JPH0442536Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The invention relates to an electromagnetic free piston pump, and in particular, a piston (free piston) configured to be able to slide only in a predetermined direction with a spring is moved by an electromagnet. This invention relates to an electromagnetic free piston pump that is reciprocated, and the volume within a pressure chamber is changed by the reciprocation to suck in and discharge fluid.

(Prior Art) Conventionally, as a relatively small compression pump, a diaphragm is connected to a movable body having a permanent magnet or a magnetic material, and the movable body is operated using an electromagnetic circuit to move the diaphragm in one place. Some devices are configured to change the volume inside the pressure chamber, which serves as a wall surface, and discharge or suction fluid such as air.

This type of pump (hereinafter referred to as a diaphragm pump) is disclosed in Japanese Patent Application Laid-Open No. 63-65182 and the same.
It is described in 63-176680, 63-227978, etc.

(Problems to be solved by the invention) The diaphragm pump had the following problems.

(1) Each time the movable body reciprocates, the diaphragm flexes, but since this diaphragm is made of a flexible material such as synthetic rubber, it is easily damaged. Therefore, its maintenance is troublesome.

If the diaphragm is made to be highly durable to prevent damage, the desired pressure and flow rate cannot be expected, it becomes expensive, and the structure of the diaphragm support becomes complicated, making it difficult to construct the diaphragm pump. becomes more complex and productivity decreases.

(2) Since the movable body is supported by the diaphragm itself, there is a risk that the movable body may come into contact with the core etc. during operation due to flexure of the diaphragm. This can lead to damage to the diaphragm pump.

The present invention was devised to solve the above-mentioned problems, and its purpose is to provide a pump device that is easy to maintain, has a simple configuration, can be manufactured at low cost, and is highly durable. Our goal is to provide the following.

(Means and effects for solving the problem) In order to solve the above-mentioned problems, the present invention provides a coil having a cylindrical center having an axial center length such that a substantially sealed pressure chamber is formed in both ends of the coil. Shape and
A thin bearing made of a non-magnetic material with low magnetic permeability is disposed on the inner circumference of the coil at least in the stroke range of the piston, and the piston is symmetrically provided with a piston head and a permanent magnet, and The assembly in which the permanent magnets are connected to each other in a hollow state further includes a spring symmetrically arranged on the inner circumference of the coil for returning the piston to the neutral position, and A feature is that a state core is disposed between the central portion and the bearing.

When an alternating current is applied to the coil, the magnet is attracted and repelled by the leakage magnetic flux, and as a result, the piston is always kept aligned with the piston by a cylindrical bearing made of thin material, and moves back and forth, increasing the volume inside the pressure chamber. and fluid is suctioned and discharged from the pressure chamber.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

Fig. 1 is a vertical sectional side view of the embodiment of the present invention with the main parts cut away, Fig. 2 is a sectional view of the left half taken along line A-A in Fig. 1, and Fig. 3 is a flat valve. The plan view and FIG. 4 are front views of the valve seat viewed from direction B in FIG. 1, and in each figure, the same reference numerals represent the same or equivalent parts. In addition, in FIG. 4, the flat valve 2 is shown by an imaginary line. Furthermore, the base 31 shown in FIG. 2 is similar to the vibration isolating rubber 1 shown in FIG.
7, and this base 31 is omitted in FIG.

1 and 2, a cylindrical coil 10 is wound around a thread-shaped bobbin 6 made of resin. The length of the bobbin 6 is formed to be slightly shorter than the stroke range of the piston (described later), that is, the distance of reciprocating movement.

A cylindrical state core 12 made of a magnetic material such as low carbon steel is disposed at the center inside the bobbin 6. In addition, inside the state core 12, a hard glass whose wall thickness is as thin as possible,
A bearing 13 made of stainless steel, brass, or the like is arranged. The cross-sectional shape of this bearing is formed into a cylindrical shape to match the cross-sectional shape of the piston described later, but it does not have to be cylindrical as long as the surface is suitable for slidably supporting the outer peripheral surface of the piston. Not even.

A yoke core 5 made of a magnetic material such as low carbon steel is arranged outside the cylindrical coil 10.

The bobbin 6 and the state core 12 are molded with resin so that their relative positional relationship is fixed (reference numeral 30). This molding part 30 is formed so that the inner wall of the bearing 13 is exposed.

A piston 20 is slidably disposed inside the bearing 13. The piston 20 has a cylindrical piston body 11 made of a non-magnetic material such as resin, carbon, or aluminum in the center, and a pair of front and rear magnetic yokes fixed to both ends of the piston body 11. 7. It is composed of a permanent magnet, that is, a magnet 8, and a rear magnetic yoke 9, and the front magnetic yoke 7 constitutes a piston head.

The front magnetic yoke 7, the magnet 8, and the rear magnetic yoke 9 are made of a magnetic material such as low carbon steel.
is made of, for example, a rare earth element.

Further, the rear magnetic yoke 9 is plate-shaped and is disposed at both ends of the piston body 11 with a required interval. The permanent magnet 8 and the front magnet yoke 7 are arranged on the outer side thereof, and are fixed to both ends of the piston body 11 so as to be in close contact with each other.

Further, the permanent magnets 8, 8 are arranged so that the opposite sides thereof have the same polarity. In the example shown in FIG. 1, each permanent magnet 8 is arranged so that the side facing the rear magnetic yoke 9 is the south pole.

When the cylindrical coil 10 is not energized, the piston 20 is located at the center of the cylindrical coil 10, that is, at the state core 1.
2 (neutral position), and is supported in a balanced manner by a pair of springs 14, which will be described later.

A head cover 1 made of resin or the like is attached to both ends of the cylindrical coil 10 via an O-ring 4, a valve seat 3, and a flat valve 2. This installation requires bolts 16
This is done by screwing the yoke core 5 into a female thread formed in the yoke core 5.

The flat valve 2 is a plate-shaped valve made of a flexible material such as synthetic rubber, and includes a pair of valve bodies (an intake valve 2A and a discharge valve 2B) as shown in FIG. ing.

The valve seat 3 is molded of resin or the like, and, as shown in FIGS. 1 and 4, has a depth that is approximately the same as the thickness of the flat valve 2, and is designed to accommodate the flat valve 2. A first recess 3A formed with a contour (oval shape in this example) that is almost the same as the outer contour of the intake valve 2A, and a first recess 3A formed at a position facing the suction valve 2A.
a second recess 3B formed to be more depressed than the second recess 3B;
A third recess 3C formed to be more depressed than B is provided.

A fluid passage 21 is formed in the portion of the valve seat 3 where the third recess 3C is formed so as not to face the suction valve 2A. Further, a fluid passage 22 is formed in a portion of the valve seat 3 where the first recess 3A is formed and which faces the discharge valve 2B. The fluid passages 21 and 22 pass through the valve seat 3.

The head cover 1 has a suction port 1A at a position facing the suction valve 2A of the flat valve 2, and a discharge valve 2B at a position facing the discharge valve 2B.
A recessed portion 1C larger than the contour is formed.
The recess 1C communicates with the discharge port 1B.

As shown in Figure 1, the flat valve 2
is attached so as to be pressed against the valve seat 3 and head cover 1. and,
Normally, the suction valve 2A is in close contact with the periphery of the suction port 1A formed in the head cover 1, and the discharge valve 2B is in close contact with the fluid passage 2 formed in the valve seat 3.
It is now in close contact with the surrounding area of 2.

The spring 14 disposed between the valve seat 3 and the piston 20 is made of stainless steel wire or the like, and reference numeral 15 designates a spring seat made of a stainless steel plate or the like to receive the spring 14. .

The leg part 18 is formed integrally with the mold part 30 at the lower part of the mold part 30, and a vibration isolating rubber 17 is attached to the bottom part of the leg part 18. The vibration isolating rubber 17 is housed in a base 31 (FIG. 2).

As shown in FIG. 1, by attaching the valve seat 3, a sealed pressure chamber 32 is formed between the valve seat 3 and the piston 20.

In one embodiment of the present invention having the above configuration, when an alternating current such as a commercial alternating current is passed through the cylindrical coil 10, the yoke core 5 and the state core 12
A magnetic circuit is formed by a magnetic flux passing between the two. Here, the ends of the yoke core 5 located at both ends of the cylindrical coil 10 (portions indicated by symbols L and R)
Since no magnetic material is disposed between and both ends of the state core 12 (that is, a non-magnetic region is interposed), leakage magnetic flux occurs. Further, S and N magnetic poles are alternately generated at both ends of the state core 12 .

That is, for example, in one half-wave of alternating current, there is an S pole on the portion L, an N pole on the left end of the state core 12, an S pole on the right end of the state core 12, and an N pole on the portion R.
When a pole occurs, the piston 20 slides to the left in FIG. 1 due to the magnetic action of the magnet 8.

Next, in the other half wave, the magnetic poles of each portion are reversed, so the piston 20 slides to the right in the figure.

Therefore, if the natural frequency of the piston 20 system of the pump is made approximately equal to the frequency of the power supply that energizes the cylindrical coil 10, the piston 20 will reciprocate in a resonant state.

Due to the reciprocating movement of the piston 20, the suction port 1A
Therefore, the suction valve 2A, the third recess 3C, and the fluid passage 2
1, a fluid such as air is introduced into the pressure chamber 32, and the fluid is discharged from the discharge port 1B via the fluid passage 22, the discharge valve 2B, and the recess 1C.

(Modified example) (1) In the pump shown in FIG. 1, pressure chambers 32 are formed on both sides of the piston 20, and the suction port 1A and the discharge port 1B are connected to two pressure chambers 32 so as to communicate with the pressure chambers 32. Although the two sets of suction ports 1A and discharge ports 1B exist independently, the two suction ports 1A are commonly connected, and
The two discharge ports 1B may be connected in common (that is, connected in parallel). Thereby, the discharge port and suction port of the pump are each combined into one.

Also, one discharge port 1B is connected to the other suction port 1A.
It is also possible to connect them in series.

These fluid passages for parallel connection or series connection may be formed within the mold part 30.

An example of such a parallel connection will be described below.

FIG. 5 is a vertical sectional side view of another embodiment of the present invention with main parts cut away, FIG. 6 is a left side view of FIG. 5, FIG. 7 is a right side view of FIG. 5, and FIG. The figure is a cross-sectional view of Figure 5 taken along line C-C, Figure 9 is a cross-sectional view of Figure 6 taken along line D-D, and Figure 10 is a cross-sectional view of Figure 7 taken along line E-E. FIG. In FIG. 7, the flat valve 2, fluid chambers 52A, 52B, fluid passage 53A,
Hidden lines such as 53B are omitted. Also,
In FIGS. 5 to 10, the same reference numerals as in FIGS. 1 to 4 represent the same or equivalent parts, and the explanation thereof will be omitted. In each figure, the reference numeral 55 indicates the cylindrical coil 10 of the electromagnetic free piston pump.
This is the lead wire drawn out from the

In this embodiment, a suction port 1A and a discharge port 1B arranged at both ends of the electromagnetic free piston pump shown in FIG. 1 are connected to a pair of fluid chambers 52A and a pair of fluid chambers 52B, which will be described later. , and each fluid chamber 52A and each fluid chamber 52
B are connected by fluid passages 53A and 53B, which will be described later, and are connected to a common suction port and discharge port (numerals 1A and 1B in FIGS. 5 and 7), respectively.

In FIGS. 5 to 10, reference numeral 52A
and 52B are recesses formed in the head cover 1 disposed on both end sides of the piston 20, and are closed by lids 51, respectively. In FIG. 5, illustration of fluid chambers 52A and 52B located on the right side of the figure is omitted.

Pressure chambers 3 located at both ends of the piston 20
2 is connected to the fluid chamber 52A and fluid chamber 52B via the suction valve 2A and discharge valve 2B of the flat valve 2 in the same manner as described above with respect to FIG.

The pair of fluid chambers 52A and the pair of fluid chambers 5
2B are communicated by a fluid passage 53A and a fluid passage 53B, respectively, and each is further connected to the suction port 1A and the discharge port 1B.

In this way, the suction valve 2A and the discharge valve 2B arranged at both ends of the piston 20 may be communicated with each other through the fluid passages 53A and 53B formed in the mold part 30, respectively.

(2) In FIG. 1, the spring 14 for supporting the piston 20 is provided at both ends of the piston 20, but it may be provided only at one end. In this case, the spring 14 needs to be fixed so as not to separate from the spring seat 15 and the end of the piston 20 (in this example, the front magnetic yoke 7).

(3) In FIG. 1, the magnet 8 is provided at both ends of the piston 20, but it may be provided only at one end.

In this case, since there is no need to provide a non-magnetic region in the core to form a magnetic pole on the side where the magnet 8 is not provided, one end (L portion or R portion) of the yoke core 5 and the end of the state core 12 The parts are connected by a magnetic material. Thereby, energy loss due to leakage magnetic flux can be reduced.

(4) In the piston 20 shown in FIG.
is configured to expose magnetic materials,
In order to prevent the magnet etc. from being exposed, the entire piston 20 may be molded with resin or the like, as indicated by reference numeral 54 in FIG. 5. In this case, rust is prevented from forming on the front magnetic yoke 7, etc., and the piston 20 can always reciprocate well.

(5) The pump described above can be used not only as a compression pump but also as a small vacuum pump.

(Effects of the invention) As is clear from the above explanation, according to the present invention, the following effects are achieved.

(1) Since the piston can reciprocate and the fluid can be sucked and discharged without using a diaphragm, the diaphragm is not damaged and the durability of the pump device is improved.

(2) Since the piston is placed on the inner circumference of the cylindrical coil via a bearing, the piston can always be kept in a centered state and can be slid stably.
The frequency of failure of the pump device is low, and the construction is simple, so production costs can be reduced.

(3) The piston has a symmetrical structure, and springs are applied to both the front and rear ends, so the stroke of the piston is constant. Furthermore, since setting the spring constant of the spring is easier than with a diaphragm pump, stable operation can be expected from beginning to end.

(4) Permanent magnets installed at both ends of the piston,
Since the piston reciprocates, the left compression ratio due to the reciprocating movement of the piston increases, improving the efficiency of the pump device and contributing to miniaturization.

(5) Since the pressure chambers are provided at both ends of the piston, the reciprocating motion of the piston can be efficiently transmitted to the fluid suction and discharge motions, and as a result, the efficiency of the pump device is improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view showing an embodiment of the present invention. FIG. 2 is a sectional view and a side view taken along the line AA in FIG. 1. FIG. 3 is a plan view of the flat valve. FIG. 4 is a view of the valve seat viewed from direction B in FIG. 1. FIG. 5 is a longitudinal sectional side view of another embodiment of the present invention with main parts cut away. FIG. 6 is a left side view of FIG. 5. FIG. 7 is a right side view of FIG. 5. FIG. 8 is a cross-sectional view of FIG. 5 taken along line CC. FIG. 9 is a cross-sectional view of FIG. 6 taken along line DD. Figure 10 shows Figure 7 as E-
It is a sectional view cut along the E line. 1...Head cover, 2...Flat valve,
2A...Suction valve, 2B...Discharge valve, 3...Valve seat, 5...Yoke core, 6...Bobbin, 7...
...Front magnetic yoke, 8...Permanent magnet,
9... Rear magnetic yoke, 10... Cylindrical coil, 11... Piston body, 12... State core, 14... Spring, 20... Piston, 2
1, 22...Fluid passage, 30...Mold part, 3
2...Pressure chamber, 52A, 52B...Fluid chamber, 53
A, 53B...Fluid passage, 54...Mold part.

Claims (1)

[Claims for Utility Model Registration] A cylindrical single-phase coil, a piston body disposed inside the coil so as to be slidable in the direction of the central axis of the coil, and a piston body attached to the inner end surfaces on both sides of the piston body. a piston equipped with a magnet; a sealed pressure chamber configured to change its volume by sliding of the piston; an inlet and an outlet connected to the pressure chamber; the pressure chamber and the inlet In an electromagnetic free piston pump comprising a suction valve and a discharge valve disposed between the coil and the discharge port, the inner periphery of the coil is made of a non-magnetic material with low magnetic permeability at least in the stroke range of the piston. The piston is an assembly including a piston head and a permanent magnet symmetrically, and the left and right permanent magnets are connected in a hollow state, and the inner circumference of the coil is The portion is symmetrically provided with a spring for returning the piston to a neutral position, a state core is disposed between a center portion of the inner periphery of the coil and the bearing, and a yoke core is disposed around the outer periphery of the coil. An electromagnetic free piston pump characterized by: