil 5 is provided with a connection terminal so that an alternating current is conducted, and an alternating current of 50 Hz or 60 Hz from a commercial power supply is supplied via the connection terminal (not shown). The gap portion 14 is an air gap that separates a predetermined distance between the bobbin 8 and the permanent magnet 7.

  A suction chamber 13 is defined between the piston 12 and the flange base portion 62 in the casing 3, and the flange 6 is coaxially arranged so that the convex direction of the flange convex portion 61 is opposite to the suction chamber 13. It is inserted to become. The bobbin 8 is fixed in the casing 3 so as to cover the flange convex portion 61 having an outer diameter smaller than the hollow inner diameter of the bobbin 8 on the same axis.

  The conical coil spring 15 is an elastic body that elastically supports the piston 12, the support shaft 9, and the permanent magnet 7 together so as to be capable of reciprocating in the axial direction. The conical coil spring 15 is made of a nonmagnetic material, and has a spiral shape and a conical shape as a whole with the winding diameter and wire diameter of each coil spring so that the coil springs do not overlap in a compressed state. For this reason, the conical coil spring 15 works as a non-magnetized plate under the most compressed state. That is, the thickness when the conical coil spring 15 is most compressed works as a gap material between the permanent magnet 7 and the flange convex portion 61, and the strength of the magnetic force can be controlled.

  FIG. 4 is a diagram showing an example of the conical coil spring 15. In particular, the left diagram shows a top view (shown by a black line) of the conical coil spring 15 viewed from the cone apex side, and the right diagram shows the conical coil spring 15. The side view (indicated by a white line) is shown. In FIG. 4, the number of turns of the conical coil spring 15 is reduced for the sake of simplicity, and the number of turns is actually larger than the number of turns shown. One end of the conical coil spring 15 on the conical apex side is supported so as to be in contact with the permanent magnet 7, and the other end on the conical bottom side is in contact with the flange protrusion 61 under the compressed state of the conical coil spring 15. The The conical coil spring 15 is interposed between the permanent magnet 7 and the flange convex portion 61 with the support shaft 9 inserted through the conical coil spring 15. As shown in FIG. 4, the conical coil spring 15 is configured such that the coil springs do not overlap each other, and can be compressed to a thickness corresponding to the wire diameter of the conical coil spring 15 itself at the time of maximum compression.

  The suction port 4 is a pipe through which fluid sucked into the electromagnetic piston pump 1 from a fluid supply source (not shown) passes through the suction chamber 13 in the casing 3. The suction port 4 is in a state where the opening of the suction port 4 is closed by the piston 12 in a state before the piston 12 contacts the flange base portion 62, and the piston 12 is moving from the position in the T direction shown in the drawing. In this state, the suction port 4 is formed to be opened.

  The suction chamber 13 is a space formed in the casing 3 between the end of the flange base 62 on the suction port 4 side and the piston bottom 121 of the piston 12. The suction chamber 13 and the suction port 4 are connected so that fluid can flow. That is, the fluid sucked into the suction chamber 13 is sucked from the suction port 4 by moving the piston 12 from the position shown in FIG. 2 to the position shown in FIG. During this time, the fluid in the pump chamber 17 is discharged from the discharge port 2.

  The conical coil spring 18 is used as a cushioning material for preventing the piston 12 from colliding with the flange base portion 62. The conical coil spring 18 is made of a nonmagnetic material, and has a spiral shape and a conical shape as a whole with the winding diameter and wire diameter of each coil spring so that the coil springs do not overlap in a compressed state. One end on the conical bottom side of the conical coil spring 18 is fixed to the flange base 62, and the other end is released. The conical coil spring 18 is sandwiched and compressed between the flange base portion 62 and the piston shaft 10 during the expansion stroke of the piston 12 as shown in FIG. Thereby, the collision between the piston 12 and the flange base portion 62 is avoided.

  The piston 12 sucks fluid into the casing 3 and discharges fluid outside the casing 3, so that the piston bottom portion 121 having a predetermined bottom space on the bottom side of the piston 12, the fluid is sucked into the suction chamber 13, and the pump chamber 17. And a piston head part 123 having a predetermined space on the head side of the piston 12. The bottom side of the piston 12 is the suction chamber 13 side in the axial direction of the casing 3, and the head side is the pump chamber 17 side.

  FIG. 3 is a view showing a transverse section of the piston 12. In particular, FIG. 3 (A) is a transverse section of a broken line portion PP ′ shown in FIG. 1, and FIG. 3 (B) is a broken line portion QQ ′. Similarly, FIG. 3C is a cross-sectional view taken along broken line RR ′.

  As shown in FIG. 3A, the piston bottom portion 121 is formed in a hollow bowl shape with a smaller diameter than the outer diameter of the piston 12, and the piston shaft 10 is fixed inside the piston bottom portion 121. The piston shaft 10 is a member having a round bar shape for connecting the piston 12 and the support shaft 9. A round rod shape of the piston shaft 10 penetrates one end of the support shaft 9 and is fitted to one end of the support shaft 9 in a substantially cruciform shape so that the bottom direction of the piston 12 is the longitudinal direction. The both ends of the piston shaft 10 in a round bar shape are fixed to the piston bottom portion 121.

  As shown in FIG. 3 (B), the through hole 122 penetrates the piston bottom portion 121 and the hollow bowl-shaped opening portion of the piston head portion 123, and the inner diameter of the piston bottom portion 121 and the piston head. It is formed as a cylindrical through hole having a smaller diameter than the inner diameter of the opening of the portion 123. The end portion on the piston bottom portion 121 side is a flat surface across the through hole 122, while the end portion on the piston head portion 123 side is formed in a hollow cylindrical convex shape.

  The piston head portion 123 is formed in a hollow bowl shape on the head side (pump chamber 17 side) of the piston 12. As shown in FIG. 3C, the suppression plate 16 is fixed to the piston head portion 123 so as to close the inside of the hollow collar.

  The suppression plate 16 has a suppression plate hole 162 having a diameter approximately the same as the diameter of the through hole 122 of the piston 12 in the center of the concentric circle, and a plurality of protrusions 161 on the side facing the end of the through hole 122. It is a disk-shaped member. The suppression plate 16 is disposed in a space in the piston head portion 123 of the piston 12 and is fixed to the piston 12. The protrusion 161 is a protrusion formed by rounding the end face of the suppressor plate 16 on the side of the through hole 122, and is uniformly arranged on the circumference having a diameter smaller than the outer diameter of the suction / discharge valve 11. The plurality of protrusions 161 prevent the suction / discharge valve 11 from coming into close contact with the suppression plate 16 when the suction / discharge valve 11 moves toward the suppression plate 16 as shown in FIG.

  The suction / discharge valve 11 is a disk-shaped member, and the disk-shaped outer diameter is larger than the diameter of the through hole 122. The suction / discharge valve 11 is housed in the piston head portion 123 so as to be movable between the end portion of the through hole 122 and the projection portion 161 provided on the suppression plate 16.

  The pump chamber 17 is a space that is defined between the end on the discharge port 2 side in the casing 3 and the piston head portion 123 of the piston 12. The pump chamber 17 and the discharge port 2 are connected so that fluid can flow. That is, the fluid flowing into the pump chamber 17 is discharged from the discharge port 2 by moving the piston 12 from the position shown in FIG. 2 to the position shown in FIG. During this time, the fluid is sucked into the suction chamber 13 from the suction port 4.

  The pump operation of the electromagnetic piston pump 1 shown in FIGS. 1 and 2 will be described below. In the compression stroke in which the piston 12 moves in the axial direction of the discharge port 2 as shown in FIG. Thus, the flange protrusion 61 is magnetized to the south pole.

  That is, as in the example shown in FIG. 1, when the flange convex portion 61 is magnetized to the south pole by the alternating magnetic field of the bobbin 8, the permanent magnet 7 is moved by the magnetic field between the magnetized flange convex portion 61 and the permanent magnet 7. A suction force for moving in the right direction in the figure (T direction in the figure) is generated. As shown in FIG. 1, the piston 12 moves in an axial direction (T direction in the drawing) compressing the pump chamber 17 in conjunction with the support shaft 9 to which the permanent magnet 7 is fixed by this attractive force. The movement in this direction is referred to as backward movement. By the backward movement of the piston 12, the conical coil spring 15 between the permanent magnet 7 and the flange convex portion 61 is compressed.

  During the compression stroke, the volume of the suction chamber 13 increases as the piston 12 moves (returns). The suction port 4 is opened in the initial stage of the compression stroke, and the suction / discharge valve 11 is in close contact with the end of the through hole 122. When the suction port 4 is opened by the initial movement of the piston 12 in the compression direction, fluid is sucked into the suction chamber 13 from the suction port 4, and at the same time, the end portion of the through hole 122 is blocked by the suction / discharge valve 11. Since the volume of the pump chamber 17 decreases in this state, fluid is discharged from the pump chamber 17 through the discharge port 2 in accordance with the volume decrease of the pump chamber 17.

  Next, in the expansion stroke of the piston 12 as shown in FIG. 2, the exciting coil 5 is energized with an alternating current of a half cycle different from the compression stroke of a predetermined period, so that the polarity of the magnetic field due to this alternating current is increased. The flange protrusion 61 is magnetized to the north pole.

  That is, as in the example shown in FIG. 2, when the flange convex portion 61 is magnetized to the north pole by the alternating magnetic field of the bobbin 8, a repulsive force is generated by the magnetic field between the magnetized flange convex portion 61 and the permanent magnet 7. To do. The piston 12 moves in the axial direction (T ′ direction in the drawing) in which the pump chamber 17 is expanded in conjunction with the support shaft 9 to which the permanent magnet 7 is fixed by the repulsive force. Note that the movement in this direction is the forward movement. By the forward movement of the piston 12, the repulsive force stored in the conical coil spring 15 between the permanent magnet 7 and the flange convex portion 61 is rapidly released, and the conical coil spring 15 is rapidly expanded. By this extension, the speed at which the permanent magnet 7 is moved in the T ′ direction shown in the figure is made more rapid.

  During the expansion stroke, the volume of the pump chamber 17 increases with the movement (forward movement) of the piston 12. As a result, the suction / discharge valve 11 moves to and contacts the protrusion 161 of the suppression plate 16. Even if the suction / discharge valve 11 moves to the protrusion 161 side of the suppressor 16, a gap is formed between the protrusion 161 of the suppressor 16 and the intake / discharge valve 11 by the protrusion 161 of the suppressor 16. Therefore, in the initial stage of the compression stroke, the suction / discharge valve 11 is not undesirably brought into close contact with the suppression plate 16 and the movement in the T ′ direction in the drawing is not delayed.

  Further, as described above, the action of the conical coil spring 15 can increase the speed of the piston 12 in the expansion stroke in which the pump chamber 17 expands, so that the piston 12 rapidly closes the suction port 4. The time for the fluid once sucked into the suction chamber 13 to flow backward from the suction port 4 to the fluid supply source (not shown) can be shortened. Thereby, it can suppress that a fluid flows backward from the suction inlet 4. FIG.

At the end of the expansion stroke of the piston 12, the conical coil spring 18 is compressed to a predetermined compression distance in accordance with the movement of the piston shaft 10 fixed to the piston 12, as shown in FIG. A predetermined compression distance is determined so that the permanent magnet 7 does not collide with the end portion in the casing 3, and a conical coil spring 18 based on the predetermined compression distance is used. The conical coil spring 18 functions as a cushioning material, and the restoring force of the conical coil spring 18 acts strongly on the piston 12 at the initial stage of the compression state. Have Further, at the end of the expansion stroke, the conical coil spring 15 is substantially below the enlarged distance between the end of the flange convex portion 61 and the permanent magnet 7 moved to the leftmost end, as shown in FIG. Above, uncompressed and stretched.
(Overall operation)
The electromagnetic piston pump 1 shown in the embodiment of the present application reciprocates the permanent magnet 7 and reciprocates the piston 12 by supplying an alternating current to the bobbin 8 with the above configuration. As described above, at the initial stage of the expansion stroke of the piston 12, the elastic force due to the expansion of the conical coil spring 15 from the compression is utilized.

  In the case of the conical coil spring 15, when the compression distance L (m) of the conical coil spring 15 is set and the elastic force f = 0 (N) at the compression distance 0 (m) is set, the conical coil spring 15 is compressed. The elastic force f = fo (N) is substantially proportional to the square of the compression distance L. Thereby, at the initial stage of the expansion stroke of the piston 12 in which the conical coil spring 15 is compressed to the maximum, the elastic force f of the conical coil spring 15 works together with the repulsive force between the magnetic field of the flange convex portion 61 and the magnetic field of the permanent magnet 7. The acceleration when moving the piston 12 in the left direction (T ′ direction shown in FIG. 2) shown in FIG. 2 becomes extremely large. Therefore, in the expansion stroke in which the next pump chamber 17 expands, the piston 12 can be given a higher speed, and the piston 12 can close the suction port 4 rapidly. As a result, the fluid is transferred to the pump chamber 17 side as the volume of the suction chamber 13 decreases, and the fluid once sucked into the suction chamber 13 is rapidly suppressed from flowing backward from the suction port 4, and the fluid is made efficient. It can be sent to the pump chamber 17 well. Further, by using the conical coil spring 15, for example, a necessary stroke can be increased as compared with a case where a cylindrical coil spring or the like is used as an elastic body. That is, the axial length in the casing 3 for ensuring the necessary stroke can be further reduced. Thereby, size reduction of the electromagnetic piston pump 1 is attained.

  As described above, in the electromagnetic piston pump 1, the fluid such as the refrigerant sucked into the casing 3 flows into the casing 3 from the suction port 4 by the pump action due to the reciprocating motion of the piston 12, and the suction chamber 13, piston The liquid is discharged from the discharge port 2 through the bottom portion 121, the through hole 122, the piston head portion 123, and the pump chamber 17.

  As described above, according to the electromagnetic piston pump 1 of one embodiment of the present invention, the stroke required for the axial direction is smaller by using the conical coil spring 15 than in the case of using the cylindrical coil spring or the like. Can be ensured, and the electromagnetic piston pump 1 can be downsized. In the case of the present invention, the piston 12 can rapidly close the suction port 4 in the expansion stroke by the action of the conical coil spring 15, so that the fluid sucked into the suction chamber 13 from the suction port 4 can be efficiently used. It can be sent out to the discharge port 2 well. Further, since the protrusion 161 is present on the suppression plate 16, when the piston 12 changes from the expansion stroke to the compression stroke, the suction / discharge valve 11 is not attracted to the suppression plate 16 and is not easily separated. Immediately, it is pushed and adsorbed to the end of the through hole 122. Thereby, the suction / discharge valve 11 can discharge the fluid in the pump chamber 17 from the discharge port 2 by the backward movement of the piston 12 in a state where the end of the through hole 122 is closed during the compression stroke.

DESCRIPTION OF SYMBOLS 1 Electromagnetic piston pump 2 Discharge port 3 Casing 4 Suction port 5 Excitation coil 6 Flange 7 Permanent magnet 8 Bobbin 9 Support shaft 10 Piston shaft 11 Suction / discharge valve 12 Piston 13 Suction chamber 14 Gap part 15, 18 Conical coil spring 16 Suppression Plate 17 Pump chamber 19 Lid 61 Flange convex portion 62 Flange base portion 63 Support shaft insertion hole 121 Piston bottom portion 122 Through hole 123 Piston head portion 161 Protruding portion 162 Suppression plate hole

Claims (2)

A casing (3) formed in a hollow cylinder having a suction port (4) through which fluid is sucked and a discharge port (2) through which fluid is discharged;
A hollow piston (12) with a suction / discharge valve (11) for sucking fluid into the casing (3) and discharging it out of the casing (3);
A support shaft (9) that is fitted to one end of the piston (12) and supports the piston (12) so as to be reciprocally movable;
A support shaft insertion hole (63) through which the support shaft (9) is inserted, and a flange (6) made of a magnetic material provided in the casing (3);
A bobbin (8) wound around an excitation coil (5) and provided in the casing (3);
An electromagnetic piston pump (1) having a permanent magnet (7) fixed to the other end of the support shaft (9) and reciprocating in the bobbin (8),
The exciting coil (5) formed in a columnar shape as a part of the flange (6) and wound around the bobbin (8) is supplied with an alternating current to generate an alternating magnetic field on the bobbin (8). A flange protrusion (61) magnetized in response to the alternating magnetic field;
As a part of the flange (6), it is formed in a disk shape and integrally with the flange convex part (61), and constitutes the flange (6) together with the flange convex part (61), inside the casing (3) A flange base portion (62) fixed to the
A conical coil spring (15) that is penetrated and supported by the support shaft (9) and interposed between the permanent magnet (7) and the flange protrusion (61);
A conical coil spring (18) that is penetrated and supported by the support shaft (9) and interposed between the piston (12) and the flange base portion (62);
While the piston (12) is in a position before coming into contact with the flange base portion (62), the opening is closed by the piston (12), and the piston (12) is moving away from the position. The inlet (4) formed to be opened in the state of
A suction chamber (13) for sucking fluid into the casing (3) from the suction port (4);
A pump chamber (17) for flowing fluid from the suction chamber (13) to discharge fluid from the discharge port (2);
The discharge port (2) formed so that fluid can be circulated from the pump chamber (17) and discharged from the pump chamber (17);
The piston (12) sliding on the inner wall of the casing (3) by dividing the space in the casing (3) into the suction chamber (13) and the pump chamber (17);
A piston shaft (10) connecting the piston (12) and one end of the support shaft (9);
A piston bottom portion (121) formed on the suction chamber (13) side of the piston (12);
A piston head portion (123) formed on the pump chamber (17) side of the piston (12);
A through hole (122) formed so as to penetrate the opening of the piston bottom part (121) and the opening of the piston head part (123);
A restraining plate (16) formed in a disk shape and disposed and fixed to the piston head portion (123) side;
A suppressor hole (162) formed as a hole in the center of the suppressor (16);
A protrusion (161) formed as a plurality of protrusions on an end surface of the suppressor (16) on the through hole (122) side;
The suction / discharge valve accommodated in the piston head part (123) so as to be movable between the end part of the through hole (122) and the protrusion part (161) of the restraining plate (16). (11) The electromagnetic piston pump characterized by having. The electromagnetic piston pump according to claim 1, wherein the conical coil spring (15) is made of a nonmagnetic material.

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