JPH0625564U - Electromagnetic pump - Google Patents

Abstract

(57) [Abstract] [Purpose] Immediately after the driving is stopped, the fluid in the delivery passage is caused to flow back into the backflow passage by the principle of the siphon to prevent the fuel from dripping from the tip of the delivery passage. [Structure] Electromagnetic coil 4, plunger 3 that reciprocates in cylinder 2, check valve 15 that opens fluid sucked up by plunger 3 to delivery pipe 44 on the downstream side, and delivery pipe 44 on the downstream side of check valve 15 It is composed of a branched backflow pipe 7. The tip 72 of the backflow pipe 7 is the tip nozzle 14 of the delivery pipe 44.
Since it is set at a position lower than 4, the fluid remaining in the delivery pipe 44 flows back to the backflow pipe 7 side by the siphon principle.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of an electromagnetic pump that supplies liquid fuel to an oil combustor, for example.

[0002]

[Prior art]

 Conventionally, in order to supply liquid fuel from a tank to a combustion burner chamber of an oil combustor, a free piston-shaped plunger housed in a cylinder is moved forward by electromagnetic force and then returned by spring pressure. 2. Description of the Related Art There is known an electromagnetic pump in which a discharge check valve is pushed and opened by the pressure of a fluid pressurized during forward movement to discharge the fluid. Then, the discharged fuel is guided to the combustion burner chamber through the delivery pipe, where it is vaporized and burned. However, in this type of electromagnetic pump, there is a problem that the fuel drips after the driving is stopped and this causes a strange odor. This is because the tip of the delivery pipe is introduced into the combustion burner chamber, so the tip is under high temperature. Therefore, when driving is stopped, the fuel remaining at this tip expands and drops from the tip. Then, it is not burned and drops and remains on the bottom surface of the burner chamber, which gives off an offensive odor.

In order to solve such a problem, a check valve built in a plunger is formed of a flexible elastic body, and a leak hole is formed in a part of the check valve. In which the inside of the cylinder is made to flow backward to be returned to the tank side (Japanese Utility Model Laid-Open No. 61-147375), and a suction pump is provided in communication downstream of the delivery pump, and after the driving is stopped, this suction pump is It has been proposed to operate so as to suck and remove the fuel remaining in the delivery pipe (Japanese Utility Model Laid-Open No. 2-85236).

[0004]

[Problems to be solved by the device]

 In the conventional electromagnetic pump with the above-mentioned leak hole, the fuel in the cylinder is also returned to the tank through this leak hole, so the fuel supply cannot be performed quickly at the start of the next drive, and the electromagnetic force is generated without fuel. When the pump is driven, there is a problem that the driving noise becomes loud, that is, an abnormal noise is generated. In addition, the structure of a conventional pump equipped with a suction pump is complicated, which reduces reliability, increases size, and does not meet the demand for downsizing and cost reduction. A special control unit will be required.

The present invention has been made in view of the above, and a backflow passage is provided from an appropriate position in the delivery passage on the downstream side of the check valve in the cylinder, and after the driving is stopped, the fluid in the delivery passage is supplied to the reverse passage. The purpose of the present invention is to provide an electromagnetic pump that prevents fuel from dripping from the tip of the delivery passage.

[0006]

[Means for Solving the Problems]

 The present invention relates to a plunger that reciprocates in a cylinder by exciting an electromagnetic coil, a check valve that opens and closes in synchronization with the reciprocating motion of the plunger, and opens a fluid sucked from an upstream tank in a downstream direction. In an electromagnetic pump configured downstream of a check valve and having a delivery passage for guiding a delivery fluid downstream and delivering the delivery fluid from its tip, a backflow passage is provided branching from the delivery passage. The tip is set at a position lower than the tip of the delivery passage (claim 1).

Further, the delivery passage may have a portion having a height equal to or less than the height of the tip of the backflow passage (claim 2).

Further, it is preferable that the tip of the backflow passage is disposed so as to be immersed in the upper portion of the tank (claim 3).

Further, the tip of the backflow passage may be arranged below the liquid surface position in the tank (claim 4), and in this case, the height of the liquid surface in the tank and the height of the liquid surface in the delivery passage. You may make it have a part which is equal or less than it (Claim 5).

Further, it is preferable to form a constriction portion having an inner diameter smaller than the inner diameter of the ejection constriction portion formed in the delivery passage in a part of the backflow passage (claim 6).

Further, it is preferable to provide a liquid guide member from the tip of the backflow passage to the liquid surface in the tank (claim 7).

[0012]

[Action]

 According to the first aspect of the present invention, the plunger is reciprocated by the excitation of the electromagnetic coil, and the fluid in the upstream tank is sucked up by the action of the check valve and discharged in the downstream direction. Then, the fluid is guided to the downstream side through the delivery passage formed on the downstream side of the check valve, discharged from the tip thereof, for example, vaporized and burned. At this time, a part of the fluid delivered to the downstream side through the delivery passage flows to the backflow passage, but this electromagnetic pump is adjusted to a flow rate that takes into account the flow rate flowing out to the backflow passage in advance.

On the other hand, when the excitation of the electromagnetic coil is completed (driving is stopped), the fluid delivered to the tip of the delivery passage tries to drip from the tip. In particular, in the case of an oil combustor in which the vicinity of the delivery passage end is under high temperature, the fluid of oil expands and the tendency of dripping increases. However, at this time, since the backflow passage whose tip is located below the tip of the delivery passage functions as a siphon, the fluid in the delivery passage flows back to the backflow passage side and is collected or collected in a dedicated receiver, for example. Be accommodated. Therefore, the fluid at the tip of the delivery passage in the dripping state does not drip, but flows backward in the direction of the backflow passage. At this time, the check valve removes only the fluid remaining on the downstream side of the check valve into the backflow passage, and the fluid on the upstream side of the check valve is not affected.

According to the second aspect of the invention, the liquid in the portion from the tip position of the delivery passage to the position equal to the height of the tip of the backflow passage flows backward.

According to the third aspect of the invention, the fluid that has flowed back into the backflow passage is recovered from the tip thereof to the original tank.

According to the invention of claim 4, the liquid flows backward from the tip end position of the delivery passage to at least a position equal to the height of the liquid surface.

According to the fifth aspect of the invention, the liquid in the portion from the tip position of the delivery passage to the position equal to the height of the liquid surface flows backward.

According to the invention of claim 6, the inner diameter of the constriction portion of the backflow passage is smaller than the inner diameter of the discharge constriction portion of the delivery passage. On the other hand, the discharge flow rate is increased, and the fluid is sent to the downstream side of the discharge passage without much loss in efficiency.

According to the invention of claim 7, the liquid collected in the tank from the tip of the backflow passage is transmitted to the liquid guide member and drops, so that no dropping noise is generated.

[0020]

【Example】

 Hereinafter, the present invention will be described with reference to the drawings. 2 to 4 show first to third embodiments of the electromagnetic pump according to the present invention. FIG. 1 shows the electromagnetic pump and its surroundings when the electromagnetic pump is applied to an oil combustor. FIG. 6 is a schematic layout diagram showing a layout relationship with members.

First, the electromagnetic pump according to the first embodiment shown in FIG. 2 will be described. The main components of the electromagnetic pump 1 are a cylinder 2 having a cylindrical shape, a plunger 3 that reciprocates in the cylinder 2, an electromagnetic coil 4 that moves the plunger 3 forward, and a suction connected to the upstream and downstream sides of the cylinder 2. It consists of a tube 5, a discharge joint 6 and a backflow tube 7.

The plunger 3 is made of a free-piston-shaped tubular body, and is housed in the cylinder 2 together with an upper spring 8 and a lower spring 9 before and after the elastically stationary body. Inside the plunger 3, a check valve 12 for suction, which is pressed against a valve seat 11 by a weak valve spring 10, is arranged, and on the downstream side of the plunger 3, a weak valve spring 13 presses against a valve seat 14. Discharge check valves 15 are arranged respectively. The valve seats 11 and 14 are provided with holes 111 and 114 at their centers to secure a fluid passage.

The suction pipe 5 and the discharge joint 6 at both ends of the cylinder 2 are provided with a suction port 16 and a discharge port 17, and the fluid sucked from the suction port 16 passes through the inside of the cylinder 2 and the discharge port 17 Is sent to the downstream side (see FIG. 1).

A bobbin 18 around which the electromagnetic coil 4 is wound is provided at a substantially central position in the axial direction of the cylinder 2. Further, a terminal base 19 is formed so as to extend in a radial direction from an appropriate position on the upper flange portion of the bobbin 18. This terminal block 19 constitutes a relay connection terminal when connecting a lead wire from a drive circuit (not shown) to both ends of the electromagnetic coil 4, and adjusts the drive current to discharge the fluid from the discharge port 17. A fixed resistor 20 is provided in order to finely adjust. A cap 119 serves as a protective cover.

An upper annular magnetic path 21 and a lower annular magnetic path 22 are provided between the bobbin 18 and the cylinder 2, while the upper annular magnetic path 21 and the lower annular magnetic path 22 are provided outside the bobbin 18. A yoke 23 having a U-shaped cross-section is arranged so as to be connected to the, and a loop of a magnetic path is formed by these. The yoke 23 also serves as a mounting substrate, and the bobbin 18 is fixed to the outer periphery of the cylinder 11.

Incidentally, 24 and 25 are packings as seal members.

A passage 61 communicating with the discharge port 17 is formed at the axial center of the discharge joint 6, and a discharge narrowing portion 62 for appropriately adjusting the discharge amount is formed in a part of the passage 61.

Further, on the downstream side of the discharge check valve 15 and at a proper position on the side surface of the discharge joint 6, a small-diameter backflow constriction portion 63 penetrating from the inner surface to the outer surface is formed. The backflow pipe 7 is arranged so that its base end includes the discharge narrowing portion 63, and constitutes a branch passage for the delivery passage. That is, the backflow pipe 7 has the flange 71 formed at the base end thereof, and the flange 71 is attached and fixed in a state of being held between the O-ring 26 and the fixture 27. The backflow constriction portion 63 is set to have a diameter at least smaller than the inner diameter of the ejection constriction portion 62, so that when the electromagnetic pump is driven, the flow rate delivered from the ejection outlet 17 is delivered to the backflow pipe 7. The flow rate is larger than the flow rate and is efficiently delivered from the discharge port 17 to the downstream side. The backflow pipe 7 has a predetermined length and is bent downward in the middle thereof.

Next, the operation of the electromagnetic pump having such a structure will be described. When an adjusted driving pulse current is input from the driving circuit through the fixed resistor 20 at a predetermined cycle (starting driving), the electromagnetic coil 4 generates a DC magnetic field and the plunger 3 causes the upper spring 8 to move. And moves forward in the downstream direction of the cylinder 2. On the other hand, when the pulse current is cut off, the plunger 3 returns to the original rest position by the restoring force of the upper spring 8. In this way, such reciprocating operation is repeated during driving.

During forward movement, the suction check valve 12 is closed to pressurize the fluid on the upstream side of the cylinder 2, and the discharge check valve 15 is forcibly opened and discharged from the discharge port 17 to the downstream side. On the other hand, when returning, the discharge check valve 15 is closed to prevent the fluid on the downstream side of the discharge check valve 15 from returning to the upstream side, and the suction check valve 12 is opened to open the suction port. The fluid is sucked into the cylinder 2 from 16. Then, by repeating such forward and backward movements, the fluid is constantly sucked from the suction port 16 and delivered from the discharge port 17. The electromagnetic coil 4 may be supplied with an alternating current of a predetermined cycle.

The operation of the backflow pipe 7 when the driving is stopped will be described with reference to FIG.

Next, an electromagnetic pump according to the second embodiment shown in FIG. 3 will be described. The electromagnetic pump 1A according to the second embodiment has almost the same structure as that of FIG. 2 except for the structure in which the joint 30 is interposed. This point will be described below.

In this electromagnetic pump 1 A, a cylindrical dedicated joint 6 is provided on the downstream side of a general-purpose discharge joint 30 by screwing together with a packing 31. According to this structure, the electromagnetic pump provided with the general-purpose discharge joint 30 need not be refurbished, and only the dedicated joint 6 needs to be installed. Therefore, the cost and workability are excellent. Note that, in the figure, those denoted by the same reference numerals as those in FIG. 2 indicate the same elements, and description thereof will be omitted.

Next, an electromagnetic pump according to the third embodiment shown in FIG. 4 will be described. The electromagnetic pump 1B according to the third embodiment has substantially the same structure as that of FIG. 2, but the structure of the backflow pipe 7 is different. Hereinafter, this point will be described.

This electromagnetic pump 1B has a delivery pipe 40 communicated with the upstream side by being screwed into a discharge connector 6 having a screw threaded on an upper outer periphery thereof with a connector 41 having a screw threaded on an inner circumference thereof. is there. As shown in FIG. 1, the delivery pipe 40 has a required length and its tip nozzle is guided to the combustion burner chamber.

The delivery pipe 40 is bent, for example, downward in the middle thereof, and a branch portion 42 is provided at an appropriate position on the downstream side thereof. A small-diameter backflow constriction 43 is formed at the proximal position of the branch portion 42, and the backflow pipe 7 ′ is attached downward to communicate with the delivery pipe 40 so as to enclose the constriction 43. It constitutes a branch road.

Next, FIG. 1 will be described. FIG. 1 shows a state in which an electromagnetic pump 1A is installed in an oil combustor. The electromagnetic pump 1A is attached to an appropriate place above a base tank 50 for fuel, which is generally installed in the lower part of the oil combustor. ing. In addition, a cartridge 51 can be mounted at a proper place other than the base tank 50. On the other hand, a combustion burner chamber 52 is provided at an appropriate position in the lateral direction of the electromagnetic pump 1A.

An outlet 511 is normally provided at the lower end of the cartridge 51 in a closed state, and is opened by a protrusion 501 in a state of being loaded in the base tank 50. Therefore, the oil level 502 in the base tank 50 is always maintained at a constant level. Mounting holes 503 and 504 are formed on the upper surface of the base tank 50. The electromagnetic pump 1A is mounted and fixed to the mounting hole 503 at the lower end surface of the yoke 23, and the tip portion of the backflow pipe 7 is fitted into the mounting hole 504. Has been done.

Further, a delivery pipe 44 is connected and attached to the upper end of the discharge joint 6 by a connector 41, and a tip nozzle 144 of the delivery pipe 44 is guided to the inside of the combustion burner chamber 52, for example, near the center. This combustion burner 52 is a normal burner that ignites with an igniter, and the fuel guided inside is vaporized inside under high temperature, and from a large number of small holes (not shown) formed on the upper peripheral surface. It is designed to be burned when it is released. As can be seen from FIG. 1, the position of the tip (lower end) 72 of the backflow pipe 7 is set lower than the position of the tip nozzle 144 of the delivery pipe 44.

Here, when the excitation by the pulse current of the electromagnetic coil 4 is stopped, that is, the driving is stopped, fuel delivery from the inside of the base tank 50 to the tip nozzle 144 via the cylinder 2 and the delivery pipe 44 is stopped until then. The fuel remaining in the nozzle 144 portion expands due to the high temperature in the combustion burner chamber 52 and tries to drip from the nozzle 144. At this time, since the tip (lower end) 72 of the backflow pipe 7 is set at a lower position than the tip nozzle 144, the fuel remaining in the delivery pipe 44 flows into the backflow pipe 7 according to the siphon principle. It is collected from the tip 72 into the base tank 50. Therefore, the residual fuel that was about to be dropped from the front end nozzle 144 is effectively removed by backflow to the backflow pipe 7 without dropping. The backflow velocity at this time is proportional to the vertical distance between the tip nozzle 144 and the tip (lower end) 72 of the backflow tube 7. By setting this distance appropriately, a suitable backflow velocity can be obtained. Becomes Further, since the tip 72 has a larger diameter than the small diameter of the backflow constriction 63, the backflow pressure is large, and effective backflow removal can be realized.

On the other hand, during driving, part of the discharged fuel is diverted to the backflow pipe 7, and this diverted fuel is collected in the base tank 50.

The position of the tip 72 of the backflow pipe 7 may be any position as long as it is lower than the tip nozzle 144, and the tip 72 may be guided to, for example, a collecting part or a containing part other than the base tank 50. Further, the suction pipe 5 and the discharge joint 6 may be integrated with the structure of the cylinder 2. Furthermore, although the present invention has been described with reference to an example applied to an oil combustor, the present invention is not limited to this and can be applied to an electromagnetic pump that guides fluid to a member on the downstream side.

Next, using the configuration diagrams of FIGS. 5 to 10 which are simplified versions of FIG. 1, the position of the tip nozzle 144 and the tip (lower end) 72 of the backflow pipe 7 in the vertical direction, and other implementations regarding the structure are performed. An example will be described. In each of the following drawings, L ₀ is the height of the oil surface 502 in the base tank 50, L ₁ is the height of the tip (lower end) 72 of the backflow pipe 7, the position of the tip nozzle 144 is the base of the delivery pipe 44, and lowest position of the tip position the delivery pipe 44 of the position 'a liquid guiding member 73 of the position of the end backflow tube 7 of the tip (lower end) 72 is a delivery tube 44, matching the first height L ₁ from the position The position is the delivery pipe 44, and is the highest position higher than the position between the positions.

FIG. 5 shows a configuration in which the position is lower than the height L ₀ (the tip (lower end) 72 of the backflow pipe 7 is immersed in the oil) and the position is set to the height L ₀ or more. There is. In such a configuration, when the driving of the electromagnetic coil 4 is stopped, the position is set higher than the height L ₀ , so that the fuel remaining in the delivery pipe 44 is backflow pipe 7 by the principle of siphon. The flow of water into the discharge pipe 44 and the dropping from the tip nozzle 144 of the delivery pipe 44 can prevent the generation of an offensive odor. In this embodiment, the entire fuel in the delivery pipe 44 and the backflow pipe 7 shown in FIG. 1 is drained (however, it remains in the backflow pipe 7 between the height L ₀ and the position), but the backflow pipe 7 is removed. Since the tip 72 of the head is immersed in the fuel, it is possible to prevent generation of a dropping sound when dropping from the tip 72 onto the oil surface, as compared with the configuration shown in FIG.

In FIG. 6, the position is higher than the height L ₀ (the tip (lower end) 72 of the backflow pipe 7 is higher than the oil level 502) and the position is set to the height L ₁ or lower. Is shown. In this configuration, when the driving of the electromagnetic coil 4 is stopped, the position is set lower than the position, so that the fuel remaining in the delivery pipe 44 begins to flow into the backflow pipe 7 by the siphon principle. It is possible to prevent dripping from the tip nozzle 144 of the delivery pipe 44 or generation of an offensive odor associated therewith. On the other hand, when the fuel in the delivery pipe 44 flows backward and drops to the position, the height becomes the same as the position, and the backflow is stopped. That is, in this embodiment, the fuel is drained only from a part (position-) on the distal end side of the delivery pipe 44, and the fuel still remains between the positions-. Therefore, the delivery pipe shown in FIG. As compared with the case where the fuel in the entire 44 and the backflow pipe 7 is drained, the rise of combustion at the time of re-driving becomes faster. Further, as described above, even if the fuel in the vicinity of the tip nozzle 144 is simply withdrawn, tar formation of kerosene or the like at the tip nozzle 144 under high temperature can be suppressed, so that tar does not adhere to the inner wall of the delivery pipe 44. Therefore, the smooth supply of fuel can be secured for a long time.

FIG. 7 shows a configuration in which the position is lower than the height L ₀ (the tip (lower end) 72 of the backflow pipe 7 is immersed in the fuel), and the position is set to the height L ₀ or lower. ing. In such a configuration, when the driving of the electromagnetic coil 4 is stopped, the position is set higher than the height L ₀ , so that the fuel remaining in the delivery pipe 44 is backflow pipe 7 by the principle of siphon. It begins to flow into the discharge pipe 44, and it is possible to prevent the generation of a drip from the tip nozzle 144 of the delivery pipe 44 or the accompanying generation of an offensive odor. On the other hand, when the fuel in the delivery pipe 44 flows backward and drops to the position, the height becomes the same as the height L _0, and the backflow stops. That is, in this embodiment, the fuel is drained only from a part (position ~) on the distal end side of the delivery pipe 44, and the fuel still remains between the positions ~, so that the configuration similar to that shown in Fig. 6 is obtained. Have an effect. Further, since the fuel remains between the positions, it is possible to prevent the occurrence of combustion abnormality at the time of re-driving due to the inclusion of air from the tip 72 of the backflow pipe 7. In addition, since the fuel remains between the positions, the siphon effect when the driving is stopped next can be surely exerted.

FIG. 8 is basically the same as the configuration of FIG. 7 and shows a configuration in which a position higher than the position is provided between the positions so as to form a loop between the positions. The flow of fuel due to the driving stop of the electromagnetic coil 4 is similar to that in the case of FIG. , And has the same effect as in FIG. In this configuration, since the position moves upward from the position, the backflow velocity at the time of starting the fuel backflow can be set relatively slowly.

Next, FIGS. 9 and 10 will be described. 9 and 10 are modifications of FIG. 6, and the basic operation is the same as that of FIG.

In FIG. 9, a hole is formed at the position of the backflow pipe 7 (height L ₁ ), the position of this hole corresponds to the tip 72 of the backflow passage 7, and below the hole. A liquid guide member 73 for extending the fuel to the oil surface 502 is extended. The position is higher than the height L ₀ (the tip (lower end) 72 of the backflow pipe 7 is higher than the oil surface 502), and the position is set to the height L ₁ or lower.

Further, the position is set at a position at least higher than the position, and the siphon principle works between the positions. The position ', which is the lower end of the liquid guide member 73, is immersed in the fuel. In this configuration, when the driving of the electromagnetic coil 4 is stopped, the position is set lower than the position, so that the fuel remaining in the delivery pipe 44 begins to flow into the backflow pipe 7 by the siphon principle. It is possible to prevent dripping from the tip nozzle 144 of the delivery pipe 44 or generation of an offensive odor associated therewith. On the other hand, when the fuel in the delivery pipe 44 flows backward and drops to the position, the height becomes the same as the position, and the backflow is stopped. In this embodiment, the fuel is drained only from a part (position ~) on the distal end side of the delivery pipe 44, and the fuel still remains between the positions ~, so that it has the same advantages as those in Fig. 6. Further, since the positions 1 to 'of the liquid guide member 73 are used as a member for guiding the dropping of the fuel, it is possible to prevent the drop noise at the dropping. The liquid guide member 73 may have a structure in which a linear object or the like is connected instead of the extended structure.

In FIG. 10, the liquid guide member 73 is extended to the lower end 72 of the backflow pipe 7, and the liquid guide member, that is, the position to the portion is formed to have a larger diameter than the diameter of the backflow pipe 7. The siphon principle works between the positions ~, and the positions ~ 'are used as members for guiding the fuel dripping. The lower end position 'of the liquid guide member 73 is set to be slightly above the oil level 502. With such a configuration, the same effect as in the case of FIG. 9 can be obtained.

[0052]

[Effect of device]

 As described above, according to the present invention, the backflow passage is provided by branching from the delivery passage formed on the downstream side of the check valve, and the tip of the backflow passage is set at a position lower than the tip of the delivery passage. Therefore, with a simple structure, the fluid in the delivery passage can be backflowed to the backflow passage immediately after the driving of the electromagnetic pump is stopped, and the fluid can be prevented from dripping from the tip of the delivery passage.

Further, since the fluid in the cylinder is not affected, the fluid can be supplied immediately at the start of the next driving, and the generation of abnormal noise can be prevented.

According to the second and fifth aspects of the invention, since the liquid in the distal end portion of the delivery passage is drained, the rise of the combustion operation etc. at the time of restart is accelerated.

According to the third aspect of the invention, the backflow fluid can be effectively collected in the tank.

According to the invention of claim 6, the delivery efficiency of the electromagnetic pump is not significantly impaired.

According to the fourth and seventh aspects of the invention, the liquid collected in the tank falls along the backflow pipe or the liquid guide member, so that the dropping noise can be prevented.

[Submission date] October 22, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

In order to solve such a problem, a check valve built in a plunger is formed of a flexible elastic body, and a leak hole is formed in a part of the check valve. Which is made to flow back into the cylinder to be returned to the tank side (Japanese Utility Model Laid-Open No. 61-147375). Also, a suction pump is provided in communication downstream of the delivery pump, and after the driving is stopped, this suction pump is It has been proposed to operate so as to suck and remove the fuel remaining in the delivery pipe (Japanese Utility Model Laid-Open No. 2-85236).

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

According to the invention of claim 4, the tip position or these delivery passageway, the liquid to a position equal to the height of the liquid surface so that the back flow.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

[0030] At the time of forward movement, and sends pressurized lower flow side of the fluid cylinder 2 closes the intake check valve 12, from the discharge check valve 15 forcibly opened to the discharge port 17 to the downstream side. On the other hand, when returning, the discharge check valve 15 is closed to prevent the fluid on the downstream side of the discharge check valve 15 from returning to the upstream side, and the suction check valve 12 is opened to open the suction port. The fluid is sucked from 16 to the downstream side of the suction check valve 12 . Then, by repeating such forward and backward movements, the fluid is constantly sucked from the suction port 16 and discharged from the discharge port 17. The electromagnetic coil 4 may be supplied with an alternating current of a predetermined cycle.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Correction content]

[0035] The electromagnetic pump 1B are those which communicates with delivery pipe 40 on the lower stream side screwed with connecting means 41 which screws into the inner periphery is screwed to the discharge catch 6 which screw is screwed into the upper outer peripheral Is. As shown in FIG. 1, the delivery pipe 40 has a required length and its tip nozzle is guided to the combustion burner chamber.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0040

[Correction method] Change

[Correction content]

Here, when the excitation by the pulse current of the electromagnetic coil 4 is stopped, that is, the driving is stopped, fuel delivery from the inside of the base tank 50 to the tip nozzle 144 via the cylinder 2 and the delivery pipe 44 is stopped until then. The fuel remaining in the nozzle 144 portion expands due to the high temperature in the combustion burner chamber 52 and tries to drip from the nozzle 144. At this time, since the tip (lower end) 72 of the backflow pipe 7 is set at a lower position than the tip nozzle 144, the fuel remaining in the delivery pipe 44 flows into the backflow pipe 7 according to the siphon principle. It is collected from the tip 72 into the base tank 50. Therefore, the residual fuel that was about to be dropped from the front end nozzle 144 is effectively removed by backflow to the backflow pipe 7 without dropping. The backflow velocity at this time is proportional to the vertical distance between the tip nozzle 144 and the tip (lower end) 72 of the backflow tube 7. By setting this distance appropriately, a suitable backflow velocity can be obtained. Becomes Moreover, since the backflow pipe 7 has a larger diameter than the small diameter of the backflow constriction portion 63, the backflow pressure is large and effective backflow removal can be realized.

[Brief description of drawings]

FIG. 1 is a schematic layout diagram showing a layout relationship between an electromagnetic pump and peripheral members thereof when the electromagnetic pump according to the present invention is applied to an oil combustor.

FIG. 2 is a sectional view showing a first embodiment of a pump according to the present invention.

FIG. 3 is a sectional view showing a second embodiment of a pump in which the present invention is implemented.

FIG. 4 is a sectional view showing a third embodiment of a pump in which the present invention is implemented.

FIG. 5 is a schematic view showing another embodiment regarding the positions of the tip nozzle and the tip of the backflow tube in the vertical direction.

FIG. 6 is a schematic view showing still another embodiment regarding the positions of the tip nozzle and the tip of the backflow tube in the vertical direction.

FIG. 7 is a schematic view showing still another embodiment regarding the positions of the tip nozzle and the tip of the backflow tube in the vertical direction.

FIG. 8 is a schematic view showing still another embodiment regarding the positions of the tip nozzle and the tip of the backflow tube in the vertical direction.

FIG. 9 is a schematic view showing another embodiment of the structure of the tip portion of the backflow tube.

FIG. 10 is a schematic view showing still another embodiment regarding the structure of the tip portion of the backflow tube.

[Explanation of symbols]

 1 Electromagnetic Pump 2 Cylinder 3 Plunger 4 Electromagnetic Coil 5 Suction Pipe 6 Discharge Joint 62 Discharge Constriction Part 63, 43 Backflow Constriction Part 7, 7'Reverse Flow Pipe (Backflow Path) 72 Tip (Lower End) 73 Liquid Guide Member 15 Discharge Check valve 40,44 Delivery pipe (delivery passage) 144 Tip nozzle

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Yasuhito Seki 2-7-15 Kita-Kameicho, Yao-shi, Osaka Prefecture SILVER CO., LTD. (72) Hideichi Hiramatsu 2-Chome, Kita-Kamei-cho, Yao-shi, Osaka No. 15 Silver Co., Ltd.

Claims (7)

[Scope of utility model registration request] 1. A plunger that reciprocates in a cylinder by exciting an electromagnetic coil, and a check valve that opens and closes in synchronism with the reciprocating motion of the plunger and opens fluid sucked from an upstream tank in a downstream direction. In an electromagnetic pump configured on the downstream side of the check valve and having a delivery passage for guiding the delivery fluid to the downstream side and delivering the delivery fluid from the tip, a backflow passage is provided branching from the delivery passage. An electromagnetic pump, wherein the tip is set at a position lower than the tip of the delivery passage. 2. The electromagnetic pump according to claim 1, wherein the delivery passage has a portion having a height equal to or less than a height of a tip of the backflow passage. 3. The electromagnetic pump according to claim 1, wherein a tip end of the backflow passage is immersed in the upper portion of the tank. 4. The electromagnetic pump according to claim 1, wherein a tip of the backflow passage is arranged below a liquid surface position in the tank. 5. The electromagnetic pump according to claim 4, wherein the delivery passage has a portion having a height equal to or lower than a height of a liquid level in the tank. 6. The backflow passage is provided in a part of the passage,
The electromagnetic pump according to claim 1, wherein a narrowed portion having an inner diameter smaller than that of the discharge narrowed portion formed in the delivery passage is formed. 7. The electromagnetic pump according to claim 1, wherein a liquid guide member is provided from the tip of the backflow passage to the liquid level in the tank.