JP2997996B2 - Electromagnetic pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic pump, and more particularly to an electromagnetic pump having a shut-off valve to stop fluid discharge when the pump stops.

[0002]

2. Description of the Related Art An electromagnetic pump uses an intermittent magnetic force generated in an electromagnetic coil by an intermittent current to reciprocate a piston, and performs a pumping operation in cooperation between a suction valve and a discharge valve to pump fluid. The liquid is sucked through the suction hole, pressurized and discharged from the discharge hole. In such a conventional electromagnetic pump,
Although an electromagnetic valve was provided after the discharge hole to prevent the outflow of fluid at the same time as the pump stopped, there was a drawback that the structure became large due to the two parts. Japanese Patent Publication No. 52-38243), which is currently used and has become the mainstream of electromagnetic pumps.

[0003] Such an electromagnetic pump with a built-in electromagnetic valve is
Widely used for oil burners in combustion equipment such as hot water supply and heating. In recent years, with the progress of burner combustion technology, equipment that adopts a mild ignition method for silencing in the early stage of combustion and reduction of pollutant exhaust gas has become mainstream. I came.

One type is called a mechanical type, and a pump discharge pressure soft start type incorporating a combined function of volume and orifice leakage in an electromagnetic pump body, for example, JP-A-59-7787 (Electromagnetic pump having pressure rise time adjusting device) ), Japanese Utility Model Application Laid-Open No. Sho 62-14173 (Pressure Rise Time Adjustment Device for Electromagnetic Pump) and Japanese Utility Model Application Laid-Open No. Sho 62-184180 (Electromagnetic Pump Rise Time Adjustment Device).

The other is called an electric type, and the above-mentioned electromagnetic pump is used to adjust the duty ratio of a pulse current applied to the pump by using a control circuit to electrically softly start the discharge pressure of the pump. Things.

[0006] Both soft-start technologies have their respective features, but the common feature of both systems is that when the electromagnetic pump is stopped, the discharge hole is closed by an electromagnetic valve built into the electromagnetic pump. High pressure inside pump (eg 7kg / cm
⁽² ) each has a pressure release means.

In the mechanical soft-starting technique, a plunger for giving a change in volume has an orifice, and a pressure before and after the plunger and a return spring are opened by a return spring to release the residual pressure to the suction side.

[0008] In the electric soft start technology, for example,
As shown in 8-82481 (residual pressure eliminating device for pump), a slight leakage groove is provided in advance in the relief valve of the electromagnetic pump, and Japanese Utility Model Laid-Open No. 1-166777 (relief valve for eliminating residual pressure in electromagnetic pump). As shown in (2), an orifice is provided between the inside of the pump and the suction path, and the system always leaks to the suction path side even during operation of the pump.

[0009]

Since the dedicated leak path and orifice have one effective opening area, dust and the like are likely to be clogged, a strainer (filter) is usually provided immediately before or immediately before. However, the frequency of the on / off control of the electromagnetic pump has been designed and supported with the standard of about 200,000 times.
Beyond this, repeated operation of 1 million times or more is practically necessary, and the clogging becomes severe due to the fine abrasion powder of the internal movable part of the electromagnetic pump itself, and the internal pressure can not be released. Had occurred.

It is an object of the present invention to provide an electromagnetic pump having a means for quickly discharging the internal pressure of the pump when the pump stops.

[0011]

In order to achieve the above-mentioned object, an electromagnetic pump according to the present invention comprises an electromagnetic plunger which is reciprocated by the application of an intermittent current to an electromagnetic coil, and an electromagnetic plunger interlocked with the electromagnetic plunger. A piston that reciprocates, a suction valve and a discharge valve that act as a pump in cooperation with the piston, and a shutoff valve that closes a discharge hole when the electromagnetic pump is stopped. the pump chamber defining a portion, bypassing the suction valve forming a leak passage connecting the upstream intake Iriben, the Li
The work passage is formed between the outer periphery of the valve seat of the suction valve and a member covering the valve seat.
The gap between the ring-shaped openings formed between them
There (claim 1). Further, the electromagnetic pump according to the present invention
Is the reciprocating motion of the electromagnetic coil
And the magnetic plunger, cylinder in conjunction with the electromagnetic-flops plunger
The piston is reciprocated in the damper, and in cooperation with this piston
Suction and discharge valves that act as pumps and stop the electromagnetic pump
An electromagnetic pump equipped with a shut-off valve that closes the discharge port
Pump chamber, wherein the tip of the piston defines a part
Are connected around the suction valve and upstream of the suction valve.
A leak passage is formed, and this leak passage constitutes a valve seat of the suction valve.
A ring-shaped opening formed between the valve seat body and the valve seat body
( Claim 2). Further, a pressure rise time adjusting device is added to the configuration of the invention described in claims 1 and 2 (claim 3).

Accordingly, in the invention of claim 1 and 2 wherein, when the pump is stopped, the pump inner pressure piston and the cylinder and the gap enters through the pump chamber of, wheels therefrom
The gas is discharged to the upstream side from the suction valve through a leak passage formed by an opening gap . That is, the pump internal pressure can be reduced within a predetermined time. In addition, when the pump is driven , the fluid is in contact with the wall of the fluid in the leak passage formed by the annular opening gap.
Since the area is large, the kinematic viscosity resistance is large, and the amount of escape from the pump chamber at that time can be reduced.

According to a third aspect of the present invention, there is provided an electromagnetic pump in which a mechanical type pressure rise time adjusting device is added, and the pressure rise is moderated due to a volume change occurring at an early stage of the pump driving, and the pump is stopped when the pump is stopped. The internal pressure is discharged from the gap between the piston and the cylinder, the pump chamber, and the leak passage, so that the added pressure rise time adjusting device can function. This pressure rise time adjusting device does not need to provide a leak hole in the pressure adjusting piston that moves only by a change in volume.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2, the electromagnetic pump 1 has an electromagnetic coil 2 to which an intermittent current (pulse current) is applied in a case 4 formed of a magnetic material such as iron. The electromagnetic coil 2 is formed by winding an electric wire around a bobbin 3 made of resin. A through-hole formed through the center of the bobbin 3 has a guide pipe 5 made of a non-magnetic material made of metal. Is inserted. The upper plate 6 and the lower plate 7 are arranged at the upper end and the lower end of the bobbin 3, and constitute a magnetic circuit together with the case 4.

Above the guide pipe 5, a magnetic rod 8 is disposed.
It is fitted into the pump body 10 via the ring 9. The magnetic rod 8 is formed of a magnetic material such as iron. A substantially lower half of the magnetic rod 8 is inserted into the guide pipe 5 via an O-ring 11, and an upper half of the magnetic rod 8 is an O-ring. 12, a body portion 58 of the discharge joint 56 described below.
, And a hole 13 penetrates the inside in the vertical direction.

The electromagnetic plunger 15 is formed in a substantially cylindrical shape by a magnetic material such as iron.
6 and the lower spring 17, the guide pipe 5
It is slidably supported in an electromagnetic plunger working chamber 19 formed therein. The electromagnetic plunger working chamber 19 is moved by the electromagnetic plunger 15 into an upper spring chamber 19a.
And a lower spring chamber 19b. A vertical hole 20 is formed in the electromagnetic plunger 15 in the axial direction, and communicates the upper spring chamber 19a and the lower spring chamber 19b. In addition, below the electromagnetic plunger 15,
The piston 21 is fixed.

The piston 21 is inserted into a cylindrical cylinder 24 inserted through a hole formed in the pump body 10 via an O-ring 23, and the electromagnetic plunger 15
Reciprocates with the reciprocating motion of. The cylinder 24 is inserted into a hole 22 communicating with the electromagnetic plunger working chamber 19 formed in the pump body 10, and a flange 25 formed on the outer periphery in the middle is engaged with the pump body 10 via an O-ring 23. Have been. The flange 25 also functions to support the lower end of the lower spring 17.

The pump chamber 27 includes a pump body 10, a tip of the piston 21, and a suction valve 28 and a discharge valve 29 described below.
The volume is changed by the reciprocating motion of the piston 21 in the space defined by the suction valve 28 and the discharge valve 2.
9 to perform a pump action. More specifically, when the piston 21 rises and the volume of the pump chamber 27 increases, and the inside of the pump chamber 27 becomes negative pressure, the suction valve 28 opens and sucks fluid (fuel) from the suction hole 30. Is lowered to reduce the volume of the pump chamber 27, and when the pump chamber 27 becomes a positive pressure, the discharge valve 29 is opened to discharge the fuel.

The suction valve 28 and the discharge valve 29 are connected to a valve seat 28a.
And 29a are connected to each other, and a lid 31 is fitted to the discharge-side valve seat body 29a to be disposed in an integrated suction / discharge valve capsule 32. The suction / discharge valve capsule 32 is attached to the pump body 10 And is screwed into the hole 33 formed therein. The flow path between the suction valve 28 and the discharge valve 29 communicates with the pump chamber 27. 28b and 29b are springs. Note that the flow path after the discharge valve 29 is
Through the hole 35 formed in the electromagnetic plunger working chamber 19.

The leak passage 36 is provided around a valve seat body 28c (which constitutes a valve seat with the valve seat body 28a) attached to the valve seat body 28a, and more specifically, the diameter of the valve seat body 28c. Is formed to be smaller than the hole of the valve seat body 28a into which is inserted, and has an annular groove 28d formed on the outer periphery and a diametric hole 28e communicating with the annular groove 28d and connected to the vertical hole 28f. Between the valve seat body 28c and the hole of the valve seat body 28a.
The gap between the annular openings is about several tens of microns, and the leakage passage 36
When the pump is driven (the direction of flow fluctuates 50 to 60 times per minute), the contact area of the fluid wall is large.
Because of the size, the kinematic viscosity resistance of the fluid is large, and the amount flowing out of the pump chamber 27 is small. When the pump is stopped, there is no change in the direction of the flow of the fluid, and the flow is in one direction.
Outflow of internal pressure is fast (around 2 seconds).

The discharge joint 56 has a body 57 and a body 58 connected to the body 57. The body 58 is inserted into the bobbin 3 as described above, and the upper part of the magnetic rod 8 is inserted. is there. In the body 58, a solenoid valve storage chamber 59 is provided.
Is formed in the solenoid valve storage chamber 59.
0 is housed and is pressed by the spring 61 to close the discharge hole 62 (when not energized). When energized, the discharge hole 62 is pulled toward the magnetic rod 8 against the spring 61.
Is to be opened.

In the electromagnetic pump 1 as described above, when a pulse current having a predetermined pulse number (50 to 60 times) is applied and the electromagnetic coil 2 is excited, a magnetic force is generated in the magnetic rod 8 and an electromagnetic plunger is generated. 15 is sucked against the upper spring 16, so that repulsive energy is stored in the upper spring 16. Then, when the electromagnetic coil 2 is demagnetized, the coercive force disappears and is returned downward by the repulsive energy of the upper spring 16. Such repetition causes the electromagnetic plunger 15 to reciprocate. The electromagnetic pump 1 is of a soft start type having a gradual rise at the time of startup, and employs a known technique which is performed by changing a duty ratio of a pulse.

The reciprocation of the electromagnetic plunger 15 is as follows.
It is transmitted to the piston 21 and reciprocated in the cylinder 24. When the piston 21 reciprocates, that is, is displaced downward, the volume of the pump chamber 27 increases, and a negative pressure is created to open the suction valve 28 and suck the fluid from the suction hole 30. When the pump chamber 27 is displaced upward, the volume of the pump chamber 27 is reduced, and the pressure becomes a positive pressure, so that the discharge valve 29 is opened to discharge the fluid into the electromagnetic plunger working chamber 19. In addition, there is a pressure fluctuation of 50 to 60 times per minute when the pump is driven,
As a result, the flow direction also fluctuates, so that the kinematic viscous resistance of the leak passage 36 is large and the leak amount is small.

The fluid discharged from the discharge valve and flowing into the electromagnetic plunger working chamber 19 is smoothed by an accumulator (not shown), adjusted to a predetermined pressure by a relief valve (not shown), and opened through an electromagnetic valve 60 which is opened. It is sent out to the external device through the discharge hole 62.

When the application of the pulse current to the electromagnetic coil 2 is interrupted, the reciprocation of the electromagnetic plunger and the piston 21 is stopped, and at the same time, the electromagnetic valve 60 is seated on the valve seat and the discharge hole 6 is stopped.
2 is closed. That is, a high-pressure (for example, 7 kg / cm ² ) fluid is confined between the suction valve 28 inside the pump and the electromagnetic valve 60, particularly in the electromagnetic plunger working chamber 19. The high-pressure fluid flows between the piston 21 and the cylinder 2
4 to the pump chamber 27 and then through the leak passage 36 to flow upstream from the suction valve, allowing the internal pressure to flow to the suction side. In other words, the piston 21 serving as a leak path is a movable member, and performs an automatic cleaning action in which dust is less likely to adhere, thereby improving reliability.

The outflow time is about 2 to 3 seconds, and can be controlled by appropriately adjusting the clearance between the piston 21 and the cylinder 24, the sectional area of the leak passage 36, and the length of the cylinder 24. Therefore, when the internal pressure decreases in about 2 to 3 seconds after the pump stops, and the pump is driven again, the discharge pressure changes gradually by changing the duty ratio of the pulse current applied to the electromagnetic coil 2 and becomes steady. Pressure and can contribute to mild ignition in oil-fired equipment.

Although an example is shown in which the shut-off valve is a solenoid valve 60 which is opened and closed by the magnetic attraction of the magnetic rod 8, a solenoid valve having an independent solenoid coil for the solenoid valve, and a solenoid valve having a solenoid coil for the solenoid valve may be used.
The technology disclosed in Japanese Patent Application Laid-Open No. 21583 and Japanese Utility Model Publication No. 61-14635, that is, a valve that closes from a change in the position of the electromagnetic plunger when the pump is stopped may be used.

In FIG. 3, unlike the above-described embodiment, a mechanical pressure rise time adjusting device 64 for soft ignition is used.
It is shown. The pressure rise time adjustment device 64 includes a pressure rise time adjustment cylinder (hereinafter, referred to as a pressure adjustment cylinder) 66 inserted into a hole 65 formed in the pump body 10, and a pressure adjustment piston sliding in the pressure adjustment cylinder 66. 67
And a spring 68 pressing the pressure adjusting piston 67.
The pressure adjusting cylinder 66 has a partition wall 6
9 before and after the front room 70a and the rear room 70b, respectively.
Is formed. A through hole 71 is formed in the partition wall 69 to communicate the two chambers 70a and 70b.

A filter 72 is housed in the front chamber 70a, and communicates from a hole 74 formed in the pressure adjusting cylinder 66 to a downstream side of the discharge valve 29 through a communication hole 73. A pressure adjusting piston 67 is slidably disposed in the rear chamber 70b and is urged by a spring 67. The pressure adjusting piston 67 is opposed to the pressure downstream of the discharge valve. 7
Reference numeral 5 denotes a stopper on which a spacer for adjusting a stroke can be arranged. The pressure adjusting cylinder 66 and the filter 72 are pressed by the mounting plate 36 on which the accumulator 47 is mounted, and mounted on the pump body 10.
The pressure adjusting piston 67 is not formed with a leak hole or the like.

Such a pressure rise time adjusting device 64
When pump driving is started, fluid downstream of the discharge valve 29, that is, high pressure is supplied through the communication hole 73, first enters the front chamber 70a, and then through the communication hole 71, the pressure adjusting piston 6
Apply pressure to 7. The pressure adjusting piston 67 starts displacing when a predetermined pressure ( ^{2 to 3} kg / cm ² ) is reached, and the front chamber 70a
When the volume is increased to, for example, 5-6 kg / cm ² ,
It acts to stop the expansion of the volume and moderates the rise in pressure at the beginning of driving. In the pressure rise time adjusting device 64 having this configuration, when the pump is stopped, the pump internal pressure flows out through the gap between the piston 21 and the cylinder 24, the pump chamber 27 and the leak passage 36, as described above. Since the pressure can be reduced to a value close to the atmospheric pressure in about 2 to 3 seconds, the piston 67 is returned by the spring 68 and can be softly started again when the pump is restarted. Other parts are the same as the above-described embodiment,
The same portions are denoted by the same reference numerals and description thereof is omitted.

FIGS. 4 and 5 show a second embodiment of the present invention, in which a discharge valve 80 is provided in a piston 79 which is connected to the electromagnetic plunger 15 and slides in a cylinder 78. The present invention can be applied to an electromagnetic pump having a structure in which a suction valve 82 is provided in 78.

That is, the piston 79 is connected to the electromagnetic plunger 1
5 and slides together.
A vertical hole 83 is formed therein, and a discharge valve 80 is provided above the vertical hole 83, and is urged by a spring 84. The piston 79 is slidably disposed in a cylinder 78 described below.

The cylinder 78 is relatively long and is inserted into a hole 22a formed in the pump
5 is locked to the main body 10 via an O-ring 86.
The flange 85 also functions to support the lower end of the lower spring 17. Below the cylinder 78, the piston 79 does not reach but a suction valve 82 is provided.

The suction valve 82 is arranged together with the valve seat body 82c of the intake valve in the cylinder 78, and is biased by a spring 82 b, seated on the valve seat body 82c. The space between the suction valve 82 and the discharge valve 80 is a pump chamber 87.
It has become.

The leak passage 89 is provided around the valve seat 82c of the suction valve attached to the cylinder 78. Specifically, the diameter of the valve seat 82c is made smaller than that of the cylinder 78 into which the valve is inserted, and formed on the outer periphery. annular grooves 82d and communicating with the annular groove 82d, the diameter direction of the connection to the vertical hole 82 f hole 8
2e. The gap of the annular opening of the leak passage 89 is about several tens of microns, and since the leak passage 89 is long, when the pump is driven (the flow direction fluctuates 50 to 60 times per minute), the wall surface of the fluid Since the contact area is large , the kinematic viscosity of the fluid is large, and the amount flowing out of the pump chamber 87 is small. When the pump is stopped, there is no variation from the direction of the flow of the fluid, the flow is in one direction, the passage resistance is small, and the internal pressure flows out quickly (around 2 seconds). Although the second embodiment has been described above, the same portions as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

Also in the second embodiment described above, when a pulse current having a predetermined number of pulses (50 to 60 times) is applied and the electromagnetic coil 2 is excited, a magnetic force is generated on the magnetic rod 8. As a result, the electromagnetic plunger 15 is sucked against the upper spring 16, whereby repulsive energy is stored in the upper spring 16. Then, when the electromagnetic coil 2 is demagnetized, the coercive force disappears and is returned downward by the repulsive energy of the upper spring 16. Such repetition causes the electromagnetic plunger 15 to reciprocate. The electromagnetic pump 1 is of a soft start type having a gradual rise at the time of startup, and employs a known technique which is performed by changing a duty ratio of a pulse.

The reciprocating motion of the electromagnetic plunger 15 is as follows.
It is transmitted to the piston 79 and reciprocated in the cylinder 24. When the piston 79 is reciprocated, that is, displaced downward, the volume of the pump chamber 87 is increased, so that a negative pressure is created, the suction valve 82 is opened, and the fluid is sucked from the suction hole 30. When the pump chamber 87 is displaced upward, the volume of the pump chamber 87 is reduced, so that the pressure becomes a compression pressure (positive pressure), and the discharge valve 80 is opened to discharge the fluid into the electromagnetic plunger working chamber 19. Since the pressure in the leak passage 89 fluctuates 50 to 60 times per minute when the pump is driven, the flow direction also fluctuates. Therefore, the kinematic viscous resistance of the leak passage 89 is large and the leakage amount is small.

The fluid discharged from the discharge valve and flowing into the electromagnetic plunger working chamber 19 is smoothed by an accumulator (not shown), adjusted to a predetermined pressure by a relief valve (not shown), and opened via an electromagnetic valve 60 opened. It is sent out to the external device through the discharge hole 62.

When the application of the pulse current to the electromagnetic coil 2 is cut off, the reciprocation of the electromagnetic plunger and the piston 79 is stopped, and at the same time, the electromagnetic valve 60 is seated on the valve seat and the discharge hole 6 is stopped.
2 is closed. That is, a high-pressure (for example, 7 kg / cm ² ) fluid is confined in the space between the suction valve 82 inside the pump and the electromagnetic valve 60, particularly in the electromagnetic plunger working chamber 19. This high-pressure fluid is supplied to the piston 79 and the cylinder 7
8 to the pump chamber 27, and then through the leak passage 89 to flow upstream from the suction valve, allowing the internal pressure to flow to the suction side. That is, the piston 79 serving as a leakage path is a movable member, and performs an automatic cleaning action in which dust is less likely to adhere, thereby improving reliability.

The outflow time is about 2 to 3 seconds, and can be controlled by appropriately adjusting the clearance between the piston 79 and the cylinder 78 and the cross-sectional area and length of the leak passage 89. Therefore, when the internal pressure decreases in about 2 to 3 seconds after the pump stops, and the pump is driven again, the discharge pressure changes gradually by changing the duty ratio of the pulse current applied to the electromagnetic coil 2 and becomes steady. Pressure and can contribute to mild ignition in oil-fired equipment.

[0041]

As described above, according to the first and second aspects of the present invention, when the pump is stopped, the reciprocation of the fluid stops.
The pressure (high pressure) in the pump can escape to the suction side through the gap between the piston and the cylinder, the pump chamber, and the leak passage, and can reduce the internal pressure of the pump within a predetermined time. Moreover, at the time of the pump drive, the ring-shaped opening
A leak passage consisting of a gap between the mouth and the wall
As the contact area increases, the kinematic viscosity resistance of the leak passage increases, and the amount of escape from the pump chamber can be reduced.

Since the leak passage is formed in the valve seat of the suction valve, the manufacturing is simple. In addition, by changing the length and the sectional area of the leak passage by changing the shape of the valve seat of the suction valve, the control capability (the amount of leak) can be improved. ) Can be varied.

According to the third aspect of the present invention, a mechanical pressure rise time adjusting device is added to the first and second aspects of the present invention. in the electromagnetic pump that gradual increase, the gap between the internal pressure piston and the cylinder of the pump during shutdown, the pump chamber is left discharged from the leak passage, it was possible to operate the added pressure rise time adjustment device Things.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a transverse sectional view of a main part of the above.

FIG. 3 is a sectional view of a main part in an example in which a pressure rise time adjusting device is added to the present invention.

FIG. 4 is a longitudinal sectional view showing another embodiment of the present invention.

FIG. 5 is an enlarged sectional view of a main part of the above.

[Explanation of symbols]

 Reference Signs List 1 electromagnetic pump 2 electromagnetic coil 15 electromagnetic plunger 24, 78 cylinder 28, 82 suction valve 29, 80 discharge valve 36, 89 leak passage 60 electromagnetic valve 64 pressure rise time adjusting device

Claims (3)

(57) [Claims] 1. An electromagnetic plunger reciprocated by the application of an intermittent current to an electromagnetic coil, a piston reciprocated in a cylinder in conjunction with the electromagnetic plunger, and a suction valve cooperating with the piston to act as a pump. And a discharge valve, and a shut-off valve that closes a discharge hole when the electromagnetic pump is stopped, wherein a pump chamber in which a tip of the piston defines a part bypasses the suction valve and is closer to the suction valve than the suction valve. Leak passage connecting upstream
The leak passage is formed around the outer periphery of the valve seat of the suction valve.
Consists of a ring-shaped opening formed between the seat covering member
An electromagnetic pump characterized in that: 2. A reciprocation by applying an intermittent current to an electromagnetic coil.
Moved electromagnetic plunger and linked to this electromagnetic plunger
Piston that reciprocates in the cylinder
Suction and discharge valves, which act as pumps in cooperation with
Electromagnetic with a shut-off valve that closes the discharge hole when the pump stops
In the pump, the pump chamber in which the tip of the piston defines a part is
Leak passage bypassing the suction valve and connecting upstream of the suction valve
And the leak passage forms a valve seat of the suction valve.
It consists of the gap of the ring-shaped opening formed between the seat body and the valve seat.
An electromagnetic pump characterized in that: 3. The electromagnetic pump according to claim 1, further comprising a pressure rise time adjusting device.