JPH0645666Y2 - Electromagnetic reciprocating compressor - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to an electromagnetic reciprocating compressor, and more particularly, to a piston top dead center of a compressor which employs a cylinder having a duck's beak-shaped elastic on-off valve as a discharge port. The present invention relates to an electromagnetic reciprocating compressor that improves pump efficiency by approaching a head.

(Prior Art) An example of a conventional electromagnetic reciprocating compressor is disclosed in
50-85815.

In this electromagnetic reciprocating compressor, the cylinder has a discharge port on the wall surface near the head, the discharge port is closed by a disc-shaped elastic opening / closing valve, and the outer peripheral surface of the piston housed inside the cylinder is the cylinder. Uniformly touches the wall surface of the. An armature is provided in which a piston that reciprocates inside the cylinder is biased by a compression spring in the direction of the top dead center and is attracted by the magnetic action of a fixed electromagnetic circuit. Now, when power is supplied to the fixed electromagnetic circuit at a predetermined timing and the field core of the circuit is excited, the armature is attracted to the field core. When the piston reaches the bottom dead center, when the power supply is stopped, the force of the field core to attract the armature disappears, and at this time, the piston receives the force of the spring and returns to the original position. When such an operation is repeated, the piston reciprocates in the cylinder and a predetermined fluid compression action is achieved.

(Problems to be solved by the invention) In the conventional electromagnetic reciprocating compressor described above, the discharge port provided near the cylinder head is closed by a disc-shaped elastic opening / closing valve, but the sealing surface of the discharge valve is high. When the processing accuracy is required and the processing accuracy is poor, there is a problem that the ejection force becomes unstable because the sealing property is impaired.

Therefore, if a duck-shaped beak valve with excellent sealing performance is used instead of this disc-shaped valve, the valve has a larger diameter than that of the disc-shaped valve, and the discharge port is the same as that of the cylinder head. The position of the top dead center of the piston also recedes, and the space between the piston head and the cylinder head at top dead center widens, resulting in pressure loss and the effect of using a duck-shaped beak valve diminishes. There was a problem of being lost.

(Means and Actions for Solving Problems) The feature of the present invention is to improve the sealability of the valve by using a duck-shaped beak-shaped valve as a valve for closing the discharge port provided on the cylinder wall surface. The point is that the output pressure is stabilized.

(Example) Below, this invention is demonstrated based on an Example.

FIG. 1, FIG. 2 and FIG. 3 are views showing an example of a cylinder used in the electromagnetic reciprocating compressor of the present invention,
1 is a perspective view, FIG. 2 (a) is a vertical sectional side view of the cylinder, FIG. 1 (b) is a front side view, and FIG. 3 (a) is a sectional view taken along line AA of FIG. 2 (a). Figure, Figure (b) is BB of Figure 1.
It is a line sectional view.

As is apparent from FIGS. 1 and 2, the cylinder 2 has a rear cylinder 3a, a front cylinder 3b, a piston shaft guide boss 4 and a flange 8 which are integrally structured, and an insulator, preferably a thermal expansion coefficient of which is aluminum. It is formed of a synthetic resin such as polyamide imide which is similar. A piston shaft guide hole 6 is formed in the piston shaft guide boss 4, and a screw hole 10 for a screw 36 (see FIG. 4A) for fixing the field core 38 is formed in the flange 8. .

A flange for fixing a lid 31 (see FIG. 4 (a)) for forming a cylinder head to the open end of the front cylinder 3b.
14 is integrally molded. A discharge port 18 is formed near the cylinder head of the front cylinder 3b.

The cross section of the front cylinder 3b taken along the line A-A in FIG. 2 (a) is a complete circle, and the shape of the outer wall surface is chamfered with a plane parallel to the central axis and symmetrical to the center. There is. Reference numeral 5 denotes a cutout portion that connects the inside and the outside of the rear cylinder 3a in the radial direction.

In addition, in FIG. 1 and FIG. 3 (b), 21 is a discharge port.
There are 18 valve mounting portions, and a duck bill (duck beak-shaped valve 33) is fitted to the mounting portion 21.

Next, FIG. 4 (a) is a vertical side view of the compressor of the present invention, FIG. 4 (b) is its front view, FIG. 4 (c) is a rear view, and FIG. 4 (d) is a plan view thereof. 1 to 3, the same reference numerals indicate the same or equivalent parts.

Now, as shown in FIG. 4, inside the cylinder 2, the armature 24, the piston 26 and the piston shaft 28 are provided.
A piston assembly in which the above three are integrated is housed. The armature 24 and the piston 26 have a central hole, the piston shaft 28 is composed of a small diameter portion and a large diameter portion, and by pressing the small diameter portion into both the central hole of the armature 24 and the piston 26, the armature, piston and Piston shaft 3
The person is separated and cannot escape. The large diameter portion of the piston shaft 28 is slidably inserted into the piston shaft guide hole 6 with an extremely small fitting tolerance. Therefore, the piston shaft guide hole 6 of the rear cylinder 3a of the cylinder 2 is
The inner wall surface of the front cylinder 3b serves as a bearing before and after the sliding surface of the piston. Further, a spring 22 disposed around the large diameter portion is provided with a piston assembly including an armature 24 and a piston 26 toward the left end of the front cylinder 3b in FIG. 4 (a), that is, the top dead center. I am energetic.

The intake valve 30 fixed in a state of being sandwiched by the left front opening side end of the front cylinder 3b and the cylinder head forming lid 31 closing the same is such that the piston 26 has the piston 26 rightward in FIG. 4 (a). That is, when it is moved in the direction of the bottom dead center, the fluid such as air and liquid sent through the suction pipe 32 is opened in the working chamber formed by the front cylinder 3b, the piston 26, the lid 31 and the like. Introduce. On the contrary, when the piston 26 is moved to the left in FIG. 4, that is, toward the top dead center, the suction valve 30 is closed to prevent the fluid in the working chamber from flowing back to the suction pipe 32.

Further, the piston 26 has a tip portion formed in a shape as shown in FIG. That is, as is apparent from the perspective view of FIG. 5, the tip of the piston is located at the boundary between the small-diameter cylindrical portion 50 and the small-diameter cylindrical portion 50, which is slightly smaller than the cross-sectional diameter of the piston main cylindrical portion. Formed annular step
52, the small diameter cylindrical portion 50 is slightly separated from the cylinder inner diameter surface to form a space on the outer circumference of the small diameter cylindrical portion. When the piston having such a structure is used, when the piston moves from the bottom dead center to the top dead center, the tip surface of the small diameter cylindrical portion 50 leaves a minimum space between the cylinder head 31 and the tip surface. It serves to bring the position of the top dead center closer to the cylinder head 31 by approaching to the limit, in other words, the stroke of the piston can be lengthened to improve pump efficiency.

As shown in FIG. 4A, a field core 38 forming a part of a fixed electromagnetic circuit is fixed to the flange 8 projecting from the outer periphery of the cylinder 2 with a screw 36. An induction coil 40 is attached to each of a pair of magnetic poles of the field core 38 provided so as to face each other with the reciprocating passage of the armature 24 interposed therebetween to form a fixed electromagnetic circuit.

In the figure, 48 is a rectifier, and 49 is a mounting frame supported by four vibration-proof rubbers 54. The mounting frame 49
Is for mechanically fixing the field core 38.

Now, in the compressor of the present embodiment, when a half-wave AC having an appropriate frequency is passed through the induction coil 40, the field core 38 is excited at time intervals corresponding to the frequency. When the field core 38 is excited, the armature
Since 24 is attracted to the excitation 42 of the field core 38, the piston 26 moves to the right in FIG. 4 (a) against the spring 22 and is brought to the position of bottom dead center. On the other hand, when the excitation of the magnetic pole 42 is turned off, the amateur 24 is released from the excitation 42.
At this time, the piston 26 is carried toward the top dead center by the restoring force of the spring 22.

When the piston comes near the top dead center, even if the tip of the piston passes the position facing the discharge port 18, it is formed by the small diameter cylindrical portion 50 and the annular stepped portion 52 provided at the tip of the piston. Since the space inside the piston is much smaller than the space formed between the tip of the piston and the cylinder head, the piston does not have an unnecessarily large air cushion effect. The discharge pressure can be stabilized by proceeding in the direction of the head.

Although polyamideimide is used as the material of the cylinder 2 in this embodiment, it is needless to say that other material may be used as long as it is a non-magnetic insulator having a thermal expansion coefficient close to that of the piston 26 and the armature 24. Is.

(Effect of the Invention) According to the present invention, since the discharge port is provided with a beak-shaped valve, the sealing property is improved, and thus the discharge pressure is stabilized,
It has the effect of eliminating the piston shock. Further, since the position of the top dead center of the piston can be made as close as possible to the cylinder head, the pump efficiency can be improved.

[Brief description of drawings]

1 is a perspective view of a cylinder according to an embodiment of the present invention, FIG. 2 (a) is a vertical side view of the cylinder, FIG. 2 (b) is a front view, and FIG. 3 (a) is a front cylinder. FIG. 3 (b) is a horizontal cross-sectional view of the discharge port portion, and FIG.
FIG. 4 is a vertical sectional side view of the electromagnetic reciprocating compressor of the present invention in which the piston, the fixed electromagnetic circuit, etc. are mounted on the cylinder shown in FIG.
FIG. 4 (b) is its front view, FIG. 4 (c) is its rear view, FIG. 4 (d) is its plan view, FIG. 5 is a perspective view of the piston tip, and FIG. 6 is the front of the field core. The figure is shown. 2 ... Cylinder, 3a ... Rear cylinder, 3b ... Front cylinder,
18 ... Discharge port, 22 ... Spring, 24 ... Armature, 26 ...
Piston, 33 ... Duck beak valve, 50 ... Small diameter cylindrical part, 52 ... Annular step

Claims (1)

[Scope of utility model registration request] 1. A piston is provided in a cylinder that moves forward by the electromagnetic action of a fixed electromagnetic circuit and returns by the elastic force of a compression spring, and the piston is arranged in the axial direction of the cylinder without any connecting means. In an electromagnetic reciprocating compressor of a reciprocating drive type, the piston has a configuration in which a small diameter portion that does not make surface contact with a cylinder circumferential wall surface is formed at an end portion on the cylinder head side, and when the piston passes near the top dead center, An electromagnetic reciprocating compressor characterized in that a discharge port is provided on at least a part of a circumferential wall surface of a cylinder where a small diameter portion does not come into surface contact, and is closed by a duck's beak-shaped elastic on-off valve projecting outward of the discharge port.